1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/proc/array.c 4 * 5 * Copyright (C) 1992 by Linus Torvalds 6 * based on ideas by Darren Senn 7 * 8 * Fixes: 9 * Michael. K. Johnson: stat,statm extensions. 10 * <johnsonm@stolaf.edu> 11 * 12 * Pauline Middelink : Made cmdline,envline only break at '\0's, to 13 * make sure SET_PROCTITLE works. Also removed 14 * bad '!' which forced address recalculation for 15 * EVERY character on the current page. 16 * <middelin@polyware.iaf.nl> 17 * 18 * Danny ter Haar : added cpuinfo 19 * <dth@cistron.nl> 20 * 21 * Alessandro Rubini : profile extension. 22 * <rubini@ipvvis.unipv.it> 23 * 24 * Jeff Tranter : added BogoMips field to cpuinfo 25 * <Jeff_Tranter@Mitel.COM> 26 * 27 * Bruno Haible : remove 4K limit for the maps file 28 * <haible@ma2s2.mathematik.uni-karlsruhe.de> 29 * 30 * Yves Arrouye : remove removal of trailing spaces in get_array. 31 * <Yves.Arrouye@marin.fdn.fr> 32 * 33 * Jerome Forissier : added per-CPU time information to /proc/stat 34 * and /proc/<pid>/cpu extension 35 * <forissier@isia.cma.fr> 36 * - Incorporation and non-SMP safe operation 37 * of forissier patch in 2.1.78 by 38 * Hans Marcus <crowbar@concepts.nl> 39 * 40 * aeb@cwi.nl : /proc/partitions 41 * 42 * 43 * Alan Cox : security fixes. 44 * <alan@lxorguk.ukuu.org.uk> 45 * 46 * Al Viro : safe handling of mm_struct 47 * 48 * Gerhard Wichert : added BIGMEM support 49 * Siemens AG <Gerhard.Wichert@pdb.siemens.de> 50 * 51 * Al Viro & Jeff Garzik : moved most of the thing into base.c and 52 * : proc_misc.c. The rest may eventually go into 53 * : base.c too. 54 */ 55 56 #include <linux/types.h> 57 #include <linux/errno.h> 58 #include <linux/time.h> 59 #include <linux/kernel.h> 60 #include <linux/kernel_stat.h> 61 #include <linux/tty.h> 62 #include <linux/string.h> 63 #include <linux/mman.h> 64 #include <linux/sched/mm.h> 65 #include <linux/sched/numa_balancing.h> 66 #include <linux/sched/task_stack.h> 67 #include <linux/sched/task.h> 68 #include <linux/sched/cputime.h> 69 #include <linux/proc_fs.h> 70 #include <linux/ioport.h> 71 #include <linux/uaccess.h> 72 #include <linux/io.h> 73 #include <linux/mm.h> 74 #include <linux/hugetlb.h> 75 #include <linux/pagemap.h> 76 #include <linux/swap.h> 77 #include <linux/smp.h> 78 #include <linux/signal.h> 79 #include <linux/highmem.h> 80 #include <linux/file.h> 81 #include <linux/fdtable.h> 82 #include <linux/times.h> 83 #include <linux/cpuset.h> 84 #include <linux/rcupdate.h> 85 #include <linux/delayacct.h> 86 #include <linux/seq_file.h> 87 #include <linux/pid_namespace.h> 88 #include <linux/ptrace.h> 89 #include <linux/tracehook.h> 90 #include <linux/string_helpers.h> 91 #include <linux/user_namespace.h> 92 #include <linux/fs_struct.h> 93 94 #include <asm/pgtable.h> 95 #include <asm/processor.h> 96 #include "internal.h" 97 98 static inline void task_name(struct seq_file *m, struct task_struct *p) 99 { 100 char *buf; 101 size_t size; 102 char tcomm[sizeof(p->comm)]; 103 int ret; 104 105 get_task_comm(tcomm, p); 106 107 seq_puts(m, "Name:\t"); 108 109 size = seq_get_buf(m, &buf); 110 ret = string_escape_str(tcomm, buf, size, ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\"); 111 seq_commit(m, ret < size ? ret : -1); 112 113 seq_putc(m, '\n'); 114 } 115 116 /* 117 * The task state array is a strange "bitmap" of 118 * reasons to sleep. Thus "running" is zero, and 119 * you can test for combinations of others with 120 * simple bit tests. 