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/flex_array.h> 92 #include <linux/posix-timers.h> 93 #ifdef CONFIG_HARDWALL 94 #include <asm/hardwall.h> 95 #endif 96 #include <trace/events/oom.h> 97 #include "internal.h" 98 #include "fd.h" 99 100 /* NOTE: 101 * Implementing inode permission operations in /proc is almost 102 * certainly an error. Permission checks need to happen during 103 * each system call not at open time. The reason is that most of 104 * what we wish to check for permissions in /proc varies at runtime. 105 * 106 * The classic example of a problem is opening file descriptors 107 * in /proc for a task before it execs a suid executable. 108 */ 109 110 static u8 nlink_tid; 111 static u8 nlink_tgid; 112 113 struct pid_entry { 114 const char *name; 115 unsigned int len; 116 umode_t mode; 117 const struct inode_operations *iop; 118 const struct file_operations *fop; 119 union proc_op op; 120 }; 121 122 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 123 .name = (NAME), \ 124 .len = sizeof(NAME) - 1, \ 125 .mode = MODE, \ 126 .iop = IOP, \ 127 .fop = FOP, \ 128 .op = OP, \ 129 } 130 131 #define DIR(NAME, MODE, iops, fops) \ 132 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} ) 133 #define LNK(NAME, get_link) \ 134 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 135 &proc_pid_link_inode_operations, NULL, \ 136 { .proc_get_link = get_link } ) 137 #define REG(NAME, MODE, fops) \ 138 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {}) 139 #define ONE(NAME, MODE, show) \ 140 NOD(NAME, (S_IFREG|(MODE)), \ 141 NULL, &proc_single_file_operations, \ 142 { .proc_show = show } ) 143 144 /* 145 * Count the number of hardlinks for the pid_entry table, excluding the . 146 * and .. links. 147 */ 148 static unsigned int __init pid_entry_nlink(const struct pid_entry *entries, 149 unsigned int n) 150 { 151 unsigned int i; 152 unsigned int count; 153 154 count = 2; 155 for (i = 0; i < n; ++i) { 156 if (S_ISDIR(entries[i].mode)) 157 ++count; 158 } 159 160 return count; 161 } 162 163 static int get_task_root(struct task_struct *task, struct path *root) 164 { 165 int result = -ENOENT; 166 167 task_lock(task); 168 if (task->fs) { 169 get_fs_root(task->fs, root); 170 result = 0; 171 } 172 task_unlock(task); 173 return result; 174 } 175 176 static int proc_cwd_link(struct dentry *dentry, struct path *path) 177 { 178 struct task_struct *task = get_proc_task(d_inode(dentry)); 179 int result = -ENOENT; 180 181 if (task) { 182 task_lock(task); 183 if (task->fs) { 184 get_fs_pwd(task->fs, path); 185 result = 0; 186 } 187 task_unlock(task); 188 put_task_struct(task); 189 } 190 return result; 191 } 192 193 static int proc_root_link(struct dentry *dentry, struct path *path) 194 { 195 struct task_struct *task = get_proc_task(d_inode(dentry)); 196 int result = -ENOENT; 197 198 if (task) { 199 result = get_task_root(task, path); 200 put_task_struct(task); 201 } 202 return result; 203 } 204 205 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, 206 size_t _count, loff_t *pos) 207 { 208 struct task_struct *tsk; 209 struct mm_struct *mm; 210 char *page; 211 unsigned long count = _count; 212 unsigned long arg_start, arg_end, env_start, env_end; 213 unsigned long len1, len2, len; 214 unsigned long p; 215 char c; 216 ssize_t rv; 217 218 BUG_ON(*pos < 0); 219 220 tsk = get_proc_task(file_inode(file)); 221 if (!tsk) 222 return -ESRCH; 223 mm = get_task_mm(tsk); 224 put_task_struct(tsk); 225 if (!mm) 226 return 0; 227 /* Check if process spawned far enough to have cmdline. */ 228 if (!mm->env_end) { 229 rv = 0; 230 goto out_mmput; 231 } 232 233 page = (char *)__get_free_page(GFP_TEMPORARY); 234 if (!page) { 235 rv = -ENOMEM; 236 goto out_mmput; 237 } 238 239 down_read(&mm->mmap_sem); 240 arg_start = mm->arg_start; 241 arg_end = mm->arg_end; 242 env_start = mm->env_start; 243 env_end = mm->env_end; 244 up_read(&mm->mmap_sem); 245 246 BUG_ON(arg_start > arg_end); 247 BUG_ON(env_start > env_end); 248 249 len1 = arg_end - arg_start; 250 len2 = env_end - env_start; 251 252 /* Empty ARGV. */ 253 if (len1 == 0) { 254 rv = 0; 255 goto out_free_page; 256 } 257 /* 258 * Inherently racy -- command line shares address space 259 * with code and data. 260 */ 261 rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0); 262 if (rv <= 0) 263 goto out_free_page; 264 265 rv = 0; 266 267 if (c == '\0') { 268 /* Command line (set of strings) occupies whole ARGV. */ 269 if (len1 <= *pos) 270 goto out_free_page; 271 272 p = arg_start + *pos; 273 len = len1 - *pos; 274 while (count > 0 && len > 0) { 275 unsigned int _count; 276 int nr_read; 277 278 _count = min3(count, len, PAGE_SIZE); 279 nr_read = access_remote_vm(mm, p, page, _count, 0); 280 if (nr_read < 0) 281 rv = nr_read; 282 if (nr_read <= 0) 283 goto out_free_page; 284 285 if (copy_to_user(buf, page, nr_read)) { 286 rv = -EFAULT; 287 goto out_free_page; 288 } 289 290 p += nr_read; 291 len -= nr_read; 292 buf += nr_read; 293 count -= nr_read; 294 rv += nr_read; 295 } 296 } else { 297 /* 298 * Command line (1 string) occupies ARGV and 299 * extends into ENVP. 300 */ 301 struct { 302 unsigned long p; 303 unsigned long len; 304 } cmdline[2] = { 305 { .p = arg_start, .len = len1 }, 306 { .p = env_start, .len = len2 }, 307 }; 308 loff_t pos1 = *pos; 309 unsigned int i; 310 311 i = 0; 312 while (i < 2 && pos1 >= cmdline[i].len) { 313 pos1 -= cmdline[i].len; 314 i++; 315 } 316 while (i < 2) { 317 p = cmdline[i].p + pos1; 318 len = cmdline[i].len - pos1; 319 while (count > 0 && len > 0) { 320 unsigned int _count, l; 321 int nr_read; 322 bool final; 323 324 _count = min3(count, len, PAGE_SIZE); 325 nr_read = access_remote_vm(mm, p, page, _count, 0); 326 if (nr_read < 0) 327 rv = nr_read; 328 if (nr_read <= 0) 329 goto out_free_page; 330 331 /* 332 * Command line can be shorter than whole ARGV 333 * even if last "marker" byte says it is not. 334 */ 335 final = false; 336 l = strnlen(page, nr_read); 337 if (l < nr_read) { 338 nr_read = l; 339 final = true; 340 } 341 342 if (copy_to_user(buf, page, nr_read)) { 343 rv = -EFAULT; 344 goto out_free_page; 345 } 346 347 p += nr_read; 348 len -= nr_read; 349 buf += nr_read; 350 count -= nr_read; 351 rv += nr_read; 352 353 if (final) 354 goto out_free_page; 355 } 356 357 /* Only first chunk can be read partially. */ 358 pos1 = 0; 359 i++; 360 } 361 } 362 363 out_free_page: 364 free_page((unsigned long)page); 365 out_mmput: 366 mmput(mm); 367 if (rv > 0) 368 *pos += rv; 369 return rv; 370 } 371 372 static const struct file_operations proc_pid_cmdline_ops = { 373 .read = proc_pid_cmdline_read, 374 .llseek = generic_file_llseek, 375 }; 376 377 #ifdef CONFIG_KALLSYMS 378 /* 379 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 380 * Returns the resolved symbol. If that fails, simply return the address. 