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 <linux/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 static u8 nlink_tid; 108 static u8 nlink_tgid; 109 110 struct pid_entry { 111 const char *name; 112 unsigned int len; 113 umode_t mode; 114 const struct inode_operations *iop; 115 const struct file_operations *fop; 116 union proc_op op; 117 }; 118 119 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 120 .name = (NAME), \ 121 .len = sizeof(NAME) - 1, \ 122 .mode = MODE, \ 123 .iop = IOP, \ 124 .fop = FOP, \ 125 .op = OP, \ 126 } 127 128 #define DIR(NAME, MODE, iops, fops) \ 129 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} ) 130 #define LNK(NAME, get_link) \ 131 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 132 &proc_pid_link_inode_operations, NULL, \ 133 { .proc_get_link = get_link } ) 134 #define REG(NAME, MODE, fops) \ 135 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {}) 136 #define ONE(NAME, MODE, show) \ 137 NOD(NAME, (S_IFREG|(MODE)), \ 138 NULL, &proc_single_file_operations, \ 139 { .proc_show = show } ) 140 141 /* 142 * Count the number of hardlinks for the pid_entry table, excluding the . 143 * and .. links. 144 */ 145 static unsigned int __init pid_entry_nlink(const struct pid_entry *entries, 146 unsigned int n) 147 { 148 unsigned int i; 149 unsigned int count; 150 151 count = 2; 152 for (i = 0; i < n; ++i) { 153 if (S_ISDIR(entries[i].mode)) 154 ++count; 155 } 156 157 return count; 158 } 159 160 static int get_task_root(struct task_struct *task, struct path *root) 161 { 162 int result = -ENOENT; 163 164 task_lock(task); 165 if (task->fs) { 166 get_fs_root(task->fs, root); 167 result = 0; 168 } 169 task_unlock(task); 170 return result; 171 } 172 173 static int proc_cwd_link(struct dentry *dentry, struct path *path) 174 { 175 struct task_struct *task = get_proc_task(d_inode(dentry)); 176 int result = -ENOENT; 177 178 if (task) { 179 task_lock(task); 180 if (task->fs) { 181 get_fs_pwd(task->fs, path); 182 result = 0; 183 } 184 task_unlock(task); 185 put_task_struct(task); 186 } 187 return result; 188 } 189 190 static int proc_root_link(struct dentry *dentry, struct path *path) 191 { 192 struct task_struct *task = get_proc_task(d_inode(dentry)); 193 int result = -ENOENT; 194 195 if (task) { 196 result = get_task_root(task, path); 197 put_task_struct(task); 198 } 199 return result; 200 } 201 202 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, 203 size_t _count, loff_t *pos) 204 { 205 struct task_struct *tsk; 206 struct mm_struct *mm; 207 char *page; 208 unsigned long count = _count; 209 unsigned long arg_start, arg_end, env_start, env_end; 210 unsigned long len1, len2, len; 211 unsigned long p; 212 char c; 213 ssize_t rv; 214 215 BUG_ON(*pos < 0); 216 217 tsk = get_proc_task(file_inode(file)); 218 if (!tsk) 219 return -ESRCH; 220 mm = get_task_mm(tsk); 221 put_task_struct(tsk); 222 if (!mm) 223 return 0; 224 /* Check if process spawned far enough to have cmdline. */ 225 if (!mm->env_end) { 226 rv = 0; 227 goto out_mmput; 228 } 229 230 page = (char *)__get_free_page(GFP_TEMPORARY); 231 if (!page) { 232 rv = -ENOMEM; 233 goto out_mmput; 234 } 235 236 down_read(&mm->mmap_sem); 237 arg_start = mm->arg_start; 238 arg_end = mm->arg_end; 239 env_start = mm->env_start; 240 env_end = mm->env_end; 241 up_read(&mm->mmap_sem); 242 243 BUG_ON(arg_start > arg_end); 244 BUG_ON(env_start > env_end); 245 246 len1 = arg_end - arg_start; 247 len2 = env_end - env_start; 248 249 /* Empty ARGV. */ 250 if (len1 == 0) { 251 rv = 0; 252 goto out_free_page; 253 } 254 /* 255 * Inherently racy -- command line shares address space 256 * with code and data. 257 */ 258 rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0); 259 if (rv <= 0) 260 goto out_free_page; 261 262 rv = 0; 263 264 if (c == '\0') { 265 /* Command line (set of strings) occupies whole ARGV. */ 266 if (len1 <= *pos) 267 goto out_free_page; 268 269 p = arg_start + *pos; 270 len = len1 - *pos; 271 while (count > 0 && len > 0) { 272 unsigned int _count; 273 int nr_read; 274 275 _count = min3(count, len, PAGE_SIZE); 276 nr_read = access_remote_vm(mm, p, page, _count, 0); 277 if (nr_read < 0) 278 rv = nr_read; 279 if (nr_read <= 0) 280 goto out_free_page; 281 282 if (copy_to_user(buf, page, nr_read)) { 283 rv = -EFAULT; 284 goto out_free_page; 285 } 286 287 p += nr_read; 288 len -= nr_read; 289 buf += nr_read; 290 count -= nr_read; 291 rv += nr_read; 292 } 293 } else { 294 /* 295 * Command line (1 string) occupies ARGV and maybe 296 * extends into ENVP. 297 */ 298 if (len1 + len2 <= *pos) 299 goto skip_argv_envp; 300 if (len1 <= *pos) 301 goto skip_argv; 302 303 p = arg_start + *pos; 304 len = len1 - *pos; 305 while (count > 0 && len > 0) { 306 unsigned int _count, l; 307 int nr_read; 308 bool final; 309 310 _count = min3(count, len, PAGE_SIZE); 311 nr_read = access_remote_vm(mm, p, page, _count, 0); 312 if (nr_read < 0) 313 rv = nr_read; 314 if (nr_read <= 0) 315 goto out_free_page; 316 317 /* 318 * Command line can be shorter than whole ARGV 319 * even if last "marker" byte says it is not. 320 */ 321 final = false; 322 l = strnlen(page, nr_read); 323 if (l < nr_read) { 324 nr_read = l; 325 final = true; 326 } 327 328 if (copy_to_user(buf, page, nr_read)) { 329 rv = -EFAULT; 330 goto out_free_page; 331 } 332 333 p += nr_read; 334 len -= nr_read; 335 buf += nr_read; 336 count -= nr_read; 337 rv += nr_read; 338 339 if (final) 340 goto out_free_page; 341 } 342 skip_argv: 343 /* 344 * Command line (1 string) occupies ARGV and 345 * extends into ENVP. 346 */ 347 if (len1 <= *pos) { 348 p = env_start + *pos - len1; 349 len = len1 + len2 - *pos; 350 } else { 351 p = env_start; 352 len = len2; 353 } 354 while (count > 0 && len > 0) { 355 unsigned int _count, l; 356 int nr_read; 357 bool final; 358 359 _count = min3(count, len, PAGE_SIZE); 360 nr_read = access_remote_vm(mm, p, page, _count, 0); 361 if (nr_read < 0) 362 rv = nr_read; 363 if (nr_read <= 0) 364 goto out_free_page; 365 366 /* Find EOS. */ 367 final = false; 368 l = strnlen(page, nr_read); 369 if (l < nr_read) { 370 nr_read = l; 371 final = true; 372 } 373 374 if (copy_to_user(buf, page, nr_read)) { 375 rv = -EFAULT; 376 goto out_free_page; 377 } 378 379 p += nr_read; 380 len -= nr_read; 381 buf += nr_read; 382 count -= nr_read; 383 rv += nr_read; 384 385 if (final) 386 goto out_free_page; 387 } 388 skip_argv_envp: 389 ; 390 } 391 392 out_free_page: 393 free_page((unsigned long)page); 394 out_mmput: 395 mmput(mm); 396 if (rv > 0) 397 *pos += rv; 398 return rv; 399 } 400 401 static const struct file_operations proc_pid_cmdline_ops = { 402 .read = proc_pid_cmdline_read, 403 .llseek = generic_file_llseek, 404 }; 405 406 #ifdef CONFIG_KALLSYMS 407 /* 408 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 409 * Returns the resolved symbol. If that fails, simply return the address. 410 */ 411 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns, 412 struct pid *pid, struct task_struct *task) 413 { 414 unsigned long wchan; 415 char symname[KSYM_NAME_LEN]; 416 417 wchan = get_wchan(task); 418 419 if (wchan && ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS) 420 && !lookup_symbol_name(wchan, symname)) 421 seq_printf(m, "%s", symname); 422 else 423 seq_putc(m, '0'); 424 425 return 0; 426 } 427 #endif /* CONFIG_KALLSYMS */ 428 429 static int lock_trace(struct task_struct *task) 430 { 431 int err = mutex_lock_killable(&task->signal->cred_guard_mutex); 432 if (err) 433 return err; 434 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) { 435 mutex_unlock(&task->signal->cred_guard_mutex); 436 return -EPERM; 437 } 438 return 0; 439 } 440 441 static void unlock_trace(struct task_struct *task) 442 { 443 mutex_unlock(&task->signal->cred_guard_mutex); 444 } 445 446 #ifdef CONFIG_STACKTRACE 447 448 #define MAX_STACK_TRACE_DEPTH 64 449 450 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, 451 struct pid *pid, struct task_struct *task) 452 { 453 struct stack_trace trace; 454 unsigned long *entries; 455 int err; 456 int i; 457 458 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL); 459 if (!entries) 460 return -ENOMEM; 461 462 trace.nr_entries = 0; 463 trace.max_entries = MAX_STACK_TRACE_DEPTH; 464 trace.entries = entries; 465 trace.skip = 0; 466 467 err = lock_trace(task); 468 if (!err) { 469 save_stack_trace_tsk(task, &trace); 470 471 for (i = 0; i < trace.nr_entries; i++) { 472 seq_printf(m, "[<%pK>] %pB\n", 473 (void *)entries[i], (void *)entries[i]); 474 } 475 unlock_trace(task); 476 } 477 kfree(entries); 478 479 return err; 480 } 481 #endif 482 483 #ifdef CONFIG_SCHED_INFO 484 /* 485 * Provides /proc/PID/schedstat 486 */ 487 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, 488 struct pid *pid, struct task_struct *task) 489 { 490 if (unlikely(!sched_info_on())) 491 seq_printf(m, "0 0 0\n"); 492 else 493 seq_printf(m, "%llu %llu %lu\n", 494 (unsigned long long)task->se.sum_exec_runtime, 495 (unsigned long long)task->sched_info.run_delay, 496 task->sched_info.pcount); 497 498 return 0; 499 } 500 #endif 501 502 #ifdef CONFIG_LATENCYTOP 503 static int lstats_show_proc(struct seq_file *m, void *v) 504 { 505 int i; 506 struct inode *inode = m->private; 507 struct task_struct *task = get_proc_task(inode); 508 509 if (!task) 510 return -ESRCH; 511 seq_puts(m, "Latency Top version : v0.1\n"); 512 for (i = 0; i < 32; i++) { 513 struct latency_record *lr = &task->latency_record[i]; 514 if (lr->backtrace[0]) { 515 int q; 516 seq_printf(m, "%i %li %li", 517 lr->count, lr->time, lr->max); 518 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 519 unsigned long bt = lr->backtrace[q]; 520 if (!bt) 521 break; 522 if (bt == ULONG_MAX) 523 break; 524 seq_printf(m, " %ps", (void *)bt); 525 } 526 seq_putc(m, '\n'); 527 } 528 529 } 530 put_task_struct(task); 531 return 0; 532 } 533 534 static int lstats_open(struct inode *inode, struct file *file) 535 { 536 return single_open(file, lstats_show_proc, inode); 537 } 538 539 static ssize_t lstats_write(struct file *file, const char __user *buf, 540 size_t count, loff_t *offs) 541 { 542 struct task_struct *task = get_proc_task(file_inode(file)); 543 544 if (!task) 545 return -ESRCH; 546 clear_all_latency_tracing(task); 547 put_task_struct(task); 548 549 return count; 550 } 551 552 static const struct file_operations proc_lstats_operations = { 553 .open = lstats_open, 554 .read = seq_read, 555 .write = lstats_write, 556 .llseek = seq_lseek, 557 .release = single_release, 558 }; 559 560 #endif 561 562 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns, 563 struct pid *pid, struct task_struct *task) 564 { 565 unsigned long totalpages = totalram_pages + total_swap_pages; 566 unsigned long points = 0; 567 568 points = oom_badness(task, NULL, NULL, totalpages) * 569 1000 / totalpages; 570 seq_printf(m, "%lu\n", points); 571 572 return 0; 573 } 574 575 struct limit_names { 576 const char *name; 577 const char *unit; 578 }; 579 580 static const struct limit_names lnames[RLIM_NLIMITS] = { 581 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 582 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 583 [RLIMIT_DATA] = {"Max data size", "bytes"}, 584 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 585 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 586 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 587 [RLIMIT_NPROC] = {"Max processes", "processes"}, 588 [RLIMIT_NOFILE] = {"Max open files", "files"}, 589 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 590 [RLIMIT_AS] = {"Max