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/smp.h>
  72 #include <linux/signal.h>
  73 #include <linux/highmem.h>
  74 #include <linux/file.h>
  75 #include <linux/fdtable.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 #include <linux/ptrace.h>
  83 #include <linux/tracehook.h>
  84 #include <linux/string_helpers.h>
  85 #include <linux/user_namespace.h>
  86 #include <linux/fs_struct.h>
  87
  88 #include <asm/pgtable.h>
  89 #include <asm/processor.h>
  90 #include "internal.h"
  91
  92 static inline void task_name(struct seq_file *m, struct task_struct *p)
  93 {
  94         char *buf;
  95         size_t size;
  96         char tcomm[sizeof(p->comm)];
  97         int ret;
  98
  99         get_task_comm(tcomm, p);
 100
 101         seq_puts(m, "Name:\t");
 102
 103         size = seq_get_buf(m, &buf);
 104         ret = string_escape_str(tcomm, buf, size, ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\");
 105         seq_commit(m, ret < size ? ret : -1);
 106
 107         seq_putc(m, '\n');
 108 }
 109
 110 /*
 111  * The task state array is a strange "bitmap" of
 112  * reasons to sleep. Thus "running" is zero, and
 113  * you can test for combinations of others with
 114  * simple bit tests.
 115  */
 116 static const char * const task_state_array[] = {
 117         "R (running)",          /*   0 */
 118         "S (sleeping)",         /*   1 */
 119         "D (disk sleep)",       /*   2 */
 120         "T (stopped)",          /*   4 */
 121         "t (tracing stop)",     /*   8 */
 122         "X (dead)",             /*  16 */
 123         "Z (zombie)",           /*  32 */
 124 };
 125
 126 static inline const char *get_task_state(struct task_struct *tsk)
 127 {
 128         unsigned int state = (tsk->state | tsk->exit_state) & TASK_REPORT;
 129
 130         /*
 131          * Parked tasks do not run; they sit in __kthread_parkme().
 132          * Without this check, we would report them as running, which is
 133          * clearly wrong, so we report them as sleeping instead.
 134          */
 135         if (tsk->state == TASK_PARKED)
 136                 state = TASK_INTERRUPTIBLE;
 137
 138         BUILD_BUG_ON(1 + ilog2(TASK_REPORT) != ARRAY_SIZE(task_state_array)-1);
 139
 140         return task_state_array[fls(state)];
 141 }
 142
 143 static inline int get_task_umask(struct task_struct *tsk)
 144 {
 145         struct fs_struct *fs;
 146         int umask = -ENOENT;
 147
 148         task_lock(tsk);
 149         fs = tsk->fs;
 150         if (fs)
 151                 umask = fs->umask;
 152         task_unlock(tsk);
 153         return umask;
 154 }
 155
 156 static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
 157                                 struct pid *pid, struct task_struct *p)
 158 {
 159         struct user_namespace *user_ns = seq_user_ns(m);
 160         struct group_info *group_info;
 161         int g, umask;
 162         struct task_struct *tracer;
 163         const struct cred *cred;
 164         pid_t ppid, tpid = 0, tgid, ngid;
 165         unsigned int max_fds = 0;
 166
 167         rcu_read_lock();
 168         ppid = pid_alive(p) ?
