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_puts(m, "0\n"); 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 if (!mm) 959 return 0; 960 961 page = (char *)__get_free_page(GFP_TEMPORARY); 962 if (!page) 963 return -ENOMEM; 964 965 ret = 0; 966 if (!atomic_inc_not_zero(&mm->mm_users)) 967 goto free; 968 969 down_read(&mm->mmap_sem); 970 env_start = mm->env_start; 971 env_end = mm->env_end; 972 up_read(&mm->mmap_sem); 973 974 while (count > 0) { 975 size_t this_len, max_len; 976 int retval; 977 978 if (src >= (env_end - env_start)) 979 break; 980 981 this_len = env_end - (env_start + src); 982 983 max_len = min_t(size_t, PAGE_SIZE, count); 984 this_len = min(max_len, this_len); 985 986 retval = access_remote_vm(mm, (env_start + src), 987 page, this_len, 0); 988 989 if (retval <= 0) { 990 ret = retval; 991 break; 992 } 993 994 if (copy_to_user(buf, page, retval)) { 995 ret = -EFAULT; 996 break; 997 } 998 999 ret += retval; 1000 src += retval; 1001 buf += retval; 1002 count -= retval; 1003 } 1004 *ppos = src; 1005 mmput(mm); 1006 1007 free: 1008 free_page((unsigned long) page); 1009 return ret; 1010 } 1011 1012 static const struct file_operations proc_environ_operations = { 1013 .open = environ_open, 1014 .read = environ_read, 1015 .llseek = generic_file_llseek, 1016 .release = mem_release, 1017 }; 1018 1019 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count, 1020 loff_t *ppos) 1021 { 1022 struct task_struct *task = get_proc_task(file_inode(file)); 1023 char buffer[PROC_NUMBUF]; 1024 int oom_adj = OOM_ADJUST_MIN; 1025 size_t len; 1026 unsigned long flags; 1027 1028 if (!task) 1029 return -ESRCH; 1030 if (lock_task_sighand(task, &flags)) { 1031 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX) 1032 oom_adj = OOM_ADJUST_MAX; 1033 else 1034 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) / 1035 OOM_SCORE_ADJ_MAX; 1036 unlock_task_sighand(task, &flags); 1037 } 1038 put_task_struct(task); 1039 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj); 1040 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1041 } 1042 1043 /* 1044 * /proc/pid/oom_adj exists solely for backwards compatibility with previous 1045 * kernels. The effective policy is defined by oom_score_adj, which has a 1046 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly. 1047 * Values written to oom_adj are simply mapped linearly to oom_score_adj. 1048 * Processes that become oom disabled via oom_adj will still be oom disabled 1049 * with this implementation. 1050 * 1051 * oom_adj cannot be removed since existing userspace binaries use it. 1052 */ 1053 static ssize_t oom_adj_write(struct file *file, const char __user *buf, 1054 size_t count, loff_t *ppos) 1055 { 1056 struct task_struct *task; 1057 char buffer[PROC_NUMBUF]; 1058 int oom_adj; 1059 unsigned long flags; 1060 int err; 1061 1062 memset(buffer, 0, sizeof(buffer)); 1063 if (count > sizeof(buffer) - 1) 1064 count = sizeof(buffer) - 1; 1065 if (copy_from_user(buffer, buf, count)) { 1066 err = -EFAULT; 1067 goto out; 1068 } 1069 1070 err = kstrtoint(strstrip(buffer), 0, &oom_adj); 1071 if (err) 1072 goto out; 1073 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) && 1074 oom_adj != OOM_DISABLE) { 1075 err = -EINVAL; 1076 goto out; 1077 } 1078 1079 task = get_proc_task(file_inode(file)); 1080 if (!task) { 1081 err = -ESRCH; 1082 goto out; 1083 } 1084 1085 task_lock(task); 1086 if (!task->mm) { 1087 err = -EINVAL; 1088 goto err_task_lock; 1089 } 1090 1091 if (!lock_task_sighand(task, &flags)) { 1092 err = -ESRCH; 1093 goto err_task_lock; 1094 } 1095 1096 /* 1097 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 1098 * value is always attainable. 1099 */ 1100 if (oom_adj == OOM_ADJUST_MAX) 1101 oom_adj = OOM_SCORE_ADJ_MAX; 1102 else 1103 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE; 1104 1105 if (oom_adj < task->signal->oom_score_adj && 1106 !capable(CAP_SYS_RESOURCE)) { 1107 err = -EACCES; 1108 goto err_sighand; 1109 } 1110 1111 /* 1112 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use 1113 * /proc/pid/oom_score_adj instead. 1114 */ 1115 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 1116 current->comm, task_pid_nr(current), task_pid_nr(task), 1117 task_pid_nr(task)); 1118 1119 task->signal->oom_score_adj = oom_adj; 1120 trace_oom_score_adj_update(task); 1121 err_sighand: 1122 unlock_task_sighand(task, &flags); 1123 err_task_lock: 1124 task_unlock(task); 1125 put_task_struct(task); 1126 out: 1127 return err < 0 ? err : count; 1128 } 1129 1130 static const struct file_operations proc_oom_adj_operations = { 1131 .read = oom_adj_read, 1132 .write = oom_adj_write, 1133 .llseek = generic_file_llseek, 1134 }; 1135 1136 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 1137 size_t count, loff_t *ppos) 1138 { 1139 struct task_struct *task = get_proc_task(file_inode(file)); 1140 char buffer[PROC_NUMBUF]; 1141 short oom_score_adj = OOM_SCORE_ADJ_MIN; 1142 unsigned long flags; 1143 size_t len; 1144 1145 if (!task) 1146 return -ESRCH; 1147 if (lock_task_sighand(task, &flags)) { 1148 oom_score_adj = task->signal->oom_score_adj; 1149 unlock_task_sighand(task, &flags); 1150 } 1151 put_task_struct(task); 1152 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj); 1153 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1154 } 1155 1156 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1157 size_t count, loff_t *ppos) 1158 { 1159 struct task_struct *task; 1160 char buffer[PROC_NUMBUF]; 1161 unsigned long flags; 1162 int oom_score_adj; 1163 int err; 1164 1165 memset(buffer, 0, sizeof(buffer)); 1166 if (count > sizeof(buffer) - 1) 1167 count = sizeof(buffer) - 1; 1168 if (copy_from_user(buffer, buf, count)) { 1169 err = -EFAULT; 1170 goto out; 1171 } 1172 1173 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 1174 if (err) 1175 goto out; 1176 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1177 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1178 err = -EINVAL; 1179 goto out; 1180 } 1181 1182 task = get_proc_task(file_inode(file)); 1183 if (!task) { 1184 err = -ESRCH; 1185 goto out; 1186 } 1187 1188 task_lock(task); 1189 if (!task->mm) { 1190 err = -EINVAL; 1191 goto err_task_lock; 1192 } 1193 1194 if (!lock_task_sighand(task, &flags)) { 1195 err = -ESRCH; 1196 goto err_task_lock; 1197 } 1198 1199 if ((short)oom_score_adj < task->signal->oom_score_adj_min && 1200 !capable(CAP_SYS_RESOURCE)) { 1201 err = -EACCES; 1202 goto err_sighand; 1203 } 1204 1205 task->signal->oom_score_adj = (short)oom_score_adj; 1206 if (has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1207 task->signal->oom_score_adj_min = (short)oom_score_adj; 1208 trace_oom_score_adj_update(task); 1209 1210 err_sighand: 1211 unlock_task_sighand(task, &flags); 1212 err_task_lock: 1213 task_unlock(task); 1214 put_task_struct(task); 1215 out: 1216 return err < 0 ? err : count; 1217 } 1218 1219 static const struct file_operations proc_oom_score_adj_operations = { 1220 .read = oom_score_adj_read, 1221 .write = oom_score_adj_write, 1222 .llseek = default_llseek, 1223 }; 1224 1225 #ifdef CONFIG_AUDITSYSCALL 1226 #define TMPBUFLEN 21 1227 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1228 size_t count, loff_t *ppos) 1229 { 1230 struct inode * inode = file_inode(file); 1231 struct task_struct *task = get_proc_task(inode); 1232 ssize_t length; 1233 char tmpbuf[TMPBUFLEN]; 1234 1235 if (!task) 1236 return -ESRCH; 1237 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1238 from_kuid(file->f_cred->user_ns, 1239 audit_get_loginuid(task))); 1240 put_task_struct(task); 1241 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1242 } 1243 1244 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1245 size_t count, loff_t *ppos) 1246 { 1247 struct inode * inode = file_inode(file); 1248 uid_t loginuid; 1249 kuid_t kloginuid; 1250 int rv; 1251 1252 rcu_read_lock(); 1253 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1254 rcu_read_unlock(); 1255 return -EPERM; 1256 } 1257 rcu_read_unlock(); 1258 1259 if (*ppos != 0) { 1260 /* No partial writes. */ 1261 return -EINVAL; 1262 } 1263 1264 rv = kstrtou32_from_user(buf, count, 10, &loginuid); 1265 if (rv < 0) 1266 return rv; 1267 1268 /* is userspace tring to explicitly UNSET the loginuid? */ 1269 if (loginuid == AUDIT_UID_UNSET) { 1270 kloginuid = INVALID_UID; 1271 } else { 1272 kloginuid = make_kuid(file->f_cred->user_ns, loginuid); 1273 if (!uid_valid(kloginuid)) 1274 return -EINVAL; 1275 } 1276 1277 rv = audit_set_loginuid(kloginuid); 1278 if (rv < 0) 1279 return rv; 1280 return count; 1281 } 1282 1283 static const