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 #ifdef CONFIG_KALLSYMS 404 /* 405 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 406 * Returns the resolved symbol. If that fails, simply return the address. 407 */ 408 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns, 409 struct pid *pid, struct task_struct *task) 410 { 411 unsigned long wchan; 412 char symname[KSYM_NAME_LEN]; 413 414 wchan = get_wchan(task); 415 416 if (wchan && ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS) 417 && !lookup_symbol_name(wchan, symname)) 418 seq_printf(m, "%s", symname); 419 else 420 seq_putc(m, '0'); 421 422 return 0; 423 } 424 #endif /* CONFIG_KALLSYMS */ 425 426 static int lock_trace(struct task_struct *task) 427 { 428 int err = mutex_lock_killable(&task->signal->cred_guard_mutex); 429 if (err) 430 return err; 431 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) { 432 mutex_unlock(&task->signal->cred_guard_mutex); 433 return -EPERM; 434 } 435 return 0; 436 } 437 438 static void unlock_trace(struct task_struct *task) 439 { 440 mutex_unlock(&task->signal->cred_guard_mutex); 441 } 442 443 #ifdef CONFIG_STACKTRACE 444 445 #define MAX_STACK_TRACE_DEPTH 64 446 447 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, 448 struct pid *pid, struct task_struct *task) 449 { 450 struct stack_trace trace; 451 unsigned long *entries; 452 int err; 453 int i; 454 455 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL); 456 if (!entries) 457 return -ENOMEM; 458 459 trace.nr_entries = 0; 460 trace.max_entries = MAX_STACK_TRACE_DEPTH; 461 trace.entries = entries; 462 trace.skip = 0; 463 464 err = lock_trace(task); 465 if (!err) { 466 save_stack_trace_tsk(task, &trace); 467 468 for (i = 0; i < trace.nr_entries; i++) { 469 seq_printf(m, "[<%pK>] %pB\n", 470 (void *)entries[i], (void *)entries[i]); 471 } 472 unlock_trace(task); 473 } 474 kfree(entries); 475 476 return err; 477 } 478 #endif 479 480 #ifdef CONFIG_SCHED_INFO 481 /* 482 * Provides /proc/PID/schedstat 483 */ 484 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, 485 struct pid *pid, struct task_struct *task) 486 { 487 if (unlikely(!sched_info_on())) 488 seq_printf(m, "0 0 0\n"); 489 else 490 seq_printf(m, "%llu %llu %lu\n", 491 (unsigned long long)task->se.sum_exec_runtime, 492 (unsigned long long)task->sched_info.run_delay, 493 task->sched_info.pcount); 494 495 return 0; 496 } 497 #endif 498 499 #ifdef CONFIG_LATENCYTOP 500 static int lstats_show_proc(struct seq_file *m, void *v) 501 { 502 int i; 503 struct inode *inode = m->private; 504 struct task_struct *task = get_proc_task(inode); 505 506 if (!task) 507 return -ESRCH; 508 seq_puts(m, "Latency Top version : v0.1\n"); 509 for (i = 0; i < 32; i++) { 510 struct latency_record *lr = &task->latency_record[i]; 511 if (lr->backtrace[0]) { 512 int q; 513 seq_printf(m, "%i %li %li", 514 lr->count, lr->time, lr->max); 515 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 516 unsigned long bt = lr->backtrace[q]; 517 if (!bt) 518 break; 519 if (bt == ULONG_MAX) 520 break; 521 seq_printf(m, " %ps", (void *)bt); 522 } 523 seq_putc(m, '\n'); 524 } 525 526 } 527 put_task_struct(task); 528 return 0; 529 } 530 531 static int lstats_open(struct inode *inode, struct file *file) 532 { 533 return single_open(file, lstats_show_proc, inode); 534 } 535 536 static ssize_t lstats_write(struct file *file, const char __user *buf, 537 size_t count, loff_t *offs) 538 { 539 struct task_struct *task = get_proc_task(file_inode(file)); 540 541 if (!task) 542 return -ESRCH; 543 clear_all_latency_tracing(task); 544 put_task_struct(task); 545 546 return count; 547 } 548 549 static const struct file_operations proc_lstats_operations = { 550 .open = lstats_open, 551 .read = seq_read, 552 .write = lstats_write, 553 .llseek = seq_lseek, 554 .release = single_release, 555 }; 556 557 #endif 558 559 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns, 560 struct pid *pid, struct task_struct *task) 561 { 562 unsigned long totalpages = totalram_pages + total_swap_pages; 563 unsigned long points = 0; 564 565 points = oom_badness(task, NULL, NULL, totalpages) * 566 1000 / totalpages; 567 seq_printf(m, "%lu\n", points); 568 569 return 0; 570 } 571 572 struct limit_names { 573 const char *name; 574 const char *unit; 575 }; 576 577 static const struct limit_names lnames[RLIM_NLIMITS] = { 578 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 579 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 580 [RLIMIT_DATA] = {"Max data size", "bytes"}, 581 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 582 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 583 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 584 [RLIMIT_NPROC] = {"Max processes", "processes"}, 585 [RLIMIT_NOFILE] = {"Max open files", "files"}, 586 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 587 [RLIMIT_AS] = {"Max address space", "bytes"}, 588 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 589 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 590 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 591 [RLIMIT_NICE] = {"Max nice priority", NULL}, 592 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 593 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 594 }; 595 596 /* Display limits for a process */ 597 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns, 598 struct pid *pid, struct task_struct *task) 599 { 600 unsigned int i; 601 unsigned long flags; 602 603 struct rlimit rlim[RLIM_NLIMITS]; 604 605 if (!lock_task_sighand(task, &flags)) 606 return 0; 607 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 608 unlock_task_sighand(task, &flags); 609 610 /* 611 * print the file header 612 */ 613 seq_printf(m, "%-25s %-20s %-20s %-10s\n", 614 "Limit", "Soft Limit", "Hard Limit", "Units"); 615 616 for (i = 0; i < RLIM_NLIMITS; i++) { 617 if (rlim[i].rlim_cur == RLIM_INFINITY) 618 seq_printf(m, "%-25s %-20s ", 619 lnames[i].name, "unlimited"); 620 else 621 seq_printf(m, "%-25s %-20lu ", 622 lnames[i].name, rlim[i].rlim_cur); 623 624 if (rlim[i].rlim_max == RLIM_INFINITY) 625 seq_printf(m, "%-20s ", "unlimited"); 626 else 627 seq_printf(m, "%-20lu ", rlim[i].rlim_max); 628 629 if (lnames[i].unit) 630 seq_printf(m, "%-10s\n", lnames[i].unit); 631 else 632 seq_putc(m, '\n'); 633 } 634 635 return 0; 636 } 637 638 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 639 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns, 640 struct pid *pid, struct task_struct *task) 641 { 642 long nr; 643 unsigned long args[6], sp, pc; 644 int res; 645 646 res = lock_trace(task); 647 if (res) 648 return res; 649 650 if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) 651 seq_puts(m, "running\n"); 652 else if (nr < 0) 653 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc); 654 else 655 seq_printf(m, 656 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", 657 nr, 658 args[0], args[1], args[2], args[3], args[4], args[5], 659 sp, pc); 660 unlock_trace(task); 661 662 return 0; 663 } 664 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 665 666 /************************************************************************/ 667 /* Here the fs part begins */ 668 /************************************************************************/ 669 670 /* permission checks */ 671 static int proc_fd_access_allowed(struct inode *inode) 672 { 673 struct task_struct *task; 674 int allowed = 0; 675 /* Allow access to a task's file descriptors if it is us or we 676 * may use ptrace attach to the process and find out that 677 * information. 678 */ 679 task = get_proc_task(inode); 680 if (task) { 681 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 682 put_task_struct(task); 683 } 684 return allowed; 685 } 686 687 int proc_setattr(struct dentry *dentry, struct iattr *attr) 688 { 689 int error; 690 struct inode *inode = d_inode(dentry); 691 692 if (attr->ia_valid & ATTR_MODE) 693 return -EPERM; 694 695 error = setattr_prepare(dentry, attr); 696 if (error) 697 return error; 698 699 setattr_copy(inode, attr); 700 mark_inode_dirty(inode); 701 return 0; 702 } 703 704 /* 705 * May current process learn task's sched/cmdline info (for hide_pid_min=1) 706 * or euid/egid (for hide_pid_min=2)? 707 */ 708 static bool has_pid_permissions(struct pid_namespace *pid, 709 struct task_struct *task, 710 int hide_pid_min) 711 { 712 if (pid->hide_pid < hide_pid_min) 713 return true; 714 if (in_group_p(pid->pid_gid)) 715 return true; 716 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 717 } 718 719 720 static int proc_pid_permission(struct inode *inode, int mask) 721 { 722 struct pid_namespace *pid = inode->i_sb->s_fs_info; 723 struct task_struct *task; 724 bool has_perms; 725 726 task = get_proc_task(inode); 727 if (!task) 728 return -ESRCH; 729 has_perms = has_pid_permissions(pid, task, 1); 730 put_task_struct(task); 731 732 if (!has_perms) { 733 if (pid->hide_pid == 2) { 734 /* 735 * Let's make getdents(), stat(), and open() 736 * consistent with each other. If a process 737 * may not stat() a file, it shouldn't be seen 738 * in procfs at all. 739 */ 740 return -ENOENT; 741 } 742 743 return -EPERM; 744 } 745 return generic_permission(inode, mask); 746 } 747 748 749 750 static const struct inode_operations proc_def_inode_operations = { 751 .setattr = proc_setattr, 752 }; 753 754 static int proc_single_show(struct seq_file *m, void *v) 755 { 756 struct inode *inode = m->private; 757 struct pid_namespace *ns; 758 struct pid *pid; 759 struct task_struct *task; 760 int ret; 761 762 ns = inode->i_sb->s_fs_info; 763 pid = proc_pid(inode); 764 task = get_pid_task(pid, PIDTYPE_PID); 765 if (!task) 766 return -ESRCH; 767 768 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 769 770 put_task_struct(task); 771 return ret; 772 } 773 774 static int proc_single_open(struct inode *inode, struct file *filp) 775 { 776 return single_open(filp, proc_single_show, inode); 777 } 778 779 static const struct file_operations proc_single_file_operations = { 780 .open = proc_single_open, 781 .read = seq_read, 782 .llseek = seq_lseek, 783 .release = single_release, 784 }; 785 786 787 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode) 788 { 789 struct task_struct *task = get_proc_task(inode); 790 struct mm_struct *mm = ERR_PTR(-ESRCH); 791 792 if (task) { 793 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS); 794 put_task_struct(task); 795 796 if (!IS_ERR_OR_NULL(mm)) { 797 /* ensure this mm_struct can't be freed */ 798 atomic_inc(&mm->mm_count); 799 /* but do not pin its memory */ 800 mmput(mm); 801 } 802 } 803 804 return mm; 805 } 806 807 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) 808 { 809 struct mm_struct *mm = proc_mem_open(inode, mode); 810 811 if (IS_ERR(mm)) 812 return PTR_ERR(mm); 813 814 file->private_data = mm; 815 return 0; 816 } 817 818 static int mem_open(struct inode *inode, struct file *file) 819 { 820 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH); 821 822 /* OK to pass negative loff_t, we can catch out-of-range */ 823 file->f_mode |= FMODE_UNSIGNED_OFFSET; 824 825 return ret; 826 } 827 828 static ssize_t mem_rw(struct file *file, char __user *buf, 829 size_t count, loff_t *ppos, int write) 830 { 831 struct mm_struct *mm = file->private_data; 832 unsigned long addr = *ppos; 833 ssize_t copied; 834 char *page; 835 unsigned int flags; 836 837 if (!mm) 838 return 0; 839 840 page = (char *)__get_free_page(GFP_TEMPORARY); 841 if (!page) 842 return -ENOMEM; 843 844 copied = 0; 845 if (!atomic_inc_not_zero(&mm->mm_users)) 846 goto free; 847 848 /* Maybe we should limit FOLL_FORCE to actual ptrace users? */ 849 flags = FOLL_FORCE; 850 if (write) 851 flags |= FOLL_WRITE; 852 853 while (count > 0) { 854 int this_len = min_t(int, count, PAGE_SIZE); 855 856 if (write && copy_from_user(page, buf, this_len)) { 857 copied = -EFAULT; 858 break; 859 } 860 861 this_len = access_remote_vm(mm, addr, page, this_len, flags); 862 if (!this_len) { 863 if (!copied) 864 copied = -EIO; 865 break; 866 } 867 868 if (!write && copy_to_user(buf, page, this_len)) { 869 copied = -EFAULT; 870 break; 871 } 872 873 buf += this_len; 874 addr += this_len; 875 copied += this_len; 876 count -= this_len; 877 } 878 *ppos = addr; 879 880 mmput(mm); 881 free: 882 free_page((unsigned long) page); 883 return copied; 884 } 885 886 static ssize_t mem_read(struct file *file, char __user *buf, 887 size_t count, loff_t *ppos) 888 { 889 return mem_rw(file, buf, count, ppos, 0); 890 } 891 892 static ssize_t mem_write(struct file *file, const char __user *buf, 893 size_t count, loff_t *ppos) 894 { 895 return mem_rw(file, (char __user*)buf, count, ppos, 1); 896 } 897 898 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 899 { 900 switch (orig) { 901 case 0: 902 file->f_pos = offset; 903 break; 904 case 1: 905 file->f_pos += offset; 906 break; 907 default: 908 return -EINVAL; 909 } 910 force_successful_syscall_return(); 911 return file->f_pos; 912 } 913 914 static int mem_release(struct inode *inode, struct file *file) 915 { 916 struct mm_struct *mm = file->private_data; 917 if (mm) 918 mmdrop(mm); 919 return 0; 920 } 921 922 static const struct file_operations proc_mem_operations = { 923 .llseek = mem_lseek, 924 .read = mem_read, 925 .write = mem_write, 926 .open = mem_open, 927 .release = mem_release, 928 }; 929 930 static int environ_open(struct inode *inode, struct file *file) 931 { 932 return __mem_open(inode, file, PTRACE_MODE_READ); 933 } 934 935 static ssize_t environ_read(struct file *file, char __user *buf, 936 size_t count, loff_t *ppos) 937 { 938 char *page; 939 unsigned long src = *ppos; 940 int ret = 0; 941 struct mm_struct *mm = file->private_data; 942 unsigned long env_start, env_end; 943 944 /* Ensure the process spawned far enough to have an environment. */ 945 if (!mm || !mm->env_end) 946 return 0; 947 948 page = (char *)__get_free_page(GFP_TEMPORARY); 949 if (!page) 950 return -ENOMEM; 951 952 ret = 0; 953 if (!atomic_inc_not_zero(&mm->mm_users)) 954 goto free; 955 956 down_read(&mm->mmap_sem); 957 env_start = mm->env_start; 958 env_end = mm->env_end; 959 up_read(&mm->mmap_sem); 960 961 while (count > 0) { 962 size_t this_len, max_len; 963 int retval; 964 965 if (src >= (env_end - env_start)) 966 break; 967 968 this_len = env_end - (env_start + src); 969 970 max_len = min_t(size_t, PAGE_SIZE, count); 971 this_len = min(max_len, this_len); 972 973 retval = access_remote_vm(mm, (env_start + src), page, this_len, 0); 974 975 if (retval <= 0) { 976 ret = retval; 977 break; 978 } 979 980 if (copy_to_user(buf, page, retval)) { 981 ret = -EFAULT; 982 break; 983 } 984 985 ret += retval; 986 src += retval; 987 buf += retval; 988 count -= retval; 989 } 990 *ppos = src; 991 mmput(mm); 992 993 free: 994 free_page((unsigned long) page); 995 return ret; 996 } 997 998 static const struct file_operations proc_environ_operations = { 999 .open = environ_open, 1000 .read = environ_read, 1001 .llseek = generic_file_llseek, 1002 .release = mem_release, 1003 }; 1004 1005 static int auxv_open(struct inode *inode, struct file *file) 1006 { 1007 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS); 1008 } 1009 1010 static ssize_t auxv_read(struct file *file, char __user *buf, 1011 size_t count, loff_t *ppos) 1012 { 1013 struct mm_struct *mm = file->private_data; 1014 unsigned int nwords = 0; 1015 1016 if (!mm) 1017 return 0; 1018 do { 1019 nwords += 2; 1020 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 1021 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv, 1022 nwords * sizeof(mm->saved_auxv[0])); 1023 } 1024 1025 static const struct file_operations proc_auxv_operations = { 1026 .open = auxv_open, 1027 .read = auxv_read, 1028 .llseek = generic_file_llseek, 1029 .release = mem_release, 1030 }; 1031 1032 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count, 1033 loff_t *ppos) 1034 { 1035 struct task_struct *task = get_proc_task(file_inode(file)); 1036 char buffer[PROC_NUMBUF]; 1037 int oom_adj = OOM_ADJUST_MIN; 1038 size_t len; 1039 1040 if (!task) 1041 return -ESRCH; 1042 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX) 1043 oom_adj = OOM_ADJUST_MAX; 1044 else 1045 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) / 1046 OOM_SCORE_ADJ_MAX; 1047 put_task_struct(task); 1048 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj); 1049 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1050 } 1051 1052 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy) 1053 { 1054 static DEFINE_MUTEX(oom_adj_mutex); 1055 struct mm_struct *mm = NULL; 1056 struct task_struct *task; 1057 int err = 0; 1058 1059 task = get_proc_task(file_inode(file)); 1060 if (!task) 1061 return -ESRCH; 1062 1063 mutex_lock(&oom_adj_mutex); 1064 if (legacy) { 1065 if (oom_adj < task->signal->oom_score_adj && 1066 !capable(CAP_SYS_RESOURCE)) { 1067 err = -EACCES; 1068 goto err_unlock; 1069 } 1070 /* 1071 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use 1072 * /proc/pid/oom_score_adj instead. 1073 */ 1074 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 1075 current->comm, task_pid_nr(current), task_pid_nr(task), 1076 task_pid_nr(task)); 1077 } else { 1078 if ((short)oom_adj < task->signal->oom_score_adj_min && 1079 !capable(CAP_SYS_RESOURCE)) { 1080 err = -EACCES; 1081 goto err_unlock; 1082 } 1083 } 1084 1085 /* 1086 * Make sure we will check other processes sharing the mm if this is 1087 * not vfrok which wants its own oom_score_adj. 1088 * pin the mm so it doesn't go away and get reused after task_unlock 1089 */ 1090 if (!task->vfork_done) { 1091 struct task_struct *p = find_lock_task_mm(task); 1092 1093 if (p) { 1094 if (atomic_read(&p->mm->mm_users) > 1) { 1095 mm = p->mm; 1096 atomic_inc(&mm->mm_count); 1097 } 1098 task_unlock(p); 1099 } 1100 } 1101 1102 task->signal->oom_score_adj = oom_adj; 1103 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1104 task->signal->oom_score_adj_min = (short)oom_adj; 1105 trace_oom_score_adj_update(task); 1106 1107 if (mm) { 1108 struct task_struct *p; 1109 1110 rcu_read_lock(); 1111 for_each_process(p) { 1112 if (same_thread_group(task, p)) 1113 continue; 1114 1115 /* do not touch kernel threads or the global init */ 1116 if (p->flags & PF_KTHREAD || is_global_init(p)) 1117 continue; 1118 1119 task_lock(p); 1120 if (!p->vfork_done && process_shares_mm(p, mm)) { 1121 pr_info("updating oom_score_adj for %d (%s) from %d to %d because it shares mm with %d (%s). Report if this is unexpected.\n", 1122 task_pid_nr(p), p->comm, 1123 p->signal->oom_score_adj, oom_adj, 1124 task_pid_nr(task), task->comm); 1125 p->signal->oom_score_adj = oom_adj; 1126 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1127 p->signal->oom_score_adj_min = (short)oom_adj; 1128 } 1129 task_unlock(p); 1130 } 1131 rcu_read_unlock(); 1132 mmdrop(mm); 1133 } 1134 err_unlock: 1135 mutex_unlock(&oom_adj_mutex); 1136 put_task_struct(task); 1137 return err; 1138 } 1139 1140 /* 1141 * /proc/pid/oom_adj exists solely for backwards compatibility with previous 1142 * kernels. The effective policy is defined by oom_score_adj, which has a 1143 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly. 1144 * Values written to oom_adj are simply mapped linearly to oom_score_adj. 1145 * Processes that become oom disabled via oom_adj will still be oom disabled 1146 * with this implementation. 1147 * 1148 * oom_adj cannot be removed since existing userspace binaries use it. 1149 */ 1150 static ssize_t oom_adj_write(struct file *file, const char __user *buf, 1151 size_t count, loff_t *ppos) 1152 { 1153 char buffer[PROC_NUMBUF]; 1154 int oom_adj; 1155 int err; 1156 1157 memset(buffer, 0, sizeof(buffer)); 1158 if (count > sizeof(buffer) - 1) 1159 count = sizeof(buffer) - 1; 1160 if (copy_from_user(buffer, buf, count)) { 1161 err = -EFAULT; 1162 goto out; 1163 } 1164 1165 err = kstrtoint(strstrip(buffer), 0, &oom_adj); 1166 if (err) 1167 goto out; 1168 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) && 1169 oom_adj != OOM_DISABLE) { 1170 err = -EINVAL; 1171 goto out; 1172 } 1173 1174 /* 1175 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 1176 * value is always attainable. 