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Merge branch 'fix/asoc' into for-linus
[linux-2.6/next.git] / fs / proc / base.c
blobf3d02ca461ecfcc341eb783fd15da8df486fde11
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 /*
195 * Return zero if current may access user memory in @task, -error if not.
196 */
197 static int check_mem_permission(struct task_struct *task)
198 {
199 /*
200 * A task can always look at itself, in case it chooses
201 * to use system calls instead of load instructions.
202 */
203 if (task == current)
204 return 0;
205
206 /*
207 * If current is actively ptrace'ing, and would also be
208 * permitted to freshly attach with ptrace now, permit it.
209 */
210 if (task_is_stopped_or_traced(task)) {
211 int match;
212 rcu_read_lock();
213 match = (tracehook_tracer_task(task) == current);
214 rcu_read_unlock();
215 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
216 return 0;
217 }
218
219 /*
220 * Noone else is allowed.
221 */
222 return -EPERM;
223 }
224
225 struct mm_struct *mm_for_maps(struct task_struct *task)
226 {
227 struct mm_struct *mm;
228
229 if (mutex_lock_killable(&task->signal->cred_guard_mutex))
230 return NULL;
231
232 mm = get_task_mm(task);
233 if (mm && mm != current->mm &&
234 !ptrace_may_access(task, PTRACE_MODE_READ)) {
235 mmput(mm);
236 mm = NULL;
237 }
238 mutex_unlock(&task->signal->cred_guard_mutex);
239
240 return mm;
241 }
242
243 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
244 {
245 int res = 0;
246 unsigned int len;
247 struct mm_struct *mm = get_task_mm(task);
248 if (!mm)
249 goto out;
250 if (!mm->arg_end)
251 goto out_mm; /* Shh! No looking before we're done */
252
253 len = mm->arg_end - mm->arg_start;
254
255 if (len > PAGE_SIZE)
256 len = PAGE_SIZE;
257
258 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
259
260 // If the nul at the end of args has been overwritten, then
261 // assume application is using setproctitle(3).
262 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
263 len = strnlen(buffer, res);
264 if (len < res) {
265 res = len;
266 } else {
267 len = mm->env_end - mm->env_start;
268 if (len > PAGE_SIZE - res)
269 len = PAGE_SIZE - res;
270 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
271 res = strnlen(buffer, res);
272 }
273 }
274 out_mm:
275 mmput(mm);
276 out:
277 return res;
278 }
279
280 static int proc_pid_auxv(struct task_struct *task, char *buffer)
281 {
282 int res = 0;
283 struct mm_struct *mm = get_task_mm(task);
284 if (mm) {
285 unsigned int nwords = 0;
286 do {
287 nwords += 2;
288 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
289 res = nwords * sizeof(mm->saved_auxv[0]);
290 if (res > PAGE_SIZE)
291 res = PAGE_SIZE;
292 memcpy(buffer, mm->saved_auxv, res);
293 mmput(mm);
294 }
295 return res;
296 }
297
298
299 #ifdef CONFIG_KALLSYMS
300 /*
301 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
302 * Returns the resolved symbol. If that fails, simply return the address.
303 */
304 static int proc_pid_wchan(struct task_struct *task, char *buffer)
305 {
306 unsigned long wchan;
307 char symname[KSYM_NAME_LEN];
308
309 wchan = get_wchan(task);
310
311 if (lookup_symbol_name(wchan, symname) < 0)
312 if (!ptrace_may_access(task, PTRACE_MODE_READ))
313 return 0;
314 else
315 return sprintf(buffer, "%lu", wchan);
316 else
317 return sprintf(buffer, "%s", symname);
318 }
319 #endif /* CONFIG_KALLSYMS */
320
321 #ifdef CONFIG_STACKTRACE
322
323 #define MAX_STACK_TRACE_DEPTH 64
324
325 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
326 struct pid *pid, struct task_struct *task)
327 {
328 struct stack_trace trace;
329 unsigned long *entries;
330 int i;
331
332 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
333 if (!entries)
334 return -ENOMEM;
335
336 trace.nr_entries = 0;
337 trace.max_entries = MAX_STACK_TRACE_DEPTH;
338 trace.entries = entries;
339 trace.skip = 0;
340 save_stack_trace_tsk(task, &trace);
341
342 for (i = 0; i < trace.nr_entries; i++) {
343 seq_printf(m, "[<%p>] %pS\n",
344 (void *)entries[i], (void *)entries[i]);
345 }
346 kfree(entries);
347
348 return 0;
349 }
350 #endif
351
352 #ifdef CONFIG_SCHEDSTATS
353 /*
354 * Provides /proc/PID/schedstat
355 */
356 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
357 {
358 return sprintf(buffer, "%llu %llu %lu\n",
359 (unsigned long long)task->se.sum_exec_runtime,
360 (unsigned long long)task->sched_info.run_delay,
361 task->sched_info.pcount);
362 }
363 #endif
364
365 #ifdef CONFIG_LATENCYTOP
366 static int lstats_show_proc(struct seq_file *m, void *v)
367 {
368 int i;
369 struct inode *inode = m->private;
370 struct task_struct *task = get_proc_task(inode);
371
372 if (!task)
373 return -ESRCH;
374 seq_puts(m, "Latency Top version : v0.1\n");
375 for (i = 0; i < 32; i++) {
376 if (task->latency_record[i].backtrace[0]) {
377 int q;
378 seq_printf(m, "%i %li %li ",
379 task->latency_record[i].count,
380 task->latency_record[i].time,
381 task->latency_record[i].max);
382 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
383 char sym[KSYM_SYMBOL_LEN];
384 char *c;
385 if (!task->latency_record[i].backtrace[q])
386 break;
387 if (task->latency_record[i].backtrace[q] == ULONG_MAX)
388 break;
389 sprint_symbol(sym, task->latency_record[i].backtrace[q]);
390 c = strchr(sym, '+');
391 if (c)
392 *c = 0;
393 seq_printf(m, "%s ", sym);
394 }
395 seq_printf(m, "\n");
396 }
397
398 }
399 put_task_struct(task);
400 return 0;
401 }
402
403 static int lstats_open(struct inode *inode, struct file *file)
404 {
405 return single_open(file, lstats_show_proc, inode);
406 }
407
408 static ssize_t lstats_write(struct file *file, const char __user *buf,
409 size_t count, loff_t *offs)
410 {
411 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
412
413 if (!task)
414 return -ESRCH;
415 clear_all_latency_tracing(task);
416 put_task_struct(task);
417
418 return count;
419 }
420
421 static const struct file_operations proc_lstats_operations = {
422 .open = lstats_open,
423 .read = seq_read,
424 .write = lstats_write,
425 .llseek = seq_lseek,
426 .release = single_release,
427 };
428
429 #endif
430
431 static int proc_oom_score(struct task_struct *task, char *buffer)
432 {
433 unsigned long points = 0;
434
435 read_lock(&tasklist_lock);
436 if (pid_alive(task))
437 points = oom_badness(task, NULL, NULL,
438 totalram_pages + total_swap_pages);
439 read_unlock(&tasklist_lock);
440 return sprintf(buffer, "%lu\n", points);
441 }
442
443 struct limit_names {
444 char *name;
445 char *unit;
446 };
447
448 static const struct limit_names lnames[RLIM_NLIMITS] = {
449 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
450 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
451 [RLIMIT_DATA] = {"Max data size", "bytes"},
452 [RLIMIT_STACK] = {"Max stack size", "bytes"},
453 [RLIMIT_CORE] = {"Max core file size", "bytes"},
454 [RLIMIT_RSS] = {"Max resident set", "bytes"},
455 [RLIMIT_NPROC] = {"Max processes", "processes"},
456 [RLIMIT_NOFILE] = {"Max open files", "files"},
457 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
458 [RLIMIT_AS] = {"Max address space", "bytes"},
459 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
460 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
461 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
462 [RLIMIT_NICE] = {"Max nice priority", NULL},
463 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
464 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
465 };
466
467 /* Display limits for a process */
468 static int proc_pid_limits(struct task_struct *task, char *buffer)
469 {
470 unsigned int i;
471 int count = 0;
472 unsigned long flags;
473 char *bufptr = buffer;
474
475 struct rlimit rlim[RLIM_NLIMITS];
476
477 if (!lock_task_sighand(task, &flags))
478 return 0;
479 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
480 unlock_task_sighand(task, &flags);
481
482 /*
483 * print the file header
484 */
485 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
486 "Limit", "Soft Limit", "Hard Limit", "Units");
487
488 for (i = 0; i < RLIM_NLIMITS; i++) {
489 if (rlim[i].rlim_cur == RLIM_INFINITY)
490 count += sprintf(&bufptr[count], "%-25s %-20s ",
491 lnames[i].name, "unlimited");
492 else
493 count += sprintf(&bufptr[count], "%-25s %-20lu ",
494 lnames[i].name, rlim[i].rlim_cur);
495
496 if (rlim[i].rlim_max == RLIM_INFINITY)
497 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
498 else
499 count += sprintf(&bufptr[count], "%-20lu ",
500 rlim[i].rlim_max);
501
502 if (lnames[i].unit)
503 count += sprintf(&bufptr[count], "%-10s\n",
504 lnames[i].unit);
505 else
506 count += sprintf(&bufptr[count], "\n");
507 }
508
509 return count;
510 }
511
512 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
513 static int proc_pid_syscall(struct task_struct *task, char *buffer)
514 {
515 long nr;
516 unsigned long args[6], sp, pc;
517
518 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
519 return sprintf(buffer, "running\n");
520
521 if (nr < 0)
522 return sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
523
524 return sprintf(buffer,
525 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
526 nr,
527 args[0], args[1], args[2], args[3], args[4], args[5],
528 sp, pc);
529 }
530 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
531
532 /************************************************************************/
533 /* Here the fs part begins */
534 /************************************************************************/
535
536 /* permission checks */
537 static int proc_fd_access_allowed(struct inode *inode)
538 {
539 struct task_struct *task;
540 int allowed = 0;
541 /* Allow access to a task's file descriptors if it is us or we
542 * may use ptrace attach to the process and find out that
543 * information.
