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Linux 2.6.35-rc2
[linux/fpc-iii.git] / fs / proc / base.c
blobacb7ef80ea4fcc4987b0b2159f70d599f659c31e
1 /*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
48 */
49
50 #include <asm/uaccess.h>
51
52 #include <linux/errno.h>
53 #include <linux/time.h>
54 #include <linux/proc_fs.h>
55 #include <linux/stat.h>
56 #include <linux/task_io_accounting_ops.h>
57 #include <linux/init.h>
58 #include <linux/capability.h>
59 #include <linux/file.h>
60 #include <linux/fdtable.h>
61 #include <linux/string.h>
62 #include <linux/seq_file.h>
63 #include <linux/namei.h>
64 #include <linux/mnt_namespace.h>
65 #include <linux/mm.h>
66 #include <linux/rcupdate.h>
67 #include <linux/kallsyms.h>
68 #include <linux/stacktrace.h>
69 #include <linux/resource.h>
70 #include <linux/module.h>
71 #include <linux/mount.h>
72 #include <linux/security.h>
73 #include <linux/ptrace.h>
74 #include <linux/tracehook.h>
75 #include <linux/cgroup.h>
76 #include <linux/cpuset.h>
77 #include <linux/audit.h>
78 #include <linux/poll.h>
79 #include <linux/nsproxy.h>
80 #include <linux/oom.h>
81 #include <linux/elf.h>
82 #include <linux/pid_namespace.h>
83 #include <linux/fs_struct.h>
84 #include <linux/slab.h>
85 #include "internal.h"
86
87 /* NOTE:
88 * Implementing inode permission operations in /proc is almost
89 * certainly an error. Permission checks need to happen during
90 * each system call not at open time. The reason is that most of
91 * what we wish to check for permissions in /proc varies at runtime.
92 *
93 * The classic example of a problem is opening file descriptors
94 * in /proc for a task before it execs a suid executable.
95 */
96
97 struct pid_entry {
98 char *name;
99 int len;
100 mode_t mode;
101 const struct inode_operations *iop;
102 const struct file_operations *fop;
103 union proc_op op;
104 };
105
106 #define NOD(NAME, MODE, IOP, FOP, OP) { \
107 .name = (NAME), \
108 .len = sizeof(NAME) - 1, \
109 .mode = MODE, \
110 .iop = IOP, \
111 .fop = FOP, \
112 .op = OP, \
113 }
114
115 #define DIR(NAME, MODE, iops, fops) \
116 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
117 #define LNK(NAME, get_link) \
118 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
119 &proc_pid_link_inode_operations, NULL, \
120 { .proc_get_link = get_link } )
121 #define REG(NAME, MODE, fops) \
122 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
123 #define INF(NAME, MODE, read) \
124 NOD(NAME, (S_IFREG|(MODE)), \
125 NULL, &proc_info_file_operations, \
126 { .proc_read = read } )
127 #define ONE(NAME, MODE, show) \
128 NOD(NAME, (S_IFREG|(MODE)), \
129 NULL, &proc_single_file_operations, \
130 { .proc_show = show } )
131
132 /*
133 * Count the number of hardlinks for the pid_entry table, excluding the .
134 * and .. links.
135 */
136 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
137 unsigned int n)
138 {
139 unsigned int i;
140 unsigned int count;
141
142 count = 0;
143 for (i = 0; i < n; ++i) {
144 if (S_ISDIR(entries[i].mode))
145 ++count;
146 }
147
148 return count;
149 }
150
151 static int get_fs_path(struct task_struct *task, struct path *path, bool root)
152 {
153 struct fs_struct *fs;
154 int result = -ENOENT;
155
156 task_lock(task);
157 fs = task->fs;
158 if (fs) {
159 read_lock(&fs->lock);
160 *path = root ? fs->root : fs->pwd;
161 path_get(path);
162 read_unlock(&fs->lock);
163 result = 0;
164 }
165 task_unlock(task);
166 return result;
167 }
168
169 static int proc_cwd_link(struct inode *inode, struct path *path)
170 {
171 struct task_struct *task = get_proc_task(inode);
172 int result = -ENOENT;
173
174 if (task) {
175 result = get_fs_path(task, path, 0);
176 put_task_struct(task);
177 }
178 return result;
179 }
180
181 static int proc_root_link(struct inode *inode, struct path *path)
182 {
183 struct task_struct *task = get_proc_task(inode);
184 int result = -ENOENT;
185
186 if (task) {
187 result = get_fs_path(task, path, 1);
188 put_task_struct(task);
189 }
190 return result;
191 }
192
193 /*
194 * Return zero if current may access user memory in @task, -error if not.
195 */
196 static int check_mem_permission(struct task_struct *task)
197 {
198 /*
199 * A task can always look at itself, in case it chooses
200 * to use system calls instead of load instructions.
201 */
202 if (task == current)
203 return 0;
204
205 /*
206 * If current is actively ptrace'ing, and would also be
207 * permitted to freshly attach with ptrace now, permit it.
208 */
209 if (task_is_stopped_or_traced(task)) {
210 int match;
211 rcu_read_lock();
212 match = (tracehook_tracer_task(task) == current);
213 rcu_read_unlock();
214 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
215 return 0;
216 }
217
218 /*
219 * Noone else is allowed.
220 */
221 return -EPERM;
222 }
223
224 struct mm_struct *mm_for_maps(struct task_struct *task)
225 {
226 struct mm_struct *mm;
227
228 if (mutex_lock_killable(&task->cred_guard_mutex))
229 return NULL;
230
231 mm = get_task_mm(task);
232 if (mm && mm != current->mm &&
233 !ptrace_may_access(task, PTRACE_MODE_READ)) {
234 mmput(mm);
235 mm = NULL;
236 }
237 mutex_unlock(&task->cred_guard_mutex);
238
239 return mm;
240 }
241
242 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
243 {
244 int res = 0;
245 unsigned int len;
246 struct mm_struct *mm = get_task_mm(task);
247 if (!mm)
248 goto out;
249 if (!mm->arg_end)
250 goto out_mm; /* Shh! No looking before we're done */
251
252 len = mm->arg_end - mm->arg_start;
253
254 if (len > PAGE_SIZE)
255 len = PAGE_SIZE;
256
257 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
258
259 // If the nul at the end of args has been overwritten, then
260 // assume application is using setproctitle(3).
261 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
262 len = strnlen(buffer, res);
263 if (len < res) {
264 res = len;
265 } else {
266 len = mm->env_end - mm->env_start;
267 if (len > PAGE_SIZE - res)
268 len = PAGE_SIZE - res;
269 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
270 res = strnlen(buffer, res);
271 }
272 }
273 out_mm:
274 mmput(mm);
275 out:
276 return res;
277 }
278
279 static int proc_pid_auxv(struct task_struct *task, char *buffer)
280 {
281 int res = 0;
282 struct mm_struct *mm = get_task_mm(task);
283 if (mm) {
284 unsigned int nwords = 0;
285 do {
286 nwords += 2;
287 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
288 res = nwords * sizeof(mm->saved_auxv[0]);
289 if (res > PAGE_SIZE)
290 res = PAGE_SIZE;
291 memcpy(buffer, mm->saved_auxv, res);
292 mmput(mm);
293 }
294 return res;
295 }
296
297
298 #ifdef CONFIG_KALLSYMS
299 /*
300 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
301 * Returns the resolved symbol. If that fails, simply return the address.
302 */
303 static int proc_pid_wchan(struct task_struct *task, char *buffer)
304 {
305 unsigned long wchan;
306 char symname[KSYM_NAME_LEN];
307
308 wchan = get_wchan(task);
309
310 if (lookup_symbol_name(wchan, symname) < 0)
311 if (!ptrace_may_access(task, PTRACE_MODE_READ))
312 return 0;
313 else
314 return sprintf(buffer, "%lu", wchan);
315 else
316 return sprintf(buffer, "%s", symname);
317 }
318 #endif /* CONFIG_KALLSYMS */
319
320 #ifdef CONFIG_STACKTRACE
321
322 #define MAX_STACK_TRACE_DEPTH 64
323
324 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
325 struct pid *pid, struct task_struct *task)
326 {
327 struct stack_trace trace;
328 unsigned long *entries;
329 int i;
330
331 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
332 if (!entries)
333 return -ENOMEM;
334
335 trace.nr_entries = 0;
336 trace.max_entries = MAX_STACK_TRACE_DEPTH;
337 trace.entries = entries;
338 trace.skip = 0;
339 save_stack_trace_tsk(task, &trace);
340
341 for (i = 0; i < trace.nr_entries; i++) {
342 seq_printf(m, "[<%p>] %pS\n",
343 (void *)entries[i], (void *)entries[i]);
344 }
345 kfree(entries);
346
347 return 0;
348 }
349 #endif
350
351 #ifdef CONFIG_SCHEDSTATS
352 /*
353 * Provides /proc/PID/schedstat
354 */
355 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
356 {
357 return sprintf(buffer, "%llu %llu %lu\n",
358 (unsigned long long)task->se.sum_exec_runtime,
359 (unsigned long long)task->sched_info.run_delay,
360 task->sched_info.pcount);
361 }
362 #endif
363
364 #ifdef CONFIG_LATENCYTOP
365 static int lstats_show_proc(struct seq_file *m, void *v)
366 {
367 int i;
368 struct inode *inode = m->private;
369 struct task_struct *task = get_proc_task(inode);
370
371 if (!task)
372 return -ESRCH;
373 seq_puts(m, "Latency Top version : v0.1\n");
374 for (i = 0; i < 32; i++) {
375 if (task->latency_record[i].backtrace[0]) {
376 int q;
377 seq_printf(m, "%i %li %li ",
378 task->latency_record[i].count,
379 task->latency_record[i].time,
380 task->latency_record[i].max);
381 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
382 char sym[KSYM_SYMBOL_LEN];
383 char *c;
384 if (!task->latency_record[i].backtrace[q])
385 break;
386 if (task->latency_record[i].backtrace[q] == ULONG_MAX)
387 break;
388 sprint_symbol(sym, task->latency_record[i].backtrace[q]);
389 c = strchr(sym, '+');
390 if (c)
391 *c = 0;
392 seq_printf(m, "%s ", sym);
393 }
394 seq_printf(m, "\n");
395 }
396
397 }
398 put_task_struct(task);
399 return 0;
400 }
401
402 static int lstats_open(struct inode *inode, struct file *file)
403 {
404 return single_open(file, lstats_show_proc, inode);
405 }
406
407 static ssize_t lstats_write(struct file *file, const char __user *buf,
408 size_t count, loff_t *offs)
409 {
410 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
411
412 if (!task)
413 return -ESRCH;
414 clear_all_latency_tracing(task);
415 put_task_struct(task);
416
417 return count;
418 }
419
420 static const struct file_operations proc_lstats_operations = {
421 .open = lstats_open,
422 .read = seq_read,
423 .write = lstats_write,
424 .llseek = seq_lseek,
425 .release = single_release,
426 };
427
428 #endif
429
430 /* The badness from the OOM killer */
431 unsigned long badness(struct task_struct *p, unsigned long uptime);
432 static int proc_oom_score(struct task_struct *task, char *buffer)
433 {
434 unsigned long points = 0;
435 struct timespec uptime;
436
437 do_posix_clock_monotonic_gettime(&uptime);
438 read_lock(&tasklist_lock);
439 if (pid_alive(task))
440 points = badness(task, uptime.tv_sec);
441 read_unlock(&tasklist_lock);
442 return sprintf(buffer, "%lu\n", points);
443 }
444
445 struct limit_names {
446 char *name;
447 char *unit;
448 };
449
450 static const struct limit_names lnames[RLIM_NLIMITS] = {
451 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
452 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
453 [RLIMIT_DATA] = {"Max data size", "bytes"},
454 [RLIMIT_STACK] = {"Max stack size", "bytes"},
455 [RLIMIT_CORE] = {"Max core file size", "bytes"},
456 [RLIMIT_RSS] = {"Max resident set", "bytes"},
457 [RLIMIT_NPROC] = {"Max processes", "processes"},
458 [RLIMIT_NOFILE] = {"Max open files", "files"},
459 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
460 [RLIMIT_AS] = {"Max address space", "bytes"},
461 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
462 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
463 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
464 [RLIMIT_NICE] = {"Max nice priority", NULL},
465 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
466 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
467 };
468
469 /* Display limits for a process */
470 static int proc_pid_limits(struct task_struct *task, char *buffer)
471 {
472 unsigned int i;
473 int count = 0;
474 unsigned long flags;
475 char *bufptr = buffer;
476
477 struct rlimit rlim[RLIM_NLIMITS];
478
479 if (!lock_task_sighand(task, &flags))
480 return 0;
481 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
482 unlock_task_sighand(task, &flags);
483
484 /*
485 * print the file header
486 */
487 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
488 "Limit", "Soft Limit", "Hard Limit", "Units");
489
490 for (i = 0; i < RLIM_NLIMITS; i++) {
491 if (rlim[i].rlim_cur == RLIM_INFINITY)
492 count += sprintf(&bufptr[count], "%-25s %-20s ",
493 lnames[i].name, "unlimited");
494 else
495 count += sprintf(&bufptr[count], "%-25s %-20lu ",
496 lnames[i].name, rlim[i].rlim_cur);
497
498 if (rlim[i].rlim_max == RLIM_INFINITY)
499 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
500 else
501 count += sprintf(&bufptr[count], "%-20lu ",
502 rlim[i].rlim_max);
503
504 if (lnames[i].unit)
505 count += sprintf(&bufptr[count], "%-10s\n",
506 lnames[i].unit);
507 else
508 count += sprintf(&bufptr[count], "\n");
509 }
510
511 return count;
512 }
513
514 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
515 static int proc_pid_syscall(struct task_struct *task, char *buffer)
516 {
517 long nr;
518 unsigned long args[6], sp, pc;
519
520 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
521 return sprintf(buffer, "running\n");
522
523 if (nr < 0)
524 return sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
525
526 return sprintf(buffer,
527 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
528 nr,
529 args[0], args[1], args[2], args[3], args[4], args[5],
530 sp, pc);
531 }
532 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
533
534 /************************************************************************/
535 /* Here the fs part begins */
536 /************************************************************************/
537
538 /* permission checks */
539 static int proc_fd_access_allowed(struct inode *inode)
540 {
541 struct task_struct *task;
542 int allowed = 0;
543 /* Allow access to a task's file descriptors if it is us or we
544 * may use ptrace attach to the process and find out that
545 * information.
