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nfsd4: typo logical vs bitwise negate for want_mask
[linux-btrfs-devel.git] / fs / proc / base.c
blob5eb02069e1b817730050b7b46304a9244c064bde
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 #ifdef CONFIG_HARDWALL
87 #include <asm/hardwall.h>
88 #endif
89 #include "internal.h"
90
91 /* NOTE:
92 * Implementing inode permission operations in /proc is almost
93 * certainly an error. Permission checks need to happen during
94 * each system call not at open time. The reason is that most of
95 * what we wish to check for permissions in /proc varies at runtime.
96 *
97 * The classic example of a problem is opening file descriptors
98 * in /proc for a task before it execs a suid executable.
99 */
100
101 struct pid_entry {
102 char *name;
103 int len;
104 mode_t mode;
105 const struct inode_operations *iop;
106 const struct file_operations *fop;
107 union proc_op op;
108 };
109
110 #define NOD(NAME, MODE, IOP, FOP, OP) { \
111 .name = (NAME), \
112 .len = sizeof(NAME) - 1, \
113 .mode = MODE, \
114 .iop = IOP, \
115 .fop = FOP, \
116 .op = OP, \
117 }
118
119 #define DIR(NAME, MODE, iops, fops) \
120 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
121 #define LNK(NAME, get_link) \
122 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
123 &proc_pid_link_inode_operations, NULL, \
124 { .proc_get_link = get_link } )
125 #define REG(NAME, MODE, fops) \
126 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
127 #define INF(NAME, MODE, read) \
128 NOD(NAME, (S_IFREG|(MODE)), \
129 NULL, &proc_info_file_operations, \
130 { .proc_read = read } )
131 #define ONE(NAME, MODE, show) \
132 NOD(NAME, (S_IFREG|(MODE)), \
133 NULL, &proc_single_file_operations, \
134 { .proc_show = show } )
135
136 /*
137 * Count the number of hardlinks for the pid_entry table, excluding the .
138 * and .. links.
139 */
140 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
141 unsigned int n)
142 {
143 unsigned int i;
144 unsigned int count;
145
146 count = 0;
147 for (i = 0; i < n; ++i) {
148 if (S_ISDIR(entries[i].mode))
149 ++count;
150 }
151
152 return count;
153 }
154
155 static int get_task_root(struct task_struct *task, struct path *root)
156 {
157 int result = -ENOENT;
158
159 task_lock(task);
160 if (task->fs) {
161 get_fs_root(task->fs, root);
162 result = 0;
163 }
164 task_unlock(task);
165 return result;
166 }
167
168 static int proc_cwd_link(struct inode *inode, struct path *path)
169 {
170 struct task_struct *task = get_proc_task(inode);
171 int result = -ENOENT;
172
173 if (task) {
174 task_lock(task);
175 if (task->fs) {
176 get_fs_pwd(task->fs, path);
177 result = 0;
178 }
179 task_unlock(task);
180 put_task_struct(task);
181 }
182 return result;
183 }
184
185 static int proc_root_link(struct inode *inode, struct path *path)
186 {
187 struct task_struct *task = get_proc_task(inode);
188 int result = -ENOENT;
189
190 if (task) {
191 result = get_task_root(task, path);
192 put_task_struct(task);
193 }
194 return result;
195 }
196
197 static struct mm_struct *__check_mem_permission(struct task_struct *task)
198 {
199 struct mm_struct *mm;
200
201 mm = get_task_mm(task);
202 if (!mm)
203 return ERR_PTR(-EINVAL);
204
205 /*
206 * A task can always look at itself, in case it chooses
207 * to use system calls instead of load instructions.
208 */
209 if (task == current)
210 return mm;
211
212 /*
213 * If current is actively ptrace'ing, and would also be
214 * permitted to freshly attach with ptrace now, permit it.
215 */
216 if (task_is_stopped_or_traced(task)) {
217 int match;
218 rcu_read_lock();
219 match = (ptrace_parent(task) == current);
220 rcu_read_unlock();
221 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
222 return mm;
223 }
224
225 /*
226 * No one else is allowed.
227 */
228 mmput(mm);
229 return ERR_PTR(-EPERM);
230 }
231
232 /*
233 * If current may access user memory in @task return a reference to the
234 * corresponding mm, otherwise ERR_PTR.
235 */
236 static struct mm_struct *check_mem_permission(struct task_struct *task)
237 {
238 struct mm_struct *mm;
239 int err;
240
241 /*
242 * Avoid racing if task exec's as we might get a new mm but validate
243 * against old credentials.
244 */
245 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
246 if (err)
247 return ERR_PTR(err);
248
249 mm = __check_mem_permission(task);
250 mutex_unlock(&task->signal->cred_guard_mutex);
251
252 return mm;
253 }
254
255 struct mm_struct *mm_for_maps(struct task_struct *task)
256 {
257 struct mm_struct *mm;
258 int err;
259
260 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
261 if (err)
262 return ERR_PTR(err);
263
264 mm = get_task_mm(task);
265 if (mm && mm != current->mm &&
266 !ptrace_may_access(task, PTRACE_MODE_READ)) {
267 mmput(mm);
268 mm = ERR_PTR(-EACCES);
269 }
270 mutex_unlock(&task->signal->cred_guard_mutex);
271
272 return mm;
273 }
274
275 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
276 {
277 int res = 0;
278 unsigned int len;
279 struct mm_struct *mm = get_task_mm(task);
280 if (!mm)
281 goto out;
282 if (!mm->arg_end)
283 goto out_mm; /* Shh! No looking before we're done */
284
285 len = mm->arg_end - mm->arg_start;
286
287 if (len > PAGE_SIZE)
288 len = PAGE_SIZE;
289
290 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
291
292 // If the nul at the end of args has been overwritten, then
293 // assume application is using setproctitle(3).
294 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
295 len = strnlen(buffer, res);
296 if (len < res) {
297 res = len;
298 } else {
299 len = mm->env_end - mm->env_start;
300 if (len > PAGE_SIZE - res)
301 len = PAGE_SIZE - res;
302 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
303 res = strnlen(buffer, res);
304 }
305 }
306 out_mm:
307 mmput(mm);
308 out:
309 return res;
310 }
311
312 static int proc_pid_auxv(struct task_struct *task, char *buffer)
313 {
314 struct mm_struct *mm = mm_for_maps(task);
315 int res = PTR_ERR(mm);
316 if (mm && !IS_ERR(mm)) {
317 unsigned int nwords = 0;
318 do {
319 nwords += 2;
320 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
321 res = nwords * sizeof(mm->saved_auxv[0]);
322 if (res > PAGE_SIZE)
323 res = PAGE_SIZE;
324 memcpy(buffer, mm->saved_auxv, res);
325 mmput(mm);
326 }
327 return res;
328 }
329
330
331 #ifdef CONFIG_KALLSYMS
332 /*
333 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
334 * Returns the resolved symbol. If that fails, simply return the address.
335 */
336 static int proc_pid_wchan(struct task_struct *task, char *buffer)
337 {
338 unsigned long wchan;
339 char symname[KSYM_NAME_LEN];
340
341 wchan = get_wchan(task);
342
343 if (lookup_symbol_name(wchan, symname) < 0)
344 if (!ptrace_may_access(task, PTRACE_MODE_READ))
345 return 0;
346 else
347 return sprintf(buffer, "%lu", wchan);
348 else
349 return sprintf(buffer, "%s", symname);
350 }
351 #endif /* CONFIG_KALLSYMS */
352
353 static int lock_trace(struct task_struct *task)
354 {
355 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
356 if (err)
357 return err;
358 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
359 mutex_unlock(&task->signal->cred_guard_mutex);
360 return -EPERM;
361 }
362 return 0;
363 }
364
365 static void unlock_trace(struct task_struct *task)
366 {
367 mutex_unlock(&task->signal->cred_guard_mutex);
368 }
369
370 #ifdef CONFIG_STACKTRACE
371
372 #define MAX_STACK_TRACE_DEPTH 64
373
374 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
375 struct pid *pid, struct task_struct *task)
376 {
377 struct stack_trace trace;
378 unsigned long *entries;
379 int err;
380 int i;
381
382 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
383 if (!entries)
384 return -ENOMEM;
385
386 trace.nr_entries = 0;
387 trace.max_entries = MAX_STACK_TRACE_DEPTH;
388 trace.entries = entries;
389 trace.skip = 0;
390
391 err = lock_trace(task);
392 if (!err) {
393 save_stack_trace_tsk(task, &trace);
394
395 for (i = 0; i < trace.nr_entries; i++) {
396 seq_printf(m, "[<%pK>] %pS\n",
397 (void *)entries[i], (void *)entries[i]);
398 }
399 unlock_trace(task);
400 }
401 kfree(entries);
402
403 return err;
404 }
405 #endif
406
407 #ifdef CONFIG_SCHEDSTATS
408 /*
409 * Provides /proc/PID/schedstat
410 */
411 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
412 {
413 return sprintf(buffer, "%llu %llu %lu\n",
414 (unsigned long long)task->se.sum_exec_runtime,
415 (unsigned long long)task->sched_info.run_delay,
416 task->sched_info.pcount);
417 }
418 #endif
419
420 #ifdef CONFIG_LATENCYTOP
421 static int lstats_show_proc(struct seq_file *m, void *v)
422 {
423 int i;
424 struct inode *inode = m->private;
425 struct task_struct *task = get_proc_task(inode);
426
427 if (!task)
428 return -ESRCH;
429 seq_puts(m, "Latency Top version : v0.1\n");
430 for (i = 0; i < 32; i++) {
431 struct latency_record *lr = &task->latency_record[i];
432 if (lr->backtrace[0]) {
433 int q;
434 seq_printf(m, "%i %li %li",
435 lr->count, lr->time, lr->max);
436 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
437 unsigned long bt = lr->backtrace[q];
438 if (!bt)
439 break;
440 if (bt == ULONG_MAX)
441 break;
442 seq_printf(m, " %ps", (void *)bt);
443 }
444 seq_putc(m, '\n');
445 }
446
447 }
448 put_task_struct(task);
449 return 0;
450 }
451
452 static int lstats_open(struct inode *inode, struct file *file)
453 {
454 return single_open(file, lstats_show_proc, inode);
455 }
456
457 static ssize_t lstats_write(struct file *file, const char __user *buf,
458 size_t count, loff_t *offs)
459 {
460 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
461
462 if (!task)
463 return -ESRCH;
464 clear_all_latency_tracing(task);
465 put_task_struct(task);
466
467 return count;
468 }
469
470 static const struct file_operations proc_lstats_operations = {
471 .open = lstats_open,
472 .read = seq_read,
473 .write = lstats_write,
474 .llseek = seq_lseek,
475 .release = single_release,
476 };
477
478 #endif
479
480 static int proc_oom_score(struct task_struct *task, char *buffer)
481 {
482 unsigned long points = 0;
483
484 read_lock(&tasklist_lock);
485 if (pid_alive(task))
486 points = oom_badness(task, NULL, NULL,
487 totalram_pages + total_swap_pages);
488 read_unlock(&tasklist_lock);
489 return sprintf(buffer, "%lu\n", points);
490 }
491
492 struct limit_names {
493 char *name;
494 char *unit;
495 };
496
497 static const struct limit_names lnames[RLIM_NLIMITS] = {
498 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
499 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
500 [RLIMIT_DATA] = {"Max data size", "bytes"},
501 [RLIMIT_STACK] = {"Max stack size", "bytes"},
502 [RLIMIT_CORE] = {"Max core file size", "bytes"},
503 [RLIMIT_RSS] = {"Max resident set", "bytes"},
504 [RLIMIT_NPROC] = {"Max processes", "processes"},
505 [RLIMIT_NOFILE] = {"Max open files", "files"},
506 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
507 [RLIMIT_AS] = {"Max address space", "bytes"},
508 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
509 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
510 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
511 [RLIMIT_NICE] = {"Max nice priority", NULL},
512 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
513 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
514 };
515
516 /* Display limits for a process */
517 static int proc_pid_limits(struct task_struct *task, char *buffer)
518 {
519 unsigned int i;
520 int count = 0;
521 unsigned long flags;
522 char *bufptr = buffer;
523
524 struct rlimit rlim[RLIM_NLIMITS];
525
526 if (!lock_task_sighand(task, &flags))
527 return 0;
528 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
529 unlock_task_sighand(task, &flags);
530
531 /*
532 * print the file header
533 */
534 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
535 "Limit", "Soft Limit", "Hard Limit", "Units");
536
537 for (i = 0; i < RLIM_NLIMITS; i++) {
538 if (rlim[i].rlim_cur == RLIM_INFINITY)
539 count += sprintf(&bufptr[count], "%-25s %-20s ",
540 lnames[i].name, "unlimited");
541 else
542 count += sprintf(&bufptr[count], "%-25s %-20lu ",
543 lnames[i].name, rlim[i].rlim_cur);
544
545 if (rlim[i].rlim_max == RLIM_INFINITY)
546 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
547 else
548 count += sprintf(&bufptr[count], "%-20lu ",
549 rlim[i].rlim_max);
550
551 if (lnames[i].unit)
552 count += sprintf(&bufptr[count], "%-10s\n",
553 lnames[i].unit);
554 else
555 count += sprintf(&bufptr[count], "\n");
556 }
557
558 return count;
559 }
560
561 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
562 static int proc_pid_syscall(struct task_struct *task, char *buffer)
563 {
564 long nr;
565 unsigned long args[6], sp, pc;
566 int res = lock_trace(task);
567 if (res)
568 return res;
569
570 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
571 res = sprintf(buffer, "running\n");
572 else if (nr < 0)
573 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
574 else
575 res = sprintf(buffer,
576 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
577 nr,
578 args[0], args[1], args[2], args[3], args[4], args[5],
579 sp, pc);
580 unlock_trace(task);
581 return res;
582 }
583 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
584
585 /************************************************************************/
586 /* Here the fs part begins */
587 /************************************************************************/
588
589 /* permission checks */
590 static int proc_fd_access_allowed(struct inode *inode)
591 {
592 struct task_struct *task;
593 int allowed = 0;
594 /* Allow access to a task's file descriptors if it is us or we
595 * may use ptrace attach to the process and find out that
596 * information.
