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_CGROUPS 380 static int cgroup_open(struct inode *inode, struct file *file) 381 { 382 struct pid *pid = PROC_I(inode)->pid; 383 return single_open(file, proc_cgroup_show, pid); 384 } 385 386 static const struct file_operations proc_cgroup_operations = { 387 .open = cgroup_open, 388 .read = seq_read, 389 .llseek = seq_lseek, 390 .release = single_release, 391 }; 392 #endif 393 394 #ifdef CONFIG_PROC_PID_CPUSET 395 396 static int cpuset_open(struct inode *inode, struct file *file) 397 { 398 struct pid *pid = PROC_I(inode)->pid; 399 return single_open(file, proc_cpuset_show, pid); 400 } 401 402 static const struct file_operations proc_cpuset_operations = { 403 .open = cpuset_open, 404 .read = seq_read, 405 .llseek = seq_lseek, 406 .release = single_release, 407 }; 408 #endif 409 410 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns, 411 struct pid *pid, struct task_struct *task) 412 { 413 unsigned long totalpages = totalram_pages + total_swap_pages; 414 unsigned long points = 0; 415 416 read_lock(&tasklist_lock); 417 if (pid_alive(task)) 418 points = oom_badness(task, NULL, NULL, totalpages) * 419 1000 / totalpages; 420 read_unlock(&tasklist_lock); 421 return seq_printf(m, "%lu\n", points); 422 } 423 424 struct limit_names { 425 const char *name; 426 const char *unit; 427 }; 428 429 static const struct limit_names lnames[RLIM_NLIMITS] = { 430 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 431 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 432 [RLIMIT_DATA] = {"Max data size", "bytes"}, 433 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 434 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 435 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 436 [RLIMIT_NPROC] = {"Max processes", "processes"}, 437 [RLIMIT_NOFILE] = {"Max open files", "files"}, 438 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 439 [RLIMIT_AS] = {"Max address space", "bytes"}, 440 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 441 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 442 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 443 [RLIMIT_NICE] = {"Max nice priority", NULL}, 444 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 445 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 446 }; 447 448 /* Display limits for a process */ 449 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns, 450 struct pid *pid, struct task_struct *task) 451 { 452 unsigned int i; 453 unsigned long flags; 454 455 struct rlimit rlim[RLIM_NLIMITS]; 456 457 if (!lock_task_sighand(task, &flags)) 458 return 0; 459 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 460 unlock_task_sighand(task, &flags); 461 462 /* 463 * print the file header 464 */ 465 seq_printf(m, "%-25s %-20s %-20s %-10s\n", 466 "Limit", "Soft Limit", "Hard Limit", "Units"); 467 468 for (i = 0; i < RLIM_NLIMITS; i++) { 469 if (rlim[i].rlim_cur == RLIM_INFINITY) 470 seq_printf(m, "%-25s %-20s ", 471 lnames[i].name, "unlimited"); 472 else 473 seq_printf(m, "%-25s %-20lu ", 474 lnames[i].name, rlim[i].rlim_cur); 475 476 if (rlim[i].rlim_max == RLIM_INFINITY) 477 seq_printf(m, "%-20s ", "unlimited"); 478 else 479 seq_printf(m, "%-20lu ", rlim[i].rlim_max); 480 481 if (lnames[i].unit) 482 seq_printf(m, "%-10s\n", lnames[i].unit); 483 else 484 seq_putc(m, '\n'); 485 } 486 487 return 0; 488 } 489 490 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 491 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns, 492 struct pid *pid, struct task_struct *task) 493 { 494 long nr; 495 unsigned long args[6], sp, pc; 496 int res = lock_trace(task); 497 if (res) 498 return res; 499 500 if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) 501 seq_puts(m, "running\n"); 502 else if (nr < 0) 503 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc); 504 else 505 seq_printf(m, 506 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", 507 nr, 508 args[0], args[1], args[2], args[3], args[4], args[5], 509 sp, pc); 510 unlock_trace(task); 511 return res; 512 } 513 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 514 515 /************************************************************************/ 516 /* Here the fs part begins */ 517 /************************************************************************/ 518 519 /* permission checks */ 520 static int proc_fd_access_allowed(struct inode *inode) 521 { 522 struct task_struct *task; 523 int allowed = 0; 524 /* Allow access to a task's file descriptors if it is us or we 525 * may use ptrace attach to the process and find out that 526 * information. 527 */ 528 task = get_proc_task(inode); 529 if (task) { 530 allowed = ptrace_may_access(task, PTRACE_MODE_READ); 531 put_task_struct(task); 532 } 533 return allowed; 534 } 535 536 int proc_setattr(struct dentry *dentry, struct iattr *attr) 537 { 538 int error; 539 struct inode *inode = dentry->d_inode; 540 541 if (attr->ia_valid & ATTR_MODE) 542 return -EPERM; 543 544 error = inode_change_ok(inode, attr); 545 if (error) 546 return error; 547 548 setattr_copy(inode, attr); 549 mark_inode_dirty(inode); 550 return 0; 551 } 552 553 /* 554 * May current process learn task's sched/cmdline info (for hide_pid_min=1) 555 * or euid/egid (for hide_pid_min=2)? 556 */ 557 static bool has_pid_permissions(struct pid_namespace *pid, 558 struct task_struct *task, 559 int hide_pid_min) 560 { 561 if (pid->hide_pid < hide_pid_min) 562 return true; 563 if (in_group_p(pid->pid_gid)) 564 return true; 565 return ptrace_may_access(task, PTRACE_MODE_READ); 566 } 567 568 569 static int proc_pid_permission(struct inode *inode, int mask) 570 { 571 struct pid_namespace *pid = inode->i_sb->s_fs_info; 572 struct task_struct *task; 573 bool has_perms; 574 575 task = get_proc_task(inode); 576 if (!task) 577 return -ESRCH; 578 has_perms = has_pid_permissions(pid, task, 1); 579 put_task_struct(task); 580 581 if (!has_perms) { 582 if (pid->hide_pid == 2) { 583 /* 584 * Let's make getdents(), stat(), and open() 585 * consistent with each other. If a process 586 * may not stat() a file, it shouldn't be seen 587 * in procfs at all. 588 */ 589 return -ENOENT; 590 } 591 592 return -EPERM; 593 } 594 return generic_permission(inode, mask); 595 } 596 597 598 599 static const struct inode_operations proc_def_inode_operations = { 600 .setattr = proc_setattr, 601 }; 602 603 static int proc_single_show(struct seq_file *m, void *v) 604 { 605 struct inode *inode = m->private; 606 struct pid_namespace *ns; 607 struct pid *pid; 608 struct task_struct *task; 609 int ret; 610 611 ns = inode->i_sb->s_fs_info; 612 pid = proc_pid(inode); 613 task = get_pid_task(pid, PIDTYPE_PID); 614 if (!task) 615 return -ESRCH; 616 617 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 618 619 put_task_struct(task); 620 return ret; 621 } 622 623 static int proc_single_open(struct inode *inode, struct file *filp) 624 { 625 return single_open(filp, proc_single_show, inode); 626 } 627 628 static const struct file_operations proc_single_file_operations = { 629 .open = proc_single_open, 630 .read = seq_read, 631 .llseek = seq_lseek, 632 .release = single_release, 633 }; 634 635 636 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode) 637 { 638 struct task_struct *task = get_proc_task(inode); 639 struct mm_struct *mm = ERR_PTR(-ESRCH); 640 641 if (task) { 642 mm = mm_access(task, mode); 643 put_task_struct(task); 644 645 if (!IS_ERR_OR_NULL(mm)) { 646 /* ensure this mm_struct can't be freed */ 647 atomic_inc(&mm->mm_count); 648 /* but do not pin its memory */ 649 mmput(mm); 650 } 651 } 652 653 return mm; 654 } 655 656 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) 657 { 658 struct mm_struct *mm = proc_mem_open(inode, mode); 659 660 if (IS_ERR(mm)) 661 return PTR_ERR(mm); 662 663 file->private_data = mm; 664 return 0; 665 } 666 667 static int mem_open(struct inode *inode, struct file *file) 668 { 669 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH); 670 671 /* OK to pass negative loff_t, we can catch out-of-range */ 672 file->f_mode |= FMODE_UNSIGNED_OFFSET; 673 674 return ret; 675 } 676 677 static ssize_t mem_rw(struct file *file, char __user *buf, 678 size_t count, loff_t *ppos, int write) 679 { 680 struct mm_struct *mm = file->private_data; 681 unsigned long addr = *ppos; 682 ssize_t copied; 683 char *page; 684 685 if (!mm) 686 return 0; 687 688 page = (char *)__get_free_page(GFP_TEMPORARY); 689 if (!page) 690 return -ENOMEM; 691 692 copied = 0; 693 if (!atomic_inc_not_zero(&mm->mm_users)) 694 goto free; 695 696 while (count > 0) { 697 int this_len = min_t(int, count, PAGE_SIZE); 698 699 if (write && copy_from_user(page, buf, this_len)) { 700 copied = -EFAULT; 701 break; 702 } 703 704 this_len = access_remote_vm(mm, addr, page, this_len, write); 705 if (!this_len) { 706 if (!copied) 707 copied = -EIO; 708 break; 709 } 710 711 if (!write && copy_to_user(buf, page, this_len)) { 712 copied = -EFAULT; 713 break; 714 } 715 716 buf += this_len; 717 addr += this_len; 718 copied += this_len; 719 count -= this_len; 720 } 721 *ppos = addr; 722 723 mmput(mm); 724 free: 725 free_page((unsigned long) page); 726 return copied; 727 } 728 729 static ssize_t mem_read(struct file *file, char __user *buf, 730 size_t count, loff_t *ppos) 731 { 732 return mem_rw(file, buf, count, ppos, 0); 733 } 734 735 static ssize_t mem_write(struct file *file, const char __user *buf, 736 size_t count, loff_t *ppos) 737 { 738 return mem_rw(file, (char __user*)buf, count, ppos, 1); 739 } 740 741 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 742 { 743 switch (orig) { 744 case 0: 745 file->f_pos = offset; 746 break; 747 case 1: 748 file->f_pos += offset; 749 break; 750 default: 751 return -EINVAL; 752 } 753 force_successful_syscall_return(); 754 return file->f_pos; 755 } 756 757 static int mem_release(struct inode *inode, struct file *file) 758 { 759 struct mm_struct *mm = file->private_data; 760 if (mm) 761 mmdrop(mm); 762 return 0; 763 } 764 765 static const struct file_operations proc_mem_operations = { 766 .llseek = mem_lseek, 767 .read = mem_read, 768 .write = mem_write, 769 .open = mem_open, 770 .release = mem_release, 771 }; 772 773 static int environ_open(struct inode *inode, struct file *file) 774 { 775 return __mem_open(inode, file, PTRACE_MODE_READ); 776 } 777 778 static ssize_t environ_read(struct file *file, char __user *buf, 779 size_t count, loff_t *ppos) 780 { 781 char *page; 782 unsigned long src = *ppos; 783 int ret = 0; 784 struct mm_struct *mm = file->private_data; 785 786 if (!mm) 787 return 0; 788 789 page = (char *)__get_free_page(GFP_TEMPORARY); 790 if (!page) 791 return -ENOMEM; 792 793 ret = 0; 794 if (!atomic_inc_not_zero(&mm->mm_users)) 795 goto free; 796 while (count > 0) { 797 size_t this_len, max_len; 798 int retval; 799 800 if (src >= (mm->env_end - mm->env_start)) 801 break; 802 803 this_len = mm->env_end - (mm->env_start + src); 804 805 max_len = min_t(size_t, PAGE_SIZE, count); 806 this_len = min(max_len, this_len); 807 808 retval = access_remote_vm(mm, (mm->env_start + src), 809 page, this_len, 0); 810 811 if (retval <= 0) { 812 ret = retval; 813 break; 814 } 815 816 if (copy_to_user(buf, page, retval)) { 817 ret = -EFAULT; 818 break; 819 } 820 821 ret += retval; 822 src += retval; 823 buf += retval; 824 count -= retval; 825 } 826 *ppos = src; 827 mmput(mm); 828 829 free: 830 free_page((unsigned long) page); 831 return ret; 832 } 833 834 static const struct file_operations proc_environ_operations = { 835 .open = environ_open, 836 .read = environ_read, 837 .llseek = generic_file_llseek, 838 .release = mem_release, 839 }; 840 841 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count, 842 loff_t *ppos) 843 { 844 struct task_struct *task = get_proc_task(file_inode(file)); 845 char buffer[PROC_NUMBUF]; 846 int oom_adj = OOM_ADJUST_MIN; 847 size_t len; 848 unsigned long flags; 849 850 if (!task) 851 return -ESRCH; 852 if (lock_task_sighand(task, &flags)) { 853 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX) 854 oom_adj = OOM_ADJUST_MAX; 855 else 856 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) / 857 OOM_SCORE_ADJ_MAX; 858 unlock_task_sighand(task, &flags); 859 } 860 put_task_struct(task); 861 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj); 862 return simple_read_from_buffer(buf, count, ppos, buffer, len); 863 } 864 865 static ssize_t oom_adj_write(struct file *file, const char __user *buf, 866 size_t count, loff_t *ppos) 867 { 868 struct task_struct *task; 869 char buffer[PROC_NUMBUF]; 870 int oom_adj; 871 unsigned long flags; 872 int err; 873 874 memset(buffer, 0, sizeof(buffer)); 875 if (count > sizeof(buffer) - 1) 876 count = sizeof(buffer) - 1; 877 if (copy_from_user(buffer, buf, count)) { 878 err = -EFAULT; 879 goto out; 880 } 881 882 err = kstrtoint(strstrip(buffer), 0, &oom_adj); 883 if (err) 884 goto out; 885 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) && 886 oom_adj != OOM_DISABLE) { 887 err = -EINVAL; 888 goto out; 889 } 890 891 task = get_proc_task(file_inode(file)); 892 if (!task) { 893 err = -ESRCH; 894 goto out; 895 } 896 897 task_lock(task); 898 if (!task->mm) { 899 err = -EINVAL; 900 goto err_task_lock; 901 } 902 903 if (!lock_task_sighand(task, &flags)) { 904 err = -ESRCH; 905 goto err_task_lock; 906 } 907 908 /* 909 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 910 * value is always attainable. 911 */ 912 if (oom_adj == OOM_ADJUST_MAX) 913 oom_adj = OOM_SCORE_ADJ_MAX; 914 else 915 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE; 916 917 if (oom_adj < task->signal->oom_score_adj && 918 !capable(CAP_SYS_RESOURCE)) { 919 err = -EACCES; 920 goto err_sighand; 921 } 922 923 /* 924 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use 925 * /proc/pid/oom_score_adj instead. 926 */ 927 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 928 current->comm, task_pid_nr(current), task_pid_nr(task), 929 task_pid_nr(task)); 930 931 task->signal->oom_score_adj = oom_adj; 932 trace_oom_score_adj_update(task); 933 err_sighand: 934 unlock_task_sighand(task, &flags); 935 err_task_lock: 936 task_unlock(task); 937 put_task_struct(task); 938 out: 939 return err < 0 ? err : count; 940 } 941 942 static const struct file_operations proc_oom_adj_operations = { 943 .read = oom_adj_read, 944 .write = oom_adj_write, 945 .llseek = generic_file_llseek, 946 }; 947 948 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 949 size_t count, loff_t *ppos) 950 { 951 struct task_struct *task = get_proc_task(file_inode(file)); 952 char buffer[PROC_NUMBUF]; 953 short oom_score_adj = OOM_SCORE_ADJ_MIN; 954 unsigned long flags; 955 size_t len; 956 957 if (!task) 958 return -ESRCH; 959 if (lock_task_sighand(task, &flags)) { 960 oom_score_adj = task->signal->oom_score_adj; 961 unlock_task_sighand(task, &flags); 962 } 963 put_task_struct(task); 964 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj); 965 return simple_read_from_buffer(buf, count, ppos, buffer, len); 966 } 967 968 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 969 size_t count, loff_t *ppos) 970 { 971 struct task_struct *task; 972 char buffer[PROC_NUMBUF]; 973 unsigned long flags; 974 int oom_score_adj; 975 int err; 976 977 memset(buffer, 0, sizeof(buffer)); 978 if (count > sizeof(buffer) - 1) 979 count = sizeof(buffer) - 1; 980 if (copy_from_user(buffer, buf, count)) { 981 err = -EFAULT; 982 goto out; 983 } 984 985 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 986 if (err) 987 goto out; 988 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 989 oom_score_adj > OOM_SCORE_ADJ_MAX) { 990 err = -EINVAL; 991 goto out; 992 } 993 994 task = get_proc_task(file_inode(file)); 995 if (!task) { 996 err = -ESRCH; 997 goto out; 998 } 999 1000 task_lock(task); 1001 if (!task->mm) { 1002 err = -EINVAL; 1003 goto err_task_lock; 1004 } 1005 1006 if (!lock_task_sighand(task, &flags)) { 1007 err = -ESRCH; 1008 goto err_task_lock; 1009 } 1010 1011 if ((short)oom_score_adj < task->signal->oom_score_adj_min && 1012 !capable(CAP_SYS_RESOURCE)) { 1013 err = -EACCES; 1014 goto err_sighand; 1015 } 1016 1017 task->signal->oom_score_adj = (short)oom_score_adj; 1018 if (has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1019 task->signal->oom_score_adj_min = (short)oom_score_adj; 1020 trace_oom_score_adj_update(task); 1021 1022 err_sighand: 1023 unlock_task_sighand(task, &flags); 1024 err_task_lock: 1025 task_unlock(task); 1026 put_task_struct(task); 1027 out: 1028 return err < 0 ? err : count; 1029 } 1030 1031 static const struct file_operations proc_oom_score_adj_operations = { 1032 .read = oom_score_adj_read, 1033 .write = oom_score_adj_write, 1034 .llseek = default_llseek, 1035 }; 1036 1037 #ifdef CONFIG_AUDITSYSCALL 1038 #define TMPBUFLEN 21 1039 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1040 size_t count, loff_t *ppos) 1041 { 1042 struct inode * inode = file_inode(file); 1043 struct task_struct *task = get_proc_task(inode); 1044 ssize_t length; 1045 char tmpbuf[TMPBUFLEN]; 1046 1047 if (!task) 1048 return -ESRCH; 1049 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1050 from_kuid(file->f_cred->user_ns, 1051 audit_get_loginuid(task))); 1052 put_task_struct(task); 1053 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1054 } 1055 1056 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1057 size_t count, loff_t *ppos) 1058 { 1059 struct inode * inode = file_inode(file); 1060 char *page, *tmp; 1061 ssize_t length; 1062 uid_t loginuid; 1063 kuid_t kloginuid; 1064 1065 rcu_read_lock(); 1066 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1067 rcu_read_unlock(); 1068 return -EPERM; 1069 } 1070 rcu_read_unlock(); 1071 1072 if (count >= PAGE_SIZE) 1073 count = PAGE_SIZE - 1; 1074 1075 if (*ppos != 0) { 1076 /* No partial writes. */ 1077 return -EINVAL; 1078 } 1079 page = (char*)__get_free_page(GFP_TEMPORARY); 1080 if (!page) 1081 return -ENOMEM; 1082 length = -EFAULT; 1083 if (copy_from_user(page, buf, count)) 1084 goto out_free_page; 1085 1086 page[count] = '\0'; 1087 loginuid = simple_strtoul(page, &tmp, 10); 1088 if (tmp == page) { 1089 length = -EINVAL; 1090 goto out_free_page; 1091 1092 } 1093 1094 /* is userspace tring to explicitly UNSET the loginuid? */ 1095 if (loginuid == AUDIT_UID_UNSET) { 1096 kloginuid = INVALID_UID; 1097 } else { 1098 kloginuid = make_kuid(file->f_cred->user_ns, loginuid); 1099 if (!uid_valid(kloginuid)) { 1100 length = -EINVAL; 1101 goto out_free_page; 1102 } 1103 } 1104 1105 length = audit_set_loginuid(kloginuid); 1106 if (likely(length == 0)) 1107 length = count; 1108 1109 out_free_page: 1110 free_page((unsigned long) page); 1111 return length; 1112 } 1113 1114 static const struct file_operations proc_loginuid_operations = { 1115 .read = proc_loginuid_read, 1116 .write = proc_loginuid_write, 1117 .llseek = generic_file_llseek, 1118 }; 1119 1120 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1121 size_t count, loff_t *ppos) 1122 { 1123 