1 /* 2 * linux/fs/proc/base.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 * 6 * proc base directory handling functions 7 * 8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part. 9 * Instead of using magical inumbers to determine the kind of object 10 * we allocate and fill in-core inodes upon lookup. They don't even 11 * go into icache. We cache the reference to task_struct upon lookup too. 12 * Eventually it should become a filesystem in its own. We don't use the 13 * rest of procfs anymore. 14 * 15 * 16 * Changelog: 17 * 17-Jan-2005 18 * Allan Bezerra 19 * Bruna Moreira <bruna.moreira@indt.org.br> 20 * Edjard Mota <edjard.mota@indt.org.br> 21 * Ilias Biris <ilias.biris@indt.org.br> 22 * Mauricio Lin <mauricio.lin@indt.org.br> 23 * 24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 25 * 26 * A new process specific entry (smaps) included in /proc. It shows the 27 * size of rss for each memory area. The maps entry lacks information 28 * about physical memory size (rss) for each mapped file, i.e., 29 * rss information for executables and library files. 30 * This additional information is useful for any tools that need to know 31 * about physical memory consumption for a process specific library. 32 * 33 * Changelog: 34 * 21-Feb-2005 35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 36 * Pud inclusion in the page table walking. 37 * 38 * ChangeLog: 39 * 10-Mar-2005 40 * 10LE Instituto Nokia de Tecnologia - INdT: 41 * A better way to walks through the page table as suggested by Hugh Dickins. 42 * 43 * Simo Piiroinen <simo.piiroinen@nokia.com>: 44 * Smaps information related to shared, private, clean and dirty pages. 45 * 46 * Paul Mundt <paul.mundt@nokia.com>: 47 * Overall revision about smaps. 48 */ 49 50 #include <asm/uaccess.h> 51 52 #include <linux/errno.h> 53 #include <linux/time.h> 54 #include <linux/proc_fs.h> 55 #include <linux/stat.h> 56 #include <linux/task_io_accounting_ops.h> 57 #include <linux/init.h> 58 #include <linux/capability.h> 59 #include <linux/file.h> 60 #include <linux/fdtable.h> 61 #include <linux/string.h> 62 #include <linux/seq_file.h> 63 #include <linux/namei.h> 64 #include <linux/mnt_namespace.h> 65 #include <linux/mm.h> 66 #include <linux/swap.h> 67 #include <linux/rcupdate.h> 68 #include <linux/kallsyms.h> 69 #include <linux/stacktrace.h> 70 #include <linux/resource.h> 71 #include <linux/module.h> 72 #include <linux/mount.h> 73 #include <linux/security.h> 74 #include <linux/ptrace.h> 75 #include <linux/tracehook.h> 76 #include <linux/printk.h> 77 #include <linux/cgroup.h> 78 #include <linux/cpuset.h> 79 #include <linux/audit.h> 80 #include <linux/poll.h> 81 #include <linux/nsproxy.h> 82 #include <linux/oom.h> 83 #include <linux/elf.h> 84 #include <linux/pid_namespace.h> 85 #include <linux/user_namespace.h> 86 #include <linux/fs_struct.h> 87 #include <linux/slab.h> 88 #include <linux/flex_array.h> 89 #include <linux/posix-timers.h> 90 #ifdef CONFIG_HARDWALL 91 #include <asm/hardwall.h> 92 #endif 93 #include <trace/events/oom.h> 94 #include "internal.h" 95 #include "fd.h" 96 97 /* NOTE: 98 * Implementing inode permission operations in /proc is almost 99 * certainly an error. Permission checks need to happen during 100 * each system call not at open time. The reason is that most of 101 * what we wish to check for permissions in /proc varies at runtime. 102 * 103 * The classic example of a problem is opening file descriptors 104 * in /proc for a task before it execs a suid executable. 105 */ 106 107 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 21 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, struct task_struct *task) 1671 { 1672 struct inode * inode; 1673 struct proc_inode *ei; 1674 const struct cred *cred; 1675 1676 /* We need a new inode */ 1677 1678 inode = new_inode(sb); 1679 if (!inode) 1680 goto out; 1681 1682 /* Common stuff */ 1683 ei = PROC_I(inode); 1684 inode->i_ino = get_next_ino(); 1685 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 1686 inode->i_op = &proc_def_inode_operations; 1687 1688 /* 1689 * grab the reference to task. 1690 */ 1691 ei->pid = get_task_pid(task, PIDTYPE_PID); 1692 if (!ei->pid) 1693 goto out_unlock; 1694 1695 if (task_dumpable(task)) { 1696 rcu_read_lock(); 1697 cred = __task_cred(task); 1698 inode->i_uid = cred->euid; 1699 inode->i_gid = cred->egid; 1700 rcu_read_unlock(); 1701 } 1702 security_task_to_inode(task, inode); 1703 1704 out: 1705 return inode; 1706 1707 out_unlock: 1708 iput(inode); 1709 return NULL; 1710 } 1711 1712 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1713 { 1714 struct inode *inode = d_inode(dentry); 1715 struct task_struct *task; 1716 const struct cred *cred; 1717 struct pid_namespace *pid = dentry->d_sb->s_fs_info; 1718 1719 generic_fillattr(inode, stat); 1720 1721 rcu_read_lock(); 1722 stat->uid = GLOBAL_ROOT_UID; 1723 stat->gid = GLOBAL_ROOT_GID; 1724 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1725 if (task) { 1726 if (!has_pid_permissions(pid, task, 2)) { 1727 rcu_read_unlock(); 1728 /* 1729 * This doesn't prevent learning whether PID exists, 1730 * it only makes getattr() consistent with readdir(). 1731 */ 1732 return -ENOENT; 1733 } 1734 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1735 task_dumpable(task)) { 1736 cred = __task_cred(task); 1737 stat->uid = cred->euid; 1738 stat->gid = cred->egid; 1739 } 1740 } 1741 rcu_read_unlock(); 1742 return 0; 1743 } 1744 1745 /* dentry stuff */ 1746 1747 /* 1748 * Exceptional case: normally we are not allowed to unhash a busy 1749 * directory. In this case, however, we can do it - no aliasing problems 1750 * due to the way we treat inodes. 1751 * 1752 * Rewrite the inode's ownerships here because the owning task may have 1753 * performed a setuid(), etc. 1754 * 1755 * Before the /proc/pid/status file was created the only way to read 1756 * the effective uid of a /process was to stat /proc/pid. Reading 1757 * /proc/pid/status is slow enough that procps and other packages 1758 * kept stating /proc/pid. To keep the rules in /proc simple I have 1759 * made this apply to all per process world readable and executable 1760 * directories. 1761 */ 1762 int pid_revalidate(struct dentry *dentry, unsigned int flags) 1763 { 1764 struct inode *inode; 1765 struct task_struct *task; 1766 const struct cred *cred; 1767 1768 if (flags & LOOKUP_RCU) 1769 return -ECHILD; 1770 1771 inode = d_inode(dentry); 1772 task = get_proc_task(inode); 1773 1774 if (task) { 1775 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1776 task_dumpable(task)) { 1777 rcu_read_lock(); 1778 cred = __task_cred(task); 1779 inode->i_uid = cred->euid; 1780 inode->i_gid = cred->egid; 1781 rcu_read_unlock(); 1782 } else { 1783 inode->i_uid = GLOBAL_ROOT_UID; 1784 inode->i_gid = GLOBAL_ROOT_GID; 1785 } 1786 inode->i_mode &= ~(S_ISUID | S_ISGID); 1787 security_task_to_inode(task, inode); 1788 put_task_struct(task); 1789 return 1; 1790 } 1791 return 0; 1792 } 1793 1794 static inline bool proc_inode_is_dead(struct inode *inode) 1795 { 1796 return !proc_pid(inode)->tasks[PIDTYPE_PID].first; 1797 } 1798 1799 int pid_delete_dentry(const struct dentry *dentry) 1800 { 1801 /* Is the task we represent dead? 1802 * If so, then don't put the dentry on the lru list, 1803 * kill it immediately. 