1 /* 2 * linux/fs/proc/base.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 * 6 * proc base directory handling functions 7 * 8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part. 9 * Instead of using magical inumbers to determine the kind of object 10 * we allocate and fill in-core inodes upon lookup. They don't even 11 * go into icache. We cache the reference to task_struct upon lookup too. 12 * Eventually it should become a filesystem in its own. We don't use the 13 * rest of procfs anymore. 14 * 15 * 16 * Changelog: 17 * 17-Jan-2005 18 * Allan Bezerra 19 * Bruna Moreira <bruna.moreira@indt.org.br> 20 * Edjard Mota <edjard.mota@indt.org.br> 21 * Ilias Biris <ilias.biris@indt.org.br> 22 * Mauricio Lin <mauricio.lin@indt.org.br> 23 * 24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 25 * 26 * A new process specific entry (smaps) included in /proc. It shows the 27 * size of rss for each memory area. The maps entry lacks information 28 * about physical memory size (rss) for each mapped file, i.e., 29 * rss information for executables and library files. 30 * This additional information is useful for any tools that need to know 31 * about physical memory consumption for a process specific library. 32 * 33 * Changelog: 34 * 21-Feb-2005 35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 36 * Pud inclusion in the page table walking. 37 * 38 * ChangeLog: 39 * 10-Mar-2005 40 * 10LE Instituto Nokia de Tecnologia - INdT: 41 * A better way to walks through the page table as suggested by Hugh Dickins. 42 * 43 * Simo Piiroinen <simo.piiroinen@nokia.com>: 44 * Smaps information related to shared, private, clean and dirty pages. 45 * 46 * Paul Mundt <paul.mundt@nokia.com>: 47 * Overall revision about smaps. 48 */ 49 50 #include <asm/uaccess.h> 51 52 #include <linux/errno.h> 53 #include <linux/time.h> 54 #include <linux/proc_fs.h> 55 #include <linux/stat.h> 56 #include <linux/task_io_accounting_ops.h> 57 #include <linux/init.h> 58 #include <linux/capability.h> 59 #include <linux/file.h> 60 #include <linux/fdtable.h> 61 #include <linux/string.h> 62 #include <linux/seq_file.h> 63 #include <linux/namei.h> 64 #include <linux/mnt_namespace.h> 65 #include <linux/mm.h> 66 #include <linux/swap.h> 67 #include <linux/rcupdate.h> 68 #include <linux/kallsyms.h> 69 #include <linux/stacktrace.h> 70 #include <linux/resource.h> 71 #include <linux/module.h> 72 #include <linux/mount.h> 73 #include <linux/security.h> 74 #include <linux/ptrace.h> 75 #include <linux/tracehook.h> 76 #include <linux/cgroup.h> 77 #include <linux/cpuset.h> 78 #include <linux/audit.h> 79 #include <linux/poll.h> 80 #include <linux/nsproxy.h> 81 #include <linux/oom.h> 82 #include <linux/elf.h> 83 #include <linux/pid_namespace.h> 84 #include <linux/fs_struct.h> 85 #include <linux/slab.h> 86 #ifdef CONFIG_HARDWALL 87 #include <asm/hardwall.h> 88 #endif 89 #include "internal.h" 90 91 /* NOTE: 92 * Implementing inode permission operations in /proc is almost 93 * certainly an error. Permission checks need to happen during 94 * each system call not at open time. The reason is that most of 95 * what we wish to check for permissions in /proc varies at runtime. 96 * 97 * The classic example of a problem is opening file descriptors 98 * in /proc for a task before it execs a suid executable. 99 */ 100 101 struct pid_entry { 102 char *name; 103 int len; 104 mode_t mode; 105 const struct inode_operations *iop; 106 const struct file_operations *fop; 107 union proc_op op; 108 }; 109 110 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 111 .name = (NAME), \ 112 .len = sizeof(NAME) - 1, \ 113 .mode = MODE, \ 114 .iop = IOP, \ 115 .fop = FOP, \ 116 .op = OP, \ 117 } 118 119 #define DIR(NAME, MODE, iops, fops) \ 120 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} ) 121 #define LNK(NAME, get_link) \ 122 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 123 &proc_pid_link_inode_operations, NULL, \ 124 { .proc_get_link = get_link } ) 125 #define REG(NAME, MODE, fops) \ 126 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {}) 127 #define INF(NAME, MODE, read) \ 128 NOD(NAME, (S_IFREG|(MODE)), \ 129 NULL, &proc_info_file_operations, \ 130 { .proc_read = read } ) 131 #define ONE(NAME, MODE, show) \ 132 NOD(NAME, (S_IFREG|(MODE)), \ 133 NULL, &proc_single_file_operations, \ 134 { .proc_show = show } ) 135 136 /* 137 * Count the number of hardlinks for the pid_entry table, excluding the . 