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 <linux/time_namespace.h> 98 #include <linux/resctrl.h> 99 #include <trace/events/oom.h> 100 #include "internal.h" 101 #include "fd.h" 102 103 #include "../../lib/kstrtox.h" 104 105 /* NOTE: 106 * Implementing inode permission operations in /proc is almost 107 * certainly an error. Permission checks need to happen during 108 * each system call not at open time. The reason is that most of 109 * what we wish to check for permissions in /proc varies at runtime. 110 * 111 * The classic example of a problem is opening file descriptors 112 * in /proc for a task before it execs a suid executable. 113 */ 114 115 static u8 nlink_tid __ro_after_init; 116 static u8 nlink_tgid __ro_after_init; 117 118 struct pid_entry { 119 const char *name; 120 unsigned int len; 121 umode_t mode; 122 const struct inode_operations *iop; 123 const struct file_operations *fop; 124 union proc_op op; 125 }; 126 127 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 128 .name = (NAME), \ 129 .len = sizeof(NAME) - 1, \ 130 .mode = MODE, \ 131 .iop = IOP, \ 132 .fop = FOP, \ 133 .op = OP, \ 134 } 135 136 #define DIR(NAME, MODE, iops, fops) \ 137 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} ) 138 #define LNK(NAME, get_link) \ 139 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 140 &proc_pid_link_inode_operations, NULL, \ 141 { .proc_get_link = get_link } ) 142 #define REG(NAME, MODE, fops) \ 143 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {}) 144 #define ONE(NAME, MODE, show) \ 145 NOD(NAME, (S_IFREG|(MODE)), \ 146 NULL, &proc_single_file_operations, \ 147 { .proc_show = show } ) 148 #define ATTR(LSM, NAME, MODE) \ 149 NOD(NAME, (S_IFREG|(MODE)), \ 150 NULL, &proc_pid_attr_operations, \ 151 { .lsm = LSM }) 152 153 /* 154 * Count the number of hardlinks for the pid_entry table, excluding the . 155 * and .. links. 156 */ 157 static unsigned int __init pid_entry_nlink(const struct pid_entry *entries, 158 unsigned int n) 159 { 160 unsigned int i; 161 unsigned int count; 162 163 count = 2; 164 for (i = 0; i < n; ++i) { 165 if (S_ISDIR(entries[i].mode)) 166 ++count; 167 } 168 169 return count; 170 } 171 172 static int get_task_root(struct task_struct *task, struct path *root) 173 { 174 int result = -ENOENT; 175 176 task_lock(task); 177 if (task->fs) { 178 get_fs_root(task->fs, root); 179 result = 0; 180 } 181 task_unlock(task); 182 return result; 183 } 184 185 static int proc_cwd_link(struct dentry *dentry, struct path *path) 186 { 187 struct task_struct *task = get_proc_task(d_inode(dentry)); 188 int result = -ENOENT; 189 190 if (task) { 191 task_lock(task); 192 if (task->fs) { 193 get_fs_pwd(task->fs, path); 194 result = 0; 195 } 196 task_unlock(task); 197 put_task_struct(task); 198 } 199 return result; 200 } 201 202 static int proc_root_link(struct dentry *dentry, struct path *path) 203 { 204 struct task_struct *task = get_proc_task(d_inode(dentry)); 205 int result = -ENOENT; 206 207 if (task) { 208 result = get_task_root(task, path); 209 put_task_struct(task); 210 } 211 return result; 212 } 213 214 /* 215 * If the user used setproctitle(), we just get the string from 216 * user space at arg_start, and limit it to a maximum of one page. 217 */ 218 static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf, 219 size_t count, unsigned long pos, 220 unsigned long arg_start) 221 { 222 char *page; 223 int ret, got; 224 225 if (pos >= PAGE_SIZE) 226 return 0; 227 228 page = (char *)__get_free_page(GFP_KERNEL); 229 if (!page) 230 return -ENOMEM; 231 232 ret = 0; 233 got = access_remote_vm(mm, arg_start, page, PAGE_SIZE, FOLL_ANON); 234 if (got > 0) { 235 int len = strnlen(page, got); 236 237 /* Include the NUL character if it was found */ 238 if (len < got) 239 len++; 240 241 if (len > pos) { 242 len -= pos; 243 if (len > count) 244 len = count; 245 len -= copy_to_user(buf, page+pos, len); 246 if (!len) 247 len = -EFAULT; 248 ret = len; 249 } 250 } 251 free_page((unsigned long)page); 252 return ret; 253 } 254 255 static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf, 256 size_t count, loff_t *ppos) 257 { 258 unsigned long arg_start, arg_end, env_start, env_end; 259 unsigned long pos, len; 260 char *page, c; 261 262 /* Check if process spawned far enough to have cmdline. */ 263 if (!mm->env_end) 264 return 0; 265 266 spin_lock(&mm->arg_lock); 267 arg_start = mm->arg_start; 268 arg_end = mm->arg_end; 269 env_start = mm->env_start; 270 env_end = mm->env_end; 271 spin_unlock(&mm->arg_lock); 272 273 if (arg_start >= arg_end) 274 return 0; 275 276 /* 277 * We allow setproctitle() to overwrite the argument 278 * strings, and overflow past the original end. But 279 * only when it overflows into the environment area. 280 */ 281 if (env_start != arg_end || env_end < env_start) 282 env_start = env_end = arg_end; 283 len = env_end - arg_start; 284 285 /* We're not going to care if "*ppos" has high bits set */ 286 pos = *ppos; 287 if (pos >= len) 288 return 0; 289 if (count > len - pos) 290 count = len - pos; 291 if (!count) 292 return 0; 293 294 /* 295 * Magical special case: if the argv[] end byte is not 296 * zero, the user has overwritten it with setproctitle(3). 297 * 298 * Possible future enhancement: do this only once when 299 * pos is 0, and set a flag in the 'struct file'. 300 */ 301 if (access_remote_vm(mm, arg_end-1, &c, 1, FOLL_ANON) == 1 && c) 302 return get_mm_proctitle(mm, buf, count, pos, arg_start); 303 304 /* 305 * For the non-setproctitle() case we limit things strictly 306 * to the [arg_start, arg_end[ range. 307 */ 308 pos += arg_start; 309 if (pos < arg_start || pos >= arg_end) 310 return 0; 311 if (count > arg_end - pos) 312 count = arg_end - pos; 313 314 page = (char *)__get_free_page(GFP_KERNEL); 315 if (!page) 316 return -ENOMEM; 317 318 len = 0; 319 while (count) { 320 int got; 321 size_t size = min_t(size_t, PAGE_SIZE, count); 322 323 got = access_remote_vm(mm, pos, page, size, FOLL_ANON); 324 if (got <= 0) 325 break; 326 got -= copy_to_user(buf, page, got); 327 if (unlikely(!got)) { 328 if (!len) 329 len = -EFAULT; 330 break; 331 } 332 pos += got; 333 buf += got; 334 len += got; 335 count -= got; 336 } 337 338 free_page((unsigned long)page); 339 return len; 340 } 341 342 static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf, 343 size_t count, loff_t *pos) 344 { 345 struct mm_struct *mm; 346 ssize_t ret; 347 348 mm = get_task_mm(tsk); 349 if (!mm) 350 return 0; 351 352 ret = get_mm_cmdline(mm, buf, count, pos); 353 mmput(mm); 354 return ret; 355 } 356 357 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, 358 size_t count, loff_t *pos) 359 { 360 struct task_struct *tsk; 361 ssize_t ret; 362 363 BUG_ON(*pos < 0); 364 365 tsk = get_proc_task(file_inode(file)); 366 if (!tsk) 367 return -ESRCH; 368 ret = get_task_cmdline(tsk, buf, count, pos); 369 put_task_struct(tsk); 370 if (ret > 0) 371 *pos += ret; 372 return ret; 373 } 374 375 static const struct file_operations proc_pid_cmdline_ops = { 376 .read = proc_pid_cmdline_read, 377 .llseek = generic_file_llseek, 378 }; 379 380 #ifdef CONFIG_KALLSYMS 381 /* 382 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 383 * Returns the resolved symbol. If that fails, simply return the address. 384 */ 385 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns, 386 struct pid *pid, struct task_struct *task) 387 { 388 unsigned long wchan; 389 char symname[KSYM_NAME_LEN]; 390 391 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 392 goto print0; 393 394 wchan = get_wchan(task); 395 if (wchan && !lookup_symbol_name(wchan, symname)) { 396 seq_puts(m, symname); 397 return 0; 398 } 399 400 print0: 401 seq_putc(m, '0'); 402 return 0; 403 } 404 #endif /* CONFIG_KALLSYMS */ 405 406 static int lock_trace(struct task_struct *task) 407 { 408 int err = mutex_lock_killable(&task->signal->cred_guard_mutex); 409 if (err) 410 return err; 411 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) { 412 mutex_unlock(&task->signal->cred_guard_mutex); 413 return -EPERM; 414 } 415 return 0; 416 } 417 418 static void unlock_trace(struct task_struct *task) 419 { 420 mutex_unlock(&task->signal->cred_guard_mutex); 421 } 422 423 #ifdef CONFIG_STACKTRACE 424 425 #define MAX_STACK_TRACE_DEPTH 64 426 427 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, 428 struct pid *pid, struct task_struct *task) 429 { 430 unsigned long *entries; 431 int err; 432 433 /* 434 * The ability to racily run the kernel stack unwinder on a running task 435 * and then observe the unwinder output is scary; while it is useful for 436 * debugging kernel issues, it can also allow an attacker to leak kernel 437 * stack contents. 438 * Doing this in a manner that is at least safe from races would require 439 * some work to ensure that the remote task can not be scheduled; and 440 * even then, this would still expose the unwinder as local attack 441 * surface. 442 * Therefore, this interface is restricted to root. 443 */ 444 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) 445 return -EACCES; 446 447 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries), 448 GFP_KERNEL); 449 if (!entries) 450 return -ENOMEM; 451 452 err = lock_trace(task); 453 if (!err) { 454 unsigned int i, nr_entries; 455 456 nr_entries = stack_trace_save_tsk(task, entries, 457 MAX_STACK_TRACE_DEPTH, 0); 458 459 for (i = 0; i < nr_entries; i++) { 460 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]); 461 } 462 463 unlock_trace(task); 464 } 465 kfree(entries); 466 467 return err; 468 } 469 #endif 470 471 #ifdef CONFIG_SCHED_INFO 472 /* 473 * Provides /proc/PID/schedstat 474 */ 475 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, 476 struct pid *pid, struct task_struct *task) 477 { 478 if (unlikely(!sched_info_on())) 479 seq_puts(m, "0 0 0\n"); 480 else 481 seq_printf(m, "%llu %llu %lu\n", 482 (unsigned long long)task->se.sum_exec_runtime, 483 (unsigned long long)task->sched_info.run_delay, 484 task->sched_info.pcount); 485 486 return 0; 487 } 488 #endif 489 490 #ifdef CONFIG_LATENCYTOP 491 static int lstats_show_proc(struct seq_file *m, void *v) 492 { 493 int i; 494 struct inode *inode = m->private; 495 struct task_struct *task = get_proc_task(inode); 496 497 if (!task) 498 return -ESRCH; 499 seq_puts(m, "Latency Top version : v0.1\n"); 500 for (i = 0; i < LT_SAVECOUNT; i++) { 501 struct latency_record *lr = &task->latency_record[i]; 502 if (lr->backtrace[0]) { 503 int q; 504 seq_printf(m, "%i %li %li", 505 lr->count, lr->time, lr->max); 506 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 507 unsigned long bt = lr->backtrace[q]; 508 509 if (!bt) 510 break; 511 seq_printf(m, " %ps", (void *)bt); 512 } 513 seq_putc(m, '\n'); 514 } 515 516 } 517 put_task_struct(task); 518 return 0; 519 } 520 521 static int lstats_open(struct inode *inode, struct file *file) 522 { 523 return single_open(file, lstats_show_proc, inode); 524 } 525 526 static ssize_t lstats_write(struct file *file, const char __user *buf, 527 size_t count, loff_t *offs) 528 { 529 struct task_struct *task = get_proc_task(file_inode(file)); 530 531 if (!task) 532 return -ESRCH; 533 clear_tsk_latency_tracing(task); 534 put_task_struct(task); 535 536 return count; 537 } 538 539 static const struct file_operations proc_lstats_operations = { 540 .open = lstats_open, 541 .read = seq_read, 542 .write = lstats_write, 543 .llseek = seq_lseek, 544 .release = single_release, 545 }; 546 547 #endif 548 549 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns, 550 struct pid *pid, struct task_struct *task) 551 { 552 unsigned long totalpages = totalram_pages() + total_swap_pages; 553 unsigned long points = 0; 554 555 points = oom_badness(task, totalpages) * 1000 / totalpages; 556 seq_printf(m, "%lu\n", points); 557 558 return 0; 559 } 560 561 struct limit_names { 562 const char *name; 563 const char *unit; 564 }; 565 566 static const struct limit_names lnames[RLIM_NLIMITS] = { 567 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 568 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 569 [RLIMIT_DATA] = {"Max data size", "bytes"}, 570 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 571 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 572 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 573 [RLIMIT_NPROC] = {"Max processes", "processes"}, 574 [RLIMIT_NOFILE] = {"Max open files", "files"}, 575 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 576 [RLIMIT_AS] = {"Max address space", "bytes"}, 577 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 578 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 579 