 169                 task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0;
 170
 171         tracer = ptrace_parent(p);
 172         if (tracer)
 173                 tpid = task_pid_nr_ns(tracer, ns);
 174
 175         tgid = task_tgid_nr_ns(p, ns);
 176         ngid = task_numa_group_id(p);
 177         cred = get_task_cred(p);
 178
 179         umask = get_task_umask(p);
 180         if (umask >= 0)
 181                 seq_printf(m, "Umask:\t%#04o\n", umask);
 182
 183         task_lock(p);
 184         if (p->files)
 185                 max_fds = files_fdtable(p->files)->max_fds;
 186         task_unlock(p);
 187         rcu_read_unlock();
 188
 189         seq_printf(m, "State:\t%s", get_task_state(p));
 190
 191         seq_put_decimal_ull(m, "\nTgid:\t", tgid);
 192         seq_put_decimal_ull(m, "\nNgid:\t", ngid);
 193         seq_put_decimal_ull(m, "\nPid:\t", pid_nr_ns(pid, ns));
 194         seq_put_decimal_ull(m, "\nPPid:\t", ppid);
 195         seq_put_decimal_ull(m, "\nTracerPid:\t", tpid);
 196         seq_put_decimal_ull(m, "\nUid:\t", from_kuid_munged(user_ns, cred->uid));
 197         seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->euid));
 198         seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->suid));
 199         seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->fsuid));
 200         seq_put_decimal_ull(m, "\nGid:\t", from_kgid_munged(user_ns, cred->gid));
 201         seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->egid));
 202         seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->sgid));
 203         seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->fsgid));
 204         seq_put_decimal_ull(m, "\nFDSize:\t", max_fds);
 205
 206         seq_puts(m, "\nGroups:\t");
 207         group_info = cred->group_info;
 208         for (g = 0; g < group_info->ngroups; g++)
 209                 seq_put_decimal_ull(m, g ? " " : "",
 210                                 from_kgid_munged(user_ns, group_info->gid[g]));
 211         put_cred(cred);
 212         /* Trailing space shouldn't have been added in the first place. */
 213         seq_putc(m, ' ');
 214
 215 #ifdef CONFIG_PID_NS
 216         seq_puts(m, "\nNStgid:");
 217         for (g = ns->level; g <= pid->level; g++)
 218                 seq_put_decimal_ull(m, "\t", task_tgid_nr_ns(p, pid->numbers[g].ns));
 219         seq_puts(m, "\nNSpid:");
 220         for (g = ns->level; g <= pid->level; g++)
 221                 seq_put_decimal_ull(m, "\t", task_pid_nr_ns(p, pid->numbers[g].ns));
 222         seq_puts(m, "\nNSpgid:");
 223         for (g = ns->level; g <= pid->level; g++)
 224                 seq_put_decimal_ull(m, "\t", task_pgrp_nr_ns(p, pid->numbers[g].ns));
 225         seq_puts(m, "\nNSsid:");
 226         for (g = ns->level; g <= pid->level; g++)
 227                 seq_put_decimal_ull(m, "\t", task_session_nr_ns(p, pid->numbers[g].ns));
 228 #endif
 229         seq_putc(m, '\n');
 230 }
 231
 232 void render_sigset_t(struct seq_file *m, const char *header,
 233                                 sigset_t *set)
 234 {
 235         int i;
 236
 237         seq_puts(m, header);
 238
 239         i = _NSIG;
 240         do {
 241                 int x = 0;
 242
 243                 i -= 4;
 244                 if (sigismember(set, i+1)) x |= 1;
 245                 if (sigismember(set, i+2)) x |= 2;
 246                 if (sigismember(set, i+3)) x |= 4;
 247                 if (sigismember(set, i+4)) x |= 8;
 248                 seq_putc(m, hex_asc[x]);
 249         } while (i >= 4);
 250
 251         seq_putc(m, '\n');
 252 }
 253
 254 static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *ign,
 255                                     sigset_t *catch)
 256 {
 257         struct k_sigaction *k;
 258         int i;
 259
 260         k = p->sighand->action;
 261         for (i = 1; i <= _NSIG; ++i, ++k) {
 262                 if (k->sa.sa_handler == SIG_IGN)
 263                         sigaddset(ign, i);
 264                 else if (k->sa.sa_handler != SIG_DFL)
 265                         sigaddset(catch, i);
 266         }
 267 }
 268
 269 static inline void task_sig(struct seq_file *m, struct task_struct *p)
 270 {
 271         unsigned long flags;
 272         sigset_t pending, shpending, blocked, ignored, caught;
 273         int num_threads = 0;
 274         unsigned long qsize = 0;
 275         unsigned long qlim = 0;
 276
 277         sigemptyset(&pending);
 278         sigemptyset(&shpending);
 279         sigemptyset(&blocked);
 280         sigemptyset(&ignored);
 281         sigemptyset(&caught);
 282
 283         if (lock_task_sighand(p, &flags)) {
 284                 pending = p->pending.signal;
 285                 shpending = p->signal->shared_pending.signal;
 286                 blocked = p->blocked;
 287                 collect_sigign_sigcatch(p, &ignored, &caught);
 288                 num_threads = get_nr_threads(p);
 289                 rcu_read_lock();  /* FIXME: is this correct? */
