procfs: disable per-task stack usage on NOMMU
[linux-2.6.git] / 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@lxorguk.ukuu.org.uk>
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 #include <linux/ptrace.h>
84 #include <linux/tracehook.h>
85 #include <linux/swapops.h>
86
87 #include <asm/pgtable.h>
88 #include <asm/processor.h>
89 #include "internal.h"
90
91 static inline void task_name(struct seq_file *m, struct task_struct *p)
92 {
93         int i;
94         char *buf, *end;
95         char *name;
96         char tcomm[sizeof(p->comm)];
97
98         get_task_comm(tcomm, p);
99
100         seq_printf(m, "Name:\t");
101         end = m->buf + m->size;
102         buf = m->buf + m->count;
103         name = tcomm;
104         i = sizeof(tcomm);
105         while (i && (buf < end)) {
106                 unsigned char c = *name;
107                 name++;
108                 i--;
109                 *buf = c;
110                 if (!c)
111                         break;
112                 if (c == '\\') {
113                         buf++;
114                         if (buf < end)
115                                 *buf++ = c;
116                         continue;
117                 }
118                 if (c == '\n') {
119                         *buf++ = '\\';
120                         if (buf < end)
121                                 *buf++ = 'n';
122                         continue;
123                 }
124                 buf++;
125         }
126         m->count = buf - m->buf;
127         seq_printf(m, "\n");
128 }
129
130 /*
131  * The task state array is a strange "bitmap" of
132  * reasons to sleep. Thus "running" is zero, and
133  * you can test for combinations of others with
134  * simple bit tests.
135  */
136 static const char *task_state_array[] = {
137         "R (running)",          /*  0 */
138         "S (sleeping)",         /*  1 */
139         "D (disk sleep)",       /*  2 */
140         "T (stopped)",          /*  4 */
141         "T (tracing stop)",     /*  8 */
142         "Z (zombie)",           /* 16 */
143         "X (dead)"              /* 32 */
144 };
145
146 static inline const char *get_task_state(struct task_struct *tsk)
147 {
148         unsigned int state = (tsk->state & TASK_REPORT) | tsk->exit_state;
149         const char **p = &task_state_array[0];
150
151         while (state) {
152                 p++;
153                 state >>= 1;
154         }
155         return *p;
156 }
157
158 static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
159                                 struct pid *pid, struct task_struct *p)
160 {
161         struct group_info *group_info;
162         int g;
163         struct fdtable *fdt = NULL;
164         const struct cred *cred;
165         pid_t ppid, tpid;
166
167         rcu_read_lock();
168         ppid = pid_alive(p) ?
169                 task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0;
170         tpid = 0;
171         if (pid_alive(p)) {
172                 struct task_struct *tracer = tracehook_tracer_task(p);
173                 if (tracer)
174                         tpid = task_pid_nr_ns(tracer, ns);
175         }
176         cred = get_cred((struct cred *) __task_cred(p));
177         seq_printf(m,
178                 "State:\t%s\n"
179                 "Tgid:\t%d\n"
180                 "Pid:\t%d\n"
181                 "PPid:\t%d\n"
182                 "TracerPid:\t%d\n"
183                 "Uid:\t%d\t%d\t%d\t%d\n"
184                 "Gid:\t%d\t%d\t%d\t%d\n",
185                 get_task_state(p),
186                 task_tgid_nr_ns(p, ns),
187                 pid_nr_ns(pid, ns),
188                 ppid, tpid,
189                 cred->uid, cred->euid, cred->suid, cred->fsuid,
190                 cred->gid, cred->egid, cred->sgid, cred->fsgid);
191
192         task_lock(p);
193         if (p->files)
194                 fdt = files_fdtable(p->files);
195         seq_printf(m,
196                 "FDSize:\t%d\n"
197                 "Groups:\t",
198                 fdt ? fdt->max_fds : 0);
199         rcu_read_unlock();
200
201         group_info = cred->group_info;
202         task_unlock(p);
203
204         for (g = 0; g < min(group_info->ngroups, NGROUPS_SMALL); g++)
205                 seq_printf(m, "%d ", GROUP_AT(group_info, g));
206         put_cred(cred);
207
208         seq_printf(m, "\n");
209 }
210
211 static void render_sigset_t(struct seq_file *m, const char *header,
212                                 sigset_t *set)
213 {
214         int i;
215
216         seq_printf(m, "%s", header);
217
218         i = _NSIG;
219         do {
220                 int x = 0;
221
222                 i -= 4;
223                 if (sigismember(set, i+1)) x |= 1;
224                 if (sigismember(set, i+2)) x |= 2;
225                 if (sigismember(set, i+3)) x |= 4;
226                 if (sigismember(set, i+4)) x |= 8;
