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1/*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
48 */
49
50#include <asm/uaccess.h>
51
52#include <linux/errno.h>
53#include <linux/time.h>
54#include <linux/proc_fs.h>
55#include <linux/stat.h>
56#include <linux/task_io_accounting_ops.h>
57#include <linux/init.h>
58#include <linux/capability.h>
59#include <linux/file.h>
60#include <linux/fdtable.h>
61#include <linux/string.h>
62#include <linux/seq_file.h>
63#include <linux/namei.h>
64#include <linux/mnt_namespace.h>
65#include <linux/mm.h>
66#include <linux/swap.h>
67#include <linux/rcupdate.h>
68#include <linux/kallsyms.h>
69#include <linux/stacktrace.h>
70#include <linux/resource.h>
71#include <linux/module.h>
72#include <linux/mount.h>
73#include <linux/security.h>
74#include <linux/ptrace.h>
75#include <linux/tracehook.h>
76#include <linux/printk.h>
77#include <linux/cgroup.h>
78#include <linux/cpuset.h>
79#include <linux/audit.h>
80#include <linux/poll.h>
81#include <linux/nsproxy.h>
82#include <linux/oom.h>
83#include <linux/elf.h>
84#include <linux/pid_namespace.h>
85#include <linux/user_namespace.h>
86#include <linux/fs_struct.h>
87#include <linux/slab.h>
88#include <linux/flex_array.h>
89#include <linux/posix-timers.h>
90#ifdef CONFIG_HARDWALL
91#include <asm/hardwall.h>
92#endif
93#include <trace/events/oom.h>
94#include "internal.h"
95#include "fd.h"
96
97/* NOTE:
98 * Implementing inode permission operations in /proc is almost
99 * certainly an error. Permission checks need to happen during
100 * each system call not at open time. The reason is that most of
101 * what we wish to check for permissions in /proc varies at runtime.
102 *
103 * The classic example of a problem is opening file descriptors
104 * in /proc for a task before it execs a suid executable.
105 */
106
107struct pid_entry {
108 char *name;
109 int len;
110 umode_t mode;
111 const struct inode_operations *iop;
112 const struct file_operations *fop;
113 union proc_op op;
114};
115
116#define NOD(NAME, MODE, IOP, FOP, OP) { \
117 .name = (NAME), \
118 .len = sizeof(NAME) - 1, \
119 .mode = MODE, \
120 .iop = IOP, \
121 .fop = FOP, \
122 .op = OP, \
123}
124
125#define DIR(NAME, MODE, iops, fops) \
126 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
127#define LNK(NAME, get_link) \
128 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
129 &proc_pid_link_inode_operations, NULL, \
130 { .proc_get_link = get_link } )
131#define REG(NAME, MODE, fops) \
132 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
133#define INF(NAME, MODE, read) \
134 NOD(NAME, (S_IFREG|(MODE)), \
135 NULL, &proc_info_file_operations, \
136 { .proc_read = read } )
137#define ONE(NAME, MODE, show) \
138 NOD(NAME, (S_IFREG|(MODE)), \
139 NULL, &proc_single_file_operations, \
140 { .proc_show = show } )
141
142/*
143 * Count the number of hardlinks for the pid_entry table, excluding the .
144 * and .. links.
145 */
146static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
147 unsigned int n)
148{
149 unsigned int i;
150 unsigned int count;
151
152 count = 0;
153 for (i = 0; i < n; ++i) {
154 if (S_ISDIR(entries[i].mode))
155 ++count;
156 }
157
158 return count;
159}
160
161static int get_task_root(struct task_struct *task, struct path *root)
162{
163 int result = -ENOENT;
164
165 task_lock(task);
166 if (task->fs) {
167 get_fs_root(task->fs, root);
168 result = 0;
169 }
170 task_unlock(task);
171 return result;
172}
173
174static int proc_cwd_link(struct dentry *dentry, struct path *path)
175{
176 struct task_struct *task = get_proc_task(dentry->d_inode);
177 int result = -ENOENT;
178
179 if (task) {
180 task_lock(task);
181 if (task->fs) {
182 get_fs_pwd(task->fs, path);
183 result = 0;
184 }
185 task_unlock(task);
186 put_task_struct(task);
187 }
188 return result;
189}
190
191static int proc_root_link(struct dentry *dentry, struct path *path)
192{
193 struct task_struct *task = get_proc_task(dentry->d_inode);
194 int result = -ENOENT;
195
196 if (task) {
197 result = get_task_root(task, path);
198 put_task_struct(task);
199 }
200 return result;
201}
202
203static int proc_pid_cmdline(struct task_struct *task, char *buffer)
204{
205 return get_cmdline(task, buffer, PAGE_SIZE);
206}
207
208static int proc_pid_auxv(struct task_struct *task, char *buffer)
209{
210 struct mm_struct *mm = mm_access(task, PTRACE_MODE_READ);
211 int res = PTR_ERR(mm);
212 if (mm && !IS_ERR(mm)) {
213 unsigned int nwords = 0;
214 do {
215 nwords += 2;
216 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
217 res = nwords * sizeof(mm->saved_auxv[0]);
218 if (res > PAGE_SIZE)
219 res = PAGE_SIZE;
220 memcpy(buffer, mm->saved_auxv, res);
221 mmput(mm);
222 }
223 return res;
224}
225
226
227#ifdef CONFIG_KALLSYMS
228/*
229 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
230 * Returns the resolved symbol. If that fails, simply return the address.
231 */
232static int proc_pid_wchan(struct task_struct *task, char *buffer)
233{
234 unsigned long wchan;
235 char symname[KSYM_NAME_LEN];
236
237 wchan = get_wchan(task);
238
239 if (lookup_symbol_name(wchan, symname) < 0)
240 if (!ptrace_may_access(task, PTRACE_MODE_READ))
241 return 0;
242 else
243 return sprintf(buffer, "%lu", wchan);
244 else
245 return sprintf(buffer, "%s", symname);
246}
247#endif /* CONFIG_KALLSYMS */
248
249static int lock_trace(struct task_struct *task)
250{
251 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
252 if (err)
253 return err;
254 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
255 mutex_unlock(&task->signal->cred_guard_mutex);
256 return -EPERM;
257 }
258 return 0;
259}
260
261static void unlock_trace(struct task_struct *task)
262{
263 mutex_unlock(&task->signal->cred_guard_mutex);
264}
265
266#ifdef CONFIG_STACKTRACE
267
268#define MAX_STACK_TRACE_DEPTH 64
269
270static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
271 struct pid *pid, struct task_struct *task)
272{
273 struct stack_trace trace;
274 unsigned long *entries;
275 int err;
276 int i;
277
278 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
279 if (!entries)
280 return -ENOMEM;
281
282 trace.nr_entries = 0;
283 trace.max_entries = MAX_STACK_TRACE_DEPTH;
284 trace.entries = entries;
285 trace.skip = 0;
286
287 err = lock_trace(task);
288 if (!err) {
289 save_stack_trace_tsk(task, &trace);
290
291 for (i = 0; i < trace.nr_entries; i++) {
292 seq_printf(m, "[<%pK>] %pS\n",
293 (void *)entries[i], (void *)entries[i]);
294 }
295 unlock_trace(task);
296 }
297 kfree(entries);
298
299 return err;
300}
301#endif
302
303#ifdef CONFIG_SCHEDSTATS
304/*
305 * Provides /proc/PID/schedstat
306 */
307static int proc_pid_schedstat(struct task_struct *task, char *buffer)
308{
309 return sprintf(buffer, "%llu %llu %lu\n",
310 (unsigned long long)task->se.sum_exec_runtime,
311 (unsigned long long)task->sched_info.run_delay,
312 task->sched_info.pcount);
313}
314#endif
315
316#ifdef CONFIG_LATENCYTOP
317static int lstats_show_proc(struct seq_file *m, void *v)
318{
319 int i;
320 struct inode *inode = m->private;
321 struct task_struct *task = get_proc_task(inode);
322
323 if (!task)
324 return -ESRCH;
325 seq_puts(m, "Latency Top version : v0.1\n");
326 for (i = 0; i < 32; i++) {
327 struct latency_record *lr = &task->latency_record[i];
328 if (lr->backtrace[0]) {
329 int q;
330 seq_printf(m, "%i %li %li",
331 lr->count, lr->time, lr->max);
332 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
333 unsigned long bt = lr->backtrace[q];
334 if (!bt)
335 break;
336 if (bt == ULONG_MAX)
337 break;
338 seq_printf(m, " %ps", (void *)bt);
339 }
340 seq_putc(m, '\n');
341 }
342
343 }
344 put_task_struct(task);
345 return 0;
346}
347
348static int lstats_open(struct inode *inode, struct file *file)
349{
350 return single_open(file, lstats_show_proc, inode);
351}
352
353static ssize_t lstats_write(struct file *file, const char __user *buf,
354 size_t count, loff_t *offs)
355{
356 struct task_struct *task = get_proc_task(file_inode(file));
357
358 if (!task)
359 return -ESRCH;
360 clear_all_latency_tracing(task);
361 put_task_struct(task);
362
363 return count;
364}
365
366static const struct file_operations proc_lstats_operations = {
367 .open = lstats_open,
368 .read = seq_read,
369 .write = lstats_write,
370 .llseek = seq_lseek,
371 .release = single_release,
372};
373
374#endif
375
376#ifdef CONFIG_CGROUPS
377static int cgroup_open(struct inode *inode, struct file *file)
378{
379 struct pid *pid = PROC_I(inode)->pid;
380 return single_open(file, proc_cgroup_show, pid);
381}
382
383static const struct file_operations proc_cgroup_operations = {
384 .open = cgroup_open,
385 .read = seq_read,
386 .llseek = seq_lseek,
387 .release = single_release,
388};
389#endif
390
391#ifdef CONFIG_PROC_PID_CPUSET
392
393static int cpuset_open(struct inode *inode, struct file *file)
394{
395 struct pid *pid = PROC_I(inode)->pid;
396 return single_open(file, proc_cpuset_show, pid);
397}
398
399static const struct file_operations proc_cpuset_operations = {
400 .open = cpuset_open,
401 .read = seq_read,
402 .llseek = seq_lseek,
403 .release = single_release,
404};
405#endif
406
407static int proc_oom_score(struct task_struct *task, char *buffer)
408{
409 unsigned long totalpages = totalram_pages + total_swap_pages;
410 unsigned long points = 0;
411
412 read_lock(&tasklist_lock);
413 if (pid_alive(task))
414 points = oom_badness(task, NULL, NULL, totalpages) *
415 1000 / totalpages;
416 read_unlock(&tasklist_lock);
417 return sprintf(buffer, "%lu\n", points);
418}
419
420struct limit_names {
421 char *name;
422 char *unit;
423};
424
425static const struct limit_names lnames[RLIM_NLIMITS] = {
426 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
427 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
428 [RLIMIT_DATA] = {"Max data size", "bytes"},
429 [RLIMIT_STACK] = {"Max stack size", "bytes"},
430 [RLIMIT_CORE] = {"Max core file size", "bytes"},
431 [RLIMIT_RSS] = {"Max resident set", "bytes"},
432 [RLIMIT_NPROC] = {"Max processes", "processes"},
433 [RLIMIT_NOFILE] = {"Max open files", "files"},
434 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
435 [RLIMIT_AS] = {"Max address space", "bytes"},
436 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
437 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
438 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
439 [RLIMIT_NICE] = {"Max nice priority", NULL},
440 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
441 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
442};
443
444/* Display limits for a process */
445static int proc_pid_limits(struct task_struct *task, char *buffer)
446{
447 unsigned int i;
448 int count = 0;
449 unsigned long flags;
450 char *bufptr = buffer;
451
452 struct rlimit rlim[RLIM_NLIMITS];
453
454 if (!lock_task_sighand(task, &flags))
455 return 0;
456 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
457 unlock_task_sighand(task, &flags);
458
459 /*
460 * print the file header
461 */
462 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
463 "Limit", "Soft Limit", "Hard Limit", "Units");
464
465 for (i = 0; i < RLIM_NLIMITS; i++) {
466 if (rlim[i].rlim_cur == RLIM_INFINITY)
467 count += sprintf(&bufptr[count], "%-25s %-20s ",
468 lnames[i].name, "unlimited");
469 else
470 count += sprintf(&bufptr[count], "%-25s %-20lu ",
471 lnames[i].name, rlim[i].rlim_cur);
472
473 if (rlim[i].rlim_max == RLIM_INFINITY)
474 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
475 else
476 count += sprintf(&bufptr[count], "%-20lu ",
477 rlim[i].rlim_max);
478
479 if (lnames[i].unit)
480 count += sprintf(&bufptr[count], "%-10s\n",
481 lnames[i].unit);
482 else
483 count += sprintf(&bufptr[count], "\n");
484 }
485
486 return count;
487}
488
489#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
490static int proc_pid_syscall(struct task_struct *task, char *buffer)
491{
492 long nr;
493 unsigned long args[6], sp, pc;
494 int res = lock_trace(task);
495 if (res)
496 return res;
497
498 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
499 res = sprintf(buffer, "running\n");
500 else if (nr < 0)
501 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
502 else
503 res = sprintf(buffer,
504 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
505 nr,
506 args[0], args[1], args[2], args[3], args[4], args[5],
507 sp, pc);
508 unlock_trace(task);
509 return res;
510}
511#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
512
513/************************************************************************/
514/* Here the fs part begins */
515/************************************************************************/
516
517/* permission checks */
518static int proc_fd_access_allowed(struct inode *inode)
519{
520 struct task_struct *task;
521 int allowed = 0;
522 /* Allow access to a task's file descriptors if it is us or we
523 * may use ptrace attach to the process and find out that
524 * information.
525 */
526 task = get_proc_task(inode);
527 if (task) {
528 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
529 put_task_struct(task);
530 }
531 return allowed;
532}
533
534int proc_setattr(struct dentry *dentry, struct iattr *attr)
535{
536 int error;
537 struct inode *inode = dentry->d_inode;
538
539 if (attr->ia_valid & ATTR_MODE)
540 return -EPERM;
541
542 error = inode_change_ok(inode, attr);
543 if (error)
544 return error;
545
546 setattr_copy(inode, attr);
547 mark_inode_dirty(inode);
548 return 0;
549}
550
551/*
552 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
553 * or euid/egid (for hide_pid_min=2)?
554 */
555static bool has_pid_permissions(struct pid_namespace *pid,
556 struct task_struct *task,
557 int hide_pid_min)
558{
559 if (pid->hide_pid < hide_pid_min)
560 return true;
561 if (in_group_p(pid->pid_gid))
562 return true;
563 return ptrace_may_access(task, PTRACE_MODE_READ);
564}
565
566
567static int proc_pid_permission(struct inode *inode, int mask)
568{
569 struct pid_namespace *pid = inode->i_sb->s_fs_info;
570 struct task_struct *task;
571 bool has_perms;
572
573 task = get_proc_task(inode);
574 if (!task)
575 return -ESRCH;
576 has_perms = has_pid_permissions(pid, task, 1);
577 put_task_struct(task);
578
579 if (!has_perms) {
580 if (pid->hide_pid == 2) {
581 /*
582 * Let's make getdents(), stat(), and open()
583 * consistent with each other. If a process
584 * may not stat() a file, it shouldn't be seen
585 * in procfs at all.
586 */
587 return -ENOENT;
588 }
589
590 return -EPERM;
591 }
592 return generic_permission(inode, mask);
593}
594
595
596
597static const struct inode_operations proc_def_inode_operations = {
598 .setattr = proc_setattr,
599};
600
601#define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
602
603static ssize_t proc_info_read(struct file * file, char __user * buf,
604 size_t count, loff_t *ppos)
605{
606 struct inode * inode = file_inode(file);
607 unsigned long page;
608 ssize_t length;
609 struct task_struct *task = get_proc_task(inode);
610
611 length = -ESRCH;
612 if (!task)
613 goto out_no_task;
614
615 if (count > PROC_BLOCK_SIZE)
616 count = PROC_BLOCK_SIZE;
617
618 length = -ENOMEM;
619 if (!(page = __get_free_page(GFP_TEMPORARY)))
620 goto out;
621
622 length = PROC_I(inode)->op.proc_read(task, (char*)page);
623
624 if (length >= 0)
625 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
626 free_page(page);
627out:
628 put_task_struct(task);
629out_no_task:
630 return length;
631}
632
633static const struct file_operations proc_info_file_operations = {
634 .read = proc_info_read,
635 .llseek = generic_file_llseek,
636};
637
638static int proc_single_show(struct seq_file *m, void *v)
639{
640 struct inode *inode = m->private;
641 struct pid_namespace *ns;
642 struct pid *pid;
643 struct task_struct *task;
644 int ret;
645
646 ns = inode->i_sb->s_fs_info;
647 pid = proc_pid(inode);
648 task = get_pid_task(pid, PIDTYPE_PID);
649 if (!task)
650 return -ESRCH;
651
652 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
653
654 put_task_struct(task);
655 return ret;
656}
657
658static int proc_single_open(struct inode *inode, struct file *filp)
659{
660 return single_open(filp, proc_single_show, inode);
661}
662
663static const struct file_operations proc_single_file_operations = {
664 .open = proc_single_open,
665 .read = seq_read,
666 .llseek = seq_lseek,
667 .release = single_release,
668};
669
670static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
671{
672 struct task_struct *task = get_proc_task(file_inode(file));
673 struct mm_struct *mm;
674
675 if (!task)
676 return -ESRCH;
677
678 mm = mm_access(task, mode);
679 put_task_struct(task);
680
681 if (IS_ERR(mm))
682 return PTR_ERR(mm);
683
684 if (mm) {
685 /* ensure this mm_struct can't be freed */
686 atomic_inc(&mm->mm_count);
687 /* but do not pin its memory */
688 mmput(mm);
689 }
690
691 file->private_data = mm;
692
693 return 0;
694}
695
696static int mem_open(struct inode *inode, struct file *file)
697{
698 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
699
700 /* OK to pass negative loff_t, we can catch out-of-range */
701 file->f_mode |= FMODE_UNSIGNED_OFFSET;
702
703 return ret;
704}
705
706static ssize_t mem_rw(struct file *file, char __user *buf,
707 size_t count, loff_t *ppos, int write)
708{
709 struct mm_struct *mm = file->private_data;
710 unsigned long addr = *ppos;
711 ssize_t copied;
712 char *page;
713
714 if (!mm)
715 return 0;
716
717 page = (char *)__get_free_page(GFP_TEMPORARY);
718 if (!page)
719 return -ENOMEM;
720
721 copied = 0;
722 if (!atomic_inc_not_zero(&mm->mm_users))
723 goto free;
724
725 while (count > 0) {
726 int this_len = min_t(int, count, PAGE_SIZE);
727
728 if (write && copy_from_user(page, buf, this_len)) {
729 copied = -EFAULT;
730 break;
731 }
732
733 this_len = access_remote_vm(mm, addr, page, this_len, write);
734 if (!this_len) {
735 if (!copied)
736 copied = -EIO;
737 break;
738 }
739
740 if (!write && copy_to_user(buf, page, this_len)) {
741 copied = -EFAULT;
742 break;
743 }
744
745 buf += this_len;
746 addr += this_len;
747 copied += this_len;
748 count -= this_len;
749 }
750 *ppos = addr;
751
752 mmput(mm);
753free:
754 free_page((unsigned long) page);
755 return copied;
756}
757
758static ssize_t mem_read(struct file *file, char __user *buf,
759 size_t count, loff_t *ppos)
760{
761 return mem_rw(file, buf, count, ppos, 0);
762}
763
764static ssize_t mem_write(struct file *file, const char __user *buf,
765 size_t count, loff_t *ppos)
766{
767 return mem_rw(file, (char __user*)buf, count, ppos, 1);
768}
769
770loff_t mem_lseek(struct file *file, loff_t offset, int orig)
771{
772 switch (orig) {
773 case 0:
774 file->f_pos = offset;
775 break;
776 case 1:
777 file->f_pos += offset;
778 break;
779 default:
780 return -EINVAL;
781 }
782 force_successful_syscall_return();
783 return file->f_pos;
784}
785
786static int mem_release(struct inode *inode, struct file *file)
787{
788 struct mm_struct *mm = file->private_data;
789 if (mm)
790 mmdrop(mm);
791 return 0;
792}
793
794static const struct file_operations proc_mem_operations = {
795 .llseek = mem_lseek,
796 .read = mem_read,
797 .write = mem_write,
798 .open = mem_open,
799 .release = mem_release,
800};
801
802static int environ_open(struct inode *inode, struct file *file)
803{
804 return __mem_open(inode, file, PTRACE_MODE_READ);
805}
806
807static ssize_t environ_read(struct file *file, char __user *buf,
808 size_t count, loff_t *ppos)
809{
810 char *page;
811 unsigned long src = *ppos;
812 int ret = 0;
813 struct mm_struct *mm = file->private_data;
814
815 if (!mm)
816 return 0;
817
818 page = (char *)__get_free_page(GFP_TEMPORARY);
819 if (!page)
820 return -ENOMEM;
821
822 ret = 0;
823 if (!atomic_inc_not_zero(&mm->mm_users))
824 goto free;
825 while (count > 0) {
826 size_t this_len, max_len;
827 int retval;
828
829 if (src >= (mm->env_end - mm->env_start))
830 break;
831
832 this_len = mm->env_end - (mm->env_start + src);
833
834 max_len = min_t(size_t, PAGE_SIZE, count);
835 this_len = min(max_len, this_len);
836
837 retval = access_remote_vm(mm, (mm->env_start + src),
838 page, this_len, 0);
839
840 if (retval <= 0) {
841 ret = retval;
842 break;
843 }
844
845 if (copy_to_user(buf, page, retval)) {
846 ret = -EFAULT;
847 break;
848 }
849
850 ret += retval;
851 src += retval;
852 buf += retval;
853 count -= retval;
854 }
855 *ppos = src;
856 mmput(mm);
857
858free:
859 free_page((unsigned long) page);
860 return ret;
861}
862
863static const struct file_operations proc_environ_operations = {
864 .open = environ_open,
865 .read = environ_read,
866 .llseek = generic_file_llseek,
867 .release = mem_release,
868};
869
870static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
871 loff_t *ppos)
872{
873 struct task_struct *task = get_proc_task(file_inode(file));
874 char buffer[PROC_NUMBUF];
875 int oom_adj = OOM_ADJUST_MIN;
876 size_t len;
877 unsigned long flags;
878
879 if (!task)
880 return -ESRCH;
881 if (lock_task_sighand(task, &flags)) {
882 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
883 oom_adj = OOM_ADJUST_MAX;
884 else
885 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
886 OOM_SCORE_ADJ_MAX;
887 unlock_task_sighand(task, &flags);
888 }
889 put_task_struct(task);
890 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
891 return simple_read_from_buffer(buf, count, ppos, buffer, len);
892}
893
894static ssize_t oom_adj_write(struct file *file, const char __user *buf,
895 size_t count, loff_t *ppos)
896{
897 struct task_struct *task;
898 char buffer[PROC_NUMBUF];
899 int oom_adj;
900 unsigned long flags;
901 int err;
902
903 memset(buffer, 0, sizeof(buffer));
904 if (count > sizeof(buffer) - 1)
905 count = sizeof(buffer) - 1;
906 if (copy_from_user(buffer, buf, count)) {
907 err = -EFAULT;
908 goto out;
909 }
910
911 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
912 if (err)
913 goto out;
914 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
915 oom_adj != OOM_DISABLE) {
916 err = -EINVAL;
917 goto out;
918 }
919
920 task = get_proc_task(file_inode(file));
921 if (!task) {
922 err = -ESRCH;
923 goto out;
924 }
925
926 task_lock(task);
927 if (!task->mm) {
928 err = -EINVAL;
929 goto err_task_lock;
930 }
931
932 if (!lock_task_sighand(task, &flags)) {
933 err = -ESRCH;
934 goto err_task_lock;
935 }
936
937 /*
938 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
939 * value is always attainable.
940 */
941 if (oom_adj == OOM_ADJUST_MAX)
942 oom_adj = OOM_SCORE_ADJ_MAX;
943 else
944 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
945
946 if (oom_adj < task->signal->oom_score_adj &&
947 !capable(CAP_SYS_RESOURCE)) {
948 err = -EACCES;
949 goto err_sighand;
950 }
951
952 /*
953 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
954 * /proc/pid/oom_score_adj instead.
