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->exec_update_mutex); 409 if (err) 410 return err; 411 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) { 412 mutex_unlock(&task->signal->exec_update_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->exec_update_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 void proc_pid_evict_inode(struct proc_inode *ei) 1838 { 1839 struct pid *pid = ei->pid; 1840 1841 if (S_ISDIR(ei->vfs_inode.i_mode)) { 1842 spin_lock(&pid->lock); 1843 hlist_del_init_rcu(&ei->sibling_inodes); 1844 spin_unlock(&pid->lock); 1845 } 1846 1847 put_pid(pid); 1848 } 1849 1850 struct inode *proc_pid_make_inode(struct super_block * sb, 1851 struct task_struct *task, umode_t mode) 1852 { 1853 struct inode * inode; 1854 struct proc_inode *ei; 1855 struct pid *pid; 1856 1857 /* We need a new inode */ 1858 1859 inode = new_inode(sb); 1860 if (!inode) 1861 goto out; 1862 1863 /* Common stuff */ 1864 ei = PROC_I(inode); 1865 inode->i_mode = mode; 1866 inode->i_ino = get_next_ino(); 1867 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 1868 inode->i_op = &proc_def_inode_operations; 1869 1870 /* 1871 * grab the reference to task. 1872 */ 1873 pid = get_task_pid(task, PIDTYPE_PID); 1874 if (!pid) 1875 goto out_unlock; 1876 1877 /* Let the pid remember us for quick removal */ 1878 ei->pid = pid; 1879 if (S_ISDIR(mode)) { 1880 spin_lock(&pid->lock); 1881 hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes); 1882 spin_unlock(&pid->lock); 1883 } 1884 1885 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); 1886 security_task_to_inode(task, inode); 1887 1888 out: 1889 return inode; 1890 1891 out_unlock: 1892 iput(inode); 1893 return NULL; 1894 } 1895 1896 int pid_getattr(const struct path *path, struct kstat *stat, 1897 u32 request_mask, unsigned int query_flags) 1898 { 1899 struct inode *inode = d_inode(path->dentry); 1900 struct pid_namespace *pid = proc_pid_ns(inode); 1901 struct task_struct *task; 1902 1903 generic_fillattr(inode, stat); 1904 1905 stat->uid = GLOBAL_ROOT_UID; 1906 stat->gid = GLOBAL_ROOT_GID; 1907 rcu_read_lock(); 1908 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1909 if (task) { 1910 if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) { 1911 rcu_read_unlock(); 1912 /* 1913 * This doesn't prevent learning whether PID exists, 1914 * it only makes getattr() consistent with readdir(). 1915 */ 1916 return -ENOENT; 1917 } 1918 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid); 1919 } 1920 rcu_read_unlock(); 1921 return 0; 1922 } 1923 1924 /* dentry stuff */ 1925 1926 /* 1927 * Set <pid>/... inode ownership (can change due to setuid(), etc.) 1928 */ 1929 void pid_update_inode(struct task_struct *task, struct inode *inode) 1930 { 1931 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid); 1932 1933 inode->i_mode &= ~(S_ISUID | S_ISGID); 1934 security_task_to_inode(task, inode); 1935 } 1936 1937 /* 1938 * Rewrite the inode's ownerships here because the owning task may have 1939 * performed a setuid(), etc. 1940 * 1941 */ 1942 static int pid_revalidate(struct dentry *dentry, unsigned int flags) 1943 { 1944 struct inode *inode; 1945 struct task_struct *task; 1946 1947 if (flags & LOOKUP_RCU) 1948 return -ECHILD; 1949 1950 inode = d_inode(dentry); 1951 task = get_proc_task(inode); 1952 1953 if (task) { 1954 pid_update_inode(task, inode); 1955 put_task_struct(task); 1956 return 1; 1957 } 1958 return 0; 1959 } 1960 1961 static inline bool proc_inode_is_dead(struct inode *inode) 1962 { 1963 return !proc_pid(inode)->tasks[PIDTYPE_PID].first; 1964 } 1965 1966 int pid_delete_dentry(const struct dentry *dentry) 1967 { 1968 /* Is the task we represent dead? 1969 * If so, then don't put the dentry on the lru list, 1970 * kill it immediately. 1971 */ 1972 return proc_inode_is_dead(d_inode(dentry)); 1973 } 1974 1975 const struct dentry_operations pid_dentry_operations = 1976 { 1977 .d_revalidate = pid_revalidate, 1978 .d_delete = pid_delete_dentry, 1979 }; 1980 1981 /* Lookups */ 1982 1983 /* 1984 * Fill a directory entry. 1985 * 1986 * If possible create the dcache entry and derive our inode number and 1987 * file type from dcache entry. 1988 * 1989 * Since all of the proc inode numbers are dynamically generated, the inode 1990 * numbers do not exist until the inode is cache. This means creating the 1991 * the dcache entry in readdir is necessary to keep the inode numbers 1992 * reported by readdir in sync with the inode numbers reported 1993 * by stat. 1994 */ 1995 bool proc_fill_cache(struct file *file, struct dir_context *ctx, 1996 const char *name, unsigned int len, 1997 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1998 { 1999 struct dentry *child, *dir = file->f_path.dentry; 2000 struct qstr qname = QSTR_INIT(name, len); 2001 struct inode *inode; 2002 unsigned type = DT_UNKNOWN; 2003 ino_t ino = 1; 2004 2005 child = d_hash_and_lookup(dir, &qname); 2006 if (!child) { 2007 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 2008 child = d_alloc_parallel(dir, &qname, &wq); 2009 if (IS_ERR(child)) 2010 goto end_instantiate; 2011 if (d_in_lookup(child)) { 2012 struct dentry *res; 2013 res = instantiate(child, task, ptr); 2014 d_lookup_done(child); 2015 if (unlikely(res)) { 2016 dput(child); 2017 child = res; 2018 if (IS_ERR(child)) 2019 goto end_instantiate; 2020 } 2021 } 2022 } 2023 inode = d_inode(child); 2024 ino = inode->i_ino; 2025 type = inode->i_mode >> 12; 2026 dput(child); 2027 end_instantiate: 2028 return dir_emit(ctx, name, len, ino, type); 2029 } 2030 2031 /* 2032 * dname_to_vma_addr - maps a dentry name into two unsigned longs 2033 * which represent vma start and end addresses. 2034 */ 2035 static int dname_to_vma_addr(struct dentry *dentry, 2036 unsigned long *start, unsigned long *end) 2037 { 2038 const char *str = dentry->d_name.name; 2039 unsigned long long sval, eval; 2040 unsigned int len; 2041 2042 if (str[0] == '0' && str[1] != '-') 2043 return -EINVAL; 2044 len = _parse_integer(str, 16, &sval); 2045 if (len & KSTRTOX_OVERFLOW) 2046 return -EINVAL; 2047 if (sval != (unsigned long)sval) 2048 return -EINVAL; 2049 str += len; 2050 2051 if (*str != '-') 2052 return -EINVAL; 2053 str++; 2054 2055 if (str[0] == '0' && str[1]) 2056 return -EINVAL; 2057 len = _parse_integer(str, 16, &eval); 2058 if (len & KSTRTOX_OVERFLOW) 2059 return -EINVAL; 2060 if (eval != (unsigned long)eval) 2061 return -EINVAL; 2062 str += len; 2063 2064 if (*str != '\0') 2065 return -EINVAL; 2066 2067 *start = sval; 2068 *end = eval; 2069 2070 return 0; 2071 } 2072 2073 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags) 2074 { 2075 unsigned long vm_start, vm_end; 2076 bool exact_vma_exists = false; 2077 struct mm_struct *mm = NULL; 2078 struct task_struct *task; 2079 struct inode *inode; 2080 int status = 0; 2081 2082 if (flags & LOOKUP_RCU) 2083 return -ECHILD; 2084 2085 inode = d_inode(dentry); 2086 task = get_proc_task(inode); 