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 */
51 #include <linux/uaccess.h>
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/string.h>
63 #include <linux/seq_file.h>
64 #include <linux/namei.h>
65 #include <linux/mnt_namespace.h>
66 #include <linux/mm.h>
67 #include <linux/swap.h>
68 #include <linux/rcupdate.h>
69 #include <linux/kallsyms.h>
70 #include <linux/stacktrace.h>
71 #include <linux/resource.h>
72 #include <linux/module.h>
73 #include <linux/mount.h>
74 #include <linux/security.h>
75 #include <linux/ptrace.h>
76 #include <linux/tracehook.h>
77 #include <linux/printk.h>
78 #include <linux/cache.h>
79 #include <linux/cgroup.h>
80 #include <linux/cpuset.h>
81 #include <linux/audit.h>
82 #include <linux/poll.h>
83 #include <linux/nsproxy.h>
84 #include <linux/oom.h>
85 #include <linux/elf.h>
86 #include <linux/pid_namespace.h>
87 #include <linux/user_namespace.h>
88 #include <linux/fs_struct.h>
89 #include <linux/slab.h>
90 #include <linux/sched/autogroup.h>
91 #include <linux/sched/mm.h>
92 #include <linux/sched/coredump.h>
93 #include <linux/sched/debug.h>
94 #include <linux/sched/stat.h>
95 #include <linux/flex_array.h>
96 #include <linux/posix-timers.h>
97 #include <trace/events/oom.h>
98 #include "internal.h"
99 #include "fd.h"
101 #include "../../lib/kstrtox.h"
103 /* NOTE:
104 * Implementing inode permission operations in /proc is almost
105 * certainly an error. Permission checks need to happen during
106 * each system call not at open time. The reason is that most of
107 * what we wish to check for permissions in /proc varies at runtime.
108 *
109 * The classic example of a problem is opening file descriptors
110 * in /proc for a task before it execs a suid executable.
111 */
113 static u8 nlink_tid __ro_after_init;
114 static u8 nlink_tgid __ro_after_init;
116 struct pid_entry {
117 const char *name;
118 unsigned int len;
119 umode_t mode;
120 const struct inode_operations *iop;
121 const struct file_operations *fop;
122 union proc_op op;
123 };
125 #define NOD(NAME, MODE, IOP, FOP, OP) { \
126 .name = (NAME), \
127 .len = sizeof(NAME) - 1, \
128 .mode = MODE, \
129 .iop = IOP, \
130 .fop = FOP, \
131 .op = OP, \
132 }
134 #define DIR(NAME, MODE, iops, fops) \
135 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
136 #define LNK(NAME, get_link) \
137 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
138 &proc_pid_link_inode_operations, NULL, \
139 { .proc_get_link = get_link } )
140 #define REG(NAME, MODE, fops) \
141 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
142 #define ONE(NAME, MODE, show) \
143 NOD(NAME, (S_IFREG|(MODE)), \
144 NULL, &proc_single_file_operations, \
145 { .proc_show = show } )
147 /*
148 * Count the number of hardlinks for the pid_entry table, excluding the .
149 * and .. links.
150 */
151 static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
152 unsigned int n)
153 {
154 unsigned int i;
155 unsigned int count;
157 count = 2;
158 for (i = 0; i < n; ++i) {
159 if (S_ISDIR(entries[i].mode))
160 ++count;
161 }
163 return count;
164 }
166 static int get_task_root(struct task_struct *task, struct path *root)
167 {
168 int result = -ENOENT;
170 task_lock(task);
171 if (task->fs) {
172 get_fs_root(task->fs, root);
173 result = 0;
174 }
175 task_unlock(task);
176 return result;
177 }
179 static int proc_cwd_link(struct dentry *dentry, struct path *path)
180 {
181 struct task_struct *task = get_proc_task(d_inode(dentry));
182 int result = -ENOENT;
184 if (task) {
185 task_lock(task);
186 if (task->fs) {
187 get_fs_pwd(task->fs, path);
188 result = 0;
189 }
190 task_unlock(task);
191 put_task_struct(task);
192 }
193 return result;
194 }
196 static int proc_root_link(struct dentry *dentry, struct path *path)
197 {
198 struct task_struct *task = get_proc_task(d_inode(dentry));
199 int result = -ENOENT;
201 if (task) {
202 result = get_task_root(task, path);
203 put_task_struct(task);
204 }
205 return result;
206 }
208 static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
209 size_t count, loff_t *ppos)
210 {
211 unsigned long arg_start, arg_end, env_start, env_end;
212 unsigned long pos, len;
213 char *page;
215 /* Check if process spawned far enough to have cmdline. */
216 if (!mm->env_end)
217 return 0;
219 spin_lock(&mm->arg_lock);
220 arg_start = mm->arg_start;
221 arg_end = mm->arg_end;
222 env_start = mm->env_start;
223 env_end = mm->env_end;
224 spin_unlock(&mm->arg_lock);
226 if (arg_start >= arg_end)
227 return 0;
229 /*
230 * We have traditionally allowed the user to re-write
231 * the argument strings and overflow the end result
232 * into the environment section. But only do that if
233 * the environment area is contiguous to the arguments.
234 */
235 if (env_start != arg_end || env_start >= env_end)
236 env_start = env_end = arg_end;
238 /* .. and limit it to a maximum of one page of slop */
239 if (env_end >= arg_end + PAGE_SIZE)
240 env_end = arg_end + PAGE_SIZE - 1;
242 /* We're not going to care if "*ppos" has high bits set */
243 pos = arg_start + *ppos;
245 /* .. but we do check the result is in the proper range */
246 if (pos < arg_start || pos >= env_end)
247 return 0;
249 /* .. and we never go past env_end */
250 if (env_end - pos < count)
251 count = env_end - pos;
253 page = (char *)__get_free_page(GFP_KERNEL);
254 if (!page)
255 return -ENOMEM;
257 len = 0;
258 while (count) {
259 int got;
260 size_t size = min_t(size_t, PAGE_SIZE, count);
261 long offset;
263 /*
264 * Are we already starting past the official end?
265 * We always include the last byte that is *supposed*
266 * to be NUL
267 */
268 offset = (pos >= arg_end) ? pos - arg_end + 1 : 0;
270 got = access_remote_vm(mm, pos - offset, page, size + offset, FOLL_ANON);
271 if (got <= offset)
272 break;
273 got -= offset;
275 /* Don't walk past a NUL character once you hit arg_end */
276 if (pos + got >= arg_end) {
277 int n = 0;
279 /*
280 * If we started before 'arg_end' but ended up
281 * at or after it, we start the NUL character
282 * check at arg_end-1 (where we expect the normal
283 * EOF to be).
284 *
285 * NOTE! This is smaller than 'got', because
286 * pos + got >= arg_end
287 */
288 if (pos < arg_end)
289 n = arg_end - pos - 1;
291 /* Cut off at first NUL after 'n' */
292 got = n + strnlen(page+n, offset+got-n);
293 if (got < offset)
294 break;
295 got -= offset;
297 /* Include the NUL if it existed */
298 if (got < size)
299 got++;
300 }
302 got -= copy_to_user(buf, page+offset, got);
303 if (unlikely(!got)) {
304 if (!len)
305 len = -EFAULT;
306 break;
307 }
308 pos += got;
309 buf += got;
310 len += got;
311 count -= got;
312 }
314 free_page((unsigned long)page);
315 return len;
316 }
318 static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf,
319 size_t count, loff_t *pos)
320 {
321 struct mm_struct *mm;
322 ssize_t ret;
324 mm = get_task_mm(tsk);
325 if (!mm)
326 return 0;
328 ret = get_mm_cmdline(mm, buf, count, pos);
329 mmput(mm);
330 return ret;
331 }
333 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
334 size_t count, loff_t *pos)
335 {
336 struct task_struct *tsk;
337 ssize_t ret;
339 BUG_ON(*pos < 0);
341 tsk = get_proc_task(file_inode(file));
342 if (!tsk)
343 return -ESRCH;
344 ret = get_task_cmdline(tsk, buf, count, pos);
345 put_task_struct(tsk);
346 if (ret > 0)
347 *pos += ret;
348 return ret;
349 }
351 static const struct file_operations proc_pid_cmdline_ops = {
352 .read = proc_pid_cmdline_read,
353 .llseek = generic_file_llseek,
354 };
356 #ifdef CONFIG_KALLSYMS
357 /*
358 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
359 * Returns the resolved symbol. If that fails, simply return the address.
360 */
361 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
362 struct pid *pid, struct task_struct *task)
363 {
364 unsigned long wchan;
365 char symname[KSYM_NAME_LEN];
367 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
368 goto print0;
370 wchan = get_wchan(task);
371 if (wchan && !lookup_symbol_name(wchan, symname)) {
372 seq_puts(m, symname);
373 return 0;
374 }
376 print0:
377 seq_putc(m, '0');
378 return 0;
379 }
380 #endif /* CONFIG_KALLSYMS */
382 static int lock_trace(struct task_struct *task)
383 {
384 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
385 if (err)
386 return err;
387 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
388 mutex_unlock(&task->signal->cred_guard_mutex);
389 return -EPERM;
390 }
391 return 0;
392 }
394 static void unlock_trace(struct task_struct *task)
395 {
396 mutex_unlock(&task->signal->cred_guard_mutex);
397 }
399 #ifdef CONFIG_STACKTRACE
401 #define MAX_STACK_TRACE_DEPTH 64
403 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
404 struct pid *pid, struct task_struct *task)
405 {
406 struct stack_trace trace;
407 unsigned long *entries;
408 int err;
410 /*
411 * The ability to racily run the kernel stack unwinder on a running task
412 * and then observe the unwinder output is scary; while it is useful for
413 * debugging kernel issues, it can also allow an attacker to leak kernel
414 * stack contents.
415 * Doing this in a manner that is at least safe from races would require
416 * some work to ensure that the remote task can not be scheduled; and
417 * even then, this would still expose the unwinder as local attack
418 * surface.
419 * Therefore, this interface is restricted to root.
