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Merge branch 'master' of git://git2.kernel.org/pub/scm/linux/kernel/git/torvalds...
[linux-2.6/linux-2.6-openrd.git] / fs / proc / base.c
blobe42bbd843ed13793e93a9af193e8b14136013d31
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/rcupdate.h>
67 #include <linux/kallsyms.h>
68 #include <linux/stacktrace.h>
69 #include <linux/resource.h>
70 #include <linux/module.h>
71 #include <linux/mount.h>
72 #include <linux/security.h>
73 #include <linux/ptrace.h>
74 #include <linux/tracehook.h>
75 #include <linux/cgroup.h>
76 #include <linux/cpuset.h>
77 #include <linux/audit.h>
78 #include <linux/poll.h>
79 #include <linux/nsproxy.h>
80 #include <linux/oom.h>
81 #include <linux/elf.h>
82 #include <linux/pid_namespace.h>
83 #include <linux/fs_struct.h>
84 #include "internal.h"
85
86 /* NOTE:
87 * Implementing inode permission operations in /proc is almost
88 * certainly an error. Permission checks need to happen during
89 * each system call not at open time. The reason is that most of
90 * what we wish to check for permissions in /proc varies at runtime.
91 *
92 * The classic example of a problem is opening file descriptors
93 * in /proc for a task before it execs a suid executable.
94 */
95
96 struct pid_entry {
97 char *name;
98 int len;
99 mode_t mode;
100 const struct inode_operations *iop;
101 const struct file_operations *fop;
102 union proc_op op;
103 };
104
105 #define NOD(NAME, MODE, IOP, FOP, OP) { \
106 .name = (NAME), \
107 .len = sizeof(NAME) - 1, \
108 .mode = MODE, \
109 .iop = IOP, \
110 .fop = FOP, \
111 .op = OP, \
112 }
113
114 #define DIR(NAME, MODE, iops, fops) \
115 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
116 #define LNK(NAME, get_link) \
117 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
118 &proc_pid_link_inode_operations, NULL, \
119 { .proc_get_link = get_link } )
120 #define REG(NAME, MODE, fops) \
121 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
122 #define INF(NAME, MODE, read) \
123 NOD(NAME, (S_IFREG|(MODE)), \
124 NULL, &proc_info_file_operations, \
125 { .proc_read = read } )
126 #define ONE(NAME, MODE, show) \
127 NOD(NAME, (S_IFREG|(MODE)), \
128 NULL, &proc_single_file_operations, \
129 { .proc_show = show } )
130
131 /*
132 * Count the number of hardlinks for the pid_entry table, excluding the .
133 * and .. links.
134 */
135 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
136 unsigned int n)
137 {
138 unsigned int i;
139 unsigned int count;
140
141 count = 0;
142 for (i = 0; i < n; ++i) {
143 if (S_ISDIR(entries[i].mode))
144 ++count;
145 }
146
147 return count;
148 }
149
150 static int get_fs_path(struct task_struct *task, struct path *path, bool root)
151 {
152 struct fs_struct *fs;
153 int result = -ENOENT;
154
155 task_lock(task);
156 fs = task->fs;
157 if (fs) {
158 read_lock(&fs->lock);
159 *path = root ? fs->root : fs->pwd;
160 path_get(path);
161 read_unlock(&fs->lock);
162 result = 0;
163 }
164 task_unlock(task);
165 return result;
166 }
167
168 static int get_nr_threads(struct task_struct *tsk)
169 {
170 unsigned long flags;
171 int count = 0;
172
173 if (lock_task_sighand(tsk, &flags)) {
174 count = atomic_read(&tsk->signal->count);
175 unlock_task_sighand(tsk, &flags);
176 }
177 return count;
178 }
179
180 static int proc_cwd_link(struct inode *inode, struct path *path)
181 {
182 struct task_struct *task = get_proc_task(inode);
183 int result = -ENOENT;
184
185 if (task) {
186 result = get_fs_path(task, path, 0);
187 put_task_struct(task);
188 }
189 return result;
190 }
191
192 static int proc_root_link(struct inode *inode, struct path *path)
193 {
194 struct task_struct *task = get_proc_task(inode);
195 int result = -ENOENT;
196
197 if (task) {
198 result = get_fs_path(task, path, 1);
199 put_task_struct(task);
200 }
201 return result;
202 }
203
204 /*
205 * Return zero if current may access user memory in @task, -error if not.
206 */
207 static int check_mem_permission(struct task_struct *task)
208 {
209 /*
210 * A task can always look at itself, in case it chooses
211 * to use system calls instead of load instructions.
212 */
213 if (task == current)
214 return 0;
215
216 /*
217 * If current is actively ptrace'ing, and would also be
218 * permitted to freshly attach with ptrace now, permit it.
219 */
220 if (task_is_stopped_or_traced(task)) {
221 int match;
222 rcu_read_lock();
223 match = (tracehook_tracer_task(task) == current);
224 rcu_read_unlock();
225 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
226 return 0;
227 }
228
229 /*
230 * Noone else is allowed.
231 */
232 return -EPERM;
233 }
234
235 struct mm_struct *mm_for_maps(struct task_struct *task)
236 {
237 struct mm_struct *mm;
238
239 if (mutex_lock_killable(&task->cred_guard_mutex))
240 return NULL;
241
242 mm = get_task_mm(task);
243 if (mm && mm != current->mm &&
244 !ptrace_may_access(task, PTRACE_MODE_READ)) {
245 mmput(mm);
246 mm = NULL;
247 }
248 mutex_unlock(&task->cred_guard_mutex);
249
250 return mm;
251 }
252
253 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
254 {
255 int res = 0;
256 unsigned int len;
257 struct mm_struct *mm = get_task_mm(task);
258 if (!mm)
259 goto out;
260 if (!mm->arg_end)
261 goto out_mm; /* Shh! No looking before we're done */
262
263 len = mm->arg_end - mm->arg_start;
264
265 if (len > PAGE_SIZE)
266 len = PAGE_SIZE;
267
268 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
269
270 // If the nul at the end of args has been overwritten, then
271 // assume application is using setproctitle(3).
272 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
273 len = strnlen(buffer, res);
274 if (len < res) {
275 res = len;
276 } else {
277 len = mm->env_end - mm->env_start;
278 if (len > PAGE_SIZE - res)
279 len = PAGE_SIZE - res;
280 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
281 res = strnlen(buffer, res);
282 }
283 }
284 out_mm:
285 mmput(mm);
286 out:
287 return res;
288 }
289
290 static int proc_pid_auxv(struct task_struct *task, char *buffer)
291 {
292 int res = 0;
293 struct mm_struct *mm = get_task_mm(task);
294 if (mm) {
295 unsigned int nwords = 0;
296 do {
297 nwords += 2;
298 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
299 res = nwords * sizeof(mm->saved_auxv[0]);
300 if (res > PAGE_SIZE)
301 res = PAGE_SIZE;
302 memcpy(buffer, mm->saved_auxv, res);
303 mmput(mm);
304 }
305 return res;
306 }
307
308
309 #ifdef CONFIG_KALLSYMS
310 /*
311 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
312 * Returns the resolved symbol. If that fails, simply return the address.
313 */
314 static int proc_pid_wchan(struct task_struct *task, char *buffer)
315 {
316 unsigned long wchan;
317 char symname[KSYM_NAME_LEN];
318
319 wchan = get_wchan(task);
320
321 if (lookup_symbol_name(wchan, symname) < 0)
322 if (!ptrace_may_access(task, PTRACE_MODE_READ))
323 return 0;
324 else
325 return sprintf(buffer, "%lu", wchan);
326 else
327 return sprintf(buffer, "%s", symname);
328 }
329 #endif /* CONFIG_KALLSYMS */
330
331 #ifdef CONFIG_STACKTRACE
332
333 #define MAX_STACK_TRACE_DEPTH 64
334
335 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
336 struct pid *pid, struct task_struct *task)
337 {
338 struct stack_trace trace;
339 unsigned long *entries;
340 int i;
341
342 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
343 if (!entries)
344 return -ENOMEM;
345
346 trace.nr_entries = 0;
347 trace.max_entries = MAX_STACK_TRACE_DEPTH;
348 trace.entries = entries;
349 trace.skip = 0;
350 save_stack_trace_tsk(task, &trace);
351
352 for (i = 0; i < trace.nr_entries; i++) {
353 seq_printf(m, "[<%p>] %pS\n",
354 (void *)entries[i], (void *)entries[i]);
355 }
356 kfree(entries);
357
358 return 0;
359 }
360 #endif
361
362 #ifdef CONFIG_SCHEDSTATS
363 /*
364 * Provides /proc/PID/schedstat
365 */
366 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
367 {
368 return sprintf(buffer, "%llu %llu %lu\n",
369 (unsigned long long)task->se.sum_exec_runtime,
370 (unsigned long long)task->sched_info.run_delay,
371 task->sched_info.pcount);
372 }
373 #endif
374
375 #ifdef CONFIG_LATENCYTOP
376 static int lstats_show_proc(struct seq_file *m, void *v)
377 {
378 int i;
379 struct inode *inode = m->private;
380 struct task_struct *task = get_proc_task(inode);
381
382 if (!task)
383 return -ESRCH;
384 seq_puts(m, "Latency Top version : v0.1\n");
385 for (i = 0; i < 32; i++) {
386 if (task->latency_record[i].backtrace[0]) {
387 int q;
388 seq_printf(m, "%i %li %li ",
389 task->latency_record[i].count,
390 task->latency_record[i].time,
391 task->latency_record[i].max);
392 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
393 char sym[KSYM_SYMBOL_LEN];
394 char *c;
395 if (!task->latency_record[i].backtrace[q])
396 break;
397 if (task->latency_record[i].backtrace[q] == ULONG_MAX)
398 break;
399 sprint_symbol(sym, task->latency_record[i].backtrace[q]);
400 c = strchr(sym, '+');
401 if (c)
402 *c = 0;
403 seq_printf(m, "%s ", sym);
404 }
405 seq_printf(m, "\n");
406 }
407
408 }
409 put_task_struct(task);
410 return 0;
411 }
412
413 static int lstats_open(struct inode *inode, struct file *file)
414 {
415 return single_open(file, lstats_show_proc, inode);
416 }
417
418 static ssize_t lstats_write(struct file *file, const char __user *buf,
419 size_t count, loff_t *offs)
420 {
421 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
422
423 if (!task)
424 return -ESRCH;
425 clear_all_latency_tracing(task);
426 put_task_struct(task);
427
428 return count;
429 }
430
431 static const struct file_operations proc_lstats_operations = {
432 .open = lstats_open,
433 .read = seq_read,
434 .write = lstats_write,
435 .llseek = seq_lseek,
436 .release = single_release,
437 };
438
439 #endif
440
441 /* The badness from the OOM killer */
442 unsigned long badness(struct task_struct *p, unsigned long uptime);
443 static int proc_oom_score(struct task_struct *task, char *buffer)
444 {
445 unsigned long points;
446 struct timespec uptime;
447
448 do_posix_clock_monotonic_gettime(&uptime);
449 read_lock(&tasklist_lock);
450 points = badness(task->group_leader, uptime.tv_sec);
451 read_unlock(&tasklist_lock);
452 return sprintf(buffer, "%lu\n", points);
453 }
454
455 struct limit_names {
456 char *name;
457 char *unit;
458 };
459
460 static const struct limit_names lnames[RLIM_NLIMITS] = {
461 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
462 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
463 [RLIMIT_DATA] = {"Max data size", "bytes"},
464 [RLIMIT_STACK] = {"Max stack size", "bytes"},
465 [RLIMIT_CORE] = {"Max core file size", "bytes"},
466 [RLIMIT_RSS] = {"Max resident set", "bytes"},
467 [RLIMIT_NPROC] = {"Max processes", "processes"},
468 [RLIMIT_NOFILE] = {"Max open files", "files"},
469 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
470 [RLIMIT_AS] = {"Max address space", "bytes"},
471 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
472 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
473 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
474 [RLIMIT_NICE] = {"Max nice priority", NULL},
475 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
476 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
477 };
478
479 /* Display limits for a process */
480 static int proc_pid_limits(struct task_struct *task, char *buffer)
481 {
482 unsigned int i;
483 int count = 0;
484 unsigned long flags;
485 char *bufptr = buffer;
486
487 struct rlimit rlim[RLIM_NLIMITS];
488
489 if (!lock_task_sighand(task, &flags))
490 return 0;
491 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
492 unlock_task_sighand(task, &flags);
493
494 /*
495 * print the file header
496 */
497 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
498 "Limit", "Soft Limit", "Hard Limit", "Units");
499
500 for (i = 0; i < RLIM_NLIMITS; i++) {
501 if (rlim[i].rlim_cur == RLIM_INFINITY)
502 count += sprintf(&bufptr[count], "%-25s %-20s ",
503 lnames[i].name, "unlimited");
504 else
505 count += sprintf(&bufptr[count], "%-25s %-20lu ",
506 lnames[i].name, rlim[i].rlim_cur);
507
508 if (rlim[i].rlim_max == RLIM_INFINITY)
509 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
510 else
511 count += sprintf(&bufptr[count], "%-20lu ",
512 rlim[i].rlim_max);
513
514 if (lnames[i].unit)
515 count += sprintf(&bufptr[count], "%-10s\n",
516 lnames[i].unit);
517 else
518 count += sprintf(&bufptr[count], "\n");
519 }
520
521 return count;
522 }
523
524 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
525 static int proc_pid_syscall(struct task_struct *task, char *buffer)
526 {
527 long nr;
528 unsigned long args[6], sp, pc;
529
530 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
531 return sprintf(buffer, "running\n");
532
533 if (nr < 0)
534 return sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
535
536 return sprintf(buffer,
537 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
538 nr,
539 args[0], args[1], args[2], args[3], args[4], args[5],
540 sp, pc);
541 }
542 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
543
544 /************************************************************************/
545 /* Here the fs part begins */
546 /************************************************************************/
547
548 /* permission checks */
549 static int proc_fd_access_allowed(struct inode *inode)
550 {
551 struct task_struct *task;
552 int allowed = 0;
553 /* Allow access to a task's file descriptors if it is us or we
554 * may use ptrace attach to the process and find out that
555 * information.