struct inode * inode = file_inode(file); 1124 struct task_struct *task = get_proc_task(inode); 1125 ssize_t length; 1126 char tmpbuf[TMPBUFLEN]; 1127 1128 if (!task) 1129 return -ESRCH; 1130 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1131 audit_get_sessionid(task)); 1132 put_task_struct(task); 1133 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1134 } 1135 1136 static const struct file_operations proc_sessionid_operations = { 1137 .read = proc_sessionid_read, 1138 .llseek = generic_file_llseek, 1139 }; 1140 #endif 1141 1142 #ifdef CONFIG_FAULT_INJECTION 1143 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1144 size_t count, loff_t *ppos) 1145 { 1146 struct task_struct *task = get_proc_task(file_inode(file)); 1147 char buffer[PROC_NUMBUF]; 1148 size_t len; 1149 int make_it_fail; 1150 1151 if (!task) 1152 return -ESRCH; 1153 make_it_fail = task->make_it_fail; 1154 put_task_struct(task); 1155 1156 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1157 1158 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1159 } 1160 1161 static ssize_t proc_fault_inject_write(struct file * file, 1162 const char __user * buf, size_t count, loff_t *ppos) 1163 { 1164 struct task_struct *task; 1165 char buffer[PROC_NUMBUF], *end; 1166 int make_it_fail; 1167 1168 if (!capable(CAP_SYS_RESOURCE)) 1169 return -EPERM; 1170 memset(buffer, 0, sizeof(buffer)); 1171 if (count > sizeof(buffer) - 1) 1172 count = sizeof(buffer) - 1; 1173 if (copy_from_user(buffer, buf, count)) 1174 return -EFAULT; 1175 make_it_fail = simple_strtol(strstrip(buffer), &end, 0); 1176 if (*end) 1177 return -EINVAL; 1178 if (make_it_fail < 0 || make_it_fail > 1) 1179 return -EINVAL; 1180 1181 task = get_proc_task(file_inode(file)); 1182 if (!task) 1183 return -ESRCH; 1184 task->make_it_fail = make_it_fail; 1185 put_task_struct(task); 1186 1187 return count; 1188 } 1189 1190 static const struct file_operations proc_fault_inject_operations = { 1191 .read = proc_fault_inject_read, 1192 .write = proc_fault_inject_write, 1193 .llseek = generic_file_llseek, 1194 }; 1195 #endif 1196 1197 1198 #ifdef CONFIG_SCHED_DEBUG 1199 /* 1200 * Print out various scheduling related per-task fields: 1201 */ 1202 static int sched_show(struct seq_file *m, void *v) 1203 { 1204 struct inode *inode = m->private; 1205 struct task_struct *p; 1206 1207 p = get_proc_task(inode); 1208 if (!p) 1209 return -ESRCH; 1210 proc_sched_show_task(p, m); 1211 1212 put_task_struct(p); 1213 1214 return 0; 1215 } 1216 1217 static ssize_t 1218 sched_write(struct file *file, const char __user *buf, 1219 size_t count, loff_t *offset) 1220 { 1221 struct inode *inode = file_inode(file); 1222 struct task_struct *p; 1223 1224 p = get_proc_task(inode); 1225 if (!p) 1226 return -ESRCH; 1227 proc_sched_set_task(p); 1228 1229 put_task_struct(p); 1230 1231 return count; 1232 } 1233 1234 static int sched_open(struct inode *inode, struct file *filp) 1235 { 1236 return single_open(filp, sched_show, inode); 1237 } 1238 1239 static const struct file_operations proc_pid_sched_operations = { 1240 .open = sched_open, 1241 .read = seq_read, 1242 .write = sched_write, 1243 .llseek = seq_lseek, 1244 .release = single_release, 1245 }; 1246 1247 #endif 1248 1249 #ifdef CONFIG_SCHED_AUTOGROUP 1250 /* 1251 * Print out autogroup related information: 1252 */ 1253 static int sched_autogroup_show(struct seq_file *m, void *v) 1254 { 1255 struct inode *inode = m->private; 1256 struct task_struct *p; 1257 1258 p = get_proc_task(inode); 1259 if (!p) 1260 return -ESRCH; 1261 proc_sched_autogroup_show_task(p, m); 1262 1263 put_task_struct(p); 1264 1265 return 0; 1266 } 1267 1268 static ssize_t 1269 sched_autogroup_write(struct file *file, const char __user *buf, 1270 size_t count, loff_t *offset) 1271 { 1272 struct inode *inode = file_inode(file); 1273 struct task_struct *p; 1274 char buffer[PROC_NUMBUF]; 1275 int nice; 1276 int err; 1277 1278 memset(buffer, 0, sizeof(buffer)); 1279 if (count > sizeof(buffer) - 1) 1280 count = sizeof(buffer) - 1; 1281 if (copy_from_user(buffer, buf, count)) 1282 return -EFAULT; 1283 1284 err = kstrtoint(strstrip(buffer), 0, &nice); 1285 if (err < 0) 1286 return err; 1287 1288 p = get_proc_task(inode); 1289 if (!p) 1290 return -ESRCH; 1291 1292 err = proc_sched_autogroup_set_nice(p, nice); 1293 if (err) 1294 count = err; 1295 1296 put_task_struct(p); 1297 1298 return count; 1299 } 1300 1301 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1302 { 1303 int ret; 1304 1305 ret = single_open(filp, sched_autogroup_show, NULL); 1306 if (!ret) { 1307 struct seq_file *m = filp->private_data; 1308 1309 m->private = inode; 1310 } 1311 return ret; 1312 } 1313 1314 static const struct file_operations proc_pid_sched_autogroup_operations = { 1315 .open = sched_autogroup_open, 1316 .read = seq_read, 1317 .write = sched_autogroup_write, 1318 .llseek = seq_lseek, 1319 .release = single_release, 1320 }; 1321 1322 #endif /* CONFIG_SCHED_AUTOGROUP */ 1323 1324 static ssize_t comm_write(struct file *file, const char __user *buf, 1325 size_t count, loff_t *offset) 1326 { 1327 struct inode *inode = file_inode(file); 1328 struct task_struct *p; 1329 char buffer[TASK_COMM_LEN]; 1330 const size_t maxlen = sizeof(buffer) - 1; 1331 1332 memset(buffer, 0, sizeof(buffer)); 1333 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count)) 1334 return -EFAULT; 1335 1336 p = get_proc_task(inode); 1337 if (!p) 1338 return -ESRCH; 1339 1340 if (same_thread_group(current, p)) 1341 set_task_comm(p, buffer); 1342 else 1343 count = -EINVAL; 1344 1345 put_task_struct(p); 1346 1347 return count; 1348 } 1349 1350 static int comm_show(struct seq_file *m, void *v) 1351 { 1352 struct inode *inode = m->private; 1353 struct task_struct *p; 1354 1355 p = get_proc_task(inode); 1356 if (!p) 1357 return -ESRCH; 1358 1359 task_lock(p); 1360 seq_printf(m, "%s\n", p->comm); 1361 task_unlock(p); 1362 1363 put_task_struct(p); 1364 1365 return 0; 1366 } 1367 1368 static int comm_open(struct inode *inode, struct file *filp) 1369 { 1370 return single_open(filp, comm_show, inode); 1371 } 1372 1373 static const struct file_operations proc_pid_set_comm_operations = { 1374 .open = comm_open, 1375 .read = seq_read, 1376 .write = comm_write, 1377 .llseek = seq_lseek, 1378 .release = single_release, 1379 }; 1380 1381 static int proc_exe_link(struct dentry *dentry, struct path *exe_path) 1382 { 1383 struct task_struct *task; 1384 struct mm_struct *mm; 1385 struct file *exe_file; 1386 1387 task = get_proc_task(dentry->d_inode); 1388 if (!task) 1389 return -ENOENT; 1390 mm = get_task_mm(task); 1391 put_task_struct(task); 1392 if (!mm) 1393 return -ENOENT; 1394 exe_file = get_mm_exe_file(mm); 1395 mmput(mm); 1396 if (exe_file) { 1397 *exe_path = exe_file->f_path; 1398 path_get(&exe_file->f_path); 1399 fput(exe_file); 1400 return 0; 1401 } else 1402 return -ENOENT; 1403 } 1404 1405 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1406 { 1407 struct inode *inode = dentry->d_inode; 1408 struct path path; 1409 int error = -EACCES; 1410 1411 /* Are we allowed to snoop on the tasks file descriptors? */ 1412 if (!proc_fd_access_allowed(inode)) 1413 goto out; 1414 1415 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1416 if (error) 1417 goto out; 1418 1419 nd_jump_link(nd, &path); 1420 return NULL; 1421 out: 1422 return ERR_PTR(error); 1423 } 1424 1425 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1426 { 1427 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1428 char *pathname; 1429 int len; 1430 1431 if (!tmp) 1432 return -ENOMEM; 1433 1434 pathname = d_path(path, tmp, PAGE_SIZE); 1435 len = PTR_ERR(pathname); 1436 if (IS_ERR(pathname)) 1437 goto out; 1438 len = tmp + PAGE_SIZE - 1 - pathname; 1439 1440 if (len > buflen) 1441 len = buflen; 1442 if (copy_to_user(buffer, pathname, len)) 1443 len = -EFAULT; 1444 out: 1445 free_page((unsigned long)tmp); 1446 return len; 1447 } 1448 1449 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1450 { 1451 int error = -EACCES; 1452 struct inode *inode = dentry->d_inode; 1453 struct path path; 1454 1455 /* Are we allowed to snoop on the tasks file descriptors? */ 1456 if (!proc_fd_access_allowed(inode)) 1457 goto out; 1458 1459 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1460 if (error) 1461 goto out; 1462 1463 error = do_proc_readlink(&path, buffer, buflen); 1464 path_put(&path); 1465 out: 1466 return error; 1467 } 1468 1469 const struct inode_operations proc_pid_link_inode_operations = { 1470 .readlink = proc_pid_readlink, 1471 .follow_link = proc_pid_follow_link, 1472 .setattr = proc_setattr, 1473 }; 1474 1475 1476 /* building an inode */ 1477 1478 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1479 { 1480 struct inode * inode; 1481 struct proc_inode *ei; 1482 const struct cred *cred; 1483 1484 /* We need a new inode */ 1485 1486 inode = new_inode(sb); 1487 if (!inode) 1488 goto out; 1489 1490 /* Common stuff */ 1491 ei = PROC_I(inode); 1492 inode->i_ino = get_next_ino(); 1493 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1494 inode->i_op = &proc_def_inode_operations; 1495 1496 /* 1497 * grab the reference to task. 1498 */ 1499 ei->pid = get_task_pid(task, PIDTYPE_PID); 1500 if (!ei->pid) 1501 goto out_unlock; 1502 1503 if (task_dumpable(task)) { 1504 rcu_read_lock(); 1505 cred = __task_cred(task); 1506 inode->i_uid = cred->euid; 1507 inode->i_gid = cred->egid; 1508 rcu_read_unlock(); 1509 } 1510 security_task_to_inode(task, inode); 1511 1512 out: 1513 return inode; 1514 1515 out_unlock: 1516 iput(inode); 1517 return NULL; 1518 } 1519 1520 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1521 { 1522 struct inode *inode = dentry->d_inode; 1523 struct task_struct *task; 1524 const struct cred *cred; 1525 struct pid_namespace *pid = dentry->d_sb->s_fs_info; 1526 1527 generic_fillattr(inode, stat); 1528 1529 rcu_read_lock(); 1530 stat->uid = GLOBAL_ROOT_UID; 1531 stat->gid = GLOBAL_ROOT_GID; 1532 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1533 if (task) { 1534 if (!has_pid_permissions(pid, task, 2)) { 1535 rcu_read_unlock(); 1536 /* 1537 * This doesn't prevent learning whether PID exists, 1538 * it only makes getattr() consistent with readdir(). 