forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
7326 lines
188 KiB
7326 lines
188 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* Copyright (c) 2018 Facebook */ |
|
|
|
#include <uapi/linux/btf.h> |
|
#include <uapi/linux/bpf.h> |
|
#include <uapi/linux/bpf_perf_event.h> |
|
#include <uapi/linux/types.h> |
|
#include <linux/seq_file.h> |
|
#include <linux/compiler.h> |
|
#include <linux/ctype.h> |
|
#include <linux/errno.h> |
|
#include <linux/slab.h> |
|
#include <linux/anon_inodes.h> |
|
#include <linux/file.h> |
|
#include <linux/uaccess.h> |
|
#include <linux/kernel.h> |
|
#include <linux/idr.h> |
|
#include <linux/sort.h> |
|
#include <linux/bpf_verifier.h> |
|
#include <linux/btf.h> |
|
#include <linux/btf_ids.h> |
|
#include <linux/skmsg.h> |
|
#include <linux/perf_event.h> |
|
#include <linux/bsearch.h> |
|
#include <linux/kobject.h> |
|
#include <linux/sysfs.h> |
|
#include <net/sock.h> |
|
#include "../tools/lib/bpf/relo_core.h" |
|
|
|
/* BTF (BPF Type Format) is the meta data format which describes |
|
* the data types of BPF program/map. Hence, it basically focus |
|
* on the C programming language which the modern BPF is primary |
|
* using. |
|
* |
|
* ELF Section: |
|
* ~~~~~~~~~~~ |
|
* The BTF data is stored under the ".BTF" ELF section |
|
* |
|
* struct btf_type: |
|
* ~~~~~~~~~~~~~~~ |
|
* Each 'struct btf_type' object describes a C data type. |
|
* Depending on the type it is describing, a 'struct btf_type' |
|
* object may be followed by more data. F.e. |
|
* To describe an array, 'struct btf_type' is followed by |
|
* 'struct btf_array'. |
|
* |
|
* 'struct btf_type' and any extra data following it are |
|
* 4 bytes aligned. |
|
* |
|
* Type section: |
|
* ~~~~~~~~~~~~~ |
|
* The BTF type section contains a list of 'struct btf_type' objects. |
|
* Each one describes a C type. Recall from the above section |
|
* that a 'struct btf_type' object could be immediately followed by extra |
|
* data in order to describe some particular C types. |
|
* |
|
* type_id: |
|
* ~~~~~~~ |
|
* Each btf_type object is identified by a type_id. The type_id |
|
* is implicitly implied by the location of the btf_type object in |
|
* the BTF type section. The first one has type_id 1. The second |
|
* one has type_id 2...etc. Hence, an earlier btf_type has |
|
* a smaller type_id. |
|
* |
|
* A btf_type object may refer to another btf_type object by using |
|
* type_id (i.e. the "type" in the "struct btf_type"). |
|
* |
|
* NOTE that we cannot assume any reference-order. |
|
* A btf_type object can refer to an earlier btf_type object |
|
* but it can also refer to a later btf_type object. |
|
* |
|
* For example, to describe "const void *". A btf_type |
|
* object describing "const" may refer to another btf_type |
|
* object describing "void *". This type-reference is done |
|
* by specifying type_id: |
|
* |
|
* [1] CONST (anon) type_id=2 |
|
* [2] PTR (anon) type_id=0 |
|
* |
|
* The above is the btf_verifier debug log: |
|
* - Each line started with "[?]" is a btf_type object |
|
* - [?] is the type_id of the btf_type object. |
|
* - CONST/PTR is the BTF_KIND_XXX |
|
* - "(anon)" is the name of the type. It just |
|
* happens that CONST and PTR has no name. |
|
* - type_id=XXX is the 'u32 type' in btf_type |
|
* |
|
* NOTE: "void" has type_id 0 |
|
* |
|
* String section: |
|
* ~~~~~~~~~~~~~~ |
|
* The BTF string section contains the names used by the type section. |
|
* Each string is referred by an "offset" from the beginning of the |
|
* string section. |
|
* |
|
* Each string is '\0' terminated. |
|
* |
|
* The first character in the string section must be '\0' |
|
* which is used to mean 'anonymous'. Some btf_type may not |
|
* have a name. |
|
*/ |
|
|
|
/* BTF verification: |
|
* |
|
* To verify BTF data, two passes are needed. |
|
* |
|
* Pass #1 |
|
* ~~~~~~~ |
|
* The first pass is to collect all btf_type objects to |
|
* an array: "btf->types". |
|
* |
|
* Depending on the C type that a btf_type is describing, |
|
* a btf_type may be followed by extra data. We don't know |
|
* how many btf_type is there, and more importantly we don't |
|
* know where each btf_type is located in the type section. |
|
* |
|
* Without knowing the location of each type_id, most verifications |
|
* cannot be done. e.g. an earlier btf_type may refer to a later |
|
* btf_type (recall the "const void *" above), so we cannot |
|
* check this type-reference in the first pass. |
|
* |
|
* In the first pass, it still does some verifications (e.g. |
|
* checking the name is a valid offset to the string section). |
|
* |
|
* Pass #2 |
|
* ~~~~~~~ |
|
* The main focus is to resolve a btf_type that is referring |
|
* to another type. |
|
* |
|
* We have to ensure the referring type: |
|
* 1) does exist in the BTF (i.e. in btf->types[]) |
|
* 2) does not cause a loop: |
|
* struct A { |
|
* struct B b; |
|
* }; |
|
* |
|
* struct B { |
|
* struct A a; |
|
* }; |
|
* |
|
* btf_type_needs_resolve() decides if a btf_type needs |
|
* to be resolved. |
|
* |
|
* The needs_resolve type implements the "resolve()" ops which |
|
* essentially does a DFS and detects backedge. |
|
* |
|
* During resolve (or DFS), different C types have different |
|
* "RESOLVED" conditions. |
|
* |
|
* When resolving a BTF_KIND_STRUCT, we need to resolve all its |
|
* members because a member is always referring to another |
|
* type. A struct's member can be treated as "RESOLVED" if |
|
* it is referring to a BTF_KIND_PTR. Otherwise, the |
|
* following valid C struct would be rejected: |
|
* |
|
* struct A { |
|
* int m; |
|
* struct A *a; |
|
* }; |
|
* |
|
* When resolving a BTF_KIND_PTR, it needs to keep resolving if |
|
* it is referring to another BTF_KIND_PTR. Otherwise, we cannot |
|
* detect a pointer loop, e.g.: |
|
* BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR + |
|
* ^ | |
|
* +-----------------------------------------+ |
|
* |
|
*/ |
|
|
|
#define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2) |
|
#define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1) |
|
#define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK) |
|
#define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3) |
|
#define BITS_ROUNDUP_BYTES(bits) \ |
|
(BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits)) |
|
|
|
#define BTF_INFO_MASK 0x9f00ffff |
|
#define BTF_INT_MASK 0x0fffffff |
|
#define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE) |
|
#define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET) |
|
|
|
/* 16MB for 64k structs and each has 16 members and |
|
* a few MB spaces for the string section. |
|
* The hard limit is S32_MAX. |
|
*/ |
|
#define BTF_MAX_SIZE (16 * 1024 * 1024) |
|
|
|
#define for_each_member_from(i, from, struct_type, member) \ |
|
for (i = from, member = btf_type_member(struct_type) + from; \ |
|
i < btf_type_vlen(struct_type); \ |
|
i++, member++) |
|
|
|
#define for_each_vsi_from(i, from, struct_type, member) \ |
|
for (i = from, member = btf_type_var_secinfo(struct_type) + from; \ |
|
i < btf_type_vlen(struct_type); \ |
|
i++, member++) |
|
|
|
DEFINE_IDR(btf_idr); |
|
DEFINE_SPINLOCK(btf_idr_lock); |
|
|
|
enum btf_kfunc_hook { |
|
BTF_KFUNC_HOOK_XDP, |
|
BTF_KFUNC_HOOK_TC, |
|
BTF_KFUNC_HOOK_STRUCT_OPS, |
|
BTF_KFUNC_HOOK_MAX, |
|
}; |
|
|
|
enum { |
|
BTF_KFUNC_SET_MAX_CNT = 32, |
|
}; |
|
|
|
struct btf_kfunc_set_tab { |
|
struct btf_id_set *sets[BTF_KFUNC_HOOK_MAX][BTF_KFUNC_TYPE_MAX]; |
|
}; |
|
|
|
struct btf { |
|
void *data; |
|
struct btf_type **types; |
|
u32 *resolved_ids; |
|
u32 *resolved_sizes; |
|
const char *strings; |
|
void *nohdr_data; |
|
struct btf_header hdr; |
|
u32 nr_types; /* includes VOID for base BTF */ |
|
u32 types_size; |
|
u32 data_size; |
|
refcount_t refcnt; |
|
u32 id; |
|
struct rcu_head rcu; |
|
struct btf_kfunc_set_tab *kfunc_set_tab; |
|
|
|
/* split BTF support */ |
|
struct btf *base_btf; |
|
u32 start_id; /* first type ID in this BTF (0 for base BTF) */ |
|
u32 start_str_off; /* first string offset (0 for base BTF) */ |
|
char name[MODULE_NAME_LEN]; |
|
bool kernel_btf; |
|
}; |
|
|
|
enum verifier_phase { |
|
CHECK_META, |
|
CHECK_TYPE, |
|
}; |
|
|
|
struct resolve_vertex { |
|
const struct btf_type *t; |
|
u32 type_id; |
|
u16 next_member; |
|
}; |
|
|
|
enum visit_state { |
|
NOT_VISITED, |
|
VISITED, |
|
RESOLVED, |
|
}; |
|
|
|
enum resolve_mode { |
|
RESOLVE_TBD, /* To Be Determined */ |
|
RESOLVE_PTR, /* Resolving for Pointer */ |
|
RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union |
|
* or array |
|
*/ |
|
}; |
|
|
|
#define MAX_RESOLVE_DEPTH 32 |
|
|
|
struct btf_sec_info { |
|
u32 off; |
|
u32 len; |
|
}; |
|
|
|
struct btf_verifier_env { |
|
struct btf *btf; |
|
u8 *visit_states; |
|
struct resolve_vertex stack[MAX_RESOLVE_DEPTH]; |
|
struct bpf_verifier_log log; |
|
u32 log_type_id; |
|
u32 top_stack; |
|
enum verifier_phase phase; |
|
enum resolve_mode resolve_mode; |
|
}; |
|
|
|
static const char * const btf_kind_str[NR_BTF_KINDS] = { |
|
[BTF_KIND_UNKN] = "UNKNOWN", |
|
[BTF_KIND_INT] = "INT", |
|
[BTF_KIND_PTR] = "PTR", |
|
[BTF_KIND_ARRAY] = "ARRAY", |
|
[BTF_KIND_STRUCT] = "STRUCT", |
|
[BTF_KIND_UNION] = "UNION", |
|
[BTF_KIND_ENUM] = "ENUM", |
|
[BTF_KIND_FWD] = "FWD", |
|
[BTF_KIND_TYPEDEF] = "TYPEDEF", |
|
[BTF_KIND_VOLATILE] = "VOLATILE", |
|
[BTF_KIND_CONST] = "CONST", |
|
[BTF_KIND_RESTRICT] = "RESTRICT", |
|
[BTF_KIND_FUNC] = "FUNC", |
|
[BTF_KIND_FUNC_PROTO] = "FUNC_PROTO", |
|
[BTF_KIND_VAR] = "VAR", |
|
[BTF_KIND_DATASEC] = "DATASEC", |
|
[BTF_KIND_FLOAT] = "FLOAT", |
|
[BTF_KIND_DECL_TAG] = "DECL_TAG", |
|
[BTF_KIND_TYPE_TAG] = "TYPE_TAG", |
|
}; |
|
|
|
const char *btf_type_str(const struct btf_type *t) |
|
{ |
|
return btf_kind_str[BTF_INFO_KIND(t->info)]; |
|
} |
|
|
|
/* Chunk size we use in safe copy of data to be shown. */ |
|
#define BTF_SHOW_OBJ_SAFE_SIZE 32 |
|
|
|
/* |
|
* This is the maximum size of a base type value (equivalent to a |
|
* 128-bit int); if we are at the end of our safe buffer and have |
|
* less than 16 bytes space we can't be assured of being able |
|
* to copy the next type safely, so in such cases we will initiate |
|
* a new copy. |
|
*/ |
|
#define BTF_SHOW_OBJ_BASE_TYPE_SIZE 16 |
|
|
|
/* Type name size */ |
|
#define BTF_SHOW_NAME_SIZE 80 |
|
|
|
/* |
|
* Common data to all BTF show operations. Private show functions can add |
|
* their own data to a structure containing a struct btf_show and consult it |
|
* in the show callback. See btf_type_show() below. |
|
* |
|
* One challenge with showing nested data is we want to skip 0-valued |
|
* data, but in order to figure out whether a nested object is all zeros |
|
* we need to walk through it. As a result, we need to make two passes |
|
* when handling structs, unions and arrays; the first path simply looks |
|
* for nonzero data, while the second actually does the display. The first |
|
* pass is signalled by show->state.depth_check being set, and if we |
|
* encounter a non-zero value we set show->state.depth_to_show to |
|
* the depth at which we encountered it. When we have completed the |
|
* first pass, we will know if anything needs to be displayed if |
|
* depth_to_show > depth. See btf_[struct,array]_show() for the |
|
* implementation of this. |
|
* |
|
* Another problem is we want to ensure the data for display is safe to |
|
* access. To support this, the anonymous "struct {} obj" tracks the data |
|
* object and our safe copy of it. We copy portions of the data needed |
|
* to the object "copy" buffer, but because its size is limited to |
|
* BTF_SHOW_OBJ_COPY_LEN bytes, multiple copies may be required as we |
|
* traverse larger objects for display. |
|
* |
|
* The various data type show functions all start with a call to |
|
* btf_show_start_type() which returns a pointer to the safe copy |
|
* of the data needed (or if BTF_SHOW_UNSAFE is specified, to the |
|
* raw data itself). btf_show_obj_safe() is responsible for |
|
* using copy_from_kernel_nofault() to update the safe data if necessary |
|
* as we traverse the object's data. skbuff-like semantics are |
|
* used: |
|
* |
|
* - obj.head points to the start of the toplevel object for display |
|
* - obj.size is the size of the toplevel object |
|
* - obj.data points to the current point in the original data at |
|
* which our safe data starts. obj.data will advance as we copy |
|
* portions of the data. |
|
* |
|
* In most cases a single copy will suffice, but larger data structures |
|
* such as "struct task_struct" will require many copies. The logic in |
|
* btf_show_obj_safe() handles the logic that determines if a new |
|
* copy_from_kernel_nofault() is needed. |
|
*/ |
|
struct btf_show { |
|
u64 flags; |
|
void *target; /* target of show operation (seq file, buffer) */ |
|
void (*showfn)(struct btf_show *show, const char *fmt, va_list args); |
|
const struct btf *btf; |
|
/* below are used during iteration */ |
|
struct { |
|
u8 depth; |
|
u8 depth_to_show; |
|
u8 depth_check; |
|
u8 array_member:1, |
|
array_terminated:1; |
|
u16 array_encoding; |
|
u32 type_id; |
|
int status; /* non-zero for error */ |
|
const struct btf_type *type; |
|
const struct btf_member *member; |
|
char name[BTF_SHOW_NAME_SIZE]; /* space for member name/type */ |
|
} state; |
|
struct { |
|
u32 size; |
|
void *head; |
|
void *data; |
|
u8 safe[BTF_SHOW_OBJ_SAFE_SIZE]; |
|
} obj; |
|
}; |
|
|
|
struct btf_kind_operations { |
|
s32 (*check_meta)(struct btf_verifier_env *env, |
|
const struct btf_type *t, |
|
u32 meta_left); |
|
int (*resolve)(struct btf_verifier_env *env, |
|
const struct resolve_vertex *v); |
|
int (*check_member)(struct btf_verifier_env *env, |
|
const struct btf_type *struct_type, |
|
const struct btf_member *member, |
|
const struct btf_type *member_type); |
|
int (*check_kflag_member)(struct btf_verifier_env *env, |
|
const struct btf_type *struct_type, |
|
const struct btf_member *member, |
|
const struct btf_type *member_type); |
|
void (*log_details)(struct btf_verifier_env *env, |
|
const struct btf_type *t); |
|
void (*show)(const struct btf *btf, const struct btf_type *t, |
|
u32 type_id, void *data, u8 bits_offsets, |
|
struct btf_show *show); |
|
}; |
|
|
|
static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS]; |
|
static struct btf_type btf_void; |
|
|
|
static int btf_resolve(struct btf_verifier_env *env, |
|
const struct btf_type *t, u32 type_id); |
|
|
|
static int btf_func_check(struct btf_verifier_env *env, |
|
const struct btf_type *t); |
|
|
|
static bool btf_type_is_modifier(const struct btf_type *t) |
|
{ |
|
/* Some of them is not strictly a C modifier |
|
* but they are grouped into the same bucket |
|
* for BTF concern: |
|
* A type (t) that refers to another |
|
* type through t->type AND its size cannot |
|
* be determined without following the t->type. |
|
* |
|
* ptr does not fall into this bucket |
|
* because its size is always sizeof(void *). |
|
*/ |
|
switch (BTF_INFO_KIND(t->info)) { |
|
case BTF_KIND_TYPEDEF: |
|
case BTF_KIND_VOLATILE: |
|
case BTF_KIND_CONST: |
|
case BTF_KIND_RESTRICT: |
|
case BTF_KIND_TYPE_TAG: |
|
return true; |
|
} |
|
|
|
return false; |
|
} |
|
|
|
bool btf_type_is_void(const struct btf_type *t) |
|
{ |
|
return t == &btf_void; |
|
} |
|
|
|
static bool btf_type_is_fwd(const struct btf_type *t) |
|
{ |
|
return BTF_INFO_KIND(t->info) == BTF_KIND_FWD; |
|
} |
|
|
|
static bool btf_type_nosize(const struct btf_type *t) |
|
{ |
|
return btf_type_is_void(t) || btf_type_is_fwd(t) || |
|
btf_type_is_func(t) || btf_type_is_func_proto(t); |
|
} |
|
|
|
static bool btf_type_nosize_or_null(const struct btf_type *t) |
|
{ |
|
return !t || btf_type_nosize(t); |
|
} |
|
|
|
static bool __btf_type_is_struct(const struct btf_type *t) |
|
{ |
|
return BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT; |
|
} |
|
|
|
static bool btf_type_is_array(const struct btf_type *t) |
|
{ |
|
return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY; |
|
} |
|
|
|
static bool btf_type_is_datasec(const struct btf_type *t) |
|
{ |
|
return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC; |
|
} |
|
|
|
static bool btf_type_is_decl_tag(const struct btf_type *t) |
|
{ |
|
return BTF_INFO_KIND(t->info) == BTF_KIND_DECL_TAG; |
|
} |
|
|
|
static bool btf_type_is_decl_tag_target(const struct btf_type *t) |
|
{ |
|
return btf_type_is_func(t) || btf_type_is_struct(t) || |
|
btf_type_is_var(t) || btf_type_is_typedef(t); |
|
} |
|
|
|
u32 btf_nr_types(const struct btf *btf) |
|
{ |
|
u32 total = 0; |
|
|
|
while (btf) { |
|
total += btf->nr_types; |
|
btf = btf->base_btf; |
|
} |
|
|
|
return total; |
|
} |
|
|
|
s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind) |
|
{ |
|
const struct btf_type *t; |
|
const char *tname; |
|
u32 i, total; |
|
|
|
total = btf_nr_types(btf); |
|
for (i = 1; i < total; i++) { |
|
t = btf_type_by_id(btf, i); |
|
if (BTF_INFO_KIND(t->info) != kind) |
|
continue; |
|
|
|
tname = btf_name_by_offset(btf, t->name_off); |
|
if (!strcmp(tname, name)) |
|
return i; |
|
} |
|
|
|
return -ENOENT; |
|
} |
|
|
|
static s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p) |
|
{ |
|
struct btf *btf; |
|
s32 ret; |
|
int id; |
|
|
|
btf = bpf_get_btf_vmlinux(); |
|
if (IS_ERR(btf)) |
|
return PTR_ERR(btf); |
|
if (!btf) |
|
return -EINVAL; |
|
|
|
ret = btf_find_by_name_kind(btf, name, kind); |
|
/* ret is never zero, since btf_find_by_name_kind returns |
|
* positive btf_id or negative error. |
|
*/ |
|
if (ret > 0) { |
|
btf_get(btf); |
|
*btf_p = btf; |
|
return ret; |
|
} |
|
|
|
/* If name is not found in vmlinux's BTF then search in module's BTFs */ |
|
spin_lock_bh(&btf_idr_lock); |
|
idr_for_each_entry(&btf_idr, btf, id) { |
|
if (!btf_is_module(btf)) |
|
continue; |
|
/* linear search could be slow hence unlock/lock |
|
* the IDR to avoiding holding it for too long |
|
*/ |
|
btf_get(btf); |
|
spin_unlock_bh(&btf_idr_lock); |
|
ret = btf_find_by_name_kind(btf, name, kind); |
|
if (ret > 0) { |
|
*btf_p = btf; |
|
return ret; |
|
} |
|
spin_lock_bh(&btf_idr_lock); |
|
btf_put(btf); |
|
} |
|
spin_unlock_bh(&btf_idr_lock); |
|
return ret; |
|
} |
|
|
|
const struct btf_type *btf_type_skip_modifiers(const struct btf *btf, |
|
u32 id, u32 *res_id) |
|
{ |
|
const struct btf_type *t = btf_type_by_id(btf, id); |
|
|
|
while (btf_type_is_modifier(t)) { |
|
id = t->type; |
|
t = btf_type_by_id(btf, t->type); |
|
} |
|
|
|
if (res_id) |
|
*res_id = id; |
|
|
|
return t; |
|
} |
|
|
|
const struct btf_type *btf_type_resolve_ptr(const struct btf *btf, |
|
u32 id, u32 *res_id) |
|
{ |
|
const struct btf_type *t; |
|
|
|
t = btf_type_skip_modifiers(btf, id, NULL); |
|
if (!btf_type_is_ptr(t)) |
|
return NULL; |
|
|
|
return btf_type_skip_modifiers(btf, t->type, res_id); |
|
} |
|
|
|
const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf, |
|
u32 id, u32 *res_id) |
|
{ |
|
const struct btf_type *ptype; |
|
|
|
ptype = btf_type_resolve_ptr(btf, id, res_id); |
|
if (ptype && btf_type_is_func_proto(ptype)) |
|
return ptype; |
|
|
|
return NULL; |
|
} |
|
|
|
/* Types that act only as a source, not sink or intermediate |
|
* type when resolving. |
|
*/ |
|
static bool btf_type_is_resolve_source_only(const struct btf_type *t) |
|
{ |
|
return btf_type_is_var(t) || |
|
btf_type_is_decl_tag(t) || |
|
btf_type_is_datasec(t); |
|
} |
|
|
|
/* What types need to be resolved? |
|
* |
|
* btf_type_is_modifier() is an obvious one. |
|
* |
|
* btf_type_is_struct() because its member refers to |
|
* another type (through member->type). |
|
* |
|
* btf_type_is_var() because the variable refers to |
|
* another type. btf_type_is_datasec() holds multiple |
|
* btf_type_is_var() types that need resolving. |
|
* |
|
* btf_type_is_array() because its element (array->type) |
|
* refers to another type. Array can be thought of a |
|
* special case of struct while array just has the same |
|
* member-type repeated by array->nelems of times. |
|
*/ |
|
static bool btf_type_needs_resolve(const struct btf_type *t) |
|
{ |
|
return btf_type_is_modifier(t) || |
|
btf_type_is_ptr(t) || |
|
btf_type_is_struct(t) || |
|
btf_type_is_array(t) || |
|
btf_type_is_var(t) || |
|
btf_type_is_func(t) || |
|
btf_type_is_decl_tag(t) || |
|
btf_type_is_datasec(t); |
|
} |
|
|
|
/* t->size can be used */ |
|
static bool btf_type_has_size(const struct btf_type *t) |
|
{ |
|
switch (BTF_INFO_KIND(t->info)) { |
|
case BTF_KIND_INT: |
|
case BTF_KIND_STRUCT: |
|
case BTF_KIND_UNION: |
|
case BTF_KIND_ENUM: |
|
case BTF_KIND_DATASEC: |
|
case BTF_KIND_FLOAT: |
|
return true; |
|
} |
|
|
|
return false; |
|
} |
|
|
|
static const char *btf_int_encoding_str(u8 encoding) |
|
{ |
|
if (encoding == 0) |
|
return "(none)"; |
|
else if (encoding == BTF_INT_SIGNED) |
|
return "SIGNED"; |
|
else if (encoding == BTF_INT_CHAR) |
|
return "CHAR"; |
|
else if (encoding == BTF_INT_BOOL) |
|
return "BOOL"; |
|
else |
|
return "UNKN"; |
|
} |
|
|
|
static u32 btf_type_int(const struct btf_type *t) |
|
{ |
|
return *(u32 *)(t + 1); |
|
} |
|
|
|
static const struct btf_array *btf_type_array(const struct btf_type *t) |
|
{ |
|
return (const struct btf_array *)(t + 1); |
|
} |
|
|
|
static const struct btf_enum *btf_type_enum(const struct btf_type *t) |
|
{ |
|
return (const struct btf_enum *)(t + 1); |
|
} |
|
|
|
static const struct btf_var *btf_type_var(const struct btf_type *t) |
|
{ |
|
return (const struct btf_var *)(t + 1); |
|
} |
|
|
|
static const struct btf_decl_tag *btf_type_decl_tag(const struct btf_type *t) |
|
{ |
|
return (const struct btf_decl_tag *)(t + 1); |
|
} |
|
|
|
static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t) |
|
{ |
|
return kind_ops[BTF_INFO_KIND(t->info)]; |
|
} |
|
|
|
static bool btf_name_offset_valid(const struct btf *btf, u32 offset) |
|
{ |
|
if (!BTF_STR_OFFSET_VALID(offset)) |
|
return false; |
|
|
|
while (offset < btf->start_str_off) |
|
btf = btf->base_btf; |
|
|
|
offset -= btf->start_str_off; |
|
return offset < btf->hdr.str_len; |
|
} |
|
|
|
static bool __btf_name_char_ok(char c, bool first, bool dot_ok) |
|
{ |
|
if ((first ? !isalpha(c) : |
|
!isalnum(c)) && |
|
c != '_' && |
|
((c == '.' && !dot_ok) || |
|
c != '.')) |
|
return false; |
|
return true; |
|
} |
|
|
|
static const char *btf_str_by_offset(const struct btf *btf, u32 offset) |
|
{ |
|
while (offset < btf->start_str_off) |
|
btf = btf->base_btf; |
|
|
|
offset -= btf->start_str_off; |
|
if (offset < btf->hdr.str_len) |
|
return &btf->strings[offset]; |
|
|
|
return NULL; |
|
} |
|
|
|
static bool __btf_name_valid(const struct btf *btf, u32 offset, bool dot_ok) |
|
{ |
|
/* offset must be valid */ |
|
const char *src = btf_str_by_offset(btf, offset); |
|
const char *src_limit; |
|
|
|
if (!__btf_name_char_ok(*src, true, dot_ok)) |
|
return false; |
|
|
|
/* set a limit on identifier length */ |
|
src_limit = src + KSYM_NAME_LEN; |
|
src++; |
|
while (*src && src < src_limit) { |
|
if (!__btf_name_char_ok(*src, false, dot_ok)) |
|
return false; |
|
src++; |
|
} |
|
|
|
return !*src; |
|
} |
|
|
|
/* Only C-style identifier is permitted. This can be relaxed if |
|
* necessary. |
|
*/ |
|
static bool btf_name_valid_identifier(const struct btf *btf, u32 offset) |
|
{ |
|
return __btf_name_valid(btf, offset, false); |
|
} |
|
|
|
static bool btf_name_valid_section(const struct btf *btf, u32 offset) |
|
{ |
|
return __btf_name_valid(btf, offset, true); |
|
} |
|
|
|
static const char *__btf_name_by_offset(const struct btf *btf, u32 offset) |
|
{ |
|
const char *name; |
|
|
|
if (!offset) |
|
return "(anon)"; |
|
|
|
name = btf_str_by_offset(btf, offset); |
|
return name ?: "(invalid-name-offset)"; |
|
} |
|
|
|
const char *btf_name_by_offset(const struct btf *btf, u32 offset) |
|
{ |
|
return btf_str_by_offset(btf, offset); |
|
} |
|
|
|
const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id) |
|
{ |
|
while (type_id < btf->start_id) |
|
btf = btf->base_btf; |
|
|
|
type_id -= btf->start_id; |
|
if (type_id >= btf->nr_types) |
|
return NULL; |
|
return btf->types[type_id]; |
|
} |
|
|
|
/* |
|
* Regular int is not a bit field and it must be either |
|
* u8/u16/u32/u64 or __int128. |
|
*/ |
|
static bool btf_type_int_is_regular(const struct btf_type *t) |
|
{ |
|
u8 nr_bits, nr_bytes; |
|
u32 int_data; |
|
|
|
int_data = btf_type_int(t); |
|
nr_bits = BTF_INT_BITS(int_data); |
|
nr_bytes = BITS_ROUNDUP_BYTES(nr_bits); |
|
if (BITS_PER_BYTE_MASKED(nr_bits) || |
|
BTF_INT_OFFSET(int_data) || |
|
(nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) && |
|
nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) && |
|
nr_bytes != (2 * sizeof(u64)))) { |
|
return false; |
|
} |
|
|
|
return true; |
|
} |
|
|
|
/* |
|
* Check that given struct member is a regular int with expected |
|
* offset and size. |
|
*/ |
|
bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s, |
|
const struct btf_member *m, |
|
u32 expected_offset, u32 expected_size) |
|
{ |
|
const struct btf_type *t; |
|
u32 id, int_data; |
|
u8 nr_bits; |
|
|
|
id = m->type; |
|
t = btf_type_id_size(btf, &id, NULL); |
|
if (!t || !btf_type_is_int(t)) |
|
return false; |
|
|
|
int_data = btf_type_int(t); |
|
nr_bits = BTF_INT_BITS(int_data); |
|
if (btf_type_kflag(s)) { |
|
u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset); |
|
u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset); |
|
|
|
/* if kflag set, int should be a regular int and |
|
* bit offset should be at byte boundary. |
|
*/ |
|
return !bitfield_size && |
|
BITS_ROUNDUP_BYTES(bit_offset) == expected_offset && |
|
BITS_ROUNDUP_BYTES(nr_bits) == expected_size; |
|
} |
|
|
|
if (BTF_INT_OFFSET(int_data) || |
|
BITS_PER_BYTE_MASKED(m->offset) || |
|
BITS_ROUNDUP_BYTES(m->offset) != expected_offset || |
|
BITS_PER_BYTE_MASKED(nr_bits) || |
|
BITS_ROUNDUP_BYTES(nr_bits) != expected_size) |
|
return false; |
|
|
|
return true; |
|
} |
|
|
|
/* Similar to btf_type_skip_modifiers() but does not skip typedefs. */ |
|
