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/user_namespace.h> 85 #include <linux/fs_struct.h> 86 #include <linux/slab.h> 87 #include <linux/flex_array.h> 88 #ifdef CONFIG_HARDWALL 89 #include <asm/hardwall.h> 90 #endif 91 #include <trace/events/oom.h> 92 #include "internal.h" 93 94 /* NOTE: 95 * Implementing inode permission operations in /proc is almost 96 * certainly an error. Permission checks need to happen during 97 * each system call not at open time. The reason is that most of 98 * what we wish to check for permissions in /proc varies at runtime. 99 * 100 * The classic example of a problem is opening file descriptors 101 * in /proc for a task before it execs a suid executable. 102 */ 103 104 struct pid_entry { 105 char *name; 106 int len; 107 umode_t mode; 108 const struct inode_operations *iop; 109 const struct file_operations *fop; 110 union proc_op op; 111 }; 112 113 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 114 .name = (NAME), \ 115 .len = sizeof(NAME) - 1, \ 116 .mode = MODE, \ 117 .iop = IOP, \ 118 .fop = FOP, \ 119 .op = OP, \ 120 } 121 122 #define DIR(NAME, MODE, iops, fops) \ 123 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} ) 124 #define LNK(NAME, get_link) \ 125 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 126 &proc_pid_link_inode_operations, NULL, \ 127 { .proc_get_link = get_link } ) 128 #define REG(NAME, MODE, fops) \ 129 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {}) 130 #define INF(NAME, MODE, read) \ 131 NOD(NAME, (S_IFREG|(MODE)), \ 132 NULL, &proc_info_file_operations, \ 133 { .proc_read = read } ) 134 #define ONE(NAME, MODE, show) \ 135 NOD(NAME, (S_IFREG|(MODE)), \ 136 NULL, &proc_single_file_operations, \ 137 { .proc_show = show } ) 138 139 static int proc_fd_permission(struct inode *inode, int mask); 140 141 /* 142 * Count the number of hardlinks for the pid_entry table, excluding the . 143 * and .. links. 144 */ 145 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries, 146 unsigned int n) 147 { 148 unsigned int i; 149 unsigned int count; 150 151 count = 0; 152 for (i = 0; i < n; ++i) { 153 if (S_ISDIR(entries[i].mode)) 154 ++count; 155 } 156 157 return count; 158 } 159 160 static int get_task_root(struct task_struct *task, struct path *root) 161 { 162 int result = -ENOENT; 163 164 task_lock(task); 165 if (task->fs) { 166 get_fs_root(task->fs, root); 167 result = 0; 168 } 169 task_unlock(task); 170 return result; 171 } 172 173 static int proc_cwd_link(struct dentry *dentry, struct path *path) 174 { 175 struct task_struct *task = get_proc_task(dentry->d_inode); 176 int result = -ENOENT; 177 178 if (task) { 179 task_lock(task); 180 if (task->fs) { 181 get_fs_pwd(task->fs, path); 182 result = 0; 183 } 184 task_unlock(task); 185 put_task_struct(task); 186 } 187 return result; 188 } 189 190 static int proc_root_link(struct dentry *dentry, struct path *path) 191 { 192 struct task_struct *task = get_proc_task(dentry->d_inode); 193 int result = -ENOENT; 194 195 if (task) { 196 result = get_task_root(task, path); 197 put_task_struct(task); 198 } 199 return result; 200 } 201 202 static int proc_pid_cmdline(struct task_struct *task, char * buffer) 203 { 204 int res = 0; 205 unsigned int len; 206 struct mm_struct *mm = get_task_mm(task); 207 if (!mm) 208 goto out; 209 if (!mm->arg_end) 210 goto out_mm; /* Shh! No looking before we're done */ 211 212 len = mm->arg_end - mm->arg_start; 213 214 if (len > PAGE_SIZE) 215 len = PAGE_SIZE; 216 217 res = access_process_vm(task, mm->arg_start, buffer, len, 0); 218 219 // If the nul at the end of args has been overwritten, then 220 // assume application is using setproctitle(3). 221 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) { 222 len = strnlen(buffer, res); 223 if (len < res) { 224 res = len; 225 } else { 226 len = mm->env_end - mm->env_start; 227 if (len > PAGE_SIZE - res) 228 len = PAGE_SIZE - res; 229 res += access_process_vm(task, mm->env_start, buffer+res, len, 0); 230 res = strnlen(buffer, res); 231 } 232 } 233 out_mm: 234 mmput(mm); 235 out: 236 return res; 237 } 238 239 static int proc_pid_auxv(struct task_struct *task, char *buffer) 240 { 241 struct mm_struct *mm = mm_access(task, PTRACE_MODE_READ); 242 int res = PTR_ERR(mm); 243 if (mm && !IS_ERR(mm)) { 244 unsigned int nwords = 0; 245 do { 246 nwords += 2; 247 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 248 res = nwords * sizeof(mm->saved_auxv[0]); 249 if (res > PAGE_SIZE) 250 res = PAGE_SIZE; 251 memcpy(buffer, mm->saved_auxv, res); 252 mmput(mm); 253 } 254 return res; 255 } 256 257 258 #ifdef CONFIG_KALLSYMS 259 /* 260 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 261 * Returns the resolved symbol. If that fails, simply return the address. 262 */ 263 static int proc_pid_wchan(struct task_struct *task, char *buffer) 264 { 265 unsigned long wchan; 266 char symname[KSYM_NAME_LEN]; 267 268 wchan = get_wchan(task); 269 270 if (lookup_symbol_name(wchan, symname) < 0) 271 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 272 return 0; 273 else 274 return sprintf(buffer, "%lu", wchan); 275 else 276 return sprintf(buffer, "%s", symname); 277 } 278 #endif /* CONFIG_KALLSYMS */ 279 280 static int lock_trace(struct task_struct *task) 281 { 282 int err = mutex_lock_killable(&task->signal->cred_guard_mutex); 283 if (err) 284 return err; 285 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) { 286 mutex_unlock(&task->signal->cred_guard_mutex); 287 return -EPERM; 288 } 289 return 0; 290 } 291 292 static void unlock_trace(struct task_struct *task) 293 { 294 mutex_unlock(&task->signal->cred_guard_mutex); 295 } 296 297 #ifdef CONFIG_STACKTRACE 298 299 #define MAX_STACK_TRACE_DEPTH 64 300 301 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, 302 struct pid *pid, struct task_struct *task) 303 { 304 struct stack_trace trace; 305 unsigned long *entries; 306 int err; 307 int i; 308 309 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL); 310 if (!entries) 311 return -ENOMEM; 312 313 trace.nr_entries = 0; 314 trace.max_entries = MAX_STACK_TRACE_DEPTH; 315 trace.entries = entries; 316 trace.skip = 0; 317 318 err = lock_trace(task); 319 if (!err) { 320 save_stack_trace_tsk(task, &trace); 321 322 for (i = 0; i < trace.nr_entries; i++) { 323 seq_printf(m, "[<%pK>] %pS\n", 324 (void *)entries[i], (void *)entries[i]); 325 } 326 unlock_trace(task); 327 } 328 kfree(entries); 329 330 return err; 331 } 332 #endif 333 334 #ifdef CONFIG_SCHEDSTATS 335 /* 336 * Provides /proc/PID/schedstat 337 */ 338 static int proc_pid_schedstat(struct task_struct *task, char *buffer) 339 { 340 return sprintf(buffer, "%llu %llu %lu\n", 341 (unsigned long long)task->se.sum_exec_runtime, 342 (unsigned long long)task->sched_info.run_delay, 343 task->sched_info.pcount); 344 } 345 #endif 346 347 #ifdef CONFIG_LATENCYTOP 348 static int lstats_show_proc(struct seq_file *m, void *v) 349 { 350 int i; 351 struct inode *inode = m->private; 352 struct task_struct *task = get_proc_task(inode); 353 354 if (!task) 355 return -ESRCH; 356 seq_puts(m, "Latency Top version : v0.1\n"); 357 for (i = 0; i < 32; i++) { 358 struct latency_record *lr = &task->latency_record[i]; 359 if (lr->backtrace[0]) { 360 int q; 361 seq_printf(m, "%i %li %li", 362 lr->count, lr->time, lr->max); 363 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 364 unsigned long bt = lr->backtrace[q]; 365 if (!bt) 366 break; 367 if (bt == ULONG_MAX) 368 break; 369 seq_printf(m, " %ps", (void *)bt); 370 } 371 seq_putc(m, '\n'); 372 } 373 374 } 375 put_task_struct(task); 376 return 0; 377 } 378 379 static int lstats_open(struct inode *inode, struct file *file) 380 { 381 return single_open(file, lstats_show_proc, inode); 382 } 383 384 static ssize_t lstats_write(struct file *file, const char __user *buf, 385 size_t count, loff_t *offs) 386 { 387 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 388 389 if (!task) 390 return -ESRCH; 391 clear_all_latency_tracing(task); 392 put_task_struct(task); 393 394 return count; 395 } 396 397 static const struct file_operations proc_lstats_operations = { 398 .open = lstats_open, 399 .read = seq_read, 400 .write = lstats_write, 401 .llseek = seq_lseek, 402 .release = single_release, 403 }; 404 405 #endif 406 407 static int proc_oom_score(struct task_struct *task, char *buffer) 408 { 409 unsigned long totalpages = totalram_pages + total_swap_pages; 410 unsigned long points = 0; 411 412 read_lock(&tasklist_lock); 413 if (pid_alive(task)) 414 points = oom_badness(task, NULL, NULL, totalpages) * 415 1000 / totalpages; 416 read_unlock(&tasklist_lock); 417 return sprintf(buffer, "%lu\n", points); 418 } 419 420 struct limit_names { 421 char *name; 422 char *unit; 423 }; 424 425 static const struct limit_names lnames[RLIM_NLIMITS] = { 426 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 427 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 428 [RLIMIT_DATA] = {"Max data size", "bytes"}, 429 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 430 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 431 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 432 [RLIMIT_NPROC] = {"Max processes", "processes"}, 433 [RLIMIT_NOFILE] = {"Max open files", "files"}, 434 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 435 [RLIMIT_AS] = {"Max address space", "bytes"}, 436 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 437 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 438 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 439 [RLIMIT_NICE] = {"Max nice priority", NULL}, 440 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 441 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 442 }; 443 444 /* Display limits for a process */ 445 static int proc_pid_limits(struct task_struct *task, char *buffer) 446 { 447 unsigned int i; 448 int count = 0; 449 unsigned long flags; 450 char *bufptr = buffer; 451 452 struct rlimit rlim[RLIM_NLIMITS]; 453 454 if (!lock_task_sighand(task, &flags)) 455 return 0; 456 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 457 unlock_task_sighand(task, &flags); 458 459 /* 460 * print the file header 461 */ 462 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n", 463 "Limit", "Soft Limit", "Hard Limit", "Units"); 464 465 for (i = 0; i < RLIM_NLIMITS; i++) { 466 if (rlim[i].rlim_cur == RLIM_INFINITY) 467 count += sprintf(&bufptr[count], "%-25s %-20s ", 468 lnames[i].name, "unlimited"); 469 else 470 count += sprintf(&bufptr[count], "%-25s %-20lu ", 471 lnames[i].name, rlim[i].rlim_cur); 472 473 if (rlim[i].rlim_max == RLIM_INFINITY) 474 count += sprintf(&bufptr[count], "%-20s ", "unlimited"); 475 else 476 count += sprintf(&bufptr[count], "%-20lu ", 477 rlim[i].rlim_max); 478 479 if (lnames[i].unit) 480 count += sprintf(&bufptr[count], "%-10s\n", 481 lnames[i].unit); 482 else 483 count += sprintf(&bufptr[count], "\n"); 484 } 485 486 return count; 487 } 488 489 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 490 static int proc_pid_syscall(struct task_struct *task, char *buffer) 491 { 492 long nr; 493 unsigned long args[6], sp, pc; 494 int res = lock_trace(task); 495 if (res) 496 return res; 497 498 if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) 499 res = sprintf(buffer, "running\n"); 500 else if (nr < 0) 501 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc); 502 else 503 res = sprintf(buffer, 504 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", 505 nr, 506 args[0], args[1], args[2], args[3], args[4], args[5], 507 sp, pc); 508 unlock_trace(task); 509 return res; 510 } 511 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 512 513 /************************************************************************/ 514 /* Here the fs part begins */ 515 /************************************************************************/ 516 517 /* permission checks */ 518 static int proc_fd_access_allowed(struct inode *inode) 519 { 520 struct task_struct *task; 521 int allowed = 0; 522 /* Allow access to a task's file descriptors if it is us or we 523 * may use ptrace attach to the process and find out that 524 * information. 