mirror of https://github.com/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.
1357 lines
31 KiB
1357 lines
31 KiB
/* |
|
* uprobes-based tracing events |
|
* |
|
* This program is free software; you can redistribute it and/or modify |
|
* it under the terms of the GNU General Public License version 2 as |
|
* published by the Free Software Foundation. |
|
* |
|
* This program is distributed in the hope that it will be useful, |
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
|
* GNU General Public License for more details. |
|
* |
|
* You should have received a copy of the GNU General Public License |
|
* along with this program; if not, write to the Free Software |
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
|
* |
|
* Copyright (C) IBM Corporation, 2010-2012 |
|
* Author: Srikar Dronamraju <[email protected]> |
|
*/ |
|
|
|
#include <linux/module.h> |
|
#include <linux/uaccess.h> |
|
#include <linux/uprobes.h> |
|
#include <linux/namei.h> |
|
#include <linux/string.h> |
|
|
|
#include "trace_probe.h" |
|
|
|
#define UPROBE_EVENT_SYSTEM "uprobes" |
|
|
|
struct uprobe_trace_entry_head { |
|
struct trace_entry ent; |
|
unsigned long vaddr[]; |
|
}; |
|
|
|
#define SIZEOF_TRACE_ENTRY(is_return) \ |
|
(sizeof(struct uprobe_trace_entry_head) + \ |
|
sizeof(unsigned long) * (is_return ? 2 : 1)) |
|
|
|
#define DATAOF_TRACE_ENTRY(entry, is_return) \ |
|
((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return)) |
|
|
|
struct trace_uprobe_filter { |
|
rwlock_t rwlock; |
|
int nr_systemwide; |
|
struct list_head perf_events; |
|
}; |
|
|
|
/* |
|
* uprobe event core functions |
|
*/ |
|
struct trace_uprobe { |
|
struct list_head list; |
|
struct trace_uprobe_filter filter; |
|
struct uprobe_consumer consumer; |
|
struct inode *inode; |
|
char *filename; |
|
unsigned long offset; |
|
unsigned long nhit; |
|
struct trace_probe tp; |
|
}; |
|
|
|
#define SIZEOF_TRACE_UPROBE(n) \ |
|
(offsetof(struct trace_uprobe, tp.args) + \ |
|
(sizeof(struct probe_arg) * (n))) |
|
|
|
static int register_uprobe_event(struct trace_uprobe *tu); |
|
static int unregister_uprobe_event(struct trace_uprobe *tu); |
|
|
|
static DEFINE_MUTEX(uprobe_lock); |
|
static LIST_HEAD(uprobe_list); |
|
|
|
struct uprobe_dispatch_data { |
|
struct trace_uprobe *tu; |
|
unsigned long bp_addr; |
|
}; |
|
|
|
static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); |
|
static int uretprobe_dispatcher(struct uprobe_consumer *con, |
|
unsigned long func, struct pt_regs *regs); |
|
|
|
#ifdef CONFIG_STACK_GROWSUP |
|
static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) |
|
{ |
|
return addr - (n * sizeof(long)); |
|
} |
|
#else |
|
static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) |
|
{ |
|
return addr + (n * sizeof(long)); |
|
} |
|
#endif |
|
|
|
static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n) |
|
{ |
|
unsigned long ret; |
|
unsigned long addr = user_stack_pointer(regs); |
|
|
|
addr = adjust_stack_addr(addr, n); |
|
|
|
if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret))) |
|
return 0; |
|
|
|
return ret; |
|
} |
|
|
|
/* |
|
* Uprobes-specific fetch functions |
|
*/ |
|
#define DEFINE_FETCH_stack(type) \ |
|
static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \ |
|
void *offset, void *dest) \ |
|
{ \ |
|
*(type *)dest = (type)get_user_stack_nth(regs, \ |
|
((unsigned long)offset)); \ |
|
} |
|
DEFINE_BASIC_FETCH_FUNCS(stack) |
|
/* No string on the stack entry */ |
|
#define fetch_stack_string NULL |
|
#define fetch_stack_string_size NULL |
|
|
|
#define DEFINE_FETCH_memory(type) \ |
|
static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \ |
|
void *addr, void *dest) \ |
|
{ \ |
|
type retval; \ |
|
void __user *vaddr = (void __force __user *) addr; \ |
|
\ |
|
if (copy_from_user(&retval, vaddr, sizeof(type))) \ |
|
*(type *)dest = 0; \ |
|
else \ |
|
*(type *) dest = retval; \ |
|
} |
|
DEFINE_BASIC_FETCH_FUNCS(memory) |
|
/* |
|
* Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max |
|
* length and relative data location. |
|
*/ |
|
static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, |
|
void *addr, void *dest) |
|
{ |
|
long ret; |
|
u32 rloc = *(u32 *)dest; |
|
int maxlen = get_rloc_len(rloc); |
|
u8 *dst = get_rloc_data(dest); |
|
void __user *src = (void __force __user *) addr; |
|
|
|
if (!maxlen) |
|
return; |
|
|