121 */ 122 static const char * const task_state_array[] = { 123 124 /* states in TASK_REPORT: */ 125 "R (running)", /* 0x00 */ 126 "S (sleeping)", /* 0x01 */ 127 "D (disk sleep)", /* 0x02 */ 128 "T (stopped)", /* 0x04 */ 129 "t (tracing stop)", /* 0x08 */ 130 "X (dead)", /* 0x10 */ 131 "Z (zombie)", /* 0x20 */ 132 "P (parked)", /* 0x40 */ 133 134 /* states beyond TASK_REPORT: */ 135 "I (idle)", /* 0x80 */ 136 }; 137 138 static inline const char *get_task_state(struct task_struct *tsk) 139 { 140 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != ARRAY_SIZE(task_state_array)); 141 return task_state_array[task_state_index(tsk)]; 142 } 143 144 static inline void task_state(struct seq_file *m, struct pid_namespace *ns, 145 struct pid *pid, struct task_struct *p) 146 { 147 struct user_namespace *user_ns = seq_user_ns(m); 148 struct group_info *group_info; 149 int g, umask = -1; 150 struct task_struct *tracer; 151 const struct cred *cred; 152 pid_t ppid, tpid = 0, tgid, ngid; 153 unsigned int max_fds = 0; 154 155 rcu_read_lock(); 156 ppid = pid_alive(p) ? 157 task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0; 158 159 tracer = ptrace_parent(p); 160 if (tracer) 161 tpid = task_pid_nr_ns(tracer, ns); 162 163 tgid = task_tgid_nr_ns(p, ns); 164 ngid = task_numa_group_id(p); 165 cred = get_task_cred(p); 166 167 task_lock(p); 168 if (p->fs) 169 umask = p->fs->umask; 170 if (p->files) 171 max_fds = files_fdtable(p->files)->max_fds; 172 task_unlock(p); 173 rcu_read_unlock(); 174 175 if (umask >= 0) 176 seq_printf(m, "Umask:\t%#04o\n", umask); 177 seq_puts(m, "State:\t"); 178 seq_puts(m, get_task_state(p)); 179 180 seq_put_decimal_ull(m, "\nTgid:\t", tgid); 181 seq_put_decimal_ull(m, "\nNgid:\t", ngid); 182 seq_put_decimal_ull(m, "\nPid:\t", pid_nr_ns(pid, ns)); 183 seq_put_decimal_ull(m, "\nPPid:\t", ppid); 184 seq_put_decimal_ull(m, "\nTracerPid:\t", tpid); 185 seq_put_decimal_ull(m, "\nUid:\t", from_kuid_munged(user_ns, cred->uid)); 186 seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->euid)); 187 seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->suid)); 188 seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->fsuid)); 189 seq_put_decimal_ull(m, "\nGid:\t", from_kgid_munged(user_ns, cred->gid)); 190 seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->egid)); 191 seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->sgid)); 192 seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->fsgid)); 193 seq_put_decimal_ull(m, "\nFDSize:\t", max_fds); 194 195 seq_puts(m, "\nGroups:\t"); 196 group_info = cred->group_info; 197 for (g = 0; g < group_info->ngroups; g++) 198 seq_put_decimal_ull(m, g ? " " : "", 199 from_kgid_munged(user_ns, group_info->gid[g])); 200 put_cred(cred); 201 /* Trailing space shouldn't have been added in the first place. */ 202 seq_putc(m, ' '); 203 204 #ifdef CONFIG_PID_NS 205 seq_puts(m, "\nNStgid:"); 206 for (g = ns->level; g <= pid->level; g++) 207 seq_put_decimal_ull(m, "\t", task_tgid_nr_ns(p, pid->numbers[g].ns)); 208 seq_puts(m, "\nNSpid:"); 209 for (g = ns->level; g <= pid->level; g++) 210 seq_put_decimal_ull(m, "\t", task_pid_nr_ns(p, pid->numbers[g].ns)); 211 seq_puts(m, "\nNSpgid:"); 212 for (g = ns->level; g <= pid->level; g++) 213 seq_put_decimal_ull(m, "\t", task_pgrp_nr_ns(p, pid->numbers[g].ns)); 214 seq_puts(m, "\nNSsid:"); 215 for (g = ns->level; g <= pid->level; g++) 216 seq_put_decimal_ull(m, "\t", task_session_nr_ns(p, pid->numbers[g].ns)); 217 #endif 218 seq_putc(m, '\n'); 219 } 220 221 void render_sigset_t(struct seq_file *m, const char *header, 222 sigset_t *set) 223 { 224 int i; 225 226 seq_puts(m, header); 227 228 i = _NSIG; 229 do { 230 int x = 0; 231 232 i -= 4; 233 if (sigismember(set, i+1)) x |= 1; 234 if (sigismember(set, i+2)) x |= 2; 235 if (sigismember(set, i+3)) x |= 4; 236 if (sigismember(set, i+4)) x |= 8; 237 seq_putc(m, hex_asc[x]); 238 } while (i >= 4); 239 240 seq_putc(m, '\n'); 241 } 242 243 static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *ign, 244 sigset_t *catch) 245 { 246 struct k_sigaction *k; 247 int i; 248 249 k = p->sighand->action; 250 for (i = 1; i <= _NSIG; ++i, ++k) { 251 if (k->sa.sa_handler == SIG_IGN) 252 sigaddset(ign, i); 253 else if (k->sa.sa_handler != SIG_DFL) 254 sigaddset(catch, i); 255 } 256 } 257 258 static inline void task_sig(struct seq_file *m, struct task_struct *p) 259 { 260 unsigned long flags; 261 sigset_t pending, shpending, blocked, ignored, caught; 262 int num_threads = 0; 263 unsigned long qsize = 0; 264 unsigned long qlim = 0; 265 266 sigemptyset(&pending); 267 sigemptyset(&shpending); 268 sigemptyset(&blocked); 269 sigemptyset(&ignored); 270 sigemptyset(&caught); 271 272 if (lock_task_sighand(p, &flags)) { 273 pending = p->pending.signal; 274 shpending = p->signal->shared_pending.signal; 275 blocked = p->blocked; 276 collect_sigign_sigcatch(p, &ignored, &caught); 277 num_threads = get_nr_threads(p); 278 rcu_read_lock(); /* FIXME: is this correct? */ 279 qsize = atomic_read(&__task_cred(p)->user->sigpending); 280 rcu_read_unlock(); 281 qlim = task_rlimit(p, RLIMIT_SIGPENDING); 282 unlock_task_sighand(p, &flags); 283 } 284 285 seq_put_decimal_ull(m, "Threads:\t", num_threads); 286 seq_put_decimal_ull(m, "\nSigQ:\t", qsize); 287 seq_put_decimal_ull(m, "/", qlim); 288 289 /* render them all */ 290 render_sigset_t(m, "\nSigPnd:\t", &pending); 291 render_sigset_t(m, "ShdPnd:\t", &shpending); 292 render_sigset_t(m, "SigBlk:\t", &blocked); 293 render_sigset_t(m, "SigIgn:\t", &ignored); 294 render_sigset_t(m, "SigCgt:\t", &caught); 295 } 296 297 static void render_cap_t(struct seq_file *m, const char *header, 298 kernel_cap_t *a) 299 { 300 unsigned __capi; 301 302 seq_puts(m, header); 303 CAP_FOR_EACH_U32(__capi) { 304 seq_put_hex_ll(m, NULL, 305 a->cap[CAP_LAST_U32 - __capi], 8); 306 } 307 seq_putc(m, '\n'); 308 } 309 310 static inline void task_cap(struct seq_file *m, struct task_struct *p) 311 { 312 const struct cred *cred; 313 kernel_cap_t cap_inheritable, cap_permitted, cap_effective, 314 cap_bset, cap_ambient; 315 316 rcu_read_lock(); 317 cred = __task_cred(p); 