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memcg: remove mem_cgroup_cal_reclaim()
[linux-2.6/next.git] / fs / proc / base.c
blob0c9de19a1633820856dae04bf71c21c3bed14da8
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 "internal.h"
84
85 /* NOTE:
86 * Implementing inode permission operations in /proc is almost
87 * certainly an error. Permission checks need to happen during
88 * each system call not at open time. The reason is that most of
89 * what we wish to check for permissions in /proc varies at runtime.
90 *
91 * The classic example of a problem is opening file descriptors
92 * in /proc for a task before it execs a suid executable.
93 */
94
95 struct pid_entry {
96 char *name;
97 int len;
98 mode_t mode;
99 const struct inode_operations *iop;
100 const struct file_operations *fop;
101 union proc_op op;
102 };
103
104 #define NOD(NAME, MODE, IOP, FOP, OP) { \
105 .name = (NAME), \
106 .len = sizeof(NAME) - 1, \
107 .mode = MODE, \
108 .iop = IOP, \
109 .fop = FOP, \
110 .op = OP, \
111 }
112
113 #define DIR(NAME, MODE, iops, fops) \
114 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
115 #define LNK(NAME, get_link) \
116 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
117 &proc_pid_link_inode_operations, NULL, \
118 { .proc_get_link = get_link } )
119 #define REG(NAME, MODE, fops) \
120 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
121 #define INF(NAME, MODE, read) \
122 NOD(NAME, (S_IFREG|(MODE)), \
123 NULL, &proc_info_file_operations, \
124 { .proc_read = read } )
125 #define ONE(NAME, MODE, show) \
126 NOD(NAME, (S_IFREG|(MODE)), \
127 NULL, &proc_single_file_operations, \
128 { .proc_show = show } )
129
130 /*
131 * Count the number of hardlinks for the pid_entry table, excluding the .
132 * and .. links.
133 */
134 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
135 unsigned int n)
136 {
137 unsigned int i;
138 unsigned int count;
139
140 count = 0;
141 for (i = 0; i < n; ++i) {
142 if (S_ISDIR(entries[i].mode))
143 ++count;
144 }
145
146 return count;
147 }
148
149 static struct fs_struct *get_fs_struct(struct task_struct *task)
150 {
151 struct fs_struct *fs;
152 task_lock(task);
153 fs = task->fs;
154 if(fs)
155 atomic_inc(&fs->count);
156 task_unlock(task);
157 return fs;
158 }
159
160 static int get_nr_threads(struct task_struct *tsk)
161 {
162 unsigned long flags;
163 int count = 0;
164
165 if (lock_task_sighand(tsk, &flags)) {
166 count = atomic_read(&tsk->signal->count);
167 unlock_task_sighand(tsk, &flags);
168 }
169 return count;
170 }
171
172 static int proc_cwd_link(struct inode *inode, struct path *path)
173 {
174 struct task_struct *task = get_proc_task(inode);
175 struct fs_struct *fs = NULL;
176 int result = -ENOENT;
177
178 if (task) {
179 fs = get_fs_struct(task);
180 put_task_struct(task);
181 }
182 if (fs) {
183 read_lock(&fs->lock);
184 *path = fs->pwd;
185 path_get(&fs->pwd);
186 read_unlock(&fs->lock);
187 result = 0;
188 put_fs_struct(fs);
189 }
190 return result;
191 }
192
193 static int proc_root_link(struct inode *inode, struct path *path)
194 {
195 struct task_struct *task = get_proc_task(inode);
196 struct fs_struct *fs = NULL;
197 int result = -ENOENT;
198
199 if (task) {
200 fs = get_fs_struct(task);
201 put_task_struct(task);
202 }
203 if (fs) {
204 read_lock(&fs->lock);
205 *path = fs->root;
206 path_get(&fs->root);
207 read_unlock(&fs->lock);
208 result = 0;
209 put_fs_struct(fs);
210 }
211 return result;
212 }
213
214 /*
215 * Return zero if current may access user memory in @task, -error if not.
216 */
217 static int check_mem_permission(struct task_struct *task)
218 {
219 /*
220 * A task can always look at itself, in case it chooses
221 * to use system calls instead of load instructions.
222 */
223 if (task == current)
224 return 0;
225
226 /*
227 * If current is actively ptrace'ing, and would also be
228 * permitted to freshly attach with ptrace now, permit it.
229 */
230 if (task_is_stopped_or_traced(task)) {
231 int match;
232 rcu_read_lock();
233 match = (tracehook_tracer_task(task) == current);
234 rcu_read_unlock();
235 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
236 return 0;
237 }
238
239 /*
240 * Noone else is allowed.
241 */
242 return -EPERM;
243 }
244
245 struct mm_struct *mm_for_maps(struct task_struct *task)
246 {
247 struct mm_struct *mm = get_task_mm(task);
248 if (!mm)
249 return NULL;
250 down_read(&mm->mmap_sem);
251 task_lock(task);
252 if (task->mm != mm)
253 goto out;
254 if (task->mm != current->mm &&
255 __ptrace_may_access(task, PTRACE_MODE_READ) < 0)
256 goto out;
257 task_unlock(task);
258 return mm;
259 out:
260 task_unlock(task);
261 up_read(&mm->mmap_sem);
262 mmput(mm);
263 return NULL;
264 }
265
266 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
267 {
268 int res = 0;
269 unsigned int len;
270 struct mm_struct *mm = get_task_mm(task);
271 if (!mm)
272 goto out;
273 if (!mm->arg_end)
274 goto out_mm; /* Shh! No looking before we're done */
275
276 len = mm->arg_end - mm->arg_start;
277
278 if (len > PAGE_SIZE)
279 len = PAGE_SIZE;
280
281 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
282
283 // If the nul at the end of args has been overwritten, then
284 // assume application is using setproctitle(3).
285 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
286 len = strnlen(buffer, res);
287 if (len < res) {
288 res = len;
289 } else {
290 len = mm->env_end - mm->env_start;
291 if (len > PAGE_SIZE - res)
292 len = PAGE_SIZE - res;
293 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
294 res = strnlen(buffer, res);
295 }
296 }
297 out_mm:
298 mmput(mm);
299 out:
300 return res;
301 }
302
303 static int proc_pid_auxv(struct task_struct *task, char *buffer)
304 {
305 int res = 0;
306 struct mm_struct *mm = get_task_mm(task);
307 if (mm) {
308 unsigned int nwords = 0;
309 do {
310 nwords += 2;
311 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
312 res = nwords * sizeof(mm->saved_auxv[0]);
313 if (res > PAGE_SIZE)
314 res = PAGE_SIZE;
315 memcpy(buffer, mm->saved_auxv, res);
316 mmput(mm);
317 }
318 return res;
319 }
320
321
322 #ifdef CONFIG_KALLSYMS
323 /*
324 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
325 * Returns the resolved symbol. If that fails, simply return the address.
326 */
327 static int proc_pid_wchan(struct task_struct *task, char *buffer)
328 {
329 unsigned long wchan;
330 char symname[KSYM_NAME_LEN];
331
332 wchan = get_wchan(task);
333
334 if (lookup_symbol_name(wchan, symname) < 0)
335 return sprintf(buffer, "%lu", wchan);
336 else
337 return sprintf(buffer, "%s", symname);
338 }
339 #endif /* CONFIG_KALLSYMS */
340
341 #ifdef CONFIG_STACKTRACE
342
343 #define MAX_STACK_TRACE_DEPTH 64
344
345 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
346 struct pid *pid, struct task_struct *task)
347 {
348 struct stack_trace trace;
349 unsigned long *entries;
350 int i;
351
352 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
353 if (!entries)
354 return -ENOMEM;
355
356 trace.nr_entries = 0;
357 trace.max_entries = MAX_STACK_TRACE_DEPTH;
358 trace.entries = entries;
359 trace.skip = 0;
360 save_stack_trace_tsk(task, &trace);
361
362 for (i = 0; i < trace.nr_entries; i++) {
363 seq_printf(m, "[<%p>] %pS\n",
364 (void *)entries[i], (void *)entries[i]);
365 }
366 kfree(entries);
367
368 return 0;
369 }
370 #endif
371
372 #ifdef CONFIG_SCHEDSTATS
373 /*
374 * Provides /proc/PID/schedstat
375 */
376 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
377 {
378 return sprintf(buffer, "%llu %llu %lu\n",
379 (unsigned long long)task->se.sum_exec_runtime,
380 (unsigned long long)task->sched_info.run_delay,
381 task->sched_info.pcount);
382 }
383 #endif
384
385 #ifdef CONFIG_LATENCYTOP
386 static int lstats_show_proc(struct seq_file *m, void *v)
387 {
388 int i;
389 struct inode *inode = m->private;
390 struct task_struct *task = get_proc_task(inode);
391
392 if (!task)
393 return -ESRCH;
394 seq_puts(m, "Latency Top version : v0.1\n");
395 for (i = 0; i < 32; i++) {
396 if (task->latency_record[i].backtrace[0]) {
397 int q;
398 seq_printf(m, "%i %li %li ",
399 task->latency_record[i].count,
400 task->latency_record[i].time,
401 task->latency_record[i].max);
402 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
403 char sym[KSYM_SYMBOL_LEN];
404 char *c;
405 if (!task->latency_record[i].backtrace[q])
406 break;
407 if (task->latency_record[i].backtrace[q] == ULONG_MAX)
408 break;
409 sprint_symbol(sym, task->latency_record[i].backtrace[q]);
410 c = strchr(sym, '+');
411 if (c)
412 *c = 0;
413 seq_printf(m, "%s ", sym);
414 }
415 seq_printf(m, "\n");
416 }
417
418 }
419 put_task_struct(task);
420 return 0;
421 }
422
423 static int lstats_open(struct inode *inode, struct file *file)
424 {
425 return single_open(file, lstats_show_proc, inode);
426 }
427
428 static ssize_t lstats_write(struct file *file, const char __user *buf,
429 size_t count, loff_t *offs)
430 {
431 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
432
433 if (!task)
434 return -ESRCH;
435 clear_all_latency_tracing(task);
436 put_task_struct(task);
437
438 return count;
439 }
440
441 static const struct file_operations proc_lstats_operations = {
442 .open = lstats_open,
443 .read = seq_read,
444 .write = lstats_write,
445 .llseek = seq_lseek,
446 .release = single_release,
447 };
448
449 #endif
450
451 /* The badness from the OOM killer */
452 unsigned long badness(struct task_struct *p, unsigned long uptime);
453 static int proc_oom_score(struct task_struct *task, char *buffer)
454 {
455 unsigned long points;
456 struct timespec uptime;
457
458 do_posix_clock_monotonic_gettime(&uptime);
459 read_lock(&tasklist_lock);
460 points = badness(task, uptime.tv_sec);
461 read_unlock(&tasklist_lock);
462 return sprintf(buffer, "%lu\n", points);
463 }
464
465 struct limit_names {
466 char *name;
467 char *unit;
468 };
469
470 static const struct limit_names lnames[RLIM_NLIMITS] = {
471 [RLIMIT_CPU] = {"Max cpu time", "ms"},
472 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
473 [RLIMIT_DATA] = {"Max data size", "bytes"},
474 [RLIMIT_STACK] = {"Max stack size", "bytes"},
475 [RLIMIT_CORE] = {"Max core file size", "bytes"},
476 [RLIMIT_RSS] = {"Max resident set", "bytes"},
477 [RLIMIT_NPROC] = {"Max processes", "processes"},
478 [RLIMIT_NOFILE] = {"Max open files", "files"},
479 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
480 [RLIMIT_AS] = {"Max address space", "bytes"},
481 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
482 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
483 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
484 [RLIMIT_NICE] = {"Max nice priority", NULL},
485 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
486 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
487 };
488
489 /* Display limits for a process */
490 static int proc_pid_limits(struct task_struct *task, char *buffer)
491 {
492 unsigned int i;
493 int count = 0;
494 unsigned long flags;
495 char *bufptr = buffer;
496
497 struct rlimit rlim[RLIM_NLIMITS];
498
499 if (!lock_task_sighand(task, &flags))
500 return 0;
501 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
502 unlock_task_sighand(task, &flags);
503
504 /*
505 * print the file header
506 */
507 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
508 "Limit", "Soft Limit", "Hard Limit", "Units");
509
510 for (i = 0; i < RLIM_NLIMITS; i++) {
511 if (rlim[i].rlim_cur == RLIM_INFINITY)
512 count += sprintf(&bufptr[count], "%-25s %-20s ",
513 lnames[i].name, "unlimited");
514 else
515 count += sprintf(&bufptr[count], "%-25s %-20lu ",
516 lnames[i].name, rlim[i].rlim_cur);
517
518 if (rlim[i].rlim_max == RLIM_INFINITY)
519 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
520 else
521 count += sprintf(&bufptr[count], "%-20lu ",
522 rlim[i].rlim_max);
523
524 if (lnames[i].unit)
525 count += sprintf(&bufptr[count], "%-10s\n",
526 lnames[i].unit);
527 else
528 count += sprintf(&bufptr[count], "\n");
529 }
530
531 return count;
532 }
533
534 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
535 static int proc_pid_syscall(struct task_struct *task, char *buffer)
536 {
537 long nr;
538 unsigned long args[6], sp, pc;
539
540 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
541 return sprintf(buffer, "running\n");
542
543 if (nr < 0)
544 return sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
545
546 return sprintf(buffer,
547 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
548 nr,
549 args[0], args[1], args[2], args[3], args[4], args[5],
550 sp, pc);
551 }
552 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
553
554 /************************************************************************/
555 /* Here the fs part begins */
556 /************************************************************************/
557
558 /* permission checks */
559 static int proc_fd_access_allowed(struct inode *inode)
560 {
561 struct task_struct *task;
562 int allowed = 0;
563 /* Allow access to a task's file descriptors if it is us or we
564 * may use ptrace attach to the process and find out that
565 * information.
