1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/proc/base.c 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 * 7 * proc base directory handling functions 8 * 9 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part. 10 * Instead of using magical inumbers to determine the kind of object 11 * we allocate and fill in-core inodes upon lookup. They don't even 12 * go into icache. We cache the reference to task_struct upon lookup too. 13 * Eventually it should become a filesystem in its own. We don't use the 14 * rest of procfs anymore. 15 * 16 * 17 * Changelog: 18 * 17-Jan-2005 19 * Allan Bezerra 20 * Bruna Moreira <bruna.moreira@indt.org.br> 21 * Edjard Mota <edjard.mota@indt.org.br> 22 * Ilias Biris <ilias.biris@indt.org.br> 23 * Mauricio Lin <mauricio.lin@indt.org.br> 24 * 25 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 26 * 27 * A new process specific entry (smaps) included in /proc. It shows the 28 * size of rss for each memory area. The maps entry lacks information 29 * about physical memory size (rss) for each mapped file, i.e., 30 * rss information for executables and library files. 31 * This additional information is useful for any tools that need to know 32 * about physical memory consumption for a process specific library. 33 * 34 * Changelog: 35 * 21-Feb-2005 36 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 37 * Pud inclusion in the page table walking. 38 * 39 * ChangeLog: 40 * 10-Mar-2005 41 * 10LE Instituto Nokia de Tecnologia - INdT: 42 * A better way to walks through the page table as suggested by Hugh Dickins. 43 * 44 * Simo Piiroinen <simo.piiroinen@nokia.com>: 45 * Smaps information related to shared, private, clean and dirty pages. 46 * 47 * Paul Mundt <paul.mundt@nokia.com>: 48 * Overall revision about smaps. 49 */ 50 51 #include <linux/uaccess.h> 52 53 #include <linux/errno.h> 54 #include <linux/time.h> 55 #include <linux/proc_fs.h> 56 #include <linux/stat.h> 57 #include <linux/task_io_accounting_ops.h> 58 #include <linux/init.h> 59 #include <linux/capability.h> 60 #include <linux/file.h> 61 #include <linux/fdtable.h> 62 #include <linux/string.h> 63 #include <linux/seq_file.h> 64 #include <linux/namei.h> 65 #include <linux/mnt_namespace.h> 66 #include <linux/mm.h> 67 #include <linux/swap.h> 68 #include <linux/rcupdate.h> 69 #include <linux/kallsyms.h> 70 #include <linux/stacktrace.h> 71 #include <linux/resource.h> 72 #include <linux/module.h> 73 #include <linux/mount.h> 74 #include <linux/security.h> 75 #include <linux/ptrace.h> 76 #include <linux/tracehook.h> 77 #include <linux/printk.h> 78 #include <linux/cache.h> 79 #include <linux/cgroup.h> 80 #include <linux/cpuset.h> 81 #include <linux/audit.h> 82 #include <linux/poll.h> 83 #include <linux/nsproxy.h> 84 #include <linux/oom.h> 85 #include <linux/elf.h> 86 #include <linux/pid_namespace.h> 87 #include <linux/user_namespace.h> 88 #include <linux/fs_struct.h> 89 #include <linux/slab.h> 90 #include <linux/sched/autogroup.h> 91 #include <linux/sched/mm.h> 92 #include <linux/sched/coredump.h> 93 #include <linux/sched/debug.h> 94 #include <linux/sched/stat.h> 95 #include <linux/flex_array.h> 96 #include <linux/posix-timers.h> 97 #include <trace/events/oom.h> 98 #include "internal.h" 99 #include "fd.h" 100 101 #include "../../lib/kstrtox.h" 102 103 /* NOTE: 104 * Implementing inode permission operations in /proc is almost 105 * certainly an error. Permission checks need to happen during 106 * each system call not at open time. The reason is that most of 107 * what we wish to check for permissions in /proc varies at runtime. 108 * 109 * The classic example of a problem is opening file descriptors 110 * in /proc for a task before it execs a suid executable. 111 */ 112 113 static u8 nlink_tid __ro_after_init; 114 static u8 nlink_tgid __ro_after_init; 115 116 struct pid_entry { 117 const char *name; 118 unsigned int len; 119 umode_t mode; 120 const struct inode_operations *iop; 121 const struct file_operations *fop; 122 union proc_op op; 123 }; 124 125 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 126 .name = (NAME), \ 127 .len = sizeof(NAME) - 1, \ 128 .mode = MODE, \ 129 .iop = IOP, \ 130 .fop = FOP, \ 131 .op = OP, \ 132 } 133 134 #define DIR(NAME, MODE, iops, fops) \ 135 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} ) 136 #define LNK(NAME, get_link) \ 137 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 138 &proc_pid_link_inode_operations, NULL, \ 139 { .proc_get_link = get_link } ) 140 #define REG(NAME, MODE, fops) \ 141 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {}) 142 #define ONE(NAME, MODE, show) \ 143 NOD(NAME, (S_IFREG|(MODE)), \ 144 NULL, &proc_single_file_operations, \ 145 { .proc_show = show } ) 146 147 /* 148 * Count the number of hardlinks for the pid_entry table, excluding the . 149 * and .. links. 150 */ 151 static unsigned int __init pid_entry_nlink(const struct pid_entry *entries, 152 unsigned int n) 153 { 154 unsigned int i; 155 unsigned int count; 156 157 count = 2; 158 for (i = 0; i < n; ++i) { 159 if (S_ISDIR(entries[i].mode)) 160 ++count; 161 } 162 163 return count; 164 } 165 166 static int get_task_root(struct task_struct *task, struct path *root) 167 { 168 int result = -ENOENT; 169 170 task_lock(task); 171 if (task->fs) { 172 get_fs_root(task->fs, root); 173 result = 0; 174 } 175 task_unlock(task); 176 return result; 177 } 178 179 static int proc_cwd_link(struct dentry *dentry, struct path *path) 180 { 181 struct task_struct *task = get_proc_task(d_inode(dentry)); 182 int result = -ENOENT; 183 184 if (task) { 185 task_lock(task); 186 if (task->fs) { 187 get_fs_pwd(task->fs, path); 188 result = 0; 189 } 190 task_unlock(task); 191 put_task_struct(task); 192 } 193 return result; 194 } 195 196 static int proc_root_link(struct dentry *dentry, struct path *path) 197 { 198 struct task_struct *task = get_proc_task(d_inode(dentry)); 199 int result = -ENOENT; 200 201 if (task) { 202 result = get_task_root(task, path); 203 put_task_struct(task); 204 } 205 return result; 206 } 207 208 static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf, 209 size_t count, loff_t *ppos) 210 { 211 unsigned long arg_start, arg_end, env_start, env_end; 212 unsigned long pos, len; 213 char *page; 214 215 /* Check if process spawned far enough to have cmdline. */ 216 if (!mm->env_end) 217 return 0; 218 219 spin_lock(&mm->arg_lock); 220 arg_start = mm->arg_start; 221 arg_end = mm->arg_end; 222 env_start = mm->env_start; 223 env_end = mm->env_end; 224 spin_unlock(&mm->arg_lock); 225 226 if (arg_start >= arg_end) 227 return 0; 228 229 /* 230 * We have traditionally allowed the user to re-write 231 * the argument strings and overflow the end result 232 * into the environment section. But only do that if 233 * the environment area is contiguous to the arguments. 234 */ 235 if (env_start != arg_end || env_start >= env_end) 236 env_start = env_end = arg_end; 237 238 /* .. and limit it to a maximum of one page of slop */ 239 if (env_end >= arg_end + PAGE_SIZE) 240 env_end = arg_end + PAGE_SIZE - 1; 241 242 /* We're not going to care if "*ppos" has high bits set */ 243 pos = arg_start + *ppos; 244 245 /* .. but we do check the result is in the proper range */ 246 if (pos < arg_start || pos >= env_end) 247 return 0; 248 249 /* .. and we never go past env_end */ 250 if (env_end - pos < count) 251 count = env_end - pos; 252 253 page = (char *)__get_free_page(GFP_KERNEL); 254 if (!page) 255 return -ENOMEM; 256 257 len = 0; 258 while (count) { 259 int got; 260 size_t size = min_t(size_t, PAGE_SIZE, count); 261 long offset; 262 263 /* 264 * Are we already starting past the official end? 265 * We always include the last byte that is *supposed* 266 * to be NUL 267 */ 268 offset = (pos >= arg_end) ? pos - arg_end + 1 : 0; 269 270 got = access_remote_vm(mm, pos - offset, page, size + offset, FOLL_ANON); 271 if (got <= offset) 272 break; 273 got -= offset; 274 275 /* Don't walk past a NUL character once you hit arg_end */ 276 if (pos + got >= arg_end) { 277 int n = 0; 278 279 /* 280 * If we started before 'arg_end' but ended up 281 * at or after it, we start the NUL character 282 * check at arg_end-1 (where we expect the normal 283 * EOF to be). 284 * 285 * NOTE! This is smaller than 'got', because 286 * pos + got >= arg_end 287 */ 288 if (pos < arg_end) 289 n = arg_end - pos - 1; 290 291 /* Cut off at first NUL after 'n' */ 292 got = n + strnlen(page+n, offset+got-n); 293 if (got < offset) 294 break; 295 got -= offset; 296 297 /* Include the NUL if it existed */ 298 if (got < size) 299 got++; 300 } 301 302 got -= copy_to_user(buf, page+offset, got); 303 if (unlikely(!got)) { 304 if (!len) 305 len = -EFAULT; 306 break; 307 } 308 pos += got; 309 buf += got; 310 len += got; 311 count -= got; 312 } 313 314 free_page((unsigned long)page); 315 return len; 316 } 317 318 static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf, 319 size_t count, loff_t *pos) 320 { 321 struct mm_struct *mm; 322 ssize_t ret; 323 324 mm = get_task_mm(tsk); 325 if (!mm) 326 return 0; 327 328 ret = get_mm_cmdline(mm, buf, count, pos); 329 mmput(mm); 330 return ret; 331 } 332 333 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, 334 size_t count, loff_t *pos) 335 { 336 struct task_struct *tsk; 337 ssize_t ret; 338 339 BUG_ON(*pos < 0); 340 341 tsk = get_proc_task(file_inode(file)); 342 if (!tsk) 343 return -ESRCH; 344 ret = get_task_cmdline(tsk, buf, count, pos); 345 put_task_struct(tsk); 346 if (ret > 0) 347 *pos += ret; 348 return ret; 349 } 350 351 static const struct file_operations proc_pid_cmdline_ops = { 352 .read = proc_pid_cmdline_read, 353 .llseek = generic_file_llseek, 354 }; 355 356 #ifdef CONFIG_KALLSYMS 357 /* 358 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 359 * Returns the resolved symbol. If that fails, simply return the address. 360 */ 361 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns, 362 struct pid *pid, struct task_struct *task) 363 { 364 unsigned long wchan; 365 char symname[KSYM_NAME_LEN]; 366 367 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 368 goto print0; 369 370 wchan = get_wchan(task); 371 if (wchan && !lookup_symbol_name(wchan, symname)) { 372 seq_puts(m, symname); 373 return 0; 374 } 375 376 print0: 377 seq_putc(m, '0'); 378 return 0; 379 } 380 #endif /* CONFIG_KALLSYMS */ 381 382 static int lock_trace(struct task_struct *task) 383 { 384 int err = mutex_lock_killable(&task->signal->cred_guard_mutex); 385 if (err) 386 return err; 387 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) { 388 mutex_unlock(&task->signal->cred_guard_mutex); 389 return -EPERM; 390 } 391 return 0; 392 } 393 394 static void unlock_trace(struct task_struct *task) 395 { 396 mutex_unlock(&task->signal->cred_guard_mutex); 397 } 398 399 #ifdef CONFIG_STACKTRACE 400 401 #define MAX_STACK_TRACE_DEPTH 64 402 403 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, 404 struct pid *pid, struct task_struct *task) 405 { 406 struct stack_trace trace; 407 unsigned long *entries; 408 int err; 409 410 /* 411 * The ability to racily run the kernel stack unwinder on a running task 412 * and then observe the unwinder output is scary; while it is useful for 413 * debugging kernel issues, it can also allow an attacker to leak kernel 414 * stack contents. 415 * Doing this in a manner that is at least safe from races would require 416 * some work to ensure that the remote task can not be scheduled; and 417 * even then, this would still expose the unwinder as local attack 418 * surface. 