projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
[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/cgroup.h>
77 #include <linux/cpuset.h>
78 #include <linux/audit.h>
79 #include <linux/poll.h>
80 #include <linux/nsproxy.h>
81 #include <linux/oom.h>
82 #include <linux/elf.h>
83 #include <linux/pid_namespace.h>
84 #include <linux/user_namespace.h>
85 #include <linux/fs_struct.h>
86 #include <linux/slab.h>
87 #include <linux/flex_array.h>
88 #ifdef CONFIG_HARDWALL
89 #include <asm/hardwall.h>
90 #endif
91 #include <trace/events/oom.h>
92 #include "internal.h"
93 #include "fd.h"
94
95 /* NOTE:
96 * Implementing inode permission operations in /proc is almost
97 * certainly an error. Permission checks need to happen during
98 * each system call not at open time. The reason is that most of
99 * what we wish to check for permissions in /proc varies at runtime.
100 *
101 * The classic example of a problem is opening file descriptors
102 * in /proc for a task before it execs a suid executable.
103 */
104
105 struct pid_entry {
106 char *name;
107 int len;
108 umode_t mode;
109 const struct inode_operations *iop;
110 const struct file_operations *fop;
111 union proc_op op;
112 };
113
114 #define NOD(NAME, MODE, IOP, FOP, OP) { \
115 .name = (NAME), \
116 .len = sizeof(NAME) - 1, \
117 .mode = MODE, \
118 .iop = IOP, \
119 .fop = FOP, \
120 .op = OP, \
121 }
122
123 #define DIR(NAME, MODE, iops, fops) \
124 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
125 #define LNK(NAME, get_link) \
126 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
127 &proc_pid_link_inode_operations, NULL, \
128 { .proc_get_link = get_link } )
129 #define REG(NAME, MODE, fops) \
130 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
131 #define INF(NAME, MODE, read) \
132 NOD(NAME, (S_IFREG|(MODE)), \
133 NULL, &proc_info_file_operations, \
134 { .proc_read = read } )
135 #define ONE(NAME, MODE, show) \
136 NOD(NAME, (S_IFREG|(MODE)), \
137 NULL, &proc_single_file_operations, \
138 { .proc_show = show } )
139
140 /*
141 * Count the number of hardlinks for the pid_entry table, excluding the .
142 * and .. links.
143 */
144 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
145 unsigned int n)
146 {
147 unsigned int i;
148 unsigned int count;
149
150 count = 0;
151 for (i = 0; i < n; ++i) {
152 if (S_ISDIR(entries[i].mode))
153 ++count;
154 }
155
156 return count;
157 }
158
159 static int get_task_root(struct task_struct *task, struct path *root)
160 {
161 int result = -ENOENT;
162
163 task_lock(task);
164 if (task->fs) {
165 get_fs_root(task->fs, root);
166 result = 0;
167 }
168 task_unlock(task);
169 return result;
170 }
171
172 static int proc_cwd_link(struct dentry *dentry, struct path *path)
173 {
174 struct task_struct *task = get_proc_task(dentry->d_inode);
175 int result = -ENOENT;
176
177 if (task) {
178 task_lock(task);
179 if (task->fs) {
180 get_fs_pwd(task->fs, path);
181 result = 0;
182 }
183 task_unlock(task);
184 put_task_struct(task);
185 }
186 return result;
187 }
188
189 static int proc_root_link(struct dentry *dentry, struct path *path)
190 {
191 struct task_struct *task = get_proc_task(dentry->d_inode);
192 int result = -ENOENT;
193
194 if (task) {
195 result = get_task_root(task, path);
196 put_task_struct(task);
197 }
198 return result;
199 }
200
201 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
202 {
203 int res = 0;
204 unsigned int len;
205 struct mm_struct *mm = get_task_mm(task);
206 if (!mm)
207 goto out;
208 if (!mm->arg_end)
209 goto out_mm; /* Shh! No looking before we're done */
210
211 len = mm->arg_end - mm->arg_start;
212
213 if (len > PAGE_SIZE)
214 len = PAGE_SIZE;
215
216 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
217
218 // If the nul at the end of args has been overwritten, then
219 // assume application is using setproctitle(3).
220 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
221 len = strnlen(buffer, res);
222 if (len < res) {
223 res = len;
224 } else {
225 len = mm->env_end - mm->env_start;
226 if (len > PAGE_SIZE - res)
227 len = PAGE_SIZE - res;
228 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
229 res = strnlen(buffer, res);
230 }
231 }
232 out_mm:
233 mmput(mm);
234 out:
235 return res;
236 }
237
238 static int proc_pid_auxv(struct task_struct *task, char *buffer)
239 {
240 struct mm_struct *mm = mm_access(task, PTRACE_MODE_READ);
241 int res = PTR_ERR(mm);
242 if (mm && !IS_ERR(mm)) {
243 unsigned int nwords = 0;
244 do {
245 nwords += 2;
246 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
247 res = nwords * sizeof(mm->saved_auxv[0]);
248 if (res > PAGE_SIZE)
249 res = PAGE_SIZE;
250 memcpy(buffer, mm->saved_auxv, res);
251 mmput(mm);
252 }
253 return res;
254 }
255
256
257 #ifdef CONFIG_KALLSYMS
258 /*
259 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
260 * Returns the resolved symbol. If that fails, simply return the address.
261 */
262 static int proc_pid_wchan(struct task_struct *task, char *buffer)
263 {
264 unsigned long wchan;
265 char symname[KSYM_NAME_LEN];
266
267 wchan = get_wchan(task);
268
269 if (lookup_symbol_name(wchan, symname) < 0)
270 if (!ptrace_may_access(task, PTRACE_MODE_READ))
271 return 0;
272 else
273 return sprintf(buffer, "%lu", wchan);
274 else
275 return sprintf(buffer, "%s", symname);
276 }
277 #endif /* CONFIG_KALLSYMS */
278
279 static int lock_trace(struct task_struct *task)
280 {
281 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
282 if (err)
283 return err;
284 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
285 mutex_unlock(&task->signal->cred_guard_mutex);
286 return -EPERM;
287 }
288 return 0;
289 }
290
291 static void unlock_trace(struct task_struct *task)
292 {
293 mutex_unlock(&task->signal->cred_guard_mutex);
294 }
295
296 #ifdef CONFIG_STACKTRACE
297
298 #define MAX_STACK_TRACE_DEPTH 64
299
300 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
301 struct pid *pid, struct task_struct *task)
302 {
303 struct stack_trace trace;
304 unsigned long *entries;
305 int err;
306 int i;
307
308 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
309 if (!entries)
310 return -ENOMEM;
311
312 trace.nr_entries = 0;
313 trace.max_entries = MAX_STACK_TRACE_DEPTH;
314 trace.entries = entries;
315 trace.skip = 0;
316
317 err = lock_trace(task);
318 if (!err) {
319 save_stack_trace_tsk(task, &trace);
320
321 for (i = 0; i < trace.nr_entries; i++) {
322 seq_printf(m, "[<%pK>] %pS\n",
323 (void *)entries[i], (void *)entries[i]);
324 }
325 unlock_trace(task);
326 }
327 kfree(entries);
328
329 return err;
330 }
331 #endif
332
333 #ifdef CONFIG_SCHEDSTATS
334 /*
335 * Provides /proc/PID/schedstat
336 */
337 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
338 {
339 return sprintf(buffer, "%llu %llu %lu\n",
340 (unsigned long long)task->se.sum_exec_runtime,
341 (unsigned long long)task->sched_info.run_delay,
342 task->sched_info.pcount);
343 }
344 #endif
345
346 #ifdef CONFIG_LATENCYTOP
347 static int lstats_show_proc(struct seq_file *m, void *v)
348 {
349 int i;
350 struct inode *inode = m->private;
351 struct task_struct *task = get_proc_task(inode);
352
353 if (!task)
354 return -ESRCH;
355 seq_puts(m, "Latency Top version : v0.1\n");
356 for (i = 0; i < 32; i++) {
357 struct latency_record *lr = &task->latency_record[i];
358 if (lr->backtrace[0]) {
359 int q;
360 seq_printf(m, "%i %li %li",
361 lr->count, lr->time, lr->max);
362 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
363 unsigned long bt = lr->backtrace[q];
364 if (!bt)
365 break;
366 if (bt == ULONG_MAX)
367 break;
368 seq_printf(m, " %ps", (void *)bt);
369 }
370 seq_putc(m, '\n');
371 }
372
373 }
374 put_task_struct(task);
375 return 0;
376 }
377
378 static int lstats_open(struct inode *inode, struct file *file)
379 {
380 return single_open(file, lstats_show_proc, inode);
381 }
382
383 static ssize_t lstats_write(struct file *file, const char __user *buf,
384 size_t count, loff_t *offs)
385 {
386 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
387
388 if (!task)
389 return -ESRCH;
390 clear_all_latency_tracing(task);
391 put_task_struct(task);
392
393 return count;
394 }
395
396 static const struct file_operations proc_lstats_operations = {
397 .open = lstats_open,
398 .read = seq_read,
399 .write = lstats_write,
400 .llseek = seq_lseek,
401 .release = single_release,
402 };
403
404 #endif
405
406 static int proc_oom_score(struct task_struct *task, char *buffer)
407 {
408 unsigned long totalpages = totalram_pages + total_swap_pages;
409 unsigned long points = 0;
410
411 read_lock(&tasklist_lock);
412 if (pid_alive(task))
413 points = oom_badness(task, NULL, NULL, totalpages) *
414 1000 / totalpages;
415 read_unlock(&tasklist_lock);
416 return sprintf(buffer, "%lu\n", points);
417 }
418
419 struct limit_names {
420 char *name;
421 char *unit;
422 };
423
424 static const struct limit_names lnames[RLIM_NLIMITS] = {
425 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
426 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
427 [RLIMIT_DATA] = {"Max data size", "bytes"},
428 [RLIMIT_STACK] = {"Max stack size", "bytes"},
429 [RLIMIT_CORE] = {"Max core file size", "bytes"},
430 [RLIMIT_RSS] = {"Max resident set", "bytes"},
431 [RLIMIT_NPROC] = {"Max processes", "processes"},
432 [RLIMIT_NOFILE] = {"Max open files", "files"},
433 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
434 [RLIMIT_AS] = {"Max address space", "bytes"},
435 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
436 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
437 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
438 [RLIMIT_NICE] = {"Max nice priority", NULL},
439 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
440 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
441 };
442
443 /* Display limits for a process */
444 static int proc_pid_limits(struct task_struct *task, char *buffer)
445 {
446 unsigned int i;
447 int count = 0;
448 unsigned long flags;
449 char *bufptr = buffer;
450
451 struct rlimit rlim[RLIM_NLIMITS];
452
453 if (!lock_task_sighand(task, &flags))
454 return 0;
455 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
456 unlock_task_sighand(task, &flags);
457
458 /*
459 * print the file header
460 */
461 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
462 "Limit", "Soft Limit", "Hard Limit", "Units");
463
464 for (i = 0; i < RLIM_NLIMITS; i++) {
465 if (rlim[i].rlim_cur == RLIM_INFINITY)
466 count += sprintf(&bufptr[count], "%-25s %-20s ",
467 lnames[i].name, "unlimited");
468 else
469 count += sprintf(&bufptr[count], "%-25s %-20lu ",
470 lnames[i].name, rlim[i].rlim_cur);
471
472 if (rlim[i].rlim_max == RLIM_INFINITY)
473 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
474 else
475 count += sprintf(&bufptr[count], "%-20lu ",
476 rlim[i].rlim_max);
477
478 if (lnames[i].unit)
479 count += sprintf(&bufptr[count], "%-10s\n",
480 lnames[i].unit);
481 else
482 count += sprintf(&bufptr[count], "\n");
483 }
484
485 return count;
486 }
487
488 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
489 static int proc_pid_syscall(struct task_struct *task, char *buffer)
490 {
491 long nr;
492 unsigned long args[6], sp, pc;
493 int res = lock_trace(task);
494 if (res)
495 return res;
496
497 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
498 res = sprintf(buffer, "running\n");
499 else if (nr < 0)
500 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
501 else
502 res = sprintf(buffer,
503 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
504 nr,
505 args[0], args[1], args[2], args[3], args[4], args[5],
506 sp, pc);
507 unlock_trace(task);
508 return res;
509 }
510 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
511
512 /************************************************************************/
513 /* Here the fs part begins */
514 /************************************************************************/
515
516 /* permission checks */
517 static int proc_fd_access_allowed(struct inode *inode)
518 {
519 struct task_struct *task;
520 int allowed = 0;
521 /* Allow access to a task's file descriptors if it is us or we
522 * may use ptrace attach to the process and find out that
523 * information.
