1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/proc/base.c 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 * 7 * proc base directory handling functions 8 * 9 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part. 10 * Instead of using magical inumbers to determine the kind of object 11 * we allocate and fill in-core inodes upon lookup. They don't even 12 * go into icache. We cache the reference to task_struct upon lookup too. 13 * Eventually it should become a filesystem in its own. We don't use the 14 * rest of procfs anymore. 15 * 16 * 17 * Changelog: 18 * 17-Jan-2005 19 * Allan Bezerra 20 * Bruna Moreira <bruna.moreira@indt.org.br> 21 * Edjard Mota <edjard.mota@indt.org.br> 22 * Ilias Biris <ilias.biris@indt.org.br> 23 * Mauricio Lin <mauricio.lin@indt.org.br> 24 * 25 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 26 * 27 * A new process specific entry (smaps) included in /proc. It shows the 28 * size of rss for each memory area. The maps entry lacks information 29 * about physical memory size (rss) for each mapped file, i.e., 30 * rss information for executables and library files. 31 * This additional information is useful for any tools that need to know 32 * about physical memory consumption for a process specific library. 33 * 34 * Changelog: 35 * 21-Feb-2005 36 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 37 * Pud inclusion in the page table walking. 38 * 39 * ChangeLog: 40 * 10-Mar-2005 41 * 10LE Instituto Nokia de Tecnologia - INdT: 42 * A better way to walks through the page table as suggested by Hugh Dickins. 43 * 44 * Simo Piiroinen <simo.piiroinen@nokia.com>: 45 * Smaps information related to shared, private, clean and dirty pages. 46 * 47 * Paul Mundt <paul.mundt@nokia.com>: 48 * Overall revision about smaps. 49 */ 50 51 #include <linux/uaccess.h> 52 53 #include <linux/errno.h> 54 #include <linux/time.h> 55 #include <linux/proc_fs.h> 56 #include <linux/stat.h> 57 #include <linux/task_io_accounting_ops.h> 58 #include <linux/init.h> 59 #include <linux/capability.h> 60 #include <linux/file.h> 61 #include <linux/fdtable.h> 62 #include <linux/generic-radix-tree.h> 63 #include <linux/string.h> 64 #include <linux/seq_file.h> 65 #include <linux/namei.h> 66 #include <linux/mnt_namespace.h> 67 #include <linux/mm.h> 68 #include <linux/swap.h> 69 #include <linux/rcupdate.h> 70 #include <linux/kallsyms.h> 71 #include <linux/stacktrace.h> 72 #include <linux/resource.h> 73 #include <linux/module.h> 74 #include <linux/mount.h> 75 #include <linux/security.h> 76 #include <linux/ptrace.h> 77 #include <linux/tracehook.h> 78 #include <linux/printk.h> 79 #include <linux/cache.h> 80 #include <linux/cgroup.h> 81 #include <linux/cpuset.h> 82 #include <linux/audit.h> 83 #include <linux/poll.h> 84 #include <linux/nsproxy.h> 85 #include <linux/oom.h> 86 #include <linux/elf.h> 87 #include <linux/pid_namespace.h> 88 #include <linux/user_namespace.h> 89 #include <linux/fs_struct.h> 90 #include <linux/slab.h> 91 #include <linux/sched/autogroup.h> 92 #include <linux/sched/mm.h> 93 #include <linux/sched/coredump.h> 94 #include <linux/sched/debug.h> 95 #include <linux/sched/stat.h> 96 #include <linux/posix-timers.h> 97 #include <trace/events/oom.h> 98 #include "internal.h" 99 #include "fd.h" 100 101 #include "../../lib/kstrtox.h" 102 103 /* NOTE: 104 * Implementing inode permission operations in /proc is almost 105 * certainly an error. Permission checks need to happen during 106 * each system call not at open time. The reason is that most of 107 * what we wish to check for permissions in /proc varies at runtime. 108 * 109 * The classic example of a problem is opening file descriptors 110 * in /proc for a task before it execs a suid executable. 111 */ 112 113 static u8 nlink_tid __ro_after_init; 114 static u8 nlink_tgid __ro_after_init; 115 116 struct pid_entry { 117 const char *name; 118 unsigned int len; 119 umode_t mode; 120 const struct inode_operations *iop; 121 const struct file_operations *fop; 122 union proc_op op; 123 }; 124 125 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 126 .name = (NAME), \ 127 .len = sizeof(NAME) - 1, \ 128 .mode = MODE, \ 129 .iop = IOP, \ 130 .fop = FOP, \ 131 .op = OP, \ 132 } 133 134 #define DIR(NAME, MODE, iops, fops) \ 135 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} ) 136 #define LNK(NAME, get_link) \ 137 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 138 &proc_pid_link_inode_operations, NULL, \ 139 { .proc_get_link = get_link } ) 140 #define REG(NAME, MODE, fops) \ 141 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {}) 142 #define ONE(NAME, MODE, show) \ 143 NOD(NAME, (S_IFREG|(MODE)), \ 144 NULL, &proc_single_file_operations, \ 145 { .proc_show = show } ) 146 #define ATTR(LSM, NAME, MODE) \ 147 NOD(NAME, (S_IFREG|(MODE)), \ 148 NULL, &proc_pid_attr_operations, \ 149 { .lsm = LSM }) 150 151 /* 152 * Count the number of hardlinks for the pid_entry table, excluding the . 153 * and .. links. 154 */ 155 static unsigned int __init pid_entry_nlink(const struct pid_entry *entries, 156 unsigned int n) 157 { 158 unsigned int i; 159 unsigned int count; 160 161 count = 2; 162 for (i = 0; i < n; ++i) { 163 if (S_ISDIR(entries[i].mode)) 164 ++count; 165 } 166 167 return count; 168 } 169 170 static int get_task_root(struct task_struct *task, struct path *root) 171 { 172 int result = -ENOENT; 173 174 task_lock(task); 175 if (task->fs) { 176 get_fs_root(task->fs, root); 177 result = 0; 178 } 179 task_unlock(task); 180 return result; 181 } 182 183 static int proc_cwd_link(struct dentry *dentry, struct path *path) 184 { 185 struct task_struct *task = get_proc_task(d_inode(dentry)); 186 int result = -ENOENT; 187 188 if (task) { 189 task_lock(task); 190 if (task->fs) { 191 get_fs_pwd(task->fs, path); 192 result = 0; 193 } 194 task_unlock(task); 195 put_task_struct(task); 196 } 197 return result; 198 } 199 200 static int proc_root_link(struct dentry *dentry, struct path *path) 201 { 202 struct task_struct *task = get_proc_task(d_inode(dentry)); 203 int result = -ENOENT; 204 205 if (task) { 206 result = get_task_root(task, path); 207 put_task_struct(task); 208 } 209 return result; 210 } 211 212 static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf, 213 size_t count, loff_t *ppos) 214 { 215 unsigned long arg_start, arg_end, env_start, env_end; 216 unsigned long pos, len; 217 char *page; 218 219 /* Check if process spawned far enough to have cmdline. */ 220 if (!mm->env_end) 221 return 0; 222 223 spin_lock(&mm->arg_lock); 224 arg_start = mm->arg_start; 225 arg_end = mm->arg_end; 226 env_start = mm->env_start; 227 env_end = mm->env_end; 228 spin_unlock(&mm->arg_lock); 229 230 if (arg_start >= arg_end) 231 return 0; 232 233 /* 234 * We have traditionally allowed the user to re-write 235 * the argument strings and overflow the end result 236 * into the environment section. But only do that if 237 * the environment area is contiguous to the arguments. 238 */ 239 if (env_start != arg_end || env_start >= env_end) 240 env_start = env_end = arg_end; 241 242 /* .. and limit it to a maximum of one page of slop */ 243 if (env_end >= arg_end + PAGE_SIZE) 244 env_end = arg_end + PAGE_SIZE - 1; 245 246 /* We're not going to care if "*ppos" has high bits set */ 247 pos = arg_start + *ppos; 248 249 /* .. but we do check the result is in the proper range */ 250 if (pos < arg_start || pos >= env_end) 251 return 0; 252 253 /* .. and we never go past env_end */ 254 if (env_end - pos < count) 255 count = env_end - pos; 256 257 page = (char *)__get_free_page(GFP_KERNEL); 258 if (!page) 259 return -ENOMEM; 260 261 len = 0; 262 while (count) { 263 int got; 264 size_t size = min_t(size_t, PAGE_SIZE, count); 265 long offset; 266 267 /* 268 * Are we already starting past the official end? 269 * We always include the last byte that is *supposed* 270 * to be NUL 271 */ 272 offset = (pos >= arg_end) ? pos - arg_end + 1 : 0; 273 274 got = access_remote_vm(mm, pos - offset, page, size + offset, FOLL_ANON); 275 if (got <= offset) 276 break; 277 got -= offset; 278 279 /* Don't walk past a NUL character once you hit arg_end */ 280 if (pos + got >= arg_end) { 281 int n = 0; 282 283 /* 284 * If we started before 'arg_end' but ended up 285 * at or after it, we start the NUL character 286 * check at arg_end-1 (where we expect the normal 287 * EOF to be). 288 * 289 * NOTE! This is smaller than 'got', because 290 * pos + got >= arg_end 291 */ 292 if (pos < arg_end) 293 n = arg_end - pos - 1; 294 295 /* Cut off at first NUL after 'n' */ 296 got = n + strnlen(page+n, offset+got-n); 297 if (got < offset) 298 break; 299 got -= offset; 300 301 /* Include the NUL if it existed */ 302 if (got < size) 303 got++; 304 } 305 306 got -= copy_to_user(buf, page+offset, got); 307 if (unlikely(!got)) { 308 if (!len) 309 len = -EFAULT; 310 break; 311 } 312 pos += got; 313 buf += got; 314 len += got; 315 count -= got; 316 } 317 318 free_page((unsigned long)page); 319 return len; 320 } 321 322 static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf, 323 size_t count, loff_t *pos) 324 { 325 struct mm_struct *mm; 326 ssize_t ret; 327 328 mm = get_task_mm(tsk); 329 if (!mm) 330 return 0; 331 332 ret = get_mm_cmdline(mm, buf, count, pos); 333 mmput(mm); 334 return ret; 335 } 336 337 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, 338 size_t count, loff_t *pos) 339 { 340 struct task_struct *tsk; 341 ssize_t ret; 342 343 BUG_ON(*pos < 0); 344 345 tsk = get_proc_task(file_inode(file)); 346 if (!tsk) 347 return -ESRCH; 348 ret = get_task_cmdline(tsk, buf, count, pos); 349 put_task_struct(tsk); 350 if (ret > 0) 351 *pos += ret; 352 return ret; 353 } 354 355 static const struct file_operations proc_pid_cmdline_ops = { 356 .read = proc_pid_cmdline_read, 357 .llseek = generic_file_llseek, 358 }; 359 360 #ifdef CONFIG_KALLSYMS 361 /* 362 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 363 * Returns the resolved symbol. If that fails, simply return the address. 364 */ 365 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns, 366 struct pid *pid, struct task_struct *task) 367 { 368 unsigned long wchan; 369 char symname[KSYM_NAME_LEN]; 370 371 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 372 goto print0; 373 374 wchan = get_wchan(task); 375 if (wchan && !lookup_symbol_name(wchan, symname)) { 376 seq_puts(m, symname); 377 return 0; 378 } 379 380 print0: 381 seq_putc(m, '0'); 382 return 0; 383 } 384 #endif /* CONFIG_KALLSYMS */ 385 386 static int lock_trace(struct task_struct *task) 387 { 388 int err = mutex_lock_killable(&task->signal->cred_guard_mutex); 389 if (err) 390 return err; 391 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) { 392 mutex_unlock(&task->signal->cred_guard_mutex); 393 return -EPERM; 394 } 395 return 0; 396 } 397 398 static void unlock_trace(struct task_struct *task) 399 { 400 mutex_unlock(&task->signal->cred_guard_mutex); 401 } 402 403 #ifdef CONFIG_STACKTRACE 404 405 #define MAX_STACK_TRACE_DEPTH 64 406 407 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, 408 struct pid *pid, struct task_struct *task) 409 { 410 unsigned long *entries; 411 int err; 412 413 /* 414 * The ability to racily run the kernel stack unwinder on a running task 415 * and then observe the unwinder output is scary; while it is useful for 416 * debugging kernel issues, it can also allow an attacker to leak kernel 417 * stack contents. 418 * Doing this in a manner that is at least safe from races would require 419 * some work to ensure that the remote task can not be scheduled; and 420 * even then, this would still expose the unwinder as local attack 421 * surface. 