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wlcore: Add RX_BA_WIN_SIZE_CHANGE_EVENT event
[linux/fpc-iii.git] / fs / proc / base.c
blobd2b8c754f627f55b7de6b4af51ef407a869c5276
1 /*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
48 */
49
50 #include <asm/uaccess.h>
51
52 #include <linux/errno.h>
53 #include <linux/time.h>
54 #include <linux/proc_fs.h>
55 #include <linux/stat.h>
56 #include <linux/task_io_accounting_ops.h>
57 #include <linux/init.h>
58 #include <linux/capability.h>
59 #include <linux/file.h>
60 #include <linux/fdtable.h>
61 #include <linux/string.h>
62 #include <linux/seq_file.h>
63 #include <linux/namei.h>
64 #include <linux/mnt_namespace.h>
65 #include <linux/mm.h>
66 #include <linux/swap.h>
67 #include <linux/rcupdate.h>
68 #include <linux/kallsyms.h>
69 #include <linux/stacktrace.h>
70 #include <linux/resource.h>
71 #include <linux/module.h>
72 #include <linux/mount.h>
73 #include <linux/security.h>
74 #include <linux/ptrace.h>
75 #include <linux/tracehook.h>
76 #include <linux/printk.h>
77 #include <linux/cgroup.h>
78 #include <linux/cpuset.h>
79 #include <linux/audit.h>
80 #include <linux/poll.h>
81 #include <linux/nsproxy.h>
82 #include <linux/oom.h>
83 #include <linux/elf.h>
84 #include <linux/pid_namespace.h>
85 #include <linux/user_namespace.h>
86 #include <linux/fs_struct.h>
87 #include <linux/slab.h>
88 #include <linux/flex_array.h>
89 #include <linux/posix-timers.h>
90 #ifdef CONFIG_HARDWALL
91 #include <asm/hardwall.h>
92 #endif
93 #include <trace/events/oom.h>
94 #include "internal.h"
95 #include "fd.h"
96
97 /* NOTE:
98 * Implementing inode permission operations in /proc is almost
99 * certainly an error. Permission checks need to happen during
100 * each system call not at open time. The reason is that most of
101 * what we wish to check for permissions in /proc varies at runtime.
102 *
103 * The classic example of a problem is opening file descriptors
104 * in /proc for a task before it execs a suid executable.
105 */
106
107 struct pid_entry {
108 const char *name;
109 int len;
110 umode_t mode;
111 const struct inode_operations *iop;
112 const struct file_operations *fop;
113 union proc_op op;
114 };
115
116 #define NOD(NAME, MODE, IOP, FOP, OP) { \
117 .name = (NAME), \
118 .len = sizeof(NAME) - 1, \
119 .mode = MODE, \
120 .iop = IOP, \
121 .fop = FOP, \
122 .op = OP, \
123 }
124
125 #define DIR(NAME, MODE, iops, fops) \
126 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
127 #define LNK(NAME, get_link) \
128 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
129 &proc_pid_link_inode_operations, NULL, \
130 { .proc_get_link = get_link } )
131 #define REG(NAME, MODE, fops) \
132 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
133 #define ONE(NAME, MODE, show) \
134 NOD(NAME, (S_IFREG|(MODE)), \
135 NULL, &proc_single_file_operations, \
136 { .proc_show = show } )
137
138 /*
139 * Count the number of hardlinks for the pid_entry table, excluding the .
140 * and .. links.
141 */
142 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
143 unsigned int n)
144 {
145 unsigned int i;
146 unsigned int count;
147
148 count = 0;
149 for (i = 0; i < n; ++i) {
150 if (S_ISDIR(entries[i].mode))
151 ++count;
152 }
153
154 return count;
155 }
156
157 static int get_task_root(struct task_struct *task, struct path *root)
158 {
159 int result = -ENOENT;
160
161 task_lock(task);
162 if (task->fs) {
163 get_fs_root(task->fs, root);
164 result = 0;
165 }
166 task_unlock(task);
167 return result;
168 }
169
170 static int proc_cwd_link(struct dentry *dentry, struct path *path)
171 {
172 struct task_struct *task = get_proc_task(d_inode(dentry));
173 int result = -ENOENT;
174
175 if (task) {
176 task_lock(task);
177 if (task->fs) {
178 get_fs_pwd(task->fs, path);
179 result = 0;
180 }
181 task_unlock(task);
182 put_task_struct(task);
183 }
184 return result;
185 }
186
187 static int proc_root_link(struct dentry *dentry, struct path *path)
188 {
189 struct task_struct *task = get_proc_task(d_inode(dentry));
190 int result = -ENOENT;
191
192 if (task) {
193 result = get_task_root(task, path);
194 put_task_struct(task);
195 }
196 return result;
197 }
198
199 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
200 size_t _count, loff_t *pos)
201 {
202 struct task_struct *tsk;
203 struct mm_struct *mm;
204 char *page;
205 unsigned long count = _count;
206 unsigned long arg_start, arg_end, env_start, env_end;
207 unsigned long len1, len2, len;
208 unsigned long p;
209 char c;
210 ssize_t rv;
211
212 BUG_ON(*pos < 0);
213
214 tsk = get_proc_task(file_inode(file));
215 if (!tsk)
216 return -ESRCH;
217 mm = get_task_mm(tsk);
218 put_task_struct(tsk);
219 if (!mm)
220 return 0;
221 /* Check if process spawned far enough to have cmdline. */
222 if (!mm->env_end) {
223 rv = 0;
224 goto out_mmput;
225 }
226
227 page = (char *)__get_free_page(GFP_TEMPORARY);
228 if (!page) {
229 rv = -ENOMEM;
230 goto out_mmput;
231 }
232
233 down_read(&mm->mmap_sem);
234 arg_start = mm->arg_start;
235 arg_end = mm->arg_end;
236 env_start = mm->env_start;
237 env_end = mm->env_end;
238 up_read(&mm->mmap_sem);
239
240 BUG_ON(arg_start > arg_end);
241 BUG_ON(env_start > env_end);
242
243 len1 = arg_end - arg_start;
244 len2 = env_end - env_start;
245
246 /* Empty ARGV. */
247 if (len1 == 0) {
248 rv = 0;
249 goto out_free_page;
250 }
251 /*
252 * Inherently racy -- command line shares address space
253 * with code and data.
254 */
255 rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0);
256 if (rv <= 0)
257 goto out_free_page;
258
259 rv = 0;
260
261 if (c == '\0') {
262 /* Command line (set of strings) occupies whole ARGV. */
263 if (len1 <= *pos)
264 goto out_free_page;
265
266 p = arg_start + *pos;
267 len = len1 - *pos;
268 while (count > 0 && len > 0) {
269 unsigned int _count;
270 int nr_read;
271
272 _count = min3(count, len, PAGE_SIZE);
273 nr_read = access_remote_vm(mm, p, page, _count, 0);
274 if (nr_read < 0)
275 rv = nr_read;
276 if (nr_read <= 0)
277 goto out_free_page;
278
279 if (copy_to_user(buf, page, nr_read)) {
280 rv = -EFAULT;
281 goto out_free_page;
282 }
283
284 p += nr_read;
285 len -= nr_read;
286 buf += nr_read;
287 count -= nr_read;
288 rv += nr_read;
289 }
290 } else {
291 /*
292 * Command line (1 string) occupies ARGV and maybe
293 * extends into ENVP.
294 */
295 if (len1 + len2 <= *pos)
296 goto skip_argv_envp;
297 if (len1 <= *pos)
298 goto skip_argv;
299
300 p = arg_start + *pos;
301 len = len1 - *pos;
302 while (count > 0 && len > 0) {
303 unsigned int _count, l;
304 int nr_read;
305 bool final;
306
307 _count = min3(count, len, PAGE_SIZE);
308 nr_read = access_remote_vm(mm, p, page, _count, 0);
309 if (nr_read < 0)
310 rv = nr_read;
311 if (nr_read <= 0)
312 goto out_free_page;
313
314 /*
315 * Command line can be shorter than whole ARGV
316 * even if last "marker" byte says it is not.
317 */
318 final = false;
319 l = strnlen(page, nr_read);
320 if (l < nr_read) {
321 nr_read = l;
322 final = true;
323 }
324
325 if (copy_to_user(buf, page, nr_read)) {
326 rv = -EFAULT;
327 goto out_free_page;
328 }
329
330 p += nr_read;
331 len -= nr_read;
332 buf += nr_read;
333 count -= nr_read;
334 rv += nr_read;
335
336 if (final)
337 goto out_free_page;
338 }
339 skip_argv:
340 /*
341 * Command line (1 string) occupies ARGV and
342 * extends into ENVP.
343 */
344 if (len1 <= *pos) {
345 p = env_start + *pos - len1;
346 len = len1 + len2 - *pos;
347 } else {
348 p = env_start;
349 len = len2;
350 }
351 while (count > 0 && len > 0) {
352 unsigned int _count, l;
353 int nr_read;
354 bool final;
355
356 _count = min3(count, len, PAGE_SIZE);
357 nr_read = access_remote_vm(mm, p, page, _count, 0);
358 if (nr_read < 0)
359 rv = nr_read;
360 if (nr_read <= 0)
361 goto out_free_page;
362
363 /* Find EOS. */
364 final = false;
365 l = strnlen(page, nr_read);
366 if (l < nr_read) {
367 nr_read = l;
368 final = true;
369 }
370
371 if (copy_to_user(buf, page, nr_read)) {
372 rv = -EFAULT;
373 goto out_free_page;
374 }
375
376 p += nr_read;
377 len -= nr_read;
378 buf += nr_read;
379 count -= nr_read;
380 rv += nr_read;
381
382 if (final)
383 goto out_free_page;
384 }
385 skip_argv_envp:
386 ;
387 }
388
389 out_free_page:
390 free_page((unsigned long)page);
391 out_mmput:
392 mmput(mm);
393 if (rv > 0)
394 *pos += rv;
395 return rv;
396 }
397
398 static const struct file_operations proc_pid_cmdline_ops = {
399 .read = proc_pid_cmdline_read,
400 .llseek = generic_file_llseek,
401 };
402
403 static int proc_pid_auxv(struct seq_file *m, struct pid_namespace *ns,
404 struct pid *pid, struct task_struct *task)
405 {
406 struct mm_struct *mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
407 if (mm && !IS_ERR(mm)) {
408 unsigned int nwords = 0;
409 do {
410 nwords += 2;
411 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
412 seq_write(m, mm->saved_auxv, nwords * sizeof(mm->saved_auxv[0]));
413 mmput(mm);
414 return 0;
415 } else
416 return PTR_ERR(mm);
417 }
418
419
420 #ifdef CONFIG_KALLSYMS
421 /*
422 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
423 * Returns the resolved symbol. If that fails, simply return the address.