138 * and .. links. 139 */ 140 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries, 141 unsigned int n) 142 { 143 unsigned int i; 144 unsigned int count; 145 146 count = 0; 147 for (i = 0; i < n; ++i) { 148 if (S_ISDIR(entries[i].mode)) 149 ++count; 150 } 151 152 return count; 153 } 154 155 static int get_task_root(struct task_struct *task, struct path *root) 156 { 157 int result = -ENOENT; 158 159 task_lock(task); 160 if (task->fs) { 161 get_fs_root(task->fs, root); 162 result = 0; 163 } 164 task_unlock(task); 165 return result; 166 } 167 168 static int proc_cwd_link(struct inode *inode, struct path *path) 169 { 170 struct task_struct *task = get_proc_task(inode); 171 int result = -ENOENT; 172 173 if (task) { 174 task_lock(task); 175 if (task->fs) { 176 get_fs_pwd(task->fs, path); 177 result = 0; 178 } 179 task_unlock(task); 180 put_task_struct(task); 181 } 182 return result; 183 } 184 185 static int proc_root_link(struct inode *inode, struct path *path) 186 { 187 struct task_struct *task = get_proc_task(inode); 188 int result = -ENOENT; 189 190 if (task) { 191 result = get_task_root(task, path); 192 put_task_struct(task); 193 } 194 return result; 195 } 196 197 static struct mm_struct *__check_mem_permission(struct task_struct *task) 198 { 199 struct mm_struct *mm; 200 201 mm = get_task_mm(task); 202 if (!mm) 203 return ERR_PTR(-EINVAL); 204 205 /* 206 * A task can always look at itself, in case it chooses 207 * to use system calls instead of load instructions. 208 */ 209 if (task == current) 210 return mm; 211 212 /* 213 * If current is actively ptrace'ing, and would also be 214 * permitted to freshly attach with ptrace now, permit it. 215 */ 216 if (task_is_stopped_or_traced(task)) { 217 int match; 218 rcu_read_lock(); 219 match = (ptrace_parent(task) == current); 220 rcu_read_unlock(); 221 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH)) 222 return mm; 223 } 224 225 /* 226 * No one else is allowed. 227 */ 228 mmput(mm); 229 return ERR_PTR(-EPERM); 230 } 231 232 /* 233 * If current may access user memory in @task return a reference to the 234 * corresponding mm, otherwise ERR_PTR. 235 */ 236 static struct mm_struct *check_mem_permission(struct task_struct *task) 237 { 238 struct mm_struct *mm; 239 int err; 240 241 /* 242 * Avoid racing if task exec's as we might get a new mm but validate 243 * against old credentials. 244 */ 245 err = mutex_lock_killable(&task->signal->cred_guard_mutex); 246 if (err) 247 return ERR_PTR(err); 248 249 mm = __check_mem_permission(task); 250 mutex_unlock(&task->signal->cred_guard_mutex); 251 252 return mm; 253 } 254 255 struct mm_struct *mm_for_maps(struct task_struct *task) 256 { 257 struct mm_struct *mm; 258 int err; 259 260 err = mutex_lock_killable(&task->signal->cred_guard_mutex); 261 if (err) 262 return ERR_PTR(err); 263 264 mm = get_task_mm(task); 265 if (mm && mm != current->mm && 266 !ptrace_may_access(task, PTRACE_MODE_READ)) { 267 mmput(mm); 268 mm = ERR_PTR(-EACCES); 269 } 270 mutex_unlock(&task->signal->cred_guard_mutex); 271 272 return mm; 273 } 274 275 static int proc_pid_cmdline(struct task_struct *task, char * buffer) 276 { 277 int res = 0; 278 unsigned int len; 279 struct mm_struct *mm = get_task_mm(task); 280 if (!mm) 281 goto out; 282 if (!mm->arg_end) 283 goto out_mm; /* Shh! No looking before we're done */ 284 285 len = mm->arg_end - mm->arg_start; 286 287 if (len > PAGE_SIZE) 288 len = PAGE_SIZE; 289 290 res = access_process_vm(task, mm->arg_start, buffer, len, 0); 291 292 // If the nul at the end of args has been overwritten, then 293 // assume application is using setproctitle(3). 294 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) { 295 len = strnlen(buffer, res); 296 if (len < res) { 297 res = len; 298 } else { 299 len = mm->env_end - mm->env_start; 300 if (len > PAGE_SIZE - res) 301 len = PAGE_SIZE - res; 302 res += access_process_vm(task, mm->env_start, buffer+res, len, 0); 303 res = strnlen(buffer, res); 304 } 305 } 306 out_mm: 307 mmput(mm); 308 out: 309 return res; 310 } 311 312 static int proc_pid_auxv(struct task_struct *task, char *buffer) 313 { 314 struct mm_struct *mm = mm_for_maps(task); 315 int res = PTR_ERR(mm); 316 if (mm && !IS_ERR(mm)) { 317 unsigned int nwords = 0; 318 do { 319 nwords += 2; 320 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 321 res = nwords * sizeof(mm->saved_auxv[0]); 322 if (res > PAGE_SIZE) 323 res = PAGE_SIZE; 324 memcpy(buffer, mm->saved_auxv, res); 325 mmput(mm); 326 } 327 return res; 328 } 329 330 331 #ifdef CONFIG_KALLSYMS 332 /* 333 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 334 * Returns the resolved symbol. If that fails, simply return the address. 