524 */
525 task = get_proc_task(inode);
526 if (task) {
527 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
528 put_task_struct(task);
529 }
530 return allowed;
531 }
532
533 int proc_setattr(struct dentry *dentry, struct iattr *attr)
534 {
535 int error;
536 struct inode *inode = dentry->d_inode;
537
538 if (attr->ia_valid & ATTR_MODE)
539 return -EPERM;
540
541 error = inode_change_ok(inode, attr);
542 if (error)
543 return error;
544
545 if ((attr->ia_valid & ATTR_SIZE) &&
546 attr->ia_size != i_size_read(inode)) {
547 error = vmtruncate(inode, attr->ia_size);
548 if (error)
549 return error;
550 }
551
552 setattr_copy(inode, attr);
553 mark_inode_dirty(inode);
554 return 0;
555 }
556
557 /*
558 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
559 * or euid/egid (for hide_pid_min=2)?
560 */
561 static bool has_pid_permissions(struct pid_namespace *pid,
562 struct task_struct *task,
563 int hide_pid_min)
564 {
565 if (pid->hide_pid < hide_pid_min)
566 return true;
567 if (in_group_p(pid->pid_gid))
568 return true;
569 return ptrace_may_access(task, PTRACE_MODE_READ);
570 }
571
572
573 static int proc_pid_permission(struct inode *inode, int mask)
574 {
575 struct pid_namespace *pid = inode->i_sb->s_fs_info;
576 struct task_struct *task;
577 bool has_perms;
578
579 task = get_proc_task(inode);
580 if (!task)
581 return -ESRCH;
582 has_perms = has_pid_permissions(pid, task, 1);
583 put_task_struct(task);
584
585 if (!has_perms) {
586 if (pid->hide_pid == 2) {
587 /*
588 * Let's make getdents(), stat(), and open()
589 * consistent with each other. If a process
590 * may not stat() a file, it shouldn't be seen
591 * in procfs at all.
592 */
593 return -ENOENT;
594 }
595
596 return -EPERM;
597 }
598 return generic_permission(inode, mask);
599 }
600
601
602
603 static const struct inode_operations proc_def_inode_operations = {
604 .setattr = proc_setattr,
605 };
606
607 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
608
609 static ssize_t proc_info_read(struct file * file, char __user * buf,
610 size_t count, loff_t *ppos)
611 {
612 struct inode * inode = file->f_path.dentry->d_inode;
613 unsigned long page;
614 ssize_t length;
615 struct task_struct *task = get_proc_task(inode);
616
617 length = -ESRCH;
618 if (!task)
619 goto out_no_task;
620
621 if (count > PROC_BLOCK_SIZE)
622 count = PROC_BLOCK_SIZE;
623
624 length = -ENOMEM;
625 if (!(page = __get_free_page(GFP_TEMPORARY)))
626 goto out;
627
628 length = PROC_I(inode)->op.proc_read(task, (char*)page);
629
630 if (length >= 0)
631 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
632 free_page(page);
633 out:
634 put_task_struct(task);
635 out_no_task:
636 return length;
637 }
638
639 static const struct file_operations proc_info_file_operations = {
640 .read = proc_info_read,
641 .llseek = generic_file_llseek,
642 };
643
644 static int proc_single_show(struct seq_file *m, void *v)
645 {
646 struct inode *inode = m->private;
647 struct pid_namespace *ns;
648 struct pid *pid;
649 struct task_struct *task;
650 int ret;
651
652 ns = inode->i_sb->s_fs_info;
653 pid = proc_pid(inode);
654 task = get_pid_task(pid, PIDTYPE_PID);
655 if (!task)
656 return -ESRCH;
657
658 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
659
660 put_task_struct(task);
661 return ret;
662 }
663
664 static int proc_single_open(struct inode *inode, struct file *filp)
665 {
666 return single_open(filp, proc_single_show, inode);
667 }
668
669 static const struct file_operations proc_single_file_operations = {
670 .open = proc_single_open,
671 .read = seq_read,
672 .llseek = seq_lseek,
673 .release = single_release,
674 };
675
676 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
677 {
678 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
679 struct mm_struct *mm;
680
681 if (!task)
682 return -ESRCH;
683
684 mm = mm_access(task, mode);
685 put_task_struct(task);
686
687 if (IS_ERR(mm))
688 return PTR_ERR(mm);
689
690 if (mm) {
691 /* ensure this mm_struct can't be freed */
692 atomic_inc(&mm->mm_count);
693 /* but do not pin its memory */
694 mmput(mm);
695 }
696
697 file->private_data = mm;
698
699 return 0;
700 }
701
702 static int mem_open(struct inode *inode, struct file *file)
703 {
704 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
705
706 /* OK to pass negative loff_t, we can catch out-of-range */
707 file->f_mode |= FMODE_UNSIGNED_OFFSET;
708
709 return ret;
710 }
711
712 static ssize_t mem_rw(struct file *file, char __user *buf,
713 size_t count, loff_t *ppos, int write)
714 {
715 struct mm_struct *mm = file->private_data;
716 unsigned long addr = *ppos;
717 ssize_t copied;
718 char *page;
719
720 if (!mm)
721 return 0;
722
723 page = (char *)__get_free_page(GFP_TEMPORARY);
724 if (!page)
725 return -ENOMEM;
726
727 copied = 0;
728 if (!atomic_inc_not_zero(&mm->mm_users))
729 goto free;
730
731 while (count > 0) {
732 int this_len = min_t(int, count, PAGE_SIZE);
733
734 if (write && copy_from_user(page, buf, this_len)) {
735 copied = -EFAULT;
736 break;
737 }
738
739 this_len = access_remote_vm(mm, addr, page, this_len, write);
740 if (!this_len) {
741 if (!copied)
742 copied = -EIO;
743 break;
744 }
745
746 if (!write && copy_to_user(buf, page, this_len)) {
747 copied = -EFAULT;
748 break;
749 }
750
751 buf += this_len;
752 addr += this_len;
753 copied += this_len;
754 count -= this_len;
755 }
756 *ppos = addr;
757
758 mmput(mm);
759 free:
760 free_page((unsigned long) page);
761 return copied;
762 }
763
764 static ssize_t mem_read(struct file *file, char __user *buf,
765 size_t count, loff_t *ppos)
766 {
767 return mem_rw(file, buf, count, ppos, 0);
768 }
769
770 static ssize_t mem_write(struct file *file, const char __user *buf,
771 size_t count, loff_t *ppos)
772 {
773 return mem_rw(file, (char __user*)buf, count, ppos, 1);
774 }
775
776 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
777 {
778 switch (orig) {
779 case 0:
780 file->f_pos = offset;
781 break;
782 case 1:
783 file->f_pos += offset;
784 break;
785 default:
786 return -EINVAL;
787 }
788 force_successful_syscall_return();
789 return file->f_pos;
790 }
791
792 static int mem_release(struct inode *inode, struct file *file)
793 {
794 struct mm_struct *mm = file->private_data;
795 if (mm)
796 mmdrop(mm);
797 return 0;
798 }
799
800 static const struct file_operations proc_mem_operations = {
801 .llseek = mem_lseek,
802 .read = mem_read,
803 .write = mem_write,
804 .open = mem_open,
805 .release = mem_release,
806 };
807
808 static int environ_open(struct inode *inode, struct file *file)
809 {
810 return __mem_open(inode, file, PTRACE_MODE_READ);
811 }
812
813 static ssize_t environ_read(struct file *file, char __user *buf,
814 size_t count, loff_t *ppos)
815 {
816 char *page;
817 unsigned long src = *ppos;
818 int ret = 0;
819 struct mm_struct *mm = file->private_data;
820
821 if (!mm)
822 return 0;
823
824 page = (char *)__get_free_page(GFP_TEMPORARY);
825 if (!page)
826 return -ENOMEM;
827
828 ret = 0;
829 if (!atomic_inc_not_zero(&mm->mm_users))
830 goto free;
831 while (count > 0) {
832 size_t this_len, max_len;
833 int retval;
834
835 if (src >= (mm->env_end - mm->env_start))
836 break;
837
838 this_len = mm->env_end - (mm->env_start + src);
839
840 max_len = min_t(size_t, PAGE_SIZE, count);
841 this_len = min(max_len, this_len);
842
843 retval = access_remote_vm(mm, (mm->env_start + src),
844 page, this_len, 0);
845
846 if (retval <= 0) {
847 ret = retval;
848 break;
849 }
850
851 if (copy_to_user(buf, page, retval)) {
852 ret = -EFAULT;
853 break;
854 }
855
856 ret += retval;
857 src += retval;
858 buf += retval;
859 count -= retval;
860 }
861 *ppos = src;
862 mmput(mm);
863
864 free:
865 free_page((unsigned long) page);
866 return ret;
867 }
868
869 static const struct file_operations proc_environ_operations = {
870 .open = environ_open,
871 .read = environ_read,
872 .llseek = generic_file_llseek,
873 .release = mem_release,
874 };
875
876 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
877 size_t count, loff_t *ppos)
878 {
879 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
880 char buffer[PROC_NUMBUF];
881 size_t len;
882 int oom_adjust = OOM_DISABLE;
883 unsigned long flags;
884
885 if (!task)
886 return -ESRCH;
887
888 if (lock_task_sighand(task, &flags)) {
889 oom_adjust = task->signal->oom_adj;
890 unlock_task_sighand(task, &flags);
891 }
892
893 put_task_struct(task);
894
895 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
896
897 return simple_read_from_buffer(buf, count, ppos, buffer, len);
898 }
899
900 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
901 size_t count, loff_t *ppos)
902 {
903 struct task_struct *task;
904 char buffer[PROC_NUMBUF];
905 int oom_adjust;
906 unsigned long flags;
907 int err;
908
909 memset(buffer, 0, sizeof(buffer));
910 if (count > sizeof(buffer) - 1)
911 count = sizeof(buffer) - 1;
912 if (copy_from_user(buffer, buf, count)) {
913 err = -EFAULT;
914 goto out;
915 }
916
917 err = kstrtoint(strstrip(buffer), 0, &oom_adjust);
918 if (err)
919 goto out;
920 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
921 oom_adjust != OOM_DISABLE) {
922 err = -EINVAL;
923 goto out;
924 }
925
926 task = get_proc_task(file->f_path.dentry->d_inode);
927 if (!task) {
928 err = -ESRCH;
929 goto out;
930 }
931
932 task_lock(task);
933 if (!task->mm) {
934 err = -EINVAL;
935 goto err_task_lock;
936 }
937
938 if (!lock_task_sighand(task, &flags)) {
939 err = -ESRCH;
940 goto err_task_lock;
941 }
942
943 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
944 err = -EACCES;
945 goto err_sighand;
946 }
947
948 /*
949 * Warn that /proc/pid/oom_adj is deprecated, see
950 * Documentation/feature-removal-schedule.txt.
951 */
952 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
953 current->comm, task_pid_nr(current), task_pid_nr(task),
954 task_pid_nr(task));
955 task->signal->oom_adj = oom_adjust;
956 /*
957 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
958 * value is always attainable.
