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drm/panfrost: Remove set but not used variable 'bo'
[linux/fpc-iii.git] / fs / proc / base.c
blobc7c64272b0fa6c57822a234616565896e7afd1ae
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/proc/base.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 * proc base directory handling functions
8 *
9 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
10 * Instead of using magical inumbers to determine the kind of object
11 * we allocate and fill in-core inodes upon lookup. They don't even
12 * go into icache. We cache the reference to task_struct upon lookup too.
13 * Eventually it should become a filesystem in its own. We don't use the
14 * rest of procfs anymore.
15 *
16 *
17 * Changelog:
18 * 17-Jan-2005
19 * Allan Bezerra
20 * Bruna Moreira <bruna.moreira@indt.org.br>
21 * Edjard Mota <edjard.mota@indt.org.br>
22 * Ilias Biris <ilias.biris@indt.org.br>
23 * Mauricio Lin <mauricio.lin@indt.org.br>
24 *
25 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
26 *
27 * A new process specific entry (smaps) included in /proc. It shows the
28 * size of rss for each memory area. The maps entry lacks information
29 * about physical memory size (rss) for each mapped file, i.e.,
30 * rss information for executables and library files.
31 * This additional information is useful for any tools that need to know
32 * about physical memory consumption for a process specific library.
33 *
34 * Changelog:
35 * 21-Feb-2005
36 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
37 * Pud inclusion in the page table walking.
38 *
39 * ChangeLog:
40 * 10-Mar-2005
41 * 10LE Instituto Nokia de Tecnologia - INdT:
42 * A better way to walks through the page table as suggested by Hugh Dickins.
43 *
44 * Simo Piiroinen <simo.piiroinen@nokia.com>:
45 * Smaps information related to shared, private, clean and dirty pages.
46 *
47 * Paul Mundt <paul.mundt@nokia.com>:
48 * Overall revision about smaps.
49 */
50
51 #include <linux/uaccess.h>
52
53 #include <linux/errno.h>
54 #include <linux/time.h>
55 #include <linux/proc_fs.h>
56 #include <linux/stat.h>
57 #include <linux/task_io_accounting_ops.h>
58 #include <linux/init.h>
59 #include <linux/capability.h>
60 #include <linux/file.h>
61 #include <linux/fdtable.h>
62 #include <linux/generic-radix-tree.h>
63 #include <linux/string.h>
64 #include <linux/seq_file.h>
65 #include <linux/namei.h>
66 #include <linux/mnt_namespace.h>
67 #include <linux/mm.h>
68 #include <linux/swap.h>
69 #include <linux/rcupdate.h>
70 #include <linux/kallsyms.h>
71 #include <linux/stacktrace.h>
72 #include <linux/resource.h>
73 #include <linux/module.h>
74 #include <linux/mount.h>
75 #include <linux/security.h>
76 #include <linux/ptrace.h>
77 #include <linux/tracehook.h>
78 #include <linux/printk.h>
79 #include <linux/cache.h>
80 #include <linux/cgroup.h>
81 #include <linux/cpuset.h>
82 #include <linux/audit.h>
83 #include <linux/poll.h>
84 #include <linux/nsproxy.h>
85 #include <linux/oom.h>
86 #include <linux/elf.h>
87 #include <linux/pid_namespace.h>
88 #include <linux/user_namespace.h>
89 #include <linux/fs_struct.h>
90 #include <linux/slab.h>
91 #include <linux/sched/autogroup.h>
92 #include <linux/sched/mm.h>
93 #include <linux/sched/coredump.h>
94 #include <linux/sched/debug.h>
95 #include <linux/sched/stat.h>
96 #include <linux/posix-timers.h>
97 #include <linux/time_namespace.h>
98 #include <linux/resctrl.h>
99 #include <trace/events/oom.h>
100 #include "internal.h"
101 #include "fd.h"
102
103 #include "../../lib/kstrtox.h"
104
105 /* NOTE:
106 * Implementing inode permission operations in /proc is almost
107 * certainly an error. Permission checks need to happen during
108 * each system call not at open time. The reason is that most of
109 * what we wish to check for permissions in /proc varies at runtime.
110 *
111 * The classic example of a problem is opening file descriptors
112 * in /proc for a task before it execs a suid executable.
113 */
114
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 char symname[KSYM_NAME_LEN];
390
391 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
392 goto print0;
393
394 wchan = get_wchan(task);
395 if (wchan && !lookup_symbol_name(wchan, symname)) {
396 seq_puts(m, symname);
397 return 0;
398 }
399
400 print0:
401 seq_putc(m, '0');
402 return 0;
403 }
404 #endif /* CONFIG_KALLSYMS */
405
406 static int lock_trace(struct task_struct *task)
407 {
408 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
409 if (err)
410 return err;
411 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
412 mutex_unlock(&task->signal->cred_guard_mutex);
413 return -EPERM;
414 }
415 return 0;
416 }
417
418 static void unlock_trace(struct task_struct *task)
419 {
420 mutex_unlock(&task->signal->cred_guard_mutex);
421 }
422
423 #ifdef CONFIG_STACKTRACE
424
425 #define MAX_STACK_TRACE_DEPTH 64
426
427 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
428 struct pid *pid, struct task_struct *task)
429 {
430 unsigned long *entries;
431 int err;
432
433 /*
434 * The ability to racily run the kernel stack unwinder on a running task
435 * and then observe the unwinder output is scary; while it is useful for
436 * debugging kernel issues, it can also allow an attacker to leak kernel
437 * stack contents.
438 * Doing this in a manner that is at least safe from races would require
439 * some work to ensure that the remote task can not be scheduled; and
440 * even then, this would still expose the unwinder as local attack
441 * surface.
442 * Therefore, this interface is restricted to root.
443 */
444 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
445 return -EACCES;
446
447 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
448 GFP_KERNEL);
449 if (!entries)
450 return -ENOMEM;
451
452 err = lock_trace(task);
453 if (!err) {
454 unsigned int i, nr_entries;
455
456 nr_entries = stack_trace_save_tsk(task, entries,
457 MAX_STACK_TRACE_DEPTH, 0);
458
459 for (i = 0; i < nr_entries; i++) {
460 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
461 }
462
463 unlock_trace(task);
464 }
465 kfree(entries);
466
467 return err;
468 }
469 #endif
470
471 #ifdef CONFIG_SCHED_INFO
472 /*
473 * Provides /proc/PID/schedstat
474 */
475 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
476 struct pid *pid, struct task_struct *task)
477 {
478 if (unlikely(!sched_info_on()))
479 seq_puts(m, "0 0 0\n");
480 else
481 seq_printf(m, "%llu %llu %lu\n",
482 (unsigned long long)task->se.sum_exec_runtime,
483 (unsigned long long)task->sched_info.run_delay,
484 task->sched_info.pcount);
485
486 return 0;
487 }
488 #endif
489
490 #ifdef CONFIG_LATENCYTOP
491 static int lstats_show_proc(struct seq_file *m, void *v)
492 {
493 int i;
494 struct inode *inode = m->private;
495 struct task_struct *task = get_proc_task(inode);
496
497 if (!task)
498 return -ESRCH;
499 seq_puts(m, "Latency Top version : v0.1\n");
500 for (i = 0; i < LT_SAVECOUNT; i++) {
501 struct latency_record *lr = &task->latency_record[i];
502 if (lr->backtrace[0]) {
503 int q;
504 seq_printf(m, "%i %li %li",
505 lr->count, lr->time, lr->max);
506 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
507 unsigned long bt = lr->backtrace[q];
508
509 if (!bt)
510 break;
511 seq_printf(m, " %ps", (void *)bt);
512 }
513 seq_putc(m, '\n');
514 }
515
516 }
517 put_task_struct(task);
518 return 0;
519 }
520
521 static int lstats_open(struct inode *inode, struct file *file)
522 {
523 return single_open(file, lstats_show_proc, inode);
524 }
525
526 static ssize_t lstats_write(struct file *file, const char __user *buf,
527 size_t count, loff_t *offs)
528 {
529 struct task_struct *task = get_proc_task(file_inode(file));
530
531 if (!task)
532 return -ESRCH;
533 clear_tsk_latency_tracing(task);
534 put_task_struct(task);
535
536 return count;
537 }
538
539 static const struct file_operations proc_lstats_operations = {
540 .open = lstats_open,
541 .read = seq_read,
542 .write = lstats_write,
543 .llseek = seq_lseek,
544 .release = single_release,
545 };
546
547 #endif
548
549 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
550 struct pid *pid, struct task_struct *task)
551 {
552 unsigned long totalpages = totalram_pages() + total_swap_pages;
553 unsigned long points = 0;
554
555 points = oom_badness(task, totalpages) * 1000 / totalpages;
556 seq_printf(m, "%lu\n", points);
557
558 return 0;
559 }
560
561 struct limit_names {
562 const char *name;
563 const char *unit;
564 };
565
566 static const struct limit_names lnames[RLIM_NLIMITS] = {
567 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
568 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
569 [RLIMIT_DATA] = {"Max data size", "bytes"},
570 [RLIMIT_STACK] = {"Max stack size", "bytes"},
571 [RLIMIT_CORE] = {"Max core file size", "bytes"},
572 [RLIMIT_RSS] = {"Max resident set", "bytes"},
573 [RLIMIT_NPROC] = {"Max processes", "processes"},
574 [RLIMIT_NOFILE] = {"Max open files", "files"},
575 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
576 [RLIMIT_AS] = {"Max address space", "bytes"},
577 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
578 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
579 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
580 [RLIMIT_NICE] = {"Max nice priority", NULL},
581 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
582 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
583 };
584
585 /* Display limits for a process */
586 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
587 struct pid *pid, struct task_struct *task)
588 {
589 unsigned int i;
590 unsigned long flags;
591
592 struct rlimit rlim[RLIM_NLIMITS];
593
594 if (!lock_task_sighand(task, &flags))
595 return 0;
596 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
597 unlock_task_sighand(task, &flags);
598
599 /*
600 * print the file header
601 */
602 seq_puts(m, "Limit "
603 "Soft Limit "
604 "Hard Limit "
605 "Units \n");
606
607 for (i = 0; i < RLIM_NLIMITS; i++) {
608 if (rlim[i].rlim_cur == RLIM_INFINITY)
609 seq_printf(m, "%-25s %-20s ",
610 lnames[i].name, "unlimited");
611 else
612 seq_printf(m, "%-25s %-20lu ",
613 lnames[i].name, rlim[i].rlim_cur);
614
615 if (rlim[i].rlim_max == RLIM_INFINITY)
616 seq_printf(m, "%-20s ", "unlimited");
617 else
618 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
619
620 if (lnames[i].unit)
621 seq_printf(m, "%-10s\n", lnames[i].unit);
622 else
623 seq_putc(m, '\n');
624 }
625
626 return 0;
627 }
628
629 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
630 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
631 struct pid *pid, struct task_struct *task)
632 {
633 struct syscall_info info;
634 u64 *args = &info.data.args[0];
635 int res;
636
637 res = lock_trace(task);
638 if (res)
639 return res;
640
641 if (task_current_syscall(task, &info))
642 seq_puts(m, "running\n");
643 else if (info.data.nr < 0)
644 seq_printf(m, "%d 0x%llx 0x%llx\n",
645 info.data.nr, info.sp, info.data.instruction_pointer);
646 else
647 seq_printf(m,
648 "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
649 info.data.nr,
650 args[0], args[1], args[2], args[3], args[4], args[5],
651 info.sp, info.data.instruction_pointer);
652 unlock_trace(task);
653
654 return 0;
655 }
656 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
657
658 /************************************************************************/
659 /* Here the fs part begins */
660 /************************************************************************/
661
662 /* permission checks */
663 static int proc_fd_access_allowed(struct inode *inode)
664 {
665 struct task_struct *task;
666 int allowed = 0;
667 /* Allow access to a task's file descriptors if it is us or we
668 * may use ptrace attach to the process and find out that
669 * information.
670 */
671 task = get_proc_task(inode);
672 if (task) {
673 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
674 put_task_struct(task);
675 }
676 return allowed;
677 }
678
679 int proc_setattr(struct dentry *dentry, struct iattr *attr)
680 {
681 int error;
682 struct inode *inode = d_inode(dentry);
683
684 if (attr->ia_valid & ATTR_MODE)
685 return -EPERM;
686
687 error = setattr_prepare(dentry, attr);
688 if (error)
689 return error;
690
691 setattr_copy(inode, attr);
692 mark_inode_dirty(inode);
693 return 0;
694 }
695
696 /*
697 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
698 * or euid/egid (for hide_pid_min=2)?