static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf, |
|
u32 id) |
|
{ |
|
const struct btf_type *t = btf_type_by_id(btf, id); |
|
|
|
while (btf_type_is_modifier(t) && |
|
BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) { |
|
t = btf_type_by_id(btf, t->type); |
|
} |
|
|
|
return t; |
|
} |
|
|
|
#define BTF_SHOW_MAX_ITER 10 |
|
|
|
#define BTF_KIND_BIT(kind) (1ULL << kind) |
|
|
|
/* |
|
* Populate show->state.name with type name information. |
|
* Format of type name is |
|
* |
|
* [.member_name = ] (type_name) |
|
*/ |
|
static const char *btf_show_name(struct btf_show *show) |
|
{ |
|
/* BTF_MAX_ITER array suffixes "[]" */ |
|
const char *array_suffixes = "[][][][][][][][][][]"; |
|
const char *array_suffix = &array_suffixes[strlen(array_suffixes)]; |
|
/* BTF_MAX_ITER pointer suffixes "*" */ |
|
const char *ptr_suffixes = "**********"; |
|
const char *ptr_suffix = &ptr_suffixes[strlen(ptr_suffixes)]; |
|
const char *name = NULL, *prefix = "", *parens = ""; |
|
const struct btf_member *m = show->state.member; |
|
const struct btf_type *t; |
|
const struct btf_array *array; |
|
u32 id = show->state.type_id; |
|
const char *member = NULL; |
|
bool show_member = false; |
|
u64 kinds = 0; |
|
int i; |
|
|
|
show->state.name[0] = '\0'; |
|
|
|
/* |
|
* Don't show type name if we're showing an array member; |
|
* in that case we show the array type so don't need to repeat |
|
* ourselves for each member. |
|
*/ |
|
if (show->state.array_member) |
|
return ""; |
|
|
|
/* Retrieve member name, if any. */ |
|
if (m) { |
|
member = btf_name_by_offset(show->btf, m->name_off); |
|
show_member = strlen(member) > 0; |
|
id = m->type; |
|
} |
|
|
|
/* |
|
* Start with type_id, as we have resolved the struct btf_type * |
|
* via btf_modifier_show() past the parent typedef to the child |
|
* struct, int etc it is defined as. In such cases, the type_id |
|
* still represents the starting type while the struct btf_type * |
|
* in our show->state points at the resolved type of the typedef. |
|
*/ |
|
t = btf_type_by_id(show->btf, id); |
|
if (!t) |
|
return ""; |
|
|
|
/* |
|
* The goal here is to build up the right number of pointer and |
|
* array suffixes while ensuring the type name for a typedef |
|
* is represented. Along the way we accumulate a list of |
|
* BTF kinds we have encountered, since these will inform later |
|
* display; for example, pointer types will not require an |
|
* opening "{" for struct, we will just display the pointer value. |
|
* |
|
* We also want to accumulate the right number of pointer or array |
|
* indices in the format string while iterating until we get to |
|
* the typedef/pointee/array member target type. |
|
* |
|
* We start by pointing at the end of pointer and array suffix |
|
* strings; as we accumulate pointers and arrays we move the pointer |
|
* or array string backwards so it will show the expected number of |
|
* '*' or '[]' for the type. BTF_SHOW_MAX_ITER of nesting of pointers |
|
* and/or arrays and typedefs are supported as a precaution. |
|
* |
|
* We also want to get typedef name while proceeding to resolve |
|
* type it points to so that we can add parentheses if it is a |
|
* "typedef struct" etc. |
|
*/ |
|
for (i = 0; i < BTF_SHOW_MAX_ITER; i++) { |
|
|
|
switch (BTF_INFO_KIND(t->info)) { |
|
case BTF_KIND_TYPEDEF: |
|
if (!name) |
|
name = btf_name_by_offset(show->btf, |
|
t->name_off); |
|
kinds |= BTF_KIND_BIT(BTF_KIND_TYPEDEF); |
|
id = t->type; |
|
break; |
|
case BTF_KIND_ARRAY: |
|
kinds |= BTF_KIND_BIT(BTF_KIND_ARRAY); |
|
parens = "["; |
|
if (!t) |
|
return ""; |
|
array = btf_type_array(t); |
|
if (array_suffix > array_suffixes) |
|
array_suffix -= 2; |
|
id = array->type; |
|
break; |
|
case BTF_KIND_PTR: |
|
kinds |= BTF_KIND_BIT(BTF_KIND_PTR); |
|
if (ptr_suffix > ptr_suffixes) |
|
ptr_suffix -= 1; |
|
id = t->type; |
|
break; |
|
default: |
|
id = 0; |
|
break; |
|
} |
|
if (!id) |
|
break; |
|
t = btf_type_skip_qualifiers(show->btf, id); |
|
} |
|
/* We may not be able to represent this type; bail to be safe */ |
|
if (i == BTF_SHOW_MAX_ITER) |
|
return ""; |
|
|
|
if (!name) |
|
name = btf_name_by_offset(show->btf, t->name_off); |
|
|
|
switch (BTF_INFO_KIND(t->info)) { |
|
case BTF_KIND_STRUCT: |
|
case BTF_KIND_UNION: |
|
prefix = BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT ? |
|
"struct" : "union"; |
|
/* if it's an array of struct/union, parens is already set */ |
|
if (!(kinds & (BTF_KIND_BIT(BTF_KIND_ARRAY)))) |
|
parens = "{"; |
|
break; |
|
case BTF_KIND_ENUM: |
|
prefix = "enum"; |
|
break; |
|
default: |
|
break; |
|
} |
|
|
|
/* pointer does not require parens */ |
|
if (kinds & BTF_KIND_BIT(BTF_KIND_PTR)) |
|
parens = ""; |
|
/* typedef does not require struct/union/enum prefix */ |
|
if (kinds & BTF_KIND_BIT(BTF_KIND_TYPEDEF)) |
|
prefix = ""; |
|
|
|
if (!name) |
|
name = ""; |
|
|
|
/* Even if we don't want type name info, we want parentheses etc */ |
|
if (show->flags & BTF_SHOW_NONAME) |
|
snprintf(show->state.name, sizeof(show->state.name), "%s", |
|
parens); |
|
else |
|
snprintf(show->state.name, sizeof(show->state.name), |
|
"%s%s%s(%s%s%s%s%s%s)%s", |
|
/* first 3 strings comprise ".member = " */ |
|
show_member ? "." : "", |
|
show_member ? member : "", |
|
show_member ? " = " : "", |
|
/* ...next is our prefix (struct, enum, etc) */ |
|
prefix, |
|
strlen(prefix) > 0 && strlen(name) > 0 ? " " : "", |
|
/* ...this is the type name itself */ |
|
name, |
|
/* ...suffixed by the appropriate '*', '[]' suffixes */ |
|
strlen(ptr_suffix) > 0 ? " " : "", ptr_suffix, |
|
array_suffix, parens); |
|
|
|
return show->state.name; |
|
} |
|
|
|
static const char *__btf_show_indent(struct btf_show *show) |
|
{ |
|
const char *indents = " "; |
|
const char *indent = &indents[strlen(indents)]; |
|
|
|
if ((indent - show->state.depth) >= indents) |
|
return indent - show->state.depth; |
|
return indents; |
|
} |
|
|
|
static const char *btf_show_indent(struct btf_show *show) |
|
{ |
|
return show->flags & BTF_SHOW_COMPACT ? "" : __btf_show_indent(show); |
|
} |
|
|
|
static const char *btf_show_newline(struct btf_show *show) |
|
{ |
|
return show->flags & BTF_SHOW_COMPACT ? "" : "\n"; |
|
} |
|
|
|
static const char *btf_show_delim(struct btf_show *show) |
|
{ |
|
if (show->state.depth == 0) |
|
return ""; |
|
|
|
if ((show->flags & BTF_SHOW_COMPACT) && show->state.type && |
|
BTF_INFO_KIND(show->state.type->info) == BTF_KIND_UNION) |
|
return "|"; |
|
|
|
return ","; |
|
} |
|
|
|
__printf(2, 3) static void btf_show(struct btf_show *show, const char *fmt, ...) |
|
{ |
|
va_list args; |
|
|
|
if (!show->state.depth_check) { |
|
va_start(args, fmt); |
|
show->showfn(show, fmt, args); |
|
va_end(args); |
|
} |
|
} |
|
|
|
/* Macros are used here as btf_show_type_value[s]() prepends and appends |
|
* format specifiers to the format specifier passed in; these do the work of |
|
* adding indentation, delimiters etc while the caller simply has to specify |
|
* the type value(s) in the format specifier + value(s). |
|
*/ |
|
#define btf_show_type_value(show, fmt, value) \ |
|
do { \ |
|
if ((value) != 0 || (show->flags & BTF_SHOW_ZERO) || \ |
|
show->state.depth == 0) { \ |
|
btf_show(show, "%s%s" fmt "%s%s", \ |
|
btf_show_indent(show), \ |
|
btf_show_name(show), \ |
|
value, btf_show_delim(show), \ |
|
btf_show_newline(show)); \ |
|
if (show->state.depth > show->state.depth_to_show) \ |
|
show->state.depth_to_show = show->state.depth; \ |
|
} \ |
|
} while (0) |
|
|
|
#define btf_show_type_values(show, fmt, ...) \ |
|
do { \ |
|
btf_show(show, "%s%s" fmt "%s%s", btf_show_indent(show), \ |
|
btf_show_name(show), \ |
|
__VA_ARGS__, btf_show_delim(show), \ |
|
btf_show_newline(show)); \ |
|
if (show->state.depth > show->state.depth_to_show) \ |
|
show->state.depth_to_show = show->state.depth; \ |
|
} while (0) |
|
|
|
/* How much is left to copy to safe buffer after @data? */ |
|
static int btf_show_obj_size_left(struct btf_show *show, void *data) |
|
{ |
|
return show->obj.head + show->obj.size - data; |
|
} |
|
|
|
/* Is object pointed to by @data of @size already copied to our safe buffer? */ |
|
static bool btf_show_obj_is_safe(struct btf_show *show, void *data, int size) |
|
{ |
|
return data >= show->obj.data && |
|
(data + size) < (show->obj.data + BTF_SHOW_OBJ_SAFE_SIZE); |
|
} |
|
|
|
/* |
|
* If object pointed to by @data of @size falls within our safe buffer, return |
|
* the equivalent pointer to the same safe data. Assumes |
|
* copy_from_kernel_nofault() has already happened and our safe buffer is |
|
* populated. |
|
*/ |
|
static void *__btf_show_obj_safe(struct btf_show *show, void *data, int size) |
|
{ |
|
if (btf_show_obj_is_safe(show, data, size)) |
|
return show->obj.safe + (data - show->obj.data); |
|
return NULL; |
|
} |
|
|
|
/* |
|
* Return a safe-to-access version of data pointed to by @data. |
|
* We do this by copying the relevant amount of information |
|
* to the struct btf_show obj.safe buffer using copy_from_kernel_nofault(). |
|
* |
|
* If BTF_SHOW_UNSAFE is specified, just return data as-is; no |
|
* safe copy is needed. |
|
* |
|
* Otherwise we need to determine if we have the required amount |
|
* of data (determined by the @data pointer and the size of the |
|
* largest base type we can encounter (represented by |
|
* BTF_SHOW_OBJ_BASE_TYPE_SIZE). Having that much data ensures |
|
* that we will be able to print some of the current object, |
|
* and if more is needed a copy will be triggered. |
|
* Some objects such as structs will not fit into the buffer; |
|
* in such cases additional copies when we iterate over their |
|
* members may be needed. |
|
* |
|
* btf_show_obj_safe() is used to return a safe buffer for |
|
* btf_show_start_type(); this ensures that as we recurse into |
|
* nested types we always have safe data for the given type. |
|
* This approach is somewhat wasteful; it's possible for example |
|
* that when iterating over a large union we'll end up copying the |
|
* same data repeatedly, but the goal is safety not performance. |
|
* We use stack data as opposed to per-CPU buffers because the |
|
* iteration over a type can take some time, and preemption handling |
|
* would greatly complicate use of the safe buffer. |
|
*/ |
|
static void *btf_show_obj_safe(struct btf_show *show, |
|
const struct btf_type *t, |
|
void *data) |
|
{ |
|
const struct btf_type *rt; |
|
int size_left, size; |
|
void *safe = NULL; |
|
|
|
if (show->flags & BTF_SHOW_UNSAFE) |
|
return data; |
|
|
|
rt = btf_resolve_size(show->btf, t, &size); |
|
if (IS_ERR(rt)) { |
|
show->state.status = PTR_ERR(rt); |
|
return NULL; |
|
} |
|
|
|
/* |
|
* Is this toplevel object? If so, set total object size and |
|
* initialize pointers. Otherwise check if we still fall within |
|
* our safe object data. |
|
*/ |
|
if (show->state.depth == 0) { |
|
show->obj.size = size; |
|
show->obj.head = data; |
|
} else { |
|
/* |
|
* If the size of the current object is > our remaining |
|
* safe buffer we _may_ need to do a new copy. However |
|
* consider the case of a nested struct; it's size pushes |
|
* us over the safe buffer limit, but showing any individual |
|
* struct members does not. In such cases, we don't need |
|
* to initiate a fresh copy yet; however we definitely need |
|
* at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes left |
|
* in our buffer, regardless of the current object size. |
|
* The logic here is that as we resolve types we will |
|
* hit a base type at some point, and we need to be sure |
|
* the next chunk of data is safely available to display |
|
* that type info safely. We cannot rely on the size of |
|
* the current object here because it may be much larger |
|
* than our current buffer (e.g. task_struct is 8k). |
|
* All we want to do here is ensure that we can print the |
|
* next basic type, which we can if either |
|
* - the current type size is within the safe buffer; or |
|
* - at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes are left in |
|
* the safe buffer. |
|
*/ |
|
safe = __btf_show_obj_safe(show, data, |
|
min(size, |
|
BTF_SHOW_OBJ_BASE_TYPE_SIZE)); |
|
} |
|
|
|
/* |
|
* We need a new copy to our safe object, either because we haven't |
|
* yet copied and are initializing safe data, or because the data |
|
* we want falls outside the boundaries of the safe object. |
|
*/ |
|
if (!safe) { |
|
size_left = btf_show_obj_size_left(show, data); |
|
if (size_left > BTF_SHOW_OBJ_SAFE_SIZE) |
|
size_left = BTF_SHOW_OBJ_SAFE_SIZE; |
|
show->state.status = copy_from_kernel_nofault(show->obj.safe, |
|
data, size_left); |
|
if (!show->state.status) { |
|
show->obj.data = data; |
|
safe = show->obj.safe; |
|
} |
|
} |
|
|
|
return safe; |
|
} |
|
|
|
/* |
|
* Set the type we are starting to show and return a safe data pointer |
|
* to be used for showing the associated data. |
|
*/ |
|
static void *btf_show_start_type(struct btf_show *show, |
|
const struct btf_type *t, |
|
u32 type_id, void *data) |
|
{ |
|
show->state.type = t; |
|
show->state.type_id = type_id; |
|
show->state.name[0] = '\0'; |
|
|
|
return btf_show_obj_safe(show, t, data); |
|
} |
|
|
|
static void btf_show_end_type(struct btf_show *show) |
|
{ |
|
show->state.type = NULL; |
|
show->state.type_id = 0; |
|
show->state.name[0] = '\0'; |
|
} |
|
|
|
static void *btf_show_start_aggr_type(struct btf_show *show, |
|
const struct btf_type *t, |
|
u32 type_id, void *data) |
|
{ |
|
void *safe_data = btf_show_start_type(show, t, type_id, data); |
|
|
|
if (!safe_data) |
|
return safe_data; |
|
|
|
btf_show(show, "%s%s%s", btf_show_indent(show), |
|
btf_show_name(show), |
|
btf_show_newline(show)); |
|
show->state.depth++; |
|
return safe_data; |
|
} |
|
|
|
static void btf_show_end_aggr_type(struct btf_show *show, |
|
const char *suffix) |
|
{ |
|
show->state.depth--; |
|
btf_show(show, "%s%s%s%s", btf_show_indent(show), suffix, |
|
btf_show_delim(show), btf_show_newline(show)); |
|
btf_show_end_type(show); |
|
} |
|
|
|
static void btf_show_start_member(struct btf_show *show, |
|
const struct btf_member *m) |
|
{ |
|
show->state.member = m; |
|
} |
|
|
|
static void btf_show_start_array_member(struct btf_show *show) |
|
{ |
|
show->state.array_member = 1; |
|
btf_show_start_member(show, NULL); |
|
} |
|
|
|
static void btf_show_end_member(struct btf_show *show) |
|
{ |
|
show->state.member = NULL; |
|
} |
|
|
|
static void btf_show_end_array_member(struct btf_show *show) |
|
{ |
|
show->state.array_member = 0; |
|
btf_show_end_member(show); |
|
} |
|
|
|
static void *btf_show_start_array_type(struct btf_show *show, |
|
const struct btf_type *t, |
|
u32 type_id, |
|
u16 array_encoding, |
|
void *data) |
|
{ |
|
show->state.array_encoding = array_encoding; |
|
show->state.array_terminated = 0; |
|
return btf_show_start_aggr_type(show, t, type_id, data); |
|
} |
|
|
|
static void btf_show_end_array_type(struct btf_show *show) |
|
{ |
|
show->state.array_encoding = 0; |
|
show->state.array_terminated = 0; |
|
btf_show_end_aggr_type(show, "]"); |
|
} |
|
|
|
static void *btf_show_start_struct_type(struct btf_show *show, |
|
const struct btf_type *t, |
|
u32 type_id, |
|
void *data) |
|
{ |
|
return btf_show_start_aggr_type(show, t, type_id, data); |
|
} |
|
|
|
static void btf_show_end_struct_type(struct btf_show *show) |
|
{ |
|
btf_show_end_aggr_type(show, "}"); |
|
} |
|
|
|
__printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log, |
|
const char *fmt, ...) |
|
{ |
|
va_list args; |
|
|
|
va_start(args, fmt); |
|
bpf_verifier_vlog(log, fmt, args); |
|
va_end(args); |
|
} |
|
|
|
__printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env, |
|
const char *fmt, ...) |
|
{ |
|
struct bpf_verifier_log *log = &env->log; |
|
va_list args; |
|
|
|
if (!bpf_verifier_log_needed(log)) |
|
return; |
|
|
|
va_start(args, fmt); |
|
bpf_verifier_vlog(log, fmt, args); |
|
va_end(args); |
|
} |
|
|
|
__printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env, |
|
const struct btf_type *t, |
|
bool log_details, |
|
const char *fmt, ...) |
|
{ |
|
struct bpf_verifier_log *log = &env->log; |
|
u8 kind = BTF_INFO_KIND(t->info); |
|
struct btf *btf = env->btf; |
|
va_list args; |
|
|
|
if (!bpf_verifier_log_needed(log)) |
|
return; |
|
|
|
/* btf verifier prints all types it is processing via |
|
* btf_verifier_log_type(..., fmt = NULL). |
|
* Skip those prints for in-kernel BTF verification. |
|
*/ |
|
if (log->level == BPF_LOG_KERNEL && !fmt) |
|
return; |
|
|
|
__btf_verifier_log(log, "[%u] %s %s%s", |
|
env->log_type_id, |
|
btf_kind_str[kind], |
|
__btf_name_by_offset(btf, t->name_off), |
|
log_details ? " " : ""); |
|
|
|
if (log_details) |
|
btf_type_ops(t)->log_details(env, t); |
|
|
|
if (fmt && *fmt) { |
|
__btf_verifier_log(log, " "); |
|
va_start(args, fmt); |
|
bpf_verifier_vlog(log, fmt, args); |
|
va_end(args); |
|
} |
|
|
|
__btf_verifier_log(log, "\n"); |
|
} |
|
|
|
#define btf_verifier_log_type(env, t, ...) \ |
|
__btf_verifier_log_type((env), (t), true, __VA_ARGS__) |
|
#define btf_verifier_log_basic(env, t, ...) \ |
|
__btf_verifier_log_type((env), (t), false, __VA_ARGS__) |
|
|
|
__printf(4, 5) |
|
static void btf_verifier_log_member(struct btf_verifier_env *env, |
|
const struct btf_type *struct_type, |
|
const struct btf_member *member, |
|
const char *fmt, ...) |
|
{ |
|
struct bpf_verifier_log *log = &env->log; |
|
struct btf *btf = env->btf; |
|
va_list args; |
|
|
|
if (!bpf_verifier_log_needed(log)) |
|
return; |
|
|
|
if (log->level == BPF_LOG_KERNEL && !fmt) |
|
return; |
|
/* The CHECK_META phase already did a btf dump. |
|
* |
|
* If member is logged again, it must hit an error in |
|
* parsing this member. It is useful to print out which |
|
* struct this member belongs to. |
|
*/ |
|
if (env->phase != CHECK_META) |
|
btf_verifier_log_type(env, struct_type, NULL); |
|
|
|
if (btf_type_kflag(struct_type)) |
|
__btf_verifier_log(log, |
|
"\t%s type_id=%u bitfield_size=%u bits_offset=%u", |
|
__btf_name_by_offset(btf, member->name_off), |
|
member->type, |
|
BTF_MEMBER_BITFIELD_SIZE(member->offset), |
|
BTF_MEMBER_BIT_OFFSET(member->offset)); |
|
else |
|
__btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u", |
|
__btf_name_by_offset(btf, member->name_off), |
|
member->type, member->offset); |
|
|
|
if (fmt && *fmt) { |
|
__btf_verifier_log(log, " "); |
|
va_start(args, fmt); |
|
bpf_verifier_vlog(log, fmt, args); |
|
va_end(args); |
|
} |
|
|
|
__btf_verifier_log(log, "\n"); |
|
} |
|
|
|
__printf(4, 5) |
|
static void btf_verifier_log_vsi(struct btf_verifier_env *env, |
|
const struct btf_type *datasec_type, |
|
const struct btf_var_secinfo *vsi, |
|
const char *fmt, ...) |
|
{ |
|
struct bpf_verifier_log *log = &env->log; |
|
va_list args; |
|
|
|
if (!bpf_verifier_log_needed(log)) |
|
return; |
|
if (log->level == BPF_LOG_KERNEL && !fmt) |
|
return; |
|
if (env->phase != CHECK_META) |
|
btf_verifier_log_type(env, datasec_type, NULL); |
|
|
|
__btf_verifier_log(log, "\t type_id=%u offset=%u size=%u", |
|
vsi->type, vsi->offset, vsi->size); |
|
if (fmt && *fmt) { |
|
__btf_verifier_log(log, " "); |
|
va_start(args, fmt); |
|
bpf_verifier_vlog(log, fmt, args); |
|
va_end(args); |
|
} |
|
|
|
__btf_verifier_log(log, "\n"); |
|
} |
|
|
|
static void btf_verifier_log_hdr(struct btf_verifier_env *env, |
|
u32 btf_data_size) |
|
{ |
|
struct bpf_verifier_log *log = &env->log; |
|
const struct btf *btf = env->btf; |
|
const struct btf_header *hdr; |
|
|
|
if (!bpf_verifier_log_needed(log)) |
|
return; |
|
|
|
if (log->level == BPF_LOG_KERNEL) |
|
return; |
|
hdr = &btf->hdr; |
|
__btf_verifier_log(log, "magic: 0x%x\n", hdr->magic); |
|
__btf_verifier_log(log, "version: %u\n", hdr->version); |
|
__btf_verifier_log(log, "flags: 0x%x\n", hdr->flags); |
|
__btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len); |
|
__btf_verifier_log(log, "type_off: %u\n", hdr->type_off); |
|
__btf_verifier_log(log, "type_len: %u\n", hdr->type_len); |
|
__btf_verifier_log(log, "str_off: %u\n", hdr->str_off); |
|
__btf_verifier_log(log, "str_len: %u\n", hdr->str_len); |
|
__btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size); |
|
} |
|
|
|
static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t) |
|
{ |
|
struct btf *btf = env->btf; |
|
|
|
if (btf->types_size == btf->nr_types) { |
|
/* Expand 'types' array */ |
|
|
|
struct btf_type **new_types; |
|
u32 expand_by, new_size; |
|
|
|
if (btf->start_id + btf->types_size == BTF_MAX_TYPE) { |
|
btf_verifier_log(env, "Exceeded max num of types"); |
|
return -E2BIG; |
|
} |
|
|
|
expand_by = max_t(u32, btf->types_size >> 2, 16); |
|
new_size = min_t(u32, BTF_MAX_TYPE, |
|
btf->types_size + expand_by); |
|
|
|
new_types = kvcalloc(new_size, sizeof(*new_types), |
|
GFP_KERNEL | __GFP_NOWARN); |
|
if (!new_types) |
|
return -ENOMEM; |
|
|
|
if (btf->nr_types == 0) { |
|
if (!btf->base_btf) { |
|
/* lazily init VOID type */ |
|
new_types[0] = &btf_void; |
|
btf->nr_types++; |
|
} |
|
} else { |
|
memcpy(new_types, btf->types, |
|
sizeof(*btf->types) * btf->nr_types); |
|
} |
|
|
|
kvfree(btf->types); |
|
btf->types = new_types; |
|
btf->types_size = new_size; |
|
} |
|
|
|
btf->types[btf->nr_types++] = t; |
|
|
|
return 0; |
|
} |
|
|
|
static int btf_alloc_id(struct btf *btf) |
|
{ |
|
int id; |
|
|
|
idr_preload(GFP_KERNEL); |
|
spin_lock_bh(&btf_idr_lock); |
|
id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC); |
|
if (id > 0) |
|
btf->id = id; |
|
spin_unlock_bh(&btf_idr_lock); |
|
idr_preload_end(); |
|
|
|
if (WARN_ON_ONCE(!id)) |
|
return -ENOSPC; |
|
|
|
return id > 0 ? 0 : id; |
|
} |
|
|
|
static void btf_free_id(struct btf *btf) |
|
{ |
|
unsigned long flags; |
|
|
|
/* |
|
* In map-in-map, calling map_delete_elem() on outer |
|
* map will call bpf_map_put on the inner map. |
|
* It will then eventually call btf_free_id() |
|
* on the inner map. Some of the map_delete_elem() |
|
* implementation may have irq disabled, so |
|
* we need to use the _irqsave() version instead |
|
* of the _bh() version. |
|
*/ |
|
spin_lock_irqsave(&btf_idr_lock, flags); |
|
idr_remove(&btf_idr, btf->id); |
|
spin_unlock_irqrestore(&btf_idr_lock, flags); |
|
} |
|
|
|
static void btf_free_kfunc_set_tab(struct btf *btf) |
|
{ |
|
struct btf_kfunc_set_tab *tab = btf->kfunc_set_tab; |
|
int hook, type; |
|
|
|
if (!tab) |
|
return; |
|
/* For module BTF, we directly assign the sets being registered, so |
|
* there is nothing to free except kfunc_set_tab. |
|
*/ |
|
if (btf_is_module(btf)) |
|
goto free_tab; |
|
for (hook = 0; hook < ARRAY_SIZE(tab->sets); hook++) { |
|
for (type = 0; type < ARRAY_SIZE(tab->sets[0]); type++) |
|
kfree(tab->sets[hook][type]); |
|
} |
|
free_tab: |
|
kfree(tab); |
|
btf->kfunc_set_tab = NULL; |
|
} |
|
|
|
static void btf_free(struct btf *btf) |
|
{ |
|
btf_free_kfunc_set_tab(btf); |
|
kvfree(btf->types); |
|
kvfree(btf->resolved_sizes); |
|
kvfree(btf->resolved_ids); |
|
kvfree(btf->data); |
|
kfree(btf); |
|
} |
|
|
|
static void btf_free_rcu(struct rcu_head *rcu) |
|
{ |
|
struct btf *btf = container_of(rcu, struct btf, rcu); |
|
|
|
btf_free(btf); |
|
} |
|
|
|
void btf_get(struct btf *btf) |
|
{ |
|
refcount_inc(&btf->refcnt); |
|
} |
|
|
|
void btf_put(struct btf *btf) |
|
{ |
|
if (btf && refcount_dec_and_test(&btf->refcnt)) { |
|
btf_free_id(btf); |
|
call_rcu(&btf->rcu, btf_free_rcu); |
|
} |
|
} |
|
|
|
static int env_resolve_init(struct btf_verifier_env *env) |
|
{ |
|
struct btf *btf = env->btf; |
|
u32 nr_types = btf->nr_types; |
|
u32 *resolved_sizes = NULL; |
|
u32 *resolved_ids = NULL; |
|
u8 *visit_states = NULL; |
|
|
|
resolved_sizes = kvcalloc(nr_types, sizeof(*resolved_sizes), |
|
GFP_KERNEL | __GFP_NOWARN); |
|
if (!resolved_sizes) |
|
goto nomem; |
|
|
|
resolved_ids = kvcalloc(nr_types, sizeof(*resolved_ids), |
|
GFP_KERNEL | __GFP_NOWARN); |
|
if (!resolved_ids) |
|
goto nomem; |
|
|
|
visit_states = kvcalloc(nr_types, sizeof(*visit_states), |
|
GFP_KERNEL | __GFP_NOWARN); |
|
if (!visit_states) |
|
goto nomem; |
|
|
|
btf->resolved_sizes = resolved_sizes; |
|
btf->resolved_ids = resolved_ids; |
|
env->visit_states = visit_states; |
|
|
|
return 0; |
|
|
|
nomem: |
|
kvfree(resolved_sizes); |
|
kvfree(resolved_ids); |
|
kvfree(visit_states); |
|
return -ENOMEM; |
|
} |
|
|
|
static void btf_verifier_env_free(struct btf_verifier_env *env) |
|
{ |
|
kvfree(env->visit_states); |
|
kfree(env); |
|
} |
|
|
|
static bool env_type_is_resolve_sink(const struct btf_verifier_env *env, |
|
const struct btf_type *next_type) |
|
{ |
|
switch (env->resolve_mode) { |
|
case RESOLVE_TBD: |
|
/* int, enum or void is a sink */ |
|
return !btf_type_needs_resolve(next_type); |
|
case RESOLVE_PTR: |
|
/* int, enum, void, struct, array, func or func_proto is a sink |
|
* for ptr |
|
*/ |
|
return !btf_type_is_modifier(next_type) && |
|
!btf_type_is_ptr(next_type); |
|
case RESOLVE_STRUCT_OR_ARRAY: |
|
/* int, enum, void, ptr, func or func_proto is a sink |
|
* for struct and array |
|
*/ |
|
return !btf_type_is_modifier(next_type) && |
|
!btf_type_is_array(next_type) && |
|
!btf_type_is_struct(next_type); |
|
default: |
|
BUG(); |
|
} |
|
} |
|
|
|
static bool env_type_is_resolved(const struct btf_verifier_env *env, |
|
u32 type_id) |
|
{ |
|
/* base BTF types should be resolved by now */ |
|
if (type_id < env->btf->start_id) |
|
return true; |
|
|
|
return env->visit_states[type_id - env->btf->start_id] == RESOLVED; |
|
} |
|
|
|
static int env_stack_push(struct btf_verifier_env *env, |
|
const struct btf_type *t, u32 type_id) |
|
{ |
|
const struct btf *btf = env->btf; |
|
struct resolve_vertex *v; |
|
|
|
if (env->top_stack == MAX_RESOLVE_DEPTH) |
|
return -E2BIG; |
|
|
|
if (type_id < btf->start_id |
|
|| env->visit_states[type_id - btf->start_id] != NOT_VISITED) |
|
return -EEXIST; |
|
|
|
env->visit_states[type_id - btf->start_id] = VISITED; |
|
|
|
v = &env->stack[env->top_stack++]; |
|
v->t = t; |
|
v->type_id = type_id; |
|
v->next_member = 0; |
|
|
|
