1 /* 2 * linux/fs/proc/base.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 * 6 * proc base directory handling functions 7 * 8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part. 9 * Instead of using magical inumbers to determine the kind of object 10 * we allocate and fill in-core inodes upon lookup. They don't even 11 * go into icache. We cache the reference to task_struct upon lookup too. 12 * Eventually it should become a filesystem in its own. We don't use the 13 * rest of procfs anymore. 14 * 15 * 16 * Changelog: 17 * 17-Jan-2005 18 * Allan Bezerra 19 * Bruna Moreira <bruna.moreira@indt.org.br> 20 * Edjard Mota <edjard.mota@indt.org.br> 21 * Ilias Biris <ilias.biris@indt.org.br> 22 * Mauricio Lin <mauricio.lin@indt.org.br> 23 * 24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 25 * 26 * A new process specific entry (smaps) included in /proc. It shows the 27 * size of rss for each memory area. The maps entry lacks information 28 * about physical memory size (rss) for each mapped file, i.e., 29 * rss information for executables and library files. 30 * This additional information is useful for any tools that need to know 31 * about physical memory consumption for a process specific library. 32 * 33 * Changelog: 34 * 21-Feb-2005 35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 36 * Pud inclusion in the page table walking. 37 * 38 * ChangeLog: 39 * 10-Mar-2005 40 * 10LE Instituto Nokia de Tecnologia - INdT: 41 * A better way to walks through the page table as suggested by Hugh Dickins. 42 * 43 * Simo Piiroinen <simo.piiroinen@nokia.com>: 44 * Smaps information related to shared, private, clean and dirty pages. 45 * 46 * Paul Mundt <paul.mundt@nokia.com>: 47 * Overall revision about smaps. 48 */ 49 50 #include <asm/uaccess.h> 51 52 #include <linux/errno.h> 53 #include <linux/time.h> 54 #include <linux/proc_fs.h> 55 #include <linux/stat.h> 56 #include <linux/task_io_accounting_ops.h> 57 #include <linux/init.h> 58 #include <linux/capability.h> 59 #include <linux/file.h> 60 #include <linux/fdtable.h> 61 #include <linux/string.h> 62 #include <linux/seq_file.h> 63 #include <linux/namei.h> 64 #include <linux/mnt_namespace.h> 65 #include <linux/mm.h> 66 #include <linux/swap.h> 67 #include <linux/rcupdate.h> 68 #include <linux/kallsyms.h> 69 #include <linux/stacktrace.h> 70 #include <linux/resource.h> 71 #include <linux/module.h> 72 #include <linux/mount.h> 73 #include <linux/security.h> 74 #include <linux/ptrace.h> 75 #include <linux/tracehook.h> 76 #include <linux/printk.h> 77 #include <linux/cgroup.h> 78 #include <linux/cpuset.h> 79 #include <linux/audit.h> 80 #include <linux/poll.h> 81 #include <linux/nsproxy.h> 82 #include <linux/oom.h> 83 #include <linux/elf.h> 84 #include <linux/pid_namespace.h> 85 #include <linux/user_namespace.h> 86 #include <linux/fs_struct.h> 87 #include <linux/slab.h> 88 #include <linux/flex_array.h> 89 #include <linux/posix-timers.h> 90 #ifdef CONFIG_HARDWALL 91 #include <asm/hardwall.h> 92 #endif 93 #include <trace/events/oom.h> 94 #include "internal.h" 95 #include "fd.h" 96 97 /* NOTE: 98 * Implementing inode permission operations in /proc is almost 99 * certainly an error. Permission checks need to happen during 100 * each system call not at open time. The reason is that most of 101 * what we wish to check for permissions in /proc varies at runtime. 102 * 103 * The classic example of a problem is opening file descriptors 104 * in /proc for a task before it execs a suid executable. 105 */ 106 107 struct pid_entry { 108 const char *name; 109 int len; 110 umode_t mode; 111 const struct inode_operations *iop; 112 const struct file_operations *fop; 113 union proc_op op; 114 }; 115 116 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 117 .name = (NAME), \ 118 .len = sizeof(NAME) - 1, \ 119 .mode = MODE, \ 120 .iop = IOP, \ 121 .fop = FOP, \ 122 .op = OP, \ 123 } 124 125 #define DIR(NAME, MODE, iops, fops) \ 126 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} ) 127 #define LNK(NAME, get_link) \ 128 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 129 &proc_pid_link_inode_operations, NULL, \ 130 { .proc_get_link = get_link } ) 131 #define REG(NAME, MODE, fops) \ 132 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {}) 133 #define ONE(NAME, MODE, show) \ 134 NOD(NAME, (S_IFREG|(MODE)), \ 135 NULL, &proc_single_file_operations, \ 136 { .proc_show = show } ) 137 138 /* 139 * Count the number of hardlinks for the pid_entry table, excluding the . 140 * and .. links. 141 */ 142 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries, 143 unsigned int n) 144 { 145 unsigned int i; 146 unsigned int count; 147 148 count = 0; 149 for (i = 0; i < n; ++i) { 150 if (S_ISDIR(entries[i].mode)) 151 ++count; 152 } 153 154 return count; 155 } 156 157 static int get_task_root(struct task_struct *task, struct path *root) 158 { 159 int result = -ENOENT; 160 161 task_lock(task); 162 if (task->fs) { 163 get_fs_root(task->fs, root); 164 result = 0; 165 } 166 task_unlock(task); 167 return result; 168 } 169 170 static int proc_cwd_link(struct dentry *dentry, struct path *path) 171 { 172 struct task_struct *task = get_proc_task(d_inode(dentry)); 173 int result = -ENOENT; 174 175 if (task) { 176 task_lock(task); 177 if (task->fs) { 178 get_fs_pwd(task->fs, path); 179 result = 0; 180 } 181 task_unlock(task); 182 put_task_struct(task); 183 } 184 return result; 185 } 186 187 static int proc_root_link(struct dentry *dentry, struct path *path) 188 { 189 struct task_struct *task = get_proc_task(d_inode(dentry)); 190 int result = -ENOENT; 191 192 if (task) { 193 result = get_task_root(task, path); 194 put_task_struct(task); 195 } 196 return result; 197 } 198 199 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, 200 size_t _count, loff_t *pos) 201 { 202 struct task_struct *tsk; 203 struct mm_struct *mm; 204 char *page; 205 unsigned long count = _count; 206 unsigned long arg_start, arg_end, env_start, env_end; 207 unsigned long len1, len2, len; 208 unsigned long p; 209 char c; 210 ssize_t rv; 211 212 BUG_ON(*pos < 0); 213 214 tsk = get_proc_task(file_inode(file)); 215 if (!tsk) 216 return -ESRCH; 217 mm = get_task_mm(tsk); 218 put_task_struct(tsk); 219 if (!mm) 220 return 0; 221 /* Check if process spawned far enough to have cmdline. */ 222 if (!mm->env_end) { 223 rv = 0; 224 goto out_mmput; 225 } 226 227 page = (char *)__get_free_page(GFP_TEMPORARY); 228 if (!page) { 229 rv = -ENOMEM; 230 goto out_mmput; 231 } 232 233 down_read(&mm->mmap_sem); 234 arg_start = mm->arg_start; 235 arg_end = mm->arg_end; 236 env_start = mm->env_start; 237 env_end = mm->env_end; 238 up_read(&mm->mmap_sem); 239 240 BUG_ON(arg_start > arg_end); 241 BUG_ON(env_start > env_end); 242 243 len1 = arg_end - arg_start; 244 len2 = env_end - env_start; 245 246 /* Empty ARGV. */ 247 if (len1 == 0) { 248 rv = 0; 249 goto out_free_page; 250 } 251 /* 252 * Inherently racy -- command line shares address space 253 * with code and data. 254 */ 255 rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0); 256 if (rv <= 0) 257 goto out_free_page; 258 259 rv = 0; 260 261 if (c == '\0') { 262 /* Command line (set of strings) occupies whole ARGV. */ 263 if (len1 <= *pos) 264 goto out_free_page; 265 266 p = arg_start + *pos; 267 len = len1 - *pos; 268 while (count > 0 && len > 0) { 269 unsigned int _count; 270 int nr_read; 271 272 _count = min3(count, len, PAGE_SIZE); 273 nr_read = access_remote_vm(mm, p, page, _count, 0); 274 if (nr_read < 0) 275 rv = nr_read; 276 if (nr_read <= 0) 277 goto out_free_page; 278 279 if (copy_to_user(buf, page, nr_read)) { 280 rv = -EFAULT; 281 goto out_free_page; 282 } 283 284 p += nr_read; 285 len -= nr_read; 286 buf += nr_read; 287 count -= nr_read; 288 rv += nr_read; 289 } 290 } else { 291 /* 292 * Command line (1 string) occupies ARGV and maybe 293 * extends into ENVP. 294 */ 295 if (len1 + len2 <= *pos) 296 goto skip_argv_envp; 297 if (len1 <= *pos) 298 goto skip_argv; 299 300 p = arg_start + *pos; 301 len = len1 - *pos; 302 while (count > 0 && len > 0) { 303 unsigned int _count, l; 304 int nr_read; 305 bool final; 306 307 _count = min3(count, len, PAGE_SIZE); 308 nr_read = access_remote_vm(mm, p, page, _count, 0); 309 if (nr_read < 0) 310 rv = nr_read; 311 if (nr_read <= 0) 312 goto out_free_page; 313 314 /* 315 * Command line can be shorter than whole ARGV 316 * even if last "marker" byte says it is not. 317 */ 318 final = false; 319 l = strnlen(page, nr_read); 320 if (l < nr_read) { 321 nr_read = l; 322 final = true; 323 } 324 325 if (copy_to_user(buf, page, nr_read)) { 326 rv = -EFAULT; 327 goto out_free_page; 328 } 329 330 p += nr_read; 331 len -= nr_read; 332 buf += nr_read; 333 count -= nr_read; 334 rv += nr_read; 335 336 if (final) 337 goto out_free_page; 338 } 339 skip_argv: 340 /* 341 * Command line (1 string) occupies ARGV and 342 * extends into ENVP. 343 */ 344 if (len1 <= *pos) { 345 p = env_start + *pos - len1; 346 len = len1 + len2 - *pos; 347 } else { 348 p = env_start; 349 len = len2; 350 } 351 while (count > 0 && len > 0) { 352 unsigned int _count, l; 353 int nr_read; 354 bool final; 355 356 _count = min3(count, len, PAGE_SIZE); 357 nr_read = access_remote_vm(mm, p, page, _count, 0); 358 if (nr_read < 0) 359 rv = nr_read; 360 if (nr_read <= 0) 361 goto out_free_page; 362 363 /* Find EOS. */ 364 final = false; 365 l = strnlen(page, nr_read); 366 if (l < nr_read) { 367 nr_read = l; 368 final = true; 369 } 370 371 if (copy_to_user(buf, page, nr_read)) { 372 rv = -EFAULT; 373 goto out_free_page; 374 } 375 376 p += nr_read; 377 len -= nr_read; 378 buf += nr_read; 379 count -= nr_read; 380 rv += nr_read; 381 382 if (final) 383 goto out_free_page; 384 } 385 skip_argv_envp: 386 ; 387 } 388 389 out_free_page: 390 free_page((unsigned long)page); 391 out_mmput: 392 mmput(mm); 393 if (rv > 0) 394 *pos += rv; 395 return rv; 396 } 397 398 static const struct file_operations proc_pid_cmdline_ops = { 399 .read = proc_pid_cmdline_read, 400 .llseek = generic_file_llseek, 401 }; 402 403 static int proc_pid_auxv(struct seq_file *m, struct pid_namespace *ns, 404 struct pid *pid, struct task_struct *task) 405 { 406 struct mm_struct *mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); 407 if (mm && !IS_ERR(mm)) { 408 unsigned int nwords = 0; 409 do { 410 nwords += 2; 411 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 412 seq_write(m, mm->saved_auxv, nwords * sizeof(mm->saved_auxv[0])); 413 mmput(mm); 414 return 0; 415 } else 416 return PTR_ERR(mm); 417 } 418 419 420 #ifdef CONFIG_KALLSYMS 421 /* 422 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 423 * Returns the resolved symbol. If that fails, simply return the address. 