1 /* 2 * linux/fs/proc/base.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 * 6 * proc base directory handling functions 7 * 8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part. 9 * Instead of using magical inumbers to determine the kind of object 10 * we allocate and fill in-core inodes upon lookup. They don't even 11 * go into icache. We cache the reference to task_struct upon lookup too. 12 * Eventually it should become a filesystem in its own. We don't use the 13 * rest of procfs anymore. 14 * 15 * 16 * Changelog: 17 * 17-Jan-2005 18 * Allan Bezerra 19 * Bruna Moreira <bruna.moreira@indt.org.br> 20 * Edjard Mota <edjard.mota@indt.org.br> 21 * Ilias Biris <ilias.biris@indt.org.br> 22 * Mauricio Lin <mauricio.lin@indt.org.br> 23 * 24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 25 * 26 * A new process specific entry (smaps) included in /proc. It shows the 27 * size of rss for each memory area. The maps entry lacks information 28 * about physical memory size (rss) for each mapped file, i.e., 29 * rss information for executables and library files. 30 * This additional information is useful for any tools that need to know 31 * about physical memory consumption for a process specific library. 32 * 33 * Changelog: 34 * 21-Feb-2005 35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 36 * Pud inclusion in the page table walking. 37 * 38 * ChangeLog: 39 * 10-Mar-2005 40 * 10LE Instituto Nokia de Tecnologia - INdT: 41 * A better way to walks through the page table as suggested by Hugh Dickins. 42 * 43 * Simo Piiroinen <simo.piiroinen@nokia.com>: 44 * Smaps information related to shared, private, clean and dirty pages. 45 * 46 * Paul Mundt <paul.mundt@nokia.com>: 47 * Overall revision about smaps. 48 */ 49 50 #include <linux/uaccess.h> 51 52 #include <linux/errno.h> 53 #include <linux/time.h> 54 #include <linux/proc_fs.h> 55 #include <linux/stat.h> 56 #include <linux/task_io_accounting_ops.h> 57 #include <linux/init.h> 58 #include <linux/capability.h> 59 #include <linux/file.h> 60 #include <linux/fdtable.h> 61 #include <linux/string.h> 62 #include <linux/seq_file.h> 63 #include <linux/namei.h> 64 #include <linux/mnt_namespace.h> 65 #include <linux/mm.h> 66 #include <linux/swap.h> 67 #include <linux/rcupdate.h> 68 #include <linux/kallsyms.h> 69 #include <linux/stacktrace.h> 70 #include <linux/resource.h> 71 #include <linux/module.h> 72 #include <linux/mount.h> 73 #include <linux/security.h> 74 #include <linux/ptrace.h> 75 #include <linux/tracehook.h> 76 #include <linux/printk.h> 77 #include <linux/cgroup.h> 78 #include <linux/cpuset.h> 79 #include <linux/audit.h> 80 #include <linux/poll.h> 81 #include <linux/nsproxy.h> 82 #include <linux/oom.h> 83 #include <linux/elf.h> 84 #include <linux/pid_namespace.h> 85 #include <linux/user_namespace.h> 86 #include <linux/fs_struct.h> 87 #include <linux/slab.h> 88 #include <linux/sched/autogroup.h> 89 #include <linux/sched/mm.h> 90 #include <linux/sched/coredump.h> 91 #include <linux/sched/debug.h> 92 #include <linux/sched/stat.h> 93 #include <linux/flex_array.h> 94 #include <linux/posix-timers.h> 95 #ifdef CONFIG_HARDWALL 96 #include <asm/hardwall.h> 97 #endif 98 #include <trace/events/oom.h> 99 #include "internal.h" 100 #include "fd.h" 101 102 /* NOTE: 103 * Implementing inode permission operations in /proc is almost 104 * certainly an error. Permission checks need to happen during 105 * each system call not at open time. The reason is that most of 106 * what we wish to check for permissions in /proc varies at runtime. 107 * 108 * The classic example of a problem is opening file descriptors 109 * in /proc for a task before it execs a suid executable. 110 */ 111 112 static u8 nlink_tid; 113 static u8 nlink_tgid; 114 115 struct pid_entry { 116 const char *name; 117 unsigned int len; 118 umode_t mode; 119 const struct inode_operations *iop; 120 const struct file_operations *fop; 121 union proc_op op; 122 }; 123 124 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 125 .name = (NAME), \ 126 .len = sizeof(NAME) - 1, \ 127 .mode = MODE, \ 128 .iop = IOP, \ 129 .fop = FOP, \ 130 .op = OP, \ 131 } 132 133 #define DIR(NAME, MODE, iops, fops) \ 134 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} ) 135 #define LNK(NAME, get_link) \ 136 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 137 &proc_pid_link_inode_operations, NULL, \ 138 { .proc_get_link = get_link } ) 139 #define REG(NAME, MODE, fops) \ 140 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {}) 141 #define ONE(NAME, MODE, show) \ 142 NOD(NAME, (S_IFREG|(MODE)), \ 143 NULL, &proc_single_file_operations, \ 144 { .proc_show = show } ) 145 146 /* 147 * Count the number of hardlinks for the pid_entry table, excluding the . 148 * and .. links. 149 */ 150 static unsigned int __init pid_entry_nlink(const struct pid_entry *entries, 151 unsigned int n) 152 { 153 unsigned int i; 154 unsigned int count; 155 156 count = 2; 157 for (i = 0; i < n; ++i) { 158 if (S_ISDIR(entries[i].mode)) 159 ++count; 160 } 161 162 return count; 163 } 164 165 static int get_task_root(struct task_struct *task, struct path *root) 166 { 167 int result = -ENOENT; 168 169 task_lock(task); 170 if (task->fs) { 171 get_fs_root(task->fs, root); 172 result = 0; 173 } 174 task_unlock(task); 175 return result; 176 } 177 178 static int proc_cwd_link(struct dentry *dentry, struct path *path) 179 { 180 struct task_struct *task = get_proc_task(d_inode(dentry)); 181 int result = -ENOENT; 182 183 if (task) { 184 task_lock(task); 185 if (task->fs) { 186 get_fs_pwd(task->fs, path); 187 result = 0; 188 } 189 task_unlock(task); 190 put_task_struct(task); 191 } 192 return result; 193 } 194 195 static int proc_root_link(struct dentry *dentry, struct path *path) 196 { 197 struct task_struct *task = get_proc_task(d_inode(dentry)); 198 int result = -ENOENT; 199 200 if (task) { 201 result = get_task_root(task, path); 202 put_task_struct(task); 203 } 204 return result; 205 } 206 207 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, 208 size_t _count, loff_t *pos) 209 { 210 struct task_struct *tsk; 211 struct mm_struct *mm; 212 char *page; 213 unsigned long count = _count; 214 unsigned long arg_start, arg_end, env_start, env_end; 215 unsigned long len1, len2, len; 216 unsigned long p; 217 char c; 218 ssize_t rv; 219 220 BUG_ON(*pos < 0); 221 222 tsk = get_proc_task(file_inode(file)); 223 if (!tsk) 224 return -ESRCH; 225 mm = get_task_mm(tsk); 226 put_task_struct(tsk); 227 if (!mm) 228 return 0; 229 /* Check if process spawned far enough to have cmdline. */ 230 if (!mm->env_end) { 231 rv = 0; 232 goto out_mmput; 233 } 234 235 page = (char *)__get_free_page(GFP_TEMPORARY); 236 if (!page) { 237 rv = -ENOMEM; 238 goto out_mmput; 239 } 240 241 down_read(&mm->mmap_sem); 242 arg_start = mm->arg_start; 243 arg_end = mm->arg_end; 244 env_start = mm->env_start; 245 env_end = mm->env_end; 246 up_read(&mm->mmap_sem); 247 248 BUG_ON(arg_start > arg_end); 249 BUG_ON(env_start > env_end); 250 251 len1 = arg_end - arg_start; 252 len2 = env_end - env_start; 253 254 /* Empty ARGV. */ 255 if (len1 == 0) { 256 rv = 0; 257 goto out_free_page; 258 } 259 /* 260 * Inherently racy -- command line shares address space 261 * with code and data. 262 */ 263 rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0); 264 if (rv <= 0) 265 goto out_free_page; 266 267 rv = 0; 268 269 if (c == '\0') { 270 /* Command line (set of strings) occupies whole ARGV. */ 271 if (len1 <= *pos) 272 goto out_free_page; 273 274 p = arg_start + *pos; 275 len = len1 - *pos; 276 while (count > 0 && len > 0) { 277 unsigned int _count; 278 int nr_read; 279 280 _count = min3(count, len, PAGE_SIZE); 281 nr_read = access_remote_vm(mm, p, page, _count, 0); 282 if (nr_read < 0) 283 rv = nr_read; 284 if (nr_read <= 0) 285 goto out_free_page; 286 287 if (copy_to_user(buf, page, nr_read)) { 288 rv = -EFAULT; 289 goto out_free_page; 290 } 291 292 p += nr_read; 293 len -= nr_read; 294 buf += nr_read; 295 count -= nr_read; 296 rv += nr_read; 297 } 298 } else { 299 /* 300 * Command line (1 string) occupies ARGV and 301 * extends into ENVP. 302 */ 303 struct { 304 unsigned long p; 305 unsigned long len; 306 } cmdline[2] = { 307 { .p = arg_start, .len = len1 }, 308 { .p = env_start, .len = len2 }, 309 }; 310 loff_t pos1 = *pos; 311 unsigned int i; 312 313 i = 0; 314 while (i < 2 && pos1 >= cmdline[i].len) { 315 pos1 -= cmdline[i].len; 316 i++; 317 } 318 while (i < 2) { 319 p = cmdline[i].p + pos1; 320 len = cmdline[i].len - pos1; 321 while (count > 0 && len > 0) { 322 unsigned int _count, l; 323 int nr_read; 324 bool final; 325 326 _count = min3(count, len, PAGE_SIZE); 327 nr_read = access_remote_vm(mm, p, page, _count, 0); 328 if (nr_read < 0) 329 rv = nr_read; 330 if (nr_read <= 0) 331 goto out_free_page; 332 333 /* 334 * Command line can be shorter than whole ARGV 335 * even if last "marker" byte says it is not. 336 */ 337 final = false; 338 l = strnlen(page, nr_read); 339 if (l < nr_read) { 340 nr_read = l; 341 final = true; 342 } 343 344 if (copy_to_user(buf, page, nr_read)) { 345 rv = -EFAULT; 346 goto out_free_page; 347 } 348 349 p += nr_read; 350 len -= nr_read; 351 buf += nr_read; 352 count -= nr_read; 353 rv += nr_read; 354 355 if (final) 356 goto out_free_page; 357 } 358 359 /* Only first chunk can be read partially. */ 360 pos1 = 0; 361 i++; 362 } 363 } 364 365 out_free_page: 366 free_page((unsigned long)page); 367 out_mmput: 368 mmput(mm); 369 if (rv > 0) 370 *pos += rv; 371 return rv; 372 } 373 374 static const struct file_operations proc_pid_cmdline_ops = { 375 .read = proc_pid_cmdline_read, 376 .llseek = generic_file_llseek, 377 }; 378 379 #ifdef CONFIG_KALLSYMS 380 /* 381 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 382 * Returns the resolved symbol. If that fails, simply return the address. 