566 */
567 task = get_proc_task(inode);
568 if (task) {
569 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
570 put_task_struct(task);
571 }
572 return allowed;
573 }
574
575 static int proc_setattr(struct dentry *dentry, struct iattr *attr)
576 {
577 int error;
578 struct inode *inode = dentry->d_inode;
579
580 if (attr->ia_valid & ATTR_MODE)
581 return -EPERM;
582
583 error = inode_change_ok(inode, attr);
584 if (!error)
585 error = inode_setattr(inode, attr);
586 return error;
587 }
588
589 static const struct inode_operations proc_def_inode_operations = {
590 .setattr = proc_setattr,
591 };
592
593 static int mounts_open_common(struct inode *inode, struct file *file,
594 const struct seq_operations *op)
595 {
596 struct task_struct *task = get_proc_task(inode);
597 struct nsproxy *nsp;
598 struct mnt_namespace *ns = NULL;
599 struct fs_struct *fs = NULL;
600 struct path root;
601 struct proc_mounts *p;
602 int ret = -EINVAL;
603
604 if (task) {
605 rcu_read_lock();
606 nsp = task_nsproxy(task);
607 if (nsp) {
608 ns = nsp->mnt_ns;
609 if (ns)
610 get_mnt_ns(ns);
611 }
612 rcu_read_unlock();
613 if (ns)
614 fs = get_fs_struct(task);
615 put_task_struct(task);
616 }
617
618 if (!ns)
619 goto err;
620 if (!fs)
621 goto err_put_ns;
622
623 read_lock(&fs->lock);
624 root = fs->root;
625 path_get(&root);
626 read_unlock(&fs->lock);
627 put_fs_struct(fs);
628
629 ret = -ENOMEM;
630 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
631 if (!p)
632 goto err_put_path;
633
634 file->private_data = &p->m;
635 ret = seq_open(file, op);
636 if (ret)
637 goto err_free;
638
639 p->m.private = p;
640 p->ns = ns;
641 p->root = root;
642 p->event = ns->event;
643
644 return 0;
645
646 err_free:
647 kfree(p);
648 err_put_path:
649 path_put(&root);
650 err_put_ns:
651 put_mnt_ns(ns);
652 err:
653 return ret;
654 }
655
656 static int mounts_release(struct inode *inode, struct file *file)
657 {
658 struct proc_mounts *p = file->private_data;
659 path_put(&p->root);
660 put_mnt_ns(p->ns);
661 return seq_release(inode, file);
662 }
663
664 static unsigned mounts_poll(struct file *file, poll_table *wait)
665 {
666 struct proc_mounts *p = file->private_data;
667 struct mnt_namespace *ns = p->ns;
668 unsigned res = 0;
669
670 poll_wait(file, &ns->poll, wait);
671
672 spin_lock(&vfsmount_lock);
673 if (p->event != ns->event) {
674 p->event = ns->event;
675 res = POLLERR;
676 }
677 spin_unlock(&vfsmount_lock);
678
679 return res;
680 }
681
682 static int mounts_open(struct inode *inode, struct file *file)
683 {
684 return mounts_open_common(inode, file, &mounts_op);
685 }
686
687 static const struct file_operations proc_mounts_operations = {
688 .open = mounts_open,
689 .read = seq_read,
690 .llseek = seq_lseek,
691 .release = mounts_release,
692 .poll = mounts_poll,
693 };
694
695 static int mountinfo_open(struct inode *inode, struct file *file)
696 {
697 return mounts_open_common(inode, file, &mountinfo_op);
698 }
699
700 static const struct file_operations proc_mountinfo_operations = {
701 .open = mountinfo_open,
702 .read = seq_read,
703 .llseek = seq_lseek,
704 .release = mounts_release,
705 .poll = mounts_poll,
706 };
707
708 static int mountstats_open(struct inode *inode, struct file *file)
709 {
710 return mounts_open_common(inode, file, &mountstats_op);
711 }
712
713 static const struct file_operations proc_mountstats_operations = {
714 .open = mountstats_open,
715 .read = seq_read,
716 .llseek = seq_lseek,
717 .release = mounts_release,
718 };
719
720 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
721
722 static ssize_t proc_info_read(struct file * file, char __user * buf,
723 size_t count, loff_t *ppos)
724 {
725 struct inode * inode = file->f_path.dentry->d_inode;
726 unsigned long page;
727 ssize_t length;
728 struct task_struct *task = get_proc_task(inode);
729
730 length = -ESRCH;
731 if (!task)
732 goto out_no_task;
733
734 if (count > PROC_BLOCK_SIZE)
735 count = PROC_BLOCK_SIZE;
736
737 length = -ENOMEM;
738 if (!(page = __get_free_page(GFP_TEMPORARY)))
739 goto out;
740
741 length = PROC_I(inode)->op.proc_read(task, (char*)page);
742
743 if (length >= 0)
744 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
745 free_page(page);
746 out:
747 put_task_struct(task);
748 out_no_task:
749 return length;
750 }
751
752 static const struct file_operations proc_info_file_operations = {
753 .read = proc_info_read,
754 };
755
756 static int proc_single_show(struct seq_file *m, void *v)
757 {
758 struct inode *inode = m->private;
759 struct pid_namespace *ns;
760 struct pid *pid;
761 struct task_struct *task;
762 int ret;
763
764 ns = inode->i_sb->s_fs_info;
765 pid = proc_pid(inode);
766 task = get_pid_task(pid, PIDTYPE_PID);
767 if (!task)
768 return -ESRCH;
769
770 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
771
772 put_task_struct(task);
773 return ret;
774 }
775
776 static int proc_single_open(struct inode *inode, struct file *filp)
777 {
778 int ret;
779 ret = single_open(filp, proc_single_show, NULL);
780 if (!ret) {
781 struct seq_file *m = filp->private_data;
782
783 m->private = inode;
784 }
785 return ret;
786 }
787
788 static const struct file_operations proc_single_file_operations = {
789 .open = proc_single_open,
790 .read = seq_read,
791 .llseek = seq_lseek,
792 .release = single_release,
793 };
794
795 static int mem_open(struct inode* inode, struct file* file)
796 {
797 file->private_data = (void*)((long)current->self_exec_id);
798 return 0;
799 }
800
801 static ssize_t mem_read(struct file * file, char __user * buf,
802 size_t count, loff_t *ppos)
803 {
804 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
805 char *page;
806 unsigned long src = *ppos;
807 int ret = -ESRCH;
808 struct mm_struct *mm;
809
810 if (!task)
811 goto out_no_task;
812
813 if (check_mem_permission(task))
814 goto out;
815
816 ret = -ENOMEM;
817 page = (char *)__get_free_page(GFP_TEMPORARY);
818 if (!page)
819 goto out;
820
821 ret = 0;
822
823 mm = get_task_mm(task);
824 if (!mm)
825 goto out_free;
826
827 ret = -EIO;
828
829 if (file->private_data != (void*)((long)current->self_exec_id))
830 goto out_put;
831
832 ret = 0;
833
834 while (count > 0) {
835 int this_len, retval;
836
837 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
838 retval = access_process_vm(task, src, page, this_len, 0);
839 if (!retval || check_mem_permission(task)) {
840 if (!ret)
841 ret = -EIO;
842 break;
843 }
844
845 if (copy_to_user(buf, page, retval)) {
846 ret = -EFAULT;
847 break;
848 }
849
850 ret += retval;
851 src += retval;
852 buf += retval;
853 count -= retval;
854 }
855 *ppos = src;
856
857 out_put:
858 mmput(mm);
859 out_free:
860 free_page((unsigned long) page);
861 out:
862 put_task_struct(task);
863 out_no_task:
864 return ret;
865 }
866
867 #define mem_write NULL
868
869 #ifndef mem_write
870 /* This is a security hazard */
871 static ssize_t mem_write(struct file * file, const char __user *buf,
872 size_t count, loff_t *ppos)
873 {
874 int copied;
875 char *page;
876 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
877 unsigned long dst = *ppos;
878
879 copied = -ESRCH;
880 if (!task)
881 goto out_no_task;
882
883 if (check_mem_permission(task))
884 goto out;
885
886 copied = -ENOMEM;
887 page = (char *)__get_free_page(GFP_TEMPORARY);
888 if (!page)
889 goto out;
890
891 copied = 0;
892 while (count > 0) {
893 int this_len, retval;
894
895 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
896 if (copy_from_user(page, buf, this_len)) {
897 copied = -EFAULT;
898 break;
899 }
900 retval = access_process_vm(task, dst, page, this_len, 1);
901 if (!retval) {
902 if (!copied)
903 copied = -EIO;
904 break;
905 }
906 copied += retval;
907 buf += retval;
908 dst += retval;
909 count -= retval;
910 }
911 *ppos = dst;
912 free_page((unsigned long) page);
913 out:
914 put_task_struct(task);
915 out_no_task:
916 return copied;
917 }
918 #endif
919
920 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
921 {
922 switch (orig) {
923 case 0:
924 file->f_pos = offset;
925 break;
926 case 1:
927 file->f_pos += offset;
928 break;
929 default:
930 return -EINVAL;
931 }
932 force_successful_syscall_return();
933 return file->f_pos;
934 }
935
936 static const struct file_operations proc_mem_operations = {
937 .llseek = mem_lseek,
938 .read = mem_read,
