3b33f94020db827f6563ec5f978165d4711dc907
[linux-2.6.git] / fs / proc / base.c
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/file.h>
59 #include <linux/string.h>
60 #include <linux/seq_file.h>
61 #include <linux/namei.h>
62 #include <linux/namespace.h>
63 #include <linux/mm.h>
64 #include <linux/smp_lock.h>
65 #include <linux/rcupdate.h>
66 #include <linux/kallsyms.h>
67 #include <linux/mount.h>
68 #include <linux/security.h>
69 #include <linux/ptrace.h>
70 #include <linux/seccomp.h>
71 #include <linux/cpuset.h>
72 #include <linux/audit.h>
73 #include "internal.h"
74
75 /*
76  * For hysterical raisins we keep the same inumbers as in the old procfs.
77  * Feel free to change the macro below - just keep the range distinct from
78  * inumbers of the rest of procfs (currently those are in 0x0000--0xffff).
79  * As soon as we'll get a separate superblock we will be able to forget
80  * about magical ranges too.
81  */
82
83 #define fake_ino(pid,ino) (((pid)<<16)|(ino))
84
85 enum pid_directory_inos {
86         PROC_TGID_INO = 2,
87         PROC_TGID_TASK,
88         PROC_TGID_STATUS,
89         PROC_TGID_MEM,
90 #ifdef CONFIG_SECCOMP
91         PROC_TGID_SECCOMP,
92 #endif
93         PROC_TGID_CWD,
94         PROC_TGID_ROOT,
95         PROC_TGID_EXE,
96         PROC_TGID_FD,
97         PROC_TGID_ENVIRON,
98         PROC_TGID_AUXV,
99         PROC_TGID_CMDLINE,
100         PROC_TGID_STAT,
101         PROC_TGID_STATM,
102         PROC_TGID_MAPS,
103         PROC_TGID_NUMA_MAPS,
104         PROC_TGID_MOUNTS,
105         PROC_TGID_WCHAN,
106         PROC_TGID_SMAPS,
107 #ifdef CONFIG_SCHEDSTATS
108         PROC_TGID_SCHEDSTAT,
109 #endif
110 #ifdef CONFIG_CPUSETS
111         PROC_TGID_CPUSET,
112 #endif
113 #ifdef CONFIG_SECURITY
114         PROC_TGID_ATTR,
115         PROC_TGID_ATTR_CURRENT,
116         PROC_TGID_ATTR_PREV,
117         PROC_TGID_ATTR_EXEC,
118         PROC_TGID_ATTR_FSCREATE,
119 #endif
120 #ifdef CONFIG_AUDITSYSCALL
121         PROC_TGID_LOGINUID,
122 #endif
123         PROC_TGID_OOM_SCORE,
124         PROC_TGID_OOM_ADJUST,
125         PROC_TID_INO,
126         PROC_TID_STATUS,
127         PROC_TID_MEM,
128 #ifdef CONFIG_SECCOMP
129         PROC_TID_SECCOMP,
130 #endif
131         PROC_TID_CWD,
132         PROC_TID_ROOT,
133         PROC_TID_EXE,
134         PROC_TID_FD,
135         PROC_TID_ENVIRON,
136         PROC_TID_AUXV,
137         PROC_TID_CMDLINE,
138         PROC_TID_STAT,
139         PROC_TID_STATM,
140         PROC_TID_MAPS,
141         PROC_TID_NUMA_MAPS,
142         PROC_TID_MOUNTS,
143         PROC_TID_WCHAN,
144         PROC_TID_SMAPS,
145 #ifdef CONFIG_SCHEDSTATS
146         PROC_TID_SCHEDSTAT,
147 #endif
148 #ifdef CONFIG_CPUSETS
149         PROC_TID_CPUSET,
150 #endif
151 #ifdef CONFIG_SECURITY
152         PROC_TID_ATTR,
153         PROC_TID_ATTR_CURRENT,
154         PROC_TID_ATTR_PREV,
155         PROC_TID_ATTR_EXEC,
156         PROC_TID_ATTR_FSCREATE,
157 #endif
158 #ifdef CONFIG_AUDITSYSCALL
159         PROC_TID_LOGINUID,
160 #endif
161         PROC_TID_OOM_SCORE,
162         PROC_TID_OOM_ADJUST,
163
164         /* Add new entries before this */
165         PROC_TID_FD_DIR = 0x8000,       /* 0x8000-0xffff */
166 };
167
168 struct pid_entry {
169         int type;
170         int len;
171         char *name;
172         mode_t mode;
173 };
174
175 #define E(type,name,mode) {(type),sizeof(name)-1,(name),(mode)}
176
177 static struct pid_entry tgid_base_stuff[] = {
178         E(PROC_TGID_TASK,      "task",    S_IFDIR|S_IRUGO|S_IXUGO),
179         E(PROC_TGID_FD,        "fd",      S_IFDIR|S_IRUSR|S_IXUSR),
180         E(PROC_TGID_ENVIRON,   "environ", S_IFREG|S_IRUSR),
181         E(PROC_TGID_AUXV,      "auxv",    S_IFREG|S_IRUSR),
182         E(PROC_TGID_STATUS,    "status",  S_IFREG|S_IRUGO),
183         E(PROC_TGID_CMDLINE,   "cmdline", S_IFREG|S_IRUGO),
184         E(PROC_TGID_STAT,      "stat",    S_IFREG|S_IRUGO),
185         E(PROC_TGID_STATM,     "statm",   S_IFREG|S_IRUGO),
186         E(PROC_TGID_MAPS,      "maps",    S_IFREG|S_IRUGO),
187 #ifdef CONFIG_NUMA
188         E(PROC_TGID_NUMA_MAPS, "numa_maps", S_IFREG|S_IRUGO),
189 #endif
190         E(PROC_TGID_MEM,       "mem",     S_IFREG|S_IRUSR|S_IWUSR),
191 #ifdef CONFIG_SECCOMP
192         E(PROC_TGID_SECCOMP,   "seccomp", S_IFREG|S_IRUSR|S_IWUSR),
193 #endif
194         E(PROC_TGID_CWD,       "cwd",     S_IFLNK|S_IRWXUGO),
195         E(PROC_TGID_ROOT,      "root",    S_IFLNK|S_IRWXUGO),
196         E(PROC_TGID_EXE,       "exe",     S_IFLNK|S_IRWXUGO),
197         E(PROC_TGID_MOUNTS,    "mounts",  S_IFREG|S_IRUGO),
198         E(PROC_TGID_SMAPS,     "smaps",   S_IFREG|S_IRUGO),
199 #ifdef CONFIG_SECURITY
200         E(PROC_TGID_ATTR,      "attr",    S_IFDIR|S_IRUGO|S_IXUGO),
201 #endif
202 #ifdef CONFIG_KALLSYMS
203         E(PROC_TGID_WCHAN,     "wchan",   S_IFREG|S_IRUGO),
204 #endif
205 #ifdef CONFIG_SCHEDSTATS
206         E(PROC_TGID_SCHEDSTAT, "schedstat", S_IFREG|S_IRUGO),
207 #endif
208 #ifdef CONFIG_CPUSETS
209         E(PROC_TGID_CPUSET,    "cpuset",  S_IFREG|S_IRUGO),
210 #endif
211         E(PROC_TGID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO),
212         E(PROC_TGID_OOM_ADJUST,"oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
213 #ifdef CONFIG_AUDITSYSCALL
214         E(PROC_TGID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO),
215 #endif
216         {0,0,NULL,0}
217 };
218 static struct pid_entry tid_base_stuff[] = {
219         E(PROC_TID_FD,         "fd",      S_IFDIR|S_IRUSR|S_IXUSR),
220         E(PROC_TID_ENVIRON,    "environ", S_IFREG|S_IRUSR),
221         E(PROC_TID_AUXV,       "auxv",    S_IFREG|S_IRUSR),
222         E(PROC_TID_STATUS,     "status",  S_IFREG|S_IRUGO),
223         E(PROC_TID_CMDLINE,    "cmdline", S_IFREG|S_IRUGO),
224         E(PROC_TID_STAT,       "stat",    S_IFREG|S_IRUGO),
225         E(PROC_TID_STATM,      "statm",   S_IFREG|S_IRUGO),
226         E(PROC_TID_MAPS,       "maps",    S_IFREG|S_IRUGO),
227 #ifdef CONFIG_NUMA
228         E(PROC_TID_NUMA_MAPS,  "numa_maps",    S_IFREG|S_IRUGO),
229 #endif
230         E(PROC_TID_MEM,        "mem",     S_IFREG|S_IRUSR|S_IWUSR),
231 #ifdef CONFIG_SECCOMP
232         E(PROC_TID_SECCOMP,    "seccomp", S_IFREG|S_IRUSR|S_IWUSR),
233 #endif
234         E(PROC_TID_CWD,        "cwd",     S_IFLNK|S_IRWXUGO),
235         E(PROC_TID_ROOT,       "root",    S_IFLNK|S_IRWXUGO),
236         E(PROC_TID_EXE,        "exe",     S_IFLNK|S_IRWXUGO),
237         E(PROC_TID_MOUNTS,     "mounts",  S_IFREG|S_IRUGO),
238         E(PROC_TID_SMAPS,      "smaps",   S_IFREG|S_IRUGO),
239 #ifdef CONFIG_SECURITY
240         E(PROC_TID_ATTR,       "attr",    S_IFDIR|S_IRUGO|S_IXUGO),
241 #endif
242 #ifdef CONFIG_KALLSYMS
243         E(PROC_TID_WCHAN,      "wchan",   S_IFREG|S_IRUGO),
244 #endif
245 #ifdef CONFIG_SCHEDSTATS
246         E(PROC_TID_SCHEDSTAT, "schedstat",S_IFREG|S_IRUGO),
247 #endif
248 #ifdef CONFIG_CPUSETS
249         E(PROC_TID_CPUSET,     "cpuset",  S_IFREG|S_IRUGO),
250 #endif
251         E(PROC_TID_OOM_SCORE,  "oom_score",S_IFREG|S_IRUGO),
252         E(PROC_TID_OOM_ADJUST, "oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
253 #ifdef CONFIG_AUDITSYSCALL
254         E(PROC_TID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO),
255 #endif
256         {0,0,NULL,0}
257 };
258
259 #ifdef CONFIG_SECURITY
260 static struct pid_entry tgid_attr_stuff[] = {
261         E(PROC_TGID_ATTR_CURRENT,  "current",  S_IFREG|S_IRUGO|S_IWUGO),
262         E(PROC_TGID_ATTR_PREV,     "prev",     S_IFREG|S_IRUGO),
263         E(PROC_TGID_ATTR_EXEC,     "exec",     S_IFREG|S_IRUGO|S_IWUGO),
264         E(PROC_TGID_ATTR_FSCREATE, "fscreate", S_IFREG|S_IRUGO|S_IWUGO),
265         {0,0,NULL,0}
266 };
267 static struct pid_entry tid_attr_stuff[] = {
268         E(PROC_TID_ATTR_CURRENT,   "current",  S_IFREG|S_IRUGO|S_IWUGO),
269         E(PROC_TID_ATTR_PREV,      "prev",     S_IFREG|S_IRUGO),
270         E(PROC_TID_ATTR_EXEC,      "exec",     S_IFREG|S_IRUGO|S_IWUGO),
271         E(PROC_TID_ATTR_FSCREATE,  "fscreate", S_IFREG|S_IRUGO|S_IWUGO),
272         {0,0,NULL,0}
273 };
274 #endif
275
276 #undef E
277
278 static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
279 {
280         struct task_struct *task = proc_task(inode);
281         struct files_struct *files;
282         struct file *file;
283         int fd = proc_type(inode) - PROC_TID_FD_DIR;
284
285         files = get_files_struct(task);
