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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/stacktrace.h>
71 #include <linux/resource.h>
72 #include <linux/module.h>
73 #include <linux/mount.h>
74 #include <linux/security.h>
75 #include <linux/ptrace.h>
76 #include <linux/tracehook.h>
77 #include <linux/printk.h>
78 #include <linux/cache.h>
79 #include <linux/cgroup.h>
80 #include <linux/cpuset.h>
81 #include <linux/audit.h>
82 #include <linux/poll.h>
83 #include <linux/nsproxy.h>
84 #include <linux/oom.h>
85 #include <linux/elf.h>
86 #include <linux/pid_namespace.h>
87 #include <linux/user_namespace.h>
88 #include <linux/fs_struct.h>
89 #include <linux/slab.h>
90 #include <linux/sched/autogroup.h>
91 #include <linux/sched/mm.h>
92 #include <linux/sched/coredump.h>
93 #include <linux/sched/debug.h>
94 #include <linux/sched/stat.h>
95 #include <linux/posix-timers.h>
96 #include <linux/time_namespace.h>
97 #include <linux/resctrl.h>
98 #include <linux/cn_proc.h>
99 #include <trace/events/oom.h>
100 #include "internal.h"
101 #include "fd.h"
102
103 #include "../../lib/kstrtox.h"
104
105 /* NOTE:
106 * Implementing inode permission operations in /proc is almost
107 * certainly an error. Permission checks need to happen during
108 * each system call not at open time. The reason is that most of
109 * what we wish to check for permissions in /proc varies at runtime.
110 *
111 * The classic example of a problem is opening file descriptors
112 * in /proc for a task before it execs a suid executable.
113 */
114
115 static u8 nlink_tid __ro_after_init;
116 static u8 nlink_tgid __ro_after_init;
117
118 struct 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 */
157 static 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
172 static 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
185 static 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
202 static 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 */
218 static 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
255 static 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
342 static 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
357 static 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
375 static 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 */
385 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
386 struct pid *pid, struct task_struct *task)
387 {
388 unsigned long wchan;
389
390 if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
391 wchan = get_wchan(task);
392 else
393 wchan = 0;
394
395 if (wchan)
396 seq_printf(m, "%ps", (void *) wchan);
397 else
398 seq_putc(m, '0');
399
400 return 0;
401 }
402 #endif /* CONFIG_KALLSYMS */
403
404 static int lock_trace(struct task_struct *task)
405 {
406 int err = down_read_killable(&task->signal->exec_update_lock);
407 if (err)
408 return err;
409 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
410 up_read(&task->signal->exec_update_lock);
411 return -EPERM;
412 }
413 return 0;
414 }
415
416 static void unlock_trace(struct task_struct *task)
417 {
418 up_read(&task->signal->exec_update_lock);
419 }
420
421 #ifdef CONFIG_STACKTRACE
422
423 #define MAX_STACK_TRACE_DEPTH 64
424
425 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
426 struct pid *pid, struct task_struct *task)
427 {
428 unsigned long *entries;
429 int err;
430
431 /*
432 * The ability to racily run the kernel stack unwinder on a running task
433 * and then observe the unwinder output is scary; while it is useful for
434 * debugging kernel issues, it can also allow an attacker to leak kernel
435 * stack contents.
436 * Doing this in a manner that is at least safe from races would require
437 * some work to ensure that the remote task can not be scheduled; and
438 * even then, this would still expose the unwinder as local attack
439 * surface.
440 * Therefore, this interface is restricted to root.
441 */
442 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
443 return -EACCES;
444
445 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
446 GFP_KERNEL);
447 if (!entries)
448 return -ENOMEM;
449
450 err = lock_trace(task);
451 if (!err) {
452 unsigned int i, nr_entries;
453
454 nr_entries = stack_trace_save_tsk(task, entries,
455 MAX_STACK_TRACE_DEPTH, 0);
456
457 for (i = 0; i < nr_entries; i++) {
458 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
459 }
460
461 unlock_trace(task);
462 }
463 kfree(entries);
464
465 return err;
466 }
467 #endif
468
469 #ifdef CONFIG_SCHED_INFO
470 /*
471 * Provides /proc/PID/schedstat
472 */
473 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
474 struct pid *pid, struct task_struct *task)
475 {
476 if (unlikely(!sched_info_on()))
477 seq_puts(m, "0 0 0\n");
478 else
479 seq_printf(m, "%llu %llu %lu\n",
480 (unsigned long long)task->se.sum_exec_runtime,
481 (unsigned long long)task->sched_info.run_delay,
482 task->sched_info.pcount);
483
484 return 0;
485 }
486 #endif
487
488 #ifdef CONFIG_LATENCYTOP
489 static int lstats_show_proc(struct seq_file *m, void *v)
490 {
491 int i;
492 struct inode *inode = m->private;
493 struct task_struct *task = get_proc_task(inode);
494
495 if (!task)
496 return -ESRCH;
497 seq_puts(m, "Latency Top version : v0.1\n");
498 for (i = 0; i < LT_SAVECOUNT; i++) {
499 struct latency_record *lr = &task->latency_record[i];
500 if (lr->backtrace[0]) {
501 int q;
502 seq_printf(m, "%i %li %li",
503 lr->count, lr->time, lr->max);
504 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
505 unsigned long bt = lr->backtrace[q];
506
507 if (!bt)
508 break;
509 seq_printf(m, " %ps", (void *)bt);
510 }
511 seq_putc(m, '\n');
512 }
513
514 }
515 put_task_struct(task);
516 return 0;
517 }
518
519 static int lstats_open(struct inode *inode, struct file *file)
520 {
521 return single_open(file, lstats_show_proc, inode);
522 }
523
524 static ssize_t lstats_write(struct file *file, const char __user *buf,
525 size_t count, loff_t *offs)
526 {
527 struct task_struct *task = get_proc_task(file_inode(file));
528
529 if (!task)
530 return -ESRCH;
531 clear_tsk_latency_tracing(task);
532 put_task_struct(task);
533
534 return count;
535 }
536
537 static const struct file_operations proc_lstats_operations = {
538 .open = lstats_open,
539 .read = seq_read,
540 .write = lstats_write,
541 .llseek = seq_lseek,
542 .release = single_release,
543 };
544
545 #endif
546
547 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
548 struct pid *pid, struct task_struct *task)
549 {
550 unsigned long totalpages = totalram_pages() + total_swap_pages;
551 unsigned long points = 0;
552 long badness;
553
554 badness = oom_badness(task, totalpages);
555 /*
556 * Special case OOM_SCORE_ADJ_MIN for all others scale the
557 * badness value into [0, 2000] range which we have been
558 * exporting for a long time so userspace might depend on it.
559 */
560 if (badness != LONG_MIN)
561 points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3;
562
563 seq_printf(m, "%lu\n", points);
564
565 return 0;
566 }
567
568 struct limit_names {
569 const char *name;
570 const char *unit;
571 };
572
573 static const struct limit_names lnames[RLIM_NLIMITS] = {
574 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
575 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
576 [RLIMIT_DATA] = {"Max data size", "bytes"},
577 [RLIMIT_STACK] = {"Max stack size", "bytes"},
578 [RLIMIT_CORE] = {"Max core file size", "bytes"},
579 [RLIMIT_RSS] = {"Max resident set", "bytes"},
580 [RLIMIT_NPROC] = {"Max processes", "processes"},
581 [RLIMIT_NOFILE] = {"Max open files", "files"},
582 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
583 [RLIMIT_AS] = {"Max address space", "bytes"},
584 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
585 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
586 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
587 [RLIMIT_NICE] = {"Max nice priority", NULL},
588 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
589 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
590 };
591
592 /* Display limits for a process */
593 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
594 struct pid *pid, struct task_struct *task)
595 {
596 unsigned int i;
597 unsigned long flags;
598
599 struct rlimit rlim[RLIM_NLIMITS];
600
601 if (!lock_task_sighand(task, &flags))
602 return 0;
603 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
604 unlock_task_sighand(task, &flags);
605
606 /*
607 * print the file header
608 */
609 seq_puts(m, "Limit "
610 "Soft Limit "
611 "Hard Limit "
612 "Units \n");
613
614 for (i = 0; i < RLIM_NLIMITS; i++) {
615 if (rlim[i].rlim_cur == RLIM_INFINITY)
616 seq_printf(m, "%-25s %-20s ",
617 lnames[i].name, "unlimited");
618 else
619 seq_printf(m, "%-25s %-20lu ",
620 lnames[i].name, rlim[i].rlim_cur);
621
622 if (rlim[i].rlim_max == RLIM_INFINITY)
623 seq_printf(m, "%-20s ", "unlimited");
624 else
625 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
626
627 if (lnames[i].unit)
628 seq_printf(m, "%-10s\n", lnames[i].unit);
629 else
630 seq_putc(m, '\n');
631 }
632
633 return 0;
634 }
635
636 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
637 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
638 struct pid *pid, struct task_struct *task)
639 {
640 struct syscall_info info;
641 u64 *args = &info.data.args[0];
642 int res;
643
644 res = lock_trace(task);
645 if (res)
646 return res;
647
648 if (task_current_syscall(task, &info))
649 seq_puts(m, "running\n");
650 else if (info.data.nr < 0)
651 seq_printf(m, "%d 0x%llx 0x%llx\n",
652 info.data.nr, info.sp, info.data.instruction_pointer);
653 else
654 seq_printf(m,
655 "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
656 info.data.nr,
657 args[0], args[1], args[2], args[3], args[4], args[5],
658 info.sp, info.data.instruction_pointer);
659 unlock_trace(task);
660
661 return 0;
662 }
663 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
664
665 /************************************************************************/
666 /* Here the fs part begins */
667 /************************************************************************/
668
669 /* permission checks */
670 static int proc_fd_access_allowed(struct inode *inode)
671 {
672 struct task_struct *task;
673 int allowed = 0;
674 /* Allow access to a task's file descriptors if it is us or we
675 * may use ptrace attach to the process and find out that
676 * information.
