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 i_mode, 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 i_mode = S_IFLNK; 1823 if (f_mode & FMODE_READ) 1824 i_mode |= S_IRUSR | S_IXUSR; 1825 if (f_mode & FMODE_WRITE) 1826 i_mode |= S_IWUSR | S_IXUSR; 1827 inode->i_mode = i_mode; 1828 1829 security_task_to_inode(task, inode); 1830 put_task_struct(task); 1831 return 1; 1832 } 1833 rcu_read_unlock(); 1834 put_files_struct(files); 1835 } 1836 put_task_struct(task); 1837 } 1838 d_drop(dentry); 1839 return 0; 1840 } 1841 1842 static const struct dentry_operations tid_fd_dentry_operations = 1843 { 1844 .d_revalidate = tid_fd_revalidate, 1845 .d_delete = pid_delete_dentry, 1846 }; 1847 1848 static struct dentry *proc_fd_instantiate(struct inode *dir, 1849 struct dentry *dentry, struct task_struct *task, const void *ptr) 1850 { 1851 unsigned fd = (unsigned long)ptr; 1852 struct inode *inode; 1853 struct proc_inode *ei; 1854 struct dentry *error = ERR_PTR(-ENOENT); 1855 1856 inode = proc_pid_make_inode(dir->i_sb, task); 1857 if (!inode) 1858 goto out; 1859 ei = PROC_I(inode); 1860 ei->fd = fd; 1861 1862 inode->i_op = &proc_pid_link_inode_operations; 1863 inode->i_size = 64; 1864 ei->op.proc_get_link = proc_fd_link; 1865 d_set_d_op(dentry, &tid_fd_dentry_operations); 1866 d_add(dentry, inode); 1867 /* Close the race of the process dying before we return the dentry */ 1868 if (tid_fd_revalidate(dentry, NULL)) 1869 error = NULL; 1870 1871 out: 1872 return error; 1873 } 1874 1875 static struct dentry *proc_lookupfd_common(struct inode *dir, 1876 struct dentry *dentry, 1877 instantiate_t instantiate) 1878 { 1879 struct task_struct *task = get_proc_task(dir); 1880 unsigned fd = name_to_int(dentry); 1881 struct dentry *result = ERR_PTR(-ENOENT); 1882 1883 if (!task) 1884 goto out_no_task; 1885 if (fd == ~0U) 1886 goto out; 1887 1888 result = instantiate(dir, dentry, task, (void *)(unsigned long)fd); 1889 out: 1890 put_task_struct(task); 1891 out_no_task: 1892 return result; 1893 } 1894 1895 static int proc_readfd_common(struct file * filp, void * dirent, 1896 filldir_t filldir, instantiate_t instantiate) 1897 { 1898 struct dentry *dentry = filp->f_path.dentry; 1899 struct inode *inode = dentry->d_inode; 1900 struct task_struct *p = get_proc_task(inode); 1901 unsigned int fd, ino; 1902 int retval; 1903 struct files_struct * files; 1904 1905 retval = -ENOENT; 1906 if (!p) 1907 goto out_no_task; 1908 retval = 0; 1909 1910 fd = filp->f_pos; 1911 switch (fd) { 1912 case 0: 1913 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 1914 goto out; 1915 filp->f_pos++; 1916 case 1: 1917 ino = parent_ino(dentry); 1918 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 1919 goto out; 1920 filp->f_pos++; 1921 default: 1922 files = get_files_struct(p); 1923 if (!files) 1924 goto out; 1925 rcu_read_lock(); 1926 for (fd = filp->f_pos-2; 1927 fd < files_fdtable(files)->max_fds; 1928 fd++, filp->f_pos++) { 1929 char name[PROC_NUMBUF]; 1930 int len; 1931 int rv; 1932 1933 if (!fcheck_files(files, fd)) 1934 continue; 1935 rcu_read_unlock(); 1936 1937 len = snprintf(name, sizeof(name), "%d", fd); 1938 rv = proc_fill_cache(filp, dirent, filldir, 1939 name, len, instantiate, p, 1940 (void *)(unsigned long)fd); 1941 if (rv < 0) 1942 goto out_fd_loop; 1943 rcu_read_lock(); 1944 } 1945 rcu_read_unlock(); 1946 out_fd_loop: 1947 put_files_struct(files); 1948 } 1949 out: 1950 put_task_struct(p); 1951 out_no_task: 1952 return retval; 1953 } 1954 1955 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 1956 struct nameidata *nd) 1957 { 1958 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 1959 } 1960 1961 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 1962 { 1963 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 1964 } 1965 1966 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 1967 size_t len, loff_t *ppos) 1968 { 1969 char tmp[PROC_FDINFO_MAX]; 1970 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); 1971 if (!err) 1972 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 1973 return err; 1974 } 1975 1976 static const struct file_operations proc_fdinfo_file_operations = { 1977 .open = nonseekable_open, 1978 .read = proc_fdinfo_read, 1979 .llseek = no_llseek, 1980 }; 1981 1982 static const struct file_operations proc_fd_operations = { 1983 .read = generic_read_dir, 1984 .readdir = proc_readfd, 1985 .llseek = default_llseek, 1986 }; 1987 1988 #ifdef CONFIG_CHECKPOINT_RESTORE 1989 1990 /* 1991 * dname_to_vma_addr - maps a dentry name into two unsigned longs 1992 * which represent vma start and end addresses. 1993 */ 1994 static int dname_to_vma_addr(struct dentry *dentry, 1995 unsigned long *start, unsigned long *end) 1996 { 1997 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2) 1998 return -EINVAL; 1999 2000 return 0; 2001 } 2002 2003 static int map_files_d_revalidate(struct dentry *dentry, struct nameidata *nd) 2004 { 2005 unsigned long vm_start, vm_end; 2006 bool exact_vma_exists = false; 2007 struct mm_struct *mm = NULL; 2008 struct task_struct *task; 2009 const struct cred *cred; 2010 struct inode *inode; 2011 int status = 0; 2012 2013 if (nd && nd->flags & LOOKUP_RCU) 2014 return -ECHILD; 2015 2016 if (!capable(CAP_SYS_ADMIN)) { 2017 status = -EACCES; 2018 goto out_notask; 2019 } 2020 2021 inode = dentry->d_inode; 2022 task = get_proc_task(inode); 2023 if (!task) 2024 goto out_notask; 2025 2026 mm = mm_access(task, PTRACE_MODE_READ); 2027 if (IS_ERR_OR_NULL(mm)) 2028 goto out; 2029 2030 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 2031 down_read(&mm->mmap_sem); 2032 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end); 2033 up_read(&mm->mmap_sem); 2034 } 2035 2036 mmput(mm); 2037 2038 if (exact_vma_exists) { 2039 if (task_dumpable(task)) { 2040 rcu_read_lock(); 2041 cred = __task_cred(task); 2042 inode->i_uid = cred->euid; 2043 inode->i_gid = cred->egid; 2044 rcu_read_unlock(); 2045 } else { 2046 inode->i_uid = GLOBAL_ROOT_UID; 2047 inode->i_gid = GLOBAL_ROOT_GID; 2048 } 2049 security_task_to_inode(task, inode); 2050 status = 1; 2051 } 2052 2053 out: 2054 put_task_struct(task); 2055 2056 out_notask: 2057 if (status <= 0) 2058 d_drop(dentry); 2059 2060 return status; 2061 } 2062 2063 static const struct dentry_operations tid_map_files_dentry_operations = { 2064 .d_revalidate = map_files_d_revalidate, 2065 .d_delete = pid_delete_dentry, 2066 }; 2067 2068 static int proc_map_files_get_link(struct dentry *dentry, struct path *path) 2069 { 2070 unsigned long vm_start, vm_end; 2071 struct vm_area_struct *vma; 2072 struct task_struct *task; 2073 struct mm_struct *mm; 