597 */
598 task = get_proc_task(inode);
599 if (task) {
600 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
601 put_task_struct(task);
602 }
603 return allowed;
604 }
605
606 int proc_setattr(struct dentry *dentry, struct iattr *attr)
607 {
608 int error;
609 struct inode *inode = dentry->d_inode;
610
611 if (attr->ia_valid & ATTR_MODE)
612 return -EPERM;
613
614 error = inode_change_ok(inode, attr);
615 if (error)
616 return error;
617
618 if ((attr->ia_valid & ATTR_SIZE) &&
619 attr->ia_size != i_size_read(inode)) {
620 error = vmtruncate(inode, attr->ia_size);
621 if (error)
622 return error;
623 }
624
625 setattr_copy(inode, attr);
626 mark_inode_dirty(inode);
627 return 0;
628 }
629
630 static const struct inode_operations proc_def_inode_operations = {
631 .setattr = proc_setattr,
632 };
633
634 static int mounts_open_common(struct inode *inode, struct file *file,
635 const struct seq_operations *op)
636 {
637 struct task_struct *task = get_proc_task(inode);
638 struct nsproxy *nsp;
639 struct mnt_namespace *ns = NULL;
640 struct path root;
641 struct proc_mounts *p;
642 int ret = -EINVAL;
643
644 if (task) {
645 rcu_read_lock();
646 nsp = task_nsproxy(task);
647 if (nsp) {
648 ns = nsp->mnt_ns;
649 if (ns)
650 get_mnt_ns(ns);
651 }
652 rcu_read_unlock();
653 if (ns && get_task_root(task, &root) == 0)
654 ret = 0;
655 put_task_struct(task);
656 }
657
658 if (!ns)
659 goto err;
660 if (ret)
661 goto err_put_ns;
662
663 ret = -ENOMEM;
664 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
665 if (!p)
666 goto err_put_path;
667
668 file->private_data = &p->m;
669 ret = seq_open(file, op);
670 if (ret)
671 goto err_free;
672
673 p->m.private = p;
674 p->ns = ns;
675 p->root = root;
676 p->m.poll_event = ns->event;
677
678 return 0;
679
680 err_free:
681 kfree(p);
682 err_put_path:
683 path_put(&root);
684 err_put_ns:
685 put_mnt_ns(ns);
686 err:
687 return ret;
688 }
689
690 static int mounts_release(struct inode *inode, struct file *file)
691 {
692 struct proc_mounts *p = file->private_data;
693 path_put(&p->root);
694 put_mnt_ns(p->ns);
695 return seq_release(inode, file);
696 }
697
698 static unsigned mounts_poll(struct file *file, poll_table *wait)
699 {
700 struct proc_mounts *p = file->private_data;
701 unsigned res = POLLIN | POLLRDNORM;
702
703 poll_wait(file, &p->ns->poll, wait);
704 if (mnt_had_events(p))
705 res |= POLLERR | POLLPRI;
706
707 return res;
708 }
709
710 static int mounts_open(struct inode *inode, struct file *file)
711 {
712 return mounts_open_common(inode, file, &mounts_op);
713 }
714
715 static const struct file_operations proc_mounts_operations = {
716 .open = mounts_open,
717 .read = seq_read,
718 .llseek = seq_lseek,
719 .release = mounts_release,
720 .poll = mounts_poll,
721 };
722
723 static int mountinfo_open(struct inode *inode, struct file *file)
724 {
725 return mounts_open_common(inode, file, &mountinfo_op);
726 }
727
728 static const struct file_operations proc_mountinfo_operations = {
729 .open = mountinfo_open,
730 .read = seq_read,
731 .llseek = seq_lseek,
732 .release = mounts_release,
733 .poll = mounts_poll,
734 };
735
736 static int mountstats_open(struct inode *inode, struct file *file)
737 {
738 return mounts_open_common(inode, file, &mountstats_op);
739 }
740
741 static const struct file_operations proc_mountstats_operations = {
742 .open = mountstats_open,
743 .read = seq_read,
744 .llseek = seq_lseek,
745 .release = mounts_release,
746 };
747
748 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
749
750 static ssize_t proc_info_read(struct file * file, char __user * buf,
751 size_t count, loff_t *ppos)
752 {
753 struct inode * inode = file->f_path.dentry->d_inode;
754 unsigned long page;
755 ssize_t length;
756 struct task_struct *task = get_proc_task(inode);
757
758 length = -ESRCH;
759 if (!task)
760 goto out_no_task;
761
762 if (count > PROC_BLOCK_SIZE)
763 count = PROC_BLOCK_SIZE;
764
765 length = -ENOMEM;
766 if (!(page = __get_free_page(GFP_TEMPORARY)))
767 goto out;
768
769 length = PROC_I(inode)->op.proc_read(task, (char*)page);
770
771 if (length >= 0)
772 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
773 free_page(page);
774 out:
775 put_task_struct(task);
776 out_no_task:
777 return length;
778 }
779
780 static const struct file_operations proc_info_file_operations = {
781 .read = proc_info_read,
782 .llseek = generic_file_llseek,
783 };
784
785 static int proc_single_show(struct seq_file *m, void *v)
786 {
787 struct inode *inode = m->private;
788 struct pid_namespace *ns;
789 struct pid *pid;
790 struct task_struct *task;
791 int ret;
792
793 ns = inode->i_sb->s_fs_info;
794 pid = proc_pid(inode);
795 task = get_pid_task(pid, PIDTYPE_PID);
796 if (!task)
797 return -ESRCH;
798
799 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
800
801 put_task_struct(task);
802 return ret;
803 }
804
805 static int proc_single_open(struct inode *inode, struct file *filp)
806 {
807 return single_open(filp, proc_single_show, inode);
808 }
809
810 static const struct file_operations proc_single_file_operations = {
811 .open = proc_single_open,
812 .read = seq_read,
813 .llseek = seq_lseek,
814 .release = single_release,
815 };
816
817 static int mem_open(struct inode* inode, struct file* file)
818 {
819 file->private_data = (void*)((long)current->self_exec_id);
820 /* OK to pass negative loff_t, we can catch out-of-range */
821 file->f_mode |= FMODE_UNSIGNED_OFFSET;
822 return 0;
823 }
824
825 static ssize_t mem_read(struct file * file, char __user * buf,
826 size_t count, loff_t *ppos)
827 {
828 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
829 char *page;
830 unsigned long src = *ppos;
831 int ret = -ESRCH;
832 struct mm_struct *mm;
833
834 if (!task)
835 goto out_no_task;
836
837 ret = -ENOMEM;
838 page = (char *)__get_free_page(GFP_TEMPORARY);
839 if (!page)
840 goto out;
841
842 mm = check_mem_permission(task);
843 ret = PTR_ERR(mm);
844 if (IS_ERR(mm))
845 goto out_free;
846
847 ret = -EIO;
848
849 if (file->private_data != (void*)((long)current->self_exec_id))
850 goto out_put;
851
852 ret = 0;
853
854 while (count > 0) {
855 int this_len, retval;
856
857 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
858 retval = access_remote_vm(mm, src, page, this_len, 0);
859 if (!retval) {
860 if (!ret)
861 ret = -EIO;
862 break;
863 }
864
865 if (copy_to_user(buf, page, retval)) {
866 ret = -EFAULT;
867 break;
868 }
869
870 ret += retval;
871 src += retval;
872 buf += retval;
873 count -= retval;
874 }
875 *ppos = src;
876
877 out_put:
878 mmput(mm);
879 out_free:
880 free_page((unsigned long) page);
881 out:
882 put_task_struct(task);
883 out_no_task:
884 return ret;
885 }
886
887 static ssize_t mem_write(struct file * file, const char __user *buf,
888 size_t count, loff_t *ppos)
889 {
890 int copied;
891 char *page;
892 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
893 unsigned long dst = *ppos;
894 struct mm_struct *mm;
895
896 copied = -ESRCH;
897 if (!task)
898 goto out_no_task;
899
900 copied = -ENOMEM;
901 page = (char *)__get_free_page(GFP_TEMPORARY);
902 if (!page)
903 goto out_task;
904
905 mm = check_mem_permission(task);
906 copied = PTR_ERR(mm);
907 if (IS_ERR(mm))
908 goto out_free;
909
910 copied = -EIO;
911 if (file->private_data != (void *)((long)current->self_exec_id))
912 goto out_mm;
913
914 copied = 0;
915 while (count > 0) {
916 int this_len, retval;
917
918 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
919 if (copy_from_user(page, buf, this_len)) {
920 copied = -EFAULT;
921 break;
922 }
923 retval = access_remote_vm(mm, dst, page, this_len, 1);
924 if (!retval) {
925 if (!copied)
926 copied = -EIO;
927 break;
928 }
929 copied += retval;
930 buf += retval;
931 dst += retval;
932 count -= retval;
933 }
934 *ppos = dst;
935
936 out_mm:
937 mmput(mm);
938 out_free:
939 free_page((unsigned long) page);
940 out_task:
941 put_task_struct(task);
942 out_no_task:
943 return copied;
944 }
945
946 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
947 {
948 switch (orig) {
949 case 0:
950 file->f_pos = offset;
951 break;
952 case 1:
953 file->f_pos += offset;
954 break;
955 default:
956 return -EINVAL;
957 }
958 force_successful_syscall_return();
959 return file->f_pos;
960 }
961
962 static const struct file_operations proc_mem_operations = {
963 .llseek = mem_lseek,
964 .read = mem_read,
965 .write = mem_write,
966 .open = mem_open,
967 };
968
969 static ssize_t environ_read(struct file *file, char __user *buf,
970 size_t count, loff_t *ppos)
971 {
972 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
973 char *page;
974 unsigned long src = *ppos;
975 int ret = -ESRCH;
976 struct mm_struct *mm;
977
978 if (!task)
979 goto out_no_task;
980
981 ret = -ENOMEM;
982 page = (char *)__get_free_page(GFP_TEMPORARY);
983 if (!page)
984 goto out;
985
986
987 mm = mm_for_maps(task);
988 ret = PTR_ERR(mm);
989 if (!mm || IS_ERR(mm))
990 goto out_free;
991
992 ret = 0;
993 while (count > 0) {
994 int this_len, retval, max_len;
995
996 this_len = mm->env_end - (mm->env_start + src);
997
998 if (this_len <= 0)
999 break;
1000
1001 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
1002 this_len = (this_len > max_len) ? max_len : this_len;
1003
1004 retval = access_process_vm(task, (mm->env_start + src),
1005 page, this_len, 0);
1006
1007 if (retval <= 0) {
1008 ret = retval;
1009 break;
1010 }
1011
1012 if (copy_to_user(buf, page, retval)) {
1013 ret = -EFAULT;
1014 break;
1015 }
1016
1017 ret += retval;
1018 src += retval;
1019 buf += retval;
1020 count -= retval;
1021 }
1022 *ppos = src;
1023
1024 mmput(mm);
1025 out_free:
1026 free_page((unsigned long) page);
1027 out:
1028 put_task_struct(task);
1029 out_no_task:
1030 return ret;
1031 }
1032
1033 static const struct file_operations proc_environ_operations = {
1034 .read = environ_read,
1035 .llseek = generic_file_llseek,
1036 };
1037
1038 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
1039 size_t count, loff_t *ppos)
1040 {
1041 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1042 char buffer[PROC_NUMBUF];
1043 size_t len;
1044 int oom_adjust = OOM_DISABLE;
1045 unsigned long flags;
1046
1047 if (!task)
1048 return -ESRCH;
1049
1050 if (lock_task_sighand(task, &flags)) {
1051 oom_adjust = task->signal->oom_adj;
1052 unlock_task_sighand(task, &flags);
1053 }
1054
1055 put_task_struct(task);
1056
1057 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
1058
1059 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1060 }
1061
1062 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
1063 size_t count, loff_t *ppos)
1064 {
1065 struct task_struct *task;
1066 char buffer[PROC_NUMBUF];
1067 int oom_adjust;
1068 unsigned long flags;
1069 int err;
1070
1071 memset(buffer, 0, sizeof(buffer));
1072 if (count > sizeof(buffer) - 1)
1073 count = sizeof(buffer) - 1;
1074 if (copy_from_user(buffer, buf, count)) {
1075 err = -EFAULT;
1076 goto out;
1077 }
1078
1079 err = kstrtoint(strstrip(buffer), 0, &oom_adjust);
1080 if (err)
1081 goto out;
1082 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
1083 oom_adjust != OOM_DISABLE) {
1084 err = -EINVAL;
1085 goto out;
1086 }
1087
1088 task = get_proc_task(file->f_path.dentry->d_inode);
1089 if (!task) {
1090 err = -ESRCH;
1091 goto out;
1092 }
1093
1094 task_lock(task);
1095 if (!task->mm) {
1096 err = -EINVAL;
1097 goto err_task_lock;
1098 }
1099
1100 if (!lock_task_sighand(task, &flags)) {
1101 err = -ESRCH;
1102 goto err_task_lock;
1103 }
1104
1105 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
1106 err = -EACCES;
1107 goto err_sighand;
1108 }
1109
1110 if (oom_adjust != task->signal->oom_adj) {
1111 if (oom_adjust == OOM_DISABLE)
1112 atomic_inc(&task->mm->oom_disable_count);
1113 if (task->signal->oom_adj == OOM_DISABLE)
1114 atomic_dec(&task->mm->oom_disable_count);
1115 }
1116
1117 /*
1118 * Warn that /proc/pid/oom_adj is deprecated, see
1119 * Documentation/feature-removal-schedule.txt.
