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