2074 int rc; 2075 2076 rc = -ENOENT; 2077 task = get_proc_task(dentry->d_inode); 2078 if (!task) 2079 goto out; 2080 2081 mm = get_task_mm(task); 2082 put_task_struct(task); 2083 if (!mm) 2084 goto out; 2085 2086 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 2087 if (rc) 2088 goto out_mmput; 2089 2090 down_read(&mm->mmap_sem); 2091 vma = find_exact_vma(mm, vm_start, vm_end); 2092 if (vma && vma->vm_file) { 2093 *path = vma->vm_file->f_path; 2094 path_get(path); 2095 rc = 0; 2096 } 2097 up_read(&mm->mmap_sem); 2098 2099 out_mmput: 2100 mmput(mm); 2101 out: 2102 return rc; 2103 } 2104 2105 struct map_files_info { 2106 struct file *file; 2107 unsigned long len; 2108 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */ 2109 }; 2110 2111 static struct dentry * 2112 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry, 2113 struct task_struct *task, const void *ptr) 2114 { 2115 const struct file *file = ptr; 2116 struct proc_inode *ei; 2117 struct inode *inode; 2118 2119 if (!file) 2120 return ERR_PTR(-ENOENT); 2121 2122 inode = proc_pid_make_inode(dir->i_sb, task); 2123 if (!inode) 2124 return ERR_PTR(-ENOENT); 2125 2126 ei = PROC_I(inode); 2127 ei->op.proc_get_link = proc_map_files_get_link; 2128 2129 inode->i_op = &proc_pid_link_inode_operations; 2130 inode->i_size = 64; 2131 inode->i_mode = S_IFLNK; 2132 2133 if (file->f_mode & FMODE_READ) 2134 inode->i_mode |= S_IRUSR; 2135 if (file->f_mode & FMODE_WRITE) 2136 inode->i_mode |= S_IWUSR; 2137 2138 d_set_d_op(dentry, &tid_map_files_dentry_operations); 2139 d_add(dentry, inode); 2140 2141 return NULL; 2142 } 2143 2144 static struct dentry *proc_map_files_lookup(struct inode *dir, 2145 struct dentry *dentry, struct nameidata *nd) 2146 { 2147 unsigned long vm_start, vm_end; 2148 struct vm_area_struct *vma; 2149 struct task_struct *task; 2150 struct dentry *result; 2151 struct mm_struct *mm; 2152 2153 result = ERR_PTR(-EACCES); 2154 if (!capable(CAP_SYS_ADMIN)) 2155 goto out; 2156 2157 result = ERR_PTR(-ENOENT); 2158 task = get_proc_task(dir); 2159 if (!task) 2160 goto out; 2161 2162 result = ERR_PTR(-EACCES); 2163 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 2164 goto out_put_task; 2165 2166 result = ERR_PTR(-ENOENT); 2167 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 2168 goto out_put_task; 2169 2170 mm = get_task_mm(task); 2171 if (!mm) 2172 goto out_put_task; 2173 2174 down_read(&mm->mmap_sem); 2175 vma = find_exact_vma(mm, vm_start, vm_end); 2176 if (!vma) 2177 goto out_no_vma; 2178 2179 result = proc_map_files_instantiate(dir, dentry, task, vma->vm_file); 2180 2181 out_no_vma: 2182 up_read(&mm->mmap_sem); 2183 mmput(mm); 2184 out_put_task: 2185 put_task_struct(task); 2186 out: 2187 return result; 2188 } 2189 2190 static const struct inode_operations proc_map_files_inode_operations = { 2191 .lookup = proc_map_files_lookup, 2192 .permission = proc_fd_permission, 2193 .setattr = proc_setattr, 2194 }; 2195 2196 static int 2197 proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir) 2198 { 2199 struct dentry *dentry = filp->f_path.dentry; 2200 struct inode *inode = dentry->d_inode; 2201 struct vm_area_struct *vma; 2202 struct task_struct *task; 2203 struct mm_struct *mm; 2204 ino_t ino; 2205 int ret; 2206 2207 ret = -EACCES; 2208 if (!capable(CAP_SYS_ADMIN)) 2209 goto out; 2210 2211 ret = -ENOENT; 2212 task = get_proc_task(inode); 2213 if (!task) 2214 goto out; 2215 2216 ret = -EACCES; 2217 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 2218 goto out_put_task; 2219 2220 ret = 0; 2221 switch (filp->f_pos) { 2222 case 0: 2223 ino = inode->i_ino; 2224 if (filldir(dirent, ".", 1, 0, ino, DT_DIR) < 0) 2225 goto out_put_task; 2226 filp->f_pos++; 2227 case 1: 2228 ino = parent_ino(dentry); 2229 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 2230 goto out_put_task; 2231 filp->f_pos++; 2232 default: 2233 { 2234 unsigned long nr_files, pos, i; 2235 struct flex_array *fa = NULL; 2236 struct map_files_info info; 2237 struct map_files_info *p; 2238 2239 mm = get_task_mm(task); 2240 if (!mm) 2241 goto out_put_task; 2242 down_read(&mm->mmap_sem); 2243 2244 nr_files = 0; 2245 2246 /* 2247 * We need two passes here: 2248 * 2249 * 1) Collect vmas of mapped files with mmap_sem taken 2250 * 2) Release mmap_sem and instantiate entries 2251 * 2252 * otherwise we get lockdep complained, since filldir() 2253 * routine might require mmap_sem taken in might_fault(). 2254 */ 2255 2256 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 2257 if (vma->vm_file && ++pos > filp->f_pos) 2258 nr_files++; 2259 } 2260 2261 if (nr_files) { 2262 fa = flex_array_alloc(sizeof(info), nr_files, 2263 GFP_KERNEL); 2264 if (!fa || flex_array_prealloc(fa, 0, nr_files, 2265 GFP_KERNEL)) { 2266 ret = -ENOMEM; 2267 if (fa) 2268 flex_array_free(fa); 2269 up_read(&mm->mmap_sem); 2270 mmput(mm); 2271 goto out_put_task; 2272 } 2273 for (i = 0, vma = mm->mmap, pos = 2; vma; 2274 vma = vma->vm_next) { 2275 if (!vma->vm_file) 2276 continue; 2277 if (++pos <= filp->f_pos) 2278 continue; 2279 2280 get_file(vma->vm_file); 2281 info.file = vma->vm_file; 2282 info.len = snprintf(info.name, 2283 sizeof(info.name), "%lx-%lx", 2284 vma->vm_start, vma->vm_end); 2285 if (flex_array_put(fa, i++, &info, GFP_KERNEL)) 2286 BUG(); 2287 } 2288 } 2289 up_read(&mm->mmap_sem); 2290 2291 for (i = 0; i < nr_files; i++) { 2292 p = flex_array_get(fa, i); 2293 ret = proc_fill_cache(filp, dirent, filldir, 2294 p->name, p->len, 2295 proc_map_files_instantiate, 2296 task, p->file); 2297 if (ret) 2298 break; 2299 filp->f_pos++; 2300 fput(p->file); 2301 } 2302 for (; i < nr_files; i++) { 2303 /* 2304 * In case of error don't forget 2305 * to put rest of file refs. 2306 */ 2307 p = flex_array_get(fa, i); 2308 fput(p->file); 2309 } 2310 if (fa) 2311 flex_array_free(fa); 2312 mmput(mm); 2313 } 2314 } 2315 2316 out_put_task: 2317 put_task_struct(task); 2318 out: 2319 return ret; 2320 } 2321 2322 static const struct file_operations proc_map_files_operations = { 2323 .read = generic_read_dir, 2324 .readdir = proc_map_files_readdir, 2325 .llseek = default_llseek, 2326 }; 2327 2328 #endif /* CONFIG_CHECKPOINT_RESTORE */ 2329 2330 /* 2331 * /proc/pid/fd needs a special permission handler so that a process can still 2332 * access /proc/self/fd after it has executed a setuid(). 2333 */ 2334 static int proc_fd_permission(struct inode *inode, int mask) 2335 { 2336 int rv = generic_permission(inode, mask); 2337 if (rv == 0) 2338 return 0; 2339 if (task_pid(current) == proc_pid(inode)) 2340 rv = 0; 2341 return rv; 2342 } 2343 2344 /* 2345 * proc directories can do almost nothing.. 