Loading...
1/*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
48 */
49
50#include <asm/uaccess.h>
51
52#include <linux/errno.h>
53#include <linux/time.h>
54#include <linux/proc_fs.h>
55#include <linux/stat.h>
56#include <linux/task_io_accounting_ops.h>
57#include <linux/init.h>
58#include <linux/capability.h>
59#include <linux/file.h>
60#include <linux/fdtable.h>
61#include <linux/string.h>
62#include <linux/seq_file.h>
63#include <linux/namei.h>
64#include <linux/mnt_namespace.h>
65#include <linux/mm.h>
66#include <linux/swap.h>
67#include <linux/rcupdate.h>
68#include <linux/kallsyms.h>
69#include <linux/stacktrace.h>
70#include <linux/resource.h>
71#include <linux/module.h>
72#include <linux/mount.h>
73#include <linux/security.h>
74#include <linux/ptrace.h>
75#include <linux/tracehook.h>
76#include <linux/cgroup.h>
77#include <linux/cpuset.h>
78#include <linux/audit.h>
79#include <linux/poll.h>
80#include <linux/nsproxy.h>
81#include <linux/oom.h>
82#include <linux/elf.h>
83#include <linux/pid_namespace.h>
84#include <linux/fs_struct.h>
85#include <linux/slab.h>
86#ifdef CONFIG_HARDWALL
87#include <asm/hardwall.h>
88#endif
89#include "internal.h"
90
91/* NOTE:
92 * Implementing inode permission operations in /proc is almost
93 * certainly an error. Permission checks need to happen during
94 * each system call not at open time. The reason is that most of
95 * what we wish to check for permissions in /proc varies at runtime.
96 *
97 * The classic example of a problem is opening file descriptors
98 * in /proc for a task before it execs a suid executable.
99 */
100
101struct pid_entry {
102 char *name;
103 int len;
104 mode_t mode;
105 const struct inode_operations *iop;
106 const struct file_operations *fop;
107 union proc_op op;
108};
109
110#define NOD(NAME, MODE, IOP, FOP, OP) { \
111 .name = (NAME), \
112 .len = sizeof(NAME) - 1, \
113 .mode = MODE, \
114 .iop = IOP, \
115 .fop = FOP, \
116 .op = OP, \
117}
118
119#define DIR(NAME, MODE, iops, fops) \
120 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
121#define LNK(NAME, get_link) \
122 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
123 &proc_pid_link_inode_operations, NULL, \
124 { .proc_get_link = get_link } )
125#define REG(NAME, MODE, fops) \
126 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
127#define INF(NAME, MODE, read) \
128 NOD(NAME, (S_IFREG|(MODE)), \
129 NULL, &proc_info_file_operations, \
130 { .proc_read = read } )
131#define ONE(NAME, MODE, show) \
132 NOD(NAME, (S_IFREG|(MODE)), \
133 NULL, &proc_single_file_operations, \
134 { .proc_show = show } )
135
136/*
137 * Count the number of hardlinks for the pid_entry table, excluding the .
138 * and .. links.
139 */
140static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
141 unsigned int n)
142{
143 unsigned int i;
144 unsigned int count;
145
146 count = 0;
147 for (i = 0; i < n; ++i) {
148 if (S_ISDIR(entries[i].mode))
149 ++count;
150 }
151
152 return count;
153}
154
155static int get_task_root(struct task_struct *task, struct path *root)
156{
157 int result = -ENOENT;
158
159 task_lock(task);
160 if (task->fs) {
161 get_fs_root(task->fs, root);
162 result = 0;
163 }
164 task_unlock(task);
165 return result;
166}
167
168static int proc_cwd_link(struct inode *inode, struct path *path)
169{
170 struct task_struct *task = get_proc_task(inode);
171 int result = -ENOENT;
172
173 if (task) {
174 task_lock(task);
175 if (task->fs) {
176 get_fs_pwd(task->fs, path);
177 result = 0;
178 }
179 task_unlock(task);
180 put_task_struct(task);
181 }
182 return result;
183}
184
185static int proc_root_link(struct inode *inode, struct path *path)
186{
187 struct task_struct *task = get_proc_task(inode);
188 int result = -ENOENT;
189
190 if (task) {
191 result = get_task_root(task, path);
192 put_task_struct(task);
193 }
194 return result;
195}
196
197static struct mm_struct *__check_mem_permission(struct task_struct *task)
198{
199 struct mm_struct *mm;
200
201 mm = get_task_mm(task);
202 if (!mm)
203 return ERR_PTR(-EINVAL);
204
205 /*
206 * A task can always look at itself, in case it chooses
207 * to use system calls instead of load instructions.
208 */
209 if (task == current)
210 return mm;
211
212 /*
213 * If current is actively ptrace'ing, and would also be
214 * permitted to freshly attach with ptrace now, permit it.
215 */
216 if (task_is_stopped_or_traced(task)) {
217 int match;
218 rcu_read_lock();
219 match = (ptrace_parent(task) == current);
220 rcu_read_unlock();
221 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
222 return mm;
223 }
224
225 /*
226 * No one else is allowed.
227 */
228 mmput(mm);
229 return ERR_PTR(-EPERM);
230}
231
232/*
233 * If current may access user memory in @task return a reference to the
234 * corresponding mm, otherwise ERR_PTR.
235 */
236static struct mm_struct *check_mem_permission(struct task_struct *task)
237{
238 struct mm_struct *mm;
239 int err;
240
241 /*
242 * Avoid racing if task exec's as we might get a new mm but validate
243 * against old credentials.
244 */
245 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
246 if (err)
247 return ERR_PTR(err);
248
249 mm = __check_mem_permission(task);
250 mutex_unlock(&task->signal->cred_guard_mutex);
251
252 return mm;
253}
254
255struct mm_struct *mm_for_maps(struct task_struct *task)
256{
257 struct mm_struct *mm;
258 int err;
259
260 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
261 if (err)
262 return ERR_PTR(err);
263
264 mm = get_task_mm(task);
265 if (mm && mm != current->mm &&
266 !ptrace_may_access(task, PTRACE_MODE_READ)) {
267 mmput(mm);
268 mm = ERR_PTR(-EACCES);
269 }
270 mutex_unlock(&task->signal->cred_guard_mutex);
271
272 return mm;
273}
274
275static int proc_pid_cmdline(struct task_struct *task, char * buffer)
276{
277 int res = 0;
278 unsigned int len;
279 struct mm_struct *mm = get_task_mm(task);
280 if (!mm)
281 goto out;
282 if (!mm->arg_end)
283 goto out_mm; /* Shh! No looking before we're done */
284
285 len = mm->arg_end - mm->arg_start;
286
287 if (len > PAGE_SIZE)
288 len = PAGE_SIZE;
289
290 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
291
292 // If the nul at the end of args has been overwritten, then
293 // assume application is using setproctitle(3).
294 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
295 len = strnlen(buffer, res);
296 if (len < res) {
297 res = len;
298 } else {
299 len = mm->env_end - mm->env_start;
300 if (len > PAGE_SIZE - res)
301 len = PAGE_SIZE - res;
302 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
303 res = strnlen(buffer, res);
304 }
305 }
306out_mm:
307 mmput(mm);
308out:
309 return res;
310}
311
312static int proc_pid_auxv(struct task_struct *task, char *buffer)
313{
314 struct mm_struct *mm = mm_for_maps(task);
315 int res = PTR_ERR(mm);
316 if (mm && !IS_ERR(mm)) {
317 unsigned int nwords = 0;
318 do {
319 nwords += 2;
320 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
321 res = nwords * sizeof(mm->saved_auxv[0]);
322 if (res > PAGE_SIZE)
323 res = PAGE_SIZE;
324 memcpy(buffer, mm->saved_auxv, res);
325 mmput(mm);
326 }
327 return res;
328}
329
330
331#ifdef CONFIG_KALLSYMS
332/*
333 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
334 * Returns the resolved symbol. If that fails, simply return the address.
335 */
336static int proc_pid_wchan(struct task_struct *task, char *buffer)
337{
338 unsigned long wchan;
339 char symname[KSYM_NAME_LEN];
340
341 wchan = get_wchan(task);
342
343 if (lookup_symbol_name(wchan, symname) < 0)
344 if (!ptrace_may_access(task, PTRACE_MODE_READ))
345 return 0;
346 else
347 return sprintf(buffer, "%lu", wchan);
348 else
349 return sprintf(buffer, "%s", symname);
350}
351#endif /* CONFIG_KALLSYMS */
352
353static int lock_trace(struct task_struct *task)
354{
355 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
356 if (err)
357 return err;
358 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
359 mutex_unlock(&task->signal->cred_guard_mutex);
360 return -EPERM;
361 }
362 return 0;
363}
364
365static void unlock_trace(struct task_struct *task)
366{
367 mutex_unlock(&task->signal->cred_guard_mutex);
368}
369
370#ifdef CONFIG_STACKTRACE
371
372#define MAX_STACK_TRACE_DEPTH 64
373
374static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
375 struct pid *pid, struct task_struct *task)
376{
377 struct stack_trace trace;
378 unsigned long *entries;
379 int err;
380 int i;
381
382 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
383 if (!entries)
384 return -ENOMEM;
385
386 trace.nr_entries = 0;
387 trace.max_entries = MAX_STACK_TRACE_DEPTH;
388 trace.entries = entries;
389 trace.skip = 0;
390
391 err = lock_trace(task);
392 if (!err) {
393 save_stack_trace_tsk(task, &trace);
394
395 for (i = 0; i < trace.nr_entries; i++) {
396 seq_printf(m, "[<%pK>] %pS\n",
397 (void *)entries[i], (void *)entries[i]);
398 }
399 unlock_trace(task);
400 }
401 kfree(entries);
402
403 return err;
404}
405#endif
406
407#ifdef CONFIG_SCHEDSTATS
408/*
409 * Provides /proc/PID/schedstat
410 */
411static int proc_pid_schedstat(struct task_struct *task, char *buffer)
412{
413 return sprintf(buffer, "%llu %llu %lu\n",
414 (unsigned long long)task->se.sum_exec_runtime,
415 (unsigned long long)task->sched_info.run_delay,
416 task->sched_info.pcount);
417}
418#endif
419
420#ifdef CONFIG_LATENCYTOP
421static int lstats_show_proc(struct seq_file *m, void *v)
422{
423 int i;
424 struct inode *inode = m->private;
425 struct task_struct *task = get_proc_task(inode);
426
427 if (!task)
428 return -ESRCH;
429 seq_puts(m, "Latency Top version : v0.1\n");
430 for (i = 0; i < 32; i++) {
431 struct latency_record *lr = &task->latency_record[i];
432 if (lr->backtrace[0]) {
433 int q;
434 seq_printf(m, "%i %li %li",
435 lr->count, lr->time, lr->max);
436 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
437 unsigned long bt = lr->backtrace[q];
438 if (!bt)
439 break;
440 if (bt == ULONG_MAX)
441 break;
442 seq_printf(m, " %ps", (void *)bt);
443 }
444 seq_putc(m, '\n');
445 }
446
447 }
448 put_task_struct(task);
449 return 0;
450}
451
452static int lstats_open(struct inode *inode, struct file *file)
453{
454 return single_open(file, lstats_show_proc, inode);
455}
456
457static ssize_t lstats_write(struct file *file, const char __user *buf,
458 size_t count, loff_t *offs)
459{
460 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
461
462 if (!task)
463 return -ESRCH;
464 clear_all_latency_tracing(task);
465 put_task_struct(task);
466
467 return count;
468}
469
470static const struct file_operations proc_lstats_operations = {
471 .open = lstats_open,
472 .read = seq_read,
473 .write = lstats_write,
474 .llseek = seq_lseek,
475 .release = single_release,
476};
477
478#endif
479
480static int proc_oom_score(struct task_struct *task, char *buffer)
481{
482 unsigned long points = 0;
483
484 read_lock(&tasklist_lock);
485 if (pid_alive(task))
486 points = oom_badness(task, NULL, NULL,
487 totalram_pages + total_swap_pages);
488 read_unlock(&tasklist_lock);
489 return sprintf(buffer, "%lu\n", points);
490}
491
492struct limit_names {
493 char *name;
494 char *unit;
495};
496
497static const struct limit_names lnames[RLIM_NLIMITS] = {
498 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
499 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
500 [RLIMIT_DATA] = {"Max data size", "bytes"},
501 [RLIMIT_STACK] = {"Max stack size", "bytes"},
502 [RLIMIT_CORE] = {"Max core file size", "bytes"},
503 [RLIMIT_RSS] = {"Max resident set", "bytes"},
504 [RLIMIT_NPROC] = {"Max processes", "processes"},
505 [RLIMIT_NOFILE] = {"Max open files", "files"},
506 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
507 [RLIMIT_AS] = {"Max address space", "bytes"},
508 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
509 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
510 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
511 [RLIMIT_NICE] = {"Max nice priority", NULL},
512 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
513 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
514};
515
516/* Display limits for a process */
517static int proc_pid_limits(struct task_struct *task, char *buffer)
518{
519 unsigned int i;
520 int count = 0;
521 unsigned long flags;
522 char *bufptr = buffer;
523
524 struct rlimit rlim[RLIM_NLIMITS];
525
526 if (!lock_task_sighand(task, &flags))
527 return 0;
528 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
529 unlock_task_sighand(task, &flags);
530
531 /*
532 * print the file header
533 */
534 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
535 "Limit", "Soft Limit", "Hard Limit", "Units");
536
537 for (i = 0; i < RLIM_NLIMITS; i++) {
538 if (rlim[i].rlim_cur == RLIM_INFINITY)
539 count += sprintf(&bufptr[count], "%-25s %-20s ",
540 lnames[i].name, "unlimited");
541 else
542 count += sprintf(&bufptr[count], "%-25s %-20lu ",
543 lnames[i].name, rlim[i].rlim_cur);
544
545 if (rlim[i].rlim_max == RLIM_INFINITY)
546 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
547 else
548 count += sprintf(&bufptr[count], "%-20lu ",
549 rlim[i].rlim_max);
550
551 if (lnames[i].unit)
552 count += sprintf(&bufptr[count], "%-10s\n",
553 lnames[i].unit);
554 else
555 count += sprintf(&bufptr[count], "\n");
556 }
557
558 return count;
559}
560
561#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
562static int proc_pid_syscall(struct task_struct *task, char *buffer)
563{
564 long nr;
565 unsigned long args[6], sp, pc;
566 int res = lock_trace(task);
567 if (res)
568 return res;
569
570 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
571 res = sprintf(buffer, "running\n");
572 else if (nr < 0)
573 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
574 else
575 res = sprintf(buffer,
576 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
577 nr,
578 args[0], args[1], args[2], args[3], args[4], args[5],
579 sp, pc);
580 unlock_trace(task);
581 return res;
582}
583#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
584
585/************************************************************************/
586/* Here the fs part begins */
587/************************************************************************/
588
589/* permission checks */
590static int proc_fd_access_allowed(struct inode *inode)
591{
592 struct task_struct *task;
593 int allowed = 0;
594 /* Allow access to a task's file descriptors if it is us or we
595 * may use ptrace attach to the process and find out that
596 * information.
597 */
598 task = get_proc_task(inode);
599 if (task) {
600 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
601 put_task_struct(task);
602 }
603 return allowed;
604}
605
606int proc_setattr(struct dentry *dentry, struct iattr *attr)
607{
608 int error;
609 struct inode *inode = dentry->d_inode;
610
611 if (attr->ia_valid & ATTR_MODE)
612 return -EPERM;
613
614 error = inode_change_ok(inode, attr);
615 if (error)
616 return error;
617
618 if ((attr->ia_valid & ATTR_SIZE) &&
619 attr->ia_size != i_size_read(inode)) {
620 error = vmtruncate(inode, attr->ia_size);
621 if (error)
622 return error;
623 }
624
625 setattr_copy(inode, attr);
626 mark_inode_dirty(inode);
627 return 0;
628}
629
630static const struct inode_operations proc_def_inode_operations = {
631 .setattr = proc_setattr,
632};
633
634static int mounts_open_common(struct inode *inode, struct file *file,
635 const struct seq_operations *op)
636{
637 struct task_struct *task = get_proc_task(inode);
638 struct nsproxy *nsp;
639 struct mnt_namespace *ns = NULL;
640 struct path root;
641 struct proc_mounts *p;
642 int ret = -EINVAL;
643
644 if (task) {
645 rcu_read_lock();
646 nsp = task_nsproxy(task);
647 if (nsp) {
648 ns = nsp->mnt_ns;
649 if (ns)
650 get_mnt_ns(ns);
651 }
652 rcu_read_unlock();
653 if (ns && get_task_root(task, &root) == 0)
654 ret = 0;
655 put_task_struct(task);
656 }
657
658 if (!ns)
659 goto err;
660 if (ret)
661 goto err_put_ns;
662
663 ret = -ENOMEM;
664 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
665 if (!p)
666 goto err_put_path;
667
668 file->private_data = &p->m;
669 ret = seq_open(file, op);
670 if (ret)
671 goto err_free;
672
673 p->m.private = p;
674 p->ns = ns;
675 p->root = root;
676 p->m.poll_event = ns->event;
677
678 return 0;
679
680 err_free:
681 kfree(p);
682 err_put_path:
683 path_put(&root);
684 err_put_ns:
685 put_mnt_ns(ns);
686 err:
687 return ret;
688}
689
690static int mounts_release(struct inode *inode, struct file *file)
691{
692 struct proc_mounts *p = file->private_data;
693 path_put(&p->root);
694 put_mnt_ns(p->ns);
695 return seq_release(inode, file);
696}
697
698static unsigned mounts_poll(struct file *file, poll_table *wait)
699{
700 struct proc_mounts *p = file->private_data;
701 unsigned res = POLLIN | POLLRDNORM;
702
703 poll_wait(file, &p->ns->poll, wait);
704 if (mnt_had_events(p))
705 res |= POLLERR | POLLPRI;
706
707 return res;
708}
709
710static int mounts_open(struct inode *inode, struct file *file)
711{
712 return mounts_open_common(inode, file, &mounts_op);
713}
714
715static const struct file_operations proc_mounts_operations = {
716 .open = mounts_open,
717 .read = seq_read,
718 .llseek = seq_lseek,
719 .release = mounts_release,
720 .poll = mounts_poll,
721};
722
723static int mountinfo_open(struct inode *inode, struct file *file)
724{
725 return mounts_open_common(inode, file, &mountinfo_op);
726}
727
728static const struct file_operations proc_mountinfo_operations = {
729 .open = mountinfo_open,
730 .read = seq_read,
731 .llseek = seq_lseek,
732 .release = mounts_release,
733 .poll = mounts_poll,
734};
735
736static int mountstats_open(struct inode *inode, struct file *file)
737{
738 return mounts_open_common(inode, file, &mountstats_op);
739}
740
741static const struct file_operations proc_mountstats_operations = {
742 .open = mountstats_open,
743 .read = seq_read,
744 .llseek = seq_lseek,
745 .release = mounts_release,
746};
747
748#define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
749
750static ssize_t proc_info_read(struct file * file, char __user * buf,
751 size_t count, loff_t *ppos)
752{
753 struct inode * inode = file->f_path.dentry->d_inode;
754 unsigned long page;
755 ssize_t length;
756 struct task_struct *task = get_proc_task(inode);
757
758 length = -ESRCH;
759 if (!task)
760 goto out_no_task;
761
762 if (count > PROC_BLOCK_SIZE)
763 count = PROC_BLOCK_SIZE;
764
765 length = -ENOMEM;
766 if (!(page = __get_free_page(GFP_TEMPORARY)))
767 goto out;
768
769 length = PROC_I(inode)->op.proc_read(task, (char*)page);
770
771 if (length >= 0)
772 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
773 free_page(page);
774out:
775 put_task_struct(task);
776out_no_task:
777 return length;
778}
779
780static const struct file_operations proc_info_file_operations = {
781 .read = proc_info_read,
782 .llseek = generic_file_llseek,
783};
784
785static int proc_single_show(struct seq_file *m, void *v)
786{
787 struct inode *inode = m->private;
788 struct pid_namespace *ns;
789 struct pid *pid;
790 struct task_struct *task;
791 int ret;
792
793 ns = inode->i_sb->s_fs_info;
794 pid = proc_pid(inode);
795 task = get_pid_task(pid, PIDTYPE_PID);
796 if (!task)
797 return -ESRCH;
798
799 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
800
801 put_task_struct(task);
802 return ret;
803}
804
805static int proc_single_open(struct inode *inode, struct file *filp)
806{
807 return single_open(filp, proc_single_show, inode);
808}
809
810static const struct file_operations proc_single_file_operations = {
811 .open = proc_single_open,
812 .read = seq_read,
813 .llseek = seq_lseek,
814 .release = single_release,
815};
816
817static int mem_open(struct inode* inode, struct file* file)
818{
819 file->private_data = (void*)((long)current->self_exec_id);
820 /* OK to pass negative loff_t, we can catch out-of-range */
821 file->f_mode |= FMODE_UNSIGNED_OFFSET;
822 return 0;
823}
824
825static ssize_t mem_read(struct file * file, char __user * buf,
826 size_t count, loff_t *ppos)
827{
828 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
829 char *page;
830 unsigned long src = *ppos;
831 int ret = -ESRCH;
832 struct mm_struct *mm;
833
834 if (!task)
835 goto out_no_task;
836
837 ret = -ENOMEM;
838 page = (char *)__get_free_page(GFP_TEMPORARY);
839 if (!page)
840 goto out;
841
842 mm = check_mem_permission(task);
843 ret = PTR_ERR(mm);
844 if (IS_ERR(mm))
845 goto out_free;
846
847 ret = -EIO;
848
849 if (file->private_data != (void*)((long)current->self_exec_id))
850 goto out_put;
851
852 ret = 0;
853
854 while (count > 0) {
855 int this_len, retval;
856
857 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
858 retval = access_remote_vm(mm, src, page, this_len, 0);
859 if (!retval) {
860 if (!ret)
861 ret = -EIO;
862 break;
863 }
864
865 if (copy_to_user(buf, page, retval)) {
866 ret = -EFAULT;
867 break;
868 }
869
870 ret += retval;
871 src += retval;
872 buf += retval;
873 count -= retval;
874 }
875 *ppos = src;
876
877out_put:
878 mmput(mm);
879out_free:
880 free_page((unsigned long) page);
881out:
882 put_task_struct(task);
883out_no_task:
884 return ret;
885}
886
887static ssize_t mem_write(struct file * file, const char __user *buf,
888 size_t count, loff_t *ppos)
889{
890 int copied;
891 char *page;
892 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
893 unsigned long dst = *ppos;
894 struct mm_struct *mm;
895
896 copied = -ESRCH;
897 if (!task)
898 goto out_no_task;
899
900 copied = -ENOMEM;
901 page = (char *)__get_free_page(GFP_TEMPORARY);
902 if (!page)
903 goto out_task;
904
905 mm = check_mem_permission(task);
906 copied = PTR_ERR(mm);
907 if (IS_ERR(mm))
908 goto out_free;
909
910 copied = -EIO;
911 if (file->private_data != (void *)((long)current->self_exec_id))
912 goto out_mm;
913
914 copied = 0;
915 while (count > 0) {
916 int this_len, retval;
917
918 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
919 if (copy_from_user(page, buf, this_len)) {
920 copied = -EFAULT;
921 break;
922 }
923 retval = access_remote_vm(mm, dst, page, this_len, 1);
924 if (!retval) {
925 if (!copied)
926 copied = -EIO;
927 break;
928 }
929 copied += retval;
930 buf += retval;
931 dst += retval;
932 count -= retval;
933 }
934 *ppos = dst;
935
936out_mm:
937 mmput(mm);
938out_free:
939 free_page((unsigned long) page);
940out_task:
941 put_task_struct(task);
942out_no_task:
943 return copied;
944}
945
946loff_t mem_lseek(struct file *file, loff_t offset, int orig)
947{
948 switch (orig) {
949 case 0:
950 file->f_pos = offset;
951 break;
952 case 1:
953 file->f_pos += offset;
954 break;
955 default:
956 return -EINVAL;
957 }
958 force_successful_syscall_return();
959 return file->f_pos;
960}
961
962static const struct file_operations proc_mem_operations = {
963 .llseek = mem_lseek,
964 .read = mem_read,
965 .write = mem_write,
966 .open = mem_open,
967};
968
969static ssize_t environ_read(struct file *file, char __user *buf,
970 size_t count, loff_t *ppos)
971{
972 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
973 char *page;
974 unsigned long src = *ppos;
975 int ret = -ESRCH;
976 struct mm_struct *mm;
977
978 if (!task)
979 goto out_no_task;
980
981 ret = -ENOMEM;
982 page = (char *)__get_free_page(GFP_TEMPORARY);
983 if (!page)
984 goto out;
985
986
987 mm = mm_for_maps(task);
988 ret = PTR_ERR(mm);
989 if (!mm || IS_ERR(mm))
990 goto out_free;
991
992 ret = 0;
993 while (count > 0) {
994 int this_len, retval, max_len;
995
996 this_len = mm->env_end - (mm->env_start + src);
997
998 if (this_len <= 0)
999 break;
1000
1001 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
1002 this_len = (this_len > max_len) ? max_len : this_len;
1003
1004 retval = access_process_vm(task, (mm->env_start + src),
1005 page, this_len, 0);
1006
1007 if (retval <= 0) {
1008 ret = retval;
1009 break;
1010 }
1011
1012 if (copy_to_user(buf, page, retval)) {
1013 ret = -EFAULT;
1014 break;
1015 }
1016
1017 ret += retval;
1018 src += retval;
1019 buf += retval;
1020 count -= retval;
1021 }
1022 *ppos = src;
1023
1024 mmput(mm);
1025out_free:
1026 free_page((unsigned long) page);
1027out:
1028 put_task_struct(task);
1029out_no_task:
1030 return ret;
1031}
1032
1033static const struct file_operations proc_environ_operations = {
1034 .read = environ_read,
1035 .llseek = generic_file_llseek,
1036};
1037
1038static ssize_t oom_adjust_read(struct file *file, char __user *buf,
1039 size_t count, loff_t *ppos)
1040{
1041 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1042 char buffer[PROC_NUMBUF];
1043 size_t len;
1044 int oom_adjust = OOM_DISABLE;
1045 unsigned long flags;
1046
1047 if (!task)
1048 return -ESRCH;
1049
1050 if (lock_task_sighand(task, &flags)) {
1051 oom_adjust = task->signal->oom_adj;
1052 unlock_task_sighand(task, &flags);
1053 }
1054
1055 put_task_struct(task);
1056
1057 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
1058
1059 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1060}
1061
1062static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
1063 size_t count, loff_t *ppos)
1064{
1065 struct task_struct *task;
1066 char buffer[PROC_NUMBUF];
1067 int oom_adjust;
1068 unsigned long flags;
1069 int err;
1070
1071 memset(buffer, 0, sizeof(buffer));
1072 if (count > sizeof(buffer) - 1)
1073 count = sizeof(buffer) - 1;
1074 if (copy_from_user(buffer, buf, count)) {
1075 err = -EFAULT;
1076 goto out;
1077 }
1078
1079 err = kstrtoint(strstrip(buffer), 0, &oom_adjust);
1080 if (err)
1081 goto out;
1082 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
1083 oom_adjust != OOM_DISABLE) {
1084 err = -EINVAL;
1085 goto out;
1086 }
1087
1088 task = get_proc_task(file->f_path.dentry->d_inode);
1089 if (!task) {
1090 err = -ESRCH;
1091 goto out;
1092 }
1093
1094 task_lock(task);
1095 if (!task->mm) {
1096 err = -EINVAL;
1097 goto err_task_lock;
1098 }
1099
1100 if (!lock_task_sighand(task, &flags)) {
1101 err = -ESRCH;
1102 goto err_task_lock;
1103 }
1104
1105 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
1106 err = -EACCES;
1107 goto err_sighand;
1108 }
1109
1110 if (oom_adjust != task->signal->oom_adj) {
1111 if (oom_adjust == OOM_DISABLE)
1112 atomic_inc(&task->mm->oom_disable_count);
1113 if (task->signal->oom_adj == OOM_DISABLE)
1114 atomic_dec(&task->mm->oom_disable_count);
1115 }
1116
1117 /*
1118 * Warn that /proc/pid/oom_adj is deprecated, see
1119 * Documentation/feature-removal-schedule.txt.