677 */
678 task = get_proc_task(inode);
679 if (task) {
680 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
681 put_task_struct(task);
682 }
683 return allowed;
684 }
685
686 int proc_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
687 struct iattr *attr)
688 {
689 int error;
690 struct inode *inode = d_inode(dentry);
691
692 if (attr->ia_valid & ATTR_MODE)
693 return -EPERM;
694
695 error = setattr_prepare(&init_user_ns, dentry, attr);
696 if (error)
697 return error;
698
699 setattr_copy(&init_user_ns, inode, attr);
700 mark_inode_dirty(inode);
701 return 0;
702 }
703
704 /*
705 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
706 * or euid/egid (for hide_pid_min=2)?
707 */
708 static bool has_pid_permissions(struct proc_fs_info *fs_info,
709 struct task_struct *task,
710 enum proc_hidepid hide_pid_min)
711 {
712 /*
713 * If 'hidpid' mount option is set force a ptrace check,
714 * we indicate that we are using a filesystem syscall
715 * by passing PTRACE_MODE_READ_FSCREDS
716 */
717 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE)
718 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
719
720 if (fs_info->hide_pid < hide_pid_min)
721 return true;
722 if (in_group_p(fs_info->pid_gid))
723 return true;
724 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
725 }
726
727
728 static int proc_pid_permission(struct user_namespace *mnt_userns,
729 struct inode *inode, int mask)
730 {
731 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
732 struct task_struct *task;
733 bool has_perms;
734
735 task = get_proc_task(inode);
736 if (!task)
737 return -ESRCH;
738 has_perms = has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS);
739 put_task_struct(task);
740
741 if (!has_perms) {
742 if (fs_info->hide_pid == HIDEPID_INVISIBLE) {
743 /*
744 * Let's make getdents(), stat(), and open()
745 * consistent with each other. If a process
746 * may not stat() a file, it shouldn't be seen
747 * in procfs at all.
748 */
749 return -ENOENT;
750 }
751
752 return -EPERM;
753 }
754 return generic_permission(&init_user_ns, inode, mask);
755 }
756
757
758
759 static const struct inode_operations proc_def_inode_operations = {
760 .setattr = proc_setattr,
761 };
762
763 static 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
781 static int proc_single_open(struct inode *inode, struct file *filp)
782 {
783 return single_open(filp, proc_single_show, inode);
784 }
785
786 static 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
794 struct 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
814 static 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
825 static 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
835 static ssize_t mem_rw(struct file *file, char __user *buf,
836 size_t count, loff_t *ppos, int write)
837 {
838 struct mm_struct *mm = file->private_data;
839 unsigned long addr = *ppos;
840 ssize_t copied;
841 char *page;
842 unsigned int flags;
843
844 if (!mm)
845 return 0;
846
847 page = (char *)__get_free_page(GFP_KERNEL);
848 if (!page)
849 return -ENOMEM;
850
851 copied = 0;
852 if (!mmget_not_zero(mm))
853 goto free;
854
855 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
856
857 while (count > 0) {
858 size_t this_len = min_t(size_t, count, PAGE_SIZE);
859
860 if (write && copy_from_user(page, buf, this_len)) {
861 copied = -EFAULT;
862 break;
863 }
864
865 this_len = access_remote_vm(mm, addr, page, this_len, flags);
866 if (!this_len) {
867 if (!copied)
868 copied = -EIO;
869 break;
870 }
871
872 if (!write && copy_to_user(buf, page, this_len)) {
873 copied = -EFAULT;
874 break;
875 }
876
877 buf += this_len;
878 addr += this_len;
879 copied += this_len;
880 count -= this_len;
881 }
882 *ppos = addr;
883
884 mmput(mm);
885 free:
886 free_page((unsigned long) page);
887 return copied;
888 }
889
890 static 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
896 static 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
902 loff_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
918 static 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
926 static 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
934 static int environ_open(struct inode *inode, struct file *file)
935 {
936 return __mem_open(inode, file, PTRACE_MODE_READ);
937 }
938
939 static 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
997 free:
998 free_page((unsigned long) page);
999 return ret;
1000 }
1001
1002 static 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
1009 static int auxv_open(struct inode *inode, struct file *file)
1010 {
1011 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1012 }
1013
1014 static 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
1029 static 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
1036 static 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
1058 static 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 }
1135 err_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 */
1151 static 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);
1185 out:
1186 return err < 0 ? err : count;
1187 }
1188
1189 static 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
1195 static 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
1211 static 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);
1236 out:
1237 return err < 0 ? err : count;
1238 }
1239
1240 static 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
1248 static 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
1265 static 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
1308 static const struct file_operations proc_loginuid_operations = {
1309 .read = proc_loginuid_read,
1310 .write = proc_loginuid_write,
1311 .llseek = generic_file_llseek,
1312 };
1313
1314 static 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
1330 static 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
1337 static 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
1355 static 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
1385 static 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
1391 static 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
1411 static 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
1426 static 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 */
1437 static 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
1453 static ssize_t
1454 sched_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
1470 static int sched_open(struct inode *inode, struct file *filp)
1471 {
1472 return single_open(filp, sched_show, inode);
1473 }
1474
1475 static 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 */
1489 static 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
1504 static ssize_t
1505 sched_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
1537 static 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
1550 static 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
1561 static 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
1575 static 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;
1643 out:
1644 kfree(kbuf);
1645 return ret;
1646 }
1647
1648 static int timens_offsets_open(struct inode *inode, struct file *filp)
1649 {
1650 return single_open(filp, timens_offsets_show, inode);
1651 }
1652
1653 static 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
1662 static ssize_t comm_write(struct file *file, const char __user *buf,
1663 size_t count, loff_t *offset)
1664 {
1665 struct inode *inode = file_inode(file);
1666 struct task_struct *p;
1667 char buffer[TASK_COMM_LEN];
1668 const size_t maxlen = sizeof(buffer) - 1;
1669
1670 memset(buffer, 0, sizeof(buffer));
1671 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1672 return -EFAULT;
1673
1674 p = get_proc_task(inode);
1675 if (!p)
1676 return -ESRCH;
1677
1678 if (same_thread_group(current, p)) {
1679 set_task_comm(p, buffer);
1680 proc_comm_connector(p);
1681 }
1682 else
1683 count = -EINVAL;
1684
1685 put_task_struct(p);
1686
1687 return count;
1688 }
1689
1690 static int comm_show(struct seq_file *m, void *v)
1691 {
1692 struct inode *inode = m->private;
1693 struct task_struct *p;
1694
1695 p = get_proc_task(inode);
1696 if (!p)
1697 return -ESRCH;
1698
1699 proc_task_name(m, p, false);
1700 seq_putc(m, '\n');
1701
1702 put_task_struct(p);
1703
1704 return 0;
1705 }
1706
1707 static int comm_open(struct inode *inode, struct file *filp)
1708 {
1709 return single_open(filp, comm_show, inode);
1710 }
1711
1712 static const struct file_operations proc_pid_set_comm_operations = {
1713 .open = comm_open,
1714 .read = seq_read,
1715 .write = comm_write,
1716 .llseek = seq_lseek,
1717 .release = single_release,
1718 };
1719
1720 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1721 {
1722 struct task_struct *task;
1723 struct file *exe_file;
1724
1725 task = get_proc_task(d_inode(dentry));
1726 if (!task)
1727 return -ENOENT;
1728 exe_file = get_task_exe_file(task);
1729 put_task_struct(task);
1730 if (exe_file) {
1731 *exe_path = exe_file->f_path;
1732 path_get(&exe_file->f_path);
1733 fput(exe_file);
1734 return 0;
1735 } else
1736 return -ENOENT;
1737 }
1738
1739 static const char *proc_pid_get_link(struct dentry *dentry,
1740 struct inode *inode,
1741 struct delayed_call *done)
1742 {
1743 struct path path;
1744 int error = -EACCES;
1745
1746 if (!dentry)
1747 return ERR_PTR(-ECHILD);
1748
1749 /* Are we allowed to snoop on the tasks file descriptors? */
1750 if (!proc_fd_access_allowed(inode))
1751 goto out;
1752
1753 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1754 if (error)
1755 goto out;
1756
1757 error = nd_jump_link(&path);
1758 out:
1759 return ERR_PTR(error);
1760 }
1761
1762 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1763 {
1764 char *tmp = (char *)__get_free_page(GFP_KERNEL);
1765 char *pathname;
1766 int len;
1767
1768 if (!tmp)
1769 return -ENOMEM;
1770
1771 pathname = d_path(path, tmp, PAGE_SIZE);
1772 len = PTR_ERR(pathname);
1773 if (IS_ERR(pathname))
1774 goto out;
1775 len = tmp + PAGE_SIZE - 1 - pathname;
1776
1777 if (len > buflen)
1778 len = buflen;
1779 if (copy_to_user(buffer, pathname, len))
1780 len = -EFAULT;
1781 out:
1782 free_page((unsigned long)tmp);
1783 return len;
1784 }
1785
1786 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1787 {
1788 int error = -EACCES;
1789 struct inode *inode = d_inode(dentry);
1790 struct path path;
1791
1792 /* Are we allowed to snoop on the tasks file descriptors? */
1793 if (!proc_fd_access_allowed(inode))
1794 goto out;
1795
1796 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1797 if (error)
1798 goto out;
1799
1800 error = do_proc_readlink(&path, buffer, buflen);
1801 path_put(&path);
1802 out:
1803 return error;
1804 }
1805
1806 const struct inode_operations proc_pid_link_inode_operations = {
1807 .readlink = proc_pid_readlink,
1808 .get_link = proc_pid_get_link,
1809 .setattr = proc_setattr,
1810 };
1811
1812
1813 /* building an inode */
1814
1815 void task_dump_owner(struct task_struct *task, umode_t mode,
1816 kuid_t *ruid, kgid_t *rgid)
1817 {
1818 /* Depending on the state of dumpable compute who should own a
1819 * proc file for a task.
1820 */
1821 const struct cred *cred;
1822 kuid_t uid;
1823 kgid_t gid;
1824
1825 if (unlikely(task->flags & PF_KTHREAD)) {
1826 *ruid = GLOBAL_ROOT_UID;
1827 *rgid = GLOBAL_ROOT_GID;
1828 return;
1829 }
1830
1831 /* Default to the tasks effective ownership */
1832 rcu_read_lock();
1833 cred = __task_cred(task);
1834 uid = cred->euid;
1835 gid = cred->egid;
1836 rcu_read_unlock();
1837
1838 /*
1839 * Before the /proc/pid/status file was created the only way to read
1840 * the effective uid of a /process was to stat /proc/pid. Reading
1841 * /proc/pid/status is slow enough that procps and other packages
1842 * kept stating /proc/pid. To keep the rules in /proc simple I have
1843 * made this apply to all per process world readable and executable
1844 * directories.