286         if (files) {
287                 rcu_read_lock();
288                 file = fcheck_files(files, fd);
289                 if (file) {
290                         *mnt = mntget(file->f_vfsmnt);
291                         *dentry = dget(file->f_dentry);
292                         rcu_read_unlock();
293                         put_files_struct(files);
294                         return 0;
295                 }
296                 rcu_read_unlock();
297                 put_files_struct(files);
298         }
299         return -ENOENT;
300 }
301
302 static struct fs_struct *get_fs_struct(struct task_struct *task)
303 {
304         struct fs_struct *fs;
305         task_lock(task);
306         fs = task->fs;
307         if(fs)
308                 atomic_inc(&fs->count);
309         task_unlock(task);
310         return fs;
311 }
312
313 static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
314 {
315         struct fs_struct *fs = get_fs_struct(proc_task(inode));
316         int result = -ENOENT;
317         if (fs) {
318                 read_lock(&fs->lock);
319                 *mnt = mntget(fs->pwdmnt);
320                 *dentry = dget(fs->pwd);
321                 read_unlock(&fs->lock);
322                 result = 0;
323                 put_fs_struct(fs);
324         }
325         return result;
326 }
327
328 static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
329 {
330         struct fs_struct *fs = get_fs_struct(proc_task(inode));
331         int result = -ENOENT;
332         if (fs) {
333                 read_lock(&fs->lock);
334                 *mnt = mntget(fs->rootmnt);
335                 *dentry = dget(fs->root);
336                 read_unlock(&fs->lock);
337                 result = 0;
338                 put_fs_struct(fs);
339         }
340         return result;
341 }
342
343
344 /* Same as proc_root_link, but this addionally tries to get fs from other
345  * threads in the group */
346 static int proc_task_root_link(struct inode *inode, struct dentry **dentry,
347                                 struct vfsmount **mnt)
348 {
349         struct fs_struct *fs;
350         int result = -ENOENT;
351         struct task_struct *leader = proc_task(inode);
352
353         task_lock(leader);
354         fs = leader->fs;
355         if (fs) {
356                 atomic_inc(&fs->count);
357                 task_unlock(leader);
358         } else {
359                 /* Try to get fs from other threads */
360                 task_unlock(leader);
361                 read_lock(&tasklist_lock);
362                 if (pid_alive(leader)) {
363                         struct task_struct *task = leader;
364
365                         while ((task = next_thread(task)) != leader) {
366                                 task_lock(task);
367                                 fs = task->fs;
368                                 if (fs) {
369                                         atomic_inc(&fs->count);
370                                         task_unlock(task);
371                                         break;
372                                 }
373                                 task_unlock(task);
374                         }
375                 }
376                 read_unlock(&tasklist_lock);
377         }
378
379         if (fs) {
380                 read_lock(&fs->lock);
381                 *mnt = mntget(fs->rootmnt);
382                 *dentry = dget(fs->root);
383                 read_unlock(&fs->lock);
384                 result = 0;
385                 put_fs_struct(fs);
386         }
387         return result;
388 }
389
390
391 #define MAY_PTRACE(task) \
392         (task == current || \
393         (task->parent == current && \
394         (task->ptrace & PT_PTRACED) && \
395          (task->state == TASK_STOPPED || task->state == TASK_TRACED) && \
396          security_ptrace(current,task) == 0))
397
398 static int proc_pid_environ(struct task_struct *task, char * buffer)
399 {
400         int res = 0;
401         struct mm_struct *mm = get_task_mm(task);
402         if (mm) {
403                 unsigned int len = mm->env_end - mm->env_start;
404                 if (len > PAGE_SIZE)
405                         len = PAGE_SIZE;
406                 res = access_process_vm(task, mm->env_start, buffer, len, 0);
407                 if (!ptrace_may_attach(task))
408                         res = -ESRCH;
409                 mmput(mm);
410         }
411         return res;
412 }
413
414 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
415 {
416         int res = 0;
417         unsigned int len;
418         struct mm_struct *mm = get_task_mm(task);
419         if (!mm)
420                 goto out;
421         if (!mm->arg_end)
422                 goto out_mm;    /* Shh! No looking before we're done */
423
424         len = mm->arg_end - mm->arg_start;
425  
426         if (len > PAGE_SIZE)
427                 len = PAGE_SIZE;
428  
429         res = access_process_vm(task, mm->arg_start, buffer, len, 0);
430
431         // If the nul at the end of args has been overwritten, then
432         // assume application is using setproctitle(3).
433         if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
434                 len = strnlen(buffer, res);
435                 if (len < res) {
436                     res = len;
437                 } else {
438                         len = mm->env_end - mm->env_start;
439                         if (len > PAGE_SIZE - res)
440                                 len = PAGE_SIZE - res;
441                         res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
442                         res = strnlen(buffer, res);
443                 }
444         }
445 out_mm:
446         mmput(mm);
447 out:
448         return res;
449 }
450
451 static int proc_pid_auxv(struct task_struct *task, char *buffer)
452 {
453         int res = 0;
454         struct mm_struct *mm = get_task_mm(task);
455         if (mm) {
456                 unsigned int nwords = 0;
457                 do
458                         nwords += 2;
459                 while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
460                 res = nwords * sizeof(mm->saved_auxv[0]);
461                 if (res > PAGE_SIZE)
462                         res = PAGE_SIZE;
463                 memcpy(buffer, mm->saved_auxv, res);
464                 mmput(mm);
465         }
466         return res;
467 }
468
469
470 #ifdef CONFIG_KALLSYMS
471 /*
472  * Provides a wchan file via kallsyms in a proper one-value-per-file format.
473  * Returns the resolved symbol.  If that fails, simply return the address.
474  */
475 static int proc_pid_wchan(struct task_struct *task, char *buffer)
476 {
477         char *modname;
478         const char *sym_name;
479         unsigned long wchan, size, offset;
480         char namebuf[KSYM_NAME_LEN+1];
481
482         wchan = get_wchan(task);
483
484         sym_name = kallsyms_lookup(wchan, &size, &offset, &modname, namebuf);
485         if (sym_name)
486                 return sprintf(buffer, "%s", sym_name);
487         return sprintf(buffer, "%lu", wchan);
488 }
489 #endif /* CONFIG_KALLSYMS */
490
491 #ifdef CONFIG_SCHEDSTATS
492 /*
493  * Provides /proc/PID/schedstat
494  */
495 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
496 {
497         return sprintf(buffer, "%lu %lu %lu\n",
498                         task->sched_info.cpu_time,
499                         task->sched_info.run_delay,
500                         task->sched_info.pcnt);
501 }
502 #endif
503
504 /* The badness from the OOM killer */
505 unsigned long badness(struct task_struct *p, unsigned long uptime);
506 static int proc_oom_score(struct task_struct *task, char *buffer)
507 {
508         unsigned long points;
509         struct timespec uptime;
510
511         do_posix_clock_monotonic_gettime(&uptime);
512         points = badness(task, uptime.tv_sec);
513         return sprintf(buffer, "%lu\n", points);
514 }
515
516 /************************************************************************/
517 /*                       Here the fs part begins                        */
518 /************************************************************************/
519
520 /* permission checks */
521
522 /* If the process being read is separated by chroot from the reading process,
523  * don't let the reader access the threads.
