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, totalpages) * 1000 / totalpages; 536 seq_printf(m, "%lu\n", points); 537 538 return 0; 539 } 540 541 struct limit_names { 542 const char *name; 543 const char *unit; 544 }; 545 546 static const struct limit_names lnames[RLIM_NLIMITS] = { 547 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 548 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 549 [RLIMIT_DATA] = {"Max data size", "bytes"}, 550 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 551 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 552 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 553 [RLIMIT_NPROC] = {"Max processes", "processes"}, 554 [RLIMIT_NOFILE] = {"Max open files", "files"}, 555 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 556 [RLIMIT_AS] = {"Max address space", "bytes"}, 557 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 558 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 559 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 560 [RLIMIT_NICE] = {"Max nice priority", NULL}, 561 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 562 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 563 }; 564 565 /* Display limits for a process */ 566 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns, 567 struct pid *pid, struct task_struct *task) 568 { 569 unsigned int i; 570 unsigned long flags; 571 572 struct rlimit rlim[RLIM_NLIMITS]; 573 574 if (!lock_task_sighand(task, &flags)) 575 return 0; 576 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 577 unlock_task_sighand(task, &flags); 578 579 /* 580 * print the file header 581 */ 582 seq_puts(m, "Limit " 583 "Soft Limit " 584 "Hard Limit " 585 "Units \n"); 586 587 for (i = 0; i < RLIM_NLIMITS; i++) { 588 if (rlim[i].rlim_cur == RLIM_INFINITY) 589 seq_printf(m, "%-25s %-20s ", 590 lnames[i].name, "unlimited"); 591 else 592 seq_printf(m, "%-25s %-20lu ", 593 lnames[i].name, rlim[i].rlim_cur); 594 595 if (rlim[i].rlim_max == RLIM_INFINITY) 596 seq_printf(m, "%-20s ", "unlimited"); 597 else 598 seq_printf(m, "%-20lu ", rlim[i].rlim_max); 599 600 if (lnames[i].unit) 601 seq_printf(m, "%-10s\n", lnames[i].unit); 602 else 603 seq_putc(m, '\n'); 604 } 605 606 return 0; 607 } 608 609 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 610 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns, 611 struct pid *pid, struct task_struct *task) 612 { 613 struct syscall_info info; 614 u64 *args = &info.data.args[0]; 615 int res; 616 617 res = lock_trace(task); 618 if (res) 619 return res; 620 621 if (task_current_syscall(task, &info)) 622 seq_puts(m, "running\n"); 623 else if (info.data.nr < 0) 624 seq_printf(m, "%d 0x%llx 0x%llx\n", 625 info.data.nr, info.sp, info.data.instruction_pointer); 626 else 627 seq_printf(m, 628 "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n", 629 info.data.nr, 630 args[0], args[1], args[2], args[3], args[4], args[5], 631 info.sp, info.data.instruction_pointer); 632 unlock_trace(task); 633 634 return 0; 635 } 636 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 637 638 /************************************************************************/ 639 /* Here the fs part begins */ 640 /************************************************************************/ 641 642 /* permission checks */ 643 static int proc_fd_access_allowed(struct inode *inode) 644 { 645 struct task_struct *task; 646 int allowed = 0; 647 /* Allow access to a task's file descriptors if it is us or we 648 * may use ptrace attach to the process and find out that 649 * information. 650 */ 651 task = get_proc_task(inode); 652 if (task) { 653 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 654 put_task_struct(task); 655 } 656 return allowed; 657 } 658 659 int proc_setattr(struct dentry *dentry, struct iattr *attr) 660 { 661 int error; 662 struct inode *inode = d_inode(dentry); 663 664 if (attr->ia_valid & ATTR_MODE) 665 return -EPERM; 666 667 error = setattr_prepare(dentry, attr); 668 if (error) 669 return error; 670 671 setattr_copy(inode, attr); 672 mark_inode_dirty(inode); 673 return 0; 674 } 675 676 /* 677 * May current process learn task's sched/cmdline info (for hide_pid_min=1) 678 * or euid/egid (for hide_pid_min=2)? 679 */ 680 static bool has_pid_permissions(struct pid_namespace *pid, 681 struct task_struct *task, 682 int hide_pid_min) 683 { 684 if (pid->hide_pid < hide_pid_min) 685 return true; 686 if (in_group_p(pid->pid_gid)) 687 return true; 688 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 689 } 690 691 692 static int proc_pid_permission(struct inode *inode, int mask) 693 { 694 struct pid_namespace *pid = proc_pid_ns(inode); 695 struct task_struct *task; 696 bool has_perms; 697 698 task = get_proc_task(inode); 699 if (!task) 700 return -ESRCH; 701 has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS); 702 put_task_struct(task); 703 704 if (!has_perms) { 705 if (pid->hide_pid == HIDEPID_INVISIBLE) { 706 /* 707 * Let's make getdents(), stat(), and open() 708 * consistent with each other. If a process 709 * may not stat() a file, it shouldn't be seen 710 * in procfs at all. 711 */ 712 return -ENOENT; 713 } 714 715 return -EPERM; 716 } 717 return generic_permission(inode, mask); 718 } 719 720 721 722 static const struct inode_operations proc_def_inode_operations = { 723 .setattr = proc_setattr, 724 }; 725 726 static int proc_single_show(struct seq_file *m, void *v) 727 { 728 struct inode *inode = m->private; 729 struct pid_namespace *ns = proc_pid_ns(inode); 730 struct pid *pid = proc_pid(inode); 731 struct task_struct *task; 732 int ret; 733 734 task = get_pid_task(pid, PIDTYPE_PID); 735 if (!task) 736 return -ESRCH; 737 738 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 739 740 put_task_struct(task); 741 return ret; 742 } 743 744 static int proc_single_open(struct inode *inode, struct file *filp) 745 { 746 return single_open(filp, proc_single_show, inode); 747 } 748 749 static const struct file_operations proc_single_file_operations = { 750 .open = proc_single_open, 751 .read = seq_read, 752 .llseek = seq_lseek, 753 .release = single_release, 754 }; 755 756 757 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode) 758 { 759 struct task_struct *task = get_proc_task(inode); 760 struct mm_struct *mm = ERR_PTR(-ESRCH); 761 762 if (task) { 763 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS); 764 put_task_struct(task); 765 766 if (!IS_ERR_OR_NULL(mm)) { 767 /* ensure this mm_struct can't be freed */ 768 mmgrab(mm); 769 /* but do not pin its memory */ 770 mmput(mm); 771 } 772 } 773 774 return mm; 775 } 776 777 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) 778 { 779 struct mm_struct *mm = proc_mem_open(inode, mode); 780 781 if (IS_ERR(mm)) 782 return PTR_ERR(mm); 783 784 file->private_data = mm; 785 return 0; 786 } 787 788 static int mem_open(struct inode *inode, struct file *file) 789 { 790 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH); 791 792 /* OK to pass negative loff_t, we can catch out-of-range */ 793 file->f_mode |= FMODE_UNSIGNED_OFFSET; 794 795 return ret; 796 } 797 798 static ssize_t mem_rw(struct file *file, char __user *buf, 799 size_t count, loff_t *ppos, int write) 800 { 801 struct mm_struct *mm = file->private_data; 802 unsigned long addr = *ppos; 803 ssize_t copied; 804 char *page; 805 unsigned int flags; 806 807 if (!mm) 808 return 0; 809 810 page = (char *)__get_free_page(GFP_KERNEL); 811 if (!page) 812 return -ENOMEM; 813 814 copied = 0; 815 if (!mmget_not_zero(mm)) 816 goto free; 817 818 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0); 819 820 while (count > 0) { 821 int this_len = min_t(int, count, PAGE_SIZE); 822 823 if (write && copy_from_user(page, buf, this_len)) { 824 copied = -EFAULT; 825 break; 826 } 827 828 this_len = access_remote_vm(mm, addr, page, this_len, flags); 829 if (!this_len) { 830 if (!copied) 831 copied = -EIO; 832 break; 833 } 834 835 if (!write && copy_to_user(buf, page, this_len)) { 836 copied = -EFAULT; 837 break; 838 } 839 840 buf += this_len; 841 addr += this_len; 842 copied += this_len; 843 count -= this_len; 844 } 845 *ppos = addr; 846 847 mmput(mm); 848 free: 849 free_page((unsigned long) page); 850 return copied; 851 } 852 853 static ssize_t mem_read(struct file *file, char __user *buf, 854 size_t count, loff_t *ppos) 855 { 856 return mem_rw(file, buf, count, ppos, 0); 857 } 858 859 static ssize_t mem_write(struct file *file, const char __user *buf, 860 size_t count, loff_t *ppos) 861 { 862 return mem_rw(file, (char __user*)buf, count, ppos, 1); 863 } 864 865 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 866 { 867 switch (orig) { 868 case 0: 869 file->f_pos = offset; 870 break; 871 case 1: 872 file->f_pos += offset; 873 break; 874 default: 875 return -EINVAL; 876 } 877 force_successful_syscall_return(); 878 return file->f_pos; 879 } 880 881 static int mem_release(struct inode *inode, struct file *file) 882 { 883 struct mm_struct *mm = file->private_data; 884 if (mm) 885 mmdrop(mm); 886 return 0; 887 } 888 889 static const struct file_operations proc_mem_operations = { 890 .llseek = mem_lseek, 891 .read = mem_read, 892 .write = mem_write, 893 .open = mem_open, 894 .release = mem_release, 895 }; 896 897 static int environ_open(struct inode *inode, struct file *file) 898 { 899 return __mem_open(inode, file, PTRACE_MODE_READ); 900 } 901 902 static ssize_t environ_read(struct file *file, char __user *buf, 903 size_t count, loff_t *ppos) 904 { 905 char *page; 906 unsigned long src = *ppos; 907 int ret = 0; 908 struct mm_struct *mm = file->private_data; 909 unsigned long env_start, env_end; 910 911 /* Ensure the process spawned far enough to have an environment. */ 912 if (!mm || !mm->env_end) 913 return 0; 914 915 page = (char *)__get_free_page(GFP_KERNEL); 916 if (!page) 917 return -ENOMEM; 918 919 ret = 0; 920 if (!mmget_not_zero(mm)) 921 goto free; 922 923 spin_lock(&mm->arg_lock); 924 env_start = mm->env_start; 925 env_end = mm->env_end; 926 spin_unlock(&mm->arg_lock); 927 928 while (count > 0) { 929 size_t this_len, max_len; 930 int retval; 931 932 if (src >= (env_end - env_start)) 933 break; 934 935 this_len = env_end - (env_start + src); 936 937 max_len = min_t(size_t, PAGE_SIZE, count); 938 this_len = min(max_len, this_len); 939 940 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON); 941 942 if (retval <= 0) { 943 ret = retval; 944 break; 945 } 946 947 if (copy_to_user(buf, page, retval)) { 948 ret = -EFAULT; 949 break; 950 } 951 952 ret += retval; 953 src += retval; 954 buf += retval; 955 count -= retval; 956 } 957 *ppos = src; 958 mmput(mm); 959 960 free: 961 free_page((unsigned long) page); 962 return ret; 963 } 964 965 static const struct file_operations proc_environ_operations = { 966 .open = environ_open, 967 .read = environ_read, 