fix dangling zombie when new parent ignores children
[linux-2.6] / fs / proc / array.c
1 /*
2  *  linux/fs/proc/array.c
3  *
4  *  Copyright (C) 1992  by Linus Torvalds
5  *  based on ideas by Darren Senn
6  *
7  * Fixes:
8  * Michael. K. Johnson: stat,statm extensions.
9  *                      <johnsonm@stolaf.edu>
10  *
11  * Pauline Middelink :  Made cmdline,envline only break at '\0's, to
12  *                      make sure SET_PROCTITLE works. Also removed
13  *                      bad '!' which forced address recalculation for
14  *                      EVERY character on the current page.
15  *                      <middelin@polyware.iaf.nl>
16  *
17  * Danny ter Haar    :  added cpuinfo
18  *                      <dth@cistron.nl>
19  *
20  * Alessandro Rubini :  profile extension.
21  *                      <rubini@ipvvis.unipv.it>
22  *
23  * Jeff Tranter      :  added BogoMips field to cpuinfo
24  *                      <Jeff_Tranter@Mitel.COM>
25  *
26  * Bruno Haible      :  remove 4K limit for the maps file
27  *                      <haible@ma2s2.mathematik.uni-karlsruhe.de>
28  *
29  * Yves Arrouye      :  remove removal of trailing spaces in get_array.
30  *                      <Yves.Arrouye@marin.fdn.fr>
31  *
32  * Jerome Forissier  :  added per-CPU time information to /proc/stat
33  *                      and /proc/<pid>/cpu extension
34  *                      <forissier@isia.cma.fr>
35  *                      - Incorporation and non-SMP safe operation
36  *                      of forissier patch in 2.1.78 by
37  *                      Hans Marcus <crowbar@concepts.nl>
38  *
39  * aeb@cwi.nl        :  /proc/partitions
40  *
41  *
42  * Alan Cox          :  security fixes.
43  *                      <Alan.Cox@linux.org>
44  *
45  * Al Viro           :  safe handling of mm_struct
46  *
47  * Gerhard Wichert   :  added BIGMEM support
48  * Siemens AG           <Gerhard.Wichert@pdb.siemens.de>
49  *
50  * Al Viro & Jeff Garzik :  moved most of the thing into base.c and
51  *                       :  proc_misc.c. The rest may eventually go into
52  *                       :  base.c too.
53  */
54
55 #include <linux/types.h>
56 #include <linux/errno.h>
57 #include <linux/time.h>
58 #include <linux/kernel.h>
59 #include <linux/kernel_stat.h>
60 #include <linux/tty.h>
61 #include <linux/string.h>
62 #include <linux/mman.h>
63 #include <linux/proc_fs.h>
64 #include <linux/ioport.h>
65 #include <linux/uaccess.h>
66 #include <linux/io.h>
67 #include <linux/mm.h>
68 #include <linux/hugetlb.h>
69 #include <linux/pagemap.h>
70 #include <linux/swap.h>
71 #include <linux/slab.h>
72 #include <linux/smp.h>
73 #include <linux/signal.h>
74 #include <linux/highmem.h>
75 #include <linux/file.h>
76 #include <linux/fdtable.h>
77 #include <linux/times.h>
78 #include <linux/cpuset.h>
79 #include <linux/rcupdate.h>
80 #include <linux/delayacct.h>
81 #include <linux/seq_file.h>
82 #include <linux/pid_namespace.h>
83
84 #include <asm/pgtable.h>
85 #include <asm/processor.h>
86 #include "internal.h"
87
88 /* Gcc optimizes away "strlen(x)" for constant x */
89 #define ADDBUF(buffer, string) \
90 do { memcpy(buffer, string, strlen(string)); \
91      buffer += strlen(string); } while (0)
92
93 static inline void task_name(struct seq_file *m, struct task_struct *p)
94 {
95         int i;
96         char *buf, *end;
97         char *name;
98         char tcomm[sizeof(p->comm)];
99
100         get_task_comm(tcomm, p);
101
102         seq_printf(m, "Name:\t");
103         end = m->buf + m->size;
104         buf = m->buf + m->count;
105         name = tcomm;
106         i = sizeof(tcomm);
107         while (i && (buf < end)) {
108                 unsigned char c = *name;
109                 name++;
110                 i--;
111                 *buf = c;
112                 if (!c)
113                         break;
114                 if (c == '\\') {
115                         buf++;
116                         if (buf < end)
117                                 *buf++ = c;
118                         continue;
119                 }
120                 if (c == '\n') {
121                         *buf++ = '\\';
122                         if (buf < end)
123                                 *buf++ = 'n';
124                         continue;
125                 }
126                 buf++;
127         }
128         m->count = buf - m->buf;
129         seq_printf(m, "\n");
130 }
131
132 /*
133  * The task state array is a strange "bitmap" of
134  * reasons to sleep. Thus "running" is zero, and
135  * you can test for combinations of others with
136  * simple bit tests.