struct file_operations proc_loginuid_operations = { 1284 .read = proc_loginuid_read, 1285 .write = proc_loginuid_write, 1286 .llseek = generic_file_llseek, 1287 }; 1288 1289 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1290 size_t count, loff_t *ppos) 1291 { 1292 struct inode * inode = file_inode(file); 1293 struct task_struct *task = get_proc_task(inode); 1294 ssize_t length; 1295 char tmpbuf[TMPBUFLEN]; 1296 1297 if (!task) 1298 return -ESRCH; 1299 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1300 audit_get_sessionid(task)); 1301 put_task_struct(task); 1302 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1303 } 1304 1305 static const struct file_operations proc_sessionid_operations = { 1306 .read = proc_sessionid_read, 1307 .llseek = generic_file_llseek, 1308 }; 1309 #endif 1310 1311 #ifdef CONFIG_FAULT_INJECTION 1312 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1313 size_t count, loff_t *ppos) 1314 { 1315 struct task_struct *task = get_proc_task(file_inode(file)); 1316 char buffer[PROC_NUMBUF]; 1317 size_t len; 1318 int make_it_fail; 1319 1320 if (!task) 1321 return -ESRCH; 1322 make_it_fail = task->make_it_fail; 1323 put_task_struct(task); 1324 1325 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1326 1327 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1328 } 1329 1330 static ssize_t proc_fault_inject_write(struct file * file, 1331 const char __user * buf, size_t count, loff_t *ppos) 1332 { 1333 struct task_struct *task; 1334 char buffer[PROC_NUMBUF]; 1335 int make_it_fail; 1336 int rv; 1337 1338 if (!capable(CAP_SYS_RESOURCE)) 1339 return -EPERM; 1340 memset(buffer, 0, sizeof(buffer)); 1341 if (count > sizeof(buffer) - 1) 1342 count = sizeof(buffer) - 1; 1343 if (copy_from_user(buffer, buf, count)) 1344 return -EFAULT; 1345 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail); 1346 if (rv < 0) 1347 return rv; 1348 if (make_it_fail < 0 || make_it_fail > 1) 1349 return -EINVAL; 1350 1351 task = get_proc_task(file_inode(file)); 1352 if (!task) 1353 return -ESRCH; 1354 task->make_it_fail = make_it_fail; 1355 put_task_struct(task); 1356 1357 return count; 1358 } 1359 1360 static const struct file_operations proc_fault_inject_operations = { 1361 .read = proc_fault_inject_read, 1362 .write = proc_fault_inject_write, 1363 .llseek = generic_file_llseek, 1364 }; 1365 #endif 1366 1367 1368 #ifdef CONFIG_SCHED_DEBUG 1369 /* 1370 * Print out various scheduling related per-task fields: 1371 */ 1372 static int sched_show(struct seq_file *m, void *v) 1373 { 1374 struct inode *inode = m->private; 1375 struct task_struct *p; 1376 1377 p = get_proc_task(inode); 1378 if (!p) 1379 return -ESRCH; 1380 proc_sched_show_task(p, m); 1381 1382 put_task_struct(p); 1383 1384 return 0; 1385 } 1386 1387 static ssize_t 1388 sched_write(struct file *file, const char __user *buf, 1389 size_t count, loff_t *offset) 1390 { 1391 struct inode *inode = file_inode(file); 1392 struct task_struct *p; 1393 1394 p = get_proc_task(inode); 1395 if (!p) 1396 return -ESRCH; 1397 proc_sched_set_task(p); 1398 1399 put_task_struct(p); 1400 1401 return count; 1402 } 1403 1404 static int sched_open(struct inode *inode, struct file *filp) 1405 { 1406 return single_open(filp, sched_show, inode); 1407 } 1408 1409 static const struct file_operations proc_pid_sched_operations = { 1410 .open = sched_open, 1411 .read = seq_read, 1412 .write = sched_write, 1413 .llseek = seq_lseek, 1414 .release = single_release, 1415 }; 1416 1417 #endif 1418 1419 #ifdef CONFIG_SCHED_AUTOGROUP 1420 /* 1421 * Print out autogroup related information: 1422 */ 1423 static int sched_autogroup_show(struct seq_file *m, void *v) 1424 { 1425 struct inode *inode = m->private; 1426 struct task_struct *p; 1427 1428 p = get_proc_task(inode); 1429 if (!p) 1430 return -ESRCH; 1431 proc_sched_autogroup_show_task(p, m); 1432 1433 put_task_struct(p); 1434 1435 return 0; 1436 } 1437 1438 static ssize_t 1439 sched_autogroup_write(struct file *file, const char __user *buf, 1440 size_t count, loff_t *offset) 1441 { 1442 struct inode *inode = file_inode(file); 1443 struct task_struct *p; 1444 char buffer[PROC_NUMBUF]; 1445 int nice; 1446 int err; 1447 1448 memset(buffer, 0, sizeof(buffer)); 1449 if (count > sizeof(buffer) - 1) 1450 count = sizeof(buffer) - 1; 1451 if (copy_from_user(buffer, buf, count)) 1452 return -EFAULT; 1453 1454 err = kstrtoint(strstrip(buffer), 0, &nice); 1455 if (err < 0) 1456 return err; 1457 1458 p = get_proc_task(inode); 1459 if (!p) 1460 return -ESRCH; 1461 1462 err = proc_sched_autogroup_set_nice(p, nice); 1463 if (err) 1464 count = err; 1465 1466 put_task_struct(p); 1467 1468 return count; 1469 } 1470 1471 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1472 { 1473 int ret; 1474 1475 ret = single_open(filp, sched_autogroup_show, NULL); 1476 if (!ret) { 1477 struct seq_file *m = filp->private_data; 1478 1479 m->private = inode; 1480 } 1481 return ret; 1482 } 1483 1484 static const struct file_operations proc_pid_sched_autogroup_operations = { 1485 .open = sched_autogroup_open, 1486 .read = seq_read, 1487 .write = sched_autogroup_write, 1488 .llseek = seq_lseek, 1489 .release = single_release, 1490 }; 1491 1492 #endif /* CONFIG_SCHED_AUTOGROUP */ 1493 1494 static ssize_t comm_write(struct file *file, const char __user *buf, 1495 size_t count, loff_t *offset) 1496 { 1497 struct inode *inode = file_inode(file); 1498 struct task_struct *p; 1499 char buffer[TASK_COMM_LEN]; 1500 const size_t maxlen = sizeof(buffer) - 1; 1501 1502 memset(buffer, 0, sizeof(buffer)); 1503 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count)) 1504 return -EFAULT; 1505 1506 p = get_proc_task(inode); 1507 if (!p) 1508 return -ESRCH; 1509 1510 if (same_thread_group(current, p)) 1511 set_task_comm(p, buffer); 1512 else 1513 count = -EINVAL; 1514 1515 put_task_struct(p); 1516 1517 return count; 1518 } 1519 1520 static int comm_show(struct seq_file *m, void *v) 1521 { 1522 struct inode *inode = m->private; 1523 struct task_struct *p; 1524 1525 p = get_proc_task(inode); 1526 if (!p) 1527 return -ESRCH; 1528 1529 task_lock(p); 1530 seq_printf(m, "%s\n", p->comm); 1531 task_unlock(p); 1532 1533 put_task_struct(p); 1534 1535 return 0; 1536 } 1537 1538 static int comm_open(struct inode *inode, struct file *filp) 1539 { 1540 return single_open(filp, comm_show, inode); 1541 } 1542 1543 static const struct file_operations proc_pid_set_comm_operations = { 1544 .open = comm_open, 1545 .read = seq_read, 1546 .write = comm_write, 1547 .llseek = seq_lseek, 1548 .release = single_release, 1549 }; 1550 1551 static int proc_exe_link(struct dentry *dentry, struct path *exe_path) 1552 { 1553 struct task_struct *task; 1554 struct mm_struct *mm; 1555 struct file *exe_file; 1556 1557 task = get_proc_task(d_inode(dentry)); 1558 if (!task) 1559 return -ENOENT; 1560 mm = get_task_mm(task); 1561 put_task_struct(task); 1562 if (!mm) 1563 return -ENOENT; 1564 exe_file = get_mm_exe_file(mm); 1565 mmput(mm); 1566 if (exe_file) { 1567 *exe_path = exe_file->f_path; 1568 path_get(&exe_file->f_path); 1569 fput(exe_file); 1570 return 0; 1571 } else 1572 return -ENOENT; 1573 } 1574 1575 static const char *proc_pid_get_link(struct dentry *dentry, 1576 struct inode *inode, 1577 struct delayed_call *done) 1578 { 1579 struct path path; 1580 int error = -EACCES; 1581 1582 if (!dentry) 1583 return ERR_PTR(-ECHILD); 1584 1585 /* Are we allowed to snoop on the tasks file descriptors? */ 1586 if (!proc_fd_access_allowed(inode)) 1587 goto out; 1588 1589 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1590 if (error) 1591 goto out; 1592 1593 nd_jump_link(&path); 1594 return NULL; 1595 out: 1596 return ERR_PTR(error); 1597 } 1598 1599 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1600 { 1601 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1602 char *pathname; 1603 int len; 1604 1605 if (!tmp) 1606 return -ENOMEM; 1607 1608 pathname = d_path(path, tmp, PAGE_SIZE); 1609 len = PTR_ERR(pathname); 1610 if (IS_ERR(pathname)) 1611 goto out; 1612 len = tmp + PAGE_SIZE - 1 - pathname; 1613 1614 if (len > buflen) 1615 len = buflen; 1616 if (copy_to_user(buffer, pathname, len)) 1617 len = -EFAULT; 1618 out: 1619 free_page((unsigned long)tmp); 1620 return len; 1621 } 1622 1623 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1624 { 1625 int error = -EACCES; 1626 struct inode *inode = d_inode(dentry); 1627 struct path path; 1628 1629 /* Are we allowed to snoop on the tasks file descriptors? */ 1630 if (!proc_fd_access_allowed(inode)) 1631 goto out; 1632 1633 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1634 