419 * Therefore, this interface is restricted to root. 420 */ 421 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) 422 return -EACCES; 423 424 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries), 425 GFP_KERNEL); 426 if (!entries) 427 return -ENOMEM; 428 429 trace.nr_entries = 0; 430 trace.max_entries = MAX_STACK_TRACE_DEPTH; 431 trace.entries = entries; 432 trace.skip = 0; 433 434 err = lock_trace(task); 435 if (!err) { 436 unsigned int i; 437 438 save_stack_trace_tsk(task, &trace); 439 440 for (i = 0; i < trace.nr_entries; i++) { 441 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]); 442 } 443 unlock_trace(task); 444 } 445 kfree(entries); 446 447 return err; 448 } 449 #endif 450 451 #ifdef CONFIG_SCHED_INFO 452 /* 453 * Provides /proc/PID/schedstat 454 */ 455 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, 456 struct pid *pid, struct task_struct *task) 457 { 458 if (unlikely(!sched_info_on())) 459 seq_printf(m, "0 0 0\n"); 460 else 461 seq_printf(m, "%llu %llu %lu\n", 462 (unsigned long long)task->se.sum_exec_runtime, 463 (unsigned long long)task->sched_info.run_delay, 464 task->sched_info.pcount); 465 466 return 0; 467 } 468 #endif 469 470 #ifdef CONFIG_LATENCYTOP 471 static int lstats_show_proc(struct seq_file *m, void *v) 472 { 473 int i; 474 struct inode *inode = m->private; 475 struct task_struct *task = get_proc_task(inode); 476 477 if (!task) 478 return -ESRCH; 479 seq_puts(m, "Latency Top version : v0.1\n"); 480 for (i = 0; i < LT_SAVECOUNT; i++) { 481 struct latency_record *lr = &task->latency_record[i]; 482 if (lr->backtrace[0]) { 483 int q; 484 seq_printf(m, "%i %li %li", 485 lr->count, lr->time, lr->max); 486 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 487 unsigned long bt = lr->backtrace[q]; 488 if (!bt) 489 break; 490 if (bt == ULONG_MAX) 491 break; 492 seq_printf(m, " %ps", (void *)bt); 493 } 494 seq_putc(m, '\n'); 495 } 496 497 } 498 put_task_struct(task); 499 return 0; 500 } 501 502 static int lstats_open(struct inode *inode, struct file *file) 503 { 504 return single_open(file, lstats_show_proc, inode); 505 } 506 507 static ssize_t lstats_write(struct file *file, const char __user *buf, 508 size_t count, loff_t *offs) 509 { 510 struct task_struct *task = get_proc_task(file_inode(file)); 511 512 if (!task) 513 return -ESRCH; 514 clear_all_latency_tracing(task); 515 put_task_struct(task); 516 517 return count; 518 } 519 520 static const struct file_operations proc_lstats_operations = { 521 .open = lstats_open, 522 .read = seq_read, 523 .write = lstats_write, 524 .llseek = seq_lseek, 525 .release = single_release, 526 }; 527 528 #endif 529 530 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns, 531 struct pid *pid, struct task_struct *task) 532 { 533 unsigned long totalpages = totalram_pages() + total_swap_pages; 534 unsigned long points = 0; 535 536 points = oom_badness(task, NULL, NULL, totalpages) * 537 1000 / totalpages; 538 seq_printf(m, "%lu\n", points); 539 540 return 0; 541 } 542 543 struct limit_names { 544 const char *name; 545 const char *unit; 546 }; 547 548 static const struct limit_names lnames[RLIM_NLIMITS] = { 549 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 550 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 551 [RLIMIT_DATA] = {"Max data size", "bytes"}, 552 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 553 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 554 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 555 [RLIMIT_NPROC] = {"Max processes", "processes"}, 556 [RLIMIT_NOFILE] = {"Max open files", "files"}, 557 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 558 [RLIMIT_AS] = {"Max address space", "bytes"}, 559 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 560 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 561 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 562 [RLIMIT_NICE] = {"Max nice priority", NULL}, 563 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 564 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 565 }; 566 567 /* Display limits for a process */ 568 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns, 569 struct pid *pid, struct task_struct *task) 570 { 571 unsigned int i; 572 unsigned long flags; 573 574 struct rlimit rlim[RLIM_NLIMITS]; 575 576 if (!lock_task_sighand(task, &flags)) 577 return 0; 578 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 579 unlock_task_sighand(task, &flags); 580 581 /* 582 * print the file header 583 */ 584 seq_puts(m, "Limit " 585 "Soft Limit " 586 "Hard Limit " 587 "Units \n"); 588 589 for (i = 0; i < RLIM_NLIMITS; i++) { 590 if (rlim[i].rlim_cur == RLIM_INFINITY) 591 seq_printf(m, "%-25s %-20s ", 592 lnames[i].name, "unlimited"); 593 else 594 seq_printf(m, "%-25s %-20lu ", 595 lnames[i].name, rlim[i].rlim_cur); 596 597 if (rlim[i].rlim_max == RLIM_INFINITY) 598 seq_printf(m, "%-20s ", "unlimited"); 599 else 600 seq_printf(m, "%-20lu ", rlim[i].rlim_max); 601 602 if (lnames[i].unit) 603 seq_printf(m, "%-10s\n", lnames[i].unit); 604 else 605 seq_putc(m, '\n'); 606 } 607 608 return 0; 609 } 610 611 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 612 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns, 613 struct pid *pid, struct task_struct *task) 614 { 615 long nr; 616 unsigned long args[6], sp, pc; 617 int res; 618 619 res = lock_trace(task); 620 if (res) 621 return res; 622 623 if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) 624 seq_puts(m, "running\n"); 625 else if (nr < 0) 626 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc); 627 else 628 seq_printf(m, 629 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", 630 nr, 631 args[0], args[1], args[2], args[3], args[4], args[5], 632 sp, pc); 633 unlock_trace(task); 634 635 return 0; 636 } 637 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 638 639 /************************************************************************/ 640 /* Here the fs part begins */ 641 /************************************************************************/ 642 643 /* permission checks */ 644 static int proc_fd_access_allowed(struct inode *inode) 645 { 646 struct task_struct *task; 647 int allowed = 0; 648 /* Allow access to a task's file descriptors if it is us or we 649 * may use ptrace attach to the process and find out that 650 * information. 651 */ 652 task = get_proc_task(inode); 653 if (task) { 654 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 655 put_task_struct(task); 656 } 657 return allowed; 658 } 659 660 int proc_setattr(struct dentry *dentry, struct iattr *attr) 661 { 662 int error; 663 struct inode *inode = d_inode(dentry); 664 665 if (attr->ia_valid & ATTR_MODE) 666 return -EPERM; 667 668 error = setattr_prepare(dentry, attr); 669 if (error) 670 return error; 671 672 setattr_copy(inode, attr); 673 mark_inode_dirty(inode); 674 return 0; 675 } 676 677 /* 678 * May current process learn task's sched/cmdline info (for hide_pid_min=1) 679 * or euid/egid (for hide_pid_min=2)? 680 */ 681 static bool has_pid_permissions(struct pid_namespace *pid, 682 struct task_struct *task, 683 int hide_pid_min) 684 { 685 if (pid->hide_pid < hide_pid_min) 686 return true; 687 if (in_group_p(pid->pid_gid)) 688 return true; 689 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 690 } 691 692 693 static int proc_pid_permission(struct inode *inode, int mask) 694 { 695 struct pid_namespace *pid = proc_pid_ns(inode); 696 struct task_struct *task; 697 bool has_perms; 698 699 task = get_proc_task(inode); 700 if (!task) 701 return -ESRCH; 702 has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS); 703 put_task_struct(task); 704 705 if (!has_perms) { 706 if (pid->hide_pid == HIDEPID_INVISIBLE) { 707 /* 708 * Let's make getdents(), stat(), and open() 709 * consistent with each other. If a process 710 * may not stat() a file, it shouldn't be seen 711 * in procfs at all. 712 */ 713 return -ENOENT; 714 } 715 716 return -EPERM; 717 } 718 return generic_permission(inode, mask); 719 } 720 721 722 723 static const struct inode_operations proc_def_inode_operations = { 724 .setattr = proc_setattr, 725 }; 726 727 static int proc_single_show(struct seq_file *m, void *v) 728 { 729 struct inode *inode = m->private; 730 struct pid_namespace *ns = proc_pid_ns(inode); 731 struct pid *pid = proc_pid(inode); 732 struct task_struct *task; 733 int ret; 734 735 task = get_pid_task(pid, PIDTYPE_PID); 736 if (!task) 737 return -ESRCH; 738 739 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 740 741 put_task_struct(task); 742 return ret; 743 } 744 745 static int proc_single_open(struct inode *inode, struct file *filp) 746 { 747 return single_open(filp, proc_single_show, inode); 748 } 749 750 static const struct file_operations proc_single_file_operations = { 751 .open = proc_single_open, 752 .read = seq_read, 753 .llseek = seq_lseek, 754 .release = single_release, 755 }; 756 757 758 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode) 759 { 760 struct task_struct *task = get_proc_task(inode); 761 struct mm_struct *mm = ERR_PTR(-ESRCH); 762 763 if (task) { 764 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS); 765 put_task_struct(task); 766 767 if (!IS_ERR_OR_NULL(mm)) { 768 /* ensure this mm_struct can't be freed */ 769 mmgrab(mm); 770 /* but do not pin its memory */ 771 mmput(mm); 772 } 773 } 774 775 return mm; 776 } 777 778 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) 779 { 780 struct mm_struct *mm = proc_mem_open(inode, mode); 781 782 if (IS_ERR(mm)) 783 return PTR_ERR(mm); 784 785 file->private_data = mm; 786 return 0; 787 } 788 789 static int mem_open(struct inode *inode, struct file *file) 790 { 791 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH); 792 793 /* OK to pass negative loff_t, we can catch out-of-range */ 794 file->f_mode |= FMODE_UNSIGNED_OFFSET; 795 796 return ret; 797 } 798 799 static ssize_t mem_rw(struct file *file, char __user *buf, 800 size_t count, loff_t *ppos, int write) 801 { 802 struct mm_struct *mm = file->private_data; 803 unsigned long addr = *ppos; 804 ssize_t copied; 805 char *page; 806 unsigned int flags; 807 808 if (!mm) 809 return 0; 810 811 page = (char *)__get_free_page(GFP_KERNEL); 812 if (!page) 813 return -ENOMEM; 814 815 copied = 0; 816 if (!mmget_not_zero(mm)) 817 goto free; 818 819 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0); 820 821 while (count > 0) { 822 int this_len = min_t(int, count, PAGE_SIZE); 823 824 if (write && copy_from_user(page, buf, this_len)) { 825 copied = -EFAULT; 826 break; 827 } 828 829 this_len = access_remote_vm(mm, addr, page, this_len, flags); 830 if (!this_len) { 831 if (!copied) 832 copied = -EIO; 833 break; 834 } 835 836 if (!write && copy_to_user(buf, page, this_len)) { 837 copied = -EFAULT; 838 break; 839 } 840 841 buf += this_len; 842 addr += this_len; 843 copied += this_len; 844 count -= this_len; 845 } 846 *ppos = addr; 847 848 mmput(mm); 849 free: 850 free_page((unsigned long) page); 851 return copied; 852 } 853 854 static ssize_t mem_read(struct file *file, char __user *buf, 855 size_t count, loff_t *ppos) 856 { 857 return mem_rw(file, buf, count, ppos, 0); 858 } 859 860 static ssize_t mem_write(struct file *file, const char __user *buf, 861 size_t count, loff_t *ppos) 862 { 863 return mem_rw(file, (char __user*)buf, count, ppos, 1); 864 } 865 866 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 867 { 868 switch (orig) { 869 case 0: 870 file->f_pos = offset; 871 break; 872 case 1: 873 file->f_pos += offset; 874 break; 875 default: 876 return -EINVAL; 877 } 878 force_successful_syscall_return(); 879 return file->f_pos; 880 } 881 882 static int mem_release(struct inode *inode, struct file *file) 883 { 884 struct mm_struct *mm = file->private_data; 885 if (mm) 886 mmdrop(mm); 887 return 0; 888 } 889 890 static const struct file_operations proc_mem_operations = { 891 .llseek = mem_lseek, 892 .read = mem_read, 893 .write = mem_write, 894 .open = mem_open, 895 .release = mem_release, 896 }; 897 898 static int environ_open(struct inode *inode, struct file *file) 899 { 900 return __mem_open(inode, file, PTRACE_MODE_READ); 901 } 902 903 static ssize_t environ_read(struct file *file, char __user *buf, 904 size_t count, loff_t *ppos) 905 { 906 char *page; 907 unsigned long src = *ppos; 908 int ret = 0; 909 struct mm_struct *mm = file->private_data; 910 unsigned long env_start, env_end; 911 912 /* Ensure the process spawned far enough to have an environment. */ 913 if (!mm || !mm->env_end) 914 return 0; 915 916 page = (char *)__get_free_page(GFP_KERNEL); 917 if (!page) 918 return -ENOMEM; 919 920 ret = 0; 921 if (!mmget_not_zero(mm)) 922 goto free; 923 924 spin_lock(&mm->arg_lock); 925 env_start = mm->env_start; 926 env_end = mm->env_end; 927 spin_unlock(&mm->arg_lock); 928 929 while (count > 0) { 930 size_t this_len, max_len; 931 int retval; 932 933 if (src >= (env_end - env_start)) 934 break; 935 936 this_len = env_end - (env_start + src); 937 938 max_len = min_t(size_t, PAGE_SIZE, count); 939 this_len = min(max_len, this_len); 940 941 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON); 942 943 if (retval <= 0) { 944 ret = retval; 945 break; 946 } 947 948 if (copy_to_user(buf, page, retval)) { 949 ret = -EFAULT; 950 break; 951 } 952 953 ret += retval; 954 src += retval; 