955 */
956 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
957 current->comm, task_pid_nr(current), task_pid_nr(task),
958 task_pid_nr(task));
959
960 task->signal->oom_score_adj = oom_adj;
961 trace_oom_score_adj_update(task);
962err_sighand:
963 unlock_task_sighand(task, &flags);
964err_task_lock:
965 task_unlock(task);
966 put_task_struct(task);
967out:
968 return err < 0 ? err : count;
969}
970
971static const struct file_operations proc_oom_adj_operations = {
972 .read = oom_adj_read,
973 .write = oom_adj_write,
974 .llseek = generic_file_llseek,
975};
976
977static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
978 size_t count, loff_t *ppos)
979{
980 struct task_struct *task = get_proc_task(file_inode(file));
981 char buffer[PROC_NUMBUF];
982 short oom_score_adj = OOM_SCORE_ADJ_MIN;
983 unsigned long flags;
984 size_t len;
985
986 if (!task)
987 return -ESRCH;
988 if (lock_task_sighand(task, &flags)) {
989 oom_score_adj = task->signal->oom_score_adj;
990 unlock_task_sighand(task, &flags);
991 }
992 put_task_struct(task);
993 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
994 return simple_read_from_buffer(buf, count, ppos, buffer, len);
995}
996
997static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
998 size_t count, loff_t *ppos)
999{
1000 struct task_struct *task;
1001 char buffer[PROC_NUMBUF];
1002 unsigned long flags;
1003 int oom_score_adj;
1004 int err;
1005
1006 memset(buffer, 0, sizeof(buffer));
1007 if (count > sizeof(buffer) - 1)
1008 count = sizeof(buffer) - 1;
1009 if (copy_from_user(buffer, buf, count)) {
1010 err = -EFAULT;
1011 goto out;
1012 }
1013
1014 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1015 if (err)
1016 goto out;
1017 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1018 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1019 err = -EINVAL;
1020 goto out;
1021 }
1022
1023 task = get_proc_task(file_inode(file));
1024 if (!task) {
1025 err = -ESRCH;
1026 goto out;
1027 }
1028
1029 task_lock(task);
1030 if (!task->mm) {
1031 err = -EINVAL;
1032 goto err_task_lock;
1033 }
1034
1035 if (!lock_task_sighand(task, &flags)) {
1036 err = -ESRCH;
1037 goto err_task_lock;
1038 }
1039
1040 if ((short)oom_score_adj < task->signal->oom_score_adj_min &&
1041 !capable(CAP_SYS_RESOURCE)) {
1042 err = -EACCES;
1043 goto err_sighand;
1044 }
1045
1046 task->signal->oom_score_adj = (short)oom_score_adj;
1047 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1048 task->signal->oom_score_adj_min = (short)oom_score_adj;
1049 trace_oom_score_adj_update(task);
1050
1051err_sighand:
1052 unlock_task_sighand(task, &flags);
1053err_task_lock:
1054 task_unlock(task);
1055 put_task_struct(task);
1056out:
1057 return err < 0 ? err : count;
1058}
1059
1060static const struct file_operations proc_oom_score_adj_operations = {
1061 .read = oom_score_adj_read,
1062 .write = oom_score_adj_write,
1063 .llseek = default_llseek,
1064};
1065
1066#ifdef CONFIG_AUDITSYSCALL
1067#define TMPBUFLEN 21
1068static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1069 size_t count, loff_t *ppos)
1070{
1071 struct inode * inode = file_inode(file);
1072 struct task_struct *task = get_proc_task(inode);
1073 ssize_t length;
1074 char tmpbuf[TMPBUFLEN];
1075
1076 if (!task)
1077 return -ESRCH;
1078 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1079 from_kuid(file->f_cred->user_ns,
1080 audit_get_loginuid(task)));
1081 put_task_struct(task);
1082 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1083}
1084
1085static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1086 size_t count, loff_t *ppos)
1087{
1088 struct inode * inode = file_inode(file);
1089 char *page, *tmp;
1090 ssize_t length;
1091 uid_t loginuid;
1092 kuid_t kloginuid;
1093
1094 rcu_read_lock();
1095 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1096 rcu_read_unlock();
1097 return -EPERM;
1098 }
1099 rcu_read_unlock();
1100
1101 if (count >= PAGE_SIZE)
1102 count = PAGE_SIZE - 1;
1103
1104 if (*ppos != 0) {
1105 /* No partial writes. */
1106 return -EINVAL;
1107 }
1108 page = (char*)__get_free_page(GFP_TEMPORARY);
1109 if (!page)
1110 return -ENOMEM;
1111 length = -EFAULT;
1112 if (copy_from_user(page, buf, count))
1113 goto out_free_page;
1114
1115 page[count] = '\0';
1116 loginuid = simple_strtoul(page, &tmp, 10);
1117 if (tmp == page) {
1118 length = -EINVAL;
1119 goto out_free_page;
1120
1121 }
1122
1123 /* is userspace tring to explicitly UNSET the loginuid? */
1124 if (loginuid == AUDIT_UID_UNSET) {
1125 kloginuid = INVALID_UID;
1126 } else {
1127 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1128 if (!uid_valid(kloginuid)) {
1129 length = -EINVAL;
1130 goto out_free_page;
1131 }
1132 }
1133
1134 length = audit_set_loginuid(kloginuid);
1135 if (likely(length == 0))
1136 length = count;
1137
1138out_free_page:
1139 free_page((unsigned long) page);
1140 return length;
1141}
1142
1143static const struct file_operations proc_loginuid_operations = {
1144 .read = proc_loginuid_read,
1145 .write = proc_loginuid_write,
1146 .llseek = generic_file_llseek,
1147};
1148
1149static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1150 size_t count, loff_t *ppos)
1151{
1152 struct inode * inode = file_inode(file);
1153 struct task_struct *task = get_proc_task(inode);
1154 ssize_t length;
1155 char tmpbuf[TMPBUFLEN];
1156
1157 if (!task)
1158 return -ESRCH;
1159 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1160 audit_get_sessionid(task));
1161 put_task_struct(task);
1162 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1163}
1164
1165static const struct file_operations proc_sessionid_operations = {
1166 .read = proc_sessionid_read,
1167 .llseek = generic_file_llseek,
1168};
1169#endif
1170
1171#ifdef CONFIG_FAULT_INJECTION
1172static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1173 size_t count, loff_t *ppos)
1174{
1175 struct task_struct *task = get_proc_task(file_inode(file));
1176 char buffer[PROC_NUMBUF];
1177 size_t len;
1178 int make_it_fail;
1179
1180 if (!task)
1181 return -ESRCH;
1182 make_it_fail = task->make_it_fail;
1183 put_task_struct(task);
1184
1185 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1186
1187 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1188}
1189
1190static ssize_t proc_fault_inject_write(struct file * file,
1191 const char __user * buf, size_t count, loff_t *ppos)
1192{
1193 struct task_struct *task;
1194 char buffer[PROC_NUMBUF], *end;
1195 int make_it_fail;
1196
1197 if (!capable(CAP_SYS_RESOURCE))
1198 return -EPERM;
1199 memset(buffer, 0, sizeof(buffer));
1200 if (count > sizeof(buffer) - 1)
1201 count = sizeof(buffer) - 1;
1202 if (copy_from_user(buffer, buf, count))
1203 return -EFAULT;
1204 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1205 if (*end)
1206 return -EINVAL;
1207 if (make_it_fail < 0 || make_it_fail > 1)
1208 return -EINVAL;
1209
1210 task = get_proc_task(file_inode(file));
1211 if (!task)
1212 return -ESRCH;
1213 task->make_it_fail = make_it_fail;
1214 put_task_struct(task);
1215
1216 return count;
1217}
1218
1219static const struct file_operations proc_fault_inject_operations = {
1220 .read = proc_fault_inject_read,
1221 .write = proc_fault_inject_write,
1222 .llseek = generic_file_llseek,
1223};
1224#endif
1225
1226
1227#ifdef CONFIG_SCHED_DEBUG
1228/*
1229 * Print out various scheduling related per-task fields:
1230 */
1231static int sched_show(struct seq_file *m, void *v)
1232{
1233 struct inode *inode = m->private;
1234 struct task_struct *p;
1235
1236 p = get_proc_task(inode);
1237 if (!p)
1238 return -ESRCH;
1239 proc_sched_show_task(p, m);
1240
1241 put_task_struct(p);
1242
1243 return 0;
1244}
1245
1246static ssize_t
1247sched_write(struct file *file, const char __user *buf,
1248 size_t count, loff_t *offset)
1249{
1250 struct inode *inode = file_inode(file);
1251 struct task_struct *p;
1252
1253 p = get_proc_task(inode);
1254 if (!p)
1255 return -ESRCH;
1256 proc_sched_set_task(p);
1257
1258 put_task_struct(p);
1259
1260 return count;
1261}
1262
1263static int sched_open(struct inode *inode, struct file *filp)
1264{
1265 return single_open(filp, sched_show, inode);
1266}
1267
1268static const struct file_operations proc_pid_sched_operations = {
1269 .open = sched_open,
1270 .read = seq_read,
1271 .write = sched_write,
1272 .llseek = seq_lseek,
1273 .release = single_release,
1274};
1275
1276#endif
1277
1278#ifdef CONFIG_SCHED_AUTOGROUP
1279/*
1280 * Print out autogroup related information:
1281 */
1282static int sched_autogroup_show(struct seq_file *m, void *v)
1283{
1284 struct inode *inode = m->private;
1285 struct task_struct *p;
1286
1287 p = get_proc_task(inode);
1288 if (!p)
1289 return -ESRCH;
1290 proc_sched_autogroup_show_task(p, m);
1291
1292 put_task_struct(p);
1293
1294 return 0;
1295}
1296
1297static ssize_t
1298sched_autogroup_write(struct file *file, const char __user *buf,
1299 size_t count, loff_t *offset)
1300{
1301 struct inode *inode = file_inode(file);
1302 struct task_struct *p;
1303 char buffer[PROC_NUMBUF];
1304 int nice;
1305 int err;
1306
1307 memset(buffer, 0, sizeof(buffer));
1308 if (count > sizeof(buffer) - 1)
1309 count = sizeof(buffer) - 1;
1310 if (copy_from_user(buffer, buf, count))
1311 return -EFAULT;
1312
1313 err = kstrtoint(strstrip(buffer), 0, &nice);
1314 if (err < 0)
1315 return err;
1316
1317 p = get_proc_task(inode);
1318 if (!p)
1319 return -ESRCH;
1320
1321 err = proc_sched_autogroup_set_nice(p, nice);
1322 if (err)
1323 count = err;
1324
1325 put_task_struct(p);
1326
1327 return count;
1328}
1329
1330static int sched_autogroup_open(struct inode *inode, struct file *filp)
1331{
1332 int ret;
1333
1334 ret = single_open(filp, sched_autogroup_show, NULL);
1335 if (!ret) {
1336 struct seq_file *m = filp->private_data;
1337
1338 m->private = inode;
1339 }
1340 return ret;
1341}
1342
1343static const struct file_operations proc_pid_sched_autogroup_operations = {
1344 .open = sched_autogroup_open,
1345 .read = seq_read,
1346 .write = sched_autogroup_write,
1347 .llseek = seq_lseek,
1348 .release = single_release,
1349};
1350
1351#endif /* CONFIG_SCHED_AUTOGROUP */
1352
1353static ssize_t comm_write(struct file *file, const char __user *buf,
1354 size_t count, loff_t *offset)
1355{
1356 struct inode *inode = file_inode(file);
1357 struct task_struct *p;
1358 char buffer[TASK_COMM_LEN];
1359 const size_t maxlen = sizeof(buffer) - 1;
1360
1361 memset(buffer, 0, sizeof(buffer));
1362 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1363 return -EFAULT;
1364
1365 p = get_proc_task(inode);
1366 if (!p)
1367 return -ESRCH;
1368
1369 if (same_thread_group(current, p))
1370 set_task_comm(p, buffer);
1371 else
1372 count = -EINVAL;
1373
1374 put_task_struct(p);
1375
1376 return count;
1377}
1378
1379static int comm_show(struct seq_file *m, void *v)
1380{
1381 struct inode *inode = m->private;
1382 struct task_struct *p;
1383
1384 p = get_proc_task(inode);
1385 if (!p)
1386 return -ESRCH;
1387
1388 task_lock(p);
1389 seq_printf(m, "%s\n", p->comm);
1390 task_unlock(p);
1391
1392 put_task_struct(p);
1393
1394 return 0;
1395}
1396
1397static int comm_open(struct inode *inode, struct file *filp)
1398{
1399 return single_open(filp, comm_show, inode);
1400}
1401
1402static const struct file_operations proc_pid_set_comm_operations = {
1403 .open = comm_open,
1404 .read = seq_read,
1405 .write = comm_write,
1406 .llseek = seq_lseek,
1407 .release = single_release,
1408};
1409
1410static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1411{
1412 struct task_struct *task;
1413 struct mm_struct *mm;
1414 struct file *exe_file;
1415
1416 task = get_proc_task(dentry->d_inode);
1417 if (!task)
1418 return -ENOENT;
1419 mm = get_task_mm(task);
1420 put_task_struct(task);
1421 if (!mm)
1422 return -ENOENT;
1423 exe_file = get_mm_exe_file(mm);
1424 mmput(mm);
1425 if (exe_file) {
1426 *exe_path = exe_file->f_path;
1427 path_get(&exe_file->f_path);
1428 fput(exe_file);
1429 return 0;
1430 } else
1431 return -ENOENT;
1432}
1433
1434static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1435{
1436 struct inode *inode = dentry->d_inode;
1437 struct path path;
1438 int error = -EACCES;
1439
1440 /* Are we allowed to snoop on the tasks file descriptors? */
1441 if (!proc_fd_access_allowed(inode))
1442 goto out;
1443
1444 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1445 if (error)
1446 goto out;
1447
1448 nd_jump_link(nd, &path);
1449 return NULL;
1450out:
1451 return ERR_PTR(error);
1452}
1453
1454static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1455{
1456 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1457 char *pathname;
1458 int len;
1459
1460 if (!tmp)
1461 return -ENOMEM;
1462
1463 pathname = d_path(path, tmp, PAGE_SIZE);
1464 len = PTR_ERR(pathname);
1465 if (IS_ERR(pathname))
1466 goto out;
1467 len = tmp + PAGE_SIZE - 1 - pathname;
1468
1469 if (len > buflen)
1470 len = buflen;
1471 if (copy_to_user(buffer, pathname, len))
1472 len = -EFAULT;
1473 out:
1474 free_page((unsigned long)tmp);
1475 return len;
1476}
1477
1478static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1479{
1480 int error = -EACCES;
1481 struct inode *inode = dentry->d_inode;
1482 struct path path;
1483
1484 /* Are we allowed to snoop on the tasks file descriptors? */
1485 if (!proc_fd_access_allowed(inode))
1486 goto out;
1487
1488 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1489 if (error)
1490 goto out;
1491
1492 error = do_proc_readlink(&path, buffer, buflen);
1493 path_put(&path);
1494out:
1495 return error;
1496}
1497
1498const struct inode_operations proc_pid_link_inode_operations = {
1499 .readlink = proc_pid_readlink,
1500 .follow_link = proc_pid_follow_link,
1501 .setattr = proc_setattr,
1502};
1503
1504
1505/* building an inode */
1506
1507struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1508{
1509 struct inode * inode;
1510 struct proc_inode *ei;
1511 const struct cred *cred;
1512
1513 /* We need a new inode */
1514
1515 inode = new_inode(sb);
1516 if (!inode)
1517 goto out;
1518
1519 /* Common stuff */
1520 ei = PROC_I(inode);
1521 inode->i_ino = get_next_ino();
1522 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1523 inode->i_op = &proc_def_inode_operations;
1524
1525 /*
1526 * grab the reference to task.
1527 */
1528 ei->pid = get_task_pid(task, PIDTYPE_PID);
1529 if (!ei->pid)
1530 goto out_unlock;
1531
1532 if (task_dumpable(task)) {
1533 rcu_read_lock();
1534 cred = __task_cred(task);
1535 inode->i_uid = cred->euid;
1536 inode->i_gid = cred->egid;
1537 rcu_read_unlock();
1538 }
1539 security_task_to_inode(task, inode);
1540
1541out:
1542 return inode;
1543
1544out_unlock:
1545 iput(inode);
1546 return NULL;
1547}
1548
1549int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1550{
1551 struct inode *inode = dentry->d_inode;
1552 struct task_struct *task;
1553 const struct cred *cred;
1554 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
1555
1556 generic_fillattr(inode, stat);
1557
1558 rcu_read_lock();
1559 stat->uid = GLOBAL_ROOT_UID;
1560 stat->gid = GLOBAL_ROOT_GID;
1561 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1562 if (task) {
1563 if (!has_pid_permissions(pid, task, 2)) {
1564 rcu_read_unlock();
1565 /*
1566 * This doesn't prevent learning whether PID exists,
1567 * it only makes getattr() consistent with readdir().
1568 */
1569 return -ENOENT;
1570 }
1571 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1572 task_dumpable(task)) {
1573 cred = __task_cred(task);
1574 stat->uid = cred->euid;
1575 stat->gid = cred->egid;
1576 }
1577 }
1578 rcu_read_unlock();
1579 return 0;
1580}
1581
1582/* dentry stuff */
1583
1584/*
1585 * Exceptional case: normally we are not allowed to unhash a busy
1586 * directory. In this case, however, we can do it - no aliasing problems
1587 * due to the way we treat inodes.
1588 *
1589 * Rewrite the inode's ownerships here because the owning task may have
1590 * performed a setuid(), etc.
1591 *
1592 * Before the /proc/pid/status file was created the only way to read
1593 * the effective uid of a /process was to stat /proc/pid. Reading
1594 * /proc/pid/status is slow enough that procps and other packages
1595 * kept stating /proc/pid. To keep the rules in /proc simple I have
1596 * made this apply to all per process world readable and executable
1597 * directories.
1598 */
1599int pid_revalidate(struct dentry *dentry, unsigned int flags)
1600{
1601 struct inode *inode;
1602 struct task_struct *task;
1603 const struct cred *cred;
1604
1605 if (flags & LOOKUP_RCU)
1606 return -ECHILD;
1607
1608 inode = dentry->d_inode;
1609 task = get_proc_task(inode);
1610
1611 if (task) {
1612 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1613 task_dumpable(task)) {
1614 rcu_read_lock();
1615 cred = __task_cred(task);
1616 inode->i_uid = cred->euid;
1617 inode->i_gid = cred->egid;
1618 rcu_read_unlock();
1619 } else {
1620 inode->i_uid = GLOBAL_ROOT_UID;
1621 inode->i_gid = GLOBAL_ROOT_GID;
1622 }
1623 inode->i_mode &= ~(S_ISUID | S_ISGID);
1624 security_task_to_inode(task, inode);
1625 put_task_struct(task);
1626 return 1;
1627 }
1628 d_drop(dentry);
1629 return 0;
1630}
1631
1632static inline bool proc_inode_is_dead(struct inode *inode)
1633{
1634 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1635}
1636
1637int pid_delete_dentry(const struct dentry *dentry)
1638{
1639 /* Is the task we represent dead?
1640 * If so, then don't put the dentry on the lru list,
1641 * kill it immediately.
1642 */
1643 return proc_inode_is_dead(dentry->d_inode);
1644}
1645
1646const struct dentry_operations pid_dentry_operations =
1647{
1648 .d_revalidate = pid_revalidate,
1649 .d_delete = pid_delete_dentry,
1650};
1651
1652/* Lookups */
1653
1654/*
1655 * Fill a directory entry.
1656 *
1657 * If possible create the dcache entry and derive our inode number and
1658 * file type from dcache entry.
1659 *
1660 * Since all of the proc inode numbers are dynamically generated, the inode
1661 * numbers do not exist until the inode is cache. This means creating the
1662 * the dcache entry in readdir is necessary to keep the inode numbers
1663 * reported by readdir in sync with the inode numbers reported
1664 * by stat.
1665 */
1666bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1667 const char *name, int len,
1668 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1669{
1670 struct dentry *child, *dir = file->f_path.dentry;
1671 struct qstr qname = QSTR_INIT(name, len);
1672 struct inode *inode;
1673 unsigned type;
1674 ino_t ino;
1675
1676 child = d_hash_and_lookup(dir, &qname);
1677 if (!child) {
1678 child = d_alloc(dir, &qname);
1679 if (!child)
1680 goto end_instantiate;
1681 if (instantiate(dir->d_inode, child, task, ptr) < 0) {
1682 dput(child);
1683 goto end_instantiate;
1684 }
1685 }
1686 inode = child->d_inode;
1687 ino = inode->i_ino;
1688 type = inode->i_mode >> 12;
1689 dput(child);
1690 return dir_emit(ctx, name, len, ino, type);
1691
1692end_instantiate:
1693 return dir_emit(ctx, name, len, 1, DT_UNKNOWN);
1694}
1695
1696#ifdef CONFIG_CHECKPOINT_RESTORE
1697
1698/*
1699 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1700 * which represent vma start and end addresses.
1701 */
1702static int dname_to_vma_addr(struct dentry *dentry,
1703 unsigned long *start, unsigned long *end)
1704{
1705 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
1706 return -EINVAL;
1707
1708 return 0;
1709}
1710
1711static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1712{
1713 unsigned long vm_start, vm_end;
1714 bool exact_vma_exists = false;
1715 struct mm_struct *mm = NULL;
1716 struct task_struct *task;
1717 const struct cred *cred;
1718 struct inode *inode;
1719 int status = 0;
1720
1721 if (flags & LOOKUP_RCU)
1722 return -ECHILD;
1723
1724 if (!capable(CAP_SYS_ADMIN)) {
1725 status = -EPERM;
1726 goto out_notask;
1727 }
1728
1729 inode = dentry->d_inode;
1730 task = get_proc_task(inode);
1731 if (!task)
1732 goto out_notask;
1733
1734 mm = mm_access(task, PTRACE_MODE_READ);
1735 if (IS_ERR_OR_NULL(mm))
1736 goto out;
1737
1738 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1739 down_read(&mm->mmap_sem);
1740 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1741 up_read(&mm->mmap_sem);
1742 }
1743
1744 mmput(mm);
1745
1746 if (exact_vma_exists) {
1747 if (task_dumpable(task)) {
1748 rcu_read_lock();
1749 cred = __task_cred(task);
1750 inode->i_uid = cred->euid;
1751 inode->i_gid = cred->egid;
1752 rcu_read_unlock();
1753 } else {
1754 inode->i_uid = GLOBAL_ROOT_UID;
1755 inode->i_gid = GLOBAL_ROOT_GID;
1756 }
1757 security_task_to_inode(task, inode);
1758 status = 1;
1759 }
1760
1761out:
1762 put_task_struct(task);
1763
1764out_notask:
1765 if (status <= 0)
1766 d_drop(dentry);
1767
1768 return status;
1769}
1770
1771static const struct dentry_operations tid_map_files_dentry_operations = {
1772 .d_revalidate = map_files_d_revalidate,
1773 .d_delete = pid_delete_dentry,
1774};
1775
1776static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
1777{
1778 unsigned long vm_start, vm_end;
1779 struct vm_area_struct *vma;
1780 struct task_struct *task;
1781 struct mm_struct *mm;
1782 int rc;
1783
1784 rc = -ENOENT;
1785 task = get_proc_task(dentry->d_inode);
1786 if (!task)
1787 goto out;
1788
1789 mm = get_task_mm(task);
1790 put_task_struct(task);
1791 if (!mm)
1792 goto out;
1793
1794 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
1795 if (rc)
1796 goto out_mmput;
1797
1798 rc = -ENOENT;
1799 down_read(&mm->mmap_sem);
1800 vma = find_exact_vma(mm, vm_start, vm_end);
1801 if (vma && vma->vm_file) {
1802 *path = vma->vm_file->f_path;
1803 path_get(path);
1804 rc = 0;
1805 }
1806 up_read(&mm->mmap_sem);
1807
1808out_mmput:
1809 mmput(mm);
1810out:
1811 return rc;
1812}
1813
1814struct map_files_info {
1815 fmode_t mode;
1816 unsigned long len;
1817 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
1818};
1819
1820static int
1821proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
1822 struct task_struct *task, const void *ptr)
1823{
1824 fmode_t mode = (fmode_t)(unsigned long)ptr;
1825 struct proc_inode *ei;
1826 struct inode *inode;
1827
1828 inode = proc_pid_make_inode(dir->i_sb, task);
1829 if (!inode)
1830 return -ENOENT;
1831
1832 ei = PROC_I(inode);
1833 ei->op.proc_get_link = proc_map_files_get_link;
1834
1835 inode->i_op = &proc_pid_link_inode_operations;
1836 inode->i_size = 64;
1837 inode->i_mode = S_IFLNK;
1838
1839 if (mode & FMODE_READ)
1840 inode->i_mode |= S_IRUSR;
1841 if (mode & FMODE_WRITE)
1842 inode->i_mode |= S_IWUSR;
1843
1844 d_set_d_op(dentry, &tid_map_files_dentry_operations);
1845 d_add(dentry, inode);
1846
1847 return 0;
1848}
1849
1850static struct dentry *proc_map_files_lookup(struct inode *dir,
1851 struct dentry *dentry, unsigned int flags)
1852{
1853 unsigned long vm_start, vm_end;
1854 struct vm_area_struct *vma;
1855 struct task_struct *task;
1856 int result;
1857 struct mm_struct *mm;
1858
1859 result = -EPERM;
1860 if (!capable(CAP_SYS_ADMIN))
1861 goto out;
1862
1863 result = -ENOENT;
1864 task = get_proc_task(dir);
1865 if (!task)
1866 goto out;
1867
1868 result = -EACCES;
1869 if (!ptrace_may_access(task, PTRACE_MODE_READ))
1870 goto out_put_task;
1871
1872 result = -ENOENT;
1873 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
1874 goto out_put_task;
1875
1876 mm = get_task_mm(task);
1877 if (!mm)
1878 goto out_put_task;
1879
1880 down_read(&mm->mmap_sem);
1881 vma = find_exact_vma(mm, vm_start, vm_end);
1882 if (!vma)
1883 goto out_no_vma;
1884
1885 if (vma->vm_file)
1886 result = proc_map_files_instantiate(dir, dentry, task,
1887 (void *)(unsigned long)vma->vm_file->f_mode);
1888
1889out_no_vma:
1890 up_read(&mm->mmap_sem);
1891 mmput(mm);
1892out_put_task:
1893 put_task_struct(task);
1894out:
1895 return ERR_PTR(result);
1896}
1897
1898static const struct inode_operations proc_map_files_inode_operations = {
1899 .lookup = proc_map_files_lookup,
1900 .permission = proc_fd_permission,
1901 .setattr = proc_setattr,
1902};
1903
1904static int
1905proc_map_files_readdir(struct file *file, struct dir_context *ctx)
1906{
1907 struct vm_area_struct *vma;
1908 struct task_struct *task;
1909 struct mm_struct *mm;
1910 unsigned long nr_files, pos, i;
1911 struct flex_array *fa = NULL;
1912 struct map_files_info info;
1913 struct map_files_info *p;
1914 int ret;
1915
1916 ret = -EPERM;
1917 if (!capable(CAP_SYS_ADMIN))
1918 goto out;
1919
1920 ret = -ENOENT;
1921 task = get_proc_task(file_inode(file));
1922 if (!task)
1923 goto out;
1924
1925 ret = -EACCES;
1926 if (!ptrace_may_access(task, PTRACE_MODE_READ))
1927 goto out_put_task;
1928
1929 ret = 0;
1930 if (!dir_emit_dots(file, ctx))
1931 goto out_put_task;
1932
1933 mm = get_task_mm(task);
1934 if (!mm)
1935 goto out_put_task;
1936 down_read(&mm->mmap_sem);
1937
1938 nr_files = 0;
1939
1940 /*
1941 * We need two passes here:
1942 *
1943 * 1) Collect vmas of mapped files with mmap_sem taken
1944 * 2) Release mmap_sem and instantiate entries
1945 *
1946 * otherwise we get lockdep complained, since filldir()
1947 * routine might require mmap_sem taken in might_fault().