if (error) 1635 goto out; 1636 1637 error = do_proc_readlink(&path, buffer, buflen); 1638 path_put(&path); 1639 out: 1640 return error; 1641 } 1642 1643 const struct inode_operations proc_pid_link_inode_operations = { 1644 .readlink = proc_pid_readlink, 1645 .get_link = proc_pid_get_link, 1646 .setattr = proc_setattr, 1647 }; 1648 1649 1650 /* building an inode */ 1651 1652 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1653 { 1654 struct inode * inode; 1655 struct proc_inode *ei; 1656 const struct cred *cred; 1657 1658 /* We need a new inode */ 1659 1660 inode = new_inode(sb); 1661 if (!inode) 1662 goto out; 1663 1664 /* Common stuff */ 1665 ei = PROC_I(inode); 1666 inode->i_ino = get_next_ino(); 1667 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1668 inode->i_op = &proc_def_inode_operations; 1669 1670 /* 1671 * grab the reference to task. 1672 */ 1673 ei->pid = get_task_pid(task, PIDTYPE_PID); 1674 if (!ei->pid) 1675 goto out_unlock; 1676 1677 if (task_dumpable(task)) { 1678 rcu_read_lock(); 1679 cred = __task_cred(task); 1680 inode->i_uid = cred->euid; 1681 inode->i_gid = cred->egid; 1682 rcu_read_unlock(); 1683 } 1684 security_task_to_inode(task, inode); 1685 1686 out: 1687 return inode; 1688 1689 out_unlock: 1690 iput(inode); 1691 return NULL; 1692 } 1693 1694 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1695 { 1696 struct inode *inode = d_inode(dentry); 1697 struct task_struct *task; 1698 const struct cred *cred; 1699 struct pid_namespace *pid = dentry->d_sb->s_fs_info; 1700 1701 generic_fillattr(inode, stat); 1702 1703 rcu_read_lock(); 1704 stat->uid = GLOBAL_ROOT_UID; 1705 stat->gid = GLOBAL_ROOT_GID; 1706 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1707 if (task) { 1708 if (!has_pid_permissions(pid, task, 2)) { 1709 rcu_read_unlock(); 1710 /* 1711 * This doesn't prevent learning whether PID exists, 1712 * it only makes getattr() consistent with readdir(). 1713 */ 1714 return -ENOENT; 1715 } 1716 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1717 task_dumpable(task)) { 1718 cred = __task_cred(task); 1719 stat->uid = cred->euid; 1720 stat->gid = cred->egid; 1721 } 1722 } 1723 rcu_read_unlock(); 1724 return 0; 1725 } 1726 1727 /* dentry stuff */ 1728 1729 /* 1730 * Exceptional case: normally we are not allowed to unhash a busy 1731 * directory. In this case, however, we can do it - no aliasing problems 1732 * due to the way we treat inodes. 1733 * 1734 * Rewrite the inode's ownerships here because the owning task may have 1735 * performed a setuid(), etc. 1736 * 1737 * Before the /proc/pid/status file was created the only way to read 1738 * the effective uid of a /process was to stat /proc/pid. Reading 1739 * /proc/pid/status is slow enough that procps and other packages 1740 * kept stating /proc/pid. To keep the rules in /proc simple I have 1741 * made this apply to all per process world readable and executable 1742 * directories. 1743 */ 1744 int pid_revalidate(struct dentry *dentry, unsigned int flags) 1745 { 1746 struct inode *inode; 1747 struct task_struct *task; 1748 const struct cred *cred; 1749 1750 if (flags & LOOKUP_RCU) 1751 return -ECHILD; 1752 1753 inode = d_inode(dentry); 1754 task = get_proc_task(inode); 1755 1756 if (task) { 1757 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1758 task_dumpable(task)) { 1759 rcu_read_lock(); 1760 cred = __task_cred(task); 1761 inode->i_uid = cred->euid; 1762 inode->i_gid = cred->egid; 1763 rcu_read_unlock(); 1764 } else { 1765 inode->i_uid = GLOBAL_ROOT_UID; 1766 inode->i_gid = GLOBAL_ROOT_GID; 1767 } 1768 inode->i_mode &= ~(S_ISUID | S_ISGID); 1769 security_task_to_inode(task, inode); 1770 put_task_struct(task); 1771 return 1; 1772 } 1773 return 0; 1774 } 1775 1776 static inline bool proc_inode_is_dead(struct inode *inode) 1777 { 1778 return !proc_pid(inode)->tasks[PIDTYPE_PID].first; 1779 } 1780 1781 int pid_delete_dentry(const struct dentry *dentry) 1782 { 1783 /* Is the task we represent dead? 1784 * If so, then don't put the dentry on the lru list, 1785 * kill it immediately. 1786 */ 1787 return proc_inode_is_dead(d_inode(dentry)); 1788 } 1789 1790 const struct dentry_operations pid_dentry_operations = 1791 { 1792 .d_revalidate = pid_revalidate, 1793 .d_delete = pid_delete_dentry, 1794 }; 1795 1796 /* Lookups */ 1797 1798 /* 1799 * Fill a directory entry. 1800 * 1801 * If possible create the dcache entry and derive our inode number and 1802 * file type from dcache entry. 1803 * 1804 * Since all of the proc inode numbers are dynamically generated, the inode 1805 * numbers do not exist until the inode is cache. This means creating the 1806 * the dcache entry in readdir is necessary to keep the inode numbers 1807 * reported by readdir in sync with the inode numbers reported 1808 * by stat. 1809 */ 1810 bool proc_fill_cache(struct file *file, struct dir_context *ctx, 1811 const char *name, int len, 1812 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1813 { 1814 struct dentry *child, *dir = file->f_path.dentry; 1815 struct qstr qname = QSTR_INIT(name, len); 1816 struct inode *inode; 1817 unsigned type; 1818 ino_t ino; 1819 1820 child = d_hash_and_lookup(dir, &qname); 1821 if (!child) { 1822 child = d_alloc(dir, &qname); 1823 if (!child) 1824 goto end_instantiate; 1825 if (instantiate(d_inode(dir), child, task, ptr) < 0) { 1826 dput(child); 1827 goto end_instantiate; 1828 } 1829 } 1830 inode = d_inode(child); 1831 ino = inode->i_ino; 1832 type = inode->i_mode >> 12; 1833 dput(child); 1834 return dir_emit(ctx, name, len, ino, type); 1835 1836 end_instantiate: 1837 return dir_emit(ctx, name, len, 1, DT_UNKNOWN); 1838 } 1839 1840 /* 1841 * dname_to_vma_addr - maps a dentry name into two unsigned longs 1842 * which represent vma start and end addresses. 1843 */ 1844 static int dname_to_vma_addr(struct dentry *dentry, 1845 unsigned long *start, unsigned long *end) 1846 { 1847 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2) 1848 return -EINVAL; 1849 1850 return 0; 1851 } 1852 1853 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags) 1854 { 1855 unsigned long vm_start, vm_end; 1856 bool exact_vma_exists = false; 1857 struct mm_struct *mm = NULL; 1858 struct task_struct *task; 1859 const struct cred *cred; 1860 struct inode *inode; 1861 int status = 0; 1862 1863 if (flags & LOOKUP_RCU) 1864 return -ECHILD; 1865 1866 inode = d_inode(dentry); 1867 task = get_proc_task(inode); 1868 if (!task) 1869 goto out_notask; 1870 1871 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); 1872 if (IS_ERR_OR_NULL(mm)) 1873 goto out; 1874 1875 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 1876 down_read(&mm->mmap_sem); 1877 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end); 1878 up_read(&mm->mmap_sem); 1879 } 1880 1881 mmput(mm); 1882 1883 if (exact_vma_exists) { 1884 if (task_dumpable(task)) { 1885 rcu_read_lock(); 1886 cred = __task_cred(task); 1887 inode->i_uid = cred->euid; 1888 inode->i_gid = cred->egid; 1889 rcu_read_unlock(); 1890 } else { 1891 inode->i_uid = GLOBAL_ROOT_UID; 1892 inode->i_gid = GLOBAL_ROOT_GID; 1893 } 1894 security_task_to_inode(task, inode); 1895 status = 1; 1896 } 1897 1898 out: 1899 put_task_struct(task); 1900 1901 out_notask: 1902 return status; 1903 } 1904 1905 static const struct dentry_operations tid_map_files_dentry_operations = { 1906 .d_revalidate = map_files_d_revalidate, 1907 .d_delete = pid_delete_dentry, 1908 }; 1909 1910 static int map_files_get_link(struct dentry *dentry, struct path *path) 1911 { 1912 unsigned long vm_start, vm_end; 1913 struct vm_area_struct *vma; 1914 struct task_struct *task; 1915 struct mm_struct *mm; 1916 int rc; 1917 1918 rc = -ENOENT; 1919 task = get_proc_task(d_inode(dentry)); 1920 if (!task) 1921 goto out; 1922 1923 mm = get_task_mm(task); 1924 put_task_struct(task); 1925 if (!mm) 1926 goto out; 1927 1928 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 1929 if (rc) 1930 goto out_mmput; 1931 1932 rc = -ENOENT; 1933 down_read(&mm->mmap_sem); 1934 vma = find_exact_vma(mm, vm_start, vm_end); 1935 if (vma && vma->vm_file) { 1936 *path = vma->vm_file->f_path; 1937 path_get(path); 1938 rc = 0; 1939 } 1940 up_read(&mm->mmap_sem); 1941 1942 out_mmput: 1943 mmput(mm); 1944 out: 1945 return rc; 1946 } 1947 1948 struct map_files_info { 1949 fmode_t mode; 1950 unsigned long len; 1951 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */ 1952 }; 1953 1954 /* 1955 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the 1956 * symlinks may be used to bypass permissions on ancestor directories in the 1957 * path to the file in question. 