422 * Therefore, this interface is restricted to root. 423 */ 424 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) 425 return -EACCES; 426 427 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries), 428 GFP_KERNEL); 429 if (!entries) 430 return -ENOMEM; 431 432 err = lock_trace(task); 433 if (!err) { 434 unsigned int i, nr_entries; 435 436 nr_entries = stack_trace_save_tsk(task, entries, 437 MAX_STACK_TRACE_DEPTH, 0); 438 439 for (i = 0; i < nr_entries; i++) { 440 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]); 441 } 442 443 unlock_trace(task); 444 } 445 kfree(entries); 446 447 return err; 448 } 449 #endif 450 451 #ifdef CONFIG_SCHED_INFO 452 /* 453 * Provides /proc/PID/schedstat 454 */ 455 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, 456 struct pid *pid, struct task_struct *task) 457 { 458 if (unlikely(!sched_info_on())) 459 seq_puts(m, "0 0 0\n"); 460 else 461 seq_printf(m, "%llu %llu %lu\n", 462 (unsigned long long)task->se.sum_exec_runtime, 463 (unsigned long long)task->sched_info.run_delay, 464 task->sched_info.pcount); 465 466 return 0; 467 } 468 #endif 469 470 #ifdef CONFIG_LATENCYTOP 471 static int lstats_show_proc(struct seq_file *m, void *v) 472 { 473 int i; 474 struct inode *inode = m->private; 475 struct task_struct *task = get_proc_task(inode); 476 477 if (!task) 478 return -ESRCH; 479 seq_puts(m, "Latency Top version : v0.1\n"); 480 for (i = 0; i < LT_SAVECOUNT; i++) { 481 struct latency_record *lr = &task->latency_record[i]; 482 if (lr->backtrace[0]) { 483 int q; 484 seq_printf(m, "%i %li %li", 485 lr->count, lr->time, lr->max); 486 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 487 unsigned long bt = lr->backtrace[q]; 488 489 if (!bt) 490 break; 491 seq_printf(m, " %ps", (void *)bt); 492 } 493 seq_putc(m, '\n'); 494 } 495 496 } 497 put_task_struct(task); 498 return 0; 499 } 500 501 static int lstats_open(struct inode *inode, struct file *file) 502 { 503 return single_open(file, lstats_show_proc, inode); 504 } 505 506 static ssize_t lstats_write(struct file *file, const char __user *buf, 507 size_t count, loff_t *offs) 508 { 509 struct task_struct *task = get_proc_task(file_inode(file)); 510 511 if (!task) 512 return -ESRCH; 513 clear_tsk_latency_tracing(task); 514 put_task_struct(task); 515 516 return count; 517 } 518 519 static const struct file_operations proc_lstats_operations = { 520 .open = lstats_open, 521 .read = seq_read, 522 .write = lstats_write, 523 .llseek = seq_lseek, 524 .release = single_release, 525 }; 526 527 #endif 528 529 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns, 530 struct pid *pid, struct task_struct *task) 531 { 532 unsigned long totalpages = totalram_pages() + total_swap_pages; 533 unsigned long points = 0; 534 535 points = oom_badness(task, NULL, NULL, totalpages) * 536 1000 / totalpages; 537 seq_printf(m, "%lu\n", points); 538 539 return 0; 540 } 541 542 struct limit_names { 543 const char *name; 544 const char *unit; 545 }; 546 547 static const struct limit_names lnames[RLIM_NLIMITS] = { 548 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 549 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 550 [RLIMIT_DATA] = {"Max data size", "bytes"}, 551 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 552 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 553 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 554 [RLIMIT_NPROC] = {"Max processes", "processes"}, 555 [RLIMIT_NOFILE] = {"Max open files", "files"}, 556 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 557 [RLIMIT_AS] = {"Max address space", "bytes"}, 558 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 559 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 560 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 561 [RLIMIT_NICE] = {"Max nice priority", NULL}, 562 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 563 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 564 }; 565 566 /* Display limits for a process */ 567 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns, 568 struct pid *pid, struct task_struct *task) 569 { 570 unsigned int i; 571 unsigned long flags; 572 573 struct rlimit rlim[RLIM_NLIMITS]; 574 575 if (!lock_task_sighand(task, &flags)) 576 return 0; 577 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 578 unlock_task_sighand(task, &flags); 579 580 /* 581 * print the file header 582 */ 583 seq_puts(m, "Limit " 584 "Soft Limit " 585 "Hard Limit " 586 "Units \n"); 587 588 for (i = 0; i < RLIM_NLIMITS; i++) { 589 if (rlim[i].rlim_cur == RLIM_INFINITY) 590 seq_printf(m, "%-25s %-20s ", 591 lnames[i].name, "unlimited"); 592 else 593 seq_printf(m, "%-25s %-20lu ", 594 lnames[i].name, rlim[i].rlim_cur); 595 596 if (rlim[i].rlim_max == RLIM_INFINITY) 597 seq_printf(m, "%-20s ", "unlimited"); 598 else 599 seq_printf(m, "%-20lu ", rlim[i].rlim_max); 600 601 if (lnames[i].unit) 602 seq_printf(m, "%-10s\n", lnames[i].unit); 603 else 604 seq_putc(m, '\n'); 605 } 606 607 return 0; 608 } 609 610 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 611 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns, 612 struct pid *pid, struct task_struct *task) 613 { 614 struct syscall_info info; 615 u64 *args = &info.data.args[0]; 616 int res; 617 618 res = lock_trace(task); 619 if (res) 620 return res; 621 622 if (task_current_syscall(task, &info)) 623 seq_puts(m, "running\n"); 624 else if (info.data.nr < 0) 625 seq_printf(m, "%d 0x%llx 0x%llx\n", 626 info.data.nr, info.sp, info.data.instruction_pointer); 627 else 628 seq_printf(m, 629 "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n", 630 info.data.nr, 631 args[0], args[1], args[2], args[3], args[4], args[5], 632 info.sp, info.data.instruction_pointer); 633 unlock_trace(task); 634 635 return 0; 636 } 637 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 638 639 /************************************************************************/ 640 /* Here the fs part begins */ 641 /************************************************************************/ 642 643 /* permission checks */ 644 static int proc_fd_access_allowed(struct inode *inode) 645 { 646 struct task_struct *task; 647 int allowed = 0; 648 /* Allow access to a task's file descriptors if it is us or we 649 * may use ptrace attach to the process and find out that 650 * information. 651 */ 652 task = get_proc_task(inode); 653 if (task) { 654 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 655 put_task_struct(task); 656 } 657 return allowed; 658 } 659 660 int proc_setattr(struct dentry *dentry, struct iattr *attr) 661 { 662 int error; 663 struct inode *inode = d_inode(dentry); 664 665 if (attr->ia_valid & ATTR_MODE) 666 return -EPERM; 667 668 error = setattr_prepare(dentry, attr); 669 if (error) 670 return error; 671 672 setattr_copy(inode, attr); 673 mark_inode_dirty(inode); 674 return 0; 675 } 676 677 /* 678 * May current process learn task's sched/cmdline info (for hide_pid_min=1) 679 * or euid/egid (for hide_pid_min=2)? 680 */ 681 static bool has_pid_permissions(struct pid_namespace *pid, 682 struct task_struct *task, 683 int hide_pid_min) 684 { 685 if (pid->hide_pid < hide_pid_min) 686 return true; 687 if (in_group_p(pid->pid_gid)) 688 return true; 689 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 690 } 691 692 693 static int proc_pid_permission(struct inode *inode, int mask) 694 { 695 struct pid_namespace *pid = proc_pid_ns(inode); 696 struct task_struct *task; 697 bool has_perms; 698 699 task = get_proc_task(inode); 700 if (!task) 701 return -ESRCH; 702 has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS); 703 put_task_struct(task); 704 705 if (!has_perms) { 706 if (pid->hide_pid == HIDEPID_INVISIBLE) { 707 /* 708 * Let's make getdents(), stat(), and open() 709 * consistent with each other. If a process 710 * may not stat() a file, it shouldn't be seen 711 * in procfs at all. 712 */ 713 return -ENOENT; 714 } 715 716 return -EPERM; 717 } 718 return generic_permission(inode, mask); 719 } 720 721 722 723 static const struct inode_operations proc_def_inode_operations = { 724 .setattr = proc_setattr, 725 }; 726 727 static int proc_single_show(struct seq_file *m, void *v) 728 { 729 struct inode *inode = m->private; 730 struct pid_namespace *ns = proc_pid_ns(inode); 731 struct pid *pid = proc_pid(inode); 732 struct task_struct *task; 733 int ret; 734 735 task = get_pid_task(pid, PIDTYPE_PID); 736 if (!task) 737 return -ESRCH; 738 739 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 740 741 put_task_struct(task); 742 return ret; 743 } 744 745 static int proc_single_open(struct inode *inode, struct file *filp) 746 { 747 return single_open(filp, proc_single_show, inode); 748 } 749 750 static const struct file_operations proc_single_file_operations = { 751 .open = proc_single_open, 752 .read = seq_read, 753 .llseek = seq_lseek, 754 .release = single_release, 755 }; 756 757 758 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode) 759 { 760 struct task_struct *task = get_proc_task(inode); 761 struct mm_struct *mm = ERR_PTR(-ESRCH); 762 763 if (task) { 764 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS); 765 put_task_struct(task); 766 767 if (!IS_ERR_OR_NULL(mm)) { 768 /* ensure this mm_struct can't be freed */ 769 mmgrab(mm); 770 /* but do not pin its memory */ 771 mmput(mm); 772 } 773 } 774 775 return mm; 776 } 777 778 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) 779 { 780 struct mm_struct *mm = proc_mem_open(inode, mode); 781 782 if (IS_ERR(mm)) 783 return PTR_ERR(mm); 784 785 file->private_data = mm; 786 return 0; 787 } 788 789 static int mem_open(struct inode *inode, struct file *file) 790 { 791 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH); 792 793 /* OK to pass negative loff_t, we can catch out-of-range */ 794 file->f_mode |= FMODE_UNSIGNED_OFFSET; 795 796 return ret; 797 } 798 799 static ssize_t mem_rw(struct file *file, char __user *buf, 800 size_t count, loff_t *ppos, int write) 801 { 802 struct mm_struct *mm = file->private_data; 803 unsigned long addr = *ppos; 804 ssize_t copied; 805 char *page; 806 unsigned int flags; 807 808 if (!mm) 809 return 0; 810 811 page = (char *)__get_free_page(GFP_KERNEL); 812 if (!page) 813 return -ENOMEM; 814 815 copied = 0; 816 if (!mmget_not_zero(mm)) 817 goto free; 818 819 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0); 820 821 while (count > 0) { 822 int this_len = min_t(int, count, PAGE_SIZE); 823 824 if (write && copy_from_user(page, buf, this_len)) { 825 copied = -EFAULT; 826 break; 827 } 828 829 this_len = access_remote_vm(mm, addr, page, this_len, flags); 830 if (!this_len) { 831 if (!copied) 832 copied = -EIO; 833 break; 834 } 835 836 if (!write && copy_to_user(buf, page, this_len)) { 837 copied = -EFAULT; 838 break; 839 } 840 841 buf += this_len; 842 addr += this_len; 843 copied += this_len; 844 count -= this_len; 845 } 846 *ppos = addr; 847 848 mmput(mm); 849 free: 850 free_page((unsigned long) page); 851 return copied; 852 } 853 854 static ssize_t mem_read(struct file *file, char __user *buf, 855 size_t count, loff_t *ppos) 856 { 857 return mem_rw(file, buf, count, ppos, 0); 858 } 859 860 static ssize_t mem_write(struct file *file, const char __user *buf, 861 size_t count, loff_t *ppos) 862 { 863 return mem_rw(file, (char __user*)buf, count, ppos, 1); 864 } 865 866 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 867 { 868 switch (orig) { 869 case 0: 870 file->f_pos = offset; 871 break; 872 case 1: 873 file->f_pos += offset; 874 break; 875 default: 876 return -EINVAL; 877 } 878 force_successful_syscall_return(); 879 return file->f_pos; 880 } 881 882 static int mem_release(struct inode *inode, struct file *file) 883 { 884 struct mm_struct *mm = file->private_data; 885 if (mm) 886 mmdrop(mm); 887 return 0; 888 } 889 890 static const struct file_operations proc_mem_operations = { 891 .llseek = mem_lseek, 892 .read = mem_read, 893 .write = mem_write, 894 .open = mem_open, 895 .release = mem_release, 896 }; 897 898 static int environ_open(struct inode *inode, struct file *file) 899 { 900 return __mem_open(inode, file, PTRACE_MODE_READ); 901 } 902 903 static ssize_t environ_read(struct file *file, char __user *buf, 904 size_t count, loff_t *ppos) 905 { 906 char *page; 907 unsigned long src = *ppos; 908 int ret = 0; 909 struct mm_struct *mm = file->private_data; 910 unsigned long env_start, env_end; 911 912 /* Ensure the process spawned far enough to have an environment. */ 913 if (!mm || !mm->env_end) 914 return 0; 915 916 page = (char *)__get_free_page(GFP_KERNEL); 917 if (!page) 918 return -ENOMEM; 919 920 ret = 0; 921 if (!mmget_not_zero(mm)) 922 goto free; 923 924 spin_lock(&mm->arg_lock); 925 env_start = mm->env_start; 926 env_end = mm->env_end; 927 spin_unlock(&mm->arg_lock); 928 929 while (count > 0) { 930 size_t this_len, max_len; 931 int retval; 932 933 if (src >= (env_end - env_start)) 934 break; 935 936 this_len = env_end - (env_start + src); 937 938 max_len = min_t(size_t, PAGE_SIZE, count); 939 this_len = min(max_len, this_len); 940 941 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON); 942 943 if (retval <= 0) { 944 ret = retval; 945 break; 946 } 947 948 if (copy_to_user(buf, page, retval)) { 949 ret = -EFAULT; 950 break; 951 } 952 953 ret += retval; 954 src += retval; 955 buf += retval; 956 count -= retval; 957 } 958 *ppos = src; 959 mmput(mm); 960 961 free: 962 free_page((unsigned long) page); 963 return ret; 964 } 965 966 static const