524  */
525 static int proc_check_chroot(struct dentry *root, struct vfsmount *vfsmnt)
526 {
527         struct dentry *de, *base;
528         struct vfsmount *our_vfsmnt, *mnt;
529         int res = 0;
530         read_lock(&current->fs->lock);
531         our_vfsmnt = mntget(current->fs->rootmnt);
532         base = dget(current->fs->root);
533         read_unlock(&current->fs->lock);
534
535         spin_lock(&vfsmount_lock);
536         de = root;
537         mnt = vfsmnt;
538
539         while (vfsmnt != our_vfsmnt) {
540                 if (vfsmnt == vfsmnt->mnt_parent)
541                         goto out;
542                 de = vfsmnt->mnt_mountpoint;
543                 vfsmnt = vfsmnt->mnt_parent;
544         }
545
546         if (!is_subdir(de, base))
547                 goto out;
548         spin_unlock(&vfsmount_lock);
549
550 exit:
551         dput(base);
552         mntput(our_vfsmnt);
553         dput(root);
554         mntput(mnt);
555         return res;
556 out:
557         spin_unlock(&vfsmount_lock);
558         res = -EACCES;
559         goto exit;
560 }
561
562 static int proc_check_root(struct inode *inode)
563 {
564         struct dentry *root;
565         struct vfsmount *vfsmnt;
566
567         if (proc_root_link(inode, &root, &vfsmnt)) /* Ewww... */
568                 return -ENOENT;
569         return proc_check_chroot(root, vfsmnt);
570 }
571
572 static int proc_permission(struct inode *inode, int mask, struct nameidata *nd)
573 {
574         if (generic_permission(inode, mask, NULL) != 0)
575                 return -EACCES;
576         return proc_check_root(inode);
577 }
578
579 static int proc_task_permission(struct inode *inode, int mask, struct nameidata *nd)
580 {
581         struct dentry *root;
582         struct vfsmount *vfsmnt;
583
584         if (generic_permission(inode, mask, NULL) != 0)
585                 return -EACCES;
586
587         if (proc_task_root_link(inode, &root, &vfsmnt))
588                 return -ENOENT;
589
590         return proc_check_chroot(root, vfsmnt);
591 }
592
593 extern struct seq_operations proc_pid_maps_op;
594 static int maps_open(struct inode *inode, struct file *file)
595 {
596         struct task_struct *task = proc_task(inode);
597         int ret = seq_open(file, &proc_pid_maps_op);
598         if (!ret) {
599                 struct seq_file *m = file->private_data;
600                 m->private = task;
601         }
602         return ret;
603 }
604
605 static struct file_operations proc_maps_operations = {
606         .open           = maps_open,
607         .read           = seq_read,
608         .llseek         = seq_lseek,
609         .release        = seq_release,
610 };
611
612 #ifdef CONFIG_NUMA
613 extern struct seq_operations proc_pid_numa_maps_op;
614 static int numa_maps_open(struct inode *inode, struct file *file)
615 {
616         struct task_struct *task = proc_task(inode);
617         int ret = seq_open(file, &proc_pid_numa_maps_op);
618         if (!ret) {
619                 struct seq_file *m = file->private_data;
620                 m->private = task;
621         }
622         return ret;
623 }
624
625 static struct file_operations proc_numa_maps_operations = {
626         .open           = numa_maps_open,
627         .read           = seq_read,
628         .llseek         = seq_lseek,
629         .release        = seq_release,
630 };
631 #endif
632
633 extern struct seq_operations proc_pid_smaps_op;
634 static int smaps_open(struct inode *inode, struct file *file)
635 {
636         struct task_struct *task = proc_task(inode);
637         int ret = seq_open(file, &proc_pid_smaps_op);
638         if (!ret) {
639                 struct seq_file *m = file->private_data;
640                 m->private = task;
641         }
642         return ret;
643 }
644
645 static struct file_operations proc_smaps_operations = {
646         .open           = smaps_open,
647         .read           = seq_read,
648         .llseek         = seq_lseek,
649         .release        = seq_release,
650 };
651
652 extern struct seq_operations mounts_op;
653 static int mounts_open(struct inode *inode, struct file *file)
654 {
655         struct task_struct *task = proc_task(inode);
656         int ret = seq_open(file, &mounts_op);
657
658         if (!ret) {
659                 struct seq_file *m = file->private_data;
660                 struct namespace *namespace;
661                 task_lock(task);
662                 namespace = task->namespace;
663                 if (namespace)
664                         get_namespace(namespace);
665                 task_unlock(task);
666
667                 if (namespace)
668                         m->private = namespace;
669                 else {
670                         seq_release(inode, file);
671                         ret = -EINVAL;
672                 }
673         }
674         return ret;
675 }
676
677 static int mounts_release(struct inode *inode, struct file *file)
678 {
679         struct seq_file *m = file->private_data;
680         struct namespace *namespace = m->private;
681         put_namespace(namespace);
682         return seq_release(inode, file);
683 }
684
685 static struct file_operations proc_mounts_operations = {
686         .open           = mounts_open,
687         .read           = seq_read,
688         .llseek         = seq_lseek,
689         .release        = mounts_release,
690 };
691
692 #define PROC_BLOCK_SIZE (3*1024)                /* 4K page size but our output routines use some slack for overruns */
693
694 static ssize_t proc_info_read(struct file * file, char __user * buf,
695                           size_t count, loff_t *ppos)
696 {
697         struct inode * inode = file->f_dentry->d_inode;
698         unsigned long page;
699         ssize_t length;
700         struct task_struct *task = proc_task(inode);
701
702         if (count > PROC_BLOCK_SIZE)
703                 count = PROC_BLOCK_SIZE;
704         if (!(page = __get_free_page(GFP_KERNEL)))
705                 return -ENOMEM;
706
707         length = PROC_I(inode)->op.proc_read(task, (char*)page);
708
709         if (length >= 0)
710                 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
711         free_page(page);
712         return length;
713 }
714
715 static struct file_operations proc_info_file_operations = {
716         .read           = proc_info_read,
717 };
718
719 static int mem_open(struct inode* inode, struct file* file)
720 {
721         file->private_data = (void*)((long)current->self_exec_id);
722         return 0;
723 }
724
725 static ssize_t mem_read(struct file * file, char __user * buf,
726                         size_t count, loff_t *ppos)
727 {
728         struct task_struct *task = proc_task(file->f_dentry->d_inode);
729         char *page;
730         unsigned long src = *ppos;
731         int ret = -ESRCH;
732         struct mm_struct *mm;
733
734         if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
735                 goto out;
736
737         ret = -ENOMEM;
738         page = (char *)__get_free_page(GFP_USER);
739         if (!page)
740                 goto out;
741
742         ret = 0;
743  
744         mm = get_task_mm(task);
745         if (!mm)
746                 goto out_free;
747
748         ret = -EIO;
749  
750         if (file->private_data != (void*)((long)current->self_exec_id))
751                 goto out_put;
752
753         ret = 0;
754  
755         while (count > 0) {
756                 int this_len, retval;
757
758                 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
759                 retval = access_process_vm(task, src, page, this_len, 0);
760                 if (!retval || !MAY_PTRACE(task) || !ptrace_may_attach(task)) {
761                         if (!ret)
762                                 ret = -EIO;
763                         break;
764                 }
765
766                 if (copy_to_user(buf, page, retval)) {
767                         ret = -EFAULT;
768                         break;
769                 }
770  
771                 ret += retval;
772                 src += retval;
773                 buf += retval;
774                 count -= retval;
775         }
776         *ppos = src;
777
778 out_put:
779         mmput(mm);
780 out_free:
781         free_page((unsigned long) page);
782 out:
783         return ret;
784 }
785
786 #define mem_write NULL
787
788 #ifndef mem_write
789 /* This is a security hazard */
790 static ssize_t mem_write(struct file * file, const char * buf,
791                          size_t count, loff_t *ppos)
792 {
793         int copied = 0;
794         char *page;
795         struct task_struct *task = proc_task(file->f_dentry->d_inode);
796         unsigned long dst = *ppos;
797
798         if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
799                 return -ESRCH;
800
801         page = (char *)__get_free_page(GFP_USER);
802         if (!page)
803                 return -ENOMEM;
804
805         while (count > 0) {
806                 int this_len, retval;
807
808                 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
809                 if (copy_from_user(page, buf, this_len)) {
810                         copied = -EFAULT;
811                         break;
812                 }
813                 retval = access_process_vm(task, dst, page, this_len, 1);
814                 if (!retval) {
815                         if (!copied)
816                                 copied = -EIO;
817                         break;
818                 }
819                 copied += retval;
820                 buf += retval;
821                 dst += retval;
822                 count -= retval;                        
823         }
824         *ppos = dst;
825         free_page((unsigned long) page);
826         return copied;
827 }
828 #endif
829
830 static loff_t mem_lseek(struct file * file, loff_t offset, int orig)
831 {
832         switch (orig) {
833         case 0:
834                 file->f_pos = offset;
835                 break;
836         case 1:
837                 file->f_pos += offset;
838                 break;
839         default:
840                 return -EINVAL;
841         }
842         force_successful_syscall_return();
843         return file->f_pos;
844 }
845
846 static struct file_operations proc_mem_operations = {
847         .llseek         = mem_lseek,
848         .read           = mem_read,
849         .write          = mem_write,
850         .open           = mem_open,
851 };
852
853 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
854                                 size_t count, loff_t *ppos)
855 {
856         struct task_struct *task = proc_task(file->f_dentry->d_inode);
857         char buffer[8];