if (env->resolve_mode == RESOLVE_TBD) { |
|
if (btf_type_is_ptr(t)) |
|
env->resolve_mode = RESOLVE_PTR; |
|
else if (btf_type_is_struct(t) || btf_type_is_array(t)) |
|
env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void env_stack_set_next_member(struct btf_verifier_env *env, |
|
u16 next_member) |
|
{ |
|
env->stack[env->top_stack - 1].next_member = next_member; |
|
} |
|
|
|
static void env_stack_pop_resolved(struct btf_verifier_env *env, |
|
u32 resolved_type_id, |
|
u32 resolved_size) |
|
{ |
|
u32 type_id = env->stack[--(env->top_stack)].type_id; |
|
struct btf *btf = env->btf; |
|
|
|
type_id -= btf->start_id; /* adjust to local type id */ |
|
btf->resolved_sizes[type_id] = resolved_size; |
|
btf->resolved_ids[type_id] = resolved_type_id; |
|
env->visit_states[type_id] = RESOLVED; |
|
} |
|
|
|
static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env) |
|
{ |
|
return env->top_stack ? &env->stack[env->top_stack - 1] : NULL; |
|
} |
|
|
|
/* Resolve the size of a passed-in "type" |
|
* |
|
* type: is an array (e.g. u32 array[x][y]) |
|
* return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY, |
|
* *type_size: (x * y * sizeof(u32)). Hence, *type_size always |
|
* corresponds to the return type. |
|
* *elem_type: u32 |
|
* *elem_id: id of u32 |
|
* *total_nelems: (x * y). Hence, individual elem size is |
|
* (*type_size / *total_nelems) |
|
* *type_id: id of type if it's changed within the function, 0 if not |
|
* |
|
* type: is not an array (e.g. const struct X) |
|
* return type: type "struct X" |
|
* *type_size: sizeof(struct X) |
|
* *elem_type: same as return type ("struct X") |
|
* *elem_id: 0 |
|
* *total_nelems: 1 |
|
* *type_id: id of type if it's changed within the function, 0 if not |
|
*/ |
|
static const struct btf_type * |
|
__btf_resolve_size(const struct btf *btf, const struct btf_type *type, |
|
u32 *type_size, const struct btf_type **elem_type, |
|
u32 *elem_id, u32 *total_nelems, u32 *type_id) |
|
{ |
|
const struct btf_type *array_type = NULL; |
|
const struct btf_array *array = NULL; |
|
u32 i, size, nelems = 1, id = 0; |
|
|
|
for (i = 0; i < MAX_RESOLVE_DEPTH; i++) { |
|
switch (BTF_INFO_KIND(type->info)) { |
|
/* type->size can be used */ |
|
case BTF_KIND_INT: |
|
case BTF_KIND_STRUCT: |
|
case BTF_KIND_UNION: |
|
case BTF_KIND_ENUM: |
|
case BTF_KIND_FLOAT: |
|
size = type->size; |
|
goto resolved; |
|
|
|
case BTF_KIND_PTR: |
|
size = sizeof(void *); |
|
goto resolved; |
|
|
|
/* Modifiers */ |
|
case BTF_KIND_TYPEDEF: |
|
case BTF_KIND_VOLATILE: |
|
case BTF_KIND_CONST: |
|
case BTF_KIND_RESTRICT: |
|
case BTF_KIND_TYPE_TAG: |
|
id = type->type; |
|
type = btf_type_by_id(btf, type->type); |
|
break; |
|
|
|
case BTF_KIND_ARRAY: |
|
if (!array_type) |
|
array_type = type; |
|
array = btf_type_array(type); |
|
if (nelems && array->nelems > U32_MAX / nelems) |
|
return ERR_PTR(-EINVAL); |
|
nelems *= array->nelems; |
|
type = btf_type_by_id(btf, array->type); |
|
break; |
|
|
|
/* type without size */ |
|
default: |
|
return ERR_PTR(-EINVAL); |
|
} |
|
} |
|
|
|
return ERR_PTR(-EINVAL); |
|
|
|
resolved: |
|
if (nelems && size > U32_MAX / nelems) |
|
return ERR_PTR(-EINVAL); |
|
|
|
*type_size = nelems * size; |
|
if (total_nelems) |
|
*total_nelems = nelems; |
|
if (elem_type) |
|
*elem_type = type; |
|
if (elem_id) |
|
*elem_id = array ? array->type : 0; |
|
if (type_id && id) |
|
*type_id = id; |
|
|
|
return array_type ? : type; |
|
} |
|
|
|
const struct btf_type * |
|
btf_resolve_size(const struct btf *btf, const struct btf_type *type, |
|
u32 *type_size) |
|
{ |
|
return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL); |
|
} |
|
|
|
static u32 btf_resolved_type_id(const struct btf *btf, u32 type_id) |
|
{ |
|
while (type_id < btf->start_id) |
|
btf = btf->base_btf; |
|
|
|
return btf->resolved_ids[type_id - btf->start_id]; |
|
} |
|
|
|
/* The input param "type_id" must point to a needs_resolve type */ |
|
static const struct btf_type *btf_type_id_resolve(const struct btf *btf, |
|
u32 *type_id) |
|
{ |
|
*type_id = btf_resolved_type_id(btf, *type_id); |
|
return btf_type_by_id(btf, *type_id); |
|
} |
|
|
|
static u32 btf_resolved_type_size(const struct btf *btf, u32 type_id) |
|
{ |
|
while (type_id < btf->start_id) |
|
btf = btf->base_btf; |
|
|
|
return btf->resolved_sizes[type_id - btf->start_id]; |
|
} |
|
|
|
const struct btf_type *btf_type_id_size(const struct btf *btf, |
|
u32 *type_id, u32 *ret_size) |
|
{ |
|
const struct btf_type *size_type; |
|
u32 size_type_id = *type_id; |
|
u32 size = 0; |
|
|
|
size_type = btf_type_by_id(btf, size_type_id); |
|
if (btf_type_nosize_or_null(size_type)) |
|
return NULL; |
|
|
|
if (btf_type_has_size(size_type)) { |
|
size = size_type->size; |
|
} else if (btf_type_is_array(size_type)) { |
|
size = btf_resolved_type_size(btf, size_type_id); |
|
} else if (btf_type_is_ptr(size_type)) { |
|
size = sizeof(void *); |
|
} else { |
|
if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) && |
|
!btf_type_is_var(size_type))) |
|
return NULL; |
|
|
|
size_type_id = btf_resolved_type_id(btf, size_type_id); |
|
size_type = btf_type_by_id(btf, size_type_id); |
|
if (btf_type_nosize_or_null(size_type)) |
|
return NULL; |
|
else if (btf_type_has_size(size_type)) |
|
size = size_type->size; |
|
else if (btf_type_is_array(size_type)) |
|
size = btf_resolved_type_size(btf, size_type_id); |
|
else if (btf_type_is_ptr(size_type)) |
|
size = sizeof(void *); |
|
else |
|
return NULL; |
|
} |
|
|
|
*type_id = size_type_id; |
|
if (ret_size) |
|
*ret_size = size; |
|
|
|
return size_type; |
|
} |
|
|
|
static int btf_df_check_member(struct btf_verifier_env *env, |
|
const struct btf_type *struct_type, |
|
const struct btf_member *member, |
|
const struct btf_type *member_type) |
|
{ |
|
btf_verifier_log_basic(env, struct_type, |
|
"Unsupported check_member"); |
|
return -EINVAL; |
|
} |
|
|
|
static int btf_df_check_kflag_member(struct btf_verifier_env *env, |
|
const struct btf_type *struct_type, |
|
const struct btf_member *member, |
|
const struct btf_type *member_type) |
|
{ |
|
btf_verifier_log_basic(env, struct_type, |
|
"Unsupported check_kflag_member"); |
|
return -EINVAL; |
|
} |
|
|
|
/* Used for ptr, array struct/union and float type members. |
|
* int, enum and modifier types have their specific callback functions. |
|
*/ |
|
static int btf_generic_check_kflag_member(struct btf_verifier_env *env, |
|
const struct btf_type *struct_type, |
|
const struct btf_member *member, |
|
const struct btf_type *member_type) |
|
{ |
|
if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Invalid member bitfield_size"); |
|
return -EINVAL; |
|
} |
|
|
|
/* bitfield size is 0, so member->offset represents bit offset only. |
|
* It is safe to call non kflag check_member variants. |
|
*/ |
|
return btf_type_ops(member_type)->check_member(env, struct_type, |
|
member, |
|
member_type); |
|
} |
|
|
|
static int btf_df_resolve(struct btf_verifier_env *env, |
|
const struct resolve_vertex *v) |
|
{ |
|
btf_verifier_log_basic(env, v->t, "Unsupported resolve"); |
|
return -EINVAL; |
|
} |
|
|
|
static void btf_df_show(const struct btf *btf, const struct btf_type *t, |
|
u32 type_id, void *data, u8 bits_offsets, |
|
struct btf_show *show) |
|
{ |
|
btf_show(show, "<unsupported kind:%u>", BTF_INFO_KIND(t->info)); |
|
} |
|
|
|
static int btf_int_check_member(struct btf_verifier_env *env, |
|
const struct btf_type *struct_type, |
|
const struct btf_member *member, |
|
const struct btf_type *member_type) |
|
{ |
|
u32 int_data = btf_type_int(member_type); |
|
u32 struct_bits_off = member->offset; |
|
u32 struct_size = struct_type->size; |
|
u32 nr_copy_bits; |
|
u32 bytes_offset; |
|
|
|
if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"bits_offset exceeds U32_MAX"); |
|
return -EINVAL; |
|
} |
|
|
|
struct_bits_off += BTF_INT_OFFSET(int_data); |
|
bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
|
nr_copy_bits = BTF_INT_BITS(int_data) + |
|
BITS_PER_BYTE_MASKED(struct_bits_off); |
|
|
|
if (nr_copy_bits > BITS_PER_U128) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"nr_copy_bits exceeds 128"); |
|
return -EINVAL; |
|
} |
|
|
|
if (struct_size < bytes_offset || |
|
struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Member exceeds struct_size"); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int btf_int_check_kflag_member(struct btf_verifier_env *env, |
|
const struct btf_type *struct_type, |
|
const struct btf_member *member, |
|
const struct btf_type *member_type) |
|
{ |
|
u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset; |
|
u32 int_data = btf_type_int(member_type); |
|
u32 struct_size = struct_type->size; |
|
u32 nr_copy_bits; |
|
|
|
/* a regular int type is required for the kflag int member */ |
|
if (!btf_type_int_is_regular(member_type)) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Invalid member base type"); |
|
return -EINVAL; |
|
} |
|
|
|
/* check sanity of bitfield size */ |
|
nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); |
|
struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); |
|
nr_int_data_bits = BTF_INT_BITS(int_data); |
|
if (!nr_bits) { |
|
/* Not a bitfield member, member offset must be at byte |
|
* boundary. |
|
*/ |
|
if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Invalid member offset"); |
|
return -EINVAL; |
|
} |
|
|
|
nr_bits = nr_int_data_bits; |
|
} else if (nr_bits > nr_int_data_bits) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Invalid member bitfield_size"); |
|
return -EINVAL; |
|
} |
|
|
|
bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
|
nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off); |
|
if (nr_copy_bits > BITS_PER_U128) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"nr_copy_bits exceeds 128"); |
|
return -EINVAL; |
|
} |
|
|
|
if (struct_size < bytes_offset || |
|
struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Member exceeds struct_size"); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static s32 btf_int_check_meta(struct btf_verifier_env *env, |
|
const struct btf_type *t, |
|
u32 meta_left) |
|
{ |
|
u32 int_data, nr_bits, meta_needed = sizeof(int_data); |
|
u16 encoding; |
|
|
|
if (meta_left < meta_needed) { |
|
btf_verifier_log_basic(env, t, |
|
"meta_left:%u meta_needed:%u", |
|
meta_left, meta_needed); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_vlen(t)) { |
|
btf_verifier_log_type(env, t, "vlen != 0"); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_kflag(t)) { |
|
btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
|
return -EINVAL; |
|
} |
|
|
|
int_data = btf_type_int(t); |
|
if (int_data & ~BTF_INT_MASK) { |
|
btf_verifier_log_basic(env, t, "Invalid int_data:%x", |
|
int_data); |
|
return -EINVAL; |
|
} |
|
|
|
nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data); |
|
|
|
if (nr_bits > BITS_PER_U128) { |
|
btf_verifier_log_type(env, t, "nr_bits exceeds %zu", |
|
BITS_PER_U128); |
|
return -EINVAL; |
|
} |
|
|
|
if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) { |
|
btf_verifier_log_type(env, t, "nr_bits exceeds type_size"); |
|
return -EINVAL; |
|
} |
|
|
|
/* |
|
* Only one of the encoding bits is allowed and it |
|
* should be sufficient for the pretty print purpose (i.e. decoding). |
|
* Multiple bits can be allowed later if it is found |
|
* to be insufficient. |
|
*/ |
|
encoding = BTF_INT_ENCODING(int_data); |
|
if (encoding && |
|
encoding != BTF_INT_SIGNED && |
|
encoding != BTF_INT_CHAR && |
|
encoding != BTF_INT_BOOL) { |
|
btf_verifier_log_type(env, t, "Unsupported encoding"); |
|
return -ENOTSUPP; |
|
} |
|
|
|
btf_verifier_log_type(env, t, NULL); |
|
|
|
return meta_needed; |
|
} |
|
|
|
static void btf_int_log(struct btf_verifier_env *env, |
|
const struct btf_type *t) |
|
{ |
|
int int_data = btf_type_int(t); |
|
|
|
btf_verifier_log(env, |
|
"size=%u bits_offset=%u nr_bits=%u encoding=%s", |
|
t->size, BTF_INT_OFFSET(int_data), |
|
BTF_INT_BITS(int_data), |
|
btf_int_encoding_str(BTF_INT_ENCODING(int_data))); |
|
} |
|
|
|
static void btf_int128_print(struct btf_show *show, void *data) |
|
{ |
|
/* data points to a __int128 number. |
|
* Suppose |
|
* int128_num = *(__int128 *)data; |
|
* The below formulas shows what upper_num and lower_num represents: |
|
* upper_num = int128_num >> 64; |
|
* lower_num = int128_num & 0xffffffffFFFFFFFFULL; |
|
*/ |
|
u64 upper_num, lower_num; |
|
|
|
#ifdef __BIG_ENDIAN_BITFIELD |
|
upper_num = *(u64 *)data; |
|
lower_num = *(u64 *)(data + 8); |
|
#else |
|
upper_num = *(u64 *)(data + 8); |
|
lower_num = *(u64 *)data; |
|
#endif |
|
if (upper_num == 0) |
|
btf_show_type_value(show, "0x%llx", lower_num); |
|
else |
|
btf_show_type_values(show, "0x%llx%016llx", upper_num, |
|
lower_num); |
|
} |
|
|
|
static void btf_int128_shift(u64 *print_num, u16 left_shift_bits, |
|
u16 right_shift_bits) |
|
{ |
|
u64 upper_num, lower_num; |
|
|
|
#ifdef __BIG_ENDIAN_BITFIELD |
|
upper_num = print_num[0]; |
|
lower_num = print_num[1]; |
|
#else |
|
upper_num = print_num[1]; |
|
lower_num = print_num[0]; |
|
#endif |
|
|
|
/* shake out un-needed bits by shift/or operations */ |
|
if (left_shift_bits >= 64) { |
|
upper_num = lower_num << (left_shift_bits - 64); |
|
lower_num = 0; |
|
} else { |
|
upper_num = (upper_num << left_shift_bits) | |
|
(lower_num >> (64 - left_shift_bits)); |
|
lower_num = lower_num << left_shift_bits; |
|
} |
|
|
|
if (right_shift_bits >= 64) { |
|
lower_num = upper_num >> (right_shift_bits - 64); |
|
upper_num = 0; |
|
} else { |
|
lower_num = (lower_num >> right_shift_bits) | |
|
(upper_num << (64 - right_shift_bits)); |
|
upper_num = upper_num >> right_shift_bits; |
|
} |
|
|
|
#ifdef __BIG_ENDIAN_BITFIELD |
|
print_num[0] = upper_num; |
|
print_num[1] = lower_num; |
|
#else |
|
print_num[0] = lower_num; |
|
print_num[1] = upper_num; |
|
#endif |
|
} |
|
|
|
static void btf_bitfield_show(void *data, u8 bits_offset, |
|
u8 nr_bits, struct btf_show *show) |
|
{ |
|
u16 left_shift_bits, right_shift_bits; |
|
u8 nr_copy_bytes; |
|
u8 nr_copy_bits; |
|
u64 print_num[2] = {}; |
|
|
|
nr_copy_bits = nr_bits + bits_offset; |
|
nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits); |
|
|
|
memcpy(print_num, data, nr_copy_bytes); |
|
|
|
#ifdef __BIG_ENDIAN_BITFIELD |
|
left_shift_bits = bits_offset; |
|
#else |
|
left_shift_bits = BITS_PER_U128 - nr_copy_bits; |
|
#endif |
|
right_shift_bits = BITS_PER_U128 - nr_bits; |
|
|
|
btf_int128_shift(print_num, left_shift_bits, right_shift_bits); |
|
btf_int128_print(show, print_num); |
|
} |
|
|
|
|
|
static void btf_int_bits_show(const struct btf *btf, |
|
const struct btf_type *t, |
|
void *data, u8 bits_offset, |
|
struct btf_show *show) |
|
{ |
|
u32 int_data = btf_type_int(t); |
|
u8 nr_bits = BTF_INT_BITS(int_data); |
|
u8 total_bits_offset; |
|
|
|
/* |
|
* bits_offset is at most 7. |
|
* BTF_INT_OFFSET() cannot exceed 128 bits. |
|
*/ |
|
total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data); |
|
data += BITS_ROUNDDOWN_BYTES(total_bits_offset); |
|
bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset); |
|
btf_bitfield_show(data, bits_offset, nr_bits, show); |
|
} |
|
|
|
static void btf_int_show(const struct btf *btf, const struct btf_type *t, |
|
u32 type_id, void *data, u8 bits_offset, |
|
struct btf_show *show) |
|
{ |
|
u32 int_data = btf_type_int(t); |
|
u8 encoding = BTF_INT_ENCODING(int_data); |
|
bool sign = encoding & BTF_INT_SIGNED; |
|
u8 nr_bits = BTF_INT_BITS(int_data); |
|
void *safe_data; |
|
|
|
safe_data = btf_show_start_type(show, t, type_id, data); |
|
if (!safe_data) |
|
return; |
|
|
|
if (bits_offset || BTF_INT_OFFSET(int_data) || |
|
BITS_PER_BYTE_MASKED(nr_bits)) { |
|
btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
|
goto out; |
|
} |
|
|
|
switch (nr_bits) { |
|
case 128: |
|
btf_int128_print(show, safe_data); |
|
break; |
|
case 64: |
|
if (sign) |
|
btf_show_type_value(show, "%lld", *(s64 *)safe_data); |
|
else |
|
btf_show_type_value(show, "%llu", *(u64 *)safe_data); |
|
break; |
|
case 32: |
|
if (sign) |
|
btf_show_type_value(show, "%d", *(s32 *)safe_data); |
|
else |
|
btf_show_type_value(show, "%u", *(u32 *)safe_data); |
|
break; |
|
case 16: |
|
if (sign) |
|
btf_show_type_value(show, "%d", *(s16 *)safe_data); |
|
else |
|
btf_show_type_value(show, "%u", *(u16 *)safe_data); |
|
break; |
|
case 8: |
|
if (show->state.array_encoding == BTF_INT_CHAR) { |
|
/* check for null terminator */ |
|
if (show->state.array_terminated) |
|
break; |
|
if (*(char *)data == '\0') { |
|
show->state.array_terminated = 1; |
|
break; |
|
} |
|
if (isprint(*(char *)data)) { |
|
btf_show_type_value(show, "'%c'", |
|
*(char *)safe_data); |
|
break; |
|
} |
|
} |
|
if (sign) |
|
btf_show_type_value(show, "%d", *(s8 *)safe_data); |
|
else |
|
btf_show_type_value(show, "%u", *(u8 *)safe_data); |
|
break; |
|
default: |
|
btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
|
break; |
|
} |
|
out: |
|
btf_show_end_type(show); |
|
} |
|
|
|
static const struct btf_kind_operations int_ops = { |
|
.check_meta = btf_int_check_meta, |
|
.resolve = btf_df_resolve, |
|
.check_member = btf_int_check_member, |
|
.check_kflag_member = btf_int_check_kflag_member, |
|
.log_details = btf_int_log, |
|
.show = btf_int_show, |
|
}; |
|
|
|
static int btf_modifier_check_member(struct btf_verifier_env *env, |
|
const struct btf_type *struct_type, |
|
const struct btf_member *member, |
|
const struct btf_type *member_type) |
|
{ |
|
const struct btf_type *resolved_type; |
|
u32 resolved_type_id = member->type; |
|
struct btf_member resolved_member; |
|
struct btf *btf = env->btf; |
|
|
|
resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); |
|
if (!resolved_type) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Invalid member"); |
|
return -EINVAL; |
|
} |
|
|
|
resolved_member = *member; |
|
resolved_member.type = resolved_type_id; |
|
|
|
return btf_type_ops(resolved_type)->check_member(env, struct_type, |
|
&resolved_member, |
|
resolved_type); |
|
} |
|
|
|
static int btf_modifier_check_kflag_member(struct btf_verifier_env *env, |
|
const struct btf_type *struct_type, |
|
const struct btf_member *member, |
|
const struct btf_type *member_type) |
|
{ |
|
const struct btf_type *resolved_type; |
|
u32 resolved_type_id = member->type; |
|
struct btf_member resolved_member; |
|
struct btf *btf = env->btf; |
|
|
|
resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); |
|
if (!resolved_type) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Invalid member"); |
|
return -EINVAL; |
|
} |
|
|
|
resolved_member = *member; |
|
resolved_member.type = resolved_type_id; |
|
|
|
return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type, |
|
&resolved_member, |
|
resolved_type); |
|
} |
|
|
|
static int btf_ptr_check_member(struct btf_verifier_env *env, |
|
const struct btf_type *struct_type, |
|
const struct btf_member *member, |
|
const struct btf_type *member_type) |
|
{ |
|
u32 struct_size, struct_bits_off, bytes_offset; |
|
|
|
struct_size = struct_type->size; |
|
struct_bits_off = member->offset; |
|
bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
|
|
|
if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Member is not byte aligned"); |
|
return -EINVAL; |
|
} |
|
|
|
if (struct_size - bytes_offset < sizeof(void *)) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Member exceeds struct_size"); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int btf_ref_type_check_meta(struct btf_verifier_env *env, |
|
const struct btf_type *t, |
|
u32 meta_left) |
|
{ |
|
const char *value; |
|
|
|
if (btf_type_vlen(t)) { |
|
btf_verifier_log_type(env, t, "vlen != 0"); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_kflag(t)) { |
|
btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
|
return -EINVAL; |
|
} |
|
|
|
if (!BTF_TYPE_ID_VALID(t->type)) { |
|
btf_verifier_log_type(env, t, "Invalid type_id"); |
|
return -EINVAL; |
|
} |
|
|
|
/* typedef/type_tag type must have a valid name, and other ref types, |
|
* volatile, const, restrict, should have a null name. |
|
*/ |
|
if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) { |
|
if (!t->name_off || |
|
!btf_name_valid_identifier(env->btf, t->name_off)) { |
|
btf_verifier_log_type(env, t, "Invalid name"); |
|
return -EINVAL; |
|
} |
|
} else if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG) { |
|
value = btf_name_by_offset(env->btf, t->name_off); |
|
if (!value || !value[0]) { |
|
btf_verifier_log_type(env, t, "Invalid name"); |
|
return -EINVAL; |
|
} |
|
} else { |
|
if (t->name_off) { |
|
btf_verifier_log_type(env, t, "Invalid name"); |
|
return -EINVAL; |
|
} |
|
} |
|
|
|
btf_verifier_log_type(env, t, NULL); |
|
|
|
return 0; |
|
} |
|
|
|
static int btf_modifier_resolve(struct btf_verifier_env *env, |
|
const struct resolve_vertex *v) |
|
{ |
|
const struct btf_type *t = v->t; |
|
const struct btf_type *next_type; |
|
u32 next_type_id = t->type; |
|
struct btf *btf = env->btf; |
|
|
|
next_type = btf_type_by_id(btf, next_type_id); |
|
if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
|
btf_verifier_log_type(env, v->t, "Invalid type_id"); |
|
return -EINVAL; |
|
} |
|
|
|
if (!env_type_is_resolve_sink(env, next_type) && |
|
!env_type_is_resolved(env, next_type_id)) |
|
return env_stack_push(env, next_type, next_type_id); |
|
|
|
/* Figure out the resolved next_type_id with size. |
|
* They will be stored in the current modifier's |
|
* resolved_ids and resolved_sizes such that it can |
|
* save us a few type-following when we use it later (e.g. in |
|
* pretty print). |
|
*/ |
|
if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
|
if (env_type_is_resolved(env, next_type_id)) |
|
next_type = btf_type_id_resolve(btf, &next_type_id); |
|
|
|
/* "typedef void new_void", "const void"...etc */ |
|
if (!btf_type_is_void(next_type) && |
|
!btf_type_is_fwd(next_type) && |
|
!btf_type_is_func_proto(next_type)) { |
|
btf_verifier_log_type(env, v->t, "Invalid type_id"); |
|
return -EINVAL; |
|
} |
|
} |
|
|
|
env_stack_pop_resolved(env, next_type_id, 0); |
|
|
|
return 0; |
|
} |
|
|
|
static int btf_var_resolve(struct btf_verifier_env *env, |
|
const struct resolve_vertex *v) |
|
{ |
|
const struct btf_type *next_type; |
|
const struct btf_type *t = v->t; |
|
u32 next_type_id = t->type; |
|
struct btf *btf = env->btf; |
|
|
|
next_type = btf_type_by_id(btf, next_type_id); |
|
if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
|
btf_verifier_log_type(env, v->t, "Invalid type_id"); |
|
return -EINVAL; |
|
} |
|
|
|
if (!env_type_is_resolve_sink(env, next_type) && |
|
!env_type_is_resolved(env, next_type_id)) |
|
return env_stack_push(env, next_type, next_type_id); |
|
|
|
if (btf_type_is_modifier(next_type)) { |
|
const struct btf_type *resolved_type; |
|
u32 resolved_type_id; |
|
|
|
resolved_type_id = next_type_id; |
|
resolved_type = btf_type_id_resolve(btf, &resolved_type_id); |
|
|
|
if (btf_type_is_ptr(resolved_type) && |
|
!env_type_is_resolve_sink(env, resolved_type) && |
|
!env_type_is_resolved(env, resolved_type_id)) |
|
return env_stack_push(env, resolved_type, |
|
resolved_type_id); |
|
} |
|
|
|
/* We must resolve to something concrete at this point, no |
|
* forward types or similar that would resolve to size of |
|
* zero is allowed. |
|
*/ |
|
if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
|
btf_verifier_log_type(env, v->t, "Invalid type_id"); |
|
return -EINVAL; |
|
} |
|
|
|
env_stack_pop_resolved(env, next_type_id, 0); |
|
|
|
return 0; |
|
} |
|
|
|
static int btf_ptr_resolve(struct btf_verifier_env *env, |
|
const struct resolve_vertex *v) |
|
{ |
|
const struct btf_type *next_type; |
|
const struct btf_type *t = v->t; |
|
u32 next_type_id = t->type; |
|
struct btf *btf = env->btf; |
|
|
|
next_type = btf_type_by_id(btf, next_type_id); |
|
if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
|
btf_verifier_log_type(env, v->t, "Invalid type_id"); |
|
return -EINVAL; |
|
} |
|
|
|
if (!env_type_is_resolve_sink(env, next_type) && |
|
!env_type_is_resolved(env, next_type_id)) |
|
return env_stack_push(env, next_type, next_type_id); |
|
|
|
/* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY, |
|
* the modifier may have stopped resolving when it was resolved |
|
* to a ptr (last-resolved-ptr). |
|
* |
|
* We now need to continue from the last-resolved-ptr to |
|
* ensure the last-resolved-ptr will not referring back to |
|
* the current ptr (t). |
|
*/ |
|
if (btf_type_is_modifier(next_type)) { |
|
const struct btf_type *resolved_type; |
|
u32 resolved_type_id; |
|
|
|
resolved_type_id = next_type_id; |
|
resolved_type = btf_type_id_resolve(btf, &resolved_type_id); |
|
|
|
if (btf_type_is_ptr(resolved_type) && |
|
!env_type_is_resolve_sink(env, resolved_type) && |
|
!env_type_is_resolved(env, resolved_type_id)) |
|
return env_stack_push(env, resolved_type, |
|
resolved_type_id); |
|
} |
|
|
|
if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
|
if (env_type_is_resolved(env, next_type_id)) |
|
next_type = btf_type_id_resolve(btf, &next_type_id); |
|
|
|
if (!btf_type_is_void(next_type) && |
|
!btf_type_is_fwd(next_type) && |
|
!btf_type_is_func_proto(next_type)) { |
|
btf_verifier_log_type(env, v->t, "Invalid type_id"); |
|
return -EINVAL; |
|
} |
|
} |
|
|
|
env_stack_pop_resolved(env, next_type_id, 0); |
|
|
|
return 0; |
|
} |
|
|
|
static void btf_modifier_show(const struct btf *btf, |
|
const struct btf_type *t, |
|
u32 type_id, void *data, |
|
u8 bits_offset, struct btf_show *show) |
|
{ |
|
if (btf->resolved_ids) |
|
t = btf_type_id_resolve(btf, &type_id); |
|
else |
|
t = btf_type_skip_modifiers(btf, type_id, NULL); |
|
|
|
btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
|
} |
|
|
|
static void btf_var_show(const struct btf *btf, const struct btf_type *t, |
|
u32 type_id, void *data, u8 bits_offset, |
|
struct btf_show *show) |
|
{ |
|
t = btf_type_id_resolve(btf, &type_id); |
|
|
|
btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