335 */ 336 static int proc_pid_wchan(struct task_struct *task, char *buffer) 337 { 338 unsigned long wchan; 339 char symname[KSYM_NAME_LEN]; 340 341 wchan = get_wchan(task); 342 343 if (lookup_symbol_name(wchan, symname) < 0) 344 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 345 return 0; 346 else 347 return sprintf(buffer, "%lu", wchan); 348 else 349 return sprintf(buffer, "%s", symname); 350 } 351 #endif /* CONFIG_KALLSYMS */ 352 353 static int lock_trace(struct task_struct *task) 354 { 355 int err = mutex_lock_killable(&task->signal->cred_guard_mutex); 356 if (err) 357 return err; 358 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) { 359 mutex_unlock(&task->signal->cred_guard_mutex); 360 return -EPERM; 361 } 362 return 0; 363 } 364 365 static void unlock_trace(struct task_struct *task) 366 { 367 mutex_unlock(&task->signal->cred_guard_mutex); 368 } 369 370 #ifdef CONFIG_STACKTRACE 371 372 #define MAX_STACK_TRACE_DEPTH 64 373 374 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, 375 struct pid *pid, struct task_struct *task) 376 { 377 struct stack_trace trace; 378 unsigned long *entries; 379 int err; 380 int i; 381 382 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL); 383 if (!entries) 384 return -ENOMEM; 385 386 trace.nr_entries = 0; 387 trace.max_entries = MAX_STACK_TRACE_DEPTH; 388 trace.entries = entries; 389 trace.skip = 0; 390 391 err = lock_trace(task); 392 if (!err) { 393 save_stack_trace_tsk(task, &trace); 394 395 for (i = 0; i < trace.nr_entries; i++) { 396 seq_printf(m, "[<%pK>] %pS\n", 397 (void *)entries[i], (void *)entries[i]); 398 } 399 unlock_trace(task); 400 } 401 kfree(entries); 402 403 return err; 404 } 405 #endif 406 407 #ifdef CONFIG_SCHEDSTATS 408 /* 409 * Provides /proc/PID/schedstat 410 */ 411 static int proc_pid_schedstat(struct task_struct *task, char *buffer) 412 { 413 return sprintf(buffer, "%llu %llu %lu\n", 414 (unsigned long long)task->se.sum_exec_runtime, 415 (unsigned long long)task->sched_info.run_delay, 416 task->sched_info.pcount); 417 } 418 #endif 419 420 #ifdef CONFIG_LATENCYTOP 421 static int lstats_show_proc(struct seq_file *m, void *v) 422 { 423 int i; 424 struct inode *inode = m->private; 425 struct task_struct *task = get_proc_task(inode); 426 427 if (!task) 428 return -ESRCH; 429 seq_puts(m, "Latency Top version : v0.1\n"); 430 for (i = 0; i < 32; i++) { 431 struct latency_record *lr = &task->latency_record[i]; 432 if (lr->backtrace[0]) { 433 int q; 434 seq_printf(m, "%i %li %li", 435 lr->count, lr->time, lr->max); 436 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 437 unsigned long bt = lr->backtrace[q]; 438 if (!bt) 439 break; 440 if (bt == ULONG_MAX) 441 break; 442 seq_printf(m, " %ps", (void *)bt); 443 } 444 seq_putc(m, '\n'); 445 } 446 447 } 448 put_task_struct(task); 449 return 0; 450 } 451 452 static int lstats_open(struct inode *inode, struct file *file) 453 { 454 return single_open(file, lstats_show_proc, inode); 455 } 456 457 static ssize_t lstats_write(struct file *file, const char __user *buf, 458 size_t count, loff_t *offs) 459 { 460 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 461 462 if (!task) 463 return -ESRCH; 464 clear_all_latency_tracing(task); 465 put_task_struct(task); 466 467 return count; 468 } 469 470 static const struct file_operations proc_lstats_operations = { 471 .open = lstats_open, 472 .read = seq_read, 473 .write = lstats_write, 474 .llseek = seq_lseek, 475 .release = single_release, 476 }; 477 478 #endif 479 480 static int proc_oom_score(struct task_struct *task, char *buffer) 481 { 482 unsigned long points = 0; 483 484 read_lock(&tasklist_lock); 485 if (pid_alive(task)) 486 points = oom_badness(task, NULL, NULL, 487 totalram_pages + total_swap_pages); 488 read_unlock(&tasklist_lock); 489 return sprintf(buffer, "%lu\n", points); 490 } 491 492 struct limit_names { 493 char *name; 494 char *unit; 495 }; 496 497 static const struct limit_names lnames[RLIM_NLIMITS] = { 498 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 499 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 