1120 */
1121 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1122 current->comm, task_pid_nr(current), task_pid_nr(task),
1123 task_pid_nr(task));
1124 task->signal->oom_adj = oom_adjust;
1125 /*
1126 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1127 * value is always attainable.
1128 */
1129 if (task->signal->oom_adj == OOM_ADJUST_MAX)
1130 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
1131 else
1132 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
1133 -OOM_DISABLE;
1134 err_sighand:
1135 unlock_task_sighand(task, &flags);
1136 err_task_lock:
1137 task_unlock(task);
1138 put_task_struct(task);
1139 out:
1140 return err < 0 ? err : count;
1141 }
1142
1143 static const struct file_operations proc_oom_adjust_operations = {
1144 .read = oom_adjust_read,
1145 .write = oom_adjust_write,
1146 .llseek = generic_file_llseek,
1147 };
1148
1149 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1150 size_t count, loff_t *ppos)
1151 {
1152 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1153 char buffer[PROC_NUMBUF];
1154 int oom_score_adj = OOM_SCORE_ADJ_MIN;
1155 unsigned long flags;
1156 size_t len;
1157
1158 if (!task)
1159 return -ESRCH;
1160 if (lock_task_sighand(task, &flags)) {
1161 oom_score_adj = task->signal->oom_score_adj;
1162 unlock_task_sighand(task, &flags);
1163 }
1164 put_task_struct(task);
1165 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
1166 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1167 }
1168
1169 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1170 size_t count, loff_t *ppos)
1171 {
1172 struct task_struct *task;
1173 char buffer[PROC_NUMBUF];
1174 unsigned long flags;
1175 int oom_score_adj;
1176 int err;
1177
1178 memset(buffer, 0, sizeof(buffer));
1179 if (count > sizeof(buffer) - 1)
1180 count = sizeof(buffer) - 1;
1181 if (copy_from_user(buffer, buf, count)) {
1182 err = -EFAULT;
1183 goto out;
1184 }
1185
1186 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1187 if (err)
1188 goto out;
1189 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1190 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1191 err = -EINVAL;
1192 goto out;
1193 }
1194
1195 task = get_proc_task(file->f_path.dentry->d_inode);
1196 if (!task) {
1197 err = -ESRCH;
1198 goto out;
1199 }
1200
1201 task_lock(task);
1202 if (!task->mm) {
1203 err = -EINVAL;
1204 goto err_task_lock;
1205 }
1206
1207 if (!lock_task_sighand(task, &flags)) {
1208 err = -ESRCH;
1209 goto err_task_lock;
1210 }
1211
1212 if (oom_score_adj < task->signal->oom_score_adj_min &&
1213 !capable(CAP_SYS_RESOURCE)) {
1214 err = -EACCES;
1215 goto err_sighand;
1216 }
1217
1218 if (oom_score_adj != task->signal->oom_score_adj) {
1219 if (oom_score_adj == OOM_SCORE_ADJ_MIN)
1220 atomic_inc(&task->mm->oom_disable_count);
1221 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1222 atomic_dec(&task->mm->oom_disable_count);
1223 }
1224 task->signal->oom_score_adj = oom_score_adj;
1225 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1226 task->signal->oom_score_adj_min = oom_score_adj;
1227 /*
1228 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1229 * always attainable.
1230 */
1231 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1232 task->signal->oom_adj = OOM_DISABLE;
1233 else
1234 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1235 OOM_SCORE_ADJ_MAX;
1236 err_sighand:
1237 unlock_task_sighand(task, &flags);
1238 err_task_lock:
1239 task_unlock(task);
1240 put_task_struct(task);
1241 out:
1242 return err < 0 ? err : count;
1243 }
1244
1245 static const struct file_operations proc_oom_score_adj_operations = {
1246 .read = oom_score_adj_read,
1247 .write = oom_score_adj_write,
1248 .llseek = default_llseek,
1249 };
1250
1251 #ifdef CONFIG_AUDITSYSCALL
1252 #define TMPBUFLEN 21
1253 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1254 size_t count, loff_t *ppos)
1255 {
1256 struct inode * inode = file->f_path.dentry->d_inode;
1257 struct task_struct *task = get_proc_task(inode);
1258 ssize_t length;
1259 char tmpbuf[TMPBUFLEN];
1260
1261 if (!task)
1262 return -ESRCH;
1263 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1264 audit_get_loginuid(task));
1265 put_task_struct(task);
1266 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1267 }
1268
1269 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1270 size_t count, loff_t *ppos)
1271 {
1272 struct inode * inode = file->f_path.dentry->d_inode;
1273 char *page, *tmp;
1274 ssize_t length;
1275 uid_t loginuid;
1276
1277 if (!capable(CAP_AUDIT_CONTROL))
1278 return -EPERM;
1279
1280 rcu_read_lock();
1281 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1282 rcu_read_unlock();
1283 return -EPERM;
1284 }
1285 rcu_read_unlock();
1286
1287 if (count >= PAGE_SIZE)
1288 count = PAGE_SIZE - 1;
1289
1290 if (*ppos != 0) {
1291 /* No partial writes. */
1292 return -EINVAL;
1293 }
1294 page = (char*)__get_free_page(GFP_TEMPORARY);
1295 if (!page)
1296 return -ENOMEM;
1297 length = -EFAULT;
1298 if (copy_from_user(page, buf, count))
1299 goto out_free_page;
1300
1301 page[count] = '\0';
1302 loginuid = simple_strtoul(page, &tmp, 10);
1303 if (tmp == page) {
1304 length = -EINVAL;
1305 goto out_free_page;
1306
1307 }
1308 length = audit_set_loginuid(current, loginuid);
1309 if (likely(length == 0))
1310 length = count;
1311
1312 out_free_page:
1313 free_page((unsigned long) page);
1314 return length;
1315 }
1316
1317 static const struct file_operations proc_loginuid_operations = {
1318 .read = proc_loginuid_read,
1319 .write = proc_loginuid_write,
1320 .llseek = generic_file_llseek,
1321 };
1322
1323 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1324 size_t count, loff_t *ppos)
1325 {
1326 struct inode * inode = file->f_path.dentry->d_inode;
1327 struct task_struct *task = get_proc_task(inode);
1328 ssize_t length;
1329 char tmpbuf[TMPBUFLEN];
1330
1331 if (!task)
1332 return -ESRCH;
1333 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1334 audit_get_sessionid(task));
1335 put_task_struct(task);
1336 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1337 }
1338
1339 static const struct file_operations proc_sessionid_operations = {
1340 .read = proc_sessionid_read,
1341 .llseek = generic_file_llseek,
1342 };
1343 #endif
1344
1345 #ifdef CONFIG_FAULT_INJECTION
1346 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1347 size_t count, loff_t *ppos)
1348 {
1349 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1350 char buffer[PROC_NUMBUF];
1351 size_t len;
1352 int make_it_fail;
1353
1354 if (!task)
1355 return -ESRCH;
1356 make_it_fail = task->make_it_fail;
1357 put_task_struct(task);
1358
1359 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1360
1361 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1362 }
1363
1364 static ssize_t proc_fault_inject_write(struct file * file,
1365 const char __user * buf, size_t count, loff_t *ppos)
1366 {
1367 struct task_struct *task;
1368 char buffer[PROC_NUMBUF], *end;
1369 int make_it_fail;
1370
1371 if (!capable(CAP_SYS_RESOURCE))
1372 return -EPERM;
1373 memset(buffer, 0, sizeof(buffer));
1374 if (count > sizeof(buffer) - 1)
1375 count = sizeof(buffer) - 1;
1376 if (copy_from_user(buffer, buf, count))
1377 return -EFAULT;
1378 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1379 if (*end)
1380 return -EINVAL;
1381 task = get_proc_task(file->f_dentry->d_inode);
1382 if (!task)
1383 return -ESRCH;
1384 task->make_it_fail = make_it_fail;
1385 put_task_struct(task);
1386
1387 return count;
1388 }
1389
1390 static const struct file_operations proc_fault_inject_operations = {
1391 .read = proc_fault_inject_read,
1392 .write = proc_fault_inject_write,
1393 .llseek = generic_file_llseek,
1394 };
1395 #endif
1396
1397
1398 #ifdef CONFIG_SCHED_DEBUG
1399 /*
1400 * Print out various scheduling related per-task fields:
1401 */
1402 static int sched_show(struct seq_file *m, void *v)
1403 {
1404 struct inode *inode = m->private;
1405 struct task_struct *p;
1406
1407 p = get_proc_task(inode);
1408 if (!p)
1409 return -ESRCH;
1410 proc_sched_show_task(p, m);
1411
1412 put_task_struct(p);
1413
1414 return 0;
1415 }
1416
1417 static ssize_t
1418 sched_write(struct file *file, const char __user *buf,
1419 size_t count, loff_t *offset)
1420 {
1421 struct inode *inode = file->f_path.dentry->d_inode;
1422 struct task_struct *p;
1423
1424 p = get_proc_task(inode);
1425 if (!p)
1426 return -ESRCH;
1427 proc_sched_set_task(p);
1428
1429 put_task_struct(p);
1430
1431 return count;
1432 }
1433
1434 static int sched_open(struct inode *inode, struct file *filp)
1435 {
1436 return single_open(filp, sched_show, inode);
1437 }
1438
1439 static const struct file_operations proc_pid_sched_operations = {
1440 .open = sched_open,
1441 .read = seq_read,
1442 .write = sched_write,
1443 .llseek = seq_lseek,
1444 .release = single_release,
1445 };
1446
1447 #endif
1448
1449 #ifdef CONFIG_SCHED_AUTOGROUP
1450 /*
1451 * Print out autogroup related information:
1452 */
1453 static int sched_autogroup_show(struct seq_file *m, void *v)
1454 {
1455 struct inode *inode = m->private;
1456 struct task_struct *p;
1457
1458 p = get_proc_task(inode);
1459 if (!p)
1460 return -ESRCH;
1461 proc_sched_autogroup_show_task(p, m);
1462
1463 put_task_struct(p);
1464
1465 return 0;
1466 }
1467