544 */
545 task = get_proc_task(inode);
546 if (task) {
547 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
548 put_task_struct(task);
549 }
550 return allowed;
551 }
552
553 static int proc_setattr(struct dentry *dentry, struct iattr *attr)
554 {
555 int error;
556 struct inode *inode = dentry->d_inode;
557
558 if (attr->ia_valid & ATTR_MODE)
559 return -EPERM;
560
561 error = inode_change_ok(inode, attr);
562 if (error)
563 return error;
564
565 if ((attr->ia_valid & ATTR_SIZE) &&
566 attr->ia_size != i_size_read(inode)) {
567 error = vmtruncate(inode, attr->ia_size);
568 if (error)
569 return error;
570 }
571
572 setattr_copy(inode, attr);
573 mark_inode_dirty(inode);
574 return 0;
575 }
576
577 static const struct inode_operations proc_def_inode_operations = {
578 .setattr = proc_setattr,
579 };
580
581 static int mounts_open_common(struct inode *inode, struct file *file,
582 const struct seq_operations *op)
583 {
584 struct task_struct *task = get_proc_task(inode);
585 struct nsproxy *nsp;
586 struct mnt_namespace *ns = NULL;
587 struct path root;
588 struct proc_mounts *p;
589 int ret = -EINVAL;
590
591 if (task) {
592 rcu_read_lock();
593 nsp = task_nsproxy(task);
594 if (nsp) {
595 ns = nsp->mnt_ns;
596 if (ns)
597 get_mnt_ns(ns);
598 }
599 rcu_read_unlock();
600 if (ns && get_task_root(task, &root) == 0)
601 ret = 0;
602 put_task_struct(task);
603 }
604
605 if (!ns)
606 goto err;
607 if (ret)
608 goto err_put_ns;
609
610 ret = -ENOMEM;
611 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
612 if (!p)
613 goto err_put_path;
614
615 file->private_data = &p->m;
616 ret = seq_open(file, op);
617 if (ret)
618 goto err_free;
619
620 p->m.private = p;
621 p->ns = ns;
622 p->root = root;
623 p->event = ns->event;
624
625 return 0;
626
627 err_free:
628 kfree(p);
629 err_put_path:
630 path_put(&root);
631 err_put_ns:
632 put_mnt_ns(ns);
633 err:
634 return ret;
635 }
636
637 static int mounts_release(struct inode *inode, struct file *file)
638 {
639 struct proc_mounts *p = file->private_data;
640 path_put(&p->root);
641 put_mnt_ns(p->ns);
642 return seq_release(inode, file);
643 }
644
645 static unsigned mounts_poll(struct file *file, poll_table *wait)
646 {
647 struct proc_mounts *p = file->private_data;
648 unsigned res = POLLIN | POLLRDNORM;
649
650 poll_wait(file, &p->ns->poll, wait);
651 if (mnt_had_events(p))
652 res |= POLLERR | POLLPRI;
653
654 return res;
655 }
656
657 static int mounts_open(struct inode *inode, struct file *file)
658 {
659 return mounts_open_common(inode, file, &mounts_op);
660 }
661
662 static const struct file_operations proc_mounts_operations = {
663 .open = mounts_open,
664 .read = seq_read,
665 .llseek = seq_lseek,
666 .release = mounts_release,
667 .poll = mounts_poll,
668 };
669
670 static int mountinfo_open(struct inode *inode, struct file *file)
671 {
672 return mounts_open_common(inode, file, &mountinfo_op);
673 }
674
675 static const struct file_operations proc_mountinfo_operations = {
676 .open = mountinfo_open,
677 .read = seq_read,
678 .llseek = seq_lseek,
679 .release = mounts_release,
680 .poll = mounts_poll,
681 };
682
683 static int mountstats_open(struct inode *inode, struct file *file)
684 {
685 return mounts_open_common(inode, file, &mountstats_op);
686 }
687
688 static const struct file_operations proc_mountstats_operations = {
689 .open = mountstats_open,
690 .read = seq_read,
691 .llseek = seq_lseek,
692 .release = mounts_release,
693 };
694
695 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
696
697 static ssize_t proc_info_read(struct file * file, char __user * buf,
698 size_t count, loff_t *ppos)
699 {
700 struct inode * inode = file->f_path.dentry->d_inode;
701 unsigned long page;
702 ssize_t length;
703 struct task_struct *task = get_proc_task(inode);
704
705 length = -ESRCH;
706 if (!task)
707 goto out_no_task;
708
709 if (count > PROC_BLOCK_SIZE)
710 count = PROC_BLOCK_SIZE;
711
712 length = -ENOMEM;
713 if (!(page = __get_free_page(GFP_TEMPORARY)))
714 goto out;
715
716 length = PROC_I(inode)->op.proc_read(task, (char*)page);
717
718 if (length >= 0)
719 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
720 free_page(page);
721 out:
722 put_task_struct(task);
723 out_no_task:
724 return length;
725 }
726
727 static const struct file_operations proc_info_file_operations = {
728 .read = proc_info_read,
729 .llseek = generic_file_llseek,
730 };
731
732 static int proc_single_show(struct seq_file *m, void *v)
733 {
734 struct inode *inode = m->private;
735 struct pid_namespace *ns;
736 struct pid *pid;
737 struct task_struct *task;
738 int ret;
739
740 ns = inode->i_sb->s_fs_info;
741 pid = proc_pid(inode);
742 task = get_pid_task(pid, PIDTYPE_PID);
743 if (!task)
744 return -ESRCH;
745
746 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
747
748 put_task_struct(task);
749 return ret;
750 }
751
752 static int proc_single_open(struct inode *inode, struct file *filp)
753 {
754 int ret;
755 ret = single_open(filp, proc_single_show, NULL);
756 if (!ret) {
757 struct seq_file *m = filp->private_data;
758
759 m->private = inode;
760 }
761 return ret;
762 }
763
764 static const struct file_operations proc_single_file_operations = {
765 .open = proc_single_open,
766 .read = seq_read,
767 .llseek = seq_lseek,
768 .release = single_release,
769 };
770
771 static int mem_open(struct inode* inode, struct file* file)
772 {
773 file->private_data = (void*)((long)current->self_exec_id);
774 /* OK to pass negative loff_t, we can catch out-of-range */
775 file->f_mode |= FMODE_UNSIGNED_OFFSET;
776 return 0;
777 }
778
779 static ssize_t mem_read(struct file * file, char __user * buf,
780 size_t count, loff_t *ppos)
781 {
782 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
783 char *page;
784 unsigned long src = *ppos;
785 int ret = -ESRCH;
786 struct mm_struct *mm;
787
788 if (!task)
789 goto out_no_task;
790
791 if (check_mem_permission(task))
792 goto out;
793
794 ret = -ENOMEM;
795 page = (char *)__get_free_page(GFP_TEMPORARY);
796 if (!page)
797 goto out;
798
799 ret = 0;
800
801 mm = get_task_mm(task);
802 if (!mm)
803 goto out_free;
804
805 ret = -EIO;
806
807 if (file->private_data != (void*)((long)current->self_exec_id))
808 goto out_put;
809
810 ret = 0;
811
812 while (count > 0) {
813 int this_len, retval;
814
815 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
816 retval = access_process_vm(task, src, page, this_len, 0);
817 if (!retval || check_mem_permission(task)) {
818 if (!ret)
819 ret = -EIO;
820 break;
821 }
822
823 if (copy_to_user(buf, page, retval)) {
824 ret = -EFAULT;
825 break;
826 }
827
828 ret += retval;
829 src += retval;
830 buf += retval;
831 count -= retval;
832 }
833 *ppos = src;
834
835 out_put:
836 mmput(mm);
837 out_free:
838 free_page((unsigned long) page);
839 out:
840 put_task_struct(task);
841 out_no_task:
842 return ret;
843 }
844
845 #define mem_write NULL
846
847 #ifndef mem_write
848 /* This is a security hazard */
849 static ssize_t mem_write(struct file * file, const char __user *buf,
850 size_t count, loff_t *ppos)
851 {
852 int copied;
853 char *page;
854 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
855 unsigned long dst = *ppos;
856
857 copied = -ESRCH;
858 if (!task)
859 goto out_no_task;
860
861 if (check_mem_permission(task))
862 goto out;
863
864 copied = -ENOMEM;
865 page = (char *)__get_free_page(GFP_TEMPORARY);
866 if (!page)
867 goto out;
868
869 copied = 0;
870 while (count > 0) {
871 int this_len, retval;
872
873 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
874 if (copy_from_user(page, buf, this_len)) {
875 copied = -EFAULT;
876 break;
877 }
878 retval = access_process_vm(task, dst, page, this_len, 1);
879 if (!retval) {
880 if (!copied)
881 copied = -EIO;
882 break;
883 }
884 copied += retval;
885 buf += retval;
886 dst += retval;
887 count -= retval;
888 }
889 *ppos = dst;
890 free_page((unsigned long) page);
891 out:
892 put_task_struct(task);
893 out_no_task:
894 return copied;
895 }
896 #endif
897
898 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
899 {
900 switch (orig) {
901 case 0:
902 file->f_pos = offset;
903 break;
904 case 1:
905 file->f_pos += offset;
906 break;
907 default:
908 return -EINVAL;
909 }
910 force_successful_syscall_return();
911 return file->f_pos;
912 }
913
914 static const struct file_operations proc_mem_operations = {
915 .llseek = mem_lseek,
916 .read = mem_read,
917 .write = mem_write,
918 .open = mem_open,
919 };
920
921 static ssize_t environ_read(struct file *file, char __user *buf,
922 size_t count, loff_t *ppos)
923 {
924 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
925 char *page;
926 unsigned long src = *ppos;
927 int ret = -ESRCH;
928 struct mm_struct *mm;
929
930 if (!task)
931 goto out_no_task;
932
933 if (!ptrace_may_access(task, PTRACE_MODE_READ))
934 goto out;
935
936 ret = -ENOMEM;
937 page = (char *)__get_free_page(GFP_TEMPORARY);
938 if (!page)
939 goto out;
940
941 ret = 0;
942
943 mm = get_task_mm(task);
944 if (!mm)
945 goto out_free;
946
947 while (count > 0) {
948 int this_len, retval, max_len;
949
950 this_len = mm->env_end - (mm->env_start + src);
951
952 if (this_len <= 0)
953 break;
954
955 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
956 this_len = (this_len > max_len) ? max_len : this_len;
957
958 retval = access_process_vm(task, (mm->env_start + src),
959 page, this_len, 0);
960
961 if (retval <= 0) {
962 ret = retval;
963 break;
964 }
965
966 if (copy_to_user(buf, page, retval)) {
967 ret = -EFAULT;
968 break;
969 }
970
971 ret += retval;
972 src += retval;
973 buf += retval;
974 count -= retval;
975 }
976 *ppos = src;
977
978 mmput(mm);
979 out_free:
980 free_page((unsigned long) page);
981 out:
982 put_task_struct(task);
983 out_no_task:
984 return ret;
985 }
986
987 static const struct file_operations proc_environ_operations = {
988 .read = environ_read,
989 .llseek = generic_file_llseek,
990 };
991
992 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
993 size_t count, loff_t *ppos)
994 {
995 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
996 char buffer[PROC_NUMBUF];
997 size_t len;
998 int oom_adjust = OOM_DISABLE;
999 unsigned long flags;
1000
1001 if (!task)
1002 return -ESRCH;
1003
1004 if (lock_task_sighand(task, &flags)) {
1005 oom_adjust = task->signal->oom_adj;
1006 unlock_task_sighand(task, &flags);
1007 }
1008
1009 put_task_struct(task);
1010
1011 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
1012
1013 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1014 }
1015
1016 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
1017 size_t count, loff_t *ppos)
1018 {
1019 struct task_struct *task;
1020 char buffer[PROC_NUMBUF];
1021 long oom_adjust;
1022 unsigned long flags;
1023 int err;
1024
1025 memset(buffer, 0, sizeof(buffer));
1026 if (count > sizeof(buffer) - 1)
1027 count = sizeof(buffer) - 1;
1028 if (copy_from_user(buffer, buf, count)) {
1029 err = -EFAULT;
1030 goto out;
1031 }
1032
1033 err = strict_strtol(strstrip(buffer), 0, &oom_adjust);
1034 if (err)
1035 goto out;
1036 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
1037 oom_adjust != OOM_DISABLE) {
1038 err = -EINVAL;
1039 goto out;
1040 }
1041
1042 task = get_proc_task(file->f_path.dentry->d_inode);
1043 if (!task) {
1044 err = -ESRCH;
1045 goto out;
1046 }
1047
1048 task_lock(task);
1049 if (!task->mm) {
1050 err = -EINVAL;
1051 goto err_task_lock;
1052 }
1053
1054 if (!lock_task_sighand(task, &flags)) {
1055 err = -ESRCH;
1056 goto err_task_lock;
1057 }
1058
1059 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
1060 err = -EACCES;
1061 goto err_sighand;
1062 }
1063
1064 if (oom_adjust != task->signal->oom_adj) {
1065 if (oom_adjust == OOM_DISABLE)
1066 atomic_inc(&task->mm->oom_disable_count);
1067 if (task->signal->oom_adj == OOM_DISABLE)
1068 atomic_dec(&task->mm->oom_disable_count);
1069 }
1070
1071 /*
1072 * Warn that /proc/pid/oom_adj is deprecated, see
1073 * Documentation/feature-removal-schedule.txt.