556 */
557 task = get_proc_task(inode);
558 if (task) {
559 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
560 put_task_struct(task);
561 }
562 return allowed;
563 }
564
565 static int proc_setattr(struct dentry *dentry, struct iattr *attr)
566 {
567 int error;
568 struct inode *inode = dentry->d_inode;
569
570 if (attr->ia_valid & ATTR_MODE)
571 return -EPERM;
572
573 error = inode_change_ok(inode, attr);
574 if (!error)
575 error = inode_setattr(inode, attr);
576 return error;
577 }
578
579 static const struct inode_operations proc_def_inode_operations = {
580 .setattr = proc_setattr,
581 };
582
583 static int mounts_open_common(struct inode *inode, struct file *file,
584 const struct seq_operations *op)
585 {
586 struct task_struct *task = get_proc_task(inode);
587 struct nsproxy *nsp;
588 struct mnt_namespace *ns = NULL;
589 struct path root;
590 struct proc_mounts *p;
591 int ret = -EINVAL;
592
593 if (task) {
594 rcu_read_lock();
595 nsp = task_nsproxy(task);
596 if (nsp) {
597 ns = nsp->mnt_ns;
598 if (ns)
599 get_mnt_ns(ns);
600 }
601 rcu_read_unlock();
602 if (ns && get_fs_path(task, &root, 1) == 0)
603 ret = 0;
604 put_task_struct(task);
605 }
606
607 if (!ns)
608 goto err;
609 if (ret)
610 goto err_put_ns;
611
612 ret = -ENOMEM;
613 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
614 if (!p)
615 goto err_put_path;
616
617 file->private_data = &p->m;
618 ret = seq_open(file, op);
619 if (ret)
620 goto err_free;
621
622 p->m.private = p;
623 p->ns = ns;
624 p->root = root;
625 p->event = ns->event;
626
627 return 0;
628
629 err_free:
630 kfree(p);
631 err_put_path:
632 path_put(&root);
633 err_put_ns:
634 put_mnt_ns(ns);
635 err:
636 return ret;
637 }
638
639 static int mounts_release(struct inode *inode, struct file *file)
640 {
641 struct proc_mounts *p = file->private_data;
642 path_put(&p->root);
643 put_mnt_ns(p->ns);
644 return seq_release(inode, file);
645 }
646
647 static unsigned mounts_poll(struct file *file, poll_table *wait)
648 {
649 struct proc_mounts *p = file->private_data;
650 struct mnt_namespace *ns = p->ns;
651 unsigned res = POLLIN | POLLRDNORM;
652
653 poll_wait(file, &ns->poll, wait);
654
655 spin_lock(&vfsmount_lock);
656 if (p->event != ns->event) {
657 p->event = ns->event;
658 res |= POLLERR | POLLPRI;
659 }
660 spin_unlock(&vfsmount_lock);
661
662 return res;
663 }
664
665 static int mounts_open(struct inode *inode, struct file *file)
666 {
667 return mounts_open_common(inode, file, &mounts_op);
668 }
669
670 static const struct file_operations proc_mounts_operations = {
671 .open = mounts_open,
672 .read = seq_read,
673 .llseek = seq_lseek,
674 .release = mounts_release,
675 .poll = mounts_poll,
676 };
677
678 static int mountinfo_open(struct inode *inode, struct file *file)
679 {
680 return mounts_open_common(inode, file, &mountinfo_op);
681 }
682
683 static const struct file_operations proc_mountinfo_operations = {
684 .open = mountinfo_open,
685 .read = seq_read,
686 .llseek = seq_lseek,
687 .release = mounts_release,
688 .poll = mounts_poll,
689 };
690
691 static int mountstats_open(struct inode *inode, struct file *file)
692 {
693 return mounts_open_common(inode, file, &mountstats_op);
694 }
695
696 static const struct file_operations proc_mountstats_operations = {
697 .open = mountstats_open,
698 .read = seq_read,
699 .llseek = seq_lseek,
700 .release = mounts_release,
701 };
702
703 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
704
705 static ssize_t proc_info_read(struct file * file, char __user * buf,
706 size_t count, loff_t *ppos)
707 {
708 struct inode * inode = file->f_path.dentry->d_inode;
709 unsigned long page;
710 ssize_t length;
711 struct task_struct *task = get_proc_task(inode);
712
713 length = -ESRCH;
714 if (!task)
715 goto out_no_task;
716
717 if (count > PROC_BLOCK_SIZE)
718 count = PROC_BLOCK_SIZE;
719
720 length = -ENOMEM;
721 if (!(page = __get_free_page(GFP_TEMPORARY)))
722 goto out;
723
724 length = PROC_I(inode)->op.proc_read(task, (char*)page);
725
726 if (length >= 0)
727 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
728 free_page(page);
729 out:
730 put_task_struct(task);
731 out_no_task:
732 return length;
733 }
734
735 static const struct file_operations proc_info_file_operations = {
736 .read = proc_info_read,
737 };
738
739 static int proc_single_show(struct seq_file *m, void *v)
740 {
741 struct inode *inode = m->private;
742 struct pid_namespace *ns;
743 struct pid *pid;
744 struct task_struct *task;
745 int ret;
746
747 ns = inode->i_sb->s_fs_info;
748 pid = proc_pid(inode);
749 task = get_pid_task(pid, PIDTYPE_PID);
750 if (!task)
751 return -ESRCH;
752
753 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
754
755 put_task_struct(task);
756 return ret;
757 }
758
759 static int proc_single_open(struct inode *inode, struct file *filp)
760 {
761 int ret;
762 ret = single_open(filp, proc_single_show, NULL);
763 if (!ret) {
764 struct seq_file *m = filp->private_data;
765
766 m->private = inode;
767 }
768 return ret;
769 }
770
771 static const struct file_operations proc_single_file_operations = {
772 .open = proc_single_open,
773 .read = seq_read,
774 .llseek = seq_lseek,
775 .release = single_release,
776 };
777
778 static int mem_open(struct inode* inode, struct file* file)
779 {
780 file->private_data = (void*)((long)current->self_exec_id);
781 return 0;
782 }
783
784 static ssize_t mem_read(struct file * file, char __user * buf,
785 size_t count, loff_t *ppos)
786 {
787 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
788 char *page;
789 unsigned long src = *ppos;
790 int ret = -ESRCH;
791 struct mm_struct *mm;
792
793 if (!task)
794 goto out_no_task;
795
796 if (check_mem_permission(task))
797 goto out;
798
799 ret = -ENOMEM;
800 page = (char *)__get_free_page(GFP_TEMPORARY);
801 if (!page)
802 goto out;
803
804 ret = 0;
805
806 mm = get_task_mm(task);
807 if (!mm)
808 goto out_free;
809
810 ret = -EIO;
811
812 if (file->private_data != (void*)((long)current->self_exec_id))
813 goto out_put;
814
815 ret = 0;
816
817 while (count > 0) {
818 int this_len, retval;
819
820 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
821 retval = access_process_vm(task, src, page, this_len, 0);
822 if (!retval || check_mem_permission(task)) {
823 if (!ret)
824 ret = -EIO;
825 break;
826 }
827
828 if (copy_to_user(buf, page, retval)) {
829 ret = -EFAULT;
830 break;
831 }
832
833 ret += retval;
834 src += retval;
835 buf += retval;
836 count -= retval;
837 }
838 *ppos = src;
839
840 out_put:
841 mmput(mm);
842 out_free:
843 free_page((unsigned long) page);
844 out:
845 put_task_struct(task);
846 out_no_task:
847 return ret;
848 }
849
850 #define mem_write NULL
851
852 #ifndef mem_write
853 /* This is a security hazard */
854 static ssize_t mem_write(struct file * file, const char __user *buf,
855 size_t count, loff_t *ppos)
856 {
857 int copied;
858 char *page;
859 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
860 unsigned long dst = *ppos;
861
862 copied = -ESRCH;
863 if (!task)
864 goto out_no_task;
865
866 if (check_mem_permission(task))
867 goto out;
868
869 copied = -ENOMEM;
870 page = (char *)__get_free_page(GFP_TEMPORARY);
871 if (!page)
872 goto out;
873
874 copied = 0;
875 while (count > 0) {
876 int this_len, retval;
877
878 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
879 if (copy_from_user(page, buf, this_len)) {
880 copied = -EFAULT;
881 break;
882 }
883 retval = access_process_vm(task, dst, page, this_len, 1);
884 if (!retval) {
885 if (!copied)
886 copied = -EIO;
887 break;
888 }
889 copied += retval;
890 buf += retval;
891 dst += retval;
892 count -= retval;
893 }
894 *ppos = dst;
895 free_page((unsigned long) page);
896 out:
897 put_task_struct(task);
898 out_no_task:
899 return copied;
900 }
901 #endif
902
903 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
904 {
905 switch (orig) {
906 case 0:
907 file->f_pos = offset;
908 break;
909 case 1:
910 file->f_pos += offset;
911 break;
912 default:
913 return -EINVAL;
914 }
915 force_successful_syscall_return();
916 return file->f_pos;
917 }
918
919 static const struct file_operations proc_mem_operations = {
920 .llseek = mem_lseek,
921 .read = mem_read,
922 .write = mem_write,
923 .open = mem_open,
924 };
925
926 static ssize_t environ_read(struct file *file, char __user *buf,
927 size_t count, loff_t *ppos)
928 {
929 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
930 char *page;
931 unsigned long src = *ppos;
932 int ret = -ESRCH;
933 struct mm_struct *mm;
934
935 if (!task)
936 goto out_no_task;
937
938 if (!ptrace_may_access(task, PTRACE_MODE_READ))
939 goto out;
940
941 ret = -ENOMEM;
942 page = (char *)__get_free_page(GFP_TEMPORARY);
943 if (!page)
944 goto out;
945
946 ret = 0;
947
948 mm = get_task_mm(task);
949 if (!mm)
950 goto out_free;
951
952 while (count > 0) {
953 int this_len, retval, max_len;
954
955 this_len = mm->env_end - (mm->env_start + src);
956
957 if (this_len <= 0)
958 break;
959
960 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
961 this_len = (this_len > max_len) ? max_len : this_len;
962
963 retval = access_process_vm(task, (mm->env_start + src),