2087 if (!task) 2088 goto out_notask; 2089 2090 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); 2091 if (IS_ERR_OR_NULL(mm)) 2092 goto out; 2093 2094 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 2095 status = down_read_killable(&mm->mmap_sem); 2096 if (!status) { 2097 exact_vma_exists = !!find_exact_vma(mm, vm_start, 2098 vm_end); 2099 up_read(&mm->mmap_sem); 2100 } 2101 } 2102 2103 mmput(mm); 2104 2105 if (exact_vma_exists) { 2106 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); 2107 2108 security_task_to_inode(task, inode); 2109 status = 1; 2110 } 2111 2112 out: 2113 put_task_struct(task); 2114 2115 out_notask: 2116 return status; 2117 } 2118 2119 static const struct dentry_operations tid_map_files_dentry_operations = { 2120 .d_revalidate = map_files_d_revalidate, 2121 .d_delete = pid_delete_dentry, 2122 }; 2123 2124 static int map_files_get_link(struct dentry *dentry, struct path *path) 2125 { 2126 unsigned long vm_start, vm_end; 2127 struct vm_area_struct *vma; 2128 struct task_struct *task; 2129 struct mm_struct *mm; 2130 int rc; 2131 2132 rc = -ENOENT; 2133 task = get_proc_task(d_inode(dentry)); 2134 if (!task) 2135 goto out; 2136 2137 mm = get_task_mm(task); 2138 put_task_struct(task); 2139 if (!mm) 2140 goto out; 2141 2142 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 2143 if (rc) 2144 goto out_mmput; 2145 2146 rc = down_read_killable(&mm->mmap_sem); 2147 if (rc) 2148 goto out_mmput; 2149 2150 rc = -ENOENT; 2151 vma = find_exact_vma(mm, vm_start, vm_end); 2152 if (vma && vma->vm_file) { 2153 *path = vma->vm_file->f_path; 2154 path_get(path); 2155 rc = 0; 2156 } 2157 up_read(&mm->mmap_sem); 2158 2159 out_mmput: 2160 mmput(mm); 2161 out: 2162 return rc; 2163 } 2164 2165 struct map_files_info { 2166 unsigned long start; 2167 unsigned long end; 2168 fmode_t mode; 2169 }; 2170 2171 /* 2172 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the 2173 * symlinks may be used to bypass permissions on ancestor directories in the 2174 * path to the file in question. 2175 */ 2176 static const char * 2177 proc_map_files_get_link(struct dentry *dentry, 2178 struct inode *inode, 2179 struct delayed_call *done) 2180 { 2181 if (!capable(CAP_SYS_ADMIN)) 2182 return ERR_PTR(-EPERM); 2183 2184 return proc_pid_get_link(dentry, inode, done); 2185 } 2186 2187 /* 2188 * Identical to proc_pid_link_inode_operations except for get_link() 2189 */ 2190 static const struct inode_operations proc_map_files_link_inode_operations = { 2191 .readlink = proc_pid_readlink, 2192 .get_link = proc_map_files_get_link, 2193 .setattr = proc_setattr, 2194 }; 2195 2196 static struct dentry * 2197 proc_map_files_instantiate(struct dentry *dentry, 2198 struct task_struct *task, const void *ptr) 2199 { 2200 fmode_t mode = (fmode_t)(unsigned long)ptr; 2201 struct proc_inode *ei; 2202 struct inode *inode; 2203 2204 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK | 2205 ((mode & FMODE_READ ) ? S_IRUSR : 0) | 2206 ((mode & FMODE_WRITE) ? S_IWUSR : 0)); 2207 if (!inode) 2208 return ERR_PTR(-ENOENT); 2209 2210 ei = PROC_I(inode); 2211 ei->op.proc_get_link = map_files_get_link; 2212 2213 inode->i_op = &proc_map_files_link_inode_operations; 2214 inode->i_size = 64; 2215 2216 d_set_d_op(dentry, &tid_map_files_dentry_operations); 2217 return d_splice_alias(inode, dentry); 2218 } 2219 2220 static struct dentry *proc_map_files_lookup(struct inode *dir, 2221 struct dentry *dentry, unsigned int flags) 2222 { 2223 unsigned long vm_start, vm_end; 2224 struct vm_area_struct *vma; 2225 struct task_struct *task; 2226 struct dentry *result; 2227 struct mm_struct *mm; 2228 2229 result = ERR_PTR(-ENOENT); 2230 task = get_proc_task(dir); 2231 if (!task) 2232 goto out; 2233 2234 result = ERR_PTR(-EACCES); 2235 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2236 goto out_put_task; 2237 2238 result = ERR_PTR(-ENOENT); 2239 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 2240 goto out_put_task; 2241 2242 mm = get_task_mm(task); 2243 if (!mm) 2244 goto out_put_task; 2245 2246 result = ERR_PTR(-EINTR); 2247 if (down_read_killable(&mm->mmap_sem)) 2248 goto out_put_mm; 2249 2250 result = ERR_PTR(-ENOENT); 2251 vma = find_exact_vma(mm, vm_start, vm_end); 2252 if (!vma) 2253 goto out_no_vma; 2254 2255 if (vma->vm_file) 2256 result = proc_map_files_instantiate(dentry, task, 2257 (void *)(unsigned long)vma->vm_file->f_mode); 2258 2259 out_no_vma: 2260 up_read(&mm->mmap_sem); 2261 out_put_mm: 2262 mmput(mm); 2263 out_put_task: 2264 put_task_struct(task); 2265 out: 2266 return result; 2267 } 2268 2269 static const struct inode_operations proc_map_files_inode_operations = { 2270 .lookup = proc_map_files_lookup, 2271 .permission = proc_fd_permission, 2272 .setattr = proc_setattr, 2273 }; 2274 2275 static int 2276 proc_map_files_readdir(struct file *file, struct dir_context *ctx) 2277 { 2278 struct vm_area_struct *vma; 2279 struct task_struct *task; 2280 struct mm_struct *mm; 2281 unsigned long nr_files, pos, i; 2282 GENRADIX(struct map_files_info) fa; 2283 struct map_files_info *p; 2284 int ret; 2285 2286 genradix_init(&fa); 2287 2288 ret = -ENOENT; 2289 task = get_proc_task(file_inode(file)); 2290 if (!task) 2291 goto out; 2292 2293 ret = -EACCES; 2294 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) 2295 goto out_put_task; 2296 2297 ret = 0; 2298 if (!dir_emit_dots(file, ctx)) 2299 goto out_put_task; 2300 2301 mm = get_task_mm(task); 2302 if (!mm) 2303 goto out_put_task; 2304 2305 ret = down_read_killable(&mm->mmap_sem); 2306 if (ret) { 2307 mmput(mm); 2308 goto out_put_task; 2309 } 2310 2311 nr_files = 0; 2312 2313 /* 2314 * We need two passes here: 2315 * 2316 * 1) Collect vmas of mapped files with mmap_sem taken 2317 * 2) Release mmap_sem and instantiate entries 2318 * 2319 * otherwise we get lockdep complained, since filldir() 2320 * routine might require mmap_sem taken in might_fault(). 2321 */ 2322 2323 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 2324 if (!vma->vm_file) 2325 continue; 2326 if (++pos <= ctx->pos) 2327 continue; 2328 2329 p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL); 2330 if (!p) { 2331 ret = -ENOMEM; 2332 up_read(&mm->mmap_sem); 2333 mmput(mm); 2334 goto out_put_task; 2335 } 2336 2337 p->start = vma->vm_start; 2338 p->end = vma->vm_end; 2339 p->mode = vma->vm_file->f_mode; 2340 } 2341 up_read(&mm->mmap_sem); 2342 mmput(mm); 2343 2344 for (i = 0; i < nr_files; i++) { 2345 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */ 2346 unsigned int len; 2347 2348 p = genradix_ptr(&fa, i); 2349 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end); 2350 if (!proc_fill_cache(file, ctx, 2351 buf, len, 2352 proc_map_files_instantiate, 2353 task, 2354 (void *)(unsigned long)p->mode)) 2355 break; 2356 ctx->pos++; 2357 } 2358 2359 out_put_task: 2360 put_task_struct(task); 2361 out: 2362 genradix_free(&fa); 2363 return ret; 2364 } 2365 2366 static const struct file_operations