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FRV: Use generic show_interrupts()
[cris-mirror.git] / fs / proc / base.c
blob5a670c11aeacc85fd767a8383f45d39d6ac6ea7e
1 /*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
48 */
49
50 #include <asm/uaccess.h>
51
52 #include <linux/errno.h>
53 #include <linux/time.h>
54 #include <linux/proc_fs.h>
55 #include <linux/stat.h>
56 #include <linux/task_io_accounting_ops.h>
57 #include <linux/init.h>
58 #include <linux/capability.h>
59 #include <linux/file.h>
60 #include <linux/fdtable.h>
61 #include <linux/string.h>
62 #include <linux/seq_file.h>
63 #include <linux/namei.h>
64 #include <linux/mnt_namespace.h>
65 #include <linux/mm.h>
66 #include <linux/swap.h>
67 #include <linux/rcupdate.h>
68 #include <linux/kallsyms.h>
69 #include <linux/stacktrace.h>
70 #include <linux/resource.h>
71 #include <linux/module.h>
72 #include <linux/mount.h>
73 #include <linux/security.h>
74 #include <linux/ptrace.h>
75 #include <linux/tracehook.h>
76 #include <linux/cgroup.h>
77 #include <linux/cpuset.h>
78 #include <linux/audit.h>
79 #include <linux/poll.h>
80 #include <linux/nsproxy.h>
81 #include <linux/oom.h>
82 #include <linux/elf.h>
83 #include <linux/pid_namespace.h>
84 #include <linux/fs_struct.h>
85 #include <linux/slab.h>
86 #include "internal.h"
87
88 /* NOTE:
89 * Implementing inode permission operations in /proc is almost
90 * certainly an error. Permission checks need to happen during
91 * each system call not at open time. The reason is that most of
92 * what we wish to check for permissions in /proc varies at runtime.
93 *
94 * The classic example of a problem is opening file descriptors
95 * in /proc for a task before it execs a suid executable.
96 */
97
98 struct pid_entry {
99 char *name;
100 int len;
101 mode_t mode;
102 const struct inode_operations *iop;
103 const struct file_operations *fop;
104 union proc_op op;
105 };
106
107 #define NOD(NAME, MODE, IOP, FOP, OP) { \
108 .name = (NAME), \
109 .len = sizeof(NAME) - 1, \
110 .mode = MODE, \
111 .iop = IOP, \
112 .fop = FOP, \
113 .op = OP, \
114 }
115
116 #define DIR(NAME, MODE, iops, fops) \
117 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
118 #define LNK(NAME, get_link) \
119 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
120 &proc_pid_link_inode_operations, NULL, \
121 { .proc_get_link = get_link } )
122 #define REG(NAME, MODE, fops) \
123 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
124 #define INF(NAME, MODE, read) \
125 NOD(NAME, (S_IFREG|(MODE)), \
126 NULL, &proc_info_file_operations, \
127 { .proc_read = read } )
128 #define ONE(NAME, MODE, show) \
129 NOD(NAME, (S_IFREG|(MODE)), \
130 NULL, &proc_single_file_operations, \
131 { .proc_show = show } )
132
133 /*
134 * Count the number of hardlinks for the pid_entry table, excluding the .
135 * and .. links.
136 */
137 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
138 unsigned int n)
139 {
140 unsigned int i;
141 unsigned int count;
142
143 count = 0;
144 for (i = 0; i < n; ++i) {
145 if (S_ISDIR(entries[i].mode))
146 ++count;
147 }
148
149 return count;
150 }
151
152 static int get_task_root(struct task_struct *task, struct path *root)
153 {
154 int result = -ENOENT;
155
156 task_lock(task);
157 if (task->fs) {
158 get_fs_root(task->fs, root);
159 result = 0;
160 }
161 task_unlock(task);
162 return result;
163 }
164
165 static int proc_cwd_link(struct inode *inode, struct path *path)
166 {
167 struct task_struct *task = get_proc_task(inode);
168 int result = -ENOENT;
169
170 if (task) {
171 task_lock(task);
172 if (task->fs) {
173 get_fs_pwd(task->fs, path);
174 result = 0;
175 }
176 task_unlock(task);
177 put_task_struct(task);
178 }
179 return result;
180 }
181
182 static int proc_root_link(struct inode *inode, struct path *path)
183 {
184 struct task_struct *task = get_proc_task(inode);
185 int result = -ENOENT;
186
187 if (task) {
188 result = get_task_root(task, path);
189 put_task_struct(task);
190 }
191 return result;
192 }
193
194 static struct mm_struct *__check_mem_permission(struct task_struct *task)
195 {
196 struct mm_struct *mm;
197
198 mm = get_task_mm(task);
199 if (!mm)
200 return ERR_PTR(-EINVAL);
201
202 /*
203 * A task can always look at itself, in case it chooses
204 * to use system calls instead of load instructions.
205 */
206 if (task == current)
207 return mm;
208
209 /*
210 * If current is actively ptrace'ing, and would also be
211 * permitted to freshly attach with ptrace now, permit it.
212 */
213 if (task_is_stopped_or_traced(task)) {
214 int match;
215 rcu_read_lock();
216 match = (tracehook_tracer_task(task) == current);
217 rcu_read_unlock();
218 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
219 return mm;
220 }
221
222 /*
223 * Noone else is allowed.
224 */
225 mmput(mm);
226 return ERR_PTR(-EPERM);
227 }
228
229 /*
230 * If current may access user memory in @task return a reference to the
231 * corresponding mm, otherwise ERR_PTR.
232 */
233 static struct mm_struct *check_mem_permission(struct task_struct *task)
234 {
235 struct mm_struct *mm;
236 int err;
237
238 /*
239 * Avoid racing if task exec's as we might get a new mm but validate
240 * against old credentials.
241 */
242 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
243 if (err)
244 return ERR_PTR(err);
245
246 mm = __check_mem_permission(task);
247 mutex_unlock(&task->signal->cred_guard_mutex);
248
249 return mm;
250 }
251
252 struct mm_struct *mm_for_maps(struct task_struct *task)
253 {
254 struct mm_struct *mm;
255 int err;
256
257 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
258 if (err)
259 return ERR_PTR(err);
260
261 mm = get_task_mm(task);
262 if (mm && mm != current->mm &&
263 !ptrace_may_access(task, PTRACE_MODE_READ)) {
264 mmput(mm);
265 mm = ERR_PTR(-EACCES);
266 }
267 mutex_unlock(&task->signal->cred_guard_mutex);
268
269 return mm;
270 }
271
272 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
273 {
274 int res = 0;
275 unsigned int len;
276 struct mm_struct *mm = get_task_mm(task);
277 if (!mm)
278 goto out;
279 if (!mm->arg_end)
280 goto out_mm; /* Shh! No looking before we're done */
281
282 len = mm->arg_end - mm->arg_start;
283
284 if (len > PAGE_SIZE)
285 len = PAGE_SIZE;
286
287 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
288
289 // If the nul at the end of args has been overwritten, then
290 // assume application is using setproctitle(3).
291 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
292 len = strnlen(buffer, res);
293 if (len < res) {
294 res = len;
295 } else {
296 len = mm->env_end - mm->env_start;
297 if (len > PAGE_SIZE - res)
298 len = PAGE_SIZE - res;
299 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
300 res = strnlen(buffer, res);
301 }
302 }
303 out_mm:
304 mmput(mm);
305 out:
306 return res;
307 }
308
309 static int proc_pid_auxv(struct task_struct *task, char *buffer)
310 {
311 struct mm_struct *mm = mm_for_maps(task);
312 int res = PTR_ERR(mm);
313 if (mm && !IS_ERR(mm)) {
314 unsigned int nwords = 0;
315 do {
316 nwords += 2;
317 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
318 res = nwords * sizeof(mm->saved_auxv[0]);
319 if (res > PAGE_SIZE)
320 res = PAGE_SIZE;
321 memcpy(buffer, mm->saved_auxv, res);
322 mmput(mm);
323 }
324 return res;
325 }
326
327
328 #ifdef CONFIG_KALLSYMS
329 /*
330 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
331 * Returns the resolved symbol. If that fails, simply return the address.
332 */
333 static int proc_pid_wchan(struct task_struct *task, char *buffer)
334 {
335 unsigned long wchan;
336 char symname[KSYM_NAME_LEN];
337
338 wchan = get_wchan(task);
339
340 if (lookup_symbol_name(wchan, symname) < 0)
341 if (!ptrace_may_access(task, PTRACE_MODE_READ))
342 return 0;
343 else
344 return sprintf(buffer, "%lu", wchan);
345 else
346 return sprintf(buffer, "%s", symname);
347 }
348 #endif /* CONFIG_KALLSYMS */
349
350 static int lock_trace(struct task_struct *task)
351 {
352 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
353 if (err)
354 return err;
355 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
356 mutex_unlock(&task->signal->cred_guard_mutex);
357 return -EPERM;
358 }
359 return 0;
360 }
361
362 static void unlock_trace(struct task_struct *task)
363 {
364 mutex_unlock(&task->signal->cred_guard_mutex);
365 }
366
367 #ifdef CONFIG_STACKTRACE
368
369 #define MAX_STACK_TRACE_DEPTH 64
370
371 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
372 struct pid *pid, struct task_struct *task)
373 {
374 struct stack_trace trace;
375 unsigned long *entries;
376 int err;
377 int i;
378
379 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
380 if (!entries)
381 return -ENOMEM;
382
383 trace.nr_entries = 0;
384 trace.max_entries = MAX_STACK_TRACE_DEPTH;
385 trace.entries = entries;
386 trace.skip = 0;
387
388 err = lock_trace(task);
389 if (!err) {
390 save_stack_trace_tsk(task, &trace);
391
392 for (i = 0; i < trace.nr_entries; i++) {
393 seq_printf(m, "[<%pK>] %pS\n",
394 (void *)entries[i], (void *)entries[i]);
395 }
396 unlock_trace(task);
397 }
398 kfree(entries);
399
400 return err;
401 }
402 #endif
403
404 #ifdef CONFIG_SCHEDSTATS
405 /*
406 * Provides /proc/PID/schedstat
407 */
408 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
409 {
410 return sprintf(buffer, "%llu %llu %lu\n",
411 (unsigned long long)task->se.sum_exec_runtime,
412 (unsigned long long)task->sched_info.run_delay,
413 task->sched_info.pcount);
414 }
415 #endif
416
417 #ifdef CONFIG_LATENCYTOP
418 static int lstats_show_proc(struct seq_file *m, void *v)
419 {
420 int i;
421 struct inode *inode = m->private;
422 struct task_struct *task = get_proc_task(inode);
423
424 if (!task)
425 return -ESRCH;
426 seq_puts(m, "Latency Top version : v0.1\n");
427 for (i = 0; i < 32; i++) {
428 struct latency_record *lr = &task->latency_record[i];
429 if (lr->backtrace[0]) {
430 int q;
431 seq_printf(m, "%i %li %li",
432 lr->count, lr->time, lr->max);
433 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
434 unsigned long bt = lr->backtrace[q];
435 if (!bt)
436 break;
437 if (bt == ULONG_MAX)
438 break;
439 seq_printf(m, " %ps", (void *)bt);
440 }
441 seq_putc(m, '\n');
442 }
443
444 }
445 put_task_struct(task);
446 return 0;
447 }
448
449 static int lstats_open(struct inode *inode, struct file *file)
450 {
451 return single_open(file, lstats_show_proc, inode);
452 }
453
454 static ssize_t lstats_write(struct file *file, const char __user *buf,
455 size_t count, loff_t *offs)
456 {
457 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
458
459 if (!task)
460 return -ESRCH;
461 clear_all_latency_tracing(task);
462 put_task_struct(task);
463
464 return count;
465 }
466
467 static const struct file_operations proc_lstats_operations = {
468 .open = lstats_open,
469 .read = seq_read,
470 .write = lstats_write,
471 .llseek = seq_lseek,
472 .release = single_release,
473 };
474
475 #endif
476
477 static int proc_oom_score(struct task_struct *task, char *buffer)
478 {
479 unsigned long points = 0;
480
481 read_lock(&tasklist_lock);
482 if (pid_alive(task))
483 points = oom_badness(task, NULL, NULL,
484 totalram_pages + total_swap_pages);
485 read_unlock(&tasklist_lock);
486 return sprintf(buffer, "%lu\n", points);
487 }
488
489 struct limit_names {
490 char *name;
491 char *unit;
492 };
493
494 static const struct limit_names lnames[RLIM_NLIMITS] = {
495 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
496 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
497 [RLIMIT_DATA] = {"Max data size", "bytes"},
498 [RLIMIT_STACK] = {"Max stack size", "bytes"},
499 [RLIMIT_CORE] = {"Max core file size", "bytes"},
500 [RLIMIT_RSS] = {"Max resident set", "bytes"},
501 [RLIMIT_NPROC] = {"Max processes", "processes"},
502 [RLIMIT_NOFILE] = {"Max open files", "files"},
503 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
504 [RLIMIT_AS] = {"Max address space", "bytes"},
505 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
506 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
507 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
508 [RLIMIT_NICE] = {"Max nice priority", NULL},
509 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
510 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
511 };
512
513 /* Display limits for a process */
514 static int proc_pid_limits(struct task_struct *task, char *buffer)
515 {
516 unsigned int i;
517 int count = 0;
518 unsigned long flags;
519 char *bufptr = buffer;
520
521 struct rlimit rlim[RLIM_NLIMITS];
522
523 if (!lock_task_sighand(task, &flags))
524 return 0;
525 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
526 unlock_task_sighand(task, &flags);
527
528 /*
529 * print the file header
530 */
531 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
532 "Limit", "Soft Limit", "Hard Limit", "Units");
533
534 for (i = 0; i < RLIM_NLIMITS; i++) {
535 if (rlim[i].rlim_cur == RLIM_INFINITY)
536 count += sprintf(&bufptr[count], "%-25s %-20s ",
537 lnames[i].name, "unlimited");
538 else
539 count += sprintf(&bufptr[count], "%-25s %-20lu ",
540 lnames[i].name, rlim[i].rlim_cur);
541
542 if (rlim[i].rlim_max == RLIM_INFINITY)
543 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
544 else
545 count += sprintf(&bufptr[count], "%-20lu ",
546 rlim[i].rlim_max);
547
548 if (lnames[i].unit)
549 count += sprintf(&bufptr[count], "%-10s\n",
550 lnames[i].unit);
551 else
552 count += sprintf(&bufptr[count], "\n");
553 }
554
555 return count;
556 }
557
558 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
559 static int proc_pid_syscall(struct task_struct *task, char *buffer)
560 {
561 long nr;
562 unsigned long args[6], sp, pc;
563 int res = lock_trace(task);
564 if (res)
565 return res;
566
567 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
568 res = sprintf(buffer, "running\n");
569 else if (nr < 0)
570 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
571 else
572 res = sprintf(buffer,
573 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
574 nr,
575 args[0], args[1], args[2], args[3], args[4], args[5],
576 sp, pc);
577 unlock_trace(task);
578 return res;
579 }
580 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
581
582 /************************************************************************/
583 /* Here the fs part begins */
584 /************************************************************************/
585
586 /* permission checks */
587 static int proc_fd_access_allowed(struct inode *inode)
588 {
589 struct task_struct *task;
590 int allowed = 0;
591 /* Allow access to a task's file descriptors if it is us or we
592 * may use ptrace attach to the process and find out that
593 * information.
