base.c revision c2f273eb
1// SPDX-License-Identifier: GPL-2.0
2/*
3 *  linux/fs/proc/base.c
4 *
5 *  Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 *  proc base directory handling functions
8 *
9 *  1999, Al Viro. Rewritten. Now it covers the whole per-process part.
10 *  Instead of using magical inumbers to determine the kind of object
11 *  we allocate and fill in-core inodes upon lookup. They don't even
12 *  go into icache. We cache the reference to task_struct upon lookup too.
13 *  Eventually it should become a filesystem in its own. We don't use the
14 *  rest of procfs anymore.
15 *
16 *
17 *  Changelog:
18 *  17-Jan-2005
19 *  Allan Bezerra
20 *  Bruna Moreira <bruna.moreira@indt.org.br>
21 *  Edjard Mota <edjard.mota@indt.org.br>
22 *  Ilias Biris <ilias.biris@indt.org.br>
23 *  Mauricio Lin <mauricio.lin@indt.org.br>
24 *
25 *  Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
26 *
27 *  A new process specific entry (smaps) included in /proc. It shows the
28 *  size of rss for each memory area. The maps entry lacks information
29 *  about physical memory size (rss) for each mapped file, i.e.,
30 *  rss information for executables and library files.
31 *  This additional information is useful for any tools that need to know
32 *  about physical memory consumption for a process specific library.
33 *
34 *  Changelog:
35 *  21-Feb-2005
36 *  Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
37 *  Pud inclusion in the page table walking.
38 *
39 *  ChangeLog:
40 *  10-Mar-2005
41 *  10LE Instituto Nokia de Tecnologia - INdT:
42 *  A better way to walks through the page table as suggested by Hugh Dickins.
43 *
44 *  Simo Piiroinen <simo.piiroinen@nokia.com>:
45 *  Smaps information related to shared, private, clean and dirty pages.
46 *
47 *  Paul Mundt <paul.mundt@nokia.com>:
48 *  Overall revision about smaps.
49 */
50
51#include <linux/uaccess.h>
52
53#include <linux/errno.h>
54#include <linux/time.h>
55#include <linux/proc_fs.h>
56#include <linux/stat.h>
57#include <linux/task_io_accounting_ops.h>
58#include <linux/init.h>
59#include <linux/capability.h>
60#include <linux/file.h>
61#include <linux/fdtable.h>
62#include <linux/generic-radix-tree.h>
63#include <linux/string.h>
64#include <linux/seq_file.h>
65#include <linux/namei.h>
66#include <linux/mnt_namespace.h>
67#include <linux/mm.h>
68#include <linux/swap.h>
69#include <linux/rcupdate.h>
70#include <linux/stacktrace.h>
71#include <linux/resource.h>
72#include <linux/module.h>
73#include <linux/mount.h>
74#include <linux/security.h>
75#include <linux/ptrace.h>
76#include <linux/tracehook.h>
77#include <linux/printk.h>
78#include <linux/cache.h>
79#include <linux/cgroup.h>
80#include <linux/cpuset.h>
81#include <linux/audit.h>
82#include <linux/poll.h>
83#include <linux/nsproxy.h>
84#include <linux/oom.h>
85#include <linux/elf.h>
86#include <linux/pid_namespace.h>
87#include <linux/user_namespace.h>
88#include <linux/fs_struct.h>
89#include <linux/slab.h>
90#include <linux/sched/autogroup.h>
91#include <linux/sched/mm.h>
92#include <linux/sched/coredump.h>
93#include <linux/sched/debug.h>
94#include <linux/sched/stat.h>
95#include <linux/posix-timers.h>
96#include <linux/time_namespace.h>
97#include <linux/resctrl.h>
98#include <linux/cn_proc.h>
99#include <trace/events/oom.h>
100#include "internal.h"
101#include "fd.h"
102
103#include "../../lib/kstrtox.h"
104
105/* NOTE:
106 *	Implementing inode permission operations in /proc is almost
107 *	certainly an error.  Permission checks need to happen during
108 *	each system call not at open time.  The reason is that most of
109 *	what we wish to check for permissions in /proc varies at runtime.
110 *
111 *	The classic example of a problem is opening file descriptors
112 *	in /proc for a task before it execs a suid executable.
113 */
114
115static u8 nlink_tid __ro_after_init;
116static u8 nlink_tgid __ro_after_init;
117
118struct pid_entry {
119	const char *name;
120	unsigned int len;
121	umode_t mode;
122	const struct inode_operations *iop;
123	const struct file_operations *fop;
124	union proc_op op;
125};
126
127#define NOD(NAME, MODE, IOP, FOP, OP) {			\
128	.name = (NAME),					\
129	.len  = sizeof(NAME) - 1,			\
130	.mode = MODE,					\
131	.iop  = IOP,					\
132	.fop  = FOP,					\
133	.op   = OP,					\
134}
135
136#define DIR(NAME, MODE, iops, fops)	\
137	NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
138#define LNK(NAME, get_link)					\
139	NOD(NAME, (S_IFLNK|S_IRWXUGO),				\
140		&proc_pid_link_inode_operations, NULL,		\
141		{ .proc_get_link = get_link } )
142#define REG(NAME, MODE, fops)				\
143	NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
144#define ONE(NAME, MODE, show)				\
145	NOD(NAME, (S_IFREG|(MODE)),			\
146		NULL, &proc_single_file_operations,	\
147		{ .proc_show = show } )
148#define ATTR(LSM, NAME, MODE)				\
149	NOD(NAME, (S_IFREG|(MODE)),			\
150		NULL, &proc_pid_attr_operations,	\
151		{ .lsm = LSM })
152
153/*
154 * Count the number of hardlinks for the pid_entry table, excluding the .
155 * and .. links.
156 */
157static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
158	unsigned int n)
159{
160	unsigned int i;
161	unsigned int count;
162
163	count = 2;
164	for (i = 0; i < n; ++i) {
165		if (S_ISDIR(entries[i].mode))
166			++count;
167	}
168
169	return count;
170}
171
172static int get_task_root(struct task_struct *task, struct path *root)
173{
174	int result = -ENOENT;
175
176	task_lock(task);
177	if (task->fs) {
178		get_fs_root(task->fs, root);
179		result = 0;
180	}
181	task_unlock(task);
182	return result;
183}
184
185static int proc_cwd_link(struct dentry *dentry, struct path *path)
186{
187	struct task_struct *task = get_proc_task(d_inode(dentry));
188	int result = -ENOENT;
189
190	if (task) {
191		task_lock(task);
192		if (task->fs) {
193			get_fs_pwd(task->fs, path);
194			result = 0;
195		}
196		task_unlock(task);
197		put_task_struct(task);
198	}
199	return result;
200}
201
202static int proc_root_link(struct dentry *dentry, struct path *path)
203{
204	struct task_struct *task = get_proc_task(d_inode(dentry));
205	int result = -ENOENT;
206
207	if (task) {
208		result = get_task_root(task, path);
209		put_task_struct(task);
210	}
211	return result;
212}
213
214/*
215 * If the user used setproctitle(), we just get the string from
216 * user space at arg_start, and limit it to a maximum of one page.
217 */
218static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf,
219				size_t count, unsigned long pos,
220				unsigned long arg_start)
221{
222	char *page;
223	int ret, got;
224
225	if (pos >= PAGE_SIZE)
226		return 0;
227
228	page = (char *)__get_free_page(GFP_KERNEL);
229	if (!page)
230		return -ENOMEM;
231
232	ret = 0;
233	got = access_remote_vm(mm, arg_start, page, PAGE_SIZE, FOLL_ANON);
234	if (got > 0) {
235		int len = strnlen(page, got);
236
237		/* Include the NUL character if it was found */
238		if (len < got)
239			len++;
240
241		if (len > pos) {
242			len -= pos;
243			if (len > count)
244				len = count;
245			len -= copy_to_user(buf, page+pos, len);
246			if (!len)
247				len = -EFAULT;
248			ret = len;
249		}
250	}
251	free_page((unsigned long)page);
252	return ret;
253}
254
255static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
256			      size_t count, loff_t *ppos)
257{
258	unsigned long arg_start, arg_end, env_start, env_end;
259	unsigned long pos, len;
260	char *page, c;
261
262	/* Check if process spawned far enough to have cmdline. */
263	if (!mm->env_end)
264		return 0;
265
266	spin_lock(&mm->arg_lock);
267	arg_start = mm->arg_start;
268	arg_end = mm->arg_end;
269	env_start = mm->env_start;
270	env_end = mm->env_end;
271	spin_unlock(&mm->arg_lock);
272
273	if (arg_start >= arg_end)
274		return 0;
275
276	/*
277	 * We allow setproctitle() to overwrite the argument
278	 * strings, and overflow past the original end. But
279	 * only when it overflows into the environment area.
280	 */
281	if (env_start != arg_end || env_end < env_start)
282		env_start = env_end = arg_end;
283	len = env_end - arg_start;
284
285	/* We're not going to care if "*ppos" has high bits set */
286	pos = *ppos;
287	if (pos >= len)
288		return 0;
289	if (count > len - pos)
290		count = len - pos;
291	if (!count)
292		return 0;
293
294	/*
295	 * Magical special case: if the argv[] end byte is not
296	 * zero, the user has overwritten it with setproctitle(3).
297	 *
298	 * Possible future enhancement: do this only once when
299	 * pos is 0, and set a flag in the 'struct file'.
300	 */
301	if (access_remote_vm(mm, arg_end-1, &c, 1, FOLL_ANON) == 1 && c)
302		return get_mm_proctitle(mm, buf, count, pos, arg_start);
303
304	/*
305	 * For the non-setproctitle() case we limit things strictly
306	 * to the [arg_start, arg_end[ range.
307	 */
308	pos += arg_start;
309	if (pos < arg_start || pos >= arg_end)
310		return 0;
311	if (count > arg_end - pos)
312		count = arg_end - pos;
313
314	page = (char *)__get_free_page(GFP_KERNEL);
315	if (!page)
316		return -ENOMEM;
317
318	len = 0;
319	while (count) {
320		int got;
321		size_t size = min_t(size_t, PAGE_SIZE, count);
322
323		got = access_remote_vm(mm, pos, page, size, FOLL_ANON);
324		if (got <= 0)
325			break;
326		got -= copy_to_user(buf, page, got);
327		if (unlikely(!got)) {
328			if (!len)
329				len = -EFAULT;
330			break;
331		}
332		pos += got;
333		buf += got;
334		len += got;
335		count -= got;
336	}
337
338	free_page((unsigned long)page);
339	return len;
340}
341
342static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf,
343				size_t count, loff_t *pos)
344{
345	struct mm_struct *mm;
346	ssize_t ret;
347
348	mm = get_task_mm(tsk);
349	if (!mm)
350		return 0;
351
352	ret = get_mm_cmdline(mm, buf, count, pos);
353	mmput(mm);
354	return ret;
355}
356
357static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
358				     size_t count, loff_t *pos)
359{
360	struct task_struct *tsk;
361	ssize_t ret;
362
363	BUG_ON(*pos < 0);
364
365	tsk = get_proc_task(file_inode(file));
366	if (!tsk)
367		return -ESRCH;
368	ret = get_task_cmdline(tsk, buf, count, pos);
369	put_task_struct(tsk);
370	if (ret > 0)
371		*pos += ret;
372	return ret;
373}
374
375static const struct file_operations proc_pid_cmdline_ops = {
376	.read	= proc_pid_cmdline_read,
377	.llseek	= generic_file_llseek,
378};
379
380#ifdef CONFIG_KALLSYMS
381/*
382 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
383 * Returns the resolved symbol.  If that fails, simply return the address.
384 */
385static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
386			  struct pid *pid, struct task_struct *task)
387{
388	unsigned long wchan;
389
390	if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
391		wchan = get_wchan(task);
392	else
393		wchan = 0;
394
395	if (wchan)
396		seq_printf(m, "%ps", (void *) wchan);
397	else
398		seq_putc(m, '0');
399
400	return 0;
401}
402#endif /* CONFIG_KALLSYMS */
403
404static int lock_trace(struct task_struct *task)
405{
406	int err = down_read_killable(&task->signal->exec_update_lock);
407	if (err)
408		return err;
409	if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
410		up_read(&task->signal->exec_update_lock);
411		return -EPERM;
412	}
413	return 0;
414}
415
416static void unlock_trace(struct task_struct *task)
417{
418	up_read(&task->signal->exec_update_lock);
419}
420
421#ifdef CONFIG_STACKTRACE
422
423#define MAX_STACK_TRACE_DEPTH	64
424
425static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
426			  struct pid *pid, struct task_struct *task)
427{
428	unsigned long *entries;
429	int err;
430
431	/*
432	 * The ability to racily run the kernel stack unwinder on a running task
433	 * and then observe the unwinder output is scary; while it is useful for
434	 * debugging kernel issues, it can also allow an attacker to leak kernel
435	 * stack contents.
436	 * Doing this in a manner that is at least safe from races would require
437	 * some work to ensure that the remote task can not be scheduled; and
438	 * even then, this would still expose the unwinder as local attack
439	 * surface.
440	 * Therefore, this interface is restricted to root.
