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/cgroup.h> 77 #include <linux/cpuset.h> 78 #include <linux/audit.h> 79 #include <linux/poll.h> 80 #include <linux/nsproxy.h> 81 #include <linux/oom.h> 82 #include <linux/elf.h> 83 #include <linux/pid_namespace.h> 84 #include <linux/fs_struct.h> 85 #include <linux/slab.h> 86 #include <linux/flex_array.h> 87 #ifdef CONFIG_HARDWALL 88 #include <asm/hardwall.h> 89 #endif 90 #include <trace/events/oom.h> 91 #include "internal.h" 92 93 /* NOTE: 94 * Implementing inode permission operations in /proc is almost 95 * certainly an error. Permission checks need to happen during 96 * each system call not at open time. The reason is that most of 97 * what we wish to check for permissions in /proc varies at runtime. 98 * 99 * The classic example of a problem is opening file descriptors 100 * in /proc for a task before it execs a suid executable. 101 */ 102 103 struct pid_entry { 104 char *name; 105 int len; 106 umode_t mode; 107 const struct inode_operations *iop; 108 const struct file_operations *fop; 109 union proc_op op; 110 }; 111 112 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 113 .name = (NAME), \ 114 .len = sizeof(NAME) - 1, \ 115 .mode = MODE, \ 116 .iop = IOP, \ 117 .fop = FOP, \ 118 .op = OP, \ 119 } 120 121 #define DIR(NAME, MODE, iops, fops) \ 122 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} ) 123 #define LNK(NAME, get_link) \ 124 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 125 &proc_pid_link_inode_operations, NULL, \ 126 { .proc_get_link = get_link } ) 127 #define REG(NAME, MODE, fops) \ 128 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {}) 129 #define INF(NAME, MODE, read) \ 130 NOD(NAME, (S_IFREG|(MODE)), \ 131 NULL, &proc_info_file_operations, \ 132 { .proc_read = read } ) 133 #define ONE(NAME, MODE, show) \ 134 NOD(NAME, (S_IFREG|(MODE)), \ 135 NULL, &proc_single_file_operations, \ 136 { .proc_show = show } ) 137 138 static int proc_fd_permission(struct inode *inode, int mask); 139 140 /* 141 * Count the number of hardlinks for the pid_entry table, excluding the . 142 * and .. links. 143 */ 144 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries, 145 unsigned int n) 146 { 147 unsigned int i; 148 unsigned int count; 149 150 count = 0; 151 for (i = 0; i < n; ++i) { 152 if (S_ISDIR(entries[i].mode)) 153 ++count; 154 } 155 156 return count; 157 } 158 159 static int get_task_root(struct task_struct *task, struct path *root) 160 { 161 int result = -ENOENT; 162 163 task_lock(task); 164 if (task->fs) { 165 get_fs_root(task->fs, root); 166 result = 0; 167 } 168 task_unlock(task); 169 return result; 170 } 171 172 static int proc_cwd_link(struct dentry *dentry, struct path *path) 173 { 174 struct task_struct *task = get_proc_task(dentry->d_inode); 175 int result = -ENOENT; 176 177 if (task) { 178 task_lock(task); 179 if (task->fs) { 180 get_fs_pwd(task->fs, path); 181 result = 0; 182 } 183 task_unlock(task); 184 put_task_struct(task); 185 } 186 return result; 187 } 188 189 static int proc_root_link(struct dentry *dentry, struct path *path) 190 { 191 struct task_struct *task = get_proc_task(dentry->d_inode); 192 int result = -ENOENT; 193 194 if (task) { 195 result = get_task_root(task, path); 196 put_task_struct(task); 197 } 198 return result; 199 } 200 201 struct mm_struct *mm_for_maps(struct task_struct *task) 202 { 203 return mm_access(task, PTRACE_MODE_READ); 204 } 205 206 static int proc_pid_cmdline(struct task_struct *task, char * buffer) 207 { 208 int res = 0; 209 unsigned int len; 210 struct mm_struct *mm = get_task_mm(task); 211 if (!mm) 212 goto out; 213 if (!mm->arg_end) 214 goto out_mm; /* Shh! No looking before we're done */ 215 216 len = mm->arg_end - mm->arg_start; 217 218 if (len > PAGE_SIZE) 219 len = PAGE_SIZE; 220 221 res = access_process_vm(task, mm->arg_start, buffer, len, 0); 222 223 // If the nul at the end of args has been overwritten, then 224 // assume application is using setproctitle(3). 225 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) { 226 len = strnlen(buffer, res); 227 if (len < res) { 228 res = len; 229 } else { 230 len = mm->env_end - mm->env_start; 231 if (len > PAGE_SIZE - res) 232 len = PAGE_SIZE - res; 233 res += access_process_vm(task, mm->env_start, buffer+res, len, 0); 234 res = strnlen(buffer, res); 235 } 236 } 237 out_mm: 238 mmput(mm); 239 out: 240 return res; 241 } 242 243 static int proc_pid_auxv(struct task_struct *task, char *buffer) 244 { 245 struct mm_struct *mm = mm_for_maps(task); 246 int res = PTR_ERR(mm); 247 if (mm && !IS_ERR(mm)) { 248 unsigned int nwords = 0; 249 do { 250 nwords += 2; 251 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 252 res = nwords * sizeof(mm->saved_auxv[0]); 253 if (res > PAGE_SIZE) 254 res = PAGE_SIZE; 255 memcpy(buffer, mm->saved_auxv, res); 256 mmput(mm); 257 } 258 return res; 259 } 260 261 262 #ifdef CONFIG_KALLSYMS 263 /* 264 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 265 * Returns the resolved symbol. If that fails, simply return the address. 266 */ 267 static int proc_pid_wchan(struct task_struct *task, char *buffer) 268 { 269 unsigned long wchan; 270 char symname[KSYM_NAME_LEN]; 271 272 wchan = get_wchan(task); 273 274 if (lookup_symbol_name(wchan, symname) < 0) 275 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 276 return 0; 277 else 278 return sprintf(buffer, "%lu", wchan); 279 else 280 return sprintf(buffer, "%s", symname); 281 } 282 #endif /* CONFIG_KALLSYMS */ 283 284 static int lock_trace(struct task_struct *task) 285 { 286 int err = mutex_lock_killable(&task->signal->cred_guard_mutex); 287 if (err) 288 return err; 289 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) { 290 mutex_unlock(&task->signal->cred_guard_mutex); 291 return -EPERM; 292 } 293 return 0; 294 } 295 296 static void unlock_trace(struct task_struct *task) 297 { 298 mutex_unlock(&task->signal->cred_guard_mutex); 299 } 300 301 #ifdef CONFIG_STACKTRACE 302 303 #define MAX_STACK_TRACE_DEPTH 64 304 305 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, 306 struct pid *pid, struct task_struct *task) 307 { 308 struct stack_trace trace; 309 unsigned long *entries; 310 int err; 311 int i; 312 313 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL); 314 if (!entries) 315 return -ENOMEM; 316 317 trace.nr_entries = 0; 318 trace.max_entries = MAX_STACK_TRACE_DEPTH; 319 trace.entries = entries; 320 trace.skip = 0; 321 322 err = lock_trace(task); 323 if (!err) { 324 save_stack_trace_tsk(task, &trace); 325 326 for (i = 0; i < trace.nr_entries; i++) { 327 seq_printf(m, "[<%pK>] %pS\n", 328 (void *)entries[i], (void *)entries[i]); 329 } 330 unlock_trace(task); 331 } 332 kfree(entries); 333 334 return err; 335 } 336 #endif 337 338 #ifdef CONFIG_SCHEDSTATS 339 /* 340 * Provides /proc/PID/schedstat 341 */ 342 static int proc_pid_schedstat(struct task_struct *task, char *buffer) 343 { 344 return sprintf(buffer, "%llu %llu %lu\n", 345 (unsigned long long)task->se.sum_exec_runtime, 346 (unsigned long long)task->sched_info.run_delay, 347 task->sched_info.pcount); 348 } 349 #endif 350 351 #ifdef CONFIG_LATENCYTOP 352 static int lstats_show_proc(struct seq_file *m, void *v) 353 { 354 int i; 355 struct inode *inode = m->private; 356 struct task_struct *task = get_proc_task(inode); 357 358 if (!task) 359 return -ESRCH; 360 seq_puts(m, "Latency Top version : v0.1\n"); 361 for (i = 0; i < 32; i++) { 362 struct latency_record *lr = &task->latency_record[i]; 363 if (lr->backtrace[0]) { 364 int q; 365 seq_printf(m, "%i %li %li", 366 lr->count, lr->time, lr->max); 367 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 368 unsigned long bt = lr->backtrace[q]; 369 if (!bt) 370 break; 371 if (bt == ULONG_MAX) 372 break; 373 seq_printf(m, " %ps", (void *)bt); 374 } 375 seq_putc(m, '\n'); 376 } 377 378 } 379 put_task_struct(task); 380 return 0; 381 } 382 383 static int lstats_open(struct inode *inode, struct file *file) 384 { 385 return single_open(file, lstats_show_proc, inode); 386 } 387 388 static ssize_t lstats_write(struct file *file, const char __user *buf, 389 size_t count, loff_t *offs) 390 { 391 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 392 393 if (!task) 394 return -ESRCH; 395 clear_all_latency_tracing(task); 396 put_task_struct(task); 397 398 return count; 399 } 400 401 static const struct file_operations proc_lstats_operations = { 402 .open = lstats_open, 403 .read = seq_read, 404 .write = lstats_write, 405 .llseek = seq_lseek, 406 .release = single_release, 407 }; 408 409 #endif 410 411 static int proc_oom_score(struct task_struct *task, char *buffer) 412 { 413 unsigned long points = 0; 414 415 read_lock(&tasklist_lock); 416 if (pid_alive(task)) 417 points = oom_badness(task, NULL, NULL, 418 totalram_pages + total_swap_pages); 419 read_unlock(&tasklist_lock); 420 return sprintf(buffer, "%lu\n", points); 421 } 422 423 struct limit_names { 424 char *name; 425 char *unit; 426 }; 427 428 static const struct limit_names lnames[RLIM_NLIMITS] = { 429 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 430 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 431 [RLIMIT_DATA] = {"Max data size", "bytes"}, 432 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 433 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 434 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 435 [RLIMIT_NPROC] = {"Max processes", "processes"}, 436 [RLIMIT_NOFILE] = {"Max open files", "files"}, 437 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 438 [RLIMIT_AS] = {"Max address space", "bytes"}, 439 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 440 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 441 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 442 [RLIMIT_NICE] = {"Max nice priority", NULL}, 443 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 444 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 445 }; 446 447 /* Display limits for a process */ 448 static int proc_pid_limits(struct task_struct *task, char *buffer) 449 { 450 unsigned int i; 451 int count = 0; 452 unsigned long flags; 453 char *bufptr = buffer; 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 count += sprintf(&bufptr[count], "%-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 count += sprintf(&bufptr[count], "%-25s %-20s ", 471 lnames[i].name, "unlimited"); 472 else 473 count += sprintf(&bufptr[count], "%-25s %-20lu ", 474 lnames[i].name, rlim[i].rlim_cur); 475 476 if (rlim[i].rlim_max == RLIM_INFINITY) 477 count += sprintf(&bufptr[count], "%-20s ", "unlimited"); 478 else 479 count += sprintf(&bufptr[count], "%-20lu ", 480 rlim[i].rlim_max); 481 482 if (lnames[i].unit) 483 count += sprintf(&bufptr[count], "%-10s\n", 484 lnames[i].unit); 485 else 486 count += sprintf(&bufptr[count], "\n"); 487 } 488 489 return count; 490 } 491 492 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 493 static int proc_pid_syscall(struct task_struct *task, char *buffer) 494 { 495 long nr; 496 unsigned long args[6], sp, pc; 497 int res = lock_trace(task); 498 if (res) 499 return res; 500 501 if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) 502 res = sprintf(buffer, "running\n"); 503 else if (nr < 0) 504 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc); 505 else 506 res = sprintf(buffer, 507 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", 508 nr, 509 args[0], args[1], args[2], args[3], args[4], args[5], 510 sp, pc); 511 unlock_trace(task); 512 return res; 513 } 514 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 515 516 /************************************************************************/ 517 /* Here the fs part begins */ 518 /************************************************************************/ 519 520 /* permission checks */ 521 static int proc_fd_access_allowed(struct inode *inode) 522 { 523 struct task_struct *task; 524 int allowed = 0; 525 /* Allow access to a task's file descriptors if it is us or we 526 * may use ptrace attach to the process and find out that 527 * information. 