525 */ 526 task = get_proc_task(inode); 527 if (task) { 528 allowed = ptrace_may_access(task, PTRACE_MODE_READ); 529 put_task_struct(task); 530 } 531 return allowed; 532 } 533 534 int proc_setattr(struct dentry *dentry, struct iattr *attr) 535 { 536 int error; 537 struct inode *inode = dentry->d_inode; 538 539 if (attr->ia_valid & ATTR_MODE) 540 return -EPERM; 541 542 error = inode_change_ok(inode, attr); 543 if (error) 544 return error; 545 546 if ((attr->ia_valid & ATTR_SIZE) && 547 attr->ia_size != i_size_read(inode)) { 548 error = vmtruncate(inode, attr->ia_size); 549 if (error) 550 return error; 551 } 552 553 setattr_copy(inode, attr); 554 mark_inode_dirty(inode); 555 return 0; 556 } 557 558 /* 559 * May current process learn task's sched/cmdline info (for hide_pid_min=1) 560 * or euid/egid (for hide_pid_min=2)? 561 */ 562 static bool has_pid_permissions(struct pid_namespace *pid, 563 struct task_struct *task, 564 int hide_pid_min) 565 { 566 if (pid->hide_pid < hide_pid_min) 567 return true; 568 if (in_group_p(pid->pid_gid)) 569 return true; 570 return ptrace_may_access(task, PTRACE_MODE_READ); 571 } 572 573 574 static int proc_pid_permission(struct inode *inode, int mask) 575 { 576 struct pid_namespace *pid = inode->i_sb->s_fs_info; 577 struct task_struct *task; 578 bool has_perms; 579 580 task = get_proc_task(inode); 581 if (!task) 582 return -ESRCH; 583 has_perms = has_pid_permissions(pid, task, 1); 584 put_task_struct(task); 585 586 if (!has_perms) { 587 if (pid->hide_pid == 2) { 588 /* 589 * Let's make getdents(), stat(), and open() 590 * consistent with each other. If a process 591 * may not stat() a file, it shouldn't be seen 592 * in procfs at all. 593 */ 594 return -ENOENT; 595 } 596 597 return -EPERM; 598 } 599 return generic_permission(inode, mask); 600 } 601 602 603 604 static const struct inode_operations proc_def_inode_operations = { 605 .setattr = proc_setattr, 606 }; 607 608 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */ 609 610 static ssize_t proc_info_read(struct file * file, char __user * buf, 611 size_t count, loff_t *ppos) 612 { 613 struct inode * inode = file->f_path.dentry->d_inode; 614 unsigned long page; 615 ssize_t length; 616 struct task_struct *task = get_proc_task(inode); 617 618 length = -ESRCH; 619 if (!task) 620 goto out_no_task; 621 622 if (count > PROC_BLOCK_SIZE) 623 count = PROC_BLOCK_SIZE; 624 625 length = -ENOMEM; 626 if (!(page = __get_free_page(GFP_TEMPORARY))) 627 goto out; 628 629 length = PROC_I(inode)->op.proc_read(task, (char*)page); 630 631 if (length >= 0) 632 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length); 633 free_page(page); 634 out: 635 put_task_struct(task); 636 out_no_task: 637 return length; 638 } 639 640 static const struct file_operations proc_info_file_operations = { 641 .read = proc_info_read, 642 .llseek = generic_file_llseek, 643 }; 644 645 static int proc_single_show(struct seq_file *m, void *v) 646 { 647 struct inode *inode = m->private; 648 struct pid_namespace *ns; 649 struct pid *pid; 650 struct task_struct *task; 651 int ret; 652 653 ns = inode->i_sb->s_fs_info; 654 pid = proc_pid(inode); 655 task = get_pid_task(pid, PIDTYPE_PID); 656 if (!task) 657 return -ESRCH; 658 659 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 660 661 put_task_struct(task); 662 return ret; 663 } 664 665 static int proc_single_open(struct inode *inode, struct file *filp) 666 { 667 return single_open(filp, proc_single_show, inode); 668 } 669 670 static const struct file_operations proc_single_file_operations = { 671 .open = proc_single_open, 672 .read = seq_read, 673 .llseek = seq_lseek, 674 .release = single_release, 675 }; 676 677 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) 678 { 679 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 680 struct mm_struct *mm; 681 682 if (!task) 683 return -ESRCH; 684 685 mm = mm_access(task, mode); 686 put_task_struct(task); 687 688 if (IS_ERR(mm)) 689 return PTR_ERR(mm); 690 691 if (mm) { 692 /* ensure this mm_struct can't be freed */ 693 atomic_inc(&mm->mm_count); 694 /* but do not pin its memory */ 695 mmput(mm); 696 } 697 698 file->private_data = mm; 699 700 return 0; 701 } 702 703 static int mem_open(struct inode *inode, struct file *file) 704 { 705 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH); 706 707 /* OK to pass negative loff_t, we can catch out-of-range */ 708 file->f_mode |= FMODE_UNSIGNED_OFFSET; 709 710 return ret; 711 } 712 713 static ssize_t mem_rw(struct file *file, char __user *buf, 714 size_t count, loff_t *ppos, int write) 715 { 716 struct mm_struct *mm = file->private_data; 717 unsigned long addr = *ppos; 718 ssize_t copied; 719 char *page; 720 721 if (!mm) 722 return 0; 723 724 page = (char *)__get_free_page(GFP_TEMPORARY); 725 if (!page) 726 return -ENOMEM; 727 728 copied = 0; 729 if (!atomic_inc_not_zero(&mm->mm_users)) 730 goto free; 731 732 while (count > 0) { 733 int this_len = min_t(int, count, PAGE_SIZE); 734 735 if (write && copy_from_user(page, buf, this_len)) { 736 copied = -EFAULT; 737 break; 738 } 739 740 this_len = access_remote_vm(mm, addr, page, this_len, write); 741 if (!this_len) { 742 if (!copied) 743 copied = -EIO; 744 break; 745 } 746 747 if (!write && copy_to_user(buf, page, this_len)) { 748 copied = -EFAULT; 749 break; 750 } 751 752 buf += this_len; 753 addr += this_len; 754 copied += this_len; 755 count -= this_len; 756 } 757 *ppos = addr; 758 759 mmput(mm); 760 free: 761 free_page((unsigned long) page); 762 return copied; 763 } 764 765 static ssize_t mem_read(struct file *file, char __user *buf, 766 size_t count, loff_t *ppos) 767 { 768 return mem_rw(file, buf, count, ppos, 0); 769 } 770 771 static ssize_t mem_write(struct file *file, const char __user *buf, 772 size_t count, loff_t *ppos) 773 { 774 return mem_rw(file, (char __user*)buf, count, ppos, 1); 775 } 776 777 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 778 { 779 switch (orig) { 780 case 0: 781 file->f_pos = offset; 782 break; 783 case 1: 784 file->f_pos += offset; 785 break; 786 default: 787 return -EINVAL; 788 } 789 force_successful_syscall_return(); 790 return file->f_pos; 791 } 792 793 static int mem_release(struct inode *inode, struct file *file) 794 { 795 struct mm_struct *mm = file->private_data; 796 if (mm) 797 mmdrop(mm); 798 return 0; 799 } 800 801 static const struct file_operations proc_mem_operations = { 802 .llseek = mem_lseek, 803 .read = mem_read, 804 .write = mem_write, 805 .open = mem_open, 806 .release = mem_release, 807 }; 808 809 static int environ_open(struct inode *inode, struct file *file) 810 { 811 return __mem_open(inode, file, PTRACE_MODE_READ); 812 } 813 814 static ssize_t environ_read(struct file *file, char __user *buf, 815 size_t count, loff_t *ppos) 816 { 817 char *page; 818 unsigned long src = *ppos; 819 int ret = 0; 820 struct mm_struct *mm = file->private_data; 821 822 if (!mm) 823 return 0; 824 825 page = (char *)__get_free_page(GFP_TEMPORARY); 826 if (!page) 827 return -ENOMEM; 828 829 ret = 0; 830 if (!atomic_inc_not_zero(&mm->mm_users)) 831 goto free; 832 while (count > 0) { 833 size_t this_len, max_len; 834 int retval; 835 836 if (src >= (mm->env_end - mm->env_start)) 837 break; 838 839 this_len = mm->env_end - (mm->env_start + src); 840 841 max_len = min_t(size_t, PAGE_SIZE, count); 842 this_len = min(max_len, this_len); 843 844 retval = access_remote_vm(mm, (mm->env_start + src), 845 page, this_len, 0); 846 847 if (retval <= 0) { 848 ret = retval; 849 break; 850 } 851 852 if (copy_to_user(buf, page, retval)) { 853 ret = -EFAULT; 854 break; 855 } 856 857 ret += retval; 858 src += retval; 859 buf += retval; 860 count -= retval; 861 } 862 *ppos = src; 863 mmput(mm); 864 865 free: 866 free_page((unsigned long) page); 867 return ret; 868 } 869 870 static const struct file_operations proc_environ_operations = { 871 .open = environ_open, 872 .read = environ_read, 873 .llseek = generic_file_llseek, 874 .release = mem_release, 875 }; 876 877 static ssize_t oom_adjust_read(struct file *file, char __user *buf, 878 size_t count, loff_t *ppos) 879 { 880 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 881 char buffer[PROC_NUMBUF]; 882 size_t len; 883 int oom_adjust = OOM_DISABLE; 884 unsigned long flags; 885 886 if (!task) 887 return -ESRCH; 888 889 if (lock_task_sighand(task, &flags)) { 890 oom_adjust = task->signal->oom_adj; 891 unlock_task_sighand(task, &flags); 892 } 893 894 put_task_struct(task); 895 896 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); 897 898 return simple_read_from_buffer(buf, count, ppos, buffer, len); 899 } 900 901 static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 902 size_t count, loff_t *ppos) 903 { 904 struct task_struct *task; 905 char buffer[PROC_NUMBUF]; 906 int oom_adjust; 907 unsigned long flags; 908 int err; 909 910 memset(buffer, 0, sizeof(buffer)); 911 if (count > sizeof(buffer) - 1) 912 count = sizeof(buffer) - 1; 913 if (copy_from_user(buffer, buf, count)) { 914 err = -EFAULT; 915 goto out; 916 } 917 918 err = kstrtoint(strstrip(buffer), 0, &oom_adjust); 919 if (err) 920 goto out; 921 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && 922 oom_adjust != OOM_DISABLE) { 923 err = -EINVAL; 924 goto out; 925 } 926 927 task = get_proc_task(file->f_path.dentry->d_inode); 928 if (!task) { 929 err = -ESRCH; 930 goto out; 931 } 932 933 task_lock(task); 934 if (!task->mm) { 935 err = -EINVAL; 936 goto err_task_lock; 937 } 938 939 if (!lock_task_sighand(task, &flags)) { 940 err = -ESRCH; 941 goto err_task_lock; 942 } 943 944 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) { 945 err = -EACCES; 946 goto err_sighand; 947 } 948 949 /* 950 * Warn that /proc/pid/oom_adj is deprecated, see 951 * Documentation/feature-removal-schedule.txt. 952 */ 953 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 954 current->comm, task_pid_nr(current), task_pid_nr(task), 955 task_pid_nr(task)); 956 task->signal->oom_adj = oom_adjust; 957 /* 958 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 959 * value is always attainable. 960 */ 961 if (task->signal->oom_adj == OOM_ADJUST_MAX) 962 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX; 963 else 964 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) / 965 -OOM_DISABLE; 966 trace_oom_score_adj_update(task); 967 err_sighand: 968 unlock_task_sighand(task, &flags); 969 err_task_lock: 970 task_unlock(task); 971 put_task_struct(task); 972 out: 973 return err < 0 ? err : count; 974 } 975 976 static const struct file_operations proc_oom_adjust_operations = { 977 .read = oom_adjust_read, 978 .write = oom_adjust_write, 979 .llseek = generic_file_llseek, 980 }; 981 982 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 983 size_t count, loff_t *ppos) 984 { 985 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 986 char buffer[PROC_NUMBUF]; 987 int oom_score_adj = OOM_SCORE_ADJ_MIN; 988 unsigned long flags; 989 size_t len; 990 991 if (!task) 992 return -ESRCH; 993 if (lock_task_sighand(task, &flags)) { 994 oom_score_adj = task->signal->oom_score_adj; 995 unlock_task_sighand(task, &flags); 996 } 997 put_task_struct(task); 998 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj); 999 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1000 } 1001 1002 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1003 size_t count, loff_t *ppos) 1004 { 1005 struct task_struct *task; 1006 char buffer[PROC_NUMBUF]; 1007 unsigned long flags; 1008 int oom_score_adj; 1009 int err; 1010 1011 memset(buffer, 0, sizeof(buffer)); 1012 if (count > sizeof(buffer) - 1) 1013 count = sizeof(buffer) - 1; 1014 if (copy_from_user(buffer, buf, count)) { 1015 err = -EFAULT; 1016 goto out; 1017 } 1018 1019 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 1020 if (err) 1021 goto out; 1022 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1023 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1024 err = -EINVAL; 1025 goto out; 1026 } 1027 1028 task = get_proc_task(file->f_path.dentry->d_inode); 1029 if (!task) { 1030 err = -ESRCH; 1031 goto out; 1032 } 1033 1034 task_lock(task); 1035 if (!task->mm) { 1036 err = -EINVAL; 1037 goto err_task_lock; 1038 } 1039 1040 if (!lock_task_sighand(task, &flags)) { 1041 err = -ESRCH; 1042 goto err_task_lock; 1043 } 1044 1045 if (oom_score_adj < task->signal->oom_score_adj_min && 1046 !capable(CAP_SYS_RESOURCE)) { 1047 err = -EACCES; 1048 goto err_sighand; 1049 } 1050 1051 task->signal->oom_score_adj = oom_score_adj; 1052 if (has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1053 task->signal->oom_score_adj_min = oom_score_adj; 1054 trace_oom_score_adj_update(task); 1055 /* 1056 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is 1057 * always attainable. 