420 */
421 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
422 return -EACCES;
424 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
425 GFP_KERNEL);
426 if (!entries)
427 return -ENOMEM;
429 trace.nr_entries = 0;
430 trace.max_entries = MAX_STACK_TRACE_DEPTH;
431 trace.entries = entries;
432 trace.skip = 0;
434 err = lock_trace(task);
435 if (!err) {
436 unsigned int i;
438 save_stack_trace_tsk(task, &trace);
440 for (i = 0; i < trace.nr_entries; i++) {
441 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
442 }
443 unlock_trace(task);
444 }
445 kfree(entries);
447 return err;
448 }
449 #endif
451 #ifdef CONFIG_SCHED_INFO
452 /*
453 * Provides /proc/PID/schedstat
454 */
455 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
456 struct pid *pid, struct task_struct *task)
457 {
458 if (unlikely(!sched_info_on()))
459 seq_printf(m, "0 0 0\n");
460 else
461 seq_printf(m, "%llu %llu %lu\n",
462 (unsigned long long)task->se.sum_exec_runtime,
463 (unsigned long long)task->sched_info.run_delay,
464 task->sched_info.pcount);
466 return 0;
467 }
468 #endif
470 #ifdef CONFIG_LATENCYTOP
471 static int lstats_show_proc(struct seq_file *m, void *v)
472 {
473 int i;
474 struct inode *inode = m->private;
475 struct task_struct *task = get_proc_task(inode);
477 if (!task)
478 return -ESRCH;
479 seq_puts(m, "Latency Top version : v0.1\n");
480 for (i = 0; i < LT_SAVECOUNT; i++) {
481 struct latency_record *lr = &task->latency_record[i];
482 if (lr->backtrace[0]) {
483 int q;
484 seq_printf(m, "%i %li %li",
485 lr->count, lr->time, lr->max);
486 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
487 unsigned long bt = lr->backtrace[q];
488 if (!bt)
489 break;
490 if (bt == ULONG_MAX)
491 break;
492 seq_printf(m, " %ps", (void *)bt);
493 }
494 seq_putc(m, '\n');
495 }
497 }
498 put_task_struct(task);
499 return 0;
500 }
502 static int lstats_open(struct inode *inode, struct file *file)
503 {
504 return single_open(file, lstats_show_proc, inode);
505 }
507 static ssize_t lstats_write(struct file *file, const char __user *buf,
508 size_t count, loff_t *offs)
509 {
510 struct task_struct *task = get_proc_task(file_inode(file));
512 if (!task)
513 return -ESRCH;
514 clear_all_latency_tracing(task);
515 put_task_struct(task);
517 return count;
518 }
520 static const struct file_operations proc_lstats_operations = {
521 .open = lstats_open,
522 .read = seq_read,
523 .write = lstats_write,
524 .llseek = seq_lseek,
525 .release = single_release,
526 };
528 #endif
530 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
531 struct pid *pid, struct task_struct *task)
532 {
533 unsigned long totalpages = totalram_pages + total_swap_pages;
534 unsigned long points = 0;
536 points = oom_badness(task, NULL, NULL, totalpages) *
537 1000 / totalpages;
538 seq_printf(m, "%lu\n", points);
540 return 0;
541 }
543 struct limit_names {
544 const char *name;
545 const char *unit;
546 };
548 static const struct limit_names lnames[RLIM_NLIMITS] = {
549 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
550 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
551 [RLIMIT_DATA] = {"Max data size", "bytes"},
552 [RLIMIT_STACK] = {"Max stack size", "bytes"},
553 [RLIMIT_CORE] = {"Max core file size", "bytes"},
554 [RLIMIT_RSS] = {"Max resident set", "bytes"},
555 [RLIMIT_NPROC] = {"Max processes", "processes"},
556 [RLIMIT_NOFILE] = {"Max open files", "files"},
557 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
558 [RLIMIT_AS] = {"Max address space", "bytes"},
559 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
560 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
561 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
562 [RLIMIT_NICE] = {"Max nice priority", NULL},
563 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
564 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
565 };
567 /* Display limits for a process */
568 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
569 struct pid *pid, struct task_struct *task)
570 {
571 unsigned int i;
572 unsigned long flags;
574 struct rlimit rlim[RLIM_NLIMITS];
576 if (!lock_task_sighand(task, &flags))
577 return 0;
578 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
579 unlock_task_sighand(task, &flags);
581 /*
582 * print the file header
583 */
584 seq_printf(m, "%-25s %-20s %-20s %-10s\n",
585 "Limit", "Soft Limit", "Hard Limit", "Units");
587 for (i = 0; i < RLIM_NLIMITS; i++) {
588 if (rlim[i].rlim_cur == RLIM_INFINITY)
589 seq_printf(m, "%-25s %-20s ",
590 lnames[i].name, "unlimited");
591 else
592 seq_printf(m, "%-25s %-20lu ",
593 lnames[i].name, rlim[i].rlim_cur);
595 if (rlim[i].rlim_max == RLIM_INFINITY)
596 seq_printf(m, "%-20s ", "unlimited");
597 else
598 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
600 if (lnames[i].unit)
601 seq_printf(m, "%-10s\n", lnames[i].unit);
602 else
603 seq_putc(m, '\n');
604 }
606 return 0;
607 }
609 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
610 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
611 struct pid *pid, struct task_struct *task)
612 {
613 long nr;
614 unsigned long args[6], sp, pc;
615 int res;
617 res = lock_trace(task);
618 if (res)
619 return res;
621 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
622 seq_puts(m, "running\n");
623 else if (nr < 0)
624 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
625 else
626 seq_printf(m,
627 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
628 nr,
629 args[0], args[1], args[2], args[3], args[4], args[5],
630 sp, pc);
631 unlock_trace(task);
633 return 0;
634 }
635 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
637 /************************************************************************/
638 /* Here the fs part begins */
639 /************************************************************************/
641 /* permission checks */
642 static int proc_fd_access_allowed(struct inode *inode)
643 {
644 struct task_struct *task;
645 int allowed = 0;
646 /* Allow access to a task's file descriptors if it is us or we
647 * may use ptrace attach to the process and find out that
648 * information.
649 */
650 task = get_proc_task(inode);
651 if (task) {
652 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
653 put_task_struct(task);
654 }
655 return allowed;
656 }
658 int proc_setattr(struct dentry *dentry, struct iattr *attr)
659 {
660 int error;
661 struct inode *inode = d_inode(dentry);
663 if (attr->ia_valid & ATTR_MODE)
664 return -EPERM;
666 error = setattr_prepare(dentry, attr);
667 if (error)
668 return error;
670 setattr_copy(inode, attr);
671 mark_inode_dirty(inode);
672 return 0;
673 }
675 /*
676 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
677 * or euid/egid (for hide_pid_min=2)?
678 */
679 static bool has_pid_permissions(struct pid_namespace *pid,
680 struct task_struct *task,
681 int hide_pid_min)
682 {
683 if (pid->hide_pid < hide_pid_min)
684 return true;
685 if (in_group_p(pid->pid_gid))
686 return true;
687 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
688 }
691 static int proc_pid_permission(struct inode *inode, int mask)
692 {
693 struct pid_namespace *pid = proc_pid_ns(inode);
694 struct task_struct *task;
695 bool has_perms;
697 task = get_proc_task(inode);
698 if (!task)
699 return -ESRCH;
700 has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS);
701 put_task_struct(task);
703 if (!has_perms) {
704 if (pid->hide_pid == HIDEPID_INVISIBLE) {
705 /*
706 * Let's make getdents(), stat(), and open()
707 * consistent with each other. If a process
708 * may not stat() a file, it shouldn't be seen
709 * in procfs at all.
710 */
711 return -ENOENT;
712 }
714 return -EPERM;
715 }
716 return generic_permission(inode, mask);
717 }
721 static const struct inode_operations proc_def_inode_operations = {
722 .setattr = proc_setattr,
723 };
725 static int proc_single_show(struct seq_file *m, void *v)
726 {
727 struct inode *inode = m->private;
728 struct pid_namespace *ns = proc_pid_ns(inode);
729 struct pid *pid = proc_pid(inode);
730 struct task_struct *task;
731 int ret;
733 task = get_pid_task(pid, PIDTYPE_PID);
734 if (!task)
735 return -ESRCH;
737 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
739 put_task_struct(task);
740 return ret;
741 }
743 static int proc_single_open(struct inode *inode, struct file *filp)
744 {
745 return single_open(filp, proc_single_show, inode);
746 }
748 static const struct file_operations proc_single_file_operations = {
749 .open = proc_single_open,
750 .read = seq_read,
751 .llseek = seq_lseek,
752 .release = single_release,
753 };
756 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
757 {
758 struct task_struct *task = get_proc_task(inode);
759 struct mm_struct *mm = ERR_PTR(-ESRCH);
761 if (task) {
762 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
763 put_task_struct(task);
765 if (!IS_ERR_OR_NULL(mm)) {
766 /* ensure this mm_struct can't be freed */
767 mmgrab(mm);
768 /* but do not pin its memory */
769 mmput(mm);
770 }
771 }
773 return mm;
774 }
776 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
777 {
778 struct mm_struct *mm = proc_mem_open(inode, mode);
780 if (IS_ERR(mm))
781 return PTR_ERR(mm);
783 file->private_data = mm;
784 return 0;
785 }
787 static int mem_open(struct inode *inode, struct file *file)
788 {
789 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
791 /* OK to pass negative loff_t, we can catch out-of-range */
792 file->f_mode |= FMODE_UNSIGNED_OFFSET;
794 return ret;
795 }
797 static ssize_t mem_rw(struct file *file, char __user *buf,
798 size_t count, loff_t *ppos, int write)
799 {
800 struct mm_struct *mm = file->private_data;
801 unsigned long addr = *ppos;
802 ssize_t copied;
803 char *page;
804 unsigned int flags;
806 if (!mm)
807 return 0;
809 page = (char *)__get_free_page(GFP_KERNEL);
810 if (!page)
811 return -ENOMEM;
813 copied = 0;
814 if (!mmget_not_zero(mm))
815 goto free;
817 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
819 while (count > 0) {
820 int this_len = min_t(int, count, PAGE_SIZE);
822 if (write && copy_from_user(page, buf, this_len)) {
823 copied = -EFAULT;
824 break;
825 }
827 this_len = access_remote_vm(mm, addr, page, this_len, flags);
828 if (!this_len) {
829 if (!copied)
830 copied = -EIO;
831 break;
832 }
834 if (!write && copy_to_user(buf, page, this_len)) {
835 copied = -EFAULT;
836 break;
837 }
839 buf += this_len;
840 addr += this_len;
841 copied += this_len;
842 count -= this_len;
843 }
844 *ppos = addr;
846 mmput(mm);
847 free:
848 free_page((unsigned long) page);
849 return copied;
850 }
852 static ssize_t mem_read(struct file *file, char __user *buf,
853 size_t count, loff_t *ppos)
854 {
855 return mem_rw(file, buf, count, ppos, 0);
856 }
858 static ssize_t mem_write(struct file *file, const char __user *buf,
859 size_t count, loff_t *ppos)
860 {
861 return mem_rw(file, (char __user*)buf, count, ppos, 1);
862 }
864 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
865 {
866 switch (orig) {
867 case 0:
868 file->f_pos = offset;
869 break;
870 case 1:
871 file->f_pos += offset;
872 break;
873 default:
874 return -EINVAL;
875 }
876 force_successful_syscall_return();
877 return file->f_pos;
878 }
880 static int mem_release(struct inode *inode, struct file *file)
881 {
882 struct mm_struct *mm = file->private_data;
883 if (mm)
884 mmdrop(mm);
885 return 0;
886 }
888 static const struct file_operations proc_mem_operations = {
889 .llseek = mem_lseek,
890 .read = mem_read,
891 .write = mem_write,
892 .open = mem_open,
893 .release = mem_release,
894 };
896 static int environ_open(struct inode *inode, struct file *file)
897 {
898 return __mem_open(inode, file, PTRACE_MODE_READ);
899 }
901 static ssize_t environ_read(struct file *file, char __user *buf,
902 size_t count, loff_t *ppos)
903 {
904 char *page;
905 unsigned long src = *ppos;
906 int ret = 0;
907 struct mm_struct *mm = file->private_data;
908 unsigned long env_start, env_end;
910 /* Ensure the process spawned far enough to have an environment. */
911 if (!mm || !mm->env_end)
912 return 0;
914 page = (char *)__get_free_page(GFP_KERNEL);
915 if (!page)
916 return -ENOMEM;
918 ret = 0;
919 if (!mmget_not_zero(mm))
920 goto free;
922 spin_lock(&mm->arg_lock);
923 env_start = mm->env_start;
924 env_end = mm->env_end;
925 spin_unlock(&mm->arg_lock);
927 while (count > 0) {
928 size_t this_len, max_len;
929 int retval;
931 if (src >= (env_end - env_start))
932 break;
934 this_len = env_end - (env_start + src);
936 max_len = min_t(size_t, PAGE_SIZE, count);
937 this_len = min(max_len, this_len);
939 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
941 if (retval <= 0) {
942 ret = retval;
943 break;
944 }
946 if (copy_to_user(buf, page, retval)) {
947 ret = -EFAULT;
948 break;
949 }
951 ret += retval;
952 src += retval;
953 buf += retval;
954 count -= retval;
955 }
956 *ppos = src;
957 mmput(mm);
959 free:
960 free_page((unsigned long) page);
961 return ret;
962 }
964 static const struct file_operations proc_environ_operations = {
965 .open = environ_open,
966 .read = environ_read,
967 .llseek = generic_file_llseek,
968 .release = mem_release,
969 };
971 static int auxv_open(struct inode *inode, struct file *file)
972 {
973 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
974 }
976 static ssize_t auxv_read(struct file *file, char __user *buf,
977 size_t count, loff_t *ppos)
978 {
979 struct mm_struct *mm = file->private_data;
980 unsigned int nwords = 0;
982 if (!mm)
983 return 0;
984 do {
985 nwords += 2;
986 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
987 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
988 nwords * sizeof(mm->saved_auxv[0]));
989 }
991 static const struct file_operations proc_auxv_operations = {
992 .open = auxv_open,
993 .read = auxv_read,
994 .llseek = generic_file_llseek,
995 .release = mem_release,
996 };
998 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
999 loff_t *ppos)
1000 {
1001 struct task_struct *task = get_proc_task(file_inode(file));
1002 char buffer[PROC_NUMBUF];
1003 int oom_adj = OOM_ADJUST_MIN;
1004 size_t len;
1006 if (!task)
1007 return -ESRCH;
1008 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1009 oom_adj = OOM_ADJUST_MAX;
1010 else
1011 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1012 OOM_SCORE_ADJ_MAX;
1013 put_task_struct(task);
1014 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1015 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1016 }
1018 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1019 {
1020 static DEFINE_MUTEX(oom_adj_mutex);
1021 struct mm_struct *mm = NULL;
1022 struct task_struct *task;
1023 int err = 0;
1025 task = get_proc_task(file_inode(file));
1026 if (!task)
1027 return -ESRCH;
1029 mutex_lock(&oom_adj_mutex);
1030 if (legacy) {
1031 if (oom_adj < task->signal->oom_score_adj &&
1032 !capable(CAP_SYS_RESOURCE)) {
1033 err = -EACCES;
1034 goto err_unlock;
1035 }
1036 /*
1037 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1038 * /proc/pid/oom_score_adj instead.