383 */ 384 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns, 385 struct pid *pid, struct task_struct *task) 386 { 387 unsigned long wchan; 388 char symname[KSYM_NAME_LEN]; 389 390 wchan = get_wchan(task); 391 392 if (wchan && ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS) 393 && !lookup_symbol_name(wchan, symname)) 394 seq_printf(m, "%s", symname); 395 else 396 seq_putc(m, '0'); 397 398 return 0; 399 } 400 #endif /* CONFIG_KALLSYMS */ 401 402 static int lock_trace(struct task_struct *task) 403 { 404 int err = mutex_lock_killable(&task->signal->cred_guard_mutex); 405 if (err) 406 return err; 407 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) { 408 mutex_unlock(&task->signal->cred_guard_mutex); 409 return -EPERM; 410 } 411 return 0; 412 } 413 414 static void unlock_trace(struct task_struct *task) 415 { 416 mutex_unlock(&task->signal->cred_guard_mutex); 417 } 418 419 #ifdef CONFIG_STACKTRACE 420 421 #define MAX_STACK_TRACE_DEPTH 64 422 423 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, 424 struct pid *pid, struct task_struct *task) 425 { 426 struct stack_trace trace; 427 unsigned long *entries; 428 int err; 429 int i; 430 431 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL); 432 if (!entries) 433 return -ENOMEM; 434 435 trace.nr_entries = 0; 436 trace.max_entries = MAX_STACK_TRACE_DEPTH; 437 trace.entries = entries; 438 trace.skip = 0; 439 440 err = lock_trace(task); 441 if (!err) { 442 save_stack_trace_tsk(task, &trace); 443 444 for (i = 0; i < trace.nr_entries; i++) { 445 seq_printf(m, "[<%pK>] %pB\n", 446 (void *)entries[i], (void *)entries[i]); 447 } 448 unlock_trace(task); 449 } 450 kfree(entries); 451 452 return err; 453 } 454 #endif 455 456 #ifdef CONFIG_SCHED_INFO 457 /* 458 * Provides /proc/PID/schedstat 459 */ 460 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, 461 struct pid *pid, struct task_struct *task) 462 { 463 if (unlikely(!sched_info_on())) 464 seq_printf(m, "0 0 0\n"); 465 else 466 seq_printf(m, "%llu %llu %lu\n", 467 (unsigned long long)task->se.sum_exec_runtime, 468 (unsigned long long)task->sched_info.run_delay, 469 task->sched_info.pcount); 470 471 return 0; 472 } 473 #endif 474 475 #ifdef CONFIG_LATENCYTOP 476 static int lstats_show_proc(struct seq_file *m, void *v) 477 { 478 int i; 479 struct inode *inode = m->private; 480 struct task_struct *task = get_proc_task(inode); 481 482 if (!task) 483 return -ESRCH; 484 seq_puts(m, "Latency Top version : v0.1\n"); 485 for (i = 0; i < 32; i++) { 486 struct latency_record *lr = &task->latency_record[i]; 487 if (lr->backtrace[0]) { 488 int q; 489 seq_printf(m, "%i %li %li", 490 lr->count, lr->time, lr->max); 491 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 492 unsigned long bt = lr->backtrace[q]; 493 if (!bt) 494 break; 495 if (bt == ULONG_MAX) 496 break; 497 seq_printf(m, " %ps", (void *)bt); 498 } 499 seq_putc(m, '\n'); 500 } 501 502 } 503 put_task_struct(task); 504 return 0; 505 } 506 507 static int lstats_open(struct inode *inode, struct file *file) 508 { 509 return single_open(file, lstats_show_proc, inode); 510 } 511 512 static ssize_t lstats_write(struct file *file, const char __user *buf, 513 size_t count, loff_t *offs) 514 { 515 struct task_struct *task = get_proc_task(file_inode(file)); 516 517 if (!task) 518 return -ESRCH; 519 clear_all_latency_tracing(task); 520 put_task_struct(task); 521 522 return count; 523 } 524 525 static const struct file_operations proc_lstats_operations = { 526 .open = lstats_open, 527 .read = seq_read, 528 .write = lstats_write, 529 .llseek = seq_lseek, 530 .release = single_release, 531 }; 532 533 #endif 534 535 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns, 536 struct pid *pid, struct task_struct *task) 537 { 538 unsigned long totalpages = totalram_pages + total_swap_pages; 539 unsigned long points = 0; 540 541 points = oom_badness(task, NULL, NULL, totalpages) * 542 1000 / totalpages; 543 seq_printf(m, "%lu\n", points); 544 545 return 0; 546 } 547 548 struct limit_names { 549 const char *name; 550 const char *unit; 551 }; 552 553 static const struct limit_names lnames[RLIM_NLIMITS] = { 554 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 555 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 556 [RLIMIT_DATA] = {"Max data size", "bytes"}, 557 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 558 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 559 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 560 [RLIMIT_NPROC] = {"Max processes", "processes"}, 561 [RLIMIT_NOFILE] = {"Max open files", "files"}, 562 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 563 [RLIMIT_AS] = {"Max address space", "bytes"}, 564 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 565 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 566 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 567 [RLIMIT_NICE] = {"Max nice priority", NULL}, 568 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 569 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 570 }; 571 572 /* Display limits for a process */ 573 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns, 574 struct pid *pid, struct task_struct *task) 575 { 576 unsigned int i; 577 unsigned long flags; 578 579 struct rlimit rlim[RLIM_NLIMITS]; 580 581 if (!lock_task_sighand(task, &flags)) 582 return 0; 583 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 584 unlock_task_sighand(task, &flags); 585 586 /* 587 * print the file header 588 */ 589 seq_printf(m, "%-25s %-20s %-20s %-10s\n", 590 "Limit", "Soft Limit", "Hard Limit", "Units"); 591 592 for (i = 0; i < RLIM_NLIMITS; i++) { 593 if (rlim[i].rlim_cur == RLIM_INFINITY) 594 seq_printf(m, "%-25s %-20s ", 595 lnames[i].name, "unlimited"); 596 else 597 seq_printf(m, "%-25s %-20lu ", 598 lnames[i].name, rlim[i].rlim_cur); 599 600 if (rlim[i].rlim_max == RLIM_INFINITY) 601 seq_printf(m, "%-20s ", "unlimited"); 602 else 603 seq_printf(m, "%-20lu ", rlim[i].rlim_max); 604 605 if (lnames[i].unit) 606 seq_printf(m, "%-10s\n", lnames[i].unit); 607 else 608 seq_putc(m, '\n'); 609 } 610 611 return 0; 612 } 613 614 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 615 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns, 616 struct pid *pid, struct task_struct *task) 617 { 618 long nr; 619 unsigned long args[6], sp, pc; 620 int res; 621 622 res = lock_trace(task); 623 if (res) 624 return res; 625 626 if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) 627 seq_puts(m, "running\n"); 628 else if (nr < 0) 629 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc); 630 else 631 seq_printf(m, 632 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", 633 nr, 634 args[0], args[1], args[2], args[3], args[4], args[5], 635 sp, pc); 636 unlock_trace(task); 637 638 return 0; 639 } 640 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 641 642 /************************************************************************/ 643 /* Here the fs part begins */ 644 /************************************************************************/ 645 646 /* permission checks */ 647 static int proc_fd_access_allowed(struct inode *inode) 648 { 649 struct task_struct *task; 650 int allowed = 0; 651 /* Allow access to a task's file descriptors if it is us or we 652 * may use ptrace attach to the process and find out that 653 * information. 654 */ 655 task = get_proc_task(inode); 656 if (task) { 657 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 658 put_task_struct(task); 659 } 660 return allowed; 661 } 662 663 int proc_setattr(struct dentry *dentry, struct iattr *attr) 664 { 665 int error; 666 struct inode *inode = d_inode(dentry); 667 668 if (attr->ia_valid & ATTR_MODE) 669 return -EPERM; 670 671 error = setattr_prepare(dentry, attr); 672 if (error) 673 return error; 674 675 setattr_copy(inode, attr); 676 mark_inode_dirty(inode); 677 return 0; 678 } 679 680 /* 681 * May current process learn task's sched/cmdline info (for hide_pid_min=1) 682 * or euid/egid (for hide_pid_min=2)? 683 */ 684 static bool has_pid_permissions(struct pid_namespace *pid, 685 struct task_struct *task, 686 int hide_pid_min) 687 { 688 if (pid->hide_pid < hide_pid_min) 689 return true; 690 if (in_group_p(pid->pid_gid)) 691 return true; 692 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 693 } 694 695 696 static int proc_pid_permission(struct inode *inode, int mask) 697 { 698 struct pid_namespace *pid = inode->i_sb->s_fs_info; 699 struct task_struct *task; 700 bool has_perms; 701 702 task = get_proc_task(inode); 703 if (!task) 704 return -ESRCH; 705 has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS); 706 put_task_struct(task); 707 708 if (!has_perms) { 709 if (pid->hide_pid == HIDEPID_INVISIBLE) { 710 /* 711 * Let's make getdents(), stat(), and open() 712 * consistent with each other. If a process 713 * may not stat() a file, it shouldn't be seen 714 * in procfs at all. 715 */ 716 return -ENOENT; 717 } 718 719 return -EPERM; 720 } 721 return generic_permission(inode, mask); 722 } 723 724 725 726 static const struct inode_operations proc_def_inode_operations = { 727 .setattr = proc_setattr, 728 }; 729 730 static int proc_single_show(struct seq_file *m, void *v) 731 { 732 struct inode *inode = m->private; 733 struct pid_namespace *ns; 734 struct pid *pid; 735 struct task_struct *task; 736 int ret; 737 738 ns = inode->i_sb->s_fs_info; 739 pid = proc_pid(inode); 740 task = get_pid_task(pid, PIDTYPE_PID); 741 if (!task) 742 return -ESRCH; 743 744 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 745 746 put_task_struct(task); 747 return ret; 748 } 749 750 static int proc_single_open(struct inode *inode, struct file *filp) 751 { 752 return single_open(filp, proc_single_show, inode); 753 } 754 755 static const struct file_operations proc_single_file_operations = { 756 .open = proc_single_open, 757 .read = seq_read, 758 .llseek = seq_lseek, 759 .release = single_release, 760 }; 761 762 763 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode) 764 { 765 struct task_struct *task = get_proc_task(inode); 766 struct mm_struct *mm = ERR_PTR(-ESRCH); 767 768 if (task) { 769 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS); 770 put_task_struct(task); 771 772 if (!IS_ERR_OR_NULL(mm)) { 773 /* ensure this mm_struct can't be freed */ 774 mmgrab(mm); 775 /* but do not pin its memory */ 776 mmput(mm); 777 } 778 } 779 780 return mm; 781 } 782 783 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) 784 { 785 struct mm_struct *mm = proc_mem_open(inode, mode); 786 787 if (IS_ERR(mm)) 788 return PTR_ERR(mm); 789 790 file->private_data = mm; 791 return 0; 792 } 793 794 static int mem_open(struct inode *inode, struct file *file) 795 { 796 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH); 797 798 /* OK to pass negative loff_t, we can catch out-of-range */ 799 file->f_mode |= FMODE_UNSIGNED_OFFSET; 800 801 return ret; 802 } 803 804 static ssize_t mem_rw(struct file *file, char __user *buf, 805 size_t count, loff_t *ppos, int write) 806 { 807 struct mm_struct *mm = file->private_data; 808 unsigned long addr = *ppos; 809 ssize_t copied; 810 char *page; 811 unsigned int flags; 812 813 if (!mm) 814 return 0; 815 816 page = (char *)__get_free_page(GFP_TEMPORARY); 817 if (!page) 818 return -ENOMEM; 819 820 copied = 0; 821 if (!mmget_not_zero(mm)) 822 goto free; 823 824 flags = write ? FOLL_WRITE : 0; 825 826 while (count > 0) { 827 int this_len = min_t(int, count, PAGE_SIZE); 828 829 if (write && copy_from_user(page, buf, this_len)) { 830 copied = -EFAULT; 831 break; 832 } 833 834 this_len = access_remote_vm(mm, addr, page, this_len, flags); 835 if (!this_len) { 836 if (!copied) 837 copied = -EIO; 838 break; 839 } 840 841 if (!write && copy_to_user(buf, page, this_len)) { 842 copied = -EFAULT; 843 break; 844 } 845 846 buf += this_len; 847 addr += this_len; 848 copied += this_len; 849 count -= this_len; 850 } 851 *ppos = addr; 852 853 mmput(mm); 854 free: 855 free_page((unsigned long) page); 856 return copied; 857 } 858 859 static ssize_t mem_read(struct file *file, char __user *buf, 860 size_t count, loff_t *ppos) 861 { 862 return mem_rw(file, buf, count, ppos, 0); 863 } 864 865 static ssize_t mem_write(struct file *file, const char __user *buf, 866 size_t count, loff_t *ppos) 867 { 868 return mem_rw(file, (char __user*)buf, count, ppos, 1); 869 } 870 871 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 872 { 873 switch (orig) { 874 case 0: 875 file->f_pos = offset; 876 break; 877 case 1: 878 file->f_pos += offset; 879 break; 880 default: 881 return -EINVAL; 882 } 883 force_successful_syscall_return(); 884 return file->f_pos; 885 } 886 887 static int mem_release(struct inode *inode, struct file *file) 888 { 889 struct mm_struct *mm = file->private_data; 890 if (mm) 891 mmdrop(mm); 892 return 0; 893 } 894 895 static const struct file_operations proc_mem_operations = { 896 .llseek = mem_lseek, 897 .read = mem_read, 898 .write = mem_write, 899 .open = mem_open, 900 .release = mem_release, 901 }; 902 903 static int environ_open(struct inode *inode, struct file *file) 904 { 905 return __mem_open(inode, file, PTRACE_MODE_READ); 906 } 907 908 static ssize_t environ_read(struct file *file, char __user *buf, 909 size_t count, loff_t *ppos) 910 { 911 char *page; 912 unsigned long src = *ppos; 913 int ret = 0; 914 struct mm_struct *mm = file->private_data; 915 unsigned long env_start, env_end; 916 917 /* Ensure the process spawned far enough to have an environment. */ 918 if (!mm || !mm->env_end) 919 return 0; 920 921 page = (char *)__get_free_page(GFP_TEMPORARY); 922 if (!page) 923 return -ENOMEM; 924 925 ret = 0; 926 if (!mmget_not_zero(mm)) 927 goto free; 928 929 down_read(&mm->mmap_sem); 930 env_start = mm->env_start; 931 env_end = mm->env_end; 932 up_read(&mm->mmap_sem); 933 934 while (count > 0) { 935 size_t this_len, max_len; 936 int retval; 937 938 if (src >= (env_end - env_start)) 939 break; 940 941 this_len = env_end - (env_start + src); 942 943 max_len = min_t(size_t, PAGE_SIZE, count); 944 this_len = min(max_len, this_len); 945 946 retval = access_remote_vm(mm, (env_start + src), page, this_len, 0); 947 948 if (retval <= 0) { 949 ret = retval; 950 break; 951 } 952 953 if (copy_to_user(buf, page, retval)) { 954 ret = -EFAULT; 955 break; 956 } 957 958 ret += retval; 959 src += retval; 960 buf += retval; 961 count -= retval; 962 } 963 *ppos = src; 964 mmput(mm); 965 966 free: 967 free_page((unsigned long) page); 968 return ret; 969 } 970 971 static const struct file_operations proc_environ_operations = { 972 .open = environ_open, 973 .read = environ_read, 974 .llseek = generic_file_llseek, 975 .release = mem_release, 976 }; 977 978 static int auxv_open(struct inode *inode, struct file *file) 979 { 980 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS); 981 } 982 983 static ssize_t auxv_read(struct file *file, char __user *buf, 984 size_t count, loff_t *ppos) 985 { 986 struct mm_struct *mm = file->private_data; 987 unsigned int nwords = 0; 988 989 if (!mm) 990 return 0; 991 do { 992 nwords += 2; 993 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 994 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv, 995 nwords * sizeof(mm->saved_auxv[0])); 996 } 997 998 static const struct file_operations proc_auxv_operations = { 999 .open = auxv_open, 1000 .read = auxv_read, 1001 .llseek = generic_file_llseek, 1002 .release = mem_release, 1003 }; 1004 1005 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count, 1006 loff_t *ppos) 1007 { 1008 struct task_struct *task = get_proc_task(file_inode(file)); 1009 char buffer[PROC_NUMBUF]; 1010 int oom_adj = OOM_ADJUST_MIN; 1011 size_t len; 1012 1013 if (!task) 1014 return -ESRCH; 1015 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX) 1016 oom_adj = OOM_ADJUST_MAX; 1017 else 1018 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) / 1019 OOM_SCORE_ADJ_MAX; 1020 put_task_struct(task); 1021 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj); 1022 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1023 } 1024 1025 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy) 1026 { 1027 static DEFINE_MUTEX(oom_adj_mutex); 1028 struct mm_struct *mm = NULL; 1029 struct task_struct *task; 1030 int err = 0; 1031 1032 task = get_proc_task(file_inode(file)); 1033 if (!task) 1034 return -ESRCH; 1035 1036 mutex_lock(&oom_adj_mutex); 1037 if (legacy) { 1038 if (oom_adj < task->signal->oom_score_adj && 1039 !capable(CAP_SYS_RESOURCE)) { 1040 err = -EACCES; 1041 goto err_unlock; 1042 } 1043 /* 1044 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use 1045 * /proc/pid/oom_score_adj instead. 1046 */ 1047 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 1048 current->comm, task_pid_nr(current), task_pid_nr(task), 1049 task_pid_nr(task)); 1050 } else { 1051 if ((short)oom_adj < task->signal->oom_score_adj_min && 1052 !capable(CAP_SYS_RESOURCE)) { 1053 err = -EACCES; 1054 goto err_unlock; 1055 } 1056 } 1057 1058 /* 1059 * Make sure we will check other processes sharing the mm if this is 1060 * not vfrok which wants its own oom_score_adj. 1061 * pin the mm so it doesn't go away and get reused after task_unlock 1062 */ 1063 if (!task->vfork_done) { 1064 struct task_struct *p = find_lock_task_mm(task); 1065 1066 if (p) { 1067 if (atomic_read(&p->mm->mm_users) > 1) { 1068 mm = p->mm; 1069 mmgrab(mm); 1070 } 1071 task_unlock(p); 1072 } 1073 } 1074 1075 task->signal->oom_score_adj = oom_adj; 1076 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1077 task->signal->oom_score_adj_min = (short)oom_adj; 1078 trace_oom_score_adj_update(task); 1079 1080 if (mm) { 1081 struct task_struct *p; 1082 1083 rcu_read_lock(); 1084 for_each_process(p) { 1085 if (same_thread_group(task, p)) 1086 continue; 1087 1088 /* do not touch kernel threads or the global init */ 1089 if (p->flags & PF_KTHREAD || is_global_init(p)) 1090 continue; 1091 1092 task_lock(p); 1093 if (!p->vfork_done && process_shares_mm(p, mm)) { 1094 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", 1095 task_pid_nr(p), p->comm, 1096 p->signal->oom_score_adj, oom_adj, 1097 task_pid_nr(task), task->comm); 1098 p->signal->oom_score_adj = oom_adj; 1099 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1100 p->signal->oom_score_adj_min = (short)oom_adj; 1101 } 1102 task_unlock(p); 1103 } 1104 rcu_read_unlock(); 1105 mmdrop(mm); 1106 } 1107 err_unlock: 1108 mutex_unlock(&oom_adj_mutex); 1109 put_task_struct(task); 1110 return err; 1111 } 1112 1113 /* 1114 * /proc/pid/oom_adj exists solely for backwards compatibility with previous 1115 * kernels. The effective policy is defined by oom_score_adj, which has a 1116 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly. 1117 * Values written to oom_adj are simply mapped linearly to oom_score_adj. 1118 * Processes that become oom disabled via oom_adj will still be oom disabled 1119 * with this implementation. 1120 * 1121 * oom_adj cannot be removed since existing userspace binaries use it. 1122 */ 1123 static ssize_t oom_adj_write(struct file *file, const char __user *buf, 1124 size_t count, loff_t *ppos) 1125 { 1126 char buffer[PROC_NUMBUF]; 1127 int oom_adj; 1128 int err; 1129 1130 memset(buffer, 0, sizeof(buffer)); 1131 if (count > sizeof(buffer) - 1) 1132 count = sizeof(buffer) - 1; 1133 if (copy_from_user(buffer, buf, count)) { 1134 err = -EFAULT; 1135 goto out; 1136 } 1137 1138 err = kstrtoint(strstrip(buffer), 0, &oom_adj); 1139 if (err) 1140 goto out; 1141 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) && 1142 oom_adj != OOM_DISABLE) { 1143 err = -EINVAL; 1144 goto out; 1145 } 1146 1147 /* 1148 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 1149 * value is always attainable. 1150 */ 1151 if (oom_adj == OOM_ADJUST_MAX) 1152 oom_adj = OOM_SCORE_ADJ_MAX; 1153 else 1154 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE; 1155 1156 err = __set_oom_adj(file, oom_adj, true); 1157 out: 1158 return err < 0 ? err : count; 1159 } 1160 1161 static const struct file_operations proc_oom_adj_operations = { 1162 .read = oom_adj_read, 1163 .write = oom_adj_write, 1164 .llseek = generic_file_llseek, 1165 }; 1166 1167 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 1168 size_t count, loff_t *ppos) 1169 { 1170 struct task_struct *task = get_proc_task(file_inode(file)); 1171 char buffer[PROC_NUMBUF]; 1172 short oom_score_adj = OOM_SCORE_ADJ_MIN; 1173 size_t len; 1174 1175 if (!task) 1176 return -ESRCH; 1177 oom_score_adj = task->signal->oom_score_adj; 1178 put_task_struct(task); 1179 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj); 1180 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1181 } 1182 1183 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1184 size_t count, loff_t *ppos) 1185 { 1186 char buffer[PROC_NUMBUF]; 1187 int oom_score_adj; 1188 int err; 1189 1190 memset(buffer, 0, sizeof(buffer)); 1191 if (count > sizeof(buffer) - 1) 1192 count = sizeof(buffer) - 1; 1193 if (copy_from_user(buffer, buf, count)) { 1194 err = -EFAULT; 1195 goto out; 1196 } 1197 1198 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 1199 if (err) 1200 goto out; 1201 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1202 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1203 err = -EINVAL; 1204 goto out; 1205 } 1206 1207 err = __set_oom_adj(file, oom_score_adj, false); 1208 out: 1209 return err < 0 ? err : count; 1210 } 1211 1212 static const struct file_operations proc_oom_score_adj_operations = { 1213 .read = oom_score_adj_read, 1214 .write = oom_score_adj_write, 1215 .llseek = default_llseek, 1216 }; 1217 1218 #ifdef CONFIG_AUDITSYSCALL 1219 #define TMPBUFLEN 11 1220 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1221 size_t count, loff_t *ppos) 1222 { 1223 struct inode * inode = file_inode(file); 1224 struct task_struct *task = get_proc_task(inode); 1225 ssize_t length; 1226 char tmpbuf[TMPBUFLEN]; 1227 1228 if (!task) 1229 return -ESRCH; 1230 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1231 from_kuid(file->f_cred->user_ns, 1232 audit_get_loginuid(task))); 1233 put_task_struct(task); 1234 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1235 } 1236 1237 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1238 size_t count, loff_t *ppos) 1239 { 1240 struct inode * inode = file_inode(file); 1241 uid_t loginuid; 1242 kuid_t kloginuid; 1243 int rv; 1244 1245 rcu_read_lock(); 1246 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1247 rcu_read_unlock(); 1248 return -EPERM; 1249 } 1250 rcu_read_unlock(); 1251 1252 if (*ppos != 0) { 1253 /* No partial writes. */ 1254 return -EINVAL; 1255 } 1256 1257 rv = kstrtou32_from_user(buf, count, 10, &loginuid); 1258 if (rv < 0) 1259 return rv; 1260 1261 /* is userspace tring to explicitly UNSET the loginuid? */ 1262 if (loginuid == AUDIT_UID_UNSET) { 1263 kloginuid = INVALID_UID; 1264 } else { 1265 kloginuid = make_kuid(file->f_cred->user_ns, loginuid); 1266 if (!uid_valid(kloginuid)) 1267 return -EINVAL; 1268 } 1269 1270 rv = audit_set_loginuid(kloginuid); 1271 if (rv < 0) 1272 return rv; 1273 return count; 1274 } 1275 1276 static const struct file_operations proc_loginuid_operations = { 1277 .read = proc_loginuid_read, 1278 .write = proc_loginuid_write, 1279 .llseek = generic_file_llseek, 1280 }; 1281 1282 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1283 size_t count, loff_t *ppos) 1284 { 1285 struct inode * inode = file_inode(file); 1286 struct task_struct *task = get_proc_task(inode); 1287 ssize_t length; 1288 char tmpbuf[TMPBUFLEN]; 1289 1290 if (!task) 1291 return -ESRCH; 1292 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1293 audit_get_sessionid(task)); 1294 put_task_struct(task); 1295 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1296 } 1297 1298 static const struct file_operations proc_sessionid_operations = { 1299 .read = proc_sessionid_read, 1300 .llseek = generic_file_llseek, 1301 }; 1302 #endif 1303 1304 #ifdef CONFIG_FAULT_INJECTION 1305 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1306 size_t count, loff_t *ppos) 1307 { 1308 struct task_struct *task = get_proc_task(file_inode(file)); 1309 char buffer[PROC_NUMBUF]; 1310 size_t len; 1311 int make_it_fail; 1312 1313 if (!task) 1314 return -ESRCH; 1315 make_it_fail = task->make_it_fail; 1316 put_task_struct(task); 1317 