Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
efb1a57d | 2 | #include <linux/cache.h> |
0097875b | 3 | #include <linux/sched.h> |
0097875b EB |
4 | #include <linux/slab.h> |
5 | #include <linux/pid_namespace.h> | |
6 | #include "internal.h" | |
7 | ||
8 | /* | |
9 | * /proc/thread_self: | |
10 | */ | |
6b255391 | 11 | static const char *proc_thread_self_get_link(struct dentry *dentry, |
fceef393 AV |
12 | struct inode *inode, |
13 | struct delayed_call *done) | |
0097875b | 14 | { |
9d78edea | 15 | struct pid_namespace *ns = proc_pid_ns(inode->i_sb); |
0097875b EB |
16 | pid_t tgid = task_tgid_nr_ns(current, ns); |
17 | pid_t pid = task_pid_nr_ns(current, ns); | |
680baacb AV |
18 | char *name; |
19 | ||
20 | if (!pid) | |
21 | return ERR_PTR(-ENOENT); | |
e3912ac3 | 22 | name = kmalloc(10 + 6 + 10 + 1, dentry ? GFP_KERNEL : GFP_ATOMIC); |
1a384eaa AV |
23 | if (unlikely(!name)) |
24 | return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD); | |
e3912ac3 | 25 | sprintf(name, "%u/task/%u", tgid, pid); |
fceef393 AV |
26 | set_delayed_call(done, kfree_link, name); |
27 | return name; | |
0097875b EB |
28 | } |
29 | ||
30 | static const struct inode_operations proc_thread_self_inode_operations = { | |
6b255391 | 31 | .get_link = proc_thread_self_get_link, |
0097875b EB |
32 | }; |
33 | ||
efb1a57d | 34 | static unsigned thread_self_inum __ro_after_init; |
0097875b EB |
35 | |
36 | int proc_setup_thread_self(struct super_block *s) | |
37 | { | |
2b0143b5 | 38 | struct inode *root_inode = d_inode(s->s_root); |
fa10fed3 | 39 | struct proc_fs_info *fs_info = proc_sb_info(s); |
0097875b | 40 | struct dentry *thread_self; |
45f68ab5 | 41 | int ret = -ENOMEM; |
0097875b | 42 | |
5955102c | 43 | inode_lock(root_inode); |
0097875b EB |
44 | thread_self = d_alloc_name(s->s_root, "thread-self"); |
45 | if (thread_self) { | |
ef1548ad | 46 | struct inode *inode = new_inode(s); |
0097875b EB |
47 | if (inode) { |
48 | inode->i_ino = thread_self_inum; | |
200d9421 | 49 | simple_inode_init_ts(inode); |
0097875b EB |
50 | inode->i_mode = S_IFLNK | S_IRWXUGO; |
51 | inode->i_uid = GLOBAL_ROOT_UID; | |
52 | inode->i_gid = GLOBAL_ROOT_GID; | |
53 | inode->i_op = &proc_thread_self_inode_operations; | |
54 | d_add(thread_self, inode); | |
45f68ab5 | 55 | ret = 0; |
0097875b EB |
56 | } else { |
57 | dput(thread_self); | |
0097875b | 58 | } |
0097875b | 59 | } |
5955102c | 60 | inode_unlock(root_inode); |
45f68ab5 CX |
61 | |
62 | if (ret) | |
fa10fed3 | 63 | pr_err("proc_fill_super: can't allocate /proc/thread-self\n"); |
45f68ab5 | 64 | else |
fa10fed3 | 65 | fs_info->proc_thread_self = thread_self; |
45f68ab5 CX |
66 | |
67 | return ret; | |
0097875b EB |
68 | } |
69 | ||
70 | void __init proc_thread_self_init(void) | |
71 | { | |
72 | proc_alloc_inum(&thread_self_inum); | |
73 | } |