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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/kallsyms.h>
71#include <linux/stacktrace.h>
72#include <linux/resource.h>
73#include <linux/module.h>
74#include <linux/mount.h>
75#include <linux/security.h>
76#include <linux/ptrace.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 char symname[KSYM_NAME_LEN];
390
391 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
392 goto print0;
393
394 wchan = get_wchan(task);
395 if (wchan && !lookup_symbol_name(wchan, symname)) {
396 seq_puts(m, symname);
397 return 0;
398 }
399
400print0:
401 seq_putc(m, '0');
402 return 0;
403}
404#endif /* CONFIG_KALLSYMS */
405
406static int lock_trace(struct task_struct *task)
407{
408 int err = down_read_killable(&task->signal->exec_update_lock);
409 if (err)
410 return err;
411 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
412 up_read(&task->signal->exec_update_lock);
413 return -EPERM;
414 }
415 return 0;
416}
417
418static void unlock_trace(struct task_struct *task)
419{
420 up_read(&task->signal->exec_update_lock);
421}
422
423#ifdef CONFIG_STACKTRACE
424
425#define MAX_STACK_TRACE_DEPTH 64
426
427static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
428 struct pid *pid, struct task_struct *task)
429{
430 unsigned long *entries;
431 int err;
432
433 /*
434 * The ability to racily run the kernel stack unwinder on a running task
435 * and then observe the unwinder output is scary; while it is useful for
436 * debugging kernel issues, it can also allow an attacker to leak kernel
437 * stack contents.
438 * Doing this in a manner that is at least safe from races would require
439 * some work to ensure that the remote task can not be scheduled; and
440 * even then, this would still expose the unwinder as local attack
441 * surface.
442 * Therefore, this interface is restricted to root.
443 */
444 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
445 return -EACCES;
446
447 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
448 GFP_KERNEL);
449 if (!entries)
450 return -ENOMEM;
451
452 err = lock_trace(task);
453 if (!err) {
454 unsigned int i, nr_entries;
455
456 nr_entries = stack_trace_save_tsk(task, entries,
457 MAX_STACK_TRACE_DEPTH, 0);
458
459 for (i = 0; i < nr_entries; i++) {
460 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
461 }
462
463 unlock_trace(task);
464 }
465 kfree(entries);
466
467 return err;
468}
469#endif
470
471#ifdef CONFIG_SCHED_INFO
472/*
473 * Provides /proc/PID/schedstat
474 */
475static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
476 struct pid *pid, struct task_struct *task)
477{
478 if (unlikely(!sched_info_on()))
479 seq_puts(m, "0 0 0\n");
480 else
481 seq_printf(m, "%llu %llu %lu\n",
482 (unsigned long long)task->se.sum_exec_runtime,
483 (unsigned long long)task->sched_info.run_delay,
484 task->sched_info.pcount);
485
486 return 0;
487}
488#endif
489
490#ifdef CONFIG_LATENCYTOP
491static int lstats_show_proc(struct seq_file *m, void *v)
492{
493 int i;
494 struct inode *inode = m->private;
495 struct task_struct *task = get_proc_task(inode);
496
497 if (!task)
498 return -ESRCH;
499 seq_puts(m, "Latency Top version : v0.1\n");
500 for (i = 0; i < LT_SAVECOUNT; i++) {
501 struct latency_record *lr = &task->latency_record[i];
502 if (lr->backtrace[0]) {
503 int q;
504 seq_printf(m, "%i %li %li",
505 lr->count, lr->time, lr->max);
506 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
507 unsigned long bt = lr->backtrace[q];
508
509 if (!bt)
510 break;
511 seq_printf(m, " %ps", (void *)bt);
512 }
513 seq_putc(m, '\n');
514 }
515
516 }
517 put_task_struct(task);
518 return 0;
519}
520
521static int lstats_open(struct inode *inode, struct file *file)
522{
523 return single_open(file, lstats_show_proc, inode);
524}
525
526static ssize_t lstats_write(struct file *file, const char __user *buf,
527 size_t count, loff_t *offs)
528{
529 struct task_struct *task = get_proc_task(file_inode(file));
530
531 if (!task)
532 return -ESRCH;
533 clear_tsk_latency_tracing(task);
534 put_task_struct(task);
535
536 return count;
537}
538
539static const struct file_operations proc_lstats_operations = {
540 .open = lstats_open,
541 .read = seq_read,
542 .write = lstats_write,
543 .llseek = seq_lseek,
544 .release = single_release,
545};
546
547#endif
548
549static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
550 struct pid *pid, struct task_struct *task)
551{
552 unsigned long totalpages = totalram_pages() + total_swap_pages;
553 unsigned long points = 0;
554 long badness;
555
556 badness = oom_badness(task, totalpages);
557 /*
558 * Special case OOM_SCORE_ADJ_MIN for all others scale the
559 * badness value into [0, 2000] range which we have been
560 * exporting for a long time so userspace might depend on it.
561 */
562 if (badness != LONG_MIN)
563 points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3;
564
565 seq_printf(m, "%lu\n", points);
566
567 return 0;
568}
569
570struct limit_names {
571 const char *name;
572 const char *unit;
573};
574
575static const struct limit_names lnames[RLIM_NLIMITS] = {
576 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
577 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
578 [RLIMIT_DATA] = {"Max data size", "bytes"},
579 [RLIMIT_STACK] = {"Max stack size", "bytes"},
580 [RLIMIT_CORE] = {"Max core file size", "bytes"},
581 [RLIMIT_RSS] = {"Max resident set", "bytes"},
582 [RLIMIT_NPROC] = {"Max processes", "processes"},
583 [RLIMIT_NOFILE] = {"Max open files", "files"},
584 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
585 [RLIMIT_AS] = {"Max address space", "bytes"},
586 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
587 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
588 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
589 [RLIMIT_NICE] = {"Max nice priority", NULL},
590 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
591 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
592};
593
594/* Display limits for a process */
595static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
596 struct pid *pid, struct task_struct *task)
597{
598 unsigned int i;
599 unsigned long flags;
600
601 struct rlimit rlim[RLIM_NLIMITS];
602
603 if (!lock_task_sighand(task, &flags))
604 return 0;
605 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
606 unlock_task_sighand(task, &flags);
607
608 /*
609 * print the file header
610 */
611 seq_puts(m, "Limit "
612 "Soft Limit "
613 "Hard Limit "
614 "Units \n");
615
616 for (i = 0; i < RLIM_NLIMITS; i++) {
617 if (rlim[i].rlim_cur == RLIM_INFINITY)
618 seq_printf(m, "%-25s %-20s ",
619 lnames[i].name, "unlimited");
620 else
621 seq_printf(m, "%-25s %-20lu ",
622 lnames[i].name, rlim[i].rlim_cur);
623
624 if (rlim[i].rlim_max == RLIM_INFINITY)
625 seq_printf(m, "%-20s ", "unlimited");
626 else
627 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
628
629 if (lnames[i].unit)
630 seq_printf(m, "%-10s\n", lnames[i].unit);
631 else
632 seq_putc(m, '\n');
633 }
634
635 return 0;
636}
637
638#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
639static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
640 struct pid *pid, struct task_struct *task)
641{
642 struct syscall_info info;
643 u64 *args = &info.data.args[0];
644 int res;
645
646 res = lock_trace(task);
647 if (res)
648 return res;
649
650 if (task_current_syscall(task, &info))
651 seq_puts(m, "running\n");
652 else if (info.data.nr < 0)
653 seq_printf(m, "%d 0x%llx 0x%llx\n",
654 info.data.nr, info.sp, info.data.instruction_pointer);
655 else
656 seq_printf(m,
657 "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
658 info.data.nr,
659 args[0], args[1], args[2], args[3], args[4], args[5],
660 info.sp, info.data.instruction_pointer);
661 unlock_trace(task);
662
663 return 0;
664}
665#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
666
667/************************************************************************/
668/* Here the fs part begins */
669/************************************************************************/
670
671/* permission checks */
672static bool proc_fd_access_allowed(struct inode *inode)
673{
674 struct task_struct *task;
675 bool allowed = false;
676 /* Allow access to a task's file descriptors if it is us or we
677 * may use ptrace attach to the process and find out that
678 * information.
679 */
680 task = get_proc_task(inode);
681 if (task) {
682 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
683 put_task_struct(task);
684 }
685 return allowed;
686}
687
688int proc_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
689 struct iattr *attr)
690{
691 int error;
692 struct inode *inode = d_inode(dentry);
693
694 if (attr->ia_valid & ATTR_MODE)
695 return -EPERM;
696
697 error = setattr_prepare(&init_user_ns, dentry, attr);
698 if (error)
699 return error;
700
701 setattr_copy(&init_user_ns, inode, attr);
702 mark_inode_dirty(inode);
703 return 0;
704}
705
706/*
707 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
708 * or euid/egid (for hide_pid_min=2)?
709 */
710static bool has_pid_permissions(struct proc_fs_info *fs_info,
711 struct task_struct *task,
712 enum proc_hidepid hide_pid_min)
713{
714 /*
715 * If 'hidpid' mount option is set force a ptrace check,
716 * we indicate that we are using a filesystem syscall
717 * by passing PTRACE_MODE_READ_FSCREDS
718 */
719 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE)
720 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
721
722 if (fs_info->hide_pid < hide_pid_min)
723 return true;
724 if (in_group_p(fs_info->pid_gid))
725 return true;
726 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
727}
728
729
730static int proc_pid_permission(struct user_namespace *mnt_userns,
731 struct inode *inode, int mask)
732{
733 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
734 struct task_struct *task;
735 bool has_perms;
736
737 task = get_proc_task(inode);
738 if (!task)
739 return -ESRCH;
740 has_perms = has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS);
741 put_task_struct(task);
742
743 if (!has_perms) {
744 if (fs_info->hide_pid == HIDEPID_INVISIBLE) {
745 /*
746 * Let's make getdents(), stat(), and open()
747 * consistent with each other. If a process
748 * may not stat() a file, it shouldn't be seen
749 * in procfs at all.
750 */
751 return -ENOENT;
752 }
753
754 return -EPERM;
755 }
756 return generic_permission(&init_user_ns, inode, mask);
757}
758
759
760
761static const struct inode_operations proc_def_inode_operations = {
762 .setattr = proc_setattr,
763};
764
765static int proc_single_show(struct seq_file *m, void *v)
766{
767 struct inode *inode = m->private;
768 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
769 struct pid *pid = proc_pid(inode);
770 struct task_struct *task;
771 int ret;
772
773 task = get_pid_task(pid, PIDTYPE_PID);
774 if (!task)
775 return -ESRCH;
776
777 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
778
779 put_task_struct(task);
780 return ret;
781}
782
783static int proc_single_open(struct inode *inode, struct file *filp)
784{
785 return single_open(filp, proc_single_show, inode);
786}
787
788static const struct file_operations proc_single_file_operations = {
789 .open = proc_single_open,
790 .read = seq_read,
791 .llseek = seq_lseek,
792 .release = single_release,
793};
794
795
796struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
797{
798 struct task_struct *task = get_proc_task(inode);
799 struct mm_struct *mm = ERR_PTR(-ESRCH);
800
801 if (task) {
802 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
803 put_task_struct(task);
804
805 if (!IS_ERR_OR_NULL(mm)) {
806 /* ensure this mm_struct can't be freed */
807 mmgrab(mm);
808 /* but do not pin its memory */
809 mmput(mm);
810 }
811 }
812
813 return mm;
814}
815
816static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
817{
818 struct mm_struct *mm = proc_mem_open(inode, mode);
819
820 if (IS_ERR(mm))
821 return PTR_ERR(mm);
822
823 file->private_data = mm;
824 return 0;
825}
826
827static int mem_open(struct inode *inode, struct file *file)
828{
829 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
830
831 /* OK to pass negative loff_t, we can catch out-of-range */
832 file->f_mode |= FMODE_UNSIGNED_OFFSET;
833
834 return ret;
835}
836
837static ssize_t mem_rw(struct file *file, char __user *buf,
838 size_t count, loff_t *ppos, int write)
839{
840 struct mm_struct *mm = file->private_data;
841 unsigned long addr = *ppos;
842 ssize_t copied;
843 char *page;
844 unsigned int flags;
845
846 if (!mm)
847 return 0;
848
849 page = (char *)__get_free_page(GFP_KERNEL);
850 if (!page)
851 return -ENOMEM;
852
853 copied = 0;
854 if (!mmget_not_zero(mm))
855 goto free;
856
857 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
858
859 while (count > 0) {
860 size_t this_len = min_t(size_t, count, PAGE_SIZE);
861
862 if (write && copy_from_user(page, buf, this_len)) {
863 copied = -EFAULT;
864 break;
865 }
866
867 this_len = access_remote_vm(mm, addr, page, this_len, flags);
868 if (!this_len) {
869 if (!copied)
870 copied = -EIO;
871 break;
872 }
873
874 if (!write && copy_to_user(buf, page, this_len)) {
875 copied = -EFAULT;
876 break;
877 }
878
879 buf += this_len;
880 addr += this_len;
881 copied += this_len;
882 count -= this_len;
883 }
884 *ppos = addr;
885
886 mmput(mm);
887free:
888 free_page((unsigned long) page);
889 return copied;
890}
891
892static ssize_t mem_read(struct file *file, char __user *buf,
893 size_t count, loff_t *ppos)
894{
895 return mem_rw(file, buf, count, ppos, 0);
896}
897
898static ssize_t mem_write(struct file *file, const char __user *buf,
899 size_t count, loff_t *ppos)
900{
901 return mem_rw(file, (char __user*)buf, count, ppos, 1);
902}
903
904loff_t mem_lseek(struct file *file, loff_t offset, int orig)
905{
906 switch (orig) {
907 case 0:
908 file->f_pos = offset;
909 break;
910 case 1:
911 file->f_pos += offset;
912 break;
913 default:
914 return -EINVAL;
915 }
916 force_successful_syscall_return();
917 return file->f_pos;
918}
919
920static int mem_release(struct inode *inode, struct file *file)
921{
922 struct mm_struct *mm = file->private_data;
923 if (mm)
924 mmdrop(mm);
925 return 0;
926}
927
928static const struct file_operations proc_mem_operations = {
929 .llseek = mem_lseek,
930 .read = mem_read,
931 .write = mem_write,
932 .open = mem_open,
933 .release = mem_release,
934};
935
936static int environ_open(struct inode *inode, struct file *file)
937{
938 return __mem_open(inode, file, PTRACE_MODE_READ);
939}
940
941static ssize_t environ_read(struct file *file, char __user *buf,
942 size_t count, loff_t *ppos)
943{
944 char *page;
945 unsigned long src = *ppos;
946 int ret = 0;
947 struct mm_struct *mm = file->private_data;
948 unsigned long env_start, env_end;
949
950 /* Ensure the process spawned far enough to have an environment. */
951 if (!mm || !mm->env_end)
952 return 0;
953
954 page = (char *)__get_free_page(GFP_KERNEL);
955 if (!page)
956 return -ENOMEM;
957
958 ret = 0;
959 if (!mmget_not_zero(mm))
960 goto free;
961
962 spin_lock(&mm->arg_lock);
963 env_start = mm->env_start;
964 env_end = mm->env_end;
965 spin_unlock(&mm->arg_lock);
966
967 while (count > 0) {
968 size_t this_len, max_len;
969 int retval;
970
971 if (src >= (env_end - env_start))
972 break;
973
974 this_len = env_end - (env_start + src);
975
976 max_len = min_t(size_t, PAGE_SIZE, count);
977 this_len = min(max_len, this_len);
978
979 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
980
981 if (retval <= 0) {
982 ret = retval;
983 break;
984 }
985
986 if (copy_to_user(buf, page, retval)) {
987 ret = -EFAULT;
988 break;
989 }
990
991 ret += retval;
992 src += retval;
993 buf += retval;
994 count -= retval;
995 }
996 *ppos = src;
997 mmput(mm);
998
999free:
1000 free_page((unsigned long) page);
1001 return ret;
1002}
1003
1004static const struct file_operations proc_environ_operations = {
1005 .open = environ_open,
1006 .read = environ_read,
1007 .llseek = generic_file_llseek,
1008 .release = mem_release,
1009};
1010
1011static int auxv_open(struct inode *inode, struct file *file)
1012{
1013 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1014}
1015
1016static ssize_t auxv_read(struct file *file, char __user *buf,
1017 size_t count, loff_t *ppos)
1018{
1019 struct mm_struct *mm = file->private_data;
1020 unsigned int nwords = 0;
1021
1022 if (!mm)
1023 return 0;
1024 do {
1025 nwords += 2;
1026 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1027 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1028 nwords * sizeof(mm->saved_auxv[0]));
1029}
1030
1031static const struct file_operations proc_auxv_operations = {
1032 .open = auxv_open,
1033 .read = auxv_read,
1034 .llseek = generic_file_llseek,
1035 .release = mem_release,
1036};
1037
1038static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1039 loff_t *ppos)
1040{
1041 struct task_struct *task = get_proc_task(file_inode(file));
1042 char buffer[PROC_NUMBUF];
1043 int oom_adj = OOM_ADJUST_MIN;
1044 size_t len;
1045
1046 if (!task)
1047 return -ESRCH;
1048 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1049 oom_adj = OOM_ADJUST_MAX;
1050 else
1051 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1052 OOM_SCORE_ADJ_MAX;
1053 put_task_struct(task);
1054 if (oom_adj > OOM_ADJUST_MAX)
1055 oom_adj = OOM_ADJUST_MAX;
1056 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1057 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1058}
1059
1060static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1061{
1062 struct mm_struct *mm = NULL;
1063 struct task_struct *task;
1064 int err = 0;
1065
1066 task = get_proc_task(file_inode(file));
1067 if (!task)
1068 return -ESRCH;
1069
1070 mutex_lock(&oom_adj_mutex);
1071 if (legacy) {
1072 if (oom_adj < task->signal->oom_score_adj &&
1073 !capable(CAP_SYS_RESOURCE)) {
1074 err = -EACCES;
1075 goto err_unlock;
1076 }
1077 /*
1078 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1079 * /proc/pid/oom_score_adj instead.
1080 */
1081 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1082 current->comm, task_pid_nr(current), task_pid_nr(task),
1083 task_pid_nr(task));
1084 } else {
1085 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1086 !capable(CAP_SYS_RESOURCE)) {
1087 err = -EACCES;
1088 goto err_unlock;
1089 }
1090 }
1091
1092 /*
1093 * Make sure we will check other processes sharing the mm if this is
1094 * not vfrok which wants its own oom_score_adj.
1095 * pin the mm so it doesn't go away and get reused after task_unlock
1096 */
1097 if (!task->vfork_done) {
1098 struct task_struct *p = find_lock_task_mm(task);
1099
1100 if (p) {
1101 if (test_bit(MMF_MULTIPROCESS, &p->mm->flags)) {
1102 mm = p->mm;
1103 mmgrab(mm);
1104 }
1105 task_unlock(p);
1106 }
1107 }
1108
1109 task->signal->oom_score_adj = oom_adj;
1110 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1111 task->signal->oom_score_adj_min = (short)oom_adj;
1112 trace_oom_score_adj_update(task);
1113
1114 if (mm) {
1115 struct task_struct *p;
1116
1117 rcu_read_lock();
1118 for_each_process(p) {
1119 if (same_thread_group(task, p))
1120 continue;
1121
1122 /* do not touch kernel threads or the global init */
1123 if (p->flags & PF_KTHREAD || is_global_init(p))
1124 continue;
1125
1126 task_lock(p);
1127 if (!p->vfork_done && process_shares_mm(p, mm)) {
1128 p->signal->oom_score_adj = oom_adj;
1129 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1130 p->signal->oom_score_adj_min = (short)oom_adj;
1131 }
1132 task_unlock(p);
1133 }
1134 rcu_read_unlock();
1135 mmdrop(mm);
1136 }
1137err_unlock:
1138 mutex_unlock(&oom_adj_mutex);
1139 put_task_struct(task);
1140 return err;
1141}
1142
1143/*
1144 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1145 * kernels. The effective policy is defined by oom_score_adj, which has a
1146 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1147 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1148 * Processes that become oom disabled via oom_adj will still be oom disabled
1149 * with this implementation.
1150 *
1151 * oom_adj cannot be removed since existing userspace binaries use it.
1152 */
1153static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1154 size_t count, loff_t *ppos)
1155{
1156 char buffer[PROC_NUMBUF];
1157 int oom_adj;
1158 int err;
1159
1160 memset(buffer, 0, sizeof(buffer));
1161 if (count > sizeof(buffer) - 1)
1162 count = sizeof(buffer) - 1;
1163 if (copy_from_user(buffer, buf, count)) {
1164 err = -EFAULT;
1165 goto out;
1166 }
1167
1168 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1169 if (err)
1170 goto out;
1171 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1172 oom_adj != OOM_DISABLE) {
1173 err = -EINVAL;
1174 goto out;
1175 }
1176
1177 /*
1178 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1179 * value is always attainable.