address space", "bytes"}, 591 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 592 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 593 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 594 [RLIMIT_NICE] = {"Max nice priority", NULL}, 595 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 596 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 597 }; 598 599 /* Display limits for a process */ 600 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns, 601 struct pid *pid, struct task_struct *task) 602 { 603 unsigned int i; 604 unsigned long flags; 605 606 struct rlimit rlim[RLIM_NLIMITS]; 607 608 if (!lock_task_sighand(task, &flags)) 609 return 0; 610 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 611 unlock_task_sighand(task, &flags); 612 613 /* 614 * print the file header 615 */ 616 seq_printf(m, "%-25s %-20s %-20s %-10s\n", 617 "Limit", "Soft Limit", "Hard Limit", "Units"); 618 619 for (i = 0; i < RLIM_NLIMITS; i++) { 620 if (rlim[i].rlim_cur == RLIM_INFINITY) 621 seq_printf(m, "%-25s %-20s ", 622 lnames[i].name, "unlimited"); 623 else 624 seq_printf(m, "%-25s %-20lu ", 625 lnames[i].name, rlim[i].rlim_cur); 626 627 if (rlim[i].rlim_max == RLIM_INFINITY) 628 seq_printf(m, "%-20s ", "unlimited"); 629 else 630 seq_printf(m, "%-20lu ", rlim[i].rlim_max); 631 632 if (lnames[i].unit) 633 seq_printf(m, "%-10s\n", lnames[i].unit); 634 else 635 seq_putc(m, '\n'); 636 } 637 638 return 0; 639 } 640 641 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 642 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns, 643 struct pid *pid, struct task_struct *task) 644 { 645 long nr; 646 unsigned long args[6], sp, pc; 647 int res; 648 649 res = lock_trace(task); 650 if (res) 651 return res; 652 653 if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) 654 seq_puts(m, "running\n"); 655 else if (nr < 0) 656 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc); 657 else 658 seq_printf(m, 659 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", 660 nr, 661 args[0], args[1], args[2], args[3], args[4], args[5], 662 sp, pc); 663 unlock_trace(task); 664 665 return 0; 666 } 667 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 668 669 /************************************************************************/ 670 /* Here the fs part begins */ 671 /************************************************************************/ 672 673 /* permission checks */ 674 static int proc_fd_access_allowed(struct inode *inode) 675 { 676 struct task_struct *task; 677 int allowed = 0; 678 /* Allow access to a task's file descriptors if it is us or we 679 * may use ptrace attach to the process and find out that 680 * information. 681 */ 682 task = get_proc_task(inode); 683 if (task) { 684 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 685 put_task_struct(task); 686 } 687 return allowed; 688 } 689 690 int proc_setattr(struct dentry *dentry, struct iattr *attr) 691 { 692 int error; 693 struct inode *inode = d_inode(dentry); 694 695 if (attr->ia_valid & ATTR_MODE) 696 return -EPERM; 697 698 error = setattr_prepare(dentry, attr); 699 if (error) 700 return error; 701 702 setattr_copy(inode, attr); 703 mark_inode_dirty(inode); 704 return 0; 705 } 706 707 /* 708 * May current process learn task's sched/cmdline info (for hide_pid_min=1) 709 * or euid/egid (for hide_pid_min=2)? 710 */ 711 static bool has_pid_permissions(struct pid_namespace *pid, 712 struct task_struct *task, 713 int hide_pid_min) 714 { 715 if (pid->hide_pid < hide_pid_min) 716 return true; 717 if (in_group_p(pid->pid_gid)) 718 return true; 719 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 720 } 721 722 723 static int proc_pid_permission(struct inode *inode, int mask) 724 { 725 struct pid_namespace *pid = inode->i_sb->s_fs_info; 726 struct task_struct *task; 727 bool has_perms; 728 729 task = get_proc_task(inode); 730 if (!task) 731 return -ESRCH; 732 has_perms = has_pid_permissions(pid, task, 1); 733 put_task_struct(task); 734 735 if (!has_perms) { 736 if (pid->hide_pid == 2) { 737 /* 738 * Let's make getdents(), stat(), and open() 739 * consistent with each other. If a process 740 * may not stat() a file, it shouldn't be seen 741 * in procfs at all. 742 */ 743 return -ENOENT; 744 } 745 746 return -EPERM; 747 } 748 return generic_permission(inode, mask); 749 } 750 751 752 753 static const struct inode_operations proc_def_inode_operations = { 754 .setattr = proc_setattr, 755 }; 756 757 static int proc_single_show(struct seq_file *m, void *v) 758 { 759 struct inode *inode = m->private; 760 struct pid_namespace *ns; 761 struct pid *pid; 762 struct task_struct *task; 763 int ret; 764 765 ns = inode->i_sb->s_fs_info; 766 pid = proc_pid(inode); 767 task = get_pid_task(pid, PIDTYPE_PID); 768 if (!task) 769 return -ESRCH; 770 771 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 772 773 put_task_struct(task); 774 return ret; 775 } 776 777 static int proc_single_open(struct inode *inode, struct file *filp) 778 { 779 return single_open(filp, proc_single_show, inode); 780 } 781 782 static const struct file_operations proc_single_file_operations = { 783 .open = proc_single_open, 784 .read = seq_read, 785 .llseek = seq_lseek, 786 .release = single_release, 787 }; 788 789 790 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode) 791 { 792 struct task_struct *task = get_proc_task(inode); 793 struct mm_struct *mm = ERR_PTR(-ESRCH); 794 795 if (task) { 796 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS); 797 put_task_struct(task); 798 799 if (!IS_ERR_OR_NULL(mm)) { 800 /* ensure this mm_struct can't be freed */ 801 atomic_inc(&mm->mm_count); 802 /* but do not pin its memory */ 803 mmput(mm); 804 } 805 } 806 807 return mm; 808 } 809 810 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) 811 { 812 struct mm_struct *mm = proc_mem_open(inode, mode); 813 814 if (IS_ERR(mm)) 815 return PTR_ERR(mm); 816 817 file->private_data = mm; 818 return 0; 819 } 820 821 static int mem_open(struct inode *inode, struct file *file) 822 { 823 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH); 824 825 /* OK to pass negative loff_t, we can catch out-of-range */ 826 file->f_mode |= FMODE_UNSIGNED_OFFSET; 827 828 return ret; 829 } 830 831 static ssize_t mem_rw(struct file *file, char __user *buf, 832 size_t count, loff_t *ppos, int write) 833 { 834 struct mm_struct *mm = file->private_data; 835 unsigned long addr = *ppos; 836 ssize_t copied; 837 char *page; 838 unsigned int flags; 839 840 if (!mm) 841 return 0; 842 843 page = (char *)__get_free_page(GFP_TEMPORARY); 844 if (!page) 845 return -ENOMEM; 846 847 copied = 0; 848 if (!atomic_inc_not_zero(&mm->mm_users)) 849 goto free; 850 851 /* Maybe we should limit FOLL_FORCE to actual ptrace users? */ 852 flags = FOLL_FORCE; 853 if (write) 854 flags |= FOLL_WRITE; 855 856 while (count > 0) { 857 int this_len = min_t(int, count, PAGE_SIZE); 858 859 if (write && copy_from_user(page, buf, this_len)) { 860 copied = -EFAULT; 861 break; 862 } 863 864 this_len = access_remote_vm(mm, addr, page, this_len, flags); 865 if (!this_len) { 866 if (!copied) 867 copied = -EIO; 868 break; 869 } 870 871 if (!write && copy_to_user(buf, page, this_len)) { 872 copied = -EFAULT; 873 break; 874 } 875 876 buf += this_len; 877 addr += this_len; 878 copied += this_len; 879 count -= this_len; 880 } 881 *ppos = addr; 882 883 mmput(mm); 884 free: 885 free_page((unsigned long) page); 886 return copied; 887 } 888 889 static ssize_t mem_read(struct file *file, char __user *buf, 890 size_t count, loff_t *ppos) 891 { 892 return mem_rw(file, buf, count, ppos, 0); 893 } 894 895 static ssize_t mem_write(struct file *file, const char __user *buf, 896 size_t count, loff_t *ppos) 897 { 898 return mem_rw(file, (char __user*)buf, count, ppos, 1); 899 } 900 901 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 902 { 903 switch (orig) { 904 case 0: 905 file->f_pos = offset; 906 break; 907 case 1: 908 file->f_pos += offset; 909 break; 910 default: 911 return -EINVAL; 912 } 913 force_successful_syscall_return(); 914 return file->f_pos; 915 } 916 917 static int mem_release(struct inode *inode, struct file *file) 918 { 919 struct mm_struct *mm = file->private_data; 920 if (mm) 921 mmdrop(mm); 922 return 0; 923 } 924 925 static const struct file_operations proc_mem_operations = { 926 .llseek = mem_lseek, 927 .read = mem_read, 928 .write = mem_write, 929 .open = mem_open, 930 .release = mem_release, 931 }; 932 933 static int environ_open(struct inode *inode, struct file *file) 934 { 935 return __mem_open(inode, file, PTRACE_MODE_READ); 936 } 937 938 static ssize_t environ_read(struct file *file, char __user *buf, 939 size_t count, loff_t *ppos) 940 { 941 char *page; 942 unsigned long src = *ppos; 943 int ret = 0; 944 struct mm_struct *mm = file->private_data; 945 unsigned long env_start, env_end; 946 947 /* Ensure the process spawned far enough to have an environment. */ 948 if (!mm || !mm->env_end) 949 return 0; 950 951 page = (char *)__get_free_page(GFP_TEMPORARY); 952 if (!page) 953 return -ENOMEM; 954 955 ret = 0; 956 if (!atomic_inc_not_zero(&mm->mm_users)) 957 goto free; 958 959 down_read(&mm->mmap_sem); 960 env_start = mm->env_start; 961 env_end = mm->env_end; 962 up_read(&mm->mmap_sem); 963 964 while (count > 0) { 965 size_t this_len, max_len; 966 int retval; 967 968 if (src >= (env_end - env_start)) 969 break; 970 971 this_len = env_end - (env_start + src); 972 973 max_len = min_t(size_t, PAGE_SIZE, count); 974 this_len = min(max_len, this_len); 975 976 retval = access_remote_vm(mm, (env_start + src), page, this_len, 0); 977 978 if (retval <= 0) { 979 ret = retval; 980 break; 981 } 982 983 if (copy_to_user(buf, page, retval)) { 984 ret = -EFAULT; 985 break; 986 } 987 988 ret += retval; 989 src += retval; 990 buf += retval; 991 count -= retval; 992 } 993 *ppos = src; 994 mmput(mm); 995 996 free: 997 free_page((unsigned long) page); 998 return ret; 999 } 1000 1001 static const struct file_operations proc_environ_operations = { 1002 .open = environ_open, 1003 .read = environ_read, 1004 .llseek = generic_file_llseek, 1005 .release = mem_release, 1006 }; 1007 1008 static int auxv_open(struct inode *inode, struct file *file) 1009 { 1010 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS); 1011 } 1012 1013 static ssize_t auxv_read(struct file *file, char __user *buf, 1014 size_t count, loff_t *ppos) 1015 { 1016 struct mm_struct *mm = file->private_data; 1017 unsigned int nwords = 0; 1018 1019 if (!mm) 1020 return 0; 1021 do { 1022 nwords += 2; 1023 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 1024 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv, 1025 nwords * sizeof(mm->saved_auxv[0])); 1026 } 1027 1028 static const struct file_operations proc_auxv_operations = { 1029 .open = auxv_open, 1030 .read = auxv_read, 1031 .llseek = generic_file_llseek, 1032 .release = mem_release, 1033 }; 1034 1035 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count, 1036 loff_t *ppos) 1037 { 1038 struct task_struct *task = get_proc_task(file_inode(file)); 1039 char buffer[PROC_NUMBUF]; 1040 int oom_adj = OOM_ADJUST_MIN; 1041 size_t len; 1042 1043 if (!task) 1044 return -ESRCH; 1045 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX) 1046 oom_adj = OOM_ADJUST_MAX; 1047 else 1048 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) / 1049 OOM_SCORE_ADJ_MAX; 1050 put_task_struct(task); 1051 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj); 1052 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1053 } 1054 1055 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy) 1056 { 1057 static DEFINE_MUTEX(oom_adj_mutex); 1058 struct mm_struct *mm = NULL; 1059 struct task_struct *task; 1060 int err = 0; 1061 1062 task = get_proc_task(file_inode(file)); 1063 if (!task) 1064 return -ESRCH; 1065 1066 mutex_lock(&oom_adj_mutex); 1067 if (legacy) { 1068 if (oom_adj < task->signal->oom_score_adj && 1069 !capable(CAP_SYS_RESOURCE)) { 1070 err = -EACCES; 1071 goto err_unlock; 1072 } 1073 /* 1074 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use 1075 * /proc/pid/oom_score_adj instead. 