1958 */ 1959 static const char * 1960 proc_map_files_get_link(struct dentry *dentry, 1961 struct inode *inode, 1962 struct delayed_call *done) 1963 { 1964 if (!capable(CAP_SYS_ADMIN)) 1965 return ERR_PTR(-EPERM); 1966 1967 return proc_pid_get_link(dentry, inode, done); 1968 } 1969 1970 /* 1971 * Identical to proc_pid_link_inode_operations except for get_link() 1972 */ 1973 static const struct inode_operations proc_map_files_link_inode_operations = { 1974 .readlink = proc_pid_readlink, 1975 .get_link = proc_map_files_get_link, 1976 .setattr = proc_setattr, 1977 }; 1978 1979 static int 1980 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry, 1981 struct task_struct *task, const void *ptr) 1982 { 1983 fmode_t mode = (fmode_t)(unsigned long)ptr; 1984 struct proc_inode *ei; 1985 struct inode *inode; 1986 1987 inode = proc_pid_make_inode(dir->i_sb, task); 1988 if (!inode) 1989 return -ENOENT; 1990 1991 ei = PROC_I(inode); 1992 ei->op.proc_get_link = map_files_get_link; 1993 1994 inode->i_op = &proc_map_files_link_inode_operations; 1995 inode->i_size = 64; 1996 inode->i_mode = S_IFLNK; 1997 1998 if (mode & FMODE_READ) 1999 inode->i_mode |= S_IRUSR; 2000 if (mode & FMODE_WRITE) 2001 inode->i_mode |= S_IWUSR; 2002 2003 d_set_d_op(dentry, &tid_map_files_dentry_operations); 2004 d_add(dentry, inode); 2005 2006 return 0; 2007 } 2008 2009 static struct dentry *proc_map_files_lookup(struct inode *dir, 2010 struct dentry *dentry, unsigned int flags) 2011 { 2012 unsigned long vm_start, vm_end; 2013 struct vm_area_struct *vma; 2014 struct task_struct *task; 2015 int result; 2016 struct mm_struct *mm; 2017 2018 result = -ENOENT; 2019 task = get_proc_task(dir); 2020 if (!task) 2021 goto out; 2022 2023 result = -EACCES; 2024 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2025 goto out_put_task; 2026 2027 result = -ENOENT; 2028 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 2029 goto out_put_task; 2030 2031 mm = get_task_mm(task); 2032 if (!mm) 2033 goto out_put_task; 2034 2035 down_read(&mm->mmap_sem); 2036 vma = find_exact_vma(mm, vm_start, vm_end); 2037 if (!vma) 2038 goto out_no_vma; 2039 2040 if (vma->vm_file) 2041 result = proc_map_files_instantiate(dir, dentry, task, 2042 (void *)(unsigned long)vma->vm_file->f_mode); 2043 2044 out_no_vma: 2045 up_read(&mm->mmap_sem); 2046 mmput(mm); 2047 out_put_task: 2048 put_task_struct(task); 2049 out: 2050 return ERR_PTR(result); 2051 } 2052 2053 static const struct inode_operations proc_map_files_inode_operations = { 2054 .lookup = proc_map_files_lookup, 2055 .permission = proc_fd_permission, 2056 .setattr = proc_setattr, 2057 }; 2058 2059 static int 2060 proc_map_files_readdir(struct file *file, struct dir_context *ctx) 2061 { 2062 struct vm_area_struct *vma; 2063 struct task_struct *task; 2064 struct mm_struct *mm; 2065 unsigned long nr_files, pos, i; 2066 struct flex_array *fa = NULL; 2067 struct map_files_info info; 2068 struct map_files_info *p; 2069 int ret; 2070 2071 ret = -ENOENT; 2072 task = get_proc_task(file_inode(file)); 2073 if (!task) 2074 goto out; 2075 2076 ret = -EACCES; 2077 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2078 goto out_put_task; 2079 2080 ret = 0; 2081 if (!dir_emit_dots(file, ctx)) 2082 goto out_put_task; 2083 2084 mm = get_task_mm(task); 2085 if (!mm) 2086 goto out_put_task; 2087 down_read(&mm->mmap_sem); 2088 2089 nr_files = 0; 2090 2091 /* 2092 * We need two passes here: 2093 * 2094 * 1) Collect vmas of mapped files with mmap_sem taken 2095 * 2) Release mmap_sem and instantiate entries 2096 * 2097 * otherwise we get lockdep complained, since filldir() 2098 * routine might require mmap_sem taken in might_fault(). 2099 */ 2100 2101 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 2102 if (vma->vm_file && ++pos > ctx->pos) 2103 nr_files++; 2104 } 2105 2106 if (nr_files) { 2107 fa = flex_array_alloc(sizeof(info), nr_files, 2108 GFP_KERNEL); 2109 if (!fa || flex_array_prealloc(fa, 0, nr_files, 2110 GFP_KERNEL)) { 2111 ret = -ENOMEM; 2112 if (fa) 2113 flex_array_free(fa); 2114 up_read(&mm->mmap_sem); 2115 mmput(mm); 2116 goto out_put_task; 2117 } 2118 for (i = 0, vma = mm->mmap, pos = 2; vma; 2119 vma = vma->vm_next) { 2120 if (!vma->vm_file) 2121 continue; 2122 if (++pos <= ctx->pos) 2123 continue; 2124 2125 info.mode = vma->vm_file->f_mode; 2126 info.len = snprintf(info.name, 2127 sizeof(info.name), "%lx-%lx", 2128 vma->vm_start, vma->vm_end); 2129 if (flex_array_put(fa, i++, &info, GFP_KERNEL)) 2130 BUG(); 2131 } 2132 } 2133 up_read(&mm->mmap_sem); 2134 2135 for (i = 0; i < nr_files; i++) { 2136 p = flex_array_get(fa, i); 2137 if (!proc_fill_cache(file, ctx, 2138 p->name, p->len, 2139 proc_map_files_instantiate, 2140 task, 2141 (void *)(unsigned long)p->mode)) 2142 break; 2143 ctx->pos++; 2144 } 2145 if (fa) 2146 flex_array_free(fa); 2147 mmput(mm); 2148 2149 out_put_task: 2150 put_task_struct(task); 2151 out: 2152 return ret; 2153 } 2154 2155 static const struct file_operations proc_map_files_operations = { 2156 .read = generic_read_dir, 2157 .iterate = proc_map_files_readdir, 2158 .llseek = default_llseek, 2159 }; 2160 2161 #ifdef CONFIG_CHECKPOINT_RESTORE 2162 struct timers_private { 2163 struct pid *pid; 2164 struct task_struct *task; 2165 struct sighand_struct *sighand; 2166 struct pid_namespace *ns; 2167 unsigned long flags; 2168 }; 2169 2170 static void *timers_start(struct seq_file *m, loff_t *pos) 2171 { 2172 struct timers_private *tp = m->private; 2173 2174 tp->task = get_pid_task(tp->pid, PIDTYPE_PID); 2175 if (!tp->task) 2176 return ERR_PTR(-ESRCH); 2177 2178 tp->sighand = lock_task_sighand(tp->task, &tp->flags); 2179 if (!tp->sighand) 2180 return ERR_PTR(-ESRCH); 2181 2182 return seq_list_start(&tp->task->signal->posix_timers, *pos); 2183 } 2184 2185 static void *timers_next(struct seq_file *m, void *v, loff_t *pos) 2186 { 2187 struct timers_private *tp = m->private; 2188 return seq_list_next(v, &tp->task->signal->posix_timers, pos); 2189 } 2190 2191 static void timers_stop(struct seq_file *m, void *v) 2192 { 2193 struct timers_private *tp = m->private; 2194 2195 if (tp->sighand) { 2196 unlock_task_sighand(tp->task, &tp->flags); 2197 tp->sighand = NULL; 2198 } 2199 2200 if (tp->task) { 2201 put_task_struct(tp->task); 2202 tp->task = NULL; 2203 } 2204 } 2205 2206 static int show_timer(struct seq_file *m, void *v) 2207 { 2208 struct k_itimer *timer; 2209 struct timers_private *tp = m->private; 2210 int notify; 2211 static const char * const nstr[] = { 2212 [SIGEV_SIGNAL] = "signal", 2213 [SIGEV_NONE] = "none", 2214 [SIGEV_THREAD] = "thread", 2215 }; 2216 2217 timer = list_entry((struct list_head *)v, struct k_itimer, list); 2218 notify = timer->it_sigev_notify; 2219 2220 seq_printf(m, "ID: %d\n", timer->it_id); 2221 seq_printf(m, "signal: %d/%p\n", 2222 timer->sigq->info.si_signo, 2223 timer->sigq->info.si_value.sival_ptr); 2224 seq_printf(m, "notify: %s/%s.%d\n", 2225 nstr[notify & ~SIGEV_THREAD_ID], 2226 (notify & SIGEV_THREAD_ID) ? "tid" : "pid", 2227 pid_nr_ns(timer->it_pid, tp->ns)); 2228 seq_printf(m, "ClockID: %d\n", timer->it_clock); 2229 2230 return 0; 2231 } 2232 2233 static const struct seq_operations proc_timers_seq_ops = { 2234 .start = timers_start, 2235 .next = timers_next, 2236 .stop = timers_stop, 2237 .show = show_timer, 2238 }; 2239 2240 static int proc_timers_open(struct inode *inode, struct file *file) 2241 { 2242 struct timers_private *tp; 2243 2244 tp = __seq_open_private(file, &proc_timers_seq_ops, 2245 sizeof(struct timers_private)); 2246 if (!tp) 2247 return -ENOMEM; 2248 2249 tp->pid = proc_pid(inode); 2250 tp->ns = inode->i_sb->s_fs_info; 2251 return 0; 2252 } 2253 2254 static const struct file_operations proc_timers_operations = { 2255 .open = proc_timers_open, 2256 .read = seq_read, 2257 .llseek = seq_lseek, 2258 .release = seq_release_private, 2259 }; 2260 #endif 2261 2262 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf, 2263 size_t count, loff_t *offset) 2264 { 2265 struct inode *inode = file_inode(file); 2266 struct task_struct *p; 2267 u64 slack_ns; 2268 int err; 2269 2270 err = kstrtoull_from_user(buf, count, 10, &slack_ns); 2271 if (err < 0) 2272 return err; 2273 2274 p = get_proc_task(inode); 2275 if (!p) 2276 return -ESRCH; 2277 2278 if (ptrace_may_access(p, PTRACE_MODE_ATTACH_FSCREDS)) { 2279 task_lock(p); 2280 if (slack_ns == 0) 2281 p->timer_slack_ns = p->default_timer_slack_ns; 2282 else 2283 p->timer_slack_ns = slack_ns; 2284 task_unlock(p); 2285 } else 2286 count = -EPERM; 2287 2288 put_task_struct(p); 2289 2290 return count; 2291 } 2292 2293 static