1074 */
1075 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, "
1076 "please use /proc/%d/oom_score_adj instead.\n",
1077 current->comm, task_pid_nr(current),
1078 task_pid_nr(task), task_pid_nr(task));
1079 task->signal->oom_adj = oom_adjust;
1080 /*
1081 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1082 * value is always attainable.
1083 */
1084 if (task->signal->oom_adj == OOM_ADJUST_MAX)
1085 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
1086 else
1087 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
1088 -OOM_DISABLE;
1089 err_sighand:
1090 unlock_task_sighand(task, &flags);
1091 err_task_lock:
1092 task_unlock(task);
1093 put_task_struct(task);
1094 out:
1095 return err < 0 ? err : count;
1096 }
1097
1098 static const struct file_operations proc_oom_adjust_operations = {
1099 .read = oom_adjust_read,
1100 .write = oom_adjust_write,
1101 .llseek = generic_file_llseek,
1102 };
1103
1104 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1105 size_t count, loff_t *ppos)
1106 {
1107 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1108 char buffer[PROC_NUMBUF];
1109 int oom_score_adj = OOM_SCORE_ADJ_MIN;
1110 unsigned long flags;
1111 size_t len;
1112
1113 if (!task)
1114 return -ESRCH;
1115 if (lock_task_sighand(task, &flags)) {
1116 oom_score_adj = task->signal->oom_score_adj;
1117 unlock_task_sighand(task, &flags);
1118 }
1119 put_task_struct(task);
1120 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
1121 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1122 }
1123
1124 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1125 size_t count, loff_t *ppos)
1126 {
1127 struct task_struct *task;
1128 char buffer[PROC_NUMBUF];
1129 unsigned long flags;
1130 long oom_score_adj;
1131 int err;
1132
1133 memset(buffer, 0, sizeof(buffer));
1134 if (count > sizeof(buffer) - 1)
1135 count = sizeof(buffer) - 1;
1136 if (copy_from_user(buffer, buf, count)) {
1137 err = -EFAULT;
1138 goto out;
1139 }
1140
1141 err = strict_strtol(strstrip(buffer), 0, &oom_score_adj);
1142 if (err)
1143 goto out;
1144 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1145 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1146 err = -EINVAL;
1147 goto out;
1148 }
1149
1150 task = get_proc_task(file->f_path.dentry->d_inode);
1151 if (!task) {
1152 err = -ESRCH;
1153 goto out;
1154 }
1155
1156 task_lock(task);
1157 if (!task->mm) {
1158 err = -EINVAL;
1159 goto err_task_lock;
1160 }
1161
1162 if (!lock_task_sighand(task, &flags)) {
1163 err = -ESRCH;
1164 goto err_task_lock;
1165 }
1166
1167 if (oom_score_adj < task->signal->oom_score_adj &&
1168 !capable(CAP_SYS_RESOURCE)) {
1169 err = -EACCES;
1170 goto err_sighand;
1171 }
1172
1173 if (oom_score_adj != task->signal->oom_score_adj) {
1174 if (oom_score_adj == OOM_SCORE_ADJ_MIN)
1175 atomic_inc(&task->mm->oom_disable_count);
1176 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1177 atomic_dec(&task->mm->oom_disable_count);
1178 }
1179 task->signal->oom_score_adj = oom_score_adj;
1180 /*
1181 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1182 * always attainable.
1183 */
1184 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1185 task->signal->oom_adj = OOM_DISABLE;
1186 else
1187 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1188 OOM_SCORE_ADJ_MAX;
1189 err_sighand:
1190 unlock_task_sighand(task, &flags);
1191 err_task_lock:
1192 task_unlock(task);
1193 put_task_struct(task);
1194 out:
1195 return err < 0 ? err : count;
1196 }
1197
1198 static const struct file_operations proc_oom_score_adj_operations = {
1199 .read = oom_score_adj_read,
1200 .write = oom_score_adj_write,
1201 .llseek = default_llseek,
1202 };
1203
1204 #ifdef CONFIG_AUDITSYSCALL
1205 #define TMPBUFLEN 21
1206 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1207 size_t count, loff_t *ppos)
1208 {
1209 struct inode * inode = file->f_path.dentry->d_inode;
1210 struct task_struct *task = get_proc_task(inode);
1211 ssize_t length;
1212 char tmpbuf[TMPBUFLEN];
1213
1214 if (!task)
1215 return -ESRCH;
1216 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1217 audit_get_loginuid(task));
1218 put_task_struct(task);
1219 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1220 }
1221
1222 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1223 size_t count, loff_t *ppos)
1224 {
1225 struct inode * inode = file->f_path.dentry->d_inode;
1226 char *page, *tmp;
1227 ssize_t length;
1228 uid_t loginuid;
1229
1230 if (!capable(CAP_AUDIT_CONTROL))
1231 return -EPERM;
1232
1233 rcu_read_lock();
1234 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1235 rcu_read_unlock();
1236 return -EPERM;
1237 }
1238 rcu_read_unlock();
1239
1240 if (count >= PAGE_SIZE)
1241 count = PAGE_SIZE - 1;
1242
1243 if (*ppos != 0) {
1244 /* No partial writes. */
1245 return -EINVAL;
1246 }
1247 page = (char*)__get_free_page(GFP_TEMPORARY);
1248 if (!page)
1249 return -ENOMEM;
1250 length = -EFAULT;
1251 if (copy_from_user(page, buf, count))
1252 goto out_free_page;
1253
1254 page[count] = '\0';
1255 loginuid = simple_strtoul(page, &tmp, 10);
1256 if (tmp == page) {
1257 length = -EINVAL;
1258 goto out_free_page;
1259
1260 }
1261 length = audit_set_loginuid(current, loginuid);
1262 if (likely(length == 0))
1263 length = count;
1264
1265 out_free_page:
1266 free_page((unsigned long) page);
1267 return length;
1268 }
1269
1270 static const struct file_operations proc_loginuid_operations = {
1271 .read = proc_loginuid_read,
1272 .write = proc_loginuid_write,
1273 .llseek = generic_file_llseek,
1274 };
1275
1276 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1277 size_t count, loff_t *ppos)
1278 {
1279 struct inode * inode = file->f_path.dentry->d_inode;
1280 struct task_struct *task = get_proc_task(inode);
1281 ssize_t length;
1282 char tmpbuf[TMPBUFLEN];
1283
1284 if (!task)
1285 return -ESRCH;
1286 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1287 audit_get_sessionid(task));
1288 put_task_struct(task);
1289 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1290 }
1291
1292 static const struct file_operations proc_sessionid_operations = {
1293 .read = proc_sessionid_read,
1294 .llseek = generic_file_llseek,
1295 };
1296 #endif
1297
1298 #ifdef CONFIG_FAULT_INJECTION
1299 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1300 size_t count, loff_t *ppos)
1301 {
1302 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1303 char buffer[PROC_NUMBUF];
1304 size_t len;
1305 int make_it_fail;
1306
1307 if (!task)
1308 return -ESRCH;
1309 make_it_fail = task->make_it_fail;
1310 put_task_struct(task);
1311
1312 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1313
1314 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1315 }
1316
1317 static ssize_t proc_fault_inject_write(struct file * file,
1318 const char __user * buf, size_t count, loff_t *ppos)
1319 {
1320 struct task_struct *task;
1321 char buffer[PROC_NUMBUF], *end;
1322 int make_it_fail;
1323
1324 if (!capable(CAP_SYS_RESOURCE))
1325 return -EPERM;
1326 memset(buffer, 0, sizeof(buffer));
1327 if (count > sizeof(buffer) - 1)
1328 count = sizeof(buffer) - 1;
1329 if (copy_from_user(buffer, buf, count))
1330 return -EFAULT;
1331 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1332 if (*end)
1333 return -EINVAL;
1334 task = get_proc_task(file->f_dentry->d_inode);
1335 if (!task)
1336 return -ESRCH;
1337 task->make_it_fail = make_it_fail;
1338 put_task_struct(task);
1339
1340 return count;
1341 }
1342
1343 static const struct file_operations proc_fault_inject_operations = {
1344 .read = proc_fault_inject_read,
1345 .write = proc_fault_inject_write,
1346 .llseek = generic_file_llseek,
1347 };
1348 #endif
1349
1350
1351 #ifdef CONFIG_SCHED_DEBUG
1352 /*
1353 * Print out various scheduling related per-task fields:
1354 */
1355 static int sched_show(struct seq_file *m, void *v)
1356 {
1357 struct inode *inode = m->private;
1358 struct task_struct *p;
1359
1360 p = get_proc_task(inode);
1361 if (!p)
1362 return -ESRCH;
1363 proc_sched_show_task(p, m);
1364
1365 put_task_struct(p);
1366
1367 return 0;
1368 }
1369
1370 static ssize_t
1371 sched_write(struct file *file, const char __user *buf,
1372 size_t count, loff_t *offset)
1373 {
1374 struct inode *inode = file->f_path.dentry->d_inode;
1375 struct task_struct *p;
1376
1377 p = get_proc_task(inode);
1378 if (!p)
1379 return -ESRCH;
1380 proc_sched_set_task(p);
1381
1382 put_task_struct(p);
1383
1384 return count;
1385 }
1386
1387 static int sched_open(struct inode *inode, struct file *filp)
1388 {
1389 int ret;
1390
1391 ret = single_open(filp, sched_show, NULL);
1392 if (!ret) {
1393 struct seq_file *m = filp->private_data;
1394
1395 m->private = inode;
1396 }
1397 return ret;
1398 }
1399
1400 static const struct file_operations proc_pid_sched_operations = {
1401 .open = sched_open,
1402 .read = seq_read,
1403 .write = sched_write,
1404 .llseek = seq_lseek,
1405 .release = single_release,
1406 };
1407
1408 #endif
1409
1410 static ssize_t comm_write(struct file *file, const char __user *buf,
1411 size_t count, loff_t *offset)
1412 {
1413 struct inode *inode = file->f_path.dentry->d_inode;
1414 struct task_struct *p;
1415 char buffer[TASK_COMM_LEN];
1416
1417 memset(buffer, 0, sizeof(buffer));
1418 if (count > sizeof(buffer) - 1)
1419 count = sizeof(buffer) - 1;
1420 if (copy_from_user(buffer, buf, count))
1421 return -EFAULT;
1422
1423 p = get_proc_task(inode);
1424 if (!p)
1425 return -ESRCH;
1426
1427 if (same_thread_group(current, p))
1428 set_task_comm(p, buffer);
1429 else
1430 count = -EINVAL;
1431
1432 put_task_struct(p);
1433
1434 return count;
1435 }
1436
1437 static int comm_show(struct seq_file *m, void *v)
1438 {
1439 struct inode *inode = m->private;
1440 struct task_struct *p;
1441
1442 p = get_proc_task(inode);
1443 if (!p)
1444 return -ESRCH;
1445
1446 task_lock(p);
1447 seq_printf(m, "%s\n", p->comm);
1448 task_unlock(p);
1449
1450 put_task_struct(p);
1451
1452 return 0;
1453 }
1454
1455 static int comm_open(struct inode *inode, struct file *filp)
1456 {
1457 int ret;
1458
1459 ret = single_open(filp, comm_show, NULL);
1460 if (!ret) {
1461 struct seq_file *m = filp->private_data;
1462
1463 m->private = inode;
1464 }
1465 return ret;
1466 }
1467
1468 static const struct file_operations proc_pid_set_comm_operations = {
1469 .open = comm_open,
1470 .read = seq_read,
1471 .write = comm_write,
1472 .llseek = seq_lseek,
1473 .release = single_release,
1474 };
1475
1476 /*
1477 * We added or removed a vma mapping the executable. The vmas are only mapped
1478 * during exec and are not mapped with the mmap system call.