1076 */ 1077 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 1078 current->comm, task_pid_nr(current), task_pid_nr(task), 1079 task_pid_nr(task)); 1080 } else { 1081 if ((short)oom_adj < task->signal->oom_score_adj_min && 1082 !capable(CAP_SYS_RESOURCE)) { 1083 err = -EACCES; 1084 goto err_unlock; 1085 } 1086 } 1087 1088 /* 1089 * Make sure we will check other processes sharing the mm if this is 1090 * not vfrok which wants its own oom_score_adj. 1091 * pin the mm so it doesn't go away and get reused after task_unlock 1092 */ 1093 if (!task->vfork_done) { 1094 struct task_struct *p = find_lock_task_mm(task); 1095 1096 if (p) { 1097 if (atomic_read(&p->mm->mm_users) > 1) { 1098 mm = p->mm; 1099 atomic_inc(&mm->mm_count); 1100 } 1101 task_unlock(p); 1102 } 1103 } 1104 1105 task->signal->oom_score_adj = oom_adj; 1106 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1107 task->signal->oom_score_adj_min = (short)oom_adj; 1108 trace_oom_score_adj_update(task); 1109 1110 if (mm) { 1111 struct task_struct *p; 1112 1113 rcu_read_lock(); 1114 for_each_process(p) { 1115 if (same_thread_group(task, p)) 1116 continue; 1117 1118 /* do not touch kernel threads or the global init */ 1119 if (p->flags & PF_KTHREAD || is_global_init(p)) 1120 continue; 1121 1122 task_lock(p); 1123 if (!p->vfork_done && process_shares_mm(p, mm)) { 1124 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", 1125 task_pid_nr(p), p->comm, 1126 p->signal->oom_score_adj, oom_adj, 1127 task_pid_nr(task), task->comm); 1128 p->signal->oom_score_adj = oom_adj; 1129 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1130 p->signal->oom_score_adj_min = (short)oom_adj; 1131 } 1132 task_unlock(p); 1133 } 1134 rcu_read_unlock(); 1135 mmdrop(mm); 1136 } 1137 err_unlock: 1138 mutex_unlock(&oom_adj_mutex); 1139 put_task_struct(task); 1140 return err; 1141 } 1142 1143 /* 1144 * /proc/pid/oom_adj exists solely for backwards compatibility with previous 1145 * kernels. The effective policy is defined by oom_score_adj, which has a 1146 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly. 1147 * Values written to oom_adj are simply mapped linearly to oom_score_adj. 1148 * Processes that become oom disabled via oom_adj will still be oom disabled 1149 * with this implementation. 1150 * 1151 * oom_adj cannot be removed since existing userspace binaries use it. 1152 */ 1153 static ssize_t oom_adj_write(struct file *file, const char __user *buf, 1154 size_t count, loff_t *ppos) 1155 { 1156 char buffer[PROC_NUMBUF]; 1157 int oom_adj; 1158 int err; 1159 1160 memset(buffer, 0, sizeof(buffer)); 1161 if (count > sizeof(buffer) - 1) 1162 count = sizeof(buffer) - 1; 1163 if (copy_from_user(buffer, buf, count)) { 1164 err = -EFAULT; 1165 goto out; 1166 } 1167 1168 err = kstrtoint(strstrip(buffer), 0, &oom_adj); 1169 if (err) 1170 goto out; 1171 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) && 1172 oom_adj != OOM_DISABLE) { 1173 err = -EINVAL; 1174 goto out; 1175 } 1176 1177 /* 1178 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 1179 * value is always attainable. 1180 */ 1181 if (oom_adj == OOM_ADJUST_MAX) 1182 oom_adj = OOM_SCORE_ADJ_MAX; 1183 else 1184 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE; 1185 1186 err = __set_oom_adj(file, oom_adj, true); 1187 out: 1188 return err < 0 ? err : count; 1189 } 1190 1191 static const struct file_operations proc_oom_adj_operations = { 1192 .read = oom_adj_read, 1193 .write = oom_adj_write, 1194 .llseek = generic_file_llseek, 1195 }; 1196 1197 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 1198 size_t count, loff_t *ppos) 1199 { 1200 struct task_struct *task = get_proc_task(file_inode(file)); 1201 char buffer[PROC_NUMBUF]; 1202 short oom_score_adj = OOM_SCORE_ADJ_MIN; 1203 size_t len; 1204 1205 if (!task) 1206 return -ESRCH; 1207 oom_score_adj = task->signal->oom_score_adj; 1208 put_task_struct(task); 1209 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj); 1210 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1211 } 1212 1213 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1214 size_t count, loff_t *ppos) 1215 { 1216 char buffer[PROC_NUMBUF]; 1217 int oom_score_adj; 1218 int err; 1219 1220 memset(buffer, 0, sizeof(buffer)); 1221 if (count > sizeof(buffer) - 1) 1222 count = sizeof(buffer) - 1; 1223 if (copy_from_user(buffer, buf, count)) { 1224 err = -EFAULT; 1225 goto out; 1226 } 1227 1228 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 1229 if (err) 1230 goto out; 1231 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1232 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1233 err = -EINVAL; 1234 goto out; 1235 } 1236 1237 err = __set_oom_adj(file, oom_score_adj, false); 1238 out: 1239 return err < 0 ? err : count; 1240 } 1241 1242 static const struct file_operations proc_oom_score_adj_operations = { 1243 .read = oom_score_adj_read, 1244 .write = oom_score_adj_write, 1245 .llseek = default_llseek, 1246 }; 1247 1248 #ifdef CONFIG_AUDITSYSCALL 1249 #define TMPBUFLEN 11 1250 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1251 size_t count, loff_t *ppos) 1252 { 1253 struct inode * inode = file_inode(file); 1254 struct task_struct *task = get_proc_task(inode); 1255 ssize_t length; 1256 char tmpbuf[TMPBUFLEN]; 1257 1258 if (!task) 1259 return -ESRCH; 1260 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1261 from_kuid(file->f_cred->user_ns, 1262 audit_get_loginuid(task))); 1263 put_task_struct(task); 1264 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1265 } 1266 1267 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1268 size_t count, loff_t *ppos) 1269 { 1270 struct inode * inode = file_inode(file); 1271 uid_t loginuid; 1272 kuid_t kloginuid; 1273 int rv; 1274 1275 rcu_read_lock(); 1276 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1277 rcu_read_unlock(); 1278 return -EPERM; 1279 } 1280 rcu_read_unlock(); 1281 1282 if (*ppos != 0) { 1283 /* No partial writes. */ 1284 return -EINVAL; 1285 } 1286 1287 rv = kstrtou32_from_user(buf, count, 10, &loginuid); 1288 if (rv < 0) 1289 return rv; 1290 1291 /* is userspace tring to explicitly UNSET the loginuid? */ 1292 if (loginuid == AUDIT_UID_UNSET) { 1293 kloginuid = INVALID_UID; 1294 } else { 1295 kloginuid = make_kuid(file->f_cred->user_ns, loginuid); 1296 if (!uid_valid(kloginuid)) 1297 return -EINVAL; 1298 } 1299 1300 rv = audit_set_loginuid(kloginuid); 1301 if (rv < 0) 1302 return rv; 1303 return count; 1304 } 1305 1306 static const struct file_operations proc_loginuid_operations = { 1307 .read = proc_loginuid_read, 1308 .write = proc_loginuid_write, 1309 .llseek = generic_file_llseek, 1310 }; 1311 1312 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1313 size_t count, loff_t *ppos) 1314 { 1315 struct inode * inode = file_inode(file); 1316 struct task_struct *task = get_proc_task(inode); 1317 ssize_t length; 1318 char tmpbuf[TMPBUFLEN]; 1319 1320 if (!task) 1321 return -ESRCH; 1322 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1323 audit_get_sessionid(task)); 1324 put_task_struct(task); 1325 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1326 } 1327 1328 static const struct file_operations proc_sessionid_operations = { 1329 .read = proc_sessionid_read, 1330 .llseek = generic_file_llseek, 1331 }; 1332 #endif 1333 1334 #ifdef CONFIG_FAULT_INJECTION 1335 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1336 size_t count, loff_t *ppos) 1337 { 1338 struct task_struct *task = get_proc_task(file_inode(file)); 1339 char buffer[PROC_NUMBUF]; 1340 size_t len; 1341 int make_it_fail; 1342 1343 if (!task) 1344 return -ESRCH; 1345 make_it_fail = task->make_it_fail; 1346 put_task_struct(task); 1347 1348 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1349 1350 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1351 } 1352 1353 static ssize_t proc_fault_inject_write(struct file * file, 1354 const char __user * buf, size_t count, loff_t *ppos) 1355 { 1356 struct task_struct *task; 1357 char buffer[PROC_NUMBUF]; 1358 int make_it_fail; 1359 int rv; 1360 1361 if (!capable(CAP_SYS_RESOURCE)) 1362 return -EPERM; 1363 memset(buffer, 0, sizeof(buffer)); 1364 if (count > sizeof(buffer) - 1) 1365 count = sizeof(buffer) - 1; 1366 if (copy_from_user(buffer, buf, count)) 1367 return -EFAULT; 1368 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail); 1369 if (rv < 0) 1370 return rv; 1371 if (make_it_fail < 0 || make_it_fail > 1) 1372 return -EINVAL; 1373 1374 task = get_proc_task(file_inode(file)); 1375 if (!task) 1376 return -ESRCH; 1377 task->make_it_fail = make_it_fail; 1378 put_task_struct(task); 1379 1380 return count; 1381 } 1382 1383 static const struct file_operations proc_fault_inject_operations = { 1384 .read = proc_fault_inject_read, 1385 .write = proc_fault_inject_write, 1386 .llseek = generic_file_llseek, 1387 }; 1388 #endif 1389 1390 1391 #ifdef CONFIG_SCHED_DEBUG 1392 /* 1393 * Print out various scheduling related per-task fields: 1394 */ 1395 static int sched_show(struct seq_file *m, void *v) 1396 { 1397 struct inode *inode = m->private; 1398 struct task_struct *p; 1399 1400 p = get_proc_task(inode); 1401 if (!p) 1402 return -ESRCH; 1403 proc_sched_show_task(p, m); 1404 1405 put_task_struct(p); 1406 1407 return 0; 1408 } 1409 1410 static ssize_t 1411 sched_write(struct file *file, const char __user *buf, 1412 size_t count, loff_t *offset) 1413 { 1414 struct inode *inode = file_inode(file); 1415 struct task_struct *p; 1416 1417 p = get_proc_task(inode); 1418 if (!p) 1419 return -ESRCH; 1420 proc_sched_set_task(p); 1421 1422 put_task_struct(p); 1423 1424 return count; 1425 } 1426 1427 static int sched_open(struct inode *inode, struct file *filp) 1428 { 1429 return single_open(filp, sched_show, inode); 1430 } 1431 1432 static const struct file_operations proc_pid_sched_operations = { 1433 .open = sched_open, 1434 .read = seq_read, 1435 .write = sched_write, 1436 .llseek = seq_lseek, 1437 .release = single_release, 1438 }; 1439 1440 #endif 1441 1442 #ifdef CONFIG_SCHED_AUTOGROUP 1443 /* 1444 * Print out autogroup related information: 1445 */ 1446 static int sched_autogroup_show(struct seq_file *m, void *v) 1447 { 1448 struct inode *inode = m->private; 1449 struct task_struct *p; 1450 1451 p = get_proc_task(inode); 1452 if (!p) 1453 return -ESRCH; 1454 proc_sched_autogroup_show_task(p, m); 1455 1456 put_task_struct(p); 1457 1458 return 0; 1459 } 1460 1461 static ssize_t 1462 sched_autogroup_write(struct file *file, const char __user *buf, 1463 size_t count, loff_t *offset) 1464 { 1465 struct inode *inode = file_inode(file); 1466 struct task_struct *p; 1467 char buffer[PROC_NUMBUF]; 1468 int nice; 1469 int err; 1470 1471 memset(buffer, 0, sizeof(buffer)); 1472 if (count > sizeof(buffer) - 1) 1473 count = sizeof(buffer) - 1; 1474 if (copy_from_user(buffer, buf, count)) 1475 return -EFAULT; 1476 1477 err = kstrtoint(strstrip(buffer), 0, &nice); 1478 if (err < 0) 1479 return