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