|
ret = strncpy_from_user(dst, src, maxlen); |
|
|
|
if (ret < 0) { /* Failed to fetch string */ |
|
((u8 *)get_rloc_data(dest))[0] = '\0'; |
|
*(u32 *)dest = make_data_rloc(0, get_rloc_offs(rloc)); |
|
} else { |
|
*(u32 *)dest = make_data_rloc(ret, get_rloc_offs(rloc)); |
|
} |
|
} |
|
|
|
static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, |
|
void *addr, void *dest) |
|
{ |
|
int len; |
|
void __user *vaddr = (void __force __user *) addr; |
|
|
|
len = strnlen_user(vaddr, MAX_STRING_SIZE); |
|
|
|
if (len == 0 || len > MAX_STRING_SIZE) /* Failed to check length */ |
|
*(u32 *)dest = 0; |
|
else |
|
*(u32 *)dest = len; |
|
} |
|
|
|
static unsigned long translate_user_vaddr(void *file_offset) |
|
{ |
|
unsigned long base_addr; |
|
struct uprobe_dispatch_data *udd; |
|
|
|
udd = (void *) current->utask->vaddr; |
|
|
|
base_addr = udd->bp_addr - udd->tu->offset; |
|
return base_addr + (unsigned long)file_offset; |
|
} |
|
|
|
#define DEFINE_FETCH_file_offset(type) \ |
|
static void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs, \ |
|
void *offset, void *dest)\ |
|
{ \ |
|
void *vaddr = (void *)translate_user_vaddr(offset); \ |
|
\ |
|
FETCH_FUNC_NAME(memory, type)(regs, vaddr, dest); \ |
|
} |
|
DEFINE_BASIC_FETCH_FUNCS(file_offset) |
|
DEFINE_FETCH_file_offset(string) |
|
DEFINE_FETCH_file_offset(string_size) |
|
|
|
/* Fetch type information table */ |
|
static const struct fetch_type uprobes_fetch_type_table[] = { |
|
/* Special types */ |
|
[FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, |
|
sizeof(u32), 1, "__data_loc char[]"), |
|
[FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, |
|
string_size, sizeof(u32), 0, "u32"), |
|
/* Basic types */ |
|
ASSIGN_FETCH_TYPE(u8, u8, 0), |
|
ASSIGN_FETCH_TYPE(u16, u16, 0), |
|
ASSIGN_FETCH_TYPE(u32, u32, 0), |
|
ASSIGN_FETCH_TYPE(u64, u64, 0), |
|
ASSIGN_FETCH_TYPE(s8, u8, 1), |
|
ASSIGN_FETCH_TYPE(s16, u16, 1), |
|
ASSIGN_FETCH_TYPE(s32, u32, 1), |
|
ASSIGN_FETCH_TYPE(s64, u64, 1), |
|
ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), |
|
ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), |
|
ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), |
|
ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), |
|
|
|
ASSIGN_FETCH_TYPE_END |
|
}; |
|
|
|
static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter) |
|
{ |
|
rwlock_init(&filter->rwlock); |
|
filter->nr_systemwide = 0; |
|
INIT_LIST_HEAD(&filter->perf_events); |
|
} |
|
|
|
static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter) |
|
{ |
|
return !filter->nr_systemwide && list_empty(&filter->perf_events); |
|
} |
|
|
|
static inline bool is_ret_probe(struct trace_uprobe *tu) |
|
{ |
|
return tu->consumer.ret_handler != NULL; |
|
} |
|
|
|
/* |
|
* Allocate new trace_uprobe and initialize it (including uprobes). |
|
*/ |
|
static struct trace_uprobe * |
|
alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret) |
|
{ |
|
struct trace_uprobe *tu; |
|
|
|
if (!event || !is_good_name(event)) |
|
return ERR_PTR(-EINVAL); |
|
|
|
if (!group || !is_good_name(group)) |
|
return ERR_PTR(-EINVAL); |
|
|
|
tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL); |
|
if (!tu) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
tu->tp.call.class = &tu->tp.class; |
|
tu->tp.call.name = kstrdup(event, GFP_KERNEL); |
|
if (!tu->tp.call.name) |
|
goto error; |
|
|
|
tu->tp.class.system = kstrdup(group, GFP_KERNEL); |
|
if (!tu->tp.class.system) |
|
goto error; |
|
|
|
INIT_LIST_HEAD(&tu->list); |
|
INIT_LIST_HEAD(&tu->tp.files); |
|
tu->consumer.handler = uprobe_dispatcher; |
|
if (is_ret) |
|
tu->consumer.ret_handler = uretprobe_dispatcher; |
|
init_trace_uprobe_filter(&tu->filter); |
|
return tu; |
|
|
|
error: |
|
kfree(tu->tp.call.name); |
|
kfree(tu); |
|
|
|
return ERR_PTR(-ENOMEM); |
|
} |
|
|
|
static void free_trace_uprobe(struct trace_uprobe *tu) |
|
{ |
|
int i; |
|
|
|
for (i = 0; i < tu->tp.nr_args; i++) |
|
traceprobe_free_probe_arg(&tu->tp.args[i]); |
|
|
|
iput(tu->inode); |
|
kfree(tu->tp.call.class->system); |
|
kfree(tu->tp.call.name); |
|
kfree(tu->filename); |
|
kfree(tu); |
|
} |
|
|
|
static struct trace_uprobe *find_probe_event(const char *event, const char *group) |
|
{ |
|
struct trace_uprobe *tu; |
|
|
|
list_for_each_entry(tu, &uprobe_list, list) |
|
if (strcmp(trace_event_name(&tu->tp.call), event) == 0 && |
