base.c 85.5 KB
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// SPDX-License-Identifier: GPL-2.0
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/*
 *  linux/fs/proc/base.c
 *
 *  Copyright (C) 1991, 1992 Linus Torvalds
 *
 *  proc base directory handling functions
 *
 *  1999, Al Viro. Rewritten. Now it covers the whole per-process part.
 *  Instead of using magical inumbers to determine the kind of object
 *  we allocate and fill in-core inodes upon lookup. They don't even
 *  go into icache. We cache the reference to task_struct upon lookup too.
 *  Eventually it should become a filesystem in its own. We don't use the
 *  rest of procfs anymore.
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 *
 *
 *  Changelog:
 *  17-Jan-2005
 *  Allan Bezerra
 *  Bruna Moreira <bruna.moreira@indt.org.br>
 *  Edjard Mota <edjard.mota@indt.org.br>
 *  Ilias Biris <ilias.biris@indt.org.br>
 *  Mauricio Lin <mauricio.lin@indt.org.br>
 *
 *  Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
 *
 *  A new process specific entry (smaps) included in /proc. It shows the
 *  size of rss for each memory area. The maps entry lacks information
 *  about physical memory size (rss) for each mapped file, i.e.,
 *  rss information for executables and library files.
 *  This additional information is useful for any tools that need to know
 *  about physical memory consumption for a process specific library.
 *
 *  Changelog:
 *  21-Feb-2005
 *  Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
 *  Pud inclusion in the page table walking.
 *
 *  ChangeLog:
 *  10-Mar-2005
 *  10LE Instituto Nokia de Tecnologia - INdT:
 *  A better way to walks through the page table as suggested by Hugh Dickins.
 *
 *  Simo Piiroinen <simo.piiroinen@nokia.com>:
 *  Smaps information related to shared, private, clean and dirty pages.
 *
 *  Paul Mundt <paul.mundt@nokia.com>:
 *  Overall revision about smaps.
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 */

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#include <linux/uaccess.h>
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#include <linux/errno.h>
#include <linux/time.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
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#include <linux/task_io_accounting_ops.h>
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#include <linux/init.h>
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#include <linux/capability.h>
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#include <linux/file.h>
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#include <linux/fdtable.h>
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#include <linux/string.h>
#include <linux/seq_file.h>
#include <linux/namei.h>
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#include <linux/mnt_namespace.h>
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#include <linux/mm.h>
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#include <linux/swap.h>
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#include <linux/rcupdate.h>
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#include <linux/kallsyms.h>
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#include <linux/stacktrace.h>
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#include <linux/resource.h>
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#include <linux/module.h>
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#include <linux/mount.h>
#include <linux/security.h>
#include <linux/ptrace.h>
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#include <linux/tracehook.h>
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#include <linux/printk.h>
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#include <linux/cache.h>
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#include <linux/cgroup.h>
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#include <linux/cpuset.h>
#include <linux/audit.h>
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#include <linux/poll.h>
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#include <linux/nsproxy.h>
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#include <linux/oom.h>
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#include <linux/elf.h>
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#include <linux/pid_namespace.h>
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#include <linux/user_namespace.h>
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#include <linux/fs_struct.h>
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#include <linux/slab.h>
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#include <linux/sched/autogroup.h>
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#include <linux/sched/mm.h>
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#include <linux/sched/coredump.h>
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#include <linux/sched/debug.h>
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#include <linux/sched/stat.h>
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#include <linux/flex_array.h>
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#include <linux/posix-timers.h>
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#include <trace/events/oom.h>
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#include "internal.h"
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#include "fd.h"
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#include "../../lib/kstrtox.h"

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/* NOTE:
 *	Implementing inode permission operations in /proc is almost
 *	certainly an error.  Permission checks need to happen during
 *	each system call not at open time.  The reason is that most of
 *	what we wish to check for permissions in /proc varies at runtime.
 *
 *	The classic example of a problem is opening file descriptors
 *	in /proc for a task before it execs a suid executable.
 */

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static u8 nlink_tid __ro_after_init;
static u8 nlink_tgid __ro_after_init;
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struct pid_entry {
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	const char *name;
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	unsigned int len;
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	umode_t mode;
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	const struct inode_operations *iop;
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	const struct file_operations *fop;
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	union proc_op op;
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};

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#define NOD(NAME, MODE, IOP, FOP, OP) {			\
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	.name = (NAME),					\
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	.len  = sizeof(NAME) - 1,			\
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	.mode = MODE,					\
	.iop  = IOP,					\
	.fop  = FOP,					\
	.op   = OP,					\
}

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#define DIR(NAME, MODE, iops, fops)	\
	NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
#define LNK(NAME, get_link)					\
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	NOD(NAME, (S_IFLNK|S_IRWXUGO),				\
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		&proc_pid_link_inode_operations, NULL,		\
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		{ .proc_get_link = get_link } )
#define REG(NAME, MODE, fops)				\
	NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
#define ONE(NAME, MODE, show)				\
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	NOD(NAME, (S_IFREG|(MODE)), 			\
		NULL, &proc_single_file_operations,	\
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		{ .proc_show = show } )
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/*
 * Count the number of hardlinks for the pid_entry table, excluding the .
 * and .. links.
 */
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static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
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	unsigned int n)
{
	unsigned int i;
	unsigned int count;

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	count = 2;
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	for (i = 0; i < n; ++i) {
		if (S_ISDIR(entries[i].mode))
			++count;
	}

	return count;
}

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static int get_task_root(struct task_struct *task, struct path *root)
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{
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	int result = -ENOENT;

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	task_lock(task);
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	if (task->fs) {
		get_fs_root(task->fs, root);
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		result = 0;
	}
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	task_unlock(task);
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	return result;
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}

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static int proc_cwd_link(struct dentry *dentry, struct path *path)
180
{
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	struct task_struct *task = get_proc_task(d_inode(dentry));
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	int result = -ENOENT;
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	if (task) {
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		task_lock(task);
		if (task->fs) {
			get_fs_pwd(task->fs, path);
			result = 0;
		}
		task_unlock(task);
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		put_task_struct(task);
	}
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	return result;
}

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static int proc_root_link(struct dentry *dentry, struct path *path)
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{
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	struct task_struct *task = get_proc_task(d_inode(dentry));
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	int result = -ENOENT;
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	if (task) {
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		result = get_task_root(task, path);
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		put_task_struct(task);
	}
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	return result;
}

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static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
				     size_t _count, loff_t *pos)
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{
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	struct task_struct *tsk;
	struct mm_struct *mm;
	char *page;
	unsigned long count = _count;
	unsigned long arg_start, arg_end, env_start, env_end;
	unsigned long len1, len2, len;
	unsigned long p;
	char c;
	ssize_t rv;

	BUG_ON(*pos < 0);

	tsk = get_proc_task(file_inode(file));
	if (!tsk)
		return -ESRCH;
	mm = get_task_mm(tsk);
	put_task_struct(tsk);
	if (!mm)
		return 0;
	/* Check if process spawned far enough to have cmdline. */
	if (!mm->env_end) {
		rv = 0;
		goto out_mmput;
	}

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	page = (char *)__get_free_page(GFP_KERNEL);
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	if (!page) {
		rv = -ENOMEM;
		goto out_mmput;
	}

	down_read(&mm->mmap_sem);
	arg_start = mm->arg_start;
	arg_end = mm->arg_end;
	env_start = mm->env_start;
	env_end = mm->env_end;
	up_read(&mm->mmap_sem);

	BUG_ON(arg_start > arg_end);
	BUG_ON(env_start > env_end);

	len1 = arg_end - arg_start;
	len2 = env_end - env_start;

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	/* Empty ARGV. */
	if (len1 == 0) {
		rv = 0;
		goto out_free_page;
	}
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	/*
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	 * Inherently racy -- command line shares address space
	 * with code and data.
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	 */
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	rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0);
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	if (rv <= 0)
		goto out_free_page;

	rv = 0;

	if (c == '\0') {
		/* Command line (set of strings) occupies whole ARGV. */
		if (len1 <= *pos)
			goto out_free_page;

		p = arg_start + *pos;
		len = len1 - *pos;
		while (count > 0 && len > 0) {
			unsigned int _count;
			int nr_read;

			_count = min3(count, len, PAGE_SIZE);
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			nr_read = access_remote_vm(mm, p, page, _count, 0);
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			if (nr_read < 0)
				rv = nr_read;
			if (nr_read <= 0)
				goto out_free_page;

			if (copy_to_user(buf, page, nr_read)) {
				rv = -EFAULT;
				goto out_free_page;
			}

			p	+= nr_read;
			len	-= nr_read;
			buf	+= nr_read;
			count	-= nr_read;
			rv	+= nr_read;
		}
	} else {
		/*
		 * Command line (1 string) occupies ARGV and
		 * extends into ENVP.
		 */
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		struct {
			unsigned long p;
			unsigned long len;
		} cmdline[2] = {
			{ .p = arg_start, .len = len1 },
			{ .p = env_start, .len = len2 },
		};
		loff_t pos1 = *pos;
		unsigned int i;

		i = 0;
		while (i < 2 && pos1 >= cmdline[i].len) {
			pos1 -= cmdline[i].len;
			i++;
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		}
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		while (i < 2) {
			p = cmdline[i].p + pos1;
			len = cmdline[i].len - pos1;
			while (count > 0 && len > 0) {
				unsigned int _count, l;
				int nr_read;
				bool final;

				_count = min3(count, len, PAGE_SIZE);
				nr_read = access_remote_vm(mm, p, page, _count, 0);
				if (nr_read < 0)
					rv = nr_read;
				if (nr_read <= 0)
					goto out_free_page;

				/*
				 * Command line can be shorter than whole ARGV
				 * even if last "marker" byte says it is not.
				 */
				final = false;
				l = strnlen(page, nr_read);
				if (l < nr_read) {
					nr_read = l;
					final = true;
				}

				if (copy_to_user(buf, page, nr_read)) {
					rv = -EFAULT;
					goto out_free_page;
				}

				p	+= nr_read;
				len	-= nr_read;
				buf	+= nr_read;
				count	-= nr_read;
				rv	+= nr_read;

				if (final)
					goto out_free_page;
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			}

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			/* Only first chunk can be read partially. */
			pos1 = 0;
			i++;
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		}
	}

out_free_page:
	free_page((unsigned long)page);
out_mmput:
	mmput(mm);
	if (rv > 0)
		*pos += rv;
	return rv;
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}

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static const struct file_operations proc_pid_cmdline_ops = {
	.read	= proc_pid_cmdline_read,
	.llseek	= generic_file_llseek,
};

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#ifdef CONFIG_KALLSYMS
/*
 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
 * Returns the resolved symbol.  If that fails, simply return the address.
 */
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static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
			  struct pid *pid, struct task_struct *task)
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{
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	unsigned long wchan;
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	char symname[KSYM_NAME_LEN];
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	wchan = get_wchan(task);

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	if (wchan && ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)
			&& !lookup_symbol_name(wchan, symname))
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		seq_printf(m, "%s", symname);
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	else
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		seq_putc(m, '0');
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	return 0;
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}
#endif /* CONFIG_KALLSYMS */

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static int lock_trace(struct task_struct *task)
{
	int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
	if (err)
		return err;
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	if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
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		mutex_unlock(&task->signal->cred_guard_mutex);
		return -EPERM;
	}
	return 0;
}

static void unlock_trace(struct task_struct *task)
{
	mutex_unlock(&task->signal->cred_guard_mutex);
}

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#ifdef CONFIG_STACKTRACE

#define MAX_STACK_TRACE_DEPTH	64

static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
			  struct pid *pid, struct task_struct *task)
{
	struct stack_trace trace;
	unsigned long *entries;
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	int err;
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	int i;

	entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
	if (!entries)
		return -ENOMEM;

	trace.nr_entries	= 0;
	trace.max_entries	= MAX_STACK_TRACE_DEPTH;
	trace.entries		= entries;
	trace.skip		= 0;

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	err = lock_trace(task);
	if (!err) {
		save_stack_trace_tsk(task, &trace);

		for (i = 0; i < trace.nr_entries; i++) {
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			seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
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		}
		unlock_trace(task);
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	}
	kfree(entries);

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	return err;
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}
#endif

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#ifdef CONFIG_SCHED_INFO
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/*
 * Provides /proc/PID/schedstat
 */
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static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
			      struct pid *pid, struct task_struct *task)
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{
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	if (unlikely(!sched_info_on()))
		seq_printf(m, "0 0 0\n");
	else
		seq_printf(m, "%llu %llu %lu\n",
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		   (unsigned long long)task->se.sum_exec_runtime,
		   (unsigned long long)task->sched_info.run_delay,
		   task->sched_info.pcount);

	return 0;
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}
#endif

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#ifdef CONFIG_LATENCYTOP
static int lstats_show_proc(struct seq_file *m, void *v)
{
	int i;
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	struct inode *inode = m->private;
	struct task_struct *task = get_proc_task(inode);
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	if (!task)
		return -ESRCH;
	seq_puts(m, "Latency Top version : v0.1\n");
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	for (i = 0; i < 32; i++) {
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		struct latency_record *lr = &task->latency_record[i];
		if (lr->backtrace[0]) {
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			int q;
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			seq_printf(m, "%i %li %li",
				   lr->count, lr->time, lr->max);
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			for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
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				unsigned long bt = lr->backtrace[q];
				if (!bt)
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					break;
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				if (bt == ULONG_MAX)
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					break;
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				seq_printf(m, " %ps", (void *)bt);
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			}
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			seq_putc(m, '\n');
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		}

	}
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	put_task_struct(task);
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	return 0;
}

static int lstats_open(struct inode *inode, struct file *file)
{
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	return single_open(file, lstats_show_proc, inode);
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}

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static ssize_t lstats_write(struct file *file, const char __user *buf,
			    size_t count, loff_t *offs)
{
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	struct task_struct *task = get_proc_task(file_inode(file));
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	if (!task)
		return -ESRCH;
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	clear_all_latency_tracing(task);
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	put_task_struct(task);
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	return count;
}

static const struct file_operations proc_lstats_operations = {
	.open		= lstats_open,
	.read		= seq_read,
	.write		= lstats_write,
	.llseek		= seq_lseek,
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	.release	= single_release,
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};

#endif

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static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
			  struct pid *pid, struct task_struct *task)
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{
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	unsigned long totalpages = totalram_pages + total_swap_pages;
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	unsigned long points = 0;
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	points = oom_badness(task, NULL, NULL, totalpages) *
					1000 / totalpages;
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	seq_printf(m, "%lu\n", points);

	return 0;
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}

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struct limit_names {
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	const char *name;
	const char *unit;
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};

static const struct limit_names lnames[RLIM_NLIMITS] = {
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	[RLIMIT_CPU] = {"Max cpu time", "seconds"},
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	[RLIMIT_FSIZE] = {"Max file size", "bytes"},
	[RLIMIT_DATA] = {"Max data size", "bytes"},
	[RLIMIT_STACK] = {"Max stack size", "bytes"},
	[RLIMIT_CORE] = {"Max core file size", "bytes"},
	[RLIMIT_RSS] = {"Max resident set", "bytes"},
	[RLIMIT_NPROC] = {"Max processes", "processes"},
	[RLIMIT_NOFILE] = {"Max open files", "files"},
	[RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
	[RLIMIT_AS] = {"Max address space", "bytes"},
	[RLIMIT_LOCKS] = {"Max file locks", "locks"},
	[RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
	[RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
	[RLIMIT_NICE] = {"Max nice priority", NULL},
	[RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
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	[RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
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};