546 */
547 task = get_proc_task(inode);
548 if (task) {
549 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
550 put_task_struct(task);
551 }
552 return allowed;
553 }
554
555 static int proc_setattr(struct dentry *dentry, struct iattr *attr)
556 {
557 int error;
558 struct inode *inode = dentry->d_inode;
559
560 if (attr->ia_valid & ATTR_MODE)
561 return -EPERM;
562
563 error = inode_change_ok(inode, attr);
564 if (!error)
565 error = inode_setattr(inode, attr);
566 return error;
567 }
568
569 static const struct inode_operations proc_def_inode_operations = {
570 .setattr = proc_setattr,
571 };
572
573 static int mounts_open_common(struct inode *inode, struct file *file,
574 const struct seq_operations *op)
575 {
576 struct task_struct *task = get_proc_task(inode);
577 struct nsproxy *nsp;
578 struct mnt_namespace *ns = NULL;
579 struct path root;
580 struct proc_mounts *p;
581 int ret = -EINVAL;
582
583 if (task) {
584 rcu_read_lock();
585 nsp = task_nsproxy(task);
586 if (nsp) {
587 ns = nsp->mnt_ns;
588 if (ns)
589 get_mnt_ns(ns);
590 }
591 rcu_read_unlock();
592 if (ns && get_fs_path(task, &root, 1) == 0)
593 ret = 0;
594 put_task_struct(task);
595 }
596
597 if (!ns)
598 goto err;
599 if (ret)
600 goto err_put_ns;
601
602 ret = -ENOMEM;
603 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
604 if (!p)
605 goto err_put_path;
606
607 file->private_data = &p->m;
608 ret = seq_open(file, op);
609 if (ret)
610 goto err_free;
611
612 p->m.private = p;
613 p->ns = ns;
614 p->root = root;
615 p->event = ns->event;
616
617 return 0;
618
619 err_free:
620 kfree(p);
621 err_put_path:
622 path_put(&root);
623 err_put_ns:
624 put_mnt_ns(ns);
625 err:
626 return ret;
627 }
628
629 static int mounts_release(struct inode *inode, struct file *file)
630 {
631 struct proc_mounts *p = file->private_data;
632 path_put(&p->root);
633 put_mnt_ns(p->ns);
634 return seq_release(inode, file);
635 }
636
637 static unsigned mounts_poll(struct file *file, poll_table *wait)
638 {
639 struct proc_mounts *p = file->private_data;
640 unsigned res = POLLIN | POLLRDNORM;
641
642 poll_wait(file, &p->ns->poll, wait);
643 if (mnt_had_events(p))
644 res |= POLLERR | POLLPRI;
645
646 return res;
647 }
648
649 static int mounts_open(struct inode *inode, struct file *file)
650 {
651 return mounts_open_common(inode, file, &mounts_op);
652 }
653
654 static const struct file_operations proc_mounts_operations = {
655 .open = mounts_open,
656 .read = seq_read,
657 .llseek = seq_lseek,
658 .release = mounts_release,
659 .poll = mounts_poll,
660 };
661
662 static int mountinfo_open(struct inode *inode, struct file *file)
663 {
664 return mounts_open_common(inode, file, &mountinfo_op);
665 }
666
667 static const struct file_operations proc_mountinfo_operations = {
668 .open = mountinfo_open,
669 .read = seq_read,
670 .llseek = seq_lseek,
671 .release = mounts_release,
672 .poll = mounts_poll,
673 };
674
675 static int mountstats_open(struct inode *inode, struct file *file)
676 {
677 return mounts_open_common(inode, file, &mountstats_op);
678 }
679
680 static const struct file_operations proc_mountstats_operations = {
681 .open = mountstats_open,
682 .read = seq_read,
683 .llseek = seq_lseek,
684 .release = mounts_release,
685 };
686
687 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
688
689 static ssize_t proc_info_read(struct file * file, char __user * buf,
690 size_t count, loff_t *ppos)
691 {
692 struct inode * inode = file->f_path.dentry->d_inode;
693 unsigned long page;
694 ssize_t length;
695 struct task_struct *task = get_proc_task(inode);
696
697 length = -ESRCH;
698 if (!task)
699 goto out_no_task;
700
701 if (count > PROC_BLOCK_SIZE)
702 count = PROC_BLOCK_SIZE;
703
704 length = -ENOMEM;
705 if (!(page = __get_free_page(GFP_TEMPORARY)))
706 goto out;
707
708 length = PROC_I(inode)->op.proc_read(task, (char*)page);
709
710 if (length >= 0)
711 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
712 free_page(page);
713 out:
714 put_task_struct(task);
715 out_no_task:
716 return length;
717 }
718
719 static const struct file_operations proc_info_file_operations = {
720 .read = proc_info_read,
721 .llseek = generic_file_llseek,
722 };
723
724 static int proc_single_show(struct seq_file *m, void *v)
725 {
726 struct inode *inode = m->private;
727 struct pid_namespace *ns;
728 struct pid *pid;
729 struct task_struct *task;
730 int ret;
731
732 ns = inode->i_sb->s_fs_info;
733 pid = proc_pid(inode);
734 task = get_pid_task(pid, PIDTYPE_PID);
735 if (!task)
736 return -ESRCH;
737
738 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
739
740 put_task_struct(task);
741 return ret;
742 }
743
744 static int proc_single_open(struct inode *inode, struct file *filp)
745 {
746 int ret;
747 ret = single_open(filp, proc_single_show, NULL);
748 if (!ret) {
749 struct seq_file *m = filp->private_data;
750
751 m->private = inode;
752 }
753 return ret;
754 }
755
756 static const struct file_operations proc_single_file_operations = {
757 .open = proc_single_open,
758 .read = seq_read,
759 .llseek = seq_lseek,
760 .release = single_release,
761 };
762
763 static int mem_open(struct inode* inode, struct file* file)
764 {
765 file->private_data = (void*)((long)current->self_exec_id);
766 return 0;
767 }
768
769 static ssize_t mem_read(struct file * file, char __user * buf,
770 size_t count, loff_t *ppos)
771 {
772 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
773 char *page;
774 unsigned long src = *ppos;
775 int ret = -ESRCH;
776 struct mm_struct *mm;
777
778 if (!task)
779 goto out_no_task;
780
781 if (check_mem_permission(task))
782 goto out;
783
784 ret = -ENOMEM;
785 page = (char *)__get_free_page(GFP_TEMPORARY);
786 if (!page)
787 goto out;
788
789 ret = 0;
790
791 mm = get_task_mm(task);
792 if (!mm)
793 goto out_free;
794
795 ret = -EIO;
796
797 if (file->private_data != (void*)((long)current->self_exec_id))
798 goto out_put;
799
800 ret = 0;
801
802 while (count > 0) {
803 int this_len, retval;
804
805 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
806 retval = access_process_vm(task, src, page, this_len, 0);
807 if (!retval || check_mem_permission(task)) {
808 if (!ret)
809 ret = -EIO;
810 break;
811 }
812
813 if (copy_to_user(buf, page, retval)) {
814 ret = -EFAULT;
815 break;
816 }
817
818 ret += retval;
819 src += retval;
820 buf += retval;
821 count -= retval;
822 }
823 *ppos = src;
824
825 out_put:
826 mmput(mm);
827 out_free:
828 free_page((unsigned long) page);
829 out:
830 put_task_struct(task);
831 out_no_task:
832 return ret;
833 }
834
835 #define mem_write NULL
836
837 #ifndef mem_write
838 /* This is a security hazard */
839 static ssize_t mem_write(struct file * file, const char __user *buf,
840 size_t count, loff_t *ppos)
841 {
842 int copied;
843 char *page;
844 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
845 unsigned long dst = *ppos;
846
847 copied = -ESRCH;
848 if (!task)
849 goto out_no_task;
850
851 if (check_mem_permission(task))
852 goto out;
853
854 copied = -ENOMEM;
855 page = (char *)__get_free_page(GFP_TEMPORARY);
856 if (!page)
857 goto out;
858
859 copied = 0;
860 while (count > 0) {
861 int this_len, retval;
862
863 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
864 if (copy_from_user(page, buf, this_len)) {
865 copied = -EFAULT;
866 break;
867 }
868 retval = access_process_vm(task, dst, page, this_len, 1);
869 if (!retval) {
870 if (!copied)
871 copied = -EIO;
872 break;
873 }
874 copied += retval;
875 buf += retval;
876 dst += retval;
877 count -= retval;
878 }
879 *ppos = dst;
880 free_page((unsigned long) page);
881 out:
882 put_task_struct(task);
883 out_no_task:
884 return copied;
885 }
886 #endif
887
888 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
889 {
890 switch (orig) {
891 case 0:
892 file->f_pos = offset;
893 break;
894 case 1:
895 file->f_pos += offset;
896 break;
897 default:
898 return -EINVAL;
899 }
900 force_successful_syscall_return();
901 return file->f_pos;
902 }
903
904 static const struct file_operations proc_mem_operations = {
905 .llseek = mem_lseek,
906 .read = mem_read,
907 .write = mem_write,
908 .open = mem_open,
909 };
910
911 static ssize_t environ_read(struct file *file, char __user *buf,
912 size_t count, loff_t *ppos)
913 {
914 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
915 char *page;
916 unsigned long src = *ppos;
917 int ret = -ESRCH;
918 struct mm_struct *mm;
919
920 if (!task)
921 goto out_no_task;
922
923 if (!ptrace_may_access(task, PTRACE_MODE_READ))
924 goto out;
925
926 ret = -ENOMEM;
927 page = (char *)__get_free_page(GFP_TEMPORARY);
928 if (!page)
929 goto out;
930
931 ret = 0;
932
933 mm = get_task_mm(task);
934 if (!mm)
935 goto out_free;
936
937 while (count > 0) {
938 int this_len, retval, max_len;
939
940 this_len = mm->env_end - (mm->env_start + src);
941
942 if (this_len <= 0)
943 break;
944
945 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
946 this_len = (this_len > max_len) ? max_len : this_len;
947
948 retval = access_process_vm(task, (mm->env_start + src),
949 page, this_len, 0);
950
951 if (retval <= 0) {
952 ret = retval;
953 break;
954 }
955
956 if (copy_to_user(buf, page, retval)) {
957 ret = -EFAULT;
958 break;
959 }