1180 */
1181 if (oom_adj == OOM_ADJUST_MAX)
1182 oom_adj = OOM_SCORE_ADJ_MAX;
1183 else
1184 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1185
1186 err = __set_oom_adj(file, oom_adj, true);
1187out:
1188 return err < 0 ? err : count;
1189}
1190
1191static const struct file_operations proc_oom_adj_operations = {
1192 .read = oom_adj_read,
1193 .write = oom_adj_write,
1194 .llseek = generic_file_llseek,
1195};
1196
1197static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1198 size_t count, loff_t *ppos)
1199{
1200 struct task_struct *task = get_proc_task(file_inode(file));
1201 char buffer[PROC_NUMBUF];
1202 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1203 size_t len;
1204
1205 if (!task)
1206 return -ESRCH;
1207 oom_score_adj = task->signal->oom_score_adj;
1208 put_task_struct(task);
1209 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1210 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1211}
1212
1213static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1214 size_t count, loff_t *ppos)
1215{
1216 char buffer[PROC_NUMBUF];
1217 int oom_score_adj;
1218 int err;
1219
1220 memset(buffer, 0, sizeof(buffer));
1221 if (count > sizeof(buffer) - 1)
1222 count = sizeof(buffer) - 1;
1223 if (copy_from_user(buffer, buf, count)) {
1224 err = -EFAULT;
1225 goto out;
1226 }
1227
1228 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1229 if (err)
1230 goto out;
1231 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1232 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1233 err = -EINVAL;
1234 goto out;
1235 }
1236
1237 err = __set_oom_adj(file, oom_score_adj, false);
1238out:
1239 return err < 0 ? err : count;
1240}
1241
1242static const struct file_operations proc_oom_score_adj_operations = {
1243 .read = oom_score_adj_read,
1244 .write = oom_score_adj_write,
1245 .llseek = default_llseek,
1246};
1247
1248#ifdef CONFIG_AUDIT
1249#define TMPBUFLEN 11
1250static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1251 size_t count, loff_t *ppos)
1252{
1253 struct inode * inode = file_inode(file);
1254 struct task_struct *task = get_proc_task(inode);
1255 ssize_t length;
1256 char tmpbuf[TMPBUFLEN];
1257
1258 if (!task)
1259 return -ESRCH;
1260 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1261 from_kuid(file->f_cred->user_ns,
1262 audit_get_loginuid(task)));
1263 put_task_struct(task);
1264 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1265}
1266
1267static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1268 size_t count, loff_t *ppos)
1269{
1270 struct inode * inode = file_inode(file);
1271 uid_t loginuid;
1272 kuid_t kloginuid;
1273 int rv;
1274
1275 /* Don't let kthreads write their own loginuid */
1276 if (current->flags & PF_KTHREAD)
1277 return -EPERM;
1278
1279 rcu_read_lock();
1280 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1281 rcu_read_unlock();
1282 return -EPERM;
1283 }
1284 rcu_read_unlock();
1285
1286 if (*ppos != 0) {
1287 /* No partial writes. */
1288 return -EINVAL;
1289 }
1290
1291 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1292 if (rv < 0)
1293 return rv;
1294
1295 /* is userspace tring to explicitly UNSET the loginuid? */
1296 if (loginuid == AUDIT_UID_UNSET) {
1297 kloginuid = INVALID_UID;
1298 } else {
1299 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1300 if (!uid_valid(kloginuid))
1301 return -EINVAL;
1302 }
1303
1304 rv = audit_set_loginuid(kloginuid);
1305 if (rv < 0)
1306 return rv;
1307 return count;
1308}
1309
1310static const struct file_operations proc_loginuid_operations = {
1311 .read = proc_loginuid_read,
1312 .write = proc_loginuid_write,
1313 .llseek = generic_file_llseek,
1314};
1315
1316static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1317 size_t count, loff_t *ppos)
1318{
1319 struct inode * inode = file_inode(file);
1320 struct task_struct *task = get_proc_task(inode);
1321 ssize_t length;
1322 char tmpbuf[TMPBUFLEN];
1323
1324 if (!task)
1325 return -ESRCH;
1326 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1327 audit_get_sessionid(task));
1328 put_task_struct(task);
1329 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1330}
1331
1332static const struct file_operations proc_sessionid_operations = {
1333 .read = proc_sessionid_read,
1334 .llseek = generic_file_llseek,
1335};
1336#endif
1337
1338#ifdef CONFIG_FAULT_INJECTION
1339static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1340 size_t count, loff_t *ppos)
1341{
1342 struct task_struct *task = get_proc_task(file_inode(file));
1343 char buffer[PROC_NUMBUF];
1344 size_t len;
1345 int make_it_fail;
1346
1347 if (!task)
1348 return -ESRCH;
1349 make_it_fail = task->make_it_fail;
1350 put_task_struct(task);
1351
1352 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1353
1354 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1355}
1356
1357static ssize_t proc_fault_inject_write(struct file * file,
1358 const char __user * buf, size_t count, loff_t *ppos)
1359{
1360 struct task_struct *task;
1361 char buffer[PROC_NUMBUF];
1362 int make_it_fail;
1363 int rv;
1364
1365 if (!capable(CAP_SYS_RESOURCE))
1366 return -EPERM;
1367 memset(buffer, 0, sizeof(buffer));
1368 if (count > sizeof(buffer) - 1)
1369 count = sizeof(buffer) - 1;
1370 if (copy_from_user(buffer, buf, count))
1371 return -EFAULT;
1372 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1373 if (rv < 0)
1374 return rv;
1375 if (make_it_fail < 0 || make_it_fail > 1)
1376 return -EINVAL;
1377
1378 task = get_proc_task(file_inode(file));
1379 if (!task)
1380 return -ESRCH;
1381 task->make_it_fail = make_it_fail;
1382 put_task_struct(task);
1383
1384 return count;
1385}
1386
1387static const struct file_operations proc_fault_inject_operations = {
1388 .read = proc_fault_inject_read,
1389 .write = proc_fault_inject_write,
1390 .llseek = generic_file_llseek,
1391};
1392
1393static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1394 size_t count, loff_t *ppos)
1395{
1396 struct task_struct *task;
1397 int err;
1398 unsigned int n;
1399
1400 err = kstrtouint_from_user(buf, count, 0, &n);
1401 if (err)
1402 return err;
1403
1404 task = get_proc_task(file_inode(file));
1405 if (!task)
1406 return -ESRCH;
1407 task->fail_nth = n;
1408 put_task_struct(task);
1409
1410 return count;
1411}
1412
1413static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1414 size_t count, loff_t *ppos)
1415{
1416 struct task_struct *task;
1417 char numbuf[PROC_NUMBUF];
1418 ssize_t len;
1419
1420 task = get_proc_task(file_inode(file));
1421 if (!task)
1422 return -ESRCH;
1423 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1424 put_task_struct(task);
1425 return simple_read_from_buffer(buf, count, ppos, numbuf, len);
1426}
1427
1428static const struct file_operations proc_fail_nth_operations = {
1429 .read = proc_fail_nth_read,
1430 .write = proc_fail_nth_write,
1431};
1432#endif
1433
1434
1435#ifdef CONFIG_SCHED_DEBUG
1436/*
1437 * Print out various scheduling related per-task fields:
1438 */
1439static int sched_show(struct seq_file *m, void *v)
1440{
1441 struct inode *inode = m->private;
1442 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
1443 struct task_struct *p;
1444
1445 p = get_proc_task(inode);
1446 if (!p)
1447 return -ESRCH;
1448 proc_sched_show_task(p, ns, m);
1449
1450 put_task_struct(p);
1451
1452 return 0;
1453}
1454
1455static ssize_t
1456sched_write(struct file *file, const char __user *buf,
1457 size_t count, loff_t *offset)
1458{
1459 struct inode *inode = file_inode(file);
1460 struct task_struct *p;
1461
1462 p = get_proc_task(inode);
1463 if (!p)
1464 return -ESRCH;
1465 proc_sched_set_task(p);
1466
1467 put_task_struct(p);
1468
1469 return count;
1470}
1471
1472static int sched_open(struct inode *inode, struct file *filp)
1473{
1474 return single_open(filp, sched_show, inode);
1475}
1476
1477static const struct file_operations proc_pid_sched_operations = {
1478 .open = sched_open,
1479 .read = seq_read,
1480 .write = sched_write,
1481 .llseek = seq_lseek,
1482 .release = single_release,
1483};
1484
1485#endif
1486
1487#ifdef CONFIG_SCHED_AUTOGROUP
1488/*
1489 * Print out autogroup related information:
1490 */
1491static int sched_autogroup_show(struct seq_file *m, void *v)
1492{
1493 struct inode *inode = m->private;
1494 struct task_struct *p;
1495
1496 p = get_proc_task(inode);
1497 if (!p)
1498 return -ESRCH;
1499 proc_sched_autogroup_show_task(p, m);
1500
1501 put_task_struct(p);
1502
1503 return 0;
1504}
1505
1506static ssize_t
1507sched_autogroup_write(struct file *file, const char __user *buf,
1508 size_t count, loff_t *offset)
1509{
1510 struct inode *inode = file_inode(file);
1511 struct task_struct *p;
1512 char buffer[PROC_NUMBUF];
1513 int nice;
1514 int err;
1515
1516 memset(buffer, 0, sizeof(buffer));
1517 if (count > sizeof(buffer) - 1)
1518 count = sizeof(buffer) - 1;
1519 if (copy_from_user(buffer, buf, count))
1520 return -EFAULT;
1521
1522 err = kstrtoint(strstrip(buffer), 0, &nice);
1523 if (err < 0)
1524 return err;
1525
1526 p = get_proc_task(inode);
1527 if (!p)
1528 return -ESRCH;
1529
1530 err = proc_sched_autogroup_set_nice(p, nice);
1531 if (err)
1532 count = err;
1533
1534 put_task_struct(p);
1535
1536 return count;
1537}
1538
1539static int sched_autogroup_open(struct inode *inode, struct file *filp)
1540{
1541 int ret;
1542
1543 ret = single_open(filp, sched_autogroup_show, NULL);
1544 if (!ret) {
1545 struct seq_file *m = filp->private_data;
1546
1547 m->private = inode;
1548 }
1549 return ret;
1550}
1551
1552static const struct file_operations proc_pid_sched_autogroup_operations = {
1553 .open = sched_autogroup_open,
1554 .read = seq_read,
1555 .write = sched_autogroup_write,
1556 .llseek = seq_lseek,
1557 .release = single_release,
1558};
1559
1560#endif /* CONFIG_SCHED_AUTOGROUP */
1561
1562#ifdef CONFIG_TIME_NS
1563static int timens_offsets_show(struct seq_file *m, void *v)
1564{
1565 struct task_struct *p;
1566
1567 p = get_proc_task(file_inode(m->file));
1568 if (!p)
1569 return -ESRCH;
1570 proc_timens_show_offsets(p, m);
1571
1572 put_task_struct(p);
1573
1574 return 0;
1575}
1576
1577static ssize_t timens_offsets_write(struct file *file, const char __user *buf,
1578 size_t count, loff_t *ppos)
1579{
1580 struct inode *inode = file_inode(file);
1581 struct proc_timens_offset offsets[2];
1582 char *kbuf = NULL, *pos, *next_line;
1583 struct task_struct *p;
1584 int ret, noffsets;
1585
1586 /* Only allow < page size writes at the beginning of the file */
1587 if ((*ppos != 0) || (count >= PAGE_SIZE))
1588 return -EINVAL;
1589
1590 /* Slurp in the user data */
1591 kbuf = memdup_user_nul(buf, count);
1592 if (IS_ERR(kbuf))
1593 return PTR_ERR(kbuf);
1594
1595 /* Parse the user data */
1596 ret = -EINVAL;
1597 noffsets = 0;
1598 for (pos = kbuf; pos; pos = next_line) {
1599 struct proc_timens_offset *off = &offsets[noffsets];
1600 char clock[10];
1601 int err;
1602
1603 /* Find the end of line and ensure we don't look past it */
1604 next_line = strchr(pos, '\n');
1605 if (next_line) {
1606 *next_line = '\0';
1607 next_line++;
1608 if (*next_line == '\0')
1609 next_line = NULL;
1610 }
1611
1612 err = sscanf(pos, "%9s %lld %lu", clock,
1613 &off->val.tv_sec, &off->val.tv_nsec);
1614 if (err != 3 || off->val.tv_nsec >= NSEC_PER_SEC)
1615 goto out;
1616
1617 clock[sizeof(clock) - 1] = 0;
1618 if (strcmp(clock, "monotonic") == 0 ||
1619 strcmp(clock, __stringify(CLOCK_MONOTONIC)) == 0)
1620 off->clockid = CLOCK_MONOTONIC;
1621 else if (strcmp(clock, "boottime") == 0 ||
1622 strcmp(clock, __stringify(CLOCK_BOOTTIME)) == 0)
1623 off->clockid = CLOCK_BOOTTIME;
1624 else
1625 goto out;
1626
1627 noffsets++;
1628 if (noffsets == ARRAY_SIZE(offsets)) {
1629 if (next_line)
1630 count = next_line - kbuf;
1631 break;
1632 }
1633 }
1634
1635 ret = -ESRCH;
1636 p = get_proc_task(inode);
1637 if (!p)
1638 goto out;
1639 ret = proc_timens_set_offset(file, p, offsets, noffsets);
1640 put_task_struct(p);
1641 if (ret)
1642 goto out;
1643
1644 ret = count;
1645out:
1646 kfree(kbuf);
1647 return ret;
1648}
1649
1650static int timens_offsets_open(struct inode *inode, struct file *filp)
1651{
1652 return single_open(filp, timens_offsets_show, inode);
1653}
1654
1655static const struct file_operations proc_timens_offsets_operations = {
1656 .open = timens_offsets_open,
1657 .read = seq_read,
1658 .write = timens_offsets_write,
1659 .llseek = seq_lseek,
1660 .release = single_release,
1661};
1662#endif /* CONFIG_TIME_NS */
1663
1664static ssize_t comm_write(struct file *file, const char __user *buf,
1665 size_t count, loff_t *offset)
1666{
1667 struct inode *inode = file_inode(file);
1668 struct task_struct *p;
1669 char buffer[TASK_COMM_LEN];
1670 const size_t maxlen = sizeof(buffer) - 1;
1671
1672 memset(buffer, 0, sizeof(buffer));
1673 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1674 return -EFAULT;
1675
1676 p = get_proc_task(inode);
1677 if (!p)
1678 return -ESRCH;
1679
1680 if (same_thread_group(current, p)) {
1681 set_task_comm(p, buffer);
1682 proc_comm_connector(p);
1683 }
1684 else
1685 count = -EINVAL;
1686
1687 put_task_struct(p);
1688
1689 return count;
1690}
1691
1692static int comm_show(struct seq_file *m, void *v)
1693{
1694 struct inode *inode = m->private;
1695 struct task_struct *p;
1696
1697 p = get_proc_task(inode);
1698 if (!p)
1699 return -ESRCH;
1700
1701 proc_task_name(m, p, false);
1702 seq_putc(m, '\n');
1703
1704 put_task_struct(p);
1705
1706 return 0;
1707}
1708
1709static int comm_open(struct inode *inode, struct file *filp)
1710{
1711 return single_open(filp, comm_show, inode);
1712}
1713
1714static const struct file_operations proc_pid_set_comm_operations = {
1715 .open = comm_open,
1716 .read = seq_read,
1717 .write = comm_write,
1718 .llseek = seq_lseek,
1719 .release = single_release,
1720};
1721
1722static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1723{
1724 struct task_struct *task;
1725 struct file *exe_file;
1726
1727 task = get_proc_task(d_inode(dentry));
1728 if (!task)
1729 return -ENOENT;
1730 exe_file = get_task_exe_file(task);
1731 put_task_struct(task);
1732 if (exe_file) {
1733 *exe_path = exe_file->f_path;
1734 path_get(&exe_file->f_path);
1735 fput(exe_file);
1736 return 0;
1737 } else
1738 return -ENOENT;
1739}
1740
1741static const char *proc_pid_get_link(struct dentry *dentry,
1742 struct inode *inode,
1743 struct delayed_call *done)
1744{
1745 struct path path;
1746 int error = -EACCES;
1747
1748 if (!dentry)
1749 return ERR_PTR(-ECHILD);
1750
1751 /* Are we allowed to snoop on the tasks file descriptors? */
1752 if (!proc_fd_access_allowed(inode))
1753 goto out;
1754
1755 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1756 if (error)
1757 goto out;
1758
1759 error = nd_jump_link(&path);
1760out:
1761 return ERR_PTR(error);
1762}
1763
1764static int do_proc_readlink(const struct path *path, char __user *buffer, int buflen)
1765{
1766 char *tmp = kmalloc(PATH_MAX, GFP_KERNEL);
1767 char *pathname;
1768 int len;
1769
1770 if (!tmp)
1771 return -ENOMEM;
1772
1773 pathname = d_path(path, tmp, PATH_MAX);
1774 len = PTR_ERR(pathname);
1775 if (IS_ERR(pathname))
1776 goto out;
1777 len = tmp + PATH_MAX - 1 - pathname;
1778
1779 if (len > buflen)
1780 len = buflen;
1781 if (copy_to_user(buffer, pathname, len))
1782 len = -EFAULT;
1783 out:
1784 kfree(tmp);
1785 return len;
1786}
1787
1788static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1789{
1790 int error = -EACCES;
1791 struct inode *inode = d_inode(dentry);
1792 struct path path;
1793
1794 /* Are we allowed to snoop on the tasks file descriptors? */
1795 if (!proc_fd_access_allowed(inode))
1796 goto out;
1797
1798 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1799 if (error)
1800 goto out;
1801
1802 error = do_proc_readlink(&path, buffer, buflen);
1803 path_put(&path);
1804out:
1805 return error;
1806}
1807
1808const struct inode_operations proc_pid_link_inode_operations = {
1809 .readlink = proc_pid_readlink,
1810 .get_link = proc_pid_get_link,
1811 .setattr = proc_setattr,
1812};
1813
1814
1815/* building an inode */
1816
1817void task_dump_owner(struct task_struct *task, umode_t mode,
1818 kuid_t *ruid, kgid_t *rgid)
1819{
1820 /* Depending on the state of dumpable compute who should own a
1821 * proc file for a task.
1822 */
1823 const struct cred *cred;
1824 kuid_t uid;
1825 kgid_t gid;
1826
1827 if (unlikely(task->flags & PF_KTHREAD)) {
1828 *ruid = GLOBAL_ROOT_UID;
1829 *rgid = GLOBAL_ROOT_GID;
1830 return;
1831 }
1832
1833 /* Default to the tasks effective ownership */
1834 rcu_read_lock();
1835 cred = __task_cred(task);
1836 uid = cred->euid;
1837 gid = cred->egid;
1838 rcu_read_unlock();
1839
1840 /*
1841 * Before the /proc/pid/status file was created the only way to read
1842 * the effective uid of a /process was to stat /proc/pid. Reading
1843 * /proc/pid/status is slow enough that procps and other packages
1844 * kept stating /proc/pid. To keep the rules in /proc simple I have
1845 * made this apply to all per process world readable and executable
1846 * directories.
1847 */
1848 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1849 struct mm_struct *mm;
1850 task_lock(task);
1851 mm = task->mm;
1852 /* Make non-dumpable tasks owned by some root */
1853 if (mm) {
1854 if (get_dumpable(mm) != SUID_DUMP_USER) {
1855 struct user_namespace *user_ns = mm->user_ns;
1856
1857 uid = make_kuid(user_ns, 0);
1858 if (!uid_valid(uid))
1859 uid = GLOBAL_ROOT_UID;
1860
1861 gid = make_kgid(user_ns, 0);
1862 if (!gid_valid(gid))
1863 gid = GLOBAL_ROOT_GID;
1864 }
1865 } else {
1866 uid = GLOBAL_ROOT_UID;
1867 gid = GLOBAL_ROOT_GID;
1868 }
1869 task_unlock(task);
1870 }
1871 *ruid = uid;
1872 *rgid = gid;
1873}
1874
1875void proc_pid_evict_inode(struct proc_inode *ei)
1876{
1877 struct pid *pid = ei->pid;
1878
1879 if (S_ISDIR(ei->vfs_inode.i_mode)) {
1880 spin_lock(&pid->lock);
1881 hlist_del_init_rcu(&ei->sibling_inodes);
1882 spin_unlock(&pid->lock);
1883 }
1884
1885 put_pid(pid);
1886}
1887
1888struct inode *proc_pid_make_inode(struct super_block *sb,
1889 struct task_struct *task, umode_t mode)
1890{
1891 struct inode * inode;
1892 struct proc_inode *ei;
1893 struct pid *pid;
1894
1895 /* We need a new inode */
1896
1897 inode = new_inode(sb);
1898 if (!inode)
1899 goto out;
1900
1901 /* Common stuff */
1902 ei = PROC_I(inode);
1903 inode->i_mode = mode;
1904 inode->i_ino = get_next_ino();
1905 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1906 inode->i_op = &proc_def_inode_operations;
1907
1908 /*
1909 * grab the reference to task.
1910 */
1911 pid = get_task_pid(task, PIDTYPE_PID);
1912 if (!pid)
1913 goto out_unlock;
1914
1915 /* Let the pid remember us for quick removal */
1916 ei->pid = pid;
1917
1918 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1919 security_task_to_inode(task, inode);
1920
1921out:
1922 return inode;
1923
1924out_unlock:
1925 iput(inode);
1926 return NULL;
1927}
1928
1929/*
1930 * Generating an inode and adding it into @pid->inodes, so that task will
1931 * invalidate inode's dentry before being released.
1932 *
1933 * This helper is used for creating dir-type entries under '/proc' and
1934 * '/proc/<tgid>/task'. Other entries(eg. fd, stat) under '/proc/<tgid>'
1935 * can be released by invalidating '/proc/<tgid>' dentry.
1936 * In theory, dentries under '/proc/<tgid>/task' can also be released by
1937 * invalidating '/proc/<tgid>' dentry, we reserve it to handle single
1938 * thread exiting situation: Any one of threads should invalidate its
1939 * '/proc/<tgid>/task/<pid>' dentry before released.
1940 */
1941static struct inode *proc_pid_make_base_inode(struct super_block *sb,
1942 struct task_struct *task, umode_t mode)
1943{
1944 struct inode *inode;
1945 struct proc_inode *ei;
1946 struct pid *pid;
1947
1948 inode = proc_pid_make_inode(sb, task, mode);
1949 if (!inode)
1950 return NULL;
1951
1952 /* Let proc_flush_pid find this directory inode */
1953 ei = PROC_I(inode);
1954 pid = ei->pid;
1955 spin_lock(&pid->lock);
1956 hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes);
1957 spin_unlock(&pid->lock);
1958
1959 return inode;
1960}
1961
1962int pid_getattr(struct user_namespace *mnt_userns, const struct path *path,
1963 struct kstat *stat, u32 request_mask, unsigned int query_flags)
1964{
1965 struct inode *inode = d_inode(path->dentry);
1966 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
1967 struct task_struct *task;
1968
1969 generic_fillattr(&init_user_ns, inode, stat);
1970
1971 stat->uid = GLOBAL_ROOT_UID;
1972 stat->gid = GLOBAL_ROOT_GID;
1973 rcu_read_lock();
1974 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1975 if (task) {
1976 if (!has_pid_permissions(fs_info, task, HIDEPID_INVISIBLE)) {
1977 rcu_read_unlock();
1978 /*
1979 * This doesn't prevent learning whether PID exists,
1980 * it only makes getattr() consistent with readdir().
1981 */
1982 return -ENOENT;
1983 }
1984 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1985 }
1986 rcu_read_unlock();
1987 return 0;
1988}
1989
1990/* dentry stuff */
1991
1992/*
1993 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
1994 */
1995void pid_update_inode(struct task_struct *task, struct inode *inode)
1996{
1997 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1998
1999 inode->i_mode &= ~(S_ISUID | S_ISGID);
2000 security_task_to_inode(task, inode);
2001}
2002
2003/*
2004 * Rewrite the inode's ownerships here because the owning task may have
2005 * performed a setuid(), etc.
2006 *
2007 */
2008static int pid_revalidate(struct dentry *dentry, unsigned int flags)
2009{
2010 struct inode *inode;
2011 struct task_struct *task;
2012 int ret = 0;
2013
2014 rcu_read_lock();
2015 inode = d_inode_rcu(dentry);
2016 if (!inode)
2017 goto out;
2018 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2019
2020 if (task) {
2021 pid_update_inode(task, inode);
2022 ret = 1;
2023 }
2024out:
2025 rcu_read_unlock();
2026 return ret;
2027}
2028
2029static inline bool proc_inode_is_dead(struct inode *inode)
2030{
2031 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
2032}
2033
2034int pid_delete_dentry(const struct dentry *dentry)
2035{
2036 /* Is the task we represent dead?
2037 * If so, then don't put the dentry on the lru list,
2038 * kill it immediately.
2039 */
2040 return proc_inode_is_dead(d_inode(dentry));
2041}
2042
2043const struct dentry_operations pid_dentry_operations =
2044{
2045 .d_revalidate = pid_revalidate,
2046 .d_delete = pid_delete_dentry,
2047};
2048
2049/* Lookups */
2050
2051/*
2052 * Fill a directory entry.
2053 *
2054 * If possible create the dcache entry and derive our inode number and
2055 * file type from dcache entry.
2056 *
2057 * Since all of the proc inode numbers are dynamically generated, the inode
2058 * numbers do not exist until the inode is cache. This means creating
2059 * the dcache entry in readdir is necessary to keep the inode numbers
2060 * reported by readdir in sync with the inode numbers reported
2061 * by stat.
2062 */
2063bool proc_fill_cache(struct file *file, struct dir_context *ctx,
2064 const char *name, unsigned int len,
2065 instantiate_t instantiate, struct task_struct *task, const void *ptr)
2066{
2067 struct dentry *child, *dir = file->f_path.dentry;
2068 struct qstr qname = QSTR_INIT(name, len);
2069 struct inode *inode;
2070 unsigned type = DT_UNKNOWN;
2071 ino_t ino = 1;
2072
2073 child = d_hash_and_lookup(dir, &qname);
2074 if (!child) {
2075 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
2076 child = d_alloc_parallel(dir, &qname, &wq);
2077 if (IS_ERR(child))
2078 goto end_instantiate;
2079 if (d_in_lookup(child)) {
2080 struct dentry *res;
2081 res = instantiate(child, task, ptr);
2082 d_lookup_done(child);
2083 if (unlikely(res)) {
2084 dput(child);
2085 child = res;
2086 if (IS_ERR(child))
2087 goto end_instantiate;
2088 }
2089 }
2090 }
2091 inode = d_inode(child);
2092 ino = inode->i_ino;
2093 type = inode->i_mode >> 12;
2094 dput(child);
2095end_instantiate:
2096 return dir_emit(ctx, name, len, ino, type);
2097}
2098
2099/*
2100 * dname_to_vma_addr - maps a dentry name into two unsigned longs
2101 * which represent vma start and end addresses.
2102 */
2103static int dname_to_vma_addr(struct dentry *dentry,
2104 unsigned long *start, unsigned long *end)
2105{
2106 const char *str = dentry->d_name.name;
2107 unsigned long long sval, eval;
2108 unsigned int len;
2109
2110 if (str[0] == '0' && str[1] != '-')
2111 return -EINVAL;
2112 len = _parse_integer(str, 16, &sval);
2113 if (len & KSTRTOX_OVERFLOW)
2114 return -EINVAL;
2115 if (sval != (unsigned long)sval)
2116 return -EINVAL;
2117 str += len;
2118
2119 if (*str != '-')
2120 return -EINVAL;
2121 str++;
2122
2123 if (str[0] == '0' && str[1])
2124 return -EINVAL;
2125 len = _parse_integer(str, 16, &eval);
2126 if (len & KSTRTOX_OVERFLOW)
2127 return -EINVAL;
2128 if (eval != (unsigned long)eval)
2129 return -EINVAL;
2130 str += len;
2131
2132 if (*str != '\0')
2133 return -EINVAL;
2134
2135 *start = sval;
2136 *end = eval;
2137
2138 return 0;
2139}
2140
2141static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
2142{
2143 unsigned long vm_start, vm_end;
2144 bool exact_vma_exists = false;
2145 struct mm_struct *mm = NULL;
2146 struct task_struct *task;
2147 struct inode *inode;
2148 int status = 0;
2149
2150 if (flags & LOOKUP_RCU)
2151 return -ECHILD;
2152
2153 inode = d_inode(dentry);
2154 task = get_proc_task(inode);
2155 if (!task)
2156 goto out_notask;
2157
2158 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
2159 if (IS_ERR_OR_NULL(mm))
2160 goto out;
2161
2162 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2163 status = mmap_read_lock_killable(mm);
2164 if (!status) {
2165 exact_vma_exists = !!find_exact_vma(mm, vm_start,
2166 vm_end);
2167 mmap_read_unlock(mm);
2168 }
2169 }
2170
2171 mmput(mm);
2172
2173 if (exact_vma_exists) {
2174 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
2175
2176 security_task_to_inode(task, inode);
2177 status = 1;
2178 }
2179
2180out:
2181 put_task_struct(task);
2182
2183out_notask:
2184 return status;
2185}
2186
2187static const struct dentry_operations tid_map_files_dentry_operations = {
2188 .d_revalidate = map_files_d_revalidate,
2189 .d_delete = pid_delete_dentry,
2190};
2191
2192static int map_files_get_link(struct dentry *dentry, struct path *path)
2193{
2194 unsigned long vm_start, vm_end;
2195 struct vm_area_struct *vma;
2196 struct task_struct *task;
2197 struct mm_struct *mm;
2198 int rc;
2199
2200 rc = -ENOENT;
2201 task = get_proc_task(d_inode(dentry));
2202 if (!task)
2203 goto out;
2204
2205 mm = get_task_mm(task);
2206 put_task_struct(task);
2207 if (!mm)
2208 goto out;
2209
2210 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2211 if (rc)
2212 goto out_mmput;
2213
2214 rc = mmap_read_lock_killable(mm);
2215 if (rc)
2216 goto out_mmput;
2217
2218 rc = -ENOENT;
2219 vma = find_exact_vma(mm, vm_start, vm_end);
2220 if (vma && vma->vm_file) {
2221 *path = vma->vm_file->f_path;
2222 path_get(path);
2223 rc = 0;
2224 }
2225 mmap_read_unlock(mm);
2226
2227out_mmput:
2228 mmput(mm);
2229out:
2230 return rc;
2231}
2232
2233struct map_files_info {
2234 unsigned long start;
2235 unsigned long end;
2236 fmode_t mode;
2237};
2238
2239/*
2240 * Only allow CAP_SYS_ADMIN and CAP_CHECKPOINT_RESTORE to follow the links, due
2241 * to concerns about how the symlinks may be used to bypass permissions on
2242 * ancestor directories in the path to the file in question.