 290                 qsize = atomic_read(&__task_cred(p)->user->sigpending);
 291                 rcu_read_unlock();
 292                 qlim = task_rlimit(p, RLIMIT_SIGPENDING);
 293                 unlock_task_sighand(p, &flags);
 294         }
 295
 296         seq_put_decimal_ull(m, "Threads:\t", num_threads);
 297         seq_put_decimal_ull(m, "\nSigQ:\t", qsize);
 298         seq_put_decimal_ull(m, "/", qlim);
 299
 300         /* render them all */
 301         render_sigset_t(m, "\nSigPnd:\t", &pending);
 302         render_sigset_t(m, "ShdPnd:\t", &shpending);
 303         render_sigset_t(m, "SigBlk:\t", &blocked);
 304         render_sigset_t(m, "SigIgn:\t", &ignored);
 305         render_sigset_t(m, "SigCgt:\t", &caught);
 306 }
 307
 308 static void render_cap_t(struct seq_file *m, const char *header,
 309                         kernel_cap_t *a)
 310 {
 311         unsigned __capi;
 312
 313         seq_puts(m, header);
 314         CAP_FOR_EACH_U32(__capi) {
 315                 seq_printf(m, "%08x",
 316                            a->cap[CAP_LAST_U32 - __capi]);
 317         }
 318         seq_putc(m, '\n');
 319 }
 320
 321 static inline void task_cap(struct seq_file *m, struct task_struct *p)
 322 {
 323         const struct cred *cred;
 324         kernel_cap_t cap_inheritable, cap_permitted, cap_effective,
 325                         cap_bset, cap_ambient;
 326
 327         rcu_read_lock();
 328         cred = __task_cred(p);
 329         cap_inheritable = cred->cap_inheritable;
 330         cap_permitted   = cred->cap_permitted;
 331         cap_effective   = cred->cap_effective;
 332         cap_bset        = cred->cap_bset;
 333         cap_ambient     = cred->cap_ambient;
 334         rcu_read_unlock();
 335
 336         render_cap_t(m, "CapInh:\t", &cap_inheritable);
 337         render_cap_t(m, "CapPrm:\t", &cap_permitted);
 338         render_cap_t(m, "CapEff:\t", &cap_effective);
 339         render_cap_t(m, "CapBnd:\t", &cap_bset);
 340         render_cap_t(m, "CapAmb:\t", &cap_ambient);
 341 }
 342
 343 static inline void task_seccomp(struct seq_file *m, struct task_struct *p)
 344 {
 345         seq_put_decimal_ull(m, "NoNewPrivs:\t", task_no_new_privs(p));
 346 #ifdef CONFIG_SECCOMP
 347         seq_put_decimal_ull(m, "\nSeccomp:\t", p->seccomp.mode);
 348 #endif
 349         seq_putc(m, '\n');
 350 }
 351
 352 static inline void task_context_switch_counts(struct seq_file *m,
 353                                                 struct task_struct *p)
 354 {
 355         seq_put_decimal_ull(m, "voluntary_ctxt_switches:\t", p->nvcsw);
 356         seq_put_decimal_ull(m, "\nnonvoluntary_ctxt_switches:\t", p->nivcsw);
 357         seq_putc(m, '\n');
 358 }
 359
 360 static void task_cpus_allowed(struct seq_file *m, struct task_struct *task)
 361 {
 362         seq_printf(m, "Cpus_allowed:\t%*pb\n",
 363                    cpumask_pr_args(&task->cpus_allowed));
 364         seq_printf(m, "Cpus_allowed_list:\t%*pbl\n",
 365                    cpumask_pr_args(&task->cpus_allowed));
 366 }
 367
 368 int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
 369                         struct pid *pid, struct task_struct *task)
 370 {
 371         struct mm_struct *mm = get_task_mm(task);
 372
 373         task_name(m, task);
 374         task_state(m, ns, pid, task);
 375
 376         if (mm) {
 377                 task_mem(m, mm);
 378                 mmput(mm);
 379         }
 380         task_sig(m, task);
 381         task_cap(m, task);
 382         task_seccomp(m, task);
 383         task_cpus_allowed(m, task);
 384         cpuset_task_status_allowed(m, task);
 385         task_context_switch_counts(m, task);
 386         return 0;
 387 }
 388
 389 static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
 390                         struct pid *pid, struct task_struct *task, int whole)
 391 {
 392         unsigned long vsize, eip, esp, wchan = 0;
 393         int priority, nice;
 394         int tty_pgrp = -1, tty_nr = 0;
 395         sigset_t sigign, sigcatch;
 396         char state;
 397         pid_t ppid = 0, pgid = -1, sid = -1;
 398         int num_threads = 0;
 399         int permitted;
 400         struct mm_struct *mm;
 401         unsigned long long start_time;
 402         unsigned long cmin_flt = 0, cmaj_flt = 0;
 403         unsigned long  min_flt = 0,  maj_flt = 0;
 404         cputime_t cutime, cstime, utime, stime;
 405         cputime_t cgtime, gtime;
 406         unsigned long rsslim = 0;
 407         char tcomm[sizeof(task->comm)];
 408         unsigned long flags;
 409
 410         state = *get_task_state(task);
 411         vsize = eip = esp = 0;
 412         permitted = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS | PTRACE_MODE_NOAUDIT);
 413         mm = get_task_mm(task);
 414         if (mm) {
 415                 vsize = task_vsize(mm);
 416                 /*
 417                  * esp and eip are intentionally zeroed out.  There is no
 418                  * non-racy way to read them without freezing the task.