960
961 ret += retval;
962 src += retval;
963 buf += retval;
964 count -= retval;
965 }
966 *ppos = src;
967
968 mmput(mm);
969 out_free:
970 free_page((unsigned long) page);
971 out:
972 put_task_struct(task);
973 out_no_task:
974 return ret;
975 }
976
977 static const struct file_operations proc_environ_operations = {
978 .read = environ_read,
979 .llseek = generic_file_llseek,
980 };
981
982 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
983 size_t count, loff_t *ppos)
984 {
985 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
986 char buffer[PROC_NUMBUF];
987 size_t len;
988 int oom_adjust = OOM_DISABLE;
989 unsigned long flags;
990
991 if (!task)
992 return -ESRCH;
993
994 if (lock_task_sighand(task, &flags)) {
995 oom_adjust = task->signal->oom_adj;
996 unlock_task_sighand(task, &flags);
997 }
998
999 put_task_struct(task);
1000
1001 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
1002
1003 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1004 }
1005
1006 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
1007 size_t count, loff_t *ppos)
1008 {
1009 struct task_struct *task;
1010 char buffer[PROC_NUMBUF];
1011 long oom_adjust;
1012 unsigned long flags;
1013 int err;
1014
1015 memset(buffer, 0, sizeof(buffer));
1016 if (count > sizeof(buffer) - 1)
1017 count = sizeof(buffer) - 1;
1018 if (copy_from_user(buffer, buf, count))
1019 return -EFAULT;
1020
1021 err = strict_strtol(strstrip(buffer), 0, &oom_adjust);
1022 if (err)
1023 return -EINVAL;
1024 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
1025 oom_adjust != OOM_DISABLE)
1026 return -EINVAL;
1027
1028 task = get_proc_task(file->f_path.dentry->d_inode);
1029 if (!task)
1030 return -ESRCH;
1031 if (!lock_task_sighand(task, &flags)) {
1032 put_task_struct(task);
1033 return -ESRCH;
1034 }
1035
1036 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
1037 unlock_task_sighand(task, &flags);
1038 put_task_struct(task);
1039 return -EACCES;
1040 }
1041
1042 task->signal->oom_adj = oom_adjust;
1043
1044 unlock_task_sighand(task, &flags);
1045 put_task_struct(task);
1046
1047 return count;
1048 }
1049
1050 static const struct file_operations proc_oom_adjust_operations = {
1051 .read = oom_adjust_read,
1052 .write = oom_adjust_write,
1053 .llseek = generic_file_llseek,
1054 };
1055
1056 #ifdef CONFIG_AUDITSYSCALL
1057 #define TMPBUFLEN 21
1058 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1059 size_t count, loff_t *ppos)
1060 {
1061 struct inode * inode = file->f_path.dentry->d_inode;
1062 struct task_struct *task = get_proc_task(inode);
1063 ssize_t length;
1064 char tmpbuf[TMPBUFLEN];
1065
1066 if (!task)
1067 return -ESRCH;
1068 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1069 audit_get_loginuid(task));
1070 put_task_struct(task);
1071 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1072 }
1073
1074 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1075 size_t count, loff_t *ppos)
1076 {
1077 struct inode * inode = file->f_path.dentry->d_inode;
1078 char *page, *tmp;
1079 ssize_t length;
1080 uid_t loginuid;
1081
1082 if (!capable(CAP_AUDIT_CONTROL))
1083 return -EPERM;
1084
1085 rcu_read_lock();
1086 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1087 rcu_read_unlock();
1088 return -EPERM;
1089 }
1090 rcu_read_unlock();
1091
1092 if (count >= PAGE_SIZE)
1093 count = PAGE_SIZE - 1;
1094
1095 if (*ppos != 0) {
1096 /* No partial writes. */
1097 return -EINVAL;
1098 }
1099 page = (char*)__get_free_page(GFP_TEMPORARY);
1100 if (!page)
1101 return -ENOMEM;
1102 length = -EFAULT;
1103 if (copy_from_user(page, buf, count))
1104 goto out_free_page;
1105
1106 page[count] = '\0';
1107 loginuid = simple_strtoul(page, &tmp, 10);
1108 if (tmp == page) {
1109 length = -EINVAL;
1110 goto out_free_page;
1111
1112 }
1113 length = audit_set_loginuid(current, loginuid);
1114 if (likely(length == 0))
1115 length = count;
1116
1117 out_free_page:
1118 free_page((unsigned long) page);
1119 return length;
1120 }
1121
1122 static const struct file_operations proc_loginuid_operations = {
1123 .read = proc_loginuid_read,
1124 .write = proc_loginuid_write,
1125 .llseek = generic_file_llseek,
1126 };
1127
1128 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1129 size_t count, loff_t *ppos)
1130 {
1131 struct inode * inode = file->f_path.dentry->d_inode;
1132 struct task_struct *task = get_proc_task(inode);
1133 ssize_t length;
1134 char tmpbuf[TMPBUFLEN];
1135
1136 if (!task)
1137 return -ESRCH;
1138 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1139 audit_get_sessionid(task));
1140 put_task_struct(task);
1141 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1142 }
1143
1144 static const struct file_operations proc_sessionid_operations = {
1145 .read = proc_sessionid_read,
1146 .llseek = generic_file_llseek,
1147 };
1148 #endif
1149
1150 #ifdef CONFIG_FAULT_INJECTION
1151 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1152 size_t count, loff_t *ppos)
1153 {
1154 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1155 char buffer[PROC_NUMBUF];
1156 size_t len;
1157 int make_it_fail;
1158
1159 if (!task)
1160 return -ESRCH;
1161 make_it_fail = task->make_it_fail;
1162 put_task_struct(task);
1163
1164 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1165
1166 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1167 }
1168
1169 static ssize_t proc_fault_inject_write(struct file * file,
1170 const char __user * buf, size_t count, loff_t *ppos)
1171 {
1172 struct task_struct *task;
1173 char buffer[PROC_NUMBUF], *end;
1174 int make_it_fail;
1175
1176 if (!capable(CAP_SYS_RESOURCE))
1177 return -EPERM;
1178 memset(buffer, 0, sizeof(buffer));
1179 if (count > sizeof(buffer) - 1)
1180 count = sizeof(buffer) - 1;
1181 if (copy_from_user(buffer, buf, count))
1182 return -EFAULT;
1183 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1184 if (*end)
1185 return -EINVAL;
1186 task = get_proc_task(file->f_dentry->d_inode);
1187 if (!task)
1188 return -ESRCH;
1189 task->make_it_fail = make_it_fail;
1190 put_task_struct(task);
1191
1192 return count;
1193 }
1194
1195 static const struct file_operations proc_fault_inject_operations = {
1196 .read = proc_fault_inject_read,
1197 .write = proc_fault_inject_write,
1198 .llseek = generic_file_llseek,
1199 };
1200 #endif
1201
1202
1203 #ifdef CONFIG_SCHED_DEBUG
1204 /*
1205 * Print out various scheduling related per-task fields:
1206 */
1207 static int sched_show(struct seq_file *m, void *v)
1208 {
1209 struct inode *inode = m->private;
1210 struct task_struct *p;
1211
1212 p = get_proc_task(inode);
1213 if (!p)
1214 return -ESRCH;
1215 proc_sched_show_task(p, m);
1216
1217 put_task_struct(p);
1218
1219 return 0;
1220 }
1221
1222 static ssize_t
1223 sched_write(struct file *file, const char __user *buf,
1224 size_t count, loff_t *offset)
1225 {
1226 struct inode *inode = file->f_path.dentry->d_inode;
1227 struct task_struct *p;
1228
1229 p = get_proc_task(inode);
1230 if (!p)
1231 return -ESRCH;
1232 proc_sched_set_task(p);
1233
1234 put_task_struct(p);
1235
1236 return count;
1237 }
1238
1239 static int sched_open(struct inode *inode, struct file *filp)
1240 {
1241 int ret;
1242
1243 ret = single_open(filp, sched_show, NULL);
1244 if (!ret) {
1245 struct seq_file *m = filp->private_data;
1246
1247 m->private = inode;
1248 }
1249 return ret;
1250 }
1251
1252 static const struct file_operations proc_pid_sched_operations = {
1253 .open = sched_open,
1254 .read = seq_read,
1255 .write = sched_write,
1256 .llseek = seq_lseek,
1257 .release = single_release,
1258 };
1259
1260 #endif
1261
1262 static ssize_t comm_write(struct file *file, const char __user *buf,
1263 size_t count, loff_t *offset)
1264 {
1265 struct inode *inode = file->f_path.dentry->d_inode;
1266 struct task_struct *p;
1267 char buffer[TASK_COMM_LEN];
1268
1269 memset(buffer, 0, sizeof(buffer));
1270 if (count > sizeof(buffer) - 1)
1271 count = sizeof(buffer) - 1;
1272 if (copy_from_user(buffer, buf, count))
1273 return -EFAULT;
1274
1275 p = get_proc_task(inode);
1276 if (!p)
1277 return -ESRCH;
1278
1279 if (same_thread_group(current, p))
1280 set_task_comm(p, buffer);
1281 else
1282 count = -EINVAL;
1283
1284 put_task_struct(p);
1285
1286 return count;
1287 }
1288
1289 static int comm_show(struct seq_file *m, void *v)
1290 {
1291 struct inode *inode = m->private;
1292 struct task_struct *p;
1293
1294 p = get_proc_task(inode);
1295 if (!p)
1296 return -ESRCH;
1297
1298 task_lock(p);
1299 seq_printf(m, "%s\n", p->comm);
1300 task_unlock(p);
1301
1302 put_task_struct(p);
1303
1304 return 0;
1305 }
1306
1307 static int comm_open(struct inode *inode, struct file *filp)
1308 {
1309 int ret;
1310
1311 ret = single_open(filp, comm_show, NULL);
1312 if (!ret) {
1313 struct seq_file *m = filp->private_data;
1314
1315 m->private = inode;
1316 }
1317 return ret;
1318 }
1319
1320 static const struct file_operations proc_pid_set_comm_operations = {
1321 .open = comm_open,
1322 .read = seq_read,
1323 .write = comm_write,
1324 .llseek = seq_lseek,
1325 .release = single_release,
1326 };
1327
1328 /*
1329 * We added or removed a vma mapping the executable. The vmas are only mapped
1330 * during exec and are not mapped with the mmap system call.