2243 */
2244static const char *
2245proc_map_files_get_link(struct dentry *dentry,
2246 struct inode *inode,
2247 struct delayed_call *done)
2248{
2249 if (!checkpoint_restore_ns_capable(&init_user_ns))
2250 return ERR_PTR(-EPERM);
2251
2252 return proc_pid_get_link(dentry, inode, done);
2253}
2254
2255/*
2256 * Identical to proc_pid_link_inode_operations except for get_link()
2257 */
2258static const struct inode_operations proc_map_files_link_inode_operations = {
2259 .readlink = proc_pid_readlink,
2260 .get_link = proc_map_files_get_link,
2261 .setattr = proc_setattr,
2262};
2263
2264static struct dentry *
2265proc_map_files_instantiate(struct dentry *dentry,
2266 struct task_struct *task, const void *ptr)
2267{
2268 fmode_t mode = (fmode_t)(unsigned long)ptr;
2269 struct proc_inode *ei;
2270 struct inode *inode;
2271
2272 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
2273 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2274 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2275 if (!inode)
2276 return ERR_PTR(-ENOENT);
2277
2278 ei = PROC_I(inode);
2279 ei->op.proc_get_link = map_files_get_link;
2280
2281 inode->i_op = &proc_map_files_link_inode_operations;
2282 inode->i_size = 64;
2283
2284 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2285 return d_splice_alias(inode, dentry);
2286}
2287
2288static struct dentry *proc_map_files_lookup(struct inode *dir,
2289 struct dentry *dentry, unsigned int flags)
2290{
2291 unsigned long vm_start, vm_end;
2292 struct vm_area_struct *vma;
2293 struct task_struct *task;
2294 struct dentry *result;
2295 struct mm_struct *mm;
2296
2297 result = ERR_PTR(-ENOENT);
2298 task = get_proc_task(dir);
2299 if (!task)
2300 goto out;
2301
2302 result = ERR_PTR(-EACCES);
2303 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2304 goto out_put_task;
2305
2306 result = ERR_PTR(-ENOENT);
2307 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2308 goto out_put_task;
2309
2310 mm = get_task_mm(task);
2311 if (!mm)
2312 goto out_put_task;
2313
2314 result = ERR_PTR(-EINTR);
2315 if (mmap_read_lock_killable(mm))
2316 goto out_put_mm;
2317
2318 result = ERR_PTR(-ENOENT);
2319 vma = find_exact_vma(mm, vm_start, vm_end);
2320 if (!vma)
2321 goto out_no_vma;
2322
2323 if (vma->vm_file)
2324 result = proc_map_files_instantiate(dentry, task,
2325 (void *)(unsigned long)vma->vm_file->f_mode);
2326
2327out_no_vma:
2328 mmap_read_unlock(mm);
2329out_put_mm:
2330 mmput(mm);
2331out_put_task:
2332 put_task_struct(task);
2333out:
2334 return result;
2335}
2336
2337static const struct inode_operations proc_map_files_inode_operations = {
2338 .lookup = proc_map_files_lookup,
2339 .permission = proc_fd_permission,
2340 .setattr = proc_setattr,
2341};
2342
2343static int
2344proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2345{
2346 struct vm_area_struct *vma;
2347 struct task_struct *task;
2348 struct mm_struct *mm;
2349 unsigned long nr_files, pos, i;
2350 GENRADIX(struct map_files_info) fa;
2351 struct map_files_info *p;
2352 int ret;
2353 struct vma_iterator vmi;
2354
2355 genradix_init(&fa);
2356
2357 ret = -ENOENT;
2358 task = get_proc_task(file_inode(file));
2359 if (!task)
2360 goto out;
2361
2362 ret = -EACCES;
2363 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2364 goto out_put_task;
2365
2366 ret = 0;
2367 if (!dir_emit_dots(file, ctx))
2368 goto out_put_task;
2369
2370 mm = get_task_mm(task);
2371 if (!mm)
2372 goto out_put_task;
2373
2374 ret = mmap_read_lock_killable(mm);
2375 if (ret) {
2376 mmput(mm);
2377 goto out_put_task;
2378 }
2379
2380 nr_files = 0;
2381
2382 /*
2383 * We need two passes here:
2384 *
2385 * 1) Collect vmas of mapped files with mmap_lock taken
2386 * 2) Release mmap_lock and instantiate entries
2387 *
2388 * otherwise we get lockdep complained, since filldir()
2389 * routine might require mmap_lock taken in might_fault().
2390 */
2391
2392 pos = 2;
2393 vma_iter_init(&vmi, mm, 0);
2394 for_each_vma(vmi, vma) {
2395 if (!vma->vm_file)
2396 continue;
2397 if (++pos <= ctx->pos)
2398 continue;
2399
2400 p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
2401 if (!p) {
2402 ret = -ENOMEM;
2403 mmap_read_unlock(mm);
2404 mmput(mm);
2405 goto out_put_task;
2406 }
2407
2408 p->start = vma->vm_start;
2409 p->end = vma->vm_end;
2410 p->mode = vma->vm_file->f_mode;
2411 }
2412 mmap_read_unlock(mm);
2413 mmput(mm);
2414
2415 for (i = 0; i < nr_files; i++) {
2416 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2417 unsigned int len;
2418
2419 p = genradix_ptr(&fa, i);
2420 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2421 if (!proc_fill_cache(file, ctx,
2422 buf, len,
2423 proc_map_files_instantiate,
2424 task,
2425 (void *)(unsigned long)p->mode))
2426 break;
2427 ctx->pos++;
2428 }
2429
2430out_put_task:
2431 put_task_struct(task);
2432out:
2433 genradix_free(&fa);
2434 return ret;
2435}
2436
2437static const struct file_operations proc_map_files_operations = {
2438 .read = generic_read_dir,
2439 .iterate_shared = proc_map_files_readdir,
2440 .llseek = generic_file_llseek,
2441};
2442
2443#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2444struct timers_private {
2445 struct pid *pid;
2446 struct task_struct *task;
2447 struct sighand_struct *sighand;
2448 struct pid_namespace *ns;
2449 unsigned long flags;
2450};
2451
2452static void *timers_start(struct seq_file *m, loff_t *pos)
2453{
2454 struct timers_private *tp = m->private;
2455
2456 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2457 if (!tp->task)
2458 return ERR_PTR(-ESRCH);
2459
2460 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2461 if (!tp->sighand)
2462 return ERR_PTR(-ESRCH);
2463
2464 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2465}
2466
2467static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2468{
2469 struct timers_private *tp = m->private;
2470 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2471}
2472
2473static void timers_stop(struct seq_file *m, void *v)
2474{
2475 struct timers_private *tp = m->private;
2476
2477 if (tp->sighand) {
2478 unlock_task_sighand(tp->task, &tp->flags);
2479 tp->sighand = NULL;
2480 }
2481
2482 if (tp->task) {
2483 put_task_struct(tp->task);
2484 tp->task = NULL;
2485 }
2486}
2487
2488static int show_timer(struct seq_file *m, void *v)
2489{
2490 struct k_itimer *timer;
2491 struct timers_private *tp = m->private;
2492 int notify;
2493 static const char * const nstr[] = {
2494 [SIGEV_SIGNAL] = "signal",
2495 [SIGEV_NONE] = "none",
2496 [SIGEV_THREAD] = "thread",
2497 };
2498
2499 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2500 notify = timer->it_sigev_notify;
2501
2502 seq_printf(m, "ID: %d\n", timer->it_id);
2503 seq_printf(m, "signal: %d/%px\n",
2504 timer->sigq->info.si_signo,
2505 timer->sigq->info.si_value.sival_ptr);
2506 seq_printf(m, "notify: %s/%s.%d\n",
2507 nstr[notify & ~SIGEV_THREAD_ID],
2508 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2509 pid_nr_ns(timer->it_pid, tp->ns));
2510 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2511
2512 return 0;
2513}
2514
2515static const struct seq_operations proc_timers_seq_ops = {
2516 .start = timers_start,
2517 .next = timers_next,
2518 .stop = timers_stop,
2519 .show = show_timer,
2520};
2521
2522static int proc_timers_open(struct inode *inode, struct file *file)
2523{
2524 struct timers_private *tp;
2525
2526 tp = __seq_open_private(file, &proc_timers_seq_ops,
2527 sizeof(struct timers_private));
2528 if (!tp)
2529 return -ENOMEM;
2530
2531 tp->pid = proc_pid(inode);
2532 tp->ns = proc_pid_ns(inode->i_sb);
2533 return 0;
2534}
2535
2536static const struct file_operations proc_timers_operations = {
2537 .open = proc_timers_open,
2538 .read = seq_read,
2539 .llseek = seq_lseek,
2540 .release = seq_release_private,
2541};
2542#endif
2543
2544static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2545 size_t count, loff_t *offset)
2546{
2547 struct inode *inode = file_inode(file);
2548 struct task_struct *p;
2549 u64 slack_ns;
2550 int err;
2551
2552 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2553 if (err < 0)
2554 return err;
2555
2556 p = get_proc_task(inode);
2557 if (!p)
2558 return -ESRCH;
2559
2560 if (p != current) {
2561 rcu_read_lock();
2562 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2563 rcu_read_unlock();
2564 count = -EPERM;
2565 goto out;
2566 }
2567 rcu_read_unlock();
2568
2569 err = security_task_setscheduler(p);
2570 if (err) {
2571 count = err;
2572 goto out;
2573 }
2574 }
2575
2576 task_lock(p);
2577 if (slack_ns == 0)
2578 p->timer_slack_ns = p->default_timer_slack_ns;
2579 else
2580 p->timer_slack_ns = slack_ns;
2581 task_unlock(p);
2582
2583out:
2584 put_task_struct(p);
2585
2586 return count;
2587}
2588
2589static int timerslack_ns_show(struct seq_file *m, void *v)
2590{
2591 struct inode *inode = m->private;
2592 struct task_struct *p;
2593 int err = 0;
2594
2595 p = get_proc_task(inode);
2596 if (!p)
2597 return -ESRCH;
2598
2599 if (p != current) {
2600 rcu_read_lock();
2601 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2602 rcu_read_unlock();
2603 err = -EPERM;
2604 goto out;
2605 }
2606 rcu_read_unlock();
2607
2608 err = security_task_getscheduler(p);
2609 if (err)
2610 goto out;
2611 }
2612
2613 task_lock(p);
2614 seq_printf(m, "%llu\n", p->timer_slack_ns);
2615 task_unlock(p);
2616
2617out:
2618 put_task_struct(p);
2619
2620 return err;
2621}
2622
2623static int timerslack_ns_open(struct inode *inode, struct file *filp)
2624{
2625 return single_open(filp, timerslack_ns_show, inode);
2626}
2627
2628static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2629 .open = timerslack_ns_open,
2630 .read = seq_read,
2631 .write = timerslack_ns_write,
2632 .llseek = seq_lseek,
2633 .release = single_release,
2634};
2635
2636static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2637 struct task_struct *task, const void *ptr)
2638{
2639 const struct pid_entry *p = ptr;
2640 struct inode *inode;
2641 struct proc_inode *ei;
2642
2643 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
2644 if (!inode)
2645 return ERR_PTR(-ENOENT);
2646
2647 ei = PROC_I(inode);
2648 if (S_ISDIR(inode->i_mode))
2649 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2650 if (p->iop)
2651 inode->i_op = p->iop;
2652 if (p->fop)
2653 inode->i_fop = p->fop;
2654 ei->op = p->op;
2655 pid_update_inode(task, inode);
2656 d_set_d_op(dentry, &pid_dentry_operations);
2657 return d_splice_alias(inode, dentry);
2658}
2659
2660static struct dentry *proc_pident_lookup(struct inode *dir,
2661 struct dentry *dentry,
2662 const struct pid_entry *p,
2663 const struct pid_entry *end)
2664{
2665 struct task_struct *task = get_proc_task(dir);
2666 struct dentry *res = ERR_PTR(-ENOENT);
2667
2668 if (!task)
2669 goto out_no_task;
2670
2671 /*
2672 * Yes, it does not scale. And it should not. Don't add
2673 * new entries into /proc/<tgid>/ without very good reasons.
2674 */
2675 for (; p < end; p++) {
2676 if (p->len != dentry->d_name.len)
2677 continue;
2678 if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2679 res = proc_pident_instantiate(dentry, task, p);
2680 break;
2681 }
2682 }
2683 put_task_struct(task);
2684out_no_task:
2685 return res;
2686}
2687
2688static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2689 const struct pid_entry *ents, unsigned int nents)
2690{
2691 struct task_struct *task = get_proc_task(file_inode(file));
2692 const struct pid_entry *p;
2693
2694 if (!task)
2695 return -ENOENT;
2696
2697 if (!dir_emit_dots(file, ctx))
2698 goto out;
2699
2700 if (ctx->pos >= nents + 2)
2701 goto out;
2702
2703 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2704 if (!proc_fill_cache(file, ctx, p->name, p->len,
2705 proc_pident_instantiate, task, p))
2706 break;
2707 ctx->pos++;
2708 }
2709out:
2710 put_task_struct(task);
2711 return 0;
2712}
2713
2714#ifdef CONFIG_SECURITY
2715static int proc_pid_attr_open(struct inode *inode, struct file *file)
2716{
2717 file->private_data = NULL;
2718 __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
2719 return 0;
2720}
2721
2722static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2723 size_t count, loff_t *ppos)
2724{
2725 struct inode * inode = file_inode(file);
2726 char *p = NULL;
2727 ssize_t length;
2728 struct task_struct *task = get_proc_task(inode);
2729
2730 if (!task)
2731 return -ESRCH;
2732
2733 length = security_getprocattr(task, PROC_I(inode)->op.lsm,
2734 file->f_path.dentry->d_name.name,
2735 &p);
2736 put_task_struct(task);
2737 if (length > 0)
2738 length = simple_read_from_buffer(buf, count, ppos, p, length);
2739 kfree(p);
2740 return length;
2741}
2742
2743static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2744 size_t count, loff_t *ppos)
2745{
2746 struct inode * inode = file_inode(file);
2747 struct task_struct *task;
2748 void *page;
2749 int rv;
2750
2751 /* A task may only write when it was the opener. */
2752 if (file->private_data != current->mm)
2753 return -EPERM;
2754
2755 rcu_read_lock();
2756 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2757 if (!task) {
2758 rcu_read_unlock();
2759 return -ESRCH;
2760 }
2761 /* A task may only write its own attributes. */
2762 if (current != task) {
2763 rcu_read_unlock();
2764 return -EACCES;
2765 }
2766 /* Prevent changes to overridden credentials. */
2767 if (current_cred() != current_real_cred()) {
2768 rcu_read_unlock();
2769 return -EBUSY;
2770 }
2771 rcu_read_unlock();
2772
2773 if (count > PAGE_SIZE)
2774 count = PAGE_SIZE;
2775
2776 /* No partial writes. */
2777 if (*ppos != 0)
2778 return -EINVAL;
2779
2780 page = memdup_user(buf, count);
2781 if (IS_ERR(page)) {
2782 rv = PTR_ERR(page);
2783 goto out;
2784 }
2785
2786 /* Guard against adverse ptrace interaction */
2787 rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex);
2788 if (rv < 0)
2789 goto out_free;
2790
2791 rv = security_setprocattr(PROC_I(inode)->op.lsm,
2792 file->f_path.dentry->d_name.name, page,
2793 count);
2794 mutex_unlock(¤t->signal->cred_guard_mutex);
2795out_free:
2796 kfree(page);
2797out:
2798 return rv;
2799}
2800
2801static const struct file_operations proc_pid_attr_operations = {
2802 .open = proc_pid_attr_open,
2803 .read = proc_pid_attr_read,
2804 .write = proc_pid_attr_write,
2805 .llseek = generic_file_llseek,
2806 .release = mem_release,
2807};
2808
2809#define LSM_DIR_OPS(LSM) \
2810static int proc_##LSM##_attr_dir_iterate(struct file *filp, \
2811 struct dir_context *ctx) \
2812{ \
2813 return proc_pident_readdir(filp, ctx, \
2814 LSM##_attr_dir_stuff, \
2815 ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2816} \
2817\
2818static const struct file_operations proc_##LSM##_attr_dir_ops = { \
2819 .read = generic_read_dir, \
2820 .iterate = proc_##LSM##_attr_dir_iterate, \
2821 .llseek = default_llseek, \
2822}; \
2823\
2824static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
2825 struct dentry *dentry, unsigned int flags) \
2826{ \
2827 return proc_pident_lookup(dir, dentry, \
2828 LSM##_attr_dir_stuff, \
2829 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2830} \
2831\
2832static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
2833 .lookup = proc_##LSM##_attr_dir_lookup, \
2834 .getattr = pid_getattr, \
2835 .setattr = proc_setattr, \
2836}
2837
2838#ifdef CONFIG_SECURITY_SMACK
2839static const struct pid_entry smack_attr_dir_stuff[] = {
2840 ATTR("smack", "current", 0666),
2841};
2842LSM_DIR_OPS(smack);
2843#endif
2844
2845#ifdef CONFIG_SECURITY_APPARMOR
2846static const struct pid_entry apparmor_attr_dir_stuff[] = {
2847 ATTR("apparmor", "current", 0666),
2848 ATTR("apparmor", "prev", 0444),
2849 ATTR("apparmor", "exec", 0666),
2850};
2851LSM_DIR_OPS(apparmor);
2852#endif
2853
2854static const struct pid_entry attr_dir_stuff[] = {
2855 ATTR(NULL, "current", 0666),
2856 ATTR(NULL, "prev", 0444),
2857 ATTR(NULL, "exec", 0666),
2858 ATTR(NULL, "fscreate", 0666),
2859 ATTR(NULL, "keycreate", 0666),
2860 ATTR(NULL, "sockcreate", 0666),
2861#ifdef CONFIG_SECURITY_SMACK
2862 DIR("smack", 0555,
2863 proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
2864#endif
2865#ifdef CONFIG_SECURITY_APPARMOR
2866 DIR("apparmor", 0555,
2867 proc_apparmor_attr_dir_inode_ops, proc_apparmor_attr_dir_ops),
2868#endif
2869};
2870
2871static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2872{
2873 return proc_pident_readdir(file, ctx,
2874 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2875}
2876
2877static const struct file_operations proc_attr_dir_operations = {
2878 .read = generic_read_dir,
2879 .iterate_shared = proc_attr_dir_readdir,
2880 .llseek = generic_file_llseek,
2881};
2882
2883static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2884 struct dentry *dentry, unsigned int flags)
2885{
2886 return proc_pident_lookup(dir, dentry,
2887 attr_dir_stuff,
2888 attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
2889}
2890
2891static const struct inode_operations proc_attr_dir_inode_operations = {
2892 .lookup = proc_attr_dir_lookup,
2893 .getattr = pid_getattr,
2894 .setattr = proc_setattr,
2895};
2896
2897#endif
2898
2899#ifdef CONFIG_ELF_CORE
2900static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2901 size_t count, loff_t *ppos)
2902{
2903 struct task_struct *task = get_proc_task(file_inode(file));
2904 struct mm_struct *mm;
2905 char buffer[PROC_NUMBUF];
2906 size_t len;
2907 int ret;
2908
2909 if (!task)
2910 return -ESRCH;
2911
2912 ret = 0;
2913 mm = get_task_mm(task);
2914 if (mm) {
2915 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2916 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2917 MMF_DUMP_FILTER_SHIFT));
2918 mmput(mm);
2919 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2920 }
2921
2922 put_task_struct(task);
2923
2924 return ret;
2925}
2926
2927static ssize_t proc_coredump_filter_write(struct file *file,
2928 const char __user *buf,
2929 size_t count,
2930 loff_t *ppos)
2931{
2932 struct task_struct *task;
2933 struct mm_struct *mm;
2934 unsigned int val;
2935 int ret;
2936 int i;
2937 unsigned long mask;
2938
2939 ret = kstrtouint_from_user(buf, count, 0, &val);
2940 if (ret < 0)
2941 return ret;
2942
2943 ret = -ESRCH;
2944 task = get_proc_task(file_inode(file));
2945 if (!task)
2946 goto out_no_task;
2947
2948 mm = get_task_mm(task);
2949 if (!mm)
2950 goto out_no_mm;
2951 ret = 0;
2952
2953 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2954 if (val & mask)
2955 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2956 else
2957 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2958 }
2959
2960 mmput(mm);
2961 out_no_mm:
2962 put_task_struct(task);
2963 out_no_task:
2964 if (ret < 0)
2965 return ret;
2966 return count;
2967}
2968
2969static const struct file_operations proc_coredump_filter_operations = {
2970 .read = proc_coredump_filter_read,
2971 .write = proc_coredump_filter_write,
2972 .llseek = generic_file_llseek,
2973};
2974#endif
2975
2976#ifdef CONFIG_TASK_IO_ACCOUNTING
2977static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2978{
2979 struct task_io_accounting acct = task->ioac;
2980 unsigned long flags;
2981 int result;
2982
2983 result = down_read_killable(&task->signal->exec_update_lock);
2984 if (result)
2985 return result;
2986
2987 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2988 result = -EACCES;
2989 goto out_unlock;
2990 }
2991
2992 if (whole && lock_task_sighand(task, &flags)) {
2993 struct task_struct *t = task;
2994
2995 task_io_accounting_add(&acct, &task->signal->ioac);
2996 while_each_thread(task, t)
2997 task_io_accounting_add(&acct, &t->ioac);
2998
2999 unlock_task_sighand(task, &flags);
3000 }
3001 seq_printf(m,
3002 "rchar: %llu\n"
3003 "wchar: %llu\n"
3004 "syscr: %llu\n"
3005 "syscw: %llu\n"
3006 "read_bytes: %llu\n"
3007 "write_bytes: %llu\n"
3008 "cancelled_write_bytes: %llu\n",
3009 (unsigned long long)acct.rchar,
3010 (unsigned long long)acct.wchar,
3011 (unsigned long long)acct.syscr,
3012 (unsigned long long)acct.syscw,
3013 (unsigned long long)acct.read_bytes,
3014 (unsigned long long)acct.write_bytes,
3015 (unsigned long long)acct.cancelled_write_bytes);
3016 result = 0;
3017
3018out_unlock:
3019 up_read(&task->signal->exec_update_lock);
3020 return result;
3021}
3022
3023static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
3024 struct pid *pid, struct task_struct *task)
3025{
3026 return do_io_accounting(task, m, 0);
3027}
3028
3029static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
3030 struct pid *pid, struct task_struct *task)
3031{
3032 return do_io_accounting(task, m, 1);
3033}
3034#endif /* CONFIG_TASK_IO_ACCOUNTING */
3035
3036#ifdef CONFIG_USER_NS
3037static int proc_id_map_open(struct inode *inode, struct file *file,
3038 const struct seq_operations *seq_ops)
3039{
3040 struct user_namespace *ns = NULL;
3041 struct task_struct *task;
3042 struct seq_file *seq;
3043 int ret = -EINVAL;
3044
3045 task = get_proc_task(inode);
3046 if (task) {
3047 rcu_read_lock();
3048 ns = get_user_ns(task_cred_xxx(task, user_ns));
3049 rcu_read_unlock();
3050 put_task_struct(task);
3051 }
3052 if (!ns)
3053 goto err;
3054
3055 ret = seq_open(file, seq_ops);
3056 if (ret)
3057 goto err_put_ns;
3058
3059 seq = file->private_data;
3060 seq->private = ns;
3061
3062 return 0;
3063err_put_ns:
3064 put_user_ns(ns);
3065err:
3066 return ret;
3067}
3068
3069static int proc_id_map_release(struct inode *inode, struct file *file)
3070{
3071 struct seq_file *seq = file->private_data;
3072 struct user_namespace *ns = seq->private;
3073 put_user_ns(ns);
3074 return seq_release(inode, file);
3075}
3076
3077static int proc_uid_map_open(struct inode *inode, struct file *file)
3078{
3079 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
3080}
3081
3082static int proc_gid_map_open(struct inode *inode, struct file *file)
3083{
3084 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
3085}
3086
3087static int proc_projid_map_open(struct inode *inode, struct file *file)
3088{
3089 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
3090}
3091
3092static const struct file_operations proc_uid_map_operations = {
3093 .open = proc_uid_map_open,
3094 .write = proc_uid_map_write,
3095 .read = seq_read,
3096 .llseek = seq_lseek,
3097 .release = proc_id_map_release,
3098};
3099
3100static const struct file_operations proc_gid_map_operations = {
3101 .open = proc_gid_map_open,
3102 .write = proc_gid_map_write,
3103 .read = seq_read,
3104 .llseek = seq_lseek,
3105 .release = proc_id_map_release,
3106};
3107
3108static const struct file_operations proc_projid_map_operations = {
3109 .open = proc_projid_map_open,
3110 .write = proc_projid_map_write,
3111 .read = seq_read,
3112 .llseek = seq_lseek,
3113 .release = proc_id_map_release,
3114};
3115
3116static int proc_setgroups_open(struct inode *inode, struct file *file)
3117{
3118 struct user_namespace *ns = NULL;
3119 struct task_struct *task;
3120 int ret;
3121
3122 ret = -ESRCH;
3123 task = get_proc_task(inode);
3124 if (task) {
3125 rcu_read_lock();
3126 ns = get_user_ns(task_cred_xxx(task, user_ns));
3127 rcu_read_unlock();
3128 put_task_struct(task);
3129 }
3130 if (!ns)
3131 goto err;
3132
3133 if (file->f_mode & FMODE_WRITE) {
3134 ret = -EACCES;
3135 if (!ns_capable(ns, CAP_SYS_ADMIN))
3136 goto err_put_ns;
3137 }
3138
3139 ret = single_open(file, &proc_setgroups_show, ns);
3140 if (ret)
3141 goto err_put_ns;
3142
3143 return 0;
3144err_put_ns:
3145 put_user_ns(ns);
3146err:
3147 return ret;
3148}
3149
3150static int proc_setgroups_release(struct inode *inode, struct file *file)
3151{
3152 struct seq_file *seq = file->private_data;
3153 struct user_namespace *ns = seq->private;
3154 int ret = single_release(inode, file);
3155 put_user_ns(ns);
3156 return ret;
3157}
3158
3159static const struct file_operations proc_setgroups_operations = {
3160 .open = proc_setgroups_open,
3161 .write = proc_setgroups_write,
3162 .read = seq_read,
3163 .llseek = seq_lseek,
3164 .release = proc_setgroups_release,
3165};
3166#endif /* CONFIG_USER_NS */
3167
3168static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
3169 struct pid *pid, struct task_struct *task)
3170{
3171 int err = lock_trace(task);
3172 if (!err) {
3173 seq_printf(m, "%08x\n", task->personality);
3174 unlock_trace(task);
3175 }
3176 return err;
3177}
3178
3179#ifdef CONFIG_LIVEPATCH
3180static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
3181 struct pid *pid, struct task_struct *task)
3182{
3183 seq_printf(m, "%d\n", task->patch_state);
3184 return 0;
3185}
3186#endif /* CONFIG_LIVEPATCH */
3187
3188#ifdef CONFIG_KSM
3189static int proc_pid_ksm_merging_pages(struct seq_file *m, struct pid_namespace *ns,
3190 struct pid *pid, struct task_struct *task)
3191{
3192 struct mm_struct *mm;
3193
3194 mm = get_task_mm(task);
3195 if (mm) {
3196 seq_printf(m, "%lu\n", mm->ksm_merging_pages);
3197 mmput(mm);
3198 }
3199
3200 return 0;
3201}
3202static int proc_pid_ksm_stat(struct seq_file *m, struct pid_namespace *ns,
3203 struct pid *pid, struct task_struct *task)
3204{
3205 struct mm_struct *mm;
3206
3207 mm = get_task_mm(task);
3208 if (mm) {
3209 seq_printf(m, "ksm_rmap_items %lu\n", mm->ksm_rmap_items);
3210 mmput(mm);
3211 }
3212
3213 return 0;
3214}
3215#endif /* CONFIG_KSM */
3216
3217#ifdef CONFIG_STACKLEAK_METRICS
3218static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
3219 struct pid *pid, struct task_struct *task)
3220{
3221 unsigned long prev_depth = THREAD_SIZE -
3222 (task->prev_lowest_stack & (THREAD_SIZE - 1));
3223 unsigned long depth = THREAD_SIZE -
3224 (task->lowest_stack & (THREAD_SIZE - 1));
3225
3226 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
3227 prev_depth, depth);
3228 return 0;
3229}
3230#endif /* CONFIG_STACKLEAK_METRICS */
3231
3232/*
3233 * Thread groups
3234 */
3235static const struct file_operations proc_task_operations;
3236static const struct inode_operations proc_task_inode_operations;
3237
3238static const struct pid_entry tgid_base_stuff[] = {
3239 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3240 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3241 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3242 DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3243 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3244#ifdef CONFIG_NET
3245 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3246#endif
3247 REG("environ", S_IRUSR, proc_environ_operations),
3248 REG("auxv", S_IRUSR, proc_auxv_operations),
3249 ONE("status", S_IRUGO, proc_pid_status),
3250 ONE("personality", S_IRUSR, proc_pid_personality),
3251 ONE("limits", S_IRUGO, proc_pid_limits),
3252#ifdef CONFIG_SCHED_DEBUG
3253 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3254#endif
3255#ifdef CONFIG_SCHED_AUTOGROUP
3256 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3257#endif
3258#ifdef CONFIG_TIME_NS
3259 REG("timens_offsets", S_IRUGO|S_IWUSR, proc_timens_offsets_operations),
3260#endif
3261 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3262#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3263 ONE("syscall", S_IRUSR, proc_pid_syscall),
3264#endif
3265 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3266 ONE("stat", S_IRUGO, proc_tgid_stat),
3267 ONE("statm", S_IRUGO, proc_pid_statm),
3268 REG("maps", S_IRUGO, proc_pid_maps_operations),
3269#ifdef CONFIG_NUMA
3270 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3271#endif
3272 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3273 LNK("cwd", proc_cwd_link),
3274 LNK("root", proc_root_link),
3275 LNK("exe", proc_exe_link),
3276 REG("mounts", S_IRUGO, proc_mounts_operations),
3277 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3278 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3279#ifdef CONFIG_PROC_PAGE_MONITOR
3280 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3281 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3282 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3283 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3284#endif
3285#ifdef CONFIG_SECURITY
3286 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3287#endif
3288#ifdef CONFIG_KALLSYMS
3289 ONE("wchan", S_IRUGO, proc_pid_wchan),
3290#endif
3291#ifdef CONFIG_STACKTRACE
3292 ONE("stack", S_IRUSR, proc_pid_stack),
3293#endif
3294#ifdef CONFIG_SCHED_INFO
3295 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3296#endif
3297#ifdef CONFIG_LATENCYTOP
3298 REG("latency", S_IRUGO, proc_lstats_operations),
3299#endif
3300#ifdef CONFIG_PROC_PID_CPUSET
3301 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3302#endif
3303#ifdef CONFIG_CGROUPS
3304 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3305#endif
3306#ifdef CONFIG_PROC_CPU_RESCTRL
3307 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3308#endif
3309 ONE("oom_score", S_IRUGO, proc_oom_score),
3310 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3311 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3312#ifdef CONFIG_AUDIT
3313 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3314 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3315#endif
3316#ifdef CONFIG_FAULT_INJECTION
3317 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3318 REG("fail-nth", 0644, proc_fail_nth_operations),
3319#endif
3320#ifdef CONFIG_ELF_CORE
3321 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3322#endif
3323#ifdef CONFIG_TASK_IO_ACCOUNTING
3324 ONE("io", S_IRUSR, proc_tgid_io_accounting),
3325#endif
3326#ifdef CONFIG_USER_NS
3327 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3328 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3329 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3330 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3331#endif
3332#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3333 REG("timers", S_IRUGO, proc_timers_operations),
3334#endif
3335 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3336#ifdef CONFIG_LIVEPATCH
3337 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3338#endif
3339#ifdef CONFIG_STACKLEAK_METRICS
3340 ONE("stack_depth", S_IRUGO, proc_stack_depth),
3341#endif
3342#ifdef CONFIG_PROC_PID_ARCH_STATUS
3343 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3344#endif
3345#ifdef CONFIG_SECCOMP_CACHE_DEBUG
3346 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3347#endif
3348#ifdef CONFIG_KSM
3349 ONE("ksm_merging_pages", S_IRUSR, proc_pid_ksm_merging_pages),
3350 ONE("ksm_stat", S_IRUSR, proc_pid_ksm_stat),
3351#endif
3352};
3353
3354static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3355{
3356 return proc_pident_readdir(file, ctx,
3357 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3358}
3359
3360static const struct file_operations proc_tgid_base_operations = {
3361 .read = generic_read_dir,
3362 .iterate_shared = proc_tgid_base_readdir,
3363 .llseek = generic_file_llseek,
3364};
3365
3366struct pid *tgid_pidfd_to_pid(const struct file *file)
3367{
3368 if (file->f_op != &proc_tgid_base_operations)
3369 return ERR_PTR(-EBADF);
3370
3371 return proc_pid(file_inode(file));
3372}
3373
3374static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3375{
3376 return proc_pident_lookup(dir, dentry,
3377 tgid_base_stuff,
3378 tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
3379}
3380
3381static const struct inode_operations proc_tgid_base_inode_operations = {
3382 .lookup = proc_tgid_base_lookup,
3383 .getattr = pid_getattr,
3384 .setattr = proc_setattr,
3385 .permission = proc_pid_permission,
3386};
3387
3388/**
3389 * proc_flush_pid - Remove dcache entries for @pid from the /proc dcache.