 419                  * Programs that need reliable values can use ptrace(2).
 420                  */
 421         }
 422
 423         get_task_comm(tcomm, task);
 424
 425         sigemptyset(&sigign);
 426         sigemptyset(&sigcatch);
 427         cutime = cstime = utime = stime = 0;
 428         cgtime = gtime = 0;
 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 = get_nr_threads(task);
 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 = ACCESS_ONCE(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                                 gtime += task_gtime(t);
 457                         } while_each_thread(task, t);
 458
 459                         min_flt += sig->min_flt;
 460                         maj_flt += sig->maj_flt;
 461                         thread_group_cputime_adjusted(task, &utime, &stime);
 462                         gtime += sig->gtime;
 463                 }
 464
 465                 sid = task_session_nr_ns(task, ns);
 466                 ppid = task_tgid_nr_ns(task->real_parent, ns);
 467                 pgid = task_pgrp_nr_ns(task, ns);
 468
 469                 unlock_task_sighand(task, &flags);
 470         }
 471
 472         if (permitted && (!whole || num_threads < 2))
 473                 wchan = get_wchan(task);
 474         if (!whole) {
 475                 min_flt = task->min_flt;
 476                 maj_flt = task->maj_flt;
 477                 task_cputime_adjusted(task, &utime, &stime);
 478                 gtime = task_gtime(task);
 479         }
 480
 481         /* scale priority and nice values from timeslices to -20..20 */
 482         /* to make it look like a "normal" Unix priority/nice value  */
 483         priority = task_prio(task);
 484         nice = task_nice(task);
 485
 486         /* convert nsec -> ticks */
 487         start_time = nsec_to_clock_t(task->real_start_time);
 488
 489         seq_printf(m, "%d (%s) %c", pid_nr_ns(pid, ns), tcomm, state);
 490         seq_put_decimal_ll(m, " ", ppid);
 491         seq_put_decimal_ll(m, " ", pgid);
 492         seq_put_decimal_ll(m, " ", sid);
 493         seq_put_decimal_ll(m, " ", tty_nr);
 494         seq_put_decimal_ll(m, " ", tty_pgrp);
 495         seq_put_decimal_ull(m, " ", task->flags);
 496         seq_put_decimal_ull(m, " ", min_flt);
 497         seq_put_decimal_ull(m, " ", cmin_flt);
 498         seq_put_decimal_ull(m, " ", maj_flt);
 499         seq_put_decimal_ull(m, " ", cmaj_flt);
 500         seq_put_decimal_ull(m, " ", cputime_to_clock_t(utime));
 501         seq_put_decimal_ull(m, " ", cputime_to_clock_t(stime));
 502         seq_put_decimal_ll(m, " ", cputime_to_clock_t(cutime));
 503         seq_put_decimal_ll(m, " ", cputime_to_clock_t(cstime));
 504         seq_put_decimal_ll(m, " ", priority);
 505         seq_put_decimal_ll(m, " ", nice);
 506         seq_put_decimal_ll(m, " ", num_threads);
 507         seq_put_decimal_ull(m, " ", 0);
 508         seq_put_decimal_ull(m, " ", start_time);
 509         seq_put_decimal_ull(m, " ", vsize);
 510         seq_put_decimal_ull(m, " ", mm ? get_mm_rss(mm) : 0);
 511         seq_put_decimal_ull(m, " ", rsslim);
 512         seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->start_code : 1) : 0);
 513         seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->end_code : 1) : 0);
 514         seq_put_decimal_ull(m, " ", (permitted && mm) ? mm->start_stack : 0);
 515         seq_put_decimal_ull(m, " ", esp);
 516         seq_put_decimal_ull(m, " ", eip);
 517         /* The signal information here is obsolete.