|
} |
|
|
|
static void btf_ptr_show(const struct btf *btf, const struct btf_type *t, |
|
u32 type_id, void *data, u8 bits_offset, |
|
struct btf_show *show) |
|
{ |
|
void *safe_data; |
|
|
|
safe_data = btf_show_start_type(show, t, type_id, data); |
|
if (!safe_data) |
|
return; |
|
|
|
/* It is a hashed value unless BTF_SHOW_PTR_RAW is specified */ |
|
if (show->flags & BTF_SHOW_PTR_RAW) |
|
btf_show_type_value(show, "0x%px", *(void **)safe_data); |
|
else |
|
btf_show_type_value(show, "0x%p", *(void **)safe_data); |
|
btf_show_end_type(show); |
|
} |
|
|
|
static void btf_ref_type_log(struct btf_verifier_env *env, |
|
const struct btf_type *t) |
|
{ |
|
btf_verifier_log(env, "type_id=%u", t->type); |
|
} |
|
|
|
static struct btf_kind_operations modifier_ops = { |
|
.check_meta = btf_ref_type_check_meta, |
|
.resolve = btf_modifier_resolve, |
|
.check_member = btf_modifier_check_member, |
|
.check_kflag_member = btf_modifier_check_kflag_member, |
|
.log_details = btf_ref_type_log, |
|
.show = btf_modifier_show, |
|
}; |
|
|
|
static struct btf_kind_operations ptr_ops = { |
|
.check_meta = btf_ref_type_check_meta, |
|
.resolve = btf_ptr_resolve, |
|
.check_member = btf_ptr_check_member, |
|
.check_kflag_member = btf_generic_check_kflag_member, |
|
.log_details = btf_ref_type_log, |
|
.show = btf_ptr_show, |
|
}; |
|
|
|
static s32 btf_fwd_check_meta(struct btf_verifier_env *env, |
|
const struct btf_type *t, |
|
u32 meta_left) |
|
{ |
|
if (btf_type_vlen(t)) { |
|
btf_verifier_log_type(env, t, "vlen != 0"); |
|
return -EINVAL; |
|
} |
|
|
|
if (t->type) { |
|
btf_verifier_log_type(env, t, "type != 0"); |
|
return -EINVAL; |
|
} |
|
|
|
/* fwd type must have a valid name */ |
|
if (!t->name_off || |
|
!btf_name_valid_identifier(env->btf, t->name_off)) { |
|
btf_verifier_log_type(env, t, "Invalid name"); |
|
return -EINVAL; |
|
} |
|
|
|
btf_verifier_log_type(env, t, NULL); |
|
|
|
return 0; |
|
} |
|
|
|
static void btf_fwd_type_log(struct btf_verifier_env *env, |
|
const struct btf_type *t) |
|
{ |
|
btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct"); |
|
} |
|
|
|
static struct btf_kind_operations fwd_ops = { |
|
.check_meta = btf_fwd_check_meta, |
|
.resolve = btf_df_resolve, |
|
.check_member = btf_df_check_member, |
|
.check_kflag_member = btf_df_check_kflag_member, |
|
.log_details = btf_fwd_type_log, |
|
.show = btf_df_show, |
|
}; |
|
|
|
static int btf_array_check_member(struct btf_verifier_env *env, |
|
const struct btf_type *struct_type, |
|
const struct btf_member *member, |
|
const struct btf_type *member_type) |
|
{ |
|
u32 struct_bits_off = member->offset; |
|
u32 struct_size, bytes_offset; |
|
u32 array_type_id, array_size; |
|
struct btf *btf = env->btf; |
|
|
|
if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Member is not byte aligned"); |
|
return -EINVAL; |
|
} |
|
|
|
array_type_id = member->type; |
|
btf_type_id_size(btf, &array_type_id, &array_size); |
|
struct_size = struct_type->size; |
|
bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
|
if (struct_size - bytes_offset < array_size) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Member exceeds struct_size"); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static s32 btf_array_check_meta(struct btf_verifier_env *env, |
|
const struct btf_type *t, |
|
u32 meta_left) |
|
{ |
|
const struct btf_array *array = btf_type_array(t); |
|
u32 meta_needed = sizeof(*array); |
|
|
|
if (meta_left < meta_needed) { |
|
btf_verifier_log_basic(env, t, |
|
"meta_left:%u meta_needed:%u", |
|
meta_left, meta_needed); |
|
return -EINVAL; |
|
} |
|
|
|
/* array type should not have a name */ |
|
if (t->name_off) { |
|
btf_verifier_log_type(env, t, "Invalid name"); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_vlen(t)) { |
|
btf_verifier_log_type(env, t, "vlen != 0"); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_kflag(t)) { |
|
btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
|
return -EINVAL; |
|
} |
|
|
|
if (t->size) { |
|
btf_verifier_log_type(env, t, "size != 0"); |
|
return -EINVAL; |
|
} |
|
|
|
/* Array elem type and index type cannot be in type void, |
|
* so !array->type and !array->index_type are not allowed. |
|
*/ |
|
if (!array->type || !BTF_TYPE_ID_VALID(array->type)) { |
|
btf_verifier_log_type(env, t, "Invalid elem"); |
|
return -EINVAL; |
|
} |
|
|
|
if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) { |
|
btf_verifier_log_type(env, t, "Invalid index"); |
|
return -EINVAL; |
|
} |
|
|
|
btf_verifier_log_type(env, t, NULL); |
|
|
|
return meta_needed; |
|
} |
|
|
|
static int btf_array_resolve(struct btf_verifier_env *env, |
|
const struct resolve_vertex *v) |
|
{ |
|
const struct btf_array *array = btf_type_array(v->t); |
|
const struct btf_type *elem_type, *index_type; |
|
u32 elem_type_id, index_type_id; |
|
struct btf *btf = env->btf; |
|
u32 elem_size; |
|
|
|
/* Check array->index_type */ |
|
index_type_id = array->index_type; |
|
index_type = btf_type_by_id(btf, index_type_id); |
|
if (btf_type_nosize_or_null(index_type) || |
|
btf_type_is_resolve_source_only(index_type)) { |
|
btf_verifier_log_type(env, v->t, "Invalid index"); |
|
return -EINVAL; |
|
} |
|
|
|
if (!env_type_is_resolve_sink(env, index_type) && |
|
!env_type_is_resolved(env, index_type_id)) |
|
return env_stack_push(env, index_type, index_type_id); |
|
|
|
index_type = btf_type_id_size(btf, &index_type_id, NULL); |
|
if (!index_type || !btf_type_is_int(index_type) || |
|
!btf_type_int_is_regular(index_type)) { |
|
btf_verifier_log_type(env, v->t, "Invalid index"); |
|
return -EINVAL; |
|
} |
|
|
|
/* Check array->type */ |
|
elem_type_id = array->type; |
|
elem_type = btf_type_by_id(btf, elem_type_id); |
|
if (btf_type_nosize_or_null(elem_type) || |
|
btf_type_is_resolve_source_only(elem_type)) { |
|
btf_verifier_log_type(env, v->t, |
|
"Invalid elem"); |
|
return -EINVAL; |
|
} |
|
|
|
if (!env_type_is_resolve_sink(env, elem_type) && |
|
!env_type_is_resolved(env, elem_type_id)) |
|
return env_stack_push(env, elem_type, elem_type_id); |
|
|
|
elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); |
|
if (!elem_type) { |
|
btf_verifier_log_type(env, v->t, "Invalid elem"); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) { |
|
btf_verifier_log_type(env, v->t, "Invalid array of int"); |
|
return -EINVAL; |
|
} |
|
|
|
if (array->nelems && elem_size > U32_MAX / array->nelems) { |
|
btf_verifier_log_type(env, v->t, |
|
"Array size overflows U32_MAX"); |
|
return -EINVAL; |
|
} |
|
|
|
env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems); |
|
|
|
return 0; |
|
} |
|
|
|
static void btf_array_log(struct btf_verifier_env *env, |
|
const struct btf_type *t) |
|
{ |
|
const struct btf_array *array = btf_type_array(t); |
|
|
|
btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u", |
|
array->type, array->index_type, array->nelems); |
|
} |
|
|
|
static void __btf_array_show(const struct btf *btf, const struct btf_type *t, |
|
u32 type_id, void *data, u8 bits_offset, |
|
struct btf_show *show) |
|
{ |
|
const struct btf_array *array = btf_type_array(t); |
|
const struct btf_kind_operations *elem_ops; |
|
const struct btf_type *elem_type; |
|
u32 i, elem_size = 0, elem_type_id; |
|
u16 encoding = 0; |
|
|
|
elem_type_id = array->type; |
|
elem_type = btf_type_skip_modifiers(btf, elem_type_id, NULL); |
|
if (elem_type && btf_type_has_size(elem_type)) |
|
elem_size = elem_type->size; |
|
|
|
if (elem_type && btf_type_is_int(elem_type)) { |
|
u32 int_type = btf_type_int(elem_type); |
|
|
|
encoding = BTF_INT_ENCODING(int_type); |
|
|
|
/* |
|
* BTF_INT_CHAR encoding never seems to be set for |
|
* char arrays, so if size is 1 and element is |
|
* printable as a char, we'll do that. |
|
*/ |
|
if (elem_size == 1) |
|
encoding = BTF_INT_CHAR; |
|
} |
|
|
|
if (!btf_show_start_array_type(show, t, type_id, encoding, data)) |
|
return; |
|
|
|
if (!elem_type) |
|
goto out; |
|
elem_ops = btf_type_ops(elem_type); |
|
|
|
for (i = 0; i < array->nelems; i++) { |
|
|
|
btf_show_start_array_member(show); |
|
|
|
elem_ops->show(btf, elem_type, elem_type_id, data, |
|
bits_offset, show); |
|
data += elem_size; |
|
|
|
btf_show_end_array_member(show); |
|
|
|
if (show->state.array_terminated) |
|
break; |
|
} |
|
out: |
|
btf_show_end_array_type(show); |
|
} |
|
|
|
static void btf_array_show(const struct btf *btf, const struct btf_type *t, |
|
u32 type_id, void *data, u8 bits_offset, |
|
struct btf_show *show) |
|
{ |
|
const struct btf_member *m = show->state.member; |
|
|
|
/* |
|
* First check if any members would be shown (are non-zero). |
|
* See comments above "struct btf_show" definition for more |
|
* details on how this works at a high-level. |
|
*/ |
|
if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { |
|
if (!show->state.depth_check) { |
|
show->state.depth_check = show->state.depth + 1; |
|
show->state.depth_to_show = 0; |
|
} |
|
__btf_array_show(btf, t, type_id, data, bits_offset, show); |
|
show->state.member = m; |
|
|
|
if (show->state.depth_check != show->state.depth + 1) |
|
return; |
|
show->state.depth_check = 0; |
|
|
|
if (show->state.depth_to_show <= show->state.depth) |
|
return; |
|
/* |
|
* Reaching here indicates we have recursed and found |
|
* non-zero array member(s). |
|
*/ |
|
} |
|
__btf_array_show(btf, t, type_id, data, bits_offset, show); |
|
} |
|
|
|
static struct btf_kind_operations array_ops = { |
|
.check_meta = btf_array_check_meta, |
|
.resolve = btf_array_resolve, |
|
.check_member = btf_array_check_member, |
|
.check_kflag_member = btf_generic_check_kflag_member, |
|
.log_details = btf_array_log, |
|
.show = btf_array_show, |
|
}; |
|
|
|
static int btf_struct_check_member(struct btf_verifier_env *env, |
|
const struct btf_type *struct_type, |
|
const struct btf_member *member, |
|
const struct btf_type *member_type) |
|
{ |
|
u32 struct_bits_off = member->offset; |
|
u32 struct_size, bytes_offset; |
|
|
|
if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Member is not byte aligned"); |
|
return -EINVAL; |
|
} |
|
|
|
struct_size = struct_type->size; |
|
bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
|
if (struct_size - bytes_offset < member_type->size) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Member exceeds struct_size"); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static s32 btf_struct_check_meta(struct btf_verifier_env *env, |
|
const struct btf_type *t, |
|
u32 meta_left) |
|
{ |
|
bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION; |
|
const struct btf_member *member; |
|
u32 meta_needed, last_offset; |
|
struct btf *btf = env->btf; |
|
u32 struct_size = t->size; |
|
u32 offset; |
|
u16 i; |
|
|
|
meta_needed = btf_type_vlen(t) * sizeof(*member); |
|
if (meta_left < meta_needed) { |
|
btf_verifier_log_basic(env, t, |
|
"meta_left:%u meta_needed:%u", |
|
meta_left, meta_needed); |
|
return -EINVAL; |
|
} |
|
|
|
/* struct type either no name or a valid one */ |
|
if (t->name_off && |
|
!btf_name_valid_identifier(env->btf, t->name_off)) { |
|
btf_verifier_log_type(env, t, "Invalid name"); |
|
return -EINVAL; |
|
} |
|
|
|
btf_verifier_log_type(env, t, NULL); |
|
|
|
last_offset = 0; |
|
for_each_member(i, t, member) { |
|
if (!btf_name_offset_valid(btf, member->name_off)) { |
|
btf_verifier_log_member(env, t, member, |
|
"Invalid member name_offset:%u", |
|
member->name_off); |
|
return -EINVAL; |
|
} |
|
|
|
/* struct member either no name or a valid one */ |
|
if (member->name_off && |
|
!btf_name_valid_identifier(btf, member->name_off)) { |
|
btf_verifier_log_member(env, t, member, "Invalid name"); |
|
return -EINVAL; |
|
} |
|
/* A member cannot be in type void */ |
|
if (!member->type || !BTF_TYPE_ID_VALID(member->type)) { |
|
btf_verifier_log_member(env, t, member, |
|
"Invalid type_id"); |
|
return -EINVAL; |
|
} |
|
|
|
offset = __btf_member_bit_offset(t, member); |
|
if (is_union && offset) { |
|
btf_verifier_log_member(env, t, member, |
|
"Invalid member bits_offset"); |
|
return -EINVAL; |
|
} |
|
|
|
/* |
|
* ">" instead of ">=" because the last member could be |
|
* "char a[0];" |
|
*/ |
|
if (last_offset > offset) { |
|
btf_verifier_log_member(env, t, member, |
|
"Invalid member bits_offset"); |
|
return -EINVAL; |
|
} |
|
|
|
if (BITS_ROUNDUP_BYTES(offset) > struct_size) { |
|
btf_verifier_log_member(env, t, member, |
|
"Member bits_offset exceeds its struct size"); |
|
return -EINVAL; |
|
} |
|
|
|
btf_verifier_log_member(env, t, member, NULL); |
|
last_offset = offset; |
|
} |
|
|
|
return meta_needed; |
|
} |
|
|
|
static int btf_struct_resolve(struct btf_verifier_env *env, |
|
const struct resolve_vertex *v) |
|
{ |
|
const struct btf_member *member; |
|
int err; |
|
u16 i; |
|
|
|
/* Before continue resolving the next_member, |
|
* ensure the last member is indeed resolved to a |
|
* type with size info. |
|
*/ |
|
if (v->next_member) { |
|
const struct btf_type *last_member_type; |
|
const struct btf_member *last_member; |
|
u16 last_member_type_id; |
|
|
|
last_member = btf_type_member(v->t) + v->next_member - 1; |
|
last_member_type_id = last_member->type; |
|
if (WARN_ON_ONCE(!env_type_is_resolved(env, |
|
last_member_type_id))) |
|
return -EINVAL; |
|
|
|
last_member_type = btf_type_by_id(env->btf, |
|
last_member_type_id); |
|
if (btf_type_kflag(v->t)) |
|
err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t, |
|
last_member, |
|
last_member_type); |
|
else |
|
err = btf_type_ops(last_member_type)->check_member(env, v->t, |
|
last_member, |
|
last_member_type); |
|
if (err) |
|
return err; |
|
} |
|
|
|
for_each_member_from(i, v->next_member, v->t, member) { |
|
u32 member_type_id = member->type; |
|
const struct btf_type *member_type = btf_type_by_id(env->btf, |
|
member_type_id); |
|
|
|
if (btf_type_nosize_or_null(member_type) || |
|
btf_type_is_resolve_source_only(member_type)) { |
|
btf_verifier_log_member(env, v->t, member, |
|
"Invalid member"); |
|
return -EINVAL; |
|
} |
|
|
|
if (!env_type_is_resolve_sink(env, member_type) && |
|
!env_type_is_resolved(env, member_type_id)) { |
|
env_stack_set_next_member(env, i + 1); |
|
return env_stack_push(env, member_type, member_type_id); |
|
} |
|
|
|
if (btf_type_kflag(v->t)) |
|
err = btf_type_ops(member_type)->check_kflag_member(env, v->t, |
|
member, |
|
member_type); |
|
else |
|
err = btf_type_ops(member_type)->check_member(env, v->t, |
|
member, |
|
member_type); |
|
if (err) |
|
return err; |
|
} |
|
|
|
env_stack_pop_resolved(env, 0, 0); |
|
|
|
return 0; |
|
} |
|
|
|
static void btf_struct_log(struct btf_verifier_env *env, |
|
const struct btf_type *t) |
|
{ |
|
btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); |
|
} |
|
|
|
static int btf_find_struct_field(const struct btf *btf, const struct btf_type *t, |
|
const char *name, int sz, int align) |
|
{ |
|
const struct btf_member *member; |
|
u32 i, off = -ENOENT; |
|
|
|
for_each_member(i, t, member) { |
|
const struct btf_type *member_type = btf_type_by_id(btf, |
|
member->type); |
|
if (!__btf_type_is_struct(member_type)) |
|
continue; |
|
if (member_type->size != sz) |
|
continue; |
|
if (strcmp(__btf_name_by_offset(btf, member_type->name_off), name)) |
|
continue; |
|
if (off != -ENOENT) |
|
/* only one such field is allowed */ |
|
return -E2BIG; |
|
off = __btf_member_bit_offset(t, member); |
|
if (off % 8) |
|
/* valid C code cannot generate such BTF */ |
|
return -EINVAL; |
|
off /= 8; |
|
if (off % align) |
|
return -EINVAL; |
|
} |
|
return off; |
|
} |
|
|
|
static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t, |
|
const char *name, int sz, int align) |
|
{ |
|
const struct btf_var_secinfo *vsi; |
|
u32 i, off = -ENOENT; |
|
|
|
for_each_vsi(i, t, vsi) { |
|
const struct btf_type *var = btf_type_by_id(btf, vsi->type); |
|
const struct btf_type *var_type = btf_type_by_id(btf, var->type); |
|
|
|
if (!__btf_type_is_struct(var_type)) |
|
continue; |
|
if (var_type->size != sz) |
|
continue; |
|
if (vsi->size != sz) |
|
continue; |
|
if (strcmp(__btf_name_by_offset(btf, var_type->name_off), name)) |
|
continue; |
|
if (off != -ENOENT) |
|
/* only one such field is allowed */ |
|
return -E2BIG; |
|
off = vsi->offset; |
|
if (off % align) |
|
return -EINVAL; |
|
} |
|
return off; |
|
} |
|
|
|
static int btf_find_field(const struct btf *btf, const struct btf_type *t, |
|
const char *name, int sz, int align) |
|
{ |
|
|
|
if (__btf_type_is_struct(t)) |
|
return btf_find_struct_field(btf, t, name, sz, align); |
|
else if (btf_type_is_datasec(t)) |
|
return btf_find_datasec_var(btf, t, name, sz, align); |
|
return -EINVAL; |
|
} |
|
|
|
/* find 'struct bpf_spin_lock' in map value. |
|
* return >= 0 offset if found |
|
* and < 0 in case of error |
|
*/ |
|
int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t) |
|
{ |
|
return btf_find_field(btf, t, "bpf_spin_lock", |
|
sizeof(struct bpf_spin_lock), |
|
__alignof__(struct bpf_spin_lock)); |
|
} |
|
|
|
int btf_find_timer(const struct btf *btf, const struct btf_type *t) |
|
{ |
|
return btf_find_field(btf, t, "bpf_timer", |
|
sizeof(struct bpf_timer), |
|
__alignof__(struct bpf_timer)); |
|
} |
|
|
|
static void __btf_struct_show(const struct btf *btf, const struct btf_type *t, |
|
u32 type_id, void *data, u8 bits_offset, |
|
struct btf_show *show) |
|
{ |
|
const struct btf_member *member; |
|
void *safe_data; |
|
u32 i; |
|
|
|
safe_data = btf_show_start_struct_type(show, t, type_id, data); |
|
if (!safe_data) |
|
return; |
|
|
|
for_each_member(i, t, member) { |
|
const struct btf_type *member_type = btf_type_by_id(btf, |
|
member->type); |
|
const struct btf_kind_operations *ops; |
|
u32 member_offset, bitfield_size; |
|
u32 bytes_offset; |
|
u8 bits8_offset; |
|
|
|
btf_show_start_member(show, member); |
|
|
|
member_offset = __btf_member_bit_offset(t, member); |
|
bitfield_size = __btf_member_bitfield_size(t, member); |
|
bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset); |
|
bits8_offset = BITS_PER_BYTE_MASKED(member_offset); |
|
if (bitfield_size) { |
|
safe_data = btf_show_start_type(show, member_type, |
|
member->type, |
|
data + bytes_offset); |
|
if (safe_data) |
|
btf_bitfield_show(safe_data, |
|
bits8_offset, |
|
bitfield_size, show); |
|
btf_show_end_type(show); |
|
} else { |
|
ops = btf_type_ops(member_type); |
|
ops->show(btf, member_type, member->type, |
|
data + bytes_offset, bits8_offset, show); |
|
} |
|
|
|
btf_show_end_member(show); |
|
} |
|
|
|
btf_show_end_struct_type(show); |
|
} |
|
|
|
static void btf_struct_show(const struct btf *btf, const struct btf_type *t, |
|
u32 type_id, void *data, u8 bits_offset, |
|
struct btf_show *show) |
|
{ |
|
const struct btf_member *m = show->state.member; |
|
|
|
/* |
|
* First check if any members would be shown (are non-zero). |
|
* See comments above "struct btf_show" definition for more |
|
* details on how this works at a high-level. |
|
*/ |
|
if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { |
|
if (!show->state.depth_check) { |
|
show->state.depth_check = show->state.depth + 1; |
|
show->state.depth_to_show = 0; |
|
} |
|
__btf_struct_show(btf, t, type_id, data, bits_offset, show); |
|
/* Restore saved member data here */ |
|
show->state.member = m; |
|
if (show->state.depth_check != show->state.depth + 1) |
|
return; |
|
show->state.depth_check = 0; |
|
|
|
if (show->state.depth_to_show <= show->state.depth) |
|
return; |
|
/* |
|
* Reaching here indicates we have recursed and found |
|
* non-zero child values. |
|
*/ |
|
} |
|
|
|
__btf_struct_show(btf, t, type_id, data, bits_offset, show); |
|
} |
|
|
|
static struct btf_kind_operations struct_ops = { |
|
.check_meta = btf_struct_check_meta, |
|
.resolve = btf_struct_resolve, |
|
.check_member = btf_struct_check_member, |
|
.check_kflag_member = btf_generic_check_kflag_member, |
|
.log_details = btf_struct_log, |
|
.show = btf_struct_show, |
|
}; |
|
|
|
static int btf_enum_check_member(struct btf_verifier_env *env, |
|
const struct btf_type *struct_type, |
|
const struct btf_member *member, |
|
const struct btf_type *member_type) |
|
{ |
|
u32 struct_bits_off = member->offset; |
|
u32 struct_size, bytes_offset; |
|
|
|
if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Member is not byte aligned"); |
|
return -EINVAL; |
|
} |
|
|
|
struct_size = struct_type->size; |
|
bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
|
if (struct_size - bytes_offset < member_type->size) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Member exceeds struct_size"); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int btf_enum_check_kflag_member(struct btf_verifier_env *env, |
|
const struct btf_type *struct_type, |
|
const struct btf_member *member, |
|
const struct btf_type *member_type) |
|
{ |
|
u32 struct_bits_off, nr_bits, bytes_end, struct_size; |
|
u32 int_bitsize = sizeof(int) * BITS_PER_BYTE; |
|
|
|
struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); |
|
nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); |
|
if (!nr_bits) { |
|
if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Member is not byte aligned"); |
|
return -EINVAL; |
|
} |
|
|
|
nr_bits = int_bitsize; |
|
} else if (nr_bits > int_bitsize) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Invalid member bitfield_size"); |
|
return -EINVAL; |
|
} |
|
|
|
struct_size = struct_type->size; |
|
bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits); |
|
if (struct_size < bytes_end) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Member exceeds struct_size"); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static s32 btf_enum_check_meta(struct btf_verifier_env *env, |
|
const struct btf_type *t, |
|
u32 meta_left) |
|
{ |
|
const struct btf_enum *enums = btf_type_enum(t); |
|
struct btf *btf = env->btf; |
|
u16 i, nr_enums; |
|
u32 meta_needed; |
|
|
|
nr_enums = btf_type_vlen(t); |
|
meta_needed = nr_enums * sizeof(*enums); |
|
|
|
if (meta_left < meta_needed) { |
|
btf_verifier_log_basic(env, t, |
|
"meta_left:%u meta_needed:%u", |
|
meta_left, meta_needed); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_kflag(t)) { |
|
btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
|
return -EINVAL; |
|
} |
|
|
|
if (t->size > 8 || !is_power_of_2(t->size)) { |
|
btf_verifier_log_type(env, t, "Unexpected size"); |
|
return -EINVAL; |
|
} |
|
|
|
/* enum type either no name or a valid one */ |
|
if (t->name_off && |
|
!btf_name_valid_identifier(env->btf, t->name_off)) { |
|
btf_verifier_log_type(env, t, "Invalid name"); |
|
return -EINVAL; |
|
} |
|
|
|
btf_verifier_log_type(env, t, NULL); |
|
|
|
for (i = 0; i < nr_enums; i++) { |
|
if (!btf_name_offset_valid(btf, enums[i].name_off)) { |
|
btf_verifier_log(env, "\tInvalid name_offset:%u", |
|
enums[i].name_off); |
|
return -EINVAL; |
|
} |
|
|
|
/* enum member must have a valid name */ |
|
if (!enums[i].name_off || |
|
!btf_name_valid_identifier(btf, enums[i].name_off)) { |
|
btf_verifier_log_type(env, t, "Invalid name"); |
|
return -EINVAL; |
|
} |
|
|
|
if (env->log.level == BPF_LOG_KERNEL) |
|
continue; |
|
btf_verifier_log(env, "\t%s val=%d\n", |
|
__btf_name_by_offset(btf, enums[i].name_off), |
|
enums[i].val); |
|
} |
|
|
|
return meta_needed; |
|
} |
|
|
|
static void btf_enum_log(struct btf_verifier_env *env, |
|
const struct btf_type *t) |
|
{ |
|
btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); |
|
} |
|
|
|
static void btf_enum_show(const struct btf *btf, const struct btf_type *t, |
|
u32 type_id, void *data, u8 bits_offset, |
|
struct btf_show *show) |
|
{ |
|
const struct btf_enum *enums = btf_type_enum(t); |
|
u32 i, nr_enums = btf_type_vlen(t); |
|
void *safe_data; |
|
int v; |
|
|
|
safe_data = btf_show_start_type(show, t, type_id, data); |
|
if (!safe_data) |
|
return; |
|
|
|
v = *(int *)safe_data; |
|
|
|
for (i = 0; i < nr_enums; i++) { |
|
if (v != enums[i].val) |
|
continue; |
|
|
|
btf_show_type_value(show, "%s", |
|
__btf_name_by_offset(btf, |
|
enums[i].name_off)); |
|
|
|
btf_show_end_type(show); |
|
return; |
|
} |
|
|
|
btf_show_type_value(show, "%d", v); |
|
btf_show_end_type(show); |
|
} |
|
|
|
static struct btf_kind_operations enum_ops = { |
|
.check_meta = btf_enum_check_meta, |
|
.resolve = btf_df_resolve, |
|
.check_member = btf_enum_check_member, |
|
.check_kflag_member = btf_enum_check_kflag_member, |
|
.log_details = btf_enum_log, |
|
.show = btf_enum_show, |
|
}; |
|
|
|
static s32 btf_func_proto_check_meta(struct btf_verifier_env *env, |
|
const struct btf_type *t, |
|
u32 meta_left) |
|
{ |
|
u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param); |
|
|
|
if (meta_left < meta_needed) { |
|
btf_verifier_log_basic(env, t, |
|
"meta_left:%u meta_needed:%u", |
|
meta_left, meta_needed); |
|
return -EINVAL; |
|
} |
|
|
|
if (t->name_off) { |
|
btf_verifier_log_type(env, t, "Invalid name"); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_kflag(t)) { |
|
btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
|
return -EINVAL; |
|
} |
|
|
|
btf_verifier_log_type(env, t, NULL); |
|
|
|
return meta_needed; |
|
} |
|
|
|
static void btf_func_proto_log(struct btf_verifier_env *env, |
|
const struct btf_type *t) |
|
{ |
|
const struct btf_param *args = (const struct btf_param *)(t + 1); |
|
u16 nr_args = btf_type_vlen(t), i; |
|
|
|
btf_verifier_log(env, "return=%u args=(", t->type); |
|
if (!nr_args) { |
|
btf_verifier_log(env, "void"); |
|
goto done; |
|
} |
|
|
|
if (nr_args == 1 && !args[0].type) { |
|
/* Only one vararg */ |
|
btf_verifier_log(env, "vararg"); |
|
goto done; |
|
} |
|
|
|
btf_verifier_log(env, "%u %s", args[0].type, |
|
__btf_name_by_offset(env->btf, |
|
args[0].name_off)); |
|
for (i = 1; i < nr_args - 1; i++) |
|
btf_verifier_log(env, ", %u %s", args[i].type, |
|
__btf_name_by_offset(env->btf, |
|
args[i].name_off)); |
|
|
|
if (nr_args > 1) { |
|
const struct btf_param *last_arg = &args[nr_args - 1]; |
|
|
|
if (last_arg->type) |
|
btf_verifier_log(env, ", %u %s", last_arg->type, |
|
__btf_name_by_offset(env->btf, |
|
