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/sched/mm.h>
  64 #include <linux/sched/numa_balancing.h>
  65 #include <linux/sched/task.h>
  66 #include <linux/sched/cputime.h>
  67 #include <linux/proc_fs.h>
  68 #include <linux/ioport.h>
  69 #include <linux/uaccess.h>
  70 #include <linux/io.h>
  71 #include <linux/mm.h>
  72 #include <linux/hugetlb.h>
  73 #include <linux/pagemap.h>
  74 #include <linux/swap.h>
  75 #include <linux/smp.h>
  76 #include <linux/signal.h>
  77 #include <linux/highmem.h>
  78 #include <linux/file.h>
  79 #include <linux/fdtable.h>
  80 #include <linux/times.h>
  81 #include <linux/cpuset.h>
  82 #include <linux/rcupdate.h>
  83 #include <linux/delayacct.h>
  84 #include <linux/seq_file.h>
  85 #include <linux/pid_namespace.h>
  86 #include <linux/ptrace.h>
  87 #include <linux/tracehook.h>
  88 #include <linux/string_helpers.h>
  89 #include <linux/user_namespace.h>
  90 #include <linux/fs_struct.h>
  91
  92 #include <asm/pgtable.h>
  93 #include <asm/processor.h>
  94 #include "internal.h"
  95
  96 static inline void task_name(struct seq_file *m, struct task_struct *p)
  97 {
  98         char *buf;
  99         size_t size;
 100         char tcomm[sizeof(p->comm)];
 101         int ret;
 102
 103         get_task_comm(tcomm, p);
 104
 105         seq_puts(m, "Name:\t");
 106
 107         size = seq_get_buf(m, &buf);
 108         ret = string_escape_str(tcomm, buf, size, ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\");
 109         seq_commit(m, ret < size ? ret : -1);
 110
 111         seq_putc(m, '\n');
 112 }
 113
 114 /*
 115  * The task state array is a strange "bitmap" of
 116  * reasons to sleep. Thus "running" is zero, and
 117  * you can test for combinations of others with
 118  * simple bit tests.
 119  */
 120 static const char * const task_state_array[] = {
 121         "R (running)",          /*   0 */
 122         "S (sleeping)",         /*   1 */
 123         "D (disk sleep)",       /*   2 */
 124         "T (stopped)",          /*   4 */
 125         "t (tracing stop)",     /*   8 */
 126         "X (dead)",             /*  16 */
 127         "Z (zombie)",           /*  32 */
 128 };
 129
 130 static inline const char *get_task_state(struct task_struct *tsk)
 131 {
 132         unsigned int state = (tsk->state | tsk->exit_state) & TASK_REPORT;
 133
 134         /*
 135          * Parked tasks do not run; they sit in __kthread_parkme().
 136          * Without this check, we would report them as running, which is
 137          * clearly wrong, so we report them as sleeping instead.
 138          */
 139         if (tsk->state == TASK_PARKED)
 140                 state = TASK_INTERRUPTIBLE;
 141
 142         BUILD_BUG_ON(1 + ilog2(TASK_REPORT) != ARRAY_SIZE(task_state_array)-1);
 143
 144         return task_state_array[fls(state)];
 145 }
 146
 147 static inline int get_task_umask(struct task_struct *tsk)
 148 {
 149         struct fs_struct *fs;
 150         int umask = -ENOENT;
 151
 152         task_lock(tsk);
 153         fs = tsk->fs;
 154         if (fs)
 155                 umask = fs->umask;
 156         task_unlock(tsk);
 157         return umask;
 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 user_namespace *user_ns = seq_user_ns(m);
 164         struct group_info *group_info;
 165         int g, umask;
 166         struct task_struct *tracer;
 167         const struct cred *cred;
 168         pid_t ppid, tpid = 0, tgid, ngid;
 169         unsigned int max_fds = 0;
 170
 171         rcu_read_lock();
 172         ppid = pid_alive(p) ?