1120 */
1121 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1122 current->comm, task_pid_nr(current), task_pid_nr(task),
1123 task_pid_nr(task));
1124 task->signal->oom_adj = oom_adjust;
1125 /*
1126 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1127 * value is always attainable.
1128 */
1129 if (task->signal->oom_adj == OOM_ADJUST_MAX)
1130 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
1131 else
1132 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
1133 -OOM_DISABLE;
1134err_sighand:
1135 unlock_task_sighand(task, &flags);
1136err_task_lock:
1137 task_unlock(task);
1138 put_task_struct(task);
1139out:
1140 return err < 0 ? err : count;
1141}
1142
1143static const struct file_operations proc_oom_adjust_operations = {
1144 .read = oom_adjust_read,
1145 .write = oom_adjust_write,
1146 .llseek = generic_file_llseek,
1147};
1148
1149static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1150 size_t count, loff_t *ppos)
1151{
1152 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1153 char buffer[PROC_NUMBUF];
1154 int oom_score_adj = OOM_SCORE_ADJ_MIN;
1155 unsigned long flags;
1156 size_t len;
1157
1158 if (!task)
1159 return -ESRCH;
1160 if (lock_task_sighand(task, &flags)) {
1161 oom_score_adj = task->signal->oom_score_adj;
1162 unlock_task_sighand(task, &flags);
1163 }
1164 put_task_struct(task);
1165 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
1166 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1167}
1168
1169static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1170 size_t count, loff_t *ppos)
1171{
1172 struct task_struct *task;
1173 char buffer[PROC_NUMBUF];
1174 unsigned long flags;
1175 int oom_score_adj;
1176 int err;
1177
1178 memset(buffer, 0, sizeof(buffer));
1179 if (count > sizeof(buffer) - 1)
1180 count = sizeof(buffer) - 1;
1181 if (copy_from_user(buffer, buf, count)) {
1182 err = -EFAULT;
1183 goto out;
1184 }
1185
1186 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1187 if (err)
1188 goto out;
1189 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1190 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1191 err = -EINVAL;
1192 goto out;
1193 }
1194
1195 task = get_proc_task(file->f_path.dentry->d_inode);
1196 if (!task) {
1197 err = -ESRCH;
1198 goto out;
1199 }
1200
1201 task_lock(task);
1202 if (!task->mm) {
1203 err = -EINVAL;
1204 goto err_task_lock;
1205 }
1206
1207 if (!lock_task_sighand(task, &flags)) {
1208 err = -ESRCH;
1209 goto err_task_lock;
1210 }
1211
1212 if (oom_score_adj < task->signal->oom_score_adj_min &&
1213 !capable(CAP_SYS_RESOURCE)) {
1214 err = -EACCES;
1215 goto err_sighand;
1216 }
1217
1218 if (oom_score_adj != task->signal->oom_score_adj) {
1219 if (oom_score_adj == OOM_SCORE_ADJ_MIN)
1220 atomic_inc(&task->mm->oom_disable_count);
1221 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1222 atomic_dec(&task->mm->oom_disable_count);
1223 }
1224 task->signal->oom_score_adj = oom_score_adj;
1225 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1226 task->signal->oom_score_adj_min = oom_score_adj;
1227 /*
1228 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1229 * always attainable.
1230 */
1231 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1232 task->signal->oom_adj = OOM_DISABLE;
1233 else
1234 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1235 OOM_SCORE_ADJ_MAX;
1236err_sighand:
1237 unlock_task_sighand(task, &flags);
1238err_task_lock:
1239 task_unlock(task);
1240 put_task_struct(task);
1241out:
1242 return err < 0 ? err : count;
1243}
1244
1245static const struct file_operations proc_oom_score_adj_operations = {
1246 .read = oom_score_adj_read,
1247 .write = oom_score_adj_write,
1248 .llseek = default_llseek,
1249};
1250
1251#ifdef CONFIG_AUDITSYSCALL
1252#define TMPBUFLEN 21
1253static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1254 size_t count, loff_t *ppos)
1255{
1256 struct inode * inode = file->f_path.dentry->d_inode;
1257 struct task_struct *task = get_proc_task(inode);
1258 ssize_t length;
1259 char tmpbuf[TMPBUFLEN];
1260
1261 if (!task)
1262 return -ESRCH;
1263 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1264 audit_get_loginuid(task));
1265 put_task_struct(task);
1266 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1267}
1268
1269static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1270 size_t count, loff_t *ppos)
1271{
1272 struct inode * inode = file->f_path.dentry->d_inode;
1273 char *page, *tmp;
1274 ssize_t length;
1275 uid_t loginuid;
1276
1277 if (!capable(CAP_AUDIT_CONTROL))
1278 return -EPERM;
1279
1280 rcu_read_lock();
1281 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1282 rcu_read_unlock();
1283 return -EPERM;
1284 }
1285 rcu_read_unlock();
1286
1287 if (count >= PAGE_SIZE)
1288 count = PAGE_SIZE - 1;
1289
1290 if (*ppos != 0) {
1291 /* No partial writes. */
1292 return -EINVAL;
1293 }
1294 page = (char*)__get_free_page(GFP_TEMPORARY);
1295 if (!page)
1296 return -ENOMEM;
1297 length = -EFAULT;
1298 if (copy_from_user(page, buf, count))
1299 goto out_free_page;
1300
1301 page[count] = '\0';
1302 loginuid = simple_strtoul(page, &tmp, 10);
1303 if (tmp == page) {
1304 length = -EINVAL;
1305 goto out_free_page;
1306
1307 }
1308 length = audit_set_loginuid(current, loginuid);
1309 if (likely(length == 0))
1310 length = count;
1311
1312out_free_page:
1313 free_page((unsigned long) page);
1314 return length;
1315}
1316
1317static const struct file_operations proc_loginuid_operations = {
1318 .read = proc_loginuid_read,
1319 .write = proc_loginuid_write,
1320 .llseek = generic_file_llseek,
1321};
1322
1323static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1324 size_t count, loff_t *ppos)
1325{
1326 struct inode * inode = file->f_path.dentry->d_inode;
1327 struct task_struct *task = get_proc_task(inode);
1328 ssize_t length;
1329 char tmpbuf[TMPBUFLEN];
1330
1331 if (!task)
1332 return -ESRCH;
1333 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1334 audit_get_sessionid(task));
1335 put_task_struct(task);
1336 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1337}
1338
1339static const struct file_operations proc_sessionid_operations = {
1340 .read = proc_sessionid_read,
1341 .llseek = generic_file_llseek,
1342};
1343#endif
1344
1345#ifdef CONFIG_FAULT_INJECTION
1346static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1347 size_t count, loff_t *ppos)
1348{
1349 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1350 char buffer[PROC_NUMBUF];
1351 size_t len;
1352 int make_it_fail;
1353
1354 if (!task)
1355 return -ESRCH;
1356 make_it_fail = task->make_it_fail;
1357 put_task_struct(task);
1358
1359 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1360
1361 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1362}
1363
1364static ssize_t proc_fault_inject_write(struct file * file,
1365 const char __user * buf, size_t count, loff_t *ppos)
1366{
1367 struct task_struct *task;
1368 char buffer[PROC_NUMBUF], *end;
1369 int make_it_fail;
1370
1371 if (!capable(CAP_SYS_RESOURCE))
1372 return -EPERM;
1373 memset(buffer, 0, sizeof(buffer));
1374 if (count > sizeof(buffer) - 1)
1375 count = sizeof(buffer) - 1;
1376 if (copy_from_user(buffer, buf, count))
1377 return -EFAULT;
1378 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1379 if (*end)
1380 return -EINVAL;
1381 task = get_proc_task(file->f_dentry->d_inode);
1382 if (!task)
1383 return -ESRCH;
1384 task->make_it_fail = make_it_fail;
1385 put_task_struct(task);
1386
1387 return count;
1388}
1389
1390static const struct file_operations proc_fault_inject_operations = {
1391 .read = proc_fault_inject_read,
1392 .write = proc_fault_inject_write,
1393 .llseek = generic_file_llseek,
1394};
1395#endif
1396
1397
1398#ifdef CONFIG_SCHED_DEBUG
1399/*
1400 * Print out various scheduling related per-task fields:
1401 */
1402static int sched_show(struct seq_file *m, void *v)
1403{
1404 struct inode *inode = m->private;
1405 struct task_struct *p;
1406
1407 p = get_proc_task(inode);
1408 if (!p)
1409 return -ESRCH;
1410 proc_sched_show_task(p, m);
1411
1412 put_task_struct(p);
1413
1414 return 0;
1415}
1416
1417static ssize_t
1418sched_write(struct file *file, const char __user *buf,
1419 size_t count, loff_t *offset)
1420{
1421 struct inode *inode = file->f_path.dentry->d_inode;
1422 struct task_struct *p;
1423
1424 p = get_proc_task(inode);
1425 if (!p)
1426 return -ESRCH;
1427 proc_sched_set_task(p);
1428
1429 put_task_struct(p);
1430
1431 return count;
1432}
1433
1434static int sched_open(struct inode *inode, struct file *filp)
1435{
1436 return single_open(filp, sched_show, inode);
1437}
1438
1439static const struct file_operations proc_pid_sched_operations = {
1440 .open = sched_open,
1441 .read = seq_read,
1442 .write = sched_write,
1443 .llseek = seq_lseek,
1444 .release = single_release,
1445};
1446
1447#endif
1448
1449#ifdef CONFIG_SCHED_AUTOGROUP
1450/*
1451 * Print out autogroup related information:
1452 */
1453static int sched_autogroup_show(struct seq_file *m, void *v)
1454{
1455 struct inode *inode = m->private;
1456 struct task_struct *p;
1457
1458 p = get_proc_task(inode);
1459 if (!p)
1460 return -ESRCH;
1461 proc_sched_autogroup_show_task(p, m);
1462
1463 put_task_struct(p);
1464
1465 return 0;
1466}
1467
1468static ssize_t
1469sched_autogroup_write(struct file *file, const char __user *buf,
1470 size_t count, loff_t *offset)
1471{
1472 struct inode *inode = file->f_path.dentry->d_inode;
1473 struct task_struct *p;
1474 char buffer[PROC_NUMBUF];
1475 int nice;
1476 int err;
1477
1478 memset(buffer, 0, sizeof(buffer));
1479 if (count > sizeof(buffer) - 1)
1480 count = sizeof(buffer) - 1;
1481 if (copy_from_user(buffer, buf, count))
1482 return -EFAULT;
1483
1484 err = kstrtoint(strstrip(buffer), 0, &nice);
1485 if (err < 0)
1486 return err;
1487
1488 p = get_proc_task(inode);
1489 if (!p)
1490 return -ESRCH;
1491
1492 err = nice;
1493 err = proc_sched_autogroup_set_nice(p, &err);
1494 if (err)
1495 count = err;
1496
1497 put_task_struct(p);
1498
1499 return count;
1500}
1501
1502static int sched_autogroup_open(struct inode *inode, struct file *filp)
1503{
1504 int ret;
1505
1506 ret = single_open(filp, sched_autogroup_show, NULL);
1507 if (!ret) {
1508 struct seq_file *m = filp->private_data;
1509
1510 m->private = inode;
1511 }
1512 return ret;
1513}
1514
1515static const struct file_operations proc_pid_sched_autogroup_operations = {
1516 .open = sched_autogroup_open,
1517 .read = seq_read,
1518 .write = sched_autogroup_write,
1519 .llseek = seq_lseek,
1520 .release = single_release,
1521};
1522
1523#endif /* CONFIG_SCHED_AUTOGROUP */
1524
1525static ssize_t comm_write(struct file *file, const char __user *buf,
1526 size_t count, loff_t *offset)
1527{
1528 struct inode *inode = file->f_path.dentry->d_inode;
1529 struct task_struct *p;
1530 char buffer[TASK_COMM_LEN];
1531
1532 memset(buffer, 0, sizeof(buffer));
1533 if (count > sizeof(buffer) - 1)
1534 count = sizeof(buffer) - 1;
1535 if (copy_from_user(buffer, buf, count))
1536 return -EFAULT;
1537
1538 p = get_proc_task(inode);
1539 if (!p)
1540 return -ESRCH;
1541
1542 if (same_thread_group(current, p))
1543 set_task_comm(p, buffer);
1544 else
1545 count = -EINVAL;
1546
1547 put_task_struct(p);
1548
1549 return count;
1550}
1551
1552static int comm_show(struct seq_file *m, void *v)
1553{
1554 struct inode *inode = m->private;
1555 struct task_struct *p;
1556
1557 p = get_proc_task(inode);
1558 if (!p)
1559 return -ESRCH;
1560
1561 task_lock(p);
1562 seq_printf(m, "%s\n", p->comm);
1563 task_unlock(p);
1564
1565 put_task_struct(p);
1566
1567 return 0;
1568}
1569
1570static int comm_open(struct inode *inode, struct file *filp)
1571{
1572 return single_open(filp, comm_show, inode);
1573}
1574
1575static const struct file_operations proc_pid_set_comm_operations = {
1576 .open = comm_open,
1577 .read = seq_read,
1578 .write = comm_write,
1579 .llseek = seq_lseek,
1580 .release = single_release,
1581};
1582
1583static int proc_exe_link(struct inode *inode, struct path *exe_path)
1584{
1585 struct task_struct *task;
1586 struct mm_struct *mm;
1587 struct file *exe_file;
1588
1589 task = get_proc_task(inode);
1590 if (!task)
1591 return -ENOENT;
1592 mm = get_task_mm(task);
1593 put_task_struct(task);
1594 if (!mm)
1595 return -ENOENT;
1596 exe_file = get_mm_exe_file(mm);
1597 mmput(mm);
1598 if (exe_file) {
1599 *exe_path = exe_file->f_path;
1600 path_get(&exe_file->f_path);
1601 fput(exe_file);
1602 return 0;
1603 } else
1604 return -ENOENT;
1605}
1606
1607static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1608{
1609 struct inode *inode = dentry->d_inode;
1610 int error = -EACCES;
1611
1612 /* We don't need a base pointer in the /proc filesystem */
1613 path_put(&nd->path);
1614
1615 /* Are we allowed to snoop on the tasks file descriptors? */
1616 if (!proc_fd_access_allowed(inode))
1617 goto out;
1618
1619 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
1620out:
1621 return ERR_PTR(error);
1622}
1623
1624static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1625{
1626 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1627 char *pathname;
1628 int len;
1629
1630 if (!tmp)
1631 return -ENOMEM;
1632
1633 pathname = d_path(path, tmp, PAGE_SIZE);
1634 len = PTR_ERR(pathname);
1635 if (IS_ERR(pathname))
1636 goto out;
1637 len = tmp + PAGE_SIZE - 1 - pathname;
1638
1639 if (len > buflen)
1640 len = buflen;
1641 if (copy_to_user(buffer, pathname, len))
1642 len = -EFAULT;
1643 out:
1644 free_page((unsigned long)tmp);
1645 return len;
1646}
1647
1648static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1649{
1650 int error = -EACCES;
1651 struct inode *inode = dentry->d_inode;
1652 struct path path;
1653
1654 /* Are we allowed to snoop on the tasks file descriptors? */
1655 if (!proc_fd_access_allowed(inode))
1656 goto out;
1657
1658 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1659 if (error)
1660 goto out;
1661
1662 error = do_proc_readlink(&path, buffer, buflen);
1663 path_put(&path);
1664out:
1665 return error;
1666}
1667
1668static const struct inode_operations proc_pid_link_inode_operations = {
1669 .readlink = proc_pid_readlink,
1670 .follow_link = proc_pid_follow_link,
1671 .setattr = proc_setattr,
1672};
1673
1674
1675/* building an inode */
1676
1677static int task_dumpable(struct task_struct *task)
1678{
1679 int dumpable = 0;
1680 struct mm_struct *mm;
1681
1682 task_lock(task);
1683 mm = task->mm;
1684 if (mm)
1685 dumpable = get_dumpable(mm);
1686 task_unlock(task);
1687 if(dumpable == 1)
1688 return 1;
1689 return 0;
1690}
1691
1692struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1693{
1694 struct inode * inode;
1695 struct proc_inode *ei;
1696 const struct cred *cred;
1697
1698 /* We need a new inode */
1699
1700 inode = new_inode(sb);
1701 if (!inode)
1702 goto out;
1703
1704 /* Common stuff */
1705 ei = PROC_I(inode);
1706 inode->i_ino = get_next_ino();
1707 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1708 inode->i_op = &proc_def_inode_operations;
1709
1710 /*
1711 * grab the reference to task.
1712 */
1713 ei->pid = get_task_pid(task, PIDTYPE_PID);
1714 if (!ei->pid)
1715 goto out_unlock;
1716
1717 if (task_dumpable(task)) {
1718 rcu_read_lock();
1719 cred = __task_cred(task);
1720 inode->i_uid = cred->euid;
1721 inode->i_gid = cred->egid;
1722 rcu_read_unlock();
1723 }
1724 security_task_to_inode(task, inode);
1725
1726out:
1727 return inode;
1728
1729out_unlock:
1730 iput(inode);
1731 return NULL;
1732}
1733
1734int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1735{
1736 struct inode *inode = dentry->d_inode;
1737 struct task_struct *task;
1738 const struct cred *cred;
1739
1740 generic_fillattr(inode, stat);
1741
1742 rcu_read_lock();
1743 stat->uid = 0;
1744 stat->gid = 0;
1745 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1746 if (task) {
1747 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1748 task_dumpable(task)) {
1749 cred = __task_cred(task);
1750 stat->uid = cred->euid;
1751 stat->gid = cred->egid;
1752 }
1753 }
1754 rcu_read_unlock();
1755 return 0;
1756}
1757
1758/* dentry stuff */
1759
1760/*
1761 * Exceptional case: normally we are not allowed to unhash a busy
1762 * directory. In this case, however, we can do it - no aliasing problems
1763 * due to the way we treat inodes.
1764 *
1765 * Rewrite the inode's ownerships here because the owning task may have
1766 * performed a setuid(), etc.
1767 *
1768 * Before the /proc/pid/status file was created the only way to read
1769 * the effective uid of a /process was to stat /proc/pid. Reading
1770 * /proc/pid/status is slow enough that procps and other packages
1771 * kept stating /proc/pid. To keep the rules in /proc simple I have
1772 * made this apply to all per process world readable and executable
1773 * directories.
1774 */
1775int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1776{
1777 struct inode *inode;
1778 struct task_struct *task;
1779 const struct cred *cred;
1780
1781 if (nd && nd->flags & LOOKUP_RCU)
1782 return -ECHILD;
1783
1784 inode = dentry->d_inode;
1785 task = get_proc_task(inode);
1786
1787 if (task) {
1788 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1789 task_dumpable(task)) {
1790 rcu_read_lock();
1791 cred = __task_cred(task);
1792 inode->i_uid = cred->euid;
1793 inode->i_gid = cred->egid;
1794 rcu_read_unlock();
1795 } else {
1796 inode->i_uid = 0;
1797 inode->i_gid = 0;
1798 }
1799 inode->i_mode &= ~(S_ISUID | S_ISGID);
1800 security_task_to_inode(task, inode);
1801 put_task_struct(task);
1802 return 1;
1803 }
1804 d_drop(dentry);
1805 return 0;
1806}
1807
1808static int pid_delete_dentry(const struct dentry * dentry)
1809{
1810 /* Is the task we represent dead?
1811 * If so, then don't put the dentry on the lru list,
1812 * kill it immediately.
1813 */
1814 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1815}
1816
1817const struct dentry_operations pid_dentry_operations =
1818{
1819 .d_revalidate = pid_revalidate,
1820 .d_delete = pid_delete_dentry,
1821};
1822
1823/* Lookups */
1824
1825/*
1826 * Fill a directory entry.
1827 *
1828 * If possible create the dcache entry and derive our inode number and
1829 * file type from dcache entry.
1830 *
1831 * Since all of the proc inode numbers are dynamically generated, the inode
1832 * numbers do not exist until the inode is cache. This means creating the
1833 * the dcache entry in readdir is necessary to keep the inode numbers
1834 * reported by readdir in sync with the inode numbers reported
1835 * by stat.
1836 */
1837int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1838 const char *name, int len,
1839 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1840{
1841 struct dentry *child, *dir = filp->f_path.dentry;
1842 struct inode *inode;
1843 struct qstr qname;
1844 ino_t ino = 0;
1845 unsigned type = DT_UNKNOWN;
1846
1847 qname.name = name;
1848 qname.len = len;
1849 qname.hash = full_name_hash(name, len);
1850
1851 child = d_lookup(dir, &qname);
1852 if (!child) {
1853 struct dentry *new;
1854 new = d_alloc(dir, &qname);
1855 if (new) {
1856 child = instantiate(dir->d_inode, new, task, ptr);
1857 if (child)
1858 dput(new);
1859 else
1860 child = new;
1861 }
1862 }
1863 if (!child || IS_ERR(child) || !child->d_inode)
1864 goto end_instantiate;
1865 inode = child->d_inode;
1866 if (inode) {
1867 ino = inode->i_ino;
1868 type = inode->i_mode >> 12;
1869 }
1870 dput(child);
1871end_instantiate:
1872 if (!ino)
1873 ino = find_inode_number(dir, &qname);
1874 if (!ino)
1875 ino = 1;
1876 return filldir(dirent, name, len, filp->f_pos, ino, type);
1877}
1878
1879static unsigned name_to_int(struct dentry *dentry)
1880{
1881 const char *name = dentry->d_name.name;
1882 int len = dentry->d_name.len;
1883 unsigned n = 0;
1884
1885 if (len > 1 && *name == '0')
1886 goto out;
1887 while (len-- > 0) {
1888 unsigned c = *name++ - '0';
1889 if (c > 9)
1890 goto out;
1891 if (n >= (~0U-9)/10)
1892 goto out;
1893 n *= 10;
1894 n += c;
1895 }
1896 return n;
1897out:
1898 return ~0U;
1899}
1900
1901#define PROC_FDINFO_MAX 64
1902
1903static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1904{
1905 struct task_struct *task = get_proc_task(inode);
1906 struct files_struct *files = NULL;
1907 struct file *file;
1908 int fd = proc_fd(inode);
1909
1910 if (task) {
1911 files = get_files_struct(task);
1912 put_task_struct(task);
1913 }
1914 if (files) {
1915 /*
1916 * We are not taking a ref to the file structure, so we must
1917 * hold ->file_lock.