441	 */
442	if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
443		return -EACCES;
444
445	entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
446				GFP_KERNEL);
447	if (!entries)
448		return -ENOMEM;
449
450	err = lock_trace(task);
451	if (!err) {
452		unsigned int i, nr_entries;
453
454		nr_entries = stack_trace_save_tsk(task, entries,
455						  MAX_STACK_TRACE_DEPTH, 0);
456
457		for (i = 0; i < nr_entries; i++) {
458			seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
459		}
460
461		unlock_trace(task);
462	}
463	kfree(entries);
464
465	return err;
466}
467#endif
468
469#ifdef CONFIG_SCHED_INFO
470/*
471 * Provides /proc/PID/schedstat
472 */
473static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
474			      struct pid *pid, struct task_struct *task)
475{
476	if (unlikely(!sched_info_on()))
477		seq_puts(m, "0 0 0\n");
478	else
479		seq_printf(m, "%llu %llu %lu\n",
480		   (unsigned long long)task->se.sum_exec_runtime,
481		   (unsigned long long)task->sched_info.run_delay,
482		   task->sched_info.pcount);
483
484	return 0;
485}
486#endif
487
488#ifdef CONFIG_LATENCYTOP
489static int lstats_show_proc(struct seq_file *m, void *v)
490{
491	int i;
492	struct inode *inode = m->private;
493	struct task_struct *task = get_proc_task(inode);
494
495	if (!task)
496		return -ESRCH;
497	seq_puts(m, "Latency Top version : v0.1\n");
498	for (i = 0; i < LT_SAVECOUNT; i++) {
499		struct latency_record *lr = &task->latency_record[i];
500		if (lr->backtrace[0]) {
501			int q;
502			seq_printf(m, "%i %li %li",
503				   lr->count, lr->time, lr->max);
504			for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
505				unsigned long bt = lr->backtrace[q];
506
507				if (!bt)
508					break;
509				seq_printf(m, " %ps", (void *)bt);
510			}
511			seq_putc(m, '\n');
512		}
513
514	}
515	put_task_struct(task);
516	return 0;
517}
518
519static int lstats_open(struct inode *inode, struct file *file)
520{
521	return single_open(file, lstats_show_proc, inode);
522}
523
524static ssize_t lstats_write(struct file *file, const char __user *buf,
525			    size_t count, loff_t *offs)
526{
527	struct task_struct *task = get_proc_task(file_inode(file));
528
529	if (!task)
530		return -ESRCH;
531	clear_tsk_latency_tracing(task);
532	put_task_struct(task);
533
534	return count;
535}
536
537static const struct file_operations proc_lstats_operations = {
538	.open		= lstats_open,
539	.read		= seq_read,
540	.write		= lstats_write,
541	.llseek		= seq_lseek,
542	.release	= single_release,
543};
544
545#endif
546
547static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
548			  struct pid *pid, struct task_struct *task)
549{
550	unsigned long totalpages = totalram_pages() + total_swap_pages;
551	unsigned long points = 0;
552	long badness;
553
554	badness = oom_badness(task, totalpages);
555	/*
556	 * Special case OOM_SCORE_ADJ_MIN for all others scale the
557	 * badness value into [0, 2000] range which we have been
558	 * exporting for a long time so userspace might depend on it.
559	 */
560	if (badness != LONG_MIN)
561		points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3;
562
563	seq_printf(m, "%lu\n", points);
564
565	return 0;
566}
567
568struct limit_names {
569	const char *name;
570	const char *unit;
571};
572
573static const struct limit_names lnames[RLIM_NLIMITS] = {
574	[RLIMIT_CPU] = {"Max cpu time", "seconds"},
575	[RLIMIT_FSIZE] = {"Max file size", "bytes"},
576	[RLIMIT_DATA] = {"Max data size", "bytes"},
577	[RLIMIT_STACK] = {"Max stack size", "bytes"},
578	[RLIMIT_CORE] = {"Max core file size", "bytes"},
579	[RLIMIT_RSS] = {"Max resident set", "bytes"},
580	[RLIMIT_NPROC] = {"Max processes", "processes"},
581	[RLIMIT_NOFILE] = {"Max open files", "files"},
582	[RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
583	[RLIMIT_AS] = {"Max address space", "bytes"},
584	[RLIMIT_LOCKS] = {"Max file locks", "locks"},
585	[RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
586	[RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
587	[RLIMIT_NICE] = {"Max nice priority", NULL},
588	[RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
589	[RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
590};
591
592/* Display limits for a process */
593static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
594			   struct pid *pid, struct task_struct *task)
595{
596	unsigned int i;
597	unsigned long flags;
598
599	struct rlimit rlim[RLIM_NLIMITS];
600
601	if (!lock_task_sighand(task, &flags))
602		return 0;
603	memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
604	unlock_task_sighand(task, &flags);
605
606	/*
607	 * print the file header
608	 */
609	seq_puts(m, "Limit                     "
610		"Soft Limit           "
611		"Hard Limit           "
612		"Units     \n");
613
614	for (i = 0; i < RLIM_NLIMITS; i++) {
615		if (rlim[i].rlim_cur == RLIM_INFINITY)
616			seq_printf(m, "%-25s %-20s ",
617				   lnames[i].name, "unlimited");
618		else
619			seq_printf(m, "%-25s %-20lu ",
620				   lnames[i].name, rlim[i].rlim_cur);
621
622		if (rlim[i].rlim_max == RLIM_INFINITY)
623			seq_printf(m, "%-20s ", "unlimited");
624		else
625			seq_printf(m, "%-20lu ", rlim[i].rlim_max);
626
627		if (lnames[i].unit)
628			seq_printf(m, "%-10s\n", lnames[i].unit);
629		else
630			seq_putc(m, '\n');
631	}
632
633	return 0;
634}
635
636#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
637static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
638			    struct pid *pid, struct task_struct *task)
639{
640	struct syscall_info info;
641	u64 *args = &info.data.args[0];
642	int res;
643
644	res = lock_trace(task);
645	if (res)
646		return res;
647
648	if (task_current_syscall(task, &info))
649		seq_puts(m, "running\n");
650	else if (info.data.nr < 0)
651		seq_printf(m, "%d 0x%llx 0x%llx\n",
652			   info.data.nr, info.sp, info.data.instruction_pointer);
653	else
654		seq_printf(m,
655		       "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
656		       info.data.nr,
657		       args[0], args[1], args[2], args[3], args[4], args[5],
658		       info.sp, info.data.instruction_pointer);
659	unlock_trace(task);
660
661	return 0;
662}
663#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
664
665/************************************************************************/
666/*                       Here the fs part begins                        */
667/************************************************************************/
668
669/* permission checks */
670static int proc_fd_access_allowed(struct inode *inode)
671{
672	struct task_struct *task;
673	int allowed = 0;
674	/* Allow access to a task's file descriptors if it is us or we
675	 * may use ptrace attach to the process and find out that
676	 * information.
677	 */
678	task = get_proc_task(inode);
679	if (task) {
680		allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
681		put_task_struct(task);
682	}
683	return allowed;
684}
685
686int proc_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
687		 struct iattr *attr)
688{
689	int error;
690	struct inode *inode = d_inode(dentry);
691
692	if (attr->ia_valid & ATTR_MODE)
693		return -EPERM;
694
695	error = setattr_prepare(&init_user_ns, dentry, attr);
696	if (error)
697		return error;
698
699	setattr_copy(&init_user_ns, inode, attr);
700	mark_inode_dirty(inode);
701	return 0;
702}
703
704/*
705 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
706 * or euid/egid (for hide_pid_min=2)?
707 */
708static bool has_pid_permissions(struct proc_fs_info *fs_info,
709				 struct task_struct *task,
710				 enum proc_hidepid hide_pid_min)
711{
712	/*
713	 * If 'hidpid' mount option is set force a ptrace check,
714	 * we indicate that we are using a filesystem syscall
715	 * by passing PTRACE_MODE_READ_FSCREDS
716	 */
717	if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE)
718		return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
719
720	if (fs_info->hide_pid < hide_pid_min)
721		return true;
722	if (in_group_p(fs_info->pid_gid))
723		return true;
724	return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
725}
726
727
728static int proc_pid_permission(struct user_namespace *mnt_userns,
729			       struct inode *inode, int mask)
730{
731	struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
732	struct task_struct *task;
733	bool has_perms;
734
735	task = get_proc_task(inode);
736	if (!task)
737		return -ESRCH;
738	has_perms = has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS);
739	put_task_struct(task);
740
741	if (!has_perms) {
742		if (fs_info->hide_pid == HIDEPID_INVISIBLE) {
743			/*
744			 * Let's make getdents(), stat(), and open()
745			 * consistent with each other.  If a process
746			 * may not stat() a file, it shouldn't be seen
747			 * in procfs at all.
748			 */
749			return -ENOENT;
750		}
751
752		return -EPERM;
753	}
754	return generic_permission(&init_user_ns, inode, mask);
755}
756
757
758
759static const struct inode_operations proc_def_inode_operations = {
760	.setattr	= proc_setattr,
761};
762
763static int proc_single_show(struct seq_file *m, void *v)
764{
765	struct inode *inode = m->private;
766	struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
767	struct pid *pid = proc_pid(inode);
768	struct task_struct *task;
769	int ret;
770
771	task = get_pid_task(pid, PIDTYPE_PID);
772	if (!task)
773		return -ESRCH;
774
775	ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
776
777	put_task_struct(task);
778	return ret;
779}
780
781static int proc_single_open(struct inode *inode, struct file *filp)
782{
783	return single_open(filp, proc_single_show, inode);
784}
785
786static const struct file_operations proc_single_file_operations = {
787	.open		= proc_single_open,
788	.read		= seq_read,
789	.llseek		= seq_lseek,
790	.release	= single_release,
791};
792
793
794struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
795{
796	struct task_struct *task = get_proc_task(inode);
797	struct mm_struct *mm = ERR_PTR(-ESRCH);
798
799	if (task) {
800		mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
801		put_task_struct(task);
802
803		if (!IS_ERR_OR_NULL(mm)) {
804			/* ensure this mm_struct can't be freed */
805			mmgrab(mm);
806			/* but do not pin its memory */
807			mmput(mm);
808		}
809	}
810
811	return mm;
812}
813
814static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
815{
816	struct mm_struct *mm = proc_mem_open(inode, mode);
817
818	if (IS_ERR(mm))
819		return PTR_ERR(mm);
820
821	file->private_data = mm;
822	return 0;
823}
824
825static int mem_open(struct inode *inode, struct file *file)
826{
827	int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
828
829	/* OK to pass negative loff_t, we can catch out-of-range */
830	file->f_mode |= FMODE_UNSIGNED_OFFSET;
831
832	return ret;
833}
834
835static ssize_t mem_rw(struct file *file, char __user *buf,
836			size_t count, loff_t *ppos, int write)
837{
838	struct mm_struct *mm = file->private_data;
839	unsigned long addr = *ppos;
840	ssize_t copied;
841	char *page;
842	unsigned int flags;
843
844	if (!mm)
845		return 0;
846
847	page = (char *)__get_free_page(GFP_KERNEL);
848	if (!page)
849		return -ENOMEM;
850
851	copied = 0;
852	if (!mmget_not_zero(mm))
853		goto free;
854
855	flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
856
857	while (count > 0) {
858		size_t this_len = min_t(size_t, count, PAGE_SIZE);
859
860		if (write && copy_from_user(page, buf, this_len)) {
861			copied = -EFAULT;
862			break;
863		}
864
865		this_len = access_remote_vm(mm, addr, page, this_len, flags);
866		if (!this_len) {
867			if (!copied)
868				copied = -EIO;
869			break;
870		}
871
872		if (!write && copy_to_user(buf, page, this_len)) {
873			copied = -EFAULT;
874			break;
875		}
876
877		buf += this_len;
878		addr += this_len;
879		copied += this_len;
880		count -= this_len;
881	}
882	*ppos = addr;
883
884	mmput(mm);
885free:
886	free_page((unsigned long) page);
887	return copied;
888}
889
890static ssize_t mem_read(struct file *file, char __user *buf,
891			size_t count, loff_t *ppos)
892{
893	return mem_rw(file, buf, count, ppos, 0);
894}
895
896static ssize_t mem_write(struct file *file, const char __user *buf,
897			 size_t count, loff_t *ppos)
898{
899	return mem_rw(file, (char __user*)buf, count, ppos, 1);
900}
901
902loff_t mem_lseek(struct file *file, loff_t offset, int orig)
903{
904	switch (orig) {
905	case 0:
906		file->f_pos = offset;
907		break;
908	case 1:
909		file->f_pos += offset;
910		break;
911	default:
912		return -EINVAL;
913	}
914	force_successful_syscall_return();
915	return file->f_pos;
916}
917
918static int mem_release(struct inode *inode, struct file *file)
919{
920	struct mm_struct *mm = file->private_data;
921	if (mm)
922		mmdrop(mm);
923	return 0;
924}
925
926static const struct file_operations proc_mem_operations = {
927	.llseek		= mem_lseek,
928	.read		= mem_read,
929	.write		= mem_write,
930	.open		= mem_open,
931	.release	= mem_release,
932};
933
934static int environ_open(struct inode *inode, struct file *file)
935{
936	return __mem_open(inode, file, PTRACE_MODE_READ);
937}
938
939static ssize_t environ_read(struct file *file, char __user *buf,
940			size_t count, loff_t *ppos)
941{
942	char *page;
943	unsigned long src = *ppos;
944	int ret = 0;
945	struct mm_struct *mm = file->private_data;
946	unsigned long env_start, env_end;
947
948	/* Ensure the process spawned far enough to have an environment. */
949	if (!mm || !mm->env_end)
950		return 0;
951
952	page = (char *)__get_free_page(GFP_KERNEL);
953	if (!page)
954		return -ENOMEM;
955
956	ret = 0;
957	if (!mmget_not_zero(mm))
958		goto free;
959
960	spin_lock(&mm->arg_lock);
961	env_start = mm->env_start;
962	env_end = mm->env_end;
963	spin_unlock(&mm->arg_lock);
964
965	while (count > 0) {
966		size_t this_len, max_len;
967		int retval;
968
969		if (src >= (env_end - env_start))
970			break;
971
972		this_len = env_end - (env_start + src);
973
974		max_len = min_t(size_t, PAGE_SIZE, count);
975		this_len = min(max_len, this_len);
976
977		retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
978
979		if (retval <= 0) {
980			ret = retval;
981			break;
982		}
983
984		if (copy_to_user(buf, page, retval)) {
985			ret = -EFAULT;
986			break;
987		}
988
989		ret += retval;
990		src += retval;
991		buf += retval;
992		count -= retval;
993	}
994	*ppos = src;
995	mmput(mm);
996
997free:
998	free_page((unsigned long) page);
999	return ret;
1000}
1001
1002static const struct file_operations proc_environ_operations = {
1003	.open		= environ_open,
1004	.read		= environ_read,
1005	.llseek		= generic_file_llseek,
1006	.release	= mem_release,
1007};
1008
1009static int auxv_open(struct inode *inode, struct file *file)
1010{
1011	return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1012}
1013
1014static ssize_t auxv_read(struct file *file, char __user *buf,
1015			size_t count, loff_t *ppos)
1016{
1017	struct mm_struct *mm = file->private_data;
1018	unsigned int nwords = 0;
1019
1020	if (!mm)
1021		return 0;
1022	do {
1023		nwords += 2;
1024	} while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1025	return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1026				       nwords * sizeof(mm->saved_auxv[0]));
1027}
1028
1029static const struct file_operations proc_auxv_operations = {
1030	.open		= auxv_open,
1031	.read		= auxv_read,
1032	.llseek		= generic_file_llseek,
1033	.release	= mem_release,
1034};
1035
1036static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1037			    loff_t *ppos)
1038{
1039	struct task_struct *task = get_proc_task(file_inode(file));
1040	char buffer[PROC_NUMBUF];
1041	int oom_adj = OOM_ADJUST_MIN;
1042	size_t len;
1043
1044	if (!task)
1045		return -ESRCH;
1046	if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1047		oom_adj = OOM_ADJUST_MAX;
1048	else
1049		oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1050			  OOM_SCORE_ADJ_MAX;
1051	put_task_struct(task);
1052	if (oom_adj > OOM_ADJUST_MAX)
1053		oom_adj = OOM_ADJUST_MAX;
1054	len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1055	return simple_read_from_buffer(buf, count, ppos, buffer, len);
1056}
1057
1058static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1059{
1060	struct mm_struct *mm = NULL;
1061	struct task_struct *task;
1062	int err = 0;
1063
1064	task = get_proc_task(file_inode(file));
1065	if (!task)
1066		return -ESRCH;
1067
1068	mutex_lock(&oom_adj_mutex);
1069	if (legacy) {
1070		if (oom_adj < task->signal->oom_score_adj &&
1071				!capable(CAP_SYS_RESOURCE)) {
1072			err = -EACCES;
1073			goto err_unlock;
1074		}
1075		/*
1076		 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1077		 * /proc/pid/oom_score_adj instead.