594 */
595 task = get_proc_task(inode);
596 if (task) {
597 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
598 put_task_struct(task);
599 }
600 return allowed;
601 }
602
603 static int proc_setattr(struct dentry *dentry, struct iattr *attr)
604 {
605 int error;
606 struct inode *inode = dentry->d_inode;
607
608 if (attr->ia_valid & ATTR_MODE)
609 return -EPERM;
610
611 error = inode_change_ok(inode, attr);
612 if (error)
613 return error;
614
615 if ((attr->ia_valid & ATTR_SIZE) &&
616 attr->ia_size != i_size_read(inode)) {
617 error = vmtruncate(inode, attr->ia_size);
618 if (error)
619 return error;
620 }
621
622 setattr_copy(inode, attr);
623 mark_inode_dirty(inode);
624 return 0;
625 }
626
627 static const struct inode_operations proc_def_inode_operations = {
628 .setattr = proc_setattr,
629 };
630
631 static int mounts_open_common(struct inode *inode, struct file *file,
632 const struct seq_operations *op)
633 {
634 struct task_struct *task = get_proc_task(inode);
635 struct nsproxy *nsp;
636 struct mnt_namespace *ns = NULL;
637 struct path root;
638 struct proc_mounts *p;
639 int ret = -EINVAL;
640
641 if (task) {
642 rcu_read_lock();
643 nsp = task_nsproxy(task);
644 if (nsp) {
645 ns = nsp->mnt_ns;
646 if (ns)
647 get_mnt_ns(ns);
648 }
649 rcu_read_unlock();
650 if (ns && get_task_root(task, &root) == 0)
651 ret = 0;
652 put_task_struct(task);
653 }
654
655 if (!ns)
656 goto err;
657 if (ret)
658 goto err_put_ns;
659
660 ret = -ENOMEM;
661 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
662 if (!p)
663 goto err_put_path;
664
665 file->private_data = &p->m;
666 ret = seq_open(file, op);
667 if (ret)
668 goto err_free;
669
670 p->m.private = p;
671 p->ns = ns;
672 p->root = root;
673 p->event = ns->event;
674
675 return 0;
676
677 err_free:
678 kfree(p);
679 err_put_path:
680 path_put(&root);
681 err_put_ns:
682 put_mnt_ns(ns);
683 err:
684 return ret;
685 }
686
687 static int mounts_release(struct inode *inode, struct file *file)
688 {
689 struct proc_mounts *p = file->private_data;
690 path_put(&p->root);
691 put_mnt_ns(p->ns);
692 return seq_release(inode, file);
693 }
694
695 static unsigned mounts_poll(struct file *file, poll_table *wait)
696 {
697 struct proc_mounts *p = file->private_data;
698 unsigned res = POLLIN | POLLRDNORM;
699
700 poll_wait(file, &p->ns->poll, wait);
701 if (mnt_had_events(p))
702 res |= POLLERR | POLLPRI;
703
704 return res;
705 }
706
707 static int mounts_open(struct inode *inode, struct file *file)
708 {
709 return mounts_open_common(inode, file, &mounts_op);
710 }
711
712 static const struct file_operations proc_mounts_operations = {
713 .open = mounts_open,
714 .read = seq_read,
715 .llseek = seq_lseek,
716 .release = mounts_release,
717 .poll = mounts_poll,
718 };
719
720 static int mountinfo_open(struct inode *inode, struct file *file)
721 {
722 return mounts_open_common(inode, file, &mountinfo_op);
723 }
724
725 static const struct file_operations proc_mountinfo_operations = {
726 .open = mountinfo_open,
727 .read = seq_read,
728 .llseek = seq_lseek,
729 .release = mounts_release,
730 .poll = mounts_poll,
731 };
732
733 static int mountstats_open(struct inode *inode, struct file *file)
734 {
735 return mounts_open_common(inode, file, &mountstats_op);
736 }
737
738 static const struct file_operations proc_mountstats_operations = {
739 .open = mountstats_open,
740 .read = seq_read,
741 .llseek = seq_lseek,
742 .release = mounts_release,
743 };
744
745 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
746
747 static ssize_t proc_info_read(struct file * file, char __user * buf,
748 size_t count, loff_t *ppos)
749 {
750 struct inode * inode = file->f_path.dentry->d_inode;
751 unsigned long page;
752 ssize_t length;
753 struct task_struct *task = get_proc_task(inode);
754
755 length = -ESRCH;
756 if (!task)
757 goto out_no_task;
758
759 if (count > PROC_BLOCK_SIZE)
760 count = PROC_BLOCK_SIZE;
761
762 length = -ENOMEM;
763 if (!(page = __get_free_page(GFP_TEMPORARY)))
764 goto out;
765
766 length = PROC_I(inode)->op.proc_read(task, (char*)page);
767
768 if (length >= 0)
769 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
770 free_page(page);
771 out:
772 put_task_struct(task);
773 out_no_task:
774 return length;
775 }
776
777 static const struct file_operations proc_info_file_operations = {
778 .read = proc_info_read,
779 .llseek = generic_file_llseek,
780 };
781
782 static int proc_single_show(struct seq_file *m, void *v)
783 {
784 struct inode *inode = m->private;
785 struct pid_namespace *ns;
786 struct pid *pid;
787 struct task_struct *task;
788 int ret;
789
790 ns = inode->i_sb->s_fs_info;
791 pid = proc_pid(inode);
792 task = get_pid_task(pid, PIDTYPE_PID);
793 if (!task)
794 return -ESRCH;
795
796 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
797
798 put_task_struct(task);
799 return ret;
800 }
801
802 static int proc_single_open(struct inode *inode, struct file *filp)
803 {
804 return single_open(filp, proc_single_show, inode);
805 }
806
807 static const struct file_operations proc_single_file_operations = {
808 .open = proc_single_open,
809 .read = seq_read,
810 .llseek = seq_lseek,
811 .release = single_release,
812 };
813
814 static int mem_open(struct inode* inode, struct file* file)
815 {
816 file->private_data = (void*)((long)current->self_exec_id);
817 /* OK to pass negative loff_t, we can catch out-of-range */
818 file->f_mode |= FMODE_UNSIGNED_OFFSET;
819 return 0;
820 }
821
822 static ssize_t mem_read(struct file * file, char __user * buf,
823 size_t count, loff_t *ppos)
824 {
825 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
826 char *page;
827 unsigned long src = *ppos;
828 int ret = -ESRCH;
829 struct mm_struct *mm;
830
831 if (!task)
832 goto out_no_task;
833
834 ret = -ENOMEM;
835 page = (char *)__get_free_page(GFP_TEMPORARY);
836 if (!page)
837 goto out;
838
839 mm = check_mem_permission(task);
840 ret = PTR_ERR(mm);
841 if (IS_ERR(mm))
842 goto out_free;
843
844 ret = -EIO;
845
846 if (file->private_data != (void*)((long)current->self_exec_id))
847 goto out_put;
848
849 ret = 0;
850
851 while (count > 0) {
852 int this_len, retval;
853
854 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
855 retval = access_remote_vm(mm, src, page, this_len, 0);
856 if (!retval) {
857 if (!ret)
858 ret = -EIO;
859 break;
860 }
861
862 if (copy_to_user(buf, page, retval)) {
863 ret = -EFAULT;
864 break;
865 }
866
867 ret += retval;
868 src += retval;
869 buf += retval;
870 count -= retval;
871 }
872 *ppos = src;
873
874 out_put:
875 mmput(mm);
876 out_free:
877 free_page((unsigned long) page);
878 out:
879 put_task_struct(task);
880 out_no_task:
881 return ret;
882 }
883
884 static ssize_t mem_write(struct file * file, const char __user *buf,
885 size_t count, loff_t *ppos)
886 {
887 int copied;
888 char *page;
889 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
890 unsigned long dst = *ppos;
891 struct mm_struct *mm;
892
893 copied = -ESRCH;
894 if (!task)
895 goto out_no_task;
896
897 mm = check_mem_permission(task);
898 copied = PTR_ERR(mm);
899 if (IS_ERR(mm))
900 goto out_task;
901
902 copied = -EIO;
903 if (file->private_data != (void *)((long)current->self_exec_id))
904 goto out_mm;
905
906 copied = -ENOMEM;
907 page = (char *)__get_free_page(GFP_TEMPORARY);
908 if (!page)
909 goto out_mm;
910
911 copied = 0;
912 while (count > 0) {
913 int this_len, retval;
914
915 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
916 if (copy_from_user(page, buf, this_len)) {
917 copied = -EFAULT;
918 break;
919 }
920 retval = access_remote_vm(mm, dst, page, this_len, 1);
921 if (!retval) {
922 if (!copied)
923 copied = -EIO;
924 break;
925 }
926 copied += retval;
927 buf += retval;
928 dst += retval;
929 count -= retval;
930 }
931 *ppos = dst;
932 free_page((unsigned long) page);
933 out_mm:
934 mmput(mm);
935 out_task:
936 put_task_struct(task);
937 out_no_task:
938 return copied;
939 }
940
941 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
942 {
943 switch (orig) {
944 case 0:
945 file->f_pos = offset;
946 break;
947 case 1:
948 file->f_pos += offset;
949 break;
950 default:
951 return -EINVAL;
952 }
953 force_successful_syscall_return();
954 return file->f_pos;
955 }
956
957 static const struct file_operations proc_mem_operations = {
958 .llseek = mem_lseek,
959 .read = mem_read,
960 .write = mem_write,
961 .open = mem_open,
962 };
963
964 static ssize_t environ_read(struct file *file, char __user *buf,
965 size_t count, loff_t *ppos)
966 {
967 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
968 char *page;
969 unsigned long src = *ppos;
970 int ret = -ESRCH;
971 struct mm_struct *mm;
972
973 if (!task)
974 goto out_no_task;
975
976 ret = -ENOMEM;
977 page = (char *)__get_free_page(GFP_TEMPORARY);
978 if (!page)
979 goto out;
980
981
982 mm = mm_for_maps(task);
983 ret = PTR_ERR(mm);
984 if (!mm || IS_ERR(mm))
985 goto out_free;
986
987 ret = 0;
988 while (count > 0) {
989 int this_len, retval, max_len;
990
991 this_len = mm->env_end - (mm->env_start + src);
992
993 if (this_len <= 0)
994 break;
995
996 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
997 this_len = (this_len > max_len) ? max_len : this_len;
998
999 retval = access_process_vm(task, (mm->env_start + src),
1000 page, this_len, 0);
1001
1002 if (retval <= 0) {
1003 ret = retval;
1004 break;
1005 }
1006
1007 if (copy_to_user(buf, page, retval)) {
1008 ret = -EFAULT;
1009 break;
1010 }
1011
1012 ret += retval;
1013 src += retval;
1014 buf += retval;
1015 count -= retval;
1016 }
1017 *ppos = src;
1018
1019 mmput(mm);
1020 out_free:
1021 free_page((unsigned long) page);
1022 out:
1023 put_task_struct(task);
1024 out_no_task:
1025 return ret;
1026 }
1027
1028 static const struct file_operations proc_environ_operations = {
1029 .read = environ_read,
1030 .llseek = generic_file_llseek,
1031 };
1032
1033 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
1034 size_t count, loff_t *ppos)
1035 {
1036 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1037 char buffer[PROC_NUMBUF];
1038 size_t len;
1039 int oom_adjust = OOM_DISABLE;