/* Display limits for a process */
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static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
			   struct pid *pid, struct task_struct *task)
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{
	unsigned int i;
	unsigned long flags;

	struct rlimit rlim[RLIM_NLIMITS];

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	if (!lock_task_sighand(task, &flags))
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		return 0;
	memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
	unlock_task_sighand(task, &flags);

	/*
	 * print the file header
	 */
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       seq_printf(m, "%-25s %-20s %-20s %-10s\n",
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		  "Limit", "Soft Limit", "Hard Limit", "Units");
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	for (i = 0; i < RLIM_NLIMITS; i++) {
		if (rlim[i].rlim_cur == RLIM_INFINITY)
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			seq_printf(m, "%-25s %-20s ",
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				   lnames[i].name, "unlimited");
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		else
597
			seq_printf(m, "%-25s %-20lu ",
598
				   lnames[i].name, rlim[i].rlim_cur);
599 600

		if (rlim[i].rlim_max == RLIM_INFINITY)
601
			seq_printf(m, "%-20s ", "unlimited");
602
		else
603
			seq_printf(m, "%-20lu ", rlim[i].rlim_max);
604 605

		if (lnames[i].unit)
606
			seq_printf(m, "%-10s\n", lnames[i].unit);
607
		else
608
			seq_putc(m, '\n');
609 610
	}

611
	return 0;
612 613
}

R
Roland McGrath 已提交
614
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
615 616
static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
			    struct pid *pid, struct task_struct *task)
R
Roland McGrath 已提交
617 618 619
{
	long nr;
	unsigned long args[6], sp, pc;
620 621 622
	int res;

	res = lock_trace(task);
623 624
	if (res)
		return res;
R
Roland McGrath 已提交
625 626

	if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
627
		seq_puts(m, "running\n");
628
	else if (nr < 0)
629
		seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
630
	else
631
		seq_printf(m,
R
Roland McGrath 已提交
632 633 634 635
		       "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
		       nr,
		       args[0], args[1], args[2], args[3], args[4], args[5],
		       sp, pc);
636
	unlock_trace(task);
637 638

	return 0;
R
Roland McGrath 已提交
639 640 641
}
#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */

L
Linus Torvalds 已提交
642 643 644 645 646
/************************************************************************/
/*                       Here the fs part begins                        */
/************************************************************************/

/* permission checks */
647
static int proc_fd_access_allowed(struct inode *inode)
L
Linus Torvalds 已提交
648
{
649 650
	struct task_struct *task;
	int allowed = 0;
651 652 653
	/* Allow access to a task's file descriptors if it is us or we
	 * may use ptrace attach to the process and find out that
	 * information.
654 655
	 */
	task = get_proc_task(inode);
656
	if (task) {
657
		allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
658
		put_task_struct(task);
659
	}
660
	return allowed;
L
Linus Torvalds 已提交
661 662
}

663
int proc_setattr(struct dentry *dentry, struct iattr *attr)
664 665
{
	int error;
666
	struct inode *inode = d_inode(dentry);
667 668 669 670

	if (attr->ia_valid & ATTR_MODE)
		return -EPERM;

671
	error = setattr_prepare(dentry, attr);
C
Christoph Hellwig 已提交
672 673 674 675 676 677
	if (error)
		return error;

	setattr_copy(inode, attr);
	mark_inode_dirty(inode);
	return 0;
678 679
}

680 681 682 683 684 685 686 687 688 689 690 691
/*
 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
 * or euid/egid (for hide_pid_min=2)?
 */
static bool has_pid_permissions(struct pid_namespace *pid,
				 struct task_struct *task,
				 int hide_pid_min)
{
	if (pid->hide_pid < hide_pid_min)
		return true;
	if (in_group_p(pid->pid_gid))
		return true;
692
	return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
693 694 695 696 697 698 699 700 701 702
}


static int proc_pid_permission(struct inode *inode, int mask)
{
	struct pid_namespace *pid = inode->i_sb->s_fs_info;
	struct task_struct *task;
	bool has_perms;

	task = get_proc_task(inode);
703 704
	if (!task)
		return -ESRCH;
705
	has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS);
706 707 708
	put_task_struct(task);

	if (!has_perms) {
709
		if (pid->hide_pid == HIDEPID_INVISIBLE) {
710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725
			/*
			 * Let's make getdents(), stat(), and open()
			 * consistent with each other.  If a process
			 * may not stat() a file, it shouldn't be seen
			 * in procfs at all.
			 */
			return -ENOENT;
		}

		return -EPERM;
	}
	return generic_permission(inode, mask);
}



726
static const struct inode_operations proc_def_inode_operations = {
727 728 729
	.setattr	= proc_setattr,
};

730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751
static int proc_single_show(struct seq_file *m, void *v)
{
	struct inode *inode = m->private;
	struct pid_namespace *ns;
	struct pid *pid;
	struct task_struct *task;
	int ret;

	ns = inode->i_sb->s_fs_info;
	pid = proc_pid(inode);
	task = get_pid_task(pid, PIDTYPE_PID);
	if (!task)
		return -ESRCH;

	ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);

	put_task_struct(task);
	return ret;
}

static int proc_single_open(struct inode *inode, struct file *filp)
{
J
Jovi Zhang 已提交
752
	return single_open(filp, proc_single_show, inode);
753 754 755 756 757 758 759 760 761
}

static const struct file_operations proc_single_file_operations = {
	.open		= proc_single_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

O
Oleg Nesterov 已提交
762 763

struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
L
Linus Torvalds 已提交
764
{
O
Oleg Nesterov 已提交
765 766
	struct task_struct *task = get_proc_task(inode);
	struct mm_struct *mm = ERR_PTR(-ESRCH);
767

O
Oleg Nesterov 已提交
768
	if (task) {
769
		mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
O
Oleg Nesterov 已提交
770
		put_task_struct(task);
771

O
Oleg Nesterov 已提交
772 773
		if (!IS_ERR_OR_NULL(mm)) {
			/* ensure this mm_struct can't be freed */
V
Vegard Nossum 已提交
774
			mmgrab(mm);
O
Oleg Nesterov 已提交
775 776 777 778 779 780 781 782 783 784 785
			/* but do not pin its memory */
			mmput(mm);
		}
	}

	return mm;
}

static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
{
	struct mm_struct *mm = proc_mem_open(inode, mode);
786 787 788 789 790

	if (IS_ERR(mm))
		return PTR_ERR(mm);

	file->private_data = mm;
L
Linus Torvalds 已提交
791 792 793
	return 0;
}

794 795
static int mem_open(struct inode *inode, struct file *file)
{
796 797 798 799 800 801
	int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);

	/* OK to pass negative loff_t, we can catch out-of-range */
	file->f_mode |= FMODE_UNSIGNED_OFFSET;

	return ret;
802 803
}

804 805
static ssize_t mem_rw(struct file *file, char __user *buf,
			size_t count, loff_t *ppos, int write)
L
Linus Torvalds 已提交
806
{
807
	struct mm_struct *mm = file->private_data;
808 809
	unsigned long addr = *ppos;
	ssize_t copied;
L
Linus Torvalds 已提交
810
	char *page;
811
	unsigned int flags;
L
Linus Torvalds 已提交
812

813 814
	if (!mm)
		return 0;
815

816
	page = (char *)__get_free_page(GFP_KERNEL);
817
	if (!page)
818
		return -ENOMEM;
L
Linus Torvalds 已提交
819

820
	copied = 0;
V
Vegard Nossum 已提交
821
	if (!mmget_not_zero(mm))
822 823
		goto free;

L
Linus Torvalds 已提交
824
	flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
825

L
Linus Torvalds 已提交
826
	while (count > 0) {
827
		int this_len = min_t(int, count, PAGE_SIZE);
L
Linus Torvalds 已提交
828

829
		if (write && copy_from_user(page, buf, this_len)) {
L
Linus Torvalds 已提交
830 831 832
			copied = -EFAULT;
			break;
		}
833

834
		this_len = access_remote_vm(mm, addr, page, this_len, flags);
835
		if (!this_len) {
L
Linus Torvalds 已提交
836 837 838 839
			if (!copied)
				copied = -EIO;
			break;
		}
840 841 842 843 844 845 846 847 848 849

		if (!write && copy_to_user(buf, page, this_len)) {
			copied = -EFAULT;
			break;
		}

		buf += this_len;
		addr += this_len;
		copied += this_len;
		count -= this_len;
L
Linus Torvalds 已提交
850
	}
851
	*ppos = addr;
852

853 854
	mmput(mm);
free:
855
	free_page((unsigned long) page);
L
Linus Torvalds 已提交
856 857 858
	return copied;
}

859 860 861 862 863 864 865 866 867 868 869 870
static ssize_t mem_read(struct file *file, char __user *buf,
			size_t count, loff_t *ppos)
{
	return mem_rw(file, buf, count, ppos, 0);
}

static ssize_t mem_write(struct file *file, const char __user *buf,
			 size_t count, loff_t *ppos)
{
	return mem_rw(file, (char __user*)buf, count, ppos, 1);
}

871
loff_t mem_lseek(struct file *file, loff_t offset, int orig)
L
Linus Torvalds 已提交
872 873 874 875 876 877 878 879 880 881 882 883 884 885 886
{
	switch (orig) {
	case 0:
		file->f_pos = offset;
		break;
	case 1:
		file->f_pos += offset;
		break;
	default:
		return -EINVAL;
	}
	force_successful_syscall_return();
	return file->f_pos;
}

887 888 889
static int mem_release(struct inode *inode, struct file *file)
{
	struct mm_struct *mm = file->private_data;
890
	if (mm)
891
		mmdrop(mm);
892 893 894
	return 0;
}

895
static const struct file_operations proc_mem_operations = {
L
Linus Torvalds 已提交
896 897 898 899
	.llseek		= mem_lseek,
	.read		= mem_read,
	.write		= mem_write,
	.open		= mem_open,
900
	.release	= mem_release,
L
Linus Torvalds 已提交
901 902
};

903 904 905 906 907
static int environ_open(struct inode *inode, struct file *file)
{
	return __mem_open(inode, file, PTRACE_MODE_READ);
}

908 909 910 911 912
static ssize_t environ_read(struct file *file, char __user *buf,
			size_t count, loff_t *ppos)
{
	char *page;
	unsigned long src = *ppos;
913 914
	int ret = 0;
	struct mm_struct *mm = file->private_data;
915
	unsigned long env_start, env_end;
916

917 918
	/* Ensure the process spawned far enough to have an environment. */
	if (!mm || !mm->env_end)
919
		return 0;
920

921
	page = (char *)__get_free_page(GFP_KERNEL);
922
	if (!page)
923
		return -ENOMEM;
924

A
Al Viro 已提交
925
	ret = 0;
V
Vegard Nossum 已提交
926
	if (!mmget_not_zero(mm))
927
		goto free;
928 929 930 931 932 933

	down_read(&mm->mmap_sem);
	env_start = mm->env_start;
	env_end = mm->env_end;
	up_read(&mm->mmap_sem);

934
	while (count > 0) {
935 936
		size_t this_len, max_len;
		int retval;
937

938
		if (src >= (env_end - env_start))
939 940
			break;

941
		this_len = env_end - (env_start + src);
942 943 944

		max_len = min_t(size_t, PAGE_SIZE, count);
		this_len = min(max_len, this_len);
945

946
		retval = access_remote_vm(mm, (env_start + src), page, this_len, 0);
947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964

		if (retval <= 0) {
			ret = retval;
			break;
		}

		if (copy_to_user(buf, page, retval)) {
			ret = -EFAULT;
			break;
		}

		ret += retval;
		src += retval;
		buf += retval;
		count -= retval;
	}
	*ppos = src;
	mmput(mm);
965 966

free:
967 968 969 970 971
	free_page((unsigned long) page);
	return ret;
}

static const struct file_operations proc_environ_operations = {
972
	.open		= environ_open,
973
	.read		= environ_read,
974
	.llseek		= generic_file_llseek,
975
	.release	= mem_release,
976 977
};

A
Al Viro 已提交
978 979 980 981 982 983 984 985 986 987
static int auxv_open(struct inode *inode, struct file *file)
{
	return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
}

static ssize_t auxv_read(struct file *file, char __user *buf,
			size_t count, loff_t *ppos)
{
	struct mm_struct *mm = file->private_data;
	unsigned int nwords = 0;
988 989 990

	if (!mm)
		return 0;
A
Al Viro 已提交
991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004
	do {
		nwords += 2;
	} while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
	return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
				       nwords * sizeof(mm->saved_auxv[0]));
}

static const struct file_operations proc_auxv_operations = {
	.open		= auxv_open,
	.read		= auxv_read,
	.llseek		= generic_file_llseek,
	.release	= mem_release,
};

1005 1006 1007
static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
			    loff_t *ppos)
{
A
Al Viro 已提交
1008
	struct task_struct *task = get_proc_task(file_inode(file));
1009 1010 1011 1012 1013 1014
	char buffer[PROC_NUMBUF];
	int oom_adj = OOM_ADJUST_MIN;
	size_t len;

	if (!task)
		return -ESRCH;
1015 1016 1017 1018 1019
	if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
		oom_adj = OOM_ADJUST_MAX;
	else
		oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
			  OOM_SCORE_ADJ_MAX;
1020 1021 1022 1023 1024
	put_task_struct(task);
	len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
	return simple_read_from_buffer(buf, count, ppos, buffer, len);
}

1025 1026 1027
static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
{
	static DEFINE_MUTEX(oom_adj_mutex);
1028
	struct mm_struct *mm = NULL;
1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057
	struct task_struct *task;
	int err = 0;

	task = get_proc_task(file_inode(file));
	if (!task)
		return -ESRCH;

	mutex_lock(&oom_adj_mutex);
	if (legacy) {
		if (oom_adj < task->signal->oom_score_adj &&
				!capable(CAP_SYS_RESOURCE)) {
			err = -EACCES;
			goto err_unlock;
		}
		/*
		 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
		 * /proc/pid/oom_score_adj instead.
		 */
		pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
			  current->comm, task_pid_nr(current), task_pid_nr(task),
			  task_pid_nr(task));
	} else {
		if ((short)oom_adj < task->signal->oom_score_adj_min &&
				!capable(CAP_SYS_RESOURCE)) {
			err = -EACCES;
			goto err_unlock;
		}
	}

