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 /* OK to pass negative loff_t, we can catch out-of-range */ 699 file->f_mode |= FMODE_UNSIGNED_OFFSET; 700 file->private_data = mm; 701 702 return 0; 703 } 704 705 static int mem_open(struct inode *inode, struct file *file) 706 { 707 return __mem_open(inode, file, PTRACE_MODE_ATTACH); 708 } 709 710 static ssize_t mem_rw(struct file *file, char __user *buf, 711 size_t count, loff_t *ppos, int write) 712 { 713 struct mm_struct *mm = file->private_data; 714 unsigned long addr = *ppos; 715 ssize_t copied; 716 char *page; 717 718 if (!mm) 719 return 0; 720 721 page = (char *)__get_free_page(GFP_TEMPORARY); 722 if (!page) 723 return -ENOMEM; 724 725 copied = 0; 726 if (!atomic_inc_not_zero(&mm->mm_users)) 727 goto free; 728 729 while (count > 0) { 730 int this_len = min_t(int, count, PAGE_SIZE); 731 732 if (write && copy_from_user(page, buf, this_len)) { 733 copied = -EFAULT; 734 break; 735 } 736 737 this_len = access_remote_vm(mm, addr, page, this_len, write); 738 if (!this_len) { 739 if (!copied) 740 copied = -EIO; 741 break; 742 } 743 744 if (!write && copy_to_user(buf, page, this_len)) { 745 copied = -EFAULT; 746 break; 747 } 748 749 buf += this_len; 750 addr += this_len; 751 copied += this_len; 752 count -= this_len; 753 } 754 *ppos = addr; 755 756 mmput(mm); 757 free: 758 free_page((unsigned long) page); 759 return copied; 760 } 761 762 static ssize_t mem_read(struct file *file, char __user *buf, 763 size_t count, loff_t *ppos) 764 { 765 return mem_rw(file, buf, count, ppos, 0); 766 } 767 768 static ssize_t mem_write(struct file *file, const char __user *buf, 769 size_t count, loff_t *ppos) 770 { 771 return mem_rw(file, (char __user*)buf, count, ppos, 1); 772 } 773 774 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 775 { 776 switch (orig) { 777 case 0: 778 file->f_pos = offset; 779 break; 780 case 1: 781 file->f_pos += offset; 782 break; 783 default: 784 return -EINVAL; 785 } 786 force_successful_syscall_return(); 787 return file->f_pos; 788 } 789 790 static int mem_release(struct inode *inode, struct file *file) 791 { 792 struct mm_struct *mm = file->private_data; 793 if (mm) 794 mmdrop(mm); 795 return 0; 796 } 797 798 static const struct file_operations proc_mem_operations = { 799 .llseek = mem_lseek, 800 .read = mem_read, 801 .write = mem_write, 802 .open = mem_open, 803 .release = mem_release, 804 }; 805 806 static int environ_open(struct inode *inode, struct file *file) 807 { 808 return __mem_open(inode, file, PTRACE_MODE_READ); 809 } 810 811 static ssize_t environ_read(struct file *file, char __user *buf, 812 size_t count, loff_t *ppos) 813 { 814 char *page; 815 unsigned long src = *ppos; 816 int ret = 0; 817 struct mm_struct *mm = file->private_data; 818 819 if (!mm) 820 return 0; 821 822 page = (char *)__get_free_page(GFP_TEMPORARY); 823 if (!page) 824 return -ENOMEM; 825 826 ret = 0; 827 if (!atomic_inc_not_zero(&mm->mm_users)) 828 goto free; 829 while (count > 0) { 830 int this_len, retval, max_len; 831 832 this_len = mm->env_end - (mm->env_start + src); 833 834 if (this_len <= 0) 835 break; 836 837 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 838 this_len = (this_len > max_len) ? max_len : this_len; 839 840 retval = access_remote_vm(mm, (mm->env_start + src), 841 page, this_len, 0); 842 843 if (retval <= 0) { 844 ret = retval; 845 break; 846 } 847 848 if (copy_to_user(buf, page, retval)) { 849 ret = -EFAULT; 850 break; 851 } 852 853 ret += retval; 854 src += retval; 855 buf += retval; 856 count -= retval; 857 } 858 *ppos = src; 859 mmput(mm); 860 861 free: 862 free_page((unsigned long) page); 863 return ret; 864 } 865 866 static const struct file_operations proc_environ_operations = { 867 .open = environ_open, 868 .read = environ_read, 869 .llseek = generic_file_llseek, 870 .release = mem_release, 871 }; 872 873 static ssize_t oom_adjust_read(struct file *file, char __user *buf, 874 size_t count, loff_t *ppos) 875 { 876 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 877 char buffer[PROC_NUMBUF]; 878 size_t len; 879 int oom_adjust = OOM_DISABLE; 880 unsigned long flags; 881 882 if (!task) 883 return -ESRCH; 884 885 if (lock_task_sighand(task, &flags)) { 886 oom_adjust = task->signal->oom_adj; 887 unlock_task_sighand(task, &flags); 888 } 889 890 put_task_struct(task); 891 892 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); 893 894 return simple_read_from_buffer(buf, count, ppos, buffer, len); 895 } 896 897 static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 898 size_t count, loff_t *ppos) 899 { 900 struct task_struct *task; 901 char buffer[PROC_NUMBUF]; 902 int oom_adjust; 903 unsigned long flags; 904 int err; 905 906 memset(buffer, 0, sizeof(buffer)); 907 if (count > sizeof(buffer) - 1) 908 count = sizeof(buffer) - 1; 909 if (copy_from_user(buffer, buf, count)) { 910 err = -EFAULT; 911 goto out; 912 } 913 914 err = kstrtoint(strstrip(buffer), 0, &oom_adjust); 915 if (err) 916 goto out; 917 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && 918 oom_adjust != OOM_DISABLE) { 919 err = -EINVAL; 920 goto out; 921 } 922 923 task = get_proc_task(file->f_path.dentry->d_inode); 924 if (!task) { 925 err = -ESRCH; 926 goto out; 927 } 928 929 task_lock(task); 930 if (!task->mm) { 931 err = -EINVAL; 932 goto err_task_lock; 933 } 934 935 if (!lock_task_sighand(task, &flags)) { 936 err = -ESRCH; 937 goto err_task_lock; 938 } 939 940 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) { 941 err = -EACCES; 942 goto err_sighand; 943 } 944 945 /* 946 * Warn that /proc/pid/oom_adj is deprecated, see 947 * Documentation/feature-removal-schedule.txt. 948 */ 949 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 950 current->comm, task_pid_nr(current), task_pid_nr(task), 951 task_pid_nr(task)); 952 task->signal->oom_adj = oom_adjust; 953 /* 954 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 955 * value is always attainable. 956 */ 957 if (task->signal->oom_adj == OOM_ADJUST_MAX) 958 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX; 959 else 960 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) / 961 -OOM_DISABLE; 962 trace_oom_score_adj_update(task); 963 err_sighand: 964 unlock_task_sighand(task, &flags); 965 err_task_lock: 966 task_unlock(task); 967 put_task_struct(task); 968 out: 969 return err < 0 ? err : count; 970 } 971 972 static const struct file_operations proc_oom_adjust_operations = { 973 .read = oom_adjust_read, 974 .write = oom_adjust_write, 975 .llseek = generic_file_llseek, 976 }; 977 978 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 979 size_t count, loff_t *ppos) 980 { 981 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 982 char buffer[PROC_NUMBUF]; 983 int oom_score_adj = OOM_SCORE_ADJ_MIN; 984 unsigned long flags; 985 size_t len; 986 987 if (!task) 988 return -ESRCH; 989 if (lock_task_sighand(task, &flags)) { 990 oom_score_adj = task->signal->oom_score_adj; 991 unlock_task_sighand(task, &flags); 992 } 993 put_task_struct(task); 994 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj); 995 return simple_read_from_buffer(buf, count, ppos, buffer, len); 996 } 997 998 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 999 size_t count, loff_t *ppos) 1000 { 1001 struct task_struct *task; 1002 char buffer[PROC_NUMBUF]; 1003 unsigned long flags; 1004 int oom_score_adj; 1005 int err; 1006 1007 memset(buffer, 0, sizeof(buffer)); 1008 if (count > sizeof(buffer) - 1) 1009 count = sizeof(buffer) - 1; 1010 if (copy_from_user(buffer, buf, count)) { 1011 err = -EFAULT; 1012 goto out; 1013 } 1014 1015 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 1016 if (err) 1017 goto out; 1018 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1019 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1020 err = -EINVAL; 1021 goto out; 1022 } 1023 1024 task = get_proc_task(file->f_path.dentry->d_inode); 1025 if (!task) { 1026 err = -ESRCH; 1027 goto out; 1028 } 1029 1030 task_lock(task); 1031 if (!task->mm) { 1032 err = -EINVAL; 1033 goto err_task_lock; 1034 } 1035 1036 if (!lock_task_sighand(task, &flags)) { 1037 err = -ESRCH; 1038 goto err_task_lock; 1039 } 1040 1041 if (oom_score_adj < task->signal->oom_score_adj_min && 1042 !capable(CAP_SYS_RESOURCE)) { 1043 err = -EACCES; 1044 goto err_sighand; 1045 } 1046 1047 task->signal->oom_score_adj = oom_score_adj; 1048 if (has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1049 task->signal->oom_score_adj_min = oom_score_adj; 1050 trace_oom_score_adj_update(task); 1051 /* 1052 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is 1053 * always attainable. 