1468 static ssize_t
1469 sched_autogroup_write(struct file *file, const char __user *buf,
1470 size_t count, loff_t *offset)
1471 {
1472 struct inode *inode = file->f_path.dentry->d_inode;
1473 struct task_struct *p;
1474 char buffer[PROC_NUMBUF];
1475 int nice;
1476 int err;
1477
1478 memset(buffer, 0, sizeof(buffer));
1479 if (count > sizeof(buffer) - 1)
1480 count = sizeof(buffer) - 1;
1481 if (copy_from_user(buffer, buf, count))
1482 return -EFAULT;
1483
1484 err = kstrtoint(strstrip(buffer), 0, &nice);
1485 if (err < 0)
1486 return err;
1487
1488 p = get_proc_task(inode);
1489 if (!p)
1490 return -ESRCH;
1491
1492 err = nice;
1493 err = proc_sched_autogroup_set_nice(p, &err);
1494 if (err)
1495 count = err;
1496
1497 put_task_struct(p);
1498
1499 return count;
1500 }
1501
1502 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1503 {
1504 int ret;
1505
1506 ret = single_open(filp, sched_autogroup_show, NULL);
1507 if (!ret) {
1508 struct seq_file *m = filp->private_data;
1509
1510 m->private = inode;
1511 }
1512 return ret;
1513 }
1514
1515 static const struct file_operations proc_pid_sched_autogroup_operations = {
1516 .open = sched_autogroup_open,
1517 .read = seq_read,
1518 .write = sched_autogroup_write,
1519 .llseek = seq_lseek,
1520 .release = single_release,
1521 };
1522
1523 #endif /* CONFIG_SCHED_AUTOGROUP */
1524
1525 static ssize_t comm_write(struct file *file, const char __user *buf,
1526 size_t count, loff_t *offset)
1527 {
1528 struct inode *inode = file->f_path.dentry->d_inode;
1529 struct task_struct *p;
1530 char buffer[TASK_COMM_LEN];
1531
1532 memset(buffer, 0, sizeof(buffer));
1533 if (count > sizeof(buffer) - 1)
1534 count = sizeof(buffer) - 1;
1535 if (copy_from_user(buffer, buf, count))
1536 return -EFAULT;
1537
1538 p = get_proc_task(inode);
1539 if (!p)
1540 return -ESRCH;
1541
1542 if (same_thread_group(current, p))
1543 set_task_comm(p, buffer);
1544 else
1545 count = -EINVAL;
1546
1547 put_task_struct(p);
1548
1549 return count;
1550 }
1551
1552 static int comm_show(struct seq_file *m, void *v)
1553 {
1554 struct inode *inode = m->private;
1555 struct task_struct *p;
1556
1557 p = get_proc_task(inode);
1558 if (!p)
1559 return -ESRCH;
1560
1561 task_lock(p);
1562 seq_printf(m, "%s\n", p->comm);
1563 task_unlock(p);
1564
1565 put_task_struct(p);
1566
1567 return 0;
1568 }
1569
1570 static int comm_open(struct inode *inode, struct file *filp)
1571 {
1572 return single_open(filp, comm_show, inode);
1573 }
1574
1575 static const struct file_operations proc_pid_set_comm_operations = {
1576 .open = comm_open,
1577 .read = seq_read,
1578 .write = comm_write,
1579 .llseek = seq_lseek,
1580 .release = single_release,
1581 };
1582
1583 static int proc_exe_link(struct inode *inode, struct path *exe_path)
1584 {
1585 struct task_struct *task;
1586 struct mm_struct *mm;
1587 struct file *exe_file;
1588
1589 task = get_proc_task(inode);
1590 if (!task)
1591 return -ENOENT;
1592 mm = get_task_mm(task);
1593 put_task_struct(task);
1594 if (!mm)
1595 return -ENOENT;
1596 exe_file = get_mm_exe_file(mm);
1597 mmput(mm);
1598 if (exe_file) {
1599 *exe_path = exe_file->f_path;
1600 path_get(&exe_file->f_path);
1601 fput(exe_file);
1602 return 0;
1603 } else
1604 return -ENOENT;
1605 }
1606
1607 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1608 {
1609 struct inode *inode = dentry->d_inode;
1610 int error = -EACCES;
1611
1612 /* We don't need a base pointer in the /proc filesystem */
1613 path_put(&nd->path);
1614
1615 /* Are we allowed to snoop on the tasks file descriptors? */
1616 if (!proc_fd_access_allowed(inode))
1617 goto out;
1618
1619 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
1620 out:
1621 return ERR_PTR(error);
1622 }
1623
1624 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1625 {
1626 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1627 char *pathname;
1628 int len;
1629
1630 if (!tmp)
1631 return -ENOMEM;
1632
1633 pathname = d_path(path, tmp, PAGE_SIZE);
1634 len = PTR_ERR(pathname);
1635 if (IS_ERR(pathname))
1636 goto out;
1637 len = tmp + PAGE_SIZE - 1 - pathname;
1638
1639 if (len > buflen)
1640 len = buflen;
1641 if (copy_to_user(buffer, pathname, len))
1642 len = -EFAULT;
1643 out:
1644 free_page((unsigned long)tmp);
1645 return len;
1646 }
1647
1648 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1649 {
1650 int error = -EACCES;
1651 struct inode *inode = dentry->d_inode;
1652 struct path path;
1653
1654 /* Are we allowed to snoop on the tasks file descriptors? */
1655 if (!proc_fd_access_allowed(inode))
1656 goto out;
1657
1658 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1659 if (error)
1660 goto out;
1661
1662 error = do_proc_readlink(&path, buffer, buflen);
1663 path_put(&path);
1664 out:
1665 return error;
1666 }
1667
1668 static const struct inode_operations proc_pid_link_inode_operations = {
1669 .readlink = proc_pid_readlink,
1670 .follow_link = proc_pid_follow_link,
1671 .setattr = proc_setattr,
1672 };
1673
1674
1675 /* building an inode */
1676
1677 static int task_dumpable(struct task_struct *task)
1678 {
1679 int dumpable = 0;
1680 struct mm_struct *mm;
1681
1682 task_lock(task);
1683 mm = task->mm;
1684 if (mm)
1685 dumpable = get_dumpable(mm);
1686 task_unlock(task);
1687 if(dumpable == 1)
1688 return 1;
1689 return 0;
1690 }
1691
1692 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1693 {
1694 struct inode * inode;
1695 struct proc_inode *ei;
1696 const struct cred *cred;
1697
1698 /* We need a new inode */
1699
1700 inode = new_inode(sb);
1701 if (!inode)
1702 goto out;
1703
1704 /* Common stuff */
1705 ei = PROC_I(inode);
1706 inode->i_ino = get_next_ino();
1707 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1708 inode->i_op = &proc_def_inode_operations;
1709
1710 /*
1711 * grab the reference to task.
1712 */
1713 ei->pid = get_task_pid(task, PIDTYPE_PID);
1714 if (!ei->pid)
1715 goto out_unlock;
1716
1717 if (task_dumpable(task)) {
1718 rcu_read_lock();
1719 cred = __task_cred(task);
1720 inode->i_uid = cred->euid;
1721 inode->i_gid = cred->egid;
1722 rcu_read_unlock();
1723 }
1724 security_task_to_inode(task, inode);
1725
1726 out:
1727 return inode;
1728
1729 out_unlock:
1730 iput(inode);
1731 return NULL;
1732 }
1733
1734 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1735 {
1736 struct inode *inode = dentry->d_inode;
1737 struct task_struct *task;
1738 const struct cred *cred;
1739
1740 generic_fillattr(inode, stat);
1741
1742 rcu_read_lock();
1743 stat->uid = 0;
1744 stat->gid = 0;
1745 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1746 if (task) {
1747 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1748 task_dumpable(task)) {
1749 cred = __task_cred(task);
1750 stat->uid = cred->euid;
1751 stat->gid = cred->egid;
1752 }
1753 }
1754 rcu_read_unlock();
1755 return 0;
1756 }
1757
1758 /* dentry stuff */
1759
1760 /*
1761 * Exceptional case: normally we are not allowed to unhash a busy
1762 * directory. In this case, however, we can do it - no aliasing problems
1763 * due to the way we treat inodes.
1764 *
1765 * Rewrite the inode's ownerships here because the owning task may have
1766 * performed a setuid(), etc.
1767 *
1768 * Before the /proc/pid/status file was created the only way to read
1769 * the effective uid of a /process was to stat /proc/pid. Reading
1770 * /proc/pid/status is slow enough that procps and other packages
1771 * kept stating /proc/pid. To keep the rules in /proc simple I have
1772 * made this apply to all per process world readable and executable
1773 * directories.
1774 */
1775 int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1776 {
1777 struct inode *inode;
1778 struct task_struct *task;
1779 const struct cred *cred;
1780
1781 if (nd && nd->flags & LOOKUP_RCU)
1782 return -ECHILD;
1783
1784 inode = dentry->d_inode;
1785 task = get_proc_task(inode);
1786
1787 if (task) {
1788 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1789 task_dumpable(task)) {
1790 rcu_read_lock();
1791 cred = __task_cred(task);
1792 inode->i_uid = cred->euid;
1793 inode->i_gid = cred->egid;
1794 rcu_read_unlock();
1795 } else {
1796 inode->i_uid = 0;
1797 inode->i_gid = 0;
1798 }
1799 inode->i_mode &= ~(S_ISUID | S_ISGID);
1800 security_task_to_inode(task, inode);
1801 put_task_struct(task);
1802 return 1;
1803 }
1804 d_drop(dentry);
1805 return 0;
1806 }
1807
1808 static int pid_delete_dentry(const struct dentry * dentry)
1809 {
1810 /* Is the task we represent dead?
1811 * If so, then don't put the dentry on the lru list,
1812 * kill it immediately.
1813 */
1814 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1815 }
1816
1817 const struct dentry_operations pid_dentry_operations =
1818 {
1819 .d_revalidate = pid_revalidate,
1820 .d_delete = pid_delete_dentry,
1821 };
1822
1823 /* Lookups */
1824
1825 /*
1826 * Fill a directory entry.
1827 *
1828 * If possible create the dcache entry and derive our inode number and
1829 * file type from dcache entry.
1830 *
1831 * Since all of the proc inode numbers are dynamically generated, the inode
1832 * numbers do not exist until the inode is cache. This means creating the
1833 * the dcache entry in readdir is necessary to keep the inode numbers
1834 * reported by readdir in sync with the inode numbers reported
1835 * by stat.