1804 */ 1805 return proc_inode_is_dead(d_inode(dentry)); 1806 } 1807 1808 const struct dentry_operations pid_dentry_operations = 1809 { 1810 .d_revalidate = pid_revalidate, 1811 .d_delete = pid_delete_dentry, 1812 }; 1813 1814 /* Lookups */ 1815 1816 /* 1817 * Fill a directory entry. 1818 * 1819 * If possible create the dcache entry and derive our inode number and 1820 * file type from dcache entry. 1821 * 1822 * Since all of the proc inode numbers are dynamically generated, the inode 1823 * numbers do not exist until the inode is cache. This means creating the 1824 * the dcache entry in readdir is necessary to keep the inode numbers 1825 * reported by readdir in sync with the inode numbers reported 1826 * by stat. 1827 */ 1828 bool proc_fill_cache(struct file *file, struct dir_context *ctx, 1829 const char *name, int len, 1830 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1831 { 1832 struct dentry *child, *dir = file->f_path.dentry; 1833 struct qstr qname = QSTR_INIT(name, len); 1834 struct inode *inode; 1835 unsigned type; 1836 ino_t ino; 1837 1838 child = d_hash_and_lookup(dir, &qname); 1839 if (!child) { 1840 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 1841 child = d_alloc_parallel(dir, &qname, &wq); 1842 if (IS_ERR(child)) 1843 goto end_instantiate; 1844 if (d_in_lookup(child)) { 1845 int err = instantiate(d_inode(dir), child, task, ptr); 1846 d_lookup_done(child); 1847 if (err < 0) { 1848 dput(child); 1849 goto end_instantiate; 1850 } 1851 } 1852 } 1853 inode = d_inode(child); 1854 ino = inode->i_ino; 1855 type = inode->i_mode >> 12; 1856 dput(child); 1857 return dir_emit(ctx, name, len, ino, type); 1858 1859 end_instantiate: 1860 return dir_emit(ctx, name, len, 1, DT_UNKNOWN); 1861 } 1862 1863 /* 1864 * dname_to_vma_addr - maps a dentry name into two unsigned longs 1865 * which represent vma start and end addresses. 1866 */ 1867 static int dname_to_vma_addr(struct dentry *dentry, 1868 unsigned long *start, unsigned long *end) 1869 { 1870 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2) 1871 return -EINVAL; 1872 1873 return 0; 1874 } 1875 1876 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags) 1877 { 1878 unsigned long vm_start, vm_end; 1879 bool exact_vma_exists = false; 1880 struct mm_struct *mm = NULL; 1881 struct task_struct *task; 1882 const struct cred *cred; 1883 struct inode *inode; 1884 int status = 0; 1885 1886 if (flags & LOOKUP_RCU) 1887 return -ECHILD; 1888 1889 inode = d_inode(dentry); 1890 task = get_proc_task(inode); 1891 if (!task) 1892 goto out_notask; 1893 1894 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); 1895 if (IS_ERR_OR_NULL(mm)) 1896 goto out; 1897 1898 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 1899 down_read(&mm->mmap_sem); 1900 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end); 1901 up_read(&mm->mmap_sem); 1902 } 1903 1904 mmput(mm); 1905 1906 if (exact_vma_exists) { 1907 if (task_dumpable(task)) { 1908 rcu_read_lock(); 1909 cred = __task_cred(task); 1910 inode->i_uid = cred->euid; 1911 inode->i_gid = cred->egid; 1912 rcu_read_unlock(); 1913 } else { 1914 inode->i_uid = GLOBAL_ROOT_UID; 1915 inode->i_gid = GLOBAL_ROOT_GID; 1916 } 1917 security_task_to_inode(task, inode); 1918 status = 1; 1919 } 1920 1921 out: 1922 put_task_struct(task); 1923 1924 out_notask: 1925 return status; 1926 } 1927 1928 static const struct dentry_operations tid_map_files_dentry_operations = { 1929 .d_revalidate = map_files_d_revalidate, 1930 .d_delete = pid_delete_dentry, 1931 }; 1932 1933 static int map_files_get_link(struct dentry *dentry, struct path *path) 1934 { 1935 unsigned long vm_start, vm_end; 1936 struct vm_area_struct *vma; 1937 struct task_struct *task; 1938 struct mm_struct *mm; 1939 int rc; 1940 1941 rc = -ENOENT; 1942 task = get_proc_task(d_inode(dentry)); 1943 if (!task) 1944 goto out; 1945 1946 mm = get_task_mm(task); 1947 put_task_struct(task); 1948 if (!mm) 1949 goto out; 1950 1951 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 1952 if (rc) 1953 goto out_mmput; 1954 1955 rc = -ENOENT; 1956 down_read(&mm->mmap_sem); 1957 vma = find_exact_vma(mm, vm_start, vm_end); 1958 if (vma && vma->vm_file) { 1959 *path = vma->vm_file->f_path; 1960 path_get(path); 1961 rc = 0; 1962 } 1963 up_read(&mm->mmap_sem); 1964 1965 out_mmput: 1966 mmput(mm); 1967 out: 1968 return rc; 1969 } 1970 1971 struct map_files_info { 1972 fmode_t mode; 1973 unsigned int len; 1974 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */ 1975 }; 1976 1977 /* 1978 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the 1979 * symlinks may be used to bypass permissions on ancestor directories in the 1980 * path to the file in question. 1981 */ 1982 static const char * 1983 proc_map_files_get_link(struct dentry *dentry, 1984 struct inode *inode, 1985 struct delayed_call *done) 1986 { 1987 if (!capable(CAP_SYS_ADMIN)) 1988 return ERR_PTR(-EPERM); 1989 1990 return proc_pid_get_link(dentry, inode, done); 1991 } 1992 1993 /* 1994 * Identical to proc_pid_link_inode_operations except for get_link() 1995 */ 1996 static const struct inode_operations proc_map_files_link_inode_operations = { 1997 .readlink = proc_pid_readlink, 1998 .get_link = proc_map_files_get_link, 1999 .setattr = proc_setattr, 2000 }; 2001 2002 static int 2003 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry, 2004 struct task_struct *task, const void *ptr) 2005 { 2006 fmode_t mode = (fmode_t)(unsigned long)ptr; 2007 struct proc_inode *ei; 2008 struct inode *inode; 2009 2010 inode = proc_pid_make_inode(dir->i_sb, task); 2011 if (!inode) 2012 return -ENOENT; 2013 2014 ei = PROC_I(inode); 2015 ei->op.proc_get_link = map_files_get_link; 2016 2017 inode->i_op = &proc_map_files_link_inode_operations; 2018 inode->i_size = 64; 2019 inode->i_mode = S_IFLNK; 2020 2021 if (mode & FMODE_READ) 2022 inode->i_mode |= S_IRUSR; 2023 if (mode & FMODE_WRITE) 2024 inode->i_mode |= S_IWUSR; 2025 2026 d_set_d_op(dentry, &tid_map_files_dentry_operations); 2027 d_add(dentry, inode); 2028 2029 return 0; 2030 } 2031 2032 static struct dentry *proc_map_files_lookup(struct inode *dir, 2033 struct dentry *dentry, unsigned int flags) 2034 { 2035 unsigned long vm_start, vm_end; 2036 struct vm_area_struct *vma; 2037 struct task_struct *task; 2038 int result; 2039 struct mm_struct *mm; 2040 2041 result = -ENOENT; 2042 task = get_proc_task(dir); 2043 if (!task) 2044 goto out; 2045 2046 result = -EACCES; 2047 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2048 goto out_put_task; 2049 2050 result = -ENOENT; 2051 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 2052 goto out_put_task; 2053 2054 mm = get_task_mm(task); 2055 if (!mm) 2056 goto out_put_task; 2057 2058 down_read(&mm->mmap_sem); 2059 vma = find_exact_vma(mm, vm_start, vm_end); 2060 if (!vma) 2061 goto out_no_vma; 2062 2063 if (vma->vm_file) 2064 result = proc_map_files_instantiate(dir, dentry, task, 2065 (void *)(unsigned