1479 * Callers must hold down_write() on the mm's mmap_sem for these
1480 */
1481 void added_exe_file_vma(struct mm_struct *mm)
1482 {
1483 mm->num_exe_file_vmas++;
1484 }
1485
1486 void removed_exe_file_vma(struct mm_struct *mm)
1487 {
1488 mm->num_exe_file_vmas--;
1489 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){
1490 fput(mm->exe_file);
1491 mm->exe_file = NULL;
1492 }
1493
1494 }
1495
1496 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file)
1497 {
1498 if (new_exe_file)
1499 get_file(new_exe_file);
1500 if (mm->exe_file)
1501 fput(mm->exe_file);
1502 mm->exe_file = new_exe_file;
1503 mm->num_exe_file_vmas = 0;
1504 }
1505
1506 struct file *get_mm_exe_file(struct mm_struct *mm)
1507 {
1508 struct file *exe_file;
1509
1510 /* We need mmap_sem to protect against races with removal of
1511 * VM_EXECUTABLE vmas */
1512 down_read(&mm->mmap_sem);
1513 exe_file = mm->exe_file;
1514 if (exe_file)
1515 get_file(exe_file);
1516 up_read(&mm->mmap_sem);
1517 return exe_file;
1518 }
1519
1520 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm)
1521 {
1522 /* It's safe to write the exe_file pointer without exe_file_lock because
1523 * this is called during fork when the task is not yet in /proc */
1524 newmm->exe_file = get_mm_exe_file(oldmm);
1525 }
1526
1527 static int proc_exe_link(struct inode *inode, struct path *exe_path)
1528 {
1529 struct task_struct *task;
1530 struct mm_struct *mm;
1531 struct file *exe_file;
1532
1533 task = get_proc_task(inode);
1534 if (!task)
1535 return -ENOENT;
1536 mm = get_task_mm(task);
1537 put_task_struct(task);
1538 if (!mm)
1539 return -ENOENT;
1540 exe_file = get_mm_exe_file(mm);
1541 mmput(mm);
1542 if (exe_file) {
1543 *exe_path = exe_file->f_path;
1544 path_get(&exe_file->f_path);
1545 fput(exe_file);
1546 return 0;
1547 } else
1548 return -ENOENT;
1549 }
1550
1551 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1552 {
1553 struct inode *inode = dentry->d_inode;
1554 int error = -EACCES;
1555
1556 /* We don't need a base pointer in the /proc filesystem */
1557 path_put(&nd->path);
1558
1559 /* Are we allowed to snoop on the tasks file descriptors? */
1560 if (!proc_fd_access_allowed(inode))
1561 goto out;
1562
1563 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
1564 out:
1565 return ERR_PTR(error);
1566 }
1567
1568 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1569 {
1570 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1571 char *pathname;
1572 int len;
1573
1574 if (!tmp)
1575 return -ENOMEM;
1576
1577 pathname = d_path_with_unreachable(path, tmp, PAGE_SIZE);
1578 len = PTR_ERR(pathname);
1579 if (IS_ERR(pathname))
1580 goto out;
1581 len = tmp + PAGE_SIZE - 1 - pathname;
1582
1583 if (len > buflen)
1584 len = buflen;
1585 if (copy_to_user(buffer, pathname, len))
1586 len = -EFAULT;
1587 out:
1588 free_page((unsigned long)tmp);
1589 return len;
1590 }
1591
1592 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1593 {
1594 int error = -EACCES;
1595 struct inode *inode = dentry->d_inode;
1596 struct path path;
1597
1598 /* Are we allowed to snoop on the tasks file descriptors? */
1599 if (!proc_fd_access_allowed(inode))
1600 goto out;
1601
1602 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1603 if (error)
1604 goto out;
1605
1606 error = do_proc_readlink(&path, buffer, buflen);
1607 path_put(&path);
1608 out:
1609 return error;
1610 }
1611
1612 static const struct inode_operations proc_pid_link_inode_operations = {
1613 .readlink = proc_pid_readlink,
1614 .follow_link = proc_pid_follow_link,
1615 .setattr = proc_setattr,
1616 };
1617
1618
1619 /* building an inode */
1620
1621 static int task_dumpable(struct task_struct *task)
1622 {
1623 int dumpable = 0;
1624 struct mm_struct *mm;
1625
1626 task_lock(task);
1627 mm = task->mm;
1628 if (mm)
1629 dumpable = get_dumpable(mm);
1630 task_unlock(task);
1631 if(dumpable == 1)
1632 return 1;
1633 return 0;
1634 }
1635
1636
1637 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1638 {
1639 struct inode * inode;
1640 struct proc_inode *ei;
1641 const struct cred *cred;
1642
1643 /* We need a new inode */
1644
1645 inode = new_inode(sb);
1646 if (!inode)
1647 goto out;
1648
1649 /* Common stuff */
1650 ei = PROC_I(inode);
1651 inode->i_ino = get_next_ino();
1652 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1653 inode->i_op = &proc_def_inode_operations;
1654
1655 /*
1656 * grab the reference to task.
1657 */
1658 ei->pid = get_task_pid(task, PIDTYPE_PID);
1659 if (!ei->pid)
1660 goto out_unlock;
1661
1662 if (task_dumpable(task)) {
1663 rcu_read_lock();
1664 cred = __task_cred(task);
1665 inode->i_uid = cred->euid;
1666 inode->i_gid = cred->egid;
1667 rcu_read_unlock();
1668 }
1669 security_task_to_inode(task, inode);
1670
1671 out:
1672 return inode;
1673
1674 out_unlock:
1675 iput(inode);
1676 return NULL;
1677 }
1678
1679 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1680 {
1681 struct inode *inode = dentry->d_inode;
1682 struct task_struct *task;
1683 const struct cred *cred;
1684
1685 generic_fillattr(inode, stat);
1686
1687 rcu_read_lock();
1688 stat->uid = 0;
1689 stat->gid = 0;
1690 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1691 if (task) {
1692 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1693 task_dumpable(task)) {
1694 cred = __task_cred(task);
1695 stat->uid = cred->euid;
1696 stat->gid = cred->egid;
1697 }
1698 }
1699 rcu_read_unlock();
1700 return 0;
1701 }
1702
1703 /* dentry stuff */
1704
1705 /*
1706 * Exceptional case: normally we are not allowed to unhash a busy
1707 * directory. In this case, however, we can do it - no aliasing problems
1708 * due to the way we treat inodes.
1709 *
1710 * Rewrite the inode's ownerships here because the owning task may have
1711 * performed a setuid(), etc.
1712 *
1713 * Before the /proc/pid/status file was created the only way to read
1714 * the effective uid of a /process was to stat /proc/pid. Reading
1715 * /proc/pid/status is slow enough that procps and other packages
1716 * kept stating /proc/pid. To keep the rules in /proc simple I have
1717 * made this apply to all per process world readable and executable
1718 * directories.
1719 */
1720 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1721 {
1722 struct inode *inode = dentry->d_inode;
1723 struct task_struct *task = get_proc_task(inode);
1724 const struct cred *cred;
1725
1726 if (task) {
1727 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1728 task_dumpable(task)) {
1729 rcu_read_lock();
1730 cred = __task_cred(task);
1731 inode->i_uid = cred->euid;
1732 inode->i_gid = cred->egid;
1733 rcu_read_unlock();
1734 } else {
1735 inode->i_uid = 0;
1736 inode->i_gid = 0;
1737 }
1738 inode->i_mode &= ~(S_ISUID | S_ISGID);
1739 security_task_to_inode(task, inode);
1740 put_task_struct(task);
1741 return 1;
1742 }
1743 d_drop(dentry);
1744 return 0;
1745 }
1746
1747 static int pid_delete_dentry(struct dentry * dentry)
1748 {
1749 /* Is the task we represent dead?
1750 * If so, then don't put the dentry on the lru list,
1751 * kill it immediately.
1752 */
1753 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1754 }
1755
1756 static const struct dentry_operations pid_dentry_operations =
1757 {
1758 .d_revalidate = pid_revalidate,
1759 .d_delete = pid_delete_dentry,
1760 };
1761
1762 /* Lookups */
1763
1764 typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
1765 struct task_struct *, const void *);
1766
1767 /*
1768 * Fill a directory entry.
1769 *
1770 * If possible create the dcache entry and derive our inode number and
1771 * file type from dcache entry.
1772 *
1773 * Since all of the proc inode numbers are dynamically generated, the inode
1774 * numbers do not exist until the inode is cache. This means creating the
1775 * the dcache entry in readdir is necessary to keep the inode numbers
1776 * reported by readdir in sync with the inode numbers reported
1777 * by stat.
1778 */
1779 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1780 char *name, int len,
1781 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1782 {
1783 struct dentry *child, *dir = filp->f_path.dentry;
1784 struct inode *inode;
1785 struct qstr qname;
1786 ino_t ino = 0;
1787 unsigned type = DT_UNKNOWN;
1788
1789 qname.name = name;
1790 qname.len = len;
1791 qname.hash = full_name_hash(name, len);
1792
1793 child = d_lookup(dir, &qname);
1794 if (!child) {
1795 struct dentry *new;
1796 new = d_alloc(dir, &qname);
1797 if (new) {
1798 child = instantiate(dir->d_inode, new, task, ptr);
1799 if (child)
1800 dput(new);
1801 else
1802 child = new;
1803 }
1804 }
1805 if (!child || IS_ERR(child) || !child->d_inode)
1806 goto end_instantiate;
1807 inode = child->d_inode;
1808 if (inode) {
1809 ino = inode->i_ino;
1810 type = inode->i_mode >> 12;
1811 }
1812 dput(child);
1813 end_instantiate:
1814 if (!ino)
1815 ino = find_inode_number(dir, &qname);
1816 if (!ino)
1817 ino = 1;
1818 return filldir(dirent, name, len, filp->f_pos, ino, type);
1819 }
1820
1821 static unsigned name_to_int(struct dentry *dentry)
1822 {
1823 const char *name = dentry->d_name.name;
1824 int len = dentry->d_name.len;
1825 unsigned n = 0;
1826
1827 if (len > 1 && *name == '0')
1828 goto out;
1829 while (len-- > 0) {
1830 unsigned c = *name++ - '0';
1831 if (c > 9)
1832 goto out;
1833 if (n >= (~0U-9)/10)
1834 goto out;
1835 n *= 10;
1836 n += c;
1837 }
1838 return n;
1839 out:
1840 return ~0U;
1841 }
1842
1843 #define PROC_FDINFO_MAX 64
1844
1845 static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1846 {
1847 struct task_struct *task = get_proc_task(inode);
1848 struct files_struct *files = NULL;
1849 struct file *file;
1850 int fd = proc_fd(inode);
1851
1852 if (task) {
1853 files = get_files_struct(task);
1854 put_task_struct(task);
1855 }
1856 if (files) {
1857 /*
1858 * We are not taking a ref to the file structure, so we must
1859 * hold ->file_lock.
