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.
373 lines
8.7 KiB
373 lines
8.7 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* |
|
* linux/fs/proc/root.c |
|
* |
|
* Copyright (C) 1991, 1992 Linus Torvalds |
|
* |
|
* proc root directory handling functions |
|
*/ |
|
|
|
#include <linux/uaccess.h> |
|
|
|
#include <linux/errno.h> |
|
#include <linux/time.h> |
|
#include <linux/proc_fs.h> |
|
#include <linux/stat.h> |
|
#include <linux/init.h> |
|
#include <linux/sched.h> |
|
#include <linux/sched/stat.h> |
|
#include <linux/module.h> |
|
#include <linux/bitops.h> |
|
#include <linux/user_namespace.h> |
|
#include <linux/fs_context.h> |
|
#include <linux/mount.h> |
|
#include <linux/pid_namespace.h> |
|
#include <linux/fs_parser.h> |
|
#include <linux/cred.h> |
|
#include <linux/magic.h> |
|
#include <linux/slab.h> |
|
|
|
#include "internal.h" |
|
|
|
struct proc_fs_context { |
|
struct pid_namespace *pid_ns; |
|
unsigned int mask; |
|
enum proc_hidepid hidepid; |
|
int gid; |
|
enum proc_pidonly pidonly; |
|
}; |
|
|
|
enum proc_param { |
|
Opt_gid, |
|
Opt_hidepid, |
|
Opt_subset, |
|
}; |
|
|
|
static const struct fs_parameter_spec proc_fs_parameters[] = { |
|
fsparam_u32("gid", Opt_gid), |
|
fsparam_string("hidepid", Opt_hidepid), |
|
fsparam_string("subset", Opt_subset), |
|
{} |
|
}; |
|
|
|
static inline int valid_hidepid(unsigned int value) |
|
{ |
|
return (value == HIDEPID_OFF || |
|
value == HIDEPID_NO_ACCESS || |
|
value == HIDEPID_INVISIBLE || |
|
value == HIDEPID_NOT_PTRACEABLE); |
|
} |
|
|
|
static int proc_parse_hidepid_param(struct fs_context *fc, struct fs_parameter *param) |
|
{ |
|
struct proc_fs_context *ctx = fc->fs_private; |
|
struct fs_parameter_spec hidepid_u32_spec = fsparam_u32("hidepid", Opt_hidepid); |
|
struct fs_parse_result result; |
|
int base = (unsigned long)hidepid_u32_spec.data; |
|
|
|
if (param->type != fs_value_is_string) |
|
return invalf(fc, "proc: unexpected type of hidepid value\n"); |
|
|
|
if (!kstrtouint(param->string, base, &result.uint_32)) { |
|
if (!valid_hidepid(result.uint_32)) |
|
return invalf(fc, "proc: unknown value of hidepid - %s\n", param->string); |
|
ctx->hidepid = result.uint_32; |
|
return 0; |
|
} |
|
|
|
if (!strcmp(param->string, "off")) |
|
ctx->hidepid = HIDEPID_OFF; |
|
else if (!strcmp(param->string, "noaccess")) |
|
ctx->hidepid = HIDEPID_NO_ACCESS; |
|
else if (!strcmp(param->string, "invisible")) |
|
ctx->hidepid = HIDEPID_INVISIBLE; |
|
else if (!strcmp(param->string, "ptraceable")) |
|
ctx->hidepid = HIDEPID_NOT_PTRACEABLE; |
|
else |
|
return invalf(fc, "proc: unknown value of hidepid - %s\n", param->string); |
|
|
|
return 0; |
|
} |
|
|
|
static int proc_parse_subset_param(struct fs_context *fc, char *value) |
|
{ |
|
struct proc_fs_context *ctx = fc->fs_private; |
|
|
|
while (value) { |
|
char *ptr = strchr(value, ','); |
|
|
|
if (ptr != NULL) |
|
*ptr++ = '\0'; |
|
|
|
if (*value != '\0') { |
|
if (!strcmp(value, "pid")) { |
|
ctx->pidonly = PROC_PIDONLY_ON; |
|
} else { |
|
return invalf(fc, "proc: unsupported subset option - %s\n", value); |
|
} |
|
} |
|
value = ptr; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int proc_parse_param(struct fs_context *fc, struct fs_parameter *param) |
|
{ |
|
struct proc_fs_context *ctx = fc->fs_private; |
|
struct fs_parse_result result; |
|
int opt; |
|
|
|