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 580 [RLIMIT_NICE] = {"Max nice priority", NULL}, 581 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 582 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 583 }; 584 585 /* Display limits for a process */ 586 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns, 587 struct pid *pid, struct task_struct *task) 588 { 589 unsigned int i; 590 unsigned long flags; 591 592 struct rlimit rlim[RLIM_NLIMITS]; 593 594 if (!lock_task_sighand(task, &flags)) 595 return 0; 596 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 597 unlock_task_sighand(task, &flags); 598 599 /* 600 * print the file header 601 */ 602 seq_puts(m, "Limit " 603 "Soft Limit " 604 "Hard Limit " 605 "Units \n"); 606 607 for (i = 0; i < RLIM_NLIMITS; i++) { 608 if (rlim[i].rlim_cur == RLIM_INFINITY) 609 seq_printf(m, "%-25s %-20s ", 610 lnames[i].name, "unlimited"); 611 else 612 seq_printf(m, "%-25s %-20lu ", 613 lnames[i].name, rlim[i].rlim_cur); 614 615 if (rlim[i].rlim_max == RLIM_INFINITY) 616 seq_printf(m, "%-20s ", "unlimited"); 617 else 618 seq_printf(m, "%-20lu ", rlim[i].rlim_max); 619 620 if (lnames[i].unit) 621 seq_printf(m, "%-10s\n", lnames[i].unit); 622 else 623 seq_putc(m, '\n'); 624 } 625 626 return 0; 627 } 628 629 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 630 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns, 631 struct pid *pid, struct task_struct *task) 632 { 633 struct syscall_info info; 634 u64 *args = &info.data.args[0]; 635 int res; 636 637 res = lock_trace(task); 638 if (res) 639 return res; 640 641 if (task_current_syscall(task, &info)) 642 seq_puts(m, "running\n"); 643 else if (info.data.nr < 0) 644 seq_printf(m, "%d 0x%llx 0x%llx\n", 645 info.data.nr, info.sp, info.data.instruction_pointer); 646 else 647 seq_printf(m, 648 "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n", 649 info.data.nr, 650 args[0], args[1], args[2], args[3], args[4], args[5], 651 info.sp, info.data.instruction_pointer); 652 unlock_trace(task); 653 654 return 0; 655 } 656 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 657 658 /************************************************************************/ 659 /* Here the fs part begins */ 660 /************************************************************************/ 661 662 /* permission checks */ 663 static int proc_fd_access_allowed(struct inode *inode) 664 { 665 struct task_struct *task; 666 int allowed = 0; 667 /* Allow access to a task's file descriptors if it is us or we 668 * may use ptrace attach to the process and find out that 669 * information. 670 */ 671 task = get_proc_task(inode); 672 if (task) { 673 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 674 put_task_struct(task); 675 } 676 return allowed; 677 } 678 679 int proc_setattr(struct dentry *dentry, struct iattr *attr) 680 { 681 int error; 682 struct inode *inode = d_inode(dentry); 683 684 if (attr->ia_valid & ATTR_MODE) 685 return -EPERM; 686 687 error = setattr_prepare(dentry, attr); 688 if (error) 689 return error; 690 691 setattr_copy(inode, attr); 692 mark_inode_dirty(inode); 693 return 0; 694 } 695 696 /* 697 * May current process learn task's sched/cmdline info (for hide_pid_min=1) 698 * or euid/egid (for hide_pid_min=2)? 699 */ 700 static bool has_pid_permissions(struct pid_namespace *pid, 701 struct task_struct *task, 702 int hide_pid_min) 703 { 704 if (pid->hide_pid < hide_pid_min) 705 return true; 706 if (in_group_p(pid->pid_gid)) 707 return true; 708 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); 709 } 710 711 712 static int proc_pid_permission(struct inode *inode, int mask) 713 { 714 struct pid_namespace *pid = proc_pid_ns(inode); 715 struct task_struct *task; 716 bool has_perms; 717 718 task = get_proc_task(inode); 719 if (!task) 720 return -ESRCH; 721 has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS); 722 put_task_struct(task); 723 724 if (!has_perms) { 725 if (pid->hide_pid == HIDEPID_INVISIBLE) { 726 /* 727 * Let's make getdents(), stat(), and open() 728 * consistent with each other. If a process 729 * may not stat() a file, it shouldn't be seen 730 * in procfs at all. 731 */ 732 return -ENOENT; 733 } 734 735 return -EPERM; 736 } 737 return generic_permission(inode, mask); 738 } 739 740 741 742 static const struct inode_operations proc_def_inode_operations = { 743 .setattr = proc_setattr, 744 }; 745 746 static int proc_single_show(struct seq_file *m, void *v) 747 { 748 struct inode *inode = m->private; 749 struct pid_namespace *ns = proc_pid_ns(inode); 750 struct pid *pid = proc_pid(inode); 751 struct task_struct *task; 752 int ret; 753 754 task = get_pid_task(pid, PIDTYPE_PID); 755 if (!task) 756 return -ESRCH; 757 758 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 759 760 put_task_struct(task); 761 return ret; 762 } 763 764 static int proc_single_open(struct inode *inode, struct file *filp) 765 { 766 return single_open(filp, proc_single_show, inode); 767 } 768 769 static const struct file_operations proc_single_file_operations = { 770 .open = proc_single_open, 771 .read = seq_read, 772 .llseek = seq_lseek, 773 .release = single_release, 774 }; 775 776 777 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode) 778 { 779 struct task_struct *task = get_proc_task(inode); 780 struct mm_struct *mm = ERR_PTR(-ESRCH); 781 782 if (task) { 783 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS); 784 put_task_struct(task); 785 786 if (!IS_ERR_OR_NULL(mm)) { 787 /* ensure this mm_struct can't be freed */ 788 mmgrab(mm); 789 /* but do not pin its memory */ 790 mmput(mm); 791 } 792 } 793 794 return mm; 795 } 796 797 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) 798 { 799 struct mm_struct *mm = proc_mem_open(inode, mode); 800 801 if (IS_ERR(mm)) 802 return PTR_ERR(mm); 803 804 file->private_data = mm; 805 return 0; 806 } 807 808 static int mem_open(struct inode *inode, struct file *file) 809 { 810 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH); 811 812 /* OK to pass negative loff_t, we can catch out-of-range */ 813 file->f_mode |= FMODE_UNSIGNED_OFFSET; 814 815 return ret; 816 } 817 818 static ssize_t mem_rw(struct file *file, char __user *buf, 819 size_t count, loff_t *ppos, int write) 820 { 821 struct mm_struct *mm = file->private_data; 822 unsigned long addr = *ppos; 823 ssize_t copied; 824 char *page; 825 unsigned int flags; 826 827 if (!mm) 828 return 0; 829 830 page = (char *)__get_free_page(GFP_KERNEL); 831 if (!page) 832 return -ENOMEM; 833 834 copied = 0; 835 if (!mmget_not_zero(mm)) 836 goto free; 837 838 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0); 839 840 while (count > 0) { 841 int this_len = min_t(int, count, PAGE_SIZE); 842 843 if (write && copy_from_user(page, buf, this_len)) { 844 copied = -EFAULT; 845 break; 846 } 847 848 this_len = access_remote_vm(mm, addr, page, this_len, flags); 849 if (!this_len) { 850 if (!copied) 851 copied = -EIO; 852 break; 853 } 854 855 if (!write && copy_to_user(buf, page, this_len)) { 856 copied = -EFAULT; 857 break; 858 } 859 860 buf += this_len; 861 addr += this_len; 862 copied += this_len; 863 count -= this_len; 864 } 865 *ppos = addr; 866 867 mmput(mm); 868 free: 869 free_page((unsigned long) page); 870 return copied; 871 } 872 873 static ssize_t mem_read(struct file *file, char __user *buf, 874 size_t count, loff_t *ppos) 875 { 876 return mem_rw(file, buf, count, ppos, 0); 877 } 878 879 static ssize_t mem_write(struct file *file, const char __user *buf, 880 size_t count, loff_t *ppos) 881 { 882 return mem_rw(file, (char __user*)buf, count, ppos, 1); 883 } 884 885 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 886 { 887 switch (orig) { 888 case 0: 889 file->f_pos = offset; 890 break; 891 case 1: 892 file->f_pos += offset; 893 break; 894 default: 895 return -EINVAL; 896 } 897 force_successful_syscall_return(); 898 return file->f_pos; 899 } 900 901 static int mem_release(struct inode *inode, struct file *file) 902 { 903 struct mm_struct *mm = file->private_data; 904 if (mm) 905 mmdrop(mm); 906 return 0; 907 } 908 909 static const struct file_operations proc_mem_operations = { 910 .llseek = mem_lseek, 911 .read = mem_read, 912 .write = mem_write, 913 .open = mem_open, 914 .release = mem_release, 915 }; 916 917 static int environ_open(struct inode *inode, struct file *file) 918 { 919 return __mem_open(inode, file, PTRACE_MODE_READ); 920 } 921 922 static ssize_t environ_read(struct file *file, char __user *buf, 923 size_t count, loff_t *ppos) 924 { 925 char *page; 926 unsigned long src = *ppos; 927 int ret = 0; 928 struct mm_struct *mm = file->private_data; 929 unsigned long env_start, env_end; 930 931 /* Ensure the process spawned far enough to have an environment. */ 932 if (!mm || !mm->env_end) 933 return 0; 934 935 page = (char *)__get_free_page(GFP_KERNEL); 936 if (!page) 937 return -ENOMEM; 938 939 ret = 0; 940 if (!mmget_not_zero(mm)) 941 goto free; 942 943 spin_lock(&mm->arg_lock); 944 env_start = mm->env_start; 945 env_end = mm->env_end; 946 spin_unlock(&mm->arg_lock); 947 948 while (count > 0) { 949 size_t this_len, max_len; 950 int retval; 951 952 if (src >= (env_end - env_start)) 953 break; 954 955 this_len = env_end - (env_start + src); 956 957 max_len = min_t(size_t, PAGE_SIZE, count); 958 this_len = min(max_len, this_len); 959 960 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON); 961 962 if (retval <= 0) { 963 ret = retval; 964 break; 965 } 966 967 if (copy_to_user(buf, page, retval)) { 968 ret = -EFAULT; 969 break; 970 } 971 972 ret += retval; 973 src += retval; 974 buf += retval; 975 count -= retval; 976 } 977 *ppos = src; 978 mmput(mm); 979 980 free: 981 free_page((unsigned long) page); 982 return ret; 983 } 984 985 static const struct file_operations proc_environ_operations = { 986 .open = environ_open, 987 .read = environ_read, 988 .llseek = generic_file_llseek, 989 .release = mem_release, 990 }; 991 992 static int auxv_open(struct inode *inode, struct file *file) 993 { 994 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS); 995 } 996 997 static ssize_t auxv_read(struct file *file, char __user *buf, 998 size_t count, loff_t *ppos) 999 { 1000 struct mm_struct *mm = file->private_data; 1001 unsigned int nwords = 0; 1002 1003 if (!mm) 1004 return 0; 1005 do { 1006 nwords += 2; 1007 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 1008 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv, 1009 nwords * sizeof(mm->saved_auxv[0])); 1010 } 1011 1012 static const struct file_operations proc_auxv_operations = { 1013 .open = auxv_open, 1014 .read = auxv_read, 1015 .llseek = generic_file_llseek, 1016 .release = mem_release, 1017 }; 1018 1019 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count, 1020 loff_t *ppos) 1021 { 1022 struct task_struct *task = get_proc_task(file_inode(file)); 1023 char buffer[PROC_NUMBUF]; 1024 int oom_adj = OOM_ADJUST_MIN; 1025 size_t len; 1026 1027 if (!task) 1028 return -ESRCH; 1029 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX) 1030 oom_adj = OOM_ADJUST_MAX; 1031 else 1032 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) / 1033 OOM_SCORE_ADJ_MAX; 1034 put_task_struct(task); 1035 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj); 1036 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1037 } 1038 1039 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy) 1040 { 1041 static DEFINE_MUTEX(oom_adj_mutex); 1042 struct mm_struct *mm = NULL; 1043 struct task_struct *task; 1044 int err = 0; 1045 1046 task = get_proc_task(file_inode(file)); 1047 if (!task) 1048 return -ESRCH; 1049 1050 mutex_lock(&oom_adj_mutex); 1051 if (legacy) { 1052 if (oom_adj < task->signal->oom_score_adj && 1053 !capable(CAP_SYS_RESOURCE)) { 1054 err = -EACCES; 1055 goto err_unlock; 1056 } 1057 /* 1058 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use 1059 * /proc/pid/oom_score_adj instead. 