struct file_operations proc_environ_operations = { 967 .open = environ_open, 968 .read = environ_read, 969 .llseek = generic_file_llseek, 970 .release = mem_release, 971 }; 972 973 static int auxv_open(struct inode *inode, struct file *file) 974 { 975 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS); 976 } 977 978 static ssize_t auxv_read(struct file *file, char __user *buf, 979 size_t count, loff_t *ppos) 980 { 981 struct mm_struct *mm = file->private_data; 982 unsigned int nwords = 0; 983 984 if (!mm) 985 return 0; 986 do { 987 nwords += 2; 988 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 989 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv, 990 nwords * sizeof(mm->saved_auxv[0])); 991 } 992 993 static const struct file_operations proc_auxv_operations = { 994 .open = auxv_open, 995 .read = auxv_read, 996 .llseek = generic_file_llseek, 997 .release = mem_release, 998 }; 999 1000 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count, 1001 loff_t *ppos) 1002 { 1003 struct task_struct *task = get_proc_task(file_inode(file)); 1004 char buffer[PROC_NUMBUF]; 1005 int oom_adj = OOM_ADJUST_MIN; 1006 size_t len; 1007 1008 if (!task) 1009 return -ESRCH; 1010 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX) 1011 oom_adj = OOM_ADJUST_MAX; 1012 else 1013 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) / 1014 OOM_SCORE_ADJ_MAX; 1015 put_task_struct(task); 1016 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj); 1017 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1018 } 1019 1020 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy) 1021 { 1022 static DEFINE_MUTEX(oom_adj_mutex); 1023 struct mm_struct *mm = NULL; 1024 struct task_struct *task; 1025 int err = 0; 1026 1027 task = get_proc_task(file_inode(file)); 1028 if (!task) 1029 return -ESRCH; 1030 1031 mutex_lock(&oom_adj_mutex); 1032 if (legacy) { 1033 if (oom_adj < task->signal->oom_score_adj && 1034 !capable(CAP_SYS_RESOURCE)) { 1035 err = -EACCES; 1036 goto err_unlock; 1037 } 1038 /* 1039 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use 1040 * /proc/pid/oom_score_adj instead. 1041 */ 1042 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 1043 current->comm, task_pid_nr(current), task_pid_nr(task), 1044 task_pid_nr(task)); 1045 } else { 1046 if ((short)oom_adj < task->signal->oom_score_adj_min && 1047 !capable(CAP_SYS_RESOURCE)) { 1048 err = -EACCES; 1049 goto err_unlock; 1050 } 1051 } 1052 1053 /* 1054 * Make sure we will check other processes sharing the mm if this is 1055 * not vfrok which wants its own oom_score_adj. 1056 * pin the mm so it doesn't go away and get reused after task_unlock 1057 */ 1058 if (!task->vfork_done) { 1059 struct task_struct *p = find_lock_task_mm(task); 1060 1061 if (p) { 1062 if (atomic_read(&p->mm->mm_users) > 1) { 1063 mm = p->mm; 1064 mmgrab(mm); 1065 } 1066 task_unlock(p); 1067 } 1068 } 1069 1070 task->signal->oom_score_adj = oom_adj; 1071 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1072 task->signal->oom_score_adj_min = (short)oom_adj; 1073 trace_oom_score_adj_update(task); 1074 1075 if (mm) { 1076 struct task_struct *p; 1077 1078 rcu_read_lock(); 1079 for_each_process(p) { 1080 if (same_thread_group(task, p)) 1081 continue; 1082 1083 /* do not touch kernel threads or the global init */ 1084 if (p->flags & PF_KTHREAD || is_global_init(p)) 1085 continue; 1086 1087 task_lock(p); 1088 if (!p->vfork_done && process_shares_mm(p, mm)) { 1089 p->signal->oom_score_adj = oom_adj; 1090 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1091 p->signal->oom_score_adj_min = (short)oom_adj; 1092 } 1093 task_unlock(p); 1094 } 1095 rcu_read_unlock(); 1096 mmdrop(mm); 1097 } 1098 err_unlock: 1099 mutex_unlock(&oom_adj_mutex); 1100 put_task_struct(task); 1101 return err; 1102 } 1103 1104 /* 1105 * /proc/pid/oom_adj exists solely for backwards compatibility with previous 1106 * kernels. The effective policy is defined by oom_score_adj, which has a 1107 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly. 1108 * Values written to oom_adj are simply mapped linearly to oom_score_adj. 1109 * Processes that become oom disabled via oom_adj will still be oom disabled 1110 * with this implementation. 1111 * 1112 * oom_adj cannot be removed since existing userspace binaries use it. 1113 */ 1114 static ssize_t oom_adj_write(struct file *file, const char __user *buf, 1115 size_t count, loff_t *ppos) 1116 { 1117 char buffer[PROC_NUMBUF]; 1118 int oom_adj; 1119 int err; 1120 1121 memset(buffer, 0, sizeof(buffer)); 1122 if (count > sizeof(buffer) - 1) 1123 count = sizeof(buffer) - 1; 1124 if (copy_from_user(buffer, buf, count)) { 1125 err = -EFAULT; 1126 goto out; 1127 } 1128 1129 err = kstrtoint(strstrip(buffer), 0, &oom_adj); 1130 if (err) 1131 goto out; 1132 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) && 1133 oom_adj != OOM_DISABLE) { 1134 err = -EINVAL; 1135 goto out; 1136 } 1137 1138 /* 1139 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 1140 * value is always attainable. 1141 */ 1142 if (oom_adj == OOM_ADJUST_MAX) 1143 oom_adj = OOM_SCORE_ADJ_MAX; 1144 else 1145 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE; 1146 1147 err = __set_oom_adj(file, oom_adj, true); 1148 out: 1149 return err < 0 ? err : count; 1150 } 1151 1152 static const struct file_operations proc_oom_adj_operations = { 1153 .read = oom_adj_read, 1154 .write = oom_adj_write, 1155 .llseek = generic_file_llseek, 1156 }; 1157 1158 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 1159 size_t count, loff_t *ppos) 1160 { 1161 struct task_struct *task = get_proc_task(file_inode(file)); 1162 char buffer[PROC_NUMBUF]; 1163 short oom_score_adj = OOM_SCORE_ADJ_MIN; 1164 size_t len; 1165 1166 if (!task) 1167 return -ESRCH; 1168 oom_score_adj = task->signal->oom_score_adj; 1169 put_task_struct(task); 1170 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj); 1171 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1172 } 1173 1174 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1175 size_t count, loff_t *ppos) 1176 { 1177 char buffer[PROC_NUMBUF]; 1178 int oom_score_adj; 1179 int err; 1180 1181 memset(buffer, 0, sizeof(buffer)); 1182 if (count > sizeof(buffer) - 1) 1183 count = sizeof(buffer) - 1; 1184 if (copy_from_user(buffer, buf, count)) { 1185 err = -EFAULT; 1186 goto out; 1187 } 1188 1189 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 1190 if (err) 1191 goto out; 1192 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1193 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1194 err = -EINVAL; 1195 goto out; 1196 } 1197 1198 err = __set_oom_adj(file, oom_score_adj, false); 1199 out: 1200 return err < 0 ? err : count; 1201 } 1202 1203 static const struct file_operations proc_oom_score_adj_operations = { 1204 .read = oom_score_adj_read, 1205 .write = oom_score_adj_write, 1206 .llseek = default_llseek, 1207 }; 1208 1209 #ifdef CONFIG_AUDIT 1210 #define TMPBUFLEN 11 1211 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1212 size_t count, loff_t *ppos) 1213 { 1214 struct inode * inode = file_inode(file); 1215 struct task_struct *task = get_proc_task(inode); 1216 ssize_t length; 1217 char tmpbuf[TMPBUFLEN]; 1218 1219 if (!task) 1220 return -ESRCH; 1221 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1222 from_kuid(file->f_cred->user_ns, 1223 audit_get_loginuid(task))); 1224 put_task_struct(task); 1225 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1226 } 1227 1228 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1229 size_t count, loff_t *ppos) 1230 { 1231 struct inode * inode = file_inode(file); 1232 uid_t loginuid; 1233 kuid_t kloginuid; 1234 int rv; 1235 1236 rcu_read_lock(); 1237 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1238 rcu_read_unlock(); 1239 return -EPERM; 1240 } 1241 rcu_read_unlock(); 1242 1243 if (*ppos != 0) { 1244 /* No partial writes. */ 1245 return -EINVAL; 1246 } 1247 1248 rv = kstrtou32_from_user(buf, count, 10, &loginuid); 1249 if (rv < 0) 1250 return rv; 1251 1252 /* is userspace tring to explicitly UNSET the loginuid? */ 1253 if (loginuid == AUDIT_UID_UNSET) { 1254 kloginuid = INVALID_UID; 1255 } else { 1256 kloginuid = make_kuid(file->f_cred->user_ns, loginuid); 1257 if (!uid_valid(kloginuid)) 1258 return -EINVAL; 1259 } 1260 1261 rv = audit_set_loginuid(kloginuid); 1262 if (rv < 0) 1263 return rv; 1264 return count; 1265 } 1266 1267 static const struct file_operations proc_loginuid_operations = { 1268 .read = proc_loginuid_read, 1269 .write = proc_loginuid_write, 1270 .llseek = generic_file_llseek, 1271 }; 1272 1273 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1274 size_t count, loff_t *ppos) 1275 { 1276 struct inode * inode = file_inode(file); 1277 struct task_struct *task = get_proc_task(inode); 1278 ssize_t length; 1279 char tmpbuf[TMPBUFLEN]; 1280 1281 if (!task) 1282 return -ESRCH; 1283 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1284 audit_get_sessionid(task)); 1285 put_task_struct(task); 1286 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1287 } 1288 1289 static const struct file_operations proc_sessionid_operations = { 1290 .read = proc_sessionid_read, 1291 .llseek = generic_file_llseek, 1292 }; 1293 #endif 1294 1295 #ifdef CONFIG_FAULT_INJECTION 1296 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1297 size_t count, loff_t *ppos) 1298 { 1299 struct task_struct *task = get_proc_task(file_inode(file)); 1300 char buffer[PROC_NUMBUF]; 1301 size_t len; 1302 int make_it_fail; 1303 1304 if (!task) 1305 return -ESRCH; 1306 make_it_fail = task->make_it_fail; 1307 put_task_struct(task); 1308 1309 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1310 1311 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1312 } 1313 1314 static ssize_t proc_fault_inject_write(struct file * file, 1315 const char __user * buf, size_t count, loff_t *ppos) 1316 { 1317 struct task_struct *task; 1318 char buffer[PROC_NUMBUF]; 1319 int make_it_fail; 1320 int rv; 1321 1322 if (!capable(CAP_SYS_RESOURCE)) 1323 return -EPERM; 1324 memset(buffer, 0, sizeof(buffer)); 1325 if (count > sizeof(buffer) - 1) 1326 count = sizeof(buffer) - 1; 1327 if (copy_from_user(buffer, buf, count)) 1328 return -EFAULT; 1329 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail); 1330 if (rv < 0) 1331 return rv; 1332 if (make_it_fail < 0 || make_it_fail > 1) 1333 return -EINVAL; 1334 1335 task = get_proc_task(file_inode(file)); 1336 if (!task) 1337 return -ESRCH; 1338 task->make_it_fail = make_it_fail; 1339 put_task_struct(task); 1340 1341 return count; 1342 } 1343 1344 static const struct file_operations proc_fault_inject_operations = { 1345 .read = proc_fault_inject_read, 1346 .write = proc_fault_inject_write, 1347 .llseek = generic_file_llseek, 1348 }; 1349 1350 static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf, 1351 size_t count, loff_t *ppos) 1352 { 1353 struct task_struct *task; 1354 int err; 1355 unsigned int n; 1356 1357 err = kstrtouint_from_user(buf, count, 0, &n); 1358 if (err) 1359 return err; 1360 1361 task = get_proc_task(file_inode(file)); 1362 if (!task) 1363 return -ESRCH; 1364 task->fail_nth = n; 1365 put_task_struct(task); 1366 1367 return count; 1368 } 1369 1370 static ssize_t proc_fail_nth_read(struct file *file, char __user *buf, 1371 size_t count, loff_t *ppos) 1372 { 1373 struct task_struct *task; 1374 char numbuf[PROC_NUMBUF]; 1375 ssize_t len; 1376 1377 task = get_proc_task(file_inode(file)); 1378 if (!task) 1379 return -ESRCH; 1380 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth); 1381 put_task_struct(task); 1382 return simple_read_from_buffer(buf, count, ppos, numbuf, len); 1383 } 1384 1385 static const struct file_operations proc_fail_nth_operations = { 1386 .read = proc_fail_nth_read, 1387 .write = proc_fail_nth_write, 1388 }; 1389 #endif 1390 1391 1392 #ifdef CONFIG_SCHED_DEBUG 1393 /* 1394 * Print out various scheduling related per-task fields: 1395 */ 1396 static int sched_show(struct seq_file *m, void *v) 1397 { 1398 struct inode *inode = m->private; 1399 struct pid_namespace *ns = proc_pid_ns(inode); 1400 struct task_struct *p; 1401 1402 p = get_proc_task(inode); 1403 if (!p) 1404 return -ESRCH; 1405 proc_sched_show_task(p, ns, m); 1406 1407 put_task_struct(p); 1408 1409 return 0; 1410 } 1411 1412 static ssize_t 1413 sched_write(struct file *file, const char __user *buf, 1414 size_t count, loff_t *offset) 1415 { 1416 struct inode *inode = file_inode(file); 1417 struct task_struct *p; 1418 1419 p = get_proc_task(inode); 1420 if (!p) 1421 return -ESRCH; 