968 .llseek = generic_file_llseek, 969 .release = mem_release, 970 }; 971 972 static int auxv_open(struct inode *inode, struct file *file) 973 { 974 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS); 975 } 976 977 static ssize_t auxv_read(struct file *file, char __user *buf, 978 size_t count, loff_t *ppos) 979 { 980 struct mm_struct *mm = file->private_data; 981 unsigned int nwords = 0; 982 983 if (!mm) 984 return 0; 985 do { 986 nwords += 2; 987 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 988 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv, 989 nwords * sizeof(mm->saved_auxv[0])); 990 } 991 992 static const struct file_operations proc_auxv_operations = { 993 .open = auxv_open, 994 .read = auxv_read, 995 .llseek = generic_file_llseek, 996 .release = mem_release, 997 }; 998 999 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count, 1000 loff_t *ppos) 1001 { 1002 struct task_struct *task = get_proc_task(file_inode(file)); 1003 char buffer[PROC_NUMBUF]; 1004 int oom_adj = OOM_ADJUST_MIN; 1005 size_t len; 1006 1007 if (!task) 1008 return -ESRCH; 1009 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX) 1010 oom_adj = OOM_ADJUST_MAX; 1011 else 1012 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) / 1013 OOM_SCORE_ADJ_MAX; 1014 put_task_struct(task); 1015 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj); 1016 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1017 } 1018 1019 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy) 1020 { 1021 static DEFINE_MUTEX(oom_adj_mutex); 1022 struct mm_struct *mm = NULL; 1023 struct task_struct *task; 1024 int err = 0; 1025 1026 task = get_proc_task(file_inode(file)); 1027 if (!task) 1028 return -ESRCH; 1029 1030 mutex_lock(&oom_adj_mutex); 1031 if (legacy) { 1032 if (oom_adj < task->signal->oom_score_adj && 1033 !capable(CAP_SYS_RESOURCE)) { 1034 err = -EACCES; 1035 goto err_unlock; 1036 } 1037 /* 1038 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use 1039 * /proc/pid/oom_score_adj instead. 1040 */ 1041 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 1042 current->comm, task_pid_nr(current), task_pid_nr(task), 1043 task_pid_nr(task)); 1044 } else { 1045 if ((short)oom_adj < task->signal->oom_score_adj_min && 1046 !capable(CAP_SYS_RESOURCE)) { 1047 err = -EACCES; 1048 goto err_unlock; 1049 } 1050 } 1051 1052 /* 1053 * Make sure we will check other processes sharing the mm if this is 1054 * not vfrok which wants its own oom_score_adj. 1055 * pin the mm so it doesn't go away and get reused after task_unlock 1056 */ 1057 if (!task->vfork_done) { 1058 struct task_struct *p = find_lock_task_mm(task); 1059 1060 if (p) { 1061 if (atomic_read(&p->mm->mm_users) > 1) { 1062 mm = p->mm; 1063 mmgrab(mm); 1064 } 1065 task_unlock(p); 1066 } 1067 } 1068 1069 task->signal->oom_score_adj = oom_adj; 1070 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1071 task->signal->oom_score_adj_min = (short)oom_adj; 1072 trace_oom_score_adj_update(task); 1073 1074 if (mm) { 1075 struct task_struct *p; 1076 1077 rcu_read_lock(); 1078 for_each_process(p) { 1079 if (same_thread_group(task, p)) 1080 continue; 1081 1082 /* do not touch kernel threads or the global init */ 1083 if (p->flags & PF_KTHREAD || is_global_init(p)) 1084 continue; 1085 1086 task_lock(p); 1087 if (!p->vfork_done && process_shares_mm(p, mm)) { 1088 p->signal->oom_score_adj = oom_adj; 1089 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1090 p->signal->oom_score_adj_min = (short)oom_adj; 1091 } 1092 task_unlock(p); 1093 } 1094 rcu_read_unlock(); 1095 mmdrop(mm); 1096 } 1097 err_unlock: 1098 mutex_unlock(&oom_adj_mutex); 1099 put_task_struct(task); 1100 return err; 1101 } 1102 1103 /* 1104 * /proc/pid/oom_adj exists solely for backwards compatibility with previous 1105 * kernels. The effective policy is defined by oom_score_adj, which has a 1106 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly. 1107 * Values written to oom_adj are simply mapped linearly to oom_score_adj. 1108 * Processes that become oom disabled via oom_adj will still be oom disabled 1109 * with this implementation. 1110 * 1111 * oom_adj cannot be removed since existing userspace binaries use it. 1112 */ 1113 static ssize_t oom_adj_write(struct file *file, const char __user *buf, 1114 size_t count, loff_t *ppos) 1115 { 1116 char buffer[PROC_NUMBUF]; 1117 int oom_adj; 1118 int err; 1119 1120 memset(buffer, 0, sizeof(buffer)); 1121 if (count > sizeof(buffer) - 1) 1122 count = sizeof(buffer) - 1; 1123 if (copy_from_user(buffer, buf, count)) { 1124 err = -EFAULT; 1125 goto out; 1126 } 1127 1128 err = kstrtoint(strstrip(buffer), 0, &oom_adj); 1129 if (err) 1130 goto out; 1131 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) && 1132 oom_adj != OOM_DISABLE) { 1133 err = -EINVAL; 1134 goto out; 1135 } 1136 1137 /* 1138 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 1139 * value is always attainable. 1140 */ 1141 if (oom_adj == OOM_ADJUST_MAX) 1142 oom_adj = OOM_SCORE_ADJ_MAX; 1143 else 1144 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE; 1145 1146 err = __set_oom_adj(file, oom_adj, true); 1147 out: 1148 return err < 0 ? err : count; 1149 } 1150 1151 static const struct file_operations proc_oom_adj_operations = { 1152 .read = oom_adj_read, 1153 .write = oom_adj_write, 1154 .llseek = generic_file_llseek, 1155 }; 1156 1157 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 1158 size_t count, loff_t *ppos) 1159 { 1160 struct task_struct *task = get_proc_task(file_inode(file)); 1161 char buffer[PROC_NUMBUF]; 1162 short oom_score_adj = OOM_SCORE_ADJ_MIN; 1163 size_t len; 1164 1165 if (!task) 1166 return -ESRCH; 1167 oom_score_adj = task->signal->oom_score_adj; 1168 put_task_struct(task); 1169 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj); 1170 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1171 } 1172 1173 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1174 size_t count, loff_t *ppos) 1175 { 1176 char buffer[PROC_NUMBUF]; 1177 int oom_score_adj; 1178 int err; 1179 1180 memset(buffer, 0, sizeof(buffer)); 1181 if (count > sizeof(buffer) - 1) 1182 count = sizeof(buffer) - 1; 1183 if (copy_from_user(buffer, buf, count)) { 1184 err = -EFAULT; 1185 goto out; 1186 } 1187 1188 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 1189 if (err) 1190 goto out; 1191 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1192 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1193 err = -EINVAL; 1194 goto out; 1195 } 1196 1197 err = __set_oom_adj(file, oom_score_adj, false); 1198 out: 1199 return err < 0 ? err : count; 1200 } 1201 1202 static const struct file_operations proc_oom_score_adj_operations = { 1203 .read = oom_score_adj_read, 1204 .write = oom_score_adj_write, 1205 .llseek = default_llseek, 1206 }; 1207 1208 #ifdef CONFIG_AUDIT 1209 #define TMPBUFLEN 11 1210 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1211 size_t count, loff_t *ppos) 1212 { 1213 struct inode * inode = file_inode(file); 1214 struct task_struct *task = get_proc_task(inode); 1215 ssize_t length; 1216 char tmpbuf[TMPBUFLEN]; 1217 1218 if (!task) 1219 return -ESRCH; 1220 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1221 from_kuid(file->f_cred->user_ns, 1222 audit_get_loginuid(task))); 1223 put_task_struct(task); 1224 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1225 } 1226 1227 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1228 size_t count, loff_t *ppos) 1229 { 1230 struct inode * inode = file_inode(file); 1231 uid_t loginuid; 1232 kuid_t kloginuid; 1233 int rv; 1234 1235 rcu_read_lock(); 1236 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1237 rcu_read_unlock(); 1238 return -EPERM; 1239 } 1240 rcu_read_unlock(); 1241 1242 if (*ppos != 0) { 1243 /* No partial writes. */ 1244 return -EINVAL; 1245 } 1246 1247 rv = kstrtou32_from_user(buf, count, 10, &loginuid); 1248 if (rv < 0) 1249 return rv; 1250 1251 /* is userspace tring to explicitly UNSET the loginuid? */ 1252 if (loginuid == AUDIT_UID_UNSET) { 1253 kloginuid = INVALID_UID; 1254 } else { 1255 kloginuid = make_kuid(file->f_cred->user_ns, loginuid); 1256 if (!uid_valid(kloginuid)) 1257 return -EINVAL; 1258 } 1259 1260 rv = audit_set_loginuid(kloginuid); 1261 if (rv < 0) 1262 return rv; 1263 return count; 1264 } 1265 1266 static const struct file_operations proc_loginuid_operations = { 1267 .read = proc_loginuid_read, 1268 .write = proc_loginuid_write, 1269 .llseek = generic_file_llseek, 1270 }; 1271 1272 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1273 size_t count, loff_t *ppos) 1274 { 1275 struct inode * inode = file_inode(file); 1276 struct task_struct *task = get_proc_task(inode); 1277 ssize_t length; 1278 char tmpbuf[TMPBUFLEN]; 1279 1280 if (!task) 1281 return -ESRCH; 1282 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1283 audit_get_sessionid(task)); 1284 put_task_struct(task); 1285 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1286 } 1287 1288 static const struct file_operations proc_sessionid_operations = { 1289 .read = proc_sessionid_read, 1290 .llseek = generic_file_llseek, 1291 }; 1292 #endif 1293 1294 #ifdef CONFIG_FAULT_INJECTION 1295 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1296 size_t count, loff_t *ppos) 1297 { 1298 struct task_struct *task = get_proc_task(file_inode(file)); 1299 char buffer[PROC_NUMBUF]; 1300 size_t len; 1301 int make_it_fail; 1302 1303 if (!task) 1304 return -ESRCH; 1305 make_it_fail = task->make_it_fail; 1306 put_task_struct(task); 1307 1308 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1309 1310 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1311 } 1312 1313 static ssize_t proc_fault_inject_write(struct file * file, 1314 const char __user * buf, size_t count, loff_t *ppos) 1315 { 1316 struct task_struct *task; 1317 char buffer[PROC_NUMBUF]; 1318 int make_it_fail; 1319 int rv; 1320 1321 if (!capable(CAP_SYS_RESOURCE)) 1322 return -EPERM; 1323 memset(buffer, 0, sizeof(buffer)); 1324 if (count > sizeof(buffer) - 1) 1325 count = sizeof(buffer) - 1; 1326 if (copy_from_user(buffer, buf, count)) 1327 return -EFAULT; 1328 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail); 1329 if (rv < 0) 1330 return rv; 1331 if (make_it_fail < 0 || make_it_fail > 1) 1332 return -EINVAL; 1333 1334 task = get_proc_task(file_inode(file)); 1335 if (!task) 1336 return -ESRCH; 1337 task->make_it_fail = make_it_fail; 1338 put_task_struct(task); 1339 1340 return count; 1341 } 1342 1343 static const struct file_operations proc_fault_inject_operations = { 1344 .read = proc_fault_inject_read, 1345 .write = proc_fault_inject_write, 1346 .llseek = generic_file_llseek, 1347 }; 1348 1349 static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf, 1350 size_t count, loff_t *ppos) 1351 { 1352 struct task_struct *task; 1353 int