long)vma->vm_file->f_mode); 2066 2067 out_no_vma: 2068 up_read(&mm->mmap_sem); 2069 mmput(mm); 2070 out_put_task: 2071 put_task_struct(task); 2072 out: 2073 return ERR_PTR(result); 2074 } 2075 2076 static const struct inode_operations proc_map_files_inode_operations = { 2077 .lookup = proc_map_files_lookup, 2078 .permission = proc_fd_permission, 2079 .setattr = proc_setattr, 2080 }; 2081 2082 static int 2083 proc_map_files_readdir(struct file *file, struct dir_context *ctx) 2084 { 2085 struct vm_area_struct *vma; 2086 struct task_struct *task; 2087 struct mm_struct *mm; 2088 unsigned long nr_files, pos, i; 2089 struct flex_array *fa = NULL; 2090 struct map_files_info info; 2091 struct map_files_info *p; 2092 int ret; 2093 2094 ret = -ENOENT; 2095 task = get_proc_task(file_inode(file)); 2096 if (!task) 2097 goto out; 2098 2099 ret = -EACCES; 2100 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2101 goto out_put_task; 2102 2103 ret = 0; 2104 if (!dir_emit_dots(file, ctx)) 2105 goto out_put_task; 2106 2107 mm = get_task_mm(task); 2108 if (!mm) 2109 goto out_put_task; 2110 down_read(&mm->mmap_sem); 2111 2112 nr_files = 0; 2113 2114 /* 2115 * We need two passes here: 2116 * 2117 * 1) Collect vmas of mapped files with mmap_sem taken 2118 * 2) Release mmap_sem and instantiate entries 2119 * 2120 * otherwise we get lockdep complained, since filldir() 2121 * routine might require mmap_sem taken in might_fault(). 2122 */ 2123 2124 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 2125 if (vma->vm_file && ++pos > ctx->pos) 2126 nr_files++; 2127 } 2128 2129 if (nr_files) { 2130 fa = flex_array_alloc(sizeof(info), nr_files, 2131 GFP_KERNEL); 2132 if (!fa || flex_array_prealloc(fa, 0, nr_files, 2133 GFP_KERNEL)) { 2134 ret = -ENOMEM; 2135 if (fa) 2136 flex_array_free(fa); 2137 up_read(&mm->mmap_sem); 2138 mmput(mm); 2139 goto out_put_task; 2140 } 2141 for (i = 0, vma = mm->mmap, pos = 2; vma; 2142 vma = vma->vm_next) { 2143 if (!vma->vm_file) 2144 continue; 2145 if (++pos <= ctx->pos) 2146 continue; 2147 2148 info.mode = vma->vm_file->f_mode; 2149 info.len = snprintf(info.name, 2150 sizeof(info.name), "%lx-%lx", 2151 vma->vm_start, vma->vm_end); 2152 if (flex_array_put(fa, i++, &info, GFP_KERNEL)) 2153 BUG(); 2154 } 2155 } 2156 up_read(&mm->mmap_sem); 2157 2158 for (i = 0; i < nr_files; i++) { 2159 p = flex_array_get(fa, i); 2160 if (!proc_fill_cache(file, ctx, 2161 p->name, p->len, 2162 proc_map_files_instantiate, 2163 task, 2164 (void *)(unsigned long)p->mode)) 2165 break; 2166 ctx->pos++; 2167 } 2168 if (fa) 2169 flex_array_free(fa); 2170 mmput(mm); 2171 2172 out_put_task: 2173 put_task_struct(task); 2174 out: 2175 return ret; 2176 } 2177 2178 static const struct file_operations proc_map_files_operations = { 2179 .read = generic_read_dir, 2180 .iterate_shared = proc_map_files_readdir, 2181 .llseek = generic_file_llseek, 2182 }; 2183 2184 #ifdef CONFIG_CHECKPOINT_RESTORE 2185 struct timers_private { 2186 struct pid *pid; 2187 struct task_struct *task; 2188 struct sighand_struct *sighand; 2189 struct pid_namespace *ns; 2190 unsigned long flags; 2191 }; 2192 2193 static void *timers_start(struct seq_file *m, loff_t *pos) 2194 { 2195 struct timers_private *tp = m->private; 2196 2197 tp->task = get_pid_task(tp->pid, PIDTYPE_PID); 2198 if (!tp->task) 2199 return ERR_PTR(-ESRCH); 2200 2201 tp->sighand = lock_task_sighand(tp->task, &tp->flags); 2202 if (!tp->sighand) 2203 return ERR_PTR(-ESRCH); 2204 2205 return seq_list_start(&tp->task->signal->posix_timers, *pos); 2206 } 2207 2208 static void *timers_next(struct seq_file *m, void *v, loff_t *pos) 2209 { 2210 struct timers_private *tp = m->private; 2211 return seq_list_next(v, &tp->task->signal->posix_timers, pos); 2212 } 2213 2214 static void timers_stop(struct seq_file *m, void *v) 2215 { 2216 struct timers_private *tp = m->private; 2217 2218 if (tp->sighand) { 2219 unlock_task_sighand(tp->task, &tp->flags); 2220 tp->sighand = NULL; 2221 } 2222 2223 if (tp->task) { 2224 put_task_struct(tp->task); 2225 tp->task = NULL; 2226 } 2227 } 2228 2229 static int show_timer(struct seq_file *m, void *v) 2230 { 2231 struct k_itimer *timer; 2232 struct timers_private *tp = m->private; 2233 int notify; 2234 static const char * const nstr[] = { 2235 [SIGEV_SIGNAL] = "signal", 2236 [SIGEV_NONE] = "none", 2237 [SIGEV_THREAD] = "thread", 2238 }; 2239 2240 timer = list_entry((struct list_head *)v, struct k_itimer, list); 2241 notify = timer->it_sigev_notify; 2242 2243 seq_printf(m, "ID: %d\n", timer->it_id); 2244 seq_printf(m, "signal: %d/%p\n", 2245 timer->sigq->info.si_signo, 2246 timer->sigq->info.si_value.sival_ptr); 2247 seq_printf(m, "notify: %s/%s.%d\n", 2248 nstr[notify & ~SIGEV_THREAD_ID], 2249 (notify & SIGEV_THREAD_ID) ? "tid" : "pid", 2250 pid_nr_ns(timer->it_pid, tp->ns)); 2251 seq_printf(m, "ClockID: %d\n", timer->it_clock); 2252 2253 return 0; 2254 } 2255 2256 static const struct seq_operations proc_timers_seq_ops = { 2257 .start = timers_start, 2258 .next = timers_next, 2259 .stop = timers_stop, 2260 .show = show_timer, 2261 }; 2262 2263 static int proc_timers_open(struct inode *inode, struct file *file) 2264 { 2265 struct timers_private *tp; 2266 2267 tp = __seq_open_private(file, &proc_timers_seq_ops, 2268 sizeof(struct timers_private)); 2269 if (!tp) 2270 return -ENOMEM; 2271 2272 tp->pid = proc_pid(inode); 2273 tp->ns = inode->i_sb->s_fs_info; 2274 return 0; 2275 } 2276 2277 static const struct file_operations proc_timers_operations = { 2278 .open = proc_timers_open, 2279 .read = seq_read, 2280 .llseek = seq_lseek, 2281 .release = seq_release_private, 2282 }; 2283 #endif 2284 2285 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf, 2286 size_t count, loff_t *offset) 2287 { 2288 struct inode *inode = file_inode(file); 2289 struct task_struct *p; 2290 u64 slack_ns; 2291 int err; 2292 2293 err = kstrtoull_from_user(buf, count, 10, &slack_ns); 2294 if (err < 0) 2295 return err; 2296 2297 p = get_proc_task(inode); 2298 if (!p) 2299 return -ESRCH; 2300 2301 if (p != current) { 2302 if (!capable(CAP_SYS_NICE)) { 2303 count = -EPERM; 2304 goto out; 2305 } 2306 2307 err = security_task_setscheduler(p); 2308 if (err) { 2309 count = err; 2310 goto out; 2311 } 2312 } 2313 2314 task_lock(p); 2315 if (slack_ns == 0) 2316 p->timer_slack_ns = p->default_timer_slack_ns; 2317 else 2318 p->timer_slack_ns = slack_ns; 2319 task_unlock(p); 2320 2321 out: 2322 put_task_struct(p); 2323 2324 return count; 2325 } 2326 2327 static int timerslack_ns_show(struct seq_file *m, void *v) 2328 { 2329 struct inode *inode = m->private; 2330 struct task_struct *p; 2331 int err = 0; 2332 2333 p = get_proc_task(inode); 2334 if (!p) 2335 return -ESRCH; 2336 2337 if (p != current) { 2338 2339 if (!capable(CAP_SYS_NICE)) { 2340 err = -EPERM; 2341 goto out; 2342 } 2343 err = security_task_getscheduler(p); 2344 if (err) 2345 goto out; 2346 } 2347 2348 task_lock(p); 2349 seq_printf(m, "%llu\n", p->timer_slack_ns); 2350 task_unlock(p); 2351 2352 out: 2353 put_task_struct(p); 2354 2355 return err; 2356 } 2357 2358 static int timerslack_ns_open(struct inode *inode, struct file *filp) 2359 { 2360 return single_open(filp, timerslack_ns_show, inode); 2361 } 2362 2363 static const struct file_operations proc_pid_set_timerslack_ns_operations = { 2364 .open = timerslack_ns_open, 2365 .read = seq_read, 2366 .write = timerslack_ns_write, 2367 .llseek = seq_lseek, 2368 .release = single_release, 2369 }; 2370 2371 static int proc_pident_instantiate(struct inode *dir, 2372 struct dentry *dentry, struct task_struct *task, const void *ptr) 2373 { 2374 const struct pid_entry *p = ptr; 2375 struct inode *inode; 2376 struct proc_inode *ei; 2377 2378 inode = proc_pid_make_inode(dir->i_sb, task); 2379 if (!inode) 2380 goto out; 2381 2382 ei = PROC_I(inode); 2383 inode->i_mode = p->mode; 2384 if (S_ISDIR(inode->i_mode)) 2385 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2386 if (p->iop) 2387 inode->i_op = p->iop; 2388 if (p->fop) 2389 inode->i_fop = p->fop; 2390 ei->op = p->op; 2391 d_set_d_op(dentry, &pid_dentry_operations); 2392 d_add(dentry, inode); 2393 /* Close the race of the process dying before we return the dentry */ 2394 if (pid_revalidate(dentry, 0)) 2395 return 0; 2396 out: 2397 return -ENOENT; 2398 } 2399 2400 static struct dentry *proc_pident_lookup(struct inode *dir, 2401 struct dentry *dentry, 2402 const struct pid_entry *ents, 2403 unsigned int nents) 2404 { 2405 int error; 2406 struct task_struct *task = get_proc_task(dir); 2407 const struct pid_entry *p, *last; 2408 2409 error = -ENOENT; 2410 2411 if (!task) 2412 goto out_no_task; 2413 2414 /* 2415 * Yes, it does not scale. And it should not. Don't add 2416 * new entries into /proc/<tgid>/ without very good reasons. 2417 */ 2418 last = &ents[nents]; 2419 for (p = ents; p < last; p++) { 2420 if (p->len != dentry->d_name.len) 2421 continue; 2422 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2423 break; 2424 } 2425 if (p >= last) 2426 goto out; 2427 2428 error = proc_pident_instantiate(dir, dentry, task, p); 2429 out: 2430 put_task_struct(task); 2431 out_no_task: 2432 return ERR_PTR(error); 2433 } 2434 2435 static int proc_pident_readdir(struct file *file, struct dir_context *ctx, 2436 const struct pid_entry *ents, unsigned int nents) 2437 { 2438 struct task_struct *task = get_proc_task(file_inode(file)); 2439 const struct pid_entry *p; 2440 2441 if (!task) 2442 return -ENOENT; 2443 2444 if (!dir_emit_dots(file, ctx)) 2445 goto out; 2446 2447 if (ctx->pos >= nents + 2) 2448 goto out; 2449 2450 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) { 2451 if (!proc_fill_cache(file, ctx, p->name, p->len, 2452 proc_pident_instantiate, task, p)) 2453 break; 2454 ctx->pos++; 2455 } 2456 out: 2457 put_task_struct(task); 2458 return 0; 2459 } 2460 2461 #ifdef CONFIG_SECURITY 2462 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2463 size_t count, loff_t *ppos) 2464 { 2465 struct inode * inode = file_inode(file); 2466 char *p = NULL; 2467 ssize_t length; 2468 struct task_struct *task = get_proc_task(inode); 2469 2470 if (!task) 2471 return -ESRCH; 2472 2473 length = security_getprocattr(task, 2474 (char*)file->f_path.dentry->d_name.name, 2475 &p); 2476 put_task_struct(task); 2477 if (length > 0) 2478 length = simple_read_from_buffer(buf, count, ppos, p, length); 2479 kfree(p); 2480 return length; 2481 } 2482 2483 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2484 size_t count, loff_t *ppos) 2485 { 2486 struct inode * inode = file_inode(file); 2487 void *page; 2488 ssize_t length; 2489 struct task_struct *task = get_proc_task(inode); 2490 2491 length = -ESRCH; 2492 if (!task) 2493 goto out_no_task; 2494 if (count > PAGE_SIZE) 2495 count = PAGE_SIZE; 2496 2497 /* No partial writes. */ 2498 length = -EINVAL; 2499 if (*ppos != 0) 2500 goto out; 2501 2502 page = memdup_user(buf, count); 2503 if (IS_ERR(page)) { 2504 length = PTR_ERR(page); 2505 goto out; 2506 } 2507 2508 /* Guard against adverse ptrace interaction */ 2509 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex); 2510 if (length < 0) 2511 goto out_free; 2512 2513 length = security_setprocattr(task, 2514 (char*)file->f_path.dentry->d_name.name, 2515 page, count); 2516 mutex_unlock(&task->signal->cred_guard_mutex); 2517 out_free: 2518 kfree(page); 2519 out: 2520 put_task_struct(task); 2521 out_no_task: 2522 return length; 2523 } 2524 2525 static const struct file_operations proc_pid_attr_operations = { 2526 .read = proc_pid_attr_read, 2527 .write = proc_pid_attr_write, 2528 .llseek = generic_file_llseek, 2529 }; 2530 2531 static const struct pid_entry attr_dir_stuff[] = { 2532 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2533 REG("prev", S_IRUGO, proc_pid_attr_operations), 2534 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2535 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2536 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2537 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2538 }; 2539 2540 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx) 2541 { 2542 return proc_pident_readdir(file, ctx, 2543 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2544 } 2545 2546 static const struct file_operations proc_attr_dir_operations = { 2547 .read = generic_read_dir, 2548 .iterate_shared = proc_attr_dir_readdir, 2549 .llseek = generic_file_llseek, 2550 }; 2551 2552 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2553 struct dentry *dentry, unsigned int flags) 2554 { 2555 return proc_pident_lookup(dir, dentry, 2556 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2557 } 2558 2559 static const struct inode_operations proc_attr_dir_inode_operations = { 2560 .lookup = proc_attr_dir_lookup, 2561 .getattr = pid_getattr, 2562 .setattr = proc_setattr, 2563 }; 2564 2565 #endif 2566 2567 #ifdef CONFIG_ELF_CORE 2568 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2569 size_t count, loff_t *ppos) 2570 { 2571 struct task_struct *task = get_proc_task(file_inode(file)); 2572 struct mm_struct *mm; 2573 char buffer[PROC_NUMBUF]; 2574 size_t len; 2575 int ret; 2576 2577 if (!task) 2578 return -ESRCH; 2579 2580 ret = 0; 2581 mm = get_task_mm(task); 2582 if (mm) { 2583 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2584 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2585 MMF_DUMP_FILTER_SHIFT)); 2586 mmput(mm); 2587 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2588 } 2589 2590 put_task_struct(task); 2591 2592 return ret; 2593 } 2594 2595 static ssize_t proc_coredump_filter_write(struct file *file, 2596 const char __user *buf, 2597 size_t count, 2598 loff_t *ppos) 2599 { 2600 struct task_struct *task; 2601 struct mm_struct *mm; 2602 unsigned int val; 2603 int ret; 2604 int i; 2605 unsigned long mask; 2606 2607 ret = kstrtouint_from_user(buf, count, 0, &val); 2608 if (ret < 0) 2609 return ret; 2610 2611 ret = -ESRCH; 2612 task = get_proc_task(file_inode(file)); 2613 if (!task) 2614 goto out_no_task; 2615 2616 mm = get_task_mm(task); 2617 if (!mm) 2618 goto out_no_mm; 2619 ret = 0; 2620 2621 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2622 if (val & mask) 2623 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2624 else 2625 