424 */ 425 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns, 426 struct pid *pid, struct task_struct *task) 427 { 428 unsigned long wchan; 429 char symname[KSYM_NAME_LEN]; 430 431 wchan = get_wchan(task); 432 433 if (wchan && ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS) 434 && !lookup_symbol_name(wchan, symname)) 435 seq_printf(m, "%s", symname); 436 else 437 seq_putc(m, '0'); 438 439 return 0; 440 } 441 #endif /* CONFIG_KALLSYMS */ 442 443 static int lock_trace(struct task_struct *task) 444 { 445 int err = mutex_lock_killable(&task->signal->cred_guard_mutex); 446 if (err) 447 return err; 448 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) { 449 mutex_unlock(&task->signal->cred_guard_mutex); 450 return -EPERM; 451 } 452 return 0; 453 } 454 455 static void unlock_trace(struct task_struct *task) 456 { 457 mutex_unlock(&task->signal->cred_guard_mutex); 458 } 459 460 #ifdef CONFIG_STACKTRACE 461 462 #define MAX_STACK_TRACE_DEPTH 64 463 464 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, 465 struct pid *pid, struct task_struct *task) 466 { 467 struct stack_trace trace; 468 unsigned long *entries; 469 int err; 470 int i; 471 472 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL); 473 if (!entries) 474 return -ENOMEM; 475 476 trace.nr_entries = 0; 477 trace.max_entries = MAX_STACK_TRACE_DEPTH; 478 trace.entries = entries; 479 trace.skip = 0; 480 481 err = lock_trace(task); 482 if (!err) { 483 save_stack_trace_tsk(task, &trace); 484 485 for (i = 0; i < trace.nr_entries; i++) { 486 seq_printf(m, "[<%pK>] %pS\n", 487 (void *)entries[i], (void *)entries[i]); 488 } 489 unlock_trace(task); 490 } 491 kfree(entries); 492 493 return err; 494 } 495 #endif 496 497 #ifdef CONFIG_SCHED_INFO 498 /* 499 * Provides /proc/PID/schedstat 500 */ 501 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, 502 struct pid *pid, struct task_struct *task) 503 { 504 if (unlikely(!sched_info_on())) 505 seq_printf(m, "0 0 0\n"); 506 else 507 seq_printf(m, "%llu %llu %lu\n", 508 (unsigned long long)task->se.sum_exec_runtime, 509 (unsigned long long)task->sched_info.run_delay, 510 task->sched_info.pcount); 511 512 return 0; 513 } 514 #endif 515 516 #ifdef CONFIG_LATENCYTOP 517 static int lstats_show_proc(struct seq_file *m, void *v) 518 { 519 int i; 520 struct inode *inode = m->private; 521 struct task_struct *task = get_proc_task(inode); 522 523 if (!task) 524 return -ESRCH; 525 seq_puts(m, "Latency Top version : v0.1\n"); 526 for (i = 0; i < 32; i++) { 527 struct latency_record *lr = &task->latency_record[i]; 528 if (lr->backtrace[0]) { 529 int q; 530 seq_printf(m, "%i %li %li", 531 lr->count, lr->time, lr->max); 532 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 533 unsigned long bt = lr->backtrace[q]; 534 if (!bt) 535 break; 536 if (bt == ULONG_MAX) 537 break; 538 seq_printf(m, " %ps", (void *)bt); 539 } 540 seq_putc(m, '\n'); 541 } 542 543 } 544 put_task_struct(task); 545 return 0; 546 } 547 548 static int lstats_open(struct inode *inode, struct file *file) 549 { 550 return single_open(file, lstats_show_proc, inode); 551 } 552 553 static ssize_t lstats_write(struct file *file, const char __user *buf, 554 size_t count, loff_t *offs) 555 { 556 struct task_struct *task = get_proc_task(file_inode(file)); 557 558 if (!task) 559 return -ESRCH; 560 clear_all_latency_tracing(task); 561 put_task_struct(task); 562 563 return count; 564 } 565 566 static const struct file_operations proc_lstats_operations = { 567 .open = lstats_open, 568 .read = seq_read, 569 .write = lstats_write, 570 .llseek = seq_lseek, 571 .release = single_release, 572 }; 573 574 #endif 575 576 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns, 577 struct pid *pid, struct task_struct *task) 578 { 579 unsigned long totalpages = totalram_pages + total_swap_pages; 580 unsigned long points = 0; 581 582 points = oom_badness(task, NULL, NULL, totalpages) * 583 1000 / totalpages; 584 seq_printf(m, "%lu\n", points); 585 586 return 0; 587 } 588 589 struct limit_names { 590 const char *name; 591 const char *unit; 592 }; 593 594 static const struct limit_names lnames[RLIM_NLIMITS] = { 595 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 596 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 597 [RLIMIT_DATA] = {"Max data size", "bytes"}, 598 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 599 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 600 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 601 [RLIMIT_NPROC] = {"Max processes", "processes"}, 602 [RLIMIT_NOFILE] = {"Max open files", "files"}, 603 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 604 [RLIMIT_AS] = {"Max address space", "bytes"}, 605 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 606 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 607 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 608 [RLIMIT_NICE] = {"Max nice priority", NULL}, 609 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 610 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 611 }; 612 613 /* Display limits for a process */ 614 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns, 615 struct pid *pid, struct task_struct *task) 616 { 617 unsigned int i; 618 unsigned long flags; 619 620 struct rlimit rlim[RLIM_NLIMITS]; 621 622 if (!lock_task_sighand(task, &flags)) 623 return 0; 624 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 625 unlock_task_sighand(task, &flags); 626 627 /* 628 * print the file header 629 */ 630 seq_printf(m, "%-25s %-20s %-20s %-10s\n", 631 "Limit", "Soft Limit", "Hard Limit", "Units"); 632 633 for (i = 0; i < RLIM_NLIMITS; i++) { 634 if (rlim[i].rlim_cur == RLIM_INFINITY) 635 seq_printf(m, "%-25s %-20s ", 636 lnames[i].name, "unlimited"); 637 else 638 seq_printf(m, "%-25s %-20lu ", 639 lnames[i].name, rlim[i].rlim_cur); 640 641 if (rlim[i].rlim_max == RLIM_INFINITY) 642 seq_printf(m, "%-20s ", "unlimited"); 643 else 644 seq_printf(m, "%-20lu ", rlim[i].rlim_max); 645 646 if (lnames[i].unit) 647 seq_printf(m, "%-10s\n", lnames[i].unit); 648 else 649 seq_putc(m, '\n'); 650 } 651 652 return 0; 653 } 654 655 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 656 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns, 657 struct pid *pid, struct task_struct *task) 658 { 659 long nr; 660 unsigned long args[6], sp, pc; 661 int res; 662 663 res = lock_trace(task); 664 if (res) 665 return res; 666 667 if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) 668 seq_puts(m, "running\n"); 669 else if (nr < 0) 670 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc); 671 else 672 seq_printf(m, 673 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", 674 nr, 675 args[0], args[1], args[2], args[3], args[4], args[5], 676 sp, pc); 677 unlock_trace(task); 678 679 return 0; 680 } 681 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 682 683 /************************************************************************/ 684 /* Here the fs part begins */ 685 /************************************************************************/ 686 687 /* permission checks */ 688 static int proc_fd_access_allowed(struct inode *inode) 689 { 690 struct task_struct *task; 691 int allowed = 0; 692 /* Allow access to a task's file descriptors if it is us or we 693 * may use ptrace attach to the process and find out that 694 * information. 695 */ 696 task = get_proc_task(inode); 697 if (task) { 698 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 699 put_task_struct(task); 700 } 701 return allowed; 702 } 703 704 int proc_setattr(struct dentry *dentry, struct iattr *attr) 705 { 706 int error; 707 struct inode *inode = d_inode(dentry); 708 709 if (attr->ia_valid & ATTR_MODE) 710 return -EPERM; 711 712 error = inode_change_ok(inode, attr); 713 if (error) 714 return error; 715 716 setattr_copy(inode, attr); 717 mark_inode_dirty(inode); 718 return 0; 719 } 720 721 /* 722 * May current process learn task's sched/cmdline info (for hide_pid_min=1) 723 * or euid/egid (for hide_pid_min=2)? 724 */ 725 static bool has_pid_permissions(struct pid_namespace *pid, 726 struct task_struct *task, 727 int hide_pid_min) 728 { 729 if (pid->hide_pid < hide_pid_min) 730 return true; 731 if (in_group_p(pid->pid_gid)) 732 return true; 733 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 734 } 735 736 737 static int proc_pid_permission(struct inode *inode, int mask) 738 { 739 struct pid_namespace *pid = inode->i_sb->s_fs_info; 740 struct task_struct *task; 741 bool has_perms; 742 743 task = get_proc_task(inode); 744 if (!task) 745 return -ESRCH; 746 has_perms = has_pid_permissions(pid, task, 1); 747 put_task_struct(task); 748 749 if (!has_perms) { 750 if (pid->hide_pid == 2) { 751 /* 752 * Let's make getdents(), stat(), and open() 753 * consistent with each other. If a process 754 * may not stat() a file, it shouldn't be seen 755 * in procfs at all. 756 */ 757 return -ENOENT; 758 } 759 760 return -EPERM; 761 } 762 return generic_permission(inode, mask); 763 } 764 765 766 767 static const struct inode_operations proc_def_inode_operations = { 768 .setattr = proc_setattr, 769 }; 770 771 static int proc_single_show(struct seq_file *m, void *v) 772 { 773 struct inode *inode = m->private; 774 struct pid_namespace *ns; 775 struct pid *pid; 776 struct task_struct *task; 777 int ret; 778 779 ns = inode->i_sb->s_fs_info; 780 pid = proc_pid(inode); 781 task = get_pid_task(pid, PIDTYPE_PID); 782 if (!task) 783 return -ESRCH; 784 785 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 786 787 put_task_struct(task); 788 return ret; 789 } 790 791 static int proc_single_open(struct inode *inode, struct file *filp) 792 { 793 return single_open(filp, proc_single_show, inode); 794 } 795 796 static const struct file_operations proc_single_file_operations = { 797 .open = proc_single_open, 798 .read = seq_read, 799 .llseek = seq_lseek, 800 .release = single_release, 801 }; 802 803 804 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode) 805 { 806 struct task_struct *task = get_proc_task(inode); 807 struct mm_struct *mm = ERR_PTR(-ESRCH); 808 809 if (task) { 810 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS); 811 put_task_struct(task); 812 813 if (!IS_ERR_OR_NULL(mm)) { 814 /* ensure this mm_struct can't be freed */ 815 atomic_inc(&mm->mm_count); 816 /* but do not pin its memory */ 817 mmput(mm); 818 } 819 } 820 821 return mm; 822 } 823 824 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) 825 { 826 struct mm_struct *mm = proc_mem_open(inode, mode); 827 828 if (IS_ERR(mm)) 829 return PTR_ERR(mm); 830 831 file->private_data = mm; 832 return 0; 833 } 834 835 static int mem_open(struct inode *inode, struct file *file) 836 { 837 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH); 838 839 /* OK to pass negative loff_t, we can catch out-of-range */ 840 file->f_mode |= FMODE_UNSIGNED_OFFSET; 841 842 return ret; 843 } 844 845 static ssize_t mem_rw(struct file *file, char __user *buf, 846 size_t count, loff_t *ppos, int write) 847 { 848 struct mm_struct *mm = file->private_data; 849 unsigned long addr = *ppos; 850 ssize_t copied; 851 char *page; 852 853 if (!mm) 854 return 0; 855 856 page = (char *)__get_free_page(GFP_TEMPORARY); 857 if (!page) 858 return -ENOMEM; 859 860 copied = 0; 861 if (!atomic_inc_not_zero(&mm->mm_users)) 862 goto free; 863 864 while (count > 0) { 865 int this_len = min_t(int, count, PAGE_SIZE); 866 867 if (write && copy_from_user(page, buf, this_len)) { 868 copied = -EFAULT; 869 break; 870 } 871 872 this_len = access_remote_vm(mm, addr, page, this_len, write); 873 if (!this_len) { 874 if (!copied) 875 copied = -EIO; 876 break; 877 } 878 879 if (!write && copy_to_user(buf, page, this_len)) { 880 copied = -EFAULT; 881 break; 882 } 883 884 buf += this_len; 885 addr += this_len; 886 copied += this_len; 887 count -= this_len; 888 } 889 *ppos = addr; 890 891 mmput(mm); 892 free: 893 free_page((unsigned long) page); 894 return copied; 895 } 896 897 static ssize_t mem_read(struct file *file, char __user *buf, 898 size_t count, loff_t *ppos) 899 { 900 return mem_rw(file, buf, count, ppos, 0); 901 } 902 903 static ssize_t mem_write(struct file *file, const char __user *buf, 904 size_t count, loff_t *ppos) 905 { 906 return mem_rw(file, (char __user*)buf, count, ppos, 1); 907 } 908 909 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 910 { 911 switch (orig) { 912 case 0: 913 file->f_pos = offset; 914 break; 915 case 1: 916 file->f_pos += offset; 917 break; 918 default: 919 return -EINVAL; 920 } 921 force_successful_syscall_return(); 922 return file->f_pos; 923 } 924 925 static int mem_release(struct inode *inode, struct file *file) 926 { 927 struct mm_struct *mm = file->private_data; 928 if (mm) 929 mmdrop(mm); 930 return 0; 931 } 932 933 static const struct file_operations proc_mem_operations = { 934 .llseek = mem_lseek, 935 .read = mem_read, 936 .write = mem_write, 937 .open = mem_open, 938 .release = mem_release, 939 }; 940 941 static int environ_open(struct inode *inode, struct file *file) 942 { 943 return __mem_open(inode, file, PTRACE_MODE_READ); 