939 .write = mem_write,
940 .open = mem_open,
941 };
942
943 static ssize_t environ_read(struct file *file, char __user *buf,
944 size_t count, loff_t *ppos)
945 {
946 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
947 char *page;
948 unsigned long src = *ppos;
949 int ret = -ESRCH;
950 struct mm_struct *mm;
951
952 if (!task)
953 goto out_no_task;
954
955 if (!ptrace_may_access(task, PTRACE_MODE_READ))
956 goto out;
957
958 ret = -ENOMEM;
959 page = (char *)__get_free_page(GFP_TEMPORARY);
960 if (!page)
961 goto out;
962
963 ret = 0;
964
965 mm = get_task_mm(task);
966 if (!mm)
967 goto out_free;
968
969 while (count > 0) {
970 int this_len, retval, max_len;
971
972 this_len = mm->env_end - (mm->env_start + src);
973
974 if (this_len <= 0)
975 break;
976
977 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
978 this_len = (this_len > max_len) ? max_len : this_len;
979
980 retval = access_process_vm(task, (mm->env_start + src),
981 page, this_len, 0);
982
983 if (retval <= 0) {
984 ret = retval;
985 break;
986 }
987
988 if (copy_to_user(buf, page, retval)) {
989 ret = -EFAULT;
990 break;
991 }
992
993 ret += retval;
994 src += retval;
995 buf += retval;
996 count -= retval;
997 }
998 *ppos = src;
999
1000 mmput(mm);
1001 out_free:
1002 free_page((unsigned long) page);
1003 out:
1004 put_task_struct(task);
1005 out_no_task:
1006 return ret;
1007 }
1008
1009 static const struct file_operations proc_environ_operations = {
1010 .read = environ_read,
1011 };
1012
1013 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
1014 size_t count, loff_t *ppos)
1015 {
1016 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1017 char buffer[PROC_NUMBUF];
1018 size_t len;
1019 int oom_adjust;
1020
1021 if (!task)
1022 return -ESRCH;
1023 oom_adjust = task->oomkilladj;
1024 put_task_struct(task);
1025
1026 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
1027
1028 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1029 }
1030
1031 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
1032 size_t count, loff_t *ppos)
1033 {
1034 struct task_struct *task;
1035 char buffer[PROC_NUMBUF], *end;
1036 int oom_adjust;
1037
1038 memset(buffer, 0, sizeof(buffer));
1039 if (count > sizeof(buffer) - 1)
1040 count = sizeof(buffer) - 1;
1041 if (copy_from_user(buffer, buf, count))
1042 return -EFAULT;
1043 oom_adjust = simple_strtol(buffer, &end, 0);
1044 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
1045 oom_adjust != OOM_DISABLE)
1046 return -EINVAL;
1047 if (*end == '\n')
1048 end++;
1049 task = get_proc_task(file->f_path.dentry->d_inode);
1050 if (!task)
1051 return -ESRCH;
1052 if (oom_adjust < task->oomkilladj && !capable(CAP_SYS_RESOURCE)) {
1053 put_task_struct(task);
1054 return -EACCES;
1055 }
1056 task->oomkilladj = oom_adjust;
1057 put_task_struct(task);
1058 if (end - buffer == 0)
1059 return -EIO;
1060 return end - buffer;
1061 }
1062
1063 static const struct file_operations proc_oom_adjust_operations = {
1064 .read = oom_adjust_read,
1065 .write = oom_adjust_write,
1066 };
1067
1068 #ifdef CONFIG_AUDITSYSCALL
1069 #define TMPBUFLEN 21
1070 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1071 size_t count, loff_t *ppos)
1072 {
1073 struct inode * inode = file->f_path.dentry->d_inode;
1074 struct task_struct *task = get_proc_task(inode);
1075 ssize_t length;
1076 char tmpbuf[TMPBUFLEN];
1077
1078 if (!task)
1079 return -ESRCH;
1080 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1081 audit_get_loginuid(task));
1082 put_task_struct(task);
1083 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1084 }
1085
1086 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1087 size_t count, loff_t *ppos)
1088 {
1089 struct inode * inode = file->f_path.dentry->d_inode;
1090 char *page, *tmp;
1091 ssize_t length;
1092 uid_t loginuid;
1093
1094 if (!capable(CAP_AUDIT_CONTROL))
1095 return -EPERM;
1096
1097 if (current != pid_task(proc_pid(inode), PIDTYPE_PID))
1098 return -EPERM;
1099
1100 if (count >= PAGE_SIZE)
1101 count = PAGE_SIZE - 1;
1102
1103 if (*ppos != 0) {
1104 /* No partial writes. */
1105 return -EINVAL;
1106 }
1107 page = (char*)__get_free_page(GFP_TEMPORARY);
1108 if (!page)
1109 return -ENOMEM;
1110 length = -EFAULT;
1111 if (copy_from_user(page, buf, count))
1112 goto out_free_page;
1113
1114 page[count] = '\0';
1115 loginuid = simple_strtoul(page, &tmp, 10);
1116 if (tmp == page) {
1117 length = -EINVAL;
1118 goto out_free_page;
1119
1120 }
1121 length = audit_set_loginuid(current, loginuid);
1122 if (likely(length == 0))
1123 length = count;
1124
1125 out_free_page:
1126 free_page((unsigned long) page);
1127 return length;
1128 }
1129
1130 static const struct file_operations proc_loginuid_operations = {
1131 .read = proc_loginuid_read,
1132 .write = proc_loginuid_write,
1133 };
1134
1135 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1136 size_t count, loff_t *ppos)
1137 {
1138 struct inode * inode = file->f_path.dentry->d_inode;
1139 struct task_struct *task = get_proc_task(inode);
1140 ssize_t length;
1141 char tmpbuf[TMPBUFLEN];
1142
1143 if (!task)
1144 return -ESRCH;
1145 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1146 audit_get_sessionid(task));
1147 put_task_struct(task);
1148 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1149 }
1150
1151 static const struct file_operations proc_sessionid_operations = {
1152 .read = proc_sessionid_read,
1153 };
1154 #endif
1155
1156 #ifdef CONFIG_FAULT_INJECTION
1157 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1158 size_t count, loff_t *ppos)
1159 {
1160 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1161 char buffer[PROC_NUMBUF];
1162 size_t len;
1163 int make_it_fail;
1164
1165 if (!task)
1166 return -ESRCH;
1167 make_it_fail = task->make_it_fail;
1168 put_task_struct(task);
1169
1170 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1171
1172 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1173 }
1174
1175 static ssize_t proc_fault_inject_write(struct file * file,
1176 const char __user * buf, size_t count, loff_t *ppos)
1177 {
1178 struct task_struct *task;
1179 char buffer[PROC_NUMBUF], *end;
1180 int make_it_fail;
1181
1182 if (!capable(CAP_SYS_RESOURCE))
1183 return -EPERM;
1184 memset(buffer, 0, sizeof(buffer));
1185 if (count > sizeof(buffer) - 1)
1186 count = sizeof(buffer) - 1;
1187 if (copy_from_user(buffer, buf, count))
1188 return -EFAULT;
1189 make_it_fail = simple_strtol(buffer, &end, 0);
1190 if (*end == '\n')
1191 end++;
1192 task = get_proc_task(file->f_dentry->d_inode);
1193 if (!task)
1194 return -ESRCH;
1195 task->make_it_fail = make_it_fail;
1196 put_task_struct(task);
1197 if (end - buffer == 0)
1198 return -EIO;
1199 return end - buffer;
1200 }
1201
1202 static const struct file_operations proc_fault_inject_operations = {
1203 .read = proc_fault_inject_read,
1204 .write = proc_fault_inject_write,
1205 };
1206 #endif
1207
1208
1209 #ifdef CONFIG_SCHED_DEBUG
1210 /*
1211 * Print out various scheduling related per-task fields:
1212 */
1213 static int sched_show(struct seq_file *m, void *v)
1214 {
1215 struct inode *inode = m->private;
1216 struct task_struct *p;
1217
1218 p = get_proc_task(inode);
1219 if (!p)
1220 return -ESRCH;
1221 proc_sched_show_task(p, m);
1222
1223 put_task_struct(p);
1224
1225 return 0;
1226 }
1227
1228 static ssize_t
1229 sched_write(struct file *file, const char __user *buf,
1230 size_t count, loff_t *offset)
1231 {
1232 struct inode *inode = file->f_path.dentry->d_inode;
1233 struct task_struct *p;
1234
1235 p = get_proc_task(inode);
1236 if (!p)
1237 return -ESRCH;
1238 proc_sched_set_task(p);
1239
1240 put_task_struct(p);
1241
1242 return count;
1243 }
1244
1245 static int sched_open(struct inode *inode, struct file *filp)
1246 {
1247 int ret;
1248
1249 ret = single_open(filp, sched_show, NULL);
1250 if (!ret) {
1251 struct seq_file *m = filp->private_data;
1252
1253 m->private = inode;
1254 }
1255 return ret;
1256 }
1257
1258 static const struct file_operations proc_pid_sched_operations = {
1259 .open = sched_open,
1260 .read = seq_read,
1261 .write = sched_write,
1262 .llseek = seq_lseek,
1263 .release = single_release,
1264 };
1265
1266 #endif
1267
1268 /*
1269 * We added or removed a vma mapping the executable. The vmas are only mapped
1270 * during exec and are not mapped with the mmap system call.