1539 */ 1540 return -ENOENT; 1541 } 1542 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1543 task_dumpable(task)) { 1544 cred = __task_cred(task); 1545 stat->uid = cred->euid; 1546 stat->gid = cred->egid; 1547 } 1548 } 1549 rcu_read_unlock(); 1550 return 0; 1551 } 1552 1553 /* dentry stuff */ 1554 1555 /* 1556 * Exceptional case: normally we are not allowed to unhash a busy 1557 * directory. In this case, however, we can do it - no aliasing problems 1558 * due to the way we treat inodes. 1559 * 1560 * Rewrite the inode's ownerships here because the owning task may have 1561 * performed a setuid(), etc. 1562 * 1563 * Before the /proc/pid/status file was created the only way to read 1564 * the effective uid of a /process was to stat /proc/pid. Reading 1565 * /proc/pid/status is slow enough that procps and other packages 1566 * kept stating /proc/pid. To keep the rules in /proc simple I have 1567 * made this apply to all per process world readable and executable 1568 * directories. 1569 */ 1570 int pid_revalidate(struct dentry *dentry, unsigned int flags) 1571 { 1572 struct inode *inode; 1573 struct task_struct *task; 1574 const struct cred *cred; 1575 1576 if (flags & LOOKUP_RCU) 1577 return -ECHILD; 1578 1579 inode = dentry->d_inode; 1580 task = get_proc_task(inode); 1581 1582 if (task) { 1583 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1584 task_dumpable(task)) { 1585 rcu_read_lock(); 1586 cred = __task_cred(task); 1587 inode->i_uid = cred->euid; 1588 inode->i_gid = cred->egid; 1589 rcu_read_unlock(); 1590 } else { 1591 inode->i_uid = GLOBAL_ROOT_UID; 1592 inode->i_gid = GLOBAL_ROOT_GID; 1593 } 1594 inode->i_mode &= ~(S_ISUID | S_ISGID); 1595 security_task_to_inode(task, inode); 1596 put_task_struct(task); 1597 return 1; 1598 } 1599 d_drop(dentry); 1600 return 0; 1601 } 1602 1603 static inline bool proc_inode_is_dead(struct inode *inode) 1604 { 1605 return !proc_pid(inode)->tasks[PIDTYPE_PID].first; 1606 } 1607 1608 int pid_delete_dentry(const struct dentry *dentry) 1609 { 1610 /* Is the task we represent dead? 1611 * If so, then don't put the dentry on the lru list, 1612 * kill it immediately. 1613 */ 1614 return proc_inode_is_dead(dentry->d_inode); 1615 } 1616 1617 const struct dentry_operations pid_dentry_operations = 1618 { 1619 .d_revalidate = pid_revalidate, 1620 .d_delete = pid_delete_dentry, 1621 }; 1622 1623 /* Lookups */ 1624 1625 /* 1626 * Fill a directory entry. 1627 * 1628 * If possible create the dcache entry and derive our inode number and 1629 * file type from dcache entry. 1630 * 1631 * Since all of the proc inode numbers are dynamically generated, the inode 1632 * numbers do not exist until the inode is cache. This means creating the 1633 * the dcache entry in readdir is necessary to keep the inode numbers 1634 * reported by readdir in sync with the inode numbers reported 1635 * by stat. 1636 */ 1637 bool proc_fill_cache(struct file *file, struct dir_context *ctx, 1638 const char *name, int len, 1639 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1640 { 1641 struct dentry *child, *dir = file->f_path.dentry; 1642 struct qstr qname = QSTR_INIT(name, len); 1643 struct inode *inode; 1644 unsigned type; 1645 ino_t ino; 1646 1647 child = d_hash_and_lookup(dir, &qname); 1648 if (!child) { 1649 child = d_alloc(dir, &qname); 1650 if (!child) 1651 goto end_instantiate; 1652 if (instantiate(dir->d_inode, child, task, ptr) < 0) { 1653 dput(child); 1654 goto end_instantiate; 1655 } 1656 } 1657 inode = child->d_inode; 1658 ino = inode->i_ino; 1659 type = inode->i_mode >> 12; 1660 dput(child); 1661 return dir_emit(ctx, name, len, ino, type); 1662 1663 end_instantiate: 1664 return dir_emit(ctx, name, len, 1, DT_UNKNOWN); 1665 } 1666 1667 #ifdef CONFIG_CHECKPOINT_RESTORE 1668 1669 /* 1670 * dname_to_vma_addr - maps a dentry name into two unsigned longs 1671 * which represent vma start and end addresses. 1672 */ 1673 static int dname_to_vma_addr(struct dentry *dentry, 1674 unsigned long *start, unsigned long *end) 1675 { 1676 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2) 1677 return -EINVAL; 1678 1679 return 0; 1680 } 1681 1682 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags) 1683 { 1684 unsigned long vm_start, vm_end; 1685 bool exact_vma_exists = false; 1686 struct mm_struct *mm = NULL; 1687 struct task_struct *task; 1688 const struct cred *cred; 1689 struct inode *inode; 1690 int status = 0; 1691 1692 if (flags & LOOKUP_RCU) 1693 return -ECHILD; 1694 1695 if (!capable(CAP_SYS_ADMIN)) { 1696 status = -EPERM; 1697 goto out_notask; 1698 } 1699 1700 inode = dentry->d_inode; 1701 task = get_proc_task(inode); 1702 if (!task) 1703 goto out_notask; 1704 1705 mm = mm_access(task, PTRACE_MODE_READ); 1706 if (IS_ERR_OR_NULL(mm)) 1707 goto out; 1708 1709 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 1710 down_read(&mm->mmap_sem); 1711 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end); 1712 up_read(&mm->mmap_sem); 1713 } 1714 1715 mmput(mm); 1716 1717 if (exact_vma_exists) { 1718 if (task_dumpable(task)) { 1719 rcu_read_lock(); 1720 cred = __task_cred(task); 1721 inode->i_uid = cred->euid; 1722 inode->i_gid = cred->egid; 1723 rcu_read_unlock(); 1724 } else { 1725 inode->i_uid = GLOBAL_ROOT_UID; 1726 inode->i_gid = GLOBAL_ROOT_GID; 1727 } 1728 security_task_to_inode(task, inode); 1729 status = 1; 1730 } 1731 1732 out: 1733 put_task_struct(task); 1734 1735 out_notask: 1736 if (status <= 0) 1737 d_drop(dentry); 1738 1739 return status; 1740 } 1741 1742 static const struct dentry_operations tid_map_files_dentry_operations = { 1743 .d_revalidate = map_files_d_revalidate, 1744 .d_delete = pid_delete_dentry, 1745 }; 1746 1747 static int proc_map_files_get_link(struct dentry *dentry, struct path *path) 1748 { 1749 unsigned long vm_start, vm_end; 1750 struct vm_area_struct *vma; 1751 struct task_struct *task; 1752 struct mm_struct *mm; 1753 int rc; 1754 1755 rc = -ENOENT; 1756 task = get_proc_task(dentry->d_inode); 1757 if (!task) 1758 goto out; 1759 1760 mm = get_task_mm(task); 1761 put_task_struct(task); 1762 if (!mm) 1763 goto out; 1764 1765 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 1766 if (rc) 1767 goto out_mmput; 1768 1769 rc = -ENOENT; 1770 down_read(&mm->mmap_sem); 1771 vma = find_exact_vma(mm, vm_start, vm_end); 1772 if (vma && vma->vm_file) { 1773 *path = vma->vm_file->f_path; 1774 path_get(path); 1775 rc = 0; 1776 } 1777 up_read(&mm->mmap_sem); 1778 1779 out_mmput: 1780 mmput(mm); 1781 out: 1782 return rc; 1783 } 1784 1785 struct map_files_info { 1786 fmode_t mode; 1787 unsigned long len; 1788 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */ 1789 }; 1790 1791 static int 1792 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry, 1793 struct task_struct *task, const void *ptr) 1794 { 1795 fmode_t mode = (fmode_t)(unsigned long)ptr; 1796 struct proc_inode *ei; 1797 struct inode *inode; 1798 1799 inode = proc_pid_make_inode(dir->i_sb, task); 1800 if (!inode) 1801 return -ENOENT; 1802 1803 ei = PROC_I(inode); 1804 ei->op.proc_get_link = proc_map_files_get_link; 1805 1806 inode->i_op = &proc_pid_link_inode_operations; 1807 inode->i_size = 64; 1808 inode->i_mode = S_IFLNK; 1809 1810 if (mode & FMODE_READ) 1811 inode->i_mode |= S_IRUSR; 1812 if (mode & FMODE_WRITE) 1813 inode->i_mode |= S_IWUSR; 1814 1815 d_set_d_op(dentry, &tid_map_files_dentry_operations); 1816 d_add(dentry, inode); 1817 1818 return 0; 1819 } 1820 1821 static struct dentry *proc_map_files_lookup(struct inode *dir, 1822 struct dentry *dentry, unsigned int flags) 1823 { 1824 unsigned long vm_start, vm_end; 1825 struct vm_area_struct *vma; 1826 struct task_struct *task; 1827 int result; 1828 struct mm_struct *mm; 1829 1830 result = -EPERM; 1831 if (!capable(CAP_SYS_ADMIN)) 1832 goto out; 1833 1834 result = -ENOENT; 1835 task = get_proc_task(dir); 1836 if (!task) 1837 goto out; 1838 1839 result = -EACCES; 1840 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 1841 goto out_put_task; 1842 1843 result = -ENOENT; 1844 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 1845 goto out_put_task; 1846 1847 mm = get_task_mm(task); 1848 if (!mm) 1849 goto out_put_task; 1850 1851 down_read(&mm->mmap_sem); 1852 vma = find_exact_vma(mm, vm_start, vm_end); 1853 if (!vma) 1854 goto out_no_vma; 1855 1856 if (vma->vm_file) 1857 result = proc_map_files_instantiate(dir, dentry, task, 1858 (void *)(unsigned long)vma->vm_file->f_mode); 1859 1860 out_no_vma: 1861 up_read(&mm->mmap_sem); 1862 mmput(mm); 1863 out_put_task: 1864 put_task_struct(task); 1865 out: 1866 return ERR_PTR(result); 1867 } 1868 1869 static const struct inode_operations proc_map_files_inode_operations = { 1870 .lookup = proc_map_files_lookup, 1871 .permission = proc_fd_permission, 1872 .setattr = proc_setattr, 1873 }; 1874 1875 static int 1876 proc_map_files_readdir(struct file *file, struct dir_context *ctx) 1877 { 1878 struct vm_area_struct *vma; 1879 struct task_struct *task; 1880 struct mm_struct *mm; 1881 unsigned long nr_files, pos, i; 1882 struct flex_array *fa = NULL; 1883 struct map_files_info info; 1884 struct map_files_info *p; 1885 int ret; 1886 1887 ret = -EPERM; 1888 if (!capable(CAP_SYS_ADMIN)) 1889 goto out; 1890 1891 ret = -ENOENT; 1892 task = get_proc_task(file_inode(file)); 1893 if (!task) 1894 goto out; 1895 1896 ret = -EACCES; 1897 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 1898 goto out_put_task; 1899 1900 ret = 0; 1901 if (!dir_emit_dots(file, ctx)) 1902 goto out_put_task; 1903 1904 mm = get_task_mm(task); 1905 if (!mm) 1906 goto out_put_task; 1907 down_read(&mm->mmap_sem); 1908 1909 nr_files = 0; 1910 1911 /* 1912 * We need two passes here: 1913 * 1914 * 1) Collect vmas of mapped files with mmap_sem taken 1915 * 2) Release mmap_sem and instantiate entries 1916 * 1917 * otherwise we get lockdep complained, since filldir() 1918 * routine might require mmap_sem taken in might_fault(). 