858         size_t len;
859         int oom_adjust = task->oomkilladj;
860         loff_t __ppos = *ppos;
861
862         len = sprintf(buffer, "%i\n", oom_adjust);
863         if (__ppos >= len)
864                 return 0;
865         if (count > len-__ppos)
866                 count = len-__ppos;
867         if (copy_to_user(buf, buffer + __ppos, count))
868                 return -EFAULT;
869         *ppos = __ppos + count;
870         return count;
871 }
872
873 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
874                                 size_t count, loff_t *ppos)
875 {
876         struct task_struct *task = proc_task(file->f_dentry->d_inode);
877         char buffer[8], *end;
878         int oom_adjust;
879
880         if (!capable(CAP_SYS_RESOURCE))
881                 return -EPERM;
882         memset(buffer, 0, 8);
883         if (count > 6)
884                 count = 6;
885         if (copy_from_user(buffer, buf, count))
886                 return -EFAULT;
887         oom_adjust = simple_strtol(buffer, &end, 0);
888         if ((oom_adjust < -16 || oom_adjust > 15) && oom_adjust != OOM_DISABLE)
889                 return -EINVAL;
890         if (*end == '\n')
891                 end++;
892         task->oomkilladj = oom_adjust;
893         if (end - buffer == 0)
894                 return -EIO;
895         return end - buffer;
896 }
897
898 static struct file_operations proc_oom_adjust_operations = {
899         .read           = oom_adjust_read,
900         .write          = oom_adjust_write,
901 };
902
903 static struct inode_operations proc_mem_inode_operations = {
904         .permission     = proc_permission,
905 };
906
907 #ifdef CONFIG_AUDITSYSCALL
908 #define TMPBUFLEN 21
909 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
910                                   size_t count, loff_t *ppos)
911 {
912         struct inode * inode = file->f_dentry->d_inode;
913         struct task_struct *task = proc_task(inode);
914         ssize_t length;
915         char tmpbuf[TMPBUFLEN];
916
917         length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
918                                 audit_get_loginuid(task->audit_context));
919         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
920 }
921
922 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
923                                    size_t count, loff_t *ppos)
924 {
925         struct inode * inode = file->f_dentry->d_inode;
926         char *page, *tmp;
927         ssize_t length;
928         struct task_struct *task = proc_task(inode);
929         uid_t loginuid;
930
931         if (!capable(CAP_AUDIT_CONTROL))
932                 return -EPERM;
933
934         if (current != task)
935                 return -EPERM;
936
937         if (count > PAGE_SIZE)
938                 count = PAGE_SIZE;
939
940         if (*ppos != 0) {
941                 /* No partial writes. */
942                 return -EINVAL;
943         }
944         page = (char*)__get_free_page(GFP_USER);
945         if (!page)
946                 return -ENOMEM;
947         length = -EFAULT;
948         if (copy_from_user(page, buf, count))
949                 goto out_free_page;
950
951         loginuid = simple_strtoul(page, &tmp, 10);
952         if (tmp == page) {
953                 length = -EINVAL;
954                 goto out_free_page;
955
956         }
957         length = audit_set_loginuid(task, loginuid);
958         if (likely(length == 0))
959                 length = count;
960
961 out_free_page:
962         free_page((unsigned long) page);
963         return length;
964 }
965
966 static struct file_operations proc_loginuid_operations = {
967         .read           = proc_loginuid_read,
968         .write          = proc_loginuid_write,
969 };
970 #endif
971
972 #ifdef CONFIG_SECCOMP
973 static ssize_t seccomp_read(struct file *file, char __user *buf,
974                             size_t count, loff_t *ppos)
975 {
976         struct task_struct *tsk = proc_task(file->f_dentry->d_inode);
977         char __buf[20];
978         loff_t __ppos = *ppos;
979         size_t len;
980
981         /* no need to print the trailing zero, so use only len */
982         len = sprintf(__buf, "%u\n", tsk->seccomp.mode);
983         if (__ppos >= len)
984                 return 0;
985         if (count > len - __ppos)
986                 count = len - __ppos;
987         if (copy_to_user(buf, __buf + __ppos, count))
988                 return -EFAULT;
989         *ppos = __ppos + count;
990         return count;
991 }
992
993 static ssize_t seccomp_write(struct file *file, const char __user *buf,
994                              size_t count, loff_t *ppos)
995 {
996         struct task_struct *tsk = proc_task(file->f_dentry->d_inode);
997         char __buf[20], *end;
998         unsigned int seccomp_mode;
999
1000         /* can set it only once to be even more secure */
1001         if (unlikely(tsk->seccomp.mode))
1002                 return -EPERM;
1003
1004         memset(__buf, 0, sizeof(__buf));
1005         count = min(count, sizeof(__buf) - 1);
1006         if (copy_from_user(__buf, buf, count))
1007                 return -EFAULT;
1008         seccomp_mode = simple_strtoul(__buf, &end, 0);
1009         if (*end == '\n')
1010                 end++;
1011         if (seccomp_mode && seccomp_mode <= NR_SECCOMP_MODES) {
1012                 tsk->seccomp.mode = seccomp_mode;
1013                 set_tsk_thread_flag(tsk, TIF_SECCOMP);
1014         } else
1015                 return -EINVAL;
1016         if (unlikely(!(end - __buf)))
1017                 return -EIO;
1018         return end - __buf;
1019 }
1020
1021 static struct file_operations proc_seccomp_operations = {
1022         .read           = seccomp_read,
1023         .write          = seccomp_write,
1024 };
1025 #endif /* CONFIG_SECCOMP */
1026
1027 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1028 {
1029         struct inode *inode = dentry->d_inode;
1030         int error = -EACCES;
1031
1032         /* We don't need a base pointer in the /proc filesystem */
1033         path_release(nd);
1034
1035         if (current->fsuid != inode->i_uid && !capable(CAP_DAC_OVERRIDE))
1036                 goto out;
1037         error = proc_check_root(inode);
1038         if (error)
1039                 goto out;
1040
1041         error = PROC_I(inode)->op.proc_get_link(inode, &nd->dentry, &nd->mnt);
1042         nd->last_type = LAST_BIND;
1043 out:
1044         return ERR_PTR(error);
1045 }
1046
1047 static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt,
1048                             char __user *buffer, int buflen)
1049 {
1050         struct inode * inode;
1051         char *tmp = (char*)__get_free_page(GFP_KERNEL), *path;
1052         int len;
1053
1054         if (!tmp)
1055                 return -ENOMEM;
1056                 
1057         inode = dentry->d_inode;
1058         path = d_path(dentry, mnt, tmp, PAGE_SIZE);
1059         len = PTR_ERR(path);
1060         if (IS_ERR(path))
1061                 goto out;
1062         len = tmp + PAGE_SIZE - 1 - path;
1063
1064         if (len > buflen)
1065                 len = buflen;
1066         if (copy_to_user(buffer, path, len))
1067                 len = -EFAULT;
1068  out:
1069         free_page((unsigned long)tmp);
1070         return len;
1071 }
1072
1073 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1074 {
1075         int error = -EACCES;
1076         struct inode *inode = dentry->d_inode;
1077         struct dentry *de;
1078         struct vfsmount *mnt = NULL;
1079
1080         lock_kernel();
1081
1082         if (current->fsuid != inode->i_uid && !capable(CAP_DAC_OVERRIDE))
1083                 goto out;
1084         error = proc_check_root(inode);
1085         if (error)
1086                 goto out;
1087
1088         error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt);
1089         if (error)
1090                 goto out;
1091
1092         error = do_proc_readlink(de, mnt, buffer, buflen);
1093         dput(de);
1094         mntput(mnt);
1095 out:
1096         unlock_kernel();
1097         return error;
1098 }
1099
1100 static struct inode_operations proc_pid_link_inode_operations = {
1101         .readlink       = proc_pid_readlink,
1102         .follow_link    = proc_pid_follow_link
1103 };
1104
1105 #define NUMBUF 10
1106
1107 static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
1108 {
1109         struct inode *inode = filp->f_dentry->d_inode;
1110         struct task_struct *p = proc_task(inode);
1111         unsigned int fd, tid, ino;
1112         int retval;
1113         char buf[NUMBUF];
1114         struct files_struct * files;
1115         struct fdtable *fdt;
1116
1117         retval = -ENOENT;
1118         if (!pid_alive(p))
1119                 goto out;
1120         retval = 0;
1121         tid = p->pid;
1122
1123         fd = filp->f_pos;
1124         switch (fd) {
1125                 case 0:
1126                         if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1127                                 goto out;
1128                         filp->f_pos++;
1129                 case 1:
1130                         ino = fake_ino(tid, PROC_TID_INO);
1131                         if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1132                                 goto out;
1133                         filp->f_pos++;
1134                 default:
1135                         files = get_files_struct(p);
1136                         if (!files)
1137                                 goto out;
1138                         rcu_read_lock();
1139                         fdt = files_fdtable(files);
1140                         for (fd = filp->f_pos-2;
1141                              fd < fdt->max_fds;
1142                              fd++, filp->f_pos++) {
1143                                 unsigned int i,j;
1144
1145                                 if (!fcheck_files(files, fd))
1146                                         continue;
1147                                 rcu_read_unlock();
1148
1149                                 j = NUMBUF;
1150                                 i = fd;
1151                                 do {
1152                                         j--;
1153                                         buf[j] = '0' + (i % 10);
1154                                         i /= 10;
1155                                 } while (i);
1156
1157                                 ino = fake_ino(tid, PROC_TID_FD_DIR + fd);
1158                                 if (filldir(dirent, buf+j, NUMBUF-j, fd+2, ino, DT_LNK) < 0) {
1159                                         rcu_read_lock();
1160                                         break;