1039 */
1040 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1041 current->comm, task_pid_nr(current), task_pid_nr(task),
1042 task_pid_nr(task));
1043 } else {
1044 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1045 !capable(CAP_SYS_RESOURCE)) {
1046 err = -EACCES;
1047 goto err_unlock;
1048 }
1049 }
1051 /*
1052 * Make sure we will check other processes sharing the mm if this is
1053 * not vfrok which wants its own oom_score_adj.
1054 * pin the mm so it doesn't go away and get reused after task_unlock
1055 */
1056 if (!task->vfork_done) {
1057 struct task_struct *p = find_lock_task_mm(task);
1059 if (p) {
1060 if (atomic_read(&p->mm->mm_users) > 1) {
1061 mm = p->mm;
1062 mmgrab(mm);
1063 }
1064 task_unlock(p);
1065 }
1066 }
1068 task->signal->oom_score_adj = oom_adj;
1069 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1070 task->signal->oom_score_adj_min = (short)oom_adj;
1071 trace_oom_score_adj_update(task);
1073 if (mm) {
1074 struct task_struct *p;
1076 rcu_read_lock();
1077 for_each_process(p) {
1078 if (same_thread_group(task, p))
1079 continue;
1081 /* do not touch kernel threads or the global init */
1082 if (p->flags & PF_KTHREAD || is_global_init(p))
1083 continue;
1085 task_lock(p);
1086 if (!p->vfork_done && process_shares_mm(p, mm)) {
1087 pr_info("updating oom_score_adj for %d (%s) from %d to %d because it shares mm with %d (%s). Report if this is unexpected.\n",
1088 task_pid_nr(p), p->comm,
1089 p->signal->oom_score_adj, oom_adj,
1090 task_pid_nr(task), task->comm);
1091 p->signal->oom_score_adj = oom_adj;
1092 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1093 p->signal->oom_score_adj_min = (short)oom_adj;
1094 }
1095 task_unlock(p);
1096 }
1097 rcu_read_unlock();
1098 mmdrop(mm);
1099 }
1100 err_unlock:
1101 mutex_unlock(&oom_adj_mutex);
1102 put_task_struct(task);
1103 return err;
1104 }
1106 /*
1107 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1108 * kernels. The effective policy is defined by oom_score_adj, which has a
1109 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1110 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1111 * Processes that become oom disabled via oom_adj will still be oom disabled
1112 * with this implementation.
1113 *
1114 * oom_adj cannot be removed since existing userspace binaries use it.
1115 */
1116 static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1117 size_t count, loff_t *ppos)
1118 {
1119 char buffer[PROC_NUMBUF];
1120 int oom_adj;
1121 int err;
1123 memset(buffer, 0, sizeof(buffer));
1124 if (count > sizeof(buffer) - 1)
1125 count = sizeof(buffer) - 1;
1126 if (copy_from_user(buffer, buf, count)) {
1127 err = -EFAULT;
1128 goto out;
1129 }
1131 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1132 if (err)
1133 goto out;
1134 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1135 oom_adj != OOM_DISABLE) {
1136 err = -EINVAL;
1137 goto out;
1138 }
1140 /*
1141 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1142 * value is always attainable.
1143 */
1144 if (oom_adj == OOM_ADJUST_MAX)
1145 oom_adj = OOM_SCORE_ADJ_MAX;
1146 else
1147 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1149 err = __set_oom_adj(file, oom_adj, true);
1150 out:
1151 return err < 0 ? err : count;
1152 }
1154 static const struct file_operations proc_oom_adj_operations = {
1155 .read = oom_adj_read,
1156 .write = oom_adj_write,
1157 .llseek = generic_file_llseek,
1158 };
1160 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1161 size_t count, loff_t *ppos)
1162 {
1163 struct task_struct *task = get_proc_task(file_inode(file));
1164 char buffer[PROC_NUMBUF];
1165 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1166 size_t len;
1168 if (!task)
1169 return -ESRCH;
1170 oom_score_adj = task->signal->oom_score_adj;
1171 put_task_struct(task);
1172 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1173 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1174 }
1176 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1177 size_t count, loff_t *ppos)
1178 {
1179 char buffer[PROC_NUMBUF];
1180 int oom_score_adj;
1181 int err;
1183 memset(buffer, 0, sizeof(buffer));
1184 if (count > sizeof(buffer) - 1)
1185 count = sizeof(buffer) - 1;
1186 if (copy_from_user(buffer, buf, count)) {
1187 err = -EFAULT;
1188 goto out;
1189 }
1191 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1192 if (err)
1193 goto out;
1194 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1195 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1196 err = -EINVAL;
1197 goto out;
1198 }
1200 err = __set_oom_adj(file, oom_score_adj, false);
1201 out:
1202 return err < 0 ? err : count;
1203 }
1205 static const struct file_operations proc_oom_score_adj_operations = {
1206 .read = oom_score_adj_read,
1207 .write = oom_score_adj_write,
1208 .llseek = default_llseek,
1209 };
1211 #ifdef CONFIG_AUDITSYSCALL
1212 #define TMPBUFLEN 11
1213 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1214 size_t count, loff_t *ppos)
1215 {
1216 struct inode * inode = file_inode(file);
1217 struct task_struct *task = get_proc_task(inode);
1218 ssize_t length;
1219 char tmpbuf[TMPBUFLEN];
1221 if (!task)
1222 return -ESRCH;
1223 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1224 from_kuid(file->f_cred->user_ns,
1225 audit_get_loginuid(task)));
1226 put_task_struct(task);
1227 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1228 }
1230 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1231 size_t count, loff_t *ppos)
1232 {
1233 struct inode * inode = file_inode(file);
1234 uid_t loginuid;
1235 kuid_t kloginuid;
1236 int rv;
1238 rcu_read_lock();
1239 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1240 rcu_read_unlock();
1241 return -EPERM;
1242 }
1243 rcu_read_unlock();
1245 if (*ppos != 0) {
1246 /* No partial writes. */
1247 return -EINVAL;
1248 }
1250 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1251 if (rv < 0)
1252 return rv;
1254 /* is userspace tring to explicitly UNSET the loginuid? */
1255 if (loginuid == AUDIT_UID_UNSET) {
1256 kloginuid = INVALID_UID;
1257 } else {
1258 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1259 if (!uid_valid(kloginuid))
1260 return -EINVAL;
1261 }
1263 rv = audit_set_loginuid(kloginuid);
1264 if (rv < 0)
1265 return rv;
1266 return count;
1267 }
1269 static const struct file_operations proc_loginuid_operations = {
1270 .read = proc_loginuid_read,
1271 .write = proc_loginuid_write,
1272 .llseek = generic_file_llseek,
1273 };
1275 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1276 size_t count, loff_t *ppos)
1277 {
1278 struct inode * inode = file_inode(file);
1279 struct task_struct *task = get_proc_task(inode);
1280 ssize_t length;
1281 char tmpbuf[TMPBUFLEN];
1283 if (!task)
1284 return -ESRCH;
1285 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1286 audit_get_sessionid(task));
1287 put_task_struct(task);
1288 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1289 }
1291 static const struct file_operations proc_sessionid_operations = {
1292 .read = proc_sessionid_read,
1293 .llseek = generic_file_llseek,
1294 };
1295 #endif
1297 #ifdef CONFIG_FAULT_INJECTION
1298 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1299 size_t count, loff_t *ppos)
1300 {
1301 struct task_struct *task = get_proc_task(file_inode(file));
1302 char buffer[PROC_NUMBUF];
1303 size_t len;
1304 int make_it_fail;
1306 if (!task)
1307 return -ESRCH;
1308 make_it_fail = task->make_it_fail;
1309 put_task_struct(task);
1311 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1313 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1314 }
1316 static ssize_t proc_fault_inject_write(struct file * file,
1317 const char __user * buf, size_t count, loff_t *ppos)
1318 {
1319 struct task_struct *task;
1320 char buffer[PROC_NUMBUF];
1321 int make_it_fail;
1322 int rv;
1324 if (!capable(CAP_SYS_RESOURCE))
1325 return -EPERM;
1326 memset(buffer, 0, sizeof(buffer));
1327 if (count > sizeof(buffer) - 1)
1328 count = sizeof(buffer) - 1;
1329 if (copy_from_user(buffer, buf, count))
1330 return -EFAULT;
1331 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1332 if (rv < 0)
1333 return rv;
1334 if (make_it_fail < 0 || make_it_fail > 1)
1335 return -EINVAL;
1337 task = get_proc_task(file_inode(file));
1338 if (!task)
1339 return -ESRCH;
1340 task->make_it_fail = make_it_fail;
1341 put_task_struct(task);
1343 return count;
1344 }
1346 static const struct file_operations proc_fault_inject_operations = {
1347 .read = proc_fault_inject_read,
1348 .write = proc_fault_inject_write,
1349 .llseek = generic_file_llseek,
1350 };
1352 static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1353 size_t count, loff_t *ppos)
1354 {
1355 struct task_struct *task;
1356 int err;
1357 unsigned int n;
1359 err = kstrtouint_from_user(buf, count, 0, &n);
1360 if (err)
1361 return err;
1363 task = get_proc_task(file_inode(file));
1364 if (!task)
1365 return -ESRCH;
1366 task->fail_nth = n;
1367 put_task_struct(task);
1369 return count;
1370 }
1372 static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1373 size_t count, loff_t *ppos)
1374 {
1375 struct task_struct *task;
1376 char numbuf[PROC_NUMBUF];
1377 ssize_t len;
1379 task = get_proc_task(file_inode(file));
1380 if (!task)
1381 return -ESRCH;
1382 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1383 put_task_struct(task);
1384 return simple_read_from_buffer(buf, count, ppos, numbuf, len);
1385 }
1387 static const struct file_operations proc_fail_nth_operations = {
1388 .read = proc_fail_nth_read,
1389 .write = proc_fail_nth_write,
1390 };
1391 #endif
1394 #ifdef CONFIG_SCHED_DEBUG
1395 /*
1396 * Print out various scheduling related per-task fields:
1397 */
1398 static int sched_show(struct seq_file *m, void *v)
1399 {
1400 struct inode *inode = m->private;
1401 struct pid_namespace *ns = proc_pid_ns(inode);
1402 struct task_struct *p;
1404 p = get_proc_task(inode);
1405 if (!p)
1406 return -ESRCH;
1407 proc_sched_show_task(p, ns, m);
1409 put_task_struct(p);
1411 return 0;
1412 }
1414 static ssize_t
1415 sched_write(struct file *file, const char __user *buf,
1416 size_t count, loff_t *offset)
1417 {
1418 struct inode *inode = file_inode(file);
1419 struct task_struct *p;
1421 p = get_proc_task(inode);
1422 if (!p)
1423 return -ESRCH;
1424 proc_sched_set_task(p);
1426 put_task_struct(p);
1428 return count;
1429 }
1431 static int sched_open(struct inode *inode, struct file *filp)
1432 {
1433 return single_open(filp, sched_show, inode);
1434 }
1436 static const struct file_operations proc_pid_sched_operations = {
1437 .open = sched_open,
1438 .read = seq_read,
1439 .write = sched_write,
1440 .llseek = seq_lseek,
1441 .release = single_release,
1442 };
1444 #endif
1446 #ifdef CONFIG_SCHED_AUTOGROUP
1447 /*
1448 * Print out autogroup related information:
1449 */
1450 static int sched_autogroup_show(struct seq_file *m, void *v)
1451 {
1452 struct inode *inode = m->private;
1453 struct task_struct *p;
1455 p = get_proc_task(inode);
1456 if (!p)
1457 return -ESRCH;
