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_stack.h>
  66 #include <linux/sched/task.h>
  67 #include <linux/sched/cputime.h>
  68 #include <linux/proc_fs.h>
  69 #include <linux/ioport.h>
  70 #include <linux/uaccess.h>
  71 #include <linux/io.h>
  72 #include <linux/mm.h>
  73 #include <linux/hugetlb.h>
  74 #include <linux/pagemap.h>
  75 #include <linux/swap.h>
  76 #include <linux/smp.h>
  77 #include <linux/signal.h>
  78 #include <linux/highmem.h>
  79 #include <linux/file.h>
  80 #include <linux/fdtable.h>
  81 #include <linux/times.h>
  82 #include <linux/cpuset.h>
  83 #include <linux/rcupdate.h>
  84 #include <linux/delayacct.h>
  85 #include <linux/seq_file.h>
  86 #include <linux/pid_namespace.h>
  87 #include <linux/ptrace.h>
  88 #include <linux/tracehook.h>
  89 #include <linux/string_helpers.h>
  90 #include <linux/user_namespace.h>
  91 #include <linux/fs_struct.h>
  92
  93 #include <asm/pgtable.h>
  94 #include <asm/processor.h>
  95 #include "internal.h"
  96
  97 static inline void task_name(struct seq_file *m, struct task_struct *p)
  98 {
  99         char *buf;
 100         size_t size;
 101         char tcomm[sizeof(p->comm)];
 102         int ret;
 103
 104         get_task_comm(tcomm, p);
 105
 106         seq_puts(m, "Name:\t");
 107
 108         size = seq_get_buf(m, &buf);
 109         ret = string_escape_str(tcomm, buf, size, ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\");
 110         seq_commit(m, ret < size ? ret : -1);
 111
 112         seq_putc(m, '\n');
 113 }
 114
 115 /*
 116  * The task state array is a strange "bitmap" of
 117  * reasons to sleep. Thus "running" is zero, and
 118  * you can test for combinations of others with
 119  * simple bit tests.
 120  */
 121 static const char * const task_state_array[] = {
 122         "R (running)",          /*   0 */
 123         "S (sleeping)",         /*   1 */
 124         "D (disk sleep)",       /*   2 */
 125         "T (stopped)",          /*   4 */
 126         "t (tracing stop)",     /*   8 */
 127         "X (dead)",             /*  16 */
 128         "Z (zombie)",           /*  32 */
 129 };
 130
 131 static inline const char *get_task_state(struct task_struct *tsk)
 132 {
 133         unsigned int state = (tsk->state | tsk->exit_state) & TASK_REPORT;
 134
 135         /*
 136          * Parked tasks do not run; they sit in __kthread_parkme().
 137          * Without this check, we would report them as running, which is
 138          * clearly wrong, so we report them as sleeping instead.
 139          */
 140         if (tsk->state == TASK_PARKED)
 141                 state = TASK_INTERRUPTIBLE;
 142
 143         BUILD_BUG_ON(1 + ilog2(TASK_REPORT) != ARRAY_SIZE(task_state_array)-1);
 144
 145         return task_state_array[fls(state)];
 146 }
 147
 148 static inline int get_task_umask(struct task_struct *tsk)
 149 {
 150         struct fs_struct *fs;
 151         int umask = -ENOENT;
 152
 153         task_lock(tsk);
 154         fs = tsk->fs;
 155         if (fs)
 156                 umask = fs->umask;
 157         task_unlock(tsk);
 158         return umask;
 159 }
 160
 161 static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
 162                                 struct pid *pid, struct task_struct *p)
 163 {
 164         struct user_namespace *user_ns = seq_user_ns(m);
 165         struct group_info *group_info;
 166         int g, umask;
 167         struct task_struct *tracer;
 168         const struct cred *cred;
 169         pid_t ppid, tpid = 0, tgid, ngid;
 170         unsigned int max_fds = 0;
 171
 172         rcu_read_lock();
 173         ppid = pid_alive(p) ?