opt = fs_parse(fc, proc_fs_parameters, param, &result); |
|
if (opt < 0) |
|
return opt; |
|
|
|
switch (opt) { |
|
case Opt_gid: |
|
ctx->gid = result.uint_32; |
|
break; |
|
|
|
case Opt_hidepid: |
|
if (proc_parse_hidepid_param(fc, param)) |
|
return -EINVAL; |
|
break; |
|
|
|
case Opt_subset: |
|
if (proc_parse_subset_param(fc, param->string) < 0) |
|
return -EINVAL; |
|
break; |
|
|
|
default: |
|
return -EINVAL; |
|
} |
|
|
|
ctx->mask |= 1 << opt; |
|
return 0; |
|
} |
|
|
|
static void proc_apply_options(struct proc_fs_info *fs_info, |
|
struct fs_context *fc, |
|
struct user_namespace *user_ns) |
|
{ |
|
struct proc_fs_context *ctx = fc->fs_private; |
|
|
|
if (ctx->mask & (1 << Opt_gid)) |
|
fs_info->pid_gid = make_kgid(user_ns, ctx->gid); |
|
if (ctx->mask & (1 << Opt_hidepid)) |
|
fs_info->hide_pid = ctx->hidepid; |
|
if (ctx->mask & (1 << Opt_subset)) |
|
fs_info->pidonly = ctx->pidonly; |
|
} |
|
|
|
static int proc_fill_super(struct super_block *s, struct fs_context *fc) |
|
{ |
|
struct proc_fs_context *ctx = fc->fs_private; |
|
struct inode *root_inode; |
|
struct proc_fs_info *fs_info; |
|
int ret; |
|
|
|
fs_info = kzalloc(sizeof(*fs_info), GFP_KERNEL); |
|
if (!fs_info) |
|
return -ENOMEM; |
|
|
|
fs_info->pid_ns = get_pid_ns(ctx->pid_ns); |
|
proc_apply_options(fs_info, fc, current_user_ns()); |
|
|
|
/* User space would break if executables or devices appear on proc */ |
|
s->s_iflags |= SB_I_USERNS_VISIBLE | SB_I_NOEXEC | SB_I_NODEV; |
|
s->s_flags |= SB_NODIRATIME | SB_NOSUID | SB_NOEXEC; |
|
s->s_blocksize = 1024; |
|
s->s_blocksize_bits = 10; |
|
s->s_magic = PROC_SUPER_MAGIC; |
|
s->s_op = &proc_sops; |
|
s->s_time_gran = 1; |
|
s->s_fs_info = fs_info; |
|
|
|
/* |
|
* procfs isn't actually a stacking filesystem; however, there is |
|
* too much magic going on inside it to permit stacking things on |
|
* top of it |
|
*/ |
|
s->s_stack_depth = FILESYSTEM_MAX_STACK_DEPTH; |
|
|
|
/* procfs dentries and inodes don't require IO to create */ |
|
s->s_shrink.seeks = 0; |
|
|
|
pde_get(&proc_root); |
|
root_inode = proc_get_inode(s, &proc_root); |
|
if (!root_inode) { |
|
pr_err("proc_fill_super: get root inode failed\n"); |
|
return -ENOMEM; |
|
} |
|
|
|
s->s_root = d_make_root(root_inode); |
|
if (!s->s_root) { |
|
pr_err("proc_fill_super: allocate dentry failed\n"); |
|
return -ENOMEM; |
|
} |
|
|
|
ret = proc_setup_self(s); |
|
if (ret) { |
|
return ret; |
|
} |
|
return proc_setup_thread_self(s); |
|
} |
|
|
|
static int proc_reconfigure(struct fs_context *fc) |
|
{ |
|
struct super_block *sb = fc->root->d_sb; |
|
struct proc_fs_info *fs_info = proc_sb_info(sb); |
|
|
|
sync_filesystem(sb); |
|
|
|
proc_apply_options(fs_info, fc, current_user_ns()); |
|
return 0; |
|
} |
|
|
|
static int proc_get_tree(struct fs_context *fc) |
|
{ |
|
return get_tree_nodev(fc, proc_fill_super); |
|
} |
|
|
|
static void proc_fs_context_free(struct fs_context *fc) |
|
{ |
|
struct proc_fs_context *ctx = fc->fs_private; |
|
|
|
put_pid_ns(ctx->pid_ns); |
|
kfree(ctx); |
|
} |
|
|
|
static const struct fs_context_operations proc_fs_context_ops = { |
|
.free = proc_fs_context_free, |
|
.parse_param = proc_parse_param, |
|
.get_tree = proc_get_tree, |
|
.reconfigure = proc_reconfigure, |
|
}; |
|
|
|
static int proc_init_fs_context(struct fs_context *fc) |
|
{ |
|
struct proc_fs_context *ctx; |