proc_map_files_operations = { 2367 .read = generic_read_dir, 2368 .iterate_shared = proc_map_files_readdir, 2369 .llseek = generic_file_llseek, 2370 }; 2371 2372 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS) 2373 struct timers_private { 2374 struct pid *pid; 2375 struct task_struct *task; 2376 struct sighand_struct *sighand; 2377 struct pid_namespace *ns; 2378 unsigned long flags; 2379 }; 2380 2381 static void *timers_start(struct seq_file *m, loff_t *pos) 2382 { 2383 struct timers_private *tp = m->private; 2384 2385 tp->task = get_pid_task(tp->pid, PIDTYPE_PID); 2386 if (!tp->task) 2387 return ERR_PTR(-ESRCH); 2388 2389 tp->sighand = lock_task_sighand(tp->task, &tp->flags); 2390 if (!tp->sighand) 2391 return ERR_PTR(-ESRCH); 2392 2393 return seq_list_start(&tp->task->signal->posix_timers, *pos); 2394 } 2395 2396 static void *timers_next(struct seq_file *m, void *v, loff_t *pos) 2397 { 2398 struct timers_private *tp = m->private; 2399 return seq_list_next(v, &tp->task->signal->posix_timers, pos); 2400 } 2401 2402 static void timers_stop(struct seq_file *m, void *v) 2403 { 2404 struct timers_private *tp = m->private; 2405 2406 if (tp->sighand) { 2407 unlock_task_sighand(tp->task, &tp->flags); 2408 tp->sighand = NULL; 2409 } 2410 2411 if (tp->task) { 2412 put_task_struct(tp->task); 2413 tp->task = NULL; 2414 } 2415 } 2416 2417 static int show_timer(struct seq_file *m, void *v) 2418 { 2419 struct k_itimer *timer; 2420 struct timers_private *tp = m->private; 2421 int notify; 2422 static const char * const nstr[] = { 2423 [SIGEV_SIGNAL] = "signal", 2424 [SIGEV_NONE] = "none", 2425 [SIGEV_THREAD] = "thread", 2426 }; 2427 2428 timer = list_entry((struct list_head *)v, struct k_itimer, list); 2429 notify = timer->it_sigev_notify; 2430 2431 seq_printf(m, "ID: %d\n", timer->it_id); 2432 seq_printf(m, "signal: %d/%px\n", 2433 timer->sigq->info.si_signo, 2434 timer->sigq->info.si_value.sival_ptr); 2435 seq_printf(m, "notify: %s/%s.%d\n", 2436 nstr[notify & ~SIGEV_THREAD_ID], 2437 (notify & SIGEV_THREAD_ID) ? "tid" : "pid", 2438 pid_nr_ns(timer->it_pid, tp->ns)); 2439 seq_printf(m, "ClockID: %d\n", timer->it_clock); 2440 2441 return 0; 2442 } 2443 2444 static const struct seq_operations proc_timers_seq_ops = { 2445 .start = timers_start, 2446 .next = timers_next, 2447 .stop = timers_stop, 2448 .show = show_timer, 2449 }; 2450 2451 static int proc_timers_open(struct inode *inode, struct file *file) 2452 { 2453 struct timers_private *tp; 2454 2455 tp = __seq_open_private(file, &proc_timers_seq_ops, 2456 sizeof(struct timers_private)); 2457 if (!tp) 2458 return -ENOMEM; 2459 2460 tp->pid = proc_pid(inode); 2461 tp->ns = proc_pid_ns(inode); 2462 return 0; 2463 } 2464 2465 static const struct file_operations proc_timers_operations = { 2466 .open = proc_timers_open, 2467 .read = seq_read, 2468 .llseek = seq_lseek, 2469 .release = seq_release_private, 2470 }; 2471 #endif 2472 2473 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf, 2474 size_t count, loff_t *offset) 2475 { 2476 struct inode *inode = file_inode(file); 2477 struct task_struct *p; 2478 u64 slack_ns; 2479 int err; 2480 2481 err = kstrtoull_from_user(buf, count, 10, &slack_ns); 2482 if (err < 0) 2483 return err; 2484 2485 p = get_proc_task(inode); 2486 if (!p) 2487 return -ESRCH; 2488 2489 if (p != current) { 2490 rcu_read_lock(); 2491 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { 2492 rcu_read_unlock(); 2493 count = -EPERM; 2494 goto out; 2495 } 2496 rcu_read_unlock(); 2497 2498 err = security_task_setscheduler(p); 2499 if (err) { 2500 count = err; 2501 goto out; 2502 } 2503 } 2504 2505 task_lock(p); 2506 if (slack_ns == 0) 2507 p->timer_slack_ns = p->default_timer_slack_ns; 2508 else 2509 p->timer_slack_ns = slack_ns; 2510 task_unlock(p); 2511 2512 out: 2513 put_task_struct(p); 2514 2515 return count; 2516 } 2517 2518 static int timerslack_ns_show(struct seq_file *m, void *v) 2519 { 2520 struct inode *inode = m->private; 2521 struct task_struct *p; 2522 int err = 0; 2523 2524 p = get_proc_task(inode); 2525 if (!p) 2526 return -ESRCH; 2527 2528 if (p != current) { 2529 rcu_read_lock(); 2530 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { 2531 rcu_read_unlock(); 2532 err = -EPERM; 2533 goto out; 2534 } 2535 rcu_read_unlock(); 2536 2537 err = security_task_getscheduler(p); 2538 if (err) 2539 goto out; 2540 } 2541 2542 task_lock(p); 2543 seq_printf(m, "%llu\n", p->timer_slack_ns); 2544 task_unlock(p); 2545 2546 out: 2547 put_task_struct(p); 2548 2549 return err; 2550 } 2551 2552 static int timerslack_ns_open(struct inode *inode, struct file *filp) 2553 { 2554 return single_open(filp, timerslack_ns_show, inode); 2555 } 2556 2557 static const struct file_operations proc_pid_set_timerslack_ns_operations = { 2558 .open = timerslack_ns_open, 2559 .read = seq_read, 2560 .write = timerslack_ns_write, 2561 .llseek = seq_lseek, 2562 .release = single_release, 2563 }; 2564 2565 static struct dentry *proc_pident_instantiate(struct dentry *dentry, 2566 struct task_struct *task, const void *ptr) 2567 { 2568 const struct pid_entry *p = ptr; 2569 struct inode *inode; 2570 struct proc_inode *ei; 2571 2572 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode); 2573 if (!inode) 2574 return ERR_PTR(-ENOENT); 2575 2576 ei = PROC_I(inode); 2577 if (S_ISDIR(inode->i_mode)) 2578 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2579 if (p->iop) 2580 inode->i_op = p->iop; 2581 if (p->fop) 2582 inode->i_fop = p->fop; 2583 ei->op = p->op; 2584 pid_update_inode(task, inode); 2585 d_set_d_op(dentry, &pid_dentry_operations); 2586 return d_splice_alias(inode, dentry); 2587 } 2588 2589 static struct dentry *proc_pident_lookup(struct inode *dir, 2590 struct dentry *dentry, 2591 const struct pid_entry *p, 2592 const struct pid_entry *end) 2593 { 2594 struct task_struct *task = get_proc_task(dir); 2595 struct dentry *res = ERR_PTR(-ENOENT); 2596 2597 if (!task) 2598 goto out_no_task; 2599 2600 /* 2601 * Yes, it does not scale. And it should not. Don't add 2602 * new entries into /proc/<tgid>/ without very good reasons. 