|
strcmp(tu->tp.call.class->system, group) == 0) |
|
return tu; |
|
|
|
return NULL; |
|
} |
|
|
|
/* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */ |
|
static int unregister_trace_uprobe(struct trace_uprobe *tu) |
|
{ |
|
int ret; |
|
|
|
ret = unregister_uprobe_event(tu); |
|
if (ret) |
|
return ret; |
|
|
|
list_del(&tu->list); |
|
free_trace_uprobe(tu); |
|
return 0; |
|
} |
|
|
|
/* Register a trace_uprobe and probe_event */ |
|
static int register_trace_uprobe(struct trace_uprobe *tu) |
|
{ |
|
struct trace_uprobe *old_tu; |
|
int ret; |
|
|
|
mutex_lock(&uprobe_lock); |
|
|
|
/* register as an event */ |
|
old_tu = find_probe_event(trace_event_name(&tu->tp.call), |
|
tu->tp.call.class->system); |
|
if (old_tu) { |
|
/* delete old event */ |
|
ret = unregister_trace_uprobe(old_tu); |
|
if (ret) |
|
goto end; |
|
} |
|
|
|
ret = register_uprobe_event(tu); |
|
if (ret) { |
|
pr_warn("Failed to register probe event(%d)\n", ret); |
|
goto end; |
|
} |
|
|
|
list_add_tail(&tu->list, &uprobe_list); |
|
|
|
end: |
|
mutex_unlock(&uprobe_lock); |
|
|
|
return ret; |
|
} |
|
|
|
/* |
|
* Argument syntax: |
|
* - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] |
|
* |
|
* - Remove uprobe: -:[GRP/]EVENT |
|
*/ |
|
static int create_trace_uprobe(int argc, char **argv) |
|
{ |
|
struct trace_uprobe *tu; |
|
struct inode *inode; |
|
char *arg, *event, *group, *filename; |
|
char buf[MAX_EVENT_NAME_LEN]; |
|
struct path path; |
|
unsigned long offset; |
|
bool is_delete, is_return; |
|
int i, ret; |
|
|
|
inode = NULL; |
|
ret = 0; |
|
is_delete = false; |
|
is_return = false; |
|
event = NULL; |
|
group = NULL; |
|
|
|
/* argc must be >= 1 */ |
|
if (argv[0][0] == '-') |
|
is_delete = true; |
|
else if (argv[0][0] == 'r') |
|
is_return = true; |
|
else if (argv[0][0] != 'p') { |
|
pr_info("Probe definition must be started with 'p', 'r' or '-'.\n"); |
|
return -EINVAL; |
|
} |
|
|
|
if (argv[0][1] == ':') { |
|
event = &argv[0][2]; |
|
arg = strchr(event, '/'); |
|
|
|
if (arg) { |
|
group = event; |
|
event = arg + 1; |
|
event[-1] = '\0'; |
|
|
|
if (strlen(group) == 0) { |
|
pr_info("Group name is not specified\n"); |
|
return -EINVAL; |
|
} |
|
} |
|
if (strlen(event) == 0) { |
|
pr_info("Event name is not specified\n"); |
|
return -EINVAL; |
|
} |
|
} |
|
if (!group) |
|
group = UPROBE_EVENT_SYSTEM; |
|
|
|
if (is_delete) { |
|
int ret; |
|
|
|
if (!event) { |
|
pr_info("Delete command needs an event name.\n"); |
|
return -EINVAL; |
|
} |
|
mutex_lock(&uprobe_lock); |
|
tu = find_probe_event(event, group); |
|
|
|
if (!tu) { |
|
mutex_unlock(&uprobe_lock); |
|
pr_info("Event %s/%s doesn't exist.\n", group, event); |
|
return -ENOENT; |
|
} |
|
/* delete an event */ |
|
ret = unregister_trace_uprobe(tu); |
|
mutex_unlock(&uprobe_lock); |
|
return ret; |
|
} |
|
|
|
if (argc < 2) { |
|
pr_info("Probe point is not specified.\n"); |
|
return -EINVAL; |
|
} |
|
arg = strchr(argv[1], ':'); |
|
if (!arg) { |
|
ret = -EINVAL; |
|
goto fail_address_parse; |
|
} |
|
|
|
*arg++ = '\0'; |
|
filename = argv[1]; |
|
ret = kern_path(filename, LOOKUP_FOLLOW, &path); |
|
if (ret) |
|
goto fail_address_parse; |
|
|
|
inode = igrab(d_inode(path.dentry)); |
|
path_put(&path); |
|
|
|
if (!inode || !S_ISREG(inode->i_mode)) { |
|
ret = -EINVAL; |
|
goto fail_address_parse; |
|
} |
|
|
|
ret = kstrtoul(arg, 0, &offset); |
|
if (ret) |
|
goto fail_address_parse; |
|
|
|
argc -= 2; |
|
argv += 2; |
|
|
|
/* setup a probe */ |
|
if (!event) { |
|
char *tail; |
|
char *ptr; |
|
|
|
tail = kstrdup(kbasename(filename), GFP_KERNEL); |
|
if (!tail) { |
|
ret = -ENOMEM; |
|
goto fail_address_parse; |
|
} |
|
|
|
ptr = strpbrk(tail, ".-_"); |
|
if (ptr) |
|
*ptr = '\0'; |
|
|
|
snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); |
|
event = buf; |
|
kfree(tail); |
|
} |
|
|
|
tu = alloc_trace_uprobe(group, event, argc, is_return); |
|
if (IS_ERR(tu)) { |
|
pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu)); |
|
ret = PTR_ERR(tu); |
|
goto fail_address_parse; |
|
} |
|
tu->offset = offset; |
|
tu->inode = inode; |
|
tu->filename = kstrdup(filename, GFP_KERNEL); |
|
|
|
if (!tu->filename) { |
|
pr_info("Failed to allocate filename.\n"); |
|
ret = -ENOMEM; |
|
goto error; |
|
} |
|
|
|
/* parse arguments */ |
|
ret = 0; |
|
for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { |
|