1422 proc_sched_set_task(p); 1423 1424 put_task_struct(p); 1425 1426 return count; 1427 } 1428 1429 static int sched_open(struct inode *inode, struct file *filp) 1430 { 1431 return single_open(filp, sched_show, inode); 1432 } 1433 1434 static const struct file_operations proc_pid_sched_operations = { 1435 .open = sched_open, 1436 .read = seq_read, 1437 .write = sched_write, 1438 .llseek = seq_lseek, 1439 .release = single_release, 1440 }; 1441 1442 #endif 1443 1444 #ifdef CONFIG_SCHED_AUTOGROUP 1445 /* 1446 * Print out autogroup related information: 1447 */ 1448 static int sched_autogroup_show(struct seq_file *m, void *v) 1449 { 1450 struct inode *inode = m->private; 1451 struct task_struct *p; 1452 1453 p = get_proc_task(inode); 1454 if (!p) 1455 return -ESRCH; 1456 proc_sched_autogroup_show_task(p, m); 1457 1458 put_task_struct(p); 1459 1460 return 0; 1461 } 1462 1463 static ssize_t 1464 sched_autogroup_write(struct file *file, const char __user *buf, 1465 size_t count, loff_t *offset) 1466 { 1467 struct inode *inode = file_inode(file); 1468 struct task_struct *p; 1469 char buffer[PROC_NUMBUF]; 1470 int nice; 1471 int err; 1472 1473 memset(buffer, 0, sizeof(buffer)); 1474 if (count > sizeof(buffer) - 1) 1475 count = sizeof(buffer) - 1; 1476 if (copy_from_user(buffer, buf, count)) 1477 return -EFAULT; 1478 1479 err = kstrtoint(strstrip(buffer), 0, &nice); 1480 if (err < 0) 1481 return err; 1482 1483 p = get_proc_task(inode); 1484 if (!p) 1485 return -ESRCH; 1486 1487 err = proc_sched_autogroup_set_nice(p, nice); 1488 if (err) 1489 count = err; 1490 1491 put_task_struct(p); 1492 1493 return count; 1494 } 1495 1496 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1497 { 1498 int ret; 1499 1500 ret = single_open(filp, sched_autogroup_show, NULL); 1501 if (!ret) { 1502 struct seq_file *m = filp->private_data; 1503 1504 m->private = inode; 1505 } 1506 return ret; 1507 } 1508 1509 static const struct file_operations proc_pid_sched_autogroup_operations = { 1510 .open = sched_autogroup_open, 1511 .read = seq_read, 1512 .write = sched_autogroup_write, 1513 .llseek = seq_lseek, 1514 .release = single_release, 1515 }; 1516 1517 #endif /* CONFIG_SCHED_AUTOGROUP */ 1518 1519 static ssize_t comm_write(struct file *file, const char __user *buf, 1520 size_t count, loff_t *offset) 1521 { 1522 struct inode *inode = file_inode(file); 1523 struct task_struct *p; 1524 char buffer[TASK_COMM_LEN]; 1525 const size_t maxlen = sizeof(buffer) - 1; 1526 1527 memset(buffer, 0, sizeof(buffer)); 1528 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count)) 1529 return -EFAULT; 1530 1531 p = get_proc_task(inode); 1532 if (!p) 1533 return -ESRCH; 1534 1535 if (same_thread_group(current, p)) 1536 set_task_comm(p, buffer); 1537 else 1538 count = -EINVAL; 1539 1540 put_task_struct(p); 1541 1542 return count; 1543 } 1544 1545 static int comm_show(struct seq_file *m, void *v) 1546 { 1547 struct inode *inode = m->private; 1548 struct task_struct *p; 1549 1550 p = get_proc_task(inode); 1551 if (!p) 1552 return -ESRCH; 1553 1554 proc_task_name(m, p, false); 1555 seq_putc(m, '\n'); 1556 1557 put_task_struct(p); 1558 1559 return 0; 1560 } 1561 1562 static int comm_open(struct inode *inode, struct file *filp) 1563 { 1564 return single_open(filp, comm_show, inode); 1565 } 1566 1567 static const struct file_operations proc_pid_set_comm_operations = { 1568 .open = comm_open, 1569 .read = seq_read, 1570 .write = comm_write, 1571 .llseek = seq_lseek, 1572 .release = single_release, 1573 }; 1574 1575 static int proc_exe_link(struct dentry *dentry, struct path *exe_path) 1576 { 1577 struct task_struct *task; 1578 struct file *exe_file; 1579 1580 task = get_proc_task(d_inode(dentry)); 1581 if (!task) 1582 return -ENOENT; 1583 exe_file = get_task_exe_file(task); 1584 put_task_struct(task); 1585 if (exe_file) { 1586 *exe_path = exe_file->f_path; 1587 path_get(&exe_file->f_path); 1588 fput(exe_file); 1589 return 0; 1590 } else 1591 return -ENOENT; 1592 } 1593 1594 static const char *proc_pid_get_link(struct dentry *dentry, 1595 struct inode *inode, 1596 struct delayed_call *done) 1597 { 1598 struct path path; 1599 int error = -EACCES; 1600 1601 if (!dentry) 1602 return ERR_PTR(-ECHILD); 1603 1604 /* Are we allowed to snoop on the tasks file descriptors? */ 1605 if (!proc_fd_access_allowed(inode)) 1606 goto out; 1607 1608 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1609 if (error) 1610 goto out; 1611 1612 nd_jump_link(&path); 1613 return NULL; 1614 out: 1615 return ERR_PTR(error); 1616 } 1617 1618 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1619 { 1620 char *tmp = (char *)__get_free_page(GFP_KERNEL); 1621 char *pathname; 1622 int len; 1623 1624 if (!tmp) 1625 return -ENOMEM; 1626 1627 pathname = d_path(path, tmp, PAGE_SIZE); 1628 len = PTR_ERR(pathname); 1629 if (IS_ERR(pathname)) 1630 goto out; 1631 len = tmp + PAGE_SIZE - 1 - pathname; 1632 1633 if (len > buflen) 1634 len = buflen; 1635 if (copy_to_user(buffer, pathname, len)) 1636 len = -EFAULT; 1637 out: 1638 free_page((unsigned long)tmp); 1639 return len; 1640 } 1641 1642 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1643 { 1644 int error = -EACCES; 1645 struct inode *inode = d_inode(dentry); 1646 struct path path; 1647 1648 /* Are we allowed to snoop on the tasks file descriptors? */ 1649 if (!proc_fd_access_allowed(inode)) 1650 goto out; 1651 1652 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1653 if (error) 1654 goto out; 1655 1656 error = do_proc_readlink(&path, buffer, buflen); 1657 path_put(&path); 1658 out: 1659 return error; 1660 } 1661 1662 const struct inode_operations proc_pid_link_inode_operations = { 1663 .readlink = proc_pid_readlink, 1664 .get_link = proc_pid_get_link, 1665 .setattr = proc_setattr, 1666 }; 1667 1668 1669 /* building an inode */ 1670 1671 void task_dump_owner(struct task_struct *task, umode_t mode, 1672 kuid_t *ruid, kgid_t *rgid) 1673 { 1674 /* Depending on the state of dumpable compute who should own a 1675 * proc file for a task. 1676 */ 1677 const struct cred *cred; 1678 kuid_t uid; 1679 kgid_t gid; 1680 1681 if (unlikely(task->flags & PF_KTHREAD)) { 1682 *ruid = GLOBAL_ROOT_UID; 1683 *rgid = GLOBAL_ROOT_GID; 1684 return; 1685 } 1686 1687 /* Default to the tasks effective ownership */ 1688 rcu_read_lock(); 1689 cred = __task_cred(task); 1690 uid = cred->euid; 1691 gid = cred->egid; 1692 rcu_read_unlock(); 1693 1694 /* 1695 * Before the /proc/pid/status file was created the only way to read 1696 * the effective uid of a /process was to stat /proc/pid. Reading 1697 * /proc/pid/status is slow enough that procps and other packages 1698 * kept stating /proc/pid. To keep the rules in /proc simple I have 1699 * made this apply to all per process world readable and executable 1700 * directories. 1701 */ 1702 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) { 1703 struct mm_struct *mm; 1704 task_lock(task); 1705 mm = task->mm; 1706 /* Make non-dumpable tasks owned by some root */ 1707 if (mm) { 1708 if (get_dumpable(mm) != SUID_DUMP_USER) { 1709 struct user_namespace *user_ns = mm->user_ns; 1710 1711 uid = make_kuid(user_ns, 0); 1712 if (!uid_valid(uid)) 1713 uid = GLOBAL_ROOT_UID; 1714 1715 gid = make_kgid(user_ns, 0); 1716 if (!gid_valid(gid)) 1717 gid = GLOBAL_ROOT_GID; 1718 } 1719 } else { 1720 uid = GLOBAL_ROOT_UID; 1721 gid = GLOBAL_ROOT_GID; 1722 } 1723 task_unlock(task); 1724 } 1725 *ruid = uid; 1726 *rgid = gid; 1727 } 1728 1729 struct inode *proc_pid_make_inode(struct super_block * sb, 1730 struct task_struct *task, umode_t mode) 1731 { 1732 struct inode * inode; 1733 struct proc_inode *ei; 1734 1735 /* We need a new inode */ 1736 1737 inode = new_inode(sb); 1738 if (!inode) 1739 goto out; 1740 1741 /* Common stuff */ 1742 ei = PROC_I(inode); 1743 inode->i_mode = mode; 1744 inode->i_ino = get_next_ino(); 1745 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 1746 inode->i_op = &proc_def_inode_operations; 1747 1748 /* 1749 * grab the reference to task. 1750 */ 1751 ei->pid = get_task_pid(task, PIDTYPE_PID); 1752 if (!ei->pid) 1753 goto out_unlock; 1754 1755 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); 1756 security_task_to_inode(task, inode); 1757 1758 out: 1759 return inode; 1760 1761 out_unlock: 1762 iput(inode); 1763 return NULL; 1764 } 1765 1766 int pid_getattr(const struct path *path, struct kstat *stat, 1767 u32 request_mask, unsigned int query_flags) 1768 { 1769 struct inode *inode = d_inode(path->dentry); 1770 struct pid_namespace *pid = proc_pid_ns(inode); 1771 struct task_struct *task; 1772 1773 generic_fillattr(inode, stat); 1774 1775 stat->uid = GLOBAL_ROOT_UID; 1776 stat->gid = GLOBAL_ROOT_GID; 1777 rcu_read_lock(); 1778 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1779 if (task) { 1780 if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) { 1781 rcu_read_unlock(); 1782 /* 1783 * This doesn't prevent learning whether PID exists, 1784 * it only makes getattr() consistent with readdir(). 1785 */ 1786 return -ENOENT; 1787 } 1788 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid); 1789 } 1790 rcu_read_unlock(); 1791 return 0; 1792 } 1793 1794 /* dentry stuff */ 1795 1796 /* 1797 * Set <pid>/... inode ownership (can change due to setuid(), etc.) 1798 */ 1799 void pid_update_inode(struct task_struct *task, struct inode *inode) 1800 { 1801 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid); 1802 1803 inode->i_mode &= ~(S_ISUID | S_ISGID); 1804 security_task_to_inode(task, inode); 1805 } 1806 1807 /* 1808 * Rewrite the inode's ownerships here because the owning task may have 1809 * performed a setuid(), etc. 1810 * 1811 */ 1812 static int pid_revalidate(struct dentry *dentry, unsigned int flags) 1813 { 1814 struct inode *inode; 1815 struct task_struct *task; 1816 1817 if (flags & LOOKUP_RCU) 1818 return -ECHILD; 1819 1820 inode = d_inode(dentry); 1821 task = get_proc_task(inode); 1822 1823 if (task) { 1824 pid_update_inode(task, inode); 1825 put_task_struct(task); 1826 return 1; 1827 } 1828 return 0; 1829 } 1830 1831 static inline bool proc_inode_is_dead(struct inode *inode) 1832 { 1833 return !proc_pid(inode)->tasks[PIDTYPE_PID].first; 1834 } 1835 1836 int pid_delete_dentry(const struct dentry *dentry) 1837 { 1838 /* Is the task we represent dead? 1839 * If so, then don't put the dentry on the lru list, 1840 * kill it immediately. 1841 */ 1842 return proc_inode_is_dead(d_inode(dentry)); 1843 } 1844 1845 const struct dentry_operations pid_dentry_operations = 1846 { 1847 .d_revalidate = pid_revalidate, 1848 .d_delete = pid_delete_dentry, 1849 }; 1850 1851 /* Lookups */ 1852 1853 /* 1854 * Fill a directory entry. 1855 * 1856 * If possible create the dcache entry and derive our inode number and 1857 * file type from dcache entry. 1858 * 1859 * Since all of the proc inode numbers are dynamically generated, the inode 1860 * numbers do not exist until the inode is cache. This means creating the 1861 * the dcache entry in readdir is necessary to keep the inode numbers 1862 * reported by readdir in sync with the inode numbers reported 1863 * by stat. 1864 */ 1865 bool proc_fill_cache(struct file *file, struct dir_context *ctx, 1866 const char *name, unsigned int len, 1867 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1868 { 1869 struct dentry *child, *dir = file->f_path.dentry; 1870 struct qstr qname = QSTR_INIT(name, len); 1871 struct inode *inode; 1872 unsigned type = DT_UNKNOWN; 1873 ino_t ino = 1; 1874 1875 child = d_hash_and_lookup(dir, &qname); 1876 if (!child) { 1877 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 1878 child = d_alloc_parallel(dir, &qname, &wq); 1879 if (IS_ERR(child)) 1880 goto end_instantiate; 1881 if (d_in_lookup(child)) { 1882 struct dentry *res; 1883 res = instantiate(child, task, ptr); 1884 d_lookup_done(child); 1885 if (unlikely(res)) { 1886 dput(child); 1887 child = res; 1888 if (IS_ERR(child)) 1889 goto end_instantiate; 1890 } 1891 } 1892 } 1893 inode = d_inode(child); 1894 ino = inode->i_ino; 1895 type = inode->i_mode >> 12; 1896 dput(child); 1897 end_instantiate: 1898 return dir_emit(ctx, name, len, ino, type); 1899 } 1900 1901 /* 1902 * dname_to_vma_addr - maps a dentry name into two unsigned longs 1903 * which represent vma start and end addresses. 