1060 */ 1061 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 1062 current->comm, task_pid_nr(current), task_pid_nr(task), 1063 task_pid_nr(task)); 1064 } else { 1065 if ((short)oom_adj < task->signal->oom_score_adj_min && 1066 !capable(CAP_SYS_RESOURCE)) { 1067 err = -EACCES; 1068 goto err_unlock; 1069 } 1070 } 1071 1072 /* 1073 * Make sure we will check other processes sharing the mm if this is 1074 * not vfrok which wants its own oom_score_adj. 1075 * pin the mm so it doesn't go away and get reused after task_unlock 1076 */ 1077 if (!task->vfork_done) { 1078 struct task_struct *p = find_lock_task_mm(task); 1079 1080 if (p) { 1081 if (atomic_read(&p->mm->mm_users) > 1) { 1082 mm = p->mm; 1083 mmgrab(mm); 1084 } 1085 task_unlock(p); 1086 } 1087 } 1088 1089 task->signal->oom_score_adj = oom_adj; 1090 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1091 task->signal->oom_score_adj_min = (short)oom_adj; 1092 trace_oom_score_adj_update(task); 1093 1094 if (mm) { 1095 struct task_struct *p; 1096 1097 rcu_read_lock(); 1098 for_each_process(p) { 1099 if (same_thread_group(task, p)) 1100 continue; 1101 1102 /* do not touch kernel threads or the global init */ 1103 if (p->flags & PF_KTHREAD || is_global_init(p)) 1104 continue; 1105 1106 task_lock(p); 1107 if (!p->vfork_done && process_shares_mm(p, mm)) { 1108 p->signal->oom_score_adj = oom_adj; 1109 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1110 p->signal->oom_score_adj_min = (short)oom_adj; 1111 } 1112 task_unlock(p); 1113 } 1114 rcu_read_unlock(); 1115 mmdrop(mm); 1116 } 1117 err_unlock: 1118 mutex_unlock(&oom_adj_mutex); 1119 put_task_struct(task); 1120 return err; 1121 } 1122 1123 /* 1124 * /proc/pid/oom_adj exists solely for backwards compatibility with previous 1125 * kernels. The effective policy is defined by oom_score_adj, which has a 1126 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly. 1127 * Values written to oom_adj are simply mapped linearly to oom_score_adj. 1128 * Processes that become oom disabled via oom_adj will still be oom disabled 1129 * with this implementation. 1130 * 1131 * oom_adj cannot be removed since existing userspace binaries use it. 1132 */ 1133 static ssize_t oom_adj_write(struct file *file, const char __user *buf, 1134 size_t count, loff_t *ppos) 1135 { 1136 char buffer[PROC_NUMBUF]; 1137 int oom_adj; 1138 int err; 1139 1140 memset(buffer, 0, sizeof(buffer)); 1141 if (count > sizeof(buffer) - 1) 1142 count = sizeof(buffer) - 1; 1143 if (copy_from_user(buffer, buf, count)) { 1144 err = -EFAULT; 1145 goto out; 1146 } 1147 1148 err = kstrtoint(strstrip(buffer), 0, &oom_adj); 1149 if (err) 1150 goto out; 1151 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) && 1152 oom_adj != OOM_DISABLE) { 1153 err = -EINVAL; 1154 goto out; 1155 } 1156 1157 /* 1158 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 1159 * value is always attainable. 1160 */ 1161 if (oom_adj == OOM_ADJUST_MAX) 1162 oom_adj = OOM_SCORE_ADJ_MAX; 1163 else 1164 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE; 1165 1166 err = __set_oom_adj(file, oom_adj, true); 1167 out: 1168 return err < 0 ? err : count; 1169 } 1170 1171 static const struct file_operations proc_oom_adj_operations = { 1172 .read = oom_adj_read, 1173 .write = oom_adj_write, 1174 .llseek = generic_file_llseek, 1175 }; 1176 1177 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 1178 size_t count, loff_t *ppos) 1179 { 1180 struct task_struct *task = get_proc_task(file_inode(file)); 1181 char buffer[PROC_NUMBUF]; 1182 short oom_score_adj = OOM_SCORE_ADJ_MIN; 1183 size_t len; 1184 1185 if (!task) 1186 return -ESRCH; 1187 oom_score_adj = task->signal->oom_score_adj; 1188 put_task_struct(task); 1189 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj); 1190 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1191 } 1192 1193 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1194 size_t count, loff_t *ppos) 1195 { 1196 char buffer[PROC_NUMBUF]; 1197 int oom_score_adj; 1198 int err; 1199 1200 memset(buffer, 0, sizeof(buffer)); 1201 if (count > sizeof(buffer) - 1) 1202 count = sizeof(buffer) - 1; 1203 if (copy_from_user(buffer, buf, count)) { 1204 err = -EFAULT; 1205 goto out; 1206 } 1207 1208 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 1209 if (err) 1210 goto out; 1211 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1212 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1213 err = -EINVAL; 1214 goto out; 1215 } 1216 1217 err = __set_oom_adj(file, oom_score_adj, false); 1218 out: 1219 return err < 0 ? err : count; 1220 } 1221 1222 static const struct file_operations proc_oom_score_adj_operations = { 1223 .read = oom_score_adj_read, 1224 .write = oom_score_adj_write, 1225 .llseek = default_llseek, 1226 }; 1227 1228 #ifdef CONFIG_AUDIT 1229 #define TMPBUFLEN 11 1230 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1231 size_t count, loff_t *ppos) 1232 { 1233 struct inode * inode = file_inode(file); 1234 struct task_struct *task = get_proc_task(inode); 1235 ssize_t length; 1236 char tmpbuf[TMPBUFLEN]; 1237 1238 if (!task) 1239 return -ESRCH; 1240 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1241 from_kuid(file->f_cred->user_ns, 1242 audit_get_loginuid(task))); 1243 put_task_struct(task); 1244 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1245 } 1246 1247 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1248 size_t count, loff_t *ppos) 1249 { 1250 struct inode * inode = file_inode(file); 1251 uid_t loginuid; 1252 kuid_t kloginuid; 1253 int rv; 1254 1255 rcu_read_lock(); 1256 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1257 rcu_read_unlock(); 1258 return -EPERM; 1259 } 1260 rcu_read_unlock(); 1261 1262 if (*ppos != 0) { 1263 /* No partial writes. */ 1264 return -EINVAL; 1265 } 1266 1267 rv = kstrtou32_from_user(buf, count, 10, &loginuid); 1268 if (rv < 0) 1269 return rv; 1270 1271 /* is userspace tring to explicitly UNSET the loginuid? */ 1272 if (loginuid == AUDIT_UID_UNSET) { 1273 kloginuid = INVALID_UID; 1274 } else { 1275 kloginuid = make_kuid(file->f_cred->user_ns, loginuid); 1276 if (!uid_valid(kloginuid)) 1277 return -EINVAL; 1278 } 1279 1280 rv = audit_set_loginuid(kloginuid); 1281 if (rv < 0) 1282 return rv; 1283 return count; 1284 } 1285 1286 static const struct file_operations proc_loginuid_operations = { 1287 .read = proc_loginuid_read, 1288 .write = proc_loginuid_write, 1289 .llseek = generic_file_llseek, 1290 }; 1291 1292 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1293 size_t count, loff_t *ppos) 1294 { 1295 struct inode * inode = file_inode(file); 1296 struct task_struct *task = get_proc_task(inode); 1297 ssize_t length; 1298 char tmpbuf[TMPBUFLEN]; 1299 1300 if (!task) 1301 return -ESRCH; 1302 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1303 audit_get_sessionid(task)); 1304 put_task_struct(task); 1305 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1306 } 1307 1308 static const struct file_operations proc_sessionid_operations = { 1309 .read = proc_sessionid_read, 1310 .llseek = generic_file_llseek, 1311 }; 1312 #endif 1313 1314 #ifdef CONFIG_FAULT_INJECTION 1315 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1316 size_t count, loff_t *ppos) 1317 { 1318 struct task_struct *task = get_proc_task(file_inode(file)); 1319 char buffer[PROC_NUMBUF]; 1320 size_t len; 1321 int make_it_fail; 1322 1323 if (!task) 1324 return -ESRCH; 1325 make_it_fail = task->make_it_fail; 1326 put_task_struct(task); 1327 1328 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1329 1330 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1331 } 1332 1333 static ssize_t proc_fault_inject_write(struct file * file, 1334 const char __user * buf, size_t count, loff_t *ppos) 1335 { 1336 struct task_struct *task; 1337 char buffer[PROC_NUMBUF]; 1338 int make_it_fail; 1339 int rv; 1340 1341 if (!capable(CAP_SYS_RESOURCE)) 1342 return -EPERM; 1343 memset(buffer, 0, sizeof(buffer)); 1344 if (count > sizeof(buffer) - 1) 1345 count = sizeof(buffer) - 1; 1346 if (copy_from_user(buffer, buf, count)) 1347 return -EFAULT; 1348 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail); 1349 if (rv < 0) 1350 return rv; 1351 if (make_it_fail < 0 || make_it_fail > 1) 1352 return -EINVAL; 1353 1354 task = get_proc_task(file_inode(file)); 1355 if (!task) 1356 return -ESRCH; 1357 task->make_it_fail = make_it_fail; 1358 put_task_struct(task); 1359 1360 return count; 1361 } 1362 1363 static const struct file_operations proc_fault_inject_operations = { 1364 .read = proc_fault_inject_read, 1365 .write = proc_fault_inject_write, 1366 .llseek = generic_file_llseek, 1367 }; 1368 1369 static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf, 1370 size_t count, loff_t *ppos) 1371 { 1372 struct task_struct *task; 1373 int err; 1374 unsigned int n; 1375 1376 err = kstrtouint_from_user(buf, count, 0, &n); 1377 if (err) 1378 return err; 1379 1380 task = get_proc_task(file_inode(file)); 1381 if (!task) 1382 return -ESRCH; 1383 task->fail_nth = n; 1384 put_task_struct(task); 1385 1386 return count; 1387 } 1388 1389 static ssize_t proc_fail_nth_read(struct file *file, char __user *buf, 1390 size_t count, loff_t *ppos) 1391 { 1392 struct task_struct *task; 1393 char numbuf[PROC_NUMBUF]; 1394 ssize_t len; 1395 1396 task = get_proc_task(file_inode(file)); 1397 if (!task) 1398 return -ESRCH; 1399 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth); 1400 put_task_struct(task); 1401 return simple_read_from_buffer(buf, count, ppos, numbuf, len); 1402 } 1403 1404 static const struct file_operations proc_fail_nth_operations = { 1405 .read = proc_fail_nth_read, 1406 .write = proc_fail_nth_write, 1407 }; 1408 #endif 1409 1410 1411 #ifdef CONFIG_SCHED_DEBUG 1412 /* 1413 * Print out various scheduling related per-task fields: 1414 */ 1415 static int sched_show(struct seq_file *m, void *v) 1416 { 1417 struct inode *inode = m->private; 1418 struct pid_namespace *ns = proc_pid_ns(inode); 1419 struct task_struct *p; 1420 1421 p = get_proc_task(inode); 1422 if (!p) 1423 return -ESRCH; 1424 proc_sched_show_task(p, ns, m); 1425 1426 put_task_struct(p); 1427 1428 return 0; 1429 } 1430 1431 static ssize_t 1432 sched_write(struct file *file, const char __user *buf, 1433 size_t count, loff_t *offset) 1434 { 1435 struct inode *inode = file_inode(file); 1436 struct task_struct *p; 1437 1438 p = get_proc_task(inode); 1439 if (!p) 1440 return -ESRCH; 1441 proc_sched_set_task(p); 1442 1443 put_task_struct(p); 1444 1445 return count; 1446 } 1447 1448 static int sched_open(struct inode *inode, struct file *filp) 1449 { 1450 return single_open(filp, sched_show, inode); 1451 } 1452 1453 static const struct file_operations proc_pid_sched_operations = { 1454 .open = sched_open, 1455 .read = seq_read, 1456 .write = sched_write, 1457 .llseek = seq_lseek, 1458 .release = single_release, 1459 }; 1460 1461 #endif 1462 1463 #ifdef CONFIG_SCHED_AUTOGROUP 1464 /* 1465 * Print out autogroup related information: 1466 */ 1467 static int sched_autogroup_show(struct seq_file *m, void *v) 1468 { 1469 struct inode *inode = m->private; 1470 struct task_struct *p; 1471 1472 p = get_proc_task(inode); 1473 if (!p) 1474 return -ESRCH; 1475 proc_sched_autogroup_show_task(p, m); 1476 1477 put_task_struct(p); 1478 1479 return 0; 1480 } 1481 1482 static ssize_t 1483 sched_autogroup_write(struct file *file, const char __user *buf, 1484 size_t count, loff_t *offset) 1485 { 1486 struct inode *inode = file_inode(file); 1487 struct task_struct *p; 1488 char buffer[PROC_NUMBUF]; 1489 int nice; 1490 int err; 1491 1492 memset(buffer, 0, sizeof(buffer)); 1493 if (count > sizeof(buffer) - 1) 1494 count = sizeof(buffer) - 1; 1495 if (copy_from_user(buffer, buf, count)) 1496 return -EFAULT; 1497 1498 err = kstrtoint(strstrip(buffer), 0, &nice); 1499 if (err < 0) 1500 return err; 1501 1502 p = get_proc_task(inode); 1503 if (!p) 1504 return -ESRCH; 1505 1506 err = proc_sched_autogroup_set_nice(p, nice); 1507 if (err) 1508 count = err; 1509 1510 put_task_struct(p); 1511 1512 return count; 1513 } 1514 1515 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1516 { 1517 int ret; 1518 1519 ret = single_open(filp, sched_autogroup_show, NULL); 1520 if (!ret) { 1521 struct seq_file *m = filp->private_data; 1522 1523 m->private = inode; 1524 } 1525 return ret; 1526 } 1527 1528 static const struct file_operations proc_pid_sched_autogroup_operations = { 1529 .open = sched_autogroup_open, 1530 .read = seq_read, 1531 .write = sched_autogroup_write, 1532 .llseek = seq_lseek, 1533 .release = single_release, 1534 }; 1535 1536 #endif /* CONFIG_SCHED_AUTOGROUP */ 1537 1538 #ifdef CONFIG_TIME_NS 1539 static int timens_offsets_show(struct seq_file *m, void *v) 1540 { 1541 struct task_struct *p; 1542 1543 p = get_proc_task(file_inode(m->file)); 1544 if (!p) 1545 return -ESRCH; 1546 proc_timens_show_offsets(p, m); 1547 1548 put_task_struct(p); 1549 1550 return 0; 1551 } 1552 1553 static ssize_t timens_offsets_write(struct file *file, const char __user *buf, 1554 size_t count, loff_t *ppos) 1555 { 1556 struct inode *inode = file_inode(file); 1557 struct proc_timens_offset offsets[2]; 1558 char *kbuf = NULL, *pos, *next_line; 1559 struct task_struct *p; 1560 int ret, noffsets; 1561 1562 /* Only allow < page size writes at the beginning of