1 /* 2 * linux/fs/proc/base.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 * 6 * proc base directory handling functions 7 * 8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part. 9 * Instead of using magical inumbers to determine the kind of object 10 * we allocate and fill in-core inodes upon lookup. They don't even 11 * go into icache. We cache the reference to task_struct upon lookup too. 12 * Eventually it should become a filesystem in its own. We don't use the 13 * rest of procfs anymore. 14 * 15 * 16 * Changelog: 17 * 17-Jan-2005 18 * Allan Bezerra 19 * Bruna Moreira <bruna.moreira@indt.org.br> 20 * Edjard Mota <edjard.mota@indt.org.br> 21 * Ilias Biris <ilias.biris@indt.org.br> 22 * Mauricio Lin <mauricio.lin@indt.org.br> 23 * 24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 25 * 26 * A new process specific entry (smaps) included in /proc. It shows the 27 * size of rss for each memory area. The maps entry lacks information 28 * about physical memory size (rss) for each mapped file, i.e., 29 * rss information for executables and library files. 30 * This additional information is useful for any tools that need to know 31 * about physical memory consumption for a process specific library. 32 * 33 * Changelog: 34 * 21-Feb-2005 35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 36 * Pud inclusion in the page table walking. 37 * 38 * ChangeLog: 39 * 10-Mar-2005 40 * 10LE Instituto Nokia de Tecnologia - INdT: 41 * A better way to walks through the page table as suggested by Hugh Dickins. 42 * 43 * Simo Piiroinen <simo.piiroinen@nokia.com>: 44 * Smaps information related to shared, private, clean and dirty pages. 45 * 46 * Paul Mundt <paul.mundt@nokia.com>: 47 * Overall revision about smaps. 48 */ 49 50 #include <linux/uaccess.h> 51 52 #include <linux/errno.h> 53 #include <linux/time.h> 54 #include <linux/proc_fs.h> 55 #include <linux/stat.h> 56 #include <linux/task_io_accounting_ops.h> 57 #include <linux/init.h> 58 #include <linux/capability.h> 59 #include <linux/file.h> 60 #include <linux/fdtable.h> 61 #include <linux/string.h> 62 #include <linux/seq_file.h> 63 #include <linux/namei.h> 64 #include <linux/mnt_namespace.h> 65 #include <linux/mm.h> 66 #include <linux/swap.h> 67 #include <linux/rcupdate.h> 68 #include <linux/kallsyms.h> 69 #include <linux/stacktrace.h> 70 #include <linux/resource.h> 71 #include <linux/module.h> 72 #include <linux/mount.h> 73 #include <linux/security.h> 74 #include <linux/ptrace.h> 75 #include <linux/tracehook.h> 76 #include <linux/printk.h> 77 #include <linux/cgroup.h> 78 #include <linux/cpuset.h> 79 #include <linux/audit.h> 80 #include <linux/poll.h> 81 #include <linux/nsproxy.h> 82 #include <linux/oom.h> 83 #include <linux/elf.h> 84 #include <linux/pid_namespace.h> 85 #include <linux/user_namespace.h> 86 #include <linux/fs_struct.h> 87 #include <linux/slab.h> 88 #include <linux/sched/autogroup.h> 89 #include <linux/sched/mm.h> 90 #include <linux/sched/coredump.h> 91 #include <linux/sched/debug.h> 92 #include <linux/sched/stat.h> 93 #include <linux/flex_array.h> 94 #include <linux/posix-timers.h> 95 #ifdef CONFIG_HARDWALL 96 #include <asm/hardwall.h> 97 #endif 98 #include <trace/events/oom.h> 99 #include "internal.h" 100 #include "fd.h" 101 102 /* NOTE: 103 * Implementing inode permission operations in /proc is almost 104 * certainly an error. Permission checks need to happen during 105 * each system call not at open time. The reason is that most of 106 * what we wish to check for permissions in /proc varies at runtime. 107 * 108 * The classic example of a problem is opening file descriptors 109 * in /proc for a task before it execs a suid executable. 110 */ 111 112 static u8 nlink_tid; 113 static u8 nlink_tgid; 114 115 struct pid_entry { 116 const char *name; 117 unsigned int len; 118 umode_t mode; 119 const struct inode_operations *iop; 120 const struct file_operations *fop; 121 union proc_op op; 122 }; 123 124 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 125 .name = (NAME), \ 126 .len = sizeof(NAME) - 1, \ 127 .mode = MODE, \ 128 .iop = IOP, \ 129 .fop = FOP, \ 130 .op = OP, \ 131 } 132 133 #define DIR(NAME, MODE, iops, fops) \ 134 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} ) 135 #define LNK(NAME, get_link) \ 136 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 137 &proc_pid_link_inode_operations, NULL, \ 138 { .proc_get_link = get_link } ) 139 #define REG(NAME, MODE, fops) \ 140 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {}) 141 #define ONE(NAME, MODE, show) \ 142 NOD(NAME, (S_IFREG|(MODE)), \ 143 NULL, &proc_single_file_operations, \ 144 { .proc_show = show } ) 145 146 /* 147 * Count the number of hardlinks for the pid_entry table, excluding the . 148 * and .. links. 149 */ 150 static unsigned int __init pid_entry_nlink(const struct pid_entry *entries, 151 unsigned int n) 152 { 153 unsigned int i; 154 unsigned int count; 155 156 count = 2; 157 for (i = 0; i < n; ++i) { 158 if (S_ISDIR(entries[i].mode)) 159 ++count; 160 } 161 162 return count; 163 } 164 165 static int get_task_root(struct task_struct *task, struct path *root) 166 { 167 int result = -ENOENT; 168 169 task_lock(task); 170 if (task->fs) { 171 get_fs_root(task->fs, root); 172 result = 0; 173 } 174 task_unlock(task); 175 return result; 176 } 177 178 static int proc_cwd_link(struct dentry *dentry, struct path *path) 179 { 180 struct task_struct *task = get_proc_task(d_inode(dentry)); 181 int result = -ENOENT; 182 183 if (task) { 184 task_lock(task); 185 if (task->fs) { 186 get_fs_pwd(task->fs, path); 187 result = 0; 188 } 189 task_unlock(task); 190 put_task_struct(task); 191 } 192 return result; 193 } 194 195 static int proc_root_link(struct dentry *dentry, struct path *path) 196 { 197 struct task_struct *task = get_proc_task(d_inode(dentry)); 198 int result = -ENOENT; 199 200 if (task) { 201 result = get_task_root(task, path); 202 put_task_struct(task); 203 } 204 return result; 205 } 206 207 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, 208 size_t _count, loff_t *pos) 209 { 210 struct task_struct *tsk; 211 struct mm_struct *mm; 212 char *page; 213 unsigned long count = _count; 214 unsigned long arg_start, arg_end, env_start, env_end; 215 unsigned long len1, len2, len; 216 unsigned long p; 217 char c; 218 ssize_t rv; 219 220 BUG_ON(*pos < 0); 221 222 tsk = get_proc_task(file_inode(file)); 223 if (!tsk) 224 return -ESRCH; 225 mm = get_task_mm(tsk); 226 put_task_struct(tsk); 227 if (!mm) 228 return 0; 229 /* Check if process spawned far enough to have cmdline. */ 230 if (!mm->env_end) { 231 rv = 0; 232 goto out_mmput; 233 } 234 235 page = (char *)__get_free_page(GFP_TEMPORARY); 236 if (!page) { 237 rv = -ENOMEM; 238 goto out_mmput; 239 } 240 241 down_read(&mm->mmap_sem); 242 arg_start = mm->arg_start; 243 arg_end = mm->arg_end; 244 env_start = mm->env_start; 245 env_end = mm->env_end; 246 up_read(&mm->mmap_sem); 247 248 BUG_ON(arg_start > arg_end); 249 BUG_ON(env_start > env_end); 250 251 len1 = arg_end - arg_start; 252 len2 = env_end - env_start; 253 254 /* Empty ARGV. */ 255 if (len1 == 0) { 256 rv = 0; 257 goto out_free_page; 258 } 259 /* 260 * Inherently racy -- command line shares address space 261 * with code and data. 262 */ 263 rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0); 264 if (rv <= 0) 265 goto out_free_page; 266 267 rv = 0; 268 269 if (c == '\0') { 270 /* Command line (set of strings) occupies whole ARGV. */ 271 if (len1 <= *pos) 272 goto out_free_page; 273 274 p = arg_start + *pos; 275 len = len1 - *pos; 276 while (count > 0 && len > 0) { 277 unsigned int _count; 278 int nr_read; 279 280 _count = min3(count, len, PAGE_SIZE); 281 nr_read = access_remote_vm(mm, p, page, _count, 0); 282 if (nr_read < 0) 283 rv = nr_read; 284 if (nr_read <= 0) 285 goto out_free_page; 286 287 if (copy_to_user(buf, page, nr_read)) { 288 rv = -EFAULT; 289 goto out_free_page; 290 } 291 292 p += nr_read; 293 len -= nr_read; 294 buf += nr_read; 295 count -= nr_read; 296 rv += nr_read; 297 } 298 } else { 299 /* 300 * Command line (1 string) occupies ARGV and 301 * extends into ENVP. 302 */ 303 struct { 304 unsigned long p; 305 unsigned long len; 306 } cmdline[2] = { 307 { .p = arg_start, .len = len1 }, 308 { .p = env_start, .len = len2 }, 309 }; 310 loff_t pos1 = *pos; 311 unsigned int i; 312 313 i = 0; 314 while (i < 2 && pos1 >= cmdline[i].len) { 315 pos1 -= cmdline[i].len; 316 i++; 317 } 318 while (i < 2) { 319 p = cmdline[i].p + pos1; 320 len = cmdline[i].len - pos1; 321 while (count > 0 && len > 0) { 322 unsigned int _count, l; 323 int nr_read; 324 bool final; 325 326 _count = min3(count, len, PAGE_SIZE); 327 nr_read = access_remote_vm(mm, p, page, _count, 0); 328 if (nr_read < 0) 329 rv = nr_read; 330 if (nr_read <= 0) 331 goto out_free_page; 332 333 /* 334 * Command line can be shorter than whole ARGV 335 * even if last "marker" byte says it is not. 336 */ 337 final = false; 338 l = strnlen(page, nr_read); 339 if (l < nr_read) { 340 nr_read = l; 341 final = true; 342 } 343 344 if (copy_to_user(buf, page, nr_read)) { 345 rv = -EFAULT; 346 goto out_free_page; 347 } 348 349 p += nr_read; 350 len -= nr_read; 351 buf += nr_read; 352 count -= nr_read; 353 rv += nr_read; 354 355 if (final) 356 goto out_free_page; 357 } 358 359 /* Only first chunk can be read partially. */ 360 pos1 = 0; 361 i++; 362 } 363 } 364 365 out_free_page: 366 free_page((unsigned long)page); 367 out_mmput: 368 mmput(mm); 369 if (rv > 0) 370 *pos += rv; 371 return rv; 372 } 373 374 static const struct file_operations proc_pid_cmdline_ops = { 375 .read = proc_pid_cmdline_read, 376 .llseek = generic_file_llseek, 377 }; 378 379 #ifdef CONFIG_KALLSYMS 380 /* 381 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 382 * Returns the resolved symbol. If that fails, simply return the address. 383 */ 384 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns, 385 struct pid *pid, struct task_struct *task) 386 { 387 unsigned long wchan; 388 char symname[KSYM_NAME_LEN]; 389 390 wchan = get_wchan(task); 391 392 if (wchan && ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS) 393 && !lookup_symbol_name(wchan, symname)) 394 seq_printf(m, "%s", symname); 395 else 396 seq_putc(m, '0'); 397 398 return 0; 399 } 400 #endif /* CONFIG_KALLSYMS */ 401 402 static int lock_trace(struct task_struct *task) 403 { 404 int err = mutex_lock_killable(&task->signal->cred_guard_mutex); 405 if (err) 406 return err; 407 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) { 408 mutex_unlock(&task->signal->cred_guard_mutex); 409 return -EPERM; 410 } 411 return 0; 412 } 413 414 static void unlock_trace(struct task_struct *task) 415 { 416 mutex_unlock(&task->signal->cred_guard_mutex); 417 } 418 419 #ifdef CONFIG_STACKTRACE 420 421 #define MAX_STACK_TRACE_DEPTH 64 422 423 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, 424 struct pid *pid, struct task_struct *task) 425 { 426 struct stack_trace trace; 427 unsigned long *entries; 428 int err; 429 int i; 430 431 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL); 432 if (!entries) 433 return -ENOMEM; 434 435 trace.nr_entries = 0; 436 trace.max_entries = MAX_STACK_TRACE_DEPTH; 437 trace.entries = entries; 438 trace.skip = 0; 439 440 err = lock_trace(task); 441 if (!err) { 442 save_stack_trace_tsk(task, &trace); 443 444 for (i = 0; i < trace.nr_entries; i++) { 445 seq_printf(m, "[<%pK>] %pB\n", 446 (void *)entries[i], (void *)entries[i]); 447 } 448 unlock_trace(task); 449 } 450 kfree(entries); 451 452 return err; 453 } 454 #endif 455 456 #ifdef CONFIG_SCHED_INFO 457 /* 458 * Provides /proc/PID/schedstat 459 */ 460 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, 461 struct pid *pid, struct task_struct *task) 462 { 463 if (unlikely(!sched_info_on())) 464 seq_printf(m, "0 0 0\n"); 465 else 466 seq_printf(m, "%llu %llu %lu\n", 467 (unsigned long long)task->se.sum_exec_runtime, 468 (unsigned long long)task->sched_info.run_delay, 469 task->sched_info.pcount); 