 518          * It must be decimal for Linux 2.0 compatibility.
 519          * Use /proc/#/status for real-time signals.
 520          */
 521         seq_put_decimal_ull(m, " ", task->pending.signal.sig[0] & 0x7fffffffUL);
 522         seq_put_decimal_ull(m, " ", task->blocked.sig[0] & 0x7fffffffUL);
 523         seq_put_decimal_ull(m, " ", sigign.sig[0] & 0x7fffffffUL);
 524         seq_put_decimal_ull(m, " ", sigcatch.sig[0] & 0x7fffffffUL);
 525
 526         /*
 527          * We used to output the absolute kernel address, but that's an
 528          * information leak - so instead we show a 0/1 flag here, to signal
 529          * to user-space whether there's a wchan field in /proc/PID/wchan.
 530          *
 531          * This works with older implementations of procps as well.
 532          */
 533         if (wchan)
 534                 seq_puts(m, " 1");
 535         else
 536                 seq_puts(m, " 0");
 537
 538         seq_put_decimal_ull(m, " ", 0);
 539         seq_put_decimal_ull(m, " ", 0);
 540         seq_put_decimal_ll(m, " ", task->exit_signal);
 541         seq_put_decimal_ll(m, " ", task_cpu(task));
 542         seq_put_decimal_ull(m, " ", task->rt_priority);
 543         seq_put_decimal_ull(m, " ", task->policy);
 544         seq_put_decimal_ull(m, " ", delayacct_blkio_ticks(task));
 545         seq_put_decimal_ull(m, " ", cputime_to_clock_t(gtime));
 546         seq_put_decimal_ll(m, " ", cputime_to_clock_t(cgtime));
 547
 548         if (mm && permitted) {
 549                 seq_put_decimal_ull(m, " ", mm->start_data);
 550                 seq_put_decimal_ull(m, " ", mm->end_data);
 551                 seq_put_decimal_ull(m, " ", mm->start_brk);
 552                 seq_put_decimal_ull(m, " ", mm->arg_start);
 553                 seq_put_decimal_ull(m, " ", mm->arg_end);
 554                 seq_put_decimal_ull(m, " ", mm->env_start);
 555                 seq_put_decimal_ull(m, " ", mm->env_end);
 556         } else
 557                 seq_puts(m, " 0 0 0 0 0 0 0");
 558
 559         if (permitted)
 560                 seq_put_decimal_ll(m, " ", task->exit_code);
 561         else
 562                 seq_puts(m, " 0");
 563
 564         seq_putc(m, '\n');
 565         if (mm)
 566                 mmput(mm);
 567         return 0;
 568 }
 569
 570 int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,
 571                         struct pid *pid, struct task_struct *task)
 572 {
 573         return do_task_stat(m, ns, pid, task, 0);
 574 }
 575
 576 int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,
 577                         struct pid *pid, struct task_struct *task)
 578 {
 579         return do_task_stat(m, ns, pid, task, 1);
 580 }
 581
 582 int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,
 583                         struct pid *pid, struct task_struct *task)
 584 {
 585         unsigned long size = 0, resident = 0, shared = 0, text = 0, data = 0;
 586         struct mm_struct *mm = get_task_mm(task);
 587
 588         if (mm) {
 589                 size = task_statm(mm, &shared, &text, &data, &resident);
 590                 mmput(mm);
 591         }
 592         /*
 593          * For quick read, open code by putting numbers directly
 594          * expected format is
 595          * seq_printf(m, "%lu %lu %lu %lu 0 %lu 0\n",
 596          *               size, resident, shared, text, data);
 597          */
 598         seq_put_decimal_ull(m, "", size);
 599         seq_put_decimal_ull(m, " ", resident);
 600         seq_put_decimal_ull(m, " ", shared);
 601         seq_put_decimal_ull(m, " ", text);
 602         seq_put_decimal_ull(m, " ", 0);
 603         seq_put_decimal_ull(m, " ", data);
 604         seq_put_decimal_ull(m, " ", 0);
 605         seq_putc(m, '\n');
 606
 607         return 0;
 608 }
 609
 610 #ifdef CONFIG_PROC_CHILDREN
 611 static struct pid *
 612 get_children_pid(struct inode *inode, struct pid *pid_prev, loff_t pos)
 613 {
 614         struct task_struct *start, *task;
 615         struct pid *pid = NULL;
 616
 617         read_lock(&tasklist_lock);
 618
 619         start = pid_task(proc_pid(inode), PIDTYPE_PID);
 620         if (!start)
 621                 goto out;
 622
 623         /*
 624          * Lets try to continue searching first, this gives
 625          * us significant speedup on children-rich processes.