944 } 945 946 static ssize_t environ_read(struct file *file, char __user *buf, 947 size_t count, loff_t *ppos) 948 { 949 char *page; 950 unsigned long src = *ppos; 951 int ret = 0; 952 struct mm_struct *mm = file->private_data; 953 unsigned long env_start, env_end; 954 955 /* Ensure the process spawned far enough to have an environment. */ 956 if (!mm || !mm->env_end) 957 return 0; 958 959 page = (char *)__get_free_page(GFP_TEMPORARY); 960 if (!page) 961 return -ENOMEM; 962 963 ret = 0; 964 if (!atomic_inc_not_zero(&mm->mm_users)) 965 goto free; 966 967 down_read(&mm->mmap_sem); 968 env_start = mm->env_start; 969 env_end = mm->env_end; 970 up_read(&mm->mmap_sem); 971 972 while (count > 0) { 973 size_t this_len, max_len; 974 int retval; 975 976 if (src >= (env_end - env_start)) 977 break; 978 979 this_len = env_end - (env_start + src); 980 981 max_len = min_t(size_t, PAGE_SIZE, count); 982 this_len = min(max_len, this_len); 983 984 retval = access_remote_vm(mm, (env_start + src), 985 page, this_len, 0); 986 987 if (retval <= 0) { 988 ret = retval; 989 break; 990 } 991 992 if (copy_to_user(buf, page, retval)) { 993 ret = -EFAULT; 994 break; 995 } 996 997 ret += retval; 998 src += retval; 999 buf += retval; 1000 count -= retval; 1001 } 1002 *ppos = src; 1003 mmput(mm); 1004 1005 free: 1006 free_page((unsigned long) page); 1007 return ret; 1008 } 1009 1010 static const struct file_operations proc_environ_operations = { 1011 .open = environ_open, 1012 .read = environ_read, 1013 .llseek = generic_file_llseek, 1014 .release = mem_release, 1015 }; 1016 1017 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count, 1018 loff_t *ppos) 1019 { 1020 struct task_struct *task = get_proc_task(file_inode(file)); 1021 char buffer[PROC_NUMBUF]; 1022 int oom_adj = OOM_ADJUST_MIN; 1023 size_t len; 1024 1025 if (!task) 1026 return -ESRCH; 1027 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX) 1028 oom_adj = OOM_ADJUST_MAX; 1029 else 1030 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) / 1031 OOM_SCORE_ADJ_MAX; 1032 put_task_struct(task); 1033 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj); 1034 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1035 } 1036 1037 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy) 1038 { 1039 static DEFINE_MUTEX(oom_adj_mutex); 1040 struct mm_struct *mm = NULL; 1041 struct task_struct *task; 1042 int err = 0; 1043 1044 task = get_proc_task(file_inode(file)); 1045 if (!task) 1046 return -ESRCH; 1047 1048 mutex_lock(&oom_adj_mutex); 1049 if (legacy) { 1050 if (oom_adj < task->signal->oom_score_adj && 1051 !capable(CAP_SYS_RESOURCE)) { 1052 err = -EACCES; 1053 goto err_unlock; 1054 } 1055 /* 1056 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use 1057 * /proc/pid/oom_score_adj instead. 1058 */ 1059 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 1060 current->comm, task_pid_nr(current), task_pid_nr(task), 1061 task_pid_nr(task)); 1062 } else { 1063 if ((short)oom_adj < task->signal->oom_score_adj_min && 1064 !capable(CAP_SYS_RESOURCE)) { 1065 err = -EACCES; 1066 goto err_unlock; 1067 } 1068 } 1069 1070 /* 1071 * Make sure we will check other processes sharing the mm if this is 1072 * not vfrok which wants its own oom_score_adj. 1073 * pin the mm so it doesn't go away and get reused after task_unlock 1074 */ 1075 if (!task->vfork_done) { 1076 struct task_struct *p = find_lock_task_mm(task); 1077 1078 if (p) { 1079 if (atomic_read(&p->mm->mm_users) > 1) { 1080 mm = p->mm; 1081 atomic_inc(&mm->mm_count); 1082 } 1083 task_unlock(p); 1084 } 1085 } 1086 1087 task->signal->oom_score_adj = oom_adj; 1088 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1089 task->signal->oom_score_adj_min = (short)oom_adj; 1090 trace_oom_score_adj_update(task); 1091 1092 if (mm) { 1093 struct task_struct *p; 1094 1095 rcu_read_lock(); 1096 for_each_process(p) { 1097 if (same_thread_group(task, p)) 1098 continue; 1099 1100 /* do not touch kernel threads or the global init */ 1101 if (p->flags & PF_KTHREAD || is_global_init(p)) 1102 continue; 1103 1104 task_lock(p); 1105 if (!p->vfork_done && process_shares_mm(p, mm)) { 1106 pr_info("updating oom_score_adj for %d (%s) from %d to %d because it shares mm with %d (%s). Report if this is unexpected.\n", 1107 task_pid_nr(p), p->comm, 1108 p->signal->oom_score_adj, oom_adj, 1109 task_pid_nr(task), task->comm); 1110 p->signal->oom_score_adj = oom_adj; 1111 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1112 p->signal->oom_score_adj_min = (short)oom_adj; 1113 } 1114 task_unlock(p); 1115 } 1116 rcu_read_unlock(); 1117 mmdrop(mm); 1118 } 1119 err_unlock: 1120 mutex_unlock(&oom_adj_mutex); 1121 put_task_struct(task); 1122 return err; 1123 } 1124 1125 /* 1126 * /proc/pid/oom_adj exists solely for backwards compatibility with previous 1127 * kernels. The effective policy is defined by oom_score_adj, which has a 1128 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly. 1129 * Values written to oom_adj are simply mapped linearly to oom_score_adj. 1130 * Processes that become oom disabled via oom_adj will still be oom disabled 1131 * with this implementation. 1132 * 1133 * oom_adj cannot be removed since existing userspace binaries use it. 1134 */ 1135 static ssize_t oom_adj_write(struct file *file, const char __user *buf, 1136 size_t count, loff_t *ppos) 1137 { 1138 char buffer[PROC_NUMBUF]; 1139 int oom_adj; 1140 int err; 1141 1142 memset(buffer, 0, sizeof(buffer)); 1143 if (count > sizeof(buffer) - 1) 1144 count = sizeof(buffer) - 1; 1145 if (copy_from_user(buffer, buf, count)) { 1146 err = -EFAULT; 1147 goto out; 1148 } 1149 1150 err = kstrtoint(strstrip(buffer), 0, &oom_adj); 1151 if (err) 1152 goto out; 1153 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) && 1154 oom_adj != OOM_DISABLE) { 1155 err = -EINVAL; 1156 goto out; 1157 } 1158 1159 /* 1160 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 1161 * value is always attainable. 1162 */ 1163 if (oom_adj == OOM_ADJUST_MAX) 1164 oom_adj = OOM_SCORE_ADJ_MAX; 1165 else 1166 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE; 1167 1168 err = __set_oom_adj(file, oom_adj, true); 1169 out: 1170 return err < 0 ? err : count; 1171 } 1172 1173 static const struct file_operations proc_oom_adj_operations = { 1174 .read = oom_adj_read, 1175 .write = oom_adj_write, 1176 .llseek = generic_file_llseek, 1177 }; 1178 1179 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 1180 size_t count, loff_t *ppos) 1181 { 1182 struct task_struct *task = get_proc_task(file_inode(file)); 1183 char buffer[PROC_NUMBUF]; 1184 short oom_score_adj = OOM_SCORE_ADJ_MIN; 1185 size_t len; 1186 1187 if (!task) 1188 return -ESRCH; 1189 oom_score_adj = task->signal->oom_score_adj; 1190 put_task_struct(task); 1191 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj); 1192 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1193 } 1194 1195 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1196 size_t count, loff_t *ppos) 1197 { 1198 char buffer[PROC_NUMBUF]; 1199 int oom_score_adj; 1200 int err; 1201 1202 memset(buffer, 0, sizeof(buffer)); 1203 if (count > sizeof(buffer) - 1) 1204 count = sizeof(buffer) - 1; 1205 if (copy_from_user(buffer, buf, count)) { 1206 err = -EFAULT; 1207 goto out; 1208 } 1209 1210 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 1211 if (err) 1212 goto out; 1213 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1214 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1215 err = -EINVAL; 1216 goto out; 1217 } 1218 1219 err = __set_oom_adj(file, oom_score_adj, false); 1220 out: 1221 return err < 0 ? err : count; 1222 } 1223 1224 static const struct file_operations proc_oom_score_adj_operations = { 1225 .read = oom_score_adj_read, 1226 .write = oom_score_adj_write, 1227 .llseek = default_llseek, 1228 }; 1229 1230 #ifdef CONFIG_AUDITSYSCALL 1231 #define TMPBUFLEN 21 1232 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1233 size_t count, loff_t *ppos) 1234 { 1235 struct inode * inode = file_inode(file); 1236 struct task_struct *task = get_proc_task(inode); 1237 ssize_t length; 1238 char tmpbuf[TMPBUFLEN]; 1239 1240 if (!task) 1241 return -ESRCH; 1242 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1243 from_kuid(file->f_cred->user_ns, 1244 audit_get_loginuid(task))); 1245 put_task_struct(task); 1246 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1247 } 1248 1249 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1250 size_t count, loff_t *ppos) 1251 { 1252 struct inode * inode = file_inode(file); 1253 uid_t loginuid; 1254 kuid_t kloginuid; 1255 int rv; 1256 1257 rcu_read_lock(); 1258 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1259 rcu_read_unlock(); 1260 return -EPERM; 1261 } 1262 rcu_read_unlock(); 1263 1264 if (*ppos != 0) { 1265 /* No partial writes. */ 1266 return -EINVAL; 1267 } 1268 1269 rv = kstrtou32_from_user(buf, count, 10, &loginuid); 1270 if (rv < 0) 1271 return rv; 1272 1273 /* is userspace tring to explicitly UNSET the loginuid? */ 1274 if (loginuid == AUDIT_UID_UNSET) { 1275 kloginuid = INVALID_UID; 1276 } else { 1277 kloginuid = make_kuid(file->f_cred->user_ns, loginuid); 1278 if (!uid_valid(kloginuid)) 1279 return -EINVAL; 1280 } 1281 1282 rv = audit_set_loginuid(kloginuid); 1283 if (rv < 0) 1284 return rv; 1285 return count; 1286 } 1287 1288 static const struct file_operations proc_loginuid_operations = { 1289 .read = proc_loginuid_read, 1290 .write = proc_loginuid_write, 1291 .llseek = generic_file_llseek, 1292 }; 1293 1294 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1295 size_t count, loff_t *ppos) 1296 { 1297 struct inode * inode = file_inode(file); 1298 struct task_struct *task = get_proc_task(inode); 1299 ssize_t length; 1300 char tmpbuf[TMPBUFLEN]; 1301 1302 if (!task) 1303 return -ESRCH; 1304 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1305 audit_get_sessionid(task)); 1306 put_task_struct(task); 1307 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1308 } 1309 1310 static const struct file_operations proc_sessionid_operations = { 1311 .read = proc_sessionid_read, 1312 .llseek = generic_file_llseek, 1313 }; 1314 #endif 1315 1316 #ifdef CONFIG_FAULT_INJECTION 1317 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1318 size_t count, loff_t *ppos) 1319 { 1320 struct task_struct *task = get_proc_task(file_inode(file)); 1321 char buffer[PROC_NUMBUF]; 1322 size_t len; 1323 int make_it_fail; 1324 1325 if (!task) 1326 return -ESRCH; 1327 make_it_fail = task->make_it_fail; 1328 put_task_struct(task); 1329 1330 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1331 1332 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1333 } 1334 1335 static ssize_t proc_fault_inject_write(struct file * file, 1336 const char __user * buf, size_t count, loff_t *ppos) 1337 { 1338 struct task_struct *task; 1339 char buffer[PROC_NUMBUF]; 1340 int make_it_fail; 1341 int rv; 1342 1343 if (!capable(CAP_SYS_RESOURCE)) 1344 return -EPERM; 1345 memset(buffer, 0, sizeof(buffer)); 1346 if (count > sizeof(buffer) - 1) 1347 count = sizeof(buffer) - 1; 1348 if (copy_from_user(buffer, buf, count)) 1349 return -EFAULT; 1350 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail); 1351 if (rv < 0) 1352 return rv; 1353 if (make_it_fail < 0 || make_it_fail > 1) 1354 return -EINVAL; 1355 1356 task = get_proc_task(file_inode(file)); 1357 if (!task) 1358 return -ESRCH; 1359 task->make_it_fail = make_it_fail; 1360 put_task_struct(task); 1361 1362 return count; 1363 } 1364 1365 static const struct file_operations proc_fault_inject_operations = { 1366 .read = proc_fault_inject_read, 1367 .write = proc_fault_inject_write, 1368 .llseek = generic_file_llseek, 1369 }; 1370 #endif 1371 1372 1373 #ifdef CONFIG_SCHED_DEBUG 1374 /* 1375 * Print out various scheduling related per-task fields: 1376 */ 1377 static int sched_show(struct seq_file *m, void *v) 1378 { 1379 struct inode *inode = m->private; 1380 struct task_struct *p; 1381 1382 p = get_proc_task(inode); 1383 if (!p) 1384 return -ESRCH; 1385 proc_sched_show_task(p, m); 1386 1387 put_task_struct(p); 1388 1389 return 0; 1390 } 1391 1392 static ssize_t 1393 sched_write(struct file *file, const char __user *buf, 1394 size_t count, loff_t *offset) 1395 { 1396 struct inode *inode = file_inode(file); 1397 struct task_struct *p; 1398 1399 p = get_proc_task(inode); 1400 if (!p) 1401 return -ESRCH; 1402 proc_sched_set_task(p); 1403 1404 put_task_struct(p); 1405 1406 return count; 1407 } 1408 1409 static int sched_open(struct inode *inode, struct file *filp) 1410 { 1411 return single_open(filp, sched_show, inode); 1412 } 1413 1414 static const struct file_operations proc_pid_sched_operations = { 1415 .open = sched_open, 1416 .read = seq_read, 1417 .write = sched_write, 1418 .llseek = seq_lseek, 1419 .release = single_release, 1420 }; 1421 1422 #endif 1423 1424 #ifdef CONFIG_SCHED_AUTOGROUP 1425 /* 1426 * Print out autogroup related information: 1427 */ 1428 static int sched_autogroup_show(struct seq_file *m, void *v) 1429 { 1430 struct inode *inode = m->private; 1431 struct task_struct *p; 1432 1433 p = get_proc_task(inode); 1434 if (!p) 1435 return -ESRCH; 1436 proc_sched_autogroup_show_task(p, m); 1437 1438 put_task_struct(p); 1439 1440 return 0; 1441 } 1442 1443 static ssize_t 1444 sched_autogroup_write(struct file *file, const char __user *buf, 1445 size_t count, loff_t *offset) 1446 { 1447 struct inode *inode = file_inode(file); 1448 struct task_struct *p; 1449 char buffer[PROC_NUMBUF]; 1450 int nice; 1451 int err; 1452 1453 memset(buffer, 0, sizeof(buffer)); 1454 if (count > sizeof(buffer) - 1) 1455 count = sizeof(buffer) - 1; 1456 if (copy_from_user(buffer, buf, count)) 1457 return -EFAULT; 1458 1459 err = kstrtoint(strstrip(buffer), 0, &nice); 1460 if (err < 0) 1461 return err; 1462 1463 p = get_proc_task(inode); 1464 if (!p) 1465 return -ESRCH; 1466 1467 err = proc_sched_autogroup_set_nice(p, nice); 1468 if (err) 1469 count = err; 1470 1471 put_task_struct(p); 1472 1473 return count; 1474 } 1475 1476 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1477 { 1478 int ret; 1479 1480 ret = single_open(filp, sched_autogroup_show, NULL); 1481 if (!ret) { 1482 struct seq_file *m = filp->private_data; 1483 1484 m->private = inode; 1485 } 1486 return ret; 1487 } 1488 1489 static const struct file_operations proc_pid_sched_autogroup_operations = { 1490 .open = sched_autogroup_open, 1491 .read = seq_read, 1492 .write = sched_autogroup_write, 1493 .llseek = seq_lseek, 1494 .release = single_release, 1495 }; 1496 1497 #endif /* CONFIG_SCHED_AUTOGROUP */ 1498 1499 static ssize_t comm_write(struct file *file, const char __user *buf, 1500 size_t count, loff_t *offset) 1501 { 1502 struct inode *inode = file_inode(file); 1503 struct task_struct *p; 1504 char buffer[TASK_COMM_LEN]; 1505 const size_t maxlen = sizeof(buffer) - 1; 1506 1507 memset(buffer, 0, sizeof(buffer)); 1508 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count)) 1509 return -EFAULT; 1510 1511 p = get_proc_task(inode); 1512 if (!p) 1513 return -ESRCH; 1514 1515 if (same_thread_group(current, p)) 1516 set_task_comm(p, buffer); 1517 else 1518 count = -EINVAL; 1519 1520 put_task_struct(p); 1521 1522 return count; 1523 } 1524 1525 static int comm_show(struct seq_file *m, void *v) 1526 { 1527 struct inode *inode = m->private; 1528 struct task_struct *p; 1529 1530 p = get_proc_task(inode); 1531 if (!p) 1532 return -ESRCH; 1533 1534 task_lock(p); 1535 seq_printf(m, "%s\n", p->comm); 1536 task_unlock(p); 1537 1538 put_task_struct(p); 1539 1540 return 0; 1541 } 1542 1543 static int comm_open(struct inode *inode, struct file *filp) 1544 { 1545 return single_open(filp, comm_show, inode); 1546 } 1547 1548 static const struct file_operations proc_pid_set_comm_operations = { 1549 .open = comm_open, 1550 .read = seq_read, 1551 .write = comm_write, 1552 .llseek = seq_lseek, 1553 .release = single_release, 1554 }; 1555 1556 static int proc_exe_link(struct dentry *dentry, struct path *exe_path) 1557 { 1558 struct task_struct *task; 1559 struct mm_struct *mm; 1560 struct file *exe_file; 1561 1562 task = get_proc_task(d_inode(dentry)); 1563 if (!task) 1564 return -ENOENT; 1565 mm = get_task_mm(task); 1566 put_task_struct(task); 1567 if (!mm) 1568 return -ENOENT; 1569 exe_file = get_mm_exe_file(mm); 1570 mmput(mm); 1571 if (exe_file) { 1572 *exe_path = exe_file->f_path; 1573 path_get(&exe_file->f_path); 1574 fput(exe_file); 1575 return 0; 1576 } else 1577 return -ENOENT; 1578 } 1579 1580 static const char *proc_pid_get_link(struct dentry *dentry, 1581 struct inode *inode, 1582 struct delayed_call *done) 1583 { 1584 struct path path; 1585 int error = -EACCES; 1586 1587 if (!dentry) 1588 return ERR_PTR(-ECHILD); 1589 1590 /* Are we allowed to snoop on the tasks file descriptors? */ 1591 if (!proc_fd_access_allowed(inode)) 1592 goto out; 1593 1594 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1595 if (error) 1596 goto out; 1597 1598 nd_jump_link(&path); 1599 return NULL; 1600 out: 1601 return ERR_PTR(error); 1602 } 1603 1604 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1605 { 1606 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1607 char *pathname; 1608 int len; 1609 1610 if (!tmp) 1611 return -ENOMEM; 1612 1613 pathname = d_path(path, tmp, PAGE_SIZE); 1614 len = PTR_ERR(pathname); 1615 if (IS_ERR(pathname)) 1616 goto out; 1617 len = tmp + PAGE_SIZE - 1 - pathname; 1618 1619 if (len > buflen) 1620 len = buflen; 1621 if (copy_to_user(buffer, pathname, len)) 1622 len = -EFAULT; 1623 out: 1624 free_page((unsigned long)tmp); 1625 return len; 1626 } 1627 1628 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1629 { 1630 int error = -EACCES; 1631 struct inode *inode = d_inode(dentry); 1632 struct path path; 1633 1634 /* Are we allowed to snoop on the tasks file descriptors? */ 1635 if (!proc_fd_access_allowed(inode)) 1636 goto out; 1637 1638 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1639 if (error) 1640 goto out; 1641 1642 error = do_proc_readlink(&path, buffer, buflen); 1643 path_put(&path); 1644 out: 1645 return error; 1646 } 1647 1648 const struct inode_operations proc_pid_link_inode_operations = { 1649 .readlink = proc_pid_readlink, 1650 .get_link = proc_pid_get_link, 1651 .setattr = proc_setattr, 1652 }; 1653 1654 1655 /* building an inode */ 1656 1657 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1658 { 1659 struct inode * inode; 1660 struct proc_inode *ei; 1661 const struct cred *cred; 1662 1663 /* We need a new inode */ 1664 1665 inode = new_inode(sb); 1666 if (!inode) 1667 goto out; 1668 1669 /* Common stuff */ 1670 ei = PROC_I(inode); 1671 inode->i_ino = get_next_ino(); 1672 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1673 inode->i_op = &proc_def_inode_operations; 1674 1675 /* 1676 * grab the reference to task. 1677 */ 1678 ei->pid = get_task_pid(task, PIDTYPE_PID); 1679 if (!ei->pid) 1680 goto out_unlock; 1681 1682 if (task_dumpable(task)) { 1683 rcu_read_lock(); 1684 cred = __task_cred(task); 1685 inode->i_uid = cred->euid; 1686 inode->i_gid = cred->egid; 1687 rcu_read_unlock(); 1688 } 1689 security_task_to_inode(task, inode); 1690 1691 out: 1692 return inode; 1693 1694 out_unlock: 1695 iput(inode); 1696 return NULL; 1697 } 1698 1699 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1700 { 1701 struct inode *inode = d_inode(dentry); 1702 struct task_struct *task; 1703 const struct cred *cred; 1704 struct pid_namespace *pid = dentry->d_sb->s_fs_info; 1705 1706 generic_fillattr(inode, stat); 1707 1708 rcu_read_lock(); 1709 stat->uid = GLOBAL_ROOT_UID; 1710 stat->gid = GLOBAL_ROOT_GID; 1711 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1712 if (task) { 1713 if (!has_pid_permissions(pid, task, 2)) { 1714 rcu_read_unlock(); 1715 /* 1716 * This doesn't prevent learning whether PID exists, 1717 * it only makes getattr() consistent with readdir(). 1718 */ 1719 return -ENOENT; 1720 } 1721 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1722 task_dumpable(task)) { 1723 cred = __task_cred(task); 1724 stat->uid = cred->euid; 1725 stat->gid = cred->egid; 1726 } 1727 } 1728 rcu_read_unlock(); 1729 return 0; 1730 } 1731 1732 /* dentry stuff */ 1733 1734 /* 1735 * Exceptional case: normally we are not allowed to unhash a busy 1736 * directory. In this case, however, we can do it - no aliasing problems 1737 * due to the way we treat inodes. 1738 * 1739 * Rewrite the inode's ownerships here because the owning task may have 1740 * performed a setuid(), etc. 1741 * 1742 * Before the /proc/pid/status file was created the only way to read 1743 * the effective uid of a /process was to stat /proc/pid. Reading 1744 * /proc/pid/status is slow enough that procps and other packages 1745 * kept stating /proc/pid. To keep the rules in /proc simple I have 1746 * made this apply to all per process world readable and executable 1747 * directories. 1748 */ 1749 int pid_revalidate(struct dentry *dentry, unsigned int flags) 1750 { 1751 struct inode *inode; 1752 struct task_struct *task; 1753 const struct cred *cred; 1754 1755 if (flags & LOOKUP_RCU) 1756 return -ECHILD; 1757 1758 inode = d_inode(dentry); 1759 task = get_proc_task(inode); 1760 1761 if (task) { 1762 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1763 task_dumpable(task)) { 1764 rcu_read_lock(); 1765 cred = __task_cred(task); 1766 inode->i_uid = cred->euid; 1767 inode->i_gid = cred->egid; 1768 rcu_read_unlock(); 1769 } else { 1770 inode->i_uid = GLOBAL_ROOT_UID; 1771 inode->i_gid = GLOBAL_ROOT_GID; 1772 } 1773 inode->i_mode &= ~(S_ISUID | S_ISGID); 1774 security_task_to_inode(task, inode); 1775 put_task_struct(task); 1776 return 1; 1777 } 1778 return 0; 1779 } 1780 1781 static inline bool proc_inode_is_dead(struct inode *inode) 1782 { 1783 return !proc_pid(inode)->tasks[PIDTYPE_PID].first; 1784 } 1785 1786 int pid_delete_dentry(const struct dentry *dentry) 1787 { 1788 /* Is the task we represent dead? 1789 * If so, then don't put the dentry on the lru list, 1790 * kill it immediately. 1791 */ 1792 return proc_inode_is_dead(d_inode(dentry)); 1793 } 1794 1795 const struct dentry_operations pid_dentry_operations = 1796 { 1797 .d_revalidate = pid_revalidate, 1798 .d_delete = pid_delete_dentry, 1799 }; 1800 1801 /* Lookups */ 1802 1803 /* 1804 * Fill a directory entry. 1805 * 1806 * If possible create the dcache entry and derive our inode number and 1807 * file type from dcache entry. 1808 * 1809 * Since all of the proc inode numbers are dynamically generated, the inode 1810 * numbers do not exist until the inode is cache. This means creating the 1811 * the dcache entry in readdir is necessary to keep the inode numbers 1812 * reported by readdir in sync with the inode numbers reported 1813 * by stat. 1814 */ 1815 bool proc_fill_cache(struct file *file, struct dir_context *ctx, 1816 const char *name, int len, 1817 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1818 { 1819 struct dentry *child, *dir = file->f_path.dentry; 1820 struct qstr qname = QSTR_INIT(name, len); 1821 struct inode *inode; 1822 unsigned type; 1823 ino_t ino; 1824 1825 child = d_hash_and_lookup(dir, &qname); 1826 if (!child) { 1827 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 1828 child = d_alloc_parallel(dir, &qname, &wq); 1829 if (IS_ERR(child)) 1830 goto end_instantiate; 1831 if (d_in_lookup(child)) { 1832 int err = instantiate(d_inode(dir), child, task, ptr); 1833 d_lookup_done(child); 1834 if (err < 0) { 1835 dput(child); 1836 goto end_instantiate; 1837 } 1838 } 1839 } 1840 inode = d_inode(child); 1841 ino = inode->i_ino; 1842 type = inode->i_mode >> 12; 1843 dput(child); 1844 return dir_emit(ctx, name, len, ino, type); 1845 1846 end_instantiate: 1847 return dir_emit(ctx, name, len, 1, DT_UNKNOWN); 1848 } 1849 1850 /* 1851 * dname_to_vma_addr - maps a dentry name into two unsigned longs 1852 * which represent vma start and end addresses. 