964 page, this_len, 0);
965
966 if (retval <= 0) {
967 ret = retval;
968 break;
969 }
970
971 if (copy_to_user(buf, page, retval)) {
972 ret = -EFAULT;
973 break;
974 }
975
976 ret += retval;
977 src += retval;
978 buf += retval;
979 count -= retval;
980 }
981 *ppos = src;
982
983 mmput(mm);
984 out_free:
985 free_page((unsigned long) page);
986 out:
987 put_task_struct(task);
988 out_no_task:
989 return ret;
990 }
991
992 static const struct file_operations proc_environ_operations = {
993 .read = environ_read,
994 };
995
996 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
997 size_t count, loff_t *ppos)
998 {
999 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1000 char buffer[PROC_NUMBUF];
1001 size_t len;
1002 int oom_adjust = OOM_DISABLE;
1003 unsigned long flags;
1004
1005 if (!task)
1006 return -ESRCH;
1007
1008 if (lock_task_sighand(task, &flags)) {
1009 oom_adjust = task->signal->oom_adj;
1010 unlock_task_sighand(task, &flags);
1011 }
1012
1013 put_task_struct(task);
1014
1015 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
1016
1017 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1018 }
1019
1020 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
1021 size_t count, loff_t *ppos)
1022 {
1023 struct task_struct *task;
1024 char buffer[PROC_NUMBUF];
1025 long oom_adjust;
1026 unsigned long flags;
1027 int err;
1028
1029 memset(buffer, 0, sizeof(buffer));
1030 if (count > sizeof(buffer) - 1)
1031 count = sizeof(buffer) - 1;
1032 if (copy_from_user(buffer, buf, count))
1033 return -EFAULT;
1034
1035 err = strict_strtol(strstrip(buffer), 0, &oom_adjust);
1036 if (err)
1037 return -EINVAL;
1038 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
1039 oom_adjust != OOM_DISABLE)
1040 return -EINVAL;
1041
1042 task = get_proc_task(file->f_path.dentry->d_inode);
1043 if (!task)
1044 return -ESRCH;
1045 if (!lock_task_sighand(task, &flags)) {
1046 put_task_struct(task);
1047 return -ESRCH;
1048 }
1049
1050 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
1051 unlock_task_sighand(task, &flags);
1052 put_task_struct(task);
1053 return -EACCES;
1054 }
1055
1056 task->signal->oom_adj = oom_adjust;
1057
1058 unlock_task_sighand(task, &flags);
1059 put_task_struct(task);
1060
1061 return count;
1062 }
1063
1064 static const struct file_operations proc_oom_adjust_operations = {
1065 .read = oom_adjust_read,
1066 .write = oom_adjust_write,
1067 };
1068
1069 #ifdef CONFIG_AUDITSYSCALL
1070 #define TMPBUFLEN 21
1071 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1072 size_t count, loff_t *ppos)
1073 {
1074 struct inode * inode = file->f_path.dentry->d_inode;
1075 struct task_struct *task = get_proc_task(inode);
1076 ssize_t length;
1077 char tmpbuf[TMPBUFLEN];
1078
1079 if (!task)
1080 return -ESRCH;
1081 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1082 audit_get_loginuid(task));
1083 put_task_struct(task);
1084 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1085 }
1086
1087 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1088 size_t count, loff_t *ppos)
1089 {
1090 struct inode * inode = file->f_path.dentry->d_inode;
1091 char *page, *tmp;
1092 ssize_t length;
1093 uid_t loginuid;
1094
1095 if (!capable(CAP_AUDIT_CONTROL))
1096 return -EPERM;
1097
1098 if (current != pid_task(proc_pid(inode), PIDTYPE_PID))
1099 return -EPERM;
1100
1101 if (count >= PAGE_SIZE)
1102 count = PAGE_SIZE - 1;
1103
1104 if (*ppos != 0) {
1105 /* No partial writes. */
1106 return -EINVAL;
1107 }
1108 page = (char*)__get_free_page(GFP_TEMPORARY);
1109 if (!page)
1110 return -ENOMEM;
1111 length = -EFAULT;
1112 if (copy_from_user(page, buf, count))
1113 goto out_free_page;
1114
1115 page[count] = '\0';
1116 loginuid = simple_strtoul(page, &tmp, 10);
1117 if (tmp == page) {
1118 length = -EINVAL;
1119 goto out_free_page;
1120
1121 }
1122 length = audit_set_loginuid(current, loginuid);
1123 if (likely(length == 0))
1124 length = count;
1125
1126 out_free_page:
1127 free_page((unsigned long) page);
1128 return length;
1129 }
1130
1131 static const struct file_operations proc_loginuid_operations = {
1132 .read = proc_loginuid_read,
1133 .write = proc_loginuid_write,
1134 };
1135
1136 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1137 size_t count, loff_t *ppos)
1138 {
1139 struct inode * inode = file->f_path.dentry->d_inode;
1140 struct task_struct *task = get_proc_task(inode);
1141 ssize_t length;
1142 char tmpbuf[TMPBUFLEN];
1143
1144 if (!task)
1145 return -ESRCH;
1146 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1147 audit_get_sessionid(task));
1148 put_task_struct(task);
1149 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1150 }
1151
1152 static const struct file_operations proc_sessionid_operations = {
1153 .read = proc_sessionid_read,
1154 };
1155 #endif
1156
1157 #ifdef CONFIG_FAULT_INJECTION
1158 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1159 size_t count, loff_t *ppos)
1160 {
1161 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1162 char buffer[PROC_NUMBUF];
1163 size_t len;
1164 int make_it_fail;
1165
1166 if (!task)
1167 return -ESRCH;
1168 make_it_fail = task->make_it_fail;
1169 put_task_struct(task);
1170
1171 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1172
1173 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1174 }
1175
1176 static ssize_t proc_fault_inject_write(struct file * file,
1177 const char __user * buf, size_t count, loff_t *ppos)
1178 {
1179 struct task_struct *task;
1180 char buffer[PROC_NUMBUF], *end;
1181 int make_it_fail;
1182
1183 if (!capable(CAP_SYS_RESOURCE))
1184 return -EPERM;
1185 memset(buffer, 0, sizeof(buffer));
1186 if (count > sizeof(buffer) - 1)
1187 count = sizeof(buffer) - 1;
1188 if (copy_from_user(buffer, buf, count))
1189 return -EFAULT;
1190 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1191 if (*end)
1192 return -EINVAL;
1193 task = get_proc_task(file->f_dentry->d_inode);
1194 if (!task)
1195 return -ESRCH;
1196 task->make_it_fail = make_it_fail;
1197 put_task_struct(task);
1198
1199 return count;
1200 }
1201
1202 static const struct file_operations proc_fault_inject_operations = {
1203 .read = proc_fault_inject_read,
1204 .write = proc_fault_inject_write,
1205 };
1206 #endif
1207
1208
1209 #ifdef CONFIG_SCHED_DEBUG
1210 /*
1211 * Print out various scheduling related per-task fields:
1212 */
1213 static int sched_show(struct seq_file *m, void *v)
1214 {
1215 struct inode *inode = m->private;
1216 struct task_struct *p;
1217
1218 p = get_proc_task(inode);
1219 if (!p)
1220 return -ESRCH;
1221 proc_sched_show_task(p, m);
1222
1223 put_task_struct(p);
1224
1225 return 0;
1226 }
1227
1228 static ssize_t
1229 sched_write(struct file *file, const char __user *buf,
1230 size_t count, loff_t *offset)
1231 {
1232 struct inode *inode = file->f_path.dentry->d_inode;
1233 struct task_struct *p;
1234
1235 p = get_proc_task(inode);
1236 if (!p)
1237 return -ESRCH;
1238 proc_sched_set_task(p);
1239
1240 put_task_struct(p);
1241
1242 return count;
1243 }
1244
1245 static int sched_open(struct inode *inode, struct file *filp)
1246 {
1247 int ret;
1248
1249 ret = single_open(filp, sched_show, NULL);
1250 if (!ret) {
1251 struct seq_file *m = filp->private_data;
1252
1253 m->private = inode;
1254 }
1255 return ret;
1256 }
1257
1258 static const struct file_operations proc_pid_sched_operations = {
1259 .open = sched_open,
1260 .read = seq_read,
1261 .write = sched_write,
1262 .llseek = seq_lseek,
1263 .release = single_release,
1264 };
1265
1266 #endif
1267
1268 static ssize_t comm_write(struct file *file, const char __user *buf,
1269 size_t count, loff_t *offset)
1270 {
1271 struct inode *inode = file->f_path.dentry->d_inode;
1272 struct task_struct *p;
1273 char buffer[TASK_COMM_LEN];
1274
1275 memset(buffer, 0, sizeof(buffer));
1276 if (count > sizeof(buffer) - 1)
1277 count = sizeof(buffer) - 1;
1278 if (copy_from_user(buffer, buf, count))
1279 return -EFAULT;
1280
1281 p = get_proc_task(inode);
1282 if (!p)
1283 return -ESRCH;
1284
1285 if (same_thread_group(current, p))
1286 set_task_comm(p, buffer);
1287 else
1288 count = -EINVAL;
1289
1290 put_task_struct(p);
1291
1292 return count;
1293 }
1294
1295 static int comm_show(struct seq_file *m, void *v)
1296 {
1297 struct inode *inode = m->private;
1298 struct task_struct *p;
1299
1300 p = get_proc_task(inode);
1301 if (!p)
1302 return -ESRCH;
1303
1304 task_lock(p);
1305 seq_printf(m, "%s\n", p->comm);
1306 task_unlock(p);
1307
1308 put_task_struct(p);
1309
1310 return 0;
1311 }
1312
1313 static int comm_open(struct inode *inode, struct file *filp)
1314 {
1315 int ret;
1316
1317 ret = single_open(filp, comm_show, NULL);
1318 if (!ret) {
1319 struct seq_file *m = filp->private_data;
1320
1321 m->private = inode;
1322 }
1323 return ret;
1324 }
1325
1326 static const struct file_operations proc_pid_set_comm_operations = {
1327 .open = comm_open,
1328 .read = seq_read,
1329 .write = comm_write,
1330 .llseek = seq_lseek,
1331 .release = single_release,
1332 };
1333
1334 /*
1335 * We added or removed a vma mapping the executable. The vmas are only mapped
1336 * during exec and are not mapped with the mmap system call.