 174                 task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0;
 175
 176         tracer = ptrace_parent(p);
 177         if (tracer)
 178                 tpid = task_pid_nr_ns(tracer, ns);
 179
 180         tgid = task_tgid_nr_ns(p, ns);
 181         ngid = task_numa_group_id(p);
 182         cred = get_task_cred(p);
 183
 184         umask = get_task_umask(p);
 185         if (umask >= 0)
 186                 seq_printf(m, "Umask:\t%#04o\n", umask);
 187
 188         task_lock(p);
 189         if (p->files)
 190                 max_fds = files_fdtable(p->files)->max_fds;
 191         task_unlock(p);
 192         rcu_read_unlock();
 193
 194         seq_printf(m, "State:\t%s", get_task_state(p));
 195
 196         seq_put_decimal_ull(m, "\nTgid:\t", tgid);
 197         seq_put_decimal_ull(m, "\nNgid:\t", ngid);
 198         seq_put_decimal_ull(m, "\nPid:\t", pid_nr_ns(pid, ns));
 199         seq_put_decimal_ull(m, "\nPPid:\t", ppid);
 200         seq_put_decimal_ull(m, "\nTracerPid:\t", tpid);
 201         seq_put_decimal_ull(m, "\nUid:\t", from_kuid_munged(user_ns, cred->uid));
 202         seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->euid));
 203         seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->suid));
 204         seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->fsuid));
 205         seq_put_decimal_ull(m, "\nGid:\t", from_kgid_munged(user_ns, cred->gid));
 206         seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->egid));
 207         seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->sgid));
 208         seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->fsgid));
 209         seq_put_decimal_ull(m, "\nFDSize:\t", max_fds);
 210
 211         seq_puts(m, "\nGroups:\t");
 212         group_info = cred->group_info;
 213         for (g = 0; g < group_info->ngroups; g++)
 214                 seq_put_decimal_ull(m, g ? " " : "",
 215                                 from_kgid_munged(user_ns, group_info->gid[g]));
 216         put_cred(cred);
 217         /* Trailing space shouldn't have been added in the first place. */
 218         seq_putc(m, ' ');
 219
 220 #ifdef CONFIG_PID_NS
 221         seq_puts(m, "\nNStgid:");
 222         for (g = ns->level; g <= pid->level; g++)
 223                 seq_put_decimal_ull(m, "\t", task_tgid_nr_ns(p, pid->numbers[g].ns));
 224         seq_puts(m, "\nNSpid:");
 225         for (g = ns->level; g <= pid->level; g++)
 226                 seq_put_decimal_ull(m, "\t", task_pid_nr_ns(p, pid->numbers[g].ns));
 227         seq_puts(m, "\nNSpgid:");
 228         for (g = ns->level; g <= pid->level; g++)
 229                 seq_put_decimal_ull(m, "\t", task_pgrp_nr_ns(p, pid->numbers[g].ns));
 230         seq_puts(m, "\nNSsid:");
 231         for (g = ns->level; g <= pid->level; g++)
 232                 seq_put_decimal_ull(m, "\t", task_session_nr_ns(p, pid->numbers[g].ns));
 233 #endif
 234         seq_putc(m, '\n');
 235 }
 236
 237 void render_sigset_t(struct seq_file *m, const char *header,
 238                                 sigset_t *set)
 239 {
 240         int i;
 241
 242         seq_puts(m, header);
 243
 244         i = _NSIG;
 245         do {
 246                 int x = 0;
 247
 248                 i -= 4;
 249                 if (sigismember(set, i+1)) x |= 1;
 250                 if (sigismember(set, i+2)) x |= 2;
 251                 if (sigismember(set, i+3)) x |= 4;
 252                 if (sigismember(set, i+4)) x |= 8;