1331 * Callers must hold down_write() on the mm's mmap_sem for these
1332 */
1333 void added_exe_file_vma(struct mm_struct *mm)
1334 {
1335 mm->num_exe_file_vmas++;
1336 }
1337
1338 void removed_exe_file_vma(struct mm_struct *mm)
1339 {
1340 mm->num_exe_file_vmas--;
1341 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){
1342 fput(mm->exe_file);
1343 mm->exe_file = NULL;
1344 }
1345
1346 }
1347
1348 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file)
1349 {
1350 if (new_exe_file)
1351 get_file(new_exe_file);
1352 if (mm->exe_file)
1353 fput(mm->exe_file);
1354 mm->exe_file = new_exe_file;
1355 mm->num_exe_file_vmas = 0;
1356 }
1357
1358 struct file *get_mm_exe_file(struct mm_struct *mm)
1359 {
1360 struct file *exe_file;
1361
1362 /* We need mmap_sem to protect against races with removal of
1363 * VM_EXECUTABLE vmas */
1364 down_read(&mm->mmap_sem);
1365 exe_file = mm->exe_file;
1366 if (exe_file)
1367 get_file(exe_file);
1368 up_read(&mm->mmap_sem);
1369 return exe_file;
1370 }
1371
1372 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm)
1373 {
1374 /* It's safe to write the exe_file pointer without exe_file_lock because
1375 * this is called during fork when the task is not yet in /proc */
1376 newmm->exe_file = get_mm_exe_file(oldmm);
1377 }
1378
1379 static int proc_exe_link(struct inode *inode, struct path *exe_path)
1380 {
1381 struct task_struct *task;
1382 struct mm_struct *mm;
1383 struct file *exe_file;
1384
1385 task = get_proc_task(inode);
1386 if (!task)
1387 return -ENOENT;
1388 mm = get_task_mm(task);
1389 put_task_struct(task);
1390 if (!mm)
1391 return -ENOENT;
1392 exe_file = get_mm_exe_file(mm);
1393 mmput(mm);
1394 if (exe_file) {
1395 *exe_path = exe_file->f_path;
1396 path_get(&exe_file->f_path);
1397 fput(exe_file);
1398 return 0;
1399 } else
1400 return -ENOENT;
1401 }
1402
1403 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1404 {
1405 struct inode *inode = dentry->d_inode;
1406 int error = -EACCES;
1407
1408 /* We don't need a base pointer in the /proc filesystem */
1409 path_put(&nd->path);
1410
1411 /* Are we allowed to snoop on the tasks file descriptors? */
1412 if (!proc_fd_access_allowed(inode))
1413 goto out;
1414
1415 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
1416 out:
1417 return ERR_PTR(error);
1418 }
1419
1420 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1421 {
1422 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1423 char *pathname;
1424 int len;
1425
1426 if (!tmp)
1427 return -ENOMEM;
1428
1429 pathname = d_path(path, tmp, PAGE_SIZE);
1430 len = PTR_ERR(pathname);
1431 if (IS_ERR(pathname))
1432 goto out;
1433 len = tmp + PAGE_SIZE - 1 - pathname;
1434
1435 if (len > buflen)
1436 len = buflen;
1437 if (copy_to_user(buffer, pathname, len))
1438 len = -EFAULT;
1439 out:
1440 free_page((unsigned long)tmp);
1441 return len;
1442 }
1443
1444 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1445 {
1446 int error = -EACCES;
1447 struct inode *inode = dentry->d_inode;
1448 struct path path;
1449
1450 /* Are we allowed to snoop on the tasks file descriptors? */
1451 if (!proc_fd_access_allowed(inode))
1452 goto out;
1453
1454 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1455 if (error)
1456 goto out;
1457
1458 error = do_proc_readlink(&path, buffer, buflen);
1459 path_put(&path);
1460 out:
1461 return error;
1462 }
1463
1464 static const struct inode_operations proc_pid_link_inode_operations = {
1465 .readlink = proc_pid_readlink,
1466 .follow_link = proc_pid_follow_link,
1467 .setattr = proc_setattr,
1468 };
1469
1470
1471 /* building an inode */
1472
1473 static int task_dumpable(struct task_struct *task)
1474 {
1475 int dumpable = 0;
1476 struct mm_struct *mm;
1477
1478 task_lock(task);
1479 mm = task->mm;
1480 if (mm)
1481 dumpable = get_dumpable(mm);
1482 task_unlock(task);
1483 if(dumpable == 1)
1484 return 1;
1485 return 0;
1486 }
1487
1488
1489 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1490 {
1491 struct inode * inode;
1492 struct proc_inode *ei;
1493 const struct cred *cred;
1494
1495 /* We need a new inode */
1496
1497 inode = new_inode(sb);
1498 if (!inode)
1499 goto out;
1500
1501 /* Common stuff */
1502 ei = PROC_I(inode);
1503 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1504 inode->i_op = &proc_def_inode_operations;
1505
1506 /*
1507 * grab the reference to task.
1508 */
1509 ei->pid = get_task_pid(task, PIDTYPE_PID);
1510 if (!ei->pid)
1511 goto out_unlock;
1512
1513 if (task_dumpable(task)) {
1514 rcu_read_lock();
1515 cred = __task_cred(task);
1516 inode->i_uid = cred->euid;
1517 inode->i_gid = cred->egid;
1518 rcu_read_unlock();
1519 }
1520 security_task_to_inode(task, inode);
1521
1522 out:
1523 return inode;
1524
1525 out_unlock:
1526 iput(inode);
1527 return NULL;
1528 }
1529
1530 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1531 {
1532 struct inode *inode = dentry->d_inode;
1533 struct task_struct *task;
1534 const struct cred *cred;
1535
1536 generic_fillattr(inode, stat);
1537
1538 rcu_read_lock();
1539 stat->uid = 0;
1540 stat->gid = 0;
1541 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1542 if (task) {
1543 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1544 task_dumpable(task)) {
1545 cred = __task_cred(task);
1546 stat->uid = cred->euid;
1547 stat->gid = cred->egid;
1548 }
1549 }
1550 rcu_read_unlock();
1551 return 0;
1552 }
1553
1554 /* dentry stuff */
1555
1556 /*
1557 * Exceptional case: normally we are not allowed to unhash a busy
1558 * directory. In this case, however, we can do it - no aliasing problems
1559 * due to the way we treat inodes.
1560 *
1561 * Rewrite the inode's ownerships here because the owning task may have
1562 * performed a setuid(), etc.
1563 *
1564 * Before the /proc/pid/status file was created the only way to read
1565 * the effective uid of a /process was to stat /proc/pid. Reading
1566 * /proc/pid/status is slow enough that procps and other packages
1567 * kept stating /proc/pid. To keep the rules in /proc simple I have
1568 * made this apply to all per process world readable and executable
1569 * directories.
1570 */
1571 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1572 {
1573 struct inode *inode = dentry->d_inode;
1574 struct task_struct *task = get_proc_task(inode);
1575 const struct cred *cred;
1576
1577 if (task) {
1578 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1579 task_dumpable(task)) {
1580 rcu_read_lock();
1581 cred = __task_cred(task);
1582 inode->i_uid = cred->euid;
1583 inode->i_gid = cred->egid;
1584 rcu_read_unlock();
1585 } else {
1586 inode->i_uid = 0;
1587 inode->i_gid = 0;
1588 }
1589 inode->i_mode &= ~(S_ISUID | S_ISGID);
1590 security_task_to_inode(task, inode);
1591 put_task_struct(task);
1592 return 1;
1593 }
1594 d_drop(dentry);
1595 return 0;
1596 }
1597
1598 static int pid_delete_dentry(struct dentry * dentry)
1599 {
1600 /* Is the task we represent dead?
1601 * If so, then don't put the dentry on the lru list,
1602 * kill it immediately.
1603 */
1604 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1605 }
1606
1607 static const struct dentry_operations pid_dentry_operations =
1608 {
1609 .d_revalidate = pid_revalidate,
1610 .d_delete = pid_delete_dentry,
1611 };
1612
1613 /* Lookups */
1614
1615 typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
1616 struct task_struct *, const void *);
1617
1618 /*
1619 * Fill a directory entry.
1620 *
1621 * If possible create the dcache entry and derive our inode number and
1622 * file type from dcache entry.
1623 *
1624 * Since all of the proc inode numbers are dynamically generated, the inode
1625 * numbers do not exist until the inode is cache. This means creating the
1626 * the dcache entry in readdir is necessary to keep the inode numbers
1627 * reported by readdir in sync with the inode numbers reported
1628 * by stat.
1629 */
1630 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1631 char *name, int len,
1632 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1633 {
1634 struct dentry *child, *dir = filp->f_path.dentry;
1635 struct inode *inode;
1636 struct qstr qname;
1637 ino_t ino = 0;
1638 unsigned type = DT_UNKNOWN;
1639
1640 qname.name = name;
1641 qname.len = len;
1642 qname.hash = full_name_hash(name, len);
1643
1644 child = d_lookup(dir, &qname);
1645 if (!child) {
1646 struct dentry *new;
1647 new = d_alloc(dir, &qname);
1648 if (new) {
1649 child = instantiate(dir->d_inode, new, task, ptr);
1650 if (child)
1651 dput(new);
1652 else
1653 child = new;
1654 }
1655 }
1656 if (!child || IS_ERR(child) || !child->d_inode)
1657 goto end_instantiate;
1658 inode = child->d_inode;
1659 if (inode) {
1660 ino = inode->i_ino;
1661 type = inode->i_mode >> 12;
1662 }
1663 dput(child);
1664 end_instantiate:
1665 if (!ino)
1666 ino = find_inode_number(dir, &qname);
1667 if (!ino)
1668 ino = 1;
1669 return filldir(dirent, name, len, filp->f_pos, ino, type);
1670 }
1671
1672 static unsigned name_to_int(struct dentry *dentry)
1673 {
1674 const char *name = dentry->d_name.name;
1675 int len = dentry->d_name.len;
1676 unsigned n = 0;
1677
1678 if (len > 1 && *name == '0')
1679 goto out;
1680 while (len-- > 0) {
1681 unsigned c = *name++ - '0';
1682 if (c > 9)
1683 goto out;
1684 if (n >= (~0U-9)/10)
1685 goto out;
1686 n *= 10;
1687 n += c;
1688 }
1689 return n;
1690 out:
1691 return ~0U;
1692 }
1693
1694 #define PROC_FDINFO_MAX 64
1695
1696 static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1697 {
1698 struct task_struct *task = get_proc_task(inode);
1699 struct files_struct *files = NULL;
1700 struct file *file;
1701 int fd = proc_fd(inode);
1702
1703 if (task) {
1704 files = get_files_struct(task);
1705 put_task_struct(task);
1706 }
1707 if (files) {
1708 /*
1709 * We are not taking a ref to the file structure, so we must
1710 * hold ->file_lock.