424 */
425 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
426 struct pid *pid, struct task_struct *task)
427 {
428 unsigned long wchan;
429 char symname[KSYM_NAME_LEN];
430
431 wchan = get_wchan(task);
432
433 if (wchan && ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)
434 && !lookup_symbol_name(wchan, symname))
435 seq_printf(m, "%s", symname);
436 else
437 seq_putc(m, '0');
438
439 return 0;
440 }
441 #endif /* CONFIG_KALLSYMS */
442
443 static int lock_trace(struct task_struct *task)
444 {
445 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
446 if (err)
447 return err;
448 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
449 mutex_unlock(&task->signal->cred_guard_mutex);
450 return -EPERM;
451 }
452 return 0;
453 }
454
455 static void unlock_trace(struct task_struct *task)
456 {
457 mutex_unlock(&task->signal->cred_guard_mutex);
458 }
459
460 #ifdef CONFIG_STACKTRACE
461
462 #define MAX_STACK_TRACE_DEPTH 64
463
464 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
465 struct pid *pid, struct task_struct *task)
466 {
467 struct stack_trace trace;
468 unsigned long *entries;
469 int err;
470 int i;
471
472 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
473 if (!entries)
474 return -ENOMEM;
475
476 trace.nr_entries = 0;
477 trace.max_entries = MAX_STACK_TRACE_DEPTH;
478 trace.entries = entries;
479 trace.skip = 0;
480
481 err = lock_trace(task);
482 if (!err) {
483 save_stack_trace_tsk(task, &trace);
484
485 for (i = 0; i < trace.nr_entries; i++) {
486 seq_printf(m, "[<%pK>] %pS\n",
487 (void *)entries[i], (void *)entries[i]);
488 }
489 unlock_trace(task);
490 }
491 kfree(entries);
492
493 return err;
494 }
495 #endif
496
497 #ifdef CONFIG_SCHED_INFO
498 /*
499 * Provides /proc/PID/schedstat
500 */
501 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
502 struct pid *pid, struct task_struct *task)
503 {
504 if (unlikely(!sched_info_on()))
505 seq_printf(m, "0 0 0\n");
506 else
507 seq_printf(m, "%llu %llu %lu\n",
508 (unsigned long long)task->se.sum_exec_runtime,
509 (unsigned long long)task->sched_info.run_delay,
510 task->sched_info.pcount);
511
512 return 0;
513 }
514 #endif
515
516 #ifdef CONFIG_LATENCYTOP
517 static int lstats_show_proc(struct seq_file *m, void *v)
518 {
519 int i;
520 struct inode *inode = m->private;
521 struct task_struct *task = get_proc_task(inode);
522
523 if (!task)
524 return -ESRCH;
525 seq_puts(m, "Latency Top version : v0.1\n");
526 for (i = 0; i < 32; i++) {
527 struct latency_record *lr = &task->latency_record[i];
528 if (lr->backtrace[0]) {
529 int q;
530 seq_printf(m, "%i %li %li",
531 lr->count, lr->time, lr->max);
532 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
533 unsigned long bt = lr->backtrace[q];
534 if (!bt)
535 break;
536 if (bt == ULONG_MAX)
537 break;
538 seq_printf(m, " %ps", (void *)bt);
539 }
540 seq_putc(m, '\n');
541 }
542
543 }
544 put_task_struct(task);
545 return 0;
546 }
547
548 static int lstats_open(struct inode *inode, struct file *file)
549 {
550 return single_open(file, lstats_show_proc, inode);
551 }
552
553 static ssize_t lstats_write(struct file *file, const char __user *buf,
554 size_t count, loff_t *offs)
555 {
556 struct task_struct *task = get_proc_task(file_inode(file));
557
558 if (!task)
559 return -ESRCH;
560 clear_all_latency_tracing(task);
561 put_task_struct(task);
562
563 return count;
564 }
565
566 static const struct file_operations proc_lstats_operations = {
567 .open = lstats_open,
568 .read = seq_read,
569 .write = lstats_write,
570 .llseek = seq_lseek,
571 .release = single_release,
572 };
573
574 #endif
575
576 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
577 struct pid *pid, struct task_struct *task)
578 {
579 unsigned long totalpages = totalram_pages + total_swap_pages;
580 unsigned long points = 0;
581
582 read_lock(&tasklist_lock);
583 if (pid_alive(task))
584 points = oom_badness(task, NULL, NULL, totalpages) *
585 1000 / totalpages;
586 read_unlock(&tasklist_lock);
587 seq_printf(m, "%lu\n", points);
588
589 return 0;
590 }
591
592 struct limit_names {
593 const char *name;
594 const char *unit;
595 };
596
597 static const struct limit_names lnames[RLIM_NLIMITS] = {
598 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
599 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
600 [RLIMIT_DATA] = {"Max data size", "bytes"},
601 [RLIMIT_STACK] = {"Max stack size", "bytes"},
602 [RLIMIT_CORE] = {"Max core file size", "bytes"},
603 [RLIMIT_RSS] = {"Max resident set", "bytes"},
604 [RLIMIT_NPROC] = {"Max processes", "processes"},
605 [RLIMIT_NOFILE] = {"Max open files", "files"},
606 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
607 [RLIMIT_AS] = {"Max address space", "bytes"},
608 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
609 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
610 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
611 [RLIMIT_NICE] = {"Max nice priority", NULL},
612 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
613 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
614 };
615
616 /* Display limits for a process */
617 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
618 struct pid *pid, struct task_struct *task)
619 {
620 unsigned int i;
621 unsigned long flags;
622
623 struct rlimit rlim[RLIM_NLIMITS];
624
625 if (!lock_task_sighand(task, &flags))
626 return 0;
627 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
628 unlock_task_sighand(task, &flags);
629
630 /*
631 * print the file header
632 */
633 seq_printf(m, "%-25s %-20s %-20s %-10s\n",
634 "Limit", "Soft Limit", "Hard Limit", "Units");
635
636 for (i = 0; i < RLIM_NLIMITS; i++) {
637 if (rlim[i].rlim_cur == RLIM_INFINITY)
638 seq_printf(m, "%-25s %-20s ",
639 lnames[i].name, "unlimited");
640 else
641 seq_printf(m, "%-25s %-20lu ",
642 lnames[i].name, rlim[i].rlim_cur);
643
644 if (rlim[i].rlim_max == RLIM_INFINITY)
645 seq_printf(m, "%-20s ", "unlimited");
646 else
647 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
648
649 if (lnames[i].unit)
650 seq_printf(m, "%-10s\n", lnames[i].unit);
651 else
652 seq_putc(m, '\n');
653 }
654
655 return 0;
656 }
657
658 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
659 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
660 struct pid *pid, struct task_struct *task)
661 {
662 long nr;
663 unsigned long args[6], sp, pc;
664 int res;
665
666 res = lock_trace(task);
667 if (res)
668 return res;
669
670 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
671 seq_puts(m, "running\n");
672 else if (nr < 0)
673 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
674 else
675 seq_printf(m,
676 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
677 nr,
678 args[0], args[1], args[2], args[3], args[4], args[5],
679 sp, pc);
680 unlock_trace(task);
681
682 return 0;
683 }
684 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
685
686 /************************************************************************/
687 /* Here the fs part begins */
688 /************************************************************************/
689
690 /* permission checks */
691 static int proc_fd_access_allowed(struct inode *inode)
692 {
693 struct task_struct *task;
694 int allowed = 0;
695 /* Allow access to a task's file descriptors if it is us or we
696 * may use ptrace attach to the process and find out that
697 * information.
698 */
699 task = get_proc_task(inode);
700 if (task) {
701 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
702 put_task_struct(task);
703 }
704 return allowed;
705 }
706
707 int proc_setattr(struct dentry *dentry, struct iattr *attr)
708 {
709 int error;
710 struct inode *inode = d_inode(dentry);
711
712 if (attr->ia_valid & ATTR_MODE)
713 return -EPERM;
714
715 error = inode_change_ok(inode, attr);
716 if (error)
717 return error;
718
719 setattr_copy(inode, attr);
720 mark_inode_dirty(inode);
721 return 0;
722 }
723
724 /*
725 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
726 * or euid/egid (for hide_pid_min=2)?
727 */
728 static bool has_pid_permissions(struct pid_namespace *pid,
729 struct task_struct *task,
730 int hide_pid_min)
731 {
732 if (pid->hide_pid < hide_pid_min)
733 return true;
734 if (in_group_p(pid->pid_gid))
735 return true;
736 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
737 }
738
739
740 static int proc_pid_permission(struct inode *inode, int mask)
741 {
742 struct pid_namespace *pid = inode->i_sb->s_fs_info;
743 struct task_struct *task;
744 bool has_perms;
745
746 task = get_proc_task(inode);
747 if (!task)
748 return -ESRCH;
749 has_perms = has_pid_permissions(pid, task, 1);
750 put_task_struct(task);
751
752 if (!has_perms) {
753 if (pid->hide_pid == 2) {
754 /*
755 * Let's make getdents(), stat(), and open()
756 * consistent with each other. If a process
757 * may not stat() a file, it shouldn't be seen
758 * in procfs at all.
759 */
760 return -ENOENT;
761 }
762
763 return -EPERM;
764 }
765 return generic_permission(inode, mask);
766 }
767
768
769
770 static const struct inode_operations proc_def_inode_operations = {
771 .setattr = proc_setattr,
772 };
773
774 static int proc_single_show(struct seq_file *m, void *v)
775 {
776 struct inode *inode = m->private;
777 struct pid_namespace *ns;
778 struct pid *pid;
779 struct task_struct *task;
780 int ret;
781
782 ns = inode->i_sb->s_fs_info;
783 pid = proc_pid(inode);
784 task = get_pid_task(pid, PIDTYPE_PID);
785 if (!task)
786 return -ESRCH;
787
788 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
789
790 put_task_struct(task);
791 return ret;
792 }
793
794 static int proc_single_open(struct inode *inode, struct file *filp)
795 {
796 return single_open(filp, proc_single_show, inode);
797 }
798
799 static const struct file_operations proc_single_file_operations = {
800 .open = proc_single_open,
801 .read = seq_read,
802 .llseek = seq_lseek,
803 .release = single_release,
804 };
805
806
807 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
808 {
809 struct task_struct *task = get_proc_task(inode);
810 struct mm_struct *mm = ERR_PTR(-ESRCH);
811
812 if (task) {
813 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
814 put_task_struct(task);
815
816 if (!IS_ERR_OR_NULL(mm)) {
817 /* ensure this mm_struct can't be freed */
818 atomic_inc(&mm->mm_count);
819 /* but do not pin its memory */
820 mmput(mm);
821 }
822 }
823
824 return mm;
825 }
826
827 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
828 {
829 struct mm_struct *mm = proc_mem_open(inode, mode);
830
831 if (IS_ERR(mm))
832 return PTR_ERR(mm);
833
834 file->private_data = mm;
835 return 0;
836 }
837
838 static int mem_open(struct inode *inode, struct file *file)
839 {
840 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
841
842 /* OK to pass negative loff_t, we can catch out-of-range */
843 file->f_mode |= FMODE_UNSIGNED_OFFSET;
844
845 return ret;
846 }
847
848 static ssize_t mem_rw(struct file *file, char __user *buf,
849 size_t count, loff_t *ppos, int write)
850 {
851 struct mm_struct *mm = file->private_data;
852 unsigned long addr = *ppos;
853 ssize_t copied;
854 char *page;
855
856 if (!mm)
857 return 0;
858
859 page = (char *)__get_free_page(GFP_TEMPORARY);
860 if (!page)
861 return -ENOMEM;
862
863 copied = 0;
864 if (!atomic_inc_not_zero(&mm->mm_users))
865 goto free;
866
867 while (count > 0) {
868 int this_len = min_t(int, count, PAGE_SIZE);
869
870 if (write && copy_from_user(page, buf, this_len)) {
871 copied = -EFAULT;
872 break;
873 }
874
875 this_len = access_remote_vm(mm, addr, page, this_len, write);
876 if (!this_len) {
877 if (!copied)
878 copied = -EIO;
879 break;
880 }
881
882 if (!write && copy_to_user(buf, page, this_len)) {
883 copied = -EFAULT;
884 break;
885 }
886
887 buf += this_len;
888 addr += this_len;
889 copied += this_len;
890 count -= this_len;
891 }
892 *ppos = addr;
893
894 mmput(mm);
895 free:
896 free_page((unsigned long) page);
897 return copied;
898 }
899
900 static ssize_t mem_read(struct file *file, char __user *buf,
901 size_t count, loff_t *ppos)
902 {
903 return mem_rw(file, buf, count, ppos, 0);
904 }
905
906 static ssize_t mem_write(struct file *file, const char __user *buf,
907 size_t count, loff_t *ppos)
908 {
909 return mem_rw(file, (char __user*)buf, count, ppos, 1);
910 }
911
912 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
913 {
914 switch (orig) {
915 case 0:
916 file->f_pos = offset;
917 break;
918 case 1:
919 file->f_pos += offset;
920 break;
921 default:
922 return -EINVAL;
923 }
924 force_successful_syscall_return();
925 return file->f_pos;
926 }
927
928 static int mem_release(struct inode *inode, struct file *file)
929 {
930 struct mm_struct *mm = file->private_data;
931 if (mm)
932 mmdrop(mm);
933 return 0;
934 }
935
936 static const struct file_operations proc_mem_operations = {
937 .llseek = mem_lseek,
938 .read = mem_read,
939 .write = mem_write,
940 .open = mem_open,
941 .release = mem_release,
942 };
943
944 static int environ_open(struct inode *inode, struct file *file)
945 {
946 return __mem_open(inode, file, PTRACE_MODE_READ);
947 }
948
949 static ssize_t environ_read(struct file *file, char __user *buf,
950 size_t count, loff_t *ppos)
951 {
952 char *page;
953 unsigned long src = *ppos;
954 int ret = 0;
955 struct mm_struct *mm = file->private_data;
956
957 /* Ensure the process spawned far enough to have an environment. */
958 if (!mm || !mm->env_end)
959 return 0;
960
961 page = (char *)__get_free_page(GFP_TEMPORARY);
962 if (!page)
963 return -ENOMEM;
964
965 ret = 0;
966 if (!atomic_inc_not_zero(&mm->mm_users))
967 goto free;
968 while (count > 0) {
969 size_t this_len, max_len;
970 int retval;
971
972 if (src >= (mm->env_end - mm->env_start))
973 break;
974
975 this_len = mm->env_end - (mm->env_start + src);
976
977 max_len = min_t(size_t, PAGE_SIZE, count);
978 this_len = min(max_len, this_len);
979
980 retval = access_remote_vm(mm, (mm->env_start + src),
981 page, this_len, 0);
982
983 if (retval <= 0) {
984 ret = retval;
985 break;
986 }
987
988 if (copy_to_user(buf, page, retval)) {
989 ret = -EFAULT;
990 break;
991 }
992
993 ret += retval;
994 src += retval;
995 buf += retval;
996 count -= retval;
997 }
998 *ppos = src;
999 mmput(mm);
1000
1001 free:
1002 free_page((unsigned long) page);
1003 return ret;
1004 }
1005
1006 static const struct file_operations proc_environ_operations = {
1007 .open = environ_open,
1008 .read = environ_read,
1009 .llseek = generic_file_llseek,
1010 .release = mem_release,
1011 };
1012
1013 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1014 loff_t *ppos)
1015 {
1016 struct task_struct *task = get_proc_task(file_inode(file));
1017 char buffer[PROC_NUMBUF];
1018 int oom_adj = OOM_ADJUST_MIN;
1019 size_t len;
1020 unsigned long flags;
1021
1022 if (!task)
1023 return -ESRCH;
1024 if (lock_task_sighand(task, &flags)) {
1025 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1026 oom_adj = OOM_ADJUST_MAX;
1027 else
1028 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1029 OOM_SCORE_ADJ_MAX;
1030 unlock_task_sighand(task, &flags);
1031 }
1032 put_task_struct(task);
1033 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1034 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1035 }
1036
1037 /*
1038 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1039 * kernels. The effective policy is defined by oom_score_adj, which has a
1040 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1041 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1042 * Processes that become oom disabled via oom_adj will still be oom disabled
1043 * with this implementation.