last_arg->name_off)); |
|
else |
|
btf_verifier_log(env, ", vararg"); |
|
} |
|
|
|
done: |
|
btf_verifier_log(env, ")"); |
|
} |
|
|
|
static struct btf_kind_operations func_proto_ops = { |
|
.check_meta = btf_func_proto_check_meta, |
|
.resolve = btf_df_resolve, |
|
/* |
|
* BTF_KIND_FUNC_PROTO cannot be directly referred by |
|
* a struct's member. |
|
* |
|
* It should be a function pointer instead. |
|
* (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO) |
|
* |
|
* Hence, there is no btf_func_check_member(). |
|
*/ |
|
.check_member = btf_df_check_member, |
|
.check_kflag_member = btf_df_check_kflag_member, |
|
.log_details = btf_func_proto_log, |
|
.show = btf_df_show, |
|
}; |
|
|
|
static s32 btf_func_check_meta(struct btf_verifier_env *env, |
|
const struct btf_type *t, |
|
u32 meta_left) |
|
{ |
|
if (!t->name_off || |
|
!btf_name_valid_identifier(env->btf, t->name_off)) { |
|
btf_verifier_log_type(env, t, "Invalid name"); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) { |
|
btf_verifier_log_type(env, t, "Invalid func linkage"); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_kflag(t)) { |
|
btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
|
return -EINVAL; |
|
} |
|
|
|
btf_verifier_log_type(env, t, NULL); |
|
|
|
return 0; |
|
} |
|
|
|
static int btf_func_resolve(struct btf_verifier_env *env, |
|
const struct resolve_vertex *v) |
|
{ |
|
const struct btf_type *t = v->t; |
|
u32 next_type_id = t->type; |
|
int err; |
|
|
|
err = btf_func_check(env, t); |
|
if (err) |
|
return err; |
|
|
|
env_stack_pop_resolved(env, next_type_id, 0); |
|
return 0; |
|
} |
|
|
|
static struct btf_kind_operations func_ops = { |
|
.check_meta = btf_func_check_meta, |
|
.resolve = btf_func_resolve, |
|
.check_member = btf_df_check_member, |
|
.check_kflag_member = btf_df_check_kflag_member, |
|
.log_details = btf_ref_type_log, |
|
.show = btf_df_show, |
|
}; |
|
|
|
static s32 btf_var_check_meta(struct btf_verifier_env *env, |
|
const struct btf_type *t, |
|
u32 meta_left) |
|
{ |
|
const struct btf_var *var; |
|
u32 meta_needed = sizeof(*var); |
|
|
|
if (meta_left < meta_needed) { |
|
btf_verifier_log_basic(env, t, |
|
"meta_left:%u meta_needed:%u", |
|
meta_left, meta_needed); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_vlen(t)) { |
|
btf_verifier_log_type(env, t, "vlen != 0"); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_kflag(t)) { |
|
btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
|
return -EINVAL; |
|
} |
|
|
|
if (!t->name_off || |
|
!__btf_name_valid(env->btf, t->name_off, true)) { |
|
btf_verifier_log_type(env, t, "Invalid name"); |
|
return -EINVAL; |
|
} |
|
|
|
/* A var cannot be in type void */ |
|
if (!t->type || !BTF_TYPE_ID_VALID(t->type)) { |
|
btf_verifier_log_type(env, t, "Invalid type_id"); |
|
return -EINVAL; |
|
} |
|
|
|
var = btf_type_var(t); |
|
if (var->linkage != BTF_VAR_STATIC && |
|
var->linkage != BTF_VAR_GLOBAL_ALLOCATED) { |
|
btf_verifier_log_type(env, t, "Linkage not supported"); |
|
return -EINVAL; |
|
} |
|
|
|
btf_verifier_log_type(env, t, NULL); |
|
|
|
return meta_needed; |
|
} |
|
|
|
static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t) |
|
{ |
|
const struct btf_var *var = btf_type_var(t); |
|
|
|
btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage); |
|
} |
|
|
|
static const struct btf_kind_operations var_ops = { |
|
.check_meta = btf_var_check_meta, |
|
.resolve = btf_var_resolve, |
|
.check_member = btf_df_check_member, |
|
.check_kflag_member = btf_df_check_kflag_member, |
|
.log_details = btf_var_log, |
|
.show = btf_var_show, |
|
}; |
|
|
|
static s32 btf_datasec_check_meta(struct btf_verifier_env *env, |
|
const struct btf_type *t, |
|
u32 meta_left) |
|
{ |
|
const struct btf_var_secinfo *vsi; |
|
u64 last_vsi_end_off = 0, sum = 0; |
|
u32 i, meta_needed; |
|
|
|
meta_needed = btf_type_vlen(t) * sizeof(*vsi); |
|
if (meta_left < meta_needed) { |
|
btf_verifier_log_basic(env, t, |
|
"meta_left:%u meta_needed:%u", |
|
meta_left, meta_needed); |
|
return -EINVAL; |
|
} |
|
|
|
if (!t->size) { |
|
btf_verifier_log_type(env, t, "size == 0"); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_kflag(t)) { |
|
btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
|
return -EINVAL; |
|
} |
|
|
|
if (!t->name_off || |
|
!btf_name_valid_section(env->btf, t->name_off)) { |
|
btf_verifier_log_type(env, t, "Invalid name"); |
|
return -EINVAL; |
|
} |
|
|
|
btf_verifier_log_type(env, t, NULL); |
|
|
|
for_each_vsi(i, t, vsi) { |
|
/* A var cannot be in type void */ |
|
if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) { |
|
btf_verifier_log_vsi(env, t, vsi, |
|
"Invalid type_id"); |
|
return -EINVAL; |
|
} |
|
|
|
if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) { |
|
btf_verifier_log_vsi(env, t, vsi, |
|
"Invalid offset"); |
|
return -EINVAL; |
|
} |
|
|
|
if (!vsi->size || vsi->size > t->size) { |
|
btf_verifier_log_vsi(env, t, vsi, |
|
"Invalid size"); |
|
return -EINVAL; |
|
} |
|
|
|
last_vsi_end_off = vsi->offset + vsi->size; |
|
if (last_vsi_end_off > t->size) { |
|
btf_verifier_log_vsi(env, t, vsi, |
|
"Invalid offset+size"); |
|
return -EINVAL; |
|
} |
|
|
|
btf_verifier_log_vsi(env, t, vsi, NULL); |
|
sum += vsi->size; |
|
} |
|
|
|
if (t->size < sum) { |
|
btf_verifier_log_type(env, t, "Invalid btf_info size"); |
|
return -EINVAL; |
|
} |
|
|
|
return meta_needed; |
|
} |
|
|
|
static int btf_datasec_resolve(struct btf_verifier_env *env, |
|
const struct resolve_vertex *v) |
|
{ |
|
const struct btf_var_secinfo *vsi; |
|
struct btf *btf = env->btf; |
|
u16 i; |
|
|
|
for_each_vsi_from(i, v->next_member, v->t, vsi) { |
|
u32 var_type_id = vsi->type, type_id, type_size = 0; |
|
const struct btf_type *var_type = btf_type_by_id(env->btf, |
|
var_type_id); |
|
if (!var_type || !btf_type_is_var(var_type)) { |
|
btf_verifier_log_vsi(env, v->t, vsi, |
|
"Not a VAR kind member"); |
|
return -EINVAL; |
|
} |
|
|
|
if (!env_type_is_resolve_sink(env, var_type) && |
|
!env_type_is_resolved(env, var_type_id)) { |
|
env_stack_set_next_member(env, i + 1); |
|
return env_stack_push(env, var_type, var_type_id); |
|
} |
|
|
|
type_id = var_type->type; |
|
if (!btf_type_id_size(btf, &type_id, &type_size)) { |
|
btf_verifier_log_vsi(env, v->t, vsi, "Invalid type"); |
|
return -EINVAL; |
|
} |
|
|
|
if (vsi->size < type_size) { |
|
btf_verifier_log_vsi(env, v->t, vsi, "Invalid size"); |
|
return -EINVAL; |
|
} |
|
} |
|
|
|
env_stack_pop_resolved(env, 0, 0); |
|
return 0; |
|
} |
|
|
|
static void btf_datasec_log(struct btf_verifier_env *env, |
|
const struct btf_type *t) |
|
{ |
|
btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); |
|
} |
|
|
|
static void btf_datasec_show(const struct btf *btf, |
|
const struct btf_type *t, u32 type_id, |
|
void *data, u8 bits_offset, |
|
struct btf_show *show) |
|
{ |
|
const struct btf_var_secinfo *vsi; |
|
const struct btf_type *var; |
|
u32 i; |
|
|
|
if (!btf_show_start_type(show, t, type_id, data)) |
|
return; |
|
|
|
btf_show_type_value(show, "section (\"%s\") = {", |
|
__btf_name_by_offset(btf, t->name_off)); |
|
for_each_vsi(i, t, vsi) { |
|
var = btf_type_by_id(btf, vsi->type); |
|
if (i) |
|
btf_show(show, ","); |
|
btf_type_ops(var)->show(btf, var, vsi->type, |
|
data + vsi->offset, bits_offset, show); |
|
} |
|
btf_show_end_type(show); |
|
} |
|
|
|
static const struct btf_kind_operations datasec_ops = { |
|
.check_meta = btf_datasec_check_meta, |
|
.resolve = btf_datasec_resolve, |
|
.check_member = btf_df_check_member, |
|
.check_kflag_member = btf_df_check_kflag_member, |
|
.log_details = btf_datasec_log, |
|
.show = btf_datasec_show, |
|
}; |
|
|
|
static s32 btf_float_check_meta(struct btf_verifier_env *env, |
|
const struct btf_type *t, |
|
u32 meta_left) |
|
{ |
|
if (btf_type_vlen(t)) { |
|
btf_verifier_log_type(env, t, "vlen != 0"); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_kflag(t)) { |
|
btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
|
return -EINVAL; |
|
} |
|
|
|
if (t->size != 2 && t->size != 4 && t->size != 8 && t->size != 12 && |
|
t->size != 16) { |
|
btf_verifier_log_type(env, t, "Invalid type_size"); |
|
return -EINVAL; |
|
} |
|
|
|
btf_verifier_log_type(env, t, NULL); |
|
|
|
return 0; |
|
} |
|
|
|
static int btf_float_check_member(struct btf_verifier_env *env, |
|
const struct btf_type *struct_type, |
|
const struct btf_member *member, |
|
const struct btf_type *member_type) |
|
{ |
|
u64 start_offset_bytes; |
|
u64 end_offset_bytes; |
|
u64 misalign_bits; |
|
u64 align_bytes; |
|
u64 align_bits; |
|
|
|
/* Different architectures have different alignment requirements, so |
|
* here we check only for the reasonable minimum. This way we ensure |
|
* that types after CO-RE can pass the kernel BTF verifier. |
|
*/ |
|
align_bytes = min_t(u64, sizeof(void *), member_type->size); |
|
align_bits = align_bytes * BITS_PER_BYTE; |
|
div64_u64_rem(member->offset, align_bits, &misalign_bits); |
|
if (misalign_bits) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Member is not properly aligned"); |
|
return -EINVAL; |
|
} |
|
|
|
start_offset_bytes = member->offset / BITS_PER_BYTE; |
|
end_offset_bytes = start_offset_bytes + member_type->size; |
|
if (end_offset_bytes > struct_type->size) { |
|
btf_verifier_log_member(env, struct_type, member, |
|
"Member exceeds struct_size"); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void btf_float_log(struct btf_verifier_env *env, |
|
const struct btf_type *t) |
|
{ |
|
btf_verifier_log(env, "size=%u", t->size); |
|
} |
|
|
|
static const struct btf_kind_operations float_ops = { |
|
.check_meta = btf_float_check_meta, |
|
.resolve = btf_df_resolve, |
|
.check_member = btf_float_check_member, |
|
.check_kflag_member = btf_generic_check_kflag_member, |
|
.log_details = btf_float_log, |
|
.show = btf_df_show, |
|
}; |
|
|
|
static s32 btf_decl_tag_check_meta(struct btf_verifier_env *env, |
|
const struct btf_type *t, |
|
u32 meta_left) |
|
{ |
|
const struct btf_decl_tag *tag; |
|
u32 meta_needed = sizeof(*tag); |
|
s32 component_idx; |
|
const char *value; |
|
|
|
if (meta_left < meta_needed) { |
|
btf_verifier_log_basic(env, t, |
|
"meta_left:%u meta_needed:%u", |
|
meta_left, meta_needed); |
|
return -EINVAL; |
|
} |
|
|
|
value = btf_name_by_offset(env->btf, t->name_off); |
|
if (!value || !value[0]) { |
|
btf_verifier_log_type(env, t, "Invalid value"); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_vlen(t)) { |
|
btf_verifier_log_type(env, t, "vlen != 0"); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_kflag(t)) { |
|
btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
|
return -EINVAL; |
|
} |
|
|
|
component_idx = btf_type_decl_tag(t)->component_idx; |
|
if (component_idx < -1) { |
|
btf_verifier_log_type(env, t, "Invalid component_idx"); |
|
return -EINVAL; |
|
} |
|
|
|
btf_verifier_log_type(env, t, NULL); |
|
|
|
return meta_needed; |
|
} |
|
|
|
static int btf_decl_tag_resolve(struct btf_verifier_env *env, |
|
const struct resolve_vertex *v) |
|
{ |
|
const struct btf_type *next_type; |
|
const struct btf_type *t = v->t; |
|
u32 next_type_id = t->type; |
|
struct btf *btf = env->btf; |
|
s32 component_idx; |
|
u32 vlen; |
|
|
|
next_type = btf_type_by_id(btf, next_type_id); |
|
if (!next_type || !btf_type_is_decl_tag_target(next_type)) { |
|
btf_verifier_log_type(env, v->t, "Invalid type_id"); |
|
return -EINVAL; |
|
} |
|
|
|
if (!env_type_is_resolve_sink(env, next_type) && |
|
!env_type_is_resolved(env, next_type_id)) |
|
return env_stack_push(env, next_type, next_type_id); |
|
|
|
component_idx = btf_type_decl_tag(t)->component_idx; |
|
if (component_idx != -1) { |
|
if (btf_type_is_var(next_type) || btf_type_is_typedef(next_type)) { |
|
btf_verifier_log_type(env, v->t, "Invalid component_idx"); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_is_struct(next_type)) { |
|
vlen = btf_type_vlen(next_type); |
|
} else { |
|
/* next_type should be a function */ |
|
next_type = btf_type_by_id(btf, next_type->type); |
|
vlen = btf_type_vlen(next_type); |
|
} |
|
|
|
if ((u32)component_idx >= vlen) { |
|
btf_verifier_log_type(env, v->t, "Invalid component_idx"); |
|
return -EINVAL; |
|
} |
|
} |
|
|
|
env_stack_pop_resolved(env, next_type_id, 0); |
|
|
|
return 0; |
|
} |
|
|
|
static void btf_decl_tag_log(struct btf_verifier_env *env, const struct btf_type *t) |
|
{ |
|
btf_verifier_log(env, "type=%u component_idx=%d", t->type, |
|
btf_type_decl_tag(t)->component_idx); |
|
} |
|
|
|
static const struct btf_kind_operations decl_tag_ops = { |
|
.check_meta = btf_decl_tag_check_meta, |
|
.resolve = btf_decl_tag_resolve, |
|
.check_member = btf_df_check_member, |
|
.check_kflag_member = btf_df_check_kflag_member, |
|
.log_details = btf_decl_tag_log, |
|
.show = btf_df_show, |
|
}; |
|
|
|
static int btf_func_proto_check(struct btf_verifier_env *env, |
|
const struct btf_type *t) |
|
{ |
|
const struct btf_type *ret_type; |
|
const struct btf_param *args; |
|
const struct btf *btf; |
|
u16 nr_args, i; |
|
int err; |
|
|
|
btf = env->btf; |
|
args = (const struct btf_param *)(t + 1); |
|
nr_args = btf_type_vlen(t); |
|
|
|
/* Check func return type which could be "void" (t->type == 0) */ |
|
if (t->type) { |
|
u32 ret_type_id = t->type; |
|
|
|
ret_type = btf_type_by_id(btf, ret_type_id); |
|
if (!ret_type) { |
|
btf_verifier_log_type(env, t, "Invalid return type"); |
|
return -EINVAL; |
|
} |
|
|
|
if (btf_type_needs_resolve(ret_type) && |
|
!env_type_is_resolved(env, ret_type_id)) { |
|
err = btf_resolve(env, ret_type, ret_type_id); |
|
if (err) |
|
return err; |
|
} |
|
|
|
/* Ensure the return type is a type that has a size */ |
|
if (!btf_type_id_size(btf, &ret_type_id, NULL)) { |
|
btf_verifier_log_type(env, t, "Invalid return type"); |
|
return -EINVAL; |
|
} |
|
} |
|
|
|
if (!nr_args) |
|
return 0; |
|
|
|
/* Last func arg type_id could be 0 if it is a vararg */ |
|
if (!args[nr_args - 1].type) { |
|
if (args[nr_args - 1].name_off) { |
|
btf_verifier_log_type(env, t, "Invalid arg#%u", |
|
nr_args); |
|
return -EINVAL; |
|
} |
|
nr_args--; |
|
} |
|
|
|
err = 0; |
|
for (i = 0; i < nr_args; i++) { |
|
const struct btf_type *arg_type; |
|
u32 arg_type_id; |
|
|
|
arg_type_id = args[i].type; |
|
arg_type = btf_type_by_id(btf, arg_type_id); |
|
if (!arg_type) { |
|
btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); |
|
err = -EINVAL; |
|
break; |
|
} |
|
|
|
if (args[i].name_off && |
|
(!btf_name_offset_valid(btf, args[i].name_off) || |
|
!btf_name_valid_identifier(btf, args[i].name_off))) { |
|
btf_verifier_log_type(env, t, |
|
"Invalid arg#%u", i + 1); |
|
err = -EINVAL; |
|
break; |
|
} |
|
|
|
if (btf_type_needs_resolve(arg_type) && |
|
!env_type_is_resolved(env, arg_type_id)) { |
|
err = btf_resolve(env, arg_type, arg_type_id); |
|
if (err) |
|
break; |
|
} |
|
|
|
if (!btf_type_id_size(btf, &arg_type_id, NULL)) { |
|
btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); |
|
err = -EINVAL; |
|
break; |
|
} |
|
} |
|
|
|
return err; |
|
} |
|
|
|
static int btf_func_check(struct btf_verifier_env *env, |
|
const struct btf_type *t) |
|
{ |
|
const struct btf_type *proto_type; |
|
const struct btf_param *args; |
|
const struct btf *btf; |
|
u16 nr_args, i; |
|
|
|
btf = env->btf; |
|
proto_type = btf_type_by_id(btf, t->type); |
|
|
|
if (!proto_type || !btf_type_is_func_proto(proto_type)) { |
|
btf_verifier_log_type(env, t, "Invalid type_id"); |
|
return -EINVAL; |
|
} |
|
|
|
args = (const struct btf_param *)(proto_type + 1); |
|
nr_args = btf_type_vlen(proto_type); |
|
for (i = 0; i < nr_args; i++) { |
|
if (!args[i].name_off && args[i].type) { |
|
btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); |
|
return -EINVAL; |
|
} |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = { |
|
[BTF_KIND_INT] = &int_ops, |
|
[BTF_KIND_PTR] = &ptr_ops, |
|
[BTF_KIND_ARRAY] = &array_ops, |
|
[BTF_KIND_STRUCT] = &struct_ops, |
|
[BTF_KIND_UNION] = &struct_ops, |
|
[BTF_KIND_ENUM] = &enum_ops, |
|
[BTF_KIND_FWD] = &fwd_ops, |
|
[BTF_KIND_TYPEDEF] = &modifier_ops, |
|
[BTF_KIND_VOLATILE] = &modifier_ops, |
|
[BTF_KIND_CONST] = &modifier_ops, |
|
[BTF_KIND_RESTRICT] = &modifier_ops, |
|
[BTF_KIND_FUNC] = &func_ops, |
|
[BTF_KIND_FUNC_PROTO] = &func_proto_ops, |
|
[BTF_KIND_VAR] = &var_ops, |
|
[BTF_KIND_DATASEC] = &datasec_ops, |
|
[BTF_KIND_FLOAT] = &float_ops, |
|
[BTF_KIND_DECL_TAG] = &decl_tag_ops, |
|
[BTF_KIND_TYPE_TAG] = &modifier_ops, |
|
}; |
|
|
|
static s32 btf_check_meta(struct btf_verifier_env *env, |
|
const struct btf_type *t, |
|
u32 meta_left) |
|
{ |
|
u32 saved_meta_left = meta_left; |
|
s32 var_meta_size; |
|
|
|
if (meta_left < sizeof(*t)) { |
|
btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu", |
|
env->log_type_id, meta_left, sizeof(*t)); |
|
return -EINVAL; |
|
} |
|
meta_left -= sizeof(*t); |
|
|
|
if (t->info & ~BTF_INFO_MASK) { |
|
btf_verifier_log(env, "[%u] Invalid btf_info:%x", |
|
env->log_type_id, t->info); |
|
return -EINVAL; |
|
} |
|
|
|
if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX || |
|
BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) { |
|
btf_verifier_log(env, "[%u] Invalid kind:%u", |
|
env->log_type_id, BTF_INFO_KIND(t->info)); |
|
return -EINVAL; |
|
} |
|
|
|
if (!btf_name_offset_valid(env->btf, t->name_off)) { |
|
btf_verifier_log(env, "[%u] Invalid name_offset:%u", |
|
env->log_type_id, t->name_off); |
|
return -EINVAL; |
|
} |
|
|
|
var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left); |
|
if (var_meta_size < 0) |
|
return var_meta_size; |
|
|
|
meta_left -= var_meta_size; |
|
|
|
return saved_meta_left - meta_left; |
|
} |
|
|
|
static int btf_check_all_metas(struct btf_verifier_env *env) |
|
{ |
|
struct btf *btf = env->btf; |
|
struct btf_header *hdr; |
|
void *cur, *end; |
|
|
|
hdr = &btf->hdr; |
|
cur = btf->nohdr_data + hdr->type_off; |
|
end = cur + hdr->type_len; |
|
|
|
env->log_type_id = btf->base_btf ? btf->start_id : 1; |
|
while (cur < end) { |
|
struct btf_type *t = cur; |
|
s32 meta_size; |
|
|
|
meta_size = btf_check_meta(env, t, end - cur); |
|
if (meta_size < 0) |
|
return meta_size; |
|
|
|
btf_add_type(env, t); |
|
cur += meta_size; |
|
env->log_type_id++; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static bool btf_resolve_valid(struct btf_verifier_env *env, |
|
const struct btf_type *t, |
|
u32 type_id) |
|
{ |
|
struct btf *btf = env->btf; |
|
|
|
if (!env_type_is_resolved(env, type_id)) |
|
return false; |
|
|
|
if (btf_type_is_struct(t) || btf_type_is_datasec(t)) |
|
return !btf_resolved_type_id(btf, type_id) && |
|
!btf_resolved_type_size(btf, type_id); |
|
|
|
if (btf_type_is_decl_tag(t) || btf_type_is_func(t)) |
|
return btf_resolved_type_id(btf, type_id) && |
|
!btf_resolved_type_size(btf, type_id); |
|
|
|
if (btf_type_is_modifier(t) || btf_type_is_ptr(t) || |
|
btf_type_is_var(t)) { |
|
t = btf_type_id_resolve(btf, &type_id); |
|
return t && |
|
!btf_type_is_modifier(t) && |
|
!btf_type_is_var(t) && |
|
!btf_type_is_datasec(t); |
|
} |
|
|
|
if (btf_type_is_array(t)) { |
|
const struct btf_array *array = btf_type_array(t); |
|
const struct btf_type *elem_type; |
|
u32 elem_type_id = array->type; |
|
u32 elem_size; |
|
|
|
elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); |
|
return elem_type && !btf_type_is_modifier(elem_type) && |
|
(array->nelems * elem_size == |
|
btf_resolved_type_size(btf, type_id)); |
|
} |
|
|
|
return false; |
|
} |
|
|
|
static int btf_resolve(struct btf_verifier_env *env, |
|
const struct btf_type *t, u32 type_id) |
|
{ |
|
u32 save_log_type_id = env->log_type_id; |
|
const struct resolve_vertex *v; |
|
int err = 0; |
|
|
|
env->resolve_mode = RESOLVE_TBD; |
|
env_stack_push(env, t, type_id); |
|
while (!err && (v = env_stack_peak(env))) { |
|
env->log_type_id = v->type_id; |
|
err = btf_type_ops(v->t)->resolve(env, v); |
|
} |
|
|
|
env->log_type_id = type_id; |
|
if (err == -E2BIG) { |
|
btf_verifier_log_type(env, t, |
|
"Exceeded max resolving depth:%u", |
|
MAX_RESOLVE_DEPTH); |
|
} else if (err == -EEXIST) { |
|
btf_verifier_log_type(env, t, "Loop detected"); |
|
} |
|
|
|
/* Final sanity check */ |
|
if (!err && !btf_resolve_valid(env, t, type_id)) { |
|
btf_verifier_log_type(env, t, "Invalid resolve state"); |
|
err = -EINVAL; |
|
} |
|
|
|
env->log_type_id = save_log_type_id; |
|
return err; |
|
} |
|
|
|
static int btf_check_all_types(struct btf_verifier_env *env) |
|
{ |
|
struct btf *btf = env->btf; |
|
const struct btf_type *t; |
|
u32 type_id, i; |
|
int err; |
|
|
|
err = env_resolve_init(env); |
|
if (err) |
|
return err; |
|
|
|
env->phase++; |
|
for (i = btf->base_btf ? 0 : 1; i < btf->nr_types; i++) { |
|
type_id = btf->start_id + i; |
|
t = btf_type_by_id(btf, type_id); |
|
|
|
env->log_type_id = type_id; |
|
if (btf_type_needs_resolve(t) && |
|
!env_type_is_resolved(env, type_id)) { |
|
err = btf_resolve(env, t, type_id); |
|
if (err) |
|
return err; |
|
} |
|
|
|
if (btf_type_is_func_proto(t)) { |
|
err = btf_func_proto_check(env, t); |
|
if (err) |
|
return err; |
|
} |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int btf_parse_type_sec(struct btf_verifier_env *env) |
|
{ |
|
const struct btf_header *hdr = &env->btf->hdr; |
|
int err; |
|
|
|
/* Type section must align to 4 bytes */ |
|
if (hdr->type_off & (sizeof(u32) - 1)) { |
|
btf_verifier_log(env, "Unaligned type_off"); |
|
return -EINVAL; |
|
} |
|
|
|
if (!env->btf->base_btf && !hdr->type_len) { |
|
btf_verifier_log(env, "No type found"); |
|
return -EINVAL; |
|
} |
|
|
|
err = btf_check_all_metas(env); |
|
if (err) |
|
return err; |
|
|
|
return btf_check_all_types(env); |
|
} |
|
|
|
static int btf_parse_str_sec(struct btf_verifier_env *env) |
|
{ |
|
const struct btf_header *hdr; |
|
struct btf *btf = env->btf; |
|
const char *start, *end; |
|
|
|
hdr = &btf->hdr; |
|
start = btf->nohdr_data + hdr->str_off; |
|
end = start + hdr->str_len; |
|
|
|
if (end != btf->data + btf->data_size) { |
|
btf_verifier_log(env, "String section is not at the end"); |
|
return -EINVAL; |
|
} |
|
|
|
btf->strings = start; |
|
|
|
if (btf->base_btf && !hdr->str_len) |
|
return 0; |
|
if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || end[-1]) { |
|
btf_verifier_log(env, "Invalid string section"); |
|
return -EINVAL; |
|
} |
|
if (!btf->base_btf && start[0]) { |
|
btf_verifier_log(env, "Invalid string section"); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static const size_t btf_sec_info_offset[] = { |
|
offsetof(struct btf_header, type_off), |
|
offsetof(struct btf_header, str_off), |
|
}; |
|
|
|
static int btf_sec_info_cmp(const void *a, const void *b) |
|
{ |
|
const struct btf_sec_info *x = a; |
|
const struct btf_sec_info *y = b; |
|
|
|
return (int)(x->off - y->off) ? : (int)(x->len - y->len); |
|
} |
|
|
|
static int btf_check_sec_info(struct btf_verifier_env *env, |
|
u32 btf_data_size) |
|
{ |
|
struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)]; |
|
u32 total, expected_total, i; |
|
const struct btf_header *hdr; |
|
const struct btf *btf; |
|
|
|
btf = env->btf; |
|
hdr = &btf->hdr; |
|
|
|
/* Populate the secs from hdr */ |
|
for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) |
|
secs[i] = *(struct btf_sec_info *)((void *)hdr + |
|
btf_sec_info_offset[i]); |
|
|
|
sort(secs, ARRAY_SIZE(btf_sec_info_offset), |
|
sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL); |
|
|
|
/* Check for gaps and overlap among sections */ |
|
total = 0; |
|
expected_total = btf_data_size - hdr->hdr_len; |
|
for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) { |
|
if (expected_total < secs[i].off) { |
|
btf_verifier_log(env, "Invalid section offset"); |
|
return -EINVAL; |
|
} |
|
if (total < secs[i].off) { |
|
/* gap */ |
|
btf_verifier_log(env, "Unsupported section found"); |
|
return -EINVAL; |
|
} |
|
if (total > secs[i].off) { |
|
btf_verifier_log(env, "Section overlap found"); |
|
return -EINVAL; |
|
} |
|
if (expected_total - total < secs[i].len) { |
|
btf_verifier_log(env, |
|
"Total section length too long"); |
|
return -EINVAL; |
|
} |
|
total += secs[i].len; |
|
} |
|
|
|
/* There is data other than hdr and known sections */ |
|
if (expected_total != total) { |
|
btf_verifier_log(env, "Unsupported section found"); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int btf_parse_hdr(struct btf_verifier_env *env) |
|
{ |
|
u32 hdr_len, hdr_copy, btf_data_size; |
|
const struct btf_header *hdr; |
|
struct btf *btf; |
|
int err; |
|
|
|
btf = env->btf; |
|
btf_data_size = btf->data_size; |
|
|
|
if (btf_data_size < offsetofend(struct btf_header, hdr_len)) { |
|
btf_verifier_log(env, "hdr_len not found"); |
|
return -EINVAL; |
|
} |
|
|
|
hdr = btf->data; |
|
hdr_len = hdr->hdr_len; |
|
if (btf_data_size < hdr_len) { |
|
btf_verifier_log(env, "btf_header not found"); |
|
return -EINVAL; |
|
} |
|
|
|
/* Ensure the unsupported header fields are zero */ |
|
if (hdr_len > sizeof(btf->hdr)) { |
|
u8 *expected_zero = btf->data + sizeof(btf->hdr); |
|
u8 *end = btf->data + hdr_len; |
|
|
|
for (; expected_zero < end; expected_zero++) { |
|
if (*expected_zero) { |
|
btf_verifier_log(env, "Unsupported btf_header"); |
|
return -E2BIG; |
|
} |
|
} |
|
} |
|
|
|
hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr)); |
|
memcpy(&btf->hdr, btf->data, hdr_copy); |
|
|
|
hdr = &btf->hdr; |
|
|
|
btf_verifier_log_hdr(env, btf_data_size); |
|
|
|
if (hdr->magic != BTF_MAGIC) { |
|
btf_verifier_log(env, "Invalid magic"); |
|
return -EINVAL; |
|
} |
|
|
|
if (hdr->version != BTF_VERSION) { |
|
btf_verifier_log(env, "Unsupported version"); |
|
return -ENOTSUPP; |
|
} |
|
|
|
if (hdr->flags) { |
|
btf_verifier_log(env, "Unsupported flags"); |
|
return -ENOTSUPP; |
|
} |
|
|
|
if (!btf->base_btf && btf_data_size == hdr->hdr_len) { |
|
btf_verifier_log(env, "No data"); |
|
return -EINVAL; |
|
} |
|
|
|
err = btf_check_sec_info(env, btf_data_size); |
|
if (err) |
|
return err; |
|
|
|
return 0; |
|
} |
|
|
|
static struct btf *btf_parse(bpfptr_t btf_data, u32 btf_data_size, |