1161                                 }
1162                                 rcu_read_lock();
1163                         }
1164                         rcu_read_unlock();
1165                         put_files_struct(files);
1166         }
1167 out:
1168         return retval;
1169 }
1170
1171 static int proc_pident_readdir(struct file *filp,
1172                 void *dirent, filldir_t filldir,
1173                 struct pid_entry *ents, unsigned int nents)
1174 {
1175         int i;
1176         int pid;
1177         struct dentry *dentry = filp->f_dentry;
1178         struct inode *inode = dentry->d_inode;
1179         struct pid_entry *p;
1180         ino_t ino;
1181         int ret;
1182
1183         ret = -ENOENT;
1184         if (!pid_alive(proc_task(inode)))
1185                 goto out;
1186
1187         ret = 0;
1188         pid = proc_task(inode)->pid;
1189         i = filp->f_pos;
1190         switch (i) {
1191         case 0:
1192                 ino = inode->i_ino;
1193                 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
1194                         goto out;
1195                 i++;
1196                 filp->f_pos++;
1197                 /* fall through */
1198         case 1:
1199                 ino = parent_ino(dentry);
1200                 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
1201                         goto out;
1202                 i++;
1203                 filp->f_pos++;
1204                 /* fall through */
1205         default:
1206                 i -= 2;
1207                 if (i >= nents) {
1208                         ret = 1;
1209                         goto out;
1210                 }
1211                 p = ents + i;
1212                 while (p->name) {
1213                         if (filldir(dirent, p->name, p->len, filp->f_pos,
1214                                     fake_ino(pid, p->type), p->mode >> 12) < 0)
1215                                 goto out;
1216                         filp->f_pos++;
1217                         p++;
1218                 }
1219         }
1220
1221         ret = 1;
1222 out:
1223         return ret;
1224 }
1225
1226 static int proc_tgid_base_readdir(struct file * filp,
1227                              void * dirent, filldir_t filldir)
1228 {
1229         return proc_pident_readdir(filp,dirent,filldir,
1230                                    tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
1231 }
1232
1233 static int proc_tid_base_readdir(struct file * filp,
1234                              void * dirent, filldir_t filldir)
1235 {
1236         return proc_pident_readdir(filp,dirent,filldir,
1237                                    tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
1238 }
1239
1240 /* building an inode */
1241
1242 static int task_dumpable(struct task_struct *task)
1243 {
1244         int dumpable = 0;
1245         struct mm_struct *mm;
1246
1247         task_lock(task);
1248         mm = task->mm;
1249         if (mm)
1250                 dumpable = mm->dumpable;
1251         task_unlock(task);
1252         if(dumpable == 1)
1253                 return 1;
1254         return 0;
1255 }
1256
1257
1258 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task, int ino)
1259 {
1260         struct inode * inode;
1261         struct proc_inode *ei;
1262
1263         /* We need a new inode */
1264         
1265         inode = new_inode(sb);
1266         if (!inode)
1267                 goto out;
1268
1269         /* Common stuff */
1270         ei = PROC_I(inode);
1271         ei->task = NULL;
1272         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1273         inode->i_ino = fake_ino(task->pid, ino);
1274
1275         if (!pid_alive(task))
1276                 goto out_unlock;
1277
1278         /*
1279          * grab the reference to task.
1280          */
1281         get_task_struct(task);
1282         ei->task = task;
1283         ei->type = ino;
1284         inode->i_uid = 0;
1285         inode->i_gid = 0;
1286         if (ino == PROC_TGID_INO || ino == PROC_TID_INO || task_dumpable(task)) {
1287                 inode->i_uid = task->euid;
1288                 inode->i_gid = task->egid;
1289         }
1290         security_task_to_inode(task, inode);
1291
1292 out:
1293         return inode;
1294
1295 out_unlock:
1296         ei->pde = NULL;
1297         iput(inode);
1298         return NULL;
1299 }
1300
1301 /* dentry stuff */
1302
1303 /*
1304  *      Exceptional case: normally we are not allowed to unhash a busy
1305  * directory. In this case, however, we can do it - no aliasing problems
1306  * due to the way we treat inodes.
1307  *
1308  * Rewrite the inode's ownerships here because the owning task may have
1309  * performed a setuid(), etc.
1310  */
1311 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1312 {
1313         struct inode *inode = dentry->d_inode;
1314         struct task_struct *task = proc_task(inode);
1315         if (pid_alive(task)) {
1316                 if (proc_type(inode) == PROC_TGID_INO || proc_type(inode) == PROC_TID_INO || task_dumpable(task)) {
1317                         inode->i_uid = task->euid;
1318                         inode->i_gid = task->egid;
1319                 } else {
1320                         inode->i_uid = 0;
1321                         inode->i_gid = 0;
1322                 }
1323                 security_task_to_inode(task, inode);
1324                 return 1;
1325         }
1326         d_drop(dentry);
1327         return 0;
1328 }
1329
1330 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1331 {
1332         struct inode *inode = dentry->d_inode;
1333         struct task_struct *task = proc_task(inode);
1334         int fd = proc_type(inode) - PROC_TID_FD_DIR;
1335         struct files_struct *files;
1336
1337         files = get_files_struct(task);
1338         if (files) {
1339                 rcu_read_lock();
1340                 if (fcheck_files(files, fd)) {
1341                         rcu_read_unlock();
1342                         put_files_struct(files);
1343                         if (task_dumpable(task)) {
1344                                 inode->i_uid = task->euid;
1345                                 inode->i_gid = task->egid;
1346                         } else {
1347                                 inode->i_uid = 0;
1348                                 inode->i_gid = 0;
1349                         }
1350                         security_task_to_inode(task, inode);
1351                         return 1;
1352                 }
1353                 rcu_read_unlock();
1354                 put_files_struct(files);
1355         }
1356         d_drop(dentry);
1357         return 0;
1358 }
1359
1360 static void pid_base_iput(struct dentry *dentry, struct inode *inode)
1361 {
1362         struct task_struct *task = proc_task(inode);
1363         spin_lock(&task->proc_lock);
1364         if (task->proc_dentry == dentry)
1365                 task->proc_dentry = NULL;
1366         spin_unlock(&task->proc_lock);
1367         iput(inode);
1368 }
1369
1370 static int pid_delete_dentry(struct dentry * dentry)
1371 {
1372         /* Is the task we represent dead?
1373          * If so, then don't put the dentry on the lru list,
1374          * kill it immediately.
1375          */
1376         return !pid_alive(proc_task(dentry->d_inode));
1377 }
1378
1379 static struct dentry_operations tid_fd_dentry_operations =
1380 {
1381         .d_revalidate   = tid_fd_revalidate,
1382         .d_delete       = pid_delete_dentry,
1383 };
1384
1385 static struct dentry_operations pid_dentry_operations =
1386 {
1387         .d_revalidate   = pid_revalidate,
1388         .d_delete       = pid_delete_dentry,
1389 };
1390
1391 static struct dentry_operations pid_base_dentry_operations =
1392 {
1393         .d_revalidate   = pid_revalidate,
1394         .d_iput         = pid_base_iput,
1395         .d_delete       = pid_delete_dentry,
1396 };
1397
1398 /* Lookups */
1399
1400 static unsigned name_to_int(struct dentry *dentry)
1401 {
1402         const char *name = dentry->d_name.name;
1403         int len = dentry->d_name.len;
1404         unsigned n = 0;
1405
1406         if (len > 1 && *name == '0')
1407                 goto out;
1408         while (len-- > 0) {
1409                 unsigned c = *name++ - '0';
1410                 if (c > 9)
1411                         goto out;
1412                 if (n >= (~0U-9)/10)
1413                         goto out;
1414                 n *= 10;
1415                 n += c;
1416         }
1417         return n;
1418 out:
1419         return ~0U;
1420 }
1421
1422 /* SMP-safe */
1423 static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
1424 {
1425         struct task_struct *task = proc_task(dir);
1426         unsigned fd = name_to_int(dentry);
1427         struct file * file;
1428         struct files_struct * files;
1429         struct inode *inode;
1430         struct proc_inode *ei;
1431
1432         if (fd == ~0U)
1433                 goto out;
1434         if (!pid_alive(task))
1435                 goto out;
1436
1437         inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_FD_DIR+fd);
1438         if (!inode)
1439                 goto out;
1440         ei = PROC_I(inode);
1441         files = get_files_struct(task);
1442         if (!files)
1443                 goto out_unlock;
1444         inode->i_mode = S_IFLNK;
1445         rcu_read_lock();
1446         file = fcheck_files(files, fd);
1447         if (!file)
1448                 goto out_unlock2;
1449         if (file->f_mode & 1)
1450                 inode->i_mode |= S_IRUSR | S_IXUSR;
1451         if (file->f_mode & 2)
1452                 inode->i_mode |= S_IWUSR | S_IXUSR;
1453         rcu_read_unlock();
1454         put_files_struct(files);
1455         inode->i_op = &proc_pid_link_inode_operations;
1456         inode->i_size = 64;
1457         ei->op.proc_get_link = proc_fd_link;
1458         dentry->d_op = &tid_fd_dentry_operations;
1459         d_add(dentry, inode);
1460         return NULL;
1461
1462 out_unlock2:
1463         rcu_read_unlock();
1464         put_files_struct(files);
1465 out_unlock:
1466         iput(inode);
1467 out:
1468         return ERR_PTR(-ENOENT);
1469 }
1470
1471 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir);
1472 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd);
1473
1474 static struct file_operations proc_fd_operations = {
1475         .read           = generic_read_dir,
1476         .readdir        = proc_readfd,
1477 };
1478
1479 static struct file_operations proc_task_operations = {
1480         .read           = generic_read_dir,
1481         .readdir        = proc_task_readdir,
1482 };
1483
1484 /*
1485  * proc directories can do almost nothing..