1860 */
1861 spin_lock(&files->file_lock);
1862 file = fcheck_files(files, fd);
1863 if (file) {
1864 if (path) {
1865 *path = file->f_path;
1866 path_get(&file->f_path);
1867 }
1868 if (info)
1869 snprintf(info, PROC_FDINFO_MAX,
1870 "pos:\t%lli\n"
1871 "flags:\t0%o\n",
1872 (long long) file->f_pos,
1873 file->f_flags);
1874 spin_unlock(&files->file_lock);
1875 put_files_struct(files);
1876 return 0;
1877 }
1878 spin_unlock(&files->file_lock);
1879 put_files_struct(files);
1880 }
1881 return -ENOENT;
1882 }
1883
1884 static int proc_fd_link(struct inode *inode, struct path *path)
1885 {
1886 return proc_fd_info(inode, path, NULL);
1887 }
1888
1889 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1890 {
1891 struct inode *inode = dentry->d_inode;
1892 struct task_struct *task = get_proc_task(inode);
1893 int fd = proc_fd(inode);
1894 struct files_struct *files;
1895 const struct cred *cred;
1896
1897 if (task) {
1898 files = get_files_struct(task);
1899 if (files) {
1900 rcu_read_lock();
1901 if (fcheck_files(files, fd)) {
1902 rcu_read_unlock();
1903 put_files_struct(files);
1904 if (task_dumpable(task)) {
1905 rcu_read_lock();
1906 cred = __task_cred(task);
1907 inode->i_uid = cred->euid;
1908 inode->i_gid = cred->egid;
1909 rcu_read_unlock();
1910 } else {
1911 inode->i_uid = 0;
1912 inode->i_gid = 0;
1913 }
1914 inode->i_mode &= ~(S_ISUID | S_ISGID);
1915 security_task_to_inode(task, inode);
1916 put_task_struct(task);
1917 return 1;
1918 }
1919 rcu_read_unlock();
1920 put_files_struct(files);
1921 }
1922 put_task_struct(task);
1923 }
1924 d_drop(dentry);
1925 return 0;
1926 }
1927
1928 static const struct dentry_operations tid_fd_dentry_operations =
1929 {
1930 .d_revalidate = tid_fd_revalidate,
1931 .d_delete = pid_delete_dentry,
1932 };
1933
1934 static struct dentry *proc_fd_instantiate(struct inode *dir,
1935 struct dentry *dentry, struct task_struct *task, const void *ptr)
1936 {
1937 unsigned fd = *(const unsigned *)ptr;
1938 struct file *file;
1939 struct files_struct *files;
1940 struct inode *inode;
1941 struct proc_inode *ei;
1942 struct dentry *error = ERR_PTR(-ENOENT);
1943
1944 inode = proc_pid_make_inode(dir->i_sb, task);
1945 if (!inode)
1946 goto out;
1947 ei = PROC_I(inode);
1948 ei->fd = fd;
1949 files = get_files_struct(task);
1950 if (!files)
1951 goto out_iput;
1952 inode->i_mode = S_IFLNK;
1953
1954 /*
1955 * We are not taking a ref to the file structure, so we must
1956 * hold ->file_lock.
1957 */
1958 spin_lock(&files->file_lock);
1959 file = fcheck_files(files, fd);
1960 if (!file)
1961 goto out_unlock;
1962 if (file->f_mode & FMODE_READ)
1963 inode->i_mode |= S_IRUSR | S_IXUSR;
1964 if (file->f_mode & FMODE_WRITE)
1965 inode->i_mode |= S_IWUSR | S_IXUSR;
1966 spin_unlock(&files->file_lock);
1967 put_files_struct(files);
1968
1969 inode->i_op = &proc_pid_link_inode_operations;
1970 inode->i_size = 64;
1971 ei->op.proc_get_link = proc_fd_link;
1972 dentry->d_op = &tid_fd_dentry_operations;
1973 d_add(dentry, inode);
1974 /* Close the race of the process dying before we return the dentry */
1975 if (tid_fd_revalidate(dentry, NULL))
1976 error = NULL;
1977
1978 out:
1979 return error;
1980 out_unlock:
1981 spin_unlock(&files->file_lock);
1982 put_files_struct(files);
1983 out_iput:
1984 iput(inode);
1985 goto out;
1986 }
1987
1988 static struct dentry *proc_lookupfd_common(struct inode *dir,
1989 struct dentry *dentry,
1990 instantiate_t instantiate)
1991 {
1992 struct task_struct *task = get_proc_task(dir);
1993 unsigned fd = name_to_int(dentry);
1994 struct dentry *result = ERR_PTR(-ENOENT);
1995
1996 if (!task)
1997 goto out_no_task;
1998 if (fd == ~0U)
1999 goto out;
2000
2001 result = instantiate(dir, dentry, task, &fd);
2002 out:
2003 put_task_struct(task);
2004 out_no_task:
2005 return result;
2006 }
2007
2008 static int proc_readfd_common(struct file * filp, void * dirent,
2009 filldir_t filldir, instantiate_t instantiate)
2010 {
2011 struct dentry *dentry = filp->f_path.dentry;
2012 struct inode *inode = dentry->d_inode;
2013 struct task_struct *p = get_proc_task(inode);
2014 unsigned int fd, ino;
2015 int retval;
2016 struct files_struct * files;
2017
2018 retval = -ENOENT;
2019 if (!p)
2020 goto out_no_task;
2021 retval = 0;
2022
2023 fd = filp->f_pos;
2024 switch (fd) {
2025 case 0:
2026 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
2027 goto out;
2028 filp->f_pos++;
2029 case 1:
2030 ino = parent_ino(dentry);
2031 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
2032 goto out;
2033 filp->f_pos++;
2034 default:
2035 files = get_files_struct(p);
2036 if (!files)
2037 goto out;
2038 rcu_read_lock();
2039 for (fd = filp->f_pos-2;
2040 fd < files_fdtable(files)->max_fds;
2041 fd++, filp->f_pos++) {
2042 char name[PROC_NUMBUF];
2043 int len;
2044
2045 if (!fcheck_files(files, fd))
2046 continue;
2047 rcu_read_unlock();
2048
2049 len = snprintf(name, sizeof(name), "%d", fd);
2050 if (proc_fill_cache(filp, dirent, filldir,
2051 name, len, instantiate,
2052 p, &fd) < 0) {
2053 rcu_read_lock();
2054 break;
2055 }
2056 rcu_read_lock();
2057 }
2058 rcu_read_unlock();
2059 put_files_struct(files);
2060 }
2061 out:
2062 put_task_struct(p);
2063 out_no_task:
2064 return retval;
2065 }
2066
2067 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
2068 struct nameidata *nd)
2069 {
2070 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
2071 }
2072
2073 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
2074 {
2075 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
2076 }
2077
2078 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
2079 size_t len, loff_t *ppos)
2080 {
2081 char tmp[PROC_FDINFO_MAX];
2082 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
2083 if (!err)
2084 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
2085 return err;
2086 }
2087
2088 static const struct file_operations proc_fdinfo_file_operations = {
2089 .open = nonseekable_open,
2090 .read = proc_fdinfo_read,
2091 .llseek = no_llseek,
2092 };
2093
2094 static const struct file_operations proc_fd_operations = {
2095 .read = generic_read_dir,
2096 .readdir = proc_readfd,
2097 .llseek = default_llseek,
2098 };
2099
2100 /*
2101 * /proc/pid/fd needs a special permission handler so that a process can still
2102 * access /proc/self/fd after it has executed a setuid().
2103 */
2104 static int proc_fd_permission(struct inode *inode, int mask)
2105 {
2106 int rv;
2107
2108 rv = generic_permission(inode, mask, NULL);
2109 if (rv == 0)
2110 return 0;
2111 if (task_pid(current) == proc_pid(inode))
2112 rv = 0;
2113 return rv;
2114 }
2115
2116 /*
2117 * proc directories can do almost nothing..
2118 */
2119 static const struct inode_operations proc_fd_inode_operations = {
2120 .lookup = proc_lookupfd,
2121 .permission = proc_fd_permission,
2122 .setattr = proc_setattr,
2123 };
2124
2125 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2126 struct dentry *dentry, struct task_struct *task, const void *ptr)
2127 {
2128 unsigned fd = *(unsigned *)ptr;
2129 struct inode *inode;
2130 struct proc_inode *ei;
2131 struct dentry *error = ERR_PTR(-ENOENT);
2132
2133 inode = proc_pid_make_inode(dir->i_sb, task);
2134 if (!inode)
2135 goto out;
2136 ei = PROC_I(inode);
2137 ei->fd = fd;
2138 inode->i_mode = S_IFREG | S_IRUSR;
2139 inode->i_fop = &proc_fdinfo_file_operations;
2140 dentry->d_op = &tid_fd_dentry_operations;
2141 d_add(dentry, inode);
2142 /* Close the race of the process dying before we return the dentry */
2143 if (tid_fd_revalidate(dentry, NULL))
2144 error = NULL;
2145
2146 out:
2147 return error;
2148 }
2149
2150 static struct dentry *proc_lookupfdinfo(struct inode *dir,
2151 struct dentry *dentry,
2152 struct nameidata *nd)
2153 {
2154 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2155 }
2156
2157 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2158 {
2159 return proc_readfd_common(filp, dirent, filldir,
2160 proc_fdinfo_instantiate);
2161 }
2162
2163 static const struct file_operations proc_fdinfo_operations = {
2164 .read = generic_read_dir,
2165 .readdir = proc_readfdinfo,
2166 .llseek = default_llseek,
2167 };
2168
2169 /*
2170 * proc directories can do almost nothing..
2171 */
2172 static const struct inode_operations proc_fdinfo_inode_operations = {
2173 .lookup = proc_lookupfdinfo,
2174 .setattr = proc_setattr,
2175 };
2176
2177
2178 static struct dentry *proc_pident_instantiate(struct inode *dir,
2179 struct dentry *dentry, struct task_struct *task, const void *ptr)
2180 {
2181 const struct pid_entry *p = ptr;
2182 struct inode *inode;
2183 struct proc_inode *ei;
2184 struct dentry *error = ERR_PTR(-ENOENT);
2185
2186 inode = proc_pid_make_inode(dir->i_sb, task);
2187 if (!inode)
2188 goto out;
2189
2190 ei = PROC_I(inode);
2191 inode->i_mode = p->mode;
2192 if (S_ISDIR(inode->i_mode))
2193 inode->i_nlink = 2; /* Use getattr to fix if necessary */
2194 if (p->iop)
2195 inode->i_op = p->iop;
2196 if (p->fop)
2197 inode->i_fop = p->fop;
2198 ei->op = p->op;
2199 dentry->d_op = &pid_dentry_operations;
2200 d_add(dentry, inode);
2201 /* Close the race of the process dying before we return the dentry */
2202 if (pid_revalidate(dentry, NULL))
2203 error = NULL;
2204 out:
2205 return error;
2206 }
2207
2208 static struct dentry *proc_pident_lookup(struct inode *dir,
2209 struct dentry *dentry,
2210 const struct pid_entry *ents,
2211 unsigned int nents)
2212 {
2213 struct dentry *error;
2214 struct task_struct *task = get_proc_task(dir);
2215 const struct pid_entry *p, *last;
2216
2217 error = ERR_PTR(-ENOENT);
2218
2219 if (!task)
2220 goto out_no_task;
2221
2222 /*
2223 * Yes, it does not scale. And it should not. Don't add
2224 * new entries into /proc/<tgid>/ without very good reasons.
