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