318 cap_inheritable = cred->cap_inheritable; 319 cap_permitted = cred->cap_permitted; 320 cap_effective = cred->cap_effective; 321 cap_bset = cred->cap_bset; 322 cap_ambient = cred->cap_ambient; 323 rcu_read_unlock(); 324 325 render_cap_t(m, "CapInh:\t", &cap_inheritable); 326 render_cap_t(m, "CapPrm:\t", &cap_permitted); 327 render_cap_t(m, "CapEff:\t", &cap_effective); 328 render_cap_t(m, "CapBnd:\t", &cap_bset); 329 render_cap_t(m, "CapAmb:\t", &cap_ambient); 330 } 331 332 static inline void task_seccomp(struct seq_file *m, struct task_struct *p) 333 { 334 seq_put_decimal_ull(m, "NoNewPrivs:\t", task_no_new_privs(p)); 335 #ifdef CONFIG_SECCOMP 336 seq_put_decimal_ull(m, "\nSeccomp:\t", p->seccomp.mode); 337 #endif 338 seq_putc(m, '\n'); 339 } 340 341 static inline void task_context_switch_counts(struct seq_file *m, 342 struct task_struct *p) 343 { 344 seq_put_decimal_ull(m, "voluntary_ctxt_switches:\t", p->nvcsw); 345 seq_put_decimal_ull(m, "\nnonvoluntary_ctxt_switches:\t", p->nivcsw); 346 seq_putc(m, '\n'); 347 } 348 349 static void task_cpus_allowed(struct seq_file *m, struct task_struct *task) 350 { 351 seq_printf(m, "Cpus_allowed:\t%*pb\n", 352 cpumask_pr_args(&task->cpus_allowed)); 353 seq_printf(m, "Cpus_allowed_list:\t%*pbl\n", 354 cpumask_pr_args(&task->cpus_allowed)); 355 } 356 357 static inline void task_core_dumping(struct seq_file *m, struct mm_struct *mm) 358 { 359 seq_put_decimal_ull(m, "CoreDumping:\t", !!mm->core_state); 360 seq_putc(m, '\n'); 361 } 362 363 int proc_pid_status(struct seq_file *m, struct pid_namespace *ns, 364 struct pid *pid, struct task_struct *task) 365 { 366 struct mm_struct *mm = get_task_mm(task); 367 368 task_name(m, task); 369 task_state(m, ns, pid, task); 370 371 if (mm) { 372 task_mem(m, mm); 373 task_core_dumping(m, mm); 374 mmput(mm); 375 } 376 task_sig(m, task); 377 task_cap(m, task); 378 task_seccomp(m, task); 379 task_cpus_allowed(m, task); 380 cpuset_task_status_allowed(m, task); 381 task_context_switch_counts(m, task); 382 return 0; 383 } 384 385 static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, 386 struct pid *pid, struct task_struct *task, int whole) 387 { 388 unsigned long vsize, eip, esp, wchan = 0; 389 int priority, nice; 390 int tty_pgrp = -1, tty_nr = 0; 391 sigset_t sigign, sigcatch; 392 char state; 393 pid_t ppid = 0, pgid = -1, sid = -1; 394 int num_threads = 0; 395 int permitted; 396 struct mm_struct *mm; 397 unsigned long long start_time; 398 unsigned long cmin_flt = 0, cmaj_flt = 0; 399 unsigned long min_flt = 0, maj_flt = 0; 400 u64 cutime, cstime, utime, stime; 401 u64 cgtime, gtime; 402 unsigned long rsslim = 0; 403 char tcomm[sizeof(task->comm)]; 404 unsigned long flags; 405 406 state = *get_task_state(task); 407 vsize = eip = esp = 0; 408 permitted = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS | PTRACE_MODE_NOAUDIT); 409 mm = get_task_mm(task); 410 if (mm) { 411 vsize = task_vsize(mm); 412 /* 413 * esp and eip are intentionally zeroed out. There is no 414 * non-racy way to read them without freezing the task. 415 * Programs that need reliable values can use ptrace(2). 