470 471 return 0; 472 } 473 #endif 474 475 #ifdef CONFIG_LATENCYTOP 476 static int lstats_show_proc(struct seq_file *m, void *v) 477 { 478 int i; 479 struct inode *inode = m->private; 480 struct task_struct *task = get_proc_task(inode); 481 482 if (!task) 483 return -ESRCH; 484 seq_puts(m, "Latency Top version : v0.1\n"); 485 for (i = 0; i < 32; i++) { 486 struct latency_record *lr = &task->latency_record[i]; 487 if (lr->backtrace[0]) { 488 int q; 489 seq_printf(m, "%i %li %li", 490 lr->count, lr->time, lr->max); 491 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 492 unsigned long bt = lr->backtrace[q]; 493 if (!bt) 494 break; 495 if (bt == ULONG_MAX) 496 break; 497 seq_printf(m, " %ps", (void *)bt); 498 } 499 seq_putc(m, '\n'); 500 } 501 502 } 503 put_task_struct(task); 504 return 0; 505 } 506 507 static int lstats_open(struct inode *inode, struct file *file) 508 { 509 return single_open(file, lstats_show_proc, inode); 510 } 511 512 static ssize_t lstats_write(struct file *file, const char __user *buf, 513 size_t count, loff_t *offs) 514 { 515 struct task_struct *task = get_proc_task(file_inode(file)); 516 517 if (!task) 518 return -ESRCH; 519 clear_all_latency_tracing(task); 520 put_task_struct(task); 521 522 return count; 523 } 524 525 static const struct file_operations proc_lstats_operations = { 526 .open = lstats_open, 527 .read = seq_read, 528 .write = lstats_write, 529 .llseek = seq_lseek, 530 .release = single_release, 531 }; 532 533 #endif 534 535 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns, 536 struct pid *pid, struct task_struct *task) 537 { 538 unsigned long totalpages = totalram_pages + total_swap_pages; 539 unsigned long points = 0; 540 541 points = oom_badness(task, NULL, NULL, totalpages) * 542 1000 / totalpages; 543 seq_printf(m, "%lu\n", points); 544 545 return 0; 546 } 547 548 struct limit_names { 549 const char *name; 550 const char *unit; 551 }; 552 553 static const struct limit_names lnames[RLIM_NLIMITS] = { 554 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 555 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 556 [RLIMIT_DATA] = {"Max data size", "bytes"}, 557 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 558 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 559 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 560 [RLIMIT_NPROC] = {"Max processes", "processes"}, 561 [RLIMIT_NOFILE] = {"Max open files", "files"}, 562 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 563 [RLIMIT_AS] = {"Max address space", "bytes"}, 564 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 565 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 566 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 567 [RLIMIT_NICE] = {"Max nice priority", NULL}, 568 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 569 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 570 }; 571 572 /* Display limits for a process */ 573 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns, 574 struct pid *pid, struct task_struct *task) 575 { 576 unsigned int i; 577 unsigned long flags; 578 579 struct rlimit rlim[RLIM_NLIMITS]; 580 581 if (!lock_task_sighand(task, &flags)) 582 return 0; 583 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 584 unlock_task_sighand(task, &flags); 585 586 /* 587 * print the file header 588 */ 589 seq_printf(m, "%-25s %-20s %-20s %-10s\n", 590 "Limit", "Soft Limit", "Hard Limit", "Units"); 591 592 for (i = 0; i < RLIM_NLIMITS; i++) { 593 if (rlim[i].rlim_cur == RLIM_INFINITY) 594 seq_printf(m, "%-25s %-20s ", 595 lnames[i].name, "unlimited"); 596 else 597 seq_printf(m, "%-25s %-20lu ", 598 lnames[i].name, rlim[i].rlim_cur); 599 600 if (rlim[i].rlim_max == RLIM_INFINITY) 601 seq_printf(m, "%-20s ", "unlimited"); 602 else 603 seq_printf(m, "%-20lu ", rlim[i].rlim_max); 604 605 if (lnames[i].unit) 606 seq_printf(m, "%-10s\n", lnames[i].unit); 607 else 608 seq_putc(m, '\n'); 609 } 610 611 return 0; 612 } 613 614 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 615 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns, 616 struct pid *pid, struct task_struct *task) 617 { 618 long nr; 619 unsigned long args[6], sp, pc; 620 int res; 621 622 res = lock_trace(task); 623 if (res) 624 return res; 625 626 if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) 627 seq_puts(m, "running\n"); 628 else if (nr < 0) 629 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc); 630 else 631 seq_printf(m, 632 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", 633 nr, 634 args[0], args[1], args[2], args[3], args[4], args[5], 635 sp, pc); 636 unlock_trace(task); 637 638 return 0; 639 } 640 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 641 642 /************************************************************************/ 643 /* Here the fs part begins */ 644 /************************************************************************/ 645 646 /* permission checks */ 647 static int proc_fd_access_allowed(struct inode *inode) 648 { 649 struct task_struct *task; 650 int allowed = 0; 651 /* Allow access to a task's file descriptors if it is us or we 652 * may use ptrace attach to the process and find out that 653 * information. 654 */ 655 task = get_proc_task(inode); 656 if (task) { 657 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 658 put_task_struct(task); 659 } 660 return allowed; 661 } 662 663 int proc_setattr(struct dentry *dentry, struct iattr *attr) 664 { 665 int error; 666 struct inode *inode = d_inode(dentry); 667 668 if (attr->ia_valid & ATTR_MODE) 669 return -EPERM; 670 671 error = setattr_prepare(dentry, attr); 672 if (error) 673 return error; 674 675 setattr_copy(inode, attr); 676 mark_inode_dirty(inode); 677 return 0; 678 } 679 680 /* 681 * May current process learn task's sched/cmdline info (for hide_pid_min=1) 682 * or euid/egid (for hide_pid_min=2)? 683 */ 684 static bool has_pid_permissions(struct pid_namespace *pid, 685 struct task_struct *task, 686 int hide_pid_min) 687 { 688 if (pid->hide_pid < hide_pid_min) 689 return true; 690 if (in_group_p(pid->pid_gid)) 691 return true; 692 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 693 } 694 695 696 static int proc_pid_permission(struct inode *inode, int mask) 697 { 698 struct pid_namespace *pid = inode->i_sb->s_fs_info; 699 struct task_struct *task; 700 bool has_perms; 701 702 task = get_proc_task(inode); 703 if (!task) 704 return -ESRCH; 705 has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS); 706 put_task_struct(task); 707 708 if (!has_perms) { 709 if (pid->hide_pid == HIDEPID_INVISIBLE) { 710 /* 711 * Let's make getdents(), stat(), and open() 712 * consistent with each other. If a process 713 * may not stat() a file, it shouldn't be seen 714 * in procfs at all. 715 */ 716 return -ENOENT; 717 } 718 719 return -EPERM; 720 } 721 return generic_permission(inode, mask); 722 } 723 724 725 726 static const struct inode_operations proc_def_inode_operations = { 727 .setattr = proc_setattr, 728 }; 729 730 static int proc_single_show(struct seq_file *m, void *v) 731 { 732 struct inode *inode = m->private; 733 struct pid_namespace *ns; 734 struct pid *pid; 735 struct task_struct *task; 736 int ret; 737 738 ns = inode->i_sb->s_fs_info; 739 pid = proc_pid(inode); 740 task = get_pid_task(pid, PIDTYPE_PID); 741 if (!task) 742 return -ESRCH; 743 744 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 745 746 put_task_struct(task); 747 return ret; 748 } 749 750 static int proc_single_open(struct inode *inode, struct file *filp) 751 { 752 return single_open(filp, proc_single_show, inode); 753 } 754 755 static const struct file_operations proc_single_file_operations = { 756 .open = proc_single_open, 757 .read = seq_read, 758 .llseek = seq_lseek, 759 .release = single_release, 760 }; 761 762 763 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode) 764 { 765 struct task_struct *task = get_proc_task(inode); 766 struct mm_struct *mm = ERR_PTR(-ESRCH); 767 768 if (task) { 769 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS); 770 put_task_struct(task); 771 772 if (!IS_ERR_OR_NULL(mm)) { 773 /* ensure this mm_struct can't be freed */ 774 mmgrab(mm); 775 /* but do not pin its memory */ 776 mmput(mm); 777 } 778 } 779 780 return mm; 781 } 782 783 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) 784 { 785 struct mm_struct *mm = proc_mem_open(inode, mode); 786 787 if (IS_ERR(mm)) 788 return PTR_ERR(mm); 789 790 file->private_data = mm; 791 return 0; 792 } 793 794 static int mem_open(struct inode *inode, struct file *file) 795 { 796 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH); 797 798 /* OK to pass negative loff_t, we can catch out-of-range */ 799 file->f_mode |= FMODE_UNSIGNED_OFFSET; 800 801 return ret; 802 } 803 804 static ssize_t mem_rw(struct file *file, char __user *buf, 805 size_t count, loff_t *ppos, int write) 806 { 807 struct mm_struct *mm = file->private_data; 808 unsigned long addr = *ppos; 809 ssize_t copied; 810 char *page; 811 unsigned int flags; 812 813 if (!mm) 814 return 0; 815 816 page = (char *)__get_free_page(GFP_TEMPORARY); 817 if (!page) 818 return -ENOMEM; 819 820 copied = 0; 821 if (!mmget_not_zero(mm)) 822 goto free; 823 824 /* Maybe we should limit FOLL_FORCE to actual ptrace users? */ 825 flags = FOLL_FORCE; 826 if (write) 827 flags |= FOLL_WRITE; 828 829 while (count > 0) { 830 int this_len = min_t(int, count, PAGE_SIZE); 831 832 if (write && copy_from_user(page, buf, this_len)) { 833 copied = -EFAULT; 834 break; 835 } 836 837 this_len = access_remote_vm(mm, addr, page, this_len, flags); 838 if (!this_len) { 839 if (!copied) 840 copied = -EIO; 841 break; 842 } 843 844 if (!write && copy_to_user(buf, page, this_len)) { 845 copied = -EFAULT; 846 break; 847 } 848 849 buf += this_len; 850 addr += this_len; 851 copied += this_len; 852 count -= this_len; 853 } 854 *ppos = addr; 855 856 mmput(mm); 857 free: 858 free_page((unsigned long) page); 859 return copied; 860 } 861 862 static ssize_t mem_read(struct file *file, char __user *buf, 863 size_t count, loff_t *ppos) 864 { 865 return mem_rw(file, buf, count, ppos, 0); 866 } 867 868 static ssize_t mem_write(struct file *file, const char __user *buf, 869 size_t count, loff_t *ppos) 870 { 871 return mem_rw(file, (char __user*)buf, count, ppos, 1); 872 } 873 874 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 875 { 876 switch (orig) { 877 case 0: 878 file->f_pos = offset; 879 break; 880 case 1: 881 file->f_pos += offset; 882 break; 883 default: 884 return -EINVAL; 885 } 886 force_successful_syscall_return(); 887 return file->f_pos; 888 } 889 890 static int mem_release(struct inode *inode, struct file *file) 891 { 892 struct mm_struct *mm = file->private_data; 893 if (mm) 894 mmdrop(mm); 895 return 0; 896 } 897 898 static const struct file_operations proc_mem_operations = { 899 .llseek = mem_lseek, 900 .read = mem_read, 901 .write = mem_write, 902 .open = mem_open, 903 .release = mem_release, 904 }; 905 906 static int environ_open(struct inode *inode, struct file *file) 907 { 908 return __mem_open(inode, file, PTRACE_MODE_READ); 909 } 910 911 static ssize_t environ_read(struct file *file, char __user *buf, 912 size_t count, loff_t *ppos) 913 { 914 char *page; 915 unsigned long src = *ppos; 916 int ret = 0; 917 struct mm_struct *mm = file->private_data; 918 unsigned long env_start, env_end; 919 920 /* Ensure the process spawned far enough to have an environment. */ 921 if (!mm || !mm->env_end) 922 return 0; 923 924 page = (char *)__get_free_page(GFP_TEMPORARY); 925 if (!page) 926 return -ENOMEM; 927 928 ret = 0; 929 if (!mmget_not_zero(mm)) 930 goto free; 931 932 down_read(&mm->mmap_sem); 933 env_start = mm->env_start; 934 env_end = mm->env_end; 935 up_read(&mm->mmap_sem); 936 937 while (count > 0) { 938 size_t this_len, max_len; 939 int retval; 940 941 if (src >= (env_end - env_start)) 942 break; 943 944 this_len = env_end - (env_start + src); 945 946 max_len = min_t(size_t, PAGE_SIZE, count); 