err; 1354 unsigned int n; 1355 1356 err = kstrtouint_from_user(buf, count, 0, &n); 1357 if (err) 1358 return err; 1359 1360 task = get_proc_task(file_inode(file)); 1361 if (!task) 1362 return -ESRCH; 1363 task->fail_nth = n; 1364 put_task_struct(task); 1365 1366 return count; 1367 } 1368 1369 static ssize_t proc_fail_nth_read(struct file *file, char __user *buf, 1370 size_t count, loff_t *ppos) 1371 { 1372 struct task_struct *task; 1373 char numbuf[PROC_NUMBUF]; 1374 ssize_t len; 1375 1376 task = get_proc_task(file_inode(file)); 1377 if (!task) 1378 return -ESRCH; 1379 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth); 1380 put_task_struct(task); 1381 return simple_read_from_buffer(buf, count, ppos, numbuf, len); 1382 } 1383 1384 static const struct file_operations proc_fail_nth_operations = { 1385 .read = proc_fail_nth_read, 1386 .write = proc_fail_nth_write, 1387 }; 1388 #endif 1389 1390 1391 #ifdef CONFIG_SCHED_DEBUG 1392 /* 1393 * Print out various scheduling related per-task fields: 1394 */ 1395 static int sched_show(struct seq_file *m, void *v) 1396 { 1397 struct inode *inode = m->private; 1398 struct pid_namespace *ns = proc_pid_ns(inode); 1399 struct task_struct *p; 1400 1401 p = get_proc_task(inode); 1402 if (!p) 1403 return -ESRCH; 1404 proc_sched_show_task(p, ns, m); 1405 1406 put_task_struct(p); 1407 1408 return 0; 1409 } 1410 1411 static ssize_t 1412 sched_write(struct file *file, const char __user *buf, 1413 size_t count, loff_t *offset) 1414 { 1415 struct inode *inode = file_inode(file); 1416 struct task_struct *p; 1417 1418 p = get_proc_task(inode); 1419 if (!p) 1420 return -ESRCH; 1421 proc_sched_set_task(p); 1422 1423 put_task_struct(p); 1424 1425 return count; 1426 } 1427 1428 static int sched_open(struct inode *inode, struct file *filp) 1429 { 1430 return single_open(filp, sched_show, inode); 1431 } 1432 1433 static const struct file_operations proc_pid_sched_operations = { 1434 .open = sched_open, 1435 .read = seq_read, 1436 .write = sched_write, 1437 .llseek = seq_lseek, 1438 .release = single_release, 1439 }; 1440 1441 #endif 1442 1443 #ifdef CONFIG_SCHED_AUTOGROUP 1444 /* 1445 * Print out autogroup related information: 1446 */ 1447 static int sched_autogroup_show(struct seq_file *m, void *v) 1448 { 1449 struct inode *inode = m->private; 1450 struct task_struct *p; 1451 1452 p = get_proc_task(inode); 1453 if (!p) 1454 return -ESRCH; 1455 proc_sched_autogroup_show_task(p, m); 1456 1457 put_task_struct(p); 1458 1459 return 0; 1460 } 1461 1462 static ssize_t 1463 sched_autogroup_write(struct file *file, const char __user *buf, 1464 size_t count, loff_t *offset) 1465 { 1466 struct inode *inode = file_inode(file); 1467 struct task_struct *p; 1468 char buffer[PROC_NUMBUF]; 1469 int nice; 1470 int err; 1471 1472 memset(buffer, 0, sizeof(buffer)); 1473 if (count > sizeof(buffer) - 1) 1474 count = sizeof(buffer) - 1; 1475 if (copy_from_user(buffer, buf, count)) 1476 return -EFAULT; 1477 1478 err = kstrtoint(strstrip(buffer), 0, &nice); 1479 if (err < 0) 1480 return err; 1481 1482 p = get_proc_task(inode); 1483 if (!p) 1484 return -ESRCH; 1485 1486 err = proc_sched_autogroup_set_nice(p, nice); 1487 if (err) 1488 count = err; 1489 1490 put_task_struct(p); 1491 1492 return count; 1493 } 1494 1495 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1496 { 1497 int ret; 1498 1499 ret = single_open(filp, sched_autogroup_show, NULL); 1500 if (!ret) { 1501 struct seq_file *m = filp->private_data; 1502 1503 m->private = inode; 1504 } 1505 return ret; 1506 } 1507 1508 static const struct file_operations proc_pid_sched_autogroup_operations = { 1509 .open = sched_autogroup_open, 1510 .read = seq_read, 1511 .write = sched_autogroup_write, 1512 .llseek = seq_lseek, 1513 .release = single_release, 1514 }; 1515 1516 #endif /* CONFIG_SCHED_AUTOGROUP */ 1517 1518 static ssize_t comm_write(struct file *file, const char __user *buf, 1519 size_t count, loff_t *offset) 1520 { 1521 struct inode *inode = file_inode(file); 1522 struct task_struct *p; 1523 char buffer[TASK_COMM_LEN]; 1524 const size_t maxlen = sizeof(buffer) - 1; 1525 1526 memset(buffer, 0, sizeof(buffer)); 1527 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count)) 1528 return -EFAULT; 1529 1530 p = get_proc_task(inode); 1531 if (!p) 1532 return -ESRCH; 1533 1534 if (same_thread_group(current, p)) 1535 set_task_comm(p, buffer); 1536 else 1537 count = -EINVAL; 1538 1539 put_task_struct(p); 1540 1541 return count; 1542 } 1543 1544 static int comm_show(struct seq_file *m, void *v) 1545 { 1546 struct inode *inode = m->private; 1547 struct task_struct *p; 1548 1549 p = get_proc_task(inode); 1550 if (!p) 1551 return -ESRCH; 1552 1553 proc_task_name(m, p, false); 1554 seq_putc(m, '\n'); 1555 1556 put_task_struct(p); 1557 1558 return 0; 1559 } 1560 1561 static int comm_open(struct inode *inode, struct file *filp) 1562 { 1563 return single_open(filp, comm_show, inode); 1564 } 1565 1566 static const struct file_operations proc_pid_set_comm_operations = { 1567 .open = comm_open, 1568 .read = seq_read, 1569 .write = comm_write, 1570 .llseek = seq_lseek, 1571 .release = single_release, 1572 }; 1573 1574 static int proc_exe_link(struct dentry *dentry, struct path *exe_path) 1575 { 1576 struct task_struct *task; 1577 struct file *exe_file; 1578 1579 task = get_proc_task(d_inode(dentry)); 1580 if (!task) 1581 return -ENOENT; 1582 exe_file = get_task_exe_file(task); 1583 put_task_struct(task); 1584 if (exe_file) { 1585 *exe_path = exe_file->f_path; 1586 path_get(&exe_file->f_path); 1587 fput(exe_file); 1588 return 0; 1589 } else 1590 return -ENOENT; 1591 } 1592 1593 static const char *proc_pid_get_link(struct dentry *dentry, 1594 struct inode *inode, 1595 struct delayed_call *done) 1596 { 1597 struct path path; 1598 int error = -EACCES; 1599 1600 if (!dentry) 1601 return ERR_PTR(-ECHILD); 1602 1603 /* Are we allowed to snoop on the tasks file descriptors? */ 1604 if (!proc_fd_access_allowed(inode)) 1605 goto out; 1606 1607 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1608 if (error) 1609 goto out; 1610 1611 nd_jump_link(&path); 1612 return NULL; 1613 out: 1614 return ERR_PTR(error); 1615 } 1616 1617 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1618 { 1619 char *tmp = (char *)__get_free_page(GFP_KERNEL); 1620 char *pathname; 1621 int len; 1622 1623 if (!tmp) 1624 return -ENOMEM; 1625 1626 pathname = d_path(path, tmp, PAGE_SIZE); 1627 len = PTR_ERR(pathname); 1628 if (IS_ERR(pathname)) 1629 goto out; 1630 len = tmp + PAGE_SIZE - 1 - pathname; 1631 1632 if (len > buflen) 1633 len = buflen; 1634 if (copy_to_user(buffer, pathname, len)) 1635 len = -EFAULT; 1636 out: 1637 free_page((unsigned long)tmp); 1638 return len; 1639 } 1640 1641 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1642 { 1643 int error = -EACCES; 1644 struct inode *inode = d_inode(dentry); 1645 struct path path; 1646 1647 /* Are we allowed to snoop on the tasks file descriptors? */ 1648 if (!proc_fd_access_allowed(inode)) 1649 goto out; 1650 1651 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1652 if (error) 1653 goto out; 1654 1655 error = do_proc_readlink(&path, buffer, buflen); 1656 path_put(&path); 1657 out: 1658 return error; 1659 } 1660 1661 const struct inode_operations proc_pid_link_inode_operations = { 1662 .readlink = proc_pid_readlink, 1663 .get_link = proc_pid_get_link, 1664 .setattr = proc_setattr, 1665 }; 1666 1667 1668 /* building an inode */ 1669 1670 void task_dump_owner(struct task_struct *task, umode_t mode, 1671 kuid_t *ruid, kgid_t *rgid) 1672 { 1673 /* Depending on the state of dumpable compute who should own a 1674 * proc file for a task. 1675 */ 1676 const struct cred *cred; 1677 kuid_t uid; 1678 kgid_t gid; 1679 1680 if (unlikely(task->flags & PF_KTHREAD)) { 1681 *ruid = GLOBAL_ROOT_UID; 1682 *rgid = GLOBAL_ROOT_GID; 1683 return; 1684 } 1685 1686 /* Default to the tasks effective ownership */ 1687 rcu_read_lock(); 1688 cred = __task_cred(task); 1689 uid = cred->euid; 1690 gid = cred->egid; 1691 rcu_read_unlock(); 1692 1693 /* 1694 * Before the /proc/pid/status file was created the only way to read 1695 * the effective uid of a /process was to stat /proc/pid. Reading 1696 * /proc/pid/status is slow enough that procps and other packages 1697 * kept stating /proc/pid. To keep the rules in /proc simple I have 1698 * made this apply to all per process world readable and executable 1699 * directories. 1700 */ 1701 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) { 1702 struct mm_struct *mm; 1703 task_lock(task); 1704 mm = task->mm; 1705 /* Make non-dumpable tasks owned by some root */ 1706 if (mm) { 1707 if (get_dumpable(mm) != SUID_DUMP_USER) { 1708 struct user_namespace *user_ns = mm->user_ns; 1709 1710 uid = make_kuid(user_ns, 0); 1711 if (!uid_valid(uid)) 1712 uid = GLOBAL_ROOT_UID; 1713 1714 gid = make_kgid(user_ns, 0); 1715 if (!gid_valid(gid)) 1716 gid = GLOBAL_ROOT_GID; 1717 } 1718 } else { 1719 uid = GLOBAL_ROOT_UID; 1720 gid = GLOBAL_ROOT_GID; 1721 } 1722 task_unlock(task); 1723 } 1724 *ruid = uid; 1725 *rgid = gid; 1726 } 1727 1728 struct inode *proc_pid_make_inode(struct super_block * sb, 1729 struct task_struct *task, umode_t mode) 1730 { 1731 struct inode * inode; 1732 struct proc_inode *ei; 1733 1734 /* We need a new inode */ 1735 1736 inode = new_inode(sb); 1737 if (!inode) 1738 goto out; 1739 1740 /* Common stuff */ 1741 ei = PROC_I(inode); 1742 inode->i_mode = mode; 1743 inode->i_ino = get_next_ino(); 1744 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 1745 inode->i_op = &proc_def_inode_operations; 1746 1747 /* 1748 * grab the reference to task. 1749 */ 1750 ei->pid = get_task_pid(task, PIDTYPE_PID); 1751 if (!ei->pid) 1752 goto out_unlock; 1753 1754 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); 1755 security_task_to_inode(task, inode); 1756 1757 out: 1758 return inode; 1759 1760 out_unlock: 1761 iput(inode); 1762 return NULL; 1763 } 1764 1765 int pid_getattr(const struct path *path, struct kstat *stat, 1766 u32 request_mask, unsigned int query_flags) 1767 { 1768 struct inode *inode = d_inode(path->dentry); 1769 struct pid_namespace *pid = proc_pid_ns(inode); 1770 struct task_struct *task; 1771 1772 generic_fillattr(inode, stat); 1773 1774 stat->uid = GLOBAL_ROOT_UID; 1775 stat->gid = GLOBAL_ROOT_GID; 1776 rcu_read_lock(); 1777 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1778 if (task) { 1779 if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) { 1780 rcu_read_unlock(); 1781 /* 1782 * This doesn't prevent learning whether PID exists, 1783 * it only makes getattr() consistent with readdir(). 