1177 */ 1178 if (oom_adj == OOM_ADJUST_MAX) 1179 oom_adj = OOM_SCORE_ADJ_MAX; 1180 else 1181 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE; 1182 1183 err = __set_oom_adj(file, oom_adj, true); 1184 out: 1185 return err < 0 ? err : count; 1186 } 1187 1188 static const struct file_operations proc_oom_adj_operations = { 1189 .read = oom_adj_read, 1190 .write = oom_adj_write, 1191 .llseek = generic_file_llseek, 1192 }; 1193 1194 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 1195 size_t count, loff_t *ppos) 1196 { 1197 struct task_struct *task = get_proc_task(file_inode(file)); 1198 char buffer[PROC_NUMBUF]; 1199 short oom_score_adj = OOM_SCORE_ADJ_MIN; 1200 size_t len; 1201 1202 if (!task) 1203 return -ESRCH; 1204 oom_score_adj = task->signal->oom_score_adj; 1205 put_task_struct(task); 1206 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj); 1207 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1208 } 1209 1210 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1211 size_t count, loff_t *ppos) 1212 { 1213 char buffer[PROC_NUMBUF]; 1214 int oom_score_adj; 1215 int err; 1216 1217 memset(buffer, 0, sizeof(buffer)); 1218 if (count > sizeof(buffer) - 1) 1219 count = sizeof(buffer) - 1; 1220 if (copy_from_user(buffer, buf, count)) { 1221 err = -EFAULT; 1222 goto out; 1223 } 1224 1225 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 1226 if (err) 1227 goto out; 1228 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1229 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1230 err = -EINVAL; 1231 goto out; 1232 } 1233 1234 err = __set_oom_adj(file, oom_score_adj, false); 1235 out: 1236 return err < 0 ? err : count; 1237 } 1238 1239 static const struct file_operations proc_oom_score_adj_operations = { 1240 .read = oom_score_adj_read, 1241 .write = oom_score_adj_write, 1242 .llseek = default_llseek, 1243 }; 1244 1245 #ifdef CONFIG_AUDITSYSCALL 1246 #define TMPBUFLEN 21 1247 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1248 size_t count, loff_t *ppos) 1249 { 1250 struct inode * inode = file_inode(file); 1251 struct task_struct *task = get_proc_task(inode); 1252 ssize_t length; 1253 char tmpbuf[TMPBUFLEN]; 1254 1255 if (!task) 1256 return -ESRCH; 1257 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1258 from_kuid(file->f_cred->user_ns, 1259 audit_get_loginuid(task))); 1260 put_task_struct(task); 1261 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1262 } 1263 1264 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1265 size_t count, loff_t *ppos) 1266 { 1267 struct inode * inode = file_inode(file); 1268 uid_t loginuid; 1269 kuid_t kloginuid; 1270 int rv; 1271 1272 rcu_read_lock(); 1273 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1274 rcu_read_unlock(); 1275 return -EPERM; 1276 } 1277 rcu_read_unlock(); 1278 1279 if (*ppos != 0) { 1280 /* No partial writes. */ 1281 return -EINVAL; 1282 } 1283 1284 rv = kstrtou32_from_user(buf, count, 10, &loginuid); 1285 if (rv < 0) 1286 return rv; 1287 1288 /* is userspace tring to explicitly UNSET the loginuid? */ 1289 if (loginuid == AUDIT_UID_UNSET) { 1290 kloginuid = INVALID_UID; 1291 } else { 1292 kloginuid = make_kuid(file->f_cred->user_ns, loginuid); 1293 if (!uid_valid(kloginuid)) 1294 return -EINVAL; 1295 } 1296 1297 rv = audit_set_loginuid(kloginuid); 1298 if (rv < 0) 1299 return rv; 1300 return count; 1301 } 1302 1303 static const struct file_operations proc_loginuid_operations = { 1304 .read = proc_loginuid_read, 1305 .write = proc_loginuid_write, 1306 .llseek = generic_file_llseek, 1307 }; 1308 1309 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1310 size_t count, loff_t *ppos) 1311 { 1312 struct inode * inode = file_inode(file); 1313 struct task_struct *task = get_proc_task(inode); 1314 ssize_t length; 1315 char tmpbuf[TMPBUFLEN]; 1316 1317 if (!task) 1318 return -ESRCH; 1319 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1320 audit_get_sessionid(task)); 1321 put_task_struct(task); 1322 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1323 } 1324 1325 static const struct file_operations proc_sessionid_operations = { 1326 .read = proc_sessionid_read, 1327 .llseek = generic_file_llseek, 1328 }; 1329 #endif 1330 1331 #ifdef CONFIG_FAULT_INJECTION 1332 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1333 size_t count, loff_t *ppos) 1334 { 1335 struct task_struct *task = get_proc_task(file_inode(file)); 1336 char buffer[PROC_NUMBUF]; 1337 size_t len; 1338 int make_it_fail; 1339 1340 if (!task) 1341 return -ESRCH; 1342 make_it_fail = task->make_it_fail; 1343 put_task_struct(task); 1344 1345 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1346 1347 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1348 } 1349 1350 static ssize_t proc_fault_inject_write(struct file * file, 1351 const char __user * buf, size_t count, loff_t *ppos) 1352 { 1353 struct task_struct *task; 1354 char buffer[PROC_NUMBUF]; 1355 int make_it_fail; 1356 int rv; 1357 1358 if (!capable(CAP_SYS_RESOURCE)) 1359 return -EPERM; 1360 memset(buffer, 0, sizeof(buffer)); 1361 if (count > sizeof(buffer) - 1) 1362 count = sizeof(buffer) - 1; 1363 if (copy_from_user(buffer, buf, count)) 1364 return -EFAULT; 1365 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail); 1366 if (rv < 0) 1367 return rv; 1368 if (make_it_fail < 0 || make_it_fail > 1) 1369 return -EINVAL; 1370 1371 task = get_proc_task(file_inode(file)); 1372 if (!task) 1373 return -ESRCH; 1374 task->make_it_fail = make_it_fail; 1375 put_task_struct(task); 1376 1377 return count; 1378 } 1379 1380 static const struct file_operations proc_fault_inject_operations = { 1381 .read = proc_fault_inject_read, 1382 .write = proc_fault_inject_write, 1383 .llseek = generic_file_llseek, 1384 }; 1385 #endif 1386 1387 1388 #ifdef CONFIG_SCHED_DEBUG 1389 /* 1390 * Print out various scheduling related per-task fields: 1391 */ 1392 static int sched_show(struct seq_file *m, void *v) 1393 { 1394 struct inode *inode = m->private; 1395 struct task_struct *p; 1396 1397 p = get_proc_task(inode); 1398 if (!p) 1399 return -ESRCH; 1400 proc_sched_show_task(p, m); 1401 1402 put_task_struct(p); 1403 1404 return 0; 1405 } 1406 1407 static ssize_t 1408 sched_write(struct file *file, const char __user *buf, 1409 size_t count, loff_t *offset) 1410 { 1411 struct inode *inode = file_inode(file); 1412 struct task_struct *p; 1413 1414 p = get_proc_task(inode); 1415 if (!p) 1416 return -ESRCH; 1417 proc_sched_set_task(p); 1418 1419 put_task_struct(p); 1420 1421 return count; 1422 } 1423 1424 static int sched_open(struct inode *inode, struct file *filp) 1425 { 1426 return single_open(filp, sched_show, inode); 1427 } 1428 1429 static const struct file_operations proc_pid_sched_operations = { 1430 .open = sched_open, 1431 .read = seq_read, 1432 .write = sched_write, 1433 .llseek = seq_lseek, 1434 .release = single_release, 1435 }; 1436 1437 #endif 1438 1439 #ifdef CONFIG_SCHED_AUTOGROUP 1440 /* 1441 * Print out autogroup related information: 1442 */ 1443 static int sched_autogroup_show(struct seq_file *m, void *v) 1444 { 1445 struct inode *inode = m->private; 1446 struct task_struct *p; 1447 1448 p = get_proc_task(inode); 1449 if (!p) 1450 return -ESRCH; 1451 proc_sched_autogroup_show_task(p, m); 1452 1453 put_task_struct(p); 1454 1455 return 0; 1456 } 1457 1458 static ssize_t 1459 sched_autogroup_write(struct file *file, const char __user *buf, 1460 size_t count, loff_t *offset) 1461 { 1462 struct inode *inode = file_inode(file); 1463 struct task_struct *p; 1464 char buffer[PROC_NUMBUF]; 1465 int nice; 1466 int err; 1467 1468 memset(buffer, 0, sizeof(buffer)); 1469 if (count > sizeof(buffer) - 1) 1470 count = sizeof(buffer) - 1; 1471 if (copy_from_user(buffer, buf, count)) 1472 return -EFAULT; 1473 1474 err = kstrtoint(strstrip(buffer), 0, &nice); 1475 if (err < 0) 1476 return err; 1477 1478 p = get_proc_task(inode); 1479 if (!p) 1480 return -ESRCH; 1481 1482 err = proc_sched_autogroup_set_nice(p, nice); 1483 if (err) 1484 count = err; 1485 1486 put_task_struct(p); 1487 1488 return count; 1489 } 1490 1491 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1492 { 1493 int ret; 1494 1495 ret = single_open(filp, sched_autogroup_show, NULL); 1496 if (!ret) { 1497 struct seq_file *m = filp->private_data; 1498 1499 m->private = inode; 1500 } 1501 return ret; 1502 } 1503 1504 static const struct file_operations proc_pid_sched_autogroup_operations = { 1505 .open = sched_autogroup_open, 1506 .read = seq_read, 1507 .write = sched_autogroup_write, 1508 .llseek = seq_lseek, 1509 .release = single_release, 1510 }; 1511 1512 #endif /* CONFIG_SCHED_AUTOGROUP */ 1513 1514 static ssize_t comm_write(struct file *file, const char __user *buf, 1515 size_t count, loff_t *offset) 1516 { 1517 struct inode *inode = file_inode(file); 1518 struct task_struct *p; 1519 char buffer[TASK_COMM_LEN]; 1520 const size_t maxlen = sizeof(buffer) - 1; 1521 1522 memset(buffer, 0, sizeof(buffer)); 1523 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count)) 1524 return -EFAULT; 1525 1526 p = get_proc_task(inode); 1527 if (!p) 1528 return -ESRCH; 1529 1530 if (same_thread_group(current, p)) 1531 set_task_comm(p, buffer); 1532 else 1533 count = -EINVAL; 1534 1535 put_task_struct(p); 1536 1537 return count; 1538 } 1539 1540 static int comm_show(struct seq_file *m, void *v) 1541 { 1542 struct inode *inode = m->private; 1543 struct task_struct *p; 1544 1545 p = get_proc_task(inode); 1546 if (!p) 1547 return -ESRCH; 1548 1549 task_lock(p); 1550 seq_printf(m, "%s\n", p->comm); 1551 task_unlock(p); 1552 1553 put_task_struct(p); 1554 1555 return 0; 1556 } 1557 1558 static int comm_open(struct inode *inode, struct file *filp) 1559 { 1560 return single_open(filp, comm_show, inode); 1561 } 1562 1563 static const struct file_operations proc_pid_set_comm_operations = { 1564 .open = comm_open, 1565 .read = seq_read, 1566 .write = comm_write, 1567 .llseek = seq_lseek, 1568 .release = single_release, 1569 }; 1570 1571 static int proc_exe_link(struct dentry *dentry, struct path *exe_path) 1572 { 1573 struct task_struct *task; 1574 struct file *exe_file; 1575 1576 task = get_proc_task(d_inode(dentry)); 1577 if (!task) 1578 return -ENOENT; 1579 exe_file = get_task_exe_file(task); 1580 put_task_struct(task); 1581 if (exe_file) { 1582 *exe_path = exe_file->f_path; 1583 path_get(&exe_file->f_path); 1584 fput(exe_file); 1585 return 0; 1586 } else 1587 return -ENOENT; 1588 } 1589 1590 static const char *proc_pid_get_link(struct dentry *dentry, 1591 struct inode *inode, 1592 struct delayed_call *done) 1593 { 1594 struct path path; 1595 int error = -EACCES; 1596 1597 if (!dentry) 1598 return ERR_PTR(-ECHILD); 1599 1600 /* Are we allowed to snoop on the tasks file descriptors? */ 1601 if (!proc_fd_access_allowed(inode)) 1602 goto out; 1603 1604 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1605 if (error) 1606 goto out; 1607 1608 nd_jump_link(&path); 1609 return NULL; 1610 out: 1611 return ERR_PTR(error); 1612 } 1613 1614 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1615 { 1616 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1617 char *pathname; 1618 int len; 1619 1620 if (!tmp) 1621 return -ENOMEM; 1622 1623 pathname = d_path(path, tmp, PAGE_SIZE); 1624 len = PTR_ERR(pathname); 1625 if (IS_ERR(pathname)) 1626 goto out; 1627 len = tmp + PAGE_SIZE - 1 - pathname; 1628 1629 if (len > buflen) 1630 len = buflen; 1631 if (copy_to_user(buffer, pathname, len)) 1632 len = -EFAULT; 1633 out: 1634 free_page((unsigned long)tmp); 1635 return len; 1636 } 1637 1638 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1639 { 1640 int error = -EACCES; 1641 struct inode *inode = d_inode(dentry); 1642 struct path path; 1643 1644 /* Are we allowed to snoop on the tasks file descriptors? */ 1645 if (!proc_fd_access_allowed(inode)) 1646 goto out; 1647 1648 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1649 if (error) 1650 goto out; 1651 1652 error = do_proc_readlink(&path, buffer, buflen); 