1458 proc_sched_autogroup_show_task(p, m);
1460 put_task_struct(p);
1462 return 0;
1463 }
1465 static ssize_t
1466 sched_autogroup_write(struct file *file, const char __user *buf,
1467 size_t count, loff_t *offset)
1468 {
1469 struct inode *inode = file_inode(file);
1470 struct task_struct *p;
1471 char buffer[PROC_NUMBUF];
1472 int nice;
1473 int err;
1475 memset(buffer, 0, sizeof(buffer));
1476 if (count > sizeof(buffer) - 1)
1477 count = sizeof(buffer) - 1;
1478 if (copy_from_user(buffer, buf, count))
1479 return -EFAULT;
1481 err = kstrtoint(strstrip(buffer), 0, &nice);
1482 if (err < 0)
1483 return err;
1485 p = get_proc_task(inode);
1486 if (!p)
1487 return -ESRCH;
1489 err = proc_sched_autogroup_set_nice(p, nice);
1490 if (err)
1491 count = err;
1493 put_task_struct(p);
1495 return count;
1496 }
1498 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1499 {
1500 int ret;
1502 ret = single_open(filp, sched_autogroup_show, NULL);
1503 if (!ret) {
1504 struct seq_file *m = filp->private_data;
1506 m->private = inode;
1507 }
1508 return ret;
1509 }
1511 static const struct file_operations proc_pid_sched_autogroup_operations = {
1512 .open = sched_autogroup_open,
1513 .read = seq_read,
1514 .write = sched_autogroup_write,
1515 .llseek = seq_lseek,
1516 .release = single_release,
1517 };
1519 #endif /* CONFIG_SCHED_AUTOGROUP */
1521 static ssize_t comm_write(struct file *file, const char __user *buf,
1522 size_t count, loff_t *offset)
1523 {
1524 struct inode *inode = file_inode(file);
1525 struct task_struct *p;
1526 char buffer[TASK_COMM_LEN];
1527 const size_t maxlen = sizeof(buffer) - 1;
1529 memset(buffer, 0, sizeof(buffer));
1530 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1531 return -EFAULT;
1533 p = get_proc_task(inode);
1534 if (!p)
1535 return -ESRCH;
1537 if (same_thread_group(current, p))
1538 set_task_comm(p, buffer);
1539 else
1540 count = -EINVAL;
1542 put_task_struct(p);
1544 return count;
1545 }
1547 static int comm_show(struct seq_file *m, void *v)
1548 {
1549 struct inode *inode = m->private;
1550 struct task_struct *p;
1552 p = get_proc_task(inode);
1553 if (!p)
1554 return -ESRCH;
1556 proc_task_name(m, p, false);
1557 seq_putc(m, '\n');
1559 put_task_struct(p);
1561 return 0;
1562 }
1564 static int comm_open(struct inode *inode, struct file *filp)
1565 {
1566 return single_open(filp, comm_show, inode);
1567 }
1569 static const struct file_operations proc_pid_set_comm_operations = {
1570 .open = comm_open,
1571 .read = seq_read,
1572 .write = comm_write,
1573 .llseek = seq_lseek,
1574 .release = single_release,
1575 };
1577 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1578 {
1579 struct task_struct *task;
1580 struct file *exe_file;
1582 task = get_proc_task(d_inode(dentry));
1583 if (!task)
1584 return -ENOENT;
1585 exe_file = get_task_exe_file(task);
1586 put_task_struct(task);
1587 if (exe_file) {
1588 *exe_path = exe_file->f_path;
1589 path_get(&exe_file->f_path);
1590 fput(exe_file);
1591 return 0;
1592 } else
1593 return -ENOENT;
1594 }
1596 static const char *proc_pid_get_link(struct dentry *dentry,
1597 struct inode *inode,
1598 struct delayed_call *done)
1599 {
1600 struct path path;
1601 int error = -EACCES;
1603 if (!dentry)
1604 return ERR_PTR(-ECHILD);
1606 /* Are we allowed to snoop on the tasks file descriptors? */
1607 if (!proc_fd_access_allowed(inode))
1608 goto out;
1610 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1611 if (error)
1612 goto out;
1614 nd_jump_link(&path);
1615 return NULL;
1616 out:
1617 return ERR_PTR(error);
1618 }
1620 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1621 {
1622 char *tmp = (char *)__get_free_page(GFP_KERNEL);
1623 char *pathname;
1624 int len;
1626 if (!tmp)
1627 return -ENOMEM;
1629 pathname = d_path(path, tmp, PAGE_SIZE);
1630 len = PTR_ERR(pathname);
1631 if (IS_ERR(pathname))
1632 goto out;
1633 len = tmp + PAGE_SIZE - 1 - pathname;
1635 if (len > buflen)
1636 len = buflen;
1637 if (copy_to_user(buffer, pathname, len))
1638 len = -EFAULT;
1639 out:
1640 free_page((unsigned long)tmp);
1641 return len;
1642 }
1644 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1645 {
1646 int error = -EACCES;
1647 struct inode *inode = d_inode(dentry);
1648 struct path path;
1650 /* Are we allowed to snoop on the tasks file descriptors? */
1651 if (!proc_fd_access_allowed(inode))
1652 goto out;
1654 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1655 if (error)
1656 goto out;
1658 error = do_proc_readlink(&path, buffer, buflen);
1659 path_put(&path);
1660 out:
1661 return error;
1662 }
1664 const struct inode_operations proc_pid_link_inode_operations = {
1665 .readlink = proc_pid_readlink,
1666 .get_link = proc_pid_get_link,
1667 .setattr = proc_setattr,
1668 };
1671 /* building an inode */
1673 void task_dump_owner(struct task_struct *task, umode_t mode,
1674 kuid_t *ruid, kgid_t *rgid)
1675 {
1676 /* Depending on the state of dumpable compute who should own a
1677 * proc file for a task.
1678 */
1679 const struct cred *cred;
1680 kuid_t uid;
1681 kgid_t gid;
1683 if (unlikely(task->flags & PF_KTHREAD)) {
1684 *ruid = GLOBAL_ROOT_UID;
1685 *rgid = GLOBAL_ROOT_GID;
1686 return;
1687 }
1689 /* Default to the tasks effective ownership */
1690 rcu_read_lock();
1691 cred = __task_cred(task);
1692 uid = cred->euid;
1693 gid = cred->egid;
1694 rcu_read_unlock();
1696 /*
1697 * Before the /proc/pid/status file was created the only way to read
1698 * the effective uid of a /process was to stat /proc/pid. Reading
1699 * /proc/pid/status is slow enough that procps and other packages
1700 * kept stating /proc/pid. To keep the rules in /proc simple I have
1701 * made this apply to all per process world readable and executable
1702 * directories.
1703 */
1704 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1705 struct mm_struct *mm;
1706 task_lock(task);
1707 mm = task->mm;
1708 /* Make non-dumpable tasks owned by some root */
1709 if (mm) {
1710 if (get_dumpable(mm) != SUID_DUMP_USER) {
1711 struct user_namespace *user_ns = mm->user_ns;
1713 uid = make_kuid(user_ns, 0);
1714 if (!uid_valid(uid))
1715 uid = GLOBAL_ROOT_UID;
1717 gid = make_kgid(user_ns, 0);
1718 if (!gid_valid(gid))
1719 gid = GLOBAL_ROOT_GID;
1720 }
1721 } else {
1722 uid = GLOBAL_ROOT_UID;
1723 gid = GLOBAL_ROOT_GID;
1724 }
1725 task_unlock(task);
1726 }
1727 *ruid = uid;
1728 *rgid = gid;
1729 }
1731 struct inode *proc_pid_make_inode(struct super_block * sb,
1732 struct task_struct *task, umode_t mode)
1733 {
1734 struct inode * inode;
1735 struct proc_inode *ei;
1737 /* We need a new inode */
1739 inode = new_inode(sb);
1740 if (!inode)
1741 goto out;
1743 /* Common stuff */
1744 ei = PROC_I(inode);
1745 inode->i_mode = mode;
1746 inode->i_ino = get_next_ino();
1747 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1748 inode->i_op = &proc_def_inode_operations;
1750 /*
1751 * grab the reference to task.
1752 */
1753 ei->pid = get_task_pid(task, PIDTYPE_PID);
1754 if (!ei->pid)
1755 goto out_unlock;
1757 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1758 security_task_to_inode(task, inode);
1760 out:
1761 return inode;
1763 out_unlock:
1764 iput(inode);
1765 return NULL;
1766 }
1768 int pid_getattr(const struct path *path, struct kstat *stat,
1769 u32 request_mask, unsigned int query_flags)
1770 {
1771 struct inode *inode = d_inode(path->dentry);
1772 struct pid_namespace *pid = proc_pid_ns(inode);
1773 struct task_struct *task;
1775 generic_fillattr(inode, stat);
1777 stat->uid = GLOBAL_ROOT_UID;
1778 stat->gid = GLOBAL_ROOT_GID;
1779 rcu_read_lock();
1780 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1781 if (task) {
1782 if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) {
1783 rcu_read_unlock();
1784 /*
1785 * This doesn't prevent learning whether PID exists,
1786 * it only makes getattr() consistent with readdir().
1787 */
1788 return -ENOENT;
1789 }
1790 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1791 }
1792 rcu_read_unlock();
1793 return 0;
1794 }
1796 /* dentry stuff */
1798 /*
1799 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
1800 */
1801 void pid_update_inode(struct task_struct *task, struct inode *inode)
1802 {
1803 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1805 inode->i_mode &= ~(S_ISUID | S_ISGID);
1806 security_task_to_inode(task, inode);
1807 }
1809 /*
1810 * Rewrite the inode's ownerships here because the owning task may have
1811 * performed a setuid(), etc.
1812 *
1813 */
1814 static int pid_revalidate(struct dentry *dentry, unsigned int flags)
1815 {
1816 struct inode *inode;
1817 struct task_struct *task;
1819 if (flags & LOOKUP_RCU)
1820 return -ECHILD;
1822 inode = d_inode(dentry);
1823 task = get_proc_task(inode);
1825 if (task) {
1826 pid_update_inode(task, inode);
1827 put_task_struct(task);
1828 return 1;
1829 }
1830 return 0;
1831 }
1833 static inline bool proc_inode_is_dead(struct inode *inode)
1834 {
1835 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1836 }
1838 int pid_delete_dentry(const struct dentry *dentry)
1839 {
1840 /* Is the task we represent dead?
1841 * If so, then don't put the dentry on the lru list,
1842 * kill it immediately.
1843 */
1844 return proc_inode_is_dead(d_inode(dentry));
1845 }
1847 const struct dentry_operations pid_dentry_operations =
1848 {
1849 .d_revalidate = pid_revalidate,
1850 .d_delete = pid_delete_dentry,
1851 };
1853 /* Lookups */
1855 /*
1856 * Fill a directory entry.
1857 *
1858 * If possible create the dcache entry and derive our inode number and
1859 * file type from dcache entry.
1860 *
1861 * Since all of the proc inode numbers are dynamically generated, the inode
1862 * numbers do not exist until the inode is cache. This means creating the
1863 * the dcache entry in readdir is necessary to keep the inode numbers
1864 * reported by readdir in sync with the inode numbers reported
1865 * by stat.
1866 */
1867 bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1868 const char *name, unsigned int len,
1869 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1870 {
1871 struct dentry *child, *dir = file->f_path.dentry;
1872 struct qstr qname = QSTR_INIT(name, len);
1873 struct inode *inode;
1874 unsigned type = DT_UNKNOWN;
1875 ino_t ino = 1;
1877 child = d_hash_and_lookup(dir, &qname);
1878 if (!child) {
1879 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
1880 child = d_alloc_parallel(dir, &qname, &wq);
1881 if (IS_ERR(child))
1882 goto end_instantiate;
1883 if (d_in_lookup(child)) {
1884 struct dentry *res;
1885 res = instantiate(child, task, ptr);
1886 d_lookup_done(child);
1887 if (unlikely(res)) {
1888 dput(child);
1889 child = res;
1890 if (IS_ERR(child))
1891 goto end_instantiate;
1892 }
1893 }
1894 }
1895 inode = d_inode(child);
1896 ino = inode->i_ino;
1897 type = inode->i_mode >> 12;
1898 dput(child);
1899 end_instantiate:
1900 return dir_emit(ctx, name, len, ino, type);
1901 }
1903 /*
1904 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1905 * which represent vma start and end addresses.