227                 seq_printf(m, "%x", x);
228         } while (i >= 4);
229
230         seq_printf(m, "\n");
231 }
232
233 static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *ign,
234                                     sigset_t *catch)
235 {
236         struct k_sigaction *k;
237         int i;
238
239         k = p->sighand->action;
240         for (i = 1; i <= _NSIG; ++i, ++k) {
241                 if (k->sa.sa_handler == SIG_IGN)
242                         sigaddset(ign, i);
243                 else if (k->sa.sa_handler != SIG_DFL)
244                         sigaddset(catch, i);
245         }
246 }
247
248 static inline void task_sig(struct seq_file *m, struct task_struct *p)
249 {
250         unsigned long flags;
251         sigset_t pending, shpending, blocked, ignored, caught;
252         int num_threads = 0;
253         unsigned long qsize = 0;
254         unsigned long qlim = 0;
255
256         sigemptyset(&pending);
257         sigemptyset(&shpending);
258         sigemptyset(&blocked);
259         sigemptyset(&ignored);
260         sigemptyset(&caught);
261
262         if (lock_task_sighand(p, &flags)) {
263                 pending = p->pending.signal;
264                 shpending = p->signal->shared_pending.signal;
265                 blocked = p->blocked;
266                 collect_sigign_sigcatch(p, &ignored, &caught);
267                 num_threads = atomic_read(&p->signal->count);
268                 qsize = atomic_read(&__task_cred(p)->user->sigpending);
269                 qlim = p->signal->rlim[RLIMIT_SIGPENDING].rlim_cur;
270                 unlock_task_sighand(p, &flags);
271         }
272
273         seq_printf(m, "Threads:\t%d\n", num_threads);
274         seq_printf(m, "SigQ:\t%lu/%lu\n", qsize, qlim);
275
276         /* render them all */
277         render_sigset_t(m, "SigPnd:\t", &pending);
278         render_sigset_t(m, "ShdPnd:\t", &shpending);
279         render_sigset_t(m, "SigBlk:\t", &blocked);
280         render_sigset_t(m, "SigIgn:\t", &ignored);
281         render_sigset_t(m, "SigCgt:\t", &caught);
282 }
283
284 static void render_cap_t(struct seq_file *m, const char *header,
285                         kernel_cap_t *a)
286 {
287         unsigned __capi;
288
289         seq_printf(m, "%s", header);
290         CAP_FOR_EACH_U32(__capi) {
291                 seq_printf(m, "%08x",
292                            a->cap[(_KERNEL_CAPABILITY_U32S-1) - __capi]);
293         }
294         seq_printf(m, "\n");
295 }
296
297 static inline void task_cap(struct seq_file *m, struct task_struct *p)
298 {
299         const struct cred *cred;
300         kernel_cap_t cap_inheritable, cap_permitted, cap_effective, cap_bset;
301
302         rcu_read_lock();
303         cred = __task_cred(p);
304         cap_inheritable = cred->cap_inheritable;
305         cap_permitted   = cred->cap_permitted;
306         cap_effective   = cred->cap_effective;
307         cap_bset        = cred->cap_bset;
308         rcu_read_unlock();
309
310         render_cap_t(m, "CapInh:\t", &cap_inheritable);
311         render_cap_t(m, "CapPrm:\t", &cap_permitted);
312         render_cap_t(m, "CapEff:\t", &cap_effective);
313         render_cap_t(m, "CapBnd:\t", &cap_bset);
314 }
315
316 static inline void task_context_switch_counts(struct seq_file *m,
317                                                 struct task_struct *p)
318 {
319         seq_printf(m,   "voluntary_ctxt_switches:\t%lu\n"
320                         "nonvoluntary_ctxt_switches:\t%lu\n",
321                         p->nvcsw,
322                         p->nivcsw);
323 }
324
325 #ifdef CONFIG_MMU
326
327 struct stack_stats {
328         struct vm_area_struct *vma;
329         unsigned long   startpage;
330         unsigned long   usage;
331 };
332
333 static int stack_usage_pte_range(pmd_t *pmd, unsigned long addr,
334                                 unsigned long end, struct mm_walk *walk)
335 {
336         struct stack_stats *ss = walk->private;
337         struct vm_area_struct *vma = ss->vma;
338         pte_t *pte, ptent;
339         spinlock_t *ptl;
340         int ret = 0;
341
342         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
343         for (; addr != end; pte++, addr += PAGE_SIZE) {
344                 ptent = *pte;
345
346 #ifdef CONFIG_STACK_GROWSUP
347                 if (pte_present(ptent) || is_swap_pte(ptent))
348                         ss->usage = addr - ss->startpage + PAGE_SIZE;
349 #else
350                 if (pte_present(ptent) || is_swap_pte(ptent)) {
351                         ss->usage = ss->startpage - addr + PAGE_SIZE;
352                         pte++;
353                         ret = 1;
354                         break;
355                 }
356 #endif
357         }
358         pte_unmap_unlock(pte - 1, ptl);
359         cond_resched();
360         return ret;
361 }
362
363 static inline unsigned long get_stack_usage_in_bytes(struct vm_area_struct *vma,