1711 */
1712 spin_lock(&files->file_lock);
1713 file = fcheck_files(files, fd);
1714 if (file) {
1715 if (path) {
1716 *path = file->f_path;
1717 path_get(&file->f_path);
1718 }
1719 if (info)
1720 snprintf(info, PROC_FDINFO_MAX,
1721 "pos:\t%lli\n"
1722 "flags:\t0%o\n",
1723 (long long) file->f_pos,
1724 file->f_flags);
1725 spin_unlock(&files->file_lock);
1726 put_files_struct(files);
1727 return 0;
1728 }
1729 spin_unlock(&files->file_lock);
1730 put_files_struct(files);
1731 }
1732 return -ENOENT;
1733 }
1734
1735 static int proc_fd_link(struct inode *inode, struct path *path)
1736 {
1737 return proc_fd_info(inode, path, NULL);
1738 }
1739
1740 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1741 {
1742 struct inode *inode = dentry->d_inode;
1743 struct task_struct *task = get_proc_task(inode);
1744 int fd = proc_fd(inode);
1745 struct files_struct *files;
1746 const struct cred *cred;
1747
1748 if (task) {
1749 files = get_files_struct(task);
1750 if (files) {
1751 rcu_read_lock();
1752 if (fcheck_files(files, fd)) {
1753 rcu_read_unlock();
1754 put_files_struct(files);
1755 if (task_dumpable(task)) {
1756 rcu_read_lock();
1757 cred = __task_cred(task);
1758 inode->i_uid = cred->euid;
1759 inode->i_gid = cred->egid;
1760 rcu_read_unlock();
1761 } else {
1762 inode->i_uid = 0;
1763 inode->i_gid = 0;
1764 }
1765 inode->i_mode &= ~(S_ISUID | S_ISGID);
1766 security_task_to_inode(task, inode);
1767 put_task_struct(task);
1768 return 1;
1769 }
1770 rcu_read_unlock();
1771 put_files_struct(files);
1772 }
1773 put_task_struct(task);
1774 }
1775 d_drop(dentry);
1776 return 0;
1777 }
1778
1779 static const struct dentry_operations tid_fd_dentry_operations =
1780 {
1781 .d_revalidate = tid_fd_revalidate,
1782 .d_delete = pid_delete_dentry,
1783 };
1784
1785 static struct dentry *proc_fd_instantiate(struct inode *dir,
1786 struct dentry *dentry, struct task_struct *task, const void *ptr)
1787 {
1788 unsigned fd = *(const unsigned *)ptr;
1789 struct file *file;
1790 struct files_struct *files;
1791 struct inode *inode;
1792 struct proc_inode *ei;
1793 struct dentry *error = ERR_PTR(-ENOENT);
1794
1795 inode = proc_pid_make_inode(dir->i_sb, task);
1796 if (!inode)
1797 goto out;
1798 ei = PROC_I(inode);
1799 ei->fd = fd;
1800 files = get_files_struct(task);
1801 if (!files)
1802 goto out_iput;
1803 inode->i_mode = S_IFLNK;
1804
1805 /*
1806 * We are not taking a ref to the file structure, so we must
1807 * hold ->file_lock.
1808 */
1809 spin_lock(&files->file_lock);
1810 file = fcheck_files(files, fd);
1811 if (!file)
1812 goto out_unlock;
1813 if (file->f_mode & FMODE_READ)
1814 inode->i_mode |= S_IRUSR | S_IXUSR;
1815 if (file->f_mode & FMODE_WRITE)
1816 inode->i_mode |= S_IWUSR | S_IXUSR;
1817 spin_unlock(&files->file_lock);
1818 put_files_struct(files);
1819
1820 inode->i_op = &proc_pid_link_inode_operations;
1821 inode->i_size = 64;
1822 ei->op.proc_get_link = proc_fd_link;
1823 dentry->d_op = &tid_fd_dentry_operations;
1824 d_add(dentry, inode);
1825 /* Close the race of the process dying before we return the dentry */
1826 if (tid_fd_revalidate(dentry, NULL))
1827 error = NULL;
1828
1829 out:
1830 return error;
1831 out_unlock:
1832 spin_unlock(&files->file_lock);
1833 put_files_struct(files);
1834 out_iput:
1835 iput(inode);
1836 goto out;
1837 }
1838
1839 static struct dentry *proc_lookupfd_common(struct inode *dir,
1840 struct dentry *dentry,
1841 instantiate_t instantiate)
1842 {
1843 struct task_struct *task = get_proc_task(dir);
1844 unsigned fd = name_to_int(dentry);
1845 struct dentry *result = ERR_PTR(-ENOENT);
1846
1847 if (!task)
1848 goto out_no_task;
1849 if (fd == ~0U)
1850 goto out;
1851
1852 result = instantiate(dir, dentry, task, &fd);
1853 out:
1854 put_task_struct(task);
1855 out_no_task:
1856 return result;
1857 }
1858
1859 static int proc_readfd_common(struct file * filp, void * dirent,
1860 filldir_t filldir, instantiate_t instantiate)
1861 {
1862 struct dentry *dentry = filp->f_path.dentry;
1863 struct inode *inode = dentry->d_inode;
1864 struct task_struct *p = get_proc_task(inode);
1865 unsigned int fd, ino;
1866 int retval;
1867 struct files_struct * files;
1868
1869 retval = -ENOENT;
1870 if (!p)
1871 goto out_no_task;
1872 retval = 0;
1873
1874 fd = filp->f_pos;
1875 switch (fd) {
1876 case 0:
1877 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1878 goto out;
1879 filp->f_pos++;
1880 case 1:
1881 ino = parent_ino(dentry);
1882 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1883 goto out;
1884 filp->f_pos++;
1885 default:
1886 files = get_files_struct(p);
1887 if (!files)
1888 goto out;
1889 rcu_read_lock();
1890 for (fd = filp->f_pos-2;
1891 fd < files_fdtable(files)->max_fds;
1892 fd++, filp->f_pos++) {
1893 char name[PROC_NUMBUF];
1894 int len;
1895
1896 if (!fcheck_files(files, fd))
1897 continue;
1898 rcu_read_unlock();
1899
1900 len = snprintf(name, sizeof(name), "%d", fd);
1901 if (proc_fill_cache(filp, dirent, filldir,
1902 name, len, instantiate,
1903 p, &fd) < 0) {
1904 rcu_read_lock();
1905 break;
1906 }
1907 rcu_read_lock();
1908 }
1909 rcu_read_unlock();
1910 put_files_struct(files);
1911 }
1912 out:
1913 put_task_struct(p);
1914 out_no_task:
1915 return retval;
1916 }
1917
1918 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
1919 struct nameidata *nd)
1920 {
1921 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
1922 }
1923
1924 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
1925 {
1926 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
1927 }
1928
1929 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
1930 size_t len, loff_t *ppos)
1931 {
1932 char tmp[PROC_FDINFO_MAX];
1933 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
1934 if (!err)
1935 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
1936 return err;
1937 }
1938
1939 static const struct file_operations proc_fdinfo_file_operations = {
1940 .open = nonseekable_open,
1941 .read = proc_fdinfo_read,
1942 };
1943
1944 static const struct file_operations proc_fd_operations = {
1945 .read = generic_read_dir,
1946 .readdir = proc_readfd,
1947 };
1948
1949 /*
1950 * /proc/pid/fd needs a special permission handler so that a process can still
1951 * access /proc/self/fd after it has executed a setuid().
1952 */
1953 static int proc_fd_permission(struct inode *inode, int mask)
1954 {
1955 int rv;
1956
1957 rv = generic_permission(inode, mask, NULL);
1958 if (rv == 0)
1959 return 0;
1960 if (task_pid(current) == proc_pid(inode))
1961 rv = 0;
1962 return rv;
1963 }
1964
1965 /*
1966 * proc directories can do almost nothing..
1967 */
1968 static const struct inode_operations proc_fd_inode_operations = {
1969 .lookup = proc_lookupfd,
1970 .permission = proc_fd_permission,
1971 .setattr = proc_setattr,
1972 };
1973
1974 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
1975 struct dentry *dentry, struct task_struct *task, const void *ptr)
1976 {
1977 unsigned fd = *(unsigned *)ptr;
1978 struct inode *inode;
1979 struct proc_inode *ei;
1980 struct dentry *error = ERR_PTR(-ENOENT);
1981
1982 inode = proc_pid_make_inode(dir->i_sb, task);
1983 if (!inode)
1984 goto out;
1985 ei = PROC_I(inode);
1986 ei->fd = fd;
1987 inode->i_mode = S_IFREG | S_IRUSR;
1988 inode->i_fop = &proc_fdinfo_file_operations;
1989 dentry->d_op = &tid_fd_dentry_operations;
1990 d_add(dentry, inode);
1991 /* Close the race of the process dying before we return the dentry */
1992 if (tid_fd_revalidate(dentry, NULL))
1993 error = NULL;
1994
1995 out:
1996 return error;
1997 }
1998
1999 static struct dentry *proc_lookupfdinfo(struct inode *dir,
2000 struct dentry *dentry,
2001 struct nameidata *nd)
2002 {
2003 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2004 }
2005
2006 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2007 {
2008 return proc_readfd_common(filp, dirent, filldir,
2009 proc_fdinfo_instantiate);
2010 }
2011
2012 static const struct file_operations proc_fdinfo_operations = {
2013 .read = generic_read_dir,
2014 .readdir = proc_readfdinfo,
2015 };
2016
2017 /*
2018 * proc directories can do almost nothing..
2019 */
2020 static const struct inode_operations proc_fdinfo_inode_operations = {
2021 .lookup = proc_lookupfdinfo,
2022 .setattr = proc_setattr,
2023 };
2024
2025
2026 static struct dentry *proc_pident_instantiate(struct inode *dir,
2027 struct dentry *dentry, struct task_struct *task, const void *ptr)
2028 {
2029 const struct pid_entry *p = ptr;
2030 struct inode *inode;
2031 struct proc_inode *ei;
2032 struct dentry *error = ERR_PTR(-ENOENT);
2033
2034 inode = proc_pid_make_inode(dir->i_sb, task);
2035 if (!inode)
2036 goto out;
2037
2038 ei = PROC_I(inode);
2039 inode->i_mode = p->mode;
2040 if (S_ISDIR(inode->i_mode))
2041 inode->i_nlink = 2; /* Use getattr to fix if necessary */
2042 if (p->iop)
2043 inode->i_op = p->iop;
2044 if (p->fop)
2045 inode->i_fop = p->fop;
2046 ei->op = p->op;
2047 dentry->d_op = &pid_dentry_operations;
2048 d_add(dentry, inode);
2049 /* Close the race of the process dying before we return the dentry */
2050 if (pid_revalidate(dentry, NULL))
2051 error = NULL;
2052 out:
2053 return error;
2054 }
2055
2056 static struct dentry *proc_pident_lookup(struct inode *dir,
2057 struct dentry *dentry,
2058 const struct pid_entry *ents,
2059 unsigned int nents)
2060 {
2061 struct dentry *error;
2062 struct task_struct *task = get_proc_task(dir);
2063 const struct pid_entry *p, *last;
2064
2065 error = ERR_PTR(-ENOENT);
2066
2067 if (!task)
2068 goto out_no_task;
2069
2070 /*
2071 * Yes, it does not scale. And it should not. Don't add
2072 * new entries into /proc/<tgid>/ without very good reasons.