137  */
138 static const char *task_state_array[] = {
139         "R (running)",          /*  0 */
140         "S (sleeping)",         /*  1 */
141         "D (disk sleep)",       /*  2 */
142         "T (stopped)",          /*  4 */
143         "T (tracing stop)",     /*  8 */
144         "Z (zombie)",           /* 16 */
145         "X (dead)"              /* 32 */
146 };
147
148 static inline const char *get_task_state(struct task_struct *tsk)
149 {
150         unsigned int state = (tsk->state & TASK_REPORT) | tsk->exit_state;
151         const char **p = &task_state_array[0];
152
153         while (state) {
154                 p++;
155                 state >>= 1;
156         }
157         return *p;
158 }
159
160 static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
161                                 struct pid *pid, struct task_struct *p)
162 {
163         struct group_info *group_info;
164         int g;
165         struct fdtable *fdt = NULL;
166         pid_t ppid, tpid;
167
168         rcu_read_lock();
169         ppid = pid_alive(p) ?
170                 task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0;
171         tpid = pid_alive(p) && p->ptrace ?
172                 task_pid_nr_ns(rcu_dereference(p->parent), ns) : 0;
173         seq_printf(m,
174                 "State:\t%s\n"
175                 "Tgid:\t%d\n"
176                 "Pid:\t%d\n"
177                 "PPid:\t%d\n"
178                 "TracerPid:\t%d\n"
179                 "Uid:\t%d\t%d\t%d\t%d\n"
180                 "Gid:\t%d\t%d\t%d\t%d\n",
181                 get_task_state(p),
182                 task_tgid_nr_ns(p, ns),
183                 pid_nr_ns(pid, ns),
184                 ppid, tpid,
185                 p->uid, p->euid, p->suid, p->fsuid,
186                 p->gid, p->egid, p->sgid, p->fsgid);
187
188         task_lock(p);
189         if (p->files)
190                 fdt = files_fdtable(p->files);
191         seq_printf(m,
192                 "FDSize:\t%d\n"
193                 "Groups:\t",
194                 fdt ? fdt->max_fds : 0);
195         rcu_read_unlock();
196
197         group_info = p->group_info;
198         get_group_info(group_info);
199         task_unlock(p);
200
201         for (g = 0; g < min(group_info->ngroups, NGROUPS_SMALL); g++)
202                 seq_printf(m, "%d ", GROUP_AT(group_info, g));
203         put_group_info(group_info);
204
205         seq_printf(m, "\n");
206 }
207
208 static void render_sigset_t(struct seq_file *m, const char *header,
209                                 sigset_t *set)
210 {
211         int i;
212
213         seq_printf(m, "%s", header);
214
215         i = _NSIG;
216         do {
217                 int x = 0;
218
219                 i -= 4;
220                 if (sigismember(set, i+1)) x |= 1;
221                 if (sigismember(set, i+2)) x |= 2;
222                 if (sigismember(set, i+3)) x |= 4;
223                 if (sigismember(set, i+4)) x |= 8;
224                 seq_printf(m, "%x", x);
225         } while (i >= 4);
226
227         seq_printf(m, "\n");
228 }
229
230 static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *ign,
231                                     sigset_t *catch)
232 {
233         struct k_sigaction *k;
234         int i;
235
236         k = p->sighand->action;
237         for (i = 1; i <= _NSIG; ++i, ++k) {
238                 if (k->sa.sa_handler == SIG_IGN)
239                         sigaddset(ign, i);
240                 else if (k->sa.sa_handler != SIG_DFL)
241                         sigaddset(catch, i);
242         }
243 }
244
245 static inline void task_sig(struct seq_file *m, struct task_struct *p)
246 {
247         unsigned long flags;
248         sigset_t pending, shpending, blocked, ignored, caught;
249         int num_threads = 0;
250         unsigned long qsize = 0;
251         unsigned long qlim = 0;
252
253         sigemptyset(&pending);
254         sigemptyset(&shpending);
255         sigemptyset(&blocked);