1653 path_put(&path); 1654 out: 1655 return error; 1656 } 1657 1658 const struct inode_operations proc_pid_link_inode_operations = { 1659 .readlink = proc_pid_readlink, 1660 .get_link = proc_pid_get_link, 1661 .setattr = proc_setattr, 1662 }; 1663 1664 1665 /* building an inode */ 1666 1667 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1668 { 1669 struct inode * inode; 1670 struct proc_inode *ei; 1671 const struct cred *cred; 1672 1673 /* We need a new inode */ 1674 1675 inode = new_inode(sb); 1676 if (!inode) 1677 goto out; 1678 1679 /* Common stuff */ 1680 ei = PROC_I(inode); 1681 inode->i_ino = get_next_ino(); 1682 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 1683 inode->i_op = &proc_def_inode_operations; 1684 1685 /* 1686 * grab the reference to task. 1687 */ 1688 ei->pid = get_task_pid(task, PIDTYPE_PID); 1689 if (!ei->pid) 1690 goto out_unlock; 1691 1692 if (task_dumpable(task)) { 1693 rcu_read_lock(); 1694 cred = __task_cred(task); 1695 inode->i_uid = cred->euid; 1696 inode->i_gid = cred->egid; 1697 rcu_read_unlock(); 1698 } 1699 security_task_to_inode(task, inode); 1700 1701 out: 1702 return inode; 1703 1704 out_unlock: 1705 iput(inode); 1706 return NULL; 1707 } 1708 1709 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1710 { 1711 struct inode *inode = d_inode(dentry); 1712 struct task_struct *task; 1713 const struct cred *cred; 1714 struct pid_namespace *pid = dentry->d_sb->s_fs_info; 1715 1716 generic_fillattr(inode, stat); 1717 1718 rcu_read_lock(); 1719 stat->uid = GLOBAL_ROOT_UID; 1720 stat->gid = GLOBAL_ROOT_GID; 1721 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1722 if (task) { 1723 if (!has_pid_permissions(pid, task, 2)) { 1724 rcu_read_unlock(); 1725 /* 1726 * This doesn't prevent learning whether PID exists, 1727 * it only makes getattr() consistent with readdir(). 1728 */ 1729 return -ENOENT; 1730 } 1731 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1732 task_dumpable(task)) { 1733 cred = __task_cred(task); 1734 stat->uid = cred->euid; 1735 stat->gid = cred->egid; 1736 } 1737 } 1738 rcu_read_unlock(); 1739 return 0; 1740 } 1741 1742 /* dentry stuff */ 1743 1744 /* 1745 * Exceptional case: normally we are not allowed to unhash a busy 1746 * directory. In this case, however, we can do it - no aliasing problems 1747 * due to the way we treat inodes. 1748 * 1749 * Rewrite the inode's ownerships here because the owning task may have 1750 * performed a setuid(), etc. 1751 * 1752 * Before the /proc/pid/status file was created the only way to read 1753 * the effective uid of a /process was to stat /proc/pid. Reading 1754 * /proc/pid/status is slow enough that procps and other packages 1755 * kept stating /proc/pid. To keep the rules in /proc simple I have 1756 * made this apply to all per process world readable and executable 1757 * directories. 1758 */ 1759 int pid_revalidate(struct dentry *dentry, unsigned int flags) 1760 { 1761 struct inode *inode; 1762 struct task_struct *task; 1763 const struct cred *cred; 1764 1765 if (flags & LOOKUP_RCU) 1766 return -ECHILD; 1767 1768 inode = d_inode(dentry); 1769 task = get_proc_task(inode); 1770 1771 if (task) { 1772 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1773 task_dumpable(task)) { 1774 rcu_read_lock(); 1775 cred = __task_cred(task); 1776 inode->i_uid = cred->euid; 1777 inode->i_gid = cred->egid; 1778 rcu_read_unlock(); 1779 } else { 1780 inode->i_uid = GLOBAL_ROOT_UID; 1781 inode->i_gid = GLOBAL_ROOT_GID; 1782 } 1783 inode->i_mode &= ~(S_ISUID | S_ISGID); 1784 security_task_to_inode(task, inode); 1785 put_task_struct(task); 1786 return 1; 1787 } 1788 return 0; 1789 } 1790 1791 static inline bool proc_inode_is_dead(struct inode *inode) 1792 { 1793 return !proc_pid(inode)->tasks[PIDTYPE_PID].first; 1794 } 1795 1796 int pid_delete_dentry(const struct dentry *dentry) 1797 { 1798 /* Is the task we represent dead? 1799 * If so, then don't put the dentry on the lru list, 1800 * kill it immediately. 1801 */ 1802 return proc_inode_is_dead(d_inode(dentry)); 1803 } 1804 1805 const struct dentry_operations pid_dentry_operations = 1806 { 1807 .d_revalidate = pid_revalidate, 1808 .d_delete = pid_delete_dentry, 1809 }; 1810 1811 /* Lookups */ 1812 1813 /* 1814 * Fill a directory entry. 1815 * 1816 * If possible create the dcache entry and derive our inode number and 1817 * file type from dcache entry. 1818 * 1819 * Since all of the proc inode numbers are dynamically generated, the inode 1820 * numbers do not exist until the inode is cache. This means creating the 1821 * the dcache entry in readdir is necessary to keep the inode numbers 1822 * reported by readdir in sync with the inode numbers reported 1823 * by stat. 1824 */ 1825 bool proc_fill_cache(struct file *file, struct dir_context *ctx, 1826 const char *name, int len, 1827 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1828 { 1829 struct dentry *child, *dir = file->f_path.dentry; 1830 struct qstr qname = QSTR_INIT(name, len); 1831 struct inode *inode; 1832 unsigned type; 1833 ino_t ino; 1834 1835 child = d_hash_and_lookup(dir, &qname); 1836 if (!child) { 1837 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 1838 child = d_alloc_parallel(dir, &qname, &wq); 1839 if (IS_ERR(child)) 1840 goto end_instantiate; 1841 if (d_in_lookup(child)) { 1842 int err = instantiate(d_inode(dir), child, task, ptr); 1843 d_lookup_done(child); 1844 if (err < 0) { 1845 dput(child); 1846 goto end_instantiate; 1847 } 1848 } 1849 } 1850 inode = d_inode(child); 1851 ino = inode->i_ino; 1852 type = inode->i_mode >> 12; 1853 dput(child); 1854 return dir_emit(ctx, name, len, ino, type); 1855 1856 end_instantiate: 1857 return dir_emit(ctx, name, len, 1, DT_UNKNOWN); 1858 } 1859 1860 /* 1861 * dname_to_vma_addr - maps a dentry name into two unsigned longs 1862 * which represent vma start and end addresses. 1863 */ 1864 static int dname_to_vma_addr(struct dentry *dentry, 1865 unsigned long *start, unsigned long *end) 1866 { 1867 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2) 1868 return -EINVAL; 1869 1870 return 0; 1871 } 1872 1873 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags) 1874 { 1875 unsigned long vm_start, vm_end; 1876 bool exact_vma_exists = false; 1877 struct mm_struct *mm = NULL; 1878 struct task_struct *task; 1879 const struct cred *cred; 1880 struct inode *inode; 1881 int status = 0; 1882 1883 if (flags & LOOKUP_RCU) 1884 return -ECHILD; 1885 1886 inode = d_inode(dentry); 1887 task = get_proc_task(inode); 1888 if (!task) 1889 goto out_notask; 1890 1891 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); 1892 if (IS_ERR_OR_NULL(mm)) 1893 goto out; 1894 1895 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 1896 down_read(&mm->mmap_sem); 1897 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end); 1898 up_read(&mm->mmap_sem); 1899 } 1900 1901 mmput(mm); 1902 1903 if (exact_vma_exists) { 1904 if (task_dumpable(task)) { 1905 rcu_read_lock(); 1906 cred = __task_cred(task); 1907 inode->i_uid = cred->euid; 1908 inode->i_gid = cred->egid; 1909 rcu_read_unlock(); 1910 } else { 1911 inode->i_uid = GLOBAL_ROOT_UID; 1912 inode->i_gid = GLOBAL_ROOT_GID; 1913 } 1914 security_task_to_inode(task, inode); 1915 status = 1; 1916 } 1917 1918 out: 1919 put_task_struct(task); 1920 1921 out_notask: 1922 return status; 1923 } 1924 1925 static const struct dentry_operations tid_map_files_dentry_operations = { 1926 .d_revalidate = map_files_d_revalidate, 1927 .d_delete = pid_delete_dentry, 1928 }; 1929 1930 static int map_files_get_link(struct dentry *dentry, struct path *path) 1931 { 1932 unsigned long vm_start, vm_end; 1933 struct vm_area_struct *vma; 1934 struct task_struct *task; 1935 struct mm_struct *mm; 1936 int rc; 1937 1938 rc = -ENOENT; 1939 task = get_proc_task(d_inode(dentry)); 1940 if (!task) 1941 goto out; 1942 1943 mm = get_task_mm(task); 1944 put_task_struct(task); 1945 if (!mm) 1946 goto out; 1947 1948 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 1949 if (rc) 1950 goto out_mmput; 1951 1952 rc = -ENOENT; 1953 down_read(&mm->mmap_sem); 1954 vma = find_exact_vma(mm, vm_start, vm_end); 1955 if (vma && vma->vm_file) { 1956 *path = vma->vm_file->f_path; 1957 path_get(path); 1958 rc = 0; 1959 } 1960 up_read(&mm->mmap_sem); 1961 1962 out_mmput: 1963 mmput(mm); 1964 out: 1965 return rc; 1966 } 1967 1968 struct map_files_info { 1969 fmode_t mode; 1970 unsigned long len; 1971 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */ 1972 }; 1973 1974 /* 1975 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the 1976 * symlinks may be used to bypass permissions on ancestor directories in the 1977 * path to the file in question. 1978 */ 1979 static const char * 1980 proc_map_files_get_link(struct dentry *dentry, 1981 struct inode *inode, 1982 struct delayed_call *done) 1983 { 1984 if (!capable(CAP_SYS_ADMIN)) 1985 return ERR_PTR(-EPERM); 1986 1987 return proc_pid_get_link(dentry, inode, done); 1988 } 1989 1990 /* 1991 * Identical to proc_pid_link_inode_operations except for get_link() 1992 */ 1993 static const struct inode_operations proc_map_files_link_inode_operations = { 1994 .readlink = proc_pid_readlink, 1995 .get_link = proc_map_files_get_link, 1996 .setattr = proc_setattr, 1997 }; 1998 1999 static int 2000 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry, 2001 struct task_struct *task, const void *ptr) 2002 { 2003 fmode_t mode = (fmode_t)(unsigned long)ptr; 2004 struct proc_inode *ei; 2005 struct inode *inode; 2006 2007 inode = proc_pid_make_inode(dir->i_sb, task); 2008 if (!inode) 2009 return -ENOENT; 2010 2011 ei = PROC_I(inode); 2012 ei->op.proc_get_link = map_files_get_link; 2013 2014 inode->i_op = &proc_map_files_link_inode_operations; 2015 inode->i_size = 64; 2016 inode->i_mode = S_IFLNK; 2017 2018 if (mode & FMODE_READ) 2019 inode->i_mode |= S_IRUSR; 2020 if (mode & FMODE_WRITE) 2021 inode->i_mode |= S_IWUSR; 2022 2023 d_set_d_op(dentry, &tid_map_files_dentry_operations); 2024 d_add(dentry, inode); 2025 2026 return 0; 2027 } 2028 2029 static struct dentry *proc_map_files_lookup(struct inode *dir, 2030 struct dentry *dentry, unsigned int flags) 2031 { 2032 unsigned long vm_start, vm_end; 2033 struct vm_area_struct *vma; 2034 struct task_struct *task; 2035 int result; 2036 struct mm_struct *mm; 2037 2038 result = -ENOENT; 2039 task = get_proc_task(dir); 2040 if (!task) 2041 goto out; 2042 2043 result = -EACCES; 2044 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2045 goto out_put_task; 2046 2047 result = -ENOENT; 2048 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 2049 goto out_put_task; 2050 2051 mm = get_task_mm(task); 2052 if (!mm) 2053 goto out_put_task; 2054 2055 