955 buf += retval; 956 count -= retval; 957 } 958 *ppos = src; 959 mmput(mm); 960 961 free: 962 free_page((unsigned long) page); 963 return ret; 964 } 965 966 static const struct file_operations proc_environ_operations = { 967 .open = environ_open, 968 .read = environ_read, 969 .llseek = generic_file_llseek, 970 .release = mem_release, 971 }; 972 973 static int auxv_open(struct inode *inode, struct file *file) 974 { 975 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS); 976 } 977 978 static ssize_t auxv_read(struct file *file, char __user *buf, 979 size_t count, loff_t *ppos) 980 { 981 struct mm_struct *mm = file->private_data; 982 unsigned int nwords = 0; 983 984 if (!mm) 985 return 0; 986 do { 987 nwords += 2; 988 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 989 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv, 990 nwords * sizeof(mm->saved_auxv[0])); 991 } 992 993 static const struct file_operations proc_auxv_operations = { 994 .open = auxv_open, 995 .read = auxv_read, 996 .llseek = generic_file_llseek, 997 .release = mem_release, 998 }; 999 1000 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count, 1001 loff_t *ppos) 1002 { 1003 struct task_struct *task = get_proc_task(file_inode(file)); 1004 char buffer[PROC_NUMBUF]; 1005 int oom_adj = OOM_ADJUST_MIN; 1006 size_t len; 1007 1008 if (!task) 1009 return -ESRCH; 1010 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX) 1011 oom_adj = OOM_ADJUST_MAX; 1012 else 1013 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) / 1014 OOM_SCORE_ADJ_MAX; 1015 put_task_struct(task); 1016 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj); 1017 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1018 } 1019 1020 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy) 1021 { 1022 static DEFINE_MUTEX(oom_adj_mutex); 1023 struct mm_struct *mm = NULL; 1024 struct task_struct *task; 1025 int err = 0; 1026 1027 task = get_proc_task(file_inode(file)); 1028 if (!task) 1029 return -ESRCH; 1030 1031 mutex_lock(&oom_adj_mutex); 1032 if (legacy) { 1033 if (oom_adj < task->signal->oom_score_adj && 1034 !capable(CAP_SYS_RESOURCE)) { 1035 err = -EACCES; 1036 goto err_unlock; 1037 } 1038 /* 1039 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use 1040 * /proc/pid/oom_score_adj instead. 1041 */ 1042 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 1043 current->comm, task_pid_nr(current), task_pid_nr(task), 1044 task_pid_nr(task)); 1045 } else { 1046 if ((short)oom_adj < task->signal->oom_score_adj_min && 1047 !capable(CAP_SYS_RESOURCE)) { 1048 err = -EACCES; 1049 goto err_unlock; 1050 } 1051 } 1052 1053 /* 1054 * Make sure we will check other processes sharing the mm if this is 1055 * not vfrok which wants its own oom_score_adj. 1056 * pin the mm so it doesn't go away and get reused after task_unlock 1057 */ 1058 if (!task->vfork_done) { 1059 struct task_struct *p = find_lock_task_mm(task); 1060 1061 if (p) { 1062 if (atomic_read(&p->mm->mm_users) > 1) { 1063 mm = p->mm; 1064 mmgrab(mm); 1065 } 1066 task_unlock(p); 1067 } 1068 } 1069 1070 task->signal->oom_score_adj = oom_adj; 1071 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1072 task->signal->oom_score_adj_min = (short)oom_adj; 1073 trace_oom_score_adj_update(task); 1074 1075 if (mm) { 1076 struct task_struct *p; 1077 1078 rcu_read_lock(); 1079 for_each_process(p) { 1080 if (same_thread_group(task, p)) 1081 continue; 1082 1083 /* do not touch kernel threads or the global init */ 1084 if (p->flags & PF_KTHREAD || is_global_init(p)) 1085 continue; 1086 1087 task_lock(p); 1088 if (!p->vfork_done && process_shares_mm(p, mm)) { 1089 pr_info("updating oom_score_adj for %d (%s) from %d to %d because it shares mm with %d (%s). Report if this is unexpected.\n", 1090 task_pid_nr(p), p->comm, 1091 p->signal->oom_score_adj, oom_adj, 1092 task_pid_nr(task), task->comm); 1093 p->signal->oom_score_adj = oom_adj; 1094 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1095 p->signal->oom_score_adj_min = (short)oom_adj; 1096 } 1097 task_unlock(p); 1098 } 1099 rcu_read_unlock(); 1100 mmdrop(mm); 1101 } 1102 err_unlock: 1103 mutex_unlock(&oom_adj_mutex); 1104 put_task_struct(task); 1105 return err; 1106 } 1107 1108 /* 1109 * /proc/pid/oom_adj exists solely for backwards compatibility with previous 1110 * kernels. The effective policy is defined by oom_score_adj, which has a 1111 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly. 1112 * Values written to oom_adj are simply mapped linearly to oom_score_adj. 1113 * Processes that become oom disabled via oom_adj will still be oom disabled 1114 * with this implementation. 1115 * 1116 * oom_adj cannot be removed since existing userspace binaries use it. 1117 */ 1118 static ssize_t oom_adj_write(struct file *file, const char __user *buf, 1119 size_t count, loff_t *ppos) 1120 { 1121 char buffer[PROC_NUMBUF]; 1122 int oom_adj; 1123 int err; 1124 1125 memset(buffer, 0, sizeof(buffer)); 1126 if (count > sizeof(buffer) - 1) 1127 count = sizeof(buffer) - 1; 1128 if (copy_from_user(buffer, buf, count)) { 1129 err = -EFAULT; 1130 goto out; 1131 } 1132 1133 err = kstrtoint(strstrip(buffer), 0, &oom_adj); 1134 if (err) 1135 goto out; 1136 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) && 1137 oom_adj != OOM_DISABLE) { 1138 err = -EINVAL; 1139 goto out; 1140 } 1141 1142 /* 1143 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 1144 * value is always attainable. 1145 */ 1146 if (oom_adj == OOM_ADJUST_MAX) 1147 oom_adj = OOM_SCORE_ADJ_MAX; 1148 else 1149 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE; 1150 1151 err = __set_oom_adj(file, oom_adj, true); 1152 out: 1153 return err < 0 ? err : count; 1154 } 1155 1156 static const struct file_operations proc_oom_adj_operations = { 1157 .read = oom_adj_read, 1158 .write = oom_adj_write, 1159 .llseek = generic_file_llseek, 1160 }; 1161 1162 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 1163 size_t count, loff_t *ppos) 1164 { 1165 struct task_struct *task = get_proc_task(file_inode(file)); 1166 char buffer[PROC_NUMBUF]; 1167 short oom_score_adj = OOM_SCORE_ADJ_MIN; 1168 size_t len; 1169 1170 if (!task) 1171 return -ESRCH; 1172 oom_score_adj = task->signal->oom_score_adj; 1173 put_task_struct(task); 1174 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj); 1175 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1176 } 1177 1178 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1179 size_t count, loff_t *ppos) 1180 { 1181 char buffer[PROC_NUMBUF]; 1182 int oom_score_adj; 1183 int err; 1184 1185 memset(buffer, 0, sizeof(buffer)); 1186 if (count > sizeof(buffer) - 1) 1187 count = sizeof(buffer) - 1; 1188 if (copy_from_user(buffer, buf, count)) { 1189 err = -EFAULT; 1190 goto out; 1191 } 1192 1193 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 1194 if (err) 1195 goto out; 1196 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1197 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1198 err = -EINVAL; 1199 goto out; 1200 } 1201 1202 err = __set_oom_adj(file, oom_score_adj, false); 1203 out: 1204 return err < 0 ? err : count; 1205 } 1206 1207 static const struct file_operations proc_oom_score_adj_operations = { 1208 .read = oom_score_adj_read, 1209 .write = oom_score_adj_write, 1210 .llseek = default_llseek, 1211 }; 1212 1213 #ifdef CONFIG_AUDITSYSCALL 1214 #define TMPBUFLEN 11 1215 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1216 size_t count, loff_t *ppos) 1217 { 1218 struct inode * inode = file_inode(file); 1219 struct task_struct *task = get_proc_task(inode); 1220 ssize_t length; 1221 char tmpbuf[TMPBUFLEN]; 1222 1223 if (!task) 1224 return -ESRCH; 1225 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1226 from_kuid(file->f_cred->user_ns, 1227 audit_get_loginuid(task))); 1228 put_task_struct(task); 1229 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1230 } 1231 1232 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1233 size_t count, loff_t *ppos) 1234 { 1235 struct inode * inode = file_inode(file); 1236 uid_t loginuid; 1237 kuid_t kloginuid; 1238 int rv; 1239 1240 rcu_read_lock(); 1241 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1242 rcu_read_unlock(); 1243 return -EPERM; 1244 } 1245 rcu_read_unlock(); 1246 1247 if (*ppos != 0) { 1248 /* No partial writes. */ 1249 return -EINVAL; 1250 } 1251 1252 rv = kstrtou32_from_user(buf, count, 10, &loginuid); 1253 if (rv < 0) 1254 return rv; 1255 1256 /* is userspace tring to explicitly UNSET the loginuid? */ 1257 if (loginuid == AUDIT_UID_UNSET) { 1258 kloginuid = INVALID_UID; 1259 } else { 1260 kloginuid = make_kuid(file->f_cred->user_ns, loginuid); 1261 if (!uid_valid(kloginuid)) 1262 return -EINVAL; 1263 } 1264 1265 rv = audit_set_loginuid(kloginuid); 1266 if (rv < 0) 1267 return rv; 1268 return count; 1269 } 1270 1271 static const struct file_operations proc_loginuid_operations = { 1272 .read = proc_loginuid_read, 1273 .write = proc_loginuid_write, 1274 .llseek = generic_file_llseek, 1275 }; 1276 1277 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1278 size_t count, loff_t *ppos) 1279 { 1280 struct inode * inode = file_inode(file); 1281 struct task_struct *task = get_proc_task(inode); 1282 ssize_t length; 1283 char tmpbuf[TMPBUFLEN]; 1284 1285 if (!task) 1286 return -ESRCH; 1287 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1288 audit_get_sessionid(task)); 1289 put_task_struct(task); 1290 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1291 } 1292 1293 static const struct file_operations proc_sessionid_operations = { 1294 .read = proc_sessionid_read, 1295 .llseek = generic_file_llseek, 1296 }; 1297 #endif 1298 1299 #ifdef CONFIG_FAULT_INJECTION 1300 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1301 size_t count, loff_t *ppos) 1302 { 1303 struct task_struct *task = get_proc_task(file_inode(file)); 1304 char buffer[PROC_NUMBUF]; 1305 size_t len; 1306 int make_it_fail; 1307 1308 if (!task) 1309 return -ESRCH; 1310 make_it_fail = task->make_it_fail; 1311 put_task_struct(task); 1312 1313 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1314 1315 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1316 } 1317 1318 static ssize_t proc_fault_inject_write(struct file * file, 1319 const char __user * buf, size_t count, loff_t *ppos) 1320 { 1321 struct task_struct *task; 1322 char buffer[PROC_NUMBUF]; 1323 int make_it_fail; 1324 int rv; 1325 1326 if (!capable(CAP_SYS_RESOURCE)) 1327 return -EPERM; 1328 memset(buffer, 0, sizeof(buffer)); 1329 if (count > sizeof(buffer) - 1) 1330 count = sizeof(buffer) - 1; 1331 if (copy_from_user(buffer, buf, count)) 1332 return -EFAULT; 1333 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail); 1334 if (rv < 0) 1335 return rv; 1336 if (make_it_fail < 0 || make_it_fail > 1) 1337 return -EINVAL; 1338 1339 task = get_proc_task(file_inode(file)); 1340 if (!task) 1341 return -ESRCH; 1342 task->make_it_fail = make_it_fail; 1343 put_task_struct(task); 1344 1345 return count; 1346 } 1347 1348 static const struct file_operations proc_fault_inject_operations = { 1349 .read = proc_fault_inject_read, 1350 .write = proc_fault_inject_write, 1351 .llseek = generic_file_llseek, 1352 }; 1353 1354 static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf, 1355 size_t count, loff_t *ppos) 1356 { 1357 struct task_struct *task; 1358 int err; 1359 unsigned int n; 1360 1361 err = kstrtouint_from_user(buf, count, 0, &n); 1362 if (err) 1363 return err; 1364 1365 task = get_proc_task(file_inode(file)); 1366 if (!task) 1367 return -ESRCH; 1368 task->fail_nth = n; 1369 put_task_struct(task); 1370 1371 return count; 1372 } 1373 1374 static ssize_t proc_fail_nth_read(struct file *file, char __user *buf, 1375 size_t count, loff_t *ppos) 1376 { 1377 struct task_struct *task; 1378 char numbuf[PROC_NUMBUF]; 1379 ssize_t len; 1380 1381 task = get_proc_task(file_inode(file)); 1382 if (!task) 1383 return -ESRCH; 1384 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth); 1385 put_task_struct(task); 1386 return simple_read_from_buffer(buf, count, ppos, numbuf, len); 1387 } 1388 1389 static const struct file_operations proc_fail_nth_operations = { 1390 .read = proc_fail_nth_read, 1391 .write = proc_fail_nth_write, 1392 }; 1393 #endif 1394 1395 1396 #ifdef CONFIG_SCHED_DEBUG 1397 /* 1398 * Print out various scheduling related per-task fields: 1399 */ 1400 static int sched_show(struct seq_file *m, void *v) 1401 { 1402 struct inode *inode = m->private; 1403 struct pid_namespace *ns = proc_pid_ns(inode); 1404 struct task_struct *p; 1405 1406 p = get_proc_task(inode); 1407 if (!p) 1408 return -ESRCH; 1409 proc_sched_show_task(p, ns, m); 1410 1411 put_task_struct(p); 1412 1413 return 0; 1414 } 1415 1416 static ssize_t 1417 sched_write(struct file *file, const char __user *buf, 1418 size_t count, loff_t *offset) 1419 { 1420 struct inode *inode = file_inode(file); 1421 struct task_struct *p; 1422 1423 p = get_proc_task(inode); 1424 if (!p) 1425 return -ESRCH; 1426 proc_sched_set_task(p); 1427 1428 put_task_struct(p); 1429 1430 return count; 1431 } 1432 1433 static int sched_open(struct inode *inode, struct file *filp) 1434 { 1435 return single_open(filp, sched_show, inode); 1436 } 1437 1438 static const struct file_operations proc_pid_sched_operations = { 1439 .open = sched_open, 1440 .read = seq_read, 1441 .write = sched_write, 1442 .llseek = seq_lseek, 1443 .release = single_release, 1444 }; 1445 1446 #endif 1447 1448 #ifdef CONFIG_SCHED_AUTOGROUP 1449 /* 1450 * Print out autogroup related information: 1451 */ 1452 static int sched_autogroup_show(struct seq_file *m, void *v) 1453 { 1454 struct inode *inode = m->private; 1455 struct task_struct *p; 1456 1457 p = get_proc_task(inode); 1458 if (!p) 1459 return -ESRCH; 1460 proc_sched_autogroup_show_task(p, m); 1461 1462 put_task_struct(p); 1463 1464 return 0; 1465 } 1466 1467 static ssize_t 1468 sched_autogroup_write(struct file *file, const char __user *buf, 1469 size_t count, loff_t *offset) 1470 { 1471 struct inode *inode = file_inode(file); 1472 struct task_struct *p; 1473 char buffer[PROC_NUMBUF]; 1474 int nice; 1475 int err; 1476 1477 memset(buffer, 0, sizeof(buffer)); 1478 if (count > sizeof(buffer) - 1) 1479 count = sizeof(buffer) - 1; 1480 if (copy_from_user(buffer, buf, count)) 1481 return -EFAULT; 1482 1483 err = kstrtoint(strstrip(buffer), 0, &nice); 1484 if (err < 0) 1485 return err; 1486 1487 p = get_proc_task(inode); 1488 if (!p) 1489 return -ESRCH; 1490 1491 err = proc_sched_autogroup_set_nice(p, nice); 1492 if (err) 1493 count = err; 1494 1495 put_task_struct(p); 1496 1497 return count; 1498 } 1499 1500 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1501 { 1502 int ret; 1503 1504 ret = single_open(filp, sched_autogroup_show, NULL); 1505 if (!ret) { 1506 struct seq_file *m = filp->private_data; 1507 1508 m->private = inode; 1509 } 1510 return ret; 1511 } 1512 1513 static const struct file_operations proc_pid_sched_autogroup_operations = { 1514 .open = sched_autogroup_open, 1515 .read = seq_read, 1516 .write = sched_autogroup_write, 1517 .llseek = seq_lseek, 1518 .release = single_release, 1519 }; 1520 1521 #endif /* CONFIG_SCHED_AUTOGROUP */ 1522 1523 static ssize_t comm_write(struct file *file, const char __user *buf, 1524 size_t count, loff_t *offset) 1525 { 1526 struct inode *inode = file_inode(file); 1527 struct task_struct *p; 1528 char buffer[TASK_COMM_LEN]; 1529 const size_t maxlen = sizeof(buffer) - 1; 1530 1531 memset(buffer, 0, sizeof(buffer)); 1532 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count)) 1533 return -EFAULT; 1534 1535 p = get_proc_task(inode); 1536 if (!p) 1537 return -ESRCH; 1538 1539 if (same_thread_group(current, p)) 1540 set_task_comm(p, buffer); 1541 else 1542 count = -EINVAL; 1543 1544 put_task_struct(p); 1545 1546 return count; 1547 } 1548 1549 static int comm_show(struct seq_file *m, void *v) 1550 { 1551 struct inode *inode = m->private; 1552 struct task_struct *p; 1553 1554 p = get_proc_task(inode); 1555 if (!p) 1556 return -ESRCH; 1557 1558 proc_task_name(m, p, false); 1559 seq_putc(m, '\n'); 1560 1561 put_task_struct(p); 1562 1563 return 0; 1564 } 1565 1566 static int comm_open(struct inode *inode, struct file *filp) 1567 { 1568 return single_open(filp, comm_show, inode); 1569 } 1570 1571 static const struct file_operations proc_pid_set_comm_operations = { 1572 .open = comm_open, 1573 .read = seq_read, 1574 .write = comm_write, 1575 .llseek = seq_lseek, 1576 .release = single_release, 1577 }; 1578 1579 static int proc_exe_link(struct dentry *dentry, struct path *exe_path) 1580 { 1581 struct task_struct *task; 1582 struct file *exe_file; 1583 1584 task = get_proc_task(d_inode(dentry)); 1585 if (!task) 1586 return -ENOENT; 1587 exe_file = get_task_exe_file(task); 1588 put_task_struct(task); 1589 if (exe_file) { 1590 *exe_path = exe_file->f_path; 1591 path_get(&exe_file->f_path); 1592 fput(exe_file); 1593 return 0; 1594 } else 1595 return -ENOENT; 1596 } 1597 1598 static const char *proc_pid_get_link(struct dentry *dentry, 1599 struct inode *inode, 1600 struct delayed_call *done) 1601 { 1602 struct path path; 1603 int error = -EACCES; 1604 1605 if (!dentry) 1606 return ERR_PTR(-ECHILD); 1607 1608 /* Are we allowed to snoop on the tasks file descriptors? */ 1609 if (!proc_fd_access_allowed(inode)) 1610 goto out; 1611 1612 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1613 if (error) 1614 goto out; 1615 1616 nd_jump_link(&path); 1617 return NULL; 1618 out: 1619 return ERR_PTR(error); 1620 } 1621 1622 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1623 { 1624 char *tmp = (char *)__get_free_page(GFP_KERNEL); 1625 char *pathname; 1626 int len; 1627 1628 if (!tmp) 1629 return -ENOMEM; 1630 1631 pathname = d_path(path, tmp, PAGE_SIZE); 1632 len = PTR_ERR(pathname); 1633 if (IS_ERR(pathname)) 1634 goto out; 1635 len = tmp + PAGE_SIZE - 1 - pathname; 1636 1637 if (len > buflen) 1638 len = buflen; 1639 if (copy_to_user(buffer, pathname, len)) 1640 len = -EFAULT; 1641 out: 1642 free_page((unsigned long)tmp); 1643 return len; 1644 } 1645 1646 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1647 { 1648 int error = -EACCES; 1649 struct inode *inode = d_inode(dentry); 1650 struct path path; 1651 1652 /* Are we allowed to snoop on the tasks file descriptors? */ 1653 if (!proc_fd_access_allowed(inode)) 1654 goto out; 1655 1656 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1657 if (error) 1658 goto out; 1659 1660 error = do_proc_readlink(&path, buffer, buflen); 1661 path_put(&path); 1662 out: 1663 return error; 1664 } 1665 1666 const struct inode_operations proc_pid_link_inode_operations = { 1667 .readlink = proc_pid_readlink, 1668 .get_link = proc_pid_get_link, 1669 .setattr = proc_setattr, 1670 }; 1671 1672 1673 /* building an inode */ 1674 1675 void task_dump_owner(struct task_struct *task, umode_t mode, 1676 kuid_t *ruid, kgid_t *rgid) 1677 { 1678 /* Depending on the state of dumpable compute who should own a 1679 * proc file for a task. 1680 */ 1681 const struct cred *cred; 1682 kuid_t uid; 1683 kgid_t gid; 1684 1685 if (unlikely(task->flags & PF_KTHREAD)) { 1686 *ruid = GLOBAL_ROOT_UID; 1687 *rgid = GLOBAL_ROOT_GID; 1688 return; 1689 } 1690 1691 /* Default to the tasks effective ownership */ 1692 rcu_read_lock(); 1693 cred = __task_cred(task); 1694 uid = cred->euid; 1695 gid = cred->egid; 1696 rcu_read_unlock(); 1697 1698 /* 1699 * Before the /proc/pid/status file was created the only way to read 1700 * the effective uid of a /process was to stat /proc/pid. Reading 1701 * /proc/pid/status is slow enough that procps and other packages 1702 * kept stating /proc/pid. To keep the rules in /proc simple I have 1703 * made this apply to all per process world readable and executable 1704 * directories. 1705 */ 1706 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) { 1707 struct mm_struct *mm; 1708 task_lock(task); 1709 mm = task->mm; 1710 /* Make non-dumpable tasks owned by some root */ 1711 if (mm) { 1712 if (get_dumpable(mm) != SUID_DUMP_USER) { 1713 struct user_namespace *user_ns = mm->user_ns; 1714 1715 uid = make_kuid(user_ns, 0); 1716 if (!uid_valid(uid)) 1717 uid = GLOBAL_ROOT_UID; 1718 1719 gid = make_kgid(user_ns, 0); 1720 if (!gid_valid(gid)) 1721 gid = GLOBAL_ROOT_GID; 1722 } 1723 } else { 1724 uid = GLOBAL_ROOT_UID; 1725 gid = GLOBAL_ROOT_GID; 1726 } 1727 task_unlock(task); 1728 } 1729 *ruid = uid; 1730 *rgid = gid; 1731 } 1732 1733 struct inode *proc_pid_make_inode(struct super_block * sb, 1734 struct task_struct *task, umode_t mode) 1735 { 1736 struct inode * inode; 1737 struct proc_inode *ei; 1738 1739 /* We need a new inode */ 1740 1741 inode = new_inode(sb); 1742 if (!inode) 1743 goto out; 1744 1745 /* Common stuff */ 1746 ei = PROC_I(inode); 1747 inode->i_mode = mode; 1748 inode->i_ino = get_next_ino(); 1749 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 1750 inode->i_op = &proc_def_inode_operations; 1751 1752 /* 1753 * grab the reference to task. 1754 */ 1755 ei->pid = get_task_pid(task, PIDTYPE_PID); 1756 if (!ei->pid) 1757 goto out_unlock; 1758 1759 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); 1760 security_task_to_inode(task, inode); 1761 1762 out: 1763 return inode; 1764 1765 out_unlock: 1766 iput(inode); 1767 return NULL; 1768 } 1769 1770 int pid_getattr(const struct path *path, struct kstat *stat, 1771 u32 request_mask, unsigned int query_flags) 1772 { 1773 struct inode *inode = d_inode(path->dentry); 1774 struct pid_namespace *pid = proc_pid_ns(inode); 1775 struct task_struct *task; 1776 1777 generic_fillattr(inode, stat); 1778 1779 stat->uid = GLOBAL_ROOT_UID; 1780 stat->gid = GLOBAL_ROOT_GID; 1781 rcu_read_lock(); 1782 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1783 if (task) { 1784 if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) { 1785 rcu_read_unlock(); 1786 /* 1787 * This doesn't prevent learning whether PID exists, 1788 * it only makes getattr() consistent with readdir(). 1789 */ 1790 return -ENOENT; 1791 } 1792 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid); 1793 } 1794 rcu_read_unlock(); 1795 return 0; 1796 } 1797 1798 /* dentry stuff */ 1799 1800 /* 1801 * Set <pid>/... inode ownership (can change due to setuid(), etc.) 1802 */ 1803 void pid_update_inode(struct task_struct *task, struct inode *inode) 1804 { 1805 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid); 1806 1807 inode->i_mode &= ~(S_ISUID | S_ISGID); 1808 security_task_to_inode(task, inode); 1809 } 1810 1811 /* 1812 * Rewrite the inode's ownerships here because the owning task may have 1813 * performed a setuid(), etc. 1814 * 1815 */ 1816 static int pid_revalidate(struct dentry *dentry, unsigned int flags) 1817 { 1818 struct inode *inode; 1819 struct task_struct *task; 1820 1821 if (flags & LOOKUP_RCU) 1822 return -ECHILD; 1823 1824 inode = d_inode(dentry); 1825 task = get_proc_task(inode); 1826 1827 if (task) { 1828 pid_update_inode(task, inode); 1829 put_task_struct(task); 1830 return 1; 1831 } 1832 return 0; 1833 } 1834 1835 static inline bool proc_inode_is_dead(struct inode *inode) 1836 { 1837 return !proc_pid(inode)->tasks[PIDTYPE_PID].first; 1838 } 1839 1840 int pid_delete_dentry(const struct dentry *dentry) 1841 { 1842 /* Is the task we represent dead? 1843 * If so, then don't put the dentry on the lru list, 1844 * kill it immediately. 1845 */ 1846 return proc_inode_is_dead(d_inode(dentry)); 1847 } 1848 1849 const struct dentry_operations pid_dentry_operations = 1850 { 1851 .d_revalidate = pid_revalidate, 1852 .d_delete = pid_delete_dentry, 1853 }; 1854 1855 /* Lookups */ 1856 1857 /* 1858 * Fill a directory entry. 1859 * 1860 * If possible create the dcache entry and derive our inode number and 1861 * file type from dcache entry. 1862 * 1863 * Since all of the proc inode numbers are dynamically generated, the inode 1864 * numbers do not exist until the inode is cache. This means creating the 1865 * the dcache entry in readdir is necessary to keep the inode numbers 1866 * reported by readdir in sync with the inode numbers reported 1867 * by stat. 1868 */ 1869 bool proc_fill_cache(struct file *file, struct dir_context *ctx, 1870 const char *name, unsigned int len, 1871 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1872 { 1873 struct dentry *child, *dir = file->f_path.dentry; 1874 struct qstr qname = QSTR_INIT(name, len); 1875 struct inode *inode; 1876 unsigned type = DT_UNKNOWN; 1877 ino_t ino = 1; 1878 1879 child = d_hash_and_lookup(dir, &qname); 1880 if (!child) { 1881 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 1882 child = d_alloc_parallel(dir, &qname, &wq); 1883 if (IS_ERR(child)) 1884 goto end_instantiate; 1885 if (d_in_lookup(child)) { 1886 struct dentry *res; 1887 res = instantiate(child, task, ptr); 1888 d_lookup_done(child); 1889 if (unlikely(res)) { 1890 dput(child); 1891 child = res; 1892 if (IS_ERR(child)) 1893 goto end_instantiate; 1894 } 1895 } 1896 } 1897 inode = d_inode(child); 1898 ino = inode->i_ino; 1899 type = inode->i_mode >> 12; 1900 dput(child); 1901 end_instantiate: 1902 return dir_emit(ctx, name, len, ino, type); 1903 } 1904 1905 /* 1906 * dname_to_vma_addr - maps a dentry name into two unsigned longs 1907 * which represent vma start and end addresses. 