1918 */
1919 spin_lock(&files->file_lock);
1920 file = fcheck_files(files, fd);
1921 if (file) {
1922 unsigned int f_flags;
1923 struct fdtable *fdt;
1924
1925 fdt = files_fdtable(files);
1926 f_flags = file->f_flags & ~O_CLOEXEC;
1927 if (FD_ISSET(fd, fdt->close_on_exec))
1928 f_flags |= O_CLOEXEC;
1929
1930 if (path) {
1931 *path = file->f_path;
1932 path_get(&file->f_path);
1933 }
1934 if (info)
1935 snprintf(info, PROC_FDINFO_MAX,
1936 "pos:\t%lli\n"
1937 "flags:\t0%o\n",
1938 (long long) file->f_pos,
1939 f_flags);
1940 spin_unlock(&files->file_lock);
1941 put_files_struct(files);
1942 return 0;
1943 }
1944 spin_unlock(&files->file_lock);
1945 put_files_struct(files);
1946 }
1947 return -ENOENT;
1948}
1949
1950static int proc_fd_link(struct inode *inode, struct path *path)
1951{
1952 return proc_fd_info(inode, path, NULL);
1953}
1954
1955static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1956{
1957 struct inode *inode;
1958 struct task_struct *task;
1959 int fd;
1960 struct files_struct *files;
1961 const struct cred *cred;
1962
1963 if (nd && nd->flags & LOOKUP_RCU)
1964 return -ECHILD;
1965
1966 inode = dentry->d_inode;
1967 task = get_proc_task(inode);
1968 fd = proc_fd(inode);
1969
1970 if (task) {
1971 files = get_files_struct(task);
1972 if (files) {
1973 rcu_read_lock();
1974 if (fcheck_files(files, fd)) {
1975 rcu_read_unlock();
1976 put_files_struct(files);
1977 if (task_dumpable(task)) {
1978 rcu_read_lock();
1979 cred = __task_cred(task);
1980 inode->i_uid = cred->euid;
1981 inode->i_gid = cred->egid;
1982 rcu_read_unlock();
1983 } else {
1984 inode->i_uid = 0;
1985 inode->i_gid = 0;
1986 }
1987 inode->i_mode &= ~(S_ISUID | S_ISGID);
1988 security_task_to_inode(task, inode);
1989 put_task_struct(task);
1990 return 1;
1991 }
1992 rcu_read_unlock();
1993 put_files_struct(files);
1994 }
1995 put_task_struct(task);
1996 }
1997 d_drop(dentry);
1998 return 0;
1999}
2000
2001static const struct dentry_operations tid_fd_dentry_operations =
2002{
2003 .d_revalidate = tid_fd_revalidate,
2004 .d_delete = pid_delete_dentry,
2005};
2006
2007static struct dentry *proc_fd_instantiate(struct inode *dir,
2008 struct dentry *dentry, struct task_struct *task, const void *ptr)
2009{
2010 unsigned fd = *(const unsigned *)ptr;
2011 struct file *file;
2012 struct files_struct *files;
2013 struct inode *inode;
2014 struct proc_inode *ei;
2015 struct dentry *error = ERR_PTR(-ENOENT);
2016
2017 inode = proc_pid_make_inode(dir->i_sb, task);
2018 if (!inode)
2019 goto out;
2020 ei = PROC_I(inode);
2021 ei->fd = fd;
2022 files = get_files_struct(task);
2023 if (!files)
2024 goto out_iput;
2025 inode->i_mode = S_IFLNK;
2026
2027 /*
2028 * We are not taking a ref to the file structure, so we must
2029 * hold ->file_lock.
2030 */
2031 spin_lock(&files->file_lock);
2032 file = fcheck_files(files, fd);
2033 if (!file)
2034 goto out_unlock;
2035 if (file->f_mode & FMODE_READ)
2036 inode->i_mode |= S_IRUSR | S_IXUSR;
2037 if (file->f_mode & FMODE_WRITE)
2038 inode->i_mode |= S_IWUSR | S_IXUSR;
2039 spin_unlock(&files->file_lock);
2040 put_files_struct(files);
2041
2042 inode->i_op = &proc_pid_link_inode_operations;
2043 inode->i_size = 64;
2044 ei->op.proc_get_link = proc_fd_link;
2045 d_set_d_op(dentry, &tid_fd_dentry_operations);
2046 d_add(dentry, inode);
2047 /* Close the race of the process dying before we return the dentry */
2048 if (tid_fd_revalidate(dentry, NULL))
2049 error = NULL;
2050
2051 out:
2052 return error;
2053out_unlock:
2054 spin_unlock(&files->file_lock);
2055 put_files_struct(files);
2056out_iput:
2057 iput(inode);
2058 goto out;
2059}
2060
2061static struct dentry *proc_lookupfd_common(struct inode *dir,
2062 struct dentry *dentry,
2063 instantiate_t instantiate)
2064{
2065 struct task_struct *task = get_proc_task(dir);
2066 unsigned fd = name_to_int(dentry);
2067 struct dentry *result = ERR_PTR(-ENOENT);
2068
2069 if (!task)
2070 goto out_no_task;
2071 if (fd == ~0U)
2072 goto out;
2073
2074 result = instantiate(dir, dentry, task, &fd);
2075out:
2076 put_task_struct(task);
2077out_no_task:
2078 return result;
2079}
2080
2081static int proc_readfd_common(struct file * filp, void * dirent,
2082 filldir_t filldir, instantiate_t instantiate)
2083{
2084 struct dentry *dentry = filp->f_path.dentry;
2085 struct inode *inode = dentry->d_inode;
2086 struct task_struct *p = get_proc_task(inode);
2087 unsigned int fd, ino;
2088 int retval;
2089 struct files_struct * files;
2090
2091 retval = -ENOENT;
2092 if (!p)
2093 goto out_no_task;
2094 retval = 0;
2095
2096 fd = filp->f_pos;
2097 switch (fd) {
2098 case 0:
2099 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
2100 goto out;
2101 filp->f_pos++;
2102 case 1:
2103 ino = parent_ino(dentry);
2104 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
2105 goto out;
2106 filp->f_pos++;
2107 default:
2108 files = get_files_struct(p);
2109 if (!files)
2110 goto out;
2111 rcu_read_lock();
2112 for (fd = filp->f_pos-2;
2113 fd < files_fdtable(files)->max_fds;
2114 fd++, filp->f_pos++) {
2115 char name[PROC_NUMBUF];
2116 int len;
2117
2118 if (!fcheck_files(files, fd))
2119 continue;
2120 rcu_read_unlock();
2121
2122 len = snprintf(name, sizeof(name), "%d", fd);
2123 if (proc_fill_cache(filp, dirent, filldir,
2124 name, len, instantiate,
2125 p, &fd) < 0) {
2126 rcu_read_lock();
2127 break;
2128 }
2129 rcu_read_lock();
2130 }
2131 rcu_read_unlock();
2132 put_files_struct(files);
2133 }
2134out:
2135 put_task_struct(p);
2136out_no_task:
2137 return retval;
2138}
2139
2140static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
2141 struct nameidata *nd)
2142{
2143 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
2144}
2145
2146static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
2147{
2148 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
2149}
2150
2151static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
2152 size_t len, loff_t *ppos)
2153{
2154 char tmp[PROC_FDINFO_MAX];
2155 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
2156 if (!err)
2157 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
2158 return err;
2159}
2160
2161static const struct file_operations proc_fdinfo_file_operations = {
2162 .open = nonseekable_open,
2163 .read = proc_fdinfo_read,
2164 .llseek = no_llseek,
2165};
2166
2167static const struct file_operations proc_fd_operations = {
2168 .read = generic_read_dir,
2169 .readdir = proc_readfd,
2170 .llseek = default_llseek,
2171};
2172
2173/*
2174 * /proc/pid/fd needs a special permission handler so that a process can still
2175 * access /proc/self/fd after it has executed a setuid().
2176 */
2177static int proc_fd_permission(struct inode *inode, int mask)
2178{
2179 int rv = generic_permission(inode, mask);
2180 if (rv == 0)
2181 return 0;
2182 if (task_pid(current) == proc_pid(inode))
2183 rv = 0;
2184 return rv;
2185}
2186
2187/*
2188 * proc directories can do almost nothing..
2189 */
2190static const struct inode_operations proc_fd_inode_operations = {
2191 .lookup = proc_lookupfd,
2192 .permission = proc_fd_permission,
2193 .setattr = proc_setattr,
2194};
2195
2196static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2197 struct dentry *dentry, struct task_struct *task, const void *ptr)
2198{
2199 unsigned fd = *(unsigned *)ptr;
2200 struct inode *inode;
2201 struct proc_inode *ei;
2202 struct dentry *error = ERR_PTR(-ENOENT);
2203
2204 inode = proc_pid_make_inode(dir->i_sb, task);
2205 if (!inode)
2206 goto out;
2207 ei = PROC_I(inode);
2208 ei->fd = fd;
2209 inode->i_mode = S_IFREG | S_IRUSR;
2210 inode->i_fop = &proc_fdinfo_file_operations;
2211 d_set_d_op(dentry, &tid_fd_dentry_operations);
2212 d_add(dentry, inode);
2213 /* Close the race of the process dying before we return the dentry */
2214 if (tid_fd_revalidate(dentry, NULL))
2215 error = NULL;
2216
2217 out:
2218 return error;
2219}
2220
2221static struct dentry *proc_lookupfdinfo(struct inode *dir,
2222 struct dentry *dentry,
2223 struct nameidata *nd)
2224{
2225 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2226}
2227
2228static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2229{
2230 return proc_readfd_common(filp, dirent, filldir,
2231 proc_fdinfo_instantiate);
2232}
2233
2234static const struct file_operations proc_fdinfo_operations = {
2235 .read = generic_read_dir,
2236 .readdir = proc_readfdinfo,
2237 .llseek = default_llseek,
2238};
2239
2240/*
2241 * proc directories can do almost nothing..
2242 */
2243static const struct inode_operations proc_fdinfo_inode_operations = {
2244 .lookup = proc_lookupfdinfo,
2245 .setattr = proc_setattr,
2246};
2247
2248
2249static struct dentry *proc_pident_instantiate(struct inode *dir,
2250 struct dentry *dentry, struct task_struct *task, const void *ptr)
2251{
2252 const struct pid_entry *p = ptr;
2253 struct inode *inode;
2254 struct proc_inode *ei;
2255 struct dentry *error = ERR_PTR(-ENOENT);
2256
2257 inode = proc_pid_make_inode(dir->i_sb, task);
2258 if (!inode)
2259 goto out;
2260
2261 ei = PROC_I(inode);
2262 inode->i_mode = p->mode;
2263 if (S_ISDIR(inode->i_mode))
2264 inode->i_nlink = 2; /* Use getattr to fix if necessary */
2265 if (p->iop)
2266 inode->i_op = p->iop;
2267 if (p->fop)
2268 inode->i_fop = p->fop;
2269 ei->op = p->op;
2270 d_set_d_op(dentry, &pid_dentry_operations);
2271 d_add(dentry, inode);
2272 /* Close the race of the process dying before we return the dentry */
2273 if (pid_revalidate(dentry, NULL))
2274 error = NULL;
2275out:
2276 return error;
2277}
2278
2279static struct dentry *proc_pident_lookup(struct inode *dir,
2280 struct dentry *dentry,
2281 const struct pid_entry *ents,
2282 unsigned int nents)
2283{
2284 struct dentry *error;
2285 struct task_struct *task = get_proc_task(dir);
2286 const struct pid_entry *p, *last;
2287
2288 error = ERR_PTR(-ENOENT);
2289
2290 if (!task)
2291 goto out_no_task;
2292
2293 /*
2294 * Yes, it does not scale. And it should not. Don't add
2295 * new entries into /proc/<tgid>/ without very good reasons.
2296 */
2297 last = &ents[nents - 1];
2298 for (p = ents; p <= last; p++) {
2299 if (p->len != dentry->d_name.len)
2300 continue;
2301 if (!memcmp(dentry->d_name.name, p->name, p->len))
2302 break;
2303 }
2304 if (p > last)
2305 goto out;
2306
2307 error = proc_pident_instantiate(dir, dentry, task, p);
2308out:
2309 put_task_struct(task);
2310out_no_task:
2311 return error;
2312}
2313
2314static int proc_pident_fill_cache(struct file *filp, void *dirent,
2315 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2316{
2317 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2318 proc_pident_instantiate, task, p);
2319}
2320
2321static int proc_pident_readdir(struct file *filp,
2322 void *dirent, filldir_t filldir,
2323 const struct pid_entry *ents, unsigned int nents)
2324{
2325 int i;
2326 struct dentry *dentry = filp->f_path.dentry;
2327 struct inode *inode = dentry->d_inode;
2328 struct task_struct *task = get_proc_task(inode);
2329 const struct pid_entry *p, *last;
2330 ino_t ino;
2331 int ret;
2332
2333 ret = -ENOENT;
2334 if (!task)
2335 goto out_no_task;
2336
2337 ret = 0;
2338 i = filp->f_pos;
2339 switch (i) {
2340 case 0:
2341 ino = inode->i_ino;
2342 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2343 goto out;
2344 i++;
2345 filp->f_pos++;
2346 /* fall through */
2347 case 1:
2348 ino = parent_ino(dentry);
2349 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2350 goto out;
2351 i++;
2352 filp->f_pos++;
2353 /* fall through */
2354 default:
2355 i -= 2;
2356 if (i >= nents) {
2357 ret = 1;
2358 goto out;
2359 }
2360 p = ents + i;
2361 last = &ents[nents - 1];
2362 while (p <= last) {
2363 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2364 goto out;
2365 filp->f_pos++;
2366 p++;
2367 }
2368 }
2369
2370 ret = 1;
2371out:
2372 put_task_struct(task);
2373out_no_task:
2374 return ret;
2375}
2376
2377#ifdef CONFIG_SECURITY
2378static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2379 size_t count, loff_t *ppos)
2380{
2381 struct inode * inode = file->f_path.dentry->d_inode;
2382 char *p = NULL;
2383 ssize_t length;
2384 struct task_struct *task = get_proc_task(inode);
2385
2386 if (!task)
2387 return -ESRCH;
2388
2389 length = security_getprocattr(task,
2390 (char*)file->f_path.dentry->d_name.name,
2391 &p);
2392 put_task_struct(task);
2393 if (length > 0)
2394 length = simple_read_from_buffer(buf, count, ppos, p, length);
2395 kfree(p);
2396 return length;
2397}
2398
2399static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2400 size_t count, loff_t *ppos)
2401{
2402 struct inode * inode = file->f_path.dentry->d_inode;
2403 char *page;
2404 ssize_t length;
2405 struct task_struct *task = get_proc_task(inode);
2406
2407 length = -ESRCH;
2408 if (!task)
2409 goto out_no_task;
2410 if (count > PAGE_SIZE)
2411 count = PAGE_SIZE;
2412
2413 /* No partial writes. */
2414 length = -EINVAL;
2415 if (*ppos != 0)
2416 goto out;
2417
2418 length = -ENOMEM;
2419 page = (char*)__get_free_page(GFP_TEMPORARY);
2420 if (!page)
2421 goto out;
2422
2423 length = -EFAULT;
2424 if (copy_from_user(page, buf, count))
2425 goto out_free;
2426
2427 /* Guard against adverse ptrace interaction */
2428 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2429 if (length < 0)
2430 goto out_free;
2431
2432 length = security_setprocattr(task,
2433 (char*)file->f_path.dentry->d_name.name,
2434 (void*)page, count);
2435 mutex_unlock(&task->signal->cred_guard_mutex);
2436out_free:
2437 free_page((unsigned long) page);
2438out:
2439 put_task_struct(task);
2440out_no_task:
2441 return length;
2442}
2443
2444static const struct file_operations proc_pid_attr_operations = {
2445 .read = proc_pid_attr_read,
2446 .write = proc_pid_attr_write,
2447 .llseek = generic_file_llseek,
2448};
2449
2450static const struct pid_entry attr_dir_stuff[] = {
2451 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2452 REG("prev", S_IRUGO, proc_pid_attr_operations),
2453 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2454 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2455 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2456 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2457};
2458
2459static int proc_attr_dir_readdir(struct file * filp,
2460 void * dirent, filldir_t filldir)
2461{
2462 return proc_pident_readdir(filp,dirent,filldir,
2463 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2464}
2465
2466static const struct file_operations proc_attr_dir_operations = {
2467 .read = generic_read_dir,
2468 .readdir = proc_attr_dir_readdir,
2469 .llseek = default_llseek,
2470};
2471
2472static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2473 struct dentry *dentry, struct nameidata *nd)
2474{
2475 return proc_pident_lookup(dir, dentry,
2476 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2477}
2478
2479static const struct inode_operations proc_attr_dir_inode_operations = {
2480 .lookup = proc_attr_dir_lookup,
2481 .getattr = pid_getattr,
2482 .setattr = proc_setattr,
2483};
2484
2485#endif
2486
2487#ifdef CONFIG_ELF_CORE
2488static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2489 size_t count, loff_t *ppos)
2490{
2491 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2492 struct mm_struct *mm;
2493 char buffer[PROC_NUMBUF];
2494 size_t len;
2495 int ret;
2496
2497 if (!task)
2498 return -ESRCH;
2499
2500 ret = 0;
2501 mm = get_task_mm(task);
2502 if (mm) {
2503 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2504 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2505 MMF_DUMP_FILTER_SHIFT));
2506 mmput(mm);
2507 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2508 }
2509
2510 put_task_struct(task);
2511
2512 return ret;
2513}
2514
2515static ssize_t proc_coredump_filter_write(struct file *file,
2516 const char __user *buf,
2517 size_t count,
2518 loff_t *ppos)
2519{
2520 struct task_struct *task;
2521 struct mm_struct *mm;
2522 char buffer[PROC_NUMBUF], *end;
2523 unsigned int val;
2524 int ret;
2525 int i;
2526 unsigned long mask;
2527
2528 ret = -EFAULT;
2529 memset(buffer, 0, sizeof(buffer));
2530 if (count > sizeof(buffer) - 1)
2531 count = sizeof(buffer) - 1;
2532 if (copy_from_user(buffer, buf, count))
2533 goto out_no_task;
2534
2535 ret = -EINVAL;
2536 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2537 if (*end == '\n')
2538 end++;
2539 if (end - buffer == 0)
2540 goto out_no_task;
2541
2542 ret = -ESRCH;
2543 task = get_proc_task(file->f_dentry->d_inode);
2544 if (!task)
2545 goto out_no_task;
2546
2547 ret = end - buffer;
2548 mm = get_task_mm(task);
2549 if (!mm)
2550 goto out_no_mm;
2551
2552 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2553 if (val & mask)
2554 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2555 else
2556 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2557 }
2558
2559 mmput(mm);
2560 out_no_mm:
2561 put_task_struct(task);
2562 out_no_task:
2563 return ret;
2564}
2565
2566static const struct file_operations proc_coredump_filter_operations = {
2567 .read = proc_coredump_filter_read,
2568 .write = proc_coredump_filter_write,
2569 .llseek = generic_file_llseek,
2570};
2571#endif
2572
2573/*
2574 * /proc/self:
2575 */
2576static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2577 int buflen)
2578{
2579 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2580 pid_t tgid = task_tgid_nr_ns(current, ns);
2581 char tmp[PROC_NUMBUF];
2582 if (!tgid)
2583 return -ENOENT;
2584 sprintf(tmp, "%d", tgid);
2585 return vfs_readlink(dentry,buffer,buflen,tmp);
2586}
2587
2588static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2589{
2590 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2591 pid_t tgid = task_tgid_nr_ns(current, ns);
2592 char *name = ERR_PTR(-ENOENT);
2593 if (tgid) {
2594 name = __getname();
2595 if (!name)
2596 name = ERR_PTR(-ENOMEM);
2597 else
2598 sprintf(name, "%d", tgid);
2599 }
2600 nd_set_link(nd, name);
2601 return NULL;
2602}
2603
2604static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2605 void *cookie)
2606{
2607 char *s = nd_get_link(nd);
2608 if (!IS_ERR(s))
2609 __putname(s);
2610}
2611
2612static const struct inode_operations proc_self_inode_operations = {
2613 .readlink = proc_self_readlink,
2614 .follow_link = proc_self_follow_link,
2615 .put_link = proc_self_put_link,
2616};
2617
2618/*
2619 * proc base
2620 *
2621 * These are the directory entries in the root directory of /proc
2622 * that properly belong to the /proc filesystem, as they describe
2623 * describe something that is process related.
2624 */
2625static const struct pid_entry proc_base_stuff[] = {
2626 NOD("self", S_IFLNK|S_IRWXUGO,
2627 &proc_self_inode_operations, NULL, {}),
2628};
2629
2630static struct dentry *proc_base_instantiate(struct inode *dir,
2631 struct dentry *dentry, struct task_struct *task, const void *ptr)
2632{
2633 const struct pid_entry *p = ptr;
2634 struct inode *inode;
2635 struct proc_inode *ei;
2636 struct dentry *error;
2637
2638 /* Allocate the inode */
2639 error = ERR_PTR(-ENOMEM);
2640 inode = new_inode(dir->i_sb);
2641 if (!inode)
2642 goto out;
2643
2644 /* Initialize the inode */
2645 ei = PROC_I(inode);
2646 inode->i_ino = get_next_ino();
2647 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2648
2649 /*
2650 * grab the reference to the task.
2651 */
2652 ei->pid = get_task_pid(task, PIDTYPE_PID);
2653 if (!ei->pid)
2654 goto out_iput;
2655
2656 inode->i_mode = p->mode;
2657 if (S_ISDIR(inode->i_mode))
2658 inode->i_nlink = 2;
2659 if (S_ISLNK(inode->i_mode))
2660 inode->i_size = 64;
2661 if (p->iop)
2662 inode->i_op = p->iop;
2663 if (p->fop)
2664 inode->i_fop = p->fop;
2665 ei->op = p->op;
2666 d_add(dentry, inode);
2667 error = NULL;
2668out:
2669 return error;
2670out_iput:
2671 iput(inode);
2672 goto out;
2673}
2674
2675static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2676{
2677 struct dentry *error;
2678 struct task_struct *task = get_proc_task(dir);
2679 const struct pid_entry *p, *last;
2680
2681 error = ERR_PTR(-ENOENT);
2682
2683 if (!task)
2684 goto out_no_task;
2685
2686 /* Lookup the directory entry */
2687 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2688 for (p = proc_base_stuff; p <= last; p++) {
2689 if (p->len != dentry->d_name.len)
2690 continue;
2691 if (!memcmp(dentry->d_name.name, p->name, p->len))
2692 break;
2693 }
2694 if (p > last)
2695 goto out;
2696
2697 error = proc_base_instantiate(dir, dentry, task, p);
2698
2699out:
2700 put_task_struct(task);
2701out_no_task:
2702 return error;
2703}
2704
2705static int proc_base_fill_cache(struct file *filp, void *dirent,
2706 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2707{
2708 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2709 proc_base_instantiate, task, p);
2710}
2711
2712#ifdef CONFIG_TASK_IO_ACCOUNTING
2713static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2714{
2715 struct task_io_accounting acct = task->ioac;
2716 unsigned long flags;
2717 int result;
2718
2719 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2720 if (result)
2721 return result;
2722
2723 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2724 result = -EACCES;
2725 goto out_unlock;
2726 }
2727
2728 if (whole && lock_task_sighand(task, &flags)) {
2729 struct task_struct *t = task;
2730
2731 task_io_accounting_add(&acct, &task->signal->ioac);
2732 while_each_thread(task, t)
2733 task_io_accounting_add(&acct, &t->ioac);
2734
2735 unlock_task_sighand(task, &flags);
2736 }
2737 result = sprintf(buffer,
2738 "rchar: %llu\n"
2739 "wchar: %llu\n"
2740 "syscr: %llu\n"
2741 "syscw: %llu\n"
2742 "read_bytes: %llu\n"
2743 "write_bytes: %llu\n"
2744 "cancelled_write_bytes: %llu\n",
2745 (unsigned long long)acct.rchar,
2746 (unsigned long long)acct.wchar,
2747 (unsigned long long)acct.syscr,
2748 (unsigned long long)acct.syscw,
2749 (unsigned long long)acct.read_bytes,
2750 (unsigned long long)acct.write_bytes,
2751 (unsigned long long)acct.cancelled_write_bytes);
2752out_unlock:
2753 mutex_unlock(&task->signal->cred_guard_mutex);
2754 return result;
2755}
2756
2757static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2758{
2759 return do_io_accounting(task, buffer, 0);
2760}
2761
2762static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2763{
2764 return do_io_accounting(task, buffer, 1);
2765}
2766#endif /* CONFIG_TASK_IO_ACCOUNTING */
2767
2768static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2769 struct pid *pid, struct task_struct *task)
2770{
2771 int err = lock_trace(task);
2772 if (!err) {
2773 seq_printf(m, "%08x\n", task->personality);
2774 unlock_trace(task);
2775 }
2776 return err;
2777}
2778
2779/*
2780 * Thread groups
2781 */
2782static const struct file_operations proc_task_operations;
2783static const struct inode_operations proc_task_inode_operations;
2784
2785static const struct pid_entry tgid_base_stuff[] = {
2786 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2787 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2788 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2789 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2790#ifdef CONFIG_NET
2791 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2792#endif
2793 REG("environ", S_IRUSR, proc_environ_operations),
2794 INF("auxv", S_IRUSR, proc_pid_auxv),
2795 ONE("status", S_IRUGO, proc_pid_status),
2796 ONE("personality", S_IRUGO, proc_pid_personality),
2797 INF("limits", S_IRUGO, proc_pid_limits),
2798#ifdef CONFIG_SCHED_DEBUG
2799 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2800#endif
2801#ifdef CONFIG_SCHED_AUTOGROUP
2802 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2803#endif
2804 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2805#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2806 INF("syscall", S_IRUGO, proc_pid_syscall),
2807#endif
2808 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2809 ONE("stat", S_IRUGO, proc_tgid_stat),
2810 ONE("statm", S_IRUGO, proc_pid_statm),
2811 REG("maps", S_IRUGO, proc_maps_operations),
2812#ifdef CONFIG_NUMA
2813 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
2814#endif
2815 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2816 LNK("cwd", proc_cwd_link),
2817 LNK("root", proc_root_link),
2818 LNK("exe", proc_exe_link),
2819 REG("mounts", S_IRUGO, proc_mounts_operations),
2820 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2821 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2822#ifdef CONFIG_PROC_PAGE_MONITOR
2823 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2824 REG("smaps", S_IRUGO, proc_smaps_operations),
2825 REG("pagemap", S_IRUGO, proc_pagemap_operations),
2826#endif
2827#ifdef CONFIG_SECURITY
2828 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2829#endif
2830#ifdef CONFIG_KALLSYMS
2831 INF("wchan", S_IRUGO, proc_pid_wchan),
2832#endif
2833#ifdef CONFIG_STACKTRACE
2834 ONE("stack", S_IRUGO, proc_pid_stack),
2835#endif
2836#ifdef CONFIG_SCHEDSTATS
2837 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2838#endif
2839#ifdef CONFIG_LATENCYTOP
2840 REG("latency", S_IRUGO, proc_lstats_operations),
2841#endif
2842#ifdef CONFIG_PROC_PID_CPUSET
2843 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2844#endif
2845#ifdef CONFIG_CGROUPS
2846 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2847#endif
2848 INF("oom_score", S_IRUGO, proc_oom_score),
2849 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2850 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2851#ifdef CONFIG_AUDITSYSCALL
2852 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2853 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2854#endif
2855#ifdef CONFIG_FAULT_INJECTION
2856 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2857#endif
2858#ifdef CONFIG_ELF_CORE
2859 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2860#endif
2861#ifdef CONFIG_TASK_IO_ACCOUNTING
2862 INF("io", S_IRUSR, proc_tgid_io_accounting),
2863#endif
2864#ifdef CONFIG_HARDWALL
2865 INF("hardwall", S_IRUGO, proc_pid_hardwall),
2866#endif
2867};
2868
2869static int proc_tgid_base_readdir(struct file * filp,
2870 void * dirent, filldir_t filldir)
2871{
2872 return proc_pident_readdir(filp,dirent,filldir,
2873 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2874}
2875
2876static const struct file_operations proc_tgid_base_operations = {
2877 .read = generic_read_dir,
2878 .readdir = proc_tgid_base_readdir,
2879 .llseek = default_llseek,
2880};
2881
2882static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2883 return proc_pident_lookup(dir, dentry,
2884 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2885}
2886
2887static const struct inode_operations proc_tgid_base_inode_operations = {
2888 .lookup = proc_tgid_base_lookup,
2889 .getattr = pid_getattr,
2890 .setattr = proc_setattr,
2891};
2892
2893static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2894{
2895 struct dentry *dentry, *leader, *dir;
2896 char buf[PROC_NUMBUF];
2897 struct qstr name;
2898
2899 name.name = buf;
2900 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2901 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2902 if (dentry) {
2903 shrink_dcache_parent(dentry);
2904 d_drop(dentry);
2905 dput(dentry);
2906 }
2907
2908 name.name = buf;
2909 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2910 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2911 if (!leader)
2912 goto out;
2913
2914 name.name = "task";
2915 name.len = strlen(name.name);
2916 dir = d_hash_and_lookup(leader, &name);
2917 if (!dir)
2918 goto out_put_leader;
2919
2920 name.name = buf;
2921 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2922 dentry = d_hash_and_lookup(dir, &name);
2923 if (dentry) {
2924 shrink_dcache_parent(dentry);
2925 d_drop(dentry);
2926 dput(dentry);
2927 }
2928
2929 dput(dir);
2930out_put_leader:
2931 dput(leader);
2932out:
2933 return;
2934}
2935
2936/**
2937 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2938 * @task: task that should be flushed.