416 * 417 * The only exception is if the task is core dumping because 418 * a program is not able to use ptrace(2) in that case. It is 419 * safe because the task has stopped executing permanently. 420 */ 421 if (permitted && (task->flags & PF_DUMPCORE)) { 422 if (try_get_task_stack(task)) { 423 eip = KSTK_EIP(task); 424 esp = KSTK_ESP(task); 425 put_task_stack(task); 426 } 427 } 428 } 429 430 get_task_comm(tcomm, task); 431 432 sigemptyset(&sigign); 433 sigemptyset(&sigcatch); 434 cutime = cstime = utime = stime = 0; 435 cgtime = gtime = 0; 436 437 if (lock_task_sighand(task, &flags)) { 438 struct signal_struct *sig = task->signal; 439 440 if (sig->tty) { 441 struct pid *pgrp = tty_get_pgrp(sig->tty); 442 tty_pgrp = pid_nr_ns(pgrp, ns); 443 put_pid(pgrp); 444 tty_nr = new_encode_dev(tty_devnum(sig->tty)); 445 } 446 447 num_threads = get_nr_threads(task); 448 collect_sigign_sigcatch(task, &sigign, &sigcatch); 449 450 cmin_flt = sig->cmin_flt; 451 cmaj_flt = sig->cmaj_flt; 452 cutime = sig->cutime; 453 cstime = sig->cstime; 454 cgtime = sig->cgtime; 455 rsslim = READ_ONCE(sig->rlim[RLIMIT_RSS].rlim_cur); 456 457 /* add up live thread stats at the group level */ 458 if (whole) { 459 struct task_struct *t = task; 460 do { 461 min_flt += t->min_flt; 462 maj_flt += t->maj_flt; 463 gtime += task_gtime(t); 464 } while_each_thread(task, t); 465 466 min_flt += sig->min_flt; 467 maj_flt += sig->maj_flt; 468 thread_group_cputime_adjusted(task, &utime, &stime); 469 gtime += sig->gtime; 470 } 471 472 sid = task_session_nr_ns(task, ns); 473 ppid = task_tgid_nr_ns(task->real_parent, ns); 474 pgid = task_pgrp_nr_ns(task, ns); 475 476 unlock_task_sighand(task, &flags); 477 } 478 479 if (permitted && (!whole || num_threads < 2)) 480 wchan = get_wchan(task); 481 if (!whole) { 482 min_flt = task->min_flt; 483 maj_flt = task->maj_flt; 484 task_cputime_adjusted(task, &utime, &stime); 485 gtime = task_gtime(task); 486 } 487 488 /* scale priority and nice values from timeslices to -20..20 */ 489 /* to make it look like a "normal" Unix priority/nice value */ 490 priority = task_prio(task); 491 nice = task_nice(task); 492 493 /* convert nsec -> ticks */ 494 start_time = nsec_to_clock_t(task->real_start_time); 495 496 seq_put_decimal_ull(m, "", pid_nr_ns(pid, ns)); 497 seq_puts(m, " ("); 498 seq_puts(m, tcomm); 499 seq_puts(m, ") "); 500 seq_putc(m, state); 501 seq_put_decimal_ll(m, " ", ppid); 502 seq_put_decimal_ll(m, " ", pgid); 503 seq_put_decimal_ll(m, " ", sid); 504 seq_put_decimal_ll(m, " ", tty_nr); 505 seq_put_decimal_ll(m, " ", tty_pgrp); 506 seq_put_decimal_ull(m, " ", task->flags); 507 seq_put_decimal_ull(m, " ", min_flt); 508 seq_put_decimal_ull(m, " ", cmin_flt); 509 seq_put_decimal_ull(m, " ", maj_flt); 510 seq_put_decimal_ull(m, " ", cmaj_flt); 511 seq_put_decimal_ull(m, " ", nsec_to_clock_t(utime)); 512 seq_put_decimal_ull(m, " ", nsec_to_clock_t(stime)); 513 seq_put_decimal_ll(m, " ", nsec_to_clock_t(cutime)); 514 seq_put_decimal_ll(m, " ", nsec_to_clock_t(cstime)); 515 seq_put_decimal_ll(m, " ", priority); 516 seq_put_decimal_ll(m, " ", nice); 517 seq_put_decimal_ll(m, " ", num_threads); 518 seq_put_decimal_ull(m, " ", 0); 519 seq_put_decimal_ull(m, " ", start_time); 520 seq_put_decimal_ull(m, " ", vsize); 521 seq_put_decimal_ull(m, " ", mm ? get_mm_rss(mm) : 0); 522 seq_put_decimal_ull(m, " ", rsslim); 523 seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->start_code : 1) : 0); 524 seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->end_code : 1) : 0); 525 seq_put_decimal_ull(m, " ", (permitted && mm) ? mm->start_stack : 0); 526 seq_put_decimal_ull(m, " ", esp); 527 seq_put_decimal_ull(m, " ", eip); 528 /* The signal information here is obsolete. 