|
u32 log_level, char __user *log_ubuf, u32 log_size) |
|
{ |
|
struct btf_verifier_env *env = NULL; |
|
struct bpf_verifier_log *log; |
|
struct btf *btf = NULL; |
|
u8 *data; |
|
int err; |
|
|
|
if (btf_data_size > BTF_MAX_SIZE) |
|
return ERR_PTR(-E2BIG); |
|
|
|
env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); |
|
if (!env) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
log = &env->log; |
|
if (log_level || log_ubuf || log_size) { |
|
/* user requested verbose verifier output |
|
* and supplied buffer to store the verification trace |
|
*/ |
|
log->level = log_level; |
|
log->ubuf = log_ubuf; |
|
log->len_total = log_size; |
|
|
|
/* log attributes have to be sane */ |
|
if (!bpf_verifier_log_attr_valid(log)) { |
|
err = -EINVAL; |
|
goto errout; |
|
} |
|
} |
|
|
|
btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); |
|
if (!btf) { |
|
err = -ENOMEM; |
|
goto errout; |
|
} |
|
env->btf = btf; |
|
|
|
data = kvmalloc(btf_data_size, GFP_KERNEL | __GFP_NOWARN); |
|
if (!data) { |
|
err = -ENOMEM; |
|
goto errout; |
|
} |
|
|
|
btf->data = data; |
|
btf->data_size = btf_data_size; |
|
|
|
if (copy_from_bpfptr(data, btf_data, btf_data_size)) { |
|
err = -EFAULT; |
|
goto errout; |
|
} |
|
|
|
err = btf_parse_hdr(env); |
|
if (err) |
|
goto errout; |
|
|
|
btf->nohdr_data = btf->data + btf->hdr.hdr_len; |
|
|
|
err = btf_parse_str_sec(env); |
|
if (err) |
|
goto errout; |
|
|
|
err = btf_parse_type_sec(env); |
|
if (err) |
|
goto errout; |
|
|
|
if (log->level && bpf_verifier_log_full(log)) { |
|
err = -ENOSPC; |
|
goto errout; |
|
} |
|
|
|
btf_verifier_env_free(env); |
|
refcount_set(&btf->refcnt, 1); |
|
return btf; |
|
|
|
errout: |
|
btf_verifier_env_free(env); |
|
if (btf) |
|
btf_free(btf); |
|
return ERR_PTR(err); |
|
} |
|
|
|
extern char __weak __start_BTF[]; |
|
extern char __weak __stop_BTF[]; |
|
extern struct btf *btf_vmlinux; |
|
|
|
#define BPF_MAP_TYPE(_id, _ops) |
|
#define BPF_LINK_TYPE(_id, _name) |
|
static union { |
|
struct bpf_ctx_convert { |
|
#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ |
|
prog_ctx_type _id##_prog; \ |
|
kern_ctx_type _id##_kern; |
|
#include <linux/bpf_types.h> |
|
#undef BPF_PROG_TYPE |
|
} *__t; |
|
/* 't' is written once under lock. Read many times. */ |
|
const struct btf_type *t; |
|
} bpf_ctx_convert; |
|
enum { |
|
#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ |
|
__ctx_convert##_id, |
|
#include <linux/bpf_types.h> |
|
#undef BPF_PROG_TYPE |
|
__ctx_convert_unused, /* to avoid empty enum in extreme .config */ |
|
}; |
|
static u8 bpf_ctx_convert_map[] = { |
|
#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ |
|
[_id] = __ctx_convert##_id, |
|
#include <linux/bpf_types.h> |
|
#undef BPF_PROG_TYPE |
|
0, /* avoid empty array */ |
|
}; |
|
#undef BPF_MAP_TYPE |
|
#undef BPF_LINK_TYPE |
|
|
|
static const struct btf_member * |
|
btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf, |
|
const struct btf_type *t, enum bpf_prog_type prog_type, |
|
int arg) |
|
{ |
|
const struct btf_type *conv_struct; |
|
const struct btf_type *ctx_struct; |
|
const struct btf_member *ctx_type; |
|
const char *tname, *ctx_tname; |
|
|
|
conv_struct = bpf_ctx_convert.t; |
|
if (!conv_struct) { |
|
bpf_log(log, "btf_vmlinux is malformed\n"); |
|
return NULL; |
|
} |
|
t = btf_type_by_id(btf, t->type); |
|
while (btf_type_is_modifier(t)) |
|
t = btf_type_by_id(btf, t->type); |
|
if (!btf_type_is_struct(t)) { |
|
/* Only pointer to struct is supported for now. |
|
* That means that BPF_PROG_TYPE_TRACEPOINT with BTF |
|
* is not supported yet. |
|
* BPF_PROG_TYPE_RAW_TRACEPOINT is fine. |
|
*/ |
|
return NULL; |
|
} |
|
tname = btf_name_by_offset(btf, t->name_off); |
|
if (!tname) { |
|
bpf_log(log, "arg#%d struct doesn't have a name\n", arg); |
|
return NULL; |
|
} |
|
/* prog_type is valid bpf program type. No need for bounds check. */ |
|
ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2; |
|
/* ctx_struct is a pointer to prog_ctx_type in vmlinux. |
|
* Like 'struct __sk_buff' |
|
*/ |
|
ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type); |
|
if (!ctx_struct) |
|
/* should not happen */ |
|
return NULL; |
|
ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off); |
|
if (!ctx_tname) { |
|
/* should not happen */ |
|
bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n"); |
|
return NULL; |
|
} |
|
/* only compare that prog's ctx type name is the same as |
|
* kernel expects. No need to compare field by field. |
|
* It's ok for bpf prog to do: |
|
* struct __sk_buff {}; |
|
* int socket_filter_bpf_prog(struct __sk_buff *skb) |
|
* { // no fields of skb are ever used } |
|
*/ |
|
if (strcmp(ctx_tname, tname)) |
|
return NULL; |
|
return ctx_type; |
|
} |
|
|
|
static const struct bpf_map_ops * const btf_vmlinux_map_ops[] = { |
|
#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) |
|
#define BPF_LINK_TYPE(_id, _name) |
|
#define BPF_MAP_TYPE(_id, _ops) \ |
|
[_id] = &_ops, |
|
#include <linux/bpf_types.h> |
|
#undef BPF_PROG_TYPE |
|
#undef BPF_LINK_TYPE |
|
#undef BPF_MAP_TYPE |
|
}; |
|
|
|
static int btf_vmlinux_map_ids_init(const struct btf *btf, |
|
struct bpf_verifier_log *log) |
|
{ |
|
const struct bpf_map_ops *ops; |
|
int i, btf_id; |
|
|
|
for (i = 0; i < ARRAY_SIZE(btf_vmlinux_map_ops); ++i) { |
|
ops = btf_vmlinux_map_ops[i]; |
|
if (!ops || (!ops->map_btf_name && !ops->map_btf_id)) |
|
continue; |
|
if (!ops->map_btf_name || !ops->map_btf_id) { |
|
bpf_log(log, "map type %d is misconfigured\n", i); |
|
return -EINVAL; |
|
} |
|
btf_id = btf_find_by_name_kind(btf, ops->map_btf_name, |
|
BTF_KIND_STRUCT); |
|
if (btf_id < 0) |
|
return btf_id; |
|
*ops->map_btf_id = btf_id; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int btf_translate_to_vmlinux(struct bpf_verifier_log *log, |
|
struct btf *btf, |
|
const struct btf_type *t, |
|
enum bpf_prog_type prog_type, |
|
int arg) |
|
{ |
|
const struct btf_member *prog_ctx_type, *kern_ctx_type; |
|
|
|
prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg); |
|
if (!prog_ctx_type) |
|
return -ENOENT; |
|
kern_ctx_type = prog_ctx_type + 1; |
|
return kern_ctx_type->type; |
|
} |
|
|
|
BTF_ID_LIST(bpf_ctx_convert_btf_id) |
|
BTF_ID(struct, bpf_ctx_convert) |
|
|
|
struct btf *btf_parse_vmlinux(void) |
|
{ |
|
struct btf_verifier_env *env = NULL; |
|
struct bpf_verifier_log *log; |
|
struct btf *btf = NULL; |
|
int err; |
|
|
|
env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); |
|
if (!env) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
log = &env->log; |
|
log->level = BPF_LOG_KERNEL; |
|
|
|
btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); |
|
if (!btf) { |
|
err = -ENOMEM; |
|
goto errout; |
|
} |
|
env->btf = btf; |
|
|
|
btf->data = __start_BTF; |
|
btf->data_size = __stop_BTF - __start_BTF; |
|
btf->kernel_btf = true; |
|
snprintf(btf->name, sizeof(btf->name), "vmlinux"); |
|
|
|
err = btf_parse_hdr(env); |
|
if (err) |
|
goto errout; |
|
|
|
btf->nohdr_data = btf->data + btf->hdr.hdr_len; |
|
|
|
err = btf_parse_str_sec(env); |
|
if (err) |
|
goto errout; |
|
|
|
err = btf_check_all_metas(env); |
|
if (err) |
|
goto errout; |
|
|
|
/* btf_parse_vmlinux() runs under bpf_verifier_lock */ |
|
bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]); |
|
|
|
/* find bpf map structs for map_ptr access checking */ |
|
err = btf_vmlinux_map_ids_init(btf, log); |
|
if (err < 0) |
|
goto errout; |
|
|
|
bpf_struct_ops_init(btf, log); |
|
|
|
refcount_set(&btf->refcnt, 1); |
|
|
|
err = btf_alloc_id(btf); |
|
if (err) |
|
goto errout; |
|
|
|
btf_verifier_env_free(env); |
|
return btf; |
|
|
|
errout: |
|
btf_verifier_env_free(env); |
|
if (btf) { |
|
kvfree(btf->types); |
|
kfree(btf); |
|
} |
|
return ERR_PTR(err); |
|
} |
|
|
|
#ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
|
|
|
static struct btf *btf_parse_module(const char *module_name, const void *data, unsigned int data_size) |
|
{ |
|
struct btf_verifier_env *env = NULL; |
|
struct bpf_verifier_log *log; |
|
struct btf *btf = NULL, *base_btf; |
|
int err; |
|
|
|
base_btf = bpf_get_btf_vmlinux(); |
|
if (IS_ERR(base_btf)) |
|
return base_btf; |
|
if (!base_btf) |
|
return ERR_PTR(-EINVAL); |
|
|
|
env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); |
|
if (!env) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
log = &env->log; |
|
log->level = BPF_LOG_KERNEL; |
|
|
|
btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); |
|
if (!btf) { |
|
err = -ENOMEM; |
|
goto errout; |
|
} |
|
env->btf = btf; |
|
|
|
btf->base_btf = base_btf; |
|
btf->start_id = base_btf->nr_types; |
|
btf->start_str_off = base_btf->hdr.str_len; |
|
btf->kernel_btf = true; |
|
snprintf(btf->name, sizeof(btf->name), "%s", module_name); |
|
|
|
btf->data = kvmalloc(data_size, GFP_KERNEL | __GFP_NOWARN); |
|
if (!btf->data) { |
|
err = -ENOMEM; |
|
goto errout; |
|
} |
|
memcpy(btf->data, data, data_size); |
|
btf->data_size = data_size; |
|
|
|
err = btf_parse_hdr(env); |
|
if (err) |
|
goto errout; |
|
|
|
btf->nohdr_data = btf->data + btf->hdr.hdr_len; |
|
|
|
err = btf_parse_str_sec(env); |
|
if (err) |
|
goto errout; |
|
|
|
err = btf_check_all_metas(env); |
|
if (err) |
|
goto errout; |
|
|
|
btf_verifier_env_free(env); |
|
refcount_set(&btf->refcnt, 1); |
|
return btf; |
|
|
|
errout: |
|
btf_verifier_env_free(env); |
|
if (btf) { |
|
kvfree(btf->data); |
|
kvfree(btf->types); |
|
kfree(btf); |
|
} |
|
return ERR_PTR(err); |
|
} |
|
|
|
#endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ |
|
|
|
struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog) |
|
{ |
|
struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
|
|
|
if (tgt_prog) |
|
return tgt_prog->aux->btf; |
|
else |
|
return prog->aux->attach_btf; |
|
} |
|
|
|
static bool is_int_ptr(struct btf *btf, const struct btf_type *t) |
|
{ |
|
/* t comes in already as a pointer */ |
|
t = btf_type_by_id(btf, t->type); |
|
|
|
/* allow const */ |
|
if (BTF_INFO_KIND(t->info) == BTF_KIND_CONST) |
|
t = btf_type_by_id(btf, t->type); |
|
|
|
return btf_type_is_int(t); |
|
} |
|
|
|
bool btf_ctx_access(int off, int size, enum bpf_access_type type, |
|
const struct bpf_prog *prog, |
|
struct bpf_insn_access_aux *info) |
|
{ |
|
const struct btf_type *t = prog->aux->attach_func_proto; |
|
struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
|
struct btf *btf = bpf_prog_get_target_btf(prog); |
|
const char *tname = prog->aux->attach_func_name; |
|
struct bpf_verifier_log *log = info->log; |
|
const struct btf_param *args; |
|
const char *tag_value; |
|
u32 nr_args, arg; |
|
int i, ret; |
|
|
|
if (off % 8) { |
|
bpf_log(log, "func '%s' offset %d is not multiple of 8\n", |
|
tname, off); |
|
return false; |
|
} |
|
arg = off / 8; |
|
args = (const struct btf_param *)(t + 1); |
|
/* if (t == NULL) Fall back to default BPF prog with |
|
* MAX_BPF_FUNC_REG_ARGS u64 arguments. |
|
*/ |
|
nr_args = t ? btf_type_vlen(t) : MAX_BPF_FUNC_REG_ARGS; |
|
if (prog->aux->attach_btf_trace) { |
|
/* skip first 'void *__data' argument in btf_trace_##name typedef */ |
|
args++; |
|
nr_args--; |
|
} |
|
|
|
if (arg > nr_args) { |
|
bpf_log(log, "func '%s' doesn't have %d-th argument\n", |
|
tname, arg + 1); |
|
return false; |
|
} |
|
|
|
if (arg == nr_args) { |
|
switch (prog->expected_attach_type) { |
|
case BPF_LSM_MAC: |
|
case BPF_TRACE_FEXIT: |
|
/* When LSM programs are attached to void LSM hooks |
|
* they use FEXIT trampolines and when attached to |
|
* int LSM hooks, they use MODIFY_RETURN trampolines. |
|
* |
|
* While the LSM programs are BPF_MODIFY_RETURN-like |
|
* the check: |
|
* |
|
* if (ret_type != 'int') |
|
* return -EINVAL; |
|
* |
|
* is _not_ done here. This is still safe as LSM hooks |
|
* have only void and int return types. |
|
*/ |
|
if (!t) |
|
return true; |
|
t = btf_type_by_id(btf, t->type); |
|
break; |
|
case BPF_MODIFY_RETURN: |
|
/* For now the BPF_MODIFY_RETURN can only be attached to |
|
* functions that return an int. |
|
*/ |
|
if (!t) |
|
return false; |
|
|
|
t = btf_type_skip_modifiers(btf, t->type, NULL); |
|
if (!btf_type_is_small_int(t)) { |
|
bpf_log(log, |
|
"ret type %s not allowed for fmod_ret\n", |
|
btf_kind_str[BTF_INFO_KIND(t->info)]); |
|
return false; |
|
} |
|
break; |
|
default: |
|
bpf_log(log, "func '%s' doesn't have %d-th argument\n", |
|
tname, arg + 1); |
|
return false; |
|
} |
|
} else { |
|
if (!t) |
|
/* Default prog with MAX_BPF_FUNC_REG_ARGS args */ |
|
return true; |
|
t = btf_type_by_id(btf, args[arg].type); |
|
} |
|
|
|
/* skip modifiers */ |
|
while (btf_type_is_modifier(t)) |
|
t = btf_type_by_id(btf, t->type); |
|
if (btf_type_is_small_int(t) || btf_type_is_enum(t)) |
|
/* accessing a scalar */ |
|
return true; |
|
if (!btf_type_is_ptr(t)) { |
|
bpf_log(log, |
|
"func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n", |
|
tname, arg, |
|
__btf_name_by_offset(btf, t->name_off), |
|
btf_kind_str[BTF_INFO_KIND(t->info)]); |
|
return false; |
|
} |
|
|
|
/* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */ |
|
for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { |
|
const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; |
|
u32 type, flag; |
|
|
|
type = base_type(ctx_arg_info->reg_type); |
|
flag = type_flag(ctx_arg_info->reg_type); |
|
if (ctx_arg_info->offset == off && type == PTR_TO_BUF && |
|
(flag & PTR_MAYBE_NULL)) { |
|
info->reg_type = ctx_arg_info->reg_type; |
|
return true; |
|
} |
|
} |
|
|
|
if (t->type == 0) |
|
/* This is a pointer to void. |
|
* It is the same as scalar from the verifier safety pov. |
|
* No further pointer walking is allowed. |
|
*/ |
|
return true; |
|
|
|
if (is_int_ptr(btf, t)) |
|
return true; |
|
|
|
/* this is a pointer to another type */ |
|
for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { |
|
const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; |
|
|
|
if (ctx_arg_info->offset == off) { |
|
if (!ctx_arg_info->btf_id) { |
|
bpf_log(log,"invalid btf_id for context argument offset %u\n", off); |
|
return false; |
|
} |
|
|
|
info->reg_type = ctx_arg_info->reg_type; |
|
info->btf = btf_vmlinux; |
|
info->btf_id = ctx_arg_info->btf_id; |
|
return true; |
|
} |
|
} |
|
|
|
info->reg_type = PTR_TO_BTF_ID; |
|
if (tgt_prog) { |
|
enum bpf_prog_type tgt_type; |
|
|
|
if (tgt_prog->type == BPF_PROG_TYPE_EXT) |
|
tgt_type = tgt_prog->aux->saved_dst_prog_type; |
|
else |
|
tgt_type = tgt_prog->type; |
|
|
|
ret = btf_translate_to_vmlinux(log, btf, t, tgt_type, arg); |
|
if (ret > 0) { |
|
info->btf = btf_vmlinux; |
|
info->btf_id = ret; |
|
return true; |
|
} else { |
|
return false; |
|
} |
|
} |
|
|
|
info->btf = btf; |
|
info->btf_id = t->type; |
|
t = btf_type_by_id(btf, t->type); |
|
|
|
if (btf_type_is_type_tag(t)) { |
|
tag_value = __btf_name_by_offset(btf, t->name_off); |
|
if (strcmp(tag_value, "user") == 0) |
|
info->reg_type |= MEM_USER; |
|
if (strcmp(tag_value, "percpu") == 0) |
|
info->reg_type |= MEM_PERCPU; |
|
} |
|
|
|
/* skip modifiers */ |
|
while (btf_type_is_modifier(t)) { |
|
info->btf_id = t->type; |
|
t = btf_type_by_id(btf, t->type); |
|
} |
|
if (!btf_type_is_struct(t)) { |
|
bpf_log(log, |
|
"func '%s' arg%d type %s is not a struct\n", |
|
tname, arg, btf_kind_str[BTF_INFO_KIND(t->info)]); |
|
return false; |
|
} |
|
bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n", |
|
tname, arg, info->btf_id, btf_kind_str[BTF_INFO_KIND(t->info)], |
|
__btf_name_by_offset(btf, t->name_off)); |
|
return true; |
|
} |
|
|
|
enum bpf_struct_walk_result { |
|
/* < 0 error */ |
|
WALK_SCALAR = 0, |
|
WALK_PTR, |
|
WALK_STRUCT, |
|
}; |
|
|
|
static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf, |
|
const struct btf_type *t, int off, int size, |
|
u32 *next_btf_id, enum bpf_type_flag *flag) |
|
{ |
|
u32 i, moff, mtrue_end, msize = 0, total_nelems = 0; |
|
const struct btf_type *mtype, *elem_type = NULL; |
|
const struct btf_member *member; |
|
const char *tname, *mname, *tag_value; |
|
u32 vlen, elem_id, mid; |
|
|
|
again: |
|
tname = __btf_name_by_offset(btf, t->name_off); |
|
if (!btf_type_is_struct(t)) { |
|
bpf_log(log, "Type '%s' is not a struct\n", tname); |
|
return -EINVAL; |
|
} |
|
|
|
vlen = btf_type_vlen(t); |
|
if (off + size > t->size) { |
|
/* If the last element is a variable size array, we may |
|
* need to relax the rule. |
|
*/ |
|
struct btf_array *array_elem; |
|
|
|
if (vlen == 0) |
|
goto error; |
|
|
|
member = btf_type_member(t) + vlen - 1; |
|
mtype = btf_type_skip_modifiers(btf, member->type, |
|
NULL); |
|
if (!btf_type_is_array(mtype)) |
|
goto error; |
|
|
|
array_elem = (struct btf_array *)(mtype + 1); |
|
if (array_elem->nelems != 0) |
|
goto error; |
|
|
|
moff = __btf_member_bit_offset(t, member) / 8; |
|
if (off < moff) |
|
goto error; |
|
|
|
/* Only allow structure for now, can be relaxed for |
|
* other types later. |
|
*/ |
|
t = btf_type_skip_modifiers(btf, array_elem->type, |
|
NULL); |
|
if (!btf_type_is_struct(t)) |
|
goto error; |
|
|
|
off = (off - moff) % t->size; |
|
goto again; |
|
|
|
error: |
|
bpf_log(log, "access beyond struct %s at off %u size %u\n", |
|
tname, off, size); |
|
return -EACCES; |
|
} |
|
|
|
for_each_member(i, t, member) { |
|
/* offset of the field in bytes */ |
|
moff = __btf_member_bit_offset(t, member) / 8; |
|
if (off + size <= moff) |
|
/* won't find anything, field is already too far */ |
|
break; |
|
|
|
if (__btf_member_bitfield_size(t, member)) { |
|
u32 end_bit = __btf_member_bit_offset(t, member) + |
|
__btf_member_bitfield_size(t, member); |
|
|
|
/* off <= moff instead of off == moff because clang |
|
* does not generate a BTF member for anonymous |
|
* bitfield like the ":16" here: |
|
* struct { |
|
* int :16; |
|
* int x:8; |
|
* }; |
|
*/ |
|
if (off <= moff && |
|
BITS_ROUNDUP_BYTES(end_bit) <= off + size) |
|
return WALK_SCALAR; |
|
|
|
/* off may be accessing a following member |
|
* |
|
* or |
|
* |
|
* Doing partial access at either end of this |
|
* bitfield. Continue on this case also to |
|
* treat it as not accessing this bitfield |
|
* and eventually error out as field not |
|
* found to keep it simple. |
|
* It could be relaxed if there was a legit |
|
* partial access case later. |
|
*/ |
|
continue; |
|
} |
|
|
|
/* In case of "off" is pointing to holes of a struct */ |
|
if (off < moff) |
|
break; |
|
|
|
/* type of the field */ |
|
mid = member->type; |
|
mtype = btf_type_by_id(btf, member->type); |
|
mname = __btf_name_by_offset(btf, member->name_off); |
|
|
|
mtype = __btf_resolve_size(btf, mtype, &msize, |
|
&elem_type, &elem_id, &total_nelems, |
|
&mid); |
|
if (IS_ERR(mtype)) { |
|
bpf_log(log, "field %s doesn't have size\n", mname); |
|
return -EFAULT; |
|
} |
|
|
|
mtrue_end = moff + msize; |
|
if (off >= mtrue_end) |
|
/* no overlap with member, keep iterating */ |
|
continue; |
|
|
|
if (btf_type_is_array(mtype)) { |
|
u32 elem_idx; |
|
|
|
/* __btf_resolve_size() above helps to |
|
* linearize a multi-dimensional array. |
|
* |
|
* The logic here is treating an array |
|
* in a struct as the following way: |
|
* |
|
* struct outer { |
|
* struct inner array[2][2]; |
|
* }; |
|
* |
|
* looks like: |
|
* |
|
* struct outer { |
|
* struct inner array_elem0; |
|
* struct inner array_elem1; |
|
* struct inner array_elem2; |
|
* struct inner array_elem3; |
|
* }; |
|
* |
|
* When accessing outer->array[1][0], it moves |
|
* moff to "array_elem2", set mtype to |
|
* "struct inner", and msize also becomes |
|
* sizeof(struct inner). Then most of the |
|
* remaining logic will fall through without |
|
* caring the current member is an array or |
|
* not. |
|
* |
|
* Unlike mtype/msize/moff, mtrue_end does not |
|
* change. The naming difference ("_true") tells |
|
* that it is not always corresponding to |
|
* the current mtype/msize/moff. |
|
* It is the true end of the current |
|
* member (i.e. array in this case). That |
|
* will allow an int array to be accessed like |
|
* a scratch space, |
|
* i.e. allow access beyond the size of |
|
* the array's element as long as it is |
|
* within the mtrue_end boundary. |
|
*/ |
|
|
|
/* skip empty array */ |
|
if (moff == mtrue_end) |
|
continue; |
|
|
|
msize /= total_nelems; |
|
elem_idx = (off - moff) / msize; |
|
moff += elem_idx * msize; |
|
mtype = elem_type; |
|
mid = elem_id; |
|
} |
|
|
|
/* the 'off' we're looking for is either equal to start |
|
* of this field or inside of this struct |
|
*/ |
|
if (btf_type_is_struct(mtype)) { |
|
/* our field must be inside that union or struct */ |
|
t = mtype; |
|
|
|
/* return if the offset matches the member offset */ |
|
if (off == moff) { |
|
*next_btf_id = mid; |
|
return WALK_STRUCT; |
|
} |
|
|
|
/* adjust offset we're looking for */ |
|
off -= moff; |
|
goto again; |
|
} |
|
|
|
if (btf_type_is_ptr(mtype)) { |
|
const struct btf_type *stype, *t; |
|
enum bpf_type_flag tmp_flag = 0; |
|
u32 id; |
|
|
|
if (msize != size || off != moff) { |
|
bpf_log(log, |
|
"cannot access ptr member %s with moff %u in struct %s with off %u size %u\n", |
|
mname, moff, tname, off, size); |
|
return -EACCES; |
|
} |
|
|
|
/* check type tag */ |
|
t = btf_type_by_id(btf, mtype->type); |
|
if (btf_type_is_type_tag(t)) { |
|
tag_value = __btf_name_by_offset(btf, t->name_off); |
|
/* check __user tag */ |
|
if (strcmp(tag_value, "user") == 0) |
|
tmp_flag = MEM_USER; |
|
/* check __percpu tag */ |
|
if (strcmp(tag_value, "percpu") == 0) |
|
tmp_flag = MEM_PERCPU; |
|
} |
|
|
|
stype = btf_type_skip_modifiers(btf, mtype->type, &id); |
|
if (btf_type_is_struct(stype)) { |
|
*next_btf_id = id; |
|
*flag = tmp_flag; |
|
return WALK_PTR; |
|
} |
|
} |
|
|
|
/* Allow more flexible access within an int as long as |
|
* it is within mtrue_end. |
|
* Since mtrue_end could be the end of an array, |
|
* that also allows using an array of int as a scratch |
|
* space. e.g. skb->cb[]. |
|
*/ |
|
if (off + size > mtrue_end) { |
|
bpf_log(log, |
|
"access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n", |
|
mname, mtrue_end, tname, off, size); |
|
return -EACCES; |
|
} |
|
|
|
return WALK_SCALAR; |
|
} |
|
bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off); |
|
return -EINVAL; |
|
} |
|
|
|
int btf_struct_access(struct bpf_verifier_log *log, const struct btf *btf, |
|
const struct btf_type *t, int off, int size, |
|
enum bpf_access_type atype __maybe_unused, |
|
u32 *next_btf_id, enum bpf_type_flag *flag) |
|
{ |
|
enum bpf_type_flag tmp_flag = 0; |
|
int err; |
|
u32 id; |
|
|
|
do { |
|
err = btf_struct_walk(log, btf, t, off, size, &id, &tmp_flag); |
|
|
|
switch (err) { |
|
case WALK_PTR: |
|
/* If we found the pointer or scalar on t+off, |
|
* we're done. |
|
*/ |
|
*next_btf_id = id; |
|
*flag = tmp_flag; |
|
return PTR_TO_BTF_ID; |
|
case WALK_SCALAR: |
|
return SCALAR_VALUE; |
|
case WALK_STRUCT: |
|
/* We found nested struct, so continue the search |
|
* by diving in it. At this point the offset is |
|
* aligned with the new type, so set it to 0. |
|
*/ |
|
t = btf_type_by_id(btf, id); |
|
off = 0; |
|
break; |
|
default: |
|
/* It's either error or unknown return value.. |
|
* scream and leave. |
|
*/ |
|
if (WARN_ONCE(err > 0, "unknown btf_struct_walk return value")) |
|
return -EINVAL; |
|
return err; |
|
} |
|
} while (t); |
|
|
|
return -EINVAL; |
|
} |
|
|
|
/* Check that two BTF types, each specified as an BTF object + id, are exactly |
|
* the same. Trivial ID check is not enough due to module BTFs, because we can |
|
* end up with two different module BTFs, but IDs point to the common type in |
|
* vmlinux BTF. |
|
*/ |
|
static bool btf_types_are_same(const struct btf *btf1, u32 id1, |
|
const struct btf *btf2, u32 id2) |
|
{ |
|
if (id1 != id2) |
|
return false; |
|
if (btf1 == btf2) |
|
return true; |
|
return btf_type_by_id(btf1, id1) == btf_type_by_id(btf2, id2); |
|
} |
|
|
|
bool btf_struct_ids_match(struct bpf_verifier_log *log, |
|
const struct btf *btf, u32 id, int off, |
|
const struct btf *need_btf, u32 need_type_id) |
|
{ |
|
const struct btf_type *type; |
|
enum bpf_type_flag flag; |
|
int err; |
|
|
|
/* Are we already done? */ |
|
if (off == 0 && btf_types_are_same(btf, id, need_btf, need_type_id)) |
|
return true; |
|
|
|
again: |
|
type = btf_type_by_id(btf, id); |
|
if (!type) |
|
return false; |
|
err = btf_struct_walk(log, btf, type, off, 1, &id, &flag); |
|
if (err != WALK_STRUCT) |
|
return false; |
|
|
|
/* We found nested struct object. If it matches |
|
* the requested ID, we're done. Otherwise let's |
|
* continue the search with offset 0 in the new |
|
* type. |
|
*/ |
|
if (!btf_types_are_same(btf, id, need_btf, need_type_id)) { |
|
off = 0; |
|
goto again; |
|
} |
|
|
|
return true; |
|
} |
|
|
|
static int __get_type_size(struct btf *btf, u32 btf_id, |
|
const struct btf_type **bad_type) |
|
{ |
|
const struct btf_type *t; |
|
|
|
if (!btf_id) |
|
/* void */ |
|
return 0; |
|
t = btf_type_by_id(btf, btf_id); |
|
while (t && btf_type_is_modifier(t)) |
|
t = btf_type_by_id(btf, t->type); |
|
if (!t) { |
|
*bad_type = btf_type_by_id(btf, 0); |
|
return -EINVAL; |
|
} |
|
if (btf_type_is_ptr(t)) |
|
/* kernel size of pointer. Not BPF's size of pointer*/ |
|
return sizeof(void *); |
|
if (btf_type_is_int(t) || btf_type_is_enum(t)) |
|
return t->size; |
|
*bad_type = t; |
|
return -EINVAL; |
|
} |
|
|
|
int btf_distill_func_proto(struct bpf_verifier_log *log, |
|
struct btf *btf, |
|
const struct btf_type *func, |
|
const char *tname, |
|
struct btf_func_model *m) |
|
{ |
|
const struct btf_param *args; |
|
const struct btf_type *t; |
|
u32 i, nargs; |
|
int ret; |
|
|
|
if (!func) { |
|
/* BTF function prototype doesn't match the verifier types. |
|
* Fall back to MAX_BPF_FUNC_REG_ARGS u64 args. |
|
*/ |
|
for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++) |
|
m->arg_size[i] = 8; |
|
m->ret_size = 8; |
|
m->nr_args = MAX_BPF_FUNC_REG_ARGS; |
|
return 0; |
|
} |
|
args = (const struct btf_param *)(func + 1); |
|
nargs = btf_type_vlen(func); |
|