 253                 seq_putc(m, hex_asc[x]);
 254         } while (i >= 4);
 255
 256         seq_putc(m, '\n');
 257 }
 258
 259 static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *ign,
 260                                     sigset_t *catch)
 261 {
 262         struct k_sigaction *k;
 263         int i;
 264
 265         k = p->sighand->action;
 266         for (i = 1; i <= _NSIG; ++i, ++k) {
 267                 if (k->sa.sa_handler == SIG_IGN)
 268                         sigaddset(ign, i);
 269                 else if (k->sa.sa_handler != SIG_DFL)
 270                         sigaddset(catch, i);
 271         }
 272 }
 273
 274 static inline void task_sig(struct seq_file *m, struct task_struct *p)
 275 {
 276         unsigned long flags;
 277         sigset_t pending, shpending, blocked, ignored, caught;
 278         int num_threads = 0;
 279         unsigned long qsize = 0;
 280         unsigned long qlim = 0;
 281
 282         sigemptyset(&pending);
 283         sigemptyset(&shpending);
 284         sigemptyset(&blocked);
 285         sigemptyset(&ignored);
 286         sigemptyset(&caught);
 287
 288         if (lock_task_sighand(p, &flags)) {
 289                 pending = p->pending.signal;
 290                 shpending = p->signal->shared_pending.signal;
 291                 blocked = p->blocked;
 292                 collect_sigign_sigcatch(p, &ignored, &caught);
 293                 num_threads = get_nr_threads(p);
 294                 rcu_read_lock();  /* FIXME: is this correct? */
 295                 qsize = atomic_read(&__task_cred(p)->user->sigpending);
 296                 rcu_read_unlock();
 297                 qlim = task_rlimit(p, RLIMIT_SIGPENDING);
 298                 unlock_task_sighand(p, &flags);
 299         }
 300
 301         seq_put_decimal_ull(m, "Threads:\t", num_threads);
 302         seq_put_decimal_ull(m, "\nSigQ:\t", qsize);
 303         seq_put_decimal_ull(m, "/", qlim);
 304
 305         /* render them all */
 306         render_sigset_t(m, "\nSigPnd:\t", &pending);
 307         render_sigset_t(m, "ShdPnd:\t", &shpending);
 308         render_sigset_t(m, "SigBlk:\t", &blocked);
 309         render_sigset_t(m, "SigIgn:\t", &ignored);
 310         render_sigset_t(m, "SigCgt:\t", &caught);
 311 }
 312
 313 static void render_cap_t(struct seq_file *m, const char *header,
 314                         kernel_cap_t *a)
 315 {
 316         unsigned __capi;
 317
 318         seq_puts(m, header);
 319         CAP_FOR_EACH_U32(__capi) {
 320                 seq_printf(m, "%08x",
 321                            a->cap[CAP_LAST_U32 - __capi]);
 322         }
 323         seq_putc(m, '\n');
 324 }
 325
 326 static inline void task_cap(struct seq_file *m, struct task_struct *p)
 327 {
 328         const struct cred *cred;
 329         kernel_cap_t cap_inheritable, cap_permitted, cap_effective,
 330                         cap_bset, cap_ambient;
 331
 332         rcu_read_lock();
 333         cred = __task_cred(p);
 334         cap_inheritable = cred->cap_inheritable;
 335         cap_permitted   = cred->cap_permitted;
 336         cap_effective   = cred->cap_effective;
 337         cap_bset        = cred->cap_bset;
 338         cap_ambient     = cred->cap_ambient;
 339         rcu_read_unlock();
 340
 341         render_cap_t(m, "CapInh:\t", &cap_inheritable);
 342         render_cap_t(m, "CapPrm:\t", &cap_permitted);
 343         render_cap_t(m, "CapEff:\t", &cap_effective);