699 */
700 static bool has_pid_permissions(struct pid_namespace *pid,
701 struct task_struct *task,
702 int hide_pid_min)
703 {
704 if (pid->hide_pid < hide_pid_min)
705 return true;
706 if (in_group_p(pid->pid_gid))
707 return true;
708 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
709 }
710
711
712 static int proc_pid_permission(struct inode *inode, int mask)
713 {
714 struct pid_namespace *pid = proc_pid_ns(inode);
715 struct task_struct *task;
716 bool has_perms;
717
718 task = get_proc_task(inode);
719 if (!task)
720 return -ESRCH;
721 has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS);
722 put_task_struct(task);
723
724 if (!has_perms) {
725 if (pid->hide_pid == HIDEPID_INVISIBLE) {
726 /*
727 * Let's make getdents(), stat(), and open()
728 * consistent with each other. If a process
729 * may not stat() a file, it shouldn't be seen
730 * in procfs at all.
731 */
732 return -ENOENT;
733 }
734
735 return -EPERM;
736 }
737 return generic_permission(inode, mask);
738 }
739
740
741
742 static const struct inode_operations proc_def_inode_operations = {
743 .setattr = proc_setattr,
744 };
745
746 static int proc_single_show(struct seq_file *m, void *v)
747 {
748 struct inode *inode = m->private;
749 struct pid_namespace *ns = proc_pid_ns(inode);
750 struct pid *pid = proc_pid(inode);
751 struct task_struct *task;
752 int ret;
753
754 task = get_pid_task(pid, PIDTYPE_PID);
755 if (!task)
756 return -ESRCH;
757
758 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
759
760 put_task_struct(task);
761 return ret;
762 }
763
764 static int proc_single_open(struct inode *inode, struct file *filp)
765 {
766 return single_open(filp, proc_single_show, inode);
767 }
768
769 static const struct file_operations proc_single_file_operations = {
770 .open = proc_single_open,
771 .read = seq_read,
772 .llseek = seq_lseek,
773 .release = single_release,
774 };
775
776
777 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
778 {
779 struct task_struct *task = get_proc_task(inode);
780 struct mm_struct *mm = ERR_PTR(-ESRCH);
781
782 if (task) {
783 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
784 put_task_struct(task);
785
786 if (!IS_ERR_OR_NULL(mm)) {
787 /* ensure this mm_struct can't be freed */
788 mmgrab(mm);
789 /* but do not pin its memory */
790 mmput(mm);
791 }
792 }
793
794 return mm;
795 }
796
797 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
798 {
799 struct mm_struct *mm = proc_mem_open(inode, mode);
800
801 if (IS_ERR(mm))
802 return PTR_ERR(mm);
803
804 file->private_data = mm;
805 return 0;
806 }
807
808 static int mem_open(struct inode *inode, struct file *file)
809 {
810 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
811
812 /* OK to pass negative loff_t, we can catch out-of-range */
813 file->f_mode |= FMODE_UNSIGNED_OFFSET;
814
815 return ret;
816 }
817
818 static ssize_t mem_rw(struct file *file, char __user *buf,
819 size_t count, loff_t *ppos, int write)
820 {
821 struct mm_struct *mm = file->private_data;
822 unsigned long addr = *ppos;
823 ssize_t copied;
824 char *page;
825 unsigned int flags;
826
827 if (!mm)
828 return 0;
829
830 page = (char *)__get_free_page(GFP_KERNEL);
831 if (!page)
832 return -ENOMEM;
833
834 copied = 0;
835 if (!mmget_not_zero(mm))
836 goto free;
837
838 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
839
840 while (count > 0) {
841 int this_len = min_t(int, count, PAGE_SIZE);
842
843 if (write && copy_from_user(page, buf, this_len)) {
844 copied = -EFAULT;
845 break;
846 }
847
848 this_len = access_remote_vm(mm, addr, page, this_len, flags);
849 if (!this_len) {
850 if (!copied)
851 copied = -EIO;
852 break;
853 }
854
855 if (!write && copy_to_user(buf, page, this_len)) {
856 copied = -EFAULT;
857 break;
858 }
859
860 buf += this_len;
861 addr += this_len;
862 copied += this_len;
863 count -= this_len;
864 }
865 *ppos = addr;
866
867 mmput(mm);
868 free:
869 free_page((unsigned long) page);
870 return copied;
871 }
872
873 static ssize_t mem_read(struct file *file, char __user *buf,
874 size_t count, loff_t *ppos)
875 {
876 return mem_rw(file, buf, count, ppos, 0);
877 }
878
879 static ssize_t mem_write(struct file *file, const char __user *buf,
880 size_t count, loff_t *ppos)
881 {
882 return mem_rw(file, (char __user*)buf, count, ppos, 1);
883 }
884
885 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
886 {
887 switch (orig) {
888 case 0:
889 file->f_pos = offset;
890 break;
891 case 1:
892 file->f_pos += offset;
893 break;
894 default:
895 return -EINVAL;
896 }
897 force_successful_syscall_return();
898 return file->f_pos;
899 }
900
901 static int mem_release(struct inode *inode, struct file *file)
902 {
903 struct mm_struct *mm = file->private_data;
904 if (mm)
905 mmdrop(mm);
906 return 0;
907 }
908
909 static const struct file_operations proc_mem_operations = {
910 .llseek = mem_lseek,
911 .read = mem_read,
912 .write = mem_write,
913 .open = mem_open,
914 .release = mem_release,
915 };
916
917 static int environ_open(struct inode *inode, struct file *file)
918 {
919 return __mem_open(inode, file, PTRACE_MODE_READ);
920 }
921
922 static ssize_t environ_read(struct file *file, char __user *buf,
923 size_t count, loff_t *ppos)
924 {
925 char *page;
926 unsigned long src = *ppos;
927 int ret = 0;
928 struct mm_struct *mm = file->private_data;
929 unsigned long env_start, env_end;
930
931 /* Ensure the process spawned far enough to have an environment. */
932 if (!mm || !mm->env_end)
933 return 0;
934
935 page = (char *)__get_free_page(GFP_KERNEL);
936 if (!page)
937 return -ENOMEM;
938
939 ret = 0;
940 if (!mmget_not_zero(mm))
941 goto free;
942
943 spin_lock(&mm->arg_lock);
944 env_start = mm->env_start;
945 env_end = mm->env_end;
946 spin_unlock(&mm->arg_lock);
947
948 while (count > 0) {
949 size_t this_len, max_len;
950 int retval;
951
952 if (src >= (env_end - env_start))
953 break;
954
955 this_len = env_end - (env_start + src);
956
957 max_len = min_t(size_t, PAGE_SIZE, count);
958 this_len = min(max_len, this_len);
959
960 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
961
962 if (retval <= 0) {
963 ret = retval;
964 break;
965 }
966
967 if (copy_to_user(buf, page, retval)) {
968 ret = -EFAULT;
969 break;
970 }
971
972 ret += retval;
973 src += retval;
974 buf += retval;
975 count -= retval;
976 }
977 *ppos = src;
978 mmput(mm);
979
980 free:
981 free_page((unsigned long) page);
982 return ret;
983 }
984
985 static const struct file_operations proc_environ_operations = {
986 .open = environ_open,
987 .read = environ_read,
988 .llseek = generic_file_llseek,
989 .release = mem_release,
990 };
991
992 static int auxv_open(struct inode *inode, struct file *file)
993 {
994 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
995 }
996
997 static ssize_t auxv_read(struct file *file, char __user *buf,
998 size_t count, loff_t *ppos)
999 {
1000 struct mm_struct *mm = file->private_data;
1001 unsigned int nwords = 0;
1002
1003 if (!mm)
1004 return 0;
1005 do {
1006 nwords += 2;
1007 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1008 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1009 nwords * sizeof(mm->saved_auxv[0]));
1010 }
1011
1012 static const struct file_operations proc_auxv_operations = {
1013 .open = auxv_open,
1014 .read = auxv_read,
1015 .llseek = generic_file_llseek,
1016 .release = mem_release,
1017 };
1018
1019 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1020 loff_t *ppos)
1021 {
1022 struct task_struct *task = get_proc_task(file_inode(file));
1023 char buffer[PROC_NUMBUF];
1024 int oom_adj = OOM_ADJUST_MIN;
1025 size_t len;
1026
1027 if (!task)
1028 return -ESRCH;
1029 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1030 oom_adj = OOM_ADJUST_MAX;
1031 else
1032 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1033 OOM_SCORE_ADJ_MAX;
1034 put_task_struct(task);
1035 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1036 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1037 }
1038
1039 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1040 {
1041 static DEFINE_MUTEX(oom_adj_mutex);
1042 struct mm_struct *mm = NULL;
1043 struct task_struct *task;
1044 int err = 0;
1045
1046 task = get_proc_task(file_inode(file));
1047 if (!task)
1048 return -ESRCH;
1049
1050 mutex_lock(&oom_adj_mutex);
1051 if (legacy) {
1052 if (oom_adj < task->signal->oom_score_adj &&
1053 !capable(CAP_SYS_RESOURCE)) {
1054 err = -EACCES;
1055 goto err_unlock;
1056 }
1057 /*
1058 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1059 * /proc/pid/oom_score_adj instead.
1060 */
1061 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1062 current->comm, task_pid_nr(current), task_pid_nr(task),
1063 task_pid_nr(task));
1064 } else {
1065 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1066 !capable(CAP_SYS_RESOURCE)) {
1067 err = -EACCES;
1068 goto err_unlock;
1069 }
1070 }
1071
1072 /*
1073 * Make sure we will check other processes sharing the mm if this is
1074 * not vfrok which wants its own oom_score_adj.
1075 * pin the mm so it doesn't go away and get reused after task_unlock
1076 */
1077 if (!task->vfork_done) {
1078 struct task_struct *p = find_lock_task_mm(task);
1079
1080 if (p) {
1081 if (atomic_read(&p->mm->mm_users) > 1) {
1082 mm = p->mm;
1083 mmgrab(mm);
1084 }
1085 task_unlock(p);
1086 }
1087 }
1088
1089 task->signal->oom_score_adj = oom_adj;
1090 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1091 task->signal->oom_score_adj_min = (short)oom_adj;
1092 trace_oom_score_adj_update(task);
1093
1094 if (mm) {
1095 struct task_struct *p;
1096
1097 rcu_read_lock();
1098 for_each_process(p) {
1099 if (same_thread_group(task, p))
1100 continue;
1101
1102 /* do not touch kernel threads or the global init */
1103 if (p->flags & PF_KTHREAD || is_global_init(p))
1104 continue;
1105
1106 task_lock(p);
1107 if (!p->vfork_done && process_shares_mm(p, mm)) {
1108 p->signal->oom_score_adj = oom_adj;
1109 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1110 p->signal->oom_score_adj_min = (short)oom_adj;
1111 }
1112 task_unlock(p);
1113 }
1114 rcu_read_unlock();
1115 mmdrop(mm);
1116 }
1117 err_unlock:
1118 mutex_unlock(&oom_adj_mutex);
1119 put_task_struct(task);
1120 return err;
1121 }
1122
1123 /*
1124 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1125 * kernels. The effective policy is defined by oom_score_adj, which has a
1126 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1127 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1128 * Processes that become oom disabled via oom_adj will still be oom disabled
1129 * with this implementation.
1130 *
1131 * oom_adj cannot be removed since existing userspace binaries use it.
1132 */
1133 static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1134 size_t count, loff_t *ppos)
1135 {
1136 char buffer[PROC_NUMBUF];
1137 int oom_adj;
1138 int err;
1139
1140 memset(buffer, 0, sizeof(buffer));
1141 if (count > sizeof(buffer) - 1)
1142 count = sizeof(buffer) - 1;
1143 if (copy_from_user(buffer, buf, count)) {
1144 err = -EFAULT;
1145 goto out;
1146 }
1147
1148 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1149 if (err)
1150 goto out;
1151 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1152 oom_adj != OOM_DISABLE) {
1153 err = -EINVAL;
1154 goto out;
1155 }
1156
1157 /*
1158 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1159 * value is always attainable.