1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068
	/*
	 * Make sure we will check other processes sharing the mm if this is
	 * not vfrok which wants its own oom_score_adj.
	 * pin the mm so it doesn't go away and get reused after task_unlock
	 */
	if (!task->vfork_done) {
		struct task_struct *p = find_lock_task_mm(task);

		if (p) {
			if (atomic_read(&p->mm->mm_users) > 1) {
				mm = p->mm;
V
Vegard Nossum 已提交
1069
				mmgrab(mm);
1070 1071 1072 1073 1074
			}
			task_unlock(p);
		}
	}

1075 1076 1077 1078
	task->signal->oom_score_adj = oom_adj;
	if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
		task->signal->oom_score_adj_min = (short)oom_adj;
	trace_oom_score_adj_update(task);
1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106

	if (mm) {
		struct task_struct *p;

		rcu_read_lock();
		for_each_process(p) {
			if (same_thread_group(task, p))
				continue;

			/* do not touch kernel threads or the global init */
			if (p->flags & PF_KTHREAD || is_global_init(p))
				continue;

			task_lock(p);
			if (!p->vfork_done && process_shares_mm(p, mm)) {
				pr_info("updating oom_score_adj for %d (%s) from %d to %d because it shares mm with %d (%s). Report if this is unexpected.\n",
						task_pid_nr(p), p->comm,
						p->signal->oom_score_adj, oom_adj,
						task_pid_nr(task), task->comm);
				p->signal->oom_score_adj = oom_adj;
				if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
					p->signal->oom_score_adj_min = (short)oom_adj;
			}
			task_unlock(p);
		}
		rcu_read_unlock();
		mmdrop(mm);
	}
1107 1108 1109 1110 1111
err_unlock:
	mutex_unlock(&oom_adj_mutex);
	put_task_struct(task);
	return err;
}
1112

1113 1114 1115 1116 1117 1118 1119 1120 1121 1122
/*
 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
 * kernels.  The effective policy is defined by oom_score_adj, which has a
 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
 * Processes that become oom disabled via oom_adj will still be oom disabled
 * with this implementation.
 *
 * oom_adj cannot be removed since existing userspace binaries use it.
 */
1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155
static ssize_t oom_adj_write(struct file *file, const char __user *buf,
			     size_t count, loff_t *ppos)
{
	char buffer[PROC_NUMBUF];
	int oom_adj;
	int err;

	memset(buffer, 0, sizeof(buffer));
	if (count > sizeof(buffer) - 1)
		count = sizeof(buffer) - 1;
	if (copy_from_user(buffer, buf, count)) {
		err = -EFAULT;
		goto out;
	}

	err = kstrtoint(strstrip(buffer), 0, &oom_adj);
	if (err)
		goto out;
	if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
	     oom_adj != OOM_DISABLE) {
		err = -EINVAL;
		goto out;
	}

	/*
	 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
	 * value is always attainable.
	 */
	if (oom_adj == OOM_ADJUST_MAX)
		oom_adj = OOM_SCORE_ADJ_MAX;
	else
		oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;

1156
	err = __set_oom_adj(file, oom_adj, true);
1157 1158 1159 1160 1161 1162 1163 1164 1165 1166
out:
	return err < 0 ? err : count;
}

static const struct file_operations proc_oom_adj_operations = {
	.read		= oom_adj_read,
	.write		= oom_adj_write,
	.llseek		= generic_file_llseek,
};

D
David Rientjes 已提交
1167 1168 1169
static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
					size_t count, loff_t *ppos)
{
A
Al Viro 已提交
1170
	struct task_struct *task = get_proc_task(file_inode(file));
D
David Rientjes 已提交
1171
	char buffer[PROC_NUMBUF];
1172
	short oom_score_adj = OOM_SCORE_ADJ_MIN;
D
David Rientjes 已提交
1173 1174 1175 1176
	size_t len;

	if (!task)
		return -ESRCH;
1177
	oom_score_adj = task->signal->oom_score_adj;
D
David Rientjes 已提交
1178
	put_task_struct(task);
1179
	len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
D
David Rientjes 已提交
1180 1181 1182 1183 1184 1185 1186
	return simple_read_from_buffer(buf, count, ppos, buffer, len);
}

static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
					size_t count, loff_t *ppos)
{
	char buffer[PROC_NUMBUF];
A
Alexey Dobriyan 已提交
1187
	int oom_score_adj;
D
David Rientjes 已提交
1188 1189 1190 1191 1192
	int err;

	memset(buffer, 0, sizeof(buffer));
	if (count > sizeof(buffer) - 1)
		count = sizeof(buffer) - 1;
1193 1194 1195 1196
	if (copy_from_user(buffer, buf, count)) {
		err = -EFAULT;
		goto out;
	}
D
David Rientjes 已提交
1197

A
Alexey Dobriyan 已提交
1198
	err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
D
David Rientjes 已提交
1199
	if (err)
1200
		goto out;
D
David Rientjes 已提交
1201
	if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1202 1203 1204 1205
			oom_score_adj > OOM_SCORE_ADJ_MAX) {
		err = -EINVAL;
		goto out;
	}
D
David Rientjes 已提交
1206

1207
	err = __set_oom_adj(file, oom_score_adj, false);
1208 1209
out:
	return err < 0 ? err : count;
D
David Rientjes 已提交
1210 1211 1212 1213 1214
}

static const struct file_operations proc_oom_score_adj_operations = {
	.read		= oom_score_adj_read,
	.write		= oom_score_adj_write,
1215
	.llseek		= default_llseek,
D
David Rientjes 已提交
1216 1217
};

L
Linus Torvalds 已提交
1218
#ifdef CONFIG_AUDITSYSCALL
1219
#define TMPBUFLEN 11
L
Linus Torvalds 已提交
1220 1221 1222
static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
				  size_t count, loff_t *ppos)
{
A
Al Viro 已提交
1223
	struct inode * inode = file_inode(file);
1224
	struct task_struct *task = get_proc_task(inode);
L
Linus Torvalds 已提交
1225 1226 1227
	ssize_t length;
	char tmpbuf[TMPBUFLEN];

1228 1229
	if (!task)
		return -ESRCH;
L
Linus Torvalds 已提交
1230
	length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1231 1232
			   from_kuid(file->f_cred->user_ns,
				     audit_get_loginuid(task)));
1233
	put_task_struct(task);
L
Linus Torvalds 已提交
1234 1235 1236 1237 1238 1239
	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}

static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
				   size_t count, loff_t *ppos)
{
A
Al Viro 已提交
1240
	struct inode * inode = file_inode(file);
L
Linus Torvalds 已提交
1241
	uid_t loginuid;
1242
	kuid_t kloginuid;
1243
	int rv;
L
Linus Torvalds 已提交
1244

1245 1246 1247
	rcu_read_lock();
	if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
		rcu_read_unlock();
L
Linus Torvalds 已提交
1248
		return -EPERM;
1249 1250
	}
	rcu_read_unlock();
L
Linus Torvalds 已提交
1251 1252 1253 1254 1255 1256

	if (*ppos != 0) {
		/* No partial writes. */
		return -EINVAL;
	}

1257 1258 1259
	rv = kstrtou32_from_user(buf, count, 10, &loginuid);
	if (rv < 0)
		return rv;
1260 1261 1262 1263 1264 1265

	/* is userspace tring to explicitly UNSET the loginuid? */
	if (loginuid == AUDIT_UID_UNSET) {
		kloginuid = INVALID_UID;
	} else {
		kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1266 1267
		if (!uid_valid(kloginuid))
			return -EINVAL;
1268 1269
	}

1270 1271 1272 1273
	rv = audit_set_loginuid(kloginuid);
	if (rv < 0)
		return rv;
	return count;
L
Linus Torvalds 已提交
1274 1275
}

1276
static const struct file_operations proc_loginuid_operations = {
L
Linus Torvalds 已提交
1277 1278
	.read		= proc_loginuid_read,
	.write		= proc_loginuid_write,
1279
	.llseek		= generic_file_llseek,
L
Linus Torvalds 已提交
1280
};
1281 1282 1283 1284

static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
				  size_t count, loff_t *ppos)
{
A
Al Viro 已提交
1285
	struct inode * inode = file_inode(file);
1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299
	struct task_struct *task = get_proc_task(inode);
	ssize_t length;
	char tmpbuf[TMPBUFLEN];

	if (!task)
		return -ESRCH;
	length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
				audit_get_sessionid(task));
	put_task_struct(task);
	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}

static const struct file_operations proc_sessionid_operations = {
	.read		= proc_sessionid_read,
1300
	.llseek		= generic_file_llseek,
1301
};
L
Linus Torvalds 已提交
1302 1303
#endif

1304 1305 1306 1307
#ifdef CONFIG_FAULT_INJECTION
static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
				      size_t count, loff_t *ppos)
{
A
Al Viro 已提交
1308
	struct task_struct *task = get_proc_task(file_inode(file));
1309 1310 1311 1312 1313 1314 1315 1316 1317 1318
	char buffer[PROC_NUMBUF];
	size_t len;
	int make_it_fail;

	if (!task)
		return -ESRCH;
	make_it_fail = task->make_it_fail;
	put_task_struct(task);

	len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1319 1320

	return simple_read_from_buffer(buf, count, ppos, buffer, len);
1321 1322 1323 1324 1325 1326
}

static ssize_t proc_fault_inject_write(struct file * file,
			const char __user * buf, size_t count, loff_t *ppos)
{
	struct task_struct *task;
1327
	char buffer[PROC_NUMBUF];
1328
	int make_it_fail;
1329
	int rv;
1330 1331 1332 1333 1334 1335 1336 1337

	if (!capable(CAP_SYS_RESOURCE))
		return -EPERM;
	memset(buffer, 0, sizeof(buffer));
	if (count > sizeof(buffer) - 1)
		count = sizeof(buffer) - 1;
	if (copy_from_user(buffer, buf, count))
		return -EFAULT;
1338 1339 1340
	rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
	if (rv < 0)
		return rv;
1341 1342 1343
	if (make_it_fail < 0 || make_it_fail > 1)
		return -EINVAL;

A
Al Viro 已提交
1344
	task = get_proc_task(file_inode(file));
1345 1346 1347 1348
	if (!task)
		return -ESRCH;
	task->make_it_fail = make_it_fail;
	put_task_struct(task);
1349 1350

	return count;
1351 1352
}

1353
static const struct file_operations proc_fault_inject_operations = {
1354 1355
	.read		= proc_fault_inject_read,
	.write		= proc_fault_inject_write,
1356
	.llseek		= generic_file_llseek,
1357
};
1358 1359 1360 1361 1362

static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
				   size_t count, loff_t *ppos)
{
	struct task_struct *task;
1363 1364
	int err;
	unsigned int n;
1365

1366 1367 1368 1369
	err = kstrtouint_from_user(buf, count, 0, &n);
	if (err)
		return err;

1370 1371 1372
	task = get_proc_task(file_inode(file));
	if (!task)
		return -ESRCH;
1373
	task->fail_nth = n;
1374
	put_task_struct(task);
1375

1376 1377 1378 1379 1380 1381 1382
	return count;
}

static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
				  size_t count, loff_t *ppos)
{
	struct task_struct *task;
1383 1384
	char numbuf[PROC_NUMBUF];
	ssize_t len;
1385 1386 1387 1388

	task = get_proc_task(file_inode(file));
	if (!task)
		return -ESRCH;
1389
	len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1390
	len = simple_read_from_buffer(buf, count, ppos, numbuf, len);
1391
	put_task_struct(task);
1392 1393

	return len;
1394 1395 1396 1397 1398 1399
}

static const struct file_operations proc_fail_nth_operations = {
	.read		= proc_fail_nth_read,
	.write		= proc_fail_nth_write,
};
1400 1401
#endif

A
Arjan van de Ven 已提交
1402

I
Ingo Molnar 已提交
1403 1404 1405 1406 1407 1408 1409
#ifdef CONFIG_SCHED_DEBUG
/*
 * Print out various scheduling related per-task fields:
 */
static int sched_show(struct seq_file *m, void *v)
{
	struct inode *inode = m->private;
1410
	struct pid_namespace *ns = inode->i_sb->s_fs_info;
I
Ingo Molnar 已提交
1411 1412 1413 1414 1415
	struct task_struct *p;

	p = get_proc_task(inode);
	if (!p)
		return -ESRCH;
1416
	proc_sched_show_task(p, ns, m);
I
Ingo Molnar 已提交
1417 1418 1419 1420 1421 1422 1423 1424 1425 1426

	put_task_struct(p);

	return 0;
}

static ssize_t
sched_write(struct file *file, const char __user *buf,
	    size_t count, loff_t *offset)
{
A
Al Viro 已提交
1427
	struct inode *inode = file_inode(file);
I
Ingo Molnar 已提交
1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441
	struct task_struct *p;

	p = get_proc_task(inode);
	if (!p)
		return -ESRCH;
	proc_sched_set_task(p);

	put_task_struct(p);

	return count;
}

static int sched_open(struct inode *inode, struct file *filp)
{
J
Jovi Zhang 已提交
1442
	return single_open(filp, sched_show, inode);
I
Ingo Molnar 已提交
1443 1444 1445 1446 1447 1448 1449
}

static const struct file_operations proc_pid_sched_operations = {
	.open		= sched_open,
	.read		= seq_read,
	.write		= sched_write,
	.llseek		= seq_lseek,
1450
	.release	= single_release,
I
Ingo Molnar 已提交
1451 1452 1453 1454
};

#endif

1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477
#ifdef CONFIG_SCHED_AUTOGROUP
/*
 * Print out autogroup related information:
 */
static int sched_autogroup_show(struct seq_file *m, void *v)
{
	struct inode *inode = m->private;
	struct task_struct *p;

	p = get_proc_task(inode);
	if (!p)
		return -ESRCH;
	proc_sched_autogroup_show_task(p, m);

	put_task_struct(p);

	return 0;
}

static ssize_t
sched_autogroup_write(struct file *file, const char __user *buf,
	    size_t count, loff_t *offset)
{
A
Al Viro 已提交
1478
	struct inode *inode = file_inode(file);
1479 1480
	struct task_struct *p;
	char buffer[PROC_NUMBUF];
A
Alexey Dobriyan 已提交
1481
	int nice;
1482 1483 1484 1485 1486 1487 1488 1489
	int err;

	memset(buffer, 0, sizeof(buffer));
	if (count > sizeof(buffer) - 1)
		count = sizeof(buffer) - 1;
	if (copy_from_user(buffer, buf, count))
		return -EFAULT;

A
Alexey Dobriyan 已提交
1490 1491 1492
	err = kstrtoint(strstrip(buffer), 0, &nice);
	if (err < 0)
		return err;
1493 1494 1495 1496 1497

	p = get_proc_task(inode);
	if (!p)
		return -ESRCH;

1498
	err = proc_sched_autogroup_set_nice(p, nice);
1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529
	if (err)
		count = err;

	put_task_struct(p);

	return count;
}

static int sched_autogroup_open(struct inode *inode, struct file *filp)
{
	int ret;

	ret = single_open(filp, sched_autogroup_show, NULL);
	if (!ret) {
		struct seq_file *m = filp->private_data;

		m->private = inode;
	}
	return ret;
}

static const struct file_operations proc_pid_sched_autogroup_operations = {
	.open		= sched_autogroup_open,
	.read		= seq_read,
	.write		= sched_autogroup_write,
	.llseek		= seq_lseek,
	.release	= single_release,
};