2073 */
2074 last = &ents[nents - 1];
2075 for (p = ents; p <= last; p++) {
2076 if (p->len != dentry->d_name.len)
2077 continue;
2078 if (!memcmp(dentry->d_name.name, p->name, p->len))
2079 break;
2080 }
2081 if (p > last)
2082 goto out;
2083
2084 error = proc_pident_instantiate(dir, dentry, task, p);
2085 out:
2086 put_task_struct(task);
2087 out_no_task:
2088 return error;
2089 }
2090
2091 static int proc_pident_fill_cache(struct file *filp, void *dirent,
2092 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2093 {
2094 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2095 proc_pident_instantiate, task, p);
2096 }
2097
2098 static int proc_pident_readdir(struct file *filp,
2099 void *dirent, filldir_t filldir,
2100 const struct pid_entry *ents, unsigned int nents)
2101 {
2102 int i;
2103 struct dentry *dentry = filp->f_path.dentry;
2104 struct inode *inode = dentry->d_inode;
2105 struct task_struct *task = get_proc_task(inode);
2106 const struct pid_entry *p, *last;
2107 ino_t ino;
2108 int ret;
2109
2110 ret = -ENOENT;
2111 if (!task)
2112 goto out_no_task;
2113
2114 ret = 0;
2115 i = filp->f_pos;
2116 switch (i) {
2117 case 0:
2118 ino = inode->i_ino;
2119 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2120 goto out;
2121 i++;
2122 filp->f_pos++;
2123 /* fall through */
2124 case 1:
2125 ino = parent_ino(dentry);
2126 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2127 goto out;
2128 i++;
2129 filp->f_pos++;
2130 /* fall through */
2131 default:
2132 i -= 2;
2133 if (i >= nents) {
2134 ret = 1;
2135 goto out;
2136 }
2137 p = ents + i;
2138 last = &ents[nents - 1];
2139 while (p <= last) {
2140 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2141 goto out;
2142 filp->f_pos++;
2143 p++;
2144 }
2145 }
2146
2147 ret = 1;
2148 out:
2149 put_task_struct(task);
2150 out_no_task:
2151 return ret;
2152 }
2153
2154 #ifdef CONFIG_SECURITY
2155 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2156 size_t count, loff_t *ppos)
2157 {
2158 struct inode * inode = file->f_path.dentry->d_inode;
2159 char *p = NULL;
2160 ssize_t length;
2161 struct task_struct *task = get_proc_task(inode);
2162
2163 if (!task)
2164 return -ESRCH;
2165
2166 length = security_getprocattr(task,
2167 (char*)file->f_path.dentry->d_name.name,
2168 &p);
2169 put_task_struct(task);
2170 if (length > 0)
2171 length = simple_read_from_buffer(buf, count, ppos, p, length);
2172 kfree(p);
2173 return length;
2174 }
2175
2176 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2177 size_t count, loff_t *ppos)
2178 {
2179 struct inode * inode = file->f_path.dentry->d_inode;
2180 char *page;
2181 ssize_t length;
2182 struct task_struct *task = get_proc_task(inode);
2183
2184 length = -ESRCH;
2185 if (!task)
2186 goto out_no_task;
2187 if (count > PAGE_SIZE)
2188 count = PAGE_SIZE;
2189
2190 /* No partial writes. */
2191 length = -EINVAL;
2192 if (*ppos != 0)
2193 goto out;
2194
2195 length = -ENOMEM;
2196 page = (char*)__get_free_page(GFP_TEMPORARY);
2197 if (!page)
2198 goto out;
2199
2200 length = -EFAULT;
2201 if (copy_from_user(page, buf, count))
2202 goto out_free;
2203
2204 /* Guard against adverse ptrace interaction */
2205 length = mutex_lock_interruptible(&task->cred_guard_mutex);
2206 if (length < 0)
2207 goto out_free;
2208
2209 length = security_setprocattr(task,
2210 (char*)file->f_path.dentry->d_name.name,
2211 (void*)page, count);
2212 mutex_unlock(&task->cred_guard_mutex);
2213 out_free:
2214 free_page((unsigned long) page);
2215 out:
2216 put_task_struct(task);
2217 out_no_task:
2218 return length;
2219 }
2220
2221 static const struct file_operations proc_pid_attr_operations = {
2222 .read = proc_pid_attr_read,
2223 .write = proc_pid_attr_write,
2224 .llseek = generic_file_llseek,
2225 };
2226
2227 static const struct pid_entry attr_dir_stuff[] = {
2228 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2229 REG("prev", S_IRUGO, proc_pid_attr_operations),
2230 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2231 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2232 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2233 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2234 };
2235
2236 static int proc_attr_dir_readdir(struct file * filp,
2237 void * dirent, filldir_t filldir)
2238 {
2239 return proc_pident_readdir(filp,dirent,filldir,
2240 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2241 }
2242
2243 static const struct file_operations proc_attr_dir_operations = {
2244 .read = generic_read_dir,
2245 .readdir = proc_attr_dir_readdir,
2246 };
2247
2248 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2249 struct dentry *dentry, struct nameidata *nd)
2250 {
2251 return proc_pident_lookup(dir, dentry,
2252 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2253 }
2254
2255 static const struct inode_operations proc_attr_dir_inode_operations = {
2256 .lookup = proc_attr_dir_lookup,
2257 .getattr = pid_getattr,
2258 .setattr = proc_setattr,
2259 };
2260
2261 #endif
2262
2263 #ifdef CONFIG_ELF_CORE
2264 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2265 size_t count, loff_t *ppos)
2266 {
2267 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2268 struct mm_struct *mm;
2269 char buffer[PROC_NUMBUF];
2270 size_t len;
2271 int ret;
2272
2273 if (!task)
2274 return -ESRCH;
2275
2276 ret = 0;
2277 mm = get_task_mm(task);
2278 if (mm) {
2279 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2280 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2281 MMF_DUMP_FILTER_SHIFT));
2282 mmput(mm);
2283 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2284 }
2285
2286 put_task_struct(task);
2287
2288 return ret;
2289 }
2290
2291 static ssize_t proc_coredump_filter_write(struct file *file,
2292 const char __user *buf,
2293 size_t count,
2294 loff_t *ppos)
2295 {
2296 struct task_struct *task;
2297 struct mm_struct *mm;
2298 char buffer[PROC_NUMBUF], *end;
2299 unsigned int val;
2300 int ret;
2301 int i;
2302 unsigned long mask;
2303
2304 ret = -EFAULT;
2305 memset(buffer, 0, sizeof(buffer));
2306 if (count > sizeof(buffer) - 1)
2307 count = sizeof(buffer) - 1;
2308 if (copy_from_user(buffer, buf, count))
2309 goto out_no_task;
2310
2311 ret = -EINVAL;
2312 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2313 if (*end == '\n')
2314 end++;
2315 if (end - buffer == 0)
2316 goto out_no_task;
2317
2318 ret = -ESRCH;
2319 task = get_proc_task(file->f_dentry->d_inode);
2320 if (!task)
2321 goto out_no_task;
2322
2323 ret = end - buffer;
2324 mm = get_task_mm(task);
2325 if (!mm)
2326 goto out_no_mm;
2327
2328 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2329 if (val & mask)
2330 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2331 else
2332 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2333 }
2334
2335 mmput(mm);
2336 out_no_mm:
2337 put_task_struct(task);
2338 out_no_task:
2339 return ret;
2340 }
2341
2342 static const struct file_operations proc_coredump_filter_operations = {
2343 .read = proc_coredump_filter_read,
2344 .write = proc_coredump_filter_write,
2345 .llseek = generic_file_llseek,
2346 };
2347 #endif
2348
2349 /*
2350 * /proc/self:
2351 */
2352 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2353 int buflen)
2354 {
2355 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2356 pid_t tgid = task_tgid_nr_ns(current, ns);
2357 char tmp[PROC_NUMBUF];
2358 if (!tgid)
2359 return -ENOENT;
2360 sprintf(tmp, "%d", tgid);
2361 return vfs_readlink(dentry,buffer,buflen,tmp);
2362 }
2363
2364 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2365 {
2366 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2367 pid_t tgid = task_tgid_nr_ns(current, ns);
2368 char *name = ERR_PTR(-ENOENT);
2369 if (tgid) {
2370 name = __getname();
2371 if (!name)
2372 name = ERR_PTR(-ENOMEM);
2373 else
2374 sprintf(name, "%d", tgid);
2375 }
2376 nd_set_link(nd, name);
2377 return NULL;
2378 }
2379
2380 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2381 void *cookie)
2382 {
2383 char *s = nd_get_link(nd);
2384 if (!IS_ERR(s))
2385 __putname(s);
2386 }
2387
2388 static const struct inode_operations proc_self_inode_operations = {
2389 .readlink = proc_self_readlink,
2390 .follow_link = proc_self_follow_link,
2391 .put_link = proc_self_put_link,
2392 };
2393
2394 /*
2395 * proc base
2396 *
2397 * These are the directory entries in the root directory of /proc
2398 * that properly belong to the /proc filesystem, as they describe
2399 * describe something that is process related.
2400 */
2401 static const struct pid_entry proc_base_stuff[] = {
2402 NOD("self", S_IFLNK|S_IRWXUGO,
2403 &proc_self_inode_operations, NULL, {}),
2404 };
2405
2406 /*
2407 * Exceptional case: normally we are not allowed to unhash a busy
2408 * directory. In this case, however, we can do it - no aliasing problems
2409 * due to the way we treat inodes.
2410 */
2411 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
2412 {
2413 struct inode *inode = dentry->d_inode;
2414 struct task_struct *task = get_proc_task(inode);
2415 if (task) {
2416 put_task_struct(task);
2417 return 1;
2418 }
2419 d_drop(dentry);
2420 return 0;
2421 }
2422
2423 static const struct dentry_operations proc_base_dentry_operations =
2424 {
2425 .d_revalidate = proc_base_revalidate,
2426 .d_delete = pid_delete_dentry,
2427 };
2428
2429 static struct dentry *proc_base_instantiate(struct inode *dir,
2430 struct dentry *dentry, struct task_struct *task, const void *ptr)
2431 {
2432 const struct pid_entry *p = ptr;
2433 struct inode *inode;
2434 struct proc_inode *ei;
2435 struct dentry *error;
2436
2437 /* Allocate the inode */
2438 error = ERR_PTR(-ENOMEM);
2439 inode = new_inode(dir->i_sb);
2440 if (!inode)
2441 goto out;
2442
2443 /* Initialize the inode */
2444 ei = PROC_I(inode);
2445 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2446
2447 /*
2448 * grab the reference to the task.