1836 */
1837 int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1838 const char *name, int len,
1839 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1840 {
1841 struct dentry *child, *dir = filp->f_path.dentry;
1842 struct inode *inode;
1843 struct qstr qname;
1844 ino_t ino = 0;
1845 unsigned type = DT_UNKNOWN;
1846
1847 qname.name = name;
1848 qname.len = len;
1849 qname.hash = full_name_hash(name, len);
1850
1851 child = d_lookup(dir, &qname);
1852 if (!child) {
1853 struct dentry *new;
1854 new = d_alloc(dir, &qname);
1855 if (new) {
1856 child = instantiate(dir->d_inode, new, task, ptr);
1857 if (child)
1858 dput(new);
1859 else
1860 child = new;
1861 }
1862 }
1863 if (!child || IS_ERR(child) || !child->d_inode)
1864 goto end_instantiate;
1865 inode = child->d_inode;
1866 if (inode) {
1867 ino = inode->i_ino;
1868 type = inode->i_mode >> 12;
1869 }
1870 dput(child);
1871 end_instantiate:
1872 if (!ino)
1873 ino = find_inode_number(dir, &qname);
1874 if (!ino)
1875 ino = 1;
1876 return filldir(dirent, name, len, filp->f_pos, ino, type);
1877 }
1878
1879 static unsigned name_to_int(struct dentry *dentry)
1880 {
1881 const char *name = dentry->d_name.name;
1882 int len = dentry->d_name.len;
1883 unsigned n = 0;
1884
1885 if (len > 1 && *name == '0')
1886 goto out;
1887 while (len-- > 0) {
1888 unsigned c = *name++ - '0';
1889 if (c > 9)
1890 goto out;
1891 if (n >= (~0U-9)/10)
1892 goto out;
1893 n *= 10;
1894 n += c;
1895 }
1896 return n;
1897 out:
1898 return ~0U;
1899 }
1900
1901 #define PROC_FDINFO_MAX 64
1902
1903 static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1904 {
1905 struct task_struct *task = get_proc_task(inode);
1906 struct files_struct *files = NULL;
1907 struct file *file;
1908 int fd = proc_fd(inode);
1909
1910 if (task) {
1911 files = get_files_struct(task);
1912 put_task_struct(task);
1913 }
1914 if (files) {
1915 /*
1916 * We are not taking a ref to the file structure, so we must
1917 * hold ->file_lock.
1918 */
1919 spin_lock(&files->file_lock);
1920 file = fcheck_files(files, fd);
1921 if (file) {
1922 unsigned int f_flags;
1923 struct fdtable *fdt;
1924
1925 fdt = files_fdtable(files);
1926 f_flags = file->f_flags & ~O_CLOEXEC;
1927 if (FD_ISSET(fd, fdt->close_on_exec))
1928 f_flags |= O_CLOEXEC;
1929
1930 if (path) {
1931 *path = file->f_path;
1932 path_get(&file->f_path);
1933 }
1934 if (info)
1935 snprintf(info, PROC_FDINFO_MAX,
1936 "pos:\t%lli\n"
1937 "flags:\t0%o\n",
1938 (long long) file->f_pos,
1939 f_flags);
1940 spin_unlock(&files->file_lock);
1941 put_files_struct(files);
1942 return 0;
1943 }
1944 spin_unlock(&files->file_lock);
1945 put_files_struct(files);
1946 }
1947 return -ENOENT;
1948 }
1949
1950 static int proc_fd_link(struct inode *inode, struct path *path)
1951 {
1952 return proc_fd_info(inode, path, NULL);
1953 }
1954
1955 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1956 {
1957 struct inode *inode;
1958 struct task_struct *task;
1959 int fd;
1960 struct files_struct *files;
1961 const struct cred *cred;
1962
1963 if (nd && nd->flags & LOOKUP_RCU)
1964 return -ECHILD;
1965
1966 inode = dentry->d_inode;
1967 task = get_proc_task(inode);
1968 fd = proc_fd(inode);
1969
1970 if (task) {
1971 files = get_files_struct(task);
1972 if (files) {
1973 rcu_read_lock();
1974 if (fcheck_files(files, fd)) {
1975 rcu_read_unlock();
1976 put_files_struct(files);
1977 if (task_dumpable(task)) {
1978 rcu_read_lock();
1979 cred = __task_cred(task);
1980 inode->i_uid = cred->euid;
1981 inode->i_gid = cred->egid;
1982 rcu_read_unlock();
1983 } else {
1984 inode->i_uid = 0;
1985 inode->i_gid = 0;
1986 }
1987 inode->i_mode &= ~(S_ISUID | S_ISGID);
1988 security_task_to_inode(task, inode);
1989 put_task_struct(task);
1990 return 1;
1991 }
1992 rcu_read_unlock();
1993 put_files_struct(files);
1994 }
1995 put_task_struct(task);
1996 }
1997 d_drop(dentry);
1998 return 0;
1999 }
2000
2001 static const struct dentry_operations tid_fd_dentry_operations =
2002 {
2003 .d_revalidate = tid_fd_revalidate,
2004 .d_delete = pid_delete_dentry,
2005 };
2006
2007 static struct dentry *proc_fd_instantiate(struct inode *dir,
2008 struct dentry *dentry, struct task_struct *task, const void *ptr)
2009 {
2010 unsigned fd = *(const unsigned *)ptr;
2011 struct file *file;
2012 struct files_struct *files;
2013 struct inode *inode;
2014 struct proc_inode *ei;
2015 struct dentry *error = ERR_PTR(-ENOENT);
2016
2017 inode = proc_pid_make_inode(dir->i_sb, task);
2018 if (!inode)
2019 goto out;
2020 ei = PROC_I(inode);
2021 ei->fd = fd;
2022 files = get_files_struct(task);
2023 if (!files)
2024 goto out_iput;
2025 inode->i_mode = S_IFLNK;
2026
2027 /*
2028 * We are not taking a ref to the file structure, so we must
2029 * hold ->file_lock.
2030 */
2031 spin_lock(&files->file_lock);
2032 file = fcheck_files(files, fd);
2033 if (!file)
2034 goto out_unlock;
2035 if (file->f_mode & FMODE_READ)
2036 inode->i_mode |= S_IRUSR | S_IXUSR;
2037 if (file->f_mode & FMODE_WRITE)
2038 inode->i_mode |= S_IWUSR | S_IXUSR;
2039 spin_unlock(&files->file_lock);
2040 put_files_struct(files);
2041
2042 inode->i_op = &proc_pid_link_inode_operations;
2043 inode->i_size = 64;
2044 ei->op.proc_get_link = proc_fd_link;
2045 d_set_d_op(dentry, &tid_fd_dentry_operations);
2046 d_add(dentry, inode);
2047 /* Close the race of the process dying before we return the dentry */
2048 if (tid_fd_revalidate(dentry, NULL))
2049 error = NULL;
2050
2051 out:
2052 return error;
2053 out_unlock:
2054 spin_unlock(&files->file_lock);
2055 put_files_struct(files);
2056 out_iput:
2057 iput(inode);
2058 goto out;
2059 }
2060
2061 static struct dentry *proc_lookupfd_common(struct inode *dir,
2062 struct dentry *dentry,
2063 instantiate_t instantiate)
2064 {
2065 struct task_struct *task = get_proc_task(dir);
2066 unsigned fd = name_to_int(dentry);
2067 struct dentry *result = ERR_PTR(-ENOENT);
2068
2069 if (!task)
2070 goto out_no_task;
2071 if (fd == ~0U)
2072 goto out;
2073
2074 result = instantiate(dir, dentry, task, &fd);
2075 out:
2076 put_task_struct(task);
2077 out_no_task:
2078 return result;
2079 }
2080
2081 static int proc_readfd_common(struct file * filp, void * dirent,
2082 filldir_t filldir, instantiate_t instantiate)
2083 {
2084 struct dentry *dentry = filp->f_path.dentry;
2085 struct inode *inode = dentry->d_inode;
2086 struct task_struct *p = get_proc_task(inode);
2087 unsigned int fd, ino;
2088 int retval;
2089 struct files_struct * files;
2090
2091 retval = -ENOENT;
2092 if (!p)
2093 goto out_no_task;
2094 retval = 0;
2095
2096 fd = filp->f_pos;
2097 switch (fd) {
2098 case 0:
2099 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
2100 goto out;
2101 filp->f_pos++;
2102 case 1:
2103 ino = parent_ino(dentry);
2104 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
2105 goto out;
2106 filp->f_pos++;
2107 default:
2108 files = get_files_struct(p);
2109 if (!files)
2110 goto out;
2111 rcu_read_lock();
2112 for (fd = filp->f_pos-2;
2113 fd < files_fdtable(files)->max_fds;
2114 fd++, filp->f_pos++) {
2115 char name[PROC_NUMBUF];
2116 int len;
2117
2118 if (!fcheck_files(files, fd))
2119 continue;
2120 rcu_read_unlock();
2121
2122 len = snprintf(name, sizeof(name), "%d", fd);
2123 if (proc_fill_cache(filp, dirent, filldir,
2124 name, len, instantiate,
2125 p, &fd) < 0) {
2126 rcu_read_lock();
2127 break;
2128 }
2129 rcu_read_lock();
2130 }
2131 rcu_read_unlock();
2132 put_files_struct(files);
2133 }
2134 out:
2135 put_task_struct(p);
2136 out_no_task:
2137 return retval;
2138 }
2139
2140 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
2141 struct nameidata *nd)
2142 {
2143 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
2144 }
2145
2146 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
2147 {
2148 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
2149 }
2150
2151 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
2152 size_t len, loff_t *ppos)
2153 {
2154 char tmp[PROC_FDINFO_MAX];
2155 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
2156 if (!err)
2157 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
2158 return err;
2159 }
2160
2161 static const struct file_operations proc_fdinfo_file_operations = {
2162 .open = nonseekable_open,
2163 .read = proc_fdinfo_read,
2164 .llseek = no_llseek,
2165 };
2166
2167 static const struct file_operations proc_fd_operations = {
2168 .read = generic_read_dir,
2169 .readdir = proc_readfd,
2170 .llseek = default_llseek,
2171 };
2172
2173 /*
2174 * /proc/pid/fd needs a special permission handler so that a process can still
2175 * access /proc/self/fd after it has executed a setuid().
2176 */
2177 static int proc_fd_permission(struct inode *inode, int mask)
2178 {
2179 int rv = generic_permission(inode, mask);
2180 if (rv == 0)
2181 return 0;
2182 if (task_pid(current) == proc_pid(inode))
2183 rv = 0;
2184 return rv;
2185 }
2186
2187 /*
2188 * proc directories can do almost nothing..
2189 */
2190 static const struct inode_operations proc_fd_inode_operations = {
2191 .lookup = proc_lookupfd,
2192 .permission = proc_fd_permission,
2193 .setattr = proc_setattr,
2194 };
2195
2196 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2197 struct dentry *dentry, struct task_struct *task, const void *ptr)
2198 {
2199 unsigned fd = *(unsigned *)ptr;
2200 struct inode *inode;
2201 struct proc_inode *ei;
2202 struct dentry *error = ERR_PTR(-ENOENT);
2203
2204 inode = proc_pid_make_inode(dir->i_sb, task);
2205 if (!inode)
2206 goto out;
2207 ei = PROC_I(inode);
2208 ei->fd = fd;
2209 inode->i_mode = S_IFREG | S_IRUSR;
2210 inode->i_fop = &proc_fdinfo_file_operations;
2211 d_set_d_op(dentry, &tid_fd_dentry_operations);
2212 d_add(dentry, inode);
2213 /* Close the race of the process dying before we return the dentry */
2214 if (tid_fd_revalidate(dentry, NULL))
2215 error = NULL;
2216
2217 out:
2218 return error;
2219 }
2220
2221 static struct dentry *proc_lookupfdinfo(struct inode *dir,
2222 struct dentry *dentry,
2223 struct nameidata *nd)
2224 {
2225 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2226 }
2227
2228 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2229 {
2230 return proc_readfd_common(filp, dirent, filldir,
2231 proc_fdinfo_instantiate);
2232 }
2233
2234 static const struct file_operations proc_fdinfo_operations = {
2235 .read = generic_read_dir,
2236 .readdir = proc_readfdinfo,
2237 .llseek = default_llseek,
2238 };
2239
2240 /*
2241 * proc directories can do almost nothing..