if (nargs > MAX_BPF_FUNC_ARGS) { |
|
bpf_log(log, |
|
"The function %s has %d arguments. Too many.\n", |
|
tname, nargs); |
|
return -EINVAL; |
|
} |
|
ret = __get_type_size(btf, func->type, &t); |
|
if (ret < 0) { |
|
bpf_log(log, |
|
"The function %s return type %s is unsupported.\n", |
|
tname, btf_kind_str[BTF_INFO_KIND(t->info)]); |
|
return -EINVAL; |
|
} |
|
m->ret_size = ret; |
|
|
|
for (i = 0; i < nargs; i++) { |
|
if (i == nargs - 1 && args[i].type == 0) { |
|
bpf_log(log, |
|
"The function %s with variable args is unsupported.\n", |
|
tname); |
|
return -EINVAL; |
|
} |
|
ret = __get_type_size(btf, args[i].type, &t); |
|
if (ret < 0) { |
|
bpf_log(log, |
|
"The function %s arg%d type %s is unsupported.\n", |
|
tname, i, btf_kind_str[BTF_INFO_KIND(t->info)]); |
|
return -EINVAL; |
|
} |
|
if (ret == 0) { |
|
bpf_log(log, |
|
"The function %s has malformed void argument.\n", |
|
tname); |
|
return -EINVAL; |
|
} |
|
m->arg_size[i] = ret; |
|
} |
|
m->nr_args = nargs; |
|
return 0; |
|
} |
|
|
|
/* Compare BTFs of two functions assuming only scalars and pointers to context. |
|
* t1 points to BTF_KIND_FUNC in btf1 |
|
* t2 points to BTF_KIND_FUNC in btf2 |
|
* Returns: |
|
* EINVAL - function prototype mismatch |
|
* EFAULT - verifier bug |
|
* 0 - 99% match. The last 1% is validated by the verifier. |
|
*/ |
|
static int btf_check_func_type_match(struct bpf_verifier_log *log, |
|
struct btf *btf1, const struct btf_type *t1, |
|
struct btf *btf2, const struct btf_type *t2) |
|
{ |
|
const struct btf_param *args1, *args2; |
|
const char *fn1, *fn2, *s1, *s2; |
|
u32 nargs1, nargs2, i; |
|
|
|
fn1 = btf_name_by_offset(btf1, t1->name_off); |
|
fn2 = btf_name_by_offset(btf2, t2->name_off); |
|
|
|
if (btf_func_linkage(t1) != BTF_FUNC_GLOBAL) { |
|
bpf_log(log, "%s() is not a global function\n", fn1); |
|
return -EINVAL; |
|
} |
|
if (btf_func_linkage(t2) != BTF_FUNC_GLOBAL) { |
|
bpf_log(log, "%s() is not a global function\n", fn2); |
|
return -EINVAL; |
|
} |
|
|
|
t1 = btf_type_by_id(btf1, t1->type); |
|
if (!t1 || !btf_type_is_func_proto(t1)) |
|
return -EFAULT; |
|
t2 = btf_type_by_id(btf2, t2->type); |
|
if (!t2 || !btf_type_is_func_proto(t2)) |
|
return -EFAULT; |
|
|
|
args1 = (const struct btf_param *)(t1 + 1); |
|
nargs1 = btf_type_vlen(t1); |
|
args2 = (const struct btf_param *)(t2 + 1); |
|
nargs2 = btf_type_vlen(t2); |
|
|
|
if (nargs1 != nargs2) { |
|
bpf_log(log, "%s() has %d args while %s() has %d args\n", |
|
fn1, nargs1, fn2, nargs2); |
|
return -EINVAL; |
|
} |
|
|
|
t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); |
|
t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); |
|
if (t1->info != t2->info) { |
|
bpf_log(log, |
|
"Return type %s of %s() doesn't match type %s of %s()\n", |
|
btf_type_str(t1), fn1, |
|
btf_type_str(t2), fn2); |
|
return -EINVAL; |
|
} |
|
|
|
for (i = 0; i < nargs1; i++) { |
|
t1 = btf_type_skip_modifiers(btf1, args1[i].type, NULL); |
|
t2 = btf_type_skip_modifiers(btf2, args2[i].type, NULL); |
|
|
|
if (t1->info != t2->info) { |
|
bpf_log(log, "arg%d in %s() is %s while %s() has %s\n", |
|
i, fn1, btf_type_str(t1), |
|
fn2, btf_type_str(t2)); |
|
return -EINVAL; |
|
} |
|
if (btf_type_has_size(t1) && t1->size != t2->size) { |
|
bpf_log(log, |
|
"arg%d in %s() has size %d while %s() has %d\n", |
|
i, fn1, t1->size, |
|
fn2, t2->size); |
|
return -EINVAL; |
|
} |
|
|
|
/* global functions are validated with scalars and pointers |
|
* to context only. And only global functions can be replaced. |
|
* Hence type check only those types. |
|
*/ |
|
if (btf_type_is_int(t1) || btf_type_is_enum(t1)) |
|
continue; |
|
if (!btf_type_is_ptr(t1)) { |
|
bpf_log(log, |
|
"arg%d in %s() has unrecognized type\n", |
|
i, fn1); |
|
return -EINVAL; |
|
} |
|
t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); |
|
t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); |
|
if (!btf_type_is_struct(t1)) { |
|
bpf_log(log, |
|
"arg%d in %s() is not a pointer to context\n", |
|
i, fn1); |
|
return -EINVAL; |
|
} |
|
if (!btf_type_is_struct(t2)) { |
|
bpf_log(log, |
|
"arg%d in %s() is not a pointer to context\n", |
|
i, fn2); |
|
return -EINVAL; |
|
} |
|
/* This is an optional check to make program writing easier. |
|
* Compare names of structs and report an error to the user. |
|
* btf_prepare_func_args() already checked that t2 struct |
|
* is a context type. btf_prepare_func_args() will check |
|
* later that t1 struct is a context type as well. |
|
*/ |
|
s1 = btf_name_by_offset(btf1, t1->name_off); |
|
s2 = btf_name_by_offset(btf2, t2->name_off); |
|
if (strcmp(s1, s2)) { |
|
bpf_log(log, |
|
"arg%d %s(struct %s *) doesn't match %s(struct %s *)\n", |
|
i, fn1, s1, fn2, s2); |
|
return -EINVAL; |
|
} |
|
} |
|
return 0; |
|
} |
|
|
|
/* Compare BTFs of given program with BTF of target program */ |
|
int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog, |
|
struct btf *btf2, const struct btf_type *t2) |
|
{ |
|
struct btf *btf1 = prog->aux->btf; |
|
const struct btf_type *t1; |
|
u32 btf_id = 0; |
|
|
|
if (!prog->aux->func_info) { |
|
bpf_log(log, "Program extension requires BTF\n"); |
|
return -EINVAL; |
|
} |
|
|
|
btf_id = prog->aux->func_info[0].type_id; |
|
if (!btf_id) |
|
return -EFAULT; |
|
|
|
t1 = btf_type_by_id(btf1, btf_id); |
|
if (!t1 || !btf_type_is_func(t1)) |
|
return -EFAULT; |
|
|
|
return btf_check_func_type_match(log, btf1, t1, btf2, t2); |
|
} |
|
|
|
static u32 *reg2btf_ids[__BPF_REG_TYPE_MAX] = { |
|
#ifdef CONFIG_NET |
|
[PTR_TO_SOCKET] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK], |
|
[PTR_TO_SOCK_COMMON] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON], |
|
[PTR_TO_TCP_SOCK] = &btf_sock_ids[BTF_SOCK_TYPE_TCP], |
|
#endif |
|
}; |
|
|
|
/* Returns true if struct is composed of scalars, 4 levels of nesting allowed */ |
|
static bool __btf_type_is_scalar_struct(struct bpf_verifier_log *log, |
|
const struct btf *btf, |
|
const struct btf_type *t, int rec) |
|
{ |
|
const struct btf_type *member_type; |
|
const struct btf_member *member; |
|
u32 i; |
|
|
|
if (!btf_type_is_struct(t)) |
|
return false; |
|
|
|
for_each_member(i, t, member) { |
|
const struct btf_array *array; |
|
|
|
member_type = btf_type_skip_modifiers(btf, member->type, NULL); |
|
if (btf_type_is_struct(member_type)) { |
|
if (rec >= 3) { |
|
bpf_log(log, "max struct nesting depth exceeded\n"); |
|
return false; |
|
} |
|
if (!__btf_type_is_scalar_struct(log, btf, member_type, rec + 1)) |
|
return false; |
|
continue; |
|
} |
|
if (btf_type_is_array(member_type)) { |
|
array = btf_type_array(member_type); |
|
if (!array->nelems) |
|
return false; |
|
member_type = btf_type_skip_modifiers(btf, array->type, NULL); |
|
if (!btf_type_is_scalar(member_type)) |
|
return false; |
|
continue; |
|
} |
|
if (!btf_type_is_scalar(member_type)) |
|
return false; |
|
} |
|
return true; |
|
} |
|
|
|
static bool is_kfunc_arg_mem_size(const struct btf *btf, |
|
const struct btf_param *arg, |
|
const struct bpf_reg_state *reg) |
|
{ |
|
int len, sfx_len = sizeof("__sz") - 1; |
|
const struct btf_type *t; |
|
const char *param_name; |
|
|
|
t = btf_type_skip_modifiers(btf, arg->type, NULL); |
|
if (!btf_type_is_scalar(t) || reg->type != SCALAR_VALUE) |
|
return false; |
|
|
|
/* In the future, this can be ported to use BTF tagging */ |
|
param_name = btf_name_by_offset(btf, arg->name_off); |
|
if (str_is_empty(param_name)) |
|
return false; |
|
len = strlen(param_name); |
|
if (len < sfx_len) |
|
return false; |
|
param_name += len - sfx_len; |
|
if (strncmp(param_name, "__sz", sfx_len)) |
|
return false; |
|
|
|
return true; |
|
} |
|
|
|
static int btf_check_func_arg_match(struct bpf_verifier_env *env, |
|
const struct btf *btf, u32 func_id, |
|
struct bpf_reg_state *regs, |
|
bool ptr_to_mem_ok) |
|
{ |
|
struct bpf_verifier_log *log = &env->log; |
|
u32 i, nargs, ref_id, ref_obj_id = 0; |
|
bool is_kfunc = btf_is_kernel(btf); |
|
const char *func_name, *ref_tname; |
|
const struct btf_type *t, *ref_t; |
|
const struct btf_param *args; |
|
int ref_regno = 0, ret; |
|
bool rel = false; |
|
|
|
t = btf_type_by_id(btf, func_id); |
|
if (!t || !btf_type_is_func(t)) { |
|
/* These checks were already done by the verifier while loading |
|
* struct bpf_func_info or in add_kfunc_call(). |
|
*/ |
|
bpf_log(log, "BTF of func_id %u doesn't point to KIND_FUNC\n", |
|
func_id); |
|
return -EFAULT; |
|
} |
|
func_name = btf_name_by_offset(btf, t->name_off); |
|
|
|
t = btf_type_by_id(btf, t->type); |
|
if (!t || !btf_type_is_func_proto(t)) { |
|
bpf_log(log, "Invalid BTF of func %s\n", func_name); |
|
return -EFAULT; |
|
} |
|
args = (const struct btf_param *)(t + 1); |
|
nargs = btf_type_vlen(t); |
|
if (nargs > MAX_BPF_FUNC_REG_ARGS) { |
|
bpf_log(log, "Function %s has %d > %d args\n", func_name, nargs, |
|
MAX_BPF_FUNC_REG_ARGS); |
|
return -EINVAL; |
|
} |
|
|
|
/* Only kfunc can be release func */ |
|
if (is_kfunc) |
|
rel = btf_kfunc_id_set_contains(btf, resolve_prog_type(env->prog), |
|
BTF_KFUNC_TYPE_RELEASE, func_id); |
|
/* check that BTF function arguments match actual types that the |
|
* verifier sees. |
|
*/ |
|
for (i = 0; i < nargs; i++) { |
|
u32 regno = i + 1; |
|
struct bpf_reg_state *reg = ®s[regno]; |
|
|
|
t = btf_type_skip_modifiers(btf, args[i].type, NULL); |
|
if (btf_type_is_scalar(t)) { |
|
if (reg->type == SCALAR_VALUE) |
|
continue; |
|
bpf_log(log, "R%d is not a scalar\n", regno); |
|
return -EINVAL; |
|
} |
|
|
|
if (!btf_type_is_ptr(t)) { |
|
bpf_log(log, "Unrecognized arg#%d type %s\n", |
|
i, btf_type_str(t)); |
|
return -EINVAL; |
|
} |
|
|
|
ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id); |
|
ref_tname = btf_name_by_offset(btf, ref_t->name_off); |
|
|
|
ret = check_func_arg_reg_off(env, reg, regno, ARG_DONTCARE, rel); |
|
if (ret < 0) |
|
return ret; |
|
|
|
if (btf_get_prog_ctx_type(log, btf, t, |
|
env->prog->type, i)) { |
|
/* If function expects ctx type in BTF check that caller |
|
* is passing PTR_TO_CTX. |
|
*/ |
|
if (reg->type != PTR_TO_CTX) { |
|
bpf_log(log, |
|
"arg#%d expected pointer to ctx, but got %s\n", |
|
i, btf_type_str(t)); |
|
return -EINVAL; |
|
} |
|
} else if (is_kfunc && (reg->type == PTR_TO_BTF_ID || |
|
(reg2btf_ids[base_type(reg->type)] && !type_flag(reg->type)))) { |
|
const struct btf_type *reg_ref_t; |
|
const struct btf *reg_btf; |
|
const char *reg_ref_tname; |
|
u32 reg_ref_id; |
|
|
|
if (!btf_type_is_struct(ref_t)) { |
|
bpf_log(log, "kernel function %s args#%d pointer type %s %s is not supported\n", |
|
func_name, i, btf_type_str(ref_t), |
|
ref_tname); |
|
return -EINVAL; |
|
} |
|
|
|
if (reg->type == PTR_TO_BTF_ID) { |
|
reg_btf = reg->btf; |
|
reg_ref_id = reg->btf_id; |
|
/* Ensure only one argument is referenced |
|
* PTR_TO_BTF_ID, check_func_arg_reg_off relies |
|
* on only one referenced register being allowed |
|
* for kfuncs. |
|
*/ |
|
if (reg->ref_obj_id) { |
|
if (ref_obj_id) { |
|
bpf_log(log, "verifier internal error: more than one arg with ref_obj_id R%d %u %u\n", |
|
regno, reg->ref_obj_id, ref_obj_id); |
|
return -EFAULT; |
|
} |
|
ref_regno = regno; |
|
ref_obj_id = reg->ref_obj_id; |
|
} |
|
} else { |
|
reg_btf = btf_vmlinux; |
|
reg_ref_id = *reg2btf_ids[base_type(reg->type)]; |
|
} |
|
|
|
reg_ref_t = btf_type_skip_modifiers(reg_btf, reg_ref_id, |
|
®_ref_id); |
|
reg_ref_tname = btf_name_by_offset(reg_btf, |
|
reg_ref_t->name_off); |
|
if (!btf_struct_ids_match(log, reg_btf, reg_ref_id, |
|
reg->off, btf, ref_id)) { |
|
bpf_log(log, "kernel function %s args#%d expected pointer to %s %s but R%d has a pointer to %s %s\n", |
|
func_name, i, |
|
btf_type_str(ref_t), ref_tname, |
|
regno, btf_type_str(reg_ref_t), |
|
reg_ref_tname); |
|
return -EINVAL; |
|
} |
|
} else if (ptr_to_mem_ok) { |
|
const struct btf_type *resolve_ret; |
|
u32 type_size; |
|
|
|
if (is_kfunc) { |
|
bool arg_mem_size = i + 1 < nargs && is_kfunc_arg_mem_size(btf, &args[i + 1], ®s[regno + 1]); |
|
|
|
/* Permit pointer to mem, but only when argument |
|
* type is pointer to scalar, or struct composed |
|
* (recursively) of scalars. |
|
* When arg_mem_size is true, the pointer can be |
|
* void *. |
|
*/ |
|
if (!btf_type_is_scalar(ref_t) && |
|
!__btf_type_is_scalar_struct(log, btf, ref_t, 0) && |
|
(arg_mem_size ? !btf_type_is_void(ref_t) : 1)) { |
|
bpf_log(log, |
|
"arg#%d pointer type %s %s must point to %sscalar, or struct with scalar\n", |
|
i, btf_type_str(ref_t), ref_tname, arg_mem_size ? "void, " : ""); |
|
return -EINVAL; |
|
} |
|
|
|
/* Check for mem, len pair */ |
|
if (arg_mem_size) { |
|
if (check_kfunc_mem_size_reg(env, ®s[regno + 1], regno + 1)) { |
|
bpf_log(log, "arg#%d arg#%d memory, len pair leads to invalid memory access\n", |
|
i, i + 1); |
|
return -EINVAL; |
|
} |
|
i++; |
|
continue; |
|
} |
|
} |
|
|
|
resolve_ret = btf_resolve_size(btf, ref_t, &type_size); |
|
if (IS_ERR(resolve_ret)) { |
|
bpf_log(log, |
|
"arg#%d reference type('%s %s') size cannot be determined: %ld\n", |
|
i, btf_type_str(ref_t), ref_tname, |
|
PTR_ERR(resolve_ret)); |
|
return -EINVAL; |
|
} |
|
|
|
if (check_mem_reg(env, reg, regno, type_size)) |
|
return -EINVAL; |
|
} else { |
|
bpf_log(log, "reg type unsupported for arg#%d %sfunction %s#%d\n", i, |
|
is_kfunc ? "kernel " : "", func_name, func_id); |
|
return -EINVAL; |
|
} |
|
} |
|
|
|
/* Either both are set, or neither */ |
|
WARN_ON_ONCE((ref_obj_id && !ref_regno) || (!ref_obj_id && ref_regno)); |
|
/* We already made sure ref_obj_id is set only for one argument. We do |
|
* allow (!rel && ref_obj_id), so that passing such referenced |
|
* PTR_TO_BTF_ID to other kfuncs works. Note that rel is only true when |
|
* is_kfunc is true. |
|
*/ |
|
if (rel && !ref_obj_id) { |
|
bpf_log(log, "release kernel function %s expects refcounted PTR_TO_BTF_ID\n", |
|
func_name); |
|
return -EINVAL; |
|
} |
|
/* returns argument register number > 0 in case of reference release kfunc */ |
|
return rel ? ref_regno : 0; |
|
} |
|
|
|
/* Compare BTF of a function with given bpf_reg_state. |
|
* Returns: |
|
* EFAULT - there is a verifier bug. Abort verification. |
|
* EINVAL - there is a type mismatch or BTF is not available. |
|
* 0 - BTF matches with what bpf_reg_state expects. |
|
* Only PTR_TO_CTX and SCALAR_VALUE states are recognized. |
|
*/ |
|
int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog, |
|
struct bpf_reg_state *regs) |
|
{ |
|
struct bpf_prog *prog = env->prog; |
|
struct btf *btf = prog->aux->btf; |
|
bool is_global; |
|
u32 btf_id; |
|
int err; |
|
|
|
if (!prog->aux->func_info) |
|
return -EINVAL; |
|
|
|
btf_id = prog->aux->func_info[subprog].type_id; |
|
if (!btf_id) |
|
return -EFAULT; |
|
|
|
if (prog->aux->func_info_aux[subprog].unreliable) |
|
return -EINVAL; |
|
|
|
is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL; |
|
err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global); |
|
|
|
/* Compiler optimizations can remove arguments from static functions |
|
* or mismatched type can be passed into a global function. |
|
* In such cases mark the function as unreliable from BTF point of view. |
|
*/ |
|
if (err) |
|
prog->aux->func_info_aux[subprog].unreliable = true; |
|
return err; |
|
} |
|
|
|
int btf_check_kfunc_arg_match(struct bpf_verifier_env *env, |
|
const struct btf *btf, u32 func_id, |
|
struct bpf_reg_state *regs) |
|
{ |
|
return btf_check_func_arg_match(env, btf, func_id, regs, true); |
|
} |
|
|
|
/* Convert BTF of a function into bpf_reg_state if possible |
|
* Returns: |
|
* EFAULT - there is a verifier bug. Abort verification. |
|
* EINVAL - cannot convert BTF. |
|
* 0 - Successfully converted BTF into bpf_reg_state |
|
* (either PTR_TO_CTX or SCALAR_VALUE). |
|
*/ |
|
int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog, |
|
struct bpf_reg_state *regs) |
|
{ |
|
struct bpf_verifier_log *log = &env->log; |
|
struct bpf_prog *prog = env->prog; |
|
enum bpf_prog_type prog_type = prog->type; |
|
struct btf *btf = prog->aux->btf; |
|
const struct btf_param *args; |
|
const struct btf_type *t, *ref_t; |
|
u32 i, nargs, btf_id; |
|
const char *tname; |
|
|
|
if (!prog->aux->func_info || |
|
prog->aux->func_info_aux[subprog].linkage != BTF_FUNC_GLOBAL) { |
|
bpf_log(log, "Verifier bug\n"); |
|
return -EFAULT; |
|
} |
|
|
|
btf_id = prog->aux->func_info[subprog].type_id; |
|
if (!btf_id) { |
|
bpf_log(log, "Global functions need valid BTF\n"); |
|
return -EFAULT; |
|
} |
|
|
|
t = btf_type_by_id(btf, btf_id); |
|
if (!t || !btf_type_is_func(t)) { |
|
/* These checks were already done by the verifier while loading |
|
* struct bpf_func_info |
|
*/ |
|
bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n", |
|
subprog); |
|
return -EFAULT; |
|
} |
|
tname = btf_name_by_offset(btf, t->name_off); |
|
|
|
if (log->level & BPF_LOG_LEVEL) |
|
bpf_log(log, "Validating %s() func#%d...\n", |
|
tname, subprog); |
|
|
|
if (prog->aux->func_info_aux[subprog].unreliable) { |
|
bpf_log(log, "Verifier bug in function %s()\n", tname); |
|
return -EFAULT; |
|
} |
|
if (prog_type == BPF_PROG_TYPE_EXT) |
|
prog_type = prog->aux->dst_prog->type; |
|
|
|
t = btf_type_by_id(btf, t->type); |
|
if (!t || !btf_type_is_func_proto(t)) { |
|
bpf_log(log, "Invalid type of function %s()\n", tname); |
|
return -EFAULT; |
|
} |
|
args = (const struct btf_param *)(t + 1); |
|
nargs = btf_type_vlen(t); |
|
if (nargs > MAX_BPF_FUNC_REG_ARGS) { |
|
bpf_log(log, "Global function %s() with %d > %d args. Buggy compiler.\n", |
|
tname, nargs, MAX_BPF_FUNC_REG_ARGS); |
|
return -EINVAL; |
|
} |
|
/* check that function returns int */ |
|
t = btf_type_by_id(btf, t->type); |
|
while (btf_type_is_modifier(t)) |
|
t = btf_type_by_id(btf, t->type); |
|
if (!btf_type_is_int(t) && !btf_type_is_enum(t)) { |
|
bpf_log(log, |
|
"Global function %s() doesn't return scalar. Only those are supported.\n", |
|
tname); |
|
return -EINVAL; |
|
} |
|
/* Convert BTF function arguments into verifier types. |
|
* Only PTR_TO_CTX and SCALAR are supported atm. |
|
*/ |
|
for (i = 0; i < nargs; i++) { |
|
struct bpf_reg_state *reg = ®s[i + 1]; |
|
|
|
t = btf_type_by_id(btf, args[i].type); |
|
while (btf_type_is_modifier(t)) |
|
t = btf_type_by_id(btf, t->type); |
|
if (btf_type_is_int(t) || btf_type_is_enum(t)) { |
|
reg->type = SCALAR_VALUE; |
|
continue; |
|
} |
|
if (btf_type_is_ptr(t)) { |
|
if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) { |
|
reg->type = PTR_TO_CTX; |
|
continue; |
|
} |
|
|
|
t = btf_type_skip_modifiers(btf, t->type, NULL); |
|
|
|
ref_t = btf_resolve_size(btf, t, ®->mem_size); |
|
if (IS_ERR(ref_t)) { |
|
bpf_log(log, |
|
"arg#%d reference type('%s %s') size cannot be determined: %ld\n", |
|
i, btf_type_str(t), btf_name_by_offset(btf, t->name_off), |
|
PTR_ERR(ref_t)); |
|
return -EINVAL; |
|
} |
|
|
|
reg->type = PTR_TO_MEM | PTR_MAYBE_NULL; |
|
reg->id = ++env->id_gen; |
|
|
|
continue; |
|
} |
|
bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n", |
|
i, btf_kind_str[BTF_INFO_KIND(t->info)], tname); |
|
return -EINVAL; |
|
} |
|
return 0; |
|
} |
|
|
|
static void btf_type_show(const struct btf *btf, u32 type_id, void *obj, |
|
struct btf_show *show) |
|
{ |
|
const struct btf_type *t = btf_type_by_id(btf, type_id); |
|
|
|
show->btf = btf; |
|
memset(&show->state, 0, sizeof(show->state)); |
|
memset(&show->obj, 0, sizeof(show->obj)); |
|
|
|
btf_type_ops(t)->show(btf, t, type_id, obj, 0, show); |
|
} |
|
|
|
static void btf_seq_show(struct btf_show *show, const char *fmt, |
|
va_list args) |
|
{ |
|
seq_vprintf((struct seq_file *)show->target, fmt, args); |
|
} |
|
|
|
int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, |
|
void *obj, struct seq_file *m, u64 flags) |
|
{ |
|
struct btf_show sseq; |
|
|
|
sseq.target = m; |
|
sseq.showfn = btf_seq_show; |
|
sseq.flags = flags; |
|
|
|
btf_type_show(btf, type_id, obj, &sseq); |
|
|
|
return sseq.state.status; |
|
} |
|
|
|
void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, |
|
struct seq_file *m) |
|
{ |
|
(void) btf_type_seq_show_flags(btf, type_id, obj, m, |
|
BTF_SHOW_NONAME | BTF_SHOW_COMPACT | |
|
BTF_SHOW_ZERO | BTF_SHOW_UNSAFE); |
|
} |
|
|
|
struct btf_show_snprintf { |
|
struct btf_show show; |
|
int len_left; /* space left in string */ |
|
int len; /* length we would have written */ |
|
}; |
|
|
|
static void btf_snprintf_show(struct btf_show *show, const char *fmt, |
|
va_list args) |
|
{ |
|
struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show; |
|
int len; |
|
|
|
len = vsnprintf(show->target, ssnprintf->len_left, fmt, args); |
|
|
|
if (len < 0) { |
|
ssnprintf->len_left = 0; |
|
ssnprintf->len = len; |
|
} else if (len > ssnprintf->len_left) { |
|
/* no space, drive on to get length we would have written */ |
|
ssnprintf->len_left = 0; |
|
ssnprintf->len += len; |
|
} else { |
|
ssnprintf->len_left -= len; |
|
ssnprintf->len += len; |
|
show->target += len; |
|
} |
|
} |
|
|
|
int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj, |
|
char *buf, int len, u64 flags) |
|
{ |
|
struct btf_show_snprintf ssnprintf; |
|
|
|
ssnprintf.show.target = buf; |
|
ssnprintf.show.flags = flags; |
|
ssnprintf.show.showfn = btf_snprintf_show; |
|
ssnprintf.len_left = len; |
|
ssnprintf.len = 0; |
|
|
|
btf_type_show(btf, type_id, obj, (struct btf_show *)&ssnprintf); |
|
|
|
/* If we encountered an error, return it. */ |
|
if (ssnprintf.show.state.status) |
|
return ssnprintf.show.state.status; |
|
|
|
/* Otherwise return length we would have written */ |
|
return ssnprintf.len; |
|
} |
|
|
|
#ifdef CONFIG_PROC_FS |
|
static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp) |
|
{ |
|
const struct btf *btf = filp->private_data; |
|
|
|
seq_printf(m, "btf_id:\t%u\n", btf->id); |
|
} |
|
#endif |
|
|
|
static int btf_release(struct inode *inode, struct file *filp) |
|
{ |
|
btf_put(filp->private_data); |
|
return 0; |
|
} |
|
|
|
const struct file_operations btf_fops = { |
|
#ifdef CONFIG_PROC_FS |
|
.show_fdinfo = bpf_btf_show_fdinfo, |
|
#endif |
|
.release = btf_release, |
|
}; |
|
|
|
static int __btf_new_fd(struct btf *btf) |
|
{ |
|
return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC); |
|
} |
|
|
|
int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr) |
|
{ |
|
struct btf *btf; |
|
int ret; |
|
|
|
btf = btf_parse(make_bpfptr(attr->btf, uattr.is_kernel), |
|
attr->btf_size, attr->btf_log_level, |
|
u64_to_user_ptr(attr->btf_log_buf), |
|
attr->btf_log_size); |
|
if (IS_ERR(btf)) |
|
return PTR_ERR(btf); |
|
|
|
ret = btf_alloc_id(btf); |
|
if (ret) { |
|
btf_free(btf); |
|
return ret; |
|
} |
|
|
|
/* |
|
* The BTF ID is published to the userspace. |
|
* All BTF free must go through call_rcu() from |
|
* now on (i.e. free by calling btf_put()). |
|
*/ |
|
|
|
ret = __btf_new_fd(btf); |
|
if (ret < 0) |
|
btf_put(btf); |
|
|
|
return ret; |
|
} |
|
|
|
struct btf *btf_get_by_fd(int fd) |
|
{ |
|
struct btf *btf; |
|
struct fd f; |
|
|
|
f = fdget(fd); |
|
|
|
if (!f.file) |
|
return ERR_PTR(-EBADF); |
|
|
|
if (f.file->f_op != &btf_fops) { |
|
fdput(f); |
|
return ERR_PTR(-EINVAL); |
|
} |
|
|
|
btf = f.file->private_data; |
|
refcount_inc(&btf->refcnt); |
|
fdput(f); |
|
|
|
return btf; |
|
} |
|
|
|
int btf_get_info_by_fd(const struct btf *btf, |
|
const union bpf_attr *attr, |
|
union bpf_attr __user *uattr) |
|
{ |
|
struct bpf_btf_info __user *uinfo; |
|
struct bpf_btf_info info; |
|
u32 info_copy, btf_copy; |
|
void __user *ubtf; |
|
char __user *uname; |
|
u32 uinfo_len, uname_len, name_len; |
|
int ret = 0; |
|
|
|
uinfo = u64_to_user_ptr(attr->info.info); |
|
uinfo_len = attr->info.info_len; |
|
|
|
info_copy = min_t(u32, uinfo_len, sizeof(info)); |
|
memset(&info, 0, sizeof(info)); |
|
if (copy_from_user(&info, uinfo, info_copy)) |
|
return -EFAULT; |
|
|
|
info.id = btf->id; |
|
ubtf = u64_to_user_ptr(info.btf); |
|
btf_copy = min_t(u32, btf->data_size, info.btf_size); |
|
if (copy_to_user(ubtf, btf->data, btf_copy)) |
|
return -EFAULT; |
|
info.btf_size = btf->data_size; |
|
|
|
info.kernel_btf = btf->kernel_btf; |
|
|
|
uname = u64_to_user_ptr(info.name); |
|
uname_len = info.name_len; |
|
if (!uname ^ !uname_len) |
|
return -EINVAL; |
|
|
|
name_len = strlen(btf->name); |
|
info.name_len = name_len; |
|
|
|
if (uname) { |
|
if (uname_len >= name_len + 1) { |
|
if (copy_to_user(uname, btf->name, name_len + 1)) |
|
return -EFAULT; |
|
} else { |
|
char zero = '\0'; |
|
|
|
if (copy_to_user(uname, btf->name, uname_len - 1)) |
|
return -EFAULT; |
|
if (put_user(zero, uname + uname_len - 1)) |
|
return -EFAULT; |
|
/* let user-space know about too short buffer */ |
|
ret = -ENOSPC; |
|
} |
|
} |
|
|
|
if (copy_to_user(uinfo, &info, info_copy) || |
|
put_user(info_copy, &uattr->info.info_len)) |
|
return -EFAULT; |
|
|
|
return ret; |
|
} |
|
|
|
int btf_get_fd_by_id(u32 id) |
|
{ |
|
struct btf *btf; |
|
int fd; |
|
|
|
rcu_read_lock(); |
|
btf = idr_find(&btf_idr, id); |
|
if (!btf || !refcount_inc_not_zero(&btf->refcnt)) |
|
btf = ERR_PTR(-ENOENT); |
|
rcu_read_unlock(); |
|
|
|
if (IS_ERR(btf)) |
|
return PTR_ERR(btf); |
|
|
|
fd = __btf_new_fd(btf); |
|
if (fd < 0) |
|
btf_put(btf); |
|
|
|
return fd; |
|
} |
|
|
|
u32 btf_obj_id(const struct btf *btf) |
|
{ |
|
return btf->id; |
|
} |
|
|
|
bool btf_is_kernel(const struct btf *btf) |
|
{ |
|
return btf->kernel_btf; |
|
} |
|
|
|
bool btf_is_module(const struct btf *btf) |
|
{ |
|
return btf->kernel_btf && strcmp(btf->name, "vmlinux") != 0; |
|
} |
|
|
|
static int btf_id_cmp_func(const void *a, const void *b) |
|
{ |
|
const int *pa = a, *pb = b; |
|
|
|
return *pa - *pb; |
|
} |
|
|
|
bool btf_id_set_contains(const struct btf_id_set *set, u32 id) |
|
{ |
|
return bsearch(&id, set->ids, set->cnt, sizeof(u32), btf_id_cmp_func) != NULL; |
|
} |
|
|
|
enum { |
|
BTF_MODULE_F_LIVE = (1 << 0), |
|
}; |
|
|
|
#ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
|
struct btf_module { |
|
struct list_head list; |
|
struct module *module; |
|
struct btf *btf; |
|
struct bin_attribute *sysfs_attr; |
|
int flags; |
|
}; |
|
|
|