3390 * @pid: pid that should be flushed.
3391 *
3392 * This function walks a list of inodes (that belong to any proc
3393 * filesystem) that are attached to the pid and flushes them from
3394 * the dentry cache.
3395 *
3396 * It is safe and reasonable to cache /proc entries for a task until
3397 * that task exits. After that they just clog up the dcache with
3398 * useless entries, possibly causing useful dcache entries to be
3399 * flushed instead. This routine is provided to flush those useless
3400 * dcache entries when a process is reaped.
3401 *
3402 * NOTE: This routine is just an optimization so it does not guarantee
3403 * that no dcache entries will exist after a process is reaped
3404 * it just makes it very unlikely that any will persist.
3405 */
3406
3407void proc_flush_pid(struct pid *pid)
3408{
3409 proc_invalidate_siblings_dcache(&pid->inodes, &pid->lock);
3410}
3411
3412static struct dentry *proc_pid_instantiate(struct dentry * dentry,
3413 struct task_struct *task, const void *ptr)
3414{
3415 struct inode *inode;
3416
3417 inode = proc_pid_make_base_inode(dentry->d_sb, task,
3418 S_IFDIR | S_IRUGO | S_IXUGO);
3419 if (!inode)
3420 return ERR_PTR(-ENOENT);
3421
3422 inode->i_op = &proc_tgid_base_inode_operations;
3423 inode->i_fop = &proc_tgid_base_operations;
3424 inode->i_flags|=S_IMMUTABLE;
3425
3426 set_nlink(inode, nlink_tgid);
3427 pid_update_inode(task, inode);
3428
3429 d_set_d_op(dentry, &pid_dentry_operations);
3430 return d_splice_alias(inode, dentry);
3431}
3432
3433struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
3434{
3435 struct task_struct *task;
3436 unsigned tgid;
3437 struct proc_fs_info *fs_info;
3438 struct pid_namespace *ns;
3439 struct dentry *result = ERR_PTR(-ENOENT);
3440
3441 tgid = name_to_int(&dentry->d_name);
3442 if (tgid == ~0U)
3443 goto out;
3444
3445 fs_info = proc_sb_info(dentry->d_sb);
3446 ns = fs_info->pid_ns;
3447 rcu_read_lock();
3448 task = find_task_by_pid_ns(tgid, ns);
3449 if (task)
3450 get_task_struct(task);
3451 rcu_read_unlock();
3452 if (!task)
3453 goto out;
3454
3455 /* Limit procfs to only ptraceable tasks */
3456 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE) {
3457 if (!has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS))
3458 goto out_put_task;
3459 }
3460
3461 result = proc_pid_instantiate(dentry, task, NULL);
3462out_put_task:
3463 put_task_struct(task);
3464out:
3465 return result;
3466}
3467
3468/*
3469 * Find the first task with tgid >= tgid
3470 *
3471 */
3472struct tgid_iter {
3473 unsigned int tgid;
3474 struct task_struct *task;
3475};
3476static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3477{
3478 struct pid *pid;
3479
3480 if (iter.task)
3481 put_task_struct(iter.task);
3482 rcu_read_lock();
3483retry:
3484 iter.task = NULL;
3485 pid = find_ge_pid(iter.tgid, ns);
3486 if (pid) {
3487 iter.tgid = pid_nr_ns(pid, ns);
3488 iter.task = pid_task(pid, PIDTYPE_TGID);
3489 if (!iter.task) {
3490 iter.tgid += 1;
3491 goto retry;
3492 }
3493 get_task_struct(iter.task);
3494 }
3495 rcu_read_unlock();
3496 return iter;
3497}
3498
3499#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3500
3501/* for the /proc/ directory itself, after non-process stuff has been done */
3502int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3503{
3504 struct tgid_iter iter;
3505 struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb);
3506 struct pid_namespace *ns = proc_pid_ns(file_inode(file)->i_sb);
3507 loff_t pos = ctx->pos;
3508
3509 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3510 return 0;
3511
3512 if (pos == TGID_OFFSET - 2) {
3513 struct inode *inode = d_inode(fs_info->proc_self);
3514 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3515 return 0;
3516 ctx->pos = pos = pos + 1;
3517 }
3518 if (pos == TGID_OFFSET - 1) {
3519 struct inode *inode = d_inode(fs_info->proc_thread_self);
3520 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3521 return 0;
3522 ctx->pos = pos = pos + 1;
3523 }
3524 iter.tgid = pos - TGID_OFFSET;
3525 iter.task = NULL;
3526 for (iter = next_tgid(ns, iter);
3527 iter.task;
3528 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3529 char name[10 + 1];
3530 unsigned int len;
3531
3532 cond_resched();
3533 if (!has_pid_permissions(fs_info, iter.task, HIDEPID_INVISIBLE))
3534 continue;
3535
3536 len = snprintf(name, sizeof(name), "%u", iter.tgid);
3537 ctx->pos = iter.tgid + TGID_OFFSET;
3538 if (!proc_fill_cache(file, ctx, name, len,
3539 proc_pid_instantiate, iter.task, NULL)) {
3540 put_task_struct(iter.task);
3541 return 0;
3542 }
3543 }
3544 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3545 return 0;
3546}
3547
3548/*
3549 * proc_tid_comm_permission is a special permission function exclusively
3550 * used for the node /proc/<pid>/task/<tid>/comm.
3551 * It bypasses generic permission checks in the case where a task of the same
3552 * task group attempts to access the node.
3553 * The rationale behind this is that glibc and bionic access this node for
3554 * cross thread naming (pthread_set/getname_np(!self)). However, if
3555 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3556 * which locks out the cross thread naming implementation.
3557 * This function makes sure that the node is always accessible for members of
3558 * same thread group.
3559 */
3560static int proc_tid_comm_permission(struct user_namespace *mnt_userns,
3561 struct inode *inode, int mask)
3562{
3563 bool is_same_tgroup;
3564 struct task_struct *task;
3565
3566 task = get_proc_task(inode);
3567 if (!task)
3568 return -ESRCH;
3569 is_same_tgroup = same_thread_group(current, task);
3570 put_task_struct(task);
3571
3572 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3573 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3574 * read or written by the members of the corresponding
3575 * thread group.
3576 */
3577 return 0;
3578 }
3579
3580 return generic_permission(&init_user_ns, inode, mask);
3581}
3582
3583static const struct inode_operations proc_tid_comm_inode_operations = {
3584 .permission = proc_tid_comm_permission,
3585};
3586
3587/*
3588 * Tasks
3589 */
3590static const struct pid_entry tid_base_stuff[] = {
3591 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3592 DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3593 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3594#ifdef CONFIG_NET
3595 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3596#endif
3597 REG("environ", S_IRUSR, proc_environ_operations),
3598 REG("auxv", S_IRUSR, proc_auxv_operations),
3599 ONE("status", S_IRUGO, proc_pid_status),
3600 ONE("personality", S_IRUSR, proc_pid_personality),
3601 ONE("limits", S_IRUGO, proc_pid_limits),
3602#ifdef CONFIG_SCHED_DEBUG
3603 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3604#endif
3605 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3606 &proc_tid_comm_inode_operations,
3607 &proc_pid_set_comm_operations, {}),
3608#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3609 ONE("syscall", S_IRUSR, proc_pid_syscall),
3610#endif
3611 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3612 ONE("stat", S_IRUGO, proc_tid_stat),
3613 ONE("statm", S_IRUGO, proc_pid_statm),
3614 REG("maps", S_IRUGO, proc_pid_maps_operations),
3615#ifdef CONFIG_PROC_CHILDREN
3616 REG("children", S_IRUGO, proc_tid_children_operations),
3617#endif
3618#ifdef CONFIG_NUMA
3619 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3620#endif
3621 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3622 LNK("cwd", proc_cwd_link),
3623 LNK("root", proc_root_link),
3624 LNK("exe", proc_exe_link),
3625 REG("mounts", S_IRUGO, proc_mounts_operations),
3626 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3627#ifdef CONFIG_PROC_PAGE_MONITOR
3628 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3629 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3630 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3631 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3632#endif
3633#ifdef CONFIG_SECURITY
3634 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3635#endif
3636#ifdef CONFIG_KALLSYMS
3637 ONE("wchan", S_IRUGO, proc_pid_wchan),
3638#endif
3639#ifdef CONFIG_STACKTRACE
3640 ONE("stack", S_IRUSR, proc_pid_stack),
3641#endif
3642#ifdef CONFIG_SCHED_INFO
3643 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3644#endif
3645#ifdef CONFIG_LATENCYTOP
3646 REG("latency", S_IRUGO, proc_lstats_operations),
3647#endif
3648#ifdef CONFIG_PROC_PID_CPUSET
3649 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3650#endif
3651#ifdef CONFIG_CGROUPS
3652 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3653#endif
3654#ifdef CONFIG_PROC_CPU_RESCTRL
3655 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3656#endif
3657 ONE("oom_score", S_IRUGO, proc_oom_score),
3658 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3659 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3660#ifdef CONFIG_AUDIT
3661 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3662 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3663#endif
3664#ifdef CONFIG_FAULT_INJECTION
3665 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3666 REG("fail-nth", 0644, proc_fail_nth_operations),
3667#endif
3668#ifdef CONFIG_TASK_IO_ACCOUNTING
3669 ONE("io", S_IRUSR, proc_tid_io_accounting),
3670#endif
3671#ifdef CONFIG_USER_NS
3672 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3673 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3674 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3675 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3676#endif
3677#ifdef CONFIG_LIVEPATCH
3678 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3679#endif
3680#ifdef CONFIG_PROC_PID_ARCH_STATUS
3681 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3682#endif
3683#ifdef CONFIG_SECCOMP_CACHE_DEBUG
3684 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3685#endif
3686#ifdef CONFIG_KSM
3687 ONE("ksm_merging_pages", S_IRUSR, proc_pid_ksm_merging_pages),
3688 ONE("ksm_stat", S_IRUSR, proc_pid_ksm_stat),
3689#endif
3690};
3691
3692static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3693{
3694 return proc_pident_readdir(file, ctx,
3695 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3696}
3697
3698static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3699{
3700 return proc_pident_lookup(dir, dentry,
3701 tid_base_stuff,
3702 tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
3703}
3704
3705static const struct file_operations proc_tid_base_operations = {
3706 .read = generic_read_dir,
3707 .iterate_shared = proc_tid_base_readdir,
3708 .llseek = generic_file_llseek,
3709};
3710
3711static const struct inode_operations proc_tid_base_inode_operations = {
3712 .lookup = proc_tid_base_lookup,
3713 .getattr = pid_getattr,
3714 .setattr = proc_setattr,
3715};
3716
3717static struct dentry *proc_task_instantiate(struct dentry *dentry,
3718 struct task_struct *task, const void *ptr)
3719{
3720 struct inode *inode;
3721 inode = proc_pid_make_base_inode(dentry->d_sb, task,
3722 S_IFDIR | S_IRUGO | S_IXUGO);
3723 if (!inode)
3724 return ERR_PTR(-ENOENT);
3725
3726 inode->i_op = &proc_tid_base_inode_operations;
3727 inode->i_fop = &proc_tid_base_operations;
3728 inode->i_flags |= S_IMMUTABLE;
3729
3730 set_nlink(inode, nlink_tid);
3731 pid_update_inode(task, inode);
3732
3733 d_set_d_op(dentry, &pid_dentry_operations);
3734 return d_splice_alias(inode, dentry);
3735}
3736
3737static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3738{
3739 struct task_struct *task;
3740 struct task_struct *leader = get_proc_task(dir);
3741 unsigned tid;
3742 struct proc_fs_info *fs_info;
3743 struct pid_namespace *ns;
3744 struct dentry *result = ERR_PTR(-ENOENT);
3745
3746 if (!leader)
3747 goto out_no_task;
3748
3749 tid = name_to_int(&dentry->d_name);
3750 if (tid == ~0U)
3751 goto out;
3752
3753 fs_info = proc_sb_info(dentry->d_sb);
3754 ns = fs_info->pid_ns;
3755 rcu_read_lock();
3756 task = find_task_by_pid_ns(tid, ns);
3757 if (task)
3758 get_task_struct(task);
3759 rcu_read_unlock();
3760 if (!task)
3761 goto out;
3762 if (!same_thread_group(leader, task))
3763 goto out_drop_task;
3764
3765 result = proc_task_instantiate(dentry, task, NULL);
3766out_drop_task:
3767 put_task_struct(task);
3768out:
3769 put_task_struct(leader);
3770out_no_task:
3771 return result;
3772}
3773
3774/*
3775 * Find the first tid of a thread group to return to user space.
3776 *
3777 * Usually this is just the thread group leader, but if the users
3778 * buffer was too small or there was a seek into the middle of the
3779 * directory we have more work todo.
3780 *
3781 * In the case of a short read we start with find_task_by_pid.
3782 *
3783 * In the case of a seek we start with the leader and walk nr
3784 * threads past it.
3785 */
3786static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3787 struct pid_namespace *ns)
3788{
3789 struct task_struct *pos, *task;
3790 unsigned long nr = f_pos;
3791
3792 if (nr != f_pos) /* 32bit overflow? */
3793 return NULL;
3794
3795 rcu_read_lock();
3796 task = pid_task(pid, PIDTYPE_PID);
3797 if (!task)
3798 goto fail;
3799
3800 /* Attempt to start with the tid of a thread */
3801 if (tid && nr) {
3802 pos = find_task_by_pid_ns(tid, ns);
3803 if (pos && same_thread_group(pos, task))
3804 goto found;
3805 }
3806
3807 /* If nr exceeds the number of threads there is nothing todo */
3808 if (nr >= get_nr_threads(task))
3809 goto fail;
3810
3811 /* If we haven't found our starting place yet start
3812 * with the leader and walk nr threads forward.
3813 */
3814 pos = task = task->group_leader;
3815 do {
3816 if (!nr--)
3817 goto found;
3818 } while_each_thread(task, pos);
3819fail:
3820 pos = NULL;
3821 goto out;
3822found:
3823 get_task_struct(pos);
3824out:
3825 rcu_read_unlock();
3826 return pos;
3827}
3828
3829/*
3830 * Find the next thread in the thread list.
3831 * Return NULL if there is an error or no next thread.
3832 *
3833 * The reference to the input task_struct is released.
3834 */
3835static struct task_struct *next_tid(struct task_struct *start)
3836{
3837 struct task_struct *pos = NULL;
3838 rcu_read_lock();
3839 if (pid_alive(start)) {
3840 pos = next_thread(start);
3841 if (thread_group_leader(pos))
3842 pos = NULL;
3843 else
3844 get_task_struct(pos);
3845 }
3846 rcu_read_unlock();
3847 put_task_struct(start);
3848 return pos;
3849}
3850
3851/* for the /proc/TGID/task/ directories */
3852static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3853{
3854 struct inode *inode = file_inode(file);
3855 struct task_struct *task;
3856 struct pid_namespace *ns;
3857 int tid;
3858
3859 if (proc_inode_is_dead(inode))
3860 return -ENOENT;
3861
3862 if (!dir_emit_dots(file, ctx))
3863 return 0;
3864
3865 /* f_version caches the tgid value that the last readdir call couldn't
3866 * return. lseek aka telldir automagically resets f_version to 0.
3867 */
3868 ns = proc_pid_ns(inode->i_sb);
3869 tid = (int)file->f_version;
3870 file->f_version = 0;
3871 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3872 task;
3873 task = next_tid(task), ctx->pos++) {
3874 char name[10 + 1];
3875 unsigned int len;
3876
3877 tid = task_pid_nr_ns(task, ns);
3878 if (!tid)
3879 continue; /* The task has just exited. */
3880 len = snprintf(name, sizeof(name), "%u", tid);
3881 if (!proc_fill_cache(file, ctx, name, len,
3882 proc_task_instantiate, task, NULL)) {
3883 /* returning this tgid failed, save it as the first
3884 * pid for the next readir call */
3885 file->f_version = (u64)tid;
3886 put_task_struct(task);
3887 break;
3888 }
3889 }
3890
3891 return 0;
3892}
3893
3894static int proc_task_getattr(struct user_namespace *mnt_userns,
3895 const struct path *path, struct kstat *stat,
3896 u32 request_mask, unsigned int query_flags)
3897{
3898 struct inode *inode = d_inode(path->dentry);
3899 struct task_struct *p = get_proc_task(inode);
3900 generic_fillattr(&init_user_ns, inode, stat);
3901
3902 if (p) {
3903 stat->nlink += get_nr_threads(p);
3904 put_task_struct(p);
3905 }
3906
3907 return 0;
3908}
3909
3910static const struct inode_operations proc_task_inode_operations = {
3911 .lookup = proc_task_lookup,
3912 .getattr = proc_task_getattr,
3913 .setattr = proc_setattr,
3914 .permission = proc_pid_permission,
3915};
3916
3917static const struct file_operations proc_task_operations = {
3918 .read = generic_read_dir,
3919 .iterate_shared = proc_task_readdir,
3920 .llseek = generic_file_llseek,
3921};
3922
3923void __init set_proc_pid_nlink(void)
3924{
3925 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3926 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3927}
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 <trace/events/oom.h>
99#include "internal.h"
100#include "fd.h"
101
102#include "../../lib/kstrtox.h"
103
104/* NOTE:
105 * Implementing inode permission operations in /proc is almost
106 * certainly an error. Permission checks need to happen during
107 * each system call not at open time. The reason is that most of
108 * what we wish to check for permissions in /proc varies at runtime.
109 *
110 * The classic example of a problem is opening file descriptors
111 * in /proc for a task before it execs a suid executable.
112 */
113
114static u8 nlink_tid __ro_after_init;
115static u8 nlink_tgid __ro_after_init;
116
117struct pid_entry {
118 const char *name;
119 unsigned int len;
120 umode_t mode;
121 const struct inode_operations *iop;
122 const struct file_operations *fop;
123 union proc_op op;
124};
125
126#define NOD(NAME, MODE, IOP, FOP, OP) { \
127 .name = (NAME), \
128 .len = sizeof(NAME) - 1, \
129 .mode = MODE, \
130 .iop = IOP, \
131 .fop = FOP, \
132 .op = OP, \
133}
134
135#define DIR(NAME, MODE, iops, fops) \
136 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
137#define LNK(NAME, get_link) \
138 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
139 &proc_pid_link_inode_operations, NULL, \
140 { .proc_get_link = get_link } )
141#define REG(NAME, MODE, fops) \
142 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
143#define ONE(NAME, MODE, show) \
144 NOD(NAME, (S_IFREG|(MODE)), \
145 NULL, &proc_single_file_operations, \
146 { .proc_show = show } )
147#define ATTR(LSM, NAME, MODE) \
148 NOD(NAME, (S_IFREG|(MODE)), \
149 NULL, &proc_pid_attr_operations, \
150 { .lsm = LSM })
151
152/*
153 * Count the number of hardlinks for the pid_entry table, excluding the .
154 * and .. links.