947 this_len = min(max_len, this_len); 948 949 retval = access_remote_vm(mm, (env_start + src), page, this_len, 0); 950 951 if (retval <= 0) { 952 ret = retval; 953 break; 954 } 955 956 if (copy_to_user(buf, page, retval)) { 957 ret = -EFAULT; 958 break; 959 } 960 961 ret += retval; 962 src += retval; 963 buf += retval; 964 count -= retval; 965 } 966 *ppos = src; 967 mmput(mm); 968 969 free: 970 free_page((unsigned long) page); 971 return ret; 972 } 973 974 static const struct file_operations proc_environ_operations = { 975 .open = environ_open, 976 .read = environ_read, 977 .llseek = generic_file_llseek, 978 .release = mem_release, 979 }; 980 981 static int auxv_open(struct inode *inode, struct file *file) 982 { 983 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS); 984 } 985 986 static ssize_t auxv_read(struct file *file, char __user *buf, 987 size_t count, loff_t *ppos) 988 { 989 struct mm_struct *mm = file->private_data; 990 unsigned int nwords = 0; 991 992 if (!mm) 993 return 0; 994 do { 995 nwords += 2; 996 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 997 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv, 998 nwords * sizeof(mm->saved_auxv[0])); 999 } 1000 1001 static const struct file_operations proc_auxv_operations = { 1002 .open = auxv_open, 1003 .read = auxv_read, 1004 .llseek = generic_file_llseek, 1005 .release = mem_release, 1006 }; 1007 1008 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count, 1009 loff_t *ppos) 1010 { 1011 struct task_struct *task = get_proc_task(file_inode(file)); 1012 char buffer[PROC_NUMBUF]; 1013 int oom_adj = OOM_ADJUST_MIN; 1014 size_t len; 1015 1016 if (!task) 1017 return -ESRCH; 1018 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX) 1019 oom_adj = OOM_ADJUST_MAX; 1020 else 1021 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) / 1022 OOM_SCORE_ADJ_MAX; 1023 put_task_struct(task); 1024 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj); 1025 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1026 } 1027 1028 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy) 1029 { 1030 static DEFINE_MUTEX(oom_adj_mutex); 1031 struct mm_struct *mm = NULL; 1032 struct task_struct *task; 1033 int err = 0; 1034 1035 task = get_proc_task(file_inode(file)); 1036 if (!task) 1037 return -ESRCH; 1038 1039 mutex_lock(&oom_adj_mutex); 1040 if (legacy) { 1041 if (oom_adj < task->signal->oom_score_adj && 1042 !capable(CAP_SYS_RESOURCE)) { 1043 err = -EACCES; 1044 goto err_unlock; 1045 } 1046 /* 1047 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use 1048 * /proc/pid/oom_score_adj instead. 1049 */ 1050 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 1051 current->comm, task_pid_nr(current), task_pid_nr(task), 1052 task_pid_nr(task)); 1053 } else { 1054 if ((short)oom_adj < task->signal->oom_score_adj_min && 1055 !capable(CAP_SYS_RESOURCE)) { 1056 err = -EACCES; 1057 goto err_unlock; 1058 } 1059 } 1060 1061 /* 1062 * Make sure we will check other processes sharing the mm if this is 1063 * not vfrok which wants its own oom_score_adj. 1064 * pin the mm so it doesn't go away and get reused after task_unlock 1065 */ 1066 if (!task->vfork_done) { 1067 struct task_struct *p = find_lock_task_mm(task); 1068 1069 if (p) { 1070 if (atomic_read(&p->mm->mm_users) > 1) { 1071 mm = p->mm; 1072 mmgrab(mm); 1073 } 1074 task_unlock(p); 1075 } 1076 } 1077 1078 task->signal->oom_score_adj = oom_adj; 1079 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1080 task->signal->oom_score_adj_min = (short)oom_adj; 1081 trace_oom_score_adj_update(task); 1082 1083 if (mm) { 1084 struct task_struct *p; 1085 1086 rcu_read_lock(); 1087 for_each_process(p) { 1088 if (same_thread_group(task, p)) 1089 continue; 1090 1091 /* do not touch kernel threads or the global init */ 1092 if (p->flags & PF_KTHREAD || is_global_init(p)) 1093 continue; 1094 1095 task_lock(p); 1096 if (!p->vfork_done && process_shares_mm(p, mm)) { 1097 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", 1098 task_pid_nr(p), p->comm, 1099 p->signal->oom_score_adj, oom_adj, 1100 task_pid_nr(task), task->comm); 1101 p->signal->oom_score_adj = oom_adj; 1102 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1103 p->signal->oom_score_adj_min = (short)oom_adj; 1104 } 1105 task_unlock(p); 1106 } 1107 rcu_read_unlock(); 1108 mmdrop(mm); 1109 } 1110 err_unlock: 1111 mutex_unlock(&oom_adj_mutex); 1112 put_task_struct(task); 1113 return err; 1114 } 1115 1116 /* 1117 * /proc/pid/oom_adj exists solely for backwards compatibility with previous 1118 * kernels. The effective policy is defined by oom_score_adj, which has a 1119 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly. 1120 * Values written to oom_adj are simply mapped linearly to oom_score_adj. 1121 * Processes that become oom disabled via oom_adj will still be oom disabled 1122 * with this implementation. 1123 * 1124 * oom_adj cannot be removed since existing userspace binaries use it. 1125 */ 1126 static ssize_t oom_adj_write(struct file *file, const char __user *buf, 1127 size_t count, loff_t *ppos) 1128 { 1129 char buffer[PROC_NUMBUF]; 1130 int oom_adj; 1131 int err; 1132 1133 memset(buffer, 0, sizeof(buffer)); 1134 if (count > sizeof(buffer) - 1) 1135 count = sizeof(buffer) - 1; 1136 if (copy_from_user(buffer, buf, count)) { 1137 err = -EFAULT; 1138 goto out; 1139 } 1140 1141 err = kstrtoint(strstrip(buffer), 0, &oom_adj); 1142 if (err) 1143 goto out; 1144 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) && 1145 oom_adj != OOM_DISABLE) { 1146 err = -EINVAL; 1147 goto out; 1148 } 1149 1150 /* 1151 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 1152 * value is always attainable. 1153 */ 1154 if (oom_adj == OOM_ADJUST_MAX) 1155 oom_adj = OOM_SCORE_ADJ_MAX; 1156 else 1157 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE; 1158 1159 err = __set_oom_adj(file, oom_adj, true); 1160 out: 1161 return err < 0 ? err : count; 1162 } 1163 1164 static const struct file_operations proc_oom_adj_operations = { 1165 .read = oom_adj_read, 1166 .write = oom_adj_write, 1167 .llseek = generic_file_llseek, 1168 }; 1169 1170 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 1171 size_t count, loff_t *ppos) 1172 { 1173 struct task_struct *task = get_proc_task(file_inode(file)); 1174 char buffer[PROC_NUMBUF]; 1175 short oom_score_adj = OOM_SCORE_ADJ_MIN; 1176 size_t len; 1177 1178 if (!task) 1179 return -ESRCH; 1180 oom_score_adj = task->signal->oom_score_adj; 1181 put_task_struct(task); 1182 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj); 1183 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1184 } 1185 1186 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1187 size_t count, loff_t *ppos) 1188 { 1189 char buffer[PROC_NUMBUF]; 1190 int oom_score_adj; 1191 int err; 1192 1193 memset(buffer, 0, sizeof(buffer)); 1194 if (count > sizeof(buffer) - 1) 1195 count = sizeof(buffer) - 1; 1196 if (copy_from_user(buffer, buf, count)) { 1197 err = -EFAULT; 1198 goto out; 1199 } 1200 1201 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 1202 if (err) 1203 goto out; 1204 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1205 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1206 err = -EINVAL; 1207 goto out; 1208 } 1209 1210 err = __set_oom_adj(file, oom_score_adj, false); 1211 out: 1212 return err < 0 ? err : count; 1213 } 1214 1215 static const struct file_operations proc_oom_score_adj_operations = { 1216 .read = oom_score_adj_read, 1217 .write = oom_score_adj_write, 1218 .llseek = default_llseek, 1219 }; 1220 1221 #ifdef CONFIG_AUDITSYSCALL 1222 #define TMPBUFLEN 11 1223 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1224 size_t count, loff_t *ppos) 1225 { 1226 struct inode * inode = file_inode(file); 1227 struct task_struct *task = get_proc_task(inode); 1228 ssize_t length; 1229 char tmpbuf[TMPBUFLEN]; 1230 1231 if (!task) 1232 return -ESRCH; 1233 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1234 from_kuid(file->f_cred->user_ns, 1235 audit_get_loginuid(task))); 1236 put_task_struct(task); 1237 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1238 } 1239 1240 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1241 size_t count, loff_t *ppos) 1242 { 1243 struct inode * inode = file_inode(file); 1244 uid_t loginuid; 1245 kuid_t kloginuid; 1246 int rv; 1247 1248 rcu_read_lock(); 1249 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1250 rcu_read_unlock(); 1251 return -EPERM; 1252 } 1253 rcu_read_unlock(); 1254 1255 if (*ppos != 0) { 1256 /* No partial writes. */ 1257 return -EINVAL; 1258 } 1259 1260 rv = kstrtou32_from_user(buf, count, 10, &loginuid); 1261 if (rv < 0) 1262 return rv; 1263 1264 /* is userspace tring to explicitly UNSET the loginuid? */ 1265 if (loginuid == AUDIT_UID_UNSET) { 1266 kloginuid = INVALID_UID; 1267 } else { 1268 kloginuid = make_kuid(file->f_cred->user_ns, loginuid); 1269 if (!uid_valid(kloginuid)) 1270 return -EINVAL; 1271 } 1272 1273 rv = audit_set_loginuid(kloginuid); 1274 if (rv < 0) 1275 return rv; 1276 return count; 1277 } 1278 1279 static const struct file_operations proc_loginuid_operations = { 1280 .read = proc_loginuid_read, 1281 .write = proc_loginuid_write, 1282 .llseek = generic_file_llseek, 1283 }; 1284 1285 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1286 size_t count, loff_t *ppos) 1287 { 1288 struct inode * inode = file_inode(file); 1289 struct task_struct *task = get_proc_task(inode); 1290 ssize_t length; 1291 char tmpbuf[TMPBUFLEN]; 1292 1293 if (!task) 1294 return -ESRCH; 1295 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1296 audit_get_sessionid(task)); 1297 put_task_struct(task); 1298 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1299 } 1300 1301 static const struct file_operations proc_sessionid_operations = { 1302 .read = proc_sessionid_read, 1303 .llseek = generic_file_llseek, 1304 }; 1305 #endif 1306 1307 #ifdef CONFIG_FAULT_INJECTION 1308 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1309 size_t count, loff_t *ppos) 1310 { 1311 struct task_struct *task = get_proc_task(file_inode(file)); 1312 char buffer[PROC_NUMBUF]; 1313 size_t len; 1314 int make_it_fail; 1315 1316 if (!task) 1317 return -ESRCH; 1318 make_it_fail = task->make_it_fail; 1319 put_task_struct(task); 1320 1321 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1322 1323 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1324 } 1325 1326 static ssize_t proc_fault_inject_write(struct file * file, 1327 const char __user * buf, size_t count, loff_t *ppos) 1328 { 1329 struct task_struct *task; 1330 char buffer[PROC_NUMBUF]; 1331 int make_it_fail; 1332 int rv; 1333 1334 if (!capable(CAP_SYS_RESOURCE)) 1335 return -EPERM; 1336 memset(buffer, 0, sizeof(buffer)); 1337 if (count > sizeof(buffer) - 1) 1338 count = sizeof(buffer) - 1; 1339 if (copy_from_user(buffer, buf, count)) 1340 return -EFAULT; 1341 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail); 1342 if (rv < 0) 1343 return rv; 1344 if (make_it_fail < 0 || make_it_fail > 1) 1345 return -EINVAL; 1346 1347 task = get_proc_task(file_inode(file)); 1348 if (!task) 1349 return -ESRCH; 1350 task->make_it_fail = make_it_fail; 1351 put_task_struct(task); 1352 1353 return count; 1354 } 1355 1356 static const struct file_operations proc_fault_inject_operations = { 1357 .read = proc_fault_inject_read, 1358 .write = proc_fault_inject_write, 1359 .llseek = generic_file_llseek, 1360 }; 1361 #endif 1362 1363 1364 #ifdef CONFIG_SCHED_DEBUG 1365 /* 1366 * Print out various scheduling related per-task fields: 1367 */ 1368 static int sched_show(struct seq_file *m, void *v) 1369 { 1370 struct inode *inode = m->private; 1371 struct task_struct *p; 1372 1373 p = get_proc_task(inode); 1374 if (!p) 1375 return -ESRCH; 1376 proc_sched_show_task(p, m); 1377 1378 put_task_struct(p); 1379 1380 return 0; 1381 } 1382 1383 static ssize_t 1384 sched_write(struct file *file, const char __user *buf, 1385 size_t count, loff_t *offset) 