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2626 } 2627 2628 mmput(mm); 2629 out_no_mm: 2630 put_task_struct(task); 2631 out_no_task: 2632 if (ret < 0) 2633 return ret; 2634 return count; 2635 } 2636 2637 static const struct file_operations proc_coredump_filter_operations = { 2638 .read = proc_coredump_filter_read, 2639 .write = proc_coredump_filter_write, 2640 .llseek = generic_file_llseek, 2641 }; 2642 #endif 2643 2644 #ifdef CONFIG_TASK_IO_ACCOUNTING 2645 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole) 2646 { 2647 struct task_io_accounting acct = task->ioac; 2648 unsigned long flags; 2649 int result; 2650 2651 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2652 if (result) 2653 return result; 2654 2655 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { 2656 result = -EACCES; 2657 goto out_unlock; 2658 } 2659 2660 if (whole && lock_task_sighand(task, &flags)) { 2661 struct task_struct *t = task; 2662 2663 task_io_accounting_add(&acct, &task->signal->ioac); 2664 while_each_thread(task, t) 2665 task_io_accounting_add(&acct, &t->ioac); 2666 2667 unlock_task_sighand(task, &flags); 2668 } 2669 seq_printf(m, 2670 "rchar: %llu\n" 2671 "wchar: %llu\n" 2672 "syscr: %llu\n" 2673 "syscw: %llu\n" 2674 "read_bytes: %llu\n" 2675 "write_bytes: %llu\n" 2676 "cancelled_write_bytes: %llu\n", 2677 (unsigned long long)acct.rchar, 2678 (unsigned long long)acct.wchar, 2679 (unsigned long long)acct.syscr, 2680 (unsigned long long)acct.syscw, 2681 (unsigned long long)acct.read_bytes, 2682 (unsigned long long)acct.write_bytes, 2683 (unsigned long long)acct.cancelled_write_bytes); 2684 result = 0; 2685 2686 out_unlock: 2687 mutex_unlock(&task->signal->cred_guard_mutex); 2688 return result; 2689 } 2690 2691 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2692 struct pid *pid, struct task_struct *task) 2693 { 2694 return do_io_accounting(task, m, 0); 2695 } 2696 2697 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2698 struct pid *pid, struct task_struct *task) 2699 { 2700 return do_io_accounting(task, m, 1); 2701 } 2702 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2703 2704 #ifdef CONFIG_USER_NS 2705 static int proc_id_map_open(struct inode *inode, struct file *file, 2706 const struct seq_operations *seq_ops) 2707 { 2708 struct user_namespace *ns = NULL; 2709 struct task_struct *task; 2710 struct seq_file *seq; 2711 int ret = -EINVAL; 2712 2713 task = get_proc_task(inode); 2714 if (task) { 2715 rcu_read_lock(); 2716 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2717 rcu_read_unlock(); 2718 put_task_struct(task); 2719 } 2720 if (!ns) 2721 goto err; 2722 2723 ret = seq_open(file, seq_ops); 2724 if (ret) 2725 goto err_put_ns; 2726 2727 seq = file->private_data; 2728 seq->private = ns; 2729 2730 return 0; 2731 err_put_ns: 2732 put_user_ns(ns); 2733 err: 2734 return ret; 2735 } 2736 2737 static int proc_id_map_release(struct inode *inode, struct file *file) 2738 { 2739 struct seq_file *seq = file->private_data; 2740 struct user_namespace *ns = seq->private; 2741 put_user_ns(ns); 2742 return seq_release(inode, file); 2743 } 2744 2745 static int proc_uid_map_open(struct inode *inode, struct file *file) 2746 { 2747 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2748 } 2749 2750 static int proc_gid_map_open(struct inode *inode, struct file *file) 2751 { 2752 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2753 } 2754 2755 static int proc_projid_map_open(struct inode *inode, struct file *file) 2756 { 2757 return proc_id_map_open(inode, file, &proc_projid_seq_operations); 2758 } 2759 2760 static const struct file_operations proc_uid_map_operations = { 2761 .open = proc_uid_map_open, 2762 .write = proc_uid_map_write, 2763 .read = seq_read, 2764 .llseek = seq_lseek, 2765 .release = proc_id_map_release, 2766 }; 2767 2768 static const struct file_operations proc_gid_map_operations = { 2769 .open = proc_gid_map_open, 2770 .write = proc_gid_map_write, 2771 .read = seq_read, 2772 .llseek = seq_lseek, 2773 .release = proc_id_map_release, 2774 }; 2775 2776 static const struct file_operations proc_projid_map_operations = { 2777 .open = proc_projid_map_open, 2778 .write = proc_projid_map_write, 2779 .read = seq_read, 2780 .llseek = seq_lseek, 2781 .release = proc_id_map_release, 2782 }; 2783 2784 static int proc_setgroups_open(struct inode *inode, struct file *file) 2785 { 2786 struct user_namespace *ns = NULL; 2787 struct task_struct *task; 2788 int ret; 2789 2790 ret = -ESRCH; 2791 task = get_proc_task(inode); 2792 if (task) { 2793 rcu_read_lock(); 2794 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2795 rcu_read_unlock(); 2796 put_task_struct(task); 2797 } 2798 if (!ns) 2799 goto err; 2800 2801 if (file->f_mode & FMODE_WRITE) { 2802 ret = -EACCES; 2803 if (!ns_capable(ns, CAP_SYS_ADMIN)) 2804 goto err_put_ns; 2805 } 2806 2807 ret = single_open(file, &proc_setgroups_show, ns); 2808 if (ret) 2809 goto err_put_ns; 2810 2811 return 0; 2812 err_put_ns: 2813 put_user_ns(ns); 2814 err: 2815 return ret; 2816 } 2817 2818 static int proc_setgroups_release(struct inode *inode, struct file *file) 2819 { 2820 struct seq_file *seq = file->private_data; 2821 struct user_namespace *ns = seq->private; 2822 int ret = single_release(inode, file); 2823 put_user_ns(ns); 2824 return ret; 2825 } 2826 2827 static const struct file_operations proc_setgroups_operations = { 2828 .open = proc_setgroups_open, 2829 .write = proc_setgroups_write, 2830 .read = seq_read, 2831 .llseek = seq_lseek, 2832 .release = proc_setgroups_release, 2833 }; 2834 #endif /* CONFIG_USER_NS */ 2835 2836 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2837 struct pid *pid, struct task_struct *task) 2838 { 2839 int err = lock_trace(task); 2840 if (!err) { 2841 seq_printf(m, "%08x\n", task->personality); 2842 unlock_trace(task); 2843 } 2844 return err; 2845 } 2846 2847 /* 2848 * Thread groups 2849 */ 2850 static const struct file_operations proc_task_operations; 2851 static const struct inode_operations proc_task_inode_operations; 2852 2853 static const struct pid_entry tgid_base_stuff[] = { 2854 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2855 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2856 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 2857 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2858 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2859 #ifdef CONFIG_NET 2860 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2861 #endif 2862 REG("environ", S_IRUSR, proc_environ_operations), 2863 REG("auxv", S_IRUSR, proc_auxv_operations), 2864 ONE("status", S_IRUGO, proc_pid_status), 2865 ONE("personality", S_IRUSR, proc_pid_personality), 2866 ONE("limits", S_IRUGO, proc_pid_limits), 2867 #ifdef CONFIG_SCHED_DEBUG 2868 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2869 #endif 2870 #ifdef CONFIG_SCHED_AUTOGROUP 2871 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2872 #endif 2873 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2874 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2875 ONE("syscall", S_IRUSR, proc_pid_syscall), 2876 #endif 2877 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 2878 ONE("stat", S_IRUGO, proc_tgid_stat), 2879 ONE("statm", S_IRUGO, proc_pid_statm), 2880 REG("maps", S_IRUGO, proc_pid_maps_operations), 2881 #ifdef CONFIG_NUMA 2882 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 2883 #endif 2884 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2885 LNK("cwd", proc_cwd_link), 2886 LNK("root", proc_root_link), 2887 LNK("exe", proc_exe_link), 2888 REG("mounts", S_IRUGO, proc_mounts_operations), 2889 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2890 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2891 #ifdef CONFIG_PROC_PAGE_MONITOR 2892 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2893 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 2894 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2895 #endif 2896 #ifdef CONFIG_SECURITY 2897 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2898 #endif 2899 #ifdef CONFIG_KALLSYMS 2900 ONE("wchan", S_IRUGO, proc_pid_wchan), 2901 #endif 2902 #ifdef CONFIG_STACKTRACE 2903 ONE("stack", S_IRUSR, proc_pid_stack), 2904 #endif 2905 #ifdef CONFIG_SCHED_INFO 2906 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 2907 #endif 2908 #ifdef CONFIG_LATENCYTOP 2909 REG("latency", S_IRUGO, proc_lstats_operations), 2910 #endif 2911 #ifdef CONFIG_PROC_PID_CPUSET 2912 ONE("cpuset", S_IRUGO, proc_cpuset_show), 2913 #endif 2914 #ifdef CONFIG_CGROUPS 2915 ONE("cgroup", S_IRUGO, proc_cgroup_show), 2916 #endif 2917 ONE("oom_score", S_IRUGO, proc_oom_score), 2918 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 2919 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2920 #ifdef CONFIG_AUDITSYSCALL 2921 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2922 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2923 #endif 2924 #ifdef CONFIG_FAULT_INJECTION 2925 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2926 #endif 2927 #ifdef CONFIG_ELF_CORE 2928 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2929 #endif 2930 #ifdef CONFIG_TASK_IO_ACCOUNTING 2931 ONE("io", S_IRUSR, proc_tgid_io_accounting), 2932 #endif 2933 #ifdef CONFIG_HARDWALL 2934 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 2935 #endif 2936 #ifdef CONFIG_USER_NS 2937 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 2938 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 2939 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 2940 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 2941 #endif 2942 #ifdef CONFIG_CHECKPOINT_RESTORE 2943 REG("timers", S_IRUGO, proc_timers_operations), 2944 #endif 2945 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations), 2946 }; 2947 2948 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) 2949 { 2950 return proc_pident_readdir(file, ctx, 2951 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2952 } 2953 2954 static const struct file_operations proc_tgid_base_operations = { 2955 .read = generic_read_dir, 2956 .iterate_shared = proc_tgid_base_readdir, 2957 .llseek = generic_file_llseek, 2958 }; 2959 2960 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 2961 { 2962 return proc_pident_lookup(dir, dentry, 2963 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2964 } 2965 2966 static const struct inode_operations proc_tgid_base_inode_operations = { 2967 .lookup = proc_tgid_base_lookup, 2968 .getattr = pid_getattr, 2969 .setattr = proc_setattr, 2970 .permission = proc_pid_permission, 2971 }; 2972 2973 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2974 { 2975 struct dentry *dentry, *leader, *dir; 2976 char buf[PROC_NUMBUF]; 2977 struct qstr name; 2978 2979 name.name = buf; 2980 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2981 /* no ->d_hash() rejects on procfs */ 2982 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2983 if (dentry) { 2984 d_invalidate(dentry); 2985 dput(dentry); 2986 } 2987 2988 if (pid == tgid) 2989 return; 2990 2991 name.name = buf; 2992 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2993 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2994 if (!leader) 2995 goto out; 2996 2997 name.name = "task"; 2998 name.len = strlen(name.name); 2999 dir = d_hash_and_lookup(leader, &name); 3000 if (!dir) 3001 goto out_put_leader; 3002 3003 name.name = buf; 3004 name.len = snprintf(buf, sizeof(buf), "%d", pid); 3005 dentry = d_hash_and_lookup(dir, &name); 3006 if (dentry) { 3007 d_invalidate(dentry); 3008 dput(dentry); 3009 } 3010 3011 dput(dir); 3012 out_put_leader: 3013 dput(leader); 3014 out: 3015 return; 3016 } 3017 3018 /** 3019 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 3020 * @task: task that should be flushed. 3021 * 3022 * When flushing dentries from proc, one needs to flush them from global 3023 * proc (proc_mnt) and from all the namespaces' procs this task was seen 3024 * in. This call is supposed to do all of this job. 3025 * 3026 * Looks in the dcache for 3027 * /proc/@pid 3028 * /proc/@tgid/task/@pid 3029 * if either directory is present flushes it and all of it'ts children 3030 * from the dcache. 3031 * 3032 * It is safe and reasonable to cache /proc entries for a task until 3033 * that task exits. After that they just clog up the dcache with 3034 * useless entries, possibly causing useful dcache entries to be 3035 * flushed instead. This routine is proved to flush those useless 3036 * dcache entries at process exit time. 3037 * 3038 * NOTE: This routine is just an optimization so it does not guarantee 3039 * that no dcache entries will exist at process exit time it 3040 * just makes it very unlikely that any will persist. 3041 */ 3042 3043 void proc_flush_task(struct task_struct *task) 3044 { 3045 int i; 3046 struct pid *pid, *tgid; 3047 struct upid *upid; 3048 3049 pid = task_pid(task); 3050 tgid = task_tgid(task); 3051 3052 for (i = 0; i <= pid->level; i++) { 3053 upid = &pid->numbers[i]; 3054 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3055 tgid->numbers[i].nr); 3056 } 3057 } 3058 3059 static int proc_pid_instantiate(struct inode *dir, 3060 struct dentry * dentry, 3061 struct task_struct *task, const void *ptr) 3062 { 3063 struct inode *inode; 3064 3065 inode = proc_pid_make_inode(dir->i_sb, task); 3066 if (!inode) 3067 goto out; 3068 3069 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3070 inode->i_op = &proc_tgid_base_inode_operations; 3071 inode->i_fop = &proc_tgid_base_operations; 3072 inode->i_flags|=S_IMMUTABLE; 3073 3074 set_nlink(inode, nlink_tgid); 3075 3076 d_set_d_op(dentry, &pid_dentry_operations); 3077 3078 d_add(dentry, inode); 3079 /* Close the race of the process dying before we return the dentry */ 3080 if (pid_revalidate(dentry, 0)) 3081 return 0; 3082 out: 3083 return -ENOENT; 3084 } 3085 3086 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3087 { 3088 int result = -ENOENT; 3089 struct task_struct *task; 3090 unsigned tgid; 3091 struct pid_namespace *ns; 3092 3093 tgid = name_to_int(&dentry->d_name); 3094 if (tgid == ~0U) 3095 goto out; 3096 3097 ns = dentry->d_sb->s_fs_info; 3098 rcu_read_lock(); 3099 task = find_task_by_pid_ns(tgid, ns); 3100 if (task) 3101 get_task_struct(task); 3102 rcu_read_unlock(); 3103 if (!task) 3104 goto out; 3105 3106 result = proc_pid_instantiate(dir, dentry, task, NULL); 3107 put_task_struct(task); 3108 out: 3109 return ERR_PTR(result); 3110 } 3111 3112 /* 3113 * Find the first task with tgid >= tgid 3114 * 3115 */ 3116 struct tgid_iter { 3117 unsigned int tgid; 3118 struct task_struct *task; 3119 }; 3120 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3121 { 3122 struct pid *pid; 3123 3124 if (iter.task) 3125 put_task_struct(iter.task); 3126 rcu_read_lock(); 3127 retry: 3128 iter.task = NULL; 3129 pid = find_ge_pid(iter.tgid, ns); 3130 if (pid) { 3131 iter.tgid = pid_nr_ns(pid, ns); 3132 iter.task = pid_task(pid, PIDTYPE_PID); 3133 /* What we to know is if the pid we have find is the 3134 * pid of a thread_group_leader. Testing for task 3135 * being a thread_group_leader is the obvious thing 3136 * todo but there is a window when it fails, due to 3137 * the pid transfer logic in de_thread. 