2939 *
2940 * When flushing dentries from proc, one needs to flush them from global
2941 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2942 * in. This call is supposed to do all of this job.
2943 *
2944 * Looks in the dcache for
2945 * /proc/@pid
2946 * /proc/@tgid/task/@pid
2947 * if either directory is present flushes it and all of it'ts children
2948 * from the dcache.
2949 *
2950 * It is safe and reasonable to cache /proc entries for a task until
2951 * that task exits. After that they just clog up the dcache with
2952 * useless entries, possibly causing useful dcache entries to be
2953 * flushed instead. This routine is proved to flush those useless
2954 * dcache entries at process exit time.
2955 *
2956 * NOTE: This routine is just an optimization so it does not guarantee
2957 * that no dcache entries will exist at process exit time it
2958 * just makes it very unlikely that any will persist.
2959 */
2960
2961void proc_flush_task(struct task_struct *task)
2962{
2963 int i;
2964 struct pid *pid, *tgid;
2965 struct upid *upid;
2966
2967 pid = task_pid(task);
2968 tgid = task_tgid(task);
2969
2970 for (i = 0; i <= pid->level; i++) {
2971 upid = &pid->numbers[i];
2972 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2973 tgid->numbers[i].nr);
2974 }
2975
2976 upid = &pid->numbers[pid->level];
2977 if (upid->nr == 1)
2978 pid_ns_release_proc(upid->ns);
2979}
2980
2981static struct dentry *proc_pid_instantiate(struct inode *dir,
2982 struct dentry * dentry,
2983 struct task_struct *task, const void *ptr)
2984{
2985 struct dentry *error = ERR_PTR(-ENOENT);
2986 struct inode *inode;
2987
2988 inode = proc_pid_make_inode(dir->i_sb, task);
2989 if (!inode)
2990 goto out;
2991
2992 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2993 inode->i_op = &proc_tgid_base_inode_operations;
2994 inode->i_fop = &proc_tgid_base_operations;
2995 inode->i_flags|=S_IMMUTABLE;
2996
2997 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
2998 ARRAY_SIZE(tgid_base_stuff));
2999
3000 d_set_d_op(dentry, &pid_dentry_operations);
3001
3002 d_add(dentry, inode);
3003 /* Close the race of the process dying before we return the dentry */
3004 if (pid_revalidate(dentry, NULL))
3005 error = NULL;
3006out:
3007 return error;
3008}
3009
3010struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3011{
3012 struct dentry *result;
3013 struct task_struct *task;
3014 unsigned tgid;
3015 struct pid_namespace *ns;
3016
3017 result = proc_base_lookup(dir, dentry);
3018 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
3019 goto out;
3020
3021 tgid = name_to_int(dentry);
3022 if (tgid == ~0U)
3023 goto out;
3024
3025 ns = dentry->d_sb->s_fs_info;
3026 rcu_read_lock();
3027 task = find_task_by_pid_ns(tgid, ns);
3028 if (task)
3029 get_task_struct(task);
3030 rcu_read_unlock();
3031 if (!task)
3032 goto out;
3033
3034 result = proc_pid_instantiate(dir, dentry, task, NULL);
3035 put_task_struct(task);
3036out:
3037 return result;
3038}
3039
3040/*
3041 * Find the first task with tgid >= tgid
3042 *
3043 */
3044struct tgid_iter {
3045 unsigned int tgid;
3046 struct task_struct *task;
3047};
3048static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3049{
3050 struct pid *pid;
3051
3052 if (iter.task)
3053 put_task_struct(iter.task);
3054 rcu_read_lock();
3055retry:
3056 iter.task = NULL;
3057 pid = find_ge_pid(iter.tgid, ns);
3058 if (pid) {
3059 iter.tgid = pid_nr_ns(pid, ns);
3060 iter.task = pid_task(pid, PIDTYPE_PID);
3061 /* What we to know is if the pid we have find is the
3062 * pid of a thread_group_leader. Testing for task
3063 * being a thread_group_leader is the obvious thing
3064 * todo but there is a window when it fails, due to
3065 * the pid transfer logic in de_thread.
3066 *
3067 * So we perform the straight forward test of seeing
3068 * if the pid we have found is the pid of a thread
3069 * group leader, and don't worry if the task we have
3070 * found doesn't happen to be a thread group leader.
3071 * As we don't care in the case of readdir.
3072 */
3073 if (!iter.task || !has_group_leader_pid(iter.task)) {
3074 iter.tgid += 1;
3075 goto retry;
3076 }
3077 get_task_struct(iter.task);
3078 }
3079 rcu_read_unlock();
3080 return iter;
3081}
3082
3083#define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
3084
3085static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3086 struct tgid_iter iter)
3087{
3088 char name[PROC_NUMBUF];
3089 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
3090 return proc_fill_cache(filp, dirent, filldir, name, len,
3091 proc_pid_instantiate, iter.task, NULL);
3092}
3093
3094/* for the /proc/ directory itself, after non-process stuff has been done */
3095int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
3096{
3097 unsigned int nr;
3098 struct task_struct *reaper;
3099 struct tgid_iter iter;
3100 struct pid_namespace *ns;
3101
3102 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
3103 goto out_no_task;
3104 nr = filp->f_pos - FIRST_PROCESS_ENTRY;
3105
3106 reaper = get_proc_task(filp->f_path.dentry->d_inode);
3107 if (!reaper)
3108 goto out_no_task;
3109
3110 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
3111 const struct pid_entry *p = &proc_base_stuff[nr];
3112 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
3113 goto out;
3114 }
3115
3116 ns = filp->f_dentry->d_sb->s_fs_info;
3117 iter.task = NULL;
3118 iter.tgid = filp->f_pos - TGID_OFFSET;
3119 for (iter = next_tgid(ns, iter);
3120 iter.task;
3121 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3122 filp->f_pos = iter.tgid + TGID_OFFSET;
3123 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
3124 put_task_struct(iter.task);
3125 goto out;
3126 }
3127 }
3128 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3129out:
3130 put_task_struct(reaper);
3131out_no_task:
3132 return 0;
3133}
3134
3135/*
3136 * Tasks
3137 */
3138static const struct pid_entry tid_base_stuff[] = {
3139 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3140 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3141 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3142 REG("environ", S_IRUSR, proc_environ_operations),
3143 INF("auxv", S_IRUSR, proc_pid_auxv),
3144 ONE("status", S_IRUGO, proc_pid_status),
3145 ONE("personality", S_IRUGO, proc_pid_personality),
3146 INF("limits", S_IRUGO, proc_pid_limits),
3147#ifdef CONFIG_SCHED_DEBUG
3148 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3149#endif
3150 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3151#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3152 INF("syscall", S_IRUGO, proc_pid_syscall),
3153#endif
3154 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3155 ONE("stat", S_IRUGO, proc_tid_stat),
3156 ONE("statm", S_IRUGO, proc_pid_statm),
3157 REG("maps", S_IRUGO, proc_maps_operations),
3158#ifdef CONFIG_NUMA
3159 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
3160#endif
3161 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3162 LNK("cwd", proc_cwd_link),
3163 LNK("root", proc_root_link),
3164 LNK("exe", proc_exe_link),
3165 REG("mounts", S_IRUGO, proc_mounts_operations),
3166 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3167#ifdef CONFIG_PROC_PAGE_MONITOR
3168 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3169 REG("smaps", S_IRUGO, proc_smaps_operations),
3170 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3171#endif
3172#ifdef CONFIG_SECURITY
3173 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3174#endif
3175#ifdef CONFIG_KALLSYMS
3176 INF("wchan", S_IRUGO, proc_pid_wchan),
3177#endif
3178#ifdef CONFIG_STACKTRACE
3179 ONE("stack", S_IRUGO, proc_pid_stack),
3180#endif
3181#ifdef CONFIG_SCHEDSTATS
3182 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3183#endif
3184#ifdef CONFIG_LATENCYTOP
3185 REG("latency", S_IRUGO, proc_lstats_operations),
3186#endif
3187#ifdef CONFIG_PROC_PID_CPUSET
3188 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3189#endif
3190#ifdef CONFIG_CGROUPS
3191 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3192#endif
3193 INF("oom_score", S_IRUGO, proc_oom_score),
3194 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3195 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3196#ifdef CONFIG_AUDITSYSCALL
3197 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3198 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3199#endif
3200#ifdef CONFIG_FAULT_INJECTION
3201 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3202#endif
3203#ifdef CONFIG_TASK_IO_ACCOUNTING
3204 INF("io", S_IRUSR, proc_tid_io_accounting),
3205#endif
3206#ifdef CONFIG_HARDWALL
3207 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3208#endif
3209};
3210
3211static int proc_tid_base_readdir(struct file * filp,
3212 void * dirent, filldir_t filldir)
3213{
3214 return proc_pident_readdir(filp,dirent,filldir,
3215 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3216}
3217
3218static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3219 return proc_pident_lookup(dir, dentry,
3220 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3221}
3222
3223static const struct file_operations proc_tid_base_operations = {
3224 .read = generic_read_dir,
3225 .readdir = proc_tid_base_readdir,
3226 .llseek = default_llseek,
3227};
3228
3229static const struct inode_operations proc_tid_base_inode_operations = {
3230 .lookup = proc_tid_base_lookup,
3231 .getattr = pid_getattr,
3232 .setattr = proc_setattr,
3233};
3234
3235static struct dentry *proc_task_instantiate(struct inode *dir,
3236 struct dentry *dentry, struct task_struct *task, const void *ptr)
3237{
3238 struct dentry *error = ERR_PTR(-ENOENT);
3239 struct inode *inode;
3240 inode = proc_pid_make_inode(dir->i_sb, task);
3241
3242 if (!inode)
3243 goto out;
3244 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3245 inode->i_op = &proc_tid_base_inode_operations;
3246 inode->i_fop = &proc_tid_base_operations;
3247 inode->i_flags|=S_IMMUTABLE;
3248
3249 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
3250 ARRAY_SIZE(tid_base_stuff));
3251
3252 d_set_d_op(dentry, &pid_dentry_operations);
3253
3254 d_add(dentry, inode);
3255 /* Close the race of the process dying before we return the dentry */
3256 if (pid_revalidate(dentry, NULL))
3257 error = NULL;
3258out:
3259 return error;
3260}
3261
3262static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3263{
3264 struct dentry *result = ERR_PTR(-ENOENT);
3265 struct task_struct *task;
3266 struct task_struct *leader = get_proc_task(dir);
3267 unsigned tid;
3268 struct pid_namespace *ns;
3269
3270 if (!leader)
3271 goto out_no_task;
3272
3273 tid = name_to_int(dentry);
3274 if (tid == ~0U)
3275 goto out;
3276
3277 ns = dentry->d_sb->s_fs_info;
3278 rcu_read_lock();
3279 task = find_task_by_pid_ns(tid, ns);
3280 if (task)
3281 get_task_struct(task);
3282 rcu_read_unlock();
3283 if (!task)
3284 goto out;
3285 if (!same_thread_group(leader, task))
3286 goto out_drop_task;
3287
3288 result = proc_task_instantiate(dir, dentry, task, NULL);
3289out_drop_task:
3290 put_task_struct(task);
3291out:
3292 put_task_struct(leader);
3293out_no_task:
3294 return result;
3295}
3296
3297/*
3298 * Find the first tid of a thread group to return to user space.
3299 *
3300 * Usually this is just the thread group leader, but if the users
3301 * buffer was too small or there was a seek into the middle of the
3302 * directory we have more work todo.
3303 *
3304 * In the case of a short read we start with find_task_by_pid.
3305 *
3306 * In the case of a seek we start with the leader and walk nr
3307 * threads past it.
3308 */
3309static struct task_struct *first_tid(struct task_struct *leader,
3310 int tid, int nr, struct pid_namespace *ns)
3311{
3312 struct task_struct *pos;
3313
3314 rcu_read_lock();
3315 /* Attempt to start with the pid of a thread */
3316 if (tid && (nr > 0)) {
3317 pos = find_task_by_pid_ns(tid, ns);
3318 if (pos && (pos->group_leader == leader))
3319 goto found;
3320 }
3321
3322 /* If nr exceeds the number of threads there is nothing todo */
3323 pos = NULL;
3324 if (nr && nr >= get_nr_threads(leader))
3325 goto out;
3326
3327 /* If we haven't found our starting place yet start
3328 * with the leader and walk nr threads forward.
3329 */
3330 for (pos = leader; nr > 0; --nr) {
3331 pos = next_thread(pos);
3332 if (pos == leader) {
3333 pos = NULL;
3334 goto out;
3335 }
3336 }
3337found:
3338 get_task_struct(pos);
3339out:
3340 rcu_read_unlock();
3341 return pos;
3342}
3343
3344/*
3345 * Find the next thread in the thread list.
3346 * Return NULL if there is an error or no next thread.
3347 *
3348 * The reference to the input task_struct is released.
3349 */
3350static struct task_struct *next_tid(struct task_struct *start)
3351{
3352 struct task_struct *pos = NULL;
3353 rcu_read_lock();
3354 if (pid_alive(start)) {
3355 pos = next_thread(start);
3356 if (thread_group_leader(pos))
3357 pos = NULL;
3358 else
3359 get_task_struct(pos);
3360 }
3361 rcu_read_unlock();
3362 put_task_struct(start);
3363 return pos;
3364}
3365
3366static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3367 struct task_struct *task, int tid)
3368{
3369 char name[PROC_NUMBUF];
3370 int len = snprintf(name, sizeof(name), "%d", tid);
3371 return proc_fill_cache(filp, dirent, filldir, name, len,
3372 proc_task_instantiate, task, NULL);
3373}
3374
3375/* for the /proc/TGID/task/ directories */
3376static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3377{
3378 struct dentry *dentry = filp->f_path.dentry;
3379 struct inode *inode = dentry->d_inode;
3380 struct task_struct *leader = NULL;
3381 struct task_struct *task;
3382 int retval = -ENOENT;
3383 ino_t ino;
3384 int tid;
3385 struct pid_namespace *ns;
3386
3387 task = get_proc_task(inode);
3388 if (!task)
3389 goto out_no_task;
3390 rcu_read_lock();
3391 if (pid_alive(task)) {
3392 leader = task->group_leader;
3393 get_task_struct(leader);
3394 }
3395 rcu_read_unlock();
3396 put_task_struct(task);
3397 if (!leader)
3398 goto out_no_task;
3399 retval = 0;
3400
3401 switch ((unsigned long)filp->f_pos) {
3402 case 0:
3403 ino = inode->i_ino;
3404 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3405 goto out;
3406 filp->f_pos++;
3407 /* fall through */
3408 case 1:
3409 ino = parent_ino(dentry);
3410 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3411 goto out;
3412 filp->f_pos++;
3413 /* fall through */
3414 }
3415
3416 /* f_version caches the tgid value that the last readdir call couldn't
3417 * return. lseek aka telldir automagically resets f_version to 0.
3418 */
3419 ns = filp->f_dentry->d_sb->s_fs_info;
3420 tid = (int)filp->f_version;
3421 filp->f_version = 0;
3422 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3423 task;
3424 task = next_tid(task), filp->f_pos++) {
3425 tid = task_pid_nr_ns(task, ns);
3426 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3427 /* returning this tgid failed, save it as the first
3428 * pid for the next readir call */
3429 filp->f_version = (u64)tid;
3430 put_task_struct(task);
3431 break;
3432 }
3433 }
3434out:
3435 put_task_struct(leader);
3436out_no_task:
3437 return retval;
3438}
3439
3440static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3441{
3442 struct inode *inode = dentry->d_inode;
3443 struct task_struct *p = get_proc_task(inode);
3444 generic_fillattr(inode, stat);
3445
3446 if (p) {
3447 stat->nlink += get_nr_threads(p);
3448 put_task_struct(p);
3449 }
3450
3451 return 0;
3452}
3453
3454static const struct inode_operations proc_task_inode_operations = {
3455 .lookup = proc_task_lookup,
3456 .getattr = proc_task_getattr,
3457 .setattr = proc_setattr,
3458};
3459
3460static const struct file_operations proc_task_operations = {
3461 .read = generic_read_dir,
3462 .readdir = proc_task_readdir,
3463 .llseek = default_llseek,
3464};
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/proc/base.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 * proc base directory handling functions
8 *
9 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
10 * Instead of using magical inumbers to determine the kind of object
11 * we allocate and fill in-core inodes upon lookup. They don't even
12 * go into icache. We cache the reference to task_struct upon lookup too.
13 * Eventually it should become a filesystem in its own. We don't use the
14 * rest of procfs anymore.
15 *
16 *
17 * Changelog:
18 * 17-Jan-2005
19 * Allan Bezerra
20 * Bruna Moreira <bruna.moreira@indt.org.br>
21 * Edjard Mota <edjard.mota@indt.org.br>
22 * Ilias Biris <ilias.biris@indt.org.br>
23 * Mauricio Lin <mauricio.lin@indt.org.br>
24 *
25 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
26 *
27 * A new process specific entry (smaps) included in /proc. It shows the
28 * size of rss for each memory area. The maps entry lacks information
29 * about physical memory size (rss) for each mapped file, i.e.,
30 * rss information for executables and library files.
31 * This additional information is useful for any tools that need to know
32 * about physical memory consumption for a process specific library.
33 *
34 * Changelog:
35 * 21-Feb-2005
36 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
37 * Pud inclusion in the page table walking.
38 *
39 * ChangeLog:
40 * 10-Mar-2005
41 * 10LE Instituto Nokia de Tecnologia - INdT:
42 * A better way to walks through the page table as suggested by Hugh Dickins.
43 *
44 * Simo Piiroinen <simo.piiroinen@nokia.com>:
45 * Smaps information related to shared, private, clean and dirty pages.
46 *
47 * Paul Mundt <paul.mundt@nokia.com>:
48 * Overall revision about smaps.
49 */
50
51#include <linux/uaccess.h>
52
53#include <linux/errno.h>
54#include <linux/time.h>
55#include <linux/proc_fs.h>
56#include <linux/stat.h>
57#include <linux/task_io_accounting_ops.h>
58#include <linux/init.h>
59#include <linux/capability.h>
60#include <linux/file.h>
61#include <linux/fdtable.h>
62#include <linux/generic-radix-tree.h>
63#include <linux/string.h>
64#include <linux/seq_file.h>
65#include <linux/namei.h>
66#include <linux/mnt_namespace.h>
67#include <linux/mm.h>
68#include <linux/swap.h>
69#include <linux/rcupdate.h>
70#include <linux/stacktrace.h>
71#include <linux/resource.h>
72#include <linux/module.h>
73#include <linux/mount.h>
74#include <linux/security.h>
75#include <linux/ptrace.h>
76#include <linux/tracehook.h>
77#include <linux/printk.h>
78#include <linux/cache.h>
79#include <linux/cgroup.h>
80#include <linux/cpuset.h>
81#include <linux/audit.h>
82#include <linux/poll.h>
83#include <linux/nsproxy.h>
84#include <linux/oom.h>
85#include <linux/elf.h>
86#include <linux/pid_namespace.h>
87#include <linux/user_namespace.h>
88#include <linux/fs_struct.h>
89#include <linux/slab.h>
90#include <linux/sched/autogroup.h>
91#include <linux/sched/mm.h>
92#include <linux/sched/coredump.h>
93#include <linux/sched/debug.h>
94#include <linux/sched/stat.h>
95#include <linux/posix-timers.h>
96#include <linux/time_namespace.h>
97#include <linux/resctrl.h>
98#include <trace/events/oom.h>
99#include "internal.h"
100#include "fd.h"
101
102#include "../../lib/kstrtox.h"
103
104/* NOTE:
105 * Implementing inode permission operations in /proc is almost
106 * certainly an error. Permission checks need to happen during
107 * each system call not at open time. The reason is that most of
108 * what we wish to check for permissions in /proc varies at runtime.
109 *
110 * The classic example of a problem is opening file descriptors
111 * in /proc for a task before it execs a suid executable.
112 */
113
114static u8 nlink_tid __ro_after_init;
115static u8 nlink_tgid __ro_after_init;
116
117struct pid_entry {
118 const char *name;
119 unsigned int len;
120 umode_t mode;
121 const struct inode_operations *iop;
122 const struct file_operations *fop;
123 union proc_op op;
124};
125
126#define NOD(NAME, MODE, IOP, FOP, OP) { \
127 .name = (NAME), \
128 .len = sizeof(NAME) - 1, \
129 .mode = MODE, \
130 .iop = IOP, \
131 .fop = FOP, \
132 .op = OP, \
133}
134
135#define DIR(NAME, MODE, iops, fops) \
136 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
137#define LNK(NAME, get_link) \
138 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
139 &proc_pid_link_inode_operations, NULL, \
140 { .proc_get_link = get_link } )
141#define REG(NAME, MODE, fops) \
142 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
143#define ONE(NAME, MODE, show) \
144 NOD(NAME, (S_IFREG|(MODE)), \
145 NULL, &proc_single_file_operations, \
146 { .proc_show = show } )
147#define ATTR(LSM, NAME, MODE) \
148 NOD(NAME, (S_IFREG|(MODE)), \
149 NULL, &proc_pid_attr_operations, \
150 { .lsm = LSM })
151
152/*
153 * Count the number of hardlinks for the pid_entry table, excluding the .
154 * and .. links.
155 */
156static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
157 unsigned int n)
158{
159 unsigned int i;
160 unsigned int count;
161
162 count = 2;
163 for (i = 0; i < n; ++i) {
164 if (S_ISDIR(entries[i].mode))
165 ++count;
166 }
167
168 return count;
169}
170
171static int get_task_root(struct task_struct *task, struct path *root)
172{
173 int result = -ENOENT;
174
175 task_lock(task);
176 if (task->fs) {
177 get_fs_root(task->fs, root);
178 result = 0;
179 }
180 task_unlock(task);
181 return result;
182}
183
184static int proc_cwd_link(struct dentry *dentry, struct path *path)
185{
186 struct task_struct *task = get_proc_task(d_inode(dentry));
187 int result = -ENOENT;
188
189 if (task) {
190 task_lock(task);
191 if (task->fs) {
192 get_fs_pwd(task->fs, path);
193 result = 0;
194 }
195 task_unlock(task);
196 put_task_struct(task);
197 }
198 return result;
199}
200
201static int proc_root_link(struct dentry *dentry, struct path *path)
202{
203 struct task_struct *task = get_proc_task(d_inode(dentry));
204 int result = -ENOENT;
205
206 if (task) {
207 result = get_task_root(task, path);
208 put_task_struct(task);
209 }
210 return result;
211}
212
213/*
214 * If the user used setproctitle(), we just get the string from
215 * user space at arg_start, and limit it to a maximum of one page.