 173                 task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0;
 174
 175         tracer = ptrace_parent(p);
 176         if (tracer)
 177                 tpid = task_pid_nr_ns(tracer, ns);
 178
 179         tgid = task_tgid_nr_ns(p, ns);
 180         ngid = task_numa_group_id(p);
 181         cred = get_task_cred(p);
 182
 183         umask = get_task_umask(p);
 184         if (umask >= 0)
 185                 seq_printf(m, "Umask:\t%#04o\n", umask);
 186
 187         task_lock(p);
 188         if (p->files)
 189                 max_fds = files_fdtable(p->files)->max_fds;
 190         task_unlock(p);
 191         rcu_read_unlock();
 192
 193         seq_printf(m, "State:\t%s", get_task_state(p));
 194
 195         seq_put_decimal_ull(m, "\nTgid:\t", tgid);
 196         seq_put_decimal_ull(m, "\nNgid:\t", ngid);
 197         seq_put_decimal_ull(m, "\nPid:\t", pid_nr_ns(pid, ns));
 198         seq_put_decimal_ull(m, "\nPPid:\t", ppid);
 199         seq_put_decimal_ull(m, "\nTracerPid:\t", tpid);
 200         seq_put_decimal_ull(m, "\nUid:\t", from_kuid_munged(user_ns, cred->uid));
 201         seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->euid));
 202         seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->suid));
 203         seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->fsuid));
 204         seq_put_decimal_ull(m, "\nGid:\t", from_kgid_munged(user_ns, cred->gid));
 205         seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->egid));
 206         seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->sgid));
 207         seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->fsgid));
 208         seq_put_decimal_ull(m, "\nFDSize:\t", max_fds);
 209
 210         seq_puts(m, "\nGroups:\t");
 211         group_info = cred->group_info;
 212         for (g = 0; g < group_info->ngroups; g++)
 213                 seq_put_decimal_ull(m, g ? " " : "",
 214                                 from_kgid_munged(user_ns, group_info->gid[g]));
 215         put_cred(cred);
 216         /* Trailing space shouldn't have been added in the first place. */
 217         seq_putc(m, ' ');
 218
 219 #ifdef CONFIG_PID_NS
 220         seq_puts(m, "\nNStgid:");
 221         for (g = ns->level; g <= pid->level; g++)
 222                 seq_put_decimal_ull(m, "\t", task_tgid_nr_ns(p, pid->numbers[g].ns));
 223         seq_puts(m, "\nNSpid:");
 224         for (g = ns->level; g <= pid->level; g++)
 225                 seq_put_decimal_ull(m, "\t", task_pid_nr_ns(p, pid->numbers[g].ns));
 226         seq_puts(m, "\nNSpgid:");
 227         for (g = ns->level; g <= pid->level; g++)
 228                 seq_put_decimal_ull(m, "\t", task_pgrp_nr_ns(p, pid->numbers[g].ns));
 229         seq_puts(m, "\nNSsid:");
 230         for (g = ns->level; g <= pid->level; g++)
 231                 seq_put_decimal_ull(m, "\t", task_session_nr_ns(p, pid->numbers[g].ns));
 232 #endif
 233         seq_putc(m, '\n');
 234 }
 235
 236 void render_sigset_t(struct seq_file *m, const char *header,
 237                                 sigset_t *set)
 238 {
 239         int i;
 240
 241         seq_puts(m, header);
 242
 243         i = _NSIG;
 244         do {
 245                 int x = 0;
 246
 247                 i -= 4;
 248                 if (sigismember(set, i+1)) x |= 1;
 249                 if (sigismember(set, i+2)) x |= 2;
 250                 if (sigismember(set, i+3)) x |= 4;
 251                 if (sigismember(set, i+4)) x |= 8;
 252                 seq_putc(m, hex_asc[x]);
 253         } while (i >= 4);
 254
 255         seq_putc(m, '\n');
 256 }
 257
 258 static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *ign,
 259                                     sigset_t *catch)
 260 {
 261         struct k_sigaction *k;
 262         int i;
 263
 264         k = p->sighand->action;
 265         for (i = 1; i <= _NSIG; ++i, ++k) {
 266                 if (k->sa.sa_handler == SIG_IGN)
 267                         sigaddset(ign, i);
 268                 else if (k->sa.sa_handler != SIG_DFL)
 269                         sigaddset(catch, i);
 270         }
 271 }
 272
 273 static inline void task_sig(struct seq_file *m, struct task_struct *p)
 274 {
 275         unsigned long flags;
 276         sigset_t pending, shpending, blocked, ignored, caught;
 277         int num_threads = 0;
 278         unsigned long qsize = 0;
 279         unsigned long qlim = 0;
 280
 281         sigemptyset(&pending);
 282         sigemptyset(&shpending);
 283         sigemptyset(&blocked);
 284         sigemptyset(&ignored);
 285         sigemptyset(&caught);
 286
 287         if (lock_task_sighand(p, &flags)) {
 288                 pending = p->pending.signal;
 289                 shpending = p->signal->shared_pending.signal;
 290                 blocked = p->blocked;
 291                 collect_sigign_sigcatch(p, &ignored, &caught);
