1 /* 2 * linux/fs/proc/base.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 * 6 * proc base directory handling functions 7 * 8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part. 9 * Instead of using magical inumbers to determine the kind of object 10 * we allocate and fill in-core inodes upon lookup. They don't even 11 * go into icache. We cache the reference to task_struct upon lookup too. 12 * Eventually it should become a filesystem in its own. We don't use the 13 * rest of procfs anymore. 14 * 15 * 16 * Changelog: 17 * 17-Jan-2005 18 * Allan Bezerra 19 * Bruna Moreira <bruna.moreira@indt.org.br> 20 * Edjard Mota <edjard.mota@indt.org.br> 21 * Ilias Biris <ilias.biris@indt.org.br> 22 * Mauricio Lin <mauricio.lin@indt.org.br> 23 * 24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 25 * 26 * A new process specific entry (smaps) included in /proc. It shows the 27 * size of rss for each memory area. The maps entry lacks information 28 * about physical memory size (rss) for each mapped file, i.e., 29 * rss information for executables and library files. 30 * This additional information is useful for any tools that need to know 31 * about physical memory consumption for a process specific library. 32 * 33 * Changelog: 34 * 21-Feb-2005 35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 36 * Pud inclusion in the page table walking. 37 * 38 * ChangeLog: 39 * 10-Mar-2005 40 * 10LE Instituto Nokia de Tecnologia - INdT: 41 * A better way to walks through the page table as suggested by Hugh Dickins. 42 * 43 * Simo Piiroinen <simo.piiroinen@nokia.com>: 44 * Smaps information related to shared, private, clean and dirty pages. 45 * 46 * Paul Mundt <paul.mundt@nokia.com>: 47 * Overall revision about smaps. 48 */ 49 50 #include <asm/uaccess.h> 51 52 #include <linux/errno.h> 53 #include <linux/time.h> 54 #include <linux/proc_fs.h> 55 #include <linux/stat.h> 56 #include <linux/task_io_accounting_ops.h> 57 #include <linux/init.h> 58 #include <linux/capability.h> 59 #include <linux/file.h> 60 #include <linux/fdtable.h> 61 #include <linux/string.h> 62 #include <linux/seq_file.h> 63 #include <linux/namei.h> 64 #include <linux/mnt_namespace.h> 65 #include <linux/mm.h> 66 #include <linux/swap.h> 67 #include <linux/rcupdate.h> 68 #include <linux/kallsyms.h> 69 #include <linux/stacktrace.h> 70 #include <linux/resource.h> 71 #include <linux/module.h> 72 #include <linux/mount.h> 73 #include <linux/security.h> 74 #include <linux/ptrace.h> 75 #include <linux/tracehook.h> 76 #include <linux/printk.h> 77 #include <linux/cgroup.h> 78 #include <linux/cpuset.h> 79 #include <linux/audit.h> 80 #include <linux/poll.h> 81 #include <linux/nsproxy.h> 82 #include <linux/oom.h> 83 #include <linux/elf.h> 84 #include <linux/pid_namespace.h> 85 #include <linux/user_namespace.h> 86 #include <linux/fs_struct.h> 87 #include <linux/slab.h> 88 #include <linux/flex_array.h> 89 #include <linux/posix-timers.h> 90 #ifdef CONFIG_HARDWALL 91 #include <asm/hardwall.h> 92 #endif 93 #include <trace/events/oom.h> 94 #include "internal.h" 95 #include "fd.h" 96 97 /* NOTE: 98 * Implementing inode permission operations in /proc is almost 99 * certainly an error. Permission checks need to happen during 100 * each system call not at open time. The reason is that most of 101 * what we wish to check for permissions in /proc varies at runtime. 102 * 103 * The classic example of a problem is opening file descriptors 104 * in /proc for a task before it execs a suid executable. 105 */ 106 107 struct pid_entry { 108 const char *name; 109 int len; 110 umode_t mode; 111 const struct inode_operations *iop; 112 const struct file_operations *fop; 113 union proc_op op; 114 }; 115 116 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 117 .name = (NAME), \ 118 .len = sizeof(NAME) - 1, \ 119 .mode = MODE, \ 120 .iop = IOP, \ 121 .fop = FOP, \ 122 .op = OP, \ 123 } 124 125 #define DIR(NAME, MODE, iops, fops) \ 126 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} ) 127 #define LNK(NAME, get_link) \ 128 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 129 &proc_pid_link_inode_operations, NULL, \ 130 { .proc_get_link = get_link } ) 131 #define REG(NAME, MODE, fops) \ 132 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {}) 133 #define ONE(NAME, MODE, show) \ 134 NOD(NAME, (S_IFREG|(MODE)), \ 135 NULL, &proc_single_file_operations, \ 136 { .proc_show = show } ) 137 138 /* 139 * Count the number of hardlinks for the pid_entry table, excluding the . 140 * and .. links. 141 */ 142 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries, 143 unsigned int n) 144 { 145 unsigned int i; 146 unsigned int count; 147 148 count = 0; 149 for (i = 0; i < n; ++i) { 150 if (S_ISDIR(entries[i].mode)) 151 ++count; 152 } 153 154 return count; 155 } 156 157 static int get_task_root(struct task_struct *task, struct path *root) 158 { 159 int result = -ENOENT; 160 161 task_lock(task); 162 if (task->fs) { 163 get_fs_root(task->fs, root); 164 result = 0; 165 } 166 task_unlock(task); 167 return result; 168 } 169 170 static int proc_cwd_link(struct dentry *dentry, struct path *path) 171 { 172 struct task_struct *task = get_proc_task(d_inode(dentry)); 173 int result = -ENOENT; 174 175 if (task) { 176 task_lock(task); 177 if (task->fs) { 178 get_fs_pwd(task->fs, path); 179 result = 0; 180 } 181 task_unlock(task); 182 put_task_struct(task); 183 } 184 return result; 185 } 186 187 static int proc_root_link(struct dentry *dentry, struct path *path) 188 { 189 struct task_struct *task = get_proc_task(d_inode(dentry)); 190 int result = -ENOENT; 191 192 if (task) { 193 result = get_task_root(task, path); 194 put_task_struct(task); 195 } 196 return result; 197 } 198 199 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, 200 size_t _count, loff_t *pos) 201 { 202 struct task_struct *tsk; 203 struct mm_struct *mm; 204 char *page; 205 unsigned long count = _count; 206 unsigned long arg_start, arg_end, env_start, env_end; 207 unsigned long len1, len2, len; 208 unsigned long p; 209 char c; 210 ssize_t rv; 211 212 BUG_ON(*pos < 0); 213 214 tsk = get_proc_task(file_inode(file)); 215 if (!tsk) 216 return -ESRCH; 217 mm = get_task_mm(tsk); 218 put_task_struct(tsk); 219 if (!mm) 220 return 0; 221 /* Check if process spawned far enough to have cmdline. */ 222 if (!mm->env_end) { 223 rv = 0; 224 goto out_mmput; 225 } 226 227 page = (char *)__get_free_page(GFP_TEMPORARY); 228 if (!page) { 229 rv = -ENOMEM; 230 goto out_mmput; 231 } 232 233 down_read(&mm->mmap_sem); 234 arg_start = mm->arg_start; 235 arg_end = mm->arg_end; 236 env_start = mm->env_start; 237 env_end = mm->env_end; 238 up_read(&mm->mmap_sem); 239 240 BUG_ON(arg_start > arg_end); 241 BUG_ON(env_start > env_end); 242 243 len1 = arg_end - arg_start; 244 len2 = env_end - env_start; 245 246 /* Empty ARGV. */ 247 if (len1 == 0) { 248 rv = 0; 249 goto out_free_page; 250 } 251 /* 252 * Inherently racy -- command line shares address space 253 * with code and data. 254 */ 255 rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0); 256 if (rv <= 0) 257 goto out_free_page; 258 259 rv = 0; 260 261 if (c == '\0') { 262 /* Command line (set of strings) occupies whole ARGV. */ 263 if (len1 <= *pos) 264 goto out_free_page; 265 266 p = arg_start + *pos; 267 len = len1 - *pos; 268 while (count > 0 && len > 0) { 269 unsigned int _count; 270 int nr_read; 271 272 _count = min3(count, len, PAGE_SIZE); 273 nr_read = access_remote_vm(mm, p, page, _count, 0); 274 if (nr_read < 0) 275 rv = nr_read; 276 if (nr_read <= 0) 277 goto out_free_page; 278 279 if (copy_to_user(buf, page, nr_read)) { 280 rv = -EFAULT; 281 goto out_free_page; 282 } 283 284 p += nr_read; 285 len -= nr_read; 286 buf += nr_read; 287 count -= nr_read; 288 rv += nr_read; 289 } 290 } else { 291 /* 292 * Command line (1 string) occupies ARGV and maybe 293 * extends into ENVP. 294 */ 295 if (len1 + len2 <= *pos) 296 goto skip_argv_envp; 297 if (len1 <= *pos) 298 goto skip_argv; 299 300 p = arg_start + *pos; 301 len = len1 - *pos; 302 while (count > 0 && len > 0) { 303 unsigned int _count, l; 304 int nr_read; 305 bool final; 306 307 _count = min3(count, len, PAGE_SIZE); 308 nr_read = access_remote_vm(mm, p, page, _count, 0); 309 if (nr_read < 0) 310 rv = nr_read; 311 if (nr_read <= 0) 312 goto out_free_page; 313 314 /* 315 * Command line can be shorter than whole ARGV 316 * even if last "marker" byte says it is not. 317 */ 318 final = false; 319 l = strnlen(page, nr_read); 320 if (l < nr_read) { 321 nr_read = l; 322 final = true; 323 } 324 325 if (copy_to_user(buf, page, nr_read)) { 326 rv = -EFAULT; 327 goto out_free_page; 328 } 329 330 p += nr_read; 331 len -= nr_read; 332 buf += nr_read; 333 count -= nr_read; 334 rv += nr_read; 335 336 if (final) 337 goto out_free_page; 338 } 339 skip_argv: 340 /* 341 * Command line (1 string) occupies ARGV and 342 * extends into ENVP. 343 */ 344 if (len1 <= *pos) { 345 p = env_start + *pos - len1; 346 len = len1 + len2 - *pos; 347 } else { 348 p = env_start; 349 len = len2; 350 } 351 while (count > 0 && len > 0) { 352 unsigned int _count, l; 353 int nr_read; 354 bool final; 355 356 _count = min3(count, len, PAGE_SIZE); 357 nr_read = access_remote_vm(mm, p, page, _count, 0); 358 if (nr_read < 0) 359 rv = nr_read; 360 if (nr_read <= 0) 361 goto out_free_page; 362 363 /* Find EOS. */ 364 final = false; 365 l = strnlen(page, nr_read); 366 if (l < nr_read) { 367 nr_read = l; 368 final = true; 369 } 370 371 if (copy_to_user(buf, page, nr_read)) { 372 rv = -EFAULT; 373 goto out_free_page; 374 } 375 376 p += nr_read; 377 len -= nr_read; 378 buf += nr_read; 379 count -= nr_read; 380 rv += nr_read; 381 382 if (final) 383 goto out_free_page; 384 } 385 skip_argv_envp: 386 ; 387 } 388 389 out_free_page: 390 free_page((unsigned long)page); 391 out_mmput: 392 mmput(mm); 393 if (rv > 0) 394 *pos += rv; 395 return rv; 396 } 397 398 static const struct file_operations proc_pid_cmdline_ops = { 399 .read = proc_pid_cmdline_read, 400 .llseek = generic_file_llseek, 401 }; 402 403 static int proc_pid_auxv(struct seq_file *m, struct pid_namespace *ns, 404 struct pid *pid, struct task_struct *task) 405 { 406 struct mm_struct *mm = mm_access(task, PTRACE_MODE_READ); 407 if (mm && !IS_ERR(mm)) { 408 unsigned int nwords = 0; 409 do { 410 nwords += 2; 411 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 412 seq_write(m, mm->saved_auxv, nwords * sizeof(mm->saved_auxv[0])); 413 mmput(mm); 414 return 0; 415 } else 416 return PTR_ERR(mm); 417 } 418 419 420 #ifdef CONFIG_KALLSYMS 421 /* 422 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 423 * Returns the resolved symbol. If that fails, simply return the address. 