528 */ 529 task = get_proc_task(inode); 530 if (task) { 531 allowed = ptrace_may_access(task, PTRACE_MODE_READ); 532 put_task_struct(task); 533 } 534 return allowed; 535 } 536 537 int proc_setattr(struct dentry *dentry, struct iattr *attr) 538 { 539 int error; 540 struct inode *inode = dentry->d_inode; 541 542 if (attr->ia_valid & ATTR_MODE) 543 return -EPERM; 544 545 error = inode_change_ok(inode, attr); 546 if (error) 547 return error; 548 549 if ((attr->ia_valid & ATTR_SIZE) && 550 attr->ia_size != i_size_read(inode)) { 551 error = vmtruncate(inode, attr->ia_size); 552 if (error) 553 return error; 554 } 555 556 setattr_copy(inode, attr); 557 mark_inode_dirty(inode); 558 return 0; 559 } 560 561 /* 562 * May current process learn task's sched/cmdline info (for hide_pid_min=1) 563 * or euid/egid (for hide_pid_min=2)? 564 */ 565 static bool has_pid_permissions(struct pid_namespace *pid, 566 struct task_struct *task, 567 int hide_pid_min) 568 { 569 if (pid->hide_pid < hide_pid_min) 570 return true; 571 if (in_group_p(pid->pid_gid)) 572 return true; 573 return ptrace_may_access(task, PTRACE_MODE_READ); 574 } 575 576 577 static int proc_pid_permission(struct inode *inode, int mask) 578 { 579 struct pid_namespace *pid = inode->i_sb->s_fs_info; 580 struct task_struct *task; 581 bool has_perms; 582 583 task = get_proc_task(inode); 584 if (!task) 585 return -ESRCH; 586 has_perms = has_pid_permissions(pid, task, 1); 587 put_task_struct(task); 588 589 if (!has_perms) { 590 if (pid->hide_pid == 2) { 591 /* 592 * Let's make getdents(), stat(), and open() 593 * consistent with each other. If a process 594 * may not stat() a file, it shouldn't be seen 595 * in procfs at all. 596 */ 597 return -ENOENT; 598 } 599 600 return -EPERM; 601 } 602 return generic_permission(inode, mask); 603 } 604 605 606 607 static const struct inode_operations proc_def_inode_operations = { 608 .setattr = proc_setattr, 609 }; 610 611 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */ 612 613 static ssize_t proc_info_read(struct file * file, char __user * buf, 614 size_t count, loff_t *ppos) 615 { 616 struct inode * inode = file->f_path.dentry->d_inode; 617 unsigned long page; 618 ssize_t length; 619 struct task_struct *task = get_proc_task(inode); 620 621 length = -ESRCH; 622 if (!task) 623 goto out_no_task; 624 625 if (count > PROC_BLOCK_SIZE) 626 count = PROC_BLOCK_SIZE; 627 628 length = -ENOMEM; 629 if (!(page = __get_free_page(GFP_TEMPORARY))) 630 goto out; 631 632 length = PROC_I(inode)->op.proc_read(task, (char*)page); 633 634 if (length >= 0) 635 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length); 636 free_page(page); 637 out: 638 put_task_struct(task); 639 out_no_task: 640 return length; 641 } 642 643 static const struct file_operations proc_info_file_operations = { 644 .read = proc_info_read, 645 .llseek = generic_file_llseek, 646 }; 647 648 static int proc_single_show(struct seq_file *m, void *v) 649 { 650 struct inode *inode = m->private; 651 struct pid_namespace *ns; 652 struct pid *pid; 653 struct task_struct *task; 654 int ret; 655 656 ns = inode->i_sb->s_fs_info; 657 pid = proc_pid(inode); 658 task = get_pid_task(pid, PIDTYPE_PID); 659 if (!task) 660 return -ESRCH; 661 662 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 663 664 put_task_struct(task); 665 return ret; 666 } 667 668 static int proc_single_open(struct inode *inode, struct file *filp) 669 { 670 return single_open(filp, proc_single_show, inode); 671 } 672 673 static const struct file_operations proc_single_file_operations = { 674 .open = proc_single_open, 675 .read = seq_read, 676 .llseek = seq_lseek, 677 .release = single_release, 678 }; 679 680 static int mem_open(struct inode* inode, struct file* file) 681 { 682 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 683 struct mm_struct *mm; 684 685 if (!task) 686 return -ESRCH; 687 688 mm = mm_access(task, PTRACE_MODE_ATTACH); 689 put_task_struct(task); 690 691 if (IS_ERR(mm)) 692 return PTR_ERR(mm); 693 694 if (mm) { 695 /* ensure this mm_struct can't be freed */ 696 atomic_inc(&mm->mm_count); 697 /* but do not pin its memory */ 698 mmput(mm); 699 } 700 701 /* OK to pass negative loff_t, we can catch out-of-range */ 702 file->f_mode |= FMODE_UNSIGNED_OFFSET; 703 file->private_data = mm; 704 705 return 0; 706 } 707 708 static ssize_t mem_rw(struct file *file, char __user *buf, 709 size_t count, loff_t *ppos, int write) 710 { 711 struct mm_struct *mm = file->private_data; 712 unsigned long addr = *ppos; 713 ssize_t copied; 714 char *page; 715 716 if (!mm) 717 return 0; 718 719 page = (char *)__get_free_page(GFP_TEMPORARY); 720 if (!page) 721 return -ENOMEM; 722 723 copied = 0; 724 if (!atomic_inc_not_zero(&mm->mm_users)) 725 goto free; 726 727 while (count > 0) { 728 int this_len = min_t(int, count, PAGE_SIZE); 729 730 if (write && copy_from_user(page, buf, this_len)) { 731 copied = -EFAULT; 732 break; 733 } 734 735 this_len = access_remote_vm(mm, addr, page, this_len, write); 736 if (!this_len) { 737 if (!copied) 738 copied = -EIO; 739 break; 740 } 741 742 if (!write && copy_to_user(buf, page, this_len)) { 743 copied = -EFAULT; 744 break; 745 } 746 747 buf += this_len; 748 addr += this_len; 749 copied += this_len; 750 count -= this_len; 751 } 752 *ppos = addr; 753 754 mmput(mm); 755 free: 756 free_page((unsigned long) page); 757 return copied; 758 } 759 760 static ssize_t mem_read(struct file *file, char __user *buf, 761 size_t count, loff_t *ppos) 762 { 763 return mem_rw(file, buf, count, ppos, 0); 764 } 765 766 static ssize_t mem_write(struct file *file, const char __user *buf, 767 size_t count, loff_t *ppos) 768 { 769 return mem_rw(file, (char __user*)buf, count, ppos, 1); 770 } 771 772 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 773 { 774 switch (orig) { 775 case 0: 776 file->f_pos = offset; 777 break; 778 case 1: 779 file->f_pos += offset; 780 break; 781 default: 782 return -EINVAL; 783 } 784 force_successful_syscall_return(); 785 return file->f_pos; 786 } 787 788 static int mem_release(struct inode *inode, struct file *file) 789 { 790 struct mm_struct *mm = file->private_data; 791 if (mm) 792 mmdrop(mm); 793 return 0; 794 } 795 796 static const struct file_operations proc_mem_operations = { 797 .llseek = mem_lseek, 798 .read = mem_read, 799 .write = mem_write, 800 .open = mem_open, 801 .release = mem_release, 802 }; 803 804 static ssize_t environ_read(struct file *file, char __user *buf, 805 size_t count, loff_t *ppos) 806 { 807 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 808 char *page; 809 unsigned long src = *ppos; 810 int ret = -ESRCH; 811 struct mm_struct *mm; 812 813 if (!task) 814 goto out_no_task; 815 816 ret = -ENOMEM; 817 page = (char *)__get_free_page(GFP_TEMPORARY); 818 if (!page) 819 goto out; 820 821 822 mm = mm_for_maps(task); 823 ret = PTR_ERR(mm); 824 if (!mm || IS_ERR(mm)) 825 goto out_free; 826 827 ret = 0; 828 while (count > 0) { 829 int this_len, retval, max_len; 830 831 this_len = mm->env_end - (mm->env_start + src); 832 833 if (this_len <= 0) 834 break; 835 836 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 837 this_len = (this_len > max_len) ? max_len : this_len; 838 839 retval = access_process_vm(task, (mm->env_start + src), 840 page, this_len, 0); 841 842 if (retval <= 0) { 843 ret = retval; 844 break; 845 } 846 847 if (copy_to_user(buf, page, retval)) { 848 ret = -EFAULT; 849 break; 850 } 851 852 ret += retval; 853 src += retval; 854 buf += retval; 855 count -= retval; 856 } 857 *ppos = src; 858 859 mmput(mm); 860 out_free: 861 free_page((unsigned long) page); 862 out: 863 put_task_struct(task); 864 out_no_task: 865 return ret; 866 } 867 868 static const struct file_operations proc_environ_operations = { 869 .read = environ_read, 870 .llseek = generic_file_llseek, 871 }; 872 873 static ssize_t oom_adjust_read(struct file *file, char __user *buf, 874 size_t count, loff_t *ppos) 875 { 876 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 877 char buffer[PROC_NUMBUF]; 878 size_t len; 879 int oom_adjust = OOM_DISABLE; 880 unsigned long flags; 881 882 if (!task) 883 return -ESRCH; 884 885 if (lock_task_sighand(task, &flags)) { 886 oom_adjust = task->signal->oom_adj; 887 unlock_task_sighand(task, &flags); 888 } 889 890 put_task_struct(task); 891 892 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); 893 894 return simple_read_from_buffer(buf, count, ppos, buffer, len); 895 } 896 897 static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 898 size_t count, loff_t *ppos) 899 { 900 struct task_struct *task; 901 char buffer[PROC_NUMBUF]; 902 int oom_adjust; 903 unsigned long flags; 904 int err; 905 906 memset(buffer, 0, sizeof(buffer)); 907 if (count > sizeof(buffer) - 1) 908 count = sizeof(buffer) - 1; 909 if (copy_from_user(buffer, buf, count)) { 910 err = -EFAULT; 911 goto out; 912 } 913 914 err = kstrtoint(strstrip(buffer), 0, &oom_adjust); 915 if (err) 916 goto out; 917 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && 918 oom_adjust != OOM_DISABLE) { 919 err = -EINVAL; 920 goto out; 921 } 922 923 task = get_proc_task(file->f_path.dentry->d_inode); 924 if (!task) { 925 err = -ESRCH; 926 goto out; 927 } 928 929 task_lock(task); 930 if (!task->mm) { 931 err = -EINVAL; 932 goto err_task_lock; 933 } 934 935 if (!lock_task_sighand(task, &flags)) { 936 err = -ESRCH; 937 goto err_task_lock; 938 } 939 940 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) { 941 err = -EACCES; 942 goto err_sighand; 943 } 944 945 /* 946 * Warn that /proc/pid/oom_adj is deprecated, see 947 * Documentation/feature-removal-schedule.txt. 948 */ 949 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 950 current->comm, task_pid_nr(current), task_pid_nr(task), 951 task_pid_nr(task)); 952 task->signal->oom_adj = oom_adjust; 953 /* 954 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 955 * value is always attainable. 956 */ 957 if (task->signal->oom_adj == OOM_ADJUST_MAX) 958 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX; 959 else 960 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) / 961 -OOM_DISABLE; 962 trace_oom_score_adj_update(task); 963 err_sighand: 964 unlock_task_sighand(task, &flags); 965 err_task_lock: 966 task_unlock(task); 967 put_task_struct(task); 968 out: 969 return err < 0 ? err : count; 970 } 971 972 static const struct file_operations proc_oom_adjust_operations = { 973 .read = oom_adjust_read, 974 .write = oom_adjust_write, 975 .llseek = generic_file_llseek, 976 }; 977 978 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 979 size_t count, loff_t *ppos) 980 { 981 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 982 char buffer[PROC_NUMBUF]; 983 int oom_score_adj = OOM_SCORE_ADJ_MIN; 984 unsigned long flags; 985 size_t len; 986 987 if (!task) 988 return -ESRCH; 989 if (lock_task_sighand(task, &flags)) { 990 oom_score_adj = task->signal->oom_score_adj; 991 unlock_task_sighand(task, &flags); 992 } 993 put_task_struct(task); 994 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj); 995 return simple_read_from_buffer(buf, count, ppos, buffer, len); 996 } 997 998 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 999 size_t count, loff_t *ppos) 1000 { 1001 struct task_struct *task; 1002 char buffer[PROC_NUMBUF]; 1003 unsigned long flags; 1004 int oom_score_adj; 1005 int err; 1006 1007 memset(buffer, 0, sizeof(buffer)); 1008 if (count > sizeof(buffer) - 1) 1009 count = sizeof(buffer) - 1; 1010 if (copy_from_user(buffer, buf, count)) { 1011 err = -EFAULT; 1012 goto out; 1013 } 1014 1015 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 1016 if (err) 1017 goto out; 1018 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1019 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1020 err = -EINVAL; 1021 goto out; 1022 } 1023 1024 task = get_proc_task(file->f_path.dentry->d_inode); 1025 if (!task) { 1026 err = -ESRCH; 1027 goto out; 1028 } 1029 1030 task_lock(task); 1031 if (!task->mm) { 1032 err = -EINVAL; 1033 goto err_task_lock; 1034 } 1035 1036 if (!lock_task_sighand(task, &flags)) { 1037 err = -ESRCH; 1038 goto err_task_lock; 1039 } 1040 1041 if (oom_score_adj < task->signal->oom_score_adj_min && 1042 !capable(CAP_SYS_RESOURCE)) { 1043 err = -EACCES; 1044 goto err_sighand; 1045 } 1046 1047 task->signal->oom_score_adj = oom_score_adj; 1048 if (has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1049 task->signal->oom_score_adj_min = oom_score_adj; 1050 trace_oom_score_adj_update(task); 1051 /* 1052 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is 1053 * always attainable. 