216 */
217static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf,
218 size_t count, unsigned long pos,
219 unsigned long arg_start)
220{
221 char *page;
222 int ret, got;
223
224 if (pos >= PAGE_SIZE)
225 return 0;
226
227 page = (char *)__get_free_page(GFP_KERNEL);
228 if (!page)
229 return -ENOMEM;
230
231 ret = 0;
232 got = access_remote_vm(mm, arg_start, page, PAGE_SIZE, FOLL_ANON);
233 if (got > 0) {
234 int len = strnlen(page, got);
235
236 /* Include the NUL character if it was found */
237 if (len < got)
238 len++;
239
240 if (len > pos) {
241 len -= pos;
242 if (len > count)
243 len = count;
244 len -= copy_to_user(buf, page+pos, len);
245 if (!len)
246 len = -EFAULT;
247 ret = len;
248 }
249 }
250 free_page((unsigned long)page);
251 return ret;
252}
253
254static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
255 size_t count, loff_t *ppos)
256{
257 unsigned long arg_start, arg_end, env_start, env_end;
258 unsigned long pos, len;
259 char *page, c;
260
261 /* Check if process spawned far enough to have cmdline. */
262 if (!mm->env_end)
263 return 0;
264
265 spin_lock(&mm->arg_lock);
266 arg_start = mm->arg_start;
267 arg_end = mm->arg_end;
268 env_start = mm->env_start;
269 env_end = mm->env_end;
270 spin_unlock(&mm->arg_lock);
271
272 if (arg_start >= arg_end)
273 return 0;
274
275 /*
276 * We allow setproctitle() to overwrite the argument
277 * strings, and overflow past the original end. But
278 * only when it overflows into the environment area.
279 */
280 if (env_start != arg_end || env_end < env_start)
281 env_start = env_end = arg_end;
282 len = env_end - arg_start;
283
284 /* We're not going to care if "*ppos" has high bits set */
285 pos = *ppos;
286 if (pos >= len)
287 return 0;
288 if (count > len - pos)
289 count = len - pos;
290 if (!count)
291 return 0;
292
293 /*
294 * Magical special case: if the argv[] end byte is not
295 * zero, the user has overwritten it with setproctitle(3).
296 *
297 * Possible future enhancement: do this only once when
298 * pos is 0, and set a flag in the 'struct file'.
299 */
300 if (access_remote_vm(mm, arg_end-1, &c, 1, FOLL_ANON) == 1 && c)
301 return get_mm_proctitle(mm, buf, count, pos, arg_start);
302
303 /*
304 * For the non-setproctitle() case we limit things strictly
305 * to the [arg_start, arg_end[ range.
306 */
307 pos += arg_start;
308 if (pos < arg_start || pos >= arg_end)
309 return 0;
310 if (count > arg_end - pos)
311 count = arg_end - pos;
312
313 page = (char *)__get_free_page(GFP_KERNEL);
314 if (!page)
315 return -ENOMEM;
316
317 len = 0;
318 while (count) {
319 int got;
320 size_t size = min_t(size_t, PAGE_SIZE, count);
321
322 got = access_remote_vm(mm, pos, page, size, FOLL_ANON);
323 if (got <= 0)
324 break;
325 got -= copy_to_user(buf, page, got);
326 if (unlikely(!got)) {
327 if (!len)
328 len = -EFAULT;
329 break;
330 }
331 pos += got;
332 buf += got;
333 len += got;
334 count -= got;
335 }
336
337 free_page((unsigned long)page);
338 return len;
339}
340
341static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf,
342 size_t count, loff_t *pos)
343{
344 struct mm_struct *mm;
345 ssize_t ret;
346
347 mm = get_task_mm(tsk);
348 if (!mm)
349 return 0;
350
351 ret = get_mm_cmdline(mm, buf, count, pos);
352 mmput(mm);
353 return ret;
354}
355
356static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
357 size_t count, loff_t *pos)
358{
359 struct task_struct *tsk;
360 ssize_t ret;
361
362 BUG_ON(*pos < 0);
363
364 tsk = get_proc_task(file_inode(file));
365 if (!tsk)
366 return -ESRCH;
367 ret = get_task_cmdline(tsk, buf, count, pos);
368 put_task_struct(tsk);
369 if (ret > 0)
370 *pos += ret;
371 return ret;
372}
373
374static const struct file_operations proc_pid_cmdline_ops = {
375 .read = proc_pid_cmdline_read,
376 .llseek = generic_file_llseek,
377};
378
379#ifdef CONFIG_KALLSYMS
380/*
381 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
382 * Returns the resolved symbol. If that fails, simply return the address.
383 */
384static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
385 struct pid *pid, struct task_struct *task)
386{
387 unsigned long wchan;
388
389 if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
390 wchan = get_wchan(task);
391 else
392 wchan = 0;
393
394 if (wchan)
395 seq_printf(m, "%ps", (void *) wchan);
396 else
397 seq_putc(m, '0');
398
399 return 0;
400}
401#endif /* CONFIG_KALLSYMS */
402
403static int lock_trace(struct task_struct *task)
404{
405 int err = down_read_killable(&task->signal->exec_update_lock);
406 if (err)
407 return err;
408 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
409 up_read(&task->signal->exec_update_lock);
410 return -EPERM;
411 }
412 return 0;
413}
414
415static void unlock_trace(struct task_struct *task)
416{
417 up_read(&task->signal->exec_update_lock);
418}
419
420#ifdef CONFIG_STACKTRACE
421
422#define MAX_STACK_TRACE_DEPTH 64
423
424static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
425 struct pid *pid, struct task_struct *task)
426{
427 unsigned long *entries;
428 int err;
429
430 /*
431 * The ability to racily run the kernel stack unwinder on a running task
432 * and then observe the unwinder output is scary; while it is useful for
433 * debugging kernel issues, it can also allow an attacker to leak kernel
434 * stack contents.
435 * Doing this in a manner that is at least safe from races would require
436 * some work to ensure that the remote task can not be scheduled; and
437 * even then, this would still expose the unwinder as local attack
438 * surface.
439 * Therefore, this interface is restricted to root.
440 */
441 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
442 return -EACCES;
443
444 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
445 GFP_KERNEL);
446 if (!entries)
447 return -ENOMEM;
448
449 err = lock_trace(task);
450 if (!err) {
451 unsigned int i, nr_entries;
452
453 nr_entries = stack_trace_save_tsk(task, entries,
454 MAX_STACK_TRACE_DEPTH, 0);
455
456 for (i = 0; i < nr_entries; i++) {
457 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
458 }
459
460 unlock_trace(task);
461 }
462 kfree(entries);
463
464 return err;
465}
466#endif
467
468#ifdef CONFIG_SCHED_INFO
469/*
470 * Provides /proc/PID/schedstat
471 */
472static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
473 struct pid *pid, struct task_struct *task)
474{
475 if (unlikely(!sched_info_on()))
476 seq_puts(m, "0 0 0\n");
477 else
478 seq_printf(m, "%llu %llu %lu\n",
479 (unsigned long long)task->se.sum_exec_runtime,
480 (unsigned long long)task->sched_info.run_delay,
481 task->sched_info.pcount);
482
483 return 0;
484}
485#endif
486
487#ifdef CONFIG_LATENCYTOP
488static int lstats_show_proc(struct seq_file *m, void *v)
489{
490 int i;
491 struct inode *inode = m->private;
492 struct task_struct *task = get_proc_task(inode);
493
494 if (!task)
495 return -ESRCH;
496 seq_puts(m, "Latency Top version : v0.1\n");
497 for (i = 0; i < LT_SAVECOUNT; i++) {
498 struct latency_record *lr = &task->latency_record[i];
499 if (lr->backtrace[0]) {
500 int q;
501 seq_printf(m, "%i %li %li",
502 lr->count, lr->time, lr->max);
503 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
504 unsigned long bt = lr->backtrace[q];
505
506 if (!bt)
507 break;
508 seq_printf(m, " %ps", (void *)bt);
509 }
510 seq_putc(m, '\n');
511 }
512
513 }
514 put_task_struct(task);
515 return 0;
516}
517
518static int lstats_open(struct inode *inode, struct file *file)
519{
520 return single_open(file, lstats_show_proc, inode);
521}
522
523static ssize_t lstats_write(struct file *file, const char __user *buf,
524 size_t count, loff_t *offs)
525{
526 struct task_struct *task = get_proc_task(file_inode(file));
527
528 if (!task)
529 return -ESRCH;
530 clear_tsk_latency_tracing(task);
531 put_task_struct(task);
532
533 return count;
534}
535
536static const struct file_operations proc_lstats_operations = {
537 .open = lstats_open,
538 .read = seq_read,
539 .write = lstats_write,
540 .llseek = seq_lseek,
541 .release = single_release,
542};
543
544#endif
545
546static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
547 struct pid *pid, struct task_struct *task)
548{
549 unsigned long totalpages = totalram_pages() + total_swap_pages;
550 unsigned long points = 0;
551 long badness;
552
553 badness = oom_badness(task, totalpages);
554 /*
555 * Special case OOM_SCORE_ADJ_MIN for all others scale the
556 * badness value into [0, 2000] range which we have been
557 * exporting for a long time so userspace might depend on it.
558 */
559 if (badness != LONG_MIN)
560 points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3;
561
562 seq_printf(m, "%lu\n", points);
563
564 return 0;
565}
566
567struct limit_names {
568 const char *name;
569 const char *unit;
570};
571
572static const struct limit_names lnames[RLIM_NLIMITS] = {
573 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
574 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
575 [RLIMIT_DATA] = {"Max data size", "bytes"},
576 [RLIMIT_STACK] = {"Max stack size", "bytes"},
577 [RLIMIT_CORE] = {"Max core file size", "bytes"},
578 [RLIMIT_RSS] = {"Max resident set", "bytes"},
579 [RLIMIT_NPROC] = {"Max processes", "processes"},
580 [RLIMIT_NOFILE] = {"Max open files", "files"},
581 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
582 [RLIMIT_AS] = {"Max address space", "bytes"},
583 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
584 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
585 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
586 [RLIMIT_NICE] = {"Max nice priority", NULL},
587 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
588 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
589};
590
591/* Display limits for a process */
592static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
593 struct pid *pid, struct task_struct *task)
594{
595 unsigned int i;
596 unsigned long flags;
597
598 struct rlimit rlim[RLIM_NLIMITS];
599
600 if (!lock_task_sighand(task, &flags))
601 return 0;
602 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
603 unlock_task_sighand(task, &flags);
604
605 /*
606 * print the file header
607 */
608 seq_puts(m, "Limit "
609 "Soft Limit "
610 "Hard Limit "
611 "Units \n");
612
613 for (i = 0; i < RLIM_NLIMITS; i++) {
614 if (rlim[i].rlim_cur == RLIM_INFINITY)
615 seq_printf(m, "%-25s %-20s ",
616 lnames[i].name, "unlimited");
617 else
618 seq_printf(m, "%-25s %-20lu ",
619 lnames[i].name, rlim[i].rlim_cur);
620
621 if (rlim[i].rlim_max == RLIM_INFINITY)
622 seq_printf(m, "%-20s ", "unlimited");
623 else
624 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
625
626 if (lnames[i].unit)
627 seq_printf(m, "%-10s\n", lnames[i].unit);
628 else
629 seq_putc(m, '\n');
630 }
631
632 return 0;
633}
634
635#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
636static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
637 struct pid *pid, struct task_struct *task)
638{
639 struct syscall_info info;
640 u64 *args = &info.data.args[0];
641 int res;
642
643 res = lock_trace(task);
644 if (res)
645 return res;
646
647 if (task_current_syscall(task, &info))
648 seq_puts(m, "running\n");
649 else if (info.data.nr < 0)
650 seq_printf(m, "%d 0x%llx 0x%llx\n",
651 info.data.nr, info.sp, info.data.instruction_pointer);
652 else
653 seq_printf(m,
654 "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
655 info.data.nr,
656 args[0], args[1], args[2], args[3], args[4], args[5],
657 info.sp, info.data.instruction_pointer);
658 unlock_trace(task);
659
660 return 0;
661}
662#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
663
664/************************************************************************/
665/* Here the fs part begins */
666/************************************************************************/
667
668/* permission checks */
669static int proc_fd_access_allowed(struct inode *inode)
670{
671 struct task_struct *task;
672 int allowed = 0;
673 /* Allow access to a task's file descriptors if it is us or we
674 * may use ptrace attach to the process and find out that
675 * information.
676 */
677 task = get_proc_task(inode);
678 if (task) {
679 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
680 put_task_struct(task);
681 }
682 return allowed;
683}
684
685int proc_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
686 struct iattr *attr)
687{
688 int error;
689 struct inode *inode = d_inode(dentry);
690
691 if (attr->ia_valid & ATTR_MODE)
692 return -EPERM;
693
694 error = setattr_prepare(&init_user_ns, dentry, attr);
695 if (error)
696 return error;
697
698 setattr_copy(&init_user_ns, inode, attr);
699 mark_inode_dirty(inode);
700 return 0;
701}
702
703/*
704 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
705 * or euid/egid (for hide_pid_min=2)?
706 */
707static bool has_pid_permissions(struct proc_fs_info *fs_info,
708 struct task_struct *task,
709 enum proc_hidepid hide_pid_min)
710{
711 /*
712 * If 'hidpid' mount option is set force a ptrace check,
713 * we indicate that we are using a filesystem syscall
714 * by passing PTRACE_MODE_READ_FSCREDS
715 */
716 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE)
717 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
718
719 if (fs_info->hide_pid < hide_pid_min)
720 return true;
721 if (in_group_p(fs_info->pid_gid))
722 return true;
723 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
724}
725
726
727static int proc_pid_permission(struct user_namespace *mnt_userns,
728 struct inode *inode, int mask)
729{
730 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
731 struct task_struct *task;
732 bool has_perms;
733
734 task = get_proc_task(inode);
735 if (!task)
736 return -ESRCH;
737 has_perms = has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS);
738 put_task_struct(task);
739
740 if (!has_perms) {
741 if (fs_info->hide_pid == HIDEPID_INVISIBLE) {
742 /*
743 * Let's make getdents(), stat(), and open()
744 * consistent with each other. If a process
745 * may not stat() a file, it shouldn't be seen
746 * in procfs at all.
747 */
748 return -ENOENT;
749 }
750
751 return -EPERM;
752 }
753 return generic_permission(&init_user_ns, inode, mask);
754}
755
756
757
758static const struct inode_operations proc_def_inode_operations = {
759 .setattr = proc_setattr,
760};
761
762static int proc_single_show(struct seq_file *m, void *v)
763{
764 struct inode *inode = m->private;
765 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
766 struct pid *pid = proc_pid(inode);
767 struct task_struct *task;
768 int ret;
769
770 task = get_pid_task(pid, PIDTYPE_PID);
771 if (!task)
772 return -ESRCH;
773
774 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
775
776 put_task_struct(task);
777 return ret;
778}
779
780static int proc_single_open(struct inode *inode, struct file *filp)
781{
782 return single_open(filp, proc_single_show, inode);
783}
784
785static const struct file_operations proc_single_file_operations = {
786 .open = proc_single_open,
787 .read = seq_read,
788 .llseek = seq_lseek,
789 .release = single_release,
790};
791
792
793struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
794{
795 struct task_struct *task = get_proc_task(inode);
796 struct mm_struct *mm = ERR_PTR(-ESRCH);
797
798 if (task) {
799 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
800 put_task_struct(task);
801
802 if (!IS_ERR_OR_NULL(mm)) {
803 /* ensure this mm_struct can't be freed */
804 mmgrab(mm);
805 /* but do not pin its memory */
806 mmput(mm);
807 }
808 }
809
810 return mm;
811}
812
813static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
814{
815 struct mm_struct *mm = proc_mem_open(inode, mode);
816
817 if (IS_ERR(mm))
818 return PTR_ERR(mm);
819
820 file->private_data = mm;
821 return 0;
822}
823
824static int mem_open(struct inode *inode, struct file *file)
825{
826 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
827
828 /* OK to pass negative loff_t, we can catch out-of-range */
829 file->f_mode |= FMODE_UNSIGNED_OFFSET;
830
831 return ret;
832}
833
834static ssize_t mem_rw(struct file *file, char __user *buf,
835 size_t count, loff_t *ppos, int write)
836{
837 struct mm_struct *mm = file->private_data;
838 unsigned long addr = *ppos;
839 ssize_t copied;
840 char *page;
841 unsigned int flags;
842
843 if (!mm)
844 return 0;
845
846 page = (char *)__get_free_page(GFP_KERNEL);
847 if (!page)
848 return -ENOMEM;
849
850 copied = 0;
851 if (!mmget_not_zero(mm))
852 goto free;
853
854 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
855
856 while (count > 0) {
857 size_t this_len = min_t(size_t, count, PAGE_SIZE);
858
859 if (write && copy_from_user(page, buf, this_len)) {
860 copied = -EFAULT;
861 break;
862 }
863
864 this_len = access_remote_vm(mm, addr, page, this_len, flags);
865 if (!this_len) {
866 if (!copied)
867 copied = -EIO;
868 break;
869 }
870
871 if (!write && copy_to_user(buf, page, this_len)) {
872 copied = -EFAULT;
873 break;
874 }
875
876 buf += this_len;
877 addr += this_len;
878 copied += this_len;
879 count -= this_len;
880 }
881 *ppos = addr;
882
883 mmput(mm);
884free:
885 free_page((unsigned long) page);
886 return copied;
887}
888
889static ssize_t mem_read(struct file *file, char __user *buf,
890 size_t count, loff_t *ppos)
891{
892 return mem_rw(file, buf, count, ppos, 0);
893}
894
895static ssize_t mem_write(struct file *file, const char __user *buf,
896 size_t count, loff_t *ppos)
897{
898 return mem_rw(file, (char __user*)buf, count, ppos, 1);
899}
900
901loff_t mem_lseek(struct file *file, loff_t offset, int orig)
902{
903 switch (orig) {
904 case 0:
905 file->f_pos = offset;
906 break;
907 case 1:
908 file->f_pos += offset;
909 break;
910 default:
911 return -EINVAL;
912 }
913 force_successful_syscall_return();
914 return file->f_pos;
915}
916
917static int mem_release(struct inode *inode, struct file *file)
918{
919 struct mm_struct *mm = file->private_data;
920 if (mm)
921 mmdrop(mm);
922 return 0;
923}
924
925static const struct file_operations proc_mem_operations = {
926 .llseek = mem_lseek,
927 .read = mem_read,
928 .write = mem_write,
929 .open = mem_open,
930 .release = mem_release,
931};
932
933static int environ_open(struct inode *inode, struct file *file)
934{
935 return __mem_open(inode, file, PTRACE_MODE_READ);
936}
937
938static ssize_t environ_read(struct file *file, char __user *buf,
939 size_t count, loff_t *ppos)
940{
941 char *page;
942 unsigned long src = *ppos;
943 int ret = 0;
944 struct mm_struct *mm = file->private_data;
945 unsigned long env_start, env_end;
946
947 /* Ensure the process spawned far enough to have an environment. */
948 if (!mm || !mm->env_end)
949 return 0;
950
951 page = (char *)__get_free_page(GFP_KERNEL);
952 if (!page)
953 return -ENOMEM;
954
955 ret = 0;
956 if (!mmget_not_zero(mm))
957 goto free;
958
959 spin_lock(&mm->arg_lock);
960 env_start = mm->env_start;
961 env_end = mm->env_end;
962 spin_unlock(&mm->arg_lock);
963
964 while (count > 0) {
965 size_t this_len, max_len;
966 int retval;
967
968 if (src >= (env_end - env_start))
969 break;
970
971 this_len = env_end - (env_start + src);
972
973 max_len = min_t(size_t, PAGE_SIZE, count);
974 this_len = min(max_len, this_len);
975
976 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
977
978 if (retval <= 0) {
979 ret = retval;
980 break;
981 }
982
983 if (copy_to_user(buf, page, retval)) {
984 ret = -EFAULT;
985 break;
986 }
987
988 ret += retval;
989 src += retval;
990 buf += retval;
991 count -= retval;
992 }
993 *ppos = src;
994 mmput(mm);
995
996free:
997 free_page((unsigned long) page);
998 return ret;
999}
1000
1001static const struct file_operations proc_environ_operations = {
1002 .open = environ_open,
1003 .read = environ_read,
1004 .llseek = generic_file_llseek,
1005 .release = mem_release,
1006};
1007
1008static int auxv_open(struct inode *inode, struct file *file)
1009{
1010 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1011}
1012
1013static ssize_t auxv_read(struct file *file, char __user *buf,
1014 size_t count, loff_t *ppos)
1015{
1016 struct mm_struct *mm = file->private_data;
1017 unsigned int nwords = 0;
1018
1019 if (!mm)
1020 return 0;
1021 do {
1022 nwords += 2;
1023 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1024 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1025 nwords * sizeof(mm->saved_auxv[0]));
1026}
1027
1028static const struct file_operations proc_auxv_operations = {
1029 .open = auxv_open,
1030 .read = auxv_read,
1031 .llseek = generic_file_llseek,
1032 .release = mem_release,
1033};
1034
1035static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1036 loff_t *ppos)
1037{
1038 struct task_struct *task = get_proc_task(file_inode(file));
1039 char buffer[PROC_NUMBUF];
1040 int oom_adj = OOM_ADJUST_MIN;
1041 size_t len;
1042
1043 if (!task)
1044 return -ESRCH;
1045 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1046 oom_adj = OOM_ADJUST_MAX;
1047 else
1048 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1049 OOM_SCORE_ADJ_MAX;
1050 put_task_struct(task);
1051 if (oom_adj > OOM_ADJUST_MAX)
1052 oom_adj = OOM_ADJUST_MAX;
1053 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1054 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1055}
1056
1057static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1058{
1059 struct mm_struct *mm = NULL;
1060 struct task_struct *task;
1061 int err = 0;
1062
1063 task = get_proc_task(file_inode(file));
1064 if (!task)
1065 return -ESRCH;
1066
1067 mutex_lock(&oom_adj_mutex);
1068 if (legacy) {
1069 if (oom_adj < task->signal->oom_score_adj &&
1070 !capable(CAP_SYS_RESOURCE)) {
1071 err = -EACCES;
1072 goto err_unlock;
1073 }
1074 /*
1075 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1076 * /proc/pid/oom_score_adj instead.
1077 */
1078 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1079 current->comm, task_pid_nr(current), task_pid_nr(task),
1080 task_pid_nr(task));
1081 } else {
1082 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1083 !capable(CAP_SYS_RESOURCE)) {
1084 err = -EACCES;
1085 goto err_unlock;
1086 }
1087 }
1088
1089 /*
1090 * Make sure we will check other processes sharing the mm if this is
1091 * not vfrok which wants its own oom_score_adj.
1092 * pin the mm so it doesn't go away and get reused after task_unlock
1093 */
1094 if (!task->vfork_done) {
1095 struct task_struct *p = find_lock_task_mm(task);
1096
1097 if (p) {
1098 if (test_bit(MMF_MULTIPROCESS, &p->mm->flags)) {
1099 mm = p->mm;
1100 mmgrab(mm);
1101 }
1102 task_unlock(p);
1103 }
1104 }
1105
1106 task->signal->oom_score_adj = oom_adj;
1107 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1108 task->signal->oom_score_adj_min = (short)oom_adj;
1109 trace_oom_score_adj_update(task);
1110
1111 if (mm) {
1112 struct task_struct *p;
1113
1114 rcu_read_lock();
1115 for_each_process(p) {
1116 if (same_thread_group(task, p))
1117 continue;
1118
1119 /* do not touch kernel threads or the global init */
1120 if (p->flags & PF_KTHREAD || is_global_init(p))
1121 continue;
1122
1123 task_lock(p);
1124 if (!p->vfork_done && process_shares_mm(p, mm)) {
1125 p->signal->oom_score_adj = oom_adj;
1126 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1127 p->signal->oom_score_adj_min = (short)oom_adj;
1128 }
1129 task_unlock(p);
1130 }
1131 rcu_read_unlock();
1132 mmdrop(mm);
1133 }
1134err_unlock:
1135 mutex_unlock(&oom_adj_mutex);
1136 put_task_struct(task);
1137 return err;
1138}
1139
1140/*
1141 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1142 * kernels. The effective policy is defined by oom_score_adj, which has a
1143 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1144 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1145 * Processes that become oom disabled via oom_adj will still be oom disabled
1146 * with this implementation.
1147 *
1148 * oom_adj cannot be removed since existing userspace binaries use it.
1149 */
1150static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1151 size_t count, loff_t *ppos)
1152{
1153 char buffer[PROC_NUMBUF];
1154 int oom_adj;
1155 int err;
1156
1157 memset(buffer, 0, sizeof(buffer));
1158 if (count > sizeof(buffer) - 1)
1159 count = sizeof(buffer) - 1;
1160 if (copy_from_user(buffer, buf, count)) {
1161 err = -EFAULT;
1162 goto out;
1163 }
1164
1165 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1166 if (err)
1167 goto out;
1168 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1169 oom_adj != OOM_DISABLE) {
1170 err = -EINVAL;
1171 goto out;
1172 }
1173
1174 /*
1175 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1176 * value is always attainable.