1337 * Callers must hold down_write() on the mm's mmap_sem for these
1338 */
1339 void added_exe_file_vma(struct mm_struct *mm)
1340 {
1341 mm->num_exe_file_vmas++;
1342 }
1343
1344 void removed_exe_file_vma(struct mm_struct *mm)
1345 {
1346 mm->num_exe_file_vmas--;
1347 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){
1348 fput(mm->exe_file);
1349 mm->exe_file = NULL;
1350 }
1351
1352 }
1353
1354 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file)
1355 {
1356 if (new_exe_file)
1357 get_file(new_exe_file);
1358 if (mm->exe_file)
1359 fput(mm->exe_file);
1360 mm->exe_file = new_exe_file;
1361 mm->num_exe_file_vmas = 0;
1362 }
1363
1364 struct file *get_mm_exe_file(struct mm_struct *mm)
1365 {
1366 struct file *exe_file;
1367
1368 /* We need mmap_sem to protect against races with removal of
1369 * VM_EXECUTABLE vmas */
1370 down_read(&mm->mmap_sem);
1371 exe_file = mm->exe_file;
1372 if (exe_file)
1373 get_file(exe_file);
1374 up_read(&mm->mmap_sem);
1375 return exe_file;
1376 }
1377
1378 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm)
1379 {
1380 /* It's safe to write the exe_file pointer without exe_file_lock because
1381 * this is called during fork when the task is not yet in /proc */
1382 newmm->exe_file = get_mm_exe_file(oldmm);
1383 }
1384
1385 static int proc_exe_link(struct inode *inode, struct path *exe_path)
1386 {
1387 struct task_struct *task;
1388 struct mm_struct *mm;
1389 struct file *exe_file;
1390
1391 task = get_proc_task(inode);
1392 if (!task)
1393 return -ENOENT;
1394 mm = get_task_mm(task);
1395 put_task_struct(task);
1396 if (!mm)
1397 return -ENOENT;
1398 exe_file = get_mm_exe_file(mm);
1399 mmput(mm);
1400 if (exe_file) {
1401 *exe_path = exe_file->f_path;
1402 path_get(&exe_file->f_path);
1403 fput(exe_file);
1404 return 0;
1405 } else
1406 return -ENOENT;
1407 }
1408
1409 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1410 {
1411 struct inode *inode = dentry->d_inode;
1412 int error = -EACCES;
1413
1414 /* We don't need a base pointer in the /proc filesystem */
1415 path_put(&nd->path);
1416
1417 /* Are we allowed to snoop on the tasks file descriptors? */
1418 if (!proc_fd_access_allowed(inode))
1419 goto out;
1420
1421 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
1422 out:
1423 return ERR_PTR(error);
1424 }
1425
1426 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1427 {
1428 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1429 char *pathname;
1430 int len;
1431
1432 if (!tmp)
1433 return -ENOMEM;
1434
1435 pathname = d_path(path, tmp, PAGE_SIZE);
1436 len = PTR_ERR(pathname);
1437 if (IS_ERR(pathname))
1438 goto out;
1439 len = tmp + PAGE_SIZE - 1 - pathname;
1440
1441 if (len > buflen)
1442 len = buflen;
1443 if (copy_to_user(buffer, pathname, len))
1444 len = -EFAULT;
1445 out:
1446 free_page((unsigned long)tmp);
1447 return len;
1448 }
1449
1450 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1451 {
1452 int error = -EACCES;
1453 struct inode *inode = dentry->d_inode;
1454 struct path path;
1455
1456 /* Are we allowed to snoop on the tasks file descriptors? */
1457 if (!proc_fd_access_allowed(inode))
1458 goto out;
1459
1460 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1461 if (error)
1462 goto out;
1463
1464 error = do_proc_readlink(&path, buffer, buflen);
1465 path_put(&path);
1466 out:
1467 return error;
1468 }
1469
1470 static const struct inode_operations proc_pid_link_inode_operations = {
1471 .readlink = proc_pid_readlink,
1472 .follow_link = proc_pid_follow_link,
1473 .setattr = proc_setattr,
1474 };
1475
1476
1477 /* building an inode */
1478
1479 static int task_dumpable(struct task_struct *task)
1480 {
1481 int dumpable = 0;
1482 struct mm_struct *mm;
1483
1484 task_lock(task);
1485 mm = task->mm;
1486 if (mm)
1487 dumpable = get_dumpable(mm);
1488 task_unlock(task);
1489 if(dumpable == 1)
1490 return 1;
1491 return 0;
1492 }
1493
1494
1495 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1496 {
1497 struct inode * inode;
1498 struct proc_inode *ei;
1499 const struct cred *cred;
1500
1501 /* We need a new inode */
1502
1503 inode = new_inode(sb);
1504 if (!inode)
1505 goto out;
1506
1507 /* Common stuff */
1508 ei = PROC_I(inode);
1509 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1510 inode->i_op = &proc_def_inode_operations;
1511
1512 /*
1513 * grab the reference to task.
1514 */
1515 ei->pid = get_task_pid(task, PIDTYPE_PID);
1516 if (!ei->pid)
1517 goto out_unlock;
1518
1519 if (task_dumpable(task)) {
1520 rcu_read_lock();
1521 cred = __task_cred(task);
1522 inode->i_uid = cred->euid;
1523 inode->i_gid = cred->egid;
1524 rcu_read_unlock();
1525 }
1526 security_task_to_inode(task, inode);
1527
1528 out:
1529 return inode;
1530
1531 out_unlock:
1532 iput(inode);
1533 return NULL;
1534 }
1535
1536 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1537 {
1538 struct inode *inode = dentry->d_inode;
1539 struct task_struct *task;
1540 const struct cred *cred;
1541
1542 generic_fillattr(inode, stat);
1543
1544 rcu_read_lock();
1545 stat->uid = 0;
1546 stat->gid = 0;
1547 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1548 if (task) {
1549 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1550 task_dumpable(task)) {
1551 cred = __task_cred(task);
1552 stat->uid = cred->euid;
1553 stat->gid = cred->egid;
1554 }
1555 }
1556 rcu_read_unlock();
1557 return 0;
1558 }
1559
1560 /* dentry stuff */
1561
1562 /*
1563 * Exceptional case: normally we are not allowed to unhash a busy
1564 * directory. In this case, however, we can do it - no aliasing problems
1565 * due to the way we treat inodes.
1566 *
1567 * Rewrite the inode's ownerships here because the owning task may have
1568 * performed a setuid(), etc.
1569 *
1570 * Before the /proc/pid/status file was created the only way to read
1571 * the effective uid of a /process was to stat /proc/pid. Reading
1572 * /proc/pid/status is slow enough that procps and other packages
1573 * kept stating /proc/pid. To keep the rules in /proc simple I have
1574 * made this apply to all per process world readable and executable
1575 * directories.
1576 */
1577 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1578 {
1579 struct inode *inode = dentry->d_inode;
1580 struct task_struct *task = get_proc_task(inode);
1581 const struct cred *cred;
1582
1583 if (task) {
1584 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1585 task_dumpable(task)) {
1586 rcu_read_lock();
1587 cred = __task_cred(task);
1588 inode->i_uid = cred->euid;
1589 inode->i_gid = cred->egid;
1590 rcu_read_unlock();
1591 } else {
1592 inode->i_uid = 0;
1593 inode->i_gid = 0;
1594 }
1595 inode->i_mode &= ~(S_ISUID | S_ISGID);
1596 security_task_to_inode(task, inode);
1597 put_task_struct(task);
1598 return 1;
1599 }
1600 d_drop(dentry);
1601 return 0;
1602 }
1603
1604 static int pid_delete_dentry(struct dentry * dentry)
1605 {
1606 /* Is the task we represent dead?
1607 * If so, then don't put the dentry on the lru list,
1608 * kill it immediately.
1609 */
1610 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1611 }
1612
1613 static const struct dentry_operations pid_dentry_operations =
1614 {
1615 .d_revalidate = pid_revalidate,
1616 .d_delete = pid_delete_dentry,
1617 };
1618
1619 /* Lookups */
1620
1621 typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
1622 struct task_struct *, const void *);
1623
1624 /*
1625 * Fill a directory entry.
1626 *
1627 * If possible create the dcache entry and derive our inode number and
1628 * file type from dcache entry.
1629 *
1630 * Since all of the proc inode numbers are dynamically generated, the inode
1631 * numbers do not exist until the inode is cache. This means creating the
1632 * the dcache entry in readdir is necessary to keep the inode numbers
1633 * reported by readdir in sync with the inode numbers reported
1634 * by stat.
1635 */
1636 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1637 char *name, int len,
1638 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1639 {
1640 struct dentry *child, *dir = filp->f_path.dentry;
1641 struct inode *inode;
1642 struct qstr qname;
1643 ino_t ino = 0;
1644 unsigned type = DT_UNKNOWN;
1645
1646 qname.name = name;
1647 qname.len = len;
1648 qname.hash = full_name_hash(name, len);
1649
1650 child = d_lookup(dir, &qname);
1651 if (!child) {
1652 struct dentry *new;
1653 new = d_alloc(dir, &qname);
1654 if (new) {
1655 child = instantiate(dir->d_inode, new, task, ptr);
1656 if (child)
1657 dput(new);
1658 else
1659 child = new;
1660 }
1661 }
1662 if (!child || IS_ERR(child) || !child->d_inode)
1663 goto end_instantiate;
1664 inode = child->d_inode;
1665 if (inode) {
1666 ino = inode->i_ino;
1667 type = inode->i_mode >> 12;
1668 }
1669 dput(child);
1670 end_instantiate:
1671 if (!ino)
1672 ino = find_inode_number(dir, &qname);
1673 if (!ino)
1674 ino = 1;
1675 return filldir(dirent, name, len, filp->f_pos, ino, type);
1676 }
1677
1678 static unsigned name_to_int(struct dentry *dentry)
1679 {
1680 const char *name = dentry->d_name.name;
1681 int len = dentry->d_name.len;
1682 unsigned n = 0;
1683
1684 if (len > 1 && *name == '0')
1685 goto out;
1686 while (len-- > 0) {
1687 unsigned c = *name++ - '0';
1688 if (c > 9)
1689 goto out;
1690 if (n >= (~0U-9)/10)
1691 goto out;
1692 n *= 10;
1693 n += c;
1694 }
1695 return n;
1696 out:
1697 return ~0U;
1698 }
1699
1700 #define PROC_FDINFO_MAX 64
1701
1702 static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1703 {
1704 struct task_struct *task = get_proc_task(inode);
1705 struct files_struct *files = NULL;
1706 struct file *file;
1707 int fd = proc_fd(inode);
1708
1709 if (task) {
1710 files = get_files_struct(task);
1711 put_task_struct(task);
1712 }
1713 if (files) {
1714 /*
1715 * We are not taking a ref to the file structure, so we must
1716 * hold ->file_lock.