1054 */ 1055 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) 1056 task->signal->oom_adj = OOM_DISABLE; 1057 else 1058 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) / 1059 OOM_SCORE_ADJ_MAX; 1060 err_sighand: 1061 unlock_task_sighand(task, &flags); 1062 err_task_lock: 1063 task_unlock(task); 1064 put_task_struct(task); 1065 out: 1066 return err < 0 ? err : count; 1067 } 1068 1069 static const struct file_operations proc_oom_score_adj_operations = { 1070 .read = oom_score_adj_read, 1071 .write = oom_score_adj_write, 1072 .llseek = default_llseek, 1073 }; 1074 1075 #ifdef CONFIG_AUDITSYSCALL 1076 #define TMPBUFLEN 21 1077 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1078 size_t count, loff_t *ppos) 1079 { 1080 struct inode * inode = file->f_path.dentry->d_inode; 1081 struct task_struct *task = get_proc_task(inode); 1082 ssize_t length; 1083 char tmpbuf[TMPBUFLEN]; 1084 1085 if (!task) 1086 return -ESRCH; 1087 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1088 audit_get_loginuid(task)); 1089 put_task_struct(task); 1090 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1091 } 1092 1093 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1094 size_t count, loff_t *ppos) 1095 { 1096 struct inode * inode = file->f_path.dentry->d_inode; 1097 char *page, *tmp; 1098 ssize_t length; 1099 uid_t loginuid; 1100 1101 rcu_read_lock(); 1102 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1103 rcu_read_unlock(); 1104 return -EPERM; 1105 } 1106 rcu_read_unlock(); 1107 1108 if (count >= PAGE_SIZE) 1109 count = PAGE_SIZE - 1; 1110 1111 if (*ppos != 0) { 1112 /* No partial writes. */ 1113 return -EINVAL; 1114 } 1115 page = (char*)__get_free_page(GFP_TEMPORARY); 1116 if (!page) 1117 return -ENOMEM; 1118 length = -EFAULT; 1119 if (copy_from_user(page, buf, count)) 1120 goto out_free_page; 1121 1122 page[count] = '\0'; 1123 loginuid = simple_strtoul(page, &tmp, 10); 1124 if (tmp == page) { 1125 length = -EINVAL; 1126 goto out_free_page; 1127 1128 } 1129 length = audit_set_loginuid(loginuid); 1130 if (likely(length == 0)) 1131 length = count; 1132 1133 out_free_page: 1134 free_page((unsigned long) page); 1135 return length; 1136 } 1137 1138 static const struct file_operations proc_loginuid_operations = { 1139 .read = proc_loginuid_read, 1140 .write = proc_loginuid_write, 1141 .llseek = generic_file_llseek, 1142 }; 1143 1144 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1145 size_t count, loff_t *ppos) 1146 { 1147 struct inode * inode = file->f_path.dentry->d_inode; 1148 struct task_struct *task = get_proc_task(inode); 1149 ssize_t length; 1150 char tmpbuf[TMPBUFLEN]; 1151 1152 if (!task) 1153 return -ESRCH; 1154 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1155 audit_get_sessionid(task)); 1156 put_task_struct(task); 1157 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1158 } 1159 1160 static const struct file_operations proc_sessionid_operations = { 1161 .read = proc_sessionid_read, 1162 .llseek = generic_file_llseek, 1163 }; 1164 #endif 1165 1166 #ifdef CONFIG_FAULT_INJECTION 1167 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1168 size_t count, loff_t *ppos) 1169 { 1170 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1171 char buffer[PROC_NUMBUF]; 1172 size_t len; 1173 int make_it_fail; 1174 1175 if (!task) 1176 return -ESRCH; 1177 make_it_fail = task->make_it_fail; 1178 put_task_struct(task); 1179 1180 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1181 1182 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1183 } 1184 1185 static ssize_t proc_fault_inject_write(struct file * file, 1186 const char __user * buf, size_t count, loff_t *ppos) 1187 { 1188 struct task_struct *task; 1189 char buffer[PROC_NUMBUF], *end; 1190 int make_it_fail; 1191 1192 if (!capable(CAP_SYS_RESOURCE)) 1193 return -EPERM; 1194 memset(buffer, 0, sizeof(buffer)); 1195 if (count > sizeof(buffer) - 1) 1196 count = sizeof(buffer) - 1; 1197 if (copy_from_user(buffer, buf, count)) 1198 return -EFAULT; 1199 make_it_fail = simple_strtol(strstrip(buffer), &end, 0); 1200 if (*end) 1201 return -EINVAL; 1202 task = get_proc_task(file->f_dentry->d_inode); 1203 if (!task) 1204 return -ESRCH; 1205 task->make_it_fail = make_it_fail; 1206 put_task_struct(task); 1207 1208 return count; 1209 } 1210 1211 static const struct file_operations proc_fault_inject_operations = { 1212 .read = proc_fault_inject_read, 1213 .write = proc_fault_inject_write, 1214 .llseek = generic_file_llseek, 1215 }; 1216 #endif 1217 1218 1219 #ifdef CONFIG_SCHED_DEBUG 1220 /* 1221 * Print out various scheduling related per-task fields: 1222 */ 1223 static int sched_show(struct seq_file *m, void *v) 1224 { 1225 struct inode *inode = m->private; 1226 struct task_struct *p; 1227 1228 p = get_proc_task(inode); 1229 if (!p) 1230 return -ESRCH; 1231 proc_sched_show_task(p, m); 1232 1233 put_task_struct(p); 1234 1235 return 0; 1236 } 1237 1238 static ssize_t 1239 sched_write(struct file *file, const char __user *buf, 1240 size_t count, loff_t *offset) 1241 { 1242 struct inode *inode = file->f_path.dentry->d_inode; 1243 struct task_struct *p; 1244 1245 p = get_proc_task(inode); 1246 if (!p) 1247 return -ESRCH; 1248 proc_sched_set_task(p); 1249 1250 put_task_struct(p); 1251 1252 return count; 1253 } 1254 1255 static int sched_open(struct inode *inode, struct file *filp) 1256 { 1257 return single_open(filp, sched_show, inode); 1258 } 1259 1260 static const struct file_operations proc_pid_sched_operations = { 1261 .open = sched_open, 1262 .read = seq_read, 1263 .write = sched_write, 1264 .llseek = seq_lseek, 1265 .release = single_release, 1266 }; 1267 1268 #endif 1269 1270 #ifdef CONFIG_SCHED_AUTOGROUP 1271 /* 1272 * Print out autogroup related information: 1273 */ 1274 static int sched_autogroup_show(struct seq_file *m, void *v) 1275 { 1276 struct inode *inode = m->private; 1277 struct task_struct *p; 1278 1279 p = get_proc_task(inode); 1280 if (!p) 1281 return -ESRCH; 1282 proc_sched_autogroup_show_task(p, m); 1283 1284 put_task_struct(p); 1285 1286 return 0; 1287 } 1288 1289 static ssize_t 1290 sched_autogroup_write(struct file *file, const char __user *buf, 1291 size_t count, loff_t *offset) 1292 { 1293 struct inode *inode = file->f_path.dentry->d_inode; 1294 struct task_struct *p; 1295 char buffer[PROC_NUMBUF]; 1296 int nice; 1297 int err; 1298 1299 memset(buffer, 0, sizeof(buffer)); 1300 if (count > sizeof(buffer) - 1) 1301 count = sizeof(buffer) - 1; 1302 if (copy_from_user(buffer, buf, count)) 1303 return -EFAULT; 1304 1305 err = kstrtoint(strstrip(buffer), 0, &nice); 1306 if (err < 0) 1307 return err; 1308 1309 p = get_proc_task(inode); 1310 if (!p) 1311 return -ESRCH; 1312 1313 err = nice; 1314 err = proc_sched_autogroup_set_nice(p, &err); 1315 if (err) 1316 count = err; 1317 1318 put_task_struct(p); 1319 1320 return count; 1321 } 1322 1323 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1324 { 1325 int ret; 1326 1327 ret = single_open(filp, sched_autogroup_show, NULL); 1328 if (!ret) { 1329 struct seq_file *m = filp->private_data; 1330 1331 m->private = inode; 1332 } 1333 return ret; 1334 } 1335 1336 static const struct file_operations proc_pid_sched_autogroup_operations = { 1337 .open = sched_autogroup_open, 1338 .read = seq_read, 1339 .write = sched_autogroup_write, 1340 .llseek = seq_lseek, 1341 .release = single_release, 1342 }; 1343 1344 #endif /* CONFIG_SCHED_AUTOGROUP */ 1345 1346 static ssize_t comm_write(struct file *file, const char __user *buf, 1347 size_t count, loff_t *offset) 1348 { 1349 struct inode *inode = file->f_path.dentry->d_inode; 1350 struct task_struct *p; 1351 char buffer[TASK_COMM_LEN]; 1352 1353 memset(buffer, 0, sizeof(buffer)); 1354 if (count > sizeof(buffer) - 1) 1355 count = sizeof(buffer) - 1; 1356 if (copy_from_user(buffer, buf, count)) 1357 return -EFAULT; 1358 1359 p = get_proc_task(inode); 1360 if (!p) 1361 return -ESRCH; 1362 1363 if (same_thread_group(current, p)) 1364 set_task_comm(p, buffer); 1365 else 1366 count = -EINVAL; 1367 1368 put_task_struct(p); 1369 1370 return count; 1371 } 1372 1373 static int comm_show(struct seq_file *m, void *v) 1374 { 1375 struct inode *inode = m->private; 1376 struct task_struct *p; 1377 1378 p = get_proc_task(inode); 1379 if (!p) 1380 return -ESRCH; 1381 1382 task_lock(p); 1383 seq_printf(m, "%s\n", p->comm); 1384 task_unlock(p); 1385 1386 put_task_struct(p); 1387 1388 return 0; 1389 } 1390 1391 static int comm_open(struct inode *inode, struct file *filp) 1392 { 1393 return single_open(filp, comm_show, inode); 1394 } 1395 1396 static const struct file_operations proc_pid_set_comm_operations = { 1397 .open = comm_open, 1398 .read = seq_read, 1399 .write = comm_write, 1400 .llseek = seq_lseek, 1401 .release = single_release, 1402 }; 1403 1404 static int proc_exe_link(struct dentry *dentry, struct path *exe_path) 1405 { 1406 struct task_struct *task; 1407 struct mm_struct *mm; 1408 struct file *exe_file; 1409 1410 task = get_proc_task(dentry->d_inode); 1411 if (!task) 1412 return -ENOENT; 1413 mm = get_task_mm(task); 1414 put_task_struct(task); 1415 if (!mm) 1416 return -ENOENT; 1417 exe_file = get_mm_exe_file(mm); 1418 mmput(mm); 1419 if (exe_file) { 1420 *exe_path = exe_file->f_path; 1421 path_get(&exe_file->f_path); 1422 fput(exe_file); 1423 return 0; 1424 } else 1425 return -ENOENT; 1426 } 1427 1428 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1429 { 1430 struct inode *inode = dentry->d_inode; 1431 int error = -EACCES; 1432 1433 /* We don't need a base pointer in the /proc filesystem */ 1434 path_put(&nd->path); 1435 1436 /* Are we allowed to snoop on the tasks file descriptors? */ 1437 if (!proc_fd_access_allowed(inode)) 1438 goto out; 1439 1440 error = PROC_I(inode)->op.proc_get_link(dentry, &nd->path); 1441 out: 1442 return ERR_PTR(error); 1443 } 1444 1445 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1446 { 1447 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1448 char *pathname; 1449 int len; 1450 1451 if (!tmp) 1452 return -ENOMEM; 1453 1454 pathname = d_path(path, tmp, PAGE_SIZE); 1455 len = PTR_ERR(pathname); 1456 if (IS_ERR(pathname)) 1457 goto out; 1458 len = tmp + PAGE_SIZE - 1 - pathname; 1459 1460 if (len > buflen) 1461 len = buflen; 1462 if (copy_to_user(buffer, pathname, len)) 1463 len = -EFAULT; 1464 out: 1465 free_page((unsigned long)tmp); 1466 return len; 1467 } 1468 1469 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1470 { 1471 int error = -EACCES; 1472 struct inode *inode = dentry->d_inode; 1473 struct path path; 1474 1475 /* Are we allowed to snoop on the tasks file descriptors? */ 1476 if (!proc_fd_access_allowed(inode)) 1477 goto out; 1478 1479 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1480 if (error) 1481 goto out; 1482 1483 error = do_proc_readlink(&path, buffer, buflen); 1484 path_put(&path); 1485 out: 1486 return error; 1487 } 1488 1489 static const struct inode_operations proc_pid_link_inode_operations = { 1490 .readlink = proc_pid_readlink, 1491 .follow_link = proc_pid_follow_link, 1492 .setattr = proc_setattr, 