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[PATCH] TIF_RESTORE_SIGMASK support for arch/powerpc
[linux-2.6/mini2440.git] / fs / proc / base.c
blob20feb7568deb4e3456f596ed98318c49e6de2c09
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/config.h>
53 #include <linux/errno.h>
54 #include <linux/time.h>
55 #include <linux/proc_fs.h>
56 #include <linux/stat.h>
57 #include <linux/init.h>
58 #include <linux/capability.h>
59 #include <linux/file.h>
60 #include <linux/string.h>
61 #include <linux/seq_file.h>
62 #include <linux/namei.h>
63 #include <linux/namespace.h>
64 #include <linux/mm.h>
65 #include <linux/smp_lock.h>
66 #include <linux/rcupdate.h>
67 #include <linux/kallsyms.h>
68 #include <linux/mount.h>
69 #include <linux/security.h>
70 #include <linux/ptrace.h>
71 #include <linux/seccomp.h>
72 #include <linux/cpuset.h>
73 #include <linux/audit.h>
74 #include <linux/poll.h>
75 #include "internal.h"
76
77 /*
78 * For hysterical raisins we keep the same inumbers as in the old procfs.
79 * Feel free to change the macro below - just keep the range distinct from
80 * inumbers of the rest of procfs (currently those are in 0x0000--0xffff).
81 * As soon as we'll get a separate superblock we will be able to forget
82 * about magical ranges too.
83 */
84
85 #define fake_ino(pid,ino) (((pid)<<16)|(ino))
86
87 enum pid_directory_inos {
88 PROC_TGID_INO = 2,
89 PROC_TGID_TASK,
90 PROC_TGID_STATUS,
91 PROC_TGID_MEM,
92 #ifdef CONFIG_SECCOMP
93 PROC_TGID_SECCOMP,
94 #endif
95 PROC_TGID_CWD,
96 PROC_TGID_ROOT,
97 PROC_TGID_EXE,
98 PROC_TGID_FD,
99 PROC_TGID_ENVIRON,
100 PROC_TGID_AUXV,
101 PROC_TGID_CMDLINE,
102 PROC_TGID_STAT,
103 PROC_TGID_STATM,
104 PROC_TGID_MAPS,
105 PROC_TGID_NUMA_MAPS,
106 PROC_TGID_MOUNTS,
107 PROC_TGID_WCHAN,
108 #ifdef CONFIG_MMU
109 PROC_TGID_SMAPS,
110 #endif
111 #ifdef CONFIG_SCHEDSTATS
112 PROC_TGID_SCHEDSTAT,
113 #endif
114 #ifdef CONFIG_CPUSETS
115 PROC_TGID_CPUSET,
116 #endif
117 #ifdef CONFIG_SECURITY
118 PROC_TGID_ATTR,
119 PROC_TGID_ATTR_CURRENT,
120 PROC_TGID_ATTR_PREV,
121 PROC_TGID_ATTR_EXEC,
122 PROC_TGID_ATTR_FSCREATE,
123 #endif
124 #ifdef CONFIG_AUDITSYSCALL
125 PROC_TGID_LOGINUID,
126 #endif
127 PROC_TGID_OOM_SCORE,
128 PROC_TGID_OOM_ADJUST,
129 PROC_TID_INO,
130 PROC_TID_STATUS,
131 PROC_TID_MEM,
132 #ifdef CONFIG_SECCOMP
133 PROC_TID_SECCOMP,
134 #endif
135 PROC_TID_CWD,
136 PROC_TID_ROOT,
137 PROC_TID_EXE,
138 PROC_TID_FD,
139 PROC_TID_ENVIRON,
140 PROC_TID_AUXV,
141 PROC_TID_CMDLINE,
142 PROC_TID_STAT,
143 PROC_TID_STATM,
144 PROC_TID_MAPS,
145 PROC_TID_NUMA_MAPS,
146 PROC_TID_MOUNTS,
147 PROC_TID_WCHAN,
148 #ifdef CONFIG_MMU
149 PROC_TID_SMAPS,
150 #endif
151 #ifdef CONFIG_SCHEDSTATS
152 PROC_TID_SCHEDSTAT,
153 #endif
154 #ifdef CONFIG_CPUSETS
155 PROC_TID_CPUSET,
156 #endif
157 #ifdef CONFIG_SECURITY
158 PROC_TID_ATTR,
159 PROC_TID_ATTR_CURRENT,
160 PROC_TID_ATTR_PREV,
161 PROC_TID_ATTR_EXEC,
162 PROC_TID_ATTR_FSCREATE,
163 #endif
164 #ifdef CONFIG_AUDITSYSCALL
165 PROC_TID_LOGINUID,
166 #endif
167 PROC_TID_OOM_SCORE,
168 PROC_TID_OOM_ADJUST,
169
170 /* Add new entries before this */
171 PROC_TID_FD_DIR = 0x8000, /* 0x8000-0xffff */
172 };
173
174 struct pid_entry {
175 int type;
176 int len;
177 char *name;
178 mode_t mode;
179 };
180
181 #define E(type,name,mode) {(type),sizeof(name)-1,(name),(mode)}
182
183 static struct pid_entry tgid_base_stuff[] = {
184 E(PROC_TGID_TASK, "task", S_IFDIR|S_IRUGO|S_IXUGO),
185 E(PROC_TGID_FD, "fd", S_IFDIR|S_IRUSR|S_IXUSR),
186 E(PROC_TGID_ENVIRON, "environ", S_IFREG|S_IRUSR),
187 E(PROC_TGID_AUXV, "auxv", S_IFREG|S_IRUSR),
188 E(PROC_TGID_STATUS, "status", S_IFREG|S_IRUGO),
189 E(PROC_TGID_CMDLINE, "cmdline", S_IFREG|S_IRUGO),
190 E(PROC_TGID_STAT, "stat", S_IFREG|S_IRUGO),
191 E(PROC_TGID_STATM, "statm", S_IFREG|S_IRUGO),
192 E(PROC_TGID_MAPS, "maps", S_IFREG|S_IRUGO),
193 #ifdef CONFIG_NUMA
194 E(PROC_TGID_NUMA_MAPS, "numa_maps", S_IFREG|S_IRUGO),
195 #endif
196 E(PROC_TGID_MEM, "mem", S_IFREG|S_IRUSR|S_IWUSR),
197 #ifdef CONFIG_SECCOMP
198 E(PROC_TGID_SECCOMP, "seccomp", S_IFREG|S_IRUSR|S_IWUSR),
199 #endif
200 E(PROC_TGID_CWD, "cwd", S_IFLNK|S_IRWXUGO),
201 E(PROC_TGID_ROOT, "root", S_IFLNK|S_IRWXUGO),
202 E(PROC_TGID_EXE, "exe", S_IFLNK|S_IRWXUGO),
203 E(PROC_TGID_MOUNTS, "mounts", S_IFREG|S_IRUGO),
204 #ifdef CONFIG_MMU
205 E(PROC_TGID_SMAPS, "smaps", S_IFREG|S_IRUGO),
206 #endif
207 #ifdef CONFIG_SECURITY
208 E(PROC_TGID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO),
209 #endif
210 #ifdef CONFIG_KALLSYMS
211 E(PROC_TGID_WCHAN, "wchan", S_IFREG|S_IRUGO),
212 #endif
213 #ifdef CONFIG_SCHEDSTATS
214 E(PROC_TGID_SCHEDSTAT, "schedstat", S_IFREG|S_IRUGO),
215 #endif
216 #ifdef CONFIG_CPUSETS
217 E(PROC_TGID_CPUSET, "cpuset", S_IFREG|S_IRUGO),
218 #endif
219 E(PROC_TGID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO),
220 E(PROC_TGID_OOM_ADJUST,"oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
221 #ifdef CONFIG_AUDITSYSCALL
222 E(PROC_TGID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO),
223 #endif
224 {0,0,NULL,0}
225 };
226 static struct pid_entry tid_base_stuff[] = {
227 E(PROC_TID_FD, "fd", S_IFDIR|S_IRUSR|S_IXUSR),
228 E(PROC_TID_ENVIRON, "environ", S_IFREG|S_IRUSR),
229 E(PROC_TID_AUXV, "auxv", S_IFREG|S_IRUSR),
230 E(PROC_TID_STATUS, "status", S_IFREG|S_IRUGO),
231 E(PROC_TID_CMDLINE, "cmdline", S_IFREG|S_IRUGO),
232 E(PROC_TID_STAT, "stat", S_IFREG|S_IRUGO),
233 E(PROC_TID_STATM, "statm", S_IFREG|S_IRUGO),
234 E(PROC_TID_MAPS, "maps", S_IFREG|S_IRUGO),
235 #ifdef CONFIG_NUMA
236 E(PROC_TID_NUMA_MAPS, "numa_maps", S_IFREG|S_IRUGO),
237 #endif
238 E(PROC_TID_MEM, "mem", S_IFREG|S_IRUSR|S_IWUSR),
239 #ifdef CONFIG_SECCOMP
240 E(PROC_TID_SECCOMP, "seccomp", S_IFREG|S_IRUSR|S_IWUSR),
241 #endif
242 E(PROC_TID_CWD, "cwd", S_IFLNK|S_IRWXUGO),
243 E(PROC_TID_ROOT, "root", S_IFLNK|S_IRWXUGO),
244 E(PROC_TID_EXE, "exe", S_IFLNK|S_IRWXUGO),
245 E(PROC_TID_MOUNTS, "mounts", S_IFREG|S_IRUGO),
246 #ifdef CONFIG_MMU
247 E(PROC_TID_SMAPS, "smaps", S_IFREG|S_IRUGO),
248 #endif
249 #ifdef CONFIG_SECURITY
250 E(PROC_TID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO),
251 #endif
252 #ifdef CONFIG_KALLSYMS
253 E(PROC_TID_WCHAN, "wchan", S_IFREG|S_IRUGO),
254 #endif
255 #ifdef CONFIG_SCHEDSTATS
256 E(PROC_TID_SCHEDSTAT, "schedstat",S_IFREG|S_IRUGO),
257 #endif
258 #ifdef CONFIG_CPUSETS
259 E(PROC_TID_CPUSET, "cpuset", S_IFREG|S_IRUGO),
260 #endif
261 E(PROC_TID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO),
262 E(PROC_TID_OOM_ADJUST, "oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
263 #ifdef CONFIG_AUDITSYSCALL
264 E(PROC_TID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO),
265 #endif
266 {0,0,NULL,0}
267 };
268
269 #ifdef CONFIG_SECURITY
270 static struct pid_entry tgid_attr_stuff[] = {
271 E(PROC_TGID_ATTR_CURRENT, "current", S_IFREG|S_IRUGO|S_IWUGO),
272 E(PROC_TGID_ATTR_PREV, "prev", S_IFREG|S_IRUGO),