2449 */
2450 ei->pid = get_task_pid(task, PIDTYPE_PID);
2451 if (!ei->pid)
2452 goto out_iput;
2453
2454 inode->i_mode = p->mode;
2455 if (S_ISDIR(inode->i_mode))
2456 inode->i_nlink = 2;
2457 if (S_ISLNK(inode->i_mode))
2458 inode->i_size = 64;
2459 if (p->iop)
2460 inode->i_op = p->iop;
2461 if (p->fop)
2462 inode->i_fop = p->fop;
2463 ei->op = p->op;
2464 dentry->d_op = &proc_base_dentry_operations;
2465 d_add(dentry, inode);
2466 error = NULL;
2467 out:
2468 return error;
2469 out_iput:
2470 iput(inode);
2471 goto out;
2472 }
2473
2474 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2475 {
2476 struct dentry *error;
2477 struct task_struct *task = get_proc_task(dir);
2478 const struct pid_entry *p, *last;
2479
2480 error = ERR_PTR(-ENOENT);
2481
2482 if (!task)
2483 goto out_no_task;
2484
2485 /* Lookup the directory entry */
2486 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2487 for (p = proc_base_stuff; p <= last; p++) {
2488 if (p->len != dentry->d_name.len)
2489 continue;
2490 if (!memcmp(dentry->d_name.name, p->name, p->len))
2491 break;
2492 }
2493 if (p > last)
2494 goto out;
2495
2496 error = proc_base_instantiate(dir, dentry, task, p);
2497
2498 out:
2499 put_task_struct(task);
2500 out_no_task:
2501 return error;
2502 }
2503
2504 static int proc_base_fill_cache(struct file *filp, void *dirent,
2505 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2506 {
2507 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2508 proc_base_instantiate, task, p);
2509 }
2510
2511 #ifdef CONFIG_TASK_IO_ACCOUNTING
2512 static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2513 {
2514 struct task_io_accounting acct = task->ioac;
2515 unsigned long flags;
2516
2517 if (whole && lock_task_sighand(task, &flags)) {
2518 struct task_struct *t = task;
2519
2520 task_io_accounting_add(&acct, &task->signal->ioac);
2521 while_each_thread(task, t)
2522 task_io_accounting_add(&acct, &t->ioac);
2523
2524 unlock_task_sighand(task, &flags);
2525 }
2526 return sprintf(buffer,
2527 "rchar: %llu\n"
2528 "wchar: %llu\n"
2529 "syscr: %llu\n"
2530 "syscw: %llu\n"
2531 "read_bytes: %llu\n"
2532 "write_bytes: %llu\n"
2533 "cancelled_write_bytes: %llu\n",
2534 (unsigned long long)acct.rchar,
2535 (unsigned long long)acct.wchar,
2536 (unsigned long long)acct.syscr,
2537 (unsigned long long)acct.syscw,
2538 (unsigned long long)acct.read_bytes,
2539 (unsigned long long)acct.write_bytes,
2540 (unsigned long long)acct.cancelled_write_bytes);
2541 }
2542
2543 static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2544 {
2545 return do_io_accounting(task, buffer, 0);
2546 }
2547
2548 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2549 {
2550 return do_io_accounting(task, buffer, 1);
2551 }
2552 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2553
2554 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2555 struct pid *pid, struct task_struct *task)
2556 {
2557 seq_printf(m, "%08x\n", task->personality);
2558 return 0;
2559 }
2560
2561 /*
2562 * Thread groups
2563 */
2564 static const struct file_operations proc_task_operations;
2565 static const struct inode_operations proc_task_inode_operations;
2566
2567 static const struct pid_entry tgid_base_stuff[] = {
2568 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2569 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2570 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2571 #ifdef CONFIG_NET
2572 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2573 #endif
2574 REG("environ", S_IRUSR, proc_environ_operations),
2575 INF("auxv", S_IRUSR, proc_pid_auxv),
2576 ONE("status", S_IRUGO, proc_pid_status),
2577 ONE("personality", S_IRUSR, proc_pid_personality),
2578 INF("limits", S_IRUSR, proc_pid_limits),
2579 #ifdef CONFIG_SCHED_DEBUG
2580 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2581 #endif
2582 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2583 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2584 INF("syscall", S_IRUSR, proc_pid_syscall),
2585 #endif
2586 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2587 ONE("stat", S_IRUGO, proc_tgid_stat),
2588 ONE("statm", S_IRUGO, proc_pid_statm),
2589 REG("maps", S_IRUGO, proc_maps_operations),
2590 #ifdef CONFIG_NUMA
2591 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
2592 #endif
2593 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2594 LNK("cwd", proc_cwd_link),
2595 LNK("root", proc_root_link),
2596 LNK("exe", proc_exe_link),
2597 REG("mounts", S_IRUGO, proc_mounts_operations),
2598 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2599 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2600 #ifdef CONFIG_PROC_PAGE_MONITOR
2601 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2602 REG("smaps", S_IRUGO, proc_smaps_operations),
2603 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2604 #endif
2605 #ifdef CONFIG_SECURITY
2606 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2607 #endif
2608 #ifdef CONFIG_KALLSYMS
2609 INF("wchan", S_IRUGO, proc_pid_wchan),
2610 #endif
2611 #ifdef CONFIG_STACKTRACE
2612 ONE("stack", S_IRUSR, proc_pid_stack),
2613 #endif
2614 #ifdef CONFIG_SCHEDSTATS
2615 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2616 #endif
2617 #ifdef CONFIG_LATENCYTOP
2618 REG("latency", S_IRUGO, proc_lstats_operations),
2619 #endif
2620 #ifdef CONFIG_PROC_PID_CPUSET
2621 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2622 #endif
2623 #ifdef CONFIG_CGROUPS
2624 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2625 #endif
2626 INF("oom_score", S_IRUGO, proc_oom_score),
2627 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2628 #ifdef CONFIG_AUDITSYSCALL
2629 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2630 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2631 #endif
2632 #ifdef CONFIG_FAULT_INJECTION
2633 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2634 #endif
2635 #ifdef CONFIG_ELF_CORE
2636 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2637 #endif
2638 #ifdef CONFIG_TASK_IO_ACCOUNTING
2639 INF("io", S_IRUGO, proc_tgid_io_accounting),
2640 #endif
2641 };
2642
2643 static int proc_tgid_base_readdir(struct file * filp,
2644 void * dirent, filldir_t filldir)
2645 {
2646 return proc_pident_readdir(filp,dirent,filldir,
2647 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2648 }
2649
2650 static const struct file_operations proc_tgid_base_operations = {
2651 .read = generic_read_dir,
2652 .readdir = proc_tgid_base_readdir,
2653 };
2654
2655 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2656 return proc_pident_lookup(dir, dentry,
2657 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2658 }
2659
2660 static const struct inode_operations proc_tgid_base_inode_operations = {
2661 .lookup = proc_tgid_base_lookup,
2662 .getattr = pid_getattr,
2663 .setattr = proc_setattr,
2664 };
2665
2666 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2667 {
2668 struct dentry *dentry, *leader, *dir;
2669 char buf[PROC_NUMBUF];
2670 struct qstr name;
2671
2672 name.name = buf;
2673 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2674 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2675 if (dentry) {
2676 shrink_dcache_parent(dentry);
2677 d_drop(dentry);
2678 dput(dentry);
2679 }
2680
2681 name.name = buf;
2682 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2683 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2684 if (!leader)
2685 goto out;
2686
2687 name.name = "task";
2688 name.len = strlen(name.name);
2689 dir = d_hash_and_lookup(leader, &name);
2690 if (!dir)
2691 goto out_put_leader;
2692
2693 name.name = buf;
2694 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2695 dentry = d_hash_and_lookup(dir, &name);
2696 if (dentry) {
2697 shrink_dcache_parent(dentry);
2698 d_drop(dentry);
2699 dput(dentry);
2700 }
2701
2702 dput(dir);
2703 out_put_leader:
2704 dput(leader);
2705 out:
2706 return;
2707 }
2708
2709 /**
2710 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2711 * @task: task that should be flushed.
2712 *
2713 * When flushing dentries from proc, one needs to flush them from global
2714 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2715 * in. This call is supposed to do all of this job.
2716 *
2717 * Looks in the dcache for
2718 * /proc/@pid
2719 * /proc/@tgid/task/@pid
2720 * if either directory is present flushes it and all of it'ts children
2721 * from the dcache.
2722 *
2723 * It is safe and reasonable to cache /proc entries for a task until
2724 * that task exits. After that they just clog up the dcache with
2725 * useless entries, possibly causing useful dcache entries to be
2726 * flushed instead. This routine is proved to flush those useless
2727 * dcache entries at process exit time.
2728 *
2729 * NOTE: This routine is just an optimization so it does not guarantee
2730 * that no dcache entries will exist at process exit time it
2731 * just makes it very unlikely that any will persist.
2732 */
2733
2734 void proc_flush_task(struct task_struct *task)
2735 {
2736 int i;
2737 struct pid *pid, *tgid;
2738 struct upid *upid;
2739
2740 pid = task_pid(task);
2741 tgid = task_tgid(task);
2742
2743 for (i = 0; i <= pid->level; i++) {
2744 upid = &pid->numbers[i];
2745 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2746 tgid->numbers[i].nr);
2747 }
2748
2749 upid = &pid->numbers[pid->level];
2750 if (upid->nr == 1)
2751 pid_ns_release_proc(upid->ns);
2752 }
2753
2754 static struct dentry *proc_pid_instantiate(struct inode *dir,
2755 struct dentry * dentry,
2756 struct task_struct *task, const void *ptr)
2757 {
2758 struct dentry *error = ERR_PTR(-ENOENT);
2759 struct inode *inode;
2760
2761 inode = proc_pid_make_inode(dir->i_sb, task);
2762 if (!inode)
2763 goto out;
2764
2765 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2766 inode->i_op = &proc_tgid_base_inode_operations;
2767 inode->i_fop = &proc_tgid_base_operations;
2768 inode->i_flags|=S_IMMUTABLE;
2769
2770 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
2771 ARRAY_SIZE(tgid_base_stuff));
2772
2773 dentry->d_op = &pid_dentry_operations;
2774
2775 d_add(dentry, inode);
2776 /* Close the race of the process dying before we return the dentry */
2777 if (pid_revalidate(dentry, NULL))
2778 error = NULL;
2779 out:
2780 return error;
2781 }
2782
2783 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2784 {
2785 struct dentry *result;
2786 struct task_struct *task;
2787 unsigned tgid;
2788 struct pid_namespace *ns;
2789
2790 result = proc_base_lookup(dir, dentry);
2791 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
2792 goto out;
2793
2794 tgid = name_to_int(dentry);
2795 if (tgid == ~0U)
2796 goto out;
2797
2798 ns = dentry->d_sb->s_fs_info;
2799 rcu_read_lock();
2800 task = find_task_by_pid_ns(tgid, ns);
2801 if (task)
2802 get_task_struct(task);
2803 rcu_read_unlock();
2804 if (!task)
2805 goto out;
2806
2807 result = proc_pid_instantiate(dir, dentry, task, NULL);
2808 put_task_struct(task);
2809 out:
2810 return result;
2811 }
2812
2813 /*
2814 * Find the first task with tgid >= tgid
2815 *
2816 */
2817 struct tgid_iter {
2818 unsigned int tgid;
2819 struct task_struct *task;
2820 };
2821 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2822 {
2823 struct pid *pid;
2824
2825 if (iter.task)
2826 put_task_struct(iter.task);
2827 rcu_read_lock();
2828 retry:
2829 iter.task = NULL;
2830 pid = find_ge_pid(iter.tgid, ns);
2831 if (pid) {
2832 iter.tgid = pid_nr_ns(pid, ns);
2833 iter.task = pid_task(pid, PIDTYPE_PID);
2834 /* What we to know is if the pid we have find is the
2835 * pid of a thread_group_leader. Testing for task
2836 * being a thread_group_leader is the obvious thing
2837 * todo but there is a window when it fails, due to
2838 * the pid transfer logic in de_thread.
2839 *
2840 * So we perform the straight forward test of seeing
2841 * if the pid we have found is the pid of a thread
2842 * group leader, and don't worry if the task we have
2843 * found doesn't happen to be a thread group leader.
2844 * As we don't care in the case of readdir.