959 */
960 if (task->signal->oom_adj == OOM_ADJUST_MAX)
961 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
962 else
963 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
964 -OOM_DISABLE;
965 trace_oom_score_adj_update(task);
966 err_sighand:
967 unlock_task_sighand(task, &flags);
968 err_task_lock:
969 task_unlock(task);
970 put_task_struct(task);
971 out:
972 return err < 0 ? err : count;
973 }
974
975 static const struct file_operations proc_oom_adjust_operations = {
976 .read = oom_adjust_read,
977 .write = oom_adjust_write,
978 .llseek = generic_file_llseek,
979 };
980
981 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
982 size_t count, loff_t *ppos)
983 {
984 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
985 char buffer[PROC_NUMBUF];
986 int oom_score_adj = OOM_SCORE_ADJ_MIN;
987 unsigned long flags;
988 size_t len;
989
990 if (!task)
991 return -ESRCH;
992 if (lock_task_sighand(task, &flags)) {
993 oom_score_adj = task->signal->oom_score_adj;
994 unlock_task_sighand(task, &flags);
995 }
996 put_task_struct(task);
997 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
998 return simple_read_from_buffer(buf, count, ppos, buffer, len);
999 }
1000
1001 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1002 size_t count, loff_t *ppos)
1003 {
1004 struct task_struct *task;
1005 char buffer[PROC_NUMBUF];
1006 unsigned long flags;
1007 int oom_score_adj;
1008 int err;
1009
1010 memset(buffer, 0, sizeof(buffer));
1011 if (count > sizeof(buffer) - 1)
1012 count = sizeof(buffer) - 1;
1013 if (copy_from_user(buffer, buf, count)) {
1014 err = -EFAULT;
1015 goto out;
1016 }
1017
1018 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1019 if (err)
1020 goto out;
1021 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1022 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1023 err = -EINVAL;
1024 goto out;
1025 }
1026
1027 task = get_proc_task(file->f_path.dentry->d_inode);
1028 if (!task) {
1029 err = -ESRCH;
1030 goto out;
1031 }
1032
1033 task_lock(task);
1034 if (!task->mm) {
1035 err = -EINVAL;
1036 goto err_task_lock;
1037 }
1038
1039 if (!lock_task_sighand(task, &flags)) {
1040 err = -ESRCH;
1041 goto err_task_lock;
1042 }
1043
1044 if (oom_score_adj < task->signal->oom_score_adj_min &&
1045 !capable(CAP_SYS_RESOURCE)) {
1046 err = -EACCES;
1047 goto err_sighand;
1048 }
1049
1050 task->signal->oom_score_adj = oom_score_adj;
1051 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1052 task->signal->oom_score_adj_min = oom_score_adj;
1053 trace_oom_score_adj_update(task);
1054 /*
1055 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1056 * always attainable.
1057 */
1058 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1059 task->signal->oom_adj = OOM_DISABLE;
1060 else
1061 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1062 OOM_SCORE_ADJ_MAX;
1063 err_sighand:
1064 unlock_task_sighand(task, &flags);
1065 err_task_lock:
1066 task_unlock(task);
1067 put_task_struct(task);
1068 out:
1069 return err < 0 ? err : count;
1070 }
1071
1072 static const struct file_operations proc_oom_score_adj_operations = {
1073 .read = oom_score_adj_read,
1074 .write = oom_score_adj_write,
1075 .llseek = default_llseek,
1076 };
1077
1078 #ifdef CONFIG_AUDITSYSCALL
1079 #define TMPBUFLEN 21
1080 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1081 size_t count, loff_t *ppos)
1082 {
1083 struct inode * inode = file->f_path.dentry->d_inode;
1084 struct task_struct *task = get_proc_task(inode);
1085 ssize_t length;
1086 char tmpbuf[TMPBUFLEN];
1087
1088 if (!task)
1089 return -ESRCH;
1090 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1091 from_kuid(file->f_cred->user_ns,
1092 audit_get_loginuid(task)));
1093 put_task_struct(task);
1094 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1095 }
1096
1097 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1098 size_t count, loff_t *ppos)
1099 {
1100 struct inode * inode = file->f_path.dentry->d_inode;
1101 char *page, *tmp;
1102 ssize_t length;
1103 uid_t loginuid;
1104 kuid_t kloginuid;
1105
1106 rcu_read_lock();
1107 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1108 rcu_read_unlock();
1109 return -EPERM;
1110 }
1111 rcu_read_unlock();
1112
1113 if (count >= PAGE_SIZE)
1114 count = PAGE_SIZE - 1;
1115
1116 if (*ppos != 0) {
1117 /* No partial writes. */
1118 return -EINVAL;
1119 }
1120 page = (char*)__get_free_page(GFP_TEMPORARY);
1121 if (!page)
1122 return -ENOMEM;
1123 length = -EFAULT;
1124 if (copy_from_user(page, buf, count))
1125 goto out_free_page;
1126
1127 page[count] = '\0';
1128 loginuid = simple_strtoul(page, &tmp, 10);
1129 if (tmp == page) {
1130 length = -EINVAL;
1131 goto out_free_page;
1132
1133 }
1134 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1135 if (!uid_valid(kloginuid)) {
1136 length = -EINVAL;
1137 goto out_free_page;
1138 }
1139
1140 length = audit_set_loginuid(kloginuid);
1141 if (likely(length == 0))
1142 length = count;
1143
1144 out_free_page:
1145 free_page((unsigned long) page);
1146 return length;
1147 }
1148
1149 static const struct file_operations proc_loginuid_operations = {
1150 .read = proc_loginuid_read,
1151 .write = proc_loginuid_write,
1152 .llseek = generic_file_llseek,
1153 };
1154
1155 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1156 size_t count, loff_t *ppos)
1157 {
1158 struct inode * inode = file->f_path.dentry->d_inode;
1159 struct task_struct *task = get_proc_task(inode);
1160 ssize_t length;
1161 char tmpbuf[TMPBUFLEN];
1162
1163 if (!task)
1164 return -ESRCH;
1165 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1166 audit_get_sessionid(task));
1167 put_task_struct(task);
1168 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1169 }
1170
1171 static const struct file_operations proc_sessionid_operations = {
1172 .read = proc_sessionid_read,
1173 .llseek = generic_file_llseek,
1174 };
1175 #endif
1176
1177 #ifdef CONFIG_FAULT_INJECTION
1178 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1179 size_t count, loff_t *ppos)
1180 {
1181 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1182 char buffer[PROC_NUMBUF];
1183 size_t len;
1184 int make_it_fail;
1185
1186 if (!task)
1187 return -ESRCH;
1188 make_it_fail = task->make_it_fail;
1189 put_task_struct(task);
1190
1191 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1192
1193 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1194 }
1195
1196 static ssize_t proc_fault_inject_write(struct file * file,
1197 const char __user * buf, size_t count, loff_t *ppos)
1198 {
1199 struct task_struct *task;
1200 char buffer[PROC_NUMBUF], *end;
1201 int make_it_fail;
1202
1203 if (!capable(CAP_SYS_RESOURCE))
1204 return -EPERM;
1205 memset(buffer, 0, sizeof(buffer));
1206 if (count > sizeof(buffer) - 1)
1207 count = sizeof(buffer) - 1;
1208 if (copy_from_user(buffer, buf, count))
1209 return -EFAULT;
1210 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1211 if (*end)
1212 return -EINVAL;
1213 task = get_proc_task(file->f_dentry->d_inode);
1214 if (!task)
1215 return -ESRCH;
1216 task->make_it_fail = make_it_fail;
1217 put_task_struct(task);
1218
1219 return count;
1220 }
1221
1222 static const struct file_operations proc_fault_inject_operations = {
1223 .read = proc_fault_inject_read,
1224 .write = proc_fault_inject_write,
1225 .llseek = generic_file_llseek,
1226 };
1227 #endif
1228
1229
1230 #ifdef CONFIG_SCHED_DEBUG
1231 /*
1232 * Print out various scheduling related per-task fields:
1233 */
1234 static int sched_show(struct seq_file *m, void *v)
1235 {
1236 struct inode *inode = m->private;
1237 struct task_struct *p;
1238
1239 p = get_proc_task(inode);
1240 if (!p)
1241 return -ESRCH;
1242 proc_sched_show_task(p, m);
1243
1244 put_task_struct(p);
1245
1246 return 0;
1247 }
1248
1249 static ssize_t
1250 sched_write(struct file *file, const char __user *buf,
1251 size_t count, loff_t *offset)
1252 {
1253 struct inode *inode = file->f_path.dentry->d_inode;
1254 struct task_struct *p;
1255
1256 p = get_proc_task(inode);
1257 if (!p)
1258 return -ESRCH;
1259 proc_sched_set_task(p);
1260
1261 put_task_struct(p);
1262
1263 return count;
1264 }
1265
1266 static int sched_open(struct inode *inode, struct file *filp)
1267 {
1268 return single_open(filp, sched_show, inode);
1269 }
1270
1271 static const struct file_operations proc_pid_sched_operations = {
1272 .open = sched_open,
1273 .read = seq_read,
1274 .write = sched_write,
1275 .llseek = seq_lseek,
1276 .release = single_release,
1277 };
1278
1279 #endif
1280
1281 #ifdef CONFIG_SCHED_AUTOGROUP
1282 /*
1283 * Print out autogroup related information:
1284 */
1285 static int sched_autogroup_show(struct seq_file *m, void *v)
1286 {
1287 struct inode *inode = m->private;
1288 struct task_struct *p;
1289
1290 p = get_proc_task(inode);
1291 if (!p)
1292 return -ESRCH;
1293 proc_sched_autogroup_show_task(p, m);
1294
1295 put_task_struct(p);
1296
1297 return 0;
1298 }
1299
1300 static ssize_t
1301 sched_autogroup_write(struct file *file, const char __user *buf,
1302 size_t count, loff_t *offset)
1303 {
1304 struct inode *inode = file->f_path.dentry->d_inode;
1305 struct task_struct *p;
1306 char buffer[PROC_NUMBUF];
1307 int nice;
1308 int err;
1309
1310 memset(buffer, 0, sizeof(buffer));
1311 if (count > sizeof(buffer) - 1)
1312 count = sizeof(buffer) - 1;
1313 if (copy_from_user(buffer, buf, count))
1314 return -EFAULT;
1315
1316 err = kstrtoint(strstrip(buffer), 0, &nice);
1317 if (err < 0)
1318 return err;
1319
1320 p = get_proc_task(inode);
1321 if (!p)
1322 return -ESRCH;
1323
1324 err = proc_sched_autogroup_set_nice(p, nice);
1325 if (err)