273 E(PROC_TGID_ATTR_EXEC, "exec", S_IFREG|S_IRUGO|S_IWUGO),
274 E(PROC_TGID_ATTR_FSCREATE, "fscreate", S_IFREG|S_IRUGO|S_IWUGO),
275 {0,0,NULL,0}
276 };
277 static struct pid_entry tid_attr_stuff[] = {
278 E(PROC_TID_ATTR_CURRENT, "current", S_IFREG|S_IRUGO|S_IWUGO),
279 E(PROC_TID_ATTR_PREV, "prev", S_IFREG|S_IRUGO),
280 E(PROC_TID_ATTR_EXEC, "exec", S_IFREG|S_IRUGO|S_IWUGO),
281 E(PROC_TID_ATTR_FSCREATE, "fscreate", S_IFREG|S_IRUGO|S_IWUGO),
282 {0,0,NULL,0}
283 };
284 #endif
285
286 #undef E
287
288 static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
289 {
290 struct task_struct *task = proc_task(inode);
291 struct files_struct *files;
292 struct file *file;
293 int fd = proc_type(inode) - PROC_TID_FD_DIR;
294
295 files = get_files_struct(task);
296 if (files) {
297 rcu_read_lock();
298 file = fcheck_files(files, fd);
299 if (file) {
300 *mnt = mntget(file->f_vfsmnt);
301 *dentry = dget(file->f_dentry);
302 rcu_read_unlock();
303 put_files_struct(files);
304 return 0;
305 }
306 rcu_read_unlock();
307 put_files_struct(files);
308 }
309 return -ENOENT;
310 }
311
312 static struct fs_struct *get_fs_struct(struct task_struct *task)
313 {
314 struct fs_struct *fs;
315 task_lock(task);
316 fs = task->fs;
317 if(fs)
318 atomic_inc(&fs->count);
319 task_unlock(task);
320 return fs;
321 }
322
323 static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
324 {
325 struct fs_struct *fs = get_fs_struct(proc_task(inode));
326 int result = -ENOENT;
327 if (fs) {
328 read_lock(&fs->lock);
329 *mnt = mntget(fs->pwdmnt);
330 *dentry = dget(fs->pwd);
331 read_unlock(&fs->lock);
332 result = 0;
333 put_fs_struct(fs);
334 }
335 return result;
336 }
337
338 static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
339 {
340 struct fs_struct *fs = get_fs_struct(proc_task(inode));
341 int result = -ENOENT;
342 if (fs) {
343 read_lock(&fs->lock);
344 *mnt = mntget(fs->rootmnt);
345 *dentry = dget(fs->root);
346 read_unlock(&fs->lock);
347 result = 0;
348 put_fs_struct(fs);
349 }
350 return result;
351 }
352
353
354 /* Same as proc_root_link, but this addionally tries to get fs from other
355 * threads in the group */
356 static int proc_task_root_link(struct inode *inode, struct dentry **dentry,
357 struct vfsmount **mnt)
358 {
359 struct fs_struct *fs;
360 int result = -ENOENT;
361 struct task_struct *leader = proc_task(inode);
362
363 task_lock(leader);
364 fs = leader->fs;
365 if (fs) {
366 atomic_inc(&fs->count);
367 task_unlock(leader);
368 } else {
369 /* Try to get fs from other threads */
370 task_unlock(leader);
371 read_lock(&tasklist_lock);
372 if (pid_alive(leader)) {
373 struct task_struct *task = leader;
374
375 while ((task = next_thread(task)) != leader) {
376 task_lock(task);
377 fs = task->fs;
378 if (fs) {
379 atomic_inc(&fs->count);
380 task_unlock(task);
381 break;
382 }
383 task_unlock(task);
384 }
385 }
386 read_unlock(&tasklist_lock);
387 }
388
389 if (fs) {
390 read_lock(&fs->lock);
391 *mnt = mntget(fs->rootmnt);
392 *dentry = dget(fs->root);
393 read_unlock(&fs->lock);
394 result = 0;
395 put_fs_struct(fs);
396 }
397 return result;
398 }
399
400
401 #define MAY_PTRACE(task) \
402 (task == current || \
403 (task->parent == current && \
404 (task->ptrace & PT_PTRACED) && \
405 (task->state == TASK_STOPPED || task->state == TASK_TRACED) && \
406 security_ptrace(current,task) == 0))
407
408 static int proc_pid_environ(struct task_struct *task, char * buffer)
409 {
410 int res = 0;
411 struct mm_struct *mm = get_task_mm(task);
412 if (mm) {
413 unsigned int len = mm->env_end - mm->env_start;
414 if (len > PAGE_SIZE)
415 len = PAGE_SIZE;
416 res = access_process_vm(task, mm->env_start, buffer, len, 0);
417 if (!ptrace_may_attach(task))
418 res = -ESRCH;
419 mmput(mm);
420 }
421 return res;
422 }
423
424 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
425 {
426 int res = 0;
427 unsigned int len;
428 struct mm_struct *mm = get_task_mm(task);
429 if (!mm)
430 goto out;
431 if (!mm->arg_end)
432 goto out_mm; /* Shh! No looking before we're done */
433
434 len = mm->arg_end - mm->arg_start;
435
436 if (len > PAGE_SIZE)
437 len = PAGE_SIZE;
438
439 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
440
441 // If the nul at the end of args has been overwritten, then
442 // assume application is using setproctitle(3).
443 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
444 len = strnlen(buffer, res);
445 if (len < res) {
446 res = len;
447 } else {
448 len = mm->env_end - mm->env_start;
449 if (len > PAGE_SIZE - res)
450 len = PAGE_SIZE - res;
451 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
452 res = strnlen(buffer, res);
453 }
454 }
455 out_mm:
456 mmput(mm);
457 out:
458 return res;
459 }
460
461 static int proc_pid_auxv(struct task_struct *task, char *buffer)
462 {
463 int res = 0;
464 struct mm_struct *mm = get_task_mm(task);
465 if (mm) {
466 unsigned int nwords = 0;
467 do
468 nwords += 2;
469 while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
470 res = nwords * sizeof(mm->saved_auxv[0]);
471 if (res > PAGE_SIZE)
472 res = PAGE_SIZE;
473 memcpy(buffer, mm->saved_auxv, res);
474 mmput(mm);
475 }
476 return res;
477 }
478
479
480 #ifdef CONFIG_KALLSYMS
481 /*
482 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
483 * Returns the resolved symbol. If that fails, simply return the address.
484 */
485 static int proc_pid_wchan(struct task_struct *task, char *buffer)
486 {
487 char *modname;
488 const char *sym_name;
489 unsigned long wchan, size, offset;
490 char namebuf[KSYM_NAME_LEN+1];
491
492 wchan = get_wchan(task);
493
494 sym_name = kallsyms_lookup(wchan, &size, &offset, &modname, namebuf);
495 if (sym_name)
496 return sprintf(buffer, "%s", sym_name);
497 return sprintf(buffer, "%lu", wchan);
498 }
499 #endif /* CONFIG_KALLSYMS */
500
501 #ifdef CONFIG_SCHEDSTATS
502 /*
503 * Provides /proc/PID/schedstat
504 */
505 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
506 {
507 return sprintf(buffer, "%lu %lu %lu\n",
508 task->sched_info.cpu_time,
509 task->sched_info.run_delay,
510 task->sched_info.pcnt);
511 }
512 #endif
513
514 /* The badness from the OOM killer */
515 unsigned long badness(struct task_struct *p, unsigned long uptime);
516 static int proc_oom_score(struct task_struct *task, char *buffer)
517 {
518 unsigned long points;
519 struct timespec uptime;
520
521 do_posix_clock_monotonic_gettime(&uptime);
522 points = badness(task, uptime.tv_sec);
523 return sprintf(buffer, "%lu\n", points);
524 }
525
526 /************************************************************************/
527 /* Here the fs part begins */
528 /************************************************************************/
529
530 /* permission checks */
531
532 /* If the process being read is separated by chroot from the reading process,
533 * don't let the reader access the threads.