1271 * Callers must hold down_write() on the mm's mmap_sem for these
1272 */
1273 void added_exe_file_vma(struct mm_struct *mm)
1274 {
1275 mm->num_exe_file_vmas++;
1276 }
1277
1278 void removed_exe_file_vma(struct mm_struct *mm)
1279 {
1280 mm->num_exe_file_vmas--;
1281 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){
1282 fput(mm->exe_file);
1283 mm->exe_file = NULL;
1284 }
1285
1286 }
1287
1288 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file)
1289 {
1290 if (new_exe_file)
1291 get_file(new_exe_file);
1292 if (mm->exe_file)
1293 fput(mm->exe_file);
1294 mm->exe_file = new_exe_file;
1295 mm->num_exe_file_vmas = 0;
1296 }
1297
1298 struct file *get_mm_exe_file(struct mm_struct *mm)
1299 {
1300 struct file *exe_file;
1301
1302 /* We need mmap_sem to protect against races with removal of
1303 * VM_EXECUTABLE vmas */
1304 down_read(&mm->mmap_sem);
1305 exe_file = mm->exe_file;
1306 if (exe_file)
1307 get_file(exe_file);
1308 up_read(&mm->mmap_sem);
1309 return exe_file;
1310 }
1311
1312 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm)
1313 {
1314 /* It's safe to write the exe_file pointer without exe_file_lock because
1315 * this is called during fork when the task is not yet in /proc */
1316 newmm->exe_file = get_mm_exe_file(oldmm);
1317 }
1318
1319 static int proc_exe_link(struct inode *inode, struct path *exe_path)
1320 {
1321 struct task_struct *task;
1322 struct mm_struct *mm;
1323 struct file *exe_file;
1324
1325 task = get_proc_task(inode);
1326 if (!task)
1327 return -ENOENT;
1328 mm = get_task_mm(task);
1329 put_task_struct(task);
1330 if (!mm)
1331 return -ENOENT;
1332 exe_file = get_mm_exe_file(mm);
1333 mmput(mm);
1334 if (exe_file) {
1335 *exe_path = exe_file->f_path;
1336 path_get(&exe_file->f_path);
1337 fput(exe_file);
1338 return 0;
1339 } else
1340 return -ENOENT;
1341 }
1342
1343 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1344 {
1345 struct inode *inode = dentry->d_inode;
1346 int error = -EACCES;
1347
1348 /* We don't need a base pointer in the /proc filesystem */
1349 path_put(&nd->path);
1350
1351 /* Are we allowed to snoop on the tasks file descriptors? */
1352 if (!proc_fd_access_allowed(inode))
1353 goto out;
1354
1355 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
1356 nd->last_type = LAST_BIND;
1357 out:
1358 return ERR_PTR(error);
1359 }
1360
1361 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1362 {
1363 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1364 char *pathname;
1365 int len;
1366
1367 if (!tmp)
1368 return -ENOMEM;
1369
1370 pathname = d_path(path, tmp, PAGE_SIZE);
1371 len = PTR_ERR(pathname);
1372 if (IS_ERR(pathname))
1373 goto out;
1374 len = tmp + PAGE_SIZE - 1 - pathname;
1375
1376 if (len > buflen)
1377 len = buflen;
1378 if (copy_to_user(buffer, pathname, len))
1379 len = -EFAULT;
1380 out:
1381 free_page((unsigned long)tmp);
1382 return len;
1383 }
1384
1385 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1386 {
1387 int error = -EACCES;
1388 struct inode *inode = dentry->d_inode;
1389 struct path path;
1390
1391 /* Are we allowed to snoop on the tasks file descriptors? */
1392 if (!proc_fd_access_allowed(inode))
1393 goto out;
1394
1395 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1396 if (error)
1397 goto out;
1398
1399 error = do_proc_readlink(&path, buffer, buflen);
1400 path_put(&path);
1401 out:
1402 return error;
1403 }
1404
1405 static const struct inode_operations proc_pid_link_inode_operations = {
1406 .readlink = proc_pid_readlink,
1407 .follow_link = proc_pid_follow_link,
1408 .setattr = proc_setattr,
1409 };
1410
1411
1412 /* building an inode */
1413
1414 static int task_dumpable(struct task_struct *task)
1415 {
1416 int dumpable = 0;
1417 struct mm_struct *mm;
1418
1419 task_lock(task);
1420 mm = task->mm;
1421 if (mm)
1422 dumpable = get_dumpable(mm);
1423 task_unlock(task);
1424 if(dumpable == 1)
1425 return 1;
1426 return 0;
1427 }
1428
1429
1430 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1431 {
1432 struct inode * inode;
1433 struct proc_inode *ei;
1434 const struct cred *cred;
1435
1436 /* We need a new inode */
1437
1438 inode = new_inode(sb);
1439 if (!inode)
1440 goto out;
1441
1442 /* Common stuff */
1443 ei = PROC_I(inode);
1444 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1445 inode->i_op = &proc_def_inode_operations;
1446
1447 /*
1448 * grab the reference to task.
1449 */
1450 ei->pid = get_task_pid(task, PIDTYPE_PID);
1451 if (!ei->pid)
1452 goto out_unlock;
1453
1454 if (task_dumpable(task)) {
1455 rcu_read_lock();
1456 cred = __task_cred(task);
1457 inode->i_uid = cred->euid;
1458 inode->i_gid = cred->egid;
1459 rcu_read_unlock();
1460 }
1461 security_task_to_inode(task, inode);
1462
1463 out:
1464 return inode;
1465
1466 out_unlock:
1467 iput(inode);
1468 return NULL;
1469 }
1470
1471 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1472 {
1473 struct inode *inode = dentry->d_inode;
1474 struct task_struct *task;
1475 const struct cred *cred;
1476
1477 generic_fillattr(inode, stat);
1478
1479 rcu_read_lock();
1480 stat->uid = 0;
1481 stat->gid = 0;
1482 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1483 if (task) {
1484 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1485 task_dumpable(task)) {
1486 cred = __task_cred(task);
1487 stat->uid = cred->euid;
1488 stat->gid = cred->egid;
1489 }
1490 }
1491 rcu_read_unlock();
1492 return 0;
1493 }
1494
1495 /* dentry stuff */
1496
1497 /*
1498 * Exceptional case: normally we are not allowed to unhash a busy
1499 * directory. In this case, however, we can do it - no aliasing problems
1500 * due to the way we treat inodes.
1501 *
1502 * Rewrite the inode's ownerships here because the owning task may have
1503 * performed a setuid(), etc.
1504 *
1505 * Before the /proc/pid/status file was created the only way to read
1506 * the effective uid of a /process was to stat /proc/pid. Reading
1507 * /proc/pid/status is slow enough that procps and other packages
1508 * kept stating /proc/pid. To keep the rules in /proc simple I have
1509 * made this apply to all per process world readable and executable
1510 * directories.
1511 */
1512 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1513 {
1514 struct inode *inode = dentry->d_inode;
1515 struct task_struct *task = get_proc_task(inode);
1516 const struct cred *cred;
1517
1518 if (task) {
1519 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1520 task_dumpable(task)) {
1521 rcu_read_lock();
1522 cred = __task_cred(task);
1523 inode->i_uid = cred->euid;
1524 inode->i_gid = cred->egid;
1525 rcu_read_unlock();
1526 } else {
1527 inode->i_uid = 0;
1528 inode->i_gid = 0;
1529 }
1530 inode->i_mode &= ~(S_ISUID | S_ISGID);
1531 security_task_to_inode(task, inode);
1532 put_task_struct(task);
1533 return 1;
1534 }
1535 d_drop(dentry);
1536 return 0;
1537 }
1538
1539 static int pid_delete_dentry(struct dentry * dentry)
1540 {
1541 /* Is the task we represent dead?
1542 * If so, then don't put the dentry on the lru list,
1543 * kill it immediately.
1544 */
1545 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1546 }
1547
1548 static struct dentry_operations pid_dentry_operations =
1549 {
1550 .d_revalidate = pid_revalidate,
1551 .d_delete = pid_delete_dentry,
1552 };
1553
1554 /* Lookups */
1555
1556 typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
1557 struct task_struct *, const void *);
1558
1559 /*
1560 * Fill a directory entry.
1561 *
1562 * If possible create the dcache entry and derive our inode number and
1563 * file type from dcache entry.
1564 *
1565 * Since all of the proc inode numbers are dynamically generated, the inode
1566 * numbers do not exist until the inode is cache. This means creating the
1567 * the dcache entry in readdir is necessary to keep the inode numbers
1568 * reported by readdir in sync with the inode numbers reported
1569 * by stat.
1570 */
1571 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1572 char *name, int len,
1573 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1574 {
1575 struct dentry *child, *dir = filp->f_path.dentry;
1576 struct inode *inode;
1577 struct qstr qname;
1578 ino_t ino = 0;
1579 unsigned type = DT_UNKNOWN;
1580
1581 qname.name = name;
1582 qname.len = len;
1583 qname.hash = full_name_hash(name, len);
1584
1585 child = d_lookup(dir, &qname);
1586 if (!child) {
1587 struct dentry *new;
1588 new = d_alloc(dir, &qname);
1589 if (new) {
1590 child = instantiate(dir->d_inode, new, task, ptr);
1591 if (child)
1592 dput(new);
1593 else
1594 child = new;
1595 }
1596 }
1597 if (!child || IS_ERR(child) || !child->d_inode)
1598 goto end_instantiate;
1599 inode = child->d_inode;
1600 if (inode) {
1601 ino = inode->i_ino;
1602 type = inode->i_mode >> 12;
1603 }
1604 dput(child);
1605 end_instantiate:
1606 if (!ino)
1607 ino = find_inode_number(dir, &qname);
1608 if (!ino)
1609 ino = 1;
1610 return filldir(dirent, name, len, filp->f_pos, ino, type);
1611 }
1612
1613 static unsigned name_to_int(struct dentry *dentry)
1614 {
1615 const char *name = dentry->d_name.name;
1616 int len = dentry->d_name.len;
1617 unsigned n = 0;
1618
1619 if (len > 1 && *name == '0')
1620 goto out;
1621 while (len-- > 0) {
1622 unsigned c = *name++ - '0';
1623 if (c > 9)
1624 goto out;
1625 if (n >= (~0U-9)/10)
1626 goto out;
1627 n *= 10;
1628 n += c;
1629 }
1630 return n;
1631 out:
1632 return ~0U;
1633 }
1634
1635 #define PROC_FDINFO_MAX 64
1636
1637 static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1638 {
1639 struct task_struct *task = get_proc_task(inode);
1640 struct files_struct *files = NULL;
1641 struct file *file;
1642 int fd = proc_fd(inode);
1643
1644 if (task) {
1645 files = get_files_struct(task);
1646 put_task_struct(task);
1647 }
1648 if (files) {
1649 /*
1650 * We are not taking a ref to the file structure, so we must
1651 * hold ->file_lock.