381 */ 382 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns, 383 struct pid *pid, struct task_struct *task) 384 { 385 unsigned long wchan; 386 char symname[KSYM_NAME_LEN]; 387 388 wchan = get_wchan(task); 389 390 if (wchan && ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS) 391 && !lookup_symbol_name(wchan, symname)) 392 seq_printf(m, "%s", symname); 393 else 394 seq_putc(m, '0'); 395 396 return 0; 397 } 398 #endif /* CONFIG_KALLSYMS */ 399 400 static int lock_trace(struct task_struct *task) 401 { 402 int err = mutex_lock_killable(&task->signal->cred_guard_mutex); 403 if (err) 404 return err; 405 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) { 406 mutex_unlock(&task->signal->cred_guard_mutex); 407 return -EPERM; 408 } 409 return 0; 410 } 411 412 static void unlock_trace(struct task_struct *task) 413 { 414 mutex_unlock(&task->signal->cred_guard_mutex); 415 } 416 417 #ifdef CONFIG_STACKTRACE 418 419 #define MAX_STACK_TRACE_DEPTH 64 420 421 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, 422 struct pid *pid, struct task_struct *task) 423 { 424 struct stack_trace trace; 425 unsigned long *entries; 426 int err; 427 int i; 428 429 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL); 430 if (!entries) 431 return -ENOMEM; 432 433 trace.nr_entries = 0; 434 trace.max_entries = MAX_STACK_TRACE_DEPTH; 435 trace.entries = entries; 436 trace.skip = 0; 437 438 err = lock_trace(task); 439 if (!err) { 440 save_stack_trace_tsk(task, &trace); 441 442 for (i = 0; i < trace.nr_entries; i++) { 443 seq_printf(m, "[<%pK>] %pB\n", 444 (void *)entries[i], (void *)entries[i]); 445 } 446 unlock_trace(task); 447 } 448 kfree(entries); 449 450 return err; 451 } 452 #endif 453 454 #ifdef CONFIG_SCHED_INFO 455 /* 456 * Provides /proc/PID/schedstat 457 */ 458 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, 459 struct pid *pid, struct task_struct *task) 460 { 461 if (unlikely(!sched_info_on())) 462 seq_printf(m, "0 0 0\n"); 463 else 464 seq_printf(m, "%llu %llu %lu\n", 465 (unsigned long long)task->se.sum_exec_runtime, 466 (unsigned long long)task->sched_info.run_delay, 467 task->sched_info.pcount); 468 469 return 0; 470 } 471 #endif 472 473 #ifdef CONFIG_LATENCYTOP 474 static int lstats_show_proc(struct seq_file *m, void *v) 475 { 476 int i; 477 struct inode *inode = m->private; 478 struct task_struct *task = get_proc_task(inode); 479 480 if (!task) 481 return -ESRCH; 482 seq_puts(m, "Latency Top version : v0.1\n"); 483 for (i = 0; i < 32; i++) { 484 struct latency_record *lr = &task->latency_record[i]; 485 if (lr->backtrace[0]) { 486 int q; 487 seq_printf(m, "%i %li %li", 488 lr->count, lr->time, lr->max); 489 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 490 unsigned long bt = lr->backtrace[q]; 491 if (!bt) 492 break; 493 if (bt == ULONG_MAX) 494 break; 495 seq_printf(m, " %ps", (void *)bt); 496 } 497 seq_putc(m, '\n'); 498 } 499 500 } 501 put_task_struct(task); 502 return 0; 503 } 504 505 static int lstats_open(struct inode *inode, struct file *file) 506 { 507 return single_open(file, lstats_show_proc, inode); 508 } 509 510 static ssize_t lstats_write(struct file *file, const char __user *buf, 511 size_t count, loff_t *offs) 512 { 513 struct task_struct *task = get_proc_task(file_inode(file)); 514 515 if (!task) 516 return -ESRCH; 517 clear_all_latency_tracing(task); 518 put_task_struct(task); 519 520 return count; 521 } 522 523 static const struct file_operations proc_lstats_operations = { 524 .open = lstats_open, 525 .read = seq_read, 526 .write = lstats_write, 527 .llseek = seq_lseek, 528 .release = single_release, 529 }; 530 531 #endif 532 533 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns, 534 struct pid *pid, struct task_struct *task) 535 { 536 unsigned long totalpages = totalram_pages + total_swap_pages; 537 unsigned long points = 0; 538 539 points = oom_badness(task, NULL, NULL, totalpages) * 540 1000 / totalpages; 541 seq_printf(m, "%lu\n", points); 542 543 return 0; 544 } 545 546 struct limit_names { 547 const char *name; 548 const char *unit; 549 }; 550 551 static const struct limit_names lnames[RLIM_NLIMITS] = { 552 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 553 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 554 [RLIMIT_DATA] = {"Max data size", "bytes"}, 555 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 556 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 557 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 558 [RLIMIT_NPROC] = {"Max processes", "processes"}, 559 [RLIMIT_NOFILE] = {"Max open files", "files"}, 560 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 561 [RLIMIT_AS] = {"Max address space", "bytes"}, 562 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 563 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 564 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 565 [RLIMIT_NICE] = {"Max nice priority", NULL}, 566 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 567 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 568 }; 569 570 /* Display limits for a process */ 571 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns, 572 struct pid *pid, struct task_struct *task) 573 { 574 unsigned int i; 575 unsigned long flags; 576 577 struct rlimit rlim[RLIM_NLIMITS]; 578 579 if (!lock_task_sighand(task, &flags)) 580 return 0; 581 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 582 unlock_task_sighand(task, &flags); 583 584 /* 585 * print the file header 586 */ 587 seq_printf(m, "%-25s %-20s %-20s %-10s\n", 588 "Limit", "Soft Limit", "Hard Limit", "Units"); 589 590 for (i = 0; i < RLIM_NLIMITS; i++) { 591 if (rlim[i].rlim_cur == RLIM_INFINITY) 592 seq_printf(m, "%-25s %-20s ", 593 lnames[i].name, "unlimited"); 594 else 595 seq_printf(m, "%-25s %-20lu ", 596 lnames[i].name, rlim[i].rlim_cur); 597 598 if (rlim[i].rlim_max == RLIM_INFINITY) 599 seq_printf(m, "%-20s ", "unlimited"); 600 else 601 seq_printf(m, "%-20lu ", rlim[i].rlim_max); 602 603 if (lnames[i].unit) 604 seq_printf(m, "%-10s\n", lnames[i].unit); 605 else 606 seq_putc(m, '\n'); 607 } 608 609 return 0; 610 } 611 612 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 613 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns, 614 struct pid *pid, struct task_struct *task) 615 { 616 long nr; 617 unsigned long args[6], sp, pc; 618 int res; 619 620 res = lock_trace(task); 621 if (res) 622 return res; 623 624 if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) 625 seq_puts(m, "running\n"); 626 else if (nr < 0) 627 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc); 628 else 629 seq_printf(m, 630 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", 631 nr, 632 args[0], args[1], args[2], args[3], args[4], args[5], 633 sp, pc); 634 unlock_trace(task); 635 636 return 0; 637 } 638 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 639 640 /************************************************************************/ 641 /* Here the fs part begins */ 642 /************************************************************************/ 643 644 /* permission checks */ 645 static int proc_fd_access_allowed(struct inode *inode) 646 { 647 struct task_struct *task; 648 int allowed = 0; 649 /* Allow access to a task's file descriptors if it is us or we 650 * may use ptrace attach to the process and find out that 651 * information. 652 */ 653 task = get_proc_task(inode); 654 if (task) { 655 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 656 put_task_struct(task); 657 } 658 return allowed; 659 } 660 661 int proc_setattr(struct dentry *dentry, struct iattr *attr) 662 { 663 int error; 664 struct inode *inode = d_inode(dentry); 665 666 if (attr->ia_valid & ATTR_MODE) 667 return -EPERM; 668 669 error = setattr_prepare(dentry, attr); 670 if (error) 671 return error; 672 673 setattr_copy(inode, attr); 674 mark_inode_dirty(inode); 675 return 0; 676 } 677 678 /* 679 * May current process learn task's sched/cmdline info (for hide_pid_min=1) 680 * or euid/egid (for hide_pid_min=2)? 