1948 */
1949
1950 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
1951 if (vma->vm_file && ++pos > ctx->pos)
1952 nr_files++;
1953 }
1954
1955 if (nr_files) {
1956 fa = flex_array_alloc(sizeof(info), nr_files,
1957 GFP_KERNEL);
1958 if (!fa || flex_array_prealloc(fa, 0, nr_files,
1959 GFP_KERNEL)) {
1960 ret = -ENOMEM;
1961 if (fa)
1962 flex_array_free(fa);
1963 up_read(&mm->mmap_sem);
1964 mmput(mm);
1965 goto out_put_task;
1966 }
1967 for (i = 0, vma = mm->mmap, pos = 2; vma;
1968 vma = vma->vm_next) {
1969 if (!vma->vm_file)
1970 continue;
1971 if (++pos <= ctx->pos)
1972 continue;
1973
1974 info.mode = vma->vm_file->f_mode;
1975 info.len = snprintf(info.name,
1976 sizeof(info.name), "%lx-%lx",
1977 vma->vm_start, vma->vm_end);
1978 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
1979 BUG();
1980 }
1981 }
1982 up_read(&mm->mmap_sem);
1983
1984 for (i = 0; i < nr_files; i++) {
1985 p = flex_array_get(fa, i);
1986 if (!proc_fill_cache(file, ctx,
1987 p->name, p->len,
1988 proc_map_files_instantiate,
1989 task,
1990 (void *)(unsigned long)p->mode))
1991 break;
1992 ctx->pos++;
1993 }
1994 if (fa)
1995 flex_array_free(fa);
1996 mmput(mm);
1997
1998out_put_task:
1999 put_task_struct(task);
2000out:
2001 return ret;
2002}
2003
2004static const struct file_operations proc_map_files_operations = {
2005 .read = generic_read_dir,
2006 .iterate = proc_map_files_readdir,
2007 .llseek = default_llseek,
2008};
2009
2010struct timers_private {
2011 struct pid *pid;
2012 struct task_struct *task;
2013 struct sighand_struct *sighand;
2014 struct pid_namespace *ns;
2015 unsigned long flags;
2016};
2017
2018static void *timers_start(struct seq_file *m, loff_t *pos)
2019{
2020 struct timers_private *tp = m->private;
2021
2022 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2023 if (!tp->task)
2024 return ERR_PTR(-ESRCH);
2025
2026 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2027 if (!tp->sighand)
2028 return ERR_PTR(-ESRCH);
2029
2030 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2031}
2032
2033static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2034{
2035 struct timers_private *tp = m->private;
2036 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2037}
2038
2039static void timers_stop(struct seq_file *m, void *v)
2040{
2041 struct timers_private *tp = m->private;
2042
2043 if (tp->sighand) {
2044 unlock_task_sighand(tp->task, &tp->flags);
2045 tp->sighand = NULL;
2046 }
2047
2048 if (tp->task) {
2049 put_task_struct(tp->task);
2050 tp->task = NULL;
2051 }
2052}
2053
2054static int show_timer(struct seq_file *m, void *v)
2055{
2056 struct k_itimer *timer;
2057 struct timers_private *tp = m->private;
2058 int notify;
2059 static char *nstr[] = {
2060 [SIGEV_SIGNAL] = "signal",
2061 [SIGEV_NONE] = "none",
2062 [SIGEV_THREAD] = "thread",
2063 };
2064
2065 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2066 notify = timer->it_sigev_notify;
2067
2068 seq_printf(m, "ID: %d\n", timer->it_id);
2069 seq_printf(m, "signal: %d/%p\n", timer->sigq->info.si_signo,
2070 timer->sigq->info.si_value.sival_ptr);
2071 seq_printf(m, "notify: %s/%s.%d\n",
2072 nstr[notify & ~SIGEV_THREAD_ID],
2073 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2074 pid_nr_ns(timer->it_pid, tp->ns));
2075 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2076
2077 return 0;
2078}
2079
2080static const struct seq_operations proc_timers_seq_ops = {
2081 .start = timers_start,
2082 .next = timers_next,
2083 .stop = timers_stop,
2084 .show = show_timer,
2085};
2086
2087static int proc_timers_open(struct inode *inode, struct file *file)
2088{
2089 struct timers_private *tp;
2090
2091 tp = __seq_open_private(file, &proc_timers_seq_ops,
2092 sizeof(struct timers_private));
2093 if (!tp)
2094 return -ENOMEM;
2095
2096 tp->pid = proc_pid(inode);
2097 tp->ns = inode->i_sb->s_fs_info;
2098 return 0;
2099}
2100
2101static const struct file_operations proc_timers_operations = {
2102 .open = proc_timers_open,
2103 .read = seq_read,
2104 .llseek = seq_lseek,
2105 .release = seq_release_private,
2106};
2107#endif /* CONFIG_CHECKPOINT_RESTORE */
2108
2109static int proc_pident_instantiate(struct inode *dir,
2110 struct dentry *dentry, struct task_struct *task, const void *ptr)
2111{
2112 const struct pid_entry *p = ptr;
2113 struct inode *inode;
2114 struct proc_inode *ei;
2115
2116 inode = proc_pid_make_inode(dir->i_sb, task);
2117 if (!inode)
2118 goto out;
2119
2120 ei = PROC_I(inode);
2121 inode->i_mode = p->mode;
2122 if (S_ISDIR(inode->i_mode))
2123 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2124 if (p->iop)
2125 inode->i_op = p->iop;
2126 if (p->fop)
2127 inode->i_fop = p->fop;
2128 ei->op = p->op;
2129 d_set_d_op(dentry, &pid_dentry_operations);
2130 d_add(dentry, inode);
2131 /* Close the race of the process dying before we return the dentry */
2132 if (pid_revalidate(dentry, 0))
2133 return 0;
2134out:
2135 return -ENOENT;
2136}
2137
2138static struct dentry *proc_pident_lookup(struct inode *dir,
2139 struct dentry *dentry,
2140 const struct pid_entry *ents,
2141 unsigned int nents)
2142{
2143 int error;
2144 struct task_struct *task = get_proc_task(dir);
2145 const struct pid_entry *p, *last;
2146
2147 error = -ENOENT;
2148
2149 if (!task)
2150 goto out_no_task;
2151
2152 /*
2153 * Yes, it does not scale. And it should not. Don't add
2154 * new entries into /proc/<tgid>/ without very good reasons.
2155 */
2156 last = &ents[nents - 1];
2157 for (p = ents; p <= last; p++) {
2158 if (p->len != dentry->d_name.len)
2159 continue;
2160 if (!memcmp(dentry->d_name.name, p->name, p->len))
2161 break;
2162 }
2163 if (p > last)
2164 goto out;
2165
2166 error = proc_pident_instantiate(dir, dentry, task, p);
2167out:
2168 put_task_struct(task);
2169out_no_task:
2170 return ERR_PTR(error);
2171}
2172
2173static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2174 const struct pid_entry *ents, unsigned int nents)
2175{
2176 struct task_struct *task = get_proc_task(file_inode(file));
2177 const struct pid_entry *p;
2178
2179 if (!task)
2180 return -ENOENT;
2181
2182 if (!dir_emit_dots(file, ctx))
2183 goto out;
2184
2185 if (ctx->pos >= nents + 2)
2186 goto out;
2187
2188 for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) {
2189 if (!proc_fill_cache(file, ctx, p->name, p->len,
2190 proc_pident_instantiate, task, p))
2191 break;
2192 ctx->pos++;
2193 }
2194out:
2195 put_task_struct(task);
2196 return 0;
2197}
2198
2199#ifdef CONFIG_SECURITY
2200static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2201 size_t count, loff_t *ppos)
2202{
2203 struct inode * inode = file_inode(file);
2204 char *p = NULL;
2205 ssize_t length;
2206 struct task_struct *task = get_proc_task(inode);
2207
2208 if (!task)
2209 return -ESRCH;
2210
2211 length = security_getprocattr(task,
2212 (char*)file->f_path.dentry->d_name.name,
2213 &p);
2214 put_task_struct(task);
2215 if (length > 0)
2216 length = simple_read_from_buffer(buf, count, ppos, p, length);
2217 kfree(p);
2218 return length;
2219}
2220
2221static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2222 size_t count, loff_t *ppos)
2223{
2224 struct inode * inode = file_inode(file);
2225 char *page;
2226 ssize_t length;
2227 struct task_struct *task = get_proc_task(inode);
2228
2229 length = -ESRCH;
2230 if (!task)
2231 goto out_no_task;
2232 if (count > PAGE_SIZE)
2233 count = PAGE_SIZE;
2234
2235 /* No partial writes. */
2236 length = -EINVAL;
2237 if (*ppos != 0)
2238 goto out;
2239
2240 length = -ENOMEM;
2241 page = (char*)__get_free_page(GFP_TEMPORARY);
2242 if (!page)
2243 goto out;
2244
2245 length = -EFAULT;
2246 if (copy_from_user(page, buf, count))
2247 goto out_free;
2248
2249 /* Guard against adverse ptrace interaction */
2250 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2251 if (length < 0)
2252 goto out_free;
2253
2254 length = security_setprocattr(task,
2255 (char*)file->f_path.dentry->d_name.name,
2256 (void*)page, count);
2257 mutex_unlock(&task->signal->cred_guard_mutex);
2258out_free:
2259 free_page((unsigned long) page);
2260out:
2261 put_task_struct(task);
2262out_no_task:
2263 return length;
2264}
2265
2266static const struct file_operations proc_pid_attr_operations = {
2267 .read = proc_pid_attr_read,
2268 .write = proc_pid_attr_write,
2269 .llseek = generic_file_llseek,
2270};
2271
2272static const struct pid_entry attr_dir_stuff[] = {
2273 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2274 REG("prev", S_IRUGO, proc_pid_attr_operations),
2275 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2276 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2277 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2278 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2279};
2280
2281static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2282{
2283 return proc_pident_readdir(file, ctx,
2284 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2285}
2286
2287static const struct file_operations proc_attr_dir_operations = {
2288 .read = generic_read_dir,
2289 .iterate = proc_attr_dir_readdir,
2290 .llseek = default_llseek,
2291};
2292
2293static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2294 struct dentry *dentry, unsigned int flags)
2295{
2296 return proc_pident_lookup(dir, dentry,
2297 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2298}
2299
2300static const struct inode_operations proc_attr_dir_inode_operations = {
2301 .lookup = proc_attr_dir_lookup,
2302 .getattr = pid_getattr,
2303 .setattr = proc_setattr,
2304};
2305
2306#endif
2307
2308#ifdef CONFIG_ELF_CORE
2309static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2310 size_t count, loff_t *ppos)
2311{
2312 struct task_struct *task = get_proc_task(file_inode(file));
2313 struct mm_struct *mm;
2314 char buffer[PROC_NUMBUF];
2315 size_t len;
2316 int ret;
2317
2318 if (!task)
2319 return -ESRCH;
2320
2321 ret = 0;
2322 mm = get_task_mm(task);
2323 if (mm) {
2324 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2325 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2326 MMF_DUMP_FILTER_SHIFT));
2327 mmput(mm);
2328 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2329 }
2330
2331 put_task_struct(task);
2332
2333 return ret;
2334}
2335
2336static ssize_t proc_coredump_filter_write(struct file *file,
2337 const char __user *buf,
2338 size_t count,
2339 loff_t *ppos)
2340{
2341 struct task_struct *task;
2342 struct mm_struct *mm;
2343 char buffer[PROC_NUMBUF], *end;
2344 unsigned int val;
2345 int ret;
2346 int i;
2347 unsigned long mask;
2348
2349 ret = -EFAULT;
2350 memset(buffer, 0, sizeof(buffer));
2351 if (count > sizeof(buffer) - 1)
2352 count = sizeof(buffer) - 1;
2353 if (copy_from_user(buffer, buf, count))
2354 goto out_no_task;
2355
2356 ret = -EINVAL;
2357 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2358 if (*end == '\n')
2359 end++;
2360 if (end - buffer == 0)
2361 goto out_no_task;
2362
2363 ret = -ESRCH;
2364 task = get_proc_task(file_inode(file));
2365 if (!task)
2366 goto out_no_task;
2367
2368 ret = end - buffer;
2369 mm = get_task_mm(task);
2370 if (!mm)
2371 goto out_no_mm;
2372
2373 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2374 if (val & mask)
2375 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2376 else
2377 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2378 }
2379
2380 mmput(mm);
2381 out_no_mm:
2382 put_task_struct(task);
2383 out_no_task:
2384 return ret;
2385}
2386
2387static const struct file_operations proc_coredump_filter_operations = {
2388 .read = proc_coredump_filter_read,
2389 .write = proc_coredump_filter_write,
2390 .llseek = generic_file_llseek,
2391};
2392#endif
2393
2394#ifdef CONFIG_TASK_IO_ACCOUNTING
2395static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2396{
2397 struct task_io_accounting acct = task->ioac;
2398 unsigned long flags;
2399 int result;
2400
2401 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2402 if (result)
2403 return result;
2404
2405 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2406 result = -EACCES;
2407 goto out_unlock;
2408 }
2409
2410 if (whole && lock_task_sighand(task, &flags)) {
2411 struct task_struct *t = task;
2412
2413 task_io_accounting_add(&acct, &task->signal->ioac);
2414 while_each_thread(task, t)
2415 task_io_accounting_add(&acct, &t->ioac);
2416
2417 unlock_task_sighand(task, &flags);
2418 }
2419 result = sprintf(buffer,
2420 "rchar: %llu\n"
2421 "wchar: %llu\n"
2422 "syscr: %llu\n"
2423 "syscw: %llu\n"
2424 "read_bytes: %llu\n"
2425 "write_bytes: %llu\n"
2426 "cancelled_write_bytes: %llu\n",
2427 (unsigned long long)acct.rchar,
2428 (unsigned long long)acct.wchar,
2429 (unsigned long long)acct.syscr,
2430 (unsigned long long)acct.syscw,
2431 (unsigned long long)acct.read_bytes,
2432 (unsigned long long)acct.write_bytes,
2433 (unsigned long long)acct.cancelled_write_bytes);
2434out_unlock:
2435 mutex_unlock(&task->signal->cred_guard_mutex);
2436 return result;
2437}
2438
2439static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2440{
2441 return do_io_accounting(task, buffer, 0);
2442}
2443
2444static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2445{
2446 return do_io_accounting(task, buffer, 1);
2447}
2448#endif /* CONFIG_TASK_IO_ACCOUNTING */
2449
2450#ifdef CONFIG_USER_NS
2451static int proc_id_map_open(struct inode *inode, struct file *file,
2452 struct seq_operations *seq_ops)
2453{
2454 struct user_namespace *ns = NULL;
2455 struct task_struct *task;
2456 struct seq_file *seq;
2457 int ret = -EINVAL;
2458
2459 task = get_proc_task(inode);
2460 if (task) {
2461 rcu_read_lock();
2462 ns = get_user_ns(task_cred_xxx(task, user_ns));
2463 rcu_read_unlock();
2464 put_task_struct(task);
2465 }
2466 if (!ns)
2467 goto err;
2468
2469 ret = seq_open(file, seq_ops);
2470 if (ret)
2471 goto err_put_ns;
2472
2473 seq = file->private_data;
2474 seq->private = ns;
2475
2476 return 0;
2477err_put_ns:
2478 put_user_ns(ns);
2479err:
2480 return ret;
2481}
2482
2483static int proc_id_map_release(struct inode *inode, struct file *file)
2484{
2485 struct seq_file *seq = file->private_data;
2486 struct user_namespace *ns = seq->private;
2487 put_user_ns(ns);
2488 return seq_release(inode, file);
2489}
2490
2491static int proc_uid_map_open(struct inode *inode, struct file *file)
2492{
2493 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2494}
2495
2496static int proc_gid_map_open(struct inode *inode, struct file *file)
2497{
2498 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2499}
2500
2501static int proc_projid_map_open(struct inode *inode, struct file *file)
2502{
2503 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2504}
2505
2506static const struct file_operations proc_uid_map_operations = {
2507 .open = proc_uid_map_open,
2508 .write = proc_uid_map_write,
2509 .read = seq_read,
2510 .llseek = seq_lseek,
2511 .release = proc_id_map_release,
2512};
2513
2514static const struct file_operations proc_gid_map_operations = {
2515 .open = proc_gid_map_open,
2516 .write = proc_gid_map_write,
2517 .read = seq_read,
2518 .llseek = seq_lseek,
2519 .release = proc_id_map_release,
2520};
2521
2522static const struct file_operations proc_projid_map_operations = {
2523 .open = proc_projid_map_open,
2524 .write = proc_projid_map_write,
2525 .read = seq_read,
2526 .llseek = seq_lseek,
2527 .release = proc_id_map_release,
2528};
2529#endif /* CONFIG_USER_NS */
2530
2531static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2532 struct pid *pid, struct task_struct *task)
2533{
2534 int err = lock_trace(task);
2535 if (!err) {
2536 seq_printf(m, "%08x\n", task->personality);
2537 unlock_trace(task);
2538 }
2539 return err;
2540}
2541
2542/*
2543 * Thread groups
2544 */
2545static const struct file_operations proc_task_operations;
2546static const struct inode_operations proc_task_inode_operations;
2547
2548static const struct pid_entry tgid_base_stuff[] = {
2549 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2550 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2551#ifdef CONFIG_CHECKPOINT_RESTORE
2552 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2553#endif
2554 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2555 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2556#ifdef CONFIG_NET
2557 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2558#endif
2559 REG("environ", S_IRUSR, proc_environ_operations),
2560 INF("auxv", S_IRUSR, proc_pid_auxv),
2561 ONE("status", S_IRUGO, proc_pid_status),
2562 ONE("personality", S_IRUSR, proc_pid_personality),
2563 INF("limits", S_IRUGO, proc_pid_limits),
2564#ifdef CONFIG_SCHED_DEBUG
2565 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2566#endif
2567#ifdef CONFIG_SCHED_AUTOGROUP
2568 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2569#endif
2570 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2571#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2572 INF("syscall", S_IRUSR, proc_pid_syscall),
2573#endif
2574 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2575 ONE("stat", S_IRUGO, proc_tgid_stat),
2576 ONE("statm", S_IRUGO, proc_pid_statm),
2577 REG("maps", S_IRUGO, proc_pid_maps_operations),
2578#ifdef CONFIG_NUMA
2579 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
2580#endif
2581 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2582 LNK("cwd", proc_cwd_link),
2583 LNK("root", proc_root_link),
2584 LNK("exe", proc_exe_link),
2585 REG("mounts", S_IRUGO, proc_mounts_operations),
2586 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2587 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2588#ifdef CONFIG_PROC_PAGE_MONITOR
2589 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2590 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
2591 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2592#endif
2593#ifdef CONFIG_SECURITY
2594 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2595#endif
2596#ifdef CONFIG_KALLSYMS
2597 INF("wchan", S_IRUGO, proc_pid_wchan),
2598#endif
2599#ifdef CONFIG_STACKTRACE
2600 ONE("stack", S_IRUSR, proc_pid_stack),
2601#endif
2602#ifdef CONFIG_SCHEDSTATS
2603 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2604#endif
2605#ifdef CONFIG_LATENCYTOP
2606 REG("latency", S_IRUGO, proc_lstats_operations),
2607#endif
2608#ifdef CONFIG_PROC_PID_CPUSET
2609 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2610#endif
2611#ifdef CONFIG_CGROUPS
2612 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2613#endif
2614 INF("oom_score", S_IRUGO, proc_oom_score),
2615 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
2616 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2617#ifdef CONFIG_AUDITSYSCALL
2618 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2619 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2620#endif
2621#ifdef CONFIG_FAULT_INJECTION
2622 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2623#endif
2624#ifdef CONFIG_ELF_CORE
2625 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2626#endif
2627#ifdef CONFIG_TASK_IO_ACCOUNTING
2628 INF("io", S_IRUSR, proc_tgid_io_accounting),
2629#endif
2630#ifdef CONFIG_HARDWALL
2631 INF("hardwall", S_IRUGO, proc_pid_hardwall),
2632#endif
2633#ifdef CONFIG_USER_NS
2634 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
2635 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
2636 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
2637#endif
2638#ifdef CONFIG_CHECKPOINT_RESTORE
2639 REG("timers", S_IRUGO, proc_timers_operations),
2640#endif
2641};
2642
2643static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
2644{
2645 return proc_pident_readdir(file, ctx,
2646 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2647}
2648
2649static const struct file_operations proc_tgid_base_operations = {
2650 .read = generic_read_dir,
2651 .iterate = proc_tgid_base_readdir,
2652 .llseek = default_llseek,
2653};
2654
2655static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
2656{
2657 return proc_pident_lookup(dir, dentry,
2658 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2659}
2660
2661static const struct inode_operations proc_tgid_base_inode_operations = {
2662 .lookup = proc_tgid_base_lookup,
2663 .getattr = pid_getattr,
2664 .setattr = proc_setattr,
2665 .permission = proc_pid_permission,
2666};
2667
2668static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2669{
2670 struct dentry *dentry, *leader, *dir;
2671 char buf[PROC_NUMBUF];
2672 struct qstr name;
2673
2674 name.name = buf;
2675 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2676 /* no ->d_hash() rejects on procfs */
2677 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2678 if (dentry) {
2679 shrink_dcache_parent(dentry);
2680 d_drop(dentry);
2681 dput(dentry);
2682 }
2683
2684 name.name = buf;
2685 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2686 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2687 if (!leader)
2688 goto out;
2689
2690 name.name = "task";
2691 name.len = strlen(name.name);
2692 dir = d_hash_and_lookup(leader, &name);
2693 if (!dir)
2694 goto out_put_leader;
2695
2696 name.name = buf;
2697 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2698 dentry = d_hash_and_lookup(dir, &name);
2699 if (dentry) {
2700 shrink_dcache_parent(dentry);
2701 d_drop(dentry);
2702 dput(dentry);
2703 }
2704
2705 dput(dir);
2706out_put_leader:
2707 dput(leader);
2708out:
2709 return;
2710}
2711
2712/**
2713 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2714 * @task: task that should be flushed.
2715 *
2716 * When flushing dentries from proc, one needs to flush them from global
2717 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2718 * in. This call is supposed to do all of this job.
2719 *
2720 * Looks in the dcache for
2721 * /proc/@pid
2722 * /proc/@tgid/task/@pid
2723 * if either directory is present flushes it and all of it'ts children
2724 * from the dcache.
2725 *
2726 * It is safe and reasonable to cache /proc entries for a task until
2727 * that task exits. After that they just clog up the dcache with
2728 * useless entries, possibly causing useful dcache entries to be
2729 * flushed instead. This routine is proved to flush those useless
2730 * dcache entries at process exit time.
2731 *
2732 * NOTE: This routine is just an optimization so it does not guarantee
2733 * that no dcache entries will exist at process exit time it
2734 * just makes it very unlikely that any will persist.