155 */
156static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
157 unsigned int n)
158{
159 unsigned int i;
160 unsigned int count;
161
162 count = 2;
163 for (i = 0; i < n; ++i) {
164 if (S_ISDIR(entries[i].mode))
165 ++count;
166 }
167
168 return count;
169}
170
171static int get_task_root(struct task_struct *task, struct path *root)
172{
173 int result = -ENOENT;
174
175 task_lock(task);
176 if (task->fs) {
177 get_fs_root(task->fs, root);
178 result = 0;
179 }
180 task_unlock(task);
181 return result;
182}
183
184static int proc_cwd_link(struct dentry *dentry, struct path *path)
185{
186 struct task_struct *task = get_proc_task(d_inode(dentry));
187 int result = -ENOENT;
188
189 if (task) {
190 task_lock(task);
191 if (task->fs) {
192 get_fs_pwd(task->fs, path);
193 result = 0;
194 }
195 task_unlock(task);
196 put_task_struct(task);
197 }
198 return result;
199}
200
201static int proc_root_link(struct dentry *dentry, struct path *path)
202{
203 struct task_struct *task = get_proc_task(d_inode(dentry));
204 int result = -ENOENT;
205
206 if (task) {
207 result = get_task_root(task, path);
208 put_task_struct(task);
209 }
210 return result;
211}
212
213/*
214 * If the user used setproctitle(), we just get the string from
215 * user space at arg_start, and limit it to a maximum of one page.
216 */
217static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf,
218 size_t count, unsigned long pos,
219 unsigned long arg_start)
220{
221 char *page;
222 int ret, got;
223
224 if (pos >= PAGE_SIZE)
225 return 0;
226
227 page = (char *)__get_free_page(GFP_KERNEL);
228 if (!page)
229 return -ENOMEM;
230
231 ret = 0;
232 got = access_remote_vm(mm, arg_start, page, PAGE_SIZE, FOLL_ANON);
233 if (got > 0) {
234 int len = strnlen(page, got);
235
236 /* Include the NUL character if it was found */
237 if (len < got)
238 len++;
239
240 if (len > pos) {
241 len -= pos;
242 if (len > count)
243 len = count;
244 len -= copy_to_user(buf, page+pos, len);
245 if (!len)
246 len = -EFAULT;
247 ret = len;
248 }
249 }
250 free_page((unsigned long)page);
251 return ret;
252}
253
254static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
255 size_t count, loff_t *ppos)
256{
257 unsigned long arg_start, arg_end, env_start, env_end;
258 unsigned long pos, len;
259 char *page, c;
260
261 /* Check if process spawned far enough to have cmdline. */
262 if (!mm->env_end)
263 return 0;
264
265 spin_lock(&mm->arg_lock);
266 arg_start = mm->arg_start;
267 arg_end = mm->arg_end;
268 env_start = mm->env_start;
269 env_end = mm->env_end;
270 spin_unlock(&mm->arg_lock);
271
272 if (arg_start >= arg_end)
273 return 0;
274
275 /*
276 * We allow setproctitle() to overwrite the argument
277 * strings, and overflow past the original end. But
278 * only when it overflows into the environment area.
279 */
280 if (env_start != arg_end || env_end < env_start)
281 env_start = env_end = arg_end;
282 len = env_end - arg_start;
283
284 /* We're not going to care if "*ppos" has high bits set */
285 pos = *ppos;
286 if (pos >= len)
287 return 0;
288 if (count > len - pos)
289 count = len - pos;
290 if (!count)
291 return 0;
292
293 /*
294 * Magical special case: if the argv[] end byte is not
295 * zero, the user has overwritten it with setproctitle(3).
296 *
297 * Possible future enhancement: do this only once when
298 * pos is 0, and set a flag in the 'struct file'.
299 */
300 if (access_remote_vm(mm, arg_end-1, &c, 1, FOLL_ANON) == 1 && c)
301 return get_mm_proctitle(mm, buf, count, pos, arg_start);
302
303 /*
304 * For the non-setproctitle() case we limit things strictly
305 * to the [arg_start, arg_end[ range.
306 */
307 pos += arg_start;
308 if (pos < arg_start || pos >= arg_end)
309 return 0;
310 if (count > arg_end - pos)
311 count = arg_end - pos;
312
313 page = (char *)__get_free_page(GFP_KERNEL);
314 if (!page)
315 return -ENOMEM;
316
317 len = 0;
318 while (count) {
319 int got;
320 size_t size = min_t(size_t, PAGE_SIZE, count);
321
322 got = access_remote_vm(mm, pos, page, size, FOLL_ANON);
323 if (got <= 0)
324 break;
325 got -= copy_to_user(buf, page, got);
326 if (unlikely(!got)) {
327 if (!len)
328 len = -EFAULT;
329 break;
330 }
331 pos += got;
332 buf += got;
333 len += got;
334 count -= got;
335 }
336
337 free_page((unsigned long)page);
338 return len;
339}
340
341static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf,
342 size_t count, loff_t *pos)
343{
344 struct mm_struct *mm;
345 ssize_t ret;
346
347 mm = get_task_mm(tsk);
348 if (!mm)
349 return 0;
350
351 ret = get_mm_cmdline(mm, buf, count, pos);
352 mmput(mm);
353 return ret;
354}
355
356static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
357 size_t count, loff_t *pos)
358{
359 struct task_struct *tsk;
360 ssize_t ret;
361
362 BUG_ON(*pos < 0);
363
364 tsk = get_proc_task(file_inode(file));
365 if (!tsk)
366 return -ESRCH;
367 ret = get_task_cmdline(tsk, buf, count, pos);
368 put_task_struct(tsk);
369 if (ret > 0)
370 *pos += ret;
371 return ret;
372}
373
374static const struct file_operations proc_pid_cmdline_ops = {
375 .read = proc_pid_cmdline_read,
376 .llseek = generic_file_llseek,
377};
378
379#ifdef CONFIG_KALLSYMS
380/*
381 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
382 * Returns the resolved symbol. If that fails, simply return the address.
383 */
384static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
385 struct pid *pid, struct task_struct *task)
386{
387 unsigned long wchan;
388
389 if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
390 wchan = get_wchan(task);
391 else
392 wchan = 0;
393
394 if (wchan)
395 seq_printf(m, "%ps", (void *) wchan);
396 else
397 seq_putc(m, '0');
398
399 return 0;
400}
401#endif /* CONFIG_KALLSYMS */
402
403static int lock_trace(struct task_struct *task)
404{
405 int err = down_read_killable(&task->signal->exec_update_lock);
406 if (err)
407 return err;
408 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
409 up_read(&task->signal->exec_update_lock);
410 return -EPERM;
411 }
412 return 0;
413}
414
415static void unlock_trace(struct task_struct *task)
416{
417 up_read(&task->signal->exec_update_lock);
418}
419
420#ifdef CONFIG_STACKTRACE
421
422#define MAX_STACK_TRACE_DEPTH 64
423
424static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
425 struct pid *pid, struct task_struct *task)
426{
427 unsigned long *entries;
428 int err;
429
430 /*
431 * The ability to racily run the kernel stack unwinder on a running task
432 * and then observe the unwinder output is scary; while it is useful for
433 * debugging kernel issues, it can also allow an attacker to leak kernel
434 * stack contents.
435 * Doing this in a manner that is at least safe from races would require
436 * some work to ensure that the remote task can not be scheduled; and
437 * even then, this would still expose the unwinder as local attack
438 * surface.
439 * Therefore, this interface is restricted to root.
440 */
441 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
442 return -EACCES;
443
444 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
445 GFP_KERNEL);
446 if (!entries)
447 return -ENOMEM;
448
449 err = lock_trace(task);
450 if (!err) {
451 unsigned int i, nr_entries;
452
453 nr_entries = stack_trace_save_tsk(task, entries,
454 MAX_STACK_TRACE_DEPTH, 0);
455
456 for (i = 0; i < nr_entries; i++) {
457 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
458 }
459
460 unlock_trace(task);
461 }
462 kfree(entries);
463
464 return err;
465}
466#endif
467
468#ifdef CONFIG_SCHED_INFO
469/*
470 * Provides /proc/PID/schedstat
471 */
472static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
473 struct pid *pid, struct task_struct *task)
474{
475 if (unlikely(!sched_info_on()))
476 seq_puts(m, "0 0 0\n");
477 else
478 seq_printf(m, "%llu %llu %lu\n",
479 (unsigned long long)task->se.sum_exec_runtime,
480 (unsigned long long)task->sched_info.run_delay,
481 task->sched_info.pcount);
482
483 return 0;
484}
485#endif
486
487#ifdef CONFIG_LATENCYTOP
488static int lstats_show_proc(struct seq_file *m, void *v)
489{
490 int i;
491 struct inode *inode = m->private;
492 struct task_struct *task = get_proc_task(inode);
493
494 if (!task)
495 return -ESRCH;
496 seq_puts(m, "Latency Top version : v0.1\n");
497 for (i = 0; i < LT_SAVECOUNT; i++) {
498 struct latency_record *lr = &task->latency_record[i];
499 if (lr->backtrace[0]) {
500 int q;
501 seq_printf(m, "%i %li %li",
502 lr->count, lr->time, lr->max);
503 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
504 unsigned long bt = lr->backtrace[q];
505
506 if (!bt)
507 break;
508 seq_printf(m, " %ps", (void *)bt);
509 }
510 seq_putc(m, '\n');
511 }
512
513 }
514 put_task_struct(task);
515 return 0;
516}
517
518static int lstats_open(struct inode *inode, struct file *file)
519{
520 return single_open(file, lstats_show_proc, inode);
521}
522
523static ssize_t lstats_write(struct file *file, const char __user *buf,
524 size_t count, loff_t *offs)
525{
526 struct task_struct *task = get_proc_task(file_inode(file));
527
528 if (!task)
529 return -ESRCH;
530 clear_tsk_latency_tracing(task);
531 put_task_struct(task);
532
533 return count;
534}
535
536static const struct file_operations proc_lstats_operations = {
537 .open = lstats_open,
538 .read = seq_read,
539 .write = lstats_write,
540 .llseek = seq_lseek,
541 .release = single_release,
542};
543
544#endif
545
546static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
547 struct pid *pid, struct task_struct *task)
548{
549 unsigned long totalpages = totalram_pages() + total_swap_pages;
550 unsigned long points = 0;
551 long badness;
552
553 badness = oom_badness(task, totalpages);
554 /*
555 * Special case OOM_SCORE_ADJ_MIN for all others scale the
556 * badness value into [0, 2000] range which we have been
557 * exporting for a long time so userspace might depend on it.
558 */
559 if (badness != LONG_MIN)
560 points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3;
561
562 seq_printf(m, "%lu\n", points);
563
564 return 0;
565}
566
567struct limit_names {
568 const char *name;
569 const char *unit;
570};
571
572static const struct limit_names lnames[RLIM_NLIMITS] = {
573 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
574 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
575 [RLIMIT_DATA] = {"Max data size", "bytes"},
576 [RLIMIT_STACK] = {"Max stack size", "bytes"},
577 [RLIMIT_CORE] = {"Max core file size", "bytes"},
578 [RLIMIT_RSS] = {"Max resident set", "bytes"},
579 [RLIMIT_NPROC] = {"Max processes", "processes"},
580 [RLIMIT_NOFILE] = {"Max open files", "files"},
581 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
582 [RLIMIT_AS] = {"Max address space", "bytes"},
583 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
584 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
585 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
586 [RLIMIT_NICE] = {"Max nice priority", NULL},
587 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
588 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
589};
590
591/* Display limits for a process */
592static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
593 struct pid *pid, struct task_struct *task)
594{
595 unsigned int i;
596 unsigned long flags;
597
598 struct rlimit rlim[RLIM_NLIMITS];
599
600 if (!lock_task_sighand(task, &flags))
601 return 0;
602 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
603 unlock_task_sighand(task, &flags);
604
605 /*
606 * print the file header
607 */
608 seq_puts(m, "Limit "
609 "Soft Limit "
610 "Hard Limit "
611 "Units \n");
612
613 for (i = 0; i < RLIM_NLIMITS; i++) {
614 if (rlim[i].rlim_cur == RLIM_INFINITY)
615 seq_printf(m, "%-25s %-20s ",
616 lnames[i].name, "unlimited");
617 else
618 seq_printf(m, "%-25s %-20lu ",
619 lnames[i].name, rlim[i].rlim_cur);
620
621 if (rlim[i].rlim_max == RLIM_INFINITY)
622 seq_printf(m, "%-20s ", "unlimited");
623 else
624 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
625
626 if (lnames[i].unit)
627 seq_printf(m, "%-10s\n", lnames[i].unit);
628 else
629 seq_putc(m, '\n');
630 }
631
632 return 0;
633}
634
635#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
636static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
637 struct pid *pid, struct task_struct *task)
638{
639 struct syscall_info info;
640 u64 *args = &info.data.args[0];
641 int res;
642
643 res = lock_trace(task);
644 if (res)
645 return res;
646
647 if (task_current_syscall(task, &info))
648 seq_puts(m, "running\n");
649 else if (info.data.nr < 0)
650 seq_printf(m, "%d 0x%llx 0x%llx\n",
651 info.data.nr, info.sp, info.data.instruction_pointer);
652 else
653 seq_printf(m,
654 "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
655 info.data.nr,
656 args[0], args[1], args[2], args[3], args[4], args[5],
657 info.sp, info.data.instruction_pointer);
658 unlock_trace(task);
659
660 return 0;
661}
662#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
663
664/************************************************************************/
665/* Here the fs part begins */
666/************************************************************************/
667
668/* permission checks */
669static int proc_fd_access_allowed(struct inode *inode)
670{
671 struct task_struct *task;
672 int allowed = 0;
673 /* Allow access to a task's file descriptors if it is us or we
674 * may use ptrace attach to the process and find out that
675 * information.
676 */
677 task = get_proc_task(inode);
678 if (task) {
679 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
680 put_task_struct(task);
681 }
682 return allowed;
683}
684
685int proc_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
686 struct iattr *attr)
687{
688 int error;
689 struct inode *inode = d_inode(dentry);
690
691 if (attr->ia_valid & ATTR_MODE)
692 return -EPERM;
693
694 error = setattr_prepare(&init_user_ns, dentry, attr);
695 if (error)
696 return error;
697
698 setattr_copy(&init_user_ns, inode, attr);
699 mark_inode_dirty(inode);
700 return 0;
701}
702
703/*
704 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
705 * or euid/egid (for hide_pid_min=2)?
706 */
707static bool has_pid_permissions(struct proc_fs_info *fs_info,
708 struct task_struct *task,
709 enum proc_hidepid hide_pid_min)
710{
711 /*
712 * If 'hidpid' mount option is set force a ptrace check,
713 * we indicate that we are using a filesystem syscall
714 * by passing PTRACE_MODE_READ_FSCREDS
715 */
716 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE)
717 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
718
719 if (fs_info->hide_pid < hide_pid_min)
720 return true;
721 if (in_group_p(fs_info->pid_gid))
722 return true;
723 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
724}
725
726
727static int proc_pid_permission(struct user_namespace *mnt_userns,
728 struct inode *inode, int mask)
729{
730 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
731 struct task_struct *task;
732 bool has_perms;
733
734 task = get_proc_task(inode);
735 if (!task)
736 return -ESRCH;
737 has_perms = has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS);
738 put_task_struct(task);
739
740 if (!has_perms) {
741 if (fs_info->hide_pid == HIDEPID_INVISIBLE) {
742 /*
743 * Let's make getdents(), stat(), and open()
744 * consistent with each other. If a process
745 * may not stat() a file, it shouldn't be seen
746 * in procfs at all.
747 */
748 return -ENOENT;
749 }
750
751 return -EPERM;
752 }
753 return generic_permission(&init_user_ns, inode, mask);
754}
755
756
757
758static const struct inode_operations proc_def_inode_operations = {
759 .setattr = proc_setattr,
760};
761
762static int proc_single_show(struct seq_file *m, void *v)
763{
764 struct inode *inode = m->private;
765 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
766 struct pid *pid = proc_pid(inode);
767 struct task_struct *task;
768 int ret;
769
770 task = get_pid_task(pid, PIDTYPE_PID);
771 if (!task)
772 return -ESRCH;
773
774 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
775
776 put_task_struct(task);
777 return ret;
778}
779
780static int proc_single_open(struct inode *inode, struct file *filp)
781{
782 return single_open(filp, proc_single_show, inode);
783}
784
785static const struct file_operations proc_single_file_operations = {
786 .open = proc_single_open,
787 .read = seq_read,
788 .llseek = seq_lseek,
789 .release = single_release,
790};
791
792
793struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
794{
795 struct task_struct *task = get_proc_task(inode);
796 struct mm_struct *mm = ERR_PTR(-ESRCH);
797
798 if (task) {
799 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
800 put_task_struct(task);
801
802 if (!IS_ERR_OR_NULL(mm)) {
803 /* ensure this mm_struct can't be freed */
804 mmgrab(mm);
805 /* but do not pin its memory */
806 mmput(mm);
807 }
808 }
809
810 return mm;
811}
812
813static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
814{
815 struct mm_struct *mm = proc_mem_open(inode, mode);
816
817 if (IS_ERR(mm))
818 return PTR_ERR(mm);
819
820 file->private_data = mm;
821 return 0;
822}
823
824static int mem_open(struct inode *inode, struct file *file)
825{
826 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
827
828 /* OK to pass negative loff_t, we can catch out-of-range */
829 file->f_mode |= FMODE_UNSIGNED_OFFSET;
830
831 return ret;
832}
833
834static ssize_t mem_rw(struct file *file, char __user *buf,
835 size_t count, loff_t *ppos, int write)
836{
837 struct mm_struct *mm = file->private_data;
838 unsigned long addr = *ppos;
839 ssize_t copied;
840 char *page;
841 unsigned int flags;
842
843 if (!mm)
844 return 0;
845
846 page = (char *)__get_free_page(GFP_KERNEL);
847 if (!page)
848 return -ENOMEM;
849
850 copied = 0;
851 if (!mmget_not_zero(mm))
852 goto free;
853
854 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
855
856 while (count > 0) {
857 size_t this_len = min_t(size_t, count, PAGE_SIZE);
858
859 if (write && copy_from_user(page, buf, this_len)) {
860 copied = -EFAULT;
861 break;
862 }
863
864 this_len = access_remote_vm(mm, addr, page, this_len, flags);
865 if (!this_len) {
866 if (!copied)
867 copied = -EIO;
868 break;
869 }
870
871 if (!write && copy_to_user(buf, page, this_len)) {
872 copied = -EFAULT;
873 break;
874 }
875
876 buf += this_len;
877 addr += this_len;
878 copied += this_len;
879 count -= this_len;
880 }
881 *ppos = addr;
882
883 mmput(mm);
884free:
885 free_page((unsigned long) page);
886 return copied;
887}
888
889static ssize_t mem_read(struct file *file, char __user *buf,
890 size_t count, loff_t *ppos)
891{
892 return mem_rw(file, buf, count, ppos, 0);
893}
894
895static ssize_t mem_write(struct file *file, const char __user *buf,
896 size_t count, loff_t *ppos)
897{
898 return mem_rw(file, (char __user*)buf, count, ppos, 1);
899}
900
901loff_t mem_lseek(struct file *file, loff_t offset, int orig)
902{
903 switch (orig) {
904 case 0:
905 file->f_pos = offset;
906 break;
907 case 1:
908 file->f_pos += offset;
909 break;
910 default:
911 return -EINVAL;
912 }
913 force_successful_syscall_return();
914 return file->f_pos;
915}
916
917static int mem_release(struct inode *inode, struct file *file)
918{
919 struct mm_struct *mm = file->private_data;
920 if (mm)
921 mmdrop(mm);
922 return 0;
923}
924
925static const struct file_operations proc_mem_operations = {
926 .llseek = mem_lseek,
927 .read = mem_read,
928 .write = mem_write,
929 .open = mem_open,
930 .release = mem_release,
931};
932
933static int environ_open(struct inode *inode, struct file *file)
934{
935 return __mem_open(inode, file, PTRACE_MODE_READ);
936}
937
938static ssize_t environ_read(struct file *file, char __user *buf,
939 size_t count, loff_t *ppos)
940{
941 char *page;
942 unsigned long src = *ppos;
943 int ret = 0;
944 struct mm_struct *mm = file->private_data;
945 unsigned long env_start, env_end;
946
947 /* Ensure the process spawned far enough to have an environment. */
948 if (!mm || !mm->env_end)
949 return 0;
950
951 page = (char *)__get_free_page(GFP_KERNEL);
952 if (!page)
953 return -ENOMEM;
954
955 ret = 0;
956 if (!mmget_not_zero(mm))
957 goto free;
958
959 spin_lock(&mm->arg_lock);
960 env_start = mm->env_start;
961 env_end = mm->env_end;
962 spin_unlock(&mm->arg_lock);
963
964 while (count > 0) {
965 size_t this_len, max_len;
966 int retval;
967
968 if (src >= (env_end - env_start))
969 break;
970
971 this_len = env_end - (env_start + src);
972
973 max_len = min_t(size_t, PAGE_SIZE, count);
974 this_len = min(max_len, this_len);
975
976 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
977
978 if (retval <= 0) {
979 ret = retval;
980 break;
981 }
982
983 if (copy_to_user(buf, page, retval)) {
984 ret = -EFAULT;
985 break;
986 }
987
988 ret += retval;
989 src += retval;
990 buf += retval;
991 count -= retval;
992 }
993 *ppos = src;
994 mmput(mm);
995
996free:
997 free_page((unsigned long) page);
998 return ret;
999}
1000
1001static const struct file_operations proc_environ_operations = {
1002 .open = environ_open,
1003 .read = environ_read,
1004 .llseek = generic_file_llseek,
1005 .release = mem_release,
1006};
1007
1008static int auxv_open(struct inode *inode, struct file *file)
1009{
1010 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1011}
1012
1013static ssize_t auxv_read(struct file *file, char __user *buf,
1014 size_t count, loff_t *ppos)
1015{
1016 struct mm_struct *mm = file->private_data;
1017 unsigned int nwords = 0;
1018
1019 if (!mm)
1020 return 0;
1021 do {
1022 nwords += 2;
1023 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1024 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1025 nwords * sizeof(mm->saved_auxv[0]));
1026}
1027
1028static const struct file_operations proc_auxv_operations = {
1029 .open = auxv_open,
1030 .read = auxv_read,
1031 .llseek = generic_file_llseek,
1032 .release = mem_release,
1033};
1034
1035static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1036 loff_t *ppos)
1037{
1038 struct task_struct *task = get_proc_task(file_inode(file));
1039 char buffer[PROC_NUMBUF];
1040 int oom_adj = OOM_ADJUST_MIN;
1041 size_t len;
1042
1043 if (!task)
1044 return -ESRCH;
1045 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1046 oom_adj = OOM_ADJUST_MAX;
1047 else
1048 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1049 OOM_SCORE_ADJ_MAX;
1050 put_task_struct(task);
1051 if (oom_adj > OOM_ADJUST_MAX)
1052 oom_adj = OOM_ADJUST_MAX;
1053 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1054 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1055}
1056
1057static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1058{
1059 struct mm_struct *mm = NULL;
1060 struct task_struct *task;
1061 int err = 0;
1062
1063 task = get_proc_task(file_inode(file));
1064 if (!task)
1065 return -ESRCH;
1066
1067 mutex_lock(&oom_adj_mutex);
1068 if (legacy) {
1069 if (oom_adj < task->signal->oom_score_adj &&
1070 !capable(CAP_SYS_RESOURCE)) {
1071 err = -EACCES;
1072 goto err_unlock;
1073 }
1074 /*
1075 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1076 * /proc/pid/oom_score_adj instead.
1077 */
1078 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1079 current->comm, task_pid_nr(current), task_pid_nr(task),
1080 task_pid_nr(task));
1081 } else {
1082 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1083 !capable(CAP_SYS_RESOURCE)) {
1084 err = -EACCES;
1085 goto err_unlock;
1086 }
1087 }
1088
1089 /*
1090 * Make sure we will check other processes sharing the mm if this is
1091 * not vfrok which wants its own oom_score_adj.
1092 * pin the mm so it doesn't go away and get reused after task_unlock
1093 */
1094 if (!task->vfork_done) {
1095 struct task_struct *p = find_lock_task_mm(task);
1096
1097 if (p) {
1098 if (test_bit(MMF_MULTIPROCESS, &p->mm->flags)) {
1099 mm = p->mm;
1100 mmgrab(mm);
1101 }
1102 task_unlock(p);
1103 }
1104 }
1105
1106 task->signal->oom_score_adj = oom_adj;
1107 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1108 task->signal->oom_score_adj_min = (short)oom_adj;
1109 trace_oom_score_adj_update(task);
1110
1111 if (mm) {
1112 struct task_struct *p;
1113
1114 rcu_read_lock();
1115 for_each_process(p) {
1116 if (same_thread_group(task, p))
1117 continue;
1118
1119 /* do not touch kernel threads or the global init */
1120 if (p->flags & PF_KTHREAD || is_global_init(p))
1121 continue;
1122
1123 task_lock(p);
1124 if (!p->vfork_done && process_shares_mm(p, mm)) {
1125 p->signal->oom_score_adj = oom_adj;
1126 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1127 p->signal->oom_score_adj_min = (short)oom_adj;
1128 }
1129 task_unlock(p);
1130 }
1131 rcu_read_unlock();
1132 mmdrop(mm);
1133 }
1134err_unlock:
1135 mutex_unlock(&oom_adj_mutex);
1136 put_task_struct(task);
1137 return err;
1138}
1139
1140/*
1141 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1142 * kernels. The effective policy is defined by oom_score_adj, which has a
1143 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1144 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1145 * Processes that become oom disabled via oom_adj will still be oom disabled
1146 * with this implementation.
1147 *
1148 * oom_adj cannot be removed since existing userspace binaries use it.
1149 */
1150static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1151 size_t count, loff_t *ppos)
1152{
1153 char buffer[PROC_NUMBUF];
1154 int oom_adj;
1155 int err;
1156
1157 memset(buffer, 0, sizeof(buffer));
1158 if (count > sizeof(buffer) - 1)
1159 count = sizeof(buffer) - 1;
1160 if (copy_from_user(buffer, buf, count)) {
1161 err = -EFAULT;
1162 goto out;
1163 }
1164
1165 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1166 if (err)
1167 goto out;
1168 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1169 oom_adj != OOM_DISABLE) {
1170 err = -EINVAL;
1171 goto out;
1172 }
1173
1174 /*
1175 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1176 * value is always attainable.