1493 }; 1494 1495 1496 /* building an inode */ 1497 1498 static int task_dumpable(struct task_struct *task) 1499 { 1500 int dumpable = 0; 1501 struct mm_struct *mm; 1502 1503 task_lock(task); 1504 mm = task->mm; 1505 if (mm) 1506 dumpable = get_dumpable(mm); 1507 task_unlock(task); 1508 if(dumpable == 1) 1509 return 1; 1510 return 0; 1511 } 1512 1513 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1514 { 1515 struct inode * inode; 1516 struct proc_inode *ei; 1517 const struct cred *cred; 1518 1519 /* We need a new inode */ 1520 1521 inode = new_inode(sb); 1522 if (!inode) 1523 goto out; 1524 1525 /* Common stuff */ 1526 ei = PROC_I(inode); 1527 inode->i_ino = get_next_ino(); 1528 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1529 inode->i_op = &proc_def_inode_operations; 1530 1531 /* 1532 * grab the reference to task. 1533 */ 1534 ei->pid = get_task_pid(task, PIDTYPE_PID); 1535 if (!ei->pid) 1536 goto out_unlock; 1537 1538 if (task_dumpable(task)) { 1539 rcu_read_lock(); 1540 cred = __task_cred(task); 1541 inode->i_uid = cred->euid; 1542 inode->i_gid = cred->egid; 1543 rcu_read_unlock(); 1544 } 1545 security_task_to_inode(task, inode); 1546 1547 out: 1548 return inode; 1549 1550 out_unlock: 1551 iput(inode); 1552 return NULL; 1553 } 1554 1555 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1556 { 1557 struct inode *inode = dentry->d_inode; 1558 struct task_struct *task; 1559 const struct cred *cred; 1560 struct pid_namespace *pid = dentry->d_sb->s_fs_info; 1561 1562 generic_fillattr(inode, stat); 1563 1564 rcu_read_lock(); 1565 stat->uid = 0; 1566 stat->gid = 0; 1567 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1568 if (task) { 1569 if (!has_pid_permissions(pid, task, 2)) { 1570 rcu_read_unlock(); 1571 /* 1572 * This doesn't prevent learning whether PID exists, 1573 * it only makes getattr() consistent with readdir(). 1574 */ 1575 return -ENOENT; 1576 } 1577 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1578 task_dumpable(task)) { 1579 cred = __task_cred(task); 1580 stat->uid = cred->euid; 1581 stat->gid = cred->egid; 1582 } 1583 } 1584 rcu_read_unlock(); 1585 return 0; 1586 } 1587 1588 /* dentry stuff */ 1589 1590 /* 1591 * Exceptional case: normally we are not allowed to unhash a busy 1592 * directory. In this case, however, we can do it - no aliasing problems 1593 * due to the way we treat inodes. 1594 * 1595 * Rewrite the inode's ownerships here because the owning task may have 1596 * performed a setuid(), etc. 1597 * 1598 * Before the /proc/pid/status file was created the only way to read 1599 * the effective uid of a /process was to stat /proc/pid. Reading 1600 * /proc/pid/status is slow enough that procps and other packages 1601 * kept stating /proc/pid. To keep the rules in /proc simple I have 1602 * made this apply to all per process world readable and executable 1603 * directories. 1604 */ 1605 int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1606 { 1607 struct inode *inode; 1608 struct task_struct *task; 1609 const struct cred *cred; 1610 1611 if (nd && nd->flags & LOOKUP_RCU) 1612 return -ECHILD; 1613 1614 inode = dentry->d_inode; 1615 task = get_proc_task(inode); 1616 1617 if (task) { 1618 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1619 task_dumpable(task)) { 1620 rcu_read_lock(); 1621 cred = __task_cred(task); 1622 inode->i_uid = cred->euid; 1623 inode->i_gid = cred->egid; 1624 rcu_read_unlock(); 1625 } else { 1626 inode->i_uid = 0; 1627 inode->i_gid = 0; 1628 } 1629 inode->i_mode &= ~(S_ISUID | S_ISGID); 1630 security_task_to_inode(task, inode); 1631 put_task_struct(task); 1632 return 1; 1633 } 1634 d_drop(dentry); 1635 return 0; 1636 } 1637 1638 static int pid_delete_dentry(const struct dentry * dentry) 1639 { 1640 /* Is the task we represent dead? 1641 * If so, then don't put the dentry on the lru list, 1642 * kill it immediately. 1643 */ 1644 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1645 } 1646 1647 const struct dentry_operations pid_dentry_operations = 1648 { 1649 .d_revalidate = pid_revalidate, 1650 .d_delete = pid_delete_dentry, 1651 }; 1652 1653 /* Lookups */ 1654 1655 /* 1656 * Fill a directory entry. 1657 * 1658 * If possible create the dcache entry and derive our inode number and 1659 * file type from dcache entry. 1660 * 1661 * Since all of the proc inode numbers are dynamically generated, the inode 1662 * numbers do not exist until the inode is cache. This means creating the 1663 * the dcache entry in readdir is necessary to keep the inode numbers 1664 * reported by readdir in sync with the inode numbers reported 1665 * by stat. 1666 */ 1667 int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1668 const char *name, int len, 1669 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1670 { 1671 struct dentry *child, *dir = filp->f_path.dentry; 1672 struct inode *inode; 1673 struct qstr qname; 1674 ino_t ino = 0; 1675 unsigned type = DT_UNKNOWN; 1676 1677 qname.name = name; 1678 qname.len = len; 1679 qname.hash = full_name_hash(name, len); 1680 1681 child = d_lookup(dir, &qname); 1682 if (!child) { 1683 struct dentry *new; 1684 new = d_alloc(dir, &qname); 1685 if (new) { 1686 child = instantiate(dir->d_inode, new, task, ptr); 1687 if (child) 1688 dput(new); 1689 else 1690 child = new; 1691 } 1692 } 1693 if (!child || IS_ERR(child) || !child->d_inode) 1694 goto end_instantiate; 1695 inode = child->d_inode; 1696 if (inode) { 1697 ino = inode->i_ino; 1698 type = inode->i_mode >> 12; 1699 } 1700 dput(child); 1701 end_instantiate: 1702 if (!ino) 1703 ino = find_inode_number(dir, &qname); 1704 if (!ino) 1705 ino = 1; 1706 return filldir(dirent, name, len, filp->f_pos, ino, type); 1707 } 1708 1709 static unsigned name_to_int(struct dentry *dentry) 1710 { 1711 const char *name = dentry->d_name.name; 1712 int len = dentry->d_name.len; 1713 unsigned n = 0; 1714 1715 if (len > 1 && *name == '0') 1716 goto out; 1717 while (len-- > 0) { 1718 unsigned c = *name++ - '0'; 1719 if (c > 9) 1720 goto out; 1721 if (n >= (~0U-9)/10) 1722 goto out; 1723 n *= 10; 1724 n += c; 1725 } 1726 return n; 1727 out: 1728 return ~0U; 1729 } 1730 1731 #define PROC_FDINFO_MAX 64 1732 1733 static int proc_fd_info(struct inode *inode, struct path *path, char *info) 1734 { 1735 struct task_struct *task = get_proc_task(inode); 1736 struct files_struct *files = NULL; 1737 struct file *file; 1738 int fd = proc_fd(inode); 1739 1740 if (task) { 1741 files = get_files_struct(task); 1742 put_task_struct(task); 1743 } 1744 if (files) { 1745 /* 1746 * We are not taking a ref to the file structure, so we must 1747 * hold ->file_lock. 1748 */ 1749 spin_lock(&files->file_lock); 1750 file = fcheck_files(files, fd); 1751 if (file) { 1752 unsigned int f_flags; 1753 struct fdtable *fdt; 1754 1755 fdt = files_fdtable(files); 1756 f_flags = file->f_flags & ~O_CLOEXEC; 1757 if (FD_ISSET(fd, fdt->close_on_exec)) 1758 f_flags |= O_CLOEXEC; 1759 1760 if (path) { 1761 *path = file->f_path; 1762 path_get(&file->f_path); 1763 } 1764 if (info) 1765 snprintf(info, PROC_FDINFO_MAX, 1766 "pos:\t%lli\n" 1767 "flags:\t0%o\n", 1768 (long long) file->f_pos, 1769 f_flags); 1770 spin_unlock(&files->file_lock); 1771 put_files_struct(files); 1772 return 0; 1773 } 1774 spin_unlock(&files->file_lock); 1775 put_files_struct(files); 1776 } 1777 return -ENOENT; 1778 } 1779 1780 static int proc_fd_link(struct dentry *dentry, struct path *path) 1781 { 1782 return proc_fd_info(dentry->d_inode, path, NULL); 1783 } 1784 1785 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1786 { 1787 struct inode *inode; 1788 struct task_struct *task; 1789 int fd; 1790 struct files_struct *files; 1791 const struct cred *cred; 1792 1793 if (nd && nd->flags & LOOKUP_RCU) 1794 return -ECHILD; 1795 1796 inode = dentry->d_inode; 1797 task = get_proc_task(inode); 1798 fd = proc_fd(inode); 1799 1800 if (task) { 1801 files = get_files_struct(task); 1802 if (files) { 1803 rcu_read_lock(); 1804 if (fcheck_files(files, fd)) { 1805 rcu_read_unlock(); 1806 put_files_struct(files); 1807 if (task_dumpable(task)) { 1808 rcu_read_lock(); 1809 cred = __task_cred(task); 1810 inode->i_uid = cred->euid; 1811 inode->i_gid = cred->egid; 1812 rcu_read_unlock(); 1813 } else { 1814 inode->i_uid = 0; 1815 inode->i_gid = 0; 1816 } 1817 inode->i_mode &= ~(S_ISUID | S_ISGID); 1818 security_task_to_inode(task, inode); 1819 put_task_struct(task); 1820 return 1; 1821 } 1822 rcu_read_unlock(); 1823 put_files_struct(files); 1824 } 1825 put_task_struct(task); 1826 } 1827 d_drop(dentry); 1828 return 0; 1829 } 1830 1831 static const struct dentry_operations tid_fd_dentry_operations = 1832 { 1833 .d_revalidate = tid_fd_revalidate, 1834 .d_delete = pid_delete_dentry, 1835 }; 1836 1837 static struct dentry *proc_fd_instantiate(struct inode *dir, 1838 struct dentry *dentry, struct task_struct *task, const void *ptr) 1839 { 1840 unsigned fd = *(const unsigned *)ptr; 1841 struct file *file; 1842 struct files_struct *files; 1843 struct inode *inode; 1844 struct proc_inode *ei; 1845 struct dentry *error = ERR_PTR(-ENOENT); 1846 1847 inode = proc_pid_make_inode(dir->i_sb, task); 1848 if (!inode) 1849 goto out; 1850 ei = PROC_I(inode); 1851 ei->fd = fd; 1852 files = get_files_struct(task); 1853 if (!files) 1854 goto out_iput; 1855 inode->i_mode = S_IFLNK; 1856 1857 /* 1858 * We are not taking a ref to the file structure, so we must 1859 * hold ->file_lock. 1860 */ 1861 spin_lock(&files->file_lock); 1862 file = fcheck_files(files, fd); 1863 if (!file) 1864 goto out_unlock; 1865 if (file->f_mode & FMODE_READ) 1866 inode->i_mode |= S_IRUSR | S_IXUSR; 1867 if (file->f_mode & FMODE_WRITE) 1868 inode->i_mode |= S_IWUSR | S_IXUSR; 1869 spin_unlock(&files->file_lock); 1870 put_files_struct(files); 1871 1872 inode->i_op = &proc_pid_link_inode_operations; 1873 inode->i_size = 64; 1874 ei->op.proc_get_link = proc_fd_link; 1875 d_set_d_op(dentry, &tid_fd_dentry_operations); 1876 d_add(dentry, inode); 1877 /* Close the race of the process dying before we return the dentry */ 1878 if (tid_fd_revalidate(dentry, NULL)) 1879 error = NULL; 1880 1881 out: 1882 return error; 1883 out_unlock: 1884 spin_unlock(&files->file_lock); 1885 put_files_struct(files); 1886 out_iput: 1887 iput(inode); 1888 goto out; 1889 } 1890 1891 static struct dentry *proc_lookupfd_common(struct inode *dir, 1892 struct dentry *dentry, 1893 instantiate_t instantiate) 1894 { 1895 struct task_struct *task = get_proc_task(dir); 1896 unsigned fd = name_to_int(dentry); 1897 struct dentry *result = ERR_PTR(-ENOENT); 1898 1899 if (!task) 1900 goto out_no_task; 1901 if (fd == ~0U) 1902 goto out; 1903 1904 result = instantiate(dir, dentry, task, &fd); 1905 out: 1906 put_task_struct(task); 1907 out_no_task: 1908 return result; 1909 } 1910 1911 static int proc_readfd_common(struct file * filp, void * dirent, 1912 filldir_t filldir, instantiate_t instantiate) 1913 { 1914 struct dentry *dentry = filp->f_path.dentry; 1915 struct inode *inode = dentry->d_inode; 1916 struct task_struct *p = get_proc_task(inode); 1917 unsigned int fd, ino; 1918 int retval; 1919 struct files_struct * files; 1920 1921 retval = -ENOENT; 1922 if (!p) 1923 goto out_no_task; 1924 retval = 0; 1925 1926 fd = filp->f_pos; 1927 switch (fd) { 1928 case 0: 1929 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 1930 goto out; 1931 filp->f_pos++; 1932 case 1: 1933 ino = parent_ino(dentry); 1934 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 1935 goto out; 1936 filp->f_pos++; 1937 default: 1938 files = get_files_struct(p); 1939 if (!files) 1940 goto out; 1941 rcu_read_lock(); 1942 for (fd = filp->f_pos-2; 1943 fd < files_fdtable(files)->max_fds; 1944 fd++, filp->f_pos++) { 1945 char name[PROC_NUMBUF]; 1946 int len; 1947 1948 if (!fcheck_files(files, fd)) 1949 continue; 1950 rcu_read_unlock(); 1951 1952 len = snprintf(name, sizeof(name), "%d", fd); 1953 if (proc_fill_cache(filp, dirent, filldir, 1954 name, len, instantiate, 1955 p, &fd) < 0) { 1956 rcu_read_lock(); 1957 break; 1958 } 1959 rcu_read_lock(); 1960 } 1961 rcu_read_unlock(); 1962 put_files_struct(files); 1963 } 1964 out: 1965 put_task_struct(p); 1966 out_no_task: 1967 return retval; 1968 } 1969 1970 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 1971 struct nameidata *nd) 1972 { 1973 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 1974 } 1975 1976 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 1977 { 1978 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 1979 } 1980 1981 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 1982 size_t len, loff_t *ppos) 1983 { 1984 char tmp[PROC_FDINFO_MAX]; 1985 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); 1986 if (!err) 1987 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 1988 return err; 1989 } 1990 1991 static const struct file_operations proc_fdinfo_file_operations = { 1992 .open = nonseekable_open, 1993 .read = proc_fdinfo_read, 1994 .llseek = no_llseek, 1995 }; 1996 1997 static const struct file_operations proc_fd_operations = { 1998 .read = generic_read_dir, 1999 .readdir = proc_readfd, 2000 .llseek = default_llseek, 2001 }; 2002 2003 #ifdef CONFIG_CHECKPOINT_RESTORE 2004 2005 /* 2006 * dname_to_vma_addr - maps a dentry name into two unsigned longs 2007 * which represent vma start and end addresses. 