2735 */
2736
2737void proc_flush_task(struct task_struct *task)
2738{
2739 int i;
2740 struct pid *pid, *tgid;
2741 struct upid *upid;
2742
2743 pid = task_pid(task);
2744 tgid = task_tgid(task);
2745
2746 for (i = 0; i <= pid->level; i++) {
2747 upid = &pid->numbers[i];
2748 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2749 tgid->numbers[i].nr);
2750 }
2751}
2752
2753static int proc_pid_instantiate(struct inode *dir,
2754 struct dentry * dentry,
2755 struct task_struct *task, const void *ptr)
2756{
2757 struct inode *inode;
2758
2759 inode = proc_pid_make_inode(dir->i_sb, task);
2760 if (!inode)
2761 goto out;
2762
2763 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2764 inode->i_op = &proc_tgid_base_inode_operations;
2765 inode->i_fop = &proc_tgid_base_operations;
2766 inode->i_flags|=S_IMMUTABLE;
2767
2768 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
2769 ARRAY_SIZE(tgid_base_stuff)));
2770
2771 d_set_d_op(dentry, &pid_dentry_operations);
2772
2773 d_add(dentry, inode);
2774 /* Close the race of the process dying before we return the dentry */
2775 if (pid_revalidate(dentry, 0))
2776 return 0;
2777out:
2778 return -ENOENT;
2779}
2780
2781struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
2782{
2783 int result = 0;
2784 struct task_struct *task;
2785 unsigned tgid;
2786 struct pid_namespace *ns;
2787
2788 tgid = name_to_int(dentry);
2789 if (tgid == ~0U)
2790 goto out;
2791
2792 ns = dentry->d_sb->s_fs_info;
2793 rcu_read_lock();
2794 task = find_task_by_pid_ns(tgid, ns);
2795 if (task)
2796 get_task_struct(task);
2797 rcu_read_unlock();
2798 if (!task)
2799 goto out;
2800
2801 result = proc_pid_instantiate(dir, dentry, task, NULL);
2802 put_task_struct(task);
2803out:
2804 return ERR_PTR(result);
2805}
2806
2807/*
2808 * Find the first task with tgid >= tgid
2809 *
2810 */
2811struct tgid_iter {
2812 unsigned int tgid;
2813 struct task_struct *task;
2814};
2815static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2816{
2817 struct pid *pid;
2818
2819 if (iter.task)
2820 put_task_struct(iter.task);
2821 rcu_read_lock();
2822retry:
2823 iter.task = NULL;
2824 pid = find_ge_pid(iter.tgid, ns);
2825 if (pid) {
2826 iter.tgid = pid_nr_ns(pid, ns);
2827 iter.task = pid_task(pid, PIDTYPE_PID);
2828 /* What we to know is if the pid we have find is the
2829 * pid of a thread_group_leader. Testing for task
2830 * being a thread_group_leader is the obvious thing
2831 * todo but there is a window when it fails, due to
2832 * the pid transfer logic in de_thread.
2833 *
2834 * So we perform the straight forward test of seeing
2835 * if the pid we have found is the pid of a thread
2836 * group leader, and don't worry if the task we have
2837 * found doesn't happen to be a thread group leader.
2838 * As we don't care in the case of readdir.
2839 */
2840 if (!iter.task || !has_group_leader_pid(iter.task)) {
2841 iter.tgid += 1;
2842 goto retry;
2843 }
2844 get_task_struct(iter.task);
2845 }
2846 rcu_read_unlock();
2847 return iter;
2848}
2849
2850#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 1)
2851
2852/* for the /proc/ directory itself, after non-process stuff has been done */
2853int proc_pid_readdir(struct file *file, struct dir_context *ctx)
2854{
2855 struct tgid_iter iter;
2856 struct pid_namespace *ns = file->f_dentry->d_sb->s_fs_info;
2857 loff_t pos = ctx->pos;
2858
2859 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
2860 return 0;
2861
2862 if (pos == TGID_OFFSET - 1) {
2863 struct inode *inode = ns->proc_self->d_inode;
2864 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
2865 return 0;
2866 iter.tgid = 0;
2867 } else {
2868 iter.tgid = pos - TGID_OFFSET;
2869 }
2870 iter.task = NULL;
2871 for (iter = next_tgid(ns, iter);
2872 iter.task;
2873 iter.tgid += 1, iter = next_tgid(ns, iter)) {
2874 char name[PROC_NUMBUF];
2875 int len;
2876 if (!has_pid_permissions(ns, iter.task, 2))
2877 continue;
2878
2879 len = snprintf(name, sizeof(name), "%d", iter.tgid);
2880 ctx->pos = iter.tgid + TGID_OFFSET;
2881 if (!proc_fill_cache(file, ctx, name, len,
2882 proc_pid_instantiate, iter.task, NULL)) {
2883 put_task_struct(iter.task);
2884 return 0;
2885 }
2886 }
2887 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
2888 return 0;
2889}
2890
2891/*
2892 * Tasks
2893 */
2894static const struct pid_entry tid_base_stuff[] = {
2895 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2896 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2897 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2898 REG("environ", S_IRUSR, proc_environ_operations),
2899 INF("auxv", S_IRUSR, proc_pid_auxv),
2900 ONE("status", S_IRUGO, proc_pid_status),
2901 ONE("personality", S_IRUSR, proc_pid_personality),
2902 INF("limits", S_IRUGO, proc_pid_limits),
2903#ifdef CONFIG_SCHED_DEBUG
2904 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2905#endif
2906 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2907#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2908 INF("syscall", S_IRUSR, proc_pid_syscall),
2909#endif
2910 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2911 ONE("stat", S_IRUGO, proc_tid_stat),
2912 ONE("statm", S_IRUGO, proc_pid_statm),
2913 REG("maps", S_IRUGO, proc_tid_maps_operations),
2914#ifdef CONFIG_CHECKPOINT_RESTORE
2915 REG("children", S_IRUGO, proc_tid_children_operations),
2916#endif
2917#ifdef CONFIG_NUMA
2918 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
2919#endif
2920 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2921 LNK("cwd", proc_cwd_link),
2922 LNK("root", proc_root_link),
2923 LNK("exe", proc_exe_link),
2924 REG("mounts", S_IRUGO, proc_mounts_operations),
2925 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2926#ifdef CONFIG_PROC_PAGE_MONITOR
2927 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2928 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
2929 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2930#endif
2931#ifdef CONFIG_SECURITY
2932 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2933#endif
2934#ifdef CONFIG_KALLSYMS
2935 INF("wchan", S_IRUGO, proc_pid_wchan),
2936#endif
2937#ifdef CONFIG_STACKTRACE
2938 ONE("stack", S_IRUSR, proc_pid_stack),
2939#endif
2940#ifdef CONFIG_SCHEDSTATS
2941 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2942#endif
2943#ifdef CONFIG_LATENCYTOP
2944 REG("latency", S_IRUGO, proc_lstats_operations),
2945#endif
2946#ifdef CONFIG_PROC_PID_CPUSET
2947 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2948#endif
2949#ifdef CONFIG_CGROUPS
2950 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2951#endif
2952 INF("oom_score", S_IRUGO, proc_oom_score),
2953 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
2954 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2955#ifdef CONFIG_AUDITSYSCALL
2956 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2957 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2958#endif
2959#ifdef CONFIG_FAULT_INJECTION
2960 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2961#endif
2962#ifdef CONFIG_TASK_IO_ACCOUNTING
2963 INF("io", S_IRUSR, proc_tid_io_accounting),
2964#endif
2965#ifdef CONFIG_HARDWALL
2966 INF("hardwall", S_IRUGO, proc_pid_hardwall),
2967#endif
2968#ifdef CONFIG_USER_NS
2969 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
2970 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
2971 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
2972#endif
2973};
2974
2975static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
2976{
2977 return proc_pident_readdir(file, ctx,
2978 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
2979}
2980
2981static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
2982{
2983 return proc_pident_lookup(dir, dentry,
2984 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
2985}
2986
2987static const struct file_operations proc_tid_base_operations = {
2988 .read = generic_read_dir,
2989 .iterate = proc_tid_base_readdir,
2990 .llseek = default_llseek,
2991};
2992
2993static const struct inode_operations proc_tid_base_inode_operations = {
2994 .lookup = proc_tid_base_lookup,
2995 .getattr = pid_getattr,
2996 .setattr = proc_setattr,
2997};
2998
2999static int proc_task_instantiate(struct inode *dir,
3000 struct dentry *dentry, struct task_struct *task, const void *ptr)
3001{
3002 struct inode *inode;
3003 inode = proc_pid_make_inode(dir->i_sb, task);
3004
3005 if (!inode)
3006 goto out;
3007 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3008 inode->i_op = &proc_tid_base_inode_operations;
3009 inode->i_fop = &proc_tid_base_operations;
3010 inode->i_flags|=S_IMMUTABLE;
3011
3012 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3013 ARRAY_SIZE(tid_base_stuff)));
3014
3015 d_set_d_op(dentry, &pid_dentry_operations);
3016
3017 d_add(dentry, inode);
3018 /* Close the race of the process dying before we return the dentry */
3019 if (pid_revalidate(dentry, 0))
3020 return 0;
3021out:
3022 return -ENOENT;
3023}
3024
3025static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3026{
3027 int result = -ENOENT;
3028 struct task_struct *task;
3029 struct task_struct *leader = get_proc_task(dir);
3030 unsigned tid;
3031 struct pid_namespace *ns;
3032
3033 if (!leader)
3034 goto out_no_task;
3035
3036 tid = name_to_int(dentry);
3037 if (tid == ~0U)
3038 goto out;
3039
3040 ns = dentry->d_sb->s_fs_info;
3041 rcu_read_lock();
3042 task = find_task_by_pid_ns(tid, ns);
3043 if (task)
3044 get_task_struct(task);
3045 rcu_read_unlock();
3046 if (!task)
3047 goto out;
3048 if (!same_thread_group(leader, task))
3049 goto out_drop_task;
3050
3051 result = proc_task_instantiate(dir, dentry, task, NULL);
3052out_drop_task:
3053 put_task_struct(task);
3054out:
3055 put_task_struct(leader);
3056out_no_task:
3057 return ERR_PTR(result);
3058}
3059
3060/*
3061 * Find the first tid of a thread group to return to user space.
3062 *
3063 * Usually this is just the thread group leader, but if the users
3064 * buffer was too small or there was a seek into the middle of the
3065 * directory we have more work todo.
3066 *
3067 * In the case of a short read we start with find_task_by_pid.
3068 *
3069 * In the case of a seek we start with the leader and walk nr
3070 * threads past it.
3071 */
3072static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3073 struct pid_namespace *ns)
3074{
3075 struct task_struct *pos, *task;
3076 unsigned long nr = f_pos;
3077
3078 if (nr != f_pos) /* 32bit overflow? */
3079 return NULL;
3080
3081 rcu_read_lock();
3082 task = pid_task(pid, PIDTYPE_PID);
3083 if (!task)
3084 goto fail;
3085
3086 /* Attempt to start with the tid of a thread */
3087 if (tid && nr) {
3088 pos = find_task_by_pid_ns(tid, ns);
3089 if (pos && same_thread_group(pos, task))
3090 goto found;
3091 }
3092
3093 /* If nr exceeds the number of threads there is nothing todo */
3094 if (nr >= get_nr_threads(task))
3095 goto fail;
3096
3097 /* If we haven't found our starting place yet start
3098 * with the leader and walk nr threads forward.
3099 */
3100 pos = task = task->group_leader;
3101 do {
3102 if (!nr--)
3103 goto found;
3104 } while_each_thread(task, pos);
3105fail:
3106 pos = NULL;
3107 goto out;
3108found:
3109 get_task_struct(pos);
3110out:
3111 rcu_read_unlock();
3112 return pos;
3113}
3114
3115/*
3116 * Find the next thread in the thread list.
3117 * Return NULL if there is an error or no next thread.
3118 *
3119 * The reference to the input task_struct is released.
3120 */
3121static struct task_struct *next_tid(struct task_struct *start)
3122{
3123 struct task_struct *pos = NULL;
3124 rcu_read_lock();
3125 if (pid_alive(start)) {
3126 pos = next_thread(start);
3127 if (thread_group_leader(pos))
3128 pos = NULL;
3129 else
3130 get_task_struct(pos);
3131 }
3132 rcu_read_unlock();
3133 put_task_struct(start);
3134 return pos;
3135}
3136
3137/* for the /proc/TGID/task/ directories */
3138static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3139{
3140 struct inode *inode = file_inode(file);
3141 struct task_struct *task;
3142 struct pid_namespace *ns;
3143 int tid;
3144
3145 if (proc_inode_is_dead(inode))
3146 return -ENOENT;
3147
3148 if (!dir_emit_dots(file, ctx))
3149 return 0;
3150
3151 /* f_version caches the tgid value that the last readdir call couldn't
3152 * return. lseek aka telldir automagically resets f_version to 0.
3153 */
3154 ns = file->f_dentry->d_sb->s_fs_info;
3155 tid = (int)file->f_version;
3156 file->f_version = 0;
3157 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3158 task;
3159 task = next_tid(task), ctx->pos++) {
3160 char name[PROC_NUMBUF];
3161 int len;
3162 tid = task_pid_nr_ns(task, ns);
3163 len = snprintf(name, sizeof(name), "%d", tid);
3164 if (!proc_fill_cache(file, ctx, name, len,
3165 proc_task_instantiate, task, NULL)) {
3166 /* returning this tgid failed, save it as the first
3167 * pid for the next readir call */
3168 file->f_version = (u64)tid;
3169 put_task_struct(task);
3170 break;
3171 }
3172 }
3173
3174 return 0;
3175}
3176
3177static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3178{
3179 struct inode *inode = dentry->d_inode;
3180 struct task_struct *p = get_proc_task(inode);
3181 generic_fillattr(inode, stat);
3182
3183 if (p) {
3184 stat->nlink += get_nr_threads(p);
3185 put_task_struct(p);
3186 }
3187
3188 return 0;
3189}
3190
3191static const struct inode_operations proc_task_inode_operations = {
3192 .lookup = proc_task_lookup,
3193 .getattr = proc_task_getattr,
3194 .setattr = proc_setattr,
3195 .permission = proc_pid_permission,
3196};
3197
3198static const struct file_operations proc_task_operations = {
3199 .read = generic_read_dir,
3200 .iterate = proc_task_readdir,
3201 .llseek = default_llseek,
3202};
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/proc/base.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 * proc base directory handling functions
8 *
9 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
10 * Instead of using magical inumbers to determine the kind of object
11 * we allocate and fill in-core inodes upon lookup. They don't even
12 * go into icache. We cache the reference to task_struct upon lookup too.
13 * Eventually it should become a filesystem in its own. We don't use the
14 * rest of procfs anymore.
15 *
16 *
17 * Changelog:
18 * 17-Jan-2005
19 * Allan Bezerra
20 * Bruna Moreira <bruna.moreira@indt.org.br>
21 * Edjard Mota <edjard.mota@indt.org.br>
22 * Ilias Biris <ilias.biris@indt.org.br>
23 * Mauricio Lin <mauricio.lin@indt.org.br>
24 *
25 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
26 *
27 * A new process specific entry (smaps) included in /proc. It shows the
28 * size of rss for each memory area. The maps entry lacks information
29 * about physical memory size (rss) for each mapped file, i.e.,
30 * rss information for executables and library files.
31 * This additional information is useful for any tools that need to know
32 * about physical memory consumption for a process specific library.
33 *
34 * Changelog:
35 * 21-Feb-2005
36 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
37 * Pud inclusion in the page table walking.
38 *
39 * ChangeLog:
40 * 10-Mar-2005
41 * 10LE Instituto Nokia de Tecnologia - INdT:
42 * A better way to walks through the page table as suggested by Hugh Dickins.
43 *
44 * Simo Piiroinen <simo.piiroinen@nokia.com>:
45 * Smaps information related to shared, private, clean and dirty pages.
46 *
47 * Paul Mundt <paul.mundt@nokia.com>:
48 * Overall revision about smaps.
49 */
50
51#include <linux/uaccess.h>
52
53#include <linux/errno.h>
54#include <linux/time.h>
55#include <linux/proc_fs.h>
56#include <linux/stat.h>
57#include <linux/task_io_accounting_ops.h>
58#include <linux/init.h>
59#include <linux/capability.h>
60#include <linux/file.h>
61#include <linux/fdtable.h>
62#include <linux/generic-radix-tree.h>
63#include <linux/string.h>
64#include <linux/seq_file.h>
65#include <linux/namei.h>
66#include <linux/mnt_namespace.h>
67#include <linux/mm.h>
68#include <linux/swap.h>
69#include <linux/rcupdate.h>
70#include <linux/kallsyms.h>
71#include <linux/stacktrace.h>
72#include <linux/resource.h>
73#include <linux/module.h>
74#include <linux/mount.h>
75#include <linux/security.h>
76#include <linux/ptrace.h>
77#include <linux/printk.h>
78#include <linux/cache.h>
79#include <linux/cgroup.h>
80#include <linux/cpuset.h>
81#include <linux/audit.h>
82#include <linux/poll.h>
83#include <linux/nsproxy.h>
84#include <linux/oom.h>
85#include <linux/elf.h>
86#include <linux/pid_namespace.h>
87#include <linux/user_namespace.h>
88#include <linux/fs_struct.h>
89#include <linux/slab.h>
90#include <linux/sched/autogroup.h>
91#include <linux/sched/mm.h>
92#include <linux/sched/coredump.h>
93#include <linux/sched/debug.h>
94#include <linux/sched/stat.h>
95#include <linux/posix-timers.h>
96#include <linux/time_namespace.h>
97#include <linux/resctrl.h>
98#include <linux/cn_proc.h>
99#include <linux/ksm.h>
100#include <uapi/linux/lsm.h>
101#include <trace/events/oom.h>
102#include "internal.h"
103#include "fd.h"
104
105#include "../../lib/kstrtox.h"
106
107/* NOTE:
108 * Implementing inode permission operations in /proc is almost
109 * certainly an error. Permission checks need to happen during
110 * each system call not at open time. The reason is that most of
111 * what we wish to check for permissions in /proc varies at runtime.
112 *
113 * The classic example of a problem is opening file descriptors
114 * in /proc for a task before it execs a suid executable.
115 */
116
117static u8 nlink_tid __ro_after_init;
118static u8 nlink_tgid __ro_after_init;
119
120struct pid_entry {
121 const char *name;
122 unsigned int len;
123 umode_t mode;
124 const struct inode_operations *iop;
125 const struct file_operations *fop;
126 union proc_op op;
127};
128
129#define NOD(NAME, MODE, IOP, FOP, OP) { \
130 .name = (NAME), \
131 .len = sizeof(NAME) - 1, \
132 .mode = MODE, \
133 .iop = IOP, \
134 .fop = FOP, \
135 .op = OP, \
136}
137
138#define DIR(NAME, MODE, iops, fops) \
139 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
140#define LNK(NAME, get_link) \
141 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
142 &proc_pid_link_inode_operations, NULL, \
143 { .proc_get_link = get_link } )
144#define REG(NAME, MODE, fops) \
145 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
146#define ONE(NAME, MODE, show) \
147 NOD(NAME, (S_IFREG|(MODE)), \
148 NULL, &proc_single_file_operations, \
149 { .proc_show = show } )
150#define ATTR(LSMID, NAME, MODE) \
151 NOD(NAME, (S_IFREG|(MODE)), \
152 NULL, &proc_pid_attr_operations, \
153 { .lsmid = LSMID })
154
155/*
156 * Count the number of hardlinks for the pid_entry table, excluding the .
157 * and .. links.
158 */
159static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
160 unsigned int n)
161{
162 unsigned int i;
163 unsigned int count;
164
165 count = 2;
166 for (i = 0; i < n; ++i) {
167 if (S_ISDIR(entries[i].mode))
168 ++count;
169 }
170
171 return count;
172}
173
174static int get_task_root(struct task_struct *task, struct path *root)
175{
176 int result = -ENOENT;
177
178 task_lock(task);
179 if (task->fs) {
180 get_fs_root(task->fs, root);
181 result = 0;
182 }
183 task_unlock(task);
184 return result;
185}
186
187static int proc_cwd_link(struct dentry *dentry, struct path *path)
188{
189 struct task_struct *task = get_proc_task(d_inode(dentry));
190 int result = -ENOENT;
191
192 if (task) {
193 task_lock(task);
194 if (task->fs) {
195 get_fs_pwd(task->fs, path);
196 result = 0;
197 }
198 task_unlock(task);
199 put_task_struct(task);
200 }
201 return result;
202}
203
204static int proc_root_link(struct dentry *dentry, struct path *path)
205{
206 struct task_struct *task = get_proc_task(d_inode(dentry));
207 int result = -ENOENT;
208
209 if (task) {
210 result = get_task_root(task, path);
211 put_task_struct(task);
212 }
213 return result;
214}
215
216/*
217 * If the user used setproctitle(), we just get the string from
218 * user space at arg_start, and limit it to a maximum of one page.
219 */
220static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf,
221 size_t count, unsigned long pos,
222 unsigned long arg_start)
223{
224 char *page;
225 int ret, got;
226
227 if (pos >= PAGE_SIZE)
228 return 0;
229
230 page = (char *)__get_free_page(GFP_KERNEL);
231 if (!page)
232 return -ENOMEM;
233
234 ret = 0;
235 got = access_remote_vm(mm, arg_start, page, PAGE_SIZE, FOLL_ANON);
236 if (got > 0) {
237 int len = strnlen(page, got);
238
239 /* Include the NUL character if it was found */
240 if (len < got)
241 len++;
242
243 if (len > pos) {
244 len -= pos;
245 if (len > count)
246 len = count;
247 len -= copy_to_user(buf, page+pos, len);
248 if (!len)
249 len = -EFAULT;
250 ret = len;
251 }
252 }
253 free_page((unsigned long)page);
254 return ret;
255}
256
257static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
258 size_t count, loff_t *ppos)
259{
260 unsigned long arg_start, arg_end, env_start, env_end;
261 unsigned long pos, len;
262 char *page, c;
263
264 /* Check if process spawned far enough to have cmdline. */
265 if (!mm->env_end)
266 return 0;
267
268 spin_lock(&mm->arg_lock);
269 arg_start = mm->arg_start;
270 arg_end = mm->arg_end;
271 env_start = mm->env_start;
272 env_end = mm->env_end;
273 spin_unlock(&mm->arg_lock);
274
275 if (arg_start >= arg_end)
276 return 0;
277
278 /*
279 * We allow setproctitle() to overwrite the argument
280 * strings, and overflow past the original end. But
281 * only when it overflows into the environment area.
282 */
283 if (env_start != arg_end || env_end < env_start)
284 env_start = env_end = arg_end;
285 len = env_end - arg_start;
286
287 /* We're not going to care if "*ppos" has high bits set */
288 pos = *ppos;
289 if (pos >= len)
290 return 0;
291 if (count > len - pos)
292 count = len - pos;
293 if (!count)
294 return 0;
295
296 /*
297 * Magical special case: if the argv[] end byte is not
298 * zero, the user has overwritten it with setproctitle(3).
299 *
300 * Possible future enhancement: do this only once when
301 * pos is 0, and set a flag in the 'struct file'.
302 */
303 if (access_remote_vm(mm, arg_end-1, &c, 1, FOLL_ANON) == 1 && c)
304 return get_mm_proctitle(mm, buf, count, pos, arg_start);
305
306 /*
307 * For the non-setproctitle() case we limit things strictly
308 * to the [arg_start, arg_end[ range.
309 */
310 pos += arg_start;
311 if (pos < arg_start || pos >= arg_end)
312 return 0;
313 if (count > arg_end - pos)
314 count = arg_end - pos;
315
316 page = (char *)__get_free_page(GFP_KERNEL);
317 if (!page)
318 return -ENOMEM;
319
320 len = 0;
321 while (count) {
322 int got;
323 size_t size = min_t(size_t, PAGE_SIZE, count);
324
325 got = access_remote_vm(mm, pos, page, size, FOLL_ANON);
326 if (got <= 0)
327 break;
328 got -= copy_to_user(buf, page, got);
329 if (unlikely(!got)) {
330 if (!len)
331 len = -EFAULT;
332 break;
333 }
334 pos += got;
335 buf += got;
336 len += got;
337 count -= got;
338 }
339
340 free_page((unsigned long)page);
341 return len;
342}
343
344static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf,
345 size_t count, loff_t *pos)
346{
347 struct mm_struct *mm;
348 ssize_t ret;
349
350 mm = get_task_mm(tsk);
351 if (!mm)
352 return 0;
353
354 ret = get_mm_cmdline(mm, buf, count, pos);
355 mmput(mm);
356 return ret;
357}
358
359static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
360 size_t count, loff_t *pos)
361{
362 struct task_struct *tsk;
363 ssize_t ret;
364
365 BUG_ON(*pos < 0);
366
367 tsk = get_proc_task(file_inode(file));
368 if (!tsk)
369 return -ESRCH;
370 ret = get_task_cmdline(tsk, buf, count, pos);
371 put_task_struct(tsk);
372 if (ret > 0)
373 *pos += ret;
374 return ret;
375}
376
377static const struct file_operations proc_pid_cmdline_ops = {
378 .read = proc_pid_cmdline_read,
379 .llseek = generic_file_llseek,
380};
381
382#ifdef CONFIG_KALLSYMS
383/*
384 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
385 * Returns the resolved symbol. If that fails, simply return the address.
386 */
387static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
388 struct pid *pid, struct task_struct *task)
389{
390 unsigned long wchan;
391 char symname[KSYM_NAME_LEN];
392
393 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
394 goto print0;
395
396 wchan = get_wchan(task);
397 if (wchan && !lookup_symbol_name(wchan, symname)) {
398 seq_puts(m, symname);
399 return 0;
400 }
401
402print0:
403 seq_putc(m, '0');
404 return 0;
405}
406#endif /* CONFIG_KALLSYMS */
407
408static int lock_trace(struct task_struct *task)
409{
410 int err = down_read_killable(&task->signal->exec_update_lock);
411 if (err)
412 return err;
413 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
414 up_read(&task->signal->exec_update_lock);
415 return -EPERM;
416 }
417 return 0;
418}
419
420static void unlock_trace(struct task_struct *task)
421{
422 up_read(&task->signal->exec_update_lock);
423}
424
425#ifdef CONFIG_STACKTRACE
426
427#define MAX_STACK_TRACE_DEPTH 64
428
429static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
430 struct pid *pid, struct task_struct *task)
431{
432 unsigned long *entries;
433 int err;
434
435 /*
436 * The ability to racily run the kernel stack unwinder on a running task
437 * and then observe the unwinder output is scary; while it is useful for
438 * debugging kernel issues, it can also allow an attacker to leak kernel
439 * stack contents.