1160 */
1161 if (oom_adj == OOM_ADJUST_MAX)
1162 oom_adj = OOM_SCORE_ADJ_MAX;
1163 else
1164 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1165
1166 err = __set_oom_adj(file, oom_adj, true);
1167 out:
1168 return err < 0 ? err : count;
1169 }
1170
1171 static const struct file_operations proc_oom_adj_operations = {
1172 .read = oom_adj_read,
1173 .write = oom_adj_write,
1174 .llseek = generic_file_llseek,
1175 };
1176
1177 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1178 size_t count, loff_t *ppos)
1179 {
1180 struct task_struct *task = get_proc_task(file_inode(file));
1181 char buffer[PROC_NUMBUF];
1182 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1183 size_t len;
1184
1185 if (!task)
1186 return -ESRCH;
1187 oom_score_adj = task->signal->oom_score_adj;
1188 put_task_struct(task);
1189 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1190 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1191 }
1192
1193 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1194 size_t count, loff_t *ppos)
1195 {
1196 char buffer[PROC_NUMBUF];
1197 int oom_score_adj;
1198 int err;
1199
1200 memset(buffer, 0, sizeof(buffer));
1201 if (count > sizeof(buffer) - 1)
1202 count = sizeof(buffer) - 1;
1203 if (copy_from_user(buffer, buf, count)) {
1204 err = -EFAULT;
1205 goto out;
1206 }
1207
1208 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1209 if (err)
1210 goto out;
1211 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1212 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1213 err = -EINVAL;
1214 goto out;
1215 }
1216
1217 err = __set_oom_adj(file, oom_score_adj, false);
1218 out:
1219 return err < 0 ? err : count;
1220 }
1221
1222 static const struct file_operations proc_oom_score_adj_operations = {
1223 .read = oom_score_adj_read,
1224 .write = oom_score_adj_write,
1225 .llseek = default_llseek,
1226 };
1227
1228 #ifdef CONFIG_AUDIT
1229 #define TMPBUFLEN 11
1230 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1231 size_t count, loff_t *ppos)
1232 {
1233 struct inode * inode = file_inode(file);
1234 struct task_struct *task = get_proc_task(inode);
1235 ssize_t length;
1236 char tmpbuf[TMPBUFLEN];
1237
1238 if (!task)
1239 return -ESRCH;
1240 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1241 from_kuid(file->f_cred->user_ns,
1242 audit_get_loginuid(task)));
1243 put_task_struct(task);
1244 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1245 }
1246
1247 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1248 size_t count, loff_t *ppos)
1249 {
1250 struct inode * inode = file_inode(file);
1251 uid_t loginuid;
1252 kuid_t kloginuid;
1253 int rv;
1254
1255 rcu_read_lock();
1256 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1257 rcu_read_unlock();
1258 return -EPERM;
1259 }
1260 rcu_read_unlock();
1261
1262 if (*ppos != 0) {
1263 /* No partial writes. */
1264 return -EINVAL;
1265 }
1266
1267 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1268 if (rv < 0)
1269 return rv;
1270
1271 /* is userspace tring to explicitly UNSET the loginuid? */
1272 if (loginuid == AUDIT_UID_UNSET) {
1273 kloginuid = INVALID_UID;
1274 } else {
1275 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1276 if (!uid_valid(kloginuid))
1277 return -EINVAL;
1278 }
1279
1280 rv = audit_set_loginuid(kloginuid);
1281 if (rv < 0)
1282 return rv;
1283 return count;
1284 }
1285
1286 static const struct file_operations proc_loginuid_operations = {
1287 .read = proc_loginuid_read,
1288 .write = proc_loginuid_write,
1289 .llseek = generic_file_llseek,
1290 };
1291
1292 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1293 size_t count, loff_t *ppos)
1294 {
1295 struct inode * inode = file_inode(file);
1296 struct task_struct *task = get_proc_task(inode);
1297 ssize_t length;
1298 char tmpbuf[TMPBUFLEN];
1299
1300 if (!task)
1301 return -ESRCH;
1302 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1303 audit_get_sessionid(task));
1304 put_task_struct(task);
1305 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1306 }
1307
1308 static const struct file_operations proc_sessionid_operations = {
1309 .read = proc_sessionid_read,
1310 .llseek = generic_file_llseek,
1311 };
1312 #endif
1313
1314 #ifdef CONFIG_FAULT_INJECTION
1315 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1316 size_t count, loff_t *ppos)
1317 {
1318 struct task_struct *task = get_proc_task(file_inode(file));
1319 char buffer[PROC_NUMBUF];
1320 size_t len;
1321 int make_it_fail;
1322
1323 if (!task)
1324 return -ESRCH;
1325 make_it_fail = task->make_it_fail;
1326 put_task_struct(task);
1327
1328 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1329
1330 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1331 }
1332
1333 static ssize_t proc_fault_inject_write(struct file * file,
1334 const char __user * buf, size_t count, loff_t *ppos)
1335 {
1336 struct task_struct *task;
1337 char buffer[PROC_NUMBUF];
1338 int make_it_fail;
1339 int rv;
1340
1341 if (!capable(CAP_SYS_RESOURCE))
1342 return -EPERM;
1343 memset(buffer, 0, sizeof(buffer));
1344 if (count > sizeof(buffer) - 1)
1345 count = sizeof(buffer) - 1;
1346 if (copy_from_user(buffer, buf, count))
1347 return -EFAULT;
1348 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1349 if (rv < 0)
1350 return rv;
1351 if (make_it_fail < 0 || make_it_fail > 1)
1352 return -EINVAL;
1353
1354 task = get_proc_task(file_inode(file));
1355 if (!task)
1356 return -ESRCH;
1357 task->make_it_fail = make_it_fail;
1358 put_task_struct(task);
1359
1360 return count;
1361 }
1362
1363 static const struct file_operations proc_fault_inject_operations = {
1364 .read = proc_fault_inject_read,
1365 .write = proc_fault_inject_write,
1366 .llseek = generic_file_llseek,
1367 };
1368
1369 static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1370 size_t count, loff_t *ppos)
1371 {
1372 struct task_struct *task;
1373 int err;
1374 unsigned int n;
1375
1376 err = kstrtouint_from_user(buf, count, 0, &n);
1377 if (err)
1378 return err;
1379
1380 task = get_proc_task(file_inode(file));
1381 if (!task)
1382 return -ESRCH;
1383 task->fail_nth = n;
1384 put_task_struct(task);
1385
1386 return count;
1387 }
1388
1389 static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1390 size_t count, loff_t *ppos)
1391 {
1392 struct task_struct *task;
1393 char numbuf[PROC_NUMBUF];
1394 ssize_t len;
1395
1396 task = get_proc_task(file_inode(file));
1397 if (!task)
1398 return -ESRCH;
1399 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1400 put_task_struct(task);
1401 return simple_read_from_buffer(buf, count, ppos, numbuf, len);
1402 }
1403
1404 static const struct file_operations proc_fail_nth_operations = {
1405 .read = proc_fail_nth_read,
1406 .write = proc_fail_nth_write,
1407 };
1408 #endif
1409
1410
1411 #ifdef CONFIG_SCHED_DEBUG
1412 /*
1413 * Print out various scheduling related per-task fields:
1414 */
1415 static int sched_show(struct seq_file *m, void *v)
1416 {
1417 struct inode *inode = m->private;
1418 struct pid_namespace *ns = proc_pid_ns(inode);
1419 struct task_struct *p;
1420
1421 p = get_proc_task(inode);
1422 if (!p)
1423 return -ESRCH;
1424 proc_sched_show_task(p, ns, m);
1425
1426 put_task_struct(p);
1427
1428 return 0;
1429 }
1430
1431 static ssize_t
1432 sched_write(struct file *file, const char __user *buf,
1433 size_t count, loff_t *offset)
1434 {
1435 struct inode *inode = file_inode(file);
1436 struct task_struct *p;
1437
1438 p = get_proc_task(inode);
1439 if (!p)
1440 return -ESRCH;
1441 proc_sched_set_task(p);
1442
1443 put_task_struct(p);
1444
1445 return count;
1446 }
1447
1448 static int sched_open(struct inode *inode, struct file *filp)
1449 {
1450 return single_open(filp, sched_show, inode);
1451 }
1452
1453 static const struct file_operations proc_pid_sched_operations = {
1454 .open = sched_open,
1455 .read = seq_read,
1456 .write = sched_write,
1457 .llseek = seq_lseek,
1458 .release = single_release,
1459 };
1460
1461 #endif
1462
1463 #ifdef CONFIG_SCHED_AUTOGROUP
1464 /*
1465 * Print out autogroup related information:
1466 */
1467 static int sched_autogroup_show(struct seq_file *m, void *v)
1468 {
1469 struct inode *inode = m->private;
1470 struct task_struct *p;
1471
1472 p = get_proc_task(inode);
1473 if (!p)
1474 return -ESRCH;
1475 proc_sched_autogroup_show_task(p, m);
1476
1477 put_task_struct(p);
1478
1479 return 0;
1480 }
1481
1482 static ssize_t
1483 sched_autogroup_write(struct file *file, const char __user *buf,
1484 size_t count, loff_t *offset)
1485 {
1486 struct inode *inode = file_inode(file);
1487 struct task_struct *p;
1488 char buffer[PROC_NUMBUF];
1489 int nice;
1490 int err;
1491
1492 memset(buffer, 0, sizeof(buffer));
1493 if (count > sizeof(buffer) - 1)
1494 count = sizeof(buffer) - 1;
1495 if (copy_from_user(buffer, buf, count))
1496 return -EFAULT;
1497
1498 err = kstrtoint(strstrip(buffer), 0, &nice);
1499 if (err < 0)
1500 return err;
1501
1502 p = get_proc_task(inode);
1503 if (!p)
1504 return -ESRCH;
1505
1506 err = proc_sched_autogroup_set_nice(p, nice);
1507 if (err)
1508 count = err;
1509
1510 put_task_struct(p);
1511
1512 return count;
1513 }
1514
1515 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1516 {
1517 int ret;
1518
1519 ret = single_open(filp, sched_autogroup_show, NULL);
1520 if (!ret) {
1521 struct seq_file *m = filp->private_data;
1522
1523 m->private = inode;
1524 }
1525 return ret;
1526 }
1527
1528 static const struct file_operations proc_pid_sched_autogroup_operations = {
1529 .open = sched_autogroup_open,
1530 .read = seq_read,
1531 .write = sched_autogroup_write,
1532 .llseek = seq_lseek,
1533 .release = single_release,
1534 };
1535
1536 #endif /* CONFIG_SCHED_AUTOGROUP */
1537
1538 #ifdef CONFIG_TIME_NS
1539 static int timens_offsets_show(struct seq_file *m, void *v)
1540 {
1541 struct task_struct *p;
1542
1543 p = get_proc_task(file_inode(m->file));
1544 if (!p)
1545 return -ESRCH;
1546 proc_timens_show_offsets(p, m);
1547
1548 put_task_struct(p);
1549
1550 return 0;
1551 }
1552
1553 static ssize_t timens_offsets_write(struct file *file, const char __user *buf,
1554 size_t count, loff_t *ppos)
1555 {
1556 struct inode *inode = file_inode(file);
1557 struct proc_timens_offset offsets[2];
1558 char *kbuf = NULL, *pos, *next_line;
1559 struct task_struct *p;
1560 int ret, noffsets;
1561
1562 /* Only allow < page size writes at the beginning of the file */
1563 if ((*ppos != 0) || (count >= PAGE_SIZE))
1564 return -EINVAL;
1565
1566 /* Slurp in the user data */
1567 kbuf = memdup_user_nul(buf, count);
1568 if (IS_ERR(kbuf))
1569 return PTR_ERR(kbuf);
1570
1571 /* Parse the user data */
1572 ret = -EINVAL;
1573 noffsets = 0;
1574 for (pos = kbuf; pos; pos = next_line) {
1575 struct proc_timens_offset *off = &offsets[noffsets];
1576 int err;
1577
1578 /* Find the end of line and ensure we don't look past it */
1579 next_line = strchr(pos, '\n');
1580 if (next_line) {
1581 *next_line = '\0';
1582 next_line++;
1583 if (*next_line == '\0')
1584 next_line = NULL;
1585 }
1586
1587 err = sscanf(pos, "%u %lld %lu", &off->clockid,
1588 &off->val.tv_sec, &off->val.tv_nsec);
1589 if (err != 3 || off->val.tv_nsec >= NSEC_PER_SEC)
1590 goto out;
1591 noffsets++;
1592 if (noffsets == ARRAY_SIZE(offsets)) {
1593 if (next_line)
1594 count = next_line - kbuf;
1595 break;
1596 }
1597 }
1598
1599 ret = -ESRCH;
1600 p = get_proc_task(inode);
1601 if (!p)
1602 goto out;
1603 ret = proc_timens_set_offset(file, p, offsets, noffsets);
1604 put_task_struct(p);
1605 if (ret)
1606 goto out;
1607
1608 ret = count;
1609 out:
1610 kfree(kbuf);
1611 return ret;
1612 }
1613
1614 static int timens_offsets_open(struct inode *inode, struct file *filp)
1615 {
1616 return single_open(filp, timens_offsets_show, inode);
1617 }
1618
1619 static const struct file_operations proc_timens_offsets_operations = {
1620 .open = timens_offsets_open,
1621 .read = seq_read,
1622 .write = timens_offsets_write,
1623 .llseek = seq_lseek,
1624 .release = single_release,
1625 };
1626 #endif /* CONFIG_TIME_NS */
1627
1628 static ssize_t comm_write(struct file *file, const char __user *buf,
1629 size_t count, loff_t *offset)
1630 {
1631 struct inode *inode = file_inode(file);
1632 struct task_struct *p;
1633 char buffer[TASK_COMM_LEN];
1634 const size_t maxlen = sizeof(buffer) - 1;
1635
1636 memset(buffer, 0, sizeof(buffer));
1637 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1638 return -EFAULT;
1639
1640 p = get_proc_task(inode);
1641 if (!p)
1642 return -ESRCH;
1643
1644 if (same_thread_group(current, p))
1645 set_task_comm(p, buffer);
1646 else
1647 count = -EINVAL;
1648
1649 put_task_struct(p);
1650
1651 return count;
1652 }
1653
1654 static int comm_show(struct seq_file *m, void *v)
1655 {
1656 struct inode *inode = m->private;
1657 struct task_struct *p;
1658
1659 p = get_proc_task(inode);
1660 if (!p)
1661 return -ESRCH;
1662
1663 proc_task_name(m, p, false);
1664 seq_putc(m, '\n');
1665
1666 put_task_struct(p);
1667
1668 return 0;
1669 }
1670
1671 static int comm_open(struct inode *inode, struct file *filp)
1672 {
1673 return single_open(filp, comm_show, inode);
1674 }
1675
1676 static const struct file_operations proc_pid_set_comm_operations = {
1677 .open = comm_open,
1678 .read = seq_read,
1679 .write = comm_write,
1680 .llseek = seq_lseek,
1681 .release = single_release,
1682 };
1683
1684 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1685 {
1686 struct task_struct *task;
1687 struct file *exe_file;
1688
1689 task = get_proc_task(d_inode(dentry));
1690 if (!task)
1691 return -ENOENT;
1692 exe_file = get_task_exe_file(task);
1693 put_task_struct(task);
1694 if (exe_file) {
1695 *exe_path = exe_file->f_path;
1696 path_get(&exe_file->f_path);
1697 fput(exe_file);
1698 return 0;
1699 } else
1700 return -ENOENT;
1701 }
1702
1703 static const char *proc_pid_get_link(struct dentry *dentry,
1704 struct inode *inode,
1705 struct delayed_call *done)
1706 {
1707 struct path path;
1708 int error = -EACCES;
1709
1710 if (!dentry)
1711 return ERR_PTR(-ECHILD);
1712
1713 /* Are we allowed to snoop on the tasks file descriptors? */
1714 if (!proc_fd_access_allowed(inode))
1715 goto out;
1716
1717 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1718 if (error)
1719 goto out;
1720
1721 error = nd_jump_link(&path);
1722 out:
1723 return ERR_PTR(error);
1724 }
1725
1726 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1727 {
1728 char *tmp = (char *)__get_free_page(GFP_KERNEL);
1729 char *pathname;
1730 int len;
1731
1732 if (!tmp)
1733 return -ENOMEM;
1734
1735 pathname = d_path(path, tmp, PAGE_SIZE);
1736 len = PTR_ERR(pathname);
1737 if (IS_ERR(pathname))
1738 goto out;
1739 len = tmp + PAGE_SIZE - 1 - pathname;
1740
1741 if (len > buflen)
1742 len = buflen;
1743 if (copy_to_user(buffer, pathname, len))
1744 len = -EFAULT;
1745 out:
1746 free_page((unsigned long)tmp);
1747 return len;
1748 }
1749
1750 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1751 {
1752 int error = -EACCES;
1753 struct inode *inode = d_inode(dentry);
1754 struct path path;
1755
1756 /* Are we allowed to snoop on the tasks file descriptors? */
1757 if (!proc_fd_access_allowed(inode))
1758 goto out;
1759
1760 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1761 if (error)
1762 goto out;
1763
1764 error = do_proc_readlink(&path, buffer, buflen);
1765 path_put(&path);
1766 out:
1767 return error;
1768 }
1769
1770 const struct inode_operations proc_pid_link_inode_operations = {
1771 .readlink = proc_pid_readlink,
1772 .get_link = proc_pid_get_link,
1773 .setattr = proc_setattr,
1774 };
1775
1776
1777 /* building an inode */
1778
1779 void task_dump_owner(struct task_struct *task, umode_t mode,
1780 kuid_t *ruid, kgid_t *rgid)
1781 {
1782 /* Depending on the state of dumpable compute who should own a
1783 * proc file for a task.