#endif /* CONFIG_SCHED_AUTOGROUP */

1530 1531 1532
static ssize_t comm_write(struct file *file, const char __user *buf,
				size_t count, loff_t *offset)
{
A
Al Viro 已提交
1533
	struct inode *inode = file_inode(file);
1534 1535
	struct task_struct *p;
	char buffer[TASK_COMM_LEN];
1536
	const size_t maxlen = sizeof(buffer) - 1;
1537 1538

	memset(buffer, 0, sizeof(buffer));
1539
	if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575
		return -EFAULT;

	p = get_proc_task(inode);
	if (!p)
		return -ESRCH;

	if (same_thread_group(current, p))
		set_task_comm(p, buffer);
	else
		count = -EINVAL;

	put_task_struct(p);

	return count;
}

static int comm_show(struct seq_file *m, void *v)
{
	struct inode *inode = m->private;
	struct task_struct *p;

	p = get_proc_task(inode);
	if (!p)
		return -ESRCH;

	task_lock(p);
	seq_printf(m, "%s\n", p->comm);
	task_unlock(p);

	put_task_struct(p);

	return 0;
}

static int comm_open(struct inode *inode, struct file *filp)
{
J
Jovi Zhang 已提交
1576
	return single_open(filp, comm_show, inode);
1577 1578 1579 1580 1581 1582 1583 1584 1585 1586
}

static const struct file_operations proc_pid_set_comm_operations = {
	.open		= comm_open,
	.read		= seq_read,
	.write		= comm_write,
	.llseek		= seq_lseek,
	.release	= single_release,
};

1587
static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
M
Matt Helsley 已提交
1588 1589 1590 1591
{
	struct task_struct *task;
	struct file *exe_file;

1592
	task = get_proc_task(d_inode(dentry));
M
Matt Helsley 已提交
1593 1594
	if (!task)
		return -ENOENT;
M
Mateusz Guzik 已提交
1595
	exe_file = get_task_exe_file(task);
M
Matt Helsley 已提交
1596 1597 1598 1599 1600 1601 1602 1603 1604 1605
	put_task_struct(task);
	if (exe_file) {
		*exe_path = exe_file->f_path;
		path_get(&exe_file->f_path);
		fput(exe_file);
		return 0;
	} else
		return -ENOENT;
}

1606
static const char *proc_pid_get_link(struct dentry *dentry,
1607 1608
				     struct inode *inode,
				     struct delayed_call *done)
L
Linus Torvalds 已提交
1609
{
1610
	struct path path;
L
Linus Torvalds 已提交
1611 1612
	int error = -EACCES;

1613 1614 1615
	if (!dentry)
		return ERR_PTR(-ECHILD);

1616 1617
	/* Are we allowed to snoop on the tasks file descriptors? */
	if (!proc_fd_access_allowed(inode))
L
Linus Torvalds 已提交
1618 1619
		goto out;

1620 1621 1622 1623
	error = PROC_I(inode)->op.proc_get_link(dentry, &path);
	if (error)
		goto out;

1624
	nd_jump_link(&path);
1625
	return NULL;
L
Linus Torvalds 已提交
1626
out:
1627
	return ERR_PTR(error);
L
Linus Torvalds 已提交
1628 1629
}

1630
static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
L
Linus Torvalds 已提交
1631
{
1632
	char *tmp = (char *)__get_free_page(GFP_KERNEL);
1633
	char *pathname;
L
Linus Torvalds 已提交
1634 1635 1636 1637
	int len;

	if (!tmp)
		return -ENOMEM;
1638

1639
	pathname = d_path(path, tmp, PAGE_SIZE);
1640 1641
	len = PTR_ERR(pathname);
	if (IS_ERR(pathname))
L
Linus Torvalds 已提交
1642
		goto out;
1643
	len = tmp + PAGE_SIZE - 1 - pathname;
L
Linus Torvalds 已提交
1644 1645 1646

	if (len > buflen)
		len = buflen;
1647
	if (copy_to_user(buffer, pathname, len))
L
Linus Torvalds 已提交
1648 1649 1650 1651 1652 1653 1654 1655 1656
		len = -EFAULT;
 out:
	free_page((unsigned long)tmp);
	return len;
}

static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
{
	int error = -EACCES;
1657
	struct inode *inode = d_inode(dentry);
1658
	struct path path;
L
Linus Torvalds 已提交
1659

1660 1661
	/* Are we allowed to snoop on the tasks file descriptors? */
	if (!proc_fd_access_allowed(inode))
L
Linus Torvalds 已提交
1662 1663
		goto out;

1664
	error = PROC_I(inode)->op.proc_get_link(dentry, &path);
L
Linus Torvalds 已提交
1665 1666 1667
	if (error)
		goto out;

1668 1669
	error = do_proc_readlink(&path, buffer, buflen);
	path_put(&path);
L
Linus Torvalds 已提交
1670 1671 1672 1673
out:
	return error;
}

1674
const struct inode_operations proc_pid_link_inode_operations = {
L
Linus Torvalds 已提交
1675
	.readlink	= proc_pid_readlink,
1676
	.get_link	= proc_pid_get_link,
1677
	.setattr	= proc_setattr,
L
Linus Torvalds 已提交
1678 1679
};

1680 1681 1682

/* building an inode */

A
Al Viro 已提交
1683
void task_dump_owner(struct task_struct *task, umode_t mode,
1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734
		     kuid_t *ruid, kgid_t *rgid)
{
	/* Depending on the state of dumpable compute who should own a
	 * proc file for a task.
	 */
	const struct cred *cred;
	kuid_t uid;
	kgid_t gid;

	/* Default to the tasks effective ownership */
	rcu_read_lock();
	cred = __task_cred(task);
	uid = cred->euid;
	gid = cred->egid;
	rcu_read_unlock();

	/*
	 * Before the /proc/pid/status file was created the only way to read
	 * the effective uid of a /process was to stat /proc/pid.  Reading
	 * /proc/pid/status is slow enough that procps and other packages
	 * kept stating /proc/pid.  To keep the rules in /proc simple I have
	 * made this apply to all per process world readable and executable
	 * directories.
	 */
	if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
		struct mm_struct *mm;
		task_lock(task);
		mm = task->mm;
		/* Make non-dumpable tasks owned by some root */
		if (mm) {
			if (get_dumpable(mm) != SUID_DUMP_USER) {
				struct user_namespace *user_ns = mm->user_ns;

				uid = make_kuid(user_ns, 0);
				if (!uid_valid(uid))
					uid = GLOBAL_ROOT_UID;

				gid = make_kgid(user_ns, 0);
				if (!gid_valid(gid))
					gid = GLOBAL_ROOT_GID;
			}
		} else {
			uid = GLOBAL_ROOT_UID;
			gid = GLOBAL_ROOT_GID;
		}
		task_unlock(task);
	}
	*ruid = uid;
	*rgid = gid;
}

1735 1736
struct inode *proc_pid_make_inode(struct super_block * sb,
				  struct task_struct *task, umode_t mode)
1737 1738 1739
{
	struct inode * inode;
	struct proc_inode *ei;
L
Linus Torvalds 已提交
1740

1741
	/* We need a new inode */
L
Linus Torvalds 已提交
1742

1743 1744 1745 1746 1747 1748
	inode = new_inode(sb);
	if (!inode)
		goto out;

	/* Common stuff */
	ei = PROC_I(inode);
1749
	inode->i_mode = mode;
1750
	inode->i_ino = get_next_ino();
1751
	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1752 1753 1754 1755 1756
	inode->i_op = &proc_def_inode_operations;

	/*
	 * grab the reference to task.
	 */
1757
	ei->pid = get_task_pid(task, PIDTYPE_PID);
1758 1759 1760
	if (!ei->pid)
		goto out_unlock;

1761
	task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1762 1763
	security_task_to_inode(task, inode);

L
Linus Torvalds 已提交
1764
out:
1765 1766 1767 1768 1769
	return inode;

out_unlock:
	iput(inode);
	return NULL;
L
Linus Torvalds 已提交
1770 1771
}

1772 1773
int pid_getattr(const struct path *path, struct kstat *stat,
		u32 request_mask, unsigned int query_flags)
L
Linus Torvalds 已提交
1774
{
1775
	struct inode *inode = d_inode(path->dentry);
1776
	struct task_struct *task;
1777
	struct pid_namespace *pid = path->dentry->d_sb->s_fs_info;
1778

1779
	generic_fillattr(inode, stat);
L
Linus Torvalds 已提交
1780

1781
	rcu_read_lock();
1782 1783
	stat->uid = GLOBAL_ROOT_UID;
	stat->gid = GLOBAL_ROOT_GID;
1784 1785
	task = pid_task(proc_pid(inode), PIDTYPE_PID);
	if (task) {
1786
		if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) {
1787 1788 1789 1790 1791 1792 1793
			rcu_read_unlock();
			/*
			 * This doesn't prevent learning whether PID exists,
			 * it only makes getattr() consistent with readdir().
			 */
			return -ENOENT;
		}
1794
		task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
L
Linus Torvalds 已提交
1795
	}
1796
	rcu_read_unlock();
A
Alan Cox 已提交
1797
	return 0;
L
Linus Torvalds 已提交
1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808
}

/* dentry stuff */

/*
 *	Exceptional case: normally we are not allowed to unhash a busy
 * directory. In this case, however, we can do it - no aliasing problems
 * due to the way we treat inodes.
 *
 * Rewrite the inode's ownerships here because the owning task may have
 * performed a setuid(), etc.
1809
 *
L
Linus Torvalds 已提交
1810
 */
1811
int pid_revalidate(struct dentry *dentry, unsigned int flags)
L
Linus Torvalds 已提交
1812
{
1813 1814
	struct inode *inode;
	struct task_struct *task;
1815

1816
	if (flags & LOOKUP_RCU)
1817 1818
		return -ECHILD;

1819
	inode = d_inode(dentry);
1820 1821
	task = get_proc_task(inode);

1822
	if (task) {
1823 1824
		task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);

L
Linus Torvalds 已提交
1825
		inode->i_mode &= ~(S_ISUID | S_ISGID);
L
Linus Torvalds 已提交
1826
		security_task_to_inode(task, inode);
1827
		put_task_struct(task);
L
Linus Torvalds 已提交
1828 1829 1830 1831 1832
		return 1;
	}
	return 0;
}

1833 1834 1835 1836 1837
static inline bool proc_inode_is_dead(struct inode *inode)
{
	return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
}

1838 1839 1840 1841 1842 1843
int pid_delete_dentry(const struct dentry *dentry)
{
	/* Is the task we represent dead?
	 * If so, then don't put the dentry on the lru list,
	 * kill it immediately.
	 */
1844
	return proc_inode_is_dead(d_inode(dentry));
1845 1846
}

1847
const struct dentry_operations pid_dentry_operations =
1848 1849 1850 1851 1852 1853 1854
{
	.d_revalidate	= pid_revalidate,
	.d_delete	= pid_delete_dentry,
};

/* Lookups */

1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866
/*
 * Fill a directory entry.
 *
 * If possible create the dcache entry and derive our inode number and
 * file type from dcache entry.
 *
 * Since all of the proc inode numbers are dynamically generated, the inode
 * numbers do not exist until the inode is cache.  This means creating the
 * the dcache entry in readdir is necessary to keep the inode numbers
 * reported by readdir in sync with the inode numbers reported
 * by stat.
 */
A
Al Viro 已提交
1867
bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1868
	const char *name, int len,
1869
	instantiate_t instantiate, struct task_struct *task, const void *ptr)
1870
{
A
Al Viro 已提交
1871
	struct dentry *child, *dir = file->f_path.dentry;
1872
	struct qstr qname = QSTR_INIT(name, len);
1873
	struct inode *inode;
1874 1875
	unsigned type;
	ino_t ino;
1876

1877
	child = d_hash_and_lookup(dir, &qname);
1878
	if (!child) {
1879 1880 1881
		DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
		child = d_alloc_parallel(dir, &qname, &wq);
		if (IS_ERR(child))
1882
			goto end_instantiate;
1883 1884 1885 1886 1887 1888 1889
		if (d_in_lookup(child)) {
			int err = instantiate(d_inode(dir), child, task, ptr);
			d_lookup_done(child);
			if (err < 0) {
				dput(child);
				goto end_instantiate;
			}
1890 1891
		}
	}
1892
	inode = d_inode(child);
1893 1894
	ino = inode->i_ino;
	type = inode->i_mode >> 12;
1895
	dput(child);
A
Al Viro 已提交
1896
	return dir_emit(ctx, name, len, ino, type);
1897 1898 1899

end_instantiate:
	return dir_emit(ctx, name, len, 1, DT_UNKNOWN);
1900 1901
}

1902 1903 1904 1905 1906 1907 1908
/*
 * dname_to_vma_addr - maps a dentry name into two unsigned longs
 * which represent vma start and end addresses.
 */
static int dname_to_vma_addr(struct dentry *dentry,
			     unsigned long *start, unsigned long *end)
{
1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920
	const char *str = dentry->d_name.name;
	unsigned long long sval, eval;
	unsigned int len;

	len = _parse_integer(str, 16, &sval);
	if (len & KSTRTOX_OVERFLOW)
		return -EINVAL;
	if (sval != (unsigned long)sval)
		return -EINVAL;
	str += len;

	if (*str != '-')
1921
		return -EINVAL;
1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935
	str++;

	len = _parse_integer(str, 16, &eval);
	if (len & KSTRTOX_OVERFLOW)
		return -EINVAL;
	if (eval != (unsigned long)eval)
		return -EINVAL;
	str += len;

	if (*str != '\0')
		return -EINVAL;

	*start = sval;
	*end = eval;
1936 1937 1938 1939

	return 0;
}

1940
static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1941 1942 1943 1944 1945 1946 1947 1948
{
	unsigned long vm_start, vm_end;
	bool exact_vma_exists = false;
	struct mm_struct *mm = NULL;
	struct task_struct *task;
	struct inode *inode;
	int status = 0;

1949
	if (flags & LOOKUP_RCU)
1950 1951
		return -ECHILD;

1952
	inode = d_inode(dentry);
1953 1954 1955 1956
	task = get_proc_task(inode);
	if (!task)
		goto out_notask;

1957
	mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
1958
	if (IS_ERR_OR_NULL(mm))
1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969
		goto out;

	if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
		down_read(&mm->mmap_sem);
		exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
		up_read(&mm->mmap_sem);
	}

	mmput(mm);

	if (exact_vma_exists) {
1970 1971
		task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);

1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987
		security_task_to_inode(task, inode);
		status = 1;
	}

out:
	put_task_struct(task);

out_notask:
	return status;
}

static const struct dentry_operations tid_map_files_dentry_operations = {
	.d_revalidate	= map_files_d_revalidate,
	.d_delete	= pid_delete_dentry,
};