534 */
535 static int proc_check_chroot(struct dentry *root, struct vfsmount *vfsmnt)
536 {
537 struct dentry *de, *base;
538 struct vfsmount *our_vfsmnt, *mnt;
539 int res = 0;
540 read_lock(&current->fs->lock);
541 our_vfsmnt = mntget(current->fs->rootmnt);
542 base = dget(current->fs->root);
543 read_unlock(&current->fs->lock);
544
545 spin_lock(&vfsmount_lock);
546 de = root;
547 mnt = vfsmnt;
548
549 while (vfsmnt != our_vfsmnt) {
550 if (vfsmnt == vfsmnt->mnt_parent)
551 goto out;
552 de = vfsmnt->mnt_mountpoint;
553 vfsmnt = vfsmnt->mnt_parent;
554 }
555
556 if (!is_subdir(de, base))
557 goto out;
558 spin_unlock(&vfsmount_lock);
559
560 exit:
561 dput(base);
562 mntput(our_vfsmnt);
563 dput(root);
564 mntput(mnt);
565 return res;
566 out:
567 spin_unlock(&vfsmount_lock);
568 res = -EACCES;
569 goto exit;
570 }
571
572 static int proc_check_root(struct inode *inode)
573 {
574 struct dentry *root;
575 struct vfsmount *vfsmnt;
576
577 if (proc_root_link(inode, &root, &vfsmnt)) /* Ewww... */
578 return -ENOENT;
579 return proc_check_chroot(root, vfsmnt);
580 }
581
582 static int proc_permission(struct inode *inode, int mask, struct nameidata *nd)
583 {
584 if (generic_permission(inode, mask, NULL) != 0)
585 return -EACCES;
586 return proc_check_root(inode);
587 }
588
589 static int proc_task_permission(struct inode *inode, int mask, struct nameidata *nd)
590 {
591 struct dentry *root;
592 struct vfsmount *vfsmnt;
593
594 if (generic_permission(inode, mask, NULL) != 0)
595 return -EACCES;
596
597 if (proc_task_root_link(inode, &root, &vfsmnt))
598 return -ENOENT;
599
600 return proc_check_chroot(root, vfsmnt);
601 }
602
603 extern struct seq_operations proc_pid_maps_op;
604 static int maps_open(struct inode *inode, struct file *file)
605 {
606 struct task_struct *task = proc_task(inode);
607 int ret = seq_open(file, &proc_pid_maps_op);
608 if (!ret) {
609 struct seq_file *m = file->private_data;
610 m->private = task;
611 }
612 return ret;
613 }
614
615 static struct file_operations proc_maps_operations = {
616 .open = maps_open,
617 .read = seq_read,
618 .llseek = seq_lseek,
619 .release = seq_release,
620 };
621
622 #ifdef CONFIG_NUMA
623 extern struct seq_operations proc_pid_numa_maps_op;
624 static int numa_maps_open(struct inode *inode, struct file *file)
625 {
626 struct task_struct *task = proc_task(inode);
627 int ret = seq_open(file, &proc_pid_numa_maps_op);
628 if (!ret) {
629 struct seq_file *m = file->private_data;
630 m->private = task;
631 }
632 return ret;
633 }
634
635 static struct file_operations proc_numa_maps_operations = {
636 .open = numa_maps_open,
637 .read = seq_read,
638 .llseek = seq_lseek,
639 .release = seq_release,
640 };
641 #endif
642
643 #ifdef CONFIG_MMU
644 extern struct seq_operations proc_pid_smaps_op;
645 static int smaps_open(struct inode *inode, struct file *file)
646 {
647 struct task_struct *task = proc_task(inode);
648 int ret = seq_open(file, &proc_pid_smaps_op);
649 if (!ret) {
650 struct seq_file *m = file->private_data;
651 m->private = task;
652 }
653 return ret;
654 }
655
656 static struct file_operations proc_smaps_operations = {
657 .open = smaps_open,
658 .read = seq_read,
659 .llseek = seq_lseek,
660 .release = seq_release,
661 };
662 #endif
663
664 extern struct seq_operations mounts_op;
665 struct proc_mounts {
666 struct seq_file m;
667 int event;
668 };
669
670 static int mounts_open(struct inode *inode, struct file *file)
671 {
672 struct task_struct *task = proc_task(inode);
673 struct namespace *namespace;
674 struct proc_mounts *p;
675 int ret = -EINVAL;
676
677 task_lock(task);
678 namespace = task->namespace;
679 if (namespace)
680 get_namespace(namespace);
681 task_unlock(task);
682
683 if (namespace) {
684 ret = -ENOMEM;
685 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
686 if (p) {
687 file->private_data = &p->m;
688 ret = seq_open(file, &mounts_op);
689 if (!ret) {
690 p->m.private = namespace;
691 p->event = namespace->event;
692 return 0;
693 }
694 kfree(p);
695 }
696 put_namespace(namespace);
697 }
698 return ret;
699 }
700
701 static int mounts_release(struct inode *inode, struct file *file)
702 {
703 struct seq_file *m = file->private_data;
704 struct namespace *namespace = m->private;
705 put_namespace(namespace);
706 return seq_release(inode, file);
707 }
708
709 static unsigned mounts_poll(struct file *file, poll_table *wait)
710 {
711 struct proc_mounts *p = file->private_data;
712 struct namespace *ns = p->m.private;
713 unsigned res = 0;
714
715 poll_wait(file, &ns->poll, wait);
716
717 spin_lock(&vfsmount_lock);
718 if (p->event != ns->event) {
719 p->event = ns->event;
720 res = POLLERR;
721 }
722 spin_unlock(&vfsmount_lock);
723
724 return res;
725 }
726
727 static struct file_operations proc_mounts_operations = {
728 .open = mounts_open,
729 .read = seq_read,
730 .llseek = seq_lseek,
731 .release = mounts_release,
732 .poll = mounts_poll,
733 };
734
735 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
736
737 static ssize_t proc_info_read(struct file * file, char __user * buf,
738 size_t count, loff_t *ppos)
739 {
740 struct inode * inode = file->f_dentry->d_inode;
741 unsigned long page;
742 ssize_t length;
743 struct task_struct *task = proc_task(inode);
744
745 if (count > PROC_BLOCK_SIZE)
746 count = PROC_BLOCK_SIZE;
747 if (!(page = __get_free_page(GFP_KERNEL)))
748 return -ENOMEM;
749
750 length = PROC_I(inode)->op.proc_read(task, (char*)page);
751
752 if (length >= 0)
753 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
754 free_page(page);
755 return length;
756 }
757
758 static struct file_operations proc_info_file_operations = {
759 .read = proc_info_read,
760 };
761
762 static int mem_open(struct inode* inode, struct file* file)
763 {
764 file->private_data = (void*)((long)current->self_exec_id);
765 return 0;
766 }
767
768 static ssize_t mem_read(struct file * file, char __user * buf,
769 size_t count, loff_t *ppos)
770 {
771 struct task_struct *task = proc_task(file->f_dentry->d_inode);
772 char *page;
773 unsigned long src = *ppos;
774 int ret = -ESRCH;
775 struct mm_struct *mm;
776
777 if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
778 goto out;
779
780 ret = -ENOMEM;
781 page = (char *)__get_free_page(GFP_USER);
782 if (!page)
783 goto out;
784
785 ret = 0;
786
787 mm = get_task_mm(task);
788 if (!mm)
789 goto out_free;
790
791 ret = -EIO;
792
793 if (file->private_data != (void*)((long)current->self_exec_id))
794 goto out_put;
795
796 ret = 0;
797
798 while (count > 0) {
799 int this_len, retval;
800
801 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
802 retval = access_process_vm(task, src, page, this_len, 0);
803 if (!retval || !MAY_PTRACE(task) || !ptrace_may_attach(task)) {
804 if (!ret)
805 ret = -EIO;
806 break;
807 }
808
809 if (copy_to_user(buf, page, retval)) {
810 ret = -EFAULT;
811 break;
812 }
813
814 ret += retval;
815 src += retval;
816 buf += retval;
817 count -= retval;
818 }
819 *ppos = src;
820
821 out_put:
822 mmput(mm);
823 out_free:
824 free_page((unsigned long) page);
825 out:
826 return ret;
827 }
828
829 #define mem_write NULL
830
831 #ifndef mem_write
832 /* This is a security hazard */
833 static ssize_t mem_write(struct file * file, const char * buf,
834 size_t count, loff_t *ppos)