1044 *
1045 * oom_adj cannot be removed since existing userspace binaries use it.
1046 */
1047 static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1048 size_t count, loff_t *ppos)
1049 {
1050 struct task_struct *task;
1051 char buffer[PROC_NUMBUF];
1052 int oom_adj;
1053 unsigned long flags;
1054 int err;
1055
1056 memset(buffer, 0, sizeof(buffer));
1057 if (count > sizeof(buffer) - 1)
1058 count = sizeof(buffer) - 1;
1059 if (copy_from_user(buffer, buf, count)) {
1060 err = -EFAULT;
1061 goto out;
1062 }
1063
1064 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1065 if (err)
1066 goto out;
1067 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1068 oom_adj != OOM_DISABLE) {
1069 err = -EINVAL;
1070 goto out;
1071 }
1072
1073 task = get_proc_task(file_inode(file));
1074 if (!task) {
1075 err = -ESRCH;
1076 goto out;
1077 }
1078
1079 task_lock(task);
1080 if (!task->mm) {
1081 err = -EINVAL;
1082 goto err_task_lock;
1083 }
1084
1085 if (!lock_task_sighand(task, &flags)) {
1086 err = -ESRCH;
1087 goto err_task_lock;
1088 }
1089
1090 /*
1091 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1092 * value is always attainable.
1093 */
1094 if (oom_adj == OOM_ADJUST_MAX)
1095 oom_adj = OOM_SCORE_ADJ_MAX;
1096 else
1097 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1098
1099 if (oom_adj < task->signal->oom_score_adj &&
1100 !capable(CAP_SYS_RESOURCE)) {
1101 err = -EACCES;
1102 goto err_sighand;
1103 }
1104
1105 /*
1106 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1107 * /proc/pid/oom_score_adj instead.
1108 */
1109 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1110 current->comm, task_pid_nr(current), task_pid_nr(task),
1111 task_pid_nr(task));
1112
1113 task->signal->oom_score_adj = oom_adj;
1114 trace_oom_score_adj_update(task);
1115 err_sighand:
1116 unlock_task_sighand(task, &flags);
1117 err_task_lock:
1118 task_unlock(task);
1119 put_task_struct(task);
1120 out:
1121 return err < 0 ? err : count;
1122 }
1123
1124 static const struct file_operations proc_oom_adj_operations = {
1125 .read = oom_adj_read,
1126 .write = oom_adj_write,
1127 .llseek = generic_file_llseek,
1128 };
1129
1130 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1131 size_t count, loff_t *ppos)
1132 {
1133 struct task_struct *task = get_proc_task(file_inode(file));
1134 char buffer[PROC_NUMBUF];
1135 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1136 unsigned long flags;
1137 size_t len;
1138
1139 if (!task)
1140 return -ESRCH;
1141 if (lock_task_sighand(task, &flags)) {
1142 oom_score_adj = task->signal->oom_score_adj;
1143 unlock_task_sighand(task, &flags);
1144 }
1145 put_task_struct(task);
1146 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1147 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1148 }
1149
1150 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1151 size_t count, loff_t *ppos)
1152 {
1153 struct task_struct *task;
1154 char buffer[PROC_NUMBUF];
1155 unsigned long flags;
1156 int oom_score_adj;
1157 int err;
1158
1159 memset(buffer, 0, sizeof(buffer));
1160 if (count > sizeof(buffer) - 1)
1161 count = sizeof(buffer) - 1;
1162 if (copy_from_user(buffer, buf, count)) {
1163 err = -EFAULT;
1164 goto out;
1165 }
1166
1167 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1168 if (err)
1169 goto out;
1170 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1171 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1172 err = -EINVAL;
1173 goto out;
1174 }
1175
1176 task = get_proc_task(file_inode(file));
1177 if (!task) {
1178 err = -ESRCH;
1179 goto out;
1180 }
1181
1182 task_lock(task);
1183 if (!task->mm) {
1184 err = -EINVAL;
1185 goto err_task_lock;
1186 }
1187
1188 if (!lock_task_sighand(task, &flags)) {
1189 err = -ESRCH;
1190 goto err_task_lock;
1191 }
1192
1193 if ((short)oom_score_adj < task->signal->oom_score_adj_min &&
1194 !capable(CAP_SYS_RESOURCE)) {
1195 err = -EACCES;
1196 goto err_sighand;
1197 }
1198
1199 task->signal->oom_score_adj = (short)oom_score_adj;
1200 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1201 task->signal->oom_score_adj_min = (short)oom_score_adj;
1202 trace_oom_score_adj_update(task);
1203
1204 err_sighand:
1205 unlock_task_sighand(task, &flags);
1206 err_task_lock:
1207 task_unlock(task);
1208 put_task_struct(task);
1209 out:
1210 return err < 0 ? err : count;
1211 }
1212
1213 static const struct file_operations proc_oom_score_adj_operations = {
1214 .read = oom_score_adj_read,
1215 .write = oom_score_adj_write,
1216 .llseek = default_llseek,
1217 };
1218
1219 #ifdef CONFIG_AUDITSYSCALL
1220 #define TMPBUFLEN 21
1221 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1222 size_t count, loff_t *ppos)
1223 {
1224 struct inode * inode = file_inode(file);
1225 struct task_struct *task = get_proc_task(inode);
1226 ssize_t length;
1227 char tmpbuf[TMPBUFLEN];
1228
1229 if (!task)
1230 return -ESRCH;
1231 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1232 from_kuid(file->f_cred->user_ns,
1233 audit_get_loginuid(task)));
1234 put_task_struct(task);
1235 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1236 }
1237
1238 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1239 size_t count, loff_t *ppos)
1240 {
1241 struct inode * inode = file_inode(file);
1242 uid_t loginuid;
1243 kuid_t kloginuid;
1244 int rv;
1245
1246 rcu_read_lock();
1247 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1248 rcu_read_unlock();
1249 return -EPERM;
1250 }
1251 rcu_read_unlock();
1252
1253 if (*ppos != 0) {
1254 /* No partial writes. */
1255 return -EINVAL;
1256 }
1257
1258 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1259 if (rv < 0)
1260 return rv;
1261
1262 /* is userspace tring to explicitly UNSET the loginuid? */
1263 if (loginuid == AUDIT_UID_UNSET) {
1264 kloginuid = INVALID_UID;
1265 } else {
1266 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1267 if (!uid_valid(kloginuid))
1268 return -EINVAL;
1269 }
1270
1271 rv = audit_set_loginuid(kloginuid);
1272 if (rv < 0)
1273 return rv;
1274 return count;
1275 }
1276
1277 static const struct file_operations proc_loginuid_operations = {
1278 .read = proc_loginuid_read,
1279 .write = proc_loginuid_write,
1280 .llseek = generic_file_llseek,
1281 };
1282
1283 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1284 size_t count, loff_t *ppos)
1285 {
1286 struct inode * inode = file_inode(file);
1287 struct task_struct *task = get_proc_task(inode);
1288 ssize_t length;
1289 char tmpbuf[TMPBUFLEN];
1290
1291 if (!task)
1292 return -ESRCH;
1293 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1294 audit_get_sessionid(task));
1295 put_task_struct(task);
1296 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1297 }
1298
1299 static const struct file_operations proc_sessionid_operations = {
1300 .read = proc_sessionid_read,
1301 .llseek = generic_file_llseek,
1302 };
1303 #endif
1304
1305 #ifdef CONFIG_FAULT_INJECTION
1306 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1307 size_t count, loff_t *ppos)
1308 {
1309 struct task_struct *task = get_proc_task(file_inode(file));
1310 char buffer[PROC_NUMBUF];
1311 size_t len;
1312 int make_it_fail;
1313
1314 if (!task)
1315 return -ESRCH;
1316 make_it_fail = task->make_it_fail;
1317 put_task_struct(task);
1318
1319 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1320
1321 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1322 }
1323
1324 static ssize_t proc_fault_inject_write(struct file * file,
1325 const char __user * buf, size_t count, loff_t *ppos)
1326 {
1327 struct task_struct *task;
1328 char buffer[PROC_NUMBUF];
1329 int make_it_fail;
1330 int rv;
1331
1332 if (!capable(CAP_SYS_RESOURCE))
1333 return -EPERM;
1334 memset(buffer, 0, sizeof(buffer));
1335 if (count > sizeof(buffer) - 1)
1336 count = sizeof(buffer) - 1;
1337 if (copy_from_user(buffer, buf, count))
1338 return -EFAULT;
1339 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1340 if (rv < 0)
1341 return rv;
1342 if (make_it_fail < 0 || make_it_fail > 1)
1343 return -EINVAL;
1344
1345 task = get_proc_task(file_inode(file));
1346 if (!task)
1347 return -ESRCH;
1348 task->make_it_fail = make_it_fail;
1349 put_task_struct(task);
1350
1351 return count;
1352 }
1353
1354 static const struct file_operations proc_fault_inject_operations = {
1355 .read = proc_fault_inject_read,
1356 .write = proc_fault_inject_write,
1357 .llseek = generic_file_llseek,
1358 };
1359 #endif
1360
1361
1362 #ifdef CONFIG_SCHED_DEBUG
1363 /*
1364 * Print out various scheduling related per-task fields:
1365 */
1366 static int sched_show(struct seq_file *m, void *v)
1367 {
1368 struct inode *inode = m->private;
1369 struct task_struct *p;
1370
1371 p = get_proc_task(inode);
1372 if (!p)
1373 return -ESRCH;
1374 proc_sched_show_task(p, m);
1375
1376 put_task_struct(p);
1377
1378 return 0;
1379 }
1380
1381 static ssize_t
1382 sched_write(struct file *file, const char __user *buf,
1383 size_t count, loff_t *offset)
1384 {
1385 struct inode *inode = file_inode(file);
1386 struct task_struct *p;
1387
1388 p = get_proc_task(inode);
1389 if (!p)
1390 return -ESRCH;
1391 proc_sched_set_task(p);
1392
1393 put_task_struct(p);
1394
1395 return count;
1396 }
1397
1398 static int sched_open(struct inode *inode, struct file *filp)
1399 {
1400 return single_open(filp, sched_show, inode);
1401 }
1402
1403 static const struct file_operations proc_pid_sched_operations = {
1404 .open = sched_open,
1405 .read = seq_read,
1406 .write = sched_write,