1845 */
1846 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1847 struct mm_struct *mm;
1848 task_lock(task);
1849 mm = task->mm;
1850 /* Make non-dumpable tasks owned by some root */
1851 if (mm) {
1852 if (get_dumpable(mm) != SUID_DUMP_USER) {
1853 struct user_namespace *user_ns = mm->user_ns;
1854
1855 uid = make_kuid(user_ns, 0);
1856 if (!uid_valid(uid))
1857 uid = GLOBAL_ROOT_UID;
1858
1859 gid = make_kgid(user_ns, 0);
1860 if (!gid_valid(gid))
1861 gid = GLOBAL_ROOT_GID;
1862 }
1863 } else {
1864 uid = GLOBAL_ROOT_UID;
1865 gid = GLOBAL_ROOT_GID;
1866 }
1867 task_unlock(task);
1868 }
1869 *ruid = uid;
1870 *rgid = gid;
1871 }
1872
1873 void proc_pid_evict_inode(struct proc_inode *ei)
1874 {
1875 struct pid *pid = ei->pid;
1876
1877 if (S_ISDIR(ei->vfs_inode.i_mode)) {
1878 spin_lock(&pid->lock);
1879 hlist_del_init_rcu(&ei->sibling_inodes);
1880 spin_unlock(&pid->lock);
1881 }
1882
1883 put_pid(pid);
1884 }
1885
1886 struct inode *proc_pid_make_inode(struct super_block * sb,
1887 struct task_struct *task, umode_t mode)
1888 {
1889 struct inode * inode;
1890 struct proc_inode *ei;
1891 struct pid *pid;
1892
1893 /* We need a new inode */
1894
1895 inode = new_inode(sb);
1896 if (!inode)
1897 goto out;
1898
1899 /* Common stuff */
1900 ei = PROC_I(inode);
1901 inode->i_mode = mode;
1902 inode->i_ino = get_next_ino();
1903 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1904 inode->i_op = &proc_def_inode_operations;
1905
1906 /*
1907 * grab the reference to task.
1908 */
1909 pid = get_task_pid(task, PIDTYPE_PID);
1910 if (!pid)
1911 goto out_unlock;
1912
1913 /* Let the pid remember us for quick removal */
1914 ei->pid = pid;
1915 if (S_ISDIR(mode)) {
1916 spin_lock(&pid->lock);
1917 hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes);
1918 spin_unlock(&pid->lock);
1919 }
1920
1921 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1922 security_task_to_inode(task, inode);
1923
1924 out:
1925 return inode;
1926
1927 out_unlock:
1928 iput(inode);
1929 return NULL;
1930 }
1931
1932 int pid_getattr(struct user_namespace *mnt_userns, const struct path *path,
1933 struct kstat *stat, u32 request_mask, unsigned int query_flags)
1934 {
1935 struct inode *inode = d_inode(path->dentry);
1936 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
1937 struct task_struct *task;
1938
1939 generic_fillattr(&init_user_ns, inode, stat);
1940
1941 stat->uid = GLOBAL_ROOT_UID;
1942 stat->gid = GLOBAL_ROOT_GID;
1943 rcu_read_lock();
1944 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1945 if (task) {
1946 if (!has_pid_permissions(fs_info, task, HIDEPID_INVISIBLE)) {
1947 rcu_read_unlock();
1948 /*
1949 * This doesn't prevent learning whether PID exists,
1950 * it only makes getattr() consistent with readdir().
1951 */
1952 return -ENOENT;
1953 }
1954 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1955 }
1956 rcu_read_unlock();
1957 return 0;
1958 }
1959
1960 /* dentry stuff */
1961
1962 /*
1963 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
1964 */
1965 void pid_update_inode(struct task_struct *task, struct inode *inode)
1966 {
1967 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1968
1969 inode->i_mode &= ~(S_ISUID | S_ISGID);
1970 security_task_to_inode(task, inode);
1971 }
1972
1973 /*
1974 * Rewrite the inode's ownerships here because the owning task may have
1975 * performed a setuid(), etc.
1976 *
1977 */
1978 static int pid_revalidate(struct dentry *dentry, unsigned int flags)
1979 {
1980 struct inode *inode;
1981 struct task_struct *task;
1982
1983 if (flags & LOOKUP_RCU)
1984 return -ECHILD;
1985
1986 inode = d_inode(dentry);
1987 task = get_proc_task(inode);
1988
1989 if (task) {
1990 pid_update_inode(task, inode);
1991 put_task_struct(task);
1992 return 1;
1993 }
1994 return 0;
1995 }
1996
1997 static inline bool proc_inode_is_dead(struct inode *inode)
1998 {
1999 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
2000 }
2001
2002 int pid_delete_dentry(const struct dentry *dentry)
2003 {
2004 /* Is the task we represent dead?
2005 * If so, then don't put the dentry on the lru list,
2006 * kill it immediately.
2007 */
2008 return proc_inode_is_dead(d_inode(dentry));
2009 }
2010
2011 const struct dentry_operations pid_dentry_operations =
2012 {
2013 .d_revalidate = pid_revalidate,
2014 .d_delete = pid_delete_dentry,
2015 };
2016
2017 /* Lookups */
2018
2019 /*
2020 * Fill a directory entry.
2021 *
2022 * If possible create the dcache entry and derive our inode number and
2023 * file type from dcache entry.
2024 *
2025 * Since all of the proc inode numbers are dynamically generated, the inode
2026 * numbers do not exist until the inode is cache. This means creating
2027 * the dcache entry in readdir is necessary to keep the inode numbers
2028 * reported by readdir in sync with the inode numbers reported
2029 * by stat.
2030 */
2031 bool proc_fill_cache(struct file *file, struct dir_context *ctx,
2032 const char *name, unsigned int len,
2033 instantiate_t instantiate, struct task_struct *task, const void *ptr)
2034 {
2035 struct dentry *child, *dir = file->f_path.dentry;
2036 struct qstr qname = QSTR_INIT(name, len);
2037 struct inode *inode;
2038 unsigned type = DT_UNKNOWN;
2039 ino_t ino = 1;
2040
2041 child = d_hash_and_lookup(dir, &qname);
2042 if (!child) {
2043 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
2044 child = d_alloc_parallel(dir, &qname, &wq);
2045 if (IS_ERR(child))
2046 goto end_instantiate;
2047 if (d_in_lookup(child)) {
2048 struct dentry *res;
2049 res = instantiate(child, task, ptr);
2050 d_lookup_done(child);
2051 if (unlikely(res)) {
2052 dput(child);
2053 child = res;
2054 if (IS_ERR(child))
2055 goto end_instantiate;
2056 }
2057 }
2058 }
2059 inode = d_inode(child);
2060 ino = inode->i_ino;
2061 type = inode->i_mode >> 12;
2062 dput(child);
2063 end_instantiate:
2064 return dir_emit(ctx, name, len, ino, type);
2065 }
2066
2067 /*
2068 * dname_to_vma_addr - maps a dentry name into two unsigned longs
2069 * which represent vma start and end addresses.
2070 */
2071 static int dname_to_vma_addr(struct dentry *dentry,
2072 unsigned long *start, unsigned long *end)
2073 {
2074 const char *str = dentry->d_name.name;
2075 unsigned long long sval, eval;
2076 unsigned int len;
2077
2078 if (str[0] == '0' && str[1] != '-')
2079 return -EINVAL;
2080 len = _parse_integer(str, 16, &sval);
2081 if (len & KSTRTOX_OVERFLOW)
2082 return -EINVAL;
2083 if (sval != (unsigned long)sval)
2084 return -EINVAL;
2085 str += len;
2086
2087 if (*str != '-')
2088 return -EINVAL;
2089 str++;
2090
2091 if (str[0] == '0' && str[1])
2092 return -EINVAL;
2093 len = _parse_integer(str, 16, &eval);
2094 if (len & KSTRTOX_OVERFLOW)
2095 return -EINVAL;
2096 if (eval != (unsigned long)eval)
2097 return -EINVAL;
2098 str += len;
2099
2100 if (*str != '\0')
2101 return -EINVAL;
2102
2103 *start = sval;
2104 *end = eval;
2105
2106 return 0;
2107 }
2108
2109 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
2110 {
2111 unsigned long vm_start, vm_end;
2112 bool exact_vma_exists = false;
2113 struct mm_struct *mm = NULL;
2114 struct task_struct *task;
2115 struct inode *inode;
2116 int status = 0;
2117
2118 if (flags & LOOKUP_RCU)
2119 return -ECHILD;
2120
2121 inode = d_inode(dentry);
2122 task = get_proc_task(inode);
2123 if (!task)
2124 goto out_notask;
2125
2126 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
2127 if (IS_ERR_OR_NULL(mm))
2128 goto out;
2129
2130 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2131 status = mmap_read_lock_killable(mm);
2132 if (!status) {
2133 exact_vma_exists = !!find_exact_vma(mm, vm_start,
2134 vm_end);
2135 mmap_read_unlock(mm);
2136 }
2137 }
2138
2139 mmput(mm);
2140
2141 if (exact_vma_exists) {
2142 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
2143
2144 security_task_to_inode(task, inode);
2145 status = 1;
2146 }
2147
2148 out:
2149 put_task_struct(task);
2150
2151 out_notask:
2152 return status;
2153 }
2154
2155 static const struct dentry_operations tid_map_files_dentry_operations = {
2156 .d_revalidate = map_files_d_revalidate,
2157 .d_delete = pid_delete_dentry,
2158 };
2159
2160 static int map_files_get_link(struct dentry *dentry, struct path *path)
2161 {
2162 unsigned long vm_start, vm_end;
2163 struct vm_area_struct *vma;
2164 struct task_struct *task;
2165 struct mm_struct *mm;
2166 int rc;
2167
2168 rc = -ENOENT;
2169 task = get_proc_task(d_inode(dentry));
2170 if (!task)
2171 goto out;
2172
2173 mm = get_task_mm(task);
2174 put_task_struct(task);
2175 if (!mm)
2176 goto out;
2177
2178 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2179 if (rc)
2180 goto out_mmput;
2181
2182 rc = mmap_read_lock_killable(mm);
2183 if (rc)
2184 goto out_mmput;
2185
2186 rc = -ENOENT;
2187 vma = find_exact_vma(mm, vm_start, vm_end);
2188 if (vma && vma->vm_file) {
2189 *path = vma->vm_file->f_path;
2190 path_get(path);
2191 rc = 0;
2192 }
2193 mmap_read_unlock(mm);
2194
2195 out_mmput:
2196 mmput(mm);
2197 out:
2198 return rc;
2199 }
2200
2201 struct map_files_info {
2202 unsigned long start;
2203 unsigned long end;
2204 fmode_t mode;
2205 };
2206
2207 /*
2208 * Only allow CAP_SYS_ADMIN and CAP_CHECKPOINT_RESTORE to follow the links, due
2209 * to concerns about how the symlinks may be used to bypass permissions on
2210 * ancestor directories in the path to the file in question.