2346 */ 2347 static const struct inode_operations proc_fd_inode_operations = { 2348 .lookup = proc_lookupfd, 2349 .permission = proc_fd_permission, 2350 .setattr = proc_setattr, 2351 }; 2352 2353 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 2354 struct dentry *dentry, struct task_struct *task, const void *ptr) 2355 { 2356 unsigned fd = (unsigned long)ptr; 2357 struct inode *inode; 2358 struct proc_inode *ei; 2359 struct dentry *error = ERR_PTR(-ENOENT); 2360 2361 inode = proc_pid_make_inode(dir->i_sb, task); 2362 if (!inode) 2363 goto out; 2364 ei = PROC_I(inode); 2365 ei->fd = fd; 2366 inode->i_mode = S_IFREG | S_IRUSR; 2367 inode->i_fop = &proc_fdinfo_file_operations; 2368 d_set_d_op(dentry, &tid_fd_dentry_operations); 2369 d_add(dentry, inode); 2370 /* Close the race of the process dying before we return the dentry */ 2371 if (tid_fd_revalidate(dentry, NULL)) 2372 error = NULL; 2373 2374 out: 2375 return error; 2376 } 2377 2378 static struct dentry *proc_lookupfdinfo(struct inode *dir, 2379 struct dentry *dentry, 2380 struct nameidata *nd) 2381 { 2382 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 2383 } 2384 2385 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 2386 { 2387 return proc_readfd_common(filp, dirent, filldir, 2388 proc_fdinfo_instantiate); 2389 } 2390 2391 static const struct file_operations proc_fdinfo_operations = { 2392 .read = generic_read_dir, 2393 .readdir = proc_readfdinfo, 2394 .llseek = default_llseek, 2395 }; 2396 2397 /* 2398 * proc directories can do almost nothing.. 2399 */ 2400 static const struct inode_operations proc_fdinfo_inode_operations = { 2401 .lookup = proc_lookupfdinfo, 2402 .setattr = proc_setattr, 2403 }; 2404 2405 2406 static struct dentry *proc_pident_instantiate(struct inode *dir, 2407 struct dentry *dentry, struct task_struct *task, const void *ptr) 2408 { 2409 const struct pid_entry *p = ptr; 2410 struct inode *inode; 2411 struct proc_inode *ei; 2412 struct dentry *error = ERR_PTR(-ENOENT); 2413 2414 inode = proc_pid_make_inode(dir->i_sb, task); 2415 if (!inode) 2416 goto out; 2417 2418 ei = PROC_I(inode); 2419 inode->i_mode = p->mode; 2420 if (S_ISDIR(inode->i_mode)) 2421 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2422 if (p->iop) 2423 inode->i_op = p->iop; 2424 if (p->fop) 2425 inode->i_fop = p->fop; 2426 ei->op = p->op; 2427 d_set_d_op(dentry, &pid_dentry_operations); 2428 d_add(dentry, inode); 2429 /* Close the race of the process dying before we return the dentry */ 2430 if (pid_revalidate(dentry, NULL)) 2431 error = NULL; 2432 out: 2433 return error; 2434 } 2435 2436 static struct dentry *proc_pident_lookup(struct inode *dir, 2437 struct dentry *dentry, 2438 const struct pid_entry *ents, 2439 unsigned int nents) 2440 { 2441 struct dentry *error; 2442 struct task_struct *task = get_proc_task(dir); 2443 const struct pid_entry *p, *last; 2444 2445 error = ERR_PTR(-ENOENT); 2446 2447 if (!task) 2448 goto out_no_task; 2449 2450 /* 2451 * Yes, it does not scale. And it should not. Don't add 2452 * new entries into /proc/<tgid>/ without very good reasons. 2453 */ 2454 last = &ents[nents - 1]; 2455 for (p = ents; p <= last; p++) { 2456 if (p->len != dentry->d_name.len) 2457 continue; 2458 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2459 break; 2460 } 2461 if (p > last) 2462 goto out; 2463 2464 error = proc_pident_instantiate(dir, dentry, task, p); 2465 out: 2466 put_task_struct(task); 2467 out_no_task: 2468 return error; 2469 } 2470 2471 static int proc_pident_fill_cache(struct file *filp, void *dirent, 2472 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2473 { 2474 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2475 proc_pident_instantiate, task, p); 2476 } 2477 2478 static int proc_pident_readdir(struct file *filp, 2479 void *dirent, filldir_t filldir, 2480 const struct pid_entry *ents, unsigned int nents) 2481 { 2482 int i; 2483 struct dentry *dentry = filp->f_path.dentry; 2484 struct inode *inode = dentry->d_inode; 2485 struct task_struct *task = get_proc_task(inode); 2486 const struct pid_entry *p, *last; 2487 ino_t ino; 2488 int ret; 2489 2490 ret = -ENOENT; 2491 if (!task) 2492 goto out_no_task; 2493 2494 ret = 0; 2495 i = filp->f_pos; 2496 switch (i) { 2497 case 0: 2498 ino = inode->i_ino; 2499 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 2500 goto out; 2501 i++; 2502 filp->f_pos++; 2503 /* fall through */ 2504 case 1: 2505 ino = parent_ino(dentry); 2506 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 2507 goto out; 2508 i++; 2509 filp->f_pos++; 2510 /* fall through */ 2511 default: 2512 i -= 2; 2513 if (i >= nents) { 2514 ret = 1; 2515 goto out; 2516 } 2517 p = ents + i; 2518 last = &ents[nents - 1]; 2519 while (p <= last) { 2520 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2521 goto out; 2522 filp->f_pos++; 2523 p++; 2524 } 2525 } 2526 2527 ret = 1; 2528 out: 2529 put_task_struct(task); 2530 out_no_task: 2531 return ret; 2532 } 2533 2534 #ifdef CONFIG_SECURITY 2535 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2536 size_t count, loff_t *ppos) 2537 { 2538 struct inode * inode = file->f_path.dentry->d_inode; 2539 char *p = NULL; 2540 ssize_t length; 2541 struct task_struct *task = get_proc_task(inode); 2542 2543 if (!task) 2544 return -ESRCH; 2545 2546 length = security_getprocattr(task, 2547 (char*)file->f_path.dentry->d_name.name, 2548 &p); 2549 put_task_struct(task); 2550 if (length > 0) 2551 length = simple_read_from_buffer(buf, count, ppos, p, length); 2552 kfree(p); 2553 return length; 2554 } 2555 2556 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2557 size_t count, loff_t *ppos) 2558 { 2559 struct inode * inode = file->f_path.dentry->d_inode; 2560 char *page; 2561 ssize_t length; 2562 struct task_struct *task = get_proc_task(inode); 2563 2564 length = -ESRCH; 2565 if (!task) 2566 goto out_no_task; 2567 if (count > PAGE_SIZE) 2568 count = PAGE_SIZE; 2569 2570 /* No partial writes. */ 2571 length = -EINVAL; 2572 if (*ppos != 0) 2573 goto out; 2574 2575 length = -ENOMEM; 2576 page = (char*)__get_free_page(GFP_TEMPORARY); 2577 if (!page) 2578 goto out; 2579 2580 length = -EFAULT; 2581 if (copy_from_user(page, buf, count)) 2582 goto out_free; 2583 2584 /* Guard against adverse ptrace interaction */ 2585 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex); 2586 if (length < 0) 2587 goto out_free; 2588 2589 length = security_setprocattr(task, 2590 (char*)file->f_path.dentry->d_name.name, 2591 (void*)page, count); 2592 mutex_unlock(&task->signal->cred_guard_mutex); 2593 out_free: 2594 free_page((unsigned long) page); 2595 out: 2596 