[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_follow_link(struct dentry *dentry, void **cookie)
{
	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 *name;

	if (!pid)
		return ERR_PTR(-ENOENT);
	name = kmalloc(PROC_NUMBUF + 6 + PROC_NUMBUF, GFP_KERNEL);
	if (!name)
		return ERR_PTR(-ENOMEM);
	sprintf(name, "%d/task/%d", tgid, pid);
	return *cookie = name;
}

static const struct inode_operations proc_thread_self_inode_operations = {
	.readlink	= proc_thread_self_readlink,
	.follow_link	= proc_thread_self_follow_link,
	.put_link	= kfree_put_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;

	mutex_lock(&root_inode->i_mutex);
	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);
	}
	mutex_unlock(&root_inode->i_mutex);
	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
6e77137b	22	static const char proc_thread_self_follow_link(struct dentry dentry, void **cookie)
0097875b EB	23	{
	24	struct pid_namespace *ns = dentry->d_sb->s_fs_info;
	25	pid_t tgid = task_tgid_nr_ns(current, ns);
	26	pid_t pid = task_pid_nr_ns(current, ns);
680baacb AV	27	char *name;
	28
	29	if (!pid)
	30	return ERR_PTR(-ENOENT);
	31	name = kmalloc(PROC_NUMBUF + 6 + PROC_NUMBUF, GFP_KERNEL);
	32	if (!name)
	33	return ERR_PTR(-ENOMEM);
	34	sprintf(name, "%d/task/%d", tgid, pid);
	35	return *cookie = name;
0097875b EB	36	}
	37
	38	static const struct inode_operations proc_thread_self_inode_operations = {
	39	.readlink = proc_thread_self_readlink,
	40	.follow_link = proc_thread_self_follow_link,
	41	.put_link = kfree_put_link,
	42	};
	43
	44	static unsigned thread_self_inum;
	45
	46	int proc_setup_thread_self(struct super_block *s)
	47	{
2b0143b5	48	struct inode *root_inode = d_inode(s->s_root);
0097875b EB	49	struct pid_namespace *ns = s->s_fs_info;
	50	struct dentry *thread_self;
	51
	52	mutex_lock(&root_inode->i_mutex);
	53	thread_self = d_alloc_name(s->s_root, "thread-self");
	54	if (thread_self) {
	55	struct inode *inode = new_inode_pseudo(s);
	56	if (inode) {
	57	inode->i_ino = thread_self_inum;
	58	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
	59	inode->i_mode = S_IFLNK \| S_IRWXUGO;
	60	inode->i_uid = GLOBAL_ROOT_UID;
	61	inode->i_gid = GLOBAL_ROOT_GID;
	62	inode->i_op = &proc_thread_self_inode_operations;
	63	d_add(thread_self, inode);
	64	} else {
	65	dput(thread_self);
	66	thread_self = ERR_PTR(-ENOMEM);
	67	}
	68	} else {
	69	thread_self = ERR_PTR(-ENOMEM);
	70	}
	71	mutex_unlock(&root_inode->i_mutex);
	72	if (IS_ERR(thread_self)) {
	73	pr_err("proc_fill_super: can't allocate /proc/thread_self\n");
	74	return PTR_ERR(thread_self);
	75	}
	76	ns->proc_thread_self = thread_self;
	77	return 0;
	78	}
	79
	80	void __init proc_thread_self_init(void)
	81	{
	82	proc_alloc_inum(&thread_self_inum);
	83	}