2242 */
2243 static const struct inode_operations proc_fdinfo_inode_operations = {
2244 .lookup = proc_lookupfdinfo,
2245 .setattr = proc_setattr,
2246 };
2247
2248
2249 static struct dentry *proc_pident_instantiate(struct inode *dir,
2250 struct dentry *dentry, struct task_struct *task, const void *ptr)
2251 {
2252 const struct pid_entry *p = ptr;
2253 struct inode *inode;
2254 struct proc_inode *ei;
2255 struct dentry *error = ERR_PTR(-ENOENT);
2256
2257 inode = proc_pid_make_inode(dir->i_sb, task);
2258 if (!inode)
2259 goto out;
2260
2261 ei = PROC_I(inode);
2262 inode->i_mode = p->mode;
2263 if (S_ISDIR(inode->i_mode))
2264 inode->i_nlink = 2; /* Use getattr to fix if necessary */
2265 if (p->iop)
2266 inode->i_op = p->iop;
2267 if (p->fop)
2268 inode->i_fop = p->fop;
2269 ei->op = p->op;
2270 d_set_d_op(dentry, &pid_dentry_operations);
2271 d_add(dentry, inode);
2272 /* Close the race of the process dying before we return the dentry */
2273 if (pid_revalidate(dentry, NULL))
2274 error = NULL;
2275 out:
2276 return error;
2277 }
2278
2279 static struct dentry *proc_pident_lookup(struct inode *dir,
2280 struct dentry *dentry,
2281 const struct pid_entry *ents,
2282 unsigned int nents)
2283 {
2284 struct dentry *error;
2285 struct task_struct *task = get_proc_task(dir);
2286 const struct pid_entry *p, *last;
2287
2288 error = ERR_PTR(-ENOENT);
2289
2290 if (!task)
2291 goto out_no_task;
2292
2293 /*
2294 * Yes, it does not scale. And it should not. Don't add
2295 * new entries into /proc/<tgid>/ without very good reasons.
2296 */
2297 last = &ents[nents - 1];
2298 for (p = ents; p <= last; p++) {
2299 if (p->len != dentry->d_name.len)
2300 continue;
2301 if (!memcmp(dentry->d_name.name, p->name, p->len))
2302 break;
2303 }
2304 if (p > last)
2305 goto out;
2306
2307 error = proc_pident_instantiate(dir, dentry, task, p);
2308 out:
2309 put_task_struct(task);
2310 out_no_task:
2311 return error;
2312 }
2313
2314 static int proc_pident_fill_cache(struct file *filp, void *dirent,
2315 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2316 {
2317 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2318 proc_pident_instantiate, task, p);
2319 }
2320
2321 static int proc_pident_readdir(struct file *filp,
2322 void *dirent, filldir_t filldir,
2323 const struct pid_entry *ents, unsigned int nents)
2324 {
2325 int i;
2326 struct dentry *dentry = filp->f_path.dentry;
2327 struct inode *inode = dentry->d_inode;
2328 struct task_struct *task = get_proc_task(inode);
2329 const struct pid_entry *p, *last;
2330 ino_t ino;
2331 int ret;
2332
2333 ret = -ENOENT;
2334 if (!task)
2335 goto out_no_task;
2336
2337 ret = 0;
2338 i = filp->f_pos;
2339 switch (i) {
2340 case 0:
2341 ino = inode->i_ino;
2342 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2343 goto out;
2344 i++;
2345 filp->f_pos++;
2346 /* fall through */
2347 case 1:
2348 ino = parent_ino(dentry);
2349 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2350 goto out;
2351 i++;
2352 filp->f_pos++;
2353 /* fall through */
2354 default:
2355 i -= 2;
2356 if (i >= nents) {
2357 ret = 1;
2358 goto out;
2359 }
2360 p = ents + i;
2361 last = &ents[nents - 1];
2362 while (p <= last) {
2363 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2364 goto out;
2365 filp->f_pos++;
2366 p++;
2367 }
2368 }
2369
2370 ret = 1;
2371 out:
2372 put_task_struct(task);
2373 out_no_task:
2374 return ret;
2375 }
2376
2377 #ifdef CONFIG_SECURITY
2378 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2379 size_t count, loff_t *ppos)
2380 {
2381 struct inode * inode = file->f_path.dentry->d_inode;
2382 char *p = NULL;
2383 ssize_t length;
2384 struct task_struct *task = get_proc_task(inode);
2385
2386 if (!task)
2387 return -ESRCH;
2388
2389 length = security_getprocattr(task,
2390 (char*)file->f_path.dentry->d_name.name,
2391 &p);
2392 put_task_struct(task);
2393 if (length > 0)
2394 length = simple_read_from_buffer(buf, count, ppos, p, length);
2395 kfree(p);
2396 return length;
2397 }
2398
2399 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2400 size_t count, loff_t *ppos)
2401 {
2402 struct inode * inode = file->f_path.dentry->d_inode;
2403 char *page;
2404 ssize_t length;
2405 struct task_struct *task = get_proc_task(inode);
2406
2407 length = -ESRCH;
2408 if (!task)
2409 goto out_no_task;
2410 if (count > PAGE_SIZE)
2411 count = PAGE_SIZE;
2412
2413 /* No partial writes. */
2414 length = -EINVAL;
2415 if (*ppos != 0)
2416 goto out;
2417
2418 length = -ENOMEM;
2419 page = (char*)__get_free_page(GFP_TEMPORARY);
2420 if (!page)
2421 goto out;
2422
2423 length = -EFAULT;
2424 if (copy_from_user(page, buf, count))
2425 goto out_free;
2426
2427 /* Guard against adverse ptrace interaction */
2428 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2429 if (length < 0)
2430 goto out_free;
2431
2432 length = security_setprocattr(task,
2433 (char*)file->f_path.dentry->d_name.name,
2434 (void*)page, count);
2435 mutex_unlock(&task->signal->cred_guard_mutex);
2436 out_free:
2437 free_page((unsigned long) page);
2438 out:
2439 put_task_struct(task);
2440 out_no_task:
2441 return length;
2442 }
2443
2444 static const struct file_operations proc_pid_attr_operations = {
2445 .read = proc_pid_attr_read,
2446 .write = proc_pid_attr_write,
2447 .llseek = generic_file_llseek,
2448 };
2449
2450 static const struct pid_entry attr_dir_stuff[] = {
2451 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2452 REG("prev", S_IRUGO, proc_pid_attr_operations),
2453 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2454 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2455 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2456 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2457 };
2458
2459 static int proc_attr_dir_readdir(struct file * filp,
2460 void * dirent, filldir_t filldir)
2461 {
2462 return proc_pident_readdir(filp,dirent,filldir,
2463 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2464 }
2465
2466 static const struct file_operations proc_attr_dir_operations = {
2467 .read = generic_read_dir,
2468 .readdir = proc_attr_dir_readdir,
2469 .llseek = default_llseek,
2470 };
2471
2472 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2473 struct dentry *dentry, struct nameidata *nd)
2474 {
2475 return proc_pident_lookup(dir, dentry,
2476 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2477 }
2478
2479 static const struct inode_operations proc_attr_dir_inode_operations = {
2480 .lookup = proc_attr_dir_lookup,
2481 .getattr = pid_getattr,
2482 .setattr = proc_setattr,
2483 };
2484
2485 #endif
2486
2487 #ifdef CONFIG_ELF_CORE
2488 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2489 size_t count, loff_t *ppos)
2490 {
2491 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2492 struct mm_struct *mm;
2493 char buffer[PROC_NUMBUF];
2494 size_t len;
2495 int ret;
2496
2497 if (!task)
2498 return -ESRCH;
2499
2500 ret = 0;
2501 mm = get_task_mm(task);
2502 if (mm) {
2503 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2504 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2505 MMF_DUMP_FILTER_SHIFT));
2506 mmput(mm);
2507 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2508 }
2509
2510 put_task_struct(task);
2511
2512 return ret;
2513 }
2514
2515 static ssize_t proc_coredump_filter_write(struct file *file,
2516 const char __user *buf,
2517 size_t count,
2518 loff_t *ppos)
2519 {
2520 struct task_struct *task;
2521 struct mm_struct *mm;
2522 char buffer[PROC_NUMBUF], *end;
2523 unsigned int val;
2524 int ret;
2525 int i;
2526 unsigned long mask;
2527
2528 ret = -EFAULT;
2529 memset(buffer, 0, sizeof(buffer));
2530 if (count > sizeof(buffer) - 1)
2531 count = sizeof(buffer) - 1;
2532 if (copy_from_user(buffer, buf, count))
2533 goto out_no_task;
2534
2535 ret = -EINVAL;
2536 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2537 if (*end == '\n')
2538 end++;
2539 if (end - buffer == 0)
2540 goto out_no_task;
2541
2542 ret = -ESRCH;
2543 task = get_proc_task(file->f_dentry->d_inode);
2544 if (!task)
2545 goto out_no_task;
2546
2547 ret = end - buffer;
2548 mm = get_task_mm(task);
2549 if (!mm)
2550 goto out_no_mm;
2551
2552 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2553 if (val & mask)
2554 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2555 else
2556 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2557 }
2558
2559 mmput(mm);
2560 out_no_mm:
2561 put_task_struct(task);
2562 out_no_task:
2563 return ret;
2564 }
2565
2566 static const struct file_operations proc_coredump_filter_operations = {
2567 .read = proc_coredump_filter_read,
2568 .write = proc_coredump_filter_write,
2569 .llseek = generic_file_llseek,
2570 };
2571 #endif
2572
2573 /*
2574 * /proc/self:
2575 */
2576 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2577 int buflen)
2578 {
2579 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2580 pid_t tgid = task_tgid_nr_ns(current, ns);
2581 char tmp[PROC_NUMBUF];
2582 if (!tgid)
2583 return -ENOENT;
2584 sprintf(tmp, "%d", tgid);
2585 return vfs_readlink(dentry,buffer,buflen,tmp);
2586 }
2587
2588 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2589 {
2590 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2591 pid_t tgid = task_tgid_nr_ns(current, ns);
2592 char *name = ERR_PTR(-ENOENT);
2593 if (tgid) {
2594 name = __getname();
2595 if (!name)
2596 name = ERR_PTR(-ENOMEM);
2597 else
2598 sprintf(name, "%d", tgid);
2599 }
2600 nd_set_link(nd, name);
2601 return NULL;
2602 }
2603
2604 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2605 void *cookie)
2606 {
2607 char *s = nd_get_link(nd);
2608 if (!IS_ERR(s))
2609 __putname(s);
2610 }
2611
2612 static const struct inode_operations proc_self_inode_operations = {
2613 .readlink = proc_self_readlink,
2614 .follow_link = proc_self_follow_link,
2615 .put_link = proc_self_put_link,
2616 };
2617
2618 /*
2619 * proc base
2620 *
2621 * These are the directory entries in the root directory of /proc
2622 * that properly belong to the /proc filesystem, as they describe
2623 * describe something that is process related.
2624 */
2625 static const struct pid_entry proc_base_stuff[] = {
2626 NOD("self", S_IFLNK|S_IRWXUGO,
2627 &proc_self_inode_operations, NULL, {}),
2628 };
2629
2630 static struct dentry *proc_base_instantiate(struct inode *dir,
2631 struct dentry *dentry, struct task_struct *task, const void *ptr)
2632 {
2633 const struct pid_entry *p = ptr;
2634 struct inode *inode;
2635 struct proc_inode *ei;
2636 struct dentry *error;
2637
2638 /* Allocate the inode */
2639 error = ERR_PTR(-ENOMEM);
2640 inode = new_inode(dir->i_sb);
2641 if (!inode)
2642 goto out;
2643
2644 /* Initialize the inode */
2645 ei = PROC_I(inode);
2646 inode->i_ino = get_next_ino();
2647 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2648
2649 /*
2650 * grab the reference to the task.