681 */ 682 static bool has_pid_permissions(struct pid_namespace *pid, 683 struct task_struct *task, 684 int hide_pid_min) 685 { 686 if (pid->hide_pid < hide_pid_min) 687 return true; 688 if (in_group_p(pid->pid_gid)) 689 return true; 690 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 691 } 692 693 694 static int proc_pid_permission(struct inode *inode, int mask) 695 { 696 struct pid_namespace *pid = inode->i_sb->s_fs_info; 697 struct task_struct *task; 698 bool has_perms; 699 700 task = get_proc_task(inode); 701 if (!task) 702 return -ESRCH; 703 has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS); 704 put_task_struct(task); 705 706 if (!has_perms) { 707 if (pid->hide_pid == HIDEPID_INVISIBLE) { 708 /* 709 * Let's make getdents(), stat(), and open() 710 * consistent with each other. If a process 711 * may not stat() a file, it shouldn't be seen 712 * in procfs at all. 713 */ 714 return -ENOENT; 715 } 716 717 return -EPERM; 718 } 719 return generic_permission(inode, mask); 720 } 721 722 723 724 static const struct inode_operations proc_def_inode_operations = { 725 .setattr = proc_setattr, 726 }; 727 728 static int proc_single_show(struct seq_file *m, void *v) 729 { 730 struct inode *inode = m->private; 731 struct pid_namespace *ns; 732 struct pid *pid; 733 struct task_struct *task; 734 int ret; 735 736 ns = inode->i_sb->s_fs_info; 737 pid = proc_pid(inode); 738 task = get_pid_task(pid, PIDTYPE_PID); 739 if (!task) 740 return -ESRCH; 741 742 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 743 744 put_task_struct(task); 745 return ret; 746 } 747 748 static int proc_single_open(struct inode *inode, struct file *filp) 749 { 750 return single_open(filp, proc_single_show, inode); 751 } 752 753 static const struct file_operations proc_single_file_operations = { 754 .open = proc_single_open, 755 .read = seq_read, 756 .llseek = seq_lseek, 757 .release = single_release, 758 }; 759 760 761 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode) 762 { 763 struct task_struct *task = get_proc_task(inode); 764 struct mm_struct *mm = ERR_PTR(-ESRCH); 765 766 if (task) { 767 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS); 768 put_task_struct(task); 769 770 if (!IS_ERR_OR_NULL(mm)) { 771 /* ensure this mm_struct can't be freed */ 772 mmgrab(mm); 773 /* but do not pin its memory */ 774 mmput(mm); 775 } 776 } 777 778 return mm; 779 } 780 781 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) 782 { 783 struct mm_struct *mm = proc_mem_open(inode, mode); 784 785 if (IS_ERR(mm)) 786 return PTR_ERR(mm); 787 788 file->private_data = mm; 789 return 0; 790 } 791 792 static int mem_open(struct inode *inode, struct file *file) 793 { 794 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH); 795 796 /* OK to pass negative loff_t, we can catch out-of-range */ 797 file->f_mode |= FMODE_UNSIGNED_OFFSET; 798 799 return ret; 800 } 801 802 static ssize_t mem_rw(struct file *file, char __user *buf, 803 size_t count, loff_t *ppos, int write) 804 { 805 struct mm_struct *mm = file->private_data; 806 unsigned long addr = *ppos; 807 ssize_t copied; 808 char *page; 809 unsigned int flags; 810 811 if (!mm) 812 return 0; 813 814 page = (char *)__get_free_page(GFP_TEMPORARY); 815 if (!page) 816 return -ENOMEM; 817 818 copied = 0; 819 if (!mmget_not_zero(mm)) 820 goto free; 821 822 /* Maybe we should limit FOLL_FORCE to actual ptrace users? */ 823 flags = FOLL_FORCE; 824 if (write) 825 flags |= FOLL_WRITE; 826 827 while (count > 0) { 828 int this_len = min_t(int, count, PAGE_SIZE); 829 830 if (write && copy_from_user(page, buf, this_len)) { 831 copied = -EFAULT; 832 break; 833 } 834 835 this_len = access_remote_vm(mm, addr, page, this_len, flags); 836 if (!this_len) { 837 if (!copied) 838 copied = -EIO; 839 break; 840 } 841 842 if (!write && copy_to_user(buf, page, this_len)) { 843 copied = -EFAULT; 844 break; 845 } 846 847 buf += this_len; 848 addr += this_len; 849 copied += this_len; 850 count -= this_len; 851 } 852 *ppos = addr; 853 854 mmput(mm); 855 free: 856 free_page((unsigned long) page); 857 return copied; 858 } 859 860 static ssize_t mem_read(struct file *file, char __user *buf, 861 size_t count, loff_t *ppos) 862 { 863 return mem_rw(file, buf, count, ppos, 0); 864 } 865 866 static ssize_t mem_write(struct file *file, const char __user *buf, 867 size_t count, loff_t *ppos) 868 { 869 return mem_rw(file, (char __user*)buf, count, ppos, 1); 870 } 871 872 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 873 { 874 switch (orig) { 875 case 0: 876 file->f_pos = offset; 877 break; 878 case 1: 879 file->f_pos += offset; 880 break; 881 default: 882 return -EINVAL; 883 } 884 force_successful_syscall_return(); 885 return file->f_pos; 886 } 887 888 static int mem_release(struct inode *inode, struct file *file) 889 { 890 struct mm_struct *mm = file->private_data; 891 if (mm) 892 mmdrop(mm); 893 return 0; 894 } 895 896 static const struct file_operations proc_mem_operations = { 897 .llseek = mem_lseek, 898 .read = mem_read, 899 .write = mem_write, 900 .open = mem_open, 901 .release = mem_release, 902 }; 903 904 static int environ_open(struct inode *inode, struct file *file) 905 { 906 return __mem_open(inode, file, PTRACE_MODE_READ); 907 } 908 909 static ssize_t environ_read(struct file *file, char __user *buf, 910 size_t count, loff_t *ppos) 911 { 912 char *page; 913 unsigned long src = *ppos; 914 int ret = 0; 915 struct mm_struct *mm = file->private_data; 916 unsigned long env_start, env_end; 917 918 /* Ensure the process spawned far enough to have an environment. */ 919 if (!mm || !mm->env_end) 920 return 0; 921 922 page = (char *)__get_free_page(GFP_TEMPORARY); 923 if (!page) 924 return -ENOMEM; 925 926 ret = 0; 927 if (!mmget_not_zero(mm)) 928 goto free; 929 930 down_read(&mm->mmap_sem); 931 env_start = mm->env_start; 932 env_end = mm->env_end; 933 up_read(&mm->mmap_sem); 934 935 while (count > 0) { 936 size_t this_len, max_len; 937 int retval; 938 939 if (src >= (env_end - env_start)) 940 break; 941 942 this_len = env_end - (env_start + src); 943 944 max_len = min_t(size_t, PAGE_SIZE, count); 945 this_len = min(max_len, this_len); 946 947 retval = access_remote_vm(mm, (env_start + src), page, this_len, 0); 948 949 if (retval <= 0) { 950 ret = retval; 951 break; 952 } 953 954 if (copy_to_user(buf, page, retval)) { 955 ret = -EFAULT; 956 break; 957 } 958 959 ret += retval; 960 src += retval; 961 buf += retval; 962 count -= retval; 963 } 964 *ppos = src; 965 mmput(mm); 966 967 free: 968 free_page((unsigned long) page); 969 return ret; 970 } 971 972 static const struct file_operations proc_environ_operations = { 973 .open = environ_open, 974 .read = environ_read, 975 .llseek = generic_file_llseek, 976 .release = mem_release, 977 }; 978 979 static int auxv_open(struct inode *inode, struct file *file) 980 { 981 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS); 982 } 983 984 static ssize_t auxv_read(struct file *file, char __user *buf, 985 size_t count, loff_t *ppos) 986 { 987 struct mm_struct *mm = file->private_data; 988 unsigned int nwords = 0; 989 990 if (!mm) 991 return 0; 992 do { 993 nwords += 2; 994 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 995 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv, 996 nwords * sizeof(mm->saved_auxv[0])); 997 } 998 999 static const struct file_operations proc_auxv_operations = { 1000 .open = auxv_open, 1001 .read = auxv_read, 1002 .llseek = generic_file_llseek, 1003 .release = mem_release, 1004 }; 1005 1006 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count, 1007 loff_t *ppos) 1008 { 1009 struct task_struct *task = get_proc_task(file_inode(file)); 1010 char buffer[PROC_NUMBUF]; 1011 int oom_adj = OOM_ADJUST_MIN; 1012 size_t len; 1013 1014 if (!task) 1015 return -ESRCH; 1016 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX) 1017 oom_adj = OOM_ADJUST_MAX; 1018 else 1019 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) / 1020 OOM_SCORE_ADJ_MAX; 1021 put_task_struct(task); 1022 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj); 1023 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1024 } 1025 1026 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy) 1027 { 1028 static DEFINE_MUTEX(oom_adj_mutex); 1029 struct mm_struct *mm = NULL; 1030 struct task_struct *task; 1031 int err = 0; 1032 1033 task = get_proc_task(file_inode(file)); 1034 if (!task) 1035 return -ESRCH; 1036 1037 mutex_lock(&oom_adj_mutex); 1038 if (legacy) { 1039 if (oom_adj < task->signal->oom_score_adj && 1040 !capable(CAP_SYS_RESOURCE)) { 1041 err = -EACCES; 1042 goto err_unlock; 1043 } 1044 /* 1045 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use 1046 * /proc/pid/oom_score_adj instead. 