1784 */
1785 const struct cred *cred;
1786 kuid_t uid;
1787 kgid_t gid;
1788
1789 if (unlikely(task->flags & PF_KTHREAD)) {
1790 *ruid = GLOBAL_ROOT_UID;
1791 *rgid = GLOBAL_ROOT_GID;
1792 return;
1793 }
1794
1795 /* Default to the tasks effective ownership */
1796 rcu_read_lock();
1797 cred = __task_cred(task);
1798 uid = cred->euid;
1799 gid = cred->egid;
1800 rcu_read_unlock();
1801
1802 /*
1803 * Before the /proc/pid/status file was created the only way to read
1804 * the effective uid of a /process was to stat /proc/pid. Reading
1805 * /proc/pid/status is slow enough that procps and other packages
1806 * kept stating /proc/pid. To keep the rules in /proc simple I have
1807 * made this apply to all per process world readable and executable
1808 * directories.
1809 */
1810 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1811 struct mm_struct *mm;
1812 task_lock(task);
1813 mm = task->mm;
1814 /* Make non-dumpable tasks owned by some root */
1815 if (mm) {
1816 if (get_dumpable(mm) != SUID_DUMP_USER) {
1817 struct user_namespace *user_ns = mm->user_ns;
1818
1819 uid = make_kuid(user_ns, 0);
1820 if (!uid_valid(uid))
1821 uid = GLOBAL_ROOT_UID;
1822
1823 gid = make_kgid(user_ns, 0);
1824 if (!gid_valid(gid))
1825 gid = GLOBAL_ROOT_GID;
1826 }
1827 } else {
1828 uid = GLOBAL_ROOT_UID;
1829 gid = GLOBAL_ROOT_GID;
1830 }
1831 task_unlock(task);
1832 }
1833 *ruid = uid;
1834 *rgid = gid;
1835 }
1836
1837 struct inode *proc_pid_make_inode(struct super_block * sb,
1838 struct task_struct *task, umode_t mode)
1839 {
1840 struct inode * inode;
1841 struct proc_inode *ei;
1842
1843 /* We need a new inode */
1844
1845 inode = new_inode(sb);
1846 if (!inode)
1847 goto out;
1848
1849 /* Common stuff */
1850 ei = PROC_I(inode);
1851 inode->i_mode = mode;
1852 inode->i_ino = get_next_ino();
1853 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1854 inode->i_op = &proc_def_inode_operations;
1855
1856 /*
1857 * grab the reference to task.
1858 */
1859 ei->pid = get_task_pid(task, PIDTYPE_PID);
1860 if (!ei->pid)
1861 goto out_unlock;
1862
1863 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1864 security_task_to_inode(task, inode);
1865
1866 out:
1867 return inode;
1868
1869 out_unlock:
1870 iput(inode);
1871 return NULL;
1872 }
1873
1874 int pid_getattr(const struct path *path, struct kstat *stat,
1875 u32 request_mask, unsigned int query_flags)
1876 {
1877 struct inode *inode = d_inode(path->dentry);
1878 struct pid_namespace *pid = proc_pid_ns(inode);
1879 struct task_struct *task;
1880
1881 generic_fillattr(inode, stat);
1882
1883 stat->uid = GLOBAL_ROOT_UID;
1884 stat->gid = GLOBAL_ROOT_GID;
1885 rcu_read_lock();
1886 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1887 if (task) {
1888 if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) {
1889 rcu_read_unlock();
1890 /*
1891 * This doesn't prevent learning whether PID exists,
1892 * it only makes getattr() consistent with readdir().
1893 */
1894 return -ENOENT;
1895 }
1896 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1897 }
1898 rcu_read_unlock();
1899 return 0;
1900 }
1901
1902 /* dentry stuff */
1903
1904 /*
1905 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
1906 */
1907 void pid_update_inode(struct task_struct *task, struct inode *inode)
1908 {
1909 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1910
1911 inode->i_mode &= ~(S_ISUID | S_ISGID);
1912 security_task_to_inode(task, inode);
1913 }
1914
1915 /*
1916 * Rewrite the inode's ownerships here because the owning task may have
1917 * performed a setuid(), etc.
1918 *
1919 */
1920 static int pid_revalidate(struct dentry *dentry, unsigned int flags)
1921 {
1922 struct inode *inode;
1923 struct task_struct *task;
1924
1925 if (flags & LOOKUP_RCU)
1926 return -ECHILD;
1927
1928 inode = d_inode(dentry);
1929 task = get_proc_task(inode);
1930
1931 if (task) {
1932 pid_update_inode(task, inode);
1933 put_task_struct(task);
1934 return 1;
1935 }
1936 return 0;
1937 }
1938
1939 static inline bool proc_inode_is_dead(struct inode *inode)
1940 {
1941 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1942 }
1943
1944 int pid_delete_dentry(const struct dentry *dentry)
1945 {
1946 /* Is the task we represent dead?
1947 * If so, then don't put the dentry on the lru list,
1948 * kill it immediately.
1949 */
1950 return proc_inode_is_dead(d_inode(dentry));
1951 }
1952
1953 const struct dentry_operations pid_dentry_operations =
1954 {
1955 .d_revalidate = pid_revalidate,
1956 .d_delete = pid_delete_dentry,
1957 };
1958
1959 /* Lookups */
1960
1961 /*
1962 * Fill a directory entry.
1963 *
1964 * If possible create the dcache entry and derive our inode number and
1965 * file type from dcache entry.
1966 *
1967 * Since all of the proc inode numbers are dynamically generated, the inode
1968 * numbers do not exist until the inode is cache. This means creating the
1969 * the dcache entry in readdir is necessary to keep the inode numbers
1970 * reported by readdir in sync with the inode numbers reported
1971 * by stat.
1972 */
1973 bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1974 const char *name, unsigned int len,
1975 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1976 {
1977 struct dentry *child, *dir = file->f_path.dentry;
1978 struct qstr qname = QSTR_INIT(name, len);
1979 struct inode *inode;
1980 unsigned type = DT_UNKNOWN;
1981 ino_t ino = 1;
1982
1983 child = d_hash_and_lookup(dir, &qname);
1984 if (!child) {
1985 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
1986 child = d_alloc_parallel(dir, &qname, &wq);
1987 if (IS_ERR(child))
1988 goto end_instantiate;
1989 if (d_in_lookup(child)) {
1990 struct dentry *res;
1991 res = instantiate(child, task, ptr);
1992 d_lookup_done(child);
1993 if (unlikely(res)) {
1994 dput(child);
1995 child = res;
1996 if (IS_ERR(child))
1997 goto end_instantiate;
1998 }
1999 }
2000 }
2001 inode = d_inode(child);
2002 ino = inode->i_ino;
2003 type = inode->i_mode >> 12;
2004 dput(child);
2005 end_instantiate:
2006 return dir_emit(ctx, name, len, ino, type);
2007 }
2008
2009 /*
2010 * dname_to_vma_addr - maps a dentry name into two unsigned longs
2011 * which represent vma start and end addresses.
2012 */
2013 static int dname_to_vma_addr(struct dentry *dentry,
2014 unsigned long *start, unsigned long *end)
2015 {
2016 const char *str = dentry->d_name.name;
2017 unsigned long long sval, eval;
2018 unsigned int len;
2019
2020 if (str[0] == '0' && str[1] != '-')
2021 return -EINVAL;
2022 len = _parse_integer(str, 16, &sval);
2023 if (len & KSTRTOX_OVERFLOW)
2024 return -EINVAL;
2025 if (sval != (unsigned long)sval)
2026 return -EINVAL;
2027 str += len;
2028
2029 if (*str != '-')
2030 return -EINVAL;
2031 str++;
2032
2033 if (str[0] == '0' && str[1])
2034 return -EINVAL;
2035 len = _parse_integer(str, 16, &eval);
2036 if (len & KSTRTOX_OVERFLOW)
2037 return -EINVAL;
2038 if (eval != (unsigned long)eval)
2039 return -EINVAL;
2040 str += len;
2041
2042 if (*str != '\0')
2043 return -EINVAL;
2044
2045 *start = sval;
2046 *end = eval;
2047
2048 return 0;
2049 }
2050
2051 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
2052 {
2053 unsigned long vm_start, vm_end;
2054 bool exact_vma_exists = false;
2055 struct mm_struct *mm = NULL;
2056 struct task_struct *task;
2057 struct inode *inode;
2058 int status = 0;
2059
2060 if (flags & LOOKUP_RCU)
2061 return -ECHILD;
2062
2063 inode = d_inode(dentry);
2064 task = get_proc_task(inode);
2065 if (!task)
2066 goto out_notask;
2067
2068 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
2069 if (IS_ERR_OR_NULL(mm))
2070 goto out;
2071
2072 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2073 status = down_read_killable(&mm->mmap_sem);
2074 if (!status) {
2075 exact_vma_exists = !!find_exact_vma(mm, vm_start,
2076 vm_end);
2077 up_read(&mm->mmap_sem);
2078 }
2079 }
2080
2081 mmput(mm);
2082
2083 if (exact_vma_exists) {
2084 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
2085
2086 security_task_to_inode(task, inode);
2087 status = 1;
2088 }
2089
2090 out:
2091 put_task_struct(task);
2092
2093 out_notask:
2094 return status;
2095 }
2096
2097 static const struct dentry_operations tid_map_files_dentry_operations = {
2098 .d_revalidate = map_files_d_revalidate,
2099 .d_delete = pid_delete_dentry,
2100 };
2101
2102 static int map_files_get_link(struct dentry *dentry, struct path *path)
2103 {
2104 unsigned long vm_start, vm_end;
2105 struct vm_area_struct *vma;
2106 struct task_struct *task;
2107 struct mm_struct *mm;
2108 int rc;
2109
2110 rc = -ENOENT;
2111 task = get_proc_task(d_inode(dentry));
2112 if (!task)
2113 goto out;
2114
2115 mm = get_task_mm(task);
2116 put_task_struct(task);
2117 if (!mm)
2118 goto out;
2119
2120 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2121 if (rc)
2122 goto out_mmput;
2123
2124 rc = down_read_killable(&mm->mmap_sem);
2125 if (rc)
2126 goto out_mmput;
2127
2128 rc = -ENOENT;
2129 vma = find_exact_vma(mm, vm_start, vm_end);
2130 if (vma && vma->vm_file) {
2131 *path = vma->vm_file->f_path;
2132 path_get(path);
2133 rc = 0;
2134 }
2135 up_read(&mm->mmap_sem);
2136
2137 out_mmput:
2138 mmput(mm);
2139 out:
2140 return rc;
2141 }
2142
2143 struct map_files_info {
2144 unsigned long start;
2145 unsigned long end;
2146 fmode_t mode;
2147 };
2148
2149 /*
2150 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
2151 * symlinks may be used to bypass permissions on ancestor directories in the
2152 * path to the file in question.