1326 count = err;
1327
1328 put_task_struct(p);
1329
1330 return count;
1331 }
1332
1333 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1334 {
1335 int ret;
1336
1337 ret = single_open(filp, sched_autogroup_show, NULL);
1338 if (!ret) {
1339 struct seq_file *m = filp->private_data;
1340
1341 m->private = inode;
1342 }
1343 return ret;
1344 }
1345
1346 static const struct file_operations proc_pid_sched_autogroup_operations = {
1347 .open = sched_autogroup_open,
1348 .read = seq_read,
1349 .write = sched_autogroup_write,
1350 .llseek = seq_lseek,
1351 .release = single_release,
1352 };
1353
1354 #endif /* CONFIG_SCHED_AUTOGROUP */
1355
1356 static ssize_t comm_write(struct file *file, const char __user *buf,
1357 size_t count, loff_t *offset)
1358 {
1359 struct inode *inode = file->f_path.dentry->d_inode;
1360 struct task_struct *p;
1361 char buffer[TASK_COMM_LEN];
1362
1363 memset(buffer, 0, sizeof(buffer));
1364 if (count > sizeof(buffer) - 1)
1365 count = sizeof(buffer) - 1;
1366 if (copy_from_user(buffer, buf, count))
1367 return -EFAULT;
1368
1369 p = get_proc_task(inode);
1370 if (!p)
1371 return -ESRCH;
1372
1373 if (same_thread_group(current, p))
1374 set_task_comm(p, buffer);
1375 else
1376 count = -EINVAL;
1377
1378 put_task_struct(p);
1379
1380 return count;
1381 }
1382
1383 static int comm_show(struct seq_file *m, void *v)
1384 {
1385 struct inode *inode = m->private;
1386 struct task_struct *p;
1387
1388 p = get_proc_task(inode);
1389 if (!p)
1390 return -ESRCH;
1391
1392 task_lock(p);
1393 seq_printf(m, "%s\n", p->comm);
1394 task_unlock(p);
1395
1396 put_task_struct(p);
1397
1398 return 0;
1399 }
1400
1401 static int comm_open(struct inode *inode, struct file *filp)
1402 {
1403 return single_open(filp, comm_show, inode);
1404 }
1405
1406 static const struct file_operations proc_pid_set_comm_operations = {
1407 .open = comm_open,
1408 .read = seq_read,
1409 .write = comm_write,
1410 .llseek = seq_lseek,
1411 .release = single_release,
1412 };
1413
1414 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1415 {
1416 struct task_struct *task;
1417 struct mm_struct *mm;
1418 struct file *exe_file;
1419
1420 task = get_proc_task(dentry->d_inode);
1421 if (!task)
1422 return -ENOENT;
1423 mm = get_task_mm(task);
1424 put_task_struct(task);
1425 if (!mm)
1426 return -ENOENT;
1427 exe_file = get_mm_exe_file(mm);
1428 mmput(mm);
1429 if (exe_file) {
1430 *exe_path = exe_file->f_path;
1431 path_get(&exe_file->f_path);
1432 fput(exe_file);
1433 return 0;
1434 } else
1435 return -ENOENT;
1436 }
1437
1438 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1439 {
1440 struct inode *inode = dentry->d_inode;
1441 struct path path;
1442 int error = -EACCES;
1443
1444 /* Are we allowed to snoop on the tasks file descriptors? */
1445 if (!proc_fd_access_allowed(inode))
1446 goto out;
1447
1448 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1449 if (error)
1450 goto out;
1451
1452 nd_jump_link(nd, &path);
1453 return NULL;
1454 out:
1455 return ERR_PTR(error);
1456 }
1457
1458 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1459 {
1460 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1461 char *pathname;
1462 int len;
1463
1464 if (!tmp)
1465 return -ENOMEM;
1466
1467 pathname = d_path(path, tmp, PAGE_SIZE);
1468 len = PTR_ERR(pathname);
1469 if (IS_ERR(pathname))
1470 goto out;
1471 len = tmp + PAGE_SIZE - 1 - pathname;
1472
1473 if (len > buflen)
1474 len = buflen;
1475 if (copy_to_user(buffer, pathname, len))
1476 len = -EFAULT;
1477 out:
1478 free_page((unsigned long)tmp);
1479 return len;
1480 }
1481
1482 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1483 {
1484 int error = -EACCES;
1485 struct inode *inode = dentry->d_inode;
1486 struct path path;
1487
1488 /* Are we allowed to snoop on the tasks file descriptors? */
1489 if (!proc_fd_access_allowed(inode))
1490 goto out;
1491
1492 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1493 if (error)
1494 goto out;
1495
1496 error = do_proc_readlink(&path, buffer, buflen);
1497 path_put(&path);
1498 out:
1499 return error;
1500 }
1501
1502 const struct inode_operations proc_pid_link_inode_operations = {
1503 .readlink = proc_pid_readlink,
1504 .follow_link = proc_pid_follow_link,
1505 .setattr = proc_setattr,
1506 };
1507
1508
1509 /* building an inode */
1510
1511 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1512 {
1513 struct inode * inode;
1514 struct proc_inode *ei;
1515 const struct cred *cred;
1516
1517 /* We need a new inode */
1518
1519 inode = new_inode(sb);
1520 if (!inode)
1521 goto out;
1522
1523 /* Common stuff */
1524 ei = PROC_I(inode);
1525 inode->i_ino = get_next_ino();
1526 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1527 inode->i_op = &proc_def_inode_operations;
1528
1529 /*
1530 * grab the reference to task.
1531 */
1532 ei->pid = get_task_pid(task, PIDTYPE_PID);
1533 if (!ei->pid)
1534 goto out_unlock;
1535
1536 if (task_dumpable(task)) {
1537 rcu_read_lock();
1538 cred = __task_cred(task);
1539 inode->i_uid = cred->euid;
1540 inode->i_gid = cred->egid;
1541 rcu_read_unlock();
1542 }
1543 security_task_to_inode(task, inode);
1544
1545 out:
1546 return inode;
1547
1548 out_unlock:
1549 iput(inode);
1550 return NULL;
1551 }
1552
1553 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1554 {
1555 struct inode *inode = dentry->d_inode;
1556 struct task_struct *task;
1557 const struct cred *cred;
1558 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
1559
1560 generic_fillattr(inode, stat);
1561
1562 rcu_read_lock();
1563 stat->uid = GLOBAL_ROOT_UID;
1564 stat->gid = GLOBAL_ROOT_GID;
1565 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1566 if (task) {
1567 if (!has_pid_permissions(pid, task, 2)) {
1568 rcu_read_unlock();
1569 /*
1570 * This doesn't prevent learning whether PID exists,
1571 * it only makes getattr() consistent with readdir().
1572 */
1573 return -ENOENT;
1574 }
1575 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1576 task_dumpable(task)) {
1577 cred = __task_cred(task);
1578 stat->uid = cred->euid;
1579 stat->gid = cred->egid;
1580 }
1581 }
1582 rcu_read_unlock();
1583 return 0;
1584 }
1585
1586 /* dentry stuff */
1587
1588 /*
1589 * Exceptional case: normally we are not allowed to unhash a busy
1590 * directory. In this case, however, we can do it - no aliasing problems
1591 * due to the way we treat inodes.
1592 *
1593 * Rewrite the inode's ownerships here because the owning task may have
1594 * performed a setuid(), etc.
1595 *
1596 * Before the /proc/pid/status file was created the only way to read
1597 * the effective uid of a /process was to stat /proc/pid. Reading
1598 * /proc/pid/status is slow enough that procps and other packages
1599 * kept stating /proc/pid. To keep the rules in /proc simple I have
1600 * made this apply to all per process world readable and executable
1601 * directories.
1602 */
1603 int pid_revalidate(struct dentry *dentry, unsigned int flags)
1604 {
1605 struct inode *inode;
1606 struct task_struct *task;
1607 const struct cred *cred;
1608
1609 if (flags & LOOKUP_RCU)
1610 return -ECHILD;
1611
1612 inode = dentry->d_inode;
1613 task = get_proc_task(inode);
1614
1615 if (task) {
1616 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1617 task_dumpable(task)) {
1618 rcu_read_lock();
1619 cred = __task_cred(task);
1620 inode->i_uid = cred->euid;
1621 inode->i_gid = cred->egid;
1622 rcu_read_unlock();
1623 } else {
1624 inode->i_uid = GLOBAL_ROOT_UID;
1625 inode->i_gid = GLOBAL_ROOT_GID;
1626 }
1627 inode->i_mode &= ~(S_ISUID | S_ISGID);
1628 security_task_to_inode(task, inode);
1629 put_task_struct(task);
1630 return 1;
1631 }
1632 d_drop(dentry);
1633 return 0;
1634 }
1635
1636 const struct dentry_operations pid_dentry_operations =
1637 {
1638 .d_revalidate = pid_revalidate,
1639 .d_delete = pid_delete_dentry,
1640 };
1641
1642 /* Lookups */
1643
1644 /*
1645 * Fill a directory entry.
1646 *
1647 * If possible create the dcache entry and derive our inode number and
1648 * file type from dcache entry.
1649 *
1650 * Since all of the proc inode numbers are dynamically generated, the inode
1651 * numbers do not exist until the inode is cache. This means creating the
1652 * the dcache entry in readdir is necessary to keep the inode numbers
1653 * reported by readdir in sync with the inode numbers reported
1654 * by stat.
1655 */
1656 int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1657 const char *name, int len,
1658 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1659 {
1660 struct dentry *child, *dir = filp->f_path.dentry;
1661 struct inode *inode;
1662 struct qstr qname;
1663 ino_t ino = 0;
1664 unsigned type = DT_UNKNOWN;
1665
1666 qname.name = name;
1667 qname.len = len;
1668 qname.hash = full_name_hash(name, len);
1669
1670 child = d_lookup(dir, &qname);
1671 if (!child) {
1672 struct dentry *new;
1673 new = d_alloc(dir, &qname);
1674 if (new) {
1675 child = instantiate(dir->d_inode, new, task, ptr);
1676 if (child)
1677 dput(new);
1678 else
1679 child = new;
1680 }
1681 }
1682 if (!child || IS_ERR(child) || !child->d_inode)
1683 goto end_instantiate;
1684 inode = child->d_inode;
1685 if (inode) {
1686 ino = inode->i_ino;
1687 type = inode->i_mode >> 12;
1688 }
1689 dput(child);
1690 end_instantiate:
1691 if (!ino)
1692 ino = find_inode_number(dir, &qname);
1693 if (!ino)
1694 ino = 1;
1695 return filldir(dirent, name, len, filp->f_pos, ino, type);
1696 }
1697
1698 #ifdef CONFIG_CHECKPOINT_RESTORE
1699
1700 /*
1701 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1702 * which represent vma start and end addresses.