424 */ 425 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns, 426 struct pid *pid, struct task_struct *task) 427 { 428 unsigned long wchan; 429 char symname[KSYM_NAME_LEN]; 430 431 wchan = get_wchan(task); 432 433 if (wchan && ptrace_may_access(task, PTRACE_MODE_READ) && !lookup_symbol_name(wchan, symname)) 434 seq_printf(m, "%s", symname); 435 else 436 seq_putc(m, '0'); 437 438 return 0; 439 } 440 #endif /* CONFIG_KALLSYMS */ 441 442 static int lock_trace(struct task_struct *task) 443 { 444 int err = mutex_lock_killable(&task->signal->cred_guard_mutex); 445 if (err) 446 return err; 447 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) { 448 mutex_unlock(&task->signal->cred_guard_mutex); 449 return -EPERM; 450 } 451 return 0; 452 } 453 454 static void unlock_trace(struct task_struct *task) 455 { 456 mutex_unlock(&task->signal->cred_guard_mutex); 457 } 458 459 #ifdef CONFIG_STACKTRACE 460 461 #define MAX_STACK_TRACE_DEPTH 64 462 463 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, 464 struct pid *pid, struct task_struct *task) 465 { 466 struct stack_trace trace; 467 unsigned long *entries; 468 int err; 469 int i; 470 471 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL); 472 if (!entries) 473 return -ENOMEM; 474 475 trace.nr_entries = 0; 476 trace.max_entries = MAX_STACK_TRACE_DEPTH; 477 trace.entries = entries; 478 trace.skip = 0; 479 480 err = lock_trace(task); 481 if (!err) { 482 save_stack_trace_tsk(task, &trace); 483 484 for (i = 0; i < trace.nr_entries; i++) { 485 seq_printf(m, "[<%pK>] %pS\n", 486 (void *)entries[i], (void *)entries[i]); 487 } 488 unlock_trace(task); 489 } 490 kfree(entries); 491 492 return err; 493 } 494 #endif 495 496 #ifdef CONFIG_SCHED_INFO 497 /* 498 * Provides /proc/PID/schedstat 499 */ 500 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, 501 struct pid *pid, struct task_struct *task) 502 { 503 if (unlikely(!sched_info_on())) 504 seq_printf(m, "0 0 0\n"); 505 else 506 seq_printf(m, "%llu %llu %lu\n", 507 (unsigned long long)task->se.sum_exec_runtime, 508 (unsigned long long)task->sched_info.run_delay, 509 task->sched_info.pcount); 510 511 return 0; 512 } 513 #endif 514 515 #ifdef CONFIG_LATENCYTOP 516 static int lstats_show_proc(struct seq_file *m, void *v) 517 { 518 int i; 519 struct inode *inode = m->private; 520 struct task_struct *task = get_proc_task(inode); 521 522 if (!task) 523 return -ESRCH; 524 seq_puts(m, "Latency Top version : v0.1\n"); 525 for (i = 0; i < 32; i++) { 526 struct latency_record *lr = &task->latency_record[i]; 527 if (lr->backtrace[0]) { 528 int q; 529 seq_printf(m, "%i %li %li", 530 lr->count, lr->time, lr->max); 531 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 532 unsigned long bt = lr->backtrace[q]; 533 if (!bt) 534 break; 535 if (bt == ULONG_MAX) 536 break; 537 seq_printf(m, " %ps", (void *)bt); 538 } 539 seq_putc(m, '\n'); 540 } 541 542 } 543 put_task_struct(task); 544 return 0; 545 } 546 547 static int lstats_open(struct inode *inode, struct file *file) 548 { 549 return single_open(file, lstats_show_proc, inode); 550 } 551 552 static ssize_t lstats_write(struct file *file, const char __user *buf, 553 size_t count, loff_t *offs) 554 { 555 struct task_struct *task = get_proc_task(file_inode(file)); 556 557 if (!task) 558 return -ESRCH; 559 clear_all_latency_tracing(task); 560 put_task_struct(task); 561 562 return count; 563 } 564 565 static const struct file_operations proc_lstats_operations = { 566 .open = lstats_open, 567 .read = seq_read, 568 .write = lstats_write, 569 .llseek = seq_lseek, 570 .release = single_release, 571 }; 572 573 #endif 574 575 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns, 576 struct pid *pid, struct task_struct *task) 577 { 578 unsigned long totalpages = totalram_pages + total_swap_pages; 579 unsigned long points = 0; 580 581 read_lock(&tasklist_lock); 582 if (pid_alive(task)) 583 points = oom_badness(task, NULL, NULL, totalpages) * 584 1000 / totalpages; 585 read_unlock(&tasklist_lock); 586 seq_printf(m, "%lu\n", points); 587 588 return 0; 589 } 590 591 struct limit_names { 592 const char *name; 593 const char *unit; 594 }; 595 596 static const struct limit_names lnames[RLIM_NLIMITS] = { 597 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 598 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 599 [RLIMIT_DATA] = {"Max data size", "bytes"}, 600 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 601 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 602 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 603 [RLIMIT_NPROC] = {"Max processes", "processes"}, 604 [RLIMIT_NOFILE] = {"Max open files", "files"}, 605 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 606 [RLIMIT_AS] = {"Max address space", "bytes"}, 607 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 608 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 609 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 610 [RLIMIT_NICE] = {"Max nice priority", NULL}, 611 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 612 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 613 }; 614 615 /* Display limits for a process */ 616 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns, 617 struct pid *pid, struct task_struct *task) 618 { 619 unsigned int i; 620 unsigned long flags; 621 622 struct rlimit rlim[RLIM_NLIMITS]; 623 624 if (!lock_task_sighand(task, &flags)) 625 return 0; 626 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 627 unlock_task_sighand(task, &flags); 628 629 /* 630 * print the file header 631 */ 632 seq_printf(m, "%-25s %-20s %-20s %-10s\n", 633 "Limit", "Soft Limit", "Hard Limit", "Units"); 634 635 for (i = 0; i < RLIM_NLIMITS; i++) { 636 if (rlim[i].rlim_cur == RLIM_INFINITY) 637 seq_printf(m, "%-25s %-20s ", 638 lnames[i].name, "unlimited"); 639 else 640 seq_printf(m, "%-25s %-20lu ", 641 lnames[i].name, rlim[i].rlim_cur); 642 643 if (rlim[i].rlim_max == RLIM_INFINITY) 644 seq_printf(m, "%-20s ", "unlimited"); 645 else 646 seq_printf(m, "%-20lu ", rlim[i].rlim_max); 647 648 if (lnames[i].unit) 649 seq_printf(m, "%-10s\n", lnames[i].unit); 650 else 651 seq_putc(m, '\n'); 652 } 653 654 return 0; 655 } 656 657 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 658 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns, 659 struct pid *pid, struct task_struct *task) 660 { 661 long nr; 662 unsigned long args[6], sp, pc; 663 int res; 664 665 res = lock_trace(task); 666 if (res) 667 return res; 668 669 if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) 670 seq_puts(m, "running\n"); 671 else if (nr < 0) 672 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc); 673 else 674 seq_printf(m, 675 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", 676 nr, 677 args[0], args[1], args[2], args[3], args[4], args[5], 678 sp, pc); 679 unlock_trace(task); 680 681 return 0; 682 } 683 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 684 685 /************************************************************************/ 686 /* Here the fs part begins */ 687 /************************************************************************/ 688 689 /* permission checks */ 690 static int proc_fd_access_allowed(struct inode *inode) 691 { 692 struct task_struct *task; 693 int allowed = 0; 694 /* Allow access to a task's file descriptors if it is us or we 695 * may use ptrace attach to the process and find out that 696 * information. 697 */ 698 task = get_proc_task(inode); 699 if (task) { 700 allowed = ptrace_may_access(task, PTRACE_MODE_READ); 701 put_task_struct(task); 702 } 703 return allowed; 704 } 705 706 int proc_setattr(struct dentry *dentry, struct iattr *attr) 707 { 708 int error; 709 struct inode *inode = d_inode(dentry); 710 711 if (attr->ia_valid & ATTR_MODE) 712 return -EPERM; 713 714 error = inode_change_ok(inode, attr); 715 if (error) 716 return error; 717 718 setattr_copy(inode, attr); 719 mark_inode_dirty(inode); 720 return 0; 721 } 722 723 /* 724 * May current process learn task's sched/cmdline info (for hide_pid_min=1) 725 * or euid/egid (for hide_pid_min=2)? 726 */ 727 static bool has_pid_permissions(struct pid_namespace *pid, 728 struct task_struct *task, 729 int hide_pid_min) 730 { 731 if (pid->hide_pid < hide_pid_min) 732 return true; 733 if (in_group_p(pid->pid_gid)) 734 return true; 735 return ptrace_may_access(task, PTRACE_MODE_READ); 736 } 737 738 739 static int proc_pid_permission(struct inode *inode, int mask) 740 { 741 struct pid_namespace *pid = inode->i_sb->s_fs_info; 742 struct task_struct *task; 743 bool has_perms; 744 745 task = get_proc_task(inode); 746 if (!task) 747 return -ESRCH; 748 has_perms = has_pid_permissions(pid, task, 1); 749 put_task_struct(task); 750 751 if (!has_perms) { 752 if (pid->hide_pid == 2) { 753 /* 754 * Let's make getdents(), stat(), and open() 755 * consistent with each other. If a process 756 * may not stat() a file, it shouldn't be seen 757 * in procfs at all. 758 */ 759 return -ENOENT; 760 } 761 762 return -EPERM; 763 } 764 return generic_permission(inode, mask); 765 } 766 767 768 769 static const struct inode_operations proc_def_inode_operations = { 770 .setattr = proc_setattr, 771 }; 772 773 static int proc_single_show(struct seq_file *m, void *v) 774 { 775 struct inode *inode = m->private; 776 struct pid_namespace *ns; 777 struct pid *pid; 778 struct task_struct *task; 779 int ret; 780 781 ns = inode->i_sb->s_fs_info; 782 pid = proc_pid(inode); 783 task = get_pid_task(pid, PIDTYPE_PID); 784 if (!task) 785 return -ESRCH; 786 787 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 788 789 put_task_struct(task); 790 return ret; 791 } 792 793 static int proc_single_open(struct inode *inode, struct file *filp) 794 { 795 return single_open(filp, proc_single_show, inode); 796 } 797 798 static const struct file_operations proc_single_file_operations = { 799 .open = proc_single_open, 800 .read = seq_read, 801 .llseek = seq_lseek, 802 .release = single_release, 803 }; 804 805 806 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode) 807 { 808 struct task_struct *task = get_proc_task(inode); 809 struct mm_struct *mm = ERR_PTR(-ESRCH); 810 811 if (task) { 812 mm = mm_access(task, mode); 813 put_task_struct(task); 814 815 if (!IS_ERR_OR_NULL(mm)) { 816 /* ensure this mm_struct can't be freed */ 817 atomic_inc(&mm->mm_count); 818 /* but do not pin its memory */ 819 mmput(mm); 820 } 821 } 822 823 return mm; 824 } 825 826 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) 827 { 828 struct mm_struct *mm = proc_mem_open(inode, mode); 829 830 if (IS_ERR(mm)) 831 return PTR_ERR(mm); 832 833 file->private_data = mm; 834 return 0; 835 } 836 837 static int mem_open(struct inode *inode, struct file *file) 838 { 839 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH); 840 841 /* OK to pass negative loff_t, we can catch out-of-range */ 842 file->f_mode |= FMODE_UNSIGNED_OFFSET; 843 844 return ret; 845 } 846 847 static ssize_t mem_rw(struct file *file, char __user *buf, 848 size_t count, loff_t *ppos, int write) 849 { 850 struct mm_struct *mm = file->private_data; 851 unsigned long addr = *ppos; 852 ssize_t copied; 853 char *page; 854 855 if (!mm) 856 return 0; 857 858 page = (char *)__get_free_page(GFP_TEMPORARY); 859 if (!page) 860 return -ENOMEM; 861 862 copied = 0; 863 if (!atomic_inc_not_zero(&mm->mm_users)) 864 goto free; 865 866 while (count > 0) { 867 int this_len = min_t(int, count, PAGE_SIZE); 868 869 if (write && copy_from_user(page, buf, this_len)) { 870 copied = -EFAULT; 871 break; 872 } 873 874 this_len = access_remote_vm(mm, addr, page, this_len, write); 875 if (!this_len) { 876 if (!copied) 877 copied = -EIO; 878 break; 879 } 880 881 if (!write && copy_to_user(buf, page, this_len)) { 882 copied = -EFAULT; 883 break; 884 } 885 886 buf += this_len; 887 addr += this_len; 888 copied += this_len; 889 count -= this_len; 890 } 891 *ppos = addr; 892 893 mmput(mm); 894 free: 895 free_page((unsigned long) page); 896 return copied; 897 } 898 899 static ssize_t mem_read(struct file *file, char __user *buf, 900 size_t