1906 */
1907 static int dname_to_vma_addr(struct dentry *dentry,
1908 unsigned long *start, unsigned long *end)
1909 {
1910 const char *str = dentry->d_name.name;
1911 unsigned long long sval, eval;
1912 unsigned int len;
1914 if (str[0] == '0' && str[1] != '-')
1915 return -EINVAL;
1916 len = _parse_integer(str, 16, &sval);
1917 if (len & KSTRTOX_OVERFLOW)
1918 return -EINVAL;
1919 if (sval != (unsigned long)sval)
1920 return -EINVAL;
1921 str += len;
1923 if (*str != '-')
1924 return -EINVAL;
1925 str++;
1927 if (str[0] == '0' && str[1])
1928 return -EINVAL;
1929 len = _parse_integer(str, 16, &eval);
1930 if (len & KSTRTOX_OVERFLOW)
1931 return -EINVAL;
1932 if (eval != (unsigned long)eval)
1933 return -EINVAL;
1934 str += len;
1936 if (*str != '\0')
1937 return -EINVAL;
1939 *start = sval;
1940 *end = eval;
1942 return 0;
1943 }
1945 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1946 {
1947 unsigned long vm_start, vm_end;
1948 bool exact_vma_exists = false;
1949 struct mm_struct *mm = NULL;
1950 struct task_struct *task;
1951 struct inode *inode;
1952 int status = 0;
1954 if (flags & LOOKUP_RCU)
1955 return -ECHILD;
1957 inode = d_inode(dentry);
1958 task = get_proc_task(inode);
1959 if (!task)
1960 goto out_notask;
1962 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
1963 if (IS_ERR_OR_NULL(mm))
1964 goto out;
1966 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1967 down_read(&mm->mmap_sem);
1968 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1969 up_read(&mm->mmap_sem);
1970 }
1972 mmput(mm);
1974 if (exact_vma_exists) {
1975 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1977 security_task_to_inode(task, inode);
1978 status = 1;
1979 }
1981 out:
1982 put_task_struct(task);
1984 out_notask:
1985 return status;
1986 }
1988 static const struct dentry_operations tid_map_files_dentry_operations = {
1989 .d_revalidate = map_files_d_revalidate,
1990 .d_delete = pid_delete_dentry,
1991 };
1993 static int map_files_get_link(struct dentry *dentry, struct path *path)
1994 {
1995 unsigned long vm_start, vm_end;
1996 struct vm_area_struct *vma;
1997 struct task_struct *task;
1998 struct mm_struct *mm;
1999 int rc;
2001 rc = -ENOENT;
2002 task = get_proc_task(d_inode(dentry));
2003 if (!task)
2004 goto out;
2006 mm = get_task_mm(task);
2007 put_task_struct(task);
2008 if (!mm)
2009 goto out;
2011 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2012 if (rc)
2013 goto out_mmput;
2015 rc = -ENOENT;
2016 down_read(&mm->mmap_sem);
2017 vma = find_exact_vma(mm, vm_start, vm_end);
2018 if (vma && vma->vm_file) {
2019 *path = vma->vm_file->f_path;
2020 path_get(path);
2021 rc = 0;
2022 }
2023 up_read(&mm->mmap_sem);
2025 out_mmput:
2026 mmput(mm);
2027 out:
2028 return rc;
2029 }
2031 struct map_files_info {
2032 unsigned long start;
2033 unsigned long end;
2034 fmode_t mode;
2035 };
2037 /*
2038 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
2039 * symlinks may be used to bypass permissions on ancestor directories in the
2040 * path to the file in question.
2041 */
2042 static const char *
2043 proc_map_files_get_link(struct dentry *dentry,
2044 struct inode *inode,
2045 struct delayed_call *done)
2046 {
2047 if (!capable(CAP_SYS_ADMIN))
2048 return ERR_PTR(-EPERM);
2050 return proc_pid_get_link(dentry, inode, done);
2051 }
2053 /*
2054 * Identical to proc_pid_link_inode_operations except for get_link()
2055 */
2056 static const struct inode_operations proc_map_files_link_inode_operations = {
2057 .readlink = proc_pid_readlink,
2058 .get_link = proc_map_files_get_link,
2059 .setattr = proc_setattr,
2060 };
2062 static struct dentry *
2063 proc_map_files_instantiate(struct dentry *dentry,
2064 struct task_struct *task, const void *ptr)
2065 {
2066 fmode_t mode = (fmode_t)(unsigned long)ptr;
2067 struct proc_inode *ei;
2068 struct inode *inode;
2070 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
2071 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2072 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2073 if (!inode)
2074 return ERR_PTR(-ENOENT);
2076 ei = PROC_I(inode);
2077 ei->op.proc_get_link = map_files_get_link;
2079 inode->i_op = &proc_map_files_link_inode_operations;
2080 inode->i_size = 64;
2082 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2083 return d_splice_alias(inode, dentry);
2084 }
2086 static struct dentry *proc_map_files_lookup(struct inode *dir,
2087 struct dentry *dentry, unsigned int flags)
2088 {
2089 unsigned long vm_start, vm_end;
2090 struct vm_area_struct *vma;
2091 struct task_struct *task;
2092 struct dentry *result;
2093 struct mm_struct *mm;
2095 result = ERR_PTR(-ENOENT);
2096 task = get_proc_task(dir);
2097 if (!task)
2098 goto out;
2100 result = ERR_PTR(-EACCES);
2101 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2102 goto out_put_task;
2104 result = ERR_PTR(-ENOENT);
2105 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2106 goto out_put_task;
2108 mm = get_task_mm(task);
2109 if (!mm)
2110 goto out_put_task;
2112 down_read(&mm->mmap_sem);
2113 vma = find_exact_vma(mm, vm_start, vm_end);
2114 if (!vma)
2115 goto out_no_vma;
2117 if (vma->vm_file)
2118 result = proc_map_files_instantiate(dentry, task,
2119 (void *)(unsigned long)vma->vm_file->f_mode);
2121 out_no_vma:
2122 up_read(&mm->mmap_sem);
2123 mmput(mm);
2124 out_put_task:
2125 put_task_struct(task);
2126 out:
2127 return result;
2128 }
2130 static const struct inode_operations proc_map_files_inode_operations = {
2131 .lookup = proc_map_files_lookup,
2132 .permission = proc_fd_permission,
2133 .setattr = proc_setattr,
2134 };
2136 static int
2137 proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2138 {
2139 struct vm_area_struct *vma;
2140 struct task_struct *task;
2141 struct mm_struct *mm;
2142 unsigned long nr_files, pos, i;
2143 struct flex_array *fa = NULL;
2144 struct map_files_info info;
2145 struct map_files_info *p;
2146 int ret;
2148 ret = -ENOENT;
2149 task = get_proc_task(file_inode(file));
2150 if (!task)
2151 goto out;
2153 ret = -EACCES;
2154 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2155 goto out_put_task;
2157 ret = 0;
2158 if (!dir_emit_dots(file, ctx))
2159 goto out_put_task;
2161 mm = get_task_mm(task);
2162 if (!mm)
2163 goto out_put_task;
2164 down_read(&mm->mmap_sem);
2166 nr_files = 0;
2168 /*
2169 * We need two passes here:
2170 *
2171 * 1) Collect vmas of mapped files with mmap_sem taken
2172 * 2) Release mmap_sem and instantiate entries
2173 *
2174 * otherwise we get lockdep complained, since filldir()
2175 * routine might require mmap_sem taken in might_fault().
2176 */
2178 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2179 if (vma->vm_file && ++pos > ctx->pos)
2180 nr_files++;
2181 }
2183 if (nr_files) {
2184 fa = flex_array_alloc(sizeof(info), nr_files,
2185 GFP_KERNEL);
2186 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2187 GFP_KERNEL)) {
2188 ret = -ENOMEM;
2189 if (fa)
2190 flex_array_free(fa);
2191 up_read(&mm->mmap_sem);
2192 mmput(mm);
2193 goto out_put_task;
2194 }
2195 for (i = 0, vma = mm->mmap, pos = 2; vma;
2196 vma = vma->vm_next) {
2197 if (!vma->vm_file)
2198 continue;
2199 if (++pos <= ctx->pos)
2200 continue;
2202 info.start = vma->vm_start;
2203 info.end = vma->vm_end;
2204 info.mode = vma->vm_file->f_mode;
2205 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2206 BUG();
2207 }
2208 }
2209 up_read(&mm->mmap_sem);
2210 mmput(mm);
2212 for (i = 0; i < nr_files; i++) {
2213 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2214 unsigned int len;
2216 p = flex_array_get(fa, i);
2217 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2218 if (!proc_fill_cache(file, ctx,
2219 buf, len,
2220 proc_map_files_instantiate,
2221 task,
2222 (void *)(unsigned long)p->mode))
2223 break;
2224 ctx->pos++;
2225 }
2226 if (fa)
2227 flex_array_free(fa);
2229 out_put_task:
2230 put_task_struct(task);
2231 out:
2232 return ret;
2233 }
2235 static const struct file_operations proc_map_files_operations = {
2236 .read = generic_read_dir,
2237 .iterate_shared = proc_map_files_readdir,
2238 .llseek = generic_file_llseek,
2239 };
2241 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2242 struct timers_private {
2243 struct pid *pid;
2244 struct task_struct *task;
2245 struct sighand_struct *sighand;
2246 struct pid_namespace *ns;
2247 unsigned long flags;
2248 };
2250 static void *timers_start(struct seq_file *m, loff_t *pos)
2251 {
2252 struct timers_private *tp = m->private;
2254 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2255 if (!tp->task)
2256 return ERR_PTR(-ESRCH);
2258 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2259 if (!tp->sighand)
2260 return ERR_PTR(-ESRCH);
2262 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2263 }
2265 static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2266 {
2267 struct timers_private *tp = m->private;
2268 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2269 }
2271 static void timers_stop(struct seq_file *m, void *v)
2272 {
2273 struct timers_private *tp = m->private;
2275 if (tp->sighand) {
2276 unlock_task_sighand(tp->task, &tp->flags);
2277 tp->sighand = NULL;
2278 }
2280 if (tp->task) {
2281 put_task_struct(tp->task);
2282 tp->task = NULL;
2283 }
2284 }
2286 static int show_timer(struct seq_file *m, void *v)
2287 {
2288 struct k_itimer *timer;
2289 struct timers_private *tp = m->private;
2290 int notify;
2291 static const char * const nstr[] = {
2292 [SIGEV_SIGNAL] = "signal",
2293 [SIGEV_NONE] = "none",
2294 [SIGEV_THREAD] = "thread",
2295 };
2297 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2298 notify = timer->it_sigev_notify;
2300 seq_printf(m, "ID: %d\n", timer->it_id);
2301 seq_printf(m, "signal: %d/%px\n",
2302 timer->sigq->info.si_signo,
2303 timer->sigq->info.si_value.sival_ptr);
2304 seq_printf(m, "notify: %s/%s.%d\n",
2305 nstr[notify & ~SIGEV_THREAD_ID],
2306 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2307 pid_nr_ns(timer->it_pid, tp->ns));
2308 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2310 return 0;
2311 }
2313 static const struct seq_operations proc_timers_seq_ops = {
2314 .start = timers_start,
2315 .next = timers_next,
2316 .stop = timers_stop,
2317 .show = show_timer,
2318 };
2320 static int proc_timers_open(struct inode *inode, struct file *file)
2321 {
2322 struct timers_private *tp;
2324 tp = __seq_open_private(file, &proc_timers_seq_ops,
2325 sizeof(struct timers_private));
2326 if (!tp)
2327 return -ENOMEM;
2329 tp->pid = proc_pid(inode);
2330 tp->ns = proc_pid_ns(inode);
2331 return 0;
2332 }
2334 static const struct file_operations proc_timers_operations = {
2335 .open = proc_timers_open,
2336 .read = seq_read,
2337 .llseek = seq_lseek,
2338 .release = seq_release_private,
2339 };
2340 #endif
2342 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2343 size_t count, loff_t *offset)
2344 {
2345 struct inode *inode = file_inode(file);
2346 struct task_struct *p;
2347 u64 slack_ns;
2348 int err;
2350 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2351 if (err < 0)
2352 return err;
2354 p = get_proc_task(inode);
2355 if (!p)
2356 return -ESRCH;
2358 if (p != current) {
2359 if (!capable(CAP_SYS_NICE)) {
2360 count = -EPERM;
2361 goto out;
2362 }
2364 err = security_task_setscheduler(p);
2365 if (err) {
2366 count = err;
2367 goto out;
2368 }
2369 }
2371 task_lock(p);
2372 if (slack_ns == 0)
2373 p->timer_slack_ns = p->default_timer_slack_ns;
2374 else
2375 p->timer_slack_ns = slack_ns;
2376 task_unlock(p);
2378 out:
2379 put_task_struct(p);
2381 return count;
2382 }
2384 static int timerslack_ns_show(struct seq_file *m, void *v)
2385 {
2386 struct inode *inode = m->private;
2387 struct task_struct *p;
2388 int err = 0;
2390 p = get_proc_task(inode);
2391 if (!p)
2392 return -ESRCH;
2394 if (p != current) {
2396 if (!capable(CAP_SYS_NICE)) {
2397 err = -EPERM;
2398 goto out;
2399 }
2400 err = security_task_getscheduler(p);
2401 if (err)
2402 goto out;
2403 }
2405 task_lock(p);
2406 seq_printf(m, "%llu\n", p->timer_slack_ns);
2407 task_unlock(p);
2409 out:
2410 put_task_struct(p);
2412 return err;
2413 }
2415 static int timerslack_ns_open(struct inode *inode, struct file *filp)
2416 {
2417 return single_open(filp, timerslack_ns_show, inode);
2418 }
2420 static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2421 .open = timerslack_ns_open,
2422 .read = seq_read,
2423 .write = timerslack_ns_write,
2424 .llseek = seq_lseek,
2425 .release = single_release,
2426 };
2428 static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2429 struct task_struct *task, const void *ptr)
2430 {
2431 const struct pid_entry *p = ptr;
2432 struct inode *inode;
2433 struct proc_inode *ei;
2435 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
2436 if (!inode)
2437 return ERR_PTR(-ENOENT);
2439 ei = PROC_I(inode);
2440 if (S_ISDIR(inode->i_mode))
2441 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2442 if (p->iop)
2443 inode->i_op = p->iop;
2444 if (p->fop)
2445 inode->i_fop = p->fop;
2446 ei->op = p->op;
2447 pid_update_inode(task, inode);
2448 d_set_d_op(dentry, &pid_dentry_operations);
2449 return d_splice_alias(inode, dentry);
2450 }
2452 static struct dentry *proc_pident_lookup(struct inode *dir,
2453 struct dentry *dentry,
2454 const struct pid_entry *ents,
2455 unsigned int nents)
2456 {
2457 struct task_struct *task = get_proc_task(dir);
2458 const struct pid_entry *p, *last;
2459 struct dentry *res = ERR_PTR(-ENOENT);
2461 if (!task)
2462 goto out_no_task;
2464 /*
2465 * Yes, it does not scale. And it should not. Don't add
2466 * new entries into /proc/<tgid>/ without very good reasons.