1177 */
1178 if (oom_adj == OOM_ADJUST_MAX)
1179 oom_adj = OOM_SCORE_ADJ_MAX;
1180 else
1181 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1182
1183 err = __set_oom_adj(file, oom_adj, true);
1184out:
1185 return err < 0 ? err : count;
1186}
1187
1188static const struct file_operations proc_oom_adj_operations = {
1189 .read = oom_adj_read,
1190 .write = oom_adj_write,
1191 .llseek = generic_file_llseek,
1192};
1193
1194static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1195 size_t count, loff_t *ppos)
1196{
1197 struct task_struct *task = get_proc_task(file_inode(file));
1198 char buffer[PROC_NUMBUF];
1199 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1200 size_t len;
1201
1202 if (!task)
1203 return -ESRCH;
1204 oom_score_adj = task->signal->oom_score_adj;
1205 put_task_struct(task);
1206 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1207 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1208}
1209
1210static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1211 size_t count, loff_t *ppos)
1212{
1213 char buffer[PROC_NUMBUF];
1214 int oom_score_adj;
1215 int err;
1216
1217 memset(buffer, 0, sizeof(buffer));
1218 if (count > sizeof(buffer) - 1)
1219 count = sizeof(buffer) - 1;
1220 if (copy_from_user(buffer, buf, count)) {
1221 err = -EFAULT;
1222 goto out;
1223 }
1224
1225 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1226 if (err)
1227 goto out;
1228 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1229 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1230 err = -EINVAL;
1231 goto out;
1232 }
1233
1234 err = __set_oom_adj(file, oom_score_adj, false);
1235out:
1236 return err < 0 ? err : count;
1237}
1238
1239static const struct file_operations proc_oom_score_adj_operations = {
1240 .read = oom_score_adj_read,
1241 .write = oom_score_adj_write,
1242 .llseek = default_llseek,
1243};
1244
1245#ifdef CONFIG_AUDIT
1246#define TMPBUFLEN 11
1247static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1248 size_t count, loff_t *ppos)
1249{
1250 struct inode * inode = file_inode(file);
1251 struct task_struct *task = get_proc_task(inode);
1252 ssize_t length;
1253 char tmpbuf[TMPBUFLEN];
1254
1255 if (!task)
1256 return -ESRCH;
1257 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1258 from_kuid(file->f_cred->user_ns,
1259 audit_get_loginuid(task)));
1260 put_task_struct(task);
1261 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1262}
1263
1264static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1265 size_t count, loff_t *ppos)
1266{
1267 struct inode * inode = file_inode(file);
1268 uid_t loginuid;
1269 kuid_t kloginuid;
1270 int rv;
1271
1272 /* Don't let kthreads write their own loginuid */
1273 if (current->flags & PF_KTHREAD)
1274 return -EPERM;
1275
1276 rcu_read_lock();
1277 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1278 rcu_read_unlock();
1279 return -EPERM;
1280 }
1281 rcu_read_unlock();
1282
1283 if (*ppos != 0) {
1284 /* No partial writes. */
1285 return -EINVAL;
1286 }
1287
1288 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1289 if (rv < 0)
1290 return rv;
1291
1292 /* is userspace tring to explicitly UNSET the loginuid? */
1293 if (loginuid == AUDIT_UID_UNSET) {
1294 kloginuid = INVALID_UID;
1295 } else {
1296 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1297 if (!uid_valid(kloginuid))
1298 return -EINVAL;
1299 }
1300
1301 rv = audit_set_loginuid(kloginuid);
1302 if (rv < 0)
1303 return rv;
1304 return count;
1305}
1306
1307static const struct file_operations proc_loginuid_operations = {
1308 .read = proc_loginuid_read,
1309 .write = proc_loginuid_write,
1310 .llseek = generic_file_llseek,
1311};
1312
1313static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1314 size_t count, loff_t *ppos)
1315{
1316 struct inode * inode = file_inode(file);
1317 struct task_struct *task = get_proc_task(inode);
1318 ssize_t length;
1319 char tmpbuf[TMPBUFLEN];
1320
1321 if (!task)
1322 return -ESRCH;
1323 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1324 audit_get_sessionid(task));
1325 put_task_struct(task);
1326 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1327}
1328
1329static const struct file_operations proc_sessionid_operations = {
1330 .read = proc_sessionid_read,
1331 .llseek = generic_file_llseek,
1332};
1333#endif
1334
1335#ifdef CONFIG_FAULT_INJECTION
1336static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1337 size_t count, loff_t *ppos)
1338{
1339 struct task_struct *task = get_proc_task(file_inode(file));
1340 char buffer[PROC_NUMBUF];
1341 size_t len;
1342 int make_it_fail;
1343
1344 if (!task)
1345 return -ESRCH;
1346 make_it_fail = task->make_it_fail;
1347 put_task_struct(task);
1348
1349 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1350
1351 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1352}
1353
1354static ssize_t proc_fault_inject_write(struct file * file,
1355 const char __user * buf, size_t count, loff_t *ppos)
1356{
1357 struct task_struct *task;
1358 char buffer[PROC_NUMBUF];
1359 int make_it_fail;
1360 int rv;
1361
1362 if (!capable(CAP_SYS_RESOURCE))
1363 return -EPERM;
1364 memset(buffer, 0, sizeof(buffer));
1365 if (count > sizeof(buffer) - 1)
1366 count = sizeof(buffer) - 1;
1367 if (copy_from_user(buffer, buf, count))
1368 return -EFAULT;
1369 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1370 if (rv < 0)
1371 return rv;
1372 if (make_it_fail < 0 || make_it_fail > 1)
1373 return -EINVAL;
1374
1375 task = get_proc_task(file_inode(file));
1376 if (!task)
1377 return -ESRCH;
1378 task->make_it_fail = make_it_fail;
1379 put_task_struct(task);
1380
1381 return count;
1382}
1383
1384static const struct file_operations proc_fault_inject_operations = {
1385 .read = proc_fault_inject_read,
1386 .write = proc_fault_inject_write,
1387 .llseek = generic_file_llseek,
1388};
1389
1390static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1391 size_t count, loff_t *ppos)
1392{
1393 struct task_struct *task;
1394 int err;
1395 unsigned int n;
1396
1397 err = kstrtouint_from_user(buf, count, 0, &n);
1398 if (err)
1399 return err;
1400
1401 task = get_proc_task(file_inode(file));
1402 if (!task)
1403 return -ESRCH;
1404 task->fail_nth = n;
1405 put_task_struct(task);
1406
1407 return count;
1408}
1409
1410static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1411 size_t count, loff_t *ppos)
1412{
1413 struct task_struct *task;
1414 char numbuf[PROC_NUMBUF];
1415 ssize_t len;
1416
1417 task = get_proc_task(file_inode(file));
1418 if (!task)
1419 return -ESRCH;
1420 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1421 put_task_struct(task);
1422 return simple_read_from_buffer(buf, count, ppos, numbuf, len);
1423}
1424
1425static const struct file_operations proc_fail_nth_operations = {
1426 .read = proc_fail_nth_read,
1427 .write = proc_fail_nth_write,
1428};
1429#endif
1430
1431
1432#ifdef CONFIG_SCHED_DEBUG
1433/*
1434 * Print out various scheduling related per-task fields:
1435 */
1436static int sched_show(struct seq_file *m, void *v)
1437{
1438 struct inode *inode = m->private;
1439 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
1440 struct task_struct *p;
1441
1442 p = get_proc_task(inode);
1443 if (!p)
1444 return -ESRCH;
1445 proc_sched_show_task(p, ns, m);
1446
1447 put_task_struct(p);
1448
1449 return 0;
1450}
1451
1452static ssize_t
1453sched_write(struct file *file, const char __user *buf,
1454 size_t count, loff_t *offset)
1455{
1456 struct inode *inode = file_inode(file);
1457 struct task_struct *p;
1458
1459 p = get_proc_task(inode);
1460 if (!p)
1461 return -ESRCH;
1462 proc_sched_set_task(p);
1463
1464 put_task_struct(p);
1465
1466 return count;
1467}
1468
1469static int sched_open(struct inode *inode, struct file *filp)
1470{
1471 return single_open(filp, sched_show, inode);
1472}
1473
1474static const struct file_operations proc_pid_sched_operations = {
1475 .open = sched_open,
1476 .read = seq_read,
1477 .write = sched_write,
1478 .llseek = seq_lseek,
1479 .release = single_release,
1480};
1481
1482#endif
1483
1484#ifdef CONFIG_SCHED_AUTOGROUP
1485/*
1486 * Print out autogroup related information:
1487 */
1488static int sched_autogroup_show(struct seq_file *m, void *v)
1489{
1490 struct inode *inode = m->private;
1491 struct task_struct *p;
1492
1493 p = get_proc_task(inode);
1494 if (!p)
1495 return -ESRCH;
1496 proc_sched_autogroup_show_task(p, m);
1497
1498 put_task_struct(p);
1499
1500 return 0;
1501}
1502
1503static ssize_t
1504sched_autogroup_write(struct file *file, const char __user *buf,
1505 size_t count, loff_t *offset)
1506{
1507 struct inode *inode = file_inode(file);
1508 struct task_struct *p;
1509 char buffer[PROC_NUMBUF];
1510 int nice;
1511 int err;
1512
1513 memset(buffer, 0, sizeof(buffer));
1514 if (count > sizeof(buffer) - 1)
1515 count = sizeof(buffer) - 1;
1516 if (copy_from_user(buffer, buf, count))
1517 return -EFAULT;
1518
1519 err = kstrtoint(strstrip(buffer), 0, &nice);
1520 if (err < 0)
1521 return err;
1522
1523 p = get_proc_task(inode);
1524 if (!p)
1525 return -ESRCH;
1526
1527 err = proc_sched_autogroup_set_nice(p, nice);
1528 if (err)
1529 count = err;
1530
1531 put_task_struct(p);
1532
1533 return count;
1534}
1535
1536static int sched_autogroup_open(struct inode *inode, struct file *filp)
1537{
1538 int ret;
1539
1540 ret = single_open(filp, sched_autogroup_show, NULL);
1541 if (!ret) {
1542 struct seq_file *m = filp->private_data;
1543
1544 m->private = inode;
1545 }
1546 return ret;
1547}
1548
1549static const struct file_operations proc_pid_sched_autogroup_operations = {
1550 .open = sched_autogroup_open,
1551 .read = seq_read,
1552 .write = sched_autogroup_write,
1553 .llseek = seq_lseek,
1554 .release = single_release,
1555};
1556
1557#endif /* CONFIG_SCHED_AUTOGROUP */
1558
1559#ifdef CONFIG_TIME_NS
1560static int timens_offsets_show(struct seq_file *m, void *v)
1561{
1562 struct task_struct *p;
1563
1564 p = get_proc_task(file_inode(m->file));
1565 if (!p)
1566 return -ESRCH;
1567 proc_timens_show_offsets(p, m);
1568
1569 put_task_struct(p);
1570
1571 return 0;
1572}
1573
1574static ssize_t timens_offsets_write(struct file *file, const char __user *buf,
1575 size_t count, loff_t *ppos)
1576{
1577 struct inode *inode = file_inode(file);
1578 struct proc_timens_offset offsets[2];
1579 char *kbuf = NULL, *pos, *next_line;
1580 struct task_struct *p;
1581 int ret, noffsets;
1582
1583 /* Only allow < page size writes at the beginning of the file */
1584 if ((*ppos != 0) || (count >= PAGE_SIZE))
1585 return -EINVAL;
1586
1587 /* Slurp in the user data */
1588 kbuf = memdup_user_nul(buf, count);
1589 if (IS_ERR(kbuf))
1590 return PTR_ERR(kbuf);
1591
1592 /* Parse the user data */
1593 ret = -EINVAL;
1594 noffsets = 0;
1595 for (pos = kbuf; pos; pos = next_line) {
1596 struct proc_timens_offset *off = &offsets[noffsets];
1597 char clock[10];
1598 int err;
1599
1600 /* Find the end of line and ensure we don't look past it */
1601 next_line = strchr(pos, '\n');
1602 if (next_line) {
1603 *next_line = '\0';
1604 next_line++;
1605 if (*next_line == '\0')
1606 next_line = NULL;
1607 }
1608
1609 err = sscanf(pos, "%9s %lld %lu", clock,
1610 &off->val.tv_sec, &off->val.tv_nsec);
1611 if (err != 3 || off->val.tv_nsec >= NSEC_PER_SEC)
1612 goto out;
1613
1614 clock[sizeof(clock) - 1] = 0;
1615 if (strcmp(clock, "monotonic") == 0 ||
1616 strcmp(clock, __stringify(CLOCK_MONOTONIC)) == 0)
1617 off->clockid = CLOCK_MONOTONIC;
1618 else if (strcmp(clock, "boottime") == 0 ||
1619 strcmp(clock, __stringify(CLOCK_BOOTTIME)) == 0)
1620 off->clockid = CLOCK_BOOTTIME;
1621 else
1622 goto out;
1623
1624 noffsets++;
1625 if (noffsets == ARRAY_SIZE(offsets)) {
1626 if (next_line)
1627 count = next_line - kbuf;
1628 break;
1629 }
1630 }
1631
1632 ret = -ESRCH;
1633 p = get_proc_task(inode);
1634 if (!p)
1635 goto out;
1636 ret = proc_timens_set_offset(file, p, offsets, noffsets);
1637 put_task_struct(p);
1638 if (ret)
1639 goto out;
1640
1641 ret = count;
1642out:
1643 kfree(kbuf);
1644 return ret;
1645}
1646
1647static int timens_offsets_open(struct inode *inode, struct file *filp)
1648{
1649 return single_open(filp, timens_offsets_show, inode);
1650}
1651
1652static const struct file_operations proc_timens_offsets_operations = {
1653 .open = timens_offsets_open,
1654 .read = seq_read,
1655 .write = timens_offsets_write,
1656 .llseek = seq_lseek,
1657 .release = single_release,
1658};
1659#endif /* CONFIG_TIME_NS */
1660
1661static ssize_t comm_write(struct file *file, const char __user *buf,
1662 size_t count, loff_t *offset)
1663{
1664 struct inode *inode = file_inode(file);
1665 struct task_struct *p;
1666 char buffer[TASK_COMM_LEN];
1667 const size_t maxlen = sizeof(buffer) - 1;
1668
1669 memset(buffer, 0, sizeof(buffer));
1670 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1671 return -EFAULT;
1672
1673 p = get_proc_task(inode);
1674 if (!p)
1675 return -ESRCH;
1676
1677 if (same_thread_group(current, p))
1678 set_task_comm(p, buffer);
1679 else
1680 count = -EINVAL;
1681
1682 put_task_struct(p);
1683
1684 return count;
1685}
1686
1687static int comm_show(struct seq_file *m, void *v)
1688{
1689 struct inode *inode = m->private;
1690 struct task_struct *p;
1691
1692 p = get_proc_task(inode);
1693 if (!p)
1694 return -ESRCH;
1695
1696 proc_task_name(m, p, false);
1697 seq_putc(m, '\n');
1698
1699 put_task_struct(p);
1700
1701 return 0;
1702}
1703
1704static int comm_open(struct inode *inode, struct file *filp)
1705{
1706 return single_open(filp, comm_show, inode);
1707}
1708
1709static const struct file_operations proc_pid_set_comm_operations = {
1710 .open = comm_open,
1711 .read = seq_read,
1712 .write = comm_write,
1713 .llseek = seq_lseek,
1714 .release = single_release,
1715};
1716
1717static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1718{
1719 struct task_struct *task;
1720 struct file *exe_file;
1721
1722 task = get_proc_task(d_inode(dentry));
1723 if (!task)
1724 return -ENOENT;
1725 exe_file = get_task_exe_file(task);
1726 put_task_struct(task);
1727 if (exe_file) {
1728 *exe_path = exe_file->f_path;
1729 path_get(&exe_file->f_path);
1730 fput(exe_file);
1731 return 0;
1732 } else
1733 return -ENOENT;
1734}
1735
1736static const char *proc_pid_get_link(struct dentry *dentry,
1737 struct inode *inode,
1738 struct delayed_call *done)
1739{
1740 struct path path;
1741 int error = -EACCES;
1742
1743 if (!dentry)
1744 return ERR_PTR(-ECHILD);
1745
1746 /* Are we allowed to snoop on the tasks file descriptors? */
1747 if (!proc_fd_access_allowed(inode))
1748 goto out;
1749
1750 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1751 if (error)
1752 goto out;
1753
1754 error = nd_jump_link(&path);
1755out:
1756 return ERR_PTR(error);
1757}
1758
1759static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1760{
1761 char *tmp = (char *)__get_free_page(GFP_KERNEL);
1762 char *pathname;
1763 int len;
1764
1765 if (!tmp)
1766 return -ENOMEM;
1767
1768 pathname = d_path(path, tmp, PAGE_SIZE);
1769 len = PTR_ERR(pathname);
1770 if (IS_ERR(pathname))
1771 goto out;
1772 len = tmp + PAGE_SIZE - 1 - pathname;
1773
1774 if (len > buflen)
1775 len = buflen;
1776 if (copy_to_user(buffer, pathname, len))
1777 len = -EFAULT;
1778 out:
1779 free_page((unsigned long)tmp);
1780 return len;
1781}
1782
1783static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1784{
1785 int error = -EACCES;
1786 struct inode *inode = d_inode(dentry);
1787 struct path path;
1788
1789 /* Are we allowed to snoop on the tasks file descriptors? */
1790 if (!proc_fd_access_allowed(inode))
1791 goto out;
1792
1793 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1794 if (error)
1795 goto out;
1796
1797 error = do_proc_readlink(&path, buffer, buflen);
1798 path_put(&path);
1799out:
1800 return error;
1801}
1802
1803const struct inode_operations proc_pid_link_inode_operations = {
1804 .readlink = proc_pid_readlink,
1805 .get_link = proc_pid_get_link,
1806 .setattr = proc_setattr,
1807};
1808
1809
1810/* building an inode */
1811
1812void task_dump_owner(struct task_struct *task, umode_t mode,
1813 kuid_t *ruid, kgid_t *rgid)
1814{
1815 /* Depending on the state of dumpable compute who should own a
1816 * proc file for a task.
1817 */
1818 const struct cred *cred;
1819 kuid_t uid;
1820 kgid_t gid;
1821
1822 if (unlikely(task->flags & PF_KTHREAD)) {
1823 *ruid = GLOBAL_ROOT_UID;
1824 *rgid = GLOBAL_ROOT_GID;
1825 return;
1826 }
1827
1828 /* Default to the tasks effective ownership */
1829 rcu_read_lock();
1830 cred = __task_cred(task);
1831 uid = cred->euid;
1832 gid = cred->egid;
1833 rcu_read_unlock();
1834
1835 /*
1836 * Before the /proc/pid/status file was created the only way to read
1837 * the effective uid of a /process was to stat /proc/pid. Reading
1838 * /proc/pid/status is slow enough that procps and other packages
1839 * kept stating /proc/pid. To keep the rules in /proc simple I have
1840 * made this apply to all per process world readable and executable
1841 * directories.
1842 */
1843 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1844 struct mm_struct *mm;
1845 task_lock(task);
1846 mm = task->mm;
1847 /* Make non-dumpable tasks owned by some root */
1848 if (mm) {
1849 if (get_dumpable(mm) != SUID_DUMP_USER) {
1850 struct user_namespace *user_ns = mm->user_ns;
1851
1852 uid = make_kuid(user_ns, 0);
1853 if (!uid_valid(uid))
1854 uid = GLOBAL_ROOT_UID;
1855
1856 gid = make_kgid(user_ns, 0);
1857 if (!gid_valid(gid))
1858 gid = GLOBAL_ROOT_GID;
1859 }
1860 } else {
1861 uid = GLOBAL_ROOT_UID;
1862 gid = GLOBAL_ROOT_GID;
1863 }
1864 task_unlock(task);
1865 }
1866 *ruid = uid;
1867 *rgid = gid;
1868}
1869
1870void proc_pid_evict_inode(struct proc_inode *ei)
1871{
1872 struct pid *pid = ei->pid;
1873
1874 if (S_ISDIR(ei->vfs_inode.i_mode)) {
1875 spin_lock(&pid->lock);
1876 hlist_del_init_rcu(&ei->sibling_inodes);
1877 spin_unlock(&pid->lock);
1878 }
1879
1880 put_pid(pid);
1881}
1882
1883struct inode *proc_pid_make_inode(struct super_block * sb,
1884 struct task_struct *task, umode_t mode)
1885{
1886 struct inode * inode;
1887 struct proc_inode *ei;
1888 struct pid *pid;
1889
1890 /* We need a new inode */
1891
1892 inode = new_inode(sb);
1893 if (!inode)
1894 goto out;
1895
1896 /* Common stuff */
1897 ei = PROC_I(inode);
1898 inode->i_mode = mode;
1899 inode->i_ino = get_next_ino();
1900 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1901 inode->i_op = &proc_def_inode_operations;
1902
1903 /*
1904 * grab the reference to task.
1905 */
1906 pid = get_task_pid(task, PIDTYPE_PID);
1907 if (!pid)
1908 goto out_unlock;
1909
1910 /* Let the pid remember us for quick removal */
1911 ei->pid = pid;
1912 if (S_ISDIR(mode)) {
1913 spin_lock(&pid->lock);
1914 hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes);
1915 spin_unlock(&pid->lock);
1916 }
1917
1918 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1919 security_task_to_inode(task, inode);
1920
1921out:
1922 return inode;
1923
1924out_unlock:
1925 iput(inode);
1926 return NULL;
1927}
1928
1929int pid_getattr(struct user_namespace *mnt_userns, const struct path *path,
1930 struct kstat *stat, u32 request_mask, unsigned int query_flags)
1931{
1932 struct inode *inode = d_inode(path->dentry);
1933 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
1934 struct task_struct *task;
1935
1936 generic_fillattr(&init_user_ns, inode, stat);
1937
1938 stat->uid = GLOBAL_ROOT_UID;
1939 stat->gid = GLOBAL_ROOT_GID;
1940 rcu_read_lock();
1941 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1942 if (task) {
1943 if (!has_pid_permissions(fs_info, task, HIDEPID_INVISIBLE)) {
1944 rcu_read_unlock();
1945 /*
1946 * This doesn't prevent learning whether PID exists,
1947 * it only makes getattr() consistent with readdir().
1948 */
1949 return -ENOENT;
1950 }
1951 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1952 }
1953 rcu_read_unlock();
1954 return 0;
1955}
1956
1957/* dentry stuff */
1958
1959/*
1960 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
1961 */
1962void pid_update_inode(struct task_struct *task, struct inode *inode)
1963{
1964 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1965
1966 inode->i_mode &= ~(S_ISUID | S_ISGID);
1967 security_task_to_inode(task, inode);
1968}
1969
1970/*
1971 * Rewrite the inode's ownerships here because the owning task may have
1972 * performed a setuid(), etc.
1973 *
1974 */
1975static int pid_revalidate(struct dentry *dentry, unsigned int flags)
1976{
1977 struct inode *inode;
1978 struct task_struct *task;
1979
1980 if (flags & LOOKUP_RCU)
1981 return -ECHILD;
1982
1983 inode = d_inode(dentry);
1984 task = get_proc_task(inode);
1985
1986 if (task) {
1987 pid_update_inode(task, inode);
1988 put_task_struct(task);
1989 return 1;
1990 }
1991 return 0;
1992}
1993
1994static inline bool proc_inode_is_dead(struct inode *inode)
1995{
1996 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1997}
1998
1999int pid_delete_dentry(const struct dentry *dentry)
2000{
2001 /* Is the task we represent dead?
2002 * If so, then don't put the dentry on the lru list,
2003 * kill it immediately.
2004 */
2005 return proc_inode_is_dead(d_inode(dentry));
2006}
2007
2008const struct dentry_operations pid_dentry_operations =
2009{
2010 .d_revalidate = pid_revalidate,
2011 .d_delete = pid_delete_dentry,
2012};
2013
2014/* Lookups */
2015
2016/*
2017 * Fill a directory entry.
2018 *
2019 * If possible create the dcache entry and derive our inode number and
2020 * file type from dcache entry.
2021 *
2022 * Since all of the proc inode numbers are dynamically generated, the inode
2023 * numbers do not exist until the inode is cache. This means creating
2024 * the dcache entry in readdir is necessary to keep the inode numbers
2025 * reported by readdir in sync with the inode numbers reported
2026 * by stat.
2027 */
2028bool proc_fill_cache(struct file *file, struct dir_context *ctx,
2029 const char *name, unsigned int len,
2030 instantiate_t instantiate, struct task_struct *task, const void *ptr)
2031{
2032 struct dentry *child, *dir = file->f_path.dentry;
2033 struct qstr qname = QSTR_INIT(name, len);
2034 struct inode *inode;
2035 unsigned type = DT_UNKNOWN;
2036 ino_t ino = 1;
2037
2038 child = d_hash_and_lookup(dir, &qname);
2039 if (!child) {
2040 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
2041 child = d_alloc_parallel(dir, &qname, &wq);
2042 if (IS_ERR(child))
2043 goto end_instantiate;
2044 if (d_in_lookup(child)) {
2045 struct dentry *res;
2046 res = instantiate(child, task, ptr);
2047 d_lookup_done(child);
2048 if (unlikely(res)) {
2049 dput(child);
2050 child = res;
2051 if (IS_ERR(child))
2052 goto end_instantiate;
2053 }
2054 }
2055 }
2056 inode = d_inode(child);
2057 ino = inode->i_ino;
2058 type = inode->i_mode >> 12;
2059 dput(child);
2060end_instantiate:
2061 return dir_emit(ctx, name, len, ino, type);
2062}
2063
2064/*
2065 * dname_to_vma_addr - maps a dentry name into two unsigned longs
2066 * which represent vma start and end addresses.