err; 1480 1481 p = get_proc_task(inode); 1482 if (!p) 1483 return -ESRCH; 1484 1485 err = proc_sched_autogroup_set_nice(p, nice); 1486 if (err) 1487 count = err; 1488 1489 put_task_struct(p); 1490 1491 return count; 1492 } 1493 1494 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1495 { 1496 int ret; 1497 1498 ret = single_open(filp, sched_autogroup_show, NULL); 1499 if (!ret) { 1500 struct seq_file *m = filp->private_data; 1501 1502 m->private = inode; 1503 } 1504 return ret; 1505 } 1506 1507 static const struct file_operations proc_pid_sched_autogroup_operations = { 1508 .open = sched_autogroup_open, 1509 .read = seq_read, 1510 .write = sched_autogroup_write, 1511 .llseek = seq_lseek, 1512 .release = single_release, 1513 }; 1514 1515 #endif /* CONFIG_SCHED_AUTOGROUP */ 1516 1517 static ssize_t comm_write(struct file *file, const char __user *buf, 1518 size_t count, loff_t *offset) 1519 { 1520 struct inode *inode = file_inode(file); 1521 struct task_struct *p; 1522 char buffer[TASK_COMM_LEN]; 1523 const size_t maxlen = sizeof(buffer) - 1; 1524 1525 memset(buffer, 0, sizeof(buffer)); 1526 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count)) 1527 return -EFAULT; 1528 1529 p = get_proc_task(inode); 1530 if (!p) 1531 return -ESRCH; 1532 1533 if (same_thread_group(current, p)) 1534 set_task_comm(p, buffer); 1535 else 1536 count = -EINVAL; 1537 1538 put_task_struct(p); 1539 1540 return count; 1541 } 1542 1543 static int comm_show(struct seq_file *m, void *v) 1544 { 1545 struct inode *inode = m->private; 1546 struct task_struct *p; 1547 1548 p = get_proc_task(inode); 1549 if (!p) 1550 return -ESRCH; 1551 1552 task_lock(p); 1553 seq_printf(m, "%s\n", p->comm); 1554 task_unlock(p); 1555 1556 put_task_struct(p); 1557 1558 return 0; 1559 } 1560 1561 static int comm_open(struct inode *inode, struct file *filp) 1562 { 1563 return single_open(filp, comm_show, inode); 1564 } 1565 1566 static const struct file_operations proc_pid_set_comm_operations = { 1567 .open = comm_open, 1568 .read = seq_read, 1569 .write = comm_write, 1570 .llseek = seq_lseek, 1571 .release = single_release, 1572 }; 1573 1574 static int proc_exe_link(struct dentry *dentry, struct path *exe_path) 1575 { 1576 struct task_struct *task; 1577 struct file *exe_file; 1578 1579 task = get_proc_task(d_inode(dentry)); 1580 if (!task) 1581 return -ENOENT; 1582 exe_file = get_task_exe_file(task); 1583 put_task_struct(task); 1584 if (exe_file) { 1585 *exe_path = exe_file->f_path; 1586 path_get(&exe_file->f_path); 1587 fput(exe_file); 1588 return 0; 1589 } else 1590 return -ENOENT; 1591 } 1592 1593 static const char *proc_pid_get_link(struct dentry *dentry, 1594 struct inode *inode, 1595 struct delayed_call *done) 1596 { 1597 struct path path; 1598 int error = -EACCES; 1599 1600 if (!dentry) 1601 return ERR_PTR(-ECHILD); 1602 1603 /* Are we allowed to snoop on the tasks file descriptors? */ 1604 if (!proc_fd_access_allowed(inode)) 1605 goto out; 1606 1607 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1608 if (error) 1609 goto out; 1610 1611 nd_jump_link(&path); 1612 return NULL; 1613 out: 1614 return ERR_PTR(error); 1615 } 1616 1617 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1618 { 1619 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1620 char *pathname; 1621 int len; 1622 1623 if (!tmp) 1624 return -ENOMEM; 1625 1626 pathname = d_path(path, tmp, PAGE_SIZE); 1627 len = PTR_ERR(pathname); 1628 if (IS_ERR(pathname)) 1629 goto out; 1630 len = tmp + PAGE_SIZE - 1 - pathname; 1631 1632 if (len > buflen) 1633 len = buflen; 1634 if (copy_to_user(buffer, pathname, len)) 1635 len = -EFAULT; 1636 out: 1637 free_page((unsigned long)tmp); 1638 return len; 1639 } 1640 1641 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1642 { 1643 int error = -EACCES; 1644 struct inode *inode = d_inode(dentry); 1645 struct path path; 1646 1647 /* Are we allowed to snoop on the tasks file descriptors? */ 1648 if (!proc_fd_access_allowed(inode)) 1649 goto out; 1650 1651 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1652 if (error) 1653 goto out; 1654 1655 error = do_proc_readlink(&path, buffer, buflen); 1656 path_put(&path); 1657 out: 1658 return error; 1659 } 1660 1661 const struct inode_operations proc_pid_link_inode_operations = { 1662 .readlink = proc_pid_readlink, 1663 .get_link = proc_pid_get_link, 1664 .setattr = proc_setattr, 1665 }; 1666 1667 1668 /* building an inode */ 1669 1670 struct inode *proc_pid_make_inode(struct super_block * sb, 1671 struct task_struct *task, umode_t mode) 1672 { 1673 struct inode * inode; 1674 struct proc_inode *ei; 1675 const struct cred *cred; 1676 1677 /* We need a new inode */ 1678 1679 inode = new_inode(sb); 1680 if (!inode) 1681 goto out; 1682 1683 /* Common stuff */ 1684 ei = PROC_I(inode); 1685 inode->i_mode = mode; 1686 inode->i_ino = get_next_ino(); 1687 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 1688 inode->i_op = &proc_def_inode_operations; 1689 1690 /* 1691 * grab the reference to task. 1692 */ 1693 ei->pid = get_task_pid(task, PIDTYPE_PID); 1694 if (!ei->pid) 1695 goto out_unlock; 1696 1697 if (task_dumpable(task)) { 1698 rcu_read_lock(); 1699 cred = __task_cred(task); 1700 inode->i_uid = cred->euid; 1701 inode->i_gid = cred->egid; 1702 rcu_read_unlock(); 1703 } 1704 security_task_to_inode(task, inode); 1705 1706 out: 1707 return inode; 1708 1709 out_unlock: 1710 iput(inode); 1711 return NULL; 1712 } 1713 1714 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1715 { 1716 struct inode *inode = d_inode(dentry); 1717 struct task_struct *task; 1718 const struct cred *cred; 1719 struct pid_namespace *pid = dentry->d_sb->s_fs_info; 1720 1721 generic_fillattr(inode, stat); 1722 1723 rcu_read_lock(); 1724 stat->uid = GLOBAL_ROOT_UID; 1725 stat->gid = GLOBAL_ROOT_GID; 1726 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1727 if (task) { 1728 if (!has_pid_permissions(pid, task, 2)) { 1729 rcu_read_unlock(); 1730 /* 1731 * This doesn't prevent learning whether PID exists, 1732 * it only makes getattr() consistent with readdir(). 1733 */ 1734 return -ENOENT; 1735 } 1736 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1737 task_dumpable(task)) { 1738 cred = __task_cred(task); 1739 stat->uid = cred->euid; 1740 stat->gid = cred->egid; 1741 } 1742 } 1743 rcu_read_unlock(); 1744 return 0; 1745 } 1746 1747 /* dentry stuff */ 1748 1749 /* 1750 * Exceptional case: normally we are not allowed to unhash a busy 1751 * directory. In this case, however, we can do it - no aliasing problems 1752 * due to the way we treat inodes. 1753 * 1754 * Rewrite the inode's ownerships here because the owning task may have 1755 * performed a setuid(), etc. 1756 * 1757 * Before the /proc/pid/status file was created the only way to read 1758 * the effective uid of a /process was to stat /proc/pid. Reading 1759 * /proc/pid/status is slow enough that procps and other packages 1760 * kept stating /proc/pid. To keep the rules in /proc simple I have 1761 * made this apply to all per process world readable and executable 1762 * directories. 1763 */ 1764 int pid_revalidate(struct dentry *dentry, unsigned int flags) 1765 { 1766 struct inode *inode; 1767 struct task_struct *task; 1768 const struct cred *cred; 1769 1770 if (flags & LOOKUP_RCU) 1771 return -ECHILD; 1772 1773 inode = d_inode(dentry); 1774 task = get_proc_task(inode); 1775 1776 if (task) { 1777 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1778 task_dumpable(task)) { 1779 rcu_read_lock(); 1780 cred = __task_cred(task); 1781 inode->i_uid = cred->euid; 1782 inode->i_gid = cred->egid; 1783 rcu_read_unlock(); 1784 } else { 1785 inode->i_uid = GLOBAL_ROOT_UID; 1786 inode->i_gid = GLOBAL_ROOT_GID; 1787 } 1788 inode->i_mode &= ~(S_ISUID | S_ISGID); 1789 security_task_to_inode(task, inode); 1790 put_task_struct(task); 1791 return 1; 1792 } 1793 return 0; 1794 } 1795 1796 static inline bool proc_inode_is_dead(struct inode *inode) 1797 { 1798 return !proc_pid(inode)->tasks[PIDTYPE_PID].first; 1799 } 1800 1801 int pid_delete_dentry(const struct dentry *dentry) 1802 { 1803 /* Is the task we represent dead? 1804 * If so, then don't put the dentry on the lru list, 1805 * kill it immediately. 1806 */ 1807 return proc_inode_is_dead(d_inode(dentry)); 1808 } 1809 1810 const struct dentry_operations pid_dentry_operations = 1811 { 1812 .d_revalidate = pid_revalidate, 1813 .d_delete = pid_delete_dentry, 1814 }; 1815 1816 /* Lookups */ 1817 1818 /* 1819 * Fill a directory entry. 1820 * 1821 * If possible create the dcache entry and derive our inode number and 1822 * file type from dcache entry. 1823 * 1824 * Since all of the proc inode numbers are dynamically generated, the inode 1825 * numbers do not exist until the inode is cache. This means creating the 1826 * the dcache entry in readdir is necessary to keep the inode numbers 1827 * reported by readdir in sync with the inode numbers reported 1828 * by stat. 1829 */ 1830 bool proc_fill_cache(struct file *file, struct dir_context *ctx, 1831 const char *name, int len, 1832 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1833 { 1834 struct dentry *child, *dir = file->f_path.dentry; 1835 struct qstr qname = QSTR_INIT(name, len); 1836 struct inode *inode; 1837 unsigned type; 1838 ino_t ino; 1839 1840 child = d_hash_and_lookup(dir, &qname); 1841 if (!child) { 1842 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 1843 child = d_alloc_parallel(dir, &qname, &wq); 1844 if (IS_ERR(child)) 1845 goto end_instantiate; 1846 if (d_in_lookup(child)) { 1847 int err = instantiate(d_inode(dir), child, task, ptr); 1848 d_lookup_done(child); 1849 if (err < 0) { 1850 dput(child); 1851 goto end_instantiate; 1852 } 1853 } 1854 } 1855 inode = d_inode(child); 1856 ino = inode->i_ino; 1857 type = inode->i_mode >> 12; 1858 dput(child); 1859 return dir_emit(ctx, name, len, ino, type); 1860 1861 end_instantiate: 1862 return dir_emit(ctx, name, len, 1, DT_UNKNOWN); 1863 } 1864 1865 /* 1866 * dname_to_vma_addr - maps a dentry name into two unsigned longs 1867 * which represent vma start and end addresses. 1868 */ 1869 static int dname_to_vma_addr(struct dentry *dentry, 1870 unsigned long *start, unsigned long *end) 1871 { 1872 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2) 1873 return -EINVAL; 1874 1875 return 0; 1876 } 1877 1878 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags) 1879 { 1880 unsigned long vm_start, vm_end; 1881 bool exact_vma_exists = false; 1882 struct mm_struct *mm = NULL; 1883 struct task_struct *task; 1884 const struct cred *cred; 1885 struct inode *inode; 1886 int status = 0; 1887 1888 if (flags & LOOKUP_RCU) 1889 return -ECHILD; 1890 1891 inode = d_inode(dentry); 1892 task = get_proc_task(inode); 1893 if (!task) 1894 goto out_notask; 1895 1896 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); 1897 if (IS_ERR_OR_NULL(mm)) 1898 goto out; 1899 1900 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 1901 down_read(&mm->mmap_sem); 1902 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end); 1903 up_read(&mm->mmap_sem); 1904 } 1905 1906 mmput(mm); 1907 1908 if (exact_vma_exists) { 1909 if (task_dumpable(task)) { 1910 rcu_read_lock(); 1911 cred = __task_cred(task); 1912 inode->i_uid = cred->euid; 1913 inode->i_gid = cred->egid; 1914 rcu_read_unlock(); 1915 } else { 1916 inode->i_uid = GLOBAL_ROOT_UID; 1917 inode->i_gid = GLOBAL_ROOT_GID; 1918 } 1919 security_task_to_inode(task, inode); 1920 status = 1; 1921 } 1922 1923 out: 1924 put_task_struct(task); 1925 1926 out_notask: 1927 return status; 1928 } 1929 1930 static const struct dentry_operations tid_map_files_dentry_operations = { 1931 .d_revalidate = map_files_d_revalidate, 1932 .d_delete = pid_delete_dentry, 1933 }; 1934 1935 static int map_files_get_link(struct dentry *dentry, struct path *path) 1936 { 1937 unsigned long vm_start, vm_end; 1938 struct vm_area_struct *vma; 1939 struct task_struct *task; 1940 struct mm_struct *mm; 1941 int rc; 1942 1943 rc = -ENOENT; 1944 task = get_proc_task(d_inode(dentry)); 1945 if (!task) 1946 goto out; 1947 1948 mm = get_task_mm(task); 1949 put_task_struct(task); 1950 if (!mm) 1951 goto out; 1952 1953 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 1954 if (rc) 1955 goto out_mmput; 1956 1957 rc = -ENOENT; 1958 down_read(&mm->mmap_sem); 1959 vma = find_exact_vma(mm, vm_start, vm_end); 1960 if (vma && vma->vm_file) { 1961 *path = vma->vm_file->f_path; 1962 path_get(path); 1963 rc = 0; 1964 } 1965 up_read(&mm->mmap_sem); 1966 1967 out_mmput: 1968 mmput(mm); 1969 out: 1970 return rc; 1971 } 1972 1973 struct map_files_info { 1974 fmode_t mode; 1975 unsigned int len; 1976 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */ 1977 }; 1978 1979 /* 1980 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the 1981 * symlinks may be used to bypass permissions on ancestor directories in the 1982 * path to the file in question. 