2211 */
2212 static const char *
2213 proc_map_files_get_link(struct dentry *dentry,
2214 struct inode *inode,
2215 struct delayed_call *done)
2216 {
2217 if (!checkpoint_restore_ns_capable(&init_user_ns))
2218 return ERR_PTR(-EPERM);
2219
2220 return proc_pid_get_link(dentry, inode, done);
2221 }
2222
2223 /*
2224 * Identical to proc_pid_link_inode_operations except for get_link()
2225 */
2226 static const struct inode_operations proc_map_files_link_inode_operations = {
2227 .readlink = proc_pid_readlink,
2228 .get_link = proc_map_files_get_link,
2229 .setattr = proc_setattr,
2230 };
2231
2232 static struct dentry *
2233 proc_map_files_instantiate(struct dentry *dentry,
2234 struct task_struct *task, const void *ptr)
2235 {
2236 fmode_t mode = (fmode_t)(unsigned long)ptr;
2237 struct proc_inode *ei;
2238 struct inode *inode;
2239
2240 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
2241 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2242 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2243 if (!inode)
2244 return ERR_PTR(-ENOENT);
2245
2246 ei = PROC_I(inode);
2247 ei->op.proc_get_link = map_files_get_link;
2248
2249 inode->i_op = &proc_map_files_link_inode_operations;
2250 inode->i_size = 64;
2251
2252 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2253 return d_splice_alias(inode, dentry);
2254 }
2255
2256 static struct dentry *proc_map_files_lookup(struct inode *dir,
2257 struct dentry *dentry, unsigned int flags)
2258 {
2259 unsigned long vm_start, vm_end;
2260 struct vm_area_struct *vma;
2261 struct task_struct *task;
2262 struct dentry *result;
2263 struct mm_struct *mm;
2264
2265 result = ERR_PTR(-ENOENT);
2266 task = get_proc_task(dir);
2267 if (!task)
2268 goto out;
2269
2270 result = ERR_PTR(-EACCES);
2271 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2272 goto out_put_task;
2273
2274 result = ERR_PTR(-ENOENT);
2275 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2276 goto out_put_task;
2277
2278 mm = get_task_mm(task);
2279 if (!mm)
2280 goto out_put_task;
2281
2282 result = ERR_PTR(-EINTR);
2283 if (mmap_read_lock_killable(mm))
2284 goto out_put_mm;
2285
2286 result = ERR_PTR(-ENOENT);
2287 vma = find_exact_vma(mm, vm_start, vm_end);
2288 if (!vma)
2289 goto out_no_vma;
2290
2291 if (vma->vm_file)
2292 result = proc_map_files_instantiate(dentry, task,
2293 (void *)(unsigned long)vma->vm_file->f_mode);
2294
2295 out_no_vma:
2296 mmap_read_unlock(mm);
2297 out_put_mm:
2298 mmput(mm);
2299 out_put_task:
2300 put_task_struct(task);
2301 out:
2302 return result;
2303 }
2304
2305 static const struct inode_operations proc_map_files_inode_operations = {
2306 .lookup = proc_map_files_lookup,
2307 .permission = proc_fd_permission,
2308 .setattr = proc_setattr,
2309 };
2310
2311 static int
2312 proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2313 {
2314 struct vm_area_struct *vma;
2315 struct task_struct *task;
2316 struct mm_struct *mm;
2317 unsigned long nr_files, pos, i;
2318 GENRADIX(struct map_files_info) fa;
2319 struct map_files_info *p;
2320 int ret;
2321
2322 genradix_init(&fa);
2323
2324 ret = -ENOENT;
2325 task = get_proc_task(file_inode(file));
2326 if (!task)
2327 goto out;
2328
2329 ret = -EACCES;
2330 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2331 goto out_put_task;
2332
2333 ret = 0;
2334 if (!dir_emit_dots(file, ctx))
2335 goto out_put_task;
2336
2337 mm = get_task_mm(task);
2338 if (!mm)
2339 goto out_put_task;
2340
2341 ret = mmap_read_lock_killable(mm);
2342 if (ret) {
2343 mmput(mm);
2344 goto out_put_task;
2345 }
2346
2347 nr_files = 0;
2348
2349 /*
2350 * We need two passes here:
2351 *
2352 * 1) Collect vmas of mapped files with mmap_lock taken
2353 * 2) Release mmap_lock and instantiate entries
2354 *
2355 * otherwise we get lockdep complained, since filldir()
2356 * routine might require mmap_lock taken in might_fault().
2357 */
2358
2359 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2360 if (!vma->vm_file)
2361 continue;
2362 if (++pos <= ctx->pos)
2363 continue;
2364
2365 p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
2366 if (!p) {
2367 ret = -ENOMEM;
2368 mmap_read_unlock(mm);
2369 mmput(mm);
2370 goto out_put_task;
2371 }
2372
2373 p->start = vma->vm_start;
2374 p->end = vma->vm_end;
2375 p->mode = vma->vm_file->f_mode;
2376 }
2377 mmap_read_unlock(mm);
2378 mmput(mm);
2379
2380 for (i = 0; i < nr_files; i++) {
2381 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2382 unsigned int len;
2383
2384 p = genradix_ptr(&fa, i);
2385 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2386 if (!proc_fill_cache(file, ctx,
2387 buf, len,
2388 proc_map_files_instantiate,
2389 task,
2390 (void *)(unsigned long)p->mode))
2391 break;
2392 ctx->pos++;
2393 }
2394
2395 out_put_task:
2396 put_task_struct(task);
2397 out:
2398 genradix_free(&fa);
2399 return ret;
2400 }
2401
2402 static const struct file_operations proc_map_files_operations = {
2403 .read = generic_read_dir,
2404 .iterate_shared = proc_map_files_readdir,
2405 .llseek = generic_file_llseek,
2406 };
2407
2408 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2409 struct timers_private {
2410 struct pid *pid;
2411 struct task_struct *task;
2412 struct sighand_struct *sighand;
2413 struct pid_namespace *ns;
2414 unsigned long flags;
2415 };
2416
2417 static void *timers_start(struct seq_file *m, loff_t *pos)
2418 {
2419 struct timers_private *tp = m->private;
2420
2421 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2422 if (!tp->task)
2423 return ERR_PTR(-ESRCH);
2424
2425 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2426 if (!tp->sighand)
2427 return ERR_PTR(-ESRCH);
2428
2429 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2430 }
2431
2432 static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2433 {
2434 struct timers_private *tp = m->private;
2435 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2436 }
2437
2438 static void timers_stop(struct seq_file *m, void *v)
2439 {
2440 struct timers_private *tp = m->private;
2441
2442 if (tp->sighand) {
2443 unlock_task_sighand(tp->task, &tp->flags);
2444 tp->sighand = NULL;
2445 }
2446
2447 if (tp->task) {
2448 put_task_struct(tp->task);
2449 tp->task = NULL;
2450 }
2451 }
2452
2453 static int show_timer(struct seq_file *m, void *v)
2454 {
2455 struct k_itimer *timer;
2456 struct timers_private *tp = m->private;
2457 int notify;
2458 static const char * const nstr[] = {
2459 [SIGEV_SIGNAL] = "signal",
2460 [SIGEV_NONE] = "none",
2461 [SIGEV_THREAD] = "thread",
2462 };
2463
2464 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2465 notify = timer->it_sigev_notify;
2466
2467 seq_printf(m, "ID: %d\n", timer->it_id);
2468 seq_printf(m, "signal: %d/%px\n",
2469 timer->sigq->info.si_signo,
2470 timer->sigq->info.si_value.sival_ptr);
2471 seq_printf(m, "notify: %s/%s.%d\n",
2472 nstr[notify & ~SIGEV_THREAD_ID],
2473 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2474 pid_nr_ns(timer->it_pid, tp->ns));
2475 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2476
2477 return 0;
2478 }
2479
2480 static const struct seq_operations proc_timers_seq_ops = {
2481 .start = timers_start,
2482 .next = timers_next,
2483 .stop = timers_stop,
2484 .show = show_timer,
2485 };
2486
2487 static int proc_timers_open(struct inode *inode, struct file *file)
2488 {
2489 struct timers_private *tp;
2490
2491 tp = __seq_open_private(file, &proc_timers_seq_ops,
2492 sizeof(struct timers_private));
2493 if (!tp)
2494 return -ENOMEM;
2495
2496 tp->pid = proc_pid(inode);
2497 tp->ns = proc_pid_ns(inode->i_sb);
2498 return 0;
2499 }
2500
2501 static const struct file_operations proc_timers_operations = {
2502 .open = proc_timers_open,
2503 .read = seq_read,
2504 .llseek = seq_lseek,
2505 .release = seq_release_private,
2506 };
2507 #endif
2508
2509 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2510 size_t count, loff_t *offset)
2511 {
2512 struct inode *inode = file_inode(file);
2513 struct task_struct *p;
2514 u64 slack_ns;
2515 int err;
2516
2517 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2518 if (err < 0)
2519 return err;
2520
2521 p = get_proc_task(inode);
2522 if (!p)
2523 return -ESRCH;
2524
2525 if (p != current) {
2526 rcu_read_lock();
2527 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2528 rcu_read_unlock();
2529 count = -EPERM;
2530 goto out;
2531 }
2532 rcu_read_unlock();
2533
2534 err = security_task_setscheduler(p);
2535 if (err) {
2536 count = err;
2537 goto out;
2538 }
2539 }
2540
2541 task_lock(p);
2542 if (slack_ns == 0)
2543 p->timer_slack_ns = p->default_timer_slack_ns;
2544 else
2545 p->timer_slack_ns = slack_ns;
2546 task_unlock(p);
2547
2548 out:
2549 put_task_struct(p);
2550
2551 return count;
2552 }
2553
2554 static int timerslack_ns_show(struct seq_file *m, void *v)
2555 {
2556 struct inode *inode = m->private;
2557 struct task_struct *p;
2558 int err = 0;
2559
2560 p = get_proc_task(inode);
2561 if (!p)
2562 return -ESRCH;
2563
2564 if (p != current) {
2565 rcu_read_lock();
2566 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2567 rcu_read_unlock();
2568 err = -EPERM;
2569 goto out;
2570 }
2571 rcu_read_unlock();
2572
2573 err = security_task_getscheduler(p);
2574 if (err)
2575 goto out;
2576 }
2577
2578 task_lock(p);
2579 seq_printf(m, "%llu\n", p->timer_slack_ns);
2580 task_unlock(p);
2581
2582 out:
2583 put_task_struct(p);
2584
2585 return err;
2586 }
2587
2588 static int timerslack_ns_open(struct inode *inode, struct file *filp)
2589 {
2590 return single_open(filp, timerslack_ns_show, inode);
2591 }
2592
2593 static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2594 .open = timerslack_ns_open,
2595 .read = seq_read,
2596 .write = timerslack_ns_write,
2597 .llseek = seq_lseek,
2598 .release = single_release,
2599 };
2600
2601 static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2602 struct task_struct *task, const void *ptr)
2603 {
2604 const struct pid_entry *p = ptr;
2605 struct inode *inode;
2606 struct proc_inode *ei;
2607
2608 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
2609 if (!inode)
2610 return ERR_PTR(-ENOENT);
2611
2612 ei = PROC_I(inode);
2613 if (S_ISDIR(inode->i_mode))
2614 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2615 if (p->iop)
2616 inode->i_op = p->iop;
2617 if (p->fop)
2618 inode->i_fop = p->fop;
2619 ei->op = p->op;
2620 pid_update_inode(task, inode);
2621 d_set_d_op(dentry, &pid_dentry_operations);
2622 return d_splice_alias(inode, dentry);
2623 }
2624
2625 static struct dentry *proc_pident_lookup(struct inode *dir,
2626 struct dentry *dentry,
2627 const struct pid_entry *p,
2628 const struct pid_entry *end)
2629 {
2630 struct task_struct *task = get_proc_task(dir);
2631 struct dentry *res = ERR_PTR(-ENOENT);
2632
2633 if (!task)
2634 goto out_no_task;
2635
2636 /*
2637 * Yes, it does not scale. And it should not. Don't add
2638 * new entries into /proc/<tgid>/ without very good reasons.