2008 */ 2009 static int dname_to_vma_addr(struct dentry *dentry, 2010 unsigned long *start, unsigned long *end) 2011 { 2012 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2) 2013 return -EINVAL; 2014 2015 return 0; 2016 } 2017 2018 static int map_files_d_revalidate(struct dentry *dentry, struct nameidata *nd) 2019 { 2020 unsigned long vm_start, vm_end; 2021 bool exact_vma_exists = false; 2022 struct mm_struct *mm = NULL; 2023 struct task_struct *task; 2024 const struct cred *cred; 2025 struct inode *inode; 2026 int status = 0; 2027 2028 if (nd && nd->flags & LOOKUP_RCU) 2029 return -ECHILD; 2030 2031 if (!capable(CAP_SYS_ADMIN)) { 2032 status = -EACCES; 2033 goto out_notask; 2034 } 2035 2036 inode = dentry->d_inode; 2037 task = get_proc_task(inode); 2038 if (!task) 2039 goto out_notask; 2040 2041 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 2042 goto out; 2043 2044 mm = get_task_mm(task); 2045 if (!mm) 2046 goto out; 2047 2048 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 2049 down_read(&mm->mmap_sem); 2050 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end); 2051 up_read(&mm->mmap_sem); 2052 } 2053 2054 mmput(mm); 2055 2056 if (exact_vma_exists) { 2057 if (task_dumpable(task)) { 2058 rcu_read_lock(); 2059 cred = __task_cred(task); 2060 inode->i_uid = cred->euid; 2061 inode->i_gid = cred->egid; 2062 rcu_read_unlock(); 2063 } else { 2064 inode->i_uid = 0; 2065 inode->i_gid = 0; 2066 } 2067 security_task_to_inode(task, inode); 2068 status = 1; 2069 } 2070 2071 out: 2072 put_task_struct(task); 2073 2074 out_notask: 2075 if (status <= 0) 2076 d_drop(dentry); 2077 2078 return status; 2079 } 2080 2081 static const struct dentry_operations tid_map_files_dentry_operations = { 2082 .d_revalidate = map_files_d_revalidate, 2083 .d_delete = pid_delete_dentry, 2084 }; 2085 2086 static int proc_map_files_get_link(struct dentry *dentry, struct path *path) 2087 { 2088 unsigned long vm_start, vm_end; 2089 struct vm_area_struct *vma; 2090 struct task_struct *task; 2091 struct mm_struct *mm; 2092 int rc; 2093 2094 rc = -ENOENT; 2095 task = get_proc_task(dentry->d_inode); 2096 if (!task) 2097 goto out; 2098 2099 mm = get_task_mm(task); 2100 put_task_struct(task); 2101 if (!mm) 2102 goto out; 2103 2104 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 2105 if (rc) 2106 goto out_mmput; 2107 2108 down_read(&mm->mmap_sem); 2109 vma = find_exact_vma(mm, vm_start, vm_end); 2110 if (vma && vma->vm_file) { 2111 *path = vma->vm_file->f_path; 2112 path_get(path); 2113 rc = 0; 2114 } 2115 up_read(&mm->mmap_sem); 2116 2117 out_mmput: 2118 mmput(mm); 2119 out: 2120 return rc; 2121 } 2122 2123 struct map_files_info { 2124 struct file *file; 2125 unsigned long len; 2126 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */ 2127 }; 2128 2129 static struct dentry * 2130 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry, 2131 struct task_struct *task, const void *ptr) 2132 { 2133 const struct file *file = ptr; 2134 struct proc_inode *ei; 2135 struct inode *inode; 2136 2137 if (!file) 2138 return ERR_PTR(-ENOENT); 2139 2140 inode = proc_pid_make_inode(dir->i_sb, task); 2141 if (!inode) 2142 return ERR_PTR(-ENOENT); 2143 2144 ei = PROC_I(inode); 2145 ei->op.proc_get_link = proc_map_files_get_link; 2146 2147 inode->i_op = &proc_pid_link_inode_operations; 2148 inode->i_size = 64; 2149 inode->i_mode = S_IFLNK; 2150 2151 if (file->f_mode & FMODE_READ) 2152 inode->i_mode |= S_IRUSR; 2153 if (file->f_mode & FMODE_WRITE) 2154 inode->i_mode |= S_IWUSR; 2155 2156 d_set_d_op(dentry, &tid_map_files_dentry_operations); 2157 d_add(dentry, inode); 2158 2159 return NULL; 2160 } 2161 2162 static struct dentry *proc_map_files_lookup(struct inode *dir, 2163 struct dentry *dentry, struct nameidata *nd) 2164 { 2165 unsigned long vm_start, vm_end; 2166 struct vm_area_struct *vma; 2167 struct task_struct *task; 2168 struct dentry *result; 2169 struct mm_struct *mm; 2170 2171 result = ERR_PTR(-EACCES); 2172 if (!capable(CAP_SYS_ADMIN)) 2173 goto out; 2174 2175 result = ERR_PTR(-ENOENT); 2176 task = get_proc_task(dir); 2177 if (!task) 2178 goto out; 2179 2180 result = ERR_PTR(-EACCES); 2181 if (lock_trace(task)) 2182 goto out_put_task; 2183 2184 result = ERR_PTR(-ENOENT); 2185 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 2186 goto out_unlock; 2187 2188 mm = get_task_mm(task); 2189 if (!mm) 2190 goto out_unlock; 2191 2192 down_read(&mm->mmap_sem); 2193 vma = find_exact_vma(mm, vm_start, vm_end); 2194 if (!vma) 2195 goto out_no_vma; 2196 2197 result = proc_map_files_instantiate(dir, dentry, task, vma->vm_file); 2198 2199 out_no_vma: 2200 up_read(&mm->mmap_sem); 2201 mmput(mm); 2202 out_unlock: 2203 unlock_trace(task); 2204 out_put_task: 2205 put_task_struct(task); 2206 out: 2207 return result; 2208 } 2209 2210 static const struct inode_operations proc_map_files_inode_operations = { 2211 .lookup = proc_map_files_lookup, 2212 .permission = proc_fd_permission, 2213 .setattr = proc_setattr, 2214 }; 2215 2216 static int 2217 proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir) 2218 { 2219 struct dentry *dentry = filp->f_path.dentry; 2220 struct inode *inode = dentry->d_inode; 2221 struct vm_area_struct *vma; 2222 struct task_struct *task; 2223 struct mm_struct *mm; 2224 ino_t ino; 2225 int ret; 2226 2227 ret = -EACCES; 2228 if (!capable(CAP_SYS_ADMIN)) 2229 goto out; 2230 2231 ret = -ENOENT; 2232 task = get_proc_task(inode); 2233 if (!task) 2234 goto out; 2235 2236 ret = -EACCES; 2237 if (lock_trace(task)) 2238 goto out_put_task; 2239 2240 ret = 0; 2241 switch (filp->f_pos) { 2242 case 0: 2243 ino = inode->i_ino; 2244 if (filldir(dirent, ".", 1, 0, ino, DT_DIR) < 0) 2245 goto out_unlock; 2246 filp->f_pos++; 2247 case 1: 2248 ino = parent_ino(dentry); 2249 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 2250 goto out_unlock; 2251 filp->f_pos++; 2252 default: 2253 { 2254 unsigned long nr_files, pos, i; 2255 struct flex_array *fa = NULL; 2256 struct map_files_info info; 2257 struct map_files_info *p; 2258 2259 mm = get_task_mm(task); 2260 if (!mm) 2261 goto out_unlock; 2262 down_read(&mm->mmap_sem); 2263 2264 nr_files = 0; 2265 2266 /* 2267 * We need two passes here: 2268 * 2269 * 1) Collect vmas of mapped files with mmap_sem taken 2270 * 2) Release mmap_sem and instantiate entries 2271 * 2272 * otherwise we get lockdep complained, since filldir() 2273 * routine might require mmap_sem taken in might_fault(). 2274 */ 2275 2276 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 2277 if (vma->vm_file && ++pos > filp->f_pos) 2278 nr_files++; 2279 } 2280 2281 if (nr_files) { 2282 fa = flex_array_alloc(sizeof(info), nr_files, 2283 GFP_KERNEL); 2284 if (!fa || flex_array_prealloc(fa, 0, nr_files, 2285 GFP_KERNEL)) { 2286 ret = -ENOMEM; 2287 if (fa) 2288 flex_array_free(fa); 2289 up_read(&mm->mmap_sem); 2290 mmput(mm); 2291 goto out_unlock; 2292 } 2293 for (i = 0, vma = mm->mmap, pos = 2; vma; 2294 vma = vma->vm_next) { 2295 if (!vma->vm_file) 2296 continue; 2297 if (++pos <= filp->f_pos) 2298 continue; 2299 2300 get_file(vma->vm_file); 2301 info.file = vma->vm_file; 2302 info.len = snprintf(info.name, 2303 sizeof(info.name), "%lx-%lx", 2304 vma->vm_start, vma->vm_end); 2305 if (flex_array_put(fa, i++, &info, GFP_KERNEL)) 2306 BUG(); 2307 } 2308 } 2309 up_read(&mm->mmap_sem); 2310 2311 for (i = 0; i < nr_files; i++) { 2312 p = flex_array_get(fa, i); 2313 ret = proc_fill_cache(filp, dirent, filldir, 2314 p->name, p->len, 2315 proc_map_files_instantiate, 2316 task, p->file); 2317 if (ret) 2318 break; 2319 filp->f_pos++; 2320 fput(p->file); 2321 } 2322 for (; i < nr_files; i++) { 2323 /* 2324 * In case of error don't forget 2325 * to put rest of file refs. 2326 */ 2327 p = flex_array_get(fa, i); 2328 fput(p->file); 2329 } 2330 if (fa) 2331 flex_array_free(fa); 2332 mmput(mm); 2333 } 2334 } 2335 2336 out_unlock: 2337 unlock_trace(task); 2338 out_put_task: 2339 put_task_struct(task); 2340 out: 2341 return ret; 2342 } 2343 2344 static const struct file_operations proc_map_files_operations = { 2345 .read = generic_read_dir, 2346 .readdir = proc_map_files_readdir, 2347 .llseek = default_llseek, 2348 }; 2349 2350 #endif /* CONFIG_CHECKPOINT_RESTORE */ 2351 2352 /* 2353 * /proc/pid/fd needs a special permission handler so that a process can still 2354 * access /proc/self/fd after it has executed a setuid(). 2355 */ 2356 static int proc_fd_permission(struct inode *inode, int mask) 2357 { 2358 int rv = generic_permission(inode, mask); 2359 if (rv == 0) 2360 return 0; 2361 if (task_pid(current) == proc_pid(inode)) 2362 rv = 0; 2363 return rv; 2364 } 2365 2366 /* 2367 * proc directories can do almost nothing.. 2368 */ 2369 static const struct inode_operations proc_fd_inode_operations = { 2370 .lookup = proc_lookupfd, 2371 .permission = proc_fd_permission, 2372 .setattr = proc_setattr, 2373 }; 2374 2375 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 2376 struct dentry *dentry, struct task_struct *task, const void *ptr) 2377 { 2378 unsigned fd = *(unsigned *)ptr; 2379 struct inode *inode; 2380 struct proc_inode *ei; 2381 struct dentry *error = ERR_PTR(-ENOENT); 2382 2383 inode = proc_pid_make_inode(dir->i_sb, task); 2384 if (!inode) 2385 goto out; 2386 ei = PROC_I(inode); 2387 ei->fd = fd; 2388 inode->i_mode = S_IFREG | S_IRUSR; 2389 inode->i_fop = &proc_fdinfo_file_operations; 2390 d_set_d_op(dentry, &tid_fd_dentry_operations); 2391 d_add(dentry, inode); 2392 /* Close the race of the process dying before we return the dentry */ 2393 if (tid_fd_revalidate(dentry, NULL)) 2394 error = NULL; 2395 2396 out: 2397 return error; 2398 } 2399 2400 static struct dentry *proc_lookupfdinfo(struct inode *dir, 2401 struct dentry *dentry, 2402 struct nameidata *nd) 2403 { 2404 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 2405 } 2406 2407 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 2408 { 2409 return proc_readfd_common(filp, dirent, filldir, 2410 proc_fdinfo_instantiate); 2411 } 2412 2413 static const struct file_operations proc_fdinfo_operations = { 2414 .read = generic_read_dir, 2415 .readdir = proc_readfdinfo, 2416 .llseek = default_llseek, 2417 }; 2418 2419 /* 2420 * proc directories can do almost nothing.. 