1908 */ 1909 static int dname_to_vma_addr(struct dentry *dentry, 1910 unsigned long *start, unsigned long *end) 1911 { 1912 const char *str = dentry->d_name.name; 1913 unsigned long long sval, eval; 1914 unsigned int len; 1915 1916 if (str[0] == '0' && str[1] != '-') 1917 return -EINVAL; 1918 len = _parse_integer(str, 16, &sval); 1919 if (len & KSTRTOX_OVERFLOW) 1920 return -EINVAL; 1921 if (sval != (unsigned long)sval) 1922 return -EINVAL; 1923 str += len; 1924 1925 if (*str != '-') 1926 return -EINVAL; 1927 str++; 1928 1929 if (str[0] == '0' && str[1]) 1930 return -EINVAL; 1931 len = _parse_integer(str, 16, &eval); 1932 if (len & KSTRTOX_OVERFLOW) 1933 return -EINVAL; 1934 if (eval != (unsigned long)eval) 1935 return -EINVAL; 1936 str += len; 1937 1938 if (*str != '\0') 1939 return -EINVAL; 1940 1941 *start = sval; 1942 *end = eval; 1943 1944 return 0; 1945 } 1946 1947 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags) 1948 { 1949 unsigned long vm_start, vm_end; 1950 bool exact_vma_exists = false; 1951 struct mm_struct *mm = NULL; 1952 struct task_struct *task; 1953 struct inode *inode; 1954 int status = 0; 1955 1956 if (flags & LOOKUP_RCU) 1957 return -ECHILD; 1958 1959 inode = d_inode(dentry); 1960 task = get_proc_task(inode); 1961 if (!task) 1962 goto out_notask; 1963 1964 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); 1965 if (IS_ERR_OR_NULL(mm)) 1966 goto out; 1967 1968 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 1969 down_read(&mm->mmap_sem); 1970 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end); 1971 up_read(&mm->mmap_sem); 1972 } 1973 1974 mmput(mm); 1975 1976 if (exact_vma_exists) { 1977 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); 1978 1979 security_task_to_inode(task, inode); 1980 status = 1; 1981 } 1982 1983 out: 1984 put_task_struct(task); 1985 1986 out_notask: 1987 return status; 1988 } 1989 1990 static const struct dentry_operations tid_map_files_dentry_operations = { 1991 .d_revalidate = map_files_d_revalidate, 1992 .d_delete = pid_delete_dentry, 1993 }; 1994 1995 static int map_files_get_link(struct dentry *dentry, struct path *path) 1996 { 1997 unsigned long vm_start, vm_end; 1998 struct vm_area_struct *vma; 1999 struct task_struct *task; 2000 struct mm_struct *mm; 2001 int rc; 2002 2003 rc = -ENOENT; 2004 task = get_proc_task(d_inode(dentry)); 2005 if (!task) 2006 goto out; 2007 2008 mm = get_task_mm(task); 2009 put_task_struct(task); 2010 if (!mm) 2011 goto out; 2012 2013 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 2014 if (rc) 2015 goto out_mmput; 2016 2017 rc = -ENOENT; 2018 down_read(&mm->mmap_sem); 2019 vma = find_exact_vma(mm, vm_start, vm_end); 2020 if (vma && vma->vm_file) { 2021 *path = vma->vm_file->f_path; 2022 path_get(path); 2023 rc = 0; 2024 } 2025 up_read(&mm->mmap_sem); 2026 2027 out_mmput: 2028 mmput(mm); 2029 out: 2030 return rc; 2031 } 2032 2033 struct map_files_info { 2034 unsigned long start; 2035 unsigned long end; 2036 fmode_t mode; 2037 }; 2038 2039 /* 2040 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the 2041 * symlinks may be used to bypass permissions on ancestor directories in the 2042 * path to the file in question. 2043 */ 2044 static const char * 2045 proc_map_files_get_link(struct dentry *dentry, 2046 struct inode *inode, 2047 struct delayed_call *done) 2048 { 2049 if (!capable(CAP_SYS_ADMIN)) 2050 return ERR_PTR(-EPERM); 2051 2052 return proc_pid_get_link(dentry, inode, done); 2053 } 2054 2055 /* 2056 * Identical to proc_pid_link_inode_operations except for get_link() 2057 */ 2058 static const struct inode_operations proc_map_files_link_inode_operations = { 2059 .readlink = proc_pid_readlink, 2060 .get_link = proc_map_files_get_link, 2061 .setattr = proc_setattr, 2062 }; 2063 2064 static struct dentry * 2065 proc_map_files_instantiate(struct dentry *dentry, 2066 struct task_struct *task, const void *ptr) 2067 { 2068 fmode_t mode = (fmode_t)(unsigned long)ptr; 2069 struct proc_inode *ei; 2070 struct inode *inode; 2071 2072 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK | 2073 ((mode & FMODE_READ ) ? S_IRUSR : 0) | 2074 ((mode & FMODE_WRITE) ? S_IWUSR : 0)); 2075 if (!inode) 2076 return ERR_PTR(-ENOENT); 2077 2078 ei = PROC_I(inode); 2079 ei->op.proc_get_link = map_files_get_link; 2080 2081 inode->i_op = &proc_map_files_link_inode_operations; 2082 inode->i_size = 64; 2083 2084 d_set_d_op(dentry, &tid_map_files_dentry_operations); 2085 return d_splice_alias(inode, dentry); 2086 } 2087 2088 static struct dentry *proc_map_files_lookup(struct inode *dir, 2089 struct dentry *dentry, unsigned int flags) 2090 { 2091 unsigned long vm_start, vm_end; 2092 struct vm_area_struct *vma; 2093 struct task_struct *task; 2094 struct dentry *result; 2095 struct mm_struct *mm; 2096 2097 result = ERR_PTR(-ENOENT); 2098 task = get_proc_task(dir); 2099 if (!task) 2100 goto out; 2101 2102 result = ERR_PTR(-EACCES); 2103 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2104 goto out_put_task; 2105 2106 result = ERR_PTR(-ENOENT); 2107 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 2108 goto out_put_task; 2109 2110 mm = get_task_mm(task); 2111 if (!mm) 2112 goto out_put_task; 2113 2114 down_read(&mm->mmap_sem); 2115 vma = find_exact_vma(mm, vm_start, vm_end); 2116 if (!vma) 2117 goto out_no_vma; 2118 2119 if (vma->vm_file) 2120 result = proc_map_files_instantiate(dentry, task, 2121 (void *)(unsigned long)vma->vm_file->f_mode); 2122 2123 out_no_vma: 2124 up_read(&mm->mmap_sem); 2125 mmput(mm); 2126 out_put_task: 2127 put_task_struct(task); 2128 out: 2129 return result; 2130 } 2131 2132 static const struct inode_operations proc_map_files_inode_operations = { 2133 .lookup = proc_map_files_lookup, 2134 .permission = proc_fd_permission, 2135 .setattr = proc_setattr, 2136 }; 2137 2138 static int 2139 proc_map_files_readdir(struct file *file, struct dir_context *ctx) 2140 { 2141 struct vm_area_struct *vma; 2142 struct task_struct *task; 2143 struct mm_struct *mm; 2144 unsigned long nr_files, pos, i; 2145 struct flex_array *fa = NULL; 2146 struct map_files_info info; 2147 struct map_files_info *p; 2148 int ret; 2149 2150 ret = -ENOENT; 2151 task = get_proc_task(file_inode(file)); 2152 if (!task) 2153 goto out; 2154 2155 ret = -EACCES; 2156 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2157 goto out_put_task; 2158 2159 ret = 0; 2160 if (!dir_emit_dots(file, ctx)) 2161 goto out_put_task; 2162 2163 mm = get_task_mm(task); 2164 if (!mm) 2165 goto out_put_task; 2166 down_read(&mm->mmap_sem); 2167 2168 nr_files = 0; 2169 2170 /* 2171 * We need two passes here: 2172 * 2173 * 1) Collect vmas of mapped files with mmap_sem taken 2174 * 2) Release mmap_sem and instantiate entries 2175 * 2176 * otherwise we get lockdep complained, since filldir() 2177 * routine might require mmap_sem taken in might_fault(). 2178 */ 2179 2180 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 2181 if (vma->vm_file && ++pos > ctx->pos) 2182 nr_files++; 2183 } 2184 2185 if (nr_files) { 2186 fa = flex_array_alloc(sizeof(info), nr_files, 2187 GFP_KERNEL); 2188 if (!fa || flex_array_prealloc(fa, 0, nr_files, 2189 GFP_KERNEL)) { 2190 ret = -ENOMEM; 2191 if (fa) 2192 flex_array_free(fa); 2193 up_read(&mm->mmap_sem); 2194 mmput(mm); 2195 goto out_put_task; 2196 } 2197 for (i = 0, vma = mm->mmap, pos = 2; vma; 2198 vma = vma->vm_next) { 2199 if (!vma->vm_file) 2200 continue; 2201 if (++pos <= ctx->pos) 2202 continue; 2203 2204 info.start = vma->vm_start; 2205 info.end = vma->vm_end; 2206 info.mode = vma->vm_file->f_mode; 2207 if (flex_array_put(fa, i++, &info, GFP_KERNEL)) 2208 BUG(); 2209 } 2210 } 2211 up_read(&mm->mmap_sem); 2212 mmput(mm); 2213 2214 for (i = 0; i < nr_files; i++) { 2215 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */ 2216 unsigned int len; 2217 2218 p = flex_array_get(fa, i); 2219 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end); 2220 if (!proc_fill_cache(file, ctx, 2221 buf, len, 2222 proc_map_files_instantiate, 2223 task, 2224 (void *)(unsigned long)p->mode)) 2225 break; 2226 ctx->pos++; 2227 } 2228 if (fa) 2229 flex_array_free(fa); 2230 2231 out_put_task: 2232 put_task_struct(task); 2233 out: 2234 return ret; 2235 } 2236 2237 static const struct file_operations proc_map_files_operations = { 2238 .read = generic_read_dir, 2239 .iterate_shared = proc_map_files_readdir, 2240 .llseek = generic_file_llseek, 2241 }; 2242 2243 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS) 2244 struct timers_private { 2245 struct pid *pid; 2246 struct task_struct *task; 2247 struct sighand_struct *sighand; 2248 struct pid_namespace *ns; 2249 unsigned long flags; 2250 }; 2251 2252 static void *timers_start(struct seq_file *m, loff_t *pos) 2253 { 2254 struct timers_private *tp = m->private; 2255 2256 tp->task = get_pid_task(tp->pid, PIDTYPE_PID); 2257 if (!tp->task) 2258 return ERR_PTR(-ESRCH); 2259 2260 tp->sighand = lock_task_sighand(tp->task, &tp->flags); 2261 if (!tp->sighand) 2262 return ERR_PTR(-ESRCH); 2263 2264 return seq_list_start(&tp->task->signal->posix_timers, *pos); 2265 } 2266 2267 static void *timers_next(struct seq_file *m, void *v, loff_t *pos) 2268 { 2269 struct timers_private *tp = m->private; 2270 return seq_list_next(v, &tp->task->signal->posix_timers, pos); 2271 } 2272 2273 static void timers_stop(struct seq_file *m, void *v) 2274 { 2275 struct timers_private *tp = m->private; 2276 2277 if (tp->sighand) { 2278 unlock_task_sighand(tp->task, &tp->flags); 2279 tp->sighand = NULL; 2280 } 2281 2282 if (tp->task) { 2283 put_task_struct(tp->task); 2284 tp->task = NULL; 2285 } 2286 } 2287 2288 static int show_timer(struct seq_file *m, void *v) 2289 { 2290 struct k_itimer *timer; 2291 struct timers_private *tp = m->private; 2292 int notify; 2293 static const char * const nstr[] = { 2294 [SIGEV_SIGNAL] = "signal", 2295 [SIGEV_NONE] = "none", 2296 [SIGEV_THREAD] = "thread", 2297 }; 2298 2299 timer = list_entry((struct list_head *)v, struct k_itimer, list); 2300 notify = timer->it_sigev_notify; 2301 2302 seq_printf(m, "ID: %d\n", timer->it_id); 2303 seq_printf(m, "signal: %d/%px\n", 2304 timer->sigq->info.si_signo, 2305 timer->sigq->info.si_value.sival_ptr); 2306 seq_printf(m, "notify: %s/%s.