440 * Doing this in a manner that is at least safe from races would require
441 * some work to ensure that the remote task can not be scheduled; and
442 * even then, this would still expose the unwinder as local attack
443 * surface.
444 * Therefore, this interface is restricted to root.
445 */
446 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
447 return -EACCES;
448
449 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
450 GFP_KERNEL);
451 if (!entries)
452 return -ENOMEM;
453
454 err = lock_trace(task);
455 if (!err) {
456 unsigned int i, nr_entries;
457
458 nr_entries = stack_trace_save_tsk(task, entries,
459 MAX_STACK_TRACE_DEPTH, 0);
460
461 for (i = 0; i < nr_entries; i++) {
462 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
463 }
464
465 unlock_trace(task);
466 }
467 kfree(entries);
468
469 return err;
470}
471#endif
472
473#ifdef CONFIG_SCHED_INFO
474/*
475 * Provides /proc/PID/schedstat
476 */
477static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
478 struct pid *pid, struct task_struct *task)
479{
480 if (unlikely(!sched_info_on()))
481 seq_puts(m, "0 0 0\n");
482 else
483 seq_printf(m, "%llu %llu %lu\n",
484 (unsigned long long)task->se.sum_exec_runtime,
485 (unsigned long long)task->sched_info.run_delay,
486 task->sched_info.pcount);
487
488 return 0;
489}
490#endif
491
492#ifdef CONFIG_LATENCYTOP
493static int lstats_show_proc(struct seq_file *m, void *v)
494{
495 int i;
496 struct inode *inode = m->private;
497 struct task_struct *task = get_proc_task(inode);
498
499 if (!task)
500 return -ESRCH;
501 seq_puts(m, "Latency Top version : v0.1\n");
502 for (i = 0; i < LT_SAVECOUNT; i++) {
503 struct latency_record *lr = &task->latency_record[i];
504 if (lr->backtrace[0]) {
505 int q;
506 seq_printf(m, "%i %li %li",
507 lr->count, lr->time, lr->max);
508 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
509 unsigned long bt = lr->backtrace[q];
510
511 if (!bt)
512 break;
513 seq_printf(m, " %ps", (void *)bt);
514 }
515 seq_putc(m, '\n');
516 }
517
518 }
519 put_task_struct(task);
520 return 0;
521}
522
523static int lstats_open(struct inode *inode, struct file *file)
524{
525 return single_open(file, lstats_show_proc, inode);
526}
527
528static ssize_t lstats_write(struct file *file, const char __user *buf,
529 size_t count, loff_t *offs)
530{
531 struct task_struct *task = get_proc_task(file_inode(file));
532
533 if (!task)
534 return -ESRCH;
535 clear_tsk_latency_tracing(task);
536 put_task_struct(task);
537
538 return count;
539}
540
541static const struct file_operations proc_lstats_operations = {
542 .open = lstats_open,
543 .read = seq_read,
544 .write = lstats_write,
545 .llseek = seq_lseek,
546 .release = single_release,
547};
548
549#endif
550
551static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
552 struct pid *pid, struct task_struct *task)
553{
554 unsigned long totalpages = totalram_pages() + total_swap_pages;
555 unsigned long points = 0;
556 long badness;
557
558 badness = oom_badness(task, totalpages);
559 /*
560 * Special case OOM_SCORE_ADJ_MIN for all others scale the
561 * badness value into [0, 2000] range which we have been
562 * exporting for a long time so userspace might depend on it.
563 */
564 if (badness != LONG_MIN)
565 points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3;
566
567 seq_printf(m, "%lu\n", points);
568
569 return 0;
570}
571
572struct limit_names {
573 const char *name;
574 const char *unit;
575};
576
577static const struct limit_names lnames[RLIM_NLIMITS] = {
578 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
579 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
580 [RLIMIT_DATA] = {"Max data size", "bytes"},
581 [RLIMIT_STACK] = {"Max stack size", "bytes"},
582 [RLIMIT_CORE] = {"Max core file size", "bytes"},
583 [RLIMIT_RSS] = {"Max resident set", "bytes"},
584 [RLIMIT_NPROC] = {"Max processes", "processes"},
585 [RLIMIT_NOFILE] = {"Max open files", "files"},
586 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
587 [RLIMIT_AS] = {"Max address space", "bytes"},
588 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
589 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
590 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
591 [RLIMIT_NICE] = {"Max nice priority", NULL},
592 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
593 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
594};
595
596/* Display limits for a process */
597static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
598 struct pid *pid, struct task_struct *task)
599{
600 unsigned int i;
601 unsigned long flags;
602
603 struct rlimit rlim[RLIM_NLIMITS];
604
605 if (!lock_task_sighand(task, &flags))
606 return 0;
607 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
608 unlock_task_sighand(task, &flags);
609
610 /*
611 * print the file header
612 */
613 seq_puts(m, "Limit "
614 "Soft Limit "
615 "Hard Limit "
616 "Units \n");
617
618 for (i = 0; i < RLIM_NLIMITS; i++) {
619 if (rlim[i].rlim_cur == RLIM_INFINITY)
620 seq_printf(m, "%-25s %-20s ",
621 lnames[i].name, "unlimited");
622 else
623 seq_printf(m, "%-25s %-20lu ",
624 lnames[i].name, rlim[i].rlim_cur);
625
626 if (rlim[i].rlim_max == RLIM_INFINITY)
627 seq_printf(m, "%-20s ", "unlimited");
628 else
629 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
630
631 if (lnames[i].unit)
632 seq_printf(m, "%-10s\n", lnames[i].unit);
633 else
634 seq_putc(m, '\n');
635 }
636
637 return 0;
638}
639
640#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
641static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
642 struct pid *pid, struct task_struct *task)
643{
644 struct syscall_info info;
645 u64 *args = &info.data.args[0];
646 int res;
647
648 res = lock_trace(task);
649 if (res)
650 return res;
651
652 if (task_current_syscall(task, &info))
653 seq_puts(m, "running\n");
654 else if (info.data.nr < 0)
655 seq_printf(m, "%d 0x%llx 0x%llx\n",
656 info.data.nr, info.sp, info.data.instruction_pointer);
657 else
658 seq_printf(m,
659 "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
660 info.data.nr,
661 args[0], args[1], args[2], args[3], args[4], args[5],
662 info.sp, info.data.instruction_pointer);
663 unlock_trace(task);
664
665 return 0;
666}
667#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
668
669/************************************************************************/
670/* Here the fs part begins */
671/************************************************************************/
672
673/* permission checks */
674static bool proc_fd_access_allowed(struct inode *inode)
675{
676 struct task_struct *task;
677 bool allowed = false;
678 /* Allow access to a task's file descriptors if it is us or we
679 * may use ptrace attach to the process and find out that
680 * information.
681 */
682 task = get_proc_task(inode);
683 if (task) {
684 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
685 put_task_struct(task);
686 }
687 return allowed;
688}
689
690int proc_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
691 struct iattr *attr)
692{
693 int error;
694 struct inode *inode = d_inode(dentry);
695
696 if (attr->ia_valid & ATTR_MODE)
697 return -EPERM;
698
699 error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
700 if (error)
701 return error;
702
703 setattr_copy(&nop_mnt_idmap, inode, attr);
704 return 0;
705}
706
707/*
708 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
709 * or euid/egid (for hide_pid_min=2)?
710 */
711static bool has_pid_permissions(struct proc_fs_info *fs_info,
712 struct task_struct *task,
713 enum proc_hidepid hide_pid_min)
714{
715 /*
716 * If 'hidpid' mount option is set force a ptrace check,
717 * we indicate that we are using a filesystem syscall
718 * by passing PTRACE_MODE_READ_FSCREDS
719 */
720 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE)
721 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
722
723 if (fs_info->hide_pid < hide_pid_min)
724 return true;
725 if (in_group_p(fs_info->pid_gid))
726 return true;
727 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
728}
729
730
731static int proc_pid_permission(struct mnt_idmap *idmap,
732 struct inode *inode, int mask)
733{
734 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
735 struct task_struct *task;
736 bool has_perms;
737
738 task = get_proc_task(inode);
739 if (!task)
740 return -ESRCH;
741 has_perms = has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS);
742 put_task_struct(task);
743
744 if (!has_perms) {
745 if (fs_info->hide_pid == HIDEPID_INVISIBLE) {
746 /*
747 * Let's make getdents(), stat(), and open()
748 * consistent with each other. If a process
749 * may not stat() a file, it shouldn't be seen
750 * in procfs at all.
751 */
752 return -ENOENT;
753 }
754
755 return -EPERM;
756 }
757 return generic_permission(&nop_mnt_idmap, inode, mask);
758}
759
760
761
762static const struct inode_operations proc_def_inode_operations = {
763 .setattr = proc_setattr,
764};
765
766static int proc_single_show(struct seq_file *m, void *v)
767{
768 struct inode *inode = m->private;
769 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
770 struct pid *pid = proc_pid(inode);
771 struct task_struct *task;
772 int ret;
773
774 task = get_pid_task(pid, PIDTYPE_PID);
775 if (!task)
776 return -ESRCH;
777
778 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
779
780 put_task_struct(task);
781 return ret;
782}
783
784static int proc_single_open(struct inode *inode, struct file *filp)
785{
786 return single_open(filp, proc_single_show, inode);
787}
788
789static const struct file_operations proc_single_file_operations = {
790 .open = proc_single_open,
791 .read = seq_read,
792 .llseek = seq_lseek,
793 .release = single_release,
794};
795
796
797struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
798{
799 struct task_struct *task = get_proc_task(inode);
800 struct mm_struct *mm = ERR_PTR(-ESRCH);
801
802 if (task) {
803 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
804 put_task_struct(task);
805
806 if (!IS_ERR_OR_NULL(mm)) {
807 /* ensure this mm_struct can't be freed */
808 mmgrab(mm);
809 /* but do not pin its memory */
810 mmput(mm);
811 }
812 }
813
814 return mm;
815}
816
817static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
818{
819 struct mm_struct *mm = proc_mem_open(inode, mode);
820
821 if (IS_ERR(mm))
822 return PTR_ERR(mm);
823
824 file->private_data = mm;
825 return 0;
826}
827
828static int mem_open(struct inode *inode, struct file *file)
829{
830 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
831
832 /* OK to pass negative loff_t, we can catch out-of-range */
833 file->f_mode |= FMODE_UNSIGNED_OFFSET;
834
835 return ret;
836}
837
838static ssize_t mem_rw(struct file *file, char __user *buf,
839 size_t count, loff_t *ppos, int write)
840{
841 struct mm_struct *mm = file->private_data;
842 unsigned long addr = *ppos;
843 ssize_t copied;
844 char *page;
845 unsigned int flags;
846
847 if (!mm)
848 return 0;
849
850 page = (char *)__get_free_page(GFP_KERNEL);
851 if (!page)
852 return -ENOMEM;
853
854 copied = 0;
855 if (!mmget_not_zero(mm))
856 goto free;
857
858 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
859
860 while (count > 0) {
861 size_t this_len = min_t(size_t, count, PAGE_SIZE);
862
863 if (write && copy_from_user(page, buf, this_len)) {
864 copied = -EFAULT;
865 break;
866 }
867
868 this_len = access_remote_vm(mm, addr, page, this_len, flags);
869 if (!this_len) {
870 if (!copied)
871 copied = -EIO;
872 break;
873 }
874
875 if (!write && copy_to_user(buf, page, this_len)) {
876 copied = -EFAULT;
877 break;
878 }
879
880 buf += this_len;
881 addr += this_len;
882 copied += this_len;
883 count -= this_len;
884 }
885 *ppos = addr;
886
887 mmput(mm);
888free:
889 free_page((unsigned long) page);
890 return copied;
891}
892
893static ssize_t mem_read(struct file *file, char __user *buf,
894 size_t count, loff_t *ppos)
895{
896 return mem_rw(file, buf, count, ppos, 0);
897}
898
899static ssize_t mem_write(struct file *file, const char __user *buf,
900 size_t count, loff_t *ppos)
901{
902 return mem_rw(file, (char __user*)buf, count, ppos, 1);
903}
904
905loff_t mem_lseek(struct file *file, loff_t offset, int orig)
906{
907 switch (orig) {
908 case 0:
909 file->f_pos = offset;
910 break;
911 case 1:
912 file->f_pos += offset;
913 break;
914 default:
915 return -EINVAL;
916 }
917 force_successful_syscall_return();
918 return file->f_pos;
919}
920
921static int mem_release(struct inode *inode, struct file *file)
922{
923 struct mm_struct *mm = file->private_data;
924 if (mm)
925 mmdrop(mm);
926 return 0;
927}
928
929static const struct file_operations proc_mem_operations = {
930 .llseek = mem_lseek,
931 .read = mem_read,
932 .write = mem_write,
933 .open = mem_open,
934 .release = mem_release,
935};
936
937static int environ_open(struct inode *inode, struct file *file)
938{
939 return __mem_open(inode, file, PTRACE_MODE_READ);
940}
941
942static ssize_t environ_read(struct file *file, char __user *buf,
943 size_t count, loff_t *ppos)
944{
945 char *page;
946 unsigned long src = *ppos;
947 int ret = 0;
948 struct mm_struct *mm = file->private_data;
949 unsigned long env_start, env_end;
950
951 /* Ensure the process spawned far enough to have an environment. */
952 if (!mm || !mm->env_end)
953 return 0;
954
955 page = (char *)__get_free_page(GFP_KERNEL);
956 if (!page)
957 return -ENOMEM;
958
959 ret = 0;
960 if (!mmget_not_zero(mm))
961 goto free;
962
963 spin_lock(&mm->arg_lock);
964 env_start = mm->env_start;
965 env_end = mm->env_end;
966 spin_unlock(&mm->arg_lock);
967
968 while (count > 0) {
969 size_t this_len, max_len;
970 int retval;
971
972 if (src >= (env_end - env_start))
973 break;
974
975 this_len = env_end - (env_start + src);
976
977 max_len = min_t(size_t, PAGE_SIZE, count);
978 this_len = min(max_len, this_len);
979
980 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
981
982 if (retval <= 0) {
983 ret = retval;
984 break;
985 }
986
987 if (copy_to_user(buf, page, retval)) {
988 ret = -EFAULT;
989 break;
990 }
991
992 ret += retval;
993 src += retval;
994 buf += retval;
995 count -= retval;
996 }
997 *ppos = src;
998 mmput(mm);
999
1000free:
1001 free_page((unsigned long) page);
1002 return ret;
1003}
1004
1005static const struct file_operations proc_environ_operations = {
1006 .open = environ_open,
1007 .read = environ_read,
1008 .llseek = generic_file_llseek,
1009 .release = mem_release,
1010};
1011
1012static int auxv_open(struct inode *inode, struct file *file)
1013{
1014 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1015}
1016
1017static ssize_t auxv_read(struct file *file, char __user *buf,
1018 size_t count, loff_t *ppos)
1019{
1020 struct mm_struct *mm = file->private_data;
1021 unsigned int nwords = 0;
1022
1023 if (!mm)
1024 return 0;
1025 do {
1026 nwords += 2;
1027 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1028 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1029 nwords * sizeof(mm->saved_auxv[0]));
1030}
1031
1032static const struct file_operations proc_auxv_operations = {
1033 .open = auxv_open,
1034 .read = auxv_read,
1035 .llseek = generic_file_llseek,
1036 .release = mem_release,
1037};
1038
1039static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1040 loff_t *ppos)
1041{
1042 struct task_struct *task = get_proc_task(file_inode(file));
1043 char buffer[PROC_NUMBUF];
1044 int oom_adj = OOM_ADJUST_MIN;
1045 size_t len;
1046
1047 if (!task)
1048 return -ESRCH;
1049 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1050 oom_adj = OOM_ADJUST_MAX;
1051 else
1052 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1053 OOM_SCORE_ADJ_MAX;
1054 put_task_struct(task);
1055 if (oom_adj > OOM_ADJUST_MAX)
1056 oom_adj = OOM_ADJUST_MAX;
1057 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1058 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1059}
1060
1061static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1062{
1063 struct mm_struct *mm = NULL;
1064 struct task_struct *task;
1065 int err = 0;
1066
1067 task = get_proc_task(file_inode(file));
1068 if (!task)
1069 return -ESRCH;
1070
1071 mutex_lock(&oom_adj_mutex);
1072 if (legacy) {
1073 if (oom_adj < task->signal->oom_score_adj &&
1074 !capable(CAP_SYS_RESOURCE)) {
1075 err = -EACCES;
1076 goto err_unlock;
1077 }
1078 /*
1079 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1080 * /proc/pid/oom_score_adj instead.
1081 */
1082 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1083 current->comm, task_pid_nr(current), task_pid_nr(task),
1084 task_pid_nr(task));
1085 } else {
1086 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1087 !capable(CAP_SYS_RESOURCE)) {
1088 err = -EACCES;
1089 goto err_unlock;
1090 }
1091 }
1092
1093 /*
1094 * Make sure we will check other processes sharing the mm if this is
1095 * not vfrok which wants its own oom_score_adj.
1096 * pin the mm so it doesn't go away and get reused after task_unlock
1097 */
1098 if (!task->vfork_done) {
1099 struct task_struct *p = find_lock_task_mm(task);
1100
1101 if (p) {
1102 if (test_bit(MMF_MULTIPROCESS, &p->mm->flags)) {
1103 mm = p->mm;
1104 mmgrab(mm);
1105 }
1106 task_unlock(p);
1107 }
1108 }
1109
1110 task->signal->oom_score_adj = oom_adj;
1111 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1112 task->signal->oom_score_adj_min = (short)oom_adj;
1113 trace_oom_score_adj_update(task);
1114
1115 if (mm) {
1116 struct task_struct *p;
1117
1118 rcu_read_lock();
1119 for_each_process(p) {
1120 if (same_thread_group(task, p))
1121 continue;
1122
1123 /* do not touch kernel threads or the global init */
1124 if (p->flags & PF_KTHREAD || is_global_init(p))
1125 continue;
1126
1127 task_lock(p);
1128 if (!p->vfork_done && process_shares_mm(p, mm)) {
1129 p->signal->oom_score_adj = oom_adj;
1130 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1131 p->signal->oom_score_adj_min = (short)oom_adj;
1132 }
1133 task_unlock(p);
1134 }
1135 rcu_read_unlock();
1136 mmdrop(mm);
1137 }
1138err_unlock:
1139 mutex_unlock(&oom_adj_mutex);
1140 put_task_struct(task);
1141 return err;
1142}
1143
1144/*
1145 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1146 * kernels. The effective policy is defined by oom_score_adj, which has a
1147 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1148 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1149 * Processes that become oom disabled via oom_adj will still be oom disabled
1150 * with this implementation.
1151 *
1152 * oom_adj cannot be removed since existing userspace binaries use it.
1153 */
1154static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1155 size_t count, loff_t *ppos)
1156{
1157 char buffer[PROC_NUMBUF] = {};
1158 int oom_adj;
1159 int err;
1160
1161 if (count > sizeof(buffer) - 1)
1162 count = sizeof(buffer) - 1;
1163 if (copy_from_user(buffer, buf, count)) {
1164 err = -EFAULT;
1165 goto out;
1166 }
1167
1168 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1169 if (err)
1170 goto out;
1171 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1172 oom_adj != OOM_DISABLE) {
1173 err = -EINVAL;
1174 goto out;
1175 }
1176
1177 /*
1178 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1179 * value is always attainable.