1177 */
1178 if (oom_adj == OOM_ADJUST_MAX)
1179 oom_adj = OOM_SCORE_ADJ_MAX;
1180 else
1181 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1182
1183 err = __set_oom_adj(file, oom_adj, true);
1184out:
1185 return err < 0 ? err : count;
1186}
1187
1188static const struct file_operations proc_oom_adj_operations = {
1189 .read = oom_adj_read,
1190 .write = oom_adj_write,
1191 .llseek = generic_file_llseek,
1192};
1193
1194static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1195 size_t count, loff_t *ppos)
1196{
1197 struct task_struct *task = get_proc_task(file_inode(file));
1198 char buffer[PROC_NUMBUF];
1199 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1200 size_t len;
1201
1202 if (!task)
1203 return -ESRCH;
1204 oom_score_adj = task->signal->oom_score_adj;
1205 put_task_struct(task);
1206 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1207 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1208}
1209
1210static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1211 size_t count, loff_t *ppos)
1212{
1213 char buffer[PROC_NUMBUF];
1214 int oom_score_adj;
1215 int err;
1216
1217 memset(buffer, 0, sizeof(buffer));
1218 if (count > sizeof(buffer) - 1)
1219 count = sizeof(buffer) - 1;
1220 if (copy_from_user(buffer, buf, count)) {
1221 err = -EFAULT;
1222 goto out;
1223 }
1224
1225 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1226 if (err)
1227 goto out;
1228 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1229 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1230 err = -EINVAL;
1231 goto out;
1232 }
1233
1234 err = __set_oom_adj(file, oom_score_adj, false);
1235out:
1236 return err < 0 ? err : count;
1237}
1238
1239static const struct file_operations proc_oom_score_adj_operations = {
1240 .read = oom_score_adj_read,
1241 .write = oom_score_adj_write,
1242 .llseek = default_llseek,
1243};
1244
1245#ifdef CONFIG_AUDIT
1246#define TMPBUFLEN 11
1247static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1248 size_t count, loff_t *ppos)
1249{
1250 struct inode * inode = file_inode(file);
1251 struct task_struct *task = get_proc_task(inode);
1252 ssize_t length;
1253 char tmpbuf[TMPBUFLEN];
1254
1255 if (!task)
1256 return -ESRCH;
1257 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1258 from_kuid(file->f_cred->user_ns,
1259 audit_get_loginuid(task)));
1260 put_task_struct(task);
1261 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1262}
1263
1264static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1265 size_t count, loff_t *ppos)
1266{
1267 struct inode * inode = file_inode(file);
1268 uid_t loginuid;
1269 kuid_t kloginuid;
1270 int rv;
1271
1272 /* Don't let kthreads write their own loginuid */
1273 if (current->flags & PF_KTHREAD)
1274 return -EPERM;
1275
1276 rcu_read_lock();
1277 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1278 rcu_read_unlock();
1279 return -EPERM;
1280 }
1281 rcu_read_unlock();
1282
1283 if (*ppos != 0) {
1284 /* No partial writes. */
1285 return -EINVAL;
1286 }
1287
1288 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1289 if (rv < 0)
1290 return rv;
1291
1292 /* is userspace tring to explicitly UNSET the loginuid? */
1293 if (loginuid == AUDIT_UID_UNSET) {
1294 kloginuid = INVALID_UID;
1295 } else {
1296 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1297 if (!uid_valid(kloginuid))
1298 return -EINVAL;
1299 }
1300
1301 rv = audit_set_loginuid(kloginuid);
1302 if (rv < 0)
1303 return rv;
1304 return count;
1305}
1306
1307static const struct file_operations proc_loginuid_operations = {
1308 .read = proc_loginuid_read,
1309 .write = proc_loginuid_write,
1310 .llseek = generic_file_llseek,
1311};
1312
1313static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1314 size_t count, loff_t *ppos)
1315{
1316 struct inode * inode = file_inode(file);
1317 struct task_struct *task = get_proc_task(inode);
1318 ssize_t length;
1319 char tmpbuf[TMPBUFLEN];
1320
1321 if (!task)
1322 return -ESRCH;
1323 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1324 audit_get_sessionid(task));
1325 put_task_struct(task);
1326 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1327}
1328
1329static const struct file_operations proc_sessionid_operations = {
1330 .read = proc_sessionid_read,
1331 .llseek = generic_file_llseek,
1332};
1333#endif
1334
1335#ifdef CONFIG_FAULT_INJECTION
1336static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1337 size_t count, loff_t *ppos)
1338{
1339 struct task_struct *task = get_proc_task(file_inode(file));
1340 char buffer[PROC_NUMBUF];
1341 size_t len;
1342 int make_it_fail;
1343
1344 if (!task)
1345 return -ESRCH;
1346 make_it_fail = task->make_it_fail;
1347 put_task_struct(task);
1348
1349 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1350
1351 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1352}
1353
1354static ssize_t proc_fault_inject_write(struct file * file,
1355 const char __user * buf, size_t count, loff_t *ppos)
1356{
1357 struct task_struct *task;
1358 char buffer[PROC_NUMBUF];
1359 int make_it_fail;
1360 int rv;
1361
1362 if (!capable(CAP_SYS_RESOURCE))
1363 return -EPERM;
1364 memset(buffer, 0, sizeof(buffer));
1365 if (count > sizeof(buffer) - 1)
1366 count = sizeof(buffer) - 1;
1367 if (copy_from_user(buffer, buf, count))
1368 return -EFAULT;
1369 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1370 if (rv < 0)
1371 return rv;
1372 if (make_it_fail < 0 || make_it_fail > 1)
1373 return -EINVAL;
1374
1375 task = get_proc_task(file_inode(file));
1376 if (!task)
1377 return -ESRCH;
1378 task->make_it_fail = make_it_fail;
1379 put_task_struct(task);
1380
1381 return count;
1382}
1383
1384static const struct file_operations proc_fault_inject_operations = {
1385 .read = proc_fault_inject_read,
1386 .write = proc_fault_inject_write,
1387 .llseek = generic_file_llseek,
1388};
1389
1390static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1391 size_t count, loff_t *ppos)
1392{
1393 struct task_struct *task;
1394 int err;
1395 unsigned int n;
1396
1397 err = kstrtouint_from_user(buf, count, 0, &n);
1398 if (err)
1399 return err;
1400
1401 task = get_proc_task(file_inode(file));
1402 if (!task)
1403 return -ESRCH;
1404 task->fail_nth = n;
1405 put_task_struct(task);
1406
1407 return count;
1408}
1409
1410static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1411 size_t count, loff_t *ppos)
1412{
1413 struct task_struct *task;
1414 char numbuf[PROC_NUMBUF];
1415 ssize_t len;
1416
1417 task = get_proc_task(file_inode(file));
1418 if (!task)
1419 return -ESRCH;
1420 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1421 put_task_struct(task);
1422 return simple_read_from_buffer(buf, count, ppos, numbuf, len);
1423}
1424
1425static const struct file_operations proc_fail_nth_operations = {
1426 .read = proc_fail_nth_read,
1427 .write = proc_fail_nth_write,
1428};
1429#endif
1430
1431
1432#ifdef CONFIG_SCHED_DEBUG
1433/*
1434 * Print out various scheduling related per-task fields:
1435 */
1436static int sched_show(struct seq_file *m, void *v)
1437{
1438 struct inode *inode = m->private;
1439 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
1440 struct task_struct *p;
1441
1442 p = get_proc_task(inode);
1443 if (!p)
1444 return -ESRCH;
1445 proc_sched_show_task(p, ns, m);
1446
1447 put_task_struct(p);
1448
1449 return 0;
1450}
1451
1452static ssize_t
1453sched_write(struct file *file, const char __user *buf,
1454 size_t count, loff_t *offset)
1455{
1456 struct inode *inode = file_inode(file);
1457 struct task_struct *p;
1458
1459 p = get_proc_task(inode);
1460 if (!p)
1461 return -ESRCH;
1462 proc_sched_set_task(p);
1463
1464 put_task_struct(p);
1465
1466 return count;
1467}
1468
1469static int sched_open(struct inode *inode, struct file *filp)
1470{
1471 return single_open(filp, sched_show, inode);
1472}
1473
1474static const struct file_operations proc_pid_sched_operations = {
1475 .open = sched_open,
1476 .read = seq_read,
1477 .write = sched_write,
1478 .llseek = seq_lseek,
1479 .release = single_release,
1480};
1481
1482#endif
1483
1484#ifdef CONFIG_SCHED_AUTOGROUP
1485/*
1486 * Print out autogroup related information:
1487 */
1488static int sched_autogroup_show(struct seq_file *m, void *v)
1489{
1490 struct inode *inode = m->private;
1491 struct task_struct *p;
1492
1493 p = get_proc_task(inode);
1494 if (!p)
1495 return -ESRCH;
1496 proc_sched_autogroup_show_task(p, m);
1497
1498 put_task_struct(p);
1499
1500 return 0;
1501}
1502
1503static ssize_t
1504sched_autogroup_write(struct file *file, const char __user *buf,
1505 size_t count, loff_t *offset)
1506{
1507 struct inode *inode = file_inode(file);
1508 struct task_struct *p;
1509 char buffer[PROC_NUMBUF];
1510 int nice;
1511 int err;
1512
1513 memset(buffer, 0, sizeof(buffer));
1514 if (count > sizeof(buffer) - 1)
1515 count = sizeof(buffer) - 1;
1516 if (copy_from_user(buffer, buf, count))
1517 return -EFAULT;
1518
1519 err = kstrtoint(strstrip(buffer), 0, &nice);
1520 if (err < 0)
1521 return err;
1522
1523 p = get_proc_task(inode);
1524 if (!p)
1525 return -ESRCH;
1526
1527 err = proc_sched_autogroup_set_nice(p, nice);
1528 if (err)
1529 count = err;
1530
1531 put_task_struct(p);
1532
1533 return count;
1534}
1535
1536static int sched_autogroup_open(struct inode *inode, struct file *filp)
1537{
1538 int ret;
1539
1540 ret = single_open(filp, sched_autogroup_show, NULL);
1541 if (!ret) {
1542 struct seq_file *m = filp->private_data;
1543
1544 m->private = inode;
1545 }
1546 return ret;
1547}
1548
1549static const struct file_operations proc_pid_sched_autogroup_operations = {
1550 .open = sched_autogroup_open,
1551 .read = seq_read,
1552 .write = sched_autogroup_write,
1553 .llseek = seq_lseek,
1554 .release = single_release,
1555};
1556
1557#endif /* CONFIG_SCHED_AUTOGROUP */
1558
1559#ifdef CONFIG_TIME_NS
1560static int timens_offsets_show(struct seq_file *m, void *v)
1561{
1562 struct task_struct *p;
1563
1564 p = get_proc_task(file_inode(m->file));
1565 if (!p)
1566 return -ESRCH;
1567 proc_timens_show_offsets(p, m);
1568
1569 put_task_struct(p);
1570
1571 return 0;
1572}
1573
1574static ssize_t timens_offsets_write(struct file *file, const char __user *buf,
1575 size_t count, loff_t *ppos)
1576{
1577 struct inode *inode = file_inode(file);
1578 struct proc_timens_offset offsets[2];
1579 char *kbuf = NULL, *pos, *next_line;
1580 struct task_struct *p;
1581 int ret, noffsets;
1582
1583 /* Only allow < page size writes at the beginning of the file */
1584 if ((*ppos != 0) || (count >= PAGE_SIZE))
1585 return -EINVAL;
1586
1587 /* Slurp in the user data */
1588 kbuf = memdup_user_nul(buf, count);
1589 if (IS_ERR(kbuf))
1590 return PTR_ERR(kbuf);
1591
1592 /* Parse the user data */
1593 ret = -EINVAL;
1594 noffsets = 0;
1595 for (pos = kbuf; pos; pos = next_line) {
1596 struct proc_timens_offset *off = &offsets[noffsets];
1597 char clock[10];
1598 int err;
1599
1600 /* Find the end of line and ensure we don't look past it */
1601 next_line = strchr(pos, '\n');
1602 if (next_line) {
1603 *next_line = '\0';
1604 next_line++;
1605 if (*next_line == '\0')
1606 next_line = NULL;
1607 }
1608
1609 err = sscanf(pos, "%9s %lld %lu", clock,
1610 &off->val.tv_sec, &off->val.tv_nsec);
1611 if (err != 3 || off->val.tv_nsec >= NSEC_PER_SEC)
1612 goto out;
1613
1614 clock[sizeof(clock) - 1] = 0;
1615 if (strcmp(clock, "monotonic") == 0 ||
1616 strcmp(clock, __stringify(CLOCK_MONOTONIC)) == 0)
1617 off->clockid = CLOCK_MONOTONIC;
1618 else if (strcmp(clock, "boottime") == 0 ||
1619 strcmp(clock, __stringify(CLOCK_BOOTTIME)) == 0)
1620 off->clockid = CLOCK_BOOTTIME;
1621 else
1622 goto out;
1623
1624 noffsets++;
1625 if (noffsets == ARRAY_SIZE(offsets)) {
1626 if (next_line)
1627 count = next_line - kbuf;
1628 break;
1629 }
1630 }
1631
1632 ret = -ESRCH;
1633 p = get_proc_task(inode);
1634 if (!p)
1635 goto out;
1636 ret = proc_timens_set_offset(file, p, offsets, noffsets);
1637 put_task_struct(p);
1638 if (ret)
1639 goto out;
1640
1641 ret = count;
1642out:
1643 kfree(kbuf);
1644 return ret;
1645}
1646
1647static int timens_offsets_open(struct inode *inode, struct file *filp)
1648{
1649 return single_open(filp, timens_offsets_show, inode);
1650}
1651
1652static const struct file_operations proc_timens_offsets_operations = {
1653 .open = timens_offsets_open,
1654 .read = seq_read,
1655 .write = timens_offsets_write,
1656 .llseek = seq_lseek,
1657 .release = single_release,
1658};
1659#endif /* CONFIG_TIME_NS */
1660
1661static ssize_t comm_write(struct file *file, const char __user *buf,
1662 size_t count, loff_t *offset)
1663{
1664 struct inode *inode = file_inode(file);
1665 struct task_struct *p;
1666 char buffer[TASK_COMM_LEN];
1667 const size_t maxlen = sizeof(buffer) - 1;
1668
1669 memset(buffer, 0, sizeof(buffer));
1670 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1671 return -EFAULT;
1672
1673 p = get_proc_task(inode);
1674 if (!p)
1675 return -ESRCH;
1676
1677 if (same_thread_group(current, p))
1678 set_task_comm(p, buffer);
1679 else
1680 count = -EINVAL;
1681
1682 put_task_struct(p);
1683
1684 return count;
1685}
1686
1687static int comm_show(struct seq_file *m, void *v)
1688{
1689 struct inode *inode = m->private;
1690 struct task_struct *p;
1691
1692 p = get_proc_task(inode);
1693 if (!p)
1694 return -ESRCH;
1695
1696 proc_task_name(m, p, false);
1697 seq_putc(m, '\n');
1698
1699 put_task_struct(p);
1700
1701 return 0;
1702}
1703
1704static int comm_open(struct inode *inode, struct file *filp)
1705{
1706 return single_open(filp, comm_show, inode);
1707}
1708
1709static const struct file_operations proc_pid_set_comm_operations = {
1710 .open = comm_open,
1711 .read = seq_read,
1712 .write = comm_write,
1713 .llseek = seq_lseek,
1714 .release = single_release,
1715};
1716
1717static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1718{
1719 struct task_struct *task;
1720 struct file *exe_file;
1721
1722 task = get_proc_task(d_inode(dentry));
1723 if (!task)
1724 return -ENOENT;
1725 exe_file = get_task_exe_file(task);
1726 put_task_struct(task);
1727 if (exe_file) {
1728 *exe_path = exe_file->f_path;
1729 path_get(&exe_file->f_path);
1730 fput(exe_file);
1731 return 0;
1732 } else
1733 return -ENOENT;
1734}
1735
1736static const char *proc_pid_get_link(struct dentry *dentry,
1737 struct inode *inode,
1738 struct delayed_call *done)
1739{
1740 struct path path;
1741 int error = -EACCES;
1742
1743 if (!dentry)
1744 return ERR_PTR(-ECHILD);
1745
1746 /* Are we allowed to snoop on the tasks file descriptors? */
1747 if (!proc_fd_access_allowed(inode))
1748 goto out;
1749
1750 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1751 if (error)
1752 goto out;
1753
1754 error = nd_jump_link(&path);
1755out:
1756 return ERR_PTR(error);
1757}
1758
1759static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1760{
1761 char *tmp = (char *)__get_free_page(GFP_KERNEL);
1762 char *pathname;
1763 int len;
1764
1765 if (!tmp)
1766 return -ENOMEM;
1767
1768 pathname = d_path(path, tmp, PAGE_SIZE);
1769 len = PTR_ERR(pathname);
1770 if (IS_ERR(pathname))
1771 goto out;
1772 len = tmp + PAGE_SIZE - 1 - pathname;
1773
1774 if (len > buflen)
1775 len = buflen;
1776 if (copy_to_user(buffer, pathname, len))
1777 len = -EFAULT;
1778 out:
1779 free_page((unsigned long)tmp);
1780 return len;
1781}
1782
1783static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1784{
1785 int error = -EACCES;
1786 struct inode *inode = d_inode(dentry);
1787 struct path path;
1788
1789 /* Are we allowed to snoop on the tasks file descriptors? */
1790 if (!proc_fd_access_allowed(inode))
1791 goto out;
1792
1793 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1794 if (error)
1795 goto out;
1796
1797 error = do_proc_readlink(&path, buffer, buflen);
1798 path_put(&path);
1799out:
1800 return error;
1801}
1802
1803const struct inode_operations proc_pid_link_inode_operations = {
1804 .readlink = proc_pid_readlink,
1805 .get_link = proc_pid_get_link,
1806 .setattr = proc_setattr,
1807};
1808
1809
1810/* building an inode */
1811
1812void task_dump_owner(struct task_struct *task, umode_t mode,
1813 kuid_t *ruid, kgid_t *rgid)
1814{
1815 /* Depending on the state of dumpable compute who should own a
1816 * proc file for a task.
1817 */
1818 const struct cred *cred;
1819 kuid_t uid;
1820 kgid_t gid;
1821
1822 if (unlikely(task->flags & PF_KTHREAD)) {
1823 *ruid = GLOBAL_ROOT_UID;
1824 *rgid = GLOBAL_ROOT_GID;
1825 return;
1826 }
1827
1828 /* Default to the tasks effective ownership */
1829 rcu_read_lock();
1830 cred = __task_cred(task);
1831 uid = cred->euid;
1832 gid = cred->egid;
1833 rcu_read_unlock();
1834
1835 /*
1836 * Before the /proc/pid/status file was created the only way to read
1837 * the effective uid of a /process was to stat /proc/pid. Reading
1838 * /proc/pid/status is slow enough that procps and other packages
1839 * kept stating /proc/pid. To keep the rules in /proc simple I have
1840 * made this apply to all per process world readable and executable
1841 * directories.
1842 */
1843 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1844 struct mm_struct *mm;
1845 task_lock(task);
1846 mm = task->mm;
1847 /* Make non-dumpable tasks owned by some root */
1848 if (mm) {
1849 if (get_dumpable(mm) != SUID_DUMP_USER) {
1850 struct user_namespace *user_ns = mm->user_ns;
1851
1852 uid = make_kuid(user_ns, 0);
1853 if (!uid_valid(uid))
1854 uid = GLOBAL_ROOT_UID;
1855
1856 gid = make_kgid(user_ns, 0);
1857 if (!gid_valid(gid))
1858 gid = GLOBAL_ROOT_GID;
1859 }
1860 } else {
1861 uid = GLOBAL_ROOT_UID;
1862 gid = GLOBAL_ROOT_GID;
1863 }
1864 task_unlock(task);
1865 }
1866 *ruid = uid;
1867 *rgid = gid;
1868}
1869
1870void proc_pid_evict_inode(struct proc_inode *ei)
1871{
1872 struct pid *pid = ei->pid;
1873
1874 if (S_ISDIR(ei->vfs_inode.i_mode)) {
1875 spin_lock(&pid->lock);
1876 hlist_del_init_rcu(&ei->sibling_inodes);
1877 spin_unlock(&pid->lock);
1878 }
1879
1880 put_pid(pid);
1881}
1882
1883struct inode *proc_pid_make_inode(struct super_block * sb,
1884 struct task_struct *task, umode_t mode)
1885{
1886 struct inode * inode;
1887 struct proc_inode *ei;
1888 struct pid *pid;
1889
1890 /* We need a new inode */
1891
1892 inode = new_inode(sb);
1893 if (!inode)
1894 goto out;
1895
1896 /* Common stuff */
1897 ei = PROC_I(inode);
1898 inode->i_mode = mode;
1899 inode->i_ino = get_next_ino();
1900 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1901 inode->i_op = &proc_def_inode_operations;
1902
1903 /*
1904 * grab the reference to task.
1905 */
1906 pid = get_task_pid(task, PIDTYPE_PID);
1907 if (!pid)
1908 goto out_unlock;
1909
1910 /* Let the pid remember us for quick removal */
1911 ei->pid = pid;
1912 if (S_ISDIR(mode)) {
1913 spin_lock(&pid->lock);
1914 hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes);
1915 spin_unlock(&pid->lock);
1916 }
1917
1918 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1919 security_task_to_inode(task, inode);
1920
1921out:
1922 return inode;
1923
1924out_unlock:
1925 iput(inode);
1926 return NULL;
1927}
1928
1929int pid_getattr(struct user_namespace *mnt_userns, const struct path *path,
1930 struct kstat *stat, u32 request_mask, unsigned int query_flags)
1931{
1932 struct inode *inode = d_inode(path->dentry);
1933 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
1934 struct task_struct *task;
1935
1936 generic_fillattr(&init_user_ns, inode, stat);
1937
1938 stat->uid = GLOBAL_ROOT_UID;
1939 stat->gid = GLOBAL_ROOT_GID;
1940 rcu_read_lock();
1941 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1942 if (task) {
1943 if (!has_pid_permissions(fs_info, task, HIDEPID_INVISIBLE)) {
1944 rcu_read_unlock();
1945 /*
1946 * This doesn't prevent learning whether PID exists,
1947 * it only makes getattr() consistent with readdir().
1948 */
1949 return -ENOENT;
1950 }
1951 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1952 }
1953 rcu_read_unlock();
1954 return 0;
1955}
1956
1957/* dentry stuff */
1958
1959/*
1960 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
1961 */
1962void pid_update_inode(struct task_struct *task, struct inode *inode)
1963{
1964 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1965
1966 inode->i_mode &= ~(S_ISUID | S_ISGID);
1967 security_task_to_inode(task, inode);
1968}
1969
1970/*
1971 * Rewrite the inode's ownerships here because the owning task may have
1972 * performed a setuid(), etc.
1973 *
1974 */
1975static int pid_revalidate(struct dentry *dentry, unsigned int flags)
1976{
1977 struct inode *inode;
1978 struct task_struct *task;
1979
1980 if (flags & LOOKUP_RCU)
1981 return -ECHILD;
1982
1983 inode = d_inode(dentry);
1984 task = get_proc_task(inode);
1985
1986 if (task) {
1987 pid_update_inode(task, inode);
1988 put_task_struct(task);
1989 return 1;
1990 }
1991 return 0;
1992}
1993
1994static inline bool proc_inode_is_dead(struct inode *inode)
1995{
1996 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1997}
1998
1999int pid_delete_dentry(const struct dentry *dentry)
2000{
2001 /* Is the task we represent dead?
2002 * If so, then don't put the dentry on the lru list,
2003 * kill it immediately.
2004 */
2005 return proc_inode_is_dead(d_inode(dentry));
2006}
2007
2008const struct dentry_operations pid_dentry_operations =
2009{
2010 .d_revalidate = pid_revalidate,
2011 .d_delete = pid_delete_dentry,
2012};
2013
2014/* Lookups */
2015
2016/*
2017 * Fill a directory entry.
2018 *
2019 * If possible create the dcache entry and derive our inode number and
2020 * file type from dcache entry.
2021 *
2022 * Since all of the proc inode numbers are dynamically generated, the inode
2023 * numbers do not exist until the inode is cache. This means creating
2024 * the dcache entry in readdir is necessary to keep the inode numbers
2025 * reported by readdir in sync with the inode numbers reported
2026 * by stat.
2027 */
2028bool proc_fill_cache(struct file *file, struct dir_context *ctx,
2029 const char *name, unsigned int len,
2030 instantiate_t instantiate, struct task_struct *task, const void *ptr)
2031{
2032 struct dentry *child, *dir = file->f_path.dentry;
2033 struct qstr qname = QSTR_INIT(name, len);
2034 struct inode *inode;
2035 unsigned type = DT_UNKNOWN;
2036 ino_t ino = 1;
2037
2038 child = d_hash_and_lookup(dir, &qname);
2039 if (!child) {
2040 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
2041 child = d_alloc_parallel(dir, &qname, &wq);
2042 if (IS_ERR(child))
2043 goto end_instantiate;
2044 if (d_in_lookup(child)) {
2045 struct dentry *res;
2046 res = instantiate(child, task, ptr);
2047 d_lookup_done(child);
2048 if (unlikely(res)) {
2049 dput(child);
2050 child = res;
2051 if (IS_ERR(child))
2052 goto end_instantiate;
2053 }
2054 }
2055 }
2056 inode = d_inode(child);
2057 ino = inode->i_ino;
2058 type = inode->i_mode >> 12;
2059 dput(child);
2060end_instantiate:
2061 return dir_emit(ctx, name, len, ino, type);
2062}
2063
2064/*
2065 * dname_to_vma_addr - maps a dentry name into two unsigned longs
2066 * which represent vma start and end addresses.