struct probe_arg *parg = &tu->tp.args[i]; |
|
|
|
/* Increment count for freeing args in error case */ |
|
tu->tp.nr_args++; |
|
|
|
/* Parse argument name */ |
|
arg = strchr(argv[i], '='); |
|
if (arg) { |
|
*arg++ = '\0'; |
|
parg->name = kstrdup(argv[i], GFP_KERNEL); |
|
} else { |
|
arg = argv[i]; |
|
/* If argument name is omitted, set "argN" */ |
|
snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); |
|
parg->name = kstrdup(buf, GFP_KERNEL); |
|
} |
|
|
|
if (!parg->name) { |
|
pr_info("Failed to allocate argument[%d] name.\n", i); |
|
ret = -ENOMEM; |
|
goto error; |
|
} |
|
|
|
if (!is_good_name(parg->name)) { |
|
pr_info("Invalid argument[%d] name: %s\n", i, parg->name); |
|
ret = -EINVAL; |
|
goto error; |
|
} |
|
|
|
if (traceprobe_conflict_field_name(parg->name, tu->tp.args, i)) { |
|
pr_info("Argument[%d] name '%s' conflicts with " |
|
"another field.\n", i, argv[i]); |
|
ret = -EINVAL; |
|
goto error; |
|
} |
|
|
|
/* Parse fetch argument */ |
|
ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg, |
|
is_return, false, |
|
uprobes_fetch_type_table); |
|
if (ret) { |
|
pr_info("Parse error at argument[%d]. (%d)\n", i, ret); |
|
goto error; |
|
} |
|
} |
|
|
|
ret = register_trace_uprobe(tu); |
|
if (ret) |
|
goto error; |
|
return 0; |
|
|
|
error: |
|
free_trace_uprobe(tu); |
|
return ret; |
|
|
|
fail_address_parse: |
|
iput(inode); |
|
|
|
pr_info("Failed to parse address or file.\n"); |
|
|
|
return ret; |
|
} |
|
|
|
static int cleanup_all_probes(void) |
|
{ |
|
struct trace_uprobe *tu; |
|
int ret = 0; |
|
|
|
mutex_lock(&uprobe_lock); |
|
while (!list_empty(&uprobe_list)) { |
|
tu = list_entry(uprobe_list.next, struct trace_uprobe, list); |
|
ret = unregister_trace_uprobe(tu); |
|
if (ret) |
|
break; |
|
} |
|
mutex_unlock(&uprobe_lock); |
|
return ret; |
|
} |
|
|
|
/* Probes listing interfaces */ |
|
static void *probes_seq_start(struct seq_file *m, loff_t *pos) |
|
{ |
|
mutex_lock(&uprobe_lock); |
|
return seq_list_start(&uprobe_list, *pos); |
|
} |
|
|
|
static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) |
|
{ |
|
return seq_list_next(v, &uprobe_list, pos); |
|
} |
|
|
|
static void probes_seq_stop(struct seq_file *m, void *v) |
|
{ |
|
mutex_unlock(&uprobe_lock); |
|
} |
|
|
|
static int probes_seq_show(struct seq_file *m, void *v) |
|
{ |
|
struct trace_uprobe *tu = v; |
|
char c = is_ret_probe(tu) ? 'r' : 'p'; |
|
int i; |
|
|
|
seq_printf(m, "%c:%s/%s", c, tu->tp.call.class->system, |
|
trace_event_name(&tu->tp.call)); |
|
seq_printf(m, " %s:", tu->filename); |
|
|
|
/* Don't print "0x (null)" when offset is 0 */ |
|
if (tu->offset) { |
|
seq_printf(m, "0x%p", (void *)tu->offset); |
|
} else { |
|
switch (sizeof(void *)) { |
|
case 4: |
|
seq_printf(m, "0x00000000"); |
|
break; |
|
case 8: |
|
default: |
|
seq_printf(m, "0x0000000000000000"); |
|
break; |
|
} |
|
} |
|
|
|
for (i = 0; i < tu->tp.nr_args; i++) |
|
seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm); |
|
|
|
seq_putc(m, '\n'); |
|
return 0; |
|
} |
|
|
|
static const struct seq_operations probes_seq_op = { |
|
.start = probes_seq_start, |
|
.next = probes_seq_next, |
|
.stop = probes_seq_stop, |
|
.show = probes_seq_show |
|
}; |
|
|
|
static int probes_open(struct inode *inode, struct file *file) |
|
{ |
|
int ret; |
|
|
|
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { |
|
ret = cleanup_all_probes(); |
|
if (ret) |
|
return ret; |
|
} |
|
|
|
return seq_open(file, &probes_seq_op); |
|
} |
|
|
|
static ssize_t probes_write(struct file *file, const char __user *buffer, |
|
size_t count, loff_t *ppos) |
|
{ |
|
return traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe); |
|
} |
|
|
|
static const struct file_operations uprobe_events_ops = { |
|
.owner = THIS_MODULE, |
|
.open = probes_open, |
|
.read = seq_read, |
|
.llseek = seq_lseek, |
|
.release = seq_release, |
|
.write = probes_write, |
|
}; |
|
|
|
/* Probes profiling interfaces */ |
|
static int probes_profile_seq_show(struct seq_file *m, void *v) |
|
{ |
|
struct trace_uprobe *tu = v; |
|
|
|
seq_printf(m, " %s %-44s %15lu\n", tu->filename, |
|
trace_event_name(&tu->tp.call), tu->nhit); |
|
return 0; |
|
} |
|
|
|
static const struct seq_operations profile_seq_op = { |
|
.start = probes_seq_start, |
|
.next = probes_seq_next, |
|
.stop = probes_seq_stop, |
|
.show = probes_profile_seq_show |