1040 unsigned long flags;
1041
1042 if (!task)
1043 return -ESRCH;
1044
1045 if (lock_task_sighand(task, &flags)) {
1046 oom_adjust = task->signal->oom_adj;
1047 unlock_task_sighand(task, &flags);
1048 }
1049
1050 put_task_struct(task);
1051
1052 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
1053
1054 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1055 }
1056
1057 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
1058 size_t count, loff_t *ppos)
1059 {
1060 struct task_struct *task;
1061 char buffer[PROC_NUMBUF];
1062 long oom_adjust;
1063 unsigned long flags;
1064 int err;
1065
1066 memset(buffer, 0, sizeof(buffer));
1067 if (count > sizeof(buffer) - 1)
1068 count = sizeof(buffer) - 1;
1069 if (copy_from_user(buffer, buf, count)) {
1070 err = -EFAULT;
1071 goto out;
1072 }
1073
1074 err = strict_strtol(strstrip(buffer), 0, &oom_adjust);
1075 if (err)
1076 goto out;
1077 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
1078 oom_adjust != OOM_DISABLE) {
1079 err = -EINVAL;
1080 goto out;
1081 }
1082
1083 task = get_proc_task(file->f_path.dentry->d_inode);
1084 if (!task) {
1085 err = -ESRCH;
1086 goto out;
1087 }
1088
1089 task_lock(task);
1090 if (!task->mm) {
1091 err = -EINVAL;
1092 goto err_task_lock;
1093 }
1094
1095 if (!lock_task_sighand(task, &flags)) {
1096 err = -ESRCH;
1097 goto err_task_lock;
1098 }
1099
1100 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
1101 err = -EACCES;
1102 goto err_sighand;
1103 }
1104
1105 if (oom_adjust != task->signal->oom_adj) {
1106 if (oom_adjust == OOM_DISABLE)
1107 atomic_inc(&task->mm->oom_disable_count);
1108 if (task->signal->oom_adj == OOM_DISABLE)
1109 atomic_dec(&task->mm->oom_disable_count);
1110 }
1111
1112 /*
1113 * Warn that /proc/pid/oom_adj is deprecated, see
1114 * Documentation/feature-removal-schedule.txt.
1115 */
1116 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, "
1117 "please use /proc/%d/oom_score_adj instead.\n",
1118 current->comm, task_pid_nr(current),
1119 task_pid_nr(task), task_pid_nr(task));
1120 task->signal->oom_adj = oom_adjust;
1121 /*
1122 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1123 * value is always attainable.
1124 */
1125 if (task->signal->oom_adj == OOM_ADJUST_MAX)
1126 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
1127 else
1128 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
1129 -OOM_DISABLE;
1130 err_sighand:
1131 unlock_task_sighand(task, &flags);
1132 err_task_lock:
1133 task_unlock(task);
1134 put_task_struct(task);
1135 out:
1136 return err < 0 ? err : count;
1137 }
1138
1139 static const struct file_operations proc_oom_adjust_operations = {
1140 .read = oom_adjust_read,
1141 .write = oom_adjust_write,
1142 .llseek = generic_file_llseek,
1143 };
1144
1145 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1146 size_t count, loff_t *ppos)
1147 {
1148 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1149 char buffer[PROC_NUMBUF];
1150 int oom_score_adj = OOM_SCORE_ADJ_MIN;
1151 unsigned long flags;
1152 size_t len;
1153
1154 if (!task)
1155 return -ESRCH;
1156 if (lock_task_sighand(task, &flags)) {
1157 oom_score_adj = task->signal->oom_score_adj;
1158 unlock_task_sighand(task, &flags);
1159 }
1160 put_task_struct(task);
1161 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
1162 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1163 }
1164
1165 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1166 size_t count, loff_t *ppos)
1167 {
1168 struct task_struct *task;
1169 char buffer[PROC_NUMBUF];
1170 unsigned long flags;
1171 long oom_score_adj;
1172 int err;
1173
1174 memset(buffer, 0, sizeof(buffer));
1175 if (count > sizeof(buffer) - 1)
1176 count = sizeof(buffer) - 1;
1177 if (copy_from_user(buffer, buf, count)) {
1178 err = -EFAULT;
1179 goto out;
1180 }
1181
1182 err = strict_strtol(strstrip(buffer), 0, &oom_score_adj);
1183 if (err)
1184 goto out;
1185 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1186 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1187 err = -EINVAL;
1188 goto out;
1189 }
1190
1191 task = get_proc_task(file->f_path.dentry->d_inode);
1192 if (!task) {
1193 err = -ESRCH;
1194 goto out;
1195 }
1196
1197 task_lock(task);
1198 if (!task->mm) {
1199 err = -EINVAL;
1200 goto err_task_lock;
1201 }
1202
1203 if (!lock_task_sighand(task, &flags)) {
1204 err = -ESRCH;
1205 goto err_task_lock;
1206 }
1207
1208 if (oom_score_adj < task->signal->oom_score_adj_min &&
1209 !capable(CAP_SYS_RESOURCE)) {
1210 err = -EACCES;
1211 goto err_sighand;
1212 }
1213
1214 if (oom_score_adj != task->signal->oom_score_adj) {
1215 if (oom_score_adj == OOM_SCORE_ADJ_MIN)
1216 atomic_inc(&task->mm->oom_disable_count);
1217 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1218 atomic_dec(&task->mm->oom_disable_count);
1219 }
1220 task->signal->oom_score_adj = oom_score_adj;
1221 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1222 task->signal->oom_score_adj_min = oom_score_adj;
1223 /*
1224 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1225 * always attainable.
1226 */
1227 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1228 task->signal->oom_adj = OOM_DISABLE;
1229 else
1230 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1231 OOM_SCORE_ADJ_MAX;
1232 err_sighand:
1233 unlock_task_sighand(task, &flags);
1234 err_task_lock:
1235 task_unlock(task);
1236 put_task_struct(task);
1237 out:
1238 return err < 0 ? err : count;
1239 }
1240
1241 static const struct file_operations proc_oom_score_adj_operations = {
1242 .read = oom_score_adj_read,
1243 .write = oom_score_adj_write,
1244 .llseek = default_llseek,
1245 };
1246
1247 #ifdef CONFIG_AUDITSYSCALL
1248 #define TMPBUFLEN 21
1249 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1250 size_t count, loff_t *ppos)
1251 {
1252 struct inode * inode = file->f_path.dentry->d_inode;
1253 struct task_struct *task = get_proc_task(inode);
1254 ssize_t length;
1255 char tmpbuf[TMPBUFLEN];
1256
1257 if (!task)
1258 return -ESRCH;
1259 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1260 audit_get_loginuid(task));
1261 put_task_struct(task);
1262 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1263 }
1264
1265 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1266 size_t count, loff_t *ppos)
1267 {
1268 struct inode * inode = file->f_path.dentry->d_inode;
1269 char *page, *tmp;
1270 ssize_t length;
1271 uid_t loginuid;
1272
1273 if (!capable(CAP_AUDIT_CONTROL))
1274 return -EPERM;
1275
1276 rcu_read_lock();
1277 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1278 rcu_read_unlock();
1279 return -EPERM;
1280 }
1281 rcu_read_unlock();
1282
1283 if (count >= PAGE_SIZE)
1284 count = PAGE_SIZE - 1;
1285
1286 if (*ppos != 0) {
1287 /* No partial writes. */
1288 return -EINVAL;
1289 }
1290 page = (char*)__get_free_page(GFP_TEMPORARY);
1291 if (!page)
1292 return -ENOMEM;
1293 length = -EFAULT;
1294 if (copy_from_user(page, buf, count))
1295 goto out_free_page;
1296
1297 page[count] = '\0';
1298 loginuid = simple_strtoul(page, &tmp, 10);
1299 if (tmp == page) {
1300 length = -EINVAL;
1301 goto out_free_page;
1302
1303 }
1304 length = audit_set_loginuid(current, loginuid);
1305 if (likely(length == 0))
1306 length = count;
1307
1308 out_free_page:
1309 free_page((unsigned long) page);
1310 return length;
1311 }
1312
1313 static const struct file_operations proc_loginuid_operations = {
1314 .read = proc_loginuid_read,
1315 .write = proc_loginuid_write,
1316 .llseek = generic_file_llseek,
1317 };
1318
1319 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1320 size_t count, loff_t *ppos)
1321 {
1322 struct inode * inode = file->f_path.dentry->d_inode;
1323 struct task_struct *task = get_proc_task(inode);
1324 ssize_t length;
1325 char tmpbuf[TMPBUFLEN];
1326
1327 if (!task)
1328 return -ESRCH;
1329 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1330 audit_get_sessionid(task));
1331 put_task_struct(task);
1332 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1333 }
1334
1335 static const struct file_operations proc_sessionid_operations = {
1336 .read = proc_sessionid_read,
1337 .llseek = generic_file_llseek,
1338 };
1339 #endif
1340
1341 #ifdef CONFIG_FAULT_INJECTION
1342 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1343 size_t count, loff_t *ppos)
1344 {
1345 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1346 char buffer[PROC_NUMBUF];
1347 size_t len;
1348 int make_it_fail;
1349
1350 if (!task)
1351 return -ESRCH;
1352 make_it_fail = task->make_it_fail;
1353 put_task_struct(task);
1354
1355 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1356
1357 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1358 }
1359
1360 static ssize_t proc_fault_inject_write(struct file * file,
1361 const char __user * buf, size_t count, loff_t *ppos)
1362 {
1363 struct task_struct *task;
1364 char buffer[PROC_NUMBUF], *end;
1365 int make_it_fail;
1366
1367 if (!capable(CAP_SYS_RESOURCE))
1368 return -EPERM;
1369 memset(buffer, 0, sizeof(buffer));
1370 if (count > sizeof(buffer) - 1)
1371 count = sizeof(buffer) - 1;
1372 if (copy_from_user(buffer, buf, count))
1373 return -EFAULT;
1374 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1375 if (*end)
1376 return -EINVAL;
1377 task = get_proc_task(file->f_dentry->d_inode);
1378 if (!task)
1379 return -ESRCH;
1380 task->make_it_fail = make_it_fail;
1381 put_task_struct(task);
1382
1383 return count;
1384 }
1385
1386 static const struct file_operations proc_fault_inject_operations = {
1387 .read = proc_fault_inject_read,
1388 .write = proc_fault_inject_write,
1389 .llseek = generic_file_llseek,
1390 };
1391 #endif
1392
1393
1394 #ifdef CONFIG_SCHED_DEBUG
1395 /*
1396 * Print out various scheduling related per-task fields:
1397 */
1398 static int sched_show(struct seq_file *m, void *v)
1399 {
1400 struct inode *inode = m->private;
1401 struct task_struct *p;
1402
1403 p = get_proc_task(inode);
1404 if (!p)
1405 return -ESRCH;
1406 proc_sched_show_task(p, m);
1407
1408 put_task_struct(p);
1409
1410 return 0;
1411 }
1412
1413 static ssize_t
1414 sched_write(struct file *file, const char __user *buf,