 292                 num_threads = get_nr_threads(p);
 293                 rcu_read_lock();  /* FIXME: is this correct? */
 294                 qsize = atomic_read(&__task_cred(p)->user->sigpending);
 295                 rcu_read_unlock();
 296                 qlim = task_rlimit(p, RLIMIT_SIGPENDING);
 297                 unlock_task_sighand(p, &flags);
 298         }
 299
 300         seq_put_decimal_ull(m, "Threads:\t", num_threads);
 301         seq_put_decimal_ull(m, "\nSigQ:\t", qsize);
 302         seq_put_decimal_ull(m, "/", qlim);
 303
 304         /* render them all */
 305         render_sigset_t(m, "\nSigPnd:\t", &pending);
 306         render_sigset_t(m, "ShdPnd:\t", &shpending);
 307         render_sigset_t(m, "SigBlk:\t", &blocked);
 308         render_sigset_t(m, "SigIgn:\t", &ignored);
 309         render_sigset_t(m, "SigCgt:\t", &caught);
 310 }
 311
 312 static void render_cap_t(struct seq_file *m, const char *header,
 313                         kernel_cap_t *a)
 314 {
 315         unsigned __capi;
 316
 317         seq_puts(m, header);
 318         CAP_FOR_EACH_U32(__capi) {
 319                 seq_printf(m, "%08x",
 320                            a->cap[CAP_LAST_U32 - __capi]);
 321         }
 322         seq_putc(m, '\n');
 323 }
 324
 325 static inline void task_cap(struct seq_file *m, struct task_struct *p)
 326 {
 327         const struct cred *cred;
 328         kernel_cap_t cap_inheritable, cap_permitted, cap_effective,
 329                         cap_bset, cap_ambient;
 330
 331         rcu_read_lock();
 332         cred = __task_cred(p);
 333         cap_inheritable = cred->cap_inheritable;
 334         cap_permitted   = cred->cap_permitted;
 335         cap_effective   = cred->cap_effective;
 336         cap_bset        = cred->cap_bset;
 337         cap_ambient     = cred->cap_ambient;
 338         rcu_read_unlock();
 339
 340         render_cap_t(m, "CapInh:\t", &cap_inheritable);
 341         render_cap_t(m, "CapPrm:\t", &cap_permitted);
 342         render_cap_t(m, "CapEff:\t", &cap_effective);
 343         render_cap_t(m, "CapBnd:\t", &cap_bset);
 344         render_cap_t(m, "CapAmb:\t", &cap_ambient);
 345 }
 346
 347 static inline void task_seccomp(struct seq_file *m, struct task_struct *p)
 348 {
 349         seq_put_decimal_ull(m, "NoNewPrivs:\t", task_no_new_privs(p));
 350 #ifdef CONFIG_SECCOMP
 351         seq_put_decimal_ull(m, "\nSeccomp:\t", p->seccomp.mode);
 352 #endif
 353         seq_putc(m, '\n');
 354 }
 355
 356 static inline void task_context_switch_counts(struct seq_file *m,
 357                                                 struct task_struct *p)
 358 {
 359         seq_put_decimal_ull(m, "voluntary_ctxt_switches:\t", p->nvcsw);
 360         seq_put_decimal_ull(m, "\nnonvoluntary_ctxt_switches:\t", p->nivcsw);
 361         seq_putc(m, '\n');
 362 }
 363
 364 static void task_cpus_allowed(struct seq_file *m, struct task_struct *task)
 365 {
 366         seq_printf(m, "Cpus_allowed:\t%*pb\n",
 367                    cpumask_pr_args(&task->cpus_allowed));
 368         seq_printf(m, "Cpus_allowed_list:\t%*pbl\n",
 369                    cpumask_pr_args(&task->cpus_allowed));
 370 }
 371
 372 int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
 373                         struct pid *pid, struct task_struct *task)
 374 {
 375         struct mm_struct *mm = get_task_mm(task);
 376
 377         task_name(m, task);
 378         task_state(m, ns, pid, task);
 379
 380         if (mm) {
 381                 task_mem(m, mm);
 382                 mmput(mm);
 383         }
 384         task_sig(m, task);
 385         task_cap(m, task);
 386         task_seccomp(m, task);
 387         task_cpus_allowed(m, task);
 388         cpuset_task_status_allowed(m, task);
 389         task_context_switch_counts(m, task);
 390         return 0;
 391 }
 392
 393 static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
 394                         struct pid *pid, struct task_struct *task, int whole)
 395 {
 396         unsigned long vsize, eip, esp, wchan = 0;
 397         int priority, nice;
 398         int tty_pgrp = -1, tty_nr = 0;
 399         sigset_t sigign, sigcatch;
 400         char state;
 401         pid_t ppid = 0, pgid = -1, sid = -1;
 402         int num_threads = 0;
 403         int permitted;
 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         u64 cutime, cstime, utime, stime;
 409         u64 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         permitted = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS | PTRACE_MODE_NOAUDIT);
 417         mm = get_task_mm(task);
 418         if (mm) {
 419                 vsize = task_vsize(mm);
 420                 /*
 421                  * esp and eip are intentionally zeroed out.  There is no
 422                  * non-racy way to read them without freezing the task.