1919 */ 1920 1921 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 1922 if (vma->vm_file && ++pos > ctx->pos) 1923 nr_files++; 1924 } 1925 1926 if (nr_files) { 1927 fa = flex_array_alloc(sizeof(info), nr_files, 1928 GFP_KERNEL); 1929 if (!fa || flex_array_prealloc(fa, 0, nr_files, 1930 GFP_KERNEL)) { 1931 ret = -ENOMEM; 1932 if (fa) 1933 flex_array_free(fa); 1934 up_read(&mm->mmap_sem); 1935 mmput(mm); 1936 goto out_put_task; 1937 } 1938 for (i = 0, vma = mm->mmap, pos = 2; vma; 1939 vma = vma->vm_next) { 1940 if (!vma->vm_file) 1941 continue; 1942 if (++pos <= ctx->pos) 1943 continue; 1944 1945 info.mode = vma->vm_file->f_mode; 1946 info.len = snprintf(info.name, 1947 sizeof(info.name), "%lx-%lx", 1948 vma->vm_start, vma->vm_end); 1949 if (flex_array_put(fa, i++, &info, GFP_KERNEL)) 1950 BUG(); 1951 } 1952 } 1953 up_read(&mm->mmap_sem); 1954 1955 for (i = 0; i < nr_files; i++) { 1956 p = flex_array_get(fa, i); 1957 if (!proc_fill_cache(file, ctx, 1958 p->name, p->len, 1959 proc_map_files_instantiate, 1960 task, 1961 (void *)(unsigned long)p->mode)) 1962 break; 1963 ctx->pos++; 1964 } 1965 if (fa) 1966 flex_array_free(fa); 1967 mmput(mm); 1968 1969 out_put_task: 1970 put_task_struct(task); 1971 out: 1972 return ret; 1973 } 1974 1975 static const struct file_operations proc_map_files_operations = { 1976 .read = generic_read_dir, 1977 .iterate = proc_map_files_readdir, 1978 .llseek = default_llseek, 1979 }; 1980 1981 struct timers_private { 1982 struct pid *pid; 1983 struct task_struct *task; 1984 struct sighand_struct *sighand; 1985 struct pid_namespace *ns; 1986 unsigned long flags; 1987 }; 1988 1989 static void *timers_start(struct seq_file *m, loff_t *pos) 1990 { 1991 struct timers_private *tp = m->private; 1992 1993 tp->task = get_pid_task(tp->pid, PIDTYPE_PID); 1994 if (!tp->task) 1995 return ERR_PTR(-ESRCH); 1996 1997 tp->sighand = lock_task_sighand(tp->task, &tp->flags); 1998 if (!tp->sighand) 1999 return ERR_PTR(-ESRCH); 2000 2001 return seq_list_start(&tp->task->signal->posix_timers, *pos); 2002 } 2003 2004 static void *timers_next(struct seq_file *m, void *v, loff_t *pos) 2005 { 2006 struct timers_private *tp = m->private; 2007 return seq_list_next(v, &tp->task->signal->posix_timers, pos); 2008 } 2009 2010 static void timers_stop(struct seq_file *m, void *v) 2011 { 2012 struct timers_private *tp = m->private; 2013 2014 if (tp->sighand) { 2015 unlock_task_sighand(tp->task, &tp->flags); 2016 tp->sighand = NULL; 2017 } 2018 2019 if (tp->task) { 2020 put_task_struct(tp->task); 2021 tp->task = NULL; 2022 } 2023 } 2024 2025 static int show_timer(struct seq_file *m, void *v) 2026 { 2027 struct k_itimer *timer; 2028 struct timers_private *tp = m->private; 2029 int notify; 2030 static const char * const nstr[] = { 2031 [SIGEV_SIGNAL] = "signal", 2032 [SIGEV_NONE] = "none", 2033 [SIGEV_THREAD] = "thread", 2034 }; 2035 2036 timer = list_entry((struct list_head *)v, struct k_itimer, list); 2037 notify = timer->it_sigev_notify; 2038 2039 seq_printf(m, "ID: %d\n", timer->it_id); 2040 seq_printf(m, "signal: %d/%p\n", timer->sigq->info.si_signo, 2041 timer->sigq->info.si_value.sival_ptr); 2042 seq_printf(m, "notify: %s/%s.%d\n", 2043 nstr[notify & ~SIGEV_THREAD_ID], 2044 (notify & SIGEV_THREAD_ID) ? "tid" : "pid", 2045 pid_nr_ns(timer->it_pid, tp->ns)); 2046 seq_printf(m, "ClockID: %d\n", timer->it_clock); 2047 2048 return 0; 2049 } 2050 2051 static const struct seq_operations proc_timers_seq_ops = { 2052 .start = timers_start, 2053 .next = timers_next, 2054 .stop = timers_stop, 2055 .show = show_timer, 2056 }; 2057 2058 static int proc_timers_open(struct inode *inode, struct file *file) 2059 { 2060 struct timers_private *tp; 2061 2062 tp = __seq_open_private(file, &proc_timers_seq_ops, 2063 sizeof(struct timers_private)); 2064 if (!tp) 2065 return -ENOMEM; 2066 2067 tp->pid = proc_pid(inode); 2068 tp->ns = inode->i_sb->s_fs_info; 2069 return 0; 2070 } 2071 2072 static const struct file_operations proc_timers_operations = { 2073 .open = proc_timers_open, 2074 .read = seq_read, 2075 .llseek = seq_lseek, 2076 .release = seq_release_private, 2077 }; 2078 #endif /* CONFIG_CHECKPOINT_RESTORE */ 2079 2080 static int proc_pident_instantiate(struct inode *dir, 2081 struct dentry *dentry, struct task_struct *task, const void *ptr) 2082 { 2083 const struct pid_entry *p = ptr; 2084 struct inode *inode; 2085 struct proc_inode *ei; 2086 2087 inode = proc_pid_make_inode(dir->i_sb, task); 2088 if (!inode) 2089 goto out; 2090 2091 ei = PROC_I(inode); 2092 inode->i_mode = p->mode; 2093 if (S_ISDIR(inode->i_mode)) 2094 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2095 if (p->iop) 2096 inode->i_op = p->iop; 2097 if (p->fop) 2098 inode->i_fop = p->fop; 2099 ei->op = p->op; 2100 d_set_d_op(dentry, &pid_dentry_operations); 2101 d_add(dentry, inode); 2102 /* Close the race of the process dying before we return the dentry */ 2103 if (pid_revalidate(dentry, 0)) 2104 return 0; 2105 out: 2106 return -ENOENT; 2107 } 2108 2109 static struct dentry *proc_pident_lookup(struct inode *dir, 2110 struct dentry *dentry, 2111 const struct pid_entry *ents, 2112 unsigned int nents) 2113 { 2114 int error; 2115 struct task_struct *task = get_proc_task(dir); 2116 const struct pid_entry *p, *last; 2117 2118 error = -ENOENT; 2119 2120 if (!task) 2121 goto out_no_task; 2122 2123 /* 2124 * Yes, it does not scale. And it should not. Don't add 2125 * new entries into /proc/<tgid>/ without very good reasons. 2126 */ 2127 last = &ents[nents - 1]; 2128 for (p = ents; p <= last; p++) { 2129 if (p->len != dentry->d_name.len) 2130 continue; 2131 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2132 break; 2133 } 2134 if (p > last) 2135 goto out; 2136 2137 error = proc_pident_instantiate(dir, dentry, task, p); 2138 out: 2139 put_task_struct(task); 2140 out_no_task: 2141 return ERR_PTR(error); 2142 } 2143 2144 static int proc_pident_readdir(struct file *file, struct dir_context *ctx, 2145 const struct pid_entry *ents, unsigned int nents) 2146 { 2147 struct task_struct *task = get_proc_task(file_inode(file)); 2148 const struct pid_entry *p; 2149 2150 if (!task) 2151 return -ENOENT; 2152 2153 if (!dir_emit_dots(file, ctx)) 2154 goto out; 2155 2156 if (ctx->pos >= nents + 2) 2157 goto out; 2158 2159 for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) { 2160 if (!proc_fill_cache(file, ctx, p->name, p->len, 2161 proc_pident_instantiate, task, p)) 2162 break; 2163 ctx->pos++; 2164 } 2165 out: 2166 put_task_struct(task); 2167 return 0; 2168 } 2169 2170 #ifdef CONFIG_SECURITY 2171 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2172 size_t count, loff_t *ppos) 2173 { 2174 struct inode * inode = file_inode(file); 2175 char *p = NULL; 2176 ssize_t length; 2177 struct task_struct *task = get_proc_task(inode); 2178 2179 if (!task) 2180 return -ESRCH; 2181 2182 length = security_getprocattr(task, 2183 (char*)file->f_path.dentry->d_name.name, 2184 &p); 2185 put_task_struct(task); 2186 if (length > 0) 2187 length = simple_read_from_buffer(buf, count, ppos, p, length); 2188 kfree(p); 2189 return length; 2190 } 2191 2192 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2193 size_t count, loff_t *ppos) 2194 { 2195 struct inode * inode = file_inode(file); 2196 char *page; 2197 ssize_t length; 2198 struct task_struct *task = get_proc_task(inode); 2199 2200 length = -ESRCH; 2201 if (!task) 2202 goto out_no_task; 2203 if (count > PAGE_SIZE) 2204 count = PAGE_SIZE; 2205 2206 /* No partial writes. */ 2207 length = -EINVAL; 2208 if (*ppos != 0) 2209 goto out; 2210 2211 length = -ENOMEM; 2212 page = (char*)__get_free_page(GFP_TEMPORARY); 2213 if (!page) 2214 goto out; 2215 2216 length = -EFAULT; 2217 if (copy_from_user(page, buf, count)) 2218 goto out_free; 2219 2220 /* Guard against adverse ptrace interaction */ 2221 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex); 2222 if (length < 0) 2223 goto out_free; 2224 2225 length = security_setprocattr(task, 2226 (char*)file->f_path.dentry->d_name.name, 2227 (void*)page, count); 2228 mutex_unlock(&task->signal->cred_guard_mutex); 2229 out_free: 2230 free_page((unsigned long) page); 2231 out: 2232 put_task_struct(task); 2233 out_no_task: 2234 return length; 2235 } 2236 2237 static const struct file_operations proc_pid_attr_operations = { 2238 .read = proc_pid_attr_read, 2239 .write = proc_pid_attr_write, 2240 .llseek = generic_file_llseek, 2241 }; 2242 2243 static const struct pid_entry attr_dir_stuff[] = { 2244 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2245 REG("prev", S_IRUGO, proc_pid_attr_operations), 2246 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2247 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2248 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2249 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2250 }; 2251 2252 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx) 2253 { 2254 return proc_pident_readdir(file, ctx, 2255 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2256 } 2257 2258 static const struct file_operations proc_attr_dir_operations = { 2259 .read = generic_read_dir, 2260 .iterate = proc_attr_dir_readdir, 2261 .llseek = default_llseek, 2262 }; 2263 2264 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2265 struct dentry *dentry, unsigned int flags) 2266 { 2267 return proc_pident_lookup(dir, dentry, 2268 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2269 } 2270 2271 static const struct inode_operations proc_attr_dir_inode_operations = { 2272 .lookup = proc_attr_dir_lookup, 2273 .getattr = pid_getattr, 2274 .setattr = proc_setattr, 2275 }; 2276 2277 #endif 2278 2279 #ifdef CONFIG_ELF_CORE 2280 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2281 size_t count, loff_t *ppos) 2282 { 2283 struct task_struct *task = get_proc_task(file_inode(file)); 2284 struct mm_struct *mm; 2285 char buffer[PROC_NUMBUF]; 2286 size_t len; 2287 int ret; 2288 2289 if (!task) 2290 return -ESRCH; 2291 2292 ret = 0; 2293 mm = get_task_mm(task); 2294 if (mm) { 2295 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2296 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2297 MMF_DUMP_FILTER_SHIFT)); 2298 mmput(mm); 2299 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2300 } 2301 2302 put_task_struct(task); 2303 2304 return ret; 2305 } 2306 2307 static ssize_t proc_coredump_filter_write(struct file *file, 2308 const char __user *buf, 2309 size_t count, 2310 loff_t *ppos) 2311 { 2312 struct task_struct *task; 2313 struct mm_struct *mm; 2314 char buffer[PROC_NUMBUF], *end; 2315 unsigned int val; 2316 int ret; 2317 int i; 2318 unsigned long mask; 2319 2320 ret = -EFAULT; 2321 memset(buffer, 0, sizeof(buffer)); 2322 if (count > sizeof(buffer) - 1) 2323 count = sizeof(buffer) - 1; 2324 if (copy_from_user(buffer, buf, count)) 2325 goto out_no_task; 2326 2327 ret = -EINVAL; 2328 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2329 if (*end == '\n') 2330 end++; 2331 if (end - buffer == 0) 2332 goto out_no_task; 2333 2334 ret = -ESRCH; 2335 task = get_proc_task(file_inode(file)); 2336 if (!task) 2337 goto out_no_task; 2338 2339 ret = end - buffer; 2340 mm = get_task_mm(task); 2341 if (!mm) 2342 goto out_no_mm; 2343 2344 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2345 if (val & mask) 2346 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2347 else 2348 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2349 } 2350 2351 mmput(mm); 2352 out_no_mm: 2353 put_task_struct(task); 2354 out_no_task: 2355 return ret; 2356 } 2357 2358 static const struct file_operations proc_coredump_filter_operations = { 2359 .read = proc_coredump_filter_read, 2360 .write = proc_coredump_filter_write, 2361 .llseek = generic_file_llseek, 2362 }; 2363 #endif 2364 2365 #ifdef CONFIG_TASK_IO_ACCOUNTING 2366 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole) 2367 { 2368 struct task_io_accounting acct = task->ioac; 2369 unsigned long flags; 2370 int result; 2371 2372 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2373 if (result) 2374 return result; 2375 2376 if (!ptrace_may_access(task, PTRACE_MODE_READ)) { 2377 result = -EACCES; 2378 goto out_unlock; 2379 } 2380 2381 if (whole && lock_task_sighand(task, &flags)) { 2382 struct task_struct *t = task; 2383 2384 task_io_accounting_add(&acct, &task->signal->ioac); 2385 while_each_thread(task, t) 2386 task_io_accounting_add(&acct, &t->ioac); 2387 2388 unlock_task_sighand(task, &flags); 2389 } 2390 result = seq_printf(m, 2391 "rchar: %llu\n" 2392 "wchar: %llu\n" 2393 "syscr: %llu\n" 2394 "syscw: %llu\n" 2395 "read_bytes: %llu\n" 2396 "write_bytes: %llu\n" 2397 "cancelled_write_bytes: %llu\n", 2398 (unsigned long long)acct.rchar, 2399 (unsigned long long)acct.wchar, 2400 (unsigned long long)acct.syscr, 2401 (unsigned long long)acct.syscw, 2402 (unsigned long long)acct.read_bytes, 2403 (unsigned long long)acct.write_bytes, 2404 (unsigned long long)acct.cancelled_write_bytes); 2405 out_unlock: 2406 mutex_unlock(&task->signal->cred_guard_mutex); 2407 return result; 2408 } 2409 2410 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2411 struct pid *pid, struct task_struct *task) 2412 { 2413 return do_io_accounting(task, m, 0); 2414 } 2415 2416 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns, 2417 struct pid *pid, struct task_struct *task) 2418 { 2419 return do_io_accounting(task, m, 1); 2420 } 2421 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2422 2423 #ifdef CONFIG_USER_NS 2424 static int proc_id_map_open(struct inode *inode, struct file *file, 2425 const struct seq_operations *seq_ops) 2426 { 2427 struct user_namespace *ns = NULL; 2428 struct task_struct *task; 2429 struct seq_file *seq; 2430 int ret = -EINVAL; 2431 2432 task = get_proc_task(inode); 2433 if (task) { 2434 rcu_read_lock(); 2435 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2436 rcu_read_unlock(); 2437 put_task_struct(task); 2438 } 2439 if (!ns) 2440 goto err; 2441 2442 ret = seq_open(file, seq_ops); 2443 if (ret) 2444 goto err_put_ns; 2445 2446 seq = file->private_data; 2447 seq->private = ns; 2448 2449 return 0; 2450 err_put_ns: 2451 put_user_ns(ns); 2452 err: 2453 return ret; 2454 } 2455 2456 static int proc_id_map_release(struct inode *inode, struct file *file) 2457 { 2458 struct seq_file *seq = file->private_data; 2459 struct user_namespace *ns = seq->private; 2460 put_user_ns(ns); 2461 return seq_release(inode, file); 2462 } 2463 2464 static int proc_uid_map_open(struct inode *inode, struct file *file) 2465 { 2466 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2467 } 2468 2469 static int proc_gid_map_open(struct inode *inode, struct file *file) 2470 { 2471 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2472 } 2473 2474 static int proc_projid_map_open(struct inode *inode, struct file *file) 2475 { 2476 return proc_id_map_open(inode, file, &proc_projid_seq_operations); 2477 } 2478 2479 static const struct file_operations proc_uid_map_operations = { 2480 .open = proc_uid_map_open, 2481 .write = proc_uid_map_write, 2482 .read = seq_read, 2483 .llseek = seq_lseek, 2484 .release = proc_id_map_release, 2485 }; 2486 2487 static const struct file_operations proc_gid_map_operations = { 2488 .open = proc_gid_map_open, 2489 .write = proc_gid_map_write, 2490 .read = seq_read, 2491 .llseek = seq_lseek, 2492 .release = proc_id_map_release, 2493 }; 2494 2495 static const struct file_operations proc_projid_map_operations = { 2496 .open = proc_projid_map_open, 2497 .write = proc_projid_map_write, 2498 .read = seq_read, 2499 .llseek = seq_lseek, 2500 .release = proc_id_map_release, 2501 }; 2502 #endif /* CONFIG_USER_NS */ 2503 2504 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2505 struct pid *pid, struct task_struct *task) 2506 { 2507 int err = lock_trace(task); 2508 if (!err) { 2509 seq_printf(m, "%08x\n", task->personality); 2510 unlock_trace(task); 2511 } 2512 return err; 2513 } 2514 2515 /* 2516 * Thread groups 2517 */ 2518 static const struct file_operations proc_task_operations; 2519 static const struct inode_operations proc_task_inode_operations; 2520 2521 static const struct pid_entry tgid_base_stuff[] = { 2522 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2523 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2524 #ifdef CONFIG_CHECKPOINT_RESTORE 2525 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 2526 #endif 2527 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2528 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2529 #ifdef CONFIG_NET 2530 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2531 #endif 2532 REG("environ", S_IRUSR, proc_environ_operations), 2533 ONE("auxv", S_IRUSR, proc_pid_auxv), 2534 ONE("status", S_IRUGO, proc_pid_status), 2535 ONE("personality", S_IRUSR, proc_pid_personality), 2536 ONE("limits", S_IRUGO, proc_pid_limits), 2537 #ifdef CONFIG_SCHED_DEBUG 2538 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2539 #endif 2540 #ifdef CONFIG_SCHED_AUTOGROUP 2541 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2542 #endif 2543 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2544 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2545 ONE("syscall", S_IRUSR, proc_pid_syscall), 2546 #endif 2547 ONE("cmdline", S_IRUGO, proc_pid_cmdline), 2548 ONE("stat", S_IRUGO, proc_tgid_stat), 2549 ONE("statm", S_IRUGO, proc_pid_statm), 2550 REG("maps", S_IRUGO, proc_pid_maps_operations), 2551 #ifdef CONFIG_NUMA 2552 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 2553 #endif 2554 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2555 LNK("cwd", proc_cwd_link), 2556 LNK("root", proc_root_link), 2557 LNK("exe", proc_exe_link), 2558 REG("mounts", S_IRUGO, proc_mounts_operations), 2559 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2560 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2561 #ifdef CONFIG_PROC_PAGE_MONITOR 2562 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2563 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 2564 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2565 #endif 2566 #ifdef CONFIG_SECURITY 2567 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2568 #endif 2569 #ifdef CONFIG_KALLSYMS 2570 ONE("wchan", S_IRUGO, proc_pid_wchan), 2571 #endif 2572 #ifdef CONFIG_STACKTRACE 2573 ONE("stack", S_IRUSR, proc_pid_stack), 2574 #endif 2575 #ifdef CONFIG_SCHEDSTATS 2576 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 2577 #endif 2578 #ifdef CONFIG_LATENCYTOP 2579 REG("latency", S_IRUGO, proc_lstats_operations), 2580 #endif 2581 #ifdef CONFIG_PROC_PID_CPUSET 2582 REG("cpuset", S_IRUGO, proc_cpuset_operations), 2583 #endif 2584 #ifdef CONFIG_CGROUPS 2585 REG("cgroup", S_IRUGO, proc_cgroup_operations), 2586 #endif 2587 ONE("oom_score", S_IRUGO, proc_oom_score), 2588 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 2589 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2590 #ifdef CONFIG_AUDITSYSCALL 2591 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2592 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2593 #endif 2594 #ifdef CONFIG_FAULT_INJECTION 2595 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2596 #endif 2597 #ifdef CONFIG_ELF_CORE 2598 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2599 #endif 2600 #ifdef CONFIG_TASK_IO_ACCOUNTING 2601 ONE("io", S_IRUSR, proc_tgid_io_accounting), 2602 #endif 2603 #ifdef CONFIG_HARDWALL 2604 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 2605 #endif 2606 #ifdef CONFIG_USER_NS 2607 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 2608 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 2609 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 2610 #endif 2611 #ifdef CONFIG_CHECKPOINT_RESTORE 2612 REG("timers", S_IRUGO, proc_timers_operations), 2613 #endif 2614 }; 2615 2616 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) 2617 { 2618 return proc_pident_readdir(file, ctx, 2619 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2620 } 2621 2622 static const struct file_operations proc_tgid_base_operations = { 2623 .read = generic_read_dir, 2624 .iterate = proc_tgid_base_readdir, 2625 .llseek = default_llseek, 2626 }; 2627 2628 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 2629 { 2630 return proc_pident_lookup(dir, dentry, 2631 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2632 } 2633 2634 static const struct inode_operations proc_tgid_base_inode_operations = { 2635 .lookup = proc_tgid_base_lookup, 2636 .getattr = pid_getattr, 2637 .setattr = proc_setattr, 2638 .permission = proc_pid_permission, 2639 }; 2640 2641 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2642 { 2643 struct dentry *dentry, *leader, *dir; 2644 char buf[PROC_NUMBUF]; 2645 struct qstr name; 2646 2647 name.name = buf; 2648 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2649 /* no ->d_hash() rejects on procfs */ 2650 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2651 if (dentry) { 2652 shrink_dcache_parent(dentry); 2653 d_drop(dentry); 2654 dput(dentry); 2655 } 2656 2657 name.name = buf; 2658 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2659 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2660 if (!leader) 2661 goto out; 2662 2663 name.name = "task"; 2664 name.len = strlen(name.name); 2665 dir = d_hash_and_lookup(leader, &name); 2666 if (!dir) 2667 goto out_put_leader; 2668 2669 name.name = buf; 2670 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2671 dentry = d_hash_and_lookup(dir, &name); 2672 if (dentry) { 2673 shrink_dcache_parent(dentry); 2674 d_drop(dentry); 2675 dput(dentry); 2676 } 2677 2678 dput(dir); 2679 out_put_leader: 2680 dput(leader); 2681 out: 2682 return; 2683 } 2684 2685 /** 2686 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2687 * @task: task that should be flushed. 2688 * 2689 * When flushing dentries from proc, one needs to flush them from global 2690 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2691 * in. This call is supposed to do all of this job. 2692 * 2693 * Looks in the dcache for 2694 * /proc/@pid 2695 * /proc/@tgid/task/@pid 2696 * if either directory is present flushes it and all of it'ts children 2697 * from the dcache. 2698 * 2699 * It is safe and reasonable to cache /proc entries for a task until 2700 * that task exits. After that they just clog up the dcache with 2701 * useless entries, possibly causing useful dcache entries to be 2702 * flushed instead. This routine is proved to flush those useless 2703 * dcache entries at process exit time. 2704 * 2705 * NOTE: This routine is just an optimization so it does not guarantee 2706 * that no dcache entries will exist at process exit time it 2707 * just makes it very unlikely that any will persist. 2708 */ 2709 2710 void proc_flush_task(struct task_struct *task) 2711 { 2712 int i; 2713 struct pid *pid, *tgid; 2714 struct upid *upid; 2715 2716 pid = task_pid(task); 2717 tgid = task_tgid(task); 2718 2719 for (i = 0; i <= pid->level; i++) { 2720 upid = &pid->numbers[i]; 2721 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 2722 tgid->numbers[i].nr); 2723 } 2724 } 2725 2726 static int proc_pid_instantiate(struct inode *dir, 2727 struct dentry * dentry, 2728 struct task_struct *task, const void *ptr) 2729 { 2730 struct inode *inode; 2731 2732 inode = proc_pid_make_inode(dir->i_sb, task); 2733 if (!inode) 2734 goto out; 2735 2736 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2737 inode->i_op = &proc_tgid_base_inode_operations; 2738 inode->i_fop = &proc_tgid_base_operations; 2739 inode->i_flags|=S_IMMUTABLE; 2740 2741 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff, 2742 ARRAY_SIZE(tgid_base_stuff))); 2743 2744 d_set_d_op(dentry, &pid_dentry_operations); 2745 2746 d_add(dentry, inode); 2747 /* Close the race of the process dying before we return the dentry */ 2748 if (pid_revalidate(dentry, 0)) 2749 return 0; 2750 out: 2751 return -ENOENT; 2752 } 2753 2754 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 2755 { 2756 int result = -ENOENT; 2757 struct task_struct *task; 2758 unsigned tgid; 2759 struct pid_namespace *ns; 2760 2761 tgid = name_to_int(&dentry->d_name); 2762 if (tgid == ~0U) 2763 goto out; 2764 2765 ns = dentry->d_sb->s_fs_info; 2766 rcu_read_lock(); 2767 task = find_task_by_pid_ns(tgid, ns); 2768 if (task) 2769 get_task_struct(task); 2770 rcu_read_unlock(); 2771 if (!task) 2772 goto out; 2773 2774 result = proc_pid_instantiate(dir, dentry, task, NULL); 2775 put_task_struct(task); 2776 out: 2777 return ERR_PTR(result); 2778 } 2779 2780 /* 2781 * Find the first task with tgid >= tgid 2782 * 2783 */ 2784 struct tgid_iter { 2785 unsigned int tgid; 2786 struct task_struct *task; 2787 }; 2788 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 2789 { 2790 struct pid *pid; 2791 2792 if (iter.task) 2793 put_task_struct(iter.task); 2794 rcu_read_lock(); 2795 retry: 2796 iter.task = NULL; 2797 pid = find_ge_pid(iter.tgid, ns); 2798 if (pid) { 2799 iter.tgid = pid_nr_ns(pid, ns); 2800 iter.task = pid_task(pid, PIDTYPE_PID); 2801 /* What we to know is if the pid we have find is the 2802 * pid of a thread_group_leader. Testing for task 2803 * being a thread_group_leader is the obvious thing 2804 * todo but there is a window when it fails, due to 2805 * the pid transfer logic in de_thread. 2806 * 2807 * So we perform the straight forward test of seeing 2808 * if the pid we have found is the pid of a thread 2809 * group leader, and don't worry if the task we have 2810 * found doesn't happen to be a thread group leader. 2811 * As we don't care in the case of readdir. 2812 */ 2813 if (!iter.task || !has_group_leader_pid(iter.task)) { 2814 iter.tgid += 1; 2815 goto retry; 2816 } 2817 get_task_struct(iter.task); 2818 } 2819 rcu_read_unlock(); 2820 return iter; 2821 } 2822 2823 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2) 2824 2825 /* for the /proc/ directory itself, after non-process stuff has been done */ 2826 int proc_pid_readdir(struct file *file, struct dir_context *ctx) 2827 { 2828 struct tgid_iter iter; 2829 struct pid_namespace *ns = file->f_dentry->d_sb->s_fs_info; 2830 loff_t pos = ctx->pos; 2831 2832 if (pos >= PID_MAX_LIMIT + TGID_OFFSET) 2833 return 0; 2834 2835 if (pos == TGID_OFFSET - 2) { 2836 struct inode *inode = ns->proc_self->d_inode; 2837 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) 2838 return 0; 2839 ctx->pos = pos = pos + 1; 2840 } 2841 if (pos == TGID_OFFSET - 1) { 2842 struct inode *inode = ns->proc_thread_self->d_inode; 2843 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) 2844 return 0; 2845 ctx->pos = pos = pos + 1; 2846 } 2847 iter.tgid = pos - TGID_OFFSET; 2848 iter.task = NULL; 2849 for (iter = next_tgid(ns, iter); 2850 iter.task; 2851 iter.tgid += 1, iter = next_tgid(ns, iter)) { 2852 char name[PROC_NUMBUF]; 2853 int len; 2854 if (!has_pid_permissions(ns, iter.task, 2)) 2855 continue; 2856 2857 len = snprintf(name, sizeof(name), "%d", iter.tgid); 2858 ctx->pos = iter.tgid + TGID_OFFSET; 2859 if (!proc_fill_cache(file, ctx, name, len, 2860 proc_pid_instantiate, iter.task, NULL)) { 2861 put_task_struct(iter.task); 2862 return 0; 2863 } 2864 } 2865 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET; 2866 return 0; 2867 } 2868 2869 /* 2870 * Tasks 2871 */ 2872 static const struct pid_entry tid_base_stuff[] = { 2873 