1058 */ 1059 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) 1060 task->signal->oom_adj = OOM_DISABLE; 1061 else 1062 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) / 1063 OOM_SCORE_ADJ_MAX; 1064 err_sighand: 1065 unlock_task_sighand(task, &flags); 1066 err_task_lock: 1067 task_unlock(task); 1068 put_task_struct(task); 1069 out: 1070 return err < 0 ? err : count; 1071 } 1072 1073 static const struct file_operations proc_oom_score_adj_operations = { 1074 .read = oom_score_adj_read, 1075 .write = oom_score_adj_write, 1076 .llseek = default_llseek, 1077 }; 1078 1079 #ifdef CONFIG_AUDITSYSCALL 1080 #define TMPBUFLEN 21 1081 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1082 size_t count, loff_t *ppos) 1083 { 1084 struct inode * inode = file->f_path.dentry->d_inode; 1085 struct task_struct *task = get_proc_task(inode); 1086 ssize_t length; 1087 char tmpbuf[TMPBUFLEN]; 1088 1089 if (!task) 1090 return -ESRCH; 1091 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1092 audit_get_loginuid(task)); 1093 put_task_struct(task); 1094 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1095 } 1096 1097 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1098 size_t count, loff_t *ppos) 1099 { 1100 struct inode * inode = file->f_path.dentry->d_inode; 1101 char *page, *tmp; 1102 ssize_t length; 1103 uid_t loginuid; 1104 1105 rcu_read_lock(); 1106 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1107 rcu_read_unlock(); 1108 return -EPERM; 1109 } 1110 rcu_read_unlock(); 1111 1112 if (count >= PAGE_SIZE) 1113 count = PAGE_SIZE - 1; 1114 1115 if (*ppos != 0) { 1116 /* No partial writes. */ 1117 return -EINVAL; 1118 } 1119 page = (char*)__get_free_page(GFP_TEMPORARY); 1120 if (!page) 1121 return -ENOMEM; 1122 length = -EFAULT; 1123 if (copy_from_user(page, buf, count)) 1124 goto out_free_page; 1125 1126 page[count] = '\0'; 1127 loginuid = simple_strtoul(page, &tmp, 10); 1128 if (tmp == page) { 1129 length = -EINVAL; 1130 goto out_free_page; 1131 1132 } 1133 length = audit_set_loginuid(loginuid); 1134 if (likely(length == 0)) 1135 length = count; 1136 1137 out_free_page: 1138 free_page((unsigned long) page); 1139 return length; 1140 } 1141 1142 static const struct file_operations proc_loginuid_operations = { 1143 .read = proc_loginuid_read, 1144 .write = proc_loginuid_write, 1145 .llseek = generic_file_llseek, 1146 }; 1147 1148 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1149 size_t count, loff_t *ppos) 1150 { 1151 struct inode * inode = file->f_path.dentry->d_inode; 1152 struct task_struct *task = get_proc_task(inode); 1153 ssize_t length; 1154 char tmpbuf[TMPBUFLEN]; 1155 1156 if (!task) 1157 return -ESRCH; 1158 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1159 audit_get_sessionid(task)); 1160 put_task_struct(task); 1161 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1162 } 1163 1164 static const struct file_operations proc_sessionid_operations = { 1165 .read = proc_sessionid_read, 1166 .llseek = generic_file_llseek, 1167 }; 1168 #endif 1169 1170 #ifdef CONFIG_FAULT_INJECTION 1171 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1172 size_t count, loff_t *ppos) 1173 { 1174 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1175 char buffer[PROC_NUMBUF]; 1176 size_t len; 1177 int make_it_fail; 1178 1179 if (!task) 1180 return -ESRCH; 1181 make_it_fail = task->make_it_fail; 1182 put_task_struct(task); 1183 1184 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1185 1186 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1187 } 1188 1189 static ssize_t proc_fault_inject_write(struct file * file, 1190 const char __user * buf, size_t count, loff_t *ppos) 1191 { 1192 struct task_struct *task; 1193 char buffer[PROC_NUMBUF], *end; 1194 int make_it_fail; 1195 1196 if (!capable(CAP_SYS_RESOURCE)) 1197 return -EPERM; 1198 memset(buffer, 0, sizeof(buffer)); 1199 if (count > sizeof(buffer) - 1) 1200 count = sizeof(buffer) - 1; 1201 if (copy_from_user(buffer, buf, count)) 1202 return -EFAULT; 1203 make_it_fail = simple_strtol(strstrip(buffer), &end, 0); 1204 if (*end) 1205 return -EINVAL; 1206 task = get_proc_task(file->f_dentry->d_inode); 1207 if (!task) 1208 return -ESRCH; 1209 task->make_it_fail = make_it_fail; 1210 put_task_struct(task); 1211 1212 return count; 1213 } 1214 1215 static const struct file_operations proc_fault_inject_operations = { 1216 .read = proc_fault_inject_read, 1217 .write = proc_fault_inject_write, 1218 .llseek = generic_file_llseek, 1219 }; 1220 #endif 1221 1222 1223 #ifdef CONFIG_SCHED_DEBUG 1224 /* 1225 * Print out various scheduling related per-task fields: 1226 */ 1227 static int sched_show(struct seq_file *m, void *v) 1228 { 1229 struct inode *inode = m->private; 1230 struct task_struct *p; 1231 1232 p = get_proc_task(inode); 1233 if (!p) 1234 return -ESRCH; 1235 proc_sched_show_task(p, m); 1236 1237 put_task_struct(p); 1238 1239 return 0; 1240 } 1241 1242 static ssize_t 1243 sched_write(struct file *file, const char __user *buf, 1244 size_t count, loff_t *offset) 1245 { 1246 struct inode *inode = file->f_path.dentry->d_inode; 1247 struct task_struct *p; 1248 1249 p = get_proc_task(inode); 1250 if (!p) 1251 return -ESRCH; 1252 proc_sched_set_task(p); 1253 1254 put_task_struct(p); 1255 1256 return count; 1257 } 1258 1259 static int sched_open(struct inode *inode, struct file *filp) 1260 { 1261 return single_open(filp, sched_show, inode); 1262 } 1263 1264 static const struct file_operations proc_pid_sched_operations = { 1265 .open = sched_open, 1266 .read = seq_read, 1267 .write = sched_write, 1268 .llseek = seq_lseek, 1269 .release = single_release, 1270 }; 1271 1272 #endif 1273 1274 #ifdef CONFIG_SCHED_AUTOGROUP 1275 /* 1276 * Print out autogroup related information: 1277 */ 1278 static int sched_autogroup_show(struct seq_file *m, void *v) 1279 { 1280 struct inode *inode = m->private; 1281 struct task_struct *p; 1282 1283 p = get_proc_task(inode); 1284 if (!p) 1285 return -ESRCH; 1286 proc_sched_autogroup_show_task(p, m); 1287 1288 put_task_struct(p); 1289 1290 return 0; 1291 } 1292 1293 static ssize_t 1294 sched_autogroup_write(struct file *file, const char __user *buf, 1295 size_t count, loff_t *offset) 1296 { 1297 struct inode *inode = file->f_path.dentry->d_inode; 1298 struct task_struct *p; 1299 char buffer[PROC_NUMBUF]; 1300 int nice; 1301 int err; 1302 1303 memset(buffer, 0, sizeof(buffer)); 1304 if (count > sizeof(buffer) - 1) 1305 count = sizeof(buffer) - 1; 1306 if (copy_from_user(buffer, buf, count)) 1307 return -EFAULT; 1308 1309 err = kstrtoint(strstrip(buffer), 0, &nice); 1310 if (err < 0) 1311 return err; 1312 1313 p = get_proc_task(inode); 1314 if (!p) 1315 return -ESRCH; 1316 1317 err = proc_sched_autogroup_set_nice(p, nice); 1318 if (err) 1319 count = err; 1320 1321 put_task_struct(p); 1322 1323 return count; 1324 } 1325 1326 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1327 { 1328 int ret; 1329 1330 ret = single_open(filp, sched_autogroup_show, NULL); 1331 if (!ret) { 1332 struct seq_file *m = filp->private_data; 1333 1334 m->private = inode; 1335 } 1336 return ret; 1337 } 1338 1339 static const struct file_operations proc_pid_sched_autogroup_operations = { 1340 .open = sched_autogroup_open, 1341 .read = seq_read, 1342 .write = sched_autogroup_write, 1343 .llseek = seq_lseek, 1344 .release = single_release, 1345 }; 1346 1347 #endif /* CONFIG_SCHED_AUTOGROUP */ 1348 1349 static ssize_t comm_write(struct file *file, const char __user *buf, 1350 size_t count, loff_t *offset) 1351 { 1352 struct inode *inode = file->f_path.dentry->d_inode; 1353 struct task_struct *p; 1354 char buffer[TASK_COMM_LEN]; 1355 1356 memset(buffer, 0, sizeof(buffer)); 1357 if (count > sizeof(buffer) - 1) 1358 count = sizeof(buffer) - 1; 1359 if (copy_from_user(buffer, buf, count)) 1360 return -EFAULT; 1361 1362 p = get_proc_task(inode); 1363 if (!p) 1364 return -ESRCH; 1365 1366 if (same_thread_group(current, p)) 1367 set_task_comm(p, buffer); 1368 else 1369 count = -EINVAL; 1370 1371 put_task_struct(p); 1372 1373 return count; 1374 } 1375 1376 static int comm_show(struct seq_file *m, void *v) 1377 { 1378 struct inode *inode = m->private; 1379 struct task_struct *p; 1380 1381 p = get_proc_task(inode); 1382 if (!p) 1383 return -ESRCH; 1384 1385 task_lock(p); 1386 seq_printf(m, "%s\n", p->comm); 1387 task_unlock(p); 1388 1389 put_task_struct(p); 1390 1391 return 0; 1392 } 1393 1394 static int comm_open(struct inode *inode, struct file *filp) 1395 { 1396 return single_open(filp, comm_show, inode); 1397 } 1398 1399 static const struct file_operations proc_pid_set_comm_operations = { 1400 .open = comm_open, 1401 .read = seq_read, 1402 .write = comm_write, 1403 .llseek = seq_lseek, 1404 .release = single_release, 1405 }; 1406 1407 static int proc_exe_link(struct dentry *dentry, struct path *exe_path) 1408 { 1409 struct task_struct *task; 1410 struct mm_struct *mm; 1411 struct file *exe_file; 1412 1413 task = get_proc_task(dentry->d_inode); 1414 if (!task) 1415 return -ENOENT; 1416 mm = get_task_mm(task); 1417 put_task_struct(task); 1418 if (!mm) 1419 return -ENOENT; 1420 exe_file = get_mm_exe_file(mm); 1421 mmput(mm); 1422 if (exe_file) { 1423 *exe_path = exe_file->f_path; 1424 path_get(&exe_file->f_path); 1425 fput(exe_file); 1426 return 0; 1427 } else 1428 return -ENOENT; 1429 } 1430 1431 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1432 { 1433 struct inode *inode = dentry->d_inode; 1434 struct path path; 1435 int error = -EACCES; 1436 1437 /* Are we allowed to snoop on the tasks file descriptors? */ 1438 if (!proc_fd_access_allowed(inode)) 1439 goto out; 1440 1441 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1442 if (error) 1443 goto out; 1444 1445 nd_jump_link(nd, &path); 1446 return NULL; 1447 out: 1448 return ERR_PTR(error); 1449 } 1450 1451 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1452 { 1453 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1454 char *pathname; 1455 int len; 1456 1457 if (!tmp) 1458 return -ENOMEM; 1459 1460 pathname = d_path(path, tmp, PAGE_SIZE); 1461 len = PTR_ERR(pathname); 1462 if (IS_ERR(pathname)) 1463 goto out; 1464 len = tmp + PAGE_SIZE - 1 - pathname; 1465 1466 if (len > buflen) 1467 len = buflen; 1468 if (copy_to_user(buffer, pathname, len)) 1469 len = -EFAULT; 1470 out: 1471 free_page((unsigned long)tmp); 1472 return len; 1473 } 1474 1475 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1476 { 1477 int error = -EACCES; 1478 struct inode *inode = dentry->d_inode; 1479 struct path path; 1480 1481 /* Are we allowed to snoop on the tasks file descriptors? */ 1482 if (!proc_fd_access_allowed(inode)) 1483 goto out; 1484 1485 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1486 if (error) 1487 goto out; 1488 1489 error = do_proc_readlink(&path, buffer, buflen); 1490 path_put(&path); 1491 out: 1492 return error; 1493 } 1494 1495 static const struct inode_operations proc_pid_link_inode_operations = { 1496 .readlink = proc_pid_readlink, 1497 .follow_link = proc_pid_follow_link, 1498 .setattr = proc_setattr, 1499 }; 1500 1501 1502 /* building an inode */ 1503 1504 static int task_dumpable(struct task_struct *task) 1505 { 1506 int dumpable = 0; 1507 struct mm_struct *mm; 1508 1509 task_lock(task); 1510 mm = task->mm; 1511 if (mm) 1512 dumpable = get_dumpable(mm); 1513 task_unlock(task); 1514 if(dumpable == 1) 1515 return 1; 1516 return 0; 1517 } 1518 1519 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1520 { 1521 struct inode * inode; 1522 struct proc_inode *ei; 1523 const struct cred *cred; 1524 1525 /* We need a new inode */ 1526 1527 inode = new_inode(sb); 1528 if (!inode) 1529 goto out; 1530 1531 /* Common stuff */ 1532 ei = PROC_I(inode); 1533 inode->i_ino = get_next_ino(); 1534 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1535 inode->i_op = &proc_def_inode_operations; 1536 1537 /* 1538 * grab the reference to task. 1539 */ 1540 ei->pid = get_task_pid(task, PIDTYPE_PID); 1541 if (!ei->pid) 1542 goto out_unlock; 1543 1544 if (task_dumpable(task)) { 1545 rcu_read_lock(); 1546 cred = __task_cred(task); 1547 inode->i_uid = cred->euid; 1548 inode->i_gid = cred->egid; 1549 rcu_read_unlock(); 1550 } 1551 security_task_to_inode(task, inode); 1552 1553 out: 1554 return inode; 1555 1556 out_unlock: 1557 iput(inode); 1558 return NULL; 1559 } 1560 1561 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1562 { 1563 struct inode *inode = dentry->d_inode; 1564 struct task_struct *task; 1565 const struct cred *cred; 1566 struct pid_namespace *pid = dentry->d_sb->s_fs_info; 1567 1568 generic_fillattr(inode, stat); 1569 1570 rcu_read_lock(); 1571 stat->uid = GLOBAL_ROOT_UID; 1572 stat->gid = GLOBAL_ROOT_GID; 1573 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1574 if (task) { 1575 if (!has_pid_permissions(pid, task, 2)) { 1576 rcu_read_unlock(); 1577 /* 1578 * This doesn't prevent learning whether PID exists, 1579 * it only makes getattr() consistent with readdir(). 