835 {
836 int copied = 0;
837 char *page;
838 struct task_struct *task = proc_task(file->f_dentry->d_inode);
839 unsigned long dst = *ppos;
840
841 if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
842 return -ESRCH;
843
844 page = (char *)__get_free_page(GFP_USER);
845 if (!page)
846 return -ENOMEM;
847
848 while (count > 0) {
849 int this_len, retval;
850
851 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
852 if (copy_from_user(page, buf, this_len)) {
853 copied = -EFAULT;
854 break;
855 }
856 retval = access_process_vm(task, dst, page, this_len, 1);
857 if (!retval) {
858 if (!copied)
859 copied = -EIO;
860 break;
861 }
862 copied += retval;
863 buf += retval;
864 dst += retval;
865 count -= retval;
866 }
867 *ppos = dst;
868 free_page((unsigned long) page);
869 return copied;
870 }
871 #endif
872
873 static loff_t mem_lseek(struct file * file, loff_t offset, int orig)
874 {
875 switch (orig) {
876 case 0:
877 file->f_pos = offset;
878 break;
879 case 1:
880 file->f_pos += offset;
881 break;
882 default:
883 return -EINVAL;
884 }
885 force_successful_syscall_return();
886 return file->f_pos;
887 }
888
889 static struct file_operations proc_mem_operations = {
890 .llseek = mem_lseek,
891 .read = mem_read,
892 .write = mem_write,
893 .open = mem_open,
894 };
895
896 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
897 size_t count, loff_t *ppos)
898 {
899 struct task_struct *task = proc_task(file->f_dentry->d_inode);
900 char buffer[8];
901 size_t len;
902 int oom_adjust = task->oomkilladj;
903 loff_t __ppos = *ppos;
904
905 len = sprintf(buffer, "%i\n", oom_adjust);
906 if (__ppos >= len)
907 return 0;
908 if (count > len-__ppos)
909 count = len-__ppos;
910 if (copy_to_user(buf, buffer + __ppos, count))
911 return -EFAULT;
912 *ppos = __ppos + count;
913 return count;
914 }
915
916 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
917 size_t count, loff_t *ppos)
918 {
919 struct task_struct *task = proc_task(file->f_dentry->d_inode);
920 char buffer[8], *end;
921 int oom_adjust;
922
923 if (!capable(CAP_SYS_RESOURCE))
924 return -EPERM;
925 memset(buffer, 0, 8);
926 if (count > 6)
927 count = 6;
928 if (copy_from_user(buffer, buf, count))
929 return -EFAULT;
930 oom_adjust = simple_strtol(buffer, &end, 0);
931 if ((oom_adjust < -16 || oom_adjust > 15) && oom_adjust != OOM_DISABLE)
932 return -EINVAL;
933 if (*end == '\n')
934 end++;
935 task->oomkilladj = oom_adjust;
936 if (end - buffer == 0)
937 return -EIO;
938 return end - buffer;
939 }
940
941 static struct file_operations proc_oom_adjust_operations = {
942 .read = oom_adjust_read,
943 .write = oom_adjust_write,
944 };
945
946 static struct inode_operations proc_mem_inode_operations = {
947 .permission = proc_permission,
948 };
949
950 #ifdef CONFIG_AUDITSYSCALL
951 #define TMPBUFLEN 21
952 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
953 size_t count, loff_t *ppos)
954 {
955 struct inode * inode = file->f_dentry->d_inode;
956 struct task_struct *task = proc_task(inode);
957 ssize_t length;
958 char tmpbuf[TMPBUFLEN];
959
960 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
961 audit_get_loginuid(task->audit_context));
962 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
963 }
964
965 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
966 size_t count, loff_t *ppos)
967 {
968 struct inode * inode = file->f_dentry->d_inode;
969 char *page, *tmp;
970 ssize_t length;
971 struct task_struct *task = proc_task(inode);
972 uid_t loginuid;
973
974 if (!capable(CAP_AUDIT_CONTROL))
975 return -EPERM;
976
977 if (current != task)
978 return -EPERM;
979
980 if (count > PAGE_SIZE)
981 count = PAGE_SIZE;
982
983 if (*ppos != 0) {
984 /* No partial writes. */
985 return -EINVAL;
986 }
987 page = (char*)__get_free_page(GFP_USER);
988 if (!page)
989 return -ENOMEM;
990 length = -EFAULT;
991 if (copy_from_user(page, buf, count))
992 goto out_free_page;
993
994 loginuid = simple_strtoul(page, &tmp, 10);
995 if (tmp == page) {
996 length = -EINVAL;
997 goto out_free_page;
998
999 }
1000 length = audit_set_loginuid(task, loginuid);
1001 if (likely(length == 0))
1002 length = count;
1003
1004 out_free_page:
1005 free_page((unsigned long) page);
1006 return length;
1007 }
1008
1009 static struct file_operations proc_loginuid_operations = {
1010 .read = proc_loginuid_read,
1011 .write = proc_loginuid_write,
1012 };
1013 #endif
1014
1015 #ifdef CONFIG_SECCOMP
1016 static ssize_t seccomp_read(struct file *file, char __user *buf,
1017 size_t count, loff_t *ppos)
1018 {
1019 struct task_struct *tsk = proc_task(file->f_dentry->d_inode);
1020 char __buf[20];
1021 loff_t __ppos = *ppos;
1022 size_t len;
1023
1024 /* no need to print the trailing zero, so use only len */
1025 len = sprintf(__buf, "%u\n", tsk->seccomp.mode);
1026 if (__ppos >= len)
1027 return 0;
1028 if (count > len - __ppos)
1029 count = len - __ppos;
1030 if (copy_to_user(buf, __buf + __ppos, count))
1031 return -EFAULT;
1032 *ppos = __ppos + count;
1033 return count;
1034 }
1035
1036 static ssize_t seccomp_write(struct file *file, const char __user *buf,
1037 size_t count, loff_t *ppos)
1038 {
1039 struct task_struct *tsk = proc_task(file->f_dentry->d_inode);
1040 char __buf[20], *end;
1041 unsigned int seccomp_mode;
1042
1043 /* can set it only once to be even more secure */
1044 if (unlikely(tsk->seccomp.mode))
1045 return -EPERM;
1046
1047 memset(__buf, 0, sizeof(__buf));
1048 count = min(count, sizeof(__buf) - 1);
1049 if (copy_from_user(__buf, buf, count))
1050 return -EFAULT;
1051 seccomp_mode = simple_strtoul(__buf, &end, 0);
1052 if (*end == '\n')
1053 end++;
1054 if (seccomp_mode && seccomp_mode <= NR_SECCOMP_MODES) {
1055 tsk->seccomp.mode = seccomp_mode;
1056 set_tsk_thread_flag(tsk, TIF_SECCOMP);
1057 } else
1058 return -EINVAL;
1059 if (unlikely(!(end - __buf)))
1060 return -EIO;
1061 return end - __buf;
1062 }
1063
1064 static struct file_operations proc_seccomp_operations = {
1065 .read = seccomp_read,
1066 .write = seccomp_write,
1067 };
1068 #endif /* CONFIG_SECCOMP */
1069
1070 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1071 {
1072 struct inode *inode = dentry->d_inode;
1073 int error = -EACCES;
1074
1075 /* We don't need a base pointer in the /proc filesystem */
1076 path_release(nd);
1077
1078 if (current->fsuid != inode->i_uid && !capable(CAP_DAC_OVERRIDE))
1079 goto out;
1080 error = proc_check_root(inode);
1081 if (error)
1082 goto out;
1083
1084 error = PROC_I(inode)->op.proc_get_link(inode, &nd->dentry, &nd->mnt);
1085 nd->last_type = LAST_BIND;
1086 out:
1087 return ERR_PTR(error);
1088 }
1089
1090 static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt,
1091 char __user *buffer, int buflen)
1092 {
1093 struct inode * inode;
1094 char *tmp = (char*)__get_free_page(GFP_KERNEL), *path;
1095 int len;
1096
1097 if (!tmp)
1098 return -ENOMEM;
1099
1100 inode = dentry->d_inode;
1101 path = d_path(dentry, mnt, tmp, PAGE_SIZE);
1102 len = PTR_ERR(path);
1103 if (IS_ERR(path))
1104 goto out;
1105 len = tmp + PAGE_SIZE - 1 - path;
1106
1107 if (len > buflen)
1108 len = buflen;
1109 if (copy_to_user(buffer, path, len))
1110 len = -EFAULT;
1111 out:
1112 free_page((unsigned long)tmp);
1113 return len;
1114 }
1115
1116 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1117 {