2153 */
2154 static const char *
2155 proc_map_files_get_link(struct dentry *dentry,
2156 struct inode *inode,
2157 struct delayed_call *done)
2158 {
2159 if (!capable(CAP_SYS_ADMIN))
2160 return ERR_PTR(-EPERM);
2161
2162 return proc_pid_get_link(dentry, inode, done);
2163 }
2164
2165 /*
2166 * Identical to proc_pid_link_inode_operations except for get_link()
2167 */
2168 static const struct inode_operations proc_map_files_link_inode_operations = {
2169 .readlink = proc_pid_readlink,
2170 .get_link = proc_map_files_get_link,
2171 .setattr = proc_setattr,
2172 };
2173
2174 static struct dentry *
2175 proc_map_files_instantiate(struct dentry *dentry,
2176 struct task_struct *task, const void *ptr)
2177 {
2178 fmode_t mode = (fmode_t)(unsigned long)ptr;
2179 struct proc_inode *ei;
2180 struct inode *inode;
2181
2182 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
2183 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2184 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2185 if (!inode)
2186 return ERR_PTR(-ENOENT);
2187
2188 ei = PROC_I(inode);
2189 ei->op.proc_get_link = map_files_get_link;
2190
2191 inode->i_op = &proc_map_files_link_inode_operations;
2192 inode->i_size = 64;
2193
2194 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2195 return d_splice_alias(inode, dentry);
2196 }
2197
2198 static struct dentry *proc_map_files_lookup(struct inode *dir,
2199 struct dentry *dentry, unsigned int flags)
2200 {
2201 unsigned long vm_start, vm_end;
2202 struct vm_area_struct *vma;
2203 struct task_struct *task;
2204 struct dentry *result;
2205 struct mm_struct *mm;
2206
2207 result = ERR_PTR(-ENOENT);
2208 task = get_proc_task(dir);
2209 if (!task)
2210 goto out;
2211
2212 result = ERR_PTR(-EACCES);
2213 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2214 goto out_put_task;
2215
2216 result = ERR_PTR(-ENOENT);
2217 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2218 goto out_put_task;
2219
2220 mm = get_task_mm(task);
2221 if (!mm)
2222 goto out_put_task;
2223
2224 result = ERR_PTR(-EINTR);
2225 if (down_read_killable(&mm->mmap_sem))
2226 goto out_put_mm;
2227
2228 result = ERR_PTR(-ENOENT);
2229 vma = find_exact_vma(mm, vm_start, vm_end);
2230 if (!vma)
2231 goto out_no_vma;
2232
2233 if (vma->vm_file)
2234 result = proc_map_files_instantiate(dentry, task,
2235 (void *)(unsigned long)vma->vm_file->f_mode);
2236
2237 out_no_vma:
2238 up_read(&mm->mmap_sem);
2239 out_put_mm:
2240 mmput(mm);
2241 out_put_task:
2242 put_task_struct(task);
2243 out:
2244 return result;
2245 }
2246
2247 static const struct inode_operations proc_map_files_inode_operations = {
2248 .lookup = proc_map_files_lookup,
2249 .permission = proc_fd_permission,
2250 .setattr = proc_setattr,
2251 };
2252
2253 static int
2254 proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2255 {
2256 struct vm_area_struct *vma;
2257 struct task_struct *task;
2258 struct mm_struct *mm;
2259 unsigned long nr_files, pos, i;
2260 GENRADIX(struct map_files_info) fa;
2261 struct map_files_info *p;
2262 int ret;
2263
2264 genradix_init(&fa);
2265
2266 ret = -ENOENT;
2267 task = get_proc_task(file_inode(file));
2268 if (!task)
2269 goto out;
2270
2271 ret = -EACCES;
2272 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2273 goto out_put_task;
2274
2275 ret = 0;
2276 if (!dir_emit_dots(file, ctx))
2277 goto out_put_task;
2278
2279 mm = get_task_mm(task);
2280 if (!mm)
2281 goto out_put_task;
2282
2283 ret = down_read_killable(&mm->mmap_sem);
2284 if (ret) {
2285 mmput(mm);
2286 goto out_put_task;
2287 }
2288
2289 nr_files = 0;
2290
2291 /*
2292 * We need two passes here:
2293 *
2294 * 1) Collect vmas of mapped files with mmap_sem taken
2295 * 2) Release mmap_sem and instantiate entries
2296 *
2297 * otherwise we get lockdep complained, since filldir()
2298 * routine might require mmap_sem taken in might_fault().
2299 */
2300
2301 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2302 if (!vma->vm_file)
2303 continue;
2304 if (++pos <= ctx->pos)
2305 continue;
2306
2307 p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
2308 if (!p) {
2309 ret = -ENOMEM;
2310 up_read(&mm->mmap_sem);
2311 mmput(mm);
2312 goto out_put_task;
2313 }
2314
2315 p->start = vma->vm_start;
2316 p->end = vma->vm_end;
2317 p->mode = vma->vm_file->f_mode;
2318 }
2319 up_read(&mm->mmap_sem);
2320 mmput(mm);
2321
2322 for (i = 0; i < nr_files; i++) {
2323 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2324 unsigned int len;
2325
2326 p = genradix_ptr(&fa, i);
2327 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2328 if (!proc_fill_cache(file, ctx,
2329 buf, len,
2330 proc_map_files_instantiate,
2331 task,
2332 (void *)(unsigned long)p->mode))
2333 break;
2334 ctx->pos++;
2335 }
2336
2337 out_put_task:
2338 put_task_struct(task);
2339 out:
2340 genradix_free(&fa);
2341 return ret;
2342 }
2343
2344 static const struct file_operations proc_map_files_operations = {
2345 .read = generic_read_dir,
2346 .iterate_shared = proc_map_files_readdir,
2347 .llseek = generic_file_llseek,
2348 };
2349
2350 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2351 struct timers_private {
2352 struct pid *pid;
2353 struct task_struct *task;
2354 struct sighand_struct *sighand;
2355 struct pid_namespace *ns;
2356 unsigned long flags;
2357 };
2358
2359 static void *timers_start(struct seq_file *m, loff_t *pos)
2360 {
2361 struct timers_private *tp = m->private;
2362
2363 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2364 if (!tp->task)
2365 return ERR_PTR(-ESRCH);
2366
2367 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2368 if (!tp->sighand)
2369 return ERR_PTR(-ESRCH);
2370
2371 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2372 }
2373
2374 static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2375 {
2376 struct timers_private *tp = m->private;
2377 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2378 }
2379
2380 static void timers_stop(struct seq_file *m, void *v)
2381 {
2382 struct timers_private *tp = m->private;
2383
2384 if (tp->sighand) {
2385 unlock_task_sighand(tp->task, &tp->flags);
2386 tp->sighand = NULL;
2387 }
2388
2389 if (tp->task) {
2390 put_task_struct(tp->task);
2391 tp->task = NULL;
2392 }
2393 }
2394
2395 static int show_timer(struct seq_file *m, void *v)
2396 {
2397 struct k_itimer *timer;
2398 struct timers_private *tp = m->private;
2399 int notify;
2400 static const char * const nstr[] = {
2401 [SIGEV_SIGNAL] = "signal",
2402 [SIGEV_NONE] = "none",
2403 [SIGEV_THREAD] = "thread",
2404 };
2405
2406 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2407 notify = timer->it_sigev_notify;
2408
2409 seq_printf(m, "ID: %d\n", timer->it_id);
2410 seq_printf(m, "signal: %d/%px\n",
2411 timer->sigq->info.si_signo,
2412 timer->sigq->info.si_value.sival_ptr);
2413 seq_printf(m, "notify: %s/%s.%d\n",
2414 nstr[notify & ~SIGEV_THREAD_ID],
2415 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2416 pid_nr_ns(timer->it_pid, tp->ns));
2417 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2418
2419 return 0;
2420 }
2421
2422 static const struct seq_operations proc_timers_seq_ops = {
2423 .start = timers_start,
2424 .next = timers_next,
2425 .stop = timers_stop,
2426 .show = show_timer,
2427 };
2428
2429 static int proc_timers_open(struct inode *inode, struct file *file)
2430 {
2431 struct timers_private *tp;
2432
2433 tp = __seq_open_private(file, &proc_timers_seq_ops,
2434 sizeof(struct timers_private));
2435 if (!tp)
2436 return -ENOMEM;
2437
2438 tp->pid = proc_pid(inode);
2439 tp->ns = proc_pid_ns(inode);
2440 return 0;
2441 }
2442
2443 static const struct file_operations proc_timers_operations = {
2444 .open = proc_timers_open,
2445 .read = seq_read,
2446 .llseek = seq_lseek,
2447 .release = seq_release_private,
2448 };
2449 #endif
2450
2451 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2452 size_t count, loff_t *offset)
2453 {
2454 struct inode *inode = file_inode(file);
2455 struct task_struct *p;
2456 u64 slack_ns;
2457 int err;
2458
2459 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2460 if (err < 0)
2461 return err;
2462
2463 p = get_proc_task(inode);
2464 if (!p)
2465 return -ESRCH;
2466
2467 if (p != current) {
2468 rcu_read_lock();
2469 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2470 rcu_read_unlock();
2471 count = -EPERM;
2472 goto out;
2473 }
2474 rcu_read_unlock();
2475
2476 err = security_task_setscheduler(p);
2477 if (err) {
2478 count = err;
2479 goto out;
2480 }
2481 }
2482
2483 task_lock(p);
2484 if (slack_ns == 0)
2485 p->timer_slack_ns = p->default_timer_slack_ns;
2486 else
2487 p->timer_slack_ns = slack_ns;
2488 task_unlock(p);
2489
2490 out:
2491 put_task_struct(p);
2492
2493 return count;
2494 }
2495
2496 static int timerslack_ns_show(struct seq_file *m, void *v)
2497 {
2498 struct inode *inode = m->private;
2499 struct task_struct *p;
2500 int err = 0;
2501
2502 p = get_proc_task(inode);
2503 if (!p)
2504 return -ESRCH;
2505
2506 if (p != current) {
2507 rcu_read_lock();
2508 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2509 rcu_read_unlock();
2510 err = -EPERM;
2511 goto out;
2512 }
2513 rcu_read_unlock();
2514
2515 err = security_task_getscheduler(p);
2516 if (err)
2517 goto out;
2518 }
2519
2520 task_lock(p);
2521 seq_printf(m, "%llu\n", p->timer_slack_ns);
2522 task_unlock(p);
2523
2524 out:
2525 put_task_struct(p);
2526
2527 return err;
2528 }
2529
2530 static int timerslack_ns_open(struct inode *inode, struct file *filp)
2531 {
2532 return single_open(filp, timerslack_ns_show, inode);
2533 }
2534
2535 static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2536 .open = timerslack_ns_open,
2537 .read = seq_read,
2538 .write = timerslack_ns_write,
2539 .llseek = seq_lseek,
2540 .release = single_release,
2541 };
2542
2543 static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2544 struct task_struct *task, const void *ptr)
2545 {
2546 const struct pid_entry *p = ptr;
2547 struct inode *inode;
2548 struct proc_inode *ei;
2549
2550 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
2551 if (!inode)
2552 return ERR_PTR(-ENOENT);
2553
2554 ei = PROC_I(inode);
2555 if (S_ISDIR(inode->i_mode))
2556 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2557 if (p->iop)
2558 inode->i_op = p->iop;
2559 if (p->fop)
2560 inode->i_fop = p->fop;
2561 ei->op = p->op;
2562 pid_update_inode(task, inode);
2563 d_set_d_op(dentry, &pid_dentry_operations);
2564 return d_splice_alias(inode, dentry);
2565 }
2566
2567 static struct dentry *proc_pident_lookup(struct inode *dir,
2568 struct dentry *dentry,
2569 const struct pid_entry *p,
2570 const struct pid_entry *end)
2571 {
2572 struct task_struct *task = get_proc_task(dir);
2573 struct dentry *res = ERR_PTR(-ENOENT);
2574
2575 if (!task)
2576 goto out_no_task;
2577
2578 /*
2579 * Yes, it does not scale. And it should not. Don't add
2580 * new entries into /proc/<tgid>/ without very good reasons.