500 [RLIMIT_DATA] = {"Max data size", "bytes"}, 501 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 502 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 503 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 504 [RLIMIT_NPROC] = {"Max processes", "processes"}, 505 [RLIMIT_NOFILE] = {"Max open files", "files"}, 506 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 507 [RLIMIT_AS] = {"Max address space", "bytes"}, 508 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 509 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 510 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 511 [RLIMIT_NICE] = {"Max nice priority", NULL}, 512 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 513 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 514 }; 515 516 /* Display limits for a process */ 517 static int proc_pid_limits(struct task_struct *task, char *buffer) 518 { 519 unsigned int i; 520 int count = 0; 521 unsigned long flags; 522 char *bufptr = buffer; 523 524 struct rlimit rlim[RLIM_NLIMITS]; 525 526 if (!lock_task_sighand(task, &flags)) 527 return 0; 528 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 529 unlock_task_sighand(task, &flags); 530 531 /* 532 * print the file header 533 */ 534 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n", 535 "Limit", "Soft Limit", "Hard Limit", "Units"); 536 537 for (i = 0; i < RLIM_NLIMITS; i++) { 538 if (rlim[i].rlim_cur == RLIM_INFINITY) 539 count += sprintf(&bufptr[count], "%-25s %-20s ", 540 lnames[i].name, "unlimited"); 541 else 542 count += sprintf(&bufptr[count], "%-25s %-20lu ", 543 lnames[i].name, rlim[i].rlim_cur); 544 545 if (rlim[i].rlim_max == RLIM_INFINITY) 546 count += sprintf(&bufptr[count], "%-20s ", "unlimited"); 547 else 548 count += sprintf(&bufptr[count], "%-20lu ", 549 rlim[i].rlim_max); 550 551 if (lnames[i].unit) 552 count += sprintf(&bufptr[count], "%-10s\n", 553 lnames[i].unit); 554 else 555 count += sprintf(&bufptr[count], "\n"); 556 } 557 558 return count; 559 } 560 561 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 562 static int proc_pid_syscall(struct task_struct *task, char *buffer) 563 { 564 long nr; 565 unsigned long args[6], sp, pc; 566 int res = lock_trace(task); 567 if (res) 568 return res; 569 570 if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) 571 res = sprintf(buffer, "running\n"); 572 else if (nr < 0) 573 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc); 574 else 575 res = sprintf(buffer, 576 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", 577 nr, 578 args[0], args[1], args[2], args[3], args[4], args[5], 579 sp, pc); 580 unlock_trace(task); 581 return res; 582 } 583 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 584 585 /************************************************************************/ 586 /* Here the fs part begins */ 587 /************************************************************************/ 588 589 /* permission checks */ 590 static int proc_fd_access_allowed(struct inode *inode) 591 { 592 struct task_struct *task; 593 int allowed = 0; 594 /* Allow access to a task's file descriptors if it is us or we 595 * may use ptrace attach to the process and find out that 596 * information. 597 */ 598 task = get_proc_task(inode); 599 if (task) { 600 allowed = ptrace_may_access(task, PTRACE_MODE_READ); 601 put_task_struct(task); 602 } 603 return allowed; 604 } 605 606 int proc_setattr(struct dentry *dentry, struct iattr *attr) 607 { 608 int error; 609 struct inode *inode = dentry->d_inode; 610 611 if (attr->ia_valid & ATTR_MODE) 612 return -EPERM; 613 614 error = inode_change_ok(inode, attr); 615 if (error) 616 return error; 617 618 if ((attr->ia_valid & ATTR_SIZE) && 619 attr->ia_size != i_size_read(inode)) { 620 error = vmtruncate(inode, attr->ia_size); 621 if (error) 622 return error; 623 } 624 625 setattr_copy(inode, attr); 626 mark_inode_dirty(inode); 627 return 0; 628 } 629 630 static const struct inode_operations proc_def_inode_operations = { 631 .setattr = proc_setattr, 632 }; 633 634 static int mounts_open_common(struct inode *inode, struct file *file, 635 const struct seq_operations *op) 636 { 637 struct task_struct *task = get_proc_task(inode); 638 struct nsproxy *nsp; 639 struct mnt_namespace *ns = NULL; 640 struct path root; 641 struct proc_mounts *p; 642 int ret = -EINVAL; 643 644 if (task) { 645 rcu_read_lock(); 