1988
static int map_files_get_link(struct dentry *dentry, struct path *path)
1989 1990 1991 1992 1993 1994 1995 1996
{
	unsigned long vm_start, vm_end;
	struct vm_area_struct *vma;
	struct task_struct *task;
	struct mm_struct *mm;
	int rc;

	rc = -ENOENT;
1997
	task = get_proc_task(d_inode(dentry));
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
	if (!task)
		goto out;

	mm = get_task_mm(task);
	put_task_struct(task);
	if (!mm)
		goto out;

	rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
	if (rc)
		goto out_mmput;

2010
	rc = -ENOENT;
2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026
	down_read(&mm->mmap_sem);
	vma = find_exact_vma(mm, vm_start, vm_end);
	if (vma && vma->vm_file) {
		*path = vma->vm_file->f_path;
		path_get(path);
		rc = 0;
	}
	up_read(&mm->mmap_sem);

out_mmput:
	mmput(mm);
out:
	return rc;
}

struct map_files_info {
2027 2028
	unsigned long	start;
	unsigned long	end;
2029
	fmode_t		mode;
2030 2031
};

2032 2033 2034 2035 2036 2037
/*
 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
 * symlinks may be used to bypass permissions on ancestor directories in the
 * path to the file in question.
 */
static const char *
2038
proc_map_files_get_link(struct dentry *dentry,
2039 2040
			struct inode *inode,
		        struct delayed_call *done)
2041 2042 2043 2044
{
	if (!capable(CAP_SYS_ADMIN))
		return ERR_PTR(-EPERM);

2045
	return proc_pid_get_link(dentry, inode, done);
2046 2047 2048
}

/*
2049
 * Identical to proc_pid_link_inode_operations except for get_link()
2050 2051 2052
 */
static const struct inode_operations proc_map_files_link_inode_operations = {
	.readlink	= proc_pid_readlink,
2053
	.get_link	= proc_map_files_get_link,
2054 2055 2056
	.setattr	= proc_setattr,
};

2057
static int
2058 2059 2060
proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
			   struct task_struct *task, const void *ptr)
{
2061
	fmode_t mode = (fmode_t)(unsigned long)ptr;
2062 2063 2064
	struct proc_inode *ei;
	struct inode *inode;

2065 2066 2067
	inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK |
				    ((mode & FMODE_READ ) ? S_IRUSR : 0) |
				    ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2068
	if (!inode)
2069
		return -ENOENT;
2070 2071

	ei = PROC_I(inode);
2072
	ei->op.proc_get_link = map_files_get_link;
2073

2074
	inode->i_op = &proc_map_files_link_inode_operations;
2075 2076 2077 2078 2079
	inode->i_size = 64;

	d_set_d_op(dentry, &tid_map_files_dentry_operations);
	d_add(dentry, inode);

2080
	return 0;
2081 2082 2083
}

static struct dentry *proc_map_files_lookup(struct inode *dir,
A
Al Viro 已提交
2084
		struct dentry *dentry, unsigned int flags)
2085 2086 2087 2088
{
	unsigned long vm_start, vm_end;
	struct vm_area_struct *vma;
	struct task_struct *task;
2089
	int result;
2090 2091
	struct mm_struct *mm;

2092
	result = -ENOENT;
2093 2094 2095 2096
	task = get_proc_task(dir);
	if (!task)
		goto out;

2097
	result = -EACCES;
2098
	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2099 2100
		goto out_put_task;

2101
	result = -ENOENT;
2102
	if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2103
		goto out_put_task;
2104 2105 2106

	mm = get_task_mm(task);
	if (!mm)
2107
		goto out_put_task;
2108 2109 2110 2111 2112 2113

	down_read(&mm->mmap_sem);
	vma = find_exact_vma(mm, vm_start, vm_end);
	if (!vma)
		goto out_no_vma;

2114 2115 2116
	if (vma->vm_file)
		result = proc_map_files_instantiate(dir, dentry, task,
				(void *)(unsigned long)vma->vm_file->f_mode);
2117 2118 2119 2120 2121 2122 2123

out_no_vma:
	up_read(&mm->mmap_sem);
	mmput(mm);
out_put_task:
	put_task_struct(task);
out:
2124
	return ERR_PTR(result);
2125 2126 2127 2128 2129 2130 2131 2132 2133
}

static const struct inode_operations proc_map_files_inode_operations = {
	.lookup		= proc_map_files_lookup,
	.permission	= proc_fd_permission,
	.setattr	= proc_setattr,
};

static int
A
Al Viro 已提交
2134
proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2135 2136 2137 2138
{
	struct vm_area_struct *vma;
	struct task_struct *task;
	struct mm_struct *mm;
A
Al Viro 已提交
2139 2140 2141 2142
	unsigned long nr_files, pos, i;
	struct flex_array *fa = NULL;
	struct map_files_info info;
	struct map_files_info *p;
2143 2144 2145
	int ret;

	ret = -ENOENT;
A
Al Viro 已提交
2146
	task = get_proc_task(file_inode(file));
2147 2148 2149 2150
	if (!task)
		goto out;

	ret = -EACCES;
2151
	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2152 2153 2154
		goto out_put_task;

	ret = 0;
A
Al Viro 已提交
2155 2156
	if (!dir_emit_dots(file, ctx))
		goto out_put_task;
2157

A
Al Viro 已提交
2158 2159 2160 2161
	mm = get_task_mm(task);
	if (!mm)
		goto out_put_task;
	down_read(&mm->mmap_sem);
2162

A
Al Viro 已提交
2163
	nr_files = 0;
2164

A
Al Viro 已提交
2165 2166 2167 2168 2169 2170 2171 2172 2173
	/*
	 * We need two passes here:
	 *
	 *  1) Collect vmas of mapped files with mmap_sem taken
	 *  2) Release mmap_sem and instantiate entries
	 *
	 * otherwise we get lockdep complained, since filldir()
	 * routine might require mmap_sem taken in might_fault().
	 */
2174

A
Al Viro 已提交
2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190
	for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
		if (vma->vm_file && ++pos > ctx->pos)
			nr_files++;
	}

	if (nr_files) {
		fa = flex_array_alloc(sizeof(info), nr_files,
					GFP_KERNEL);
		if (!fa || flex_array_prealloc(fa, 0, nr_files,
						GFP_KERNEL)) {
			ret = -ENOMEM;
			if (fa)
				flex_array_free(fa);
			up_read(&mm->mmap_sem);
			mmput(mm);
			goto out_put_task;
2191
		}
A
Al Viro 已提交
2192 2193 2194 2195 2196 2197 2198
		for (i = 0, vma = mm->mmap, pos = 2; vma;
				vma = vma->vm_next) {
			if (!vma->vm_file)
				continue;
			if (++pos <= ctx->pos)
				continue;

2199 2200
			info.start = vma->vm_start;
			info.end = vma->vm_end;
A
Al Viro 已提交
2201 2202 2203
			info.mode = vma->vm_file->f_mode;
			if (flex_array_put(fa, i++, &info, GFP_KERNEL))
				BUG();
2204 2205
		}
	}
A
Al Viro 已提交
2206 2207 2208
	up_read(&mm->mmap_sem);

	for (i = 0; i < nr_files; i++) {
2209 2210 2211
		char buf[4 * sizeof(long) + 2];	/* max: %lx-%lx\0 */
		unsigned int len;

A
Al Viro 已提交
2212
		p = flex_array_get(fa, i);
2213
		len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
A
Al Viro 已提交
2214
		if (!proc_fill_cache(file, ctx,
2215
				      buf, len,
A
Al Viro 已提交
2216 2217 2218 2219 2220
				      proc_map_files_instantiate,
				      task,
				      (void *)(unsigned long)p->mode))
			break;
		ctx->pos++;
2221
	}
A
Al Viro 已提交
2222 2223 2224
	if (fa)
		flex_array_free(fa);
	mmput(mm);
2225 2226 2227 2228 2229 2230 2231 2232 2233

out_put_task:
	put_task_struct(task);
out:
	return ret;
}

static const struct file_operations proc_map_files_operations = {
	.read		= generic_read_dir,
2234 2235
	.iterate_shared	= proc_map_files_readdir,
	.llseek		= generic_file_llseek,
2236 2237
};

2238
#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2239 2240 2241 2242
struct timers_private {
	struct pid *pid;
	struct task_struct *task;
	struct sighand_struct *sighand;
2243
	struct pid_namespace *ns;
2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285
	unsigned long flags;
};

static void *timers_start(struct seq_file *m, loff_t *pos)
{
	struct timers_private *tp = m->private;

	tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
	if (!tp->task)
		return ERR_PTR(-ESRCH);

	tp->sighand = lock_task_sighand(tp->task, &tp->flags);
	if (!tp->sighand)
		return ERR_PTR(-ESRCH);

	return seq_list_start(&tp->task->signal->posix_timers, *pos);
}

static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
{
	struct timers_private *tp = m->private;
	return seq_list_next(v, &tp->task->signal->posix_timers, pos);
}

static void timers_stop(struct seq_file *m, void *v)
{
	struct timers_private *tp = m->private;

	if (tp->sighand) {
		unlock_task_sighand(tp->task, &tp->flags);
		tp->sighand = NULL;
	}

	if (tp->task) {
		put_task_struct(tp->task);
		tp->task = NULL;
	}
}

static int show_timer(struct seq_file *m, void *v)
{
	struct k_itimer *timer;
2286 2287
	struct timers_private *tp = m->private;
	int notify;
2288
	static const char * const nstr[] = {
2289 2290 2291 2292
		[SIGEV_SIGNAL] = "signal",
		[SIGEV_NONE] = "none",
		[SIGEV_THREAD] = "thread",
	};
2293 2294

	timer = list_entry((struct list_head *)v, struct k_itimer, list);
2295 2296
	notify = timer->it_sigev_notify;

2297
	seq_printf(m, "ID: %d\n", timer->it_id);
2298
	seq_printf(m, "signal: %d/%px\n",
2299 2300
		   timer->sigq->info.si_signo,
		   timer->sigq->info.si_value.sival_ptr);
2301
	seq_printf(m, "notify: %s/%s.%d\n",
2302 2303 2304
		   nstr[notify & ~SIGEV_THREAD_ID],
		   (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
		   pid_nr_ns(timer->it_pid, tp->ns));
2305
	seq_printf(m, "ClockID: %d\n", timer->it_clock);
2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326

	return 0;
}

static const struct seq_operations proc_timers_seq_ops = {
	.start	= timers_start,
	.next	= timers_next,
	.stop	= timers_stop,
	.show	= show_timer,
};

static int proc_timers_open(struct inode *inode, struct file *file)
{
	struct timers_private *tp;

	tp = __seq_open_private(file, &proc_timers_seq_ops,
			sizeof(struct timers_private));
	if (!tp)
		return -ENOMEM;

	tp->pid = proc_pid(inode);
2327
	tp->ns = inode->i_sb->s_fs_info;
2328 2329 2330 2331 2332 2333 2334 2335 2336
	return 0;
}

static const struct file_operations proc_timers_operations = {
	.open		= proc_timers_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release_private,
};
2337
#endif
2338

2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354
static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
					size_t count, loff_t *offset)
{
	struct inode *inode = file_inode(file);
	struct task_struct *p;
	u64 slack_ns;
	int err;

	err = kstrtoull_from_user(buf, count, 10, &slack_ns);
	if (err < 0)
		return err;

	p = get_proc_task(inode);
	if (!p)
		return -ESRCH;

2355 2356 2357 2358 2359
	if (p != current) {
		if (!capable(CAP_SYS_NICE)) {
			count = -EPERM;
			goto out;
		}
2360

2361 2362 2363 2364 2365
		err = security_task_setscheduler(p);
		if (err) {
			count = err;
			goto out;
		}
2366 2367
	}

2368 2369 2370 2371 2372 2373 2374 2375
	task_lock(p);
	if (slack_ns == 0)
		p->timer_slack_ns = p->default_timer_slack_ns;
	else
		p->timer_slack_ns = slack_ns;
	task_unlock(p);

out:
2376 2377 2378 2379 2380 2381 2382 2383 2384
	put_task_struct(p);

	return count;
}

static int timerslack_ns_show(struct seq_file *m, void *v)
{
	struct inode *inode = m->private;
	struct task_struct *p;
2385
	int err = 0;
2386 2387 2388 2389 2390

	p = get_proc_task(inode);
	if (!p)
		return -ESRCH;

2391
	if (p != current) {
2392

2393 2394 2395 2396 2397 2398 2399 2400
		if (!capable(CAP_SYS_NICE)) {
			err = -EPERM;
			goto out;
		}
		err = security_task_getscheduler(p);
		if (err)
			goto out;
	}
2401

2402 2403 2404 2405 2406
	task_lock(p);
	seq_printf(m, "%llu\n", p->timer_slack_ns);
	task_unlock(p);

out:
2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424
	put_task_struct(p);

	return err;
}

static int timerslack_ns_open(struct inode *inode, struct file *filp)
{
	return single_open(filp, timerslack_ns_show, inode);
}

static const struct file_operations proc_pid_set_timerslack_ns_operations = {
	.open		= timerslack_ns_open,
	.read		= seq_read,
	.write		= timerslack_ns_write,
	.llseek		= seq_lseek,
	.release	= single_release,
};

2425
static int proc_pident_instantiate(struct inode *dir,
2426
	struct dentry *dentry, struct task_struct *task, const void *ptr)
2427
{
2428
	const struct pid_entry *p = ptr;
2429 2430 2431
	struct inode *inode;
	struct proc_inode *ei;

2432
	inode = proc_pid_make_inode(dir->i_sb, task, p->mode);
2433 2434 2435 2436 2437
	if (!inode)
		goto out;

	ei = PROC_I(inode);
	if (S_ISDIR(inode->i_mode))
M
Miklos Szeredi 已提交
2438
		set_nlink(inode, 2);	/* Use getattr to fix if necessary */
2439 2440 2441 2442 2443
	if (p->iop)
		inode->i_op = p->iop;
	if (p->fop)
		inode->i_fop = p->fop;
	ei->op = p->op;
2444
	d_set_d_op(dentry, &pid_dentry_operations);
2445 2446
	d_add(dentry, inode);
	/* Close the race of the process dying before we return the dentry */
2447
	if (pid_revalidate(dentry, 0))
2448
		return 0;
2449
out:
2450
	return -ENOENT;
2451 2452
}

L
Linus Torvalds 已提交
2453 2454
static struct dentry *proc_pident_lookup(struct inode *dir, 
					 struct dentry *dentry,
2455
					 const struct pid_entry *ents,
2456
					 unsigned int nents)
L
Linus Torvalds 已提交
2457
{
2458
	int error;
2459
	struct task_struct *task = get_proc_task(dir);
2460
	const struct pid_entry *p, *last;
L
Linus Torvalds 已提交
2461