1078		 */
1079		pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1080			  current->comm, task_pid_nr(current), task_pid_nr(task),
1081			  task_pid_nr(task));
1082	} else {
1083		if ((short)oom_adj < task->signal->oom_score_adj_min &&
1084				!capable(CAP_SYS_RESOURCE)) {
1085			err = -EACCES;
1086			goto err_unlock;
1087		}
1088	}
1089
1090	/*
1091	 * Make sure we will check other processes sharing the mm if this is
1092	 * not vfrok which wants its own oom_score_adj.
1093	 * pin the mm so it doesn't go away and get reused after task_unlock
1094	 */
1095	if (!task->vfork_done) {
1096		struct task_struct *p = find_lock_task_mm(task);
1097
1098		if (p) {
1099			if (test_bit(MMF_MULTIPROCESS, &p->mm->flags)) {
1100				mm = p->mm;
1101				mmgrab(mm);
1102			}
1103			task_unlock(p);
1104		}
1105	}
1106
1107	task->signal->oom_score_adj = oom_adj;
1108	if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1109		task->signal->oom_score_adj_min = (short)oom_adj;
1110	trace_oom_score_adj_update(task);
1111
1112	if (mm) {
1113		struct task_struct *p;
1114
1115		rcu_read_lock();
1116		for_each_process(p) {
1117			if (same_thread_group(task, p))
1118				continue;
1119
1120			/* do not touch kernel threads or the global init */
1121			if (p->flags & PF_KTHREAD || is_global_init(p))
1122				continue;
1123
1124			task_lock(p);
1125			if (!p->vfork_done && process_shares_mm(p, mm)) {
1126				p->signal->oom_score_adj = oom_adj;
1127				if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1128					p->signal->oom_score_adj_min = (short)oom_adj;
1129			}
1130			task_unlock(p);
1131		}
1132		rcu_read_unlock();
1133		mmdrop(mm);
1134	}
1135err_unlock:
1136	mutex_unlock(&oom_adj_mutex);
1137	put_task_struct(task);
1138	return err;
1139}
1140
1141/*
1142 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1143 * kernels.  The effective policy is defined by oom_score_adj, which has a
1144 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1145 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1146 * Processes that become oom disabled via oom_adj will still be oom disabled
1147 * with this implementation.
1148 *
1149 * oom_adj cannot be removed since existing userspace binaries use it.
1150 */
1151static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1152			     size_t count, loff_t *ppos)
1153{
1154	char buffer[PROC_NUMBUF];
1155	int oom_adj;
1156	int err;
1157
1158	memset(buffer, 0, sizeof(buffer));
1159	if (count > sizeof(buffer) - 1)
1160		count = sizeof(buffer) - 1;
1161	if (copy_from_user(buffer, buf, count)) {
1162		err = -EFAULT;
1163		goto out;
1164	}
1165
1166	err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1167	if (err)
1168		goto out;
1169	if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1170	     oom_adj != OOM_DISABLE) {
1171		err = -EINVAL;
1172		goto out;
1173	}
1174
1175	/*
1176	 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1177	 * value is always attainable.
1178	 */
1179	if (oom_adj == OOM_ADJUST_MAX)
1180		oom_adj = OOM_SCORE_ADJ_MAX;
1181	else
1182		oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1183
1184	err = __set_oom_adj(file, oom_adj, true);
1185out:
1186	return err < 0 ? err : count;
1187}
1188
1189static const struct file_operations proc_oom_adj_operations = {
1190	.read		= oom_adj_read,
1191	.write		= oom_adj_write,
1192	.llseek		= generic_file_llseek,
1193};
1194
1195static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1196					size_t count, loff_t *ppos)
1197{
1198	struct task_struct *task = get_proc_task(file_inode(file));
1199	char buffer[PROC_NUMBUF];
1200	short oom_score_adj = OOM_SCORE_ADJ_MIN;
1201	size_t len;
1202
1203	if (!task)
1204		return -ESRCH;
1205	oom_score_adj = task->signal->oom_score_adj;
1206	put_task_struct(task);
1207	len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1208	return simple_read_from_buffer(buf, count, ppos, buffer, len);
1209}
1210
1211static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1212					size_t count, loff_t *ppos)
1213{
1214	char buffer[PROC_NUMBUF];
1215	int oom_score_adj;
1216	int err;
1217
1218	memset(buffer, 0, sizeof(buffer));
1219	if (count > sizeof(buffer) - 1)
1220		count = sizeof(buffer) - 1;
1221	if (copy_from_user(buffer, buf, count)) {
1222		err = -EFAULT;
1223		goto out;
1224	}
1225
1226	err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1227	if (err)
1228		goto out;
1229	if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1230			oom_score_adj > OOM_SCORE_ADJ_MAX) {
1231		err = -EINVAL;
1232		goto out;
1233	}
1234
1235	err = __set_oom_adj(file, oom_score_adj, false);
1236out:
1237	return err < 0 ? err : count;
1238}
1239
1240static const struct file_operations proc_oom_score_adj_operations = {
1241	.read		= oom_score_adj_read,
1242	.write		= oom_score_adj_write,
1243	.llseek		= default_llseek,
1244};
1245
1246#ifdef CONFIG_AUDIT
1247#define TMPBUFLEN 11
1248static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1249				  size_t count, loff_t *ppos)
1250{
1251	struct inode * inode = file_inode(file);
1252	struct task_struct *task = get_proc_task(inode);
1253	ssize_t length;
1254	char tmpbuf[TMPBUFLEN];
1255
1256	if (!task)
1257		return -ESRCH;
1258	length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1259			   from_kuid(file->f_cred->user_ns,
1260				     audit_get_loginuid(task)));
1261	put_task_struct(task);
1262	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1263}
1264
1265static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1266				   size_t count, loff_t *ppos)
1267{
1268	struct inode * inode = file_inode(file);
1269	uid_t loginuid;
1270	kuid_t kloginuid;
1271	int rv;
1272
1273	/* Don't let kthreads write their own loginuid */
1274	if (current->flags & PF_KTHREAD)
1275		return -EPERM;
1276
1277	rcu_read_lock();
1278	if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1279		rcu_read_unlock();
1280		return -EPERM;
1281	}
1282	rcu_read_unlock();
1283
1284	if (*ppos != 0) {
1285		/* No partial writes. */
1286		return -EINVAL;
1287	}
1288
1289	rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1290	if (rv < 0)
1291		return rv;
1292
1293	/* is userspace tring to explicitly UNSET the loginuid? */
1294	if (loginuid == AUDIT_UID_UNSET) {
1295		kloginuid = INVALID_UID;
1296	} else {
1297		kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1298		if (!uid_valid(kloginuid))
1299			return -EINVAL;
1300	}
1301
1302	rv = audit_set_loginuid(kloginuid);
1303	if (rv < 0)
1304		return rv;
1305	return count;
1306}
1307
1308static const struct file_operations proc_loginuid_operations = {
1309	.read		= proc_loginuid_read,
1310	.write		= proc_loginuid_write,
1311	.llseek		= generic_file_llseek,
1312};
1313
1314static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1315				  size_t count, loff_t *ppos)
1316{
1317	struct inode * inode = file_inode(file);
1318	struct task_struct *task = get_proc_task(inode);
1319	ssize_t length;
1320	char tmpbuf[TMPBUFLEN];
1321
1322	if (!task)
1323		return -ESRCH;
1324	length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1325				audit_get_sessionid(task));
1326	put_task_struct(task);
1327	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1328}
1329
1330static const struct file_operations proc_sessionid_operations = {
1331	.read		= proc_sessionid_read,
1332	.llseek		= generic_file_llseek,
1333};
1334#endif
1335
1336#ifdef CONFIG_FAULT_INJECTION
1337static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1338				      size_t count, loff_t *ppos)
1339{
1340	struct task_struct *task = get_proc_task(file_inode(file));
1341	char buffer[PROC_NUMBUF];
1342	size_t len;
1343	int make_it_fail;
1344
1345	if (!task)
1346		return -ESRCH;
1347	make_it_fail = task->make_it_fail;
1348	put_task_struct(task);
1349
1350	len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1351
1352	return simple_read_from_buffer(buf, count, ppos, buffer, len);
1353}
1354
1355static ssize_t proc_fault_inject_write(struct file * file,
1356			const char __user * buf, size_t count, loff_t *ppos)
1357{
1358	struct task_struct *task;
1359	char buffer[PROC_NUMBUF];
1360	int make_it_fail;
1361	int rv;
1362
1363	if (!capable(CAP_SYS_RESOURCE))
1364		return -EPERM;
1365	memset(buffer, 0, sizeof(buffer));
1366	if (count > sizeof(buffer) - 1)
1367		count = sizeof(buffer) - 1;
1368	if (copy_from_user(buffer, buf, count))
1369		return -EFAULT;
1370	rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1371	if (rv < 0)
1372		return rv;
1373	if (make_it_fail < 0 || make_it_fail > 1)
1374		return -EINVAL;
1375
1376	task = get_proc_task(file_inode(file));
1377	if (!task)
1378		return -ESRCH;
1379	task->make_it_fail = make_it_fail;
1380	put_task_struct(task);
1381
1382	return count;
1383}
1384
1385static const struct file_operations proc_fault_inject_operations = {
1386	.read		= proc_fault_inject_read,
1387	.write		= proc_fault_inject_write,
1388	.llseek		= generic_file_llseek,
1389};
1390
1391static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1392				   size_t count, loff_t *ppos)
1393{
1394	struct task_struct *task;
1395	int err;
1396	unsigned int n;
1397
1398	err = kstrtouint_from_user(buf, count, 0, &n);
1399	if (err)
1400		return err;
1401
1402	task = get_proc_task(file_inode(file));
1403	if (!task)
1404		return -ESRCH;
1405	task->fail_nth = n;
1406	put_task_struct(task);
1407
1408	return count;
1409}
1410
1411static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1412				  size_t count, loff_t *ppos)
1413{
1414	struct task_struct *task;
1415	char numbuf[PROC_NUMBUF];
1416	ssize_t len;
1417
1418	task = get_proc_task(file_inode(file));
1419	if (!task)
1420		return -ESRCH;
1421	len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1422	put_task_struct(task);
1423	return simple_read_from_buffer(buf, count, ppos, numbuf, len);
1424}
1425
1426static const struct file_operations proc_fail_nth_operations = {
1427	.read		= proc_fail_nth_read,
1428	.write		= proc_fail_nth_write,
1429};
1430#endif
1431
1432
1433#ifdef CONFIG_SCHED_DEBUG
1434/*
1435 * Print out various scheduling related per-task fields:
1436 */
1437static int sched_show(struct seq_file *m, void *v)
1438{
1439	struct inode *inode = m->private;
1440	struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
1441	struct task_struct *p;
1442
1443	p = get_proc_task(inode);
1444	if (!p)
1445		return -ESRCH;
1446	proc_sched_show_task(p, ns, m);
1447
1448	put_task_struct(p);
1449
1450	return 0;
1451}
1452
1453static ssize_t
1454sched_write(struct file *file, const char __user *buf,
1455	    size_t count, loff_t *offset)
1456{
1457	struct inode *inode = file_inode(file);
1458	struct task_struct *p;
1459
1460	p = get_proc_task(inode);
1461	if (!p)
1462		return -ESRCH;
1463	proc_sched_set_task(p);
1464
1465	put_task_struct(p);
1466
1467	return count;
1468}
1469
1470static int sched_open(struct inode *inode, struct file *filp)
1471{
1472	return single_open(filp, sched_show, inode);
1473}
1474
1475static const struct file_operations proc_pid_sched_operations = {
1476	.open		= sched_open,
1477	.read		= seq_read,
1478	.write		= sched_write,
1479	.llseek		= seq_lseek,
1480	.release	= single_release,
1481};
1482
1483#endif
1484
1485#ifdef CONFIG_SCHED_AUTOGROUP
1486/*
1487 * Print out autogroup related information:
1488 */
1489static int sched_autogroup_show(struct seq_file *m, void *v)
1490{
1491	struct inode *inode = m->private;
1492	struct task_struct *p;
1493
1494	p = get_proc_task(inode);
1495	if (!p)
1496		return -ESRCH;
1497	proc_sched_autogroup_show_task(p, m);
1498
1499	put_task_struct(p);
1500
1501	return 0;
1502}
1503
1504static ssize_t
1505sched_autogroup_write(struct file *file, const char __user *buf,
1506	    size_t count, loff_t *offset)
1507{
1508	struct inode *inode = file_inode(file);
1509	struct task_struct *p;
1510	char buffer[PROC_NUMBUF];
1511	int nice;
1512	int err;
1513
1514	memset(buffer, 0, sizeof(buffer));
1515	if (count > sizeof(buffer) - 1)
1516		count = sizeof(buffer) - 1;
1517	if (copy_from_user(buffer, buf, count))
1518		return -EFAULT;
1519
1520	err = kstrtoint(strstrip(buffer), 0, &nice);
1521	if (err < 0)
1522		return err;
1523
1524	p = get_proc_task(inode);
1525	if (!p)
1526		return -ESRCH;
1527
1528	err = proc_sched_autogroup_set_nice(p, nice);
1529	if (err)
1530		count = err;
1531
1532	put_task_struct(p);
1533
1534	return count;
1535}
1536
1537static int sched_autogroup_open(struct inode *inode, struct file *filp)
1538{
1539	int ret;
1540
1541	ret = single_open(filp, sched_autogroup_show, NULL);
1542	if (!ret) {
1543		struct seq_file *m = filp->private_data;
1544
1545		m->private = inode;
1546	}
1547	return ret;
1548}
1549