 423                  * Programs that need reliable values can use ptrace(2).
 424                  */
 425         }
 426
 427         get_task_comm(tcomm, task);
 428
 429         sigemptyset(&sigign);
 430         sigemptyset(&sigcatch);
 431         cutime = cstime = utime = stime = 0;
 432         cgtime = gtime = 0;
 433
 434         if (lock_task_sighand(task, &flags)) {
 435                 struct signal_struct *sig = task->signal;
 436
 437                 if (sig->tty) {
 438                         struct pid *pgrp = tty_get_pgrp(sig->tty);
 439                         tty_pgrp = pid_nr_ns(pgrp, ns);
 440                         put_pid(pgrp);
 441                         tty_nr = new_encode_dev(tty_devnum(sig->tty));
 442                 }
 443
 444                 num_threads = get_nr_threads(task);
 445                 collect_sigign_sigcatch(task, &sigign, &sigcatch);
 446
 447                 cmin_flt = sig->cmin_flt;
 448                 cmaj_flt = sig->cmaj_flt;
 449                 cutime = sig->cutime;
 450                 cstime = sig->cstime;
 451                 cgtime = sig->cgtime;
 452                 rsslim = ACCESS_ONCE(sig->rlim[RLIMIT_RSS].rlim_cur);
 453
 454                 /* add up live thread stats at the group level */
 455                 if (whole) {
 456                         struct task_struct *t = task;
 457                         do {
 458                                 min_flt += t->min_flt;
 459                                 maj_flt += t->maj_flt;
 460                                 gtime += task_gtime(t);
 461                         } while_each_thread(task, t);
 462
 463                         min_flt += sig->min_flt;
 464                         maj_flt += sig->maj_flt;
 465                         thread_group_cputime_adjusted(task, &utime, &stime);
 466                         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 (permitted && (!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                 task_cputime_adjusted(task, &utime, &stime);
 482                 gtime = task_gtime(task);
 483         }
 484
 485         /* scale priority and nice values from timeslices to -20..20 */
 486         /* to make it look like a "normal" Unix priority/nice value  */
 487         priority = task_prio(task);
 488         nice = task_nice(task);
 489
 490         /* convert nsec -> ticks */
 491         start_time = nsec_to_clock_t(task->real_start_time);
 492
 493         seq_printf(m, "%d (%s) %c", pid_nr_ns(pid, ns), tcomm, state);
 494         seq_put_decimal_ll(m, " ", ppid);
 495         seq_put_decimal_ll(m, " ", pgid);
 496         seq_put_decimal_ll(m, " ", sid);
 497         seq_put_decimal_ll(m, " ", tty_nr);
 498         seq_put_decimal_ll(m, " ", tty_pgrp);
 499         seq_put_decimal_ull(m, " ", task->flags);
 500         seq_put_decimal_ull(m, " ", min_flt);
 501         seq_put_decimal_ull(m, " ", cmin_flt);
 502         seq_put_decimal_ull(m, " ", maj_flt);
 503         seq_put_decimal_ull(m, " ", cmaj_flt);
 504         seq_put_decimal_ull(m, " ", nsec_to_clock_t(utime));
 505         seq_put_decimal_ull(m, " ", nsec_to_clock_t(stime));
 506         seq_put_decimal_ll(m, " ", nsec_to_clock_t(cutime));
 507         seq_put_decimal_ll(m, " ", nsec_to_clock_t(cstime));
 508         seq_put_decimal_ll(m, " ", priority);
 509         seq_put_decimal_ll(m, " ", nice);
 510         seq_put_decimal_ll(m, " ", num_threads);
 511         seq_put_decimal_ull(m, " ", 0);
 512         seq_put_decimal_ull(m, " ", start_time);
 513         seq_put_decimal_ull(m, " ", vsize);
 514         seq_put_decimal_ull(m, " ", mm ? get_mm_rss(mm) : 0);
 515         seq_put_decimal_ull(m, " ", rsslim);
 516         seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->start_code : 1) : 0);
 517         seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->end_code : 1) : 0);
 518         seq_put_decimal_ull(m, " ", (permitted && mm) ? mm->start_stack : 0);
 519         seq_put_decimal_ull(m, " ", esp);
 520         seq_put_decimal_ull(m, " ", eip);
 521         /* The signal information here is obsolete.