1180 */
1181 if (oom_adj == OOM_ADJUST_MAX)
1182 oom_adj = OOM_SCORE_ADJ_MAX;
1183 else
1184 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1185
1186 err = __set_oom_adj(file, oom_adj, true);
1187out:
1188 return err < 0 ? err : count;
1189}
1190
1191static const struct file_operations proc_oom_adj_operations = {
1192 .read = oom_adj_read,
1193 .write = oom_adj_write,
1194 .llseek = generic_file_llseek,
1195};
1196
1197static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1198 size_t count, loff_t *ppos)
1199{
1200 struct task_struct *task = get_proc_task(file_inode(file));
1201 char buffer[PROC_NUMBUF];
1202 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1203 size_t len;
1204
1205 if (!task)
1206 return -ESRCH;
1207 oom_score_adj = task->signal->oom_score_adj;
1208 put_task_struct(task);
1209 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1210 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1211}
1212
1213static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1214 size_t count, loff_t *ppos)
1215{
1216 char buffer[PROC_NUMBUF] = {};
1217 int oom_score_adj;
1218 int err;
1219
1220 if (count > sizeof(buffer) - 1)
1221 count = sizeof(buffer) - 1;
1222 if (copy_from_user(buffer, buf, count)) {
1223 err = -EFAULT;
1224 goto out;
1225 }
1226
1227 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1228 if (err)
1229 goto out;
1230 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1231 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1232 err = -EINVAL;
1233 goto out;
1234 }
1235
1236 err = __set_oom_adj(file, oom_score_adj, false);
1237out:
1238 return err < 0 ? err : count;
1239}
1240
1241static const struct file_operations proc_oom_score_adj_operations = {
1242 .read = oom_score_adj_read,
1243 .write = oom_score_adj_write,
1244 .llseek = default_llseek,
1245};
1246
1247#ifdef CONFIG_AUDIT
1248#define TMPBUFLEN 11
1249static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1250 size_t count, loff_t *ppos)
1251{
1252 struct inode * inode = file_inode(file);
1253 struct task_struct *task = get_proc_task(inode);
1254 ssize_t length;
1255 char tmpbuf[TMPBUFLEN];
1256
1257 if (!task)
1258 return -ESRCH;
1259 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1260 from_kuid(file->f_cred->user_ns,
1261 audit_get_loginuid(task)));
1262 put_task_struct(task);
1263 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1264}
1265
1266static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1267 size_t count, loff_t *ppos)
1268{
1269 struct inode * inode = file_inode(file);
1270 uid_t loginuid;
1271 kuid_t kloginuid;
1272 int rv;
1273
1274 /* Don't let kthreads write their own loginuid */
1275 if (current->flags & PF_KTHREAD)
1276 return -EPERM;
1277
1278 rcu_read_lock();
1279 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1280 rcu_read_unlock();
1281 return -EPERM;
1282 }
1283 rcu_read_unlock();
1284
1285 if (*ppos != 0) {
1286 /* No partial writes. */
1287 return -EINVAL;
1288 }
1289
1290 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1291 if (rv < 0)
1292 return rv;
1293
1294 /* is userspace tring to explicitly UNSET the loginuid? */
1295 if (loginuid == AUDIT_UID_UNSET) {
1296 kloginuid = INVALID_UID;
1297 } else {
1298 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1299 if (!uid_valid(kloginuid))
1300 return -EINVAL;
1301 }
1302
1303 rv = audit_set_loginuid(kloginuid);
1304 if (rv < 0)
1305 return rv;
1306 return count;
1307}
1308
1309static const struct file_operations proc_loginuid_operations = {
1310 .read = proc_loginuid_read,
1311 .write = proc_loginuid_write,
1312 .llseek = generic_file_llseek,
1313};
1314
1315static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1316 size_t count, loff_t *ppos)
1317{
1318 struct inode * inode = file_inode(file);
1319 struct task_struct *task = get_proc_task(inode);
1320 ssize_t length;
1321 char tmpbuf[TMPBUFLEN];
1322
1323 if (!task)
1324 return -ESRCH;
1325 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1326 audit_get_sessionid(task));
1327 put_task_struct(task);
1328 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1329}
1330
1331static const struct file_operations proc_sessionid_operations = {
1332 .read = proc_sessionid_read,
1333 .llseek = generic_file_llseek,
1334};
1335#endif
1336
1337#ifdef CONFIG_FAULT_INJECTION
1338static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1339 size_t count, loff_t *ppos)
1340{
1341 struct task_struct *task = get_proc_task(file_inode(file));
1342 char buffer[PROC_NUMBUF];
1343 size_t len;
1344 int make_it_fail;
1345
1346 if (!task)
1347 return -ESRCH;
1348 make_it_fail = task->make_it_fail;
1349 put_task_struct(task);
1350
1351 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1352
1353 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1354}
1355
1356static ssize_t proc_fault_inject_write(struct file * file,
1357 const char __user * buf, size_t count, loff_t *ppos)
1358{
1359 struct task_struct *task;
1360 char buffer[PROC_NUMBUF] = {};
1361 int make_it_fail;
1362 int rv;
1363
1364 if (!capable(CAP_SYS_RESOURCE))
1365 return -EPERM;
1366
1367 if (count > sizeof(buffer) - 1)
1368 count = sizeof(buffer) - 1;
1369 if (copy_from_user(buffer, buf, count))
1370 return -EFAULT;
1371 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1372 if (rv < 0)
1373 return rv;
1374 if (make_it_fail < 0 || make_it_fail > 1)
1375 return -EINVAL;
1376
1377 task = get_proc_task(file_inode(file));
1378 if (!task)
1379 return -ESRCH;
1380 task->make_it_fail = make_it_fail;
1381 put_task_struct(task);
1382
1383 return count;
1384}
1385
1386static const struct file_operations proc_fault_inject_operations = {
1387 .read = proc_fault_inject_read,
1388 .write = proc_fault_inject_write,
1389 .llseek = generic_file_llseek,
1390};
1391
1392static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1393 size_t count, loff_t *ppos)
1394{
1395 struct task_struct *task;
1396 int err;
1397 unsigned int n;
1398
1399 err = kstrtouint_from_user(buf, count, 0, &n);
1400 if (err)
1401 return err;
1402
1403 task = get_proc_task(file_inode(file));
1404 if (!task)
1405 return -ESRCH;
1406 task->fail_nth = n;
1407 put_task_struct(task);
1408
1409 return count;
1410}
1411
1412static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1413 size_t count, loff_t *ppos)
1414{
1415 struct task_struct *task;
1416 char numbuf[PROC_NUMBUF];
1417 ssize_t len;
1418
1419 task = get_proc_task(file_inode(file));
1420 if (!task)
1421 return -ESRCH;
1422 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1423 put_task_struct(task);
1424 return simple_read_from_buffer(buf, count, ppos, numbuf, len);
1425}
1426
1427static const struct file_operations proc_fail_nth_operations = {
1428 .read = proc_fail_nth_read,
1429 .write = proc_fail_nth_write,
1430};
1431#endif
1432
1433
1434#ifdef CONFIG_SCHED_DEBUG
1435/*
1436 * Print out various scheduling related per-task fields:
1437 */
1438static int sched_show(struct seq_file *m, void *v)
1439{
1440 struct inode *inode = m->private;
1441 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
1442 struct task_struct *p;
1443
1444 p = get_proc_task(inode);
1445 if (!p)
1446 return -ESRCH;
1447 proc_sched_show_task(p, ns, m);
1448
1449 put_task_struct(p);
1450
1451 return 0;
1452}
1453
1454static ssize_t
1455sched_write(struct file *file, const char __user *buf,
1456 size_t count, loff_t *offset)
1457{
1458 struct inode *inode = file_inode(file);
1459 struct task_struct *p;
1460
1461 p = get_proc_task(inode);
1462 if (!p)
1463 return -ESRCH;
1464 proc_sched_set_task(p);
1465
1466 put_task_struct(p);
1467
1468 return count;
1469}
1470
1471static int sched_open(struct inode *inode, struct file *filp)
1472{
1473 return single_open(filp, sched_show, inode);
1474}
1475
1476static const struct file_operations proc_pid_sched_operations = {
1477 .open = sched_open,
1478 .read = seq_read,
1479 .write = sched_write,
1480 .llseek = seq_lseek,
1481 .release = single_release,
1482};
1483
1484#endif
1485
1486#ifdef CONFIG_SCHED_AUTOGROUP
1487/*
1488 * Print out autogroup related information:
1489 */
1490static int sched_autogroup_show(struct seq_file *m, void *v)
1491{
1492 struct inode *inode = m->private;
1493 struct task_struct *p;
1494
1495 p = get_proc_task(inode);
1496 if (!p)
1497 return -ESRCH;
1498 proc_sched_autogroup_show_task(p, m);
1499
1500 put_task_struct(p);
1501
1502 return 0;
1503}
1504
1505static ssize_t
1506sched_autogroup_write(struct file *file, const char __user *buf,
1507 size_t count, loff_t *offset)
1508{
1509 struct inode *inode = file_inode(file);
1510 struct task_struct *p;
1511 char buffer[PROC_NUMBUF] = {};
1512 int nice;
1513 int err;
1514
1515 if (count > sizeof(buffer) - 1)
1516 count = sizeof(buffer) - 1;
1517 if (copy_from_user(buffer, buf, count))
1518 return -EFAULT;
1519
1520 err = kstrtoint(strstrip(buffer), 0, &nice);
1521 if (err < 0)
1522 return err;
1523
1524 p = get_proc_task(inode);
1525 if (!p)
1526 return -ESRCH;
1527
1528 err = proc_sched_autogroup_set_nice(p, nice);
1529 if (err)
1530 count = err;
1531
1532 put_task_struct(p);
1533
1534 return count;
1535}
1536
1537static int sched_autogroup_open(struct inode *inode, struct file *filp)
1538{
1539 int ret;
1540
1541 ret = single_open(filp, sched_autogroup_show, NULL);
1542 if (!ret) {
1543 struct seq_file *m = filp->private_data;
1544
1545 m->private = inode;
1546 }
1547 return ret;
1548}
1549
1550static const struct file_operations proc_pid_sched_autogroup_operations = {
1551 .open = sched_autogroup_open,
1552 .read = seq_read,
1553 .write = sched_autogroup_write,
1554 .llseek = seq_lseek,
1555 .release = single_release,
1556};
1557
1558#endif /* CONFIG_SCHED_AUTOGROUP */
1559
1560#ifdef CONFIG_TIME_NS
1561static int timens_offsets_show(struct seq_file *m, void *v)
1562{
1563 struct task_struct *p;
1564
1565 p = get_proc_task(file_inode(m->file));
1566 if (!p)
1567 return -ESRCH;
1568 proc_timens_show_offsets(p, m);
1569
1570 put_task_struct(p);
1571
1572 return 0;
1573}
1574
1575static ssize_t timens_offsets_write(struct file *file, const char __user *buf,
1576 size_t count, loff_t *ppos)
1577{
1578 struct inode *inode = file_inode(file);
1579 struct proc_timens_offset offsets[2];
1580 char *kbuf = NULL, *pos, *next_line;
1581 struct task_struct *p;
1582 int ret, noffsets;
1583
1584 /* Only allow < page size writes at the beginning of the file */
1585 if ((*ppos != 0) || (count >= PAGE_SIZE))
1586 return -EINVAL;
1587
1588 /* Slurp in the user data */
1589 kbuf = memdup_user_nul(buf, count);
1590 if (IS_ERR(kbuf))
1591 return PTR_ERR(kbuf);
1592
1593 /* Parse the user data */
1594 ret = -EINVAL;
1595 noffsets = 0;
1596 for (pos = kbuf; pos; pos = next_line) {
1597 struct proc_timens_offset *off = &offsets[noffsets];
1598 char clock[10];
1599 int err;
1600
1601 /* Find the end of line and ensure we don't look past it */
1602 next_line = strchr(pos, '\n');
1603 if (next_line) {
1604 *next_line = '\0';
1605 next_line++;
1606 if (*next_line == '\0')
1607 next_line = NULL;
1608 }
1609
1610 err = sscanf(pos, "%9s %lld %lu", clock,
1611 &off->val.tv_sec, &off->val.tv_nsec);
1612 if (err != 3 || off->val.tv_nsec >= NSEC_PER_SEC)
1613 goto out;
1614
1615 clock[sizeof(clock) - 1] = 0;
1616 if (strcmp(clock, "monotonic") == 0 ||
1617 strcmp(clock, __stringify(CLOCK_MONOTONIC)) == 0)
1618 off->clockid = CLOCK_MONOTONIC;
1619 else if (strcmp(clock, "boottime") == 0 ||
1620 strcmp(clock, __stringify(CLOCK_BOOTTIME)) == 0)
1621 off->clockid = CLOCK_BOOTTIME;
1622 else
1623 goto out;
1624
1625 noffsets++;
1626 if (noffsets == ARRAY_SIZE(offsets)) {
1627 if (next_line)
1628 count = next_line - kbuf;
1629 break;
1630 }
1631 }
1632
1633 ret = -ESRCH;
1634 p = get_proc_task(inode);
1635 if (!p)
1636 goto out;
1637 ret = proc_timens_set_offset(file, p, offsets, noffsets);
1638 put_task_struct(p);
1639 if (ret)
1640 goto out;
1641
1642 ret = count;
1643out:
1644 kfree(kbuf);
1645 return ret;
1646}
1647
1648static int timens_offsets_open(struct inode *inode, struct file *filp)
1649{
1650 return single_open(filp, timens_offsets_show, inode);
1651}
1652
1653static const struct file_operations proc_timens_offsets_operations = {
1654 .open = timens_offsets_open,
1655 .read = seq_read,
1656 .write = timens_offsets_write,
1657 .llseek = seq_lseek,
1658 .release = single_release,
1659};
1660#endif /* CONFIG_TIME_NS */
1661
1662static ssize_t comm_write(struct file *file, const char __user *buf,
1663 size_t count, loff_t *offset)
1664{
1665 struct inode *inode = file_inode(file);
1666 struct task_struct *p;
1667 char buffer[TASK_COMM_LEN] = {};
1668 const size_t maxlen = sizeof(buffer) - 1;
1669
1670 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1671 return -EFAULT;
1672
1673 p = get_proc_task(inode);
1674 if (!p)
1675 return -ESRCH;
1676
1677 if (same_thread_group(current, p)) {
1678 set_task_comm(p, buffer);
1679 proc_comm_connector(p);
1680 }
1681 else
1682 count = -EINVAL;
1683
1684 put_task_struct(p);
1685
1686 return count;
1687}
1688
1689static int comm_show(struct seq_file *m, void *v)
1690{
1691 struct inode *inode = m->private;
1692 struct task_struct *p;
1693
1694 p = get_proc_task(inode);
1695 if (!p)
1696 return -ESRCH;
1697
1698 proc_task_name(m, p, false);
1699 seq_putc(m, '\n');
1700
1701 put_task_struct(p);
1702
1703 return 0;
1704}
1705
1706static int comm_open(struct inode *inode, struct file *filp)
1707{
1708 return single_open(filp, comm_show, inode);
1709}
1710
1711static const struct file_operations proc_pid_set_comm_operations = {
1712 .open = comm_open,
1713 .read = seq_read,
1714 .write = comm_write,
1715 .llseek = seq_lseek,
1716 .release = single_release,
1717};
1718
1719static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1720{
1721 struct task_struct *task;
1722 struct file *exe_file;
1723
1724 task = get_proc_task(d_inode(dentry));
1725 if (!task)
1726 return -ENOENT;
1727 exe_file = get_task_exe_file(task);
1728 put_task_struct(task);
1729 if (exe_file) {
1730 *exe_path = exe_file->f_path;
1731 path_get(&exe_file->f_path);
1732 fput(exe_file);
1733 return 0;
1734 } else
1735 return -ENOENT;
1736}
1737
1738static const char *proc_pid_get_link(struct dentry *dentry,
1739 struct inode *inode,
1740 struct delayed_call *done)
1741{
1742 struct path path;
1743 int error = -EACCES;
1744
1745 if (!dentry)
1746 return ERR_PTR(-ECHILD);
1747
1748 /* Are we allowed to snoop on the tasks file descriptors? */
1749 if (!proc_fd_access_allowed(inode))
1750 goto out;
1751
1752 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1753 if (error)
1754 goto out;
1755
1756 error = nd_jump_link(&path);
1757out:
1758 return ERR_PTR(error);
1759}
1760
1761static int do_proc_readlink(const struct path *path, char __user *buffer, int buflen)
1762{
1763 char *tmp = kmalloc(PATH_MAX, GFP_KERNEL);
1764 char *pathname;
1765 int len;
1766
1767 if (!tmp)
1768 return -ENOMEM;
1769
1770 pathname = d_path(path, tmp, PATH_MAX);
1771 len = PTR_ERR(pathname);
1772 if (IS_ERR(pathname))
1773 goto out;
1774 len = tmp + PATH_MAX - 1 - pathname;
1775
1776 if (len > buflen)
1777 len = buflen;
1778 if (copy_to_user(buffer, pathname, len))
1779 len = -EFAULT;
1780 out:
1781 kfree(tmp);
1782 return len;
1783}
1784
1785static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1786{
1787 int error = -EACCES;
1788 struct inode *inode = d_inode(dentry);
1789 struct path path;
1790
1791 /* Are we allowed to snoop on the tasks file descriptors? */
1792 if (!proc_fd_access_allowed(inode))
1793 goto out;
1794
1795 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1796 if (error)
1797 goto out;
1798
1799 error = do_proc_readlink(&path, buffer, buflen);
1800 path_put(&path);
1801out:
1802 return error;
1803}
1804
1805const struct inode_operations proc_pid_link_inode_operations = {
1806 .readlink = proc_pid_readlink,
1807 .get_link = proc_pid_get_link,
1808 .setattr = proc_setattr,
1809};
1810
1811
1812/* building an inode */
1813
1814void task_dump_owner(struct task_struct *task, umode_t mode,
1815 kuid_t *ruid, kgid_t *rgid)
1816{
1817 /* Depending on the state of dumpable compute who should own a
1818 * proc file for a task.
1819 */
1820 const struct cred *cred;
1821 kuid_t uid;
1822 kgid_t gid;
1823
1824 if (unlikely(task->flags & PF_KTHREAD)) {
1825 *ruid = GLOBAL_ROOT_UID;
1826 *rgid = GLOBAL_ROOT_GID;
1827 return;
1828 }
1829
1830 /* Default to the tasks effective ownership */
1831 rcu_read_lock();
1832 cred = __task_cred(task);
1833 uid = cred->euid;
1834 gid = cred->egid;
1835 rcu_read_unlock();
1836
1837 /*
1838 * Before the /proc/pid/status file was created the only way to read
1839 * the effective uid of a /process was to stat /proc/pid. Reading
1840 * /proc/pid/status is slow enough that procps and other packages
1841 * kept stating /proc/pid. To keep the rules in /proc simple I have
1842 * made this apply to all per process world readable and executable
1843 * directories.
1844 */
1845 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1846 struct mm_struct *mm;
1847 task_lock(task);
1848 mm = task->mm;
1849 /* Make non-dumpable tasks owned by some root */
1850 if (mm) {
1851 if (get_dumpable(mm) != SUID_DUMP_USER) {
1852 struct user_namespace *user_ns = mm->user_ns;
1853
1854 uid = make_kuid(user_ns, 0);
1855 if (!uid_valid(uid))
1856 uid = GLOBAL_ROOT_UID;
1857
1858 gid = make_kgid(user_ns, 0);
1859 if (!gid_valid(gid))
1860 gid = GLOBAL_ROOT_GID;
1861 }
1862 } else {
1863 uid = GLOBAL_ROOT_UID;
1864 gid = GLOBAL_ROOT_GID;
1865 }
1866 task_unlock(task);
1867 }
1868 *ruid = uid;
1869 *rgid = gid;
1870}
1871
1872void proc_pid_evict_inode(struct proc_inode *ei)
1873{
1874 struct pid *pid = ei->pid;
1875
1876 if (S_ISDIR(ei->vfs_inode.i_mode)) {
1877 spin_lock(&pid->lock);
1878 hlist_del_init_rcu(&ei->sibling_inodes);
1879 spin_unlock(&pid->lock);
1880 }
1881}
1882
1883struct inode *proc_pid_make_inode(struct super_block *sb,
1884 struct task_struct *task, umode_t mode)
1885{
1886 struct inode * inode;
1887 struct proc_inode *ei;
1888 struct pid *pid;
1889
1890 /* We need a new inode */
1891
1892 inode = new_inode(sb);
1893 if (!inode)
1894 goto out;
1895
1896 /* Common stuff */
1897 ei = PROC_I(inode);
1898 inode->i_mode = mode;
1899 inode->i_ino = get_next_ino();
1900 simple_inode_init_ts(inode);
1901 inode->i_op = &proc_def_inode_operations;
1902
1903 /*
1904 * grab the reference to task.
1905 */
1906 pid = get_task_pid(task, PIDTYPE_PID);
1907 if (!pid)
1908 goto out_unlock;
1909
1910 /* Let the pid remember us for quick removal */
1911 ei->pid = pid;
1912
1913 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1914 security_task_to_inode(task, inode);
1915
1916out:
1917 return inode;
1918
1919out_unlock:
1920 iput(inode);
1921 return NULL;
1922}
1923
1924/*
1925 * Generating an inode and adding it into @pid->inodes, so that task will
1926 * invalidate inode's dentry before being released.
1927 *
1928 * This helper is used for creating dir-type entries under '/proc' and
1929 * '/proc/<tgid>/task'. Other entries(eg. fd, stat) under '/proc/<tgid>'
1930 * can be released by invalidating '/proc/<tgid>' dentry.
1931 * In theory, dentries under '/proc/<tgid>/task' can also be released by
1932 * invalidating '/proc/<tgid>' dentry, we reserve it to handle single
1933 * thread exiting situation: Any one of threads should invalidate its
1934 * '/proc/<tgid>/task/<pid>' dentry before released.
1935 */
1936static struct inode *proc_pid_make_base_inode(struct super_block *sb,
1937 struct task_struct *task, umode_t mode)
1938{
1939 struct inode *inode;
1940 struct proc_inode *ei;
1941 struct pid *pid;
1942
1943 inode = proc_pid_make_inode(sb, task, mode);
1944 if (!inode)
1945 return NULL;
1946
1947 /* Let proc_flush_pid find this directory inode */
1948 ei = PROC_I(inode);
1949 pid = ei->pid;
1950 spin_lock(&pid->lock);
1951 hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes);
1952 spin_unlock(&pid->lock);
1953
1954 return inode;
1955}
1956
1957int pid_getattr(struct mnt_idmap *idmap, const struct path *path,
1958 struct kstat *stat, u32 request_mask, unsigned int query_flags)
1959{
1960 struct inode *inode = d_inode(path->dentry);
1961 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
1962 struct task_struct *task;
1963
1964 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
1965
1966 stat->uid = GLOBAL_ROOT_UID;
1967 stat->gid = GLOBAL_ROOT_GID;
1968 rcu_read_lock();
1969 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1970 if (task) {
1971 if (!has_pid_permissions(fs_info, task, HIDEPID_INVISIBLE)) {
1972 rcu_read_unlock();
1973 /*
1974 * This doesn't prevent learning whether PID exists,
1975 * it only makes getattr() consistent with readdir().
1976 */
1977 return -ENOENT;
1978 }
1979 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1980 }
1981 rcu_read_unlock();
1982 return 0;
1983}
1984
1985/* dentry stuff */
1986
1987/*
1988 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
1989 */
1990void pid_update_inode(struct task_struct *task, struct inode *inode)
1991{
1992 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1993
1994 inode->i_mode &= ~(S_ISUID | S_ISGID);
1995 security_task_to_inode(task, inode);
1996}
1997
1998/*
1999 * Rewrite the inode's ownerships here because the owning task may have
2000 * performed a setuid(), etc.
2001 *
2002 */
2003static int pid_revalidate(struct dentry *dentry, unsigned int flags)
2004{
2005 struct inode *inode;
2006 struct task_struct *task;
2007 int ret = 0;
2008
2009 rcu_read_lock();
2010 inode = d_inode_rcu(dentry);
2011 if (!inode)
2012 goto out;
2013 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2014
2015 if (task) {
2016 pid_update_inode(task, inode);
2017 ret = 1;
2018 }
2019out:
2020 rcu_read_unlock();
2021 return ret;
2022}
2023
2024static inline bool proc_inode_is_dead(struct inode *inode)
2025{
2026 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
2027}
2028
2029int pid_delete_dentry(const struct dentry *dentry)
2030{
2031 /* Is the task we represent dead?
2032 * If so, then don't put the dentry on the lru list,
2033 * kill it immediately.
2034 */
2035 return proc_inode_is_dead(d_inode(dentry));
2036}
2037
2038const struct dentry_operations pid_dentry_operations =
2039{
2040 .d_revalidate = pid_revalidate,
2041 .d_delete = pid_delete_dentry,
2042};
2043
2044/* Lookups */
2045
2046/*
2047 * Fill a directory entry.
2048 *
2049 * If possible create the dcache entry and derive our inode number and
2050 * file type from dcache entry.
2051 *
2052 * Since all of the proc inode numbers are dynamically generated, the inode
2053 * numbers do not exist until the inode is cache. This means creating
2054 * the dcache entry in readdir is necessary to keep the inode numbers
2055 * reported by readdir in sync with the inode numbers reported
2056 * by stat.
2057 */
2058bool proc_fill_cache(struct file *file, struct dir_context *ctx,
2059 const char *name, unsigned int len,
2060 instantiate_t instantiate, struct task_struct *task, const void *ptr)
2061{
2062 struct dentry *child, *dir = file->f_path.dentry;
2063 struct qstr qname = QSTR_INIT(name, len);
2064 struct inode *inode;
2065 unsigned type = DT_UNKNOWN;
2066 ino_t ino = 1;
2067
2068 child = d_hash_and_lookup(dir, &qname);
2069 if (!child) {
2070 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
2071 child = d_alloc_parallel(dir, &qname, &wq);
2072 if (IS_ERR(child))
2073 goto end_instantiate;
2074 if (d_in_lookup(child)) {
2075 struct dentry *res;
2076 res = instantiate(child, task, ptr);
2077 d_lookup_done(child);
2078 if (unlikely(res)) {
2079 dput(child);
2080 child = res;
2081 if (IS_ERR(child))
2082 goto end_instantiate;
2083 }
2084 }
2085 }
2086 inode = d_inode(child);
2087 ino = inode->i_ino;
2088 type = inode->i_mode >> 12;
2089 dput(child);
2090end_instantiate:
2091 return dir_emit(ctx, name, len, ino, type);
2092}
2093
2094/*
2095 * dname_to_vma_addr - maps a dentry name into two unsigned longs
2096 * which represent vma start and end addresses.
2097 */
2098static int dname_to_vma_addr(struct dentry *dentry,
2099 unsigned long *start, unsigned long *end)
2100{
2101 const char *str = dentry->d_name.name;
2102 unsigned long long sval, eval;
2103 unsigned int len;
2104
2105 if (str[0] == '0' && str[1] != '-')
2106 return -EINVAL;
2107 len = _parse_integer(str, 16, &sval);
2108 if (len & KSTRTOX_OVERFLOW)
2109 return -EINVAL;
2110 if (sval != (unsigned long)sval)
2111 return -EINVAL;
2112 str += len;
2113
2114 if (*str != '-')
2115 return -EINVAL;
2116 str++;
2117
2118 if (str[0] == '0' && str[1])
2119 return -EINVAL;
2120 len = _parse_integer(str, 16, &eval);
2121 if (len & KSTRTOX_OVERFLOW)
2122 return -EINVAL;
2123 if (eval != (unsigned long)eval)
2124 return -EINVAL;
2125 str += len;
2126
2127 if (*str != '\0')
2128 return -EINVAL;
2129
2130 *start = sval;
2131 *end = eval;
2132
2133 return 0;
2134}
2135
2136static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
2137{
2138 unsigned long vm_start, vm_end;
2139 bool exact_vma_exists = false;
2140 struct mm_struct *mm = NULL;
2141 struct task_struct *task;
2142 struct inode *inode;
2143 int status = 0;
2144
2145 if (flags & LOOKUP_RCU)
2146 return -ECHILD;
2147
2148 inode = d_inode(dentry);
2149 task = get_proc_task(inode);
2150 if (!task)
2151 goto out_notask;
2152
2153 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
2154 if (IS_ERR_OR_NULL(mm))
2155 goto out;
2156
2157 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2158 status = mmap_read_lock_killable(mm);
2159 if (!status) {
2160 exact_vma_exists = !!find_exact_vma(mm, vm_start,
2161 vm_end);
2162 mmap_read_unlock(mm);
2163 }
2164 }
2165
2166 mmput(mm);
2167
2168 if (exact_vma_exists) {
2169 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
2170
2171 security_task_to_inode(task, inode);
2172 status = 1;
2173 }
2174
2175out:
2176 put_task_struct(task);
2177
2178out_notask:
2179 return status;
2180}
2181
2182static const struct dentry_operations tid_map_files_dentry_operations = {
2183 .d_revalidate = map_files_d_revalidate,
2184 .d_delete = pid_delete_dentry,
2185};
2186
2187static int map_files_get_link(struct dentry *dentry, struct path *path)
2188{
2189 unsigned long vm_start, vm_end;
2190 struct vm_area_struct *vma;
2191 struct task_struct *task;
2192 struct mm_struct *mm;
2193 int rc;
2194
2195 rc = -ENOENT;
2196 task = get_proc_task(d_inode(dentry));
2197 if (!task)
2198 goto out;
2199
2200 mm = get_task_mm(task);
2201 put_task_struct(task);
2202 if (!mm)
2203 goto out;
2204
2205 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2206 if (rc)
2207 goto out_mmput;
2208
2209 rc = mmap_read_lock_killable(mm);
2210 if (rc)
2211 goto out_mmput;
2212
2213 rc = -ENOENT;
2214 vma = find_exact_vma(mm, vm_start, vm_end);
2215 if (vma && vma->vm_file) {
2216 *path = *file_user_path(vma->vm_file);
2217 path_get(path);
2218 rc = 0;
2219 }
2220 mmap_read_unlock(mm);
2221
2222out_mmput:
2223 mmput(mm);
2224out:
2225 return rc;
2226}
2227
2228struct map_files_info {
2229 unsigned long start;
2230 unsigned long end;
2231 fmode_t mode;
2232};
2233
2234/*
2235 * Only allow CAP_SYS_ADMIN and CAP_CHECKPOINT_RESTORE to follow the links, due
2236 * to concerns about how the symlinks may be used to bypass permissions on
2237 * ancestor directories in the path to the file in question.
