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