1407 .llseek = seq_lseek,
1408 .release = single_release,
1409 };
1410
1411 #endif
1412
1413 #ifdef CONFIG_SCHED_AUTOGROUP
1414 /*
1415 * Print out autogroup related information:
1416 */
1417 static int sched_autogroup_show(struct seq_file *m, void *v)
1418 {
1419 struct inode *inode = m->private;
1420 struct task_struct *p;
1421
1422 p = get_proc_task(inode);
1423 if (!p)
1424 return -ESRCH;
1425 proc_sched_autogroup_show_task(p, m);
1426
1427 put_task_struct(p);
1428
1429 return 0;
1430 }
1431
1432 static ssize_t
1433 sched_autogroup_write(struct file *file, const char __user *buf,
1434 size_t count, loff_t *offset)
1435 {
1436 struct inode *inode = file_inode(file);
1437 struct task_struct *p;
1438 char buffer[PROC_NUMBUF];
1439 int nice;
1440 int err;
1441
1442 memset(buffer, 0, sizeof(buffer));
1443 if (count > sizeof(buffer) - 1)
1444 count = sizeof(buffer) - 1;
1445 if (copy_from_user(buffer, buf, count))
1446 return -EFAULT;
1447
1448 err = kstrtoint(strstrip(buffer), 0, &nice);
1449 if (err < 0)
1450 return err;
1451
1452 p = get_proc_task(inode);
1453 if (!p)
1454 return -ESRCH;
1455
1456 err = proc_sched_autogroup_set_nice(p, nice);
1457 if (err)
1458 count = err;
1459
1460 put_task_struct(p);
1461
1462 return count;
1463 }
1464
1465 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1466 {
1467 int ret;
1468
1469 ret = single_open(filp, sched_autogroup_show, NULL);
1470 if (!ret) {
1471 struct seq_file *m = filp->private_data;
1472
1473 m->private = inode;
1474 }
1475 return ret;
1476 }
1477
1478 static const struct file_operations proc_pid_sched_autogroup_operations = {
1479 .open = sched_autogroup_open,
1480 .read = seq_read,
1481 .write = sched_autogroup_write,
1482 .llseek = seq_lseek,
1483 .release = single_release,
1484 };
1485
1486 #endif /* CONFIG_SCHED_AUTOGROUP */
1487
1488 static ssize_t comm_write(struct file *file, const char __user *buf,
1489 size_t count, loff_t *offset)
1490 {
1491 struct inode *inode = file_inode(file);
1492 struct task_struct *p;
1493 char buffer[TASK_COMM_LEN];
1494 const size_t maxlen = sizeof(buffer) - 1;
1495
1496 memset(buffer, 0, sizeof(buffer));
1497 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1498 return -EFAULT;
1499
1500 p = get_proc_task(inode);
1501 if (!p)
1502 return -ESRCH;
1503
1504 if (same_thread_group(current, p))
1505 set_task_comm(p, buffer);
1506 else
1507 count = -EINVAL;
1508
1509 put_task_struct(p);
1510
1511 return count;
1512 }
1513
1514 static int comm_show(struct seq_file *m, void *v)
1515 {
1516 struct inode *inode = m->private;
1517 struct task_struct *p;
1518
1519 p = get_proc_task(inode);
1520 if (!p)
1521 return -ESRCH;
1522
1523 task_lock(p);
1524 seq_printf(m, "%s\n", p->comm);
1525 task_unlock(p);
1526
1527 put_task_struct(p);
1528
1529 return 0;
1530 }
1531
1532 static int comm_open(struct inode *inode, struct file *filp)
1533 {
1534 return single_open(filp, comm_show, inode);
1535 }
1536
1537 static const struct file_operations proc_pid_set_comm_operations = {
1538 .open = comm_open,
1539 .read = seq_read,
1540 .write = comm_write,
1541 .llseek = seq_lseek,
1542 .release = single_release,
1543 };
1544
1545 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1546 {
1547 struct task_struct *task;
1548 struct file *exe_file;
1549
1550 task = get_proc_task(d_inode(dentry));
1551 if (!task)
1552 return -ENOENT;
1553 exe_file = get_task_exe_file(task);
1554 put_task_struct(task);
1555 if (exe_file) {
1556 *exe_path = exe_file->f_path;
1557 path_get(&exe_file->f_path);
1558 fput(exe_file);
1559 return 0;
1560 } else
1561 return -ENOENT;
1562 }
1563
1564 static const char *proc_pid_follow_link(struct dentry *dentry, void **cookie)
1565 {
1566 struct inode *inode = d_inode(dentry);
1567 struct path path;
1568 int error = -EACCES;
1569
1570 /* Are we allowed to snoop on the tasks file descriptors? */
1571 if (!proc_fd_access_allowed(inode))
1572 goto out;
1573
1574 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1575 if (error)
1576 goto out;
1577
1578 nd_jump_link(&path);
1579 return NULL;
1580 out:
1581 return ERR_PTR(error);
1582 }
1583
1584 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1585 {
1586 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1587 char *pathname;
1588 int len;
1589
1590 if (!tmp)
1591 return -ENOMEM;
1592
1593 pathname = d_path(path, tmp, PAGE_SIZE);
1594 len = PTR_ERR(pathname);
1595 if (IS_ERR(pathname))
1596 goto out;
1597 len = tmp + PAGE_SIZE - 1 - pathname;
1598
1599 if (len > buflen)
1600 len = buflen;
1601 if (copy_to_user(buffer, pathname, len))
1602 len = -EFAULT;
1603 out:
1604 free_page((unsigned long)tmp);
1605 return len;
1606 }
1607
1608 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1609 {
1610 int error = -EACCES;
1611 struct inode *inode = d_inode(dentry);
1612 struct path path;
1613
1614 /* Are we allowed to snoop on the tasks file descriptors? */
1615 if (!proc_fd_access_allowed(inode))
1616 goto out;
1617
1618 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1619 if (error)
1620 goto out;
1621
1622 error = do_proc_readlink(&path, buffer, buflen);
1623 path_put(&path);
1624 out:
1625 return error;
1626 }
1627
1628 const struct inode_operations proc_pid_link_inode_operations = {
1629 .readlink = proc_pid_readlink,
1630 .follow_link = proc_pid_follow_link,
1631 .setattr = proc_setattr,
1632 };
1633
1634
1635 /* building an inode */
1636
1637 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1638 {
1639 struct inode * inode;
1640 struct proc_inode *ei;
1641 const struct cred *cred;
1642
1643 /* We need a new inode */
1644
1645 inode = new_inode(sb);
1646 if (!inode)
1647 goto out;
1648
1649 /* Common stuff */
1650 ei = PROC_I(inode);
1651 inode->i_ino = get_next_ino();
1652 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1653 inode->i_op = &proc_def_inode_operations;
1654
1655 /*
1656 * grab the reference to task.
1657 */
1658 ei->pid = get_task_pid(task, PIDTYPE_PID);
1659 if (!ei->pid)
1660 goto out_unlock;
1661
1662 if (task_dumpable(task)) {
1663 rcu_read_lock();
1664 cred = __task_cred(task);
1665 inode->i_uid = cred->euid;
1666 inode->i_gid = cred->egid;
1667 rcu_read_unlock();
1668 }
1669 security_task_to_inode(task, inode);
1670
1671 out:
1672 return inode;
1673
1674 out_unlock:
1675 iput(inode);
1676 return NULL;
1677 }
1678
1679 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1680 {
1681 struct inode *inode = d_inode(dentry);
1682 struct task_struct *task;
1683 const struct cred *cred;
1684 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
1685
1686 generic_fillattr(inode, stat);
1687
1688 rcu_read_lock();
1689 stat->uid = GLOBAL_ROOT_UID;
1690 stat->gid = GLOBAL_ROOT_GID;
1691 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1692 if (task) {
1693 if (!has_pid_permissions(pid, task, 2)) {
1694 rcu_read_unlock();
1695 /*
1696 * This doesn't prevent learning whether PID exists,
1697 * it only makes getattr() consistent with readdir().
1698 */
1699 return -ENOENT;
1700 }
1701 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1702 task_dumpable(task)) {
1703 cred = __task_cred(task);
1704 stat->uid = cred->euid;
1705 stat->gid = cred->egid;
1706 }
1707 }
1708 rcu_read_unlock();
1709 return 0;
1710 }
1711
1712 /* dentry stuff */
1713
1714 /*
1715 * Exceptional case: normally we are not allowed to unhash a busy
1716 * directory. In this case, however, we can do it - no aliasing problems
1717 * due to the way we treat inodes.
1718 *
1719 * Rewrite the inode's ownerships here because the owning task may have
1720 * performed a setuid(), etc.
1721 *
1722 * Before the /proc/pid/status file was created the only way to read
1723 * the effective uid of a /process was to stat /proc/pid. Reading
1724 * /proc/pid/status is slow enough that procps and other packages
1725 * kept stating /proc/pid. To keep the rules in /proc simple I have
1726 * made this apply to all per process world readable and executable
1727 * directories.
1728 */
1729 int pid_revalidate(struct dentry *dentry, unsigned int flags)
1730 {
1731 struct inode *inode;
1732 struct task_struct *task;
1733 const struct cred *cred;
1734
1735 if (flags & LOOKUP_RCU)
1736 return -ECHILD;
1737
1738 inode = d_inode(dentry);
1739 task = get_proc_task(inode);
1740
1741 if (task) {
1742 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1743 task_dumpable(task)) {
1744 rcu_read_lock();
1745 cred = __task_cred(task);
1746 inode->i_uid = cred->euid;
1747 inode->i_gid = cred->egid;
1748 rcu_read_unlock();
1749 } else {
1750 inode->i_uid = GLOBAL_ROOT_UID;
1751 inode->i_gid = GLOBAL_ROOT_GID;
1752 }
1753 inode->i_mode &= ~(S_ISUID | S_ISGID);
1754 security_task_to_inode(task, inode);
1755 put_task_struct(task);
1756 return 1;
1757 }
1758 return 0;
1759 }
1760
1761 static inline bool proc_inode_is_dead(struct inode *inode)
1762 {
1763 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1764 }
1765
1766 int pid_delete_dentry(const struct dentry *dentry)
1767 {
1768 /* Is the task we represent dead?
1769 * If so, then don't put the dentry on the lru list,
1770 * kill it immediately.
1771 */
1772 return proc_inode_is_dead(d_inode(dentry));
1773 }
1774
1775 const struct dentry_operations pid_dentry_operations =
1776 {
1777 .d_revalidate = pid_revalidate,
1778 .d_delete = pid_delete_dentry,
1779 };
1780
1781 /* Lookups */
1782
1783 /*
1784 * Fill a directory entry.
1785 *
1786 * If possible create the dcache entry and derive our inode number and
1787 * file type from dcache entry.