2581 */
2582 for (; p < end; p++) {
2583 if (p->len != dentry->d_name.len)
2584 continue;
2585 if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2586 res = proc_pident_instantiate(dentry, task, p);
2587 break;
2588 }
2589 }
2590 put_task_struct(task);
2591 out_no_task:
2592 return res;
2593 }
2594
2595 static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2596 const struct pid_entry *ents, unsigned int nents)
2597 {
2598 struct task_struct *task = get_proc_task(file_inode(file));
2599 const struct pid_entry *p;
2600
2601 if (!task)
2602 return -ENOENT;
2603
2604 if (!dir_emit_dots(file, ctx))
2605 goto out;
2606
2607 if (ctx->pos >= nents + 2)
2608 goto out;
2609
2610 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2611 if (!proc_fill_cache(file, ctx, p->name, p->len,
2612 proc_pident_instantiate, task, p))
2613 break;
2614 ctx->pos++;
2615 }
2616 out:
2617 put_task_struct(task);
2618 return 0;
2619 }
2620
2621 #ifdef CONFIG_SECURITY
2622 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2623 size_t count, loff_t *ppos)
2624 {
2625 struct inode * inode = file_inode(file);
2626 char *p = NULL;
2627 ssize_t length;
2628 struct task_struct *task = get_proc_task(inode);
2629
2630 if (!task)
2631 return -ESRCH;
2632
2633 length = security_getprocattr(task, PROC_I(inode)->op.lsm,
2634 (char*)file->f_path.dentry->d_name.name,
2635 &p);
2636 put_task_struct(task);
2637 if (length > 0)
2638 length = simple_read_from_buffer(buf, count, ppos, p, length);
2639 kfree(p);
2640 return length;
2641 }
2642
2643 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2644 size_t count, loff_t *ppos)
2645 {
2646 struct inode * inode = file_inode(file);
2647 struct task_struct *task;
2648 void *page;
2649 int rv;
2650
2651 rcu_read_lock();
2652 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2653 if (!task) {
2654 rcu_read_unlock();
2655 return -ESRCH;
2656 }
2657 /* A task may only write its own attributes. */
2658 if (current != task) {
2659 rcu_read_unlock();
2660 return -EACCES;
2661 }
2662 /* Prevent changes to overridden credentials. */
2663 if (current_cred() != current_real_cred()) {
2664 rcu_read_unlock();
2665 return -EBUSY;
2666 }
2667 rcu_read_unlock();
2668
2669 if (count > PAGE_SIZE)
2670 count = PAGE_SIZE;
2671
2672 /* No partial writes. */
2673 if (*ppos != 0)
2674 return -EINVAL;
2675
2676 page = memdup_user(buf, count);
2677 if (IS_ERR(page)) {
2678 rv = PTR_ERR(page);
2679 goto out;
2680 }
2681
2682 /* Guard against adverse ptrace interaction */
2683 rv = mutex_lock_interruptible(&current->signal->cred_guard_mutex);
2684 if (rv < 0)
2685 goto out_free;
2686
2687 rv = security_setprocattr(PROC_I(inode)->op.lsm,
2688 file->f_path.dentry->d_name.name, page,
2689 count);
2690 mutex_unlock(&current->signal->cred_guard_mutex);
2691 out_free:
2692 kfree(page);
2693 out:
2694 return rv;
2695 }
2696
2697 static const struct file_operations proc_pid_attr_operations = {
2698 .read = proc_pid_attr_read,
2699 .write = proc_pid_attr_write,
2700 .llseek = generic_file_llseek,
2701 };
2702
2703 #define LSM_DIR_OPS(LSM) \
2704 static int proc_##LSM##_attr_dir_iterate(struct file *filp, \
2705 struct dir_context *ctx) \
2706 { \
2707 return proc_pident_readdir(filp, ctx, \
2708 LSM##_attr_dir_stuff, \
2709 ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2710 } \
2711 \
2712 static const struct file_operations proc_##LSM##_attr_dir_ops = { \
2713 .read = generic_read_dir, \
2714 .iterate = proc_##LSM##_attr_dir_iterate, \
2715 .llseek = default_llseek, \
2716 }; \
2717 \
2718 static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
2719 struct dentry *dentry, unsigned int flags) \
2720 { \
2721 return proc_pident_lookup(dir, dentry, \
2722 LSM##_attr_dir_stuff, \
2723 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2724 } \
2725 \
2726 static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
2727 .lookup = proc_##LSM##_attr_dir_lookup, \
2728 .getattr = pid_getattr, \
2729 .setattr = proc_setattr, \
2730 }
2731
2732 #ifdef CONFIG_SECURITY_SMACK
2733 static const struct pid_entry smack_attr_dir_stuff[] = {
2734 ATTR("smack", "current", 0666),
2735 };
2736 LSM_DIR_OPS(smack);
2737 #endif
2738
2739 static const struct pid_entry attr_dir_stuff[] = {
2740 ATTR(NULL, "current", 0666),
2741 ATTR(NULL, "prev", 0444),
2742 ATTR(NULL, "exec", 0666),
2743 ATTR(NULL, "fscreate", 0666),
2744 ATTR(NULL, "keycreate", 0666),
2745 ATTR(NULL, "sockcreate", 0666),
2746 #ifdef CONFIG_SECURITY_SMACK
2747 DIR("smack", 0555,
2748 proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
2749 #endif
2750 };
2751
2752 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2753 {
2754 return proc_pident_readdir(file, ctx,
2755 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2756 }
2757
2758 static const struct file_operations proc_attr_dir_operations = {
2759 .read = generic_read_dir,
2760 .iterate_shared = proc_attr_dir_readdir,
2761 .llseek = generic_file_llseek,
2762 };
2763
2764 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2765 struct dentry *dentry, unsigned int flags)
2766 {
2767 return proc_pident_lookup(dir, dentry,
2768 attr_dir_stuff,
2769 attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
2770 }
2771
2772 static const struct inode_operations proc_attr_dir_inode_operations = {
2773 .lookup = proc_attr_dir_lookup,
2774 .getattr = pid_getattr,
2775 .setattr = proc_setattr,
2776 };
2777
2778 #endif
2779
2780 #ifdef CONFIG_ELF_CORE
2781 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2782 size_t count, loff_t *ppos)
2783 {
2784 struct task_struct *task = get_proc_task(file_inode(file));
2785 struct mm_struct *mm;
2786 char buffer[PROC_NUMBUF];
2787 size_t len;
2788 int ret;
2789
2790 if (!task)
2791 return -ESRCH;
2792
2793 ret = 0;
2794 mm = get_task_mm(task);
2795 if (mm) {
2796 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2797 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2798 MMF_DUMP_FILTER_SHIFT));
2799 mmput(mm);
2800 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2801 }
2802
2803 put_task_struct(task);
2804
2805 return ret;
2806 }
2807
2808 static ssize_t proc_coredump_filter_write(struct file *file,
2809 const char __user *buf,
2810 size_t count,
2811 loff_t *ppos)
2812 {
2813 struct task_struct *task;
2814 struct mm_struct *mm;
2815 unsigned int val;
2816 int ret;
2817 int i;
2818 unsigned long mask;
2819
2820 ret = kstrtouint_from_user(buf, count, 0, &val);
2821 if (ret < 0)
2822 return ret;
2823
2824 ret = -ESRCH;
2825 task = get_proc_task(file_inode(file));
2826 if (!task)
2827 goto out_no_task;
2828
2829 mm = get_task_mm(task);
2830 if (!mm)
2831 goto out_no_mm;
2832 ret = 0;
2833
2834 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2835 if (val & mask)
2836 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2837 else
2838 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2839 }
2840
2841 mmput(mm);
2842 out_no_mm:
2843 put_task_struct(task);
2844 out_no_task:
2845 if (ret < 0)
2846 return ret;
2847 return count;
2848 }
2849
2850 static const struct file_operations proc_coredump_filter_operations = {
2851 .read = proc_coredump_filter_read,
2852 .write = proc_coredump_filter_write,
2853 .llseek = generic_file_llseek,
2854 };
2855 #endif
2856
2857 #ifdef CONFIG_TASK_IO_ACCOUNTING
2858 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2859 {
2860 struct task_io_accounting acct = task->ioac;
2861 unsigned long flags;
2862 int result;
2863
2864 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2865 if (result)
2866 return result;
2867
2868 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2869 result = -EACCES;
2870 goto out_unlock;
2871 }
2872
2873 if (whole && lock_task_sighand(task, &flags)) {
2874 struct task_struct *t = task;
2875
2876 task_io_accounting_add(&acct, &task->signal->ioac);
2877 while_each_thread(task, t)
2878 task_io_accounting_add(&acct, &t->ioac);
2879
2880 unlock_task_sighand(task, &flags);
2881 }
2882 seq_printf(m,
2883 "rchar: %llu\n"
2884 "wchar: %llu\n"
2885 "syscr: %llu\n"
2886 "syscw: %llu\n"
2887 "read_bytes: %llu\n"
2888 "write_bytes: %llu\n"
2889 "cancelled_write_bytes: %llu\n",
2890 (unsigned long long)acct.rchar,
2891 (unsigned long long)acct.wchar,
2892 (unsigned long long)acct.syscr,
2893 (unsigned long long)acct.syscw,
2894 (unsigned long long)acct.read_bytes,
2895 (unsigned long long)acct.write_bytes,
2896 (unsigned long long)acct.cancelled_write_bytes);
2897 result = 0;
2898
2899 out_unlock:
2900 mutex_unlock(&task->signal->cred_guard_mutex);
2901 return result;
2902 }
2903
2904 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2905 struct pid *pid, struct task_struct *task)
2906 {
2907 return do_io_accounting(task, m, 0);
2908 }
2909
2910 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2911 struct pid *pid, struct task_struct *task)
2912 {
2913 return do_io_accounting(task, m, 1);
2914 }
2915 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2916
2917 #ifdef CONFIG_USER_NS
2918 static int proc_id_map_open(struct inode *inode, struct file *file,
2919 const struct seq_operations *seq_ops)
2920 {
2921 struct user_namespace *ns = NULL;
2922 struct task_struct *task;
2923 struct seq_file *seq;
2924 int ret = -EINVAL;
2925
2926 task = get_proc_task(inode);
2927 if (task) {
2928 rcu_read_lock();
2929 ns = get_user_ns(task_cred_xxx(task, user_ns));
2930 rcu_read_unlock();
2931 put_task_struct(task);
2932 }
2933 if (!ns)
2934 goto err;
2935
2936 ret = seq_open(file, seq_ops);
2937 if (ret)
2938 goto err_put_ns;
2939
2940 seq = file->private_data;
2941 seq->private = ns;
2942
2943 return 0;
2944 err_put_ns:
2945 put_user_ns(ns);
2946 err:
2947 return ret;
2948 }
2949
2950 static int proc_id_map_release(struct inode *inode, struct file *file)
2951 {
2952 struct seq_file *seq = file->private_data;
2953 struct user_namespace *ns = seq->private;
2954 put_user_ns(ns);
2955 return seq_release(inode, file);
2956 }
2957
2958 static int proc_uid_map_open(struct inode *inode, struct file *file)
2959 {
2960 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2961 }
2962
2963 static int proc_gid_map_open(struct inode *inode, struct file *file)
2964 {
2965 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2966 }
2967
2968 static int proc_projid_map_open(struct inode *inode, struct file *file)
2969 {
2970 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2971 }
2972
2973 static const struct file_operations proc_uid_map_operations = {
2974 .open = proc_uid_map_open,
2975 .write = proc_uid_map_write,
2976 .read = seq_read,
2977 .llseek = seq_lseek,
2978 .release = proc_id_map_release,
2979 };
2980
2981 static const struct file_operations proc_gid_map_operations = {
2982 .open = proc_gid_map_open,
2983 .write = proc_gid_map_write,
2984 .read = seq_read,
2985 .llseek = seq_lseek,
2986 .release = proc_id_map_release,
2987 };
2988
2989 static const struct file_operations proc_projid_map_operations = {
2990 .open = proc_projid_map_open,
2991 .write = proc_projid_map_write,
2992 .read = seq_read,
2993 .llseek = seq_lseek,
2994 .release = proc_id_map_release,
2995 };
2996
2997 static int proc_setgroups_open(struct inode *inode, struct file *file)
2998 {
2999 struct user_namespace *ns = NULL;
3000 struct task_struct *task;
3001 int ret;
3002
3003 ret = -ESRCH;
3004 task = get_proc_task(inode);
3005 if (task) {
3006 rcu_read_lock();
3007 ns = get_user_ns(task_cred_xxx(task, user_ns));
3008 rcu_read_unlock();
3009 put_task_struct(task);
3010 }
3011 if (!ns)
3012 goto err;
3013
3014 if (file->f_mode & FMODE_WRITE) {
3015 ret = -EACCES;
3016 if (!ns_capable(ns, CAP_SYS_ADMIN))
3017 goto err_put_ns;
3018 }
3019
3020 ret = single_open(file, &proc_setgroups_show, ns);
3021 if (ret)
3022 goto err_put_ns;
3023
3024 return 0;
3025 err_put_ns:
3026 put_user_ns(ns);
3027 err:
3028 return ret;
3029 }
3030