1386 { 1387 struct inode *inode = file_inode(file); 1388 struct task_struct *p; 1389 1390 p = get_proc_task(inode); 1391 if (!p) 1392 return -ESRCH; 1393 proc_sched_set_task(p); 1394 1395 put_task_struct(p); 1396 1397 return count; 1398 } 1399 1400 static int sched_open(struct inode *inode, struct file *filp) 1401 { 1402 return single_open(filp, sched_show, inode); 1403 } 1404 1405 static const struct file_operations proc_pid_sched_operations = { 1406 .open = sched_open, 1407 .read = seq_read, 1408 .write = sched_write, 1409 .llseek = seq_lseek, 1410 .release = single_release, 1411 }; 1412 1413 #endif 1414 1415 #ifdef CONFIG_SCHED_AUTOGROUP 1416 /* 1417 * Print out autogroup related information: 1418 */ 1419 static int sched_autogroup_show(struct seq_file *m, void *v) 1420 { 1421 struct inode *inode = m->private; 1422 struct task_struct *p; 1423 1424 p = get_proc_task(inode); 1425 if (!p) 1426 return -ESRCH; 1427 proc_sched_autogroup_show_task(p, m); 1428 1429 put_task_struct(p); 1430 1431 return 0; 1432 } 1433 1434 static ssize_t 1435 sched_autogroup_write(struct file *file, const char __user *buf, 1436 size_t count, loff_t *offset) 1437 { 1438 struct inode *inode = file_inode(file); 1439 struct task_struct *p; 1440 char buffer[PROC_NUMBUF]; 1441 int nice; 1442 int err; 1443 1444 memset(buffer, 0, sizeof(buffer)); 1445 if (count > sizeof(buffer) - 1) 1446 count = sizeof(buffer) - 1; 1447 if (copy_from_user(buffer, buf, count)) 1448 return -EFAULT; 1449 1450 err = kstrtoint(strstrip(buffer), 0, &nice); 1451 if (err < 0) 1452 return err; 1453 1454 p = get_proc_task(inode); 1455 if (!p) 1456 return -ESRCH; 1457 1458 err = proc_sched_autogroup_set_nice(p, nice); 1459 if (err) 1460 count = err; 1461 1462 put_task_struct(p); 1463 1464 return count; 1465 } 1466 1467 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1468 { 1469 int ret; 1470 1471 ret = single_open(filp, sched_autogroup_show, NULL); 1472 if (!ret) { 1473 struct seq_file *m = filp->private_data; 1474 1475 m->private = inode; 1476 } 1477 return ret; 1478 } 1479 1480 static const struct file_operations proc_pid_sched_autogroup_operations = { 1481 .open = sched_autogroup_open, 1482 .read = seq_read, 1483 .write = sched_autogroup_write, 1484 .llseek = seq_lseek, 1485 .release = single_release, 1486 }; 1487 1488 #endif /* CONFIG_SCHED_AUTOGROUP */ 1489 1490 static ssize_t comm_write(struct file *file, const char __user *buf, 1491 size_t count, loff_t *offset) 1492 { 1493 struct inode *inode = file_inode(file); 1494 struct task_struct *p; 1495 char buffer[TASK_COMM_LEN]; 1496 const size_t maxlen = sizeof(buffer) - 1; 1497 1498 memset(buffer, 0, sizeof(buffer)); 1499 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count)) 1500 return -EFAULT; 1501 1502 p = get_proc_task(inode); 1503 if (!p) 1504 return -ESRCH; 1505 1506 if (same_thread_group(current, p)) 1507 set_task_comm(p, buffer); 1508 else 1509 count = -EINVAL; 1510 1511 put_task_struct(p); 1512 1513 return count; 1514 } 1515 1516 static int comm_show(struct seq_file *m, void *v) 1517 { 1518 struct inode *inode = m->private; 1519 struct task_struct *p; 1520 1521 p = get_proc_task(inode); 1522 if (!p) 1523 return -ESRCH; 1524 1525 task_lock(p); 1526 seq_printf(m, "%s\n", p->comm); 1527 task_unlock(p); 1528 1529 put_task_struct(p); 1530 1531 return 0; 1532 } 1533 1534 static int comm_open(struct inode *inode, struct file *filp) 1535 { 1536 return single_open(filp, comm_show, inode); 1537 } 1538 1539 static const struct file_operations proc_pid_set_comm_operations = { 1540 .open = comm_open, 1541 .read = seq_read, 1542 .write = comm_write, 1543 .llseek = seq_lseek, 1544 .release = single_release, 1545 }; 1546 1547 static int proc_exe_link(struct dentry *dentry, struct path *exe_path) 1548 { 1549 struct task_struct *task; 1550 struct file *exe_file; 1551 1552 task = get_proc_task(d_inode(dentry)); 1553 if (!task) 1554 return -ENOENT; 1555 exe_file = get_task_exe_file(task); 1556 put_task_struct(task); 1557 if (exe_file) { 1558 *exe_path = exe_file->f_path; 1559 path_get(&exe_file->f_path); 1560 fput(exe_file); 1561 return 0; 1562 } else 1563 return -ENOENT; 1564 } 1565 1566 static const char *proc_pid_get_link(struct dentry *dentry, 1567 struct inode *inode, 1568 struct delayed_call *done) 1569 { 1570 struct path path; 1571 int error = -EACCES; 1572 1573 if (!dentry) 1574 return ERR_PTR(-ECHILD); 1575 1576 /* Are we allowed to snoop on the tasks file descriptors? */ 1577 if (!proc_fd_access_allowed(inode)) 1578 goto out; 1579 1580 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1581 if (error) 1582 goto out; 1583 1584 nd_jump_link(&path); 1585 return NULL; 1586 out: 1587 return ERR_PTR(error); 1588 } 1589 1590 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1591 { 1592 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1593 char *pathname; 1594 int len; 1595 1596 if (!tmp) 1597 return -ENOMEM; 1598 1599 pathname = d_path(path, tmp, PAGE_SIZE); 1600 len = PTR_ERR(pathname); 1601 if (IS_ERR(pathname)) 1602 goto out; 1603 len = tmp + PAGE_SIZE - 1 - pathname; 1604 1605 if (len > buflen) 1606 len = buflen; 1607 if (copy_to_user(buffer, pathname, len)) 1608 len = -EFAULT; 1609 out: 1610 free_page((unsigned long)tmp); 1611 return len; 1612 } 1613 1614 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1615 { 1616 int error = -EACCES; 1617 struct inode *inode = d_inode(dentry); 1618 struct path path; 1619 1620 /* Are we allowed to snoop on the tasks file descriptors? */ 1621 if (!proc_fd_access_allowed(inode)) 1622 goto out; 1623 1624 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1625 if (error) 1626 goto out; 1627 1628 error = do_proc_readlink(&path, buffer, buflen); 1629 path_put(&path); 1630 out: 1631 return error; 1632 } 1633 1634 const struct inode_operations proc_pid_link_inode_operations = { 1635 .readlink = proc_pid_readlink, 1636 .get_link = proc_pid_get_link, 1637 .setattr = proc_setattr, 1638 }; 1639 1640 1641 /* building an inode */ 1642 1643 void task_dump_owner(struct task_struct *task, mode_t mode, 1644 kuid_t *ruid, kgid_t *rgid) 1645 { 1646 /* Depending on the state of dumpable compute who should own a 1647 * proc file for a task. 1648 */ 1649 const struct cred *cred; 1650 kuid_t uid; 1651 kgid_t gid; 1652 1653 /* Default to the tasks effective ownership */ 1654 rcu_read_lock(); 1655 cred = __task_cred(task); 1656 uid = cred->euid; 1657 gid = cred->egid; 1658 rcu_read_unlock(); 1659 1660 /* 1661 * Before the /proc/pid/status file was created the only way to read 1662 * the effective uid of a /process was to stat /proc/pid. Reading 1663 * /proc/pid/status is slow enough that procps and other packages 1664 * kept stating /proc/pid. To keep the rules in /proc simple I have 1665 * made this apply to all per process world readable and executable 1666 * directories. 1667 */ 1668 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) { 1669 struct mm_struct *mm; 1670 task_lock(task); 1671 mm = task->mm; 1672 /* Make non-dumpable tasks owned by some root */ 1673 if (mm) { 1674 if (get_dumpable(mm) != SUID_DUMP_USER) { 1675 struct user_namespace *user_ns = mm->user_ns; 1676 1677 uid = make_kuid(user_ns, 0); 1678 if (!uid_valid(uid)) 1679 uid = GLOBAL_ROOT_UID; 1680 1681 gid = make_kgid(user_ns, 0); 1682 if (!gid_valid(gid)) 1683 gid = GLOBAL_ROOT_GID; 1684 } 1685 } else { 1686 uid = GLOBAL_ROOT_UID; 1687 gid = GLOBAL_ROOT_GID; 1688 } 1689 task_unlock(task); 1690 } 1691 *ruid = uid; 1692 *rgid = gid; 1693 } 1694 1695 struct inode *proc_pid_make_inode(struct super_block * sb, 1696 struct task_struct *task, umode_t mode) 1697 { 1698 struct inode * inode; 1699 struct proc_inode *ei; 1700 1701 /* We need a new inode */ 1702 1703 inode = new_inode(sb); 1704 if (!inode) 1705 goto out; 1706 1707 /* Common stuff */ 1708 ei = PROC_I(inode); 1709 inode->i_mode = mode; 1710 inode->i_ino = get_next_ino(); 1711 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 1712 inode->i_op = &proc_def_inode_operations; 1713 1714 /* 1715 * grab the reference to task. 1716 */ 1717 ei->pid = get_task_pid(task, PIDTYPE_PID); 1718 if (!ei->pid) 1719 goto out_unlock; 1720 1721 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); 1722 security_task_to_inode(task, inode); 1723 1724 out: 1725 return inode; 1726 1727 out_unlock: 1728 iput(inode); 1729 return NULL; 1730 } 1731 1732 int pid_getattr(const struct path *path, struct kstat *stat, 1733 u32 request_mask, unsigned int query_flags) 1734 { 1735 struct inode *inode = d_inode(path->dentry); 1736 struct task_struct *task; 1737 struct pid_namespace *pid = path->dentry->d_sb->s_fs_info; 1738 1739 generic_fillattr(inode, stat); 1740 1741 rcu_read_lock(); 1742 stat->uid = GLOBAL_ROOT_UID; 1743 stat->gid = GLOBAL_ROOT_GID; 1744 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1745 if (task) { 1746 if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) { 1747 rcu_read_unlock(); 1748 /* 1749 * This doesn't prevent learning whether PID exists, 1750 * it only makes getattr() consistent with readdir(). 1751 */ 1752 return -ENOENT; 1753 } 1754 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid); 1755 } 1756 rcu_read_unlock(); 1757 return 0; 1758 } 1759 1760 /* dentry stuff */ 1761 1762 /* 1763 * Exceptional case: normally we are not allowed to unhash a busy 1764 * directory. In this case, however, we can do it - no aliasing problems 1765 * due to the way we treat inodes. 1766 * 1767 * Rewrite the inode's ownerships here because the owning task may have 1768 * performed a setuid(), etc. 1769 * 1770 */ 1771 int pid_revalidate(struct dentry *dentry, unsigned int flags) 1772 { 1773 struct inode *inode; 1774 struct task_struct *task; 1775 1776 if (flags & LOOKUP_RCU) 1777 return -ECHILD; 1778 1779 inode = d_inode(dentry); 1780 task = get_proc_task(inode); 1781 1782 if (task) { 1783 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid); 1784 1785 inode->i_mode &= ~(S_ISUID | S_ISGID); 1786 security_task_to_inode(task, inode); 1787 put_task_struct(task); 1788 return 1; 1789 } 1790 return 0; 1791 } 1792 1793 static inline bool proc_inode_is_dead(struct inode *inode) 1794 { 1795 return !proc_pid(inode)->tasks[PIDTYPE_PID].first; 1796 } 1797 1798 int pid_delete_dentry(const struct dentry *dentry) 1799 { 1800 /* Is the task we represent dead? 1801 * If so, then don't put the dentry on the lru list, 1802 * kill it immediately. 1803 */ 1804 return proc_inode_is_dead(d_inode(dentry)); 1805 } 1806 1807 const struct dentry_operations pid_dentry_operations = 1808 { 1809 .d_revalidate = pid_revalidate, 1810 .d_delete = pid_delete_dentry, 1811 }; 1812 1813 /* Lookups */ 1814 1815 /* 1816 * Fill a directory entry. 1817 * 1818 * If possible create the dcache entry and derive our inode number and 1819 * file type from dcache entry. 1820 * 1821 * Since all of the proc inode numbers are dynamically generated, the inode 1822 * numbers do not exist until the inode is cache. This means creating the 1823 * the dcache entry in readdir is necessary to keep the inode numbers 1824 * reported by readdir in sync with the inode numbers reported 1825 * by stat. 1826 */ 1827 bool proc_fill_cache(struct file *file, struct dir_context *ctx, 1828 const char *name, int len, 1829 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1830 { 1831 struct dentry *child, *dir = file->f_path.dentry; 1832 struct qstr qname = QSTR_INIT(name, len); 1833 struct inode *inode; 1834 unsigned type; 1835 ino_t ino; 1836 1837 child = d_hash_and_lookup(dir, &qname); 1838 if (!child) { 1839 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 1840 child = d_alloc_parallel(dir, &qname, &wq); 1841 if (IS_ERR(child)) 1842 goto end_instantiate; 1843 if (d_in_lookup(child)) { 1844 int err = instantiate(d_inode(dir), child, task, ptr); 1845 d_lookup_done(child); 1846 if (err < 0) { 1847 dput(child); 1848 goto end_instantiate; 1849 } 1850 } 1851 } 1852 inode = d_inode(child); 1853 ino = inode->i_ino; 1854 type = inode->i_mode >> 12; 1855 dput(child); 1856 return dir_emit(ctx, name, len, ino, type); 1857 1858 end_instantiate: 1859 return dir_emit(ctx, name, len, 1, DT_UNKNOWN); 1860 } 1861 1862 /* 1863 * dname_to_vma_addr - maps a dentry name into two unsigned longs 1864 * which represent vma start and end addresses. 