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