1904 */ 1905 static int dname_to_vma_addr(struct dentry *dentry, 1906 unsigned long *start, unsigned long *end) 1907 { 1908 const char *str = dentry->d_name.name; 1909 unsigned long long sval, eval; 1910 unsigned int len; 1911 1912 if (str[0] == '0' && str[1] != '-') 1913 return -EINVAL; 1914 len = _parse_integer(str, 16, &sval); 1915 if (len & KSTRTOX_OVERFLOW) 1916 return -EINVAL; 1917 if (sval != (unsigned long)sval) 1918 return -EINVAL; 1919 str += len; 1920 1921 if (*str != '-') 1922 return -EINVAL; 1923 str++; 1924 1925 if (str[0] == '0' && str[1]) 1926 return -EINVAL; 1927 len = _parse_integer(str, 16, &eval); 1928 if (len & KSTRTOX_OVERFLOW) 1929 return -EINVAL; 1930 if (eval != (unsigned long)eval) 1931 return -EINVAL; 1932 str += len; 1933 1934 if (*str != '\0') 1935 return -EINVAL; 1936 1937 *start = sval; 1938 *end = eval; 1939 1940 return 0; 1941 } 1942 1943 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags) 1944 { 1945 unsigned long vm_start, vm_end; 1946 bool exact_vma_exists = false; 1947 struct mm_struct *mm = NULL; 1948 struct task_struct *task; 1949 struct inode *inode; 1950 int status = 0; 1951 1952 if (flags & LOOKUP_RCU) 1953 return -ECHILD; 1954 1955 inode = d_inode(dentry); 1956 task = get_proc_task(inode); 1957 if (!task) 1958 goto out_notask; 1959 1960 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); 1961 if (IS_ERR_OR_NULL(mm)) 1962 goto out; 1963 1964 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 1965 down_read(&mm->mmap_sem); 1966 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end); 1967 up_read(&mm->mmap_sem); 1968 } 1969 1970 mmput(mm); 1971 1972 if (exact_vma_exists) { 1973 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); 1974 1975 security_task_to_inode(task, inode); 1976 status = 1; 1977 } 1978 1979 out: 1980 put_task_struct(task); 1981 1982 out_notask: 1983 return status; 1984 } 1985 1986 static const struct dentry_operations tid_map_files_dentry_operations = { 1987 .d_revalidate = map_files_d_revalidate, 1988 .d_delete = pid_delete_dentry, 1989 }; 1990 1991 static int map_files_get_link(struct dentry *dentry, struct path *path) 1992 { 1993 unsigned long vm_start, vm_end; 1994 struct vm_area_struct *vma; 1995 struct task_struct *task; 1996 struct mm_struct *mm; 1997 int rc; 1998 1999 rc = -ENOENT; 2000 task = get_proc_task(d_inode(dentry)); 2001 if (!task) 2002 goto out; 2003 2004 mm = get_task_mm(task); 2005 put_task_struct(task); 2006 if (!mm) 2007 goto out; 2008 2009 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 2010 if (rc) 2011 goto out_mmput; 2012 2013 rc = -ENOENT; 2014 down_read(&mm->mmap_sem); 2015 vma = find_exact_vma(mm, vm_start, vm_end); 2016 if (vma && vma->vm_file) { 2017 *path = vma->vm_file->f_path; 2018 path_get(path); 2019 rc = 0; 2020 } 2021 up_read(&mm->mmap_sem); 2022 2023 out_mmput: 2024 mmput(mm); 2025 out: 2026 return rc; 2027 } 2028 2029 struct map_files_info { 2030 unsigned long start; 2031 unsigned long end; 2032 fmode_t mode; 2033 }; 2034 2035 /* 2036 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the 2037 * symlinks may be used to bypass permissions on ancestor directories in the 2038 * path to the file in question. 2039 */ 2040 static const char * 2041 proc_map_files_get_link(struct dentry *dentry, 2042 struct inode *inode, 2043 struct delayed_call *done) 2044 { 2045 if (!capable(CAP_SYS_ADMIN)) 2046 return ERR_PTR(-EPERM); 2047 2048 return proc_pid_get_link(dentry, inode, done); 2049 } 2050 2051 /* 2052 * Identical to proc_pid_link_inode_operations except for get_link() 2053 */ 2054 static const struct inode_operations proc_map_files_link_inode_operations = { 2055 .readlink = proc_pid_readlink, 2056 .get_link = proc_map_files_get_link, 2057 .setattr = proc_setattr, 2058 }; 2059 2060 static struct dentry * 2061 proc_map_files_instantiate(struct dentry *dentry, 2062 struct task_struct *task, const void *ptr) 2063 { 2064 fmode_t mode = (fmode_t)(unsigned long)ptr; 2065 struct proc_inode *ei; 2066 struct inode *inode; 2067 2068 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK | 2069 ((mode & FMODE_READ ) ? S_IRUSR : 0) | 2070 ((mode & FMODE_WRITE) ? S_IWUSR : 0)); 2071 if (!inode) 2072 return ERR_PTR(-ENOENT); 2073 2074 ei = PROC_I(inode); 2075 ei->op.proc_get_link = map_files_get_link; 2076 2077 inode->i_op = &proc_map_files_link_inode_operations; 2078 inode->i_size = 64; 2079 2080 d_set_d_op(dentry, &tid_map_files_dentry_operations); 2081 return d_splice_alias(inode, dentry); 2082 } 2083 2084 static struct dentry *proc_map_files_lookup(struct inode *dir, 2085 struct dentry *dentry, unsigned int flags) 2086 { 2087 unsigned long vm_start, vm_end; 2088 struct vm_area_struct *vma; 2089 struct task_struct *task; 2090 struct dentry *result; 2091 struct mm_struct *mm; 2092 2093 result = ERR_PTR(-ENOENT); 2094 task = get_proc_task(dir); 2095 if (!task) 2096 goto out; 2097 2098 result = ERR_PTR(-EACCES); 2099 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2100 goto out_put_task; 2101 2102 result = ERR_PTR(-ENOENT); 2103 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 2104 goto out_put_task; 2105 2106 mm = get_task_mm(task); 2107 if (!mm) 2108 goto out_put_task; 2109 2110 down_read(&mm->mmap_sem); 2111 vma = find_exact_vma(mm, vm_start, vm_end); 2112 if (!vma) 2113 goto out_no_vma; 2114 2115 if (vma->vm_file) 2116 result = proc_map_files_instantiate(dentry, task, 2117 (void *)(unsigned long)vma->vm_file->f_mode); 2118 2119 out_no_vma: 2120 up_read(&mm->mmap_sem); 2121 mmput(mm); 2122 out_put_task: 2123 put_task_struct(task); 2124 out: 2125 return result; 2126 } 2127 2128 static const struct inode_operations proc_map_files_inode_operations = { 2129 .lookup = proc_map_files_lookup, 2130 .permission = proc_fd_permission, 2131 .setattr = proc_setattr, 2132 }; 2133 2134 static int 2135 proc_map_files_readdir(struct file *file, struct dir_context *ctx) 2136 { 2137 struct vm_area_struct *vma; 2138 struct task_struct *task; 2139 struct mm_struct *mm; 2140 unsigned long nr_files, pos, i; 2141 GENRADIX(struct map_files_info) fa; 2142 struct map_files_info *p; 2143 int ret; 2144 2145 genradix_init(&fa); 2146 2147 ret = -ENOENT; 2148 task = get_proc_task(file_inode(file)); 2149 if (!task) 2150 goto out; 2151 2152 ret = -EACCES; 2153 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2154 goto out_put_task; 2155 2156 ret = 0; 2157 if (!dir_emit_dots(file, ctx)) 2158 goto out_put_task; 2159 2160 mm = get_task_mm(task); 2161 if (!mm) 2162 goto out_put_task; 2163 down_read(&mm->mmap_sem); 2164 2165 nr_files = 0; 2166 2167 /* 2168 * We need two passes here: 2169 * 2170 * 1) Collect vmas of mapped files with mmap_sem taken 2171 * 2) Release mmap_sem and instantiate entries 2172 * 2173 * otherwise we get lockdep complained, since filldir() 2174 * routine might require mmap_sem taken in might_fault(). 2175 */ 2176 2177 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 2178 if (!vma->vm_file) 2179 continue; 2180 if (++pos <= ctx->pos) 2181 continue; 2182 2183 p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL); 2184 if (!p) { 2185 ret = -ENOMEM; 2186 up_read(&mm->mmap_sem); 2187 mmput(mm); 2188 goto out_put_task; 2189 } 2190 2191 p->start = vma->vm_start; 2192 p->end = vma->vm_end; 2193 p->mode = vma->vm_file->f_mode; 2194 } 2195 up_read(&mm->mmap_sem); 2196 mmput(mm); 2197 2198 for (i = 0; i < nr_files; i++) { 2199 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */ 2200 unsigned int len; 2201 2202 p = genradix_ptr(&fa, i); 2203 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end); 2204 if (!proc_fill_cache(file, ctx, 2205 buf, len, 2206 proc_map_files_instantiate, 2207 task, 2208 (void *)(unsigned long)p->mode)) 2209 break; 2210 ctx->pos++; 2211 } 2212 2213 out_put_task: 2214 put_task_struct(task); 2215 out: 2216 genradix_free(&fa); 2217 return ret; 2218 } 2219 2220 static const struct file_operations proc_map_files_operations = { 2221 .read = generic_read_dir, 2222 .iterate_shared = proc_map_files_readdir, 2223 .llseek = generic_file_llseek, 2224 }; 2225 2226 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS) 2227 struct timers_private { 2228 struct pid *pid; 2229 struct task_struct *task; 2230 struct sighand_struct *sighand; 2231 struct pid_namespace *ns; 2232 unsigned long flags; 2233 }; 2234 2235 static void *timers_start(struct seq_file *m, loff_t *pos) 2236 { 2237 struct timers_private *tp = m->private; 2238 2239 tp->task = get_pid_task(tp->pid, PIDTYPE_PID); 2240 if (!tp->task) 2241 return ERR_PTR(-ESRCH); 2242 2243 tp->sighand = lock_task_sighand(tp->task, &tp->flags); 2244 if (!tp->sighand) 2245 return ERR_PTR(-ESRCH); 2246 2247 return seq_list_start(&tp->task->signal->posix_timers, *pos); 2248 } 2249 2250 static void *timers_next(struct seq_file *m, void *v, loff_t *pos) 2251 { 2252 struct timers_private *tp = m->private; 2253 return seq_list_next(v, &tp->task->signal->posix_timers, pos); 2254 } 2255 2256 static void timers_stop(struct seq_file *m, void *v) 2257 { 2258 struct timers_private *tp = m->private; 2259 2260 if (tp->sighand) { 2261 unlock_task_sighand(tp->task, &tp->flags); 2262 tp->sighand = NULL; 2263 } 2264 2265 if (tp->task) { 2266 put_task_struct(tp->task); 2267 tp->task = NULL; 2268 } 2269 } 2270 2271 static int show_timer(struct seq_file *m, void *v) 2272 { 2273 struct k_itimer *timer; 2274 struct timers_private *tp = m->private; 2275 int notify; 2276 static const char * const nstr[] = { 2277 [SIGEV_SIGNAL] = "signal", 2278 [SIGEV_NONE] = "none", 2279 [SIGEV_THREAD] = "thread", 2280 }; 2281 2282 timer = list_entry((struct list_head *)v, struct k_itimer, list); 2283 notify = timer->it_sigev_notify; 2284 2285 seq_printf(m, "ID: %d\n", timer->it_id); 2286 seq_printf(m, "signal: %d/%px\n", 2287 timer->sigq->info.si_signo, 2288 timer->sigq->info.si_value.sival_ptr); 2289 seq_printf(m, "notify: %s/%s.%d\n", 2290 nstr[notify & ~SIGEV_THREAD_ID], 2291 (notify & SIGEV_THREAD_ID) ? "tid" : "pid", 2292 pid_nr_ns(timer->it_pid, tp->ns)); 2293 seq_printf(m, "ClockID: %d\n", timer->it_clock); 2294 2295 return 0; 2296 } 2297 2298 static const struct seq_operations proc_timers_seq_ops = { 2299 .start = timers_start, 2300 .next = timers_next, 2301 .stop = timers_stop, 2302 .show = show_timer, 2303 }; 2304 2305 static int proc_timers_open(struct inode *inode, struct file *file) 2306 { 2307 struct timers_private *tp; 2308 2309 tp = __seq_open_private(file, &proc_timers_seq_ops, 2310 sizeof(struct timers_private)); 2311 if (!tp) 2312 return -ENOMEM; 2313 2314 tp->pid = proc_pid(inode); 2315 tp->ns = proc_pid_ns(inode); 2316 return 0; 2317 } 2318 2319 static const struct file_operations proc_timers_operations = { 2320 .open = proc_timers_open, 2321 .read = seq_read, 2322 .llseek = seq_lseek, 2323 .release = seq_release_private, 2324 }; 2325 #endif 2326 2327 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf, 2328 size_t count, loff_t *offset) 2329 { 2330 struct inode *inode = file_inode(file); 2331 struct task_struct *p; 2332 u64 slack_ns; 2333 int err; 2334 2335 err = kstrtoull_from_user(buf, count, 10, &slack_ns); 2336 if (err < 0) 2337 return err; 2338 2339 p = get_proc_task(inode); 2340 if (!p) 2341 return -ESRCH; 2342 2343 if (p != current) { 2344 rcu_read_lock(); 2345 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { 2346 rcu_read_unlock(); 2347 count = -EPERM; 2348 goto out; 2349 } 2350 rcu_read_unlock(); 2351 2352 err = security_task_setscheduler(p); 2353 if (err) { 2354 count = err; 2355 goto out; 2356 } 2357 } 2358 2359 task_lock(p); 2360 if (slack_ns == 0) 2361 p->timer_slack_ns = p->default_timer_slack_ns; 2362 else 2363 p->timer_slack_ns = slack_ns; 2364 task_unlock(p); 2365 2366 out: 2367 put_task_struct(p); 2368 2369 return count; 2370 } 2371 2372 static int timerslack_ns_show(struct seq_file *m, void *v) 2373 { 2374 struct inode *inode = m->private; 2375 struct task_struct *p; 2376 int err = 0; 2377 2378 p = get_proc_task(inode); 2379 if (!p) 2380 return -ESRCH; 2381 2382 if (p != current) { 2383 rcu_read_lock(); 2384 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { 2385 rcu_read_unlock(); 2386 err = -EPERM; 2387 goto out; 2388 } 2389 rcu_read_unlock(); 2390 2391 err = security_task_getscheduler(p); 2392 if (err) 2393 goto out; 2394 } 2395 2396 task_lock(p); 2397 seq_printf(m, "%llu\n", p->timer_slack_ns); 2398 task_unlock(p); 2399 2400 out: 2401 put_task_struct(p); 2402 2403 return err; 2404 } 2405 2406 static int timerslack_ns_open(struct inode *inode, struct file *filp) 2407 { 2408 return single_open(filp, timerslack_ns_show, inode); 2409 } 2410 2411 static const struct file_operations proc_pid_set_timerslack_ns_operations = { 2412 .open = timerslack_ns_open, 2413 .read = seq_read, 2414 .write = timerslack_ns_write, 2415 .llseek = seq_lseek, 2416 .release = single_release, 2417 }; 2418 2419 static struct dentry *proc_pident_instantiate(struct dentry *dentry, 2420 struct task_struct *task, const void *ptr) 2421 { 2422 const struct pid_entry *p = ptr; 2423 struct inode *inode; 2424 struct proc_inode *ei; 2425 2426 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode); 2427 if (!inode) 2428 return ERR_PTR(-ENOENT); 2429 2430 ei = PROC_I(inode); 2431 if (S_ISDIR(inode->i_mode)) 2432 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2433 if (p->iop) 2434 inode->i_op = p->iop; 2435 if (p->fop) 2436 inode->i_fop = p->fop; 2437 ei->op = p->op; 2438 pid_update_inode(task, inode); 2439 d_set_d_op(dentry, &pid_dentry_operations); 2440 return d_splice_alias(inode, dentry); 2441 } 2442 2443 static struct dentry *proc_pident_lookup(struct inode *dir, 2444 struct dentry *dentry, 2445 const struct pid_entry *p, 2446 const struct pid_entry *end) 2447 { 2448 struct task_struct *task = get_proc_task(dir); 2449 struct dentry *res = ERR_PTR(-ENOENT); 2450 2451 if (!task) 2452 goto out_no_task; 2453 2454 /* 2455 * Yes, it does not scale. And it should not. Don't add 2456 * new entries into /proc/<tgid>/ without very good reasons. 