2225 */
2226 last = &ents[nents - 1];
2227 for (p = ents; p <= last; p++) {
2228 if (p->len != dentry->d_name.len)
2229 continue;
2230 if (!memcmp(dentry->d_name.name, p->name, p->len))
2231 break;
2232 }
2233 if (p > last)
2234 goto out;
2235
2236 error = proc_pident_instantiate(dir, dentry, task, p);
2237 out:
2238 put_task_struct(task);
2239 out_no_task:
2240 return error;
2241 }
2242
2243 static int proc_pident_fill_cache(struct file *filp, void *dirent,
2244 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2245 {
2246 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2247 proc_pident_instantiate, task, p);
2248 }
2249
2250 static int proc_pident_readdir(struct file *filp,
2251 void *dirent, filldir_t filldir,
2252 const struct pid_entry *ents, unsigned int nents)
2253 {
2254 int i;
2255 struct dentry *dentry = filp->f_path.dentry;
2256 struct inode *inode = dentry->d_inode;
2257 struct task_struct *task = get_proc_task(inode);
2258 const struct pid_entry *p, *last;
2259 ino_t ino;
2260 int ret;
2261
2262 ret = -ENOENT;
2263 if (!task)
2264 goto out_no_task;
2265
2266 ret = 0;
2267 i = filp->f_pos;
2268 switch (i) {
2269 case 0:
2270 ino = inode->i_ino;
2271 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2272 goto out;
2273 i++;
2274 filp->f_pos++;
2275 /* fall through */
2276 case 1:
2277 ino = parent_ino(dentry);
2278 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2279 goto out;
2280 i++;
2281 filp->f_pos++;
2282 /* fall through */
2283 default:
2284 i -= 2;
2285 if (i >= nents) {
2286 ret = 1;
2287 goto out;
2288 }
2289 p = ents + i;
2290 last = &ents[nents - 1];
2291 while (p <= last) {
2292 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2293 goto out;
2294 filp->f_pos++;
2295 p++;
2296 }
2297 }
2298
2299 ret = 1;
2300 out:
2301 put_task_struct(task);
2302 out_no_task:
2303 return ret;
2304 }
2305
2306 #ifdef CONFIG_SECURITY
2307 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2308 size_t count, loff_t *ppos)
2309 {
2310 struct inode * inode = file->f_path.dentry->d_inode;
2311 char *p = NULL;
2312 ssize_t length;
2313 struct task_struct *task = get_proc_task(inode);
2314
2315 if (!task)
2316 return -ESRCH;
2317
2318 length = security_getprocattr(task,
2319 (char*)file->f_path.dentry->d_name.name,
2320 &p);
2321 put_task_struct(task);
2322 if (length > 0)
2323 length = simple_read_from_buffer(buf, count, ppos, p, length);
2324 kfree(p);
2325 return length;
2326 }
2327
2328 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2329 size_t count, loff_t *ppos)
2330 {
2331 struct inode * inode = file->f_path.dentry->d_inode;
2332 char *page;
2333 ssize_t length;
2334 struct task_struct *task = get_proc_task(inode);
2335
2336 length = -ESRCH;
2337 if (!task)
2338 goto out_no_task;
2339 if (count > PAGE_SIZE)
2340 count = PAGE_SIZE;
2341
2342 /* No partial writes. */
2343 length = -EINVAL;
2344 if (*ppos != 0)
2345 goto out;
2346
2347 length = -ENOMEM;
2348 page = (char*)__get_free_page(GFP_TEMPORARY);
2349 if (!page)
2350 goto out;
2351
2352 length = -EFAULT;
2353 if (copy_from_user(page, buf, count))
2354 goto out_free;
2355
2356 /* Guard against adverse ptrace interaction */
2357 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2358 if (length < 0)
2359 goto out_free;
2360
2361 length = security_setprocattr(task,
2362 (char*)file->f_path.dentry->d_name.name,
2363 (void*)page, count);
2364 mutex_unlock(&task->signal->cred_guard_mutex);
2365 out_free:
2366 free_page((unsigned long) page);
2367 out:
2368 put_task_struct(task);
2369 out_no_task:
2370 return length;
2371 }
2372
2373 static const struct file_operations proc_pid_attr_operations = {
2374 .read = proc_pid_attr_read,
2375 .write = proc_pid_attr_write,
2376 .llseek = generic_file_llseek,
2377 };
2378
2379 static const struct pid_entry attr_dir_stuff[] = {
2380 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2381 REG("prev", S_IRUGO, proc_pid_attr_operations),
2382 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2383 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2384 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2385 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2386 };
2387
2388 static int proc_attr_dir_readdir(struct file * filp,
2389 void * dirent, filldir_t filldir)
2390 {
2391 return proc_pident_readdir(filp,dirent,filldir,
2392 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2393 }
2394
2395 static const struct file_operations proc_attr_dir_operations = {
2396 .read = generic_read_dir,
2397 .readdir = proc_attr_dir_readdir,
2398 .llseek = default_llseek,
2399 };
2400
2401 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2402 struct dentry *dentry, struct nameidata *nd)
2403 {
2404 return proc_pident_lookup(dir, dentry,
2405 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2406 }
2407
2408 static const struct inode_operations proc_attr_dir_inode_operations = {
2409 .lookup = proc_attr_dir_lookup,
2410 .getattr = pid_getattr,
2411 .setattr = proc_setattr,
2412 };
2413
2414 #endif
2415
2416 #ifdef CONFIG_ELF_CORE
2417 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2418 size_t count, loff_t *ppos)
2419 {
2420 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2421 struct mm_struct *mm;
2422 char buffer[PROC_NUMBUF];
2423 size_t len;
2424 int ret;
2425
2426 if (!task)
2427 return -ESRCH;
2428
2429 ret = 0;
2430 mm = get_task_mm(task);
2431 if (mm) {
2432 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2433 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2434 MMF_DUMP_FILTER_SHIFT));
2435 mmput(mm);
2436 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2437 }
2438
2439 put_task_struct(task);
2440
2441 return ret;
2442 }
2443
2444 static ssize_t proc_coredump_filter_write(struct file *file,
2445 const char __user *buf,
2446 size_t count,
2447 loff_t *ppos)
2448 {
2449 struct task_struct *task;
2450 struct mm_struct *mm;
2451 char buffer[PROC_NUMBUF], *end;
2452 unsigned int val;
2453 int ret;
2454 int i;
2455 unsigned long mask;
2456
2457 ret = -EFAULT;
2458 memset(buffer, 0, sizeof(buffer));
2459 if (count > sizeof(buffer) - 1)
2460 count = sizeof(buffer) - 1;
2461 if (copy_from_user(buffer, buf, count))
2462 goto out_no_task;
2463
2464 ret = -EINVAL;
2465 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2466 if (*end == '\n')
2467 end++;
2468 if (end - buffer == 0)
2469 goto out_no_task;
2470
2471 ret = -ESRCH;
2472 task = get_proc_task(file->f_dentry->d_inode);
2473 if (!task)
2474 goto out_no_task;
2475
2476 ret = end - buffer;
2477 mm = get_task_mm(task);
2478 if (!mm)
2479 goto out_no_mm;
2480
2481 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2482 if (val & mask)
2483 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2484 else
2485 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2486 }
2487
2488 mmput(mm);
2489 out_no_mm:
2490 put_task_struct(task);
2491 out_no_task:
2492 return ret;
2493 }
2494
2495 static const struct file_operations proc_coredump_filter_operations = {
2496 .read = proc_coredump_filter_read,
2497 .write = proc_coredump_filter_write,
2498 .llseek = generic_file_llseek,
2499 };
2500 #endif
2501
2502 /*
2503 * /proc/self:
2504 */
2505 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2506 int buflen)
2507 {
2508 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2509 pid_t tgid = task_tgid_nr_ns(current, ns);
2510 char tmp[PROC_NUMBUF];
2511 if (!tgid)
2512 return -ENOENT;
2513 sprintf(tmp, "%d", tgid);
2514 return vfs_readlink(dentry,buffer,buflen,tmp);
2515 }
2516
2517 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2518 {
2519 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2520 pid_t tgid = task_tgid_nr_ns(current, ns);
2521 char *name = ERR_PTR(-ENOENT);
2522 if (tgid) {
2523 name = __getname();
2524 if (!name)
2525 name = ERR_PTR(-ENOMEM);
2526 else
2527 sprintf(name, "%d", tgid);
2528 }
2529 nd_set_link(nd, name);
2530 return NULL;
2531 }
2532
2533 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2534 void *cookie)
2535 {
2536 char *s = nd_get_link(nd);
2537 if (!IS_ERR(s))
2538 __putname(s);
2539 }
2540
2541 static const struct inode_operations proc_self_inode_operations = {
2542 .readlink = proc_self_readlink,
2543 .follow_link = proc_self_follow_link,
2544 .put_link = proc_self_put_link,
2545 };
2546
2547 /*
2548 * proc base
2549 *
2550 * These are the directory entries in the root directory of /proc
2551 * that properly belong to the /proc filesystem, as they describe
2552 * describe something that is process related.
2553 */
2554 static const struct pid_entry proc_base_stuff[] = {
2555 NOD("self", S_IFLNK|S_IRWXUGO,
2556 &proc_self_inode_operations, NULL, {}),
2557 };
2558
2559 /*
2560 * Exceptional case: normally we are not allowed to unhash a busy
2561 * directory. In this case, however, we can do it - no aliasing problems
2562 * due to the way we treat inodes.
2563 */
2564 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
2565 {
2566 struct inode *inode = dentry->d_inode;
2567 struct task_struct *task = get_proc_task(inode);
2568 if (task) {
2569 put_task_struct(task);
2570 return 1;
2571 }
2572 d_drop(dentry);
2573 return 0;
2574 }
2575
2576 static const struct dentry_operations proc_base_dentry_operations =
2577 {
2578 .d_revalidate = proc_base_revalidate,
2579 .d_delete = pid_delete_dentry,
2580 };
2581
2582 static struct dentry *proc_base_instantiate(struct inode *dir,
2583 struct dentry *dentry, struct task_struct *task, const void *ptr)
2584 {
2585 const struct pid_entry *p = ptr;
2586 struct inode *inode;
2587 struct proc_inode *ei;
2588 struct dentry *error;
2589
2590 /* Allocate the inode */
2591 error = ERR_PTR(-ENOMEM);
2592 inode = new_inode(dir->i_sb);
2593 if (!inode)
2594 goto out;
2595
2596 /* Initialize the inode */
2597 ei = PROC_I(inode);
2598 inode->i_ino = get_next_ino();
2599 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2600
2601 /*
2602 * grab the reference to the task.