1717 */
1718 spin_lock(&files->file_lock);
1719 file = fcheck_files(files, fd);
1720 if (file) {
1721 if (path) {
1722 *path = file->f_path;
1723 path_get(&file->f_path);
1724 }
1725 if (info)
1726 snprintf(info, PROC_FDINFO_MAX,
1727 "pos:\t%lli\n"
1728 "flags:\t0%o\n",
1729 (long long) file->f_pos,
1730 file->f_flags);
1731 spin_unlock(&files->file_lock);
1732 put_files_struct(files);
1733 return 0;
1734 }
1735 spin_unlock(&files->file_lock);
1736 put_files_struct(files);
1737 }
1738 return -ENOENT;
1739 }
1740
1741 static int proc_fd_link(struct inode *inode, struct path *path)
1742 {
1743 return proc_fd_info(inode, path, NULL);
1744 }
1745
1746 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1747 {
1748 struct inode *inode = dentry->d_inode;
1749 struct task_struct *task = get_proc_task(inode);
1750 int fd = proc_fd(inode);
1751 struct files_struct *files;
1752 const struct cred *cred;
1753
1754 if (task) {
1755 files = get_files_struct(task);
1756 if (files) {
1757 rcu_read_lock();
1758 if (fcheck_files(files, fd)) {
1759 rcu_read_unlock();
1760 put_files_struct(files);
1761 if (task_dumpable(task)) {
1762 rcu_read_lock();
1763 cred = __task_cred(task);
1764 inode->i_uid = cred->euid;
1765 inode->i_gid = cred->egid;
1766 rcu_read_unlock();
1767 } else {
1768 inode->i_uid = 0;
1769 inode->i_gid = 0;
1770 }
1771 inode->i_mode &= ~(S_ISUID | S_ISGID);
1772 security_task_to_inode(task, inode);
1773 put_task_struct(task);
1774 return 1;
1775 }
1776 rcu_read_unlock();
1777 put_files_struct(files);
1778 }
1779 put_task_struct(task);
1780 }
1781 d_drop(dentry);
1782 return 0;
1783 }
1784
1785 static const struct dentry_operations tid_fd_dentry_operations =
1786 {
1787 .d_revalidate = tid_fd_revalidate,
1788 .d_delete = pid_delete_dentry,
1789 };
1790
1791 static struct dentry *proc_fd_instantiate(struct inode *dir,
1792 struct dentry *dentry, struct task_struct *task, const void *ptr)
1793 {
1794 unsigned fd = *(const unsigned *)ptr;
1795 struct file *file;
1796 struct files_struct *files;
1797 struct inode *inode;
1798 struct proc_inode *ei;
1799 struct dentry *error = ERR_PTR(-ENOENT);
1800
1801 inode = proc_pid_make_inode(dir->i_sb, task);
1802 if (!inode)
1803 goto out;
1804 ei = PROC_I(inode);
1805 ei->fd = fd;
1806 files = get_files_struct(task);
1807 if (!files)
1808 goto out_iput;
1809 inode->i_mode = S_IFLNK;
1810
1811 /*
1812 * We are not taking a ref to the file structure, so we must
1813 * hold ->file_lock.
1814 */
1815 spin_lock(&files->file_lock);
1816 file = fcheck_files(files, fd);
1817 if (!file)
1818 goto out_unlock;
1819 if (file->f_mode & FMODE_READ)
1820 inode->i_mode |= S_IRUSR | S_IXUSR;
1821 if (file->f_mode & FMODE_WRITE)
1822 inode->i_mode |= S_IWUSR | S_IXUSR;
1823 spin_unlock(&files->file_lock);
1824 put_files_struct(files);
1825
1826 inode->i_op = &proc_pid_link_inode_operations;
1827 inode->i_size = 64;
1828 ei->op.proc_get_link = proc_fd_link;
1829 dentry->d_op = &tid_fd_dentry_operations;
1830 d_add(dentry, inode);
1831 /* Close the race of the process dying before we return the dentry */
1832 if (tid_fd_revalidate(dentry, NULL))
1833 error = NULL;
1834
1835 out:
1836 return error;
1837 out_unlock:
1838 spin_unlock(&files->file_lock);
1839 put_files_struct(files);
1840 out_iput:
1841 iput(inode);
1842 goto out;
1843 }
1844
1845 static struct dentry *proc_lookupfd_common(struct inode *dir,
1846 struct dentry *dentry,
1847 instantiate_t instantiate)
1848 {
1849 struct task_struct *task = get_proc_task(dir);
1850 unsigned fd = name_to_int(dentry);
1851 struct dentry *result = ERR_PTR(-ENOENT);
1852
1853 if (!task)
1854 goto out_no_task;
1855 if (fd == ~0U)
1856 goto out;
1857
1858 result = instantiate(dir, dentry, task, &fd);
1859 out:
1860 put_task_struct(task);
1861 out_no_task:
1862 return result;
1863 }
1864
1865 static int proc_readfd_common(struct file * filp, void * dirent,
1866 filldir_t filldir, instantiate_t instantiate)
1867 {
1868 struct dentry *dentry = filp->f_path.dentry;
1869 struct inode *inode = dentry->d_inode;
1870 struct task_struct *p = get_proc_task(inode);
1871 unsigned int fd, ino;
1872 int retval;
1873 struct files_struct * files;
1874
1875 retval = -ENOENT;
1876 if (!p)
1877 goto out_no_task;
1878 retval = 0;
1879
1880 fd = filp->f_pos;
1881 switch (fd) {
1882 case 0:
1883 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1884 goto out;
1885 filp->f_pos++;
1886 case 1:
1887 ino = parent_ino(dentry);
1888 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1889 goto out;
1890 filp->f_pos++;
1891 default:
1892 files = get_files_struct(p);
1893 if (!files)
1894 goto out;
1895 rcu_read_lock();
1896 for (fd = filp->f_pos-2;
1897 fd < files_fdtable(files)->max_fds;
1898 fd++, filp->f_pos++) {
1899 char name[PROC_NUMBUF];
1900 int len;
1901
1902 if (!fcheck_files(files, fd))
1903 continue;
1904 rcu_read_unlock();
1905
1906 len = snprintf(name, sizeof(name), "%d", fd);
1907 if (proc_fill_cache(filp, dirent, filldir,
1908 name, len, instantiate,
1909 p, &fd) < 0) {
1910 rcu_read_lock();
1911 break;
1912 }
1913 rcu_read_lock();
1914 }
1915 rcu_read_unlock();
1916 put_files_struct(files);
1917 }
1918 out:
1919 put_task_struct(p);
1920 out_no_task:
1921 return retval;
1922 }
1923
1924 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
1925 struct nameidata *nd)
1926 {
1927 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
1928 }
1929
1930 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
1931 {
1932 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
1933 }
1934
1935 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
1936 size_t len, loff_t *ppos)
1937 {
1938 char tmp[PROC_FDINFO_MAX];
1939 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
1940 if (!err)
1941 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
1942 return err;
1943 }
1944
1945 static const struct file_operations proc_fdinfo_file_operations = {
1946 .open = nonseekable_open,
1947 .read = proc_fdinfo_read,
1948 };
1949
1950 static const struct file_operations proc_fd_operations = {
1951 .read = generic_read_dir,
1952 .readdir = proc_readfd,
1953 };
1954
1955 /*
1956 * /proc/pid/fd needs a special permission handler so that a process can still
1957 * access /proc/self/fd after it has executed a setuid().
1958 */
1959 static int proc_fd_permission(struct inode *inode, int mask)
1960 {
1961 int rv;
1962
1963 rv = generic_permission(inode, mask, NULL);
1964 if (rv == 0)
1965 return 0;
1966 if (task_pid(current) == proc_pid(inode))
1967 rv = 0;
1968 return rv;
1969 }
1970
1971 /*
1972 * proc directories can do almost nothing..
1973 */
1974 static const struct inode_operations proc_fd_inode_operations = {
1975 .lookup = proc_lookupfd,
1976 .permission = proc_fd_permission,
1977 .setattr = proc_setattr,
1978 };
1979
1980 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
1981 struct dentry *dentry, struct task_struct *task, const void *ptr)
1982 {
1983 unsigned fd = *(unsigned *)ptr;
1984 struct inode *inode;
1985 struct proc_inode *ei;
1986 struct dentry *error = ERR_PTR(-ENOENT);
1987
1988 inode = proc_pid_make_inode(dir->i_sb, task);
1989 if (!inode)
1990 goto out;
1991 ei = PROC_I(inode);
1992 ei->fd = fd;
1993 inode->i_mode = S_IFREG | S_IRUSR;
1994 inode->i_fop = &proc_fdinfo_file_operations;
1995 dentry->d_op = &tid_fd_dentry_operations;
1996 d_add(dentry, inode);
1997 /* Close the race of the process dying before we return the dentry */
1998 if (tid_fd_revalidate(dentry, NULL))
1999 error = NULL;
2000
2001 out:
2002 return error;
2003 }
2004
2005 static struct dentry *proc_lookupfdinfo(struct inode *dir,
2006 struct dentry *dentry,
2007 struct nameidata *nd)
2008 {
2009 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2010 }
2011
2012 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2013 {
2014 return proc_readfd_common(filp, dirent, filldir,
2015 proc_fdinfo_instantiate);
2016 }
2017
2018 static const struct file_operations proc_fdinfo_operations = {
2019 .read = generic_read_dir,
2020 .readdir = proc_readfdinfo,
2021 };
2022
2023 /*
2024 * proc directories can do almost nothing..
2025 */
2026 static const struct inode_operations proc_fdinfo_inode_operations = {
2027 .lookup = proc_lookupfdinfo,
2028 .setattr = proc_setattr,
2029 };
2030
2031
2032 static struct dentry *proc_pident_instantiate(struct inode *dir,
2033 struct dentry *dentry, struct task_struct *task, const void *ptr)
2034 {
2035 const struct pid_entry *p = ptr;
2036 struct inode *inode;
2037 struct proc_inode *ei;
2038 struct dentry *error = ERR_PTR(-ENOENT);
2039
2040 inode = proc_pid_make_inode(dir->i_sb, task);
2041 if (!inode)
2042 goto out;
2043
2044 ei = PROC_I(inode);
2045 inode->i_mode = p->mode;
2046 if (S_ISDIR(inode->i_mode))
2047 inode->i_nlink = 2; /* Use getattr to fix if necessary */
2048 if (p->iop)
2049 inode->i_op = p->iop;
2050 if (p->fop)
2051 inode->i_fop = p->fop;
2052 ei->op = p->op;
2053 dentry->d_op = &pid_dentry_operations;
2054 d_add(dentry, inode);
2055 /* Close the race of the process dying before we return the dentry */
2056 if (pid_revalidate(dentry, NULL))
2057 error = NULL;
2058 out:
2059 return error;
2060 }
2061
2062 static struct dentry *proc_pident_lookup(struct inode *dir,
2063 struct dentry *dentry,
2064 const struct pid_entry *ents,
2065 unsigned int nents)
2066 {
2067 struct dentry *error;
2068 struct task_struct *task = get_proc_task(dir);
2069 const struct pid_entry *p, *last;
2070
2071 error = ERR_PTR(-ENOENT);
2072
2073 if (!task)
2074 goto out_no_task;
2075
2076 /*
2077 * Yes, it does not scale. And it should not. Don't add
2078 * new entries into /proc/<tgid>/ without very good reasons.