int timerslack_ns_show(struct seq_file *m, void *v) 2294 { 2295 struct inode *inode = m->private; 2296 struct task_struct *p; 2297 int err = 0; 2298 2299 p = get_proc_task(inode); 2300 if (!p) 2301 return -ESRCH; 2302 2303 if (ptrace_may_access(p, PTRACE_MODE_ATTACH_FSCREDS)) { 2304 task_lock(p); 2305 seq_printf(m, "%llu\n", p->timer_slack_ns); 2306 task_unlock(p); 2307 } else 2308 err = -EPERM; 2309 2310 put_task_struct(p); 2311 2312 return err; 2313 } 2314 2315 static int timerslack_ns_open(struct inode *inode, struct file *filp) 2316 { 2317 return single_open(filp, timerslack_ns_show, inode); 2318 } 2319 2320 static const struct file_operations proc_pid_set_timerslack_ns_operations = { 2321 .open = timerslack_ns_open, 2322 .read = seq_read, 2323 .write = timerslack_ns_write, 2324 .llseek = seq_lseek, 2325 .release = single_release, 2326 }; 2327 2328 static int proc_pident_instantiate(struct inode *dir, 2329 struct dentry *dentry, struct task_struct *task, const void *ptr) 2330 { 2331 const struct pid_entry *p = ptr; 2332 struct inode *inode; 2333 struct proc_inode *ei; 2334 2335 inode = proc_pid_make_inode(dir->i_sb, task); 2336 if (!inode) 2337 goto out; 2338 2339 ei = PROC_I(inode); 2340 inode->i_mode = p->mode; 2341 if (S_ISDIR(inode->i_mode)) 2342 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2343 if (p->iop) 2344 inode->i_op = p->iop; 2345 if (p->fop) 2346 inode->i_fop = p->fop; 2347 ei->op = p->op; 2348 d_set_d_op(dentry, &pid_dentry_operations); 2349 d_add(dentry, inode); 2350 /* Close the race of the process dying before we return the dentry */ 2351 if (pid_revalidate(dentry, 0)) 2352 return 0; 2353 out: 2354 return -ENOENT; 2355 } 2356 2357 static struct dentry *proc_pident_lookup(struct inode *dir, 2358 struct dentry *dentry, 2359 const struct pid_entry *ents, 2360 unsigned int nents) 2361 { 2362 int error; 2363 struct task_struct *task = get_proc_task(dir); 2364 const struct pid_entry *p, *last; 2365 2366 error = -ENOENT; 2367 2368 if (!task) 2369 goto out_no_task; 2370 2371 /* 2372 * Yes, it does not scale. And it should not. Don't add 2373 * new entries into /proc/<tgid>/ without very good reasons. 2374 */ 2375 last = &ents[nents - 1]; 2376 for (p = ents; p <= last; p++) { 2377 if (p->len != dentry->d_name.len) 2378 continue; 2379 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2380 break; 2381 } 2382 if (p > last) 2383 goto out; 2384 2385 error = proc_pident_instantiate(dir, dentry, task, p); 2386 out: 2387 put_task_struct(task); 2388 out_no_task: 2389 return ERR_PTR(error); 2390 } 2391 2392 static int proc_pident_readdir(struct file *file, struct dir_context *ctx, 2393 const struct pid_entry *ents, unsigned int nents) 2394 { 2395 struct task_struct *task = get_proc_task(file_inode(file)); 2396 const struct pid_entry *p; 2397 2398 if (!task) 2399 return -ENOENT; 2400 2401 if (!dir_emit_dots(file, ctx)) 2402 goto out; 2403 2404 if (ctx->pos >= nents + 2) 2405 goto out; 2406 2407 for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) { 2408 if (!proc_fill_cache(file, ctx, p->name, p->len, 2409 proc_pident_instantiate, task, p)) 2410 break; 2411 ctx->pos++; 2412 } 2413 out: 2414 put_task_struct(task); 2415 return 0; 2416 } 2417 2418 #ifdef CONFIG_SECURITY 2419 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2420 size_t count, loff_t *ppos) 2421 { 2422 struct inode * inode = file_inode(file); 2423 char *p = NULL; 2424 ssize_t length; 2425 struct task_struct *task = get_proc_task(inode); 2426 2427 if (!task) 2428 return -ESRCH; 2429 2430 length = security_getprocattr(task, 2431 (char*)file->f_path.dentry->d_name.name, 2432 &p); 2433 put_task_struct(task); 2434 if (length > 0) 2435 length = simple_read_from_buffer(buf, count, ppos, p, length); 2436 kfree(p); 2437 return length; 2438 } 2439 2440 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2441 size_t count, loff_t *ppos) 2442 { 2443 struct inode * inode = file_inode(file); 2444 void *page; 2445 ssize_t length; 2446 struct task_struct *task = get_proc_task(inode); 2447 2448 length = -ESRCH; 2449 if (!task) 2450 goto out_no_task; 2451 if (count > PAGE_SIZE) 2452 count = PAGE_SIZE; 2453 2454 /* No partial writes. */ 2455 length = -EINVAL; 2456 if (*ppos != 0) 2457 goto out; 2458 2459 page = memdup_user(buf, count); 2460 if (IS_ERR(page)) { 2461 length = PTR_ERR(page); 2462 goto out; 2463 } 2464 2465 /* Guard against adverse ptrace interaction */ 2466 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex); 2467 if (length < 0) 2468 goto out_free; 2469 2470 length = security_setprocattr(task, 2471 (char*)file->f_path.dentry->d_name.name, 2472 page, count); 2473 mutex_unlock(&task->signal->cred_guard_mutex); 2474 out_free: 2475 kfree(page); 2476 out: 2477 put_task_struct(task); 2478 out_no_task: 2479 return length; 2480 } 2481 2482 static const struct file_operations proc_pid_attr_operations = { 2483 .read = proc_pid_attr_read, 2484 .write = proc_pid_attr_write, 2485 .llseek = generic_file_llseek, 2486 }; 2487 2488 static const struct pid_entry attr_dir_stuff[] = { 2489 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2490 REG("prev", S_IRUGO, proc_pid_attr_operations), 2491 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2492 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2493 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2494 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2495 }; 2496 2497 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx) 2498 { 2499 return proc_pident_readdir(file, ctx, 2500 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2501 } 2502 2503 static const struct file_operations proc_attr_dir_operations = { 2504 .read = generic_read_dir, 2505 .iterate = proc_attr_dir_readdir, 2506 .llseek = default_llseek, 2507 }; 2508 2509 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2510 struct dentry *dentry, unsigned int flags) 2511 { 2512 return proc_pident_lookup(dir, dentry, 2513 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2514 } 2515 2516 static const struct inode_operations proc_attr_dir_inode_operations = { 2517 .lookup = proc_attr_dir_lookup, 2518 .getattr = pid_getattr, 2519 .setattr = proc_setattr, 2520 }; 2521 2522 #endif 2523 2524 #ifdef CONFIG_ELF_CORE 2525 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2526 size_t count, loff_t *ppos) 2527 { 2528 struct task_struct *task = get_proc_task(file_inode(file)); 2529 struct mm_struct *mm; 2530 char buffer[PROC_NUMBUF]; 2531 size_t len; 2532 int ret; 2533 2534 if (!task) 2535 return -ESRCH; 2536 2537 ret = 0; 2538 mm = get_task_mm(task); 2539 if (mm) { 2540 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2541 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2542 MMF_DUMP_FILTER_SHIFT)); 2543 mmput(mm); 2544 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2545 } 2546 2547 put_task_struct(task); 2548 2549 return ret; 2550 } 2551 2552 static ssize_t proc_coredump_filter_write(struct file *file, 2553 const char __user *buf, 2554 size_t count, 2555 loff_t *ppos) 2556 { 2557 struct task_struct *task; 2558 struct mm_struct *mm; 2559 unsigned int val; 2560 int ret; 2561 int i; 2562 unsigned long mask; 2563 2564 ret = kstrtouint_from_user(buf, count, 0, &val); 2565 if (ret < 0) 2566 return ret; 2567 2568 ret = -ESRCH; 2569 task = get_proc_task(file_inode(file)); 2570 if (!task) 2571 goto out_no_task; 2572 2573 mm = get_task_mm(task); 2574 if (!mm) 2575 goto out_no_mm; 2576 ret = 0; 2577 2578 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2579 if (val & mask) 2580 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2581 else 2582 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2583 } 2584 2585 mmput(mm); 2586 out_no_mm: 2587 put_task_struct(task); 2588 out_no_task: 2589 if (ret < 0) 2590 return ret; 2591 return count; 2592 } 2593 2594 static const struct file_operations proc_coredump_filter_operations = { 2595 .read = proc_coredump_filter_read, 2596 .write = proc_coredump_filter_write, 2597 .llseek = generic_file_llseek, 2598 }; 2599 #endif 2600 2601 #ifdef CONFIG_TASK_IO_ACCOUNTING 2602 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole) 2603 { 2604 struct task_io_accounting acct = task->ioac; 2605 unsigned long flags; 2606 int result; 2607 2608 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2609 if (result) 2610 return result; 2611 2612 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { 2613 result = -EACCES; 2614 goto out_unlock; 2615 } 2616 2617 if (whole && lock_task_sighand(task, &flags)) { 2618 struct task_struct *t = task; 2619 2620 task_io_accounting_add(&acct, &task->signal->ioac); 