1047 */ 1048 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 1049 current->comm, task_pid_nr(current), task_pid_nr(task), 1050 task_pid_nr(task)); 1051 } else { 1052 if ((short)oom_adj < task->signal->oom_score_adj_min && 1053 !capable(CAP_SYS_RESOURCE)) { 1054 err = -EACCES; 1055 goto err_unlock; 1056 } 1057 } 1058 1059 /* 1060 * Make sure we will check other processes sharing the mm if this is 1061 * not vfrok which wants its own oom_score_adj. 1062 * pin the mm so it doesn't go away and get reused after task_unlock 1063 */ 1064 if (!task->vfork_done) { 1065 struct task_struct *p = find_lock_task_mm(task); 1066 1067 if (p) { 1068 if (atomic_read(&p->mm->mm_users) > 1) { 1069 mm = p->mm; 1070 mmgrab(mm); 1071 } 1072 task_unlock(p); 1073 } 1074 } 1075 1076 task->signal->oom_score_adj = oom_adj; 1077 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1078 task->signal->oom_score_adj_min = (short)oom_adj; 1079 trace_oom_score_adj_update(task); 1080 1081 if (mm) { 1082 struct task_struct *p; 1083 1084 rcu_read_lock(); 1085 for_each_process(p) { 1086 if (same_thread_group(task, p)) 1087 continue; 1088 1089 /* do not touch kernel threads or the global init */ 1090 if (p->flags & PF_KTHREAD || is_global_init(p)) 1091 continue; 1092 1093 task_lock(p); 1094 if (!p->vfork_done && process_shares_mm(p, mm)) { 1095 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", 1096 task_pid_nr(p), p->comm, 1097 p->signal->oom_score_adj, oom_adj, 1098 task_pid_nr(task), task->comm); 1099 p->signal->oom_score_adj = oom_adj; 1100 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1101 p->signal->oom_score_adj_min = (short)oom_adj; 1102 } 1103 task_unlock(p); 1104 } 1105 rcu_read_unlock(); 1106 mmdrop(mm); 1107 } 1108 err_unlock: 1109 mutex_unlock(&oom_adj_mutex); 1110 put_task_struct(task); 1111 return err; 1112 } 1113 1114 /* 1115 * /proc/pid/oom_adj exists solely for backwards compatibility with previous 1116 * kernels. The effective policy is defined by oom_score_adj, which has a 1117 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly. 1118 * Values written to oom_adj are simply mapped linearly to oom_score_adj. 1119 * Processes that become oom disabled via oom_adj will still be oom disabled 1120 * with this implementation. 1121 * 1122 * oom_adj cannot be removed since existing userspace binaries use it. 1123 */ 1124 static ssize_t oom_adj_write(struct file *file, const char __user *buf, 1125 size_t count, loff_t *ppos) 1126 { 1127 char buffer[PROC_NUMBUF]; 1128 int oom_adj; 1129 int err; 1130 1131 memset(buffer, 0, sizeof(buffer)); 1132 if (count > sizeof(buffer) - 1) 1133 count = sizeof(buffer) - 1; 1134 if (copy_from_user(buffer, buf, count)) { 1135 err = -EFAULT; 1136 goto out; 1137 } 1138 1139 err = kstrtoint(strstrip(buffer), 0, &oom_adj); 1140 if (err) 1141 goto out; 1142 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) && 1143 oom_adj != OOM_DISABLE) { 1144 err = -EINVAL; 1145 goto out; 1146 } 1147 1148 /* 1149 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 1150 * value is always attainable. 1151 */ 1152 if (oom_adj == OOM_ADJUST_MAX) 1153 oom_adj = OOM_SCORE_ADJ_MAX; 1154 else 1155 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE; 1156 1157 err = __set_oom_adj(file, oom_adj, true); 1158 out: 1159 return err < 0 ? err : count; 1160 } 1161 1162 static const struct file_operations proc_oom_adj_operations = { 1163 .read = oom_adj_read, 1164 .write = oom_adj_write, 1165 .llseek = generic_file_llseek, 1166 }; 1167 1168 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 1169 size_t count, loff_t *ppos) 1170 { 1171 struct task_struct *task = get_proc_task(file_inode(file)); 1172 char buffer[PROC_NUMBUF]; 1173 short oom_score_adj = OOM_SCORE_ADJ_MIN; 1174 size_t len; 1175 1176 if (!task) 1177 return -ESRCH; 1178 oom_score_adj = task->signal->oom_score_adj; 1179 put_task_struct(task); 1180 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj); 1181 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1182 } 1183 1184 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1185 size_t count, loff_t *ppos) 1186 { 1187 char buffer[PROC_NUMBUF]; 1188 int oom_score_adj; 1189 int err; 1190 1191 memset(buffer, 0, sizeof(buffer)); 1192 if (count > sizeof(buffer) - 1) 1193 count = sizeof(buffer) - 1; 1194 if (copy_from_user(buffer, buf, count)) { 1195 err = -EFAULT; 1196 goto out; 1197 } 1198 1199 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 1200 if (err) 1201 goto out; 1202 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1203 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1204 err = -EINVAL; 1205 goto out; 1206 } 1207 1208 err = __set_oom_adj(file, oom_score_adj, false); 1209 out: 1210 return err < 0 ? err : count; 1211 } 1212 1213 static const struct file_operations proc_oom_score_adj_operations = { 1214 .read = oom_score_adj_read, 1215 .write = oom_score_adj_write, 1216 .llseek = default_llseek, 1217 }; 1218 1219 #ifdef CONFIG_AUDITSYSCALL 1220 #define TMPBUFLEN 11 1221 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1222 size_t count, loff_t *ppos) 1223 { 1224 struct inode * inode = file_inode(file); 1225 struct task_struct *task = get_proc_task(inode); 1226 ssize_t length; 1227 char tmpbuf[TMPBUFLEN]; 1228 1229 if (!task) 1230 return -ESRCH; 1231 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1232 from_kuid(file->f_cred->user_ns, 1233 audit_get_loginuid(task))); 1234 put_task_struct(task); 1235 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1236 } 1237 1238 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1239 size_t count, loff_t *ppos) 1240 { 1241 struct inode * inode = file_inode(file); 1242 uid_t loginuid; 1243 kuid_t kloginuid; 1244 int rv; 1245 1246 rcu_read_lock(); 1247 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1248 rcu_read_unlock(); 1249 return -EPERM; 1250 } 1251 rcu_read_unlock(); 1252 1253 if (*ppos != 0) { 1254 /* No partial writes. */ 1255 return -EINVAL; 1256 } 1257 1258 rv = kstrtou32_from_user(buf, count, 10, &loginuid); 1259 if (rv < 0) 1260 return rv; 1261 1262 /* is userspace tring to explicitly UNSET the loginuid? */ 1263 if (loginuid == AUDIT_UID_UNSET) { 1264 kloginuid = INVALID_UID; 1265 } else { 1266 kloginuid = make_kuid(file->f_cred->user_ns, loginuid); 1267 if (!uid_valid(kloginuid)) 1268 return -EINVAL; 1269 } 1270 1271 rv = audit_set_loginuid(kloginuid); 1272 if (rv < 0) 1273 return rv; 1274 return count; 1275 } 1276 1277 static const struct file_operations proc_loginuid_operations = { 1278 .read = proc_loginuid_read, 1279 .write = proc_loginuid_write, 1280 .llseek = generic_file_llseek, 1281 }; 1282 1283 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1284 size_t count, loff_t *ppos) 1285 { 1286 struct inode * inode = file_inode(file); 1287 struct task_struct *task = get_proc_task(inode); 1288 ssize_t length; 1289 char tmpbuf[TMPBUFLEN]; 1290 1291 if (!task) 1292 return -ESRCH; 1293 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1294 audit_get_sessionid(task)); 1295 put_task_struct(task); 1296 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1297 } 1298 1299 static const struct file_operations proc_sessionid_operations = { 1300 .read = proc_sessionid_read, 1301 .llseek = generic_file_llseek, 1302 }; 1303 #endif 1304 1305 #ifdef CONFIG_FAULT_INJECTION 1306 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1307 size_t count, loff_t *ppos) 1308 { 1309 struct task_struct *task = get_proc_task(file_inode(file)); 1310 char buffer[PROC_NUMBUF]; 1311 size_t len; 1312 int make_it_fail; 1313 1314 if (!task) 1315 return -ESRCH; 1316 make_it_fail = task->make_it_fail; 1317 put_task_struct(task); 1318 1319 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1320 1321 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1322 } 1323 1324 static ssize_t proc_fault_inject_write(struct file * file, 1325 const char __user * buf, size_t count, loff_t *ppos) 1326 { 1327 struct task_struct *task; 1328 char buffer[PROC_NUMBUF]; 1329 int make_it_fail; 1330 int rv; 1331 1332 if (!capable(CAP_SYS_RESOURCE)) 1333 return -EPERM; 1334 memset(buffer, 0, sizeof(buffer)); 1335 if (count > sizeof(buffer) - 1) 1336 count = sizeof(buffer) - 1; 1337 if (copy_from_user(buffer, buf, count)) 1338 return -EFAULT; 1339 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail); 1340 if (rv < 0) 1341 return rv; 1342 if (make_it_fail < 0 || make_it_fail > 1) 1343 return -EINVAL; 1344 1345 task = get_proc_task(file_inode(file)); 