1486  */
1487 static struct inode_operations proc_fd_inode_operations = {
1488         .lookup         = proc_lookupfd,
1489         .permission     = proc_permission,
1490 };
1491
1492 static struct inode_operations proc_task_inode_operations = {
1493         .lookup         = proc_task_lookup,
1494         .permission     = proc_task_permission,
1495 };
1496
1497 #ifdef CONFIG_SECURITY
1498 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
1499                                   size_t count, loff_t *ppos)
1500 {
1501         struct inode * inode = file->f_dentry->d_inode;
1502         unsigned long page;
1503         ssize_t length;
1504         struct task_struct *task = proc_task(inode);
1505
1506         if (count > PAGE_SIZE)
1507                 count = PAGE_SIZE;
1508         if (!(page = __get_free_page(GFP_KERNEL)))
1509                 return -ENOMEM;
1510
1511         length = security_getprocattr(task, 
1512                                       (char*)file->f_dentry->d_name.name, 
1513                                       (void*)page, count);
1514         if (length >= 0)
1515                 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
1516         free_page(page);
1517         return length;
1518 }
1519
1520 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
1521                                    size_t count, loff_t *ppos)
1522
1523         struct inode * inode = file->f_dentry->d_inode;
1524         char *page; 
1525         ssize_t length; 
1526         struct task_struct *task = proc_task(inode); 
1527
1528         if (count > PAGE_SIZE) 
1529                 count = PAGE_SIZE; 
1530         if (*ppos != 0) {
1531                 /* No partial writes. */
1532                 return -EINVAL;
1533         }
1534         page = (char*)__get_free_page(GFP_USER); 
1535         if (!page) 
1536                 return -ENOMEM;
1537         length = -EFAULT; 
1538         if (copy_from_user(page, buf, count)) 
1539                 goto out;
1540
1541         length = security_setprocattr(task, 
1542                                       (char*)file->f_dentry->d_name.name, 
1543                                       (void*)page, count);
1544 out:
1545         free_page((unsigned long) page);
1546         return length;
1547
1548
1549 static struct file_operations proc_pid_attr_operations = {
1550         .read           = proc_pid_attr_read,
1551         .write          = proc_pid_attr_write,
1552 };
1553
1554 static struct file_operations proc_tid_attr_operations;
1555 static struct inode_operations proc_tid_attr_inode_operations;
1556 static struct file_operations proc_tgid_attr_operations;
1557 static struct inode_operations proc_tgid_attr_inode_operations;
1558 #endif
1559
1560 static int get_tid_list(int index, unsigned int *tids, struct inode *dir);
1561
1562 /* SMP-safe */
1563 static struct dentry *proc_pident_lookup(struct inode *dir, 
1564                                          struct dentry *dentry,
1565                                          struct pid_entry *ents)
1566 {
1567         struct inode *inode;
1568         int error;
1569         struct task_struct *task = proc_task(dir);
1570         struct pid_entry *p;
1571         struct proc_inode *ei;
1572
1573         error = -ENOENT;
1574         inode = NULL;
1575
1576         if (!pid_alive(task))
1577                 goto out;
1578
1579         for (p = ents; p->name; p++) {
1580                 if (p->len != dentry->d_name.len)
1581                         continue;
1582                 if (!memcmp(dentry->d_name.name, p->name, p->len))
1583                         break;
1584         }
1585         if (!p->name)
1586                 goto out;
1587
1588         error = -EINVAL;
1589         inode = proc_pid_make_inode(dir->i_sb, task, p->type);
1590         if (!inode)
1591                 goto out;
1592
1593         ei = PROC_I(inode);
1594         inode->i_mode = p->mode;
1595         /*
1596          * Yes, it does not scale. And it should not. Don't add
1597          * new entries into /proc/<tgid>/ without very good reasons.
1598          */
1599         switch(p->type) {
1600                 case PROC_TGID_TASK:
1601                         inode->i_nlink = 2 + get_tid_list(2, NULL, dir);
1602                         inode->i_op = &proc_task_inode_operations;
1603                         inode->i_fop = &proc_task_operations;
1604                         break;
1605                 case PROC_TID_FD:
1606                 case PROC_TGID_FD:
1607                         inode->i_nlink = 2;
1608                         inode->i_op = &proc_fd_inode_operations;
1609                         inode->i_fop = &proc_fd_operations;
1610                         break;
1611                 case PROC_TID_EXE:
1612                 case PROC_TGID_EXE:
1613                         inode->i_op = &proc_pid_link_inode_operations;
1614                         ei->op.proc_get_link = proc_exe_link;
1615                         break;
1616                 case PROC_TID_CWD:
1617                 case PROC_TGID_CWD:
1618                         inode->i_op = &proc_pid_link_inode_operations;
1619                         ei->op.proc_get_link = proc_cwd_link;
1620                         break;
1621                 case PROC_TID_ROOT:
1622                 case PROC_TGID_ROOT:
1623                         inode->i_op = &proc_pid_link_inode_operations;
1624                         ei->op.proc_get_link = proc_root_link;
1625                         break;
1626                 case PROC_TID_ENVIRON:
1627                 case PROC_TGID_ENVIRON:
1628                         inode->i_fop = &proc_info_file_operations;
1629                         ei->op.proc_read = proc_pid_environ;
1630                         break;
1631                 case PROC_TID_AUXV:
1632                 case PROC_TGID_AUXV:
1633                         inode->i_fop = &proc_info_file_operations;
1634                         ei->op.proc_read = proc_pid_auxv;
1635                         break;
1636                 case PROC_TID_STATUS:
1637                 case PROC_TGID_STATUS:
1638                         inode->i_fop = &proc_info_file_operations;
1639                         ei->op.proc_read = proc_pid_status;
1640                         break;
1641                 case PROC_TID_STAT:
1642                         inode->i_fop = &proc_info_file_operations;
1643                         ei->op.proc_read = proc_tid_stat;
1644                         break;
1645                 case PROC_TGID_STAT:
1646                         inode->i_fop = &proc_info_file_operations;
1647                         ei->op.proc_read = proc_tgid_stat;
1648                         break;
1649                 case PROC_TID_CMDLINE:
1650                 case PROC_TGID_CMDLINE:
1651                         inode->i_fop = &proc_info_file_operations;
1652                         ei->op.proc_read = proc_pid_cmdline;
1653                         break;
1654                 case PROC_TID_STATM:
1655                 case PROC_TGID_STATM:
1656                         inode->i_fop = &proc_info_file_operations;
1657                         ei->op.proc_read = proc_pid_statm;
1658                         break;
1659                 case PROC_TID_MAPS:
1660                 case PROC_TGID_MAPS:
1661                         inode->i_fop = &proc_maps_operations;
1662                         break;
1663 #ifdef CONFIG_NUMA
1664                 case PROC_TID_NUMA_MAPS:
1665                 case PROC_TGID_NUMA_MAPS:
1666                         inode->i_fop = &proc_numa_maps_operations;
1667                         break;
1668 #endif
1669                 case PROC_TID_MEM:
1670                 case PROC_TGID_MEM:
1671                         inode->i_op = &proc_mem_inode_operations;
1672                         inode->i_fop = &proc_mem_operations;
1673                         break;
1674 #ifdef CONFIG_SECCOMP
1675                 case PROC_TID_SECCOMP:
1676                 case PROC_TGID_SECCOMP:
1677                         inode->i_fop = &proc_seccomp_operations;
1678                         break;
1679 #endif /* CONFIG_SECCOMP */
1680                 case PROC_TID_MOUNTS:
1681                 case PROC_TGID_MOUNTS:
1682                         inode->i_fop = &proc_mounts_operations;