2651 */
2652 ei->pid = get_task_pid(task, PIDTYPE_PID);
2653 if (!ei->pid)
2654 goto out_iput;
2655
2656 inode->i_mode = p->mode;
2657 if (S_ISDIR(inode->i_mode))
2658 inode->i_nlink = 2;
2659 if (S_ISLNK(inode->i_mode))
2660 inode->i_size = 64;
2661 if (p->iop)
2662 inode->i_op = p->iop;
2663 if (p->fop)
2664 inode->i_fop = p->fop;
2665 ei->op = p->op;
2666 d_add(dentry, inode);
2667 error = NULL;
2668 out:
2669 return error;
2670 out_iput:
2671 iput(inode);
2672 goto out;
2673 }
2674
2675 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2676 {
2677 struct dentry *error;
2678 struct task_struct *task = get_proc_task(dir);
2679 const struct pid_entry *p, *last;
2680
2681 error = ERR_PTR(-ENOENT);
2682
2683 if (!task)
2684 goto out_no_task;
2685
2686 /* Lookup the directory entry */
2687 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2688 for (p = proc_base_stuff; p <= last; p++) {
2689 if (p->len != dentry->d_name.len)
2690 continue;
2691 if (!memcmp(dentry->d_name.name, p->name, p->len))
2692 break;
2693 }
2694 if (p > last)
2695 goto out;
2696
2697 error = proc_base_instantiate(dir, dentry, task, p);
2698
2699 out:
2700 put_task_struct(task);
2701 out_no_task:
2702 return error;
2703 }
2704
2705 static int proc_base_fill_cache(struct file *filp, void *dirent,
2706 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2707 {
2708 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2709 proc_base_instantiate, task, p);
2710 }
2711
2712 #ifdef CONFIG_TASK_IO_ACCOUNTING
2713 static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2714 {
2715 struct task_io_accounting acct = task->ioac;
2716 unsigned long flags;
2717 int result;
2718
2719 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2720 if (result)
2721 return result;
2722
2723 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2724 result = -EACCES;
2725 goto out_unlock;
2726 }
2727
2728 if (whole && lock_task_sighand(task, &flags)) {
2729 struct task_struct *t = task;
2730
2731 task_io_accounting_add(&acct, &task->signal->ioac);
2732 while_each_thread(task, t)
2733 task_io_accounting_add(&acct, &t->ioac);
2734
2735 unlock_task_sighand(task, &flags);
2736 }
2737 result = sprintf(buffer,
2738 "rchar: %llu\n"
2739 "wchar: %llu\n"
2740 "syscr: %llu\n"
2741 "syscw: %llu\n"
2742 "read_bytes: %llu\n"
2743 "write_bytes: %llu\n"
2744 "cancelled_write_bytes: %llu\n",
2745 (unsigned long long)acct.rchar,
2746 (unsigned long long)acct.wchar,
2747 (unsigned long long)acct.syscr,
2748 (unsigned long long)acct.syscw,
2749 (unsigned long long)acct.read_bytes,
2750 (unsigned long long)acct.write_bytes,
2751 (unsigned long long)acct.cancelled_write_bytes);
2752 out_unlock:
2753 mutex_unlock(&task->signal->cred_guard_mutex);
2754 return result;
2755 }
2756
2757 static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2758 {
2759 return do_io_accounting(task, buffer, 0);
2760 }
2761
2762 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2763 {
2764 return do_io_accounting(task, buffer, 1);
2765 }
2766 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2767
2768 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2769 struct pid *pid, struct task_struct *task)
2770 {
2771 int err = lock_trace(task);
2772 if (!err) {
2773 seq_printf(m, "%08x\n", task->personality);
2774 unlock_trace(task);
2775 }
2776 return err;
2777 }
2778
2779 /*
2780 * Thread groups
2781 */
2782 static const struct file_operations proc_task_operations;
2783 static const struct inode_operations proc_task_inode_operations;
2784
2785 static const struct pid_entry tgid_base_stuff[] = {
2786 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2787 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2788 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2789 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2790 #ifdef CONFIG_NET
2791 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2792 #endif
2793 REG("environ", S_IRUSR, proc_environ_operations),
2794 INF("auxv", S_IRUSR, proc_pid_auxv),
2795 ONE("status", S_IRUGO, proc_pid_status),
2796 ONE("personality", S_IRUGO, proc_pid_personality),
2797 INF("limits", S_IRUGO, proc_pid_limits),
2798 #ifdef CONFIG_SCHED_DEBUG
2799 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2800 #endif
2801 #ifdef CONFIG_SCHED_AUTOGROUP
2802 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2803 #endif
2804 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2805 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2806 INF("syscall", S_IRUGO, proc_pid_syscall),
2807 #endif
2808 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2809 ONE("stat", S_IRUGO, proc_tgid_stat),
2810 ONE("statm", S_IRUGO, proc_pid_statm),
2811 REG("maps", S_IRUGO, proc_maps_operations),
2812 #ifdef CONFIG_NUMA
2813 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
2814 #endif
2815 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2816 LNK("cwd", proc_cwd_link),
2817 LNK("root", proc_root_link),
2818 LNK("exe", proc_exe_link),
2819 REG("mounts", S_IRUGO, proc_mounts_operations),
2820 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2821 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2822 #ifdef CONFIG_PROC_PAGE_MONITOR
2823 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2824 REG("smaps", S_IRUGO, proc_smaps_operations),
2825 REG("pagemap", S_IRUGO, proc_pagemap_operations),
2826 #endif
2827 #ifdef CONFIG_SECURITY
2828 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2829 #endif
2830 #ifdef CONFIG_KALLSYMS
2831 INF("wchan", S_IRUGO, proc_pid_wchan),
2832 #endif
2833 #ifdef CONFIG_STACKTRACE
2834 ONE("stack", S_IRUGO, proc_pid_stack),
2835 #endif
2836 #ifdef CONFIG_SCHEDSTATS
2837 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2838 #endif
2839 #ifdef CONFIG_LATENCYTOP
2840 REG("latency", S_IRUGO, proc_lstats_operations),
2841 #endif
2842 #ifdef CONFIG_PROC_PID_CPUSET
2843 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2844 #endif
2845 #ifdef CONFIG_CGROUPS
2846 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2847 #endif
2848 INF("oom_score", S_IRUGO, proc_oom_score),
2849 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2850 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2851 #ifdef CONFIG_AUDITSYSCALL
2852 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2853 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2854 #endif
2855 #ifdef CONFIG_FAULT_INJECTION
2856 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2857 #endif
2858 #ifdef CONFIG_ELF_CORE
2859 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2860 #endif
2861 #ifdef CONFIG_TASK_IO_ACCOUNTING
2862 INF("io", S_IRUSR, proc_tgid_io_accounting),
2863 #endif
2864 #ifdef CONFIG_HARDWALL
2865 INF("hardwall", S_IRUGO, proc_pid_hardwall),
2866 #endif
2867 };
2868
2869 static int proc_tgid_base_readdir(struct file * filp,
2870 void * dirent, filldir_t filldir)
2871 {
2872 return proc_pident_readdir(filp,dirent,filldir,
2873 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2874 }
2875
2876 static const struct file_operations proc_tgid_base_operations = {
2877 .read = generic_read_dir,
2878 .readdir = proc_tgid_base_readdir,
2879 .llseek = default_llseek,
2880 };
2881
2882 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2883 return proc_pident_lookup(dir, dentry,
2884 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2885 }
2886
2887 static const struct inode_operations proc_tgid_base_inode_operations = {
2888 .lookup = proc_tgid_base_lookup,
2889 .getattr = pid_getattr,
2890 .setattr = proc_setattr,
2891 };
2892
2893 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2894 {
2895 struct dentry *dentry, *leader, *dir;
2896 char buf[PROC_NUMBUF];
2897 struct qstr name;
2898
2899 name.name = buf;
2900 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2901 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2902 if (dentry) {
2903 shrink_dcache_parent(dentry);
2904 d_drop(dentry);
2905 dput(dentry);
2906 }
2907
2908 name.name = buf;
2909 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2910 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2911 if (!leader)
2912 goto out;
2913
2914 name.name = "task";
2915 name.len = strlen(name.name);
2916 dir = d_hash_and_lookup(leader, &name);
2917 if (!dir)
2918 goto out_put_leader;
2919
2920 name.name = buf;
2921 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2922 dentry = d_hash_and_lookup(dir, &name);
2923 if (dentry) {
2924 shrink_dcache_parent(dentry);
2925 d_drop(dentry);
2926 dput(dentry);
2927 }
2928
2929 dput(dir);
2930 out_put_leader:
2931 dput(leader);
2932 out:
2933 return;
2934 }
2935
2936 /**
2937 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2938 * @task: task that should be flushed.
2939 *
2940 * When flushing dentries from proc, one needs to flush them from global
2941 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2942 * in. This call is supposed to do all of this job.
2943 *
2944 * Looks in the dcache for
2945 * /proc/@pid
2946 * /proc/@tgid/task/@pid
2947 * if either directory is present flushes it and all of it'ts children
2948 * from the dcache.
2949 *
2950 * It is safe and reasonable to cache /proc entries for a task until
2951 * that task exits. After that they just clog up the dcache with
2952 * useless entries, possibly causing useful dcache entries to be
2953 * flushed instead. This routine is proved to flush those useless
2954 * dcache entries at process exit time.
2955 *
2956 * NOTE: This routine is just an optimization so it does not guarantee
2957 * that no dcache entries will exist at process exit time it
2958 * just makes it very unlikely that any will persist.
2959 */
2960
2961 void proc_flush_task(struct task_struct *task)
2962 {
2963 int i;
2964 struct pid *pid, *tgid;
2965 struct upid *upid;
2966
2967 pid = task_pid(task);
2968 tgid = task_tgid(task);
2969
2970 for (i = 0; i <= pid->level; i++) {
2971 upid = &pid->numbers[i];
2972 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2973 tgid->numbers[i].nr);
2974 }
2975
2976 upid = &pid->numbers[pid->level];
2977 if (upid->nr == 1)
2978 pid_ns_release_proc(upid->ns);
2979 }
2980
2981 static struct dentry *proc_pid_instantiate(struct inode *dir,
2982 struct dentry * dentry,
2983 struct task_struct *task, const void *ptr)
2984 {
2985 struct dentry *error = ERR_PTR(-ENOENT);
2986 struct inode *inode;
2987
2988 inode = proc_pid_make_inode(dir->i_sb, task);
2989 if (!inode)
2990 goto out;
2991
2992 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2993 inode->i_op = &proc_tgid_base_inode_operations;
2994 inode->i_fop = &proc_tgid_base_operations;
2995 inode->i_flags|=S_IMMUTABLE;
2996
2997 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
2998 ARRAY_SIZE(tgid_base_stuff));
2999
3000 d_set_d_op(dentry, &pid_dentry_operations);
3001
3002 d_add(dentry, inode);
3003 /* Close the race of the process dying before we return the dentry */
3004 if (pid_revalidate(dentry, NULL))
3005 error = NULL;
3006 out:
3007 return error;
3008 }
3009
3010 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3011 {
3012 struct dentry *result;
3013 struct task_struct *task;
3014 unsigned tgid;
3015 struct pid_namespace *ns;
3016
3017 result = proc_base_lookup(dir, dentry);
3018 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
3019 goto out;
3020
3021 tgid = name_to_int(dentry);
3022 if (tgid == ~0U)
3023 goto out;
3024
3025 ns = dentry->d_sb->s_fs_info;
3026 rcu_read_lock();
3027 task = find_task_by_pid_ns(tgid, ns);
3028 if (task)
3029 get_task_struct(task);
3030 rcu_read_unlock();
3031 if (!task)
3032 goto out;
3033
3034 result = proc_pid_instantiate(dir, dentry, task, NULL);
3035 put_task_struct(task);
3036 out:
3037 return result;
3038 }
3039
3040 /*
3041 * Find the first task with tgid >= tgid
3042 *
3043 */
3044 struct tgid_iter {
3045 unsigned int tgid;
3046 struct task_struct *task;
3047 };
3048 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3049 {
3050 struct pid *pid;
3051
3052 if (iter.task)
3053 put_task_struct(iter.task);
3054 rcu_read_lock();
3055 retry:
3056 iter.task = NULL;
3057 pid = find_ge_pid(iter.tgid, ns);
3058 if (pid) {
3059 iter.tgid = pid_nr_ns(pid, ns);
3060 iter.task = pid_task(pid, PIDTYPE_PID);
3061 /* What we to know is if the pid we have find is the
3062 * pid of a thread_group_leader. Testing for task
3063 * being a thread_group_leader is the obvious thing
3064 * todo but there is a window when it fails, due to
3065 * the pid transfer logic in de_thread.
3066 *
3067 * So we perform the straight forward test of seeing
3068 * if the pid we have found is the pid of a thread
3069 * group leader, and don't worry if the task we have
3070 * found doesn't happen to be a thread group leader.
3071 * As we don't care in the case of readdir.