1054 */ 1055 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) 1056 task->signal->oom_adj = OOM_DISABLE; 1057 else 1058 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) / 1059 OOM_SCORE_ADJ_MAX; 1060 err_sighand: 1061 unlock_task_sighand(task, &flags); 1062 err_task_lock: 1063 task_unlock(task); 1064 put_task_struct(task); 1065 out: 1066 return err < 0 ? err : count; 1067 } 1068 1069 static const struct file_operations proc_oom_score_adj_operations = { 1070 .read = oom_score_adj_read, 1071 .write = oom_score_adj_write, 1072 .llseek = default_llseek, 1073 }; 1074 1075 #ifdef CONFIG_AUDITSYSCALL 1076 #define TMPBUFLEN 21 1077 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1078 size_t count, loff_t *ppos) 1079 { 1080 struct inode * inode = file->f_path.dentry->d_inode; 1081 struct task_struct *task = get_proc_task(inode); 1082 ssize_t length; 1083 char tmpbuf[TMPBUFLEN]; 1084 1085 if (!task) 1086 return -ESRCH; 1087 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1088 audit_get_loginuid(task)); 1089 put_task_struct(task); 1090 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1091 } 1092 1093 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1094 size_t count, loff_t *ppos) 1095 { 1096 struct inode * inode = file->f_path.dentry->d_inode; 1097 char *page, *tmp; 1098 ssize_t length; 1099 uid_t loginuid; 1100 1101 rcu_read_lock(); 1102 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1103 rcu_read_unlock(); 1104 return -EPERM; 1105 } 1106 rcu_read_unlock(); 1107 1108 if (count >= PAGE_SIZE) 1109 count = PAGE_SIZE - 1; 1110 1111 if (*ppos != 0) { 1112 /* No partial writes. */ 1113 return -EINVAL; 1114 } 1115 page = (char*)__get_free_page(GFP_TEMPORARY); 1116 if (!page) 1117 return -ENOMEM; 1118 length = -EFAULT; 1119 if (copy_from_user(page, buf, count)) 1120 goto out_free_page; 1121 1122 page[count] = '\0'; 1123 loginuid = simple_strtoul(page, &tmp, 10); 1124 if (tmp == page) { 1125 length = -EINVAL; 1126 goto out_free_page; 1127 1128 } 1129 length = audit_set_loginuid(loginuid); 1130 if (likely(length == 0)) 1131 length = count; 1132 1133 out_free_page: 1134 free_page((unsigned long) page); 1135 return length; 1136 } 1137 1138 static const struct file_operations proc_loginuid_operations = { 1139 .read = proc_loginuid_read, 1140 .write = proc_loginuid_write, 1141 .llseek = generic_file_llseek, 1142 }; 1143 1144 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1145 size_t count, loff_t *ppos) 1146 { 1147 struct inode * inode = file->f_path.dentry->d_inode; 1148 struct task_struct *task = get_proc_task(inode); 1149 ssize_t length; 1150 char tmpbuf[TMPBUFLEN]; 1151 1152 if (!task) 1153 return -ESRCH; 1154 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1155 audit_get_sessionid(task)); 1156 put_task_struct(task); 1157 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1158 } 1159 1160 static const struct file_operations proc_sessionid_operations = { 1161 .read = proc_sessionid_read, 1162 .llseek = generic_file_llseek, 1163 }; 1164 #endif 1165 1166 #ifdef CONFIG_FAULT_INJECTION 1167 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1168 size_t count, loff_t *ppos) 1169 { 1170 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1171 char buffer[PROC_NUMBUF]; 1172 size_t len; 1173 int make_it_fail; 1174 1175 if (!task) 1176 return -ESRCH; 1177 make_it_fail = task->make_it_fail; 1178 put_task_struct(task); 1179 1180 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1181 1182 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1183 } 1184 1185 static ssize_t proc_fault_inject_write(struct file * file, 1186 const char __user * buf, size_t count, loff_t *ppos) 1187 { 1188 struct task_struct *task; 1189 char buffer[PROC_NUMBUF], *end; 1190 int make_it_fail; 1191 1192 if (!capable(CAP_SYS_RESOURCE)) 1193 return -EPERM; 1194 memset(buffer, 0, sizeof(buffer)); 1195 if (count > sizeof(buffer) - 1) 1196 count = sizeof(buffer) - 1; 1197 if (copy_from_user(buffer, buf, count)) 1198 return -EFAULT; 1199 make_it_fail = simple_strtol(strstrip(buffer), &end, 0); 1200 if (*end) 1201 return -EINVAL; 1202 task = get_proc_task(file->f_dentry->d_inode); 1203 if (!task) 1204 return -ESRCH; 1205 task->make_it_fail = make_it_fail; 1206 put_task_struct(task); 1207 1208 return count; 1209 } 1210 1211 static const struct file_operations proc_fault_inject_operations = { 1212 .read = proc_fault_inject_read, 1213 .write = proc_fault_inject_write, 1214 .llseek = generic_file_llseek, 1215 }; 1216 #endif 1217 1218 1219 #ifdef CONFIG_SCHED_DEBUG 1220 /* 1221 * Print out various scheduling related per-task fields: 1222 */ 1223 static int sched_show(struct seq_file *m, void *v) 1224 { 1225 struct inode *inode = m->private; 1226 struct task_struct *p; 1227 1228 p = get_proc_task(inode); 1229 if (!p) 1230 return -ESRCH; 1231 proc_sched_show_task(p, m); 1232 1233 put_task_struct(p); 1234 1235 return 0; 1236 } 1237 1238 static ssize_t 1239 sched_write(struct file *file, const char __user *buf, 1240 size_t count, loff_t *offset) 1241 { 1242 struct inode *inode = file->f_path.dentry->d_inode; 1243 struct task_struct *p; 1244 1245 p = get_proc_task(inode); 1246 if (!p) 1247 return -ESRCH; 1248 proc_sched_set_task(p); 1249 1250 put_task_struct(p); 1251 1252 return count; 1253 } 1254 1255 static int sched_open(struct inode *inode, struct file *filp) 1256 { 1257 return single_open(filp, sched_show, inode); 1258 } 1259 1260 static const struct file_operations proc_pid_sched_operations = { 1261 .open = sched_open, 1262 .read = seq_read, 1263 .write = sched_write, 1264 .llseek = seq_lseek, 1265 .release = single_release, 1266 }; 1267 1268 #endif 1269 1270 #ifdef CONFIG_SCHED_AUTOGROUP 1271 /* 1272 * Print out autogroup related information: 1273 */ 1274 static int sched_autogroup_show(struct seq_file *m, void *v) 1275 { 1276 struct inode *inode = m->private; 1277 struct task_struct *p; 1278 1279 p = get_proc_task(inode); 1280 if (!p) 1281 return -ESRCH; 1282 proc_sched_autogroup_show_task(p, m); 1283 1284 put_task_struct(p); 1285 1286 return 0; 1287 } 1288 1289 static ssize_t 1290 sched_autogroup_write(struct file *file, const char __user *buf, 1291 size_t count, loff_t *offset) 1292 { 1293 struct inode *inode = file->f_path.dentry->d_inode; 1294 struct task_struct *p; 1295 char buffer[PROC_NUMBUF]; 1296 int nice; 1297 int err; 1298 1299 memset(buffer, 0, sizeof(buffer)); 1300 if (count > sizeof(buffer) - 1) 1301 count = sizeof(buffer) - 1; 1302 if (copy_from_user(buffer, buf, count)) 1303 return -EFAULT; 1304 1305 err = kstrtoint(strstrip(buffer), 0, &nice); 1306 if (err < 0) 1307 return err; 1308 1309 p = get_proc_task(inode); 1310 if (!p) 1311 return -ESRCH; 1312 1313 err = proc_sched_autogroup_set_nice(p, nice); 1314 if (err) 1315 count = err; 1316 1317 put_task_struct(p); 1318 1319 return count; 1320 } 1321 1322 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1323 { 1324 int ret; 1325 1326 ret = single_open(filp, sched_autogroup_show, NULL); 1327 if (!ret) { 1328 struct seq_file *m = filp->private_data; 1329 1330 m->private = inode; 1331 } 1332 return ret; 1333 } 1334 1335 static const struct file_operations proc_pid_sched_autogroup_operations = { 1336 .open = sched_autogroup_open, 1337 .read = seq_read, 1338 .write = sched_autogroup_write, 1339 .llseek = seq_lseek, 1340 .release = single_release, 1341 }; 1342 1343 #endif /* CONFIG_SCHED_AUTOGROUP */ 1344 1345 static ssize_t comm_write(struct file *file, const char __user *buf, 1346 size_t count, loff_t *offset) 1347 { 1348 struct inode *inode = file->f_path.dentry->d_inode; 1349 struct task_struct *p; 1350 char buffer[TASK_COMM_LEN]; 1351 1352 memset(buffer, 0, sizeof(buffer)); 1353 if (count > sizeof(buffer) - 1) 1354 count = sizeof(buffer) - 1; 1355 if (copy_from_user(buffer, buf, count)) 1356 return -EFAULT; 1357 1358 p = get_proc_task(inode); 1359 if (!p) 1360 return -ESRCH; 1361 1362 if (same_thread_group(current, p)) 1363 set_task_comm(p, buffer); 1364 else 1365 count = -EINVAL; 1366 1367 put_task_struct(p); 1368 1369 return count; 1370 } 1371 1372 static int comm_show(struct seq_file *m, void *v) 1373 { 1374 struct inode *inode = m->private; 1375 struct task_struct *p; 1376 1377 p = get_proc_task(inode); 1378 if (!p) 1379 return -ESRCH; 1380 1381 task_lock(p); 1382 seq_printf(m, "%s\n", p->comm); 1383 task_unlock(p); 1384 1385 put_task_struct(p); 1386 1387 return 0; 1388 } 1389 1390 static int comm_open(struct inode *inode, struct file *filp) 1391 { 1392 return single_open(filp, comm_show, inode); 1393 } 1394 1395 static const struct file_operations proc_pid_set_comm_operations = { 1396 .open = comm_open, 1397 .read = seq_read, 1398 .write = comm_write, 1399 .llseek = seq_lseek, 1400 .release = single_release, 1401 }; 1402 1403 static int proc_exe_link(struct dentry *dentry, struct path *exe_path) 1404 { 1405 struct task_struct *task; 1406 struct mm_struct *mm; 1407 struct file *exe_file; 1408 1409 task = get_proc_task(dentry->d_inode); 1410 if (!task) 1411 return -ENOENT; 1412 mm = get_task_mm(task); 1413 put_task_struct(task); 1414 if (!mm) 1415 return -ENOENT; 1416 exe_file = get_mm_exe_file(mm); 1417 mmput(mm); 1418 if (exe_file) { 1419 *exe_path = exe_file->f_path; 1420 path_get(&exe_file->f_path); 1421 fput(exe_file); 1422 return 0; 1423 } else 1424 return -ENOENT; 1425 } 1426 1427 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1428 { 1429 struct inode *inode = dentry->d_inode; 1430 int error = -EACCES; 1431 1432 /* We don't need a base pointer in the /proc filesystem */ 1433 path_put(&nd->path); 1434 1435 /* Are we allowed to snoop on the tasks file descriptors? */ 1436 if (!proc_fd_access_allowed(inode)) 1437 goto out; 1438 1439 error = PROC_I(inode)->op.proc_get_link(dentry, &nd->path); 1440 out: 1441 return ERR_PTR(error); 1442 } 1443 1444 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1445 { 1446 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1447 char *pathname; 1448 int len; 1449 1450 if (!tmp) 1451 return -ENOMEM; 1452 1453 pathname = d_path(path, tmp, PAGE_SIZE); 1454 len = PTR_ERR(pathname); 1455 if (IS_ERR(pathname)) 1456 goto out; 1457 len = tmp + PAGE_SIZE - 1 - pathname; 1458 1459 if (len > buflen) 1460 len = buflen; 1461 if (copy_to_user(buffer, pathname, len)) 1462 len = -EFAULT; 1463 out: 1464 free_page((unsigned long)tmp); 1465 return len; 1466 } 1467 1468 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1469 { 1470 int error = -EACCES; 1471 struct inode *inode = dentry->d_inode; 1472 struct path path; 1473 1474 /* Are we allowed to snoop on the tasks file descriptors? */ 1475 if (!proc_fd_access_allowed(inode)) 1476 goto out; 1477 1478 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1479 if (error) 1480 goto out; 1481 1482 error = do_proc_readlink(&path, buffer, buflen); 1483 path_put(&path); 1484 out: 1485 return error; 1486 } 1487 1488 static const struct inode_operations proc_pid_link_inode_operations = { 1489 .readlink = proc_pid_readlink, 1490 .follow_link = proc_pid_follow_link, 1491 .setattr = proc_setattr, 1492 }; 1493 1494 1495 /* building an inode */ 1496 1497 static int task_dumpable(struct task_struct *task) 1498 { 1499 int dumpable = 0; 1500 struct mm_struct *mm; 1501 1502 task_lock(task); 1503 mm = task->mm; 1504 if (mm) 1505 dumpable = get_dumpable(mm); 1506 task_unlock(task); 1507 if(dumpable == 1) 1508 return 1; 1509 return 0; 1510 } 1511 1512 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1513 { 1514 struct inode * inode; 1515 struct proc_inode *ei; 1516 const struct cred *cred; 1517 1518 /* We need a new inode */ 1519 1520 inode = new_inode(sb); 1521 if (!inode) 1522 goto out; 1523 1524 /* Common stuff */ 1525 ei = PROC_I(inode); 1526 inode->i_ino = get_next_ino(); 1527 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1528 inode->i_op = &proc_def_inode_operations; 1529 1530 /* 1531 * grab the reference to task. 1532 */ 1533 ei->pid = get_task_pid(task, PIDTYPE_PID); 1534 if (!ei->pid) 1535 goto out_unlock; 1536 1537 if (task_dumpable(task)) { 1538 rcu_read_lock(); 1539 cred = __task_cred(task); 1540 inode->i_uid = cred->euid; 1541 inode->i_gid = cred->egid; 1542 rcu_read_unlock(); 1543 } 1544 security_task_to_inode(task, inode); 1545 1546 out: 1547 return inode; 1548 1549 out_unlock: 1550 iput(inode); 1551 return NULL; 1552 } 1553 1554 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1555 { 1556 struct inode *inode = dentry->d_inode; 1557 struct task_struct *task; 1558 const struct cred *cred; 1559 struct pid_namespace *pid = dentry->d_sb->s_fs_info; 1560 1561 generic_fillattr(inode, stat); 1562 1563 rcu_read_lock(); 1564 stat->uid = GLOBAL_ROOT_UID; 1565 stat->gid = GLOBAL_ROOT_GID; 1566 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1567 if (task) { 1568 if (!has_pid_permissions(pid, task, 2)) { 1569 rcu_read_unlock(); 1570 /* 1571 * This doesn't prevent learning whether PID exists, 1572 * it only makes getattr() consistent with readdir(). 