2421 */ 2422 static const struct inode_operations proc_fdinfo_inode_operations = { 2423 .lookup = proc_lookupfdinfo, 2424 .setattr = proc_setattr, 2425 }; 2426 2427 2428 static struct dentry *proc_pident_instantiate(struct inode *dir, 2429 struct dentry *dentry, struct task_struct *task, const void *ptr) 2430 { 2431 const struct pid_entry *p = ptr; 2432 struct inode *inode; 2433 struct proc_inode *ei; 2434 struct dentry *error = ERR_PTR(-ENOENT); 2435 2436 inode = proc_pid_make_inode(dir->i_sb, task); 2437 if (!inode) 2438 goto out; 2439 2440 ei = PROC_I(inode); 2441 inode->i_mode = p->mode; 2442 if (S_ISDIR(inode->i_mode)) 2443 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2444 if (p->iop) 2445 inode->i_op = p->iop; 2446 if (p->fop) 2447 inode->i_fop = p->fop; 2448 ei->op = p->op; 2449 d_set_d_op(dentry, &pid_dentry_operations); 2450 d_add(dentry, inode); 2451 /* Close the race of the process dying before we return the dentry */ 2452 if (pid_revalidate(dentry, NULL)) 2453 error = NULL; 2454 out: 2455 return error; 2456 } 2457 2458 static struct dentry *proc_pident_lookup(struct inode *dir, 2459 struct dentry *dentry, 2460 const struct pid_entry *ents, 2461 unsigned int nents) 2462 { 2463 struct dentry *error; 2464 struct task_struct *task = get_proc_task(dir); 2465 const struct pid_entry *p, *last; 2466 2467 error = ERR_PTR(-ENOENT); 2468 2469 if (!task) 2470 goto out_no_task; 2471 2472 /* 2473 * Yes, it does not scale. And it should not. Don't add 2474 * new entries into /proc/<tgid>/ without very good reasons. 2475 */ 2476 last = &ents[nents - 1]; 2477 for (p = ents; p <= last; p++) { 2478 if (p->len != dentry->d_name.len) 2479 continue; 2480 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2481 break; 2482 } 2483 if (p > last) 2484 goto out; 2485 2486 error = proc_pident_instantiate(dir, dentry, task, p); 2487 out: 2488 put_task_struct(task); 2489 out_no_task: 2490 return error; 2491 } 2492 2493 static int proc_pident_fill_cache(struct file *filp, void *dirent, 2494 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2495 { 2496 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2497 proc_pident_instantiate, task, p); 2498 } 2499 2500 static int proc_pident_readdir(struct file *filp, 2501 void *dirent, filldir_t filldir, 2502 const struct pid_entry *ents, unsigned int nents) 2503 { 2504 int i; 2505 struct dentry *dentry = filp->f_path.dentry; 2506 struct inode *inode = dentry->d_inode; 2507 struct task_struct *task = get_proc_task(inode); 2508 const struct pid_entry *p, *last; 2509 ino_t ino; 2510 int ret; 2511 2512 ret = -ENOENT; 2513 if (!task) 2514 goto out_no_task; 2515 2516 ret = 0; 2517 i = filp->f_pos; 2518 switch (i) { 2519 case 0: 2520 ino = inode->i_ino; 2521 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 2522 goto out; 2523 i++; 2524 filp->f_pos++; 2525 /* fall through */ 2526 case 1: 2527 ino = parent_ino(dentry); 2528 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 2529 goto out; 2530 i++; 2531 filp->f_pos++; 2532 /* fall through */ 2533 default: 2534 i -= 2; 2535 if (i >= nents) { 2536 ret = 1; 2537 goto out; 2538 } 2539 p = ents + i; 2540 last = &ents[nents - 1]; 2541 while (p <= last) { 2542 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2543 goto out; 2544 filp->f_pos++; 2545 p++; 2546 } 2547 } 2548 2549 ret = 1; 2550 out: 2551 put_task_struct(task); 2552 out_no_task: 2553 return ret; 2554 } 2555 2556 #ifdef CONFIG_SECURITY 2557 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2558 size_t count, loff_t *ppos) 2559 { 2560 struct inode * inode = file->f_path.dentry->d_inode; 2561 char *p = NULL; 2562 ssize_t length; 2563 struct task_struct *task = get_proc_task(inode); 2564 2565 if (!task) 2566 return -ESRCH; 2567 2568 length = security_getprocattr(task, 2569 (char*)file->f_path.dentry->d_name.name, 2570 &p); 2571 put_task_struct(task); 2572 if (length > 0) 2573 length = simple_read_from_buffer(buf, count, ppos, p, length); 2574 kfree(p); 2575 return length; 2576 } 2577 2578 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2579 size_t count, loff_t *ppos) 2580 { 2581 struct inode * inode = file->f_path.dentry->d_inode; 2582 char *page; 2583 ssize_t length; 2584 struct task_struct *task = get_proc_task(inode); 2585 2586 length = -ESRCH; 2587 if (!task) 2588 goto out_no_task; 2589 if (count > PAGE_SIZE) 2590 count = PAGE_SIZE; 2591 2592 /* No partial writes. */ 2593 length = -EINVAL; 2594 if (*ppos != 0) 2595 goto out; 2596 2597 length = -ENOMEM; 2598 page = (char*)__get_free_page(GFP_TEMPORARY); 2599 if (!page) 2600 goto out; 2601 2602 length = -EFAULT; 2603 if (copy_from_user(page, buf, count)) 2604 goto out_free; 2605 2606 /* Guard against adverse ptrace interaction */ 2607 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex); 2608 if (length < 0) 2609 goto out_free; 2610 2611 length = security_setprocattr(task, 2612 (char*)file->f_path.dentry->d_name.name, 2613 (void*)page, count); 2614 mutex_unlock(&task->signal->cred_guard_mutex); 2615 out_free: 2616 free_page((unsigned long) page); 2617 out: 2618 put_task_struct(task); 2619 out_no_task: 2620 return length; 2621 } 2622 2623 static const struct file_operations proc_pid_attr_operations = { 2624 .read = proc_pid_attr_read, 2625 .write = proc_pid_attr_write, 2626 .llseek = generic_file_llseek, 2627 }; 2628 2629 static const struct pid_entry attr_dir_stuff[] = { 2630 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2631 REG("prev", S_IRUGO, proc_pid_attr_operations), 2632 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2633 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2634 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2635 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2636 }; 2637 2638 static int proc_attr_dir_readdir(struct file * filp, 2639 void * dirent, filldir_t filldir) 2640 { 2641 return proc_pident_readdir(filp,dirent,filldir, 2642 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2643 } 2644 2645 static const struct file_operations proc_attr_dir_operations = { 2646 .read = generic_read_dir, 2647 .readdir = proc_attr_dir_readdir, 2648 .llseek = default_llseek, 2649 }; 2650 2651 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2652 struct dentry *dentry, struct nameidata *nd) 2653 { 2654 return proc_pident_lookup(dir, dentry, 2655 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2656 } 2657 2658 static const struct inode_operations proc_attr_dir_inode_operations = { 2659 .lookup = proc_attr_dir_lookup, 2660 .getattr = pid_getattr, 2661 .setattr = proc_setattr, 2662 }; 2663 2664 #endif 2665 2666 #ifdef CONFIG_ELF_CORE 2667 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2668 size_t count, loff_t *ppos) 2669 { 2670 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2671 struct mm_struct *mm; 2672 char buffer[PROC_NUMBUF]; 2673 size_t len; 2674 int ret; 2675 2676 if (!task) 2677 return -ESRCH; 2678 2679 ret = 0; 2680 mm = get_task_mm(task); 2681 if (mm) { 2682 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2683 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2684 MMF_DUMP_FILTER_SHIFT)); 2685 mmput(mm); 2686 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2687 } 2688 2689 put_task_struct(task); 2690 2691 return ret; 2692 } 2693 2694 static ssize_t proc_coredump_filter_write(struct file *file, 2695 const char __user *buf, 2696 size_t count, 2697 loff_t *ppos) 2698 { 2699 struct task_struct *task; 2700 struct mm_struct *mm; 2701 char buffer[PROC_NUMBUF], *end; 2702 unsigned int val; 2703 int ret; 2704 int i; 2705 unsigned long mask; 2706 2707 ret = -EFAULT; 2708 memset(buffer, 0, sizeof(buffer)); 2709 if (count > sizeof(buffer) - 1) 2710 count = sizeof(buffer) - 1; 2711 if (copy_from_user(buffer, buf, count)) 2712 goto out_no_task; 2713 2714 ret = -EINVAL; 2715 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2716 if (*end == '\n') 2717 end++; 2718 if (end - buffer == 0) 2719 goto out_no_task; 2720 2721 ret = -ESRCH; 2722 task = get_proc_task(file->f_dentry->d_inode); 2723 if (!task) 2724 goto out_no_task; 2725 2726 ret = end - buffer; 2727 mm = get_task_mm(task); 2728 if (!mm) 2729 goto out_no_mm; 2730 2731 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2732 if (val & mask) 2733 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2734 else 2735 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2736 } 2737 2738 mmput(mm); 2739 out_no_mm: 2740 put_task_struct(task); 2741 out_no_task: 2742 return ret; 2743 } 2744 2745 static const struct file_operations proc_coredump_filter_operations = { 2746 .read = proc_coredump_filter_read, 2747 .write = proc_coredump_filter_write, 2748 .llseek = generic_file_llseek, 2749 }; 2750 #endif 2751 2752 /* 2753 * /proc/self: 2754 */ 2755 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2756 int buflen) 2757 { 2758 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2759 pid_t tgid = task_tgid_nr_ns(current, ns); 2760 char tmp[PROC_NUMBUF]; 2761 if (!tgid) 2762 return -ENOENT; 2763 sprintf(tmp, "%d", tgid); 2764 return vfs_readlink(dentry,buffer,buflen,tmp); 2765 } 2766 2767 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2768 { 2769 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2770 pid_t tgid = task_tgid_nr_ns(current, ns); 2771 char *name = ERR_PTR(-ENOENT); 2772 if (tgid) { 2773 name = __getname(); 2774 if (!name) 2775 name = ERR_PTR(-ENOMEM); 2776 else 2777 sprintf(name, "%d", tgid); 2778 } 2779 nd_set_link(nd, name); 2780 return NULL; 2781 } 2782 2783 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd, 2784 void *cookie) 2785 { 2786 char *s = nd_get_link(nd); 2787 if (!IS_ERR(s)) 2788 __putname(s); 2789 } 2790 2791 static const struct inode_operations proc_self_inode_operations = { 2792 .readlink = proc_self_readlink, 2793 .follow_link = proc_self_follow_link, 2794 .put_link = proc_self_put_link, 2795 }; 2796 2797 /* 2798 * proc base 2799 * 2800 * These are the directory entries in the root directory of /proc 2801 * that properly belong to the /proc filesystem, as they describe 2802 * describe something that is process related. 2803 */ 2804 static const struct pid_entry proc_base_stuff[] = { 2805 NOD("self", S_IFLNK|S_IRWXUGO, 2806 &proc_self_inode_operations, NULL, {}), 2807 }; 2808 2809 static struct dentry *proc_base_instantiate(struct inode *dir, 2810 struct dentry *dentry, struct task_struct *task, const void *ptr) 2811 { 2812 const struct pid_entry *p = ptr; 2813 struct inode *inode; 2814 struct proc_inode *ei; 2815 struct dentry *error; 2816 2817 /* Allocate the inode */ 2818 error = ERR_PTR(-ENOMEM); 2819 inode = new_inode(dir->i_sb); 2820 if (!inode) 2821 goto out; 2822 2823 /* Initialize the inode */ 2824 ei = PROC_I(inode); 2825 inode->i_ino = get_next_ino(); 2826 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2827 2828 /* 2829 * grab the reference to the task. 2830 */ 2831 ei->pid = get_task_pid(task, PIDTYPE_PID); 2832 if (!ei->pid) 2833 goto out_iput; 2834 2835 inode->i_mode = p->mode; 2836 if (S_ISDIR(inode->i_mode)) 2837 set_nlink(inode, 2); 2838 if (S_ISLNK(inode->i_mode)) 2839 inode->i_size = 64; 2840 if (p->iop) 2841 inode->i_op = p->iop; 2842 if (p->fop) 2843 inode->i_fop = p->fop; 2844 ei->op = p->op; 2845 d_add(dentry, inode); 2846 error = NULL; 2847 out: 2848 return error; 2849 out_iput: 2850 iput(inode); 2851 goto out; 2852 } 2853 2854 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2855 { 2856 struct dentry *error; 2857 struct task_struct *task = get_proc_task(dir); 2858 const struct pid_entry *p, *last; 2859 2860 error = ERR_PTR(-ENOENT); 2861 2862 if (!task) 2863 goto out_no_task; 2864 2865 /* Lookup the directory entry */ 2866 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2867 for (p = proc_base_stuff; p <= last; p++) { 2868 if (p->len != dentry->d_name.len) 2869 continue; 2870 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2871 break; 2872 } 2873 if (p > last) 2874 goto out; 2875 2876 error = proc_base_instantiate(dir, dentry, task, p); 2877 2878 out: 2879 put_task_struct(task); 2880 out_no_task: 2881 return error; 2882 } 2883 2884 static int proc_base_fill_cache(struct file *filp, void *dirent, 2885 