1415 size_t count, loff_t *offset)
1416 {
1417 struct inode *inode = file->f_path.dentry->d_inode;
1418 struct task_struct *p;
1419
1420 p = get_proc_task(inode);
1421 if (!p)
1422 return -ESRCH;
1423 proc_sched_set_task(p);
1424
1425 put_task_struct(p);
1426
1427 return count;
1428 }
1429
1430 static int sched_open(struct inode *inode, struct file *filp)
1431 {
1432 return single_open(filp, sched_show, inode);
1433 }
1434
1435 static const struct file_operations proc_pid_sched_operations = {
1436 .open = sched_open,
1437 .read = seq_read,
1438 .write = sched_write,
1439 .llseek = seq_lseek,
1440 .release = single_release,
1441 };
1442
1443 #endif
1444
1445 #ifdef CONFIG_SCHED_AUTOGROUP
1446 /*
1447 * Print out autogroup related information:
1448 */
1449 static int sched_autogroup_show(struct seq_file *m, void *v)
1450 {
1451 struct inode *inode = m->private;
1452 struct task_struct *p;
1453
1454 p = get_proc_task(inode);
1455 if (!p)
1456 return -ESRCH;
1457 proc_sched_autogroup_show_task(p, m);
1458
1459 put_task_struct(p);
1460
1461 return 0;
1462 }
1463
1464 static ssize_t
1465 sched_autogroup_write(struct file *file, const char __user *buf,
1466 size_t count, loff_t *offset)
1467 {
1468 struct inode *inode = file->f_path.dentry->d_inode;
1469 struct task_struct *p;
1470 char buffer[PROC_NUMBUF];
1471 long nice;
1472 int err;
1473
1474 memset(buffer, 0, sizeof(buffer));
1475 if (count > sizeof(buffer) - 1)
1476 count = sizeof(buffer) - 1;
1477 if (copy_from_user(buffer, buf, count))
1478 return -EFAULT;
1479
1480 err = strict_strtol(strstrip(buffer), 0, &nice);
1481 if (err)
1482 return -EINVAL;
1483
1484 p = get_proc_task(inode);
1485 if (!p)
1486 return -ESRCH;
1487
1488 err = nice;
1489 err = proc_sched_autogroup_set_nice(p, &err);
1490 if (err)
1491 count = err;
1492
1493 put_task_struct(p);
1494
1495 return count;
1496 }
1497
1498 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1499 {
1500 int ret;
1501
1502 ret = single_open(filp, sched_autogroup_show, NULL);
1503 if (!ret) {
1504 struct seq_file *m = filp->private_data;
1505
1506 m->private = inode;
1507 }
1508 return ret;
1509 }
1510
1511 static const struct file_operations proc_pid_sched_autogroup_operations = {
1512 .open = sched_autogroup_open,
1513 .read = seq_read,
1514 .write = sched_autogroup_write,
1515 .llseek = seq_lseek,
1516 .release = single_release,
1517 };
1518
1519 #endif /* CONFIG_SCHED_AUTOGROUP */
1520
1521 static ssize_t comm_write(struct file *file, const char __user *buf,
1522 size_t count, loff_t *offset)
1523 {
1524 struct inode *inode = file->f_path.dentry->d_inode;
1525 struct task_struct *p;
1526 char buffer[TASK_COMM_LEN];
1527
1528 memset(buffer, 0, sizeof(buffer));
1529 if (count > sizeof(buffer) - 1)
1530 count = sizeof(buffer) - 1;
1531 if (copy_from_user(buffer, buf, count))
1532 return -EFAULT;
1533
1534 p = get_proc_task(inode);
1535 if (!p)
1536 return -ESRCH;
1537
1538 if (same_thread_group(current, p))
1539 set_task_comm(p, buffer);
1540 else
1541 count = -EINVAL;
1542
1543 put_task_struct(p);
1544
1545 return count;
1546 }
1547
1548 static int comm_show(struct seq_file *m, void *v)
1549 {
1550 struct inode *inode = m->private;
1551 struct task_struct *p;
1552
1553 p = get_proc_task(inode);
1554 if (!p)
1555 return -ESRCH;
1556
1557 task_lock(p);
1558 seq_printf(m, "%s\n", p->comm);
1559 task_unlock(p);
1560
1561 put_task_struct(p);
1562
1563 return 0;
1564 }
1565
1566 static int comm_open(struct inode *inode, struct file *filp)
1567 {
1568 return single_open(filp, comm_show, inode);
1569 }
1570
1571 static const struct file_operations proc_pid_set_comm_operations = {
1572 .open = comm_open,
1573 .read = seq_read,
1574 .write = comm_write,
1575 .llseek = seq_lseek,
1576 .release = single_release,
1577 };
1578
1579 /*
1580 * We added or removed a vma mapping the executable. The vmas are only mapped
1581 * during exec and are not mapped with the mmap system call.
1582 * Callers must hold down_write() on the mm's mmap_sem for these
1583 */
1584 void added_exe_file_vma(struct mm_struct *mm)
1585 {
1586 mm->num_exe_file_vmas++;
1587 }
1588
1589 void removed_exe_file_vma(struct mm_struct *mm)
1590 {
1591 mm->num_exe_file_vmas--;
1592 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){
1593 fput(mm->exe_file);
1594 mm->exe_file = NULL;
1595 }
1596
1597 }
1598
1599 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file)
1600 {
1601 if (new_exe_file)
1602 get_file(new_exe_file);
1603 if (mm->exe_file)
1604 fput(mm->exe_file);
1605 mm->exe_file = new_exe_file;
1606 mm->num_exe_file_vmas = 0;
1607 }
1608
1609 struct file *get_mm_exe_file(struct mm_struct *mm)
1610 {
1611 struct file *exe_file;
1612
1613 /* We need mmap_sem to protect against races with removal of
1614 * VM_EXECUTABLE vmas */
1615 down_read(&mm->mmap_sem);
1616 exe_file = mm->exe_file;
1617 if (exe_file)
1618 get_file(exe_file);
1619 up_read(&mm->mmap_sem);
1620 return exe_file;
1621 }
1622
1623 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm)
1624 {
1625 /* It's safe to write the exe_file pointer without exe_file_lock because
1626 * this is called during fork when the task is not yet in /proc */
1627 newmm->exe_file = get_mm_exe_file(oldmm);
1628 }
1629
1630 static int proc_exe_link(struct inode *inode, struct path *exe_path)
1631 {
1632 struct task_struct *task;
1633 struct mm_struct *mm;
1634 struct file *exe_file;
1635
1636 task = get_proc_task(inode);
1637 if (!task)
1638 return -ENOENT;
1639 mm = get_task_mm(task);
1640 put_task_struct(task);
1641 if (!mm)
1642 return -ENOENT;
1643 exe_file = get_mm_exe_file(mm);
1644 mmput(mm);
1645 if (exe_file) {
1646 *exe_path = exe_file->f_path;
1647 path_get(&exe_file->f_path);
1648 fput(exe_file);
1649 return 0;
1650 } else
1651 return -ENOENT;
1652 }
1653
1654 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1655 {
1656 struct inode *inode = dentry->d_inode;
1657 int error = -EACCES;
1658
1659 /* We don't need a base pointer in the /proc filesystem */
1660 path_put(&nd->path);
1661
1662 /* Are we allowed to snoop on the tasks file descriptors? */
1663 if (!proc_fd_access_allowed(inode))
1664 goto out;
1665
1666 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
1667 out:
1668 return ERR_PTR(error);
1669 }
1670
1671 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1672 {
1673 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1674 char *pathname;
1675 int len;
1676
1677 if (!tmp)
1678 return -ENOMEM;
1679
1680 pathname = d_path(path, tmp, PAGE_SIZE);
1681 len = PTR_ERR(pathname);
1682 if (IS_ERR(pathname))
1683 goto out;
1684 len = tmp + PAGE_SIZE - 1 - pathname;
1685
1686 if (len > buflen)
1687 len = buflen;
1688 if (copy_to_user(buffer, pathname, len))
1689 len = -EFAULT;
1690 out:
1691 free_page((unsigned long)tmp);
1692 return len;
1693 }
1694
1695 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1696 {
1697 int error = -EACCES;
1698 struct inode *inode = dentry->d_inode;
1699 struct path path;
1700
1701 /* Are we allowed to snoop on the tasks file descriptors? */
1702 if (!proc_fd_access_allowed(inode))
1703 goto out;
1704
1705 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1706 if (error)
1707 goto out;
1708
1709 error = do_proc_readlink(&path, buffer, buflen);
1710 path_put(&path);
1711 out:
1712 return error;
1713 }
1714
1715 static const struct inode_operations proc_pid_link_inode_operations = {
1716 .readlink = proc_pid_readlink,
1717 .follow_link = proc_pid_follow_link,
1718 .setattr = proc_setattr,
1719 };
1720
1721
1722 /* building an inode */
1723
1724 static int task_dumpable(struct task_struct *task)
1725 {
1726 int dumpable = 0;
1727 struct mm_struct *mm;
1728
1729 task_lock(task);
1730 mm = task->mm;
1731 if (mm)
1732 dumpable = get_dumpable(mm);
1733 task_unlock(task);
1734 if(dumpable == 1)
1735 return 1;
1736 return 0;
1737 }
1738
1739
1740 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1741 {
1742 struct inode * inode;
1743 struct proc_inode *ei;
1744 const struct cred *cred;
1745
1746 /* We need a new inode */
1747
1748 inode = new_inode(sb);
1749 if (!inode)
1750 goto out;
1751
1752 /* Common stuff */
1753 ei = PROC_I(inode);
1754 inode->i_ino = get_next_ino();
1755 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1756 inode->i_op = &proc_def_inode_operations;
1757
1758 /*
1759 * grab the reference to task.
1760 */
1761 ei->pid = get_task_pid(task, PIDTYPE_PID);
1762 if (!ei->pid)
1763 goto out_unlock;
1764
1765 if (task_dumpable(task)) {
1766 rcu_read_lock();
1767 cred = __task_cred(task);
1768 inode->i_uid = cred->euid;
1769 inode->i_gid = cred->egid;
1770 rcu_read_unlock();
1771 }
1772 security_task_to_inode(task, inode);
1773
1774 out:
1775 return inode;
1776
1777 out_unlock:
1778 iput(inode);
1779 return NULL;
1780 }
1781
1782 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1783 {
1784 struct inode *inode = dentry->d_inode;
1785 struct task_struct *task;
1786 const struct cred *cred;
1787
1788 generic_fillattr(inode, stat);
1789
1790 rcu_read_lock();
1791 stat->uid = 0;
1792 stat->gid = 0;
1793 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1794 if (task) {
1795 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1796 task_dumpable(task)) {
1797 cred = __task_cred(task);
1798 stat->uid = cred->euid;
1799 stat->gid = cred->egid;
1800 }
1801 }
1802 rcu_read_unlock();
1803 return 0;
1804 }
1805
1806 /* dentry stuff */
1807
1808 /*
1809 * Exceptional case: normally we are not allowed to unhash a busy
1810 * directory. In this case, however, we can do it - no aliasing problems
1811 * due to the way we treat inodes.
1812 *
1813 * Rewrite the inode's ownerships here because the owning task may have
1814 * performed a setuid(), etc.
1815 *
1816 * Before the /proc/pid/status file was created the only way to read
1817 * the effective uid of a /process was to stat /proc/pid. Reading
1818 * /proc/pid/status is slow enough that procps and other packages
1819 * kept stating /proc/pid. To keep the rules in /proc simple I have
1820 * made this apply to all per process world readable and executable
1821 * directories.