2467 */
2468 last = &ents[nents];
2469 for (p = ents; p < last; p++) {
2470 if (p->len != dentry->d_name.len)
2471 continue;
2472 if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2473 res = proc_pident_instantiate(dentry, task, p);
2474 break;
2475 }
2476 }
2477 put_task_struct(task);
2478 out_no_task:
2479 return res;
2480 }
2482 static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2483 const struct pid_entry *ents, unsigned int nents)
2484 {
2485 struct task_struct *task = get_proc_task(file_inode(file));
2486 const struct pid_entry *p;
2488 if (!task)
2489 return -ENOENT;
2491 if (!dir_emit_dots(file, ctx))
2492 goto out;
2494 if (ctx->pos >= nents + 2)
2495 goto out;
2497 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2498 if (!proc_fill_cache(file, ctx, p->name, p->len,
2499 proc_pident_instantiate, task, p))
2500 break;
2501 ctx->pos++;
2502 }
2503 out:
2504 put_task_struct(task);
2505 return 0;
2506 }
2508 #ifdef CONFIG_SECURITY
2509 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2510 size_t count, loff_t *ppos)
2511 {
2512 struct inode * inode = file_inode(file);
2513 char *p = NULL;
2514 ssize_t length;
2515 struct task_struct *task = get_proc_task(inode);
2517 if (!task)
2518 return -ESRCH;
2520 length = security_getprocattr(task,
2521 (char*)file->f_path.dentry->d_name.name,
2522 &p);
2523 put_task_struct(task);
2524 if (length > 0)
2525 length = simple_read_from_buffer(buf, count, ppos, p, length);
2526 kfree(p);
2527 return length;
2528 }
2530 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2531 size_t count, loff_t *ppos)
2532 {
2533 struct inode * inode = file_inode(file);
2534 struct task_struct *task;
2535 void *page;
2536 int rv;
2538 rcu_read_lock();
2539 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2540 if (!task) {
2541 rcu_read_unlock();
2542 return -ESRCH;
2543 }
2544 /* A task may only write its own attributes. */
2545 if (current != task) {
2546 rcu_read_unlock();
2547 return -EACCES;
2548 }
2549 rcu_read_unlock();
2551 if (count > PAGE_SIZE)
2552 count = PAGE_SIZE;
2554 /* No partial writes. */
2555 if (*ppos != 0)
2556 return -EINVAL;
2558 page = memdup_user(buf, count);
2559 if (IS_ERR(page)) {
2560 rv = PTR_ERR(page);
2561 goto out;
2562 }
2564 /* Guard against adverse ptrace interaction */
2565 rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex);
2566 if (rv < 0)
2567 goto out_free;
2569 rv = security_setprocattr(file->f_path.dentry->d_name.name, page, count);
2570 mutex_unlock(¤t->signal->cred_guard_mutex);
2571 out_free:
2572 kfree(page);
2573 out:
2574 return rv;
2575 }
2577 static const struct file_operations proc_pid_attr_operations = {
2578 .read = proc_pid_attr_read,
2579 .write = proc_pid_attr_write,
2580 .llseek = generic_file_llseek,
2581 };
2583 static const struct pid_entry attr_dir_stuff[] = {
2584 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2585 REG("prev", S_IRUGO, proc_pid_attr_operations),
2586 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2587 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2588 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2589 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2590 };
2592 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2593 {
2594 return proc_pident_readdir(file, ctx,
2595 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2596 }
2598 static const struct file_operations proc_attr_dir_operations = {
2599 .read = generic_read_dir,
2600 .iterate_shared = proc_attr_dir_readdir,
2601 .llseek = generic_file_llseek,
2602 };
2604 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2605 struct dentry *dentry, unsigned int flags)
2606 {
2607 return proc_pident_lookup(dir, dentry,
2608 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2609 }
2611 static const struct inode_operations proc_attr_dir_inode_operations = {
2612 .lookup = proc_attr_dir_lookup,
2613 .getattr = pid_getattr,
2614 .setattr = proc_setattr,
2615 };
2617 #endif
2619 #ifdef CONFIG_ELF_CORE
2620 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2621 size_t count, loff_t *ppos)
2622 {
2623 struct task_struct *task = get_proc_task(file_inode(file));
2624 struct mm_struct *mm;
2625 char buffer[PROC_NUMBUF];
2626 size_t len;
2627 int ret;
2629 if (!task)
2630 return -ESRCH;
2632 ret = 0;
2633 mm = get_task_mm(task);
2634 if (mm) {
2635 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2636 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2637 MMF_DUMP_FILTER_SHIFT));
2638 mmput(mm);
2639 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2640 }
2642 put_task_struct(task);
2644 return ret;
2645 }
2647 static ssize_t proc_coredump_filter_write(struct file *file,
2648 const char __user *buf,
2649 size_t count,
2650 loff_t *ppos)
2651 {
2652 struct task_struct *task;
2653 struct mm_struct *mm;
2654 unsigned int val;
2655 int ret;
2656 int i;
2657 unsigned long mask;
2659 ret = kstrtouint_from_user(buf, count, 0, &val);
2660 if (ret < 0)
2661 return ret;
2663 ret = -ESRCH;
2664 task = get_proc_task(file_inode(file));
2665 if (!task)
2666 goto out_no_task;
2668 mm = get_task_mm(task);
2669 if (!mm)
2670 goto out_no_mm;
2671 ret = 0;
2673 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2674 if (val & mask)
2675 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2676 else
2677 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2678 }
2680 mmput(mm);
2681 out_no_mm:
2682 put_task_struct(task);
2683 out_no_task:
2684 if (ret < 0)
2685 return ret;
2686 return count;
2687 }
2689 static const struct file_operations proc_coredump_filter_operations = {
2690 .read = proc_coredump_filter_read,
2691 .write = proc_coredump_filter_write,
2692 .llseek = generic_file_llseek,
2693 };
2694 #endif
2696 #ifdef CONFIG_TASK_IO_ACCOUNTING
2697 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2698 {
2699 struct task_io_accounting acct = task->ioac;
2700 unsigned long flags;
2701 int result;
2703 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2704 if (result)
2705 return result;
2707 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2708 result = -EACCES;
2709 goto out_unlock;
2710 }
2712 if (whole && lock_task_sighand(task, &flags)) {
2713 struct task_struct *t = task;
2715 task_io_accounting_add(&acct, &task->signal->ioac);
2716 while_each_thread(task, t)
2717 task_io_accounting_add(&acct, &t->ioac);
2719 unlock_task_sighand(task, &flags);
2720 }
2721 seq_printf(m,
2722 "rchar: %llu\n"
2723 "wchar: %llu\n"
2724 "syscr: %llu\n"
2725 "syscw: %llu\n"
2726 "read_bytes: %llu\n"
2727 "write_bytes: %llu\n"
2728 "cancelled_write_bytes: %llu\n",
2729 (unsigned long long)acct.rchar,
2730 (unsigned long long)acct.wchar,
2731 (unsigned long long)acct.syscr,
2732 (unsigned long long)acct.syscw,
2733 (unsigned long long)acct.read_bytes,
2734 (unsigned long long)acct.write_bytes,
2735 (unsigned long long)acct.cancelled_write_bytes);
2736 result = 0;
2738 out_unlock:
2739 mutex_unlock(&task->signal->cred_guard_mutex);
2740 return result;
2741 }
2743 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2744 struct pid *pid, struct task_struct *task)
2745 {
2746 return do_io_accounting(task, m, 0);
2747 }
2749 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2750 struct pid *pid, struct task_struct *task)
2751 {
2752 return do_io_accounting(task, m, 1);
2753 }
2754 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2756 #ifdef CONFIG_USER_NS
2757 static int proc_id_map_open(struct inode *inode, struct file *file,
2758 const struct seq_operations *seq_ops)
2759 {
2760 struct user_namespace *ns = NULL;
2761 struct task_struct *task;
2762 struct seq_file *seq;
2763 int ret = -EINVAL;
2765 task = get_proc_task(inode);
2766 if (task) {
2767 rcu_read_lock();
2768 ns = get_user_ns(task_cred_xxx(task, user_ns));
2769 rcu_read_unlock();
2770 put_task_struct(task);
2771 }
2772 if (!ns)
2773 goto err;
2775 ret = seq_open(file, seq_ops);
2776 if (ret)
2777 goto err_put_ns;
2779 seq = file->private_data;
2780 seq->private = ns;
2782 return 0;
2783 err_put_ns:
2784 put_user_ns(ns);
2785 err:
2786 return ret;
2787 }
2789 static int proc_id_map_release(struct inode *inode, struct file *file)
2790 {
2791 struct seq_file *seq = file->private_data;
2792 struct user_namespace *ns = seq->private;
2793 put_user_ns(ns);
2794 return seq_release(inode, file);
2795 }
2797 static int proc_uid_map_open(struct inode *inode, struct file *file)
2798 {
2799 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2800 }
2802 static int proc_gid_map_open(struct inode *inode, struct file *file)
2803 {
2804 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2805 }
2807 static int proc_projid_map_open(struct inode *inode, struct file *file)
2808 {
2809 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2810 }
2812 static const struct file_operations proc_uid_map_operations = {
2813 .open = proc_uid_map_open,
2814 .write = proc_uid_map_write,
2815 .read = seq_read,
2816 .llseek = seq_lseek,
2817 .release = proc_id_map_release,
2818 };
2820 static const struct file_operations proc_gid_map_operations = {
2821 .open = proc_gid_map_open,
2822 .write = proc_gid_map_write,
2823 .read = seq_read,
2824 .llseek = seq_lseek,
2825 .release = proc_id_map_release,
2826 };
2828 static const struct file_operations proc_projid_map_operations = {
2829 .open = proc_projid_map_open,
2830 .write = proc_projid_map_write,
2831 .read = seq_read,
2832 .llseek = seq_lseek,
2833 .release = proc_id_map_release,
2834 };
2836 static int proc_setgroups_open(struct inode *inode, struct file *file)
2837 {
2838 struct user_namespace *ns = NULL;
2839 struct task_struct *task;
2840 int ret;
2842 ret = -ESRCH;
2843 task = get_proc_task(inode);
2844 if (task) {
2845 rcu_read_lock();
2846 ns = get_user_ns(task_cred_xxx(task, user_ns));
2847 rcu_read_unlock();
2848 put_task_struct(task);
2849 }
2850 if (!ns)
2851 goto err;
2853 if (file->f_mode & FMODE_WRITE) {
2854 ret = -EACCES;
2855 if (!ns_capable(ns, CAP_SYS_ADMIN))
2856 goto err_put_ns;
2857 }
2859 ret = single_open(file, &proc_setgroups_show, ns);
2860 if (ret)
2861 goto err_put_ns;
2863 return 0;
2864 err_put_ns:
2865 put_user_ns(ns);
2866 err:
2867 return ret;
2868 }
2870 static int proc_setgroups_release(struct inode *inode, struct file *file)
2871 {
2872 struct seq_file *seq = file->private_data;
2873 struct user_namespace *ns = seq->private;