1983 */ 1984 static const char * 1985 proc_map_files_get_link(struct dentry *dentry, 1986 struct inode *inode, 1987 struct delayed_call *done) 1988 { 1989 if (!capable(CAP_SYS_ADMIN)) 1990 return ERR_PTR(-EPERM); 1991 1992 return proc_pid_get_link(dentry, inode, done); 1993 } 1994 1995 /* 1996 * Identical to proc_pid_link_inode_operations except for get_link() 1997 */ 1998 static const struct inode_operations proc_map_files_link_inode_operations = { 1999 .readlink = proc_pid_readlink, 2000 .get_link = proc_map_files_get_link, 2001 .setattr = proc_setattr, 2002 }; 2003 2004 static int 2005 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry, 2006 struct task_struct *task, const void *ptr) 2007 { 2008 fmode_t mode = (fmode_t)(unsigned long)ptr; 2009 struct proc_inode *ei; 2010 struct inode *inode; 2011 2012 inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK | 2013 ((mode & FMODE_READ ) ? S_IRUSR : 0) | 2014 ((mode & FMODE_WRITE) ? S_IWUSR : 0)); 2015 if (!inode) 2016 return -ENOENT; 2017 2018 ei = PROC_I(inode); 2019 ei->op.proc_get_link = map_files_get_link; 2020 2021 inode->i_op = &proc_map_files_link_inode_operations; 2022 inode->i_size = 64; 2023 2024 d_set_d_op(dentry, &tid_map_files_dentry_operations); 2025 d_add(dentry, inode); 2026 2027 return 0; 2028 } 2029 2030 static struct dentry *proc_map_files_lookup(struct inode *dir, 2031 struct dentry *dentry, unsigned int flags) 2032 { 2033 unsigned long vm_start, vm_end; 2034 struct vm_area_struct *vma; 2035 struct task_struct *task; 2036 int result; 2037 struct mm_struct *mm; 2038 2039 result = -ENOENT; 2040 task = get_proc_task(dir); 2041 if (!task) 2042 goto out; 2043 2044 result = -EACCES; 2045 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2046 goto out_put_task; 2047 2048 result = -ENOENT; 2049 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 2050 goto out_put_task; 2051 2052 mm = get_task_mm(task); 2053 if (!mm) 2054 goto out_put_task; 2055 2056 down_read(&mm->mmap_sem); 2057 vma = find_exact_vma(mm, vm_start, vm_end); 2058 if (!vma) 2059 goto out_no_vma; 2060 2061 if (vma->vm_file) 2062 result = proc_map_files_instantiate(dir, dentry, task, 2063 (void *)(unsigned long)vma->vm_file->f_mode); 2064 2065 out_no_vma: 2066 up_read(&mm->mmap_sem); 2067 mmput(mm); 2068 out_put_task: 2069 put_task_struct(task); 2070 out: 2071 return ERR_PTR(result); 2072 } 2073 2074 static const struct inode_operations proc_map_files_inode_operations = { 2075 .lookup = proc_map_files_lookup, 2076 .permission = proc_fd_permission, 2077 .setattr = proc_setattr, 2078 }; 2079 2080 static int 2081 proc_map_files_readdir(struct file *file, struct dir_context *ctx) 2082 { 2083 struct vm_area_struct *vma; 2084 struct task_struct *task; 2085 struct mm_struct *mm; 2086 unsigned long nr_files, pos, i; 2087 struct flex_array *fa = NULL; 2088 struct map_files_info info; 2089 struct map_files_info *p; 2090 int ret; 2091 2092 ret = -ENOENT; 2093 task = get_proc_task(file_inode(file)); 2094 if (!task) 2095 goto out; 2096 2097 ret = -EACCES; 2098 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2099 goto out_put_task; 2100 2101 ret = 0; 2102 if (!dir_emit_dots(file, ctx)) 2103 goto out_put_task; 2104 2105 mm = get_task_mm(task); 2106 if (!mm) 2107 goto out_put_task; 2108 down_read(&mm->mmap_sem); 2109 2110 nr_files = 0; 2111 2112 /* 2113 * We need two passes here: 2114 * 2115 * 1) Collect vmas of mapped files with mmap_sem taken 2116 * 2) Release mmap_sem and instantiate entries 2117 * 2118 * otherwise we get lockdep complained, since filldir() 2119 * routine might require mmap_sem taken in might_fault(). 2120 */ 2121 2122 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 2123 if (vma->vm_file && ++pos > ctx->pos) 2124 nr_files++; 2125 } 2126 2127 if (nr_files) { 2128 fa = flex_array_alloc(sizeof(info), nr_files, 2129 GFP_KERNEL); 2130 if (!fa || flex_array_prealloc(fa, 0, nr_files, 2131 GFP_KERNEL)) { 2132 ret = -ENOMEM; 2133 if (fa) 2134 flex_array_free(fa); 2135 up_read(&mm->mmap_sem); 2136 mmput(mm); 2137 goto out_put_task; 2138 } 2139 for (i = 0, vma = mm->mmap, pos = 2; vma; 2140 vma = vma->vm_next) { 2141 if (!vma->vm_file) 2142 continue; 2143 if (++pos <= ctx->pos) 2144 continue; 2145 2146 info.mode = vma->vm_file->f_mode; 2147 info.len = snprintf(info.name, 2148 sizeof(info.name), "%lx-%lx", 2149 vma->vm_start, vma->vm_end); 2150 if (flex_array_put(fa, i++, &info, GFP_KERNEL)) 2151 BUG(); 2152 } 2153 } 2154 up_read(&mm->mmap_sem); 2155 2156 for (i = 0; i < nr_files; i++) { 2157 p = flex_array_get(fa, i); 2158 if (!proc_fill_cache(file, ctx, 2159 p->name, p->len, 2160 proc_map_files_instantiate, 2161 task, 2162 (void *)(unsigned long)p->mode)) 2163 break; 2164 ctx->pos++; 2165 } 2166 if (fa) 2167 flex_array_free(fa); 2168 mmput(mm); 2169 2170 out_put_task: 2171 put_task_struct(task); 2172 out: 2173 return ret; 2174 } 2175 2176 static const struct file_operations proc_map_files_operations = { 2177 .read = generic_read_dir, 2178 .iterate_shared = proc_map_files_readdir, 2179 .llseek = generic_file_llseek, 2180 }; 2181 2182 #ifdef CONFIG_CHECKPOINT_RESTORE 2183 struct timers_private { 2184 struct pid *pid; 2185 struct task_struct *task; 2186 struct sighand_struct *sighand; 2187 struct pid_namespace *ns; 2188 unsigned long flags; 2189 }; 2190 2191 static void *timers_start(struct seq_file *m, loff_t *pos) 2192 { 2193 struct timers_private *tp = m->private; 2194 2195 tp->task = get_pid_task(tp->pid, PIDTYPE_PID); 2196 if (!tp->task) 2197 return ERR_PTR(-ESRCH); 2198 2199 tp->sighand = lock_task_sighand(tp->task, &tp->flags); 2200 if (!tp->sighand) 2201 return ERR_PTR(-ESRCH); 2202 2203 return seq_list_start(&tp->task->signal->posix_timers, *pos); 2204 } 2205 2206 static void *timers_next(struct seq_file *m, void *v, loff_t *pos) 2207 { 2208 struct timers_private *tp = m->private; 2209 return seq_list_next(v, &tp->task->signal->posix_timers, pos); 2210 } 2211 2212 static void timers_stop(struct seq_file *m, void *v) 2213 { 2214 struct timers_private *tp = m->private; 2215 2216 if (tp->sighand) { 2217 unlock_task_sighand(tp->task, &tp->flags); 2218 tp->sighand = NULL; 2219 } 2220 2221 if (tp->task) { 2222 put_task_struct(tp->task); 2223 tp->task = NULL; 2224 } 2225 } 2226 2227 static int show_timer(struct seq_file *m, void *v) 2228 { 2229 struct k_itimer *timer; 2230 struct timers_private *tp = m->private; 2231 int notify; 2232 static const char * const nstr[] = { 2233 [SIGEV_SIGNAL] = "signal", 2234 [SIGEV_NONE] = "none", 2235 [SIGEV_THREAD] = "thread", 2236 }; 2237 2238 timer = list_entry((struct list_head *)v, struct k_itimer, list); 2239 notify = timer->it_sigev_notify; 2240 2241 seq_printf(m, "ID: %d\n", timer->it_id); 2242 seq_printf(m, "signal: %d/%p\n", 2243 timer->sigq->info.si_signo, 2244 timer->sigq->info.si_value.sival_ptr); 2245 seq_printf(m, "notify: %s/%s.%d\n", 2246 nstr[notify & ~SIGEV_THREAD_ID], 2247 (notify & SIGEV_THREAD_ID) ? "tid" : "pid", 2248 pid_nr_ns(timer->it_pid, tp->ns)); 2249 seq_printf(m, "ClockID: %d\n", timer->it_clock); 2250 2251 return 0; 2252 } 2253 2254 static const struct seq_operations proc_timers_seq_ops = { 2255 .start = timers_start, 2256 .next = timers_next, 2257 .stop = timers_stop, 2258 .show = show_timer, 2259 }; 2260 2261 static int proc_timers_open(struct inode *inode, struct file *file) 2262 { 2263 struct timers_private *tp; 2264 2265 tp = __seq_open_private(file, &proc_timers_seq_ops, 2266 sizeof(struct timers_private)); 2267 if (!tp) 2268 return -ENOMEM; 2269 2270 tp->pid = proc_pid(inode); 2271 tp->ns = inode->i_sb->s_fs_info; 2272 return 0; 2273 } 2274 2275 static const struct file_operations proc_timers_operations = { 2276 .open = proc_timers_open, 2277 .read = seq_read, 2278 .llseek = seq_lseek, 2279 .release = seq_release_private, 2280 }; 2281 #endif 2282 2283 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf, 2284 size_t count, loff_t *offset) 2285 { 2286 struct inode *inode = file_inode(file); 2287 struct task_struct *p; 2288 u64 slack_ns; 2289 int err; 2290 2291 err = kstrtoull_from_user(buf, count, 10, &slack_ns); 2292 if (err < 0) 2293 return err; 2294 2295 p = get_proc_task(inode); 2296 if (!p) 2297 return -ESRCH; 2298 2299 if (p != current) { 2300 if (!capable(CAP_SYS_NICE)) { 2301 count = -EPERM; 2302 goto out; 2303 } 2304 2305 err = security_task_setscheduler(p); 2306 if (err) { 2307 count = err; 2308 goto out; 2309 } 2310 } 2311 2312 task_lock(p); 2313 if (slack_ns == 0) 2314 p->timer_slack_ns = p->default_timer_slack_ns; 2315 else 2316 p->timer_slack_ns = slack_ns; 2317 task_unlock(p); 2318 2319 out: 2320 put_task_struct(p); 2321 2322 return count; 2323 } 2324 2325 static int timerslack_ns_show(struct seq_file *m, void *v) 2326 { 2327 struct inode *inode = m->private; 2328 struct task_struct *p; 2329 int err = 0; 2330 2331 p = get_proc_task(inode); 2332 if (!p) 2333 return -ESRCH; 2334 2335 if (p != current) { 2336 2337 if (!capable(CAP_SYS_NICE)) { 2338 err = -EPERM; 2339 goto out; 2340 } 2341 err = security_task_getscheduler(p); 2342 if (err) 2343 goto out; 2344 } 2345 2346 task_lock(p); 2347 seq_printf(m, "%llu\n", p->timer_slack_ns); 2348 task_unlock(p); 2349 2350 out: 2351 put_task_struct(p); 2352 2353 return err; 2354 } 2355 2356 static int timerslack_ns_open(struct inode *inode, struct file *filp) 2357 { 2358 return single_open(filp, timerslack_ns_show, inode); 2359 } 2360 2361 static const struct file_operations proc_pid_set_timerslack_ns_operations = { 2362 .open = timerslack_ns_open, 2363 .read = seq_read, 2364 .write = timerslack_ns_write, 2365 .llseek = seq_lseek, 2366 .release = single_release, 2367 }; 2368 2369 static int proc_pident_instantiate(struct inode *dir, 2370 struct dentry *dentry, struct task_struct *task, const void *ptr) 2371 { 2372 const struct pid_entry *p = ptr; 2373 struct inode *inode; 2374 struct proc_inode *ei; 2375 2376 inode = proc_pid_make_inode(dir->i_sb, task, p->mode); 2377 if (!inode) 2378 goto out; 2379 2380 ei = PROC_I(inode); 2381 if (S_ISDIR(inode->i_mode)) 2382 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2383 if (p->iop) 2384 inode->i_op = p->iop; 2385 if (p->fop) 2386 inode->i_fop = p->fop; 2387 ei->op = p->op; 2388 d_set_d_op(dentry, &pid_dentry_operations); 2389 d_add(dentry, inode); 2390 /* Close the race of the process dying before we return the dentry */ 2391 if (pid_revalidate(dentry, 0)) 2392 return 0; 2393 out: 2394 return -ENOENT; 2395 } 2396 2397 static struct dentry *proc_pident_lookup(struct inode *dir, 2398 struct dentry *dentry, 2399 const struct pid_entry *ents, 2400 unsigned int nents) 2401 { 2402 int error; 2403 struct task_struct *task = get_proc_task(dir); 2404 const struct pid_entry *p, *last; 2405 2406 error = -ENOENT; 2407 2408 if (!task) 2409 goto out_no_task; 2410 2411 /* 2412 * Yes, it does not scale. And it should not. Don't add 2413 * new entries into /proc/<tgid>/ without very good reasons. 