 344         render_cap_t(m, "CapBnd:\t", &cap_bset);
 345         render_cap_t(m, "CapAmb:\t", &cap_ambient);
 346 }
 347
 348 static inline void task_seccomp(struct seq_file *m, struct task_struct *p)
 349 {
 350         seq_put_decimal_ull(m, "NoNewPrivs:\t", task_no_new_privs(p));
 351 #ifdef CONFIG_SECCOMP
 352         seq_put_decimal_ull(m, "\nSeccomp:\t", p->seccomp.mode);
 353 #endif
 354         seq_putc(m, '\n');
 355 }
 356
 357 static inline void task_context_switch_counts(struct seq_file *m,
 358                                                 struct task_struct *p)
 359 {
 360         seq_put_decimal_ull(m, "voluntary_ctxt_switches:\t", p->nvcsw);
 361         seq_put_decimal_ull(m, "\nnonvoluntary_ctxt_switches:\t", p->nivcsw);
 362         seq_putc(m, '\n');
 363 }
 364
 365 static void task_cpus_allowed(struct seq_file *m, struct task_struct *task)
 366 {
 367         seq_printf(m, "Cpus_allowed:\t%*pb\n",
 368                    cpumask_pr_args(&task->cpus_allowed));
 369         seq_printf(m, "Cpus_allowed_list:\t%*pbl\n",
 370                    cpumask_pr_args(&task->cpus_allowed));
 371 }
 372
 373 int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
 374                         struct pid *pid, struct task_struct *task)
 375 {
 376         struct mm_struct *mm = get_task_mm(task);
 377
 378         task_name(m, task);
 379         task_state(m, ns, pid, task);
 380
 381         if (mm) {
 382                 task_mem(m, mm);
 383                 mmput(mm);
 384         }
 385         task_sig(m, task);
 386         task_cap(m, task);
 387         task_seccomp(m, task);
 388         task_cpus_allowed(m, task);
 389         cpuset_task_status_allowed(m, task);
 390         task_context_switch_counts(m, task);
 391         return 0;
 392 }
 393
 394 static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
 395                         struct pid *pid, struct task_struct *task, int whole)
 396 {
 397         unsigned long vsize, eip, esp, wchan = 0;
 398         int priority, nice;
 399         int tty_pgrp = -1, tty_nr = 0;
 400         sigset_t sigign, sigcatch;
 401         char state;
 402         pid_t ppid = 0, pgid = -1, sid = -1;
 403         int num_threads = 0;
 404         int permitted;
 405         struct mm_struct *mm;
 406         unsigned long long start_time;
 407         unsigned long cmin_flt = 0, cmaj_flt = 0;
 408         unsigned long  min_flt = 0,  maj_flt = 0;
 409         u64 cutime, cstime, utime, stime;
 410         u64 cgtime, gtime;
 411         unsigned long rsslim = 0;
 412         char tcomm[sizeof(task->comm)];
 413         unsigned long flags;
 414
 415         state = *get_task_state(task);
 416         vsize = eip = esp = 0;
 417         permitted = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS | PTRACE_MODE_NOAUDIT);
 418         mm = get_task_mm(task);
 419         if (mm) {
 420                 vsize = task_vsize(mm);
 421                 /*
 422                  * esp and eip are intentionally zeroed out.  There is no
 423                  * non-racy way to read them without freezing the task.
 424                  * Programs that need reliable values can use ptrace(2).
 425                  *
 426                  * The only exception is if the task is core dumping because
 427                  * a program is not able to use ptrace(2) in that case. It is
 428                  * safe because the task has stopped executing permanently.