2457 */ 2458 for (; p < end; p++) { 2459 if (p->len != dentry->d_name.len) 2460 continue; 2461 if (!memcmp(dentry->d_name.name, p->name, p->len)) { 2462 res = proc_pident_instantiate(dentry, task, p); 2463 break; 2464 } 2465 } 2466 put_task_struct(task); 2467 out_no_task: 2468 return res; 2469 } 2470 2471 static int proc_pident_readdir(struct file *file, struct dir_context *ctx, 2472 const struct pid_entry *ents, unsigned int nents) 2473 { 2474 struct task_struct *task = get_proc_task(file_inode(file)); 2475 const struct pid_entry *p; 2476 2477 if (!task) 2478 return -ENOENT; 2479 2480 if (!dir_emit_dots(file, ctx)) 2481 goto out; 2482 2483 if (ctx->pos >= nents + 2) 2484 goto out; 2485 2486 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) { 2487 if (!proc_fill_cache(file, ctx, p->name, p->len, 2488 proc_pident_instantiate, task, p)) 2489 break; 2490 ctx->pos++; 2491 } 2492 out: 2493 put_task_struct(task); 2494 return 0; 2495 } 2496 2497 #ifdef CONFIG_SECURITY 2498 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2499 size_t count, loff_t *ppos) 2500 { 2501 struct inode * inode = file_inode(file); 2502 char *p = NULL; 2503 ssize_t length; 2504 struct task_struct *task = get_proc_task(inode); 2505 2506 if (!task) 2507 return -ESRCH; 2508 2509 length = security_getprocattr(task, PROC_I(inode)->op.lsm, 2510 (char*)file->f_path.dentry->d_name.name, 2511 &p); 2512 put_task_struct(task); 2513 if (length > 0) 2514 length = simple_read_from_buffer(buf, count, ppos, p, length); 2515 kfree(p); 2516 return length; 2517 } 2518 2519 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2520 size_t count, loff_t *ppos) 2521 { 2522 struct inode * inode = file_inode(file); 2523 struct task_struct *task; 2524 void *page; 2525 int rv; 2526 2527 rcu_read_lock(); 2528 task = pid_task(proc_pid(inode), PIDTYPE_PID); 2529 if (!task) { 2530 rcu_read_unlock(); 2531 return -ESRCH; 2532 } 2533 /* A task may only write its own attributes. */ 2534 if (current != task) { 2535 rcu_read_unlock(); 2536 return -EACCES; 2537 } 2538 /* Prevent changes to overridden credentials. */ 2539 if (current_cred() != current_real_cred()) { 2540 rcu_read_unlock(); 2541 return -EBUSY; 2542 } 2543 rcu_read_unlock(); 2544 2545 if (count > PAGE_SIZE) 2546 count = PAGE_SIZE; 2547 2548 /* No partial writes. */ 2549 if (*ppos != 0) 2550 return -EINVAL; 2551 2552 page = memdup_user(buf, count); 2553 if (IS_ERR(page)) { 2554 rv = PTR_ERR(page); 2555 goto out; 2556 } 2557 2558 /* Guard against adverse ptrace interaction */ 2559 rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex); 2560 if (rv < 0) 2561 goto out_free; 2562 2563 rv = security_setprocattr(PROC_I(inode)->op.lsm, 2564 file->f_path.dentry->d_name.name, page, 2565 count); 2566 mutex_unlock(¤t->signal->cred_guard_mutex); 2567 out_free: 2568 kfree(page); 2569 out: 2570 return rv; 2571 } 2572 2573 static const struct file_operations proc_pid_attr_operations = { 2574 .read = proc_pid_attr_read, 2575 .write = proc_pid_attr_write, 2576 .llseek = generic_file_llseek, 2577 }; 2578 2579 #define LSM_DIR_OPS(LSM) \ 2580 static int proc_##LSM##_attr_dir_iterate(struct file *filp, \ 2581 struct dir_context *ctx) \ 2582 { \ 2583 return proc_pident_readdir(filp, ctx, \ 2584 LSM##_attr_dir_stuff, \ 2585 ARRAY_SIZE(LSM##_attr_dir_stuff)); \ 2586 } \ 2587 \ 2588 static const struct file_operations proc_##LSM##_attr_dir_ops = { \ 2589 .read = generic_read_dir, \ 2590 .iterate = proc_##LSM##_attr_dir_iterate, \ 2591 .llseek = default_llseek, \ 2592 }; \ 2593 \ 2594 static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \ 2595 struct dentry *dentry, unsigned int flags) \ 2596 { \ 2597 return proc_pident_lookup(dir, dentry, \ 2598 LSM##_attr_dir_stuff, \ 2599 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \ 2600 } \ 2601 \ 2602 static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \ 2603 .lookup = proc_##LSM##_attr_dir_lookup, \ 2604 .getattr = pid_getattr, \ 2605 .setattr = proc_setattr, \ 2606 } 2607 2608 #ifdef CONFIG_SECURITY_SMACK 2609 static const struct pid_entry smack_attr_dir_stuff[] = { 2610 ATTR("smack", "current", 0666), 2611 }; 2612 LSM_DIR_OPS(smack); 2613 #endif 2614 2615 static const struct pid_entry attr_dir_stuff[] = { 2616 ATTR(NULL, "current", 0666), 2617 ATTR(NULL, "prev", 0444), 2618 ATTR(NULL, "exec", 0666), 2619 ATTR(NULL, "fscreate", 0666), 2620 ATTR(NULL, "keycreate", 0666), 2621 ATTR(NULL, "sockcreate", 0666), 2622 #ifdef CONFIG_SECURITY_SMACK 2623 DIR("smack", 0555, 2624 proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops), 2625 #endif 2626 }; 2627 2628 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx) 2629 { 2630 return proc_pident_readdir(file, ctx, 2631 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2632 } 2633 2634 static const struct file_operations proc_attr_dir_operations = { 2635 .read = generic_read_dir, 2636 .iterate_shared = proc_attr_dir_readdir, 2637 .llseek = generic_file_llseek, 2638 }; 2639 2640 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2641 struct dentry *dentry, unsigned int flags) 2642 { 2643 return proc_pident_lookup(dir, dentry, 2644 attr_dir_stuff, 2645 attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff)); 2646 } 2647 2648 static const struct inode_operations proc_attr_dir_inode_operations = { 2649 .lookup = proc_attr_dir_lookup, 2650 .getattr = pid_getattr, 2651 .setattr = proc_setattr, 2652 }; 2653 2654 #endif 2655 2656 #ifdef CONFIG_ELF_CORE 2657 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2658 size_t count, loff_t *ppos) 2659 { 2660 struct task_struct *task = get_proc_task(file_inode(file)); 2661 struct mm_struct *mm; 2662 char buffer[PROC_NUMBUF]; 2663 size_t len; 2664 int ret; 2665 2666 if (!task) 2667 return -ESRCH; 2668 2669 ret = 0; 2670 mm = get_task_mm(task); 2671 if (mm) { 2672 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2673 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2674 MMF_DUMP_FILTER_SHIFT)); 2675 mmput(mm); 2676 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2677 } 2678 2679 put_task_struct(task); 2680 2681 return ret; 2682 } 2683 2684 static ssize_t proc_coredump_filter_write(struct file *file, 2685 const char __user *buf, 2686 size_t count, 2687 loff_t *ppos) 2688 { 2689 struct task_struct *task; 2690 struct mm_struct *mm; 2691 unsigned int val; 2692 int ret; 2693 int i; 2694 unsigned long mask; 2695 2696 ret = kstrtouint_from_user(buf, count, 0, &val); 2697 if (ret < 0) 2698 return ret; 2699 2700 ret = -ESRCH; 2701 task = get_proc_task(file_inode(file)); 2702 if (!task) 2703 goto out_no_task; 2704 2705 mm = get_task_mm(task); 2706 if (!mm) 2707 goto out_no_mm; 2708 ret = 0; 2709 2710 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2711 if (val & mask) 2712 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2713 else 2714 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2715 } 2716 2717 mmput(mm); 2718 out_no_mm: 2719 put_task_struct(task); 2720 out_no_task: 2721 if (ret < 0) 2722 return ret; 2723 return count; 2724 } 2725 2726 static const struct file_operations proc_coredump_filter_operations = { 2727 .read = proc_coredump_filter_read, 2728 .write = proc_coredump_filter_write, 2729 .llseek = generic_file_llseek, 2730 }; 2731 #endif 2732 2733 #ifdef CONFIG_TASK_IO_ACCOUNTING 2734 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole) 2735 { 2736 struct task_io_accounting acct = task->ioac; 2737 unsigned long flags; 2738 int result; 2739 2740 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2741 if (result) 2742 return result; 2743 2744 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { 2745 result = -EACCES; 2746 goto out_unlock; 2747 } 2748 2749 if (whole && lock_task_sighand(task, &flags)) { 2750 struct task_struct *t = task; 2751 2752 task_io_accounting_add(&acct, &task->signal->ioac); 2753 while_each_thread(task, t) 2754 task_io_accounting_add(&acct, &t->ioac); 2755 2756 unlock_task_sighand(task, &flags); 2757 } 2758 seq_printf(m, 2759 "rchar: %llu\n" 2760 "wchar: %llu\n" 2761 "syscr: %llu\n" 2762 "syscw: %llu\n" 2763 "read_bytes: %llu\n" 2764 "write_bytes: %llu\n" 2765 "cancelled_write_bytes: %llu\n", 2766 (unsigned long long)acct.rchar, 2767 (unsigned long long)acct.wchar, 2768 (unsigned long long)acct.syscr, 2769 (unsigned long long)acct.syscw, 2770 (unsigned long long)acct.read_bytes, 2771 (unsigned long long)acct.write_bytes, 2772 (unsigned long long)acct.cancelled_write_bytes); 2773 result = 0; 2774 2775 out_unlock: 2776 mutex_unlock(&task->signal->cred_guard_mutex); 2777 return result; 2778 } 2779 2780 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2781 struct pid *pid, struct task_struct *task) 2782 { 2783 return do_io_accounting(task, m, 0); 2784 } 2785 2786 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2787 struct pid *pid, struct task_struct *task) 2788 { 2789 return do_io_accounting(task, m, 1); 2790 } 2791 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2792 2793 #ifdef CONFIG_USER_NS 2794 static int proc_id_map_open(struct inode *inode, struct file *file, 2795 const struct seq_operations *seq_ops) 2796 { 2797 struct user_namespace *ns = NULL; 2798 struct task_struct *task; 2799 struct seq_file *seq; 2800 int ret = -EINVAL; 2801 2802 task = get_proc_task(inode); 2803 if (task) { 2804 rcu_read_lock(); 2805 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2806 rcu_read_unlock(); 2807 put_task_struct(task); 2808 } 2809 if (!ns) 2810 goto err; 2811 2812 ret = seq_open(file, seq_ops); 2813 if (ret) 2814 goto err_put_ns; 2815 2816 seq = file->private_data; 2817 seq->private = ns; 2818 2819 return 0; 2820 err_put_ns: 2821 put_user_ns(ns); 2822 err: 2823 return ret; 2824 } 2825 2826 static int proc_id_map_release(struct inode *inode, struct file *file) 2827 { 2828 struct seq_file *seq = file->private_data; 2829 struct user_namespace *ns = seq->private; 2830 put_user_ns(ns); 2831 return seq_release(inode, file); 2832 } 2833 2834 static int proc_uid_map_open(struct inode *inode, struct file *file) 2835 { 2836 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2837 } 2838 2839 static int proc_gid_map_open(struct inode *inode, struct file *file) 2840 { 2841 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2842 } 2843 2844 static int proc_projid_map_open(struct inode *inode, struct file *file) 2845 { 2846 return proc_id_map_open(inode, file, &proc_projid_seq_operations); 2847 } 2848 2849 static const struct file_operations proc_uid_map_operations = { 2850 .open = proc_uid_map_open, 2851 .write = proc_uid_map_write, 2852 .read = seq_read, 2853 .llseek = seq_lseek, 2854 .release = proc_id_map_release, 2855 }; 2856 2857 static const struct file_operations proc_gid_map_operations = { 2858 .open = proc_gid_map_open, 2859 .write = proc_gid_map_write, 2860 .read = seq_read, 2861 .llseek = seq_lseek, 2862 .release = proc_id_map_release, 2863 }; 2864 2865 static const struct file_operations proc_projid_map_operations = { 2866 .open = proc_projid_map_open, 2867 .write = proc_projid_map_write, 2868 .read = seq_read, 2869 .llseek = seq_lseek, 2870 .release = proc_id_map_release, 2871 }; 2872 2873 static int proc_setgroups_open(struct inode *inode, struct file *file) 2874 { 2875 struct user_namespace *ns = NULL; 2876 struct task_struct *task; 2877 int ret; 2878 2879 ret = -ESRCH; 2880 task = get_proc_task(inode); 2881 if (task) { 2882 rcu_read_lock(); 2883 