256         sigemptyset(&ignored);
257         sigemptyset(&caught);
258
259         rcu_read_lock();
260         if (lock_task_sighand(p, &flags)) {
261                 pending = p->pending.signal;
262                 shpending = p->signal->shared_pending.signal;
263                 blocked = p->blocked;
264                 collect_sigign_sigcatch(p, &ignored, &caught);
265                 num_threads = atomic_read(&p->signal->count);
266                 qsize = atomic_read(&p->user->sigpending);
267                 qlim = p->signal->rlim[RLIMIT_SIGPENDING].rlim_cur;
268                 unlock_task_sighand(p, &flags);
269         }
270         rcu_read_unlock();
271
272         seq_printf(m, "Threads:\t%d\n", num_threads);
273         seq_printf(m, "SigQ:\t%lu/%lu\n", qsize, qlim);
274
275         /* render them all */
276         render_sigset_t(m, "SigPnd:\t", &pending);
277         render_sigset_t(m, "ShdPnd:\t", &shpending);
278         render_sigset_t(m, "SigBlk:\t", &blocked);
279         render_sigset_t(m, "SigIgn:\t", &ignored);
280         render_sigset_t(m, "SigCgt:\t", &caught);
281 }
282
283 static void render_cap_t(struct seq_file *m, const char *header,
284                         kernel_cap_t *a)
285 {
286         unsigned __capi;
287
288         seq_printf(m, "%s", header);
289         CAP_FOR_EACH_U32(__capi) {
290                 seq_printf(m, "%08x",
291                            a->cap[(_KERNEL_CAPABILITY_U32S-1) - __capi]);
292         }
293         seq_printf(m, "\n");
294 }
295
296 static inline void task_cap(struct seq_file *m, struct task_struct *p)
297 {
298         render_cap_t(m, "CapInh:\t", &p->cap_inheritable);
299         render_cap_t(m, "CapPrm:\t", &p->cap_permitted);
300         render_cap_t(m, "CapEff:\t", &p->cap_effective);
301         render_cap_t(m, "CapBnd:\t", &p->cap_bset);
302 }
303
304 static inline void task_context_switch_counts(struct seq_file *m,
305                                                 struct task_struct *p)
306 {
307         seq_printf(m,   "voluntary_ctxt_switches:\t%lu\n"
308                         "nonvoluntary_ctxt_switches:\t%lu\n",
309                         p->nvcsw,
310                         p->nivcsw);
311 }
312
313 int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
314                         struct pid *pid, struct task_struct *task)
315 {
316         struct mm_struct *mm = get_task_mm(task);
317
318         task_name(m, task);
319         task_state(m, ns, pid, task);
320
321         if (mm) {
322                 task_mem(m, mm);
323                 mmput(mm);
324         }
325         task_sig(m, task);
326         task_cap(m, task);
327         cpuset_task_status_allowed(m, task);
328 #if defined(CONFIG_S390)
329         task_show_regs(m, task);
330 #endif
331         task_context_switch_counts(m, task);
332         return 0;
333 }
334
335 /*
336  * Use precise platform statistics if available:
337  */
338 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
339 static cputime_t task_utime(struct task_struct *p)
340 {
341         return p->utime;
342 }
343
344 static cputime_t task_stime(struct task_struct *p)
345 {
346         return p->stime;
347 }
348 #else
349 static cputime_t task_utime(struct task_struct *p)
350 {
351         clock_t utime = cputime_to_clock_t(p->utime),
352                 total = utime + cputime_to_clock_t(p->stime);
353         u64 temp;
354
355         /*
356          * Use CFS's precise accounting:
357          */
358         temp = (u64)nsec_to_clock_t(p->se.sum_exec_runtime);
359
360         if (total) {
361                 temp *= utime;
362                 do_div(temp, total);
363         }
364         utime = (clock_t)temp;
365
366         p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime));
367         return p->prev_utime;
368 }
369
370 static cputime_t task_stime(struct task_struct *p)
371 {
372         clock_t stime;
373
374         /*
375          * Use CFS's precise accounting. (we subtract utime from