2603 */ 2604 for (; p < end; p++) { 2605 if (p->len != dentry->d_name.len) 2606 continue; 2607 if (!memcmp(dentry->d_name.name, p->name, p->len)) { 2608 res = proc_pident_instantiate(dentry, task, p); 2609 break; 2610 } 2611 } 2612 put_task_struct(task); 2613 out_no_task: 2614 return res; 2615 } 2616 2617 static int proc_pident_readdir(struct file *file, struct dir_context *ctx, 2618 const struct pid_entry *ents, unsigned int nents) 2619 { 2620 struct task_struct *task = get_proc_task(file_inode(file)); 2621 const struct pid_entry *p; 2622 2623 if (!task) 2624 return -ENOENT; 2625 2626 if (!dir_emit_dots(file, ctx)) 2627 goto out; 2628 2629 if (ctx->pos >= nents + 2) 2630 goto out; 2631 2632 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) { 2633 if (!proc_fill_cache(file, ctx, p->name, p->len, 2634 proc_pident_instantiate, task, p)) 2635 break; 2636 ctx->pos++; 2637 } 2638 out: 2639 put_task_struct(task); 2640 return 0; 2641 } 2642 2643 #ifdef CONFIG_SECURITY 2644 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2645 size_t count, loff_t *ppos) 2646 { 2647 struct inode * inode = file_inode(file); 2648 char *p = NULL; 2649 ssize_t length; 2650 struct task_struct *task = get_proc_task(inode); 2651 2652 if (!task) 2653 return -ESRCH; 2654 2655 length = security_getprocattr(task, PROC_I(inode)->op.lsm, 2656 (char*)file->f_path.dentry->d_name.name, 2657 &p); 2658 put_task_struct(task); 2659 if (length > 0) 2660 length = simple_read_from_buffer(buf, count, ppos, p, length); 2661 kfree(p); 2662 return length; 2663 } 2664 2665 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2666 size_t count, loff_t *ppos) 2667 { 2668 struct inode * inode = file_inode(file); 2669 struct task_struct *task; 2670 void *page; 2671 int rv; 2672 2673 rcu_read_lock(); 2674 task = pid_task(proc_pid(inode), PIDTYPE_PID); 2675 if (!task) { 2676 rcu_read_unlock(); 2677 return -ESRCH; 2678 } 2679 /* A task may only write its own attributes. */ 2680 if (current != task) { 2681 rcu_read_unlock(); 2682 return -EACCES; 2683 } 2684 /* Prevent changes to overridden credentials. */ 2685 if (current_cred() != current_real_cred()) { 2686 rcu_read_unlock(); 2687 return -EBUSY; 2688 } 2689 rcu_read_unlock(); 2690 2691 if (count > PAGE_SIZE) 2692 count = PAGE_SIZE; 2693 2694 /* No partial writes. */ 2695 if (*ppos != 0) 2696 return -EINVAL; 2697 2698 page = memdup_user(buf, count); 2699 if (IS_ERR(page)) { 2700 rv = PTR_ERR(page); 2701 goto out; 2702 } 2703 2704 /* Guard against adverse ptrace interaction */ 2705 rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex); 2706 if (rv < 0) 2707 goto out_free; 2708 2709 rv = security_setprocattr(PROC_I(inode)->op.lsm, 2710 file->f_path.dentry->d_name.name, page, 2711 count); 2712 mutex_unlock(¤t->signal->cred_guard_mutex); 2713 out_free: 2714 kfree(page); 2715 out: 2716 return rv; 2717 } 2718 2719 static const struct file_operations proc_pid_attr_operations = { 2720 .read = proc_pid_attr_read, 2721 .write = proc_pid_attr_write, 2722 .llseek = generic_file_llseek, 2723 }; 2724 2725 #define LSM_DIR_OPS(LSM) \ 2726 static int proc_##LSM##_attr_dir_iterate(struct file *filp, \ 2727 struct dir_context *ctx) \ 2728 { \ 2729 return proc_pident_readdir(filp, ctx, \ 2730 LSM##_attr_dir_stuff, \ 2731 ARRAY_SIZE(LSM##_attr_dir_stuff)); \ 2732 } \ 2733 \ 2734 static const struct file_operations proc_##LSM##_attr_dir_ops = { \ 2735 .read = generic_read_dir, \ 2736 .iterate = proc_##LSM##_attr_dir_iterate, \ 2737 .llseek = default_llseek, \ 2738 }; \ 2739 \ 2740 static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \ 2741 struct dentry *dentry, unsigned int flags) \ 2742 { \ 2743 return proc_pident_lookup(dir, dentry, \ 2744 LSM##_attr_dir_stuff, \ 2745 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \ 2746 } \ 2747 \ 2748 static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \ 2749 .lookup = proc_##LSM##_attr_dir_lookup, \ 2750 .getattr = pid_getattr, \ 2751 .setattr = proc_setattr, \ 2752 } 2753 2754 #ifdef CONFIG_SECURITY_SMACK 2755 static const struct pid_entry smack_attr_dir_stuff[] = { 2756 ATTR("smack", "current", 0666), 2757 }; 2758 LSM_DIR_OPS(smack); 2759 #endif 2760 2761 static const struct pid_entry attr_dir_stuff[] = { 2762 ATTR(NULL, "current", 0666), 2763 ATTR(NULL, "prev", 0444), 2764 ATTR(NULL, "exec", 0666), 2765 ATTR(NULL, "fscreate", 0666), 2766 ATTR(NULL, "keycreate", 0666), 2767 ATTR(NULL, "sockcreate", 0666), 2768 #ifdef CONFIG_SECURITY_SMACK 2769 DIR("smack", 0555, 2770 proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops), 2771 #endif 2772 }; 2773 2774 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx) 2775 { 2776 return proc_pident_readdir(file, ctx, 2777 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2778 } 2779 2780 static const struct file_operations proc_attr_dir_operations = { 2781 .read = generic_read_dir, 2782 .iterate_shared = proc_attr_dir_readdir, 2783 .llseek = generic_file_llseek, 2784 }; 2785 2786 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2787 struct dentry *dentry, unsigned int flags) 2788 { 2789 return proc_pident_lookup(dir, dentry, 2790 attr_dir_stuff, 2791 attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff)); 2792 } 2793 2794 static const struct inode_operations proc_attr_dir_inode_operations = { 2795 .lookup = proc_attr_dir_lookup, 2796 .getattr = pid_getattr, 2797 .setattr = proc_setattr, 2798 }; 2799 2800 #endif 2801 2802 #ifdef CONFIG_ELF_CORE 2803 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2804 size_t count, loff_t *ppos) 2805 { 2806 struct task_struct *task = get_proc_task(file_inode(file)); 2807 struct mm_struct *mm; 2808 char buffer[PROC_NUMBUF]; 2809 size_t len; 2810 int ret; 2811 2812 if (!task) 2813 return -ESRCH; 2814 2815 ret = 0; 2816 mm = get_task_mm(task); 2817 if (mm) { 2818 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2819 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2820 MMF_DUMP_FILTER_SHIFT)); 2821 mmput(mm); 2822 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2823 } 2824 2825 put_task_struct(task); 2826 2827 return ret; 2828 } 2829 2830 static ssize_t proc_coredump_filter_write(struct file *file, 2831 const char __user *buf, 2832 size_t count, 2833 loff_t *ppos) 2834 { 2835 struct task_struct *task; 2836 struct mm_struct *mm; 2837 unsigned int val; 2838 int ret; 2839 int i; 2840 unsigned long mask; 2841 2842 ret = kstrtouint_from_user(buf, count, 0, &val); 2843 if (ret < 0) 2844 return ret; 2845 2846 ret = -ESRCH; 2847 task = get_proc_task(file_inode(file)); 2848 if (!task) 2849 goto out_no_task; 2850 2851 mm = get_task_mm(task); 2852 if (!mm) 2853 goto out_no_mm; 2854 ret = 0; 2855 2856 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2857 if (val & mask) 2858 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2859 else 2860 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2861 } 2862 2863 mmput(mm); 2864 out_no_mm: 2865 put_task_struct(task); 2866 out_no_task: 2867 if (ret < 0) 2868 return ret; 2869 return count; 2870 } 2871 2872 static const struct file_operations proc_coredump_filter_operations = { 2873 .read = proc_coredump_filter_read, 2874 .write = proc_coredump_filter_write, 2875 .llseek = generic_file_llseek, 2876 }; 2877 #endif 2878 2879 #ifdef CONFIG_TASK_IO_ACCOUNTING 2880 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole) 2881 { 2882 struct task_io_accounting acct = task->ioac; 2883 unsigned long flags; 2884 int result; 2885 2886 result = mutex_lock_killable(&task->signal->exec_update_mutex); 2887 if (result) 2888 return result; 2889 2890 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { 2891 result = -EACCES; 2892 goto out_unlock; 2893 } 2894 2895 if (whole && lock_task_sighand(task, &flags)) { 2896 struct task_struct *t = task; 2897 