1822 */
1823 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1824 {
1825 struct inode *inode;
1826 struct task_struct *task;
1827 const struct cred *cred;
1828
1829 if (nd && nd->flags & LOOKUP_RCU)
1830 return -ECHILD;
1831
1832 inode = dentry->d_inode;
1833 task = get_proc_task(inode);
1834
1835 if (task) {
1836 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1837 task_dumpable(task)) {
1838 rcu_read_lock();
1839 cred = __task_cred(task);
1840 inode->i_uid = cred->euid;
1841 inode->i_gid = cred->egid;
1842 rcu_read_unlock();
1843 } else {
1844 inode->i_uid = 0;
1845 inode->i_gid = 0;
1846 }
1847 inode->i_mode &= ~(S_ISUID | S_ISGID);
1848 security_task_to_inode(task, inode);
1849 put_task_struct(task);
1850 return 1;
1851 }
1852 d_drop(dentry);
1853 return 0;
1854 }
1855
1856 static int pid_delete_dentry(const struct dentry * dentry)
1857 {
1858 /* Is the task we represent dead?
1859 * If so, then don't put the dentry on the lru list,
1860 * kill it immediately.
1861 */
1862 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1863 }
1864
1865 static const struct dentry_operations pid_dentry_operations =
1866 {
1867 .d_revalidate = pid_revalidate,
1868 .d_delete = pid_delete_dentry,
1869 };
1870
1871 /* Lookups */
1872
1873 typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
1874 struct task_struct *, const void *);
1875
1876 /*
1877 * Fill a directory entry.
1878 *
1879 * If possible create the dcache entry and derive our inode number and
1880 * file type from dcache entry.
1881 *
1882 * Since all of the proc inode numbers are dynamically generated, the inode
1883 * numbers do not exist until the inode is cache. This means creating the
1884 * the dcache entry in readdir is necessary to keep the inode numbers
1885 * reported by readdir in sync with the inode numbers reported
1886 * by stat.
1887 */
1888 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1889 char *name, int len,
1890 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1891 {
1892 struct dentry *child, *dir = filp->f_path.dentry;
1893 struct inode *inode;
1894 struct qstr qname;
1895 ino_t ino = 0;
1896 unsigned type = DT_UNKNOWN;
1897
1898 qname.name = name;
1899 qname.len = len;
1900 qname.hash = full_name_hash(name, len);
1901
1902 child = d_lookup(dir, &qname);
1903 if (!child) {
1904 struct dentry *new;
1905 new = d_alloc(dir, &qname);
1906 if (new) {
1907 child = instantiate(dir->d_inode, new, task, ptr);
1908 if (child)
1909 dput(new);
1910 else
1911 child = new;
1912 }
1913 }
1914 if (!child || IS_ERR(child) || !child->d_inode)
1915 goto end_instantiate;
1916 inode = child->d_inode;
1917 if (inode) {
1918 ino = inode->i_ino;
1919 type = inode->i_mode >> 12;
1920 }
1921 dput(child);
1922 end_instantiate:
1923 if (!ino)
1924 ino = find_inode_number(dir, &qname);
1925 if (!ino)
1926 ino = 1;
1927 return filldir(dirent, name, len, filp->f_pos, ino, type);
1928 }
1929
1930 static unsigned name_to_int(struct dentry *dentry)
1931 {
1932 const char *name = dentry->d_name.name;
1933 int len = dentry->d_name.len;
1934 unsigned n = 0;
1935
1936 if (len > 1 && *name == '0')
1937 goto out;
1938 while (len-- > 0) {
1939 unsigned c = *name++ - '0';
1940 if (c > 9)
1941 goto out;
1942 if (n >= (~0U-9)/10)
1943 goto out;
1944 n *= 10;
1945 n += c;
1946 }
1947 return n;
1948 out:
1949 return ~0U;
1950 }
1951
1952 #define PROC_FDINFO_MAX 64
1953
1954 static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1955 {
1956 struct task_struct *task = get_proc_task(inode);
1957 struct files_struct *files = NULL;
1958 struct file *file;
1959 int fd = proc_fd(inode);
1960
1961 if (task) {
1962 files = get_files_struct(task);
1963 put_task_struct(task);
1964 }
1965 if (files) {
1966 /*
1967 * We are not taking a ref to the file structure, so we must
1968 * hold ->file_lock.
1969 */
1970 spin_lock(&files->file_lock);
1971 file = fcheck_files(files, fd);
1972 if (file) {
1973 if (path) {
1974 *path = file->f_path;
1975 path_get(&file->f_path);
1976 }
1977 if (info)
1978 snprintf(info, PROC_FDINFO_MAX,
1979 "pos:\t%lli\n"
1980 "flags:\t0%o\n",
1981 (long long) file->f_pos,
1982 file->f_flags);
1983 spin_unlock(&files->file_lock);
1984 put_files_struct(files);
1985 return 0;
1986 }
1987 spin_unlock(&files->file_lock);
1988 put_files_struct(files);
1989 }
1990 return -ENOENT;
1991 }
1992
1993 static int proc_fd_link(struct inode *inode, struct path *path)
1994 {
1995 return proc_fd_info(inode, path, NULL);
1996 }
1997
1998 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1999 {
2000 struct inode *inode;
2001 struct task_struct *task;
2002 int fd;
2003 struct files_struct *files;
2004 const struct cred *cred;
2005
2006 if (nd && nd->flags & LOOKUP_RCU)
2007 return -ECHILD;
2008
2009 inode = dentry->d_inode;
2010 task = get_proc_task(inode);
2011 fd = proc_fd(inode);
2012
2013 if (task) {
2014 files = get_files_struct(task);
2015 if (files) {
2016 rcu_read_lock();
2017 if (fcheck_files(files, fd)) {
2018 rcu_read_unlock();
2019 put_files_struct(files);
2020 if (task_dumpable(task)) {
2021 rcu_read_lock();
2022 cred = __task_cred(task);
2023 inode->i_uid = cred->euid;
2024 inode->i_gid = cred->egid;
2025 rcu_read_unlock();
2026 } else {
2027 inode->i_uid = 0;
2028 inode->i_gid = 0;
2029 }
2030 inode->i_mode &= ~(S_ISUID | S_ISGID);
2031 security_task_to_inode(task, inode);
2032 put_task_struct(task);
2033 return 1;
2034 }
2035 rcu_read_unlock();
2036 put_files_struct(files);
2037 }
2038 put_task_struct(task);
2039 }
2040 d_drop(dentry);
2041 return 0;
2042 }
2043
2044 static const struct dentry_operations tid_fd_dentry_operations =
2045 {
2046 .d_revalidate = tid_fd_revalidate,
2047 .d_delete = pid_delete_dentry,
2048 };
2049
2050 static struct dentry *proc_fd_instantiate(struct inode *dir,
2051 struct dentry *dentry, struct task_struct *task, const void *ptr)
2052 {
2053 unsigned fd = *(const unsigned *)ptr;
2054 struct file *file;
2055 struct files_struct *files;
2056 struct inode *inode;
2057 struct proc_inode *ei;
2058 struct dentry *error = ERR_PTR(-ENOENT);
2059
2060 inode = proc_pid_make_inode(dir->i_sb, task);
2061 if (!inode)
2062 goto out;
2063 ei = PROC_I(inode);
2064 ei->fd = fd;
2065 files = get_files_struct(task);
2066 if (!files)
2067 goto out_iput;
2068 inode->i_mode = S_IFLNK;
2069
2070 /*
2071 * We are not taking a ref to the file structure, so we must
2072 * hold ->file_lock.
2073 */
2074 spin_lock(&files->file_lock);
2075 file = fcheck_files(files, fd);
2076 if (!file)
2077 goto out_unlock;
2078 if (file->f_mode & FMODE_READ)
2079 inode->i_mode |= S_IRUSR | S_IXUSR;
2080 if (file->f_mode & FMODE_WRITE)
2081 inode->i_mode |= S_IWUSR | S_IXUSR;
2082 spin_unlock(&files->file_lock);
2083 put_files_struct(files);
2084
2085 inode->i_op = &proc_pid_link_inode_operations;
2086 inode->i_size = 64;
2087 ei->op.proc_get_link = proc_fd_link;
2088 d_set_d_op(dentry, &tid_fd_dentry_operations);
2089 d_add(dentry, inode);
2090 /* Close the race of the process dying before we return the dentry */
2091 if (tid_fd_revalidate(dentry, NULL))
2092 error = NULL;
2093
2094 out:
2095 return error;
2096 out_unlock:
2097 spin_unlock(&files->file_lock);
2098 put_files_struct(files);
2099 out_iput:
2100 iput(inode);
2101 goto out;
2102 }
2103
2104 static struct dentry *proc_lookupfd_common(struct inode *dir,
2105 struct dentry *dentry,
2106 instantiate_t instantiate)
2107 {
2108 struct task_struct *task = get_proc_task(dir);
2109 unsigned fd = name_to_int(dentry);
2110 struct dentry *result = ERR_PTR(-ENOENT);
2111
2112 if (!task)
2113 goto out_no_task;
2114 if (fd == ~0U)
2115 goto out;
2116
2117 result = instantiate(dir, dentry, task, &fd);
2118 out:
2119 put_task_struct(task);
2120 out_no_task:
2121 return result;
2122 }
2123
2124 static int proc_readfd_common(struct file * filp, void * dirent,
2125 filldir_t filldir, instantiate_t instantiate)
2126 {
2127 struct dentry *dentry = filp->f_path.dentry;
2128 struct inode *inode = dentry->d_inode;
2129 struct task_struct *p = get_proc_task(inode);
2130 unsigned int fd, ino;
2131 int retval;
2132 struct files_struct * files;
2133
2134 retval = -ENOENT;
2135 if (!p)
2136 goto out_no_task;
2137 retval = 0;
2138
2139 fd = filp->f_pos;
2140 switch (fd) {
2141 case 0:
2142 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
2143 goto out;
2144 filp->f_pos++;
2145 case 1:
2146 ino = parent_ino(dentry);
2147 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
2148 goto out;
2149 filp->f_pos++;
2150 default:
2151 files = get_files_struct(p);
2152 if (!files)
2153 goto out;
2154 rcu_read_lock();
2155 for (fd = filp->f_pos-2;
2156 fd < files_fdtable(files)->max_fds;
2157 fd++, filp->f_pos++) {
2158 char name[PROC_NUMBUF];
2159 int len;
2160
2161 if (!fcheck_files(files, fd))
2162 continue;
2163 rcu_read_unlock();
2164
2165 len = snprintf(name, sizeof(name), "%d", fd);
2166 if (proc_fill_cache(filp, dirent, filldir,
2167 name, len, instantiate,
2168 p, &fd) < 0) {
2169 rcu_read_lock();
2170 break;
2171 }
2172 rcu_read_lock();
2173 }
2174 rcu_read_unlock();
2175 put_files_struct(files);
2176 }
2177 out:
2178 put_task_struct(p);
2179 out_no_task:
2180 return retval;
2181 }
2182
2183 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
2184 struct nameidata *nd)
2185 {
2186 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
2187 }
2188
2189 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
2190 {
2191 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
2192 }
2193
2194 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
2195 size_t len, loff_t *ppos)
2196 {
2197 char tmp[PROC_FDINFO_MAX];
2198 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
2199 if (!err)
2200 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
2201 return err;
2202 }
2203
2204 static const struct file_operations proc_fdinfo_file_operations = {
2205 .open = nonseekable_open,
2206 .read = proc_fdinfo_read,
2207 .llseek = no_llseek,
2208 };
2209
2210 static const struct file_operations proc_fd_operations = {
2211 .read = generic_read_dir,
2212 .readdir = proc_readfd,
2213 .llseek = default_llseek,
2214 };
2215
2216 /*
2217 * /proc/pid/fd needs a special permission handler so that a process can still
2218 * access /proc/self/fd after it has executed a setuid().
2219 */
2220 static int proc_fd_permission(struct inode *inode, int mask, unsigned int flags)
2221 {
2222 int rv;
2223
2224 if (flags & IPERM_FLAG_RCU)
2225 return -ECHILD;
2226 rv = generic_permission(inode, mask, flags, NULL);
2227 if (rv == 0)
2228 return 0;
2229 if (task_pid(current) == proc_pid(inode))
2230 rv = 0;
2231 return rv;
2232 }
2233
2234 /*
2235 * proc directories can do almost nothing..