 522          * It must be decimal for Linux 2.0 compatibility.
 523          * Use /proc/#/status for real-time signals.
 524          */
 525         seq_put_decimal_ull(m, " ", task->pending.signal.sig[0] & 0x7fffffffUL);
 526         seq_put_decimal_ull(m, " ", task->blocked.sig[0] & 0x7fffffffUL);
 527         seq_put_decimal_ull(m, " ", sigign.sig[0] & 0x7fffffffUL);
 528         seq_put_decimal_ull(m, " ", sigcatch.sig[0] & 0x7fffffffUL);
 529
 530         /*
 531          * We used to output the absolute kernel address, but that's an
 532          * information leak - so instead we show a 0/1 flag here, to signal
 533          * to user-space whether there's a wchan field in /proc/PID/wchan.
 534          *
 535          * This works with older implementations of procps as well.
 536          */
 537         if (wchan)
 538                 seq_puts(m, " 1");
 539         else
 540                 seq_puts(m, " 0");
 541
 542         seq_put_decimal_ull(m, " ", 0);
 543         seq_put_decimal_ull(m, " ", 0);
 544         seq_put_decimal_ll(m, " ", task->exit_signal);
 545         seq_put_decimal_ll(m, " ", task_cpu(task));
 546         seq_put_decimal_ull(m, " ", task->rt_priority);
 547         seq_put_decimal_ull(m, " ", task->policy);
 548         seq_put_decimal_ull(m, " ", delayacct_blkio_ticks(task));
 549         seq_put_decimal_ull(m, " ", nsec_to_clock_t(gtime));
 550         seq_put_decimal_ll(m, " ", nsec_to_clock_t(cgtime));
 551
 552         if (mm && permitted) {
 553                 seq_put_decimal_ull(m, " ", mm->start_data);
 554                 seq_put_decimal_ull(m, " ", mm->end_data);
 555                 seq_put_decimal_ull(m, " ", mm->start_brk);
 556                 seq_put_decimal_ull(m, " ", mm->arg_start);
 557                 seq_put_decimal_ull(m, " ", mm->arg_end);
 558                 seq_put_decimal_ull(m, " ", mm->env_start);
 559                 seq_put_decimal_ull(m, " ", mm->env_end);
 560         } else
 561                 seq_puts(m, " 0 0 0 0 0 0 0");
 562
 563         if (permitted)
 564                 seq_put_decimal_ll(m, " ", task->exit_code);
 565         else
 566                 seq_puts(m, " 0");
 567
 568         seq_putc(m, '\n');
 569         if (mm)
 570                 mmput(mm);
 571         return 0;
 572 }
 573
 574 int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,
 575                         struct pid *pid, struct task_struct *task)
 576 {
 577         return do_task_stat(m, ns, pid, task, 0);
 578 }
 579
 580 int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,
 581                         struct pid *pid, struct task_struct *task)
 582 {
 583         return do_task_stat(m, ns, pid, task, 1);
 584 }
 585
 586 int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,
 587                         struct pid *pid, struct task_struct *task)
 588 {
 589         unsigned long size = 0, resident = 0, shared = 0, text = 0, data = 0;
 590         struct mm_struct *mm = get_task_mm(task);
 591
 592         if (mm) {
 593                 size = task_statm(mm, &shared, &text, &data, &resident);
 594                 mmput(mm);
 595         }
 596         /*
 597          * For quick read, open code by putting numbers directly
 598          * expected format is
 599          * seq_printf(m, "%lu %lu %lu %lu 0 %lu 0\n",
 600          *               size, resident, shared, text, data);
 601          */
 602         seq_put_decimal_ull(m, "", size);
 603         seq_put_decimal_ull(m, " ", resident);
 604         seq_put_decimal_ull(m, " ", shared);
 605         seq_put_decimal_ull(m, " ", text);
 606         seq_put_decimal_ull(m, " ", 0);
 607         seq_put_decimal_ull(m, " ", data);
 608         seq_put_decimal_ull(m, " ", 0);
 609         seq_putc(m, '\n');
 610
 611         return 0;
 612 }
 613
 614 #ifdef CONFIG_PROC_CHILDREN
 615 static struct pid *
 616 get_children_pid(struct inode *inode, struct pid *pid_prev, loff_t pos)
 617 {
 618         struct task_struct *start, *task;
 619         struct pid *pid = NULL;
 620
 621         read_lock(&tasklist_lock);
 622
 623         start = pid_task(proc_pid(inode), PIDTYPE_PID);
 624         if (!start)
 625                 goto out;
 626
 627         /*
 628          * Lets try to continue searching first, this gives
 629          * us significant speedup on children-rich processes.