3031 static int proc_setgroups_release(struct inode *inode, struct file *file)
3032 {
3033 struct seq_file *seq = file->private_data;
3034 struct user_namespace *ns = seq->private;
3035 int ret = single_release(inode, file);
3036 put_user_ns(ns);
3037 return ret;
3038 }
3039
3040 static const struct file_operations proc_setgroups_operations = {
3041 .open = proc_setgroups_open,
3042 .write = proc_setgroups_write,
3043 .read = seq_read,
3044 .llseek = seq_lseek,
3045 .release = proc_setgroups_release,
3046 };
3047 #endif /* CONFIG_USER_NS */
3048
3049 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
3050 struct pid *pid, struct task_struct *task)
3051 {
3052 int err = lock_trace(task);
3053 if (!err) {
3054 seq_printf(m, "%08x\n", task->personality);
3055 unlock_trace(task);
3056 }
3057 return err;
3058 }
3059
3060 #ifdef CONFIG_LIVEPATCH
3061 static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
3062 struct pid *pid, struct task_struct *task)
3063 {
3064 seq_printf(m, "%d\n", task->patch_state);
3065 return 0;
3066 }
3067 #endif /* CONFIG_LIVEPATCH */
3068
3069 #ifdef CONFIG_STACKLEAK_METRICS
3070 static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
3071 struct pid *pid, struct task_struct *task)
3072 {
3073 unsigned long prev_depth = THREAD_SIZE -
3074 (task->prev_lowest_stack & (THREAD_SIZE - 1));
3075 unsigned long depth = THREAD_SIZE -
3076 (task->lowest_stack & (THREAD_SIZE - 1));
3077
3078 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
3079 prev_depth, depth);
3080 return 0;
3081 }
3082 #endif /* CONFIG_STACKLEAK_METRICS */
3083
3084 /*
3085 * Thread groups
3086 */
3087 static const struct file_operations proc_task_operations;
3088 static const struct inode_operations proc_task_inode_operations;
3089
3090 static const struct pid_entry tgid_base_stuff[] = {
3091 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3092 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3093 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3094 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3095 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3096 #ifdef CONFIG_NET
3097 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3098 #endif
3099 REG("environ", S_IRUSR, proc_environ_operations),
3100 REG("auxv", S_IRUSR, proc_auxv_operations),
3101 ONE("status", S_IRUGO, proc_pid_status),
3102 ONE("personality", S_IRUSR, proc_pid_personality),
3103 ONE("limits", S_IRUGO, proc_pid_limits),
3104 #ifdef CONFIG_SCHED_DEBUG
3105 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3106 #endif
3107 #ifdef CONFIG_SCHED_AUTOGROUP
3108 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3109 #endif
3110 #ifdef CONFIG_TIME_NS
3111 REG("timens_offsets", S_IRUGO|S_IWUSR, proc_timens_offsets_operations),
3112 #endif
3113 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3114 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3115 ONE("syscall", S_IRUSR, proc_pid_syscall),
3116 #endif
3117 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3118 ONE("stat", S_IRUGO, proc_tgid_stat),
3119 ONE("statm", S_IRUGO, proc_pid_statm),
3120 REG("maps", S_IRUGO, proc_pid_maps_operations),
3121 #ifdef CONFIG_NUMA
3122 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3123 #endif
3124 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3125 LNK("cwd", proc_cwd_link),
3126 LNK("root", proc_root_link),
3127 LNK("exe", proc_exe_link),
3128 REG("mounts", S_IRUGO, proc_mounts_operations),
3129 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3130 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3131 #ifdef CONFIG_PROC_PAGE_MONITOR
3132 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3133 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3134 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3135 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3136 #endif
3137 #ifdef CONFIG_SECURITY
3138 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3139 #endif
3140 #ifdef CONFIG_KALLSYMS
3141 ONE("wchan", S_IRUGO, proc_pid_wchan),
3142 #endif
3143 #ifdef CONFIG_STACKTRACE
3144 ONE("stack", S_IRUSR, proc_pid_stack),
3145 #endif
3146 #ifdef CONFIG_SCHED_INFO
3147 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3148 #endif
3149 #ifdef CONFIG_LATENCYTOP
3150 REG("latency", S_IRUGO, proc_lstats_operations),
3151 #endif
3152 #ifdef CONFIG_PROC_PID_CPUSET
3153 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3154 #endif
3155 #ifdef CONFIG_CGROUPS
3156 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3157 #endif
3158 #ifdef CONFIG_PROC_CPU_RESCTRL
3159 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3160 #endif
3161 ONE("oom_score", S_IRUGO, proc_oom_score),
3162 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3163 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3164 #ifdef CONFIG_AUDIT
3165 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3166 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3167 #endif
3168 #ifdef CONFIG_FAULT_INJECTION
3169 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3170 REG("fail-nth", 0644, proc_fail_nth_operations),
3171 #endif
3172 #ifdef CONFIG_ELF_CORE
3173 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3174 #endif
3175 #ifdef CONFIG_TASK_IO_ACCOUNTING
3176 ONE("io", S_IRUSR, proc_tgid_io_accounting),
3177 #endif
3178 #ifdef CONFIG_USER_NS
3179 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3180 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3181 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3182 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3183 #endif
3184 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3185 REG("timers", S_IRUGO, proc_timers_operations),
3186 #endif
3187 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3188 #ifdef CONFIG_LIVEPATCH
3189 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3190 #endif
3191 #ifdef CONFIG_STACKLEAK_METRICS
3192 ONE("stack_depth", S_IRUGO, proc_stack_depth),
3193 #endif
3194 #ifdef CONFIG_PROC_PID_ARCH_STATUS
3195 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3196 #endif
3197 };
3198
3199 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3200 {
3201 return proc_pident_readdir(file, ctx,
3202 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3203 }
3204
3205 static const struct file_operations proc_tgid_base_operations = {
3206 .read = generic_read_dir,
3207 .iterate_shared = proc_tgid_base_readdir,
3208 .llseek = generic_file_llseek,
3209 };
3210
3211 struct pid *tgid_pidfd_to_pid(const struct file *file)
3212 {
3213 if (file->f_op != &proc_tgid_base_operations)
3214 return ERR_PTR(-EBADF);
3215
3216 return proc_pid(file_inode(file));
3217 }
3218
3219 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3220 {
3221 return proc_pident_lookup(dir, dentry,
3222 tgid_base_stuff,
3223 tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
3224 }
3225
3226 static const struct inode_operations proc_tgid_base_inode_operations = {
3227 .lookup = proc_tgid_base_lookup,
3228 .getattr = pid_getattr,
3229 .setattr = proc_setattr,
3230 .permission = proc_pid_permission,
3231 };
3232
3233 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
3234 {
3235 struct dentry *dentry, *leader, *dir;
3236 char buf[10 + 1];
3237 struct qstr name;
3238
3239 name.name = buf;
3240 name.len = snprintf(buf, sizeof(buf), "%u", pid);
3241 /* no ->d_hash() rejects on procfs */
3242 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
3243 if (dentry) {
3244 d_invalidate(dentry);
3245 dput(dentry);
3246 }
3247
3248 if (pid == tgid)
3249 return;
3250
3251 name.name = buf;
3252 name.len = snprintf(buf, sizeof(buf), "%u", tgid);
3253 leader = d_hash_and_lookup(mnt->mnt_root, &name);
3254 if (!leader)
3255 goto out;
3256
3257 name.name = "task";
3258 name.len = strlen(name.name);
3259 dir = d_hash_and_lookup(leader, &name);
3260 if (!dir)
3261 goto out_put_leader;
3262
3263 name.name = buf;
3264 name.len = snprintf(buf, sizeof(buf), "%u", pid);
3265 dentry = d_hash_and_lookup(dir, &name);
3266 if (dentry) {
3267 d_invalidate(dentry);
3268 dput(dentry);
3269 }
3270
3271 dput(dir);
3272 out_put_leader:
3273 dput(leader);
3274 out:
3275 return;
3276 }
3277
3278 /**
3279 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3280 * @task: task that should be flushed.
3281 *
3282 * When flushing dentries from proc, one needs to flush them from global
3283 * proc (proc_mnt) and from all the namespaces' procs this task was seen
3284 * in. This call is supposed to do all of this job.
3285 *
3286 * Looks in the dcache for
3287 * /proc/@pid
3288 * /proc/@tgid/task/@pid
3289 * if either directory is present flushes it and all of it'ts children
3290 * from the dcache.
3291 *
3292 * It is safe and reasonable to cache /proc entries for a task until
3293 * that task exits. After that they just clog up the dcache with
3294 * useless entries, possibly causing useful dcache entries to be
3295 * flushed instead. This routine is proved to flush those useless
3296 * dcache entries at process exit time.
3297 *
3298 * NOTE: This routine is just an optimization so it does not guarantee
3299 * that no dcache entries will exist at process exit time it
3300 * just makes it very unlikely that any will persist.
3301 */
3302
3303 void proc_flush_task(struct task_struct *task)
3304 {
3305 int i;
3306 struct pid *pid, *tgid;
3307 struct upid *upid;
3308
3309 pid = task_pid(task);
3310 tgid = task_tgid(task);
3311
3312 for (i = 0; i <= pid->level; i++) {
3313 upid = &pid->numbers[i];
3314 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3315 tgid->numbers[i].nr);
3316 }
3317 }
3318
3319 static struct dentry *proc_pid_instantiate(struct dentry * dentry,
3320 struct task_struct *task, const void *ptr)
3321 {
3322 struct inode *inode;
3323
3324 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3325 if (!inode)
3326 return ERR_PTR(-ENOENT);
3327
3328 inode->i_op = &proc_tgid_base_inode_operations;
3329 inode->i_fop = &proc_tgid_base_operations;
3330 inode->i_flags|=S_IMMUTABLE;
3331
3332 set_nlink(inode, nlink_tgid);
3333 pid_update_inode(task, inode);
3334
3335 d_set_d_op(dentry, &pid_dentry_operations);
3336 return d_splice_alias(inode, dentry);
3337 }
3338
3339 struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
3340 {
3341 struct task_struct *task;
3342 unsigned tgid;
3343 struct pid_namespace *ns;
3344 struct dentry *result = ERR_PTR(-ENOENT);
3345
3346 tgid = name_to_int(&dentry->d_name);
3347 if (tgid == ~0U)
3348 goto out;
3349
3350 ns = dentry->d_sb->s_fs_info;
3351 rcu_read_lock();
3352 task = find_task_by_pid_ns(tgid, ns);
3353 if (task)
3354 get_task_struct(task);
3355 rcu_read_unlock();
3356 if (!task)
3357 goto out;
3358
3359 result = proc_pid_instantiate(dentry, task, NULL);
3360 put_task_struct(task);
3361 out:
3362 return result;
3363 }
3364
3365 /*
3366 * Find the first task with tgid >= tgid
3367 *
3368 */
3369 struct tgid_iter {
3370 unsigned int tgid;
3371 struct task_struct *task;
3372 };
3373 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3374 {
3375 struct pid *pid;
3376
3377 if (iter.task)
3378 put_task_struct(iter.task);
3379 rcu_read_lock();
3380 retry:
3381 iter.task = NULL;
3382 pid = find_ge_pid(iter.tgid, ns);
3383 if (pid) {
3384 iter.tgid = pid_nr_ns(pid, ns);
3385 iter.task = pid_task(pid, PIDTYPE_PID);
3386 /* What we to know is if the pid we have find is the
3387 * pid of a thread_group_leader. Testing for task
3388 * being a thread_group_leader is the obvious thing
3389 * todo but there is a window when it fails, due to
3390 * the pid transfer logic in de_thread.
3391 *
3392 * So we perform the straight forward test of seeing
3393 * if the pid we have found is the pid of a thread
3394 * group leader, and don't worry if the task we have
3395 * found doesn't happen to be a thread group leader.
3396 * As we don't care in the case of readdir.