646 nsp = task_nsproxy(task); 647 if (nsp) { 648 ns = nsp->mnt_ns; 649 if (ns) 650 get_mnt_ns(ns); 651 } 652 rcu_read_unlock(); 653 if (ns && get_task_root(task, &root) == 0) 654 ret = 0; 655 put_task_struct(task); 656 } 657 658 if (!ns) 659 goto err; 660 if (ret) 661 goto err_put_ns; 662 663 ret = -ENOMEM; 664 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL); 665 if (!p) 666 goto err_put_path; 667 668 file->private_data = &p->m; 669 ret = seq_open(file, op); 670 if (ret) 671 goto err_free; 672 673 p->m.private = p; 674 p->ns = ns; 675 p->root = root; 676 p->m.poll_event = ns->event; 677 678 return 0; 679 680 err_free: 681 kfree(p); 682 err_put_path: 683 path_put(&root); 684 err_put_ns: 685 put_mnt_ns(ns); 686 err: 687 return ret; 688 } 689 690 static int mounts_release(struct inode *inode, struct file *file) 691 { 692 struct proc_mounts *p = file->private_data; 693 path_put(&p->root); 694 put_mnt_ns(p->ns); 695 return seq_release(inode, file); 696 } 697 698 static unsigned mounts_poll(struct file *file, poll_table *wait) 699 { 700 struct proc_mounts *p = file->private_data; 701 unsigned res = POLLIN | POLLRDNORM; 702 703 poll_wait(file, &p->ns->poll, wait); 704 if (mnt_had_events(p)) 705 res |= POLLERR | POLLPRI; 706 707 return res; 708 } 709 710 static int mounts_open(struct inode *inode, struct file *file) 711 { 712 return mounts_open_common(inode, file, &mounts_op); 713 } 714 715 static const struct file_operations proc_mounts_operations = { 716 .open = mounts_open, 717 .read = seq_read, 718 .llseek = seq_lseek, 719 .release = mounts_release, 720 .poll = mounts_poll, 721 }; 722 723 static int mountinfo_open(struct inode *inode, struct file *file) 724 { 725 return mounts_open_common(inode, file, &mountinfo_op); 726 } 727 728 static const struct file_operations proc_mountinfo_operations = { 729 .open = mountinfo_open, 730 .read = seq_read, 731 .llseek = seq_lseek, 732 .release = mounts_release, 733 .poll = mounts_poll, 734 }; 735 736 static int mountstats_open(struct inode *inode, struct file *file) 737 { 738 return mounts_open_common(inode, file, &mountstats_op); 739 } 740 741 static const struct file_operations proc_mountstats_operations = { 742 .open = mountstats_open, 743 .read = seq_read, 744 .llseek = seq_lseek, 745 .release = mounts_release, 746 }; 747 748 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */ 749 750 static ssize_t proc_info_read(struct file * file, char __user * buf, 751 size_t count, loff_t *ppos) 752 { 753 struct inode * inode = file->f_path.dentry->d_inode; 754 unsigned long page; 755 ssize_t length; 756 struct task_struct *task = get_proc_task(inode); 757 758 length = -ESRCH; 759 if (!task) 760 goto out_no_task; 761 762 if (count > PROC_BLOCK_SIZE) 763 count = PROC_BLOCK_SIZE; 764 765 length = -ENOMEM; 766 if (!(page = __get_free_page(GFP_TEMPORARY))) 767 goto out; 768 769 length = PROC_I(inode)->op.proc_read(task, (char*)page); 770 771 if (length >= 0) 772 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length); 773 free_page(page); 774 out: 775 put_task_struct(task); 776 out_no_task: 777 return length; 778 } 779 780 static const struct file_operations proc_info_file_operations = { 781 .read = proc_info_read, 782 .llseek = generic_file_llseek, 783 }; 784 785 static int proc_single_show(struct seq_file *m, void *v) 786 { 787 struct inode *inode = m->private; 788 struct pid_namespace *ns; 789 struct pid *pid; 790 struct task_struct *task; 791 int ret; 792 793 ns = inode->i_sb->s_fs_info; 794 pid = proc_pid(inode); 795 task = get_pid_task(pid, PIDTYPE_PID); 796 if (!task) 797 return -ESRCH; 798 799 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 800 801 put_task_struct(task); 802 return ret; 803 } 804 805 static int proc_single_open(struct inode *inode, struct file *filp) 806 { 807 return single_open(filp, proc_single_show, inode); 808 } 809 810 static const struct file_operations proc_single_file_operations = { 811 .open = proc_single_open, 812 .read = seq_read, 813 .llseek = seq_lseek, 814 .release = single_release, 815 }; 816 817 static int mem_open(struct inode* inode, struct file* file) 818 { 819 file->private_data = (void*)((long)current->self_exec_id); 820 /* OK to pass negative loff_t, we can catch out-of-range */ 821 file->f_mode |= FMODE_UNSIGNED_OFFSET; 822 return 0; 823 } 824 825 static ssize_t mem_read(struct file * file, char __user * buf, 