2414 */ 2415 last = &ents[nents]; 2416 for (p = ents; p < last; p++) { 2417 if (p->len != dentry->d_name.len) 2418 continue; 2419 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2420 break; 2421 } 2422 if (p >= last) 2423 goto out; 2424 2425 error = proc_pident_instantiate(dir, dentry, task, p); 2426 out: 2427 put_task_struct(task); 2428 out_no_task: 2429 return ERR_PTR(error); 2430 } 2431 2432 static int proc_pident_readdir(struct file *file, struct dir_context *ctx, 2433 const struct pid_entry *ents, unsigned int nents) 2434 { 2435 struct task_struct *task = get_proc_task(file_inode(file)); 2436 const struct pid_entry *p; 2437 2438 if (!task) 2439 return -ENOENT; 2440 2441 if (!dir_emit_dots(file, ctx)) 2442 goto out; 2443 2444 if (ctx->pos >= nents + 2) 2445 goto out; 2446 2447 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) { 2448 if (!proc_fill_cache(file, ctx, p->name, p->len, 2449 proc_pident_instantiate, task, p)) 2450 break; 2451 ctx->pos++; 2452 } 2453 out: 2454 put_task_struct(task); 2455 return 0; 2456 } 2457 2458 #ifdef CONFIG_SECURITY 2459 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2460 size_t count, loff_t *ppos) 2461 { 2462 struct inode * inode = file_inode(file); 2463 char *p = NULL; 2464 ssize_t length; 2465 struct task_struct *task = get_proc_task(inode); 2466 2467 if (!task) 2468 return -ESRCH; 2469 2470 length = security_getprocattr(task, 2471 (char*)file->f_path.dentry->d_name.name, 2472 &p); 2473 put_task_struct(task); 2474 if (length > 0) 2475 length = simple_read_from_buffer(buf, count, ppos, p, length); 2476 kfree(p); 2477 return length; 2478 } 2479 2480 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2481 size_t count, loff_t *ppos) 2482 { 2483 struct inode * inode = file_inode(file); 2484 void *page; 2485 ssize_t length; 2486 struct task_struct *task = get_proc_task(inode); 2487 2488 length = -ESRCH; 2489 if (!task) 2490 goto out_no_task; 2491 if (count > PAGE_SIZE) 2492 count = PAGE_SIZE; 2493 2494 /* No partial writes. */ 2495 length = -EINVAL; 2496 if (*ppos != 0) 2497 goto out; 2498 2499 page = memdup_user(buf, count); 2500 if (IS_ERR(page)) { 2501 length = PTR_ERR(page); 2502 goto out; 2503 } 2504 2505 /* Guard against adverse ptrace interaction */ 2506 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex); 2507 if (length < 0) 2508 goto out_free; 2509 2510 length = security_setprocattr(task, 2511 (char*)file->f_path.dentry->d_name.name, 2512 page, count); 2513 mutex_unlock(&task->signal->cred_guard_mutex); 2514 out_free: 2515 kfree(page); 2516 out: 2517 put_task_struct(task); 2518 out_no_task: 2519 return length; 2520 } 2521 2522 static const struct file_operations proc_pid_attr_operations = { 2523 .read = proc_pid_attr_read, 2524 .write = proc_pid_attr_write, 2525 .llseek = generic_file_llseek, 2526 }; 2527 2528 static const struct pid_entry attr_dir_stuff[] = { 2529 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2530 REG("prev", S_IRUGO, proc_pid_attr_operations), 2531 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2532 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2533 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2534 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2535 }; 2536 2537 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx) 2538 { 2539 return proc_pident_readdir(file, ctx, 2540 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2541 } 2542 2543 static const struct file_operations proc_attr_dir_operations = { 2544 .read = generic_read_dir, 2545 .iterate_shared = proc_attr_dir_readdir, 2546 .llseek = generic_file_llseek, 2547 }; 2548 2549 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2550 struct dentry *dentry, unsigned int flags) 2551 { 2552 return proc_pident_lookup(dir, dentry, 2553 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2554 } 2555 2556 static const struct inode_operations proc_attr_dir_inode_operations = { 2557 .lookup = proc_attr_dir_lookup, 2558 .getattr = pid_getattr, 2559 .setattr = proc_setattr, 2560 }; 2561 2562 #endif 2563 2564 #ifdef CONFIG_ELF_CORE 2565 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2566 size_t count, loff_t *ppos) 2567 { 2568 struct task_struct *task = get_proc_task(file_inode(file)); 2569 struct mm_struct *mm; 2570 char buffer[PROC_NUMBUF]; 2571 size_t len; 2572 int ret; 2573 2574 if (!task) 2575 return -ESRCH; 2576 2577 ret = 0; 2578 mm = get_task_mm(task); 2579 if (mm) { 2580 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2581 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2582 MMF_DUMP_FILTER_SHIFT)); 2583 mmput(mm); 2584 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2585 } 2586 2587 put_task_struct(task); 2588 2589 return ret; 2590 } 2591 2592 static ssize_t proc_coredump_filter_write(struct file *file, 2593 const char __user *buf, 2594 size_t count, 2595 loff_t *ppos) 2596 { 2597 struct task_struct *task; 2598 struct mm_struct *mm; 2599 unsigned int val; 2600 int ret; 2601 int i; 2602 unsigned long mask; 2603 2604 ret = kstrtouint_from_user(buf, count, 0, &val); 2605 if (ret < 0) 2606 return ret; 2607 2608 ret = -ESRCH; 2609 task = get_proc_task(file_inode(file)); 2610 if (!task) 2611 goto out_no_task; 2612 2613 mm = get_task_mm(task); 2614 if (!mm) 2615 goto out_no_mm; 2616 ret = 0; 2617 2618 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2619 if (val & mask) 2620 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2621 else 2622 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2623 } 2624 2625 mmput(mm); 2626 out_no_mm: 2627 put_task_struct(task); 2628 out_no_task: 2629 if (ret < 0) 2630 return ret; 2631 return count; 2632 } 2633 2634 static const struct file_operations proc_coredump_filter_operations = { 2635 .read = proc_coredump_filter_read, 2636 .write = proc_coredump_filter_write, 2637 .llseek = generic_file_llseek, 2638 }; 2639 #endif 2640 2641 #ifdef CONFIG_TASK_IO_ACCOUNTING 2642 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole) 2643 { 2644 struct task_io_accounting acct = task->ioac; 2645 unsigned long flags; 2646 int result; 2647 2648 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2649 if (result) 2650 return result; 2651 2652 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { 2653 result = -EACCES; 2654 goto out_unlock; 2655 } 2656 2657 if (whole && lock_task_sighand(task, &flags)) { 2658 struct task_struct *t = task; 2659 2660 task_io_accounting_add(&acct, &task->signal->ioac); 2661 while_each_thread(task, t) 2662 task_io_accounting_add(&acct, &t->ioac); 2663 2664 unlock_task_sighand(task, &flags); 2665 } 2666 seq_printf(m, 2667 "rchar: %llu\n" 2668 "wchar: %llu\n" 2669 "syscr: %llu\n" 2670 "syscw: %llu\n" 2671 "read_bytes: %llu\n" 2672 "write_bytes: %llu\n" 2673 "cancelled_write_bytes: %llu\n", 2674 (unsigned long long)acct.rchar, 2675 (unsigned long long)acct.wchar, 2676 (unsigned long long)acct.syscr, 2677 (unsigned long long)acct.syscw, 2678 (unsigned long long)acct.read_bytes, 2679 (unsigned long long)acct.write_bytes, 2680 (unsigned long long)acct.cancelled_write_bytes); 2681 result = 0; 2682 2683 out_unlock: 2684 mutex_unlock(&task->signal->cred_guard_mutex); 2685 return result; 2686 } 2687 2688 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2689 struct pid *pid, struct task_struct *task) 2690 { 2691 return do_io_accounting(task, m, 0); 2692 } 2693 2694 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2695 struct pid *pid, struct task_struct *task) 2696 { 2697 return do_io_accounting(task, m, 1); 2698 } 2699 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2700 2701 #ifdef CONFIG_USER_NS 2702 static int proc_id_map_open(struct inode *inode, struct file *file, 2703 const struct seq_operations *seq_ops) 2704 { 2705 struct user_namespace *ns = NULL; 2706 struct task_struct *task; 2707 struct seq_file *seq; 2708 int ret = -EINVAL; 2709 2710 task = get_proc_task(inode); 2711 if (task) { 2712 rcu_read_lock(); 2713 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2714 rcu_read_unlock(); 2715 put_task_struct(task); 2716 } 2717 if (!ns) 2718 goto err; 2719 2720 ret = seq_open(file, seq_ops); 2721 if (ret) 2722 goto err_put_ns; 2723 2724 seq = file->private_data; 2725 seq->private = ns; 2726 2727 return 0; 2728 err_put_ns: 2729 put_user_ns(ns); 2730 err: 2731 return ret; 2732 } 2733 2734 static int proc_id_map_release(struct inode *inode, struct file *file) 2735 { 2736 struct seq_file *seq = file->private_data; 2737 struct user_namespace *ns = seq->private; 2738 put_user_ns(ns); 2739 return seq_release(inode, file); 2740 } 2741 2742 static int proc_uid_map_open(struct inode *inode, struct file *file) 2743 { 2744 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2745 } 2746 2747 static int proc_gid_map_open(struct inode *inode, struct file *file) 2748 { 2749 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2750 } 2751 2752 static int proc_projid_map_open(struct inode *inode, struct file *file) 2753 { 2754 return proc_id_map_open(inode, file, &proc_projid_seq_operations); 2755 } 2756 2757 static const struct file_operations proc_uid_map_operations = { 2758 .open = proc_uid_map_open, 2759 .write = proc_uid_map_write, 2760 .read = seq_read, 2761 .llseek = seq_lseek, 2762 .release = proc_id_map_release, 2763 }; 2764 2765 static const struct file_operations proc_gid_map_operations = { 2766 .open = proc_gid_map_open, 2767 .write = proc_gid_map_write, 2768 .read = seq_read, 2769 .llseek = seq_lseek, 2770 .release = proc_id_map_release, 2771 }; 2772 2773 static const struct file_operations proc_projid_map_operations = { 2774 .open = proc_projid_map_open, 2775 .write = proc_projid_map_write, 2776 .read = seq_read, 2777 .llseek = seq_lseek, 2778 .release = proc_id_map_release, 2779 }; 2780 2781 static int proc_setgroups_open(struct inode *inode, struct file *file) 2782 { 2783 struct user_namespace *ns = NULL; 2784 struct task_struct *task; 2785 int ret; 2786 2787 ret = -ESRCH; 2788 task = get_proc_task(inode); 2789 if (task) { 2790 rcu_read_lock(); 2791 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2792 rcu_read_unlock(); 2793 put_task_struct(task); 2794 } 2795 if (!ns) 2796 goto err; 2797 2798 if (file->f_mode & FMODE_WRITE) { 2799 ret = -EACCES; 2800 if (!ns_capable(ns, CAP_SYS_ADMIN)) 2801 goto err_put_ns; 2802 } 2803 2804 ret = single_open(file, &proc_setgroups_show, ns); 2805 if (ret) 2806 goto err_put_ns; 2807 2808 return 0; 2809 err_put_ns: 2810 put_user_ns(ns); 2811 err: 2812 return ret; 2813 } 2814 2815 static int proc_setgroups_release(struct inode *inode, struct file *file) 2816 { 2817 struct seq_file *seq = file->private_data; 2818 struct user_namespace *ns = seq->private; 2819 int ret = single_release(inode, file); 2820 put_user_ns(ns); 2821 return