2603 */
2604 ei->pid = get_task_pid(task, PIDTYPE_PID);
2605 if (!ei->pid)
2606 goto out_iput;
2607
2608 inode->i_mode = p->mode;
2609 if (S_ISDIR(inode->i_mode))
2610 inode->i_nlink = 2;
2611 if (S_ISLNK(inode->i_mode))
2612 inode->i_size = 64;
2613 if (p->iop)
2614 inode->i_op = p->iop;
2615 if (p->fop)
2616 inode->i_fop = p->fop;
2617 ei->op = p->op;
2618 dentry->d_op = &proc_base_dentry_operations;
2619 d_add(dentry, inode);
2620 error = NULL;
2621 out:
2622 return error;
2623 out_iput:
2624 iput(inode);
2625 goto out;
2626 }
2627
2628 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2629 {
2630 struct dentry *error;
2631 struct task_struct *task = get_proc_task(dir);
2632 const struct pid_entry *p, *last;
2633
2634 error = ERR_PTR(-ENOENT);
2635
2636 if (!task)
2637 goto out_no_task;
2638
2639 /* Lookup the directory entry */
2640 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2641 for (p = proc_base_stuff; p <= last; p++) {
2642 if (p->len != dentry->d_name.len)
2643 continue;
2644 if (!memcmp(dentry->d_name.name, p->name, p->len))
2645 break;
2646 }
2647 if (p > last)
2648 goto out;
2649
2650 error = proc_base_instantiate(dir, dentry, task, p);
2651
2652 out:
2653 put_task_struct(task);
2654 out_no_task:
2655 return error;
2656 }
2657
2658 static int proc_base_fill_cache(struct file *filp, void *dirent,
2659 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2660 {
2661 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2662 proc_base_instantiate, task, p);
2663 }
2664
2665 #ifdef CONFIG_TASK_IO_ACCOUNTING
2666 static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2667 {
2668 struct task_io_accounting acct = task->ioac;
2669 unsigned long flags;
2670
2671 if (whole && lock_task_sighand(task, &flags)) {
2672 struct task_struct *t = task;
2673
2674 task_io_accounting_add(&acct, &task->signal->ioac);
2675 while_each_thread(task, t)
2676 task_io_accounting_add(&acct, &t->ioac);
2677
2678 unlock_task_sighand(task, &flags);
2679 }
2680 return sprintf(buffer,
2681 "rchar: %llu\n"
2682 "wchar: %llu\n"
2683 "syscr: %llu\n"
2684 "syscw: %llu\n"
2685 "read_bytes: %llu\n"
2686 "write_bytes: %llu\n"
2687 "cancelled_write_bytes: %llu\n",
2688 (unsigned long long)acct.rchar,
2689 (unsigned long long)acct.wchar,
2690 (unsigned long long)acct.syscr,
2691 (unsigned long long)acct.syscw,
2692 (unsigned long long)acct.read_bytes,
2693 (unsigned long long)acct.write_bytes,
2694 (unsigned long long)acct.cancelled_write_bytes);
2695 }
2696
2697 static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2698 {
2699 return do_io_accounting(task, buffer, 0);
2700 }
2701
2702 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2703 {
2704 return do_io_accounting(task, buffer, 1);
2705 }
2706 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2707
2708 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2709 struct pid *pid, struct task_struct *task)
2710 {
2711 seq_printf(m, "%08x\n", task->personality);
2712 return 0;
2713 }
2714
2715 /*
2716 * Thread groups
2717 */
2718 static const struct file_operations proc_task_operations;
2719 static const struct inode_operations proc_task_inode_operations;
2720
2721 static const struct pid_entry tgid_base_stuff[] = {
2722 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2723 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2724 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2725 #ifdef CONFIG_NET
2726 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2727 #endif
2728 REG("environ", S_IRUSR, proc_environ_operations),
2729 INF("auxv", S_IRUSR, proc_pid_auxv),
2730 ONE("status", S_IRUGO, proc_pid_status),
2731 ONE("personality", S_IRUSR, proc_pid_personality),
2732 INF("limits", S_IRUGO, proc_pid_limits),
2733 #ifdef CONFIG_SCHED_DEBUG
2734 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2735 #endif
2736 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2737 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2738 INF("syscall", S_IRUSR, proc_pid_syscall),
2739 #endif
2740 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2741 ONE("stat", S_IRUGO, proc_tgid_stat),
2742 ONE("statm", S_IRUGO, proc_pid_statm),
2743 REG("maps", S_IRUGO, proc_maps_operations),
2744 #ifdef CONFIG_NUMA
2745 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
2746 #endif
2747 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2748 LNK("cwd", proc_cwd_link),
2749 LNK("root", proc_root_link),
2750 LNK("exe", proc_exe_link),
2751 REG("mounts", S_IRUGO, proc_mounts_operations),
2752 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2753 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2754 #ifdef CONFIG_PROC_PAGE_MONITOR
2755 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2756 REG("smaps", S_IRUGO, proc_smaps_operations),
2757 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2758 #endif
2759 #ifdef CONFIG_SECURITY
2760 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2761 #endif
2762 #ifdef CONFIG_KALLSYMS
2763 INF("wchan", S_IRUGO, proc_pid_wchan),
2764 #endif
2765 #ifdef CONFIG_STACKTRACE
2766 ONE("stack", S_IRUSR, proc_pid_stack),
2767 #endif
2768 #ifdef CONFIG_SCHEDSTATS
2769 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2770 #endif
2771 #ifdef CONFIG_LATENCYTOP
2772 REG("latency", S_IRUGO, proc_lstats_operations),
2773 #endif
2774 #ifdef CONFIG_PROC_PID_CPUSET
2775 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2776 #endif
2777 #ifdef CONFIG_CGROUPS
2778 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2779 #endif
2780 INF("oom_score", S_IRUGO, proc_oom_score),
2781 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2782 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2783 #ifdef CONFIG_AUDITSYSCALL
2784 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2785 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2786 #endif
2787 #ifdef CONFIG_FAULT_INJECTION
2788 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2789 #endif
2790 #ifdef CONFIG_ELF_CORE
2791 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2792 #endif
2793 #ifdef CONFIG_TASK_IO_ACCOUNTING
2794 INF("io", S_IRUGO, proc_tgid_io_accounting),
2795 #endif
2796 };
2797
2798 static int proc_tgid_base_readdir(struct file * filp,
2799 void * dirent, filldir_t filldir)
2800 {
2801 return proc_pident_readdir(filp,dirent,filldir,
2802 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2803 }
2804
2805 static const struct file_operations proc_tgid_base_operations = {
2806 .read = generic_read_dir,
2807 .readdir = proc_tgid_base_readdir,
2808 .llseek = default_llseek,
2809 };
2810
2811 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2812 return proc_pident_lookup(dir, dentry,
2813 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2814 }
2815
2816 static const struct inode_operations proc_tgid_base_inode_operations = {
2817 .lookup = proc_tgid_base_lookup,
2818 .getattr = pid_getattr,
2819 .setattr = proc_setattr,
2820 };
2821
2822 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2823 {
2824 struct dentry *dentry, *leader, *dir;
2825 char buf[PROC_NUMBUF];
2826 struct qstr name;
2827
2828 name.name = buf;
2829 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2830 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2831 if (dentry) {
2832 shrink_dcache_parent(dentry);
2833 d_drop(dentry);
2834 dput(dentry);
2835 }
2836
2837 name.name = buf;
2838 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2839 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2840 if (!leader)
2841 goto out;
2842
2843 name.name = "task";
2844 name.len = strlen(name.name);
2845 dir = d_hash_and_lookup(leader, &name);
2846 if (!dir)
2847 goto out_put_leader;
2848
2849 name.name = buf;
2850 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2851 dentry = d_hash_and_lookup(dir, &name);
2852 if (dentry) {
2853 shrink_dcache_parent(dentry);
2854 d_drop(dentry);
2855 dput(dentry);
2856 }
2857
2858 dput(dir);
2859 out_put_leader:
2860 dput(leader);
2861 out:
2862 return;
2863 }
2864
2865 /**
2866 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2867 * @task: task that should be flushed.
2868 *
2869 * When flushing dentries from proc, one needs to flush them from global
2870 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2871 * in. This call is supposed to do all of this job.
2872 *
2873 * Looks in the dcache for
2874 * /proc/@pid
2875 * /proc/@tgid/task/@pid
2876 * if either directory is present flushes it and all of it'ts children
2877 * from the dcache.
2878 *
2879 * It is safe and reasonable to cache /proc entries for a task until
2880 * that task exits. After that they just clog up the dcache with
2881 * useless entries, possibly causing useful dcache entries to be
2882 * flushed instead. This routine is proved to flush those useless
2883 * dcache entries at process exit time.
2884 *
2885 * NOTE: This routine is just an optimization so it does not guarantee
2886 * that no dcache entries will exist at process exit time it
2887 * just makes it very unlikely that any will persist.
2888 */
2889
2890 void proc_flush_task(struct task_struct *task)
2891 {
2892 int i;
2893 struct pid *pid, *tgid;
2894 struct upid *upid;
2895
2896 pid = task_pid(task);
2897 tgid = task_tgid(task);
2898
2899 for (i = 0; i <= pid->level; i++) {
2900 upid = &pid->numbers[i];
2901 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2902 tgid->numbers[i].nr);
2903 }
2904
2905 upid = &pid->numbers[pid->level];
2906 if (upid->nr == 1)
2907 pid_ns_release_proc(upid->ns);
2908 }
2909
2910 static struct dentry *proc_pid_instantiate(struct inode *dir,
2911 struct dentry * dentry,
2912 struct task_struct *task, const void *ptr)
2913 {
2914 struct dentry *error = ERR_PTR(-ENOENT);
2915 struct inode *inode;
2916
2917 inode = proc_pid_make_inode(dir->i_sb, task);
2918 if (!inode)
2919 goto out;
2920
2921 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2922 inode->i_op = &proc_tgid_base_inode_operations;
2923 inode->i_fop = &proc_tgid_base_operations;
2924 inode->i_flags|=S_IMMUTABLE;
2925
2926 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
2927 ARRAY_SIZE(tgid_base_stuff));
2928
2929 dentry->d_op = &pid_dentry_operations;
2930
2931 d_add(dentry, inode);
2932 /* Close the race of the process dying before we return the dentry */
2933 if (pid_revalidate(dentry, NULL))
2934 error = NULL;
2935 out:
2936 return error;
2937 }
2938
2939 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2940 {
2941 struct dentry *result;
2942 struct task_struct *task;
2943 unsigned tgid;
2944 struct pid_namespace *ns;
2945
2946 result = proc_base_lookup(dir, dentry);
2947 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
2948 goto out;
2949
2950 tgid = name_to_int(dentry);
2951 if (tgid == ~0U)
2952 goto out;
2953
2954 ns = dentry->d_sb->s_fs_info;
2955 rcu_read_lock();
2956 task = find_task_by_pid_ns(tgid, ns);
2957 if (task)
2958 get_task_struct(task);
2959 rcu_read_unlock();
2960 if (!task)
2961 goto out;
2962
2963 result = proc_pid_instantiate(dir, dentry, task, NULL);
2964 put_task_struct(task);
2965 out:
2966 return result;
2967 }
2968
2969 /*
2970 * Find the first task with tgid >= tgid
2971 *
2972 */
2973 struct tgid_iter {
2974 unsigned int tgid;
2975 struct task_struct *task;
2976 };
2977 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2978 {
2979 struct pid *pid;
2980
2981 if (iter.task)
2982 put_task_struct(iter.task);
2983 rcu_read_lock();
2984 retry:
2985 iter.task = NULL;
2986 pid = find_ge_pid(iter.tgid, ns);
2987 if (pid) {
2988 iter.tgid = pid_nr_ns(pid, ns);
2989 iter.task = pid_task(pid, PIDTYPE_PID);
2990 /* What we to know is if the pid we have find is the
2991 * pid of a thread_group_leader. Testing for task
2992 * being a thread_group_leader is the obvious thing
2993 * todo but there is a window when it fails, due to
2994 * the pid transfer logic in de_thread.
2995 *
2996 * So we perform the straight forward test of seeing
2997 * if the pid we have found is the pid of a thread
2998 * group leader, and don't worry if the task we have
2999 * found doesn't happen to be a thread group leader.
3000 * As we don't care in the case of readdir.