2462
	error = -ENOENT;
L
Linus Torvalds 已提交
2463

2464 2465
	if (!task)
		goto out_no_task;
L
Linus Torvalds 已提交
2466

2467 2468 2469 2470
	/*
	 * Yes, it does not scale. And it should not. Don't add
	 * new entries into /proc/<tgid>/ without very good reasons.
	 */
2471 2472
	last = &ents[nents];
	for (p = ents; p < last; p++) {
L
Linus Torvalds 已提交
2473 2474 2475 2476 2477
		if (p->len != dentry->d_name.len)
			continue;
		if (!memcmp(dentry->d_name.name, p->name, p->len))
			break;
	}
2478
	if (p >= last)
L
Linus Torvalds 已提交
2479 2480
		goto out;

2481
	error = proc_pident_instantiate(dir, dentry, task, p);
L
Linus Torvalds 已提交
2482
out:
2483 2484
	put_task_struct(task);
out_no_task:
2485
	return ERR_PTR(error);
L
Linus Torvalds 已提交
2486 2487
}

A
Al Viro 已提交
2488
static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2489
		const struct pid_entry *ents, unsigned int nents)
2490
{
A
Al Viro 已提交
2491 2492
	struct task_struct *task = get_proc_task(file_inode(file));
	const struct pid_entry *p;
2493 2494

	if (!task)
A
Al Viro 已提交
2495
		return -ENOENT;
2496

A
Al Viro 已提交
2497 2498 2499 2500 2501
	if (!dir_emit_dots(file, ctx))
		goto out;

	if (ctx->pos >= nents + 2)
		goto out;
2502

2503
	for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
A
Al Viro 已提交
2504 2505 2506 2507 2508
		if (!proc_fill_cache(file, ctx, p->name, p->len,
				proc_pident_instantiate, task, p))
			break;
		ctx->pos++;
	}
2509
out:
2510
	put_task_struct(task);
A
Al Viro 已提交
2511
	return 0;
L
Linus Torvalds 已提交
2512 2513
}

2514 2515 2516 2517
#ifdef CONFIG_SECURITY
static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
				  size_t count, loff_t *ppos)
{
A
Al Viro 已提交
2518
	struct inode * inode = file_inode(file);
2519
	char *p = NULL;
2520 2521 2522 2523
	ssize_t length;
	struct task_struct *task = get_proc_task(inode);

	if (!task)
2524
		return -ESRCH;
2525 2526

	length = security_getprocattr(task,
2527
				      (char*)file->f_path.dentry->d_name.name,
2528
				      &p);
2529
	put_task_struct(task);
2530 2531 2532
	if (length > 0)
		length = simple_read_from_buffer(buf, count, ppos, p, length);
	kfree(p);
2533
	return length;
L
Linus Torvalds 已提交
2534 2535
}

2536 2537 2538
static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
				   size_t count, loff_t *ppos)
{
A
Al Viro 已提交
2539
	struct inode * inode = file_inode(file);
2540
	void *page;
2541 2542 2543 2544 2545 2546
	ssize_t length;
	struct task_struct *task = get_proc_task(inode);

	length = -ESRCH;
	if (!task)
		goto out_no_task;
2547 2548 2549 2550 2551 2552

	/* A task may only write its own attributes. */
	length = -EACCES;
	if (current != task)
		goto out;

2553 2554 2555 2556 2557 2558 2559 2560
	if (count > PAGE_SIZE)
		count = PAGE_SIZE;

	/* No partial writes. */
	length = -EINVAL;
	if (*ppos != 0)
		goto out;

2561 2562 2563
	page = memdup_user(buf, count);
	if (IS_ERR(page)) {
		length = PTR_ERR(page);
2564
		goto out;
2565
	}
2566

2567
	/* Guard against adverse ptrace interaction */
2568
	length = mutex_lock_interruptible(&current->signal->cred_guard_mutex);
2569 2570 2571
	if (length < 0)
		goto out_free;

2572
	length = security_setprocattr(file->f_path.dentry->d_name.name,
2573
				      page, count);
2574
	mutex_unlock(&current->signal->cred_guard_mutex);
2575
out_free:
2576
	kfree(page);
2577 2578 2579 2580 2581 2582
out:
	put_task_struct(task);
out_no_task:
	return length;
}

2583
static const struct file_operations proc_pid_attr_operations = {
2584 2585
	.read		= proc_pid_attr_read,
	.write		= proc_pid_attr_write,
2586
	.llseek		= generic_file_llseek,
2587 2588
};

2589
static const struct pid_entry attr_dir_stuff[] = {
A
Alexey Dobriyan 已提交
2590 2591 2592 2593 2594 2595
	REG("current",    S_IRUGO|S_IWUGO, proc_pid_attr_operations),
	REG("prev",       S_IRUGO,	   proc_pid_attr_operations),
	REG("exec",       S_IRUGO|S_IWUGO, proc_pid_attr_operations),
	REG("fscreate",   S_IRUGO|S_IWUGO, proc_pid_attr_operations),
	REG("keycreate",  S_IRUGO|S_IWUGO, proc_pid_attr_operations),
	REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2596 2597
};

A
Al Viro 已提交
2598
static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2599
{
A
Al Viro 已提交
2600 2601
	return proc_pident_readdir(file, ctx, 
				   attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2602 2603
}

2604
static const struct file_operations proc_attr_dir_operations = {
L
Linus Torvalds 已提交
2605
	.read		= generic_read_dir,
2606 2607
	.iterate_shared	= proc_attr_dir_readdir,
	.llseek		= generic_file_llseek,
L
Linus Torvalds 已提交
2608 2609
};

2610
static struct dentry *proc_attr_dir_lookup(struct inode *dir,
A
Al Viro 已提交
2611
				struct dentry *dentry, unsigned int flags)
2612
{
2613 2614
	return proc_pident_lookup(dir, dentry,
				  attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2615 2616
}

2617
static const struct inode_operations proc_attr_dir_inode_operations = {
2618
	.lookup		= proc_attr_dir_lookup,
2619
	.getattr	= pid_getattr,
2620
	.setattr	= proc_setattr,
L
Linus Torvalds 已提交
2621 2622
};

2623 2624
#endif

C
Christoph Hellwig 已提交
2625
#ifdef CONFIG_ELF_CORE
2626 2627 2628
static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
					 size_t count, loff_t *ppos)
{
A
Al Viro 已提交
2629
	struct task_struct *task = get_proc_task(file_inode(file));
2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664
	struct mm_struct *mm;
	char buffer[PROC_NUMBUF];
	size_t len;
	int ret;

	if (!task)
		return -ESRCH;

	ret = 0;
	mm = get_task_mm(task);
	if (mm) {
		len = snprintf(buffer, sizeof(buffer), "%08lx\n",
			       ((mm->flags & MMF_DUMP_FILTER_MASK) >>
				MMF_DUMP_FILTER_SHIFT));
		mmput(mm);
		ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
	}

	put_task_struct(task);

	return ret;
}

static ssize_t proc_coredump_filter_write(struct file *file,
					  const char __user *buf,
					  size_t count,
					  loff_t *ppos)
{
	struct task_struct *task;
	struct mm_struct *mm;
	unsigned int val;
	int ret;
	int i;
	unsigned long mask;

2665 2666 2667
	ret = kstrtouint_from_user(buf, count, 0, &val);
	if (ret < 0)
		return ret;
2668 2669

	ret = -ESRCH;
A
Al Viro 已提交
2670
	task = get_proc_task(file_inode(file));
2671 2672 2673 2674 2675 2676
	if (!task)
		goto out_no_task;

	mm = get_task_mm(task);
	if (!mm)
		goto out_no_mm;
2677
	ret = 0;
2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689

	for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
		if (val & mask)
			set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
		else
			clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
	}

	mmput(mm);
 out_no_mm:
	put_task_struct(task);
 out_no_task:
2690 2691 2692
	if (ret < 0)
		return ret;
	return count;
2693 2694 2695 2696 2697
}

static const struct file_operations proc_coredump_filter_operations = {
	.read		= proc_coredump_filter_read,
	.write		= proc_coredump_filter_write,
2698
	.llseek		= generic_file_llseek,
2699 2700 2701
};
#endif

2702
#ifdef CONFIG_TASK_IO_ACCOUNTING
2703
static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2704
{
2705
	struct task_io_accounting acct = task->ioac;
2706
	unsigned long flags;
2707
	int result;
2708

2709 2710 2711 2712
	result = mutex_lock_killable(&task->signal->cred_guard_mutex);
	if (result)
		return result;

2713
	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2714 2715 2716
		result = -EACCES;
		goto out_unlock;
	}
2717

2718 2719 2720 2721 2722 2723 2724 2725
	if (whole && lock_task_sighand(task, &flags)) {
		struct task_struct *t = task;

		task_io_accounting_add(&acct, &task->signal->ioac);
		while_each_thread(task, t)
			task_io_accounting_add(&acct, &t->ioac);

		unlock_task_sighand(task, &flags);
2726
	}
2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743
	seq_printf(m,
		   "rchar: %llu\n"
		   "wchar: %llu\n"
		   "syscr: %llu\n"
		   "syscw: %llu\n"
		   "read_bytes: %llu\n"
		   "write_bytes: %llu\n"
		   "cancelled_write_bytes: %llu\n",
		   (unsigned long long)acct.rchar,
		   (unsigned long long)acct.wchar,
		   (unsigned long long)acct.syscr,
		   (unsigned long long)acct.syscw,
		   (unsigned long long)acct.read_bytes,
		   (unsigned long long)acct.write_bytes,
		   (unsigned long long)acct.cancelled_write_bytes);
	result = 0;

2744 2745 2746
out_unlock:
	mutex_unlock(&task->signal->cred_guard_mutex);
	return result;
2747 2748
}

2749 2750
static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
				  struct pid *pid, struct task_struct *task)
2751
{
2752
	return do_io_accounting(task, m, 0);
2753
}
2754

2755 2756
static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
				   struct pid *pid, struct task_struct *task)
2757
{
2758
	return do_io_accounting(task, m, 1);
2759 2760
}
#endif /* CONFIG_TASK_IO_ACCOUNTING */
2761

2762 2763
#ifdef CONFIG_USER_NS
static int proc_id_map_open(struct inode *inode, struct file *file,
F
Fabian Frederick 已提交
2764
	const struct seq_operations *seq_ops)
2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812
{
	struct user_namespace *ns = NULL;
	struct task_struct *task;
	struct seq_file *seq;
	int ret = -EINVAL;

	task = get_proc_task(inode);
	if (task) {
		rcu_read_lock();
		ns = get_user_ns(task_cred_xxx(task, user_ns));
		rcu_read_unlock();
		put_task_struct(task);
	}
	if (!ns)
		goto err;

	ret = seq_open(file, seq_ops);
	if (ret)
		goto err_put_ns;

	seq = file->private_data;
	seq->private = ns;

	return 0;
err_put_ns:
	put_user_ns(ns);
err:
	return ret;
}

static int proc_id_map_release(struct inode *inode, struct file *file)
{
	struct seq_file *seq = file->private_data;
	struct user_namespace *ns = seq->private;
	put_user_ns(ns);
	return seq_release(inode, file);
}

static int proc_uid_map_open(struct inode *inode, struct file *file)
{
	return proc_id_map_open(inode, file, &proc_uid_seq_operations);
}

static int proc_gid_map_open(struct inode *inode, struct file *file)
{
	return proc_id_map_open(inode, file, &proc_gid_seq_operations);
}

2813 2814 2815 2816 2817
static int proc_projid_map_open(struct inode *inode, struct file *file)
{
	return proc_id_map_open(inode, file, &proc_projid_seq_operations);
}

2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832
static const struct file_operations proc_uid_map_operations = {
	.open		= proc_uid_map_open,
	.write		= proc_uid_map_write,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= proc_id_map_release,
};

static const struct file_operations proc_gid_map_operations = {
	.open		= proc_gid_map_open,
	.write		= proc_gid_map_write,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= proc_id_map_release,
};
2833 2834 2835 2836 2837 2838 2839 2840

static const struct file_operations proc_projid_map_operations = {
	.open		= proc_projid_map_open,
	.write		= proc_projid_map_write,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= proc_id_map_release,
};
2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891

static int proc_setgroups_open(struct inode *inode, struct file *file)
{
	struct user_namespace *ns = NULL;
	struct task_struct *task;
	int ret;

	ret = -ESRCH;
	task = get_proc_task(inode);
	if (task) {
		rcu_read_lock();
		ns = get_user_ns(task_cred_xxx(task, user_ns));
		rcu_read_unlock();
		put_task_struct(task);
	}
	if (!ns)
		goto err;

	if (file->f_mode & FMODE_WRITE) {
		ret = -EACCES;
		if (!ns_capable(ns, CAP_SYS_ADMIN))
			goto err_put_ns;
	}

	ret = single_open(file, &proc_setgroups_show, ns);
	if (ret)
		goto err_put_ns;

	return 0;
err_put_ns:
	put_user_ns(ns);
err:
	return ret;
}

static int proc_setgroups_release(struct inode *inode, struct file *file)
{
	struct seq_file *seq = file->private_data;
	struct user_namespace *ns = seq->private;
	int ret = single_release(inode, file);
	put_user_ns(ns);
	return ret;
}

static const struct file_operations proc_setgroups_operations = {
	.open		= proc_setgroups_open,
	.write		= proc_setgroups_write,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= proc_setgroups_release,
};
2892 2893
#endif /* CONFIG_USER_NS */

2894 2895 2896
static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
				struct pid *pid, struct task_struct *task)
{
2897 2898 2899 2900 2901 2902
	int err = lock_trace(task);
	if (!err) {
		seq_printf(m, "%08x\n", task->personality);
		unlock_trace(task);
	}
	return err;
2903 2904
}

2905 2906 2907 2908 2909 2910 2911 2912 2913
#ifdef CONFIG_LIVEPATCH
static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
				struct pid *pid, struct task_struct *task)
{
	seq_printf(m, "%d\n", task->patch_state);
	return 0;
}
#endif /* CONFIG_LIVEPATCH */

2914 2915 2916
/*
 * Thread groups
 */
2917
static const struct file_operations proc_task_operations;
2918
static const struct inode_operations proc_task_inode_operations;
2919