1865 */ 1866 static int dname_to_vma_addr(struct dentry *dentry, 1867 unsigned long *start, unsigned long *end) 1868 { 1869 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2) 1870 return -EINVAL; 1871 1872 return 0; 1873 } 1874 1875 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags) 1876 { 1877 unsigned long vm_start, vm_end; 1878 bool exact_vma_exists = false; 1879 struct mm_struct *mm = NULL; 1880 struct task_struct *task; 1881 struct inode *inode; 1882 int status = 0; 1883 1884 if (flags & LOOKUP_RCU) 1885 return -ECHILD; 1886 1887 inode = d_inode(dentry); 1888 task = get_proc_task(inode); 1889 if (!task) 1890 goto out_notask; 1891 1892 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); 1893 if (IS_ERR_OR_NULL(mm)) 1894 goto out; 1895 1896 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 1897 down_read(&mm->mmap_sem); 1898 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end); 1899 up_read(&mm->mmap_sem); 1900 } 1901 1902 mmput(mm); 1903 1904 if (exact_vma_exists) { 1905 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); 1906 1907 security_task_to_inode(task, inode); 1908 status = 1; 1909 } 1910 1911 out: 1912 put_task_struct(task); 1913 1914 out_notask: 1915 return status; 1916 } 1917 1918 static const struct dentry_operations tid_map_files_dentry_operations = { 1919 .d_revalidate = map_files_d_revalidate, 1920 .d_delete = pid_delete_dentry, 1921 }; 1922 1923 static int map_files_get_link(struct dentry *dentry, struct path *path) 1924 { 1925 unsigned long vm_start, vm_end; 1926 struct vm_area_struct *vma; 1927 struct task_struct *task; 1928 struct mm_struct *mm; 1929 int rc; 1930 1931 rc = -ENOENT; 1932 task = get_proc_task(d_inode(dentry)); 1933 if (!task) 1934 goto out; 1935 1936 mm = get_task_mm(task); 1937 put_task_struct(task); 1938 if (!mm) 1939 goto out; 1940 1941 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 1942 if (rc) 1943 goto out_mmput; 1944 1945 rc = -ENOENT; 1946 down_read(&mm->mmap_sem); 1947 vma = find_exact_vma(mm, vm_start, vm_end); 1948 if (vma && vma->vm_file) { 1949 *path = vma->vm_file->f_path; 1950 path_get(path); 1951 rc = 0; 1952 } 1953 up_read(&mm->mmap_sem); 1954 1955 out_mmput: 1956 mmput(mm); 1957 out: 1958 return rc; 1959 } 1960 1961 struct map_files_info { 1962 fmode_t mode; 1963 unsigned int len; 1964 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */ 1965 }; 1966 1967 /* 1968 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the 1969 * symlinks may be used to bypass permissions on ancestor directories in the 1970 * path to the file in question. 1971 */ 1972 static const char * 1973 proc_map_files_get_link(struct dentry *dentry, 1974 struct inode *inode, 1975 struct delayed_call *done) 1976 { 1977 if (!capable(CAP_SYS_ADMIN)) 1978 return ERR_PTR(-EPERM); 1979 1980 return proc_pid_get_link(dentry, inode, done); 1981 } 1982 1983 /* 1984 * Identical to proc_pid_link_inode_operations except for get_link() 1985 */ 1986 static const struct inode_operations proc_map_files_link_inode_operations = { 1987 .readlink = proc_pid_readlink, 1988 .get_link = proc_map_files_get_link, 1989 .setattr = proc_setattr, 1990 }; 1991 1992 static int 1993 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry, 1994 struct task_struct *task, const void *ptr) 1995 { 1996 fmode_t mode = (fmode_t)(unsigned long)ptr; 1997 struct proc_inode *ei; 1998 struct inode *inode; 1999 2000 inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK | 2001 ((mode & FMODE_READ ) ? S_IRUSR : 0) | 2002 ((mode & FMODE_WRITE) ? S_IWUSR : 0)); 2003 if (!inode) 2004 return -ENOENT; 2005 2006 ei = PROC_I(inode); 2007 ei->op.proc_get_link = map_files_get_link; 2008 2009 inode->i_op = &proc_map_files_link_inode_operations; 2010 inode->i_size = 64; 2011 2012 d_set_d_op(dentry, &tid_map_files_dentry_operations); 2013 d_add(dentry, inode); 2014 2015 return 0; 2016 } 2017 2018 static struct dentry *proc_map_files_lookup(struct inode *dir, 2019 struct dentry *dentry, unsigned int flags) 2020 { 2021 unsigned long vm_start, vm_end; 2022 struct vm_area_struct *vma; 2023 struct task_struct *task; 2024 int result; 2025 struct mm_struct *mm; 2026 2027 result = -ENOENT; 2028 task = get_proc_task(dir); 2029 if (!task) 2030 goto out; 2031 2032 result = -EACCES; 2033 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2034 goto out_put_task; 2035 2036 result = -ENOENT; 2037 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 2038 goto out_put_task; 2039 2040 mm = get_task_mm(task); 2041 if (!mm) 2042 goto out_put_task; 2043 2044 down_read(&mm->mmap_sem); 2045 vma = find_exact_vma(mm, vm_start, vm_end); 2046 if (!vma) 2047 goto out_no_vma; 2048 2049 if (vma->vm_file) 2050 result = proc_map_files_instantiate(dir, dentry, task, 2051 (void *)(unsigned long)vma->vm_file->f_mode); 2052 2053 out_no_vma: 2054 up_read(&mm->mmap_sem); 2055 mmput(mm); 2056 out_put_task: 2057 put_task_struct(task); 2058 out: 2059 return ERR_PTR(result); 2060 } 2061 2062 static const struct inode_operations proc_map_files_inode_operations = { 2063 .lookup = proc_map_files_lookup, 2064 .permission = proc_fd_permission, 2065 .setattr = proc_setattr, 2066 }; 2067 2068 static int 2069 proc_map_files_readdir(struct file *file, struct dir_context *ctx) 2070 { 2071 struct vm_area_struct *vma; 2072 struct task_struct *task; 2073 struct mm_struct *mm; 2074 unsigned long nr_files, pos, i; 2075 struct flex_array *fa = NULL; 2076 struct map_files_info info; 2077 struct map_files_info *p; 2078 int ret; 2079 2080 ret = -ENOENT; 2081 task = get_proc_task(file_inode(file)); 2082 if (!task) 2083 goto out; 2084 2085 ret = -EACCES; 2086 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2087 goto out_put_task; 2088 2089 ret = 0; 2090 if (!dir_emit_dots(file, ctx)) 2091 goto out_put_task; 2092 2093 mm = get_task_mm(task); 2094 if (!mm) 2095 goto out_put_task; 2096 down_read(&mm->mmap_sem); 2097 2098 nr_files = 0; 2099 2100 /* 2101 * We need two passes here: 2102 * 2103 * 1) Collect vmas of mapped files with mmap_sem taken 2104 * 2) Release mmap_sem and instantiate entries 2105 * 2106 * otherwise we get lockdep complained, since filldir() 2107 * routine might require mmap_sem taken in might_fault(). 2108 */ 2109 2110 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 2111 if (vma->vm_file && ++pos > ctx->pos) 2112 nr_files++; 2113 } 2114 2115 if (nr_files) { 2116 fa = flex_array_alloc(sizeof(info), nr_files, 2117 GFP_KERNEL); 2118 if (!fa || flex_array_prealloc(fa, 0, nr_files, 2119 GFP_KERNEL)) { 2120 ret = -ENOMEM; 2121 if (fa) 2122 flex_array_free(fa); 2123 up_read(&mm->mmap_sem); 2124 mmput(mm); 2125 goto out_put_task; 2126 } 2127 for (i = 0, vma = mm->mmap, pos = 2; vma; 2128 vma = vma->vm_next) { 2129 if (!vma->vm_file) 2130 continue; 2131 if (++pos <= ctx->pos) 2132 continue; 2133 2134 info.mode = vma->vm_file->f_mode; 2135 info.len = snprintf(info.name, 2136 sizeof(info.name), "%lx-%lx", 2137 vma->vm_start, vma->vm_end); 2138 if (flex_array_put(fa, i++, &info, GFP_KERNEL)) 2139 BUG(); 2140 } 2141 } 2142 up_read(&mm->mmap_sem); 2143 2144 for (i = 0; i < nr_files; i++) { 2145 p = flex_array_get(fa, i); 2146 if (!proc_fill_cache(file, ctx, 2147 p->name, p->len, 2148 proc_map_files_instantiate, 2149 task, 2150 (void *)(unsigned long)p->mode)) 2151 break; 2152 ctx->pos++; 2153 } 2154 if (fa) 2155 flex_array_free(fa); 2156 mmput(mm); 2157 2158 out_put_task: 2159 put_task_struct(task); 2160 out: 2161 return ret; 2162 } 2163 2164 static const struct file_operations proc_map_files_operations = { 2165 .read = generic_read_dir, 2166 .iterate_shared = proc_map_files_readdir, 2167 .llseek = generic_file_llseek, 2168 }; 2169 2170 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS) 2171 struct timers_private { 2172 struct pid *pid; 2173 struct task_struct *task; 2174 struct sighand_struct *sighand; 2175 struct pid_namespace *ns; 2176 unsigned long flags; 2177 }; 2178 2179 static void *timers_start(struct seq_file *m, loff_t *pos) 2180 { 2181 struct timers_private *tp = m->private; 2182 2183 tp->task = get_pid_task(tp->pid, PIDTYPE_PID); 2184 if (!tp->task) 2185 return ERR_PTR(-ESRCH); 2186 2187 tp->sighand = lock_task_sighand(tp->task, &tp->flags); 2188 if (!tp->sighand) 2189 return ERR_PTR(-ESRCH); 2190 2191 return seq_list_start(&tp->task->signal->posix_timers, *pos); 2192 } 2193 2194 static void *timers_next(struct seq_file *m, void *v, loff_t *pos) 2195 { 2196 struct timers_private *tp = m->private; 2197 return seq_list_next(v, &tp->task->signal->posix_timers, pos); 2198 } 2199 2200 static void timers_stop(struct seq_file *m, void *v) 2201 { 2202 struct timers_private *tp = m->private; 2203 2204 if (tp->sighand) { 2205 unlock_task_sighand(tp->task, &tp->flags); 2206 tp->sighand = NULL; 2207 } 2208 2209 if (tp->task) { 2210 put_task_struct(tp->task); 2211 tp->task = NULL; 2212 } 2213 } 2214 2215 static int show_timer(struct seq_file *m, void *v) 2216 { 2217 struct k_itimer *timer; 2218 struct timers_private *tp = m->private; 2219 int notify; 2220 static const char * const nstr[] = { 2221 [SIGEV_SIGNAL] = "signal", 2222 [SIGEV_NONE] = "none", 2223 [SIGEV_THREAD] = "thread", 2224 }; 2225 2226 timer = list_entry((struct list_head *)v, struct k_itimer, list); 2227 notify = timer->it_sigev_notify; 2228 2229 seq_printf(m, "ID: %d\n", timer->it_id); 2230 seq_printf(m, "signal: %d/%p\n", 2231 timer->sigq->info.si_signo, 2232 timer->sigq->info.si_value.sival_ptr); 2233 seq_printf(m, "notify: %s/%s.%d\n", 2234 nstr[notify & ~SIGEV_THREAD_ID], 2235 (notify & SIGEV_THREAD_ID) ? "tid" : "pid", 2236 pid_nr_ns(timer->it_pid, tp->ns)); 2237 seq_printf(m, "ClockID: %d\n", timer->it_clock); 2238 2239 return 0; 2240 } 2241 2242 static const struct seq_operations proc_timers_seq_ops = { 2243 .start = timers_start, 2244 .next = timers_next, 2245 .stop = timers_stop, 2246 .show = show_timer, 2247 }; 2248 2249 static int proc_timers_open(struct inode *inode, struct file *file) 2250 { 2251 struct timers_private *tp; 2252 2253 tp = __seq_open_private(file, &proc_timers_seq_ops, 2254 sizeof(struct timers_private)); 2255 if (!tp) 2256 return -ENOMEM; 2257 2258 tp->pid = proc_pid(inode); 2259 tp->ns = inode->i_sb->s_fs_info; 2260 return 0; 2261 } 2262 2263 static const struct file_operations proc_timers_operations = { 2264 .open = proc_timers_open, 2265 .read = seq_read, 2266 .llseek = seq_lseek, 2267 .release = seq_release_private, 2268 }; 2269 #endif 2270 2271 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf, 2272 size_t count, loff_t *offset) 2273 { 2274 struct inode *inode = file_inode(file); 2275 struct task_struct *p; 2276 u64 slack_ns; 2277 int err; 2278 2279 err = kstrtoull_from_user(buf, count, 10, &slack_ns); 2280 if (err < 0) 2281 return err; 2282 2283 p = get_proc_task(inode); 2284 if (!p) 2285 return -ESRCH; 2286 2287 if (p != current) { 2288 if (!capable(CAP_SYS_NICE)) { 2289 count = -EPERM; 2290 goto out; 2291 } 2292 2293 err = security_task_setscheduler(p); 2294 if (err) { 2295 count = err; 2296 goto out; 2297 } 2298 } 2299 2300 task_lock(p); 2301 if (slack_ns == 0) 2302 p->timer_slack_ns = p->default_timer_slack_ns; 2303 else 2304 p->timer_slack_ns = slack_ns; 2305 task_unlock(p); 2306 2307 out: 2308 put_task_struct(p); 2309 2310 return count; 2311 } 2312 2313 static int timerslack_ns_show(struct seq_file *m, void *v) 2314 { 2315 struct inode *inode = m->private; 2316 struct task_struct *p; 2317 int err = 0; 2318 2319 p = get_proc_task(inode); 2320 if (!p) 2321 return -ESRCH; 2322 2323 if (p != current) { 2324 2325 if (!capable(CAP_SYS_NICE)) { 2326 err = -EPERM; 2327 goto out; 2328 } 2329 err = security_task_getscheduler(p); 2330 if (err) 2331 