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