2920
static const struct pid_entry tgid_base_stuff[] = {
A
Alexey Dobriyan 已提交
2921 2922
	DIR("task",       S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
	DIR("fd",         S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2923
	DIR("map_files",  S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
A
Alexey Dobriyan 已提交
2924
	DIR("fdinfo",     S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2925
	DIR("ns",	  S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
A
Andrew Morton 已提交
2926
#ifdef CONFIG_NET
A
Alexey Dobriyan 已提交
2927
	DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
A
Andrew Morton 已提交
2928
#endif
A
Alexey Dobriyan 已提交
2929
	REG("environ",    S_IRUSR, proc_environ_operations),
A
Al Viro 已提交
2930
	REG("auxv",       S_IRUSR, proc_auxv_operations),
A
Alexey Dobriyan 已提交
2931
	ONE("status",     S_IRUGO, proc_pid_status),
2932
	ONE("personality", S_IRUSR, proc_pid_personality),
2933
	ONE("limits",	  S_IRUGO, proc_pid_limits),
I
Ingo Molnar 已提交
2934
#ifdef CONFIG_SCHED_DEBUG
A
Alexey Dobriyan 已提交
2935
	REG("sched",      S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2936 2937 2938
#endif
#ifdef CONFIG_SCHED_AUTOGROUP
	REG("autogroup",  S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
R
Roland McGrath 已提交
2939
#endif
2940
	REG("comm",      S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
R
Roland McGrath 已提交
2941
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2942
	ONE("syscall",    S_IRUSR, proc_pid_syscall),
I
Ingo Molnar 已提交
2943
#endif
2944
	REG("cmdline",    S_IRUGO, proc_pid_cmdline_ops),
A
Alexey Dobriyan 已提交
2945 2946
	ONE("stat",       S_IRUGO, proc_tgid_stat),
	ONE("statm",      S_IRUGO, proc_pid_statm),
2947
	REG("maps",       S_IRUGO, proc_pid_maps_operations),
2948
#ifdef CONFIG_NUMA
2949
	REG("numa_maps",  S_IRUGO, proc_pid_numa_maps_operations),
2950
#endif
A
Alexey Dobriyan 已提交
2951 2952 2953 2954 2955 2956 2957
	REG("mem",        S_IRUSR|S_IWUSR, proc_mem_operations),
	LNK("cwd",        proc_cwd_link),
	LNK("root",       proc_root_link),
	LNK("exe",        proc_exe_link),
	REG("mounts",     S_IRUGO, proc_mounts_operations),
	REG("mountinfo",  S_IRUGO, proc_mountinfo_operations),
	REG("mountstats", S_IRUSR, proc_mountstats_operations),
2958
#ifdef CONFIG_PROC_PAGE_MONITOR
A
Alexey Dobriyan 已提交
2959
	REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2960
	REG("smaps",      S_IRUGO, proc_pid_smaps_operations),
2961
	REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
2962
	REG("pagemap",    S_IRUSR, proc_pagemap_operations),
2963 2964
#endif
#ifdef CONFIG_SECURITY
A
Alexey Dobriyan 已提交
2965
	DIR("attr",       S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2966 2967
#endif
#ifdef CONFIG_KALLSYMS
2968
	ONE("wchan",      S_IRUGO, proc_pid_wchan),
2969
#endif
K
Ken Chen 已提交
2970
#ifdef CONFIG_STACKTRACE
2971
	ONE("stack",      S_IRUSR, proc_pid_stack),
2972
#endif
2973
#ifdef CONFIG_SCHED_INFO
2974
	ONE("schedstat",  S_IRUGO, proc_pid_schedstat),
2975
#endif
A
Arjan van de Ven 已提交
2976
#ifdef CONFIG_LATENCYTOP
A
Alexey Dobriyan 已提交
2977
	REG("latency",  S_IRUGO, proc_lstats_operations),
A
Arjan van de Ven 已提交
2978
#endif
2979
#ifdef CONFIG_PROC_PID_CPUSET
Z
Zefan Li 已提交
2980
	ONE("cpuset",     S_IRUGO, proc_cpuset_show),
2981 2982
#endif
#ifdef CONFIG_CGROUPS
Z
Zefan Li 已提交
2983
	ONE("cgroup",  S_IRUGO, proc_cgroup_show),
2984
#endif
2985
	ONE("oom_score",  S_IRUGO, proc_oom_score),
2986
	REG("oom_adj",    S_IRUGO|S_IWUSR, proc_oom_adj_operations),
D
David Rientjes 已提交
2987
	REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2988
#ifdef CONFIG_AUDITSYSCALL
A
Alexey Dobriyan 已提交
2989 2990
	REG("loginuid",   S_IWUSR|S_IRUGO, proc_loginuid_operations),
	REG("sessionid",  S_IRUGO, proc_sessionid_operations),
2991
#endif
2992
#ifdef CONFIG_FAULT_INJECTION
A
Alexey Dobriyan 已提交
2993
	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2994
	REG("fail-nth", 0644, proc_fail_nth_operations),
2995
#endif
C
Christoph Hellwig 已提交
2996
#ifdef CONFIG_ELF_CORE
A
Alexey Dobriyan 已提交
2997
	REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2998
#endif
2999
#ifdef CONFIG_TASK_IO_ACCOUNTING
3000
	ONE("io",	S_IRUSR, proc_tgid_io_accounting),
3001
#endif
3002 3003 3004
#ifdef CONFIG_USER_NS
	REG("uid_map",    S_IRUGO|S_IWUSR, proc_uid_map_operations),
	REG("gid_map",    S_IRUGO|S_IWUSR, proc_gid_map_operations),
3005
	REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3006
	REG("setgroups",  S_IRUGO|S_IWUSR, proc_setgroups_operations),
3007
#endif
3008
#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3009 3010
	REG("timers",	  S_IRUGO, proc_timers_operations),
#endif
3011
	REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3012 3013 3014
#ifdef CONFIG_LIVEPATCH
	ONE("patch_state",  S_IRUSR, proc_pid_patch_state),
#endif
3015
};
L
Linus Torvalds 已提交
3016

A
Al Viro 已提交
3017
static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
L
Linus Torvalds 已提交
3018
{
A
Al Viro 已提交
3019 3020
	return proc_pident_readdir(file, ctx,
				   tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
L
Linus Torvalds 已提交
3021 3022
}

3023
static const struct file_operations proc_tgid_base_operations = {
L
Linus Torvalds 已提交
3024
	.read		= generic_read_dir,
3025 3026
	.iterate_shared	= proc_tgid_base_readdir,
	.llseek		= generic_file_llseek,
L
Linus Torvalds 已提交
3027 3028
};

A
Al Viro 已提交
3029 3030
static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
3031 3032
	return proc_pident_lookup(dir, dentry,
				  tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
L
Linus Torvalds 已提交
3033 3034
}

3035
static const struct inode_operations proc_tgid_base_inode_operations = {
3036
	.lookup		= proc_tgid_base_lookup,
3037
	.getattr	= pid_getattr,
3038
	.setattr	= proc_setattr,
3039
	.permission	= proc_pid_permission,
L
Linus Torvalds 已提交
3040 3041
};

3042
static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
L
Linus Torvalds 已提交
3043
{
3044
	struct dentry *dentry, *leader, *dir;
3045
	char buf[10 + 1];
3046 3047 3048
	struct qstr name;

	name.name = buf;
3049
	name.len = snprintf(buf, sizeof(buf), "%u", pid);
3050
	/* no ->d_hash() rejects on procfs */
3051
	dentry = d_hash_and_lookup(mnt->mnt_root, &name);
3052
	if (dentry) {
3053
		d_invalidate(dentry);
3054 3055
		dput(dentry);
	}
L
Linus Torvalds 已提交
3056

3057 3058 3059
	if (pid == tgid)
		return;

3060
	name.name = buf;
3061
	name.len = snprintf(buf, sizeof(buf), "%u", tgid);
3062
	leader = d_hash_and_lookup(mnt->mnt_root, &name);
3063 3064
	if (!leader)
		goto out;
L
Linus Torvalds 已提交
3065

3066 3067 3068 3069 3070 3071 3072
	name.name = "task";
	name.len = strlen(name.name);
	dir = d_hash_and_lookup(leader, &name);
	if (!dir)
		goto out_put_leader;

	name.name = buf;
3073
	name.len = snprintf(buf, sizeof(buf), "%u", pid);
3074 3075
	dentry = d_hash_and_lookup(dir, &name);
	if (dentry) {
3076
		d_invalidate(dentry);
3077
		dput(dentry);
L
Linus Torvalds 已提交
3078
	}
3079 3080 3081 3082 3083 3084

	dput(dir);
out_put_leader:
	dput(leader);
out:
	return;
L
Linus Torvalds 已提交
3085 3086
}

3087 3088 3089 3090 3091
/**
 * proc_flush_task -  Remove dcache entries for @task from the /proc dcache.
 * @task: task that should be flushed.
 *
 * When flushing dentries from proc, one needs to flush them from global
3092
 * proc (proc_mnt) and from all the namespaces' procs this task was seen
3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109
 * in. This call is supposed to do all of this job.
 *
 * Looks in the dcache for
 * /proc/@pid
 * /proc/@tgid/task/@pid
 * if either directory is present flushes it and all of it'ts children
 * from the dcache.
 *
 * It is safe and reasonable to cache /proc entries for a task until
 * that task exits.  After that they just clog up the dcache with
 * useless entries, possibly causing useful dcache entries to be
 * flushed instead.  This routine is proved to flush those useless
 * dcache entries at process exit time.
 *
 * NOTE: This routine is just an optimization so it does not guarantee
 *       that no dcache entries will exist at process exit time it
 *       just makes it very unlikely that any will persist.
3110 3111 3112 3113
 */

void proc_flush_task(struct task_struct *task)
{
3114
	int i;
3115
	struct pid *pid, *tgid;
3116 3117 3118
	struct upid *upid;

	pid = task_pid(task);
3119
	tgid = task_tgid(task);
3120

3121
	for (i = 0; i <= pid->level; i++) {
3122 3123
		upid = &pid->numbers[i];
		proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3124
					tgid->numbers[i].nr);
3125
	}
3126 3127
}

3128 3129 3130
static int proc_pid_instantiate(struct inode *dir,
				   struct dentry * dentry,
				   struct task_struct *task, const void *ptr)
3131 3132 3133
{
	struct inode *inode;

3134
	inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3135 3136 3137 3138 3139 3140
	if (!inode)
		goto out;

	inode->i_op = &proc_tgid_base_inode_operations;
	inode->i_fop = &proc_tgid_base_operations;
	inode->i_flags|=S_IMMUTABLE;
3141

3142
	set_nlink(inode, nlink_tgid);
3143

3144
	d_set_d_op(dentry, &pid_dentry_operations);
3145 3146 3147

	d_add(dentry, inode);
	/* Close the race of the process dying before we return the dentry */
3148
	if (pid_revalidate(dentry, 0))
3149
		return 0;
3150
out:
3151
	return -ENOENT;
3152 3153
}

A
Al Viro 已提交
3154
struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
L
Linus Torvalds 已提交
3155
{
A
Alexey Dobriyan 已提交
3156
	int result = -ENOENT;
L
Linus Torvalds 已提交
3157 3158
	struct task_struct *task;
	unsigned tgid;
3159
	struct pid_namespace *ns;
L
Linus Torvalds 已提交
3160

3161
	tgid = name_to_int(&dentry->d_name);
L
Linus Torvalds 已提交
3162 3163 3164
	if (tgid == ~0U)
		goto out;

3165
	ns = dentry->d_sb->s_fs_info;
3166
	rcu_read_lock();
3167
	task = find_task_by_pid_ns(tgid, ns);
L
Linus Torvalds 已提交
3168 3169
	if (task)
		get_task_struct(task);
3170
	rcu_read_unlock();
L
Linus Torvalds 已提交
3171 3172 3173
	if (!task)
		goto out;

3174
	result = proc_pid_instantiate(dir, dentry, task, NULL);
L
Linus Torvalds 已提交
3175 3176
	put_task_struct(task);
out:
3177
	return ERR_PTR(result);
L
Linus Torvalds 已提交
3178 3179 3180
}

/*
3181
 * Find the first task with tgid >= tgid
3182
 *
L
Linus Torvalds 已提交
3183
 */
3184 3185
struct tgid_iter {
	unsigned int tgid;
3186
	struct task_struct *task;
3187 3188 3189
};
static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
{
3190
	struct pid *pid;
L
Linus Torvalds 已提交
3191

3192 3193
	if (iter.task)
		put_task_struct(iter.task);
3194
	rcu_read_lock();
3195
retry:
3196 3197
	iter.task = NULL;
	pid = find_ge_pid(iter.tgid, ns);
3198
	if (pid) {
3199 3200
		iter.tgid = pid_nr_ns(pid, ns);
		iter.task = pid_task(pid, PIDTYPE_PID);
3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212
		/* What we to know is if the pid we have find is the
		 * pid of a thread_group_leader.  Testing for task
		 * being a thread_group_leader is the obvious thing
		 * todo but there is a window when it fails, due to
		 * the pid transfer logic in de_thread.
		 *
		 * So we perform the straight forward test of seeing
		 * if the pid we have found is the pid of a thread
		 * group leader, and don't worry if the task we have
		 * found doesn't happen to be a thread group leader.
		 * As we don't care in the case of readdir.
		 */
3213 3214
		if (!iter.task || !has_group_leader_pid(iter.task)) {
			iter.tgid += 1;
3215
			goto retry;
3216 3217
		}
		get_task_struct(iter.task);
3218
	}
3219
	rcu_read_unlock();
3220
	return iter;
L
Linus Torvalds 已提交
3221 3222
}

3223
#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3224

L
Linus Torvalds 已提交
3225
/* for the /proc/ directory itself, after non-process stuff has been done */
A
Al Viro 已提交
3226
int proc_pid_readdir(struct file *file, struct dir_context *ctx)
L
Linus Torvalds 已提交
3227
{
3228
	struct tgid_iter iter;
A
Al Viro 已提交
3229
	struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info;
A
Al Viro 已提交
3230
	loff_t pos = ctx->pos;
L
Linus Torvalds 已提交
3231

3232
	if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
A
Al Viro 已提交
3233
		return 0;
L
Linus Torvalds 已提交
3234

3235
	if (pos == TGID_OFFSET - 2) {
3236
		struct inode *inode = d_inode(ns->proc_self);
3237
		if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
A
Al Viro 已提交
3238
			return 0;
3239 3240 3241
		ctx->pos = pos = pos + 1;
	}
	if (pos == TGID_OFFSET - 1) {
3242
		struct inode *inode = d_inode(ns->proc_thread_self);
3243 3244 3245
		if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
			return 0;
		ctx->pos = pos = pos + 1;
3246
	}
3247
	iter.tgid = pos - TGID_OFFSET;
3248 3249 3250 3251
	iter.task = NULL;
	for (iter = next_tgid(ns, iter);
	     iter.task;
	     iter.tgid += 1, iter = next_tgid(ns, iter)) {
3252
		char name[10 + 1];
A
Al Viro 已提交
3253
		int len;
3254 3255

		cond_resched();
3256
		if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE))
A
Al Viro 已提交
3257
			continue;
3258

3259
		len = snprintf(name, sizeof(name), "%u", iter.tgid);
A
Al Viro 已提交
3260 3261 3262
		ctx->pos = iter.tgid + TGID_OFFSET;
		if (!proc_fill_cache(file, ctx, name, len,
				     proc_pid_instantiate, iter.task, NULL)) {
3263
			put_task_struct(iter.task);
A
Al Viro 已提交
3264
			return 0;
L
Linus Torvalds 已提交
3265
		}
3266
	}
A
Al Viro 已提交
3267
	ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3268 3269
	return 0;
}
L
Linus Torvalds 已提交
3270