1580 */ 1581 return -ENOENT; 1582 } 1583 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1584 task_dumpable(task)) { 1585 cred = __task_cred(task); 1586 stat->uid = cred->euid; 1587 stat->gid = cred->egid; 1588 } 1589 } 1590 rcu_read_unlock(); 1591 return 0; 1592 } 1593 1594 /* dentry stuff */ 1595 1596 /* 1597 * Exceptional case: normally we are not allowed to unhash a busy 1598 * directory. In this case, however, we can do it - no aliasing problems 1599 * due to the way we treat inodes. 1600 * 1601 * Rewrite the inode's ownerships here because the owning task may have 1602 * performed a setuid(), etc. 1603 * 1604 * Before the /proc/pid/status file was created the only way to read 1605 * the effective uid of a /process was to stat /proc/pid. Reading 1606 * /proc/pid/status is slow enough that procps and other packages 1607 * kept stating /proc/pid. To keep the rules in /proc simple I have 1608 * made this apply to all per process world readable and executable 1609 * directories. 1610 */ 1611 int pid_revalidate(struct dentry *dentry, unsigned int flags) 1612 { 1613 struct inode *inode; 1614 struct task_struct *task; 1615 const struct cred *cred; 1616 1617 if (flags & LOOKUP_RCU) 1618 return -ECHILD; 1619 1620 inode = dentry->d_inode; 1621 task = get_proc_task(inode); 1622 1623 if (task) { 1624 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1625 task_dumpable(task)) { 1626 rcu_read_lock(); 1627 cred = __task_cred(task); 1628 inode->i_uid = cred->euid; 1629 inode->i_gid = cred->egid; 1630 rcu_read_unlock(); 1631 } else { 1632 inode->i_uid = GLOBAL_ROOT_UID; 1633 inode->i_gid = GLOBAL_ROOT_GID; 1634 } 1635 inode->i_mode &= ~(S_ISUID | S_ISGID); 1636 security_task_to_inode(task, inode); 1637 put_task_struct(task); 1638 return 1; 1639 } 1640 d_drop(dentry); 1641 return 0; 1642 } 1643 1644 static int pid_delete_dentry(const struct dentry * dentry) 1645 { 1646 /* Is the task we represent dead? 1647 * If so, then don't put the dentry on the lru list, 1648 * kill it immediately. 1649 */ 1650 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1651 } 1652 1653 const struct dentry_operations pid_dentry_operations = 1654 { 1655 .d_revalidate = pid_revalidate, 1656 .d_delete = pid_delete_dentry, 1657 }; 1658 1659 /* Lookups */ 1660 1661 /* 1662 * Fill a directory entry. 1663 * 1664 * If possible create the dcache entry and derive our inode number and 1665 * file type from dcache entry. 1666 * 1667 * Since all of the proc inode numbers are dynamically generated, the inode 1668 * numbers do not exist until the inode is cache. This means creating the 1669 * the dcache entry in readdir is necessary to keep the inode numbers 1670 * reported by readdir in sync with the inode numbers reported 1671 * by stat. 1672 */ 1673 int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1674 const char *name, int len, 1675 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1676 { 1677 struct dentry *child, *dir = filp->f_path.dentry; 1678 struct inode *inode; 1679 struct qstr qname; 1680 ino_t ino = 0; 1681 unsigned type = DT_UNKNOWN; 1682 1683 qname.name = name; 1684 qname.len = len; 1685 qname.hash = full_name_hash(name, len); 1686 1687 child = d_lookup(dir, &qname); 1688 if (!child) { 1689 struct dentry *new; 1690 new = d_alloc(dir, &qname); 1691 if (new) { 1692 child = instantiate(dir->d_inode, new, task, ptr); 1693 if (child) 1694 dput(new); 1695 else 1696 child = new; 1697 } 1698 } 1699 if (!child || IS_ERR(child) || !child->d_inode) 1700 goto end_instantiate; 1701 inode = child->d_inode; 1702 if (inode) { 1703 ino = inode->i_ino; 1704 type = inode->i_mode >> 12; 1705 } 1706 dput(child); 1707 end_instantiate: 1708 if (!ino) 1709 ino = find_inode_number(dir, &qname); 1710 if (!ino) 1711 ino = 1; 1712 return filldir(dirent, name, len, filp->f_pos, ino, type); 1713 } 1714 1715 static unsigned name_to_int(struct dentry *dentry) 1716 { 1717 const char *name = dentry->d_name.name; 1718 int len = dentry->d_name.len; 1719 unsigned n = 0; 1720 1721 if (len > 1 && *name == '0') 1722 goto out; 1723 while (len-- > 0) { 1724 unsigned c = *name++ - '0'; 1725 if (c > 9) 1726 goto out; 1727 if (n >= (~0U-9)/10) 1728 goto out; 1729 n *= 10; 1730 n += c; 1731 } 1732 return n; 1733 out: 1734 return ~0U; 1735 } 1736 1737 #define PROC_FDINFO_MAX 64 1738 1739 static int proc_fd_info(struct inode *inode, struct path *path, char *info) 1740 { 1741 struct task_struct *task = get_proc_task(inode); 1742 struct files_struct *files = NULL; 1743 struct file *file; 1744 int fd = proc_fd(inode); 1745 1746 if (task) { 1747 files = get_files_struct(task); 1748 put_task_struct(task); 1749 } 1750 if (files) { 1751 /* 1752 * We are not taking a ref to the file structure, so we must 1753 * hold ->file_lock. 1754 */ 1755 spin_lock(&files->file_lock); 1756 file = fcheck_files(files, fd); 1757 if (file) { 1758 unsigned int f_flags; 1759 struct fdtable *fdt; 1760 1761 fdt = files_fdtable(files); 1762 f_flags = file->f_flags & ~O_CLOEXEC; 1763 if (close_on_exec(fd, fdt)) 1764 f_flags |= O_CLOEXEC; 1765 1766 if (path) { 1767 *path = file->f_path; 1768 path_get(&file->f_path); 1769 } 1770 if (info) 1771 snprintf(info, PROC_FDINFO_MAX, 1772 "pos:\t%lli\n" 1773 "flags:\t0%o\n", 1774 (long long) file->f_pos, 1775 f_flags); 1776 spin_unlock(&files->file_lock); 1777 put_files_struct(files); 1778 return 0; 1779 } 1780 spin_unlock(&files->file_lock); 1781 put_files_struct(files); 1782 } 1783 return -ENOENT; 1784 } 1785 1786 static int proc_fd_link(struct dentry *dentry, struct path *path) 1787 { 1788 return proc_fd_info(dentry->d_inode, path, NULL); 1789 } 1790 1791 static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags) 1792 { 1793 struct inode *inode; 1794 struct task_struct *task; 1795 int fd; 1796 struct files_struct *files; 1797 const struct cred *cred; 1798 1799 if (flags & LOOKUP_RCU) 1800 return -ECHILD; 1801 1802 inode = dentry->d_inode; 1803 task = get_proc_task(inode); 1804 fd = proc_fd(inode); 1805 1806 if (task) { 1807 files = get_files_struct(task); 1808 if (files) { 1809 struct file *file; 1810 rcu_read_lock(); 1811 file = fcheck_files(files, fd); 1812 if (file) { 1813 unsigned f_mode = file->f_mode; 1814 1815 rcu_read_unlock(); 1816 put_files_struct(files); 1817 1818 if (task_dumpable(task)) { 1819 rcu_read_lock(); 1820 cred = __task_cred(task); 1821 inode->i_uid = cred->euid; 1822 inode->i_gid = cred->egid; 1823 rcu_read_unlock(); 1824 } else { 1825 inode->i_uid = GLOBAL_ROOT_UID; 1826 inode->i_gid = GLOBAL_ROOT_GID; 1827 } 1828 1829 if (S_ISLNK(inode->i_mode)) { 1830 unsigned i_mode = S_IFLNK; 1831 if (f_mode & FMODE_READ) 1832 i_mode |= S_IRUSR | S_IXUSR; 1833 if (f_mode & FMODE_WRITE) 1834 i_mode |= S_IWUSR | S_IXUSR; 1835 inode->i_mode = i_mode; 1836 } 1837 1838 security_task_to_inode(task, inode); 1839 put_task_struct(task); 1840 return 1; 1841 } 1842 rcu_read_unlock(); 1843 put_files_struct(files); 1844 } 1845 put_task_struct(task); 1846 } 1847 d_drop(dentry); 1848 return 0; 1849 } 1850 1851 static const struct dentry_operations tid_fd_dentry_operations = 1852 { 1853 .d_revalidate = tid_fd_revalidate, 1854 .d_delete = pid_delete_dentry, 1855 }; 1856 1857 static struct dentry *proc_fd_instantiate(struct inode *dir, 1858 struct dentry *dentry, struct task_struct *task, const void *ptr) 1859 { 1860 unsigned fd = (unsigned long)ptr; 1861 struct inode *inode; 1862 struct proc_inode *ei; 1863 struct dentry *error = ERR_PTR(-ENOENT); 1864 1865 inode = proc_pid_make_inode(dir->i_sb, task); 1866 if (!inode) 1867 goto out; 1868 ei = PROC_I(inode); 1869 ei->fd = fd; 1870 1871 inode->i_mode = S_IFLNK; 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, 0)) 1879 error = NULL; 1880 1881 out: 1882 return error; 1883 } 1884 1885 static struct dentry *proc_lookupfd_common(struct inode *dir, 1886 struct dentry *dentry, 1887 instantiate_t instantiate) 1888 { 1889 struct task_struct *task = get_proc_task(dir); 1890 unsigned fd = name_to_int(dentry); 1891 struct dentry *result = ERR_PTR(-ENOENT); 1892 1893 if (!task) 1894 goto out_no_task; 1895 if (fd == ~0U) 1896 goto out; 1897 1898 result = instantiate(dir, dentry, task, (void *)(unsigned long)fd); 1899 out: 1900 put_task_struct(task); 1901 out_no_task: 1902 return result; 1903 } 1904 1905 static int proc_readfd_common(struct file * filp, void * dirent, 1906 filldir_t filldir, instantiate_t instantiate) 1907 { 1908 struct dentry *dentry = filp->f_path.dentry; 1909 struct inode *inode = dentry->d_inode; 1910 struct task_struct *p = get_proc_task(inode); 1911 unsigned int fd, ino; 1912 int retval; 1913 struct files_struct * files; 1914 1915 retval = -ENOENT; 1916 if (!p) 1917 goto out_no_task; 1918 retval = 0; 1919 1920 fd = filp->f_pos; 1921 switch (fd) { 1922 case 0: 1923 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 1924 goto out; 1925 filp->f_pos++; 1926 case 1: 1927 ino = parent_ino(dentry); 1928 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 1929 goto out; 1930 filp->f_pos++; 1931 default: 1932 files = get_files_struct(p); 1933 if (!files) 1934 goto out; 1935 rcu_read_lock(); 1936 for (fd = filp->f_pos-2; 1937 fd < files_fdtable(files)->max_fds; 1938 fd++, filp->f_pos++) { 1939 char name[PROC_NUMBUF]; 1940 int len; 1941 int rv; 1942 1943 if (!fcheck_files(files, fd)) 1944 continue; 1945 rcu_read_unlock(); 1946 1947 len = snprintf(name, sizeof(name), "%d", fd); 1948 rv = proc_fill_cache(filp, dirent, filldir, 1949 name, len, instantiate, p, 1950 (void *)(unsigned long)fd); 1951 if (rv < 0) 1952 goto out_fd_loop; 1953 rcu_read_lock(); 1954 } 1955 rcu_read_unlock(); 1956 out_fd_loop: 1957 put_files_struct(files); 1958 } 1959 out: 1960 put_task_struct(p); 1961 out_no_task: 1962 return retval; 1963 } 1964 1965 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 1966 unsigned int flags) 1967 { 1968 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 1969 } 1970 1971 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 1972 { 1973 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 1974 } 1975 1976 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 1977 size_t len, loff_t *ppos) 1978 { 1979 char tmp[PROC_FDINFO_MAX]; 1980 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); 1981 if (!err) 1982 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 1983 return err; 1984 } 1985 1986 static const struct file_operations proc_fdinfo_file_operations = { 1987 .open = nonseekable_open, 1988 .read = proc_fdinfo_read, 1989 .llseek = no_llseek, 1990 }; 1991 1992 static const struct file_operations proc_fd_operations = { 1993 .read = generic_read_dir, 1994 .readdir = proc_readfd, 1995 .llseek = default_llseek, 1996 }; 1997 1998 #ifdef CONFIG_CHECKPOINT_RESTORE 1999 2000 /* 2001 * dname_to_vma_addr - maps a dentry name into two unsigned longs 2002 * which represent vma start and end addresses. 