 626          */
 627         if (pid_prev) {
 628                 task = pid_task(pid_prev, PIDTYPE_PID);
 629                 if (task && task->real_parent == start &&
 630                     !(list_empty(&task->sibling))) {
 631                         if (list_is_last(&task->sibling, &start->children))
 632                                 goto out;
 633                         task = list_first_entry(&task->sibling,
 634                                                 struct task_struct, sibling);
 635                         pid = get_pid(task_pid(task));
 636                         goto out;
 637                 }
 638         }
 639
 640         /*
 641          * Slow search case.
 642          *
 643          * We might miss some children here if children
 644          * are exited while we were not holding the lock,
 645          * but it was never promised to be accurate that
 646          * much.
 647          *
 648          * "Just suppose that the parent sleeps, but N children
 649          *  exit after we printed their tids. Now the slow paths
 650          *  skips N extra children, we miss N tasks." (c)
 651          *
 652          * So one need to stop or freeze the leader and all
 653          * its children to get a precise result.
 654          */
 655         list_for_each_entry(task, &start->children, sibling) {
 656                 if (pos-- == 0) {
 657                         pid = get_pid(task_pid(task));
 658                         break;
 659                 }
 660         }
 661
 662 out:
 663         read_unlock(&tasklist_lock);
 664         return pid;
 665 }
 666
 667 static int children_seq_show(struct seq_file *seq, void *v)
 668 {
 669         struct inode *inode = seq->private;
 670         pid_t pid;
 671
 672         pid = pid_nr_ns(v, inode->i_sb->s_fs_info);
 673         seq_printf(seq, "%d ", pid);
 674
 675         return 0;
 676 }
 677
 678 static void *children_seq_start(struct seq_file *seq, loff_t *pos)
 679 {
 680         return get_children_pid(seq->private, NULL, *pos);
 681 }
 682
 683 static void *children_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 684 {
 685         struct pid *pid;
 686
 687         pid = get_children_pid(seq->private, v, *pos + 1);
 688         put_pid(v);
 689
 690         ++*pos;
 691         return pid;
 692 }
 693
 694 static void children_seq_stop(struct seq_file *seq, void *v)
 695 {
 696         put_pid(v);
 697 }
 698
 699 static const struct seq_operations children_seq_ops = {
 700         .start  = children_seq_start,
 701         .next   = children_seq_next,
 702         .stop   = children_seq_stop,
 703         .show   = children_seq_show,
 704 };
 705
 706 static int children_seq_open(struct inode *inode, struct file *file)
 707 {
 708         struct seq_file *m;
 709         int ret;
 710
 711         ret = seq_open(file, &children_seq_ops);
 712         if (ret)
 713                 return ret;
 714
 715         m = file->private_data;
 716         m->private = inode;
 717
 718         return ret;
 719 }
 720
 721 int children_seq_release(struct inode *inode, struct file *file)
 722 {
 723         seq_release(inode, file);
 724         return 0;
 725 }
 726
 727 const struct file_operations proc_tid_children_operations = {
 728         .open    = children_seq_open,
 729         .read    = seq_read,
 730         .llseek  = seq_lseek,
 731         .release = children_seq_release,
 732 };
 733 #endif /* CONFIG_PROC_CHILDREN */