1118 int error = -EACCES;
1119 struct inode *inode = dentry->d_inode;
1120 struct dentry *de;
1121 struct vfsmount *mnt = NULL;
1122
1123 lock_kernel();
1124
1125 if (current->fsuid != inode->i_uid && !capable(CAP_DAC_OVERRIDE))
1126 goto out;
1127 error = proc_check_root(inode);
1128 if (error)
1129 goto out;
1130
1131 error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt);
1132 if (error)
1133 goto out;
1134
1135 error = do_proc_readlink(de, mnt, buffer, buflen);
1136 dput(de);
1137 mntput(mnt);
1138 out:
1139 unlock_kernel();
1140 return error;
1141 }
1142
1143 static struct inode_operations proc_pid_link_inode_operations = {
1144 .readlink = proc_pid_readlink,
1145 .follow_link = proc_pid_follow_link
1146 };
1147
1148 #define NUMBUF 10
1149
1150 static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
1151 {
1152 struct inode *inode = filp->f_dentry->d_inode;
1153 struct task_struct *p = proc_task(inode);
1154 unsigned int fd, tid, ino;
1155 int retval;
1156 char buf[NUMBUF];
1157 struct files_struct * files;
1158 struct fdtable *fdt;
1159
1160 retval = -ENOENT;
1161 if (!pid_alive(p))
1162 goto out;
1163 retval = 0;
1164 tid = p->pid;
1165
1166 fd = filp->f_pos;
1167 switch (fd) {
1168 case 0:
1169 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1170 goto out;
1171 filp->f_pos++;
1172 case 1:
1173 ino = fake_ino(tid, PROC_TID_INO);
1174 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1175 goto out;
1176 filp->f_pos++;
1177 default:
1178 files = get_files_struct(p);
1179 if (!files)
1180 goto out;
1181 rcu_read_lock();
1182 fdt = files_fdtable(files);
1183 for (fd = filp->f_pos-2;
1184 fd < fdt->max_fds;
1185 fd++, filp->f_pos++) {
1186 unsigned int i,j;
1187
1188 if (!fcheck_files(files, fd))
1189 continue;
1190 rcu_read_unlock();
1191
1192 j = NUMBUF;
1193 i = fd;
1194 do {
1195 j--;
1196 buf[j] = '0' + (i % 10);
1197 i /= 10;
1198 } while (i);
1199
1200 ino = fake_ino(tid, PROC_TID_FD_DIR + fd);
1201 if (filldir(dirent, buf+j, NUMBUF-j, fd+2, ino, DT_LNK) < 0) {
1202 rcu_read_lock();
1203 break;
1204 }
1205 rcu_read_lock();
1206 }
1207 rcu_read_unlock();
1208 put_files_struct(files);
1209 }
1210 out:
1211 return retval;
1212 }
1213
1214 static int proc_pident_readdir(struct file *filp,
1215 void *dirent, filldir_t filldir,
1216 struct pid_entry *ents, unsigned int nents)
1217 {
1218 int i;
1219 int pid;
1220 struct dentry *dentry = filp->f_dentry;
1221 struct inode *inode = dentry->d_inode;
1222 struct pid_entry *p;
1223 ino_t ino;
1224 int ret;
1225
1226 ret = -ENOENT;
1227 if (!pid_alive(proc_task(inode)))
1228 goto out;
1229
1230 ret = 0;
1231 pid = proc_task(inode)->pid;
1232 i = filp->f_pos;
1233 switch (i) {
1234 case 0:
1235 ino = inode->i_ino;
1236 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
1237 goto out;
1238 i++;
1239 filp->f_pos++;
1240 /* fall through */
1241 case 1:
1242 ino = parent_ino(dentry);
1243 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
1244 goto out;
1245 i++;
1246 filp->f_pos++;
1247 /* fall through */
1248 default:
1249 i -= 2;
1250 if (i >= nents) {
1251 ret = 1;
1252 goto out;
1253 }
1254 p = ents + i;
1255 while (p->name) {
1256 if (filldir(dirent, p->name, p->len, filp->f_pos,
1257 fake_ino(pid, p->type), p->mode >> 12) < 0)
1258 goto out;
1259 filp->f_pos++;
1260 p++;
1261 }
1262 }
1263
1264 ret = 1;
1265 out:
1266 return ret;
1267 }
1268
1269 static int proc_tgid_base_readdir(struct file * filp,
1270 void * dirent, filldir_t filldir)
1271 {
1272 return proc_pident_readdir(filp,dirent,filldir,
1273 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
1274 }
1275
1276 static int proc_tid_base_readdir(struct file * filp,
1277 void * dirent, filldir_t filldir)
1278 {
1279 return proc_pident_readdir(filp,dirent,filldir,
1280 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
1281 }
1282
1283 /* building an inode */
1284
1285 static int task_dumpable(struct task_struct *task)
1286 {
1287 int dumpable = 0;
1288 struct mm_struct *mm;
1289
1290 task_lock(task);
1291 mm = task->mm;
1292 if (mm)
1293 dumpable = mm->dumpable;
1294 task_unlock(task);
1295 if(dumpable == 1)
1296 return 1;
1297 return 0;
1298 }
1299
1300
1301 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task, int ino)
1302 {
1303 struct inode * inode;
1304 struct proc_inode *ei;
1305
1306 /* We need a new inode */
1307
1308 inode = new_inode(sb);
1309 if (!inode)
1310 goto out;
1311
1312 /* Common stuff */
1313 ei = PROC_I(inode);
1314 ei->task = NULL;
1315 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1316 inode->i_ino = fake_ino(task->pid, ino);
1317
1318 if (!pid_alive(task))
1319 goto out_unlock;
1320
1321 /*
1322 * grab the reference to task.
1323 */
1324 get_task_struct(task);
1325 ei->task = task;
1326 ei->type = ino;
1327 inode->i_uid = 0;
1328 inode->i_gid = 0;
1329 if (ino == PROC_TGID_INO || ino == PROC_TID_INO || task_dumpable(task)) {
1330 inode->i_uid = task->euid;
1331 inode->i_gid = task->egid;
1332 }
1333 security_task_to_inode(task, inode);
1334
1335 out:
1336 return inode;
1337
1338 out_unlock:
1339 ei->pde = NULL;
1340 iput(inode);
1341 return NULL;
1342 }
1343
1344 /* dentry stuff */
1345
1346 /*
1347 * Exceptional case: normally we are not allowed to unhash a busy
1348 * directory. In this case, however, we can do it - no aliasing problems
1349 * due to the way we treat inodes.
1350 *
1351 * Rewrite the inode's ownerships here because the owning task may have
1352 * performed a setuid(), etc.
1353 */
1354 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1355 {
1356 struct inode *inode = dentry->d_inode;
1357 struct task_struct *task = proc_task(inode);
1358 if (pid_alive(task)) {
1359 if (proc_type(inode) == PROC_TGID_INO || proc_type(inode) == PROC_TID_INO || task_dumpable(task)) {
1360 inode->i_uid = task->euid;
1361 inode->i_gid = task->egid;
1362 } else {
1363 inode->i_uid = 0;
1364 inode->i_gid = 0;
1365 }
1366 security_task_to_inode(task, inode);
1367 return 1;
1368 }
1369 d_drop(dentry);
1370 return 0;
1371 }
1372
1373 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1374 {
1375 struct inode *inode = dentry->d_inode;
1376 struct task_struct *task = proc_task(inode);
1377 int fd = proc_type(inode) - PROC_TID_FD_DIR;
1378 struct files_struct *files;
1379
1380 files = get_files_struct(task);
1381 if (files) {
1382 rcu_read_lock();
1383 if (fcheck_files(files, fd)) {
1384 rcu_read_unlock();
1385 put_files_struct(files);
1386 if (task_dumpable(task)) {
1387 inode->i_uid = task->euid;
1388 inode->i_gid = task->egid;
1389 } else {
1390 inode->i_uid = 0;
1391 inode->i_gid = 0;
1392 }
1393 security_task_to_inode(task, inode);
1394 return 1;
1395 }
1396 rcu_read_unlock();
1397 put_files_struct(files);
1398 }
1399 d_drop(dentry);
1400 return 0;
1401 }
1402
1403 static void pid_base_iput(struct dentry *dentry, struct inode *inode)
1404 {
1405 struct task_struct *task = proc_task(inode);
1406 spin_lock(&task->proc_lock);
1407 if (task->proc_dentry == dentry)
1408 task->proc_dentry = NULL;
1409 spin_unlock(&task->proc_lock);
1410 iput(inode);
1411 }
1412
1413 static int pid_delete_dentry(struct dentry * dentry)
1414 {
1415 /* Is the task we represent dead?
1416 * If so, then don't put the dentry on the lru list,
1417 * kill it immediately.
