Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  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/times.h>
 77 #include <linux/cpuset.h>
 78 #include <linux/rcupdate.h>
 79 #include <linux/delayacct.h>
 80 #include <linux/seq_file.h>
 81 #include <linux/pid_namespace.h>
 82 
 83 #include <asm/pgtable.h>
 84 #include <asm/processor.h>
 85 #include "internal.h"
 86 
 87 /* Gcc optimizes away "strlen(x)" for constant x */
 88 #define ADDBUF(buffer, string) \
 89 do { memcpy(buffer, string, strlen(string)); \
 90      buffer += strlen(string); } while (0)
 91 
 92 static inline void task_name(struct seq_file *m, struct task_struct *p)
 93 {
 94         int i;
 95         char *buf, *end;
 96         char *name;
 97         char tcomm[sizeof(p->comm)];
 98 
 99         get_task_comm(tcomm, p);
100 
101         seq_printf(m, "Name:\t");
102         end = m->buf + m->size;
103         buf = m->buf + m->count;
104         name = tcomm;
105         i = sizeof(tcomm);
106         while (i && (buf < end)) {
107                 unsigned char c = *name;
108                 name++;
109                 i--;
110                 *buf = c;
111                 if (!c)
112                         break;
113                 if (c == '\\') {
114                         buf++;
115                         if (buf < end)
116                                 *buf++ = c;
117                         continue;
118                 }
119                 if (c == '\n') {
120                         *buf++ = '\\';
121                         if (buf < end)
122                                 *buf++ = 'n';
123                         continue;
124                 }
125                 buf++;
126         }
127         m->count = buf - m->buf;
128         seq_printf(m, "\n");
129 }
130 
131 /*
132  * The task state array is a strange "bitmap" of
133  * reasons to sleep. Thus "running" is zero, and
134  * you can test for combinations of others with
135  * simple bit tests.
136  */
137 static const char *task_state_array[] = {
138         "R (running)",          /*  0 */
139         "M (running-mutex)",    /*  1 */
140         "S (sleeping)",         /*  2 */
141         "D (disk sleep)",       /*  4 */
142         "T (stopped)",          /*  8 */
143         "T (tracing stop)",     /* 16 */
144         "Z (zombie)",           /* 32 */
145         "X (dead)"              /* 64 */
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 }
302 
303 static inline void task_context_switch_counts(struct seq_file *m,
304                                                 struct task_struct *p)
305 {
306         seq_printf(m,   "voluntary_ctxt_switches:\t%lu\n"
307                         "nonvoluntary_ctxt_switches:\t%lu\n",
308                         p->nvcsw,
309                         p->nivcsw);
310 }
311 
312 #define get_blocked_on(t)       (-1)
313 
314 static inline void show_blocked_on(struct seq_file *m, struct task_struct *p)
315 {
316         pid_t pid = get_blocked_on(p);
317 
318         if (pid < 0)
319                 return;
320 
321         seq_printf(m, "BlckOn: %d\n", pid);
322 }
323 
324 
325 int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
326                         struct pid *pid, struct task_struct *task)
327 {
328         struct mm_struct *mm = get_task_mm(task);
329 
330         task_name(m, task);
331         task_state(m, ns, pid, task);
332 
333         if (mm) {
334                 task_mem(m, mm);
335                 mmput(mm);
336         }
337         task_sig(m, task);
338         task_cap(m, task);
339         cpuset_task_status_allowed(m, task);
340 #if defined(CONFIG_S390)
341         task_show_regs(m, task);
342 #endif
343         task_context_switch_counts(m, task);
344         show_blocked_on(m, task);
345         return 0;
346 }
347 
348 /*
349  * Use precise platform statistics if available:
350  */
351 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
352 static cputime_t task_utime(struct task_struct *p)
353 {
354         return p->utime;
355 }
356 
357 static cputime_t task_stime(struct task_struct *p)
358 {
359         return p->stime;
360 }
361 #else
362 static cputime_t task_utime(struct task_struct *p)
363 {
364         clock_t utime = cputime_to_clock_t(p->utime),
365                 total = utime + cputime_to_clock_t(p->stime);