|
}; |
|
|
|
static int profile_open(struct inode *inode, struct file *file) |
|
{ |
|
return seq_open(file, &profile_seq_op); |
|
} |
|
|
|
static const struct file_operations uprobe_profile_ops = { |
|
.owner = THIS_MODULE, |
|
.open = profile_open, |
|
.read = seq_read, |
|
.llseek = seq_lseek, |
|
.release = seq_release, |
|
}; |
|
|
|
struct uprobe_cpu_buffer { |
|
struct mutex mutex; |
|
void *buf; |
|
}; |
|
static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer; |
|
static int uprobe_buffer_refcnt; |
|
|
|
static int uprobe_buffer_init(void) |
|
{ |
|
int cpu, err_cpu; |
|
|
|
uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer); |
|
if (uprobe_cpu_buffer == NULL) |
|
return -ENOMEM; |
|
|
|
for_each_possible_cpu(cpu) { |
|
struct page *p = alloc_pages_node(cpu_to_node(cpu), |
|
GFP_KERNEL, 0); |
|
if (p == NULL) { |
|
err_cpu = cpu; |
|
goto err; |
|
} |
|
per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p); |
|
mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex); |
|
} |
|
|
|
return 0; |
|
|
|
err: |
|
for_each_possible_cpu(cpu) { |
|
if (cpu == err_cpu) |
|
break; |
|
free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf); |
|
} |
|
|
|
free_percpu(uprobe_cpu_buffer); |
|
return -ENOMEM; |
|
} |
|
|
|
static int uprobe_buffer_enable(void) |
|
{ |
|
int ret = 0; |
|
|
|
BUG_ON(!mutex_is_locked(&event_mutex)); |
|
|
|
if (uprobe_buffer_refcnt++ == 0) { |
|
ret = uprobe_buffer_init(); |
|
if (ret < 0) |
|
uprobe_buffer_refcnt--; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static void uprobe_buffer_disable(void) |
|
{ |
|
int cpu; |
|
|
|
BUG_ON(!mutex_is_locked(&event_mutex)); |
|
|
|
if (--uprobe_buffer_refcnt == 0) { |
|
for_each_possible_cpu(cpu) |
|
free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, |
|
cpu)->buf); |
|
|
|
free_percpu(uprobe_cpu_buffer); |
|
uprobe_cpu_buffer = NULL; |
|
} |
|
} |
|
|
|
static struct uprobe_cpu_buffer *uprobe_buffer_get(void) |
|
{ |
|
struct uprobe_cpu_buffer *ucb; |
|
int cpu; |
|
|
|
cpu = raw_smp_processor_id(); |
|
ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu); |
|
|
|
/* |
|
* Use per-cpu buffers for fastest access, but we might migrate |
|
* so the mutex makes sure we have sole access to it. |
|
*/ |
|
mutex_lock(&ucb->mutex); |
|
|
|
return ucb; |
|
} |
|
|
|
static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb) |
|
{ |
|
mutex_unlock(&ucb->mutex); |
|
} |
|
|
|
static void __uprobe_trace_func(struct trace_uprobe *tu, |
|
unsigned long func, struct pt_regs *regs, |
|
struct uprobe_cpu_buffer *ucb, int dsize, |
|
struct trace_event_file *trace_file) |
|
{ |
|
struct uprobe_trace_entry_head *entry; |
|
struct ring_buffer_event *event; |
|
struct ring_buffer *buffer; |
|
void *data; |
|
int size, esize; |
|
struct trace_event_call *call = &tu->tp.call; |
|
|
|
WARN_ON(call != trace_file->event_call); |
|
|
|
if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE)) |
|
return; |
|
|
|
if (trace_trigger_soft_disabled(trace_file)) |
|
return; |
|
|
|
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); |
|
size = esize + tu->tp.size + dsize; |
|
event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
|
call->event.type, size, 0, 0); |
|
if (!event) |
|
return; |
|
|
|
entry = ring_buffer_event_data(event); |
|
if (is_ret_probe(tu)) { |
|
entry->vaddr[0] = func; |
|
entry->vaddr[1] = instruction_pointer(regs); |
|
data = DATAOF_TRACE_ENTRY(entry, true); |
|
} else { |
|
entry->vaddr[0] = instruction_pointer(regs); |
|
data = DATAOF_TRACE_ENTRY(entry, false); |
|
} |
|
|
|
memcpy(data, ucb->buf, tu->tp.size + dsize); |
|
|
|
event_trigger_unlock_commit(trace_file, buffer, event, entry, 0, 0); |
|
} |
|
|
|
/* uprobe handler */ |
|
static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs, |
|
struct uprobe_cpu_buffer *ucb, int dsize) |
|
{ |
|
struct event_file_link *link; |
|
|
|
if (is_ret_probe(tu)) |
|
return 0; |
|
|
|
rcu_read_lock(); |
|
list_for_each_entry_rcu(link, &tu->tp.files, list) |
|
__uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file); |
|
rcu_read_unlock(); |
|
|
|
return 0; |
|
} |
|
|
|
static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func, |
|
struct pt_regs *regs, |
|
struct uprobe_cpu_buffer *ucb, int dsize) |
|
{ |
|
struct event_file_link *link; |
|
|
|
rcu_read_lock(); |
|
list_for_each_entry_rcu(link, &tu->tp.files, list) |
