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