1346 if (!task) 1347 return -ESRCH; 1348 task->make_it_fail = make_it_fail; 1349 put_task_struct(task); 1350 1351 return count; 1352 } 1353 1354 static const struct file_operations proc_fault_inject_operations = { 1355 .read = proc_fault_inject_read, 1356 .write = proc_fault_inject_write, 1357 .llseek = generic_file_llseek, 1358 }; 1359 #endif 1360 1361 1362 #ifdef CONFIG_SCHED_DEBUG 1363 /* 1364 * Print out various scheduling related per-task fields: 1365 */ 1366 static int sched_show(struct seq_file *m, void *v) 1367 { 1368 struct inode *inode = m->private; 1369 struct task_struct *p; 1370 1371 p = get_proc_task(inode); 1372 if (!p) 1373 return -ESRCH; 1374 proc_sched_show_task(p, m); 1375 1376 put_task_struct(p); 1377 1378 return 0; 1379 } 1380 1381 static ssize_t 1382 sched_write(struct file *file, const char __user *buf, 1383 size_t count, loff_t *offset) 1384 { 1385 struct inode *inode = file_inode(file); 1386 struct task_struct *p; 1387 1388 p = get_proc_task(inode); 1389 if (!p) 1390 return -ESRCH; 1391 proc_sched_set_task(p); 1392 1393 put_task_struct(p); 1394 1395 return count; 1396 } 1397 1398 static int sched_open(struct inode *inode, struct file *filp) 1399 { 1400 return single_open(filp, sched_show, inode); 1401 } 1402 1403 static const struct file_operations proc_pid_sched_operations = { 1404 .open = sched_open, 1405 .read = seq_read, 1406 .write = sched_write, 1407 .llseek = seq_lseek, 1408 .release = single_release, 1409 }; 1410 1411 #endif 1412 1413 #ifdef CONFIG_SCHED_AUTOGROUP 1414 /* 1415 * Print out autogroup related information: 1416 */ 1417 static int sched_autogroup_show(struct seq_file *m, void *v) 1418 { 1419 struct inode *inode = m->private; 1420 struct task_struct *p; 1421 1422 p = get_proc_task(inode); 1423 if (!p) 1424 return -ESRCH; 1425 proc_sched_autogroup_show_task(p, m); 1426 1427 put_task_struct(p); 1428 1429 return 0; 1430 } 1431 1432 static ssize_t 1433 sched_autogroup_write(struct file *file, const char __user *buf, 1434 size_t count, loff_t *offset) 1435 { 1436 struct inode *inode = file_inode(file); 1437 struct task_struct *p; 1438 char buffer[PROC_NUMBUF]; 1439 int nice; 1440 int err; 1441 1442 memset(buffer, 0, sizeof(buffer)); 1443 if (count > sizeof(buffer) - 1) 1444 count = sizeof(buffer) - 1; 1445 if (copy_from_user(buffer, buf, count)) 1446 return -EFAULT; 1447 1448 err = kstrtoint(strstrip(buffer), 0, &nice); 1449 if (err < 0) 1450 return err; 1451 1452 p = get_proc_task(inode); 1453 if (!p) 1454 return -ESRCH; 1455 1456 err = proc_sched_autogroup_set_nice(p, nice); 1457 if (err) 1458 count = err; 1459 1460 put_task_struct(p); 1461 1462 return count; 1463 } 1464 1465 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1466 { 1467 int ret; 1468 1469 ret = single_open(filp, sched_autogroup_show, NULL); 1470 if (!ret) { 1471 struct seq_file *m = filp->private_data; 1472 1473 m->private = inode; 1474 } 1475 return ret; 1476 } 1477 1478 static const struct file_operations proc_pid_sched_autogroup_operations = { 1479 .open = sched_autogroup_open, 1480 .read = seq_read, 1481 .write = sched_autogroup_write, 1482 .llseek = seq_lseek, 1483 .release = single_release, 1484 }; 1485 1486 #endif /* CONFIG_SCHED_AUTOGROUP */ 1487 1488 static ssize_t comm_write(struct file *file, const char __user *buf, 1489 size_t count, loff_t *offset) 1490 { 1491 struct inode *inode = file_inode(file); 1492 struct task_struct *p; 1493 char buffer[TASK_COMM_LEN]; 1494 const size_t maxlen = sizeof(buffer) - 1; 1495 1496 memset(buffer, 0, sizeof(buffer)); 1497 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count)) 1498 return -EFAULT; 1499 1500 p = get_proc_task(inode); 1501 if (!p) 1502 return -ESRCH; 1503 1504 if (same_thread_group(current, p)) 1505 set_task_comm(p, buffer); 1506 else 1507 count = -EINVAL; 1508 1509 put_task_struct(p); 1510 1511 return count; 1512 } 1513 1514 static int comm_show(struct seq_file *m, void *v) 1515 { 1516 struct inode *inode = m->private; 1517 struct task_struct *p; 1518 1519 p = get_proc_task(inode); 1520 if (!p) 1521 return -ESRCH; 1522 1523 task_lock(p); 1524 seq_printf(m, "%s\n", p->comm); 1525 task_unlock(p); 1526 1527 put_task_struct(p); 1528 1529 return 0; 1530 } 1531 1532 static int comm_open(struct inode *inode, struct file *filp) 1533 { 1534 return single_open(filp, comm_show, inode); 1535 } 1536 1537 static const struct file_operations proc_pid_set_comm_operations = { 1538 .open = comm_open, 1539 .read = seq_read, 1540 .write = comm_write, 1541 .llseek = seq_lseek, 1542 .release = single_release, 1543 }; 1544 1545 static int proc_exe_link(struct dentry *dentry, struct path *exe_path) 1546 { 1547 struct task_struct *task; 1548 struct file *exe_file; 1549 1550 task = get_proc_task(d_inode(dentry)); 1551 if (!task) 1552 return -ENOENT; 1553 exe_file = get_task_exe_file(task); 1554 put_task_struct(task); 1555 if (exe_file) { 1556 *exe_path = exe_file->f_path; 1557 path_get(&exe_file->f_path); 1558 fput(exe_file); 1559 return 0; 1560 } else 1561 return -ENOENT; 1562 } 1563 1564 static const char *proc_pid_get_link(struct dentry *dentry, 1565 struct inode *inode, 1566 struct delayed_call *done) 1567 { 1568 struct path path; 1569 int error = -EACCES; 1570 1571 if (!dentry) 1572 return ERR_PTR(-ECHILD); 1573 1574 /* Are we allowed to snoop on the tasks file descriptors? */ 1575 if (!proc_fd_access_allowed(inode)) 1576 goto out; 1577 1578 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1579 if (error) 1580 goto out; 1581 1582 nd_jump_link(&path); 1583 return NULL; 1584 out: 1585 return ERR_PTR(error); 1586 } 1587 1588 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1589 { 1590 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1591 char *pathname; 1592 int len; 1593 1594 if (!tmp) 1595 return -ENOMEM; 1596 1597 pathname = d_path(path, tmp, PAGE_SIZE); 1598 len = PTR_ERR(pathname); 1599 if (IS_ERR(pathname)) 1600 goto out; 1601 len = tmp + PAGE_SIZE - 1 - pathname; 1602 1603 if (len > buflen) 1604 len = buflen; 1605 if (copy_to_user(buffer, pathname, len)) 1606 len = -EFAULT; 1607 out: 1608 free_page((unsigned long)tmp); 1609 return len; 1610 } 1611 1612 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1613 { 1614 int error = -EACCES; 1615 struct inode *inode = d_inode(dentry); 1616 struct path path; 1617 1618 /* Are we allowed to snoop on the tasks file descriptors? */ 1619 if (!proc_fd_access_allowed(inode)) 1620 goto out; 1621 1622 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1623 if (error) 1624 goto out; 1625 1626 error = do_proc_readlink(&path, buffer, buflen); 1627 path_put(&path); 1628 out: 1629 return error; 1630 } 1631 1632 const struct inode_operations proc_pid_link_inode_operations = { 1633 .readlink = proc_pid_readlink, 1634 .get_link = proc_pid_get_link, 1635 .setattr = proc_setattr, 1636 }; 1637 1638 1639 /* building an inode */ 1640 1641 void task_dump_owner(struct task_struct *task, mode_t mode, 1642 kuid_t *ruid, kgid_t *rgid) 1643 { 1644 /* Depending on the state of dumpable compute who should own a 1645 * proc file for a task. 1646 */ 1647 const struct cred *cred; 1648 kuid_t uid; 1649 kgid_t gid; 1650 1651 /* Default to the tasks effective ownership */ 1652 rcu_read_lock(); 1653 cred = __task_cred(task); 1654 uid = cred->euid; 1655 gid = cred->egid; 1656 rcu_read_unlock(); 1657 1658 /* 1659 * Before the /proc/pid/status file was created the only way to read 1660 * the effective uid of a /process was to stat /proc/pid. Reading 1661 * /proc/pid/status is slow enough that procps and other packages 1662 * kept stating /proc/pid. To keep the rules in /proc simple I have 1663 * made this apply to all per process world readable and executable 1664 * directories. 