2874 int ret = single_release(inode, file);
2875 put_user_ns(ns);
2876 return ret;
2877 }
2879 static const struct file_operations proc_setgroups_operations = {
2880 .open = proc_setgroups_open,
2881 .write = proc_setgroups_write,
2882 .read = seq_read,
2883 .llseek = seq_lseek,
2884 .release = proc_setgroups_release,
2885 };
2886 #endif /* CONFIG_USER_NS */
2888 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2889 struct pid *pid, struct task_struct *task)
2890 {
2891 int err = lock_trace(task);
2892 if (!err) {
2893 seq_printf(m, "%08x\n", task->personality);
2894 unlock_trace(task);
2895 }
2896 return err;
2897 }
2899 #ifdef CONFIG_LIVEPATCH
2900 static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
2901 struct pid *pid, struct task_struct *task)
2902 {
2903 seq_printf(m, "%d\n", task->patch_state);
2904 return 0;
2905 }
2906 #endif /* CONFIG_LIVEPATCH */
2908 /*
2909 * Thread groups
2910 */
2911 static const struct file_operations proc_task_operations;
2912 static const struct inode_operations proc_task_inode_operations;
2914 static const struct pid_entry tgid_base_stuff[] = {
2915 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2916 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2917 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2918 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2919 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2920 #ifdef CONFIG_NET
2921 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2922 #endif
2923 REG("environ", S_IRUSR, proc_environ_operations),
2924 REG("auxv", S_IRUSR, proc_auxv_operations),
2925 ONE("status", S_IRUGO, proc_pid_status),
2926 ONE("personality", S_IRUSR, proc_pid_personality),
2927 ONE("limits", S_IRUGO, proc_pid_limits),
2928 #ifdef CONFIG_SCHED_DEBUG
2929 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2930 #endif
2931 #ifdef CONFIG_SCHED_AUTOGROUP
2932 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2933 #endif
2934 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2935 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2936 ONE("syscall", S_IRUSR, proc_pid_syscall),
2937 #endif
2938 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
2939 ONE("stat", S_IRUGO, proc_tgid_stat),
2940 ONE("statm", S_IRUGO, proc_pid_statm),
2941 REG("maps", S_IRUGO, proc_pid_maps_operations),
2942 #ifdef CONFIG_NUMA
2943 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
2944 #endif
2945 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2946 LNK("cwd", proc_cwd_link),
2947 LNK("root", proc_root_link),
2948 LNK("exe", proc_exe_link),
2949 REG("mounts", S_IRUGO, proc_mounts_operations),
2950 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2951 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2952 #ifdef CONFIG_PROC_PAGE_MONITOR
2953 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2954 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
2955 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
2956 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2957 #endif
2958 #ifdef CONFIG_SECURITY
2959 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2960 #endif
2961 #ifdef CONFIG_KALLSYMS
2962 ONE("wchan", S_IRUGO, proc_pid_wchan),
2963 #endif
2964 #ifdef CONFIG_STACKTRACE
2965 ONE("stack", S_IRUSR, proc_pid_stack),
2966 #endif
2967 #ifdef CONFIG_SCHED_INFO
2968 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
2969 #endif
2970 #ifdef CONFIG_LATENCYTOP
2971 REG("latency", S_IRUGO, proc_lstats_operations),
2972 #endif
2973 #ifdef CONFIG_PROC_PID_CPUSET
2974 ONE("cpuset", S_IRUGO, proc_cpuset_show),
2975 #endif
2976 #ifdef CONFIG_CGROUPS
2977 ONE("cgroup", S_IRUGO, proc_cgroup_show),
2978 #endif
2979 ONE("oom_score", S_IRUGO, proc_oom_score),
2980 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
2981 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2982 #ifdef CONFIG_AUDITSYSCALL
2983 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2984 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2985 #endif
2986 #ifdef CONFIG_FAULT_INJECTION
2987 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2988 REG("fail-nth", 0644, proc_fail_nth_operations),
2989 #endif
2990 #ifdef CONFIG_ELF_CORE
2991 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2992 #endif
2993 #ifdef CONFIG_TASK_IO_ACCOUNTING
2994 ONE("io", S_IRUSR, proc_tgid_io_accounting),
2995 #endif
2996 #ifdef CONFIG_USER_NS
2997 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
2998 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
2999 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3000 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3001 #endif
3002 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3003 REG("timers", S_IRUGO, proc_timers_operations),
3004 #endif
3005 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3006 #ifdef CONFIG_LIVEPATCH
3007 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3008 #endif
3009 };
3011 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3012 {
3013 return proc_pident_readdir(file, ctx,
3014 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3015 }
3017 static const struct file_operations proc_tgid_base_operations = {
3018 .read = generic_read_dir,
3019 .iterate_shared = proc_tgid_base_readdir,
3020 .llseek = generic_file_llseek,
3021 };
3023 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3024 {
3025 return proc_pident_lookup(dir, dentry,
3026 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3027 }
3029 static const struct inode_operations proc_tgid_base_inode_operations = {
3030 .lookup = proc_tgid_base_lookup,
3031 .getattr = pid_getattr,
3032 .setattr = proc_setattr,
3033 .permission = proc_pid_permission,
3034 };
3036 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
3037 {
3038 struct dentry *dentry, *leader, *dir;
3039 char buf[10 + 1];
3040 struct qstr name;
3042 name.name = buf;
3043 name.len = snprintf(buf, sizeof(buf), "%u", pid);
3044 /* no ->d_hash() rejects on procfs */
3045 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
3046 if (dentry) {
3047 d_invalidate(dentry);
3048 dput(dentry);
3049 }
3051 if (pid == tgid)
3052 return;
3054 name.name = buf;
3055 name.len = snprintf(buf, sizeof(buf), "%u", tgid);
3056 leader = d_hash_and_lookup(mnt->mnt_root, &name);
3057 if (!leader)
3058 goto out;
3060 name.name = "task";
3061 name.len = strlen(name.name);
3062 dir = d_hash_and_lookup(leader, &name);
3063 if (!dir)
3064 goto out_put_leader;
3066 name.name = buf;
3067 name.len = snprintf(buf, sizeof(buf), "%u", pid);
3068 dentry = d_hash_and_lookup(dir, &name);
3069 if (dentry) {
3070 d_invalidate(dentry);
3071 dput(dentry);
3072 }
3074 dput(dir);
3075 out_put_leader:
3076 dput(leader);
3077 out:
3078 return;
3079 }
3081 /**
3082 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3083 * @task: task that should be flushed.
3084 *
3085 * When flushing dentries from proc, one needs to flush them from global
3086 * proc (proc_mnt) and from all the namespaces' procs this task was seen
3087 * in. This call is supposed to do all of this job.
3088 *
3089 * Looks in the dcache for
3090 * /proc/@pid
3091 * /proc/@tgid/task/@pid
3092 * if either directory is present flushes it and all of it'ts children
3093 * from the dcache.
3094 *
3095 * It is safe and reasonable to cache /proc entries for a task until
3096 * that task exits. After that they just clog up the dcache with
3097 * useless entries, possibly causing useful dcache entries to be
3098 * flushed instead. This routine is proved to flush those useless
3099 * dcache entries at process exit time.
3100 *
3101 * NOTE: This routine is just an optimization so it does not guarantee
3102 * that no dcache entries will exist at process exit time it
3103 * just makes it very unlikely that any will persist.
3104 */
3106 void proc_flush_task(struct task_struct *task)
3107 {
3108 int i;
3109 struct pid *pid, *tgid;
3110 struct upid *upid;
3112 pid = task_pid(task);
3113 tgid = task_tgid(task);
3115 for (i = 0; i <= pid->level; i++) {
3116 upid = &pid->numbers[i];
3117 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3118 tgid->numbers[i].nr);
3119 }
3120 }
3122 static struct dentry *proc_pid_instantiate(struct dentry * dentry,
3123 struct task_struct *task, const void *ptr)
3124 {
3125 struct inode *inode;
3127 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3128 if (!inode)
3129 return ERR_PTR(-ENOENT);
3131 inode->i_op = &proc_tgid_base_inode_operations;
3132 inode->i_fop = &proc_tgid_base_operations;
3133 inode->i_flags|=S_IMMUTABLE;
3135 set_nlink(inode, nlink_tgid);
3136 pid_update_inode(task, inode);
3138 d_set_d_op(dentry, &pid_dentry_operations);
3139 return d_splice_alias(inode, dentry);
3140 }
3142 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3143 {
3144 struct task_struct *task;
3145 unsigned tgid;
3146 struct pid_namespace *ns;
3147 struct dentry *result = ERR_PTR(-ENOENT);
3149 tgid = name_to_int(&dentry->d_name);
3150 if (tgid == ~0U)
3151 goto out;
3153 ns = dentry->d_sb->s_fs_info;
3154 rcu_read_lock();
3155 task = find_task_by_pid_ns(tgid, ns);
3156 if (task)
3157 get_task_struct(task);
3158 rcu_read_unlock();
3159 if (!task)
3160 goto out;
3162 result = proc_pid_instantiate(dentry, task, NULL);
3163 put_task_struct(task);
3164 out:
3165 return result;
3166 }
3168 /*
3169 * Find the first task with tgid >= tgid
3170 *
3171 */
3172 struct tgid_iter {
3173 unsigned int tgid;
3174 struct task_struct *task;
3175 };
3176 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3177 {
3178 struct pid *pid;
3180 if (iter.task)
3181 put_task_struct(iter.task);
3182 rcu_read_lock();
3183 retry:
3184 iter.task = NULL;
3185 pid = find_ge_pid(iter.tgid, ns);
3186 if (pid) {
3187 iter.tgid = pid_nr_ns(pid, ns);
3188 iter.task = pid_task(pid, PIDTYPE_PID);
3189 /* What we to know is if the pid we have find is the
3190 * pid of a thread_group_leader. Testing for task
3191 * being a thread_group_leader is the obvious thing
3192 * todo but there is a window when it fails, due to
3193 * the pid transfer logic in de_thread.
3194 *
3195 * So we perform the straight forward test of seeing
3196 * if the pid we have found is the pid of a thread
3197 * group leader, and don't worry if the task we have
3198 * found doesn't happen to be a thread group leader.
3199 * As we don't care in the case of readdir.