goto out; 2332 } 2333 2334 task_lock(p); 2335 seq_printf(m, "%llu\n", p->timer_slack_ns); 2336 task_unlock(p); 2337 2338 out: 2339 put_task_struct(p); 2340 2341 return err; 2342 } 2343 2344 static int timerslack_ns_open(struct inode *inode, struct file *filp) 2345 { 2346 return single_open(filp, timerslack_ns_show, inode); 2347 } 2348 2349 static const struct file_operations proc_pid_set_timerslack_ns_operations = { 2350 .open = timerslack_ns_open, 2351 .read = seq_read, 2352 .write = timerslack_ns_write, 2353 .llseek = seq_lseek, 2354 .release = single_release, 2355 }; 2356 2357 static int proc_pident_instantiate(struct inode *dir, 2358 struct dentry *dentry, struct task_struct *task, const void *ptr) 2359 { 2360 const struct pid_entry *p = ptr; 2361 struct inode *inode; 2362 struct proc_inode *ei; 2363 2364 inode = proc_pid_make_inode(dir->i_sb, task, p->mode); 2365 if (!inode) 2366 goto out; 2367 2368 ei = PROC_I(inode); 2369 if (S_ISDIR(inode->i_mode)) 2370 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2371 if (p->iop) 2372 inode->i_op = p->iop; 2373 if (p->fop) 2374 inode->i_fop = p->fop; 2375 ei->op = p->op; 2376 d_set_d_op(dentry, &pid_dentry_operations); 2377 d_add(dentry, inode); 2378 /* Close the race of the process dying before we return the dentry */ 2379 if (pid_revalidate(dentry, 0)) 2380 return 0; 2381 out: 2382 return -ENOENT; 2383 } 2384 2385 static struct dentry *proc_pident_lookup(struct inode *dir, 2386 struct dentry *dentry, 2387 const struct pid_entry *ents, 2388 unsigned int nents) 2389 { 2390 int error; 2391 struct task_struct *task = get_proc_task(dir); 2392 const struct pid_entry *p, *last; 2393 2394 error = -ENOENT; 2395 2396 if (!task) 2397 goto out_no_task; 2398 2399 /* 2400 * Yes, it does not scale. And it should not. Don't add 2401 * new entries into /proc/<tgid>/ without very good reasons. 2402 */ 2403 last = &ents[nents]; 2404 for (p = ents; p < last; p++) { 2405 if (p->len != dentry->d_name.len) 2406 continue; 2407 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2408 break; 2409 } 2410 if (p >= last) 2411 goto out; 2412 2413 error = proc_pident_instantiate(dir, dentry, task, p); 2414 out: 2415 put_task_struct(task); 2416 out_no_task: 2417 return ERR_PTR(error); 2418 } 2419 2420 static int proc_pident_readdir(struct file *file, struct dir_context *ctx, 2421 const struct pid_entry *ents, unsigned int nents) 2422 { 2423 struct task_struct *task = get_proc_task(file_inode(file)); 2424 const struct pid_entry *p; 2425 2426 if (!task) 2427 return -ENOENT; 2428 2429 if (!dir_emit_dots(file, ctx)) 2430 goto out; 2431 2432 if (ctx->pos >= nents + 2) 2433 goto out; 2434 2435 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) { 2436 if (!proc_fill_cache(file, ctx, p->name, p->len, 2437 proc_pident_instantiate, task, p)) 2438 break; 2439 ctx->pos++; 2440 } 2441 out: 2442 put_task_struct(task); 2443 return 0; 2444 } 2445 2446 #ifdef CONFIG_SECURITY 2447 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2448 size_t count, loff_t *ppos) 2449 { 2450 struct inode * inode = file_inode(file); 2451 char *p = NULL; 2452 ssize_t length; 2453 struct task_struct *task = get_proc_task(inode); 2454 2455 if (!task) 2456 return -ESRCH; 2457 2458 length = security_getprocattr(task, 2459 (char*)file->f_path.dentry->d_name.name, 2460 &p); 2461 put_task_struct(task); 2462 if (length > 0) 2463 length = simple_read_from_buffer(buf, count, ppos, p, length); 2464 kfree(p); 2465 return length; 2466 } 2467 2468 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2469 size_t count, loff_t *ppos) 2470 { 2471 struct inode * inode = file_inode(file); 2472 void *page; 2473 ssize_t length; 2474 struct task_struct *task = get_proc_task(inode); 2475 2476 length = -ESRCH; 2477 if (!task) 2478 goto out_no_task; 2479 2480 /* A task may only write its own attributes. */ 2481 length = -EACCES; 2482 if (current != task) 2483 goto out; 2484 2485 if (count > PAGE_SIZE) 2486 count = PAGE_SIZE; 2487 2488 /* No partial writes. */ 2489 length = -EINVAL; 2490 if (*ppos != 0) 2491 goto out; 2492 2493 page = memdup_user(buf, count); 2494 if (IS_ERR(page)) { 2495 length = PTR_ERR(page); 2496 goto out; 2497 } 2498 2499 /* Guard against adverse ptrace interaction */ 2500 length = mutex_lock_interruptible(¤t->signal->cred_guard_mutex); 2501 if (length < 0) 2502 goto out_free; 2503 2504 length = security_setprocattr(file->f_path.dentry->d_name.name, 2505 page, count); 2506 mutex_unlock(¤t->signal->cred_guard_mutex); 2507 out_free: 2508 kfree(page); 2509 out: 2510 put_task_struct(task); 2511 out_no_task: 2512 return length; 2513 } 2514 2515 static const struct file_operations proc_pid_attr_operations = { 2516 .read = proc_pid_attr_read, 2517 .write = proc_pid_attr_write, 2518 .llseek = generic_file_llseek, 2519 }; 2520 2521 static const struct pid_entry attr_dir_stuff[] = { 2522 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2523 REG("prev", S_IRUGO, proc_pid_attr_operations), 2524 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2525 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2526 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2527 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2528 }; 2529 2530 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx) 2531 { 2532 return proc_pident_readdir(file, ctx, 2533 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2534 } 2535 2536 static const struct file_operations proc_attr_dir_operations = { 2537 .read = generic_read_dir, 2538 .iterate_shared = proc_attr_dir_readdir, 2539 .llseek = generic_file_llseek, 2540 }; 2541 2542 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2543 struct dentry *dentry, unsigned int flags) 2544 { 2545 return proc_pident_lookup(dir, dentry, 2546 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2547 } 2548 2549 static const struct inode_operations proc_attr_dir_inode_operations = { 2550 .lookup = proc_attr_dir_lookup, 2551 .getattr = pid_getattr, 2552 .setattr = proc_setattr, 2553 }; 2554 2555 #endif 2556 2557 #ifdef CONFIG_ELF_CORE 2558 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2559 size_t count, loff_t *ppos) 2560 { 2561 struct task_struct *task = get_proc_task(file_inode(file)); 2562 struct mm_struct *mm; 2563 char buffer[PROC_NUMBUF]; 2564 size_t len; 2565 int ret; 2566 2567 if (!task) 2568 return -ESRCH; 2569 2570 ret = 0; 2571 mm = get_task_mm(task); 2572 if (mm) { 2573 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2574 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2575 MMF_DUMP_FILTER_SHIFT)); 2576 mmput(mm); 2577 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2578 } 2579 2580 put_task_struct(task); 2581 2582 return ret; 2583 } 2584 2585 static ssize_t proc_coredump_filter_write(struct file *file, 2586 const char __user *buf, 2587 size_t count, 2588 loff_t *ppos) 2589 { 2590 struct task_struct *task; 2591 struct mm_struct *mm; 2592 unsigned int val; 2593 int ret; 2594 int i; 2595 unsigned long mask; 2596 2597 ret = kstrtouint_from_user(buf, count, 0, &val); 2598 if (ret < 0) 2599 return ret; 2600 2601 ret = -ESRCH; 2602 task = get_proc_task(file_inode(file)); 2603 if (!task) 2604 goto out_no_task; 2605 2606 mm = get_task_mm(task); 2607 if (!mm) 2608 goto out_no_mm; 2609 ret = 0; 2610 2611 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2612 if (val & mask) 2613 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2614 else 2615 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2616 } 2617 2618 mmput(mm); 2619 out_no_mm: 2620 put_task_struct(task); 2621 out_no_task: 2622 if (ret < 0) 2623 return ret; 2624 return count; 2625 } 2626 2627 static const struct file_operations proc_coredump_filter_operations = { 2628 .read = proc_coredump_filter_read, 2629 .write = proc_coredump_filter_write, 2630 .llseek = generic_file_llseek, 2631 }; 2632 #endif 2633 2634 #ifdef CONFIG_TASK_IO_ACCOUNTING 2635 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole) 2636 { 2637 struct task_io_accounting acct = task->ioac; 2638 unsigned long flags; 2639 int result; 2640 2641 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2642 if (result) 2643 return result; 2644 2645 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { 2646 result = -EACCES; 2647 goto out_unlock; 2648 } 2649 2650 if (whole && lock_task_sighand(task, &flags)) { 2651 struct task_struct *t = task; 2652 2653 task_io_accounting_add(&acct, &task->signal->ioac); 2654 while_each_thread(task, t) 2655 task_io_accounting_add(&acct, &t->ioac); 2656 2657 unlock_task_sighand(task, &flags); 2658 } 2659 seq_printf(m, 2660 "rchar: %llu\n" 2661 "wchar: %llu\n" 2662 "syscr: %llu\n" 2663 "syscw: %llu\n" 2664 "read_bytes: %llu\n" 2665 "write_bytes: %llu\n" 2666 "cancelled_write_bytes: %llu\n", 2667 (unsigned long long)acct.rchar, 2668 (unsigned long long)acct.wchar, 2669 (unsigned long long)acct.syscr, 2670 (unsigned long long)acct.syscw, 2671 (unsigned long long)acct.read_bytes, 2672 (unsigned long long)acct.write_bytes, 2673 (unsigned long long)acct.cancelled_write_bytes); 2674 result = 0; 2675 2676 out_unlock: 2677 mutex_unlock(&task->signal->cred_guard_mutex); 2678 return result; 2679 } 2680 2681 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2682 struct pid *pid, struct task_struct *task) 2683 { 2684 return do_io_accounting(task, m, 0); 2685 } 2686 2687 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2688 struct pid *pid, struct task_struct *task) 2689 { 2690 return do_io_accounting(task, m, 1); 2691 } 2692 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2693 2694 #ifdef CONFIG_USER_NS 2695 static int proc_id_map_open(struct inode *inode, struct file *file, 2696 const struct seq_operations *seq_ops) 2697 { 2698 struct user_namespace *ns = NULL; 2699 struct task_struct *task; 2700 struct seq_file *seq; 2701 int ret = -EINVAL; 2702 2703 task = get_proc_task(inode); 2704 if (task) { 2705 rcu_read_lock(); 2706 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2707 rcu_read_unlock(); 2708 put_task_struct(task); 2709 } 2710 if (!ns) 2711 goto err; 2712 2713 ret = seq_open(file, seq_ops); 2714 if (ret) 2715 goto err_put_ns; 2716 2717 seq = file->private_data; 2718 seq->private = ns; 2719 2720 return 0; 2721 err_put_ns: 2722 put_user_ns(ns); 2723 err: 2724 return ret; 2725 } 2726 2727 static int proc_id_map_release(struct inode *inode, struct file *file) 2728 { 2729 struct seq_file *seq = file->private_data; 2730 struct user_namespace *ns = seq->private; 2731 put_user_ns(ns); 2732 return seq_release(inode, file); 2733 } 2734 2735 static int proc_uid_map_open(struct inode *inode, struct file *file) 2736 { 2737 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2738 } 2739 2740 static int proc_gid_map_open(struct inode *inode, struct file *file) 2741 { 2742 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2743 } 2744 2745 static int proc_projid_map_open(struct inode *inode, struct file *file) 2746 { 2747 return proc_id_map_open(inode, file, &proc_projid_seq_operations); 2748 } 2749 2750 static const struct file_operations proc_uid_map_operations = { 2751 .open = proc_uid_map_open, 2752 .write = proc_uid_map_write, 2753 .read = seq_read, 2754 .llseek = seq_lseek, 2755 .release = proc_id_map_release, 2756 }; 2757 2758 static const struct file_operations proc_gid_map_operations = { 2759 .open = proc_gid_map_open, 2760 .write = proc_gid_map_write, 2761 .read = seq_read, 2762 .llseek = seq_lseek, 2763 .release = proc_id_map_release, 2764 }; 2765 2766 static const struct file_operations proc_projid_map_operations = { 2767 .open = proc_projid_map_open, 2768 .write = proc_projid_map_write, 2769 .read = seq_read, 2770 .llseek = seq_lseek, 2771 .release = proc_id_map_release, 2772 }; 2773 2774 static int proc_setgroups_open(struct inode *inode, struct file *file) 2775 { 2776 struct user_namespace *ns = NULL; 2777 struct task_struct *task; 2778 int ret; 2779 2780 ret = -ESRCH; 2781 task = get_proc_task(inode); 2782 if (task) { 2783 