1788 *
1789 * Since all of the proc inode numbers are dynamically generated, the inode
1790 * numbers do not exist until the inode is cache. This means creating the
1791 * the dcache entry in readdir is necessary to keep the inode numbers
1792 * reported by readdir in sync with the inode numbers reported
1793 * by stat.
1794 */
1795 bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1796 const char *name, int len,
1797 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1798 {
1799 struct dentry *child, *dir = file->f_path.dentry;
1800 struct qstr qname = QSTR_INIT(name, len);
1801 struct inode *inode;
1802 unsigned type;
1803 ino_t ino;
1804
1805 child = d_hash_and_lookup(dir, &qname);
1806 if (!child) {
1807 child = d_alloc(dir, &qname);
1808 if (!child)
1809 goto end_instantiate;
1810 if (instantiate(d_inode(dir), child, task, ptr) < 0) {
1811 dput(child);
1812 goto end_instantiate;
1813 }
1814 }
1815 inode = d_inode(child);
1816 ino = inode->i_ino;
1817 type = inode->i_mode >> 12;
1818 dput(child);
1819 return dir_emit(ctx, name, len, ino, type);
1820
1821 end_instantiate:
1822 return dir_emit(ctx, name, len, 1, DT_UNKNOWN);
1823 }
1824
1825 /*
1826 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1827 * which represent vma start and end addresses.
1828 */
1829 static int dname_to_vma_addr(struct dentry *dentry,
1830 unsigned long *start, unsigned long *end)
1831 {
1832 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
1833 return -EINVAL;
1834
1835 return 0;
1836 }
1837
1838 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1839 {
1840 unsigned long vm_start, vm_end;
1841 bool exact_vma_exists = false;
1842 struct mm_struct *mm = NULL;
1843 struct task_struct *task;
1844 const struct cred *cred;
1845 struct inode *inode;
1846 int status = 0;
1847
1848 if (flags & LOOKUP_RCU)
1849 return -ECHILD;
1850
1851 inode = d_inode(dentry);
1852 task = get_proc_task(inode);
1853 if (!task)
1854 goto out_notask;
1855
1856 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
1857 if (IS_ERR_OR_NULL(mm))
1858 goto out;
1859
1860 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1861 down_read(&mm->mmap_sem);
1862 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1863 up_read(&mm->mmap_sem);
1864 }
1865
1866 mmput(mm);
1867
1868 if (exact_vma_exists) {
1869 if (task_dumpable(task)) {
1870 rcu_read_lock();
1871 cred = __task_cred(task);
1872 inode->i_uid = cred->euid;
1873 inode->i_gid = cred->egid;
1874 rcu_read_unlock();
1875 } else {
1876 inode->i_uid = GLOBAL_ROOT_UID;
1877 inode->i_gid = GLOBAL_ROOT_GID;
1878 }
1879 security_task_to_inode(task, inode);
1880 status = 1;
1881 }
1882
1883 out:
1884 put_task_struct(task);
1885
1886 out_notask:
1887 return status;
1888 }
1889
1890 static const struct dentry_operations tid_map_files_dentry_operations = {
1891 .d_revalidate = map_files_d_revalidate,
1892 .d_delete = pid_delete_dentry,
1893 };
1894
1895 static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
1896 {
1897 unsigned long vm_start, vm_end;
1898 struct vm_area_struct *vma;
1899 struct task_struct *task;
1900 struct mm_struct *mm;
1901 int rc;
1902
1903 rc = -ENOENT;
1904 task = get_proc_task(d_inode(dentry));
1905 if (!task)
1906 goto out;
1907
1908 mm = get_task_mm(task);
1909 put_task_struct(task);
1910 if (!mm)
1911 goto out;
1912
1913 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
1914 if (rc)
1915 goto out_mmput;
1916
1917 rc = -ENOENT;
1918 down_read(&mm->mmap_sem);
1919 vma = find_exact_vma(mm, vm_start, vm_end);
1920 if (vma && vma->vm_file) {
1921 *path = vma->vm_file->f_path;
1922 path_get(path);
1923 rc = 0;
1924 }
1925 up_read(&mm->mmap_sem);
1926
1927 out_mmput:
1928 mmput(mm);
1929 out:
1930 return rc;
1931 }
1932
1933 struct map_files_info {
1934 fmode_t mode;
1935 unsigned long len;
1936 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
1937 };
1938
1939 /*
1940 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
1941 * symlinks may be used to bypass permissions on ancestor directories in the
1942 * path to the file in question.
1943 */
1944 static const char *
1945 proc_map_files_follow_link(struct dentry *dentry, void **cookie)
1946 {
1947 if (!capable(CAP_SYS_ADMIN))
1948 return ERR_PTR(-EPERM);
1949
1950 return proc_pid_follow_link(dentry, NULL);
1951 }
1952
1953 /*
1954 * Identical to proc_pid_link_inode_operations except for follow_link()
1955 */
1956 static const struct inode_operations proc_map_files_link_inode_operations = {
1957 .readlink = proc_pid_readlink,
1958 .follow_link = proc_map_files_follow_link,
1959 .setattr = proc_setattr,
1960 };
1961
1962 static int
1963 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
1964 struct task_struct *task, const void *ptr)
1965 {
1966 fmode_t mode = (fmode_t)(unsigned long)ptr;
1967 struct proc_inode *ei;
1968 struct inode *inode;
1969
1970 inode = proc_pid_make_inode(dir->i_sb, task);
1971 if (!inode)
1972 return -ENOENT;
1973
1974 ei = PROC_I(inode);
1975 ei->op.proc_get_link = proc_map_files_get_link;
1976
1977 inode->i_op = &proc_map_files_link_inode_operations;
1978 inode->i_size = 64;
1979 inode->i_mode = S_IFLNK;
1980
1981 if (mode & FMODE_READ)
1982 inode->i_mode |= S_IRUSR;
1983 if (mode & FMODE_WRITE)
1984 inode->i_mode |= S_IWUSR;
1985
1986 d_set_d_op(dentry, &tid_map_files_dentry_operations);
1987 d_add(dentry, inode);
1988
1989 return 0;
1990 }
1991
1992 static struct dentry *proc_map_files_lookup(struct inode *dir,
1993 struct dentry *dentry, unsigned int flags)
1994 {
1995 unsigned long vm_start, vm_end;
1996 struct vm_area_struct *vma;
1997 struct task_struct *task;
1998 int result;
1999 struct mm_struct *mm;
2000
2001 result = -ENOENT;
2002 task = get_proc_task(dir);
2003 if (!task)
2004 goto out;
2005
2006 result = -EACCES;
2007 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2008 goto out_put_task;
2009
2010 result = -ENOENT;
2011 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2012 goto out_put_task;
2013
2014 mm = get_task_mm(task);
2015 if (!mm)
2016 goto out_put_task;
2017
2018 down_read(&mm->mmap_sem);
2019 vma = find_exact_vma(mm, vm_start, vm_end);
2020 if (!vma)
2021 goto out_no_vma;
2022
2023 if (vma->vm_file)
2024 result = proc_map_files_instantiate(dir, dentry, task,
2025 (void *)(unsigned long)vma->vm_file->f_mode);
2026
2027 out_no_vma:
2028 up_read(&mm->mmap_sem);
2029 mmput(mm);
2030 out_put_task:
2031 put_task_struct(task);
2032 out:
2033 return ERR_PTR(result);
2034 }
2035
2036 static const struct inode_operations proc_map_files_inode_operations = {
2037 .lookup = proc_map_files_lookup,
2038 .permission = proc_fd_permission,
2039 .setattr = proc_setattr,
2040 };
2041
2042 static int
2043 proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2044 {
2045 struct vm_area_struct *vma;
2046 struct task_struct *task;
2047 struct mm_struct *mm;
2048 unsigned long nr_files, pos, i;
2049 struct flex_array *fa = NULL;
2050 struct map_files_info info;
2051 struct map_files_info *p;
2052 int ret;
2053
2054 ret = -ENOENT;
2055 task = get_proc_task(file_inode(file));
2056 if (!task)
2057 goto out;
2058
2059 ret = -EACCES;
2060 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2061 goto out_put_task;
2062
2063 ret = 0;
2064 if (!dir_emit_dots(file, ctx))
2065 goto out_put_task;
2066
2067 mm = get_task_mm(task);
2068 if (!mm)
2069 goto out_put_task;
2070 down_read(&mm->mmap_sem);
2071
2072 nr_files = 0;
2073
2074 /*
2075 * We need two passes here:
2076 *
2077 * 1) Collect vmas of mapped files with mmap_sem taken
2078 * 2) Release mmap_sem and instantiate entries
2079 *
2080 * otherwise we get lockdep complained, since filldir()
2081 * routine might require mmap_sem taken in might_fault().
2082 */
2083
2084 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2085 if (vma->vm_file && ++pos > ctx->pos)
2086 nr_files++;
2087 }
2088
2089 if (nr_files) {
2090 fa = flex_array_alloc(sizeof(info), nr_files,
2091 GFP_KERNEL);
2092 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2093 GFP_KERNEL)) {
2094 ret = -ENOMEM;
2095 if (fa)
2096 flex_array_free(fa);
2097 up_read(&mm->mmap_sem);
2098 mmput(mm);
2099 goto out_put_task;
2100 }
2101 for (i = 0, vma = mm->mmap, pos = 2; vma;
2102 vma = vma->vm_next) {
2103 if (!vma->vm_file)
2104 continue;
2105 if (++pos <= ctx->pos)
2106 continue;
2107
2108 info.mode = vma->vm_file->f_mode;
2109 info.len = snprintf(info.name,
2110 sizeof(info.name), "%lx-%lx",
2111 vma->vm_start, vma->vm_end);
2112 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2113 BUG();
2114 }
2115 }
2116 up_read(&mm->mmap_sem);
2117
2118 for (i = 0; i < nr_files; i++) {
2119 p = flex_array_get(fa, i);
2120 if (!proc_fill_cache(file, ctx,
2121 p->name, p->len,
2122 proc_map_files_instantiate,
2123 task,
2124 (void *)(unsigned long)p->mode))
2125 break;
2126 ctx->pos++;
2127 }
2128 if (fa)
2129 flex_array_free(fa);
2130 mmput(mm);
2131
2132 out_put_task:
2133 put_task_struct(task);
2134 out:
2135 return ret;
2136 }
2137
2138 static const struct file_operations proc_map_files_operations = {
2139 .read = generic_read_dir,
2140 .iterate = proc_map_files_readdir,
2141 .llseek = default_llseek,
2142 };
2143
2144 struct timers_private {
2145 struct pid *pid;
2146 struct task_struct *task;
2147 struct sighand_struct *sighand;
2148 struct pid_namespace *ns;
2149 unsigned long flags;
2150 };
2151
2152 static void *timers_start(struct seq_file *m, loff_t *pos)
2153 {
2154 struct timers_private *tp = m->private;
2155
2156 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2157 if (!tp->task)
2158 return ERR_PTR(-ESRCH);
2159
2160 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2161 if (!tp->sighand)
2162 return ERR_PTR(-ESRCH);
2163
2164 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2165 }
2166
2167 static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2168 {
2169 struct timers_private *tp = m->private;
2170 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2171 }
2172
2173 static void timers_stop(struct seq_file *m, void *v)
2174 {
2175 struct timers_private *tp = m->private;
2176
2177 if (tp->sighand) {
2178 unlock_task_sighand(tp->task, &tp->flags);
2179 tp->sighand = NULL;
2180 }
2181
2182 if (tp->task) {
2183 put_task_struct(tp->task);
2184 tp->task = NULL;
2185 }
2186 }
2187
2188 static int show_timer(struct seq_file *m, void *v)
2189 {
2190 struct k_itimer *timer;
2191 struct timers_private *tp = m->private;
2192 int notify;
2193 static const char * const nstr[] = {
2194 [SIGEV_SIGNAL] = "signal",
2195 [SIGEV_NONE] = "none",
2196 [SIGEV_THREAD] = "thread",
2197 };
2198
2199 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2200 notify = timer->it_sigev_notify;
2201
2202 seq_printf(m, "ID: %d\n", timer->it_id);
2203 seq_printf(m, "signal: %d/%p\n",
2204 timer->sigq->info.si_signo,
2205 timer->sigq->info.si_value.sival_ptr);
2206 seq_printf(m, "notify: %s/%s.%d\n",
2207 nstr[notify & ~SIGEV_THREAD_ID],
2208 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2209 pid_nr_ns(timer->it_pid, tp->ns));
2210 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2211
2212 return 0;
2213 }
2214
2215 static const struct seq_operations proc_timers_seq_ops = {
2216 .start = timers_start,
2217 .next = timers_next,
2218 .stop = timers_stop,
2219 .show = show_timer,
2220 };
2221
2222 static int proc_timers_open(struct inode *inode, struct file *file)
2223 {
2224 struct timers_private *tp;
2225
2226 tp = __seq_open_private(file, &proc_timers_seq_ops,
2227 sizeof(struct timers_private));
2228 if (!tp)
2229 return -ENOMEM;
2230
2231 tp->pid = proc_pid(inode);
2232 tp->ns = inode->i_sb->s_fs_info;
2233 return 0;
2234 }
2235
2236 static const struct file_operations proc_timers_operations = {
2237 .open = proc_timers_open,
2238 .read = seq_read,
2239 .llseek = seq_lseek,
2240 .release = seq_release_private,
2241 };
2242
2243 static int proc_pident_instantiate(struct inode *dir,
2244 struct dentry *dentry, struct task_struct *task, const void *ptr)
2245 {
2246 const struct pid_entry *p = ptr;
2247 struct inode *inode;
2248 struct proc_inode *ei;
2249
2250 inode = proc_pid_make_inode(dir->i_sb, task);
2251 if (!inode)
2252 goto out;
2253
2254 ei = PROC_I(inode);
2255 inode->i_mode = p->mode;
2256 if (S_ISDIR(inode->i_mode))
2257 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2258 if (p->iop)
2259 inode->i_op = p->iop;
2260 if (p->fop)
2261 inode->i_fop = p->fop;
2262 ei->op = p->op;
2263 d_set_d_op(dentry, &pid_dentry_operations);
2264 d_add(dentry, inode);
2265 /* Close the race of the process dying before we return the dentry */
2266 if (pid_revalidate(dentry, 0))
2267 return 0;
2268 out:
2269 return -ENOENT;
2270 }
2271
2272 static struct dentry *proc_pident_lookup(struct inode *dir,
2273 struct dentry *dentry,
2274 const struct pid_entry *ents,
2275 unsigned int nents)
2276 {
2277 int error;
2278 struct task_struct *task = get_proc_task(dir);
2279 const struct pid_entry *p, *last;
2280
2281 error = -ENOENT;
2282
2283 if (!task)
2284 goto out_no_task;
2285
2286 /*
2287 * Yes, it does not scale. And it should not. Don't add
2288 * new entries into /proc/<tgid>/ without very good reasons.