529 * It must be decimal for Linux 2.0 compatibility. 530 * Use /proc/#/status for real-time signals. 531 */ 532 seq_put_decimal_ull(m, " ", task->pending.signal.sig[0] & 0x7fffffffUL); 533 seq_put_decimal_ull(m, " ", task->blocked.sig[0] & 0x7fffffffUL); 534 seq_put_decimal_ull(m, " ", sigign.sig[0] & 0x7fffffffUL); 535 seq_put_decimal_ull(m, " ", sigcatch.sig[0] & 0x7fffffffUL); 536 537 /* 538 * We used to output the absolute kernel address, but that's an 539 * information leak - so instead we show a 0/1 flag here, to signal 540 * to user-space whether there's a wchan field in /proc/PID/wchan. 541 * 542 * This works with older implementations of procps as well. 543 */ 544 if (wchan) 545 seq_puts(m, " 1"); 546 else 547 seq_puts(m, " 0"); 548 549 seq_put_decimal_ull(m, " ", 0); 550 seq_put_decimal_ull(m, " ", 0); 551 seq_put_decimal_ll(m, " ", task->exit_signal); 552 seq_put_decimal_ll(m, " ", task_cpu(task)); 553 seq_put_decimal_ull(m, " ", task->rt_priority); 554 seq_put_decimal_ull(m, " ", task->policy); 555 seq_put_decimal_ull(m, " ", delayacct_blkio_ticks(task)); 556 seq_put_decimal_ull(m, " ", nsec_to_clock_t(gtime)); 557 seq_put_decimal_ll(m, " ", nsec_to_clock_t(cgtime)); 558 559 if (mm && permitted) { 560 seq_put_decimal_ull(m, " ", mm->start_data); 561 seq_put_decimal_ull(m, " ", mm->end_data); 562 seq_put_decimal_ull(m, " ", mm->start_brk); 563 seq_put_decimal_ull(m, " ", mm->arg_start); 564 seq_put_decimal_ull(m, " ", mm->arg_end); 565 seq_put_decimal_ull(m, " ", mm->env_start); 566 seq_put_decimal_ull(m, " ", mm->env_end); 567 } else 568 seq_puts(m, " 0 0 0 0 0 0 0"); 569 570 if (permitted) 571 seq_put_decimal_ll(m, " ", task->exit_code); 572 else 573 seq_puts(m, " 0"); 574 575 seq_putc(m, '\n'); 576 if (mm) 577 mmput(mm); 578 return 0; 579 } 580 581 int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns, 582 struct pid *pid, struct task_struct *task) 583 { 584 return do_task_stat(m, ns, pid, task, 0); 585 } 586 587 int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns, 588 struct pid *pid, struct task_struct *task) 589 { 590 return do_task_stat(m, ns, pid, task, 1); 591 } 592 593 int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns, 594 struct pid *pid, struct task_struct *task) 595 { 596 unsigned long size = 0, resident = 0, shared = 0, text = 0, data = 0; 597 struct mm_struct *mm = get_task_mm(task); 598 599 if (mm) { 600 size = task_statm(mm, &shared, &text, &data, &resident); 601 mmput(mm); 602 } 603 /* 604 * For quick read, open code by putting numbers directly 605 * expected format is 606 * seq_printf(m, "%lu %lu %lu %lu 0 %lu 0\n", 607 * size, resident, shared, text, data); 608 */ 609 seq_put_decimal_ull(m, "", size); 610 