2236 */
2237 static const struct inode_operations proc_fd_inode_operations = {
2238 .lookup = proc_lookupfd,
2239 .permission = proc_fd_permission,
2240 .setattr = proc_setattr,
2241 };
2242
2243 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2244 struct dentry *dentry, struct task_struct *task, const void *ptr)
2245 {
2246 unsigned fd = *(unsigned *)ptr;
2247 struct inode *inode;
2248 struct proc_inode *ei;
2249 struct dentry *error = ERR_PTR(-ENOENT);
2250
2251 inode = proc_pid_make_inode(dir->i_sb, task);
2252 if (!inode)
2253 goto out;
2254 ei = PROC_I(inode);
2255 ei->fd = fd;
2256 inode->i_mode = S_IFREG | S_IRUSR;
2257 inode->i_fop = &proc_fdinfo_file_operations;
2258 d_set_d_op(dentry, &tid_fd_dentry_operations);
2259 d_add(dentry, inode);
2260 /* Close the race of the process dying before we return the dentry */
2261 if (tid_fd_revalidate(dentry, NULL))
2262 error = NULL;
2263
2264 out:
2265 return error;
2266 }
2267
2268 static struct dentry *proc_lookupfdinfo(struct inode *dir,
2269 struct dentry *dentry,
2270 struct nameidata *nd)
2271 {
2272 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2273 }
2274
2275 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2276 {
2277 return proc_readfd_common(filp, dirent, filldir,
2278 proc_fdinfo_instantiate);
2279 }
2280
2281 static const struct file_operations proc_fdinfo_operations = {
2282 .read = generic_read_dir,
2283 .readdir = proc_readfdinfo,
2284 .llseek = default_llseek,
2285 };
2286
2287 /*
2288 * proc directories can do almost nothing..
2289 */
2290 static const struct inode_operations proc_fdinfo_inode_operations = {
2291 .lookup = proc_lookupfdinfo,
2292 .setattr = proc_setattr,
2293 };
2294
2295
2296 static struct dentry *proc_pident_instantiate(struct inode *dir,
2297 struct dentry *dentry, struct task_struct *task, const void *ptr)
2298 {
2299 const struct pid_entry *p = ptr;
2300 struct inode *inode;
2301 struct proc_inode *ei;
2302 struct dentry *error = ERR_PTR(-ENOENT);
2303
2304 inode = proc_pid_make_inode(dir->i_sb, task);
2305 if (!inode)
2306 goto out;
2307
2308 ei = PROC_I(inode);
2309 inode->i_mode = p->mode;
2310 if (S_ISDIR(inode->i_mode))
2311 inode->i_nlink = 2; /* Use getattr to fix if necessary */
2312 if (p->iop)
2313 inode->i_op = p->iop;
2314 if (p->fop)
2315 inode->i_fop = p->fop;
2316 ei->op = p->op;
2317 d_set_d_op(dentry, &pid_dentry_operations);
2318 d_add(dentry, inode);
2319 /* Close the race of the process dying before we return the dentry */
2320 if (pid_revalidate(dentry, NULL))
2321 error = NULL;
2322 out:
2323 return error;
2324 }
2325
2326 static struct dentry *proc_pident_lookup(struct inode *dir,
2327 struct dentry *dentry,
2328 const struct pid_entry *ents,
2329 unsigned int nents)
2330 {
2331 struct dentry *error;
2332 struct task_struct *task = get_proc_task(dir);
2333 const struct pid_entry *p, *last;
2334
2335 error = ERR_PTR(-ENOENT);
2336
2337 if (!task)
2338 goto out_no_task;
2339
2340 /*
2341 * Yes, it does not scale. And it should not. Don't add
2342 * new entries into /proc/<tgid>/ without very good reasons.
2343 */
2344 last = &ents[nents - 1];
2345 for (p = ents; p <= last; p++) {
2346 if (p->len != dentry->d_name.len)
2347 continue;
2348 if (!memcmp(dentry->d_name.name, p->name, p->len))
2349 break;
2350 }
2351 if (p > last)
2352 goto out;
2353
2354 error = proc_pident_instantiate(dir, dentry, task, p);
2355 out:
2356 put_task_struct(task);
2357 out_no_task:
2358 return error;
2359 }
2360
2361 static int proc_pident_fill_cache(struct file *filp, void *dirent,
2362 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2363 {
2364 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2365 proc_pident_instantiate, task, p);
2366 }
2367
2368 static int proc_pident_readdir(struct file *filp,
2369 void *dirent, filldir_t filldir,
2370 const struct pid_entry *ents, unsigned int nents)
2371 {
2372 int i;
2373 struct dentry *dentry = filp->f_path.dentry;
2374 struct inode *inode = dentry->d_inode;
2375 struct task_struct *task = get_proc_task(inode);
2376 const struct pid_entry *p, *last;
2377 ino_t ino;
2378 int ret;
2379
2380 ret = -ENOENT;
2381 if (!task)
2382 goto out_no_task;
2383
2384 ret = 0;
2385 i = filp->f_pos;
2386 switch (i) {
2387 case 0:
2388 ino = inode->i_ino;
2389 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2390 goto out;
2391 i++;
2392 filp->f_pos++;
2393 /* fall through */
2394 case 1:
2395 ino = parent_ino(dentry);
2396 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2397 goto out;
2398 i++;
2399 filp->f_pos++;
2400 /* fall through */
2401 default:
2402 i -= 2;
2403 if (i >= nents) {
2404 ret = 1;
2405 goto out;
2406 }
2407 p = ents + i;
2408 last = &ents[nents - 1];
2409 while (p <= last) {
2410 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2411 goto out;
2412 filp->f_pos++;
2413 p++;
2414 }
2415 }
2416
2417 ret = 1;
2418 out:
2419 put_task_struct(task);
2420 out_no_task:
2421 return ret;
2422 }
2423
2424 #ifdef CONFIG_SECURITY
2425 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2426 size_t count, loff_t *ppos)
2427 {
2428 struct inode * inode = file->f_path.dentry->d_inode;
2429 char *p = NULL;
2430 ssize_t length;
2431 struct task_struct *task = get_proc_task(inode);
2432
2433 if (!task)
2434 return -ESRCH;
2435
2436 length = security_getprocattr(task,
2437 (char*)file->f_path.dentry->d_name.name,
2438 &p);
2439 put_task_struct(task);
2440 if (length > 0)
2441 length = simple_read_from_buffer(buf, count, ppos, p, length);
2442 kfree(p);
2443 return length;
2444 }
2445
2446 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2447 size_t count, loff_t *ppos)
2448 {
2449 struct inode * inode = file->f_path.dentry->d_inode;
2450 char *page;
2451 ssize_t length;
2452 struct task_struct *task = get_proc_task(inode);
2453
2454 length = -ESRCH;
2455 if (!task)
2456 goto out_no_task;
2457 if (count > PAGE_SIZE)
2458 count = PAGE_SIZE;
2459
2460 /* No partial writes. */
2461 length = -EINVAL;
2462 if (*ppos != 0)
2463 goto out;
2464
2465 length = -ENOMEM;
2466 page = (char*)__get_free_page(GFP_TEMPORARY);
2467 if (!page)
2468 goto out;
2469
2470 length = -EFAULT;
2471 if (copy_from_user(page, buf, count))
2472 goto out_free;
2473
2474 /* Guard against adverse ptrace interaction */
2475 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2476 if (length < 0)
2477 goto out_free;
2478
2479 length = security_setprocattr(task,
2480 (char*)file->f_path.dentry->d_name.name,
2481 (void*)page, count);
2482 mutex_unlock(&task->signal->cred_guard_mutex);
2483 out_free:
2484 free_page((unsigned long) page);
2485 out:
2486 put_task_struct(task);
2487 out_no_task:
2488 return length;
2489 }
2490
2491 static const struct file_operations proc_pid_attr_operations = {
2492 .read = proc_pid_attr_read,
2493 .write = proc_pid_attr_write,
2494 .llseek = generic_file_llseek,
2495 };
2496
2497 static const struct pid_entry attr_dir_stuff[] = {
2498 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2499 REG("prev", S_IRUGO, proc_pid_attr_operations),
2500 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2501 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2502 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2503 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2504 };
2505
2506 static int proc_attr_dir_readdir(struct file * filp,
2507 void * dirent, filldir_t filldir)
2508 {
2509 return proc_pident_readdir(filp,dirent,filldir,
2510 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2511 }
2512
2513 static const struct file_operations proc_attr_dir_operations = {
2514 .read = generic_read_dir,
2515 .readdir = proc_attr_dir_readdir,
2516 .llseek = default_llseek,
2517 };
2518
2519 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2520 struct dentry *dentry, struct nameidata *nd)
2521 {
2522 return proc_pident_lookup(dir, dentry,
2523 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2524 }
2525
2526 static const struct inode_operations proc_attr_dir_inode_operations = {
2527 .lookup = proc_attr_dir_lookup,
2528 .getattr = pid_getattr,
2529 .setattr = proc_setattr,
2530 };
2531
2532 #endif
2533
2534 #ifdef CONFIG_ELF_CORE
2535 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2536 size_t count, loff_t *ppos)
2537 {
2538 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2539 struct mm_struct *mm;
2540 char buffer[PROC_NUMBUF];
2541 size_t len;
2542 int ret;
2543
2544 if (!task)
2545 return -ESRCH;
2546
2547 ret = 0;
2548 mm = get_task_mm(task);
2549 if (mm) {
2550 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2551 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2552 MMF_DUMP_FILTER_SHIFT));
2553 mmput(mm);
2554 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2555 }
2556
2557 put_task_struct(task);
2558
2559 return ret;
2560 }
2561
2562 static ssize_t proc_coredump_filter_write(struct file *file,
2563 const char __user *buf,
2564 size_t count,
2565 loff_t *ppos)
2566 {
2567 struct task_struct *task;
2568 struct mm_struct *mm;
2569 char buffer[PROC_NUMBUF], *end;
2570 unsigned int val;
2571 int ret;
2572 int i;
2573 unsigned long mask;
2574
2575 ret = -EFAULT;
2576 memset(buffer, 0, sizeof(buffer));
2577 if (count > sizeof(buffer) - 1)
2578 count = sizeof(buffer) - 1;
2579 if (copy_from_user(buffer, buf, count))
2580 goto out_no_task;
2581
2582 ret = -EINVAL;
2583 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2584 if (*end == '\n')
2585 end++;
2586 if (end - buffer == 0)
2587 goto out_no_task;
2588
2589 ret = -ESRCH;
2590 task = get_proc_task(file->f_dentry->d_inode);
2591 if (!task)
2592 goto out_no_task;
2593
2594 ret = end - buffer;
2595 mm = get_task_mm(task);
2596 if (!mm)
2597 goto out_no_mm;
2598
2599 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2600 if (val & mask)
2601 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2602 else
2603 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2604 }
2605
2606 mmput(mm);
2607 out_no_mm:
2608 put_task_struct(task);
2609 out_no_task:
2610 return ret;
2611 }
2612
2613 static const struct file_operations proc_coredump_filter_operations = {
2614 .read = proc_coredump_filter_read,
2615 .write = proc_coredump_filter_write,
2616 .llseek = generic_file_llseek,
2617 };
2618 #endif
2619
2620 /*
2621 * /proc/self:
2622 */
2623 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2624 int buflen)
2625 {
2626 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2627 pid_t tgid = task_tgid_nr_ns(current, ns);
2628 char tmp[PROC_NUMBUF];
2629 if (!tgid)
2630 return -ENOENT;
2631 sprintf(tmp, "%d", tgid);
2632 return vfs_readlink(dentry,buffer,buflen,tmp);
2633 }
2634
2635 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2636 {
2637 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2638 pid_t tgid = task_tgid_nr_ns(current, ns);
2639 char *name = ERR_PTR(-ENOENT);
2640 if (tgid) {
2641 name = __getname();
2642 if (!name)
2643 name = ERR_PTR(-ENOMEM);
2644 else
2645 sprintf(name, "%d", tgid);
2646 }
2647 nd_set_link(nd, name);
2648 return NULL;
2649 }
2650
2651 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2652 void *cookie)
2653 {
2654 char *s = nd_get_link(nd);
2655 if (!IS_ERR(s))
2656 __putname(s);
2657 }
2658
2659 static const struct inode_operations proc_self_inode_operations = {
2660 .readlink = proc_self_readlink,
2661 .follow_link = proc_self_follow_link,
2662 .put_link = proc_self_put_link,
2663 };
2664
2665 /*
2666 * proc base
2667 *
2668 * These are the directory entries in the root directory of /proc
2669 * that properly belong to the /proc filesystem, as they describe
2670 * describe something that is process related.