1703 */
1704 static int dname_to_vma_addr(struct dentry *dentry,
1705 unsigned long *start, unsigned long *end)
1706 {
1707 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
1708 return -EINVAL;
1709
1710 return 0;
1711 }
1712
1713 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1714 {
1715 unsigned long vm_start, vm_end;
1716 bool exact_vma_exists = false;
1717 struct mm_struct *mm = NULL;
1718 struct task_struct *task;
1719 const struct cred *cred;
1720 struct inode *inode;
1721 int status = 0;
1722
1723 if (flags & LOOKUP_RCU)
1724 return -ECHILD;
1725
1726 if (!capable(CAP_SYS_ADMIN)) {
1727 status = -EACCES;
1728 goto out_notask;
1729 }
1730
1731 inode = dentry->d_inode;
1732 task = get_proc_task(inode);
1733 if (!task)
1734 goto out_notask;
1735
1736 mm = mm_access(task, PTRACE_MODE_READ);
1737 if (IS_ERR_OR_NULL(mm))
1738 goto out;
1739
1740 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1741 down_read(&mm->mmap_sem);
1742 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1743 up_read(&mm->mmap_sem);
1744 }
1745
1746 mmput(mm);
1747
1748 if (exact_vma_exists) {
1749 if (task_dumpable(task)) {
1750 rcu_read_lock();
1751 cred = __task_cred(task);
1752 inode->i_uid = cred->euid;
1753 inode->i_gid = cred->egid;
1754 rcu_read_unlock();
1755 } else {
1756 inode->i_uid = GLOBAL_ROOT_UID;
1757 inode->i_gid = GLOBAL_ROOT_GID;
1758 }
1759 security_task_to_inode(task, inode);
1760 status = 1;
1761 }
1762
1763 out:
1764 put_task_struct(task);
1765
1766 out_notask:
1767 if (status <= 0)
1768 d_drop(dentry);
1769
1770 return status;
1771 }
1772
1773 static const struct dentry_operations tid_map_files_dentry_operations = {
1774 .d_revalidate = map_files_d_revalidate,
1775 .d_delete = pid_delete_dentry,
1776 };
1777
1778 static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
1779 {
1780 unsigned long vm_start, vm_end;
1781 struct vm_area_struct *vma;
1782 struct task_struct *task;
1783 struct mm_struct *mm;
1784 int rc;
1785
1786 rc = -ENOENT;
1787 task = get_proc_task(dentry->d_inode);
1788 if (!task)
1789 goto out;
1790
1791 mm = get_task_mm(task);
1792 put_task_struct(task);
1793 if (!mm)
1794 goto out;
1795
1796 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
1797 if (rc)
1798 goto out_mmput;
1799
1800 down_read(&mm->mmap_sem);
1801 vma = find_exact_vma(mm, vm_start, vm_end);
1802 if (vma && vma->vm_file) {
1803 *path = vma->vm_file->f_path;
1804 path_get(path);
1805 rc = 0;
1806 }
1807 up_read(&mm->mmap_sem);
1808
1809 out_mmput:
1810 mmput(mm);
1811 out:
1812 return rc;
1813 }
1814
1815 struct map_files_info {
1816 fmode_t mode;
1817 unsigned long len;
1818 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
1819 };
1820
1821 static struct dentry *
1822 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
1823 struct task_struct *task, const void *ptr)
1824 {
1825 fmode_t mode = (fmode_t)(unsigned long)ptr;
1826 struct proc_inode *ei;
1827 struct inode *inode;
1828
1829 inode = proc_pid_make_inode(dir->i_sb, task);
1830 if (!inode)
1831 return ERR_PTR(-ENOENT);
1832
1833 ei = PROC_I(inode);
1834 ei->op.proc_get_link = proc_map_files_get_link;
1835
1836 inode->i_op = &proc_pid_link_inode_operations;
1837 inode->i_size = 64;
1838 inode->i_mode = S_IFLNK;
1839
1840 if (mode & FMODE_READ)
1841 inode->i_mode |= S_IRUSR;
1842 if (mode & FMODE_WRITE)
1843 inode->i_mode |= S_IWUSR;
1844
1845 d_set_d_op(dentry, &tid_map_files_dentry_operations);
1846 d_add(dentry, inode);
1847
1848 return NULL;
1849 }
1850
1851 static struct dentry *proc_map_files_lookup(struct inode *dir,
1852 struct dentry *dentry, unsigned int flags)
1853 {
1854 unsigned long vm_start, vm_end;
1855 struct vm_area_struct *vma;
1856 struct task_struct *task;
1857 struct dentry *result;
1858 struct mm_struct *mm;
1859
1860 result = ERR_PTR(-EACCES);
1861 if (!capable(CAP_SYS_ADMIN))
1862 goto out;
1863
1864 result = ERR_PTR(-ENOENT);
1865 task = get_proc_task(dir);
1866 if (!task)
1867 goto out;
1868
1869 result = ERR_PTR(-EACCES);
1870 if (!ptrace_may_access(task, PTRACE_MODE_READ))
1871 goto out_put_task;
1872
1873 result = ERR_PTR(-ENOENT);
1874 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
1875 goto out_put_task;
1876
1877 mm = get_task_mm(task);
1878 if (!mm)
1879 goto out_put_task;
1880
1881 down_read(&mm->mmap_sem);
1882 vma = find_exact_vma(mm, vm_start, vm_end);
1883 if (!vma)
1884 goto out_no_vma;
1885
1886 result = proc_map_files_instantiate(dir, dentry, task,
1887 (void *)(unsigned long)vma->vm_file->f_mode);
1888
1889 out_no_vma:
1890 up_read(&mm->mmap_sem);
1891 mmput(mm);
1892 out_put_task:
1893 put_task_struct(task);
1894 out:
1895 return result;
1896 }
1897
1898 static const struct inode_operations proc_map_files_inode_operations = {
1899 .lookup = proc_map_files_lookup,
1900 .permission = proc_fd_permission,
1901 .setattr = proc_setattr,
1902 };
1903
1904 static int
1905 proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
1906 {
1907 struct dentry *dentry = filp->f_path.dentry;
1908 struct inode *inode = dentry->d_inode;
1909 struct vm_area_struct *vma;
1910 struct task_struct *task;
1911 struct mm_struct *mm;
1912 ino_t ino;
1913 int ret;
1914
1915 ret = -EACCES;
1916 if (!capable(CAP_SYS_ADMIN))
1917 goto out;
1918
1919 ret = -ENOENT;
1920 task = get_proc_task(inode);
1921 if (!task)
1922 goto out;
1923
1924 ret = -EACCES;
1925 if (!ptrace_may_access(task, PTRACE_MODE_READ))
1926 goto out_put_task;
1927
1928 ret = 0;
1929 switch (filp->f_pos) {
1930 case 0:
1931 ino = inode->i_ino;
1932 if (filldir(dirent, ".", 1, 0, ino, DT_DIR) < 0)
1933 goto out_put_task;
1934 filp->f_pos++;
1935 case 1:
1936 ino = parent_ino(dentry);
1937 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1938 goto out_put_task;
1939 filp->f_pos++;
1940 default:
1941 {
1942 unsigned long nr_files, pos, i;
1943 struct flex_array *fa = NULL;
1944 struct map_files_info info;
1945 struct map_files_info *p;
1946
1947 mm = get_task_mm(task);
1948 if (!mm)
1949 goto out_put_task;
1950 down_read(&mm->mmap_sem);
1951
1952 nr_files = 0;
1953
1954 /*
1955 * We need two passes here:
1956 *
1957 * 1) Collect vmas of mapped files with mmap_sem taken
1958 * 2) Release mmap_sem and instantiate entries
1959 *
1960 * otherwise we get lockdep complained, since filldir()
1961 * routine might require mmap_sem taken in might_fault().
1962 */
1963
1964 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
1965 if (vma->vm_file && ++pos > filp->f_pos)
1966 nr_files++;
1967 }
1968
1969 if (nr_files) {
1970 fa = flex_array_alloc(sizeof(info), nr_files,
1971 GFP_KERNEL);
1972 if (!fa || flex_array_prealloc(fa, 0, nr_files,
1973 GFP_KERNEL)) {
1974 ret = -ENOMEM;
1975 if (fa)
1976 flex_array_free(fa);
1977 up_read(&mm->mmap_sem);
1978 mmput(mm);
1979 goto out_put_task;
1980 }
1981 for (i = 0, vma = mm->mmap, pos = 2; vma;
1982 vma = vma->vm_next) {
1983 if (!vma->vm_file)
1984 continue;
1985 if (++pos <= filp->f_pos)
1986 continue;
1987
1988 info.mode = vma->vm_file->f_mode;
1989 info.len = snprintf(info.name,
1990 sizeof(info.name), "%lx-%lx",
1991 vma->vm_start, vma->vm_end);
1992 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
1993 BUG();
1994 }
1995 }
1996 up_read(&mm->mmap_sem);
1997
1998 for (i = 0; i < nr_files; i++) {
1999 p = flex_array_get(fa, i);
2000 ret = proc_fill_cache(filp, dirent, filldir,
2001 p->name, p->len,
2002 proc_map_files_instantiate,
2003 task,
2004 (void *)(unsigned long)p->mode);
2005 if (ret)
2006 break;
2007 filp->f_pos++;
2008 }
2009 if (fa)
2010 flex_array_free(fa);
2011 mmput(mm);
2012 }
2013 }
2014
2015 out_put_task:
2016 put_task_struct(task);
2017 out:
2018 return ret;
2019 }
2020
2021 static const struct file_operations proc_map_files_operations = {
2022 .read = generic_read_dir,
2023 .readdir = proc_map_files_readdir,
2024 .llseek = default_llseek,
2025 };
2026
2027 #endif /* CONFIG_CHECKPOINT_RESTORE */
2028
2029 static struct dentry *proc_pident_instantiate(struct inode *dir,
2030 struct dentry *dentry, struct task_struct *task, const void *ptr)
2031 {
2032 const struct pid_entry *p = ptr;
2033 struct inode *inode;
2034 struct proc_inode *ei;
2035 struct dentry *error = ERR_PTR(-ENOENT);
2036
2037 inode = proc_pid_make_inode(dir->i_sb, task);
2038 if (!inode)
2039 goto out;
2040
2041 ei = PROC_I(inode);
2042 inode->i_mode = p->mode;
2043 if (S_ISDIR(inode->i_mode))
2044 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2045 if (p->iop)
2046 inode->i_op = p->iop;
2047 if (p->fop)
2048 inode->i_fop = p->fop;
2049 ei->op = p->op;
2050 d_set_d_op(dentry, &pid_dentry_operations);
2051 d_add(dentry, inode);
2052 /* Close the race of the process dying before we return the dentry */
2053 if (pid_revalidate(dentry, 0))
2054 error = NULL;
2055 out:
2056 return error;
2057 }
2058
2059 static struct dentry *proc_pident_lookup(struct inode *dir,
2060 struct dentry *dentry,
2061 const struct pid_entry *ents,
2062 unsigned int nents)
2063 {
2064 struct dentry *error;
2065 struct task_struct *task = get_proc_task(dir);
2066 const struct pid_entry *p, *last;
2067
2068 error = ERR_PTR(-ENOENT);
2069
2070 if (!task)
2071 goto out_no_task;
2072
2073 /*
2074 * Yes, it does not scale. And it should not. Don't add
2075 * new entries into /proc/<tgid>/ without very good reasons.