1853 */ 1854 static int dname_to_vma_addr(struct dentry *dentry, 1855 unsigned long *start, unsigned long *end) 1856 { 1857 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2) 1858 return -EINVAL; 1859 1860 return 0; 1861 } 1862 1863 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags) 1864 { 1865 unsigned long vm_start, vm_end; 1866 bool exact_vma_exists = false; 1867 struct mm_struct *mm = NULL; 1868 struct task_struct *task; 1869 const struct cred *cred; 1870 struct inode *inode; 1871 int status = 0; 1872 1873 if (flags & LOOKUP_RCU) 1874 return -ECHILD; 1875 1876 inode = d_inode(dentry); 1877 task = get_proc_task(inode); 1878 if (!task) 1879 goto out_notask; 1880 1881 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); 1882 if (IS_ERR_OR_NULL(mm)) 1883 goto out; 1884 1885 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 1886 down_read(&mm->mmap_sem); 1887 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end); 1888 up_read(&mm->mmap_sem); 1889 } 1890 1891 mmput(mm); 1892 1893 if (exact_vma_exists) { 1894 if (task_dumpable(task)) { 1895 rcu_read_lock(); 1896 cred = __task_cred(task); 1897 inode->i_uid = cred->euid; 1898 inode->i_gid = cred->egid; 1899 rcu_read_unlock(); 1900 } else { 1901 inode->i_uid = GLOBAL_ROOT_UID; 1902 inode->i_gid = GLOBAL_ROOT_GID; 1903 } 1904 security_task_to_inode(task, inode); 1905 status = 1; 1906 } 1907 1908 out: 1909 put_task_struct(task); 1910 1911 out_notask: 1912 return status; 1913 } 1914 1915 static const struct dentry_operations tid_map_files_dentry_operations = { 1916 .d_revalidate = map_files_d_revalidate, 1917 .d_delete = pid_delete_dentry, 1918 }; 1919 1920 static int map_files_get_link(struct dentry *dentry, struct path *path) 1921 { 1922 unsigned long vm_start, vm_end; 1923 struct vm_area_struct *vma; 1924 struct task_struct *task; 1925 struct mm_struct *mm; 1926 int rc; 1927 1928 rc = -ENOENT; 1929 task = get_proc_task(d_inode(dentry)); 1930 if (!task) 1931 goto out; 1932 1933 mm = get_task_mm(task); 1934 put_task_struct(task); 1935 if (!mm) 1936 goto out; 1937 1938 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 1939 if (rc) 1940 goto out_mmput; 1941 1942 rc = -ENOENT; 1943 down_read(&mm->mmap_sem); 1944 vma = find_exact_vma(mm, vm_start, vm_end); 1945 if (vma && vma->vm_file) { 1946 *path = vma->vm_file->f_path; 1947 path_get(path); 1948 rc = 0; 1949 } 1950 up_read(&mm->mmap_sem); 1951 1952 out_mmput: 1953 mmput(mm); 1954 out: 1955 return rc; 1956 } 1957 1958 struct map_files_info { 1959 fmode_t mode; 1960 unsigned long len; 1961 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */ 1962 }; 1963 1964 /* 1965 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the 1966 * symlinks may be used to bypass permissions on ancestor directories in the 1967 * path to the file in question. 1968 */ 1969 static const char * 1970 proc_map_files_get_link(struct dentry *dentry, 1971 struct inode *inode, 1972 struct delayed_call *done) 1973 { 1974 if (!capable(CAP_SYS_ADMIN)) 1975 return ERR_PTR(-EPERM); 1976 1977 return proc_pid_get_link(dentry, inode, done); 1978 } 1979 1980 /* 1981 * Identical to proc_pid_link_inode_operations except for get_link() 1982 */ 1983 static const struct inode_operations proc_map_files_link_inode_operations = { 1984 .readlink = proc_pid_readlink, 1985 .get_link = proc_map_files_get_link, 1986 .setattr = proc_setattr, 1987 }; 1988 1989 static int 1990 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry, 1991 struct task_struct *task, const void *ptr) 1992 { 1993 fmode_t mode = (fmode_t)(unsigned long)ptr; 1994 struct proc_inode *ei; 1995 struct inode *inode; 1996 1997 inode = proc_pid_make_inode(dir->i_sb, task); 1998 if (!inode) 1999 return -ENOENT; 2000 2001 ei = PROC_I(inode); 2002 ei->op.proc_get_link = map_files_get_link; 2003 2004 inode->i_op = &proc_map_files_link_inode_operations; 2005 inode->i_size = 64; 2006 inode->i_mode = S_IFLNK; 2007 2008 if (mode & FMODE_READ) 2009 inode->i_mode |= S_IRUSR; 2010 if (mode & FMODE_WRITE) 2011 inode->i_mode |= S_IWUSR; 2012 2013 d_set_d_op(dentry, &tid_map_files_dentry_operations); 2014 d_add(dentry, inode); 2015 2016 return 0; 2017 } 2018 2019 static struct dentry *proc_map_files_lookup(struct inode *dir, 2020 struct dentry *dentry, unsigned int flags) 2021 { 2022 unsigned long vm_start, vm_end; 2023 struct vm_area_struct *vma; 2024 struct task_struct *task; 2025 int result; 2026 struct mm_struct *mm; 2027 2028 result = -ENOENT; 2029 task = get_proc_task(dir); 2030 if (!task) 2031 goto out; 2032 2033 result = -EACCES; 2034 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2035 goto out_put_task; 2036 2037 result = -ENOENT; 2038 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 2039 goto out_put_task; 2040 2041 mm = get_task_mm(task); 2042 if (!mm) 2043 goto out_put_task; 2044 2045 down_read(&mm->mmap_sem); 2046 vma = find_exact_vma(mm, vm_start, vm_end); 2047 if (!vma) 2048 goto out_no_vma; 2049 2050 if (vma->vm_file) 2051 result = proc_map_files_instantiate(dir, dentry, task, 2052 (void *)(unsigned long)vma->vm_file->f_mode); 2053 2054 out_no_vma: 2055 up_read(&mm->mmap_sem); 2056 mmput(mm); 2057 out_put_task: 2058 put_task_struct(task); 2059 out: 2060 return ERR_PTR(result); 2061 } 2062 2063 static const struct inode_operations proc_map_files_inode_operations = { 2064 .lookup = proc_map_files_lookup, 2065 .permission = proc_fd_permission, 2066 .setattr = proc_setattr, 2067 }; 2068 2069 static int 2070 proc_map_files_readdir(struct file *file, struct dir_context *ctx) 2071 { 2072 struct vm_area_struct *vma; 2073 struct task_struct *task; 2074 struct mm_struct *mm; 2075 unsigned long nr_files, pos, i; 2076 struct flex_array *fa = NULL; 2077 struct map_files_info info; 2078 struct map_files_info *p; 2079 int ret; 2080 2081 ret = -ENOENT; 2082 task = get_proc_task(file_inode(file)); 2083 if (!task) 2084 goto out; 2085 2086 ret = -EACCES; 2087 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2088 goto out_put_task; 2089 2090 ret = 0; 2091 if (!dir_emit_dots(file, ctx)) 2092 goto out_put_task; 2093 2094 mm = get_task_mm(task); 2095 if (!mm) 2096 goto out_put_task; 2097 down_read(&mm->mmap_sem); 2098 2099 nr_files = 0; 2100 2101 /* 2102 * We need two passes here: 2103 * 2104 * 1) Collect vmas of mapped files with mmap_sem taken 2105 * 2) Release mmap_sem and instantiate entries 2106 * 2107 * otherwise we get lockdep complained, since filldir() 2108 * routine might require mmap_sem taken in might_fault(). 2109 */ 2110 2111 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 2112 if (vma->vm_file && ++pos > ctx->pos) 2113 nr_files++; 2114 } 2115 2116 if (nr_files) { 2117 fa = flex_array_alloc(sizeof(info), nr_files, 2118 GFP_KERNEL); 2119 if (!fa || flex_array_prealloc(fa, 0, nr_files, 2120 GFP_KERNEL)) { 2121 ret = -ENOMEM; 2122 if (fa) 2123 flex_array_free(fa); 2124 up_read(&mm->mmap_sem); 2125 mmput(mm); 2126 goto out_put_task; 2127 } 2128 for (i = 0, vma = mm->mmap, pos = 2; vma; 2129 vma = vma->vm_next) { 2130 if (!vma->vm_file) 2131 continue; 2132 if (++pos <= ctx->pos) 2133 continue; 2134 2135 info.mode = vma->vm_file->f_mode; 2136 info.len = snprintf(info.name, 2137 sizeof(info.name), "%lx-%lx", 2138 vma->vm_start, vma->vm_end); 2139 if (flex_array_put(fa, i++, &info, GFP_KERNEL)) 2140 BUG(); 2141 } 2142 } 2143 up_read(&mm->mmap_sem); 2144 2145 for (i = 0; i < nr_files; i++) { 2146 p = flex_array_get(fa, i); 2147 if (!proc_fill_cache(file, ctx, 2148 p->name, p->len, 2149 proc_map_files_instantiate, 2150 task, 2151 (void *)(unsigned long)p->mode)) 2152 break; 2153 ctx->pos++; 2154 } 2155 if (fa) 2156 flex_array_free(fa); 2157 mmput(mm); 2158 2159 out_put_task: 2160 put_task_struct(task); 2161 out: 2162 return ret; 2163 } 2164 2165 static const struct file_operations proc_map_files_operations = { 2166 .read = generic_read_dir, 2167 .iterate_shared = proc_map_files_readdir, 2168 .llseek = generic_file_llseek, 2169 }; 2170 2171 #ifdef CONFIG_CHECKPOINT_RESTORE 2172 struct timers_private { 2173 struct pid *pid; 2174 struct task_struct *task; 2175 struct sighand_struct *sighand; 2176 struct pid_namespace *ns; 2177 unsigned long flags; 2178 }; 2179 2180 static void *timers_start(struct seq_file *m, loff_t *pos) 2181 { 2182 struct timers_private *tp = m->private; 2183 2184 tp->task = get_pid_task(tp->pid, PIDTYPE_PID); 2185 if (!tp->task) 2186 return ERR_PTR(-ESRCH); 2187 2188 tp->sighand = lock_task_sighand(tp->task, &tp->flags); 2189 if (!tp->sighand) 2190 return ERR_PTR(-ESRCH); 2191 2192 return seq_list_start(&tp->task->signal->posix_timers, *pos); 2193 } 2194 2195 static void *timers_next(struct seq_file *m, void *v, loff_t *pos) 2196 { 2197 struct timers_private *tp = m->private; 2198 return seq_list_next(v, &tp->task->signal->posix_timers, pos); 2199 } 2200 2201 static void timers_stop(struct seq_file *m, void *v) 2202 { 2203 struct timers_private *tp = m->private; 2204 2205 if (tp->sighand) { 2206 unlock_task_sighand(tp->task, &tp->flags); 2207 tp->sighand = NULL; 2208 } 2209 2210 if (tp->task) { 2211 put_task_struct(tp->task); 2212 tp->task = NULL; 2213 } 2214 } 2215 2216 static int show_timer(struct seq_file *m, void *v) 2217 { 2218 struct k_itimer *timer; 2219 struct timers_private *tp = m->private; 2220 int notify; 2221 static const char * const nstr[] = { 2222 [SIGEV_SIGNAL] = "signal", 2223 [SIGEV_NONE] = "none", 2224 [SIGEV_THREAD] = "thread", 2225 }; 2226 2227 timer = list_entry((struct list_head *)v, struct k_itimer, list); 2228 notify = timer->it_sigev_notify; 2229 2230 seq_printf(m, "ID: %d\n", timer->it_id); 2231 seq_printf(m, "signal: %d/%p\n", 2232 timer->sigq->info.si_signo, 2233 timer->sigq->info.si_value.sival_ptr); 2234 seq_printf(m, "notify: %s/%s.%d\n", 2235 nstr[notify & ~SIGEV_THREAD_ID], 2236 (notify & SIGEV_THREAD_ID) ? "tid" : "pid", 2237 pid_nr_ns(timer->it_pid, tp->ns)); 2238 seq_printf(m, "ClockID: %d\n", timer->it_clock); 2239 2240 return 0; 2241 } 2242 2243 static const struct seq_operations proc_timers_seq_ops = { 2244 .start = timers_start, 2245 .next = timers_next, 2246 .stop = timers_stop, 2247 .show = show_timer, 2248 }; 2249 2250 static int proc_timers_open(struct inode *inode, struct file *file) 2251 { 2252 struct timers_private *tp; 2253 2254 tp = __seq_open_private(file, &proc_timers_seq_ops, 2255 sizeof(struct timers_private)); 2256 if (!tp) 2257 return -ENOMEM; 2258 2259 tp->pid = proc_pid(inode); 2260 tp->ns = inode->i_sb->s_fs_info; 2261 return 0; 2262 } 2263 2264 static const struct file_operations proc_timers_operations = { 2265 .open = proc_timers_open, 2266 .read = seq_read, 2267 .llseek = seq_lseek, 2268 .release = seq_release_private, 2269 }; 2270 #endif 2271 2272 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf, 2273 size_t count, loff_t *offset) 2274 { 2275 struct inode *inode = file_inode(file); 2276 struct task_struct *p; 2277 u64 slack_ns; 2278 int err; 2279 2280 err = kstrtoull_from_user(buf, count, 10, &slack_ns); 2281 if (err < 0) 2282 return err; 2283 2284 p = get_proc_task(inode); 2285 if (!p) 2286 return -ESRCH; 2287 2288 if (ptrace_may_access(p, PTRACE_MODE_ATTACH_FSCREDS)) { 2289 task_lock(p); 2290 if (slack_ns == 0) 2291 p->timer_slack_ns = p->default_timer_slack_ns; 2292 else 2293 p->timer_slack_ns = slack_ns; 2294 task_unlock(p); 2295 } else 2296 count = -EPERM; 2297 2298 put_task_struct(p); 2299 2300 return count; 2301 } 2302 2303 static int timerslack_ns_show(struct seq_file *m, void *v) 2304 { 2305 struct inode *inode = m->private; 2306 struct task_struct *p; 2307 int err = 0; 2308 2309 p = get_proc_task(inode); 2310 if (!p) 2311 return -ESRCH; 2312 2313 if (ptrace_may_access(p, PTRACE_MODE_ATTACH_FSCREDS)) { 2314 task_lock(p); 2315 seq_printf(m, "%llu\n", p->timer_slack_ns); 