2671 */
2672 static const struct pid_entry proc_base_stuff[] = {
2673 NOD("self", S_IFLNK|S_IRWXUGO,
2674 &proc_self_inode_operations, NULL, {}),
2675 };
2676
2677 static struct dentry *proc_base_instantiate(struct inode *dir,
2678 struct dentry *dentry, struct task_struct *task, const void *ptr)
2679 {
2680 const struct pid_entry *p = ptr;
2681 struct inode *inode;
2682 struct proc_inode *ei;
2683 struct dentry *error;
2684
2685 /* Allocate the inode */
2686 error = ERR_PTR(-ENOMEM);
2687 inode = new_inode(dir->i_sb);
2688 if (!inode)
2689 goto out;
2690
2691 /* Initialize the inode */
2692 ei = PROC_I(inode);
2693 inode->i_ino = get_next_ino();
2694 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2695
2696 /*
2697 * grab the reference to the task.
2698 */
2699 ei->pid = get_task_pid(task, PIDTYPE_PID);
2700 if (!ei->pid)
2701 goto out_iput;
2702
2703 inode->i_mode = p->mode;
2704 if (S_ISDIR(inode->i_mode))
2705 inode->i_nlink = 2;
2706 if (S_ISLNK(inode->i_mode))
2707 inode->i_size = 64;
2708 if (p->iop)
2709 inode->i_op = p->iop;
2710 if (p->fop)
2711 inode->i_fop = p->fop;
2712 ei->op = p->op;
2713 d_add(dentry, inode);
2714 error = NULL;
2715 out:
2716 return error;
2717 out_iput:
2718 iput(inode);
2719 goto out;
2720 }
2721
2722 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2723 {
2724 struct dentry *error;
2725 struct task_struct *task = get_proc_task(dir);
2726 const struct pid_entry *p, *last;
2727
2728 error = ERR_PTR(-ENOENT);
2729
2730 if (!task)
2731 goto out_no_task;
2732
2733 /* Lookup the directory entry */
2734 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2735 for (p = proc_base_stuff; p <= last; p++) {
2736 if (p->len != dentry->d_name.len)
2737 continue;
2738 if (!memcmp(dentry->d_name.name, p->name, p->len))
2739 break;
2740 }
2741 if (p > last)
2742 goto out;
2743
2744 error = proc_base_instantiate(dir, dentry, task, p);
2745
2746 out:
2747 put_task_struct(task);
2748 out_no_task:
2749 return error;
2750 }
2751
2752 static int proc_base_fill_cache(struct file *filp, void *dirent,
2753 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2754 {
2755 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2756 proc_base_instantiate, task, p);
2757 }
2758
2759 #ifdef CONFIG_TASK_IO_ACCOUNTING
2760 static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2761 {
2762 struct task_io_accounting acct = task->ioac;
2763 unsigned long flags;
2764
2765 if (whole && lock_task_sighand(task, &flags)) {
2766 struct task_struct *t = task;
2767
2768 task_io_accounting_add(&acct, &task->signal->ioac);
2769 while_each_thread(task, t)
2770 task_io_accounting_add(&acct, &t->ioac);
2771
2772 unlock_task_sighand(task, &flags);
2773 }
2774 return sprintf(buffer,
2775 "rchar: %llu\n"
2776 "wchar: %llu\n"
2777 "syscr: %llu\n"
2778 "syscw: %llu\n"
2779 "read_bytes: %llu\n"
2780 "write_bytes: %llu\n"
2781 "cancelled_write_bytes: %llu\n",
2782 (unsigned long long)acct.rchar,
2783 (unsigned long long)acct.wchar,
2784 (unsigned long long)acct.syscr,
2785 (unsigned long long)acct.syscw,
2786 (unsigned long long)acct.read_bytes,
2787 (unsigned long long)acct.write_bytes,
2788 (unsigned long long)acct.cancelled_write_bytes);
2789 }
2790
2791 static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2792 {
2793 return do_io_accounting(task, buffer, 0);
2794 }
2795
2796 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2797 {
2798 return do_io_accounting(task, buffer, 1);
2799 }
2800 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2801
2802 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2803 struct pid *pid, struct task_struct *task)
2804 {
2805 int err = lock_trace(task);
2806 if (!err) {
2807 seq_printf(m, "%08x\n", task->personality);
2808 unlock_trace(task);
2809 }
2810 return err;
2811 }
2812
2813 /*
2814 * Thread groups
2815 */
2816 static const struct file_operations proc_task_operations;
2817 static const struct inode_operations proc_task_inode_operations;
2818
2819 static const struct pid_entry tgid_base_stuff[] = {
2820 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2821 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2822 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2823 #ifdef CONFIG_NET
2824 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2825 #endif
2826 REG("environ", S_IRUSR, proc_environ_operations),
2827 INF("auxv", S_IRUSR, proc_pid_auxv),
2828 ONE("status", S_IRUGO, proc_pid_status),
2829 ONE("personality", S_IRUGO, proc_pid_personality),
2830 INF("limits", S_IRUGO, proc_pid_limits),
2831 #ifdef CONFIG_SCHED_DEBUG
2832 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2833 #endif
2834 #ifdef CONFIG_SCHED_AUTOGROUP
2835 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2836 #endif
2837 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2838 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2839 INF("syscall", S_IRUGO, proc_pid_syscall),
2840 #endif
2841 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2842 ONE("stat", S_IRUGO, proc_tgid_stat),
2843 ONE("statm", S_IRUGO, proc_pid_statm),
2844 REG("maps", S_IRUGO, proc_maps_operations),
2845 #ifdef CONFIG_NUMA
2846 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
2847 #endif
2848 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2849 LNK("cwd", proc_cwd_link),
2850 LNK("root", proc_root_link),
2851 LNK("exe", proc_exe_link),
2852 REG("mounts", S_IRUGO, proc_mounts_operations),
2853 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2854 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2855 #ifdef CONFIG_PROC_PAGE_MONITOR
2856 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2857 REG("smaps", S_IRUGO, proc_smaps_operations),
2858 REG("pagemap", S_IRUGO, proc_pagemap_operations),
2859 #endif
2860 #ifdef CONFIG_SECURITY
2861 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2862 #endif
2863 #ifdef CONFIG_KALLSYMS
2864 INF("wchan", S_IRUGO, proc_pid_wchan),
2865 #endif
2866 #ifdef CONFIG_STACKTRACE
2867 ONE("stack", S_IRUGO, proc_pid_stack),
2868 #endif
2869 #ifdef CONFIG_SCHEDSTATS
2870 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2871 #endif
2872 #ifdef CONFIG_LATENCYTOP
2873 REG("latency", S_IRUGO, proc_lstats_operations),
2874 #endif
2875 #ifdef CONFIG_PROC_PID_CPUSET
2876 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2877 #endif
2878 #ifdef CONFIG_CGROUPS
2879 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2880 #endif
2881 INF("oom_score", S_IRUGO, proc_oom_score),
2882 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2883 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2884 #ifdef CONFIG_AUDITSYSCALL
2885 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2886 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2887 #endif
2888 #ifdef CONFIG_FAULT_INJECTION
2889 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2890 #endif
2891 #ifdef CONFIG_ELF_CORE
2892 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2893 #endif
2894 #ifdef CONFIG_TASK_IO_ACCOUNTING
2895 INF("io", S_IRUGO, proc_tgid_io_accounting),
2896 #endif
2897 };
2898
2899 static int proc_tgid_base_readdir(struct file * filp,
2900 void * dirent, filldir_t filldir)
2901 {
2902 return proc_pident_readdir(filp,dirent,filldir,
2903 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2904 }
2905
2906 static const struct file_operations proc_tgid_base_operations = {
2907 .read = generic_read_dir,
2908 .readdir = proc_tgid_base_readdir,
2909 .llseek = default_llseek,
2910 };
2911
2912 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2913 return proc_pident_lookup(dir, dentry,
2914 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2915 }
2916
2917 static const struct inode_operations proc_tgid_base_inode_operations = {
2918 .lookup = proc_tgid_base_lookup,
2919 .getattr = pid_getattr,
2920 .setattr = proc_setattr,
2921 };
2922
2923 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2924 {
2925 struct dentry *dentry, *leader, *dir;
2926 char buf[PROC_NUMBUF];
2927 struct qstr name;
2928
2929 name.name = buf;
2930 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2931 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2932 if (dentry) {
2933 shrink_dcache_parent(dentry);
2934 d_drop(dentry);
2935 dput(dentry);
2936 }
2937
2938 name.name = buf;
2939 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2940 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2941 if (!leader)
2942 goto out;
2943
2944 name.name = "task";
2945 name.len = strlen(name.name);
2946 dir = d_hash_and_lookup(leader, &name);
2947 if (!dir)
2948 goto out_put_leader;
2949
2950 name.name = buf;
2951 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2952 dentry = d_hash_and_lookup(dir, &name);
2953 if (dentry) {
2954 shrink_dcache_parent(dentry);
2955 d_drop(dentry);
2956 dput(dentry);
2957 }
2958
2959 dput(dir);
2960 out_put_leader:
2961 dput(leader);
2962 out:
2963 return;
2964 }
2965
2966 /**
2967 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2968 * @task: task that should be flushed.
2969 *
2970 * When flushing dentries from proc, one needs to flush them from global
2971 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2972 * in. This call is supposed to do all of this job.
2973 *
2974 * Looks in the dcache for
2975 * /proc/@pid
2976 * /proc/@tgid/task/@pid
2977 * if either directory is present flushes it and all of it'ts children
2978 * from the dcache.
2979 *
2980 * It is safe and reasonable to cache /proc entries for a task until
2981 * that task exits. After that they just clog up the dcache with
2982 * useless entries, possibly causing useful dcache entries to be
2983 * flushed instead. This routine is proved to flush those useless
2984 * dcache entries at process exit time.
2985 *
2986 * NOTE: This routine is just an optimization so it does not guarantee
2987 * that no dcache entries will exist at process exit time it
2988 * just makes it very unlikely that any will persist.
2989 */
2990
2991 void proc_flush_task(struct task_struct *task)
2992 {
2993 int i;
2994 struct pid *pid, *tgid;
2995 struct upid *upid;
2996
2997 pid = task_pid(task);
2998 tgid = task_tgid(task);
2999
3000 for (i = 0; i <= pid->level; i++) {
3001 upid = &pid->numbers[i];
3002 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3003 tgid->numbers[i].nr);
3004 }
3005
3006 upid = &pid->numbers[pid->level];
3007 if (upid->nr == 1)
3008 pid_ns_release_proc(upid->ns);
3009 }
3010
3011 static struct dentry *proc_pid_instantiate(struct inode *dir,
3012 struct dentry * dentry,
3013 struct task_struct *task, const void *ptr)
3014 {
3015 struct dentry *error = ERR_PTR(-ENOENT);
3016 struct inode *inode;
3017
3018 inode = proc_pid_make_inode(dir->i_sb, task);
3019 if (!inode)
3020 goto out;
3021
3022 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3023 inode->i_op = &proc_tgid_base_inode_operations;
3024 inode->i_fop = &proc_tgid_base_operations;
3025 inode->i_flags|=S_IMMUTABLE;
3026
3027 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
3028 ARRAY_SIZE(tgid_base_stuff));
3029
3030 d_set_d_op(dentry, &pid_dentry_operations);
3031
3032 d_add(dentry, inode);
3033 /* Close the race of the process dying before we return the dentry */
3034 if (pid_revalidate(dentry, NULL))
3035 error = NULL;
3036 out:
3037 return error;
3038 }
3039
3040 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3041 {
3042 struct dentry *result;
3043 struct task_struct *task;
3044 unsigned tgid;
3045 struct pid_namespace *ns;
3046
3047 result = proc_base_lookup(dir, dentry);
3048 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
3049 goto out;
3050
3051 tgid = name_to_int(dentry);
3052 if (tgid == ~0U)
3053 goto out;
3054
3055 ns = dentry->d_sb->s_fs_info;
3056 rcu_read_lock();
3057 task = find_task_by_pid_ns(tgid, ns);
3058 if (task)
3059 get_task_struct(task);
3060 rcu_read_unlock();
3061 if (!task)
3062 goto out;
3063
3064 result = proc_pid_instantiate(dir, dentry, task, NULL);
3065 put_task_struct(task);
3066 out:
3067 return result;
3068 }
3069
3070 /*
3071 * Find the first task with tgid >= tgid
3072 *
3073 */
3074 struct tgid_iter {
3075 unsigned int tgid;
3076 struct task_struct *task;
3077 };
3078 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3079 {
3080 struct pid *pid;
3081
3082 if (iter.task)
3083 put_task_struct(iter.task);
3084 rcu_read_lock();
3085 retry:
3086 iter.task = NULL;
3087 pid = find_ge_pid(iter.tgid, ns);
3088 if (pid) {
3089 iter.tgid = pid_nr_ns(pid, ns);
3090 iter.task = pid_task(pid, PIDTYPE_PID);
3091 /* What we to know is if the pid we have find is the
3092 * pid of a thread_group_leader. Testing for task
3093 * being a thread_group_leader is the obvious thing
3094 * todo but there is a window when it fails, due to
3095 * the pid transfer logic in de_thread.