1573 */ 1574 return -ENOENT; 1575 } 1576 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1577 task_dumpable(task)) { 1578 cred = __task_cred(task); 1579 stat->uid = cred->euid; 1580 stat->gid = cred->egid; 1581 } 1582 } 1583 rcu_read_unlock(); 1584 return 0; 1585 } 1586 1587 /* dentry stuff */ 1588 1589 /* 1590 * Exceptional case: normally we are not allowed to unhash a busy 1591 * directory. In this case, however, we can do it - no aliasing problems 1592 * due to the way we treat inodes. 1593 * 1594 * Rewrite the inode's ownerships here because the owning task may have 1595 * performed a setuid(), etc. 1596 * 1597 * Before the /proc/pid/status file was created the only way to read 1598 * the effective uid of a /process was to stat /proc/pid. Reading 1599 * /proc/pid/status is slow enough that procps and other packages 1600 * kept stating /proc/pid. To keep the rules in /proc simple I have 1601 * made this apply to all per process world readable and executable 1602 * directories. 1603 */ 1604 int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1605 { 1606 struct inode *inode; 1607 struct task_struct *task; 1608 const struct cred *cred; 1609 1610 if (nd && nd->flags & LOOKUP_RCU) 1611 return -ECHILD; 1612 1613 inode = dentry->d_inode; 1614 task = get_proc_task(inode); 1615 1616 if (task) { 1617 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1618 task_dumpable(task)) { 1619 rcu_read_lock(); 1620 cred = __task_cred(task); 1621 inode->i_uid = cred->euid; 1622 inode->i_gid = cred->egid; 1623 rcu_read_unlock(); 1624 } else { 1625 inode->i_uid = GLOBAL_ROOT_UID; 1626 inode->i_gid = GLOBAL_ROOT_GID; 1627 } 1628 inode->i_mode &= ~(S_ISUID | S_ISGID); 1629 security_task_to_inode(task, inode); 1630 put_task_struct(task); 1631 return 1; 1632 } 1633 d_drop(dentry); 1634 return 0; 1635 } 1636 1637 static int pid_delete_dentry(const struct dentry * dentry) 1638 { 1639 /* Is the task we represent dead? 1640 * If so, then don't put the dentry on the lru list, 1641 * kill it immediately. 1642 */ 1643 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1644 } 1645 1646 const struct dentry_operations pid_dentry_operations = 1647 { 1648 .d_revalidate = pid_revalidate, 1649 .d_delete = pid_delete_dentry, 1650 }; 1651 1652 /* Lookups */ 1653 1654 /* 1655 * Fill a directory entry. 1656 * 1657 * If possible create the dcache entry and derive our inode number and 1658 * file type from dcache entry. 1659 * 1660 * Since all of the proc inode numbers are dynamically generated, the inode 1661 * numbers do not exist until the inode is cache. This means creating the 1662 * the dcache entry in readdir is necessary to keep the inode numbers 1663 * reported by readdir in sync with the inode numbers reported 1664 * by stat. 1665 */ 1666 int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1667 const char *name, int len, 1668 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1669 { 1670 struct dentry *child, *dir = filp->f_path.dentry; 1671 struct inode *inode; 1672 struct qstr qname; 1673 ino_t ino = 0; 1674 unsigned type = DT_UNKNOWN; 1675 1676 qname.name = name; 1677 qname.len = len; 1678 qname.hash = full_name_hash(name, len); 1679 1680 child = d_lookup(dir, &qname); 1681 if (!child) { 1682 struct dentry *new; 1683 new = d_alloc(dir, &qname); 1684 if (new) { 1685 child = instantiate(dir->d_inode, new, task, ptr); 1686 if (child) 1687 dput(new); 1688 else 1689 child = new; 1690 } 1691 } 1692 if (!child || IS_ERR(child) || !child->d_inode) 1693 goto end_instantiate; 1694 inode = child->d_inode; 1695 if (inode) { 1696 ino = inode->i_ino; 1697 type = inode->i_mode >> 12; 1698 } 1699 dput(child); 1700 end_instantiate: 1701 if (!ino) 1702 ino = find_inode_number(dir, &qname); 1703 if (!ino) 1704 ino = 1; 1705 return filldir(dirent, name, len, filp->f_pos, ino, type); 1706 } 1707 1708 static unsigned name_to_int(struct dentry *dentry) 1709 { 1710 const char *name = dentry->d_name.name; 1711 int len = dentry->d_name.len; 1712 unsigned n = 0; 1713 1714 if (len > 1 && *name == '0') 1715 goto out; 1716 while (len-- > 0) { 1717 unsigned c = *name++ - '0'; 1718 if (c > 9) 1719 goto out; 1720 if (n >= (~0U-9)/10) 1721 goto out; 1722 n *= 10; 1723 n += c; 1724 } 1725 return n; 1726 out: 1727 return ~0U; 1728 } 1729 1730 #define PROC_FDINFO_MAX 64 1731 1732 static int proc_fd_info(struct inode *inode, struct path *path, char *info) 1733 { 1734 struct task_struct *task = get_proc_task(inode); 1735 struct files_struct *files = NULL; 1736 struct file *file; 1737 int fd = proc_fd(inode); 1738 1739 if (task) { 1740 files = get_files_struct(task); 1741 put_task_struct(task); 1742 } 1743 if (files) { 1744 /* 1745 * We are not taking a ref to the file structure, so we must 1746 * hold ->file_lock. 1747 */ 1748 spin_lock(&files->file_lock); 1749 file = fcheck_files(files, fd); 1750 if (file) { 1751 unsigned int f_flags; 1752 struct fdtable *fdt; 1753 1754 fdt = files_fdtable(files); 1755 f_flags = file->f_flags & ~O_CLOEXEC; 1756 if (close_on_exec(fd, fdt)) 1757 f_flags |= O_CLOEXEC; 1758 1759 if (path) { 1760 *path = file->f_path; 1761 path_get(&file->f_path); 1762 } 1763 if (info) 1764 snprintf(info, PROC_FDINFO_MAX, 1765 "pos:\t%lli\n" 1766 "flags:\t0%o\n", 1767 (long long) file->f_pos, 1768 f_flags); 1769 spin_unlock(&files->file_lock); 1770 put_files_struct(files); 1771 return 0; 1772 } 1773 spin_unlock(&files->file_lock); 1774 put_files_struct(files); 1775 } 1776 return -ENOENT; 1777 } 1778 1779 static int proc_fd_link(struct dentry *dentry, struct path *path) 1780 { 1781 return proc_fd_info(dentry->d_inode, path, NULL); 1782 } 1783 1784 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1785 { 1786 struct inode *inode; 1787 struct task_struct *task; 1788 int fd; 1789 struct files_struct *files; 1790 const struct cred *cred; 1791 1792 if (nd && nd->flags & LOOKUP_RCU) 1793 return -ECHILD; 1794 1795 inode = dentry->d_inode; 1796 task = get_proc_task(inode); 1797 fd = proc_fd(inode); 1798 1799 if (task) { 1800 files = get_files_struct(task); 1801 if (files) { 1802 struct file *file; 1803 rcu_read_lock(); 1804 file = fcheck_files(files, fd); 1805 if (file) { 1806 unsigned f_mode = file->f_mode; 1807 1808 rcu_read_unlock(); 1809 put_files_struct(files); 1810 1811 if (task_dumpable(task)) { 1812 rcu_read_lock(); 1813 cred = __task_cred(task); 1814 inode->i_uid = cred->euid; 1815 inode->i_gid = cred->egid; 1816 rcu_read_unlock(); 1817 } else { 1818 inode->i_uid = GLOBAL_ROOT_UID; 1819 inode->i_gid = GLOBAL_ROOT_GID; 1820 } 1821 1822 if (S_ISLNK(inode->i_mode)) { 1823 unsigned i_mode = S_IFLNK; 1824 if (f_mode & FMODE_READ) 1825 i_mode |= S_IRUSR | S_IXUSR; 1826 if (f_mode & FMODE_WRITE) 1827 i_mode |= S_IWUSR | S_IXUSR; 1828 inode->i_mode = i_mode; 1829 } 1830 1831 security_task_to_inode(task, inode); 1832 put_task_struct(task); 1833 return 1; 1834 } 1835 rcu_read_unlock(); 1836 put_files_struct(files); 1837 } 1838 put_task_struct(task); 1839 } 1840 d_drop(dentry); 1841 return 0; 1842 } 1843 1844 static const struct dentry_operations tid_fd_dentry_operations = 1845 { 1846 .d_revalidate = tid_fd_revalidate, 1847 .d_delete = pid_delete_dentry, 1848 }; 1849 1850 static struct dentry *proc_fd_instantiate(struct inode *dir, 1851 struct dentry *dentry, struct task_struct *task, const void *ptr) 1852 { 1853 unsigned fd = (unsigned long)ptr; 1854 struct inode *inode; 1855 struct proc_inode *ei; 1856 struct dentry *error = ERR_PTR(-ENOENT); 1857 1858 inode = proc_pid_make_inode(dir->i_sb, task); 1859 if (!inode) 1860 goto out; 1861 ei = PROC_I(inode); 1862 ei->fd = fd; 1863 1864 inode->i_mode = S_IFLNK; 1865 inode->i_op = &proc_pid_link_inode_operations; 1866 inode->i_size = 64; 1867 ei->op.proc_get_link = proc_fd_link; 1868 d_set_d_op(dentry, &tid_fd_dentry_operations); 1869 d_add(dentry, inode); 1870 /* Close the race of the process dying before we return the dentry */ 1871 if (tid_fd_revalidate(dentry, NULL)) 1872 error = NULL; 1873 1874 out: 1875 return error; 1876 } 1877 1878 static struct dentry *proc_lookupfd_common(struct inode *dir, 1879 struct dentry *dentry, 1880 instantiate_t instantiate) 1881 { 1882 struct task_struct *task = get_proc_task(dir); 1883 unsigned fd = name_to_int(dentry); 1884 struct dentry *result = ERR_PTR(-ENOENT); 1885 1886 if (!task) 1887 goto out_no_task; 1888 if (fd == ~0U) 1889 goto out; 1890 1891 result = instantiate(dir, dentry, task, (void *)(unsigned long)fd); 1892 out: 1893 put_task_struct(task); 1894 out_no_task: 1895 return result; 1896 } 1897 1898 static int proc_readfd_common(struct file * filp, void * dirent, 1899 filldir_t filldir, instantiate_t instantiate) 1900 { 1901 struct dentry *dentry = filp->f_path.dentry; 1902 struct inode *inode = dentry->d_inode; 1903 struct task_struct *p = get_proc_task(inode); 1904 unsigned