1784 */ 1785 return -ENOENT; 1786 } 1787 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid); 1788 } 1789 rcu_read_unlock(); 1790 return 0; 1791 } 1792 1793 /* dentry stuff */ 1794 1795 /* 1796 * Set <pid>/... inode ownership (can change due to setuid(), etc.) 1797 */ 1798 void pid_update_inode(struct task_struct *task, struct inode *inode) 1799 { 1800 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid); 1801 1802 inode->i_mode &= ~(S_ISUID | S_ISGID); 1803 security_task_to_inode(task, inode); 1804 } 1805 1806 /* 1807 * Rewrite the inode's ownerships here because the owning task may have 1808 * performed a setuid(), etc. 1809 * 1810 */ 1811 static int pid_revalidate(struct dentry *dentry, unsigned int flags) 1812 { 1813 struct inode *inode; 1814 struct task_struct *task; 1815 1816 if (flags & LOOKUP_RCU) 1817 return -ECHILD; 1818 1819 inode = d_inode(dentry); 1820 task = get_proc_task(inode); 1821 1822 if (task) { 1823 pid_update_inode(task, inode); 1824 put_task_struct(task); 1825 return 1; 1826 } 1827 return 0; 1828 } 1829 1830 static inline bool proc_inode_is_dead(struct inode *inode) 1831 { 1832 return !proc_pid(inode)->tasks[PIDTYPE_PID].first; 1833 } 1834 1835 int pid_delete_dentry(const struct dentry *dentry) 1836 { 1837 /* Is the task we represent dead? 1838 * If so, then don't put the dentry on the lru list, 1839 * kill it immediately. 1840 */ 1841 return proc_inode_is_dead(d_inode(dentry)); 1842 } 1843 1844 const struct dentry_operations pid_dentry_operations = 1845 { 1846 .d_revalidate = pid_revalidate, 1847 .d_delete = pid_delete_dentry, 1848 }; 1849 1850 /* Lookups */ 1851 1852 /* 1853 * Fill a directory entry. 1854 * 1855 * If possible create the dcache entry and derive our inode number and 1856 * file type from dcache entry. 1857 * 1858 * Since all of the proc inode numbers are dynamically generated, the inode 1859 * numbers do not exist until the inode is cache. This means creating the 1860 * the dcache entry in readdir is necessary to keep the inode numbers 1861 * reported by readdir in sync with the inode numbers reported 1862 * by stat. 1863 */ 1864 bool proc_fill_cache(struct file *file, struct dir_context *ctx, 1865 const char *name, unsigned int len, 1866 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1867 { 1868 struct dentry *child, *dir = file->f_path.dentry; 1869 struct qstr qname = QSTR_INIT(name, len); 1870 struct inode *inode; 1871 unsigned type = DT_UNKNOWN; 1872 ino_t ino = 1; 1873 1874 child = d_hash_and_lookup(dir, &qname); 1875 if (!child) { 1876 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 1877 child = d_alloc_parallel(dir, &qname, &wq); 1878 if (IS_ERR(child)) 1879 goto end_instantiate; 1880 if (d_in_lookup(child)) { 1881 struct dentry *res; 1882 res = instantiate(child, task, ptr); 1883 d_lookup_done(child); 1884 if (unlikely(res)) { 1885 dput(child); 1886 child = res; 1887 if (IS_ERR(child)) 1888 goto end_instantiate; 1889 } 1890 } 1891 } 1892 inode = d_inode(child); 1893 ino = inode->i_ino; 1894 type = inode->i_mode >> 12; 1895 dput(child); 1896 end_instantiate: 1897 return dir_emit(ctx, name, len, ino, type); 1898 } 1899 1900 /* 1901 * dname_to_vma_addr - maps a dentry name into two unsigned longs 1902 * which represent vma start and end addresses. 1903 */ 1904 static int dname_to_vma_addr(struct dentry *dentry, 1905 unsigned long *start, unsigned long *end) 1906 { 1907 const char *str = dentry->d_name.name; 1908 unsigned long long sval, eval; 1909 unsigned int len; 1910 1911 if (str[0] == '0' && str[1] != '-') 1912 return -EINVAL; 1913 len = _parse_integer(str, 16, &sval); 1914 if (len & KSTRTOX_OVERFLOW) 1915 return -EINVAL; 1916 if (sval != (unsigned long)sval) 1917 return -EINVAL; 1918 str += len; 1919 1920 if (*str != '-') 1921 return -EINVAL; 1922 str++; 1923 1924 if (str[0] == '0' && str[1]) 1925 return -EINVAL; 1926 len = _parse_integer(str, 16, &eval); 1927 if (len & KSTRTOX_OVERFLOW) 1928 return -EINVAL; 1929 if (eval != (unsigned long)eval) 1930 return -EINVAL; 1931 str += len; 1932 1933 if (*str != '\0') 1934 return -EINVAL; 1935 1936 *start = sval; 1937 *end = eval; 1938 1939 return 0; 1940 } 1941 1942 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags) 1943 { 1944 unsigned long vm_start, vm_end; 1945 bool exact_vma_exists = false; 1946 struct mm_struct *mm = NULL; 1947 struct task_struct *task; 1948 struct inode *inode; 1949 int status = 0; 1950 1951 if (flags & LOOKUP_RCU) 1952 return -ECHILD; 1953 1954 inode = d_inode(dentry); 1955 task = get_proc_task(inode); 1956 if (!task) 1957 goto out_notask; 1958 1959 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); 1960 if (IS_ERR_OR_NULL(mm)) 1961 goto out; 1962 1963 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 1964 status = down_read_killable(&mm->mmap_sem); 1965 if (!status) { 1966 exact_vma_exists = !!find_exact_vma(mm, vm_start, 1967 vm_end); 1968 up_read(&mm->mmap_sem); 1969 } 1970 } 1971 1972 mmput(mm); 1973 1974 if (exact_vma_exists) { 1975 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); 1976 1977 security_task_to_inode(task, inode); 1978 status = 1; 1979 } 1980 1981 out: 1982 put_task_struct(task); 1983 1984 out_notask: 1985 return status; 1986 } 1987 1988 static const struct dentry_operations tid_map_files_dentry_operations = { 1989 .d_revalidate = map_files_d_revalidate, 1990 .d_delete = pid_delete_dentry, 1991 }; 1992 1993 static int map_files_get_link(struct dentry *dentry, struct path *path) 1994 { 1995 unsigned long vm_start, vm_end; 1996 struct vm_area_struct *vma; 1997 struct task_struct *task; 1998 struct mm_struct *mm; 1999 int rc; 2000 2001 rc = -ENOENT; 2002 task = get_proc_task(d_inode(dentry)); 2003 if (!task) 2004 goto out; 2005 2006 mm = get_task_mm(task); 2007 put_task_struct(task); 2008 if (!mm) 2009 goto out; 2010 2011 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 2012 if (rc) 2013 goto out_mmput; 2014 2015 rc = down_read_killable(&mm->mmap_sem); 2016 if (rc) 2017 goto out_mmput; 2018 2019 rc = -ENOENT; 2020 vma = find_exact_vma(mm, vm_start, vm_end); 2021 if (vma && vma->vm_file) { 2022 *path = vma->vm_file->f_path; 2023 path_get(path); 2024 rc = 0; 2025 } 2026 up_read(&mm->mmap_sem); 2027 2028 out_mmput: 2029 mmput(mm); 2030 out: 2031 return rc; 2032 } 2033 2034 struct map_files_info { 2035 unsigned long start; 2036 unsigned long end; 2037 fmode_t mode; 2038 }; 2039 2040 /* 2041 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the 2042 * symlinks may be used to bypass permissions on ancestor directories in the 2043 * path to the file in question. 2044 */ 2045 static const char * 2046 proc_map_files_get_link(struct dentry *dentry, 2047 struct inode *inode, 2048 struct delayed_call *done) 2049 { 2050 if (!capable(CAP_SYS_ADMIN)) 2051 return ERR_PTR(-EPERM); 2052 2053 return proc_pid_get_link(dentry, inode, done); 2054 } 2055 2056 /* 2057 * Identical to proc_pid_link_inode_operations except for get_link() 2058 */ 2059 static const struct inode_operations proc_map_files_link_inode_operations = { 2060 .readlink = proc_pid_readlink, 2061 .get_link = proc_map_files_get_link, 2062 .setattr = proc_setattr, 2063 }; 2064 2065 static struct dentry * 2066 proc_map_files_instantiate(struct dentry *dentry, 2067 struct task_struct *task, const void *ptr) 2068 { 2069 fmode_t mode = (fmode_t)(unsigned long)ptr; 2070 struct proc_inode *ei; 2071 struct inode *inode; 2072 2073 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK | 2074 ((mode & FMODE_READ ) ? S_IRUSR : 0) | 2075 ((mode & FMODE_WRITE) ? S_IWUSR : 0)); 2076 if (!inode) 2077 return ERR_PTR(-ENOENT); 2078 2079 ei = PROC_I(inode); 2080 ei->op.proc_get_link = map_files_get_link; 2081 2082 inode->i_op = &proc_map_files_link_inode_operations; 2083 inode->i_size = 64; 2084 2085 d_set_d_op(dentry, &tid_map_files_dentry_operations); 2086 return d_splice_alias(inode, dentry); 2087 } 2088 2089 static struct dentry *proc_map_files_lookup(struct inode *dir, 2090 struct dentry *dentry, unsigned int flags) 2091 { 2092 unsigned long vm_start, vm_end; 2093 struct vm_area_struct *vma; 2094 struct task_struct *task; 2095 struct dentry *result; 2096 struct mm_struct *mm; 2097 2098 result = ERR_PTR(-ENOENT); 2099 task = get_proc_task(dir); 2100 if (!task) 2101 goto out; 2102 2103 result = ERR_PTR(-EACCES); 2104 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2105 goto out_put_task; 2106 2107 result = ERR_PTR(-ENOENT); 2108 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 2109 goto out_put_task; 2110 2111 mm = get_task_mm(task); 2112 if (!mm) 2113 goto out_put_task; 2114 2115 result = ERR_PTR(-EINTR); 2116 if (down_read_killable(&mm->mmap_sem)) 2117 goto out_put_mm; 2118 2119 result = ERR_PTR(-ENOENT); 2120 vma = find_exact_vma(mm, vm_start, vm_end); 2121 if (!vma) 2122 goto out_no_vma; 2123 2124 if (vma->vm_file) 2125 result = proc_map_files_instantiate(dentry, task, 2126 (void *)(unsigned long)vma->vm_file->f_mode); 2127 2128 out_no_vma: 2129 up_read(&mm->mmap_sem); 2130 out_put_mm: 2131 mmput(mm); 2132 out_put_task: 2133 put_task_struct(task); 2134 out: 2135 return result; 2136 } 2137 2138 static const struct inode_operations proc_map_files_inode_operations = { 2139 .lookup = proc_map_files_lookup, 2140 .permission = proc_fd_permission, 2141 .setattr = proc_setattr, 2142 }; 2143 2144 static int 2145 proc_map_files_readdir(struct file *file, struct dir_context *ctx) 2146 { 2147 struct vm_area_struct *vma; 2148 struct task_struct *task; 2149 struct mm_struct *mm; 2150 unsigned long nr_files, pos, i; 2151 GENRADIX(struct map_files_info) fa; 2152 struct map_files_info *p; 2153 int ret; 2154 2155 genradix_init(&fa); 2156 2157 ret = -ENOENT; 2158 task = get_proc_task(file_inode(file)); 2159 if (!task) 2160 goto out; 2161 2162 ret = -EACCES; 2163 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2164 goto out_put_task; 2165 2166 ret = 0; 2167 if (!dir_emit_dots(file, ctx)) 2168 goto out_put_task; 2169 2170 mm = get_task_mm(task); 2171 if (!mm) 2172 goto out_put_task; 2173 2174 ret = down_read_killable(&mm->mmap_sem); 2175 if (ret) { 2176 mmput(mm); 2177 goto out_put_task; 2178 } 2179 2180 nr_files = 0; 2181 2182 /* 2183 * We need two passes here: 2184 * 2185 * 1) Collect vmas of mapped files with mmap_sem taken 2186 * 2) Release mmap_sem and instantiate entries 2187 * 2188 * otherwise we get lockdep complained, since filldir() 2189 * routine might require mmap_sem taken in might_fault(). 