|
|
|
ctx = kzalloc(sizeof(struct proc_fs_context), GFP_KERNEL); |
|
if (!ctx) |
|
return -ENOMEM; |
|
|
|
ctx->pid_ns = get_pid_ns(task_active_pid_ns(current)); |
|
put_user_ns(fc->user_ns); |
|
fc->user_ns = get_user_ns(ctx->pid_ns->user_ns); |
|
fc->fs_private = ctx; |
|
fc->ops = &proc_fs_context_ops; |
|
return 0; |
|
} |
|
|
|
static void proc_kill_sb(struct super_block *sb) |
|
{ |
|
struct proc_fs_info *fs_info = proc_sb_info(sb); |
|
|
|
if (!fs_info) { |
|
kill_anon_super(sb); |
|
return; |
|
} |
|
|
|
dput(fs_info->proc_self); |
|
dput(fs_info->proc_thread_self); |
|
|
|
kill_anon_super(sb); |
|
put_pid_ns(fs_info->pid_ns); |
|
kfree(fs_info); |
|
} |
|
|
|
static struct file_system_type proc_fs_type = { |
|
.name = "proc", |
|
.init_fs_context = proc_init_fs_context, |
|
.parameters = proc_fs_parameters, |
|
.kill_sb = proc_kill_sb, |
|
.fs_flags = FS_USERNS_MOUNT | FS_DISALLOW_NOTIFY_PERM, |
|
}; |
|
|
|
void __init proc_root_init(void) |
|
{ |
|
proc_init_kmemcache(); |
|
set_proc_pid_nlink(); |
|
proc_self_init(); |
|
proc_thread_self_init(); |
|
proc_symlink("mounts", NULL, "self/mounts"); |
|
|
|
proc_net_init(); |
|
proc_mkdir("fs", NULL); |
|
proc_mkdir("driver", NULL); |
|
proc_create_mount_point("fs/nfsd"); /* somewhere for the nfsd filesystem to be mounted */ |
|
#if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE) |
|
/* just give it a mountpoint */ |
|
proc_create_mount_point("openprom"); |
|
#endif |
|
proc_tty_init(); |
|
proc_mkdir("bus", NULL); |
|
proc_sys_init(); |
|
|
|
register_filesystem(&proc_fs_type); |
|
} |
|
|
|
static int proc_root_getattr(struct user_namespace *mnt_userns, |
|
const struct path *path, struct kstat *stat, |
|
u32 request_mask, unsigned int query_flags) |
|
{ |
|
generic_fillattr(&init_user_ns, d_inode(path->dentry), stat); |
|
stat->nlink = proc_root.nlink + nr_processes(); |
|
return 0; |
|
} |
|
|
|
static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags) |
|
{ |
|
if (!proc_pid_lookup(dentry, flags)) |
|
return NULL; |
|
|
|
return proc_lookup(dir, dentry, flags); |
|
} |
|
|
|
static int proc_root_readdir(struct file *file, struct dir_context *ctx) |
|
{ |
|
if (ctx->pos < FIRST_PROCESS_ENTRY) { |
|
int error = proc_readdir(file, ctx); |
|
if (unlikely(error <= 0)) |
|
return error; |
|
ctx->pos = FIRST_PROCESS_ENTRY; |
|
} |
|
|
|
return proc_pid_readdir(file, ctx); |
|
} |
|
|
|
/* |
|
* The root /proc directory is special, as it has the |
|
* <pid> directories. Thus we don't use the generic |
|
* directory handling functions for that.. |
|
*/ |
|
static const struct file_operations proc_root_operations = { |
|
.read = generic_read_dir, |
|
.iterate_shared = proc_root_readdir, |
|
.llseek = generic_file_llseek, |
|
}; |
|
|
|
/* |
|
* proc root can do almost nothing.. |
|
*/ |
|
static const struct inode_operations proc_root_inode_operations = { |
|
.lookup = proc_root_lookup, |
|
.getattr = proc_root_getattr, |
|
}; |
|
|
|
/* |
|
* This is the root "inode" in the /proc tree.. |
|
*/ |
|
struct proc_dir_entry proc_root = { |
|
.low_ino = PROC_ROOT_INO, |
|
.namelen = 5, |
|
.mode = S_IFDIR | S_IRUGO | S_IXUGO, |
|
.nlink = 2, |
|
.refcnt = REFCOUNT_INIT(1), |
|
.proc_iops = &proc_root_inode_operations, |
|
.proc_dir_ops = &proc_root_operations, |
|
.parent = &proc_root, |
|
.subdir = RB_ROOT, |
|
.name = "/proc", |
|
};
|
|
|