2639 */
2640 for (; p < end; p++) {
2641 if (p->len != dentry->d_name.len)
2642 continue;
2643 if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2644 res = proc_pident_instantiate(dentry, task, p);
2645 break;
2646 }
2647 }
2648 put_task_struct(task);
2649 out_no_task:
2650 return res;
2651 }
2652
2653 static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2654 const struct pid_entry *ents, unsigned int nents)
2655 {
2656 struct task_struct *task = get_proc_task(file_inode(file));
2657 const struct pid_entry *p;
2658
2659 if (!task)
2660 return -ENOENT;
2661
2662 if (!dir_emit_dots(file, ctx))
2663 goto out;
2664
2665 if (ctx->pos >= nents + 2)
2666 goto out;
2667
2668 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2669 if (!proc_fill_cache(file, ctx, p->name, p->len,
2670 proc_pident_instantiate, task, p))
2671 break;
2672 ctx->pos++;
2673 }
2674 out:
2675 put_task_struct(task);
2676 return 0;
2677 }
2678
2679 #ifdef CONFIG_SECURITY
2680 static int proc_pid_attr_open(struct inode *inode, struct file *file)
2681 {
2682 file->private_data = NULL;
2683 __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
2684 return 0;
2685 }
2686
2687 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2688 size_t count, loff_t *ppos)
2689 {
2690 struct inode * inode = file_inode(file);
2691 char *p = NULL;
2692 ssize_t length;
2693 struct task_struct *task = get_proc_task(inode);
2694
2695 if (!task)
2696 return -ESRCH;
2697
2698 length = security_getprocattr(task, PROC_I(inode)->op.lsm,
2699 (char*)file->f_path.dentry->d_name.name,
2700 &p);
2701 put_task_struct(task);
2702 if (length > 0)
2703 length = simple_read_from_buffer(buf, count, ppos, p, length);
2704 kfree(p);
2705 return length;
2706 }
2707
2708 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2709 size_t count, loff_t *ppos)
2710 {
2711 struct inode * inode = file_inode(file);
2712 struct task_struct *task;
2713 void *page;
2714 int rv;
2715
2716 /* A task may only write when it was the opener. */
2717 if (file->private_data != current->mm)
2718 return -EPERM;
2719
2720 rcu_read_lock();
2721 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2722 if (!task) {
2723 rcu_read_unlock();
2724 return -ESRCH;
2725 }
2726 /* A task may only write its own attributes. */
2727 if (current != task) {
2728 rcu_read_unlock();
2729 return -EACCES;
2730 }
2731 /* Prevent changes to overridden credentials. */
2732 if (current_cred() != current_real_cred()) {
2733 rcu_read_unlock();
2734 return -EBUSY;
2735 }
2736 rcu_read_unlock();
2737
2738 if (count > PAGE_SIZE)
2739 count = PAGE_SIZE;
2740
2741 /* No partial writes. */
2742 if (*ppos != 0)
2743 return -EINVAL;
2744
2745 page = memdup_user(buf, count);
2746 if (IS_ERR(page)) {
2747 rv = PTR_ERR(page);
2748 goto out;
2749 }
2750
2751 /* Guard against adverse ptrace interaction */
2752 rv = mutex_lock_interruptible(&current->signal->cred_guard_mutex);
2753 if (rv < 0)
2754 goto out_free;
2755
2756 rv = security_setprocattr(PROC_I(inode)->op.lsm,
2757 file->f_path.dentry->d_name.name, page,
2758 count);
2759 mutex_unlock(&current->signal->cred_guard_mutex);
2760 out_free:
2761 kfree(page);
2762 out:
2763 return rv;
2764 }
2765
2766 static const struct file_operations proc_pid_attr_operations = {
2767 .open = proc_pid_attr_open,
2768 .read = proc_pid_attr_read,
2769 .write = proc_pid_attr_write,
2770 .llseek = generic_file_llseek,
2771 .release = mem_release,
2772 };
2773
2774 #define LSM_DIR_OPS(LSM) \
2775 static int proc_##LSM##_attr_dir_iterate(struct file *filp, \
2776 struct dir_context *ctx) \
2777 { \
2778 return proc_pident_readdir(filp, ctx, \
2779 LSM##_attr_dir_stuff, \
2780 ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2781 } \
2782 \
2783 static const struct file_operations proc_##LSM##_attr_dir_ops = { \
2784 .read = generic_read_dir, \
2785 .iterate = proc_##LSM##_attr_dir_iterate, \
2786 .llseek = default_llseek, \
2787 }; \
2788 \
2789 static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
2790 struct dentry *dentry, unsigned int flags) \
2791 { \
2792 return proc_pident_lookup(dir, dentry, \
2793 LSM##_attr_dir_stuff, \
2794 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2795 } \
2796 \
2797 static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
2798 .lookup = proc_##LSM##_attr_dir_lookup, \
2799 .getattr = pid_getattr, \
2800 .setattr = proc_setattr, \
2801 }
2802
2803 #ifdef CONFIG_SECURITY_SMACK
2804 static const struct pid_entry smack_attr_dir_stuff[] = {
2805 ATTR("smack", "current", 0666),
2806 };
2807 LSM_DIR_OPS(smack);
2808 #endif
2809
2810 #ifdef CONFIG_SECURITY_APPARMOR
2811 static const struct pid_entry apparmor_attr_dir_stuff[] = {
2812 ATTR("apparmor", "current", 0666),
2813 ATTR("apparmor", "prev", 0444),
2814 ATTR("apparmor", "exec", 0666),
2815 };
2816 LSM_DIR_OPS(apparmor);
2817 #endif
2818
2819 static const struct pid_entry attr_dir_stuff[] = {
2820 ATTR(NULL, "current", 0666),
2821 ATTR(NULL, "prev", 0444),
2822 ATTR(NULL, "exec", 0666),
2823 ATTR(NULL, "fscreate", 0666),
2824 ATTR(NULL, "keycreate", 0666),
2825 ATTR(NULL, "sockcreate", 0666),
2826 #ifdef CONFIG_SECURITY_SMACK
2827 DIR("smack", 0555,
2828 proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
2829 #endif
2830 #ifdef CONFIG_SECURITY_APPARMOR
2831 DIR("apparmor", 0555,
2832 proc_apparmor_attr_dir_inode_ops, proc_apparmor_attr_dir_ops),
2833 #endif
2834 };
2835
2836 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2837 {
2838 return proc_pident_readdir(file, ctx,
2839 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2840 }
2841
2842 static const struct file_operations proc_attr_dir_operations = {
2843 .read = generic_read_dir,
2844 .iterate_shared = proc_attr_dir_readdir,
2845 .llseek = generic_file_llseek,
2846 };
2847
2848 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2849 struct dentry *dentry, unsigned int flags)
2850 {
2851 return proc_pident_lookup(dir, dentry,
2852 attr_dir_stuff,
2853 attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
2854 }
2855
2856 static const struct inode_operations proc_attr_dir_inode_operations = {
2857 .lookup = proc_attr_dir_lookup,
2858 .getattr = pid_getattr,
2859 .setattr = proc_setattr,
2860 };
2861
2862 #endif
2863
2864 #ifdef CONFIG_ELF_CORE
2865 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2866 size_t count, loff_t *ppos)
2867 {
2868 struct task_struct *task = get_proc_task(file_inode(file));
2869 struct mm_struct *mm;
2870 char buffer[PROC_NUMBUF];
2871 size_t len;
2872 int ret;
2873
2874 if (!task)
2875 return -ESRCH;
2876
2877 ret = 0;
2878 mm = get_task_mm(task);
2879 if (mm) {
2880 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2881 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2882 MMF_DUMP_FILTER_SHIFT));
2883 mmput(mm);
2884 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2885 }
2886
2887 put_task_struct(task);
2888
2889 return ret;
2890 }
2891
2892 static ssize_t proc_coredump_filter_write(struct file *file,
2893 const char __user *buf,
2894 size_t count,
2895 loff_t *ppos)
2896 {
2897 struct task_struct *task;
2898 struct mm_struct *mm;
2899 unsigned int val;
2900 int ret;
2901 int i;
2902 unsigned long mask;
2903
2904 ret = kstrtouint_from_user(buf, count, 0, &val);
2905 if (ret < 0)
2906 return ret;
2907
2908 ret = -ESRCH;
2909 task = get_proc_task(file_inode(file));
2910 if (!task)
2911 goto out_no_task;
2912
2913 mm = get_task_mm(task);
2914 if (!mm)
2915 goto out_no_mm;
2916 ret = 0;
2917
2918 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2919 if (val & mask)
2920 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2921 else
2922 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2923 }
2924
2925 mmput(mm);
2926 out_no_mm:
2927 put_task_struct(task);
2928 out_no_task:
2929 if (ret < 0)
2930 return ret;
2931 return count;
2932 }
2933
2934 static const struct file_operations proc_coredump_filter_operations = {
2935 .read = proc_coredump_filter_read,
2936 .write = proc_coredump_filter_write,
2937 .llseek = generic_file_llseek,
2938 };
2939 #endif
2940
2941 #ifdef CONFIG_TASK_IO_ACCOUNTING
2942 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2943 {
2944 struct task_io_accounting acct = task->ioac;
2945 unsigned long flags;
2946 int result;
2947
2948 result = down_read_killable(&task->signal->exec_update_lock);
2949 if (result)
2950 return result;
2951
2952 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2953 result = -EACCES;
2954 goto out_unlock;
2955 }
2956
2957 if (whole && lock_task_sighand(task, &flags)) {
2958 struct task_struct *t = task;
2959