2898 task_io_accounting_add(&acct, &task->signal->ioac); 2899 while_each_thread(task, t) 2900 task_io_accounting_add(&acct, &t->ioac); 2901 2902 unlock_task_sighand(task, &flags); 2903 } 2904 seq_printf(m, 2905 "rchar: %llu\n" 2906 "wchar: %llu\n" 2907 "syscr: %llu\n" 2908 "syscw: %llu\n" 2909 "read_bytes: %llu\n" 2910 "write_bytes: %llu\n" 2911 "cancelled_write_bytes: %llu\n", 2912 (unsigned long long)acct.rchar, 2913 (unsigned long long)acct.wchar, 2914 (unsigned long long)acct.syscr, 2915 (unsigned long long)acct.syscw, 2916 (unsigned long long)acct.read_bytes, 2917 (unsigned long long)acct.write_bytes, 2918 (unsigned long long)acct.cancelled_write_bytes); 2919 result = 0; 2920 2921 out_unlock: 2922 mutex_unlock(&task->signal->exec_update_mutex); 2923 return result; 2924 } 2925 2926 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2927 struct pid *pid, struct task_struct *task) 2928 { 2929 return do_io_accounting(task, m, 0); 2930 } 2931 2932 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2933 struct pid *pid, struct task_struct *task) 2934 { 2935 return do_io_accounting(task, m, 1); 2936 } 2937 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2938 2939 #ifdef CONFIG_USER_NS 2940 static int proc_id_map_open(struct inode *inode, struct file *file, 2941 const struct seq_operations *seq_ops) 2942 { 2943 struct user_namespace *ns = NULL; 2944 struct task_struct *task; 2945 struct seq_file *seq; 2946 int ret = -EINVAL; 2947 2948 task = get_proc_task(inode); 2949 if (task) { 2950 rcu_read_lock(); 2951 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2952 rcu_read_unlock(); 2953 put_task_struct(task); 2954 } 2955 if (!ns) 2956 goto err; 2957 2958 ret = seq_open(file, seq_ops); 2959 if (ret) 2960 goto err_put_ns; 2961 2962 seq = file->private_data; 2963 seq->private = ns; 2964 2965 return 0; 2966 err_put_ns: 2967 put_user_ns(ns); 2968 err: 2969 return ret; 2970 } 2971 2972 static int proc_id_map_release(struct inode *inode, struct file *file) 2973 { 2974 struct seq_file *seq = file->private_data; 2975 struct user_namespace *ns = seq->private; 2976 put_user_ns(ns); 2977 return seq_release(inode, file); 2978 } 2979 2980 static int proc_uid_map_open(struct inode *inode, struct file *file) 2981 { 2982 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2983 } 2984 2985 static int proc_gid_map_open(struct inode *inode, struct file *file) 2986 { 2987 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2988 } 2989 2990 static int proc_projid_map_open(struct inode *inode, struct file *file) 2991 { 2992 return proc_id_map_open(inode, file, &proc_projid_seq_operations); 2993 } 2994 2995 static const struct file_operations proc_uid_map_operations = { 2996 .open = proc_uid_map_open, 2997 .write = proc_uid_map_write, 2998 .read = seq_read, 2999 .llseek = seq_lseek, 3000 .release = proc_id_map_release, 3001 }; 3002 3003 static const struct file_operations proc_gid_map_operations = { 3004 .open = proc_gid_map_open, 3005 .write = proc_gid_map_write, 3006 .read = seq_read, 3007 .llseek = seq_lseek, 3008 .release = proc_id_map_release, 3009 }; 3010 3011 static const struct file_operations proc_projid_map_operations = { 3012 .open = proc_projid_map_open, 3013 .write = proc_projid_map_write, 3014 .read = seq_read, 3015 .llseek = seq_lseek, 3016 .release = proc_id_map_release, 3017 }; 3018 3019 static int proc_setgroups_open(struct inode *inode, struct file *file) 3020 { 3021 struct user_namespace *ns = NULL; 3022 struct task_struct *task; 3023 int ret; 3024 3025 ret = -ESRCH; 3026 task = get_proc_task(inode); 3027 if (task) { 3028 rcu_read_lock(); 3029 ns = get_user_ns(task_cred_xxx(task, user_ns)); 3030 rcu_read_unlock(); 3031 put_task_struct(task); 3032 } 3033 if (!ns) 3034 goto err; 3035 3036 if (file->f_mode & FMODE_WRITE) { 3037 ret = -EACCES; 3038 if (!ns_capable(ns, CAP_SYS_ADMIN)) 3039 goto err_put_ns; 3040 } 3041 3042 ret = single_open(file, &proc_setgroups_show, ns); 3043 if (ret) 3044 goto err_put_ns; 3045 3046 return 0; 3047 err_put_ns: 3048 put_user_ns(ns); 3049 err: 3050 return ret; 3051 } 3052 3053 static int proc_setgroups_release(struct inode *inode, struct file *file) 3054 { 3055 struct seq_file *seq = file->private_data; 3056 struct user_namespace *ns = seq->private; 3057 int ret = single_release(inode, file); 3058 put_user_ns(ns); 3059 return ret; 3060 } 3061 3062 static const struct file_operations proc_setgroups_operations = { 3063 .open = proc_setgroups_open, 3064 .write = proc_setgroups_write, 3065 .read = seq_read, 3066 .llseek = seq_lseek, 3067 .release = proc_setgroups_release, 3068 }; 3069 #endif /* CONFIG_USER_NS */ 3070 3071 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 3072 struct pid *pid, struct task_struct *task) 3073 { 3074 int err = lock_trace(task); 3075 if (!err) { 3076 seq_printf(m, "%08x\n", task->personality); 3077 unlock_trace(task); 3078 } 3079 return err; 3080 } 3081 3082 #ifdef CONFIG_LIVEPATCH 3083 static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns, 3084 struct pid *pid, struct task_struct *task) 3085 { 3086 seq_printf(m, "%d\n", task->patch_state); 3087 return 0; 3088 } 3089 #endif /* CONFIG_LIVEPATCH */ 3090 3091 #ifdef CONFIG_STACKLEAK_METRICS 3092 static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns, 3093 struct pid *pid, struct task_struct *task) 3094 { 3095 unsigned long prev_depth = THREAD_SIZE - 3096 (task->prev_lowest_stack & (THREAD_SIZE - 1)); 3097 unsigned long depth = THREAD_SIZE - 3098 (task->lowest_stack & (THREAD_SIZE - 1)); 3099 3100 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n", 3101 prev_depth, depth); 3102 return 0; 3103 } 3104 #endif /* CONFIG_STACKLEAK_METRICS */ 3105 3106 /* 3107 * Thread groups 3108 */ 3109 static const struct file_operations proc_task_operations; 3110 static const struct inode_operations proc_task_inode_operations; 3111 3112 static const struct pid_entry tgid_base_stuff[] = { 3113 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 3114 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3115 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 3116 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3117 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3118 #ifdef CONFIG_NET 3119 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3120 #endif 3121 REG("environ", S_IRUSR, proc_environ_operations), 3122 REG("auxv", S_IRUSR, proc_auxv_operations), 3123 ONE("status", S_IRUGO, proc_pid_status), 3124 ONE("personality", S_IRUSR, proc_pid_personality), 3125 ONE("limits", S_IRUGO, proc_pid_limits), 3126 #ifdef CONFIG_SCHED_DEBUG 3127 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3128 #endif 3129 #ifdef CONFIG_SCHED_AUTOGROUP 3130 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 3131 #endif 3132 #ifdef CONFIG_TIME_NS 3133 REG("timens_offsets", S_IRUGO|S_IWUSR, proc_timens_offsets_operations), 3134 #endif 3135 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3136 