1665 */ 1666 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) { 1667 struct mm_struct *mm; 1668 task_lock(task); 1669 mm = task->mm; 1670 /* Make non-dumpable tasks owned by some root */ 1671 if (mm) { 1672 if (get_dumpable(mm) != SUID_DUMP_USER) { 1673 struct user_namespace *user_ns = mm->user_ns; 1674 1675 uid = make_kuid(user_ns, 0); 1676 if (!uid_valid(uid)) 1677 uid = GLOBAL_ROOT_UID; 1678 1679 gid = make_kgid(user_ns, 0); 1680 if (!gid_valid(gid)) 1681 gid = GLOBAL_ROOT_GID; 1682 } 1683 } else { 1684 uid = GLOBAL_ROOT_UID; 1685 gid = GLOBAL_ROOT_GID; 1686 } 1687 task_unlock(task); 1688 } 1689 *ruid = uid; 1690 *rgid = gid; 1691 } 1692 1693 struct inode *proc_pid_make_inode(struct super_block * sb, 1694 struct task_struct *task, umode_t mode) 1695 { 1696 struct inode * inode; 1697 struct proc_inode *ei; 1698 1699 /* We need a new inode */ 1700 1701 inode = new_inode(sb); 1702 if (!inode) 1703 goto out; 1704 1705 /* Common stuff */ 1706 ei = PROC_I(inode); 1707 inode->i_mode = mode; 1708 inode->i_ino = get_next_ino(); 1709 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 1710 inode->i_op = &proc_def_inode_operations; 1711 1712 /* 1713 * grab the reference to task. 1714 */ 1715 ei->pid = get_task_pid(task, PIDTYPE_PID); 1716 if (!ei->pid) 1717 goto out_unlock; 1718 1719 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); 1720 security_task_to_inode(task, inode); 1721 1722 out: 1723 return inode; 1724 1725 out_unlock: 1726 iput(inode); 1727 return NULL; 1728 } 1729 1730 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1731 { 1732 struct inode *inode = d_inode(dentry); 1733 struct task_struct *task; 1734 struct pid_namespace *pid = 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 /* 2835 * Thread groups 2836 */ 2837 static const struct file_operations proc_task_operations; 2838 static const struct inode_operations proc_task_inode_operations; 2839 2840 static const struct pid_entry tgid_base_stuff[] = { 2841 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2842 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2843 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 2844 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2845 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2846 #ifdef CONFIG_NET 2847 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2848 #endif 2849 REG("environ", S_IRUSR, proc_environ_operations), 2850 REG("auxv", S_IRUSR, proc_auxv_operations), 2851 ONE("status", S_IRUGO, proc_pid_status), 2852 ONE("personality", S_IRUSR, proc_pid_personality), 2853 ONE("limits", S_IRUGO, proc_pid_limits), 2854 #ifdef CONFIG_SCHED_DEBUG 2855 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2856 #endif 2857 #ifdef CONFIG_SCHED_AUTOGROUP 2858 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2859 #endif 2860 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2861 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2862 ONE("syscall", S_IRUSR, proc_pid_syscall), 2863 #endif 2864 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 2865 ONE("stat", S_IRUGO, proc_tgid_stat), 2866 ONE("statm", S_IRUGO, proc_pid_statm), 2867 REG("maps", S_IRUGO, proc_pid_maps_operations), 2868 #ifdef CONFIG_NUMA 2869 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 2870 #endif 2871 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2872 LNK("cwd", proc_cwd_link), 2873 LNK("root", proc_root_link), 2874 LNK("exe", proc_exe_link), 2875 REG("mounts", S_IRUGO, proc_mounts_operations), 2876 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2877 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2878 #ifdef CONFIG_PROC_PAGE_MONITOR 2879 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2880 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 2881 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2882 #endif 2883 #ifdef CONFIG_SECURITY 2884 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2885 #endif 2886 #ifdef CONFIG_KALLSYMS 2887 ONE("wchan", S_IRUGO, proc_pid_wchan), 2888 #endif 2889 #ifdef CONFIG_STACKTRACE 2890 ONE("stack", S_IRUSR, proc_pid_stack), 2891 #endif 2892 #ifdef CONFIG_SCHED_INFO 2893 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 2894 #endif 2895 #ifdef CONFIG_LATENCYTOP 2896 REG("latency", S_IRUGO, proc_lstats_operations), 2897 #endif 2898 #ifdef CONFIG_PROC_PID_CPUSET 2899 ONE("cpuset", S_IRUGO, proc_cpuset_show), 2900 #endif 2901 #ifdef CONFIG_CGROUPS 2902 ONE("cgroup", S_IRUGO, proc_cgroup_show), 2903 #endif 2904 ONE("oom_score", S_IRUGO, proc_oom_score), 2905 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 2906 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2907 #ifdef CONFIG_AUDITSYSCALL 2908 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2909 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2910 #endif 2911 #ifdef CONFIG_FAULT_INJECTION 2912 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2913 #endif 2914 #ifdef CONFIG_ELF_CORE 2915 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2916 #endif 2917 #ifdef CONFIG_TASK_IO_ACCOUNTING 2918 ONE("io", S_IRUSR, proc_tgid_io_accounting), 2919 #endif 2920 #ifdef CONFIG_HARDWALL 2921 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 2922 #endif 2923 #ifdef CONFIG_USER_NS 2924 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 2925 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 2926 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 2927 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 2928 #endif 2929 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS) 2930 REG("timers", S_IRUGO, proc_timers_operations), 2931 #endif 2932 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations), 2933 }; 2934 2935 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) 2936 { 2937 return proc_pident_readdir(file, ctx, 2938 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2939 } 2940 2941 static const struct file_operations proc_tgid_base_operations = { 2942 .read = generic_read_dir, 2943 .iterate_shared = proc_tgid_base_readdir, 2944 .llseek = generic_file_llseek, 2945 }; 2946 2947 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 2948 { 2949 return proc_pident_lookup(dir, dentry, 2950 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2951 } 2952 2953 static const struct inode_operations proc_tgid_base_inode_operations = { 2954 .lookup = proc_tgid_base_lookup, 2955 .getattr = pid_getattr, 2956 .setattr = proc_setattr, 2957 .permission = proc_pid_permission, 2958 }; 2959 2960 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2961 { 2962 struct dentry *dentry, *leader, *dir; 2963 char buf[PROC_NUMBUF]; 2964 struct qstr name; 2965 2966 name.name = buf; 2967 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2968 /* no ->d_hash() rejects on procfs */ 2969 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2970 if (dentry) { 2971 d_invalidate(dentry); 2972 dput(dentry); 2973 } 2974 2975 if (pid == tgid) 2976 return; 2977 2978 name.name = buf; 2979 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2980 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2981 if (!leader) 2982 goto out; 2983 2984 name.name = "task"; 2985 name.len = strlen(name.name); 2986 dir = d_hash_and_lookup(leader, &name); 2987 if (!dir) 2988 goto out_put_leader; 2989 2990 name.name = buf; 2991 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2992 dentry = d_hash_and_lookup(dir, &name); 2993 if (dentry) { 2994 d_invalidate(dentry); 2995 dput(dentry); 2996 } 2997 2998 dput(dir); 2999 out_put_leader: 3000 dput(leader); 3001 out: 3002 return; 3003 } 3004 3005 /** 3006 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 3007 * @task: task that should be flushed. 3008 * 3009 * When flushing dentries from proc, one needs to flush them from global 3010 * proc (proc_mnt) and from all the namespaces' procs this task was seen 3011 * in. This call is supposed to do all of this job. 3012 * 3013 * Looks in the dcache for 3014 * /proc/@pid 3015 * /proc/@tgid/task/@pid 3016 * if either directory is present flushes it and all of it'ts children 3017 * from the dcache. 