1550static const struct file_operations proc_pid_sched_autogroup_operations = {
1551	.open		= sched_autogroup_open,
1552	.read		= seq_read,
1553	.write		= sched_autogroup_write,
1554	.llseek		= seq_lseek,
1555	.release	= single_release,
1556};
1557
1558#endif /* CONFIG_SCHED_AUTOGROUP */
1559
1560#ifdef CONFIG_TIME_NS
1561static int timens_offsets_show(struct seq_file *m, void *v)
1562{
1563	struct task_struct *p;
1564
1565	p = get_proc_task(file_inode(m->file));
1566	if (!p)
1567		return -ESRCH;
1568	proc_timens_show_offsets(p, m);
1569
1570	put_task_struct(p);
1571
1572	return 0;
1573}
1574
1575static ssize_t timens_offsets_write(struct file *file, const char __user *buf,
1576				    size_t count, loff_t *ppos)
1577{
1578	struct inode *inode = file_inode(file);
1579	struct proc_timens_offset offsets[2];
1580	char *kbuf = NULL, *pos, *next_line;
1581	struct task_struct *p;
1582	int ret, noffsets;
1583
1584	/* Only allow < page size writes at the beginning of the file */
1585	if ((*ppos != 0) || (count >= PAGE_SIZE))
1586		return -EINVAL;
1587
1588	/* Slurp in the user data */
1589	kbuf = memdup_user_nul(buf, count);
1590	if (IS_ERR(kbuf))
1591		return PTR_ERR(kbuf);
1592
1593	/* Parse the user data */
1594	ret = -EINVAL;
1595	noffsets = 0;
1596	for (pos = kbuf; pos; pos = next_line) {
1597		struct proc_timens_offset *off = &offsets[noffsets];
1598		char clock[10];
1599		int err;
1600
1601		/* Find the end of line and ensure we don't look past it */
1602		next_line = strchr(pos, '\n');
1603		if (next_line) {
1604			*next_line = '\0';
1605			next_line++;
1606			if (*next_line == '\0')
1607				next_line = NULL;
1608		}
1609
1610		err = sscanf(pos, "%9s %lld %lu", clock,
1611				&off->val.tv_sec, &off->val.tv_nsec);
1612		if (err != 3 || off->val.tv_nsec >= NSEC_PER_SEC)
1613			goto out;
1614
1615		clock[sizeof(clock) - 1] = 0;
1616		if (strcmp(clock, "monotonic") == 0 ||
1617		    strcmp(clock, __stringify(CLOCK_MONOTONIC)) == 0)
1618			off->clockid = CLOCK_MONOTONIC;
1619		else if (strcmp(clock, "boottime") == 0 ||
1620			 strcmp(clock, __stringify(CLOCK_BOOTTIME)) == 0)
1621			off->clockid = CLOCK_BOOTTIME;
1622		else
1623			goto out;
1624
1625		noffsets++;
1626		if (noffsets == ARRAY_SIZE(offsets)) {
1627			if (next_line)
1628				count = next_line - kbuf;
1629			break;
1630		}
1631	}
1632
1633	ret = -ESRCH;
1634	p = get_proc_task(inode);
1635	if (!p)
1636		goto out;
1637	ret = proc_timens_set_offset(file, p, offsets, noffsets);
1638	put_task_struct(p);
1639	if (ret)
1640		goto out;
1641
1642	ret = count;
1643out:
1644	kfree(kbuf);
1645	return ret;
1646}
1647
1648static int timens_offsets_open(struct inode *inode, struct file *filp)
1649{
1650	return single_open(filp, timens_offsets_show, inode);
1651}
1652
1653static const struct file_operations proc_timens_offsets_operations = {
1654	.open		= timens_offsets_open,
1655	.read		= seq_read,
1656	.write		= timens_offsets_write,
1657	.llseek		= seq_lseek,
1658	.release	= single_release,
1659};
1660#endif /* CONFIG_TIME_NS */
1661
1662static ssize_t comm_write(struct file *file, const char __user *buf,
1663				size_t count, loff_t *offset)
1664{
1665	struct inode *inode = file_inode(file);
1666	struct task_struct *p;
1667	char buffer[TASK_COMM_LEN];
1668	const size_t maxlen = sizeof(buffer) - 1;
1669
1670	memset(buffer, 0, sizeof(buffer));
1671	if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1672		return -EFAULT;
1673
1674	p = get_proc_task(inode);
1675	if (!p)
1676		return -ESRCH;
1677
1678	if (same_thread_group(current, p)) {
1679		set_task_comm(p, buffer);
1680		proc_comm_connector(p);
1681	}
1682	else
1683		count = -EINVAL;
1684
1685	put_task_struct(p);
1686
1687	return count;
1688}
1689
1690static int comm_show(struct seq_file *m, void *v)
1691{
1692	struct inode *inode = m->private;
1693	struct task_struct *p;
1694
1695	p = get_proc_task(inode);
1696	if (!p)
1697		return -ESRCH;
1698
1699	proc_task_name(m, p, false);
1700	seq_putc(m, '\n');
1701
1702	put_task_struct(p);
1703
1704	return 0;
1705}
1706
1707static int comm_open(struct inode *inode, struct file *filp)
1708{
1709	return single_open(filp, comm_show, inode);
1710}
1711
1712static const struct file_operations proc_pid_set_comm_operations = {
1713	.open		= comm_open,
1714	.read		= seq_read,
1715	.write		= comm_write,
1716	.llseek		= seq_lseek,
1717	.release	= single_release,
1718};
1719
1720static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1721{
1722	struct task_struct *task;
1723	struct file *exe_file;
1724
1725	task = get_proc_task(d_inode(dentry));
1726	if (!task)
1727		return -ENOENT;
1728	exe_file = get_task_exe_file(task);
1729	put_task_struct(task);
1730	if (exe_file) {
1731		*exe_path = exe_file->f_path;
1732		path_get(&exe_file->f_path);
1733		fput(exe_file);
1734		return 0;
1735	} else
1736		return -ENOENT;
1737}
1738
1739static const char *proc_pid_get_link(struct dentry *dentry,
1740				     struct inode *inode,
1741				     struct delayed_call *done)
1742{
1743	struct path path;
1744	int error = -EACCES;
1745
1746	if (!dentry)
1747		return ERR_PTR(-ECHILD);
1748
1749	/* Are we allowed to snoop on the tasks file descriptors? */
1750	if (!proc_fd_access_allowed(inode))
1751		goto out;
1752
1753	error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1754	if (error)
1755		goto out;
1756
1757	error = nd_jump_link(&path);
1758out:
1759	return ERR_PTR(error);
1760}
1761
1762static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1763{
1764	char *tmp = (char *)__get_free_page(GFP_KERNEL);
1765	char *pathname;
1766	int len;
1767
1768	if (!tmp)
1769		return -ENOMEM;
1770
1771	pathname = d_path(path, tmp, PAGE_SIZE);
1772	len = PTR_ERR(pathname);
1773	if (IS_ERR(pathname))
1774		goto out;
1775	len = tmp + PAGE_SIZE - 1 - pathname;
1776
1777	if (len > buflen)
1778		len = buflen;
1779	if (copy_to_user(buffer, pathname, len))
1780		len = -EFAULT;
1781 out:
1782	free_page((unsigned long)tmp);
1783	return len;
1784}
1785
1786static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1787{
1788	int error = -EACCES;
1789	struct inode *inode = d_inode(dentry);
1790	struct path path;
1791
1792	/* Are we allowed to snoop on the tasks file descriptors? */
1793	if (!proc_fd_access_allowed(inode))
1794		goto out;
1795
1796	error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1797	if (error)
1798		goto out;
1799
1800	error = do_proc_readlink(&path, buffer, buflen);
1801	path_put(&path);
1802out:
1803	return error;
1804}
1805
1806const struct inode_operations proc_pid_link_inode_operations = {
1807	.readlink	= proc_pid_readlink,
1808	.get_link	= proc_pid_get_link,
1809	.setattr	= proc_setattr,
1810};
1811
1812
1813/* building an inode */
1814
1815void task_dump_owner(struct task_struct *task, umode_t mode,
1816		     kuid_t *ruid, kgid_t *rgid)
1817{
1818	/* Depending on the state of dumpable compute who should own a
1819	 * proc file for a task.
1820	 */
1821	const struct cred *cred;
1822	kuid_t uid;
1823	kgid_t gid;
1824
1825	if (unlikely(task->flags & PF_KTHREAD)) {
1826		*ruid = GLOBAL_ROOT_UID;
1827		*rgid = GLOBAL_ROOT_GID;
1828		return;
1829	}
1830
1831	/* Default to the tasks effective ownership */
1832	rcu_read_lock();
1833	cred = __task_cred(task);
1834	uid = cred->euid;
1835	gid = cred->egid;
1836	rcu_read_unlock();
1837
1838	/*
1839	 * Before the /proc/pid/status file was created the only way to read
1840	 * the effective uid of a /process was to stat /proc/pid.  Reading
1841	 * /proc/pid/status is slow enough that procps and other packages
1842	 * kept stating /proc/pid.  To keep the rules in /proc simple I have
1843	 * made this apply to all per process world readable and executable
1844	 * directories.
1845	 */
1846	if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1847		struct mm_struct *mm;
1848		task_lock(task);
1849		mm = task->mm;
1850		/* Make non-dumpable tasks owned by some root */
1851		if (mm) {
1852			if (get_dumpable(mm) != SUID_DUMP_USER) {
1853				struct user_namespace *user_ns = mm->user_ns;
1854
1855				uid = make_kuid(user_ns, 0);
1856				if (!uid_valid(uid))
1857					uid = GLOBAL_ROOT_UID;
1858
1859				gid = make_kgid(user_ns, 0);
1860				if (!gid_valid(gid))
1861					gid = GLOBAL_ROOT_GID;
1862			}
1863		} else {
1864			uid = GLOBAL_ROOT_UID;
1865			gid = GLOBAL_ROOT_GID;
1866		}
1867		task_unlock(task);
1868	}
1869	*ruid = uid;
1870	*rgid = gid;
1871}
1872
1873void proc_pid_evict_inode(struct proc_inode *ei)
1874{
1875	struct pid *pid = ei->pid;
1876
1877	if (S_ISDIR(ei->vfs_inode.i_mode)) {
1878		spin_lock(&pid->lock);
1879		hlist_del_init_rcu(&ei->sibling_inodes);
1880		spin_unlock(&pid->lock);
1881	}
1882
1883	put_pid(pid);
1884}
1885
1886struct inode *proc_pid_make_inode(struct super_block * sb,
1887				  struct task_struct *task, umode_t mode)
1888{
1889	struct inode * inode;
1890	struct proc_inode *ei;
1891	struct pid *pid;
1892
1893	/* We need a new inode */
1894
1895	inode = new_inode(sb);
1896	if (!inode)
1897		goto out;
1898
1899	/* Common stuff */
1900	ei = PROC_I(inode);
1901	inode->i_mode = mode;
1902	inode->i_ino = get_next_ino();
1903	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1904	inode->i_op = &proc_def_inode_operations;
1905
1906	/*
1907	 * grab the reference to task.
1908	 */
1909	pid = get_task_pid(task, PIDTYPE_PID);
1910	if (!pid)
1911		goto out_unlock;
1912
1913	/* Let the pid remember us for quick removal */
1914	ei->pid = pid;
1915	if (S_ISDIR(mode)) {
1916		spin_lock(&pid->lock);
1917		hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes);
1918		spin_unlock(&pid->lock);
1919	}
1920
1921	task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1922	security_task_to_inode(task, inode);
1923
1924out:
1925	return inode;
1926
1927out_unlock:
1928	iput(inode);
1929	return NULL;
1930}
1931
1932int pid_getattr(struct user_namespace *mnt_userns, const struct path *path,
1933		struct kstat *stat, u32 request_mask, unsigned int query_flags)
1934{
1935	struct inode *inode = d_inode(path->dentry);
1936	struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
1937	struct task_struct *task;
1938
1939	generic_fillattr(&init_user_ns, inode, stat);
1940
1941	stat->uid = GLOBAL_ROOT_UID;
1942	stat->gid = GLOBAL_ROOT_GID;
1943	rcu_read_lock();
1944	task = pid_task(proc_pid(inode), PIDTYPE_PID);
1945	if (task) {
1946		if (!has_pid_permissions(fs_info, task, HIDEPID_INVISIBLE)) {
1947			rcu_read_unlock();
1948			/*
1949			 * This doesn't prevent learning whether PID exists,
1950			 * it only makes getattr() consistent with readdir().
1951			 */
1952			return -ENOENT;
1953		}
1954		task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1955	}
1956	rcu_read_unlock();
1957	return 0;
1958}
1959
1960/* dentry stuff */
1961
1962/*
1963 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
1964 */
1965void pid_update_inode(struct task_struct *task, struct inode *inode)
1966{
1967	task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1968
1969	inode->i_mode &= ~(S_ISUID | S_ISGID);
1970	security_task_to_inode(task, inode);
1971}
1972
1973/*
1974 * Rewrite the inode's ownerships here because the owning task may have
1975 * performed a setuid(), etc.
1976 *
1977 */
1978static int pid_revalidate(struct dentry *dentry, unsigned int flags)
1979{
1980	struct inode *inode;
1981	struct task_struct *task;
1982
1983	if (flags & LOOKUP_RCU)
1984		return -ECHILD;
1985
1986	inode = d_inode(dentry);
1987	task = get_proc_task(inode);
1988
1989	if (task) {
1990		pid_update_inode(task, inode);
1991		put_task_struct(task);
1992		return 1;
1993	}
1994	return 0;
1995}
1996
1997static inline bool proc_inode_is_dead(struct inode *inode)
1998{
1999	return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
2000}
2001
2002int pid_delete_dentry(const struct dentry *dentry)
2003{
2004	/* Is the task we represent dead?
2005	 * If so, then don't put the dentry on the lru list,
2006	 * kill it immediately.
2007	 */
2008	return proc_inode_is_dead(d_inode(dentry));
2009}
2010
2011const struct dentry_operations pid_dentry_operations =
2012{
2013	.d_revalidate	= pid_revalidate,
2014	.d_delete	= pid_delete_dentry,
2015};
2016
2017/* Lookups */
2018
2019/*
2020 * Fill a directory entry.
2021 *
2022 * If possible create the dcache entry and derive our inode number and
2023 * file type from dcache entry.
2024 *
2025 * Since all of the proc inode numbers are dynamically generated, the inode
2026 * numbers do not exist until the inode is cache.  This means creating
2027 * the dcache entry in readdir is necessary to keep the inode numbers
2028 * reported by readdir in sync with the inode numbers reported
2029 * by stat.