2190 */ 2191 2192 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 2193 if (!vma->vm_file) 2194 continue; 2195 if (++pos <= ctx->pos) 2196 continue; 2197 2198 p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL); 2199 if (!p) { 2200 ret = -ENOMEM; 2201 up_read(&mm->mmap_sem); 2202 mmput(mm); 2203 goto out_put_task; 2204 } 2205 2206 p->start = vma->vm_start; 2207 p->end = vma->vm_end; 2208 p->mode = vma->vm_file->f_mode; 2209 } 2210 up_read(&mm->mmap_sem); 2211 mmput(mm); 2212 2213 for (i = 0; i < nr_files; i++) { 2214 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */ 2215 unsigned int len; 2216 2217 p = genradix_ptr(&fa, i); 2218 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end); 2219 if (!proc_fill_cache(file, ctx, 2220 buf, len, 2221 proc_map_files_instantiate, 2222 task, 2223 (void *)(unsigned long)p->mode)) 2224 break; 2225 ctx->pos++; 2226 } 2227 2228 out_put_task: 2229 put_task_struct(task); 2230 out: 2231 genradix_free(&fa); 2232 return ret; 2233 } 2234 2235 static const struct file_operations proc_map_files_operations = { 2236 .read = generic_read_dir, 2237 .iterate_shared = proc_map_files_readdir, 2238 .llseek = generic_file_llseek, 2239 }; 2240 2241 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS) 2242 struct timers_private { 2243 struct pid *pid; 2244 struct task_struct *task; 2245 struct sighand_struct *sighand; 2246 struct pid_namespace *ns; 2247 unsigned long flags; 2248 }; 2249 2250 static void *timers_start(struct seq_file *m, loff_t *pos) 2251 { 2252 struct timers_private *tp = m->private; 2253 2254 tp->task = get_pid_task(tp->pid, PIDTYPE_PID); 2255 if (!tp->task) 2256 return ERR_PTR(-ESRCH); 2257 2258 tp->sighand = lock_task_sighand(tp->task, &tp->flags); 2259 if (!tp->sighand) 2260 return ERR_PTR(-ESRCH); 2261 2262 return seq_list_start(&tp->task->signal->posix_timers, *pos); 2263 } 2264 2265 static void *timers_next(struct seq_file *m, void *v, loff_t *pos) 2266 { 2267 struct timers_private *tp = m->private; 2268 return seq_list_next(v, &tp->task->signal->posix_timers, pos); 2269 } 2270 2271 static void timers_stop(struct seq_file *m, void *v) 2272 { 2273 struct timers_private *tp = m->private; 2274 2275 if (tp->sighand) { 2276 unlock_task_sighand(tp->task, &tp->flags); 2277 tp->sighand = NULL; 2278 } 2279 2280 if (tp->task) { 2281 put_task_struct(tp->task); 2282 tp->task = NULL; 2283 } 2284 } 2285 2286 static int show_timer(struct seq_file *m, void *v) 2287 { 2288 struct k_itimer *timer; 2289 struct timers_private *tp = m->private; 2290 int notify; 2291 static const char * const nstr[] = { 2292 [SIGEV_SIGNAL] = "signal", 2293 [SIGEV_NONE] = "none", 2294 [SIGEV_THREAD] = "thread", 2295 }; 2296 2297 timer = list_entry((struct list_head *)v, struct k_itimer, list); 2298 notify = timer->it_sigev_notify; 2299 2300 seq_printf(m, "ID: %d\n", timer->it_id); 2301 seq_printf(m, "signal: %d/%px\n", 2302 timer->sigq->info.si_signo, 2303 timer->sigq->info.si_value.sival_ptr); 2304 seq_printf(m, "notify: %s/%s.%d\n", 2305 nstr[notify & ~SIGEV_THREAD_ID], 2306 (notify & SIGEV_THREAD_ID) ? "tid" : "pid", 2307 pid_nr_ns(timer->it_pid, tp->ns)); 2308 seq_printf(m, "ClockID: %d\n", timer->it_clock); 2309 2310 return 0; 2311 } 2312 2313 static const struct seq_operations proc_timers_seq_ops = { 2314 .start = timers_start, 2315 .next = timers_next, 2316 .stop = timers_stop, 2317 .show = show_timer, 2318 }; 2319 2320 static int proc_timers_open(struct inode *inode, struct file *file) 2321 { 2322 struct timers_private *tp; 2323 2324 tp = __seq_open_private(file, &proc_timers_seq_ops, 2325 sizeof(struct timers_private)); 2326 if (!tp) 2327 return -ENOMEM; 2328 2329 tp->pid = proc_pid(inode); 2330 tp->ns = proc_pid_ns(inode); 2331 return 0; 2332 } 2333 2334 static const struct file_operations proc_timers_operations = { 2335 .open = proc_timers_open, 2336 .read = seq_read, 2337 .llseek = seq_lseek, 2338 .release = seq_release_private, 2339 }; 2340 #endif 2341 2342 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf, 2343 size_t count, loff_t *offset) 2344 { 2345 struct inode *inode = file_inode(file); 2346 struct task_struct *p; 2347 u64 slack_ns; 2348 int err; 2349 2350 err = kstrtoull_from_user(buf, count, 10, &slack_ns); 2351 if (err < 0) 2352 return err; 2353 2354 p = get_proc_task(inode); 2355 if (!p) 2356 return -ESRCH; 2357 2358 if (p != current) { 2359 rcu_read_lock(); 2360 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { 2361 rcu_read_unlock(); 2362 count = -EPERM; 2363 goto out; 2364 } 2365 rcu_read_unlock(); 2366 2367 err = security_task_setscheduler(p); 2368 if (err) { 2369 count = err; 2370 goto out; 2371 } 2372 } 2373 2374 task_lock(p); 2375 if (slack_ns == 0) 2376 p->timer_slack_ns = p->default_timer_slack_ns; 2377 else 2378 p->timer_slack_ns = slack_ns; 2379 task_unlock(p); 2380 2381 out: 2382 put_task_struct(p); 2383 2384 return count; 2385 } 2386 2387 static int timerslack_ns_show(struct seq_file *m, void *v) 2388 { 2389 struct inode *inode = m->private; 2390 struct task_struct *p; 2391 int err = 0; 2392 2393 p = get_proc_task(inode); 2394 if (!p) 2395 return -ESRCH; 2396 2397 if (p != current) { 2398 rcu_read_lock(); 2399 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { 2400 rcu_read_unlock(); 2401 err = -EPERM; 2402 goto out; 2403 } 2404 rcu_read_unlock(); 2405 2406 err = security_task_getscheduler(p); 2407 if (err) 2408 goto out; 2409 } 2410 2411 task_lock(p); 2412 seq_printf(m, "%llu\n", p->timer_slack_ns); 2413 task_unlock(p); 2414 2415 out: 2416 put_task_struct(p); 2417 2418 return err; 2419 } 2420 2421 static int timerslack_ns_open(struct inode *inode, struct file *filp) 2422 { 2423 return single_open(filp, timerslack_ns_show, inode); 2424 } 2425 2426 static const struct file_operations proc_pid_set_timerslack_ns_operations = { 2427 .open = timerslack_ns_open, 2428 .read = seq_read, 2429 .write = timerslack_ns_write, 2430 .llseek = seq_lseek, 2431 .release = single_release, 2432 }; 2433 2434 static struct dentry *proc_pident_instantiate(struct dentry *dentry, 2435 struct task_struct *task, const void *ptr) 2436 { 2437 const struct pid_entry *p = ptr; 2438 struct inode *inode; 2439 struct proc_inode *ei; 2440 2441 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode); 2442 if (!inode) 2443 return ERR_PTR(-ENOENT); 2444 2445 ei = PROC_I(inode); 2446 if (S_ISDIR(inode->i_mode)) 2447 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2448 if (p->iop) 2449 inode->i_op = p->iop; 2450 if (p->fop) 2451 inode->i_fop = p->fop; 2452 ei->op = p->op; 2453 pid_update_inode(task, inode); 2454 d_set_d_op(dentry, &pid_dentry_operations); 2455 return d_splice_alias(inode, dentry); 2456 } 2457 2458 static struct dentry *proc_pident_lookup(struct inode *dir, 2459 struct dentry *dentry, 2460 const struct pid_entry *p, 2461 const struct pid_entry *end) 2462 { 2463 struct task_struct *task = get_proc_task(dir); 2464 struct dentry *res = ERR_PTR(-ENOENT); 2465 2466 if (!task) 2467 goto out_no_task; 2468 2469 /* 2470 * Yes, it does not scale. And it should not. Don't add 2471 * new entries into /proc/<tgid>/ without very good reasons. 2472 */ 2473 for (; p < end; p++) { 2474 if (p->len != dentry->d_name.len) 2475 continue; 2476 if (!memcmp(dentry->d_name.name, p->name, p->len)) { 2477 res = proc_pident_instantiate(dentry, task, p); 2478 break; 2479 } 2480 } 2481 put_task_struct(task); 2482 out_no_task: 2483 return res; 2484 } 2485 2486 static int proc_pident_readdir(struct file *file, struct dir_context *ctx, 2487 const struct pid_entry *ents, unsigned int nents) 2488 { 2489 struct task_struct *task = get_proc_task(file_inode(file)); 2490 const struct pid_entry *p; 2491 2492 if (!task) 2493 return -ENOENT; 2494 2495 if (!dir_emit_dots(file, ctx)) 2496 goto out; 2497 2498 if (ctx->pos >= nents + 2) 2499 goto out; 2500 2501 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) { 2502 if (!proc_fill_cache(file, ctx, p->name, p->len, 2503 proc_pident_instantiate, task, p)) 2504 break; 2505 ctx->pos++; 2506 } 2507 out: 2508 put_task_struct(task); 2509 return 0; 2510 } 2511 2512 #ifdef CONFIG_SECURITY 2513 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2514 size_t count, loff_t *ppos) 2515 { 2516 struct inode * inode = file_inode(file); 2517 char *p = NULL; 2518 ssize_t length; 2519 struct task_struct *task = get_proc_task(inode); 2520 2521 if (!task) 2522 return -ESRCH; 2523 2524 length = security_getprocattr(task, PROC_I(inode)->op.lsm, 2525 (char*)file->f_path.dentry->d_name.name, 2526 &p); 2527 put_task_struct(task); 2528 if (length > 0) 2529 length = simple_read_from_buffer(buf, count, ppos, p, length); 2530 kfree(p); 2531 return length; 2532 } 2533 2534 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2535 size_t count, loff_t *ppos) 2536 { 2537 struct inode * inode = file_inode(file); 2538 struct task_struct *task; 2539 void *page; 2540 int rv; 2541 2542 rcu_read_lock(); 2543 task = pid_task(proc_pid(inode), PIDTYPE_PID); 2544 if (!task) { 2545 rcu_read_unlock(); 2546 return -ESRCH; 2547 } 2548 /* A task may only write its own attributes. */ 2549 if (current != task) { 2550 rcu_read_unlock(); 2551 return -EACCES; 2552 } 2553 /* Prevent changes to overridden credentials. */ 2554 if (current_cred() != current_real_cred()) { 2555 rcu_read_unlock(); 2556 return -EBUSY; 2557 } 2558 rcu_read_unlock(); 2559 2560 if (count > PAGE_SIZE) 2561 count = PAGE_SIZE; 2562 2563 /* No partial writes. */ 2564 if (*ppos != 0) 2565 return -EINVAL; 2566 2567 page = memdup_user(buf, count); 2568 if (IS_ERR(page)) { 2569 rv = PTR_ERR(page); 2570 goto out; 2571 } 2572 2573 /* Guard against adverse ptrace interaction */ 2574 rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex); 2575 if (rv < 0) 2576 goto out_free; 2577 2578 rv = security_setprocattr(PROC_I(inode)->op.lsm, 2579 file->f_path.dentry->d_name.name, page, 2580 count); 2581 mutex_unlock(¤t->signal->cred_guard_mutex); 2582 out_free: 2583 kfree(page); 2584 out: 2585 return rv; 2586 } 2587 2588 static const struct file_operations proc_pid_attr_operations = { 2589 .read = proc_pid_attr_read, 2590 .write = proc_pid_attr_write, 2591 .llseek = generic_file_llseek, 2592 }; 2593 2594 #define LSM_DIR_OPS(LSM) \ 2595 static int proc_##LSM##_attr_dir_iterate(struct file *filp, \ 2596 struct dir_context *ctx) \ 2597 { \ 2598 return proc_pident_readdir(filp, ctx, \ 2599 LSM##_attr_dir_stuff, \ 2600 ARRAY_SIZE(LSM##_attr_dir_stuff)); \ 2601 } \ 2602 \ 2603 static const struct file_operations proc_##LSM##_attr_dir_ops = { \ 2604 .read = generic_read_dir, \ 2605 .iterate = proc_##LSM##_attr_dir_iterate, \ 2606 .llseek = default_llseek, \ 2607 }; \ 2608 \ 2609 static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \ 2610 struct dentry *dentry, unsigned int flags) \ 2611 { \ 2612 return proc_pident_lookup(dir, dentry, \ 2613 LSM##_attr_dir_stuff, \ 2614 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \ 2615 } \ 2616 \ 2617 static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \ 2618 .lookup = proc_##LSM##_attr_dir_lookup, \ 2619 .getattr = pid_getattr, \ 2620 .setattr = proc_setattr, \ 2621 } 2622 2623 #ifdef CONFIG_SECURITY_SMACK 2624 static const struct pid_entry smack_attr_dir_stuff[] = { 2625 ATTR("smack", "current", 0666), 2626 }; 2627 LSM_DIR_OPS(smack); 2628 #endif 2629 2630 static const struct pid_entry attr_dir_stuff[] = { 