2621 while_each_thread(task, t) 2622 task_io_accounting_add(&acct, &t->ioac); 2623 2624 unlock_task_sighand(task, &flags); 2625 } 2626 seq_printf(m, 2627 "rchar: %llu\n" 2628 "wchar: %llu\n" 2629 "syscr: %llu\n" 2630 "syscw: %llu\n" 2631 "read_bytes: %llu\n" 2632 "write_bytes: %llu\n" 2633 "cancelled_write_bytes: %llu\n", 2634 (unsigned long long)acct.rchar, 2635 (unsigned long long)acct.wchar, 2636 (unsigned long long)acct.syscr, 2637 (unsigned long long)acct.syscw, 2638 (unsigned long long)acct.read_bytes, 2639 (unsigned long long)acct.write_bytes, 2640 (unsigned long long)acct.cancelled_write_bytes); 2641 result = 0; 2642 2643 out_unlock: 2644 mutex_unlock(&task->signal->cred_guard_mutex); 2645 return result; 2646 } 2647 2648 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2649 struct pid *pid, struct task_struct *task) 2650 { 2651 return do_io_accounting(task, m, 0); 2652 } 2653 2654 static int proc_tgid_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, 1); 2658 } 2659 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2660 2661 #ifdef CONFIG_USER_NS 2662 static int proc_id_map_open(struct inode *inode, struct file *file, 2663 const struct seq_operations *seq_ops) 2664 { 2665 struct user_namespace *ns = NULL; 2666 struct task_struct *task; 2667 struct seq_file *seq; 2668 int ret = -EINVAL; 2669 2670 task = get_proc_task(inode); 2671 if (task) { 2672 rcu_read_lock(); 2673 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2674 rcu_read_unlock(); 2675 put_task_struct(task); 2676 } 2677 if (!ns) 2678 goto err; 2679 2680 ret = seq_open(file, seq_ops); 2681 if (ret) 2682 goto err_put_ns; 2683 2684 seq = file->private_data; 2685 seq->private = ns; 2686 2687 return 0; 2688 err_put_ns: 2689 put_user_ns(ns); 2690 err: 2691 return ret; 2692 } 2693 2694 static int proc_id_map_release(struct inode *inode, struct file *file) 2695 { 2696 struct seq_file *seq = file->private_data; 2697 struct user_namespace *ns = seq->private; 2698 put_user_ns(ns); 2699 return seq_release(inode, file); 2700 } 2701 2702 static int proc_uid_map_open(struct inode *inode, struct file *file) 2703 { 2704 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2705 } 2706 2707 static int proc_gid_map_open(struct inode *inode, struct file *file) 2708 { 2709 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2710 } 2711 2712 static int proc_projid_map_open(struct inode *inode, struct file *file) 2713 { 2714 return proc_id_map_open(inode, file, &proc_projid_seq_operations); 2715 } 2716 2717 static const struct file_operations proc_uid_map_operations = { 2718 .open = proc_uid_map_open, 2719 .write = proc_uid_map_write, 2720 .read = seq_read, 2721 .llseek = seq_lseek, 2722 .release = proc_id_map_release, 2723 }; 2724 2725 static const struct file_operations proc_gid_map_operations = { 2726 .open = proc_gid_map_open, 2727 .write = proc_gid_map_write, 2728 .read = seq_read, 2729 .llseek = seq_lseek, 2730 .release = proc_id_map_release, 2731 }; 2732 2733 static const struct file_operations proc_projid_map_operations = { 2734 .open = proc_projid_map_open, 2735 .write = proc_projid_map_write, 2736 .read = seq_read, 2737 .llseek = seq_lseek, 2738 .release = proc_id_map_release, 2739 }; 2740 2741 static int proc_setgroups_open(struct inode *inode, struct file *file) 2742 { 2743 struct user_namespace *ns = NULL; 2744 struct task_struct *task; 2745 int ret; 2746 2747 ret = -ESRCH; 2748 task = get_proc_task(inode); 2749 if (task) { 2750 rcu_read_lock(); 2751 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2752 rcu_read_unlock(); 2753 put_task_struct(task); 2754 } 2755 if (!ns) 2756 goto err; 2757 2758 if (file->f_mode & FMODE_WRITE) { 2759 ret = -EACCES; 2760 if (!ns_capable(ns, CAP_SYS_ADMIN)) 2761 goto err_put_ns; 2762 } 2763 2764 ret = single_open(file, &proc_setgroups_show, ns); 2765 if (ret) 2766 goto err_put_ns; 2767 2768 return 0; 2769 err_put_ns: 2770 put_user_ns(ns); 2771 err: 2772 return ret; 2773 } 2774 2775 static int proc_setgroups_release(struct inode *inode, struct file *file) 2776 { 2777 struct seq_file *seq = file->private_data; 2778 struct user_namespace *ns = seq->private; 2779 int ret = single_release(inode, file); 2780 put_user_ns(ns); 2781 return ret; 2782 } 2783 2784 static const struct file_operations proc_setgroups_operations = { 2785 .open = proc_setgroups_open, 2786 .write = proc_setgroups_write, 2787 .read = seq_read, 2788 .llseek = seq_lseek, 2789 .release = proc_setgroups_release, 2790 }; 2791 #endif /* CONFIG_USER_NS */ 2792 2793 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2794 struct pid *pid, struct task_struct *task) 2795 { 2796 int err = lock_trace(task); 2797 if (!err) { 2798 seq_printf(m, "%08x\n", task->personality); 2799 unlock_trace(task); 2800 } 2801 return err; 2802 } 2803 2804 /* 2805 * Thread groups 2806 */ 2807 static const struct file_operations proc_task_operations; 2808 static const struct inode_operations proc_task_inode_operations; 2809 2810 static const struct pid_entry tgid_base_stuff[] = { 2811 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2812 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2813 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 2814 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2815 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2816 #ifdef CONFIG_NET 2817 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2818 #endif 2819 REG("environ", S_IRUSR, proc_environ_operations), 2820 ONE("auxv", S_IRUSR, proc_pid_auxv), 2821 ONE("status", S_IRUGO, proc_pid_status), 2822 ONE("personality", S_IRUSR, proc_pid_personality), 2823 ONE("limits", S_IRUGO, proc_pid_limits), 2824 #ifdef CONFIG_SCHED_DEBUG 2825 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2826 #endif 2827 #ifdef CONFIG_SCHED_AUTOGROUP 2828 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2829 #endif 2830 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2831 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2832 ONE("syscall", S_IRUSR, proc_pid_syscall), 2833 #endif 2834 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 2835 ONE("stat", S_IRUGO, proc_tgid_stat), 2836 ONE("statm", S_IRUGO, proc_pid_statm), 2837 REG("maps", S_IRUGO, proc_pid_maps_operations), 2838 #ifdef CONFIG_NUMA 2839 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 2840 #endif 2841 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2842 LNK("cwd", proc_cwd_link), 2843 LNK("root", proc_root_link), 2844 LNK("exe", proc_exe_link), 2845 REG("mounts", S_IRUGO, proc_mounts_operations), 2846 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2847 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2848 #ifdef CONFIG_PROC_PAGE_MONITOR 2849 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2850 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 2851 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2852 #endif 2853 #ifdef CONFIG_SECURITY 2854 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2855 #endif 2856 #ifdef CONFIG_KALLSYMS 2857 ONE("wchan", S_IRUGO, proc_pid_wchan), 2858 #endif 2859 #ifdef CONFIG_STACKTRACE 2860 ONE("stack", S_IRUSR, proc_pid_stack), 2861 #endif 2862 #ifdef CONFIG_SCHED_INFO 2863 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 2864 #endif 2865 #ifdef CONFIG_LATENCYTOP 2866 REG("latency", S_IRUGO, proc_lstats_operations), 2867 #endif 2868 #ifdef CONFIG_PROC_PID_CPUSET 2869 ONE("cpuset", S_IRUGO, proc_cpuset_show), 2870 #endif 2871 #ifdef CONFIG_CGROUPS 2872 ONE("cgroup", S_IRUGO, proc_cgroup_show), 2873 #endif 2874 ONE("oom_score", S_IRUGO, proc_oom_score), 2875 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 2876 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2877 #ifdef CONFIG_AUDITSYSCALL 2878 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2879 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2880 #endif 2881 #ifdef CONFIG_FAULT_INJECTION 2882 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2883 #endif 2884 #ifdef CONFIG_ELF_CORE 2885 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2886 #endif 2887 #ifdef CONFIG_TASK_IO_ACCOUNTING 2888 ONE("io", S_IRUSR, proc_tgid_io_accounting), 2889 #endif 2890 #ifdef CONFIG_HARDWALL 2891 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 2892 #endif 2893 #ifdef CONFIG_USER_NS 2894 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 2895 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 2896 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 2897 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 2898 #endif 2899 #ifdef CONFIG_CHECKPOINT_RESTORE 2900 