2030 */
2031bool proc_fill_cache(struct file *file, struct dir_context *ctx,
2032	const char *name, unsigned int len,
2033	instantiate_t instantiate, struct task_struct *task, const void *ptr)
2034{
2035	struct dentry *child, *dir = file->f_path.dentry;
2036	struct qstr qname = QSTR_INIT(name, len);
2037	struct inode *inode;
2038	unsigned type = DT_UNKNOWN;
2039	ino_t ino = 1;
2040
2041	child = d_hash_and_lookup(dir, &qname);
2042	if (!child) {
2043		DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
2044		child = d_alloc_parallel(dir, &qname, &wq);
2045		if (IS_ERR(child))
2046			goto end_instantiate;
2047		if (d_in_lookup(child)) {
2048			struct dentry *res;
2049			res = instantiate(child, task, ptr);
2050			d_lookup_done(child);
2051			if (unlikely(res)) {
2052				dput(child);
2053				child = res;
2054				if (IS_ERR(child))
2055					goto end_instantiate;
2056			}
2057		}
2058	}
2059	inode = d_inode(child);
2060	ino = inode->i_ino;
2061	type = inode->i_mode >> 12;
2062	dput(child);
2063end_instantiate:
2064	return dir_emit(ctx, name, len, ino, type);
2065}
2066
2067/*
2068 * dname_to_vma_addr - maps a dentry name into two unsigned longs
2069 * which represent vma start and end addresses.
2070 */
2071static int dname_to_vma_addr(struct dentry *dentry,
2072			     unsigned long *start, unsigned long *end)
2073{
2074	const char *str = dentry->d_name.name;
2075	unsigned long long sval, eval;
2076	unsigned int len;
2077
2078	if (str[0] == '0' && str[1] != '-')
2079		return -EINVAL;
2080	len = _parse_integer(str, 16, &sval);
2081	if (len & KSTRTOX_OVERFLOW)
2082		return -EINVAL;
2083	if (sval != (unsigned long)sval)
2084		return -EINVAL;
2085	str += len;
2086
2087	if (*str != '-')
2088		return -EINVAL;
2089	str++;
2090
2091	if (str[0] == '0' && str[1])
2092		return -EINVAL;
2093	len = _parse_integer(str, 16, &eval);
2094	if (len & KSTRTOX_OVERFLOW)
2095		return -EINVAL;
2096	if (eval != (unsigned long)eval)
2097		return -EINVAL;
2098	str += len;
2099
2100	if (*str != '\0')
2101		return -EINVAL;
2102
2103	*start = sval;
2104	*end = eval;
2105
2106	return 0;
2107}
2108
2109static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
2110{
2111	unsigned long vm_start, vm_end;
2112	bool exact_vma_exists = false;
2113	struct mm_struct *mm = NULL;
2114	struct task_struct *task;
2115	struct inode *inode;
2116	int status = 0;
2117
2118	if (flags & LOOKUP_RCU)
2119		return -ECHILD;
2120
2121	inode = d_inode(dentry);
2122	task = get_proc_task(inode);
2123	if (!task)
2124		goto out_notask;
2125
2126	mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
2127	if (IS_ERR_OR_NULL(mm))
2128		goto out;
2129
2130	if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2131		status = mmap_read_lock_killable(mm);
2132		if (!status) {
2133			exact_vma_exists = !!find_exact_vma(mm, vm_start,
2134							    vm_end);
2135			mmap_read_unlock(mm);
2136		}
2137	}
2138
2139	mmput(mm);
2140
2141	if (exact_vma_exists) {
2142		task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
2143
2144		security_task_to_inode(task, inode);
2145		status = 1;
2146	}
2147
2148out:
2149	put_task_struct(task);
2150
2151out_notask:
2152	return status;
2153}
2154
2155static const struct dentry_operations tid_map_files_dentry_operations = {
2156	.d_revalidate	= map_files_d_revalidate,
2157	.d_delete	= pid_delete_dentry,
2158};
2159
2160static int map_files_get_link(struct dentry *dentry, struct path *path)
2161{
2162	unsigned long vm_start, vm_end;
2163	struct vm_area_struct *vma;
2164	struct task_struct *task;
2165	struct mm_struct *mm;
2166	int rc;
2167
2168	rc = -ENOENT;
2169	task = get_proc_task(d_inode(dentry));
2170	if (!task)
2171		goto out;
2172
2173	mm = get_task_mm(task);
2174	put_task_struct(task);
2175	if (!mm)
2176		goto out;
2177
2178	rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2179	if (rc)
2180		goto out_mmput;
2181
2182	rc = mmap_read_lock_killable(mm);
2183	if (rc)
2184		goto out_mmput;
2185
2186	rc = -ENOENT;
2187	vma = find_exact_vma(mm, vm_start, vm_end);
2188	if (vma && vma->vm_file) {
2189		*path = vma->vm_file->f_path;
2190		path_get(path);
2191		rc = 0;
2192	}
2193	mmap_read_unlock(mm);
2194
2195out_mmput:
2196	mmput(mm);
2197out:
2198	return rc;
2199}
2200
2201struct map_files_info {
2202	unsigned long	start;
2203	unsigned long	end;
2204	fmode_t		mode;
2205};
2206
2207/*
2208 * Only allow CAP_SYS_ADMIN and CAP_CHECKPOINT_RESTORE to follow the links, due
2209 * to concerns about how the symlinks may be used to bypass permissions on
2210 * ancestor directories in the path to the file in question.
2211 */
2212static const char *
2213proc_map_files_get_link(struct dentry *dentry,
2214			struct inode *inode,
2215		        struct delayed_call *done)
2216{
2217	if (!checkpoint_restore_ns_capable(&init_user_ns))
2218		return ERR_PTR(-EPERM);
2219
2220	return proc_pid_get_link(dentry, inode, done);
2221}
2222
2223/*
2224 * Identical to proc_pid_link_inode_operations except for get_link()
2225 */
2226static const struct inode_operations proc_map_files_link_inode_operations = {
2227	.readlink	= proc_pid_readlink,
2228	.get_link	= proc_map_files_get_link,
2229	.setattr	= proc_setattr,
2230};
2231
2232static struct dentry *
2233proc_map_files_instantiate(struct dentry *dentry,
2234			   struct task_struct *task, const void *ptr)
2235{
2236	fmode_t mode = (fmode_t)(unsigned long)ptr;
2237	struct proc_inode *ei;
2238	struct inode *inode;
2239
2240	inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
2241				    ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2242				    ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2243	if (!inode)
2244		return ERR_PTR(-ENOENT);
2245
2246	ei = PROC_I(inode);
2247	ei->op.proc_get_link = map_files_get_link;
2248
2249	inode->i_op = &proc_map_files_link_inode_operations;
2250	inode->i_size = 64;
2251
2252	d_set_d_op(dentry, &tid_map_files_dentry_operations);
2253	return d_splice_alias(inode, dentry);
2254}
2255
2256static struct dentry *proc_map_files_lookup(struct inode *dir,
2257		struct dentry *dentry, unsigned int flags)
2258{
2259	unsigned long vm_start, vm_end;
2260	struct vm_area_struct *vma;
2261	struct task_struct *task;
2262	struct dentry *result;
2263	struct mm_struct *mm;
2264
2265	result = ERR_PTR(-ENOENT);
2266	task = get_proc_task(dir);
2267	if (!task)
2268		goto out;
2269
2270	result = ERR_PTR(-EACCES);
2271	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2272		goto out_put_task;
2273
2274	result = ERR_PTR(-ENOENT);
2275	if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2276		goto out_put_task;
2277
2278	mm = get_task_mm(task);
2279	if (!mm)
2280		goto out_put_task;
2281
2282	result = ERR_PTR(-EINTR);
2283	if (mmap_read_lock_killable(mm))
2284		goto out_put_mm;
2285
2286	result = ERR_PTR(-ENOENT);
2287	vma = find_exact_vma(mm, vm_start, vm_end);
2288	if (!vma)
2289		goto out_no_vma;
2290
2291	if (vma->vm_file)
2292		result = proc_map_files_instantiate(dentry, task,
2293				(void *)(unsigned long)vma->vm_file->f_mode);
2294
2295out_no_vma:
2296	mmap_read_unlock(mm);
2297out_put_mm:
2298	mmput(mm);
2299out_put_task:
2300	put_task_struct(task);
2301out:
2302	return result;
2303}
2304
2305static const struct inode_operations proc_map_files_inode_operations = {
2306	.lookup		= proc_map_files_lookup,
2307	.permission	= proc_fd_permission,
2308	.setattr	= proc_setattr,
2309};
2310
2311static int
2312proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2313{
2314	struct vm_area_struct *vma;
2315	struct task_struct *task;
2316	struct mm_struct *mm;
2317	unsigned long nr_files, pos, i;
2318	GENRADIX(struct map_files_info) fa;
2319	struct map_files_info *p;
2320	int ret;
2321
2322	genradix_init(&fa);
2323
2324	ret = -ENOENT;
2325	task = get_proc_task(file_inode(file));
2326	if (!task)
2327		goto out;
2328
2329	ret = -EACCES;
2330	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2331		goto out_put_task;
2332
2333	ret = 0;
2334	if (!dir_emit_dots(file, ctx))
2335		goto out_put_task;
2336
2337	mm = get_task_mm(task);
2338	if (!mm)
2339		goto out_put_task;
2340
2341	ret = mmap_read_lock_killable(mm);
2342	if (ret) {
2343		mmput(mm);
2344		goto out_put_task;
2345	}
2346
2347	nr_files = 0;
2348
2349	/*
2350	 * We need two passes here:
2351	 *
2352	 *  1) Collect vmas of mapped files with mmap_lock taken
2353	 *  2) Release mmap_lock and instantiate entries
2354	 *
2355	 * otherwise we get lockdep complained, since filldir()
2356	 * routine might require mmap_lock taken in might_fault().
2357	 */
2358
2359	for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2360		if (!vma->vm_file)
2361			continue;
2362		if (++pos <= ctx->pos)
2363			continue;
2364
2365		p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
2366		if (!p) {
2367			ret = -ENOMEM;
2368			mmap_read_unlock(mm);
2369			mmput(mm);
2370			goto out_put_task;
2371		}
2372
2373		p->start = vma->vm_start;
2374		p->end = vma->vm_end;
2375		p->mode = vma->vm_file->f_mode;
2376	}
2377	mmap_read_unlock(mm);
2378	mmput(mm);
2379
2380	for (i = 0; i < nr_files; i++) {
2381		char buf[4 * sizeof(long) + 2];	/* max: %lx-%lx\0 */
2382		unsigned int len;
2383
2384		p = genradix_ptr(&fa, i);
2385		len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2386		if (!proc_fill_cache(file, ctx,
2387				      buf, len,
2388				      proc_map_files_instantiate,
2389				      task,
2390				      (void *)(unsigned long)p->mode))
2391			break;
2392		ctx->pos++;
2393	}
2394
2395out_put_task:
2396	put_task_struct(task);
2397out:
2398	genradix_free(&fa);
2399	return ret;
2400}
2401
2402static const struct file_operations proc_map_files_operations = {
2403	.read		= generic_read_dir,
2404	.iterate_shared	= proc_map_files_readdir,
2405	.llseek		= generic_file_llseek,
2406};
2407
2408#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2409struct timers_private {
2410	struct pid *pid;
2411	struct task_struct *task;
2412	struct sighand_struct *sighand;
2413	struct pid_namespace *ns;
2414	unsigned long flags;
2415};
2416
2417static void *timers_start(struct seq_file *m, loff_t *pos)
2418{
2419	struct timers_private *tp = m->private;
2420
2421	tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2422	if (!tp->task)
2423		return ERR_PTR(-ESRCH);
2424
2425	tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2426	if (!tp->sighand)
2427		return ERR_PTR(-ESRCH);
2428
2429	return seq_list_start(&tp->task->signal->posix_timers, *pos);
2430}
2431
2432static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2433{
2434	struct timers_private *tp = m->private;
2435	return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2436}
2437
2438static void timers_stop(struct seq_file *m, void *v)
2439{
2440	struct timers_private *tp = m->private;
2441
2442	if (tp->sighand) {
2443		unlock_task_sighand(tp->task, &tp->flags);
2444		tp->sighand = NULL;
2445	}
2446
2447	if (tp->task) {
2448		put_task_struct(tp->task);
2449		tp->task = NULL;
2450	}
2451}
2452
2453static int show_timer(struct seq_file *m, void *v)
2454{
2455	struct k_itimer *timer;
2456	struct timers_private *tp = m->private;
2457	int notify;
2458	static const char * const nstr[] = {
2459		[SIGEV_SIGNAL] = "signal",
2460		[SIGEV_NONE] = "none",
2461		[SIGEV_THREAD] = "thread",
2462	};
2463
2464	timer = list_entry((struct list_head *)v, struct k_itimer, list);
2465	notify = timer->it_sigev_notify;
2466
2467	seq_printf(m, "ID: %d\n", timer->it_id);
2468	seq_printf(m, "signal: %d/%px\n",
2469		   timer->sigq->info.si_signo,
2470		   timer->sigq->info.si_value.sival_ptr);
2471	seq_printf(m, "notify: %s/%s.%d\n",
2472		   nstr[notify & ~SIGEV_THREAD_ID],
2473		   (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2474		   pid_nr_ns(timer->it_pid, tp->ns));
2475	seq_printf(m, "ClockID: %d\n", timer->it_clock);
2476
2477	return 0;
2478}
2479
2480static const struct seq_operations proc_timers_seq_ops = {
2481	.start	= timers_start,
2482	.next	= timers_next,
2483	.stop	= timers_stop,
2484	.show	= show_timer,
2485};
2486
2487static int proc_timers_open(struct inode *inode, struct file *file)
2488{
2489	struct timers_private *tp;
2490
2491	tp = __seq_open_private(file, &proc_timers_seq_ops,
2492			sizeof(struct timers_private));
2493	if (!tp)
2494		return -ENOMEM;
2495
2496	tp->pid = proc_pid(inode);
2497	tp->ns = proc_pid_ns(inode->i_sb);
2498	return 0;
2499}
2500
2501static const struct file_operations proc_timers_operations = {
2502	.open		= proc_timers_open,
2503	.read		= seq_read,
2504	.llseek		= seq_lseek,
2505	.release	= seq_release_private,
2506};
2507#endif
2508
2509static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2510					size_t count, loff_t *offset)
2511{
2512	struct inode *inode = file_inode(file);
2513	struct task_struct *p;
2514	u64 slack_ns;
2515	int err;
2516
2517	err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2518	if (err < 0)
2519		return err;
2520
2521	p = get_proc_task(inode);
2522	if (!p)
2523		return -ESRCH;
2524
2525	if (p != current) {
2526		rcu_read_lock();
2527		if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2528			rcu_read_unlock();
2529			count = -EPERM;
2530			goto out;
2531		}
2532		rcu_read_unlock();
2533
2534		err = security_task_setscheduler(p);
2535		if (err) {
2536			count = err;
2537			goto out;
2538		}
2539	}
2540
2541	task_lock(p);
2542	if (slack_ns == 0)
2543		p->timer_slack_ns = p->default_timer_slack_ns;
2544	else
2545		p->timer_slack_ns = slack_ns;
2546	task_unlock(p);
2547
2548out:
2549	put_task_struct(p);
2550
2551	return count;
2552}
2553
2554static int timerslack_ns_show(struct seq_file *m, void *v)
2555{
2556	struct inode *inode = m->private;
2557	struct task_struct *p;
2558	int err = 0;
2559
2560	p = get_proc_task(inode);
2561	if (!p)
2562		return -ESRCH;
2563
2564	if (p != current) {
2565		rcu_read_lock();
2566		if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2567			rcu_read_unlock();
2568			err = -EPERM;
2569			goto out;
2570		}
2571		rcu_read_unlock();
2572
2573		err = security_task_getscheduler(p);
2574		if (err)
2575			goto out;
2576	}
2577
2578	task_lock(p);
2579	seq_printf(m, "%llu\n", p->timer_slack_ns);
2580	task_unlock(p);
2581
2582out:
2583	put_task_struct(p);
2584
2585	return err;
2586}
2587
2588static int timerslack_ns_open(struct inode *inode, struct file *filp)
2589{
2590	return single_open(filp, timerslack_ns_show, inode);
2591}
2592
2593static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2594	.open		= timerslack_ns_open,
2595	.read		= seq_read,
2596	.write		= timerslack_ns_write,
2597	.llseek		= seq_lseek,
2598	.release	= single_release,
2599};
2600
2601static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2602	struct task_struct *task, const void *ptr)
2603{
2604	const struct pid_entry *p = ptr;
2605	struct inode *inode;
2606	struct proc_inode *ei;
2607
2608	inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
2609	if (!inode)
2610		return ERR_PTR(-ENOENT);
2611
2612	ei = PROC_I(inode);
2613	if (S_ISDIR(inode->i_mode))
2614		set_nlink(inode, 2);	/* Use getattr to fix if necessary */
2615	if (p->iop)
2616		inode->i_op = p->iop;
2617	if (p->fop)
2618		inode->i_fop = p->fop;
2619	ei->op = p->op;
2620	pid_update_inode(task, inode);
2621	d_set_d_op(dentry, &pid_dentry_operations);
2622	return d_splice_alias(inode, dentry);
2623}
2624
2625static struct dentry *proc_pident_lookup(struct inode *dir,
2626					 struct dentry *dentry,
2627					 const struct pid_entry *p,
2628					 const struct pid_entry *end)
2629{
2630	struct task_struct *task = get_proc_task(dir);
2631	struct dentry *res = ERR_PTR(-ENOENT);
2632
2633	if (!task)
2634		goto out_no_task;
2635
2636	/*
2637	 * Yes, it does not scale. And it should not. Don't add
2638	 * new entries into /proc/<tgid>/ without very good reasons.