2316 task_unlock(p); 2317 } else 2318 err = -EPERM; 2319 2320 put_task_struct(p); 2321 2322 return err; 2323 } 2324 2325 static int timerslack_ns_open(struct inode *inode, struct file *filp) 2326 { 2327 return single_open(filp, timerslack_ns_show, inode); 2328 } 2329 2330 static const struct file_operations proc_pid_set_timerslack_ns_operations = { 2331 .open = timerslack_ns_open, 2332 .read = seq_read, 2333 .write = timerslack_ns_write, 2334 .llseek = seq_lseek, 2335 .release = single_release, 2336 }; 2337 2338 static int proc_pident_instantiate(struct inode *dir, 2339 struct dentry *dentry, struct task_struct *task, const void *ptr) 2340 { 2341 const struct pid_entry *p = ptr; 2342 struct inode *inode; 2343 struct proc_inode *ei; 2344 2345 inode = proc_pid_make_inode(dir->i_sb, task); 2346 if (!inode) 2347 goto out; 2348 2349 ei = PROC_I(inode); 2350 inode->i_mode = p->mode; 2351 if (S_ISDIR(inode->i_mode)) 2352 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2353 if (p->iop) 2354 inode->i_op = p->iop; 2355 if (p->fop) 2356 inode->i_fop = p->fop; 2357 ei->op = p->op; 2358 d_set_d_op(dentry, &pid_dentry_operations); 2359 d_add(dentry, inode); 2360 /* Close the race of the process dying before we return the dentry */ 2361 if (pid_revalidate(dentry, 0)) 2362 return 0; 2363 out: 2364 return -ENOENT; 2365 } 2366 2367 static struct dentry *proc_pident_lookup(struct inode *dir, 2368 struct dentry *dentry, 2369 const struct pid_entry *ents, 2370 unsigned int nents) 2371 { 2372 int error; 2373 struct task_struct *task = get_proc_task(dir); 2374 const struct pid_entry *p, *last; 2375 2376 error = -ENOENT; 2377 2378 if (!task) 2379 goto out_no_task; 2380 2381 /* 2382 * Yes, it does not scale. And it should not. Don't add 2383 * new entries into /proc/<tgid>/ without very good reasons. 2384 */ 2385 last = &ents[nents - 1]; 2386 for (p = ents; p <= last; p++) { 2387 if (p->len != dentry->d_name.len) 2388 continue; 2389 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2390 break; 2391 } 2392 if (p > last) 2393 goto out; 2394 2395 error = proc_pident_instantiate(dir, dentry, task, p); 2396 out: 2397 put_task_struct(task); 2398 out_no_task: 2399 return ERR_PTR(error); 2400 } 2401 2402 static int proc_pident_readdir(struct file *file, struct dir_context *ctx, 2403 const struct pid_entry *ents, unsigned int nents) 2404 { 2405 struct task_struct *task = get_proc_task(file_inode(file)); 2406 const struct pid_entry *p; 2407 2408 if (!task) 2409 return -ENOENT; 2410 2411 if (!dir_emit_dots(file, ctx)) 2412 goto out; 2413 2414 if (ctx->pos >= nents + 2) 2415 goto out; 2416 2417 for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) { 2418 if (!proc_fill_cache(file, ctx, p->name, p->len, 2419 proc_pident_instantiate, task, p)) 2420 break; 2421 ctx->pos++; 2422 } 2423 out: 2424 put_task_struct(task); 2425 return 0; 2426 } 2427 2428 #ifdef CONFIG_SECURITY 2429 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2430 size_t count, loff_t *ppos) 2431 { 2432 struct inode * inode = file_inode(file); 2433 char *p = NULL; 2434 ssize_t length; 2435 struct task_struct *task = get_proc_task(inode); 2436 2437 if (!task) 2438 return -ESRCH; 2439 2440 length = security_getprocattr(task, 2441 (char*)file->f_path.dentry->d_name.name, 2442 &p); 2443 put_task_struct(task); 2444 if (length > 0) 2445 length = simple_read_from_buffer(buf, count, ppos, p, length); 2446 kfree(p); 2447 return length; 2448 } 2449 2450 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2451 size_t count, loff_t *ppos) 2452 { 2453 struct inode * inode = file_inode(file); 2454 void *page; 2455 ssize_t length; 2456 struct task_struct *task = get_proc_task(inode); 2457 2458 length = -ESRCH; 2459 if (!task) 2460 goto out_no_task; 2461 if (count > PAGE_SIZE) 2462 count = PAGE_SIZE; 2463 2464 /* No partial writes. */ 2465 length = -EINVAL; 2466 if (*ppos != 0) 2467 goto out; 2468 2469 page = memdup_user(buf, count); 2470 if (IS_ERR(page)) { 2471 length = PTR_ERR(page); 2472 goto out; 2473 } 2474 2475 /* Guard against adverse ptrace interaction */ 2476 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex); 2477 if (length < 0) 2478 goto out_free; 2479 2480 length = security_setprocattr(task, 2481 (char*)file->f_path.dentry->d_name.name, 2482 page, count); 2483 mutex_unlock(&task->signal->cred_guard_mutex); 2484 out_free: 2485 kfree(page); 2486 out: 2487 put_task_struct(task); 2488 out_no_task: 2489 return length; 2490 } 2491 2492 static const struct file_operations proc_pid_attr_operations = { 2493 .read = proc_pid_attr_read, 2494 .write = proc_pid_attr_write, 2495 .llseek = generic_file_llseek, 2496 }; 2497 2498 static const struct pid_entry attr_dir_stuff[] = { 2499 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2500 REG("prev", S_IRUGO, proc_pid_attr_operations), 2501 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2502 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2503 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2504 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2505 }; 2506 2507 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx) 2508 { 2509 return proc_pident_readdir(file, ctx, 2510 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2511 } 2512 2513 static const struct file_operations proc_attr_dir_operations = { 2514 .read = generic_read_dir, 2515 .iterate_shared = proc_attr_dir_readdir, 2516 .llseek = generic_file_llseek, 2517 }; 2518 2519 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2520 struct dentry *dentry, unsigned int flags) 2521 { 2522 return proc_pident_lookup(dir, dentry, 2523 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2524 } 2525 2526 static const struct inode_operations proc_attr_dir_inode_operations = { 2527 .lookup = proc_attr_dir_lookup, 2528 .getattr = pid_getattr, 2529 .setattr = proc_setattr, 2530 }; 2531 2532 #endif 2533 2534 #ifdef CONFIG_ELF_CORE 2535 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2536 size_t count, loff_t *ppos) 2537 { 2538 struct task_struct *task = get_proc_task(file_inode(file)); 2539 struct mm_struct *mm; 2540 char buffer[PROC_NUMBUF]; 2541 size_t len; 2542 int ret; 2543 2544 if (!task) 2545 return -ESRCH; 2546 2547 ret = 0; 2548 mm = get_task_mm(task); 2549 if (mm) { 2550 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2551 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2552 MMF_DUMP_FILTER_SHIFT)); 2553 mmput(mm); 2554 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2555 } 2556 2557 put_task_struct(task); 2558 2559 return ret; 2560 } 2561 2562 static ssize_t proc_coredump_filter_write(struct file *file, 2563 const char __user *buf, 2564 size_t count, 2565 loff_t *ppos) 2566 { 2567 struct task_struct *task; 2568 struct mm_struct *mm; 2569 unsigned int val; 2570 int ret; 2571 int i; 2572 unsigned long mask; 2573 2574 ret = kstrtouint_from_user(buf, count, 0, &val); 2575 if (ret < 0) 2576 return ret; 2577 2578 ret = -ESRCH; 2579 task = get_proc_task(file_inode(file)); 2580 if (!task) 2581 goto out_no_task; 2582 2583 mm = get_task_mm(task); 2584 if (!mm) 2585 goto out_no_mm; 2586 ret = 0; 2587 2588 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2589 if (val & mask) 2590 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2591 else 2592 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2593 } 2594 2595 mmput(mm); 2596 out_no_mm: 2597 put_task_struct(task); 2598 out_no_task: 2599 if (ret < 0) 2600 return ret; 2601 return count; 2602 } 2603 2604 static const struct file_operations proc_coredump_filter_operations = { 2605 .read = proc_coredump_filter_read, 2606 .write = proc_coredump_filter_write, 2607 .llseek = generic_file_llseek, 2608 }; 2609 #endif 2610 2611 #ifdef CONFIG_TASK_IO_ACCOUNTING 2612 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole) 2613 { 2614 struct task_io_accounting acct = task->ioac; 2615 unsigned long flags; 2616 int result; 2617 2618 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2619 if (result) 2620 return result; 2621 2622 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { 2623 result = -EACCES; 2624 goto out_unlock; 2625 } 2626 2627 if (whole && lock_task_sighand(task, &flags)) { 2628 struct task_struct *t = task; 2629 2630 task_io_accounting_add(&acct, &task->signal->ioac); 2631 while_each_thread(task, t) 2632 task_io_accounting_add(&acct, &t->ioac); 2633 2634 unlock_task_sighand(task, &flags); 2635 } 2636 seq_printf(m, 2637 "rchar: %llu\n" 2638 "wchar: %llu\n" 2639 "syscr: %llu\n" 2640 "syscw: %llu\n" 2641 "read_bytes: %llu\n" 2642 "write_bytes: %llu\n" 2643 "cancelled_write_bytes: %llu\n", 2644 (unsigned long long)acct.rchar, 2645 (unsigned long long)acct.wchar, 2646 (unsigned long long)acct.syscr, 2647 (unsigned long long)acct.syscw, 2648 (unsigned long long)acct.read_bytes, 2649 (unsigned long long)acct.write_bytes, 2650 (unsigned long long)acct.cancelled_write_bytes); 2651 result = 0; 2652 2653 out_unlock: 2654 mutex_unlock(&task->signal->cred_guard_mutex); 2655 return result; 2656 } 2657 2658 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2659 struct pid *pid, struct task_struct *task) 2660 { 2661 return do_io_accounting(task, m, 0); 2662 } 2663 2664 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2665 struct pid *pid, struct task_struct *task) 2666 { 2667 return do_io_accounting(task, m, 1); 2668 } 2669 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2670 2671 #ifdef CONFIG_USER_NS 2672 static int proc_id_map_open(struct inode *inode, struct file *file, 2673 const struct seq_operations *seq_ops) 2674 { 2675 struct user_namespace *ns = NULL; 2676 struct task_struct *task; 2677 struct seq_file *seq; 2678 int ret = -EINVAL; 2679 2680 task = get_proc_task(inode); 2681 if (task) { 2682 rcu_read_lock(); 2683 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2684 rcu_read_unlock(); 2685 put_task_struct(task); 2686 } 2687 if (!ns) 2688 goto err; 2689 2690 ret = seq_open(file, seq_ops); 2691 if (ret) 2692 goto err_put_ns; 2693 2694 seq = file->private_data; 2695 seq->private = ns; 2696 2697 return 0; 2698 err_put_ns: 2699 put_user_ns(ns); 2700 err: 2701 return ret; 2702 } 2703 2704 static int proc_id_map_release(struct inode *inode, struct file *file) 2705 { 2706 struct seq_file *seq = file->private_data; 2707 struct user_namespace *ns = seq->private; 2708 put_user_ns(ns); 2709 return seq_release(inode, file); 2710 } 2711 2712 static int proc_uid_map_open(struct inode *inode, struct file *file) 2713 { 2714 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2715 } 2716 2717 static int proc_gid_map_open(struct inode *inode, struct file *file) 2718 { 2719 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2720 } 2721 2722 static int proc_projid_map_open(struct inode *inode, struct file *file) 2723 { 2724 return proc_id_map_open(inode, file, &proc_projid_seq_operations); 2725 } 2726 2727 static const struct file_operations proc_uid_map_operations = { 2728 .open = proc_uid_map_open, 2729 .write = proc_uid_map_write, 2730 .read = seq_read, 2731 .llseek = seq_lseek, 2732 .release = proc_id_map_release, 2733 }; 2734 2735 static const struct file_operations proc_gid_map_operations = { 2736 .open = proc_gid_map_open, 2737 .write = proc_gid_map_write, 2738 .read = seq_read, 2739 .llseek = seq_lseek, 2740 .release = proc_id_map_release, 2741 }; 2742 2743 static const struct file_operations proc_projid_map_operations = { 2744 .open = proc_projid_map_open, 2745 .write = proc_projid_map_write, 2746 .read = seq_read, 2747 .llseek = seq_lseek, 2748 .release = proc_id_map_release, 2749 }; 2750 2751 static int proc_setgroups_open(struct inode *inode, struct file *file) 2752 { 2753 struct user_namespace *ns = NULL; 2754 struct task_struct *task; 2755 int ret; 2756 2757 ret = -ESRCH; 2758 task = get_proc_task(inode); 2759 if (task) { 2760 rcu_read_lock(); 2761 