2079 */
2080 last = &ents[nents - 1];
2081 for (p = ents; p <= last; p++) {
2082 if (p->len != dentry->d_name.len)
2083 continue;
2084 if (!memcmp(dentry->d_name.name, p->name, p->len))
2085 break;
2086 }
2087 if (p > last)
2088 goto out;
2089
2090 error = proc_pident_instantiate(dir, dentry, task, p);
2091 out:
2092 put_task_struct(task);
2093 out_no_task:
2094 return error;
2095 }
2096
2097 static int proc_pident_fill_cache(struct file *filp, void *dirent,
2098 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2099 {
2100 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2101 proc_pident_instantiate, task, p);
2102 }
2103
2104 static int proc_pident_readdir(struct file *filp,
2105 void *dirent, filldir_t filldir,
2106 const struct pid_entry *ents, unsigned int nents)
2107 {
2108 int i;
2109 struct dentry *dentry = filp->f_path.dentry;
2110 struct inode *inode = dentry->d_inode;
2111 struct task_struct *task = get_proc_task(inode);
2112 const struct pid_entry *p, *last;
2113 ino_t ino;
2114 int ret;
2115
2116 ret = -ENOENT;
2117 if (!task)
2118 goto out_no_task;
2119
2120 ret = 0;
2121 i = filp->f_pos;
2122 switch (i) {
2123 case 0:
2124 ino = inode->i_ino;
2125 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2126 goto out;
2127 i++;
2128 filp->f_pos++;
2129 /* fall through */
2130 case 1:
2131 ino = parent_ino(dentry);
2132 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2133 goto out;
2134 i++;
2135 filp->f_pos++;
2136 /* fall through */
2137 default:
2138 i -= 2;
2139 if (i >= nents) {
2140 ret = 1;
2141 goto out;
2142 }
2143 p = ents + i;
2144 last = &ents[nents - 1];
2145 while (p <= last) {
2146 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2147 goto out;
2148 filp->f_pos++;
2149 p++;
2150 }
2151 }
2152
2153 ret = 1;
2154 out:
2155 put_task_struct(task);
2156 out_no_task:
2157 return ret;
2158 }
2159
2160 #ifdef CONFIG_SECURITY
2161 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2162 size_t count, loff_t *ppos)
2163 {
2164 struct inode * inode = file->f_path.dentry->d_inode;
2165 char *p = NULL;
2166 ssize_t length;
2167 struct task_struct *task = get_proc_task(inode);
2168
2169 if (!task)
2170 return -ESRCH;
2171
2172 length = security_getprocattr(task,
2173 (char*)file->f_path.dentry->d_name.name,
2174 &p);
2175 put_task_struct(task);
2176 if (length > 0)
2177 length = simple_read_from_buffer(buf, count, ppos, p, length);
2178 kfree(p);
2179 return length;
2180 }
2181
2182 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2183 size_t count, loff_t *ppos)
2184 {
2185 struct inode * inode = file->f_path.dentry->d_inode;
2186 char *page;
2187 ssize_t length;
2188 struct task_struct *task = get_proc_task(inode);
2189
2190 length = -ESRCH;
2191 if (!task)
2192 goto out_no_task;
2193 if (count > PAGE_SIZE)
2194 count = PAGE_SIZE;
2195
2196 /* No partial writes. */
2197 length = -EINVAL;
2198 if (*ppos != 0)
2199 goto out;
2200
2201 length = -ENOMEM;
2202 page = (char*)__get_free_page(GFP_TEMPORARY);
2203 if (!page)
2204 goto out;
2205
2206 length = -EFAULT;
2207 if (copy_from_user(page, buf, count))
2208 goto out_free;
2209
2210 /* Guard against adverse ptrace interaction */
2211 length = mutex_lock_interruptible(&task->cred_guard_mutex);
2212 if (length < 0)
2213 goto out_free;
2214
2215 length = security_setprocattr(task,
2216 (char*)file->f_path.dentry->d_name.name,
2217 (void*)page, count);
2218 mutex_unlock(&task->cred_guard_mutex);
2219 out_free:
2220 free_page((unsigned long) page);
2221 out:
2222 put_task_struct(task);
2223 out_no_task:
2224 return length;
2225 }
2226
2227 static const struct file_operations proc_pid_attr_operations = {
2228 .read = proc_pid_attr_read,
2229 .write = proc_pid_attr_write,
2230 };
2231
2232 static const struct pid_entry attr_dir_stuff[] = {
2233 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2234 REG("prev", S_IRUGO, proc_pid_attr_operations),
2235 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2236 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2237 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2238 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2239 };
2240
2241 static int proc_attr_dir_readdir(struct file * filp,
2242 void * dirent, filldir_t filldir)
2243 {
2244 return proc_pident_readdir(filp,dirent,filldir,
2245 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2246 }
2247
2248 static const struct file_operations proc_attr_dir_operations = {
2249 .read = generic_read_dir,
2250 .readdir = proc_attr_dir_readdir,
2251 };
2252
2253 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2254 struct dentry *dentry, struct nameidata *nd)
2255 {
2256 return proc_pident_lookup(dir, dentry,
2257 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2258 }
2259
2260 static const struct inode_operations proc_attr_dir_inode_operations = {
2261 .lookup = proc_attr_dir_lookup,
2262 .getattr = pid_getattr,
2263 .setattr = proc_setattr,
2264 };
2265
2266 #endif
2267
2268 #ifdef CONFIG_ELF_CORE
2269 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2270 size_t count, loff_t *ppos)
2271 {
2272 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2273 struct mm_struct *mm;
2274 char buffer[PROC_NUMBUF];
2275 size_t len;
2276 int ret;
2277
2278 if (!task)
2279 return -ESRCH;
2280
2281 ret = 0;
2282 mm = get_task_mm(task);
2283 if (mm) {
2284 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2285 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2286 MMF_DUMP_FILTER_SHIFT));
2287 mmput(mm);
2288 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2289 }
2290
2291 put_task_struct(task);
2292
2293 return ret;
2294 }
2295
2296 static ssize_t proc_coredump_filter_write(struct file *file,
2297 const char __user *buf,
2298 size_t count,
2299 loff_t *ppos)
2300 {
2301 struct task_struct *task;
2302 struct mm_struct *mm;
2303 char buffer[PROC_NUMBUF], *end;
2304 unsigned int val;
2305 int ret;
2306 int i;
2307 unsigned long mask;
2308
2309 ret = -EFAULT;
2310 memset(buffer, 0, sizeof(buffer));
2311 if (count > sizeof(buffer) - 1)
2312 count = sizeof(buffer) - 1;
2313 if (copy_from_user(buffer, buf, count))
2314 goto out_no_task;
2315
2316 ret = -EINVAL;
2317 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2318 if (*end == '\n')
2319 end++;
2320 if (end - buffer == 0)
2321 goto out_no_task;
2322
2323 ret = -ESRCH;
2324 task = get_proc_task(file->f_dentry->d_inode);
2325 if (!task)
2326 goto out_no_task;
2327
2328 ret = end - buffer;
2329 mm = get_task_mm(task);
2330 if (!mm)
2331 goto out_no_mm;
2332
2333 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2334 if (val & mask)
2335 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2336 else
2337 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2338 }
2339
2340 mmput(mm);
2341 out_no_mm:
2342 put_task_struct(task);
2343 out_no_task:
2344 return ret;
2345 }
2346
2347 static const struct file_operations proc_coredump_filter_operations = {
2348 .read = proc_coredump_filter_read,
2349 .write = proc_coredump_filter_write,
2350 };
2351 #endif
2352
2353 /*
2354 * /proc/self:
2355 */
2356 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2357 int buflen)
2358 {
2359 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2360 pid_t tgid = task_tgid_nr_ns(current, ns);
2361 char tmp[PROC_NUMBUF];
2362 if (!tgid)
2363 return -ENOENT;
2364 sprintf(tmp, "%d", tgid);
2365 return vfs_readlink(dentry,buffer,buflen,tmp);
2366 }
2367
2368 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2369 {
2370 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2371 pid_t tgid = task_tgid_nr_ns(current, ns);
2372 char tmp[PROC_NUMBUF];
2373 if (!tgid)
2374 return ERR_PTR(-ENOENT);
2375 sprintf(tmp, "%d", task_tgid_nr_ns(current, ns));
2376 return ERR_PTR(vfs_follow_link(nd,tmp));
2377 }
2378
2379 static const struct inode_operations proc_self_inode_operations = {
2380 .readlink = proc_self_readlink,
2381 .follow_link = proc_self_follow_link,
2382 };
2383
2384 /*
2385 * proc base
2386 *
2387 * These are the directory entries in the root directory of /proc
2388 * that properly belong to the /proc filesystem, as they describe
2389 * describe something that is process related.
2390 */
2391 static const struct pid_entry proc_base_stuff[] = {
2392 NOD("self", S_IFLNK|S_IRWXUGO,
2393 &proc_self_inode_operations, NULL, {}),
2394 };
2395
2396 /*
2397 * Exceptional case: normally we are not allowed to unhash a busy
2398 * directory. In this case, however, we can do it - no aliasing problems
2399 * due to the way we treat inodes.
2400 */
2401 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
2402 {
2403 struct inode *inode = dentry->d_inode;
2404 struct task_struct *task = get_proc_task(inode);
2405 if (task) {
2406 put_task_struct(task);
2407 return 1;
2408 }
2409 d_drop(dentry);
2410 return 0;
2411 }
2412
2413 static const struct dentry_operations proc_base_dentry_operations =
2414 {
2415 .d_revalidate = proc_base_revalidate,
2416 .d_delete = pid_delete_dentry,
2417 };
2418
2419 static struct dentry *proc_base_instantiate(struct inode *dir,
2420 struct dentry *dentry, struct task_struct *task, const void *ptr)
2421 {
2422 const struct pid_entry *p = ptr;
2423 struct inode *inode;
2424 struct proc_inode *ei;
2425 struct dentry *error = ERR_PTR(-EINVAL);
2426
2427 /* Allocate the inode */
2428 error = ERR_PTR(-ENOMEM);
2429 inode = new_inode(dir->i_sb);
2430 if (!inode)
2431 goto out;
2432
2433 /* Initialize the inode */
2434 ei = PROC_I(inode);
2435 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2436
2437 /*
2438 * grab the reference to the task.