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2886 { 2887 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2888 proc_base_instantiate, task, p); 2889 } 2890 2891 #ifdef CONFIG_TASK_IO_ACCOUNTING 2892 static int do_io_accounting(struct task_struct *task, char *buffer, int whole) 2893 { 2894 struct task_io_accounting acct = task->ioac; 2895 unsigned long flags; 2896 int result; 2897 2898 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2899 if (result) 2900 return result; 2901 2902 if (!ptrace_may_access(task, PTRACE_MODE_READ)) { 2903 result = -EACCES; 2904 goto out_unlock; 2905 } 2906 2907 if (whole && lock_task_sighand(task, &flags)) { 2908 struct task_struct *t = task; 2909 2910 task_io_accounting_add(&acct, &task->signal->ioac); 2911 while_each_thread(task, t) 2912 task_io_accounting_add(&acct, &t->ioac); 2913 2914 unlock_task_sighand(task, &flags); 2915 } 2916 result = sprintf(buffer, 2917 "rchar: %llu\n" 2918 "wchar: %llu\n" 2919 "syscr: %llu\n" 2920 "syscw: %llu\n" 2921 "read_bytes: %llu\n" 2922 "write_bytes: %llu\n" 2923 "cancelled_write_bytes: %llu\n", 2924 (unsigned long long)acct.rchar, 2925 (unsigned long long)acct.wchar, 2926 (unsigned long long)acct.syscr, 2927 (unsigned long long)acct.syscw, 2928 (unsigned long long)acct.read_bytes, 2929 (unsigned long long)acct.write_bytes, 2930 (unsigned long long)acct.cancelled_write_bytes); 2931 out_unlock: 2932 mutex_unlock(&task->signal->cred_guard_mutex); 2933 return result; 2934 } 2935 2936 static int proc_tid_io_accounting(struct task_struct *task, char *buffer) 2937 { 2938 return do_io_accounting(task, buffer, 0); 2939 } 2940 2941 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer) 2942 { 2943 return do_io_accounting(task, buffer, 1); 2944 } 2945 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2946 2947 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2948 struct pid *pid, struct task_struct *task) 2949 { 2950 int err = lock_trace(task); 2951 if (!err) { 2952 seq_printf(m, "%08x\n", task->personality); 2953 unlock_trace(task); 2954 } 2955 return err; 2956 } 2957 2958 /* 2959 * Thread groups 2960 */ 2961 static const struct file_operations proc_task_operations; 2962 static const struct inode_operations proc_task_inode_operations; 2963 2964 static const struct pid_entry tgid_base_stuff[] = { 2965 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2966 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2967 #ifdef CONFIG_CHECKPOINT_RESTORE 2968 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 2969 #endif 2970 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2971 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2972 #ifdef CONFIG_NET 2973 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2974 #endif 2975 REG("environ", S_IRUSR, proc_environ_operations), 2976 INF("auxv", S_IRUSR, proc_pid_auxv), 2977 ONE("status", S_IRUGO, proc_pid_status), 2978 ONE("personality", S_IRUGO, proc_pid_personality), 2979 INF("limits", S_IRUGO, proc_pid_limits), 2980 #ifdef CONFIG_SCHED_DEBUG 2981 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2982 #endif 2983 #ifdef CONFIG_SCHED_AUTOGROUP 2984 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2985 #endif 2986 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2987 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2988 INF("syscall", S_IRUGO, proc_pid_syscall), 2989 #endif 2990 INF("cmdline", S_IRUGO, proc_pid_cmdline), 2991 ONE("stat", S_IRUGO, proc_tgid_stat), 2992 ONE("statm", S_IRUGO, proc_pid_statm), 2993 REG("maps", S_IRUGO, proc_maps_operations), 2994 #ifdef CONFIG_NUMA 2995 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 2996 #endif 2997 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2998 LNK("cwd", proc_cwd_link), 2999 LNK("root", proc_root_link), 3000 LNK("exe", proc_exe_link), 3001 REG("mounts", S_IRUGO, proc_mounts_operations), 3002 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3003 REG("mountstats", S_IRUSR, proc_mountstats_operations), 3004 #ifdef CONFIG_PROC_PAGE_MONITOR 3005 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3006 REG("smaps", S_IRUGO, proc_smaps_operations), 3007 REG("pagemap", S_IRUGO, proc_pagemap_operations), 3008 #endif 3009 #ifdef CONFIG_SECURITY 3010 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3011 #endif 3012 #ifdef CONFIG_KALLSYMS 3013 INF("wchan", S_IRUGO, proc_pid_wchan), 3014 #endif 3015 #ifdef CONFIG_STACKTRACE 3016 ONE("stack", S_IRUGO, proc_pid_stack), 3017 #endif 3018 #ifdef CONFIG_SCHEDSTATS 3019 INF("schedstat", S_IRUGO, proc_pid_schedstat), 3020 #endif 3021 #ifdef CONFIG_LATENCYTOP 3022 REG("latency", S_IRUGO, proc_lstats_operations), 3023 #endif 3024 #ifdef CONFIG_PROC_PID_CPUSET 3025 REG("cpuset", S_IRUGO, proc_cpuset_operations), 3026 #endif 3027 #ifdef CONFIG_CGROUPS 3028 REG("cgroup", S_IRUGO, proc_cgroup_operations), 3029 #endif 3030 INF("oom_score", S_IRUGO, proc_oom_score), 3031 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 3032 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3033 #ifdef CONFIG_AUDITSYSCALL 3034 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3035 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3036 #endif 3037 #ifdef CONFIG_FAULT_INJECTION 3038 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3039 #endif 3040 #ifdef CONFIG_ELF_CORE 3041 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 3042 #endif 3043 #ifdef CONFIG_TASK_IO_ACCOUNTING 3044 INF("io", S_IRUSR, proc_tgid_io_accounting), 3045 #endif 3046 #ifdef CONFIG_HARDWALL 3047 INF("hardwall", S_IRUGO, proc_pid_hardwall), 3048 #endif 3049 }; 3050 3051 static int proc_tgid_base_readdir(struct file * filp, 3052 void * dirent, filldir_t filldir) 3053 { 3054 return proc_pident_readdir(filp,dirent,filldir, 3055 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 3056 } 3057 3058 static const struct file_operations proc_tgid_base_operations = { 3059 .read = generic_read_dir, 3060 .readdir = proc_tgid_base_readdir, 3061 .llseek = default_llseek, 3062 }; 3063 3064 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 3065 return proc_pident_lookup(dir, dentry, 3066 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3067 } 3068 3069 static const struct inode_operations proc_tgid_base_inode_operations = { 3070 .lookup = proc_tgid_base_lookup, 3071 .getattr = pid_getattr, 3072 .setattr = proc_setattr, 3073 .permission = proc_pid_permission, 3074 }; 3075 3076 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 3077 { 3078 struct dentry *dentry, *leader, *dir; 3079 char buf[PROC_NUMBUF]; 3080 struct qstr name; 3081 3082 name.name = buf; 3083 name.len = snprintf(buf, sizeof(buf), "%d", pid); 3084 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 3085 if (dentry) { 3086 shrink_dcache_parent(dentry); 3087 d_drop(dentry); 3088 dput(dentry); 3089 } 3090 3091 name.name = buf; 3092 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 3093 leader = d_hash_and_lookup(mnt->mnt_root, &name); 3094 if (!leader) 3095 goto out; 3096 3097 name.name = "task"; 3098 name.len = strlen(name.name); 3099 dir = d_hash_and_lookup(leader, &name); 3100 if (!dir) 3101 goto out_put_leader; 3102 3103 name.name = buf; 3104 name.len = snprintf(buf, sizeof(buf), "%d", pid); 3105 dentry = d_hash_and_lookup(dir, &name); 3106 if (dentry) { 3107 shrink_dcache_parent(dentry); 3108 d_drop(dentry); 3109 dput(dentry); 3110 } 3111 3112 dput(dir); 3113 out_put_leader: 3114 dput(leader); 3115 out: 3116 return; 3117 } 3118 3119 /** 3120 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 3121 * @task: task that should be flushed. 3122 * 3123 * When flushing dentries from proc, one needs to flush them from global 3124 * proc (proc_mnt) and from all the namespaces' procs this task was seen 3125 * in. This call is supposed to do all of this job. 3126 * 3127 * Looks in the dcache for 3128 * /proc/@pid 3129 * /proc/@tgid/task/@pid 3130 * if either directory is present flushes it and all of it'ts children 3131 * from the dcache. 3132 * 3133 * It is safe and reasonable to cache /proc entries for a task until 3134 * that task exits. After that they just clog up the dcache with 3135 * useless entries, possibly causing useful dcache entries to be 3136 * flushed instead. This routine is proved to flush those useless 3137 * dcache entries at process exit time. 3138 * 3139 * NOTE: This routine is just an optimization so it does not guarantee 3140 * that no dcache entries will exist at process exit time it 3141 * just makes it very unlikely that any will persist. 3142 */ 3143 3144 void proc_flush_task(struct task_struct *task) 3145 { 3146 int i; 3147 struct pid *pid, *tgid; 3148 struct upid *upid; 3149 3150 pid = task_pid(task); 3151 tgid = task_tgid(task); 3152 3153 for (i = 0; i <= pid->level; i++) { 3154 upid = &pid->numbers[i]; 3155 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3156 tgid->numbers[i].nr); 3157 } 3158 3159 upid = &pid->numbers[pid->level]; 3160 if (upid->nr == 1) 3161 pid_ns_release_proc(upid->ns); 3162 } 3163 3164 static struct dentry *proc_pid_instantiate(struct inode *dir, 3165 struct dentry * dentry, 3166 struct task_struct *task, const void *ptr) 3167 { 3168 struct dentry *error = ERR_PTR(-ENOENT); 3169 struct inode *inode; 3170 3171 inode = proc_pid_make_inode(dir->i_sb, task); 3172 if (!inode) 3173 goto out; 3174 3175 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3176 inode->i_op = &proc_tgid_base_inode_operations; 3177 inode->i_fop = &proc_tgid_base_operations; 3178 inode->i_flags|=S_IMMUTABLE; 3179 3180 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff, 3181 ARRAY_SIZE(tgid_base_stuff))); 3182 3183 d_set_d_op(dentry, &pid_dentry_operations); 3184 3185 d_add(dentry, inode); 3186 /* Close the race of the process dying before we return the dentry */ 3187 if (pid_revalidate(dentry, NULL)) 3188 error = NULL; 3189 out: 3190 return error; 3191 } 3192 3193 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 3194 { 3195 struct dentry *result; 3196 struct task_struct *task; 3197 unsigned tgid; 3198 struct pid_namespace *ns; 3199 3200 result = proc_base_lookup(dir, dentry); 3201 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 3202 goto out; 3203 3204 tgid = name_to_int(dentry); 3205 if (tgid == ~0U) 3206 goto out; 3207 3208 ns = dentry->d_sb->s_fs_info; 3209 rcu_read_lock(); 3210 task = find_task_by_pid_ns(tgid, ns); 3211 if (task) 3212 get_task_struct(task); 3213 rcu_read_unlock(); 3214 if (!task) 3215 goto out; 3216 3217 result = proc_pid_instantiate(dir, dentry, task, NULL); 3218 put_task_struct(task); 3219 out: 3220 return result; 3221 } 3222 3223 /* 3224 * Find the first task with tgid >= tgid 3225 * 3226 */ 3227 struct tgid_iter { 3228 unsigned int tgid; 3229 struct task_struct *task; 3230 }; 3231 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3232 { 3233 struct pid *pid; 3234 3235 if (iter.task) 3236 put_task_struct(iter.task); 3237 rcu_read_lock(); 3238 retry: 3239 iter.task = NULL; 3240 pid = find_ge_pid(iter.tgid, ns); 3241 if (pid) { 3242 iter.tgid = pid_nr_ns(pid, ns); 3243 iter.task = pid_task(pid, PIDTYPE_PID); 3244 /* What we to know is if the pid we have find is the 3245 * pid of a thread_group_leader. Testing for task 3246 * being a thread_group_leader is the obvious thing 3247 * todo but there is a window when it fails, due to 3248 * the pid transfer logic in de_thread. 3249 * 3250 * So we perform the straight forward test of seeing 3251 * if the pid we have found is the pid of a thread 3252 * group leader, and don't worry if the task we have 3253 * found doesn't happen to be a thread group leader. 3254 * As we don't care in the case of readdir. 