down_read(&mm->mmap_sem); 2056 vma = find_exact_vma(mm, vm_start, vm_end); 2057 if (!vma) 2058 goto out_no_vma; 2059 2060 if (vma->vm_file) 2061 result = proc_map_files_instantiate(dir, dentry, task, 2062 (void *)(unsigned long)vma->vm_file->f_mode); 2063 2064 out_no_vma: 2065 up_read(&mm->mmap_sem); 2066 mmput(mm); 2067 out_put_task: 2068 put_task_struct(task); 2069 out: 2070 return ERR_PTR(result); 2071 } 2072 2073 static const struct inode_operations proc_map_files_inode_operations = { 2074 .lookup = proc_map_files_lookup, 2075 .permission = proc_fd_permission, 2076 .setattr = proc_setattr, 2077 }; 2078 2079 static int 2080 proc_map_files_readdir(struct file *file, struct dir_context *ctx) 2081 { 2082 struct vm_area_struct *vma; 2083 struct task_struct *task; 2084 struct mm_struct *mm; 2085 unsigned long nr_files, pos, i; 2086 struct flex_array *fa = NULL; 2087 struct map_files_info info; 2088 struct map_files_info *p; 2089 int ret; 2090 2091 ret = -ENOENT; 2092 task = get_proc_task(file_inode(file)); 2093 if (!task) 2094 goto out; 2095 2096 ret = -EACCES; 2097 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2098 goto out_put_task; 2099 2100 ret = 0; 2101 if (!dir_emit_dots(file, ctx)) 2102 goto out_put_task; 2103 2104 mm = get_task_mm(task); 2105 if (!mm) 2106 goto out_put_task; 2107 down_read(&mm->mmap_sem); 2108 2109 nr_files = 0; 2110 2111 /* 2112 * We need two passes here: 2113 * 2114 * 1) Collect vmas of mapped files with mmap_sem taken 2115 * 2) Release mmap_sem and instantiate entries 2116 * 2117 * otherwise we get lockdep complained, since filldir() 2118 * routine might require mmap_sem taken in might_fault(). 2119 */ 2120 2121 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 2122 if (vma->vm_file && ++pos > ctx->pos) 2123 nr_files++; 2124 } 2125 2126 if (nr_files) { 2127 fa = flex_array_alloc(sizeof(info), nr_files, 2128 GFP_KERNEL); 2129 if (!fa || flex_array_prealloc(fa, 0, nr_files, 2130 GFP_KERNEL)) { 2131 ret = -ENOMEM; 2132 if (fa) 2133 flex_array_free(fa); 2134 up_read(&mm->mmap_sem); 2135 mmput(mm); 2136 goto out_put_task; 2137 } 2138 for (i = 0, vma = mm->mmap, pos = 2; vma; 2139 vma = vma->vm_next) { 2140 if (!vma->vm_file) 2141 continue; 2142 if (++pos <= ctx->pos) 2143 continue; 2144 2145 info.mode = vma->vm_file->f_mode; 2146 info.len = snprintf(info.name, 2147 sizeof(info.name), "%lx-%lx", 2148 vma->vm_start, vma->vm_end); 2149 if (flex_array_put(fa, i++, &info, GFP_KERNEL)) 2150 BUG(); 2151 } 2152 } 2153 up_read(&mm->mmap_sem); 2154 2155 for (i = 0; i < nr_files; i++) { 2156 p = flex_array_get(fa, i); 2157 if (!proc_fill_cache(file, ctx, 2158 p->name, p->len, 2159 proc_map_files_instantiate, 2160 task, 2161 (void *)(unsigned long)p->mode)) 2162 break; 2163 ctx->pos++; 2164 } 2165 if (fa) 2166 flex_array_free(fa); 2167 mmput(mm); 2168 2169 out_put_task: 2170 put_task_struct(task); 2171 out: 2172 return ret; 2173 } 2174 2175 static const struct file_operations proc_map_files_operations = { 2176 .read = generic_read_dir, 2177 .iterate_shared = proc_map_files_readdir, 2178 .llseek = generic_file_llseek, 2179 }; 2180 2181 #ifdef CONFIG_CHECKPOINT_RESTORE 2182 struct timers_private { 2183 struct pid *pid; 2184 struct task_struct *task; 2185 struct sighand_struct *sighand; 2186 struct pid_namespace *ns; 2187 unsigned long flags; 2188 }; 2189 2190 static void *timers_start(struct seq_file *m, loff_t *pos) 2191 { 2192 struct timers_private *tp = m->private; 2193 2194 tp->task = get_pid_task(tp->pid, PIDTYPE_PID); 2195 if (!tp->task) 2196 return ERR_PTR(-ESRCH); 2197 2198 tp->sighand = lock_task_sighand(tp->task, &tp->flags); 2199 if (!tp->sighand) 2200 return ERR_PTR(-ESRCH); 2201 2202 return seq_list_start(&tp->task->signal->posix_timers, *pos); 2203 } 2204 2205 static void *timers_next(struct seq_file *m, void *v, loff_t *pos) 2206 { 2207 struct timers_private *tp = m->private; 2208 return seq_list_next(v, &tp->task->signal->posix_timers, pos); 2209 } 2210 2211 static void timers_stop(struct seq_file *m, void *v) 2212 { 2213 struct timers_private *tp = m->private; 2214 2215 if (tp->sighand) { 2216 unlock_task_sighand(tp->task, &tp->flags); 2217 tp->sighand = NULL; 2218 } 2219 2220 if (tp->task) { 2221 put_task_struct(tp->task); 2222 tp->task = NULL; 2223 } 2224 } 2225 2226 static int show_timer(struct seq_file *m, void *v) 2227 { 2228 struct k_itimer *timer; 2229 struct timers_private *tp = m->private; 2230 int notify; 2231 static const char * const nstr[] = { 2232 [SIGEV_SIGNAL] = "signal", 2233 [SIGEV_NONE] = "none", 2234 [SIGEV_THREAD] = "thread", 2235 }; 2236 2237 timer = list_entry((struct list_head *)v, struct k_itimer, list); 2238 notify = timer->it_sigev_notify; 2239 2240 seq_printf(m, "ID: %d\n", timer->it_id); 2241 seq_printf(m, "signal: %d/%p\n", 2242 timer->sigq->info.si_signo, 2243 timer->sigq->info.si_value.sival_ptr); 2244 seq_printf(m, "notify: %s/%s.%d\n", 2245 nstr[notify & ~SIGEV_THREAD_ID], 2246 (notify & SIGEV_THREAD_ID) ? "tid" : "pid", 2247 pid_nr_ns(timer->it_pid, tp->ns)); 2248 seq_printf(m, "ClockID: %d\n", timer->it_clock); 2249 2250 return 0; 2251 } 2252 2253 static const struct seq_operations proc_timers_seq_ops = { 2254 .start = timers_start, 2255 .next = timers_next, 2256 .stop = timers_stop, 2257 .show = show_timer, 2258 }; 2259 2260 static int proc_timers_open(struct inode *inode, struct file *file) 2261 { 2262 struct timers_private *tp; 2263 2264 tp = __seq_open_private(file, &proc_timers_seq_ops, 2265 sizeof(struct timers_private)); 2266 if (!tp) 2267 return -ENOMEM; 2268 2269 tp->pid = proc_pid(inode); 2270 tp->ns = inode->i_sb->s_fs_info; 2271 return 0; 2272 } 2273 2274 static const struct file_operations proc_timers_operations = { 2275 .open = proc_timers_open, 2276 .read = seq_read, 2277 .llseek = seq_lseek, 2278 .release = seq_release_private, 2279 }; 2280 #endif 2281 2282 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf, 2283 size_t count, loff_t *offset) 2284 { 2285 struct inode *inode = file_inode(file); 2286 struct task_struct *p; 2287 u64 slack_ns; 2288 int err; 2289 2290 err = kstrtoull_from_user(buf, count, 10, &slack_ns); 2291 if (err < 0) 2292 return err; 2293 2294 p = get_proc_task(inode); 2295 if (!p) 2296 return -ESRCH; 2297 2298 if (p != current) { 2299 if (!capable(CAP_SYS_NICE)) { 2300 count = -EPERM; 2301 goto out; 2302 } 2303 2304 err = security_task_setscheduler(p); 2305 if (err) { 2306 count = err; 2307 goto out; 2308 } 2309 } 2310 2311 task_lock(p); 2312 if (slack_ns == 0) 2313 p->timer_slack_ns = p->default_timer_slack_ns; 2314 else 2315 p->timer_slack_ns = slack_ns; 2316 task_unlock(p); 2317 2318 out: 2319 put_task_struct(p); 2320 2321 return count; 2322 } 2323 2324 static int timerslack_ns_show(struct seq_file *m, void *v) 2325 { 2326 struct inode *inode = m->private; 2327 struct task_struct *p; 2328 int err = 0; 2329 2330 p = get_proc_task(inode); 2331 if (!p) 2332 return -ESRCH; 2333 2334 if (p != current) { 2335 2336 if (!capable(CAP_SYS_NICE)) { 2337 err = -EPERM; 2338 goto out; 2339 } 2340 err = security_task_getscheduler(p); 2341 if (err) 2342 goto out; 2343 } 2344 2345 task_lock(p); 2346 seq_printf(m, "%llu\n", p->timer_slack_ns); 2347 task_unlock(p); 2348 2349 out: 2350 put_task_struct(p); 2351 2352 return err; 2353 } 2354 2355 static int timerslack_ns_open(struct inode *inode, struct file *filp) 2356 { 2357 return single_open(filp, timerslack_ns_show, inode); 2358 } 2359 2360 static const struct file_operations proc_pid_set_timerslack_ns_operations = { 2361 .open = timerslack_ns_open, 2362 .read = seq_read, 2363 .write = timerslack_ns_write, 2364 .llseek = seq_lseek, 2365 .release = single_release, 2366 }; 2367 2368 static int proc_pident_instantiate(struct inode *dir, 2369 struct dentry *dentry, struct task_struct *task, const void *ptr) 2370 { 2371 const struct pid_entry *p = ptr; 2372 struct inode *inode; 2373 struct proc_inode *ei; 2374 2375 inode = proc_pid_make_inode(dir->i_sb, task); 2376 if (!inode) 2377 goto out; 2378 2379 ei = PROC_I(inode); 2380 inode->i_mode = p->mode; 2381 if (S_ISDIR(inode->i_mode)) 2382 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2383 if (p->iop) 2384 inode->i_op = p->iop; 2385 if (p->fop) 2386 inode->i_fop = p->fop; 2387 ei->op = p->op; 2388 d_set_d_op(dentry, &pid_dentry_operations); 2389 d_add(dentry, inode); 2390 /* Close the race of the process dying before we return the dentry */ 2391 if (pid_revalidate(dentry, 0)) 2392 return 0; 2393 out: 2394 return -ENOENT; 2395 } 2396 2397 static struct dentry *proc_pident_lookup(struct inode *dir, 2398 struct dentry *dentry, 2399 const struct pid_entry *ents, 2400 unsigned int nents) 2401 { 2402 int error; 2403 struct task_struct *task = get_proc_task(dir); 2404 const struct pid_entry *p, *last; 2405 2406 error = -ENOENT; 2407 2408 if (!task) 2409 goto out_no_task; 2410 2411 /* 2412 * Yes, it does not scale. And it should not. Don't add 2413 * new entries into /proc/<tgid>/ without very good reasons. 2414 */ 2415 last = &ents[nents - 1]; 2416 for (p = ents; p <= last; p++) { 2417 if (p->len != dentry->d_name.len) 2418 continue; 2419 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2420 break; 2421 } 2422 if (p > last) 2423 goto out; 2424 2425 error = proc_pident_instantiate(dir, dentry, task, p); 2426 out: 2427 put_task_struct(task); 2428 out_no_task: 2429 return ERR_PTR(error); 2430 } 2431 2432 static int proc_pident_readdir(struct file *file, struct dir_context *ctx, 2433 const struct pid_entry *ents, unsigned int nents) 2434 { 2435 struct task_struct *task = get_proc_task(file_inode(file)); 2436 const struct pid_entry *p; 2437 2438 if (!task) 2439 return -ENOENT; 2440 2441 if (!dir_emit_dots(file, ctx)) 2442 goto out; 2443 2444 if (ctx->pos >= nents + 2) 2445 goto out; 2446 2447 for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) { 2448 if (!proc_fill_cache(file, ctx, p->name, p->len, 2449 proc_pident_instantiate, task, p)) 2450 break; 2451 ctx->pos++; 2452 } 2453 out: 2454 put_task_struct(task); 2455 return 0; 2456 } 2457 2458 #ifdef CONFIG_SECURITY 2459 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2460 size_t count, loff_t *ppos) 2461 { 2462 struct inode * inode = file_inode(file); 2463 char *p = NULL; 2464 ssize_t length; 2465 struct task_struct *task = get_proc_task(inode); 2466 2467 if (!task) 2468 return -ESRCH; 2469 2470 length = security_getprocattr(task, 2471 (char*)file->f_path.dentry->d_name.name, 2472 &p); 2473 put_task_struct(task); 2474 if (length > 0) 2475 length = simple_read_from_buffer(buf, count, ppos, p, length); 2476 kfree(p); 2477 return length; 2478 } 2479 2480 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2481 size_t count, loff_t *ppos) 