2003 */ 2004 static int dname_to_vma_addr(struct dentry *dentry, 2005 unsigned long *start, unsigned long *end) 2006 { 2007 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2) 2008 return -EINVAL; 2009 2010 return 0; 2011 } 2012 2013 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags) 2014 { 2015 unsigned long vm_start, vm_end; 2016 bool exact_vma_exists = false; 2017 struct mm_struct *mm = NULL; 2018 struct task_struct *task; 2019 const struct cred *cred; 2020 struct inode *inode; 2021 int status = 0; 2022 2023 if (flags & LOOKUP_RCU) 2024 return -ECHILD; 2025 2026 if (!capable(CAP_SYS_ADMIN)) { 2027 status = -EACCES; 2028 goto out_notask; 2029 } 2030 2031 inode = dentry->d_inode; 2032 task = get_proc_task(inode); 2033 if (!task) 2034 goto out_notask; 2035 2036 mm = mm_access(task, PTRACE_MODE_READ); 2037 if (IS_ERR_OR_NULL(mm)) 2038 goto out; 2039 2040 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 2041 down_read(&mm->mmap_sem); 2042 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end); 2043 up_read(&mm->mmap_sem); 2044 } 2045 2046 mmput(mm); 2047 2048 if (exact_vma_exists) { 2049 if (task_dumpable(task)) { 2050 rcu_read_lock(); 2051 cred = __task_cred(task); 2052 inode->i_uid = cred->euid; 2053 inode->i_gid = cred->egid; 2054 rcu_read_unlock(); 2055 } else { 2056 inode->i_uid = GLOBAL_ROOT_UID; 2057 inode->i_gid = GLOBAL_ROOT_GID; 2058 } 2059 security_task_to_inode(task, inode); 2060 status = 1; 2061 } 2062 2063 out: 2064 put_task_struct(task); 2065 2066 out_notask: 2067 if (status <= 0) 2068 d_drop(dentry); 2069 2070 return status; 2071 } 2072 2073 static const struct dentry_operations tid_map_files_dentry_operations = { 2074 .d_revalidate = map_files_d_revalidate, 2075 .d_delete = pid_delete_dentry, 2076 }; 2077 2078 static int proc_map_files_get_link(struct dentry *dentry, struct path *path) 2079 { 2080 unsigned long vm_start, vm_end; 2081 struct vm_area_struct *vma; 2082 struct task_struct *task; 2083 struct mm_struct *mm; 2084 int rc; 2085 2086 rc = -ENOENT; 2087 task = get_proc_task(dentry->d_inode); 2088 if (!task) 2089 goto out; 2090 2091 mm = get_task_mm(task); 2092 put_task_struct(task); 2093 if (!mm) 2094 goto out; 2095 2096 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 2097 if (rc) 2098 goto out_mmput; 2099 2100 down_read(&mm->mmap_sem); 2101 vma = find_exact_vma(mm, vm_start, vm_end); 2102 if (vma && vma->vm_file) { 2103 *path = vma->vm_file->f_path; 2104 path_get(path); 2105 rc = 0; 2106 } 2107 up_read(&mm->mmap_sem); 2108 2109 out_mmput: 2110 mmput(mm); 2111 out: 2112 return rc; 2113 } 2114 2115 struct map_files_info { 2116 struct file *file; 2117 unsigned long len; 2118 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */ 2119 }; 2120 2121 static struct dentry * 2122 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry, 2123 struct task_struct *task, const void *ptr) 2124 { 2125 const struct file *file = ptr; 2126 struct proc_inode *ei; 2127 struct inode *inode; 2128 2129 if (!file) 2130 return ERR_PTR(-ENOENT); 2131 2132 inode = proc_pid_make_inode(dir->i_sb, task); 2133 if (!inode) 2134 return ERR_PTR(-ENOENT); 2135 2136 ei = PROC_I(inode); 2137 ei->op.proc_get_link = proc_map_files_get_link; 2138 2139 inode->i_op = &proc_pid_link_inode_operations; 2140 inode->i_size = 64; 2141 inode->i_mode = S_IFLNK; 2142 2143 if (file->f_mode & FMODE_READ) 2144 inode->i_mode |= S_IRUSR; 2145 if (file->f_mode & FMODE_WRITE) 2146 inode->i_mode |= S_IWUSR; 2147 2148 d_set_d_op(dentry, &tid_map_files_dentry_operations); 2149 d_add(dentry, inode); 2150 2151 return NULL; 2152 } 2153 2154 static struct dentry *proc_map_files_lookup(struct inode *dir, 2155 struct dentry *dentry, unsigned int flags) 2156 { 2157 unsigned long vm_start, vm_end; 2158 struct vm_area_struct *vma; 2159 struct task_struct *task; 2160 struct dentry *result; 2161 struct mm_struct *mm; 2162 2163 result = ERR_PTR(-EACCES); 2164 if (!capable(CAP_SYS_ADMIN)) 2165 goto out; 2166 2167 result = ERR_PTR(-ENOENT); 2168 task = get_proc_task(dir); 2169 if (!task) 2170 goto out; 2171 2172 result = ERR_PTR(-EACCES); 2173 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 2174 goto out_put_task; 2175 2176 result = ERR_PTR(-ENOENT); 2177 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 2178 goto out_put_task; 2179 2180 mm = get_task_mm(task); 2181 if (!mm) 2182 goto out_put_task; 2183 2184 down_read(&mm->mmap_sem); 2185 vma = find_exact_vma(mm, vm_start, vm_end); 2186 if (!vma) 2187 goto out_no_vma; 2188 2189 result = proc_map_files_instantiate(dir, dentry, task, vma->vm_file); 2190 2191 out_no_vma: 2192 up_read(&mm->mmap_sem); 2193 mmput(mm); 2194 out_put_task: 2195 put_task_struct(task); 2196 out: 2197 return result; 2198 } 2199 2200 static const struct inode_operations proc_map_files_inode_operations = { 2201 .lookup = proc_map_files_lookup, 2202 .permission = proc_fd_permission, 2203 .setattr = proc_setattr, 2204 }; 2205 2206 static int 2207 proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir) 2208 { 2209 struct dentry *dentry = filp->f_path.dentry; 2210 struct inode *inode = dentry->d_inode; 2211 struct vm_area_struct *vma; 2212 struct task_struct *task; 2213 struct mm_struct *mm; 2214 ino_t ino; 2215 int ret; 2216 2217 ret = -EACCES; 2218 if (!capable(CAP_SYS_ADMIN)) 2219 goto out; 2220 2221 ret = -ENOENT; 2222 task = get_proc_task(inode); 2223 if (!task) 2224 goto out; 2225 2226 ret = -EACCES; 2227 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 2228 goto out_put_task; 2229 2230 ret = 0; 2231 switch (filp->f_pos) { 2232 case 0: 2233 ino = inode->i_ino; 2234 if (filldir(dirent, ".", 1, 0, ino, DT_DIR) < 0) 2235 goto out_put_task; 2236 filp->f_pos++; 2237 case 1: 2238 ino = parent_ino(dentry); 2239 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 2240 goto out_put_task; 2241 filp->f_pos++; 2242 default: 2243 { 2244 unsigned long nr_files, pos, i; 2245 struct flex_array *fa = NULL; 2246 struct map_files_info info; 2247 struct map_files_info *p; 2248 2249 mm = get_task_mm(task); 2250 if (!mm) 2251 goto out_put_task; 2252 down_read(&mm->mmap_sem); 2253 2254 nr_files = 0; 2255 2256 /* 2257 * We need two passes here: 2258 * 2259 * 1) Collect vmas of mapped files with mmap_sem taken 2260 * 2) Release mmap_sem and instantiate entries 2261 * 2262 * otherwise we get lockdep complained, since filldir() 2263 * routine might require mmap_sem taken in might_fault(). 2264 */ 2265 2266 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 2267 if (vma->vm_file && ++pos > filp->f_pos) 2268 nr_files++; 2269 } 2270 2271 if (nr_files) { 2272 fa = flex_array_alloc(sizeof(info), nr_files, 2273 GFP_KERNEL); 2274 if (!fa || flex_array_prealloc(fa, 0, nr_files, 2275 GFP_KERNEL)) { 2276 ret = -ENOMEM; 2277 if (fa) 2278 flex_array_free(fa); 2279 up_read(&mm->mmap_sem); 2280 mmput(mm); 2281 goto out_put_task; 2282 } 2283 for (i = 0, vma = mm->mmap, pos = 2; vma; 2284 vma = vma->vm_next) { 2285 if (!vma->vm_file) 2286 continue; 2287 if (++pos <= filp->f_pos) 2288 continue; 2289 2290 get_file(vma->vm_file); 2291 info.file = vma->vm_file; 2292 info.len = snprintf(info.name, 2293 sizeof(info.name), "%lx-%lx", 2294 vma->vm_start, vma->vm_end); 2295 if (flex_array_put(fa, i++, &info, GFP_KERNEL)) 2296 BUG(); 2297 } 2298 } 2299 up_read(&mm->mmap_sem); 2300 2301 for (i = 0; i < nr_files; i++) { 2302 p = flex_array_get(fa, i); 2303 ret = proc_fill_cache(filp, dirent, filldir, 2304 p->name, p->len, 2305 proc_map_files_instantiate, 2306 task, p->file); 2307 if (ret) 2308 break; 2309 filp->f_pos++; 2310 fput(p->file); 2311 } 2312 for (; i < nr_files; i++) { 2313 /* 2314 * In case of error don't forget 2315 * to put rest of file refs. 2316 */ 2317 p = flex_array_get(fa, i); 2318 fput(p->file); 2319 } 2320 if (fa) 2321 flex_array_free(fa); 2322 mmput(mm); 2323 } 2324 } 2325 2326 out_put_task: 2327 put_task_struct(task); 2328 out: 2329 return ret; 2330 } 2331 2332 static const struct file_operations proc_map_files_operations = { 2333 .read = generic_read_dir, 2334 .readdir = proc_map_files_readdir, 2335 .llseek = default_llseek, 2336 }; 2337 2338 #endif /* CONFIG_CHECKPOINT_RESTORE */ 2339 2340 /* 2341 * /proc/pid/fd needs a special permission handler so that a process can still 2342 * access /proc/self/fd after it has executed a setuid(). 2343 */ 2344 static int proc_fd_permission(struct inode *inode, int mask) 2345 { 2346 int rv = generic_permission(inode, mask); 2347 if (rv == 0) 2348 return 0; 2349 if (task_pid(current) == proc_pid(inode)) 2350 rv = 0; 2351 return rv; 2352 } 2353 2354 /* 2355 * proc directories can do almost nothing.. 2356 */ 2357 static const struct inode_operations proc_fd_inode_operations = { 2358 .lookup = proc_lookupfd, 2359 .permission = proc_fd_permission, 2360 .setattr = proc_setattr, 2361 }; 2362 2363 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 2364 struct dentry *dentry, struct task_struct *task, const void *ptr) 2365 { 2366 unsigned fd = (unsigned long)ptr; 2367 struct inode *inode; 2368 struct proc_inode *ei; 2369 struct dentry *error = ERR_PTR(-ENOENT); 2370 2371 inode = proc_pid_make_inode(dir->i_sb, task); 2372 if (!inode) 2373 goto out; 2374 ei = PROC_I(inode); 2375 ei->fd = fd; 2376 inode->i_mode = S_IFREG | S_IRUSR; 2377 inode->i_fop = &proc_fdinfo_file_operations; 2378 d_set_d_op(dentry, &tid_fd_dentry_operations); 2379 d_add(dentry, inode); 2380 /* Close the race of the process dying before we return the dentry */ 2381 if (tid_fd_revalidate(dentry, 0)) 2382 error = NULL; 2383 2384 out: 2385 return error; 2386 } 2387 2388 static struct dentry *proc_lookupfdinfo(struct inode *dir, 2389 struct dentry *dentry, 2390 unsigned int flags) 2391 { 2392 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 2393 } 2394 2395 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 2396 { 2397 return proc_readfd_common(filp, dirent, filldir, 2398 proc_fdinfo_instantiate); 2399 } 2400 2401 static const struct file_operations proc_fdinfo_operations = { 2402 .read = generic_read_dir, 2403 .readdir = proc_readfdinfo, 2404 .llseek = default_llseek, 2405 }; 2406 2407 /* 2408 * proc directories can do almost nothing.. 2409 */ 2410 static const struct inode_operations proc_fdinfo_inode_operations = { 2411 .lookup = proc_lookupfdinfo, 2412 .setattr = proc_setattr, 2413 }; 2414 2415 2416 static struct dentry *proc_pident_instantiate(struct inode *dir, 2417 struct dentry *dentry, struct task_struct *task, const void *ptr) 2418 { 2419 const struct pid_entry *p = ptr; 2420 struct inode *inode; 2421 struct proc_inode *ei; 2422 struct dentry *error = ERR_PTR(-ENOENT); 2423 2424 inode = proc_pid_make_inode(dir->i_sb, task); 2425 if (!inode) 2426 goto out; 2427 2428 ei = PROC_I(inode); 2429 inode->i_mode = p->mode; 2430 if (S_ISDIR(inode->i_mode)) 2431 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2432 if (p->iop) 2433 inode->i_op = p->iop; 2434 if (p->fop) 2435 inode->i_fop = p->fop; 2436 ei->op = p->op; 2437 d_set_d_op(dentry, &pid_dentry_operations); 2438 d_add(dentry, inode); 2439 /* Close the race of the process dying before we return the dentry */ 2440 if (pid_revalidate(dentry, 0)) 2441 error = NULL; 2442 out: 2443 return error; 2444 } 2445 2446 static struct dentry *proc_pident_lookup(struct inode *dir, 2447 struct dentry *dentry, 2448 const struct pid_entry *ents, 2449 unsigned int nents) 2450 { 2451 struct dentry *error; 2452 struct task_struct *task = get_proc_task(dir); 2453 const struct pid_entry *p, *last; 2454 2455 error = ERR_PTR(-ENOENT); 2456 2457 if (!task) 2458 goto out_no_task; 2459 2460 /* 2461 * Yes, it does not scale. And it should not. Don't add 2462 * new entries into /proc/<tgid>/ without very good reasons. 