2639	 */
2640	for (; p < end; p++) {
2641		if (p->len != dentry->d_name.len)
2642			continue;
2643		if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2644			res = proc_pident_instantiate(dentry, task, p);
2645			break;
2646		}
2647	}
2648	put_task_struct(task);
2649out_no_task:
2650	return res;
2651}
2652
2653static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2654		const struct pid_entry *ents, unsigned int nents)
2655{
2656	struct task_struct *task = get_proc_task(file_inode(file));
2657	const struct pid_entry *p;
2658
2659	if (!task)
2660		return -ENOENT;
2661
2662	if (!dir_emit_dots(file, ctx))
2663		goto out;
2664
2665	if (ctx->pos >= nents + 2)
2666		goto out;
2667
2668	for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2669		if (!proc_fill_cache(file, ctx, p->name, p->len,
2670				proc_pident_instantiate, task, p))
2671			break;
2672		ctx->pos++;
2673	}
2674out:
2675	put_task_struct(task);
2676	return 0;
2677}
2678
2679#ifdef CONFIG_SECURITY
2680static int proc_pid_attr_open(struct inode *inode, struct file *file)
2681{
2682	file->private_data = NULL;
2683	__mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
2684	return 0;
2685}
2686
2687static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2688				  size_t count, loff_t *ppos)
2689{
2690	struct inode * inode = file_inode(file);
2691	char *p = NULL;
2692	ssize_t length;
2693	struct task_struct *task = get_proc_task(inode);
2694
2695	if (!task)
2696		return -ESRCH;
2697
2698	length = security_getprocattr(task, PROC_I(inode)->op.lsm,
2699				      (char*)file->f_path.dentry->d_name.name,
2700				      &p);
2701	put_task_struct(task);
2702	if (length > 0)
2703		length = simple_read_from_buffer(buf, count, ppos, p, length);
2704	kfree(p);
2705	return length;
2706}
2707
2708static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2709				   size_t count, loff_t *ppos)
2710{
2711	struct inode * inode = file_inode(file);
2712	struct task_struct *task;
2713	void *page;
2714	int rv;
2715
2716	/* A task may only write when it was the opener. */
2717	if (file->private_data != current->mm)
2718		return -EPERM;
2719
2720	rcu_read_lock();
2721	task = pid_task(proc_pid(inode), PIDTYPE_PID);
2722	if (!task) {
2723		rcu_read_unlock();
2724		return -ESRCH;
2725	}
2726	/* A task may only write its own attributes. */
2727	if (current != task) {
2728		rcu_read_unlock();
2729		return -EACCES;
2730	}
2731	/* Prevent changes to overridden credentials. */
2732	if (current_cred() != current_real_cred()) {
2733		rcu_read_unlock();
2734		return -EBUSY;
2735	}
2736	rcu_read_unlock();
2737
2738	if (count > PAGE_SIZE)
2739		count = PAGE_SIZE;
2740
2741	/* No partial writes. */
2742	if (*ppos != 0)
2743		return -EINVAL;
2744
2745	page = memdup_user(buf, count);
2746	if (IS_ERR(page)) {
2747		rv = PTR_ERR(page);
2748		goto out;
2749	}
2750
2751	/* Guard against adverse ptrace interaction */
2752	rv = mutex_lock_interruptible(&current->signal->cred_guard_mutex);
2753	if (rv < 0)
2754		goto out_free;
2755
2756	rv = security_setprocattr(PROC_I(inode)->op.lsm,
2757				  file->f_path.dentry->d_name.name, page,
2758				  count);
2759	mutex_unlock(&current->signal->cred_guard_mutex);
2760out_free:
2761	kfree(page);
2762out:
2763	return rv;
2764}
2765
2766static const struct file_operations proc_pid_attr_operations = {
2767	.open		= proc_pid_attr_open,
2768	.read		= proc_pid_attr_read,
2769	.write		= proc_pid_attr_write,
2770	.llseek		= generic_file_llseek,
2771	.release	= mem_release,
2772};
2773
2774#define LSM_DIR_OPS(LSM) \
2775static int proc_##LSM##_attr_dir_iterate(struct file *filp, \
2776			     struct dir_context *ctx) \
2777{ \
2778	return proc_pident_readdir(filp, ctx, \
2779				   LSM##_attr_dir_stuff, \
2780				   ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2781} \
2782\
2783static const struct file_operations proc_##LSM##_attr_dir_ops = { \
2784	.read		= generic_read_dir, \
2785	.iterate	= proc_##LSM##_attr_dir_iterate, \
2786	.llseek		= default_llseek, \
2787}; \
2788\
2789static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
2790				struct dentry *dentry, unsigned int flags) \
2791{ \
2792	return proc_pident_lookup(dir, dentry, \
2793				  LSM##_attr_dir_stuff, \
2794				  LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2795} \
2796\
2797static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
2798	.lookup		= proc_##LSM##_attr_dir_lookup, \
2799	.getattr	= pid_getattr, \
2800	.setattr	= proc_setattr, \
2801}
2802
2803#ifdef CONFIG_SECURITY_SMACK
2804static const struct pid_entry smack_attr_dir_stuff[] = {
2805	ATTR("smack", "current",	0666),
2806};
2807LSM_DIR_OPS(smack);
2808#endif
2809
2810#ifdef CONFIG_SECURITY_APPARMOR
2811static const struct pid_entry apparmor_attr_dir_stuff[] = {
2812	ATTR("apparmor", "current",	0666),
2813	ATTR("apparmor", "prev",	0444),
2814	ATTR("apparmor", "exec",	0666),
2815};
2816LSM_DIR_OPS(apparmor);
2817#endif
2818
2819static const struct pid_entry attr_dir_stuff[] = {
2820	ATTR(NULL, "current",		0666),
2821	ATTR(NULL, "prev",		0444),
2822	ATTR(NULL, "exec",		0666),
2823	ATTR(NULL, "fscreate",		0666),
2824	ATTR(NULL, "keycreate",		0666),
2825	ATTR(NULL, "sockcreate",	0666),
2826#ifdef CONFIG_SECURITY_SMACK
2827	DIR("smack",			0555,
2828	    proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
2829#endif
2830#ifdef CONFIG_SECURITY_APPARMOR
2831	DIR("apparmor",			0555,
2832	    proc_apparmor_attr_dir_inode_ops, proc_apparmor_attr_dir_ops),
2833#endif
2834};
2835
2836static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2837{
2838	return proc_pident_readdir(file, ctx,
2839				   attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2840}
2841
2842static const struct file_operations proc_attr_dir_operations = {
2843	.read		= generic_read_dir,
2844	.iterate_shared	= proc_attr_dir_readdir,
2845	.llseek		= generic_file_llseek,
2846};
2847
2848static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2849				struct dentry *dentry, unsigned int flags)
2850{
2851	return proc_pident_lookup(dir, dentry,
2852				  attr_dir_stuff,
2853				  attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
2854}
2855
2856static const struct inode_operations proc_attr_dir_inode_operations = {
2857	.lookup		= proc_attr_dir_lookup,
2858	.getattr	= pid_getattr,
2859	.setattr	= proc_setattr,
2860};
2861
2862#endif
2863
2864#ifdef CONFIG_ELF_CORE
2865static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2866					 size_t count, loff_t *ppos)
2867{
2868	struct task_struct *task = get_proc_task(file_inode(file));
2869	struct mm_struct *mm;
2870	char buffer[PROC_NUMBUF];
2871	size_t len;
2872	int ret;
2873
2874	if (!task)
2875		return -ESRCH;
2876
2877	ret = 0;
2878	mm = get_task_mm(task);
2879	if (mm) {
2880		len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2881			       ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2882				MMF_DUMP_FILTER_SHIFT));
2883		mmput(mm);
2884		ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2885	}
2886
2887	put_task_struct(task);
2888
2889	return ret;
2890}
2891
2892static ssize_t proc_coredump_filter_write(struct file *file,
2893					  const char __user *buf,
2894					  size_t count,
2895					  loff_t *ppos)
2896{
2897	struct task_struct *task;
2898	struct mm_struct *mm;
2899	unsigned int val;
2900	int ret;
2901	int i;
2902	unsigned long mask;
2903
2904	ret = kstrtouint_from_user(buf, count, 0, &val);
2905	if (ret < 0)
2906		return ret;
2907
2908	ret = -ESRCH;
2909	task = get_proc_task(file_inode(file));
2910	if (!task)
2911		goto out_no_task;
2912
2913	mm = get_task_mm(task);
2914	if (!mm)
2915		goto out_no_mm;
2916	ret = 0;
2917
2918	for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2919		if (val & mask)
2920			set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2921		else
2922			clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2923	}
2924
2925	mmput(mm);
2926 out_no_mm:
2927	put_task_struct(task);
2928 out_no_task:
2929	if (ret < 0)
2930		return ret;
2931	return count;
2932}
2933
2934static const struct file_operations proc_coredump_filter_operations = {
2935	.read		= proc_coredump_filter_read,
2936	.write		= proc_coredump_filter_write,
2937	.llseek		= generic_file_llseek,
2938};
2939#endif
2940
2941#ifdef CONFIG_TASK_IO_ACCOUNTING
2942static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2943{
2944	struct task_io_accounting acct = task->ioac;
2945	unsigned long flags;
2946	int result;
2947
2948	result = down_read_killable(&task->signal->exec_update_lock);
2949	if (result)
2950		return result;
2951
2952	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2953		result = -EACCES;
2954		goto out_unlock;
2955	}
2956
2957	if (whole && lock_task_sighand(task, &flags)) {
2958		struct task_struct *t = task;
2959
2960		task_io_accounting_add(&acct, &task->signal->ioac);
2961		while_each_thread(task, t)
2962			task_io_accounting_add(&acct, &t->ioac);
2963
2964		unlock_task_sighand(task, &flags);
2965	}
2966	seq_printf(m,
2967		   "rchar: %llu\n"
2968		   "wchar: %llu\n"
2969		   "syscr: %llu\n"
2970		   "syscw: %llu\n"
2971		   "read_bytes: %llu\n"
2972		   "write_bytes: %llu\n"
2973		   "cancelled_write_bytes: %llu\n",
2974		   (unsigned long long)acct.rchar,
2975		   (unsigned long long)acct.wchar,
2976		   (unsigned long long)acct.syscr,
2977		   (unsigned long long)acct.syscw,
2978		   (unsigned long long)acct.read_bytes,
2979		   (unsigned long long)acct.write_bytes,
2980		   (unsigned long long)acct.cancelled_write_bytes);
2981	result = 0;
2982
2983out_unlock:
2984	up_read(&task->signal->exec_update_lock);
2985	return result;
2986}
2987
2988static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2989				  struct pid *pid, struct task_struct *task)
2990{
2991	return do_io_accounting(task, m, 0);
2992}
2993
2994static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2995				   struct pid *pid, struct task_struct *task)
2996{
2997	return do_io_accounting(task, m, 1);
2998}
2999#endif /* CONFIG_TASK_IO_ACCOUNTING */
3000
3001#ifdef CONFIG_USER_NS
3002static int proc_id_map_open(struct inode *inode, struct file *file,
3003	const struct seq_operations *seq_ops)
3004{
3005	struct user_namespace *ns = NULL;
3006	struct task_struct *task;
3007	struct seq_file *seq;
3008	int ret = -EINVAL;
3009
3010	task = get_proc_task(inode);
3011	if (task) {
3012		rcu_read_lock();
3013		ns = get_user_ns(task_cred_xxx(task, user_ns));
3014		rcu_read_unlock();
3015		put_task_struct(task);
3016	}
3017	if (!ns)
3018		goto err;
3019
3020	ret = seq_open(file, seq_ops);
3021	if (ret)
3022		goto err_put_ns;
3023
3024	seq = file->private_data;
3025	seq->private = ns;
3026
3027	return 0;
3028err_put_ns:
3029	put_user_ns(ns);
3030err:
3031	return ret;
3032}
3033
3034static int proc_id_map_release(struct inode *inode, struct file *file)
3035{
3036	struct seq_file *seq = file->private_data;
3037	struct user_namespace *ns = seq->private;
3038	put_user_ns(ns);
3039	return seq_release(inode, file);
3040}
3041
3042static int proc_uid_map_open(struct inode *inode, struct file *file)
3043{
3044	return proc_id_map_open(inode, file, &proc_uid_seq_operations);
3045}
3046
3047static int proc_gid_map_open(struct inode *inode, struct file *file)
3048{
3049	return proc_id_map_open(inode, file, &proc_gid_seq_operations);
3050}
3051
3052static int proc_projid_map_open(struct inode *inode, struct file *file)
3053{
3054	return proc_id_map_open(inode, file, &proc_projid_seq_operations);
3055}
3056
3057static const struct file_operations proc_uid_map_operations = {
3058	.open		= proc_uid_map_open,
3059	.write		= proc_uid_map_write,
3060	.read		= seq_read,
3061	.llseek		= seq_lseek,
3062	.release	= proc_id_map_release,
3063};
3064
3065static const struct file_operations proc_gid_map_operations = {
3066	.open		= proc_gid_map_open,
3067	.write		= proc_gid_map_write,
3068	.read		= seq_read,
3069	.llseek		= seq_lseek,
3070	.release	= proc_id_map_release,
3071};
3072
3073static const struct file_operations proc_projid_map_operations = {
3074	.open		= proc_projid_map_open,
3075	.write		= proc_projid_map_write,
3076	.read		= seq_read,
3077	.llseek		= seq_lseek,
3078	.release	= proc_id_map_release,
3079};
3080
3081static int proc_setgroups_open(struct inode *inode, struct file *file)
3082{
3083	struct user_namespace *ns = NULL;
3084	struct task_struct *task;
3085	int ret;
3086
3087	ret = -ESRCH;
3088	task = get_proc_task(inode);
3089	if (task) {
3090		rcu_read_lock();
3091		ns = get_user_ns(task_cred_xxx(task, user_ns));
3092		rcu_read_unlock();
3093		put_task_struct(task);
3094	}
3095	if (!ns)
3096		goto err;
3097
3098	if (file->f_mode & FMODE_WRITE) {
3099		ret = -EACCES;