|
__uprobe_trace_func(tu, func, regs, ucb, dsize, link->file); |
|
rcu_read_unlock(); |
|
} |
|
|
|
/* Event entry printers */ |
|
static enum print_line_t |
|
print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) |
|
{ |
|
struct uprobe_trace_entry_head *entry; |
|
struct trace_seq *s = &iter->seq; |
|
struct trace_uprobe *tu; |
|
u8 *data; |
|
int i; |
|
|
|
entry = (struct uprobe_trace_entry_head *)iter->ent; |
|
tu = container_of(event, struct trace_uprobe, tp.call.event); |
|
|
|
if (is_ret_probe(tu)) { |
|
trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", |
|
trace_event_name(&tu->tp.call), |
|
entry->vaddr[1], entry->vaddr[0]); |
|
data = DATAOF_TRACE_ENTRY(entry, true); |
|
} else { |
|
trace_seq_printf(s, "%s: (0x%lx)", |
|
trace_event_name(&tu->tp.call), |
|
entry->vaddr[0]); |
|
data = DATAOF_TRACE_ENTRY(entry, false); |
|
} |
|
|
|
for (i = 0; i < tu->tp.nr_args; i++) { |
|
struct probe_arg *parg = &tu->tp.args[i]; |
|
|
|
if (!parg->type->print(s, parg->name, data + parg->offset, entry)) |
|
goto out; |
|
} |
|
|
|
trace_seq_putc(s, '\n'); |
|
|
|
out: |
|
return trace_handle_return(s); |
|
} |
|
|
|
typedef bool (*filter_func_t)(struct uprobe_consumer *self, |
|
enum uprobe_filter_ctx ctx, |
|
struct mm_struct *mm); |
|
|
|
static int |
|
probe_event_enable(struct trace_uprobe *tu, struct trace_event_file *file, |
|
filter_func_t filter) |
|
{ |
|
bool enabled = trace_probe_is_enabled(&tu->tp); |
|
struct event_file_link *link = NULL; |
|
int ret; |
|
|
|
if (file) { |
|
if (tu->tp.flags & TP_FLAG_PROFILE) |
|
return -EINTR; |
|
|
|
link = kmalloc(sizeof(*link), GFP_KERNEL); |
|
if (!link) |
|
return -ENOMEM; |
|
|
|
link->file = file; |
|
list_add_tail_rcu(&link->list, &tu->tp.files); |
|
|
|
tu->tp.flags |= TP_FLAG_TRACE; |
|
} else { |
|
if (tu->tp.flags & TP_FLAG_TRACE) |
|
return -EINTR; |
|
|
|
tu->tp.flags |= TP_FLAG_PROFILE; |
|
} |
|
|
|
WARN_ON(!uprobe_filter_is_empty(&tu->filter)); |
|
|
|
if (enabled) |
|
return 0; |
|
|
|
ret = uprobe_buffer_enable(); |
|
if (ret) |
|
goto err_flags; |
|
|
|
tu->consumer.filter = filter; |
|
ret = uprobe_register(tu->inode, tu->offset, &tu->consumer); |
|
if (ret) |
|
goto err_buffer; |
|
|
|
return 0; |
|
|
|
err_buffer: |
|
uprobe_buffer_disable(); |
|
|
|
err_flags: |
|
if (file) { |
|
list_del(&link->list); |
|
kfree(link); |
|
tu->tp.flags &= ~TP_FLAG_TRACE; |
|
} else { |
|
tu->tp.flags &= ~TP_FLAG_PROFILE; |
|
} |
|
return ret; |
|
} |
|
|
|
static void |
|
probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file) |
|
{ |
|
if (!trace_probe_is_enabled(&tu->tp)) |
|
return; |
|
|
|
if (file) { |
|
struct event_file_link *link; |
|
|
|
link = find_event_file_link(&tu->tp, file); |
|
if (!link) |
|
return; |
|
|
|
list_del_rcu(&link->list); |
|
/* synchronize with u{,ret}probe_trace_func */ |
|
synchronize_sched(); |
|
kfree(link); |
|
|
|
if (!list_empty(&tu->tp.files)) |
|
return; |
|
} |
|
|
|
WARN_ON(!uprobe_filter_is_empty(&tu->filter)); |
|
|
|
uprobe_unregister(tu->inode, tu->offset, &tu->consumer); |
|
tu->tp.flags &= file ? ~TP_FLAG_TRACE : ~TP_FLAG_PROFILE; |
|
|
|
uprobe_buffer_disable(); |
|
} |
|
|
|
static int uprobe_event_define_fields(struct trace_event_call *event_call) |
|
{ |
|
int ret, i, size; |
|
struct uprobe_trace_entry_head field; |
|
struct trace_uprobe *tu = event_call->data; |
|
|
|
if (is_ret_probe(tu)) { |
|
DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0); |
|
DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0); |
|
size = SIZEOF_TRACE_ENTRY(true); |
|
} else { |
|
DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0); |
|
size = SIZEOF_TRACE_ENTRY(false); |
|
} |
|
/* Set argument names as fields */ |
|
for (i = 0; i < tu->tp.nr_args; i++) { |
|
struct probe_arg *parg = &tu->tp.args[i]; |
|
|
|
ret = trace_define_field(event_call, parg->type->fmttype, |
|
parg->name, size + parg->offset, |
|
parg->type->size, parg->type->is_signed, |
|
FILTER_OTHER); |
|
|
|
if (ret) |
|
return ret; |
|
} |
|
return 0; |
|
} |
|
|
|
#ifdef CONFIG_PERF_EVENTS |
|
static bool |
|
__uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm) |
|
{ |
|
struct perf_event *event; |
|
|
|
if (filter->nr_systemwide) |
|
return true; |
|
|
|
list_for_each_entry(event, &filter->perf_events, hw.tp_list) { |
|
if (event->hw.target->mm == mm) |
|
return true; |
|
} |