1652 */
1653 spin_lock(&files->file_lock);
1654 file = fcheck_files(files, fd);
1655 if (file) {
1656 if (path) {
1657 *path = file->f_path;
1658 path_get(&file->f_path);
1659 }
1660 if (info)
1661 snprintf(info, PROC_FDINFO_MAX,
1662 "pos:\t%lli\n"
1663 "flags:\t0%o\n",
1664 (long long) file->f_pos,
1665 file->f_flags);
1666 spin_unlock(&files->file_lock);
1667 put_files_struct(files);
1668 return 0;
1669 }
1670 spin_unlock(&files->file_lock);
1671 put_files_struct(files);
1672 }
1673 return -ENOENT;
1674 }
1675
1676 static int proc_fd_link(struct inode *inode, struct path *path)
1677 {
1678 return proc_fd_info(inode, path, NULL);
1679 }
1680
1681 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1682 {
1683 struct inode *inode = dentry->d_inode;
1684 struct task_struct *task = get_proc_task(inode);
1685 int fd = proc_fd(inode);
1686 struct files_struct *files;
1687 const struct cred *cred;
1688
1689 if (task) {
1690 files = get_files_struct(task);
1691 if (files) {
1692 rcu_read_lock();
1693 if (fcheck_files(files, fd)) {
1694 rcu_read_unlock();
1695 put_files_struct(files);
1696 if (task_dumpable(task)) {
1697 rcu_read_lock();
1698 cred = __task_cred(task);
1699 inode->i_uid = cred->euid;
1700 inode->i_gid = cred->egid;
1701 rcu_read_unlock();
1702 } else {
1703 inode->i_uid = 0;
1704 inode->i_gid = 0;
1705 }
1706 inode->i_mode &= ~(S_ISUID | S_ISGID);
1707 security_task_to_inode(task, inode);
1708 put_task_struct(task);
1709 return 1;
1710 }
1711 rcu_read_unlock();
1712 put_files_struct(files);
1713 }
1714 put_task_struct(task);
1715 }
1716 d_drop(dentry);
1717 return 0;
1718 }
1719
1720 static struct dentry_operations tid_fd_dentry_operations =
1721 {
1722 .d_revalidate = tid_fd_revalidate,
1723 .d_delete = pid_delete_dentry,
1724 };
1725
1726 static struct dentry *proc_fd_instantiate(struct inode *dir,
1727 struct dentry *dentry, struct task_struct *task, const void *ptr)
1728 {
1729 unsigned fd = *(const unsigned *)ptr;
1730 struct file *file;
1731 struct files_struct *files;
1732 struct inode *inode;
1733 struct proc_inode *ei;
1734 struct dentry *error = ERR_PTR(-ENOENT);
1735
1736 inode = proc_pid_make_inode(dir->i_sb, task);
1737 if (!inode)
1738 goto out;
1739 ei = PROC_I(inode);
1740 ei->fd = fd;
1741 files = get_files_struct(task);
1742 if (!files)
1743 goto out_iput;
1744 inode->i_mode = S_IFLNK;
1745
1746 /*
1747 * We are not taking a ref to the file structure, so we must
1748 * hold ->file_lock.
1749 */
1750 spin_lock(&files->file_lock);
1751 file = fcheck_files(files, fd);
1752 if (!file)
1753 goto out_unlock;
1754 if (file->f_mode & FMODE_READ)
1755 inode->i_mode |= S_IRUSR | S_IXUSR;
1756 if (file->f_mode & FMODE_WRITE)
1757 inode->i_mode |= S_IWUSR | S_IXUSR;
1758 spin_unlock(&files->file_lock);
1759 put_files_struct(files);
1760
1761 inode->i_op = &proc_pid_link_inode_operations;
1762 inode->i_size = 64;
1763 ei->op.proc_get_link = proc_fd_link;
1764 dentry->d_op = &tid_fd_dentry_operations;
1765 d_add(dentry, inode);
1766 /* Close the race of the process dying before we return the dentry */
1767 if (tid_fd_revalidate(dentry, NULL))
1768 error = NULL;
1769
1770 out:
1771 return error;
1772 out_unlock:
1773 spin_unlock(&files->file_lock);
1774 put_files_struct(files);
1775 out_iput:
1776 iput(inode);
1777 goto out;
1778 }
1779
1780 static struct dentry *proc_lookupfd_common(struct inode *dir,
1781 struct dentry *dentry,
1782 instantiate_t instantiate)
1783 {
1784 struct task_struct *task = get_proc_task(dir);
1785 unsigned fd = name_to_int(dentry);
1786 struct dentry *result = ERR_PTR(-ENOENT);
1787
1788 if (!task)
1789 goto out_no_task;
1790 if (fd == ~0U)
1791 goto out;
1792
1793 result = instantiate(dir, dentry, task, &fd);
1794 out:
1795 put_task_struct(task);
1796 out_no_task:
1797 return result;
1798 }
1799
1800 static int proc_readfd_common(struct file * filp, void * dirent,
1801 filldir_t filldir, instantiate_t instantiate)
1802 {
1803 struct dentry *dentry = filp->f_path.dentry;
1804 struct inode *inode = dentry->d_inode;
1805 struct task_struct *p = get_proc_task(inode);
1806 unsigned int fd, ino;
1807 int retval;
1808 struct files_struct * files;
1809
1810 retval = -ENOENT;
1811 if (!p)
1812 goto out_no_task;
1813 retval = 0;
1814
1815 fd = filp->f_pos;
1816 switch (fd) {
1817 case 0:
1818 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1819 goto out;
1820 filp->f_pos++;
1821 case 1:
1822 ino = parent_ino(dentry);
1823 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1824 goto out;
1825 filp->f_pos++;
1826 default:
1827 files = get_files_struct(p);
1828 if (!files)
1829 goto out;
1830 rcu_read_lock();
1831 for (fd = filp->f_pos-2;
1832 fd < files_fdtable(files)->max_fds;
1833 fd++, filp->f_pos++) {
1834 char name[PROC_NUMBUF];
1835 int len;
1836
1837 if (!fcheck_files(files, fd))
1838 continue;
1839 rcu_read_unlock();
1840
1841 len = snprintf(name, sizeof(name), "%d", fd);
1842 if (proc_fill_cache(filp, dirent, filldir,
1843 name, len, instantiate,
1844 p, &fd) < 0) {
1845 rcu_read_lock();
1846 break;
1847 }
1848 rcu_read_lock();
1849 }
1850 rcu_read_unlock();
1851 put_files_struct(files);
1852 }
1853 out:
1854 put_task_struct(p);
1855 out_no_task:
1856 return retval;
1857 }
1858
1859 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
1860 struct nameidata *nd)
1861 {
1862 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
1863 }
1864
1865 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
1866 {
1867 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
1868 }
1869
1870 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
1871 size_t len, loff_t *ppos)
1872 {
1873 char tmp[PROC_FDINFO_MAX];
1874 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
1875 if (!err)
1876 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
1877 return err;
1878 }
1879
1880 static const struct file_operations proc_fdinfo_file_operations = {
1881 .open = nonseekable_open,
1882 .read = proc_fdinfo_read,
1883 };
1884
1885 static const struct file_operations proc_fd_operations = {
1886 .read = generic_read_dir,
1887 .readdir = proc_readfd,
1888 };
1889
1890 /*
1891 * /proc/pid/fd needs a special permission handler so that a process can still
1892 * access /proc/self/fd after it has executed a setuid().
1893 */
1894 static int proc_fd_permission(struct inode *inode, int mask)
1895 {
1896 int rv;
1897
1898 rv = generic_permission(inode, mask, NULL);
1899 if (rv == 0)
1900 return 0;
1901 if (task_pid(current) == proc_pid(inode))
1902 rv = 0;
1903 return rv;
1904 }
1905
1906 /*
1907 * proc directories can do almost nothing..
1908 */
1909 static const struct inode_operations proc_fd_inode_operations = {
1910 .lookup = proc_lookupfd,
1911 .permission = proc_fd_permission,
1912 .setattr = proc_setattr,
1913 };
1914
1915 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
1916 struct dentry *dentry, struct task_struct *task, const void *ptr)
1917 {
1918 unsigned fd = *(unsigned *)ptr;
1919 struct inode *inode;
1920 struct proc_inode *ei;
1921 struct dentry *error = ERR_PTR(-ENOENT);
1922
1923 inode = proc_pid_make_inode(dir->i_sb, task);
1924 if (!inode)
1925 goto out;
1926 ei = PROC_I(inode);
1927 ei->fd = fd;
1928 inode->i_mode = S_IFREG | S_IRUSR;
1929 inode->i_fop = &proc_fdinfo_file_operations;
1930 dentry->d_op = &tid_fd_dentry_operations;
1931 d_add(dentry, inode);
1932 /* Close the race of the process dying before we return the dentry */
1933 if (tid_fd_revalidate(dentry, NULL))
1934 error = NULL;
1935
1936 out:
1937 return error;
1938 }
1939
1940 static struct dentry *proc_lookupfdinfo(struct inode *dir,
1941 struct dentry *dentry,
1942 struct nameidata *nd)
1943 {
1944 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
1945 }
1946
1947 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
1948 {
1949 return proc_readfd_common(filp, dirent, filldir,
1950 proc_fdinfo_instantiate);
1951 }
1952
1953 static const struct file_operations proc_fdinfo_operations = {
1954 .read = generic_read_dir,
1955 .readdir = proc_readfdinfo,
1956 };
1957
1958 /*
1959 * proc directories can do almost nothing..
1960 */
1961 static const struct inode_operations proc_fdinfo_inode_operations = {
1962 .lookup = proc_lookupfdinfo,
1963 .setattr = proc_setattr,
1964 };
1965
1966
1967 static struct dentry *proc_pident_instantiate(struct inode *dir,
1968 struct dentry *dentry, struct task_struct *task, const void *ptr)
1969 {
1970 const struct pid_entry *p = ptr;
1971 struct inode *inode;
1972 struct proc_inode *ei;
1973 struct dentry *error = ERR_PTR(-EINVAL);
1974
1975 inode = proc_pid_make_inode(dir->i_sb, task);
1976 if (!inode)
1977 goto out;
1978
1979 ei = PROC_I(inode);
1980 inode->i_mode = p->mode;
1981 if (S_ISDIR(inode->i_mode))
1982 inode->i_nlink = 2; /* Use getattr to fix if necessary */
1983 if (p->iop)
1984 inode->i_op = p->iop;
1985 if (p->fop)
1986 inode->i_fop = p->fop;
1987 ei->op = p->op;
1988 dentry->d_op = &pid_dentry_operations;
1989 d_add(dentry, inode);
1990 /* Close the race of the process dying before we return the dentry */
1991 if (pid_revalidate(dentry, NULL))
1992 error = NULL;
1993 out:
1994 return error;
1995 }
1996
1997 static struct dentry *proc_pident_lookup(struct inode *dir,
1998 struct dentry *dentry,
1999 const struct pid_entry *ents,
2000 unsigned int nents)
2001 {
2002 struct dentry *error;
2003 struct task_struct *task = get_proc_task(dir);
2004 const struct pid_entry *p, *last;
2005
2006 error = ERR_PTR(-ENOENT);
2007
2008 if (!task)
2009 goto out_no_task;
2010
2011 /*
2012 * Yes, it does not scale. And it should not. Don't add
2013 * new entries into /proc/<tgid>/ without very good reasons.