the file */ 1563 if ((*ppos != 0) || (count >= PAGE_SIZE)) 1564 return -EINVAL; 1565 1566 /* Slurp in the user data */ 1567 kbuf = memdup_user_nul(buf, count); 1568 if (IS_ERR(kbuf)) 1569 return PTR_ERR(kbuf); 1570 1571 /* Parse the user data */ 1572 ret = -EINVAL; 1573 noffsets = 0; 1574 for (pos = kbuf; pos; pos = next_line) { 1575 struct proc_timens_offset *off = &offsets[noffsets]; 1576 int err; 1577 1578 /* Find the end of line and ensure we don't look past it */ 1579 next_line = strchr(pos, '\n'); 1580 if (next_line) { 1581 *next_line = '\0'; 1582 next_line++; 1583 if (*next_line == '\0') 1584 next_line = NULL; 1585 } 1586 1587 err = sscanf(pos, "%u %lld %lu", &off->clockid, 1588 &off->val.tv_sec, &off->val.tv_nsec); 1589 if (err != 3 || off->val.tv_nsec >= NSEC_PER_SEC) 1590 goto out; 1591 noffsets++; 1592 if (noffsets == ARRAY_SIZE(offsets)) { 1593 if (next_line) 1594 count = next_line - kbuf; 1595 break; 1596 } 1597 } 1598 1599 ret = -ESRCH; 1600 p = get_proc_task(inode); 1601 if (!p) 1602 goto out; 1603 ret = proc_timens_set_offset(file, p, offsets, noffsets); 1604 put_task_struct(p); 1605 if (ret) 1606 goto out; 1607 1608 ret = count; 1609 out: 1610 kfree(kbuf); 1611 return ret; 1612 } 1613 1614 static int timens_offsets_open(struct inode *inode, struct file *filp) 1615 { 1616 return single_open(filp, timens_offsets_show, inode); 1617 } 1618 1619 static const struct file_operations proc_timens_offsets_operations = { 1620 .open = timens_offsets_open, 1621 .read = seq_read, 1622 .write = timens_offsets_write, 1623 .llseek = seq_lseek, 1624 .release = single_release, 1625 }; 1626 #endif /* CONFIG_TIME_NS */ 1627 1628 static ssize_t comm_write(struct file *file, const char __user *buf, 1629 size_t count, loff_t *offset) 1630 { 1631 struct inode *inode = file_inode(file); 1632 struct task_struct *p; 1633 char buffer[TASK_COMM_LEN]; 1634 const size_t maxlen = sizeof(buffer) - 1; 1635 1636 memset(buffer, 0, sizeof(buffer)); 1637 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count)) 1638 return -EFAULT; 1639 1640 p = get_proc_task(inode); 1641 if (!p) 1642 return -ESRCH; 1643 1644 if (same_thread_group(current, p)) 1645 set_task_comm(p, buffer); 1646 else 1647 count = -EINVAL; 1648 1649 put_task_struct(p); 1650 1651 return count; 1652 } 1653 1654 static int comm_show(struct seq_file *m, void *v) 1655 { 1656 struct inode *inode = m->private; 1657 struct task_struct *p; 1658 1659 p = get_proc_task(inode); 1660 if (!p) 1661 return -ESRCH; 1662 1663 proc_task_name(m, p, false); 1664 seq_putc(m, '\n'); 1665 1666 put_task_struct(p); 1667 1668 return 0; 1669 } 1670 1671 static int comm_open(struct inode *inode, struct file *filp) 1672 { 1673 return single_open(filp, comm_show, inode); 1674 } 1675 1676 static const struct file_operations proc_pid_set_comm_operations = { 1677 .open = comm_open, 1678 .read = seq_read, 1679 .write = comm_write, 1680 .llseek = seq_lseek, 1681 .release = single_release, 1682 }; 1683 1684 static int proc_exe_link(struct dentry *dentry, struct path *exe_path) 1685 { 1686 struct task_struct *task; 1687 struct file *exe_file; 1688 1689 task = get_proc_task(d_inode(dentry)); 1690 if (!task) 1691 return -ENOENT; 1692 exe_file = get_task_exe_file(task); 1693 put_task_struct(task); 1694 if (exe_file) { 1695 *exe_path = exe_file->f_path; 1696 path_get(&exe_file->f_path); 1697 fput(exe_file); 1698 return 0; 1699 } else 1700 return -ENOENT; 1701 } 1702 1703 static const char *proc_pid_get_link(struct dentry *dentry, 1704 struct inode *inode, 1705 struct delayed_call *done) 1706 { 1707 struct path path; 1708 int error = -EACCES; 1709 1710 if (!dentry) 1711 return ERR_PTR(-ECHILD); 1712 1713 /* Are we allowed to snoop on the tasks file descriptors? */ 1714 if (!proc_fd_access_allowed(inode)) 1715 goto out; 1716 1717 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1718 if (error) 1719 goto out; 1720 1721 error = nd_jump_link(&path); 1722 out: 1723 return ERR_PTR(error); 1724 } 1725 1726 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1727 { 1728 char *tmp = (char *)__get_free_page(GFP_KERNEL); 1729 char *pathname; 1730 int len; 1731 1732 if (!tmp) 1733 return -ENOMEM; 1734 1735 pathname = d_path(path, tmp, PAGE_SIZE); 1736 len = PTR_ERR(pathname); 1737 if (IS_ERR(pathname)) 1738 goto out; 1739 len = tmp + PAGE_SIZE - 1 - pathname; 1740 1741 if (len > buflen) 1742 len = buflen; 1743 if (copy_to_user(buffer, pathname, len)) 1744 len = -EFAULT; 1745 out: 1746 free_page((unsigned long)tmp); 1747 return len; 1748 } 1749 1750 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1751 { 1752 int error = -EACCES; 1753 struct inode *inode = d_inode(dentry); 1754 struct path path; 1755 1756 /* Are we allowed to snoop on the tasks file descriptors? */ 1757 if (!proc_fd_access_allowed(inode)) 1758 goto out; 1759 1760 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1761 if (error) 1762 goto out; 1763 1764 error = do_proc_readlink(&path, buffer, buflen); 1765 path_put(&path); 1766 out: 1767 return error; 1768 } 1769 1770 const struct inode_operations proc_pid_link_inode_operations = { 1771 .readlink = proc_pid_readlink, 1772 .get_link = proc_pid_get_link, 1773 .setattr = proc_setattr, 1774 }; 1775 1776 1777 /* building an inode */ 1778 1779 void task_dump_owner(struct task_struct *task, umode_t mode, 1780 kuid_t *ruid, kgid_t *rgid) 1781 { 1782 /* Depending on the state of dumpable compute who should own a 1783 * proc file for a task. 1784 */ 1785 const struct cred *cred; 1786 kuid_t uid; 1787 kgid_t gid; 1788 1789 if (unlikely(task->flags & PF_KTHREAD)) { 1790 *ruid = GLOBAL_ROOT_UID; 1791 *rgid = GLOBAL_ROOT_GID; 1792 return; 1793 } 1794 1795 /* Default to the tasks effective ownership */ 1796 rcu_read_lock(); 1797 cred = __task_cred(task); 1798 uid = cred->euid; 1799 gid = cred->egid; 1800 rcu_read_unlock(); 1801 1802 /* 1803 * Before the /proc/pid/status file was created the only way to read 1804 * the effective uid of a /process was to stat /proc/pid. Reading 1805 * /proc/pid/status is slow enough that procps and other packages 1806 * kept stating /proc/pid. To keep the rules in /proc simple I have 1807 * made this apply to all per process world readable and executable 1808 * directories. 1809 */ 1810 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) { 1811 struct mm_struct *mm; 1812 task_lock(task); 1813 mm = task->mm; 1814 /* Make non-dumpable tasks owned by some root */ 1815 if (mm) { 1816 if (get_dumpable(mm) != SUID_DUMP_USER) { 1817 struct user_namespace *user_ns = mm->user_ns; 1818 1819 uid = make_kuid(user_ns, 0); 1820 if (!uid_valid(uid)) 1821 uid = GLOBAL_ROOT_UID; 1822 1823 gid = make_kgid(user_ns, 0); 1824 if (!gid_valid(gid)) 1825 gid = GLOBAL_ROOT_GID; 1826 } 1827 } else { 1828 uid = GLOBAL_ROOT_UID; 1829 gid = GLOBAL_ROOT_GID; 1830 } 1831 task_unlock(task); 1832 } 1833 *ruid = uid; 1834 *rgid = gid; 1835 } 1836 1837 struct inode *proc_pid_make_inode(struct super_block * sb, 1838 struct task_struct *task, umode_t mode) 1839 { 1840 struct inode * inode; 1841 struct proc_inode *ei; 1842 1843 /* We need a new inode */ 1844 1845 inode = new_inode(sb); 1846 if (!inode) 1847 goto out; 1848 1849 /* Common stuff */ 1850 ei = PROC_I(inode); 1851 inode->i_mode = mode; 1852 inode->i_ino = get_next_ino(); 1853 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 1854 inode->i_op = &proc_def_inode_operations; 1855 1856 /* 1857 * grab the reference to task. 1858 */ 1859 ei->pid = get_task_pid(task, PIDTYPE_PID); 1860 if (!ei->pid) 1861 goto out_unlock; 1862 1863 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); 1864 security_task_to_inode(task, inode); 1865 1866 out: 1867 return inode; 1868 1869 out_unlock: 1870 iput(inode); 1871 return NULL; 1872 } 1873 1874 int pid_getattr(const struct path *path, struct kstat *stat, 1875 u32 request_mask, unsigned int query_flags) 1876 { 1877 struct inode *inode = d_inode(path->dentry); 1878 struct pid_namespace *pid = proc_pid_ns(inode); 1879 struct task_struct *task; 1880 1881 generic_fillattr(inode, stat); 1882 1883 stat->uid = GLOBAL_ROOT_UID; 1884 stat->gid = GLOBAL_ROOT_GID; 1885 rcu_read_lock(); 1886 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1887 if (task) { 1888 if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) { 1889 rcu_read_unlock(); 1890 /* 1891 * This doesn't prevent learning whether PID exists, 1892 * it only makes getattr() consistent with readdir(). 1893 */ 1894 return -ENOENT; 1895 } 1896 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid); 1897 } 1898 rcu_read_unlock(); 1899 return 0; 1900 } 1901 1902 /* dentry stuff */ 1903 1904 /* 1905 * Set <pid>/... inode ownership (can change due to setuid(), etc.) 1906 */ 1907 void pid_update_inode(struct task_struct *task, struct inode *inode) 1908 { 1909 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid); 1910 1911 inode->i_mode &= ~(S_ISUID | S_ISGID); 1912 security_task_to_inode(task, inode); 1913 } 1914 1915 /* 1916 * Rewrite the inode's ownerships here because the owning task may have 1917 * performed a setuid(), etc. 1918 * 1919 */ 1920 static int pid_revalidate(struct dentry *dentry, unsigned int flags) 1921 { 1922 struct inode *inode; 1923 struct task_struct *task; 1924 1925 if (flags & LOOKUP_RCU) 1926 return -ECHILD; 1927 1928 inode = d_inode(dentry); 1929 task = get_proc_task(inode); 1930 1931 if (task) { 1932 pid_update_inode(task, inode); 1933 put_task_struct(task); 1934 return 1; 1935 } 1936 return 0; 1937 } 1938 1939 static inline bool proc_inode_is_dead(struct inode *inode) 1940 { 1941 return !proc_pid(inode)->tasks[PIDTYPE_PID].first; 1942 } 1943 1944 int pid_delete_dentry(const struct dentry *dentry) 1945 { 1946 /* Is the task we represent dead? 1947 * If so, then don't put the dentry on the lru list, 1948 * kill it immediately. 1949 */ 1950 return proc_inode_is_dead(d_inode(dentry)); 1951 } 1952 1953 const struct dentry_operations pid_dentry_operations = 1954 { 1955 .d_revalidate = pid_revalidate, 1956 .d_delete = pid_delete_dentry, 1957 }; 1958 1959 /* Lookups */ 1960 1961 /* 1962 * Fill a directory entry. 1963 * 1964 * If possible create the dcache entry and derive our inode number and 1965 * file type from dcache entry. 1966 * 1967 * Since all of the proc inode numbers are dynamically generated, the inode 1968 * numbers do not exist until the inode is cache. This means creating the 1969 * the dcache entry in readdir is necessary to keep the inode numbers 1970 * reported by readdir in sync with the inode numbers reported 1971 * by stat. 1972 */ 1973 bool proc_fill_cache(struct file *file, struct dir_context *ctx, 1974 const char *name, unsigned int len, 1975 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1976 { 1977 struct dentry *child, *dir = file->f_path.dentry; 1978 struct qstr qname = QSTR_INIT(name, len); 1979 struct inode *inode; 1980 unsigned type = DT_UNKNOWN; 1981 ino_t ino = 1; 1982 1983 child = d_hash_and_lookup(dir, &qname); 1984 if (!child) { 1985 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 1986 child = d_alloc_parallel(dir, &qname, &wq); 1987 if (IS_ERR(child)) 1988 goto end_instantiate; 1989 if (d_in_lookup(child)) { 1990 struct dentry *res; 1991 res = instantiate(child, task, ptr); 1992 d_lookup_done(child); 1993 if (unlikely(res)) { 1994 dput(child); 1995 child = res; 1996 if (IS_ERR(child)) 1997 goto end_instantiate; 1998 } 1999 } 2000 } 2001 inode = d_inode(child); 2002 ino = inode->i_ino; 2003 type = inode->i_mode >> 12; 2004 dput(child); 2005 end_instantiate: 2006 return dir_emit(ctx, name, len, ino, type); 2007 } 2008 2009 /* 2010 * dname_to_vma_addr - maps a dentry name into two unsigned longs 2011 * which represent vma start and end addresses. 