2631 ATTR(NULL, "current", 0666), 2632 ATTR(NULL, "prev", 0444), 2633 ATTR(NULL, "exec", 0666), 2634 ATTR(NULL, "fscreate", 0666), 2635 ATTR(NULL, "keycreate", 0666), 2636 ATTR(NULL, "sockcreate", 0666), 2637 #ifdef CONFIG_SECURITY_SMACK 2638 DIR("smack", 0555, 2639 proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops), 2640 #endif 2641 }; 2642 2643 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx) 2644 { 2645 return proc_pident_readdir(file, ctx, 2646 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2647 } 2648 2649 static const struct file_operations proc_attr_dir_operations = { 2650 .read = generic_read_dir, 2651 .iterate_shared = proc_attr_dir_readdir, 2652 .llseek = generic_file_llseek, 2653 }; 2654 2655 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2656 struct dentry *dentry, unsigned int flags) 2657 { 2658 return proc_pident_lookup(dir, dentry, 2659 attr_dir_stuff, 2660 attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff)); 2661 } 2662 2663 static const struct inode_operations proc_attr_dir_inode_operations = { 2664 .lookup = proc_attr_dir_lookup, 2665 .getattr = pid_getattr, 2666 .setattr = proc_setattr, 2667 }; 2668 2669 #endif 2670 2671 #ifdef CONFIG_ELF_CORE 2672 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2673 size_t count, loff_t *ppos) 2674 { 2675 struct task_struct *task = get_proc_task(file_inode(file)); 2676 struct mm_struct *mm; 2677 char buffer[PROC_NUMBUF]; 2678 size_t len; 2679 int ret; 2680 2681 if (!task) 2682 return -ESRCH; 2683 2684 ret = 0; 2685 mm = get_task_mm(task); 2686 if (mm) { 2687 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2688 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2689 MMF_DUMP_FILTER_SHIFT)); 2690 mmput(mm); 2691 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2692 } 2693 2694 put_task_struct(task); 2695 2696 return ret; 2697 } 2698 2699 static ssize_t proc_coredump_filter_write(struct file *file, 2700 const char __user *buf, 2701 size_t count, 2702 loff_t *ppos) 2703 { 2704 struct task_struct *task; 2705 struct mm_struct *mm; 2706 unsigned int val; 2707 int ret; 2708 int i; 2709 unsigned long mask; 2710 2711 ret = kstrtouint_from_user(buf, count, 0, &val); 2712 if (ret < 0) 2713 return ret; 2714 2715 ret = -ESRCH; 2716 task = get_proc_task(file_inode(file)); 2717 if (!task) 2718 goto out_no_task; 2719 2720 mm = get_task_mm(task); 2721 if (!mm) 2722 goto out_no_mm; 2723 ret = 0; 2724 2725 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2726 if (val & mask) 2727 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2728 else 2729 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2730 } 2731 2732 mmput(mm); 2733 out_no_mm: 2734 put_task_struct(task); 2735 out_no_task: 2736 if (ret < 0) 2737 return ret; 2738 return count; 2739 } 2740 2741 static const struct file_operations proc_coredump_filter_operations = { 2742 .read = proc_coredump_filter_read, 2743 .write = proc_coredump_filter_write, 2744 .llseek = generic_file_llseek, 2745 }; 2746 #endif 2747 2748 #ifdef CONFIG_TASK_IO_ACCOUNTING 2749 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole) 2750 { 2751 struct task_io_accounting acct = task->ioac; 2752 unsigned long flags; 2753 int result; 2754 2755 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2756 if (result) 2757 return result; 2758 2759 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { 2760 result = -EACCES; 2761 goto out_unlock; 2762 } 2763 2764 if (whole && lock_task_sighand(task, &flags)) { 2765 struct task_struct *t = task; 2766 2767 task_io_accounting_add(&acct, &task->signal->ioac); 2768 while_each_thread(task, t) 2769 task_io_accounting_add(&acct, &t->ioac); 2770 2771 unlock_task_sighand(task, &flags); 2772 } 2773 seq_printf(m, 2774 "rchar: %llu\n" 2775 "wchar: %llu\n" 2776 "syscr: %llu\n" 2777 "syscw: %llu\n" 2778 "read_bytes: %llu\n" 2779 "write_bytes: %llu\n" 2780 "cancelled_write_bytes: %llu\n", 2781 (unsigned long long)acct.rchar, 2782 (unsigned long long)acct.wchar, 2783 (unsigned long long)acct.syscr, 2784 (unsigned long long)acct.syscw, 2785 (unsigned long long)acct.read_bytes, 2786 (unsigned long long)acct.write_bytes, 2787 (unsigned long long)acct.cancelled_write_bytes); 2788 result = 0; 2789 2790 out_unlock: 2791 mutex_unlock(&task->signal->cred_guard_mutex); 2792 return result; 2793 } 2794 2795 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2796 struct pid *pid, struct task_struct *task) 2797 { 2798 return do_io_accounting(task, m, 0); 2799 } 2800 2801 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2802 struct pid *pid, struct task_struct *task) 2803 { 2804 return do_io_accounting(task, m, 1); 2805 } 2806 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2807 2808 #ifdef CONFIG_USER_NS 2809 static int proc_id_map_open(struct inode *inode, struct file *file, 2810 const struct seq_operations *seq_ops) 2811 { 2812 struct user_namespace *ns = NULL; 2813 struct task_struct *task; 2814 struct seq_file *seq; 2815 int ret = -EINVAL; 2816 2817 task = get_proc_task(inode); 2818 if (task) { 2819 rcu_read_lock(); 2820 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2821 rcu_read_unlock(); 2822 put_task_struct(task); 2823 } 2824 if (!ns) 2825 goto err; 2826 2827 ret = seq_open(file, seq_ops); 2828 if (ret) 2829 goto err_put_ns; 2830 2831 seq = file->private_data; 2832 seq->private = ns; 2833 2834 return 0; 2835 err_put_ns: 2836 put_user_ns(ns); 2837 err: 2838 return ret; 2839 } 2840 2841 static int proc_id_map_release(struct inode *inode, struct file *file) 2842 { 2843 struct seq_file *seq = file->private_data; 2844 struct user_namespace *ns = seq->private; 2845 put_user_ns(ns); 2846 return seq_release(inode, file); 2847 } 2848 2849 static int proc_uid_map_open(struct inode *inode, struct file *file) 2850 { 2851 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2852 } 2853 2854 static int proc_gid_map_open(struct inode *inode, struct file *file) 2855 { 2856 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2857 } 2858 2859 static int proc_projid_map_open(struct inode *inode, struct file *file) 2860 { 2861 return proc_id_map_open(inode, file, &proc_projid_seq_operations); 2862 } 2863 2864 static const struct file_operations proc_uid_map_operations = { 2865 .open = proc_uid_map_open, 2866 .write = proc_uid_map_write, 2867 .read = seq_read, 2868 .llseek = seq_lseek, 2869 .release = proc_id_map_release, 2870 }; 2871 2872 static const struct file_operations proc_gid_map_operations = { 2873 .open = proc_gid_map_open, 2874 .write = proc_gid_map_write, 2875 .read = seq_read, 2876 .llseek = seq_lseek, 2877 .release = proc_id_map_release, 2878 }; 2879 2880 static const struct file_operations proc_projid_map_operations = { 2881 .open = proc_projid_map_open, 2882 .write = proc_projid_map_write, 2883 .read = seq_read, 2884 .llseek = seq_lseek, 2885 .release = proc_id_map_release, 2886 }; 2887 2888 static int proc_setgroups_open(struct inode *inode, struct file *file) 2889 { 2890 struct user_namespace *ns = NULL; 2891 struct task_struct *task; 2892 int ret; 2893 2894 ret = -ESRCH; 2895 task = get_proc_task(inode); 2896 if (task) { 2897 rcu_read_lock(); 2898 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2899 rcu_read_unlock(); 2900 put_task_struct(task); 2901 } 2902 if (!ns) 2903 goto err; 2904 2905 if (file->f_mode & FMODE_WRITE) { 2906 ret = -EACCES; 2907 if (!ns_capable(ns, CAP_SYS_ADMIN)) 2908 goto err_put_ns; 2909 } 2910 2911 ret = single_open(file, &proc_setgroups_show, ns); 2912 if (ret) 2913 goto err_put_ns; 2914 2915 return 0; 2916 err_put_ns: 2917 put_user_ns(ns); 2918 err: 2919 return ret; 2920 } 2921 2922 static int proc_setgroups_release(struct inode *inode, struct file *file) 2923 { 2924 struct seq_file *seq = file->private_data; 2925 struct user_namespace *ns = seq->private; 2926 int ret = single_release(inode, file); 2927 put_user_ns(ns); 2928 return ret; 2929 } 2930 2931 static const struct file_operations proc_setgroups_operations = { 2932 .open = proc_setgroups_open, 2933 .write = proc_setgroups_write, 2934 .read = seq_read, 2935 .llseek = seq_lseek, 2936 .release = proc_setgroups_release, 2937 }; 2938 #endif /* CONFIG_USER_NS */ 2939 2940 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2941 struct pid *pid, struct task_struct *task) 2942 { 2943 int err = lock_trace(task); 2944 if (!err) { 2945 seq_printf(m, "%08x\n", task->personality); 2946 unlock_trace(task); 2947 } 2948 return err; 2949 } 2950 2951 #ifdef CONFIG_LIVEPATCH 2952 static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns, 2953 struct pid *pid, struct task_struct *task) 2954 { 2955 seq_printf(m, "%d\n", task->patch_state); 2956 return 0; 2957 } 2958 #endif /* CONFIG_LIVEPATCH */ 2959 2960 #ifdef CONFIG_STACKLEAK_METRICS 2961 static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns, 2962 struct pid *pid, struct task_struct *task) 2963 { 2964 unsigned long prev_depth = THREAD_SIZE - 2965 (task->prev_lowest_stack & (THREAD_SIZE - 1)); 2966 unsigned long depth = THREAD_SIZE - 2967 (task->lowest_stack & (THREAD_SIZE - 1)); 2968 2969 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n", 2970 prev_depth, depth); 2971 return 0; 2972 } 2973 #endif /* CONFIG_STACKLEAK_METRICS */ 2974 2975 /* 2976 * Thread groups 2977 */ 2978 static const struct file_operations proc_task_operations; 2979 static const struct inode_operations proc_task_inode_operations; 2980 2981 static const struct pid_entry tgid_base_stuff[] = { 2982 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2983 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2984 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 2985 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2986 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2987 #ifdef CONFIG_NET 2988 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2989 #endif 2990 REG("environ", S_IRUSR, proc_environ_operations), 2991 REG("auxv", S_IRUSR, proc_auxv_operations), 2992 ONE("status", S_IRUGO, proc_pid_status), 2993 ONE("personality", S_IRUSR, proc_pid_personality), 2994 ONE("limits", S_IRUGO, proc_pid_limits), 2995 #ifdef CONFIG_SCHED_DEBUG 2996 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2997 #endif 2998 #ifdef CONFIG_SCHED_AUTOGROUP 2999 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 3000 #endif 3001 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3002 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3003 ONE("syscall", S_IRUSR, proc_pid_syscall), 3004 #endif 3005 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 3006 ONE("stat", S_IRUGO, proc_tgid_stat), 3007 ONE("statm", S_IRUGO, proc_pid_statm), 3008 REG("maps", S_IRUGO, proc_pid_maps_operations), 3009 #ifdef CONFIG_NUMA 3010 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 3011 #endif 3012 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3013 