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2762 rcu_read_unlock(); 2763 put_task_struct(task); 2764 } 2765 if (!ns) 2766 goto err; 2767 2768 if (file->f_mode & FMODE_WRITE) { 2769 ret = -EACCES; 2770 if (!ns_capable(ns, CAP_SYS_ADMIN)) 2771 goto err_put_ns; 2772 } 2773 2774 ret = single_open(file, &proc_setgroups_show, ns); 2775 if (ret) 2776 goto err_put_ns; 2777 2778 return 0; 2779 err_put_ns: 2780 put_user_ns(ns); 2781 err: 2782 return ret; 2783 } 2784 2785 static int proc_setgroups_release(struct inode *inode, struct file *file) 2786 { 2787 struct seq_file *seq = file->private_data; 2788 struct user_namespace *ns = seq->private; 2789 int ret = single_release(inode, file); 2790 put_user_ns(ns); 2791 return ret; 2792 } 2793 2794 static const struct file_operations proc_setgroups_operations = { 2795 .open = proc_setgroups_open, 2796 .write = proc_setgroups_write, 2797 .read = seq_read, 2798 .llseek = seq_lseek, 2799 .release = proc_setgroups_release, 2800 }; 2801 #endif /* CONFIG_USER_NS */ 2802 2803 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2804 struct pid *pid, struct task_struct *task) 2805 { 2806 int err = lock_trace(task); 2807 if (!err) { 2808 seq_printf(m, "%08x\n", task->personality); 2809 unlock_trace(task); 2810 } 2811 return err; 2812 } 2813 2814 /* 2815 * Thread groups 2816 */ 2817 static const struct file_operations proc_task_operations; 2818 static const struct inode_operations proc_task_inode_operations; 2819 2820 static const struct pid_entry tgid_base_stuff[] = { 2821 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2822 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2823 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 2824 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2825 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2826 #ifdef CONFIG_NET 2827 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2828 #endif 2829 REG("environ", S_IRUSR, proc_environ_operations), 2830 ONE("auxv", S_IRUSR, proc_pid_auxv), 2831 ONE("status", S_IRUGO, proc_pid_status), 2832 ONE("personality", S_IRUSR, proc_pid_personality), 2833 ONE("limits", S_IRUGO, proc_pid_limits), 2834 #ifdef CONFIG_SCHED_DEBUG 2835 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2836 #endif 2837 #ifdef CONFIG_SCHED_AUTOGROUP 2838 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2839 #endif 2840 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2841 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2842 ONE("syscall", S_IRUSR, proc_pid_syscall), 2843 #endif 2844 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 2845 ONE("stat", S_IRUGO, proc_tgid_stat), 2846 ONE("statm", S_IRUGO, proc_pid_statm), 2847 REG("maps", S_IRUGO, proc_pid_maps_operations), 2848 #ifdef CONFIG_NUMA 2849 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 2850 #endif 2851 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2852 LNK("cwd", proc_cwd_link), 2853 LNK("root", proc_root_link), 2854 LNK("exe", proc_exe_link), 2855 REG("mounts", S_IRUGO, proc_mounts_operations), 2856 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2857 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2858 #ifdef CONFIG_PROC_PAGE_MONITOR 2859 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2860 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 2861 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2862 #endif 2863 #ifdef CONFIG_SECURITY 2864 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2865 #endif 2866 #ifdef CONFIG_KALLSYMS 2867 ONE("wchan", S_IRUGO, proc_pid_wchan), 2868 #endif 2869 #ifdef CONFIG_STACKTRACE 2870 ONE("stack", S_IRUSR, proc_pid_stack), 2871 #endif 2872 #ifdef CONFIG_SCHED_INFO 2873 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 2874 #endif 2875 #ifdef CONFIG_LATENCYTOP 2876 REG("latency", S_IRUGO, proc_lstats_operations), 2877 #endif 2878 #ifdef CONFIG_PROC_PID_CPUSET 2879 ONE("cpuset", S_IRUGO, proc_cpuset_show), 2880 #endif 2881 #ifdef CONFIG_CGROUPS 2882 ONE("cgroup", S_IRUGO, proc_cgroup_show), 2883 #endif 2884 ONE("oom_score", S_IRUGO, proc_oom_score), 2885 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 2886 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2887 #ifdef CONFIG_AUDITSYSCALL 2888 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2889 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2890 #endif 2891 #ifdef CONFIG_FAULT_INJECTION 2892 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2893 #endif 2894 #ifdef CONFIG_ELF_CORE 2895 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2896 #endif 2897 #ifdef CONFIG_TASK_IO_ACCOUNTING 2898 ONE("io", S_IRUSR, proc_tgid_io_accounting), 2899 #endif 2900 #ifdef CONFIG_HARDWALL 2901 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 2902 #endif 2903 #ifdef CONFIG_USER_NS 2904 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 2905 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 2906 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 2907 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 2908 #endif 2909 #ifdef CONFIG_CHECKPOINT_RESTORE 2910 REG("timers", S_IRUGO, proc_timers_operations), 2911 #endif 2912 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations), 2913 }; 2914 2915 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) 2916 { 2917 return proc_pident_readdir(file, ctx, 2918 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2919 } 2920 2921 static const struct file_operations proc_tgid_base_operations = { 2922 .read = generic_read_dir, 2923 .iterate_shared = proc_tgid_base_readdir, 2924 .llseek = generic_file_llseek, 2925 }; 2926 2927 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 2928 { 2929 return proc_pident_lookup(dir, dentry, 2930 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2931 } 2932 2933 static const struct inode_operations proc_tgid_base_inode_operations = { 2934 .lookup = proc_tgid_base_lookup, 2935 .getattr = pid_getattr, 2936 .setattr = proc_setattr, 2937 .permission = proc_pid_permission, 2938 }; 2939 2940 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2941 { 2942 struct dentry *dentry, *leader, *dir; 2943 char buf[PROC_NUMBUF]; 2944 struct qstr name; 2945 2946 name.name = buf; 2947 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2948 /* no ->d_hash() rejects on procfs */ 2949 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2950 if (dentry) { 2951 d_invalidate(dentry); 2952 dput(dentry); 2953 } 2954 2955 if (pid == tgid) 2956 return; 2957 2958 name.name = buf; 2959 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2960 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2961 if (!leader) 2962 goto out; 2963 2964 name.name = "task"; 2965 name.len = strlen(name.name); 2966 dir = d_hash_and_lookup(leader, &name); 2967 if (!dir) 2968 goto out_put_leader; 2969 2970 name.name = buf; 2971 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2972 dentry = d_hash_and_lookup(dir, &name); 2973 if (dentry) { 2974 d_invalidate(dentry); 2975 dput(dentry); 2976 } 2977 2978 dput(dir); 2979 out_put_leader: 2980 dput(leader); 2981 out: 2982 return; 2983 } 2984 2985 /** 2986 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2987 * @task: task that should be flushed. 2988 * 2989 * When flushing dentries from proc, one needs to flush them from global 2990 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2991 * in. This call is supposed to do all of this job. 2992 * 2993 * Looks in the dcache for 2994 * /proc/@pid 2995 * /proc/@tgid/task/@pid 2996 * if either directory is present flushes it and all of it'ts children 2997 * from the dcache. 2998 * 2999 * It is safe and reasonable to cache /proc entries for a task until 3000 * that task exits. After that they just clog up the dcache with 3001 * useless entries, possibly causing useful dcache entries to be 3002 * flushed instead. This routine is proved to flush those useless 3003 * dcache entries at process exit time. 3004 * 3005 * NOTE: This routine is just an optimization so it does not guarantee 3006 * that no dcache entries will exist at process exit time it 3007 * just makes it very unlikely that any will persist. 3008 */ 3009 3010 void proc_flush_task(struct task_struct *task) 3011 { 3012 int i; 3013 struct pid *pid, *tgid; 3014 struct upid *upid; 3015 3016 pid = task_pid(task); 3017 tgid = task_tgid(task); 3018 3019 for (i = 0; i <= pid->level; i++) { 3020 upid = &pid->numbers[i]; 3021 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3022 tgid->numbers[i].nr); 3023 } 3024 } 3025 3026 static int proc_pid_instantiate(struct inode *dir, 3027 struct dentry * dentry, 3028 struct task_struct *task, const void *ptr) 3029 { 3030 struct inode *inode; 3031 3032 inode = proc_pid_make_inode(dir->i_sb, task); 3033 if (!inode) 3034 goto out; 3035 3036 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3037 inode->i_op = &proc_tgid_base_inode_operations; 3038 inode->i_fop = &proc_tgid_base_operations; 3039 inode->i_flags|=S_IMMUTABLE; 3040 3041 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff, 3042 ARRAY_SIZE(tgid_base_stuff))); 3043 3044 d_set_d_op(dentry, &pid_dentry_operations); 3045 3046 d_add(dentry, inode); 3047 /* Close the race of the process dying before we return the dentry */ 3048 if (pid_revalidate(dentry, 0)) 3049 return 0; 3050 out: 3051 return -ENOENT; 3052 } 3053 3054 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3055 { 3056 int result = -ENOENT; 3057 struct task_struct *task; 3058 unsigned tgid; 3059 struct pid_namespace *ns; 3060 3061 tgid = name_to_int(&dentry->d_name); 3062 if (tgid == ~0U) 3063 goto out; 3064 3065 ns = dentry->d_sb->s_fs_info; 3066 rcu_read_lock(); 3067 task = find_task_by_pid_ns(tgid, ns); 3068 if (task) 3069 get_task_struct(task); 3070 rcu_read_unlock(); 3071 if (!task) 3072 goto out; 3073 3074 result = proc_pid_instantiate(dir, dentry, task, NULL); 3075 put_task_struct(task); 3076 out: 3077 return ERR_PTR(result); 3078 } 3079 3080 /* 3081 * Find the first task with tgid >= tgid 3082 * 3083 */ 3084 struct tgid_iter { 3085 unsigned int tgid; 3086 struct task_struct *task; 3087 }; 3088 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3089 { 3090 struct pid *pid; 3091 3092 if (iter.task) 3093 put_task_struct(iter.task); 3094 rcu_read_lock(); 3095 retry: 3096 iter.task = NULL; 3097 pid = find_ge_pid(iter.tgid, ns); 3098 if (pid) { 3099 iter.tgid = pid_nr_ns(pid, ns); 3100 iter.task = pid_task(pid, PIDTYPE_PID); 3101 /* What we to know is if the pid we have find is the 3102 * pid of a thread_group_leader. Testing for task 3103 * being a thread_group_leader is the obvious thing 3104 * todo but there is a window when it fails, due to 3105 * the pid transfer logic in de_thread. 3106 * 3107 * So we perform the straight forward test of seeing 3108 * if the pid we have found is the pid of a thread 3109 * group leader, and don't worry if the task we have 3110 * found doesn't happen to be a thread group leader. 3111 * As we don't care in the case of readdir. 