static LIST_HEAD(btf_modules); |
|
static DEFINE_MUTEX(btf_module_mutex); |
|
|
|
static ssize_t |
|
btf_module_read(struct file *file, struct kobject *kobj, |
|
struct bin_attribute *bin_attr, |
|
char *buf, loff_t off, size_t len) |
|
{ |
|
const struct btf *btf = bin_attr->private; |
|
|
|
memcpy(buf, btf->data + off, len); |
|
return len; |
|
} |
|
|
|
static void purge_cand_cache(struct btf *btf); |
|
|
|
static int btf_module_notify(struct notifier_block *nb, unsigned long op, |
|
void *module) |
|
{ |
|
struct btf_module *btf_mod, *tmp; |
|
struct module *mod = module; |
|
struct btf *btf; |
|
int err = 0; |
|
|
|
if (mod->btf_data_size == 0 || |
|
(op != MODULE_STATE_COMING && op != MODULE_STATE_LIVE && |
|
op != MODULE_STATE_GOING)) |
|
goto out; |
|
|
|
switch (op) { |
|
case MODULE_STATE_COMING: |
|
btf_mod = kzalloc(sizeof(*btf_mod), GFP_KERNEL); |
|
if (!btf_mod) { |
|
err = -ENOMEM; |
|
goto out; |
|
} |
|
btf = btf_parse_module(mod->name, mod->btf_data, mod->btf_data_size); |
|
if (IS_ERR(btf)) { |
|
pr_warn("failed to validate module [%s] BTF: %ld\n", |
|
mod->name, PTR_ERR(btf)); |
|
kfree(btf_mod); |
|
if (!IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) |
|
err = PTR_ERR(btf); |
|
goto out; |
|
} |
|
err = btf_alloc_id(btf); |
|
if (err) { |
|
btf_free(btf); |
|
kfree(btf_mod); |
|
goto out; |
|
} |
|
|
|
purge_cand_cache(NULL); |
|
mutex_lock(&btf_module_mutex); |
|
btf_mod->module = module; |
|
btf_mod->btf = btf; |
|
list_add(&btf_mod->list, &btf_modules); |
|
mutex_unlock(&btf_module_mutex); |
|
|
|
if (IS_ENABLED(CONFIG_SYSFS)) { |
|
struct bin_attribute *attr; |
|
|
|
attr = kzalloc(sizeof(*attr), GFP_KERNEL); |
|
if (!attr) |
|
goto out; |
|
|
|
sysfs_bin_attr_init(attr); |
|
attr->attr.name = btf->name; |
|
attr->attr.mode = 0444; |
|
attr->size = btf->data_size; |
|
attr->private = btf; |
|
attr->read = btf_module_read; |
|
|
|
err = sysfs_create_bin_file(btf_kobj, attr); |
|
if (err) { |
|
pr_warn("failed to register module [%s] BTF in sysfs: %d\n", |
|
mod->name, err); |
|
kfree(attr); |
|
err = 0; |
|
goto out; |
|
} |
|
|
|
btf_mod->sysfs_attr = attr; |
|
} |
|
|
|
break; |
|
case MODULE_STATE_LIVE: |
|
mutex_lock(&btf_module_mutex); |
|
list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { |
|
if (btf_mod->module != module) |
|
continue; |
|
|
|
btf_mod->flags |= BTF_MODULE_F_LIVE; |
|
break; |
|
} |
|
mutex_unlock(&btf_module_mutex); |
|
break; |
|
case MODULE_STATE_GOING: |
|
mutex_lock(&btf_module_mutex); |
|
list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { |
|
if (btf_mod->module != module) |
|
continue; |
|
|
|
list_del(&btf_mod->list); |
|
if (btf_mod->sysfs_attr) |
|
sysfs_remove_bin_file(btf_kobj, btf_mod->sysfs_attr); |
|
purge_cand_cache(btf_mod->btf); |
|
btf_put(btf_mod->btf); |
|
kfree(btf_mod->sysfs_attr); |
|
kfree(btf_mod); |
|
break; |
|
} |
|
mutex_unlock(&btf_module_mutex); |
|
break; |
|
} |
|
out: |
|
return notifier_from_errno(err); |
|
} |
|
|
|
static struct notifier_block btf_module_nb = { |
|
.notifier_call = btf_module_notify, |
|
}; |
|
|
|
static int __init btf_module_init(void) |
|
{ |
|
register_module_notifier(&btf_module_nb); |
|
return 0; |
|
} |
|
|
|
fs_initcall(btf_module_init); |
|
#endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ |
|
|
|
struct module *btf_try_get_module(const struct btf *btf) |
|
{ |
|
struct module *res = NULL; |
|
#ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
|
struct btf_module *btf_mod, *tmp; |
|
|
|
mutex_lock(&btf_module_mutex); |
|
list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { |
|
if (btf_mod->btf != btf) |
|
continue; |
|
|
|
/* We must only consider module whose __init routine has |
|
* finished, hence we must check for BTF_MODULE_F_LIVE flag, |
|
* which is set from the notifier callback for |
|
* MODULE_STATE_LIVE. |
|
*/ |
|
if ((btf_mod->flags & BTF_MODULE_F_LIVE) && try_module_get(btf_mod->module)) |
|
res = btf_mod->module; |
|
|
|
break; |
|
} |
|
mutex_unlock(&btf_module_mutex); |
|
#endif |
|
|
|
return res; |
|
} |
|
|
|
/* Returns struct btf corresponding to the struct module. |
|
* This function can return NULL or ERR_PTR. |
|
*/ |
|
static struct btf *btf_get_module_btf(const struct module *module) |
|
{ |
|
#ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
|
struct btf_module *btf_mod, *tmp; |
|
#endif |
|
struct btf *btf = NULL; |
|
|
|
if (!module) { |
|
btf = bpf_get_btf_vmlinux(); |
|
if (!IS_ERR_OR_NULL(btf)) |
|
btf_get(btf); |
|
return btf; |
|
} |
|
|
|
#ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
|
mutex_lock(&btf_module_mutex); |
|
list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { |
|
if (btf_mod->module != module) |
|
continue; |
|
|
|
btf_get(btf_mod->btf); |
|
btf = btf_mod->btf; |
|
break; |
|
} |
|
mutex_unlock(&btf_module_mutex); |
|
#endif |
|
|
|
return btf; |
|
} |
|
|
|
BPF_CALL_4(bpf_btf_find_by_name_kind, char *, name, int, name_sz, u32, kind, int, flags) |
|
{ |
|
struct btf *btf = NULL; |
|
int btf_obj_fd = 0; |
|
long ret; |
|
|
|
if (flags) |
|
return -EINVAL; |
|
|
|
if (name_sz <= 1 || name[name_sz - 1]) |
|
return -EINVAL; |
|
|
|
ret = bpf_find_btf_id(name, kind, &btf); |
|
if (ret > 0 && btf_is_module(btf)) { |
|
btf_obj_fd = __btf_new_fd(btf); |
|
if (btf_obj_fd < 0) { |
|
btf_put(btf); |
|
return btf_obj_fd; |
|
} |
|
return ret | (((u64)btf_obj_fd) << 32); |
|
} |
|
if (ret > 0) |
|
btf_put(btf); |
|
return ret; |
|
} |
|
|
|
const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = { |
|
.func = bpf_btf_find_by_name_kind, |
|
.gpl_only = false, |
|
.ret_type = RET_INTEGER, |
|
.arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
|
.arg2_type = ARG_CONST_SIZE, |
|
.arg3_type = ARG_ANYTHING, |
|
.arg4_type = ARG_ANYTHING, |
|
}; |
|
|
|
BTF_ID_LIST_GLOBAL(btf_tracing_ids, MAX_BTF_TRACING_TYPE) |
|
#define BTF_TRACING_TYPE(name, type) BTF_ID(struct, type) |
|
BTF_TRACING_TYPE_xxx |
|
#undef BTF_TRACING_TYPE |
|
|
|
/* Kernel Function (kfunc) BTF ID set registration API */ |
|
|
|
static int __btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, |
|
enum btf_kfunc_type type, |
|
struct btf_id_set *add_set, bool vmlinux_set) |
|
{ |
|
struct btf_kfunc_set_tab *tab; |
|
struct btf_id_set *set; |
|
u32 set_cnt; |
|
int ret; |
|
|
|
if (hook >= BTF_KFUNC_HOOK_MAX || type >= BTF_KFUNC_TYPE_MAX) { |
|
ret = -EINVAL; |
|
goto end; |
|
} |
|
|
|
if (!add_set->cnt) |
|
return 0; |
|
|
|
tab = btf->kfunc_set_tab; |
|
if (!tab) { |
|
tab = kzalloc(sizeof(*tab), GFP_KERNEL | __GFP_NOWARN); |
|
if (!tab) |
|
return -ENOMEM; |
|
btf->kfunc_set_tab = tab; |
|
} |
|
|
|
set = tab->sets[hook][type]; |
|
/* Warn when register_btf_kfunc_id_set is called twice for the same hook |
|
* for module sets. |
|
*/ |
|
if (WARN_ON_ONCE(set && !vmlinux_set)) { |
|
ret = -EINVAL; |
|
goto end; |
|
} |
|
|
|
/* We don't need to allocate, concatenate, and sort module sets, because |
|
* only one is allowed per hook. Hence, we can directly assign the |
|
* pointer and return. |
|
*/ |
|
if (!vmlinux_set) { |
|
tab->sets[hook][type] = add_set; |
|
return 0; |
|
} |
|
|
|
/* In case of vmlinux sets, there may be more than one set being |
|
* registered per hook. To create a unified set, we allocate a new set |
|
* and concatenate all individual sets being registered. While each set |
|
* is individually sorted, they may become unsorted when concatenated, |
|
* hence re-sorting the final set again is required to make binary |
|
* searching the set using btf_id_set_contains function work. |
|
*/ |
|
set_cnt = set ? set->cnt : 0; |
|
|
|
if (set_cnt > U32_MAX - add_set->cnt) { |
|
ret = -EOVERFLOW; |
|
goto end; |
|
} |
|
|
|
if (set_cnt + add_set->cnt > BTF_KFUNC_SET_MAX_CNT) { |
|
ret = -E2BIG; |
|
goto end; |
|
} |
|
|
|
/* Grow set */ |
|
set = krealloc(tab->sets[hook][type], |
|
offsetof(struct btf_id_set, ids[set_cnt + add_set->cnt]), |
|
GFP_KERNEL | __GFP_NOWARN); |
|
if (!set) { |
|
ret = -ENOMEM; |
|
goto end; |
|
} |
|
|
|
/* For newly allocated set, initialize set->cnt to 0 */ |
|
if (!tab->sets[hook][type]) |
|
set->cnt = 0; |
|
tab->sets[hook][type] = set; |
|
|
|
/* Concatenate the two sets */ |
|
memcpy(set->ids + set->cnt, add_set->ids, add_set->cnt * sizeof(set->ids[0])); |
|
set->cnt += add_set->cnt; |
|
|
|
sort(set->ids, set->cnt, sizeof(set->ids[0]), btf_id_cmp_func, NULL); |
|
|
|
return 0; |
|
end: |
|
btf_free_kfunc_set_tab(btf); |
|
return ret; |
|
} |
|
|
|
static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, |
|
const struct btf_kfunc_id_set *kset) |
|
{ |
|
bool vmlinux_set = !btf_is_module(btf); |
|
int type, ret = 0; |
|
|
|
for (type = 0; type < ARRAY_SIZE(kset->sets); type++) { |
|
if (!kset->sets[type]) |
|
continue; |
|
|
|
ret = __btf_populate_kfunc_set(btf, hook, type, kset->sets[type], vmlinux_set); |
|
if (ret) |
|
break; |
|
} |
|
return ret; |
|
} |
|
|
|
static bool __btf_kfunc_id_set_contains(const struct btf *btf, |
|
enum btf_kfunc_hook hook, |
|
enum btf_kfunc_type type, |
|
u32 kfunc_btf_id) |
|
{ |
|
struct btf_id_set *set; |
|
|
|
if (hook >= BTF_KFUNC_HOOK_MAX || type >= BTF_KFUNC_TYPE_MAX) |
|
return false; |
|
if (!btf->kfunc_set_tab) |
|
return false; |
|
set = btf->kfunc_set_tab->sets[hook][type]; |
|
if (!set) |
|
return false; |
|
return btf_id_set_contains(set, kfunc_btf_id); |
|
} |
|
|
|
static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) |
|
{ |
|
switch (prog_type) { |
|
case BPF_PROG_TYPE_XDP: |
|
return BTF_KFUNC_HOOK_XDP; |
|
case BPF_PROG_TYPE_SCHED_CLS: |
|
return BTF_KFUNC_HOOK_TC; |
|
case BPF_PROG_TYPE_STRUCT_OPS: |
|
return BTF_KFUNC_HOOK_STRUCT_OPS; |
|
default: |
|
return BTF_KFUNC_HOOK_MAX; |
|
} |
|
} |
|
|
|
/* Caution: |
|
* Reference to the module (obtained using btf_try_get_module) corresponding to |
|
* the struct btf *MUST* be held when calling this function from verifier |
|
* context. This is usually true as we stash references in prog's kfunc_btf_tab; |
|
* keeping the reference for the duration of the call provides the necessary |
|
* protection for looking up a well-formed btf->kfunc_set_tab. |
|
*/ |
|
bool btf_kfunc_id_set_contains(const struct btf *btf, |
|
enum bpf_prog_type prog_type, |
|
enum btf_kfunc_type type, u32 kfunc_btf_id) |
|
{ |
|
enum btf_kfunc_hook hook; |
|
|
|
hook = bpf_prog_type_to_kfunc_hook(prog_type); |
|
return __btf_kfunc_id_set_contains(btf, hook, type, kfunc_btf_id); |
|
} |
|
|
|
/* This function must be invoked only from initcalls/module init functions */ |
|
int register_btf_kfunc_id_set(enum bpf_prog_type prog_type, |
|
const struct btf_kfunc_id_set *kset) |
|
{ |
|
enum btf_kfunc_hook hook; |
|
struct btf *btf; |
|
int ret; |
|
|
|
btf = btf_get_module_btf(kset->owner); |
|
if (!btf) { |
|
if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) { |
|
pr_err("missing vmlinux BTF, cannot register kfuncs\n"); |
|
return -ENOENT; |
|
} |
|
if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) { |
|
pr_err("missing module BTF, cannot register kfuncs\n"); |
|
return -ENOENT; |
|
} |
|
return 0; |
|
} |
|
if (IS_ERR(btf)) |
|
return PTR_ERR(btf); |
|
|
|
hook = bpf_prog_type_to_kfunc_hook(prog_type); |
|
ret = btf_populate_kfunc_set(btf, hook, kset); |
|
btf_put(btf); |
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(register_btf_kfunc_id_set); |
|
|
|
#define MAX_TYPES_ARE_COMPAT_DEPTH 2 |
|
|
|
static |
|
int __bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, |
|
const struct btf *targ_btf, __u32 targ_id, |
|
int level) |
|
{ |
|
const struct btf_type *local_type, *targ_type; |
|
int depth = 32; /* max recursion depth */ |
|
|
|
/* caller made sure that names match (ignoring flavor suffix) */ |
|
local_type = btf_type_by_id(local_btf, local_id); |
|
targ_type = btf_type_by_id(targ_btf, targ_id); |
|
if (btf_kind(local_type) != btf_kind(targ_type)) |
|
return 0; |
|
|
|
recur: |
|
depth--; |
|
if (depth < 0) |
|
return -EINVAL; |
|
|
|
local_type = btf_type_skip_modifiers(local_btf, local_id, &local_id); |
|
targ_type = btf_type_skip_modifiers(targ_btf, targ_id, &targ_id); |
|
if (!local_type || !targ_type) |
|
return -EINVAL; |
|
|
|
if (btf_kind(local_type) != btf_kind(targ_type)) |
|
return 0; |
|
|
|
switch (btf_kind(local_type)) { |
|
case BTF_KIND_UNKN: |
|
case BTF_KIND_STRUCT: |
|
case BTF_KIND_UNION: |
|
case BTF_KIND_ENUM: |
|
case BTF_KIND_FWD: |
|
return 1; |
|
case BTF_KIND_INT: |
|
/* just reject deprecated bitfield-like integers; all other |
|
* integers are by default compatible between each other |
|
*/ |
|
return btf_int_offset(local_type) == 0 && btf_int_offset(targ_type) == 0; |
|
case BTF_KIND_PTR: |
|
local_id = local_type->type; |
|
targ_id = targ_type->type; |
|
goto recur; |
|
case BTF_KIND_ARRAY: |
|
local_id = btf_array(local_type)->type; |
|
targ_id = btf_array(targ_type)->type; |
|
goto recur; |
|
case BTF_KIND_FUNC_PROTO: { |
|
struct btf_param *local_p = btf_params(local_type); |
|
struct btf_param *targ_p = btf_params(targ_type); |
|
__u16 local_vlen = btf_vlen(local_type); |
|
__u16 targ_vlen = btf_vlen(targ_type); |
|
int i, err; |
|
|
|
if (local_vlen != targ_vlen) |
|
return 0; |
|
|
|
for (i = 0; i < local_vlen; i++, local_p++, targ_p++) { |
|
if (level <= 0) |
|
return -EINVAL; |
|
|
|
btf_type_skip_modifiers(local_btf, local_p->type, &local_id); |
|
btf_type_skip_modifiers(targ_btf, targ_p->type, &targ_id); |
|
err = __bpf_core_types_are_compat(local_btf, local_id, |
|
targ_btf, targ_id, |
|
level - 1); |
|
if (err <= 0) |
|
return err; |
|
} |
|
|
|
/* tail recurse for return type check */ |
|
btf_type_skip_modifiers(local_btf, local_type->type, &local_id); |
|
btf_type_skip_modifiers(targ_btf, targ_type->type, &targ_id); |
|
goto recur; |
|
} |
|
default: |
|
return 0; |
|
} |
|
} |
|
|
|
/* Check local and target types for compatibility. This check is used for |
|
* type-based CO-RE relocations and follow slightly different rules than |
|
* field-based relocations. This function assumes that root types were already |
|
* checked for name match. Beyond that initial root-level name check, names |
|
* are completely ignored. Compatibility rules are as follows: |
|
* - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs are considered compatible, but |
|
* kind should match for local and target types (i.e., STRUCT is not |
|
* compatible with UNION); |
|
* - for ENUMs, the size is ignored; |
|
* - for INT, size and signedness are ignored; |
|
* - for ARRAY, dimensionality is ignored, element types are checked for |
|
* compatibility recursively; |
|
* - CONST/VOLATILE/RESTRICT modifiers are ignored; |
|
* - TYPEDEFs/PTRs are compatible if types they pointing to are compatible; |
|
* - FUNC_PROTOs are compatible if they have compatible signature: same |
|
* number of input args and compatible return and argument types. |
|
* These rules are not set in stone and probably will be adjusted as we get |
|
* more experience with using BPF CO-RE relocations. |
|
*/ |
|
int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, |
|
const struct btf *targ_btf, __u32 targ_id) |
|
{ |
|
return __bpf_core_types_are_compat(local_btf, local_id, |
|
targ_btf, targ_id, |
|
MAX_TYPES_ARE_COMPAT_DEPTH); |
|
} |
|
|
|
static bool bpf_core_is_flavor_sep(const char *s) |
|
{ |
|
/* check X___Y name pattern, where X and Y are not underscores */ |
|
return s[0] != '_' && /* X */ |
|
s[1] == '_' && s[2] == '_' && s[3] == '_' && /* ___ */ |
|
s[4] != '_'; /* Y */ |
|
} |
|
|
|
size_t bpf_core_essential_name_len(const char *name) |
|
{ |
|
size_t n = strlen(name); |
|
int i; |
|
|
|
for (i = n - 5; i >= 0; i--) { |
|
if (bpf_core_is_flavor_sep(name + i)) |
|
return i + 1; |
|
} |
|
return n; |
|
} |
|
|
|
struct bpf_cand_cache { |
|
const char *name; |
|
u32 name_len; |
|
u16 kind; |
|
u16 cnt; |
|
struct { |
|
const struct btf *btf; |
|
u32 id; |
|
} cands[]; |
|
}; |
|
|
|
static void bpf_free_cands(struct bpf_cand_cache *cands) |
|
{ |
|
if (!cands->cnt) |
|
/* empty candidate array was allocated on stack */ |
|
return; |
|
kfree(cands); |
|
} |
|
|
|
static void bpf_free_cands_from_cache(struct bpf_cand_cache *cands) |
|
{ |
|
kfree(cands->name); |
|
kfree(cands); |
|
} |
|
|
|
#define VMLINUX_CAND_CACHE_SIZE 31 |
|
static struct bpf_cand_cache *vmlinux_cand_cache[VMLINUX_CAND_CACHE_SIZE]; |
|
|
|
#define MODULE_CAND_CACHE_SIZE 31 |
|
static struct bpf_cand_cache *module_cand_cache[MODULE_CAND_CACHE_SIZE]; |
|
|
|
static DEFINE_MUTEX(cand_cache_mutex); |
|
|
|
static void __print_cand_cache(struct bpf_verifier_log *log, |
|
struct bpf_cand_cache **cache, |
|
int cache_size) |
|
{ |
|
struct bpf_cand_cache *cc; |
|
int i, j; |
|
|
|
for (i = 0; i < cache_size; i++) { |
|
cc = cache[i]; |
|
if (!cc) |
|
continue; |
|
bpf_log(log, "[%d]%s(", i, cc->name); |
|
for (j = 0; j < cc->cnt; j++) { |
|
bpf_log(log, "%d", cc->cands[j].id); |
|
if (j < cc->cnt - 1) |
|
bpf_log(log, " "); |
|
} |
|
bpf_log(log, "), "); |
|
} |
|
} |
|
|
|
static void print_cand_cache(struct bpf_verifier_log *log) |
|
{ |
|
mutex_lock(&cand_cache_mutex); |
|
bpf_log(log, "vmlinux_cand_cache:"); |
|
__print_cand_cache(log, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); |
|
bpf_log(log, "\nmodule_cand_cache:"); |
|
__print_cand_cache(log, module_cand_cache, MODULE_CAND_CACHE_SIZE); |
|
bpf_log(log, "\n"); |
|
mutex_unlock(&cand_cache_mutex); |
|
} |
|
|
|
static u32 hash_cands(struct bpf_cand_cache *cands) |
|
{ |
|
return jhash(cands->name, cands->name_len, 0); |
|
} |
|
|
|
static struct bpf_cand_cache *check_cand_cache(struct bpf_cand_cache *cands, |
|
struct bpf_cand_cache **cache, |
|
int cache_size) |
|
{ |
|
struct bpf_cand_cache *cc = cache[hash_cands(cands) % cache_size]; |
|
|
|
if (cc && cc->name_len == cands->name_len && |
|
!strncmp(cc->name, cands->name, cands->name_len)) |
|
return cc; |
|
return NULL; |
|
} |
|
|
|
static size_t sizeof_cands(int cnt) |
|
{ |
|
return offsetof(struct bpf_cand_cache, cands[cnt]); |
|
} |
|
|
|
static struct bpf_cand_cache *populate_cand_cache(struct bpf_cand_cache *cands, |
|
struct bpf_cand_cache **cache, |
|
int cache_size) |
|
{ |
|
struct bpf_cand_cache **cc = &cache[hash_cands(cands) % cache_size], *new_cands; |
|
|
|
if (*cc) { |
|
bpf_free_cands_from_cache(*cc); |
|
*cc = NULL; |
|
} |
|
new_cands = kmemdup(cands, sizeof_cands(cands->cnt), GFP_KERNEL); |
|
if (!new_cands) { |
|
bpf_free_cands(cands); |
|
return ERR_PTR(-ENOMEM); |
|
} |
|
/* strdup the name, since it will stay in cache. |
|
* the cands->name points to strings in prog's BTF and the prog can be unloaded. |
|
*/ |
|
new_cands->name = kmemdup_nul(cands->name, cands->name_len, GFP_KERNEL); |
|
bpf_free_cands(cands); |
|
if (!new_cands->name) { |
|
kfree(new_cands); |
|
return ERR_PTR(-ENOMEM); |
|
} |
|
*cc = new_cands; |
|
return new_cands; |
|
} |
|
|
|
#ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
|
static void __purge_cand_cache(struct btf *btf, struct bpf_cand_cache **cache, |
|
int cache_size) |
|
{ |
|
struct bpf_cand_cache *cc; |
|
int i, j; |
|
|
|
for (i = 0; i < cache_size; i++) { |
|
cc = cache[i]; |
|
if (!cc) |
|
continue; |
|
if (!btf) { |
|
/* when new module is loaded purge all of module_cand_cache, |
|
* since new module might have candidates with the name |
|
* that matches cached cands. |
|
*/ |
|
bpf_free_cands_from_cache(cc); |
|
cache[i] = NULL; |
|
continue; |
|
} |
|
/* when module is unloaded purge cache entries |
|
* that match module's btf |
|
*/ |
|
for (j = 0; j < cc->cnt; j++) |
|
if (cc->cands[j].btf == btf) { |
|
bpf_free_cands_from_cache(cc); |
|
cache[i] = NULL; |
|
break; |
|
} |
|
} |
|
|
|
} |
|
|
|
static void purge_cand_cache(struct btf *btf) |
|
{ |
|
mutex_lock(&cand_cache_mutex); |
|
__purge_cand_cache(btf, module_cand_cache, MODULE_CAND_CACHE_SIZE); |
|
mutex_unlock(&cand_cache_mutex); |
|
} |
|
#endif |
|
|
|
static struct bpf_cand_cache * |
|
bpf_core_add_cands(struct bpf_cand_cache *cands, const struct btf *targ_btf, |
|
int targ_start_id) |
|
{ |
|
struct bpf_cand_cache *new_cands; |
|
const struct btf_type *t; |
|
const char *targ_name; |
|
size_t targ_essent_len; |
|
int n, i; |
|
|
|
n = btf_nr_types(targ_btf); |
|
for (i = targ_start_id; i < n; i++) { |
|
t = btf_type_by_id(targ_btf, i); |
|
if (btf_kind(t) != cands->kind) |
|
continue; |
|
|
|
targ_name = btf_name_by_offset(targ_btf, t->name_off); |
|
if (!targ_name) |
|
continue; |
|
|
|
/* the resched point is before strncmp to make sure that search |
|
* for non-existing name will have a chance to schedule(). |
|
*/ |
|
cond_resched(); |
|
|
|
if (strncmp(cands->name, targ_name, cands->name_len) != 0) |
|
continue; |
|
|
|
targ_essent_len = bpf_core_essential_name_len(targ_name); |
|
if (targ_essent_len != cands->name_len) |
|
continue; |
|
|
|
/* most of the time there is only one candidate for a given kind+name pair */ |
|
new_cands = kmalloc(sizeof_cands(cands->cnt + 1), GFP_KERNEL); |
|
if (!new_cands) { |
|
bpf_free_cands(cands); |
|
return ERR_PTR(-ENOMEM); |
|
} |
|
|
|
memcpy(new_cands, cands, sizeof_cands(cands->cnt)); |
|
bpf_free_cands(cands); |
|
cands = new_cands; |
|
cands->cands[cands->cnt].btf = targ_btf; |
|
cands->cands[cands->cnt].id = i; |
|
cands->cnt++; |
|
} |
|
return cands; |
|
} |
|
|
|
static struct bpf_cand_cache * |
|
bpf_core_find_cands(struct bpf_core_ctx *ctx, u32 local_type_id) |
|
{ |
|
struct bpf_cand_cache *cands, *cc, local_cand = {}; |
|
const struct btf *local_btf = ctx->btf; |
|
const struct btf_type *local_type; |
|
const struct btf *main_btf; |
|
size_t local_essent_len; |
|
struct btf *mod_btf; |
|
const char *name; |
|
int id; |
|
|
|
main_btf = bpf_get_btf_vmlinux(); |
|
if (IS_ERR(main_btf)) |
|
return ERR_CAST(main_btf); |
|
if (!main_btf) |
|
return ERR_PTR(-EINVAL); |
|
|
|
local_type = btf_type_by_id(local_btf, local_type_id); |
|
if (!local_type) |
|
return ERR_PTR(-EINVAL); |
|
|
|
name = btf_name_by_offset(local_btf, local_type->name_off); |
|
if (str_is_empty(name)) |
|
return ERR_PTR(-EINVAL); |
|
local_essent_len = bpf_core_essential_name_len(name); |
|
|
|
cands = &local_cand; |
|
cands->name = name; |
|
cands->kind = btf_kind(local_type); |
|
cands->name_len = local_essent_len; |
|
|
|
cc = check_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); |
|
/* cands is a pointer to stack here */ |
|
if (cc) { |
|
if (cc->cnt) |
|
return cc; |
|
goto check_modules; |
|
} |
|
|
|
/* Attempt to find target candidates in vmlinux BTF first */ |
|
cands = bpf_core_add_cands(cands, main_btf, 1); |
|
if (IS_ERR(cands)) |
|
return ERR_CAST(cands); |
|
|
|
/* cands is a pointer to kmalloced memory here if cands->cnt > 0 */ |
|
|
|
/* populate cache even when cands->cnt == 0 */ |
|
cc = populate_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); |
|
if (IS_ERR(cc)) |
|
return ERR_CAST(cc); |
|
|
|
/* if vmlinux BTF has any candidate, don't go for module BTFs */ |
|
if (cc->cnt) |
|
return cc; |
|
|
|
check_modules: |
|
/* cands is a pointer to stack here and cands->cnt == 0 */ |
|
cc = check_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); |
|
if (cc) |
|
/* if cache has it return it even if cc->cnt == 0 */ |
|
return cc; |
|
|
|
/* If candidate is not found in vmlinux's BTF then search in module's BTFs */ |
|
spin_lock_bh(&btf_idr_lock); |
|
idr_for_each_entry(&btf_idr, mod_btf, id) { |
|
if (!btf_is_module(mod_btf)) |
|
continue; |
|
/* linear search could be slow hence unlock/lock |
|
* the IDR to avoiding holding it for too long |
|
*/ |
|
btf_get(mod_btf); |
|
spin_unlock_bh(&btf_idr_lock); |
|
cands = bpf_core_add_cands(cands, mod_btf, btf_nr_types(main_btf)); |
|
if (IS_ERR(cands)) { |
|
btf_put(mod_btf); |
|
return ERR_CAST(cands); |
|
} |
|
spin_lock_bh(&btf_idr_lock); |
|
btf_put(mod_btf); |
|
} |
|
spin_unlock_bh(&btf_idr_lock); |
|
/* cands is a pointer to kmalloced memory here if cands->cnt > 0 |
|
* or pointer to stack if cands->cnd == 0. |
|
* Copy it into the cache even when cands->cnt == 0 and |
|
* return the result. |
|
*/ |
|
return populate_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); |
|
} |
|
|
|
int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo, |
|
int relo_idx, void *insn) |
|
{ |
|
bool need_cands = relo->kind != BPF_CORE_TYPE_ID_LOCAL; |
|
struct bpf_core_cand_list cands = {}; |
|
struct bpf_core_relo_res targ_res; |
|
struct bpf_core_spec *specs; |
|
int err; |
|
|
|
/* ~4k of temp memory necessary to convert LLVM spec like "0:1:0:5" |
|
* into arrays of btf_ids of struct fields and array indices. |
|
*/ |
|
specs = kcalloc(3, sizeof(*specs), GFP_KERNEL); |
|
if (!specs) |
|
return -ENOMEM; |
|
|
|
if (need_cands) { |
|
struct bpf_cand_cache *cc; |
|
int i; |
|
|
|
mutex_lock(&cand_cache_mutex); |
|
cc = bpf_core_find_cands(ctx, relo->type_id); |
|
if (IS_ERR(cc)) { |
|
bpf_log(ctx->log, "target candidate search failed for %d\n", |
|
relo->type_id); |
|
err = PTR_ERR(cc); |
|
goto out; |
|
} |
|
if (cc->cnt) { |
|
cands.cands = kcalloc(cc->cnt, sizeof(*cands.cands), GFP_KERNEL); |
|
if (!cands.cands) { |
|
err = -ENOMEM; |
|
goto out; |
|
} |
|
} |
|
for (i = 0; i < cc->cnt; i++) { |
|
bpf_log(ctx->log, |
|
"CO-RE relocating %s %s: found target candidate [%d]\n", |
|
btf_kind_str[cc->kind], cc->name, cc->cands[i].id); |
|
cands.cands[i].btf = cc->cands[i].btf; |
|
cands.cands[i].id = cc->cands[i].id; |
|
} |
|
cands.len = cc->cnt; |
|
/* cand_cache_mutex needs to span the cache lookup and |
|
* copy of btf pointer into bpf_core_cand_list, |
|
* since module can be unloaded while bpf_core_calc_relo_insn |
|
* is working with module's btf. |
|
*/ |
|
} |
|
|
|
err = bpf_core_calc_relo_insn((void *)ctx->log, relo, relo_idx, ctx->btf, &cands, specs, |
|
&targ_res); |
|
if (err) |
|
goto out; |
|
|
|
err = bpf_core_patch_insn((void *)ctx->log, insn, relo->insn_off / 8, relo, relo_idx, |
|
&targ_res); |
|
|
|
out: |
|
kfree(specs); |
|
if (need_cands) { |
|
kfree(cands.cands); |
|
mutex_unlock(&cand_cache_mutex); |
|
if (ctx->log->level & BPF_LOG_LEVEL2) |
|
print_cand_cache(ctx->log); |
|
} |
|
return err; |
|
}
|
|
|