3397 */
3398 if (!iter.task || !has_group_leader_pid(iter.task)) {
3399 iter.tgid += 1;
3400 goto retry;
3401 }
3402 get_task_struct(iter.task);
3403 }
3404 rcu_read_unlock();
3405 return iter;
3406 }
3407
3408 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3409
3410 /* for the /proc/ directory itself, after non-process stuff has been done */
3411 int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3412 {
3413 struct tgid_iter iter;
3414 struct pid_namespace *ns = proc_pid_ns(file_inode(file));
3415 loff_t pos = ctx->pos;
3416
3417 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3418 return 0;
3419
3420 if (pos == TGID_OFFSET - 2) {
3421 struct inode *inode = d_inode(ns->proc_self);
3422 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3423 return 0;
3424 ctx->pos = pos = pos + 1;
3425 }
3426 if (pos == TGID_OFFSET - 1) {
3427 struct inode *inode = d_inode(ns->proc_thread_self);
3428 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3429 return 0;
3430 ctx->pos = pos = pos + 1;
3431 }
3432 iter.tgid = pos - TGID_OFFSET;
3433 iter.task = NULL;
3434 for (iter = next_tgid(ns, iter);
3435 iter.task;
3436 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3437 char name[10 + 1];
3438 unsigned int len;
3439
3440 cond_resched();
3441 if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE))
3442 continue;
3443
3444 len = snprintf(name, sizeof(name), "%u", iter.tgid);
3445 ctx->pos = iter.tgid + TGID_OFFSET;
3446 if (!proc_fill_cache(file, ctx, name, len,
3447 proc_pid_instantiate, iter.task, NULL)) {
3448 put_task_struct(iter.task);
3449 return 0;
3450 }
3451 }
3452 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3453 return 0;
3454 }
3455
3456 /*
3457 * proc_tid_comm_permission is a special permission function exclusively
3458 * used for the node /proc/<pid>/task/<tid>/comm.
3459 * It bypasses generic permission checks in the case where a task of the same
3460 * task group attempts to access the node.
3461 * The rationale behind this is that glibc and bionic access this node for
3462 * cross thread naming (pthread_set/getname_np(!self)). However, if
3463 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3464 * which locks out the cross thread naming implementation.
3465 * This function makes sure that the node is always accessible for members of
3466 * same thread group.
3467 */
3468 static int proc_tid_comm_permission(struct inode *inode, int mask)
3469 {
3470 bool is_same_tgroup;
3471 struct task_struct *task;
3472
3473 task = get_proc_task(inode);
3474 if (!task)
3475 return -ESRCH;
3476 is_same_tgroup = same_thread_group(current, task);
3477 put_task_struct(task);
3478
3479 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3480 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3481 * read or written by the members of the corresponding
3482 * thread group.
3483 */
3484 return 0;
3485 }
3486
3487 return generic_permission(inode, mask);
3488 }
3489
3490 static const struct inode_operations proc_tid_comm_inode_operations = {
3491 .permission = proc_tid_comm_permission,
3492 };
3493
3494 /*
3495 * Tasks
3496 */
3497 static const struct pid_entry tid_base_stuff[] = {
3498 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3499 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3500 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3501 #ifdef CONFIG_NET
3502 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3503 #endif
3504 REG("environ", S_IRUSR, proc_environ_operations),
3505 REG("auxv", S_IRUSR, proc_auxv_operations),
3506 ONE("status", S_IRUGO, proc_pid_status),
3507 ONE("personality", S_IRUSR, proc_pid_personality),
3508 ONE("limits", S_IRUGO, proc_pid_limits),
3509 #ifdef CONFIG_SCHED_DEBUG
3510 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3511 #endif
3512 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3513 &proc_tid_comm_inode_operations,
3514 &proc_pid_set_comm_operations, {}),
3515 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3516 ONE("syscall", S_IRUSR, proc_pid_syscall),
3517 #endif
3518 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3519 ONE("stat", S_IRUGO, proc_tid_stat),
3520 ONE("statm", S_IRUGO, proc_pid_statm),
3521 REG("maps", S_IRUGO, proc_pid_maps_operations),
3522 #ifdef CONFIG_PROC_CHILDREN
3523 REG("children", S_IRUGO, proc_tid_children_operations),
3524 #endif
3525 #ifdef CONFIG_NUMA
3526 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3527 #endif
3528 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3529 LNK("cwd", proc_cwd_link),
3530 LNK("root", proc_root_link),
3531 LNK("exe", proc_exe_link),
3532 REG("mounts", S_IRUGO, proc_mounts_operations),
3533 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3534 #ifdef CONFIG_PROC_PAGE_MONITOR
3535 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3536 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3537 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3538 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3539 #endif
3540 #ifdef CONFIG_SECURITY
3541 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3542 #endif
3543 #ifdef CONFIG_KALLSYMS
3544 ONE("wchan", S_IRUGO, proc_pid_wchan),
3545 #endif
3546 #ifdef CONFIG_STACKTRACE
3547 ONE("stack", S_IRUSR, proc_pid_stack),
3548 #endif
3549 #ifdef CONFIG_SCHED_INFO
3550 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3551 #endif
3552 #ifdef CONFIG_LATENCYTOP
3553 REG("latency", S_IRUGO, proc_lstats_operations),
3554 #endif
3555 #ifdef CONFIG_PROC_PID_CPUSET
3556 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3557 #endif
3558 #ifdef CONFIG_CGROUPS
3559 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3560 #endif
3561 #ifdef CONFIG_PROC_CPU_RESCTRL
3562 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3563 #endif
3564 ONE("oom_score", S_IRUGO, proc_oom_score),
3565 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3566 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3567 #ifdef CONFIG_AUDIT
3568 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3569 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3570 #endif
3571 #ifdef CONFIG_FAULT_INJECTION
3572 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3573 REG("fail-nth", 0644, proc_fail_nth_operations),
3574 #endif
3575 #ifdef CONFIG_TASK_IO_ACCOUNTING
3576 ONE("io", S_IRUSR, proc_tid_io_accounting),
3577 #endif
3578 #ifdef CONFIG_USER_NS
3579 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3580 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3581 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3582 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3583 #endif
3584 #ifdef CONFIG_LIVEPATCH
3585 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3586 #endif
3587 #ifdef CONFIG_PROC_PID_ARCH_STATUS
3588 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3589 #endif
3590 };
3591
3592 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3593 {
3594 return proc_pident_readdir(file, ctx,
3595 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3596 }
3597
3598 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3599 {
3600 return proc_pident_lookup(dir, dentry,
3601 tid_base_stuff,
3602 tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
3603 }
3604
3605 static const struct file_operations proc_tid_base_operations = {
3606 .read = generic_read_dir,
3607 .iterate_shared = proc_tid_base_readdir,
3608 .llseek = generic_file_llseek,
3609 };
3610
3611 static const struct inode_operations proc_tid_base_inode_operations = {
3612 .lookup = proc_tid_base_lookup,
3613 .getattr = pid_getattr,
3614 .setattr = proc_setattr,
3615 };
3616
3617 static struct dentry *proc_task_instantiate(struct dentry *dentry,
3618 struct task_struct *task, const void *ptr)
3619 {
3620 struct inode *inode;
3621 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3622 if (!inode)
3623 return ERR_PTR(-ENOENT);
3624
3625 inode->i_op = &proc_tid_base_inode_operations;
3626 inode->i_fop = &proc_tid_base_operations;
3627 inode->i_flags |= S_IMMUTABLE;
3628
3629 set_nlink(inode, nlink_tid);
3630 pid_update_inode(task, inode);
3631
3632 d_set_d_op(dentry, &pid_dentry_operations);
3633 return d_splice_alias(inode, dentry);
3634 }
3635
3636 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3637 {
3638 struct task_struct *task;
3639 struct task_struct *leader = get_proc_task(dir);
3640 unsigned tid;
3641 struct pid_namespace *ns;
3642 struct dentry *result = ERR_PTR(-ENOENT);
3643
3644 if (!leader)
3645 goto out_no_task;
3646
3647 tid = name_to_int(&dentry->d_name);
3648 if (tid == ~0U)
3649 goto out;
3650
3651 ns = dentry->d_sb->s_fs_info;
3652 rcu_read_lock();
3653 task = find_task_by_pid_ns(tid, ns);
3654 if (task)
3655 get_task_struct(task);
3656 rcu_read_unlock();
3657 if (!task)
3658 goto out;
3659 if (!same_thread_group(leader, task))
3660 goto out_drop_task;
3661
3662 result = proc_task_instantiate(dentry, task, NULL);
3663 out_drop_task:
3664 put_task_struct(task);
3665 out:
3666 put_task_struct(leader);
3667 out_no_task:
3668 return result;
3669 }
3670
3671 /*
3672 * Find the first tid of a thread group to return to user space.
3673 *
3674 * Usually this is just the thread group leader, but if the users
3675 * buffer was too small or there was a seek into the middle of the
3676 * directory we have more work todo.
3677 *
3678 * In the case of a short read we start with find_task_by_pid.
3679 *
3680 * In the case of a seek we start with the leader and walk nr
3681 * threads past it.
3682 */
3683 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3684 struct pid_namespace *ns)
3685 {
3686 struct task_struct *pos, *task;
3687 unsigned long nr = f_pos;
3688
3689 if (nr != f_pos) /* 32bit overflow? */
3690 return NULL;
3691
3692 rcu_read_lock();
3693 task = pid_task(pid, PIDTYPE_PID);
3694 if (!task)
3695 goto fail;
3696
3697 /* Attempt to start with the tid of a thread */
3698 if (tid && nr) {
3699 pos = find_task_by_pid_ns(tid, ns);
3700 if (pos && same_thread_group(pos, task))
3701 goto found;
3702 }
3703
3704 /* If nr exceeds the number of threads there is nothing todo */
3705 if (nr >= get_nr_threads(task))
3706 goto fail;
3707
3708 /* If we haven't found our starting place yet start
3709 * with the leader and walk nr threads forward.
3710 */
3711 pos = task = task->group_leader;
3712 do {
3713 if (!nr--)
3714 goto found;
3715 } while_each_thread(task, pos);
3716 fail:
3717 pos = NULL;
3718 goto out;
3719 found:
3720 get_task_struct(pos);
3721 out:
3722 rcu_read_unlock();
3723 return pos;
3724 }
3725
3726 /*
3727 * Find the next thread in the thread list.
3728 * Return NULL if there is an error or no next thread.
3729 *
3730 * The reference to the input task_struct is released.
3731 */
3732 static struct task_struct *next_tid(struct task_struct *start)
3733 {
3734 struct task_struct *pos = NULL;
3735 rcu_read_lock();
3736 if (pid_alive(start)) {
3737 pos = next_thread(start);
3738 if (thread_group_leader(pos))
3739 pos = NULL;
3740 else
3741 get_task_struct(pos);
3742 }
3743 rcu_read_unlock();
3744 put_task_struct(start);
3745 return pos;
3746 }
3747
3748 /* for the /proc/TGID/task/ directories */
3749 static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3750 {
3751 struct inode *inode = file_inode(file);
3752 struct task_struct *task;
3753 struct pid_namespace *ns;
3754 int tid;
3755
3756 if (proc_inode_is_dead(inode))
3757 return -ENOENT;
3758
3759 if (!dir_emit_dots(file, ctx))
3760 return 0;
3761
3762 /* f_version caches the tgid value that the last readdir call couldn't
3763 * return. lseek aka telldir automagically resets f_version to 0.
3764 */
3765 ns = proc_pid_ns(inode);
3766 tid = (int)file->f_version;
3767 file->f_version = 0;
3768 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3769 task;
3770 task = next_tid(task), ctx->pos++) {
3771 char name[10 + 1];
3772 unsigned int len;
3773 tid = task_pid_nr_ns(task, ns);
3774 len = snprintf(name, sizeof(name), "%u", tid);
3775 if (!proc_fill_cache(file, ctx, name, len,
3776 proc_task_instantiate, task, NULL)) {
3777 /* returning this tgid failed, save it as the first
3778 * pid for the next readir call */
3779 file->f_version = (u64)tid;
3780 put_task_struct(task);
3781 break;
3782 }
3783 }
3784
3785 return 0;
3786 }
3787
3788 static int proc_task_getattr(const struct path *path, struct kstat *stat,
3789 u32 request_mask, unsigned int query_flags)
3790 {
3791 struct inode *inode = d_inode(path->dentry);
3792 struct task_struct *p = get_proc_task(inode);
3793 generic_fillattr(inode, stat);
3794
3795 if (p) {
3796 stat->nlink += get_nr_threads(p);
3797 put_task_struct(p);
3798 }
3799
3800 return 0;
3801 }
3802
3803 static const struct inode_operations proc_task_inode_operations = {
3804 .lookup = proc_task_lookup,
3805 .getattr = proc_task_getattr,
3806 .setattr = proc_setattr,
3807 .permission = proc_pid_permission,
3808 };
3809
3810 static const struct file_operations proc_task_operations = {
3811 .read = generic_read_dir,
3812 .iterate_shared = proc_task_readdir,
3813 .llseek = generic_file_llseek,
3814 };
3815
3816 void __init set_proc_pid_nlink(void)
3817 {
3818 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3819 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3820 }
Linux with added FPC-III support