LNK("cwd", proc_cwd_link), 3014 LNK("root", proc_root_link), 3015 LNK("exe", proc_exe_link), 3016 REG("mounts", S_IRUGO, proc_mounts_operations), 3017 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3018 REG("mountstats", S_IRUSR, proc_mountstats_operations), 3019 #ifdef CONFIG_PROC_PAGE_MONITOR 3020 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3021 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 3022 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations), 3023 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3024 #endif 3025 #ifdef CONFIG_SECURITY 3026 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3027 #endif 3028 #ifdef CONFIG_KALLSYMS 3029 ONE("wchan", S_IRUGO, proc_pid_wchan), 3030 #endif 3031 #ifdef CONFIG_STACKTRACE 3032 ONE("stack", S_IRUSR, proc_pid_stack), 3033 #endif 3034 #ifdef CONFIG_SCHED_INFO 3035 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 3036 #endif 3037 #ifdef CONFIG_LATENCYTOP 3038 REG("latency", S_IRUGO, proc_lstats_operations), 3039 #endif 3040 #ifdef CONFIG_PROC_PID_CPUSET 3041 ONE("cpuset", S_IRUGO, proc_cpuset_show), 3042 #endif 3043 #ifdef CONFIG_CGROUPS 3044 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3045 #endif 3046 ONE("oom_score", S_IRUGO, proc_oom_score), 3047 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3048 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3049 #ifdef CONFIG_AUDIT 3050 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3051 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3052 #endif 3053 #ifdef CONFIG_FAULT_INJECTION 3054 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3055 REG("fail-nth", 0644, proc_fail_nth_operations), 3056 #endif 3057 #ifdef CONFIG_ELF_CORE 3058 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 3059 #endif 3060 #ifdef CONFIG_TASK_IO_ACCOUNTING 3061 ONE("io", S_IRUSR, proc_tgid_io_accounting), 3062 #endif 3063 #ifdef CONFIG_USER_NS 3064 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3065 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3066 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3067 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3068 #endif 3069 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS) 3070 REG("timers", S_IRUGO, proc_timers_operations), 3071 #endif 3072 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations), 3073 #ifdef CONFIG_LIVEPATCH 3074 ONE("patch_state", S_IRUSR, proc_pid_patch_state), 3075 #endif 3076 #ifdef CONFIG_STACKLEAK_METRICS 3077 ONE("stack_depth", S_IRUGO, proc_stack_depth), 3078 #endif 3079 #ifdef CONFIG_PROC_PID_ARCH_STATUS 3080 ONE("arch_status", S_IRUGO, proc_pid_arch_status), 3081 #endif 3082 }; 3083 3084 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) 3085 { 3086 return proc_pident_readdir(file, ctx, 3087 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3088 } 3089 3090 static const struct file_operations proc_tgid_base_operations = { 3091 .read = generic_read_dir, 3092 .iterate_shared = proc_tgid_base_readdir, 3093 .llseek = generic_file_llseek, 3094 }; 3095 3096 struct pid *tgid_pidfd_to_pid(const struct file *file) 3097 { 3098 if (file->f_op != &proc_tgid_base_operations) 3099 return ERR_PTR(-EBADF); 3100 3101 return proc_pid(file_inode(file)); 3102 } 3103 3104 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3105 { 3106 return proc_pident_lookup(dir, dentry, 3107 tgid_base_stuff, 3108 tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff)); 3109 } 3110 3111 static const struct inode_operations proc_tgid_base_inode_operations = { 3112 .lookup = proc_tgid_base_lookup, 3113 .getattr = pid_getattr, 3114 .setattr = proc_setattr, 3115 .permission = proc_pid_permission, 3116 }; 3117 3118 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 3119 { 3120 struct dentry *dentry, *leader, *dir; 3121 char buf[10 + 1]; 3122 struct qstr name; 3123 3124 name.name = buf; 3125 name.len = snprintf(buf, sizeof(buf), "%u", pid); 3126 /* no ->d_hash() rejects on procfs */ 3127 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 3128 if (dentry) { 3129 d_invalidate(dentry); 3130 dput(dentry); 3131 } 3132 3133 if (pid == tgid) 3134 return; 3135 3136 name.name = buf; 3137 name.len = snprintf(buf, sizeof(buf), "%u", tgid); 3138 leader = d_hash_and_lookup(mnt->mnt_root, &name); 3139 if (!leader) 3140 goto out; 3141 3142 name.name = "task"; 3143 name.len = strlen(name.name); 3144 dir = d_hash_and_lookup(leader, &name); 3145 if (!dir) 3146 goto out_put_leader; 3147 3148 name.name = buf; 3149 name.len = snprintf(buf, sizeof(buf), "%u", pid); 3150 dentry = d_hash_and_lookup(dir, &name); 3151 if (dentry) { 3152 d_invalidate(dentry); 3153 dput(dentry); 3154 } 3155 3156 dput(dir); 3157 out_put_leader: 3158 dput(leader); 3159 out: 3160 return; 3161 } 3162 3163 /** 3164 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 3165 * @task: task that should be flushed. 3166 * 3167 * When flushing dentries from proc, one needs to flush them from global 3168 * proc (proc_mnt) and from all the namespaces' procs this task was seen 3169 * in. This call is supposed to do all of this job. 3170 * 3171 * Looks in the dcache for 3172 * /proc/@pid 3173 * /proc/@tgid/task/@pid 3174 * if either directory is present flushes it and all of it'ts children 3175 * from the dcache. 3176 * 3177 * It is safe and reasonable to cache /proc entries for a task until 3178 * that task exits. After that they just clog up the dcache with 3179 * useless entries, possibly causing useful dcache entries to be 3180 * flushed instead. This routine is proved to flush those useless 3181 * dcache entries at process exit time. 3182 * 3183 * NOTE: This routine is just an optimization so it does not guarantee 3184 * that no dcache entries will exist at process exit time it 3185 * just makes it very unlikely that any will persist. 3186 */ 3187 3188 void proc_flush_task(struct task_struct *task) 3189 { 3190 int i; 3191 struct pid *pid, *tgid; 3192 struct upid *upid; 3193 3194 pid = task_pid(task); 3195 tgid = task_tgid(task); 3196 3197 for (i = 0; i <= pid->level; i++) { 3198 upid = &pid->numbers[i]; 3199 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3200 tgid->numbers[i].nr); 3201 } 3202 } 3203 3204 static struct dentry *proc_pid_instantiate(struct dentry * dentry, 3205 struct task_struct *task, const void *ptr) 3206 { 3207 struct inode *inode; 3208 3209 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3210 if (!inode) 3211 return ERR_PTR(-ENOENT); 3212 3213 inode->i_op = &proc_tgid_base_inode_operations; 3214 inode->i_fop = &proc_tgid_base_operations; 3215 inode->i_flags|=S_IMMUTABLE; 3216 3217 set_nlink(inode, nlink_tgid); 3218 pid_update_inode(task, inode); 3219 3220 d_set_d_op(dentry, &pid_dentry_operations); 3221 return d_splice_alias(inode, dentry); 3222 } 3223 3224 struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags) 3225 { 3226 struct task_struct *task; 3227 unsigned tgid; 3228 struct pid_namespace *ns; 3229 struct dentry *result = ERR_PTR(-ENOENT); 3230 3231 tgid = name_to_int(&dentry->d_name); 3232 if (tgid == ~0U) 3233 goto out; 3234 3235 ns = dentry->d_sb->s_fs_info; 3236 rcu_read_lock(); 3237 task = find_task_by_pid_ns(tgid, ns); 3238 if (task) 3239 get_task_struct(task); 3240 rcu_read_unlock(); 3241 if (!task) 3242 goto out; 3243 3244 result = proc_pid_instantiate(dentry, task, NULL); 3245 put_task_struct(task); 3246 out: 3247 return result; 3248 } 3249 3250 /* 3251 * Find the first task with tgid >= tgid 3252 * 3253 */ 3254 struct tgid_iter { 3255 unsigned int tgid; 3256 struct task_struct *task; 3257 }; 3258 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3259 { 3260 struct pid *pid; 3261 3262 if (iter.task) 3263 put_task_struct(iter.task); 3264 rcu_read_lock(); 3265 retry: 3266 iter.task = NULL; 3267 pid = find_ge_pid(iter.tgid, ns); 3268 if (pid) { 3269 iter.tgid = pid_nr_ns(pid, ns); 3270 iter.task = pid_task(pid, PIDTYPE_PID); 3271 /* What we to know is if the pid we have find is the 3272 * pid of a thread_group_leader. Testing for task 3273 * being a thread_group_leader is the obvious thing 3274 * todo but there is a window when it fails, due to 3275 * the pid transfer logic in de_thread. 3276 * 3277 * So we perform the straight forward test of seeing 3278 * if the pid we have found is the pid of a thread 3279 * group leader, and don't worry if the task we have 3280 * found doesn't happen to be a thread group leader. 3281 * As we don't care in the case of readdir. 3282 */ 3283 if (!iter.task || !has_group_leader_pid(iter.task)) { 3284 iter.tgid += 1; 3285 goto retry; 3286 } 3287 get_task_struct(iter.task); 3288 } 3289 rcu_read_unlock(); 3290 return iter; 3291 } 3292 3293 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2) 3294 3295 /* for the /proc/ directory itself, after non-process stuff has been done */ 3296 int proc_pid_readdir(struct file *file, struct dir_context *ctx) 3297 { 3298 struct tgid_iter iter; 3299 struct pid_namespace *ns = proc_pid_ns(file_inode(file)); 3300 loff_t pos = ctx->pos; 3301 3302 if (pos >= PID_MAX_LIMIT + TGID_OFFSET) 3303 return 0; 3304 3305 if (pos == TGID_OFFSET - 2) { 3306 struct inode *inode = d_inode(ns->proc_self); 3307 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) 3308 return 0; 3309 ctx->pos = pos = pos + 1; 3310 } 3311 if (pos == TGID_OFFSET - 1) { 3312 struct inode *inode = d_inode(ns->proc_thread_self); 3313 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) 3314 return 0; 3315 ctx->pos = pos = pos + 1; 3316 } 3317 iter.tgid = pos - TGID_OFFSET; 3318 iter.task = NULL; 3319 for (iter = next_tgid(ns, iter); 3320 iter.task; 3321 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3322 char name[10 + 1]; 3323 unsigned int len; 3324 3325 cond_resched(); 3326 if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE)) 3327 continue; 3328 3329 len = snprintf(name, sizeof(name), "%u", iter.tgid); 3330 ctx->pos = iter.tgid + TGID_OFFSET; 3331 if (!proc_fill_cache(file, ctx, name, len, 3332 proc_pid_instantiate, iter.task, NULL)) { 3333 put_task_struct(iter.task); 3334 return 0; 3335 } 3336 } 3337 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET; 3338 return 0; 3339 } 3340 3341 /* 3342 * proc_tid_comm_permission is a special permission function exclusively 3343 * used for the node /proc/<pid>/task/<tid>/comm. 3344 * It bypasses generic permission checks in the case where a task of the same 3345 * task group attempts to access the node. 3346 * The rationale behind this is that glibc and bionic access this node for 3347 * cross thread naming (pthread_set/getname_np(!self)). However, if 3348 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0, 3349 * which locks out the cross thread naming implementation. 3350 * This function makes sure that the node is always accessible for members of 3351 * same thread group. 