3096 *
3097 * So we perform the straight forward test of seeing
3098 * if the pid we have found is the pid of a thread
3099 * group leader, and don't worry if the task we have
3100 * found doesn't happen to be a thread group leader.
3101 * As we don't care in the case of readdir.
3102 */
3103 if (!iter.task || !has_group_leader_pid(iter.task)) {
3104 iter.tgid += 1;
3105 goto retry;
3106 }
3107 get_task_struct(iter.task);
3108 }
3109 rcu_read_unlock();
3110 return iter;
3111 }
3112
3113 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
3114
3115 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3116 struct tgid_iter iter)
3117 {
3118 char name[PROC_NUMBUF];
3119 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
3120 return proc_fill_cache(filp, dirent, filldir, name, len,
3121 proc_pid_instantiate, iter.task, NULL);
3122 }
3123
3124 /* for the /proc/ directory itself, after non-process stuff has been done */
3125 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
3126 {
3127 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
3128 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode);
3129 struct tgid_iter iter;
3130 struct pid_namespace *ns;
3131
3132 if (!reaper)
3133 goto out_no_task;
3134
3135 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
3136 const struct pid_entry *p = &proc_base_stuff[nr];
3137 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
3138 goto out;
3139 }
3140
3141 ns = filp->f_dentry->d_sb->s_fs_info;
3142 iter.task = NULL;
3143 iter.tgid = filp->f_pos - TGID_OFFSET;
3144 for (iter = next_tgid(ns, iter);
3145 iter.task;
3146 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3147 filp->f_pos = iter.tgid + TGID_OFFSET;
3148 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
3149 put_task_struct(iter.task);
3150 goto out;
3151 }
3152 }
3153 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3154 out:
3155 put_task_struct(reaper);
3156 out_no_task:
3157 return 0;
3158 }
3159
3160 /*
3161 * Tasks
3162 */
3163 static const struct pid_entry tid_base_stuff[] = {
3164 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3165 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3166 REG("environ", S_IRUSR, proc_environ_operations),
3167 INF("auxv", S_IRUSR, proc_pid_auxv),
3168 ONE("status", S_IRUGO, proc_pid_status),
3169 ONE("personality", S_IRUGO, proc_pid_personality),
3170 INF("limits", S_IRUGO, proc_pid_limits),
3171 #ifdef CONFIG_SCHED_DEBUG
3172 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3173 #endif
3174 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3175 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3176 INF("syscall", S_IRUGO, proc_pid_syscall),
3177 #endif
3178 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3179 ONE("stat", S_IRUGO, proc_tid_stat),
3180 ONE("statm", S_IRUGO, proc_pid_statm),
3181 REG("maps", S_IRUGO, proc_maps_operations),
3182 #ifdef CONFIG_NUMA
3183 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
3184 #endif
3185 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3186 LNK("cwd", proc_cwd_link),
3187 LNK("root", proc_root_link),
3188 LNK("exe", proc_exe_link),
3189 REG("mounts", S_IRUGO, proc_mounts_operations),
3190 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3191 #ifdef CONFIG_PROC_PAGE_MONITOR
3192 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3193 REG("smaps", S_IRUGO, proc_smaps_operations),
3194 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3195 #endif
3196 #ifdef CONFIG_SECURITY
3197 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3198 #endif
3199 #ifdef CONFIG_KALLSYMS
3200 INF("wchan", S_IRUGO, proc_pid_wchan),
3201 #endif
3202 #ifdef CONFIG_STACKTRACE
3203 ONE("stack", S_IRUGO, proc_pid_stack),
3204 #endif
3205 #ifdef CONFIG_SCHEDSTATS
3206 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3207 #endif
3208 #ifdef CONFIG_LATENCYTOP
3209 REG("latency", S_IRUGO, proc_lstats_operations),
3210 #endif
3211 #ifdef CONFIG_PROC_PID_CPUSET
3212 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3213 #endif
3214 #ifdef CONFIG_CGROUPS
3215 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3216 #endif
3217 INF("oom_score", S_IRUGO, proc_oom_score),
3218 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3219 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3220 #ifdef CONFIG_AUDITSYSCALL
3221 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3222 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3223 #endif
3224 #ifdef CONFIG_FAULT_INJECTION
3225 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3226 #endif
3227 #ifdef CONFIG_TASK_IO_ACCOUNTING
3228 INF("io", S_IRUGO, proc_tid_io_accounting),
3229 #endif
3230 };
3231
3232 static int proc_tid_base_readdir(struct file * filp,
3233 void * dirent, filldir_t filldir)
3234 {
3235 return proc_pident_readdir(filp,dirent,filldir,
3236 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3237 }
3238
3239 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3240 return proc_pident_lookup(dir, dentry,
3241 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3242 }
3243
3244 static const struct file_operations proc_tid_base_operations = {
3245 .read = generic_read_dir,
3246 .readdir = proc_tid_base_readdir,
3247 .llseek = default_llseek,
3248 };
3249
3250 static const struct inode_operations proc_tid_base_inode_operations = {
3251 .lookup = proc_tid_base_lookup,
3252 .getattr = pid_getattr,
3253 .setattr = proc_setattr,
3254 };
3255
3256 static struct dentry *proc_task_instantiate(struct inode *dir,
3257 struct dentry *dentry, struct task_struct *task, const void *ptr)
3258 {
3259 struct dentry *error = ERR_PTR(-ENOENT);
3260 struct inode *inode;
3261 inode = proc_pid_make_inode(dir->i_sb, task);
3262
3263 if (!inode)
3264 goto out;
3265 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3266 inode->i_op = &proc_tid_base_inode_operations;
3267 inode->i_fop = &proc_tid_base_operations;
3268 inode->i_flags|=S_IMMUTABLE;
3269
3270 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
3271 ARRAY_SIZE(tid_base_stuff));
3272
3273 d_set_d_op(dentry, &pid_dentry_operations);
3274
3275 d_add(dentry, inode);
3276 /* Close the race of the process dying before we return the dentry */
3277 if (pid_revalidate(dentry, NULL))
3278 error = NULL;
3279 out:
3280 return error;
3281 }
3282
3283 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3284 {
3285 struct dentry *result = ERR_PTR(-ENOENT);
3286 struct task_struct *task;
3287 struct task_struct *leader = get_proc_task(dir);
3288 unsigned tid;
3289 struct pid_namespace *ns;
3290
3291 if (!leader)
3292 goto out_no_task;
3293
3294 tid = name_to_int(dentry);
3295 if (tid == ~0U)
3296 goto out;
3297
3298 ns = dentry->d_sb->s_fs_info;
3299 rcu_read_lock();
3300 task = find_task_by_pid_ns(tid, ns);
3301 if (task)
3302 get_task_struct(task);
3303 rcu_read_unlock();
3304 if (!task)
3305 goto out;
3306 if (!same_thread_group(leader, task))
3307 goto out_drop_task;
3308
3309 result = proc_task_instantiate(dir, dentry, task, NULL);
3310 out_drop_task:
3311 put_task_struct(task);
3312 out:
3313 put_task_struct(leader);
3314 out_no_task:
3315 return result;
3316 }
3317
3318 /*
3319 * Find the first tid of a thread group to return to user space.
3320 *
3321 * Usually this is just the thread group leader, but if the users
3322 * buffer was too small or there was a seek into the middle of the
3323 * directory we have more work todo.
3324 *
3325 * In the case of a short read we start with find_task_by_pid.
3326 *
3327 * In the case of a seek we start with the leader and walk nr
3328 * threads past it.
3329 */
3330 static struct task_struct *first_tid(struct task_struct *leader,
3331 int tid, int nr, struct pid_namespace *ns)
3332 {
3333 struct task_struct *pos;
3334
3335 rcu_read_lock();
3336 /* Attempt to start with the pid of a thread */
3337 if (tid && (nr > 0)) {
3338 pos = find_task_by_pid_ns(tid, ns);
3339 if (pos && (pos->group_leader == leader))
3340 goto found;
3341 }
3342
3343 /* If nr exceeds the number of threads there is nothing todo */
3344 pos = NULL;
3345 if (nr && nr >= get_nr_threads(leader))
3346 goto out;
3347
3348 /* If we haven't found our starting place yet start
3349 * with the leader and walk nr threads forward.
3350 */
3351 for (pos = leader; nr > 0; --nr) {
3352 pos = next_thread(pos);
3353 if (pos == leader) {
3354 pos = NULL;
3355 goto out;
3356 }
3357 }
3358 found:
3359 get_task_struct(pos);
3360 out:
3361 rcu_read_unlock();
3362 return pos;
3363 }
3364
3365 /*
3366 * Find the next thread in the thread list.
3367 * Return NULL if there is an error or no next thread.
3368 *
3369 * The reference to the input task_struct is released.
3370 */
3371 static struct task_struct *next_tid(struct task_struct *start)
3372 {
3373 struct task_struct *pos = NULL;
3374 rcu_read_lock();
3375 if (pid_alive(start)) {
3376 pos = next_thread(start);
3377 if (thread_group_leader(pos))
3378 pos = NULL;
3379 else
3380 get_task_struct(pos);
3381 }
3382 rcu_read_unlock();
3383 put_task_struct(start);
3384 return pos;
3385 }
3386
3387 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3388 struct task_struct *task, int tid)
3389 {
3390 char name[PROC_NUMBUF];
3391 int len = snprintf(name, sizeof(name), "%d", tid);
3392 return proc_fill_cache(filp, dirent, filldir, name, len,
3393 proc_task_instantiate, task, NULL);
3394 }
3395
3396 /* for the /proc/TGID/task/ directories */
3397 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3398 {
3399 struct dentry *dentry = filp->f_path.dentry;
3400 struct inode *inode = dentry->d_inode;
3401 struct task_struct *leader = NULL;
3402 struct task_struct *task;
3403 int retval = -ENOENT;
3404 ino_t ino;
3405 int tid;
3406 struct pid_namespace *ns;
3407
3408 task = get_proc_task(inode);
3409 if (!task)
3410 goto out_no_task;
3411 rcu_read_lock();
3412 if (pid_alive(task)) {
3413 leader = task->group_leader;
3414 get_task_struct(leader);
3415 }
3416 rcu_read_unlock();
3417 put_task_struct(task);
3418 if (!leader)
3419 goto out_no_task;
3420 retval = 0;
3421
3422 switch ((unsigned long)filp->f_pos) {
3423 case 0:
3424 ino = inode->i_ino;
3425 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3426 goto out;
3427 filp->f_pos++;
3428 /* fall through */
3429 case 1:
3430 ino = parent_ino(dentry);
3431 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3432 goto out;
3433 filp->f_pos++;
3434 /* fall through */
3435 }
3436
3437 /* f_version caches the tgid value that the last readdir call couldn't
3438 * return. lseek aka telldir automagically resets f_version to 0.
3439 */
3440 ns = filp->f_dentry->d_sb->s_fs_info;
3441 tid = (int)filp->f_version;
3442 filp->f_version = 0;
3443 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3444 task;
3445 task = next_tid(task), filp->f_pos++) {
3446 tid = task_pid_nr_ns(task, ns);
3447 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3448 /* returning this tgid failed, save it as the first
3449 * pid for the next readir call */
3450 filp->f_version = (u64)tid;
3451 put_task_struct(task);
3452 break;
3453 }
3454 }
3455 out:
3456 put_task_struct(leader);
3457 out_no_task:
3458 return retval;
3459 }
3460
3461 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3462 {
3463 struct inode *inode = dentry->d_inode;
3464 struct task_struct *p = get_proc_task(inode);
3465 generic_fillattr(inode, stat);
3466
3467 if (p) {
3468 stat->nlink += get_nr_threads(p);
3469 put_task_struct(p);
3470 }
3471
3472 return 0;
3473 }
3474
3475 static const struct inode_operations proc_task_inode_operations = {
3476 .lookup = proc_task_lookup,
3477 .getattr = proc_task_getattr,
3478 .setattr = proc_setattr,
3479 };
3480
3481 static const struct file_operations proc_task_operations = {
3482 .read = generic_read_dir,
3483 .readdir = proc_task_readdir,
3484 .llseek = default_llseek,
3485 };
CRIS linux kernel tree