2067 */
2068static int dname_to_vma_addr(struct dentry *dentry,
2069 unsigned long *start, unsigned long *end)
2070{
2071 const char *str = dentry->d_name.name;
2072 unsigned long long sval, eval;
2073 unsigned int len;
2074
2075 if (str[0] == '0' && str[1] != '-')
2076 return -EINVAL;
2077 len = _parse_integer(str, 16, &sval);
2078 if (len & KSTRTOX_OVERFLOW)
2079 return -EINVAL;
2080 if (sval != (unsigned long)sval)
2081 return -EINVAL;
2082 str += len;
2083
2084 if (*str != '-')
2085 return -EINVAL;
2086 str++;
2087
2088 if (str[0] == '0' && str[1])
2089 return -EINVAL;
2090 len = _parse_integer(str, 16, &eval);
2091 if (len & KSTRTOX_OVERFLOW)
2092 return -EINVAL;
2093 if (eval != (unsigned long)eval)
2094 return -EINVAL;
2095 str += len;
2096
2097 if (*str != '\0')
2098 return -EINVAL;
2099
2100 *start = sval;
2101 *end = eval;
2102
2103 return 0;
2104}
2105
2106static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
2107{
2108 unsigned long vm_start, vm_end;
2109 bool exact_vma_exists = false;
2110 struct mm_struct *mm = NULL;
2111 struct task_struct *task;
2112 struct inode *inode;
2113 int status = 0;
2114
2115 if (flags & LOOKUP_RCU)
2116 return -ECHILD;
2117
2118 inode = d_inode(dentry);
2119 task = get_proc_task(inode);
2120 if (!task)
2121 goto out_notask;
2122
2123 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
2124 if (IS_ERR_OR_NULL(mm))
2125 goto out;
2126
2127 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2128 status = mmap_read_lock_killable(mm);
2129 if (!status) {
2130 exact_vma_exists = !!find_exact_vma(mm, vm_start,
2131 vm_end);
2132 mmap_read_unlock(mm);
2133 }
2134 }
2135
2136 mmput(mm);
2137
2138 if (exact_vma_exists) {
2139 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
2140
2141 security_task_to_inode(task, inode);
2142 status = 1;
2143 }
2144
2145out:
2146 put_task_struct(task);
2147
2148out_notask:
2149 return status;
2150}
2151
2152static const struct dentry_operations tid_map_files_dentry_operations = {
2153 .d_revalidate = map_files_d_revalidate,
2154 .d_delete = pid_delete_dentry,
2155};
2156
2157static int map_files_get_link(struct dentry *dentry, struct path *path)
2158{
2159 unsigned long vm_start, vm_end;
2160 struct vm_area_struct *vma;
2161 struct task_struct *task;
2162 struct mm_struct *mm;
2163 int rc;
2164
2165 rc = -ENOENT;
2166 task = get_proc_task(d_inode(dentry));
2167 if (!task)
2168 goto out;
2169
2170 mm = get_task_mm(task);
2171 put_task_struct(task);
2172 if (!mm)
2173 goto out;
2174
2175 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2176 if (rc)
2177 goto out_mmput;
2178
2179 rc = mmap_read_lock_killable(mm);
2180 if (rc)
2181 goto out_mmput;
2182
2183 rc = -ENOENT;
2184 vma = find_exact_vma(mm, vm_start, vm_end);
2185 if (vma && vma->vm_file) {
2186 *path = vma->vm_file->f_path;
2187 path_get(path);
2188 rc = 0;
2189 }
2190 mmap_read_unlock(mm);
2191
2192out_mmput:
2193 mmput(mm);
2194out:
2195 return rc;
2196}
2197
2198struct map_files_info {
2199 unsigned long start;
2200 unsigned long end;
2201 fmode_t mode;
2202};
2203
2204/*
2205 * Only allow CAP_SYS_ADMIN and CAP_CHECKPOINT_RESTORE to follow the links, due
2206 * to concerns about how the symlinks may be used to bypass permissions on
2207 * ancestor directories in the path to the file in question.
2208 */
2209static const char *
2210proc_map_files_get_link(struct dentry *dentry,
2211 struct inode *inode,
2212 struct delayed_call *done)
2213{
2214 if (!checkpoint_restore_ns_capable(&init_user_ns))
2215 return ERR_PTR(-EPERM);
2216
2217 return proc_pid_get_link(dentry, inode, done);
2218}
2219
2220/*
2221 * Identical to proc_pid_link_inode_operations except for get_link()
2222 */
2223static const struct inode_operations proc_map_files_link_inode_operations = {
2224 .readlink = proc_pid_readlink,
2225 .get_link = proc_map_files_get_link,
2226 .setattr = proc_setattr,
2227};
2228
2229static struct dentry *
2230proc_map_files_instantiate(struct dentry *dentry,
2231 struct task_struct *task, const void *ptr)
2232{
2233 fmode_t mode = (fmode_t)(unsigned long)ptr;
2234 struct proc_inode *ei;
2235 struct inode *inode;
2236
2237 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
2238 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2239 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2240 if (!inode)
2241 return ERR_PTR(-ENOENT);
2242
2243 ei = PROC_I(inode);
2244 ei->op.proc_get_link = map_files_get_link;
2245
2246 inode->i_op = &proc_map_files_link_inode_operations;
2247 inode->i_size = 64;
2248
2249 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2250 return d_splice_alias(inode, dentry);
2251}
2252
2253static struct dentry *proc_map_files_lookup(struct inode *dir,
2254 struct dentry *dentry, unsigned int flags)
2255{
2256 unsigned long vm_start, vm_end;
2257 struct vm_area_struct *vma;
2258 struct task_struct *task;
2259 struct dentry *result;
2260 struct mm_struct *mm;
2261
2262 result = ERR_PTR(-ENOENT);
2263 task = get_proc_task(dir);
2264 if (!task)
2265 goto out;
2266
2267 result = ERR_PTR(-EACCES);
2268 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2269 goto out_put_task;
2270
2271 result = ERR_PTR(-ENOENT);
2272 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2273 goto out_put_task;
2274
2275 mm = get_task_mm(task);
2276 if (!mm)
2277 goto out_put_task;
2278
2279 result = ERR_PTR(-EINTR);
2280 if (mmap_read_lock_killable(mm))
2281 goto out_put_mm;
2282
2283 result = ERR_PTR(-ENOENT);
2284 vma = find_exact_vma(mm, vm_start, vm_end);
2285 if (!vma)
2286 goto out_no_vma;
2287
2288 if (vma->vm_file)
2289 result = proc_map_files_instantiate(dentry, task,
2290 (void *)(unsigned long)vma->vm_file->f_mode);
2291
2292out_no_vma:
2293 mmap_read_unlock(mm);
2294out_put_mm:
2295 mmput(mm);
2296out_put_task:
2297 put_task_struct(task);
2298out:
2299 return result;
2300}
2301
2302static const struct inode_operations proc_map_files_inode_operations = {
2303 .lookup = proc_map_files_lookup,
2304 .permission = proc_fd_permission,
2305 .setattr = proc_setattr,
2306};
2307
2308static int
2309proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2310{
2311 struct vm_area_struct *vma;
2312 struct task_struct *task;
2313 struct mm_struct *mm;
2314 unsigned long nr_files, pos, i;
2315 GENRADIX(struct map_files_info) fa;
2316 struct map_files_info *p;
2317 int ret;
2318
2319 genradix_init(&fa);
2320
2321 ret = -ENOENT;
2322 task = get_proc_task(file_inode(file));
2323 if (!task)
2324 goto out;
2325
2326 ret = -EACCES;
2327 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2328 goto out_put_task;
2329
2330 ret = 0;
2331 if (!dir_emit_dots(file, ctx))
2332 goto out_put_task;
2333
2334 mm = get_task_mm(task);
2335 if (!mm)
2336 goto out_put_task;
2337
2338 ret = mmap_read_lock_killable(mm);
2339 if (ret) {
2340 mmput(mm);
2341 goto out_put_task;
2342 }
2343
2344 nr_files = 0;
2345
2346 /*
2347 * We need two passes here:
2348 *
2349 * 1) Collect vmas of mapped files with mmap_lock taken
2350 * 2) Release mmap_lock and instantiate entries
2351 *
2352 * otherwise we get lockdep complained, since filldir()
2353 * routine might require mmap_lock taken in might_fault().
2354 */
2355
2356 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2357 if (!vma->vm_file)
2358 continue;
2359 if (++pos <= ctx->pos)
2360 continue;
2361
2362 p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
2363 if (!p) {
2364 ret = -ENOMEM;
2365 mmap_read_unlock(mm);
2366 mmput(mm);
2367 goto out_put_task;
2368 }
2369
2370 p->start = vma->vm_start;
2371 p->end = vma->vm_end;
2372 p->mode = vma->vm_file->f_mode;
2373 }
2374 mmap_read_unlock(mm);
2375 mmput(mm);
2376
2377 for (i = 0; i < nr_files; i++) {
2378 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2379 unsigned int len;
2380
2381 p = genradix_ptr(&fa, i);
2382 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2383 if (!proc_fill_cache(file, ctx,
2384 buf, len,
2385 proc_map_files_instantiate,
2386 task,
2387 (void *)(unsigned long)p->mode))
2388 break;
2389 ctx->pos++;
2390 }
2391
2392out_put_task:
2393 put_task_struct(task);
2394out:
2395 genradix_free(&fa);
2396 return ret;
2397}
2398
2399static const struct file_operations proc_map_files_operations = {
2400 .read = generic_read_dir,
2401 .iterate_shared = proc_map_files_readdir,
2402 .llseek = generic_file_llseek,
2403};
2404
2405#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2406struct timers_private {
2407 struct pid *pid;
2408 struct task_struct *task;
2409 struct sighand_struct *sighand;
2410 struct pid_namespace *ns;
2411 unsigned long flags;
2412};
2413
2414static void *timers_start(struct seq_file *m, loff_t *pos)
2415{
2416 struct timers_private *tp = m->private;
2417
2418 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2419 if (!tp->task)
2420 return ERR_PTR(-ESRCH);
2421
2422 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2423 if (!tp->sighand)
2424 return ERR_PTR(-ESRCH);
2425
2426 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2427}
2428
2429static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2430{
2431 struct timers_private *tp = m->private;
2432 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2433}
2434
2435static void timers_stop(struct seq_file *m, void *v)
2436{
2437 struct timers_private *tp = m->private;
2438
2439 if (tp->sighand) {
2440 unlock_task_sighand(tp->task, &tp->flags);
2441 tp->sighand = NULL;
2442 }
2443
2444 if (tp->task) {
2445 put_task_struct(tp->task);
2446 tp->task = NULL;
2447 }
2448}
2449
2450static int show_timer(struct seq_file *m, void *v)
2451{
2452 struct k_itimer *timer;
2453 struct timers_private *tp = m->private;
2454 int notify;
2455 static const char * const nstr[] = {
2456 [SIGEV_SIGNAL] = "signal",
2457 [SIGEV_NONE] = "none",
2458 [SIGEV_THREAD] = "thread",
2459 };
2460
2461 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2462 notify = timer->it_sigev_notify;
2463
2464 seq_printf(m, "ID: %d\n", timer->it_id);
2465 seq_printf(m, "signal: %d/%px\n",
2466 timer->sigq->info.si_signo,
2467 timer->sigq->info.si_value.sival_ptr);
2468 seq_printf(m, "notify: %s/%s.%d\n",
2469 nstr[notify & ~SIGEV_THREAD_ID],
2470 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2471 pid_nr_ns(timer->it_pid, tp->ns));
2472 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2473
2474 return 0;
2475}
2476
2477static const struct seq_operations proc_timers_seq_ops = {
2478 .start = timers_start,
2479 .next = timers_next,
2480 .stop = timers_stop,
2481 .show = show_timer,
2482};
2483
2484static int proc_timers_open(struct inode *inode, struct file *file)
2485{
2486 struct timers_private *tp;
2487
2488 tp = __seq_open_private(file, &proc_timers_seq_ops,
2489 sizeof(struct timers_private));
2490 if (!tp)
2491 return -ENOMEM;
2492
2493 tp->pid = proc_pid(inode);
2494 tp->ns = proc_pid_ns(inode->i_sb);
2495 return 0;
2496}
2497
2498static const struct file_operations proc_timers_operations = {
2499 .open = proc_timers_open,
2500 .read = seq_read,
2501 .llseek = seq_lseek,
2502 .release = seq_release_private,
2503};
2504#endif
2505
2506static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2507 size_t count, loff_t *offset)
2508{
2509 struct inode *inode = file_inode(file);
2510 struct task_struct *p;
2511 u64 slack_ns;
2512 int err;
2513
2514 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2515 if (err < 0)
2516 return err;
2517
2518 p = get_proc_task(inode);
2519 if (!p)
2520 return -ESRCH;
2521
2522 if (p != current) {
2523 rcu_read_lock();
2524 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2525 rcu_read_unlock();
2526 count = -EPERM;
2527 goto out;
2528 }
2529 rcu_read_unlock();
2530
2531 err = security_task_setscheduler(p);
2532 if (err) {
2533 count = err;
2534 goto out;
2535 }
2536 }
2537
2538 task_lock(p);
2539 if (slack_ns == 0)
2540 p->timer_slack_ns = p->default_timer_slack_ns;
2541 else
2542 p->timer_slack_ns = slack_ns;
2543 task_unlock(p);
2544
2545out:
2546 put_task_struct(p);
2547
2548 return count;
2549}
2550
2551static int timerslack_ns_show(struct seq_file *m, void *v)
2552{
2553 struct inode *inode = m->private;
2554 struct task_struct *p;
2555 int err = 0;
2556
2557 p = get_proc_task(inode);
2558 if (!p)
2559 return -ESRCH;
2560
2561 if (p != current) {
2562 rcu_read_lock();
2563 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2564 rcu_read_unlock();
2565 err = -EPERM;
2566 goto out;
2567 }
2568 rcu_read_unlock();
2569
2570 err = security_task_getscheduler(p);
2571 if (err)
2572 goto out;
2573 }
2574
2575 task_lock(p);
2576 seq_printf(m, "%llu\n", p->timer_slack_ns);
2577 task_unlock(p);
2578
2579out:
2580 put_task_struct(p);
2581
2582 return err;
2583}
2584
2585static int timerslack_ns_open(struct inode *inode, struct file *filp)
2586{
2587 return single_open(filp, timerslack_ns_show, inode);
2588}
2589
2590static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2591 .open = timerslack_ns_open,
2592 .read = seq_read,
2593 .write = timerslack_ns_write,
2594 .llseek = seq_lseek,
2595 .release = single_release,
2596};
2597
2598static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2599 struct task_struct *task, const void *ptr)
2600{
2601 const struct pid_entry *p = ptr;
2602 struct inode *inode;
2603 struct proc_inode *ei;
2604
2605 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
2606 if (!inode)
2607 return ERR_PTR(-ENOENT);
2608
2609 ei = PROC_I(inode);
2610 if (S_ISDIR(inode->i_mode))
2611 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2612 if (p->iop)
2613 inode->i_op = p->iop;
2614 if (p->fop)
2615 inode->i_fop = p->fop;
2616 ei->op = p->op;
2617 pid_update_inode(task, inode);
2618 d_set_d_op(dentry, &pid_dentry_operations);
2619 return d_splice_alias(inode, dentry);
2620}
2621
2622static struct dentry *proc_pident_lookup(struct inode *dir,
2623 struct dentry *dentry,
2624 const struct pid_entry *p,
2625 const struct pid_entry *end)
2626{
2627 struct task_struct *task = get_proc_task(dir);
2628 struct dentry *res = ERR_PTR(-ENOENT);
2629
2630 if (!task)
2631 goto out_no_task;
2632
2633 /*
2634 * Yes, it does not scale. And it should not. Don't add
2635 * new entries into /proc/<tgid>/ without very good reasons.
2636 */
2637 for (; p < end; p++) {
2638 if (p->len != dentry->d_name.len)
2639 continue;
2640 if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2641 res = proc_pident_instantiate(dentry, task, p);
2642 break;
2643 }
2644 }
2645 put_task_struct(task);
2646out_no_task:
2647 return res;
2648}
2649
2650static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2651 const struct pid_entry *ents, unsigned int nents)
2652{
2653 struct task_struct *task = get_proc_task(file_inode(file));
2654 const struct pid_entry *p;
2655
2656 if (!task)
2657 return -ENOENT;
2658
2659 if (!dir_emit_dots(file, ctx))
2660 goto out;
2661
2662 if (ctx->pos >= nents + 2)
2663 goto out;
2664
2665 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2666 if (!proc_fill_cache(file, ctx, p->name, p->len,
2667 proc_pident_instantiate, task, p))
2668 break;
2669 ctx->pos++;
2670 }
2671out:
2672 put_task_struct(task);
2673 return 0;
2674}
2675
2676#ifdef CONFIG_SECURITY
2677static int proc_pid_attr_open(struct inode *inode, struct file *file)
2678{
2679 file->private_data = NULL;
2680 __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
2681 return 0;
2682}
2683
2684static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2685 size_t count, loff_t *ppos)
2686{
2687 struct inode * inode = file_inode(file);
2688 char *p = NULL;
2689 ssize_t length;
2690 struct task_struct *task = get_proc_task(inode);
2691
2692 if (!task)
2693 return -ESRCH;
2694
2695 length = security_getprocattr(task, PROC_I(inode)->op.lsm,
2696 (char*)file->f_path.dentry->d_name.name,
2697 &p);
2698 put_task_struct(task);
2699 if (length > 0)
2700 length = simple_read_from_buffer(buf, count, ppos, p, length);
2701 kfree(p);
2702 return length;
2703}
2704
2705static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2706 size_t count, loff_t *ppos)
2707{
2708 struct inode * inode = file_inode(file);
2709 struct task_struct *task;
2710 void *page;
2711 int rv;
2712
2713 /* A task may only write when it was the opener. */
2714 if (file->private_data != current->mm)
2715 return -EPERM;
2716
2717 rcu_read_lock();
2718 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2719 if (!task) {
2720 rcu_read_unlock();
2721 return -ESRCH;
2722 }
2723 /* A task may only write its own attributes. */
2724 if (current != task) {
2725 rcu_read_unlock();
2726 return -EACCES;
2727 }
2728 /* Prevent changes to overridden credentials. */
2729 if (current_cred() != current_real_cred()) {
2730 rcu_read_unlock();
2731 return -EBUSY;
2732 }
2733 rcu_read_unlock();
2734
2735 if (count > PAGE_SIZE)
2736 count = PAGE_SIZE;
2737
2738 /* No partial writes. */
2739 if (*ppos != 0)
2740 return -EINVAL;
2741
2742 page = memdup_user(buf, count);
2743 if (IS_ERR(page)) {
2744 rv = PTR_ERR(page);
2745 goto out;
2746 }
2747
2748 /* Guard against adverse ptrace interaction */
2749 rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex);
2750 if (rv < 0)
2751 goto out_free;
2752
2753 rv = security_setprocattr(PROC_I(inode)->op.lsm,
2754 file->f_path.dentry->d_name.name, page,
2755 count);
2756 mutex_unlock(¤t->signal->cred_guard_mutex);
2757out_free:
2758 kfree(page);
2759out:
2760 return rv;
2761}
2762
2763static const struct file_operations proc_pid_attr_operations = {
2764 .open = proc_pid_attr_open,
2765 .read = proc_pid_attr_read,
2766 .write = proc_pid_attr_write,
2767 .llseek = generic_file_llseek,
2768 .release = mem_release,
2769};
2770
2771#define LSM_DIR_OPS(LSM) \
2772static int proc_##LSM##_attr_dir_iterate(struct file *filp, \
2773 struct dir_context *ctx) \
2774{ \
2775 return proc_pident_readdir(filp, ctx, \
2776 LSM##_attr_dir_stuff, \
2777 ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2778} \
2779\
2780static const struct file_operations proc_##LSM##_attr_dir_ops = { \
2781 .read = generic_read_dir, \
2782 .iterate = proc_##LSM##_attr_dir_iterate, \
2783 .llseek = default_llseek, \
2784}; \
2785\
2786static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
2787 struct dentry *dentry, unsigned int flags) \
2788{ \
2789 return proc_pident_lookup(dir, dentry, \
2790 LSM##_attr_dir_stuff, \
2791 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2792} \
2793\
2794static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
2795 .lookup = proc_##LSM##_attr_dir_lookup, \
2796 .getattr = pid_getattr, \
2797 .setattr = proc_setattr, \
2798}
2799
2800#ifdef CONFIG_SECURITY_SMACK
2801static const struct pid_entry smack_attr_dir_stuff[] = {
2802 ATTR("smack", "current", 0666),
2803};
2804LSM_DIR_OPS(smack);
2805#endif
2806
2807#ifdef CONFIG_SECURITY_APPARMOR
2808static const struct pid_entry apparmor_attr_dir_stuff[] = {
2809 ATTR("apparmor", "current", 0666),
2810 ATTR("apparmor", "prev", 0444),
2811 ATTR("apparmor", "exec", 0666),
2812};
2813LSM_DIR_OPS(apparmor);
2814#endif
2815
2816static const struct pid_entry attr_dir_stuff[] = {
2817 ATTR(NULL, "current", 0666),
2818 ATTR(NULL, "prev", 0444),
2819 ATTR(NULL, "exec", 0666),
2820 ATTR(NULL, "fscreate", 0666),
2821 ATTR(NULL, "keycreate", 0666),
2822 ATTR(NULL, "sockcreate", 0666),
2823#ifdef CONFIG_SECURITY_SMACK
2824 DIR("smack", 0555,
2825 proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
2826#endif
2827#ifdef CONFIG_SECURITY_APPARMOR
2828 DIR("apparmor", 0555,
2829 proc_apparmor_attr_dir_inode_ops, proc_apparmor_attr_dir_ops),
2830#endif
2831};
2832
2833static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2834{
2835 return proc_pident_readdir(file, ctx,
2836 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2837}
2838
2839static const struct file_operations proc_attr_dir_operations = {
2840 .read = generic_read_dir,
2841 .iterate_shared = proc_attr_dir_readdir,
2842 .llseek = generic_file_llseek,
2843};
2844
2845static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2846 struct dentry *dentry, unsigned int flags)
2847{
2848 return proc_pident_lookup(dir, dentry,
2849 attr_dir_stuff,
2850 attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
2851}
2852
2853static const struct inode_operations proc_attr_dir_inode_operations = {
2854 .lookup = proc_attr_dir_lookup,
2855 .getattr = pid_getattr,
2856 .setattr = proc_setattr,
2857};
2858
2859#endif
2860
2861#ifdef CONFIG_ELF_CORE
2862static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2863 size_t count, loff_t *ppos)
2864{
2865 struct task_struct *task = get_proc_task(file_inode(file));
2866 struct mm_struct *mm;
2867 char buffer[PROC_NUMBUF];
2868 size_t len;
2869 int ret;
2870
2871 if (!task)
2872 return -ESRCH;
2873
2874 ret = 0;
2875 mm = get_task_mm(task);
2876 if (mm) {
2877 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2878 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2879 MMF_DUMP_FILTER_SHIFT));
2880 mmput(mm);
2881 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2882 }
2883
2884 put_task_struct(task);
2885
2886 return ret;
2887}
2888
2889static ssize_t proc_coredump_filter_write(struct file *file,
2890 const char __user *buf,
2891 size_t count,
2892 loff_t *ppos)
2893{
2894 struct task_struct *task;
2895 struct mm_struct *mm;
2896 unsigned int val;
2897 int ret;
2898 int i;
2899 unsigned long mask;
2900
2901 ret = kstrtouint_from_user(buf, count, 0, &val);
2902 if (ret < 0)
2903 return ret;
2904
2905 ret = -ESRCH;
2906 task = get_proc_task(file_inode(file));
2907 if (!task)
2908 goto out_no_task;
2909
2910 mm = get_task_mm(task);
2911 if (!mm)
2912 goto out_no_mm;
2913 ret = 0;
2914
2915 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2916 if (val & mask)
2917 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2918 else
2919 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2920 }
2921
2922 mmput(mm);
2923 out_no_mm:
2924 put_task_struct(task);
2925 out_no_task:
2926 if (ret < 0)
2927 return ret;
2928 return count;
2929}
2930
2931static const struct file_operations proc_coredump_filter_operations = {
2932 .read = proc_coredump_filter_read,
2933 .write = proc_coredump_filter_write,
2934 .llseek = generic_file_llseek,
2935};
2936#endif
2937
2938#ifdef CONFIG_TASK_IO_ACCOUNTING
2939static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2940{
2941 struct task_io_accounting acct = task->ioac;
2942 unsigned long flags;
2943 int result;
2944
2945 result = down_read_killable(&task->signal->exec_update_lock);
2946 if (result)
2947 return result;
2948
2949 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2950 result = -EACCES;
2951 goto out_unlock;
2952 }
2953
2954 if (whole && lock_task_sighand(task, &flags)) {
2955 struct task_struct *t = task;
2956
2957 task_io_accounting_add(&acct, &task->signal->ioac);
2958 while_each_thread(task, t)
2959 task_io_accounting_add(&acct, &t->ioac);
2960
2961 unlock_task_sighand(task, &flags);
2962 }
2963 seq_printf(m,
2964 "rchar: %llu\n"
2965 "wchar: %llu\n"
2966 "syscr: %llu\n"
2967 "syscw: %llu\n"
2968 "read_bytes: %llu\n"
2969 "write_bytes: %llu\n"
2970 "cancelled_write_bytes: %llu\n",
2971 (unsigned long long)acct.rchar,
2972 (unsigned long long)acct.wchar,
2973 (unsigned long long)acct.syscr,
2974 (unsigned long long)acct.syscw,
2975 (unsigned long long)acct.read_bytes,
2976 (unsigned long long)acct.write_bytes,
2977 (unsigned long long)acct.cancelled_write_bytes);
2978 result = 0;
2979
2980out_unlock:
2981 up_read(&task->signal->exec_update_lock);
2982 return result;
2983}
2984
2985static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2986 struct pid *pid, struct task_struct *task)
2987{
2988 return do_io_accounting(task, m, 0);
2989}
2990
2991static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2992 struct pid *pid, struct task_struct *task)
2993{
2994 return do_io_accounting(task, m, 1);
2995}
2996#endif /* CONFIG_TASK_IO_ACCOUNTING */
2997
2998#ifdef CONFIG_USER_NS
2999static int proc_id_map_open(struct inode *inode, struct file *file,
3000 const struct seq_operations *seq_ops)
3001{
3002 struct user_namespace *ns = NULL;
3003 struct task_struct *task;
3004 struct seq_file *seq;
3005 int ret = -EINVAL;
3006
3007 task = get_proc_task(inode);
3008 if (task) {
3009 rcu_read_lock();
3010 ns = get_user_ns(task_cred_xxx(task, user_ns));
3011 rcu_read_unlock();
3012 put_task_struct(task);
3013 }
3014 if (!ns)
3015 goto err;
3016
3017 ret = seq_open(file, seq_ops);
3018 if (ret)
3019 goto err_put_ns;
3020
3021 seq = file->private_data;
3022 seq->private = ns;
3023
3024 return 0;
3025err_put_ns:
3026 put_user_ns(ns);
3027err:
3028 return ret;
3029}
3030
3031static int proc_id_map_release(struct inode *inode, struct file *file)
3032{
3033 struct seq_file *seq = file->private_data;
3034 struct user_namespace *ns = seq->private;
3035 put_user_ns(ns);
3036 return seq_release(inode, file);
3037}
3038
3039static int proc_uid_map_open(struct inode *inode, struct file *file)
3040{
3041 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
3042}
3043
3044static int proc_gid_map_open(struct inode *inode, struct file *file)
3045{
3046 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
3047}
3048
