[linux-2.6-block.git] / fs / proc / thread_self.c

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/pid_namespace.h>
#include "internal.h"

/*
 * /proc/thread_self:
 */
static int proc_thread_self_readlink(struct dentry *dentry, char __user *buffer,
			      int buflen)
{
	struct pid_namespace *ns = dentry->d_sb->s_fs_info;
	pid_t tgid = task_tgid_nr_ns(current, ns);
	pid_t pid = task_pid_nr_ns(current, ns);
	char tmp[PROC_NUMBUF + 6 + PROC_NUMBUF];
	if (!pid)
		return -ENOENT;
	sprintf(tmp, "%d/task/%d", tgid, pid);
	return readlink_copy(buffer, buflen, tmp);
}

static const char *proc_thread_self_get_link(struct dentry *dentry,
					     struct inode *inode,
					     struct delayed_call *done)
{
	struct pid_namespace *ns = inode->i_sb->s_fs_info;
	pid_t tgid = task_tgid_nr_ns(current, ns);
	pid_t pid = task_pid_nr_ns(current, ns);
	char *name;

	if (!pid)
		return ERR_PTR(-ENOENT);
	name = kmalloc(PROC_NUMBUF + 6 + PROC_NUMBUF,
				dentry ? GFP_KERNEL : GFP_ATOMIC);
	if (unlikely(!name))
		return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD);
	sprintf(name, "%d/task/%d", tgid, pid);
	set_delayed_call(done, kfree_link, name);
	return name;
}

static const struct inode_operations proc_thread_self_inode_operations = {
	.readlink	= proc_thread_self_readlink,
	.get_link	= proc_thread_self_get_link,
};

static unsigned thread_self_inum;

int proc_setup_thread_self(struct super_block *s)
{
	struct inode *root_inode = d_inode(s->s_root);
	struct pid_namespace *ns = s->s_fs_info;
	struct dentry *thread_self;

	inode_lock(root_inode);
	thread_self = d_alloc_name(s->s_root, "thread-self");
	if (thread_self) {
		struct inode *inode = new_inode_pseudo(s);
		if (inode) {
			inode->i_ino = thread_self_inum;
			inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
			inode->i_mode = S_IFLNK | S_IRWXUGO;
			inode->i_uid = GLOBAL_ROOT_UID;
			inode->i_gid = GLOBAL_ROOT_GID;
			inode->i_op = &proc_thread_self_inode_operations;
			d_add(thread_self, inode);
		} else {
			dput(thread_self);
			thread_self = ERR_PTR(-ENOMEM);
		}
	} else {
		thread_self = ERR_PTR(-ENOMEM);
	}
	inode_unlock(root_inode);
	if (IS_ERR(thread_self)) {
		pr_err("proc_fill_super: can't allocate /proc/thread_self\n");
		return PTR_ERR(thread_self);
	}
	ns->proc_thread_self = thread_self;
	return 0;
}

void __init proc_thread_self_init(void)
{
	proc_alloc_inum(&thread_self_inum);
}
Commit	Line	Data
0097875b	1	#include <linux/sched.h>
0097875b EB	2	#include <linux/slab.h>
	3	#include <linux/pid_namespace.h>
	4	#include "internal.h"
	5
	6	/*
	7	* /proc/thread_self:
	8	*/
	9	static int proc_thread_self_readlink(struct dentry dentry, char __user buffer,
	10	int buflen)
	11	{
	12	struct pid_namespace *ns = dentry->d_sb->s_fs_info;
	13	pid_t tgid = task_tgid_nr_ns(current, ns);
	14	pid_t pid = task_pid_nr_ns(current, ns);
	15	char tmp[PROC_NUMBUF + 6 + PROC_NUMBUF];
	16	if (!pid)
	17	return -ENOENT;
	18	sprintf(tmp, "%d/task/%d", tgid, pid);
	19	return readlink_copy(buffer, buflen, tmp);
	20	}
	21
6b255391	22	static const char proc_thread_self_get_link(struct dentry dentry,
fceef393 AV	23	struct inode *inode,
fceef393 AV	24	struct delayed_call *done)
0097875b	25	{
6b255391	26	struct pid_namespace *ns = inode->i_sb->s_fs_info;
0097875b EB	27	pid_t tgid = task_tgid_nr_ns(current, ns);
0097875b EB	28	pid_t pid = task_pid_nr_ns(current, ns);
680baacb AV	29	char *name;
	30
	31	if (!pid)
	32	return ERR_PTR(-ENOENT);
1a384eaa AV	33	name = kmalloc(PROC_NUMBUF + 6 + PROC_NUMBUF,
	34	dentry ? GFP_KERNEL : GFP_ATOMIC);
	35	if (unlikely(!name))
	36	return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD);
680baacb	37	sprintf(name, "%d/task/%d", tgid, pid);
fceef393 AV	38	set_delayed_call(done, kfree_link, name);
fceef393 AV	39	return name;
0097875b EB	40	}
	41
	42	static const struct inode_operations proc_thread_self_inode_operations = {
	43	.readlink = proc_thread_self_readlink,
6b255391	44	.get_link = proc_thread_self_get_link,
0097875b EB	45	};
	46
	47	static unsigned thread_self_inum;
	48
	49	int proc_setup_thread_self(struct super_block *s)
	50	{
2b0143b5	51	struct inode *root_inode = d_inode(s->s_root);
0097875b EB	52	struct pid_namespace *ns = s->s_fs_info;
	53	struct dentry *thread_self;
	54
5955102c	55	inode_lock(root_inode);
0097875b EB	56	thread_self = d_alloc_name(s->s_root, "thread-self");
	57	if (thread_self) {
	58	struct inode *inode = new_inode_pseudo(s);
	59	if (inode) {
	60	inode->i_ino = thread_self_inum;
	61	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
	62	inode->i_mode = S_IFLNK \| S_IRWXUGO;
	63	inode->i_uid = GLOBAL_ROOT_UID;
	64	inode->i_gid = GLOBAL_ROOT_GID;
	65	inode->i_op = &proc_thread_self_inode_operations;
	66	d_add(thread_self, inode);
	67	} else {
	68	dput(thread_self);
	69	thread_self = ERR_PTR(-ENOMEM);
	70	}
	71	} else {
	72	thread_self = ERR_PTR(-ENOMEM);
	73	}
5955102c	74	inode_unlock(root_inode);
0097875b EB	75	if (IS_ERR(thread_self)) {
	76	pr_err("proc_fill_super: can't allocate /proc/thread_self\n");
	77	return PTR_ERR(thread_self);
	78	}
	79	ns->proc_thread_self = thread_self;
	80	return 0;
	81	}
	82
	83	void __init proc_thread_self_init(void)
	84	{
	85	proc_alloc_inum(&thread_self_inum);
	86	}