2482 { 2483 struct inode * inode = file_inode(file); 2484 void *page; 2485 ssize_t length; 2486 struct task_struct *task = get_proc_task(inode); 2487 2488 length = -ESRCH; 2489 if (!task) 2490 goto out_no_task; 2491 if (count > PAGE_SIZE) 2492 count = PAGE_SIZE; 2493 2494 /* No partial writes. */ 2495 length = -EINVAL; 2496 if (*ppos != 0) 2497 goto out; 2498 2499 page = memdup_user(buf, count); 2500 if (IS_ERR(page)) { 2501 length = PTR_ERR(page); 2502 goto out; 2503 } 2504 2505 /* Guard against adverse ptrace interaction */ 2506 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex); 2507 if (length < 0) 2508 goto out_free; 2509 2510 length = security_setprocattr(task, 2511 (char*)file->f_path.dentry->d_name.name, 2512 page, count); 2513 mutex_unlock(&task->signal->cred_guard_mutex); 2514 out_free: 2515 kfree(page); 2516 out: 2517 put_task_struct(task); 2518 out_no_task: 2519 return length; 2520 } 2521 2522 static const struct file_operations proc_pid_attr_operations = { 2523 .read = proc_pid_attr_read, 2524 .write = proc_pid_attr_write, 2525 .llseek = generic_file_llseek, 2526 }; 2527 2528 static const struct pid_entry attr_dir_stuff[] = { 2529 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2530 REG("prev", S_IRUGO, proc_pid_attr_operations), 2531 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2532 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2533 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2534 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2535 }; 2536 2537 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx) 2538 { 2539 return proc_pident_readdir(file, ctx, 2540 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2541 } 2542 2543 static const struct file_operations proc_attr_dir_operations = { 2544 .read = generic_read_dir, 2545 .iterate_shared = proc_attr_dir_readdir, 2546 .llseek = generic_file_llseek, 2547 }; 2548 2549 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2550 struct dentry *dentry, unsigned int flags) 2551 { 2552 return proc_pident_lookup(dir, dentry, 2553 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2554 } 2555 2556 static const struct inode_operations proc_attr_dir_inode_operations = { 2557 .lookup = proc_attr_dir_lookup, 2558 .getattr = pid_getattr, 2559 .setattr = proc_setattr, 2560 }; 2561 2562 #endif 2563 2564 #ifdef CONFIG_ELF_CORE 2565 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2566 size_t count, loff_t *ppos) 2567 { 2568 struct task_struct *task = get_proc_task(file_inode(file)); 2569 struct mm_struct *mm; 2570 char buffer[PROC_NUMBUF]; 2571 size_t len; 2572 int ret; 2573 2574 if (!task) 2575 return -ESRCH; 2576 2577 ret = 0; 2578 mm = get_task_mm(task); 2579 if (mm) { 2580 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2581 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2582 MMF_DUMP_FILTER_SHIFT)); 2583 mmput(mm); 2584 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2585 } 2586 2587 put_task_struct(task); 2588 2589 return ret; 2590 } 2591 2592 static ssize_t proc_coredump_filter_write(struct file *file, 2593 const char __user *buf, 2594 size_t count, 2595 loff_t *ppos) 2596 { 2597 struct task_struct *task; 2598 struct mm_struct *mm; 2599 unsigned int val; 2600 int ret; 2601 int i; 2602 unsigned long mask; 2603 2604 ret = kstrtouint_from_user(buf, count, 0, &val); 2605 if (ret < 0) 2606 return ret; 2607 2608 ret = -ESRCH; 2609 task = get_proc_task(file_inode(file)); 2610 if (!task) 2611 goto out_no_task; 2612 2613 mm = get_task_mm(task); 2614 if (!mm) 2615 goto out_no_mm; 2616 ret = 0; 2617 2618 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2619 if (val & mask) 2620 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2621 else 2622 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2623 } 2624 2625 mmput(mm); 2626 out_no_mm: 2627 put_task_struct(task); 2628 out_no_task: 2629 if (ret < 0) 2630 return ret; 2631 return count; 2632 } 2633 2634 static const struct file_operations proc_coredump_filter_operations = { 2635 .read = proc_coredump_filter_read, 2636 .write = proc_coredump_filter_write, 2637 .llseek = generic_file_llseek, 2638 }; 2639 #endif 2640 2641 #ifdef CONFIG_TASK_IO_ACCOUNTING 2642 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole) 2643 { 2644 struct task_io_accounting acct = task->ioac; 2645 unsigned long flags; 2646 int result; 2647 2648 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2649 if (result) 2650 return result; 2651 2652 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { 2653 result = -EACCES; 2654 goto out_unlock; 2655 } 2656 2657 if (whole && lock_task_sighand(task, &flags)) { 2658 struct task_struct *t = task; 2659 2660 task_io_accounting_add(&acct, &task->signal->ioac); 2661 while_each_thread(task, t) 2662 task_io_accounting_add(&acct, &t->ioac); 2663 2664 unlock_task_sighand(task, &flags); 2665 } 2666 seq_printf(m, 2667 "rchar: %llu\n" 2668 "wchar: %llu\n" 2669 "syscr: %llu\n" 2670 "syscw: %llu\n" 2671 "read_bytes: %llu\n" 2672 "write_bytes: %llu\n" 2673 "cancelled_write_bytes: %llu\n", 2674 (unsigned long long)acct.rchar, 2675 (unsigned long long)acct.wchar, 2676 (unsigned long long)acct.syscr, 2677 (unsigned long long)acct.syscw, 2678 (unsigned long long)acct.read_bytes, 2679 (unsigned long long)acct.write_bytes, 2680 (unsigned long long)acct.cancelled_write_bytes); 2681 result = 0; 2682 2683 out_unlock: 2684 mutex_unlock(&task->signal->cred_guard_mutex); 2685 return result; 2686 } 2687 2688 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2689 struct pid *pid, struct task_struct *task) 2690 { 2691 return do_io_accounting(task, m, 0); 2692 } 2693 2694 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2695 struct pid *pid, struct task_struct *task) 2696 { 2697 return do_io_accounting(task, m, 1); 2698 } 2699 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2700 2701 #ifdef CONFIG_USER_NS 2702 static int proc_id_map_open(struct inode *inode, struct file *file, 2703 const struct seq_operations *seq_ops) 2704 { 2705 struct user_namespace *ns = NULL; 2706 struct task_struct *task; 2707 struct seq_file *seq; 2708 int ret = -EINVAL; 2709 2710 task = get_proc_task(inode); 2711 if (task) { 2712 rcu_read_lock(); 2713 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2714 rcu_read_unlock(); 2715 put_task_struct(task); 2716 } 2717 if (!ns) 2718 goto err; 2719 2720 ret = seq_open(file, seq_ops); 2721 if (ret) 2722 goto err_put_ns; 2723 2724 seq = file->private_data; 2725 seq->private = ns; 2726 2727 return 0; 2728 err_put_ns: 2729 put_user_ns(ns); 2730 err: 2731 return ret; 2732 } 2733 2734 static int proc_id_map_release(struct inode *inode, struct file *file) 2735 { 2736 struct seq_file *seq = file->private_data; 2737 struct user_namespace *ns = seq->private; 2738 put_user_ns(ns); 2739 return seq_release(inode, file); 2740 } 2741 2742 static int proc_uid_map_open(struct inode *inode, struct file *file) 2743 { 2744 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2745 } 2746 2747 static int proc_gid_map_open(struct inode *inode, struct file *file) 2748 { 2749 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2750 } 2751 2752 static int proc_projid_map_open(struct inode *inode, struct file *file) 2753 { 2754 return proc_id_map_open(inode, file, &proc_projid_seq_operations); 2755 } 2756 2757 static const struct file_operations proc_uid_map_operations = { 2758 .open = proc_uid_map_open, 2759 .write = proc_uid_map_write, 2760 .read = seq_read, 2761 .llseek = seq_lseek, 2762 .release = proc_id_map_release, 2763 }; 2764 2765 static const struct file_operations proc_gid_map_operations = { 2766 .open = proc_gid_map_open, 2767 .write = proc_gid_map_write, 2768 .read = seq_read, 2769 .llseek = seq_lseek, 2770 .release = proc_id_map_release, 2771 }; 2772 2773 static const struct file_operations proc_projid_map_operations = { 2774 .open = proc_projid_map_open, 2775 .write = proc_projid_map_write, 2776 .read = seq_read, 2777 .llseek = seq_lseek, 2778 .release = proc_id_map_release, 2779 }; 2780 2781 static int proc_setgroups_open(struct inode *inode, struct file *file) 2782 { 2783 struct user_namespace *ns = NULL; 2784 struct task_struct *task; 2785 int ret; 2786 2787 ret = -ESRCH; 2788 task = get_proc_task(inode); 2789 if (task) { 2790 rcu_read_lock(); 2791 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2792 rcu_read_unlock(); 2793 put_task_struct(task); 2794 } 2795 if (!ns) 2796 goto err; 2797 2798 if (file->f_mode & FMODE_WRITE) { 2799 ret = -EACCES; 2800 if (!ns_capable(ns, CAP_SYS_ADMIN)) 2801 goto err_put_ns; 2802 } 2803 2804 ret = single_open(file, &proc_setgroups_show, ns); 2805 if (ret) 2806 goto err_put_ns; 2807 2808 return 0; 2809 err_put_ns: 2810 put_user_ns(ns); 2811 err: 2812 return ret; 2813 } 2814 2815 static int proc_setgroups_release(struct inode *inode, struct file *file) 2816 { 2817 struct seq_file *seq = file->private_data; 2818 struct user_namespace *ns = seq->private; 2819 int ret = single_release(inode, file); 2820 put_user_ns(ns); 2821 return ret; 2822 } 2823 2824 static const struct file_operations proc_setgroups_operations = { 2825 .open = proc_setgroups_open, 2826 .write = proc_setgroups_write, 2827 .read = seq_read, 2828 .llseek = seq_lseek, 2829 .release = proc_setgroups_release, 2830 }; 2831 #endif /* CONFIG_USER_NS */ 2832 2833 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2834 struct pid *pid, struct task_struct *task) 2835 { 2836 int err = lock_trace(task); 2837 if (!err) { 2838 seq_printf(m, "%08x\n", task->personality); 2839 unlock_trace(task); 2840 } 2841 return err; 2842 } 2843 2844 /* 2845 * Thread groups 2846 */ 2847 static const struct file_operations proc_task_operations; 2848 static const struct inode_operations proc_task_inode_operations; 2849 2850 static const struct pid_entry tgid_base_stuff[] = { 2851 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2852 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2853 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 2854 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2855 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2856 #ifdef CONFIG_NET 2857 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2858 #endif 2859 REG("environ", S_IRUSR, proc_environ_operations), 2860 REG("auxv", S_IRUSR, proc_auxv_operations), 2861 ONE("status", S_IRUGO, proc_pid_status), 2862 ONE("personality", S_IRUSR, proc_pid_personality), 2863 ONE("limits", S_IRUGO, proc_pid_limits), 2864 #ifdef CONFIG_SCHED_DEBUG 2865 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2866 #endif 2867 #ifdef CONFIG_SCHED_AUTOGROUP 2868 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2869 #endif 2870 