3049static int proc_projid_map_open(struct inode *inode, struct file *file)
3050{
3051 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
3052}
3053
3054static const struct file_operations proc_uid_map_operations = {
3055 .open = proc_uid_map_open,
3056 .write = proc_uid_map_write,
3057 .read = seq_read,
3058 .llseek = seq_lseek,
3059 .release = proc_id_map_release,
3060};
3061
3062static const struct file_operations proc_gid_map_operations = {
3063 .open = proc_gid_map_open,
3064 .write = proc_gid_map_write,
3065 .read = seq_read,
3066 .llseek = seq_lseek,
3067 .release = proc_id_map_release,
3068};
3069
3070static const struct file_operations proc_projid_map_operations = {
3071 .open = proc_projid_map_open,
3072 .write = proc_projid_map_write,
3073 .read = seq_read,
3074 .llseek = seq_lseek,
3075 .release = proc_id_map_release,
3076};
3077
3078static int proc_setgroups_open(struct inode *inode, struct file *file)
3079{
3080 struct user_namespace *ns = NULL;
3081 struct task_struct *task;
3082 int ret;
3083
3084 ret = -ESRCH;
3085 task = get_proc_task(inode);
3086 if (task) {
3087 rcu_read_lock();
3088 ns = get_user_ns(task_cred_xxx(task, user_ns));
3089 rcu_read_unlock();
3090 put_task_struct(task);
3091 }
3092 if (!ns)
3093 goto err;
3094
3095 if (file->f_mode & FMODE_WRITE) {
3096 ret = -EACCES;
3097 if (!ns_capable(ns, CAP_SYS_ADMIN))
3098 goto err_put_ns;
3099 }
3100
3101 ret = single_open(file, &proc_setgroups_show, ns);
3102 if (ret)
3103 goto err_put_ns;
3104
3105 return 0;
3106err_put_ns:
3107 put_user_ns(ns);
3108err:
3109 return ret;
3110}
3111
3112static int proc_setgroups_release(struct inode *inode, struct file *file)
3113{
3114 struct seq_file *seq = file->private_data;
3115 struct user_namespace *ns = seq->private;
3116 int ret = single_release(inode, file);
3117 put_user_ns(ns);
3118 return ret;
3119}
3120
3121static const struct file_operations proc_setgroups_operations = {
3122 .open = proc_setgroups_open,
3123 .write = proc_setgroups_write,
3124 .read = seq_read,
3125 .llseek = seq_lseek,
3126 .release = proc_setgroups_release,
3127};
3128#endif /* CONFIG_USER_NS */
3129
3130static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
3131 struct pid *pid, struct task_struct *task)
3132{
3133 int err = lock_trace(task);
3134 if (!err) {
3135 seq_printf(m, "%08x\n", task->personality);
3136 unlock_trace(task);
3137 }
3138 return err;
3139}
3140
3141#ifdef CONFIG_LIVEPATCH
3142static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
3143 struct pid *pid, struct task_struct *task)
3144{
3145 seq_printf(m, "%d\n", task->patch_state);
3146 return 0;
3147}
3148#endif /* CONFIG_LIVEPATCH */
3149
3150#ifdef CONFIG_STACKLEAK_METRICS
3151static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
3152 struct pid *pid, struct task_struct *task)
3153{
3154 unsigned long prev_depth = THREAD_SIZE -
3155 (task->prev_lowest_stack & (THREAD_SIZE - 1));
3156 unsigned long depth = THREAD_SIZE -
3157 (task->lowest_stack & (THREAD_SIZE - 1));
3158
3159 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
3160 prev_depth, depth);
3161 return 0;
3162}
3163#endif /* CONFIG_STACKLEAK_METRICS */
3164
3165/*
3166 * Thread groups
3167 */
3168static const struct file_operations proc_task_operations;
3169static const struct inode_operations proc_task_inode_operations;
3170
3171static const struct pid_entry tgid_base_stuff[] = {
3172 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3173 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3174 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3175 DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3176 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3177#ifdef CONFIG_NET
3178 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3179#endif
3180 REG("environ", S_IRUSR, proc_environ_operations),
3181 REG("auxv", S_IRUSR, proc_auxv_operations),
3182 ONE("status", S_IRUGO, proc_pid_status),
3183 ONE("personality", S_IRUSR, proc_pid_personality),
3184 ONE("limits", S_IRUGO, proc_pid_limits),
3185#ifdef CONFIG_SCHED_DEBUG
3186 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3187#endif
3188#ifdef CONFIG_SCHED_AUTOGROUP
3189 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3190#endif
3191#ifdef CONFIG_TIME_NS
3192 REG("timens_offsets", S_IRUGO|S_IWUSR, proc_timens_offsets_operations),
3193#endif
3194 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3195#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3196 ONE("syscall", S_IRUSR, proc_pid_syscall),
3197#endif
3198 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3199 ONE("stat", S_IRUGO, proc_tgid_stat),
3200 ONE("statm", S_IRUGO, proc_pid_statm),
3201 REG("maps", S_IRUGO, proc_pid_maps_operations),
3202#ifdef CONFIG_NUMA
3203 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3204#endif
3205 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3206 LNK("cwd", proc_cwd_link),
3207 LNK("root", proc_root_link),
3208 LNK("exe", proc_exe_link),
3209 REG("mounts", S_IRUGO, proc_mounts_operations),
3210 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3211 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3212#ifdef CONFIG_PROC_PAGE_MONITOR
3213 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3214 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3215 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3216 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3217#endif
3218#ifdef CONFIG_SECURITY
3219 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3220#endif
3221#ifdef CONFIG_KALLSYMS
3222 ONE("wchan", S_IRUGO, proc_pid_wchan),
3223#endif
3224#ifdef CONFIG_STACKTRACE
3225 ONE("stack", S_IRUSR, proc_pid_stack),
3226#endif
3227#ifdef CONFIG_SCHED_INFO
3228 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3229#endif
3230#ifdef CONFIG_LATENCYTOP
3231 REG("latency", S_IRUGO, proc_lstats_operations),
3232#endif
3233#ifdef CONFIG_PROC_PID_CPUSET
3234 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3235#endif
3236#ifdef CONFIG_CGROUPS
3237 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3238#endif
3239#ifdef CONFIG_PROC_CPU_RESCTRL
3240 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3241#endif
3242 ONE("oom_score", S_IRUGO, proc_oom_score),
3243 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3244 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3245#ifdef CONFIG_AUDIT
3246 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3247 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3248#endif
3249#ifdef CONFIG_FAULT_INJECTION
3250 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3251 REG("fail-nth", 0644, proc_fail_nth_operations),
3252#endif
3253#ifdef CONFIG_ELF_CORE
3254 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3255#endif
3256#ifdef CONFIG_TASK_IO_ACCOUNTING
3257 ONE("io", S_IRUSR, proc_tgid_io_accounting),
3258#endif
3259#ifdef CONFIG_USER_NS
3260 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3261 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3262 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3263 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3264#endif
3265#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3266 REG("timers", S_IRUGO, proc_timers_operations),
3267#endif
3268 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3269#ifdef CONFIG_LIVEPATCH
3270 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3271#endif
3272#ifdef CONFIG_STACKLEAK_METRICS
3273 ONE("stack_depth", S_IRUGO, proc_stack_depth),
3274#endif
3275#ifdef CONFIG_PROC_PID_ARCH_STATUS
3276 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3277#endif
3278#ifdef CONFIG_SECCOMP_CACHE_DEBUG
3279 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3280#endif
3281};
3282
3283static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3284{
3285 return proc_pident_readdir(file, ctx,
3286 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3287}
3288
3289static const struct file_operations proc_tgid_base_operations = {
3290 .read = generic_read_dir,
3291 .iterate_shared = proc_tgid_base_readdir,
3292 .llseek = generic_file_llseek,
3293};
3294
3295struct pid *tgid_pidfd_to_pid(const struct file *file)
3296{
3297 if (file->f_op != &proc_tgid_base_operations)
3298 return ERR_PTR(-EBADF);
3299
3300 return proc_pid(file_inode(file));
3301}
3302
3303static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3304{
3305 return proc_pident_lookup(dir, dentry,
3306 tgid_base_stuff,
3307 tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
3308}
3309
3310static const struct inode_operations proc_tgid_base_inode_operations = {
3311 .lookup = proc_tgid_base_lookup,
3312 .getattr = pid_getattr,
3313 .setattr = proc_setattr,
3314 .permission = proc_pid_permission,
3315};
3316
3317/**
3318 * proc_flush_pid - Remove dcache entries for @pid from the /proc dcache.
3319 * @pid: pid that should be flushed.
3320 *
3321 * This function walks a list of inodes (that belong to any proc
3322 * filesystem) that are attached to the pid and flushes them from
3323 * the dentry cache.
3324 *
3325 * It is safe and reasonable to cache /proc entries for a task until
3326 * that task exits. After that they just clog up the dcache with
3327 * useless entries, possibly causing useful dcache entries to be
3328 * flushed instead. This routine is provided to flush those useless
3329 * dcache entries when a process is reaped.
3330 *
3331 * NOTE: This routine is just an optimization so it does not guarantee
3332 * that no dcache entries will exist after a process is reaped
3333 * it just makes it very unlikely that any will persist.
3334 */
3335
3336void proc_flush_pid(struct pid *pid)
3337{
3338 proc_invalidate_siblings_dcache(&pid->inodes, &pid->lock);
3339}
3340
3341static struct dentry *proc_pid_instantiate(struct dentry * dentry,
3342 struct task_struct *task, const void *ptr)
3343{
3344 struct inode *inode;
3345
3346 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3347 if (!inode)
3348 return ERR_PTR(-ENOENT);
3349
3350 inode->i_op = &proc_tgid_base_inode_operations;
3351 inode->i_fop = &proc_tgid_base_operations;
3352 inode->i_flags|=S_IMMUTABLE;
3353
3354 set_nlink(inode, nlink_tgid);
3355 pid_update_inode(task, inode);
3356
3357 d_set_d_op(dentry, &pid_dentry_operations);
3358 return d_splice_alias(inode, dentry);
3359}
3360
3361struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
3362{
3363 struct task_struct *task;
3364 unsigned tgid;
3365 struct proc_fs_info *fs_info;
3366 struct pid_namespace *ns;
3367 struct dentry *result = ERR_PTR(-ENOENT);
3368
3369 tgid = name_to_int(&dentry->d_name);
3370 if (tgid == ~0U)
3371 goto out;
3372
3373 fs_info = proc_sb_info(dentry->d_sb);
3374 ns = fs_info->pid_ns;
3375 rcu_read_lock();
3376 task = find_task_by_pid_ns(tgid, ns);
3377 if (task)
3378 get_task_struct(task);
3379 rcu_read_unlock();
3380 if (!task)
3381 goto out;
3382
3383 /* Limit procfs to only ptraceable tasks */
3384 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE) {
3385 if (!has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS))
3386 goto out_put_task;
3387 }
3388
3389 result = proc_pid_instantiate(dentry, task, NULL);
3390out_put_task:
3391 put_task_struct(task);
3392out:
3393 return result;
3394}
3395
3396/*
3397 * Find the first task with tgid >= tgid
3398 *
3399 */
3400struct tgid_iter {
3401 unsigned int tgid;
3402 struct task_struct *task;
3403};
3404static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3405{
3406 struct pid *pid;
3407
3408 if (iter.task)
3409 put_task_struct(iter.task);
3410 rcu_read_lock();
3411retry:
3412 iter.task = NULL;
3413 pid = find_ge_pid(iter.tgid, ns);
3414 if (pid) {
3415 iter.tgid = pid_nr_ns(pid, ns);
3416 iter.task = pid_task(pid, PIDTYPE_TGID);
3417 if (!iter.task) {
3418 iter.tgid += 1;
3419 goto retry;
3420 }
3421 get_task_struct(iter.task);
3422 }
3423 rcu_read_unlock();
3424 return iter;
3425}
3426
3427#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3428
3429/* for the /proc/ directory itself, after non-process stuff has been done */
3430int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3431{
3432 struct tgid_iter iter;
3433 struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb);
3434 struct pid_namespace *ns = proc_pid_ns(file_inode(file)->i_sb);
3435 loff_t pos = ctx->pos;
3436
3437 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3438 return 0;
3439
3440 if (pos == TGID_OFFSET - 2) {
3441 struct inode *inode = d_inode(fs_info->proc_self);
3442 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3443 return 0;
3444 ctx->pos = pos = pos + 1;
3445 }
3446 if (pos == TGID_OFFSET - 1) {
3447 struct inode *inode = d_inode(fs_info->proc_thread_self);
3448 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3449 return 0;
3450 ctx->pos = pos = pos + 1;
3451 }
3452 iter.tgid = pos - TGID_OFFSET;
3453 iter.task = NULL;
3454 for (iter = next_tgid(ns, iter);
3455 iter.task;
3456 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3457 char name[10 + 1];
3458 unsigned int len;
3459
3460 cond_resched();
3461 if (!has_pid_permissions(fs_info, iter.task, HIDEPID_INVISIBLE))
3462 continue;
3463
3464 len = snprintf(name, sizeof(name), "%u", iter.tgid);
3465 ctx->pos = iter.tgid + TGID_OFFSET;
3466 if (!proc_fill_cache(file, ctx, name, len,
3467 proc_pid_instantiate, iter.task, NULL)) {
3468 put_task_struct(iter.task);
3469 return 0;
3470 }
3471 }
3472 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3473 return 0;
3474}
3475
3476/*
3477 * proc_tid_comm_permission is a special permission function exclusively
3478 * used for the node /proc/<pid>/task/<tid>/comm.
3479 * It bypasses generic permission checks in the case where a task of the same
3480 * task group attempts to access the node.
3481 * The rationale behind this is that glibc and bionic access this node for
3482 * cross thread naming (pthread_set/getname_np(!self)). However, if
3483 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3484 * which locks out the cross thread naming implementation.
3485 * This function makes sure that the node is always accessible for members of
3486 * same thread group.
3487 */
3488static int proc_tid_comm_permission(struct user_namespace *mnt_userns,
3489 struct inode *inode, int mask)
3490{
3491 bool is_same_tgroup;
3492 struct task_struct *task;
3493
3494 task = get_proc_task(inode);
3495 if (!task)
3496 return -ESRCH;
3497 is_same_tgroup = same_thread_group(current, task);
3498 put_task_struct(task);
3499
3500 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3501 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3502 * read or written by the members of the corresponding
3503 * thread group.
3504 */
3505 return 0;
3506 }
3507
3508 return generic_permission(&init_user_ns, inode, mask);
3509}
3510
3511static const struct inode_operations proc_tid_comm_inode_operations = {
3512 .permission = proc_tid_comm_permission,
3513};
3514
3515/*
3516 * Tasks
3517 */
3518static const struct pid_entry tid_base_stuff[] = {
3519 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3520 DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3521 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3522#ifdef CONFIG_NET
3523 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3524#endif
3525 REG("environ", S_IRUSR, proc_environ_operations),
3526 REG("auxv", S_IRUSR, proc_auxv_operations),
3527 ONE("status", S_IRUGO, proc_pid_status),
3528 ONE("personality", S_IRUSR, proc_pid_personality),
3529 ONE("limits", S_IRUGO, proc_pid_limits),
3530#ifdef CONFIG_SCHED_DEBUG
3531 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3532#endif
3533 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3534 &proc_tid_comm_inode_operations,
3535 &proc_pid_set_comm_operations, {}),
3536#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3537 ONE("syscall", S_IRUSR, proc_pid_syscall),
3538#endif
3539 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3540 ONE("stat", S_IRUGO, proc_tid_stat),
3541 ONE("statm", S_IRUGO, proc_pid_statm),
3542 REG("maps", S_IRUGO, proc_pid_maps_operations),
3543#ifdef CONFIG_PROC_CHILDREN
3544 REG("children", S_IRUGO, proc_tid_children_operations),
3545#endif
3546#ifdef CONFIG_NUMA
3547 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3548#endif
3549 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3550 LNK("cwd", proc_cwd_link),
3551 LNK("root", proc_root_link),
3552 LNK("exe", proc_exe_link),
3553 REG("mounts", S_IRUGO, proc_mounts_operations),
3554 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3555#ifdef CONFIG_PROC_PAGE_MONITOR
3556 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3557 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3558 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3559 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3560#endif
3561#ifdef CONFIG_SECURITY
3562 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3563#endif
3564#ifdef CONFIG_KALLSYMS
3565 ONE("wchan", S_IRUGO, proc_pid_wchan),
3566#endif
3567#ifdef CONFIG_STACKTRACE
3568 ONE("stack", S_IRUSR, proc_pid_stack),
3569#endif
3570#ifdef CONFIG_SCHED_INFO
3571 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3572#endif
3573#ifdef CONFIG_LATENCYTOP
3574 REG("latency", S_IRUGO, proc_lstats_operations),
3575#endif
3576#ifdef CONFIG_PROC_PID_CPUSET
3577 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3578#endif
3579#ifdef CONFIG_CGROUPS
3580 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3581#endif
3582#ifdef CONFIG_PROC_CPU_RESCTRL
3583 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3584#endif
3585 ONE("oom_score", S_IRUGO, proc_oom_score),
3586 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3587 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3588#ifdef CONFIG_AUDIT
3589 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3590 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3591#endif
3592#ifdef CONFIG_FAULT_INJECTION
3593 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3594 REG("fail-nth", 0644, proc_fail_nth_operations),
3595#endif
3596#ifdef CONFIG_TASK_IO_ACCOUNTING
3597 ONE("io", S_IRUSR, proc_tid_io_accounting),
3598#endif
3599#ifdef CONFIG_USER_NS
3600 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3601 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3602 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3603 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3604#endif
3605#ifdef CONFIG_LIVEPATCH
3606 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3607#endif
3608#ifdef CONFIG_PROC_PID_ARCH_STATUS
3609 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3610#endif
3611#ifdef CONFIG_SECCOMP_CACHE_DEBUG
3612 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3613#endif
3614};
3615
3616static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3617{
3618 return proc_pident_readdir(file, ctx,
3619 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3620}
3621
3622static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3623{
3624 return proc_pident_lookup(dir, dentry,
3625 tid_base_stuff,
3626 tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
3627}
3628
3629static const struct file_operations proc_tid_base_operations = {
3630 .read = generic_read_dir,
3631 .iterate_shared = proc_tid_base_readdir,
3632 .llseek = generic_file_llseek,
3633};
3634
3635static const struct inode_operations proc_tid_base_inode_operations = {
3636 .lookup = proc_tid_base_lookup,
3637 .getattr = pid_getattr,
3638 .setattr = proc_setattr,
3639};
3640
3641static struct dentry *proc_task_instantiate(struct dentry *dentry,
3642 struct task_struct *task, const void *ptr)
3643{
3644 struct inode *inode;
3645 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3646 if (!inode)
3647 return ERR_PTR(-ENOENT);
3648
3649 inode->i_op = &proc_tid_base_inode_operations;
3650 inode->i_fop = &proc_tid_base_operations;
3651 inode->i_flags |= S_IMMUTABLE;
3652
3653 set_nlink(inode, nlink_tid);
3654 pid_update_inode(task, inode);
3655
3656 d_set_d_op(dentry, &pid_dentry_operations);
3657 return d_splice_alias(inode, dentry);
3658}
3659
3660static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3661{
3662 struct task_struct *task;
3663 struct task_struct *leader = get_proc_task(dir);
3664 unsigned tid;
3665 struct proc_fs_info *fs_info;
3666 struct pid_namespace *ns;
3667 struct dentry *result = ERR_PTR(-ENOENT);
3668
3669 if (!leader)
3670 goto out_no_task;
3671
3672 tid = name_to_int(&dentry->d_name);
3673 if (tid == ~0U)
3674 goto out;
3675
3676 fs_info = proc_sb_info(dentry->d_sb);
3677 ns = fs_info->pid_ns;
3678 rcu_read_lock();
3679 task = find_task_by_pid_ns(tid, ns);
3680 if (task)
3681 get_task_struct(task);
3682 rcu_read_unlock();
3683 if (!task)
3684 goto out;
3685 if (!same_thread_group(leader, task))
3686 goto out_drop_task;
3687
3688 result = proc_task_instantiate(dentry, task, NULL);
3689out_drop_task:
3690 put_task_struct(task);
3691out:
3692 put_task_struct(leader);
3693out_no_task:
3694 return result;
3695}
3696
3697/*
3698 * Find the first tid of a thread group to return to user space.
3699 *
3700 * Usually this is just the thread group leader, but if the users
3701 * buffer was too small or there was a seek into the middle of the
3702 * directory we have more work todo.
3703 *
3704 * In the case of a short read we start with find_task_by_pid.
3705 *
3706 * In the case of a seek we start with the leader and walk nr
3707 * threads past it.
3708 */
3709static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3710 struct pid_namespace *ns)
3711{
3712 struct task_struct *pos, *task;
3713 unsigned long nr = f_pos;
3714
3715 if (nr != f_pos) /* 32bit overflow? */
3716 return NULL;
3717
3718 rcu_read_lock();
3719 task = pid_task(pid, PIDTYPE_PID);
3720 if (!task)
3721 goto fail;
3722
3723 /* Attempt to start with the tid of a thread */
3724 if (tid && nr) {
3725 pos = find_task_by_pid_ns(tid, ns);
3726 if (pos && same_thread_group(pos, task))
3727 goto found;
3728 }
3729
3730 /* If nr exceeds the number of threads there is nothing todo */
3731 if (nr >= get_nr_threads(task))
3732 goto fail;
3733
3734 /* If we haven't found our starting place yet start
3735 * with the leader and walk nr threads forward.
3736 */
3737 pos = task = task->group_leader;
3738 do {
3739 if (!nr--)
3740 goto found;
3741 } while_each_thread(task, pos);
3742fail:
3743 pos = NULL;
3744 goto out;
3745found:
3746 get_task_struct(pos);
3747out:
3748 rcu_read_unlock();
3749 return pos;
3750}
3751
3752/*
3753 * Find the next thread in the thread list.
3754 * Return NULL if there is an error or no next thread.
3755 *
3756 * The reference to the input task_struct is released.
3757 */
3758static struct task_struct *next_tid(struct task_struct *start)
3759{
3760 struct task_struct *pos = NULL;
3761 rcu_read_lock();
3762 if (pid_alive(start)) {
3763 pos = next_thread(start);
3764 if (thread_group_leader(pos))
3765 pos = NULL;
3766 else
3767 get_task_struct(pos);
3768 }
3769 rcu_read_unlock();
3770 put_task_struct(start);
3771 return pos;
3772}
3773
3774/* for the /proc/TGID/task/ directories */
3775static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3776{
3777 struct inode *inode = file_inode(file);
3778 struct task_struct *task;
3779 struct pid_namespace *ns;
3780 int tid;
3781
3782 if (proc_inode_is_dead(inode))
3783 return -ENOENT;
3784
3785 if (!dir_emit_dots(file, ctx))
3786 return 0;
3787
3788 /* f_version caches the tgid value that the last readdir call couldn't
3789 * return. lseek aka telldir automagically resets f_version to 0.
3790 */
3791 ns = proc_pid_ns(inode->i_sb);
3792 tid = (int)file->f_version;
3793 file->f_version = 0;
3794 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3795 task;
3796 task = next_tid(task), ctx->pos++) {
3797 char name[10 + 1];
3798 unsigned int len;
3799 tid = task_pid_nr_ns(task, ns);
3800 len = snprintf(name, sizeof(name), "%u", tid);
3801 if (!proc_fill_cache(file, ctx, name, len,
3802 proc_task_instantiate, task, NULL)) {
3803 /* returning this tgid failed, save it as the first
3804 * pid for the next readir call */
3805 file->f_version = (u64)tid;
3806 put_task_struct(task);
3807 break;
3808 }
3809 }
3810
3811 return 0;
3812}
3813
3814static int proc_task_getattr(struct user_namespace *mnt_userns,
3815 const struct path *path, struct kstat *stat,
3816 u32 request_mask, unsigned int query_flags)
3817{
3818 struct inode *inode = d_inode(path->dentry);
3819 struct task_struct *p = get_proc_task(inode);
3820 generic_fillattr(&init_user_ns, inode, stat);
3821
3822 if (p) {
3823 stat->nlink += get_nr_threads(p);
3824 put_task_struct(p);
3825 }
3826
3827 return 0;
3828}
3829
3830static const struct inode_operations proc_task_inode_operations = {
3831 .lookup = proc_task_lookup,
3832 .getattr = proc_task_getattr,
3833 .setattr = proc_setattr,
3834 .permission = proc_pid_permission,
3835};
3836
3837static const struct file_operations proc_task_operations = {
3838 .read = generic_read_dir,
3839 .iterate_shared = proc_task_readdir,
3840 .llseek = generic_file_llseek,
3841};
3842
3843void __init set_proc_pid_nlink(void)
3844{
3845 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3846 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3847}