826 size_t count, loff_t *ppos) 827 { 828 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 829 char *page; 830 unsigned long src = *ppos; 831 int ret = -ESRCH; 832 struct mm_struct *mm; 833 834 if (!task) 835 goto out_no_task; 836 837 ret = -ENOMEM; 838 page = (char *)__get_free_page(GFP_TEMPORARY); 839 if (!page) 840 goto out; 841 842 mm = check_mem_permission(task); 843 ret = PTR_ERR(mm); 844 if (IS_ERR(mm)) 845 goto out_free; 846 847 ret = -EIO; 848 849 if (file->private_data != (void*)((long)current->self_exec_id)) 850 goto out_put; 851 852 ret = 0; 853 854 while (count > 0) { 855 int this_len, retval; 856 857 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 858 retval = access_remote_vm(mm, src, page, this_len, 0); 859 if (!retval) { 860 if (!ret) 861 ret = -EIO; 862 break; 863 } 864 865 if (copy_to_user(buf, page, retval)) { 866 ret = -EFAULT; 867 break; 868 } 869 870 ret += retval; 871 src += retval; 872 buf += retval; 873 count -= retval; 874 } 875 *ppos = src; 876 877 out_put: 878 mmput(mm); 879 out_free: 880 free_page((unsigned long) page); 881 out: 882 put_task_struct(task); 883 out_no_task: 884 return ret; 885 } 886 887 static ssize_t mem_write(struct file * file, const char __user *buf, 888 size_t count, loff_t *ppos) 889 { 890 int copied; 891 char *page; 892 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 893 unsigned long dst = *ppos; 894 struct mm_struct *mm; 895 896 copied = -ESRCH; 897 if (!task) 898 goto out_no_task; 899 900 copied = -ENOMEM; 901 page = (char *)__get_free_page(GFP_TEMPORARY); 902 if (!page) 903 goto out_task; 904 905 mm = check_mem_permission(task); 906 copied = PTR_ERR(mm); 907 if (IS_ERR(mm)) 908 goto out_free; 909 910 copied = -EIO; 911 if (file->private_data != (void *)((long)current->self_exec_id)) 912 goto out_mm; 913 914 copied = 0; 915 while (count > 0) { 916 int this_len, retval; 917 918 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 919 if (copy_from_user(page, buf, this_len)) { 920 copied = -EFAULT; 921 break; 922 } 923 retval = access_remote_vm(mm, dst, page, this_len, 1); 924 if (!retval) { 925 if (!copied) 926 copied = -EIO; 927 break; 928 } 929 copied += retval; 930 buf += retval; 931 dst += retval; 932 count -= retval; 933 } 934 *ppos = dst; 935 936 out_mm: 937 mmput(mm); 938 out_free: 939 free_page((unsigned long) page); 940 out_task: 941 put_task_struct(task); 942 out_no_task: 943 return copied; 944 } 945 946 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 947 { 948 switch (orig) { 949 case 0: 950 file->f_pos = offset; 951 break; 952 case 1: 953 file->f_pos += offset; 954 break; 955 default: 956 return -EINVAL; 957 } 958 force_successful_syscall_return(); 959 return file->f_pos; 960 } 961 962 static const struct file_operations proc_mem_operations = { 963 .llseek = mem_lseek, 964 .read = mem_read, 965 .write = mem_write, 966 .open = mem_open, 967 }; 968 969 static ssize_t environ_read(struct file *file, char __user *buf, 970 size_t count, loff_t *ppos) 971 { 972 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 973 char *page; 974 unsigned long src = *ppos; 975 int ret = -ESRCH; 976 struct mm_struct *mm; 977 978 if (!task) 979 goto out_no_task; 980 981 ret = -ENOMEM; 982 page = (char *)__get_free_page(GFP_TEMPORARY); 983 if (!page) 984 goto out; 985 986 987 mm = mm_for_maps(task); 988 ret = PTR_ERR(mm); 989 if (!mm || IS_ERR(mm)) 990 goto out_free; 991 992 ret = 0; 993 while (count > 0) { 994 int this_len, retval, max_len; 995 996 this_len = mm->env_end - (mm->env_start + src); 997 998 if (this_len <= 0) 999 break; 1000 1001 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 1002 this_len = (this_len > max_len) ? max_len : this_len; 1003 1004 retval = access_process_vm(task, (mm->env_start + src), 1005 page, this_len, 0); 1006 1007 if (retval <= 0) { 1008 ret = retval; 1009 break; 1010 } 1011 1012 if (copy_to_user(buf, page, retval)) { 1013 ret = -EFAULT; 1014 break; 1015 } 1016 1017 ret += retval; 1018 src += retval; 1019 buf += retval; 1020 count -= retval; 1021 } 1022 *ppos = src; 1023 1024 mmput(mm); 1025 out_free: 1026 free_page((unsigned long) page); 1027 out: 1028 put_task_struct(task); 1029 out_no_task: 1030 return ret; 1031 } 1032 1033 static const struct file_operations proc_environ_operations = { 1034 .read = environ_read, 1035 .llseek = generic_file_llseek, 1036 }; 1037 1038 static ssize_t