1418 */
1419 return !pid_alive(proc_task(dentry->d_inode));
1420 }
1421
1422 static struct dentry_operations tid_fd_dentry_operations =
1423 {
1424 .d_revalidate = tid_fd_revalidate,
1425 .d_delete = pid_delete_dentry,
1426 };
1427
1428 static struct dentry_operations pid_dentry_operations =
1429 {
1430 .d_revalidate = pid_revalidate,
1431 .d_delete = pid_delete_dentry,
1432 };
1433
1434 static struct dentry_operations pid_base_dentry_operations =
1435 {
1436 .d_revalidate = pid_revalidate,
1437 .d_iput = pid_base_iput,
1438 .d_delete = pid_delete_dentry,
1439 };
1440
1441 /* Lookups */
1442
1443 static unsigned name_to_int(struct dentry *dentry)
1444 {
1445 const char *name = dentry->d_name.name;
1446 int len = dentry->d_name.len;
1447 unsigned n = 0;
1448
1449 if (len > 1 && *name == '0')
1450 goto out;
1451 while (len-- > 0) {
1452 unsigned c = *name++ - '0';
1453 if (c > 9)
1454 goto out;
1455 if (n >= (~0U-9)/10)
1456 goto out;
1457 n *= 10;
1458 n += c;
1459 }
1460 return n;
1461 out:
1462 return ~0U;
1463 }
1464
1465 /* SMP-safe */
1466 static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
1467 {
1468 struct task_struct *task = proc_task(dir);
1469 unsigned fd = name_to_int(dentry);
1470 struct file * file;
1471 struct files_struct * files;
1472 struct inode *inode;
1473 struct proc_inode *ei;
1474
1475 if (fd == ~0U)
1476 goto out;
1477 if (!pid_alive(task))
1478 goto out;
1479
1480 inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_FD_DIR+fd);
1481 if (!inode)
1482 goto out;
1483 ei = PROC_I(inode);
1484 files = get_files_struct(task);
1485 if (!files)
1486 goto out_unlock;
1487 inode->i_mode = S_IFLNK;
1488 rcu_read_lock();
1489 file = fcheck_files(files, fd);
1490 if (!file)
1491 goto out_unlock2;
1492 if (file->f_mode & 1)
1493 inode->i_mode |= S_IRUSR | S_IXUSR;
1494 if (file->f_mode & 2)
1495 inode->i_mode |= S_IWUSR | S_IXUSR;
1496 rcu_read_unlock();
1497 put_files_struct(files);
1498 inode->i_op = &proc_pid_link_inode_operations;
1499 inode->i_size = 64;
1500 ei->op.proc_get_link = proc_fd_link;
1501 dentry->d_op = &tid_fd_dentry_operations;
1502 d_add(dentry, inode);
1503 return NULL;
1504
1505 out_unlock2:
1506 rcu_read_unlock();
1507 put_files_struct(files);
1508 out_unlock:
1509 iput(inode);
1510 out:
1511 return ERR_PTR(-ENOENT);
1512 }
1513
1514 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir);
1515 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd);
1516
1517 static struct file_operations proc_fd_operations = {
1518 .read = generic_read_dir,
1519 .readdir = proc_readfd,
1520 };
1521
1522 static struct file_operations proc_task_operations = {
1523 .read = generic_read_dir,
1524 .readdir = proc_task_readdir,
1525 };
1526
1527 /*
1528 * proc directories can do almost nothing..
1529 */
1530 static struct inode_operations proc_fd_inode_operations = {
1531 .lookup = proc_lookupfd,
1532 .permission = proc_permission,
1533 };
1534
1535 static struct inode_operations proc_task_inode_operations = {
1536 .lookup = proc_task_lookup,
1537 .permission = proc_task_permission,
1538 };
1539
1540 #ifdef CONFIG_SECURITY
1541 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
1542 size_t count, loff_t *ppos)
1543 {
1544 struct inode * inode = file->f_dentry->d_inode;
1545 unsigned long page;
1546 ssize_t length;
1547 struct task_struct *task = proc_task(inode);
1548
1549 if (count > PAGE_SIZE)
1550 count = PAGE_SIZE;
1551 if (!(page = __get_free_page(GFP_KERNEL)))
1552 return -ENOMEM;
1553
1554 length = security_getprocattr(task,
1555 (char*)file->f_dentry->d_name.name,
1556 (void*)page, count);
1557 if (length >= 0)
1558 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
1559 free_page(page);
1560 return length;
1561 }
1562
1563 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
1564 size_t count, loff_t *ppos)
1565 {
1566 struct inode * inode = file->f_dentry->d_inode;
1567 char *page;
1568 ssize_t length;
1569 struct task_struct *task = proc_task(inode);
1570
1571 if (count > PAGE_SIZE)
1572 count = PAGE_SIZE;
1573 if (*ppos != 0) {
1574 /* No partial writes. */
1575 return -EINVAL;
1576 }
1577 page = (char*)__get_free_page(GFP_USER);
1578 if (!page)
1579 return -ENOMEM;
1580 length = -EFAULT;
1581 if (copy_from_user(page, buf, count))
1582 goto out;
1583
1584 length = security_setprocattr(task,
1585 (char*)file->f_dentry->d_name.name,
1586 (void*)page, count);
1587 out:
1588 free_page((unsigned long) page);
1589 return length;
1590 }
1591
1592 static struct file_operations proc_pid_attr_operations = {
1593 .read = proc_pid_attr_read,
1594 .write = proc_pid_attr_write,
1595 };
1596
1597 static struct file_operations proc_tid_attr_operations;
1598 static struct inode_operations proc_tid_attr_inode_operations;
1599 static struct file_operations proc_tgid_attr_operations;
1600 static struct inode_operations proc_tgid_attr_inode_operations;
1601 #endif
1602
1603 static int get_tid_list(int index, unsigned int *tids, struct inode *dir);
1604
1605 /* SMP-safe */
1606 static struct dentry *proc_pident_lookup(struct inode *dir,
1607 struct dentry *dentry,
1608 struct pid_entry *ents)
1609 {
1610 struct inode *inode;
1611 int error;
1612 struct task_struct *task = proc_task(dir);
1613 struct pid_entry *p;
1614 struct proc_inode *ei;
1615
1616 error = -ENOENT;
1617 inode = NULL;
1618
1619 if (!pid_alive(task))
1620 goto out;
1621
1622 for (p = ents; p->name; p++) {
1623 if (p->len != dentry->d_name.len)
1624 continue;
1625 if (!memcmp(dentry->d_name.name, p->name, p->len))
1626 break;
1627 }
1628 if (!p->name)
1629 goto out;
1630
1631 error = -EINVAL;
1632 inode = proc_pid_make_inode(dir->i_sb, task, p->type);
1633 if (!inode)
1634 goto out;
1635
1636 ei = PROC_I(inode);
1637 inode->i_mode = p->mode;
1638 /*
1639 * Yes, it does not scale. And it should not. Don't add
1640 * new entries into /proc/<tgid>/ without very good reasons.
1641 */
1642 switch(p->type) {
1643 case PROC_TGID_TASK:
1644 inode->i_nlink = 2 + get_tid_list(2, NULL, dir);
1645 inode->i_op = &proc_task_inode_operations;
1646 inode->i_fop = &proc_task_operations;
1647 break;
1648 case PROC_TID_FD:
1649 case PROC_TGID_FD:
1650 inode->i_nlink = 2;
1651 inode->i_op = &proc_fd_inode_operations;
1652 inode->i_fop = &proc_fd_operations;
1653 break;
1654 case PROC_TID_EXE:
1655 case PROC_TGID_EXE:
1656 inode->i_op = &proc_pid_link_inode_operations;
1657 ei->op.proc_get_link = proc_exe_link;
1658 break;
1659 case PROC_TID_CWD:
1660 case PROC_TGID_CWD:
1661 inode->i_op = &proc_pid_link_inode_operations;
1662 ei->op.proc_get_link = proc_cwd_link;
1663 break;
1664 case PROC_TID_ROOT:
1665 case PROC_TGID_ROOT:
1666 inode->i_op = &proc_pid_link_inode_operations;
1667 ei->op.proc_get_link = proc_root_link;
1668 break;
1669 case PROC_TID_ENVIRON:
1670 case PROC_TGID_ENVIRON:
1671 inode->i_fop = &proc_info_file_operations;
1672 ei->op.proc_read = proc_pid_environ;
1673 break;
1674 case PROC_TID_AUXV:
1675 case PROC_TGID_AUXV:
1676 inode->i_fop = &proc_info_file_operations;
1677 ei->op.proc_read = proc_pid_auxv;
1678 break;
1679 case PROC_TID_STATUS:
1680 case PROC_TGID_STATUS:
1681 inode->i_fop = &proc_info_file_operations;
1682 ei->op.proc_read = proc_pid_status;
1683 break;
1684 case PROC_TID_STAT:
1685 inode->i_fop = &proc_info_file_operations;
1686 ei->op.proc_read = proc_tid_stat;
1687 break;
1688 case PROC_TGID_STAT:
1689 inode->i_fop = &proc_info_file_operations;