2012 */ 2013 static int dname_to_vma_addr(struct dentry *dentry, 2014 unsigned long *start, unsigned long *end) 2015 { 2016 const char *str = dentry->d_name.name; 2017 unsigned long long sval, eval; 2018 unsigned int len; 2019 2020 if (str[0] == '0' && str[1] != '-') 2021 return -EINVAL; 2022 len = _parse_integer(str, 16, &sval); 2023 if (len & KSTRTOX_OVERFLOW) 2024 return -EINVAL; 2025 if (sval != (unsigned long)sval) 2026 return -EINVAL; 2027 str += len; 2028 2029 if (*str != '-') 2030 return -EINVAL; 2031 str++; 2032 2033 if (str[0] == '0' && str[1]) 2034 return -EINVAL; 2035 len = _parse_integer(str, 16, &eval); 2036 if (len & KSTRTOX_OVERFLOW) 2037 return -EINVAL; 2038 if (eval != (unsigned long)eval) 2039 return -EINVAL; 2040 str += len; 2041 2042 if (*str != '\0') 2043 return -EINVAL; 2044 2045 *start = sval; 2046 *end = eval; 2047 2048 return 0; 2049 } 2050 2051 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags) 2052 { 2053 unsigned long vm_start, vm_end; 2054 bool exact_vma_exists = false; 2055 struct mm_struct *mm = NULL; 2056 struct task_struct *task; 2057 struct inode *inode; 2058 int status = 0; 2059 2060 if (flags & LOOKUP_RCU) 2061 return -ECHILD; 2062 2063 inode = d_inode(dentry); 2064 task = get_proc_task(inode); 2065 if (!task) 2066 goto out_notask; 2067 2068 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); 2069 if (IS_ERR_OR_NULL(mm)) 2070 goto out; 2071 2072 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 2073 status = down_read_killable(&mm->mmap_sem); 2074 if (!status) { 2075 exact_vma_exists = !!find_exact_vma(mm, vm_start, 2076 vm_end); 2077 up_read(&mm->mmap_sem); 2078 } 2079 } 2080 2081 mmput(mm); 2082 2083 if (exact_vma_exists) { 2084 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); 2085 2086 security_task_to_inode(task, inode); 2087 status = 1; 2088 } 2089 2090 out: 2091 put_task_struct(task); 2092 2093 out_notask: 2094 return status; 2095 } 2096 2097 static const struct dentry_operations tid_map_files_dentry_operations = { 2098 .d_revalidate = map_files_d_revalidate, 2099 .d_delete = pid_delete_dentry, 2100 }; 2101 2102 static int map_files_get_link(struct dentry *dentry, struct path *path) 2103 { 2104 unsigned long vm_start, vm_end; 2105 struct vm_area_struct *vma; 2106 struct task_struct *task; 2107 struct mm_struct *mm; 2108 int rc; 2109 2110 rc = -ENOENT; 2111 task = get_proc_task(d_inode(dentry)); 2112 if (!task) 2113 goto out; 2114 2115 mm = get_task_mm(task); 2116 put_task_struct(task); 2117 if (!mm) 2118 goto out; 2119 2120 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 2121 if (rc) 2122 goto out_mmput; 2123 2124 rc = down_read_killable(&mm->mmap_sem); 2125 if (rc) 2126 goto out_mmput; 2127 2128 rc = -ENOENT; 2129 vma = find_exact_vma(mm, vm_start, vm_end); 2130 if (vma && vma->vm_file) { 2131 *path = vma->vm_file->f_path; 2132 path_get(path); 2133 rc = 0; 2134 } 2135 up_read(&mm->mmap_sem); 2136 2137 out_mmput: 2138 mmput(mm); 2139 out: 2140 return rc; 2141 } 2142 2143 struct map_files_info { 2144 unsigned long start; 2145 unsigned long end; 2146 fmode_t mode; 2147 }; 2148 2149 /* 2150 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the 2151 * symlinks may be used to bypass permissions on ancestor directories in the 2152 * path to the file in question. 2153 */ 2154 static const char * 2155 proc_map_files_get_link(struct dentry *dentry, 2156 struct inode *inode, 2157 struct delayed_call *done) 2158 { 2159 if (!capable(CAP_SYS_ADMIN)) 2160 return ERR_PTR(-EPERM); 2161 2162 return proc_pid_get_link(dentry, inode, done); 2163 } 2164 2165 /* 2166 * Identical to proc_pid_link_inode_operations except for get_link() 2167 */ 2168 static const struct inode_operations proc_map_files_link_inode_operations = { 2169 .readlink = proc_pid_readlink, 2170 .get_link = proc_map_files_get_link, 2171 .setattr = proc_setattr, 2172 }; 2173 2174 static struct dentry * 2175 proc_map_files_instantiate(struct dentry *dentry, 2176 struct task_struct *task, const void *ptr) 2177 { 2178 fmode_t mode = (fmode_t)(unsigned long)ptr; 2179 struct proc_inode *ei; 2180 struct inode *inode; 2181 2182 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK | 2183 ((mode & FMODE_READ ) ? S_IRUSR : 0) | 2184 ((mode & FMODE_WRITE) ? S_IWUSR : 0)); 2185 if (!inode) 2186 return ERR_PTR(-ENOENT); 2187 2188 ei = PROC_I(inode); 2189 ei->op.proc_get_link = map_files_get_link; 2190 2191 inode->i_op = &proc_map_files_link_inode_operations; 2192 inode->i_size = 64; 2193 2194 d_set_d_op(dentry, &tid_map_files_dentry_operations); 2195 return d_splice_alias(inode, dentry); 2196 } 2197 2198 static struct dentry *proc_map_files_lookup(struct inode *dir, 2199 struct dentry *dentry, unsigned int flags) 2200 { 2201 unsigned long vm_start, vm_end; 2202 struct vm_area_struct *vma; 2203 struct task_struct *task; 2204 struct dentry *result; 2205 struct mm_struct *mm; 2206 2207 result = ERR_PTR(-ENOENT); 2208 task = get_proc_task(dir); 2209 if (!task) 2210 goto out; 2211 2212 result = ERR_PTR(-EACCES); 2213 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2214 goto out_put_task; 2215 2216 result = ERR_PTR(-ENOENT); 2217 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 2218 goto out_put_task; 2219 2220 mm = get_task_mm(task); 2221 if (!mm) 2222 goto out_put_task; 2223 2224 result = ERR_PTR(-EINTR); 2225 if (down_read_killable(&mm->mmap_sem)) 2226 goto out_put_mm; 2227 2228 result = ERR_PTR(-ENOENT); 2229 vma = find_exact_vma(mm, vm_start, vm_end); 2230 if (!vma) 2231 goto out_no_vma; 2232 2233 if (vma->vm_file) 2234 result = proc_map_files_instantiate(dentry, task, 2235 (void *)(unsigned long)vma->vm_file->f_mode); 2236 2237 out_no_vma: 2238 up_read(&mm->mmap_sem); 2239 out_put_mm: 2240 mmput(mm); 2241 out_put_task: 2242 put_task_struct(task); 2243 out: 2244 return result; 2245 } 2246 2247 static const struct inode_operations proc_map_files_inode_operations = { 2248 .lookup = proc_map_files_lookup, 2249 .permission = proc_fd_permission, 2250 .setattr = proc_setattr, 2251 }; 2252 2253 static int 2254 proc_map_files_readdir(struct file *file, struct dir_context *ctx) 2255 { 2256 struct vm_area_struct *vma; 2257 struct task_struct *task; 2258 struct mm_struct *mm; 2259 unsigned long nr_files, pos, i; 2260 GENRADIX(struct map_files_info) fa; 2261 struct map_files_info *p; 2262 int ret; 2263 2264 genradix_init(&fa); 2265 2266 ret = -ENOENT; 2267 task = get_proc_task(file_inode(file)); 2268 if (!task) 2269 goto out; 2270 2271 ret = -EACCES; 2272 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2273 goto out_put_task; 2274 2275 ret = 0; 2276 if (!dir_emit_dots(file, ctx)) 2277 goto out_put_task; 2278 2279 mm = get_task_mm(task); 2280 if (!mm) 2281 goto out_put_task; 2282 2283 ret = down_read_killable(&mm->mmap_sem); 2284 if (ret) { 2285 mmput(mm); 2286 goto out_put_task; 2287 } 2288 2289 nr_files = 0; 2290 2291 /* 2292 * We need two passes here: 2293 * 2294 * 1) Collect vmas of mapped files with mmap_sem taken 2295 * 2) Release mmap_sem and instantiate entries 2296 * 2297 * otherwise we get lockdep complained, since filldir() 2298 * routine might require mmap_sem taken in might_fault(). 2299 */ 2300 2301 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 2302 if (!vma->vm_file) 2303 continue; 2304 if (++pos <= ctx->pos) 2305 continue; 2306 2307 p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL); 2308 if (!p) { 2309 ret = -ENOMEM; 2310 up_read(&mm->mmap_sem); 2311 mmput(mm); 2312 goto out_put_task; 2313 } 2314 2315 p->start = vma->vm_start; 2316 p->end = vma->vm_end; 2317 p->mode = vma->vm_file->f_mode; 2318 } 2319 up_read(&mm->mmap_sem); 2320 mmput(mm); 2321 2322 for (i = 0; i < nr_files; i++) { 2323 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */ 2324 unsigned int len; 2325 2326 p = genradix_ptr(&fa, i); 2327 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end); 2328 if (!proc_fill_cache(file, ctx, 2329 buf, len, 2330 proc_map_files_instantiate, 2331 task, 2332 (void *)(unsigned long)p->mode)) 2333 break; 2334 ctx->pos++; 2335 } 2336 2337 out_put_task: 2338 put_task_struct(task); 2339 out: 2340 genradix_free(&fa); 2341 return ret; 2342 } 2343 2344 static const struct file_operations proc_map_files_operations = { 2345 .read = generic_read_dir, 2346 .iterate_shared = proc_map_files_readdir, 2347 .llseek = generic_file_llseek, 2348 }; 2349 2350 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS) 2351 struct timers_private { 2352 struct pid *pid; 2353 struct task_struct *task; 2354 struct sighand_struct *sighand; 2355 struct pid_namespace *ns; 2356 unsigned long flags; 2357 }; 2358 2359 static void *timers_start(struct seq_file *m, loff_t *pos) 2360 { 2361 struct timers_private *tp = m->private; 2362 2363 tp->task = get_pid_task(tp->pid, PIDTYPE_PID); 2364 if (!tp->task) 2365 return ERR_PTR(-ESRCH); 2366 2367 tp->sighand = lock_task_sighand(tp->task, &tp->flags); 2368 if (!tp->sighand) 2369 return ERR_PTR(-ESRCH); 2370 2371 return seq_list_start(&tp->task->signal->posix_timers, *pos); 2372 } 2373 2374 static void *timers_next(struct seq_file *m, void *v, loff_t *pos) 2375 { 2376 struct timers_private *tp = m->private; 2377 return seq_list_next(v, &tp->task->signal->posix_timers, pos); 2378 } 2379 2380 static void timers_stop(struct seq_file *m, void *v) 2381 { 2382 struct timers_private *tp = m->private; 2383 2384 if (tp->sighand) { 2385 unlock_task_sighand(tp->task, &tp->flags); 2386 tp->sighand = NULL; 2387 } 2388 2389 if (tp->task) { 2390 put_task_struct(tp->task); 2391 tp->task = NULL; 2392 } 2393 } 2394 2395 static int show_timer(struct seq_file *m, void *v) 2396 { 2397 struct k_itimer *timer; 2398 struct timers_private *tp = m->private; 2399 int notify; 2400 static const char * const nstr[] = { 2401 [SIGEV_SIGNAL] = "signal", 2402 [SIGEV_NONE] = "none", 2403 [SIGEV_THREAD] = "thread", 2404 }; 2405 2406 timer = list_entry((struct list_head *)v, struct k_itimer, list); 2407 notify = timer->it_sigev_notify; 2408 2409 seq_printf(m, "ID: %d\n", timer->it_id); 2410 seq_printf(m, "signal: %d/%px\n", 2411 timer->sigq->info.si_signo, 2412 timer->sigq->info.si_value.sival_ptr); 2413 seq_printf(m, "notify: %s/%s.%d\n", 2414 nstr[notify & ~SIGEV_THREAD_ID], 2415 (notify & SIGEV_THREAD_ID) ? "tid" : "pid", 2416 pid_nr_ns(timer->it_pid, tp->ns)); 2417 seq_printf(m, "ClockID: %d\n", timer->it_clock); 2418 2419 return 0; 2420 } 2421 2422 static const struct seq_operations proc_timers_seq_ops = { 2423 .start = timers_start, 2424 .next = timers_next, 2425 .stop = timers_stop, 2426 .show = show_timer, 2427 }; 2428 2429 static int proc_timers_open(struct inode *inode, struct file *file) 2430 { 2431 struct timers_private *tp; 2432 2433 tp = __seq_open_private(file, &proc_timers_seq_ops, 2434 sizeof(struct timers_private)); 2435 if (!tp) 2436 return -ENOMEM; 2437 2438 tp->pid = proc_pid(inode); 2439 tp->ns = proc_pid_ns(inode); 2440 return 0; 2441 } 2442 2443 static const struct file_operations proc_timers_operations = { 2444 .open = proc_timers_open, 2445 .read = seq_read, 2446 .llseek = seq_lseek, 2447 .release = seq_release_private, 2448 }; 2449 #endif 2450 2451 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf, 2452 size_t count, loff_t *offset) 2453 { 2454 struct inode *inode = file_inode(file); 2455 struct task_struct *p; 2456 u64 slack_ns; 2457 int err; 2458 2459 err = kstrtoull_from_user(buf, count, 10, &slack_ns); 2460 if (err < 0) 2461 return err; 2462 2463 p = get_proc_task(inode); 2464 if (!p) 2465 return -ESRCH; 2466 2467 if (p != current) { 2468 rcu_read_lock(); 2469 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { 2470 rcu_read_unlock(); 2471 count = -EPERM; 2472 goto out; 2473 } 2474 rcu_read_unlock(); 2475 2476 err = security_task_setscheduler(p); 2477 if (err) { 2478 count = err; 2479 goto out; 2480 } 2481 } 2482 2483 task_lock(p); 2484 if (slack_ns == 0) 2485 p->timer_slack_ns = p->default_timer_slack_ns; 2486 else 2487 p->timer_slack_ns = slack_ns; 2488 task_unlock(p); 2489 2490 out: 2491 put_task_struct(p); 2492 2493 return count; 2494 } 2495 2496 static int timerslack_ns_show(struct seq_file *m, void *v) 2497 { 2498 struct inode *inode = m->private; 2499 struct task_struct *p; 2500 int err = 0; 2501 2502 p = get_proc_task(inode); 2503 if (!p) 2504 return -ESRCH; 2505 2506 if (p != current) { 2507 rcu_read_lock(); 2508 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { 2509 rcu_read_unlock(); 2510 err = -EPERM; 2511 goto out; 2512 } 2513 rcu_read_unlock(); 2514 2515 err = security_task_getscheduler(p); 2516 if (err) 2517 goto out; 2518 } 2519 2520 task_lock(p); 2521 seq_printf(m, "%llu\n", p->timer_slack_ns); 2522 task_unlock(p); 2523 2524 out: 2525 put_task_struct(p); 2526 2527 return err; 2528 } 2529 2530 static int timerslack_ns_open(struct inode *inode, struct file *filp) 2531 { 2532 return single_open(filp, timerslack_ns_show, inode); 2533 } 2534 2535 static const struct file_operations proc_pid_set_timerslack_ns_operations = { 2536 .open = timerslack_ns_open, 2537 .read = seq_read, 2538 .write = timerslack_ns_write, 2539 .llseek = seq_lseek, 2540 .release = single_release, 2541 }; 2542 2543 static struct dentry *proc_pident_instantiate(struct dentry *dentry, 2544 struct task_struct *task, const void *ptr) 2545 { 2546 const struct pid_entry *p = ptr; 2547 struct inode *inode; 2548 struct proc_inode *ei; 2549 2550 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode); 2551 if (!inode) 2552 return ERR_PTR(-ENOENT); 2553 2554 ei = PROC_I(inode); 2555 if (S_ISDIR(inode->i_mode)) 2556 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2557 if (p->iop) 2558 inode->i_op = p->iop; 2559 if (p->fop) 2560 inode->i_fop = p->fop; 2561 ei->op = p->op; 2562 pid_update_inode(task, inode); 2563 d_set_d_op(dentry, &pid_dentry_operations); 2564 return d_splice_alias(inode, dentry); 2565 } 2566 2567 static struct dentry *proc_pident_lookup(struct inode *dir, 2568 struct dentry *dentry, 2569 const struct pid_entry *p, 2570 const struct pid_entry *end) 2571 { 2572 struct task_struct *task = get_proc_task(dir); 2573 struct dentry *res = ERR_PTR(-ENOENT); 2574 2575 if (!task) 2576 goto out_no_task; 2577 2578 /* 2579 * Yes, it does not scale. And it should not. Don't add 2580 * new entries into /proc/<tgid>/ without very good reasons. 