3100		if (!ns_capable(ns, CAP_SYS_ADMIN))
3101			goto err_put_ns;
3102	}
3103
3104	ret = single_open(file, &proc_setgroups_show, ns);
3105	if (ret)
3106		goto err_put_ns;
3107
3108	return 0;
3109err_put_ns:
3110	put_user_ns(ns);
3111err:
3112	return ret;
3113}
3114
3115static int proc_setgroups_release(struct inode *inode, struct file *file)
3116{
3117	struct seq_file *seq = file->private_data;
3118	struct user_namespace *ns = seq->private;
3119	int ret = single_release(inode, file);
3120	put_user_ns(ns);
3121	return ret;
3122}
3123
3124static const struct file_operations proc_setgroups_operations = {
3125	.open		= proc_setgroups_open,
3126	.write		= proc_setgroups_write,
3127	.read		= seq_read,
3128	.llseek		= seq_lseek,
3129	.release	= proc_setgroups_release,
3130};
3131#endif /* CONFIG_USER_NS */
3132
3133static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
3134				struct pid *pid, struct task_struct *task)
3135{
3136	int err = lock_trace(task);
3137	if (!err) {
3138		seq_printf(m, "%08x\n", task->personality);
3139		unlock_trace(task);
3140	}
3141	return err;
3142}
3143
3144#ifdef CONFIG_LIVEPATCH
3145static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
3146				struct pid *pid, struct task_struct *task)
3147{
3148	seq_printf(m, "%d\n", task->patch_state);
3149	return 0;
3150}
3151#endif /* CONFIG_LIVEPATCH */
3152
3153#ifdef CONFIG_STACKLEAK_METRICS
3154static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
3155				struct pid *pid, struct task_struct *task)
3156{
3157	unsigned long prev_depth = THREAD_SIZE -
3158				(task->prev_lowest_stack & (THREAD_SIZE - 1));
3159	unsigned long depth = THREAD_SIZE -
3160				(task->lowest_stack & (THREAD_SIZE - 1));
3161
3162	seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
3163							prev_depth, depth);
3164	return 0;
3165}
3166#endif /* CONFIG_STACKLEAK_METRICS */
3167
3168/*
3169 * Thread groups
3170 */
3171static const struct file_operations proc_task_operations;
3172static const struct inode_operations proc_task_inode_operations;
3173
3174static const struct pid_entry tgid_base_stuff[] = {
3175	DIR("task",       S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3176	DIR("fd",         S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3177	DIR("map_files",  S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3178	DIR("fdinfo",     S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3179	DIR("ns",	  S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3180#ifdef CONFIG_NET
3181	DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3182#endif
3183	REG("environ",    S_IRUSR, proc_environ_operations),
3184	REG("auxv",       S_IRUSR, proc_auxv_operations),
3185	ONE("status",     S_IRUGO, proc_pid_status),
3186	ONE("personality", S_IRUSR, proc_pid_personality),
3187	ONE("limits",	  S_IRUGO, proc_pid_limits),
3188#ifdef CONFIG_SCHED_DEBUG
3189	REG("sched",      S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3190#endif
3191#ifdef CONFIG_SCHED_AUTOGROUP
3192	REG("autogroup",  S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3193#endif
3194#ifdef CONFIG_TIME_NS
3195	REG("timens_offsets",  S_IRUGO|S_IWUSR, proc_timens_offsets_operations),
3196#endif
3197	REG("comm",      S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3198#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3199	ONE("syscall",    S_IRUSR, proc_pid_syscall),
3200#endif
3201	REG("cmdline",    S_IRUGO, proc_pid_cmdline_ops),
3202	ONE("stat",       S_IRUGO, proc_tgid_stat),
3203	ONE("statm",      S_IRUGO, proc_pid_statm),
3204	REG("maps",       S_IRUGO, proc_pid_maps_operations),
3205#ifdef CONFIG_NUMA
3206	REG("numa_maps",  S_IRUGO, proc_pid_numa_maps_operations),
3207#endif
3208	REG("mem",        S_IRUSR|S_IWUSR, proc_mem_operations),
3209	LNK("cwd",        proc_cwd_link),
3210	LNK("root",       proc_root_link),
3211	LNK("exe",        proc_exe_link),
3212	REG("mounts",     S_IRUGO, proc_mounts_operations),
3213	REG("mountinfo",  S_IRUGO, proc_mountinfo_operations),
3214	REG("mountstats", S_IRUSR, proc_mountstats_operations),
3215#ifdef CONFIG_PROC_PAGE_MONITOR
3216	REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3217	REG("smaps",      S_IRUGO, proc_pid_smaps_operations),
3218	REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3219	REG("pagemap",    S_IRUSR, proc_pagemap_operations),
3220#endif
3221#ifdef CONFIG_SECURITY
3222	DIR("attr",       S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3223#endif
3224#ifdef CONFIG_KALLSYMS
3225	ONE("wchan",      S_IRUGO, proc_pid_wchan),
3226#endif
3227#ifdef CONFIG_STACKTRACE
3228	ONE("stack",      S_IRUSR, proc_pid_stack),
3229#endif
3230#ifdef CONFIG_SCHED_INFO
3231	ONE("schedstat",  S_IRUGO, proc_pid_schedstat),
3232#endif
3233#ifdef CONFIG_LATENCYTOP
3234	REG("latency",  S_IRUGO, proc_lstats_operations),
3235#endif
3236#ifdef CONFIG_PROC_PID_CPUSET
3237	ONE("cpuset",     S_IRUGO, proc_cpuset_show),
3238#endif
3239#ifdef CONFIG_CGROUPS
3240	ONE("cgroup",  S_IRUGO, proc_cgroup_show),
3241#endif
3242#ifdef CONFIG_PROC_CPU_RESCTRL
3243	ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3244#endif
3245	ONE("oom_score",  S_IRUGO, proc_oom_score),
3246	REG("oom_adj",    S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3247	REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3248#ifdef CONFIG_AUDIT
3249	REG("loginuid",   S_IWUSR|S_IRUGO, proc_loginuid_operations),
3250	REG("sessionid",  S_IRUGO, proc_sessionid_operations),
3251#endif
3252#ifdef CONFIG_FAULT_INJECTION
3253	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3254	REG("fail-nth", 0644, proc_fail_nth_operations),
3255#endif
3256#ifdef CONFIG_ELF_CORE
3257	REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3258#endif
3259#ifdef CONFIG_TASK_IO_ACCOUNTING
3260	ONE("io",	S_IRUSR, proc_tgid_io_accounting),
3261#endif
3262#ifdef CONFIG_USER_NS
3263	REG("uid_map",    S_IRUGO|S_IWUSR, proc_uid_map_operations),
3264	REG("gid_map",    S_IRUGO|S_IWUSR, proc_gid_map_operations),
3265	REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3266	REG("setgroups",  S_IRUGO|S_IWUSR, proc_setgroups_operations),
3267#endif
3268#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3269	REG("timers",	  S_IRUGO, proc_timers_operations),
3270#endif
3271	REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3272#ifdef CONFIG_LIVEPATCH
3273	ONE("patch_state",  S_IRUSR, proc_pid_patch_state),
3274#endif
3275#ifdef CONFIG_STACKLEAK_METRICS
3276	ONE("stack_depth", S_IRUGO, proc_stack_depth),
3277#endif
3278#ifdef CONFIG_PROC_PID_ARCH_STATUS
3279	ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3280#endif
3281#ifdef CONFIG_SECCOMP_CACHE_DEBUG
3282	ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3283#endif
3284};
3285
3286static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3287{
3288	return proc_pident_readdir(file, ctx,
3289				   tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3290}
3291
3292static const struct file_operations proc_tgid_base_operations = {
3293	.read		= generic_read_dir,
3294	.iterate_shared	= proc_tgid_base_readdir,
3295	.llseek		= generic_file_llseek,
3296};
3297
3298struct pid *tgid_pidfd_to_pid(const struct file *file)
3299{
3300	if (file->f_op != &proc_tgid_base_operations)
3301		return ERR_PTR(-EBADF);
3302
3303	return proc_pid(file_inode(file));
3304}
3305
3306static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3307{
3308	return proc_pident_lookup(dir, dentry,
3309				  tgid_base_stuff,
3310				  tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
3311}
3312
3313static const struct inode_operations proc_tgid_base_inode_operations = {
3314	.lookup		= proc_tgid_base_lookup,
3315	.getattr	= pid_getattr,
3316	.setattr	= proc_setattr,
3317	.permission	= proc_pid_permission,
3318};
3319
3320/**
3321 * proc_flush_pid -  Remove dcache entries for @pid from the /proc dcache.
3322 * @pid: pid that should be flushed.
3323 *
3324 * This function walks a list of inodes (that belong to any proc
3325 * filesystem) that are attached to the pid and flushes them from
3326 * the dentry cache.
3327 *
3328 * It is safe and reasonable to cache /proc entries for a task until
3329 * that task exits.  After that they just clog up the dcache with
3330 * useless entries, possibly causing useful dcache entries to be
3331 * flushed instead.  This routine is provided to flush those useless
3332 * dcache entries when a process is reaped.
3333 *
3334 * NOTE: This routine is just an optimization so it does not guarantee
3335 *       that no dcache entries will exist after a process is reaped
3336 *       it just makes it very unlikely that any will persist.
3337 */
3338
3339void proc_flush_pid(struct pid *pid)
3340{
3341	proc_invalidate_siblings_dcache(&pid->inodes, &pid->lock);
3342}
3343
3344static struct dentry *proc_pid_instantiate(struct dentry * dentry,
3345				   struct task_struct *task, const void *ptr)
3346{
3347	struct inode *inode;
3348
3349	inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3350	if (!inode)
3351		return ERR_PTR(-ENOENT);
3352
3353	inode->i_op = &proc_tgid_base_inode_operations;
3354	inode->i_fop = &proc_tgid_base_operations;
3355	inode->i_flags|=S_IMMUTABLE;
3356
3357	set_nlink(inode, nlink_tgid);
3358	pid_update_inode(task, inode);
3359
3360	d_set_d_op(dentry, &pid_dentry_operations);
3361	return d_splice_alias(inode, dentry);
3362}
3363
3364struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
3365{
3366	struct task_struct *task;
3367	unsigned tgid;
3368	struct proc_fs_info *fs_info;
3369	struct pid_namespace *ns;
3370	struct dentry *result = ERR_PTR(-ENOENT);
3371
3372	tgid = name_to_int(&dentry->d_name);
3373	if (tgid == ~0U)
3374		goto out;
3375
3376	fs_info = proc_sb_info(dentry->d_sb);
3377	ns = fs_info->pid_ns;
3378	rcu_read_lock();
3379	task = find_task_by_pid_ns(tgid, ns);
3380	if (task)
3381		get_task_struct(task);
3382	rcu_read_unlock();
3383	if (!task)
3384		goto out;
3385
3386	/* Limit procfs to only ptraceable tasks */
3387	if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE) {
3388		if (!has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS))
3389			goto out_put_task;
3390	}
3391
3392	result = proc_pid_instantiate(dentry, task, NULL);
3393out_put_task:
3394	put_task_struct(task);
3395out:
3396	return result;
3397}
3398
3399/*
3400 * Find the first task with tgid >= tgid
3401 *
3402 */
3403struct tgid_iter {
3404	unsigned int tgid;
3405	struct task_struct *task;
3406};
3407static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3408{
3409	struct pid *pid;
3410
3411	if (iter.task)
3412		put_task_struct(iter.task);
3413	rcu_read_lock();
3414retry:
3415	iter.task = NULL;
3416	pid = find_ge_pid(iter.tgid, ns);
3417	if (pid) {
3418		iter.tgid = pid_nr_ns(pid, ns);
3419		iter.task = pid_task(pid, PIDTYPE_TGID);
3420		if (!iter.task) {
3421			iter.tgid += 1;
3422			goto retry;
3423		}
3424		get_task_struct(iter.task);
3425	}
3426	rcu_read_unlock();
3427	return iter;
3428}
3429
3430#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3431
3432/* for the /proc/ directory itself, after non-process stuff has been done */
3433int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3434{
3435	struct tgid_iter iter;
3436	struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb);
3437	struct pid_namespace *ns = proc_pid_ns(file_inode(file)->i_sb);
3438	loff_t pos = ctx->pos;
3439
3440	if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3441		return 0;
3442
3443	if (pos == TGID_OFFSET - 2) {
3444		struct inode *inode = d_inode(fs_info->proc_self);
3445		if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3446			return 0;
3447		ctx->pos = pos = pos + 1;
3448	}
3449	if (pos == TGID_OFFSET - 1) {
3450		struct inode *inode = d_inode(fs_info->proc_thread_self);
3451		if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3452			return 0;
3453		ctx->pos = pos = pos + 1;
3454	}
3455	iter.tgid = pos - TGID_OFFSET;
3456	iter.task = NULL;
3457	for (iter = next_tgid(ns, iter);
3458	     iter.task;
3459	     iter.tgid += 1, iter = next_tgid(ns, iter)) {
3460		char name[10 + 1];
3461		unsigned int len;
3462
3463		cond_resched();
3464		if (!has_pid_permissions(fs_info, iter.task, HIDEPID_INVISIBLE))
3465			continue;
3466
3467		len = snprintf(name, sizeof(name), "%u", iter.tgid);
3468		ctx->pos = iter.tgid + TGID_OFFSET;
3469		if (!proc_fill_cache(file, ctx, name, len,
3470				     proc_pid_instantiate, iter.task, NULL)) {
3471			put_task_struct(iter.task);
3472			return 0;
3473		}
3474	}
3475	ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3476	return 0;
3477}
3478
3479/*
3480 * proc_tid_comm_permission is a special permission function exclusively
3481 * used for the node /proc/<pid>/task/<tid>/comm.