 429                  */
 430                 if (permitted && (task->flags & PF_DUMPCORE)) {
 431                         eip = KSTK_EIP(task);
 432                         esp = KSTK_ESP(task);
 433                 }
 434         }
 435
 436         get_task_comm(tcomm, task);
 437
 438         sigemptyset(&sigign);
 439         sigemptyset(&sigcatch);
 440         cutime = cstime = utime = stime = 0;
 441         cgtime = gtime = 0;
 442
 443         if (lock_task_sighand(task, &flags)) {
 444                 struct signal_struct *sig = task->signal;
 445
 446                 if (sig->tty) {
 447                         struct pid *pgrp = tty_get_pgrp(sig->tty);
 448                         tty_pgrp = pid_nr_ns(pgrp, ns);
 449                         put_pid(pgrp);
 450                         tty_nr = new_encode_dev(tty_devnum(sig->tty));
 451                 }
 452
 453                 num_threads = get_nr_threads(task);
 454                 collect_sigign_sigcatch(task, &sigign, &sigcatch);
 455
 456                 cmin_flt = sig->cmin_flt;
 457                 cmaj_flt = sig->cmaj_flt;
 458                 cutime = sig->cutime;
 459                 cstime = sig->cstime;
 460                 cgtime = sig->cgtime;
 461                 rsslim = ACCESS_ONCE(sig->rlim[RLIMIT_RSS].rlim_cur);
 462
 463                 /* add up live thread stats at the group level */
 464                 if (whole) {
 465                         struct task_struct *t = task;
 466                         do {
 467                                 min_flt += t->min_flt;
 468                                 maj_flt += t->maj_flt;
 469                                 gtime += task_gtime(t);
 470                         } while_each_thread(task, t);
 471
 472                         min_flt += sig->min_flt;
 473                         maj_flt += sig->maj_flt;
 474                         thread_group_cputime_adjusted(task, &utime, &stime);
 475                         gtime += sig->gtime;
 476                 }
 477
 478                 sid = task_session_nr_ns(task, ns);
 479                 ppid = task_tgid_nr_ns(task->real_parent, ns);
 480                 pgid = task_pgrp_nr_ns(task, ns);
 481
 482                 unlock_task_sighand(task, &flags);
 483         }
 484
 485         if (permitted && (!whole || num_threads < 2))
 486                 wchan = get_wchan(task);
 487         if (!whole) {
 488                 min_flt = task->min_flt;
 489                 maj_flt = task->maj_flt;
 490                 task_cputime_adjusted(task, &utime, &stime);
 491                 gtime = task_gtime(task);
 492         }
 493
 494         /* scale priority and nice values from timeslices to -20..20 */
 495         /* to make it look like a "normal" Unix priority/nice value  */
 496         priority = task_prio(task);
 497         nice = task_nice(task);
 498
 499         /* convert nsec -> ticks */
 500         start_time = nsec_to_clock_t(task->real_start_time);
 501
 502         seq_printf(m, "%d (%s) %c", pid_nr_ns(pid, ns), tcomm, state);
 503         seq_put_decimal_ll(m, " ", ppid);
 504         seq_put_decimal_ll(m, " ", pgid);
 505         seq_put_decimal_ll(m, " ", sid);
 506         seq_put_decimal_ll(m, " ", tty_nr);
 507         seq_put_decimal_ll(m, " ", tty_pgrp);
 508         seq_put_decimal_ull(m, " ", task->flags);
 509         seq_put_decimal_ull(m, " ", min_flt);
 510         seq_put_decimal_ull(m, " ", cmin_flt);
 511         seq_put_decimal_ull(m, " ", maj_flt);
 512         seq_put_decimal_ull(m, " ", cmaj_flt);
 513         seq_put_decimal_ull(m, " ", nsec_to_clock_t(utime));
 514         seq_put_decimal_ull(m, " ", nsec_to_clock_t(stime));
 515         seq_put_decimal_ll(m, " ", nsec_to_clock_t(cutime));
 516         seq_put_decimal_ll(m, " ", nsec_to_clock_t(cstime));
 517         seq_put_decimal_ll(m, " ", priority);
 518         seq_put_decimal_ll(m, " ", nice);
 519         seq_put_decimal_ll(m, " ", num_threads);
 520         seq_put_decimal_ull(m, " ", 0);
 521         seq_put_decimal_ull(m, " ", start_time);
 522         seq_put_decimal_ull(m, " ", vsize);
 523         seq_put_decimal_ull(m, " ", mm ? get_mm_rss(mm) : 0);
 524         seq_put_decimal_ull(m, " ", rsslim);
 525         seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->start_code : 1) : 0);
 526         seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->end_code : 1) : 0);
 527         seq_put_decimal_ull(m, " ", (permitted && mm) ? mm->start_stack : 0);
 528         seq_put_decimal_ull(m, " ", esp);
 529         seq_put_decimal_ull(m, " ", eip);
 530         /* The signal information here is obsolete.