put_task_struct(task); 2597 out_no_task: 2598 return length; 2599 } 2600 2601 static const struct file_operations proc_pid_attr_operations = { 2602 .read = proc_pid_attr_read, 2603 .write = proc_pid_attr_write, 2604 .llseek = generic_file_llseek, 2605 }; 2606 2607 static const struct pid_entry attr_dir_stuff[] = { 2608 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2609 REG("prev", S_IRUGO, proc_pid_attr_operations), 2610 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2611 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2612 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2613 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2614 }; 2615 2616 static int proc_attr_dir_readdir(struct file * filp, 2617 void * dirent, filldir_t filldir) 2618 { 2619 return proc_pident_readdir(filp,dirent,filldir, 2620 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2621 } 2622 2623 static const struct file_operations proc_attr_dir_operations = { 2624 .read = generic_read_dir, 2625 .readdir = proc_attr_dir_readdir, 2626 .llseek = default_llseek, 2627 }; 2628 2629 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2630 struct dentry *dentry, struct nameidata *nd) 2631 { 2632 return proc_pident_lookup(dir, dentry, 2633 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2634 } 2635 2636 static const struct inode_operations proc_attr_dir_inode_operations = { 2637 .lookup = proc_attr_dir_lookup, 2638 .getattr = pid_getattr, 2639 .setattr = proc_setattr, 2640 }; 2641 2642 #endif 2643 2644 #ifdef CONFIG_ELF_CORE 2645 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2646 size_t count, loff_t *ppos) 2647 { 2648 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2649 struct mm_struct *mm; 2650 char buffer[PROC_NUMBUF]; 2651 size_t len; 2652 int ret; 2653 2654 if (!task) 2655 return -ESRCH; 2656 2657 ret = 0; 2658 mm = get_task_mm(task); 2659 if (mm) { 2660 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2661 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2662 MMF_DUMP_FILTER_SHIFT)); 2663 mmput(mm); 2664 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2665 } 2666 2667 put_task_struct(task); 2668 2669 return ret; 2670 } 2671 2672 static ssize_t proc_coredump_filter_write(struct file *file, 2673 const char __user *buf, 2674 size_t count, 2675 loff_t *ppos) 2676 { 2677 struct task_struct *task; 2678 struct mm_struct *mm; 2679 char buffer[PROC_NUMBUF], *end; 2680 unsigned int val; 2681 int ret; 2682 int i; 2683 unsigned long mask; 2684 2685 ret = -EFAULT; 2686 memset(buffer, 0, sizeof(buffer)); 2687 if (count > sizeof(buffer) - 1) 2688 count = sizeof(buffer) - 1; 2689 if (copy_from_user(buffer, buf, count)) 2690 goto out_no_task; 2691 2692 ret = -EINVAL; 2693 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2694 if (*end == '\n') 2695 end++; 2696 if (end - buffer == 0) 2697 goto out_no_task; 2698 2699 ret = -ESRCH; 2700 task = get_proc_task(file->f_dentry->d_inode); 2701 if (!task) 2702 goto out_no_task; 2703 2704 ret = end - buffer; 2705 mm = get_task_mm(task); 2706 if (!mm) 2707 goto out_no_mm; 2708 2709 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2710 if (val & mask) 2711 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2712 else 2713 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2714 } 2715 2716 mmput(mm); 2717 out_no_mm: 2718 put_task_struct(task); 2719 out_no_task: 2720 return ret; 2721 } 2722 2723 static const struct file_operations proc_coredump_filter_operations = { 2724 .read = proc_coredump_filter_read, 2725 .write = proc_coredump_filter_write, 2726 .llseek = generic_file_llseek, 2727 }; 2728 #endif 2729 2730 /* 2731 * /proc/self: 2732 */ 2733 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2734 int buflen) 2735 { 2736 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2737 pid_t tgid = task_tgid_nr_ns(current, ns); 2738 char tmp[PROC_NUMBUF]; 2739 if (!tgid) 2740 return -ENOENT; 2741 sprintf(tmp, "%d", tgid); 2742 return vfs_readlink(dentry,buffer,buflen,tmp); 2743 } 2744 2745 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2746 { 2747 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2748 pid_t tgid = task_tgid_nr_ns(current, ns); 2749 char *name = ERR_PTR(-ENOENT); 2750 if (tgid) { 2751 name = __getname(); 2752 if (!name) 2753 name = ERR_PTR(-ENOMEM); 2754 else 2755 sprintf(name, "%d", tgid); 2756 } 2757 nd_set_link(nd, name); 2758 return NULL; 2759 } 2760 2761 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd, 2762 void *cookie) 2763 { 2764 char *s = nd_get_link(nd); 2765 if (!IS_ERR(s)) 2766 __putname(s); 2767 } 2768 2769 static const struct inode_operations proc_self_inode_operations = { 2770 .readlink = proc_self_readlink, 2771 .follow_link = proc_self_follow_link, 2772 .put_link = proc_self_put_link, 2773 }; 2774 2775 /* 2776 * proc base 2777 * 2778 * These are the directory entries in the root directory of /proc 2779 * that properly belong to the /proc filesystem, as they describe 2780 * describe something that is process related. 2781 */ 2782 static const struct pid_entry proc_base_stuff[] = { 2783 NOD("self", S_IFLNK|S_IRWXUGO, 2784 &proc_self_inode_operations, NULL, {}), 2785 }; 2786 2787 static struct dentry *proc_base_instantiate(struct inode *dir, 2788 struct dentry *dentry, struct task_struct *task, const void *ptr) 2789 { 2790 const struct pid_entry *p = ptr; 2791 struct inode *inode; 2792 struct proc_inode *ei; 2793 struct dentry *error; 2794 2795 /* Allocate the inode */ 2796 error = ERR_PTR(-ENOMEM); 2797 inode = new_inode(dir->i_sb); 2798 if (!inode) 2799 goto out; 2800 2801 /* Initialize the inode */ 2802 ei = PROC_I(inode); 2803 inode->i_ino = get_next_ino(); 2804 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2805 2806 /* 2807 * grab the reference to the task. 2808 */ 2809 ei->pid = get_task_pid(task, PIDTYPE_PID); 2810 if (!ei->pid) 2811 goto out_iput; 2812 2813 inode->i_mode = p->mode; 2814 if (S_ISDIR(inode->i_mode)) 2815 set_nlink(inode, 2); 2816 if (S_ISLNK(inode->i_mode)) 2817 inode->i_size = 64; 2818 if (p->iop) 2819 inode->i_op = p->iop; 2820 if (p->fop) 2821 inode->i_fop = p->fop; 2822 ei->op = p->op; 2823 d_add(dentry, inode); 2824 error = NULL; 2825 out: 2826 return error; 2827 out_iput: 2828 iput(inode); 2829 goto out; 2830 } 2831 2832 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2833 { 2834 struct dentry *error; 2835 struct task_struct *task = get_proc_task(dir); 2836 const struct pid_entry *p, *last; 2837 2838 error = ERR_PTR(-ENOENT); 2839 2840 if (!task) 2841 goto out_no_task; 2842 2843 /* Lookup the directory entry */ 2844 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2845 