2067 */
2068static int dname_to_vma_addr(struct dentry *dentry,
2069 unsigned long *start, unsigned long *end)
2070{
2071 const char *str = dentry->d_name.name;
2072 unsigned long long sval, eval;
2073 unsigned int len;
2074
2075 if (str[0] == '0' && str[1] != '-')
2076 return -EINVAL;
2077 len = _parse_integer(str, 16, &sval);
2078 if (len & KSTRTOX_OVERFLOW)
2079 return -EINVAL;
2080 if (sval != (unsigned long)sval)
2081 return -EINVAL;
2082 str += len;
2083
2084 if (*str != '-')
2085 return -EINVAL;
2086 str++;
2087
2088 if (str[0] == '0' && str[1])
2089 return -EINVAL;
2090 len = _parse_integer(str, 16, &eval);
2091 if (len & KSTRTOX_OVERFLOW)
2092 return -EINVAL;
2093 if (eval != (unsigned long)eval)
2094 return -EINVAL;
2095 str += len;
2096
2097 if (*str != '\0')
2098 return -EINVAL;
2099
2100 *start = sval;
2101 *end = eval;
2102
2103 return 0;
2104}
2105
2106static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
2107{
2108 unsigned long vm_start, vm_end;
2109 bool exact_vma_exists = false;
2110 struct mm_struct *mm = NULL;
2111 struct task_struct *task;
2112 struct inode *inode;
2113 int status = 0;
2114
2115 if (flags & LOOKUP_RCU)
2116 return -ECHILD;
2117
2118 inode = d_inode(dentry);
2119 task = get_proc_task(inode);
2120 if (!task)
2121 goto out_notask;
2122
2123 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
2124 if (IS_ERR_OR_NULL(mm))
2125 goto out;
2126
2127 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2128 status = mmap_read_lock_killable(mm);
2129 if (!status) {
2130 exact_vma_exists = !!find_exact_vma(mm, vm_start,
2131 vm_end);
2132 mmap_read_unlock(mm);
2133 }
2134 }
2135
2136 mmput(mm);
2137
2138 if (exact_vma_exists) {
2139 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
2140
2141 security_task_to_inode(task, inode);
2142 status = 1;
2143 }
2144
2145out:
2146 put_task_struct(task);
2147
2148out_notask:
2149 return status;
2150}
2151
2152static const struct dentry_operations tid_map_files_dentry_operations = {
2153 .d_revalidate = map_files_d_revalidate,
2154 .d_delete = pid_delete_dentry,
2155};
2156
2157static int map_files_get_link(struct dentry *dentry, struct path *path)
2158{
2159 unsigned long vm_start, vm_end;
2160 struct vm_area_struct *vma;
2161 struct task_struct *task;
2162 struct mm_struct *mm;
2163 int rc;
2164
2165 rc = -ENOENT;
2166 task = get_proc_task(d_inode(dentry));
2167 if (!task)
2168 goto out;
2169
2170 mm = get_task_mm(task);
2171 put_task_struct(task);
2172 if (!mm)
2173 goto out;
2174
2175 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2176 if (rc)
2177 goto out_mmput;
2178
2179 rc = mmap_read_lock_killable(mm);
2180 if (rc)
2181 goto out_mmput;
2182
2183 rc = -ENOENT;
2184 vma = find_exact_vma(mm, vm_start, vm_end);
2185 if (vma && vma->vm_file) {
2186 *path = vma->vm_file->f_path;
2187 path_get(path);
2188 rc = 0;
2189 }
2190 mmap_read_unlock(mm);
2191
2192out_mmput:
2193 mmput(mm);
2194out:
2195 return rc;
2196}
2197
2198struct map_files_info {
2199 unsigned long start;
2200 unsigned long end;
2201 fmode_t mode;
2202};
2203
2204/*
2205 * Only allow CAP_SYS_ADMIN and CAP_CHECKPOINT_RESTORE to follow the links, due
2206 * to concerns about how the symlinks may be used to bypass permissions on
2207 * ancestor directories in the path to the file in question.
2208 */
2209static const char *
2210proc_map_files_get_link(struct dentry *dentry,
2211 struct inode *inode,
2212 struct delayed_call *done)
2213{
2214 if (!checkpoint_restore_ns_capable(&init_user_ns))
2215 return ERR_PTR(-EPERM);
2216
2217 return proc_pid_get_link(dentry, inode, done);
2218}
2219
2220/*
2221 * Identical to proc_pid_link_inode_operations except for get_link()
2222 */
2223static const struct inode_operations proc_map_files_link_inode_operations = {
2224 .readlink = proc_pid_readlink,
2225 .get_link = proc_map_files_get_link,
2226 .setattr = proc_setattr,
2227};
2228
2229static struct dentry *
2230proc_map_files_instantiate(struct dentry *dentry,
2231 struct task_struct *task, const void *ptr)
2232{
2233 fmode_t mode = (fmode_t)(unsigned long)ptr;
2234 struct proc_inode *ei;
2235 struct inode *inode;
2236
2237 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
2238 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2239 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2240 if (!inode)
2241 return ERR_PTR(-ENOENT);
2242
2243 ei = PROC_I(inode);
2244 ei->op.proc_get_link = map_files_get_link;
2245
2246 inode->i_op = &proc_map_files_link_inode_operations;
2247 inode->i_size = 64;
2248
2249 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2250 return d_splice_alias(inode, dentry);
2251}
2252
2253static struct dentry *proc_map_files_lookup(struct inode *dir,
2254 struct dentry *dentry, unsigned int flags)
2255{
2256 unsigned long vm_start, vm_end;
2257 struct vm_area_struct *vma;
2258 struct task_struct *task;
2259 struct dentry *result;
2260 struct mm_struct *mm;
2261
2262 result = ERR_PTR(-ENOENT);
2263 task = get_proc_task(dir);
2264 if (!task)
2265 goto out;
2266
2267 result = ERR_PTR(-EACCES);
2268 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2269 goto out_put_task;
2270
2271 result = ERR_PTR(-ENOENT);
2272 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2273 goto out_put_task;
2274
2275 mm = get_task_mm(task);
2276 if (!mm)
2277 goto out_put_task;
2278
2279 result = ERR_PTR(-EINTR);
2280 if (mmap_read_lock_killable(mm))
2281 goto out_put_mm;
2282
2283 result = ERR_PTR(-ENOENT);
2284 vma = find_exact_vma(mm, vm_start, vm_end);
2285 if (!vma)
2286 goto out_no_vma;
2287
2288 if (vma->vm_file)
2289 result = proc_map_files_instantiate(dentry, task,
2290 (void *)(unsigned long)vma->vm_file->f_mode);
2291
2292out_no_vma:
2293 mmap_read_unlock(mm);
2294out_put_mm:
2295 mmput(mm);
2296out_put_task:
2297 put_task_struct(task);
2298out:
2299 return result;
2300}
2301
2302static const struct inode_operations proc_map_files_inode_operations = {
2303 .lookup = proc_map_files_lookup,
2304 .permission = proc_fd_permission,
2305 .setattr = proc_setattr,
2306};
2307
2308static int
2309proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2310{
2311 struct vm_area_struct *vma;
2312 struct task_struct *task;
2313 struct mm_struct *mm;
2314 unsigned long nr_files, pos, i;
2315 GENRADIX(struct map_files_info) fa;
2316 struct map_files_info *p;
2317 int ret;
2318
2319 genradix_init(&fa);
2320
2321 ret = -ENOENT;
2322 task = get_proc_task(file_inode(file));
2323 if (!task)
2324 goto out;
2325
2326 ret = -EACCES;
2327 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2328 goto out_put_task;
2329
2330 ret = 0;
2331 if (!dir_emit_dots(file, ctx))
2332 goto out_put_task;
2333
2334 mm = get_task_mm(task);
2335 if (!mm)
2336 goto out_put_task;
2337
2338 ret = mmap_read_lock_killable(mm);
2339 if (ret) {
2340 mmput(mm);
2341 goto out_put_task;
2342 }
2343
2344 nr_files = 0;
2345
2346 /*
2347 * We need two passes here:
2348 *
2349 * 1) Collect vmas of mapped files with mmap_lock taken
2350 * 2) Release mmap_lock and instantiate entries
2351 *
2352 * otherwise we get lockdep complained, since filldir()
2353 * routine might require mmap_lock taken in might_fault().
2354 */
2355
2356 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2357 if (!vma->vm_file)
2358 continue;
2359 if (++pos <= ctx->pos)
2360 continue;
2361
2362 p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
2363 if (!p) {
2364 ret = -ENOMEM;
2365 mmap_read_unlock(mm);
2366 mmput(mm);
2367 goto out_put_task;
2368 }
2369
2370 p->start = vma->vm_start;
2371 p->end = vma->vm_end;
2372 p->mode = vma->vm_file->f_mode;
2373 }
2374 mmap_read_unlock(mm);
2375 mmput(mm);
2376
2377 for (i = 0; i < nr_files; i++) {
2378 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2379 unsigned int len;
2380
2381 p = genradix_ptr(&fa, i);
2382 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2383 if (!proc_fill_cache(file, ctx,
2384 buf, len,
2385 proc_map_files_instantiate,
2386 task,
2387 (void *)(unsigned long)p->mode))
2388 break;
2389 ctx->pos++;
2390 }
2391
2392out_put_task:
2393 put_task_struct(task);
2394out:
2395 genradix_free(&fa);
2396 return ret;
2397}
2398
2399static const struct file_operations proc_map_files_operations = {
2400 .read = generic_read_dir,
2401 .iterate_shared = proc_map_files_readdir,
2402 .llseek = generic_file_llseek,
2403};
2404
2405#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2406struct timers_private {
2407 struct pid *pid;
2408 struct task_struct *task;
2409 struct sighand_struct *sighand;
2410 struct pid_namespace *ns;
2411 unsigned long flags;
2412};
2413
2414static void *timers_start(struct seq_file *m, loff_t *pos)
2415{
2416 struct timers_private *tp = m->private;
2417
2418 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2419 if (!tp->task)
2420 return ERR_PTR(-ESRCH);
2421
2422 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2423 if (!tp->sighand)
2424 return ERR_PTR(-ESRCH);
2425
2426 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2427}
2428
2429static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2430{
2431 struct timers_private *tp = m->private;
2432 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2433}
2434
2435static void timers_stop(struct seq_file *m, void *v)
2436{
2437 struct timers_private *tp = m->private;
2438
2439 if (tp->sighand) {
2440 unlock_task_sighand(tp->task, &tp->flags);
2441 tp->sighand = NULL;
2442 }
2443
2444 if (tp->task) {
2445 put_task_struct(tp->task);
2446 tp->task = NULL;
2447 }
2448}
2449
2450static int show_timer(struct seq_file *m, void *v)
2451{
2452 struct k_itimer *timer;
2453 struct timers_private *tp = m->private;
2454 int notify;
2455 static const char * const nstr[] = {
2456 [SIGEV_SIGNAL] = "signal",
2457 [SIGEV_NONE] = "none",
2458 [SIGEV_THREAD] = "thread",
2459 };
2460
2461 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2462 notify = timer->it_sigev_notify;
2463
2464 seq_printf(m, "ID: %d\n", timer->it_id);
2465 seq_printf(m, "signal: %d/%px\n",
2466 timer->sigq->info.si_signo,
2467 timer->sigq->info.si_value.sival_ptr);
2468 seq_printf(m, "notify: %s/%s.%d\n",
2469 nstr[notify & ~SIGEV_THREAD_ID],
2470 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2471 pid_nr_ns(timer->it_pid, tp->ns));
2472 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2473
2474 return 0;
2475}
2476
2477static const struct seq_operations proc_timers_seq_ops = {
2478 .start = timers_start,
2479 .next = timers_next,
2480 .stop = timers_stop,
2481 .show = show_timer,
2482};
2483
2484static int proc_timers_open(struct inode *inode, struct file *file)
2485{
2486 struct timers_private *tp;
2487
2488 tp = __seq_open_private(file, &proc_timers_seq_ops,
2489 sizeof(struct timers_private));
2490 if (!tp)
2491 return -ENOMEM;
2492
2493 tp->pid = proc_pid(inode);
2494 tp->ns = proc_pid_ns(inode->i_sb);
2495 return 0;
2496}
2497
2498static const struct file_operations proc_timers_operations = {
2499 .open = proc_timers_open,
2500 .read = seq_read,
2501 .llseek = seq_lseek,
2502 .release = seq_release_private,
2503};
2504#endif
2505
2506static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2507 size_t count, loff_t *offset)
2508{
2509 struct inode *inode = file_inode(file);
2510 struct task_struct *p;
2511 u64 slack_ns;
2512 int err;
2513
2514 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2515 if (err < 0)
2516 return err;
2517
2518 p = get_proc_task(inode);
2519 if (!p)
2520 return -ESRCH;
2521
2522 if (p != current) {
2523 rcu_read_lock();
2524 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2525 rcu_read_unlock();
2526 count = -EPERM;
2527 goto out;
2528 }
2529 rcu_read_unlock();
2530
2531 err = security_task_setscheduler(p);
2532 if (err) {
2533 count = err;
2534 goto out;
2535 }
2536 }
2537
2538 task_lock(p);
2539 if (slack_ns == 0)
2540 p->timer_slack_ns = p->default_timer_slack_ns;
2541 else
2542 p->timer_slack_ns = slack_ns;
2543 task_unlock(p);
2544
2545out:
2546 put_task_struct(p);
2547
2548 return count;
2549}
2550
2551static int timerslack_ns_show(struct seq_file *m, void *v)
2552{
2553 struct inode *inode = m->private;
2554 struct task_struct *p;
2555 int err = 0;
2556
2557 p = get_proc_task(inode);
2558 if (!p)
2559 return -ESRCH;
2560
2561 if (p != current) {
2562 rcu_read_lock();
2563 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2564 rcu_read_unlock();
2565 err = -EPERM;
2566 goto out;
2567 }
2568 rcu_read_unlock();
2569
2570 err = security_task_getscheduler(p);
2571 if (err)
2572 goto out;
2573 }
2574
2575 task_lock(p);
2576 seq_printf(m, "%llu\n", p->timer_slack_ns);
2577 task_unlock(p);
2578
2579out:
2580 put_task_struct(p);
2581
2582 return err;
2583}
2584
2585static int timerslack_ns_open(struct inode *inode, struct file *filp)
2586{
2587 return single_open(filp, timerslack_ns_show, inode);
2588}
2589
2590static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2591 .open = timerslack_ns_open,
2592 .read = seq_read,
2593 .write = timerslack_ns_write,
2594 .llseek = seq_lseek,
2595 .release = single_release,
2596};
2597
2598static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2599 struct task_struct *task, const void *ptr)
2600{
2601 const struct pid_entry *p = ptr;
2602 struct inode *inode;
2603 struct proc_inode *ei;
2604
2605 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
2606 if (!inode)
2607 return ERR_PTR(-ENOENT);
2608
2609 ei = PROC_I(inode);
2610 if (S_ISDIR(inode->i_mode))
2611 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2612 if (p->iop)
2613 inode->i_op = p->iop;
2614 if (p->fop)
2615 inode->i_fop = p->fop;
2616 ei->op = p->op;
2617 pid_update_inode(task, inode);
2618 d_set_d_op(dentry, &pid_dentry_operations);
2619 return d_splice_alias(inode, dentry);
2620}
2621
2622static struct dentry *proc_pident_lookup(struct inode *dir,
2623 struct dentry *dentry,
2624 const struct pid_entry *p,
2625 const struct pid_entry *end)
2626{
2627 struct task_struct *task = get_proc_task(dir);
2628 struct dentry *res = ERR_PTR(-ENOENT);
2629
2630 if (!task)
2631 goto out_no_task;
2632
2633 /*
2634 * Yes, it does not scale. And it should not. Don't add
2635 * new entries into /proc/<tgid>/ without very good reasons.
2636 */
2637 for (; p < end; p++) {
2638 if (p->len != dentry->d_name.len)
2639 continue;
2640 if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2641 res = proc_pident_instantiate(dentry, task, p);
2642 break;
2643 }
2644 }
2645 put_task_struct(task);
2646out_no_task:
2647 return res;
2648}
2649
2650static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2651 const struct pid_entry *ents, unsigned int nents)
2652{
2653 struct task_struct *task = get_proc_task(file_inode(file));
2654 const struct pid_entry *p;
2655
2656 if (!task)
2657 return -ENOENT;
2658
2659 if (!dir_emit_dots(file, ctx))
2660 goto out;
2661
2662 if (ctx->pos >= nents + 2)
2663 goto out;
2664
2665 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2666 if (!proc_fill_cache(file, ctx, p->name, p->len,
2667 proc_pident_instantiate, task, p))
2668 break;
2669 ctx->pos++;
2670 }
2671out:
2672 put_task_struct(task);
2673 return 0;
2674}
2675
2676#ifdef CONFIG_SECURITY
2677static int proc_pid_attr_open(struct inode *inode, struct file *file)
2678{
2679 file->private_data = NULL;
2680 __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
2681 return 0;
2682}
2683
2684static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2685 size_t count, loff_t *ppos)
2686{
2687 struct inode * inode = file_inode(file);
2688 char *p = NULL;
2689 ssize_t length;
2690 struct task_struct *task = get_proc_task(inode);
2691
2692 if (!task)
2693 return -ESRCH;
2694
2695 length = security_getprocattr(task, PROC_I(inode)->op.lsm,
2696 (char*)file->f_path.dentry->d_name.name,
2697 &p);
2698 put_task_struct(task);
2699 if (length > 0)
2700 length = simple_read_from_buffer(buf, count, ppos, p, length);
2701 kfree(p);
2702 return length;
2703}
2704
2705static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2706 size_t count, loff_t *ppos)
2707{
2708 struct inode * inode = file_inode(file);
2709 struct task_struct *task;
2710 void *page;
2711 int rv;
2712
2713 /* A task may only write when it was the opener. */
2714 if (file->private_data != current->mm)
2715 return -EPERM;
2716
2717 rcu_read_lock();
2718 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2719 if (!task) {
2720 rcu_read_unlock();
2721 return -ESRCH;
2722 }
2723 /* A task may only write its own attributes. */
2724 if (current != task) {
2725 rcu_read_unlock();
2726 return -EACCES;
2727 }
2728 /* Prevent changes to overridden credentials. */
2729 if (current_cred() != current_real_cred()) {
2730 rcu_read_unlock();
2731 return -EBUSY;
2732 }
2733 rcu_read_unlock();
2734
2735 if (count > PAGE_SIZE)
2736 count = PAGE_SIZE;
2737
2738 /* No partial writes. */
2739 if (*ppos != 0)
2740 return -EINVAL;
2741
2742 page = memdup_user(buf, count);
2743 if (IS_ERR(page)) {
2744 rv = PTR_ERR(page);
2745 goto out;
2746 }
2747
2748 /* Guard against adverse ptrace interaction */
2749 rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex);
2750 if (rv < 0)
2751 goto out_free;
2752
2753 rv = security_setprocattr(PROC_I(inode)->op.lsm,
2754 file->f_path.dentry->d_name.name, page,
2755 count);
2756 mutex_unlock(¤t->signal->cred_guard_mutex);
2757out_free:
2758 kfree(page);
2759out:
2760 return rv;
2761}
2762
2763static const struct file_operations proc_pid_attr_operations = {
2764 .open = proc_pid_attr_open,
2765 .read = proc_pid_attr_read,
2766 .write = proc_pid_attr_write,
2767 .llseek = generic_file_llseek,
2768 .release = mem_release,
2769};
2770
2771#define LSM_DIR_OPS(LSM) \
2772static int proc_##LSM##_attr_dir_iterate(struct file *filp, \
2773 struct dir_context *ctx) \
2774{ \
2775 return proc_pident_readdir(filp, ctx, \
2776 LSM##_attr_dir_stuff, \
2777 ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2778} \
2779\
2780static const struct file_operations proc_##LSM##_attr_dir_ops = { \
2781 .read = generic_read_dir, \
2782 .iterate = proc_##LSM##_attr_dir_iterate, \
2783 .llseek = default_llseek, \
2784}; \
2785\
2786static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
2787 struct dentry *dentry, unsigned int flags) \
2788{ \
2789 return proc_pident_lookup(dir, dentry, \
2790 LSM##_attr_dir_stuff, \
2791 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2792} \
2793\
2794static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
2795 .lookup = proc_##LSM##_attr_dir_lookup, \
2796 .getattr = pid_getattr, \
2797 .setattr = proc_setattr, \
2798}
2799
2800#ifdef CONFIG_SECURITY_SMACK
2801static const struct pid_entry smack_attr_dir_stuff[] = {
2802 ATTR("smack", "current", 0666),
2803};
2804LSM_DIR_OPS(smack);
2805#endif
2806
2807#ifdef CONFIG_SECURITY_APPARMOR
2808static const struct pid_entry apparmor_attr_dir_stuff[] = {
2809 ATTR("apparmor", "current", 0666),
2810 ATTR("apparmor", "prev", 0444),
2811 ATTR("apparmor", "exec", 0666),
2812};
2813LSM_DIR_OPS(apparmor);
2814#endif
2815
2816static const struct pid_entry attr_dir_stuff[] = {
2817 ATTR(NULL, "current", 0666),
2818 ATTR(NULL, "prev", 0444),
2819 ATTR(NULL, "exec", 0666),
2820 ATTR(NULL, "fscreate", 0666),
2821 ATTR(NULL, "keycreate", 0666),
2822 ATTR(NULL, "sockcreate", 0666),
2823#ifdef CONFIG_SECURITY_SMACK
2824 DIR("smack", 0555,
2825 proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
2826#endif
2827#ifdef CONFIG_SECURITY_APPARMOR
2828 DIR("apparmor", 0555,
2829 proc_apparmor_attr_dir_inode_ops, proc_apparmor_attr_dir_ops),
2830#endif
2831};
2832
2833static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2834{
2835 return proc_pident_readdir(file, ctx,
2836 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2837}
2838
2839static const struct file_operations proc_attr_dir_operations = {
2840 .read = generic_read_dir,
2841 .iterate_shared = proc_attr_dir_readdir,
2842 .llseek = generic_file_llseek,
2843};
2844
2845static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2846 struct dentry *dentry, unsigned int flags)
2847{
2848 return proc_pident_lookup(dir, dentry,
2849 attr_dir_stuff,
2850 attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
2851}
2852
2853static const struct inode_operations proc_attr_dir_inode_operations = {
2854 .lookup = proc_attr_dir_lookup,
2855 .getattr = pid_getattr,
2856 .setattr = proc_setattr,
2857};
2858
2859#endif
2860
2861#ifdef CONFIG_ELF_CORE
2862static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2863 size_t count, loff_t *ppos)
2864{
2865 struct task_struct *task = get_proc_task(file_inode(file));
2866 struct mm_struct *mm;
2867 char buffer[PROC_NUMBUF];
2868 size_t len;
2869 int ret;
2870
2871 if (!task)
2872 return -ESRCH;
2873
2874 ret = 0;
2875 mm = get_task_mm(task);
2876 if (mm) {
2877 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2878 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2879 MMF_DUMP_FILTER_SHIFT));
2880 mmput(mm);
2881 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2882 }
2883
2884 put_task_struct(task);
2885
2886 return ret;
2887}
2888
2889static ssize_t proc_coredump_filter_write(struct file *file,
2890 const char __user *buf,
2891 size_t count,
2892 loff_t *ppos)
2893{
2894 struct task_struct *task;
2895 struct mm_struct *mm;
2896 unsigned int val;
2897 int ret;
2898 int i;
2899 unsigned long mask;
2900
2901 ret = kstrtouint_from_user(buf, count, 0, &val);
2902 if (ret < 0)
2903 return ret;
2904
2905 ret = -ESRCH;
2906 task = get_proc_task(file_inode(file));
2907 if (!task)
2908 goto out_no_task;
2909
2910 mm = get_task_mm(task);
2911 if (!mm)
2912 goto out_no_mm;
2913 ret = 0;
2914
2915 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2916 if (val & mask)
2917 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2918 else
2919 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2920 }
2921
2922 mmput(mm);
2923 out_no_mm:
2924 put_task_struct(task);
2925 out_no_task:
2926 if (ret < 0)
2927 return ret;
2928 return count;
2929}
2930
2931static const struct file_operations proc_coredump_filter_operations = {
2932 .read = proc_coredump_filter_read,
2933 .write = proc_coredump_filter_write,
2934 .llseek = generic_file_llseek,
2935};
2936#endif
2937
2938#ifdef CONFIG_TASK_IO_ACCOUNTING
2939static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2940{
2941 struct task_io_accounting acct = task->ioac;
2942 unsigned long flags;
2943 int result;
2944
2945 result = down_read_killable(&task->signal->exec_update_lock);
2946 if (result)
2947 return result;
2948
2949 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2950 result = -EACCES;
2951 goto out_unlock;
2952 }
2953
2954 if (whole && lock_task_sighand(task, &flags)) {
2955 struct task_struct *t = task;
2956
2957 task_io_accounting_add(&acct, &task->signal->ioac);
2958 while_each_thread(task, t)
2959 task_io_accounting_add(&acct, &t->ioac);
2960
2961 unlock_task_sighand(task, &flags);
2962 }
2963 seq_printf(m,
2964 "rchar: %llu\n"
2965 "wchar: %llu\n"
2966 "syscr: %llu\n"
2967 "syscw: %llu\n"
2968 "read_bytes: %llu\n"
2969 "write_bytes: %llu\n"
2970 "cancelled_write_bytes: %llu\n",
2971 (unsigned long long)acct.rchar,
2972 (unsigned long long)acct.wchar,
2973 (unsigned long long)acct.syscr,
2974 (unsigned long long)acct.syscw,
2975 (unsigned long long)acct.read_bytes,
2976 (unsigned long long)acct.write_bytes,
2977 (unsigned long long)acct.cancelled_write_bytes);
2978 result = 0;
2979
2980out_unlock:
2981 up_read(&task->signal->exec_update_lock);
2982 return result;
2983}
2984
2985static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2986 struct pid *pid, struct task_struct *task)
2987{
2988 return do_io_accounting(task, m, 0);
2989}
2990
2991static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2992 struct pid *pid, struct task_struct *task)
2993{
2994 return do_io_accounting(task, m, 1);
2995}
2996#endif /* CONFIG_TASK_IO_ACCOUNTING */
2997
2998#ifdef CONFIG_USER_NS
2999static int proc_id_map_open(struct inode *inode, struct file *file,
3000 const struct seq_operations *seq_ops)
3001{
3002 struct user_namespace *ns = NULL;
3003 struct task_struct *task;
3004 struct seq_file *seq;
3005 int ret = -EINVAL;
3006
3007 task = get_proc_task(inode);
3008 if (task) {
3009 rcu_read_lock();
3010 ns = get_user_ns(task_cred_xxx(task, user_ns));
3011 rcu_read_unlock();
3012 put_task_struct(task);
3013 }
3014 if (!ns)
3015 goto err;
3016
3017 ret = seq_open(file, seq_ops);
3018 if (ret)
3019 goto err_put_ns;
3020
3021 seq = file->private_data;
3022 seq->private = ns;
3023
3024 return 0;
3025err_put_ns:
3026 put_user_ns(ns);
3027err:
3028 return ret;
3029}
3030
3031static int proc_id_map_release(struct inode *inode, struct file *file)
3032{
3033 struct seq_file *seq = file->private_data;
3034 struct user_namespace *ns = seq->private;
3035 put_user_ns(ns);
3036 return seq_release(inode, file);
3037}
3038
3039static int proc_uid_map_open(struct inode *inode, struct file *file)
3040{
3041 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
3042}
3043
3044static int proc_gid_map_open(struct inode *inode, struct file *file)
3045{
3046 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
3047}
3048