2289 */
2290 last = &ents[nents - 1];
2291 for (p = ents; p <= last; p++) {
2292 if (p->len != dentry->d_name.len)
2293 continue;
2294 if (!memcmp(dentry->d_name.name, p->name, p->len))
2295 break;
2296 }
2297 if (p > last)
2298 goto out;
2299
2300 error = proc_pident_instantiate(dir, dentry, task, p);
2301 out:
2302 put_task_struct(task);
2303 out_no_task:
2304 return ERR_PTR(error);
2305 }
2306
2307 static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2308 const struct pid_entry *ents, unsigned int nents)
2309 {
2310 struct task_struct *task = get_proc_task(file_inode(file));
2311 const struct pid_entry *p;
2312
2313 if (!task)
2314 return -ENOENT;
2315
2316 if (!dir_emit_dots(file, ctx))
2317 goto out;
2318
2319 if (ctx->pos >= nents + 2)
2320 goto out;
2321
2322 for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) {
2323 if (!proc_fill_cache(file, ctx, p->name, p->len,
2324 proc_pident_instantiate, task, p))
2325 break;
2326 ctx->pos++;
2327 }
2328 out:
2329 put_task_struct(task);
2330 return 0;
2331 }
2332
2333 #ifdef CONFIG_SECURITY
2334 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2335 size_t count, loff_t *ppos)
2336 {
2337 struct inode * inode = file_inode(file);
2338 char *p = NULL;
2339 ssize_t length;
2340 struct task_struct *task = get_proc_task(inode);
2341
2342 if (!task)
2343 return -ESRCH;
2344
2345 length = security_getprocattr(task,
2346 (char*)file->f_path.dentry->d_name.name,
2347 &p);
2348 put_task_struct(task);
2349 if (length > 0)
2350 length = simple_read_from_buffer(buf, count, ppos, p, length);
2351 kfree(p);
2352 return length;
2353 }
2354
2355 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2356 size_t count, loff_t *ppos)
2357 {
2358 struct inode * inode = file_inode(file);
2359 char *page;
2360 ssize_t length;
2361 struct task_struct *task = get_proc_task(inode);
2362
2363 length = -ESRCH;
2364 if (!task)
2365 goto out_no_task;
2366 if (count > PAGE_SIZE)
2367 count = PAGE_SIZE;
2368
2369 /* No partial writes. */
2370 length = -EINVAL;
2371 if (*ppos != 0)
2372 goto out;
2373
2374 length = -ENOMEM;
2375 page = (char*)__get_free_page(GFP_TEMPORARY);
2376 if (!page)
2377 goto out;
2378
2379 length = -EFAULT;
2380 if (copy_from_user(page, buf, count))
2381 goto out_free;
2382
2383 /* Guard against adverse ptrace interaction */
2384 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2385 if (length < 0)
2386 goto out_free;
2387
2388 length = security_setprocattr(task,
2389 (char*)file->f_path.dentry->d_name.name,
2390 (void*)page, count);
2391 mutex_unlock(&task->signal->cred_guard_mutex);
2392 out_free:
2393 free_page((unsigned long) page);
2394 out:
2395 put_task_struct(task);
2396 out_no_task:
2397 return length;
2398 }
2399
2400 static const struct file_operations proc_pid_attr_operations = {
2401 .read = proc_pid_attr_read,
2402 .write = proc_pid_attr_write,
2403 .llseek = generic_file_llseek,
2404 };
2405
2406 static const struct pid_entry attr_dir_stuff[] = {
2407 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2408 REG("prev", S_IRUGO, proc_pid_attr_operations),
2409 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2410 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2411 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2412 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2413 };
2414
2415 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2416 {
2417 return proc_pident_readdir(file, ctx,
2418 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2419 }
2420
2421 static const struct file_operations proc_attr_dir_operations = {
2422 .read = generic_read_dir,
2423 .iterate = proc_attr_dir_readdir,
2424 .llseek = default_llseek,
2425 };
2426
2427 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2428 struct dentry *dentry, unsigned int flags)
2429 {
2430 return proc_pident_lookup(dir, dentry,
2431 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2432 }
2433
2434 static const struct inode_operations proc_attr_dir_inode_operations = {
2435 .lookup = proc_attr_dir_lookup,
2436 .getattr = pid_getattr,
2437 .setattr = proc_setattr,
2438 };
2439
2440 #endif
2441
2442 #ifdef CONFIG_ELF_CORE
2443 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2444 size_t count, loff_t *ppos)
2445 {
2446 struct task_struct *task = get_proc_task(file_inode(file));
2447 struct mm_struct *mm;
2448 char buffer[PROC_NUMBUF];
2449 size_t len;
2450 int ret;
2451
2452 if (!task)
2453 return -ESRCH;
2454
2455 ret = 0;
2456 mm = get_task_mm(task);
2457 if (mm) {
2458 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2459 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2460 MMF_DUMP_FILTER_SHIFT));
2461 mmput(mm);
2462 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2463 }
2464
2465 put_task_struct(task);
2466
2467 return ret;
2468 }
2469
2470 static ssize_t proc_coredump_filter_write(struct file *file,
2471 const char __user *buf,
2472 size_t count,
2473 loff_t *ppos)
2474 {
2475 struct task_struct *task;
2476 struct mm_struct *mm;
2477 unsigned int val;
2478 int ret;
2479 int i;
2480 unsigned long mask;
2481
2482 ret = kstrtouint_from_user(buf, count, 0, &val);
2483 if (ret < 0)
2484 return ret;
2485
2486 ret = -ESRCH;
2487 task = get_proc_task(file_inode(file));
2488 if (!task)
2489 goto out_no_task;
2490
2491 mm = get_task_mm(task);
2492 if (!mm)
2493 goto out_no_mm;
2494 ret = 0;
2495
2496 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2497 if (val & mask)
2498 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2499 else
2500 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2501 }
2502
2503 mmput(mm);
2504 out_no_mm:
2505 put_task_struct(task);
2506 out_no_task:
2507 if (ret < 0)
2508 return ret;
2509 return count;
2510 }
2511
2512 static const struct file_operations proc_coredump_filter_operations = {
2513 .read = proc_coredump_filter_read,
2514 .write = proc_coredump_filter_write,
2515 .llseek = generic_file_llseek,
2516 };
2517 #endif
2518
2519 #ifdef CONFIG_TASK_IO_ACCOUNTING
2520 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2521 {
2522 struct task_io_accounting acct = task->ioac;
2523 unsigned long flags;
2524 int result;
2525
2526 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2527 if (result)
2528 return result;
2529
2530 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2531 result = -EACCES;
2532 goto out_unlock;
2533 }
2534
2535 if (whole && lock_task_sighand(task, &flags)) {
2536 struct task_struct *t = task;
2537
2538 task_io_accounting_add(&acct, &task->signal->ioac);
2539 while_each_thread(task, t)
2540 task_io_accounting_add(&acct, &t->ioac);
2541
2542 unlock_task_sighand(task, &flags);
2543 }
2544 seq_printf(m,
2545 "rchar: %llu\n"
2546 "wchar: %llu\n"
2547 "syscr: %llu\n"
2548 "syscw: %llu\n"
2549 "read_bytes: %llu\n"
2550 "write_bytes: %llu\n"
2551 "cancelled_write_bytes: %llu\n",
2552 (unsigned long long)acct.rchar,
2553 (unsigned long long)acct.wchar,
2554 (unsigned long long)acct.syscr,
2555 (unsigned long long)acct.syscw,
2556 (unsigned long long)acct.read_bytes,
2557 (unsigned long long)acct.write_bytes,
2558 (unsigned long long)acct.cancelled_write_bytes);
2559 result = 0;
2560
2561 out_unlock:
2562 mutex_unlock(&task->signal->cred_guard_mutex);
2563 return result;
2564 }
2565
2566 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2567 struct pid *pid, struct task_struct *task)
2568 {
2569 return do_io_accounting(task, m, 0);
2570 }
2571
2572 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2573 struct pid *pid, struct task_struct *task)
2574 {
2575 return do_io_accounting(task, m, 1);
2576 }
2577 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2578
2579 #ifdef CONFIG_USER_NS
2580 static int proc_id_map_open(struct inode *inode, struct file *file,
2581 const struct seq_operations *seq_ops)
2582 {
2583 struct user_namespace *ns = NULL;
2584 struct task_struct *task;
2585 struct seq_file *seq;
2586 int ret = -EINVAL;
2587
2588 task = get_proc_task(inode);
2589 if (task) {
2590 rcu_read_lock();
2591 ns = get_user_ns(task_cred_xxx(task, user_ns));
2592 rcu_read_unlock();
2593 put_task_struct(task);
2594 }
2595 if (!ns)
2596 goto err;
2597
2598 ret = seq_open(file, seq_ops);
2599 if (ret)
2600 goto err_put_ns;
2601
2602 seq = file->private_data;
2603 seq->private = ns;
2604
2605 return 0;
2606 err_put_ns:
2607 put_user_ns(ns);
2608 err:
2609 return ret;
2610 }
2611
2612 static int proc_id_map_release(struct inode *inode, struct file *file)
2613 {
2614 struct seq_file *seq = file->private_data;
2615 struct user_namespace *ns = seq->private;
2616 put_user_ns(ns);
2617 return seq_release(inode, file);
2618 }
2619
2620 static int proc_uid_map_open(struct inode *inode, struct file *file)
2621 {
2622 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2623 }
2624
2625 static int proc_gid_map_open(struct inode *inode, struct file *file)
2626 {
2627 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2628 }
2629
2630 static int proc_projid_map_open(struct inode *inode, struct file *file)
2631 {
2632 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2633 }
2634
2635 static const struct file_operations proc_uid_map_operations = {
2636 .open = proc_uid_map_open,
2637 .write = proc_uid_map_write,
2638 .read = seq_read,
2639 .llseek = seq_lseek,
2640 .release = proc_id_map_release,
2641 };
2642
2643 static const struct file_operations proc_gid_map_operations = {
2644 .open = proc_gid_map_open,
2645 .write = proc_gid_map_write,
2646 .read = seq_read,
2647 .llseek = seq_lseek,
2648 .release = proc_id_map_release,
2649 };
2650
2651 static const struct file_operations proc_projid_map_operations = {
2652 .open = proc_projid_map_open,
2653 .write = proc_projid_map_write,
2654 .read = seq_read,
2655 .llseek = seq_lseek,
2656 .release = proc_id_map_release,
2657 };
2658
2659 static int proc_setgroups_open(struct inode *inode, struct file *file)
2660 {
2661 struct user_namespace *ns = NULL;
2662 struct task_struct *task;
2663 int ret;
2664
2665 ret = -ESRCH;
2666 task = get_proc_task(inode);
2667 if (task) {
2668 rcu_read_lock();
2669 ns = get_user_ns(task_cred_xxx(task, user_ns));
2670 rcu_read_unlock();
2671 put_task_struct(task);
2672 }
2673 if (!ns)
2674 goto err;
2675
2676 if (file->f_mode & FMODE_WRITE) {
2677 ret = -EACCES;
2678 if (!ns_capable(ns, CAP_SYS_ADMIN))
2679 goto err_put_ns;