2463 */ 2464 last = &ents[nents - 1]; 2465 for (p = ents; p <= last; p++) { 2466 if (p->len != dentry->d_name.len) 2467 continue; 2468 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2469 break; 2470 } 2471 if (p > last) 2472 goto out; 2473 2474 error = proc_pident_instantiate(dir, dentry, task, p); 2475 out: 2476 put_task_struct(task); 2477 out_no_task: 2478 return error; 2479 } 2480 2481 static int proc_pident_fill_cache(struct file *filp, void *dirent, 2482 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2483 { 2484 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2485 proc_pident_instantiate, task, p); 2486 } 2487 2488 static int proc_pident_readdir(struct file *filp, 2489 void *dirent, filldir_t filldir, 2490 const struct pid_entry *ents, unsigned int nents) 2491 { 2492 int i; 2493 struct dentry *dentry = filp->f_path.dentry; 2494 struct inode *inode = dentry->d_inode; 2495 struct task_struct *task = get_proc_task(inode); 2496 const struct pid_entry *p, *last; 2497 ino_t ino; 2498 int ret; 2499 2500 ret = -ENOENT; 2501 if (!task) 2502 goto out_no_task; 2503 2504 ret = 0; 2505 i = filp->f_pos; 2506 switch (i) { 2507 case 0: 2508 ino = inode->i_ino; 2509 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 2510 goto out; 2511 i++; 2512 filp->f_pos++; 2513 /* fall through */ 2514 case 1: 2515 ino = parent_ino(dentry); 2516 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 2517 goto out; 2518 i++; 2519 filp->f_pos++; 2520 /* fall through */ 2521 default: 2522 i -= 2; 2523 if (i >= nents) { 2524 ret = 1; 2525 goto out; 2526 } 2527 p = ents + i; 2528 last = &ents[nents - 1]; 2529 while (p <= last) { 2530 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2531 goto out; 2532 filp->f_pos++; 2533 p++; 2534 } 2535 } 2536 2537 ret = 1; 2538 out: 2539 put_task_struct(task); 2540 out_no_task: 2541 return ret; 2542 } 2543 2544 #ifdef CONFIG_SECURITY 2545 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2546 size_t count, loff_t *ppos) 2547 { 2548 struct inode * inode = file->f_path.dentry->d_inode; 2549 char *p = NULL; 2550 ssize_t length; 2551 struct task_struct *task = get_proc_task(inode); 2552 2553 if (!task) 2554 return -ESRCH; 2555 2556 length = security_getprocattr(task, 2557 (char*)file->f_path.dentry->d_name.name, 2558 &p); 2559 put_task_struct(task); 2560 if (length > 0) 2561 length = simple_read_from_buffer(buf, count, ppos, p, length); 2562 kfree(p); 2563 return length; 2564 } 2565 2566 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2567 size_t count, loff_t *ppos) 2568 { 2569 struct inode * inode = file->f_path.dentry->d_inode; 2570 char *page; 2571 ssize_t length; 2572 struct task_struct *task = get_proc_task(inode); 2573 2574 length = -ESRCH; 2575 if (!task) 2576 goto out_no_task; 2577 if (count > PAGE_SIZE) 2578 count = PAGE_SIZE; 2579 2580 /* No partial writes. */ 2581 length = -EINVAL; 2582 if (*ppos != 0) 2583 goto out; 2584 2585 length = -ENOMEM; 2586 page = (char*)__get_free_page(GFP_TEMPORARY); 2587 if (!page) 2588 goto out; 2589 2590 length = -EFAULT; 2591 if (copy_from_user(page, buf, count)) 2592 goto out_free; 2593 2594 /* Guard against adverse ptrace interaction */ 2595 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex); 2596 if (length < 0) 2597 goto out_free; 2598 2599 length = security_setprocattr(task, 2600 (char*)file->f_path.dentry->d_name.name, 2601 (void*)page, count); 2602 mutex_unlock(&task->signal->cred_guard_mutex); 2603 out_free: 2604 free_page((unsigned long) page); 2605 out: 2606 put_task_struct(task); 2607 out_no_task: 2608 return length; 2609 } 2610 2611 static const struct file_operations proc_pid_attr_operations = { 2612 .read = proc_pid_attr_read, 2613 .write = proc_pid_attr_write, 2614 .llseek = generic_file_llseek, 2615 }; 2616 2617 static const struct pid_entry attr_dir_stuff[] = { 2618 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2619 REG("prev", S_IRUGO, proc_pid_attr_operations), 2620 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2621 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2622 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2623 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2624 }; 2625 2626 static int proc_attr_dir_readdir(struct file * filp, 2627 void * dirent, filldir_t filldir) 2628 { 2629 return proc_pident_readdir(filp,dirent,filldir, 2630 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2631 } 2632 2633 static const struct file_operations proc_attr_dir_operations = { 2634 .read = generic_read_dir, 2635 .readdir = proc_attr_dir_readdir, 2636 .llseek = default_llseek, 2637 }; 2638 2639 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2640 struct dentry *dentry, unsigned int flags) 2641 { 2642 return proc_pident_lookup(dir, dentry, 2643 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2644 } 2645 2646 static const struct inode_operations proc_attr_dir_inode_operations = { 2647 .lookup = proc_attr_dir_lookup, 2648 .getattr = pid_getattr, 2649 .setattr = proc_setattr, 2650 }; 2651 2652 #endif 2653 2654 #ifdef CONFIG_ELF_CORE 2655 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2656 size_t count, loff_t *ppos) 2657 { 2658 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2659 struct mm_struct *mm; 2660 char buffer[PROC_NUMBUF]; 2661 size_t len; 2662 int ret; 2663 2664 if (!task) 2665 return -ESRCH; 2666 2667 ret = 0; 2668 mm = get_task_mm(task); 2669 if (mm) { 2670 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2671 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2672 MMF_DUMP_FILTER_SHIFT)); 2673 mmput(mm); 2674 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2675 } 2676 2677 put_task_struct(task); 2678 2679 return ret; 2680 } 2681 2682 static ssize_t proc_coredump_filter_write(struct file *file, 2683 const char __user *buf, 2684 size_t count, 2685 loff_t *ppos) 2686 { 2687 struct task_struct *task; 2688 struct mm_struct *mm; 2689 char buffer[PROC_NUMBUF], *end; 2690 unsigned int val; 2691 int ret; 2692 int i; 2693 unsigned long mask; 2694 2695 ret = -EFAULT; 2696 memset(buffer, 0, sizeof(buffer)); 2697 if (count > sizeof(buffer) - 1) 2698 count = sizeof(buffer) - 1; 2699 if (copy_from_user(buffer, buf, count)) 2700 goto out_no_task; 2701 2702 ret = -EINVAL; 2703 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2704 if (*end == '\n') 2705 end++; 2706 if (end - buffer == 0) 2707 goto out_no_task; 2708 2709 ret = -ESRCH; 2710 task = get_proc_task(file->f_dentry->d_inode); 2711 if (!task) 2712 goto out_no_task; 2713 2714 ret = end - buffer; 2715 mm = get_task_mm(task); 2716 if (!mm) 2717 goto out_no_mm; 2718 2719 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2720 if (val & mask) 2721 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2722 else 2723 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2724 } 2725 2726 mmput(mm); 2727 out_no_mm: 2728 put_task_struct(task); 2729 out_no_task: 2730 return ret; 2731 } 2732 2733 static const struct file_operations proc_coredump_filter_operations = { 2734 .read = proc_coredump_filter_read, 2735 .write = proc_coredump_filter_write, 2736 .llseek = generic_file_llseek, 2737 }; 2738 #endif 2739 2740 /* 2741 * /proc/self: 2742 */ 2743 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2744 int buflen) 2745 { 2746 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2747 pid_t tgid = task_tgid_nr_ns(current, ns); 2748 char tmp[PROC_NUMBUF]; 2749 if (!tgid) 2750 return -ENOENT; 2751 sprintf(tmp, "%d", tgid); 2752 return vfs_readlink(dentry,buffer,buflen,tmp); 2753 } 2754 2755 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2756 { 2757 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2758 pid_t tgid = task_tgid_nr_ns(current, ns); 2759 char *name = ERR_PTR(-ENOENT); 2760 if (tgid) { 2761 name = __getname(); 2762 if (!name) 2763 name = ERR_PTR(-ENOMEM); 2764 else 2765 sprintf(name, "%d", tgid); 2766 } 2767 nd_set_link(nd, name); 2768 return NULL; 2769 } 2770 2771 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd, 2772 void *cookie) 2773 { 2774 char *s = nd_get_link(nd); 2775 if (!IS_ERR(s)) 2776 __putname(s); 2777 } 2778 2779 static const struct inode_operations proc_self_inode_operations = { 2780 .readlink = proc_self_readlink, 2781 .follow_link = proc_self_follow_link, 2782 .put_link = proc_self_put_link, 2783 }; 2784 2785 /* 2786 * proc base 2787 * 2788 * These are the directory entries in the root directory of /proc 2789 * that properly belong to the /proc filesystem, as they describe 2790 * describe something that is process related. 2791 */ 2792 static const struct pid_entry proc_base_stuff[] = { 2793 NOD("self", S_IFLNK|S_IRWXUGO, 2794 &proc_self_inode_operations, NULL, {}), 2795 }; 2796 2797 static struct dentry *proc_base_instantiate(struct inode *dir, 2798 struct dentry *dentry, struct task_struct *task, const void *ptr) 2799 { 2800 const struct pid_entry *p = ptr; 2801 struct inode *inode; 2802 struct proc_inode *ei; 2803 struct dentry *error; 2804 2805 /* Allocate the inode */ 2806 error = ERR_PTR(-ENOMEM); 2807 inode = new_inode(dir->i_sb); 2808 if (!inode) 2809 goto out; 2810 2811 /* Initialize the inode */ 2812 ei = PROC_I(inode); 2813 inode->i_ino = get_next_ino(); 2814 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2815 2816 /* 2817 * grab the reference to the task. 2818 */ 2819 ei->pid = get_task_pid(task, PIDTYPE_PID); 2820 if (!ei->pid) 2821 goto out_iput; 2822 2823 inode->i_mode = p->mode; 2824 if (S_ISDIR(inode->i_mode)) 2825 set_nlink(inode, 2); 2826 if (S_ISLNK(inode->i_mode)) 2827 inode->i_size = 64; 2828 if (p->iop) 2829 inode->i_op = p->iop; 2830 if (p->fop) 2831 inode->i_fop = p->fop; 2832 ei->op = p->op; 2833 d_add(dentry, inode); 2834 error = NULL; 2835 out: 2836 return error; 2837 out_iput: 2838 iput(inode); 2839 goto out; 2840 } 2841 2842 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2843 { 2844 struct dentry *error; 2845 struct task_struct *task = get_proc_task(dir); 2846 const struct pid_entry *p, *last; 2847 2848 error = ERR_PTR(-ENOENT); 2849 2850 if (!task) 2851 goto out_no_task; 2852 2853 /* Lookup the directory entry */ 2854 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2855 for (p = proc_base_stuff; p <= last; p++) { 2856 if (p->len != dentry->d_name.len) 2857 continue; 2858 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2859 break; 2860 } 2861 if (p > last) 2862 goto out; 2863 2864 error = proc_base_instantiate(dir, dentry, task, p); 2865 2866 out: 2867 put_task_struct(task); 2868 out_no_task: 2869 return error; 2870 } 2871 2872 static int proc_base_fill_cache(struct file *filp, void *dirent, 2873 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2874 { 2875 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2876 proc_base_instantiate, task, p); 2877 } 2878 2879 #ifdef CONFIG_TASK_IO_ACCOUNTING 2880 static int do_io_accounting(struct task_struct *task, char *buffer, int whole) 2881 { 2882 struct task_io_accounting acct = task->ioac; 2883 unsigned long flags; 2884 int result; 2885 2886 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2887 if (result) 2888 return result; 2889 2890 if (!ptrace_may_access(task, PTRACE_MODE_READ)) { 2891 result = -EACCES; 2892 goto out_unlock; 2893 } 2894 2895 if (whole && lock_task_sighand(task, &flags)) { 2896 struct task_struct *t = task; 2897 2898 task_io_accounting_add(&acct, &task->signal->ioac); 2899 while_each_thread(task, t) 2900 task_io_accounting_add(&acct, &t->ioac); 2901 2902 unlock_task_sighand(task, &flags); 2903 } 2904 result = sprintf(buffer, 2905 "rchar: %llu\n" 2906 "wchar: %llu\n" 2907 "syscr: %llu\n" 2908 "syscw: %llu\n" 2909 "read_bytes: %llu\n" 2910 "write_bytes: %llu\n" 2911 "cancelled_write_bytes: %llu\n", 2912 (unsigned long long)acct.rchar, 2913 (unsigned long long)acct.wchar, 2914 (unsigned long long)acct.syscr, 2915 (unsigned long long)acct.syscw, 2916 (unsigned long long)acct.read_bytes, 2917 (unsigned long long)acct.write_bytes, 2918 (unsigned long long)acct.cancelled_write_bytes); 2919 out_unlock: 2920 mutex_unlock(&task->signal->cred_guard_mutex); 2921 return result; 2922 } 2923 2924 static int proc_tid_io_accounting(struct task_struct *task, char *buffer) 2925 { 2926 return do_io_accounting(task, buffer, 0); 2927 } 2928 2929 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer) 2930 { 2931 return do_io_accounting(task, buffer, 1); 2932 } 2933 