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2874 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2875 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2876 #ifdef CONFIG_NET 2877 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2878 #endif 2879 REG("environ", S_IRUSR, proc_environ_operations), 2880 ONE("auxv", S_IRUSR, proc_pid_auxv), 2881 ONE("status", S_IRUGO, proc_pid_status), 2882 ONE("personality", S_IRUSR, proc_pid_personality), 2883 ONE("limits", S_IRUGO, proc_pid_limits), 2884 #ifdef CONFIG_SCHED_DEBUG 2885 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2886 #endif 2887 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2888 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2889 ONE("syscall", S_IRUSR, proc_pid_syscall), 2890 #endif 2891 ONE("cmdline", S_IRUGO, proc_pid_cmdline), 2892 ONE("stat", S_IRUGO, proc_tid_stat), 2893 ONE("statm", S_IRUGO, proc_pid_statm), 2894 REG("maps", S_IRUGO, proc_tid_maps_operations), 2895 #ifdef CONFIG_CHECKPOINT_RESTORE 2896 REG("children", S_IRUGO, proc_tid_children_operations), 2897 #endif 2898 #ifdef CONFIG_NUMA 2899 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations), 2900 #endif 2901 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2902 LNK("cwd", proc_cwd_link), 2903 LNK("root", proc_root_link), 2904 LNK("exe", proc_exe_link), 2905 REG("mounts", S_IRUGO, proc_mounts_operations), 2906 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2907 #ifdef CONFIG_PROC_PAGE_MONITOR 2908 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2909 REG("smaps", S_IRUGO, proc_tid_smaps_operations), 2910 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2911 #endif 2912 #ifdef CONFIG_SECURITY 2913 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2914 #endif 2915 #ifdef CONFIG_KALLSYMS 2916 ONE("wchan", S_IRUGO, proc_pid_wchan), 2917 #endif 2918 #ifdef CONFIG_STACKTRACE 2919 ONE("stack", S_IRUSR, proc_pid_stack), 2920 #endif 2921 #ifdef CONFIG_SCHEDSTATS 2922 ONE("schedstat", S_IRUGO, proc_pid_schedstat), 2923 #endif 2924 #ifdef CONFIG_LATENCYTOP 2925 REG("latency", S_IRUGO, proc_lstats_operations), 2926 #endif 2927 #ifdef CONFIG_PROC_PID_CPUSET 2928 REG("cpuset", S_IRUGO, proc_cpuset_operations), 2929 #endif 2930 #ifdef CONFIG_CGROUPS 2931 REG("cgroup", S_IRUGO, proc_cgroup_operations), 2932 #endif 2933 ONE("oom_score", S_IRUGO, proc_oom_score), 2934 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), 2935 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2936 #ifdef CONFIG_AUDITSYSCALL 2937 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2938 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2939 #endif 2940 #ifdef CONFIG_FAULT_INJECTION 2941 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2942 #endif 2943 #ifdef CONFIG_TASK_IO_ACCOUNTING 2944 ONE("io", S_IRUSR, proc_tid_io_accounting), 2945 #endif 2946 #ifdef CONFIG_HARDWALL 2947 ONE("hardwall", S_IRUGO, proc_pid_hardwall), 2948 #endif 2949 #ifdef CONFIG_USER_NS 2950 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 2951 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 2952 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 2953 #endif 2954 }; 2955 2956 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx) 2957 { 2958 return proc_pident_readdir(file, ctx, 2959 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 2960 } 2961 2962 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 2963 { 2964 return proc_pident_lookup(dir, dentry, 2965 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 2966 } 2967 2968 static const struct file_operations proc_tid_base_operations = { 2969 .read = generic_read_dir, 2970 .iterate = proc_tid_base_readdir, 2971 .llseek = default_llseek, 2972 }; 2973 2974 static const struct inode_operations proc_tid_base_inode_operations = { 2975 .lookup = proc_tid_base_lookup, 2976 .getattr = pid_getattr, 2977 .setattr = proc_setattr, 2978 }; 2979 2980 static int proc_task_instantiate(struct inode *dir, 2981 struct dentry *dentry, struct task_struct *task, const void *ptr) 2982 { 2983 struct inode *inode; 2984 inode = proc_pid_make_inode(dir->i_sb, task); 2985 2986 if (!inode) 2987 goto out; 2988 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2989 inode->i_op = &proc_tid_base_inode_operations; 2990 inode->i_fop = &proc_tid_base_operations; 2991 inode->i_flags|=S_IMMUTABLE; 2992 2993 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff, 2994 ARRAY_SIZE(tid_base_stuff))); 2995 2996 d_set_d_op(dentry, &pid_dentry_operations); 2997 2998 d_add(dentry, inode); 2999 /* Close the race of the process dying before we return the dentry */ 3000 if (pid_revalidate(dentry, 0)) 3001 return 0; 3002 out: 3003 return -ENOENT; 3004 } 3005 3006 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3007 { 3008 int result = -ENOENT; 3009 struct task_struct *task; 3010 struct task_struct *leader = get_proc_task(dir); 3011 unsigned tid; 3012 struct pid_namespace *ns; 3013 3014 if (!leader) 3015 goto out_no_task; 3016 3017 tid = name_to_int(&dentry->d_name); 3018 if (tid == ~0U) 3019 goto out; 3020 3021 ns = dentry->d_sb->s_fs_info; 3022 rcu_read_lock(); 3023 task = find_task_by_pid_ns(tid, ns); 3024 if (task) 3025 get_task_struct(task); 3026 rcu_read_unlock(); 3027 if (!task) 3028 goto out; 3029 if (!same_thread_group(leader, task)) 3030 goto out_drop_task; 3031 3032 result = proc_task_instantiate(dir, dentry, task, NULL); 3033 out_drop_task: 3034 put_task_struct(task); 3035 out: 3036 put_task_struct(leader); 3037 out_no_task: 3038 return ERR_PTR(result); 3039 } 3040 3041 /* 3042 * Find the first tid of a thread group to return to user space. 3043 * 3044 * Usually this is just the thread group leader, but if the users 3045 * buffer was too small or there was a seek into the middle of the 3046 * directory we have more work todo. 3047 * 3048 * In the case of a short read we start with find_task_by_pid. 3049 * 3050 * In the case of a seek we start with the leader and walk nr 3051 * threads past it. 3052 */ 3053 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos, 3054 struct pid_namespace *ns) 3055 { 3056 struct task_struct *pos, *task; 3057 unsigned long nr = f_pos; 3058 3059 if (nr != f_pos) /* 32bit overflow? */ 3060 return NULL; 3061 3062 rcu_read_lock(); 3063 task = pid_task(pid, PIDTYPE_PID); 3064 if (!task) 3065 goto fail; 3066 3067 /* Attempt to start with the tid of a thread */ 3068 if (tid && nr) { 3069 pos = find_task_by_pid_ns(tid, ns); 3070 if (pos && same_thread_group(pos, task)) 3071 goto found; 3072 } 3073 3074 /* If nr exceeds the number of threads there is nothing todo */ 3075 if (nr >= get_nr_threads(task)) 3076 goto fail; 3077 3078 /* If we haven't found our starting place yet start 3079 * with the leader and walk nr threads forward. 3080 */ 3081 pos = task = task->group_leader; 3082 do { 3083 if (!nr--) 3084 goto found; 3085 } while_each_thread(task, pos); 3086 fail: 3087 pos = NULL; 3088 goto out; 3089 found: 3090 get_task_struct(pos); 3091 out: 3092 rcu_read_unlock(); 3093 return pos; 3094 } 3095 3096 /* 3097 * Find the next thread in the thread list. 3098 * Return NULL if there is an error or no next thread. 3099 * 3100 * The reference to the input task_struct is released. 3101 */ 3102 static struct task_struct *next_tid(struct task_struct *start) 3103 { 3104 struct task_struct *pos = NULL; 3105 rcu_read_lock(); 3106 if (pid_alive(start)) { 3107 pos = next_thread(start); 3108 if (thread_group_leader(pos)) 3109 pos = NULL; 3110 else 3111 get_task_struct(pos); 3112 } 3113 rcu_read_unlock(); 3114 put_task_struct(start); 3115 return pos; 3116 } 3117 3118 /* for the /proc/TGID/task/ directories */ 3119 static int proc_task_readdir(struct file *file, struct dir_context *ctx) 3120 { 3121 struct inode *inode = file_inode(file); 3122 struct task_struct *task; 3123 struct pid_namespace *ns; 3124 int tid; 3125 3126 if (proc_inode_is_dead(inode)) 3127 return -ENOENT; 3128 3129 if (!dir_emit_dots(file, ctx)) 3130 return 0; 3131 3132 /* f_version caches the tgid value that the last readdir call couldn't 3133 * return. lseek aka telldir automagically resets f_version to 0. 3134 */ 3135 ns = file->f_dentry->d_sb->s_fs_info; 3136 tid = (int)file->f_version; 3137 file->f_version = 0; 3138 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); 3139 task; 3140 task = next_tid(task), ctx->pos++) { 3141 char name[PROC_NUMBUF]; 3142 int len; 3143 tid = task_pid_nr_ns(task, ns); 3144 len = snprintf(name, sizeof(name), "%d", tid); 3145 if (!proc_fill_cache(file, ctx, name, len, 3146 proc_task_instantiate, task, NULL)) { 3147 /* returning this tgid failed, save it as the first 3148 * pid for the next readir call */ 3149 file->f_version = (u64)tid; 3150 put_task_struct(task); 3151 break; 3152 } 3153 } 3154 3155 return 0; 3156 } 3157 3158 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3159 { 3160 struct inode *inode = dentry->d_inode; 3161 struct task_struct *p = get_proc_task(inode); 3162 generic_fillattr(inode, stat); 3163 3164 if (p) { 3165 stat->nlink += get_nr_threads(p); 3166 put_task_struct(p); 3167 } 3168 3169 return 0; 3170 } 3171 3172 static const struct inode_operations proc_task_inode_operations = { 3173 .lookup = proc_task_lookup, 3174 .getattr = proc_task_getattr, 3175 .setattr = proc_setattr, 3176 .permission = proc_pid_permission, 3177 }; 3178 3179 static const struct file_operations proc_task_operations = { 3180 .read = generic_read_dir, 3181 .iterate = proc_task_readdir, 3182 .llseek = default_llseek, 3183 }; 3184