REG("timers", S_IRUGO, proc_timers_operations), 2901 #endif 2902 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations), 2903 }; 2904 2905 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) 2906 { 2907 return proc_pident_readdir(file, ctx, 2908 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2909 } 2910 2911 static const struct file_operations proc_tgid_base_operations = { 2912 .read = generic_read_dir, 2913 .iterate = proc_tgid_base_readdir, 2914 .llseek = default_llseek, 2915 }; 2916 2917 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 2918 { 2919 return proc_pident_lookup(dir, dentry, 2920 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2921 } 2922 2923 static const struct inode_operations proc_tgid_base_inode_operations = { 2924 .lookup = proc_tgid_base_lookup, 2925 .getattr = pid_getattr, 2926 .setattr = proc_setattr, 2927 .permission = proc_pid_permission, 2928 }; 2929 2930 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2931 { 2932 struct dentry *dentry, *leader, *dir; 2933 char buf[PROC_NUMBUF]; 2934 struct qstr name; 2935 2936 name.name = buf; 2937 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2938 /* no ->d_hash() rejects on procfs */ 2939 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2940 if (dentry) { 2941 d_invalidate(dentry); 2942 dput(dentry); 2943 } 2944 2945 if (pid == tgid) 2946 return; 2947 2948 name.name = buf; 2949 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2950 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2951 if (!leader) 2952 goto out; 2953 2954 name.name = "task"; 2955 name.len = strlen(name.name); 2956 dir = d_hash_and_lookup(leader, &name); 2957 if (!dir) 2958 goto out_put_leader; 2959 2960 name.name = buf; 2961 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2962 dentry = d_hash_and_lookup(dir, &name); 2963 if (dentry) { 2964 d_invalidate(dentry); 2965 dput(dentry); 2966 } 2967 2968 dput(dir); 2969 out_put_leader: 2970 dput(leader); 2971 out: 2972 return; 2973 } 2974 2975 /** 2976 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2977 * @task: task that should be flushed. 2978 * 2979 * When flushing dentries from proc, one needs to flush them from global 2980 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2981 * in. This call is supposed to do all of this job. 2982 * 2983 * Looks in the dcache for 2984 * /proc/@pid 2985 * /proc/@tgid/task/@pid 2986 * if either directory is present flushes it and all of it'ts children 2987 * from the dcache. 2988 * 2989 * It is safe and reasonable to cache /proc entries for a task until 2990 * that task exits. After that they just clog up the dcache with 2991 * useless entries, possibly causing useful dcache entries to be 2992 * flushed instead. This routine is proved to flush those useless 2993 * dcache entries at process exit time. 2994 * 2995 * NOTE: This routine is just an optimization so it does not guarantee 2996 * that no dcache entries will exist at process exit time it 2997 * just makes it very unlikely that any will persist. 2998 */ 2999 3000 void proc_flush_task(struct task_struct *task) 3001 { 3002 int i; 3003 struct pid *pid, *tgid; 3004 struct upid *upid; 3005 3006 pid = task_pid(task); 3007 tgid = task_tgid(task); 3008 3009 for (i = 0; i <= pid->level; i++) { 3010 upid = &pid->numbers[i]; 3011 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3012 tgid->numbers[i].nr); 3013 } 3014 } 3015 3016 static int proc_pid_instantiate(struct inode *dir, 3017 struct dentry * dentry, 3018 struct task_struct *task, const void *ptr) 3019 { 3020 struct inode *inode; 3021 3022 inode = proc_pid_make_inode(dir->i_sb, task); 3023 if (!inode) 3024 goto out; 3025 3026 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3027 inode->i_op = &proc_tgid_base_inode_operations; 3028 inode->i_fop = &proc_tgid_base_operations; 3029 inode->i_flags|=S_IMMUTABLE; 3030 3031 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff, 3032 ARRAY_SIZE(tgid_base_stuff))); 3033 3034 d_set_d_op(dentry, &pid_dentry_operations); 3035 3036 d_add(dentry, inode); 3037 /* Close the race of the process dying before we return the dentry */ 3038 if (pid_revalidate(dentry, 0)) 3039 return 0; 3040 out: 3041 return -ENOENT; 3042 } 3043 3044 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3045 { 3046 int result = -ENOENT; 3047 struct task_struct *task; 3048 unsigned tgid; 3049 struct pid_namespace *ns; 3050 3051 tgid = name_to_int(&dentry->d_name); 3052 if (tgid == ~0U) 3053 goto out; 3054 3055 ns = dentry->d_sb->s_fs_info; 3056 rcu_read_lock(); 3057 task = find_task_by_pid_ns(tgid, ns); 3058 if (task) 3059 get_task_struct(task); 3060 rcu_read_unlock(); 3061 if (!task) 3062 goto out; 3063 3064 result = proc_pid_instantiate(dir, dentry, task, NULL); 3065 put_task_struct(task); 3066 out: 3067 return ERR_PTR(result); 3068 } 3069 3070 /* 3071 * Find the first task with tgid >= tgid 3072 * 3073 */ 3074 struct tgid_iter { 3075 unsigned int tgid; 3076 struct task_struct *task; 3077 }; 3078 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3079 { 3080 struct pid *pid; 3081 3082 if (iter.task) 3083 put_task_struct(iter.task); 3084 rcu_read_lock(); 3085 retry: 3086 iter.task = NULL; 3087 pid = find_ge_pid(iter.tgid, ns); 3088 if (pid) { 3089 iter.tgid = pid_nr_ns(pid, ns); 3090 iter.task = pid_task(pid, PIDTYPE_PID); 3091 /* What we to know is if the pid we have find is the 3092 * pid of a thread_group_leader. Testing for task 3093 * being a thread_group_leader is the obvious thing 3094 * todo but there is a window when it fails, due to 3095 * the pid transfer logic in de_thread. 3096 * 3097 * So we perform the straight forward test of seeing 3098 * if the pid we have found is the pid of a thread 3099 * group leader, and don't worry if the task we have 3100 * found doesn't happen to be a thread group leader. 3101 * As we don't care in the case of readdir. 3102 */ 3103 if (!iter.task || !has_group_leader_pid(iter.task)) { 3104 iter.tgid += 1; 3105 goto retry; 3106 } 3107 get_task_struct(iter.task); 3108 } 3109 rcu_read_unlock(); 3110 return iter; 3111 } 3112 3113 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2) 3114 3115 /* for the /proc/ directory itself, after non-process stuff has been done */ 3116 int proc_pid_readdir(struct file *file, struct dir_context *ctx) 3117 { 3118 struct tgid_iter iter; 3119 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info; 3120 loff_t pos = ctx->pos; 3121 3122 if (pos >= PID_MAX_LIMIT + TGID_OFFSET) 3123 return 0; 3124 3125 if (pos == TGID_OFFSET - 2) { 3126 struct inode *inode = d_inode(ns->proc_self); 3127 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) 3128 return 0; 3129 ctx->pos = pos = pos + 1; 3130 } 3131 if (pos == TGID_OFFSET - 1) { 3132 struct inode *inode = d_inode(ns->proc_thread_self); 3133 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) 3134 return 0; 3135 ctx->pos = pos = pos + 1; 3136 } 3137 iter.tgid = pos - TGID_OFFSET; 3138 iter.task = NULL; 3139 for (iter = next_tgid(ns, iter); 3140 iter.task; 3141 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3142 char name[PROC_NUMBUF]; 3143 int len; 3144 if (!has_pid_permissions(ns, iter.task, 2)) 3145 continue; 3146 3147 len = snprintf(name, sizeof(name), "%d", iter.tgid); 3148 ctx->pos = iter.tgid + TGID_OFFSET; 3149 if (!proc_fill_cache(file, ctx, name, len, 3150 proc_pid_instantiate, iter.task, NULL)) { 3151 put_task_struct(iter.task); 3152 return 0; 3153 } 3154 } 3155 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET; 3156 return 0; 3157 } 3158 3159 /* 3160 * Tasks 3161 */ 3162 static const struct pid_entry tid_base_stuff[] = { 3163 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3164 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3165 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3166 #ifdef CONFIG_NET 3167 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3168 #endif 3169 REG("environ", S_IRUSR, proc_environ_operations), 3170 ONE("auxv", S_IRUSR, proc_pid_auxv), 3171 ONE("status", S_IRUGO, proc_pid_status), 3172 ONE("personality", S_IRUSR, proc_pid_personality), 3173 ONE("limits", S_IRUGO, proc_pid_limits), 3174 #ifdef CONFIG_SCHED_DEBUG 3175 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3176 #endif 3177 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3178 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3179 ONE("syscall", S_IRUSR, proc_pid_syscall), 3180 #endif 3181 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 3182 ONE("stat", S_IRUGO, proc_tid_stat), 3183 ONE("statm", S_IRUGO, proc_pid_statm), 3184 REG("maps", S_IRUGO, proc_tid_maps_operations), 