376          * the total, to make sure the total observed by userspace
377          * grows monotonically - apps rely on that):
378          */
379         stime = nsec_to_clock_t(p->se.sum_exec_runtime) -
380                         cputime_to_clock_t(task_utime(p));
381
382         if (stime >= 0)
383                 p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime));
384
385         return p->prev_stime;
386 }
387 #endif
388
389 static cputime_t task_gtime(struct task_struct *p)
390 {
391         return p->gtime;
392 }
393
394 static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
395                         struct pid *pid, struct task_struct *task, int whole)
396 {
397         unsigned long vsize, eip, esp, wchan = ~0UL;
398         long priority, nice;
399         int tty_pgrp = -1, tty_nr = 0;
400         sigset_t sigign, sigcatch;
401         char state;
402         pid_t ppid = 0, pgid = -1, sid = -1;
403         int num_threads = 0;
404         struct mm_struct *mm;
405         unsigned long long start_time;
406         unsigned long cmin_flt = 0, cmaj_flt = 0;
407         unsigned long  min_flt = 0,  maj_flt = 0;
408         cputime_t cutime, cstime, utime, stime;
409         cputime_t cgtime, gtime;
410         unsigned long rsslim = 0;
411         char tcomm[sizeof(task->comm)];
412         unsigned long flags;
413
414         state = *get_task_state(task);
415         vsize = eip = esp = 0;
416         mm = get_task_mm(task);
417         if (mm) {
418                 vsize = task_vsize(mm);
419                 eip = KSTK_EIP(task);
420                 esp = KSTK_ESP(task);
421         }
422
423         get_task_comm(tcomm, task);
424
425         sigemptyset(&sigign);
426         sigemptyset(&sigcatch);
427         cutime = cstime = utime = stime = cputime_zero;
428         cgtime = gtime = cputime_zero;
429
430         if (lock_task_sighand(task, &flags)) {
431                 struct signal_struct *sig = task->signal;
432
433                 if (sig->tty) {
434                         struct pid *pgrp = tty_get_pgrp(sig->tty);
435                         tty_pgrp = pid_nr_ns(pgrp, ns);
436                         put_pid(pgrp);
437                         tty_nr = new_encode_dev(tty_devnum(sig->tty));
438                 }
439
440                 num_threads = atomic_read(&sig->count);
441                 collect_sigign_sigcatch(task, &sigign, &sigcatch);
442
443                 cmin_flt = sig->cmin_flt;
444                 cmaj_flt = sig->cmaj_flt;
445                 cutime = sig->cutime;
446                 cstime = sig->cstime;
447                 cgtime = sig->cgtime;
448                 rsslim = sig->rlim[RLIMIT_RSS].rlim_cur;
449
450                 /* add up live thread stats at the group level */
451                 if (whole) {
452                         struct task_struct *t = task;
453                         do {
454                                 min_flt += t->min_flt;
455                                 maj_flt += t->maj_flt;
456                                 utime = cputime_add(utime, task_utime(t));
457                                 stime = cputime_add(stime, task_stime(t));
458                                 gtime = cputime_add(gtime, task_gtime(t));
459                                 t = next_thread(t);
460                         } while (t != task);
461
462                         min_flt += sig->min_flt;
463                         maj_flt += sig->maj_flt;
464                         utime = cputime_add(utime, sig->utime);
465                         stime = cputime_add(stime, sig->stime);
466                         gtime = cputime_add(gtime, sig->gtime);
467                 }
468
469                 sid = task_session_nr_ns(task, ns);
470                 ppid = task_tgid_nr_ns(task->real_parent, ns);
471                 pgid = task_pgrp_nr_ns(task, ns);
472
473                 unlock_task_sighand(task, &flags);
474         }
475
476         if (!whole || num_threads < 2)
