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