2014 */
2015 last = &ents[nents - 1];
2016 for (p = ents; p <= last; p++) {
2017 if (p->len != dentry->d_name.len)
2018 continue;
2019 if (!memcmp(dentry->d_name.name, p->name, p->len))
2020 break;
2021 }
2022 if (p > last)
2023 goto out;
2024
2025 error = proc_pident_instantiate(dir, dentry, task, p);
2026 out:
2027 put_task_struct(task);
2028 out_no_task:
2029 return error;
2030 }
2031
2032 static int proc_pident_fill_cache(struct file *filp, void *dirent,
2033 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2034 {
2035 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2036 proc_pident_instantiate, task, p);
2037 }
2038
2039 static int proc_pident_readdir(struct file *filp,
2040 void *dirent, filldir_t filldir,
2041 const struct pid_entry *ents, unsigned int nents)
2042 {
2043 int i;
2044 struct dentry *dentry = filp->f_path.dentry;
2045 struct inode *inode = dentry->d_inode;
2046 struct task_struct *task = get_proc_task(inode);
2047 const struct pid_entry *p, *last;
2048 ino_t ino;
2049 int ret;
2050
2051 ret = -ENOENT;
2052 if (!task)
2053 goto out_no_task;
2054
2055 ret = 0;
2056 i = filp->f_pos;
2057 switch (i) {
2058 case 0:
2059 ino = inode->i_ino;
2060 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2061 goto out;
2062 i++;
2063 filp->f_pos++;
2064 /* fall through */
2065 case 1:
2066 ino = parent_ino(dentry);
2067 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2068 goto out;
2069 i++;
2070 filp->f_pos++;
2071 /* fall through */
2072 default:
2073 i -= 2;
2074 if (i >= nents) {
2075 ret = 1;
2076 goto out;
2077 }
2078 p = ents + i;
2079 last = &ents[nents - 1];
2080 while (p <= last) {
2081 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2082 goto out;
2083 filp->f_pos++;
2084 p++;
2085 }
2086 }
2087
2088 ret = 1;
2089 out:
2090 put_task_struct(task);
2091 out_no_task:
2092 return ret;
2093 }
2094
2095 #ifdef CONFIG_SECURITY
2096 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2097 size_t count, loff_t *ppos)
2098 {
2099 struct inode * inode = file->f_path.dentry->d_inode;
2100 char *p = NULL;
2101 ssize_t length;
2102 struct task_struct *task = get_proc_task(inode);
2103
2104 if (!task)
2105 return -ESRCH;
2106
2107 length = security_getprocattr(task,
2108 (char*)file->f_path.dentry->d_name.name,
2109 &p);
2110 put_task_struct(task);
2111 if (length > 0)
2112 length = simple_read_from_buffer(buf, count, ppos, p, length);
2113 kfree(p);
2114 return length;
2115 }
2116
2117 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2118 size_t count, loff_t *ppos)
2119 {
2120 struct inode * inode = file->f_path.dentry->d_inode;
2121 char *page;
2122 ssize_t length;
2123 struct task_struct *task = get_proc_task(inode);
2124
2125 length = -ESRCH;
2126 if (!task)
2127 goto out_no_task;
2128 if (count > PAGE_SIZE)
2129 count = PAGE_SIZE;
2130
2131 /* No partial writes. */
2132 length = -EINVAL;
2133 if (*ppos != 0)
2134 goto out;
2135
2136 length = -ENOMEM;
2137 page = (char*)__get_free_page(GFP_TEMPORARY);
2138 if (!page)
2139 goto out;
2140
2141 length = -EFAULT;
2142 if (copy_from_user(page, buf, count))
2143 goto out_free;
2144
2145 length = security_setprocattr(task,
2146 (char*)file->f_path.dentry->d_name.name,
2147 (void*)page, count);
2148 out_free:
2149 free_page((unsigned long) page);
2150 out:
2151 put_task_struct(task);
2152 out_no_task:
2153 return length;
2154 }
2155
2156 static const struct file_operations proc_pid_attr_operations = {
2157 .read = proc_pid_attr_read,
2158 .write = proc_pid_attr_write,
2159 };
2160
2161 static const struct pid_entry attr_dir_stuff[] = {
2162 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2163 REG("prev", S_IRUGO, proc_pid_attr_operations),
2164 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2165 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2166 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2167 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2168 };
2169
2170 static int proc_attr_dir_readdir(struct file * filp,
2171 void * dirent, filldir_t filldir)
2172 {
2173 return proc_pident_readdir(filp,dirent,filldir,
2174 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2175 }
2176
2177 static const struct file_operations proc_attr_dir_operations = {
2178 .read = generic_read_dir,
2179 .readdir = proc_attr_dir_readdir,
2180 };
2181
2182 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2183 struct dentry *dentry, struct nameidata *nd)
2184 {
2185 return proc_pident_lookup(dir, dentry,
2186 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2187 }
2188
2189 static const struct inode_operations proc_attr_dir_inode_operations = {
2190 .lookup = proc_attr_dir_lookup,
2191 .getattr = pid_getattr,
2192 .setattr = proc_setattr,
2193 };
2194
2195 #endif
2196
2197 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
2198 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2199 size_t count, loff_t *ppos)
2200 {
2201 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2202 struct mm_struct *mm;
2203 char buffer[PROC_NUMBUF];
2204 size_t len;
2205 int ret;
2206
2207 if (!task)
2208 return -ESRCH;
2209
2210 ret = 0;
2211 mm = get_task_mm(task);
2212 if (mm) {
2213 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2214 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2215 MMF_DUMP_FILTER_SHIFT));
2216 mmput(mm);
2217 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2218 }
2219
2220 put_task_struct(task);
2221
2222 return ret;
2223 }
2224
2225 static ssize_t proc_coredump_filter_write(struct file *file,
2226 const char __user *buf,
2227 size_t count,
2228 loff_t *ppos)
2229 {
2230 struct task_struct *task;
2231 struct mm_struct *mm;
2232 char buffer[PROC_NUMBUF], *end;
2233 unsigned int val;
2234 int ret;
2235 int i;
2236 unsigned long mask;
2237
2238 ret = -EFAULT;
2239 memset(buffer, 0, sizeof(buffer));
2240 if (count > sizeof(buffer) - 1)
2241 count = sizeof(buffer) - 1;
2242 if (copy_from_user(buffer, buf, count))
2243 goto out_no_task;
2244
2245 ret = -EINVAL;
2246 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2247 if (*end == '\n')
2248 end++;
2249 if (end - buffer == 0)
2250 goto out_no_task;
2251
2252 ret = -ESRCH;
2253 task = get_proc_task(file->f_dentry->d_inode);
2254 if (!task)
2255 goto out_no_task;
2256
2257 ret = end - buffer;
2258 mm = get_task_mm(task);
2259 if (!mm)
2260 goto out_no_mm;
2261
2262 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2263 if (val & mask)
2264 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2265 else
2266 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2267 }
2268
2269 mmput(mm);
2270 out_no_mm:
2271 put_task_struct(task);
2272 out_no_task:
2273 return ret;
2274 }
2275
2276 static const struct file_operations proc_coredump_filter_operations = {
2277 .read = proc_coredump_filter_read,
2278 .write = proc_coredump_filter_write,
2279 };
2280 #endif
2281
2282 /*
2283 * /proc/self:
2284 */
2285 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2286 int buflen)
2287 {
2288 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2289 pid_t tgid = task_tgid_nr_ns(current, ns);
2290 char tmp[PROC_NUMBUF];
2291 if (!tgid)
2292 return -ENOENT;
2293 sprintf(tmp, "%d", tgid);
2294 return vfs_readlink(dentry,buffer,buflen,tmp);
2295 }
2296
2297 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2298 {
2299 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2300 pid_t tgid = task_tgid_nr_ns(current, ns);
2301 char tmp[PROC_NUMBUF];
2302 if (!tgid)
2303 return ERR_PTR(-ENOENT);
2304 sprintf(tmp, "%d", task_tgid_nr_ns(current, ns));
2305 return ERR_PTR(vfs_follow_link(nd,tmp));
2306 }
2307
2308 static const struct inode_operations proc_self_inode_operations = {
2309 .readlink = proc_self_readlink,
2310 .follow_link = proc_self_follow_link,
2311 };
2312
2313 /*
2314 * proc base
2315 *
2316 * These are the directory entries in the root directory of /proc
2317 * that properly belong to the /proc filesystem, as they describe
2318 * describe something that is process related.
2319 */
2320 static const struct pid_entry proc_base_stuff[] = {
2321 NOD("self", S_IFLNK|S_IRWXUGO,
2322 &proc_self_inode_operations, NULL, {}),
2323 };
2324
2325 /*
2326 * Exceptional case: normally we are not allowed to unhash a busy
2327 * directory. In this case, however, we can do it - no aliasing problems
2328 * due to the way we treat inodes.
2329 */
2330 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
2331 {
2332 struct inode *inode = dentry->d_inode;
2333 struct task_struct *task = get_proc_task(inode);
2334 if (task) {
2335 put_task_struct(task);
2336 return 1;
2337 }
2338 d_drop(dentry);
2339 return 0;
2340 }
2341
2342 static struct dentry_operations proc_base_dentry_operations =
2343 {
2344 .d_revalidate = proc_base_revalidate,
2345 .d_delete = pid_delete_dentry,
2346 };
2347
2348 static struct dentry *proc_base_instantiate(struct inode *dir,
2349 struct dentry *dentry, struct task_struct *task, const void *ptr)
2350 {
2351 const struct pid_entry *p = ptr;
2352 struct inode *inode;
2353 struct proc_inode *ei;
2354 struct dentry *error = ERR_PTR(-EINVAL);
2355
2356 /* Allocate the inode */
2357 error = ERR_PTR(-ENOMEM);
2358 inode = new_inode(dir->i_sb);
2359 if (!inode)
2360 goto out;
2361
2362 /* Initialize the inode */
2363 ei = PROC_I(inode);
2364 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2365
2366 /*
2367 * grab the reference to the task.