1318 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1319 1320 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1321 } 1322 1323 static ssize_t proc_fault_inject_write(struct file * file, 1324 const char __user * buf, size_t count, loff_t *ppos) 1325 { 1326 struct task_struct *task; 1327 char buffer[PROC_NUMBUF]; 1328 int make_it_fail; 1329 int rv; 1330 1331 if (!capable(CAP_SYS_RESOURCE)) 1332 return -EPERM; 1333 memset(buffer, 0, sizeof(buffer)); 1334 if (count > sizeof(buffer) - 1) 1335 count = sizeof(buffer) - 1; 1336 if (copy_from_user(buffer, buf, count)) 1337 return -EFAULT; 1338 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail); 1339 if (rv < 0) 1340 return rv; 1341 if (make_it_fail < 0 || make_it_fail > 1) 1342 return -EINVAL; 1343 1344 task = get_proc_task(file_inode(file)); 1345 if (!task) 1346 return -ESRCH; 1347 task->make_it_fail = make_it_fail; 1348 put_task_struct(task); 1349 1350 return count; 1351 } 1352 1353 static const struct file_operations proc_fault_inject_operations = { 1354 .read = proc_fault_inject_read, 1355 .write = proc_fault_inject_write, 1356 .llseek = generic_file_llseek, 1357 }; 1358 #endif 1359 1360 1361 #ifdef CONFIG_SCHED_DEBUG 1362 /* 1363 * Print out various scheduling related per-task fields: 1364 */ 1365 static int sched_show(struct seq_file *m, void *v) 1366 { 1367 struct inode *inode = m->private; 1368 struct task_struct *p; 1369 1370 p = get_proc_task(inode); 1371 if (!p) 1372 return -ESRCH; 1373 proc_sched_show_task(p, m); 1374 1375 put_task_struct(p); 1376 1377 return 0; 1378 } 1379 1380 static ssize_t 1381 sched_write(struct file *file, const char __user *buf, 1382 size_t count, loff_t *offset) 1383 { 1384 struct inode *inode = file_inode(file); 1385 struct task_struct *p; 1386 1387 p = get_proc_task(inode); 1388 if (!p) 1389 return -ESRCH; 1390 proc_sched_set_task(p); 1391 1392 put_task_struct(p); 1393 1394 return count; 1395 } 1396 1397 static int sched_open(struct inode *inode, struct file *filp) 1398 { 1399 return single_open(filp, sched_show, inode); 1400 } 1401 1402 static const struct file_operations proc_pid_sched_operations = { 1403 .open = sched_open, 1404 .read = seq_read, 1405 .write = sched_write, 1406 .llseek = seq_lseek, 1407 .release = single_release, 1408 }; 1409 1410 #endif 1411 1412 #ifdef CONFIG_SCHED_AUTOGROUP 1413 /* 1414 * Print out autogroup related information: 1415 */ 1416 static int sched_autogroup_show(struct seq_file *m, void *v) 1417 { 1418 struct inode *inode = m->private; 1419 struct task_struct *p; 1420 1421 p = get_proc_task(inode); 1422 if (!p) 1423 return -ESRCH; 1424 proc_sched_autogroup_show_task(p, m); 1425 1426 put_task_struct(p); 1427 1428 return 0; 1429 } 1430 1431 static ssize_t 1432 sched_autogroup_write(struct file *file, const char __user *buf, 1433 size_t count, loff_t *offset) 1434 { 1435 struct inode *inode = file_inode(file); 1436 struct task_struct *p; 1437 char buffer[PROC_NUMBUF]; 1438 int nice; 1439 int err; 1440 1441 memset(buffer, 0, sizeof(buffer)); 1442 if (count > sizeof(buffer) - 1) 1443 count = sizeof(buffer) - 1; 1444 if (copy_from_user(buffer, buf, count)) 1445 return -EFAULT; 1446 1447 err = kstrtoint(strstrip(buffer), 0, &nice); 1448 if (err < 0) 1449 return err; 1450 1451 p = get_proc_task(inode); 1452 if (!p) 1453 return -ESRCH; 1454 1455 err = proc_sched_autogroup_set_nice(p, nice); 1456 if (err) 1457 count = err; 1458 1459 put_task_struct(p); 1460 1461 return count; 1462 } 1463 1464 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1465 { 1466 int ret; 1467 1468 ret = single_open(filp, sched_autogroup_show, NULL); 1469 if (!ret) { 1470 struct seq_file *m = filp->private_data; 1471 1472 m->private = inode; 1473 } 1474 return ret; 1475 } 1476 1477 static const struct file_operations proc_pid_sched_autogroup_operations = { 1478 .open = sched_autogroup_open, 1479 .read = seq_read, 1480 .write = sched_autogroup_write, 1481 .llseek = seq_lseek, 1482 .release = single_release, 1483 }; 1484 1485 #endif /* CONFIG_SCHED_AUTOGROUP */ 1486 1487 static ssize_t comm_write(struct file *file, const char __user *buf, 1488 size_t count, loff_t *offset) 1489 { 1490 struct inode *inode = file_inode(file); 1491 struct task_struct *p; 1492 char buffer[TASK_COMM_LEN]; 1493 const size_t maxlen = sizeof(buffer) - 1; 1494 1495 memset(buffer, 0, sizeof(buffer)); 1496 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count)) 1497 return -EFAULT; 1498 1499 p = get_proc_task(inode); 1500 if (!p) 1501 return -ESRCH; 1502 1503 if (same_thread_group(current, p)) 1504 set_task_comm(p, buffer); 1505 else 1506 count = -EINVAL; 1507 1508 put_task_struct(p); 1509 1510 return count; 1511 } 1512 1513 static int comm_show(struct seq_file *m, void *v) 1514 { 1515 struct inode *inode = m->private; 1516 struct task_struct *p; 1517 1518 p = get_proc_task(inode); 1519 if (!p) 1520 return -ESRCH; 1521 1522 task_lock(p); 1523 seq_printf(m, "%s\n", p->comm); 1524 task_unlock(p); 1525 1526 put_task_struct(p); 1527 1528 return 0; 1529 } 1530 1531 static int comm_open(struct inode *inode, struct file *filp) 1532 { 1533 return single_open(filp, comm_show, inode); 1534 } 1535 1536 static const struct file_operations proc_pid_set_comm_operations = { 1537 .open = comm_open, 1538 .read = seq_read, 1539 .write = comm_write, 1540 .llseek = seq_lseek, 1541 .release = single_release, 1542 }; 1543 1544 static int proc_exe_link(struct dentry *dentry, struct path *exe_path) 1545 { 1546 struct task_struct *task; 1547 struct file *exe_file; 1548 1549 task = get_proc_task(d_inode(dentry)); 1550 if (!task) 1551 return -ENOENT; 1552 exe_file = get_task_exe_file(task); 1553 put_task_struct(task); 1554 if (exe_file) { 1555 *exe_path = exe_file->f_path; 1556 path_get(&exe_file->f_path); 1557 fput(exe_file); 1558 return 0; 1559 } else 1560 return -ENOENT; 1561 } 1562 1563 static const char *proc_pid_get_link(struct dentry *dentry, 1564 struct inode *inode, 1565 struct delayed_call *done) 1566 { 1567 struct path path; 1568 int error = -EACCES; 1569 1570 if (!dentry) 1571 return ERR_PTR(-ECHILD); 1572 1573 /* Are we allowed to snoop on the tasks file descriptors? */ 1574 if (!proc_fd_access_allowed(inode)) 1575 goto out; 1576 1577 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1578 if (error) 1579 goto out; 1580 1581 nd_jump_link(&path); 1582 return NULL; 1583 out: 1584 return ERR_PTR(error); 1585 } 1586 1587 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1588 { 1589 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1590 char *pathname; 1591 int len; 1592 1593 if (!tmp) 1594 return -ENOMEM; 1595 1596 pathname = d_path(path, tmp, PAGE_SIZE); 1597 len = PTR_ERR(pathname); 1598 if (IS_ERR(pathname)) 1599 goto out; 1600 len = tmp + PAGE_SIZE - 1 - pathname; 1601 1602 if (len > buflen) 1603 len = buflen; 1604 if (copy_to_user(buffer, pathname, len)) 1605 len = -EFAULT; 1606 out: 1607 free_page((unsigned long)tmp); 1608 return len; 1609 } 1610 1611 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1612 { 1613 int error = -EACCES; 1614 struct inode *inode = d_inode(dentry); 1615 struct path path; 1616 1617 /* Are we allowed to snoop on the tasks file descriptors? */ 1618 if (!proc_fd_access_allowed(inode)) 1619 goto out; 1620 1621 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1622 if (error) 1623 goto out; 1624 1625 error = do_proc_readlink(&path, buffer, buflen); 1626 path_put(&path); 1627 out: 1628 return error; 1629 } 1630 1631 const struct inode_operations proc_pid_link_inode_operations = { 1632 .readlink = proc_pid_readlink, 1633 .get_link = proc_pid_get_link, 1634 .setattr = proc_setattr, 1635 }; 1636 1637 1638 /* building an inode */ 1639 1640 void task_dump_owner(struct task_struct *task, mode_t mode, 1641 kuid_t *ruid, kgid_t *rgid) 1642 { 1643 /* Depending on the state of dumpable compute who should own a 1644 * proc file for a task. 1645 */ 1646 const struct cred *cred; 1647 kuid_t uid; 1648 kgid_t gid; 1649 1650 /* Default to the tasks effective ownership */ 1651 rcu_read_lock(); 1652 cred = __task_cred(task); 1653 uid = cred->euid; 1654 gid = cred->egid; 1655 rcu_read_unlock(); 1656 1657 /* 1658 * Before the /proc/pid/status file was created the only way to read 1659 * the effective uid of a /process was to stat /proc/pid. Reading 1660 * /proc/pid/status is slow enough that procps and other packages 1661 * kept stating /proc/pid. To keep the rules in /proc simple I have 1662 * made this apply to all per process world readable and executable 1663 * directories. 1664 */ 1665 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) { 1666 struct mm_struct *mm; 1667 task_lock(task); 1668 mm = task->mm; 1669 /* Make non-dumpable tasks owned by some root */ 1670 if (mm) { 1671 if (get_dumpable(mm) != SUID_DUMP_USER) { 1672 struct user_namespace *user_ns = mm->user_ns; 1673 1674 uid = make_kuid(user_ns, 0); 1675 if (!uid_valid(uid)) 1676 uid = GLOBAL_ROOT_UID; 1677 1678 gid = make_kgid(user_ns, 0); 1679 if (!gid_valid(gid)) 1680 gid = GLOBAL_ROOT_GID; 1681 } 1682 } else { 1683 uid = GLOBAL_ROOT_UID; 1684 gid = GLOBAL_ROOT_GID; 1685 } 1686 task_unlock(task); 1687 } 1688 *ruid = uid; 1689 *rgid = gid; 1690 } 1691 1692 struct inode *proc_pid_make_inode(struct super_block * sb, 1693 struct task_struct *task, umode_t mode) 1694 { 1695 struct inode * inode; 1696 struct proc_inode *ei; 1697 1698 /* We need a new inode */ 1699 1700 inode = new_inode(sb); 1701 if (!inode) 1702 goto out; 1703 1704 /* Common stuff */ 1705 ei = PROC_I(inode); 1706 inode->i_mode = mode; 1707 inode->i_ino = get_next_ino(); 1708 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 1709 inode->i_op = &proc_def_inode_operations; 1710 1711 /* 1712 * grab the reference to task. 1713 */ 1714 ei->pid = get_task_pid(task, PIDTYPE_PID); 1715 if (!ei->pid) 1716 goto out_unlock; 1717 1718 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); 1719 security_task_to_inode(task, inode); 1720 1721 out: 1722 return inode; 1723 1724 out_unlock: 1725 iput(inode); 1726 return NULL; 1727 } 1728 1729 int pid_getattr(const struct path *path, struct kstat *stat, 1730 u32 request_mask, unsigned int query_flags) 1731 { 1732 struct inode *inode = d_inode(path->dentry); 1733 struct task_struct *task; 1734 struct pid_namespace *pid = path->dentry->d_sb->s_fs_info; 1735 1736 generic_fillattr(inode, stat); 1737 1738 rcu_read_lock(); 1739 stat->uid = GLOBAL_ROOT_UID; 1740 stat->gid = GLOBAL_ROOT_GID; 1741 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1742 if (task) { 1743 if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) { 1744 rcu_read_unlock(); 1745 /* 1746 * This doesn't prevent learning whether PID exists, 1747 * it only makes getattr() consistent with readdir(). 1748 */ 1749 return -ENOENT; 1750 } 1751 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid); 1752 } 1753 rcu_read_unlock(); 1754 return 0; 1755 } 1756 1757 /* dentry stuff */ 1758 1759 /* 1760 * Exceptional case: normally we are not allowed to unhash a busy 1761 * directory. In this case, however, we can do it - no aliasing problems 1762 * due to the way we treat inodes. 