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2934 2935 #ifdef CONFIG_USER_NS 2936 static int proc_id_map_open(struct inode *inode, struct file *file, 2937 struct seq_operations *seq_ops) 2938 { 2939 struct user_namespace *ns = NULL; 2940 struct task_struct *task; 2941 struct seq_file *seq; 2942 int ret = -EINVAL; 2943 2944 task = get_proc_task(inode); 2945 if (task) { 2946 rcu_read_lock(); 2947 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2948 rcu_read_unlock(); 2949 put_task_struct(task); 2950 } 2951 if (!ns) 2952 goto err; 2953 2954 ret = seq_open(file, seq_ops); 2955 if (ret) 2956 goto err_put_ns; 2957 2958 seq = file->private_data; 2959 seq->private = ns; 2960 2961 return 0; 2962 err_put_ns: 2963 put_user_ns(ns); 2964 err: 2965 return ret; 2966 } 2967 2968 static int proc_id_map_release(struct inode *inode, struct file *file) 2969 { 2970 struct seq_file *seq = file->private_data; 2971 struct user_namespace *ns = seq->private; 2972 put_user_ns(ns); 2973 return seq_release(inode, file); 2974 } 2975 2976 static int proc_uid_map_open(struct inode *inode, struct file *file) 2977 { 2978 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2979 } 2980 2981 static int proc_gid_map_open(struct inode *inode, struct file *file) 2982 { 2983 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2984 } 2985 2986 static const struct file_operations proc_uid_map_operations = { 2987 .open = proc_uid_map_open, 2988 .write = proc_uid_map_write, 2989 .read = seq_read, 2990 .llseek = seq_lseek, 2991 .release = proc_id_map_release, 2992 }; 2993 2994 static const struct file_operations proc_gid_map_operations = { 2995 .open = proc_gid_map_open, 2996 .write = proc_gid_map_write, 2997 .read = seq_read, 2998 .llseek = seq_lseek, 2999 .release = proc_id_map_release, 3000 }; 3001 #endif /* CONFIG_USER_NS */ 3002 3003 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 3004 struct pid *pid, struct task_struct *task) 3005 { 3006 int err = lock_trace(task); 3007 if (!err) { 3008 seq_printf(m, "%08x\n", task->personality); 3009 unlock_trace(task); 3010 } 3011 return err; 3012 } 3013 3014 /* 3015 * Thread groups 3016 */ 3017 static const struct file_operations proc_task_operations; 3018 static const struct inode_operations proc_task_inode_operations; 3019 3020 static const struct pid_entry tgid_base_stuff[] = { 3021 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 3022 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3023 #ifdef CONFIG_CHECKPOINT_RESTORE 3024 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 3025 #endif 3026 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3027 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3028 #ifdef CONFIG_NET 3029 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3030 #endif 3031 REG("environ", S_IRUSR, proc_environ_operations), 3032 INF("auxv", S_IRUSR, proc_pid_auxv), 3033 ONE("status", S_IRUGO, proc_pid_status), 3034 ONE("personality", S_IRUGO, proc_pid_personality), 3035 INF("limits", S_IRUGO, proc_pid_limits), 3036 #ifdef CONFIG_SCHED_DEBUG 3037 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3038 #endif 3039 #ifdef CONFIG_SCHED_AUTOGROUP 3040 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 3041 #endif 3042 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3043 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3044 INF("syscall", S_IRUGO, proc_pid_syscall), 3045 #endif 3046 INF("cmdline", S_IRUGO, proc_pid_cmdline), 3047 ONE("stat", S_IRUGO, proc_tgid_stat), 3048 ONE("statm", S_IRUGO, proc_pid_statm), 3049 REG("maps", S_IRUGO, proc_pid_maps_operations), 3050 #ifdef CONFIG_NUMA 3051 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 3052 #endif 3053 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3054 LNK("cwd", proc_cwd_link), 3055 LNK("root", proc_root_link), 3056 LNK("exe", proc_exe_link), 3057 REG("mounts", S_IRUGO, proc_mounts_operations), 3058 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3059 REG("mountstats", S_IRUSR, proc_mountstats_operations), 3060 #ifdef CONFIG_PROC_PAGE_MONITOR 3061 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3062 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 3063 REG("pagemap", S_IRUGO, proc_pagemap_operations), 3064 #endif 3065 #ifdef CONFIG_SECURITY 3066 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3067 #endif 3068 #ifdef CONFIG_KALLSYMS 3069 INF("wchan", S_IRUGO, proc_pid_wchan), 3070 #endif 3071 #ifdef CONFIG_STACKTRACE 3072 ONE("stack", S_IRUGO, proc_pid_stack), 3073 #endif 3074 #ifdef CONFIG_SCHEDSTATS 3075 INF("schedstat", S_IRUGO, proc_pid_schedstat), 3076 #endif 3077 #ifdef CONFIG_LATENCYTOP 3078 REG("latency", S_IRUGO, proc_lstats_operations), 3079 #endif 3080 #ifdef CONFIG_PROC_PID_CPUSET 3081 REG("cpuset", S_IRUGO, proc_cpuset_operations), 3082 #endif 3083 #ifdef CONFIG_CGROUPS 3084 REG("cgroup", S_IRUGO, proc_cgroup_operations), 3085 #endif 3086 INF("oom_score", S_IRUGO, proc_oom_score), 3087 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 3088 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3089 #ifdef CONFIG_AUDITSYSCALL 3090 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3091 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3092 #endif 3093 #ifdef CONFIG_FAULT_INJECTION 3094 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3095 #endif 3096 #ifdef CONFIG_ELF_CORE 3097 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 3098 #endif 3099 #ifdef CONFIG_TASK_IO_ACCOUNTING 3100 INF("io", S_IRUSR, proc_tgid_io_accounting), 3101 #endif 3102 #ifdef CONFIG_HARDWALL 3103 INF("hardwall", S_IRUGO, proc_pid_hardwall), 3104 #endif 3105 #ifdef CONFIG_USER_NS 3106 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3107 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3108 #endif 3109 }; 3110 3111 static int proc_tgid_base_readdir(struct file * filp, 3112 void * dirent, filldir_t filldir) 3113 { 3114 return proc_pident_readdir(filp,dirent,filldir, 3115 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 3116 } 3117 3118 static const struct file_operations proc_tgid_base_operations = { 3119 .read = generic_read_dir, 3120 .readdir = proc_tgid_base_readdir, 3121 .llseek = default_llseek, 3122 }; 3123 3124 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3125 { 3126 return proc_pident_lookup(dir, dentry, 3127 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3128 } 3129 3130 static const struct inode_operations proc_tgid_base_inode_operations = { 3131 .lookup = proc_tgid_base_lookup, 3132 .getattr = pid_getattr, 3133 .setattr = proc_setattr, 3134 .permission = proc_pid_permission, 3135 }; 3136 3137 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 3138 { 3139 struct dentry *dentry, *leader, *dir; 3140 char buf[PROC_NUMBUF]; 3141 struct qstr name; 3142 3143 name.name = buf; 3144 name.len = snprintf(buf, sizeof(buf), "%d", pid); 3145 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 3146 if (dentry) { 3147 shrink_dcache_parent(dentry); 3148 d_drop(dentry); 3149 dput(dentry); 3150 } 3151 3152 name.name = buf; 3153 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 3154 leader = d_hash_and_lookup(mnt->mnt_root, &name); 3155 if (!leader) 3156 goto out; 3157 3158 name.name = "task"; 3159 name.len = strlen(name.name); 3160 dir = d_hash_and_lookup(leader, &name); 3161 if (!dir) 3162 goto out_put_leader; 3163 3164 name.name = buf; 3165 name.len = snprintf(buf, sizeof(buf), "%d", pid); 3166 dentry = d_hash_and_lookup(dir, &name); 3167 if (dentry) { 3168 shrink_dcache_parent(dentry); 3169 d_drop(dentry); 3170 dput(dentry); 3171 } 3172 3173 dput(dir); 3174 out_put_leader: 3175 dput(leader); 3176 out: 3177 return; 3178 } 3179 3180 /** 3181 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 3182 * @task: task that should be flushed. 3183 * 3184 * When flushing dentries from proc, one needs to flush them from global 3185 * proc (proc_mnt) and from all the namespaces' procs this task was seen 3186 * in. This call is supposed to do all of this job. 3187 * 3188 * Looks in the dcache for 3189 * /proc/@pid 3190 * /proc/@tgid/task/@pid 3191 * if either directory is present flushes it and all of it'ts children 3192 * from the dcache. 3193 * 3194 * It is safe and reasonable to cache /proc entries for a task until 3195 * that task exits. After that they just clog up the dcache with 3196 * useless entries, possibly causing useful dcache entries to be 3197 * flushed instead. This routine is proved to flush those useless 3198 * dcache entries at process exit time. 3199 * 3200 * NOTE: This routine is just an optimization so it does not guarantee 3201 * that no dcache entries will exist at process exit time it 3202 * just makes it very unlikely that any will persist. 3203 */ 3204 3205 void proc_flush_task(struct task_struct *task) 3206 { 3207 int i; 3208 struct pid *pid, *tgid; 3209 struct upid *upid; 3210 3211 pid = task_pid(task); 3212 tgid = task_tgid(task); 3213 3214 for (i = 0; i <= pid->level; i++) { 3215 upid = &pid->numbers[i]; 3216 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3217 tgid->numbers[i].nr); 3218 } 3219 3220 upid = &pid->numbers[pid->level]; 3221 if (upid->nr == 1) 3222 pid_ns_release_proc(upid->ns); 3223 } 3224 3225 static struct dentry *proc_pid_instantiate(struct inode *dir, 3226 struct dentry * dentry, 3227 struct task_struct *task, const void *ptr) 3228 { 3229 struct dentry *error = ERR_PTR(-ENOENT); 3230 struct inode *inode; 3231 3232 inode = proc_pid_make_inode(dir->i_sb, task); 3233 if (!inode) 3234 goto out; 3235 3236 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3237 inode->i_op = &proc_tgid_base_inode_operations; 3238 inode->i_fop = &proc_tgid_base_operations; 3239 inode->i_flags|=S_IMMUTABLE; 3240 3241 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff, 3242 ARRAY_SIZE(tgid_base_stuff))); 3243 3244 d_set_d_op(dentry, &pid_dentry_operations); 3245 3246 d_add(dentry, inode); 3247 /* Close the race of the process dying before we return the dentry */ 3248 if (pid_revalidate(dentry, 0)) 3249 error = NULL; 3250 out: 3251 return error; 3252 } 3253 3254 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3255 { 3256 struct dentry *result; 3257 struct task_struct *task; 3258 unsigned tgid; 3259 struct pid_namespace *ns; 3260 3261 result = proc_base_lookup(dir, dentry); 3262 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 3263 goto out; 3264 3265 tgid = name_to_int(dentry); 3266 if (tgid == ~0U) 3267 goto out; 3268 3269 ns = dentry->d_sb->s_fs_info; 3270 rcu_read_lock(); 3271 task = find_task_by_pid_ns(tgid, ns); 3272 if (task) 3273 get_task_struct(task); 3274 rcu_read_unlock(); 3275 if (!task) 3276 goto out; 3277 3278 result = proc_pid_instantiate(dir, dentry, task, NULL); 3279 put_task_struct(task); 3280 out: 3281 return result; 3282 } 3283 3284 /* 3285 * Find the first task with tgid >= tgid 3286 * 3287 */ 3288 struct tgid_iter { 3289 unsigned int tgid; 3290 struct task_struct *task; 3291 }; 3292 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3293 { 3294 struct pid *pid; 3295 3296 if (iter.task) 3297 put_task_struct(iter.task); 3298 rcu_read_lock(); 3299 retry: 3300 iter.task = NULL; 3301 pid = find_ge_pid(iter.tgid, ns); 3302 if (pid) { 3303 iter.tgid = pid_nr_ns(pid, ns); 3304 iter.task = pid_task(pid, PIDTYPE_PID); 3305 /* What we to know is if the pid we have find is the 3306 * pid of a thread_group_leader. Testing for task 3307 * being a thread_group_leader is the obvious thing 3308 * todo but there is a window when it fails, due to 3309 * the pid transfer logic in de_thread. 3310 * 3311 * So we perform the straight forward test of seeing 3312 * if the pid we have found is the pid of a thread 3313 * group leader, and don't worry if the task we have 3314 * found doesn't happen to be a thread group leader. 3315 * As we don't care in the case of readdir. 