2368 */
2369 ei->pid = get_task_pid(task, PIDTYPE_PID);
2370 if (!ei->pid)
2371 goto out_iput;
2372
2373 inode->i_mode = p->mode;
2374 if (S_ISDIR(inode->i_mode))
2375 inode->i_nlink = 2;
2376 if (S_ISLNK(inode->i_mode))
2377 inode->i_size = 64;
2378 if (p->iop)
2379 inode->i_op = p->iop;
2380 if (p->fop)
2381 inode->i_fop = p->fop;
2382 ei->op = p->op;
2383 dentry->d_op = &proc_base_dentry_operations;
2384 d_add(dentry, inode);
2385 error = NULL;
2386 out:
2387 return error;
2388 out_iput:
2389 iput(inode);
2390 goto out;
2391 }
2392
2393 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2394 {
2395 struct dentry *error;
2396 struct task_struct *task = get_proc_task(dir);
2397 const struct pid_entry *p, *last;
2398
2399 error = ERR_PTR(-ENOENT);
2400
2401 if (!task)
2402 goto out_no_task;
2403
2404 /* Lookup the directory entry */
2405 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2406 for (p = proc_base_stuff; p <= last; p++) {
2407 if (p->len != dentry->d_name.len)
2408 continue;
2409 if (!memcmp(dentry->d_name.name, p->name, p->len))
2410 break;
2411 }
2412 if (p > last)
2413 goto out;
2414
2415 error = proc_base_instantiate(dir, dentry, task, p);
2416
2417 out:
2418 put_task_struct(task);
2419 out_no_task:
2420 return error;
2421 }
2422
2423 static int proc_base_fill_cache(struct file *filp, void *dirent,
2424 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2425 {
2426 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2427 proc_base_instantiate, task, p);
2428 }
2429
2430 #ifdef CONFIG_TASK_IO_ACCOUNTING
2431 static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2432 {
2433 struct task_io_accounting acct = task->ioac;
2434 unsigned long flags;
2435
2436 if (whole && lock_task_sighand(task, &flags)) {
2437 struct task_struct *t = task;
2438
2439 task_io_accounting_add(&acct, &task->signal->ioac);
2440 while_each_thread(task, t)
2441 task_io_accounting_add(&acct, &t->ioac);
2442
2443 unlock_task_sighand(task, &flags);
2444 }
2445 return sprintf(buffer,
2446 "rchar: %llu\n"
2447 "wchar: %llu\n"
2448 "syscr: %llu\n"
2449 "syscw: %llu\n"
2450 "read_bytes: %llu\n"
2451 "write_bytes: %llu\n"
2452 "cancelled_write_bytes: %llu\n",
2453 (unsigned long long)acct.rchar,
2454 (unsigned long long)acct.wchar,
2455 (unsigned long long)acct.syscr,
2456 (unsigned long long)acct.syscw,
2457 (unsigned long long)acct.read_bytes,
2458 (unsigned long long)acct.write_bytes,
2459 (unsigned long long)acct.cancelled_write_bytes);
2460 }
2461
2462 static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2463 {
2464 return do_io_accounting(task, buffer, 0);
2465 }
2466
2467 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2468 {
2469 return do_io_accounting(task, buffer, 1);
2470 }
2471 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2472
2473 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2474 struct pid *pid, struct task_struct *task)
2475 {
2476 seq_printf(m, "%08x\n", task->personality);
2477 return 0;
2478 }
2479
2480 /*
2481 * Thread groups
2482 */
2483 static const struct file_operations proc_task_operations;
2484 static const struct inode_operations proc_task_inode_operations;
2485
2486 static const struct pid_entry tgid_base_stuff[] = {
2487 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2488 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2489 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2490 #ifdef CONFIG_NET
2491 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2492 #endif
2493 REG("environ", S_IRUSR, proc_environ_operations),
2494 INF("auxv", S_IRUSR, proc_pid_auxv),
2495 ONE("status", S_IRUGO, proc_pid_status),
2496 ONE("personality", S_IRUSR, proc_pid_personality),
2497 INF("limits", S_IRUSR, proc_pid_limits),
2498 #ifdef CONFIG_SCHED_DEBUG
2499 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2500 #endif
2501 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2502 INF("syscall", S_IRUSR, proc_pid_syscall),
2503 #endif
2504 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2505 ONE("stat", S_IRUGO, proc_tgid_stat),
2506 ONE("statm", S_IRUGO, proc_pid_statm),
2507 REG("maps", S_IRUGO, proc_maps_operations),
2508 #ifdef CONFIG_NUMA
2509 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
2510 #endif
2511 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2512 LNK("cwd", proc_cwd_link),
2513 LNK("root", proc_root_link),
2514 LNK("exe", proc_exe_link),
2515 REG("mounts", S_IRUGO, proc_mounts_operations),
2516 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2517 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2518 #ifdef CONFIG_PROC_PAGE_MONITOR
2519 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2520 REG("smaps", S_IRUGO, proc_smaps_operations),
2521 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2522 #endif
2523 #ifdef CONFIG_SECURITY
2524 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2525 #endif
2526 #ifdef CONFIG_KALLSYMS
2527 INF("wchan", S_IRUGO, proc_pid_wchan),
2528 #endif
2529 #ifdef CONFIG_STACKTRACE
2530 ONE("stack", S_IRUSR, proc_pid_stack),
2531 #endif
2532 #ifdef CONFIG_SCHEDSTATS
2533 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2534 #endif
2535 #ifdef CONFIG_LATENCYTOP
2536 REG("latency", S_IRUGO, proc_lstats_operations),
2537 #endif
2538 #ifdef CONFIG_PROC_PID_CPUSET
2539 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2540 #endif
2541 #ifdef CONFIG_CGROUPS
2542 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2543 #endif
2544 INF("oom_score", S_IRUGO, proc_oom_score),
2545 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2546 #ifdef CONFIG_AUDITSYSCALL
2547 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2548 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2549 #endif
2550 #ifdef CONFIG_FAULT_INJECTION
2551 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2552 #endif
2553 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
2554 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2555 #endif
2556 #ifdef CONFIG_TASK_IO_ACCOUNTING
2557 INF("io", S_IRUGO, proc_tgid_io_accounting),
2558 #endif
2559 };
2560
2561 static int proc_tgid_base_readdir(struct file * filp,
2562 void * dirent, filldir_t filldir)
2563 {
2564 return proc_pident_readdir(filp,dirent,filldir,
2565 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2566 }
2567
2568 static const struct file_operations proc_tgid_base_operations = {
2569 .read = generic_read_dir,
2570 .readdir = proc_tgid_base_readdir,
2571 };
2572
2573 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2574 return proc_pident_lookup(dir, dentry,
2575 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2576 }
2577
2578 static const struct inode_operations proc_tgid_base_inode_operations = {
2579 .lookup = proc_tgid_base_lookup,
2580 .getattr = pid_getattr,
2581 .setattr = proc_setattr,
2582 };
2583
2584 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2585 {
2586 struct dentry *dentry, *leader, *dir;
2587 char buf[PROC_NUMBUF];
2588 struct qstr name;
2589
2590 name.name = buf;
2591 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2592 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2593 if (dentry) {
2594 if (!(current->flags & PF_EXITING))
2595 shrink_dcache_parent(dentry);
2596 d_drop(dentry);
2597 dput(dentry);
2598 }
2599
2600 if (tgid == 0)
2601 goto out;
2602
2603 name.name = buf;
2604 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2605 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2606 if (!leader)
2607 goto out;
2608
2609 name.name = "task";
2610 name.len = strlen(name.name);
2611 dir = d_hash_and_lookup(leader, &name);
2612 if (!dir)
2613 goto out_put_leader;
2614
2615 name.name = buf;
2616 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2617 dentry = d_hash_and_lookup(dir, &name);
2618 if (dentry) {
2619 shrink_dcache_parent(dentry);
2620 d_drop(dentry);
2621 dput(dentry);
2622 }
2623
2624 dput(dir);
2625 out_put_leader:
2626 dput(leader);
2627 out:
2628 return;
2629 }
2630
2631 /**
2632 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2633 * @task: task that should be flushed.
2634 *
2635 * When flushing dentries from proc, one needs to flush them from global
2636 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2637 * in. This call is supposed to do all of this job.
2638 *
2639 * Looks in the dcache for
2640 * /proc/@pid
2641 * /proc/@tgid/task/@pid
2642 * if either directory is present flushes it and all of it'ts children
2643 * from the dcache.
2644 *
2645 * It is safe and reasonable to cache /proc entries for a task until
2646 * that task exits. After that they just clog up the dcache with
2647 * useless entries, possibly causing useful dcache entries to be
2648 * flushed instead. This routine is proved to flush those useless
2649 * dcache entries at process exit time.
2650 *
2651 * NOTE: This routine is just an optimization so it does not guarantee
2652 * that no dcache entries will exist at process exit time it
2653 * just makes it very unlikely that any will persist.
2654 */
2655
2656 void proc_flush_task(struct task_struct *task)
2657 {
2658 int i;
2659 struct pid *pid, *tgid = NULL;
2660 struct upid *upid;
2661
2662 pid = task_pid(task);
2663 if (thread_group_leader(task))
2664 tgid = task_tgid(task);
2665
2666 for (i = 0; i <= pid->level; i++) {
2667 upid = &pid->numbers[i];
2668 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2669 tgid ? tgid->numbers[i].nr : 0);
2670 }
2671
2672 upid = &pid->numbers[pid->level];
2673 if (upid->nr == 1)
2674 pid_ns_release_proc(upid->ns);
2675 }
2676
2677 static struct dentry *proc_pid_instantiate(struct inode *dir,
2678 struct dentry * dentry,
2679 struct task_struct *task, const void *ptr)
2680 {
2681 struct dentry *error = ERR_PTR(-ENOENT);
2682 struct inode *inode;
2683
2684 inode = proc_pid_make_inode(dir->i_sb, task);
2685 if (!inode)
2686 goto out;
2687
2688 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2689 inode->i_op = &proc_tgid_base_inode_operations;
2690 inode->i_fop = &proc_tgid_base_operations;
2691 inode->i_flags|=S_IMMUTABLE;
2692
2693 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
2694 ARRAY_SIZE(tgid_base_stuff));
2695
2696 dentry->d_op = &pid_dentry_operations;
2697
2698 d_add(dentry, inode);
2699 /* Close the race of the process dying before we return the dentry */
2700 if (pid_revalidate(dentry, NULL))
2701 error = NULL;
2702 out:
2703 return error;
2704 }
2705
2706 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2707 {
2708 struct dentry *result = ERR_PTR(-ENOENT);
2709 struct task_struct *task;
2710 unsigned tgid;
2711 struct pid_namespace *ns;
2712
2713 result = proc_base_lookup(dir, dentry);
2714 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
2715 goto out;
2716
2717 tgid = name_to_int(dentry);
2718 if (tgid == ~0U)
2719 goto out;
2720
2721 ns = dentry->d_sb->s_fs_info;
2722 rcu_read_lock();
2723 task = find_task_by_pid_ns(tgid, ns);
2724 if (task)
2725 get_task_struct(task);
2726 rcu_read_unlock();
2727 if (!task)
2728 goto out;
2729
2730 result = proc_pid_instantiate(dir, dentry, task, NULL);
2731 put_task_struct(task);
2732 out:
2733 return result;
2734 }
2735
2736 /*
2737 * Find the first task with tgid >= tgid
2738 *
2739 */
2740 struct tgid_iter {
2741 unsigned int tgid;
2742 struct task_struct *task;
2743 };
2744 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2745 {
2746 struct pid *pid;
2747
2748 if (iter.task)
2749 put_task_struct(iter.task);
2750 rcu_read_lock();
2751 retry:
2752 iter.task = NULL;
2753 pid = find_ge_pid(iter.tgid, ns);
2754 if (pid) {
2755 iter.tgid = pid_nr_ns(pid, ns);
2756 iter.task = pid_task(pid, PIDTYPE_PID);
2757 /* What we to know is if the pid we have find is the
2758 * pid of a thread_group_leader. Testing for task
2759 * being a thread_group_leader is the obvious thing
2760 * todo but there is a window when it fails, due to
2761 * the pid transfer logic in de_thread.
2762 *
2763 * So we perform the straight forward test of seeing
2764 * if the pid we have found is the pid of a thread
2765 * group leader, and don't worry if the task we have
2766 * found doesn't happen to be a thread group leader.
2767 * As we don't care in the case of readdir.