2581 */ 2582 for (; p < end; p++) { 2583 if (p->len != dentry->d_name.len) 2584 continue; 2585 if (!memcmp(dentry->d_name.name, p->name, p->len)) { 2586 res = proc_pident_instantiate(dentry, task, p); 2587 break; 2588 } 2589 } 2590 put_task_struct(task); 2591 out_no_task: 2592 return res; 2593 } 2594 2595 static int proc_pident_readdir(struct file *file, struct dir_context *ctx, 2596 const struct pid_entry *ents, unsigned int nents) 2597 { 2598 struct task_struct *task = get_proc_task(file_inode(file)); 2599 const struct pid_entry *p; 2600 2601 if (!task) 2602 return -ENOENT; 2603 2604 if (!dir_emit_dots(file, ctx)) 2605 goto out; 2606 2607 if (ctx->pos >= nents + 2) 2608 goto out; 2609 2610 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) { 2611 if (!proc_fill_cache(file, ctx, p->name, p->len, 2612 proc_pident_instantiate, task, p)) 2613 break; 2614 ctx->pos++; 2615 } 2616 out: 2617 put_task_struct(task); 2618 return 0; 2619 } 2620 2621 #ifdef CONFIG_SECURITY 2622 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2623 size_t count, loff_t *ppos) 2624 { 2625 struct inode * inode = file_inode(file); 2626 char *p = NULL; 2627 ssize_t length; 2628 struct task_struct *task = get_proc_task(inode); 2629 2630 if (!task) 2631 return -ESRCH; 2632 2633 length = security_getprocattr(task, PROC_I(inode)->op.lsm, 2634 (char*)file->f_path.dentry->d_name.name, 2635 &p); 2636 put_task_struct(task); 2637 if (length > 0) 2638 length = simple_read_from_buffer(buf, count, ppos, p, length); 2639 kfree(p); 2640 return length; 2641 } 2642 2643 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2644 size_t count, loff_t *ppos) 2645 { 2646 struct inode * inode = file_inode(file); 2647 struct task_struct *task; 2648 void *page; 2649 int rv; 2650 2651 rcu_read_lock(); 2652 task = pid_task(proc_pid(inode), PIDTYPE_PID); 2653 if (!task) { 2654 rcu_read_unlock(); 2655 return -ESRCH; 2656 } 2657 /* A task may only write its own attributes. */ 2658 if (current != task) { 2659 rcu_read_unlock(); 2660 return -EACCES; 2661 } 2662 /* Prevent changes to overridden credentials. */ 2663 if (current_cred() != current_real_cred()) { 2664 rcu_read_unlock(); 2665 return -EBUSY; 2666 } 2667 rcu_read_unlock(); 2668 2669 if (count > PAGE_SIZE) 2670 count = PAGE_SIZE; 2671 2672 /* No partial writes. */ 2673 if (*ppos != 0) 2674 return -EINVAL; 2675 2676 page = memdup_user(buf, count); 2677 if (IS_ERR(page)) { 2678 rv = PTR_ERR(page); 2679 goto out; 2680 } 2681 2682 /* Guard against adverse ptrace interaction */ 2683 rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex); 2684 if (rv < 0) 2685 goto out_free; 2686 2687 rv = security_setprocattr(PROC_I(inode)->op.lsm, 2688 file->f_path.dentry->d_name.name, page, 2689 count); 2690 mutex_unlock(¤t->signal->cred_guard_mutex); 2691 out_free: 2692 kfree(page); 2693 out: 2694 return rv; 2695 } 2696 2697 static const struct file_operations proc_pid_attr_operations = { 2698 .read = proc_pid_attr_read, 2699 .write = proc_pid_attr_write, 2700 .llseek = generic_file_llseek, 2701 }; 2702 2703 #define LSM_DIR_OPS(LSM) \ 2704 static int proc_##LSM##_attr_dir_iterate(struct file *filp, \ 2705 struct dir_context *ctx) \ 2706 { \ 2707 return proc_pident_readdir(filp, ctx, \ 2708 LSM##_attr_dir_stuff, \ 2709 ARRAY_SIZE(LSM##_attr_dir_stuff)); \ 2710 } \ 2711 \ 2712 static const struct file_operations proc_##LSM##_attr_dir_ops = { \ 2713 .read = generic_read_dir, \ 2714 .iterate = proc_##LSM##_attr_dir_iterate, \ 2715 .llseek = default_llseek, \ 2716 }; \ 2717 \ 2718 static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \ 2719 struct dentry *dentry, unsigned int flags) \ 2720 { \ 2721 return proc_pident_lookup(dir, dentry, \ 2722 LSM##_attr_dir_stuff, \ 2723 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \ 2724 } \ 2725 \ 2726 static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \ 2727 .lookup = proc_##LSM##_attr_dir_lookup, \ 2728 .getattr = pid_getattr, \ 2729 .setattr = proc_setattr, \ 2730 } 2731 2732 #ifdef CONFIG_SECURITY_SMACK 2733 static const struct pid_entry smack_attr_dir_stuff[] = { 2734 ATTR("smack", "current", 0666), 2735 }; 2736 LSM_DIR_OPS(smack); 2737 #endif 2738 2739 static const struct pid_entry attr_dir_stuff[] = { 2740 ATTR(NULL, "current", 0666), 2741 ATTR(NULL, "prev", 0444), 2742 ATTR(NULL, "exec", 0666), 2743 ATTR(NULL, "fscreate", 0666), 2744 ATTR(NULL, "keycreate", 0666), 2745 ATTR(NULL, "sockcreate", 0666), 2746 #ifdef CONFIG_SECURITY_SMACK 2747 DIR("smack", 0555, 2748 proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops), 2749 #endif 2750 }; 2751 2752 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx) 2753 { 2754 return proc_pident_readdir(file, ctx, 2755 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2756 } 2757 2758 static const struct file_operations proc_attr_dir_operations = { 2759 .read = generic_read_dir, 2760 .iterate_shared = proc_attr_dir_readdir, 2761 .llseek = generic_file_llseek, 2762 }; 2763 2764 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2765 struct dentry *dentry, unsigned int flags) 2766 { 2767 return proc_pident_lookup(dir, dentry, 2768 attr_dir_stuff, 2769 attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff)); 2770 } 2771 2772 static const struct inode_operations proc_attr_dir_inode_operations = { 2773 .lookup = proc_attr_dir_lookup, 2774 .getattr = pid_getattr, 2775 .setattr = proc_setattr, 2776 }; 2777 2778 #endif 2779 2780 #ifdef CONFIG_ELF_CORE 2781 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2782 size_t count, loff_t *ppos) 2783 { 2784 struct task_struct *task = get_proc_task(file_inode(file)); 2785 struct mm_struct *mm; 2786 char buffer[PROC_NUMBUF]; 2787 size_t len; 2788 int ret; 2789 2790 if (!task) 2791 return -ESRCH; 2792 2793 ret = 0; 2794 mm = get_task_mm(task); 2795 if (mm) { 2796 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2797 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2798 MMF_DUMP_FILTER_SHIFT)); 2799 mmput(mm); 2800 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2801 } 2802 2803 put_task_struct(task); 2804 2805 return ret; 2806 } 2807 2808 static ssize_t proc_coredump_filter_write(struct file *file, 2809 const char __user *buf, 2810 size_t count, 2811 loff_t *ppos) 2812 { 2813 struct task_struct *task; 2814 struct mm_struct *mm; 2815 unsigned int val; 2816 int ret; 2817 int i; 2818 unsigned long mask; 2819 2820 ret = kstrtouint_from_user(buf, count, 0, &val); 2821 if (ret < 0) 2822 return ret; 2823 2824 ret = -ESRCH; 2825 task = get_proc_task(file_inode(file)); 2826 if (!task) 2827 goto out_no_task; 2828 2829 mm = get_task_mm(task); 2830 if (!mm) 2831 goto out_no_mm; 2832 ret = 0; 2833 2834 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2835 if (val & mask) 2836 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2837 else 2838 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2839 } 2840 2841 mmput(mm); 2842 out_no_mm: 2843 put_task_struct(task); 2844 out_no_task: 2845 if (ret < 0) 2846 return ret; 2847 return count; 2848 } 2849 2850 static const struct file_operations proc_coredump_filter_operations = { 2851 .read = proc_coredump_filter_read, 2852 .write = proc_coredump_filter_write, 2853 .llseek = generic_file_llseek, 2854 }; 2855 #endif 2856 2857 #ifdef CONFIG_TASK_IO_ACCOUNTING 2858 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole) 2859 { 2860 struct task_io_accounting acct = task->ioac; 2861 unsigned long flags; 2862 int result; 2863 2864 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2865 if (result) 2866 return result; 2867 2868 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { 2869 result = -EACCES; 2870 goto out_unlock; 2871 } 2872 2873 if (whole && lock_task_sighand(task, &flags)) { 2874 struct task_struct *t = task; 2875 2876 task_io_accounting_add(&acct, &task->signal->ioac); 2877 while_each_thread(task, t) 2878 task_io_accounting_add(&acct, &t->ioac); 2879 2880 unlock_task_sighand(task, &flags); 2881 } 2882 seq_printf(m, 2883 "rchar: %llu\n" 2884 "wchar: %llu\n" 2885 "syscr: %llu\n" 2886 "syscw: %llu\n" 2887 "read_bytes: %llu\n" 2888 "write_bytes: %llu\n" 2889 "cancelled_write_bytes: %llu\n", 2890 (unsigned long long)acct.rchar, 2891 (unsigned long long)acct.wchar, 2892 (unsigned long long)acct.syscr, 2893 (unsigned long long)acct.syscw, 2894 (unsigned long long)acct.read_bytes, 2895 (unsigned long long)acct.write_bytes, 2896 (unsigned long long)acct.cancelled_write_bytes); 2897 result = 0; 2898 2899 out_unlock: 2900 mutex_unlock(&task->signal->cred_guard_mutex); 2901 return result; 2902 } 2903 2904 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2905 struct pid *pid, struct task_struct *task) 2906 { 2907 return do_io_accounting(task, m, 0); 2908 } 2909 2910 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2911 struct pid *pid, struct task_struct *task) 2912 { 2913 return do_io_accounting(task, m, 1); 2914 } 2915 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2916 2917 #ifdef CONFIG_USER_NS 2918 static int proc_id_map_open(struct inode *inode, struct file *file, 2919 const struct seq_operations *seq_ops) 2920 { 2921 struct user_namespace *ns = NULL; 2922 struct task_struct *task; 2923 struct seq_file *seq; 2924 int ret = -EINVAL; 2925 2926 task = get_proc_task(inode); 2927 if (task) { 2928 rcu_read_lock(); 2929 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2930 rcu_read_unlock(); 2931 put_task_struct(task); 2932 } 2933 if (!ns) 2934 goto err; 2935 2936 ret = seq_open(file, seq_ops); 2937 if (ret) 2938 goto err_put_ns; 2939 2940 seq = file->private_data; 2941 seq->private = ns; 2942 2943 return 0; 2944 err_put_ns: 2945 put_user_ns(ns); 2946 err: 2947 return ret; 2948 } 2949 2950 static int proc_id_map_release(struct inode *inode, struct file *file) 2951 { 2952 struct seq_file *seq = file->private_data; 2953 struct user_namespace *ns = seq->private; 2954 put_user_ns(ns); 2955 return seq_release(inode, file); 2956 } 2957 2958 static int proc_uid_map_open(struct inode *inode, struct file *file) 2959 { 2960 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2961 } 2962 2963 static int proc_gid_map_open(struct inode *inode, struct file *file) 2964 { 2965 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2966 } 2967 2968 static int proc_projid_map_open(struct inode *inode, struct file *file) 2969 { 2970 return proc_id_map_open(inode, file, &proc_projid_seq_operations); 2971 } 2972 2973 static const struct file_operations proc_uid_map_operations = { 2974 .open = proc_uid_map_open, 2975 .write = proc_uid_map_write, 2976 .read = seq_read, 2977 .llseek = seq_lseek, 2978 .release = proc_id_map_release, 2979 }; 2980 2981 static const struct file_operations proc_gid_map_operations = { 2982 .open = proc_gid_map_open, 2983 .write = proc_gid_map_write, 2984 .read = seq_read, 2985 .llseek = seq_lseek, 2986 .release = proc_id_map_release, 2987 }; 2988 2989 static const struct file_operations proc_projid_map_operations = { 2990 .open = proc_projid_map_open, 2991 .write = proc_projid_map_write, 2992 .read = seq_read, 2993 .llseek = seq_lseek, 2994 .release = proc_id_map_release, 2995 }; 2996 2997 static int proc_setgroups_open(struct inode *inode, struct file *file) 2998 { 2999 struct user_namespace *ns = NULL; 3000 struct task_struct *task; 3001 int ret; 3002 3003 ret = -ESRCH; 3004 task = get_proc_task(inode); 3005 if (task) { 3006 rcu_read_lock(); 3007 ns = get_user_ns(task_cred_xxx(task, user_ns)); 3008 rcu_read_unlock(); 3009 put_task_struct(task); 3010 } 3011 if (!ns) 3012 goto err; 3013 3014 if (file->f_mode & FMODE_WRITE) { 3015 ret = -EACCES; 3016 if (!ns_capable(ns, CAP_SYS_ADMIN)) 3017 goto err_put_ns; 3018 } 3019 3020 ret = single_open(file, &proc_setgroups_show, ns); 3021 if (ret) 3022 goto err_put_ns; 3023 3024 return 0; 3025 err_put_ns: 3026 