366         u64 temp;
367 
368         /*
369          * Use CFS's precise accounting:
370          */
371         temp = (u64)nsec_to_clock_t(p->se.sum_exec_runtime);
372 
373         if (total) {
374                 temp *= utime;
375                 do_div(temp, total);
376         }
377         utime = (clock_t)temp;
378 
379         p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime));
380         return p->prev_utime;
381 }
382 
383 static cputime_t task_stime(struct task_struct *p)
384 {
385         clock_t stime;
386 
387         /*
388          * Use CFS's precise accounting. (we subtract utime from
389          * the total, to make sure the total observed by userspace
390          * grows monotonically - apps rely on that):
391          */
392         stime = nsec_to_clock_t(p->se.sum_exec_runtime) -
393                         cputime_to_clock_t(task_utime(p));
394 
395         if (stime >= 0)
396                 p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime));
397 
398         return p->prev_stime;
399 }
400 #endif
401 
402 static cputime_t task_gtime(struct task_struct *p)
403 {
404         return p->gtime;
405 }
406 
407 static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
408                         struct pid *pid, struct task_struct *task, int whole)
409 {
410         unsigned long vsize, eip, esp, wchan = ~0UL;
411         long priority, nice;
412         int tty_pgrp = -1, tty_nr = 0;
413         sigset_t sigign, sigcatch;
414         char state;
415         pid_t ppid = 0, pgid = -1, sid = -1;
416         int num_threads = 0;
417         struct mm_struct *mm;
418         unsigned long long start_time;
419         unsigned long cmin_flt = 0, cmaj_flt = 0;
420         unsigned long  min_flt = 0,  maj_flt = 0;
421         cputime_t cutime, cstime, utime, stime;
422         cputime_t cgtime, gtime;
423         unsigned long rsslim = 0;
424         char tcomm[sizeof(task->comm)];
425         unsigned long flags;
426 
427         state = *get_task_state(task);
428         vsize = eip = esp = 0;
429         mm = get_task_mm(task);
430         if (mm) {
431                 vsize = task_vsize(mm);
432                 eip = KSTK_EIP(task);
433                 esp = KSTK_ESP(task);
434         }
435 
436         get_task_comm(tcomm, task);
437 
438         sigemptyset(&sigign);
439         sigemptyset(&sigcatch);
440         cutime = cstime = utime = stime = cputime_zero;
441         cgtime = gtime = cputime_zero;
442 
443         rcu_read_lock();
444         if (lock_task_sighand(task, &flags)) {
445                 struct signal_struct *sig = task->signal;
446 
447                 if (sig->tty) {
448                         tty_pgrp = pid_nr_ns(sig->tty->pgrp, ns);
449                         tty_nr = new_encode_dev(tty_devnum(sig->tty));
450                 }
451 
452                 num_threads = atomic_read(&sig->count);
453                 collect_sigign_sigcatch(task, &sigign, &sigcatch);
454 
455                 cmin_flt = sig->cmin_flt;
456                 cmaj_flt = sig->cmaj_flt;
457                 cutime = sig->cutime;
458                 cstime = sig->cstime;
459                 cgtime = sig->cgtime;
460                 rsslim = sig->rlim[RLIMIT_RSS].rlim_cur;
461 
462                 /* add up live thread stats at the group level */
463                 if (whole) {
464                         struct task_struct *t = task;
465                         do {
466                                 min_flt += t->min_flt;
467                                 maj_flt += t->maj_flt;
468                                 utime = cputime_add(utime, task_utime(t));
469                                 stime = cputime_add(stime, task_stime(t));
470                                 gtime = cputime_add(gtime, task_gtime(t));
471                                 t = next_thread(t);
472                         } while (t != task);
473 
474                         min_flt += sig->min_flt;
475                         maj_flt += sig->maj_flt;
476                         utime = cputime_add(utime, sig->utime);
477                         stime = cputime_add(stime, sig->stime);
478                         gtime = cputime_add(gtime, sig->gtime);
479                 }
480 
481                 sid = task_session_nr_ns(task, ns);