3001 */
3002 if (!iter.task || !has_group_leader_pid(iter.task)) {
3003 iter.tgid += 1;
3004 goto retry;
3005 }
3006 get_task_struct(iter.task);
3007 }
3008 rcu_read_unlock();
3009 return iter;
3010 }
3011
3012 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
3013
3014 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3015 struct tgid_iter iter)
3016 {
3017 char name[PROC_NUMBUF];
3018 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
3019 return proc_fill_cache(filp, dirent, filldir, name, len,
3020 proc_pid_instantiate, iter.task, NULL);
3021 }
3022
3023 /* for the /proc/ directory itself, after non-process stuff has been done */
3024 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
3025 {
3026 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
3027 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode);
3028 struct tgid_iter iter;
3029 struct pid_namespace *ns;
3030
3031 if (!reaper)
3032 goto out_no_task;
3033
3034 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
3035 const struct pid_entry *p = &proc_base_stuff[nr];
3036 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
3037 goto out;
3038 }
3039
3040 ns = filp->f_dentry->d_sb->s_fs_info;
3041 iter.task = NULL;
3042 iter.tgid = filp->f_pos - TGID_OFFSET;
3043 for (iter = next_tgid(ns, iter);
3044 iter.task;
3045 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3046 filp->f_pos = iter.tgid + TGID_OFFSET;
3047 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
3048 put_task_struct(iter.task);
3049 goto out;
3050 }
3051 }
3052 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3053 out:
3054 put_task_struct(reaper);
3055 out_no_task:
3056 return 0;
3057 }
3058
3059 /*
3060 * Tasks
3061 */
3062 static const struct pid_entry tid_base_stuff[] = {
3063 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3064 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3065 REG("environ", S_IRUSR, proc_environ_operations),
3066 INF("auxv", S_IRUSR, proc_pid_auxv),
3067 ONE("status", S_IRUGO, proc_pid_status),
3068 ONE("personality", S_IRUSR, proc_pid_personality),
3069 INF("limits", S_IRUGO, proc_pid_limits),
3070 #ifdef CONFIG_SCHED_DEBUG
3071 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3072 #endif
3073 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3074 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3075 INF("syscall", S_IRUSR, proc_pid_syscall),
3076 #endif
3077 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3078 ONE("stat", S_IRUGO, proc_tid_stat),
3079 ONE("statm", S_IRUGO, proc_pid_statm),
3080 REG("maps", S_IRUGO, proc_maps_operations),
3081 #ifdef CONFIG_NUMA
3082 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
3083 #endif
3084 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3085 LNK("cwd", proc_cwd_link),
3086 LNK("root", proc_root_link),
3087 LNK("exe", proc_exe_link),
3088 REG("mounts", S_IRUGO, proc_mounts_operations),
3089 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3090 #ifdef CONFIG_PROC_PAGE_MONITOR
3091 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3092 REG("smaps", S_IRUGO, proc_smaps_operations),
3093 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3094 #endif
3095 #ifdef CONFIG_SECURITY
3096 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3097 #endif
3098 #ifdef CONFIG_KALLSYMS
3099 INF("wchan", S_IRUGO, proc_pid_wchan),
3100 #endif
3101 #ifdef CONFIG_STACKTRACE
3102 ONE("stack", S_IRUSR, proc_pid_stack),
3103 #endif
3104 #ifdef CONFIG_SCHEDSTATS
3105 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3106 #endif
3107 #ifdef CONFIG_LATENCYTOP
3108 REG("latency", S_IRUGO, proc_lstats_operations),
3109 #endif
3110 #ifdef CONFIG_PROC_PID_CPUSET
3111 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3112 #endif
3113 #ifdef CONFIG_CGROUPS
3114 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3115 #endif
3116 INF("oom_score", S_IRUGO, proc_oom_score),
3117 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3118 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3119 #ifdef CONFIG_AUDITSYSCALL
3120 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3121 REG("sessionid", S_IRUSR, proc_sessionid_operations),
3122 #endif
3123 #ifdef CONFIG_FAULT_INJECTION
3124 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3125 #endif
3126 #ifdef CONFIG_TASK_IO_ACCOUNTING
3127 INF("io", S_IRUGO, proc_tid_io_accounting),
3128 #endif
3129 };
3130
3131 static int proc_tid_base_readdir(struct file * filp,
3132 void * dirent, filldir_t filldir)
3133 {
3134 return proc_pident_readdir(filp,dirent,filldir,
3135 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3136 }
3137
3138 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3139 return proc_pident_lookup(dir, dentry,
3140 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3141 }
3142
3143 static const struct file_operations proc_tid_base_operations = {
3144 .read = generic_read_dir,
3145 .readdir = proc_tid_base_readdir,
3146 .llseek = default_llseek,
3147 };
3148
3149 static const struct inode_operations proc_tid_base_inode_operations = {
3150 .lookup = proc_tid_base_lookup,
3151 .getattr = pid_getattr,
3152 .setattr = proc_setattr,
3153 };
3154
3155 static struct dentry *proc_task_instantiate(struct inode *dir,
3156 struct dentry *dentry, struct task_struct *task, const void *ptr)
3157 {
3158 struct dentry *error = ERR_PTR(-ENOENT);
3159 struct inode *inode;
3160 inode = proc_pid_make_inode(dir->i_sb, task);
3161
3162 if (!inode)
3163 goto out;
3164 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3165 inode->i_op = &proc_tid_base_inode_operations;
3166 inode->i_fop = &proc_tid_base_operations;
3167 inode->i_flags|=S_IMMUTABLE;
3168
3169 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
3170 ARRAY_SIZE(tid_base_stuff));
3171
3172 dentry->d_op = &pid_dentry_operations;
3173
3174 d_add(dentry, inode);
3175 /* Close the race of the process dying before we return the dentry */
3176 if (pid_revalidate(dentry, NULL))
3177 error = NULL;
3178 out:
3179 return error;
3180 }
3181
3182 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3183 {
3184 struct dentry *result = ERR_PTR(-ENOENT);
3185 struct task_struct *task;
3186 struct task_struct *leader = get_proc_task(dir);
3187 unsigned tid;
3188 struct pid_namespace *ns;
3189
3190 if (!leader)
3191 goto out_no_task;
3192
3193 tid = name_to_int(dentry);
3194 if (tid == ~0U)
3195 goto out;
3196
3197 ns = dentry->d_sb->s_fs_info;
3198 rcu_read_lock();
3199 task = find_task_by_pid_ns(tid, ns);
3200 if (task)
3201 get_task_struct(task);
3202 rcu_read_unlock();
3203 if (!task)
3204 goto out;
3205 if (!same_thread_group(leader, task))
3206 goto out_drop_task;
3207
3208 result = proc_task_instantiate(dir, dentry, task, NULL);
3209 out_drop_task:
3210 put_task_struct(task);
3211 out:
3212 put_task_struct(leader);
3213 out_no_task:
3214 return result;
3215 }
3216
3217 /*
3218 * Find the first tid of a thread group to return to user space.
3219 *
3220 * Usually this is just the thread group leader, but if the users
3221 * buffer was too small or there was a seek into the middle of the
3222 * directory we have more work todo.
3223 *
3224 * In the case of a short read we start with find_task_by_pid.
3225 *
3226 * In the case of a seek we start with the leader and walk nr
3227 * threads past it.
3228 */
3229 static struct task_struct *first_tid(struct task_struct *leader,
3230 int tid, int nr, struct pid_namespace *ns)
3231 {
3232 struct task_struct *pos;
3233
3234 rcu_read_lock();
3235 /* Attempt to start with the pid of a thread */
3236 if (tid && (nr > 0)) {
3237 pos = find_task_by_pid_ns(tid, ns);
3238 if (pos && (pos->group_leader == leader))
3239 goto found;
3240 }
3241
3242 /* If nr exceeds the number of threads there is nothing todo */
3243 pos = NULL;
3244 if (nr && nr >= get_nr_threads(leader))
3245 goto out;
3246
3247 /* If we haven't found our starting place yet start
3248 * with the leader and walk nr threads forward.
3249 */
3250 for (pos = leader; nr > 0; --nr) {
3251 pos = next_thread(pos);
3252 if (pos == leader) {
3253 pos = NULL;
3254 goto out;
3255 }
3256 }
3257 found:
3258 get_task_struct(pos);
3259 out:
3260 rcu_read_unlock();
3261 return pos;
3262 }
3263
3264 /*
3265 * Find the next thread in the thread list.
3266 * Return NULL if there is an error or no next thread.
3267 *
3268 * The reference to the input task_struct is released.
3269 */
3270 static struct task_struct *next_tid(struct task_struct *start)
3271 {
3272 struct task_struct *pos = NULL;
3273 rcu_read_lock();
3274 if (pid_alive(start)) {
3275 pos = next_thread(start);
3276 if (thread_group_leader(pos))
3277 pos = NULL;
3278 else
3279 get_task_struct(pos);
3280 }
3281 rcu_read_unlock();
3282 put_task_struct(start);
3283 return pos;
3284 }
3285
3286 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3287 struct task_struct *task, int tid)
3288 {
3289 char name[PROC_NUMBUF];
3290 int len = snprintf(name, sizeof(name), "%d", tid);
3291 return proc_fill_cache(filp, dirent, filldir, name, len,
3292 proc_task_instantiate, task, NULL);
3293 }
3294
3295 /* for the /proc/TGID/task/ directories */
3296 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3297 {
3298 struct dentry *dentry = filp->f_path.dentry;
3299 struct inode *inode = dentry->d_inode;
3300 struct task_struct *leader = NULL;
3301 struct task_struct *task;
3302 int retval = -ENOENT;
3303 ino_t ino;
3304 int tid;
3305 struct pid_namespace *ns;
3306
3307 task = get_proc_task(inode);
3308 if (!task)
3309 goto out_no_task;
3310 rcu_read_lock();
3311 if (pid_alive(task)) {
3312 leader = task->group_leader;
3313 get_task_struct(leader);
3314 }
3315 rcu_read_unlock();
3316 put_task_struct(task);
3317 if (!leader)
3318 goto out_no_task;
3319 retval = 0;
3320
3321 switch ((unsigned long)filp->f_pos) {
3322 case 0:
3323 ino = inode->i_ino;
3324 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3325 goto out;
3326 filp->f_pos++;
3327 /* fall through */
3328 case 1:
3329 ino = parent_ino(dentry);
3330 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3331 goto out;
3332 filp->f_pos++;
3333 /* fall through */
3334 }
3335
3336 /* f_version caches the tgid value that the last readdir call couldn't
3337 * return. lseek aka telldir automagically resets f_version to 0.
3338 */
3339 ns = filp->f_dentry->d_sb->s_fs_info;
3340 tid = (int)filp->f_version;
3341 filp->f_version = 0;
3342 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3343 task;
3344 task = next_tid(task), filp->f_pos++) {
3345 tid = task_pid_nr_ns(task, ns);
3346 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3347 /* returning this tgid failed, save it as the first
3348 * pid for the next readir call */
3349 filp->f_version = (u64)tid;
3350 put_task_struct(task);
3351 break;
3352 }
3353 }
3354 out:
3355 put_task_struct(leader);
3356 out_no_task:
3357 return retval;
3358 }
3359
3360 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3361 {
3362 struct inode *inode = dentry->d_inode;
3363 struct task_struct *p = get_proc_task(inode);
3364 generic_fillattr(inode, stat);
3365
3366 if (p) {
3367 stat->nlink += get_nr_threads(p);
3368 put_task_struct(p);
3369 }
3370
3371 return 0;
3372 }
3373
3374 static const struct inode_operations proc_task_inode_operations = {
3375 .lookup = proc_task_lookup,
3376 .getattr = proc_task_getattr,
3377 .setattr = proc_setattr,
3378 };
3379
3380 static const struct file_operations proc_task_operations = {
3381 .read = generic_read_dir,
3382 .readdir = proc_task_readdir,
3383 .llseek = default_llseek,
3384 };
linux-next