int fd, ino; 1905 int retval; 1906 struct files_struct * files; 1907 1908 retval = -ENOENT; 1909 if (!p) 1910 goto out_no_task; 1911 retval = 0; 1912 1913 fd = filp->f_pos; 1914 switch (fd) { 1915 case 0: 1916 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 1917 goto out; 1918 filp->f_pos++; 1919 case 1: 1920 ino = parent_ino(dentry); 1921 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 1922 goto out; 1923 filp->f_pos++; 1924 default: 1925 files = get_files_struct(p); 1926 if (!files) 1927 goto out; 1928 rcu_read_lock(); 1929 for (fd = filp->f_pos-2; 1930 fd < files_fdtable(files)->max_fds; 1931 fd++, filp->f_pos++) { 1932 char name[PROC_NUMBUF]; 1933 int len; 1934 int rv; 1935 1936 if (!fcheck_files(files, fd)) 1937 continue; 1938 rcu_read_unlock(); 1939 1940 len = snprintf(name, sizeof(name), "%d", fd); 1941 rv = proc_fill_cache(filp, dirent, filldir, 1942 name, len, instantiate, p, 1943 (void *)(unsigned long)fd); 1944 if (rv < 0) 1945 goto out_fd_loop; 1946 rcu_read_lock(); 1947 } 1948 rcu_read_unlock(); 1949 out_fd_loop: 1950 put_files_struct(files); 1951 } 1952 out: 1953 put_task_struct(p); 1954 out_no_task: 1955 return retval; 1956 } 1957 1958 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 1959 struct nameidata *nd) 1960 { 1961 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 1962 } 1963 1964 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 1965 { 1966 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 1967 } 1968 1969 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 1970 size_t len, loff_t *ppos) 1971 { 1972 char tmp[PROC_FDINFO_MAX]; 1973 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); 1974 if (!err) 1975 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 1976 return err; 1977 } 1978 1979 static const struct file_operations proc_fdinfo_file_operations = { 1980 .open = nonseekable_open, 1981 .read = proc_fdinfo_read, 1982 .llseek = no_llseek, 1983 }; 1984 1985 static const struct file_operations proc_fd_operations = { 1986 .read = generic_read_dir, 1987 .readdir = proc_readfd, 1988 .llseek = default_llseek, 1989 }; 1990 1991 #ifdef CONFIG_CHECKPOINT_RESTORE 1992 1993 /* 1994 * dname_to_vma_addr - maps a dentry name into two unsigned longs 1995 * which represent vma start and end addresses. 1996 */ 1997 static int dname_to_vma_addr(struct dentry *dentry, 1998 unsigned long *start, unsigned long *end) 1999 { 2000 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2) 2001 return -EINVAL; 2002 2003 return 0; 2004 } 2005 2006 static int map_files_d_revalidate(struct dentry *dentry, struct nameidata *nd) 2007 { 2008 unsigned long vm_start, vm_end; 2009 bool exact_vma_exists = false; 2010 struct mm_struct *mm = NULL; 2011 struct task_struct *task; 2012 const struct cred *cred; 2013 struct inode *inode; 2014 int status = 0; 2015 2016 if (nd && nd->flags & LOOKUP_RCU) 2017 return -ECHILD; 2018 2019 if (!capable(CAP_SYS_ADMIN)) { 2020 status = -EACCES; 2021 goto out_notask; 2022 } 2023 2024 inode = dentry->d_inode; 2025 task = get_proc_task(inode); 2026 if (!task) 2027 goto out_notask; 2028 2029 mm = mm_access(task, PTRACE_MODE_READ); 2030 if (IS_ERR_OR_NULL(mm)) 2031 goto out; 2032 2033 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 2034 down_read(&mm->mmap_sem); 2035 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end); 2036 up_read(&mm->mmap_sem); 2037 } 2038 2039 mmput(mm); 2040 2041 if (exact_vma_exists) { 2042 if (task_dumpable(task)) { 2043 rcu_read_lock(); 2044 cred = __task_cred(task); 2045 inode->i_uid = cred->euid; 2046 inode->i_gid = cred->egid; 2047 rcu_read_unlock(); 2048 } else { 2049 inode->i_uid = GLOBAL_ROOT_UID; 2050 inode->i_gid = GLOBAL_ROOT_GID; 2051 } 2052 security_task_to_inode(task, inode); 2053 status = 1; 2054 } 2055 2056 out: 2057 put_task_struct(task); 2058 2059 out_notask: 2060 if (status <= 0) 2061 d_drop(dentry); 2062 2063 return status; 2064 } 2065 2066 static const struct dentry_operations tid_map_files_dentry_operations = { 2067 .d_revalidate = map_files_d_revalidate, 2068 .d_delete = pid_delete_dentry, 2069 }; 2070 2071 static int proc_map_files_get_link(struct dentry *dentry, struct path *path) 2072 { 2073 unsigned long vm_start, vm_end; 2074 struct vm_area_struct *vma; 2075 struct task_struct *task; 2076 struct mm_struct *mm; 2077 int rc; 2078 2079 rc = -ENOENT; 2080 task = get_proc_task(dentry->d_inode); 2081 if (!task) 2082 goto out; 2083 2084 mm = get_task_mm(task); 2085 put_task_struct(task); 2086 if (!mm) 2087 goto out; 2088 2089 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 2090 if (rc) 2091 goto out_mmput; 2092 2093 down_read(&mm->mmap_sem); 2094 vma = find_exact_vma(mm, vm_start, vm_end); 2095 if (vma && vma->vm_file) { 2096 *path = vma->vm_file->f_path; 2097 path_get(path); 2098 rc = 0; 2099 } 2100 up_read(&mm->mmap_sem); 2101 2102 out_mmput: 2103 mmput(mm); 2104 out: 2105 return rc; 2106 } 2107 2108 struct map_files_info { 2109 struct file *file; 2110 unsigned long len; 2111 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */ 2112 }; 2113 2114 static struct dentry * 2115 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry, 2116 struct task_struct *task, const void *ptr) 2117 { 2118 const struct file *file = ptr; 2119 struct proc_inode *ei; 2120 struct inode *inode; 2121 2122 if (!file) 2123 return ERR_PTR(-ENOENT); 2124 2125 inode = proc_pid_make_inode(dir->i_sb, task); 2126 if (!inode) 2127 return ERR_PTR(-ENOENT); 2128 2129 ei = PROC_I(inode); 2130 ei->op.proc_get_link = proc_map_files_get_link; 2131 2132 inode->i_op = &proc_pid_link_inode_operations; 2133 inode->i_size = 64; 2134 inode->i_mode = S_IFLNK; 2135 2136 if (file->f_mode & FMODE_READ) 2137 inode->i_mode |= S_IRUSR; 2138 if (file->f_mode & FMODE_WRITE) 2139 inode->i_mode |= S_IWUSR; 2140 2141 d_set_d_op(dentry, &tid_map_files_dentry_operations); 2142 d_add(dentry, inode); 2143 2144 return NULL; 2145 } 2146 2147 static struct dentry *proc_map_files_lookup(struct inode *dir, 2148 struct dentry *dentry, struct nameidata *nd) 2149 { 2150 unsigned long vm_start, vm_end; 2151 struct vm_area_struct *vma; 2152 struct task_struct *task; 2153 struct dentry *result; 2154 struct mm_struct *mm; 2155 2156 result = ERR_PTR(-EACCES); 2157 if (!capable(CAP_SYS_ADMIN)) 2158 goto out; 2159 2160 result = ERR_PTR(-ENOENT); 2161 task = get_proc_task(dir); 2162 if (!task) 2163 goto out; 2164 2165 result = ERR_PTR(-EACCES); 2166 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 2167 goto out_put_task; 2168 2169 result = ERR_PTR(-ENOENT); 2170 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 2171 goto out_put_task; 2172 2173 mm = get_task_mm(task); 2174 if (!mm) 2175 goto out_put_task; 2176 2177 down_read(&mm->mmap_sem); 2178 vma = find_exact_vma(mm, vm_start, vm_end); 2179 if (!vma) 2180 goto out_no_vma; 2181 2182 result = proc_map_files_instantiate(dir, dentry, task, vma->vm_file); 2183 2184 out_no_vma: 2185 up_read(&mm->mmap_sem); 2186 mmput(mm); 2187 out_put_task: 2188 put_task_struct(task); 2189 out: 2190 return result; 2191 } 2192 2193 static const struct inode_operations proc_map_files_inode_operations = { 2194 .lookup = proc_map_files_lookup, 2195 .permission = proc_fd_permission, 2196 .setattr = proc_setattr, 2197 }; 2198 2199 static int 2200 proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir) 2201 { 2202 struct dentry *dentry = filp->f_path.dentry; 2203 struct inode *inode = dentry->d_inode; 2204 struct vm_area_struct *vma; 2205 struct task_struct *task; 2206 struct mm_struct *mm; 2207 ino_t ino; 2208 int ret; 2209 2210 ret = -EACCES; 2211 if (!capable(CAP_SYS_ADMIN)) 2212 goto out; 2213 2214 ret = -ENOENT; 2215 task = get_proc_task(inode); 2216 if (!task) 2217 goto out; 2218 2219 ret = -EACCES; 2220 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 2221 goto out_put_task; 2222 2223 ret = 0; 2224 switch (filp->f_pos) { 2225 case 0: 2226 ino = inode->i_ino; 2227 if (filldir(dirent, ".", 1, 0, ino, DT_DIR) < 0) 2228 goto out_put_task; 2229 filp->f_pos++; 2230 case 1: 2231 ino = parent_ino(dentry); 2232 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 2233 goto out_put_task; 2234 filp->f_pos++; 2235 default: 2236 { 2237 unsigned long nr_files, pos, i; 2238 struct flex_array *fa = NULL; 2239 struct map_files_info info; 2240 struct map_files_info *p; 2241 2242 mm = get_task_mm(task); 2243 if (!mm) 2244 goto out_put_task; 2245 down_read(&mm->mmap_sem); 2246 2247 nr_files = 0; 2248 2249 /* 2250 * We need two passes here: 2251 * 2252 * 1) Collect vmas of mapped files with mmap_sem taken 2253 * 2) Release mmap_sem and instantiate entries 2254 * 2255 * otherwise we get lockdep complained, since filldir() 2256 * routine might require mmap_sem taken in might_fault(). 2257 */ 2258 2259 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 2260 if (vma->vm_file && ++pos > filp->f_pos) 2261 nr_files++; 2262 } 2263 2264 if (nr_files) { 2265 fa = flex_array_alloc(sizeof(info), nr_files, 2266 GFP_KERNEL); 2267 if (!fa || flex_array_prealloc(fa, 0, nr_files, 2268 GFP_KERNEL)) { 2269 ret = -ENOMEM; 2270 if (fa) 2271 flex_array_free(fa); 2272 up_read(&mm->mmap_sem); 2273 mmput(mm); 2274 goto out_put_task; 2275 } 2276 for (i = 0, vma = mm->mmap, pos = 2; vma; 2277 vma = vma->vm_next) { 2278 if (!vma->vm_file) 2279 continue; 2280 if (++pos <= filp->f_pos) 2281 continue; 2282 2283 get_file(vma->vm_file); 2284 info.file = vma->vm_file; 2285 info.len = snprintf(info.name, 2286 sizeof(info.name), "%lx-%lx", 2287 vma->vm_start, vma->vm_end); 2288 if (flex_array_put(fa, i++, &info, GFP_KERNEL)) 2289 BUG(); 2290 } 2291 } 2292 up_read(&mm->mmap_sem); 2293 2294 for (i = 0; i < nr_files; i++) { 2295 p = flex_array_get(fa, i); 2296 ret = proc_fill_cache(filp, dirent, filldir, 2297 p->name, p->len, 2298 proc_map_files_instantiate, 2299 task, p->file); 2300 if (ret) 2301 break; 2302 filp->f_pos++; 2303 fput(p->file); 2304 } 2305 for (; i < nr_files; i++) { 2306 /* 2307 * In case of error don't forget 2308 * to put rest of file refs. 2309 */ 2310 p = flex_array_get(fa, i); 2311 fput(p->file); 2312 } 2313 if (fa) 2314 flex_array_free(fa); 2315 mmput(mm); 2316 } 2317 } 2318 2319 out_put_task: 2320 put_task_struct(task); 2321 out: 2322 return ret; 2323 } 2324 2325 static const struct file_operations proc_map_files_operations = { 2326 .read = generic_read_dir, 2327 .readdir = proc_map_files_readdir, 2328 .llseek = default_llseek, 2329 }; 2330 2331 #endif /* CONFIG_CHECKPOINT_RESTORE */ 2332 2333 /* 2334 * /proc/pid/fd needs a special permission handler so that a process can still 2335 * access /proc/self/fd after it has executed a setuid(). 