 630          */
 631         if (pid_prev) {
 632                 task = pid_task(pid_prev, PIDTYPE_PID);
 633                 if (task && task->real_parent == start &&
 634                     !(list_empty(&task->sibling))) {
 635                         if (list_is_last(&task->sibling, &start->children))
 636                                 goto out;
 637                         task = list_first_entry(&task->sibling,
 638                                                 struct task_struct, sibling);
 639                         pid = get_pid(task_pid(task));
 640                         goto out;
 641                 }
 642         }
 643
 644         /*
 645          * Slow search case.
 646          *
 647          * We might miss some children here if children
 648          * are exited while we were not holding the lock,
 649          * but it was never promised to be accurate that
 650          * much.
 651          *
 652          * "Just suppose that the parent sleeps, but N children
 653          *  exit after we printed their tids. Now the slow paths
 654          *  skips N extra children, we miss N tasks." (c)
 655          *
 656          * So one need to stop or freeze the leader and all
 657          * its children to get a precise result.
 658          */
 659         list_for_each_entry(task, &start->children, sibling) {
 660                 if (pos-- == 0) {
 661                         pid = get_pid(task_pid(task));
 662                         break;
 663                 }
 664         }
 665
 666 out:
 667         read_unlock(&tasklist_lock);
 668         return pid;
 669 }
 670
 671 static int children_seq_show(struct seq_file *seq, void *v)
 672 {
 673         struct inode *inode = seq->private;
 674         pid_t pid;
 675
 676         pid = pid_nr_ns(v, inode->i_sb->s_fs_info);
 677         seq_printf(seq, "%d ", pid);
 678
 679         return 0;
 680 }
 681
 682 static void *children_seq_start(struct seq_file *seq, loff_t *pos)
 683 {
 684         return get_children_pid(seq->private, NULL, *pos);
 685 }
 686
 687 static void *children_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 688 {
 689         struct pid *pid;
 690
 691         pid = get_children_pid(seq->private, v, *pos + 1);
 692         put_pid(v);
 693
 694         ++*pos;
 695         return pid;
 696 }
 697
 698 static void children_seq_stop(struct seq_file *seq, void *v)
 699 {
 700         put_pid(v);
 701 }
 702
 703 static const struct seq_operations children_seq_ops = {
 704         .start  = children_seq_start,
 705         .next   = children_seq_next,
 706         .stop   = children_seq_stop,
 707         .show   = children_seq_show,
 708 };
 709
 710 static int children_seq_open(struct inode *inode, struct file *file)
 711 {
 712         struct seq_file *m;
 713         int ret;
 714
 715         ret = seq_open(file, &children_seq_ops);
 716         if (ret)
 717                 return ret;
 718
 719         m = file->private_data;
 720         m->private = inode;
 721
 722         return ret;
 723 }
 724
 725 int children_seq_release(struct inode *inode, struct file *file)
 726 {
 727         seq_release(inode, file);
 728         return 0;
 729 }
 730
 731 const struct file_operations proc_tid_children_operations = {
 732         .open    = children_seq_open,
 733         .read    = seq_read,
 734         .llseek  = seq_lseek,
 735         .release = children_seq_release,
 736 };
 737 #endif /* CONFIG_PROC_CHILDREN */