2238 */
2239static const char *
2240proc_map_files_get_link(struct dentry *dentry,
2241 struct inode *inode,
2242 struct delayed_call *done)
2243{
2244 if (!checkpoint_restore_ns_capable(&init_user_ns))
2245 return ERR_PTR(-EPERM);
2246
2247 return proc_pid_get_link(dentry, inode, done);
2248}
2249
2250/*
2251 * Identical to proc_pid_link_inode_operations except for get_link()
2252 */
2253static const struct inode_operations proc_map_files_link_inode_operations = {
2254 .readlink = proc_pid_readlink,
2255 .get_link = proc_map_files_get_link,
2256 .setattr = proc_setattr,
2257};
2258
2259static struct dentry *
2260proc_map_files_instantiate(struct dentry *dentry,
2261 struct task_struct *task, const void *ptr)
2262{
2263 fmode_t mode = (fmode_t)(unsigned long)ptr;
2264 struct proc_inode *ei;
2265 struct inode *inode;
2266
2267 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
2268 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2269 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2270 if (!inode)
2271 return ERR_PTR(-ENOENT);
2272
2273 ei = PROC_I(inode);
2274 ei->op.proc_get_link = map_files_get_link;
2275
2276 inode->i_op = &proc_map_files_link_inode_operations;
2277 inode->i_size = 64;
2278
2279 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2280 return d_splice_alias(inode, dentry);
2281}
2282
2283static struct dentry *proc_map_files_lookup(struct inode *dir,
2284 struct dentry *dentry, unsigned int flags)
2285{
2286 unsigned long vm_start, vm_end;
2287 struct vm_area_struct *vma;
2288 struct task_struct *task;
2289 struct dentry *result;
2290 struct mm_struct *mm;
2291
2292 result = ERR_PTR(-ENOENT);
2293 task = get_proc_task(dir);
2294 if (!task)
2295 goto out;
2296
2297 result = ERR_PTR(-EACCES);
2298 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2299 goto out_put_task;
2300
2301 result = ERR_PTR(-ENOENT);
2302 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2303 goto out_put_task;
2304
2305 mm = get_task_mm(task);
2306 if (!mm)
2307 goto out_put_task;
2308
2309 result = ERR_PTR(-EINTR);
2310 if (mmap_read_lock_killable(mm))
2311 goto out_put_mm;
2312
2313 result = ERR_PTR(-ENOENT);
2314 vma = find_exact_vma(mm, vm_start, vm_end);
2315 if (!vma)
2316 goto out_no_vma;
2317
2318 if (vma->vm_file)
2319 result = proc_map_files_instantiate(dentry, task,
2320 (void *)(unsigned long)vma->vm_file->f_mode);
2321
2322out_no_vma:
2323 mmap_read_unlock(mm);
2324out_put_mm:
2325 mmput(mm);
2326out_put_task:
2327 put_task_struct(task);
2328out:
2329 return result;
2330}
2331
2332static const struct inode_operations proc_map_files_inode_operations = {
2333 .lookup = proc_map_files_lookup,
2334 .permission = proc_fd_permission,
2335 .setattr = proc_setattr,
2336};
2337
2338static int
2339proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2340{
2341 struct vm_area_struct *vma;
2342 struct task_struct *task;
2343 struct mm_struct *mm;
2344 unsigned long nr_files, pos, i;
2345 GENRADIX(struct map_files_info) fa;
2346 struct map_files_info *p;
2347 int ret;
2348 struct vma_iterator vmi;
2349
2350 genradix_init(&fa);
2351
2352 ret = -ENOENT;
2353 task = get_proc_task(file_inode(file));
2354 if (!task)
2355 goto out;
2356
2357 ret = -EACCES;
2358 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2359 goto out_put_task;
2360
2361 ret = 0;
2362 if (!dir_emit_dots(file, ctx))
2363 goto out_put_task;
2364
2365 mm = get_task_mm(task);
2366 if (!mm)
2367 goto out_put_task;
2368
2369 ret = mmap_read_lock_killable(mm);
2370 if (ret) {
2371 mmput(mm);
2372 goto out_put_task;
2373 }
2374
2375 nr_files = 0;
2376
2377 /*
2378 * We need two passes here:
2379 *
2380 * 1) Collect vmas of mapped files with mmap_lock taken
2381 * 2) Release mmap_lock and instantiate entries
2382 *
2383 * otherwise we get lockdep complained, since filldir()
2384 * routine might require mmap_lock taken in might_fault().
2385 */
2386
2387 pos = 2;
2388 vma_iter_init(&vmi, mm, 0);
2389 for_each_vma(vmi, vma) {
2390 if (!vma->vm_file)
2391 continue;
2392 if (++pos <= ctx->pos)
2393 continue;
2394
2395 p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
2396 if (!p) {
2397 ret = -ENOMEM;
2398 mmap_read_unlock(mm);
2399 mmput(mm);
2400 goto out_put_task;
2401 }
2402
2403 p->start = vma->vm_start;
2404 p->end = vma->vm_end;
2405 p->mode = vma->vm_file->f_mode;
2406 }
2407 mmap_read_unlock(mm);
2408 mmput(mm);
2409
2410 for (i = 0; i < nr_files; i++) {
2411 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2412 unsigned int len;
2413
2414 p = genradix_ptr(&fa, i);
2415 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2416 if (!proc_fill_cache(file, ctx,
2417 buf, len,
2418 proc_map_files_instantiate,
2419 task,
2420 (void *)(unsigned long)p->mode))
2421 break;
2422 ctx->pos++;
2423 }
2424
2425out_put_task:
2426 put_task_struct(task);
2427out:
2428 genradix_free(&fa);
2429 return ret;
2430}
2431
2432static const struct file_operations proc_map_files_operations = {
2433 .read = generic_read_dir,
2434 .iterate_shared = proc_map_files_readdir,
2435 .llseek = generic_file_llseek,
2436};
2437
2438#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2439struct timers_private {
2440 struct pid *pid;
2441 struct task_struct *task;
2442 struct sighand_struct *sighand;
2443 struct pid_namespace *ns;
2444 unsigned long flags;
2445};
2446
2447static void *timers_start(struct seq_file *m, loff_t *pos)
2448{
2449 struct timers_private *tp = m->private;
2450
2451 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2452 if (!tp->task)
2453 return ERR_PTR(-ESRCH);
2454
2455 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2456 if (!tp->sighand)
2457 return ERR_PTR(-ESRCH);
2458
2459 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2460}
2461
2462static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2463{
2464 struct timers_private *tp = m->private;
2465 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2466}
2467
2468static void timers_stop(struct seq_file *m, void *v)
2469{
2470 struct timers_private *tp = m->private;
2471
2472 if (tp->sighand) {
2473 unlock_task_sighand(tp->task, &tp->flags);
2474 tp->sighand = NULL;
2475 }
2476
2477 if (tp->task) {
2478 put_task_struct(tp->task);
2479 tp->task = NULL;
2480 }
2481}
2482
2483static int show_timer(struct seq_file *m, void *v)
2484{
2485 struct k_itimer *timer;
2486 struct timers_private *tp = m->private;
2487 int notify;
2488 static const char * const nstr[] = {
2489 [SIGEV_SIGNAL] = "signal",
2490 [SIGEV_NONE] = "none",
2491 [SIGEV_THREAD] = "thread",
2492 };
2493
2494 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2495 notify = timer->it_sigev_notify;
2496
2497 seq_printf(m, "ID: %d\n", timer->it_id);
2498 seq_printf(m, "signal: %d/%px\n",
2499 timer->sigq->info.si_signo,
2500 timer->sigq->info.si_value.sival_ptr);
2501 seq_printf(m, "notify: %s/%s.%d\n",
2502 nstr[notify & ~SIGEV_THREAD_ID],
2503 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2504 pid_nr_ns(timer->it_pid, tp->ns));
2505 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2506
2507 return 0;
2508}
2509
2510static const struct seq_operations proc_timers_seq_ops = {
2511 .start = timers_start,
2512 .next = timers_next,
2513 .stop = timers_stop,
2514 .show = show_timer,
2515};
2516
2517static int proc_timers_open(struct inode *inode, struct file *file)
2518{
2519 struct timers_private *tp;
2520
2521 tp = __seq_open_private(file, &proc_timers_seq_ops,
2522 sizeof(struct timers_private));
2523 if (!tp)
2524 return -ENOMEM;
2525
2526 tp->pid = proc_pid(inode);
2527 tp->ns = proc_pid_ns(inode->i_sb);
2528 return 0;
2529}
2530
2531static const struct file_operations proc_timers_operations = {
2532 .open = proc_timers_open,
2533 .read = seq_read,
2534 .llseek = seq_lseek,
2535 .release = seq_release_private,
2536};
2537#endif
2538
2539static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2540 size_t count, loff_t *offset)
2541{
2542 struct inode *inode = file_inode(file);
2543 struct task_struct *p;
2544 u64 slack_ns;
2545 int err;
2546
2547 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2548 if (err < 0)
2549 return err;
2550
2551 p = get_proc_task(inode);
2552 if (!p)
2553 return -ESRCH;
2554
2555 if (p != current) {
2556 rcu_read_lock();
2557 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2558 rcu_read_unlock();
2559 count = -EPERM;
2560 goto out;
2561 }
2562 rcu_read_unlock();
2563
2564 err = security_task_setscheduler(p);
2565 if (err) {
2566 count = err;
2567 goto out;
2568 }
2569 }
2570
2571 task_lock(p);
2572 if (slack_ns == 0)
2573 p->timer_slack_ns = p->default_timer_slack_ns;
2574 else
2575 p->timer_slack_ns = slack_ns;
2576 task_unlock(p);
2577
2578out:
2579 put_task_struct(p);
2580
2581 return count;
2582}
2583
2584static int timerslack_ns_show(struct seq_file *m, void *v)
2585{
2586 struct inode *inode = m->private;
2587 struct task_struct *p;
2588 int err = 0;
2589
2590 p = get_proc_task(inode);
2591 if (!p)
2592 return -ESRCH;
2593
2594 if (p != current) {
2595 rcu_read_lock();
2596 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2597 rcu_read_unlock();
2598 err = -EPERM;
2599 goto out;
2600 }
2601 rcu_read_unlock();
2602
2603 err = security_task_getscheduler(p);
2604 if (err)
2605 goto out;
2606 }
2607
2608 task_lock(p);
2609 seq_printf(m, "%llu\n", p->timer_slack_ns);
2610 task_unlock(p);
2611
2612out:
2613 put_task_struct(p);
2614
2615 return err;
2616}
2617
2618static int timerslack_ns_open(struct inode *inode, struct file *filp)
2619{
2620 return single_open(filp, timerslack_ns_show, inode);
2621}
2622
2623static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2624 .open = timerslack_ns_open,
2625 .read = seq_read,
2626 .write = timerslack_ns_write,
2627 .llseek = seq_lseek,
2628 .release = single_release,
2629};
2630
2631static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2632 struct task_struct *task, const void *ptr)
2633{
2634 const struct pid_entry *p = ptr;
2635 struct inode *inode;
2636 struct proc_inode *ei;
2637
2638 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
2639 if (!inode)
2640 return ERR_PTR(-ENOENT);
2641
2642 ei = PROC_I(inode);
2643 if (S_ISDIR(inode->i_mode))
2644 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2645 if (p->iop)
2646 inode->i_op = p->iop;
2647 if (p->fop)
2648 inode->i_fop = p->fop;
2649 ei->op = p->op;
2650 pid_update_inode(task, inode);
2651 d_set_d_op(dentry, &pid_dentry_operations);
2652 return d_splice_alias(inode, dentry);
2653}
2654
2655static struct dentry *proc_pident_lookup(struct inode *dir,
2656 struct dentry *dentry,
2657 const struct pid_entry *p,
2658 const struct pid_entry *end)
2659{
2660 struct task_struct *task = get_proc_task(dir);
2661 struct dentry *res = ERR_PTR(-ENOENT);
2662
2663 if (!task)
2664 goto out_no_task;
2665
2666 /*
2667 * Yes, it does not scale. And it should not. Don't add
2668 * new entries into /proc/<tgid>/ without very good reasons.
2669 */
2670 for (; p < end; p++) {
2671 if (p->len != dentry->d_name.len)
2672 continue;
2673 if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2674 res = proc_pident_instantiate(dentry, task, p);
2675 break;
2676 }
2677 }
2678 put_task_struct(task);
2679out_no_task:
2680 return res;
2681}
2682
2683static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2684 const struct pid_entry *ents, unsigned int nents)
2685{
2686 struct task_struct *task = get_proc_task(file_inode(file));
2687 const struct pid_entry *p;
2688
2689 if (!task)
2690 return -ENOENT;
2691
2692 if (!dir_emit_dots(file, ctx))
2693 goto out;
2694
2695 if (ctx->pos >= nents + 2)
2696 goto out;
2697
2698 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2699 if (!proc_fill_cache(file, ctx, p->name, p->len,
2700 proc_pident_instantiate, task, p))
2701 break;
2702 ctx->pos++;
2703 }
2704out:
2705 put_task_struct(task);
2706 return 0;
2707}
2708
2709#ifdef CONFIG_SECURITY
2710static int proc_pid_attr_open(struct inode *inode, struct file *file)
2711{
2712 file->private_data = NULL;
2713 __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
2714 return 0;
2715}
2716
2717static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2718 size_t count, loff_t *ppos)
2719{
2720 struct inode * inode = file_inode(file);
2721 char *p = NULL;
2722 ssize_t length;
2723 struct task_struct *task = get_proc_task(inode);
2724
2725 if (!task)
2726 return -ESRCH;
2727
2728 length = security_getprocattr(task, PROC_I(inode)->op.lsmid,
2729 file->f_path.dentry->d_name.name,
2730 &p);
2731 put_task_struct(task);
2732 if (length > 0)
2733 length = simple_read_from_buffer(buf, count, ppos, p, length);
2734 kfree(p);
2735 return length;
2736}
2737
2738static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2739 size_t count, loff_t *ppos)
2740{
2741 struct inode * inode = file_inode(file);
2742 struct task_struct *task;
2743 void *page;
2744 int rv;
2745
2746 /* A task may only write when it was the opener. */
2747 if (file->private_data != current->mm)
2748 return -EPERM;
2749
2750 rcu_read_lock();
2751 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2752 if (!task) {
2753 rcu_read_unlock();
2754 return -ESRCH;
2755 }
2756 /* A task may only write its own attributes. */
2757 if (current != task) {
2758 rcu_read_unlock();
2759 return -EACCES;
2760 }
2761 /* Prevent changes to overridden credentials. */
2762 if (current_cred() != current_real_cred()) {
2763 rcu_read_unlock();
2764 return -EBUSY;
2765 }
2766 rcu_read_unlock();
2767
2768 if (count > PAGE_SIZE)
2769 count = PAGE_SIZE;
2770
2771 /* No partial writes. */
2772 if (*ppos != 0)
2773 return -EINVAL;
2774
2775 page = memdup_user(buf, count);
2776 if (IS_ERR(page)) {
2777 rv = PTR_ERR(page);
2778 goto out;
2779 }
2780
2781 /* Guard against adverse ptrace interaction */
2782 rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex);
2783 if (rv < 0)
2784 goto out_free;
2785
2786 rv = security_setprocattr(PROC_I(inode)->op.lsmid,
2787 file->f_path.dentry->d_name.name, page,
2788 count);
2789 mutex_unlock(¤t->signal->cred_guard_mutex);
2790out_free:
2791 kfree(page);
2792out:
2793 return rv;
2794}
2795
2796static const struct file_operations proc_pid_attr_operations = {
2797 .open = proc_pid_attr_open,
2798 .read = proc_pid_attr_read,
2799 .write = proc_pid_attr_write,
2800 .llseek = generic_file_llseek,
2801 .release = mem_release,
2802};
2803
2804#define LSM_DIR_OPS(LSM) \
2805static int proc_##LSM##_attr_dir_iterate(struct file *filp, \
2806 struct dir_context *ctx) \
2807{ \
2808 return proc_pident_readdir(filp, ctx, \
2809 LSM##_attr_dir_stuff, \
2810 ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2811} \
2812\
2813static const struct file_operations proc_##LSM##_attr_dir_ops = { \
2814 .read = generic_read_dir, \
2815 .iterate_shared = proc_##LSM##_attr_dir_iterate, \
2816 .llseek = default_llseek, \
2817}; \
2818\
2819static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
2820 struct dentry *dentry, unsigned int flags) \
2821{ \
2822 return proc_pident_lookup(dir, dentry, \
2823 LSM##_attr_dir_stuff, \
2824 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2825} \
2826\
2827static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
2828 .lookup = proc_##LSM##_attr_dir_lookup, \
2829 .getattr = pid_getattr, \
2830 .setattr = proc_setattr, \
2831}
2832
2833#ifdef CONFIG_SECURITY_SMACK
2834static const struct pid_entry smack_attr_dir_stuff[] = {
2835 ATTR(LSM_ID_SMACK, "current", 0666),
2836};
2837LSM_DIR_OPS(smack);
2838#endif
2839
2840#ifdef CONFIG_SECURITY_APPARMOR
2841static const struct pid_entry apparmor_attr_dir_stuff[] = {
2842 ATTR(LSM_ID_APPARMOR, "current", 0666),
2843 ATTR(LSM_ID_APPARMOR, "prev", 0444),
2844 ATTR(LSM_ID_APPARMOR, "exec", 0666),
2845};
2846LSM_DIR_OPS(apparmor);
2847#endif
2848
2849static const struct pid_entry attr_dir_stuff[] = {
2850 ATTR(LSM_ID_UNDEF, "current", 0666),
2851 ATTR(LSM_ID_UNDEF, "prev", 0444),
2852 ATTR(LSM_ID_UNDEF, "exec", 0666),
2853 ATTR(LSM_ID_UNDEF, "fscreate", 0666),
2854 ATTR(LSM_ID_UNDEF, "keycreate", 0666),
2855 ATTR(LSM_ID_UNDEF, "sockcreate", 0666),
2856#ifdef CONFIG_SECURITY_SMACK
2857 DIR("smack", 0555,
2858 proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
2859#endif
2860#ifdef CONFIG_SECURITY_APPARMOR
2861 DIR("apparmor", 0555,
2862 proc_apparmor_attr_dir_inode_ops, proc_apparmor_attr_dir_ops),
2863#endif
2864};
2865
2866static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2867{
2868 return proc_pident_readdir(file, ctx,
2869 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2870}
2871
2872static const struct file_operations proc_attr_dir_operations = {
2873 .read = generic_read_dir,
2874 .iterate_shared = proc_attr_dir_readdir,
2875 .llseek = generic_file_llseek,
2876};
2877
2878static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2879 struct dentry *dentry, unsigned int flags)
2880{
2881 return proc_pident_lookup(dir, dentry,
2882 attr_dir_stuff,
2883 attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
2884}
2885
2886static const struct inode_operations proc_attr_dir_inode_operations = {
2887 .lookup = proc_attr_dir_lookup,
2888 .getattr = pid_getattr,
2889 .setattr = proc_setattr,
2890};
2891
2892#endif
2893
2894#ifdef CONFIG_ELF_CORE
2895static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2896 size_t count, loff_t *ppos)
2897{
2898 struct task_struct *task = get_proc_task(file_inode(file));
2899 struct mm_struct *mm;
2900 char buffer[PROC_NUMBUF];
2901 size_t len;
2902 int ret;
2903
2904 if (!task)
2905 return -ESRCH;
2906
2907 ret = 0;
2908 mm = get_task_mm(task);
2909 if (mm) {
2910 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2911 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2912 MMF_DUMP_FILTER_SHIFT));
2913 mmput(mm);
2914 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2915 }
2916
2917 put_task_struct(task);
2918
2919 return ret;
2920}
2921
2922static ssize_t proc_coredump_filter_write(struct file *file,
2923 const char __user *buf,
2924 size_t count,
2925 loff_t *ppos)
2926{
2927 struct task_struct *task;
2928 struct mm_struct *mm;
2929 unsigned int val;
2930 int ret;
2931 int i;
2932 unsigned long mask;
2933
2934 ret = kstrtouint_from_user(buf, count, 0, &val);
2935 if (ret < 0)
2936 return ret;
2937
2938 ret = -ESRCH;
2939 task = get_proc_task(file_inode(file));
2940 if (!task)
2941 goto out_no_task;
2942
2943 mm = get_task_mm(task);
2944 if (!mm)
2945 goto out_no_mm;
2946 ret = 0;
2947
2948 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2949 if (val & mask)
2950 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2951 else
2952 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2953 }
2954
2955 mmput(mm);
2956 out_no_mm:
2957 put_task_struct(task);
2958 out_no_task:
2959 if (ret < 0)
2960 return ret;
2961 return count;
2962}
2963
2964static const struct file_operations proc_coredump_filter_operations = {
2965 .read = proc_coredump_filter_read,
2966 .write = proc_coredump_filter_write,
2967 .llseek = generic_file_llseek,
2968};
2969#endif
2970
2971#ifdef CONFIG_TASK_IO_ACCOUNTING
2972static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2973{
2974 struct task_io_accounting acct;
2975 int result;
2976
2977 result = down_read_killable(&task->signal->exec_update_lock);
2978 if (result)
2979 return result;
2980
2981 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2982 result = -EACCES;
2983 goto out_unlock;
2984 }
2985
2986 if (whole) {
2987 struct signal_struct *sig = task->signal;
2988 struct task_struct *t;
2989 unsigned int seq = 1;
2990 unsigned long flags;
2991
2992 rcu_read_lock();
2993 do {
2994 seq++; /* 2 on the 1st/lockless path, otherwise odd */
2995 flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq);
2996
2997 acct = sig->ioac;
2998 __for_each_thread(sig, t)
2999 task_io_accounting_add(&acct, &t->ioac);
3000
3001 } while (need_seqretry(&sig->stats_lock, seq));
3002 done_seqretry_irqrestore(&sig->stats_lock, seq, flags);
3003 rcu_read_unlock();
3004 } else {
3005 acct = task->ioac;
3006 }
3007
3008 seq_printf(m,
3009 "rchar: %llu\n"
3010 "wchar: %llu\n"
3011 "syscr: %llu\n"
3012 "syscw: %llu\n"
3013 "read_bytes: %llu\n"
3014 "write_bytes: %llu\n"
3015 "cancelled_write_bytes: %llu\n",
3016 (unsigned long long)acct.rchar,
3017 (unsigned long long)acct.wchar,
3018 (unsigned long long)acct.syscr,
3019 (unsigned long long)acct.syscw,
3020 (unsigned long long)acct.read_bytes,
3021 (unsigned long long)acct.write_bytes,
3022 (unsigned long long)acct.cancelled_write_bytes);
3023 result = 0;
3024
3025out_unlock:
3026 up_read(&task->signal->exec_update_lock);
3027 return result;
3028}
3029
3030static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
3031 struct pid *pid, struct task_struct *task)
3032{
3033 return do_io_accounting(task, m, 0);
3034}
3035
3036static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
3037 struct pid *pid, struct task_struct *task)
3038{
3039 return do_io_accounting(task, m, 1);
3040}
3041#endif /* CONFIG_TASK_IO_ACCOUNTING */
3042
3043#ifdef CONFIG_USER_NS
3044static int proc_id_map_open(struct inode *inode, struct file *file,
3045 const struct seq_operations *seq_ops)
3046{
3047 struct user_namespace *ns = NULL;
3048 struct task_struct *task;
3049 struct seq_file *seq;
3050 int ret = -EINVAL;
3051
3052 task = get_proc_task(inode);
3053 if (task) {
3054 rcu_read_lock();
3055 ns = get_user_ns(task_cred_xxx(task, user_ns));
3056 rcu_read_unlock();
3057 put_task_struct(task);
3058 }
3059 if (!ns)
3060 goto err;
3061
3062 ret = seq_open(file, seq_ops);
3063 if (ret)
3064 goto err_put_ns;
3065
3066 seq = file->private_data;
3067 seq->private = ns;
3068
3069 return 0;
3070err_put_ns:
3071 put_user_ns(ns);
3072err:
3073 return ret;
3074}
3075
3076static int proc_id_map_release(struct inode *inode, struct file *file)
3077{
3078 struct seq_file *seq = file->private_data;
3079 struct user_namespace *ns = seq->private;
3080 put_user_ns(ns);
3081 return seq_release(inode, file);
3082}
3083
3084static int proc_uid_map_open(struct inode *inode, struct file *file)
3085{
3086 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
3087}
3088
3089static int proc_gid_map_open(struct inode *inode, struct file *file)
3090{
3091 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
3092}
3093
3094static int proc_projid_map_open(struct inode *inode, struct file *file)
3095{
3096 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
3097}
3098
3099static const struct file_operations proc_uid_map_operations = {
3100 .open = proc_uid_map_open,
3101 .write = proc_uid_map_write,
3102 .read = seq_read,
3103 .llseek = seq_lseek,
3104 .release = proc_id_map_release,
3105};
3106
3107static const struct file_operations proc_gid_map_operations = {
3108 .open = proc_gid_map_open,
3109 .write = proc_gid_map_write,
3110 .read = seq_read,
3111 .llseek = seq_lseek,
3112 .release = proc_id_map_release,
3113};
3114
3115static const struct file_operations proc_projid_map_operations = {
3116 .open = proc_projid_map_open,
3117 .write = proc_projid_map_write,
3118 .read = seq_read,
3119 .llseek = seq_lseek,
3120 .release = proc_id_map_release,
3121};
3122
3123static int proc_setgroups_open(struct inode *inode, struct file *file)
3124{
3125 struct user_namespace *ns = NULL;
3126 struct task_struct *task;
3127 int ret;
3128
3129 ret = -ESRCH;
3130 task = get_proc_task(inode);
3131 if (task) {
3132 rcu_read_lock();
3133 ns = get_user_ns(task_cred_xxx(task, user_ns));
3134 rcu_read_unlock();
3135 put_task_struct(task);
3136 }
3137 if (!ns)
3138 goto err;
3139
3140 if (file->f_mode & FMODE_WRITE) {
3141 ret = -EACCES;
3142 if (!ns_capable(ns, CAP_SYS_ADMIN))
3143 goto err_put_ns;
3144 }
3145
3146 ret = single_open(file, &proc_setgroups_show, ns);
3147 if (ret)
3148 goto err_put_ns;
3149
3150 return 0;
3151err_put_ns:
3152 put_user_ns(ns);
3153err:
3154 return ret;
3155}
3156
3157static int proc_setgroups_release(struct inode *inode, struct file *file)
3158{
3159 struct seq_file *seq = file->private_data;
3160 struct user_namespace *ns = seq->private;
3161 int ret = single_release(inode, file);
3162 put_user_ns(ns);
3163 return ret;
3164}
3165
3166static const struct file_operations proc_setgroups_operations = {
3167 .open = proc_setgroups_open,
3168 .write = proc_setgroups_write,
3169 .read = seq_read,
3170 .llseek = seq_lseek,
3171 .release = proc_setgroups_release,
3172};