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2871 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2872 ONE("syscall", S_IRUSR, proc_pid_syscall), 2873 #endif 2874 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 2875 ONE("stat", S_IRUGO, proc_tgid_stat), 2876 ONE("statm", S_IRUGO, proc_pid_statm), 2877 REG("maps", S_IRUGO, proc_pid_maps_operations), 2878 #ifdef CONFIG_NUMA 2879 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 2880 #endif 2881 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2882 LNK("cwd", proc_cwd_link), 2883 LNK("root", proc_root_link), 2884 LNK("exe", proc_exe_link), 2885 REG("mounts", S_IRUGO, proc_mounts_operations), 2886 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2887 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2888 #ifdef CONFIG_PROC_PAGE_MONITOR 2889 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2890 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 2891 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2892 #endif 2893 #ifdef CONFIG_SECURITY 2894 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2895 #endif 2896 #ifdef CONFIG_KALLSYMS 2897 ONE("wchan", S_IRUGO, proc_pid_wchan), 2898 #endif 2899 #ifdef CONFIG_STACKTRACE 2900 ONE("stack", S_IRUSR, proc_pid_stack), 2901 #endif 2902 #ifdef CONFIG_SCHED_INFO 2903 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 2904 #endif 2905 #ifdef CONFIG_LATENCYTOP 2906 REG("latency", S_IRUGO, proc_lstats_operations), 2907 #endif 2908 #ifdef CONFIG_PROC_PID_CPUSET 2909 ONE("cpuset", S_IRUGO, proc_cpuset_show), 2910 #endif 2911 #ifdef CONFIG_CGROUPS 2912 ONE("cgroup", S_IRUGO, proc_cgroup_show), 2913 #endif 2914 ONE("oom_score", S_IRUGO, proc_oom_score), 2915 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 2916 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2917 #ifdef CONFIG_AUDITSYSCALL 2918 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2919 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2920 #endif 2921 #ifdef CONFIG_FAULT_INJECTION 2922 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2923 #endif 2924 #ifdef CONFIG_ELF_CORE 2925 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2926 #endif 2927 #ifdef CONFIG_TASK_IO_ACCOUNTING 2928 ONE("io", S_IRUSR, proc_tgid_io_accounting), 2929 #endif 2930 #ifdef CONFIG_HARDWALL 2931 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 2932 #endif 2933 #ifdef CONFIG_USER_NS 2934 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 2935 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 2936 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 2937 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 2938 #endif 2939 #ifdef CONFIG_CHECKPOINT_RESTORE 2940 REG("timers", S_IRUGO, proc_timers_operations), 2941 #endif 2942 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations), 2943 }; 2944 2945 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) 2946 { 2947 return proc_pident_readdir(file, ctx, 2948 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2949 } 2950 2951 static const struct file_operations proc_tgid_base_operations = { 2952 .read = generic_read_dir, 2953 .iterate_shared = proc_tgid_base_readdir, 2954 .llseek = generic_file_llseek, 2955 }; 2956 2957 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 2958 { 2959 return proc_pident_lookup(dir, dentry, 2960 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2961 } 2962 2963 static const struct inode_operations proc_tgid_base_inode_operations = { 2964 .lookup = proc_tgid_base_lookup, 2965 .getattr = pid_getattr, 2966 .setattr = proc_setattr, 2967 .permission = proc_pid_permission, 2968 }; 2969 2970 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2971 { 2972 struct dentry *dentry, *leader, *dir; 2973 char buf[PROC_NUMBUF]; 2974 struct qstr name; 2975 2976 name.name = buf; 2977 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2978 /* no ->d_hash() rejects on procfs */ 2979 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2980 if (dentry) { 2981 d_invalidate(dentry); 2982 dput(dentry); 2983 } 2984 2985 if (pid == tgid) 2986 return; 2987 2988 name.name = buf; 2989 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2990 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2991 if (!leader) 2992 goto out; 2993 2994 name.name = "task"; 2995 name.len = strlen(name.name); 2996 dir = d_hash_and_lookup(leader, &name); 2997 if (!dir) 2998 goto out_put_leader; 2999 3000 name.name = buf; 3001 name.len = snprintf(buf, sizeof(buf), "%d", pid); 3002 dentry = d_hash_and_lookup(dir, &name); 3003 if (dentry) { 3004 d_invalidate(dentry); 3005 dput(dentry); 3006 } 3007 3008 dput(dir); 3009 out_put_leader: 3010 dput(leader); 3011 out: 3012 return; 3013 } 3014 3015 /** 3016 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 3017 * @task: task that should be flushed. 3018 * 3019 * When flushing dentries from proc, one needs to flush them from global 3020 * proc (proc_mnt) and from all the namespaces' procs this task was seen 3021 * in. This call is supposed to do all of this job. 3022 * 3023 * Looks in the dcache for 3024 * /proc/@pid 3025 * /proc/@tgid/task/@pid 3026 * if either directory is present flushes it and all of it'ts children 3027 * from the dcache. 3028 * 3029 * It is safe and reasonable to cache /proc entries for a task until 3030 * that task exits. After that they just clog up the dcache with 3031 * useless entries, possibly causing useful dcache entries to be 3032 * flushed instead. This routine is proved to flush those useless 3033 * dcache entries at process exit time. 3034 * 3035 * NOTE: This routine is just an optimization so it does not guarantee 3036 * that no dcache entries will exist at process exit time it 3037 * just makes it very unlikely that any will persist. 3038 */ 3039 3040 void proc_flush_task(struct task_struct *task) 3041 { 3042 int i; 3043 struct pid *pid, *tgid; 3044 struct upid *upid; 3045 3046 pid = task_pid(task); 3047 tgid = task_tgid(task); 3048 3049 for (i = 0; i <= pid->level; i++) { 3050 upid = &pid->numbers[i]; 3051 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3052 tgid->numbers[i].nr); 3053 } 3054 } 3055 3056 static int proc_pid_instantiate(struct inode *dir, 3057 struct dentry * dentry, 3058 struct task_struct *task, const void *ptr) 3059 { 3060 struct inode *inode; 3061 3062 inode = proc_pid_make_inode(dir->i_sb, task); 3063 if (!inode) 3064 goto out; 3065 3066 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3067 inode->i_op = &proc_tgid_base_inode_operations; 3068 inode->i_fop = &proc_tgid_base_operations; 3069 inode->i_flags|=S_IMMUTABLE; 3070 3071 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff, 3072 ARRAY_SIZE(tgid_base_stuff))); 3073 3074 d_set_d_op(dentry, &pid_dentry_operations); 3075 3076 d_add(dentry, inode); 3077 /* Close the race of the process dying before we return the dentry */ 3078 if (pid_revalidate(dentry, 0)) 3079 return 0; 3080 out: 3081 return -ENOENT; 3082 } 3083 3084 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3085 { 3086 int result = -ENOENT; 3087 struct task_struct *task; 3088 unsigned tgid; 3089 struct pid_namespace *ns; 3090 3091 tgid = name_to_int(&dentry->d_name); 3092 if (tgid == ~0U) 3093 goto out; 3094 3095 ns = dentry->d_sb->s_fs_info; 3096 rcu_read_lock(); 3097 task = find_task_by_pid_ns(tgid, ns); 3098 if (task) 3099 get_task_struct(task); 3100 rcu_read_unlock(); 3101 if (!task) 3102 goto out; 3103 3104 result = proc_pid_instantiate(dir, dentry, task, NULL); 3105 put_task_struct(task); 3106 out: 3107 return ERR_PTR(result); 3108 } 3109 3110 /* 3111 * Find the first task with tgid >= tgid 3112 * 3113 */ 3114 struct tgid_iter { 3115 unsigned int tgid; 3116 struct task_struct *task; 3117 }; 3118 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3119 { 3120 struct pid *pid; 3121 3122 if (iter.task) 3123 put_task_struct(iter.task); 3124 rcu_read_lock(); 3125 retry: 3126 iter.task = NULL; 3127 pid = find_ge_pid(iter.tgid, ns); 3128 if (pid) { 3129 iter.tgid = pid_nr_ns(pid, ns); 3130 iter.task = pid_task(pid, PIDTYPE_PID); 3131 /* What we to know is if the pid we have find is the 3132 * pid of a thread_group_leader. Testing for task 3133 * being a thread_group_leader is the obvious thing 3134 * todo but there is a window when it fails, due to 3135 * the pid transfer logic in de_thread. 3136 * 3137 * So we perform the straight forward test of seeing 3138 * if the pid we have found is the pid of a thread 3139 * group leader, and don't worry if the task we have 3140 * found doesn't happen to be a thread group leader. 3141 * As we don't care in the case of readdir. 3142 */ 3143 if (!iter.task || !has_group_leader_pid(iter.task)) { 3144 iter.tgid += 1; 3145 goto retry; 3146 } 3147 get_task_struct(iter.task); 3148 } 3149 rcu_read_unlock(); 3150 return iter; 3151 } 3152 3153 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2) 3154 3155 /* for the /proc/ directory itself, after non-process stuff has been done */ 3156 int proc_pid_readdir(struct file *file, struct dir_context *ctx) 3157 { 3158 struct tgid_iter iter; 3159 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info; 3160 loff_t pos = ctx->pos; 3161 3162 if (pos >= PID_MAX_LIMIT + TGID_OFFSET) 3163 return 0; 3164 3165 if (pos == TGID_OFFSET - 2) { 3166 struct inode *inode = d_inode(ns->proc_self); 3167 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) 3168 return 0; 3169 ctx->pos = pos = pos + 1; 3170 } 3171 if (pos == TGID_OFFSET - 1) { 3172 struct inode *inode = d_inode(ns->proc_thread_self); 3173 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) 3174 return 0; 3175 ctx->pos = pos = pos + 1; 3176 } 3177 iter.tgid = pos - TGID_OFFSET; 3178 iter.task = NULL; 3179 for (iter = next_tgid(ns, iter); 3180 iter.task; 3181 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3182 char name[PROC_NUMBUF]; 3183 int len; 3184 if (!has_pid_permissions(ns, iter.task, 2)) 3185 continue; 3186 3187 len = snprintf(name, sizeof(name), "%d", iter.tgid); 3188 ctx->pos = iter.tgid + TGID_OFFSET; 3189 if (!proc_fill_cache(file, ctx, name, len, 3190 proc_pid_instantiate, iter.task, NULL)) { 3191 put_task_struct(iter.task); 3192 return 0; 3193 } 3194 } 3195 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET; 3196 return 0; 3197 } 3198 3199 /* 3200 * proc_tid_comm_permission is a special permission function exclusively 3201 * used for the node /proc/<pid>/task/<tid>/comm. 3202 * It bypasses generic permission checks in the case where a task of the same 3203 * task group attempts to access the node. 3204 * The rationale behind this is that glibc and bionic access this node for 3205 * cross thread naming (pthread_set/getname_np(!self)). However, if 3206 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0, 3207 * which locks out the cross thread naming implementation. 