2845 */
2846 if (!iter.task || !has_group_leader_pid(iter.task)) {
2847 iter.tgid += 1;
2848 goto retry;
2849 }
2850 get_task_struct(iter.task);
2851 }
2852 rcu_read_unlock();
2853 return iter;
2854 }
2855
2856 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
2857
2858 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2859 struct tgid_iter iter)
2860 {
2861 char name[PROC_NUMBUF];
2862 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
2863 return proc_fill_cache(filp, dirent, filldir, name, len,
2864 proc_pid_instantiate, iter.task, NULL);
2865 }
2866
2867 /* for the /proc/ directory itself, after non-process stuff has been done */
2868 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2869 {
2870 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2871 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode);
2872 struct tgid_iter iter;
2873 struct pid_namespace *ns;
2874
2875 if (!reaper)
2876 goto out_no_task;
2877
2878 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
2879 const struct pid_entry *p = &proc_base_stuff[nr];
2880 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
2881 goto out;
2882 }
2883
2884 ns = filp->f_dentry->d_sb->s_fs_info;
2885 iter.task = NULL;
2886 iter.tgid = filp->f_pos - TGID_OFFSET;
2887 for (iter = next_tgid(ns, iter);
2888 iter.task;
2889 iter.tgid += 1, iter = next_tgid(ns, iter)) {
2890 filp->f_pos = iter.tgid + TGID_OFFSET;
2891 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
2892 put_task_struct(iter.task);
2893 goto out;
2894 }
2895 }
2896 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
2897 out:
2898 put_task_struct(reaper);
2899 out_no_task:
2900 return 0;
2901 }
2902
2903 /*
2904 * Tasks
2905 */
2906 static const struct pid_entry tid_base_stuff[] = {
2907 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2908 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2909 REG("environ", S_IRUSR, proc_environ_operations),
2910 INF("auxv", S_IRUSR, proc_pid_auxv),
2911 ONE("status", S_IRUGO, proc_pid_status),
2912 ONE("personality", S_IRUSR, proc_pid_personality),
2913 INF("limits", S_IRUSR, proc_pid_limits),
2914 #ifdef CONFIG_SCHED_DEBUG
2915 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2916 #endif
2917 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2918 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2919 INF("syscall", S_IRUSR, proc_pid_syscall),
2920 #endif
2921 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2922 ONE("stat", S_IRUGO, proc_tid_stat),
2923 ONE("statm", S_IRUGO, proc_pid_statm),
2924 REG("maps", S_IRUGO, proc_maps_operations),
2925 #ifdef CONFIG_NUMA
2926 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
2927 #endif
2928 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2929 LNK("cwd", proc_cwd_link),
2930 LNK("root", proc_root_link),
2931 LNK("exe", proc_exe_link),
2932 REG("mounts", S_IRUGO, proc_mounts_operations),
2933 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2934 #ifdef CONFIG_PROC_PAGE_MONITOR
2935 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2936 REG("smaps", S_IRUGO, proc_smaps_operations),
2937 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2938 #endif
2939 #ifdef CONFIG_SECURITY
2940 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2941 #endif
2942 #ifdef CONFIG_KALLSYMS
2943 INF("wchan", S_IRUGO, proc_pid_wchan),
2944 #endif
2945 #ifdef CONFIG_STACKTRACE
2946 ONE("stack", S_IRUSR, proc_pid_stack),
2947 #endif
2948 #ifdef CONFIG_SCHEDSTATS
2949 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2950 #endif
2951 #ifdef CONFIG_LATENCYTOP
2952 REG("latency", S_IRUGO, proc_lstats_operations),
2953 #endif
2954 #ifdef CONFIG_PROC_PID_CPUSET
2955 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2956 #endif
2957 #ifdef CONFIG_CGROUPS
2958 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2959 #endif
2960 INF("oom_score", S_IRUGO, proc_oom_score),
2961 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2962 #ifdef CONFIG_AUDITSYSCALL
2963 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2964 REG("sessionid", S_IRUSR, proc_sessionid_operations),
2965 #endif
2966 #ifdef CONFIG_FAULT_INJECTION
2967 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2968 #endif
2969 #ifdef CONFIG_TASK_IO_ACCOUNTING
2970 INF("io", S_IRUGO, proc_tid_io_accounting),
2971 #endif
2972 };
2973
2974 static int proc_tid_base_readdir(struct file * filp,
2975 void * dirent, filldir_t filldir)
2976 {
2977 return proc_pident_readdir(filp,dirent,filldir,
2978 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
2979 }
2980
2981 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2982 return proc_pident_lookup(dir, dentry,
2983 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
2984 }
2985
2986 static const struct file_operations proc_tid_base_operations = {
2987 .read = generic_read_dir,
2988 .readdir = proc_tid_base_readdir,
2989 };
2990
2991 static const struct inode_operations proc_tid_base_inode_operations = {
2992 .lookup = proc_tid_base_lookup,
2993 .getattr = pid_getattr,
2994 .setattr = proc_setattr,
2995 };
2996
2997 static struct dentry *proc_task_instantiate(struct inode *dir,
2998 struct dentry *dentry, struct task_struct *task, const void *ptr)
2999 {
3000 struct dentry *error = ERR_PTR(-ENOENT);
3001 struct inode *inode;
3002 inode = proc_pid_make_inode(dir->i_sb, task);
3003
3004 if (!inode)
3005 goto out;
3006 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3007 inode->i_op = &proc_tid_base_inode_operations;
3008 inode->i_fop = &proc_tid_base_operations;
3009 inode->i_flags|=S_IMMUTABLE;
3010
3011 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
3012 ARRAY_SIZE(tid_base_stuff));
3013
3014 dentry->d_op = &pid_dentry_operations;
3015
3016 d_add(dentry, inode);
3017 /* Close the race of the process dying before we return the dentry */
3018 if (pid_revalidate(dentry, NULL))
3019 error = NULL;
3020 out:
3021 return error;
3022 }
3023
3024 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3025 {
3026 struct dentry *result = ERR_PTR(-ENOENT);
3027 struct task_struct *task;
3028 struct task_struct *leader = get_proc_task(dir);
3029 unsigned tid;
3030 struct pid_namespace *ns;
3031
3032 if (!leader)
3033 goto out_no_task;
3034
3035 tid = name_to_int(dentry);
3036 if (tid == ~0U)
3037 goto out;
3038
3039 ns = dentry->d_sb->s_fs_info;
3040 rcu_read_lock();
3041 task = find_task_by_pid_ns(tid, ns);
3042 if (task)
3043 get_task_struct(task);
3044 rcu_read_unlock();
3045 if (!task)
3046 goto out;
3047 if (!same_thread_group(leader, task))
3048 goto out_drop_task;
3049
3050 result = proc_task_instantiate(dir, dentry, task, NULL);
3051 out_drop_task:
3052 put_task_struct(task);
3053 out:
3054 put_task_struct(leader);
3055 out_no_task:
3056 return result;
3057 }
3058
3059 /*
3060 * Find the first tid of a thread group to return to user space.
3061 *
3062 * Usually this is just the thread group leader, but if the users
3063 * buffer was too small or there was a seek into the middle of the
3064 * directory we have more work todo.
3065 *
3066 * In the case of a short read we start with find_task_by_pid.
3067 *
3068 * In the case of a seek we start with the leader and walk nr
3069 * threads past it.
3070 */
3071 static struct task_struct *first_tid(struct task_struct *leader,
3072 int tid, int nr, struct pid_namespace *ns)
3073 {
3074 struct task_struct *pos;
3075
3076 rcu_read_lock();
3077 /* Attempt to start with the pid of a thread */
3078 if (tid && (nr > 0)) {
3079 pos = find_task_by_pid_ns(tid, ns);
3080 if (pos && (pos->group_leader == leader))
3081 goto found;
3082 }
3083
3084 /* If nr exceeds the number of threads there is nothing todo */
3085 pos = NULL;
3086 if (nr && nr >= get_nr_threads(leader))
3087 goto out;
3088
3089 /* If we haven't found our starting place yet start
3090 * with the leader and walk nr threads forward.
3091 */
3092 for (pos = leader; nr > 0; --nr) {
3093 pos = next_thread(pos);
3094 if (pos == leader) {
3095 pos = NULL;
3096 goto out;
3097 }
3098 }
3099 found:
3100 get_task_struct(pos);
3101 out:
3102 rcu_read_unlock();
3103 return pos;
3104 }
3105
3106 /*
3107 * Find the next thread in the thread list.
3108 * Return NULL if there is an error or no next thread.
3109 *
3110 * The reference to the input task_struct is released.
3111 */
3112 static struct task_struct *next_tid(struct task_struct *start)
3113 {
3114 struct task_struct *pos = NULL;
3115 rcu_read_lock();
3116 if (pid_alive(start)) {
3117 pos = next_thread(start);
3118 if (thread_group_leader(pos))
3119 pos = NULL;
3120 else
3121 get_task_struct(pos);
3122 }
3123 rcu_read_unlock();
3124 put_task_struct(start);
3125 return pos;
3126 }
3127
3128 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3129 struct task_struct *task, int tid)
3130 {
3131 char name[PROC_NUMBUF];
3132 int len = snprintf(name, sizeof(name), "%d", tid);
3133 return proc_fill_cache(filp, dirent, filldir, name, len,
3134 proc_task_instantiate, task, NULL);
3135 }
3136
3137 /* for the /proc/TGID/task/ directories */
3138 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3139 {
3140 struct dentry *dentry = filp->f_path.dentry;
3141 struct inode *inode = dentry->d_inode;
3142 struct task_struct *leader = NULL;
3143 struct task_struct *task;
3144 int retval = -ENOENT;
3145 ino_t ino;
3146 int tid;
3147 struct pid_namespace *ns;
3148
3149 task = get_proc_task(inode);
3150 if (!task)
3151 goto out_no_task;
3152 rcu_read_lock();
3153 if (pid_alive(task)) {
3154 leader = task->group_leader;
3155 get_task_struct(leader);
3156 }
3157 rcu_read_unlock();
3158 put_task_struct(task);
3159 if (!leader)
3160 goto out_no_task;
3161 retval = 0;
3162
3163 switch ((unsigned long)filp->f_pos) {
3164 case 0:
3165 ino = inode->i_ino;
3166 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3167 goto out;
3168 filp->f_pos++;
3169 /* fall through */
3170 case 1:
3171 ino = parent_ino(dentry);
3172 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3173 goto out;
3174 filp->f_pos++;
3175 /* fall through */
3176 }
3177
3178 /* f_version caches the tgid value that the last readdir call couldn't
3179 * return. lseek aka telldir automagically resets f_version to 0.
3180 */
3181 ns = filp->f_dentry->d_sb->s_fs_info;
3182 tid = (int)filp->f_version;
3183 filp->f_version = 0;
3184 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3185 task;
3186 task = next_tid(task), filp->f_pos++) {
3187 tid = task_pid_nr_ns(task, ns);
3188 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3189 /* returning this tgid failed, save it as the first
3190 * pid for the next readir call */
3191 filp->f_version = (u64)tid;
3192 put_task_struct(task);
3193 break;
3194 }
3195 }
3196 out:
3197 put_task_struct(leader);
3198 out_no_task:
3199 return retval;
3200 }
3201
3202 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3203 {
3204 struct inode *inode = dentry->d_inode;
3205 struct task_struct *p = get_proc_task(inode);
3206 generic_fillattr(inode, stat);
3207
3208 if (p) {
3209 stat->nlink += get_nr_threads(p);
3210 put_task_struct(p);
3211 }
3212
3213 return 0;
3214 }
3215
3216 static const struct inode_operations proc_task_inode_operations = {
3217 .lookup = proc_task_lookup,
3218 .getattr = proc_task_getattr,
3219 .setattr = proc_setattr,
3220 };
3221
3222 static const struct file_operations proc_task_operations = {
3223 .read = generic_read_dir,
3224 .readdir = proc_task_readdir,
3225 };
Linux with added FPC-III support