for (p = proc_base_stuff; p <= last; p++) { 2846 if (p->len != dentry->d_name.len) 2847 continue; 2848 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2849 break; 2850 } 2851 if (p > last) 2852 goto out; 2853 2854 error = proc_base_instantiate(dir, dentry, task, p); 2855 2856 out: 2857 put_task_struct(task); 2858 out_no_task: 2859 return error; 2860 } 2861 2862 static int proc_base_fill_cache(struct file *filp, void *dirent, 2863 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2864 { 2865 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2866 proc_base_instantiate, task, p); 2867 } 2868 2869 #ifdef CONFIG_TASK_IO_ACCOUNTING 2870 static int do_io_accounting(struct task_struct *task, char *buffer, int whole) 2871 { 2872 struct task_io_accounting acct = task->ioac; 2873 unsigned long flags; 2874 int result; 2875 2876 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2877 if (result) 2878 return result; 2879 2880 if (!ptrace_may_access(task, PTRACE_MODE_READ)) { 2881 result = -EACCES; 2882 goto out_unlock; 2883 } 2884 2885 if (whole && lock_task_sighand(task, &flags)) { 2886 struct task_struct *t = task; 2887 2888 task_io_accounting_add(&acct, &task->signal->ioac); 2889 while_each_thread(task, t) 2890 task_io_accounting_add(&acct, &t->ioac); 2891 2892 unlock_task_sighand(task, &flags); 2893 } 2894 result = sprintf(buffer, 2895 "rchar: %llu\n" 2896 "wchar: %llu\n" 2897 "syscr: %llu\n" 2898 "syscw: %llu\n" 2899 "read_bytes: %llu\n" 2900 "write_bytes: %llu\n" 2901 "cancelled_write_bytes: %llu\n", 2902 (unsigned long long)acct.rchar, 2903 (unsigned long long)acct.wchar, 2904 (unsigned long long)acct.syscr, 2905 (unsigned long long)acct.syscw, 2906 (unsigned long long)acct.read_bytes, 2907 (unsigned long long)acct.write_bytes, 2908 (unsigned long long)acct.cancelled_write_bytes); 2909 out_unlock: 2910 mutex_unlock(&task->signal->cred_guard_mutex); 2911 return result; 2912 } 2913 2914 static int proc_tid_io_accounting(struct task_struct *task, char *buffer) 2915 { 2916 return do_io_accounting(task, buffer, 0); 2917 } 2918 2919 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer) 2920 { 2921 return do_io_accounting(task, buffer, 1); 2922 } 2923 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2924 2925 #ifdef CONFIG_USER_NS 2926 static int proc_id_map_open(struct inode *inode, struct file *file, 2927 struct seq_operations *seq_ops) 2928 { 2929 struct user_namespace *ns = NULL; 2930 struct task_struct *task; 2931 struct seq_file *seq; 2932 int ret = -EINVAL; 2933 2934 task = get_proc_task(inode); 2935 if (task) { 2936 rcu_read_lock(); 2937 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2938 rcu_read_unlock(); 2939 put_task_struct(task); 2940 } 2941 if (!ns) 2942 goto err; 2943 2944 ret = seq_open(file, seq_ops); 2945 if (ret) 2946 goto err_put_ns; 2947 2948 seq = file->private_data; 2949 seq->private = ns; 2950 2951 return 0; 2952 err_put_ns: 2953 put_user_ns(ns); 2954 err: 2955 return ret; 2956 } 2957 2958 static int proc_id_map_release(struct inode *inode, struct file *file) 2959 { 2960 struct seq_file *seq = file->private_data; 2961 struct user_namespace *ns = seq->private; 2962 put_user_ns(ns); 2963 return seq_release(inode, file); 2964 } 2965 2966 static int proc_uid_map_open(struct inode *inode, struct file *file) 2967 { 2968 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2969 } 2970 2971 static int proc_gid_map_open(struct inode *inode, struct file *file) 2972 { 2973 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2974 } 2975 2976 static const struct file_operations proc_uid_map_operations = { 2977 .open = proc_uid_map_open, 2978 .write = proc_uid_map_write, 2979 .read = seq_read, 2980 .llseek = seq_lseek, 2981 .release = proc_id_map_release, 2982 }; 2983 2984 static const struct file_operations proc_gid_map_operations = { 2985 .open = proc_gid_map_open, 2986 .write = proc_gid_map_write, 2987 .read = seq_read, 2988 .llseek = seq_lseek, 2989 .release = proc_id_map_release, 2990 }; 2991 #endif /* CONFIG_USER_NS */ 2992 2993 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2994 struct pid *pid, struct task_struct *task) 2995 { 2996 int err = lock_trace(task); 2997 if (!err) { 2998 seq_printf(m, "%08x\n", task->personality); 2999 unlock_trace(task); 3000 } 3001 return err; 3002 } 3003 3004 /* 3005 * Thread groups 3006 */ 3007 static const struct file_operations proc_task_operations; 3008 static const struct inode_operations proc_task_inode_operations; 3009 3010 static const struct pid_entry tgid_base_stuff[] = { 3011 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 3012 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3013 #ifdef CONFIG_CHECKPOINT_RESTORE 3014 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 3015 #endif 3016 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3017 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3018 #ifdef CONFIG_NET 3019 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 3020 #endif 3021 REG("environ", S_IRUSR, proc_environ_operations), 3022 INF("auxv", S_IRUSR, proc_pid_auxv), 3023 ONE("status", S_IRUGO, proc_pid_status), 3024 ONE("personality", S_IRUGO, proc_pid_personality), 3025 INF("limits", S_IRUGO, proc_pid_limits), 3026 #ifdef CONFIG_SCHED_DEBUG 3027 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3028 #endif 3029 #ifdef CONFIG_SCHED_AUTOGROUP 3030 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 3031 #endif 3032 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3033 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3034 INF("syscall", S_IRUGO, proc_pid_syscall), 3035 #endif 3036 INF("cmdline", S_IRUGO, proc_pid_cmdline), 3037 ONE("stat", S_IRUGO, proc_tgid_stat), 3038 ONE("statm", S_IRUGO, proc_pid_statm), 3039 REG("maps", S_IRUGO, proc_pid_maps_operations), 3040 #ifdef CONFIG_NUMA 3041 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 3042 #endif 3043 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3044 LNK("cwd", proc_cwd_link), 3045 LNK("root", proc_root_link), 3046 LNK("exe", proc_exe_link), 3047 REG("mounts", S_IRUGO, proc_mounts_operations), 3048 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3049 REG("mountstats", S_IRUSR, proc_mountstats_operations), 3050 #ifdef CONFIG_PROC_PAGE_MONITOR 3051 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3052 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 3053 REG("pagemap", S_IRUGO, proc_pagemap_operations), 3054 #endif 3055 #ifdef CONFIG_SECURITY 3056 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3057 #endif 3058 #ifdef CONFIG_KALLSYMS 3059 INF("wchan", S_IRUGO, proc_pid_wchan), 