oom_adjust_read(struct file *file, char __user *buf, 1039 size_t count, loff_t *ppos) 1040 { 1041 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 1042 char buffer[PROC_NUMBUF]; 1043 size_t len; 1044 int oom_adjust = OOM_DISABLE; 1045 unsigned long flags; 1046 1047 if (!task) 1048 return -ESRCH; 1049 1050 if (lock_task_sighand(task, &flags)) { 1051 oom_adjust = task->signal->oom_adj; 1052 unlock_task_sighand(task, &flags); 1053 } 1054 1055 put_task_struct(task); 1056 1057 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); 1058 1059 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1060 } 1061 1062 static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 1063 size_t count, loff_t *ppos) 1064 { 1065 struct task_struct *task; 1066 char buffer[PROC_NUMBUF]; 1067 int oom_adjust; 1068 unsigned long flags; 1069 int err; 1070 1071 memset(buffer, 0, sizeof(buffer)); 1072 if (count > sizeof(buffer) - 1) 1073 count = sizeof(buffer) - 1; 1074 if (copy_from_user(buffer, buf, count)) { 1075 err = -EFAULT; 1076 goto out; 1077 } 1078 1079 err = kstrtoint(strstrip(buffer), 0, &oom_adjust); 1080 if (err) 1081 goto out; 1082 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && 1083 oom_adjust != OOM_DISABLE) { 1084 err = -EINVAL; 1085 goto out; 1086 } 1087 1088 task = get_proc_task(file->f_path.dentry->d_inode); 1089 if (!task) { 1090 err = -ESRCH; 1091 goto out; 1092 } 1093 1094 task_lock(task); 1095 if (!task->mm) { 1096 err = -EINVAL; 1097 goto err_task_lock; 1098 } 1099 1100 if (!lock_task_sighand(task, &flags)) { 1101 err = -ESRCH; 1102 goto err_task_lock; 1103 } 1104 1105 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) { 1106 err = -EACCES; 1107 goto err_sighand; 1108 } 1109 1110 /* 1111 * Warn that /proc/pid/oom_adj is deprecated, see 1112 * Documentation/feature-removal-schedule.txt. 1113 */ 1114 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 1115 current->comm, task_pid_nr(current), task_pid_nr(task), 1116 task_pid_nr(task)); 1117 task->signal->oom_adj = oom_adjust; 1118 /* 1119 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 1120 * value is always attainable. 1121 */ 1122 if (task->signal->oom_adj == OOM_ADJUST_MAX) 1123 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX; 1124 else 1125 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) / 1126 -OOM_DISABLE; 1127 err_sighand: 1128 unlock_task_sighand(task, &flags); 1129 err_task_lock: 1130 task_unlock(task); 1131 put_task_struct(task); 1132 out: 1133 return err < 0 ? err : count; 1134 } 1135 1136 static const struct file_operations proc_oom_adjust_operations = { 1137 .read = oom_adjust_read, 1138 .write = oom_adjust_write, 1139 .llseek = generic_file_llseek, 1140 }; 1141 1142 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 1143 size_t count, loff_t *ppos) 1144 { 1145 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 1146 char buffer[PROC_NUMBUF]; 1147 int oom_score_adj = OOM_SCORE_ADJ_MIN; 1148 unsigned long flags; 1149 size_t len; 1150 1151 if (!task) 1152 return -ESRCH; 1153 if (lock_task_sighand(task, &flags)) { 1154 oom_score_adj = task->signal->oom_score_adj; 1155 unlock_task_sighand(task, &flags); 1156 } 1157 put_task_struct(task); 1158 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj); 1159 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1160 } 1161 1162 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1163 size_t count, loff_t *ppos) 1164 { 1165 struct task_struct *task; 1166 char buffer[PROC_NUMBUF]; 1167 unsigned long flags; 1168 int oom_score_adj; 1169 int err; 1170 1171 memset(buffer, 0, sizeof(buffer)); 1172 if (count > sizeof(buffer) - 1) 1173 count = sizeof(buffer) - 1; 1174 if (copy_from_user(buffer, buf, count)) { 1175 err = -EFAULT; 1176 goto out; 1177 } 1178 1179 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 1180 if (err) 1181 goto out; 1182 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1183 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1184 err = -EINVAL; 1185 goto out; 1186 } 1187 1188 task = get_proc_task(file->f_path.dentry->d_inode); 1189 if (!task) { 1190 err = -ESRCH; 1191 goto out; 1192 } 1193 1194 task_lock(task); 1195 if (!task->mm) { 1196 err = -EINVAL; 1197 goto err_task_lock; 1198 } 1199 1200 if (!lock_task_sighand(task, &flags)) { 1201 err = -ESRCH; 1202 goto err_task_lock; 1203 } 1204 1205 if (oom_score_adj < task->signal->oom_score_adj_min && 1206 !capable(CAP_SYS_RESOURCE)) { 1207 err = -EACCES; 1208 goto err_sighand; 1209 } 1210 1211 task->signal->oom_score_adj = oom_score_adj; 1212 if (has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1213 task->signal->oom_score_adj_min = oom_score_adj; 1214 /* 1215 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is 1216 * always attainable. 