put_user_ns(ns); 3027 err: 3028 return ret; 3029 } 3030 3031 static int proc_setgroups_release(struct inode *inode, struct file *file) 3032 { 3033 struct seq_file *seq = file->private_data; 3034 struct user_namespace *ns = seq->private; 3035 int ret = single_release(inode, file); 3036 put_user_ns(ns); 3037 return ret; 3038 } 3039 3040 static const struct file_operations proc_setgroups_operations = { 3041 .open = proc_setgroups_open, 3042 .write = proc_setgroups_write, 3043 .read = seq_read, 3044 .llseek = seq_lseek, 3045 .release = proc_setgroups_release, 3046 }; 3047 #endif /* CONFIG_USER_NS */ 3048 3049 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 3050 struct pid *pid, struct task_struct *task) 3051 { 3052 int err = lock_trace(task); 3053 if (!err) { 3054 seq_printf(m, "%08x\n", task->personality); 3055 unlock_trace(task); 3056 } 3057 return err; 3058 } 3059 3060 #ifdef CONFIG_LIVEPATCH 3061 static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns, 3062 struct pid *pid, struct task_struct *task) 3063 { 3064 seq_printf(m, "%d\n", task->patch_state); 3065 return 0; 3066 } 3067 #endif /* CONFIG_LIVEPATCH */ 3068 3069 #ifdef CONFIG_STACKLEAK_METRICS 3070 static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns, 3071 struct pid *pid, struct task_struct *task) 3072 { 3073 unsigned long prev_depth = THREAD_SIZE - 3074 (task->prev_lowest_stack & (THREAD_SIZE - 1)); 3075 unsigned long depth = THREAD_SIZE - 3076 (task->lowest_stack & (THREAD_SIZE - 1)); 3077 3078 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n", 3079 prev_depth, depth); 3080 return 0; 3081 } 3082 #endif /* CONFIG_STACKLEAK_METRICS */ 3083 3084 /* 3085 * Thread groups 3086 */ 3087 static const struct file_operations proc_task_operations; 3088 static const struct inode_operations proc_task_inode_operations; 3089 3090 static const struct pid_entry tgid_base_stuff[] = { 3091 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 3092 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3093 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 3094 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3095 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3096 #ifdef CONFIG_NET 3097 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3098 #endif 3099 REG("environ", S_IRUSR, proc_environ_operations), 3100 REG("auxv", S_IRUSR, proc_auxv_operations), 3101 ONE("status", S_IRUGO, proc_pid_status), 3102 ONE("personality", S_IRUSR, proc_pid_personality), 3103 ONE("limits", S_IRUGO, proc_pid_limits), 3104 #ifdef CONFIG_SCHED_DEBUG 3105 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3106 #endif 3107 #ifdef CONFIG_SCHED_AUTOGROUP 3108 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 3109 #endif 3110 #ifdef CONFIG_TIME_NS 3111 REG("timens_offsets", S_IRUGO|S_IWUSR, proc_timens_offsets_operations), 3112 #endif 3113 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3114 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3115 ONE("syscall", S_IRUSR, proc_pid_syscall), 3116 #endif 3117 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 3118 ONE("stat", S_IRUGO, proc_tgid_stat), 3119 ONE("statm", S_IRUGO, proc_pid_statm), 3120 REG("maps", S_IRUGO, proc_pid_maps_operations), 3121 #ifdef CONFIG_NUMA 3122 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 3123 #endif 3124 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3125 LNK("cwd", proc_cwd_link), 3126 LNK("root", proc_root_link), 3127 LNK("exe", proc_exe_link), 3128 REG("mounts", S_IRUGO, proc_mounts_operations), 3129 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3130 REG("mountstats", S_IRUSR, proc_mountstats_operations), 3131 #ifdef CONFIG_PROC_PAGE_MONITOR 3132 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3133 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 3134 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations), 3135 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3136 #endif 3137 #ifdef CONFIG_SECURITY 3138 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3139 #endif 3140 #ifdef CONFIG_KALLSYMS 3141 ONE("wchan", S_IRUGO, proc_pid_wchan), 3142 #endif 3143 #ifdef CONFIG_STACKTRACE 3144 ONE("stack", S_IRUSR, proc_pid_stack), 3145 #endif 3146 #ifdef CONFIG_SCHED_INFO 3147 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 3148 #endif 3149 #ifdef CONFIG_LATENCYTOP 3150 REG("latency", S_IRUGO, proc_lstats_operations), 3151 #endif 3152 #ifdef CONFIG_PROC_PID_CPUSET 3153 ONE("cpuset", S_IRUGO, proc_cpuset_show), 3154 #endif 3155 #ifdef CONFIG_CGROUPS 3156 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3157 #endif 3158 #ifdef CONFIG_PROC_CPU_RESCTRL 3159 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show), 3160 #endif 3161 ONE("oom_score", S_IRUGO, proc_oom_score), 3162 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3163 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3164 #ifdef CONFIG_AUDIT 3165 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3166 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3167 #endif 3168 #ifdef CONFIG_FAULT_INJECTION 3169 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3170 REG("fail-nth", 0644, proc_fail_nth_operations), 3171 #endif 3172 #ifdef CONFIG_ELF_CORE 3173 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 3174 #endif 3175 #ifdef CONFIG_TASK_IO_ACCOUNTING 3176 ONE("io", S_IRUSR, proc_tgid_io_accounting), 3177 #endif 3178 #ifdef CONFIG_USER_NS 3179 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3180 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3181 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3182 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3183 #endif 3184 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS) 3185 REG("timers", S_IRUGO, proc_timers_operations), 3186 #endif 3187 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations), 3188 #ifdef CONFIG_LIVEPATCH 3189 ONE("patch_state", S_IRUSR, proc_pid_patch_state), 3190 #endif 3191 #ifdef CONFIG_STACKLEAK_METRICS 3192 ONE("stack_depth", S_IRUGO, proc_stack_depth), 3193 #endif 3194 #ifdef CONFIG_PROC_PID_ARCH_STATUS 3195 ONE("arch_status", S_IRUGO, proc_pid_arch_status), 3196 #endif 3197 }; 3198 3199 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) 3200 { 3201 return proc_pident_readdir(file, ctx, 3202 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3203 } 3204 3205 static const struct file_operations proc_tgid_base_operations = { 3206 .read = generic_read_dir, 3207 .iterate_shared = proc_tgid_base_readdir, 3208 .llseek = generic_file_llseek, 3209 }; 3210 3211 struct pid *tgid_pidfd_to_pid(const struct file *file) 3212 { 3213 if (file->f_op != &proc_tgid_base_operations) 3214 return ERR_PTR(-EBADF); 3215 3216 return proc_pid(file_inode(file)); 3217 } 3218 3219 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3220 { 3221 return proc_pident_lookup(dir, dentry, 3222 tgid_base_stuff, 3223 tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff)); 3224 } 3225 3226 static const struct inode_operations proc_tgid_base_inode_operations = { 3227 .lookup = proc_tgid_base_lookup, 3228 .getattr = pid_getattr, 3229 .setattr = proc_setattr, 3230 .permission = proc_pid_permission, 3231 }; 3232 3233 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 3234 { 3235 struct dentry *dentry, *leader, *dir; 3236 char buf[10 + 1]; 3237 struct qstr name; 3238 3239 name.name = buf; 3240 name.len = snprintf(buf, sizeof(buf), "%u", pid); 3241 /* no ->d_hash() rejects on procfs */ 3242 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 3243 if (dentry) { 3244 d_invalidate(dentry); 3245 dput(dentry); 3246 } 3247 3248 if (pid == tgid) 3249 return; 3250 3251 name.name = buf; 3252 name.len = snprintf(buf, sizeof(buf), "%u", tgid); 3253 leader = d_hash_and_lookup(mnt->mnt_root, &name); 3254 if (!leader) 3255 goto out; 3256 3257 name.name = "task"; 3258 name.len = strlen(name.name); 3259 dir = d_hash_and_lookup(leader, &name); 3260 if (!dir) 3261 goto out_put_leader; 3262 3263 name.name = buf; 3264 name.len = snprintf(buf, sizeof(buf), "%u", pid); 3265 dentry = d_hash_and_lookup(dir, &name); 3266 if (dentry) { 3267 d_invalidate(dentry); 3268 dput(dentry); 3269 } 3270 3271 dput(dir); 3272 out_put_leader: 3273 dput(leader); 3274 out: 3275 return; 3276 } 3277 3278 /** 3279 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 3280 * @task: task that should be flushed. 3281 * 3282 * When flushing dentries from proc, one needs to flush them from global 3283 * proc (proc_mnt) and from all the namespaces' procs this task was seen 3284 * in. This call is supposed to do all of this job. 3285 * 3286 * Looks in the dcache for 3287 * /proc/@pid 3288 * /proc/@tgid/task/@pid 3289 * if either directory is present flushes it and all of it'ts children 3290 * from the dcache. 3291 * 3292 * It is safe and reasonable to cache /proc entries for a task until 3293 * that task exits. After that they just clog up the dcache with 3294 * useless entries, possibly causing useful dcache entries to be 3295 * flushed instead. This routine is proved to flush those useless 3296 * dcache entries at process exit time. 3297 * 3298 * NOTE: This routine is just an optimization so it does not guarantee 3299 * that no dcache entries will exist at process exit time it 3300 * just makes it very unlikely that any will persist. 3301 */ 3302 3303 void proc_flush_task(struct task_struct *task) 3304 { 3305 int i; 3306 struct pid *pid, *tgid; 3307 struct upid *upid; 3308 3309 pid = task_pid(task); 3310 tgid = task_tgid(task); 3311 3312 for (i = 0; i <= pid->level; i++) { 3313 upid = &pid->numbers[i]; 3314 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3315 tgid->numbers[i].nr); 3316 } 3317 } 3318 3319 static struct dentry *proc_pid_instantiate(struct dentry * dentry, 3320 struct task_struct *task, const void *ptr) 3321 { 3322 struct inode *inode; 3323 3324 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3325 if (!inode) 3326 return ERR_PTR(-ENOENT); 3327 3328 inode->i_op = &proc_tgid_base_inode_operations; 3329 inode->i_fop = &proc_tgid_base_operations; 3330 inode->i_flags|=S_IMMUTABLE; 3331 3332 set_nlink(inode, nlink_tgid); 3333 pid_update_inode(task, inode); 3334 3335 d_set_d_op(dentry, &pid_dentry_operations); 3336 return d_splice_alias(inode, dentry); 3337 } 3338 3339 struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags) 3340 { 3341 struct task_struct *task; 3342 unsigned tgid; 3343 struct pid_namespace *ns; 3344 struct dentry *result = ERR_PTR(-ENOENT); 3345 3346 tgid = name_to_int(&dentry->d_name); 3347 if (tgid == ~0U) 3348 goto out; 3349 3350 ns = dentry->d_sb->s_fs_info; 3351 rcu_read_lock(); 3352 task = find_task_by_pid_ns(tgid, ns); 3353 if (task) 3354 get_task_struct(task); 3355 rcu_read_unlock(); 3356 if (!task) 3357 goto out; 3358 3359 result = proc_pid_instantiate(dentry, task, NULL); 3360 put_task_struct(task); 3361 out: 3362 return result; 3363 } 3364 3365 /* 3366 * Find the first task with tgid >= tgid 3367 * 3368 */ 3369 struct tgid_iter { 3370 unsigned int tgid; 3371 struct task_struct *task; 3372 }; 3373 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3374 { 3375 struct pid *pid; 3376 3377 if (iter.task) 3378 put_task_struct(iter.task); 3379 rcu_read_lock(); 3380 retry: 3381 iter.task = NULL; 3382 pid = find_ge_pid(iter.tgid, ns); 3383 if (pid) { 3384 iter.tgid = pid_nr_ns(pid, ns); 3385 iter.task = pid_task(pid, PIDTYPE_PID); 3386 /* What we to know is if the pid we have find is the 3387 * pid of a thread_group_leader. Testing for task 3388 * being a thread_group_leader is the obvious thing 3389 * todo but there is a window when it fails, due to 3390 * the pid transfer logic in de_thread. 3391 * 3392 * So we perform the straight forward test of seeing 3393 * if the pid we have found is the pid of a thread 3394 * group leader, and don't worry if the task we have 3395 * found doesn't happen to be a thread group leader. 3396 * As we don't care in the case of readdir. 