3255 */ 3256 if (!iter.task || !has_group_leader_pid(iter.task)) { 3257 iter.tgid += 1; 3258 goto retry; 3259 } 3260 get_task_struct(iter.task); 3261 } 3262 rcu_read_unlock(); 3263 return iter; 3264 } 3265 3266 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 3267 3268 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3269 struct tgid_iter iter) 3270 { 3271 char name[PROC_NUMBUF]; 3272 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 3273 return proc_fill_cache(filp, dirent, filldir, name, len, 3274 proc_pid_instantiate, iter.task, NULL); 3275 } 3276 3277 static int fake_filldir(void *buf, const char *name, int namelen, 3278 loff_t offset, u64 ino, unsigned d_type) 3279 { 3280 return 0; 3281 } 3282 3283 /* for the /proc/ directory itself, after non-process stuff has been done */ 3284 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 3285 { 3286 unsigned int nr; 3287 struct task_struct *reaper; 3288 struct tgid_iter iter; 3289 struct pid_namespace *ns; 3290 filldir_t __filldir; 3291 3292 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET) 3293 goto out_no_task; 3294 nr = filp->f_pos - FIRST_PROCESS_ENTRY; 3295 3296 reaper = get_proc_task(filp->f_path.dentry->d_inode); 3297 if (!reaper) 3298 goto out_no_task; 3299 3300 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 3301 const struct pid_entry *p = &proc_base_stuff[nr]; 3302 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 3303 goto out; 3304 } 3305 3306 ns = filp->f_dentry->d_sb->s_fs_info; 3307 iter.task = NULL; 3308 iter.tgid = filp->f_pos - TGID_OFFSET; 3309 for (iter = next_tgid(ns, iter); 3310 iter.task; 3311 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3312 if (has_pid_permissions(ns, iter.task, 2)) 3313 __filldir = filldir; 3314 else 3315 __filldir = fake_filldir; 3316 3317 filp->f_pos = iter.tgid + TGID_OFFSET; 3318 if (proc_pid_fill_cache(filp, dirent, __filldir, iter) < 0) { 3319 put_task_struct(iter.task); 3320 goto out; 3321 } 3322 } 3323 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 3324 out: 3325 put_task_struct(reaper); 3326 out_no_task: 3327 return 0; 3328 } 3329 3330 /* 3331 * Tasks 3332 */ 3333 static const struct pid_entry tid_base_stuff[] = { 3334 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3335 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3336 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3337 REG("environ", S_IRUSR, proc_environ_operations), 3338 INF("auxv", S_IRUSR, proc_pid_auxv), 3339 ONE("status", S_IRUGO, proc_pid_status), 3340 ONE("personality", S_IRUGO, proc_pid_personality), 3341 INF("limits", S_IRUGO, proc_pid_limits), 3342 #ifdef CONFIG_SCHED_DEBUG 3343 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3344 #endif 3345 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3346 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3347 INF("syscall", S_IRUGO, proc_pid_syscall), 3348 #endif 3349 INF("cmdline", S_IRUGO, proc_pid_cmdline), 3350 ONE("stat", S_IRUGO, proc_tid_stat), 3351 ONE("statm", S_IRUGO, proc_pid_statm), 3352 REG("maps", S_IRUGO, proc_maps_operations), 3353 #ifdef CONFIG_NUMA 3354 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 3355 #endif 3356 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3357 LNK("cwd", proc_cwd_link), 3358 LNK("root", proc_root_link), 3359 LNK("exe", proc_exe_link), 3360 REG("mounts", S_IRUGO, proc_mounts_operations), 3361 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3362 #ifdef CONFIG_PROC_PAGE_MONITOR 3363 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3364 REG("smaps", S_IRUGO, proc_smaps_operations), 3365 REG("pagemap", S_IRUGO, proc_pagemap_operations), 3366 #endif 3367 #ifdef CONFIG_SECURITY 3368 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3369 #endif 3370 #ifdef CONFIG_KALLSYMS 3371 INF("wchan", S_IRUGO, proc_pid_wchan), 3372 #endif 3373 #ifdef CONFIG_STACKTRACE 3374 ONE("stack", S_IRUGO, proc_pid_stack), 3375 #endif 3376 #ifdef CONFIG_SCHEDSTATS 3377 INF("schedstat", S_IRUGO, proc_pid_schedstat), 3378 #endif 3379 #ifdef CONFIG_LATENCYTOP 3380 REG("latency", S_IRUGO, proc_lstats_operations), 3381 #endif 3382 #ifdef CONFIG_PROC_PID_CPUSET 3383 REG("cpuset", S_IRUGO, proc_cpuset_operations), 3384 #endif 3385 #ifdef CONFIG_CGROUPS 3386 REG("cgroup", S_IRUGO, proc_cgroup_operations), 3387 #endif 3388 INF("oom_score", S_IRUGO, proc_oom_score), 3389 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 3390 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3391 #ifdef CONFIG_AUDITSYSCALL 3392 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3393 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3394 #endif 3395 #ifdef CONFIG_FAULT_INJECTION 3396 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3397 #endif 3398 #ifdef CONFIG_TASK_IO_ACCOUNTING 3399 INF("io", S_IRUSR, proc_tid_io_accounting), 3400 #endif 3401 #ifdef CONFIG_HARDWALL 3402 INF("hardwall", S_IRUGO, proc_pid_hardwall), 3403 #endif 3404 }; 3405 3406 static int proc_tid_base_readdir(struct file * filp, 3407 void * dirent, filldir_t filldir) 3408 { 3409 return proc_pident_readdir(filp,dirent,filldir, 3410 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 3411 } 3412 3413 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 3414 return proc_pident_lookup(dir, dentry, 3415 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3416 } 3417 3418 static const struct file_operations proc_tid_base_operations = { 3419 .read = generic_read_dir, 3420 .readdir = proc_tid_base_readdir, 3421 .llseek = default_llseek, 3422 }; 3423 3424 static const struct inode_operations proc_tid_base_inode_operations = { 3425 .lookup = proc_tid_base_lookup, 3426 .getattr = pid_getattr, 3427 .setattr = proc_setattr, 3428 }; 3429 3430 static struct dentry *proc_task_instantiate(struct inode *dir, 3431 struct dentry *dentry, struct task_struct *task, const void *ptr) 3432 { 3433 struct dentry *error = ERR_PTR(-ENOENT); 3434 struct inode *inode; 3435 inode = proc_pid_make_inode(dir->i_sb, task); 3436 3437 if (!inode) 3438 goto out; 3439 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3440 inode->i_op = &proc_tid_base_inode_operations; 3441 inode->i_fop = &proc_tid_base_operations; 3442 inode->i_flags|=S_IMMUTABLE; 3443 3444 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff, 3445 ARRAY_SIZE(tid_base_stuff))); 3446 3447 d_set_d_op(dentry, &pid_dentry_operations); 3448 3449 d_add(dentry, inode); 3450 /* Close the race of the process dying before we return the dentry */ 3451 if (pid_revalidate(dentry, NULL)) 3452 error = NULL; 3453 out: 3454 return error; 3455 } 3456 3457 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 3458 { 3459 struct dentry *result = ERR_PTR(-ENOENT); 3460 struct task_struct *task; 3461 struct task_struct *leader = get_proc_task(dir); 3462 unsigned tid; 3463 struct pid_namespace *ns; 3464 3465 if (!leader) 3466 goto out_no_task; 3467 3468 tid = name_to_int(dentry); 3469 if (tid == ~0U) 3470 goto out; 3471 3472 ns = dentry->d_sb->s_fs_info; 3473 rcu_read_lock(); 3474 task = find_task_by_pid_ns(tid, ns); 3475 if (task) 3476 get_task_struct(task); 3477 rcu_read_unlock(); 3478 if (!task) 3479 goto out; 3480 if (!same_thread_group(leader, task)) 3481 goto out_drop_task; 3482 3483 result = proc_task_instantiate(dir, dentry, task, NULL); 3484 out_drop_task: 3485 put_task_struct(task); 3486 out: 3487 put_task_struct(leader); 3488 out_no_task: 3489 return result; 3490 } 3491 3492 /* 3493 * Find the first tid of a thread group to return to user space. 3494 * 3495 * Usually this is just the thread group leader, but if the users 3496 * buffer was too small or there was a seek into the middle of the 3497 * directory we have more work todo. 3498 * 3499 * In the case of a short read we start with find_task_by_pid. 3500 * 3501 * In the case of a seek we start with the leader and walk nr 3502 * threads past it. 3503 */ 3504 static struct task_struct *first_tid(struct task_struct *leader, 3505 int tid, int nr, struct pid_namespace *ns) 3506 { 3507 struct task_struct *pos; 3508 3509 rcu_read_lock(); 3510 /* Attempt to start with the pid of a thread */ 3511 if (tid && (nr > 0)) { 3512 pos = find_task_by_pid_ns(tid, ns); 3513 if (pos && (pos->group_leader == leader)) 3514 goto found; 3515 } 3516 3517 /* If nr exceeds the number of threads there is nothing todo */ 3518 pos = NULL; 3519 if (nr && nr >= get_nr_threads(leader)) 3520 goto out; 3521 3522 /* If we haven't found our starting place yet start 3523 * with the leader and walk nr threads forward. 3524 */ 3525 for (pos = leader; nr > 0; --nr) { 3526 pos = next_thread(pos); 3527 if (pos == leader) { 3528 pos = NULL; 3529 goto out; 3530 } 3531 } 3532 found: 3533 get_task_struct(pos); 3534 out: 3535 rcu_read_unlock(); 3536 return pos; 3537 } 3538 3539 /* 3540 * Find the next thread in the thread list. 3541 * Return NULL if there is an error or no next thread. 3542 * 3543 * The reference to the input task_struct is released. 3544 */ 3545 static struct task_struct *next_tid(struct task_struct *start) 3546 { 3547 struct task_struct *pos = NULL; 3548 rcu_read_lock(); 3549 if (pid_alive(start)) { 3550 pos = next_thread(start); 3551 if (thread_group_leader(pos)) 3552 pos = NULL; 3553 else 3554 get_task_struct(pos); 3555 } 3556 rcu_read_unlock(); 3557 put_task_struct(start); 3558 return pos; 3559 } 3560 3561 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3562 struct task_struct *task, int tid) 3563 { 3564 char name[PROC_NUMBUF]; 3565 int len = snprintf(name, sizeof(name), "%d", tid); 3566 return proc_fill_cache(filp, dirent, filldir, name, len, 3567 proc_task_instantiate, task, NULL); 3568 } 3569 3570 /* for the /proc/TGID/task/ directories */ 3571 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 3572 { 3573 struct dentry *dentry = filp->f_path.dentry; 3574 struct inode *inode = dentry->d_inode; 3575 struct task_struct *leader = NULL; 3576 struct task_struct *task; 3577 int retval = -ENOENT; 3578 ino_t ino; 3579 int tid; 3580 struct pid_namespace *ns; 3581 3582 task = get_proc_task(inode); 3583 if (!task) 3584 goto out_no_task; 3585 rcu_read_lock(); 3586 if (pid_alive(task)) { 3587 leader = task->group_leader; 3588 get_task_struct(leader); 3589 } 3590 rcu_read_unlock(); 3591 put_task_struct(task); 3592 if (!leader) 3593 goto out_no_task; 3594 retval = 0; 3595 3596 switch ((unsigned long)filp->f_pos) { 3597 case 0: 3598 ino = inode->i_ino; 3599 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0) 3600 goto out; 3601 filp->f_pos++; 3602 /* fall through */ 3603 case 1: 3604 ino = parent_ino(dentry); 3605 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0) 3606 goto out; 3607 filp->f_pos++; 3608 /* fall through */ 3609 } 3610 3611 /* f_version caches the tgid value that the last readdir call couldn't 3612 * return. lseek aka telldir automagically resets f_version to 0. 3613 */ 3614 ns = filp->f_dentry->d_sb->s_fs_info; 3615 tid = (int)filp->f_version; 3616 filp->f_version = 0; 3617 for (task = first_tid(leader, tid, filp->f_pos - 2, ns); 3618 task; 3619 task = next_tid(task), filp->f_pos++) { 3620 tid = task_pid_nr_ns(task, ns); 3621 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 3622 /* returning this tgid failed, save it as the first 3623 * pid for the next readir call */ 3624 filp->f_version = (u64)tid; 3625 put_task_struct(task); 3626 break; 3627 } 3628 } 3629 out: 3630 put_task_struct(leader); 3631 out_no_task: 3632 return retval; 3633 } 3634 3635 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3636 { 3637 struct inode *inode = dentry->d_inode; 3638 struct task_struct *p = get_proc_task(inode); 3639 generic_fillattr(inode, stat); 3640 3641 if (p) { 3642 stat->nlink += get_nr_threads(p); 3643 put_task_struct(p); 3644 } 3645 3646 return 0; 3647 } 3648 3649 static const struct inode_operations proc_task_inode_operations = { 3650 .lookup = proc_task_lookup, 3651 .getattr = proc_task_getattr, 3652 .setattr = proc_setattr, 3653 .permission = proc_pid_permission, 3654 }; 3655 3656 static const struct file_operations proc_task_operations = { 3657 .read = generic_read_dir, 3658 .readdir = proc_task_readdir, 3659 .llseek = default_llseek, 3660 }; 3661