3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308
/*
 * proc_tid_comm_permission is a special permission function exclusively
 * used for the node /proc/<pid>/task/<tid>/comm.
 * It bypasses generic permission checks in the case where a task of the same
 * task group attempts to access the node.
 * The rationale behind this is that glibc and bionic access this node for
 * cross thread naming (pthread_set/getname_np(!self)). However, if
 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
 * which locks out the cross thread naming implementation.
 * This function makes sure that the node is always accessible for members of
 * same thread group.
 */
static int proc_tid_comm_permission(struct inode *inode, int mask)
{
	bool is_same_tgroup;
	struct task_struct *task;

	task = get_proc_task(inode);
	if (!task)
		return -ESRCH;
	is_same_tgroup = same_thread_group(current, task);
	put_task_struct(task);

	if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
		/* This file (/proc/<pid>/task/<tid>/comm) can always be
		 * read or written by the members of the corresponding
		 * thread group.
		 */
		return 0;
	}

	return generic_permission(inode, mask);
}

static const struct inode_operations proc_tid_comm_inode_operations = {
		.permission = proc_tid_comm_permission,
};

3309 3310 3311
/*
 * Tasks
 */
3312
static const struct pid_entry tid_base_stuff[] = {
A
Alexey Dobriyan 已提交
3313
	DIR("fd",        S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
J
Jerome Marchand 已提交
3314
	DIR("fdinfo",    S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3315
	DIR("ns",	 S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3316 3317 3318
#ifdef CONFIG_NET
	DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
#endif
A
Alexey Dobriyan 已提交
3319
	REG("environ",   S_IRUSR, proc_environ_operations),
A
Al Viro 已提交
3320
	REG("auxv",      S_IRUSR, proc_auxv_operations),
A
Alexey Dobriyan 已提交
3321
	ONE("status",    S_IRUGO, proc_pid_status),
3322
	ONE("personality", S_IRUSR, proc_pid_personality),
3323
	ONE("limits",	 S_IRUGO, proc_pid_limits),
I
Ingo Molnar 已提交
3324
#ifdef CONFIG_SCHED_DEBUG
A
Alexey Dobriyan 已提交
3325
	REG("sched",     S_IRUGO|S_IWUSR, proc_pid_sched_operations),
R
Roland McGrath 已提交
3326
#endif
3327 3328 3329
	NOD("comm",      S_IFREG|S_IRUGO|S_IWUSR,
			 &proc_tid_comm_inode_operations,
			 &proc_pid_set_comm_operations, {}),
R
Roland McGrath 已提交
3330
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3331
	ONE("syscall",   S_IRUSR, proc_pid_syscall),
I
Ingo Molnar 已提交
3332
#endif
3333
	REG("cmdline",   S_IRUGO, proc_pid_cmdline_ops),
A
Alexey Dobriyan 已提交
3334 3335
	ONE("stat",      S_IRUGO, proc_tid_stat),
	ONE("statm",     S_IRUGO, proc_pid_statm),
3336
	REG("maps",      S_IRUGO, proc_tid_maps_operations),
3337
#ifdef CONFIG_PROC_CHILDREN
3338 3339
	REG("children",  S_IRUGO, proc_tid_children_operations),
#endif
3340
#ifdef CONFIG_NUMA
3341
	REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3342
#endif
A
Alexey Dobriyan 已提交
3343 3344 3345 3346 3347 3348
	REG("mem",       S_IRUSR|S_IWUSR, proc_mem_operations),
	LNK("cwd",       proc_cwd_link),
	LNK("root",      proc_root_link),
	LNK("exe",       proc_exe_link),
	REG("mounts",    S_IRUGO, proc_mounts_operations),
	REG("mountinfo",  S_IRUGO, proc_mountinfo_operations),
3349
#ifdef CONFIG_PROC_PAGE_MONITOR
A
Alexey Dobriyan 已提交
3350
	REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3351
	REG("smaps",     S_IRUGO, proc_tid_smaps_operations),
3352
	REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3353
	REG("pagemap",    S_IRUSR, proc_pagemap_operations),
3354 3355
#endif
#ifdef CONFIG_SECURITY
A
Alexey Dobriyan 已提交
3356
	DIR("attr",      S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3357 3358
#endif
#ifdef CONFIG_KALLSYMS
3359
	ONE("wchan",     S_IRUGO, proc_pid_wchan),
3360
#endif
K
Ken Chen 已提交
3361
#ifdef CONFIG_STACKTRACE
3362
	ONE("stack",      S_IRUSR, proc_pid_stack),
3363
#endif
3364
#ifdef CONFIG_SCHED_INFO
3365
	ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3366
#endif
A
Arjan van de Ven 已提交
3367
#ifdef CONFIG_LATENCYTOP
A
Alexey Dobriyan 已提交
3368
	REG("latency",  S_IRUGO, proc_lstats_operations),
A
Arjan van de Ven 已提交
3369
#endif
3370
#ifdef CONFIG_PROC_PID_CPUSET
Z
Zefan Li 已提交
3371
	ONE("cpuset",    S_IRUGO, proc_cpuset_show),
3372 3373
#endif
#ifdef CONFIG_CGROUPS
Z
Zefan Li 已提交
3374
	ONE("cgroup",  S_IRUGO, proc_cgroup_show),
3375
#endif
3376
	ONE("oom_score", S_IRUGO, proc_oom_score),
3377
	REG("oom_adj",   S_IRUGO|S_IWUSR, proc_oom_adj_operations),
D
David Rientjes 已提交
3378
	REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3379
#ifdef CONFIG_AUDITSYSCALL
A
Alexey Dobriyan 已提交
3380
	REG("loginuid",  S_IWUSR|S_IRUGO, proc_loginuid_operations),
3381
	REG("sessionid",  S_IRUGO, proc_sessionid_operations),
3382
#endif
3383
#ifdef CONFIG_FAULT_INJECTION
A
Alexey Dobriyan 已提交
3384
	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3385
	REG("fail-nth", 0644, proc_fail_nth_operations),
3386
#endif
3387
#ifdef CONFIG_TASK_IO_ACCOUNTING
3388
	ONE("io",	S_IRUSR, proc_tid_io_accounting),
3389
#endif
3390 3391 3392
#ifdef CONFIG_USER_NS
	REG("uid_map",    S_IRUGO|S_IWUSR, proc_uid_map_operations),
	REG("gid_map",    S_IRUGO|S_IWUSR, proc_gid_map_operations),
3393
	REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3394
	REG("setgroups",  S_IRUGO|S_IWUSR, proc_setgroups_operations),
3395
#endif
3396 3397 3398
#ifdef CONFIG_LIVEPATCH
	ONE("patch_state",  S_IRUSR, proc_pid_patch_state),
#endif
3399 3400
};

A
Al Viro 已提交
3401
static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3402
{
A
Al Viro 已提交
3403 3404
	return proc_pident_readdir(file, ctx,
				   tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3405 3406
}

A
Al Viro 已提交
3407 3408
static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
3409 3410
	return proc_pident_lookup(dir, dentry,
				  tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3411 3412
}

3413
static const struct file_operations proc_tid_base_operations = {
3414
	.read		= generic_read_dir,
3415 3416
	.iterate_shared	= proc_tid_base_readdir,
	.llseek		= generic_file_llseek,
3417 3418
};

3419
static const struct inode_operations proc_tid_base_inode_operations = {
3420 3421 3422 3423 3424
	.lookup		= proc_tid_base_lookup,
	.getattr	= pid_getattr,
	.setattr	= proc_setattr,
};

3425
static int proc_task_instantiate(struct inode *dir,
3426
	struct dentry *dentry, struct task_struct *task, const void *ptr)
3427 3428
{
	struct inode *inode;
3429
	inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3430 3431 3432 3433 3434 3435

	if (!inode)
		goto out;
	inode->i_op = &proc_tid_base_inode_operations;
	inode->i_fop = &proc_tid_base_operations;
	inode->i_flags|=S_IMMUTABLE;
3436

3437
	set_nlink(inode, nlink_tid);
3438

3439
	d_set_d_op(dentry, &pid_dentry_operations);
3440 3441 3442

	d_add(dentry, inode);
	/* Close the race of the process dying before we return the dentry */
3443
	if (pid_revalidate(dentry, 0))
3444
		return 0;
3445
out:
3446
	return -ENOENT;
3447 3448
}

A
Al Viro 已提交
3449
static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3450
{
3451
	int result = -ENOENT;
3452 3453 3454
	struct task_struct *task;
	struct task_struct *leader = get_proc_task(dir);
	unsigned tid;
3455
	struct pid_namespace *ns;
3456 3457 3458 3459

	if (!leader)
		goto out_no_task;

3460
	tid = name_to_int(&dentry->d_name);
3461 3462 3463
	if (tid == ~0U)
		goto out;

3464
	ns = dentry->d_sb->s_fs_info;
3465
	rcu_read_lock();
3466
	task = find_task_by_pid_ns(tid, ns);
3467 3468 3469 3470 3471
	if (task)
		get_task_struct(task);
	rcu_read_unlock();
	if (!task)
		goto out;
3472
	if (!same_thread_group(leader, task))
3473 3474
		goto out_drop_task;

3475
	result = proc_task_instantiate(dir, dentry, task, NULL);
3476 3477 3478 3479 3480
out_drop_task:
	put_task_struct(task);
out:
	put_task_struct(leader);
out_no_task:
3481
	return ERR_PTR(result);
3482 3483
}

3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495
/*
 * Find the first tid of a thread group to return to user space.
 *
 * Usually this is just the thread group leader, but if the users
 * buffer was too small or there was a seek into the middle of the
 * directory we have more work todo.
 *
 * In the case of a short read we start with find_task_by_pid.
 *
 * In the case of a seek we start with the leader and walk nr
 * threads past it.
 */
3496 3497
static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
					struct pid_namespace *ns)
3498
{
3499
	struct task_struct *pos, *task;
3500 3501 3502 3503
	unsigned long nr = f_pos;

	if (nr != f_pos)	/* 32bit overflow? */
		return NULL;
L
Linus Torvalds 已提交
3504

3505
	rcu_read_lock();
3506 3507 3508 3509 3510
	task = pid_task(pid, PIDTYPE_PID);
	if (!task)
		goto fail;

	/* Attempt to start with the tid of a thread */
3511
	if (tid && nr) {
3512
		pos = find_task_by_pid_ns(tid, ns);
3513
		if (pos && same_thread_group(pos, task))
O
Oleg Nesterov 已提交
3514
			goto found;
3515
	}
L
Linus Torvalds 已提交
3516

3517
	/* If nr exceeds the number of threads there is nothing todo */
3518
	if (nr >= get_nr_threads(task))
3519
		goto fail;
L
Linus Torvalds 已提交
3520

O
Oleg Nesterov 已提交
3521 3522
	/* If we haven't found our starting place yet start
	 * with the leader and walk nr threads forward.
3523
	 */
3524
	pos = task = task->group_leader;
3525
	do {
3526
		if (!nr--)
3527
			goto found;
3528
	} while_each_thread(task, pos);
3529 3530 3531
fail:
	pos = NULL;
	goto out;
O
Oleg Nesterov 已提交
3532 3533 3534
found:
	get_task_struct(pos);
out:
3535
	rcu_read_unlock();
3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546
	return pos;
}

/*
 * Find the next thread in the thread list.
 * Return NULL if there is an error or no next thread.
 *
 * The reference to the input task_struct is released.
 */
static struct task_struct *next_tid(struct task_struct *start)
{
O
Oleg Nesterov 已提交
3547
	struct task_struct *pos = NULL;
3548
	rcu_read_lock();
O
Oleg Nesterov 已提交
3549
	if (pid_alive(start)) {
3550
		pos = next_thread(start);
O
Oleg Nesterov 已提交
3551 3552 3553 3554 3555
		if (thread_group_leader(pos))
			pos = NULL;
		else
			get_task_struct(pos);
	}
3556
	rcu_read_unlock();
3557 3558
	put_task_struct(start);
	return pos;
L
Linus Torvalds 已提交
3559 3560 3561
}

/* for the /proc/TGID/task/ directories */
A
Al Viro 已提交
3562
static int proc_task_readdir(struct file *file, struct dir_context *ctx)
L
Linus Torvalds 已提交
3563
{
3564 3565
	struct inode *inode = file_inode(file);
	struct task_struct *task;
3566
	struct pid_namespace *ns;
A
Al Viro 已提交
3567
	int tid;
L
Linus Torvalds 已提交
3568

3569
	if (proc_inode_is_dead(inode))
A
Al Viro 已提交
3570
		return -ENOENT;
L
Linus Torvalds 已提交
3571

A
Al Viro 已提交
3572
	if (!dir_emit_dots(file, ctx))
3573
		return 0;
L
Linus Torvalds 已提交
3574

3575 3576 3577
	/* f_version caches the tgid value that the last readdir call couldn't
	 * return. lseek aka telldir automagically resets f_version to 0.
	 */
A
Al Viro 已提交
3578
	ns = inode->i_sb->s_fs_info;
A
Al Viro 已提交
3579 3580
	tid = (int)file->f_version;
	file->f_version = 0;
3581
	for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3582
	     task;
A
Al Viro 已提交
3583
	     task = next_tid(task), ctx->pos++) {
3584
		char name[10 + 1];
A
Al Viro 已提交
3585
		int len;
3586
		tid = task_pid_nr_ns(task, ns);
3587
		len = snprintf(name, sizeof(name), "%u", tid);
A
Al Viro 已提交
3588 3589
		if (!proc_fill_cache(file, ctx, name, len,
				proc_task_instantiate, task, NULL)) {
3590 3591
			/* returning this tgid failed, save it as the first
			 * pid for the next readir call */
A
Al Viro 已提交
3592
			file->f_version = (u64)tid;
3593
			put_task_struct(task);
L
Linus Torvalds 已提交
3594
			break;
3595
		}
L
Linus Torvalds 已提交
3596
	}
3597

A
Al Viro 已提交
3598
	return 0;
L
Linus Torvalds 已提交
3599
}
3600

3601 3602
static int proc_task_getattr(const struct path *path, struct kstat *stat,
			     u32 request_mask, unsigned int query_flags)
3603
{
3604
	struct inode *inode = d_inode(path->dentry);
3605
	struct task_struct *p = get_proc_task(inode);
3606 3607
	generic_fillattr(inode, stat);

3608 3609 3610
	if (p) {
		stat->nlink += get_nr_threads(p);
		put_task_struct(p);
3611 3612 3613 3614
	}

	return 0;
}
3615

3616
static const struct inode_operations proc_task_inode_operations = {
3617 3618 3619
	.lookup		= proc_task_lookup,
	.getattr	= proc_task_getattr,
	.setattr	= proc_setattr,
3620
	.permission	= proc_pid_permission,
3621 3622
};

3623
static const struct file_operations proc_task_operations = {
3624
	.read		= generic_read_dir,
3625 3626
	.iterate_shared	= proc_task_readdir,
	.llseek		= generic_file_llseek,
3627
};
3628 3629 3630 3631 3632 3633

void __init set_proc_pid_nlink(void)
{
	nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
	nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
}