2960 task_io_accounting_add(&acct, &task->signal->ioac);
2961 while_each_thread(task, t)
2962 task_io_accounting_add(&acct, &t->ioac);
2963
2964 unlock_task_sighand(task, &flags);
2965 }
2966 seq_printf(m,
2967 "rchar: %llu\n"
2968 "wchar: %llu\n"
2969 "syscr: %llu\n"
2970 "syscw: %llu\n"
2971 "read_bytes: %llu\n"
2972 "write_bytes: %llu\n"
2973 "cancelled_write_bytes: %llu\n",
2974 (unsigned long long)acct.rchar,
2975 (unsigned long long)acct.wchar,
2976 (unsigned long long)acct.syscr,
2977 (unsigned long long)acct.syscw,
2978 (unsigned long long)acct.read_bytes,
2979 (unsigned long long)acct.write_bytes,
2980 (unsigned long long)acct.cancelled_write_bytes);
2981 result = 0;
2982
2983 out_unlock:
2984 up_read(&task->signal->exec_update_lock);
2985 return result;
2986 }
2987
2988 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2989 struct pid *pid, struct task_struct *task)
2990 {
2991 return do_io_accounting(task, m, 0);
2992 }
2993
2994 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2995 struct pid *pid, struct task_struct *task)
2996 {
2997 return do_io_accounting(task, m, 1);
2998 }
2999 #endif /* CONFIG_TASK_IO_ACCOUNTING */
3000
3001 #ifdef CONFIG_USER_NS
3002 static int proc_id_map_open(struct inode *inode, struct file *file,
3003 const struct seq_operations *seq_ops)
3004 {
3005 struct user_namespace *ns = NULL;
3006 struct task_struct *task;
3007 struct seq_file *seq;
3008 int ret = -EINVAL;
3009
3010 task = get_proc_task(inode);
3011 if (task) {
3012 rcu_read_lock();
3013 ns = get_user_ns(task_cred_xxx(task, user_ns));
3014 rcu_read_unlock();
3015 put_task_struct(task);
3016 }
3017 if (!ns)
3018 goto err;
3019
3020 ret = seq_open(file, seq_ops);
3021 if (ret)
3022 goto err_put_ns;
3023
3024 seq = file->private_data;
3025 seq->private = ns;
3026
3027 return 0;
3028 err_put_ns:
3029 put_user_ns(ns);
3030 err:
3031 return ret;
3032 }
3033
3034 static int proc_id_map_release(struct inode *inode, struct file *file)
3035 {
3036 struct seq_file *seq = file->private_data;
3037 struct user_namespace *ns = seq->private;
3038 put_user_ns(ns);
3039 return seq_release(inode, file);
3040 }
3041
3042 static int proc_uid_map_open(struct inode *inode, struct file *file)
3043 {
3044 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
3045 }
3046
3047 static int proc_gid_map_open(struct inode *inode, struct file *file)
3048 {
3049 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
3050 }
3051
3052 static int proc_projid_map_open(struct inode *inode, struct file *file)
3053 {
3054 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
3055 }
3056
3057 static const struct file_operations proc_uid_map_operations = {
3058 .open = proc_uid_map_open,
3059 .write = proc_uid_map_write,
3060 .read = seq_read,
3061 .llseek = seq_lseek,
3062 .release = proc_id_map_release,
3063 };
3064
3065 static const struct file_operations proc_gid_map_operations = {
3066 .open = proc_gid_map_open,
3067 .write = proc_gid_map_write,
3068 .read = seq_read,
3069 .llseek = seq_lseek,
3070 .release = proc_id_map_release,
3071 };
3072
3073 static const struct file_operations proc_projid_map_operations = {
3074 .open = proc_projid_map_open,
3075 .write = proc_projid_map_write,
3076 .read = seq_read,
3077 .llseek = seq_lseek,
3078 .release = proc_id_map_release,
3079 };
3080
3081 static int proc_setgroups_open(struct inode *inode, struct file *file)
3082 {
3083 struct user_namespace *ns = NULL;
3084 struct task_struct *task;
3085 int ret;
3086
3087 ret = -ESRCH;
3088 task = get_proc_task(inode);
3089 if (task) {
3090 rcu_read_lock();
3091 ns = get_user_ns(task_cred_xxx(task, user_ns));
3092 rcu_read_unlock();
3093 put_task_struct(task);
3094 }
3095 if (!ns)
3096 goto err;
3097
3098 if (file->f_mode & FMODE_WRITE) {
3099 ret = -EACCES;
3100 if (!ns_capable(ns, CAP_SYS_ADMIN))
3101 goto err_put_ns;
3102 }
3103
3104 ret = single_open(file, &proc_setgroups_show, ns);
3105 if (ret)
3106 goto err_put_ns;
3107
3108 return 0;
3109 err_put_ns:
3110 put_user_ns(ns);
3111 err:
3112 return ret;
3113 }
3114
3115 static int proc_setgroups_release(struct inode *inode, struct file *file)
3116 {
3117 struct seq_file *seq = file->private_data;
3118 struct user_namespace *ns = seq->private;
3119 int ret = single_release(inode, file);
3120 put_user_ns(ns);
3121 return ret;
3122 }
3123
3124 static const struct file_operations proc_setgroups_operations = {
3125 .open = proc_setgroups_open,
3126 .write = proc_setgroups_write,
3127 .read = seq_read,
3128 .llseek = seq_lseek,
3129 .release = proc_setgroups_release,
3130 };
3131 #endif /* CONFIG_USER_NS */
3132
3133 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
3134 struct pid *pid, struct task_struct *task)
3135 {
3136 int err = lock_trace(task);
3137 if (!err) {
3138 seq_printf(m, "%08x\n", task->personality);
3139 unlock_trace(task);
3140 }
3141 return err;
3142 }
3143
3144 #ifdef CONFIG_LIVEPATCH
3145 static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
3146 struct pid *pid, struct task_struct *task)
3147 {
3148 seq_printf(m, "%d\n", task->patch_state);
3149 return 0;
3150 }
3151 #endif /* CONFIG_LIVEPATCH */
3152
3153 #ifdef CONFIG_STACKLEAK_METRICS
3154 static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
3155 struct pid *pid, struct task_struct *task)
3156 {
3157 unsigned long prev_depth = THREAD_SIZE -
3158 (task->prev_lowest_stack & (THREAD_SIZE - 1));
3159 unsigned long depth = THREAD_SIZE -
3160 (task->lowest_stack & (THREAD_SIZE - 1));
3161
3162 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
3163 prev_depth, depth);
3164 return 0;
3165 }
3166 #endif /* CONFIG_STACKLEAK_METRICS */
3167
3168 /*
3169 * Thread groups
3170 */
3171 static const struct file_operations proc_task_operations;
3172 static const struct inode_operations proc_task_inode_operations;
3173
3174 static const struct pid_entry tgid_base_stuff[] = {
3175 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3176 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3177 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3178 DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3179 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3180 #ifdef CONFIG_NET
3181 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3182 #endif
3183 REG("environ", S_IRUSR, proc_environ_operations),
3184 REG("auxv", S_IRUSR, proc_auxv_operations),
3185 ONE("status", S_IRUGO, proc_pid_status),
3186 ONE("personality", S_IRUSR, proc_pid_personality),
3187 ONE("limits", S_IRUGO, proc_pid_limits),
3188 #ifdef CONFIG_SCHED_DEBUG
3189 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3190 #endif
3191 #ifdef CONFIG_SCHED_AUTOGROUP
3192 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3193 #endif
3194 #ifdef CONFIG_TIME_NS
3195 REG("timens_offsets", S_IRUGO|S_IWUSR, proc_timens_offsets_operations),
3196 #endif
3197 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3198 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3199 ONE("syscall", S_IRUSR, proc_pid_syscall),
3200 #endif
3201 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3202 ONE("stat", S_IRUGO, proc_tgid_stat),
3203 ONE("statm", S_IRUGO, proc_pid_statm),
3204 REG("maps", S_IRUGO, proc_pid_maps_operations),
3205 #ifdef CONFIG_NUMA
3206 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3207 #endif
3208 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3209 LNK("cwd", proc_cwd_link),
3210 LNK("root", proc_root_link),
3211 LNK("exe", proc_exe_link),
3212 REG("mounts", S_IRUGO, proc_mounts_operations),
3213 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3214 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3215 #ifdef CONFIG_PROC_PAGE_MONITOR
3216 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3217 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3218 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3219 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3220 #endif
3221 #ifdef CONFIG_SECURITY
3222 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3223 #endif
3224 #ifdef CONFIG_KALLSYMS
3225 ONE("wchan", S_IRUGO, proc_pid_wchan),
3226 #endif
3227 #ifdef CONFIG_STACKTRACE
3228 ONE("stack", S_IRUSR, proc_pid_stack),
3229 #endif
3230 #ifdef CONFIG_SCHED_INFO
3231 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3232 #endif
3233 #ifdef CONFIG_LATENCYTOP
3234 REG("latency", S_IRUGO, proc_lstats_operations),
3235 #endif
3236 #ifdef CONFIG_PROC_PID_CPUSET
3237 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3238 #endif
3239 #ifdef CONFIG_CGROUPS
3240 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3241 #endif
3242 #ifdef CONFIG_PROC_CPU_RESCTRL