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2884 rcu_read_unlock(); 2885 put_task_struct(task); 2886 } 2887 if (!ns) 2888 goto err; 2889 2890 if (file->f_mode & FMODE_WRITE) { 2891 ret = -EACCES; 2892 if (!ns_capable(ns, CAP_SYS_ADMIN)) 2893 goto err_put_ns; 2894 } 2895 2896 ret = single_open(file, &proc_setgroups_show, ns); 2897 if (ret) 2898 goto err_put_ns; 2899 2900 return 0; 2901 err_put_ns: 2902 put_user_ns(ns); 2903 err: 2904 return ret; 2905 } 2906 2907 static int proc_setgroups_release(struct inode *inode, struct file *file) 2908 { 2909 struct seq_file *seq = file->private_data; 2910 struct user_namespace *ns = seq->private; 2911 int ret = single_release(inode, file); 2912 put_user_ns(ns); 2913 return ret; 2914 } 2915 2916 static const struct file_operations proc_setgroups_operations = { 2917 .open = proc_setgroups_open, 2918 .write = proc_setgroups_write, 2919 .read = seq_read, 2920 .llseek = seq_lseek, 2921 .release = proc_setgroups_release, 2922 }; 2923 #endif /* CONFIG_USER_NS */ 2924 2925 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2926 struct pid *pid, struct task_struct *task) 2927 { 2928 int err = lock_trace(task); 2929 if (!err) { 2930 seq_printf(m, "%08x\n", task->personality); 2931 unlock_trace(task); 2932 } 2933 return err; 2934 } 2935 2936 #ifdef CONFIG_LIVEPATCH 2937 static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns, 2938 struct pid *pid, struct task_struct *task) 2939 { 2940 seq_printf(m, "%d\n", task->patch_state); 2941 return 0; 2942 } 2943 #endif /* CONFIG_LIVEPATCH */ 2944 2945 #ifdef CONFIG_STACKLEAK_METRICS 2946 static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns, 2947 struct pid *pid, struct task_struct *task) 2948 { 2949 unsigned long prev_depth = THREAD_SIZE - 2950 (task->prev_lowest_stack & (THREAD_SIZE - 1)); 2951 unsigned long depth = THREAD_SIZE - 2952 (task->lowest_stack & (THREAD_SIZE - 1)); 2953 2954 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n", 2955 prev_depth, depth); 2956 return 0; 2957 } 2958 #endif /* CONFIG_STACKLEAK_METRICS */ 2959 2960 /* 2961 * Thread groups 2962 */ 2963 static const struct file_operations proc_task_operations; 2964 static const struct inode_operations proc_task_inode_operations; 2965 2966 static const struct pid_entry tgid_base_stuff[] = { 2967 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2968 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2969 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 2970 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2971 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2972 #ifdef CONFIG_NET 2973 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2974 #endif 2975 REG("environ", S_IRUSR, proc_environ_operations), 2976 REG("auxv", S_IRUSR, proc_auxv_operations), 2977 ONE("status", S_IRUGO, proc_pid_status), 2978 ONE("personality", S_IRUSR, proc_pid_personality), 2979 ONE("limits", S_IRUGO, proc_pid_limits), 2980 #ifdef CONFIG_SCHED_DEBUG 2981 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2982 #endif 2983 #ifdef CONFIG_SCHED_AUTOGROUP 2984 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2985 #endif 2986 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2987 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2988 ONE("syscall", S_IRUSR, proc_pid_syscall), 2989 #endif 2990 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 2991 ONE("stat", S_IRUGO, proc_tgid_stat), 2992 ONE("statm", S_IRUGO, proc_pid_statm), 2993 REG("maps", S_IRUGO, proc_pid_maps_operations), 2994 #ifdef CONFIG_NUMA 2995 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 2996 #endif 2997 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2998 LNK("cwd", proc_cwd_link), 2999 LNK("root", proc_root_link), 3000 LNK("exe", proc_exe_link), 3001 REG("mounts", S_IRUGO, proc_mounts_operations), 3002 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3003 REG("mountstats", S_IRUSR, proc_mountstats_operations), 3004 #ifdef CONFIG_PROC_PAGE_MONITOR 3005 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3006 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 3007 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations), 3008 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3009 #endif 3010 #ifdef CONFIG_SECURITY 3011 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3012 #endif 3013 #ifdef CONFIG_KALLSYMS 3014 ONE("wchan", S_IRUGO, proc_pid_wchan), 3015 #endif 3016 #ifdef CONFIG_STACKTRACE 3017 ONE("stack", S_IRUSR, proc_pid_stack), 3018 #endif 3019 #ifdef CONFIG_SCHED_INFO 3020 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 3021 #endif 3022 #ifdef CONFIG_LATENCYTOP 3023 REG("latency", S_IRUGO, proc_lstats_operations), 3024 #endif 3025 #ifdef CONFIG_PROC_PID_CPUSET 3026 ONE("cpuset", S_IRUGO, proc_cpuset_show), 3027 #endif 3028 #ifdef CONFIG_CGROUPS 3029 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3030 #endif 3031 ONE("oom_score", S_IRUGO, proc_oom_score), 3032 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3033 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3034 #ifdef CONFIG_AUDIT 3035 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3036 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3037 #endif 3038 #ifdef CONFIG_FAULT_INJECTION 3039 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3040 REG("fail-nth", 0644, proc_fail_nth_operations), 3041 #endif 3042 #ifdef CONFIG_ELF_CORE 3043 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 3044 #endif 3045 #ifdef CONFIG_TASK_IO_ACCOUNTING 3046 ONE("io", S_IRUSR, proc_tgid_io_accounting), 3047 #endif 3048 #ifdef CONFIG_USER_NS 3049 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3050 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3051 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3052 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3053 #endif 3054 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS) 3055 REG("timers", S_IRUGO, proc_timers_operations), 3056 #endif 3057 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations), 3058 #ifdef CONFIG_LIVEPATCH 3059 ONE("patch_state", S_IRUSR, proc_pid_patch_state), 3060 #endif 3061 #ifdef CONFIG_STACKLEAK_METRICS 3062 ONE("stack_depth", S_IRUGO, proc_stack_depth), 3063 #endif 3064 }; 3065 3066 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) 3067 { 3068 return proc_pident_readdir(file, ctx, 3069 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3070 } 3071 3072 static const struct file_operations proc_tgid_base_operations = { 3073 .read = generic_read_dir, 3074 .iterate_shared = proc_tgid_base_readdir, 3075 .llseek = generic_file_llseek, 3076 }; 3077 3078 struct pid *tgid_pidfd_to_pid(const struct file *file) 3079 { 3080 if (!d_is_dir(file->f_path.dentry) || 3081 (file->f_op != &proc_tgid_base_operations)) 3082 return ERR_PTR(-EBADF); 3083 3084 return proc_pid(file_inode(file)); 3085 } 3086 3087 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3088 { 3089 return proc_pident_lookup(dir, dentry, 3090 tgid_base_stuff, 3091 tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff)); 3092 } 3093 3094 static const struct inode_operations proc_tgid_base_inode_operations = { 3095 .lookup = proc_tgid_base_lookup, 3096 .getattr = pid_getattr, 3097 .setattr = proc_setattr, 3098 .permission = proc_pid_permission, 3099 }; 3100 3101 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 3102 { 3103 struct dentry *dentry, *leader, *dir; 3104 char buf[10 + 1]; 3105 struct qstr name; 3106 3107 name.name = buf; 3108 name.len = snprintf(buf, sizeof(buf), "%u", pid); 3109 /* no ->d_hash() rejects on procfs */ 3110 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 3111 if (dentry) { 3112 d_invalidate(dentry); 3113 dput(dentry); 3114 } 3115 3116 if (pid == tgid) 3117 return; 3118 3119 name.name = buf; 3120 name.len = snprintf(buf, sizeof(buf), "%u", tgid); 3121 leader = d_hash_and_lookup(mnt->mnt_root, &name); 3122 if (!leader) 3123 goto out; 3124 3125 name.name = "task"; 3126 name.len = strlen(name.name); 3127 dir = d_hash_and_lookup(leader, &name); 3128 if (!dir) 3129 goto out_put_leader; 3130 3131 name.name = buf; 3132 name.len = snprintf(buf, sizeof(buf), "%u", pid); 3133 dentry = d_hash_and_lookup(dir, &name); 3134 if (dentry) { 3135 d_invalidate(dentry); 3136 dput(dentry); 3137 } 3138 3139 dput(dir); 3140 out_put_leader: 3141 dput(leader); 3142 out: 3143 return; 3144 } 3145 3146 /** 3147 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 3148 * @task: task that should be flushed. 3149 * 3150 * When flushing dentries from proc, one needs to flush them from global 3151 * proc (proc_mnt) and from all the namespaces' procs this task was seen 3152 * in. This call is supposed to do all of this job. 3153 * 3154 * Looks in the dcache for 3155 * /proc/@pid 3156 * /proc/@tgid/task/@pid 3157 * if either directory is present flushes it and all of it'ts children 3158 * from the dcache. 3159 * 3160 * It is safe and reasonable to cache /proc entries for a task until 3161 * that task exits. After that they just clog up the dcache with 3162 * useless entries, possibly causing useful dcache entries to be 3163 * flushed instead. This routine is proved to flush those useless 3164 * dcache entries at process exit time. 3165 * 3166 * NOTE: This routine is just an optimization so it does not guarantee 3167 * that no dcache entries will exist at process exit time it 3168 * just makes it very unlikely that any will persist. 3169 */ 3170 3171 void proc_flush_task(struct task_struct *task) 3172 { 3173 int i; 3174 struct pid *pid, *tgid; 3175 struct upid *upid; 3176 3177 pid = task_pid(task); 3178 tgid = task_tgid(task); 3179 3180 for (i = 0; i <= pid->level; i++) { 3181 upid = &pid->numbers[i]; 3182 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3183 tgid->numbers[i].nr); 3184 } 3185 } 3186 3187 static struct dentry *proc_pid_instantiate(struct dentry * dentry, 3188 struct task_struct *task, const void *ptr) 3189 { 3190 struct inode *inode; 3191 3192 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3193 if (!inode) 3194 return ERR_PTR(-ENOENT); 3195 3196 inode->i_op = &proc_tgid_base_inode_operations; 3197 inode->i_fop = &proc_tgid_base_operations; 3198 inode->i_flags|=S_IMMUTABLE; 3199 3200 set_nlink(inode, nlink_tgid); 3201 pid_update_inode(task, inode); 3202 3203 d_set_d_op(dentry, &pid_dentry_operations); 3204 return d_splice_alias(inode, dentry); 3205 } 3206 3207 struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags) 3208 { 3209 struct task_struct *task; 3210 unsigned tgid; 3211 struct pid_namespace *ns; 3212 struct dentry *result = ERR_PTR(-ENOENT); 3213 3214 tgid = name_to_int(&dentry->d_name); 3215 if (tgid == ~0U) 3216 goto out; 3217 3218 ns = dentry->d_sb->s_fs_info; 3219 rcu_read_lock(); 3220 task = find_task_by_pid_ns(tgid, ns); 3221 if (task) 3222 get_task_struct(task); 3223 rcu_read_unlock(); 3224 if (!task) 3225 goto out; 3226 3227 result = proc_pid_instantiate(dentry, task, NULL); 3228 put_task_struct(task); 3229 out: 3230 return result; 3231 } 3232 3233 /* 3234 * Find the first task with tgid >= tgid 3235 * 3236 */ 3237 struct tgid_iter { 3238 unsigned int tgid; 3239 struct task_struct *task; 3240 }; 3241 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3242 { 3243 struct pid *pid; 3244 3245 if (iter.task) 3246 put_task_struct(iter.task); 3247 rcu_read_lock(); 3248 retry: 3249 iter.task = NULL; 3250 pid = find_ge_pid(iter.tgid, ns); 3251 if (pid) { 3252 iter.tgid = pid_nr_ns(pid, ns); 3253 iter.task = pid_task(pid, PIDTYPE_PID); 3254 /* What we to know is if the pid we have find is the 3255 * pid of a thread_group_leader. Testing for task 3256 * being a thread_group_leader is the obvious thing 3257 * todo but there is a window when it fails, due to 3258 * the pid transfer logic in de_thread. 3259 * 3260 * So we perform the straight forward test of seeing 3261 * if the pid we have found is the pid of a thread 3262 * group leader, and don't worry if the task we have 3263 * found doesn't happen to be a thread group leader. 3264 * As we don't care in the case of readdir. 