ret; 2822 } 2823 2824 static const struct file_operations proc_setgroups_operations = { 2825 .open = proc_setgroups_open, 2826 .write = proc_setgroups_write, 2827 .read = seq_read, 2828 .llseek = seq_lseek, 2829 .release = proc_setgroups_release, 2830 }; 2831 #endif /* CONFIG_USER_NS */ 2832 2833 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2834 struct pid *pid, struct task_struct *task) 2835 { 2836 int err = lock_trace(task); 2837 if (!err) { 2838 seq_printf(m, "%08x\n", task->personality); 2839 unlock_trace(task); 2840 } 2841 return err; 2842 } 2843 2844 /* 2845 * Thread groups 2846 */ 2847 static const struct file_operations proc_task_operations; 2848 static const struct inode_operations proc_task_inode_operations; 2849 2850 static const struct pid_entry tgid_base_stuff[] = { 2851 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2852 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2853 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 2854 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2855 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2856 #ifdef CONFIG_NET 2857 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2858 #endif 2859 REG("environ", S_IRUSR, proc_environ_operations), 2860 REG("auxv", S_IRUSR, proc_auxv_operations), 2861 ONE("status", S_IRUGO, proc_pid_status), 2862 ONE("personality", S_IRUSR, proc_pid_personality), 2863 ONE("limits", S_IRUGO, proc_pid_limits), 2864 #ifdef CONFIG_SCHED_DEBUG 2865 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2866 #endif 2867 #ifdef CONFIG_SCHED_AUTOGROUP 2868 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2869 #endif 2870 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2871 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2872 ONE("syscall", S_IRUSR, proc_pid_syscall), 2873 #endif 2874 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 2875 ONE("stat", S_IRUGO, proc_tgid_stat), 2876 ONE("statm", S_IRUGO, proc_pid_statm), 2877 REG("maps", S_IRUGO, proc_pid_maps_operations), 2878 #ifdef CONFIG_NUMA 2879 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 2880 #endif 2881 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2882 LNK("cwd", proc_cwd_link), 2883 LNK("root", proc_root_link), 2884 LNK("exe", proc_exe_link), 2885 REG("mounts", S_IRUGO, proc_mounts_operations), 2886 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2887 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2888 #ifdef CONFIG_PROC_PAGE_MONITOR 2889 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2890 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 2891 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2892 #endif 2893 #ifdef CONFIG_SECURITY 2894 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2895 #endif 2896 #ifdef CONFIG_KALLSYMS 2897 ONE("wchan", S_IRUGO, proc_pid_wchan), 2898 #endif 2899 #ifdef CONFIG_STACKTRACE 2900 ONE("stack", S_IRUSR, proc_pid_stack), 2901 #endif 2902 #ifdef CONFIG_SCHED_INFO 2903 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 2904 #endif 2905 #ifdef CONFIG_LATENCYTOP 2906 REG("latency", S_IRUGO, proc_lstats_operations), 2907 #endif 2908 #ifdef CONFIG_PROC_PID_CPUSET 2909 ONE("cpuset", S_IRUGO, proc_cpuset_show), 2910 #endif 2911 #ifdef CONFIG_CGROUPS 2912 ONE("cgroup", S_IRUGO, proc_cgroup_show), 2913 #endif 2914 ONE("oom_score", S_IRUGO, proc_oom_score), 2915 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 2916 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2917 #ifdef CONFIG_AUDITSYSCALL 2918 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2919 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2920 #endif 2921 #ifdef CONFIG_FAULT_INJECTION 2922 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2923 #endif 2924 #ifdef CONFIG_ELF_CORE 2925 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2926 #endif 2927 #ifdef CONFIG_TASK_IO_ACCOUNTING 2928 ONE("io", S_IRUSR, proc_tgid_io_accounting), 2929 #endif 2930 #ifdef CONFIG_HARDWALL 2931 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 2932 #endif 2933 #ifdef CONFIG_USER_NS 2934 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 2935 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 2936 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 2937 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 2938 #endif 2939 #ifdef CONFIG_CHECKPOINT_RESTORE 2940 REG("timers", S_IRUGO, proc_timers_operations), 2941 #endif 2942 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations), 2943 }; 2944 2945 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) 2946 { 2947 return proc_pident_readdir(file, ctx, 2948 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2949 } 2950 2951 static const struct file_operations proc_tgid_base_operations = { 2952 .read = generic_read_dir, 2953 .iterate_shared = proc_tgid_base_readdir, 2954 .llseek = generic_file_llseek, 2955 }; 2956 2957 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 2958 { 2959 return proc_pident_lookup(dir, dentry, 2960 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2961 } 2962 2963 static const struct inode_operations proc_tgid_base_inode_operations = { 2964 .lookup = proc_tgid_base_lookup, 2965 .getattr = pid_getattr, 2966 .setattr = proc_setattr, 2967 .permission = proc_pid_permission, 2968 }; 2969 2970 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2971 { 2972 struct dentry *dentry, *leader, *dir; 2973 char buf[PROC_NUMBUF]; 2974 struct qstr name; 2975 2976 name.name = buf; 2977 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2978 /* no ->d_hash() rejects on procfs */ 2979 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2980 if (dentry) { 2981 d_invalidate(dentry); 2982 dput(dentry); 2983 } 2984 2985 if (pid == tgid) 2986 return; 2987 2988 name.name = buf; 2989 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2990 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2991 if (!leader) 2992 goto out; 2993 2994 name.name = "task"; 2995 name.len = strlen(name.name); 2996 dir = d_hash_and_lookup(leader, &name); 2997 if (!dir) 2998 goto out_put_leader; 2999 3000 name.name = buf; 3001 name.len = snprintf(buf, sizeof(buf), "%d", pid); 3002 dentry = d_hash_and_lookup(dir, &name); 3003 if (dentry) { 3004 d_invalidate(dentry); 3005 dput(dentry); 3006 } 3007 3008 dput(dir); 3009 out_put_leader: 3010 dput(leader); 3011 out: 3012 return; 3013 } 3014 3015 /** 3016 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 3017 * @task: task that should be flushed. 3018 * 3019 * When flushing dentries from proc, one needs to flush them from global 3020 * proc (proc_mnt) and from all the namespaces' procs this task was seen 3021 * in. This call is supposed to do all of this job. 3022 * 3023 * Looks in the dcache for 3024 * /proc/@pid 3025 * /proc/@tgid/task/@pid 3026 * if either directory is present flushes it and all of it'ts children 3027 * from the dcache. 3028 * 3029 * It is safe and reasonable to cache /proc entries for a task until 3030 * that task exits. After that they just clog up the dcache with 3031 * useless entries, possibly causing useful dcache entries to be 3032 * flushed instead. This routine is proved to flush those useless 3033 * dcache entries at process exit time. 3034 * 3035 * NOTE: This routine is just an optimization so it does not guarantee 3036 * that no dcache entries will exist at process exit time it 3037 * just makes it very unlikely that any will persist. 3038 */ 3039 3040 void proc_flush_task(struct task_struct *task) 3041 { 3042 int i; 3043 struct pid *pid, *tgid; 3044 struct upid *upid; 3045 3046 pid = task_pid(task); 3047 tgid = task_tgid(task); 3048 3049 for (i = 0; i <= pid->level; i++) { 3050 upid = &pid->numbers[i]; 3051 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3052 tgid->numbers[i].nr); 3053 } 3054 } 3055 3056 static int proc_pid_instantiate(struct inode *dir, 3057 struct dentry * dentry, 3058 struct task_struct *task, const void *ptr) 3059 { 3060 struct inode *inode; 3061 3062 inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3063 if (!inode) 3064 goto out; 3065 3066 inode->i_op = &proc_tgid_base_inode_operations; 3067 inode->i_fop = &proc_tgid_base_operations; 3068 inode->i_flags|=S_IMMUTABLE; 3069 3070 set_nlink(inode, nlink_tgid); 3071 3072 d_set_d_op(dentry, &pid_dentry_operations); 3073 3074 d_add(dentry, inode); 3075 /* Close the race of the process dying before we return the dentry */ 3076 if (pid_revalidate(dentry, 0)) 3077 return 0; 3078 out: 3079 return -ENOENT; 3080 } 3081 3082 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3083 { 3084 int result = -ENOENT; 3085 struct task_struct *task; 3086 unsigned tgid; 3087 struct pid_namespace *ns; 3088 3089 tgid = name_to_int(&dentry->d_name); 3090 if (tgid == ~0U) 3091 goto out; 3092 3093 ns = dentry->d_sb->s_fs_info; 3094 rcu_read_lock(); 3095 task = find_task_by_pid_ns(tgid, ns); 3096 if (task) 3097 get_task_struct(task); 3098 rcu_read_unlock(); 3099 if (!task) 3100 goto out; 3101 3102 result = proc_pid_instantiate(dir, dentry, task, NULL); 3103 put_task_struct(task); 3104 out: 3105 return ERR_PTR(result); 3106 } 3107 3108 /* 3109 * Find the first task with tgid >= tgid 3110 * 3111 */ 3112 struct tgid_iter { 3113 unsigned int tgid; 3114 struct task_struct *task; 3115 }; 3116 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3117 { 3118 struct pid *pid; 3119 3120 if (iter.task) 3121 put_task_struct(iter.task); 3122 rcu_read_lock(); 3123 retry: 3124 iter.task = NULL; 3125 pid = find_ge_pid(iter.tgid, ns); 3126 if (pid) { 3127 iter.tgid = pid_nr_ns(pid, ns); 3128 iter.task = pid_task(pid, PIDTYPE_PID); 3129 /* What we to know is if the pid we have find is the 3130 * pid of a thread_group_leader. Testing for task 3131 * being a thread_group_leader is the obvious thing 3132 * todo but there is a window when it fails, due to 3133 * the pid transfer logic in de_thread. 3134 * 3135 * So we perform the straight forward test of seeing 3136 * if the pid we have found is the pid of a thread 3137 * group leader, and don't worry if the task we have 3138 * found doesn't happen to be a thread group leader. 3139 * As we don't care in the case of readdir. 3140 */ 3141 if (!iter.task || !has_group_leader_pid(iter.task)) { 3142 iter.tgid += 1; 3143 goto retry; 3144 } 3145 get_task_struct(iter.task); 3146 } 3147 rcu_read_unlock(); 3148 return iter; 3149 } 3150 3151 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2) 3152 3153 /* for the /proc/ directory itself, after non-process stuff has been done */ 3154 int proc_pid_readdir(struct file *file, struct dir_context *ctx) 3155 { 3156 struct tgid_iter iter; 3157 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info; 3158 loff_t pos = ctx->pos; 3159 3160 if (pos >= PID_MAX_LIMIT + TGID_OFFSET) 3161 return 0; 3162 3163 if (pos == TGID_OFFSET - 2) { 3164 struct inode *inode = d_inode(ns->proc_self); 3165 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) 3166 return 0; 3167 ctx->pos = pos = pos + 1; 3168 } 3169 if (pos == TGID_OFFSET - 1) { 3170 struct inode *inode = d_inode(ns->proc_thread_self); 3171 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) 3172 return 0; 3173 ctx->pos = pos = pos + 1; 3174 } 3175 iter.tgid = pos - TGID_OFFSET; 3176 iter.task = NULL; 3177 for (iter = next_tgid(ns, iter); 3178 iter.task; 3179 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3180 char name[PROC_NUMBUF]; 3181 int len; 3182 if (!has_pid_permissions(ns, iter.task, 2)) 3183 continue; 3184 3185 len = snprintf(name, sizeof(name), "%d", iter.tgid); 3186 ctx->pos = iter.tgid + TGID_OFFSET; 3187 if (!proc_fill_cache(file, ctx, name, len, 3188 proc_pid_instantiate, iter.task, NULL)) { 3189 put_task_struct(iter.task); 3190 return 0; 3191 } 3192 } 3193 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET; 3194 return 0; 3195 } 3196 3197 /* 3198 * proc_tid_comm_permission is a special permission function exclusively 3199 * used for the node /proc/<pid>/task/<tid>/comm. 3200 * It bypasses generic permission checks in the case where a task of the same 3201 * task group attempts to access the node. 3202 * The rationale behind this is that glibc and bionic access this node for 3203 * cross thread naming (pthread_set/getname_np(!self)). However, if 3204 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0, 3205 * which locks out the cross thread naming implementation. 