count, loff_t *ppos) 901 { 902 return mem_rw(file, buf, count, ppos, 0); 903 } 904 905 static ssize_t mem_write(struct file *file, const char __user *buf, 906 size_t count, loff_t *ppos) 907 { 908 return mem_rw(file, (char __user*)buf, count, ppos, 1); 909 } 910 911 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 912 { 913 switch (orig) { 914 case 0: 915 file->f_pos = offset; 916 break; 917 case 1: 918 file->f_pos += offset; 919 break; 920 default: 921 return -EINVAL; 922 } 923 force_successful_syscall_return(); 924 return file->f_pos; 925 } 926 927 static int mem_release(struct inode *inode, struct file *file) 928 { 929 struct mm_struct *mm = file->private_data; 930 if (mm) 931 mmdrop(mm); 932 return 0; 933 } 934 935 static const struct file_operations proc_mem_operations = { 936 .llseek = mem_lseek, 937 .read = mem_read, 938 .write = mem_write, 939 .open = mem_open, 940 .release = mem_release, 941 }; 942 943 static int environ_open(struct inode *inode, struct file *file) 944 { 945 return __mem_open(inode, file, PTRACE_MODE_READ); 946 } 947 948 static ssize_t environ_read(struct file *file, char __user *buf, 949 size_t count, loff_t *ppos) 950 { 951 char *page; 952 unsigned long src = *ppos; 953 int ret = 0; 954 struct mm_struct *mm = file->private_data; 955 956 if (!mm) 957 return 0; 958 959 page = (char *)__get_free_page(GFP_TEMPORARY); 960 if (!page) 961 return -ENOMEM; 962 963 ret = 0; 964 if (!atomic_inc_not_zero(&mm->mm_users)) 965 goto free; 966 while (count > 0) { 967 size_t this_len, max_len; 968 int retval; 969 970 if (src >= (mm->env_end - mm->env_start)) 971 break; 972 973 this_len = mm->env_end - (mm->env_start + src); 974 975 max_len = min_t(size_t, PAGE_SIZE, count); 976 this_len = min(max_len, this_len); 977 978 retval = access_remote_vm(mm, (mm->env_start + src), 979 page, this_len, 0); 980 981 if (retval <= 0) { 982 ret = retval; 983 break; 984 } 985 986 if (copy_to_user(buf, page, retval)) { 987 ret = -EFAULT; 988 break; 989 } 990 991 ret += retval; 992 src += retval; 993 buf += retval; 994 count -= retval; 995 } 996 *ppos = src; 997 mmput(mm); 998 999 free: 1000 free_page((unsigned long) page); 1001 return ret; 1002 } 1003 1004 static const struct file_operations proc_environ_operations = { 1005 .open = environ_open, 1006 .read = environ_read, 1007 .llseek = generic_file_llseek, 1008 .release = mem_release, 1009 }; 1010 1011 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count, 1012 loff_t *ppos) 1013 { 1014 struct task_struct *task = get_proc_task(file_inode(file)); 1015 char buffer[PROC_NUMBUF]; 1016 int oom_adj = OOM_ADJUST_MIN; 1017 size_t len; 1018 unsigned long flags; 1019 1020 if (!task) 1021 return -ESRCH; 1022 if (lock_task_sighand(task, &flags)) { 1023 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX) 1024 oom_adj = OOM_ADJUST_MAX; 1025 else 1026 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) / 1027 OOM_SCORE_ADJ_MAX; 1028 unlock_task_sighand(task, &flags); 1029 } 1030 put_task_struct(task); 1031 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj); 1032 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1033 } 1034 1035 /* 1036 * /proc/pid/oom_adj exists solely for backwards compatibility with previous 1037 * kernels. The effective policy is defined by oom_score_adj, which has a 1038 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly. 1039 * Values written to oom_adj are simply mapped linearly to oom_score_adj. 1040 * Processes that become oom disabled via oom_adj will still be oom disabled 1041 * with this implementation. 1042 * 1043 * oom_adj cannot be removed since existing userspace binaries use it. 1044 */ 1045 static ssize_t oom_adj_write(struct file *file, const char __user *buf, 1046 size_t count, loff_t *ppos) 1047 { 1048 struct task_struct *task; 1049 char buffer[PROC_NUMBUF]; 1050 int oom_adj; 1051 unsigned long flags; 1052 int err; 1053 1054 memset(buffer, 0, sizeof(buffer)); 1055 if (count > sizeof(buffer) - 1) 1056 count = sizeof(buffer) - 1; 1057 if (copy_from_user(buffer, buf, count)) { 1058 err = -EFAULT; 1059 goto out; 1060 } 1061 1062 err = kstrtoint(strstrip(buffer), 0, &oom_adj); 1063 if (err) 1064 goto out; 1065 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) && 1066 oom_adj != OOM_DISABLE) { 1067 err = -EINVAL; 1068 goto out; 1069 } 1070 1071 task = get_proc_task(file_inode(file)); 1072 if (!task) { 1073 err = -ESRCH; 1074 goto out; 1075 } 1076 1077 task_lock(task); 1078 if (!task->mm) { 1079 err = -EINVAL; 1080 goto err_task_lock; 1081 } 1082 1083 if (!lock_task_sighand(task, &flags)) { 1084 err = -ESRCH; 1085 goto err_task_lock; 1086 } 1087 1088 /* 1089 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 1090 * value is always attainable. 1091 */ 1092 if (oom_adj == OOM_ADJUST_MAX) 1093 oom_adj = OOM_SCORE_ADJ_MAX; 1094 else 1095 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE; 1096 1097 if (oom_adj < task->signal->oom_score_adj && 1098 !capable(CAP_SYS_RESOURCE)) { 1099 err = -EACCES; 1100 goto err_sighand; 1101 } 1102 1103 /* 1104 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use 1105 * /proc/pid/oom_score_adj instead. 1106 */ 1107 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 1108 current->comm, task_pid_nr(current), task_pid_nr(task), 1109 task_pid_nr(task)); 1110 1111 task->signal->oom_score_adj = oom_adj; 1112 trace_oom_score_adj_update(task); 1113 err_sighand: 1114 unlock_task_sighand(task, &flags); 1115 err_task_lock: 1116 task_unlock(task); 1117 put_task_struct(task); 1118 out: 1119 return err < 0 ? err : count; 1120 } 1121 1122 static const struct file_operations proc_oom_adj_operations = { 1123 .read = oom_adj_read, 1124 .write = oom_adj_write, 1125 .llseek = generic_file_llseek, 1126 }; 1127 1128 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 1129 size_t count, loff_t *ppos) 1130 { 1131 struct task_struct *task = get_proc_task(file_inode(file)); 1132 char buffer[PROC_NUMBUF]; 1133 short oom_score_adj = OOM_SCORE_ADJ_MIN; 1134 unsigned long flags; 1135 size_t len; 1136 1137 if (!task) 1138 return -ESRCH; 1139 if (lock_task_sighand(task, &flags)) { 1140 oom_score_adj = task->signal->oom_score_adj; 1141 unlock_task_sighand(task, &flags); 1142 } 1143 put_task_struct(task); 1144 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj); 1145 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1146 } 1147 1148 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1149 size_t count, loff_t *ppos) 1150 { 1151 struct task_struct *task; 1152 char buffer[PROC_NUMBUF]; 1153 unsigned long flags; 1154 int oom_score_adj; 1155 int err; 1156 1157 memset(buffer, 0, sizeof(buffer)); 1158 if (count > sizeof(buffer) - 1) 1159 count = sizeof(buffer) - 1; 1160 if (copy_from_user(buffer, buf, count)) { 1161 err = -EFAULT; 1162 goto out; 1163 } 1164 1165 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 1166 if (err) 1167 goto out; 1168 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1169 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1170 err = -EINVAL; 1171 goto out; 1172 } 1173 1174 task = get_proc_task(file_inode(file)); 1175 if (!task) { 1176 err = -ESRCH; 1177 goto out; 1178 } 1179 1180 task_lock(task); 1181 if (!task->mm) { 1182 err = -EINVAL; 1183 goto err_task_lock; 1184 } 1185 1186 if (!lock_task_sighand(task, &flags)) { 1187 err = -ESRCH; 1188 goto err_task_lock; 1189 } 1190 1191 if ((short)oom_score_adj < task->signal->oom_score_adj_min && 1192 !capable(CAP_SYS_RESOURCE)) { 1193 err = -EACCES; 1194 goto err_sighand; 1195 } 1196 1197 task->signal->oom_score_adj = (short)oom_score_adj; 1198 if (has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1199 task->signal->oom_score_adj_min = (short)oom_score_adj; 1200 trace_oom_score_adj_update(task); 1201 1202 err_sighand: 1203 unlock_task_sighand(task, &flags); 1204 err_task_lock: 1205 task_unlock(task); 1206 put_task_struct(task); 1207 out: 1208 return err < 0 ? err : count; 1209 } 1210 1211 static const struct file_operations proc_oom_score_adj_operations = { 1212 .read = oom_score_adj_read, 1213 .write = oom_score_adj_write, 1214 .llseek = default_llseek, 1215 }; 1216 1217 #ifdef CONFIG_AUDITSYSCALL 1218 #define TMPBUFLEN 21 1219 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1220 size_t count, loff_t *ppos) 1221 { 1222 struct inode * inode = file_inode(file); 1223 struct task_struct *task = get_proc_task(inode); 1224 ssize_t length; 1225 char tmpbuf[TMPBUFLEN]; 1226 1227 if (!task) 1228 return -ESRCH; 1229 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1230 from_kuid(file->f_cred->user_ns, 1231 audit_get_loginuid(task))); 1232 put_task_struct(task); 1233 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1234 } 1235 1236 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1237 size_t count, loff_t *ppos) 1238 { 1239 struct inode * inode = file_inode(file); 1240 uid_t loginuid; 1241 kuid_t kloginuid; 1242 int rv; 1243 1244 rcu_read_lock(); 1245 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1246 rcu_read_unlock(); 1247 return -EPERM; 1248 } 1249 rcu_read_unlock(); 1250 1251 if (*ppos != 0) { 1252 /* No partial writes. */ 1253 return -EINVAL; 1254 } 1255 1256 rv = kstrtou32_from_user(buf, count, 10, &loginuid); 1257 if (rv < 0) 1258 return rv; 1259 1260 /* is userspace tring to explicitly UNSET the loginuid? */ 1261 if (loginuid == AUDIT_UID_UNSET) { 1262 kloginuid = INVALID_UID; 1263 } else { 1264 kloginuid = make_kuid(file->f_cred->user_ns, loginuid); 1265 if (!uid_valid(kloginuid)) 1266 return -EINVAL; 1267 } 1268 1269 rv = audit_set_loginuid(kloginuid); 1270 if (rv < 0) 1271 return rv; 1272 return count; 1273 } 1274 1275 static const struct file_operations proc_loginuid_operations = { 1276 .read = proc_loginuid_read, 1277 .write = proc_loginuid_write, 1278 .llseek = generic_file_llseek, 1279 }; 1280 1281 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1282 size_t count, loff_t *ppos) 1283 { 1284 struct inode * inode = file_inode(file); 1285 struct task_struct *task = get_proc_task(inode); 1286 ssize_t length; 1287 char tmpbuf[TMPBUFLEN]; 1288 1289 if (!task) 1290 return -ESRCH; 1291 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1292 audit_get_sessionid(task)); 1293 put_task_struct(task); 1294 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1295 } 1296 1297 static const struct file_operations proc_sessionid_operations = { 1298 .read = proc_sessionid_read, 1299 .llseek = generic_file_llseek, 1300 }; 1301 #endif 1302 1303 #ifdef CONFIG_FAULT_INJECTION 1304 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1305 size_t count, loff_t *ppos) 1306 { 1307 struct task_struct *task = get_proc_task(file_inode(file)); 1308 char buffer[PROC_NUMBUF]; 1309 size_t len; 1310 int make_it_fail; 1311 1312 if (!task) 1313 return -ESRCH; 1314 make_it_fail = task->make_it_fail; 1315 put_task_struct(task); 1316 1317 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1318 1319 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1320 } 1321 1322 static ssize_t proc_fault_inject_write(struct file * file, 1323 const char __user * buf, size_t count, loff_t *ppos) 1324 { 1325 struct task_struct *task; 1326 char buffer[PROC_NUMBUF]; 1327 int make_it_fail; 1328 int rv; 1329 1330 if (!capable(CAP_SYS_RESOURCE)) 1331 return -EPERM; 1332 memset(buffer, 0, sizeof(buffer)); 1333 if (count > sizeof(buffer) - 1) 1334 count = sizeof(buffer) - 1; 1335 if (copy_from_user(buffer, buf, count)) 1336 return -EFAULT; 1337 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail); 1338 if (rv < 0) 1339 return rv; 1340 if (make_it_fail < 0 || make_it_fail > 1) 1341 return -EINVAL; 1342 1343 task = get_proc_task(file_inode(file)); 1344 if (!task) 1345 return -ESRCH; 1346 task->make_it_fail = make_it_fail; 1347 put_task_struct(task); 1348 1349 return count; 1350 } 1351 1352 static const struct file_operations proc_fault_inject_operations = { 1353 .read = proc_fault_inject_read, 1354 .write = proc_fault_inject_write, 1355 .llseek = generic_file_llseek, 1356 }; 1357 #endif 1358 1359 1360 #ifdef CONFIG_SCHED_DEBUG 1361 /* 1362 * Print out various scheduling related per-task fields: 1363 */ 1364 static int sched_show(struct seq_file *m, void *v) 1365 { 1366 struct inode *inode = m->private; 1367 struct task_struct *p; 1368 1369 p = get_proc_task(inode); 1370 if (!p) 1371 return -ESRCH; 1372 proc_sched_show_task(p, m); 1373 1374 put_task_struct(p); 1375 1376 return 0; 1377 } 1378 1379 static ssize_t 1380 sched_write(struct file *file, const char __user *buf, 1381 size_t count, loff_t *offset) 1382 { 1383 struct inode *inode = file_inode(file); 1384 struct task_struct *p; 1385 1386 p = get_proc_task(inode); 1387 if (!p) 1388 return -ESRCH; 1389 proc_sched_set_task(p); 1390 1391 put_task_struct(p); 1392 1393 return count; 1394 } 1395 1396 static int sched_open(struct inode *inode, struct file *filp) 1397 { 1398 return single_open(filp, sched_show, inode); 1399 } 1400 1401 static const struct file_operations proc_pid_sched_operations = { 1402 .open = sched_open, 1403 .read = seq_read, 1404 .write = sched_write, 1405 .llseek = seq_lseek, 1406 .release = single_release, 1407 }; 1408 1409 #endif 1410 1411 #ifdef CONFIG_SCHED_AUTOGROUP 1412 /* 1413 * Print out autogroup related information: 1414 */ 1415 static int sched_autogroup_show(struct seq_file *m, void *v) 1416 { 1417 struct inode *inode = m->private; 1418 struct task_struct *p; 1419 1420 p = get_proc_task(inode); 1421 if (!p) 1422 return -ESRCH; 1423 proc_sched_autogroup_show_task(p, m); 1424 1425 put_task_struct(p); 1426 1427 return 0; 1428 } 1429 1430 static ssize_t 1431 sched_autogroup_write(struct file *file, const char __user *buf, 1432 size_t count, loff_t *offset) 1433 { 1434 struct inode *inode = file_inode(file); 1435 struct task_struct *p; 1436 char buffer[PROC_NUMBUF]; 1437 int nice; 1438 int err; 1439 1440 memset(buffer, 0, sizeof(buffer)); 1441 if (count > sizeof(buffer) - 1) 1442 count = sizeof(buffer) - 1; 1443 if (copy_from_user(buffer, buf, count)) 1444 return -EFAULT; 1445 1446 err = kstrtoint(strstrip(buffer), 0, &nice); 1447 if (err < 0) 1448 return err; 1449 1450 p = get_proc_task(inode); 1451 if (!p) 1452 return -ESRCH; 1453 1454 err = proc_sched_autogroup_set_nice(p, nice); 1455 if (err) 1456 count = err; 1457 1458 put_task_struct(p); 1459 1460 return count; 1461 } 1462 1463 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1464 { 1465 int ret; 1466 1467 ret = single_open(filp, sched_autogroup_show, NULL); 1468 if (!ret) { 1469 struct seq_file *m = filp->private_data; 1470 1471 m->private = inode; 1472 } 1473 return ret; 1474 } 1475 1476 static const struct file_operations proc_pid_sched_autogroup_operations = { 1477 .open = sched_autogroup_open, 1478 .read = seq_read, 1479 .write = sched_autogroup_write, 1480 .llseek = seq_lseek, 1481 .release = single_release, 1482 }; 1483 1484 #endif /* CONFIG_SCHED_AUTOGROUP */ 1485 1486 static ssize_t comm_write(struct file *file, const char __user *buf, 1487 size_t count, loff_t *offset) 1488 { 1489 struct inode *inode = file_inode(file); 1490 struct task_struct *p; 1491 char buffer[TASK_COMM_LEN]; 1492 const size_t maxlen = sizeof(buffer) - 1; 1493 1494 memset(buffer, 0, sizeof(buffer)); 1495 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count)) 1496 return -EFAULT; 1497 1498 p = get_proc_task(inode); 1499 if (!p) 1500 return -ESRCH; 1501 1502 if (same_thread_group(current, p)) 1503 set_task_comm(p, buffer); 1504 else 1505 count = -EINVAL; 1506 1507 put_task_struct(p); 1508 1509 return count; 1510 } 1511 1512 static int comm_show(struct seq_file *m, void *v) 1513 { 1514 struct inode *inode = m->private; 1515 struct task_struct *p; 1516 1517 p = get_proc_task(inode); 1518 if (!p) 1519 return -ESRCH; 1520 1521 task_lock(p); 1522 seq_printf(m, "%s\n", p->comm); 1523 task_unlock(p); 1524 1525 put_task_struct(p); 1526 1527 return 0; 1528 } 1529 1530 static int comm_open(struct inode *inode, struct file *filp) 1531 { 1532 return single_open(filp, comm_show, inode); 1533 } 1534 1535 static const struct file_operations proc_pid_set_comm_operations = { 1536 .open = comm_open, 1537 .read = seq_read, 1538 .write = comm_write, 1539 .llseek = seq_lseek, 1540 .release = single_release, 1541 }; 1542 1543 static int proc_exe_link(struct dentry *dentry, struct path *exe_path) 1544 { 1545 struct task_struct *task; 1546 struct mm_struct *mm; 1547 struct file *exe_file; 1548 1549 task = get_proc_task(d_inode(dentry)); 1550 if (!task) 1551 return -ENOENT; 1552 mm = get_task_mm(task); 1553 put_task_struct(task); 1554 if (!mm) 1555 return -ENOENT; 1556 exe_file = get_mm_exe_file(mm); 1557 mmput(mm); 1558 if (exe_file) { 1559 *exe_path = exe_file->f_path; 1560 path_get(&exe_file->f_path); 1561 fput(exe_file); 1562 return 0; 1563 } else 1564 return -ENOENT; 1565 } 1566 1567 static const char *proc_pid_follow_link(struct dentry *dentry, void **cookie) 1568 { 1569 struct inode *inode = d_inode(dentry); 1570 struct path path; 1571 int error = -EACCES; 1572 1573 /* Are we allowed to snoop on the tasks file descriptors? */ 1574 if (!proc_fd_access_allowed(inode)) 1575 goto out; 1576 1577 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1578 if (error) 1579 goto out; 1580 1581 nd_jump_link(&path); 1582 return NULL; 1583 out: 1584 return ERR_PTR(error); 1585 } 1586 1587 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1588 { 1589 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1590 char *pathname; 1591 int len; 1592 1593 if (!tmp) 1594 return -ENOMEM; 1595 1596 pathname = d_path(path, tmp, PAGE_SIZE); 1597 len = PTR_ERR(pathname); 1598 if (IS_ERR(pathname)) 1599 goto out; 1600 len = tmp + PAGE_SIZE - 1 - pathname; 1601 1602 if (len > buflen) 1603 len = buflen; 1604 if (copy_to_user(buffer, pathname, len)) 1605 len = -EFAULT; 1606 out: 1607 free_page((unsigned long)tmp); 1608 return len; 1609 } 1610 1611 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1612 { 1613 int error = -EACCES; 1614 struct inode *inode = d_inode(dentry); 1615 struct path path; 1616 1617 /* Are we allowed to snoop on the tasks file descriptors? */ 1618 if (!proc_fd_access_allowed(inode)) 1619 goto out; 1620 1621 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1622 if (error) 1623 goto out; 1624 1625 error = do_proc_readlink(&path, buffer, buflen); 1626 path_put(&path); 1627 out: 1628 return error; 1629 } 1630 1631 const struct inode_operations proc_pid_link_inode_operations = { 1632 .readlink = proc_pid_readlink, 1633 .follow_link = proc_pid_follow_link, 1634 .setattr = proc_setattr, 1635 }; 1636 1637 1638 /* building an inode */ 1639 1640 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1641 { 1642 struct inode * inode; 1643 struct proc_inode *ei; 1644 const struct cred *cred; 1645 1646 /* We need a new inode */ 1647 1648 inode = new_inode(sb); 1649 if (!inode) 1650 goto out; 1651 1652 /* Common stuff */ 1653 ei = PROC_I(inode); 1654 inode->i_ino = get_next_ino(); 1655 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1656 inode->i_op = &proc_def_inode_operations; 1657 1658 /* 1659 * grab the reference to task. 1660 */ 1661 ei->pid = get_task_pid(task, PIDTYPE_PID); 1662 if (!ei->pid) 1663 goto out_unlock; 1664 1665 if (task_dumpable(task)) { 1666 rcu_read_lock(); 1667 cred = __task_cred(task); 1668 inode->i_uid = cred->euid; 1669 inode->i_gid = cred->egid; 1670 rcu_read_unlock(); 1671 } 1672 security_task_to_inode(task, inode); 1673 1674 out: 1675 return inode; 1676 1677 out_unlock: 1678 iput(inode); 1679 return NULL; 1680 } 1681 1682 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1683 { 1684 struct inode *inode = d_inode(dentry); 1685 struct task_struct *task; 1686 const struct cred *cred; 1687 struct pid_namespace *pid = dentry->d_sb->s_fs_info; 1688 1689 generic_fillattr(inode, stat); 1690 1691 rcu_read_lock(); 1692 stat->uid = GLOBAL_ROOT_UID; 1693 stat->gid = GLOBAL_ROOT_GID; 1694 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1695 if (task) { 1696 if (!has_pid_permissions(pid, task, 2)) { 1697 rcu_read_unlock(); 1698 /* 1699 * This doesn't prevent learning whether PID exists, 1700 * it only makes getattr() consistent with readdir(). 1701 */ 1702 return -ENOENT; 1703 } 1704 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1705 task_dumpable(task)) { 1706 cred = __task_cred(task); 1707 stat->uid = cred->euid; 1708 stat->gid = cred->egid; 1709 } 1710 } 1711 rcu_read_unlock(); 1712 return 0; 1713 } 1714 1715 /* dentry stuff */ 1716 1717 /* 1718 * Exceptional case: normally we are not allowed to unhash a busy 1719 * directory. In this case, however, we can do it - no aliasing problems 1720 * due to the way we treat inodes. 1721 * 1722 * Rewrite the inode's ownerships here because the owning task may have 1723 * performed a setuid(), etc. 1724 * 1725 * Before the /proc/pid/status file was created the only way to read 1726 * the effective uid of a /process was to stat /proc/pid. Reading 1727 * /proc/pid/status is slow enough that procps and other packages 1728 * kept stating /proc/pid. To keep the rules in /proc simple I have 1729 * made this apply to all per process world readable and executable 1730 * directories. 1731 */ 1732 int pid_revalidate(struct dentry *dentry, unsigned int flags) 1733 { 1734 struct inode *inode; 1735 struct task_struct *task; 1736 const struct cred *cred; 1737 1738 if (flags & LOOKUP_RCU) 1739 return -ECHILD; 1740 1741 inode = d_inode(dentry); 1742 task = get_proc_task(inode); 1743 1744 if (task) { 1745 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1746 task_dumpable(task)) { 1747 rcu_read_lock(); 1748 cred = __task_cred(task); 1749 inode->i_uid = cred->euid; 1750 inode->i_gid = cred->egid; 1751 rcu_read_unlock(); 1752 } else { 1753 inode->i_uid = GLOBAL_ROOT_UID; 1754 inode->i_gid = GLOBAL_ROOT_GID; 1755 } 1756 inode->i_mode &= ~(S_ISUID | S_ISGID); 1757 security_task_to_inode(task, inode); 1758 put_task_struct(task); 1759 return 1; 1760 } 1761 return 0; 1762 } 1763 1764 static inline bool proc_inode_is_dead(struct inode *inode) 1765 { 1766 return !proc_pid(inode)->tasks[PIDTYPE_PID].first; 1767 } 1768 1769 int pid_delete_dentry(const struct dentry *dentry) 1770 { 1771 /* Is the task we represent dead? 1772 * If so, then don't put the dentry on the lru list, 1773 * kill it immediately. 1774 */ 1775 return proc_inode_is_dead(d_inode(dentry)); 1776 } 1777 1778 const struct dentry_operations pid_dentry_operations = 1779 { 1780 .d_revalidate = pid_revalidate, 1781 .d_delete = pid_delete_dentry, 1782 }; 1783 1784 /* Lookups */ 1785 1786 /* 1787 * Fill a directory entry. 1788 * 1789 * If possible create the dcache entry and derive our inode number and 1790 * file type from dcache entry. 