 531          * It must be decimal for Linux 2.0 compatibility.
 532          * Use /proc/#/status for real-time signals.
 533          */
 534         seq_put_decimal_ull(m, " ", task->pending.signal.sig[0] & 0x7fffffffUL);
 535         seq_put_decimal_ull(m, " ", task->blocked.sig[0] & 0x7fffffffUL);
 536         seq_put_decimal_ull(m, " ", sigign.sig[0] & 0x7fffffffUL);
 537         seq_put_decimal_ull(m, " ", sigcatch.sig[0] & 0x7fffffffUL);
 538
 539         /*
 540          * We used to output the absolute kernel address, but that's an
 541          * information leak - so instead we show a 0/1 flag here, to signal
 542          * to user-space whether there's a wchan field in /proc/PID/wchan.
 543          *
 544          * This works with older implementations of procps as well.
 545          */
 546         if (wchan)
 547                 seq_puts(m, " 1");
 548         else
 549                 seq_puts(m, " 0");
 550
 551         seq_put_decimal_ull(m, " ", 0);
 552         seq_put_decimal_ull(m, " ", 0);
 553         seq_put_decimal_ll(m, " ", task->exit_signal);
 554         seq_put_decimal_ll(m, " ", task_cpu(task));
 555         seq_put_decimal_ull(m, " ", task->rt_priority);
 556         seq_put_decimal_ull(m, " ", task->policy);
 557         seq_put_decimal_ull(m, " ", delayacct_blkio_ticks(task));
 558         seq_put_decimal_ull(m, " ", nsec_to_clock_t(gtime));
 559         seq_put_decimal_ll(m, " ", nsec_to_clock_t(cgtime));
 560
 561         if (mm && permitted) {
 562                 seq_put_decimal_ull(m, " ", mm->start_data);
 563                 seq_put_decimal_ull(m, " ", mm->end_data);
 564                 seq_put_decimal_ull(m, " ", mm->start_brk);
 565                 seq_put_decimal_ull(m, " ", mm->arg_start);
 566                 seq_put_decimal_ull(m, " ", mm->arg_end);
 567                 seq_put_decimal_ull(m, " ", mm->env_start);
 568                 seq_put_decimal_ull(m, " ", mm->env_end);
 569         } else
 570                 seq_puts(m, " 0 0 0 0 0 0 0");
 571
 572         if (permitted)
 573                 seq_put_decimal_ll(m, " ", task->exit_code);
 574         else
 575                 seq_puts(m, " 0");
 576
 577         seq_putc(m, '\n');
 578         if (mm)
 579                 mmput(mm);
 580         return 0;
 581 }
 582
 583 int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,
 584                         struct pid *pid, struct task_struct *task)
 585 {
 586         return do_task_stat(m, ns, pid, task, 0);
 587 }
 588
 589 int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,
 590                         struct pid *pid, struct task_struct *task)
 591 {
 592         return do_task_stat(m, ns, pid, task, 1);
 593 }
 594
 595 int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,
 596                         struct pid *pid, struct task_struct *task)
 597 {
 598         unsigned long size = 0, resident = 0, shared = 0, text = 0, data = 0;
 599         struct mm_struct *mm = get_task_mm(task);
 600
 601         if (mm) {
 602                 size = task_statm(mm, &shared, &text, &data, &resident);
 603                 mmput(mm);
 604         }
 605         /*
 606          * For quick read, open code by putting numbers directly
 607          * expected format is
 608          * seq_printf(m, "%lu %lu %lu %lu 0 %lu 0\n",
 609          *               size, resident, shared, text, data);
 610          */
 611         seq_put_decimal_ull(m, "", size);
 612         seq_put_decimal_ull(m, " ", resident);
 613         seq_put_decimal_ull(m, " ", shared);
 614         seq_put_decimal_ull(m, " ", text);
 615         seq_put_decimal_ull(m, " ", 0);
 616         seq_put_decimal_ull(m, " ", data);
 617         seq_put_decimal_ull(m, " ", 0);
 618         seq_putc(m, '\n');
 619
 620         return 0;
 621 }
 622
 623 #ifdef CONFIG_PROC_CHILDREN
 624 static struct pid *
 625 get_children_pid(struct inode *inode, struct pid *pid_prev, loff_t pos)
 626 {
 627         struct task_struct *start, *task;
 628         struct pid *pid = NULL;
 629
 630         read_lock(&tasklist_lock);
 631
 632         start = pid_task(proc_pid(inode), PIDTYPE_PID);
 633         if (!start)
 634                 goto out;
 635
 636         /*
 637          * Lets try to continue searching first, this gives
 638          * us significant speedup on children-rich processes.