3060 #endif 3061 #ifdef CONFIG_STACKTRACE 3062 ONE("stack", S_IRUGO, proc_pid_stack), 3063 #endif 3064 #ifdef CONFIG_SCHEDSTATS 3065 INF("schedstat", S_IRUGO, proc_pid_schedstat), 3066 #endif 3067 #ifdef CONFIG_LATENCYTOP 3068 REG("latency", S_IRUGO, proc_lstats_operations), 3069 #endif 3070 #ifdef CONFIG_PROC_PID_CPUSET 3071 REG("cpuset", S_IRUGO, proc_cpuset_operations), 3072 #endif 3073 #ifdef CONFIG_CGROUPS 3074 REG("cgroup", S_IRUGO, proc_cgroup_operations), 3075 #endif 3076 INF("oom_score", S_IRUGO, proc_oom_score), 3077 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 3078 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3079 #ifdef CONFIG_AUDITSYSCALL 3080 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3081 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3082 #endif 3083 #ifdef CONFIG_FAULT_INJECTION 3084 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3085 #endif 3086 #ifdef CONFIG_ELF_CORE 3087 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 3088 #endif 3089 #ifdef CONFIG_TASK_IO_ACCOUNTING 3090 INF("io", S_IRUSR, proc_tgid_io_accounting), 3091 #endif 3092 #ifdef CONFIG_HARDWALL 3093 INF("hardwall", S_IRUGO, proc_pid_hardwall), 3094 #endif 3095 #ifdef CONFIG_USER_NS 3096 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3097 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3098 #endif 3099 }; 3100 3101 static int proc_tgid_base_readdir(struct file * filp, 3102 void * dirent, filldir_t filldir) 3103 { 3104 return proc_pident_readdir(filp,dirent,filldir, 3105 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 3106 } 3107 3108 static const struct file_operations proc_tgid_base_operations = { 3109 .read = generic_read_dir, 3110 .readdir = proc_tgid_base_readdir, 3111 .llseek = default_llseek, 3112 }; 3113 3114 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 3115 return proc_pident_lookup(dir, dentry, 3116 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 3117 } 3118 3119 static const struct inode_operations proc_tgid_base_inode_operations = { 3120 .lookup = proc_tgid_base_lookup, 3121 .getattr = pid_getattr, 3122 .setattr = proc_setattr, 3123 .permission = proc_pid_permission, 3124 }; 3125 3126 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 3127 { 3128 struct dentry *dentry, *leader, *dir; 3129 char buf[PROC_NUMBUF]; 3130 struct qstr name; 3131 3132 name.name = buf; 3133 name.len = snprintf(buf, sizeof(buf), "%d", pid); 3134 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 3135 if (dentry) { 3136 shrink_dcache_parent(dentry); 3137 d_drop(dentry); 3138 dput(dentry); 3139 } 3140 3141 name.name = buf; 3142 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 3143 leader = d_hash_and_lookup(mnt->mnt_root, &name); 3144 if (!leader) 3145 goto out; 3146 3147 name.name = "task"; 3148 name.len = strlen(name.name); 3149 dir = d_hash_and_lookup(leader, &name); 3150 if (!dir) 3151 goto out_put_leader; 3152 3153 name.name = buf; 3154 name.len = snprintf(buf, sizeof(buf), "%d", pid); 3155 dentry = d_hash_and_lookup(dir, &name); 3156 if (dentry) { 3157 shrink_dcache_parent(dentry); 3158 d_drop(dentry); 3159 dput(dentry); 3160 } 3161 3162 dput(dir); 3163 out_put_leader: 3164 dput(leader); 3165 out: 3166 return; 3167 } 3168 3169 /** 3170 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 3171 * @task: task that should be flushed. 3172 * 3173 * When flushing dentries from proc, one needs to flush them from global 3174 * proc (proc_mnt) and from all the namespaces' procs this task was seen 3175 * in. This call is supposed to do all of this job. 3176 * 3177 * Looks in the dcache for 3178 * /proc/@pid 3179 * /proc/@tgid/task/@pid 3180 * if either directory is present flushes it and all of it'ts children 3181 * from the dcache. 3182 * 3183 * It is safe and reasonable to cache /proc entries for a task until 3184 * that task exits. After that they just clog up the dcache with 3185 * useless entries, possibly causing useful dcache entries to be 3186 * flushed instead. This routine is proved to flush those useless 3187 * dcache entries at process exit time. 3188 * 3189 * NOTE: This routine is just an optimization so it does not guarantee 3190 * that no dcache entries will exist at process exit time it 3191 * just makes it very unlikely that any will persist. 3192 */ 3193 3194 void proc_flush_task(struct task_struct *task) 3195 { 3196 int i; 3197 struct pid *pid, *tgid; 3198 struct upid *upid; 3199 3200 pid = task_pid(task); 3201 tgid = task_tgid(task); 3202 3203 for (i = 0; i <= pid->level; i++) { 3204 upid = &pid->numbers[i]; 3205 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3206 tgid->numbers[i].nr); 3207 } 3208 3209 upid = &pid->numbers[pid->level]; 3210 if (upid->nr == 1) 3211 pid_ns_release_proc(upid->ns); 3212 } 3213 3214 static struct dentry *proc_pid_instantiate(struct inode *dir, 3215 struct dentry * dentry, 3216 struct task_struct *task, const void *ptr) 3217 { 3218 struct dentry *error = ERR_PTR(-ENOENT); 3219 struct inode *inode; 3220 3221 inode = proc_pid_make_inode(dir->i_sb, task); 3222 if (!inode) 3223 goto out; 3224 3225 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3226 inode->i_op = &proc_tgid_base_inode_operations; 3227 inode->i_fop = &proc_tgid_base_operations; 3228 inode->i_flags|=S_IMMUTABLE; 3229 3230 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff, 3231 ARRAY_SIZE(tgid_base_stuff))); 3232 3233 d_set_d_op(dentry, &pid_dentry_operations); 3234 3235 d_add(dentry, inode); 3236 /* Close the race of the process dying before we return the dentry */ 3237 if (pid_revalidate(dentry, NULL)) 3238 error = NULL; 3239 out: 3240 return error; 3241 } 3242 3243 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 3244 { 3245 struct dentry *result; 3246 struct task_struct *task; 3247 unsigned tgid; 3248 struct pid_namespace *ns; 3249 3250 result = proc_base_lookup(dir, dentry); 3251 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 3252 goto out; 3253 3254 tgid = name_to_int(dentry); 3255 if (tgid == ~0U) 3256 goto out; 3257 3258 ns = dentry->d_sb->s_fs_info; 3259 rcu_read_lock(); 3260 task = find_task_by_pid_ns(tgid, ns); 3261 if (task) 3262 get_task_struct(task); 3263 rcu_read_unlock(); 3264 if (!task) 3265 goto out; 3266 3267 result = proc_pid_instantiate(dir, dentry, task, NULL); 3268 put_task_struct(task); 3269 out: 3270 return result; 3271 } 3272 3273 /* 3274 * Find the first task with tgid >= tgid 3275 * 3276 */ 3277 struct tgid_iter { 3278 unsigned int tgid; 3279 struct task_struct *task; 3280 }; 3281 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3282 { 3283 struct pid *pid; 3284 3285 if (iter.task) 3286 put_task_struct(iter.task); 3287 rcu_read_lock(); 3288 retry: 3289 iter.task = NULL; 3290 pid = find_ge_pid(iter.tgid, ns); 3291 if (pid) { 3292 iter.tgid = pid_nr_ns(pid, ns); 3293 iter.task = pid_task(pid, PIDTYPE_PID); 3294 /* What we to know is if the pid we have find is the 3295 * pid of a thread_group_leader. Testing for task 3296 * being a thread_group_leader is the obvious thing 3297 * todo but there is a window when it fails, due to 3298 * the pid transfer logic in de_thread. 