%d\n", 2307 nstr[notify & ~SIGEV_THREAD_ID], 2308 (notify & SIGEV_THREAD_ID) ? "tid" : "pid", 2309 pid_nr_ns(timer->it_pid, tp->ns)); 2310 seq_printf(m, "ClockID: %d\n", timer->it_clock); 2311 2312 return 0; 2313 } 2314 2315 static const struct seq_operations proc_timers_seq_ops = { 2316 .start = timers_start, 2317 .next = timers_next, 2318 .stop = timers_stop, 2319 .show = show_timer, 2320 }; 2321 2322 static int proc_timers_open(struct inode *inode, struct file *file) 2323 { 2324 struct timers_private *tp; 2325 2326 tp = __seq_open_private(file, &proc_timers_seq_ops, 2327 sizeof(struct timers_private)); 2328 if (!tp) 2329 return -ENOMEM; 2330 2331 tp->pid = proc_pid(inode); 2332 tp->ns = proc_pid_ns(inode); 2333 return 0; 2334 } 2335 2336 static const struct file_operations proc_timers_operations = { 2337 .open = proc_timers_open, 2338 .read = seq_read, 2339 .llseek = seq_lseek, 2340 .release = seq_release_private, 2341 }; 2342 #endif 2343 2344 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf, 2345 size_t count, loff_t *offset) 2346 { 2347 struct inode *inode = file_inode(file); 2348 struct task_struct *p; 2349 u64 slack_ns; 2350 int err; 2351 2352 err = kstrtoull_from_user(buf, count, 10, &slack_ns); 2353 if (err < 0) 2354 return err; 2355 2356 p = get_proc_task(inode); 2357 if (!p) 2358 return -ESRCH; 2359 2360 if (p != current) { 2361 rcu_read_lock(); 2362 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { 2363 rcu_read_unlock(); 2364 count = -EPERM; 2365 goto out; 2366 } 2367 rcu_read_unlock(); 2368 2369 err = security_task_setscheduler(p); 2370 if (err) { 2371 count = err; 2372 goto out; 2373 } 2374 } 2375 2376 task_lock(p); 2377 if (slack_ns == 0) 2378 p->timer_slack_ns = p->default_timer_slack_ns; 2379 else 2380 p->timer_slack_ns = slack_ns; 2381 task_unlock(p); 2382 2383 out: 2384 put_task_struct(p); 2385 2386 return count; 2387 } 2388 2389 static int timerslack_ns_show(struct seq_file *m, void *v) 2390 { 2391 struct inode *inode = m->private; 2392 struct task_struct *p; 2393 int err = 0; 2394 2395 p = get_proc_task(inode); 2396 if (!p) 2397 return -ESRCH; 2398 2399 if (p != current) { 2400 rcu_read_lock(); 2401 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { 2402 rcu_read_unlock(); 2403 err = -EPERM; 2404 goto out; 2405 } 2406 rcu_read_unlock(); 2407 2408 err = security_task_getscheduler(p); 2409 if (err) 2410 goto out; 2411 } 2412 2413 task_lock(p); 2414 seq_printf(m, "%llu\n", p->timer_slack_ns); 2415 task_unlock(p); 2416 2417 out: 2418 put_task_struct(p); 2419 2420 return err; 2421 } 2422 2423 static int timerslack_ns_open(struct inode *inode, struct file *filp) 2424 { 2425 return single_open(filp, timerslack_ns_show, inode); 2426 } 2427 2428 static const struct file_operations proc_pid_set_timerslack_ns_operations = { 2429 .open = timerslack_ns_open, 2430 .read = seq_read, 2431 .write = timerslack_ns_write, 2432 .llseek = seq_lseek, 2433 .release = single_release, 2434 }; 2435 2436 static struct dentry *proc_pident_instantiate(struct dentry *dentry, 2437 struct task_struct *task, const void *ptr) 2438 { 2439 const struct pid_entry *p = ptr; 2440 struct inode *inode; 2441 struct proc_inode *ei; 2442 2443 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode); 2444 if (!inode) 2445 return ERR_PTR(-ENOENT); 2446 2447 ei = PROC_I(inode); 2448 if (S_ISDIR(inode->i_mode)) 2449 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2450 if (p->iop) 2451 inode->i_op = p->iop; 2452 if (p->fop) 2453 inode->i_fop = p->fop; 2454 ei->op = p->op; 2455 pid_update_inode(task, inode); 2456 d_set_d_op(dentry, &pid_dentry_operations); 2457 return d_splice_alias(inode, dentry); 2458 } 2459 2460 static struct dentry *proc_pident_lookup(struct inode *dir, 2461 struct dentry *dentry, 2462 const struct pid_entry *ents, 2463 unsigned int nents) 2464 { 2465 struct task_struct *task = get_proc_task(dir); 2466 const struct pid_entry *p, *last; 2467 struct dentry *res = ERR_PTR(-ENOENT); 2468 2469 if (!task) 2470 goto out_no_task; 2471 2472 /* 2473 * Yes, it does not scale. And it should not. Don't add 2474 * new entries into /proc/<tgid>/ without very good reasons. 2475 */ 2476 last = &ents[nents]; 2477 for (p = ents; p < last; p++) { 2478 if (p->len != dentry->d_name.len) 2479 continue; 2480 if (!memcmp(dentry->d_name.name, p->name, p->len)) { 2481 res = proc_pident_instantiate(dentry, task, p); 2482 break; 2483 } 2484 } 2485 put_task_struct(task); 2486 out_no_task: 2487 return res; 2488 } 2489 2490 static int proc_pident_readdir(struct file *file, struct dir_context *ctx, 2491 const struct pid_entry *ents, unsigned int nents) 2492 { 2493 struct task_struct *task = get_proc_task(file_inode(file)); 2494 const struct pid_entry *p; 2495 2496 if (!task) 2497 return -ENOENT; 2498 2499 if (!dir_emit_dots(file, ctx)) 2500 goto out; 2501 2502 if (ctx->pos >= nents + 2) 2503 goto out; 2504 2505 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) { 2506 if (!proc_fill_cache(file, ctx, p->name, p->len, 2507 proc_pident_instantiate, task, p)) 2508 break; 2509 ctx->pos++; 2510 } 2511 out: 2512 put_task_struct(task); 2513 return 0; 2514 } 2515 2516 #ifdef CONFIG_SECURITY 2517 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2518 size_t count, loff_t *ppos) 2519 { 2520 struct inode * inode = file_inode(file); 2521 char *p = NULL; 2522 ssize_t length; 2523 struct task_struct *task = get_proc_task(inode); 2524 2525 if (!task) 2526 return -ESRCH; 2527 2528 length = security_getprocattr(task, 2529 (char*)file->f_path.dentry->d_name.name, 2530 &p); 2531 put_task_struct(task); 2532 if (length > 0) 2533 length = simple_read_from_buffer(buf, count, ppos, p, length); 2534 kfree(p); 2535 return length; 2536 } 2537 2538 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2539 size_t count, loff_t *ppos) 2540 { 2541 struct inode * inode = file_inode(file); 2542 struct task_struct *task; 2543 void *page; 2544 int rv; 2545 2546 rcu_read_lock(); 2547 task = pid_task(proc_pid(inode), PIDTYPE_PID); 2548 if (!task) { 2549 rcu_read_unlock(); 2550 return -ESRCH; 2551 } 2552 /* A task may only write its own attributes. */ 2553 if (current != task) { 2554 rcu_read_unlock(); 2555 return -EACCES; 2556 } 2557 rcu_read_unlock(); 2558 2559 if (count > PAGE_SIZE) 2560 count = PAGE_SIZE; 2561 2562 /* No partial writes. */ 2563 if (*ppos != 0) 2564 return -EINVAL; 2565 2566 page = memdup_user(buf, count); 2567 if (IS_ERR(page)) { 2568 rv = PTR_ERR(page); 2569 goto out; 2570 } 2571 2572 /* Guard against adverse ptrace interaction */ 2573 rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex); 2574 if (rv < 0) 2575 goto out_free; 2576 2577 rv = security_setprocattr(file->f_path.dentry->d_name.name, page, count); 2578 mutex_unlock(¤t->signal->cred_guard_mutex); 2579 out_free: 2580 kfree(page); 2581 out: 2582 return rv; 2583 } 2584 2585 static const struct file_operations proc_pid_attr_operations = { 2586 .read = proc_pid_attr_read, 2587 .write = proc_pid_attr_write, 2588 .llseek = generic_file_llseek, 2589 }; 2590 2591 static const struct pid_entry attr_dir_stuff[] = { 2592 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2593 REG("prev", S_IRUGO, proc_pid_attr_operations), 2594 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2595 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2596 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2597 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2598 }; 2599 2600 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx) 2601 { 2602 return proc_pident_readdir(file, ctx, 2603 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2604 } 2605 2606 static const struct file_operations proc_attr_dir_operations = { 2607 .read = generic_read_dir, 2608 .iterate_shared = proc_attr_dir_readdir, 2609 .llseek = generic_file_llseek, 2610 }; 2611 2612 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2613 struct dentry *dentry, unsigned int flags) 2614 { 2615 return proc_pident_lookup(dir, dentry, 2616 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2617 } 2618 2619 static const struct inode_operations proc_attr_dir_inode_operations = { 2620 .lookup = proc_attr_dir_lookup, 2621 .getattr = pid_getattr, 2622 .setattr = proc_setattr, 2623 }; 2624 2625 #endif 2626 2627 #ifdef CONFIG_ELF_CORE 2628 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2629 size_t count, loff_t *ppos) 2630 { 2631 struct task_struct *task = get_proc_task(file_inode(file)); 2632 struct mm_struct *mm; 2633 char buffer[PROC_NUMBUF]; 2634 size_t len; 2635 int ret; 2636 2637 if (!task) 2638 return -ESRCH; 2639 2640 ret = 0; 2641 mm = get_task_mm(task); 2642 if (mm) { 2643 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2644 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2645 MMF_DUMP_FILTER_SHIFT)); 2646 mmput(mm); 2647 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2648 } 2649 2650 put_task_struct(task); 2651 2652 return ret; 2653 } 2654 2655 static ssize_t proc_coredump_filter_write(struct file *file, 2656 const char __user *buf, 2657 size_t count, 2658 loff_t *ppos) 2659 { 2660 struct task_struct *task; 2661 struct mm_struct *mm; 2662 unsigned int val; 2663 int ret; 2664 int i; 2665 unsigned long mask; 2666 2667 ret = kstrtouint_from_user(buf, count, 0, &val); 2668 if (ret < 0) 2669 return ret; 2670 2671 ret = -ESRCH; 2672 task = get_proc_task(file_inode(file)); 2673 if (!task) 2674 goto out_no_task; 2675 2676 mm = get_task_mm(task); 2677 if (!mm) 2678 goto out_no_mm; 2679 ret = 0; 2680 2681 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2682 if (val & mask) 2683 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2684 else 2685 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2686 } 2687 2688 mmput(mm); 2689 out_no_mm: 2690 put_task_struct(task); 2691 out_no_task: 2692 if (ret < 0) 2693 return ret; 2694 return count; 2695 } 2696 2697 static const struct file_operations proc_coredump_filter_operations = { 2698 .read = proc_coredump_filter_read, 2699 .write = proc_coredump_filter_write, 2700 .llseek = generic_file_llseek, 2701 }; 2702 #endif 2703 2704 #ifdef CONFIG_TASK_IO_ACCOUNTING 2705 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole) 2706 { 2707 struct task_io_accounting acct = task->ioac; 2708 unsigned long flags; 2709 int result; 2710 2711 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2712 if (result) 2713 return result; 2714 2715 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { 2716 result = -EACCES; 2717 goto out_unlock; 2718 } 2719 2720 if (whole && lock_task_sighand(task, &flags)) { 2721 struct task_struct *t = task; 2722 2723 task_io_accounting_add(&acct, &task->signal->ioac); 2724 while_each_thread(task, t) 2725 task_io_accounting_add(&acct, &t->ioac); 2726 2727 unlock_task_sighand(task, &flags); 2728 } 2729 seq_printf(m, 2730 "rchar: %llu\n" 2731 "wchar: %llu\n" 2732 "syscr: %llu\n" 2733 "syscw: %llu\n" 2734 "read_bytes: %llu\n" 2735 "write_bytes: %llu\n" 2736 "cancelled_write_bytes: %llu\n", 2737 (unsigned long long)acct.rchar, 2738 (unsigned long long)acct.wchar, 2739 (unsigned long long)acct.syscr, 2740 (unsigned long long)acct.syscw, 2741 (unsigned long long)acct.read_bytes, 2742 (unsigned long long)acct.write_bytes, 2743 (unsigned long long)acct.cancelled_write_bytes); 2744 result = 0; 2745 2746 out_unlock: 2747 mutex_unlock(&task->signal->cred_guard_mutex); 2748 return result; 2749 } 2750 2751 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2752 struct pid *pid, struct task_struct *task) 2753 { 2754 return do_io_accounting(task, m, 0); 2755 } 2756 2757 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2758 struct pid *pid, struct task_struct *task) 2759 { 2760 return do_io_accounting(task, m, 1); 2761 } 2762 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2763 2764 #ifdef CONFIG_USER_NS 2765 static int proc_id_map_open(struct inode *inode, struct file *file, 2766 const struct seq_operations *seq_ops) 2767 { 2768 struct user_namespace *ns = NULL; 2769 struct task_struct *task; 2770 struct seq_file *seq; 2771 int ret = -EINVAL; 2772 2773 task = get_proc_task(inode); 2774 if (task) { 2775 rcu_read_lock(); 2776 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2777 rcu_read_unlock(); 2778 put_task_struct(task); 2779 } 2780 if (!ns) 2781 goto err; 2782 2783 ret = seq_open(file, seq_ops); 2784 if (ret) 2785 goto err_put_ns; 2786 2787 seq = file->private_data; 2788 seq->private = ns; 2789 2790 return 0; 2791 err_put_ns: 2792 put_user_ns(ns); 2793 err: 2794 return ret; 2795 } 2796 2797 static int proc_id_map_release(struct inode *inode, struct file *file) 2798 { 2799 struct seq_file *seq = file->private_data; 2800 struct user_namespace *ns = seq->private; 2801 put_user_ns(ns); 2802 return seq_release(inode, file); 2803 } 2804 2805 static int proc_uid_map_open(struct inode *inode, struct file *file) 2806 { 2807 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2808 } 2809 2810 static int proc_gid_map_open(struct inode *inode, struct file *file) 2811 { 2812 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2813 } 2814 2815 static int proc_projid_map_open(struct inode *inode, struct file *file) 2816 { 2817 return proc_id_map_open(inode, file, &proc_projid_seq_operations); 2818 } 2819 2820 static const struct file_operations proc_uid_map_operations = { 2821 .open = proc_uid_map_open, 2822 .write = proc_uid_map_write, 2823 .read = seq_read, 2824 .llseek = seq_lseek, 2825 .release = proc_id_map_release, 2826 }; 2827 2828 static const struct file_operations proc_gid_map_operations = { 2829 .open = proc_gid_map_open, 2830 .write = proc_gid_map_write, 2831 .read = seq_read, 2832 .llseek = seq_lseek, 2833 .release = proc_id_map_release, 2834 }; 2835 2836 static const struct file_operations proc_projid_map_operations = { 2837 .open = proc_projid_map_open, 2838 .write = proc_projid_map_write, 2839 .read = seq_read, 2840 .llseek = seq_lseek, 2841 .release = proc_id_map_release, 2842 }; 2843 2844 static int proc_setgroups_open(struct inode *inode, struct file *file) 2845 { 2846 struct user_namespace *ns = NULL; 2847 struct task_struct *task; 2848 int ret; 2849 2850 ret = -ESRCH; 2851 task = get_proc_task(inode); 2852 if (task) { 2853 