|
|
|
return false; |
|
} |
|
|
|
static inline bool |
|
uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event) |
|
{ |
|
return __uprobe_perf_filter(&tu->filter, event->hw.target->mm); |
|
} |
|
|
|
static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event) |
|
{ |
|
bool done; |
|
|
|
write_lock(&tu->filter.rwlock); |
|
if (event->hw.target) { |
|
list_del(&event->hw.tp_list); |
|
done = tu->filter.nr_systemwide || |
|
(event->hw.target->flags & PF_EXITING) || |
|
uprobe_filter_event(tu, event); |
|
} else { |
|
tu->filter.nr_systemwide--; |
|
done = tu->filter.nr_systemwide; |
|
} |
|
write_unlock(&tu->filter.rwlock); |
|
|
|
if (!done) |
|
return uprobe_apply(tu->inode, tu->offset, &tu->consumer, false); |
|
|
|
return 0; |
|
} |
|
|
|
static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event) |
|
{ |
|
bool done; |
|
int err; |
|
|
|
write_lock(&tu->filter.rwlock); |
|
if (event->hw.target) { |
|
/* |
|
* event->parent != NULL means copy_process(), we can avoid |
|
* uprobe_apply(). current->mm must be probed and we can rely |
|
* on dup_mmap() which preserves the already installed bp's. |
|
* |
|
* attr.enable_on_exec means that exec/mmap will install the |
|
* breakpoints we need. |
|
*/ |
|
done = tu->filter.nr_systemwide || |
|
event->parent || event->attr.enable_on_exec || |
|
uprobe_filter_event(tu, event); |
|
list_add(&event->hw.tp_list, &tu->filter.perf_events); |
|
} else { |
|
done = tu->filter.nr_systemwide; |
|
tu->filter.nr_systemwide++; |
|
} |
|
write_unlock(&tu->filter.rwlock); |
|
|
|
err = 0; |
|
if (!done) { |
|
err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true); |
|
if (err) |
|
uprobe_perf_close(tu, event); |
|
} |
|
return err; |
|
} |
|
|
|
static bool uprobe_perf_filter(struct uprobe_consumer *uc, |
|
enum uprobe_filter_ctx ctx, struct mm_struct *mm) |
|
{ |
|
struct trace_uprobe *tu; |
|
int ret; |
|
|
|
tu = container_of(uc, struct trace_uprobe, consumer); |
|
read_lock(&tu->filter.rwlock); |
|
ret = __uprobe_perf_filter(&tu->filter, mm); |
|
read_unlock(&tu->filter.rwlock); |
|
|
|
return ret; |
|
} |
|
|
|
static void __uprobe_perf_func(struct trace_uprobe *tu, |
|
unsigned long func, struct pt_regs *regs, |
|
struct uprobe_cpu_buffer *ucb, int dsize) |
|
{ |
|
struct trace_event_call *call = &tu->tp.call; |
|
struct uprobe_trace_entry_head *entry; |
|
struct bpf_prog *prog = call->prog; |
|
struct hlist_head *head; |
|
void *data; |
|
int size, esize; |
|
int rctx; |
|
|
|
if (prog && !trace_call_bpf(prog, regs)) |
|
return; |
|
|
|
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); |
|
|
|
size = esize + tu->tp.size + dsize; |
|
size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32); |
|
if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) |
|
return; |
|
|
|
preempt_disable(); |
|
head = this_cpu_ptr(call->perf_events); |
|
if (hlist_empty(head)) |
|
goto out; |
|
|
|
entry = perf_trace_buf_alloc(size, NULL, &rctx); |
|
if (!entry) |
|
goto out; |
|
|
|
if (is_ret_probe(tu)) { |
|
entry->vaddr[0] = func; |
|
entry->vaddr[1] = instruction_pointer(regs); |
|
data = DATAOF_TRACE_ENTRY(entry, true); |
|
} else { |
|
entry->vaddr[0] = instruction_pointer(regs); |
|
data = DATAOF_TRACE_ENTRY(entry, false); |
|
} |
|
|
|
memcpy(data, ucb->buf, tu->tp.size + dsize); |
|
|
|
if (size - esize > tu->tp.size + dsize) { |
|
int len = tu->tp.size + dsize; |
|
|
|
memset(data + len, 0, size - esize - len); |
|
} |
|
|
|
perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
|
head, NULL); |
|
out: |
|
preempt_enable(); |
|
} |
|
|
|
/* uprobe profile handler */ |
|
static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs, |
|
struct uprobe_cpu_buffer *ucb, int dsize) |
|
{ |
|
if (!uprobe_perf_filter(&tu->consumer, 0, current->mm)) |
|
return UPROBE_HANDLER_REMOVE; |
|
|
|
if (!is_ret_probe(tu)) |
|
__uprobe_perf_func(tu, 0, regs, ucb, dsize); |
|
return 0; |
|
} |
|
|
|
static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func, |
|
struct pt_regs *regs, |
|
struct uprobe_cpu_buffer *ucb, int dsize) |
|
{ |
|
__uprobe_perf_func(tu, func, regs, ucb, dsize); |
|
} |
|
#endif /* CONFIG_PERF_EVENTS */ |
|
|
|
static int |
|
trace_uprobe_register(struct trace_event_call *event, enum trace_reg type, |
|
void *data) |
|
{ |
|
struct trace_uprobe *tu = event->data; |
|
struct trace_event_file *file = data; |