2076 */
2077 last = &ents[nents - 1];
2078 for (p = ents; p <= last; p++) {
2079 if (p->len != dentry->d_name.len)
2080 continue;
2081 if (!memcmp(dentry->d_name.name, p->name, p->len))
2082 break;
2083 }
2084 if (p > last)
2085 goto out;
2086
2087 error = proc_pident_instantiate(dir, dentry, task, p);
2088 out:
2089 put_task_struct(task);
2090 out_no_task:
2091 return error;
2092 }
2093
2094 static int proc_pident_fill_cache(struct file *filp, void *dirent,
2095 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2096 {
2097 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2098 proc_pident_instantiate, task, p);
2099 }
2100
2101 static int proc_pident_readdir(struct file *filp,
2102 void *dirent, filldir_t filldir,
2103 const struct pid_entry *ents, unsigned int nents)
2104 {
2105 int i;
2106 struct dentry *dentry = filp->f_path.dentry;
2107 struct inode *inode = dentry->d_inode;
2108 struct task_struct *task = get_proc_task(inode);
2109 const struct pid_entry *p, *last;
2110 ino_t ino;
2111 int ret;
2112
2113 ret = -ENOENT;
2114 if (!task)
2115 goto out_no_task;
2116
2117 ret = 0;
2118 i = filp->f_pos;
2119 switch (i) {
2120 case 0:
2121 ino = inode->i_ino;
2122 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2123 goto out;
2124 i++;
2125 filp->f_pos++;
2126 /* fall through */
2127 case 1:
2128 ino = parent_ino(dentry);
2129 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2130 goto out;
2131 i++;
2132 filp->f_pos++;
2133 /* fall through */
2134 default:
2135 i -= 2;
2136 if (i >= nents) {
2137 ret = 1;
2138 goto out;
2139 }
2140 p = ents + i;
2141 last = &ents[nents - 1];
2142 while (p <= last) {
2143 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2144 goto out;
2145 filp->f_pos++;
2146 p++;
2147 }
2148 }
2149
2150 ret = 1;
2151 out:
2152 put_task_struct(task);
2153 out_no_task:
2154 return ret;
2155 }
2156
2157 #ifdef CONFIG_SECURITY
2158 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2159 size_t count, loff_t *ppos)
2160 {
2161 struct inode * inode = file->f_path.dentry->d_inode;
2162 char *p = NULL;
2163 ssize_t length;
2164 struct task_struct *task = get_proc_task(inode);
2165
2166 if (!task)
2167 return -ESRCH;
2168
2169 length = security_getprocattr(task,
2170 (char*)file->f_path.dentry->d_name.name,
2171 &p);
2172 put_task_struct(task);
2173 if (length > 0)
2174 length = simple_read_from_buffer(buf, count, ppos, p, length);
2175 kfree(p);
2176 return length;
2177 }
2178
2179 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2180 size_t count, loff_t *ppos)
2181 {
2182 struct inode * inode = file->f_path.dentry->d_inode;
2183 char *page;
2184 ssize_t length;
2185 struct task_struct *task = get_proc_task(inode);
2186
2187 length = -ESRCH;
2188 if (!task)
2189 goto out_no_task;
2190 if (count > PAGE_SIZE)
2191 count = PAGE_SIZE;
2192
2193 /* No partial writes. */
2194 length = -EINVAL;
2195 if (*ppos != 0)
2196 goto out;
2197
2198 length = -ENOMEM;
2199 page = (char*)__get_free_page(GFP_TEMPORARY);
2200 if (!page)
2201 goto out;
2202
2203 length = -EFAULT;
2204 if (copy_from_user(page, buf, count))
2205 goto out_free;
2206
2207 /* Guard against adverse ptrace interaction */
2208 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2209 if (length < 0)
2210 goto out_free;
2211
2212 length = security_setprocattr(task,
2213 (char*)file->f_path.dentry->d_name.name,
2214 (void*)page, count);
2215 mutex_unlock(&task->signal->cred_guard_mutex);
2216 out_free:
2217 free_page((unsigned long) page);
2218 out:
2219 put_task_struct(task);
2220 out_no_task:
2221 return length;
2222 }
2223
2224 static const struct file_operations proc_pid_attr_operations = {
2225 .read = proc_pid_attr_read,
2226 .write = proc_pid_attr_write,
2227 .llseek = generic_file_llseek,
2228 };
2229
2230 static const struct pid_entry attr_dir_stuff[] = {
2231 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2232 REG("prev", S_IRUGO, proc_pid_attr_operations),
2233 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2234 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2235 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2236 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2237 };
2238
2239 static int proc_attr_dir_readdir(struct file * filp,
2240 void * dirent, filldir_t filldir)
2241 {
2242 return proc_pident_readdir(filp,dirent,filldir,
2243 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2244 }
2245
2246 static const struct file_operations proc_attr_dir_operations = {
2247 .read = generic_read_dir,
2248 .readdir = proc_attr_dir_readdir,
2249 .llseek = default_llseek,
2250 };
2251
2252 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2253 struct dentry *dentry, unsigned int flags)
2254 {
2255 return proc_pident_lookup(dir, dentry,
2256 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2257 }
2258
2259 static const struct inode_operations proc_attr_dir_inode_operations = {
2260 .lookup = proc_attr_dir_lookup,
2261 .getattr = pid_getattr,
2262 .setattr = proc_setattr,
2263 };
2264
2265 #endif
2266
2267 #ifdef CONFIG_ELF_CORE
2268 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2269 size_t count, loff_t *ppos)
2270 {
2271 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2272 struct mm_struct *mm;
2273 char buffer[PROC_NUMBUF];
2274 size_t len;
2275 int ret;
2276
2277 if (!task)
2278 return -ESRCH;
2279
2280 ret = 0;
2281 mm = get_task_mm(task);
2282 if (mm) {
2283 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2284 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2285 MMF_DUMP_FILTER_SHIFT));
2286 mmput(mm);
2287 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2288 }
2289
2290 put_task_struct(task);
2291
2292 return ret;
2293 }
2294
2295 static ssize_t proc_coredump_filter_write(struct file *file,
2296 const char __user *buf,
2297 size_t count,
2298 loff_t *ppos)
2299 {
2300 struct task_struct *task;
2301 struct mm_struct *mm;
2302 char buffer[PROC_NUMBUF], *end;
2303 unsigned int val;
2304 int ret;
2305 int i;
2306 unsigned long mask;
2307
2308 ret = -EFAULT;
2309 memset(buffer, 0, sizeof(buffer));
2310 if (count > sizeof(buffer) - 1)
2311 count = sizeof(buffer) - 1;
2312 if (copy_from_user(buffer, buf, count))
2313 goto out_no_task;
2314
2315 ret = -EINVAL;
2316 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2317 if (*end == '\n')
2318 end++;
2319 if (end - buffer == 0)
2320 goto out_no_task;
2321
2322 ret = -ESRCH;
2323 task = get_proc_task(file->f_dentry->d_inode);
2324 if (!task)
2325 goto out_no_task;
2326
2327 ret = end - buffer;
2328 mm = get_task_mm(task);
2329 if (!mm)
2330 goto out_no_mm;
2331
2332 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2333 if (val & mask)
2334 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2335 else
2336 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2337 }
2338
2339 mmput(mm);
2340 out_no_mm:
2341 put_task_struct(task);
2342 out_no_task:
2343 return ret;
2344 }
2345
2346 static const struct file_operations proc_coredump_filter_operations = {
2347 .read = proc_coredump_filter_read,
2348 .write = proc_coredump_filter_write,
2349 .llseek = generic_file_llseek,
2350 };
2351 #endif
2352
2353 /*
2354 * /proc/self:
2355 */
2356 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2357 int buflen)
2358 {
2359 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2360 pid_t tgid = task_tgid_nr_ns(current, ns);
2361 char tmp[PROC_NUMBUF];
2362 if (!tgid)
2363 return -ENOENT;
2364 sprintf(tmp, "%d", tgid);
2365 return vfs_readlink(dentry,buffer,buflen,tmp);
2366 }
2367
2368 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2369 {
2370 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2371 pid_t tgid = task_tgid_nr_ns(current, ns);
2372 char *name = ERR_PTR(-ENOENT);
2373 if (tgid) {
2374 name = __getname();
2375 if (!name)
2376 name = ERR_PTR(-ENOMEM);
2377 else
2378 sprintf(name, "%d", tgid);
2379 }
2380 nd_set_link(nd, name);
2381 return NULL;
2382 }
2383
2384 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2385 void *cookie)
2386 {
2387 char *s = nd_get_link(nd);
2388 if (!IS_ERR(s))
2389 __putname(s);
2390 }
2391
2392 static const struct inode_operations proc_self_inode_operations = {
2393 .readlink = proc_self_readlink,
2394 .follow_link = proc_self_follow_link,
2395 .put_link = proc_self_put_link,
2396 };
2397
2398 /*
2399 * proc base
2400 *
2401 * These are the directory entries in the root directory of /proc
2402 * that properly belong to the /proc filesystem, as they describe
2403 * describe something that is process related.
2404 */
2405 static const struct pid_entry proc_base_stuff[] = {
2406 NOD("self", S_IFLNK|S_IRWXUGO,
2407 &proc_self_inode_operations, NULL, {}),
2408 };
2409
2410 static struct dentry *proc_base_instantiate(struct inode *dir,
2411 struct dentry *dentry, struct task_struct *task, const void *ptr)
2412 {
2413 const struct pid_entry *p = ptr;
2414 struct inode *inode;
2415 struct proc_inode *ei;
2416 struct dentry *error;
2417
2418 /* Allocate the inode */
2419 error = ERR_PTR(-ENOMEM);
2420 inode = new_inode(dir->i_sb);
2421 if (!inode)
2422 goto out;
2423
2424 /* Initialize the inode */
2425 ei = PROC_I(inode);
2426 inode->i_ino = get_next_ino();
2427 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2428
2429 /*
2430 * grab the reference to the task.
2431 */
2432 ei->pid = get_task_pid(task, PIDTYPE_PID);
2433 if (!ei->pid)
2434 goto out_iput;
2435
2436 inode->i_mode = p->mode;
2437 if (S_ISDIR(inode->i_mode))
2438 set_nlink(inode, 2);
2439 if (S_ISLNK(inode->i_mode))
2440 inode->i_size = 64;
2441 if (p->iop)
2442 inode->i_op = p->iop;
2443 if (p->fop)
2444 inode->i_fop = p->fop;
2445 ei->op = p->op;
2446 d_add(dentry, inode);
2447 error = NULL;
2448 out:
2449 return error;
2450 out_iput:
2451 iput(inode);
2452 goto out;
2453 }
2454
2455 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2456 {
2457 struct dentry *error;
2458 struct task_struct *task = get_proc_task(dir);
2459 const struct pid_entry *p, *last;
2460
2461 error = ERR_PTR(-ENOENT);
2462
2463 if (!task)
2464 goto out_no_task;
2465
2466 /* Lookup the directory entry */
2467 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2468 for (p = proc_base_stuff; p <= last; p++) {
2469 if (p->len != dentry->d_name.len)
2470 continue;
2471 if (!memcmp(dentry->d_name.name, p->name, p->len))
2472 break;
2473 }
2474 if (p > last)
2475 goto out;
2476
2477 error = proc_base_instantiate(dir, dentry, task, p);
2478
2479 out:
2480 put_task_struct(task);
2481 out_no_task:
2482 return error;
2483 }
2484
2485 static int proc_base_fill_cache(struct file *filp, void *dirent,
2486 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2487 {
2488 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2489 proc_base_instantiate, task, p);
2490 }
2491
2492 #ifdef CONFIG_TASK_IO_ACCOUNTING
2493 static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2494 {
2495 struct task_io_accounting acct = task->ioac;
2496 unsigned long flags;
2497 int result;
2498
2499 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2500 if (result)
2501 return result;
2502
2503 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2504 result = -EACCES;
2505 goto out_unlock;
2506 }
2507
2508 if (whole && lock_task_sighand(task, &flags)) {
2509 struct task_struct *t = task;
2510
2511 task_io_accounting_add(&acct, &task->signal->ioac);
2512 while_each_thread(task, t)
2513 task_io_accounting_add(&acct, &t->ioac);
2514
2515 unlock_task_sighand(task, &flags);
2516 }
2517 result = sprintf(buffer,
2518 "rchar: %llu\n"
2519 "wchar: %llu\n"
2520 "syscr: %llu\n"
2521 "syscw: %llu\n"
2522 "read_bytes: %llu\n"
2523 "write_bytes: %llu\n"
2524 "cancelled_write_bytes: %llu\n",
2525 (unsigned long long)acct.rchar,
2526 (unsigned long long)acct.wchar,
2527 (unsigned long long)acct.syscr,
2528 (unsigned long long)acct.syscw,
2529 (unsigned long long)acct.read_bytes,
2530 (unsigned long long)acct.write_bytes,
2531 (unsigned long long)acct.cancelled_write_bytes);
2532 out_unlock:
2533 mutex_unlock(&task->signal->cred_guard_mutex);
2534 return result;
2535 }
2536
2537 static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2538 {
2539 return do_io_accounting(task, buffer, 0);
2540 }
2541
2542 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2543 {
2544 return do_io_accounting(task, buffer, 1);