1683                         break;
1684                 case PROC_TID_SMAPS:
1685                 case PROC_TGID_SMAPS:
1686                         inode->i_fop = &proc_smaps_operations;
1687                         break;
1688 #ifdef CONFIG_SECURITY
1689                 case PROC_TID_ATTR:
1690                         inode->i_nlink = 2;
1691                         inode->i_op = &proc_tid_attr_inode_operations;
1692                         inode->i_fop = &proc_tid_attr_operations;
1693                         break;
1694                 case PROC_TGID_ATTR:
1695                         inode->i_nlink = 2;
1696                         inode->i_op = &proc_tgid_attr_inode_operations;
1697                         inode->i_fop = &proc_tgid_attr_operations;
1698                         break;
1699                 case PROC_TID_ATTR_CURRENT:
1700                 case PROC_TGID_ATTR_CURRENT:
1701                 case PROC_TID_ATTR_PREV:
1702                 case PROC_TGID_ATTR_PREV:
1703                 case PROC_TID_ATTR_EXEC:
1704                 case PROC_TGID_ATTR_EXEC:
1705                 case PROC_TID_ATTR_FSCREATE:
1706                 case PROC_TGID_ATTR_FSCREATE:
1707                         inode->i_fop = &proc_pid_attr_operations;
1708                         break;
1709 #endif
1710 #ifdef CONFIG_KALLSYMS
1711                 case PROC_TID_WCHAN:
1712                 case PROC_TGID_WCHAN:
1713                         inode->i_fop = &proc_info_file_operations;
1714                         ei->op.proc_read = proc_pid_wchan;
1715                         break;
1716 #endif
1717 #ifdef CONFIG_SCHEDSTATS
1718                 case PROC_TID_SCHEDSTAT:
1719                 case PROC_TGID_SCHEDSTAT:
1720                         inode->i_fop = &proc_info_file_operations;
1721                         ei->op.proc_read = proc_pid_schedstat;
1722                         break;
1723 #endif
1724 #ifdef CONFIG_CPUSETS
1725                 case PROC_TID_CPUSET:
1726                 case PROC_TGID_CPUSET:
1727                         inode->i_fop = &proc_cpuset_operations;
1728                         break;
1729 #endif
1730                 case PROC_TID_OOM_SCORE:
1731                 case PROC_TGID_OOM_SCORE:
1732                         inode->i_fop = &proc_info_file_operations;
1733                         ei->op.proc_read = proc_oom_score;
1734                         break;
1735                 case PROC_TID_OOM_ADJUST:
1736                 case PROC_TGID_OOM_ADJUST:
1737                         inode->i_fop = &proc_oom_adjust_operations;
1738                         break;
1739 #ifdef CONFIG_AUDITSYSCALL
1740                 case PROC_TID_LOGINUID:
1741                 case PROC_TGID_LOGINUID:
1742                         inode->i_fop = &proc_loginuid_operations;
1743                         break;
1744 #endif
1745                 default:
1746                         printk("procfs: impossible type (%d)",p->type);
1747                         iput(inode);
1748                         return ERR_PTR(-EINVAL);
1749         }
1750         dentry->d_op = &pid_dentry_operations;
1751         d_add(dentry, inode);
1752         return NULL;
1753
1754 out:
1755         return ERR_PTR(error);
1756 }
1757
1758 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
1759         return proc_pident_lookup(dir, dentry, tgid_base_stuff);
1760 }
1761
1762 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
1763         return proc_pident_lookup(dir, dentry, tid_base_stuff);
1764 }
1765
1766 static struct file_operations proc_tgid_base_operations = {
1767         .read           = generic_read_dir,
1768         .readdir        = proc_tgid_base_readdir,
1769 };
1770
1771 static struct file_operations proc_tid_base_operations = {
1772         .read           = generic_read_dir,
1773         .readdir        = proc_tid_base_readdir,
1774 };
1775
1776 static struct inode_operations proc_tgid_base_inode_operations = {
1777         .lookup         = proc_tgid_base_lookup,
1778 };
1779
1780 static struct inode_operations proc_tid_base_inode_operations = {
1781         .lookup         = proc_tid_base_lookup,
1782 };
1783
1784 #ifdef CONFIG_SECURITY
1785 static int proc_tgid_attr_readdir(struct file * filp,
1786                              void * dirent, filldir_t filldir)
1787 {
1788         return proc_pident_readdir(filp,dirent,filldir,
1789                                    tgid_attr_stuff,ARRAY_SIZE(tgid_attr_stuff));
1790 }
1791
1792 static int proc_tid_attr_readdir(struct file * filp,
1793                              void * dirent, filldir_t filldir)
1794 {
1795         return proc_pident_readdir(filp,dirent,filldir,
1796                                    tid_attr_stuff,ARRAY_SIZE(tid_attr_stuff));
1797 }
1798
1799 static struct file_operations proc_tgid_attr_operations = {
1800         .read           = generic_read_dir,
1801         .readdir        = proc_tgid_attr_readdir,
1802 };
1803
1804 static struct file_operations proc_tid_attr_operations = {
1805         .read           = generic_read_dir,
1806         .readdir        = proc_tid_attr_readdir,
1807 };
1808
1809 static struct dentry *proc_tgid_attr_lookup(struct inode *dir,
1810                                 struct dentry *dentry, struct nameidata *nd)
1811 {
1812         return proc_pident_lookup(dir, dentry, tgid_attr_stuff);
1813 }
1814
1815 static struct dentry *proc_tid_attr_lookup(struct inode *dir,
1816                                 struct dentry *dentry, struct nameidata *nd)
1817 {
1818         return proc_pident_lookup(dir, dentry, tid_attr_stuff);
1819 }
1820
1821 static struct inode_operations proc_tgid_attr_inode_operations = {
1822         .lookup         = proc_tgid_attr_lookup,
1823 };
1824
1825 static struct inode_operations proc_tid_attr_inode_operations = {
1826         .lookup         = proc_tid_attr_lookup,
1827 };
1828 #endif
1829
1830 /*
1831  * /proc/self:
1832  */
1833 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
1834                               int buflen)
1835 {
1836         char tmp[30];
1837         sprintf(tmp, "%d", current->tgid);
1838         return vfs_readlink(dentry,buffer,buflen,tmp);
1839 }
1840
1841 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
1842 {
1843         char tmp[30];
1844         sprintf(tmp, "%d", current->tgid);
1845         return ERR_PTR(vfs_follow_link(nd,tmp));
1846 }       
1847
1848 static struct inode_operations proc_self_inode_operations = {
1849         .readlink       = proc_self_readlink,
1850         .follow_link    = proc_self_follow_link,
1851 };
1852
1853 /**
1854  * proc_pid_unhash -  Unhash /proc/@pid entry from the dcache.
1855  * @p: task that should be flushed.
1856  *
1857  * Drops the /proc/@pid dcache entry from the hash chains.
1858  *
1859  * Dropping /proc/@pid entries and detach_pid must be synchroneous,
1860  * otherwise e.g. /proc/@pid/exe might point to the wrong executable,
1861  * if the pid value is immediately reused. This is enforced by
1862  * - caller must acquire spin_lock(p->proc_lock)
1863  * - must be called before detach_pid()
1864  * - proc_pid_lookup acquires proc_lock, and checks that
1865  *   the target is not dead by looking at the attach count
1866  *   of PIDTYPE_PID.
1867  */
1868
1869 struct dentry *proc_pid_unhash(struct task_struct *p)
1870 {
1871         struct dentry *proc_dentry;
1872
1873         proc_dentry = p->proc_dentry;
1874         if (proc_dentry != NULL) {
1875
1876                 spin_lock(&dcache_lock);
1877                 spin_lock(&proc_dentry->d_lock);
1878                 if (!d_unhashed(proc_dentry)) {
1879                         dget_locked(proc_dentry);
1880                         __d_drop(proc_dentry);
1881                         spin_unlock(&proc_dentry->d_lock);
1882                 } else {
1883                         spin_unlock(&proc_dentry->d_lock);
1884                         proc_dentry = NULL;
1885                 }
1886                 spin_unlock(&dcache_lock);
1887         }
1888         return proc_dentry;
1889 }
1890
1891 /**
1892  * proc_pid_flush - recover memory used by stale /proc/@pid/x entries
1893  * @proc_dentry: directoy to prune.
1894  *
1895  * Shrink the /proc directory that was used by the just killed thread.