3138 * 3139 * So we perform the straight forward test of seeing 3140 * if the pid we have found is the pid of a thread 3141 * group leader, and don't worry if the task we have 3142 * found doesn't happen to be a thread group leader. 3143 * As we don't care in the case of readdir. 3144 */ 3145 if (!iter.task || !has_group_leader_pid(iter.task)) { 3146 iter.tgid += 1; 3147 goto retry; 3148 } 3149 get_task_struct(iter.task); 3150 } 3151 rcu_read_unlock(); 3152 return iter; 3153 } 3154 3155 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2) 3156 3157 /* for the /proc/ directory itself, after non-process stuff has been done */ 3158 int proc_pid_readdir(struct file *file, struct dir_context *ctx) 3159 { 3160 struct tgid_iter iter; 3161 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info; 3162 loff_t pos = ctx->pos; 3163 3164 if (pos >= PID_MAX_LIMIT + TGID_OFFSET) 3165 return 0; 3166 3167 if (pos == TGID_OFFSET - 2) { 3168 struct inode *inode = d_inode(ns->proc_self); 3169 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) 3170 return 0; 3171 ctx->pos = pos = pos + 1; 3172 } 3173 if (pos == TGID_OFFSET - 1) { 3174 struct inode *inode = d_inode(ns->proc_thread_self); 3175 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) 3176 return 0; 3177 ctx->pos = pos = pos + 1; 3178 } 3179 iter.tgid = pos - TGID_OFFSET; 3180 iter.task = NULL; 3181 for (iter = next_tgid(ns, iter); 3182 iter.task; 3183 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3184 char name[PROC_NUMBUF]; 3185 int len; 3186 if (!has_pid_permissions(ns, iter.task, 2)) 3187 continue; 3188 3189 len = snprintf(name, sizeof(name), "%d", iter.tgid); 3190 ctx->pos = iter.tgid + TGID_OFFSET; 3191 if (!proc_fill_cache(file, ctx, name, len, 3192 proc_pid_instantiate, iter.task, NULL)) { 3193 put_task_struct(iter.task); 3194 return 0; 3195 } 3196 } 3197 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET; 3198 return 0; 3199 } 3200 3201 /* 3202 * proc_tid_comm_permission is a special permission function exclusively 3203 * used for the node /proc/<pid>/task/<tid>/comm. 3204 * It bypasses generic permission checks in the case where a task of the same 3205 * task group attempts to access the node. 3206 * The rationale behind this is that glibc and bionic access this node for 3207 * cross thread naming (pthread_set/getname_np(!self)). However, if 3208 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0, 3209 * which locks out the cross thread naming implementation. 3210 * This function makes sure that the node is always accessible for members of 3211 * same thread group. 3212 */ 3213 static int proc_tid_comm_permission(struct inode *inode, int mask) 3214 { 3215 bool is_same_tgroup; 3216 struct task_struct *task; 3217 3218 task = get_proc_task(inode); 3219 if (!task) 3220 return -ESRCH; 3221 is_same_tgroup = same_thread_group(current, task); 3222 put_task_struct(task); 3223 3224 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) { 3225 /* This file (/proc/<pid>/task/<tid>/comm) can always be 3226 * read or written by the members of the corresponding 3227 * thread group. 3228 */ 3229 return 0; 3230 } 3231 3232 return generic_permission(inode, mask); 3233 } 3234 3235 static const struct inode_operations proc_tid_comm_inode_operations = { 3236 .permission = proc_tid_comm_permission, 3237 }; 3238 3239 /* 3240 * Tasks 3241 */ 3242 static const struct pid_entry tid_base_stuff[] = { 3243 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3244 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3245 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3246 #ifdef CONFIG_NET 3247 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3248 #endif 3249 REG("environ", S_IRUSR, proc_environ_operations), 3250 REG("auxv", S_IRUSR, proc_auxv_operations), 3251 ONE("status", S_IRUGO, proc_pid_status), 3252 ONE("personality", S_IRUSR, proc_pid_personality), 3253 ONE("limits", S_IRUGO, proc_pid_limits), 3254 #ifdef CONFIG_SCHED_DEBUG 3255 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3256 #endif 3257 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR, 3258 &proc_tid_comm_inode_operations, 3259 &proc_pid_set_comm_operations, {}), 3260 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3261 ONE("syscall", S_IRUSR, proc_pid_syscall), 3262 #endif 3263 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 3264 ONE("stat", S_IRUGO, proc_tid_stat), 3265 ONE("statm", S_IRUGO, proc_pid_statm), 3266 REG("maps", S_IRUGO, proc_tid_maps_operations), 3267 #ifdef CONFIG_PROC_CHILDREN 3268 REG("children", S_IRUGO, proc_tid_children_operations), 3269 #endif 3270 #ifdef CONFIG_NUMA 3271 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations), 3272 #endif 3273 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3274 LNK("cwd", proc_cwd_link), 3275 LNK("root", proc_root_link), 3276 LNK("exe", proc_exe_link), 3277 REG("mounts", S_IRUGO, proc_mounts_operations), 3278 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3279 #ifdef CONFIG_PROC_PAGE_MONITOR 3280 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3281 REG("smaps", S_IRUGO, proc_tid_smaps_operations), 3282 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3283 #endif 3284 #ifdef CONFIG_SECURITY 3285 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3286 #endif 3287 #ifdef CONFIG_KALLSYMS 3288 ONE("wchan", S_IRUGO, proc_pid_wchan), 3289 #endif 3290 #ifdef CONFIG_STACKTRACE 3291 ONE("stack", S_IRUSR, proc_pid_stack), 3292 #endif 3293 #ifdef CONFIG_SCHED_INFO 3294 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 3295 #endif 3296 #ifdef CONFIG_LATENCYTOP 3297 REG("latency", S_IRUGO, proc_lstats_operations), 3298 #endif 3299 #ifdef CONFIG_PROC_PID_CPUSET 3300 ONE("cpuset", S_IRUGO, proc_cpuset_show), 3301 #endif 3302 #ifdef CONFIG_CGROUPS 3303 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3304 #endif 3305 ONE("oom_score", S_IRUGO, proc_oom_score), 3306 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3307 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3308 #ifdef CONFIG_AUDITSYSCALL 3309 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3310 