2439 */
2440 ei->pid = get_task_pid(task, PIDTYPE_PID);
2441 if (!ei->pid)
2442 goto out_iput;
2443
2444 inode->i_mode = p->mode;
2445 if (S_ISDIR(inode->i_mode))
2446 inode->i_nlink = 2;
2447 if (S_ISLNK(inode->i_mode))
2448 inode->i_size = 64;
2449 if (p->iop)
2450 inode->i_op = p->iop;
2451 if (p->fop)
2452 inode->i_fop = p->fop;
2453 ei->op = p->op;
2454 dentry->d_op = &proc_base_dentry_operations;
2455 d_add(dentry, inode);
2456 error = NULL;
2457 out:
2458 return error;
2459 out_iput:
2460 iput(inode);
2461 goto out;
2462 }
2463
2464 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2465 {
2466 struct dentry *error;
2467 struct task_struct *task = get_proc_task(dir);
2468 const struct pid_entry *p, *last;
2469
2470 error = ERR_PTR(-ENOENT);
2471
2472 if (!task)
2473 goto out_no_task;
2474
2475 /* Lookup the directory entry */
2476 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2477 for (p = proc_base_stuff; p <= last; p++) {
2478 if (p->len != dentry->d_name.len)
2479 continue;
2480 if (!memcmp(dentry->d_name.name, p->name, p->len))
2481 break;
2482 }
2483 if (p > last)
2484 goto out;
2485
2486 error = proc_base_instantiate(dir, dentry, task, p);
2487
2488 out:
2489 put_task_struct(task);
2490 out_no_task:
2491 return error;
2492 }
2493
2494 static int proc_base_fill_cache(struct file *filp, void *dirent,
2495 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2496 {
2497 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2498 proc_base_instantiate, task, p);
2499 }
2500
2501 #ifdef CONFIG_TASK_IO_ACCOUNTING
2502 static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2503 {
2504 struct task_io_accounting acct = task->ioac;
2505 unsigned long flags;
2506
2507 if (whole && lock_task_sighand(task, &flags)) {
2508 struct task_struct *t = task;
2509
2510 task_io_accounting_add(&acct, &task->signal->ioac);
2511 while_each_thread(task, t)
2512 task_io_accounting_add(&acct, &t->ioac);
2513
2514 unlock_task_sighand(task, &flags);
2515 }
2516 return sprintf(buffer,
2517 "rchar: %llu\n"
2518 "wchar: %llu\n"
2519 "syscr: %llu\n"
2520 "syscw: %llu\n"
2521 "read_bytes: %llu\n"
2522 "write_bytes: %llu\n"
2523 "cancelled_write_bytes: %llu\n",
2524 (unsigned long long)acct.rchar,
2525 (unsigned long long)acct.wchar,
2526 (unsigned long long)acct.syscr,
2527 (unsigned long long)acct.syscw,
2528 (unsigned long long)acct.read_bytes,
2529 (unsigned long long)acct.write_bytes,
2530 (unsigned long long)acct.cancelled_write_bytes);
2531 }
2532
2533 static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2534 {
2535 return do_io_accounting(task, buffer, 0);
2536 }
2537
2538 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2539 {
2540 return do_io_accounting(task, buffer, 1);
2541 }
2542 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2543
2544 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2545 struct pid *pid, struct task_struct *task)
2546 {
2547 seq_printf(m, "%08x\n", task->personality);
2548 return 0;
2549 }
2550
2551 /*
2552 * Thread groups
2553 */
2554 static const struct file_operations proc_task_operations;
2555 static const struct inode_operations proc_task_inode_operations;
2556
2557 static const struct pid_entry tgid_base_stuff[] = {
2558 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2559 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2560 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2561 #ifdef CONFIG_NET
2562 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2563 #endif
2564 REG("environ", S_IRUSR, proc_environ_operations),
2565 INF("auxv", S_IRUSR, proc_pid_auxv),
2566 ONE("status", S_IRUGO, proc_pid_status),
2567 ONE("personality", S_IRUSR, proc_pid_personality),
2568 INF("limits", S_IRUSR, proc_pid_limits),
2569 #ifdef CONFIG_SCHED_DEBUG
2570 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2571 #endif
2572 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2573 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2574 INF("syscall", S_IRUSR, proc_pid_syscall),
2575 #endif
2576 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2577 ONE("stat", S_IRUGO, proc_tgid_stat),
2578 ONE("statm", S_IRUGO, proc_pid_statm),
2579 REG("maps", S_IRUGO, proc_maps_operations),
2580 #ifdef CONFIG_NUMA
2581 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
2582 #endif
2583 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2584 LNK("cwd", proc_cwd_link),
2585 LNK("root", proc_root_link),
2586 LNK("exe", proc_exe_link),
2587 REG("mounts", S_IRUGO, proc_mounts_operations),
2588 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2589 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2590 #ifdef CONFIG_PROC_PAGE_MONITOR
2591 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2592 REG("smaps", S_IRUGO, proc_smaps_operations),
2593 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2594 #endif
2595 #ifdef CONFIG_SECURITY
2596 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2597 #endif
2598 #ifdef CONFIG_KALLSYMS
2599 INF("wchan", S_IRUGO, proc_pid_wchan),
2600 #endif
2601 #ifdef CONFIG_STACKTRACE
2602 ONE("stack", S_IRUSR, proc_pid_stack),
2603 #endif
2604 #ifdef CONFIG_SCHEDSTATS
2605 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2606 #endif
2607 #ifdef CONFIG_LATENCYTOP
2608 REG("latency", S_IRUGO, proc_lstats_operations),
2609 #endif
2610 #ifdef CONFIG_PROC_PID_CPUSET
2611 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2612 #endif
2613 #ifdef CONFIG_CGROUPS
2614 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2615 #endif
2616 INF("oom_score", S_IRUGO, proc_oom_score),
2617 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2618 #ifdef CONFIG_AUDITSYSCALL
2619 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2620 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2621 #endif
2622 #ifdef CONFIG_FAULT_INJECTION
2623 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2624 #endif
2625 #ifdef CONFIG_ELF_CORE
2626 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2627 #endif
2628 #ifdef CONFIG_TASK_IO_ACCOUNTING
2629 INF("io", S_IRUGO, proc_tgid_io_accounting),
2630 #endif
2631 };
2632
2633 static int proc_tgid_base_readdir(struct file * filp,
2634 void * dirent, filldir_t filldir)
2635 {
2636 return proc_pident_readdir(filp,dirent,filldir,
2637 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2638 }
2639
2640 static const struct file_operations proc_tgid_base_operations = {
2641 .read = generic_read_dir,
2642 .readdir = proc_tgid_base_readdir,
2643 };
2644
2645 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2646 return proc_pident_lookup(dir, dentry,
2647 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2648 }
2649
2650 static const struct inode_operations proc_tgid_base_inode_operations = {
2651 .lookup = proc_tgid_base_lookup,
2652 .getattr = pid_getattr,
2653 .setattr = proc_setattr,
2654 };
2655
2656 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2657 {
2658 struct dentry *dentry, *leader, *dir;
2659 char buf[PROC_NUMBUF];
2660 struct qstr name;
2661
2662 name.name = buf;
2663 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2664 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2665 if (dentry) {
2666 shrink_dcache_parent(dentry);
2667 d_drop(dentry);
2668 dput(dentry);
2669 }
2670
2671 name.name = buf;
2672 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2673 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2674 if (!leader)
2675 goto out;
2676
2677 name.name = "task";
2678 name.len = strlen(name.name);
2679 dir = d_hash_and_lookup(leader, &name);
2680 if (!dir)
2681 goto out_put_leader;
2682
2683 name.name = buf;
2684 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2685 dentry = d_hash_and_lookup(dir, &name);
2686 if (dentry) {
2687 shrink_dcache_parent(dentry);
2688 d_drop(dentry);
2689 dput(dentry);
2690 }
2691
2692 dput(dir);
2693 out_put_leader:
2694 dput(leader);
2695 out:
2696 return;
2697 }
2698
2699 /**
2700 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2701 * @task: task that should be flushed.
2702 *
2703 * When flushing dentries from proc, one needs to flush them from global
2704 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2705 * in. This call is supposed to do all of this job.
2706 *
2707 * Looks in the dcache for
2708 * /proc/@pid
2709 * /proc/@tgid/task/@pid
2710 * if either directory is present flushes it and all of it'ts children
2711 * from the dcache.
2712 *
2713 * It is safe and reasonable to cache /proc entries for a task until
2714 * that task exits. After that they just clog up the dcache with
2715 * useless entries, possibly causing useful dcache entries to be
2716 * flushed instead. This routine is proved to flush those useless
2717 * dcache entries at process exit time.
2718 *
2719 * NOTE: This routine is just an optimization so it does not guarantee
2720 * that no dcache entries will exist at process exit time it
2721 * just makes it very unlikely that any will persist.
2722 */
2723
2724 void proc_flush_task(struct task_struct *task)
2725 {
2726 int i;
2727 struct pid *pid, *tgid;
2728 struct upid *upid;
2729
2730 pid = task_pid(task);
2731 tgid = task_tgid(task);
2732
2733 for (i = 0; i <= pid->level; i++) {
2734 upid = &pid->numbers[i];
2735 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2736 tgid->numbers[i].nr);
2737 }
2738
2739 upid = &pid->numbers[pid->level];
2740 if (upid->nr == 1)
2741 pid_ns_release_proc(upid->ns);
2742 }
2743
2744 static struct dentry *proc_pid_instantiate(struct inode *dir,
2745 struct dentry * dentry,
2746 struct task_struct *task, const void *ptr)
2747 {
2748 struct dentry *error = ERR_PTR(-ENOENT);
2749 struct inode *inode;
2750
2751 inode = proc_pid_make_inode(dir->i_sb, task);
2752 if (!inode)
2753 goto out;
2754
2755 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2756 inode->i_op = &proc_tgid_base_inode_operations;
2757 inode->i_fop = &proc_tgid_base_operations;
2758 inode->i_flags|=S_IMMUTABLE;
2759
2760 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
2761 ARRAY_SIZE(tgid_base_stuff));
2762
2763 dentry->d_op = &pid_dentry_operations;
2764
2765 d_add(dentry, inode);
2766 /* Close the race of the process dying before we return the dentry */
2767 if (pid_revalidate(dentry, NULL))
2768 error = NULL;
2769 out:
2770 return error;
2771 }
2772
2773 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2774 {
2775 struct dentry *result = ERR_PTR(-ENOENT);
2776 struct task_struct *task;
2777 unsigned tgid;
2778 struct pid_namespace *ns;
2779
2780 result = proc_base_lookup(dir, dentry);
2781 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
2782 goto out;
2783
2784 tgid = name_to_int(dentry);
2785 if (tgid == ~0U)
2786 goto out;
2787
2788 ns = dentry->d_sb->s_fs_info;
2789 rcu_read_lock();
2790 task = find_task_by_pid_ns(tgid, ns);
2791 if (task)
2792 get_task_struct(task);
2793 rcu_read_unlock();
2794 if (!task)
2795 goto out;
2796
2797 result = proc_pid_instantiate(dir, dentry, task, NULL);
2798 put_task_struct(task);
2799 out:
2800 return result;
2801 }
2802
2803 /*
2804 * Find the first task with tgid >= tgid
2805 *
2806 */
2807 struct tgid_iter {
2808 unsigned int tgid;
2809 struct task_struct *task;
2810 };
2811 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2812 {
2813 struct pid *pid;
2814
2815 if (iter.task)
2816 put_task_struct(iter.task);
2817 rcu_read_lock();
2818 retry:
2819 iter.task = NULL;
2820 pid = find_ge_pid(iter.tgid, ns);
2821 if (pid) {
2822 iter.tgid = pid_nr_ns(pid, ns);
2823 iter.task = pid_task(pid, PIDTYPE_PID);
2824 /* What we to know is if the pid we have find is the
2825 * pid of a thread_group_leader. Testing for task
2826 * being a thread_group_leader is the obvious thing
2827 * todo but there is a window when it fails, due to
2828 * the pid transfer logic in de_thread.
2829 *
2830 * So we perform the straight forward test of seeing
2831 * if the pid we have found is the pid of a thread
2832 * group leader, and don't worry if the task we have
2833 * found doesn't happen to be a thread group leader.
2834 * As we don't care in the case of readdir.
