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