 639          */
 640         if (pid_prev) {
 641                 task = pid_task(pid_prev, PIDTYPE_PID);
 642                 if (task && task->real_parent == start &&
 643                     !(list_empty(&task->sibling))) {
 644                         if (list_is_last(&task->sibling, &start->children))
 645                                 goto out;
 646                         task = list_first_entry(&task->sibling,
 647                                                 struct task_struct, sibling);
 648                         pid = get_pid(task_pid(task));
 649                         goto out;
 650                 }
 651         }
 652
 653         /*
 654          * Slow search case.
 655          *
 656          * We might miss some children here if children
 657          * are exited while we were not holding the lock,
 658          * but it was never promised to be accurate that
 659          * much.
 660          *
 661          * "Just suppose that the parent sleeps, but N children
 662          *  exit after we printed their tids. Now the slow paths
 663          *  skips N extra children, we miss N tasks." (c)
 664          *
 665          * So one need to stop or freeze the leader and all
 666          * its children to get a precise result.
 667          */
 668         list_for_each_entry(task, &start->children, sibling) {
 669                 if (pos-- == 0) {
 670                         pid = get_pid(task_pid(task));
 671                         break;
 672                 }
 673         }
 674
 675 out:
 676         read_unlock(&tasklist_lock);
 677         return pid;
 678 }
 679
 680 static int children_seq_show(struct seq_file *seq, void *v)
 681 {
 682         struct inode *inode = seq->private;
 683         pid_t pid;
 684
 685         pid = pid_nr_ns(v, inode->i_sb->s_fs_info);
 686         seq_printf(seq, "%d ", pid);
 687
 688         return 0;
 689 }
 690
 691 static void *children_seq_start(struct seq_file *seq, loff_t *pos)
 692 {
 693         return get_children_pid(seq->private, NULL, *pos);
 694 }
 695
 696 static void *children_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 697 {
 698         struct pid *pid;
 699
 700         pid = get_children_pid(seq->private, v, *pos + 1);
 701         put_pid(v);
 702
 703         ++*pos;
 704         return pid;
 705 }
 706
 707 static void children_seq_stop(struct seq_file *seq, void *v)
 708 {
 709         put_pid(v);
 710 }
 711
 712 static const struct seq_operations children_seq_ops = {
 713         .start  = children_seq_start,
 714         .next   = children_seq_next,
 715         .stop   = children_seq_stop,
 716         .show   = children_seq_show,
 717 };
 718
 719 static int children_seq_open(struct inode *inode, struct file *file)
 720 {
 721         struct seq_file *m;
 722         int ret;
 723
 724         ret = seq_open(file, &children_seq_ops);
 725         if (ret)
 726                 return ret;
 727
 728         m = file->private_data;
 729         m->private = inode;
 730
 731         return ret;
 732 }
 733
 734 int children_seq_release(struct inode *inode, struct file *file)
 735 {
 736         seq_release(inode, file);
 737         return 0;
 738 }
 739
 740 const struct file_operations proc_tid_children_operations = {
 741         .open    = children_seq_open,
 742         .read    = seq_read,
 743         .llseek  = seq_lseek,
 744         .release = children_seq_release,
 745 };
 746 #endif /* CONFIG_PROC_CHILDREN */