3200 */
3201 if (!iter.task || !has_group_leader_pid(iter.task)) {
3202 iter.tgid += 1;
3203 goto retry;
3204 }
3205 get_task_struct(iter.task);
3206 }
3207 rcu_read_unlock();
3208 return iter;
3209 }
3211 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3213 /* for the /proc/ directory itself, after non-process stuff has been done */
3214 int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3215 {
3216 struct tgid_iter iter;
3217 struct pid_namespace *ns = proc_pid_ns(file_inode(file));
3218 loff_t pos = ctx->pos;
3220 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3221 return 0;
3223 if (pos == TGID_OFFSET - 2) {
3224 struct inode *inode = d_inode(ns->proc_self);
3225 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3226 return 0;
3227 ctx->pos = pos = pos + 1;
3228 }
3229 if (pos == TGID_OFFSET - 1) {
3230 struct inode *inode = d_inode(ns->proc_thread_self);
3231 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3232 return 0;
3233 ctx->pos = pos = pos + 1;
3234 }
3235 iter.tgid = pos - TGID_OFFSET;
3236 iter.task = NULL;
3237 for (iter = next_tgid(ns, iter);
3238 iter.task;
3239 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3240 char name[10 + 1];
3241 unsigned int len;
3243 cond_resched();
3244 if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE))
3245 continue;
3247 len = snprintf(name, sizeof(name), "%u", iter.tgid);
3248 ctx->pos = iter.tgid + TGID_OFFSET;
3249 if (!proc_fill_cache(file, ctx, name, len,
3250 proc_pid_instantiate, iter.task, NULL)) {
3251 put_task_struct(iter.task);
3252 return 0;
3253 }
3254 }
3255 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3256 return 0;
3257 }
3259 /*
3260 * proc_tid_comm_permission is a special permission function exclusively
3261 * used for the node /proc/<pid>/task/<tid>/comm.
3262 * It bypasses generic permission checks in the case where a task of the same
3263 * task group attempts to access the node.
3264 * The rationale behind this is that glibc and bionic access this node for
3265 * cross thread naming (pthread_set/getname_np(!self)). However, if
3266 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3267 * which locks out the cross thread naming implementation.
3268 * This function makes sure that the node is always accessible for members of
3269 * same thread group.
3270 */
3271 static int proc_tid_comm_permission(struct inode *inode, int mask)
3272 {
3273 bool is_same_tgroup;
3274 struct task_struct *task;
3276 task = get_proc_task(inode);
3277 if (!task)
3278 return -ESRCH;
3279 is_same_tgroup = same_thread_group(current, task);
3280 put_task_struct(task);
3282 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3283 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3284 * read or written by the members of the corresponding
3285 * thread group.
3286 */
3287 return 0;
3288 }
3290 return generic_permission(inode, mask);
3291 }
3293 static const struct inode_operations proc_tid_comm_inode_operations = {
3294 .permission = proc_tid_comm_permission,
3295 };
3297 /*
3298 * Tasks
3299 */
3300 static const struct pid_entry tid_base_stuff[] = {
3301 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3302 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3303 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3304 #ifdef CONFIG_NET
3305 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3306 #endif
3307 REG("environ", S_IRUSR, proc_environ_operations),
3308 REG("auxv", S_IRUSR, proc_auxv_operations),
3309 ONE("status", S_IRUGO, proc_pid_status),
3310 ONE("personality", S_IRUSR, proc_pid_personality),
3311 ONE("limits", S_IRUGO, proc_pid_limits),
3312 #ifdef CONFIG_SCHED_DEBUG
3313 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3314 #endif
3315 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3316 &proc_tid_comm_inode_operations,
3317 &proc_pid_set_comm_operations, {}),
3318 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3319 ONE("syscall", S_IRUSR, proc_pid_syscall),
3320 #endif
3321 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3322 ONE("stat", S_IRUGO, proc_tid_stat),
3323 ONE("statm", S_IRUGO, proc_pid_statm),
3324 REG("maps", S_IRUGO, proc_pid_maps_operations),
3325 #ifdef CONFIG_PROC_CHILDREN
3326 REG("children", S_IRUGO, proc_tid_children_operations),
3327 #endif
3328 #ifdef CONFIG_NUMA
3329 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3330 #endif
3331 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3332 LNK("cwd", proc_cwd_link),
3333 LNK("root", proc_root_link),
3334 LNK("exe", proc_exe_link),
3335 REG("mounts", S_IRUGO, proc_mounts_operations),
3336 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3337 #ifdef CONFIG_PROC_PAGE_MONITOR
3338 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3339 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3340 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3341 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3342 #endif
3343 #ifdef CONFIG_SECURITY
3344 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3345 #endif
3346 #ifdef CONFIG_KALLSYMS
3347 ONE("wchan", S_IRUGO, proc_pid_wchan),
3348 #endif
3349 #ifdef CONFIG_STACKTRACE
3350 ONE("stack", S_IRUSR, proc_pid_stack),
3351 #endif
3352 #ifdef CONFIG_SCHED_INFO
3353 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3354 #endif
3355 #ifdef CONFIG_LATENCYTOP
3356 REG("latency", S_IRUGO, proc_lstats_operations),
3357 #endif
3358 #ifdef CONFIG_PROC_PID_CPUSET
3359 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3360 #endif
3361 #ifdef CONFIG_CGROUPS
3362 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3363 #endif
3364 ONE("oom_score", S_IRUGO, proc_oom_score),
3365 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3366 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3367 #ifdef CONFIG_AUDITSYSCALL
3368 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3369 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3370 #endif
3371 #ifdef CONFIG_FAULT_INJECTION
3372 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3373 REG("fail-nth", 0644, proc_fail_nth_operations),
3374 #endif
3375 #ifdef CONFIG_TASK_IO_ACCOUNTING
3376 ONE("io", S_IRUSR, proc_tid_io_accounting),
3377 #endif
3378 #ifdef CONFIG_USER_NS
3379 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3380 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3381 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3382 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3383 #endif
3384 #ifdef CONFIG_LIVEPATCH
3385 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3386 #endif
3387 };
3389 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3390 {
3391 return proc_pident_readdir(file, ctx,
3392 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3393 }
3395 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3396 {
3397 return proc_pident_lookup(dir, dentry,
3398 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3399 }
3401 static const struct file_operations proc_tid_base_operations = {
3402 .read = generic_read_dir,
3403 .iterate_shared = proc_tid_base_readdir,
3404 .llseek = generic_file_llseek,
3405 };
3407 static const struct inode_operations proc_tid_base_inode_operations = {
3408 .lookup = proc_tid_base_lookup,
3409 .getattr = pid_getattr,
3410 .setattr = proc_setattr,
3411 };
3413 static struct dentry *proc_task_instantiate(struct dentry *dentry,
3414 struct task_struct *task, const void *ptr)
3415 {
3416 struct inode *inode;
3417 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3418 if (!inode)
3419 return ERR_PTR(-ENOENT);
3421 inode->i_op = &proc_tid_base_inode_operations;
3422 inode->i_fop = &proc_tid_base_operations;
3423 inode->i_flags |= S_IMMUTABLE;
3425 set_nlink(inode, nlink_tid);
3426 pid_update_inode(task, inode);
3428 d_set_d_op(dentry, &pid_dentry_operations);
3429 return d_splice_alias(inode, dentry);
3430 }
3432 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3433 {
3434 struct task_struct *task;
3435 struct task_struct *leader = get_proc_task(dir);
3436 unsigned tid;
3437 struct pid_namespace *ns;
3438 struct dentry *result = ERR_PTR(-ENOENT);
3440 if (!leader)
3441 goto out_no_task;
3443 tid = name_to_int(&dentry->d_name);
3444 if (tid == ~0U)
3445 goto out;
3447 ns = dentry->d_sb->s_fs_info;
3448 rcu_read_lock();
3449 task = find_task_by_pid_ns(tid, ns);
3450 if (task)
3451 get_task_struct(task);
3452 rcu_read_unlock();
3453 if (!task)
3454 goto out;
3455 if (!same_thread_group(leader, task))
3456 goto out_drop_task;
3458 result = proc_task_instantiate(dentry, task, NULL);
3459 out_drop_task:
3460 put_task_struct(task);
3461 out:
3462 put_task_struct(leader);
3463 out_no_task:
3464 return result;
3465 }
3467 /*
3468 * Find the first tid of a thread group to return to user space.
3469 *
3470 * Usually this is just the thread group leader, but if the users
3471 * buffer was too small or there was a seek into the middle of the
3472 * directory we have more work todo.
3473 *
3474 * In the case of a short read we start with find_task_by_pid.
3475 *
3476 * In the case of a seek we start with the leader and walk nr
3477 * threads past it.
3478 */
3479 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3480 struct pid_namespace *ns)
3481 {
3482 struct task_struct *pos, *task;
3483 unsigned long nr = f_pos;
3485 if (nr != f_pos) /* 32bit overflow? */
3486 return NULL;
3488 rcu_read_lock();
3489 task = pid_task(pid, PIDTYPE_PID);
3490 if (!task)
3491 goto fail;
3493 /* Attempt to start with the tid of a thread */
3494 if (tid && nr) {
3495 pos = find_task_by_pid_ns(tid, ns);
3496 if (pos && same_thread_group(pos, task))
3497 goto found;
3498 }
3500 /* If nr exceeds the number of threads there is nothing todo */
3501 if (nr >= get_nr_threads(task))
3502 goto fail;
3504 /* If we haven't found our starting place yet start
3505 * with the leader and walk nr threads forward.
3506 */
3507 pos = task = task->group_leader;
3508 do {
3509 if (!nr--)
3510 goto found;
3511 } while_each_thread(task, pos);
3512 fail:
3513 pos = NULL;
3514 goto out;
3515 found:
3516 get_task_struct(pos);
3517 out:
3518 rcu_read_unlock();
3519 return pos;
3520 }
3522 /*
3523 * Find the next thread in the thread list.
3524 * Return NULL if there is an error or no next thread.
3525 *
3526 * The reference to the input task_struct is released.
3527 */
3528 static struct task_struct *next_tid(struct task_struct *start)
3529 {
3530 struct task_struct *pos = NULL;
3531 rcu_read_lock();
3532 if (pid_alive(start)) {
3533 pos = next_thread(start);
3534 if (thread_group_leader(pos))
3535 pos = NULL;
3536 else
3537 get_task_struct(pos);
3538 }
3539 rcu_read_unlock();
3540 put_task_struct(start);
3541 return pos;
3542 }
3544 /* for the /proc/TGID/task/ directories */
3545 static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3546 {
3547 struct inode *inode = file_inode(file);
3548 struct task_struct *task;
3549 struct pid_namespace *ns;
3550 int tid;
3552 if (proc_inode_is_dead(inode))
3553 return -ENOENT;
3555 if (!dir_emit_dots(file, ctx))
3556 return 0;
3558 /* f_version caches the tgid value that the last readdir call couldn't
3559 * return. lseek aka telldir automagically resets f_version to 0.
3560 */
3561 ns = proc_pid_ns(inode);
3562 tid = (int)file->f_version;
3563 file->f_version = 0;
3564 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3565 task;
3566 task = next_tid(task), ctx->pos++) {
3567 char name[10 + 1];
3568 unsigned int len;
3569 tid = task_pid_nr_ns(task, ns);
3570 len = snprintf(name, sizeof(name), "%u", tid);
3571 if (!proc_fill_cache(file, ctx, name, len,
3572 proc_task_instantiate, task, NULL)) {
3573 /* returning this tgid failed, save it as the first
3574 * pid for the next readir call */
3575 file->f_version = (u64)tid;
3576 put_task_struct(task);
3577 break;
3578 }
3579 }
3581 return 0;
3582 }
3584 static int proc_task_getattr(const struct path *path, struct kstat *stat,
3585 u32 request_mask, unsigned int query_flags)
3586 {
3587 struct inode *inode = d_inode(path->dentry);
3588 struct task_struct *p = get_proc_task(inode);
3589 generic_fillattr(inode, stat);
3591 if (p) {
3592 stat->nlink += get_nr_threads(p);
3593 put_task_struct(p);
3594 }
3596 return 0;
3597 }
3599 static const struct inode_operations proc_task_inode_operations = {
3600 .lookup = proc_task_lookup,
3601 .getattr = proc_task_getattr,
3602 .setattr = proc_setattr,
3603 .permission = proc_pid_permission,
3604 };
3606 static const struct file_operations proc_task_operations = {
3607 .read = generic_read_dir,
3608 .iterate_shared = proc_task_readdir,
3609 .llseek = generic_file_llseek,
3610 };
3612 void __init set_proc_pid_nlink(void)
3613 {
3614 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3615 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3616 }