1896  */
1897         
1898 void proc_pid_flush(struct dentry *proc_dentry)
1899 {
1900         might_sleep();
1901         if(proc_dentry != NULL) {
1902                 shrink_dcache_parent(proc_dentry);
1903                 dput(proc_dentry);
1904         }
1905 }
1906
1907 /* SMP-safe */
1908 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
1909 {
1910         struct task_struct *task;
1911         struct inode *inode;
1912         struct proc_inode *ei;
1913         unsigned tgid;
1914         int died;
1915
1916         if (dentry->d_name.len == 4 && !memcmp(dentry->d_name.name,"self",4)) {
1917                 inode = new_inode(dir->i_sb);
1918                 if (!inode)
1919                         return ERR_PTR(-ENOMEM);
1920                 ei = PROC_I(inode);
1921                 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1922                 inode->i_ino = fake_ino(0, PROC_TGID_INO);
1923                 ei->pde = NULL;
1924                 inode->i_mode = S_IFLNK|S_IRWXUGO;
1925                 inode->i_uid = inode->i_gid = 0;
1926                 inode->i_size = 64;
1927                 inode->i_op = &proc_self_inode_operations;
1928                 d_add(dentry, inode);
1929                 return NULL;
1930         }
1931         tgid = name_to_int(dentry);
1932         if (tgid == ~0U)
1933                 goto out;
1934
1935         read_lock(&tasklist_lock);
1936         task = find_task_by_pid(tgid);
1937         if (task)
1938                 get_task_struct(task);
1939         read_unlock(&tasklist_lock);
1940         if (!task)
1941                 goto out;
1942
1943         inode = proc_pid_make_inode(dir->i_sb, task, PROC_TGID_INO);
1944
1945
1946         if (!inode) {
1947                 put_task_struct(task);
1948                 goto out;
1949         }
1950         inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
1951         inode->i_op = &proc_tgid_base_inode_operations;
1952         inode->i_fop = &proc_tgid_base_operations;
1953         inode->i_flags|=S_IMMUTABLE;
1954 #ifdef CONFIG_SECURITY
1955         inode->i_nlink = 5;
1956 #else
1957         inode->i_nlink = 4;
1958 #endif
1959
1960         dentry->d_op = &pid_base_dentry_operations;
1961
1962         died = 0;
1963         d_add(dentry, inode);
1964         spin_lock(&task->proc_lock);
1965         task->proc_dentry = dentry;
1966         if (!pid_alive(task)) {
1967                 dentry = proc_pid_unhash(task);
1968                 died = 1;
1969         }
1970         spin_unlock(&task->proc_lock);
1971
1972         put_task_struct(task);
1973         if (died) {
1974                 proc_pid_flush(dentry);
1975                 goto out;
1976         }
1977         return NULL;
1978 out:
1979         return ERR_PTR(-ENOENT);
1980 }
1981
1982 /* SMP-safe */
1983 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
1984 {
1985         struct task_struct *task;
1986         struct task_struct *leader = proc_task(dir);
1987         struct inode *inode;
1988         unsigned tid;
1989
1990         tid = name_to_int(dentry);
1991         if (tid == ~0U)
1992                 goto out;
1993
1994         read_lock(&tasklist_lock);
1995         task = find_task_by_pid(tid);
1996         if (task)
1997                 get_task_struct(task);
1998         read_unlock(&tasklist_lock);
1999         if (!task)
2000                 goto out;
2001         if (leader->tgid != task->tgid)
2002                 goto out_drop_task;
2003
2004         inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_INO);
2005
2006
2007         if (!inode)
2008                 goto out_drop_task;
2009         inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2010         inode->i_op = &proc_tid_base_inode_operations;
2011         inode->i_fop = &proc_tid_base_operations;
2012         inode->i_flags|=S_IMMUTABLE;
2013 #ifdef CONFIG_SECURITY
2014         inode->i_nlink = 4;
2015 #else
2016         inode->i_nlink = 3;
2017 #endif
2018
2019         dentry->d_op = &pid_base_dentry_operations;
2020
2021         d_add(dentry, inode);
2022
2023         put_task_struct(task);
2024         return NULL;
2025 out_drop_task:
2026         put_task_struct(task);
2027 out:
2028         return ERR_PTR(-ENOENT);
2029 }
2030
2031 #define PROC_NUMBUF 10
2032 #define PROC_MAXPIDS 20
2033
2034 /*
2035  * Get a few tgid's to return for filldir - we need to hold the
2036  * tasklist lock while doing this, and we must release it before
2037  * we actually do the filldir itself, so we use a temp buffer..
2038  */
2039 static int get_tgid_list(int index, unsigned long version, unsigned int *tgids)
2040 {
2041         struct task_struct *p;
2042         int nr_tgids = 0;
2043
2044         index--;
2045         read_lock(&tasklist_lock);
2046         p = NULL;
2047         if (version) {
2048                 p = find_task_by_pid(version);
2049                 if (p && !thread_group_leader(p))
2050                         p = NULL;
2051         }
2052
2053         if (p)
2054                 index = 0;
2055         else
2056                 p = next_task(&init_task);
2057
2058         for ( ; p != &init_task; p = next_task(p)) {
2059                 int tgid = p->pid;
2060                 if (!pid_alive(p))
2061                         continue;
2062                 if (--index >= 0)
2063                         continue;
2064                 tgids[nr_tgids] = tgid;
2065                 nr_tgids++;
2066                 if (nr_tgids >= PROC_MAXPIDS)
2067                         break;
2068         }
2069         read_unlock(&tasklist_lock);
2070         return nr_tgids;
2071 }
2072
2073 /*
2074  * Get a few tid's to return for filldir - we need to hold the
2075  * tasklist lock while doing this, and we must release it before
2076  * we actually do the filldir itself, so we use a temp buffer..
2077  */
2078 static int get_tid_list(int index, unsigned int *tids, struct inode *dir)
2079 {
2080         struct task_struct *leader_task = proc_task(dir);
2081         struct task_struct *task = leader_task;
2082         int nr_tids = 0;
2083
2084         index -= 2;
2085         read_lock(&tasklist_lock);
2086         /*
2087          * The starting point task (leader_task) might be an already
2088          * unlinked task, which cannot be used to access the task-list
2089          * via next_thread().
2090          */
2091         if (pid_alive(task)) do {
2092                 int tid = task->pid;
2093
2094                 if (--index >= 0)
2095                         continue;
2096                 if (tids != NULL)
2097                         tids[nr_tids] = tid;
2098                 nr_tids++;
2099                 if (nr_tids >= PROC_MAXPIDS)
2100                         break;
2101         } while ((task = next_thread(task)) != leader_task);
2102         read_unlock(&tasklist_lock);
2103         return nr_tids;
2104 }
2105
2106 /* for the /proc/ directory itself, after non-process stuff has been done */
2107 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2108 {
2109         unsigned int tgid_array[PROC_MAXPIDS];
2110         char buf[PROC_NUMBUF];
2111         unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2112         unsigned int nr_tgids, i;
2113         int next_tgid;
2114
2115         if (!nr) {
2116                 ino_t ino = fake_ino(0,PROC_TGID_INO);
2117                 if (filldir(dirent, "self", 4, filp->f_pos, ino, DT_LNK) < 0)
2118                         return 0;
2119                 filp->f_pos++;
2120                 nr++;
2121         }
2122
2123         /* f_version caches the tgid value that the last readdir call couldn't
2124          * return. lseek aka telldir automagically resets f_version to 0.
2125          */
2126         next_tgid = filp->f_version;
2127         filp->f_version = 0;
2128         for (;;) {
2129                 nr_tgids = get_tgid_list(nr, next_tgid, tgid_array);
2130                 if (!nr_tgids) {
2131                         /* no more entries ! */
2132                         break;
2133                 }
2134                 next_tgid = 0;
2135
2136                 /* do not use the last found pid, reserve it for next_tgid */
2137                 if (nr_tgids == PROC_MAXPIDS) {
2138                         nr_tgids--;
2139                         next_tgid = tgid_array[nr_tgids];
2140                 }
2141
2142                 for (i=0;i<nr_tgids;i++) {
2143                         int tgid = tgid_array[i];
2144                         ino_t ino = fake_ino(tgid,PROC_TGID_INO);
2145                         unsigned long j = PROC_NUMBUF;
2146
2147                         do
2148                                 buf[--j] = '0' + (tgid % 10);
2149                         while ((tgid /= 10) != 0);
2150
2151                         if (filldir(dirent, buf+j, PROC_NUMBUF-j, filp->f_pos, ino, DT_DIR) < 0) {
2152                                 /* returning this tgid failed, save it as the first
2153                                  * pid for the next readir call */
2154                                 filp->f_version = tgid_array[i];
2155                                 goto out;
2156                         }
2157                         filp->f_pos++;
2158                         nr++;
2159                 }
2160         }
2161 out:
2162         return 0;
2163 }
2164
2165 /* for the /proc/TGID/task/ directories */
2166 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
2167 {
2168         unsigned int tid_array[PROC_MAXPIDS];
2169         char buf[PROC_NUMBUF];
2170         unsigned int nr_tids, i;
2171         struct dentry *dentry = filp->f_dentry;
2172         struct inode *inode = dentry->d_inode;
2173         int retval = -ENOENT;
2174         ino_t ino;
2175         unsigned long pos = filp->f_pos;  /* avoiding "long long" filp->f_pos */
2176
2177         if (!pid_alive(proc_task(inode)))
2178                 goto out;
2179         retval = 0;
2180
2181         switch (pos) {
2182         case 0:
2183                 ino = inode->i_ino;
2184                 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0)
2185                         goto out;
2186                 pos++;
2187                 /* fall through */
2188         case 1:
2189                 ino = parent_ino(dentry);
2190                 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0)
2191                         goto out;
2192                 pos++;
2193                 /* fall through */
2194         }
2195
2196         nr_tids = get_tid_list(pos, tid_array, inode);
2197         inode->i_nlink = pos + nr_tids;
2198
2199         for (i = 0; i < nr_tids; i++) {
2200                 unsigned long j = PROC_NUMBUF;
2201                 int tid = tid_array[i];
2202
2203                 ino = fake_ino(tid,PROC_TID_INO);
2204
2205                 do
2206                         buf[--j] = '0' + (tid % 10);
2207                 while ((tid /= 10) != 0);
2208
2209                 if (filldir(dirent, buf+j, PROC_NUMBUF-j, pos, ino, DT_DIR) < 0)
2210                         break;
2211                 pos++;
2212         }
2213 out:
2214         filp->f_pos = pos;
2215         return retval;
2216 }