364                                 struct task_struct *task)
365 {
366         struct stack_stats ss;
367         struct mm_walk stack_walk = {
368                 .pmd_entry = stack_usage_pte_range,
369                 .mm = vma->vm_mm,
370                 .private = &ss,
371         };
372
373         if (!vma->vm_mm || is_vm_hugetlb_page(vma))
374                 return 0;
375
376         ss.vma = vma;
377         ss.startpage = task->stack_start & PAGE_MASK;
378         ss.usage = 0;
379
380 #ifdef CONFIG_STACK_GROWSUP
381         walk_page_range(KSTK_ESP(task) & PAGE_MASK, vma->vm_end,
382                 &stack_walk);
383 #else
384         walk_page_range(vma->vm_start, (KSTK_ESP(task) & PAGE_MASK) + PAGE_SIZE,
385                 &stack_walk);
386 #endif
387         return ss.usage;
388 }
389
390 static inline void task_show_stack_usage(struct seq_file *m,
391                                                 struct task_struct *task)
392 {
393         struct vm_area_struct   *vma;
394         struct mm_struct        *mm = get_task_mm(task);
395
396         if (mm) {
397                 down_read(&mm->mmap_sem);
398                 vma = find_vma(mm, task->stack_start);
399                 if (vma)
400                         seq_printf(m, "Stack usage:\t%lu kB\n",
401                                 get_stack_usage_in_bytes(vma, task) >> 10);
402
403                 up_read(&mm->mmap_sem);
404                 mmput(mm);
405         }
406 }
407 #else
408 static void task_show_stack_usage(struct seq_file *m, struct task_struct *task)
409 {
410 }
411 #endif          /* CONFIG_MMU */
412
413 int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
414                         struct pid *pid, struct task_struct *task)
415 {
416         struct mm_struct *mm = get_task_mm(task);
417
418         task_name(m, task);
419         task_state(m, ns, pid, task);
420
421         if (mm) {
422                 task_mem(m, mm);
423                 mmput(mm);
424         }
425         task_sig(m, task);
426         task_cap(m, task);
427         cpuset_task_status_allowed(m, task);
428 #if defined(CONFIG_S390)
429         task_show_regs(m, task);
430 #endif
431         task_context_switch_counts(m, task);
432         task_show_stack_usage(m, task);
433         return 0;
434 }
435
436 static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
437                         struct pid *pid, struct task_struct *task, int whole)
438 {
439         unsigned long vsize, eip, esp, wchan = ~0UL;
440         long priority, nice;
441         int tty_pgrp = -1, tty_nr = 0;
442         sigset_t sigign, sigcatch;
443         char state;
444         pid_t ppid = 0, pgid = -1, sid = -1;
445         int num_threads = 0;
446         int permitted;
447         struct mm_struct *mm;
448         unsigned long long start_time;
449         unsigned long cmin_flt = 0, cmaj_flt = 0;
450         unsigned long  min_flt = 0,  maj_flt = 0;
451         cputime_t cutime, cstime, utime, stime;
452         cputime_t cgtime, gtime;
453         unsigned long rsslim = 0;
454         char tcomm[sizeof(task->comm)];
455         unsigned long flags;
456
457         state = *get_task_state(task);
458         vsize = eip = esp = 0;
459         permitted = ptrace_may_access(task, PTRACE_MODE_READ);
460         mm = get_task_mm(task);
461         if (mm) {
462                 vsize = task_vsize(mm);
463                 if (permitted) {
464                         eip = KSTK_EIP(task);
465                         esp = KSTK_ESP(task);
466                 }
467         }
468
469         get_task_comm(tcomm, task);
470
471         sigemptyset(&sigign);
472         sigemptyset(&sigcatch);
473         cutime = cstime = utime = stime = cputime_zero;
474         cgtime = gtime = cputime_zero;
475
476         if (lock_task_sighand(task, &flags)) {
477                 struct signal_struct *sig = task->signal;
478
479                 if (sig->tty) {
480                         struct pid *pgrp = tty_get_pgrp(sig->tty);
481                         tty_pgrp = pid_nr_ns(pgrp, ns);
482                         put_pid(pgrp);
483                         tty_nr = new_encode_dev(tty_devnum(sig->tty));
484                 }
485
486                 num_threads = atomic_read(&sig->count);
487                 collect_sigign_sigcatch(task, &sigign, &sigcatch);
488
489                 cmin_flt = sig->cmin_flt;
490                 cmaj_flt = sig->cmaj_flt;
491                 cutime = sig->cutime;
492                 cstime = sig->cstime;
493                 cgtime = sig->cgtime;
494                 rsslim = sig->rlim[RLIMIT_RSS].rlim_cur;
495
496                 /* add up live thread stats at the group level */
497                 if (whole) {
498                         struct task_cputime cputime;
499                         struct task_struct *t = task;
500                         do {
501                                 min_flt += t->min_flt;