2336 */ 2337 static int proc_fd_permission(struct inode *inode, int mask) 2338 { 2339 int rv = generic_permission(inode, mask); 2340 if (rv == 0) 2341 return 0; 2342 if (task_pid(current) == proc_pid(inode)) 2343 rv = 0; 2344 return rv; 2345 } 2346 2347 /* 2348 * proc directories can do almost nothing.. 2349 */ 2350 static const struct inode_operations proc_fd_inode_operations = { 2351 .lookup = proc_lookupfd, 2352 .permission = proc_fd_permission, 2353 .setattr = proc_setattr, 2354 }; 2355 2356 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 2357 struct dentry *dentry, struct task_struct *task, const void *ptr) 2358 { 2359 unsigned fd = (unsigned long)ptr; 2360 struct inode *inode; 2361 struct proc_inode *ei; 2362 struct dentry *error = ERR_PTR(-ENOENT); 2363 2364 inode = proc_pid_make_inode(dir->i_sb, task); 2365 if (!inode) 2366 goto out; 2367 ei = PROC_I(inode); 2368 ei->fd = fd; 2369 inode->i_mode = S_IFREG | S_IRUSR; 2370 inode->i_fop = &proc_fdinfo_file_operations; 2371 d_set_d_op(dentry, &tid_fd_dentry_operations); 2372 d_add(dentry, inode); 2373 /* Close the race of the process dying before we return the dentry */ 2374 if (tid_fd_revalidate(dentry, NULL)) 2375 error = NULL; 2376 2377 out: 2378 return error; 2379 } 2380 2381 static struct dentry *proc_lookupfdinfo(struct inode *dir, 2382 struct dentry *dentry, 2383 struct nameidata *nd) 2384 { 2385 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 2386 } 2387 2388 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 2389 { 2390 return proc_readfd_common(filp, dirent, filldir, 2391 proc_fdinfo_instantiate); 2392 } 2393 2394 static const struct file_operations proc_fdinfo_operations = { 2395 .read = generic_read_dir, 2396 .readdir = proc_readfdinfo, 2397 .llseek = default_llseek, 2398 }; 2399 2400 /* 2401 * proc directories can do almost nothing.. 2402 */ 2403 static const struct inode_operations proc_fdinfo_inode_operations = { 2404 .lookup = proc_lookupfdinfo, 2405 .setattr = proc_setattr, 2406 }; 2407 2408 2409 static struct dentry *proc_pident_instantiate(struct inode *dir, 2410 struct dentry *dentry, struct task_struct *task, const void *ptr) 2411 { 2412 const struct pid_entry *p = ptr; 2413 struct inode *inode; 2414 struct proc_inode *ei; 2415 struct dentry *error = ERR_PTR(-ENOENT); 2416 2417 inode = proc_pid_make_inode(dir->i_sb, task); 2418 if (!inode) 2419 goto out; 2420 2421 ei = PROC_I(inode); 2422 inode->i_mode = p->mode; 2423 if (S_ISDIR(inode->i_mode)) 2424 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2425 if (p->iop) 2426 inode->i_op = p->iop; 2427 if (p->fop) 2428 inode->i_fop = p->fop; 2429 ei->op = p->op; 2430 d_set_d_op(dentry, &pid_dentry_operations); 2431 d_add(dentry, inode); 2432 /* Close the race of the process dying before we return the dentry */ 2433 if (pid_revalidate(dentry, NULL)) 2434 error = NULL; 2435 out: 2436 return error; 2437 } 2438 2439 static struct dentry *proc_pident_lookup(struct inode *dir, 2440 struct dentry *dentry, 2441 const struct pid_entry *ents, 2442 unsigned int nents) 2443 { 2444 struct dentry *error; 2445 struct task_struct *task = get_proc_task(dir); 2446 const struct pid_entry *p, *last; 2447 2448 error = ERR_PTR(-ENOENT); 2449 2450 if (!task) 2451 goto out_no_task; 2452 2453 /* 2454 * Yes, it does not scale. And it should not. Don't add 2455 * new entries into /proc/<tgid>/ without very good reasons. 2456 */ 2457 last = &ents[nents - 1]; 2458 for (p = ents; p <= last; p++) { 2459 if (p->len != dentry->d_name.len) 2460 continue; 2461 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2462 break; 2463 } 2464 if (p > last) 2465 goto out; 2466 2467 error = proc_pident_instantiate(dir, dentry, task, p); 2468 out: 2469 put_task_struct(task); 2470 out_no_task: 2471 return error; 2472 } 2473 2474 static int proc_pident_fill_cache(struct file *filp, void *dirent, 2475 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2476 { 2477 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2478 proc_pident_instantiate, task, p); 2479 } 2480 2481 static int proc_pident_readdir(struct file *filp, 2482 void *dirent, filldir_t filldir, 2483 const struct pid_entry *ents, unsigned int nents) 2484 { 2485 int i; 2486 struct dentry *dentry = filp->f_path.dentry; 2487 struct inode *inode = dentry->d_inode; 2488 struct task_struct *task = get_proc_task(inode); 2489 const struct pid_entry *p, *last; 2490 ino_t ino; 2491 int ret; 2492 2493 ret = -ENOENT; 2494 if (!task) 2495 goto out_no_task; 2496 2497 ret = 0; 2498 i = filp->f_pos; 2499 switch (i) { 2500 case 0: 2501 ino = inode->i_ino; 2502 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 2503 goto out; 2504 i++; 2505 filp->f_pos++; 2506 /* fall through */ 2507 case 1: 2508 ino = parent_ino(dentry); 2509 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 2510 goto out; 2511 i++; 2512 filp->f_pos++; 2513 /* fall through */ 2514 default: 2515 i -= 2; 2516 if (i >= nents) { 2517 ret = 1; 2518 goto out; 2519 } 2520 p = ents + i; 2521 last = &ents[nents - 1]; 2522 while (p <= last) { 2523 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2524 goto out; 2525 filp->f_pos++; 2526 p++; 2527 } 2528 } 2529 2530 ret = 1; 2531 out: 2532 put_task_struct(task); 2533 out_no_task: 2534 return ret; 2535 } 2536 2537 #ifdef CONFIG_SECURITY 2538 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2539 size_t count, loff_t *ppos) 2540 { 2541 struct inode * inode = file->f_path.dentry->d_inode; 2542 char *p = NULL; 2543 ssize_t length; 2544 struct task_struct *task = get_proc_task(inode); 2545 2546 if (!task) 2547 return -ESRCH; 2548 2549 length = security_getprocattr(task, 2550 (char*)file->f_path.dentry->d_name.name, 2551 &p); 2552 put_task_struct(task); 2553 if (length > 0) 2554 length = simple_read_from_buffer(buf, count, ppos, p, length); 2555 kfree(p); 2556 return length; 2557 } 2558 2559 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2560 size_t count, loff_t *ppos) 2561 { 2562 struct inode * inode = file->f_path.dentry->d_inode; 2563 char *page; 2564 ssize_t length; 2565 struct task_struct *task = get_proc_task(inode); 2566 2567 length = -ESRCH; 2568 if (!task) 2569 goto out_no_task; 2570 if (count > PAGE_SIZE) 2571 count = PAGE_SIZE; 2572 2573 /* No partial writes. */ 2574 length = -EINVAL; 2575 if (*ppos != 0) 2576 goto out; 2577 2578 length = -ENOMEM; 2579 page = (char*)__get_free_page(GFP_TEMPORARY); 2580 if (!page) 2581 goto out; 2582 2583 length = -EFAULT; 2584 if (copy_from_user(page, buf, count)) 2585 goto out_free; 2586 2587 /* Guard against adverse ptrace interaction */ 2588 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex); 2589 if (length < 0) 2590 goto out_free; 2591 2592 length = security_setprocattr(task, 2593 (char*)file->f_path.dentry->d_name.name, 2594 (void*)page, count); 2595 mutex_unlock(&task->signal->cred_guard_mutex); 2596 out_free: 2597 free_page((unsigned long) page); 2598 out: 2599 put_task_struct(task); 2600 out_no_task: 2601 return length; 2602 } 2603 2604 static const struct file_operations proc_pid_attr_operations = { 2605 .read = proc_pid_attr_read, 2606 .write = proc_pid_attr_write, 2607 .llseek = generic_file_llseek, 2608 }; 2609 2610 static const struct pid_entry attr_dir_stuff[] = { 2611 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2612 REG("prev", S_IRUGO, proc_pid_attr_operations), 2613 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2614 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2615 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2616 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2617 }; 2618 2619 static int proc_attr_dir_readdir(struct file * filp, 2620 void * dirent, filldir_t filldir) 2621 { 2622 return proc_pident_readdir(filp,dirent,filldir, 2623 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2624 } 2625 2626 static const struct file_operations proc_attr_dir_operations = { 2627 .read = generic_read_dir, 2628 .readdir = proc_attr_dir_readdir, 2629 .llseek = default_llseek, 2630 }; 2631 2632 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2633 struct dentry *dentry, struct nameidata *nd) 2634 { 2635 return proc_pident_lookup(dir, dentry, 2636 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2637 } 2638 2639 static const struct inode_operations proc_attr_dir_inode_operations = { 2640 .lookup = proc_attr_dir_lookup, 2641 .getattr = pid_getattr, 2642 .setattr = proc_setattr, 2643 }; 2644 2645 #endif 2646 2647 #ifdef CONFIG_ELF_CORE 2648 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2649 size_t count, loff_t *ppos) 2650 { 2651 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2652 struct mm_struct *mm; 2653 char buffer[PROC_NUMBUF]; 2654 size_t len; 2655 int ret; 2656 2657 if (!task) 2658 return -ESRCH; 2659 2660 ret = 0; 2661 mm = get_task_mm(task); 2662 if (mm) { 2663 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2664 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2665 MMF_DUMP_FILTER_SHIFT)); 2666 mmput(mm); 2667 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2668 } 2669 2670 put_task_struct(task); 2671 2672 return ret; 2673 } 2674 2675 static ssize_t proc_coredump_filter_write(struct file *file, 2676 const char __user *buf, 2677 size_t count, 2678 loff_t *ppos) 2679 { 2680 struct task_struct *task; 2681 struct mm_struct *mm; 2682 char buffer[PROC_NUMBUF], *end; 2683 unsigned int val; 2684 int ret; 2685 int i; 2686 unsigned long mask; 2687 2688 ret = -EFAULT; 2689 memset(buffer, 0, sizeof(buffer)); 2690 if (count > sizeof(buffer) - 1) 2691 count = sizeof(buffer) - 1; 2692 if (copy_from_user(buffer, buf, count)) 2693 goto out_no_task; 2694 2695 ret = -EINVAL; 2696 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2697 if (*end == '\n') 2698 end++; 2699 if (end - buffer == 0) 2700 goto out_no_task; 2701 2702 ret = -ESRCH; 2703 task = get_proc_task(file->f_dentry->d_inode); 2704 if (!task) 2705 goto out_no_task; 2706 2707 ret = end - buffer; 2708 mm = get_task_mm(task); 2709 if (!mm) 2710 goto out_no_mm; 2711 2712 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2713 if (val & mask) 2714 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2715 else 2716 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2717 } 2718 2719 mmput(mm); 2720 out_no_mm: 2721 put_task_struct(task); 2722 out_no_task: 2723 return ret; 2724 } 2725 2726 static const struct file_operations proc_coredump_filter_operations = { 2727 .read = proc_coredump_filter_read, 2728 .write = proc_coredump_filter_write, 2729 .llseek = generic_file_llseek, 2730 }; 2731 #endif 2732 2733 /* 2734 * /proc/self: 2735 */ 2736 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2737 int buflen) 2738 { 2739 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2740 pid_t tgid = task_tgid_nr_ns(current, ns); 2741 char tmp[PROC_NUMBUF]; 2742 if (!tgid) 2743 return -ENOENT; 2744 sprintf(tmp, "%d", tgid); 2745 return vfs_readlink(dentry,buffer,buflen,tmp); 2746 } 2747 2748 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2749 { 2750 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2751 pid_t tgid = task_tgid_nr_ns(current, ns); 2752 char *name = ERR_PTR(-ENOENT); 2753 if (tgid) { 2754 name = __getname(); 2755 if (!name) 2756 name = ERR_PTR(-ENOMEM); 2757 else 2758 sprintf(name, "%d", tgid); 2759 } 2760 nd_set_link(nd, name); 2761 return NULL; 2762 } 2763 2764 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd, 2765 void *cookie) 2766 { 2767 char *s = nd_get_link(nd); 2768 if (!IS_ERR(s)) 2769 __putname(s); 2770 } 2771 2772 static const struct inode_operations proc_self_inode_operations = { 2773 .readlink = proc_self_readlink, 2774 .follow_link = proc_self_follow_link, 2775 .put_link = proc_self_put_link, 2776 }; 2777 2778 /* 2779 * proc base 2780 * 2781 * These are the directory entries in the root directory of /proc 2782 * that properly belong to the /proc filesystem, as they describe 2783 * describe something that is process related. 2784 */ 2785 static const struct pid_entry proc_base_stuff[] = { 2786 NOD("self", S_IFLNK|S_IRWXUGO, 2787 &proc_self_inode_operations, NULL, {}), 2788 }; 2789 2790 static struct dentry *proc_base_instantiate(struct inode *dir, 2791 struct dentry *dentry, struct task_struct *task, const void *ptr) 2792 { 2793 const struct pid_entry *p = ptr; 2794 struct inode *inode; 2795 struct proc_inode *ei; 2796 struct dentry *error; 2797 2798 /* Allocate the inode */ 2799 error = ERR_PTR(-ENOMEM); 2800 inode = new_inode(dir->i_sb); 2801 if (!inode) 2802 goto out; 2803 2804 /* Initialize the inode */ 2805 ei = PROC_I(inode); 2806 inode->i_ino = get_next_ino(); 2807 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2808 2809 /* 2810 * grab the reference to the task. 2811 */ 2812 ei->pid = get_task_pid(task, PIDTYPE_PID); 2813 if (!ei->pid) 2814 goto out_iput; 2815 2816 inode->i_mode = p->mode; 2817 if (S_ISDIR(inode->i_mode)) 2818 set_nlink(inode, 2); 2819 if (S_ISLNK(inode->i_mode)) 2820 inode->i_size = 64; 2821 if (p->iop) 2822 inode->i_op = p->iop; 2823 if (p->fop) 2824 inode->i_fop = p->fop; 2825 ei->op = p->op; 2826 d_add(dentry, inode); 2827 error = NULL; 2828 out: 2829 return error; 2830 out_iput: 2831 iput(inode); 2832 goto out; 2833 } 2834 2835 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2836 { 2837 struct dentry *error; 2838 struct task_struct *task = get_proc_task(dir); 2839 const struct pid_entry *p, *last; 2840 2841 error = ERR_PTR(-ENOENT); 2842 2843 if (!task) 2844 goto out_no_task; 2845 2846 /* Lookup the directory entry */ 2847 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2848 for (p = proc_base_stuff; p <= last; p++) { 2849 if (p->len != dentry->d_name.len) 2850 continue; 2851 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2852 break; 2853 } 2854 if (p > last) 2855 goto out; 2856 2857 error = proc_base_instantiate(dir, dentry, task, p); 2858 2859 out: 2860 put_task_struct(task); 2861 out_no_task: 2862 return error; 2863 } 2864 2865 static int proc_base_fill_cache(struct file *filp, void *dirent, 2866 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2867 { 2868 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2869 proc_base_instantiate, task, p); 2870 } 2871 2872 #ifdef CONFIG_TASK_IO_ACCOUNTING 2873 static int do_io_accounting(struct task_struct *task, char *buffer, int whole) 2874 { 2875 struct task_io_accounting acct = task->ioac; 2876 unsigned long flags; 2877 int result; 2878 2879 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2880 if (result) 2881 return result; 2882 2883 if (!ptrace_may_access(task, PTRACE_MODE_READ)) { 2884 result = -EACCES; 2885 goto out_unlock; 2886 } 2887 2888 if (whole && lock_task_sighand(task, &flags)) { 2889 struct task_struct *t = task; 2890 2891 task_io_accounting_add(&acct, &task->signal->ioac); 2892 while_each_thread(task, t) 2893 task_io_accounting_add(&acct, &t->ioac); 2894 2895 unlock_task_sighand(task, &flags); 2896 } 2897 result = sprintf(buffer, 2898 "rchar: %llu\n" 2899 "wchar: %llu\n" 2900 "syscr: %llu\n" 2901 "syscw: %llu\n" 2902 "read_bytes: %llu\n" 2903 "write_bytes: %llu\n" 2904 "cancelled_write_bytes: %llu\n", 2905 (unsigned long long)acct.rchar, 2906 (unsigned long long)acct.wchar, 2907 (unsigned long long)acct.syscr, 2908 (unsigned long long)acct.syscw, 2909 (unsigned long long)acct.read_bytes, 2910 (unsigned long long)acct.write_bytes, 2911 (unsigned long long)acct.cancelled_write_bytes); 2912 out_unlock: 2913 mutex_unlock(&task->signal->cred_guard_mutex); 2914 return result; 2915 } 2916 2917 static int proc_tid_io_accounting(struct task_struct *task, char *buffer) 2918 { 2919 return do_io_accounting(task, buffer, 0); 2920 } 2921 2922 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer) 2923 { 2924 return do_io_accounting(task, buffer, 1); 2925 } 2926 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2927 2928 #ifdef CONFIG_USER_NS 2929 static int proc_id_map_open(struct inode *inode, struct file *file, 2930 struct seq_operations *seq_ops) 2931 { 2932 struct user_namespace *ns = NULL; 2933 struct task_struct *task; 2934 struct seq_file *seq; 2935 int ret = -EINVAL; 2936 2937 task = get_proc_task(inode); 2938 if (task) { 2939 rcu_read_lock(); 2940 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2941 rcu_read_unlock(); 2942 put_task_struct(task); 2943 } 2944 if (!ns) 2945 goto err; 2946 2947 ret = seq_open(file, seq_ops); 2948 if (ret) 2949 goto err_put_ns; 2950 2951 seq = file->private_data; 2952 seq->private = ns; 2953 2954 return 0; 2955 err_put_ns: 2956 put_user_ns(ns); 2957 err: 2958 return ret; 2959 } 2960 2961 static int proc_id_map_release(struct inode *inode, struct file *file) 2962 { 2963 struct seq_file *seq = file->private_data; 2964 struct user_namespace *ns = seq->private; 2965 put_user_ns(ns); 2966 return seq_release(inode, file); 2967 } 2968 2969 static int proc_uid_map_open(struct inode *inode, struct file *file) 2970 { 2971 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2972 } 2973 2974 static int proc_gid_map_open(struct inode *inode, struct file *file) 2975 { 2976 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2977 } 2978 2979 static const struct file_operations proc_uid_map_operations = { 2980 .open = proc_uid_map_open, 2981 .write = proc_uid_map_write, 2982 .read = seq_read, 2983 .llseek = seq_lseek, 2984 .release = proc_id_map_release, 2985 }; 2986 2987 static const struct file_operations proc_gid_map_operations = { 2988 .open = proc_gid_map_open, 2989 .write = proc_gid_map_write, 2990 .read = seq_read, 2991 .llseek = seq_lseek, 2992 .release = proc_id_map_release, 2993 }; 2994 #endif /* CONFIG_USER_NS */ 2995 2996 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2997 struct pid *pid, struct task_struct *task) 2998 { 2999 int err = lock_trace(task); 3000 if (!err) { 3001 seq_printf(m, "%08x\n", task->personality); 3002 unlock_trace(task); 3003 } 3004 return err; 3005 } 3006 3007 /* 3008 * Thread groups 3009 */ 3010 static const struct file_operations proc_task_operations; 3011 static const struct inode_operations proc_task_inode_operations; 3012 3013 static const struct pid_entry tgid_base_stuff[] = { 3014 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 3015 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3016 #ifdef CONFIG_CHECKPOINT_RESTORE 3017 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 3018 #endif 3019 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3020 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3021 #ifdef CONFIG_NET 3022 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3023 #endif 3024 REG("environ", S_IRUSR, proc_environ_operations), 3025 INF("auxv", S_IRUSR, proc_pid_auxv), 3026 ONE("status", S_IRUGO, proc_pid_status), 3027 ONE("personality", S_IRUGO, proc_pid_personality), 3028 INF("limits", S_IRUGO, proc_pid_limits), 3029 #ifdef CONFIG_SCHED_DEBUG 3030 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3031 #endif 3032 #ifdef CONFIG_SCHED_AUTOGROUP 3033 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 3034 #endif 3035 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3036 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3037 INF("syscall", S_IRUGO, proc_pid_syscall), 3038 #endif 3039 INF("cmdline", S_IRUGO, proc_pid_cmdline), 3040 ONE("stat", S_IRUGO, proc_tgid_stat), 3041 ONE("statm", S_IRUGO, proc_pid_statm), 3042 REG("maps", S_IRUGO, proc_pid_maps_operations), 3043 #ifdef CONFIG_NUMA 3044 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 3045 #endif 3046 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3047 LNK("cwd", proc_cwd_link), 3048 LNK("root", proc_root_link), 3049 LNK("exe", proc_exe_link), 3050 REG("mounts", S_IRUGO, proc_mounts_operations), 3051 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3052 REG("mountstats", S_IRUSR, proc_mountstats_operations), 