2680 }
2681
2682 ret = single_open(file, &proc_setgroups_show, ns);
2683 if (ret)
2684 goto err_put_ns;
2685
2686 return 0;
2687 err_put_ns:
2688 put_user_ns(ns);
2689 err:
2690 return ret;
2691 }
2692
2693 static int proc_setgroups_release(struct inode *inode, struct file *file)
2694 {
2695 struct seq_file *seq = file->private_data;
2696 struct user_namespace *ns = seq->private;
2697 int ret = single_release(inode, file);
2698 put_user_ns(ns);
2699 return ret;
2700 }
2701
2702 static const struct file_operations proc_setgroups_operations = {
2703 .open = proc_setgroups_open,
2704 .write = proc_setgroups_write,
2705 .read = seq_read,
2706 .llseek = seq_lseek,
2707 .release = proc_setgroups_release,
2708 };
2709 #endif /* CONFIG_USER_NS */
2710
2711 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2712 struct pid *pid, struct task_struct *task)
2713 {
2714 int err = lock_trace(task);
2715 if (!err) {
2716 seq_printf(m, "%08x\n", task->personality);
2717 unlock_trace(task);
2718 }
2719 return err;
2720 }
2721
2722 /*
2723 * Thread groups
2724 */
2725 static const struct file_operations proc_task_operations;
2726 static const struct inode_operations proc_task_inode_operations;
2727
2728 static const struct pid_entry tgid_base_stuff[] = {
2729 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2730 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2731 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2732 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2733 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2734 #ifdef CONFIG_NET
2735 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2736 #endif
2737 REG("environ", S_IRUSR, proc_environ_operations),
2738 ONE("auxv", S_IRUSR, proc_pid_auxv),
2739 ONE("status", S_IRUGO, proc_pid_status),
2740 ONE("personality", S_IRUSR, proc_pid_personality),
2741 ONE("limits", S_IRUGO, proc_pid_limits),
2742 #ifdef CONFIG_SCHED_DEBUG
2743 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2744 #endif
2745 #ifdef CONFIG_SCHED_AUTOGROUP
2746 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2747 #endif
2748 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2749 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2750 ONE("syscall", S_IRUSR, proc_pid_syscall),
2751 #endif
2752 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
2753 ONE("stat", S_IRUGO, proc_tgid_stat),
2754 ONE("statm", S_IRUGO, proc_pid_statm),
2755 REG("maps", S_IRUGO, proc_pid_maps_operations),
2756 #ifdef CONFIG_NUMA
2757 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
2758 #endif
2759 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2760 LNK("cwd", proc_cwd_link),
2761 LNK("root", proc_root_link),
2762 LNK("exe", proc_exe_link),
2763 REG("mounts", S_IRUGO, proc_mounts_operations),
2764 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2765 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2766 #ifdef CONFIG_PROC_PAGE_MONITOR
2767 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2768 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
2769 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2770 #endif
2771 #ifdef CONFIG_SECURITY
2772 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2773 #endif
2774 #ifdef CONFIG_KALLSYMS
2775 ONE("wchan", S_IRUGO, proc_pid_wchan),
2776 #endif
2777 #ifdef CONFIG_STACKTRACE
2778 ONE("stack", S_IRUSR, proc_pid_stack),
2779 #endif
2780 #ifdef CONFIG_SCHED_INFO
2781 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
2782 #endif
2783 #ifdef CONFIG_LATENCYTOP
2784 REG("latency", S_IRUGO, proc_lstats_operations),
2785 #endif
2786 #ifdef CONFIG_PROC_PID_CPUSET
2787 ONE("cpuset", S_IRUGO, proc_cpuset_show),
2788 #endif
2789 #ifdef CONFIG_CGROUPS
2790 ONE("cgroup", S_IRUGO, proc_cgroup_show),
2791 #endif
2792 ONE("oom_score", S_IRUGO, proc_oom_score),
2793 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
2794 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2795 #ifdef CONFIG_AUDITSYSCALL
2796 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2797 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2798 #endif
2799 #ifdef CONFIG_FAULT_INJECTION
2800 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2801 #endif
2802 #ifdef CONFIG_ELF_CORE
2803 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2804 #endif
2805 #ifdef CONFIG_TASK_IO_ACCOUNTING
2806 ONE("io", S_IRUSR, proc_tgid_io_accounting),
2807 #endif
2808 #ifdef CONFIG_HARDWALL
2809 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
2810 #endif
2811 #ifdef CONFIG_USER_NS
2812 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
2813 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
2814 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
2815 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
2816 #endif
2817 #ifdef CONFIG_CHECKPOINT_RESTORE
2818 REG("timers", S_IRUGO, proc_timers_operations),
2819 #endif
2820 };
2821
2822 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
2823 {
2824 return proc_pident_readdir(file, ctx,
2825 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2826 }
2827
2828 static const struct file_operations proc_tgid_base_operations = {
2829 .read = generic_read_dir,
2830 .iterate = proc_tgid_base_readdir,
2831 .llseek = default_llseek,
2832 };
2833
2834 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
2835 {
2836 return proc_pident_lookup(dir, dentry,
2837 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2838 }
2839
2840 static const struct inode_operations proc_tgid_base_inode_operations = {
2841 .lookup = proc_tgid_base_lookup,
2842 .getattr = pid_getattr,
2843 .setattr = proc_setattr,
2844 .permission = proc_pid_permission,
2845 };
2846
2847 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2848 {
2849 struct dentry *dentry, *leader, *dir;
2850 char buf[PROC_NUMBUF];
2851 struct qstr name;
2852
2853 name.name = buf;
2854 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2855 /* no ->d_hash() rejects on procfs */
2856 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2857 if (dentry) {
2858 d_invalidate(dentry);
2859 dput(dentry);
2860 }
2861
2862 if (pid == tgid)
2863 return;
2864
2865 name.name = buf;
2866 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2867 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2868 if (!leader)
2869 goto out;
2870
2871 name.name = "task";
2872 name.len = strlen(name.name);
2873 dir = d_hash_and_lookup(leader, &name);
2874 if (!dir)
2875 goto out_put_leader;
2876
2877 name.name = buf;
2878 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2879 dentry = d_hash_and_lookup(dir, &name);
2880 if (dentry) {
2881 d_invalidate(dentry);
2882 dput(dentry);
2883 }
2884
2885 dput(dir);
2886 out_put_leader:
2887 dput(leader);
2888 out:
2889 return;
2890 }
2891
2892 /**
2893 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2894 * @task: task that should be flushed.
2895 *
2896 * When flushing dentries from proc, one needs to flush them from global
2897 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2898 * in. This call is supposed to do all of this job.
2899 *
2900 * Looks in the dcache for
2901 * /proc/@pid
2902 * /proc/@tgid/task/@pid
2903 * if either directory is present flushes it and all of it'ts children
2904 * from the dcache.
2905 *
2906 * It is safe and reasonable to cache /proc entries for a task until
2907 * that task exits. After that they just clog up the dcache with
2908 * useless entries, possibly causing useful dcache entries to be
2909 * flushed instead. This routine is proved to flush those useless
2910 * dcache entries at process exit time.
2911 *
2912 * NOTE: This routine is just an optimization so it does not guarantee
2913 * that no dcache entries will exist at process exit time it
2914 * just makes it very unlikely that any will persist.
2915 */
2916
2917 void proc_flush_task(struct task_struct *task)
2918 {
2919 int i;
2920 struct pid *pid, *tgid;
2921 struct upid *upid;
2922
2923 pid = task_pid(task);
2924 tgid = task_tgid(task);
2925
2926 for (i = 0; i <= pid->level; i++) {
2927 upid = &pid->numbers[i];
2928 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2929 tgid->numbers[i].nr);
2930 }
2931 }
2932
2933 static int proc_pid_instantiate(struct inode *dir,
2934 struct dentry * dentry,
2935 struct task_struct *task, const void *ptr)
2936 {
2937 struct inode *inode;
2938
2939 inode = proc_pid_make_inode(dir->i_sb, task);
2940 if (!inode)
2941 goto out;
2942
2943 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2944 inode->i_op = &proc_tgid_base_inode_operations;
2945 inode->i_fop = &proc_tgid_base_operations;
2946 inode->i_flags|=S_IMMUTABLE;
2947
2948 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
2949 ARRAY_SIZE(tgid_base_stuff)));
2950
2951 d_set_d_op(dentry, &pid_dentry_operations);
2952
2953 d_add(dentry, inode);
2954 /* Close the race of the process dying before we return the dentry */
2955 if (pid_revalidate(dentry, 0))
2956 return 0;
2957 out:
2958 return -ENOENT;
2959 }
2960
2961 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
2962 {
2963 int result = -ENOENT;
2964 struct task_struct *task;
2965 unsigned tgid;
2966 struct pid_namespace *ns;
2967
2968 tgid = name_to_int(&dentry->d_name);
2969 if (tgid == ~0U)
2970 goto out;
2971
2972 ns = dentry->d_sb->s_fs_info;
2973 rcu_read_lock();
2974 task = find_task_by_pid_ns(tgid, ns);
2975 if (task)
2976 get_task_struct(task);
2977 rcu_read_unlock();
2978 if (!task)
2979 goto out;
2980
2981 result = proc_pid_instantiate(dir, dentry, task, NULL);
2982 put_task_struct(task);
2983 out:
2984 return ERR_PTR(result);
2985 }
2986
2987 /*
2988 * Find the first task with tgid >= tgid
2989 *
2990 */
2991 struct tgid_iter {
2992 unsigned int tgid;
2993 struct task_struct *task;
2994 };
2995 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2996 {
2997 struct pid *pid;
2998
2999 if (iter.task)
3000 put_task_struct(iter.task);
3001 rcu_read_lock();
3002 retry:
3003 iter.task = NULL;
3004 pid = find_ge_pid(iter.tgid, ns);
3005 if (pid) {
3006 iter.tgid = pid_nr_ns(pid, ns);
3007 iter.task = pid_task(pid, PIDTYPE_PID);
3008 /* What we to know is if the pid we have find is the
3009 * pid of a thread_group_leader. Testing for task
3010 * being a thread_group_leader is the obvious thing
3011 * todo but there is a window when it fails, due to
3012 * the pid transfer logic in de_thread.