2545 }
2546 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2547
2548 #ifdef CONFIG_USER_NS
2549 static int proc_id_map_open(struct inode *inode, struct file *file,
2550 struct seq_operations *seq_ops)
2551 {
2552 struct user_namespace *ns = NULL;
2553 struct task_struct *task;
2554 struct seq_file *seq;
2555 int ret = -EINVAL;
2556
2557 task = get_proc_task(inode);
2558 if (task) {
2559 rcu_read_lock();
2560 ns = get_user_ns(task_cred_xxx(task, user_ns));
2561 rcu_read_unlock();
2562 put_task_struct(task);
2563 }
2564 if (!ns)
2565 goto err;
2566
2567 ret = seq_open(file, seq_ops);
2568 if (ret)
2569 goto err_put_ns;
2570
2571 seq = file->private_data;
2572 seq->private = ns;
2573
2574 return 0;
2575 err_put_ns:
2576 put_user_ns(ns);
2577 err:
2578 return ret;
2579 }
2580
2581 static int proc_id_map_release(struct inode *inode, struct file *file)
2582 {
2583 struct seq_file *seq = file->private_data;
2584 struct user_namespace *ns = seq->private;
2585 put_user_ns(ns);
2586 return seq_release(inode, file);
2587 }
2588
2589 static int proc_uid_map_open(struct inode *inode, struct file *file)
2590 {
2591 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2592 }
2593
2594 static int proc_gid_map_open(struct inode *inode, struct file *file)
2595 {
2596 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2597 }
2598
2599 static int proc_projid_map_open(struct inode *inode, struct file *file)
2600 {
2601 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2602 }
2603
2604 static const struct file_operations proc_uid_map_operations = {
2605 .open = proc_uid_map_open,
2606 .write = proc_uid_map_write,
2607 .read = seq_read,
2608 .llseek = seq_lseek,
2609 .release = proc_id_map_release,
2610 };
2611
2612 static const struct file_operations proc_gid_map_operations = {
2613 .open = proc_gid_map_open,
2614 .write = proc_gid_map_write,
2615 .read = seq_read,
2616 .llseek = seq_lseek,
2617 .release = proc_id_map_release,
2618 };
2619
2620 static const struct file_operations proc_projid_map_operations = {
2621 .open = proc_projid_map_open,
2622 .write = proc_projid_map_write,
2623 .read = seq_read,
2624 .llseek = seq_lseek,
2625 .release = proc_id_map_release,
2626 };
2627 #endif /* CONFIG_USER_NS */
2628
2629 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2630 struct pid *pid, struct task_struct *task)
2631 {
2632 int err = lock_trace(task);
2633 if (!err) {
2634 seq_printf(m, "%08x\n", task->personality);
2635 unlock_trace(task);
2636 }
2637 return err;
2638 }
2639
2640 /*
2641 * Thread groups
2642 */
2643 static const struct file_operations proc_task_operations;
2644 static const struct inode_operations proc_task_inode_operations;
2645
2646 static const struct pid_entry tgid_base_stuff[] = {
2647 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2648 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2649 #ifdef CONFIG_CHECKPOINT_RESTORE
2650 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2651 #endif
2652 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2653 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2654 #ifdef CONFIG_NET
2655 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2656 #endif
2657 REG("environ", S_IRUSR, proc_environ_operations),
2658 INF("auxv", S_IRUSR, proc_pid_auxv),
2659 ONE("status", S_IRUGO, proc_pid_status),
2660 ONE("personality", S_IRUGO, proc_pid_personality),
2661 INF("limits", S_IRUGO, proc_pid_limits),
2662 #ifdef CONFIG_SCHED_DEBUG
2663 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2664 #endif
2665 #ifdef CONFIG_SCHED_AUTOGROUP
2666 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2667 #endif
2668 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2669 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2670 INF("syscall", S_IRUGO, proc_pid_syscall),
2671 #endif
2672 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2673 ONE("stat", S_IRUGO, proc_tgid_stat),
2674 ONE("statm", S_IRUGO, proc_pid_statm),
2675 REG("maps", S_IRUGO, proc_pid_maps_operations),
2676 #ifdef CONFIG_NUMA
2677 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
2678 #endif
2679 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2680 LNK("cwd", proc_cwd_link),
2681 LNK("root", proc_root_link),
2682 LNK("exe", proc_exe_link),
2683 REG("mounts", S_IRUGO, proc_mounts_operations),
2684 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2685 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2686 #ifdef CONFIG_PROC_PAGE_MONITOR
2687 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2688 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
2689 REG("pagemap", S_IRUGO, proc_pagemap_operations),
2690 #endif
2691 #ifdef CONFIG_SECURITY
2692 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2693 #endif
2694 #ifdef CONFIG_KALLSYMS
2695 INF("wchan", S_IRUGO, proc_pid_wchan),
2696 #endif
2697 #ifdef CONFIG_STACKTRACE
2698 ONE("stack", S_IRUGO, proc_pid_stack),
2699 #endif
2700 #ifdef CONFIG_SCHEDSTATS
2701 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2702 #endif
2703 #ifdef CONFIG_LATENCYTOP
2704 REG("latency", S_IRUGO, proc_lstats_operations),
2705 #endif
2706 #ifdef CONFIG_PROC_PID_CPUSET
2707 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2708 #endif
2709 #ifdef CONFIG_CGROUPS
2710 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2711 #endif
2712 INF("oom_score", S_IRUGO, proc_oom_score),
2713 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2714 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2715 #ifdef CONFIG_AUDITSYSCALL
2716 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2717 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2718 #endif
2719 #ifdef CONFIG_FAULT_INJECTION
2720 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2721 #endif
2722 #ifdef CONFIG_ELF_CORE
2723 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2724 #endif
2725 #ifdef CONFIG_TASK_IO_ACCOUNTING
2726 INF("io", S_IRUSR, proc_tgid_io_accounting),
2727 #endif
2728 #ifdef CONFIG_HARDWALL
2729 INF("hardwall", S_IRUGO, proc_pid_hardwall),
2730 #endif
2731 #ifdef CONFIG_USER_NS
2732 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
2733 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
2734 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
2735 #endif
2736 };
2737
2738 static int proc_tgid_base_readdir(struct file * filp,
2739 void * dirent, filldir_t filldir)
2740 {
2741 return proc_pident_readdir(filp,dirent,filldir,
2742 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2743 }
2744
2745 static const struct file_operations proc_tgid_base_operations = {
2746 .read = generic_read_dir,
2747 .readdir = proc_tgid_base_readdir,
2748 .llseek = default_llseek,
2749 };
2750
2751 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
2752 {
2753 return proc_pident_lookup(dir, dentry,
2754 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2755 }
2756
2757 static const struct inode_operations proc_tgid_base_inode_operations = {
2758 .lookup = proc_tgid_base_lookup,
2759 .getattr = pid_getattr,
2760 .setattr = proc_setattr,
2761 .permission = proc_pid_permission,
2762 };
2763
2764 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2765 {
2766 struct dentry *dentry, *leader, *dir;
2767 char buf[PROC_NUMBUF];
2768 struct qstr name;
2769
2770 name.name = buf;
2771 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2772 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2773 if (dentry) {
2774 shrink_dcache_parent(dentry);
2775 d_drop(dentry);
2776 dput(dentry);
2777 }
2778
2779 name.name = buf;
2780 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2781 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2782 if (!leader)
2783 goto out;
2784
2785 name.name = "task";
2786 name.len = strlen(name.name);
2787 dir = d_hash_and_lookup(leader, &name);
2788 if (!dir)
2789 goto out_put_leader;
2790
2791 name.name = buf;
2792 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2793 dentry = d_hash_and_lookup(dir, &name);
2794 if (dentry) {
2795 shrink_dcache_parent(dentry);
2796 d_drop(dentry);
2797 dput(dentry);
2798 }
2799
2800 dput(dir);
2801 out_put_leader:
2802 dput(leader);
2803 out:
2804 return;
2805 }
2806
2807 /**
2808 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2809 * @task: task that should be flushed.
2810 *
2811 * When flushing dentries from proc, one needs to flush them from global
2812 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2813 * in. This call is supposed to do all of this job.
2814 *
2815 * Looks in the dcache for
2816 * /proc/@pid
2817 * /proc/@tgid/task/@pid
2818 * if either directory is present flushes it and all of it'ts children
2819 * from the dcache.
2820 *
2821 * It is safe and reasonable to cache /proc entries for a task until
2822 * that task exits. After that they just clog up the dcache with
2823 * useless entries, possibly causing useful dcache entries to be
2824 * flushed instead. This routine is proved to flush those useless
2825 * dcache entries at process exit time.
2826 *
2827 * NOTE: This routine is just an optimization so it does not guarantee
2828 * that no dcache entries will exist at process exit time it
2829 * just makes it very unlikely that any will persist.
2830 */
2831
2832 void proc_flush_task(struct task_struct *task)
2833 {
2834 int i;
2835 struct pid *pid, *tgid;
2836 struct upid *upid;
2837
2838 pid = task_pid(task);
2839 tgid = task_tgid(task);
2840
2841 for (i = 0; i <= pid->level; i++) {
2842 upid = &pid->numbers[i];
2843 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2844 tgid->numbers[i].nr);
2845 }
2846
2847 upid = &pid->numbers[pid->level];
2848 if (upid->nr == 1)
2849 pid_ns_release_proc(upid->ns);
2850 }
2851
2852 static struct dentry *proc_pid_instantiate(struct inode *dir,
2853 struct dentry * dentry,
2854 struct task_struct *task, const void *ptr)
2855 {
2856 struct dentry *error = ERR_PTR(-ENOENT);
2857 struct inode *inode;
2858
2859 inode = proc_pid_make_inode(dir->i_sb, task);
2860 if (!inode)
2861 goto out;
2862
2863 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2864 inode->i_op = &proc_tgid_base_inode_operations;
2865 inode->i_fop = &proc_tgid_base_operations;
2866 inode->i_flags|=S_IMMUTABLE;
2867
2868 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
2869 ARRAY_SIZE(tgid_base_stuff)));
2870
2871 d_set_d_op(dentry, &pid_dentry_operations);
2872
2873 d_add(dentry, inode);
2874 /* Close the race of the process dying before we return the dentry */
2875 if (pid_revalidate(dentry, 0))
2876 error = NULL;
2877 out:
2878 return error;
2879 }
2880
2881 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
2882 {
2883 struct dentry *result;
2884 struct task_struct *task;
2885 unsigned tgid;
2886 struct pid_namespace *ns;
2887
2888 result = proc_base_lookup(dir, dentry);
2889 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
2890 goto out;
2891
2892 tgid = name_to_int(dentry);
2893 if (tgid == ~0U)
2894 goto out;
2895
2896 ns = dentry->d_sb->s_fs_info;
2897 rcu_read_lock();
2898 task = find_task_by_pid_ns(tgid, ns);
2899 if (task)
2900 get_task_struct(task);
2901 rcu_read_unlock();
2902 if (!task)
2903 goto out;
2904
2905 result = proc_pid_instantiate(dir, dentry, task, NULL);
2906 put_task_struct(task);
2907 out:
2908 return result;
2909 }
2910
2911 /*
2912 * Find the first task with tgid >= tgid
2913 *
2914 */
2915 struct tgid_iter {
2916 unsigned int tgid;
2917 struct task_struct *task;
2918 };
2919 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2920 {
2921 struct pid *pid;
2922
2923 if (iter.task)
2924 put_task_struct(iter.task);
2925 rcu_read_lock();
2926 retry:
2927 iter.task = NULL;
2928 pid = find_ge_pid(iter.tgid, ns);
2929 if (pid) {
2930 iter.tgid = pid_nr_ns(pid, ns);
2931 iter.task = pid_task(pid, PIDTYPE_PID);
2932 /* What we to know is if the pid we have find is the
2933 * pid of a thread_group_leader. Testing for task
2934 * being a thread_group_leader is the obvious thing
2935 * todo but there is a window when it fails, due to
2936 * the pid transfer logic in de_thread.
2937 *
2938 * So we perform the straight forward test of seeing
2939 * if the pid we have found is the pid of a thread
2940 * group leader, and don't worry if the task we have
2941 * found doesn't happen to be a thread group leader.
2942 * As we don't care in the case of readdir.