rcu_read_lock(); 2784 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2785 rcu_read_unlock(); 2786 put_task_struct(task); 2787 } 2788 if (!ns) 2789 goto err; 2790 2791 if (file->f_mode & FMODE_WRITE) { 2792 ret = -EACCES; 2793 if (!ns_capable(ns, CAP_SYS_ADMIN)) 2794 goto err_put_ns; 2795 } 2796 2797 ret = single_open(file, &proc_setgroups_show, ns); 2798 if (ret) 2799 goto err_put_ns; 2800 2801 return 0; 2802 err_put_ns: 2803 put_user_ns(ns); 2804 err: 2805 return ret; 2806 } 2807 2808 static int proc_setgroups_release(struct inode *inode, struct file *file) 2809 { 2810 struct seq_file *seq = file->private_data; 2811 struct user_namespace *ns = seq->private; 2812 int ret = single_release(inode, file); 2813 put_user_ns(ns); 2814 return ret; 2815 } 2816 2817 static const struct file_operations proc_setgroups_operations = { 2818 .open = proc_setgroups_open, 2819 .write = proc_setgroups_write, 2820 .read = seq_read, 2821 .llseek = seq_lseek, 2822 .release = proc_setgroups_release, 2823 }; 2824 #endif /* CONFIG_USER_NS */ 2825 2826 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2827 struct pid *pid, struct task_struct *task) 2828 { 2829 int err = lock_trace(task); 2830 if (!err) { 2831 seq_printf(m, "%08x\n", task->personality); 2832 unlock_trace(task); 2833 } 2834 return err; 2835 } 2836 2837 /* 2838 * Thread groups 2839 */ 2840 static const struct file_operations proc_task_operations; 2841 static const struct inode_operations proc_task_inode_operations; 2842 2843 static const struct pid_entry tgid_base_stuff[] = { 2844 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2845 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2846 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 2847 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2848 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2849 #ifdef CONFIG_NET 2850 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2851 #endif 2852 REG("environ", S_IRUSR, proc_environ_operations), 2853 REG("auxv", S_IRUSR, proc_auxv_operations), 2854 ONE("status", S_IRUGO, proc_pid_status), 2855 ONE("personality", S_IRUSR, proc_pid_personality), 2856 ONE("limits", S_IRUGO, proc_pid_limits), 2857 #ifdef CONFIG_SCHED_DEBUG 2858 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2859 #endif 2860 #ifdef CONFIG_SCHED_AUTOGROUP 2861 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2862 #endif 2863 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2864 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2865 ONE("syscall", S_IRUSR, proc_pid_syscall), 2866 #endif 2867 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 2868 ONE("stat", S_IRUGO, proc_tgid_stat), 2869 ONE("statm", S_IRUGO, proc_pid_statm), 2870 REG("maps", S_IRUGO, proc_pid_maps_operations), 2871 #ifdef CONFIG_NUMA 2872 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 2873 #endif 2874 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2875 LNK("cwd", proc_cwd_link), 2876 LNK("root", proc_root_link), 2877 LNK("exe", proc_exe_link), 2878 REG("mounts", S_IRUGO, proc_mounts_operations), 2879 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2880 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2881 #ifdef CONFIG_PROC_PAGE_MONITOR 2882 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2883 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 2884 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2885 #endif 2886 #ifdef CONFIG_SECURITY 2887 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2888 #endif 2889 #ifdef CONFIG_KALLSYMS 2890 ONE("wchan", S_IRUGO, proc_pid_wchan), 2891 #endif 2892 #ifdef CONFIG_STACKTRACE 2893 ONE("stack", S_IRUSR, proc_pid_stack), 2894 #endif 2895 #ifdef CONFIG_SCHED_INFO 2896 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 2897 #endif 2898 #ifdef CONFIG_LATENCYTOP 2899 REG("latency", S_IRUGO, proc_lstats_operations), 2900 #endif 2901 #ifdef CONFIG_PROC_PID_CPUSET 2902 ONE("cpuset", S_IRUGO, proc_cpuset_show), 2903 #endif 2904 #ifdef CONFIG_CGROUPS 2905 ONE("cgroup", S_IRUGO, proc_cgroup_show), 2906 #endif 2907 ONE("oom_score", S_IRUGO, proc_oom_score), 2908 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 2909 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2910 #ifdef CONFIG_AUDITSYSCALL 2911 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2912 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2913 #endif 2914 #ifdef CONFIG_FAULT_INJECTION 2915 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2916 #endif 2917 #ifdef CONFIG_ELF_CORE 2918 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2919 #endif 2920 #ifdef CONFIG_TASK_IO_ACCOUNTING 2921 ONE("io", S_IRUSR, proc_tgid_io_accounting), 2922 #endif 2923 #ifdef CONFIG_HARDWALL 2924 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 2925 #endif 2926 #ifdef CONFIG_USER_NS 2927 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 2928 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 2929 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 2930 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 2931 #endif 2932 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS) 2933 REG("timers", S_IRUGO, proc_timers_operations), 2934 #endif 2935 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations), 2936 }; 2937 2938 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) 2939 { 2940 return proc_pident_readdir(file, ctx, 2941 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2942 } 2943 2944 static const struct file_operations proc_tgid_base_operations = { 2945 .read = generic_read_dir, 2946 .iterate_shared = proc_tgid_base_readdir, 2947 .llseek = generic_file_llseek, 2948 }; 2949 2950 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 2951 { 2952 return proc_pident_lookup(dir, dentry, 2953 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2954 } 2955 2956 static const struct inode_operations proc_tgid_base_inode_operations = { 2957 .lookup = proc_tgid_base_lookup, 2958 .getattr = pid_getattr, 2959 .setattr = proc_setattr, 2960 .permission = proc_pid_permission, 2961 }; 2962 2963 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2964 { 2965 struct dentry *dentry, *leader, *dir; 2966 char buf[PROC_NUMBUF]; 2967 struct qstr name; 2968 2969 name.name = buf; 2970 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2971 /* no ->d_hash() rejects on procfs */ 2972 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2973 if (dentry) { 2974 d_invalidate(dentry); 2975 dput(dentry); 2976 } 2977 2978 if (pid == tgid) 2979 return; 2980 2981 name.name = buf; 2982 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2983 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2984 if (!leader) 2985 goto out; 2986 2987 name.name = "task"; 2988 name.len = strlen(name.name); 2989 dir = d_hash_and_lookup(leader, &name); 2990 if (!dir) 2991 goto out_put_leader; 2992 2993 name.name = buf; 2994 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2995 dentry = d_hash_and_lookup(dir, &name); 2996 if (dentry) { 2997 d_invalidate(dentry); 2998 dput(dentry); 2999 } 3000 3001 dput(dir); 3002 out_put_leader: 3003 dput(leader); 3004 out: 3005 return; 3006 } 3007 3008 /** 3009 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 3010 * @task: task that should be flushed. 3011 * 3012 * When flushing dentries from proc, one needs to flush them from global 3013 * proc (proc_mnt) and from all the namespaces' procs this task was seen 3014 * in. This call is supposed to do all of this job. 3015 * 3016 * Looks in the dcache for 3017 * /proc/@pid 3018 * /proc/@tgid/task/@pid 3019 * if either directory is present flushes it and all of it'ts children 3020 * from the dcache. 3021 * 3022 * It is safe and reasonable to cache /proc entries for a task until 3023 * that task exits. After that they just clog up the dcache with 3024 * useless entries, possibly causing useful dcache entries to be 3025 * flushed instead. This routine is proved to flush those useless 3026 * dcache entries at process exit time. 3027 * 3028 * NOTE: This routine is just an optimization so it does not guarantee 3029 * that no dcache entries will exist at process exit time it 3030 * just makes it very unlikely that any will persist. 3031 */ 3032 3033 void proc_flush_task(struct task_struct *task) 3034 { 3035 int i; 3036 struct pid *pid, *tgid; 3037 struct upid *upid; 3038 3039 pid = task_pid(task); 3040 tgid = task_tgid(task); 3041 3042 for (i = 0; i <= pid->level; i++) { 3043 upid = &pid->numbers[i]; 3044 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3045 tgid->numbers[i].nr); 3046 } 3047 } 3048 3049 static int proc_pid_instantiate(struct inode *dir, 3050 struct dentry * dentry, 3051 struct task_struct *task, const void *ptr) 3052 { 3053 struct inode *inode; 3054 3055 inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3056 if (!inode) 3057 goto out; 3058 3059 inode->i_op = &proc_tgid_base_inode_operations; 3060 inode->i_fop = &proc_tgid_base_operations; 3061 inode->i_flags|=S_IMMUTABLE; 3062 3063 set_nlink(inode, nlink_tgid); 3064 3065 d_set_d_op(dentry, &pid_dentry_operations); 3066 3067 d_add(dentry, inode); 3068 /* Close the race of the process dying before we return the dentry */ 3069 if (pid_revalidate(dentry, 0)) 3070 return 0; 3071 out: 3072 return -ENOENT; 3073 } 3074 3075 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3076 { 3077 int result = -ENOENT; 3078 struct task_struct *task; 3079 unsigned tgid; 3080 struct pid_namespace *ns; 3081 3082 tgid = name_to_int(&dentry->d_name); 3083 if (tgid == ~0U) 3084 goto out; 3085 3086 ns = dentry->d_sb->s_fs_info; 3087 rcu_read_lock(); 3088 task = find_task_by_pid_ns(tgid, ns); 3089 if (task) 3090 get_task_struct(task); 3091 rcu_read_unlock(); 3092 if (!task) 3093 goto out; 3094 3095 result = proc_pid_instantiate(dir, dentry, task, NULL); 3096 put_task_struct(task); 3097 out: 3098 return ERR_PTR(result); 3099 } 3100 3101 /* 3102 * Find the first task with tgid >= tgid 3103 * 3104 */ 3105 struct tgid_iter { 3106 unsigned int tgid; 3107 struct task_struct *task; 3108 }; 3109 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3110 { 3111 struct pid *pid; 3112 3113 if (iter.task) 3114 put_task_struct(iter.task); 3115 rcu_read_lock(); 3116 retry: 3117 iter.task = NULL; 3118 pid = find_ge_pid(iter.tgid, ns); 3119 if (pid) { 3120 iter.tgid = pid_nr_ns(pid, ns); 3121 iter.task = pid_task(pid, PIDTYPE_PID); 3122 /* What we to know is if the pid we have find is the 3123 * pid of a thread_group_leader. Testing for task 3124 * being a thread_group_leader is the obvious thing 3125 * todo but there is a window when it fails, due to 3126 * the pid transfer logic in de_thread. 3127 * 3128 * So we perform the straight forward test of seeing 3129 * if the pid we have found is the pid of a thread 3130 * group leader, and don't worry if the task we have 3131 * found doesn't happen to be a thread group leader. 3132 * As we don't care in the case of readdir. 