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3137 ONE("syscall", S_IRUSR, proc_pid_syscall), 3138 #endif 3139 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 3140 ONE("stat", S_IRUGO, proc_tgid_stat), 3141 ONE("statm", S_IRUGO, proc_pid_statm), 3142 REG("maps", S_IRUGO, proc_pid_maps_operations), 3143 #ifdef CONFIG_NUMA 3144 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 3145 #endif 3146 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3147 LNK("cwd", proc_cwd_link), 3148 LNK("root", proc_root_link), 3149 LNK("exe", proc_exe_link), 3150 REG("mounts", S_IRUGO, proc_mounts_operations), 3151 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3152 REG("mountstats", S_IRUSR, proc_mountstats_operations), 3153 #ifdef CONFIG_PROC_PAGE_MONITOR 3154 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3155 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 3156 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations), 3157 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3158 #endif 3159 #ifdef CONFIG_SECURITY 3160 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3161 #endif 3162 #ifdef CONFIG_KALLSYMS 3163 ONE("wchan", S_IRUGO, proc_pid_wchan), 3164 #endif 3165 #ifdef CONFIG_STACKTRACE 3166 ONE("stack", S_IRUSR, proc_pid_stack), 3167 #endif 3168 #ifdef CONFIG_SCHED_INFO 3169 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 3170 #endif 3171 #ifdef CONFIG_LATENCYTOP 3172 REG("latency", S_IRUGO, proc_lstats_operations), 3173 #endif 3174 #ifdef CONFIG_PROC_PID_CPUSET 3175 ONE("cpuset", S_IRUGO, proc_cpuset_show), 3176 #endif 3177 #ifdef CONFIG_CGROUPS 3178 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3179 #endif 3180 #ifdef CONFIG_PROC_CPU_RESCTRL 3181 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show), 3182 #endif 3183 ONE("oom_score", S_IRUGO, proc_oom_score), 3184 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3185 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3186 #ifdef CONFIG_AUDIT 3187 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3188 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3189 #endif 3190 #ifdef CONFIG_FAULT_INJECTION 3191 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3192 REG("fail-nth", 0644, proc_fail_nth_operations), 3193 #endif 3194 #ifdef CONFIG_ELF_CORE 3195 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 3196 #endif 3197 #ifdef CONFIG_TASK_IO_ACCOUNTING 3198 ONE("io", S_IRUSR, proc_tgid_io_accounting), 3199 #endif 3200 #ifdef CONFIG_USER_NS 3201 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3202 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3203 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3204 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3205 #endif 3206 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS) 3207 REG("timers", S_IRUGO, proc_timers_operations), 3208 #endif 3209 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations), 3210 #ifdef CONFIG_LIVEPATCH 3211 ONE("patch_state", S_IRUSR, proc_pid_patch_state), 3212 #endif 3213 #ifdef CONFIG_STACKLEAK_METRICS 3214 ONE("stack_depth", S_IRUGO, proc_stack_depth), 3215 #endif 3216 #ifdef CONFIG_PROC_PID_ARCH_STATUS 3217 ONE("arch_status", S_IRUGO, proc_pid_arch_status), 3218 #endif 3219 }; 3220 3221 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) 3222 { 3223 return proc_pident_readdir(file, ctx, 3224 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3225 } 3226 3227 static const struct file_operations proc_tgid_base_operations = { 3228 .read = generic_read_dir, 3229 .iterate_shared = proc_tgid_base_readdir, 3230 .llseek = generic_file_llseek, 3231 }; 3232 3233 struct pid *tgid_pidfd_to_pid(const struct file *file) 3234 { 3235 if (file->f_op != &proc_tgid_base_operations) 3236 return ERR_PTR(-EBADF); 3237 3238 return proc_pid(file_inode(file)); 3239 } 3240 3241 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3242 { 3243 return proc_pident_lookup(dir, dentry, 3244 tgid_base_stuff, 3245 tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff)); 3246 } 3247 3248 static const struct inode_operations proc_tgid_base_inode_operations = { 3249 .lookup = proc_tgid_base_lookup, 3250 .getattr = pid_getattr, 3251 .setattr = proc_setattr, 3252 .permission = proc_pid_permission, 3253 }; 3254 3255 /** 3256 * proc_flush_pid - Remove dcache entries for @pid from the /proc dcache. 3257 * @pid: pid that should be flushed. 3258 * 3259 * This function walks a list of inodes (that belong to any proc 3260 * filesystem) that are attached to the pid and flushes them from 3261 * the dentry cache. 3262 * 3263 * It is safe and reasonable to cache /proc entries for a task until 3264 * that task exits. After that they just clog up the dcache with 3265 * useless entries, possibly causing useful dcache entries to be 3266 * flushed instead. This routine is provided to flush those useless 3267 * dcache entries when a process is reaped. 3268 * 3269 * NOTE: This routine is just an optimization so it does not guarantee 3270 * that no dcache entries will exist after a process is reaped 3271 * it just makes it very unlikely that any will persist. 3272 */ 3273 3274 void proc_flush_pid(struct pid *pid) 3275 { 3276 proc_invalidate_siblings_dcache(&pid->inodes, &pid->lock); 3277 put_pid(pid); 3278 } 3279 3280 static struct dentry *proc_pid_instantiate(struct dentry * dentry, 3281 struct task_struct *task, const void *ptr) 3282 { 3283 struct inode *inode; 3284 3285 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3286 if (!inode) 3287 return ERR_PTR(-ENOENT); 3288 3289 inode->i_op = &proc_tgid_base_inode_operations; 3290 inode->i_fop = &proc_tgid_base_operations; 3291 inode->i_flags|=S_IMMUTABLE; 3292 3293 set_nlink(inode, nlink_tgid); 3294 pid_update_inode(task, inode); 3295 3296 d_set_d_op(dentry, &pid_dentry_operations); 3297 return d_splice_alias(inode, dentry); 3298 } 3299 3300 struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags) 3301 { 3302 struct task_struct *task; 3303 unsigned tgid; 3304 struct pid_namespace *ns; 3305 struct dentry *result = ERR_PTR(-ENOENT); 3306 3307 tgid = name_to_int(&dentry->d_name); 3308 if (tgid == ~0U) 3309 goto out; 3310 3311 ns = dentry->d_sb->s_fs_info; 3312 rcu_read_lock(); 3313 task = find_task_by_pid_ns(tgid, ns); 3314 if (task) 3315 get_task_struct(task); 3316 rcu_read_unlock(); 3317 if (!task) 3318 goto out; 3319 3320 result = proc_pid_instantiate(dentry, task, NULL); 3321 put_task_struct(task); 3322 out: 3323 return result; 3324 } 3325 3326 /* 3327 * Find the first task with tgid >= tgid 3328 * 3329 */ 3330 struct tgid_iter { 3331 unsigned int tgid; 3332 struct task_struct *task; 3333 }; 3334 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3335 { 3336 struct pid *pid; 3337 3338 if (iter.task) 3339 put_task_struct(iter.task); 3340 rcu_read_lock(); 3341 retry: 3342 iter.task = NULL; 3343 pid = find_ge_pid(iter.tgid, ns); 3344 if (pid) { 3345 iter.tgid = pid_nr_ns(pid, ns); 3346 iter.task = pid_task(pid, PIDTYPE_PID); 3347 /* What we to know is if the pid we have find is the 3348 * pid of a thread_group_leader. Testing for task 3349 * being a thread_group_leader is the obvious thing 3350 * todo but there is a window when it fails, due to 3351 * the pid transfer logic in de_thread. 