3185 #ifdef CONFIG_PROC_CHILDREN 3186 REG("children", S_IRUGO, proc_tid_children_operations), 3187 #endif 3188 #ifdef CONFIG_NUMA 3189 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations), 3190 #endif 3191 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3192 LNK("cwd", proc_cwd_link), 3193 LNK("root", proc_root_link), 3194 LNK("exe", proc_exe_link), 3195 REG("mounts", S_IRUGO, proc_mounts_operations), 3196 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3197 #ifdef CONFIG_PROC_PAGE_MONITOR 3198 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3199 REG("smaps", S_IRUGO, proc_tid_smaps_operations), 3200 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3201 #endif 3202 #ifdef CONFIG_SECURITY 3203 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3204 #endif 3205 #ifdef CONFIG_KALLSYMS 3206 ONE("wchan", S_IRUGO, proc_pid_wchan), 3207 #endif 3208 #ifdef CONFIG_STACKTRACE 3209 ONE("stack", S_IRUSR, proc_pid_stack), 3210 #endif 3211 #ifdef CONFIG_SCHED_INFO 3212 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 3213 #endif 3214 #ifdef CONFIG_LATENCYTOP 3215 REG("latency", S_IRUGO, proc_lstats_operations), 3216 #endif 3217 #ifdef CONFIG_PROC_PID_CPUSET 3218 ONE("cpuset", S_IRUGO, proc_cpuset_show), 3219 #endif 3220 #ifdef CONFIG_CGROUPS 3221 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3222 #endif 3223 ONE("oom_score", S_IRUGO, proc_oom_score), 3224 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3225 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3226 #ifdef CONFIG_AUDITSYSCALL 3227 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3228 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3229 #endif 3230 #ifdef CONFIG_FAULT_INJECTION 3231 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3232 #endif 3233 #ifdef CONFIG_TASK_IO_ACCOUNTING 3234 ONE("io", S_IRUSR, proc_tid_io_accounting), 3235 #endif 3236 #ifdef CONFIG_HARDWALL 3237 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 3238 #endif 3239 #ifdef CONFIG_USER_NS 3240 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3241 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3242 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3243 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3244 #endif 3245 }; 3246 3247 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx) 3248 { 3249 return proc_pident_readdir(file, ctx, 3250 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3251 } 3252 3253 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3254 { 3255 return proc_pident_lookup(dir, dentry, 3256 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3257 } 3258 3259 static const struct file_operations proc_tid_base_operations = { 3260 .read = generic_read_dir, 3261 .iterate = proc_tid_base_readdir, 3262 .llseek = default_llseek, 3263 }; 3264 3265 static const struct inode_operations proc_tid_base_inode_operations = { 3266 .lookup = proc_tid_base_lookup, 3267 .getattr = pid_getattr, 3268 .setattr = proc_setattr, 3269 }; 3270 3271 static int proc_task_instantiate(struct inode *dir, 3272 struct dentry *dentry, struct task_struct *task, const void *ptr) 3273 { 3274 struct inode *inode; 3275 inode = proc_pid_make_inode(dir->i_sb, task); 3276 3277 if (!inode) 3278 goto out; 3279 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3280 inode->i_op = &proc_tid_base_inode_operations; 3281 inode->i_fop = &proc_tid_base_operations; 3282 inode->i_flags|=S_IMMUTABLE; 3283 3284 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff, 3285 ARRAY_SIZE(tid_base_stuff))); 3286 3287 d_set_d_op(dentry, &pid_dentry_operations); 3288 3289 d_add(dentry, inode); 3290 /* Close the race of the process dying before we return the dentry */ 3291 if (pid_revalidate(dentry, 0)) 3292 return 0; 3293 out: 3294 return -ENOENT; 3295 } 3296 3297 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3298 { 3299 int result = -ENOENT; 3300 struct task_struct *task; 3301 struct task_struct *leader = get_proc_task(dir); 3302 unsigned tid; 3303 struct pid_namespace *ns; 3304 3305 if (!leader) 3306 goto out_no_task; 3307 3308 tid = name_to_int(&dentry->d_name); 3309 if (tid == ~0U) 3310 goto out; 3311 3312 ns = dentry->d_sb->s_fs_info; 3313 rcu_read_lock(); 3314 task = find_task_by_pid_ns(tid, ns); 3315 if (task) 3316 get_task_struct(task); 3317 rcu_read_unlock(); 3318 if (!task) 3319 goto out; 3320 if (!same_thread_group(leader, task)) 3321 goto out_drop_task; 3322 3323 result = proc_task_instantiate(dir, dentry, task, NULL); 3324 out_drop_task: 3325 put_task_struct(task); 3326 out: 3327 put_task_struct(leader); 3328 out_no_task: 3329 return ERR_PTR(result); 3330 } 3331 3332 /* 3333 * Find the first tid of a thread group to return to user space. 3334 * 3335 * Usually this is just the thread group leader, but if the users 3336 * buffer was too small or there was a seek into the middle of the 3337 * directory we have more work todo. 3338 * 3339 * In the case of a short read we start with find_task_by_pid. 3340 * 3341 * In the case of a seek we start with the leader and walk nr 3342 * threads past it. 3343 */ 3344 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos, 3345 struct pid_namespace *ns) 3346 { 3347 struct task_struct *pos, *task; 3348 unsigned long nr = f_pos; 3349 3350 if (nr != f_pos) /* 32bit overflow? */ 3351 return NULL; 3352 3353 rcu_read_lock(); 3354 task = pid_task(pid, PIDTYPE_PID); 3355 if (!task) 3356 goto fail; 3357 3358 /* Attempt to start with the tid of a thread */ 3359 if (tid && nr) { 3360 pos = find_task_by_pid_ns(tid, ns); 3361 if (pos && same_thread_group(pos, task)) 3362 goto found; 3363 } 3364 3365 /* If nr exceeds the number of threads there is nothing todo */ 3366 if (nr >= get_nr_threads(task)) 3367 goto fail; 3368 3369 /* If we haven't found our starting place yet start 3370 * with the leader and walk nr threads forward. 3371 */ 3372 pos = task = task->group_leader; 3373 do { 3374 if (!nr--) 3375 goto found; 3376 } while_each_thread(task, pos); 3377 fail: 3378 pos = NULL; 3379 goto out; 3380 found: 3381 get_task_struct(pos); 3382 out: 3383 rcu_read_unlock(); 3384 return pos; 3385 } 3386 3387 /* 3388 * Find the next thread in the thread list. 3389 * Return NULL if there is an error or no next thread. 3390 * 3391 * The reference to the input task_struct is released. 3392 */ 3393 static struct task_struct *next_tid(struct task_struct *start) 3394 { 3395 struct task_struct *pos = NULL; 3396 rcu_read_lock(); 3397 if (pid_alive(start)) { 3398 pos = next_thread(start); 3399 if (thread_group_leader(pos)) 3400 pos = NULL; 3401 else 3402 get_task_struct(pos); 3403 } 3404 rcu_read_unlock(); 3405 put_task_struct(start); 3406 return pos; 3407 } 3408 3409 /* for the /proc/TGID/task/ directories */ 3410 static int proc_task_readdir(struct file *file, struct dir_context *ctx) 3411 { 3412 struct inode *inode = file_inode(file); 3413 struct task_struct *task; 3414 struct pid_namespace *ns; 3415 int tid; 3416 3417 if (proc_inode_is_dead(inode)) 3418 return -ENOENT; 3419 3420 if (!dir_emit_dots(file, ctx)) 3421 return 0; 3422 3423 /* f_version caches the tgid value that the last readdir call couldn't 3424 * return. lseek aka telldir automagically resets f_version to 0. 3425 */ 3426 ns = inode->i_sb->s_fs_info; 3427 tid = (int)file->f_version; 3428 file->f_version = 0; 3429 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); 3430 task; 3431 task = next_tid(task), ctx->pos++) { 3432 char name[PROC_NUMBUF]; 3433 int len; 3434 tid = task_pid_nr_ns(task, ns); 3435 len = snprintf(name, sizeof(name), "%d", tid); 3436 if (!proc_fill_cache(file, ctx, name, len, 3437 proc_task_instantiate, task, NULL)) { 3438 /* returning this tgid failed, save it as the first 3439 * pid for the next readir call */ 3440 file->f_version = (u64)tid; 3441 put_task_struct(task); 3442 break; 3443 } 3444 } 3445 3446 return 0; 3447 } 3448 3449 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3450 { 3451 struct inode *inode = d_inode(dentry); 3452 struct task_struct *p = get_proc_task(inode); 3453 generic_fillattr(inode, stat); 3454 3455 if (p) { 3456 stat->nlink += get_nr_threads(p); 3457 put_task_struct(p); 3458 } 3459 3460 return 0; 3461 } 3462 3463 static const struct inode_operations proc_task_inode_operations = { 3464 .lookup = proc_task_lookup, 3465 .getattr = proc_task_getattr, 3466 .setattr = proc_setattr, 3467 .permission = proc_pid_permission, 3468 }; 3469 3470 static const struct file_operations proc_task_operations = { 3471 .read = generic_read_dir, 3472 .iterate = proc_task_readdir, 3473 .llseek = default_llseek, 3474 }; 3475