3013 *
3014 * So we perform the straight forward test of seeing
3015 * if the pid we have found is the pid of a thread
3016 * group leader, and don't worry if the task we have
3017 * found doesn't happen to be a thread group leader.
3018 * As we don't care in the case of readdir.
3019 */
3020 if (!iter.task || !has_group_leader_pid(iter.task)) {
3021 iter.tgid += 1;
3022 goto retry;
3023 }
3024 get_task_struct(iter.task);
3025 }
3026 rcu_read_unlock();
3027 return iter;
3028 }
3029
3030 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3031
3032 /* for the /proc/ directory itself, after non-process stuff has been done */
3033 int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3034 {
3035 struct tgid_iter iter;
3036 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info;
3037 loff_t pos = ctx->pos;
3038
3039 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3040 return 0;
3041
3042 if (pos == TGID_OFFSET - 2) {
3043 struct inode *inode = d_inode(ns->proc_self);
3044 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3045 return 0;
3046 ctx->pos = pos = pos + 1;
3047 }
3048 if (pos == TGID_OFFSET - 1) {
3049 struct inode *inode = d_inode(ns->proc_thread_self);
3050 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3051 return 0;
3052 ctx->pos = pos = pos + 1;
3053 }
3054 iter.tgid = pos - TGID_OFFSET;
3055 iter.task = NULL;
3056 for (iter = next_tgid(ns, iter);
3057 iter.task;
3058 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3059 char name[PROC_NUMBUF];
3060 int len;
3061 if (!has_pid_permissions(ns, iter.task, 2))
3062 continue;
3063
3064 len = snprintf(name, sizeof(name), "%d", iter.tgid);
3065 ctx->pos = iter.tgid + TGID_OFFSET;
3066 if (!proc_fill_cache(file, ctx, name, len,
3067 proc_pid_instantiate, iter.task, NULL)) {
3068 put_task_struct(iter.task);
3069 return 0;
3070 }
3071 }
3072 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3073 return 0;
3074 }
3075
3076 /*
3077 * Tasks
3078 */
3079 static const struct pid_entry tid_base_stuff[] = {
3080 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3081 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3082 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3083 #ifdef CONFIG_NET
3084 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3085 #endif
3086 REG("environ", S_IRUSR, proc_environ_operations),
3087 ONE("auxv", S_IRUSR, proc_pid_auxv),
3088 ONE("status", S_IRUGO, proc_pid_status),
3089 ONE("personality", S_IRUSR, proc_pid_personality),
3090 ONE("limits", S_IRUGO, proc_pid_limits),
3091 #ifdef CONFIG_SCHED_DEBUG
3092 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3093 #endif
3094 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3095 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3096 ONE("syscall", S_IRUSR, proc_pid_syscall),
3097 #endif
3098 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3099 ONE("stat", S_IRUGO, proc_tid_stat),
3100 ONE("statm", S_IRUGO, proc_pid_statm),
3101 REG("maps", S_IRUGO, proc_tid_maps_operations),
3102 #ifdef CONFIG_PROC_CHILDREN
3103 REG("children", S_IRUGO, proc_tid_children_operations),
3104 #endif
3105 #ifdef CONFIG_NUMA
3106 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3107 #endif
3108 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3109 LNK("cwd", proc_cwd_link),
3110 LNK("root", proc_root_link),
3111 LNK("exe", proc_exe_link),
3112 REG("mounts", S_IRUGO, proc_mounts_operations),
3113 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3114 #ifdef CONFIG_PROC_PAGE_MONITOR
3115 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3116 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
3117 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3118 #endif
3119 #ifdef CONFIG_SECURITY
3120 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3121 #endif
3122 #ifdef CONFIG_KALLSYMS
3123 ONE("wchan", S_IRUGO, proc_pid_wchan),
3124 #endif
3125 #ifdef CONFIG_STACKTRACE
3126 ONE("stack", S_IRUSR, proc_pid_stack),
3127 #endif
3128 #ifdef CONFIG_SCHED_INFO
3129 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3130 #endif
3131 #ifdef CONFIG_LATENCYTOP
3132 REG("latency", S_IRUGO, proc_lstats_operations),
3133 #endif
3134 #ifdef CONFIG_PROC_PID_CPUSET
3135 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3136 #endif
3137 #ifdef CONFIG_CGROUPS
3138 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3139 #endif
3140 ONE("oom_score", S_IRUGO, proc_oom_score),
3141 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3142 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3143 #ifdef CONFIG_AUDITSYSCALL
3144 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3145 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3146 #endif
3147 #ifdef CONFIG_FAULT_INJECTION
3148 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3149 #endif
3150 #ifdef CONFIG_TASK_IO_ACCOUNTING
3151 ONE("io", S_IRUSR, proc_tid_io_accounting),
3152 #endif
3153 #ifdef CONFIG_HARDWALL
3154 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
3155 #endif
3156 #ifdef CONFIG_USER_NS
3157 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3158 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3159 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3160 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3161 #endif
3162 };
3163
3164 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3165 {
3166 return proc_pident_readdir(file, ctx,
3167 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3168 }
3169
3170 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3171 {
3172 return proc_pident_lookup(dir, dentry,
3173 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3174 }
3175
3176 static const struct file_operations proc_tid_base_operations = {
3177 .read = generic_read_dir,
3178 .iterate = proc_tid_base_readdir,
3179 .llseek = default_llseek,
3180 };
3181
3182 static const struct inode_operations proc_tid_base_inode_operations = {
3183 .lookup = proc_tid_base_lookup,
3184 .getattr = pid_getattr,
3185 .setattr = proc_setattr,
3186 };
3187
3188 static int proc_task_instantiate(struct inode *dir,
3189 struct dentry *dentry, struct task_struct *task, const void *ptr)
3190 {
3191 struct inode *inode;
3192 inode = proc_pid_make_inode(dir->i_sb, task);
3193
3194 if (!inode)
3195 goto out;
3196 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3197 inode->i_op = &proc_tid_base_inode_operations;
3198 inode->i_fop = &proc_tid_base_operations;
3199 inode->i_flags|=S_IMMUTABLE;
3200
3201 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3202 ARRAY_SIZE(tid_base_stuff)));
3203
3204 d_set_d_op(dentry, &pid_dentry_operations);
3205
3206 d_add(dentry, inode);
3207 /* Close the race of the process dying before we return the dentry */
3208 if (pid_revalidate(dentry, 0))
3209 return 0;
3210 out:
3211 return -ENOENT;
3212 }
3213
3214 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3215 {
3216 int result = -ENOENT;
3217 struct task_struct *task;
3218 struct task_struct *leader = get_proc_task(dir);
3219 unsigned tid;
3220 struct pid_namespace *ns;
3221
3222 if (!leader)
3223 goto out_no_task;
3224
3225 tid = name_to_int(&dentry->d_name);
3226 if (tid == ~0U)
3227 goto out;
3228
3229 ns = dentry->d_sb->s_fs_info;
3230 rcu_read_lock();
3231 task = find_task_by_pid_ns(tid, ns);
3232 if (task)
3233 get_task_struct(task);
3234 rcu_read_unlock();
3235 if (!task)
3236 goto out;
3237 if (!same_thread_group(leader, task))
3238 goto out_drop_task;
3239
3240 result = proc_task_instantiate(dir, dentry, task, NULL);
3241 out_drop_task:
3242 put_task_struct(task);
3243 out:
3244 put_task_struct(leader);
3245 out_no_task:
3246 return ERR_PTR(result);
3247 }
3248
3249 /*
3250 * Find the first tid of a thread group to return to user space.
3251 *
3252 * Usually this is just the thread group leader, but if the users
3253 * buffer was too small or there was a seek into the middle of the
3254 * directory we have more work todo.
3255 *
3256 * In the case of a short read we start with find_task_by_pid.
3257 *
3258 * In the case of a seek we start with the leader and walk nr
3259 * threads past it.
3260 */
3261 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3262 struct pid_namespace *ns)
3263 {
3264 struct task_struct *pos, *task;
3265 unsigned long nr = f_pos;
3266
3267 if (nr != f_pos) /* 32bit overflow? */
3268 return NULL;
3269
3270 rcu_read_lock();
3271 task = pid_task(pid, PIDTYPE_PID);
3272 if (!task)
3273 goto fail;
3274
3275 /* Attempt to start with the tid of a thread */
3276 if (tid && nr) {
3277 pos = find_task_by_pid_ns(tid, ns);
3278 if (pos && same_thread_group(pos, task))
3279 goto found;
3280 }
3281
3282 /* If nr exceeds the number of threads there is nothing todo */
3283 if (nr >= get_nr_threads(task))
3284 goto fail;
3285
3286 /* If we haven't found our starting place yet start
3287 * with the leader and walk nr threads forward.
3288 */
3289 pos = task = task->group_leader;
3290 do {
3291 if (!nr--)
3292 goto found;
3293 } while_each_thread(task, pos);
3294 fail:
3295 pos = NULL;
3296 goto out;
3297 found:
3298 get_task_struct(pos);
3299 out:
3300 rcu_read_unlock();
3301 return pos;
3302 }
3303
3304 /*
3305 * Find the next thread in the thread list.
3306 * Return NULL if there is an error or no next thread.
3307 *
3308 * The reference to the input task_struct is released.
3309 */
3310 static struct task_struct *next_tid(struct task_struct *start)
3311 {
3312 struct task_struct *pos = NULL;
3313 rcu_read_lock();
3314 if (pid_alive(start)) {
3315 pos = next_thread(start);
3316 if (thread_group_leader(pos))
3317 pos = NULL;
3318 else
3319 get_task_struct(pos);
3320 }
3321 rcu_read_unlock();
3322 put_task_struct(start);
3323 return pos;
3324 }
3325
3326 /* for the /proc/TGID/task/ directories */
3327 static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3328 {
3329 struct inode *inode = file_inode(file);
3330 struct task_struct *task;
3331 struct pid_namespace *ns;
3332 int tid;
3333
3334 if (proc_inode_is_dead(inode))
3335 return -ENOENT;
3336
3337 if (!dir_emit_dots(file, ctx))
3338 return 0;
3339
3340 /* f_version caches the tgid value that the last readdir call couldn't
3341 * return. lseek aka telldir automagically resets f_version to 0.
3342 */
3343 ns = inode->i_sb->s_fs_info;
3344 tid = (int)file->f_version;
3345 file->f_version = 0;
3346 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3347 task;
3348 task = next_tid(task), ctx->pos++) {
3349 char name[PROC_NUMBUF];
3350 int len;
3351 tid = task_pid_nr_ns(task, ns);
3352 len = snprintf(name, sizeof(name), "%d", tid);
3353 if (!proc_fill_cache(file, ctx, name, len,
3354 proc_task_instantiate, task, NULL)) {
3355 /* returning this tgid failed, save it as the first
3356 * pid for the next readir call */
3357 file->f_version = (u64)tid;
3358 put_task_struct(task);
3359 break;
3360 }
3361 }
3362
3363 return 0;
3364 }
3365
3366 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3367 {
3368 struct inode *inode = d_inode(dentry);
3369 struct task_struct *p = get_proc_task(inode);
3370 generic_fillattr(inode, stat);
3371
3372 if (p) {
3373 stat->nlink += get_nr_threads(p);
3374 put_task_struct(p);
3375 }
3376
3377 return 0;
3378 }
3379
3380 static const struct inode_operations proc_task_inode_operations = {
3381 .lookup = proc_task_lookup,
3382 .getattr = proc_task_getattr,
3383 .setattr = proc_setattr,
3384 .permission = proc_pid_permission,
3385 };
3386
3387 static const struct file_operations proc_task_operations = {
3388 .read = generic_read_dir,
3389 .iterate = proc_task_readdir,
3390 .llseek = default_llseek,
3391 };
Linux with added FPC-III support