1763 * 1764 * Rewrite the inode's ownerships here because the owning task may have 1765 * performed a setuid(), etc. 1766 * 1767 */ 1768 int pid_revalidate(struct dentry *dentry, unsigned int flags) 1769 { 1770 struct inode *inode; 1771 struct task_struct *task; 1772 1773 if (flags & LOOKUP_RCU) 1774 return -ECHILD; 1775 1776 inode = d_inode(dentry); 1777 task = get_proc_task(inode); 1778 1779 if (task) { 1780 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid); 1781 1782 inode->i_mode &= ~(S_ISUID | S_ISGID); 1783 security_task_to_inode(task, inode); 1784 put_task_struct(task); 1785 return 1; 1786 } 1787 return 0; 1788 } 1789 1790 static inline bool proc_inode_is_dead(struct inode *inode) 1791 { 1792 return !proc_pid(inode)->tasks[PIDTYPE_PID].first; 1793 } 1794 1795 int pid_delete_dentry(const struct dentry *dentry) 1796 { 1797 /* Is the task we represent dead? 1798 * If so, then don't put the dentry on the lru list, 1799 * kill it immediately. 1800 */ 1801 return proc_inode_is_dead(d_inode(dentry)); 1802 } 1803 1804 const struct dentry_operations pid_dentry_operations = 1805 { 1806 .d_revalidate = pid_revalidate, 1807 .d_delete = pid_delete_dentry, 1808 }; 1809 1810 /* Lookups */ 1811 1812 /* 1813 * Fill a directory entry. 1814 * 1815 * If possible create the dcache entry and derive our inode number and 1816 * file type from dcache entry. 1817 * 1818 * Since all of the proc inode numbers are dynamically generated, the inode 1819 * numbers do not exist until the inode is cache. This means creating the 1820 * the dcache entry in readdir is necessary to keep the inode numbers 1821 * reported by readdir in sync with the inode numbers reported 1822 * by stat. 1823 */ 1824 bool proc_fill_cache(struct file *file, struct dir_context *ctx, 1825 const char *name, int len, 1826 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1827 { 1828 struct dentry *child, *dir = file->f_path.dentry; 1829 struct qstr qname = QSTR_INIT(name, len); 1830 struct inode *inode; 1831 unsigned type; 1832 ino_t ino; 1833 1834 child = d_hash_and_lookup(dir, &qname); 1835 if (!child) { 1836 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 1837 child = d_alloc_parallel(dir, &qname, &wq); 1838 if (IS_ERR(child)) 1839 goto end_instantiate; 1840 if (d_in_lookup(child)) { 1841 int err = instantiate(d_inode(dir), child, task, ptr); 1842 d_lookup_done(child); 1843 if (err < 0) { 1844 dput(child); 1845 goto end_instantiate; 1846 } 1847 } 1848 } 1849 inode = d_inode(child); 1850 ino = inode->i_ino; 1851 type = inode->i_mode >> 12; 1852 dput(child); 1853 return dir_emit(ctx, name, len, ino, type); 1854 1855 end_instantiate: 1856 return dir_emit(ctx, name, len, 1, DT_UNKNOWN); 1857 } 1858 1859 /* 1860 * dname_to_vma_addr - maps a dentry name into two unsigned longs 1861 * which represent vma start and end addresses. 1862 */ 1863 static int dname_to_vma_addr(struct dentry *dentry, 1864 unsigned long *start, unsigned long *end) 1865 { 1866 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2) 1867 return -EINVAL; 1868 1869 return 0; 1870 } 1871 1872 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags) 1873 { 1874 unsigned long vm_start, vm_end; 1875 bool exact_vma_exists = false; 1876 struct mm_struct *mm = NULL; 1877 struct task_struct *task; 1878 struct inode *inode; 1879 int status = 0; 1880 1881 if (flags & LOOKUP_RCU) 1882 return -ECHILD; 1883 1884 inode = d_inode(dentry); 1885 task = get_proc_task(inode); 1886 if (!task) 1887 goto out_notask; 1888 1889 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); 1890 if (IS_ERR_OR_NULL(mm)) 1891 goto out; 1892 1893 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 1894 down_read(&mm->mmap_sem); 1895 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end); 1896 up_read(&mm->mmap_sem); 1897 } 1898 1899 mmput(mm); 1900 1901 if (exact_vma_exists) { 1902 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); 1903 1904 security_task_to_inode(task, inode); 1905 status = 1; 1906 } 1907 1908 out: 1909 put_task_struct(task); 1910 1911 out_notask: 1912 return status; 1913 } 1914 1915 static const struct dentry_operations tid_map_files_dentry_operations = { 1916 .d_revalidate = map_files_d_revalidate, 1917 .d_delete = pid_delete_dentry, 1918 }; 1919 1920 static int map_files_get_link(struct dentry *dentry, struct path *path) 1921 { 1922 unsigned long vm_start, vm_end; 1923 struct vm_area_struct *vma; 1924 struct task_struct *task; 1925 struct mm_struct *mm; 1926 int rc; 1927 1928 rc = -ENOENT; 1929 task = get_proc_task(d_inode(dentry)); 1930 if (!task) 1931 goto out; 1932 1933 mm = get_task_mm(task); 1934 put_task_struct(task); 1935 if (!mm) 1936 goto out; 1937 1938 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 1939 if (rc) 1940 goto out_mmput; 1941 1942 rc = -ENOENT; 1943 down_read(&mm->mmap_sem); 1944 vma = find_exact_vma(mm, vm_start, vm_end); 1945 if (vma && vma->vm_file) { 1946 *path = vma->vm_file->f_path; 1947 path_get(path); 1948 rc = 0; 1949 } 1950 up_read(&mm->mmap_sem); 1951 1952 out_mmput: 1953 mmput(mm); 1954 out: 1955 return rc; 1956 } 1957 1958 struct map_files_info { 1959 fmode_t mode; 1960 unsigned int len; 1961 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */ 1962 }; 1963 1964 /* 1965 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the 1966 * symlinks may be used to bypass permissions on ancestor directories in the 1967 * path to the file in question. 1968 */ 1969 static const char * 1970 proc_map_files_get_link(struct dentry *dentry, 1971 struct inode *inode, 1972 struct delayed_call *done) 1973 { 1974 if (!capable(CAP_SYS_ADMIN)) 1975 return ERR_PTR(-EPERM); 1976 1977 return proc_pid_get_link(dentry, inode, done); 1978 } 1979 1980 /* 1981 * Identical to proc_pid_link_inode_operations except for get_link() 1982 */ 1983 static const struct inode_operations proc_map_files_link_inode_operations = { 1984 .readlink = proc_pid_readlink, 1985 .get_link = proc_map_files_get_link, 1986 .setattr = proc_setattr, 1987 }; 1988 1989 static int 1990 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry, 1991 struct task_struct *task, const void *ptr) 1992 { 1993 fmode_t mode = (fmode_t)(unsigned long)ptr; 1994 struct proc_inode *ei; 1995 struct inode *inode; 1996 1997 inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK | 1998 ((mode & FMODE_READ ) ? S_IRUSR : 0) | 1999 ((mode & FMODE_WRITE) ? S_IWUSR : 0)); 2000 if (!inode) 2001 return -ENOENT; 2002 2003 ei = PROC_I(inode); 2004 ei->op.proc_get_link = map_files_get_link; 2005 2006 inode->i_op = &proc_map_files_link_inode_operations; 2007 inode->i_size = 64; 2008 2009 d_set_d_op(dentry, &tid_map_files_dentry_operations); 2010 d_add(dentry, inode); 2011 2012 return 0; 2013 } 2014 2015 static struct dentry *proc_map_files_lookup(struct inode *dir, 2016 struct dentry *dentry, unsigned int flags) 2017 { 2018 unsigned long vm_start, vm_end; 2019 struct vm_area_struct *vma; 2020 struct task_struct *task; 2021 int result; 2022 struct mm_struct *mm; 2023 2024 result = -ENOENT; 2025 task = get_proc_task(dir); 2026 if (!task) 2027 goto out; 2028 2029 result = -EACCES; 2030 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2031 goto out_put_task; 2032 2033 result = -ENOENT; 2034 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 2035 goto out_put_task; 2036 2037 mm = get_task_mm(task); 2038 if (!mm) 2039 goto out_put_task; 2040 2041 down_read(&mm->mmap_sem); 2042 vma = find_exact_vma(mm, vm_start, vm_end); 2043 if (!vma) 2044 goto out_no_vma; 2045 2046 if (vma->vm_file) 2047 result = proc_map_files_instantiate(dir, dentry, task, 2048 (void *)(unsigned long)vma->vm_file->f_mode); 2049 2050 out_no_vma: 2051 up_read(&mm->mmap_sem); 2052 mmput(mm); 2053 out_put_task: 2054 put_task_struct(task); 2055 out: 2056 return ERR_PTR(result); 2057 } 2058 2059 static const struct inode_operations proc_map_files_inode_operations = { 2060 .lookup = proc_map_files_lookup, 2061 .permission = proc_fd_permission, 2062 .setattr = proc_setattr, 2063 }; 2064 2065 static int 2066 proc_map_files_readdir(struct file *file, struct dir_context *ctx) 2067 { 2068 struct vm_area_struct *vma; 2069 struct task_struct *task; 2070 struct mm_struct *mm; 2071 unsigned long nr_files, pos, i; 2072 struct flex_array *fa = NULL; 2073 struct map_files_info info; 2074 struct map_files_info *p; 2075 int ret; 2076 2077 ret = -ENOENT; 2078 task = get_proc_task(file_inode(file)); 2079 if (!task) 2080 goto out; 2081 2082 ret = -EACCES; 2083 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2084 goto out_put_task; 2085 2086 ret = 0; 2087 if (!dir_emit_dots(file, ctx)) 2088 goto out_put_task; 2089 2090 mm = get_task_mm(task); 2091 if (!mm) 2092 goto out_put_task; 2093 down_read(&mm->mmap_sem); 2094 2095 nr_files = 0; 2096 2097 /* 2098 * We need two passes here: 2099 * 2100 * 1) Collect vmas of mapped files with mmap_sem taken 2101 * 2) Release mmap_sem and instantiate entries 2102 * 2103 * otherwise we get lockdep complained, since filldir() 2104 * routine might require mmap_sem taken in might_fault(). 2105 */ 2106 2107 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 2108 if (vma->vm_file && ++pos > ctx->pos) 2109 nr_files++; 2110 } 2111 2112 if (nr_files) { 2113 fa = flex_array_alloc(sizeof(info), nr_files, 2114 GFP_KERNEL); 2115 if (!fa || flex_array_prealloc(fa, 0, nr_files, 2116 GFP_KERNEL)) { 2117 ret = -ENOMEM; 2118 if (fa) 2119 flex_array_free(fa); 2120 up_read(&mm->mmap_sem); 2121 mmput(mm); 2122 goto out_put_task; 2123 } 2124 for (i = 0, vma = mm->mmap, pos = 2; vma; 2125 vma = vma->vm_next) { 2126 if (!vma->vm_file) 2127 continue; 2128 if (++pos <= ctx->pos) 2129 continue; 2130 2131 info.mode = vma->vm_file->f_mode; 2132 info.len = snprintf(info.name, 2133 sizeof(info.name), "%lx-%lx", 2134 vma->vm_start, vma->vm_end); 2135 if (flex_array_put(fa, i++, &info, GFP_KERNEL)) 2136 BUG(); 2137 } 2138 } 2139 up_read(&mm->mmap_sem); 2140 2141 for (i = 0; i < nr_files; i++) { 2142 p = flex_array_get(fa, i); 2143 if (!proc_fill_cache(file, ctx, 2144 p->name, p->len, 2145 proc_map_files_instantiate, 2146 task, 2147 (void *)(unsigned long)p->mode)) 2148 break; 2149 ctx->pos++; 2150 } 2151 if (fa) 2152 flex_array_free(fa); 2153 mmput(mm); 2154 2155 out_put_task: 2156 put_task_struct(task); 2157 out: 2158 return ret; 2159 } 2160 2161 static const struct file_operations proc_map_files_operations = { 2162 .read = generic_read_dir, 2163 .iterate_shared = proc_map_files_readdir, 2164 .llseek = generic_file_llseek, 2165 }; 2166 2167 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS) 2168 struct timers_private { 2169 struct pid *pid; 2170 struct task_struct *task; 2171 struct sighand_struct *sighand; 2172 struct pid_namespace *ns; 2173 unsigned long flags; 2174 }; 2175 2176 static void *timers_start(struct seq_file *m, loff_t *pos) 2177 { 2178 struct timers_private *tp = m->private; 2179 2180 tp->task = get_pid_task(tp->pid, PIDTYPE_PID); 2181 if (!tp->task) 2182 return ERR_PTR(-ESRCH); 2183 2184 tp->sighand = lock_task_sighand(tp->task, &tp->flags); 2185 if (!tp->sighand) 2186 return ERR_PTR(-ESRCH); 2187 2188 return seq_list_start(&tp->task->signal->posix_timers, *pos); 2189 } 2190 2191 static void *timers_next(struct seq_file *m, void *v, loff_t *pos) 2192 { 2193 struct timers_private *tp = m->private; 2194 return seq_list_next(v, &tp->task->signal->posix_timers, pos); 2195 } 2196 2197 static void timers_stop(struct seq_file *m, void *v) 2198 { 2199 struct timers_private *tp = m->private; 2200 2201 if (tp->sighand) { 2202 unlock_task_sighand(tp->task, &tp->flags); 2203 tp->sighand = NULL; 2204 } 2205 2206 if (tp->task) { 2207 put_task_struct(tp->task); 2208 tp->task = NULL; 2209 } 2210 } 2211 2212 static int show_timer(struct seq_file *m, void *v) 2213 { 2214 struct k_itimer *timer; 2215 struct timers_private *tp = m->private; 2216 int notify; 2217 static const char * const nstr[] = { 2218 [SIGEV_SIGNAL] = "signal", 2219 [SIGEV_NONE] = "none", 2220 [SIGEV_THREAD] = "thread", 2221 }; 2222 2223 timer = list_entry((struct list_head *)v, struct k_itimer, list); 2224 notify = timer->it_sigev_notify; 2225 2226 seq_printf(m, "ID: %d\n", timer->it_id); 2227 seq_printf(m, "signal: %d/%p\n", 2228 timer->sigq->info.si_signo, 2229 timer->sigq->info.si_value.sival_ptr); 2230 seq_printf(m, "notify: %s/%s.