3299 * 3300 * So we perform the straight forward test of seeing 3301 * if the pid we have found is the pid of a thread 3302 * group leader, and don't worry if the task we have 3303 * found doesn't happen to be a thread group leader. 3304 * As we don't care in the case of readdir. 3305 */ 3306 if (!iter.task || !has_group_leader_pid(iter.task)) { 3307 iter.tgid += 1; 3308 goto retry; 3309 } 3310 get_task_struct(iter.task); 3311 } 3312 rcu_read_unlock(); 3313 return iter; 3314 } 3315 3316 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 3317 3318 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3319 struct tgid_iter iter) 3320 { 3321 char name[PROC_NUMBUF]; 3322 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 3323 return proc_fill_cache(filp, dirent, filldir, name, len, 3324 proc_pid_instantiate, iter.task, NULL); 3325 } 3326 3327 static int fake_filldir(void *buf, const char *name, int namelen, 3328 loff_t offset, u64 ino, unsigned d_type) 3329 { 3330 return 0; 3331 } 3332 3333 /* for the /proc/ directory itself, after non-process stuff has been done */ 3334 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 3335 { 3336 unsigned int nr; 3337 struct task_struct *reaper; 3338 struct tgid_iter iter; 3339 struct pid_namespace *ns; 3340 filldir_t __filldir; 3341 3342 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET) 3343 goto out_no_task; 3344 nr = filp->f_pos - FIRST_PROCESS_ENTRY; 3345 3346 reaper = get_proc_task(filp->f_path.dentry->d_inode); 3347 if (!reaper) 3348 goto out_no_task; 3349 3350 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 3351 const struct pid_entry *p = &proc_base_stuff[nr]; 3352 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 3353 goto out; 3354 } 3355 3356 ns = filp->f_dentry->d_sb->s_fs_info; 3357 iter.task = NULL; 3358 iter.tgid = filp->f_pos - TGID_OFFSET; 3359 for (iter = next_tgid(ns, iter); 3360 iter.task; 3361 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3362 if (has_pid_permissions(ns, iter.task, 2)) 3363 __filldir = filldir; 3364 else 3365 __filldir = fake_filldir; 3366 3367 filp->f_pos = iter.tgid + TGID_OFFSET; 3368 if (proc_pid_fill_cache(filp, dirent, __filldir, iter) < 0) { 3369 put_task_struct(iter.task); 3370 goto out; 3371 } 3372 } 3373 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 3374 out: 3375 put_task_struct(reaper); 3376 out_no_task: 3377 return 0; 3378 } 3379 3380 /* 3381 * Tasks 3382 */ 3383 static const struct pid_entry tid_base_stuff[] = { 3384 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3385 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3386 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3387 REG("environ", S_IRUSR, proc_environ_operations), 3388 INF("auxv", S_IRUSR, proc_pid_auxv), 3389 ONE("status", S_IRUGO, proc_pid_status), 3390 ONE("personality", S_IRUGO, proc_pid_personality), 3391 INF("limits", S_IRUGO, proc_pid_limits), 3392 #ifdef CONFIG_SCHED_DEBUG 3393 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3394 #endif 3395 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3396 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3397 INF("syscall", S_IRUGO, proc_pid_syscall), 3398 #endif 3399 INF("cmdline", S_IRUGO, proc_pid_cmdline), 3400 ONE("stat", S_IRUGO, proc_tid_stat), 3401 ONE("statm", S_IRUGO, proc_pid_statm), 3402 REG("maps", S_IRUGO, proc_tid_maps_operations), 3403 #ifdef CONFIG_CHECKPOINT_RESTORE 3404 REG("children", S_IRUGO, proc_tid_children_operations), 3405 #endif 3406 #ifdef CONFIG_NUMA 3407 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations), 3408 #endif 3409 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3410 LNK("cwd", proc_cwd_link), 3411 LNK("root", proc_root_link), 3412 LNK("exe", proc_exe_link), 3413 REG("mounts", S_IRUGO, proc_mounts_operations), 3414 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3415 #ifdef CONFIG_PROC_PAGE_MONITOR 3416 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3417 REG("smaps", S_IRUGO, proc_tid_smaps_operations), 3418 REG("pagemap", S_IRUGO, proc_pagemap_operations), 3419 #endif 3420 #ifdef CONFIG_SECURITY 3421 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3422 #endif 3423 #ifdef CONFIG_KALLSYMS 3424 INF("wchan", S_IRUGO, proc_pid_wchan), 3425 #endif 3426 #ifdef CONFIG_STACKTRACE 3427 ONE("stack", S_IRUGO, proc_pid_stack), 3428 #endif 3429 #ifdef CONFIG_SCHEDSTATS 3430 INF("schedstat", S_IRUGO, proc_pid_schedstat), 3431 #endif 3432 #ifdef CONFIG_LATENCYTOP 3433 REG("latency", S_IRUGO, proc_lstats_operations), 3434 #endif 3435 #ifdef CONFIG_PROC_PID_CPUSET 3436 REG("cpuset", S_IRUGO, proc_cpuset_operations), 3437 #endif 3438 #ifdef CONFIG_CGROUPS 3439 REG("cgroup", S_IRUGO, proc_cgroup_operations), 3440 #endif 3441 INF("oom_score", S_IRUGO, proc_oom_score), 3442 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 3443 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3444 #ifdef CONFIG_AUDITSYSCALL 3445 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3446 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3447 #endif 3448 #ifdef CONFIG_FAULT_INJECTION 3449 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3450 #endif 3451 #ifdef CONFIG_TASK_IO_ACCOUNTING 3452 INF("io", S_IRUSR, proc_tid_io_accounting), 3453 #endif 3454 #ifdef CONFIG_HARDWALL 3455 INF("hardwall", S_IRUGO, proc_pid_hardwall), 3456 #endif 3457 #ifdef CONFIG_USER_NS 3458 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3459 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3460 #endif 3461 }; 3462 3463 static int proc_tid_base_readdir(struct file * filp, 3464 void * dirent, filldir_t filldir) 3465 { 3466 return proc_pident_readdir(filp,dirent,filldir, 3467 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 3468 } 3469 3470 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 3471 return proc_pident_lookup(dir, dentry, 3472 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3473 } 3474 3475 static const struct file_operations proc_tid_base_operations = { 3476 .read = generic_read_dir, 3477 .readdir = proc_tid_base_readdir, 3478 .llseek = default_llseek, 3479 }; 3480 