3208 * This function makes sure that the node is always accessible for members of 3209 * same thread group. 3210 */ 3211 static int proc_tid_comm_permission(struct inode *inode, int mask) 3212 { 3213 bool is_same_tgroup; 3214 struct task_struct *task; 3215 3216 task = get_proc_task(inode); 3217 if (!task) 3218 return -ESRCH; 3219 is_same_tgroup = same_thread_group(current, task); 3220 put_task_struct(task); 3221 3222 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) { 3223 /* This file (/proc/<pid>/task/<tid>/comm) can always be 3224 * read or written by the members of the corresponding 3225 * thread group. 3226 */ 3227 return 0; 3228 } 3229 3230 return generic_permission(inode, mask); 3231 } 3232 3233 static const struct inode_operations proc_tid_comm_inode_operations = { 3234 .permission = proc_tid_comm_permission, 3235 }; 3236 3237 /* 3238 * Tasks 3239 */ 3240 static const struct pid_entry tid_base_stuff[] = { 3241 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3242 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3243 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3244 #ifdef CONFIG_NET 3245 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3246 #endif 3247 REG("environ", S_IRUSR, proc_environ_operations), 3248 REG("auxv", S_IRUSR, proc_auxv_operations), 3249 ONE("status", S_IRUGO, proc_pid_status), 3250 ONE("personality", S_IRUSR, proc_pid_personality), 3251 ONE("limits", S_IRUGO, proc_pid_limits), 3252 #ifdef CONFIG_SCHED_DEBUG 3253 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3254 #endif 3255 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR, 3256 &proc_tid_comm_inode_operations, 3257 &proc_pid_set_comm_operations, {}), 3258 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3259 ONE("syscall", S_IRUSR, proc_pid_syscall), 3260 #endif 3261 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 3262 ONE("stat", S_IRUGO, proc_tid_stat), 3263 ONE("statm", S_IRUGO, proc_pid_statm), 3264 REG("maps", S_IRUGO, proc_tid_maps_operations), 3265 #ifdef CONFIG_PROC_CHILDREN 3266 REG("children", S_IRUGO, proc_tid_children_operations), 3267 #endif 3268 #ifdef CONFIG_NUMA 3269 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations), 3270 #endif 3271 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3272 LNK("cwd", proc_cwd_link), 3273 LNK("root", proc_root_link), 3274 LNK("exe", proc_exe_link), 3275 REG("mounts", S_IRUGO, proc_mounts_operations), 3276 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3277 #ifdef CONFIG_PROC_PAGE_MONITOR 3278 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3279 REG("smaps", S_IRUGO, proc_tid_smaps_operations), 3280 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3281 #endif 3282 #ifdef CONFIG_SECURITY 3283 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3284 #endif 3285 #ifdef CONFIG_KALLSYMS 3286 ONE("wchan", S_IRUGO, proc_pid_wchan), 3287 #endif 3288 #ifdef CONFIG_STACKTRACE 3289 ONE("stack", S_IRUSR, proc_pid_stack), 3290 #endif 3291 #ifdef CONFIG_SCHED_INFO 3292 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 3293 #endif 3294 #ifdef CONFIG_LATENCYTOP 3295 REG("latency", S_IRUGO, proc_lstats_operations), 3296 #endif 3297 #ifdef CONFIG_PROC_PID_CPUSET 3298 ONE("cpuset", S_IRUGO, proc_cpuset_show), 3299 #endif 3300 #ifdef CONFIG_CGROUPS 3301 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3302 #endif 3303 ONE("oom_score", S_IRUGO, proc_oom_score), 3304 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3305 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3306 #ifdef CONFIG_AUDITSYSCALL 3307 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3308 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3309 #endif 3310 #ifdef CONFIG_FAULT_INJECTION 3311 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3312 #endif 3313 #ifdef CONFIG_TASK_IO_ACCOUNTING 3314 ONE("io", S_IRUSR, proc_tid_io_accounting), 3315 #endif 3316 #ifdef CONFIG_HARDWALL 3317 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 3318 #endif 3319 #ifdef CONFIG_USER_NS 3320 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3321 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3322 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3323 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3324 #endif 3325 }; 3326 3327 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx) 3328 { 3329 return proc_pident_readdir(file, ctx, 3330 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3331 } 3332 3333 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3334 { 3335 return proc_pident_lookup(dir, dentry, 3336 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3337 } 3338 3339 static const struct file_operations proc_tid_base_operations = { 3340 .read = generic_read_dir, 3341 .iterate_shared = proc_tid_base_readdir, 3342 .llseek = generic_file_llseek, 3343 }; 3344 3345 static const struct inode_operations proc_tid_base_inode_operations = { 3346 .lookup = proc_tid_base_lookup, 3347 .getattr = pid_getattr, 3348 .setattr = proc_setattr, 3349 }; 3350 3351 static int proc_task_instantiate(struct inode *dir, 3352 struct dentry *dentry, struct task_struct *task, const void *ptr) 3353 { 3354 struct inode *inode; 3355 inode = proc_pid_make_inode(dir->i_sb, task); 3356 3357 if (!inode) 3358 goto out; 3359 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3360 inode->i_op = &proc_tid_base_inode_operations; 3361 inode->i_fop = &proc_tid_base_operations; 3362 inode->i_flags|=S_IMMUTABLE; 3363 3364 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff, 3365 ARRAY_SIZE(tid_base_stuff))); 3366 3367 d_set_d_op(dentry, &pid_dentry_operations); 3368 3369 d_add(dentry, inode); 3370 /* Close the race of the process dying before we return the dentry */ 3371 if (pid_revalidate(dentry, 0)) 3372 return 0; 3373 out: 3374 return -ENOENT; 3375 } 3376 3377 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3378 { 3379 int result = -ENOENT; 3380 struct task_struct *task; 3381 struct task_struct *leader = get_proc_task(dir); 3382 unsigned tid; 3383 struct pid_namespace *ns; 3384 3385 if (!leader) 3386 goto out_no_task; 3387 3388 tid = name_to_int(&dentry->d_name); 3389 if (tid == ~0U) 3390 goto out; 3391 3392 ns = dentry->d_sb->s_fs_info; 3393 rcu_read_lock(); 3394 task = find_task_by_pid_ns(tid, ns); 3395 if (task) 3396 get_task_struct(task); 3397 rcu_read_unlock(); 3398 if (!task) 3399 goto out; 3400 if (!same_thread_group(leader, task)) 3401 goto out_drop_task; 3402 3403 result = proc_task_instantiate(dir, dentry, task, NULL); 3404 out_drop_task: 3405 put_task_struct(task); 3406 out: 3407 put_task_struct(leader); 3408 out_no_task: 3409 return ERR_PTR(result); 3410 } 3411 3412 /* 3413 * Find the first tid of a thread group to return to user space. 3414 * 3415 * Usually this is just the thread group leader, but if the users 3416 * buffer was too small or there was a seek into the middle of the 3417 * directory we have more work todo. 3418 * 3419 * In the case of a short read we start with find_task_by_pid. 3420 * 3421 * In the case of a seek we start with the leader and walk nr 3422 * threads past it. 3423 */ 3424 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos, 3425 struct pid_namespace *ns) 3426 { 3427 struct task_struct *pos, *task; 3428 unsigned long nr = f_pos; 3429 3430 if (nr != f_pos) /* 32bit overflow? */ 3431 return NULL; 3432 3433 rcu_read_lock(); 3434 task = pid_task(pid, PIDTYPE_PID); 3435 if (!task) 3436 goto fail; 3437 3438 /* Attempt to start with the tid of a thread */ 3439 if (tid && nr) { 3440 pos = find_task_by_pid_ns(tid, ns); 3441 if (pos && same_thread_group(pos, task)) 3442 goto found; 3443 } 3444 3445 /* If nr exceeds the number of threads there is nothing todo */ 3446 if (nr >= get_nr_threads(task)) 3447 goto fail; 3448 3449 /* If we haven't found our starting place yet start 3450 * with the leader and walk nr threads forward. 3451 */ 3452 pos = task = task->group_leader; 3453 do { 3454 if (!nr--) 3455 goto found; 3456 } while_each_thread(task, pos); 3457 fail: 3458 pos = NULL; 3459 goto out; 3460 found: 3461 get_task_struct(pos); 3462 out: 3463 rcu_read_unlock(); 3464 return pos; 3465 } 3466 3467 /* 3468 * Find the next thread in the thread list. 3469 * Return NULL if there is an error or no next thread. 3470 * 3471 * The reference to the input task_struct is released. 3472 */ 3473 static struct task_struct *next_tid(struct task_struct *start) 3474 { 3475 struct task_struct *pos = NULL; 3476 rcu_read_lock(); 3477 if (pid_alive(start)) { 3478 pos = next_thread(start); 3479 if (thread_group_leader(pos)) 3480 pos = NULL; 3481 else 3482 get_task_struct(pos); 3483 } 3484 rcu_read_unlock(); 3485 put_task_struct(start); 3486 return pos; 3487 } 3488 3489 /* for the /proc/TGID/task/ directories */ 3490 static int proc_task_readdir(struct file *file, struct dir_context *ctx) 3491 { 3492 struct inode *inode = file_inode(file); 3493 struct task_struct *task; 3494 struct pid_namespace *ns; 3495 int tid; 3496 3497 if (proc_inode_is_dead(inode)) 3498 return -ENOENT; 3499 3500 if (!dir_emit_dots(file, ctx)) 3501 return 0; 3502 3503 /* f_version caches the tgid value that the last readdir call couldn't 3504 * return. lseek aka telldir automagically resets f_version to 0. 3505 */ 3506 ns = inode->i_sb->s_fs_info; 3507 tid = (int)file->f_version; 3508 file->f_version = 0; 3509 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); 3510 task; 3511 task = next_tid(task), ctx->pos++) { 3512 char name[PROC_NUMBUF]; 3513 int len; 3514 tid = task_pid_nr_ns(task, ns); 3515 len = snprintf(name, sizeof(name), "%d", tid); 3516 if (!proc_fill_cache(file, ctx, name, len, 3517 proc_task_instantiate, task, NULL)) { 3518 /* returning this tgid failed, save it as the first 3519 * pid for the next readir call */ 3520 file->f_version = (u64)tid; 3521 put_task_struct(task); 3522 break; 3523 } 3524 } 3525 3526 return 0; 3527 } 3528 3529 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3530 { 3531 struct inode *inode = d_inode(dentry); 3532 struct task_struct *p = get_proc_task(inode); 3533 generic_fillattr(inode, stat); 3534 3535 if (p) { 3536 stat->nlink += get_nr_threads(p); 3537 put_task_struct(p); 3538 } 3539 3540 return 0; 3541 } 3542 3543 static const struct inode_operations proc_task_inode_operations = { 3544 .lookup = proc_task_lookup, 3545 .getattr = proc_task_getattr, 3546 .setattr = proc_setattr, 3547 .permission = proc_pid_permission, 3548 }; 3549 3550 static const struct file_operations proc_task_operations = { 3551 .read = generic_read_dir, 3552 .iterate_shared = proc_task_readdir, 3553 .llseek = generic_file_llseek, 3554 }; 3555