3206 * This function makes sure that the node is always accessible for members of 3207 * same thread group. 3208 */ 3209 static int proc_tid_comm_permission(struct inode *inode, int mask) 3210 { 3211 bool is_same_tgroup; 3212 struct task_struct *task; 3213 3214 task = get_proc_task(inode); 3215 if (!task) 3216 return -ESRCH; 3217 is_same_tgroup = same_thread_group(current, task); 3218 put_task_struct(task); 3219 3220 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) { 3221 /* This file (/proc/<pid>/task/<tid>/comm) can always be 3222 * read or written by the members of the corresponding 3223 * thread group. 3224 */ 3225 return 0; 3226 } 3227 3228 return generic_permission(inode, mask); 3229 } 3230 3231 static const struct inode_operations proc_tid_comm_inode_operations = { 3232 .permission = proc_tid_comm_permission, 3233 }; 3234 3235 /* 3236 * Tasks 3237 */ 3238 static const struct pid_entry tid_base_stuff[] = { 3239 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3240 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3241 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3242 #ifdef CONFIG_NET 3243 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3244 #endif 3245 REG("environ", S_IRUSR, proc_environ_operations), 3246 REG("auxv", S_IRUSR, proc_auxv_operations), 3247 ONE("status", S_IRUGO, proc_pid_status), 3248 ONE("personality", S_IRUSR, proc_pid_personality), 3249 ONE("limits", S_IRUGO, proc_pid_limits), 3250 #ifdef CONFIG_SCHED_DEBUG 3251 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3252 #endif 3253 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR, 3254 &proc_tid_comm_inode_operations, 3255 &proc_pid_set_comm_operations, {}), 3256 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3257 ONE("syscall", S_IRUSR, proc_pid_syscall), 3258 #endif 3259 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 3260 ONE("stat", S_IRUGO, proc_tid_stat), 3261 ONE("statm", S_IRUGO, proc_pid_statm), 3262 REG("maps", S_IRUGO, proc_tid_maps_operations), 3263 #ifdef CONFIG_PROC_CHILDREN 3264 REG("children", S_IRUGO, proc_tid_children_operations), 3265 #endif 3266 #ifdef CONFIG_NUMA 3267 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations), 3268 #endif 3269 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3270 LNK("cwd", proc_cwd_link), 3271 LNK("root", proc_root_link), 3272 LNK("exe", proc_exe_link), 3273 REG("mounts", S_IRUGO, proc_mounts_operations), 3274 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3275 #ifdef CONFIG_PROC_PAGE_MONITOR 3276 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3277 REG("smaps", S_IRUGO, proc_tid_smaps_operations), 3278 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3279 #endif 3280 #ifdef CONFIG_SECURITY 3281 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3282 #endif 3283 #ifdef CONFIG_KALLSYMS 3284 ONE("wchan", S_IRUGO, proc_pid_wchan), 3285 #endif 3286 #ifdef CONFIG_STACKTRACE 3287 ONE("stack", S_IRUSR, proc_pid_stack), 3288 #endif 3289 #ifdef CONFIG_SCHED_INFO 3290 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 3291 #endif 3292 #ifdef CONFIG_LATENCYTOP 3293 REG("latency", S_IRUGO, proc_lstats_operations), 3294 #endif 3295 #ifdef CONFIG_PROC_PID_CPUSET 3296 ONE("cpuset", S_IRUGO, proc_cpuset_show), 3297 #endif 3298 #ifdef CONFIG_CGROUPS 3299 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3300 #endif 3301 ONE("oom_score", S_IRUGO, proc_oom_score), 3302 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3303 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3304 #ifdef CONFIG_AUDITSYSCALL 3305 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3306 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3307 #endif 3308 #ifdef CONFIG_FAULT_INJECTION 3309 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3310 #endif 3311 #ifdef CONFIG_TASK_IO_ACCOUNTING 3312 ONE("io", S_IRUSR, proc_tid_io_accounting), 3313 #endif 3314 #ifdef CONFIG_HARDWALL 3315 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 3316 #endif 3317 #ifdef CONFIG_USER_NS 3318 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3319 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3320 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3321 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3322 #endif 3323 }; 3324 3325 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx) 3326 { 3327 return proc_pident_readdir(file, ctx, 3328 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3329 } 3330 3331 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3332 { 3333 return proc_pident_lookup(dir, dentry, 3334 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3335 } 3336 3337 static const struct file_operations proc_tid_base_operations = { 3338 .read = generic_read_dir, 3339 .iterate_shared = proc_tid_base_readdir, 3340 .llseek = generic_file_llseek, 3341 }; 3342 3343 static const struct inode_operations proc_tid_base_inode_operations = { 3344 .lookup = proc_tid_base_lookup, 3345 .getattr = pid_getattr, 3346 .setattr = proc_setattr, 3347 }; 3348 3349 static int proc_task_instantiate(struct inode *dir, 3350 struct dentry *dentry, struct task_struct *task, const void *ptr) 3351 { 3352 struct inode *inode; 3353 inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3354 3355 if (!inode) 3356 goto out; 3357 inode->i_op = &proc_tid_base_inode_operations; 3358 inode->i_fop = &proc_tid_base_operations; 3359 inode->i_flags|=S_IMMUTABLE; 3360 3361 set_nlink(inode, nlink_tid); 3362 3363 d_set_d_op(dentry, &pid_dentry_operations); 3364 3365 d_add(dentry, inode); 3366 /* Close the race of the process dying before we return the dentry */ 3367 if (pid_revalidate(dentry, 0)) 3368 return 0; 3369 out: 3370 return -ENOENT; 3371 } 3372 3373 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3374 { 3375 int result = -ENOENT; 3376 struct task_struct *task; 3377 struct task_struct *leader = get_proc_task(dir); 3378 unsigned tid; 3379 struct pid_namespace *ns; 3380 3381 if (!leader) 3382 goto out_no_task; 3383 3384 tid = name_to_int(&dentry->d_name); 3385 if (tid == ~0U) 3386 goto out; 3387 3388 ns = dentry->d_sb->s_fs_info; 3389 rcu_read_lock(); 3390 task = find_task_by_pid_ns(tid, ns); 3391 if (task) 3392 get_task_struct(task); 3393 rcu_read_unlock(); 3394 if (!task) 3395 goto out; 3396 if (!same_thread_group(leader, task)) 3397 goto out_drop_task; 3398 3399 result = proc_task_instantiate(dir, dentry, task, NULL); 3400 out_drop_task: 3401 put_task_struct(task); 3402 out: 3403 put_task_struct(leader); 3404 out_no_task: 3405 return ERR_PTR(result); 3406 } 3407 3408 /* 3409 * Find the first tid of a thread group to return to user space. 3410 * 3411 * Usually this is just the thread group leader, but if the users 3412 * buffer was too small or there was a seek into the middle of the 3413 * directory we have more work todo. 3414 * 3415 * In the case of a short read we start with find_task_by_pid. 3416 * 3417 * In the case of a seek we start with the leader and walk nr 3418 * threads past it. 3419 */ 3420 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos, 3421 struct pid_namespace *ns) 3422 { 3423 struct task_struct *pos, *task; 3424 unsigned long nr = f_pos; 3425 3426 if (nr != f_pos) /* 32bit overflow? */ 3427 return NULL; 3428 3429 rcu_read_lock(); 3430 task = pid_task(pid, PIDTYPE_PID); 3431 if (!task) 3432 goto fail; 3433 3434 /* Attempt to start with the tid of a thread */ 3435 if (tid && nr) { 3436 pos = find_task_by_pid_ns(tid, ns); 3437 if (pos && same_thread_group(pos, task)) 3438 goto found; 3439 } 3440 3441 /* If nr exceeds the number of threads there is nothing todo */ 3442 if (nr >= get_nr_threads(task)) 3443 goto fail; 3444 3445 /* If we haven't found our starting place yet start 3446 * with the leader and walk nr threads forward. 3447 */ 3448 pos = task = task->group_leader; 3449 do { 3450 if (!nr--) 3451 goto found; 3452 } while_each_thread(task, pos); 3453 fail: 3454 pos = NULL; 3455 goto out; 3456 found: 3457 get_task_struct(pos); 3458 out: 3459 rcu_read_unlock(); 3460 return pos; 3461 } 3462 3463 /* 3464 * Find the next thread in the thread list. 3465 * Return NULL if there is an error or no next thread. 3466 * 3467 * The reference to the input task_struct is released. 3468 */ 3469 static struct task_struct *next_tid(struct task_struct *start) 3470 { 3471 struct task_struct *pos = NULL; 3472 rcu_read_lock(); 3473 if (pid_alive(start)) { 3474 pos = next_thread(start); 3475 if (thread_group_leader(pos)) 3476 pos = NULL; 3477 else 3478 get_task_struct(pos); 3479 } 3480 rcu_read_unlock(); 3481 put_task_struct(start); 3482 return pos; 3483 } 3484 3485 /* for the /proc/TGID/task/ directories */ 3486 static int proc_task_readdir(struct file *file, struct dir_context *ctx) 3487 { 3488 struct inode *inode = file_inode(file); 3489 struct task_struct *task; 3490 struct pid_namespace *ns; 3491 int tid; 3492 3493 if (proc_inode_is_dead(inode)) 3494 return -ENOENT; 3495 3496 if (!dir_emit_dots(file, ctx)) 3497 return 0; 3498 3499 /* f_version caches the tgid value that the last readdir call couldn't 3500 * return. lseek aka telldir automagically resets f_version to 0. 3501 */ 3502 ns = inode->i_sb->s_fs_info; 3503 tid = (int)file->f_version; 3504 file->f_version = 0; 3505 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); 3506 task; 3507 task = next_tid(task), ctx->pos++) { 3508 char name[PROC_NUMBUF]; 3509 int len; 3510 tid = task_pid_nr_ns(task, ns); 3511 len = snprintf(name, sizeof(name), "%d", tid); 3512 if (!proc_fill_cache(file, ctx, name, len, 3513 proc_task_instantiate, task, NULL)) { 3514 /* returning this tgid failed, save it as the first 3515 * pid for the next readir call */ 3516 file->f_version = (u64)tid; 3517 put_task_struct(task); 3518 break; 3519 } 3520 } 3521 3522 return 0; 3523 } 3524 3525 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3526 { 3527 struct inode *inode = d_inode(dentry); 3528 struct task_struct *p = get_proc_task(inode); 3529 generic_fillattr(inode, stat); 3530 3531 if (p) { 3532 stat->nlink += get_nr_threads(p); 3533 put_task_struct(p); 3534 } 3535 3536 return 0; 3537 } 3538 3539 static const struct inode_operations proc_task_inode_operations = { 3540 .lookup = proc_task_lookup, 3541 .getattr = proc_task_getattr, 3542 .setattr = proc_setattr, 3543 .permission = proc_pid_permission, 3544 }; 3545 3546 static const struct file_operations proc_task_operations = { 3547 .read = generic_read_dir, 3548 .iterate_shared = proc_task_readdir, 3549 .llseek = generic_file_llseek, 3550 }; 3551 3552 void __init set_proc_pid_nlink(void) 3553 { 3554 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3555 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3556 } 3557