3053 #ifdef CONFIG_PROC_PAGE_MONITOR 3054 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3055 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 3056 REG("pagemap", S_IRUGO, proc_pagemap_operations), 3057 #endif 3058 #ifdef CONFIG_SECURITY 3059 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3060 #endif 3061 #ifdef CONFIG_KALLSYMS 3062 INF("wchan", S_IRUGO, proc_pid_wchan), 3063 #endif 3064 #ifdef CONFIG_STACKTRACE 3065 ONE("stack", S_IRUGO, proc_pid_stack), 3066 #endif 3067 #ifdef CONFIG_SCHEDSTATS 3068 INF("schedstat", S_IRUGO, proc_pid_schedstat), 3069 #endif 3070 #ifdef CONFIG_LATENCYTOP 3071 REG("latency", S_IRUGO, proc_lstats_operations), 3072 #endif 3073 #ifdef CONFIG_PROC_PID_CPUSET 3074 REG("cpuset", S_IRUGO, proc_cpuset_operations), 3075 #endif 3076 #ifdef CONFIG_CGROUPS 3077 REG("cgroup", S_IRUGO, proc_cgroup_operations), 3078 #endif 3079 INF("oom_score", S_IRUGO, proc_oom_score), 3080 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 3081 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3082 #ifdef CONFIG_AUDITSYSCALL 3083 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3084 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3085 #endif 3086 #ifdef CONFIG_FAULT_INJECTION 3087 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3088 #endif 3089 #ifdef CONFIG_ELF_CORE 3090 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 3091 #endif 3092 #ifdef CONFIG_TASK_IO_ACCOUNTING 3093 INF("io", S_IRUSR, proc_tgid_io_accounting), 3094 #endif 3095 #ifdef CONFIG_HARDWALL 3096 INF("hardwall", S_IRUGO, proc_pid_hardwall), 3097 #endif 3098 #ifdef CONFIG_USER_NS 3099 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3100 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3101 #endif 3102 }; 3103 3104 static int proc_tgid_base_readdir(struct file * filp, 3105 void * dirent, filldir_t filldir) 3106 { 3107 return proc_pident_readdir(filp,dirent,filldir, 3108 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 3109 } 3110 3111 static const struct file_operations proc_tgid_base_operations = { 3112 .read = generic_read_dir, 3113 .readdir = proc_tgid_base_readdir, 3114 .llseek = default_llseek, 3115 }; 3116 3117 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 3118 return proc_pident_lookup(dir, dentry, 3119 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3120 } 3121 3122 static const struct inode_operations proc_tgid_base_inode_operations = { 3123 .lookup = proc_tgid_base_lookup, 3124 .getattr = pid_getattr, 3125 .setattr = proc_setattr, 3126 .permission = proc_pid_permission, 3127 }; 3128 3129 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 3130 { 3131 struct dentry *dentry, *leader, *dir; 3132 char buf[PROC_NUMBUF]; 3133 struct qstr name; 3134 3135 name.name = buf; 3136 name.len = snprintf(buf, sizeof(buf), "%d", pid); 3137 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 3138 if (dentry) { 3139 shrink_dcache_parent(dentry); 3140 d_drop(dentry); 3141 dput(dentry); 3142 } 3143 3144 name.name = buf; 3145 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 3146 leader = d_hash_and_lookup(mnt->mnt_root, &name); 3147 if (!leader) 3148 goto out; 3149 3150 name.name = "task"; 3151 name.len = strlen(name.name); 3152 dir = d_hash_and_lookup(leader, &name); 3153 if (!dir) 3154 goto out_put_leader; 3155 3156 name.name = buf; 3157 name.len = snprintf(buf, sizeof(buf), "%d", pid); 3158 dentry = d_hash_and_lookup(dir, &name); 3159 if (dentry) { 3160 shrink_dcache_parent(dentry); 3161 d_drop(dentry); 3162 dput(dentry); 3163 } 3164 3165 dput(dir); 3166 out_put_leader: 3167 dput(leader); 3168 out: 3169 return; 3170 } 3171 3172 /** 3173 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 3174 * @task: task that should be flushed. 3175 * 3176 * When flushing dentries from proc, one needs to flush them from global 3177 * proc (proc_mnt) and from all the namespaces' procs this task was seen 3178 * in. This call is supposed to do all of this job. 3179 * 3180 * Looks in the dcache for 3181 * /proc/@pid 3182 * /proc/@tgid/task/@pid 3183 * if either directory is present flushes it and all of it'ts children 3184 * from the dcache. 3185 * 3186 * It is safe and reasonable to cache /proc entries for a task until 3187 * that task exits. After that they just clog up the dcache with 3188 * useless entries, possibly causing useful dcache entries to be 3189 * flushed instead. This routine is proved to flush those useless 3190 * dcache entries at process exit time. 3191 * 3192 * NOTE: This routine is just an optimization so it does not guarantee 3193 * that no dcache entries will exist at process exit time it 3194 * just makes it very unlikely that any will persist. 3195 */ 3196 3197 void proc_flush_task(struct task_struct *task) 3198 { 3199 int i; 3200 struct pid *pid, *tgid; 3201 struct upid *upid; 3202 3203 pid = task_pid(task); 3204 tgid = task_tgid(task); 3205 3206 for (i = 0; i <= pid->level; i++) { 3207 upid = &pid->numbers[i]; 3208 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3209 tgid->numbers[i].nr); 3210 } 3211 3212 upid = &pid->numbers[pid->level]; 3213 if (upid->nr == 1) 3214 pid_ns_release_proc(upid->ns); 3215 } 3216 3217 static struct dentry *proc_pid_instantiate(struct inode *dir, 3218 struct dentry * dentry, 3219 struct task_struct *task, const void *ptr) 3220 { 3221 struct dentry *error = ERR_PTR(-ENOENT); 3222 struct inode *inode; 3223 3224 inode = proc_pid_make_inode(dir->i_sb, task); 3225 if (!inode) 3226 goto out; 3227 3228 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3229 inode->i_op = &proc_tgid_base_inode_operations; 3230 inode->i_fop = &proc_tgid_base_operations; 3231 inode->i_flags|=S_IMMUTABLE; 3232 3233 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff, 3234 ARRAY_SIZE(tgid_base_stuff))); 3235 3236 d_set_d_op(dentry, &pid_dentry_operations); 3237 3238 d_add(dentry, inode); 3239 /* Close the race of the process dying before we return the dentry */ 3240 if (pid_revalidate(dentry, NULL)) 3241 error = NULL; 3242 out: 3243 return error; 3244 } 3245 3246 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 3247 { 3248 struct dentry *result; 3249 struct task_struct *task; 3250 unsigned tgid; 3251 struct pid_namespace *ns; 3252 3253 result = proc_base_lookup(dir, dentry); 3254 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 3255 goto out; 3256 3257 tgid = name_to_int(dentry); 3258 if (tgid == ~0U) 3259 goto out; 3260 3261 ns = dentry->d_sb->s_fs_info; 3262 rcu_read_lock(); 3263 task = find_task_by_pid_ns(tgid, ns); 3264 if (task) 3265 get_task_struct(task); 3266 rcu_read_unlock(); 3267 if (!task) 3268 goto out; 3269 3270 result = proc_pid_instantiate(dir, dentry, task, NULL); 3271 put_task_struct(task); 3272 out: 3273 return result; 3274 } 3275 3276 /* 3277 * Find the first task with tgid >= tgid 3278 * 3279 */ 3280 struct tgid_iter { 3281 unsigned int tgid; 3282 struct task_struct *task; 3283 }; 3284 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3285 { 3286 struct pid *pid; 3287 3288 if (iter.task) 3289 put_task_struct(iter.task); 3290 rcu_read_lock(); 3291 retry: 3292 iter.task = NULL; 3293 pid = find_ge_pid(iter.tgid, ns); 3294 if (pid) { 3295 iter.tgid = pid_nr_ns(pid, ns); 3296 iter.task = pid_task(pid, PIDTYPE_PID); 3297 /* What we to know is if the pid we have find is the 3298 * pid of a thread_group_leader. Testing for task 3299 * being a thread_group_leader is the obvious thing 3300 * todo but there is a window when it fails, due to 3301 * the pid transfer logic in de_thread. 3302 * 3303 * So we perform the straight forward test of seeing 3304 * if the pid we have found is the pid of a thread 3305 * group leader, and don't worry if the task we have 3306 * found doesn't happen to be a thread group leader. 3307 * As we don't care in the case of readdir. 3308 */ 3309 if (!iter.task || !has_group_leader_pid(iter.task)) { 3310 iter.tgid += 1; 3311 goto retry; 3312 } 3313 get_task_struct(iter.task); 3314 } 3315 rcu_read_unlock(); 3316 return iter; 3317 } 3318 3319 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 3320 3321 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3322 struct tgid_iter iter) 3323 { 3324 char name[PROC_NUMBUF]; 3325 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 3326 return proc_fill_cache(filp, dirent, filldir, name, len, 3327 proc_pid_instantiate, iter.task, NULL); 3328 } 3329 3330 static int fake_filldir(void *buf, const char *name, int namelen, 3331 loff_t offset, u64 ino, unsigned d_type) 3332 { 3333 return 0; 3334 } 3335 3336 /* for the /proc/ directory itself, after non-process stuff has been done */ 3337 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 3338 { 3339 unsigned int nr; 3340 struct task_struct *reaper; 3341 struct tgid_iter iter; 3342 struct pid_namespace *ns; 3343 filldir_t __filldir; 3344 3345 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET) 3346 goto out_no_task; 3347 nr = filp->f_pos - FIRST_PROCESS_ENTRY; 3348 3349 reaper = get_proc_task(filp->f_path.dentry->d_inode); 3350 if (!reaper) 3351 goto out_no_task; 3352 3353 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 3354 const struct pid_entry *p = &proc_base_stuff[nr]; 3355 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 3356 goto out; 3357 } 3358 3359 ns = filp->f_dentry->d_sb->s_fs_info; 3360 iter.task = NULL; 3361 iter.tgid = filp->f_pos - TGID_OFFSET; 3362 for (iter = next_tgid(ns, iter); 3363 iter.task; 3364 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3365 if (has_pid_permissions(ns, iter.task, 2)) 3366 __filldir = filldir; 3367 else 3368 __filldir = fake_filldir; 3369 3370 filp->f_pos = iter.tgid + TGID_OFFSET; 3371 if (proc_pid_fill_cache(filp, dirent, __filldir, iter) < 0) { 3372 put_task_struct(iter.task); 3373 goto out; 3374 } 3375 } 3376 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 3377 out: 3378 put_task_struct(reaper); 3379 out_no_task: 3380 return 0; 3381 } 3382 3383 /* 3384 * Tasks 3385 */ 3386 static const struct pid_entry tid_base_stuff[] = { 3387 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3388 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3389 