3481 static const struct inode_operations proc_tid_base_inode_operations = { 3482 .lookup = proc_tid_base_lookup, 3483 .getattr = pid_getattr, 3484 .setattr = proc_setattr, 3485 }; 3486 3487 static struct dentry *proc_task_instantiate(struct inode *dir, 3488 struct dentry *dentry, struct task_struct *task, const void *ptr) 3489 { 3490 struct dentry *error = ERR_PTR(-ENOENT); 3491 struct inode *inode; 3492 inode = proc_pid_make_inode(dir->i_sb, task); 3493 3494 if (!inode) 3495 goto out; 3496 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3497 inode->i_op = &proc_tid_base_inode_operations; 3498 inode->i_fop = &proc_tid_base_operations; 3499 inode->i_flags|=S_IMMUTABLE; 3500 3501 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff, 3502 ARRAY_SIZE(tid_base_stuff))); 3503 3504 d_set_d_op(dentry, &pid_dentry_operations); 3505 3506 d_add(dentry, inode); 3507 /* Close the race of the process dying before we return the dentry */ 3508 if (pid_revalidate(dentry, NULL)) 3509 error = NULL; 3510 out: 3511 return error; 3512 } 3513 3514 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 3515 { 3516 struct dentry *result = ERR_PTR(-ENOENT); 3517 struct task_struct *task; 3518 struct task_struct *leader = get_proc_task(dir); 3519 unsigned tid; 3520 struct pid_namespace *ns; 3521 3522 if (!leader) 3523 goto out_no_task; 3524 3525 tid = name_to_int(dentry); 3526 if (tid == ~0U) 3527 goto out; 3528 3529 ns = dentry->d_sb->s_fs_info; 3530 rcu_read_lock(); 3531 task = find_task_by_pid_ns(tid, ns); 3532 if (task) 3533 get_task_struct(task); 3534 rcu_read_unlock(); 3535 if (!task) 3536 goto out; 3537 if (!same_thread_group(leader, task)) 3538 goto out_drop_task; 3539 3540 result = proc_task_instantiate(dir, dentry, task, NULL); 3541 out_drop_task: 3542 put_task_struct(task); 3543 out: 3544 put_task_struct(leader); 3545 out_no_task: 3546 return result; 3547 } 3548 3549 /* 3550 * Find the first tid of a thread group to return to user space. 3551 * 3552 * Usually this is just the thread group leader, but if the users 3553 * buffer was too small or there was a seek into the middle of the 3554 * directory we have more work todo. 3555 * 3556 * In the case of a short read we start with find_task_by_pid. 3557 * 3558 * In the case of a seek we start with the leader and walk nr 3559 * threads past it. 3560 */ 3561 static struct task_struct *first_tid(struct task_struct *leader, 3562 int tid, int nr, struct pid_namespace *ns) 3563 { 3564 struct task_struct *pos; 3565 3566 rcu_read_lock(); 3567 /* Attempt to start with the pid of a thread */ 3568 if (tid && (nr > 0)) { 3569 pos = find_task_by_pid_ns(tid, ns); 3570 if (pos && (pos->group_leader == leader)) 3571 goto found; 3572 } 3573 3574 /* If nr exceeds the number of threads there is nothing todo */ 3575 pos = NULL; 3576 if (nr && nr >= get_nr_threads(leader)) 3577 goto out; 3578 3579 /* If we haven't found our starting place yet start 3580 * with the leader and walk nr threads forward. 3581 */ 3582 for (pos = leader; nr > 0; --nr) { 3583 pos = next_thread(pos); 3584 if (pos == leader) { 3585 pos = NULL; 3586 goto out; 3587 } 3588 } 3589 found: 3590 get_task_struct(pos); 3591 out: 3592 rcu_read_unlock(); 3593 return pos; 3594 } 3595 3596 /* 3597 * Find the next thread in the thread list. 3598 * Return NULL if there is an error or no next thread. 3599 * 3600 * The reference to the input task_struct is released. 3601 */ 3602 static struct task_struct *next_tid(struct task_struct *start) 3603 { 3604 struct task_struct *pos = NULL; 3605 rcu_read_lock(); 3606 if (pid_alive(start)) { 3607 pos = next_thread(start); 3608 if (thread_group_leader(pos)) 3609 pos = NULL; 3610 else 3611 get_task_struct(pos); 3612 } 3613 rcu_read_unlock(); 3614 put_task_struct(start); 3615 return pos; 3616 } 3617 3618 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3619 struct task_struct *task, int tid) 3620 { 3621 char name[PROC_NUMBUF]; 3622 int len = snprintf(name, sizeof(name), "%d", tid); 3623 return proc_fill_cache(filp, dirent, filldir, name, len, 3624 proc_task_instantiate, task, NULL); 3625 } 3626 3627 /* for the /proc/TGID/task/ directories */ 3628 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 3629 { 3630 struct dentry *dentry = filp->f_path.dentry; 3631 struct inode *inode = dentry->d_inode; 3632 struct task_struct *leader = NULL; 3633 struct task_struct *task; 3634 int retval = -ENOENT; 3635 ino_t ino; 3636 int tid; 3637 struct pid_namespace *ns; 3638 3639 task = get_proc_task(inode); 3640 if (!task) 3641 goto out_no_task; 3642 rcu_read_lock(); 3643 if (pid_alive(task)) { 3644 leader = task->group_leader; 3645 get_task_struct(leader); 3646 } 3647 rcu_read_unlock(); 3648 put_task_struct(task); 3649 if (!leader) 3650 goto out_no_task; 3651 retval = 0; 3652 3653 switch ((unsigned long)filp->f_pos) { 3654 case 0: 3655 ino = inode->i_ino; 3656 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0) 3657 goto out; 3658 filp->f_pos++; 3659 /* fall through */ 3660 case 1: 3661 ino = parent_ino(dentry); 3662 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0) 3663 goto out; 3664 filp->f_pos++; 3665 /* fall through */ 3666 } 3667 3668 /* f_version caches the tgid value that the last readdir call couldn't 3669 * return. lseek aka telldir automagically resets f_version to 0. 3670 */ 3671 ns = filp->f_dentry->d_sb->s_fs_info; 3672 tid = (int)filp->f_version; 3673 filp->f_version = 0; 3674 for (task = first_tid(leader, tid, filp->f_pos - 2, ns); 3675 task; 3676 task = next_tid(task), filp->f_pos++) { 3677 tid = task_pid_nr_ns(task, ns); 3678 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 3679 /* returning this tgid failed, save it as the first 3680 * pid for the next readir call */ 3681 filp->f_version = (u64)tid; 3682 put_task_struct(task); 3683 break; 3684 } 3685 } 3686 out: 3687 put_task_struct(leader); 3688 out_no_task: 3689 return retval; 3690 } 3691 3692 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3693 { 3694 struct inode *inode = dentry->d_inode; 3695 struct task_struct *p = get_proc_task(inode); 3696 generic_fillattr(inode, stat); 3697 3698 if (p) { 3699 stat->nlink += get_nr_threads(p); 3700 put_task_struct(p); 3701 } 3702 3703 return 0; 3704 } 3705 3706 static const struct inode_operations proc_task_inode_operations = { 3707 .lookup = proc_task_lookup, 3708 .getattr = proc_task_getattr, 3709 .setattr = proc_setattr, 3710 .permission = proc_pid_permission, 3711 }; 3712 3713 static const struct file_operations proc_task_operations = { 3714 .read = generic_read_dir, 3715 .readdir = proc_task_readdir, 3716 .llseek = default_llseek, 3717 }; 3718