3397 */ 3398 if (!iter.task || !has_group_leader_pid(iter.task)) { 3399 iter.tgid += 1; 3400 goto retry; 3401 } 3402 get_task_struct(iter.task); 3403 } 3404 rcu_read_unlock(); 3405 return iter; 3406 } 3407 3408 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2) 3409 3410 /* for the /proc/ directory itself, after non-process stuff has been done */ 3411 int proc_pid_readdir(struct file *file, struct dir_context *ctx) 3412 { 3413 struct tgid_iter iter; 3414 struct pid_namespace *ns = proc_pid_ns(file_inode(file)); 3415 loff_t pos = ctx->pos; 3416 3417 if (pos >= PID_MAX_LIMIT + TGID_OFFSET) 3418 return 0; 3419 3420 if (pos == TGID_OFFSET - 2) { 3421 struct inode *inode = d_inode(ns->proc_self); 3422 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) 3423 return 0; 3424 ctx->pos = pos = pos + 1; 3425 } 3426 if (pos == TGID_OFFSET - 1) { 3427 struct inode *inode = d_inode(ns->proc_thread_self); 3428 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) 3429 return 0; 3430 ctx->pos = pos = pos + 1; 3431 } 3432 iter.tgid = pos - TGID_OFFSET; 3433 iter.task = NULL; 3434 for (iter = next_tgid(ns, iter); 3435 iter.task; 3436 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3437 char name[10 + 1]; 3438 unsigned int len; 3439 3440 cond_resched(); 3441 if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE)) 3442 continue; 3443 3444 len = snprintf(name, sizeof(name), "%u", iter.tgid); 3445 ctx->pos = iter.tgid + TGID_OFFSET; 3446 if (!proc_fill_cache(file, ctx, name, len, 3447 proc_pid_instantiate, iter.task, NULL)) { 3448 put_task_struct(iter.task); 3449 return 0; 3450 } 3451 } 3452 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET; 3453 return 0; 3454 } 3455 3456 /* 3457 * proc_tid_comm_permission is a special permission function exclusively 3458 * used for the node /proc/<pid>/task/<tid>/comm. 3459 * It bypasses generic permission checks in the case where a task of the same 3460 * task group attempts to access the node. 3461 * The rationale behind this is that glibc and bionic access this node for 3462 * cross thread naming (pthread_set/getname_np(!self)). However, if 3463 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0, 3464 * which locks out the cross thread naming implementation. 3465 * This function makes sure that the node is always accessible for members of 3466 * same thread group. 3467 */ 3468 static int proc_tid_comm_permission(struct inode *inode, int mask) 3469 { 3470 bool is_same_tgroup; 3471 struct task_struct *task; 3472 3473 task = get_proc_task(inode); 3474 if (!task) 3475 return -ESRCH; 3476 is_same_tgroup = same_thread_group(current, task); 3477 put_task_struct(task); 3478 3479 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) { 3480 /* This file (/proc/<pid>/task/<tid>/comm) can always be 3481 * read or written by the members of the corresponding 3482 * thread group. 3483 */ 3484 return 0; 3485 } 3486 3487 return generic_permission(inode, mask); 3488 } 3489 3490 static const struct inode_operations proc_tid_comm_inode_operations = { 3491 .permission = proc_tid_comm_permission, 3492 }; 3493 3494 /* 3495 * Tasks 3496 */ 3497 static const struct pid_entry tid_base_stuff[] = { 3498 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3499 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3500 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3501 #ifdef CONFIG_NET 3502 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3503 #endif 3504 REG("environ", S_IRUSR, proc_environ_operations), 3505 REG("auxv", S_IRUSR, proc_auxv_operations), 3506 ONE("status", S_IRUGO, proc_pid_status), 3507 ONE("personality", S_IRUSR, proc_pid_personality), 3508 ONE("limits", S_IRUGO, proc_pid_limits), 3509 #ifdef CONFIG_SCHED_DEBUG 3510 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3511 #endif 3512 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR, 3513 &proc_tid_comm_inode_operations, 3514 &proc_pid_set_comm_operations, {}), 3515 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3516 ONE("syscall", S_IRUSR, proc_pid_syscall), 3517 #endif 3518 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 3519 ONE("stat", S_IRUGO, proc_tid_stat), 3520 ONE("statm", S_IRUGO, proc_pid_statm), 3521 REG("maps", S_IRUGO, proc_pid_maps_operations), 3522 #ifdef CONFIG_PROC_CHILDREN 3523 REG("children", S_IRUGO, proc_tid_children_operations), 3524 #endif 3525 #ifdef CONFIG_NUMA 3526 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 3527 #endif 3528 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3529 LNK("cwd", proc_cwd_link), 3530 LNK("root", proc_root_link), 3531 LNK("exe", proc_exe_link), 3532 REG("mounts", S_IRUGO, proc_mounts_operations), 3533 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3534 #ifdef CONFIG_PROC_PAGE_MONITOR 3535 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3536 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 3537 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations), 3538 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3539 #endif 3540 #ifdef CONFIG_SECURITY 3541 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3542 #endif 3543 #ifdef CONFIG_KALLSYMS 3544 ONE("wchan", S_IRUGO, proc_pid_wchan), 3545 #endif 3546 #ifdef CONFIG_STACKTRACE 3547 ONE("stack", S_IRUSR, proc_pid_stack), 3548 #endif 3549 #ifdef CONFIG_SCHED_INFO 3550 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 3551 #endif 3552 #ifdef CONFIG_LATENCYTOP 3553 REG("latency", S_IRUGO, proc_lstats_operations), 3554 #endif 3555 #ifdef CONFIG_PROC_PID_CPUSET 3556 ONE("cpuset", S_IRUGO, proc_cpuset_show), 3557 #endif 3558 #ifdef CONFIG_CGROUPS 3559 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3560 #endif 3561 #ifdef CONFIG_PROC_CPU_RESCTRL 3562 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show), 3563 #endif 3564 ONE("oom_score", S_IRUGO, proc_oom_score), 3565 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3566 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3567 #ifdef CONFIG_AUDIT 3568 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3569 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3570 #endif 3571 #ifdef CONFIG_FAULT_INJECTION 3572 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3573 REG("fail-nth", 0644, proc_fail_nth_operations), 3574 #endif 3575 #ifdef CONFIG_TASK_IO_ACCOUNTING 3576 ONE("io", S_IRUSR, proc_tid_io_accounting), 3577 #endif 3578 #ifdef CONFIG_USER_NS 3579 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3580 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3581 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3582 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3583 #endif 3584 #ifdef CONFIG_LIVEPATCH 3585 ONE("patch_state", S_IRUSR, proc_pid_patch_state), 3586 #endif 3587 #ifdef CONFIG_PROC_PID_ARCH_STATUS 3588 ONE("arch_status", S_IRUGO, proc_pid_arch_status), 3589 #endif 3590 }; 3591 3592 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx) 3593 { 3594 return proc_pident_readdir(file, ctx, 3595 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3596 } 3597 3598 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3599 { 3600 return proc_pident_lookup(dir, dentry, 3601 tid_base_stuff, 3602 tid_base_stuff + ARRAY_SIZE(tid_base_stuff)); 3603 } 3604 3605 static const struct file_operations proc_tid_base_operations = { 3606 .read = generic_read_dir, 3607 .iterate_shared = proc_tid_base_readdir, 3608 .llseek = generic_file_llseek, 3609 }; 3610 3611 static const struct inode_operations proc_tid_base_inode_operations = { 3612 .lookup = proc_tid_base_lookup, 3613 .getattr = pid_getattr, 3614 .setattr = proc_setattr, 3615 }; 3616 3617 static struct dentry *proc_task_instantiate(struct dentry *dentry, 3618 struct task_struct *task, const void *ptr) 3619 { 3620 struct inode *inode; 3621 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3622 if (!inode) 3623 return ERR_PTR(-ENOENT); 3624 3625 inode->i_op = &proc_tid_base_inode_operations; 3626 inode->i_fop = &proc_tid_base_operations; 3627 inode->i_flags |= S_IMMUTABLE; 3628 3629 set_nlink(inode, nlink_tid); 3630 pid_update_inode(task, inode); 3631 3632 d_set_d_op(dentry, &pid_dentry_operations); 3633 return d_splice_alias(inode, dentry); 3634 } 3635 3636 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3637 { 3638 struct task_struct *task; 3639 struct task_struct *leader = get_proc_task(dir); 3640 unsigned tid; 3641 struct pid_namespace *ns; 3642 struct dentry *result = ERR_PTR(-ENOENT); 3643 3644 if (!leader) 3645 goto out_no_task; 3646 3647 tid = name_to_int(&dentry->d_name); 3648 if (tid == ~0U) 3649 goto out; 3650 3651 ns = dentry->d_sb->s_fs_info; 3652 rcu_read_lock(); 3653 task = find_task_by_pid_ns(tid, ns); 3654 if (task) 3655 get_task_struct(task); 3656 rcu_read_unlock(); 3657 if (!task) 3658 goto out; 3659 if (!same_thread_group(leader, task)) 3660 goto out_drop_task; 3661 3662 result = proc_task_instantiate(dentry, task, NULL); 3663 out_drop_task: 3664 put_task_struct(task); 3665 out: 3666 put_task_struct(leader); 3667 out_no_task: 3668 return result; 3669 } 3670 3671 /* 3672 * Find the first tid of a thread group to return to user space. 3673 * 3674 * Usually this is just the thread group leader, but if the users 3675 * buffer was too small or there was a seek into the middle of the 3676 * directory we have more work todo. 3677 * 3678 * In the case of a short read we start with find_task_by_pid. 3679 * 3680 * In the case of a seek we start with the leader and walk nr 3681 * threads past it. 3682 */ 3683 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos, 3684 struct pid_namespace *ns) 3685 { 3686 struct task_struct *pos, *task; 3687 unsigned long nr = f_pos; 3688 3689 if (nr != f_pos) /* 32bit overflow? */ 3690 return NULL; 3691 3692 rcu_read_lock(); 3693 task = pid_task(pid, PIDTYPE_PID); 3694 if (!task) 3695 goto fail; 3696 3697 /* Attempt to start with the tid of a thread */ 3698 if (tid && nr) { 3699 pos = find_task_by_pid_ns(tid, ns); 3700 if (pos && same_thread_group(pos, task)) 3701 goto found; 3702 } 3703 3704 /* If nr exceeds the number of threads there is nothing todo */ 3705 if (nr >= get_nr_threads(task)) 3706 goto fail; 3707 3708 /* If we haven't found our starting place yet start 3709 * with the leader and walk nr threads forward. 3710 */ 3711 pos = task = task->group_leader; 3712 do { 3713 if (!nr--) 3714 goto found; 3715 } while_each_thread(task, pos); 3716 fail: 3717 pos = NULL; 3718 goto out; 3719 found: 3720 get_task_struct(pos); 3721 out: 3722 rcu_read_unlock(); 3723 return pos; 3724 } 3725 3726 /* 3727 * Find the next thread in the thread list. 3728 * Return NULL if there is an error or no next thread. 3729 * 3730 * The reference to the input task_struct is released. 3731 */ 3732 static struct task_struct *next_tid(struct task_struct *start) 3733 { 3734 struct task_struct *pos = NULL; 3735 rcu_read_lock(); 3736 if (pid_alive(start)) { 3737 pos = next_thread(start); 3738 if (thread_group_leader(pos)) 3739 pos = NULL; 3740 else 3741 get_task_struct(pos); 3742 } 3743 rcu_read_unlock(); 3744 put_task_struct(start); 3745 return pos; 3746 } 3747 3748 /* for the /proc/TGID/task/ directories */ 3749 static int proc_task_readdir(struct file *file, struct dir_context *ctx) 3750 { 3751 struct inode *inode = file_inode(file); 3752 struct task_struct *task; 3753 struct pid_namespace *ns; 3754 int tid; 3755 3756 if (proc_inode_is_dead(inode)) 3757 return -ENOENT; 3758 3759 if (!dir_emit_dots(file, ctx)) 3760 return 0; 3761 3762 /* f_version caches the tgid value that the last readdir call couldn't 3763 * return. lseek aka telldir automagically resets f_version to 0. 3764 */ 3765 ns = proc_pid_ns(inode); 3766 tid = (int)file->f_version; 3767 file->f_version = 0; 3768 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); 3769 task; 3770 task = next_tid(task), ctx->pos++) { 3771 char name[10 + 1]; 3772 unsigned int len; 3773 tid = task_pid_nr_ns(task, ns); 3774 len = snprintf(name, sizeof(name), "%u", tid); 3775 if (!proc_fill_cache(file, ctx, name, len, 3776 proc_task_instantiate, task, NULL)) { 3777 /* returning this tgid failed, save it as the first 3778 * pid for the next readir call */ 3779 file->f_version = (u64)tid; 3780 put_task_struct(task); 3781 break; 3782 } 3783 } 3784 3785 return 0; 3786 } 3787 3788 static int proc_task_getattr(const struct path *path, struct kstat *stat, 3789 u32 request_mask, unsigned int query_flags) 3790 { 3791 struct inode *inode = d_inode(path->dentry); 3792 struct task_struct *p = get_proc_task(inode); 3793 generic_fillattr(inode, stat); 3794 3795 if (p) { 3796 stat->nlink += get_nr_threads(p); 3797 put_task_struct(p); 3798 } 3799 3800 return 0; 3801 } 3802 3803 static const struct inode_operations proc_task_inode_operations = { 3804 .lookup = proc_task_lookup, 3805 .getattr = proc_task_getattr, 3806 .setattr = proc_setattr, 3807 .permission = proc_pid_permission, 3808 }; 3809 3810 static const struct file_operations proc_task_operations = { 3811 .read = generic_read_dir, 3812 .iterate_shared = proc_task_readdir, 3813 .llseek = generic_file_llseek, 3814 }; 3815 3816 void __init set_proc_pid_nlink(void) 3817 { 3818 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3819 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3820 } 3821