3072 */
3073 if (!iter.task || !has_group_leader_pid(iter.task)) {
3074 iter.tgid += 1;
3075 goto retry;
3076 }
3077 get_task_struct(iter.task);
3078 }
3079 rcu_read_unlock();
3080 return iter;
3081 }
3082
3083 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
3084
3085 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3086 struct tgid_iter iter)
3087 {
3088 char name[PROC_NUMBUF];
3089 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
3090 return proc_fill_cache(filp, dirent, filldir, name, len,
3091 proc_pid_instantiate, iter.task, NULL);
3092 }
3093
3094 /* for the /proc/ directory itself, after non-process stuff has been done */
3095 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
3096 {
3097 unsigned int nr;
3098 struct task_struct *reaper;
3099 struct tgid_iter iter;
3100 struct pid_namespace *ns;
3101
3102 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
3103 goto out_no_task;
3104 nr = filp->f_pos - FIRST_PROCESS_ENTRY;
3105
3106 reaper = get_proc_task(filp->f_path.dentry->d_inode);
3107 if (!reaper)
3108 goto out_no_task;
3109
3110 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
3111 const struct pid_entry *p = &proc_base_stuff[nr];
3112 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
3113 goto out;
3114 }
3115
3116 ns = filp->f_dentry->d_sb->s_fs_info;
3117 iter.task = NULL;
3118 iter.tgid = filp->f_pos - TGID_OFFSET;
3119 for (iter = next_tgid(ns, iter);
3120 iter.task;
3121 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3122 filp->f_pos = iter.tgid + TGID_OFFSET;
3123 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
3124 put_task_struct(iter.task);
3125 goto out;
3126 }
3127 }
3128 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3129 out:
3130 put_task_struct(reaper);
3131 out_no_task:
3132 return 0;
3133 }
3134
3135 /*
3136 * Tasks
3137 */
3138 static const struct pid_entry tid_base_stuff[] = {
3139 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3140 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3141 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3142 REG("environ", S_IRUSR, proc_environ_operations),
3143 INF("auxv", S_IRUSR, proc_pid_auxv),
3144 ONE("status", S_IRUGO, proc_pid_status),
3145 ONE("personality", S_IRUGO, proc_pid_personality),
3146 INF("limits", S_IRUGO, proc_pid_limits),
3147 #ifdef CONFIG_SCHED_DEBUG
3148 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3149 #endif
3150 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3151 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3152 INF("syscall", S_IRUGO, proc_pid_syscall),
3153 #endif
3154 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3155 ONE("stat", S_IRUGO, proc_tid_stat),
3156 ONE("statm", S_IRUGO, proc_pid_statm),
3157 REG("maps", S_IRUGO, proc_maps_operations),
3158 #ifdef CONFIG_NUMA
3159 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
3160 #endif
3161 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3162 LNK("cwd", proc_cwd_link),
3163 LNK("root", proc_root_link),
3164 LNK("exe", proc_exe_link),
3165 REG("mounts", S_IRUGO, proc_mounts_operations),
3166 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3167 #ifdef CONFIG_PROC_PAGE_MONITOR
3168 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3169 REG("smaps", S_IRUGO, proc_smaps_operations),
3170 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3171 #endif
3172 #ifdef CONFIG_SECURITY
3173 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3174 #endif
3175 #ifdef CONFIG_KALLSYMS
3176 INF("wchan", S_IRUGO, proc_pid_wchan),
3177 #endif
3178 #ifdef CONFIG_STACKTRACE
3179 ONE("stack", S_IRUGO, proc_pid_stack),
3180 #endif
3181 #ifdef CONFIG_SCHEDSTATS
3182 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3183 #endif
3184 #ifdef CONFIG_LATENCYTOP
3185 REG("latency", S_IRUGO, proc_lstats_operations),
3186 #endif
3187 #ifdef CONFIG_PROC_PID_CPUSET
3188 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3189 #endif
3190 #ifdef CONFIG_CGROUPS
3191 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3192 #endif
3193 INF("oom_score", S_IRUGO, proc_oom_score),
3194 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3195 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3196 #ifdef CONFIG_AUDITSYSCALL
3197 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3198 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3199 #endif
3200 #ifdef CONFIG_FAULT_INJECTION
3201 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3202 #endif
3203 #ifdef CONFIG_TASK_IO_ACCOUNTING
3204 INF("io", S_IRUSR, proc_tid_io_accounting),
3205 #endif
3206 #ifdef CONFIG_HARDWALL
3207 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3208 #endif
3209 };
3210
3211 static int proc_tid_base_readdir(struct file * filp,
3212 void * dirent, filldir_t filldir)
3213 {
3214 return proc_pident_readdir(filp,dirent,filldir,
3215 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3216 }
3217
3218 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3219 return proc_pident_lookup(dir, dentry,
3220 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3221 }
3222
3223 static const struct file_operations proc_tid_base_operations = {
3224 .read = generic_read_dir,
3225 .readdir = proc_tid_base_readdir,
3226 .llseek = default_llseek,
3227 };
3228
3229 static const struct inode_operations proc_tid_base_inode_operations = {
3230 .lookup = proc_tid_base_lookup,
3231 .getattr = pid_getattr,
3232 .setattr = proc_setattr,
3233 };
3234
3235 static struct dentry *proc_task_instantiate(struct inode *dir,
3236 struct dentry *dentry, struct task_struct *task, const void *ptr)
3237 {
3238 struct dentry *error = ERR_PTR(-ENOENT);
3239 struct inode *inode;
3240 inode = proc_pid_make_inode(dir->i_sb, task);
3241
3242 if (!inode)
3243 goto out;
3244 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3245 inode->i_op = &proc_tid_base_inode_operations;
3246 inode->i_fop = &proc_tid_base_operations;
3247 inode->i_flags|=S_IMMUTABLE;
3248
3249 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
3250 ARRAY_SIZE(tid_base_stuff));
3251
3252 d_set_d_op(dentry, &pid_dentry_operations);
3253
3254 d_add(dentry, inode);
3255 /* Close the race of the process dying before we return the dentry */
3256 if (pid_revalidate(dentry, NULL))
3257 error = NULL;
3258 out:
3259 return error;
3260 }
3261
3262 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3263 {
3264 struct dentry *result = ERR_PTR(-ENOENT);
3265 struct task_struct *task;
3266 struct task_struct *leader = get_proc_task(dir);
3267 unsigned tid;
3268 struct pid_namespace *ns;
3269
3270 if (!leader)
3271 goto out_no_task;
3272
3273 tid = name_to_int(dentry);
3274 if (tid == ~0U)
3275 goto out;
3276
3277 ns = dentry->d_sb->s_fs_info;
3278 rcu_read_lock();
3279 task = find_task_by_pid_ns(tid, ns);
3280 if (task)
3281 get_task_struct(task);
3282 rcu_read_unlock();
3283 if (!task)
3284 goto out;
3285 if (!same_thread_group(leader, task))
3286 goto out_drop_task;
3287
3288 result = proc_task_instantiate(dir, dentry, task, NULL);
3289 out_drop_task:
3290 put_task_struct(task);
3291 out:
3292 put_task_struct(leader);
3293 out_no_task:
3294 return result;
3295 }
3296
3297 /*
3298 * Find the first tid of a thread group to return to user space.
3299 *
3300 * Usually this is just the thread group leader, but if the users
3301 * buffer was too small or there was a seek into the middle of the
3302 * directory we have more work todo.
3303 *
3304 * In the case of a short read we start with find_task_by_pid.
3305 *
3306 * In the case of a seek we start with the leader and walk nr
3307 * threads past it.
3308 */
3309 static struct task_struct *first_tid(struct task_struct *leader,
3310 int tid, int nr, struct pid_namespace *ns)
3311 {
3312 struct task_struct *pos;
3313
3314 rcu_read_lock();
3315 /* Attempt to start with the pid of a thread */
3316 if (tid && (nr > 0)) {
3317 pos = find_task_by_pid_ns(tid, ns);
3318 if (pos && (pos->group_leader == leader))
3319 goto found;
3320 }
3321
3322 /* If nr exceeds the number of threads there is nothing todo */
3323 pos = NULL;
3324 if (nr && nr >= get_nr_threads(leader))
3325 goto out;
3326
3327 /* If we haven't found our starting place yet start
3328 * with the leader and walk nr threads forward.
3329 */
3330 for (pos = leader; nr > 0; --nr) {
3331 pos = next_thread(pos);
3332 if (pos == leader) {
3333 pos = NULL;
3334 goto out;
3335 }
3336 }
3337 found:
3338 get_task_struct(pos);
3339 out:
3340 rcu_read_unlock();
3341 return pos;
3342 }
3343
3344 /*
3345 * Find the next thread in the thread list.
3346 * Return NULL if there is an error or no next thread.
3347 *
3348 * The reference to the input task_struct is released.
3349 */
3350 static struct task_struct *next_tid(struct task_struct *start)
3351 {
3352 struct task_struct *pos = NULL;
3353 rcu_read_lock();
3354 if (pid_alive(start)) {
3355 pos = next_thread(start);
3356 if (thread_group_leader(pos))
3357 pos = NULL;
3358 else
3359 get_task_struct(pos);
3360 }
3361 rcu_read_unlock();
3362 put_task_struct(start);
3363 return pos;
3364 }
3365
3366 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3367 struct task_struct *task, int tid)
3368 {
3369 char name[PROC_NUMBUF];
3370 int len = snprintf(name, sizeof(name), "%d", tid);
3371 return proc_fill_cache(filp, dirent, filldir, name, len,
3372 proc_task_instantiate, task, NULL);
3373 }
3374
3375 /* for the /proc/TGID/task/ directories */
3376 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3377 {
3378 struct dentry *dentry = filp->f_path.dentry;
3379 struct inode *inode = dentry->d_inode;
3380 struct task_struct *leader = NULL;
3381 struct task_struct *task;
3382 int retval = -ENOENT;
3383 ino_t ino;
3384 int tid;
3385 struct pid_namespace *ns;
3386
3387 task = get_proc_task(inode);
3388 if (!task)
3389 goto out_no_task;
3390 rcu_read_lock();
3391 if (pid_alive(task)) {
3392 leader = task->group_leader;
3393 get_task_struct(leader);
3394 }
3395 rcu_read_unlock();
3396 put_task_struct(task);
3397 if (!leader)
3398 goto out_no_task;
3399 retval = 0;
3400
3401 switch ((unsigned long)filp->f_pos) {
3402 case 0:
3403 ino = inode->i_ino;
3404 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3405 goto out;
3406 filp->f_pos++;
3407 /* fall through */
3408 case 1:
3409 ino = parent_ino(dentry);
3410 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3411 goto out;
3412 filp->f_pos++;
3413 /* fall through */
3414 }
3415
3416 /* f_version caches the tgid value that the last readdir call couldn't
3417 * return. lseek aka telldir automagically resets f_version to 0.
3418 */
3419 ns = filp->f_dentry->d_sb->s_fs_info;
3420 tid = (int)filp->f_version;
3421 filp->f_version = 0;
3422 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3423 task;
3424 task = next_tid(task), filp->f_pos++) {
3425 tid = task_pid_nr_ns(task, ns);
3426 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3427 /* returning this tgid failed, save it as the first
3428 * pid for the next readir call */
3429 filp->f_version = (u64)tid;
3430 put_task_struct(task);
3431 break;
3432 }
3433 }
3434 out:
3435 put_task_struct(leader);
3436 out_no_task:
3437 return retval;
3438 }
3439
3440 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3441 {
3442 struct inode *inode = dentry->d_inode;
3443 struct task_struct *p = get_proc_task(inode);
3444 generic_fillattr(inode, stat);
3445
3446 if (p) {
3447 stat->nlink += get_nr_threads(p);
3448 put_task_struct(p);
3449 }
3450
3451 return 0;
3452 }
3453
3454 static const struct inode_operations proc_task_inode_operations = {
3455 .lookup = proc_task_lookup,
3456 .getattr = proc_task_getattr,
3457 .setattr = proc_setattr,
3458 };
3459
3460 static const struct file_operations proc_task_operations = {
3461 .read = generic_read_dir,
3462 .readdir = proc_task_readdir,
3463 .llseek = default_llseek,
3464 };
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