3112 */ 3113 if (!iter.task || !has_group_leader_pid(iter.task)) { 3114 iter.tgid += 1; 3115 goto retry; 3116 } 3117 get_task_struct(iter.task); 3118 } 3119 rcu_read_unlock(); 3120 return iter; 3121 } 3122 3123 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2) 3124 3125 /* for the /proc/ directory itself, after non-process stuff has been done */ 3126 int proc_pid_readdir(struct file *file, struct dir_context *ctx) 3127 { 3128 struct tgid_iter iter; 3129 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info; 3130 loff_t pos = ctx->pos; 3131 3132 if (pos >= PID_MAX_LIMIT + TGID_OFFSET) 3133 return 0; 3134 3135 if (pos == TGID_OFFSET - 2) { 3136 struct inode *inode = d_inode(ns->proc_self); 3137 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) 3138 return 0; 3139 ctx->pos = pos = pos + 1; 3140 } 3141 if (pos == TGID_OFFSET - 1) { 3142 struct inode *inode = d_inode(ns->proc_thread_self); 3143 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) 3144 return 0; 3145 ctx->pos = pos = pos + 1; 3146 } 3147 iter.tgid = pos - TGID_OFFSET; 3148 iter.task = NULL; 3149 for (iter = next_tgid(ns, iter); 3150 iter.task; 3151 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3152 char name[PROC_NUMBUF]; 3153 int len; 3154 if (!has_pid_permissions(ns, iter.task, 2)) 3155 continue; 3156 3157 len = snprintf(name, sizeof(name), "%d", iter.tgid); 3158 ctx->pos = iter.tgid + TGID_OFFSET; 3159 if (!proc_fill_cache(file, ctx, name, len, 3160 proc_pid_instantiate, iter.task, NULL)) { 3161 put_task_struct(iter.task); 3162 return 0; 3163 } 3164 } 3165 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET; 3166 return 0; 3167 } 3168 3169 /* 3170 * proc_tid_comm_permission is a special permission function exclusively 3171 * used for the node /proc/<pid>/task/<tid>/comm. 3172 * It bypasses generic permission checks in the case where a task of the same 3173 * task group attempts to access the node. 3174 * The rationale behind this is that glibc and bionic access this node for 3175 * cross thread naming (pthread_set/getname_np(!self)). However, if 3176 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0, 3177 * which locks out the cross thread naming implementation. 3178 * This function makes sure that the node is always accessible for members of 3179 * same thread group. 3180 */ 3181 static int proc_tid_comm_permission(struct inode *inode, int mask) 3182 { 3183 bool is_same_tgroup; 3184 struct task_struct *task; 3185 3186 task = get_proc_task(inode); 3187 if (!task) 3188 return -ESRCH; 3189 is_same_tgroup = same_thread_group(current, task); 3190 put_task_struct(task); 3191 3192 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) { 3193 /* This file (/proc/<pid>/task/<tid>/comm) can always be 3194 * read or written by the members of the corresponding 3195 * thread group. 3196 */ 3197 return 0; 3198 } 3199 3200 return generic_permission(inode, mask); 3201 } 3202 3203 static const struct inode_operations proc_tid_comm_inode_operations = { 3204 .permission = proc_tid_comm_permission, 3205 }; 3206 3207 /* 3208 * Tasks 3209 */ 3210 static const struct pid_entry tid_base_stuff[] = { 3211 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3212 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3213 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3214 #ifdef CONFIG_NET 3215 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3216 #endif 3217 REG("environ", S_IRUSR, proc_environ_operations), 3218 ONE("auxv", S_IRUSR, proc_pid_auxv), 3219 ONE("status", S_IRUGO, proc_pid_status), 3220 ONE("personality", S_IRUSR, proc_pid_personality), 3221 ONE("limits", S_IRUGO, proc_pid_limits), 3222 #ifdef CONFIG_SCHED_DEBUG 3223 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3224 #endif 3225 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR, 3226 &proc_tid_comm_inode_operations, 3227 &proc_pid_set_comm_operations, {}), 3228 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3229 ONE("syscall", S_IRUSR, proc_pid_syscall), 3230 #endif 3231 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 3232 ONE("stat", S_IRUGO, proc_tid_stat), 3233 ONE("statm", S_IRUGO, proc_pid_statm), 3234 REG("maps", S_IRUGO, proc_tid_maps_operations), 3235 #ifdef CONFIG_PROC_CHILDREN 3236 REG("children", S_IRUGO, proc_tid_children_operations), 3237 #endif 3238 #ifdef CONFIG_NUMA 3239 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations), 3240 #endif 3241 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3242 LNK("cwd", proc_cwd_link), 3243 LNK("root", proc_root_link), 3244 LNK("exe", proc_exe_link), 3245 REG("mounts", S_IRUGO, proc_mounts_operations), 3246 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3247 #ifdef CONFIG_PROC_PAGE_MONITOR 3248 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3249 REG("smaps", S_IRUGO, proc_tid_smaps_operations), 3250 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3251 #endif 3252 #ifdef CONFIG_SECURITY 3253 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3254 #endif 3255 #ifdef CONFIG_KALLSYMS 3256 ONE("wchan", S_IRUGO, proc_pid_wchan), 3257 #endif 3258 #ifdef CONFIG_STACKTRACE 3259 ONE("stack", S_IRUSR, proc_pid_stack), 3260 #endif 3261 #ifdef CONFIG_SCHED_INFO 3262 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 3263 #endif 3264 #ifdef CONFIG_LATENCYTOP 3265 REG("latency", S_IRUGO, proc_lstats_operations), 3266 #endif 3267 #ifdef CONFIG_PROC_PID_CPUSET 3268 ONE("cpuset", S_IRUGO, proc_cpuset_show), 3269 #endif 3270 #ifdef CONFIG_CGROUPS 3271 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3272 #endif 3273 ONE("oom_score", S_IRUGO, proc_oom_score), 3274 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3275 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3276 #ifdef CONFIG_AUDITSYSCALL 3277 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3278 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3279 #endif 3280 #ifdef CONFIG_FAULT_INJECTION 3281 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3282 #endif 3283 #ifdef CONFIG_TASK_IO_ACCOUNTING 3284 ONE("io", S_IRUSR, proc_tid_io_accounting), 3285 #endif 3286 #ifdef CONFIG_HARDWALL 3287 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 3288 #endif 3289 #ifdef CONFIG_USER_NS 3290 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3291 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3292 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3293 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3294 #endif 3295 }; 3296 3297 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx) 3298 { 3299 return proc_pident_readdir(file, ctx, 3300 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3301 } 3302 3303 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3304 { 3305 return proc_pident_lookup(dir, dentry, 3306 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3307 } 3308 3309 static const struct file_operations proc_tid_base_operations = { 3310 .read = generic_read_dir, 3311 .iterate_shared = proc_tid_base_readdir, 3312 .llseek = generic_file_llseek, 3313 }; 3314 3315 static const struct inode_operations proc_tid_base_inode_operations = { 3316 .lookup = proc_tid_base_lookup, 3317 .getattr = pid_getattr, 3318 .setattr = proc_setattr, 3319 }; 3320 3321 static int proc_task_instantiate(struct inode *dir, 3322 struct dentry *dentry, struct task_struct *task, const void *ptr) 3323 { 3324 struct inode *inode; 3325 inode = proc_pid_make_inode(dir->i_sb, task); 3326 3327 if (!inode) 3328 goto out; 3329 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3330 inode->i_op = &proc_tid_base_inode_operations; 3331 inode->i_fop = &proc_tid_base_operations; 3332 inode->i_flags|=S_IMMUTABLE; 3333 3334 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff, 3335 ARRAY_SIZE(tid_base_stuff))); 3336 3337 d_set_d_op(dentry, &pid_dentry_operations); 3338 3339 d_add(dentry, inode); 3340 /* Close the race of the process dying before we return the dentry */ 3341 if (pid_revalidate(dentry, 0)) 3342 return 0; 3343 out: 3344 return -ENOENT; 3345 } 3346 3347 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3348 { 3349 int result = -ENOENT; 3350 struct task_struct *task; 3351 struct task_struct *leader = get_proc_task(dir); 3352 unsigned tid; 3353 struct pid_namespace *ns; 3354 3355 if (!leader) 3356 goto out_no_task; 3357 3358 tid = name_to_int(&dentry->d_name); 3359 if (tid == ~0U) 3360 goto out; 3361 3362 ns = dentry->d_sb->s_fs_info; 3363 rcu_read_lock(); 3364 task = find_task_by_pid_ns(tid, ns); 3365 if (task) 3366 get_task_struct(task); 3367 rcu_read_unlock(); 3368 if (!task) 3369 goto out; 3370 if (!same_thread_group(leader, task)) 3371 goto out_drop_task; 3372 3373 result = proc_task_instantiate(dir, dentry, task, NULL); 3374 out_drop_task: 3375 put_task_struct(task); 3376 out: 3377 put_task_struct(leader); 3378 out_no_task: 3379 return ERR_PTR(result); 3380 } 3381 3382 /* 3383 * Find the first tid of a thread group to return to user space. 3384 * 3385 * Usually this is just the thread group leader, but if the users 3386 * buffer was too small or there was a seek into the middle of the 3387 * directory we have more work todo. 3388 * 3389 * In the case of a short read we start with find_task_by_pid. 3390 * 3391 * In the case of a seek we start with the leader and walk nr 3392 * threads past it. 3393 */ 3394 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos, 3395 struct pid_namespace *ns) 3396 { 3397 struct task_struct *pos, *task; 3398 unsigned long nr = f_pos; 3399 3400 if (nr != f_pos) /* 32bit overflow? */ 3401 return NULL; 3402 3403 rcu_read_lock(); 3404 task = pid_task(pid, PIDTYPE_PID); 3405 if (!task) 3406 goto fail; 3407 3408 /* Attempt to start with the tid of a thread */ 3409 if (tid && nr) { 3410 pos = find_task_by_pid_ns(tid, ns); 3411 if (pos && same_thread_group(pos, task)) 3412 goto found; 3413 } 3414 3415 /* If nr exceeds the number of threads there is nothing todo */ 3416 if (nr >= get_nr_threads(task)) 3417 goto fail; 3418 3419 /* If we haven't found our starting place yet start 3420 * with the leader and walk nr threads forward. 3421 */ 3422 pos = task = task->group_leader; 3423 do { 3424 if (!nr--) 3425 goto found; 3426 } while_each_thread(task, pos); 3427 fail: 3428 pos = NULL; 3429 goto out; 3430 found: 3431 get_task_struct(pos); 3432 out: 3433 rcu_read_unlock(); 3434 return pos; 3435 } 3436 3437 /* 3438 * Find the next thread in the thread list. 3439 * Return NULL if there is an error or no next thread. 3440 * 3441 * The reference to the input task_struct is released. 3442 */ 3443 static struct task_struct *next_tid(struct task_struct *start) 3444 { 3445 struct task_struct *pos = NULL; 3446 rcu_read_lock(); 3447 if (pid_alive(start)) { 3448 pos = next_thread(start); 3449 if (thread_group_leader(pos)) 3450 pos = NULL; 3451 else 3452 get_task_struct(pos); 3453 } 3454 rcu_read_unlock(); 3455 put_task_struct(start); 3456 return pos; 3457 } 3458 3459 /* for the /proc/TGID/task/ directories */ 3460 static int proc_task_readdir(struct file *file, struct dir_context *ctx) 3461 { 3462 struct inode *inode = file_inode(file); 3463 struct task_struct *task; 3464 struct pid_namespace *ns; 3465 int tid; 3466 3467 if (proc_inode_is_dead(inode)) 3468 return -ENOENT; 3469 3470 if (!dir_emit_dots(file, ctx)) 3471 return 0; 3472 3473 /* f_version caches the tgid value that the last readdir call couldn't 3474 * return. lseek aka telldir automagically resets f_version to 0. 3475 */ 3476 ns = inode->i_sb->s_fs_info; 3477 tid = (int)file->f_version; 3478 file->f_version = 0; 3479 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); 3480 task; 3481 task = next_tid(task), ctx->pos++) { 3482 char name[PROC_NUMBUF]; 3483 int len; 3484 tid = task_pid_nr_ns(task, ns); 3485 len = snprintf(name, sizeof(name), "%d", tid); 3486 if (!proc_fill_cache(file, ctx, name, len, 3487 proc_task_instantiate, task, NULL)) { 3488 /* returning this tgid failed, save it as the first 3489 * pid for the next readir call */ 3490 file->f_version = (u64)tid; 3491 put_task_struct(task); 3492 break; 3493 } 3494 } 3495 3496 return 0; 3497 } 3498 3499 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3500 { 3501 struct inode *inode = d_inode(dentry); 3502 struct task_struct *p = get_proc_task(inode); 3503 generic_fillattr(inode, stat); 3504 3505 if (p) { 3506 stat->nlink += get_nr_threads(p); 3507 put_task_struct(p); 3508 } 3509 3510 return 0; 3511 } 3512 3513 static const struct inode_operations proc_task_inode_operations = { 3514 .lookup = proc_task_lookup, 3515 .getattr = proc_task_getattr, 3516 .setattr = proc_setattr, 3517 .permission = proc_pid_permission, 3518 }; 3519 3520 static const struct file_operations proc_task_operations = { 3521 .read = generic_read_dir, 3522 .iterate_shared = proc_task_readdir, 3523 .llseek = generic_file_llseek, 3524 }; 3525