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