477                 wchan = get_wchan(task);
478         if (!whole) {
479                 min_flt = task->min_flt;
480                 maj_flt = task->maj_flt;
481                 utime = task_utime(task);
482                 stime = task_stime(task);
483                 gtime = task_gtime(task);
484         }
485
486         /* scale priority and nice values from timeslices to -20..20 */
487         /* to make it look like a "normal" Unix priority/nice value  */
488         priority = task_prio(task);
489         nice = task_nice(task);
490
491         /* Temporary variable needed for gcc-2.96 */
492         /* convert timespec -> nsec*/
493         start_time =
494                 (unsigned long long)task->real_start_time.tv_sec * NSEC_PER_SEC
495                                 + task->real_start_time.tv_nsec;
496         /* convert nsec -> ticks */
497         start_time = nsec_to_clock_t(start_time);
498
499         seq_printf(m, "%d (%s) %c %d %d %d %d %d %u %lu \
500 %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
501 %lu %lu %lu %lu %lu %lu %lu %lu %d %d %u %u %llu %lu %ld\n",
502                 pid_nr_ns(pid, ns),
503                 tcomm,
504                 state,
505                 ppid,
506                 pgid,
507                 sid,
508                 tty_nr,
509                 tty_pgrp,
510                 task->flags,
511                 min_flt,
512                 cmin_flt,
513                 maj_flt,
514                 cmaj_flt,
515                 cputime_to_clock_t(utime),
516                 cputime_to_clock_t(stime),
517                 cputime_to_clock_t(cutime),
518                 cputime_to_clock_t(cstime),
519                 priority,
520                 nice,
521                 num_threads,
522                 start_time,
523                 vsize,
524                 mm ? get_mm_rss(mm) : 0,
525                 rsslim,
526                 mm ? mm->start_code : 0,
527                 mm ? mm->end_code : 0,
528                 mm ? mm->start_stack : 0,
529                 esp,
530                 eip,
531                 /* The signal information here is obsolete.
532                  * It must be decimal for Linux 2.0 compatibility.
533                  * Use /proc/#/status for real-time signals.
534                  */
535                 task->pending.signal.sig[0] & 0x7fffffffUL,
536                 task->blocked.sig[0] & 0x7fffffffUL,
537                 sigign      .sig[0] & 0x7fffffffUL,
538                 sigcatch    .sig[0] & 0x7fffffffUL,
539                 wchan,
540                 0UL,
541                 0UL,
542                 task->exit_signal,
543                 task_cpu(task),
544                 task->rt_priority,
545                 task->policy,
546                 (unsigned long long)delayacct_blkio_ticks(task),
547                 cputime_to_clock_t(gtime),
548                 cputime_to_clock_t(cgtime));
549         if (mm)
550                 mmput(mm);
551         return 0;
552 }
553
554 int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,
555                         struct pid *pid, struct task_struct *task)
556 {
557         return do_task_stat(m, ns, pid, task, 0);
558 }
559
560 int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,
561                         struct pid *pid, struct task_struct *task)
562 {
563         return do_task_stat(m, ns, pid, task, 1);
564 }
565
566 int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,
567                         struct pid *pid, struct task_struct *task)
568 {
569         int size = 0, resident = 0, shared = 0, text = 0, lib = 0, data = 0;
570         struct mm_struct *mm = get_task_mm(task);
571
572         if (mm) {
573                 size = task_statm(mm, &shared, &text, &data, &resident);
574                 mmput(mm);
575         }
576         seq_printf(m, "%d %d %d %d %d %d %d\n",
577                         size, resident, shared, text, lib, data, 0);
578
579         return 0;
580 }