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