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3390 REG("environ", S_IRUSR, proc_environ_operations), 3391 INF("auxv", S_IRUSR, proc_pid_auxv), 3392 ONE("status", S_IRUGO, proc_pid_status), 3393 ONE("personality", S_IRUGO, proc_pid_personality), 3394 INF("limits", S_IRUGO, proc_pid_limits), 3395 #ifdef CONFIG_SCHED_DEBUG 3396 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3397 #endif 3398 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3399 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3400 INF("syscall", S_IRUGO, proc_pid_syscall), 3401 #endif 3402 INF("cmdline", S_IRUGO, proc_pid_cmdline), 3403 ONE("stat", S_IRUGO, proc_tid_stat), 3404 ONE("statm", S_IRUGO, proc_pid_statm), 3405 REG("maps", S_IRUGO, proc_tid_maps_operations), 3406 #ifdef CONFIG_CHECKPOINT_RESTORE 3407 REG("children", S_IRUGO, proc_tid_children_operations), 3408 #endif 3409 #ifdef CONFIG_NUMA 3410 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations), 3411 #endif 3412 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3413 LNK("cwd", proc_cwd_link), 3414 LNK("root", proc_root_link), 3415 LNK("exe", proc_exe_link), 3416 REG("mounts", S_IRUGO, proc_mounts_operations), 3417 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3418 #ifdef CONFIG_PROC_PAGE_MONITOR 3419 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3420 REG("smaps", S_IRUGO, proc_tid_smaps_operations), 3421 REG("pagemap", S_IRUGO, proc_pagemap_operations), 3422 #endif 3423 #ifdef CONFIG_SECURITY 3424 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3425 #endif 3426 #ifdef CONFIG_KALLSYMS 3427 INF("wchan", S_IRUGO, proc_pid_wchan), 3428 #endif 3429 #ifdef CONFIG_STACKTRACE 3430 ONE("stack", S_IRUGO, proc_pid_stack), 3431 #endif 3432 #ifdef CONFIG_SCHEDSTATS 3433 INF("schedstat", S_IRUGO, proc_pid_schedstat), 3434 #endif 3435 #ifdef CONFIG_LATENCYTOP 3436 REG("latency", S_IRUGO, proc_lstats_operations), 3437 #endif 3438 #ifdef CONFIG_PROC_PID_CPUSET 3439 REG("cpuset", S_IRUGO, proc_cpuset_operations), 3440 #endif 3441 #ifdef CONFIG_CGROUPS 3442 REG("cgroup", S_IRUGO, proc_cgroup_operations), 3443 #endif 3444 INF("oom_score", S_IRUGO, proc_oom_score), 3445 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 3446 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3447 #ifdef CONFIG_AUDITSYSCALL 3448 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3449 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3450 #endif 3451 #ifdef CONFIG_FAULT_INJECTION 3452 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3453 #endif 3454 #ifdef CONFIG_TASK_IO_ACCOUNTING 3455 INF("io", S_IRUSR, proc_tid_io_accounting), 3456 #endif 3457 #ifdef CONFIG_HARDWALL 3458 INF("hardwall", S_IRUGO, proc_pid_hardwall), 3459 #endif 3460 #ifdef CONFIG_USER_NS 3461 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3462 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3463 #endif 3464 }; 3465 3466 static int proc_tid_base_readdir(struct file * filp, 3467 void * dirent, filldir_t filldir) 3468 { 3469 return proc_pident_readdir(filp,dirent,filldir, 3470 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 3471 } 3472 3473 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 3474 return proc_pident_lookup(dir, dentry, 3475 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3476 } 3477 3478 static const struct file_operations proc_tid_base_operations = { 3479 .read = generic_read_dir, 3480 .readdir = proc_tid_base_readdir, 3481 .llseek = default_llseek, 3482 }; 3483 3484 static const struct inode_operations proc_tid_base_inode_operations = { 3485 .lookup = proc_tid_base_lookup, 3486 .getattr = pid_getattr, 3487 .setattr = proc_setattr, 3488 }; 3489 3490 static struct dentry *proc_task_instantiate(struct inode *dir, 3491 struct dentry *dentry, struct task_struct *task, const void *ptr) 3492 { 3493 struct dentry *error = ERR_PTR(-ENOENT); 3494 struct inode *inode; 3495 inode = proc_pid_make_inode(dir->i_sb, task); 3496 3497 if (!inode) 3498 goto out; 3499 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3500 inode->i_op = &proc_tid_base_inode_operations; 3501 inode->i_fop = &proc_tid_base_operations; 3502 inode->i_flags|=S_IMMUTABLE; 3503 3504 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff, 3505 ARRAY_SIZE(tid_base_stuff))); 3506 3507 d_set_d_op(dentry, &pid_dentry_operations); 3508 3509 d_add(dentry, inode); 3510 /* Close the race of the process dying before we return the dentry */ 3511 if (pid_revalidate(dentry, NULL)) 3512 error = NULL; 3513 out: 3514 return error; 3515 } 3516 3517 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 3518 { 3519 struct dentry *result = ERR_PTR(-ENOENT); 3520 struct task_struct *task; 3521 struct task_struct *leader = get_proc_task(dir); 3522 unsigned tid; 3523 struct pid_namespace *ns; 3524 3525 if (!leader) 3526 goto out_no_task; 3527 3528 tid = name_to_int(dentry); 3529 if (tid == ~0U) 3530 goto out; 3531 3532 ns = dentry->d_sb->s_fs_info; 3533 rcu_read_lock(); 3534 task = find_task_by_pid_ns(tid, ns); 3535 if (task) 3536 get_task_struct(task); 3537 rcu_read_unlock(); 3538 if (!task) 3539 goto out; 3540 if (!same_thread_group(leader, task)) 3541 goto out_drop_task; 3542 3543 result = proc_task_instantiate(dir, dentry, task, NULL); 3544 out_drop_task: 3545 put_task_struct(task); 3546 out: 3547 put_task_struct(leader); 3548 out_no_task: 3549 return result; 3550 } 3551 3552 /* 3553 * Find the first tid of a thread group to return to user space. 3554 * 3555 * Usually this is just the thread group leader, but if the users 3556 * buffer was too small or there was a seek into the middle of the 3557 * directory we have more work todo. 3558 * 3559 * In the case of a short read we start with find_task_by_pid. 3560 * 3561 * In the case of a seek we start with the leader and walk nr 3562 * threads past it. 3563 */ 3564 static struct task_struct *first_tid(struct task_struct *leader, 3565 int tid, int nr, struct pid_namespace *ns) 3566 { 3567 struct task_struct *pos; 3568 3569 rcu_read_lock(); 3570 /* Attempt to start with the pid of a thread */ 3571 if (tid && (nr > 0)) { 3572 pos = find_task_by_pid_ns(tid, ns); 3573 if (pos && (pos->group_leader == leader)) 3574 goto found; 3575 } 3576 3577 /* If nr exceeds the number of threads there is nothing todo */ 3578 pos = NULL; 3579 if (nr && nr >= get_nr_threads(leader)) 3580 goto out; 3581 3582 /* If we haven't found our starting place yet start 3583 * with the leader and walk nr threads forward. 3584 */ 3585 for (pos = leader; nr > 0; --nr) { 3586 pos = next_thread(pos); 3587 if (pos == leader) { 3588 pos = NULL; 3589 goto out; 3590 } 3591 } 3592 found: 3593 get_task_struct(pos); 3594 out: 3595 rcu_read_unlock(); 3596 return pos; 3597 } 3598 3599 /* 3600 * Find the next thread in the thread list. 3601 * Return NULL if there is an error or no next thread. 3602 * 3603 * The reference to the input task_struct is released. 3604 */ 3605 static struct task_struct *next_tid(struct task_struct *start) 3606 { 3607 struct task_struct *pos = NULL; 3608 rcu_read_lock(); 3609 if (pid_alive(start)) { 3610 pos = next_thread(start); 3611 if (thread_group_leader(pos)) 3612 pos = NULL; 3613 else 3614 get_task_struct(pos); 3615 } 3616 rcu_read_unlock(); 3617 put_task_struct(start); 3618 return pos; 3619 } 3620 3621 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3622 struct task_struct *task, int tid) 3623 { 3624 char name[PROC_NUMBUF]; 3625 int len = snprintf(name, sizeof(name), "%d", tid); 3626 return proc_fill_cache(filp, dirent, filldir, name, len, 3627 proc_task_instantiate, task, NULL); 3628 } 3629 3630 /* for the /proc/TGID/task/ directories */ 3631 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 3632 { 3633 struct dentry *dentry = filp->f_path.dentry; 3634 struct inode *inode = dentry->d_inode; 3635 struct task_struct *leader = NULL; 3636 struct task_struct *task; 3637 int retval = -ENOENT; 3638 ino_t ino; 3639 int tid; 3640 struct pid_namespace *ns; 3641 3642 task = get_proc_task(inode); 3643 if (!task) 3644 goto out_no_task; 3645 rcu_read_lock(); 3646 if (pid_alive(task)) { 3647 leader = task->group_leader; 3648 get_task_struct(leader); 3649 } 3650 rcu_read_unlock(); 3651 put_task_struct(task); 3652 if (!leader) 3653 goto out_no_task; 3654 retval = 0; 3655 3656 switch ((unsigned long)filp->f_pos) { 3657 case 0: 3658 ino = inode->i_ino; 3659 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0) 3660 goto out; 3661 filp->f_pos++; 3662 /* fall through */ 3663 case 1: 3664 ino = parent_ino(dentry); 3665 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0) 3666 goto out; 3667 filp->f_pos++; 3668 /* fall through */ 3669 } 3670 3671 /* f_version caches the tgid value that the last readdir call couldn't 3672 * return. lseek aka telldir automagically resets f_version to 0. 3673 */ 3674 ns = filp->f_dentry->d_sb->s_fs_info; 3675 tid = (int)filp->f_version; 3676 filp->f_version = 0; 3677 for (task = first_tid(leader, tid, filp->f_pos - 2, ns); 3678 task; 3679 task = next_tid(task), filp->f_pos++) { 3680 tid = task_pid_nr_ns(task, ns); 3681 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 3682 /* returning this tgid failed, save it as the first 3683 * pid for the next readir call */ 3684 filp->f_version = (u64)tid; 3685 put_task_struct(task); 3686 break; 3687 } 3688 } 3689 out: 3690 put_task_struct(leader); 3691 out_no_task: 3692 return retval; 3693 } 3694 3695 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3696 { 3697 struct inode *inode = dentry->d_inode; 3698 struct task_struct *p = get_proc_task(inode); 3699 generic_fillattr(inode, stat); 3700 3701 if (p) { 3702 stat->nlink += get_nr_threads(p); 3703 put_task_struct(p); 3704 } 3705 3706 return 0; 3707 } 3708 3709 static const struct inode_operations proc_task_inode_operations = { 3710 .lookup = proc_task_lookup, 3711 .getattr = proc_task_getattr, 3712 .setattr = proc_setattr, 3713 .permission = proc_pid_permission, 3714 }; 3715 3716 static const struct file_operations proc_task_operations = { 3717 .read = generic_read_dir, 3718 .readdir = proc_task_readdir, 3719 .llseek = default_llseek, 3720 }; 3721