3352 */ 3353 static int proc_tid_comm_permission(struct inode *inode, int mask) 3354 { 3355 bool is_same_tgroup; 3356 struct task_struct *task; 3357 3358 task = get_proc_task(inode); 3359 if (!task) 3360 return -ESRCH; 3361 is_same_tgroup = same_thread_group(current, task); 3362 put_task_struct(task); 3363 3364 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) { 3365 /* This file (/proc/<pid>/task/<tid>/comm) can always be 3366 * read or written by the members of the corresponding 3367 * thread group. 3368 */ 3369 return 0; 3370 } 3371 3372 return generic_permission(inode, mask); 3373 } 3374 3375 static const struct inode_operations proc_tid_comm_inode_operations = { 3376 .permission = proc_tid_comm_permission, 3377 }; 3378 3379 /* 3380 * Tasks 3381 */ 3382 static const struct pid_entry tid_base_stuff[] = { 3383 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3384 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3385 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3386 #ifdef CONFIG_NET 3387 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3388 #endif 3389 REG("environ", S_IRUSR, proc_environ_operations), 3390 REG("auxv", S_IRUSR, proc_auxv_operations), 3391 ONE("status", S_IRUGO, proc_pid_status), 3392 ONE("personality", S_IRUSR, proc_pid_personality), 3393 ONE("limits", S_IRUGO, proc_pid_limits), 3394 #ifdef CONFIG_SCHED_DEBUG 3395 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3396 #endif 3397 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR, 3398 &proc_tid_comm_inode_operations, 3399 &proc_pid_set_comm_operations, {}), 3400 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3401 ONE("syscall", S_IRUSR, proc_pid_syscall), 3402 #endif 3403 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 3404 ONE("stat", S_IRUGO, proc_tid_stat), 3405 ONE("statm", S_IRUGO, proc_pid_statm), 3406 REG("maps", S_IRUGO, proc_pid_maps_operations), 3407 #ifdef CONFIG_PROC_CHILDREN 3408 REG("children", S_IRUGO, proc_tid_children_operations), 3409 #endif 3410 #ifdef CONFIG_NUMA 3411 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 3412 #endif 3413 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3414 LNK("cwd", proc_cwd_link), 3415 LNK("root", proc_root_link), 3416 LNK("exe", proc_exe_link), 3417 REG("mounts", S_IRUGO, proc_mounts_operations), 3418 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3419 #ifdef CONFIG_PROC_PAGE_MONITOR 3420 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3421 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 3422 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations), 3423 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3424 #endif 3425 #ifdef CONFIG_SECURITY 3426 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3427 #endif 3428 #ifdef CONFIG_KALLSYMS 3429 ONE("wchan", S_IRUGO, proc_pid_wchan), 3430 #endif 3431 #ifdef CONFIG_STACKTRACE 3432 ONE("stack", S_IRUSR, proc_pid_stack), 3433 #endif 3434 #ifdef CONFIG_SCHED_INFO 3435 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 3436 #endif 3437 #ifdef CONFIG_LATENCYTOP 3438 REG("latency", S_IRUGO, proc_lstats_operations), 3439 #endif 3440 #ifdef CONFIG_PROC_PID_CPUSET 3441 ONE("cpuset", S_IRUGO, proc_cpuset_show), 3442 #endif 3443 #ifdef CONFIG_CGROUPS 3444 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3445 #endif 3446 ONE("oom_score", S_IRUGO, proc_oom_score), 3447 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3448 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3449 #ifdef CONFIG_AUDIT 3450 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3451 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3452 #endif 3453 #ifdef CONFIG_FAULT_INJECTION 3454 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3455 REG("fail-nth", 0644, proc_fail_nth_operations), 3456 #endif 3457 #ifdef CONFIG_TASK_IO_ACCOUNTING 3458 ONE("io", S_IRUSR, proc_tid_io_accounting), 3459 #endif 3460 #ifdef CONFIG_USER_NS 3461 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3462 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3463 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3464 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3465 #endif 3466 #ifdef CONFIG_LIVEPATCH 3467 ONE("patch_state", S_IRUSR, proc_pid_patch_state), 3468 #endif 3469 #ifdef CONFIG_PROC_PID_ARCH_STATUS 3470 ONE("arch_status", S_IRUGO, proc_pid_arch_status), 3471 #endif 3472 }; 3473 3474 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx) 3475 { 3476 return proc_pident_readdir(file, ctx, 3477 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3478 } 3479 3480 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3481 { 3482 return proc_pident_lookup(dir, dentry, 3483 tid_base_stuff, 3484 tid_base_stuff + ARRAY_SIZE(tid_base_stuff)); 3485 } 3486 3487 static const struct file_operations proc_tid_base_operations = { 3488 .read = generic_read_dir, 3489 .iterate_shared = proc_tid_base_readdir, 3490 .llseek = generic_file_llseek, 3491 }; 3492 3493 static const struct inode_operations proc_tid_base_inode_operations = { 3494 .lookup = proc_tid_base_lookup, 3495 .getattr = pid_getattr, 3496 .setattr = proc_setattr, 3497 }; 3498 3499 static struct dentry *proc_task_instantiate(struct dentry *dentry, 3500 struct task_struct *task, const void *ptr) 3501 { 3502 struct inode *inode; 3503 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3504 if (!inode) 3505 return ERR_PTR(-ENOENT); 3506 3507 inode->i_op = &proc_tid_base_inode_operations; 3508 inode->i_fop = &proc_tid_base_operations; 3509 inode->i_flags |= S_IMMUTABLE; 3510 3511 set_nlink(inode, nlink_tid); 3512 pid_update_inode(task, inode); 3513 3514 d_set_d_op(dentry, &pid_dentry_operations); 3515 return d_splice_alias(inode, dentry); 3516 } 3517 3518 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3519 { 3520 struct task_struct *task; 3521 struct task_struct *leader = get_proc_task(dir); 3522 unsigned tid; 3523 struct pid_namespace *ns; 3524 struct dentry *result = ERR_PTR(-ENOENT); 3525 3526 if (!leader) 3527 goto out_no_task; 3528 3529 tid = name_to_int(&dentry->d_name); 3530 if (tid == ~0U) 3531 goto out; 3532 3533 ns = dentry->d_sb->s_fs_info; 3534 rcu_read_lock(); 3535 task = find_task_by_pid_ns(tid, ns); 3536 if (task) 3537 get_task_struct(task); 3538 rcu_read_unlock(); 3539 if (!task) 3540 goto out; 3541 if (!same_thread_group(leader, task)) 3542 goto out_drop_task; 3543 3544 result = proc_task_instantiate(dentry, task, NULL); 3545 out_drop_task: 3546 put_task_struct(task); 3547 out: 3548 put_task_struct(leader); 3549 out_no_task: 3550 return result; 3551 } 3552 3553 /* 3554 * Find the first tid of a thread group to return to user space. 3555 * 3556 * Usually this is just the thread group leader, but if the users 3557 * buffer was too small or there was a seek into the middle of the 3558 * directory we have more work todo. 3559 * 3560 * In the case of a short read we start with find_task_by_pid. 3561 * 3562 * In the case of a seek we start with the leader and walk nr 3563 * threads past it. 3564 */ 3565 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos, 3566 struct pid_namespace *ns) 3567 { 3568 struct task_struct *pos, *task; 3569 unsigned long nr = f_pos; 3570 3571 if (nr != f_pos) /* 32bit overflow? */ 3572 return NULL; 3573 3574 rcu_read_lock(); 3575 task = pid_task(pid, PIDTYPE_PID); 3576 if (!task) 3577 goto fail; 3578 3579 /* Attempt to start with the tid of a thread */ 3580 if (tid && nr) { 3581 pos = find_task_by_pid_ns(tid, ns); 3582 if (pos && same_thread_group(pos, task)) 3583 goto found; 3584 } 3585 3586 /* If nr exceeds the number of threads there is nothing todo */ 3587 if (nr >= get_nr_threads(task)) 3588 goto fail; 3589 3590 /* If we haven't found our starting place yet start 3591 * with the leader and walk nr threads forward. 3592 */ 3593 pos = task = task->group_leader; 3594 do { 3595 if (!nr--) 3596 goto found; 3597 } while_each_thread(task, pos); 3598 fail: 3599 pos = NULL; 3600 goto out; 3601 found: 3602 get_task_struct(pos); 3603 out: 3604 rcu_read_unlock(); 3605 return pos; 3606 } 3607 3608 /* 3609 * Find the next thread in the thread list. 3610 * Return NULL if there is an error or no next thread. 3611 * 3612 * The reference to the input task_struct is released. 3613 */ 3614 static struct task_struct *next_tid(struct task_struct *start) 3615 { 3616 struct task_struct *pos = NULL; 3617 rcu_read_lock(); 3618 if (pid_alive(start)) { 3619 pos = next_thread(start); 3620 if (thread_group_leader(pos)) 3621 pos = NULL; 3622 else 3623 get_task_struct(pos); 3624 } 3625 rcu_read_unlock(); 3626 put_task_struct(start); 3627 return pos; 3628 } 3629 3630 /* for the /proc/TGID/task/ directories */ 3631 static int proc_task_readdir(struct file *file, struct dir_context *ctx) 3632 { 3633 struct inode *inode = file_inode(file); 3634 struct task_struct *task; 3635 struct pid_namespace *ns; 3636 int tid; 3637 3638 if (proc_inode_is_dead(inode)) 3639 return -ENOENT; 3640 3641 if (!dir_emit_dots(file, ctx)) 3642 return 0; 3643 3644 /* f_version caches the tgid value that the last readdir call couldn't 3645 * return. lseek aka telldir automagically resets f_version to 0. 3646 */ 3647 ns = proc_pid_ns(inode); 3648 tid = (int)file->f_version; 3649 file->f_version = 0; 3650 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); 3651 task; 3652 task = next_tid(task), ctx->pos++) { 3653 char name[10 + 1]; 3654 unsigned int len; 3655 tid = task_pid_nr_ns(task, ns); 3656 len = snprintf(name, sizeof(name), "%u", tid); 3657 if (!proc_fill_cache(file, ctx, name, len, 3658 proc_task_instantiate, task, NULL)) { 3659 /* returning this tgid failed, save it as the first 3660 * pid for the next readir call */ 3661 file->f_version = (u64)tid; 3662 put_task_struct(task); 3663 break; 3664 } 3665 } 3666 3667 return 0; 3668 } 3669 3670 static int proc_task_getattr(const struct path *path, struct kstat *stat, 3671 u32 request_mask, unsigned int query_flags) 3672 { 3673 struct inode *inode = d_inode(path->dentry); 3674 struct task_struct *p = get_proc_task(inode); 3675 generic_fillattr(inode, stat); 3676 3677 if (p) { 3678 stat->nlink += get_nr_threads(p); 3679 put_task_struct(p); 3680 } 3681 3682 return 0; 3683 } 3684 3685 static const struct inode_operations proc_task_inode_operations = { 3686 .lookup = proc_task_lookup, 3687 .getattr = proc_task_getattr, 3688 .setattr = proc_setattr, 3689 .permission = proc_pid_permission, 3690 }; 3691 3692 static const struct file_operations proc_task_operations = { 3693 .read = generic_read_dir, 3694 .iterate_shared = proc_task_readdir, 3695 .llseek = generic_file_llseek, 3696 }; 3697 3698 void __init set_proc_pid_nlink(void) 3699 { 3700 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3701 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3702 } 3703