[PATCH] mounstats NULL pointer dereference
[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/mm.h>
66 #include <linux/hugetlb.h>
67 #include <linux/pagemap.h>
68 #include <linux/swap.h>
69 #include <linux/slab.h>
70 #include <linux/smp.h>
71 #include <linux/signal.h>
72 #include <linux/highmem.h>
73 #include <linux/file.h>
74 #include <linux/times.h>
75 #include <linux/cpuset.h>
76 #include <linux/rcupdate.h>
77 #include <linux/delayacct.h>
78
79 #include <asm/uaccess.h>
80 #include <asm/pgtable.h>
81 #include <asm/io.h>
82 #include <asm/processor.h>
83 #include "internal.h"
84
85 /* Gcc optimizes away "strlen(x)" for constant x */
86 #define ADDBUF(buffer, string) \
87 do { memcpy(buffer, string, strlen(string)); \
88      buffer += strlen(string); } while (0)
89
90 static inline char * task_name(struct task_struct *p, char * buf)
91 {
92         int i;
93         char * name;
94         char tcomm[sizeof(p->comm)];
95
96         get_task_comm(tcomm, p);
97
98         ADDBUF(buf, "Name:\t");
99         name = tcomm;
100         i = sizeof(tcomm);
101         do {
102                 unsigned char c = *name;
103                 name++;
104                 i--;
105                 *buf = c;
106                 if (!c)
107                         break;
108                 if (c == '\\') {
109                         buf[1] = c;
110                         buf += 2;
111                         continue;
112                 }
113                 if (c == '\n') {
114                         buf[0] = '\\';
115                         buf[1] = 'n';
116                         buf += 2;
117                         continue;
118                 }
119                 buf++;
120         } while (i);
121         *buf = '\n';
122         return buf+1;
123 }
124
125 /*
126  * The task state array is a strange "bitmap" of
127  * reasons to sleep. Thus "running" is zero, and
128  * you can test for combinations of others with
129  * simple bit tests.
130  */
131 static const char *task_state_array[] = {
132         "R (running)",          /*  0 */
133         "S (sleeping)",         /*  1 */
134         "D (disk sleep)",       /*  2 */
135         "T (stopped)",          /*  4 */
136         "T (tracing stop)",     /*  8 */
137         "Z (zombie)",           /* 16 */
138         "X (dead)"              /* 32 */
139 };
140
141 static inline const char * get_task_state(struct task_struct *tsk)
142 {
143         unsigned int state = (tsk->state & (TASK_RUNNING |
144                                             TASK_INTERRUPTIBLE |
145                                             TASK_UNINTERRUPTIBLE |
146                                             TASK_STOPPED |
147                                             TASK_TRACED)) |
148                         (tsk->exit_state & (EXIT_ZOMBIE |
149                                             EXIT_DEAD));
150         const char **p = &task_state_array[0];
151
152         while (state) {
153                 p++;
154                 state >>= 1;
155         }
156         return *p;
157 }
158
159 static inline char * task_state(struct task_struct *p, char *buffer)
160 {
161         struct group_info *group_info;
162         int g;
163         struct fdtable *fdt = NULL;
164
165         rcu_read_lock();
166         buffer += sprintf(buffer,
167                 "State:\t%s\n"
168                 "SleepAVG:\t%lu%%\n"
169                 "Tgid:\t%d\n"
170                 "Pid:\t%d\n"
171                 "PPid:\t%d\n"
172                 "TracerPid:\t%d\n"
173                 "Uid:\t%d\t%d\t%d\t%d\n"
174                 "Gid:\t%d\t%d\t%d\t%d\n",
175                 get_task_state(p),
176                 (p->sleep_avg/1024)*100/(1020000000/1024),
177                 p->tgid, p->pid,
178                 pid_alive(p) ? rcu_dereference(p->real_parent)->tgid : 0,
179                 pid_alive(p) && p->ptrace ? rcu_dereference(p->parent)->pid : 0,
180                 p->uid, p->euid, p->suid, p->fsuid,
181                 p->gid, p->egid, p->sgid, p->fsgid);
182
183         task_lock(p);
184         if (p->files)
185                 fdt = files_fdtable(p->files);
186         buffer += sprintf(buffer,
187                 "FDSize:\t%d\n"
188                 "Groups:\t",
189                 fdt ? fdt->max_fds : 0);
190         rcu_read_unlock();
191
192         group_info = p->group_info;
193         get_group_info(group_info);
194         task_unlock(p);
195
196         for (g = 0; g < min(group_info->ngroups,NGROUPS_SMALL); g++)
197                 buffer += sprintf(buffer, "%d ", GROUP_AT(group_info,g));
198         put_group_info(group_info);
199
200         buffer += sprintf(buffer, "\n");
201         return buffer;
202 }
203
204 static char * render_sigset_t(const char *header, sigset_t *set, char *buffer)
205 {
206         int i, len;
207
208         len = strlen(header);
209         memcpy(buffer, header, len);
210         buffer += len;
211
212         i = _NSIG;
213         do {
214                 int x = 0;
215
216                 i -= 4;
217                 if (sigismember(set, i+1)) x |= 1;
218                 if (sigismember(set, i+2)) x |= 2;
219                 if (sigismember(set, i+3)) x |= 4;