|
|
|
switch (type) { |
|
case TRACE_REG_REGISTER: |
|
return probe_event_enable(tu, file, NULL); |
|
|
|
case TRACE_REG_UNREGISTER: |
|
probe_event_disable(tu, file); |
|
return 0; |
|
|
|
#ifdef CONFIG_PERF_EVENTS |
|
case TRACE_REG_PERF_REGISTER: |
|
return probe_event_enable(tu, NULL, uprobe_perf_filter); |
|
|
|
case TRACE_REG_PERF_UNREGISTER: |
|
probe_event_disable(tu, NULL); |
|
return 0; |
|
|
|
case TRACE_REG_PERF_OPEN: |
|
return uprobe_perf_open(tu, data); |
|
|
|
case TRACE_REG_PERF_CLOSE: |
|
return uprobe_perf_close(tu, data); |
|
|
|
#endif |
|
default: |
|
return 0; |
|
} |
|
return 0; |
|
} |
|
|
|
static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) |
|
{ |
|
struct trace_uprobe *tu; |
|
struct uprobe_dispatch_data udd; |
|
struct uprobe_cpu_buffer *ucb; |
|
int dsize, esize; |
|
int ret = 0; |
|
|
|
|
|
tu = container_of(con, struct trace_uprobe, consumer); |
|
tu->nhit++; |
|
|
|
udd.tu = tu; |
|
udd.bp_addr = instruction_pointer(regs); |
|
|
|
current->utask->vaddr = (unsigned long) &udd; |
|
|
|
if (WARN_ON_ONCE(!uprobe_cpu_buffer)) |
|
return 0; |
|
|
|
dsize = __get_data_size(&tu->tp, regs); |
|
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); |
|
|
|
ucb = uprobe_buffer_get(); |
|
store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize); |
|
|
|
if (tu->tp.flags & TP_FLAG_TRACE) |
|
ret |= uprobe_trace_func(tu, regs, ucb, dsize); |
|
|
|
#ifdef CONFIG_PERF_EVENTS |
|
if (tu->tp.flags & TP_FLAG_PROFILE) |
|
ret |= uprobe_perf_func(tu, regs, ucb, dsize); |
|
#endif |
|
uprobe_buffer_put(ucb); |
|
return ret; |
|
} |
|
|
|
static int uretprobe_dispatcher(struct uprobe_consumer *con, |
|
unsigned long func, struct pt_regs *regs) |
|
{ |
|
struct trace_uprobe *tu; |
|
struct uprobe_dispatch_data udd; |
|
struct uprobe_cpu_buffer *ucb; |
|
int dsize, esize; |
|
|
|
tu = container_of(con, struct trace_uprobe, consumer); |
|
|
|
udd.tu = tu; |
|
udd.bp_addr = func; |
|
|
|
current->utask->vaddr = (unsigned long) &udd; |
|
|
|
if (WARN_ON_ONCE(!uprobe_cpu_buffer)) |
|
return 0; |
|
|
|
dsize = __get_data_size(&tu->tp, regs); |
|
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); |
|
|
|
ucb = uprobe_buffer_get(); |
|
store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize); |
|
|
|
if (tu->tp.flags & TP_FLAG_TRACE) |
|
uretprobe_trace_func(tu, func, regs, ucb, dsize); |
|
|
|
#ifdef CONFIG_PERF_EVENTS |
|
if (tu->tp.flags & TP_FLAG_PROFILE) |
|
uretprobe_perf_func(tu, func, regs, ucb, dsize); |
|
#endif |
|
uprobe_buffer_put(ucb); |
|
return 0; |
|
} |
|
|
|
static struct trace_event_functions uprobe_funcs = { |
|
.trace = print_uprobe_event |
|
}; |
|
|
|
static int register_uprobe_event(struct trace_uprobe *tu) |
|
{ |
|
struct trace_event_call *call = &tu->tp.call; |
|
int ret; |
|
|
|
/* Initialize trace_event_call */ |
|
INIT_LIST_HEAD(&call->class->fields); |
|
call->event.funcs = &uprobe_funcs; |
|
call->class->define_fields = uprobe_event_define_fields; |
|
|
|
if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) |
|
return -ENOMEM; |
|
|
|
ret = register_trace_event(&call->event); |
|
if (!ret) { |
|
kfree(call->print_fmt); |
|
return -ENODEV; |
|
} |
|
|
|
call->flags = TRACE_EVENT_FL_UPROBE; |
|
call->class->reg = trace_uprobe_register; |
|
call->data = tu; |
|
ret = trace_add_event_call(call); |
|
|
|
if (ret) { |
|
pr_info("Failed to register uprobe event: %s\n", |
|
trace_event_name(call)); |
|
kfree(call->print_fmt); |
|
unregister_trace_event(&call->event); |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static int unregister_uprobe_event(struct trace_uprobe *tu) |
|
{ |
|
int ret; |
|
|
|
/* tu->event is unregistered in trace_remove_event_call() */ |
|
ret = trace_remove_event_call(&tu->tp.call); |
|
if (ret) |
|
return ret; |
|
kfree(tu->tp.call.print_fmt); |
|
tu->tp.call.print_fmt = NULL; |
|
return 0; |
|
} |
|
|
|
/* Make a trace interface for controling probe points */ |
|
static __init int init_uprobe_trace(void) |
|
{ |
|
struct dentry *d_tracer; |
|
|
|
d_tracer = tracing_init_dentry(); |
|
if (IS_ERR(d_tracer)) |
|
return 0; |
|
|
|
trace_create_file("uprobe_events", 0644, d_tracer, |
|
NULL, &uprobe_events_ops); |
|
/* Profile interface */ |
|
trace_create_file("uprobe_profile", 0444, d_tracer, |
|
NULL, &uprobe_profile_ops); |
|
return 0; |
|
} |
|
|
|
fs_initcall(init_uprobe_trace);
|
|
|