3243 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3244 #endif
3245 ONE("oom_score", S_IRUGO, proc_oom_score),
3246 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3247 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3248 #ifdef CONFIG_AUDIT
3249 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3250 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3251 #endif
3252 #ifdef CONFIG_FAULT_INJECTION
3253 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3254 REG("fail-nth", 0644, proc_fail_nth_operations),
3255 #endif
3256 #ifdef CONFIG_ELF_CORE
3257 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3258 #endif
3259 #ifdef CONFIG_TASK_IO_ACCOUNTING
3260 ONE("io", S_IRUSR, proc_tgid_io_accounting),
3261 #endif
3262 #ifdef CONFIG_USER_NS
3263 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3264 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3265 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3266 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3267 #endif
3268 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3269 REG("timers", S_IRUGO, proc_timers_operations),
3270 #endif
3271 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3272 #ifdef CONFIG_LIVEPATCH
3273 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3274 #endif
3275 #ifdef CONFIG_STACKLEAK_METRICS
3276 ONE("stack_depth", S_IRUGO, proc_stack_depth),
3277 #endif
3278 #ifdef CONFIG_PROC_PID_ARCH_STATUS
3279 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3280 #endif
3281 #ifdef CONFIG_SECCOMP_CACHE_DEBUG
3282 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3283 #endif
3284 };
3285
3286 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3287 {
3288 return proc_pident_readdir(file, ctx,
3289 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3290 }
3291
3292 static const struct file_operations proc_tgid_base_operations = {
3293 .read = generic_read_dir,
3294 .iterate_shared = proc_tgid_base_readdir,
3295 .llseek = generic_file_llseek,
3296 };
3297
3298 struct pid *tgid_pidfd_to_pid(const struct file *file)
3299 {
3300 if (file->f_op != &proc_tgid_base_operations)
3301 return ERR_PTR(-EBADF);
3302
3303 return proc_pid(file_inode(file));
3304 }
3305
3306 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3307 {
3308 return proc_pident_lookup(dir, dentry,
3309 tgid_base_stuff,
3310 tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
3311 }
3312
3313 static const struct inode_operations proc_tgid_base_inode_operations = {
3314 .lookup = proc_tgid_base_lookup,
3315 .getattr = pid_getattr,
3316 .setattr = proc_setattr,
3317 .permission = proc_pid_permission,
3318 };
3319
3320 /**
3321 * proc_flush_pid - Remove dcache entries for @pid from the /proc dcache.
3322 * @pid: pid that should be flushed.
3323 *
3324 * This function walks a list of inodes (that belong to any proc
3325 * filesystem) that are attached to the pid and flushes them from
3326 * the dentry cache.
3327 *
3328 * It is safe and reasonable to cache /proc entries for a task until
3329 * that task exits. After that they just clog up the dcache with
3330 * useless entries, possibly causing useful dcache entries to be
3331 * flushed instead. This routine is provided to flush those useless
3332 * dcache entries when a process is reaped.
3333 *
3334 * NOTE: This routine is just an optimization so it does not guarantee
3335 * that no dcache entries will exist after a process is reaped
3336 * it just makes it very unlikely that any will persist.
3337 */
3338
3339 void proc_flush_pid(struct pid *pid)
3340 {
3341 proc_invalidate_siblings_dcache(&pid->inodes, &pid->lock);
3342 }
3343
3344 static struct dentry *proc_pid_instantiate(struct dentry * dentry,
3345 struct task_struct *task, const void *ptr)
3346 {
3347 struct inode *inode;
3348
3349 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3350 if (!inode)
3351 return ERR_PTR(-ENOENT);
3352
3353 inode->i_op = &proc_tgid_base_inode_operations;
3354 inode->i_fop = &proc_tgid_base_operations;
3355 inode->i_flags|=S_IMMUTABLE;
3356
3357 set_nlink(inode, nlink_tgid);
3358 pid_update_inode(task, inode);
3359
3360 d_set_d_op(dentry, &pid_dentry_operations);
3361 return d_splice_alias(inode, dentry);
3362 }
3363
3364 struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
3365 {
3366 struct task_struct *task;
3367 unsigned tgid;
3368 struct proc_fs_info *fs_info;
3369 struct pid_namespace *ns;
3370 struct dentry *result = ERR_PTR(-ENOENT);
3371
3372 tgid = name_to_int(&dentry->d_name);
3373 if (tgid == ~0U)
3374 goto out;
3375
3376 fs_info = proc_sb_info(dentry->d_sb);
3377 ns = fs_info->pid_ns;
3378 rcu_read_lock();
3379 task = find_task_by_pid_ns(tgid, ns);
3380 if (task)
3381 get_task_struct(task);
3382 rcu_read_unlock();
3383 if (!task)
3384 goto out;
3385
3386 /* Limit procfs to only ptraceable tasks */
3387 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE) {
3388 if (!has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS))
3389 goto out_put_task;
3390 }
3391
3392 result = proc_pid_instantiate(dentry, task, NULL);
3393 out_put_task:
3394 put_task_struct(task);
3395 out:
3396 return result;
3397 }
3398
3399 /*
3400 * Find the first task with tgid >= tgid
3401 *
3402 */
3403 struct tgid_iter {
3404 unsigned int tgid;
3405 struct task_struct *task;
3406 };
3407 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3408 {
3409 struct pid *pid;
3410
3411 if (iter.task)
3412 put_task_struct(iter.task);
3413 rcu_read_lock();
3414 retry:
3415 iter.task = NULL;
3416 pid = find_ge_pid(iter.tgid, ns);
3417 if (pid) {
3418 iter.tgid = pid_nr_ns(pid, ns);
3419 iter.task = pid_task(pid, PIDTYPE_TGID);
3420 if (!iter.task) {
3421 iter.tgid += 1;
3422 goto retry;
3423 }
3424 get_task_struct(iter.task);
3425 }
3426 rcu_read_unlock();
3427 return iter;
3428 }
3429
3430 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3431
3432 /* for the /proc/ directory itself, after non-process stuff has been done */
3433 int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3434 {
3435 struct tgid_iter iter;
3436 struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb);
3437 struct pid_namespace *ns = proc_pid_ns(file_inode(file)->i_sb);
3438 loff_t pos = ctx->pos;
3439
3440 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3441 return 0;
3442
3443 if (pos == TGID_OFFSET - 2) {
3444 struct inode *inode = d_inode(fs_info->proc_self);
3445 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3446 return 0;
3447 ctx->pos = pos = pos + 1;
3448 }
3449 if (pos == TGID_OFFSET - 1) {
3450 struct inode *inode = d_inode(fs_info->proc_thread_self);
3451 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3452 return 0;
3453 ctx->pos = pos = pos + 1;
3454 }
3455 iter.tgid = pos - TGID_OFFSET;
3456 iter.task = NULL;
3457 for (iter = next_tgid(ns, iter);
3458 iter.task;
3459 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3460 char name[10 + 1];
3461 unsigned int len;
3462
3463 cond_resched();
3464 if (!has_pid_permissions(fs_info, iter.task, HIDEPID_INVISIBLE))
3465 continue;
3466
3467 len = snprintf(name, sizeof(name), "%u", iter.tgid);
3468 ctx->pos = iter.tgid + TGID_OFFSET;
3469 if (!proc_fill_cache(file, ctx, name, len,
3470 proc_pid_instantiate, iter.task, NULL)) {
3471 put_task_struct(iter.task);
3472 return 0;
3473 }
3474 }
3475 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3476 return 0;
3477 }
3478
3479 /*
3480 * proc_tid_comm_permission is a special permission function exclusively
3481 * used for the node /proc/<pid>/task/<tid>/comm.
3482 * It bypasses generic permission checks in the case where a task of the same
3483 * task group attempts to access the node.
3484 * The rationale behind this is that glibc and bionic access this node for
3485 * cross thread naming (pthread_set/getname_np(!self)). However, if
3486 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3487 * which locks out the cross thread naming implementation.
3488 * This function makes sure that the node is always accessible for members of
3489 * same thread group.
3490 */
3491 static int proc_tid_comm_permission(struct user_namespace *mnt_userns,
3492 struct inode *inode, int mask)
3493 {
3494 bool is_same_tgroup;
3495 struct task_struct *task;
3496
3497 task = get_proc_task(inode);
3498 if (!task)
3499 return -ESRCH;
3500 is_same_tgroup = same_thread_group(current, task);
3501 put_task_struct(task);
3502
3503 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3504 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3505 * read or written by the members of the corresponding
3506 * thread group.