rcu_read_lock(); 2854 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2855 rcu_read_unlock(); 2856 put_task_struct(task); 2857 } 2858 if (!ns) 2859 goto err; 2860 2861 if (file->f_mode & FMODE_WRITE) { 2862 ret = -EACCES; 2863 if (!ns_capable(ns, CAP_SYS_ADMIN)) 2864 goto err_put_ns; 2865 } 2866 2867 ret = single_open(file, &proc_setgroups_show, ns); 2868 if (ret) 2869 goto err_put_ns; 2870 2871 return 0; 2872 err_put_ns: 2873 put_user_ns(ns); 2874 err: 2875 return ret; 2876 } 2877 2878 static int proc_setgroups_release(struct inode *inode, struct file *file) 2879 { 2880 struct seq_file *seq = file->private_data; 2881 struct user_namespace *ns = seq->private; 2882 int ret = single_release(inode, file); 2883 put_user_ns(ns); 2884 return ret; 2885 } 2886 2887 static const struct file_operations proc_setgroups_operations = { 2888 .open = proc_setgroups_open, 2889 .write = proc_setgroups_write, 2890 .read = seq_read, 2891 .llseek = seq_lseek, 2892 .release = proc_setgroups_release, 2893 }; 2894 #endif /* CONFIG_USER_NS */ 2895 2896 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2897 struct pid *pid, struct task_struct *task) 2898 { 2899 int err = lock_trace(task); 2900 if (!err) { 2901 seq_printf(m, "%08x\n", task->personality); 2902 unlock_trace(task); 2903 } 2904 return err; 2905 } 2906 2907 #ifdef CONFIG_LIVEPATCH 2908 static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns, 2909 struct pid *pid, struct task_struct *task) 2910 { 2911 seq_printf(m, "%d\n", task->patch_state); 2912 return 0; 2913 } 2914 #endif /* CONFIG_LIVEPATCH */ 2915 2916 #ifdef CONFIG_STACKLEAK_METRICS 2917 static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns, 2918 struct pid *pid, struct task_struct *task) 2919 { 2920 unsigned long prev_depth = THREAD_SIZE - 2921 (task->prev_lowest_stack & (THREAD_SIZE - 1)); 2922 unsigned long depth = THREAD_SIZE - 2923 (task->lowest_stack & (THREAD_SIZE - 1)); 2924 2925 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n", 2926 prev_depth, depth); 2927 return 0; 2928 } 2929 #endif /* CONFIG_STACKLEAK_METRICS */ 2930 2931 /* 2932 * Thread groups 2933 */ 2934 static const struct file_operations proc_task_operations; 2935 static const struct inode_operations proc_task_inode_operations; 2936 2937 static const struct pid_entry tgid_base_stuff[] = { 2938 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2939 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2940 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 2941 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2942 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2943 #ifdef CONFIG_NET 2944 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2945 #endif 2946 REG("environ", S_IRUSR, proc_environ_operations), 2947 REG("auxv", S_IRUSR, proc_auxv_operations), 2948 ONE("status", S_IRUGO, proc_pid_status), 2949 ONE("personality", S_IRUSR, proc_pid_personality), 2950 ONE("limits", S_IRUGO, proc_pid_limits), 2951 #ifdef CONFIG_SCHED_DEBUG 2952 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2953 #endif 2954 #ifdef CONFIG_SCHED_AUTOGROUP 2955 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2956 #endif 2957 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2958 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2959 ONE("syscall", S_IRUSR, proc_pid_syscall), 2960 #endif 2961 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 2962 ONE("stat", S_IRUGO, proc_tgid_stat), 2963 ONE("statm", S_IRUGO, proc_pid_statm), 2964 REG("maps", S_IRUGO, proc_pid_maps_operations), 2965 #ifdef CONFIG_NUMA 2966 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 2967 #endif 2968 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2969 LNK("cwd", proc_cwd_link), 2970 LNK("root", proc_root_link), 2971 LNK("exe", proc_exe_link), 2972 REG("mounts", S_IRUGO, proc_mounts_operations), 2973 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2974 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2975 #ifdef CONFIG_PROC_PAGE_MONITOR 2976 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2977 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 2978 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations), 2979 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2980 #endif 2981 #ifdef CONFIG_SECURITY 2982 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2983 #endif 2984 #ifdef CONFIG_KALLSYMS 2985 ONE("wchan", S_IRUGO, proc_pid_wchan), 2986 #endif 2987 #ifdef CONFIG_STACKTRACE 2988 ONE("stack", S_IRUSR, proc_pid_stack), 2989 #endif 2990 #ifdef CONFIG_SCHED_INFO 2991 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 2992 #endif 2993 #ifdef CONFIG_LATENCYTOP 2994 REG("latency", S_IRUGO, proc_lstats_operations), 2995 #endif 2996 #ifdef CONFIG_PROC_PID_CPUSET 2997 ONE("cpuset", S_IRUGO, proc_cpuset_show), 2998 #endif 2999 #ifdef CONFIG_CGROUPS 3000 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3001 #endif 3002 ONE("oom_score", S_IRUGO, proc_oom_score), 3003 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3004 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3005 #ifdef CONFIG_AUDITSYSCALL 3006 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3007 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3008 #endif 3009 #ifdef CONFIG_FAULT_INJECTION 3010 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3011 REG("fail-nth", 0644, proc_fail_nth_operations), 3012 #endif 3013 #ifdef CONFIG_ELF_CORE 3014 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 3015 #endif 3016 #ifdef CONFIG_TASK_IO_ACCOUNTING 3017 ONE("io", S_IRUSR, proc_tgid_io_accounting), 3018 #endif 3019 #ifdef CONFIG_USER_NS 3020 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3021 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3022 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3023 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3024 #endif 3025 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS) 3026 REG("timers", S_IRUGO, proc_timers_operations), 3027 #endif 3028 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations), 3029 #ifdef CONFIG_LIVEPATCH 3030 ONE("patch_state", S_IRUSR, proc_pid_patch_state), 3031 #endif 3032 #ifdef CONFIG_STACKLEAK_METRICS 3033 ONE("stack_depth", S_IRUGO, proc_stack_depth), 3034 #endif 3035 }; 3036 3037 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) 3038 { 3039 return proc_pident_readdir(file, ctx, 3040 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3041 } 3042 3043 static const struct file_operations proc_tgid_base_operations = { 3044 .read = generic_read_dir, 3045 .iterate_shared = proc_tgid_base_readdir, 3046 .llseek = generic_file_llseek, 3047 }; 3048 3049 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3050 { 3051 return proc_pident_lookup(dir, dentry, 3052 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3053 } 3054 3055 static const struct inode_operations proc_tgid_base_inode_operations = { 3056 .lookup = proc_tgid_base_lookup, 3057 .getattr = pid_getattr, 3058 .setattr = proc_setattr, 3059 .permission = proc_pid_permission, 3060 }; 3061 3062 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 3063 { 3064 struct dentry *dentry, *leader, *dir; 3065 char buf[10 + 1]; 3066 struct qstr name; 3067 3068 name.name = buf; 3069 name.len = snprintf(buf, sizeof(buf), "%u", pid); 3070 /* no ->d_hash() rejects on procfs */ 3071 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 3072 if (dentry) { 3073 d_invalidate(dentry); 3074 dput(dentry); 3075 } 3076 3077 if (pid == tgid) 3078 return; 3079 3080 name.name = buf; 3081 name.len = snprintf(buf, sizeof(buf), "%u", tgid); 3082 leader = d_hash_and_lookup(mnt->mnt_root, &name); 3083 if (!leader) 3084 goto out; 3085 3086 name.name = "task"; 3087 name.len = strlen(name.name); 3088 dir = d_hash_and_lookup(leader, &name); 3089 if (!dir) 3090 goto out_put_leader; 3091 3092 name.name = buf; 3093 name.len = snprintf(buf, sizeof(buf), "%u", pid); 3094 dentry = d_hash_and_lookup(dir, &name); 3095 if (dentry) { 3096 d_invalidate(dentry); 3097 dput(dentry); 3098 } 3099 3100 dput(dir); 3101 out_put_leader: 3102 dput(leader); 3103 out: 3104 return; 3105 } 3106 3107 /** 3108 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 3109 * @task: task that should be flushed. 3110 * 3111 * When flushing dentries from proc, one needs to flush them from global 3112 * proc (proc_mnt) and from all the namespaces' procs this task was seen 3113 * in. This call is supposed to do all of this job. 3114 * 3115 * Looks in the dcache for 3116 * /proc/@pid 3117 * /proc/@tgid/task/@pid 3118 * if either directory is present flushes it and all of it'ts children 3119 * from the dcache. 3120 * 3121 * It is safe and reasonable to cache /proc entries for a task until 3122 * that task exits. After that they just clog up the dcache with 3123 * useless entries, possibly causing useful dcache entries to be 3124 * flushed instead. This routine is proved to flush those useless 3125 * dcache entries at process exit time. 3126 * 3127 * NOTE: This routine is just an optimization so it does not guarantee 3128 * that no dcache entries will exist at process exit time it 3129 * just makes it very unlikely that any will persist. 3130 */ 3131 3132 void proc_flush_task(struct task_struct *task) 3133 { 3134 int i; 3135 struct pid *pid, *tgid; 3136 struct upid *upid; 3137 3138 pid = task_pid(task); 3139 tgid = task_tgid(task); 3140 3141 for (i = 0; i <= pid->level; i++) { 3142 upid = &pid->numbers[i]; 3143 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3144 tgid->numbers[i].nr); 3145 } 3146 } 3147 3148 static struct dentry *proc_pid_instantiate(struct dentry * dentry, 3149 struct task_struct *task, const void *ptr) 3150 { 3151 struct inode *inode; 3152 3153 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3154 if (!inode) 3155 return ERR_PTR(-ENOENT); 3156 3157 inode->i_op = &proc_tgid_base_inode_operations; 3158 inode->i_fop = &proc_tgid_base_operations; 3159 inode->i_flags|=S_IMMUTABLE; 3160 3161 set_nlink(inode, nlink_tgid); 3162 pid_update_inode(task, inode); 3163 3164 d_set_d_op(dentry, &pid_dentry_operations); 3165 return d_splice_alias(inode, dentry); 3166 } 3167 3168 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3169 { 3170 struct task_struct *task; 3171 unsigned tgid; 3172 struct pid_namespace *ns; 3173 struct dentry *result = ERR_PTR(-ENOENT); 3174 3175 tgid = name_to_int(&dentry->d_name); 3176 if (tgid == ~0U) 3177 goto out; 3178 3179 ns = dentry->d_sb->s_fs_info; 3180 rcu_read_lock(); 3181 task = find_task_by_pid_ns(tgid, ns); 3182 if (task) 3183 get_task_struct(task); 3184 rcu_read_unlock(); 3185 if (!task) 3186 goto out; 3187 3188 result = proc_pid_instantiate(dentry, task, NULL); 3189 put_task_struct(task); 3190 out: 3191 return result; 3192 } 3193 3194 /* 3195 * Find the first task with tgid >= tgid 3196 * 3197 */ 3198 struct tgid_iter { 3199 unsigned int tgid; 3200 struct task_struct *task; 3201 }; 3202 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3203 { 3204 struct pid *pid; 3205 3206 if (iter.task) 3207 put_task_struct(iter.task); 3208 rcu_read_lock(); 3209 retry: 3210 iter.task = NULL; 3211 pid = find_ge_pid(iter.tgid, ns); 3212 if (pid) { 3213 iter.tgid = pid_nr_ns(pid, ns); 3214 iter.task = pid_task(pid, PIDTYPE_PID); 3215 /* What we to know is if the pid we have find is the 3216 * pid of a thread_group_leader. Testing for task 3217 * being a thread_group_leader is the obvious thing 3218 * todo but there is a window when it fails, due to 3219 * the pid transfer logic in de_thread. 3220 * 3221 * So we perform the straight forward test of seeing 3222 * if the pid we have found is the pid of a thread 3223 * group leader, and don't worry if the task we have 3224 * found doesn't happen to be a thread group leader. 3225 * As we don't care in the case of readdir. 