3316 */ 3317 if (!iter.task || !has_group_leader_pid(iter.task)) { 3318 iter.tgid += 1; 3319 goto retry; 3320 } 3321 get_task_struct(iter.task); 3322 } 3323 rcu_read_unlock(); 3324 return iter; 3325 } 3326 3327 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 3328 3329 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3330 struct tgid_iter iter) 3331 { 3332 char name[PROC_NUMBUF]; 3333 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 3334 return proc_fill_cache(filp, dirent, filldir, name, len, 3335 proc_pid_instantiate, iter.task, NULL); 3336 } 3337 3338 static int fake_filldir(void *buf, const char *name, int namelen, 3339 loff_t offset, u64 ino, unsigned d_type) 3340 { 3341 return 0; 3342 } 3343 3344 /* for the /proc/ directory itself, after non-process stuff has been done */ 3345 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 3346 { 3347 unsigned int nr; 3348 struct task_struct *reaper; 3349 struct tgid_iter iter; 3350 struct pid_namespace *ns; 3351 filldir_t __filldir; 3352 3353 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET) 3354 goto out_no_task; 3355 nr = filp->f_pos - FIRST_PROCESS_ENTRY; 3356 3357 reaper = get_proc_task(filp->f_path.dentry->d_inode); 3358 if (!reaper) 3359 goto out_no_task; 3360 3361 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 3362 const struct pid_entry *p = &proc_base_stuff[nr]; 3363 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 3364 goto out; 3365 } 3366 3367 ns = filp->f_dentry->d_sb->s_fs_info; 3368 iter.task = NULL; 3369 iter.tgid = filp->f_pos - TGID_OFFSET; 3370 for (iter = next_tgid(ns, iter); 3371 iter.task; 3372 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3373 if (has_pid_permissions(ns, iter.task, 2)) 3374 __filldir = filldir; 3375 else 3376 __filldir = fake_filldir; 3377 3378 filp->f_pos = iter.tgid + TGID_OFFSET; 3379 if (proc_pid_fill_cache(filp, dirent, __filldir, iter) < 0) { 3380 put_task_struct(iter.task); 3381 goto out; 3382 } 3383 } 3384 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 3385 out: 3386 put_task_struct(reaper); 3387 out_no_task: 3388 return 0; 3389 } 3390 3391 /* 3392 * Tasks 3393 */ 3394 static const struct pid_entry tid_base_stuff[] = { 3395 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3396 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3397 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3398 REG("environ", S_IRUSR, proc_environ_operations), 3399 INF("auxv", S_IRUSR, proc_pid_auxv), 3400 ONE("status", S_IRUGO, proc_pid_status), 3401 ONE("personality", S_IRUGO, proc_pid_personality), 3402 INF("limits", S_IRUGO, proc_pid_limits), 3403 #ifdef CONFIG_SCHED_DEBUG 3404 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3405 #endif 3406 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3407 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3408 INF("syscall", S_IRUGO, proc_pid_syscall), 3409 #endif 3410 INF("cmdline", S_IRUGO, proc_pid_cmdline), 3411 ONE("stat", S_IRUGO, proc_tid_stat), 3412 ONE("statm", S_IRUGO, proc_pid_statm), 3413 REG("maps", S_IRUGO, proc_tid_maps_operations), 3414 #ifdef CONFIG_CHECKPOINT_RESTORE 3415 REG("children", S_IRUGO, proc_tid_children_operations), 3416 #endif 3417 #ifdef CONFIG_NUMA 3418 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations), 3419 #endif 3420 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3421 LNK("cwd", proc_cwd_link), 3422 LNK("root", proc_root_link), 3423 LNK("exe", proc_exe_link), 3424 REG("mounts", S_IRUGO, proc_mounts_operations), 3425 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3426 #ifdef CONFIG_PROC_PAGE_MONITOR 3427 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3428 REG("smaps", S_IRUGO, proc_tid_smaps_operations), 3429 REG("pagemap", S_IRUGO, proc_pagemap_operations), 3430 #endif 3431 #ifdef CONFIG_SECURITY 3432 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3433 #endif 3434 #ifdef CONFIG_KALLSYMS 3435 INF("wchan", S_IRUGO, proc_pid_wchan), 3436 #endif 3437 #ifdef CONFIG_STACKTRACE 3438 ONE("stack", S_IRUGO, proc_pid_stack), 3439 #endif 3440 #ifdef CONFIG_SCHEDSTATS 3441 INF("schedstat", S_IRUGO, proc_pid_schedstat), 3442 #endif 3443 #ifdef CONFIG_LATENCYTOP 3444 REG("latency", S_IRUGO, proc_lstats_operations), 3445 #endif 3446 #ifdef CONFIG_PROC_PID_CPUSET 3447 REG("cpuset", S_IRUGO, proc_cpuset_operations), 3448 #endif 3449 #ifdef CONFIG_CGROUPS 3450 REG("cgroup", S_IRUGO, proc_cgroup_operations), 3451 #endif 3452 INF("oom_score", S_IRUGO, proc_oom_score), 3453 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 3454 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3455 #ifdef CONFIG_AUDITSYSCALL 3456 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3457 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3458 #endif 3459 #ifdef CONFIG_FAULT_INJECTION 3460 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3461 #endif 3462 #ifdef CONFIG_TASK_IO_ACCOUNTING 3463 INF("io", S_IRUSR, proc_tid_io_accounting), 3464 #endif 3465 #ifdef CONFIG_HARDWALL 3466 INF("hardwall", S_IRUGO, proc_pid_hardwall), 3467 #endif 3468 #ifdef CONFIG_USER_NS 3469 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3470 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3471 #endif 3472 }; 3473 3474 static int proc_tid_base_readdir(struct file * filp, 3475 void * dirent, filldir_t filldir) 3476 { 3477 return proc_pident_readdir(filp,dirent,filldir, 3478 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 3479 } 3480 3481 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3482 { 3483 return proc_pident_lookup(dir, dentry, 3484 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3485 } 3486 3487 static const struct file_operations proc_tid_base_operations = { 3488 .read = generic_read_dir, 3489 .readdir = proc_tid_base_readdir, 3490 .llseek = default_llseek, 3491 }; 3492 3493 static const struct inode_operations proc_tid_base_inode_operations = { 3494 .lookup = proc_tid_base_lookup, 3495 .getattr = pid_getattr, 3496 .setattr = proc_setattr, 3497 }; 3498 3499 static struct dentry *proc_task_instantiate(struct inode *dir, 3500 struct dentry *dentry, struct task_struct *task, const void *ptr) 3501 { 3502 struct dentry *error = ERR_PTR(-ENOENT); 3503 struct inode *inode; 3504 inode = proc_pid_make_inode(dir->i_sb, task); 3505 3506 if (!inode) 3507 goto out; 3508 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3509 inode->i_op = &proc_tid_base_inode_operations; 3510 inode->i_fop = &proc_tid_base_operations; 3511 inode->i_flags|=S_IMMUTABLE; 3512 3513 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff, 3514 ARRAY_SIZE(tid_base_stuff))); 3515 3516 d_set_d_op(dentry, &pid_dentry_operations); 3517 3518 d_add(dentry, inode); 3519 /* Close the race of the process dying before we return the dentry */ 3520 if (pid_revalidate(dentry, 0)) 3521 error = NULL; 3522 out: 3523 return error; 3524 } 3525 3526 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3527 { 3528 struct dentry *result = ERR_PTR(-ENOENT); 3529 struct task_struct *task; 3530 struct task_struct *leader = get_proc_task(dir); 3531 unsigned tid; 3532 struct pid_namespace *ns; 3533 3534 if (!leader) 3535 goto out_no_task; 3536 3537 tid = name_to_int(dentry); 3538 if (tid == ~0U) 3539 goto out; 3540 3541 ns = dentry->d_sb->s_fs_info; 3542 rcu_read_lock(); 3543 task = find_task_by_pid_ns(tid, ns); 3544 if (task) 3545 get_task_struct(task); 3546 rcu_read_unlock(); 3547 if (!task) 3548 goto out; 3549 if (!same_thread_group(leader, task)) 3550 goto out_drop_task; 3551 3552 result = proc_task_instantiate(dir, dentry, task, NULL); 3553 out_drop_task: 3554 put_task_struct(task); 3555 out: 3556 put_task_struct(leader); 3557 out_no_task: 3558 return result; 3559 } 3560 3561 /* 3562 * Find the first tid of a thread group to return to user space. 3563 * 3564 * Usually this is just the thread group leader, but if the users 3565 * buffer was too small or there was a seek into the middle of the 3566 * directory we have more work todo. 3567 * 3568 * In the case of a short read we start with find_task_by_pid. 3569 * 3570 * In the case of a seek we start with the leader and walk nr 3571 * threads past it. 3572 */ 3573 static struct task_struct *first_tid(struct task_struct *leader, 3574 int tid, int nr, struct pid_namespace *ns) 3575 { 3576 struct task_struct *pos; 3577 3578 rcu_read_lock(); 3579 /* Attempt to start with the pid of a thread */ 3580 if (tid && (nr > 0)) { 3581 pos = find_task_by_pid_ns(tid, ns); 3582 if (pos && (pos->group_leader == leader)) 3583 goto found; 3584 } 3585 3586 /* If nr exceeds the number of threads there is nothing todo */ 3587 pos = NULL; 3588 if (nr && nr >= get_nr_threads(leader)) 3589 goto out; 3590 3591 /* If we haven't found our starting place yet start 3592 * with the leader and walk nr threads forward. 3593 */ 3594 for (pos = leader; nr > 0; --nr) { 3595 pos = next_thread(pos); 3596 if (pos == leader) { 3597 pos = NULL; 3598 goto out; 3599 } 3600 } 3601 found: 3602 get_task_struct(pos); 3603 out: 3604 rcu_read_unlock(); 3605 return pos; 3606 } 3607 3608 /* 3609 * Find the next thread in the thread list. 3610 * Return NULL if there is an error or no next thread. 3611 * 3612 * The reference to the input task_struct is released. 3613 */ 3614 static struct task_struct *next_tid(struct task_struct *start) 3615 { 3616 struct task_struct *pos = NULL; 3617 rcu_read_lock(); 3618 if (pid_alive(start)) { 3619 pos = next_thread(start); 3620 if (thread_group_leader(pos)) 3621 pos = NULL; 3622 else 3623 get_task_struct(pos); 3624 } 3625 rcu_read_unlock(); 3626 put_task_struct(start); 3627 return pos; 3628 } 3629 3630 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3631 struct task_struct *task, int tid) 3632 { 3633 char name[PROC_NUMBUF]; 3634 int len = snprintf(name, sizeof(name), "%d", tid); 3635 return proc_fill_cache(filp, dirent, filldir, name, len, 3636 proc_task_instantiate, task, NULL); 3637 } 3638 3639 /* for the /proc/TGID/task/ directories */ 3640 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 3641 { 3642 struct dentry *dentry = filp->f_path.dentry; 3643 struct inode *inode = dentry->d_inode; 3644 struct task_struct *leader = NULL; 3645 struct task_struct *task; 3646 int retval = -ENOENT; 3647 ino_t ino; 3648 int tid; 3649 struct pid_namespace *ns; 3650 3651 task = get_proc_task(inode); 3652 if (!task) 3653 goto out_no_task; 3654 rcu_read_lock(); 3655 if (pid_alive(task)) { 3656 leader = task->group_leader; 3657 get_task_struct(leader); 3658 } 3659 rcu_read_unlock(); 3660 put_task_struct(task); 3661 if (!leader) 3662 goto out_no_task; 3663 retval = 0; 3664 3665 switch ((unsigned long)filp->f_pos) { 3666 case 0: 3667 ino = inode->i_ino; 3668 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0) 3669 goto out; 3670 filp->f_pos++; 3671 /* fall through */ 3672 case 1: 3673 ino = parent_ino(dentry); 3674 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0) 3675 goto out; 3676 filp->f_pos++; 3677 /* fall through */ 3678 } 3679 3680 /* f_version caches the tgid value that the last readdir call couldn't 3681 * return. lseek aka telldir automagically resets f_version to 0. 3682 */ 3683 ns = filp->f_dentry->d_sb->s_fs_info; 3684 tid = (int)filp->f_version; 3685 filp->f_version = 0; 3686 for (task = first_tid(leader, tid, filp->f_pos - 2, ns); 3687 task; 3688 task = next_tid(task), filp->f_pos++) { 3689 tid = task_pid_nr_ns(task, ns); 3690 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 3691 /* returning this tgid failed, save it as the first 3692 * pid for the next readir call */ 3693 filp->f_version = (u64)tid; 3694 put_task_struct(task); 3695 break; 3696 } 3697 } 3698 out: 3699 put_task_struct(leader); 3700 out_no_task: 3701 return retval; 3702 } 3703 3704 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3705 { 3706 struct inode *inode = dentry->d_inode; 3707 struct task_struct *p = get_proc_task(inode); 3708 generic_fillattr(inode, stat); 3709 3710 if (p) { 3711 stat->nlink += get_nr_threads(p); 3712 put_task_struct(p); 3713 } 3714 3715 return 0; 3716 } 3717 3718 static const struct inode_operations proc_task_inode_operations = { 3719 .lookup = proc_task_lookup, 3720 .getattr = proc_task_getattr, 3721 .setattr = proc_setattr, 3722 .permission = proc_pid_permission, 3723 }; 3724 3725 static const struct file_operations proc_task_operations = { 3726 .read = generic_read_dir, 3727 .readdir = proc_task_readdir, 3728 .llseek = default_llseek, 3729 }; 3730