3352 * 3353 * So we perform the straight forward test of seeing 3354 * if the pid we have found is the pid of a thread 3355 * group leader, and don't worry if the task we have 3356 * found doesn't happen to be a thread group leader. 3357 * As we don't care in the case of readdir. 3358 */ 3359 if (!iter.task || !has_group_leader_pid(iter.task)) { 3360 iter.tgid += 1; 3361 goto retry; 3362 } 3363 get_task_struct(iter.task); 3364 } 3365 rcu_read_unlock(); 3366 return iter; 3367 } 3368 3369 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2) 3370 3371 /* for the /proc/ directory itself, after non-process stuff has been done */ 3372 int proc_pid_readdir(struct file *file, struct dir_context *ctx) 3373 { 3374 struct tgid_iter iter; 3375 struct pid_namespace *ns = proc_pid_ns(file_inode(file)); 3376 loff_t pos = ctx->pos; 3377 3378 if (pos >= PID_MAX_LIMIT + TGID_OFFSET) 3379 return 0; 3380 3381 if (pos == TGID_OFFSET - 2) { 3382 struct inode *inode = d_inode(ns->proc_self); 3383 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) 3384 return 0; 3385 ctx->pos = pos = pos + 1; 3386 } 3387 if (pos == TGID_OFFSET - 1) { 3388 struct inode *inode = d_inode(ns->proc_thread_self); 3389 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) 3390 return 0; 3391 ctx->pos = pos = pos + 1; 3392 } 3393 iter.tgid = pos - TGID_OFFSET; 3394 iter.task = NULL; 3395 for (iter = next_tgid(ns, iter); 3396 iter.task; 3397 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3398 char name[10 + 1]; 3399 unsigned int len; 3400 3401 cond_resched(); 3402 if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE)) 3403 continue; 3404 3405 len = snprintf(name, sizeof(name), "%u", iter.tgid); 3406 ctx->pos = iter.tgid + TGID_OFFSET; 3407 if (!proc_fill_cache(file, ctx, name, len, 3408 proc_pid_instantiate, iter.task, NULL)) { 3409 put_task_struct(iter.task); 3410 return 0; 3411 } 3412 } 3413 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET; 3414 return 0; 3415 } 3416 3417 /* 3418 * proc_tid_comm_permission is a special permission function exclusively 3419 * used for the node /proc/<pid>/task/<tid>/comm. 3420 * It bypasses generic permission checks in the case where a task of the same 3421 * task group attempts to access the node. 3422 * The rationale behind this is that glibc and bionic access this node for 3423 * cross thread naming (pthread_set/getname_np(!self)). However, if 3424 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0, 3425 * which locks out the cross thread naming implementation. 3426 * This function makes sure that the node is always accessible for members of 3427 * same thread group. 3428 */ 3429 static int proc_tid_comm_permission(struct inode *inode, int mask) 3430 { 3431 bool is_same_tgroup; 3432 struct task_struct *task; 3433 3434 task = get_proc_task(inode); 3435 if (!task) 3436 return -ESRCH; 3437 is_same_tgroup = same_thread_group(current, task); 3438 put_task_struct(task); 3439 3440 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) { 3441 /* This file (/proc/<pid>/task/<tid>/comm) can always be 3442 * read or written by the members of the corresponding 3443 * thread group. 3444 */ 3445 return 0; 3446 } 3447 3448 return generic_permission(inode, mask); 3449 } 3450 3451 static const struct inode_operations proc_tid_comm_inode_operations = { 3452 .permission = proc_tid_comm_permission, 3453 }; 3454 3455 /* 3456 * Tasks 3457 */ 3458 static const struct pid_entry tid_base_stuff[] = { 3459 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3460 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3461 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3462 #ifdef CONFIG_NET 3463 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3464 #endif 3465 REG("environ", S_IRUSR, proc_environ_operations), 3466 REG("auxv", S_IRUSR, proc_auxv_operations), 3467 ONE("status", S_IRUGO, proc_pid_status), 3468 ONE("personality", S_IRUSR, proc_pid_personality), 3469 ONE("limits", S_IRUGO, proc_pid_limits), 3470 #ifdef CONFIG_SCHED_DEBUG 3471 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3472 #endif 3473 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR, 3474 &proc_tid_comm_inode_operations, 3475 &proc_pid_set_comm_operations, {}), 3476 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3477 ONE("syscall", S_IRUSR, proc_pid_syscall), 3478 #endif 3479 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), 3480 ONE("stat", S_IRUGO, proc_tid_stat), 3481 ONE("statm", S_IRUGO, proc_pid_statm), 3482 REG("maps", S_IRUGO, proc_pid_maps_operations), 3483 #ifdef CONFIG_PROC_CHILDREN 3484 REG("children", S_IRUGO, proc_tid_children_operations), 3485 #endif 3486 #ifdef CONFIG_NUMA 3487 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 3488 #endif 3489 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3490 LNK("cwd", proc_cwd_link), 3491 LNK("root", proc_root_link), 3492 LNK("exe", proc_exe_link), 3493 REG("mounts", S_IRUGO, proc_mounts_operations), 3494 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3495 #ifdef CONFIG_PROC_PAGE_MONITOR 3496 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3497 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 3498 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations), 3499 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3500 #endif 3501 #ifdef CONFIG_SECURITY 3502 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3503 #endif 3504 #ifdef CONFIG_KALLSYMS 3505 ONE("wchan", S_IRUGO, proc_pid_wchan), 3506 #endif 3507 #ifdef CONFIG_STACKTRACE 3508 ONE("stack", S_IRUSR, proc_pid_stack), 3509 #endif 3510 #ifdef CONFIG_SCHED_INFO 3511 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 3512 #endif 3513 #ifdef CONFIG_LATENCYTOP 3514 REG("latency", S_IRUGO, proc_lstats_operations), 3515 #endif 3516 #ifdef CONFIG_PROC_PID_CPUSET 3517 ONE("cpuset", S_IRUGO, proc_cpuset_show), 3518 #endif 3519 #ifdef CONFIG_CGROUPS 3520 ONE("cgroup", S_IRUGO, proc_cgroup_show), 3521 #endif 3522 #ifdef CONFIG_PROC_CPU_RESCTRL 3523 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show), 3524 #endif 3525 ONE("oom_score", S_IRUGO, proc_oom_score), 3526 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 3527 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3528 #ifdef CONFIG_AUDIT 3529 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3530 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3531 #endif 3532 #ifdef CONFIG_FAULT_INJECTION 3533 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3534 REG("fail-nth", 0644, proc_fail_nth_operations), 3535 #endif 3536 #ifdef CONFIG_TASK_IO_ACCOUNTING 3537 