2943 */
2944 if (!iter.task || !has_group_leader_pid(iter.task)) {
2945 iter.tgid += 1;
2946 goto retry;
2947 }
2948 get_task_struct(iter.task);
2949 }
2950 rcu_read_unlock();
2951 return iter;
2952 }
2953
2954 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
2955
2956 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2957 struct tgid_iter iter)
2958 {
2959 char name[PROC_NUMBUF];
2960 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
2961 return proc_fill_cache(filp, dirent, filldir, name, len,
2962 proc_pid_instantiate, iter.task, NULL);
2963 }
2964
2965 static int fake_filldir(void *buf, const char *name, int namelen,
2966 loff_t offset, u64 ino, unsigned d_type)
2967 {
2968 return 0;
2969 }
2970
2971 /* for the /proc/ directory itself, after non-process stuff has been done */
2972 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2973 {
2974 unsigned int nr;
2975 struct task_struct *reaper;
2976 struct tgid_iter iter;
2977 struct pid_namespace *ns;
2978 filldir_t __filldir;
2979
2980 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
2981 goto out_no_task;
2982 nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2983
2984 reaper = get_proc_task(filp->f_path.dentry->d_inode);
2985 if (!reaper)
2986 goto out_no_task;
2987
2988 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
2989 const struct pid_entry *p = &proc_base_stuff[nr];
2990 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
2991 goto out;
2992 }
2993
2994 ns = filp->f_dentry->d_sb->s_fs_info;
2995 iter.task = NULL;
2996 iter.tgid = filp->f_pos - TGID_OFFSET;
2997 for (iter = next_tgid(ns, iter);
2998 iter.task;
2999 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3000 if (has_pid_permissions(ns, iter.task, 2))
3001 __filldir = filldir;
3002 else
3003 __filldir = fake_filldir;
3004
3005 filp->f_pos = iter.tgid + TGID_OFFSET;
3006 if (proc_pid_fill_cache(filp, dirent, __filldir, iter) < 0) {
3007 put_task_struct(iter.task);
3008 goto out;
3009 }
3010 }
3011 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3012 out:
3013 put_task_struct(reaper);
3014 out_no_task:
3015 return 0;
3016 }
3017
3018 /*
3019 * Tasks
3020 */
3021 static const struct pid_entry tid_base_stuff[] = {
3022 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3023 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3024 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3025 REG("environ", S_IRUSR, proc_environ_operations),
3026 INF("auxv", S_IRUSR, proc_pid_auxv),
3027 ONE("status", S_IRUGO, proc_pid_status),
3028 ONE("personality", S_IRUGO, proc_pid_personality),
3029 INF("limits", S_IRUGO, proc_pid_limits),
3030 #ifdef CONFIG_SCHED_DEBUG
3031 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3032 #endif
3033 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3034 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3035 INF("syscall", S_IRUGO, proc_pid_syscall),
3036 #endif
3037 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3038 ONE("stat", S_IRUGO, proc_tid_stat),
3039 ONE("statm", S_IRUGO, proc_pid_statm),
3040 REG("maps", S_IRUGO, proc_tid_maps_operations),
3041 #ifdef CONFIG_CHECKPOINT_RESTORE
3042 REG("children", S_IRUGO, proc_tid_children_operations),
3043 #endif
3044 #ifdef CONFIG_NUMA
3045 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3046 #endif
3047 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3048 LNK("cwd", proc_cwd_link),
3049 LNK("root", proc_root_link),
3050 LNK("exe", proc_exe_link),
3051 REG("mounts", S_IRUGO, proc_mounts_operations),
3052 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3053 #ifdef CONFIG_PROC_PAGE_MONITOR
3054 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3055 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
3056 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3057 #endif
3058 #ifdef CONFIG_SECURITY
3059 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3060 #endif
3061 #ifdef CONFIG_KALLSYMS
3062 INF("wchan", S_IRUGO, proc_pid_wchan),
3063 #endif
3064 #ifdef CONFIG_STACKTRACE
3065 ONE("stack", S_IRUGO, proc_pid_stack),
3066 #endif
3067 #ifdef CONFIG_SCHEDSTATS
3068 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3069 #endif
3070 #ifdef CONFIG_LATENCYTOP
3071 REG("latency", S_IRUGO, proc_lstats_operations),
3072 #endif
3073 #ifdef CONFIG_PROC_PID_CPUSET
3074 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3075 #endif
3076 #ifdef CONFIG_CGROUPS
3077 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3078 #endif
3079 INF("oom_score", S_IRUGO, proc_oom_score),
3080 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3081 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3082 #ifdef CONFIG_AUDITSYSCALL
3083 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3084 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3085 #endif
3086 #ifdef CONFIG_FAULT_INJECTION
3087 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3088 #endif
3089 #ifdef CONFIG_TASK_IO_ACCOUNTING
3090 INF("io", S_IRUSR, proc_tid_io_accounting),
3091 #endif
3092 #ifdef CONFIG_HARDWALL
3093 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3094 #endif
3095 #ifdef CONFIG_USER_NS
3096 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3097 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3098 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3099 #endif
3100 };
3101
3102 static int proc_tid_base_readdir(struct file * filp,
3103 void * dirent, filldir_t filldir)
3104 {
3105 return proc_pident_readdir(filp,dirent,filldir,
3106 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3107 }
3108
3109 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3110 {
3111 return proc_pident_lookup(dir, dentry,
3112 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3113 }
3114
3115 static const struct file_operations proc_tid_base_operations = {
3116 .read = generic_read_dir,
3117 .readdir = proc_tid_base_readdir,
3118 .llseek = default_llseek,
3119 };
3120
3121 static const struct inode_operations proc_tid_base_inode_operations = {
3122 .lookup = proc_tid_base_lookup,
3123 .getattr = pid_getattr,
3124 .setattr = proc_setattr,
3125 };
3126
3127 static struct dentry *proc_task_instantiate(struct inode *dir,
3128 struct dentry *dentry, struct task_struct *task, const void *ptr)
3129 {
3130 struct dentry *error = ERR_PTR(-ENOENT);
3131 struct inode *inode;
3132 inode = proc_pid_make_inode(dir->i_sb, task);
3133
3134 if (!inode)
3135 goto out;
3136 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3137 inode->i_op = &proc_tid_base_inode_operations;
3138 inode->i_fop = &proc_tid_base_operations;
3139 inode->i_flags|=S_IMMUTABLE;
3140
3141 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3142 ARRAY_SIZE(tid_base_stuff)));
3143
3144 d_set_d_op(dentry, &pid_dentry_operations);
3145
3146 d_add(dentry, inode);
3147 /* Close the race of the process dying before we return the dentry */
3148 if (pid_revalidate(dentry, 0))
3149 error = NULL;
3150 out:
3151 return error;
3152 }
3153
3154 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3155 {
3156 struct dentry *result = ERR_PTR(-ENOENT);
3157 struct task_struct *task;
3158 struct task_struct *leader = get_proc_task(dir);
3159 unsigned tid;
3160 struct pid_namespace *ns;
3161
3162 if (!leader)
3163 goto out_no_task;
3164
3165 tid = name_to_int(dentry);
3166 if (tid == ~0U)
3167 goto out;
3168
3169 ns = dentry->d_sb->s_fs_info;
3170 rcu_read_lock();
3171 task = find_task_by_pid_ns(tid, ns);
3172 if (task)
3173 get_task_struct(task);
3174 rcu_read_unlock();
3175 if (!task)
3176 goto out;
3177 if (!same_thread_group(leader, task))
3178 goto out_drop_task;
3179
3180 result = proc_task_instantiate(dir, dentry, task, NULL);
3181 out_drop_task:
3182 put_task_struct(task);
3183 out:
3184 put_task_struct(leader);
3185 out_no_task:
3186 return result;
3187 }
3188
3189 /*
3190 * Find the first tid of a thread group to return to user space.
3191 *
3192 * Usually this is just the thread group leader, but if the users
3193 * buffer was too small or there was a seek into the middle of the
3194 * directory we have more work todo.
3195 *
3196 * In the case of a short read we start with find_task_by_pid.
3197 *
3198 * In the case of a seek we start with the leader and walk nr
3199 * threads past it.
3200 */
3201 static struct task_struct *first_tid(struct task_struct *leader,
3202 int tid, int nr, struct pid_namespace *ns)
3203 {
3204 struct task_struct *pos;
3205
3206 rcu_read_lock();
3207 /* Attempt to start with the pid of a thread */
3208 if (tid && (nr > 0)) {
3209 pos = find_task_by_pid_ns(tid, ns);
3210 if (pos && (pos->group_leader == leader))
3211 goto found;
3212 }
3213
3214 /* If nr exceeds the number of threads there is nothing todo */
3215 pos = NULL;
3216 if (nr && nr >= get_nr_threads(leader))
3217 goto out;
3218
3219 /* If we haven't found our starting place yet start
3220 * with the leader and walk nr threads forward.
3221 */
3222 for (pos = leader; nr > 0; --nr) {
3223 pos = next_thread(pos);
3224 if (pos == leader) {
3225 pos = NULL;
3226 goto out;
3227 }
3228 }
3229 found:
3230 get_task_struct(pos);
3231 out:
3232 rcu_read_unlock();
3233 return pos;
3234 }
3235
3236 /*
3237 * Find the next thread in the thread list.
3238 * Return NULL if there is an error or no next thread.
3239 *
3240 * The reference to the input task_struct is released.
3241 */
3242 static struct task_struct *next_tid(struct task_struct *start)
3243 {
3244 struct task_struct *pos = NULL;
3245 rcu_read_lock();
3246 if (pid_alive(start)) {
3247 pos = next_thread(start);
3248 if (thread_group_leader(pos))
3249 pos = NULL;
3250 else
3251 get_task_struct(pos);
3252 }
3253 rcu_read_unlock();
3254 put_task_struct(start);
3255 return pos;
3256 }
3257
3258 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3259 struct task_struct *task, int tid)
3260 {
3261 char name[PROC_NUMBUF];
3262 int len = snprintf(name, sizeof(name), "%d", tid);
3263 return proc_fill_cache(filp, dirent, filldir, name, len,
3264 proc_task_instantiate, task, NULL);
3265 }
3266
3267 /* for the /proc/TGID/task/ directories */
3268 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3269 {
3270 struct dentry *dentry = filp->f_path.dentry;
3271 struct inode *inode = dentry->d_inode;
3272 struct task_struct *leader = NULL;
3273 struct task_struct *task;
3274 int retval = -ENOENT;
3275 ino_t ino;
3276 int tid;
3277 struct pid_namespace *ns;
3278
3279 task = get_proc_task(inode);
3280 if (!task)
3281 goto out_no_task;
3282 rcu_read_lock();
3283 if (pid_alive(task)) {
3284 leader = task->group_leader;
3285 get_task_struct(leader);
3286 }
3287 rcu_read_unlock();
3288 put_task_struct(task);
3289 if (!leader)
3290 goto out_no_task;
3291 retval = 0;
3292
3293 switch ((unsigned long)filp->f_pos) {
3294 case 0:
3295 ino = inode->i_ino;
3296 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3297 goto out;
3298 filp->f_pos++;
3299 /* fall through */
3300 case 1:
3301 ino = parent_ino(dentry);
3302 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3303 goto out;
3304 filp->f_pos++;
3305 /* fall through */
3306 }
3307
3308 /* f_version caches the tgid value that the last readdir call couldn't
3309 * return. lseek aka telldir automagically resets f_version to 0.
3310 */
3311 ns = filp->f_dentry->d_sb->s_fs_info;
3312 tid = (int)filp->f_version;
3313 filp->f_version = 0;
3314 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3315 task;
3316 task = next_tid(task), filp->f_pos++) {
3317 tid = task_pid_nr_ns(task, ns);
3318 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3319 /* returning this tgid failed, save it as the first
3320 * pid for the next readir call */
3321 filp->f_version = (u64)tid;
3322 put_task_struct(task);
3323 break;
3324 }
3325 }
3326 out:
3327 put_task_struct(leader);
3328 out_no_task:
3329 return retval;
3330 }
3331
3332 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3333 {
3334 struct inode *inode = dentry->d_inode;
3335 struct task_struct *p = get_proc_task(inode);
3336 generic_fillattr(inode, stat);
3337
3338 if (p) {
3339 stat->nlink += get_nr_threads(p);
3340 put_task_struct(p);
3341 }
3342
3343 return 0;
3344 }
3345
3346 static const struct inode_operations proc_task_inode_operations = {
3347 .lookup = proc_task_lookup,
3348 .getattr = proc_task_getattr,
3349 .setattr = proc_setattr,
3350 .permission = proc_pid_permission,
3351 };
3352
3353 static const struct file_operations proc_task_operations = {
3354 .read = generic_read_dir,
3355 .readdir = proc_task_readdir,
3356 .llseek = default_llseek,
3357 };
Linux kernel - Deliverables
This page took 0.116095 seconds and 6 git commands to generate.