1791 * 1792 * Since all of the proc inode numbers are dynamically generated, the inode 1793 * numbers do not exist until the inode is cache. This means creating the 1794 * the dcache entry in readdir is necessary to keep the inode numbers 1795 * reported by readdir in sync with the inode numbers reported 1796 * by stat. 1797 */ 1798 bool proc_fill_cache(struct file *file, struct dir_context *ctx, 1799 const char *name, int len, 1800 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1801 { 1802 struct dentry *child, *dir = file->f_path.dentry; 1803 struct qstr qname = QSTR_INIT(name, len); 1804 struct inode *inode; 1805 unsigned type; 1806 ino_t ino; 1807 1808 child = d_hash_and_lookup(dir, &qname); 1809 if (!child) { 1810 child = d_alloc(dir, &qname); 1811 if (!child) 1812 goto end_instantiate; 1813 if (instantiate(d_inode(dir), child, task, ptr) < 0) { 1814 dput(child); 1815 goto end_instantiate; 1816 } 1817 } 1818 inode = d_inode(child); 1819 ino = inode->i_ino; 1820 type = inode->i_mode >> 12; 1821 dput(child); 1822 return dir_emit(ctx, name, len, ino, type); 1823 1824 end_instantiate: 1825 return dir_emit(ctx, name, len, 1, DT_UNKNOWN); 1826 } 1827 1828 /* 1829 * dname_to_vma_addr - maps a dentry name into two unsigned longs 1830 * which represent vma start and end addresses. 1831 */ 1832 static int dname_to_vma_addr(struct dentry *dentry, 1833 unsigned long *start, unsigned long *end) 1834 { 1835 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2) 1836 return -EINVAL; 1837 1838 return 0; 1839 } 1840 1841 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags) 1842 { 1843 unsigned long vm_start, vm_end; 1844 bool exact_vma_exists = false; 1845 struct mm_struct *mm = NULL; 1846 struct task_struct *task; 1847 const struct cred *cred; 1848 struct inode *inode; 1849 int status = 0; 1850 1851 if (flags & LOOKUP_RCU) 1852 return -ECHILD; 1853 1854 inode = d_inode(dentry); 1855 task = get_proc_task(inode); 1856 if (!task) 1857 goto out_notask; 1858 1859 mm = mm_access(task, PTRACE_MODE_READ); 1860 if (IS_ERR_OR_NULL(mm)) 1861 goto out; 1862 1863 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 1864 down_read(&mm->mmap_sem); 1865 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end); 1866 up_read(&mm->mmap_sem); 1867 } 1868 1869 mmput(mm); 1870 1871 if (exact_vma_exists) { 1872 if (task_dumpable(task)) { 1873 rcu_read_lock(); 1874 cred = __task_cred(task); 1875 inode->i_uid = cred->euid; 1876 inode->i_gid = cred->egid; 1877 rcu_read_unlock(); 1878 } else { 1879 inode->i_uid = GLOBAL_ROOT_UID; 1880 inode->i_gid = GLOBAL_ROOT_GID; 1881 } 1882 security_task_to_inode(task, inode); 1883 status = 1; 1884 } 1885 1886 out: 1887 put_task_struct(task); 1888 1889 out_notask: 1890 return status; 1891 } 1892 1893 static const struct dentry_operations tid_map_files_dentry_operations = { 1894 .d_revalidate = map_files_d_revalidate, 1895 .d_delete = pid_delete_dentry, 1896 }; 1897 1898 static int proc_map_files_get_link(struct dentry *dentry, struct path *path) 1899 { 1900 unsigned long vm_start, vm_end; 1901 struct vm_area_struct *vma; 1902 struct task_struct *task; 1903 struct mm_struct *mm; 1904 int rc; 1905 1906 rc = -ENOENT; 1907 task = get_proc_task(d_inode(dentry)); 1908 if (!task) 1909 goto out; 1910 1911 mm = get_task_mm(task); 1912 put_task_struct(task); 1913 if (!mm) 1914 goto out; 1915 1916 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 1917 if (rc) 1918 goto out_mmput; 1919 1920 rc = -ENOENT; 1921 down_read(&mm->mmap_sem); 1922 vma = find_exact_vma(mm, vm_start, vm_end); 1923 if (vma && vma->vm_file) { 1924 *path = vma->vm_file->f_path; 1925 path_get(path); 1926 rc = 0; 1927 } 1928 up_read(&mm->mmap_sem); 1929 1930 out_mmput: 1931 mmput(mm); 1932 out: 1933 return rc; 1934 } 1935 1936 struct map_files_info { 1937 fmode_t mode; 1938 unsigned long len; 1939 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */ 1940 }; 1941 1942 /* 1943 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the 1944 * symlinks may be used to bypass permissions on ancestor directories in the 1945 * path to the file in question. 1946 */ 1947 static const char * 1948 proc_map_files_follow_link(struct dentry *dentry, void **cookie) 1949 { 1950 if (!capable(CAP_SYS_ADMIN)) 1951 return ERR_PTR(-EPERM); 1952 1953 return proc_pid_follow_link(dentry, NULL); 1954 } 1955 1956 /* 1957 * Identical to proc_pid_link_inode_operations except for follow_link() 1958 */ 1959 static const struct inode_operations proc_map_files_link_inode_operations = { 1960 .readlink = proc_pid_readlink, 1961 .follow_link = proc_map_files_follow_link, 1962 .setattr = proc_setattr, 1963 }; 1964 1965 static int 1966 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry, 1967 struct task_struct *task, const void *ptr) 1968 { 1969 fmode_t mode = (fmode_t)(unsigned long)ptr; 1970 struct proc_inode *ei; 1971 struct inode *inode; 1972 1973 inode = proc_pid_make_inode(dir->i_sb, task); 1974 if (!inode) 1975 return -ENOENT; 1976 1977 ei = PROC_I(inode); 1978 ei->op.proc_get_link = proc_map_files_get_link; 1979 1980 inode->i_op = &proc_map_files_link_inode_operations; 1981 inode->i_size = 64; 1982 inode->i_mode = S_IFLNK; 1983 1984 if (mode & FMODE_READ) 1985 inode->i_mode |= S_IRUSR; 1986 if (mode & FMODE_WRITE) 1987 inode->i_mode |= S_IWUSR; 1988 1989 d_set_d_op(dentry, &tid_map_files_dentry_operations); 1990 d_add(dentry, inode); 1991 1992 return 0; 1993 } 1994 1995 static struct dentry *proc_map_files_lookup(struct inode *dir, 1996 struct dentry *dentry, unsigned int flags) 1997 { 1998 unsigned long vm_start, vm_end; 1999 struct vm_area_struct *vma; 2000 struct task_struct *task; 2001 int result; 2002 struct mm_struct *mm; 2003 2004 result = -ENOENT; 2005 task = get_proc_task(dir); 2006 if (!task) 2007 goto out; 2008 2009 result = -EACCES; 2010 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 2011 goto out_put_task; 2012 2013 result = -ENOENT; 2014 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 2015 goto out_put_task; 2016 2017 mm = get_task_mm(task); 2018 if (!mm) 2019 goto out_put_task; 2020 2021 down_read(&mm->mmap_sem); 2022 vma = find_exact_vma(mm, vm_start, vm_end); 2023 if (!vma) 2024 goto out_no_vma; 2025 2026 if (vma->vm_file) 2027 result = proc_map_files_instantiate(dir, dentry, task, 2028 (void *)(unsigned long)vma->vm_file->f_mode); 2029 2030 out_no_vma: 2031 up_read(&mm->mmap_sem); 2032 mmput(mm); 2033 out_put_task: 2034 put_task_struct(task); 2035 out: 2036 return ERR_PTR(result); 2037 } 2038 2039 static const struct inode_operations proc_map_files_inode_operations = { 2040 .lookup = proc_map_files_lookup, 2041 .permission = proc_fd_permission, 2042 .setattr = proc_setattr, 2043 }; 2044 2045 static int 2046 proc_map_files_readdir(struct file *file, struct dir_context *ctx) 2047 { 2048 struct vm_area_struct *vma; 2049 struct task_struct *task; 2050 struct mm_struct *mm; 2051 unsigned long nr_files, pos, i; 2052 struct flex_array *fa = NULL; 2053 struct map_files_info info; 2054 struct map_files_info *p; 2055 int ret; 2056 2057 ret = -ENOENT; 2058 task = get_proc_task(file_inode(file)); 2059 if (!task) 2060 goto out; 2061 2062 ret = -EACCES; 2063 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 2064 goto out_put_task; 2065 2066 ret = 0; 2067 if (!dir_emit_dots(file, ctx)) 2068 goto out_put_task; 2069 2070 mm = get_task_mm(task); 2071 if (!mm) 2072 goto out_put_task; 2073 down_read(&mm->mmap_sem); 2074 2075 nr_files = 0; 2076 2077 /* 2078 * We need two passes here: 2079 * 2080 * 1) Collect vmas of mapped files with mmap_sem taken 2081 * 2) Release mmap_sem and instantiate entries 2082 * 2083 * otherwise we get lockdep complained, since filldir() 2084 * routine might require mmap_sem taken in might_fault(). 2085 */ 2086 2087 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 2088 if (vma->vm_file && ++pos > ctx->pos) 2089 nr_files++; 2090 } 2091 2092 if (nr_files) { 2093 fa = flex_array_alloc(sizeof(info), nr_files, 2094 GFP_KERNEL); 2095 if (!fa || flex_array_prealloc(fa, 0, nr_files, 2096 GFP_KERNEL)) { 2097 ret = -ENOMEM; 2098 if (fa) 2099 flex_array_free(fa); 2100 up_read(&mm->mmap_sem); 2101 mmput(mm); 2102 goto out_put_task; 2103 } 2104 for (i = 0, vma = mm->mmap, pos = 2; vma; 2105 vma = vma->vm_next) { 2106 if (!vma->vm_file) 2107 continue; 2108 if (++pos <= ctx->pos) 2109 continue; 2110 2111 info.mode = vma->vm_file->f_mode; 2112 info.len = snprintf(info.name, 2113 sizeof(info.name), "%lx-%lx", 2114 vma->vm_start, vma->vm_end); 2115 if (flex_array_put(fa, i++, &info, GFP_KERNEL)) 2116 BUG(); 2117 } 2118 } 2119 up_read(&mm->mmap_sem); 2120 2121 for (i = 0; i < nr_files; i++) { 2122 p = flex_array_get(fa, i); 2123 if (!proc_fill_cache(file, ctx, 2124 p->name, p->len, 2125 proc_map_files_instantiate, 2126 task, 2127 (void *)(unsigned long)p->mode)) 2128 break; 2129 ctx->pos++; 2130 } 2131 if (fa) 2132 flex_array_free(fa); 2133 mmput(mm); 2134 2135 out_put_task: 2136 put_task_struct(task); 2137 out: 2138 return ret; 2139 } 2140 2141 static const struct file_operations proc_map_files_operations = { 2142 .read = generic_read_dir, 2143 .iterate = proc_map_files_readdir, 2144 .llseek = default_llseek, 2145 }; 2146 2147 struct timers_private { 2148 struct pid *pid; 2149 struct task_struct *task; 2150 struct sighand_struct *sighand; 2151 struct pid_namespace *ns; 2152 unsigned long flags; 2153 }; 2154 2155 static void *timers_start(struct seq_file *m, loff_t *pos) 2156 { 2157 struct timers_private *tp = m->private; 2158 2159 tp->task = get_pid_task(tp->pid, PIDTYPE_PID); 2160 if (!tp->task) 2161 return ERR_PTR(-ESRCH); 2162 2163 tp->sighand = lock_task_sighand(tp->task, &tp->flags); 2164 if (!tp->sighand) 2165 return ERR_PTR(-ESRCH); 2166 2167 return seq_list_start(&tp->task->signal->posix_timers, *pos); 2168 } 2169 2170 static void *timers_next(struct seq_file *m, void *v, loff_t *pos) 2171 { 2172 struct timers_private *tp = m->private; 2173 return seq_list_next(v, &tp->task->signal->posix_timers, pos); 2174 } 2175 2176 static void timers_stop(struct seq_file *m, void *v) 2177 { 2178 struct timers_private *tp = m->private; 2179 2180 if (tp->sighand) { 2181 unlock_task_sighand(tp->task, &tp->flags); 2182 tp->sighand = NULL; 2183 } 2184 2185 if (tp->task) { 2186 put_task_struct(tp->task); 2187 tp->task = NULL; 2188 } 2189 } 2190 2191 static int show_timer(struct seq_file *m, void *v) 2192 { 2193 struct k_itimer *timer; 2194 struct timers_private *tp = m->private; 2195 int notify; 2196 static const char * const nstr[] = { 2197 [SIGEV_SIGNAL] = "signal", 2198 [SIGEV_NONE] = "none", 2199 [SIGEV_THREAD] = "thread", 2200 }; 2201 2202 timer = list_entry((struct list_head *)v, struct k_itimer, list); 2203 notify = timer->it_sigev_notify; 2204 2205 seq_printf(m, "ID: %d\n", timer->it_id); 2206 seq_printf(m, "signal: %d/%p\n", 2207 timer->sigq->info.si_signo, 2208 timer->sigq->info.si_value.sival_ptr); 2209 seq_printf(m, "notify: %s/%s.