ONE("io", S_IRUSR, proc_tid_io_accounting), 3538 #endif 3539 #ifdef CONFIG_USER_NS 3540 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3541 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3542 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3543 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), 3544 #endif 3545 #ifdef CONFIG_LIVEPATCH 3546 ONE("patch_state", S_IRUSR, proc_pid_patch_state), 3547 #endif 3548 #ifdef CONFIG_PROC_PID_ARCH_STATUS 3549 ONE("arch_status", S_IRUGO, proc_pid_arch_status), 3550 #endif 3551 }; 3552 3553 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx) 3554 { 3555 return proc_pident_readdir(file, ctx, 3556 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3557 } 3558 3559 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3560 { 3561 return proc_pident_lookup(dir, dentry, 3562 tid_base_stuff, 3563 tid_base_stuff + ARRAY_SIZE(tid_base_stuff)); 3564 } 3565 3566 static const struct file_operations proc_tid_base_operations = { 3567 .read = generic_read_dir, 3568 .iterate_shared = proc_tid_base_readdir, 3569 .llseek = generic_file_llseek, 3570 }; 3571 3572 static const struct inode_operations proc_tid_base_inode_operations = { 3573 .lookup = proc_tid_base_lookup, 3574 .getattr = pid_getattr, 3575 .setattr = proc_setattr, 3576 }; 3577 3578 static struct dentry *proc_task_instantiate(struct dentry *dentry, 3579 struct task_struct *task, const void *ptr) 3580 { 3581 struct inode *inode; 3582 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO); 3583 if (!inode) 3584 return ERR_PTR(-ENOENT); 3585 3586 inode->i_op = &proc_tid_base_inode_operations; 3587 inode->i_fop = &proc_tid_base_operations; 3588 inode->i_flags |= S_IMMUTABLE; 3589 3590 set_nlink(inode, nlink_tid); 3591 pid_update_inode(task, inode); 3592 3593 d_set_d_op(dentry, &pid_dentry_operations); 3594 return d_splice_alias(inode, dentry); 3595 } 3596 3597 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3598 { 3599 struct task_struct *task; 3600 struct task_struct *leader = get_proc_task(dir); 3601 unsigned tid; 3602 struct pid_namespace *ns; 3603 struct dentry *result = ERR_PTR(-ENOENT); 3604 3605 if (!leader) 3606 goto out_no_task; 3607 3608 tid = name_to_int(&dentry->d_name); 3609 if (tid == ~0U) 3610 goto out; 3611 3612 ns = dentry->d_sb->s_fs_info; 3613 rcu_read_lock(); 3614 task = find_task_by_pid_ns(tid, ns); 3615 if (task) 3616 get_task_struct(task); 3617 rcu_read_unlock(); 3618 if (!task) 3619 goto out; 3620 if (!same_thread_group(leader, task)) 3621 goto out_drop_task; 3622 3623 result = proc_task_instantiate(dentry, task, NULL); 3624 out_drop_task: 3625 put_task_struct(task); 3626 out: 3627 put_task_struct(leader); 3628 out_no_task: 3629 return result; 3630 } 3631 3632 /* 3633 * Find the first tid of a thread group to return to user space. 3634 * 3635 * Usually this is just the thread group leader, but if the users 3636 * buffer was too small or there was a seek into the middle of the 3637 * directory we have more work todo. 3638 * 3639 * In the case of a short read we start with find_task_by_pid. 3640 * 3641 * In the case of a seek we start with the leader and walk nr 3642 * threads past it. 3643 */ 3644 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos, 3645 struct pid_namespace *ns) 3646 { 3647 struct task_struct *pos, *task; 3648 unsigned long nr = f_pos; 3649 3650 if (nr != f_pos) /* 32bit overflow? */ 3651 return NULL; 3652 3653 rcu_read_lock(); 3654 task = pid_task(pid, PIDTYPE_PID); 3655 if (!task) 3656 goto fail; 3657 3658 /* Attempt to start with the tid of a thread */ 3659 if (tid && nr) { 3660 pos = find_task_by_pid_ns(tid, ns); 3661 if (pos && same_thread_group(pos, task)) 3662 goto found; 3663 } 3664 3665 /* If nr exceeds the number of threads there is nothing todo */ 3666 if (nr >= get_nr_threads(task)) 3667 goto fail; 3668 3669 /* If we haven't found our starting place yet start 3670 * with the leader and walk nr threads forward. 3671 */ 3672 pos = task = task->group_leader; 3673 do { 3674 if (!nr--) 3675 goto found; 3676 } while_each_thread(task, pos); 3677 fail: 3678 pos = NULL; 3679 goto out; 3680 found: 3681 get_task_struct(pos); 3682 out: 3683 rcu_read_unlock(); 3684 return pos; 3685 } 3686 3687 /* 3688 * Find the next thread in the thread list. 3689 * Return NULL if there is an error or no next thread. 3690 * 3691 * The reference to the input task_struct is released. 3692 */ 3693 static struct task_struct *next_tid(struct task_struct *start) 3694 { 3695 struct task_struct *pos = NULL; 3696 rcu_read_lock(); 3697 if (pid_alive(start)) { 3698 pos = next_thread(start); 3699 if (thread_group_leader(pos)) 3700 pos = NULL; 3701 else 3702 get_task_struct(pos); 3703 } 3704 rcu_read_unlock(); 3705 put_task_struct(start); 3706 return pos; 3707 } 3708 3709 /* for the /proc/TGID/task/ directories */ 3710 static int proc_task_readdir(struct file *file, struct dir_context *ctx) 3711 { 3712 struct inode *inode = file_inode(file); 3713 struct task_struct *task; 3714 struct pid_namespace *ns; 3715 int tid; 3716 3717 if (proc_inode_is_dead(inode)) 3718 return -ENOENT; 3719 3720 if (!dir_emit_dots(file, ctx)) 3721 return 0; 3722 3723 /* f_version caches the tgid value that the last readdir call couldn't 3724 * return. lseek aka telldir automagically resets f_version to 0. 3725 */ 3726 ns = proc_pid_ns(inode); 3727 tid = (int)file->f_version; 3728 file->f_version = 0; 3729 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); 3730 task; 3731 task = next_tid(task), ctx->pos++) { 3732 char name[10 + 1]; 3733 unsigned int len; 3734 tid = task_pid_nr_ns(task, ns); 3735 len = snprintf(name, sizeof(name), "%u", tid); 3736 if (!proc_fill_cache(file, ctx, name, len, 3737 proc_task_instantiate, task, NULL)) { 3738 /* returning this tgid failed, save it as the first 3739 * pid for the next readir call */ 3740 file->f_version = (u64)tid; 3741 put_task_struct(task); 3742 break; 3743 } 3744 } 3745 3746 return 0; 3747 } 3748 3749 static int proc_task_getattr(const struct path *path, struct kstat *stat, 3750 u32 request_mask, unsigned int query_flags) 3751 { 3752 struct inode *inode = d_inode(path->dentry); 3753 struct task_struct *p = get_proc_task(inode); 3754 generic_fillattr(inode, stat); 3755 3756 if (p) { 3757 stat->nlink += get_nr_threads(p); 3758 put_task_struct(p); 3759 } 3760 3761 return 0; 3762 } 3763 3764 static const struct inode_operations proc_task_inode_operations = { 3765 .lookup = proc_task_lookup, 3766 .getattr = proc_task_getattr, 3767 .setattr = proc_setattr, 3768 .permission = proc_pid_permission, 3769 }; 3770 3771 static const struct file_operations proc_task_operations = { 3772 .read = generic_read_dir, 3773 .iterate_shared = proc_task_readdir, 3774 .llseek = generic_file_llseek, 3775 }; 3776 3777 void __init set_proc_pid_nlink(void) 3778 { 3779 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3780 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3781 } 3782