%d\n", 2231 nstr[notify & ~SIGEV_THREAD_ID], 2232 (notify & SIGEV_THREAD_ID) ? "tid" : "pid", 2233 pid_nr_ns(timer->it_pid, tp->ns)); 2234 seq_printf(m, "ClockID: %d\n", timer->it_clock); 2235 2236 return 0; 2237 } 2238 2239 static const struct seq_operations proc_timers_seq_ops = { 2240 .start = timers_start, 2241 .next = timers_next, 2242 .stop = timers_stop, 2243 .show = show_timer, 2244 }; 2245 2246 static int proc_timers_open(struct inode *inode, struct file *file) 2247 { 2248 struct timers_private *tp; 2249 2250 tp = __seq_open_private(file, &proc_timers_seq_ops, 2251 sizeof(struct timers_private)); 2252 if (!tp) 2253 return -ENOMEM; 2254 2255 tp->pid = proc_pid(inode); 2256 tp->ns = inode->i_sb->s_fs_info; 2257 return 0; 2258 } 2259 2260 static const struct file_operations proc_timers_operations = { 2261 .open = proc_timers_open, 2262 .read = seq_read, 2263 .llseek = seq_lseek, 2264 .release = seq_release_private, 2265 }; 2266 #endif 2267 2268 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf, 2269 size_t count, loff_t *offset) 2270 { 2271 struct inode *inode = file_inode(file); 2272 struct task_struct *p; 2273 u64 slack_ns; 2274 int err; 2275 2276 err = kstrtoull_from_user(buf, count, 10, &slack_ns); 2277 if (err < 0) 2278 return err; 2279 2280 p = get_proc_task(inode); 2281 if (!p) 2282 return -ESRCH; 2283 2284 if (p != current) { 2285 if (!capable(CAP_SYS_NICE)) { 2286 count = -EPERM; 2287 goto out; 2288 } 2289 2290 err = security_task_setscheduler(p); 2291 if (err) { 2292 count = err; 2293 goto out; 2294 } 2295 } 2296 2297 task_lock(p); 2298 if (slack_ns == 0) 2299 p->timer_slack_ns = p->default_timer_slack_ns; 2300 else 2301 p->timer_slack_ns = slack_ns; 2302 task_unlock(p); 2303 2304 out: 2305 put_task_struct(p); 2306 2307 return count; 2308 } 2309 2310 static int timerslack_ns_show(struct seq_file *m, void *v) 2311 { 2312 struct inode *inode = m->private; 2313 struct task_struct *p; 2314 int err = 0; 2315 2316 p = get_proc_task(inode); 2317 if (!p) 2318 return -ESRCH; 2319 2320 if (p != current) { 2321 2322 if (!capable(CAP_SYS_NICE)) { 2323 err = -EPERM; 2324 goto out; 2325 } 2326 err = security_task_getscheduler(p); 2327 if (err) 2328 goto out; 2329 } 2330 2331 task_lock(p); 2332 seq_printf(m, "%llu\n", p->timer_slack_ns); 2333 task_unlock(p); 2334 2335 out: 2336 put_task_struct(p); 2337 2338 return err; 2339 } 2340 2341 static int timerslack_ns_open(struct inode *inode, struct file *filp) 2342 { 2343 return single_open(filp, timerslack_ns_show, inode); 2344 } 2345 2346 static const struct file_operations proc_pid_set_timerslack_ns_operations = { 2347 .open = timerslack_ns_open, 2348 .read = seq_read, 2349 .write = timerslack_ns_write, 2350 .llseek = seq_lseek, 2351 .release = single_release, 2352 }; 2353 2354 static int proc_pident_instantiate(struct inode *dir, 2355 struct dentry *dentry, struct task_struct *task, const void *ptr) 2356 { 2357 const struct pid_entry *p = ptr; 2358 struct inode *inode; 2359 struct proc_inode *ei; 2360 2361 inode = proc_pid_make_inode(dir->i_sb, task, p->mode); 2362 if (!inode) 2363 goto out; 2364 2365 ei = PROC_I(inode); 2366 if (S_ISDIR(inode->i_mode)) 2367 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2368 if (p->iop) 2369 inode->i_op = p->iop; 2370 if (p->fop) 2371 inode->i_fop = p->fop; 2372 ei->op = p->op; 2373 d_set_d_op(dentry, &pid_dentry_operations); 2374 d_add(dentry, inode); 2375 /* Close the race of the process dying before we return the dentry */ 2376 if (pid_revalidate(dentry, 0)) 2377 return 0; 2378 out: 2379 return -ENOENT; 2380 } 2381 2382 static struct dentry *proc_pident_lookup(struct inode *dir, 2383 struct dentry *dentry, 2384 const struct pid_entry *ents, 2385 unsigned int nents) 2386 { 2387 int error; 2388 struct task_struct *task = get_proc_task(dir); 2389 const struct pid_entry *p, *last; 2390 2391 error = -ENOENT; 2392 2393 if (!task) 2394 goto out_no_task; 2395 2396 /* 2397 * Yes, it does not scale. And it should not. Don't add 2398 * new entries into /proc/<tgid>/ without very good reasons. 2399 */ 2400 last = &ents[nents]; 2401 for (p = ents; p < last; p++) { 2402 if (p->len != dentry->d_name.len) 2403 continue; 2404 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2405 break; 2406 } 2407 if (p >= last) 2408 goto out; 2409 2410 error = proc_pident_instantiate(dir, dentry, task, p); 2411 out: 2412 put_task_struct(task); 2413 out_no_task: 2414 return ERR_PTR(error); 2415 } 2416 2417 static int proc_pident_readdir(struct file *file, struct dir_context *ctx, 2418 const struct pid_entry *ents, unsigned int nents) 2419 { 2420 struct task_struct *task = get_proc_task(file_inode(file)); 2421 const struct pid_entry *p; 2422 2423 if (!task) 2424 return -ENOENT; 2425 2426 if (!dir_emit_dots(file, ctx)) 2427 goto out; 2428 2429 if (ctx->pos >= nents + 2) 2430 goto out; 2431 2432 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) { 2433 if (!proc_fill_cache(file, ctx, p->name, p->len, 2434 proc_pident_instantiate, task, p)) 2435 break; 2436 ctx->pos++; 2437 } 2438 out: 2439 put_task_struct(task); 2440 return 0; 2441 } 2442 2443 #ifdef CONFIG_SECURITY 2444 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2445 size_t count, loff_t *ppos) 2446 { 2447 struct inode * inode = file_inode(file); 2448 char *p = NULL; 2449 ssize_t length; 2450 struct task_struct *task = get_proc_task(inode); 2451 2452 if (!task) 2453 return -ESRCH; 2454 2455 length = security_getprocattr(task, 2456 (char*)file->f_path.dentry->d_name.name, 2457 &p); 2458 put_task_struct(task); 2459 if (length > 0) 2460 length = simple_read_from_buffer(buf, count, ppos, p, length); 2461 kfree(p); 2462 return length; 2463 } 2464 2465 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2466 size_t count, loff_t *ppos) 2467 { 2468 struct inode * inode = file_inode(file); 2469 void *page; 2470 ssize_t length; 2471 struct task_struct *task = get_proc_task(inode); 2472 2473 length = -ESRCH; 2474 if (!task) 2475 goto out_no_task; 2476 2477 /* A task may only write its own attributes. */ 2478 length = -EACCES; 2479 if (current != task) 2480 goto out; 2481 2482 if (count > PAGE_SIZE) 2483 count = PAGE_SIZE; 2484 2485 /* No partial writes. */ 2486 length = -EINVAL; 2487 if (*ppos != 0) 2488 goto out; 2489 2490 page = memdup_user(buf, count); 2491 if (IS_ERR(page)) { 2492 length = PTR_ERR(page); 2493 goto out; 2494 } 2495 2496 /* Guard against adverse ptrace interaction */ 2497 length = mutex_lock_interruptible(¤t->signal->cred_guard_mutex); 2498 if (length < 0) 2499 goto out_free; 2500 2501 length = security_setprocattr(file->f_path.dentry->d_name.name, 2502 page, count); 2503 mutex_unlock(¤t->signal->cred_guard_mutex); 2504 out_free: 2505 kfree(page); 2506 out: 2507 put_task_struct(task); 2508 out_no_task: 2509 return length; 2510 } 2511 2512 static const struct file_operations proc_pid_attr_operations = { 2513 .read = proc_pid_attr_read, 2514 .write = proc_pid_attr_write, 2515 .llseek = generic_file_llseek, 2516 }; 2517 2518 static const struct pid_entry attr_dir_stuff[] = { 2519 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2520 REG("prev", S_IRUGO, proc_pid_attr_operations), 2521 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2522 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2523 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2524 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2525 }; 2526 2527 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx) 2528 { 2529 return proc_pident_readdir(file, ctx, 2530 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2531 } 2532 2533 static const struct file_operations proc_attr_dir_operations = { 2534 .read = generic_read_dir, 2535 .iterate_shared = proc_attr_dir_readdir, 2536 .llseek = generic_file_llseek, 2537 }; 2538 2539 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2540 struct dentry *dentry, unsigned int flags) 2541 { 2542 return proc_pident_lookup(dir, dentry, 2543 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2544 } 2545 2546 static const struct inode_operations proc_attr_dir_inode_operations = { 2547 .lookup = proc_attr_dir_lookup, 2548 .getattr = pid_getattr, 2549 .setattr = proc_setattr, 2550 }; 2551 2552 #endif 2553 2554 #ifdef CONFIG_ELF_CORE 2555 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2556 size_t count, loff_t *ppos) 2557 { 2558 struct task_struct *task = get_proc_task(file_inode(file)); 2559 struct mm_struct *mm; 2560 char buffer[PROC_NUMBUF]; 2561 size_t len; 2562 int ret; 2563 2564 if (!task) 2565 return -ESRCH; 2566 2567 ret = 0; 2568 mm = get_task_mm(task); 2569 if (mm) { 2570 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2571 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2572 MMF_DUMP_FILTER_SHIFT)); 2573 mmput(mm); 2574 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2575 } 2576 2577 put_task_struct(task); 2578 2579 return ret; 2580 } 2581 2582 static ssize_t proc_coredump_filter_write(struct file *file, 2583 const char __user *buf, 2584 size_t count, 2585 loff_t *ppos) 2586 { 2587 struct task_struct *task; 2588 struct mm_struct *mm; 2589 unsigned int val; 2590 int ret; 2591 int i; 2592 unsigned long mask; 2593 2594 ret = kstrtouint_from_user(buf, count, 0, &val); 2595 if (ret < 0) 2596 return ret; 2597 2598 ret = -ESRCH; 2599 task = get_proc_task(file_inode(file)); 2600 if (!task) 2601 goto out_no_task; 2602 2603 mm = get_task_mm(task); 2604 if (!mm) 2605 goto out_no_mm; 2606 ret = 0; 2607 2608 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2609 if (val & mask) 2610 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2611 else 2612 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2613 } 2614 2615 mmput(mm); 2616 out_no_mm: 2617 put_task_struct(task); 2618 out_no_task: 2619 if (ret < 0) 2620 return ret; 2621 return count; 2622 } 2623 2624 static const struct file_operations proc_coredump_filter_operations = { 2625 .read = proc_coredump_filter_read, 2626 .write = proc_coredump_filter_write, 2627 .llseek = generic_file_llseek, 2628 }; 2629 #endif 2630 2631 #ifdef CONFIG_TASK_IO_ACCOUNTING 2632 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole) 2633 { 2634 struct task_io_accounting acct = task->ioac; 2635 unsigned long flags; 2636 int result; 2637 2638 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2639 if (result) 2640 return result; 2641 2642 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { 2643 result = -EACCES; 2644 goto out_unlock; 2645 } 2646 2647 if (whole && lock_task_sighand(task, &flags)) { 2648 struct task_struct *t = task; 2649 2650 task_io_accounting_add(&acct, &task->signal->ioac); 2651 while_each_thread(task, t) 2652 task_io_accounting_add(&acct, &t->ioac); 