%d\n", 2210 nstr[notify & ~SIGEV_THREAD_ID], 2211 (notify & SIGEV_THREAD_ID) ? "tid" : "pid", 2212 pid_nr_ns(timer->it_pid, tp->ns)); 2213 seq_printf(m, "ClockID: %d\n", timer->it_clock); 2214 2215 return 0; 2216 } 2217 2218 static const struct seq_operations proc_timers_seq_ops = { 2219 .start = timers_start, 2220 .next = timers_next, 2221 .stop = timers_stop, 2222 .show = show_timer, 2223 }; 2224 2225 static int proc_timers_open(struct inode *inode, struct file *file) 2226 { 2227 struct timers_private *tp; 2228 2229 tp = __seq_open_private(file, &proc_timers_seq_ops, 2230 sizeof(struct timers_private)); 2231 if (!tp) 2232 return -ENOMEM; 2233 2234 tp->pid = proc_pid(inode); 2235 tp->ns = inode->i_sb->s_fs_info; 2236 return 0; 2237 } 2238 2239 static const struct file_operations proc_timers_operations = { 2240 .open = proc_timers_open, 2241 .read = seq_read, 2242 .llseek = seq_lseek, 2243 .release = seq_release_private, 2244 }; 2245 2246 static int proc_pident_instantiate(struct inode *dir, 2247 struct dentry *dentry, struct task_struct *task, const void *ptr) 2248 { 2249 const struct pid_entry *p = ptr; 2250 struct inode *inode; 2251 struct proc_inode *ei; 2252 2253 inode = proc_pid_make_inode(dir->i_sb, task); 2254 if (!inode) 2255 goto out; 2256 2257 ei = PROC_I(inode); 2258 inode->i_mode = p->mode; 2259 if (S_ISDIR(inode->i_mode)) 2260 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2261 if (p->iop) 2262 inode->i_op = p->iop; 2263 if (p->fop) 2264 inode->i_fop = p->fop; 2265 ei->op = p->op; 2266 d_set_d_op(dentry, &pid_dentry_operations); 2267 d_add(dentry, inode); 2268 /* Close the race of the process dying before we return the dentry */ 2269 if (pid_revalidate(dentry, 0)) 2270 return 0; 2271 out: 2272 return -ENOENT; 2273 } 2274 2275 static struct dentry *proc_pident_lookup(struct inode *dir, 2276 struct dentry *dentry, 2277 const struct pid_entry *ents, 2278 unsigned int nents) 2279 { 2280 int error; 2281 struct task_struct *task = get_proc_task(dir); 2282 const struct pid_entry *p, *last; 2283 2284 error = -ENOENT; 2285 2286 if (!task) 2287 goto out_no_task; 2288 2289 /* 2290 * Yes, it does not scale. And it should not. Don't add 2291 * new entries into /proc/<tgid>/ without very good reasons. 2292 */ 2293 last = &ents[nents - 1]; 2294 for (p = ents; p <= last; p++) { 2295 if (p->len != dentry->d_name.len) 2296 continue; 2297 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2298 break; 2299 } 2300 if (p > last) 2301 goto out; 2302 2303 error = proc_pident_instantiate(dir, dentry, task, p); 2304 out: 2305 put_task_struct(task); 2306 out_no_task: 2307 return ERR_PTR(error); 2308 } 2309 2310 static int proc_pident_readdir(struct file *file, struct dir_context *ctx, 2311 const struct pid_entry *ents, unsigned int nents) 2312 { 2313 struct task_struct *task = get_proc_task(file_inode(file)); 2314 const struct pid_entry *p; 2315 2316 if (!task) 2317 return -ENOENT; 2318 2319 if (!dir_emit_dots(file, ctx)) 2320 goto out; 2321 2322 if (ctx->pos >= nents + 2) 2323 goto out; 2324 2325 for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) { 2326 if (!proc_fill_cache(file, ctx, p->name, p->len, 2327 proc_pident_instantiate, task, p)) 2328 break; 2329 ctx->pos++; 2330 } 2331 out: 2332 put_task_struct(task); 2333 return 0; 2334 } 2335 2336 #ifdef CONFIG_SECURITY 2337 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2338 size_t count, loff_t *ppos) 2339 { 2340 struct inode * inode = file_inode(file); 2341 char *p = NULL; 2342 ssize_t length; 2343 struct task_struct *task = get_proc_task(inode); 2344 2345 if (!task) 2346 return -ESRCH; 2347 2348 length = security_getprocattr(task, 2349 (char*)file->f_path.dentry->d_name.name, 2350 &p); 2351 put_task_struct(task); 2352 if (length > 0) 2353 length = simple_read_from_buffer(buf, count, ppos, p, length); 2354 kfree(p); 2355 return length; 2356 } 2357 2358 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2359 size_t count, loff_t *ppos) 2360 { 2361 struct inode * inode = file_inode(file); 2362 char *page; 2363 ssize_t length; 2364 struct task_struct *task = get_proc_task(inode); 2365 2366 length = -ESRCH; 2367 if (!task) 2368 goto out_no_task; 2369 if (count > PAGE_SIZE) 2370 count = PAGE_SIZE; 2371 2372 /* No partial writes. */ 2373 length = -EINVAL; 2374 if (*ppos != 0) 2375 goto out; 2376 2377 length = -ENOMEM; 2378 page = (char*)__get_free_page(GFP_TEMPORARY); 2379 if (!page) 2380 goto out; 2381 2382 length = -EFAULT; 2383 if (copy_from_user(page, buf, count)) 2384 goto out_free; 2385 2386 /* Guard against adverse ptrace interaction */ 2387 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex); 2388 if (length < 0) 2389 goto out_free; 2390 2391 length = security_setprocattr(task, 2392 (char*)file->f_path.dentry->d_name.name, 2393 (void*)page, count); 2394 mutex_unlock(&task->signal->cred_guard_mutex); 2395 out_free: 2396 free_page((unsigned long) page); 2397 out: 2398 put_task_struct(task); 2399 out_no_task: 2400 return length; 2401 } 2402 2403 static const struct file_operations proc_pid_attr_operations = { 2404 .read = proc_pid_attr_read, 2405 .write = proc_pid_attr_write, 2406 .llseek = generic_file_llseek, 2407 }; 2408 2409 static const struct pid_entry attr_dir_stuff[] = { 2410 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2411 REG("prev", S_IRUGO, proc_pid_attr_operations), 2412 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2413 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2414 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2415 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2416 }; 2417 2418 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx) 2419 { 2420 return proc_pident_readdir(file, ctx, 2421 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2422 } 2423 2424 static const struct file_operations proc_attr_dir_operations = { 2425 .read = generic_read_dir, 2426 .iterate = proc_attr_dir_readdir, 2427 .llseek = default_llseek, 2428 }; 2429 2430 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2431 struct dentry *dentry, unsigned int flags) 2432 { 2433 return proc_pident_lookup(dir, dentry, 2434 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2435 } 2436 2437 static const struct inode_operations proc_attr_dir_inode_operations = { 2438 .lookup = proc_attr_dir_lookup, 2439 .getattr = pid_getattr, 2440 .setattr = proc_setattr, 2441 }; 2442 2443 #endif 2444 2445 #ifdef CONFIG_ELF_CORE 2446 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2447 size_t count, loff_t *ppos) 2448 { 2449 struct task_struct *task = get_proc_task(file_inode(file)); 2450 struct mm_struct *mm; 2451 char buffer[PROC_NUMBUF]; 2452 size_t len; 2453 int ret; 2454 2455 if (!task) 2456 return -ESRCH; 2457 2458 ret = 0; 2459 mm = get_task_mm(task); 2460 if (mm) { 2461 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2462 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2463 MMF_DUMP_FILTER_SHIFT)); 2464 mmput(mm); 2465 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2466 } 2467 2468 put_task_struct(task); 2469 2470 return ret; 2471 } 2472 2473 static ssize_t proc_coredump_filter_write(struct file *file, 2474 const char __user *buf, 2475 size_t count, 2476 loff_t *ppos) 2477 { 2478 struct task_struct *task; 2479 struct mm_struct *mm; 2480 unsigned int val; 2481 int ret; 2482 int i; 2483 unsigned long mask; 2484 2485 ret = kstrtouint_from_user(buf, count, 0, &val); 2486 if (ret < 0) 2487 return ret; 2488 2489 ret = -ESRCH; 2490 task = get_proc_task(file_inode(file)); 2491 if (!task) 2492 goto out_no_task; 2493 2494 mm = get_task_mm(task); 2495 if (!mm) 2496 goto out_no_mm; 2497 2498 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2499 if (val & mask) 2500 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2501 else 2502 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2503 } 2504 2505 mmput(mm); 2506 out_no_mm: 2507 put_task_struct(task); 2508 out_no_task: 2509 if (ret < 0) 2510 return ret; 2511 return count; 2512 } 2513 2514 static const struct file_operations proc_coredump_filter_operations = { 2515 .read = proc_coredump_filter_read, 2516 .write = proc_coredump_filter_write, 2517 .llseek = generic_file_llseek, 2518 }; 2519 #endif 2520 2521 #ifdef CONFIG_TASK_IO_ACCOUNTING 2522 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole) 2523 { 2524 struct task_io_accounting acct = task->ioac; 2525 unsigned long flags; 2526 int result; 2527 2528 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2529 if (result) 2530 return result; 2531 2532 if (!ptrace_may_access(task, PTRACE_MODE_READ)) { 2533 result = -EACCES; 2534 goto out_unlock; 2535 } 2536 2537 if (whole && lock_task_sighand(task, &flags)) { 2538 struct task_struct *t = task; 2539 2540 task_io_accounting_add(&acct, &task->signal->ioac); 2541 while_each_thread(task, t) 2542 task_io_accounting_add(&acct, &t->ioac); 2543 2544 unlock_task_sighand(task, &flags); 2545 } 2546 seq_printf(m, 2547 "rchar: %llu\n" 2548 "wchar: %llu\n" 2549 "syscr: %llu\n" 2550 "syscw: %llu\n" 2551 "read_bytes: %llu\n" 2552 "write_bytes: %llu\n" 2553 "cancelled_write_bytes: %llu\n", 2554 (unsigned long long)acct.rchar, 2555 (unsigned long long)acct.wchar, 2556 (unsigned long long)acct.syscr, 2557 (unsigned long long)acct.syscw, 2558 (unsigned long long)acct.read_bytes, 2559 (unsigned long long)acct.write_bytes, 2560 (unsigned long long)acct.cancelled_write_bytes); 2561 result = 0; 2562 2563 out_unlock: 2564 mutex_unlock(&task->signal->cred_guard_mutex); 2565 return result; 2566 } 2567 2568 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2569 struct pid *pid, struct task_struct *task) 2570 { 2571 return do_io_accounting(task, m, 0); 2572 } 2573 2574 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2575 struct pid *pid, struct task_struct *task) 2576 { 2577 return do_io_accounting(task, m, 1); 2578 } 2579 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2580 2581 #ifdef CONFIG_USER_NS 2582 static int proc_id_map_open(struct inode *inode, struct file *file, 2583 const struct seq_operations *seq_ops) 2584 { 2585 struct user_namespace *ns = NULL; 2586 struct task_struct *task; 2587 struct seq_file *seq; 2588 int ret = -EINVAL; 2589 2590 task = get_proc_task(inode); 2591 if (task) { 2592 rcu_read_lock(); 2593 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2594 rcu_read_unlock(); 2595 put_task_struct(task); 2596 } 2597 if (!ns) 2598 goto err; 2599 2600 ret = seq_open(file, seq_ops); 2601 if (ret) 2602 goto err_put_ns; 2603 2604 seq = file->private_data; 2605 seq->private = ns; 2606 2607 return 0; 2608 err_put_ns: 2609 put_user_ns(ns); 2610 err: 2611 return ret; 2612 } 2613 2614 static int proc_id_map_release(struct inode *inode, struct file *file) 2615 { 2616 struct seq_file *seq = file->private_data; 2617 struct user_namespace *ns = seq->private; 2618 put_user_ns(ns); 2619 return seq_release(inode, file); 2620 } 2621 2622 static int proc_uid_map_open(struct inode *inode, struct file *file) 2623 { 2624 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2625 } 2626 2627 static int proc_gid_map_open(struct inode *inode, struct file *file) 2628 { 2629 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2630 } 2631 2632 static int proc_projid_map_open(struct inode *inode, struct file *file) 2633 { 2634 return proc_id_map_open(inode, file, &proc_projid_seq_operations); 2635 } 2636 2637 static const struct file_operations proc_uid_map_operations = { 2638 .open = proc_uid_map_open, 2639 .write = proc_uid_map_write, 2640 .read = seq_read, 2641 .llseek = seq_lseek, 2642 .release = proc_id_map_release, 2643 }; 2644 2645 static const struct file_operations proc_gid_map_operations = { 2646 .open = proc_gid_map_open, 2647 .write = proc_gid_map_write, 2648 .read = seq_read, 2649 .llseek = seq_lseek, 2650 .release = proc_id_map_release, 2651 }; 2652 2653 static const struct file_operations proc_projid_map_operations = { 2654 .open = proc_projid_map_open, 2655 .write = proc_projid_map_write, 2656 .read = seq_read, 2657 .llseek = seq_lseek, 2658 .release = proc_id_map_release, 2659 }; 2660 2661 static int proc_setgroups_open(struct inode *inode, struct file *file) 2662 { 2663 struct user_namespace *ns = NULL; 2664 struct task_struct *task; 2665 int ret; 2666 2667 ret = -ESRCH; 2668 task = get_proc_task(inode); 2669 if (task) { 2670 rcu_read_lock(); 2671 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2672 rcu_read_unlock(); 2673 put_task_struct(task); 2674 } 2675 if (!ns) 2676 goto err; 2677 2678 if (file->f_mode & FMODE_WRITE) { 2679 ret = -EACCES; 2680 if (!ns_capable(ns, CAP_SYS_ADMIN)) 2681 goto err_put_ns; 2682 } 2683 2684 ret = single_open(file, &proc_setgroups_show, ns); 2685 if (ret) 2686 goto err_put_ns; 2687 2688 return 0; 2689 err_put_ns: 2690 put_user_ns(ns); 2691 err: 2692 return ret; 2693 } 2694 2695 static int proc_setgroups_release(struct inode *inode, struct file *file) 2696 { 2697 struct seq_file *seq = file->private_data; 2698 struct user_namespace *ns = seq->private; 2699 int ret = single_release(inode, file); 2700 put_user_ns(ns); 2701 return ret; 2702 } 2703 2704 static const struct file_operations proc_setgroups_operations = { 2705 .open = proc_setgroups_open, 2706 .write = proc_setgroups_write, 2707 .read = seq_read, 2708 .llseek = seq_lseek, 2709 .release = proc_setgroups_release, 2710 }; 2711 #endif /* CONFIG_USER_NS */ 2712 2713 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2714 struct pid *pid, struct task_struct *task) 2715 { 2716 int err = lock_trace(task); 2717 if (!err) { 2718 seq_printf(m, "%08x\n", task->personality); 2719 unlock_trace(task); 2720 } 2721 return err; 2722 } 2723 2724 /* 2725 * Thread groups 2726 */ 2727 static const struct file_operations proc_task_operations; 2728 static const struct inode_operations proc_task_inode_operations; 2729 2730 static const struct pid_entry tgid_base_stuff[] = { 2731 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2732 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2733 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 2734 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2735 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2736 #ifdef CONFIG_NET 2737 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2738 #endif 2739 REG("environ", S_IRUSR, proc_environ_operations), 2740 ONE("auxv", S_IRUSR, proc_pid_auxv), 2741 ONE("status", S_IRUGO, proc_pid_status), 2742 ONE("personality", S_IRUSR, proc_pid_personality), 2743 ONE("limits", S_IRUGO, proc_pid_limits), 2744 #ifdef CONFIG_SCHED_DEBUG 2745 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2746 #endif 2747 #ifdef CONFIG_SCHED_AUTOGROUP 2748 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2749 #endif 2750 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2751 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2752 ONE("syscall", S_IRUSR, proc_pid_syscall), 2753 #endif 2754 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 2755 ONE("stat", S_IRUGO, proc_tgid_stat), 2756 ONE("statm", S_IRUGO, proc_pid_statm), 2757 REG("maps", S_IRUGO, proc_pid_maps_operations), 2758 #ifdef CONFIG_NUMA 2759 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 2760 #endif 2761 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2762 LNK("cwd", proc_cwd_link), 2763 LNK("root", proc_root_link), 2764 LNK("exe", proc_exe_link), 2765 REG("mounts", S_IRUGO, proc_mounts_operations), 2766 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2767 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2768 #ifdef CONFIG_PROC_PAGE_MONITOR 2769 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2770 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 2771 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2772 #endif 2773 #ifdef CONFIG_SECURITY 2774 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2775 #endif 2776 #ifdef CONFIG_KALLSYMS 2777 ONE("wchan", S_IRUGO, proc_pid_wchan), 2778 #endif 2779 #ifdef CONFIG_STACKTRACE 2780 ONE("stack", S_IRUSR, proc_pid_stack), 2781 #endif 2782 #ifdef CONFIG_SCHED_INFO 2783 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 2784 #endif 2785 #ifdef CONFIG_LATENCYTOP 2786 REG("latency", S_IRUGO, proc_lstats_operations), 2787 #endif 2788 #ifdef CONFIG_PROC_PID_CPUSET 2789 ONE("cpuset", S_IRUGO, proc_cpuset_show), 2790 #endif 2791 #ifdef CONFIG_CGROUPS 2792 ONE("cgroup", S_IRUGO, proc_cgroup_show), 2793 #endif 2794 ONE("oom_score", S_IRUGO, proc_oom_score), 2795 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 2796 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2797 #ifdef CONFIG_AUDITSYSCALL 2798 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2799 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2800 #endif 2801 #ifdef CONFIG_FAULT_INJECTION 2802 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2803 #endif 2804 #ifdef CONFIG_ELF_CORE 2805 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2806 #endif 2807 #ifdef CONFIG_TASK_IO_ACCOUNTING 2808 ONE("io", S_IRUSR, proc_tgid_io_accounting), 2809 #endif 2810 #ifdef CONFIG_HARDWALL 2811 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 2812 #endif 2813 #ifdef CONFIG_USER_NS 2814 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 2815 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 2816 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 2817 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 2818 #endif 2819 #ifdef CONFIG_CHECKPOINT_RESTORE 2820 REG("timers", S_IRUGO, proc_timers_operations), 2821 #endif 2822 }; 2823 2824 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) 2825 { 2826 return proc_pident_readdir(file, ctx, 2827 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2828 } 2829 2830 static const struct file_operations proc_tgid_base_operations = { 2831 .read = generic_read_dir, 2832 .iterate = proc_tgid_base_readdir, 2833 .llseek = default_llseek, 2834 }; 2835 2836 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 2837 { 2838 return proc_pident_lookup(dir, dentry, 2839 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2840 } 2841 2842 static const struct inode_operations proc_tgid_base_inode_operations = { 2843 .lookup = proc_tgid_base_lookup, 2844 .getattr = pid_getattr, 2845 .setattr = proc_setattr, 2846 .permission = proc_pid_permission, 2847 }; 2848 2849 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2850 { 2851 struct dentry *dentry, *leader, *dir; 2852 char buf[PROC_NUMBUF]; 2853 struct qstr name; 2854 2855 name.name = buf; 2856 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2857 /* no ->d_hash() rejects on procfs */ 2858 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2859 if (dentry) { 2860 d_invalidate(dentry); 2861 dput(dentry); 2862 } 2863 2864 if (pid == tgid) 2865 return; 2866 2867 name.name = buf; 2868 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2869 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2870 if (!leader) 2871 goto out; 2872 2873 name.name = "task"; 2874 name.len = strlen(name.name); 2875 dir = d_hash_and_lookup(leader, &name); 2876 if (!dir) 2877 goto out_put_leader; 2878 2879 name.name = buf; 2880 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2881 dentry = d_hash_and_lookup(dir, &name); 2882 if (dentry) { 2883 d_invalidate(dentry); 2884 dput(dentry); 2885 } 2886 2887 dput(dir); 2888 out_put_leader: 2889 dput(leader); 2890 out: 2891 return; 2892 } 2893 2894 /** 2895 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2896 * @task: task that should be flushed. 2897 * 2898 * When flushing dentries from proc, one needs to flush them from global 2899 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2900 * in. This call is supposed to do all of this job. 2901 * 2902 * Looks in the dcache for 2903 * /proc/@pid 2904 * /proc/@tgid/task/@pid 2905 * if either directory is present flushes it and all of it'ts children 2906 * from the dcache. 2907 * 2908 * It is safe and reasonable to cache /proc entries for a task until 2909 * that task exits. After that they just clog up the dcache with 2910 * useless entries, possibly causing useful dcache entries to be 2911 * flushed instead. This routine is proved to flush those useless 2912 * dcache entries at process exit time. 2913 * 2914 * NOTE: This routine is just an optimization so it does not guarantee 2915 * that no dcache entries will exist at process exit time it 2916 * just makes it very unlikely that any will persist. 2917 */ 2918 2919 void proc_flush_task(struct task_struct *task) 2920 { 2921 int i; 2922 struct pid *pid, *tgid; 2923 struct upid *upid; 2924 2925 pid = task_pid(task); 2926 tgid = task_tgid(task); 2927 2928 for (i = 0; i <= pid->level; i++) { 2929 upid = &pid->numbers[i]; 2930 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 2931 tgid->numbers[i].nr); 2932 } 2933 } 2934 2935 static int proc_pid_instantiate(struct inode *dir, 2936 struct dentry * dentry, 2937 struct task_struct *task, const void *ptr) 2938 { 2939 struct inode *inode; 2940 2941 inode = proc_pid_make_inode(dir->i_sb, task); 2942 if (!inode) 2943 goto out; 2944 2945 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2946 inode->i_op = &proc_tgid_base_inode_operations; 2947 inode->i_fop = &proc_tgid_base_operations; 2948 inode->i_flags|=S_IMMUTABLE; 2949 2950 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff, 2951 ARRAY_SIZE(tgid_base_stuff))); 2952 2953 d_set_d_op(dentry, &pid_dentry_operations); 2954 2955 d_add(dentry, inode); 2956 /* Close the race of the process dying before we return the dentry */ 2957 if (pid_revalidate(dentry, 0)) 2958 return 0; 2959 out: 2960 return -ENOENT; 2961 } 2962 2963 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 2964 { 2965 int result = -ENOENT; 2966 struct task_struct *task; 2967 unsigned tgid; 2968 struct pid_namespace *ns; 2969 2970 tgid = name_to_int(&dentry->d_name); 2971 if (tgid == ~0U) 2972 goto out; 2973 2974 ns = dentry->d_sb->s_fs_info; 2975 rcu_read_lock(); 2976 task = find_task_by_pid_ns(tgid, ns); 2977 if (task) 2978 get_task_struct(task); 2979 rcu_read_unlock(); 2980 if (!task) 2981 goto out; 2982 2983 result = proc_pid_instantiate(dir, dentry, task, NULL); 2984 put_task_struct(task); 2985 out: 2986 return ERR_PTR(result); 2987 } 2988 2989 /* 2990 * Find the first task with tgid >= tgid 2991 * 2992 */ 2993 struct tgid_iter { 2994 unsigned int tgid; 2995 struct task_struct *task; 2996 }; 2997 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 2998 { 2999 struct pid *pid; 3000 3001 if (iter.task) 3002 put_task_struct(iter.task); 3003 rcu_read_lock(); 3004 retry: 3005 iter.task = NULL; 3006 pid = find_ge_pid(iter.tgid, ns); 3007 if (pid) { 3008 iter.tgid = pid_nr_ns(pid, ns); 3009 iter.task = pid_task(pid, PIDTYPE_PID); 3010 /* What we to know is if the pid we have find is the 3011 * pid of a thread_group_leader. Testing for task 3012 * being a thread_group_leader is the obvious thing 3013 * todo but there is a window when it fails, due to 3014 * the pid transfer logic in de_thread. 3015 * 3016 * So we perform the straight forward test of seeing 3017 * if the pid we have found is the pid of a thread 3018 * group leader, and don't worry if the task we have 3019 * found doesn't happen to be a thread group leader. 