1690 ei->op.proc_read = proc_tgid_stat;
1691 break;
1692 case PROC_TID_CMDLINE:
1693 case PROC_TGID_CMDLINE:
1694 inode->i_fop = &proc_info_file_operations;
1695 ei->op.proc_read = proc_pid_cmdline;
1696 break;
1697 case PROC_TID_STATM:
1698 case PROC_TGID_STATM:
1699 inode->i_fop = &proc_info_file_operations;
1700 ei->op.proc_read = proc_pid_statm;
1701 break;
1702 case PROC_TID_MAPS:
1703 case PROC_TGID_MAPS:
1704 inode->i_fop = &proc_maps_operations;
1705 break;
1706 #ifdef CONFIG_NUMA
1707 case PROC_TID_NUMA_MAPS:
1708 case PROC_TGID_NUMA_MAPS:
1709 inode->i_fop = &proc_numa_maps_operations;
1710 break;
1711 #endif
1712 case PROC_TID_MEM:
1713 case PROC_TGID_MEM:
1714 inode->i_op = &proc_mem_inode_operations;
1715 inode->i_fop = &proc_mem_operations;
1716 break;
1717 #ifdef CONFIG_SECCOMP
1718 case PROC_TID_SECCOMP:
1719 case PROC_TGID_SECCOMP:
1720 inode->i_fop = &proc_seccomp_operations;
1721 break;
1722 #endif /* CONFIG_SECCOMP */
1723 case PROC_TID_MOUNTS:
1724 case PROC_TGID_MOUNTS:
1725 inode->i_fop = &proc_mounts_operations;
1726 break;
1727 #ifdef CONFIG_MMU
1728 case PROC_TID_SMAPS:
1729 case PROC_TGID_SMAPS:
1730 inode->i_fop = &proc_smaps_operations;
1731 break;
1732 #endif
1733 #ifdef CONFIG_SECURITY
1734 case PROC_TID_ATTR:
1735 inode->i_nlink = 2;
1736 inode->i_op = &proc_tid_attr_inode_operations;
1737 inode->i_fop = &proc_tid_attr_operations;
1738 break;
1739 case PROC_TGID_ATTR:
1740 inode->i_nlink = 2;
1741 inode->i_op = &proc_tgid_attr_inode_operations;
1742 inode->i_fop = &proc_tgid_attr_operations;
1743 break;
1744 case PROC_TID_ATTR_CURRENT:
1745 case PROC_TGID_ATTR_CURRENT:
1746 case PROC_TID_ATTR_PREV:
1747 case PROC_TGID_ATTR_PREV:
1748 case PROC_TID_ATTR_EXEC:
1749 case PROC_TGID_ATTR_EXEC:
1750 case PROC_TID_ATTR_FSCREATE:
1751 case PROC_TGID_ATTR_FSCREATE:
1752 inode->i_fop = &proc_pid_attr_operations;
1753 break;
1754 #endif
1755 #ifdef CONFIG_KALLSYMS
1756 case PROC_TID_WCHAN:
1757 case PROC_TGID_WCHAN:
1758 inode->i_fop = &proc_info_file_operations;
1759 ei->op.proc_read = proc_pid_wchan;
1760 break;
1761 #endif
1762 #ifdef CONFIG_SCHEDSTATS
1763 case PROC_TID_SCHEDSTAT:
1764 case PROC_TGID_SCHEDSTAT:
1765 inode->i_fop = &proc_info_file_operations;
1766 ei->op.proc_read = proc_pid_schedstat;
1767 break;
1768 #endif
1769 #ifdef CONFIG_CPUSETS
1770 case PROC_TID_CPUSET:
1771 case PROC_TGID_CPUSET:
1772 inode->i_fop = &proc_cpuset_operations;
1773 break;
1774 #endif
1775 case PROC_TID_OOM_SCORE:
1776 case PROC_TGID_OOM_SCORE:
1777 inode->i_fop = &proc_info_file_operations;
1778 ei->op.proc_read = proc_oom_score;
1779 break;
1780 case PROC_TID_OOM_ADJUST:
1781 case PROC_TGID_OOM_ADJUST:
1782 inode->i_fop = &proc_oom_adjust_operations;
1783 break;
1784 #ifdef CONFIG_AUDITSYSCALL
1785 case PROC_TID_LOGINUID:
1786 case PROC_TGID_LOGINUID:
1787 inode->i_fop = &proc_loginuid_operations;
1788 break;
1789 #endif
1790 default:
1791 printk("procfs: impossible type (%d)",p->type);
1792 iput(inode);
1793 return ERR_PTR(-EINVAL);
1794 }
1795 dentry->d_op = &pid_dentry_operations;
1796 d_add(dentry, inode);
1797 return NULL;
1798
1799 out:
1800 return ERR_PTR(error);
1801 }
1802
1803 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
1804 return proc_pident_lookup(dir, dentry, tgid_base_stuff);
1805 }
1806
1807 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
1808 return proc_pident_lookup(dir, dentry, tid_base_stuff);
1809 }
1810
1811 static struct file_operations proc_tgid_base_operations = {
1812 .read = generic_read_dir,
1813 .readdir = proc_tgid_base_readdir,
1814 };
1815
1816 static struct file_operations proc_tid_base_operations = {
1817 .read = generic_read_dir,
1818 .readdir = proc_tid_base_readdir,
1819 };
1820
1821 static struct inode_operations proc_tgid_base_inode_operations = {
1822 .lookup = proc_tgid_base_lookup,
1823 };
1824
1825 static struct inode_operations proc_tid_base_inode_operations = {
1826 .lookup = proc_tid_base_lookup,
1827 };
1828
1829 #ifdef CONFIG_SECURITY
1830 static int proc_tgid_attr_readdir(struct file * filp,
1831 void * dirent, filldir_t filldir)
1832 {
1833 return proc_pident_readdir(filp,dirent,filldir,
1834 tgid_attr_stuff,ARRAY_SIZE(tgid_attr_stuff));
1835 }
1836
1837 static int proc_tid_attr_readdir(struct file * filp,
1838 void * dirent, filldir_t filldir)
1839 {
1840 return proc_pident_readdir(filp,dirent,filldir,
1841 tid_attr_stuff,ARRAY_SIZE(tid_attr_stuff));
1842 }
1843
1844 static struct file_operations proc_tgid_attr_operations = {
1845 .read = generic_read_dir,
1846 .readdir = proc_tgid_attr_readdir,
1847 };
1848
1849 static struct file_operations proc_tid_attr_operations = {
1850 .read = generic_read_dir,
1851 .readdir = proc_tid_attr_readdir,
1852 };
1853
1854 static struct dentry *proc_tgid_attr_lookup(struct inode *dir,
1855 struct dentry *dentry, struct nameidata *nd)
1856 {
1857 return proc_pident_lookup(dir, dentry, tgid_attr_stuff);
1858 }
1859
1860 static struct dentry *proc_tid_attr_lookup(struct inode *dir,
1861 struct dentry *dentry, struct nameidata *nd)
1862 {
1863 return proc_pident_lookup(dir, dentry, tid_attr_stuff);
1864 }
1865
1866 static struct inode_operations proc_tgid_attr_inode_operations = {
1867 .lookup = proc_tgid_attr_lookup,
1868 };
1869
1870 static struct inode_operations proc_tid_attr_inode_operations = {
1871 .lookup = proc_tid_attr_lookup,
1872 };
1873 #endif
1874
1875 /*
1876 * /proc/self:
1877 */
1878 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
1879 int buflen)
1880 {
1881 char tmp[30];
1882 sprintf(tmp, "%d", current->tgid);
1883 return vfs_readlink(dentry,buffer,buflen,tmp);
1884 }
1885
1886 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
1887 {
1888 char tmp[30];
1889 sprintf(tmp, "%d", current->tgid);
1890 return ERR_PTR(vfs_follow_link(nd,tmp));
1891 }
1892
1893 static struct inode_operations proc_self_inode_operations = {
1894 .readlink = proc_self_readlink,
1895 .follow_link = proc_self_follow_link,
1896 };
1897
1898 /**
1899 * proc_pid_unhash - Unhash /proc/@pid entry from the dcache.
1900 * @p: task that should be flushed.
1901 *
1902 * Drops the /proc/@pid dcache entry from the hash chains.
1903 *
1904 * Dropping /proc/@pid entries and detach_pid must be synchroneous,
1905 * otherwise e.g. /proc/@pid/exe might point to the wrong executable,
1906 * if the pid value is immediately reused. This is enforced by
1907 * - caller must acquire spin_lock(p->proc_lock)
1908 * - must be called before detach_pid()
1909 * - proc_pid_lookup acquires proc_lock, and checks that
1910 * the target is not dead by looking at the attach count
1911 * of PIDTYPE_PID.
1912 */
1913
1914 struct dentry *proc_pid_unhash(struct task_struct *p)
1915 {
1916 struct dentry *proc_dentry;
1917
1918 proc_dentry = p->proc_dentry;
1919 if (proc_dentry != NULL) {
1920
1921 spin_lock(&dcache_lock);
1922 spin_lock(&proc_dentry->d_lock);
1923 if (!d_unhashed(proc_dentry)) {
1924 dget_locked(proc_dentry);
1925 __d_drop(proc_dentry);
1926 spin_unlock(&proc_dentry->d_lock);
1927 } else {
1928 spin_unlock(&proc_dentry->d_lock);
1929 proc_dentry = NULL;
1930 }
1931 spin_unlock(&dcache_lock);
1932 }
1933 return proc_dentry;
1934 }
1935
1936 /**
1937 * proc_pid_flush - recover memory used by stale /proc/@pid/x entries
1938 * @proc_dentry: directoy to prune.
1939 *
1940 * Shrink the /proc directory that was used by the just killed thread.