220                 if (sigismember(set, i+4)) x |= 8;
221                 *buffer++ = (x < 10 ? '0' : 'a' - 10) + x;
222         } while (i >= 4);
223
224         *buffer++ = '\n';
225         *buffer = 0;
226         return buffer;
227 }
228
229 static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *ign,
230                                     sigset_t *catch)
231 {
232         struct k_sigaction *k;
233         int i;
234
235         k = p->sighand->action;
236         for (i = 1; i <= _NSIG; ++i, ++k) {
237                 if (k->sa.sa_handler == SIG_IGN)
238                         sigaddset(ign, i);
239                 else if (k->sa.sa_handler != SIG_DFL)
240                         sigaddset(catch, i);
241         }
242 }
243
244 static inline char * task_sig(struct task_struct *p, char *buffer)
245 {
246         unsigned long flags;
247         sigset_t pending, shpending, blocked, ignored, caught;
248         int num_threads = 0;
249         unsigned long qsize = 0;
250         unsigned long qlim = 0;
251
252         sigemptyset(&pending);
253         sigemptyset(&shpending);
254         sigemptyset(&blocked);
255         sigemptyset(&ignored);
256         sigemptyset(&caught);
257
258         rcu_read_lock();
259         if (lock_task_sighand(p, &flags)) {
260                 pending = p->pending.signal;
261                 shpending = p->signal->shared_pending.signal;
262                 blocked = p->blocked;
263                 collect_sigign_sigcatch(p, &ignored, &caught);
264                 num_threads = atomic_read(&p->signal->count);
265                 qsize = atomic_read(&p->user->sigpending);
266                 qlim = p->signal->rlim[RLIMIT_SIGPENDING].rlim_cur;
267                 unlock_task_sighand(p, &flags);
268         }
269         rcu_read_unlock();
270
271         buffer += sprintf(buffer, "Threads:\t%d\n", num_threads);
272         buffer += sprintf(buffer, "SigQ:\t%lu/%lu\n", qsize, qlim);
273
274         /* render them all */
275         buffer = render_sigset_t("SigPnd:\t", &pending, buffer);
276         buffer = render_sigset_t("ShdPnd:\t", &shpending, buffer);
277         buffer = render_sigset_t("SigBlk:\t", &blocked, buffer);
278         buffer = render_sigset_t("SigIgn:\t", &ignored, buffer);
279         buffer = render_sigset_t("SigCgt:\t", &caught, buffer);
280
281         return buffer;
282 }
283
284 static inline char *task_cap(struct task_struct *p, char *buffer)
285 {
286     return buffer + sprintf(buffer, "CapInh:\t%016x\n"
287                             "CapPrm:\t%016x\n"
288                             "CapEff:\t%016x\n",
289                             cap_t(p->cap_inheritable),
290                             cap_t(p->cap_permitted),
291                             cap_t(p->cap_effective));
292 }
293
294 int proc_pid_status(struct task_struct *task, char * buffer)
295 {
296         char * orig = buffer;
297         struct mm_struct *mm = get_task_mm(task);
298
299         buffer = task_name(task, buffer);
300         buffer = task_state(task, buffer);
301  
302         if (mm) {
303                 buffer = task_mem(mm, buffer);
304                 mmput(mm);
305         }
306         buffer = task_sig(task, buffer);
307         buffer = task_cap(task, buffer);
308         buffer = cpuset_task_status_allowed(task, buffer);
309 #if defined(CONFIG_S390)
310         buffer = task_show_regs(task, buffer);
311 #endif
312         return buffer - orig;
313 }
314
315 static int do_task_stat(struct task_struct *task, char * buffer, int whole)
316 {
317         unsigned long vsize, eip, esp, wchan = ~0UL;
318         long priority, nice;
319         int tty_pgrp = -1, tty_nr = 0;
320         sigset_t sigign, sigcatch;
321         char state;
322         int res;
323         pid_t ppid = 0, pgid = -1, sid = -1;
324         int num_threads = 0;
325         struct mm_struct *mm;
326         unsigned long long start_time;
327         unsigned long cmin_flt = 0, cmaj_flt = 0;
328         unsigned long  min_flt = 0,  maj_flt = 0;
329         cputime_t cutime, cstime, utime, stime;
330         unsigned long rsslim = 0;
331         char tcomm[sizeof(task->comm)];
332         unsigned long flags;
333
334         state = *get_task_state(task);
335         vsize = eip = esp = 0;
336         mm = get_task_mm(task);
337         if (mm) {
338                 vsize = task_vsize(mm);
339                 eip = KSTK_EIP(task);
340                 esp = KSTK_ESP(task);
341         }
342
343         get_task_comm(tcomm, task);
344
345         sigemptyset(&sigign);
346         sigemptyset(&sigcatch);
347         cutime = cstime = utime = stime = cputime_zero;
348
349         mutex_lock(&tty_mutex);
350         rcu_read_lock();
351         if (lock_task_sighand(task, &flags)) {
352                 struct signal_struct *sig = task->signal;
353                 struct tty_struct *tty = sig->tty;
354
355                 if (tty) {
356                         /*
357                          * sig->tty is not stable, but tty_mutex
358                          * protects us from release_dev(tty)
359                          */
360                         barrier();
361                         tty_pgrp = tty->pgrp;