3226 */ 3227 if (!iter.task || !has_group_leader_pid(iter.task)) { 3228 iter.tgid += 1; 3229 goto retry; 3230 } 3231 get_task_struct(iter.task); 3232 } 3233 rcu_read_unlock(); 3234 return iter; 3235 } 3236 3237 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2) 3238 3239 /* for the /proc/ directory itself, after non-process stuff has been done */ 3240 int proc_pid_readdir(struct file *file, struct dir_context *ctx) 3241 { 3242 struct tgid_iter iter; 3243 struct pid_namespace *ns = proc_pid_ns(file_inode(file)); 3244 loff_t pos = ctx->pos; 3245 3246 if (pos >= PID_MAX_LIMIT + TGID_OFFSET) 3247 return 0; 3248 3249 if (pos == TGID_OFFSET - 2) { 3250 struct inode *inode = d_inode(ns->proc_self); 3251 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) 3252 return 0; 3253 ctx->pos = pos = pos + 1; 3254 } 3255 if (pos == TGID_OFFSET - 1) { 3256 struct inode *inode = d_inode(ns->proc_thread_self); 3257 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) 3258 return 0; 3259 ctx->pos = pos = pos + 1; 3260 } 3261 iter.tgid = pos - TGID_OFFSET; 3262 iter.task = NULL; 3263 for (iter = next_tgid(ns, iter); 3264 iter.task; 3265 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3266 char name[10 + 1]; 3267 unsigned int len; 3268 3269 cond_resched(); 3270 if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE)) 3271 continue; 3272 3273 len = snprintf(name, sizeof(name), "%u", iter.tgid); 3274 ctx->pos = iter.tgid + TGID_OFFSET; 3275 if (!proc_fill_cache(file, ctx, name, len, 3276 proc_pid_instantiate, iter.task, NULL)) { 3277 put_task_struct(iter.task); 3278 return 0; 3279 } 3280 } 3281 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET; 3282 return 0; 3283 } 3284 3285 /* 3286 * proc_tid_comm_permission is a special permission function exclusively 3287 * used for the node /proc/<pid>/task/<tid>/comm. 3288 * It bypasses generic permission checks in the case where a task of the same 3289 * task group attempts to access the node. 3290 * The rationale behind this is that glibc and bionic access this node for 3291 * cross thread naming (pthread_set/getname_np(!self)). However, if 3292 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0, 3293 * which locks out the cross thread naming implementation. 3294 * This function makes sure that the node is always accessible for members of 3295 * same thread group. 3296 */ 3297 static int proc_tid_comm_permission(struct inode *inode, int mask) 3298 { 3299 bool is_same_tgroup; 3300 struct task_struct *task; 3301 3302 task = get_proc_task(inode); 3303 if (!task) 3304 return -ESRCH; 3305 is_same_tgroup = same_thread_group(current, task); 3306 put_task_struct(task); 3307 3308 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) { 3309 /* This file (/proc/<pid>/task/<tid>/comm) can always be 3310 * read or written by the members of the corresponding 3311 * thread group. 3312 */ 3313 return 0; 3314 } 3315 3316 return generic_permission(inode, mask); 3317 } 3318 3319 static const struct inode_operations proc_tid_comm_inode_operations = { 3320 .permission = proc_tid_comm_permission, 3321 }; 3322 3323 /* 3324 * Tasks 3325 */ 3326 static const struct pid_entry tid_base_stuff[] = { 3327 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3328 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3329 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3330 #ifdef CONFIG_NET 3331 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3332 #endif 3333 REG("environ", S_IRUSR, proc_environ_operations), 3334 REG("auxv", S_IRUSR, proc_auxv_operations), 3335 ONE("status", S_IRUGO, proc_pid_status), 3336 ONE("personality", S_IRUSR, proc_pid_personality), 3337 ONE("limits", S_IRUGO, proc_pid_limits), 3338 #ifdef CONFIG_SCHED_DEBUG 3339 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3340 #endif 3341 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR, 3342 &proc_tid_comm_inode_operations, 3343 &proc_pid_set_comm_operations, {}), 3344 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3345 ONE("syscall", S_IRUSR, proc_pid_syscall), 3346 #endif 3347 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 3348 ONE("stat", S_IRUGO, proc_tid_stat), 3349 ONE("statm", S_IRUGO, proc_pid_statm), 3350 REG("maps", S_IRUGO, proc_pid_maps_operations), 3351 #ifdef CONFIG_PROC_CHILDREN 3352 REG("children", S_IRUGO, proc_tid_children_operations), 3353 #endif 3354 #ifdef CONFIG_NUMA 3355 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 3356 #endif 3357 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3358 LNK("cwd", proc_cwd_link), 3359 LNK("root", proc_root_link), 3360 LNK("exe", proc_exe_link), 3361 REG("mounts", S_IRUGO, proc_mounts_operations), 3362 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3363 #ifdef CONFIG_PROC_PAGE_MONITOR 3364 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3365 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 3366 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations), 3367 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3368 #endif 3369 #ifdef CONFIG_SECURITY 3370 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3371 #endif 3372 #ifdef CONFIG_KALLSYMS 3373 ONE("wchan", S_IRUGO, proc_pid_wchan), 3374 #endif 3375 #ifdef CONFIG_STACKTRACE 3376 ONE("stack", S_IRUSR, proc_pid_stack), 3377 #endif 3378 #ifdef CONFIG_SCHED_INFO 3379 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 3380 #endif 3381 #ifdef CONFIG_LATENCYTOP 3382 REG("latency", S_IRUGO, proc_lstats_operations), 3383 #endif 3384 #ifdef CONFIG_PROC_PID_CPUSET 3385 ONE("cpuset", S_IRUGO, proc_cpuset_show), 3386 #endif 3387 #ifdef CONFIG_CGROUPS 3388 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3389 #endif 3390 ONE("oom_score", S_IRUGO, proc_oom_score), 3391 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3392 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3393 #ifdef CONFIG_AUDITSYSCALL 3394 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3395 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3396 #endif 3397 #ifdef CONFIG_FAULT_INJECTION 3398 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3399 REG("fail-nth", 0644, proc_fail_nth_operations), 3400 #endif 3401 #ifdef CONFIG_TASK_IO_ACCOUNTING 3402 ONE("io", S_IRUSR, proc_tid_io_accounting), 3403 #endif 3404 #ifdef CONFIG_USER_NS 3405 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3406 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3407 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3408 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3409 #endif 3410 #ifdef CONFIG_LIVEPATCH 3411 ONE("patch_state", S_IRUSR, proc_pid_patch_state), 3412 #endif 3413 }; 3414 3415 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx) 3416 { 3417 return proc_pident_readdir(file, ctx, 3418 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3419 } 3420 3421 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3422 { 3423 return proc_pident_lookup(dir, dentry, 3424 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3425 } 3426 3427 static const struct file_operations proc_tid_base_operations = { 3428 .read = generic_read_dir, 3429 .iterate_shared = proc_tid_base_readdir, 3430 .llseek = generic_file_llseek, 3431 }; 3432 3433 static const struct inode_operations proc_tid_base_inode_operations = { 3434 .lookup = proc_tid_base_lookup, 3435 .getattr = pid_getattr, 3436 .setattr = proc_setattr, 3437 }; 3438 3439 static struct dentry *proc_task_instantiate(struct dentry *dentry, 3440 struct task_struct *task, const void *ptr) 3441 { 3442 struct inode *inode; 3443 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3444 if (!inode) 3445 return ERR_PTR(-ENOENT); 3446 3447 inode->i_op = &proc_tid_base_inode_operations; 3448 inode->i_fop = &proc_tid_base_operations; 3449 inode->i_flags |= S_IMMUTABLE; 3450 3451 set_nlink(inode, nlink_tid); 3452 pid_update_inode(task, inode); 3453 3454 d_set_d_op(dentry, &pid_dentry_operations); 3455 return d_splice_alias(inode, dentry); 3456 } 3457 3458 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3459 { 3460 struct task_struct *task; 3461 struct task_struct *leader = get_proc_task(dir); 3462 unsigned tid; 3463 struct pid_namespace *ns; 3464 struct dentry *result = ERR_PTR(-ENOENT); 3465 3466 if (!leader) 3467 goto out_no_task; 3468 3469 tid = name_to_int(&dentry->d_name); 3470 if (tid == ~0U) 3471 goto out; 3472 3473 ns = dentry->d_sb->s_fs_info; 3474 rcu_read_lock(); 3475 task = find_task_by_pid_ns(tid, ns); 3476 if (task) 3477 get_task_struct(task); 3478 rcu_read_unlock(); 3479 if (!task) 3480 goto out; 3481 if (!same_thread_group(leader, task)) 3482 goto out_drop_task; 3483 3484 result = proc_task_instantiate(dentry, task, NULL); 3485 out_drop_task: 3486 put_task_struct(task); 3487 out: 3488 put_task_struct(leader); 3489 out_no_task: 3490 return result; 3491 } 3492 3493 /* 3494 * Find the first tid of a thread group to return to user space. 3495 * 3496 * Usually this is just the thread group leader, but if the users 3497 * buffer was too small or there was a seek into the middle of the 3498 * directory we have more work todo. 3499 * 3500 * In the case of a short read we start with find_task_by_pid. 3501 * 3502 * In the case of a seek we start with the leader and walk nr 3503 * threads past it. 3504 */ 3505 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos, 3506 struct pid_namespace *ns) 3507 { 3508 struct task_struct *pos, *task; 3509 unsigned long nr = f_pos; 3510 3511 if (nr != f_pos) /* 32bit overflow? */ 3512 return NULL; 3513 3514 rcu_read_lock(); 3515 task = pid_task(pid, PIDTYPE_PID); 3516 if (!task) 3517 goto fail; 3518 3519 /* Attempt to start with the tid of a thread */ 3520 if (tid && nr) { 3521 pos = find_task_by_pid_ns(tid, ns); 3522 if (pos && same_thread_group(pos, task)) 3523 goto found; 3524 } 3525 3526 /* If nr exceeds the number of threads there is nothing todo */ 3527 if (nr >= get_nr_threads(task)) 3528 goto fail; 3529 3530 /* If we haven't found our starting place yet start 3531 * with the leader and walk nr threads forward. 3532 */ 3533 pos = task = task->group_leader; 3534 do { 3535 if (!nr--) 3536 goto found; 3537 } while_each_thread(task, pos); 3538 fail: 3539 pos = NULL; 3540 goto out; 3541 found: 3542 get_task_struct(pos); 3543 out: 3544 rcu_read_unlock(); 3545 return pos; 3546 } 3547 3548 /* 3549 * Find the next thread in the thread list. 3550 * Return NULL if there is an error or no next thread. 3551 * 3552 * The reference to the input task_struct is released. 3553 */ 3554 static struct task_struct *next_tid(struct task_struct *start) 3555 { 3556 struct task_struct *pos = NULL; 3557 rcu_read_lock(); 3558 if (pid_alive(start)) { 3559 pos = next_thread(start); 3560 if (thread_group_leader(pos)) 3561 pos = NULL; 3562 else 3563 get_task_struct(pos); 3564 } 3565 rcu_read_unlock(); 3566 put_task_struct(start); 3567 return pos; 3568 } 3569 3570 /* for the /proc/TGID/task/ directories */ 3571 static int proc_task_readdir(struct file *file, struct dir_context *ctx) 3572 { 3573 struct inode *inode = file_inode(file); 3574 struct task_struct *task; 3575 struct pid_namespace *ns; 3576 int tid; 3577 3578 if (proc_inode_is_dead(inode)) 3579 return -ENOENT; 3580 3581 if (!dir_emit_dots(file, ctx)) 3582 return 0; 3583 3584 /* f_version caches the tgid value that the last readdir call couldn't 3585 * return. lseek aka telldir automagically resets f_version to 0. 3586 */ 3587 ns = proc_pid_ns(inode); 3588 tid = (int)file->f_version; 3589 file->f_version = 0; 3590 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); 3591 task; 3592 task = next_tid(task), ctx->pos++) { 3593 char name[10 + 1]; 3594 unsigned int len; 3595 tid = task_pid_nr_ns(task, ns); 3596 len = snprintf(name, sizeof(name), "%u", tid); 3597 if (!proc_fill_cache(file, ctx, name, len, 3598 proc_task_instantiate, task, NULL)) { 3599 /* returning this tgid failed, save it as the first 3600 * pid for the next readir call */ 3601 file->f_version = (u64)tid; 3602 put_task_struct(task); 3603 break; 3604 } 3605 } 3606 3607 return 0; 3608 } 3609 3610 static int proc_task_getattr(const struct path *path, struct kstat *stat, 3611 u32 request_mask, unsigned int query_flags) 3612 { 3613 struct inode *inode = d_inode(path->dentry); 3614 struct task_struct *p = get_proc_task(inode); 3615 generic_fillattr(inode, stat); 3616 3617 if (p) { 3618 stat->nlink += get_nr_threads(p); 3619 put_task_struct(p); 3620 } 3621 3622 return 0; 3623 } 3624 3625 static const struct inode_operations proc_task_inode_operations = { 3626 .lookup = proc_task_lookup, 3627 .getattr = proc_task_getattr, 3628 .setattr = proc_setattr, 3629 .permission = proc_pid_permission, 3630 }; 3631 3632 static const struct file_operations proc_task_operations = { 3633 .read = generic_read_dir, 3634 .iterate_shared = proc_task_readdir, 3635 .llseek = generic_file_llseek, 3636 }; 3637 3638 void __init set_proc_pid_nlink(void) 3639 { 3640 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3641 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3642 } 3643