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3311 #endif 3312 #ifdef CONFIG_FAULT_INJECTION 3313 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3314 #endif 3315 #ifdef CONFIG_TASK_IO_ACCOUNTING 3316 ONE("io", S_IRUSR, proc_tid_io_accounting), 3317 #endif 3318 #ifdef CONFIG_HARDWALL 3319 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 3320 #endif 3321 #ifdef CONFIG_USER_NS 3322 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3323 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3324 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3325 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3326 #endif 3327 }; 3328 3329 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx) 3330 { 3331 return proc_pident_readdir(file, ctx, 3332 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3333 } 3334 3335 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3336 { 3337 return proc_pident_lookup(dir, dentry, 3338 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3339 } 3340 3341 static const struct file_operations proc_tid_base_operations = { 3342 .read = generic_read_dir, 3343 .iterate_shared = proc_tid_base_readdir, 3344 .llseek = generic_file_llseek, 3345 }; 3346 3347 static const struct inode_operations proc_tid_base_inode_operations = { 3348 .lookup = proc_tid_base_lookup, 3349 .getattr = pid_getattr, 3350 .setattr = proc_setattr, 3351 }; 3352 3353 static int proc_task_instantiate(struct inode *dir, 3354 struct dentry *dentry, struct task_struct *task, const void *ptr) 3355 { 3356 struct inode *inode; 3357 inode = proc_pid_make_inode(dir->i_sb, task); 3358 3359 if (!inode) 3360 goto out; 3361 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3362 inode->i_op = &proc_tid_base_inode_operations; 3363 inode->i_fop = &proc_tid_base_operations; 3364 inode->i_flags|=S_IMMUTABLE; 3365 3366 set_nlink(inode, nlink_tid); 3367 3368 d_set_d_op(dentry, &pid_dentry_operations); 3369 3370 d_add(dentry, inode); 3371 /* Close the race of the process dying before we return the dentry */ 3372 if (pid_revalidate(dentry, 0)) 3373 return 0; 3374 out: 3375 return -ENOENT; 3376 } 3377 3378 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3379 { 3380 int result = -ENOENT; 3381 struct task_struct *task; 3382 struct task_struct *leader = get_proc_task(dir); 3383 unsigned tid; 3384 struct pid_namespace *ns; 3385 3386 if (!leader) 3387 goto out_no_task; 3388 3389 tid = name_to_int(&dentry->d_name); 3390 if (tid == ~0U) 3391 goto out; 3392 3393 ns = dentry->d_sb->s_fs_info; 3394 rcu_read_lock(); 3395 task = find_task_by_pid_ns(tid, ns); 3396 if (task) 3397 get_task_struct(task); 3398 rcu_read_unlock(); 3399 if (!task) 3400 goto out; 3401 if (!same_thread_group(leader, task)) 3402 goto out_drop_task; 3403 3404 result = proc_task_instantiate(dir, dentry, task, NULL); 3405 out_drop_task: 3406 put_task_struct(task); 3407 out: 3408 put_task_struct(leader); 3409 out_no_task: 3410 return ERR_PTR(result); 3411 } 3412 3413 /* 3414 * Find the first tid of a thread group to return to user space. 3415 * 3416 * Usually this is just the thread group leader, but if the users 3417 * buffer was too small or there was a seek into the middle of the 3418 * directory we have more work todo. 3419 * 3420 * In the case of a short read we start with find_task_by_pid. 3421 * 3422 * In the case of a seek we start with the leader and walk nr 3423 * threads past it. 3424 */ 3425 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos, 3426 struct pid_namespace *ns) 3427 { 3428 struct task_struct *pos, *task; 3429 unsigned long nr = f_pos; 3430 3431 if (nr != f_pos) /* 32bit overflow? */ 3432 return NULL; 3433 3434 rcu_read_lock(); 3435 task = pid_task(pid, PIDTYPE_PID); 3436 if (!task) 3437 goto fail; 3438 3439 /* Attempt to start with the tid of a thread */ 3440 if (tid && nr) { 3441 pos = find_task_by_pid_ns(tid, ns); 3442 if (pos && same_thread_group(pos, task)) 3443 goto found; 3444 } 3445 3446 /* If nr exceeds the number of threads there is nothing todo */ 3447 if (nr >= get_nr_threads(task)) 3448 goto fail; 3449 3450 /* If we haven't found our starting place yet start 3451 * with the leader and walk nr threads forward. 3452 */ 3453 pos = task = task->group_leader; 3454 do { 3455 if (!nr--) 3456 goto found; 3457 } while_each_thread(task, pos); 3458 fail: 3459 pos = NULL; 3460 goto out; 3461 found: 3462 get_task_struct(pos); 3463 out: 3464 rcu_read_unlock(); 3465 return pos; 3466 } 3467 3468 /* 3469 * Find the next thread in the thread list. 3470 * Return NULL if there is an error or no next thread. 3471 * 3472 * The reference to the input task_struct is released. 3473 */ 3474 static struct task_struct *next_tid(struct task_struct *start) 3475 { 3476 struct task_struct *pos = NULL; 3477 rcu_read_lock(); 3478 if (pid_alive(start)) { 3479 pos = next_thread(start); 3480 if (thread_group_leader(pos)) 3481 pos = NULL; 3482 else 3483 get_task_struct(pos); 3484 } 3485 rcu_read_unlock(); 3486 put_task_struct(start); 3487 return pos; 3488 } 3489 3490 /* for the /proc/TGID/task/ directories */ 3491 static int proc_task_readdir(struct file *file, struct dir_context *ctx) 3492 { 3493 struct inode *inode = file_inode(file); 3494 struct task_struct *task; 3495 struct pid_namespace *ns; 3496 int tid; 3497 3498 if (proc_inode_is_dead(inode)) 3499 return -ENOENT; 3500 3501 if (!dir_emit_dots(file, ctx)) 3502 return 0; 3503 3504 /* f_version caches the tgid value that the last readdir call couldn't 3505 * return. lseek aka telldir automagically resets f_version to 0. 3506 */ 3507 ns = inode->i_sb->s_fs_info; 3508 tid = (int)file->f_version; 3509 file->f_version = 0; 3510 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); 3511 task; 3512 task = next_tid(task), ctx->pos++) { 3513 char name[PROC_NUMBUF]; 3514 int len; 3515 tid = task_pid_nr_ns(task, ns); 3516 len = snprintf(name, sizeof(name), "%d", tid); 3517 if (!proc_fill_cache(file, ctx, name, len, 3518 proc_task_instantiate, task, NULL)) { 3519 /* returning this tgid failed, save it as the first 3520 * pid for the next readir call */ 3521 file->f_version = (u64)tid; 3522 put_task_struct(task); 3523 break; 3524 } 3525 } 3526 3527 return 0; 3528 } 3529 3530 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3531 { 3532 struct inode *inode = d_inode(dentry); 3533 struct task_struct *p = get_proc_task(inode); 3534 generic_fillattr(inode, stat); 3535 3536 if (p) { 3537 stat->nlink += get_nr_threads(p); 3538 put_task_struct(p); 3539 } 3540 3541 return 0; 3542 } 3543 3544 static const struct inode_operations proc_task_inode_operations = { 3545 .lookup = proc_task_lookup, 3546 .getattr = proc_task_getattr, 3547 .setattr = proc_setattr, 3548 .permission = proc_pid_permission, 3549 }; 3550 3551 static const struct file_operations proc_task_operations = { 3552 .read = generic_read_dir, 3553 .iterate_shared = proc_task_readdir, 3554 .llseek = generic_file_llseek, 3555 }; 3556 3557 void __init set_proc_pid_nlink(void) 3558 { 3559 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3560 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3561 } 3562