1941 */
1942
1943 void proc_pid_flush(struct dentry *proc_dentry)
1944 {
1945 might_sleep();
1946 if(proc_dentry != NULL) {
1947 shrink_dcache_parent(proc_dentry);
1948 dput(proc_dentry);
1949 }
1950 }
1951
1952 /* SMP-safe */
1953 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
1954 {
1955 struct task_struct *task;
1956 struct inode *inode;
1957 struct proc_inode *ei;
1958 unsigned tgid;
1959 int died;
1960
1961 if (dentry->d_name.len == 4 && !memcmp(dentry->d_name.name,"self",4)) {
1962 inode = new_inode(dir->i_sb);
1963 if (!inode)
1964 return ERR_PTR(-ENOMEM);
1965 ei = PROC_I(inode);
1966 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1967 inode->i_ino = fake_ino(0, PROC_TGID_INO);
1968 ei->pde = NULL;
1969 inode->i_mode = S_IFLNK|S_IRWXUGO;
1970 inode->i_uid = inode->i_gid = 0;
1971 inode->i_size = 64;
1972 inode->i_op = &proc_self_inode_operations;
1973 d_add(dentry, inode);
1974 return NULL;
1975 }
1976 tgid = name_to_int(dentry);
1977 if (tgid == ~0U)
1978 goto out;
1979
1980 read_lock(&tasklist_lock);
1981 task = find_task_by_pid(tgid);
1982 if (task)
1983 get_task_struct(task);
1984 read_unlock(&tasklist_lock);
1985 if (!task)
1986 goto out;
1987
1988 inode = proc_pid_make_inode(dir->i_sb, task, PROC_TGID_INO);
1989
1990
1991 if (!inode) {
1992 put_task_struct(task);
1993 goto out;
1994 }
1995 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
1996 inode->i_op = &proc_tgid_base_inode_operations;
1997 inode->i_fop = &proc_tgid_base_operations;
1998 inode->i_flags|=S_IMMUTABLE;
1999 #ifdef CONFIG_SECURITY
2000 inode->i_nlink = 5;
2001 #else
2002 inode->i_nlink = 4;
2003 #endif
2004
2005 dentry->d_op = &pid_base_dentry_operations;
2006
2007 died = 0;
2008 d_add(dentry, inode);
2009 spin_lock(&task->proc_lock);
2010 task->proc_dentry = dentry;
2011 if (!pid_alive(task)) {
2012 dentry = proc_pid_unhash(task);
2013 died = 1;
2014 }
2015 spin_unlock(&task->proc_lock);
2016
2017 put_task_struct(task);
2018 if (died) {
2019 proc_pid_flush(dentry);
2020 goto out;
2021 }
2022 return NULL;
2023 out:
2024 return ERR_PTR(-ENOENT);
2025 }
2026
2027 /* SMP-safe */
2028 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2029 {
2030 struct task_struct *task;
2031 struct task_struct *leader = proc_task(dir);
2032 struct inode *inode;
2033 unsigned tid;
2034
2035 tid = name_to_int(dentry);
2036 if (tid == ~0U)
2037 goto out;
2038
2039 read_lock(&tasklist_lock);
2040 task = find_task_by_pid(tid);
2041 if (task)
2042 get_task_struct(task);
2043 read_unlock(&tasklist_lock);
2044 if (!task)
2045 goto out;
2046 if (leader->tgid != task->tgid)
2047 goto out_drop_task;
2048
2049 inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_INO);
2050
2051
2052 if (!inode)
2053 goto out_drop_task;
2054 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2055 inode->i_op = &proc_tid_base_inode_operations;
2056 inode->i_fop = &proc_tid_base_operations;
2057 inode->i_flags|=S_IMMUTABLE;
2058 #ifdef CONFIG_SECURITY
2059 inode->i_nlink = 4;
2060 #else
2061 inode->i_nlink = 3;
2062 #endif
2063
2064 dentry->d_op = &pid_base_dentry_operations;
2065
2066 d_add(dentry, inode);
2067
2068 put_task_struct(task);
2069 return NULL;
2070 out_drop_task:
2071 put_task_struct(task);
2072 out:
2073 return ERR_PTR(-ENOENT);
2074 }
2075
2076 #define PROC_NUMBUF 10
2077 #define PROC_MAXPIDS 20
2078
2079 /*
2080 * Get a few tgid's to return for filldir - we need to hold the
2081 * tasklist lock while doing this, and we must release it before
2082 * we actually do the filldir itself, so we use a temp buffer..
2083 */
2084 static int get_tgid_list(int index, unsigned long version, unsigned int *tgids)
2085 {
2086 struct task_struct *p;
2087 int nr_tgids = 0;
2088
2089 index--;
2090 read_lock(&tasklist_lock);
2091 p = NULL;
2092 if (version) {
2093 p = find_task_by_pid(version);
2094 if (p && !thread_group_leader(p))
2095 p = NULL;
2096 }
2097
2098 if (p)
2099 index = 0;
2100 else
2101 p = next_task(&init_task);
2102
2103 for ( ; p != &init_task; p = next_task(p)) {
2104 int tgid = p->pid;
2105 if (!pid_alive(p))
2106 continue;
2107 if (--index >= 0)
2108 continue;
2109 tgids[nr_tgids] = tgid;
2110 nr_tgids++;
2111 if (nr_tgids >= PROC_MAXPIDS)
2112 break;
2113 }
2114 read_unlock(&tasklist_lock);
2115 return nr_tgids;
2116 }
2117
2118 /*
2119 * Get a few tid's to return for filldir - we need to hold the
2120 * tasklist lock while doing this, and we must release it before
2121 * we actually do the filldir itself, so we use a temp buffer..
2122 */
2123 static int get_tid_list(int index, unsigned int *tids, struct inode *dir)
2124 {
2125 struct task_struct *leader_task = proc_task(dir);
2126 struct task_struct *task = leader_task;
2127 int nr_tids = 0;
2128
2129 index -= 2;
2130 read_lock(&tasklist_lock);
2131 /*
2132 * The starting point task (leader_task) might be an already
2133 * unlinked task, which cannot be used to access the task-list
2134 * via next_thread().
2135 */
2136 if (pid_alive(task)) do {
2137 int tid = task->pid;
2138
2139 if (--index >= 0)
2140 continue;
2141 if (tids != NULL)
2142 tids[nr_tids] = tid;
2143 nr_tids++;
2144 if (nr_tids >= PROC_MAXPIDS)
2145 break;
2146 } while ((task = next_thread(task)) != leader_task);
2147 read_unlock(&tasklist_lock);
2148 return nr_tids;
2149 }
2150
2151 /* for the /proc/ directory itself, after non-process stuff has been done */
2152 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2153 {
2154 unsigned int tgid_array[PROC_MAXPIDS];
2155 char buf[PROC_NUMBUF];
2156 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2157 unsigned int nr_tgids, i;
2158 int next_tgid;
2159
2160 if (!nr) {
2161 ino_t ino = fake_ino(0,PROC_TGID_INO);
2162 if (filldir(dirent, "self", 4, filp->f_pos, ino, DT_LNK) < 0)
2163 return 0;
2164 filp->f_pos++;
2165 nr++;
2166 }
2167
2168 /* f_version caches the tgid value that the last readdir call couldn't
2169 * return. lseek aka telldir automagically resets f_version to 0.
2170 */
2171 next_tgid = filp->f_version;
2172 filp->f_version = 0;
2173 for (;;) {
2174 nr_tgids = get_tgid_list(nr, next_tgid, tgid_array);
2175 if (!nr_tgids) {
2176 /* no more entries ! */
2177 break;
2178 }
2179 next_tgid = 0;
2180
2181 /* do not use the last found pid, reserve it for next_tgid */
2182 if (nr_tgids == PROC_MAXPIDS) {
2183 nr_tgids--;
2184 next_tgid = tgid_array[nr_tgids];
2185 }
2186
2187 for (i=0;i<nr_tgids;i++) {
2188 int tgid = tgid_array[i];
2189 ino_t ino = fake_ino(tgid,PROC_TGID_INO);
2190 unsigned long j = PROC_NUMBUF;
2191
2192 do
2193 buf[--j] = '0' + (tgid % 10);
2194 while ((tgid /= 10) != 0);
2195
2196 if (filldir(dirent, buf+j, PROC_NUMBUF-j, filp->f_pos, ino, DT_DIR) < 0) {
2197 /* returning this tgid failed, save it as the first
2198 * pid for the next readir call */
2199 filp->f_version = tgid_array[i];
2200 goto out;
2201 }
2202 filp->f_pos++;
2203 nr++;
2204 }
2205 }
2206 out:
2207 return 0;
2208 }
2209
2210 /* for the /proc/TGID/task/ directories */
2211 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
2212 {
2213 unsigned int tid_array[PROC_MAXPIDS];
2214 char buf[PROC_NUMBUF];
2215 unsigned int nr_tids, i;
2216 struct dentry *dentry = filp->f_dentry;
2217 struct inode *inode = dentry->d_inode;
2218 int retval = -ENOENT;
2219 ino_t ino;
2220 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */
2221
2222 if (!pid_alive(proc_task(inode)))
2223 goto out;
2224 retval = 0;
2225
2226 switch (pos) {
2227 case 0:
2228 ino = inode->i_ino;
2229 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0)
2230 goto out;
2231 pos++;
2232 /* fall through */
2233 case 1:
2234 ino = parent_ino(dentry);
2235 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0)
2236 goto out;
2237 pos++;
2238 /* fall through */
2239 }
2240
2241 nr_tids = get_tid_list(pos, tid_array, inode);
2242 inode->i_nlink = pos + nr_tids;
2243
2244 for (i = 0; i < nr_tids; i++) {
2245 unsigned long j = PROC_NUMBUF;
2246 int tid = tid_array[i];
2247
2248 ino = fake_ino(tid,PROC_TID_INO);
2249
2250 do
2251 buf[--j] = '0' + (tid % 10);
2252 while ((tid /= 10) != 0);
2253
2254 if (filldir(dirent, buf+j, PROC_NUMBUF-j, pos, ino, DT_DIR) < 0)
2255 break;
2256 pos++;
2257 }
2258 out:
2259 filp->f_pos = pos;
2260 return retval;
2261 }
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