2653 2654 unlock_task_sighand(task, &flags); 2655 } 2656 seq_printf(m, 2657 "rchar: %llu\n" 2658 "wchar: %llu\n" 2659 "syscr: %llu\n" 2660 "syscw: %llu\n" 2661 "read_bytes: %llu\n" 2662 "write_bytes: %llu\n" 2663 "cancelled_write_bytes: %llu\n", 2664 (unsigned long long)acct.rchar, 2665 (unsigned long long)acct.wchar, 2666 (unsigned long long)acct.syscr, 2667 (unsigned long long)acct.syscw, 2668 (unsigned long long)acct.read_bytes, 2669 (unsigned long long)acct.write_bytes, 2670 (unsigned long long)acct.cancelled_write_bytes); 2671 result = 0; 2672 2673 out_unlock: 2674 mutex_unlock(&task->signal->cred_guard_mutex); 2675 return result; 2676 } 2677 2678 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2679 struct pid *pid, struct task_struct *task) 2680 { 2681 return do_io_accounting(task, m, 0); 2682 } 2683 2684 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2685 struct pid *pid, struct task_struct *task) 2686 { 2687 return do_io_accounting(task, m, 1); 2688 } 2689 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2690 2691 #ifdef CONFIG_USER_NS 2692 static int proc_id_map_open(struct inode *inode, struct file *file, 2693 const struct seq_operations *seq_ops) 2694 { 2695 struct user_namespace *ns = NULL; 2696 struct task_struct *task; 2697 struct seq_file *seq; 2698 int ret = -EINVAL; 2699 2700 task = get_proc_task(inode); 2701 if (task) { 2702 rcu_read_lock(); 2703 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2704 rcu_read_unlock(); 2705 put_task_struct(task); 2706 } 2707 if (!ns) 2708 goto err; 2709 2710 ret = seq_open(file, seq_ops); 2711 if (ret) 2712 goto err_put_ns; 2713 2714 seq = file->private_data; 2715 seq->private = ns; 2716 2717 return 0; 2718 err_put_ns: 2719 put_user_ns(ns); 2720 err: 2721 return ret; 2722 } 2723 2724 static int proc_id_map_release(struct inode *inode, struct file *file) 2725 { 2726 struct seq_file *seq = file->private_data; 2727 struct user_namespace *ns = seq->private; 2728 put_user_ns(ns); 2729 return seq_release(inode, file); 2730 } 2731 2732 static int proc_uid_map_open(struct inode *inode, struct file *file) 2733 { 2734 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2735 } 2736 2737 static int proc_gid_map_open(struct inode *inode, struct file *file) 2738 { 2739 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2740 } 2741 2742 static int proc_projid_map_open(struct inode *inode, struct file *file) 2743 { 2744 return proc_id_map_open(inode, file, &proc_projid_seq_operations); 2745 } 2746 2747 static const struct file_operations proc_uid_map_operations = { 2748 .open = proc_uid_map_open, 2749 .write = proc_uid_map_write, 2750 .read = seq_read, 2751 .llseek = seq_lseek, 2752 .release = proc_id_map_release, 2753 }; 2754 2755 static const struct file_operations proc_gid_map_operations = { 2756 .open = proc_gid_map_open, 2757 .write = proc_gid_map_write, 2758 .read = seq_read, 2759 .llseek = seq_lseek, 2760 .release = proc_id_map_release, 2761 }; 2762 2763 static const struct file_operations proc_projid_map_operations = { 2764 .open = proc_projid_map_open, 2765 .write = proc_projid_map_write, 2766 .read = seq_read, 2767 .llseek = seq_lseek, 2768 .release = proc_id_map_release, 2769 }; 2770 2771 static int proc_setgroups_open(struct inode *inode, struct file *file) 2772 { 2773 struct user_namespace *ns = NULL; 2774 struct task_struct *task; 2775 int ret; 2776 2777 ret = -ESRCH; 2778 task = get_proc_task(inode); 2779 if (task) { 2780 rcu_read_lock(); 2781 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2782 rcu_read_unlock(); 2783 put_task_struct(task); 2784 } 2785 if (!ns) 2786 goto err; 2787 2788 if (file->f_mode & FMODE_WRITE) { 2789 ret = -EACCES; 2790 if (!ns_capable(ns, CAP_SYS_ADMIN)) 2791 goto err_put_ns; 2792 } 2793 2794 ret = single_open(file, &proc_setgroups_show, ns); 2795 if (ret) 2796 goto err_put_ns; 2797 2798 return 0; 2799 err_put_ns: 2800 put_user_ns(ns); 2801 err: 2802 return ret; 2803 } 2804 2805 static int proc_setgroups_release(struct inode *inode, struct file *file) 2806 { 2807 struct seq_file *seq = file->private_data; 2808 struct user_namespace *ns = seq->private; 2809 int ret = single_release(inode, file); 2810 put_user_ns(ns); 2811 return ret; 2812 } 2813 2814 static const struct file_operations proc_setgroups_operations = { 2815 .open = proc_setgroups_open, 2816 .write = proc_setgroups_write, 2817 .read = seq_read, 2818 .llseek = seq_lseek, 2819 .release = proc_setgroups_release, 2820 }; 2821 #endif /* CONFIG_USER_NS */ 2822 2823 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2824 struct pid *pid, struct task_struct *task) 2825 { 2826 int err = lock_trace(task); 2827 if (!err) { 2828 seq_printf(m, "%08x\n", task->personality); 2829 unlock_trace(task); 2830 } 2831 return err; 2832 } 2833 2834 #ifdef CONFIG_LIVEPATCH 2835 static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns, 2836 struct pid *pid, struct task_struct *task) 2837 { 2838 seq_printf(m, "%d\n", task->patch_state); 2839 return 0; 2840 } 2841 #endif /* CONFIG_LIVEPATCH */ 2842 2843 /* 2844 * Thread groups 2845 */ 2846 static const struct file_operations proc_task_operations; 2847 static const struct inode_operations proc_task_inode_operations; 2848 2849 static const struct pid_entry tgid_base_stuff[] = { 2850 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2851 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2852 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 2853 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2854 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2855 #ifdef CONFIG_NET 2856 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2857 #endif 2858 REG("environ", S_IRUSR, proc_environ_operations), 2859 REG("auxv", S_IRUSR, proc_auxv_operations), 2860 ONE("status", S_IRUGO, proc_pid_status), 2861 ONE("personality", S_IRUSR, proc_pid_personality), 2862 ONE("limits", S_IRUGO, proc_pid_limits), 2863 #ifdef CONFIG_SCHED_DEBUG 2864 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2865 #endif 2866 #ifdef CONFIG_SCHED_AUTOGROUP 2867 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2868 #endif 2869 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2870 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2871 ONE("syscall", S_IRUSR, proc_pid_syscall), 2872 #endif 2873 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 2874 ONE("stat", S_IRUGO, proc_tgid_stat), 2875 ONE("statm", S_IRUGO, proc_pid_statm), 2876 REG("maps", S_IRUGO, proc_pid_maps_operations), 2877 #ifdef CONFIG_NUMA 2878 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 2879 #endif 2880 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2881 LNK("cwd", proc_cwd_link), 2882 LNK("root", proc_root_link), 2883 LNK("exe", proc_exe_link), 2884 REG("mounts", S_IRUGO, proc_mounts_operations), 2885 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2886 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2887 #ifdef CONFIG_PROC_PAGE_MONITOR 2888 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2889 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 2890 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2891 #endif 2892 #ifdef CONFIG_SECURITY 2893 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2894 #endif 2895 #ifdef CONFIG_KALLSYMS 2896 ONE("wchan", S_IRUGO, proc_pid_wchan), 2897 #endif 2898 #ifdef CONFIG_STACKTRACE 2899 ONE("stack", S_IRUSR, proc_pid_stack), 2900 #endif 2901 #ifdef CONFIG_SCHED_INFO 2902 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 2903 #endif 2904 #ifdef CONFIG_LATENCYTOP 2905 REG("latency", S_IRUGO, proc_lstats_operations), 2906 #endif 2907 #ifdef CONFIG_PROC_PID_CPUSET 2908 ONE("cpuset", S_IRUGO, proc_cpuset_show), 2909 #endif 2910 #ifdef CONFIG_CGROUPS 2911 ONE("cgroup", S_IRUGO, proc_cgroup_show), 2912 #endif 2913 ONE("oom_score", S_IRUGO, proc_oom_score), 2914 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 2915 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2916 #ifdef CONFIG_AUDITSYSCALL 2917 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2918 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2919 #endif 2920 #ifdef CONFIG_FAULT_INJECTION 2921 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2922 #endif 2923 #ifdef CONFIG_ELF_CORE 2924 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2925 #endif 2926 #ifdef CONFIG_TASK_IO_ACCOUNTING 2927 ONE("io", S_IRUSR, proc_tgid_io_accounting), 2928 #endif 2929 #ifdef CONFIG_HARDWALL 2930 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 2931 #endif 2932 #ifdef CONFIG_USER_NS 2933 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 2934 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 2935 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 2936 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 2937 #endif 2938 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS) 2939 REG("timers", S_IRUGO, proc_timers_operations), 2940 #endif 2941 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations), 2942 #ifdef CONFIG_LIVEPATCH 2943 ONE("patch_state", S_IRUSR, proc_pid_patch_state), 2944 #endif 2945 }; 2946 2947 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) 2948 { 2949 return proc_pident_readdir(file, ctx, 2950 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2951 } 2952 2953 static const struct file_operations proc_tgid_base_operations = { 2954 .read = generic_read_dir, 2955 .iterate_shared = proc_tgid_base_readdir, 2956 .llseek = generic_file_llseek, 2957 }; 2958 2959 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 2960 { 2961 return proc_pident_lookup(dir, dentry, 2962 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2963 } 2964 2965 static const struct inode_operations proc_tgid_base_inode_operations = { 2966 .lookup = proc_tgid_base_lookup, 2967 .getattr = pid_getattr, 2968 .setattr = proc_setattr, 2969 .permission = proc_pid_permission, 2970 }; 2971 2972 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2973 { 2974 struct dentry *dentry, *leader, *dir; 2975 char buf[PROC_NUMBUF]; 2976 struct qstr name; 2977 2978 name.name = buf; 2979 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2980 /* no ->d_hash() rejects on procfs */ 2981 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2982 if (dentry) { 2983 d_invalidate(dentry); 2984 dput(dentry); 2985 } 2986 2987 if (pid == tgid) 2988 return; 2989 2990 name.name = buf; 2991 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2992 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2993 if (!leader) 2994 goto out; 2995 2996 name.name = "task"; 2997 name.len = strlen(name.name); 2998 dir = d_hash_and_lookup(leader, &name); 2999 if (!dir) 3000 goto out_put_leader; 3001 3002 name.name = buf; 3003 name.len = snprintf(buf, sizeof(buf), "%d", pid); 3004 dentry = d_hash_and_lookup(dir, &name); 3005 if (dentry) { 3006 d_invalidate(dentry); 3007 dput(dentry); 3008 } 3009 3010 dput(dir); 3011 out_put_leader: 3012 dput(leader); 3013 out: 3014 return; 3015 } 3016 3017 /** 3018 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 3019 * @task: task that should be flushed. 3020 * 3021 * When flushing dentries from proc, one needs to flush them from global 3022 * proc (proc_mnt) and from all the namespaces' procs this task was seen 3023 * in. This call is supposed to do all of this job. 3024 * 3025 * Looks in the dcache for 3026 * /proc/@pid 3027 * /proc/@tgid/task/@pid 3028 * if either directory is present flushes it and all of it'ts children 3029 * from the dcache. 