3018 * 3019 * It is safe and reasonable to cache /proc entries for a task until 3020 * that task exits. After that they just clog up the dcache with 3021 * useless entries, possibly causing useful dcache entries to be 3022 * flushed instead. This routine is proved to flush those useless 3023 * dcache entries at process exit time. 3024 * 3025 * NOTE: This routine is just an optimization so it does not guarantee 3026 * that no dcache entries will exist at process exit time it 3027 * just makes it very unlikely that any will persist. 3028 */ 3029 3030 void proc_flush_task(struct task_struct *task) 3031 { 3032 int i; 3033 struct pid *pid, *tgid; 3034 struct upid *upid; 3035 3036 pid = task_pid(task); 3037 tgid = task_tgid(task); 3038 3039 for (i = 0; i <= pid->level; i++) { 3040 upid = &pid->numbers[i]; 3041 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3042 tgid->numbers[i].nr); 3043 } 3044 } 3045 3046 static int proc_pid_instantiate(struct inode *dir, 3047 struct dentry * dentry, 3048 struct task_struct *task, const void *ptr) 3049 { 3050 struct inode *inode; 3051 3052 inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3053 if (!inode) 3054 goto out; 3055 3056 inode->i_op = &proc_tgid_base_inode_operations; 3057 inode->i_fop = &proc_tgid_base_operations; 3058 inode->i_flags|=S_IMMUTABLE; 3059 3060 set_nlink(inode, nlink_tgid); 3061 3062 d_set_d_op(dentry, &pid_dentry_operations); 3063 3064 d_add(dentry, inode); 3065 /* Close the race of the process dying before we return the dentry */ 3066 if (pid_revalidate(dentry, 0)) 3067 return 0; 3068 out: 3069 return -ENOENT; 3070 } 3071 3072 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3073 { 3074 int result = -ENOENT; 3075 struct task_struct *task; 3076 unsigned tgid; 3077 struct pid_namespace *ns; 3078 3079 tgid = name_to_int(&dentry->d_name); 3080 if (tgid == ~0U) 3081 goto out; 3082 3083 ns = dentry->d_sb->s_fs_info; 3084 rcu_read_lock(); 3085 task = find_task_by_pid_ns(tgid, ns); 3086 if (task) 3087 get_task_struct(task); 3088 rcu_read_unlock(); 3089 if (!task) 3090 goto out; 3091 3092 result = proc_pid_instantiate(dir, dentry, task, NULL); 3093 put_task_struct(task); 3094 out: 3095 return ERR_PTR(result); 3096 } 3097 3098 /* 3099 * Find the first task with tgid >= tgid 3100 * 3101 */ 3102 struct tgid_iter { 3103 unsigned int tgid; 3104 struct task_struct *task; 3105 }; 3106 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3107 { 3108 struct pid *pid; 3109 3110 if (iter.task) 3111 put_task_struct(iter.task); 3112 rcu_read_lock(); 3113 retry: 3114 iter.task = NULL; 3115 pid = find_ge_pid(iter.tgid, ns); 3116 if (pid) { 3117 iter.tgid = pid_nr_ns(pid, ns); 3118 iter.task = pid_task(pid, PIDTYPE_PID); 3119 /* What we to know is if the pid we have find is the 3120 * pid of a thread_group_leader. Testing for task 3121 * being a thread_group_leader is the obvious thing 3122 * todo but there is a window when it fails, due to 3123 * the pid transfer logic in de_thread. 3124 * 3125 * So we perform the straight forward test of seeing 3126 * if the pid we have found is the pid of a thread 3127 * group leader, and don't worry if the task we have 3128 * found doesn't happen to be a thread group leader. 3129 * As we don't care in the case of readdir. 3130 */ 3131 if (!iter.task || !has_group_leader_pid(iter.task)) { 3132 iter.tgid += 1; 3133 goto retry; 3134 } 3135 get_task_struct(iter.task); 3136 } 3137 rcu_read_unlock(); 3138 return iter; 3139 } 3140 3141 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2) 3142 3143 /* for the /proc/ directory itself, after non-process stuff has been done */ 3144 int proc_pid_readdir(struct file *file, struct dir_context *ctx) 3145 { 3146 struct tgid_iter iter; 3147 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info; 3148 loff_t pos = ctx->pos; 3149 3150 if (pos >= PID_MAX_LIMIT + TGID_OFFSET) 3151 return 0; 3152 3153 if (pos == TGID_OFFSET - 2) { 3154 struct inode *inode = d_inode(ns->proc_self); 3155 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) 3156 return 0; 3157 ctx->pos = pos = pos + 1; 3158 } 3159 if (pos == TGID_OFFSET - 1) { 3160 struct inode *inode = d_inode(ns->proc_thread_self); 3161 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) 3162 return 0; 3163 ctx->pos = pos = pos + 1; 3164 } 3165 iter.tgid = pos - TGID_OFFSET; 3166 iter.task = NULL; 3167 for (iter = next_tgid(ns, iter); 3168 iter.task; 3169 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3170 char name[PROC_NUMBUF]; 3171 int len; 3172 3173 cond_resched(); 3174 if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE)) 3175 continue; 3176 3177 len = snprintf(name, sizeof(name), "%d", iter.tgid); 3178 ctx->pos = iter.tgid + TGID_OFFSET; 3179 if (!proc_fill_cache(file, ctx, name, len, 3180 proc_pid_instantiate, iter.task, NULL)) { 3181 put_task_struct(iter.task); 3182 return 0; 3183 } 3184 } 3185 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET; 3186 return 0; 3187 } 3188 3189 /* 3190 * proc_tid_comm_permission is a special permission function exclusively 3191 * used for the node /proc/<pid>/task/<tid>/comm. 3192 * It bypasses generic permission checks in the case where a task of the same 3193 * task group attempts to access the node. 3194 * The rationale behind this is that glibc and bionic access this node for 3195 * cross thread naming (pthread_set/getname_np(!self)). However, if 3196 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0, 3197 * which locks out the cross thread naming implementation. 3198 * This function makes sure that the node is always accessible for members of 3199 * same thread group. 3200 */ 3201 static int proc_tid_comm_permission(struct inode *inode, int mask) 3202 { 3203 bool is_same_tgroup; 3204 struct task_struct *task; 3205 3206 task = get_proc_task(inode); 3207 if (!task) 3208 return -ESRCH; 3209 is_same_tgroup = same_thread_group(current, task); 3210 put_task_struct(task); 3211 3212 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) { 3213 /* This file (/proc/<pid>/task/<tid>/comm) can always be 3214 * read or written by the members of the corresponding 3215 * thread group. 3216 */ 3217 return 0; 3218 } 3219 3220 return generic_permission(inode, mask); 3221 } 3222 3223 static const struct inode_operations proc_tid_comm_inode_operations = { 3224 .permission = proc_tid_comm_permission, 3225 }; 3226 3227 /* 3228 * Tasks 3229 */ 3230 static const struct pid_entry tid_base_stuff[] = { 3231 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3232 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3233 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3234 #ifdef CONFIG_NET 3235 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3236 #endif 3237 REG("environ", S_IRUSR, proc_environ_operations), 3238 REG("auxv", S_IRUSR, proc_auxv_operations), 3239 ONE("status", S_IRUGO, proc_pid_status), 3240 ONE("personality", S_IRUSR, proc_pid_personality), 3241 ONE("limits", S_IRUGO, proc_pid_limits), 3242 #ifdef CONFIG_SCHED_DEBUG 3243 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3244 #endif 3245 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR, 3246 &proc_tid_comm_inode_operations, 3247 &proc_pid_set_comm_operations, {}), 3248 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3249 ONE("syscall", S_IRUSR, proc_pid_syscall), 3250 #endif 3251 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 3252 ONE("stat", S_IRUGO, proc_tid_stat), 3253 ONE("statm", S_IRUGO, proc_pid_statm), 3254 REG("maps", S_IRUGO, proc_tid_maps_operations), 3255 #ifdef CONFIG_PROC_CHILDREN 3256 REG("children", S_IRUGO, proc_tid_children_operations), 3257 #endif 3258 #ifdef CONFIG_NUMA 3259 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations), 3260 #endif 3261 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3262 LNK("cwd", proc_cwd_link), 3263 LNK("root", proc_root_link), 3264 LNK("exe", proc_exe_link), 3265 REG("mounts", S_IRUGO, proc_mounts_operations), 3266 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3267 #ifdef CONFIG_PROC_PAGE_MONITOR 3268 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3269 REG("smaps", S_IRUGO, proc_tid_smaps_operations), 3270 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3271 #endif 3272 #ifdef CONFIG_SECURITY 3273 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3274 #endif 3275 #ifdef CONFIG_KALLSYMS 3276 ONE("wchan", S_IRUGO, proc_pid_wchan), 3277 #endif 3278 #ifdef CONFIG_STACKTRACE 3279 ONE("stack", S_IRUSR, proc_pid_stack), 3280 #endif 3281 #ifdef CONFIG_SCHED_INFO 3282 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 3283 #endif 3284 #ifdef CONFIG_LATENCYTOP 3285 REG("latency", S_IRUGO, proc_lstats_operations), 3286 #endif 3287 #ifdef CONFIG_PROC_PID_CPUSET 3288 ONE("cpuset", S_IRUGO, proc_cpuset_show), 3289 #endif 3290 #ifdef CONFIG_CGROUPS 3291 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3292 #endif 3293 ONE("oom_score", S_IRUGO, proc_oom_score), 3294 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3295 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3296 #ifdef CONFIG_AUDITSYSCALL 3297 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3298 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3299 #endif 3300 #ifdef CONFIG_FAULT_INJECTION 3301 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3302 #endif 3303 #ifdef CONFIG_TASK_IO_ACCOUNTING 3304 ONE("io", S_IRUSR, proc_tid_io_accounting), 3305 #endif 3306 #ifdef CONFIG_HARDWALL 3307 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 3308 #endif 3309 #ifdef CONFIG_USER_NS 3310 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3311 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3312 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3313 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3314 #endif 3315 }; 3316 3317 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx) 3318 { 3319 return proc_pident_readdir(file, ctx, 3320 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3321 } 3322 3323 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3324 { 3325 return proc_pident_lookup(dir, dentry, 3326 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3327 } 3328 3329 static const struct file_operations proc_tid_base_operations = { 3330 .read = generic_read_dir, 3331 .iterate_shared = proc_tid_base_readdir, 3332 .llseek = generic_file_llseek, 3333 }; 3334 3335 static const struct inode_operations proc_tid_base_inode_operations = { 3336 .lookup = proc_tid_base_lookup, 3337 .getattr = pid_getattr, 3338 .setattr = proc_setattr, 3339 }; 3340 3341 static int proc_task_instantiate(struct inode *dir, 3342 struct dentry *dentry, struct task_struct *task, const void *ptr) 3343 { 3344 struct inode *inode; 3345 inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3346 3347 if (!inode) 3348 goto out; 3349 inode->i_op = &proc_tid_base_inode_operations; 3350 inode->i_fop = &proc_tid_base_operations; 3351 inode->i_flags|=S_IMMUTABLE; 3352 3353 set_nlink(inode, nlink_tid); 3354 3355 d_set_d_op(dentry, &pid_dentry_operations); 3356 3357 d_add(dentry, inode); 3358 /* Close the race of the process dying before we return the dentry */ 3359 if (pid_revalidate(dentry, 0)) 3360 return 0; 3361 out: 3362 return -ENOENT; 3363 } 3364 3365 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3366 { 3367 int result = -ENOENT; 3368 struct task_struct *task; 3369 struct task_struct *leader = get_proc_task(dir); 3370 unsigned tid; 3371 struct pid_namespace *ns; 3372 3373 if (!leader) 3374 goto out_no_task; 3375 3376 tid = name_to_int(&dentry->d_name); 3377 if (tid == ~0U) 3378 goto out; 3379 3380 ns = dentry->d_sb->s_fs_info; 3381 rcu_read_lock(); 3382 task = find_task_by_pid_ns(tid, ns); 3383 if (task) 3384 get_task_struct(task); 3385 rcu_read_unlock(); 3386 if (!task) 3387 goto out; 3388 if (!same_thread_group(leader, task)) 3389 goto out_drop_task; 3390 3391 result = proc_task_instantiate(dir, dentry, task, NULL); 3392 out_drop_task: 3393 put_task_struct(task); 3394 out: 3395 put_task_struct(leader); 3396 out_no_task: 3397 return ERR_PTR(result); 3398 } 3399 3400 /* 3401 * Find the first tid of a thread group to return to user space. 3402 * 3403 * Usually this is just the thread group leader, but if the users 3404 * buffer was too small or there was a seek into the middle of the 3405 * directory we have more work todo. 3406 * 3407 * In the case of a short read we start with find_task_by_pid. 3408 * 3409 * In the case of a seek we start with the leader and walk nr 3410 * threads past it. 3411 */ 3412 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos, 3413 struct pid_namespace *ns) 3414 { 3415 struct task_struct *pos, *task; 3416 unsigned long nr = f_pos; 3417 3418 if (nr != f_pos) /* 32bit overflow? */ 3419 return NULL; 3420 3421 rcu_read_lock(); 3422 task = pid_task(pid, PIDTYPE_PID); 3423 if (!task) 3424 goto fail; 3425 3426 /* Attempt to start with the tid of a thread */ 3427 if (tid && nr) { 3428 pos = find_task_by_pid_ns(tid, ns); 3429 if (pos && same_thread_group(pos, task)) 3430 goto found; 3431 } 3432 3433 /* If nr exceeds the number of threads there is nothing todo */ 3434 if (nr >= get_nr_threads(task)) 3435 goto fail; 3436 3437 /* If we haven't found our starting place yet start 3438 * with the leader and walk nr threads forward. 3439 */ 3440 pos = task = task->group_leader; 3441 do { 3442 if (!nr--) 3443 goto found; 3444 } while_each_thread(task, pos); 3445 fail: 3446 pos = NULL; 3447 goto out; 3448 found: 3449 get_task_struct(pos); 3450 out: 3451 rcu_read_unlock(); 3452 return pos; 3453 } 3454 3455 /* 3456 * Find the next thread in the thread list. 3457 * Return NULL if there is an error or no next thread. 3458 * 3459 * The reference to the input task_struct is released. 3460 */ 3461 static struct task_struct *next_tid(struct task_struct *start) 3462 { 3463 struct task_struct *pos = NULL; 3464 rcu_read_lock(); 3465 if (pid_alive(start)) { 3466 pos = next_thread(start); 3467 if (thread_group_leader(pos)) 3468 pos = NULL; 3469 else 3470 get_task_struct(pos); 3471 } 3472 rcu_read_unlock(); 3473 put_task_struct(start); 3474 return pos; 3475 } 3476 3477 /* for the /proc/TGID/task/ directories */ 3478 static int proc_task_readdir(struct file *file, struct dir_context *ctx) 3479 { 3480 struct inode *inode = file_inode(file); 3481 struct task_struct *task; 3482 struct pid_namespace *ns; 3483 int tid; 3484 3485 if (proc_inode_is_dead(inode)) 3486 return -ENOENT; 3487 3488 if (!dir_emit_dots(file, ctx)) 3489 return 0; 3490 3491 /* f_version caches the tgid value that the last readdir call couldn't 3492 * return. lseek aka telldir automagically resets f_version to 0. 3493 */ 3494 ns = inode->i_sb->s_fs_info; 3495 tid = (int)file->f_version; 3496 file->f_version = 0; 3497 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); 3498 task; 3499 task = next_tid(task), ctx->pos++) { 3500 char name[PROC_NUMBUF]; 3501 int len; 3502 tid = task_pid_nr_ns(task, ns); 3503 len = snprintf(name, sizeof(name), "%d", tid); 3504 if (!proc_fill_cache(file, ctx, name, len, 3505 proc_task_instantiate, task, NULL)) { 3506 /* returning this tgid failed, save it as the first 3507 * pid for the next readir call */ 3508 file->f_version = (u64)tid; 3509 put_task_struct(task); 3510 break; 3511 } 3512 } 3513 3514 return 0; 3515 } 3516 3517 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3518 { 3519 struct inode *inode = d_inode(dentry); 3520 struct task_struct *p = get_proc_task(inode); 3521 generic_fillattr(inode, stat); 3522 3523 if (p) { 3524 stat->nlink += get_nr_threads(p); 3525 put_task_struct(p); 3526 } 3527 3528 return 0; 3529 } 3530 3531 static const struct inode_operations proc_task_inode_operations = { 3532 .lookup = proc_task_lookup, 3533 .getattr = proc_task_getattr, 3534 .setattr = proc_setattr, 3535 .permission = proc_pid_permission, 3536 }; 3537 3538 static const struct file_operations proc_task_operations = { 3539 .read = generic_read_dir, 3540 .iterate_shared = proc_task_readdir, 3541 .llseek = generic_file_llseek, 3542 }; 3543 3544 void __init set_proc_pid_nlink(void) 3545 { 3546 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3547 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3548 } 3549