362                         tty_nr = new_encode_dev(tty_devnum(tty));
363                 }
364
365                 num_threads = atomic_read(&sig->count);
366                 collect_sigign_sigcatch(task, &sigign, &sigcatch);
367
368                 cmin_flt = sig->cmin_flt;
369                 cmaj_flt = sig->cmaj_flt;
370                 cutime = sig->cutime;
371                 cstime = sig->cstime;
372                 rsslim = sig->rlim[RLIMIT_RSS].rlim_cur;
373
374                 /* add up live thread stats at the group level */
375                 if (whole) {
376                         struct task_struct *t = task;
377                         do {
378                                 min_flt += t->min_flt;
379                                 maj_flt += t->maj_flt;
380                                 utime = cputime_add(utime, t->utime);
381                                 stime = cputime_add(stime, t->stime);
382                                 t = next_thread(t);
383                         } while (t != task);
384
385                         min_flt += sig->min_flt;
386                         maj_flt += sig->maj_flt;
387                         utime = cputime_add(utime, sig->utime);
388                         stime = cputime_add(stime, sig->stime);
389                 }
390
391                 sid = sig->session;
392                 pgid = process_group(task);
393                 ppid = rcu_dereference(task->real_parent)->tgid;
394
395                 unlock_task_sighand(task, &flags);
396         }
397         rcu_read_unlock();
398         mutex_unlock(&tty_mutex);
399
400         if (!whole || num_threads<2)
401                 wchan = get_wchan(task);
402         if (!whole) {
403                 min_flt = task->min_flt;
404                 maj_flt = task->maj_flt;
405                 utime = task->utime;
406                 stime = task->stime;
407         }
408
409         /* scale priority and nice values from timeslices to -20..20 */
410         /* to make it look like a "normal" Unix priority/nice value  */
411         priority = task_prio(task);
412         nice = task_nice(task);
413
414         /* Temporary variable needed for gcc-2.96 */
415         /* convert timespec -> nsec*/
416         start_time = (unsigned long long)task->start_time.tv_sec * NSEC_PER_SEC
417                                 + task->start_time.tv_nsec;
418         /* convert nsec -> ticks */
419         start_time = nsec_to_clock_t(start_time);
420
421         res = sprintf(buffer,"%d (%s) %c %d %d %d %d %d %lu %lu \
422 %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
423 %lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu %llu\n",
424                 task->pid,
425                 tcomm,
426                 state,
427                 ppid,
428                 pgid,
429                 sid,
430                 tty_nr,
431                 tty_pgrp,
432                 task->flags,
433                 min_flt,
434                 cmin_flt,
435                 maj_flt,
436                 cmaj_flt,
437                 cputime_to_clock_t(utime),
438                 cputime_to_clock_t(stime),
439                 cputime_to_clock_t(cutime),
440                 cputime_to_clock_t(cstime),
441                 priority,
442                 nice,
443                 num_threads,
444                 start_time,
445                 vsize,
446                 mm ? get_mm_rss(mm) : 0,
447                 rsslim,
448                 mm ? mm->start_code : 0,
449                 mm ? mm->end_code : 0,
450                 mm ? mm->start_stack : 0,
451                 esp,
452                 eip,
453                 /* The signal information here is obsolete.
454                  * It must be decimal for Linux 2.0 compatibility.
455                  * Use /proc/#/status for real-time signals.
456                  */
457                 task->pending.signal.sig[0] & 0x7fffffffUL,
458                 task->blocked.sig[0] & 0x7fffffffUL,
459                 sigign      .sig[0] & 0x7fffffffUL,
460                 sigcatch    .sig[0] & 0x7fffffffUL,
461                 wchan,
462                 0UL,
463                 0UL,
464                 task->exit_signal,
465                 task_cpu(task),
466                 task->rt_priority,
467                 task->policy,
468                 (unsigned long long)delayacct_blkio_ticks(task));
469         if(mm)
470                 mmput(mm);
471         return res;
472 }
473
474 int proc_tid_stat(struct task_struct *task, char * buffer)
475 {
476         return do_task_stat(task, buffer, 0);
477 }
478
479 int proc_tgid_stat(struct task_struct *task, char * buffer)
480 {
481         return do_task_stat(task, buffer, 1);
482 }
483
484 int proc_pid_statm(struct task_struct *task, char *buffer)
485 {
486         int size = 0, resident = 0, shared = 0, text = 0, lib = 0, data = 0;
487         struct mm_struct *mm = get_task_mm(task);
488         
489         if (mm) {
490                 size = task_statm(mm, &shared, &text, &data, &resident);
491                 mmput(mm);
492         }
493
494         return sprintf(buffer,"%d %d %d %d %d %d %d\n",
495                        size, resident, shared, text, lib, data, 0);
496 }