3133 */ 3134 if (!iter.task || !has_group_leader_pid(iter.task)) { 3135 iter.tgid += 1; 3136 goto retry; 3137 } 3138 get_task_struct(iter.task); 3139 } 3140 rcu_read_unlock(); 3141 return iter; 3142 } 3143 3144 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2) 3145 3146 /* for the /proc/ directory itself, after non-process stuff has been done */ 3147 int proc_pid_readdir(struct file *file, struct dir_context *ctx) 3148 { 3149 struct tgid_iter iter; 3150 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info; 3151 loff_t pos = ctx->pos; 3152 3153 if (pos >= PID_MAX_LIMIT + TGID_OFFSET) 3154 return 0; 3155 3156 if (pos == TGID_OFFSET - 2) { 3157 struct inode *inode = d_inode(ns->proc_self); 3158 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) 3159 return 0; 3160 ctx->pos = pos = pos + 1; 3161 } 3162 if (pos == TGID_OFFSET - 1) { 3163 struct inode *inode = d_inode(ns->proc_thread_self); 3164 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) 3165 return 0; 3166 ctx->pos = pos = pos + 1; 3167 } 3168 iter.tgid = pos - TGID_OFFSET; 3169 iter.task = NULL; 3170 for (iter = next_tgid(ns, iter); 3171 iter.task; 3172 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3173 char name[PROC_NUMBUF]; 3174 int len; 3175 3176 cond_resched(); 3177 if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE)) 3178 continue; 3179 3180 len = snprintf(name, sizeof(name), "%d", iter.tgid); 3181 ctx->pos = iter.tgid + TGID_OFFSET; 3182 if (!proc_fill_cache(file, ctx, name, len, 3183 proc_pid_instantiate, iter.task, NULL)) { 3184 put_task_struct(iter.task); 3185 return 0; 3186 } 3187 } 3188 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET; 3189 return 0; 3190 } 3191 3192 /* 3193 * proc_tid_comm_permission is a special permission function exclusively 3194 * used for the node /proc/<pid>/task/<tid>/comm. 3195 * It bypasses generic permission checks in the case where a task of the same 3196 * task group attempts to access the node. 3197 * The rationale behind this is that glibc and bionic access this node for 3198 * cross thread naming (pthread_set/getname_np(!self)). However, if 3199 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0, 3200 * which locks out the cross thread naming implementation. 3201 * This function makes sure that the node is always accessible for members of 3202 * same thread group. 3203 */ 3204 static int proc_tid_comm_permission(struct inode *inode, int mask) 3205 { 3206 bool is_same_tgroup; 3207 struct task_struct *task; 3208 3209 task = get_proc_task(inode); 3210 if (!task) 3211 return -ESRCH; 3212 is_same_tgroup = same_thread_group(current, task); 3213 put_task_struct(task); 3214 3215 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) { 3216 /* This file (/proc/<pid>/task/<tid>/comm) can always be 3217 * read or written by the members of the corresponding 3218 * thread group. 3219 */ 3220 return 0; 3221 } 3222 3223 return generic_permission(inode, mask); 3224 } 3225 3226 static const struct inode_operations proc_tid_comm_inode_operations = { 3227 .permission = proc_tid_comm_permission, 3228 }; 3229 3230 /* 3231 * Tasks 3232 */ 3233 static const struct pid_entry tid_base_stuff[] = { 3234 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3235 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3236 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3237 #ifdef CONFIG_NET 3238 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3239 #endif 3240 REG("environ", S_IRUSR, proc_environ_operations), 3241 REG("auxv", S_IRUSR, proc_auxv_operations), 3242 ONE("status", S_IRUGO, proc_pid_status), 3243 ONE("personality", S_IRUSR, proc_pid_personality), 3244 ONE("limits", S_IRUGO, proc_pid_limits), 3245 #ifdef CONFIG_SCHED_DEBUG 3246 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3247 #endif 3248 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR, 3249 &proc_tid_comm_inode_operations, 3250 &proc_pid_set_comm_operations, {}), 3251 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3252 ONE("syscall", S_IRUSR, proc_pid_syscall), 3253 #endif 3254 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 3255 ONE("stat", S_IRUGO, proc_tid_stat), 3256 ONE("statm", S_IRUGO, proc_pid_statm), 3257 REG("maps", S_IRUGO, proc_tid_maps_operations), 3258 #ifdef CONFIG_PROC_CHILDREN 3259 REG("children", S_IRUGO, proc_tid_children_operations), 3260 #endif 3261 #ifdef CONFIG_NUMA 3262 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations), 3263 #endif 3264 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3265 LNK("cwd", proc_cwd_link), 3266 LNK("root", proc_root_link), 3267 LNK("exe", proc_exe_link), 3268 REG("mounts", S_IRUGO, proc_mounts_operations), 3269 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3270 #ifdef CONFIG_PROC_PAGE_MONITOR 3271 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3272 REG("smaps", S_IRUGO, proc_tid_smaps_operations), 3273 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3274 #endif 3275 #ifdef CONFIG_SECURITY 3276 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3277 #endif 3278 #ifdef CONFIG_KALLSYMS 3279 ONE("wchan", S_IRUGO, proc_pid_wchan), 3280 #endif 3281 #ifdef CONFIG_STACKTRACE 3282 ONE("stack", S_IRUSR, proc_pid_stack), 3283 #endif 3284 #ifdef CONFIG_SCHED_INFO 3285 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 3286 #endif 3287 #ifdef CONFIG_LATENCYTOP 3288 REG("latency", S_IRUGO, proc_lstats_operations), 3289 #endif 3290 #ifdef CONFIG_PROC_PID_CPUSET 3291 ONE("cpuset", S_IRUGO, proc_cpuset_show), 3292 #endif 3293 #ifdef CONFIG_CGROUPS 3294 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3295 #endif 3296 ONE("oom_score", S_IRUGO, proc_oom_score), 3297 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3298 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3299 #ifdef CONFIG_AUDITSYSCALL 3300 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3301 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3302 #endif 3303 #ifdef CONFIG_FAULT_INJECTION 3304 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3305 #endif 3306 #ifdef CONFIG_TASK_IO_ACCOUNTING 3307 ONE("io", S_IRUSR, proc_tid_io_accounting), 3308 #endif 3309 #ifdef CONFIG_HARDWALL 3310 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 3311 #endif 3312 #ifdef CONFIG_USER_NS 3313 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3314 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3315 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3316 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3317 #endif 3318 }; 3319 3320 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx) 3321 { 3322 return proc_pident_readdir(file, ctx, 3323 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3324 } 3325 3326 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3327 { 3328 return proc_pident_lookup(dir, dentry, 3329 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3330 } 3331 3332 static const struct file_operations proc_tid_base_operations = { 3333 .read = generic_read_dir, 3334 .iterate_shared = proc_tid_base_readdir, 3335 .llseek = generic_file_llseek, 3336 }; 3337 3338 static const struct inode_operations proc_tid_base_inode_operations = { 3339 .lookup = proc_tid_base_lookup, 3340 .getattr = pid_getattr, 3341 .setattr = proc_setattr, 3342 }; 3343 3344 static int proc_task_instantiate(struct inode *dir, 3345 struct dentry *dentry, struct task_struct *task, const void *ptr) 3346 { 3347 struct inode *inode; 3348 inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3349 3350 if (!inode) 3351 goto out; 3352 inode->i_op = &proc_tid_base_inode_operations; 3353 inode->i_fop = &proc_tid_base_operations; 3354 inode->i_flags|=S_IMMUTABLE; 3355 3356 set_nlink(inode, nlink_tid); 3357 3358 d_set_d_op(dentry, &pid_dentry_operations); 3359 3360 d_add(dentry, inode); 3361 /* Close the race of the process dying before we return the dentry */ 3362 if (pid_revalidate(dentry, 0)) 3363 return 0; 3364 out: 3365 return -ENOENT; 3366 } 3367 3368 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3369 { 3370 int result = -ENOENT; 3371 struct task_struct *task; 3372 struct task_struct *leader = get_proc_task(dir); 3373 unsigned tid; 3374 struct pid_namespace *ns; 3375 3376 if (!leader) 3377 goto out_no_task; 3378 3379 tid = name_to_int(&dentry->d_name); 3380 if (tid == ~0U) 3381 goto out; 3382 3383 ns = dentry->d_sb->s_fs_info; 3384 rcu_read_lock(); 3385 task = find_task_by_pid_ns(tid, ns); 3386 if (task) 3387 get_task_struct(task); 3388 rcu_read_unlock(); 3389 if (!task) 3390 goto out; 3391 if (!same_thread_group(leader, task)) 3392 goto out_drop_task; 3393 3394 result = proc_task_instantiate(dir, dentry, task, NULL); 3395 out_drop_task: 3396 put_task_struct(task); 3397 out: 3398 put_task_struct(leader); 3399 out_no_task: 3400 return ERR_PTR(result); 3401 } 3402 3403 /* 3404 * Find the first tid of a thread group to return to user space. 3405 * 3406 * Usually this is just the thread group leader, but if the users 3407 * buffer was too small or there was a seek into the middle of the 3408 * directory we have more work todo. 3409 * 3410 * In the case of a short read we start with find_task_by_pid. 3411 * 3412 * In the case of a seek we start with the leader and walk nr 3413 * threads past it. 3414 */ 3415 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos, 3416 struct pid_namespace *ns) 3417 { 3418 struct task_struct *pos, *task; 3419 unsigned long nr = f_pos; 3420 3421 if (nr != f_pos) /* 32bit overflow? */ 3422 return NULL; 3423 3424 rcu_read_lock(); 3425 task = pid_task(pid, PIDTYPE_PID); 3426 if (!task) 3427 goto fail; 3428 3429 /* Attempt to start with the tid of a thread */ 3430 if (tid && nr) { 3431 pos = find_task_by_pid_ns(tid, ns); 3432 if (pos && same_thread_group(pos, task)) 3433 goto found; 3434 } 3435 3436 /* If nr exceeds the number of threads there is nothing todo */ 3437 if (nr >= get_nr_threads(task)) 3438 goto fail; 3439 3440 /* If we haven't found our starting place yet start 3441 * with the leader and walk nr threads forward. 3442 */ 3443 pos = task = task->group_leader; 3444 do { 3445 if (!nr--) 3446 goto found; 3447 } while_each_thread(task, pos); 3448 fail: 3449 pos = NULL; 3450 goto out; 3451 found: 3452 get_task_struct(pos); 3453 out: 3454 rcu_read_unlock(); 3455 return pos; 3456 } 3457 3458 /* 3459 * Find the next thread in the thread list. 3460 * Return NULL if there is an error or no next thread. 3461 * 3462 * The reference to the input task_struct is released. 3463 */ 3464 static struct task_struct *next_tid(struct task_struct *start) 3465 { 3466 struct task_struct *pos = NULL; 3467 rcu_read_lock(); 3468 if (pid_alive(start)) { 3469 pos = next_thread(start); 3470 if (thread_group_leader(pos)) 3471 pos = NULL; 3472 else 3473 get_task_struct(pos); 3474 } 3475 rcu_read_unlock(); 3476 put_task_struct(start); 3477 return pos; 3478 } 3479 3480 /* for the /proc/TGID/task/ directories */ 3481 static int proc_task_readdir(struct file *file, struct dir_context *ctx) 3482 { 3483 struct inode *inode = file_inode(file); 3484 struct task_struct *task; 3485 struct pid_namespace *ns; 3486 int tid; 3487 3488 if (proc_inode_is_dead(inode)) 3489 return -ENOENT; 3490 3491 if (!dir_emit_dots(file, ctx)) 3492 return 0; 3493 3494 /* f_version caches the tgid value that the last readdir call couldn't 3495 * return. lseek aka telldir automagically resets f_version to 0. 3496 */ 3497 ns = inode->i_sb->s_fs_info; 3498 tid = (int)file->f_version; 3499 file->f_version = 0; 3500 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); 3501 task; 3502 task = next_tid(task), ctx->pos++) { 3503 char name[PROC_NUMBUF]; 3504 int len; 3505 tid = task_pid_nr_ns(task, ns); 3506 len = snprintf(name, sizeof(name), "%d", tid); 3507 if (!proc_fill_cache(file, ctx, name, len, 3508 proc_task_instantiate, task, NULL)) { 3509 /* returning this tgid failed, save it as the first 3510 * pid for the next readir call */ 3511 file->f_version = (u64)tid; 3512 put_task_struct(task); 3513 break; 3514 } 3515 } 3516 3517 return 0; 3518 } 3519 3520 static int proc_task_getattr(const struct path *path, struct kstat *stat, 3521 u32 request_mask, unsigned int query_flags) 3522 { 3523 struct inode *inode = d_inode(path->dentry); 3524 struct task_struct *p = get_proc_task(inode); 3525 generic_fillattr(inode, stat); 3526 3527 if (p) { 3528 stat->nlink += get_nr_threads(p); 3529 put_task_struct(p); 3530 } 3531 3532 return 0; 3533 } 3534 3535 static const struct inode_operations proc_task_inode_operations = { 3536 .lookup = proc_task_lookup, 3537 .getattr = proc_task_getattr, 3538 .setattr = proc_setattr, 3539 .permission = proc_pid_permission, 3540 }; 3541 3542 static const struct file_operations proc_task_operations = { 3543 .read = generic_read_dir, 3544 .iterate_shared = proc_task_readdir, 3545 .llseek = generic_file_llseek, 3546 }; 3547 3548 void __init set_proc_pid_nlink(void) 3549 { 3550 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3551 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3552 } 3553