2768 */
2769 if (!iter.task || !has_group_leader_pid(iter.task)) {
2770 iter.tgid += 1;
2771 goto retry;
2772 }
2773 get_task_struct(iter.task);
2774 }
2775 rcu_read_unlock();
2776 return iter;
2777 }
2778
2779 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
2780
2781 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2782 struct tgid_iter iter)
2783 {
2784 char name[PROC_NUMBUF];
2785 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
2786 return proc_fill_cache(filp, dirent, filldir, name, len,
2787 proc_pid_instantiate, iter.task, NULL);
2788 }
2789
2790 /* for the /proc/ directory itself, after non-process stuff has been done */
2791 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2792 {
2793 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2794 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode);
2795 struct tgid_iter iter;
2796 struct pid_namespace *ns;
2797
2798 if (!reaper)
2799 goto out_no_task;
2800
2801 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
2802 const struct pid_entry *p = &proc_base_stuff[nr];
2803 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
2804 goto out;
2805 }
2806
2807 ns = filp->f_dentry->d_sb->s_fs_info;
2808 iter.task = NULL;
2809 iter.tgid = filp->f_pos - TGID_OFFSET;
2810 for (iter = next_tgid(ns, iter);
2811 iter.task;
2812 iter.tgid += 1, iter = next_tgid(ns, iter)) {
2813 filp->f_pos = iter.tgid + TGID_OFFSET;
2814 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
2815 put_task_struct(iter.task);
2816 goto out;
2817 }
2818 }
2819 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
2820 out:
2821 put_task_struct(reaper);
2822 out_no_task:
2823 return 0;
2824 }
2825
2826 /*
2827 * Tasks
2828 */
2829 static const struct pid_entry tid_base_stuff[] = {
2830 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2831 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fd_operations),
2832 REG("environ", S_IRUSR, proc_environ_operations),
2833 INF("auxv", S_IRUSR, proc_pid_auxv),
2834 ONE("status", S_IRUGO, proc_pid_status),
2835 ONE("personality", S_IRUSR, proc_pid_personality),
2836 INF("limits", S_IRUSR, proc_pid_limits),
2837 #ifdef CONFIG_SCHED_DEBUG
2838 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2839 #endif
2840 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2841 INF("syscall", S_IRUSR, proc_pid_syscall),
2842 #endif
2843 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2844 ONE("stat", S_IRUGO, proc_tid_stat),
2845 ONE("statm", S_IRUGO, proc_pid_statm),
2846 REG("maps", S_IRUGO, proc_maps_operations),
2847 #ifdef CONFIG_NUMA
2848 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
2849 #endif
2850 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2851 LNK("cwd", proc_cwd_link),
2852 LNK("root", proc_root_link),
2853 LNK("exe", proc_exe_link),
2854 REG("mounts", S_IRUGO, proc_mounts_operations),
2855 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2856 #ifdef CONFIG_PROC_PAGE_MONITOR
2857 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2858 REG("smaps", S_IRUGO, proc_smaps_operations),
2859 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2860 #endif
2861 #ifdef CONFIG_SECURITY
2862 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2863 #endif
2864 #ifdef CONFIG_KALLSYMS
2865 INF("wchan", S_IRUGO, proc_pid_wchan),
2866 #endif
2867 #ifdef CONFIG_STACKTRACE
2868 ONE("stack", S_IRUSR, proc_pid_stack),
2869 #endif
2870 #ifdef CONFIG_SCHEDSTATS
2871 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2872 #endif
2873 #ifdef CONFIG_LATENCYTOP
2874 REG("latency", S_IRUGO, proc_lstats_operations),
2875 #endif
2876 #ifdef CONFIG_PROC_PID_CPUSET
2877 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2878 #endif
2879 #ifdef CONFIG_CGROUPS
2880 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2881 #endif
2882 INF("oom_score", S_IRUGO, proc_oom_score),
2883 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2884 #ifdef CONFIG_AUDITSYSCALL
2885 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2886 REG("sessionid", S_IRUSR, proc_sessionid_operations),
2887 #endif
2888 #ifdef CONFIG_FAULT_INJECTION
2889 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2890 #endif
2891 #ifdef CONFIG_TASK_IO_ACCOUNTING
2892 INF("io", S_IRUGO, proc_tid_io_accounting),
2893 #endif
2894 };
2895
2896 static int proc_tid_base_readdir(struct file * filp,
2897 void * dirent, filldir_t filldir)
2898 {
2899 return proc_pident_readdir(filp,dirent,filldir,
2900 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
2901 }
2902
2903 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2904 return proc_pident_lookup(dir, dentry,
2905 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
2906 }
2907
2908 static const struct file_operations proc_tid_base_operations = {
2909 .read = generic_read_dir,
2910 .readdir = proc_tid_base_readdir,
2911 };
2912
2913 static const struct inode_operations proc_tid_base_inode_operations = {
2914 .lookup = proc_tid_base_lookup,
2915 .getattr = pid_getattr,
2916 .setattr = proc_setattr,
2917 };
2918
2919 static struct dentry *proc_task_instantiate(struct inode *dir,
2920 struct dentry *dentry, struct task_struct *task, const void *ptr)
2921 {
2922 struct dentry *error = ERR_PTR(-ENOENT);
2923 struct inode *inode;
2924 inode = proc_pid_make_inode(dir->i_sb, task);
2925
2926 if (!inode)
2927 goto out;
2928 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2929 inode->i_op = &proc_tid_base_inode_operations;
2930 inode->i_fop = &proc_tid_base_operations;
2931 inode->i_flags|=S_IMMUTABLE;
2932
2933 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
2934 ARRAY_SIZE(tid_base_stuff));
2935
2936 dentry->d_op = &pid_dentry_operations;
2937
2938 d_add(dentry, inode);
2939 /* Close the race of the process dying before we return the dentry */
2940 if (pid_revalidate(dentry, NULL))
2941 error = NULL;
2942 out:
2943 return error;
2944 }
2945
2946 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2947 {
2948 struct dentry *result = ERR_PTR(-ENOENT);
2949 struct task_struct *task;
2950 struct task_struct *leader = get_proc_task(dir);
2951 unsigned tid;
2952 struct pid_namespace *ns;
2953
2954 if (!leader)
2955 goto out_no_task;
2956
2957 tid = name_to_int(dentry);
2958 if (tid == ~0U)
2959 goto out;
2960
2961 ns = dentry->d_sb->s_fs_info;
2962 rcu_read_lock();
2963 task = find_task_by_pid_ns(tid, ns);
2964 if (task)
2965 get_task_struct(task);
2966 rcu_read_unlock();
2967 if (!task)
2968 goto out;
2969 if (!same_thread_group(leader, task))
2970 goto out_drop_task;
2971
2972 result = proc_task_instantiate(dir, dentry, task, NULL);
2973 out_drop_task:
2974 put_task_struct(task);
2975 out:
2976 put_task_struct(leader);
2977 out_no_task:
2978 return result;
2979 }
2980
2981 /*
2982 * Find the first tid of a thread group to return to user space.
2983 *
2984 * Usually this is just the thread group leader, but if the users
2985 * buffer was too small or there was a seek into the middle of the
2986 * directory we have more work todo.
2987 *
2988 * In the case of a short read we start with find_task_by_pid.
2989 *
2990 * In the case of a seek we start with the leader and walk nr
2991 * threads past it.
2992 */
2993 static struct task_struct *first_tid(struct task_struct *leader,
2994 int tid, int nr, struct pid_namespace *ns)
2995 {
2996 struct task_struct *pos;
2997
2998 rcu_read_lock();
2999 /* Attempt to start with the pid of a thread */
3000 if (tid && (nr > 0)) {
3001 pos = find_task_by_pid_ns(tid, ns);
3002 if (pos && (pos->group_leader == leader))
3003 goto found;
3004 }
3005
3006 /* If nr exceeds the number of threads there is nothing todo */
3007 pos = NULL;
3008 if (nr && nr >= get_nr_threads(leader))
3009 goto out;
3010
3011 /* If we haven't found our starting place yet start
3012 * with the leader and walk nr threads forward.
3013 */
3014 for (pos = leader; nr > 0; --nr) {
3015 pos = next_thread(pos);
3016 if (pos == leader) {
3017 pos = NULL;
3018 goto out;
3019 }
3020 }
3021 found:
3022 get_task_struct(pos);
3023 out:
3024 rcu_read_unlock();
3025 return pos;
3026 }
3027
3028 /*
3029 * Find the next thread in the thread list.
3030 * Return NULL if there is an error or no next thread.
3031 *
3032 * The reference to the input task_struct is released.
3033 */
3034 static struct task_struct *next_tid(struct task_struct *start)
3035 {
3036 struct task_struct *pos = NULL;
3037 rcu_read_lock();
3038 if (pid_alive(start)) {
3039 pos = next_thread(start);
3040 if (thread_group_leader(pos))
3041 pos = NULL;
3042 else
3043 get_task_struct(pos);
3044 }
3045 rcu_read_unlock();
3046 put_task_struct(start);
3047 return pos;
3048 }
3049
3050 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3051 struct task_struct *task, int tid)
3052 {
3053 char name[PROC_NUMBUF];
3054 int len = snprintf(name, sizeof(name), "%d", tid);
3055 return proc_fill_cache(filp, dirent, filldir, name, len,
3056 proc_task_instantiate, task, NULL);
3057 }
3058
3059 /* for the /proc/TGID/task/ directories */
3060 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3061 {
3062 struct dentry *dentry = filp->f_path.dentry;
3063 struct inode *inode = dentry->d_inode;
3064 struct task_struct *leader = NULL;
3065 struct task_struct *task;
3066 int retval = -ENOENT;
3067 ino_t ino;
3068 int tid;
3069 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */
3070 struct pid_namespace *ns;
3071
3072 task = get_proc_task(inode);
3073 if (!task)
3074 goto out_no_task;
3075 rcu_read_lock();
3076 if (pid_alive(task)) {
3077 leader = task->group_leader;
3078 get_task_struct(leader);
3079 }
3080 rcu_read_unlock();
3081 put_task_struct(task);
3082 if (!leader)
3083 goto out_no_task;
3084 retval = 0;
3085
3086 switch (pos) {
3087 case 0:
3088 ino = inode->i_ino;
3089 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0)
3090 goto out;
3091 pos++;
3092 /* fall through */
3093 case 1:
3094 ino = parent_ino(dentry);
3095 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0)
3096 goto out;
3097 pos++;
3098 /* fall through */
3099 }
3100
3101 /* f_version caches the tgid value that the last readdir call couldn't
3102 * return. lseek aka telldir automagically resets f_version to 0.
3103 */
3104 ns = filp->f_dentry->d_sb->s_fs_info;
3105 tid = (int)filp->f_version;
3106 filp->f_version = 0;
3107 for (task = first_tid(leader, tid, pos - 2, ns);
3108 task;
3109 task = next_tid(task), pos++) {
3110 tid = task_pid_nr_ns(task, ns);
3111 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3112 /* returning this tgid failed, save it as the first
3113 * pid for the next readir call */
3114 filp->f_version = (u64)tid;
3115 put_task_struct(task);
3116 break;
3117 }
3118 }
3119 out:
3120 filp->f_pos = pos;
3121 put_task_struct(leader);
3122 out_no_task:
3123 return retval;
3124 }
3125
3126 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3127 {
3128 struct inode *inode = dentry->d_inode;
3129 struct task_struct *p = get_proc_task(inode);
3130 generic_fillattr(inode, stat);
3131
3132 if (p) {
3133 stat->nlink += get_nr_threads(p);
3134 put_task_struct(p);
3135 }
3136
3137 return 0;
3138 }
3139
3140 static const struct inode_operations proc_task_inode_operations = {
3141 .lookup = proc_task_lookup,
3142 .getattr = proc_task_getattr,
3143 .setattr = proc_setattr,
3144 };
3145
3146 static const struct file_operations proc_task_operations = {
3147 .read = generic_read_dir,
3148 .readdir = proc_task_readdir,
3149 };
linux-next