482                 ppid = task_tgid_nr_ns(task->real_parent, ns);
483                 pgid = task_pgrp_nr_ns(task, ns);
484 
485                 unlock_task_sighand(task, &flags);
486         }
487         rcu_read_unlock();
488 
489         if (!whole || num_threads < 2)
490                 wchan = get_wchan(task);
491         if (!whole) {
492                 min_flt = task->min_flt;
493                 maj_flt = task->maj_flt;
494                 utime = task_utime(task);
495                 stime = task_stime(task);
496                 gtime = task_gtime(task);
497         }
498 
499         /* scale priority and nice values from timeslices to -20..20 */
500         /* to make it look like a "normal" Unix priority/nice value  */
501         priority = task_prio(task);
502         nice = task_nice(task);
503 
504         /* Temporary variable needed for gcc-2.96 */
505         /* convert timespec -> nsec*/
506         start_time =
507                 (unsigned long long)task->real_start_time.tv_sec * NSEC_PER_SEC
508                                 + task->real_start_time.tv_nsec;
509         /* convert nsec -> ticks */
510         start_time = nsec_to_clock_t(start_time);
511 
512         seq_printf(m, "%d (%s) %c %d %d %d %d %d %u %lu \
513 %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
514 %lu %lu %lu %lu %lu %lu %lu %lu %d %d %u %u %llu %lu %ld\n",
515                 pid_nr_ns(pid, ns),
516                 tcomm,
517                 state,
518                 ppid,
519                 pgid,
520                 sid,
521                 tty_nr,
522                 tty_pgrp,
523                 task->flags,
524                 min_flt,
525                 cmin_flt,
526                 maj_flt,
527                 cmaj_flt,
528                 cputime_to_clock_t(utime),
529                 cputime_to_clock_t(stime),
530                 cputime_to_clock_t(cutime),
531                 cputime_to_clock_t(cstime),
532                 priority,
533                 nice,
534                 num_threads,
535                 start_time,
536                 vsize,
537                 mm ? get_mm_rss(mm) : 0,
538                 rsslim,
539                 mm ? mm->start_code : 0,
540                 mm ? mm->end_code : 0,
541                 mm ? mm->start_stack : 0,
542                 esp,
543                 eip,
544                 /* The signal information here is obsolete.
545                  * It must be decimal for Linux 2.0 compatibility.
546                  * Use /proc/#/status for real-time signals.
547                  */
548                 task->pending.signal.sig[0] & 0x7fffffffUL,
549                 task->blocked.sig[0] & 0x7fffffffUL,
550                 sigign      .sig[0] & 0x7fffffffUL,
551                 sigcatch    .sig[0] & 0x7fffffffUL,
552                 wchan,
553                 0UL,
554                 0UL,
555                 task->exit_signal,
556                 task_cpu(task),
557                 task->rt_priority,
558                 task->policy,
559                 (unsigned long long)delayacct_blkio_ticks(task),
560                 cputime_to_clock_t(gtime),
561                 cputime_to_clock_t(cgtime));
562         if (mm)
563                 mmput(mm);
564         return 0;
565 }
566 
567 int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,
568                         struct pid *pid, struct task_struct *task)
569 {
570         return do_task_stat(m, ns, pid, task, 0);
571 }
572 
573 int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,
574                         struct pid *pid, struct task_struct *task)
575 {
576         return do_task_stat(m, ns, pid, task, 1);
577 }
578 
579 int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,
580                         struct pid *pid, struct task_struct *task)
581 {
582         int size = 0, resident = 0, shared = 0, text = 0, lib = 0, data = 0;
583         struct mm_struct *mm = get_task_mm(task);
584 
585         if (mm) {
586                 size = task_statm(mm, &shared, &text, &data, &resident);
587                 mmput(mm);
588         }
589         seq_printf(m, "%d %d %d %d %d %d %d\n",
590                         size, resident, shared, text, lib, data, 0);
591 
592         return 0;
593 }
594 
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