3507 */
3508 return 0;
3509 }
3510
3511 return generic_permission(&init_user_ns, inode, mask);
3512 }
3513
3514 static const struct inode_operations proc_tid_comm_inode_operations = {
3515 .permission = proc_tid_comm_permission,
3516 };
3517
3518 /*
3519 * Tasks
3520 */
3521 static const struct pid_entry tid_base_stuff[] = {
3522 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3523 DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3524 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3525 #ifdef CONFIG_NET
3526 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3527 #endif
3528 REG("environ", S_IRUSR, proc_environ_operations),
3529 REG("auxv", S_IRUSR, proc_auxv_operations),
3530 ONE("status", S_IRUGO, proc_pid_status),
3531 ONE("personality", S_IRUSR, proc_pid_personality),
3532 ONE("limits", S_IRUGO, proc_pid_limits),
3533 #ifdef CONFIG_SCHED_DEBUG
3534 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3535 #endif
3536 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3537 &proc_tid_comm_inode_operations,
3538 &proc_pid_set_comm_operations, {}),
3539 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3540 ONE("syscall", S_IRUSR, proc_pid_syscall),
3541 #endif
3542 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3543 ONE("stat", S_IRUGO, proc_tid_stat),
3544 ONE("statm", S_IRUGO, proc_pid_statm),
3545 REG("maps", S_IRUGO, proc_pid_maps_operations),
3546 #ifdef CONFIG_PROC_CHILDREN
3547 REG("children", S_IRUGO, proc_tid_children_operations),
3548 #endif
3549 #ifdef CONFIG_NUMA
3550 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3551 #endif
3552 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3553 LNK("cwd", proc_cwd_link),
3554 LNK("root", proc_root_link),
3555 LNK("exe", proc_exe_link),
3556 REG("mounts", S_IRUGO, proc_mounts_operations),
3557 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3558 #ifdef CONFIG_PROC_PAGE_MONITOR
3559 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3560 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3561 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3562 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3563 #endif
3564 #ifdef CONFIG_SECURITY
3565 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3566 #endif
3567 #ifdef CONFIG_KALLSYMS
3568 ONE("wchan", S_IRUGO, proc_pid_wchan),
3569 #endif
3570 #ifdef CONFIG_STACKTRACE
3571 ONE("stack", S_IRUSR, proc_pid_stack),
3572 #endif
3573 #ifdef CONFIG_SCHED_INFO
3574 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3575 #endif
3576 #ifdef CONFIG_LATENCYTOP
3577 REG("latency", S_IRUGO, proc_lstats_operations),
3578 #endif
3579 #ifdef CONFIG_PROC_PID_CPUSET
3580 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3581 #endif
3582 #ifdef CONFIG_CGROUPS
3583 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3584 #endif
3585 #ifdef CONFIG_PROC_CPU_RESCTRL
3586 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3587 #endif
3588 ONE("oom_score", S_IRUGO, proc_oom_score),
3589 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3590 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3591 #ifdef CONFIG_AUDIT
3592 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3593 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3594 #endif
3595 #ifdef CONFIG_FAULT_INJECTION
3596 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3597 REG("fail-nth", 0644, proc_fail_nth_operations),
3598 #endif
3599 #ifdef CONFIG_TASK_IO_ACCOUNTING
3600 ONE("io", S_IRUSR, proc_tid_io_accounting),
3601 #endif
3602 #ifdef CONFIG_USER_NS
3603 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3604 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3605 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3606 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3607 #endif
3608 #ifdef CONFIG_LIVEPATCH
3609 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3610 #endif
3611 #ifdef CONFIG_PROC_PID_ARCH_STATUS
3612 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3613 #endif
3614 #ifdef CONFIG_SECCOMP_CACHE_DEBUG
3615 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3616 #endif
3617 };
3618
3619 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3620 {
3621 return proc_pident_readdir(file, ctx,
3622 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3623 }
3624
3625 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3626 {
3627 return proc_pident_lookup(dir, dentry,
3628 tid_base_stuff,
3629 tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
3630 }
3631
3632 static const struct file_operations proc_tid_base_operations = {
3633 .read = generic_read_dir,
3634 .iterate_shared = proc_tid_base_readdir,
3635 .llseek = generic_file_llseek,
3636 };
3637
3638 static const struct inode_operations proc_tid_base_inode_operations = {
3639 .lookup = proc_tid_base_lookup,
3640 .getattr = pid_getattr,
3641 .setattr = proc_setattr,
3642 };
3643
3644 static struct dentry *proc_task_instantiate(struct dentry *dentry,
3645 struct task_struct *task, const void *ptr)
3646 {
3647 struct inode *inode;
3648 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3649 if (!inode)
3650 return ERR_PTR(-ENOENT);
3651
3652 inode->i_op = &proc_tid_base_inode_operations;
3653 inode->i_fop = &proc_tid_base_operations;
3654 inode->i_flags |= S_IMMUTABLE;
3655
3656 set_nlink(inode, nlink_tid);
3657 pid_update_inode(task, inode);
3658
3659 d_set_d_op(dentry, &pid_dentry_operations);
3660 return d_splice_alias(inode, dentry);
3661 }
3662
3663 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3664 {
3665 struct task_struct *task;
3666 struct task_struct *leader = get_proc_task(dir);
3667 unsigned tid;
3668 struct proc_fs_info *fs_info;
3669 struct pid_namespace *ns;
3670 struct dentry *result = ERR_PTR(-ENOENT);
3671
3672 if (!leader)
3673 goto out_no_task;
3674
3675 tid = name_to_int(&dentry->d_name);
3676 if (tid == ~0U)
3677 goto out;
3678
3679 fs_info = proc_sb_info(dentry->d_sb);
3680 ns = fs_info->pid_ns;
3681 rcu_read_lock();
3682 task = find_task_by_pid_ns(tid, ns);
3683 if (task)
3684 get_task_struct(task);
3685 rcu_read_unlock();
3686 if (!task)
3687 goto out;
3688 if (!same_thread_group(leader, task))
3689 goto out_drop_task;
3690
3691 result = proc_task_instantiate(dentry, task, NULL);
3692 out_drop_task:
3693 put_task_struct(task);
3694 out:
3695 put_task_struct(leader);
3696 out_no_task:
3697 return result;
3698 }
3699
3700 /*
3701 * Find the first tid of a thread group to return to user space.
3702 *
3703 * Usually this is just the thread group leader, but if the users
3704 * buffer was too small or there was a seek into the middle of the
3705 * directory we have more work todo.
3706 *
3707 * In the case of a short read we start with find_task_by_pid.
3708 *
3709 * In the case of a seek we start with the leader and walk nr
3710 * threads past it.
3711 */
3712 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3713 struct pid_namespace *ns)
3714 {
3715 struct task_struct *pos, *task;
3716 unsigned long nr = f_pos;
3717
3718 if (nr != f_pos) /* 32bit overflow? */
3719 return NULL;
3720
3721 rcu_read_lock();
3722 task = pid_task(pid, PIDTYPE_PID);
3723 if (!task)
3724 goto fail;
3725
3726 /* Attempt to start with the tid of a thread */
3727 if (tid && nr) {
3728 pos = find_task_by_pid_ns(tid, ns);
3729 if (pos && same_thread_group(pos, task))
3730 goto found;
3731 }
3732
3733 /* If nr exceeds the number of threads there is nothing todo */
3734 if (nr >= get_nr_threads(task))
3735 goto fail;
3736
3737 /* If we haven't found our starting place yet start
3738 * with the leader and walk nr threads forward.
3739 */
3740 pos = task = task->group_leader;
3741 do {
3742 if (!nr--)
3743 goto found;
3744 } while_each_thread(task, pos);
3745 fail:
3746 pos = NULL;
3747 goto out;
3748 found:
3749 get_task_struct(pos);
3750 out:
3751 rcu_read_unlock();
3752 return pos;
3753 }
3754
3755 /*
3756 * Find the next thread in the thread list.
3757 * Return NULL if there is an error or no next thread.
3758 *
3759 * The reference to the input task_struct is released.
3760 */
3761 static struct task_struct *next_tid(struct task_struct *start)
3762 {
3763 struct task_struct *pos = NULL;
3764 rcu_read_lock();
3765 if (pid_alive(start)) {
3766 pos = next_thread(start);
3767 if (thread_group_leader(pos))
3768 pos = NULL;
3769 else
3770 get_task_struct(pos);
3771 }
3772 rcu_read_unlock();
3773 put_task_struct(start);
3774 return pos;
3775 }
3776
3777 /* for the /proc/TGID/task/ directories */
3778 static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3779 {
3780 struct inode *inode = file_inode(file);
3781 struct task_struct *task;
3782 struct pid_namespace *ns;
3783 int tid;
3784
3785 if (proc_inode_is_dead(inode))
3786 return -ENOENT;
3787
3788 if (!dir_emit_dots(file, ctx))
3789 return 0;
3790
3791 /* f_version caches the tgid value that the last readdir call couldn't
3792 * return. lseek aka telldir automagically resets f_version to 0.
3793 */
3794 ns = proc_pid_ns(inode->i_sb);
3795 tid = (int)file->f_version;
3796 file->f_version = 0;
3797 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3798 task;
3799 task = next_tid(task), ctx->pos++) {
3800 char name[10 + 1];
3801 unsigned int len;
3802 tid = task_pid_nr_ns(task, ns);
3803 len = snprintf(name, sizeof(name), "%u", tid);
3804 if (!proc_fill_cache(file, ctx, name, len,
3805 proc_task_instantiate, task, NULL)) {
3806 /* returning this tgid failed, save it as the first
3807 * pid for the next readir call */
3808 file->f_version = (u64)tid;
3809 put_task_struct(task);
3810 break;
3811 }
3812 }
3813
3814 return 0;
3815 }
3816
3817 static int proc_task_getattr(struct user_namespace *mnt_userns,
3818 const struct path *path, struct kstat *stat,
3819 u32 request_mask, unsigned int query_flags)
3820 {
3821 struct inode *inode = d_inode(path->dentry);
3822 struct task_struct *p = get_proc_task(inode);
3823 generic_fillattr(&init_user_ns, inode, stat);
3824
3825 if (p) {
3826 stat->nlink += get_nr_threads(p);
3827 put_task_struct(p);
3828 }
3829
3830 return 0;
3831 }
3832
3833 static const struct inode_operations proc_task_inode_operations = {
3834 .lookup = proc_task_lookup,
3835 .getattr = proc_task_getattr,
3836 .setattr = proc_setattr,
3837 .permission = proc_pid_permission,
3838 };
3839
3840 static const struct file_operations proc_task_operations = {
3841 .read = generic_read_dir,
3842 .iterate_shared = proc_task_readdir,
3843 .llseek = generic_file_llseek,
3844 };
3845
3846 void __init set_proc_pid_nlink(void)
3847 {
3848 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3849 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3850 }
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