3482 * It bypasses generic permission checks in the case where a task of the same
3483 * task group attempts to access the node.
3484 * The rationale behind this is that glibc and bionic access this node for
3485 * cross thread naming (pthread_set/getname_np(!self)). However, if
3486 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3487 * which locks out the cross thread naming implementation.
3488 * This function makes sure that the node is always accessible for members of
3489 * same thread group.
3490 */
3491static int proc_tid_comm_permission(struct user_namespace *mnt_userns,
3492				    struct inode *inode, int mask)
3493{
3494	bool is_same_tgroup;
3495	struct task_struct *task;
3496
3497	task = get_proc_task(inode);
3498	if (!task)
3499		return -ESRCH;
3500	is_same_tgroup = same_thread_group(current, task);
3501	put_task_struct(task);
3502
3503	if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3504		/* This file (/proc/<pid>/task/<tid>/comm) can always be
3505		 * read or written by the members of the corresponding
3506		 * thread group.
3507		 */
3508		return 0;
3509	}
3510
3511	return generic_permission(&init_user_ns, inode, mask);
3512}
3513
3514static const struct inode_operations proc_tid_comm_inode_operations = {
3515		.permission = proc_tid_comm_permission,
3516};
3517
3518/*
3519 * Tasks
3520 */
3521static const struct pid_entry tid_base_stuff[] = {
3522	DIR("fd",        S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3523	DIR("fdinfo",    S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3524	DIR("ns",	 S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3525#ifdef CONFIG_NET
3526	DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3527#endif
3528	REG("environ",   S_IRUSR, proc_environ_operations),
3529	REG("auxv",      S_IRUSR, proc_auxv_operations),
3530	ONE("status",    S_IRUGO, proc_pid_status),
3531	ONE("personality", S_IRUSR, proc_pid_personality),
3532	ONE("limits",	 S_IRUGO, proc_pid_limits),
3533#ifdef CONFIG_SCHED_DEBUG
3534	REG("sched",     S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3535#endif
3536	NOD("comm",      S_IFREG|S_IRUGO|S_IWUSR,
3537			 &proc_tid_comm_inode_operations,
3538			 &proc_pid_set_comm_operations, {}),
3539#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3540	ONE("syscall",   S_IRUSR, proc_pid_syscall),
3541#endif
3542	REG("cmdline",   S_IRUGO, proc_pid_cmdline_ops),
3543	ONE("stat",      S_IRUGO, proc_tid_stat),
3544	ONE("statm",     S_IRUGO, proc_pid_statm),
3545	REG("maps",      S_IRUGO, proc_pid_maps_operations),
3546#ifdef CONFIG_PROC_CHILDREN
3547	REG("children",  S_IRUGO, proc_tid_children_operations),
3548#endif
3549#ifdef CONFIG_NUMA
3550	REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3551#endif
3552	REG("mem",       S_IRUSR|S_IWUSR, proc_mem_operations),
3553	LNK("cwd",       proc_cwd_link),
3554	LNK("root",      proc_root_link),
3555	LNK("exe",       proc_exe_link),
3556	REG("mounts",    S_IRUGO, proc_mounts_operations),
3557	REG("mountinfo",  S_IRUGO, proc_mountinfo_operations),
3558#ifdef CONFIG_PROC_PAGE_MONITOR
3559	REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3560	REG("smaps",     S_IRUGO, proc_pid_smaps_operations),
3561	REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3562	REG("pagemap",    S_IRUSR, proc_pagemap_operations),
3563#endif
3564#ifdef CONFIG_SECURITY
3565	DIR("attr",      S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3566#endif
3567#ifdef CONFIG_KALLSYMS
3568	ONE("wchan",     S_IRUGO, proc_pid_wchan),
3569#endif
3570#ifdef CONFIG_STACKTRACE
3571	ONE("stack",      S_IRUSR, proc_pid_stack),
3572#endif
3573#ifdef CONFIG_SCHED_INFO
3574	ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3575#endif
3576#ifdef CONFIG_LATENCYTOP
3577	REG("latency",  S_IRUGO, proc_lstats_operations),
3578#endif
3579#ifdef CONFIG_PROC_PID_CPUSET
3580	ONE("cpuset",    S_IRUGO, proc_cpuset_show),
3581#endif
3582#ifdef CONFIG_CGROUPS
3583	ONE("cgroup",  S_IRUGO, proc_cgroup_show),
3584#endif
3585#ifdef CONFIG_PROC_CPU_RESCTRL
3586	ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3587#endif
3588	ONE("oom_score", S_IRUGO, proc_oom_score),
3589	REG("oom_adj",   S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3590	REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3591#ifdef CONFIG_AUDIT
3592	REG("loginuid",  S_IWUSR|S_IRUGO, proc_loginuid_operations),
3593	REG("sessionid",  S_IRUGO, proc_sessionid_operations),
3594#endif
3595#ifdef CONFIG_FAULT_INJECTION
3596	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3597	REG("fail-nth", 0644, proc_fail_nth_operations),
3598#endif
3599#ifdef CONFIG_TASK_IO_ACCOUNTING
3600	ONE("io",	S_IRUSR, proc_tid_io_accounting),
3601#endif
3602#ifdef CONFIG_USER_NS
3603	REG("uid_map",    S_IRUGO|S_IWUSR, proc_uid_map_operations),
3604	REG("gid_map",    S_IRUGO|S_IWUSR, proc_gid_map_operations),
3605	REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3606	REG("setgroups",  S_IRUGO|S_IWUSR, proc_setgroups_operations),
3607#endif
3608#ifdef CONFIG_LIVEPATCH
3609	ONE("patch_state",  S_IRUSR, proc_pid_patch_state),
3610#endif
3611#ifdef CONFIG_PROC_PID_ARCH_STATUS
3612	ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3613#endif
3614#ifdef CONFIG_SECCOMP_CACHE_DEBUG
3615	ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3616#endif
3617};
3618
3619static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3620{
3621	return proc_pident_readdir(file, ctx,
3622				   tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3623}
3624
3625static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3626{
3627	return proc_pident_lookup(dir, dentry,
3628				  tid_base_stuff,
3629				  tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
3630}
3631
3632static const struct file_operations proc_tid_base_operations = {
3633	.read		= generic_read_dir,
3634	.iterate_shared	= proc_tid_base_readdir,
3635	.llseek		= generic_file_llseek,
3636};
3637
3638static const struct inode_operations proc_tid_base_inode_operations = {
3639	.lookup		= proc_tid_base_lookup,
3640	.getattr	= pid_getattr,
3641	.setattr	= proc_setattr,
3642};
3643
3644static struct dentry *proc_task_instantiate(struct dentry *dentry,
3645	struct task_struct *task, const void *ptr)
3646{
3647	struct inode *inode;
3648	inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3649	if (!inode)
3650		return ERR_PTR(-ENOENT);
3651
3652	inode->i_op = &proc_tid_base_inode_operations;
3653	inode->i_fop = &proc_tid_base_operations;
3654	inode->i_flags |= S_IMMUTABLE;
3655
3656	set_nlink(inode, nlink_tid);
3657	pid_update_inode(task, inode);
3658
3659	d_set_d_op(dentry, &pid_dentry_operations);
3660	return d_splice_alias(inode, dentry);
3661}
3662
3663static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3664{
3665	struct task_struct *task;
3666	struct task_struct *leader = get_proc_task(dir);
3667	unsigned tid;
3668	struct proc_fs_info *fs_info;
3669	struct pid_namespace *ns;
3670	struct dentry *result = ERR_PTR(-ENOENT);
3671
3672	if (!leader)
3673		goto out_no_task;
3674
3675	tid = name_to_int(&dentry->d_name);
3676	if (tid == ~0U)
3677		goto out;
3678
3679	fs_info = proc_sb_info(dentry->d_sb);
3680	ns = fs_info->pid_ns;
3681	rcu_read_lock();
3682	task = find_task_by_pid_ns(tid, ns);
3683	if (task)
3684		get_task_struct(task);
3685	rcu_read_unlock();
3686	if (!task)
3687		goto out;
3688	if (!same_thread_group(leader, task))
3689		goto out_drop_task;
3690
3691	result = proc_task_instantiate(dentry, task, NULL);
3692out_drop_task:
3693	put_task_struct(task);
3694out:
3695	put_task_struct(leader);
3696out_no_task:
3697	return result;
3698}
3699
3700/*
3701 * Find the first tid of a thread group to return to user space.
3702 *
3703 * Usually this is just the thread group leader, but if the users
3704 * buffer was too small or there was a seek into the middle of the
3705 * directory we have more work todo.
3706 *
3707 * In the case of a short read we start with find_task_by_pid.
3708 *
3709 * In the case of a seek we start with the leader and walk nr
3710 * threads past it.
3711 */
3712static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3713					struct pid_namespace *ns)
3714{
3715	struct task_struct *pos, *task;
3716	unsigned long nr = f_pos;
3717
3718	if (nr != f_pos)	/* 32bit overflow? */
3719		return NULL;
3720
3721	rcu_read_lock();
3722	task = pid_task(pid, PIDTYPE_PID);
3723	if (!task)
3724		goto fail;
3725
3726	/* Attempt to start with the tid of a thread */
3727	if (tid && nr) {
3728		pos = find_task_by_pid_ns(tid, ns);
3729		if (pos && same_thread_group(pos, task))
3730			goto found;
3731	}
3732
3733	/* If nr exceeds the number of threads there is nothing todo */
3734	if (nr >= get_nr_threads(task))
3735		goto fail;
3736
3737	/* If we haven't found our starting place yet start
3738	 * with the leader and walk nr threads forward.
3739	 */
3740	pos = task = task->group_leader;
3741	do {
3742		if (!nr--)
3743			goto found;
3744	} while_each_thread(task, pos);
3745fail:
3746	pos = NULL;
3747	goto out;
3748found:
3749	get_task_struct(pos);
3750out:
3751	rcu_read_unlock();
3752	return pos;
3753}
3754
3755/*
3756 * Find the next thread in the thread list.
3757 * Return NULL if there is an error or no next thread.
3758 *
3759 * The reference to the input task_struct is released.
3760 */
3761static struct task_struct *next_tid(struct task_struct *start)
3762{
3763	struct task_struct *pos = NULL;
3764	rcu_read_lock();
3765	if (pid_alive(start)) {
3766		pos = next_thread(start);
3767		if (thread_group_leader(pos))
3768			pos = NULL;
3769		else
3770			get_task_struct(pos);
3771	}
3772	rcu_read_unlock();
3773	put_task_struct(start);
3774	return pos;
3775}
3776
3777/* for the /proc/TGID/task/ directories */
3778static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3779{
3780	struct inode *inode = file_inode(file);
3781	struct task_struct *task;
3782	struct pid_namespace *ns;
3783	int tid;
3784
3785	if (proc_inode_is_dead(inode))
3786		return -ENOENT;
3787
3788	if (!dir_emit_dots(file, ctx))
3789		return 0;
3790
3791	/* f_version caches the tgid value that the last readdir call couldn't
3792	 * return. lseek aka telldir automagically resets f_version to 0.
3793	 */
3794	ns = proc_pid_ns(inode->i_sb);
3795	tid = (int)file->f_version;
3796	file->f_version = 0;
3797	for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3798	     task;
3799	     task = next_tid(task), ctx->pos++) {
3800		char name[10 + 1];
3801		unsigned int len;
3802		tid = task_pid_nr_ns(task, ns);
3803		len = snprintf(name, sizeof(name), "%u", tid);
3804		if (!proc_fill_cache(file, ctx, name, len,
3805				proc_task_instantiate, task, NULL)) {
3806			/* returning this tgid failed, save it as the first
3807			 * pid for the next readir call */
3808			file->f_version = (u64)tid;
3809			put_task_struct(task);
3810			break;
3811		}
3812	}
3813
3814	return 0;
3815}
3816
3817static int proc_task_getattr(struct user_namespace *mnt_userns,
3818			     const struct path *path, struct kstat *stat,
3819			     u32 request_mask, unsigned int query_flags)
3820{
3821	struct inode *inode = d_inode(path->dentry);
3822	struct task_struct *p = get_proc_task(inode);
3823	generic_fillattr(&init_user_ns, inode, stat);
3824
3825	if (p) {
3826		stat->nlink += get_nr_threads(p);
3827		put_task_struct(p);
3828	}
3829
3830	return 0;
3831}
3832
3833static const struct inode_operations proc_task_inode_operations = {
3834	.lookup		= proc_task_lookup,
3835	.getattr	= proc_task_getattr,
3836	.setattr	= proc_setattr,
3837	.permission	= proc_pid_permission,
3838};
3839
3840static const struct file_operations proc_task_operations = {
3841	.read		= generic_read_dir,
3842	.iterate_shared	= proc_task_readdir,
3843	.llseek		= generic_file_llseek,
3844};
3845
3846void __init set_proc_pid_nlink(void)
3847{
3848	nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3849	nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3850}
3851