3030 * 3031 * It is safe and reasonable to cache /proc entries for a task until 3032 * that task exits. After that they just clog up the dcache with 3033 * useless entries, possibly causing useful dcache entries to be 3034 * flushed instead. This routine is proved to flush those useless 3035 * dcache entries at process exit time. 3036 * 3037 * NOTE: This routine is just an optimization so it does not guarantee 3038 * that no dcache entries will exist at process exit time it 3039 * just makes it very unlikely that any will persist. 3040 */ 3041 3042 void proc_flush_task(struct task_struct *task) 3043 { 3044 int i; 3045 struct pid *pid, *tgid; 3046 struct upid *upid; 3047 3048 pid = task_pid(task); 3049 tgid = task_tgid(task); 3050 3051 for (i = 0; i <= pid->level; i++) { 3052 upid = &pid->numbers[i]; 3053 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3054 tgid->numbers[i].nr); 3055 } 3056 } 3057 3058 static int proc_pid_instantiate(struct inode *dir, 3059 struct dentry * dentry, 3060 struct task_struct *task, const void *ptr) 3061 { 3062 struct inode *inode; 3063 3064 inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3065 if (!inode) 3066 goto out; 3067 3068 inode->i_op = &proc_tgid_base_inode_operations; 3069 inode->i_fop = &proc_tgid_base_operations; 3070 inode->i_flags|=S_IMMUTABLE; 3071 3072 set_nlink(inode, nlink_tgid); 3073 3074 d_set_d_op(dentry, &pid_dentry_operations); 3075 3076 d_add(dentry, inode); 3077 /* Close the race of the process dying before we return the dentry */ 3078 if (pid_revalidate(dentry, 0)) 3079 return 0; 3080 out: 3081 return -ENOENT; 3082 } 3083 3084 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3085 { 3086 int result = -ENOENT; 3087 struct task_struct *task; 3088 unsigned tgid; 3089 struct pid_namespace *ns; 3090 3091 tgid = name_to_int(&dentry->d_name); 3092 if (tgid == ~0U) 3093 goto out; 3094 3095 ns = dentry->d_sb->s_fs_info; 3096 rcu_read_lock(); 3097 task = find_task_by_pid_ns(tgid, ns); 3098 if (task) 3099 get_task_struct(task); 3100 rcu_read_unlock(); 3101 if (!task) 3102 goto out; 3103 3104 result = proc_pid_instantiate(dir, dentry, task, NULL); 3105 put_task_struct(task); 3106 out: 3107 return ERR_PTR(result); 3108 } 3109 3110 /* 3111 * Find the first task with tgid >= tgid 3112 * 3113 */ 3114 struct tgid_iter { 3115 unsigned int tgid; 3116 struct task_struct *task; 3117 }; 3118 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3119 { 3120 struct pid *pid; 3121 3122 if (iter.task) 3123 put_task_struct(iter.task); 3124 rcu_read_lock(); 3125 retry: 3126 iter.task = NULL; 3127 pid = find_ge_pid(iter.tgid, ns); 3128 if (pid) { 3129 iter.tgid = pid_nr_ns(pid, ns); 3130 iter.task = pid_task(pid, PIDTYPE_PID); 3131 /* What we to know is if the pid we have find is the 3132 * pid of a thread_group_leader. Testing for task 3133 * being a thread_group_leader is the obvious thing 3134 * todo but there is a window when it fails, due to 3135 * the pid transfer logic in de_thread. 3136 * 3137 * So we perform the straight forward test of seeing 3138 * if the pid we have found is the pid of a thread 3139 * group leader, and don't worry if the task we have 3140 * found doesn't happen to be a thread group leader. 3141 * As we don't care in the case of readdir. 3142 */ 3143 if (!iter.task || !has_group_leader_pid(iter.task)) { 3144 iter.tgid += 1; 3145 goto retry; 3146 } 3147 get_task_struct(iter.task); 3148 } 3149 rcu_read_unlock(); 3150 return iter; 3151 } 3152 3153 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2) 3154 3155 /* for the /proc/ directory itself, after non-process stuff has been done */ 3156 int proc_pid_readdir(struct file *file, struct dir_context *ctx) 3157 { 3158 struct tgid_iter iter; 3159 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info; 3160 loff_t pos = ctx->pos; 3161 3162 if (pos >= PID_MAX_LIMIT + TGID_OFFSET) 3163 return 0; 3164 3165 if (pos == TGID_OFFSET - 2) { 3166 struct inode *inode = d_inode(ns->proc_self); 3167 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) 3168 return 0; 3169 ctx->pos = pos = pos + 1; 3170 } 3171 if (pos == TGID_OFFSET - 1) { 3172 struct inode *inode = d_inode(ns->proc_thread_self); 3173 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) 3174 return 0; 3175 ctx->pos = pos = pos + 1; 3176 } 3177 iter.tgid = pos - TGID_OFFSET; 3178 iter.task = NULL; 3179 for (iter = next_tgid(ns, iter); 3180 iter.task; 3181 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3182 char name[PROC_NUMBUF]; 3183 int len; 3184 3185 cond_resched(); 3186 if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE)) 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 #ifdef CONFIG_LIVEPATCH 3328 ONE("patch_state", S_IRUSR, proc_pid_patch_state), 3329 #endif 3330 }; 3331 3332 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx) 3333 { 3334 return proc_pident_readdir(file, ctx, 3335 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3336 } 3337 3338 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3339 { 3340 return proc_pident_lookup(dir, dentry, 3341 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3342 } 3343 3344 static const struct file_operations proc_tid_base_operations = { 3345 .read = generic_read_dir, 3346 .iterate_shared = proc_tid_base_readdir, 3347 .llseek = generic_file_llseek, 3348 }; 3349 3350 static const struct inode_operations proc_tid_base_inode_operations = { 3351 .lookup = proc_tid_base_lookup, 3352 .getattr = pid_getattr, 3353 .setattr = proc_setattr, 3354 }; 3355 3356 static int proc_task_instantiate(struct inode *dir, 3357 struct dentry *dentry, struct task_struct *task, const void *ptr) 3358 { 3359 struct inode *inode; 3360 inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3361 3362 if (!inode) 3363 goto out; 3364 inode->i_op = &proc_tid_base_inode_operations; 3365 inode->i_fop = &proc_tid_base_operations; 3366 inode->i_flags|=S_IMMUTABLE; 3367 3368 set_nlink(inode, nlink_tid); 3369 3370 d_set_d_op(dentry, &pid_dentry_operations); 3371 3372 d_add(dentry, inode); 3373 /* Close the race of the process dying before we return the dentry */ 3374 if (pid_revalidate(dentry, 0)) 3375 return 0; 3376 out: 3377 return -ENOENT; 3378 } 3379 3380 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3381 { 3382 int result = -ENOENT; 3383 struct task_struct *task; 3384 struct task_struct *leader = get_proc_task(dir); 3385 unsigned tid; 3386 struct pid_namespace *ns; 3387 3388 if (!leader) 3389 goto out_no_task; 3390 3391 tid = name_to_int(&dentry->d_name); 3392 if (tid == ~0U) 3393 goto out; 3394 3395 ns = dentry->d_sb->s_fs_info; 3396 rcu_read_lock(); 3397 task = find_task_by_pid_ns(tid, ns); 3398 if (task) 3399 get_task_struct(task); 3400 rcu_read_unlock(); 3401 if (!task) 3402 goto out; 3403 if (!same_thread_group(leader, task)) 3404 goto out_drop_task; 3405 3406 result = proc_task_instantiate(dir, dentry, task, NULL); 3407 out_drop_task: 3408 put_task_struct(task); 3409 out: 3410 put_task_struct(leader); 3411 out_no_task: 3412 return ERR_PTR(result); 3413 } 3414 3415 /* 3416 * Find the first tid of a thread group to return to user space. 3417 * 3418 * Usually this is just the thread group leader, but if the users 3419 * buffer was too small or there was a seek into the middle of the 3420 * directory we have more work todo. 3421 * 3422 * In the case of a short read we start with find_task_by_pid. 3423 * 3424 * In the case of a seek we start with the leader and walk nr 3425 * threads past it. 3426 */ 3427 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos, 3428 struct pid_namespace *ns) 3429 { 3430 struct task_struct *pos, *task; 3431 unsigned long nr = f_pos; 3432 3433 if (nr != f_pos) /* 32bit overflow? */ 3434 return NULL; 3435 3436 rcu_read_lock(); 3437 task = pid_task(pid, PIDTYPE_PID); 3438 if (!task) 3439 goto fail; 3440 3441 /* Attempt to start with the tid of a thread */ 3442 if (tid && nr) { 3443 pos = find_task_by_pid_ns(tid, ns); 3444 if (pos && same_thread_group(pos, task)) 3445 goto found; 3446 } 3447 3448 /* If nr exceeds the number of threads there is nothing todo */ 3449 if (nr >= get_nr_threads(task)) 3450 goto fail; 3451 3452 /* If we haven't found our starting place yet start 3453 * with the leader and walk nr threads forward. 3454 */ 3455 pos = task = task->group_leader; 3456 do { 3457 if (!nr--) 3458 goto found; 3459 } while_each_thread(task, pos); 3460 fail: 3461 pos = NULL; 3462 goto out; 3463 found: 3464 get_task_struct(pos); 3465 out: 3466 rcu_read_unlock(); 3467 return pos; 3468 } 3469 3470 /* 3471 * Find the next thread in the thread list. 3472 * Return NULL if there is an error or no next thread. 3473 * 3474 * The reference to the input task_struct is released. 3475 */ 3476 static struct task_struct *next_tid(struct task_struct *start) 3477 { 3478 struct task_struct *pos = NULL; 3479 rcu_read_lock(); 3480 if (pid_alive(start)) { 3481 pos = next_thread(start); 3482 if (thread_group_leader(pos)) 3483 pos = NULL; 3484 else 3485 get_task_struct(pos); 3486 } 3487 rcu_read_unlock(); 3488 put_task_struct(start); 3489 return pos; 3490 } 3491 3492 /* for the /proc/TGID/task/ directories */ 3493 static int proc_task_readdir(struct file *file, struct dir_context *ctx) 3494 { 3495 struct inode *inode = file_inode(file); 3496 struct task_struct *task; 3497 struct pid_namespace *ns; 3498 int tid; 3499 3500 if (proc_inode_is_dead(inode)) 3501 return -ENOENT; 3502 3503 if (!dir_emit_dots(file, ctx)) 3504 return 0; 3505 3506 /* f_version caches the tgid value that the last readdir call couldn't 3507 * return. lseek aka telldir automagically resets f_version to 0. 3508 */ 3509 ns = inode->i_sb->s_fs_info; 3510 tid = (int)file->f_version; 3511 file->f_version = 0; 3512 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); 3513 task; 3514 task = next_tid(task), ctx->pos++) { 3515 char name[PROC_NUMBUF]; 3516 int len; 3517 tid = task_pid_nr_ns(task, ns); 3518 len = snprintf(name, sizeof(name), "%d", tid); 3519 if (!proc_fill_cache(file, ctx, name, len, 3520 proc_task_instantiate, task, NULL)) { 3521 /* returning this tgid failed, save it as the first 3522 * pid for the next readir call */ 3523 file->f_version = (u64)tid; 3524 put_task_struct(task); 3525 break; 3526 } 3527 } 3528 3529 return 0; 3530 } 3531 3532 static int proc_task_getattr(const struct path *path, struct kstat *stat, 3533 u32 request_mask, unsigned int query_flags) 3534 { 3535 struct inode *inode = d_inode(path->dentry); 3536 struct task_struct *p = get_proc_task(inode); 3537 generic_fillattr(inode, stat); 3538 3539 if (p) { 3540 stat->nlink += get_nr_threads(p); 3541 put_task_struct(p); 3542 } 3543 3544 return 0; 3545 } 3546 3547 static const struct inode_operations proc_task_inode_operations = { 3548 .lookup = proc_task_lookup, 3549 .getattr = proc_task_getattr, 3550 .setattr = proc_setattr, 3551 .permission = proc_pid_permission, 3552 }; 3553 3554 static const struct file_operations proc_task_operations = { 3555 .read = generic_read_dir, 3556 .iterate_shared = proc_task_readdir, 3557 .llseek = generic_file_llseek, 3558 }; 3559 3560 void __init set_proc_pid_nlink(void) 3561 { 3562 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3563 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3564 } 3565