2835 */
2836 if (!iter.task || !has_group_leader_pid(iter.task)) {
2837 iter.tgid += 1;
2838 goto retry;
2839 }
2840 get_task_struct(iter.task);
2841 }
2842 rcu_read_unlock();
2843 return iter;
2844 }
2845
2846 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
2847
2848 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2849 struct tgid_iter iter)
2850 {
2851 char name[PROC_NUMBUF];
2852 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
2853 return proc_fill_cache(filp, dirent, filldir, name, len,
2854 proc_pid_instantiate, iter.task, NULL);
2855 }
2856
2857 /* for the /proc/ directory itself, after non-process stuff has been done */
2858 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2859 {
2860 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2861 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode);
2862 struct tgid_iter iter;
2863 struct pid_namespace *ns;
2864
2865 if (!reaper)
2866 goto out_no_task;
2867
2868 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
2869 const struct pid_entry *p = &proc_base_stuff[nr];
2870 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
2871 goto out;
2872 }
2873
2874 ns = filp->f_dentry->d_sb->s_fs_info;
2875 iter.task = NULL;
2876 iter.tgid = filp->f_pos - TGID_OFFSET;
2877 for (iter = next_tgid(ns, iter);
2878 iter.task;
2879 iter.tgid += 1, iter = next_tgid(ns, iter)) {
2880 filp->f_pos = iter.tgid + TGID_OFFSET;
2881 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
2882 put_task_struct(iter.task);
2883 goto out;
2884 }
2885 }
2886 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
2887 out:
2888 put_task_struct(reaper);
2889 out_no_task:
2890 return 0;
2891 }
2892
2893 /*
2894 * Tasks
2895 */
2896 static const struct pid_entry tid_base_stuff[] = {
2897 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2898 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fd_operations),
2899 REG("environ", S_IRUSR, proc_environ_operations),
2900 INF("auxv", S_IRUSR, proc_pid_auxv),
2901 ONE("status", S_IRUGO, proc_pid_status),
2902 ONE("personality", S_IRUSR, proc_pid_personality),
2903 INF("limits", S_IRUSR, proc_pid_limits),
2904 #ifdef CONFIG_SCHED_DEBUG
2905 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2906 #endif
2907 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2908 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2909 INF("syscall", S_IRUSR, proc_pid_syscall),
2910 #endif
2911 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2912 ONE("stat", S_IRUGO, proc_tid_stat),
2913 ONE("statm", S_IRUGO, proc_pid_statm),
2914 REG("maps", S_IRUGO, proc_maps_operations),
2915 #ifdef CONFIG_NUMA
2916 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
2917 #endif
2918 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2919 LNK("cwd", proc_cwd_link),
2920 LNK("root", proc_root_link),
2921 LNK("exe", proc_exe_link),
2922 REG("mounts", S_IRUGO, proc_mounts_operations),
2923 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2924 #ifdef CONFIG_PROC_PAGE_MONITOR
2925 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2926 REG("smaps", S_IRUGO, proc_smaps_operations),
2927 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2928 #endif
2929 #ifdef CONFIG_SECURITY
2930 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2931 #endif
2932 #ifdef CONFIG_KALLSYMS
2933 INF("wchan", S_IRUGO, proc_pid_wchan),
2934 #endif
2935 #ifdef CONFIG_STACKTRACE
2936 ONE("stack", S_IRUSR, proc_pid_stack),
2937 #endif
2938 #ifdef CONFIG_SCHEDSTATS
2939 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2940 #endif
2941 #ifdef CONFIG_LATENCYTOP
2942 REG("latency", S_IRUGO, proc_lstats_operations),
2943 #endif
2944 #ifdef CONFIG_PROC_PID_CPUSET
2945 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2946 #endif
2947 #ifdef CONFIG_CGROUPS
2948 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2949 #endif
2950 INF("oom_score", S_IRUGO, proc_oom_score),
2951 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2952 #ifdef CONFIG_AUDITSYSCALL
2953 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2954 REG("sessionid", S_IRUSR, proc_sessionid_operations),
2955 #endif
2956 #ifdef CONFIG_FAULT_INJECTION
2957 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2958 #endif
2959 #ifdef CONFIG_TASK_IO_ACCOUNTING
2960 INF("io", S_IRUGO, proc_tid_io_accounting),
2961 #endif
2962 };
2963
2964 static int proc_tid_base_readdir(struct file * filp,
2965 void * dirent, filldir_t filldir)
2966 {
2967 return proc_pident_readdir(filp,dirent,filldir,
2968 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
2969 }
2970
2971 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2972 return proc_pident_lookup(dir, dentry,
2973 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
2974 }
2975
2976 static const struct file_operations proc_tid_base_operations = {
2977 .read = generic_read_dir,
2978 .readdir = proc_tid_base_readdir,
2979 };
2980
2981 static const struct inode_operations proc_tid_base_inode_operations = {
2982 .lookup = proc_tid_base_lookup,
2983 .getattr = pid_getattr,
2984 .setattr = proc_setattr,
2985 };
2986
2987 static struct dentry *proc_task_instantiate(struct inode *dir,
2988 struct dentry *dentry, struct task_struct *task, const void *ptr)
2989 {
2990 struct dentry *error = ERR_PTR(-ENOENT);
2991 struct inode *inode;
2992 inode = proc_pid_make_inode(dir->i_sb, task);
2993
2994 if (!inode)
2995 goto out;
2996 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2997 inode->i_op = &proc_tid_base_inode_operations;
2998 inode->i_fop = &proc_tid_base_operations;
2999 inode->i_flags|=S_IMMUTABLE;
3000
3001 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
3002 ARRAY_SIZE(tid_base_stuff));
3003
3004 dentry->d_op = &pid_dentry_operations;
3005
3006 d_add(dentry, inode);
3007 /* Close the race of the process dying before we return the dentry */
3008 if (pid_revalidate(dentry, NULL))
3009 error = NULL;
3010 out:
3011 return error;
3012 }
3013
3014 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3015 {
3016 struct dentry *result = ERR_PTR(-ENOENT);
3017 struct task_struct *task;
3018 struct task_struct *leader = get_proc_task(dir);
3019 unsigned tid;
3020 struct pid_namespace *ns;
3021
3022 if (!leader)
3023 goto out_no_task;
3024
3025 tid = name_to_int(dentry);
3026 if (tid == ~0U)
3027 goto out;
3028
3029 ns = dentry->d_sb->s_fs_info;
3030 rcu_read_lock();
3031 task = find_task_by_pid_ns(tid, ns);
3032 if (task)
3033 get_task_struct(task);
3034 rcu_read_unlock();
3035 if (!task)
3036 goto out;
3037 if (!same_thread_group(leader, task))
3038 goto out_drop_task;
3039
3040 result = proc_task_instantiate(dir, dentry, task, NULL);
3041 out_drop_task:
3042 put_task_struct(task);
3043 out:
3044 put_task_struct(leader);
3045 out_no_task:
3046 return result;
3047 }
3048
3049 /*
3050 * Find the first tid of a thread group to return to user space.
3051 *
3052 * Usually this is just the thread group leader, but if the users
3053 * buffer was too small or there was a seek into the middle of the
3054 * directory we have more work todo.
3055 *
3056 * In the case of a short read we start with find_task_by_pid.
3057 *
3058 * In the case of a seek we start with the leader and walk nr
3059 * threads past it.
3060 */
3061 static struct task_struct *first_tid(struct task_struct *leader,
3062 int tid, int nr, struct pid_namespace *ns)
3063 {
3064 struct task_struct *pos;
3065
3066 rcu_read_lock();
3067 /* Attempt to start with the pid of a thread */
3068 if (tid && (nr > 0)) {
3069 pos = find_task_by_pid_ns(tid, ns);
3070 if (pos && (pos->group_leader == leader))
3071 goto found;
3072 }
3073
3074 /* If nr exceeds the number of threads there is nothing todo */
3075 pos = NULL;
3076 if (nr && nr >= get_nr_threads(leader))
3077 goto out;
3078
3079 /* If we haven't found our starting place yet start
3080 * with the leader and walk nr threads forward.
3081 */
3082 for (pos = leader; nr > 0; --nr) {
3083 pos = next_thread(pos);
3084 if (pos == leader) {
3085 pos = NULL;
3086 goto out;
3087 }
3088 }
3089 found:
3090 get_task_struct(pos);
3091 out:
3092 rcu_read_unlock();
3093 return pos;
3094 }
3095
3096 /*
3097 * Find the next thread in the thread list.
3098 * Return NULL if there is an error or no next thread.
3099 *
3100 * The reference to the input task_struct is released.
3101 */
3102 static struct task_struct *next_tid(struct task_struct *start)
3103 {
3104 struct task_struct *pos = NULL;
3105 rcu_read_lock();
3106 if (pid_alive(start)) {
3107 pos = next_thread(start);
3108 if (thread_group_leader(pos))
3109 pos = NULL;
3110 else
3111 get_task_struct(pos);
3112 }
3113 rcu_read_unlock();
3114 put_task_struct(start);
3115 return pos;
3116 }
3117
3118 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3119 struct task_struct *task, int tid)
3120 {
3121 char name[PROC_NUMBUF];
3122 int len = snprintf(name, sizeof(name), "%d", tid);
3123 return proc_fill_cache(filp, dirent, filldir, name, len,
3124 proc_task_instantiate, task, NULL);
3125 }
3126
3127 /* for the /proc/TGID/task/ directories */
3128 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3129 {
3130 struct dentry *dentry = filp->f_path.dentry;
3131 struct inode *inode = dentry->d_inode;
3132 struct task_struct *leader = NULL;
3133 struct task_struct *task;
3134 int retval = -ENOENT;
3135 ino_t ino;
3136 int tid;
3137 struct pid_namespace *ns;
3138
3139 task = get_proc_task(inode);
3140 if (!task)
3141 goto out_no_task;
3142 rcu_read_lock();
3143 if (pid_alive(task)) {
3144 leader = task->group_leader;
3145 get_task_struct(leader);
3146 }
3147 rcu_read_unlock();
3148 put_task_struct(task);
3149 if (!leader)
3150 goto out_no_task;
3151 retval = 0;
3152
3153 switch ((unsigned long)filp->f_pos) {
3154 case 0:
3155 ino = inode->i_ino;
3156 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3157 goto out;
3158 filp->f_pos++;
3159 /* fall through */
3160 case 1:
3161 ino = parent_ino(dentry);
3162 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3163 goto out;
3164 filp->f_pos++;
3165 /* fall through */
3166 }
3167
3168 /* f_version caches the tgid value that the last readdir call couldn't
3169 * return. lseek aka telldir automagically resets f_version to 0.
3170 */
3171 ns = filp->f_dentry->d_sb->s_fs_info;
3172 tid = (int)filp->f_version;
3173 filp->f_version = 0;
3174 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3175 task;
3176 task = next_tid(task), filp->f_pos++) {
3177 tid = task_pid_nr_ns(task, ns);
3178 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3179 /* returning this tgid failed, save it as the first
3180 * pid for the next readir call */
3181 filp->f_version = (u64)tid;
3182 put_task_struct(task);
3183 break;
3184 }
3185 }
3186 out:
3187 put_task_struct(leader);
3188 out_no_task:
3189 return retval;
3190 }
3191
3192 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3193 {
3194 struct inode *inode = dentry->d_inode;
3195 struct task_struct *p = get_proc_task(inode);
3196 generic_fillattr(inode, stat);
3197
3198 if (p) {
3199 stat->nlink += get_nr_threads(p);
3200 put_task_struct(p);
3201 }
3202
3203 return 0;
3204 }
3205
3206 static const struct inode_operations proc_task_inode_operations = {
3207 .lookup = proc_task_lookup,
3208 .getattr = proc_task_getattr,
3209 .setattr = proc_setattr,
3210 };
3211
3212 static const struct file_operations proc_task_operations = {
3213 .read = generic_read_dir,
3214 .readdir = proc_task_readdir,
3215 };
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