3173#endif /* CONFIG_USER_NS */
3174
3175static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
3176 struct pid *pid, struct task_struct *task)
3177{
3178 int err = lock_trace(task);
3179 if (!err) {
3180 seq_printf(m, "%08x\n", task->personality);
3181 unlock_trace(task);
3182 }
3183 return err;
3184}
3185
3186#ifdef CONFIG_LIVEPATCH
3187static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
3188 struct pid *pid, struct task_struct *task)
3189{
3190 seq_printf(m, "%d\n", task->patch_state);
3191 return 0;
3192}
3193#endif /* CONFIG_LIVEPATCH */
3194
3195#ifdef CONFIG_KSM
3196static int proc_pid_ksm_merging_pages(struct seq_file *m, struct pid_namespace *ns,
3197 struct pid *pid, struct task_struct *task)
3198{
3199 struct mm_struct *mm;
3200
3201 mm = get_task_mm(task);
3202 if (mm) {
3203 seq_printf(m, "%lu\n", mm->ksm_merging_pages);
3204 mmput(mm);
3205 }
3206
3207 return 0;
3208}
3209static int proc_pid_ksm_stat(struct seq_file *m, struct pid_namespace *ns,
3210 struct pid *pid, struct task_struct *task)
3211{
3212 struct mm_struct *mm;
3213
3214 mm = get_task_mm(task);
3215 if (mm) {
3216 seq_printf(m, "ksm_rmap_items %lu\n", mm->ksm_rmap_items);
3217 seq_printf(m, "ksm_zero_pages %lu\n", mm->ksm_zero_pages);
3218 seq_printf(m, "ksm_merging_pages %lu\n", mm->ksm_merging_pages);
3219 seq_printf(m, "ksm_process_profit %ld\n", ksm_process_profit(mm));
3220 mmput(mm);
3221 }
3222
3223 return 0;
3224}
3225#endif /* CONFIG_KSM */
3226
3227#ifdef CONFIG_STACKLEAK_METRICS
3228static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
3229 struct pid *pid, struct task_struct *task)
3230{
3231 unsigned long prev_depth = THREAD_SIZE -
3232 (task->prev_lowest_stack & (THREAD_SIZE - 1));
3233 unsigned long depth = THREAD_SIZE -
3234 (task->lowest_stack & (THREAD_SIZE - 1));
3235
3236 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
3237 prev_depth, depth);
3238 return 0;
3239}
3240#endif /* CONFIG_STACKLEAK_METRICS */
3241
3242/*
3243 * Thread groups
3244 */
3245static const struct file_operations proc_task_operations;
3246static const struct inode_operations proc_task_inode_operations;
3247
3248static const struct pid_entry tgid_base_stuff[] = {
3249 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3250 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3251 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3252 DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3253 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3254#ifdef CONFIG_NET
3255 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3256#endif
3257 REG("environ", S_IRUSR, proc_environ_operations),
3258 REG("auxv", S_IRUSR, proc_auxv_operations),
3259 ONE("status", S_IRUGO, proc_pid_status),
3260 ONE("personality", S_IRUSR, proc_pid_personality),
3261 ONE("limits", S_IRUGO, proc_pid_limits),
3262#ifdef CONFIG_SCHED_DEBUG
3263 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3264#endif
3265#ifdef CONFIG_SCHED_AUTOGROUP
3266 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3267#endif
3268#ifdef CONFIG_TIME_NS
3269 REG("timens_offsets", S_IRUGO|S_IWUSR, proc_timens_offsets_operations),
3270#endif
3271 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3272#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3273 ONE("syscall", S_IRUSR, proc_pid_syscall),
3274#endif
3275 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3276 ONE("stat", S_IRUGO, proc_tgid_stat),
3277 ONE("statm", S_IRUGO, proc_pid_statm),
3278 REG("maps", S_IRUGO, proc_pid_maps_operations),
3279#ifdef CONFIG_NUMA
3280 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3281#endif
3282 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3283 LNK("cwd", proc_cwd_link),
3284 LNK("root", proc_root_link),
3285 LNK("exe", proc_exe_link),
3286 REG("mounts", S_IRUGO, proc_mounts_operations),
3287 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3288 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3289#ifdef CONFIG_PROC_PAGE_MONITOR
3290 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3291 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3292 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3293 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3294#endif
3295#ifdef CONFIG_SECURITY
3296 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3297#endif
3298#ifdef CONFIG_KALLSYMS
3299 ONE("wchan", S_IRUGO, proc_pid_wchan),
3300#endif
3301#ifdef CONFIG_STACKTRACE
3302 ONE("stack", S_IRUSR, proc_pid_stack),
3303#endif
3304#ifdef CONFIG_SCHED_INFO
3305 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3306#endif
3307#ifdef CONFIG_LATENCYTOP
3308 REG("latency", S_IRUGO, proc_lstats_operations),
3309#endif
3310#ifdef CONFIG_PROC_PID_CPUSET
3311 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3312#endif
3313#ifdef CONFIG_CGROUPS
3314 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3315#endif
3316#ifdef CONFIG_PROC_CPU_RESCTRL
3317 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3318#endif
3319 ONE("oom_score", S_IRUGO, proc_oom_score),
3320 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3321 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3322#ifdef CONFIG_AUDIT
3323 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3324 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3325#endif
3326#ifdef CONFIG_FAULT_INJECTION
3327 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3328 REG("fail-nth", 0644, proc_fail_nth_operations),
3329#endif
3330#ifdef CONFIG_ELF_CORE
3331 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3332#endif
3333#ifdef CONFIG_TASK_IO_ACCOUNTING
3334 ONE("io", S_IRUSR, proc_tgid_io_accounting),
3335#endif
3336#ifdef CONFIG_USER_NS
3337 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3338 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3339 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3340 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3341#endif
3342#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3343 REG("timers", S_IRUGO, proc_timers_operations),
3344#endif
3345 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3346#ifdef CONFIG_LIVEPATCH
3347 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3348#endif
3349#ifdef CONFIG_STACKLEAK_METRICS
3350 ONE("stack_depth", S_IRUGO, proc_stack_depth),
3351#endif
3352#ifdef CONFIG_PROC_PID_ARCH_STATUS
3353 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3354#endif
3355#ifdef CONFIG_SECCOMP_CACHE_DEBUG
3356 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3357#endif
3358#ifdef CONFIG_KSM
3359 ONE("ksm_merging_pages", S_IRUSR, proc_pid_ksm_merging_pages),
3360 ONE("ksm_stat", S_IRUSR, proc_pid_ksm_stat),
3361#endif
3362};
3363
3364static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3365{
3366 return proc_pident_readdir(file, ctx,
3367 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3368}
3369
3370static const struct file_operations proc_tgid_base_operations = {
3371 .read = generic_read_dir,
3372 .iterate_shared = proc_tgid_base_readdir,
3373 .llseek = generic_file_llseek,
3374};
3375
3376struct pid *tgid_pidfd_to_pid(const struct file *file)
3377{
3378 if (file->f_op != &proc_tgid_base_operations)
3379 return ERR_PTR(-EBADF);
3380
3381 return proc_pid(file_inode(file));
3382}
3383
3384static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3385{
3386 return proc_pident_lookup(dir, dentry,
3387 tgid_base_stuff,
3388 tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
3389}
3390
3391static const struct inode_operations proc_tgid_base_inode_operations = {
3392 .lookup = proc_tgid_base_lookup,
3393 .getattr = pid_getattr,
3394 .setattr = proc_setattr,
3395 .permission = proc_pid_permission,
3396};
3397
3398/**
3399 * proc_flush_pid - Remove dcache entries for @pid from the /proc dcache.
3400 * @pid: pid that should be flushed.
3401 *
3402 * This function walks a list of inodes (that belong to any proc
3403 * filesystem) that are attached to the pid and flushes them from
3404 * the dentry cache.
3405 *
3406 * It is safe and reasonable to cache /proc entries for a task until
3407 * that task exits. After that they just clog up the dcache with
3408 * useless entries, possibly causing useful dcache entries to be
3409 * flushed instead. This routine is provided to flush those useless
3410 * dcache entries when a process is reaped.
3411 *
3412 * NOTE: This routine is just an optimization so it does not guarantee
3413 * that no dcache entries will exist after a process is reaped
3414 * it just makes it very unlikely that any will persist.
3415 */
3416
3417void proc_flush_pid(struct pid *pid)
3418{
3419 proc_invalidate_siblings_dcache(&pid->inodes, &pid->lock);
3420}
3421
3422static struct dentry *proc_pid_instantiate(struct dentry * dentry,
3423 struct task_struct *task, const void *ptr)
3424{
3425 struct inode *inode;
3426
3427 inode = proc_pid_make_base_inode(dentry->d_sb, task,
3428 S_IFDIR | S_IRUGO | S_IXUGO);
3429 if (!inode)
3430 return ERR_PTR(-ENOENT);
3431
3432 inode->i_op = &proc_tgid_base_inode_operations;
3433 inode->i_fop = &proc_tgid_base_operations;
3434 inode->i_flags|=S_IMMUTABLE;
3435
3436 set_nlink(inode, nlink_tgid);
3437 pid_update_inode(task, inode);
3438
3439 d_set_d_op(dentry, &pid_dentry_operations);
3440 return d_splice_alias(inode, dentry);
3441}
3442
3443struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
3444{
3445 struct task_struct *task;
3446 unsigned tgid;
3447 struct proc_fs_info *fs_info;
3448 struct pid_namespace *ns;
3449 struct dentry *result = ERR_PTR(-ENOENT);
3450
3451 tgid = name_to_int(&dentry->d_name);
3452 if (tgid == ~0U)
3453 goto out;
3454
3455 fs_info = proc_sb_info(dentry->d_sb);
3456 ns = fs_info->pid_ns;
3457 rcu_read_lock();
3458 task = find_task_by_pid_ns(tgid, ns);
3459 if (task)
3460 get_task_struct(task);
3461 rcu_read_unlock();
3462 if (!task)
3463 goto out;
3464
3465 /* Limit procfs to only ptraceable tasks */
3466 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE) {
3467 if (!has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS))
3468 goto out_put_task;
3469 }
3470
3471 result = proc_pid_instantiate(dentry, task, NULL);
3472out_put_task:
3473 put_task_struct(task);
3474out:
3475 return result;
3476}
3477
3478/*
3479 * Find the first task with tgid >= tgid
3480 *
3481 */
3482struct tgid_iter {
3483 unsigned int tgid;
3484 struct task_struct *task;
3485};
3486static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3487{
3488 struct pid *pid;
3489
3490 if (iter.task)
3491 put_task_struct(iter.task);
3492 rcu_read_lock();
3493retry:
3494 iter.task = NULL;
3495 pid = find_ge_pid(iter.tgid, ns);
3496 if (pid) {
3497 iter.tgid = pid_nr_ns(pid, ns);
3498 iter.task = pid_task(pid, PIDTYPE_TGID);
3499 if (!iter.task) {
3500 iter.tgid += 1;
3501 goto retry;
3502 }
3503 get_task_struct(iter.task);
3504 }
3505 rcu_read_unlock();
3506 return iter;
3507}
3508
3509#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3510
3511/* for the /proc/ directory itself, after non-process stuff has been done */
3512int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3513{
3514 struct tgid_iter iter;
3515 struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb);
3516 struct pid_namespace *ns = proc_pid_ns(file_inode(file)->i_sb);
3517 loff_t pos = ctx->pos;
3518
3519 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3520 return 0;
3521
3522 if (pos == TGID_OFFSET - 2) {
3523 struct inode *inode = d_inode(fs_info->proc_self);
3524 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3525 return 0;
3526 ctx->pos = pos = pos + 1;
3527 }
3528 if (pos == TGID_OFFSET - 1) {
3529 struct inode *inode = d_inode(fs_info->proc_thread_self);
3530 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3531 return 0;
3532 ctx->pos = pos = pos + 1;
3533 }
3534 iter.tgid = pos - TGID_OFFSET;
3535 iter.task = NULL;
3536 for (iter = next_tgid(ns, iter);
3537 iter.task;
3538 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3539 char name[10 + 1];
3540 unsigned int len;
3541
3542 cond_resched();
3543 if (!has_pid_permissions(fs_info, iter.task, HIDEPID_INVISIBLE))
3544 continue;
3545
3546 len = snprintf(name, sizeof(name), "%u", iter.tgid);
3547 ctx->pos = iter.tgid + TGID_OFFSET;
3548 if (!proc_fill_cache(file, ctx, name, len,
3549 proc_pid_instantiate, iter.task, NULL)) {
3550 put_task_struct(iter.task);
3551 return 0;
3552 }
3553 }
3554 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3555 return 0;
3556}
3557
3558/*
3559 * proc_tid_comm_permission is a special permission function exclusively
3560 * used for the node /proc/<pid>/task/<tid>/comm.
3561 * It bypasses generic permission checks in the case where a task of the same
3562 * task group attempts to access the node.
3563 * The rationale behind this is that glibc and bionic access this node for
3564 * cross thread naming (pthread_set/getname_np(!self)). However, if
3565 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3566 * which locks out the cross thread naming implementation.
3567 * This function makes sure that the node is always accessible for members of
3568 * same thread group.
3569 */
3570static int proc_tid_comm_permission(struct mnt_idmap *idmap,
3571 struct inode *inode, int mask)
3572{
3573 bool is_same_tgroup;
3574 struct task_struct *task;
3575
3576 task = get_proc_task(inode);
3577 if (!task)
3578 return -ESRCH;
3579 is_same_tgroup = same_thread_group(current, task);
3580 put_task_struct(task);
3581
3582 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3583 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3584 * read or written by the members of the corresponding
3585 * thread group.
3586 */
3587 return 0;
3588 }
3589
3590 return generic_permission(&nop_mnt_idmap, inode, mask);
3591}
3592
3593static const struct inode_operations proc_tid_comm_inode_operations = {
3594 .setattr = proc_setattr,
3595 .permission = proc_tid_comm_permission,
3596};
3597
3598/*
3599 * Tasks
3600 */
3601static const struct pid_entry tid_base_stuff[] = {
3602 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3603 DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3604 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3605#ifdef CONFIG_NET
3606 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3607#endif
3608 REG("environ", S_IRUSR, proc_environ_operations),
3609 REG("auxv", S_IRUSR, proc_auxv_operations),
3610 ONE("status", S_IRUGO, proc_pid_status),
3611 ONE("personality", S_IRUSR, proc_pid_personality),
3612 ONE("limits", S_IRUGO, proc_pid_limits),
3613#ifdef CONFIG_SCHED_DEBUG
3614 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3615#endif
3616 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3617 &proc_tid_comm_inode_operations,
3618 &proc_pid_set_comm_operations, {}),
3619#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3620 ONE("syscall", S_IRUSR, proc_pid_syscall),
3621#endif
3622 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3623 ONE("stat", S_IRUGO, proc_tid_stat),
3624 ONE("statm", S_IRUGO, proc_pid_statm),
3625 REG("maps", S_IRUGO, proc_pid_maps_operations),
3626#ifdef CONFIG_PROC_CHILDREN
3627 REG("children", S_IRUGO, proc_tid_children_operations),
3628#endif
3629#ifdef CONFIG_NUMA
3630 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3631#endif
3632 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3633 LNK("cwd", proc_cwd_link),
3634 LNK("root", proc_root_link),
3635 LNK("exe", proc_exe_link),
3636 REG("mounts", S_IRUGO, proc_mounts_operations),
3637 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3638#ifdef CONFIG_PROC_PAGE_MONITOR
3639 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3640 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3641 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3642 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3643#endif
3644#ifdef CONFIG_SECURITY
3645 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3646#endif
3647#ifdef CONFIG_KALLSYMS
3648 ONE("wchan", S_IRUGO, proc_pid_wchan),
3649#endif
3650#ifdef CONFIG_STACKTRACE
3651 ONE("stack", S_IRUSR, proc_pid_stack),
3652#endif
3653#ifdef CONFIG_SCHED_INFO
3654 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3655#endif
3656#ifdef CONFIG_LATENCYTOP
3657 REG("latency", S_IRUGO, proc_lstats_operations),
3658#endif
3659#ifdef CONFIG_PROC_PID_CPUSET
3660 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3661#endif
3662#ifdef CONFIG_CGROUPS
3663 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3664#endif
3665#ifdef CONFIG_PROC_CPU_RESCTRL
3666 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3667#endif
3668 ONE("oom_score", S_IRUGO, proc_oom_score),
3669 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3670 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3671#ifdef CONFIG_AUDIT
3672 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3673 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3674#endif
3675#ifdef CONFIG_FAULT_INJECTION
3676 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3677 REG("fail-nth", 0644, proc_fail_nth_operations),
3678#endif
3679#ifdef CONFIG_TASK_IO_ACCOUNTING
3680 ONE("io", S_IRUSR, proc_tid_io_accounting),
3681#endif
3682#ifdef CONFIG_USER_NS
3683 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3684 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3685 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3686 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3687#endif
3688#ifdef CONFIG_LIVEPATCH
3689 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3690#endif
3691#ifdef CONFIG_PROC_PID_ARCH_STATUS
3692 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3693#endif
3694#ifdef CONFIG_SECCOMP_CACHE_DEBUG
3695 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3696#endif
3697#ifdef CONFIG_KSM
3698 ONE("ksm_merging_pages", S_IRUSR, proc_pid_ksm_merging_pages),
3699 ONE("ksm_stat", S_IRUSR, proc_pid_ksm_stat),
3700#endif
3701};
3702
3703static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3704{
3705 return proc_pident_readdir(file, ctx,
3706 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3707}
3708
3709static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3710{
3711 return proc_pident_lookup(dir, dentry,
3712 tid_base_stuff,
3713 tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
3714}
3715
3716static const struct file_operations proc_tid_base_operations = {
3717 .read = generic_read_dir,
3718 .iterate_shared = proc_tid_base_readdir,
3719 .llseek = generic_file_llseek,
3720};
3721
3722static const struct inode_operations proc_tid_base_inode_operations = {
3723 .lookup = proc_tid_base_lookup,
3724 .getattr = pid_getattr,
3725 .setattr = proc_setattr,
3726};
3727
3728static struct dentry *proc_task_instantiate(struct dentry *dentry,
3729 struct task_struct *task, const void *ptr)
3730{
3731 struct inode *inode;
3732 inode = proc_pid_make_base_inode(dentry->d_sb, task,
3733 S_IFDIR | S_IRUGO | S_IXUGO);
3734 if (!inode)
3735 return ERR_PTR(-ENOENT);
3736
3737 inode->i_op = &proc_tid_base_inode_operations;
3738 inode->i_fop = &proc_tid_base_operations;
3739 inode->i_flags |= S_IMMUTABLE;
3740
3741 set_nlink(inode, nlink_tid);
3742 pid_update_inode(task, inode);
3743
3744 d_set_d_op(dentry, &pid_dentry_operations);
3745 return d_splice_alias(inode, dentry);
3746}
3747
3748static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3749{
3750 struct task_struct *task;
3751 struct task_struct *leader = get_proc_task(dir);
3752 unsigned tid;
3753 struct proc_fs_info *fs_info;
3754 struct pid_namespace *ns;
3755 struct dentry *result = ERR_PTR(-ENOENT);
3756
3757 if (!leader)
3758 goto out_no_task;
3759
3760 tid = name_to_int(&dentry->d_name);
3761 if (tid == ~0U)
3762 goto out;
3763
3764 fs_info = proc_sb_info(dentry->d_sb);
3765 ns = fs_info->pid_ns;
3766 rcu_read_lock();
3767 task = find_task_by_pid_ns(tid, ns);
3768 if (task)
3769 get_task_struct(task);
3770 rcu_read_unlock();
3771 if (!task)
3772 goto out;
3773 if (!same_thread_group(leader, task))
3774 goto out_drop_task;
3775
3776 result = proc_task_instantiate(dentry, task, NULL);
3777out_drop_task:
3778 put_task_struct(task);
3779out:
3780 put_task_struct(leader);
3781out_no_task:
3782 return result;
3783}
3784
3785/*
3786 * Find the first tid of a thread group to return to user space.
3787 *
3788 * Usually this is just the thread group leader, but if the users
3789 * buffer was too small or there was a seek into the middle of the
3790 * directory we have more work todo.
3791 *
3792 * In the case of a short read we start with find_task_by_pid.
3793 *
3794 * In the case of a seek we start with the leader and walk nr
3795 * threads past it.
3796 */
3797static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3798 struct pid_namespace *ns)
3799{
3800 struct task_struct *pos, *task;
3801 unsigned long nr = f_pos;
3802
3803 if (nr != f_pos) /* 32bit overflow? */
3804 return NULL;
3805
3806 rcu_read_lock();
3807 task = pid_task(pid, PIDTYPE_PID);
3808 if (!task)
3809 goto fail;
3810
3811 /* Attempt to start with the tid of a thread */
3812 if (tid && nr) {
3813 pos = find_task_by_pid_ns(tid, ns);
3814 if (pos && same_thread_group(pos, task))
3815 goto found;
3816 }
3817
3818 /* If nr exceeds the number of threads there is nothing todo */
3819 if (nr >= get_nr_threads(task))
3820 goto fail;
3821
3822 /* If we haven't found our starting place yet start
3823 * with the leader and walk nr threads forward.
3824 */
3825 for_each_thread(task, pos) {
3826 if (!nr--)
3827 goto found;
3828 }
3829fail:
3830 pos = NULL;
3831 goto out;
3832found:
3833 get_task_struct(pos);
3834out:
3835 rcu_read_unlock();
3836 return pos;
3837}
3838
3839/*
3840 * Find the next thread in the thread list.
3841 * Return NULL if there is an error or no next thread.
3842 *
3843 * The reference to the input task_struct is released.
3844 */
3845static struct task_struct *next_tid(struct task_struct *start)
3846{
3847 struct task_struct *pos = NULL;
3848 rcu_read_lock();
3849 if (pid_alive(start)) {
3850 pos = __next_thread(start);
3851 if (pos)
3852 get_task_struct(pos);
3853 }
3854 rcu_read_unlock();
3855 put_task_struct(start);
3856 return pos;
3857}
3858
3859/* for the /proc/TGID/task/ directories */
3860static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3861{
3862 struct inode *inode = file_inode(file);
3863 struct task_struct *task;
3864 struct pid_namespace *ns;
3865 int tid;
3866
3867 if (proc_inode_is_dead(inode))
3868 return -ENOENT;
3869
3870 if (!dir_emit_dots(file, ctx))
3871 return 0;
3872
3873 /* f_version caches the tgid value that the last readdir call couldn't
3874 * return. lseek aka telldir automagically resets f_version to 0.
3875 */
3876 ns = proc_pid_ns(inode->i_sb);
3877 tid = (int)file->f_version;
3878 file->f_version = 0;
3879 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3880 task;
3881 task = next_tid(task), ctx->pos++) {
3882 char name[10 + 1];
3883 unsigned int len;
3884
3885 tid = task_pid_nr_ns(task, ns);
3886 if (!tid)
3887 continue; /* The task has just exited. */
3888 len = snprintf(name, sizeof(name), "%u", tid);
3889 if (!proc_fill_cache(file, ctx, name, len,
3890 proc_task_instantiate, task, NULL)) {
3891 /* returning this tgid failed, save it as the first
3892 * pid for the next readir call */
3893 file->f_version = (u64)tid;
3894 put_task_struct(task);
3895 break;
3896 }
3897 }
3898
3899 return 0;
3900}
3901
3902static int proc_task_getattr(struct mnt_idmap *idmap,
3903 const struct path *path, struct kstat *stat,
3904 u32 request_mask, unsigned int query_flags)
3905{
3906 struct inode *inode = d_inode(path->dentry);
3907 struct task_struct *p = get_proc_task(inode);
3908 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
3909
3910 if (p) {
3911 stat->nlink += get_nr_threads(p);
3912 put_task_struct(p);
3913 }
3914
3915 return 0;
3916}
3917
3918static const struct inode_operations proc_task_inode_operations = {
3919 .lookup = proc_task_lookup,
3920 .getattr = proc_task_getattr,
3921 .setattr = proc_setattr,
3922 .permission = proc_pid_permission,
3923};
3924
3925static const struct file_operations proc_task_operations = {
3926 .read = generic_read_dir,
3927 .iterate_shared = proc_task_readdir,
3928 .llseek = generic_file_llseek,
3929};
3930
3931void __init set_proc_pid_nlink(void)
3932{
3933 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3934 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3935}