502                                 maj_flt += t->maj_flt;
503                                 gtime = cputime_add(gtime, task_gtime(t));
504                                 t = next_thread(t);
505                         } while (t != task);
506
507                         min_flt += sig->min_flt;
508                         maj_flt += sig->maj_flt;
509                         thread_group_cputime(task, &cputime);
510                         utime = cputime.utime;
511                         stime = cputime.stime;
512                         gtime = cputime_add(gtime, sig->gtime);
513                 }
514
515                 sid = task_session_nr_ns(task, ns);
516                 ppid = task_tgid_nr_ns(task->real_parent, ns);
517                 pgid = task_pgrp_nr_ns(task, ns);
518
519                 unlock_task_sighand(task, &flags);
520         }
521
522         if (permitted && (!whole || num_threads < 2))
523                 wchan = get_wchan(task);
524         if (!whole) {
525                 min_flt = task->min_flt;
526                 maj_flt = task->maj_flt;
527                 utime = task_utime(task);
528                 stime = task_stime(task);
529                 gtime = task_gtime(task);
530         }
531
532         /* scale priority and nice values from timeslices to -20..20 */
533         /* to make it look like a "normal" Unix priority/nice value  */
534         priority = task_prio(task);
535         nice = task_nice(task);
536
537         /* Temporary variable needed for gcc-2.96 */
538         /* convert timespec -> nsec*/
539         start_time =
540                 (unsigned long long)task->real_start_time.tv_sec * NSEC_PER_SEC
541                                 + task->real_start_time.tv_nsec;
542         /* convert nsec -> ticks */
543         start_time = nsec_to_clock_t(start_time);
544
545         seq_printf(m, "%d (%s) %c %d %d %d %d %d %u %lu \
546 %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
547 %lu %lu %lu %lu %lu %lu %lu %lu %d %d %u %u %llu %lu %ld\n",
548                 pid_nr_ns(pid, ns),
549                 tcomm,
550                 state,
551                 ppid,
552                 pgid,
553                 sid,
554                 tty_nr,
555                 tty_pgrp,
556                 task->flags,
557                 min_flt,
558                 cmin_flt,
559                 maj_flt,
560                 cmaj_flt,
561                 cputime_to_clock_t(utime),
562                 cputime_to_clock_t(stime),
563                 cputime_to_clock_t(cutime),
564                 cputime_to_clock_t(cstime),
565                 priority,
566                 nice,
567                 num_threads,
568                 start_time,
569                 vsize,
570                 mm ? get_mm_rss(mm) : 0,
571                 rsslim,
572                 mm ? mm->start_code : 0,
573                 mm ? mm->end_code : 0,
574                 (permitted) ? task->stack_start : 0,
575                 esp,
576                 eip,
577                 /* The signal information here is obsolete.
578                  * It must be decimal for Linux 2.0 compatibility.
579                  * Use /proc/#/status for real-time signals.
580                  */
581                 task->pending.signal.sig[0] & 0x7fffffffUL,
582                 task->blocked.sig[0] & 0x7fffffffUL,
583                 sigign      .sig[0] & 0x7fffffffUL,
584                 sigcatch    .sig[0] & 0x7fffffffUL,
585                 wchan,
586                 0UL,
587                 0UL,
588                 task->exit_signal,
589                 task_cpu(task),
590                 task->rt_priority,
591                 task->policy,
592                 (unsigned long long)delayacct_blkio_ticks(task),
593                 cputime_to_clock_t(gtime),
594                 cputime_to_clock_t(cgtime));
595         if (mm)
596                 mmput(mm);
597         return 0;
598 }
599
600 int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,
601                         struct pid *pid, struct task_struct *task)
602 {
603         return do_task_stat(m, ns, pid, task, 0);
604 }
605
606 int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,
607                         struct pid *pid, struct task_struct *task)
608 {
609         return do_task_stat(m, ns, pid, task, 1);
610 }
611
612 int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,
613                         struct pid *pid, struct task_struct *task)
614 {
615         int size = 0, resident = 0, shared = 0, text = 0, lib = 0, data = 0;
616         struct mm_struct *mm = get_task_mm(task);
617
618         if (mm) {
619                 size = task_statm(mm, &shared, &text, &data, &resident);
620                 mmput(mm);
621         }
622         seq_printf(m, "%d %d %d %d %d %d %d\n",
623                         size, resident, shared, text, lib, data, 0);
624
625         return 0;
626 }