3049static int proc_projid_map_open(struct inode *inode, struct file *file)
3050{
3051 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
3052}
3053
3054static const struct file_operations proc_uid_map_operations = {
3055 .open = proc_uid_map_open,
3056 .write = proc_uid_map_write,
3057 .read = seq_read,
3058 .llseek = seq_lseek,
3059 .release = proc_id_map_release,
3060};
3061
3062static const struct file_operations proc_gid_map_operations = {
3063 .open = proc_gid_map_open,
3064 .write = proc_gid_map_write,
3065 .read = seq_read,
3066 .llseek = seq_lseek,
3067 .release = proc_id_map_release,
3068};
3069
3070static const struct file_operations proc_projid_map_operations = {
3071 .open = proc_projid_map_open,
3072 .write = proc_projid_map_write,
3073 .read = seq_read,
3074 .llseek = seq_lseek,
3075 .release = proc_id_map_release,
3076};
3077
3078static int proc_setgroups_open(struct inode *inode, struct file *file)
3079{
3080 struct user_namespace *ns = NULL;
3081 struct task_struct *task;
3082 int ret;
3083
3084 ret = -ESRCH;
3085 task = get_proc_task(inode);
3086 if (task) {
3087 rcu_read_lock();
3088 ns = get_user_ns(task_cred_xxx(task, user_ns));
3089 rcu_read_unlock();
3090 put_task_struct(task);
3091 }
3092 if (!ns)
3093 goto err;
3094
3095 if (file->f_mode & FMODE_WRITE) {
3096 ret = -EACCES;
3097 if (!ns_capable(ns, CAP_SYS_ADMIN))
3098 goto err_put_ns;
3099 }
3100
3101 ret = single_open(file, &proc_setgroups_show, ns);
3102 if (ret)
3103 goto err_put_ns;
3104
3105 return 0;
3106err_put_ns:
3107 put_user_ns(ns);
3108err:
3109 return ret;
3110}
3111
3112static int proc_setgroups_release(struct inode *inode, struct file *file)
3113{
3114 struct seq_file *seq = file->private_data;
3115 struct user_namespace *ns = seq->private;
3116 int ret = single_release(inode, file);
3117 put_user_ns(ns);
3118 return ret;
3119}
3120
3121static const struct file_operations proc_setgroups_operations = {
3122 .open = proc_setgroups_open,
3123 .write = proc_setgroups_write,
3124 .read = seq_read,
3125 .llseek = seq_lseek,
3126 .release = proc_setgroups_release,
3127};
3128#endif /* CONFIG_USER_NS */
3129
3130static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
3131 struct pid *pid, struct task_struct *task)
3132{
3133 int err = lock_trace(task);
3134 if (!err) {
3135 seq_printf(m, "%08x\n", task->personality);
3136 unlock_trace(task);
3137 }
3138 return err;
3139}
3140
3141#ifdef CONFIG_LIVEPATCH
3142static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
3143 struct pid *pid, struct task_struct *task)
3144{
3145 seq_printf(m, "%d\n", task->patch_state);
3146 return 0;
3147}
3148#endif /* CONFIG_LIVEPATCH */
3149
3150#ifdef CONFIG_STACKLEAK_METRICS
3151static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
3152 struct pid *pid, struct task_struct *task)
3153{
3154 unsigned long prev_depth = THREAD_SIZE -
3155 (task->prev_lowest_stack & (THREAD_SIZE - 1));
3156 unsigned long depth = THREAD_SIZE -
3157 (task->lowest_stack & (THREAD_SIZE - 1));
3158
3159 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
3160 prev_depth, depth);
3161 return 0;
3162}
3163#endif /* CONFIG_STACKLEAK_METRICS */
3164
3165/*
3166 * Thread groups
3167 */
3168static const struct file_operations proc_task_operations;
3169static const struct inode_operations proc_task_inode_operations;
3170
3171static const struct pid_entry tgid_base_stuff[] = {
3172 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3173 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3174 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3175 DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3176 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3177#ifdef CONFIG_NET
3178 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3179#endif
3180 REG("environ", S_IRUSR, proc_environ_operations),
3181 REG("auxv", S_IRUSR, proc_auxv_operations),
3182 ONE("status", S_IRUGO, proc_pid_status),
3183 ONE("personality", S_IRUSR, proc_pid_personality),
3184 ONE("limits", S_IRUGO, proc_pid_limits),
3185#ifdef CONFIG_SCHED_DEBUG
3186 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3187#endif
3188#ifdef CONFIG_SCHED_AUTOGROUP
3189 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3190#endif
3191#ifdef CONFIG_TIME_NS
3192 REG("timens_offsets", S_IRUGO|S_IWUSR, proc_timens_offsets_operations),
3193#endif
3194 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3195#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3196 ONE("syscall", S_IRUSR, proc_pid_syscall),
3197#endif
3198 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3199 ONE("stat", S_IRUGO, proc_tgid_stat),
3200 ONE("statm", S_IRUGO, proc_pid_statm),
3201 REG("maps", S_IRUGO, proc_pid_maps_operations),
3202#ifdef CONFIG_NUMA
3203 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3204#endif
3205 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3206 LNK("cwd", proc_cwd_link),
3207 LNK("root", proc_root_link),
3208 LNK("exe", proc_exe_link),
3209 REG("mounts", S_IRUGO, proc_mounts_operations),
3210 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3211 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3212#ifdef CONFIG_PROC_PAGE_MONITOR
3213 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3214 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3215 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3216 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3217#endif
3218#ifdef CONFIG_SECURITY
3219 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3220#endif
3221#ifdef CONFIG_KALLSYMS
3222 ONE("wchan", S_IRUGO, proc_pid_wchan),
3223#endif
3224#ifdef CONFIG_STACKTRACE
3225 ONE("stack", S_IRUSR, proc_pid_stack),
3226#endif
3227#ifdef CONFIG_SCHED_INFO
3228 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3229#endif
3230#ifdef CONFIG_LATENCYTOP
3231 REG("latency", S_IRUGO, proc_lstats_operations),
3232#endif
3233#ifdef CONFIG_PROC_PID_CPUSET
3234 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3235#endif
3236#ifdef CONFIG_CGROUPS
3237 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3238#endif
3239#ifdef CONFIG_PROC_CPU_RESCTRL
3240 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3241#endif
3242 ONE("oom_score", S_IRUGO, proc_oom_score),
3243 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3244 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3245#ifdef CONFIG_AUDIT
3246 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3247 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3248#endif
3249#ifdef CONFIG_FAULT_INJECTION
3250 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3251 REG("fail-nth", 0644, proc_fail_nth_operations),
3252#endif
3253#ifdef CONFIG_ELF_CORE
3254 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3255#endif
3256#ifdef CONFIG_TASK_IO_ACCOUNTING
3257 ONE("io", S_IRUSR, proc_tgid_io_accounting),
3258#endif
3259#ifdef CONFIG_USER_NS
3260 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3261 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3262 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3263 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3264#endif
3265#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3266 REG("timers", S_IRUGO, proc_timers_operations),
3267#endif
3268 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3269#ifdef CONFIG_LIVEPATCH
3270 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3271#endif
3272#ifdef CONFIG_STACKLEAK_METRICS
3273 ONE("stack_depth", S_IRUGO, proc_stack_depth),
3274#endif
3275#ifdef CONFIG_PROC_PID_ARCH_STATUS
3276 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3277#endif
3278#ifdef CONFIG_SECCOMP_CACHE_DEBUG
3279 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3280#endif
3281};
3282
3283static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3284{
3285 return proc_pident_readdir(file, ctx,
3286 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3287}
3288
3289static const struct file_operations proc_tgid_base_operations = {
3290 .read = generic_read_dir,
3291 .iterate_shared = proc_tgid_base_readdir,
3292 .llseek = generic_file_llseek,
3293};
3294
3295struct pid *tgid_pidfd_to_pid(const struct file *file)
3296{
3297 if (file->f_op != &proc_tgid_base_operations)
3298 return ERR_PTR(-EBADF);
3299
3300 return proc_pid(file_inode(file));
3301}
3302
3303static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3304{
3305 return proc_pident_lookup(dir, dentry,
3306 tgid_base_stuff,
3307 tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
3308}
3309
3310static const struct inode_operations proc_tgid_base_inode_operations = {
3311 .lookup = proc_tgid_base_lookup,
3312 .getattr = pid_getattr,
3313 .setattr = proc_setattr,
3314 .permission = proc_pid_permission,
3315};
3316
3317/**
3318 * proc_flush_pid - Remove dcache entries for @pid from the /proc dcache.
3319 * @pid: pid that should be flushed.
3320 *
3321 * This function walks a list of inodes (that belong to any proc
3322 * filesystem) that are attached to the pid and flushes them from
3323 * the dentry cache.
3324 *
3325 * It is safe and reasonable to cache /proc entries for a task until
3326 * that task exits. After that they just clog up the dcache with
3327 * useless entries, possibly causing useful dcache entries to be
3328 * flushed instead. This routine is provided to flush those useless
3329 * dcache entries when a process is reaped.
3330 *
3331 * NOTE: This routine is just an optimization so it does not guarantee
3332 * that no dcache entries will exist after a process is reaped
3333 * it just makes it very unlikely that any will persist.
3334 */
3335
3336void proc_flush_pid(struct pid *pid)
3337{
3338 proc_invalidate_siblings_dcache(&pid->inodes, &pid->lock);
3339}
3340
3341static struct dentry *proc_pid_instantiate(struct dentry * dentry,
3342 struct task_struct *task, const void *ptr)
3343{
3344 struct inode *inode;
3345
3346 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3347 if (!inode)
3348 return ERR_PTR(-ENOENT);
3349
3350 inode->i_op = &proc_tgid_base_inode_operations;
3351 inode->i_fop = &proc_tgid_base_operations;
3352 inode->i_flags|=S_IMMUTABLE;
3353
3354 set_nlink(inode, nlink_tgid);
3355 pid_update_inode(task, inode);
3356
3357 d_set_d_op(dentry, &pid_dentry_operations);
3358 return d_splice_alias(inode, dentry);
3359}
3360
3361struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
3362{
3363 struct task_struct *task;
3364 unsigned tgid;
3365 struct proc_fs_info *fs_info;
3366 struct pid_namespace *ns;
3367 struct dentry *result = ERR_PTR(-ENOENT);
3368
3369 tgid = name_to_int(&dentry->d_name);
3370 if (tgid == ~0U)
3371 goto out;
3372
3373 fs_info = proc_sb_info(dentry->d_sb);
3374 ns = fs_info->pid_ns;
3375 rcu_read_lock();
3376 task = find_task_by_pid_ns(tgid, ns);
3377 if (task)
3378 get_task_struct(task);
3379 rcu_read_unlock();
3380 if (!task)
3381 goto out;
3382
3383 /* Limit procfs to only ptraceable tasks */
3384 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE) {
3385 if (!has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS))
3386 goto out_put_task;
3387 }
3388
3389 result = proc_pid_instantiate(dentry, task, NULL);
3390out_put_task:
3391 put_task_struct(task);
3392out:
3393 return result;
3394}
3395
3396/*
3397 * Find the first task with tgid >= tgid
3398 *
3399 */
3400struct tgid_iter {
3401 unsigned int tgid;
3402 struct task_struct *task;
3403};
3404static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3405{
3406 struct pid *pid;
3407
3408 if (iter.task)
3409 put_task_struct(iter.task);
3410 rcu_read_lock();
3411retry:
3412 iter.task = NULL;
3413 pid = find_ge_pid(iter.tgid, ns);
3414 if (pid) {
3415 iter.tgid = pid_nr_ns(pid, ns);
3416 iter.task = pid_task(pid, PIDTYPE_TGID);
3417 if (!iter.task) {
3418 iter.tgid += 1;
3419 goto retry;
3420 }
3421 get_task_struct(iter.task);
3422 }
3423 rcu_read_unlock();
3424 return iter;
3425}
3426
3427#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3428
3429/* for the /proc/ directory itself, after non-process stuff has been done */
3430int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3431{
3432 struct tgid_iter iter;
3433 struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb);
3434 struct pid_namespace *ns = proc_pid_ns(file_inode(file)->i_sb);
3435 loff_t pos = ctx->pos;
3436
3437 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3438 return 0;
3439
3440 if (pos == TGID_OFFSET - 2) {
3441 struct inode *inode = d_inode(fs_info->proc_self);
3442 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3443 return 0;
3444 ctx->pos = pos = pos + 1;
3445 }
3446 if (pos == TGID_OFFSET - 1) {
3447 struct inode *inode = d_inode(fs_info->proc_thread_self);
3448 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3449 return 0;
3450 ctx->pos = pos = pos + 1;
3451 }
3452 iter.tgid = pos - TGID_OFFSET;
3453 iter.task = NULL;
3454 for (iter = next_tgid(ns, iter);
3455 iter.task;
3456 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3457 char name[10 + 1];
3458 unsigned int len;
3459
3460 cond_resched();
3461 if (!has_pid_permissions(fs_info, iter.task, HIDEPID_INVISIBLE))
3462 continue;
3463
3464 len = snprintf(name, sizeof(name), "%u", iter.tgid);
3465 ctx->pos = iter.tgid + TGID_OFFSET;
3466 if (!proc_fill_cache(file, ctx, name, len,
3467 proc_pid_instantiate, iter.task, NULL)) {
3468 put_task_struct(iter.task);
3469 return 0;
3470 }
3471 }
3472 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3473 return 0;
3474}
3475
3476/*
3477 * proc_tid_comm_permission is a special permission function exclusively
3478 * used for the node /proc/<pid>/task/<tid>/comm.
3479 * It bypasses generic permission checks in the case where a task of the same
3480 * task group attempts to access the node.
3481 * The rationale behind this is that glibc and bionic access this node for
3482 * cross thread naming (pthread_set/getname_np(!self)). However, if
3483 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3484 * which locks out the cross thread naming implementation.
3485 * This function makes sure that the node is always accessible for members of
3486 * same thread group.
3487 */
3488static int proc_tid_comm_permission(struct user_namespace *mnt_userns,
3489 struct inode *inode, int mask)
3490{
3491 bool is_same_tgroup;
3492 struct task_struct *task;
3493
3494 task = get_proc_task(inode);
3495 if (!task)
3496 return -ESRCH;
3497 is_same_tgroup = same_thread_group(current, task);
3498 put_task_struct(task);
3499
3500 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3501 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3502 * read or written by the members of the corresponding
3503 * thread group.
3504 */
3505 return 0;
3506 }
3507
3508 return generic_permission(&init_user_ns, inode, mask);
3509}
3510
3511static const struct inode_operations proc_tid_comm_inode_operations = {
3512 .permission = proc_tid_comm_permission,
3513};
3514
3515/*
3516 * Tasks
3517 */
3518static const struct pid_entry tid_base_stuff[] = {
3519 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3520 DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3521 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3522#ifdef CONFIG_NET
3523 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3524#endif
3525 REG("environ", S_IRUSR, proc_environ_operations),
3526 REG("auxv", S_IRUSR, proc_auxv_operations),
3527 ONE("status", S_IRUGO, proc_pid_status),
3528 ONE("personality", S_IRUSR, proc_pid_personality),
3529 ONE("limits", S_IRUGO, proc_pid_limits),
3530#ifdef CONFIG_SCHED_DEBUG
3531 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3532#endif
3533 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3534 &proc_tid_comm_inode_operations,
3535 &proc_pid_set_comm_operations, {}),
3536#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3537 ONE("syscall", S_IRUSR, proc_pid_syscall),
3538#endif
3539 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3540 ONE("stat", S_IRUGO, proc_tid_stat),
3541 ONE("statm", S_IRUGO, proc_pid_statm),
3542 REG("maps", S_IRUGO, proc_pid_maps_operations),
3543#ifdef CONFIG_PROC_CHILDREN
3544 REG("children", S_IRUGO, proc_tid_children_operations),
3545#endif
3546#ifdef CONFIG_NUMA
3547 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3548#endif
3549 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3550 LNK("cwd", proc_cwd_link),
3551 LNK("root", proc_root_link),
3552 LNK("exe", proc_exe_link),
3553 REG("mounts", S_IRUGO, proc_mounts_operations),
3554 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3555#ifdef CONFIG_PROC_PAGE_MONITOR
3556 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3557 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3558 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3559 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3560#endif
3561#ifdef CONFIG_SECURITY
3562 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3563#endif
3564#ifdef CONFIG_KALLSYMS
3565 ONE("wchan", S_IRUGO, proc_pid_wchan),
3566#endif
3567#ifdef CONFIG_STACKTRACE
3568 ONE("stack", S_IRUSR, proc_pid_stack),
3569#endif
3570#ifdef CONFIG_SCHED_INFO
3571 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3572#endif
3573#ifdef CONFIG_LATENCYTOP
3574 REG("latency", S_IRUGO, proc_lstats_operations),
3575#endif
3576#ifdef CONFIG_PROC_PID_CPUSET
3577 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3578#endif
3579#ifdef CONFIG_CGROUPS
3580 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3581#endif
3582#ifdef CONFIG_PROC_CPU_RESCTRL
3583 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3584#endif
3585 ONE("oom_score", S_IRUGO, proc_oom_score),
3586 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3587 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3588#ifdef CONFIG_AUDIT
3589 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3590 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3591#endif
3592#ifdef CONFIG_FAULT_INJECTION
3593 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3594 REG("fail-nth", 0644, proc_fail_nth_operations),
3595#endif
3596#ifdef CONFIG_TASK_IO_ACCOUNTING
3597 ONE("io", S_IRUSR, proc_tid_io_accounting),
3598#endif
3599#ifdef CONFIG_USER_NS
3600 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3601 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3602 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3603 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3604#endif
3605#ifdef CONFIG_LIVEPATCH
3606 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3607#endif
3608#ifdef CONFIG_PROC_PID_ARCH_STATUS
3609 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3610#endif
3611#ifdef CONFIG_SECCOMP_CACHE_DEBUG
3612 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3613#endif
3614};
3615
3616static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3617{
3618 return proc_pident_readdir(file, ctx,
3619 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3620}
3621
3622static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3623{
3624 return proc_pident_lookup(dir, dentry,
3625 tid_base_stuff,
3626 tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
3627}
3628
3629static const struct file_operations proc_tid_base_operations = {
3630 .read = generic_read_dir,
3631 .iterate_shared = proc_tid_base_readdir,
3632 .llseek = generic_file_llseek,
3633};
3634
3635static const struct inode_operations proc_tid_base_inode_operations = {
3636 .lookup = proc_tid_base_lookup,
3637 .getattr = pid_getattr,
3638 .setattr = proc_setattr,
3639};
3640
3641static struct dentry *proc_task_instantiate(struct dentry *dentry,
3642 struct task_struct *task, const void *ptr)
3643{
3644 struct inode *inode;
3645 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3646 if (!inode)
3647 return ERR_PTR(-ENOENT);
3648
3649 inode->i_op = &proc_tid_base_inode_operations;
3650 inode->i_fop = &proc_tid_base_operations;
3651 inode->i_flags |= S_IMMUTABLE;
3652
3653 set_nlink(inode, nlink_tid);
3654 pid_update_inode(task, inode);
3655
3656 d_set_d_op(dentry, &pid_dentry_operations);
3657 return d_splice_alias(inode, dentry);
3658}
3659
3660static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3661{
3662 struct task_struct *task;
3663 struct task_struct *leader = get_proc_task(dir);
3664 unsigned tid;
3665 struct proc_fs_info *fs_info;
3666 struct pid_namespace *ns;
3667 struct dentry *result = ERR_PTR(-ENOENT);
3668
3669 if (!leader)
3670 goto out_no_task;
3671
3672 tid = name_to_int(&dentry->d_name);
3673 if (tid == ~0U)
3674 goto out;
3675
3676 fs_info = proc_sb_info(dentry->d_sb);
3677 ns = fs_info->pid_ns;
3678 rcu_read_lock();
3679 task = find_task_by_pid_ns(tid, ns);
3680 if (task)
3681 get_task_struct(task);
3682 rcu_read_unlock();
3683 if (!task)
3684 goto out;
3685 if (!same_thread_group(leader, task))
3686 goto out_drop_task;
3687
3688 result = proc_task_instantiate(dentry, task, NULL);
3689out_drop_task:
3690 put_task_struct(task);
3691out:
3692 put_task_struct(leader);
3693out_no_task:
3694 return result;
3695}
3696
3697/*
3698 * Find the first tid of a thread group to return to user space.
3699 *
3700 * Usually this is just the thread group leader, but if the users
3701 * buffer was too small or there was a seek into the middle of the
3702 * directory we have more work todo.
3703 *
3704 * In the case of a short read we start with find_task_by_pid.
3705 *
3706 * In the case of a seek we start with the leader and walk nr
3707 * threads past it.
3708 */
3709static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3710 struct pid_namespace *ns)
3711{
3712 struct task_struct *pos, *task;
3713 unsigned long nr = f_pos;
3714
3715 if (nr != f_pos) /* 32bit overflow? */
3716 return NULL;
3717
3718 rcu_read_lock();
3719 task = pid_task(pid, PIDTYPE_PID);
3720 if (!task)
3721 goto fail;
3722
3723 /* Attempt to start with the tid of a thread */
3724 if (tid && nr) {
3725 pos = find_task_by_pid_ns(tid, ns);
3726 if (pos && same_thread_group(pos, task))
3727 goto found;
3728 }
3729
3730 /* If nr exceeds the number of threads there is nothing todo */
3731 if (nr >= get_nr_threads(task))
3732 goto fail;
3733
3734 /* If we haven't found our starting place yet start
3735 * with the leader and walk nr threads forward.
3736 */
3737 pos = task = task->group_leader;
3738 do {
3739 if (!nr--)
3740 goto found;
3741 } while_each_thread(task, pos);
3742fail:
3743 pos = NULL;
3744 goto out;
3745found:
3746 get_task_struct(pos);
3747out:
3748 rcu_read_unlock();
3749 return pos;
3750}
3751
3752/*
3753 * Find the next thread in the thread list.
3754 * Return NULL if there is an error or no next thread.
3755 *
3756 * The reference to the input task_struct is released.
3757 */
3758static struct task_struct *next_tid(struct task_struct *start)
3759{
3760 struct task_struct *pos = NULL;
3761 rcu_read_lock();
3762 if (pid_alive(start)) {
3763 pos = next_thread(start);
3764 if (thread_group_leader(pos))
3765 pos = NULL;
3766 else
3767 get_task_struct(pos);
3768 }
3769 rcu_read_unlock();
3770 put_task_struct(start);
3771 return pos;
3772}
3773
3774/* for the /proc/TGID/task/ directories */
3775static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3776{
3777 struct inode *inode = file_inode(file);
3778 struct task_struct *task;
3779 struct pid_namespace *ns;
3780 int tid;
3781
3782 if (proc_inode_is_dead(inode))
3783 return -ENOENT;
3784
3785 if (!dir_emit_dots(file, ctx))
3786 return 0;
3787
3788 /* f_version caches the tgid value that the last readdir call couldn't
3789 * return. lseek aka telldir automagically resets f_version to 0.
3790 */
3791 ns = proc_pid_ns(inode->i_sb);
3792 tid = (int)file->f_version;
3793 file->f_version = 0;
3794 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3795 task;
3796 task = next_tid(task), ctx->pos++) {
3797 char name[10 + 1];
3798 unsigned int len;
3799 tid = task_pid_nr_ns(task, ns);
3800 len = snprintf(name, sizeof(name), "%u", tid);
3801 if (!proc_fill_cache(file, ctx, name, len,
3802 proc_task_instantiate, task, NULL)) {
3803 /* returning this tgid failed, save it as the first
3804 * pid for the next readir call */
3805 file->f_version = (u64)tid;
3806 put_task_struct(task);
3807 break;
3808 }
3809 }
3810
3811 return 0;
3812}
3813
3814static int proc_task_getattr(struct user_namespace *mnt_userns,
3815 const struct path *path, struct kstat *stat,
3816 u32 request_mask, unsigned int query_flags)
3817{
3818 struct inode *inode = d_inode(path->dentry);
3819 struct task_struct *p = get_proc_task(inode);
3820 generic_fillattr(&init_user_ns, inode, stat);
3821
3822 if (p) {
3823 stat->nlink += get_nr_threads(p);
3824 put_task_struct(p);
3825 }
3826
3827 return 0;
3828}
3829
3830static const struct inode_operations proc_task_inode_operations = {
3831 .lookup = proc_task_lookup,
3832 .getattr = proc_task_getattr,
3833 .setattr = proc_setattr,
3834 .permission = proc_pid_permission,
3835};
3836
3837static const struct file_operations proc_task_operations = {
3838 .read = generic_read_dir,
3839 .iterate_shared = proc_task_readdir,
3840 .llseek = generic_file_llseek,
3841};
3842
3843void __init set_proc_pid_nlink(void)
3844{
3845 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3846 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3847}