3020 * As we don't care in the case of readdir. 3021 */ 3022 if (!iter.task || !has_group_leader_pid(iter.task)) { 3023 iter.tgid += 1; 3024 goto retry; 3025 } 3026 get_task_struct(iter.task); 3027 } 3028 rcu_read_unlock(); 3029 return iter; 3030 } 3031 3032 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2) 3033 3034 /* for the /proc/ directory itself, after non-process stuff has been done */ 3035 int proc_pid_readdir(struct file *file, struct dir_context *ctx) 3036 { 3037 struct tgid_iter iter; 3038 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info; 3039 loff_t pos = ctx->pos; 3040 3041 if (pos >= PID_MAX_LIMIT + TGID_OFFSET) 3042 return 0; 3043 3044 if (pos == TGID_OFFSET - 2) { 3045 struct inode *inode = d_inode(ns->proc_self); 3046 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) 3047 return 0; 3048 ctx->pos = pos = pos + 1; 3049 } 3050 if (pos == TGID_OFFSET - 1) { 3051 struct inode *inode = d_inode(ns->proc_thread_self); 3052 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) 3053 return 0; 3054 ctx->pos = pos = pos + 1; 3055 } 3056 iter.tgid = pos - TGID_OFFSET; 3057 iter.task = NULL; 3058 for (iter = next_tgid(ns, iter); 3059 iter.task; 3060 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3061 char name[PROC_NUMBUF]; 3062 int len; 3063 if (!has_pid_permissions(ns, iter.task, 2)) 3064 continue; 3065 3066 len = snprintf(name, sizeof(name), "%d", iter.tgid); 3067 ctx->pos = iter.tgid + TGID_OFFSET; 3068 if (!proc_fill_cache(file, ctx, name, len, 3069 proc_pid_instantiate, iter.task, NULL)) { 3070 put_task_struct(iter.task); 3071 return 0; 3072 } 3073 } 3074 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET; 3075 return 0; 3076 } 3077 3078 /* 3079 * Tasks 3080 */ 3081 static const struct pid_entry tid_base_stuff[] = { 3082 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3083 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3084 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3085 #ifdef CONFIG_NET 3086 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3087 #endif 3088 REG("environ", S_IRUSR, proc_environ_operations), 3089 ONE("auxv", S_IRUSR, proc_pid_auxv), 3090 ONE("status", S_IRUGO, proc_pid_status), 3091 ONE("personality", S_IRUSR, proc_pid_personality), 3092 ONE("limits", S_IRUGO, proc_pid_limits), 3093 #ifdef CONFIG_SCHED_DEBUG 3094 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3095 #endif 3096 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3097 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3098 ONE("syscall", S_IRUSR, proc_pid_syscall), 3099 #endif 3100 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 3101 ONE("stat", S_IRUGO, proc_tid_stat), 3102 ONE("statm", S_IRUGO, proc_pid_statm), 3103 REG("maps", S_IRUGO, proc_tid_maps_operations), 3104 #ifdef CONFIG_PROC_CHILDREN 3105 REG("children", S_IRUGO, proc_tid_children_operations), 3106 #endif 3107 #ifdef CONFIG_NUMA 3108 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations), 3109 #endif 3110 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3111 LNK("cwd", proc_cwd_link), 3112 LNK("root", proc_root_link), 3113 LNK("exe", proc_exe_link), 3114 REG("mounts", S_IRUGO, proc_mounts_operations), 3115 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3116 #ifdef CONFIG_PROC_PAGE_MONITOR 3117 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3118 REG("smaps", S_IRUGO, proc_tid_smaps_operations), 3119 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3120 #endif 3121 #ifdef CONFIG_SECURITY 3122 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3123 #endif 3124 #ifdef CONFIG_KALLSYMS 3125 ONE("wchan", S_IRUGO, proc_pid_wchan), 3126 #endif 3127 #ifdef CONFIG_STACKTRACE 3128 ONE("stack", S_IRUSR, proc_pid_stack), 3129 #endif 3130 #ifdef CONFIG_SCHED_INFO 3131 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 3132 #endif 3133 #ifdef CONFIG_LATENCYTOP 3134 REG("latency", S_IRUGO, proc_lstats_operations), 3135 #endif 3136 #ifdef CONFIG_PROC_PID_CPUSET 3137 ONE("cpuset", S_IRUGO, proc_cpuset_show), 3138 #endif 3139 #ifdef CONFIG_CGROUPS 3140 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3141 #endif 3142 ONE("oom_score", S_IRUGO, proc_oom_score), 3143 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3144 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3145 #ifdef CONFIG_AUDITSYSCALL 3146 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3147 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3148 #endif 3149 #ifdef CONFIG_FAULT_INJECTION 3150 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3151 #endif 3152 #ifdef CONFIG_TASK_IO_ACCOUNTING 3153 ONE("io", S_IRUSR, proc_tid_io_accounting), 3154 #endif 3155 #ifdef CONFIG_HARDWALL 3156 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 3157 #endif 3158 #ifdef CONFIG_USER_NS 3159 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3160 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3161 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3162 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3163 #endif 3164 }; 3165 3166 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx) 3167 { 3168 return proc_pident_readdir(file, ctx, 3169 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3170 } 3171 3172 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3173 { 3174 return proc_pident_lookup(dir, dentry, 3175 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3176 } 3177 3178 static const struct file_operations proc_tid_base_operations = { 3179 .read = generic_read_dir, 3180 .iterate = proc_tid_base_readdir, 3181 .llseek = default_llseek, 3182 }; 3183 3184 static const struct inode_operations proc_tid_base_inode_operations = { 3185 .lookup = proc_tid_base_lookup, 3186 .getattr = pid_getattr, 3187 .setattr = proc_setattr, 3188 }; 3189 3190 static int proc_task_instantiate(struct inode *dir, 3191 struct dentry *dentry, struct task_struct *task, const void *ptr) 3192 { 3193 struct inode *inode; 3194 inode = proc_pid_make_inode(dir->i_sb, task); 3195 3196 if (!inode) 3197 goto out; 3198 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3199 inode->i_op = &proc_tid_base_inode_operations; 3200 inode->i_fop = &proc_tid_base_operations; 3201 inode->i_flags|=S_IMMUTABLE; 3202 3203 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff, 3204 ARRAY_SIZE(tid_base_stuff))); 3205 3206 d_set_d_op(dentry, &pid_dentry_operations); 3207 3208 d_add(dentry, inode); 3209 /* Close the race of the process dying before we return the dentry */ 3210 if (pid_revalidate(dentry, 0)) 3211 return 0; 3212 out: 3213 return -ENOENT; 3214 } 3215 3216 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3217 { 3218 int result = -ENOENT; 3219 struct task_struct *task; 3220 struct task_struct *leader = get_proc_task(dir); 3221 unsigned tid; 3222 struct pid_namespace *ns; 3223 3224 if (!leader) 3225 goto out_no_task; 3226 3227 tid = name_to_int(&dentry->d_name); 3228 if (tid == ~0U) 3229 goto out; 3230 3231 ns = dentry->d_sb->s_fs_info; 3232 rcu_read_lock(); 3233 task = find_task_by_pid_ns(tid, ns); 3234 if (task) 3235 get_task_struct(task); 3236 rcu_read_unlock(); 3237 if (!task) 3238 goto out; 3239 if (!same_thread_group(leader, task)) 3240 goto out_drop_task; 3241 3242 result = proc_task_instantiate(dir, dentry, task, NULL); 3243 out_drop_task: 3244 put_task_struct(task); 3245 out: 3246 put_task_struct(leader); 3247 out_no_task: 3248 return ERR_PTR(result); 3249 } 3250 3251 /* 3252 * Find the first tid of a thread group to return to user space. 3253 * 3254 * Usually this is just the thread group leader, but if the users 3255 * buffer was too small or there was a seek into the middle of the 3256 * directory we have more work todo. 3257 * 3258 * In the case of a short read we start with find_task_by_pid. 3259 * 3260 * In the case of a seek we start with the leader and walk nr 3261 * threads past it. 3262 */ 3263 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos, 3264 struct pid_namespace *ns) 3265 { 3266 struct task_struct *pos, *task; 3267 unsigned long nr = f_pos; 3268 3269 if (nr != f_pos) /* 32bit overflow? */ 3270 return NULL; 3271 3272 rcu_read_lock(); 3273 task = pid_task(pid, PIDTYPE_PID); 3274 if (!task) 3275 goto fail; 3276 3277 /* Attempt to start with the tid of a thread */ 3278 if (tid && nr) { 3279 pos = find_task_by_pid_ns(tid, ns); 3280 if (pos && same_thread_group(pos, task)) 3281 goto found; 3282 } 3283 3284 /* If nr exceeds the number of threads there is nothing todo */ 3285 if (nr >= get_nr_threads(task)) 3286 goto fail; 3287 3288 /* If we haven't found our starting place yet start 3289 * with the leader and walk nr threads forward. 3290 */ 3291 pos = task = task->group_leader; 3292 do { 3293 if (!nr--) 3294 goto found; 3295 } while_each_thread(task, pos); 3296 fail: 3297 pos = NULL; 3298 goto out; 3299 found: 3300 get_task_struct(pos); 3301 out: 3302 rcu_read_unlock(); 3303 return pos; 3304 } 3305 3306 /* 3307 * Find the next thread in the thread list. 3308 * Return NULL if there is an error or no next thread. 3309 * 3310 * The reference to the input task_struct is released. 3311 */ 3312 static struct task_struct *next_tid(struct task_struct *start) 3313 { 3314 struct task_struct *pos = NULL; 3315 rcu_read_lock(); 3316 if (pid_alive(start)) { 3317 pos = next_thread(start); 3318 if (thread_group_leader(pos)) 3319 pos = NULL; 3320 else 3321 get_task_struct(pos); 3322 } 3323 rcu_read_unlock(); 3324 put_task_struct(start); 3325 return pos; 3326 } 3327 3328 /* for the /proc/TGID/task/ directories */ 3329 static int proc_task_readdir(struct file *file, struct dir_context *ctx) 3330 { 3331 struct inode *inode = file_inode(file); 3332 struct task_struct *task; 3333 struct pid_namespace *ns; 3334 int tid; 3335 3336 if (proc_inode_is_dead(inode)) 3337 return -ENOENT; 3338 3339 if (!dir_emit_dots(file, ctx)) 3340 return 0; 3341 3342 /* f_version caches the tgid value that the last readdir call couldn't 3343 * return. lseek aka telldir automagically resets f_version to 0. 3344 */ 3345 ns = inode->i_sb->s_fs_info; 3346 tid = (int)file->f_version; 3347 file->f_version = 0; 3348 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); 3349 task; 3350 task = next_tid(task), ctx->pos++) { 3351 char name[PROC_NUMBUF]; 3352 int len; 3353 tid = task_pid_nr_ns(task, ns); 3354 len = snprintf(name, sizeof(name), "%d", tid); 3355 if (!proc_fill_cache(file, ctx, name, len, 3356 proc_task_instantiate, task, NULL)) { 3357 /* returning this tgid failed, save it as the first 3358 * pid for the next readir call */ 3359 file->f_version = (u64)tid; 3360 put_task_struct(task); 3361 break; 3362 } 3363 } 3364 3365 return 0; 3366 } 3367 3368 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3369 { 3370 struct inode *inode = d_inode(dentry); 3371 struct task_struct *p = get_proc_task(inode); 3372 generic_fillattr(inode, stat); 3373 3374 if (p) { 3375 stat->nlink += get_nr_threads(p); 3376 put_task_struct(p); 3377 } 3378 3379 return 0; 3380 } 3381 3382 static const struct inode_operations proc_task_inode_operations = { 3383 .lookup = proc_task_lookup, 3384 .getattr = proc_task_getattr, 3385 .setattr = proc_setattr, 3386 .permission = proc_pid_permission, 3387 }; 3388 3389 static const struct file_operations proc_task_operations = { 3390 .read = generic_read_dir, 3391 .iterate = proc_task_readdir, 3392 .llseek = default_llseek, 3393 }; 3394