seq_put_decimal_ull(m, " ", resident); 611 seq_put_decimal_ull(m, " ", shared); 612 seq_put_decimal_ull(m, " ", text); 613 seq_put_decimal_ull(m, " ", 0); 614 seq_put_decimal_ull(m, " ", data); 615 seq_put_decimal_ull(m, " ", 0); 616 seq_putc(m, '\n'); 617 618 return 0; 619 } 620 621 #ifdef CONFIG_PROC_CHILDREN 622 static struct pid * 623 get_children_pid(struct inode *inode, struct pid *pid_prev, loff_t pos) 624 { 625 struct task_struct *start, *task; 626 struct pid *pid = NULL; 627 628 read_lock(&tasklist_lock); 629 630 start = pid_task(proc_pid(inode), PIDTYPE_PID); 631 if (!start) 632 goto out; 633 634 /* 635 * Lets try to continue searching first, this gives 636 * us significant speedup on children-rich processes. 637 */ 638 if (pid_prev) { 639 task = pid_task(pid_prev, PIDTYPE_PID); 640 if (task && task->real_parent == start && 641 !(list_empty(&task->sibling))) { 642 if (list_is_last(&task->sibling, &start->children)) 643 goto out; 644 task = list_first_entry(&task->sibling, 645 struct task_struct, sibling); 646 pid = get_pid(task_pid(task)); 647 goto out; 648 } 649 } 650 651 /* 652 * Slow search case. 653 * 654 * We might miss some children here if children 655 * are exited while we were not holding the lock, 656 * but it was never promised to be accurate that 657 * much. 658 * 659 * "Just suppose that the parent sleeps, but N children 660 * exit after we printed their tids. Now the slow paths 661 * skips N extra children, we miss N tasks." (c) 662 * 663 * So one need to stop or freeze the leader and all 664 * its children to get a precise result. 665 */ 666 list_for_each_entry(task, &start->children, sibling) { 667 if (pos-- == 0) { 668 pid = get_pid(task_pid(task)); 669 break; 670 } 671 } 672 673 out: 674 read_unlock(&tasklist_lock); 675 return pid; 676 } 677 678 static int children_seq_show(struct seq_file *seq, void *v) 679 { 680 struct inode *inode = seq->private; 681 pid_t pid; 682 683 pid = pid_nr_ns(v, inode->i_sb->s_fs_info); 684 seq_printf(seq, "%d ", pid); 685 686 return 0; 687 } 688 689 static void *children_seq_start(struct seq_file *seq, loff_t *pos) 690 { 691 return get_children_pid(seq->private, NULL, *pos); 692 } 693 694 static void *children_seq_next(struct seq_file *seq, void *v, loff_t *pos) 695 { 696 struct pid *pid; 697 698 pid = get_children_pid(seq->private, v, *pos + 1); 699 put_pid(v); 700 701 ++*pos; 702 return pid; 703 } 704 705 static void children_seq_stop(struct seq_file *seq, void *v) 706 { 707 put_pid(v); 708 } 709 710 static const struct seq_operations children_seq_ops = { 711 .start = children_seq_start, 712 .next = children_seq_next, 713 .stop = children_seq_stop, 714 .show = children_seq_show, 715 }; 716 717 static int children_seq_open(struct inode *inode, struct file *file) 718 { 719 struct seq_file *m; 720 int ret; 721 722 ret = seq_open(file, &children_seq_ops); 723 if (ret) 724 return ret; 725 726 m = file->private_data; 727 m->private = inode; 728 729 return ret; 730 } 731 732 const struct file_operations proc_tid_children_operations = { 733 .open = children_seq_open, 734 .read = seq_read, 735 .llseek = seq_lseek, 736 .release = seq_release, 737 }; 738 #endif /* CONFIG_PROC_CHILDREN */ 739