3265 */ 3266 if (!iter.task || !has_group_leader_pid(iter.task)) { 3267 iter.tgid += 1; 3268 goto retry; 3269 } 3270 get_task_struct(iter.task); 3271 } 3272 rcu_read_unlock(); 3273 return iter; 3274 } 3275 3276 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2) 3277 3278 /* for the /proc/ directory itself, after non-process stuff has been done */ 3279 int proc_pid_readdir(struct file *file, struct dir_context *ctx) 3280 { 3281 struct tgid_iter iter; 3282 struct pid_namespace *ns = proc_pid_ns(file_inode(file)); 3283 loff_t pos = ctx->pos; 3284 3285 if (pos >= PID_MAX_LIMIT + TGID_OFFSET) 3286 return 0; 3287 3288 if (pos == TGID_OFFSET - 2) { 3289 struct inode *inode = d_inode(ns->proc_self); 3290 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) 3291 return 0; 3292 ctx->pos = pos = pos + 1; 3293 } 3294 if (pos == TGID_OFFSET - 1) { 3295 struct inode *inode = d_inode(ns->proc_thread_self); 3296 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) 3297 return 0; 3298 ctx->pos = pos = pos + 1; 3299 } 3300 iter.tgid = pos - TGID_OFFSET; 3301 iter.task = NULL; 3302 for (iter = next_tgid(ns, iter); 3303 iter.task; 3304 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3305 char name[10 + 1]; 3306 unsigned int len; 3307 3308 cond_resched(); 3309 if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE)) 3310 continue; 3311 3312 len = snprintf(name, sizeof(name), "%u", iter.tgid); 3313 ctx->pos = iter.tgid + TGID_OFFSET; 3314 if (!proc_fill_cache(file, ctx, name, len, 3315 proc_pid_instantiate, iter.task, NULL)) { 3316 put_task_struct(iter.task); 3317 return 0; 3318 } 3319 } 3320 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET; 3321 return 0; 3322 } 3323 3324 /* 3325 * proc_tid_comm_permission is a special permission function exclusively 3326 * used for the node /proc/<pid>/task/<tid>/comm. 3327 * It bypasses generic permission checks in the case where a task of the same 3328 * task group attempts to access the node. 3329 * The rationale behind this is that glibc and bionic access this node for 3330 * cross thread naming (pthread_set/getname_np(!self)). However, if 3331 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0, 3332 * which locks out the cross thread naming implementation. 3333 * This function makes sure that the node is always accessible for members of 3334 * same thread group. 3335 */ 3336 static int proc_tid_comm_permission(struct inode *inode, int mask) 3337 { 3338 bool is_same_tgroup; 3339 struct task_struct *task; 3340 3341 task = get_proc_task(inode); 3342 if (!task) 3343 return -ESRCH; 3344 is_same_tgroup = same_thread_group(current, task); 3345 put_task_struct(task); 3346 3347 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) { 3348 /* This file (/proc/<pid>/task/<tid>/comm) can always be 3349 * read or written by the members of the corresponding 3350 * thread group. 3351 */ 3352 return 0; 3353 } 3354 3355 return generic_permission(inode, mask); 3356 } 3357 3358 static const struct inode_operations proc_tid_comm_inode_operations = { 3359 .permission = proc_tid_comm_permission, 3360 }; 3361 3362 /* 3363 * Tasks 3364 */ 3365 static const struct pid_entry tid_base_stuff[] = { 3366 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3367 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3368 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3369 #ifdef CONFIG_NET 3370 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3371 #endif 3372 REG("environ", S_IRUSR, proc_environ_operations), 3373 REG("auxv", S_IRUSR, proc_auxv_operations), 3374 ONE("status", S_IRUGO, proc_pid_status), 3375 ONE("personality", S_IRUSR, proc_pid_personality), 3376 ONE("limits", S_IRUGO, proc_pid_limits), 3377 #ifdef CONFIG_SCHED_DEBUG 3378 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3379 #endif 3380 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR, 3381 &proc_tid_comm_inode_operations, 3382 &proc_pid_set_comm_operations, {}), 3383 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3384 ONE("syscall", S_IRUSR, proc_pid_syscall), 3385 #endif 3386 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 3387 ONE("stat", S_IRUGO, proc_tid_stat), 3388 ONE("statm", S_IRUGO, proc_pid_statm), 3389 REG("maps", S_IRUGO, proc_pid_maps_operations), 3390 #ifdef CONFIG_PROC_CHILDREN 3391 REG("children", S_IRUGO, proc_tid_children_operations), 3392 #endif 3393 #ifdef CONFIG_NUMA 3394 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 3395 #endif 3396 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3397 LNK("cwd", proc_cwd_link), 3398 LNK("root", proc_root_link), 3399 LNK("exe", proc_exe_link), 3400 REG("mounts", S_IRUGO, proc_mounts_operations), 3401 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3402 #ifdef CONFIG_PROC_PAGE_MONITOR 3403 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3404 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 3405 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations), 3406 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3407 #endif 3408 #ifdef CONFIG_SECURITY 3409 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3410 #endif 3411 #ifdef CONFIG_KALLSYMS 3412 ONE("wchan", S_IRUGO, proc_pid_wchan), 3413 #endif 3414 #ifdef CONFIG_STACKTRACE 3415 ONE("stack", S_IRUSR, proc_pid_stack), 3416 #endif 3417 #ifdef CONFIG_SCHED_INFO 3418 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 3419 #endif 3420 #ifdef CONFIG_LATENCYTOP 3421 REG("latency", S_IRUGO, proc_lstats_operations), 3422 #endif 3423 #ifdef CONFIG_PROC_PID_CPUSET 3424 ONE("cpuset", S_IRUGO, proc_cpuset_show), 3425 #endif 3426 #ifdef CONFIG_CGROUPS 3427 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3428 #endif 3429 ONE("oom_score", S_IRUGO, proc_oom_score), 3430 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3431 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3432 #ifdef CONFIG_AUDIT 3433 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3434 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3435 #endif 3436 #ifdef CONFIG_FAULT_INJECTION 3437 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3438 REG("fail-nth", 0644, proc_fail_nth_operations), 3439 #endif 3440 #ifdef CONFIG_TASK_IO_ACCOUNTING 3441 ONE("io", S_IRUSR, proc_tid_io_accounting), 3442 #endif 3443 #ifdef CONFIG_USER_NS 3444 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3445 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3446 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3447 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3448 #endif 3449 #ifdef CONFIG_LIVEPATCH 3450 ONE("patch_state", S_IRUSR, proc_pid_patch_state), 3451 #endif 3452 }; 3453 3454 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx) 3455 { 3456 return proc_pident_readdir(file, ctx, 3457 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3458 } 3459 3460 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3461 { 3462 return proc_pident_lookup(dir, dentry, 3463 tid_base_stuff, 3464 tid_base_stuff + ARRAY_SIZE(tid_base_stuff)); 3465 } 3466 3467 static const struct file_operations proc_tid_base_operations = { 3468 .read = generic_read_dir, 3469 .iterate_shared = proc_tid_base_readdir, 3470 .llseek = generic_file_llseek, 3471 }; 3472 3473 static const struct inode_operations proc_tid_base_inode_operations = { 3474 .lookup = proc_tid_base_lookup, 3475 .getattr = pid_getattr, 3476 .setattr = proc_setattr, 3477 }; 3478 3479 static struct dentry *proc_task_instantiate(struct dentry *dentry, 3480 struct task_struct *task, const void *ptr) 3481 { 3482 struct inode *inode; 3483 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3484 if (!inode) 3485 return ERR_PTR(-ENOENT); 3486 3487 inode->i_op = &proc_tid_base_inode_operations; 3488 inode->i_fop = &proc_tid_base_operations; 3489 inode->i_flags |= S_IMMUTABLE; 3490 3491 set_nlink(inode, nlink_tid); 3492 pid_update_inode(task, inode); 3493 3494 d_set_d_op(dentry, &pid_dentry_operations); 3495 return d_splice_alias(inode, dentry); 3496 } 3497 3498 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3499 { 3500 struct task_struct *task; 3501 struct task_struct *leader = get_proc_task(dir); 3502 unsigned tid; 3503 struct pid_namespace *ns; 3504 struct dentry *result = ERR_PTR(-ENOENT); 3505 3506 if (!leader) 3507 goto out_no_task; 3508 3509 tid = name_to_int(&dentry->d_name); 3510 if (tid == ~0U) 3511 goto out; 3512 3513 ns = dentry->d_sb->s_fs_info; 3514 rcu_read_lock(); 3515 task = find_task_by_pid_ns(tid, ns); 3516 if (task) 3517 get_task_struct(task); 3518 rcu_read_unlock(); 3519 if (!task) 3520 goto out; 3521 if (!same_thread_group(leader, task)) 3522 goto out_drop_task; 3523 3524 result = proc_task_instantiate(dentry, task, NULL); 3525 out_drop_task: 3526 put_task_struct(task); 3527 out: 3528 put_task_struct(leader); 3529 out_no_task: 3530 return result; 3531 } 3532 3533 /* 3534 * Find the first tid of a thread group to return to user space. 3535 * 3536 * Usually this is just the thread group leader, but if the users 3537 * buffer was too small or there was a seek into the middle of the 3538 * directory we have more work todo. 3539 * 3540 * In the case of a short read we start with find_task_by_pid. 3541 * 3542 * In the case of a seek we start with the leader and walk nr 3543 * threads past it. 3544 */ 3545 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos, 3546 struct pid_namespace *ns) 3547 { 3548 struct task_struct *pos, *task; 3549 unsigned long nr = f_pos; 3550 3551 if (nr != f_pos) /* 32bit overflow? */ 3552 return NULL; 3553 3554 rcu_read_lock(); 3555 task = pid_task(pid, PIDTYPE_PID); 3556 if (!task) 3557 goto fail; 3558 3559 /* Attempt to start with the tid of a thread */ 3560 if (tid && nr) { 3561 pos = find_task_by_pid_ns(tid, ns); 3562 if (pos && same_thread_group(pos, task)) 3563 goto found; 3564 } 3565 3566 /* If nr exceeds the number of threads there is nothing todo */ 3567 if (nr >= get_nr_threads(task)) 3568 goto fail; 3569 3570 /* If we haven't found our starting place yet start 3571 * with the leader and walk nr threads forward. 3572 */ 3573 pos = task = task->group_leader; 3574 do { 3575 if (!nr--) 3576 goto found; 3577 } while_each_thread(task, pos); 3578 fail: 3579 pos = NULL; 3580 goto out; 3581 found: 3582 get_task_struct(pos); 3583 out: 3584 rcu_read_unlock(); 3585 return pos; 3586 } 3587 3588 /* 3589 * Find the next thread in the thread list. 3590 * Return NULL if there is an error or no next thread. 3591 * 3592 * The reference to the input task_struct is released. 3593 */ 3594 static struct task_struct *next_tid(struct task_struct *start) 3595 { 3596 struct task_struct *pos = NULL; 3597 rcu_read_lock(); 3598 if (pid_alive(start)) { 3599 pos = next_thread(start); 3600 if (thread_group_leader(pos)) 3601 pos = NULL; 3602 else 3603 get_task_struct(pos); 3604 } 3605 rcu_read_unlock(); 3606 put_task_struct(start); 3607 return pos; 3608 } 3609 3610 /* for the /proc/TGID/task/ directories */ 3611 static int proc_task_readdir(struct file *file, struct dir_context *ctx) 3612 { 3613 struct inode *inode = file_inode(file); 3614 struct task_struct *task; 3615 struct pid_namespace *ns; 3616 int tid; 3617 3618 if (proc_inode_is_dead(inode)) 3619 return -ENOENT; 3620 3621 if (!dir_emit_dots(file, ctx)) 3622 return 0; 3623 3624 /* f_version caches the tgid value that the last readdir call couldn't 3625 * return. lseek aka telldir automagically resets f_version to 0. 3626 */ 3627 ns = proc_pid_ns(inode); 3628 tid = (int)file->f_version; 3629 file->f_version = 0; 3630 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); 3631 task; 3632 task = next_tid(task), ctx->pos++) { 3633 char name[10 + 1]; 3634 unsigned int len; 3635 tid = task_pid_nr_ns(task, ns); 3636 len = snprintf(name, sizeof(name), "%u", tid); 3637 if (!proc_fill_cache(file, ctx, name, len, 3638 proc_task_instantiate, task, NULL)) { 3639 /* returning this tgid failed, save it as the first 3640 * pid for the next readir call */ 3641 file->f_version = (u64)tid; 3642 put_task_struct(task); 3643 break; 3644 } 3645 } 3646 3647 return 0; 3648 } 3649 3650 static int proc_task_getattr(const struct path *path, struct kstat *stat, 3651 u32 request_mask, unsigned int query_flags) 3652 { 3653 struct inode *inode = d_inode(path->dentry); 3654 struct task_struct *p = get_proc_task(inode); 3655 generic_fillattr(inode, stat); 3656 3657 if (p) { 3658 stat->nlink += get_nr_threads(p); 3659 put_task_struct(p); 3660 } 3661 3662 return 0; 3663 } 3664 3665 static const struct inode_operations proc_task_inode_operations = { 3666 .lookup = proc_task_lookup, 3667 .getattr = proc_task_getattr, 3668 .setattr = proc_setattr, 3669 .permission = proc_pid_permission, 3670 }; 3671 3672 static const struct file_operations proc_task_operations = { 3673 .read = generic_read_dir, 3674 .iterate_shared = proc_task_readdir, 3675 .llseek = generic_file_llseek, 3676 }; 3677 3678 void __init set_proc_pid_nlink(void) 3679 { 3680 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3681 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3682 } 3683