1217 */ 1218 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) 1219 task->signal->oom_adj = OOM_DISABLE; 1220 else 1221 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) / 1222 OOM_SCORE_ADJ_MAX; 1223 err_sighand: 1224 unlock_task_sighand(task, &flags); 1225 err_task_lock: 1226 task_unlock(task); 1227 put_task_struct(task); 1228 out: 1229 return err < 0 ? err : count; 1230 } 1231 1232 static const struct file_operations proc_oom_score_adj_operations = { 1233 .read = oom_score_adj_read, 1234 .write = oom_score_adj_write, 1235 .llseek = default_llseek, 1236 }; 1237 1238 #ifdef CONFIG_AUDITSYSCALL 1239 #define TMPBUFLEN 21 1240 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1241 size_t count, loff_t *ppos) 1242 { 1243 struct inode * inode = file->f_path.dentry->d_inode; 1244 struct task_struct *task = get_proc_task(inode); 1245 ssize_t length; 1246 char tmpbuf[TMPBUFLEN]; 1247 1248 if (!task) 1249 return -ESRCH; 1250 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1251 audit_get_loginuid(task)); 1252 put_task_struct(task); 1253 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1254 } 1255 1256 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1257 size_t count, loff_t *ppos) 1258 { 1259 struct inode * inode = file->f_path.dentry->d_inode; 1260 char *page, *tmp; 1261 ssize_t length; 1262 uid_t loginuid; 1263 1264 if (!capable(CAP_AUDIT_CONTROL)) 1265 return -EPERM; 1266 1267 rcu_read_lock(); 1268 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1269 rcu_read_unlock(); 1270 return -EPERM; 1271 } 1272 rcu_read_unlock(); 1273 1274 if (count >= PAGE_SIZE) 1275 count = PAGE_SIZE - 1; 1276 1277 if (*ppos != 0) { 1278 /* No partial writes. */ 1279 return -EINVAL; 1280 } 1281 page = (char*)__get_free_page(GFP_TEMPORARY); 1282 if (!page) 1283 return -ENOMEM; 1284 length = -EFAULT; 1285 if (copy_from_user(page, buf, count)) 1286 goto out_free_page; 1287 1288 page[count] = '\0'; 1289 loginuid = simple_strtoul(page, &tmp, 10); 1290 if (tmp == page) { 1291 length = -EINVAL; 1292 goto out_free_page; 1293 1294 } 1295 length = audit_set_loginuid(current, loginuid); 1296 if (likely(length == 0)) 1297 length = count; 1298 1299 out_free_page: 1300 free_page((unsigned long) page); 1301 return length; 1302 } 1303 1304 static const struct file_operations proc_loginuid_operations = { 1305 .read = proc_loginuid_read, 1306 .write = proc_loginuid_write, 1307 .llseek = generic_file_llseek, 1308 }; 1309 1310 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1311 size_t count, loff_t *ppos) 1312 { 1313 struct inode * inode = file->f_path.dentry->d_inode; 1314 struct task_struct *task = get_proc_task(inode); 1315 ssize_t length; 1316 char tmpbuf[TMPBUFLEN]; 1317 1318 if (!task) 1319 return -ESRCH; 1320 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1321 audit_get_sessionid(task)); 1322 put_task_struct(task); 1323 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1324 } 1325 1326 static const struct file_operations proc_sessionid_operations = { 1327 .read = proc_sessionid_read, 1328 .llseek = generic_file_llseek, 1329 }; 1330 #endif 1331 1332 #ifdef CONFIG_FAULT_INJECTION 1333 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1334 size_t count, loff_t *ppos) 1335 { 1336 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1337 char buffer[PROC_NUMBUF]; 1338 size_t len; 1339 int make_it_fail; 1340 1341 if (!task) 1342 return -ESRCH; 1343 make_it_fail = task->make_it_fail; 1344 put_task_struct(task); 1345 1346 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1347 1348 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1349 } 1350 1351 static ssize_t proc_fault_inject_write(struct file * file, 1352 const char __user * buf, size_t count, loff_t *ppos) 1353 { 1354 struct task_struct *task; 1355 char buffer[PROC_NUMBUF], *end; 1356 int make_it_fail; 1357 1358 if (!capable(CAP_SYS_RESOURCE)) 1359 return -EPERM; 1360 memset(buffer, 0, sizeof(buffer)); 1361 if (count > sizeof(buffer) - 1) 1362 count = sizeof(buffer) - 1; 1363 if (copy_from_user(buffer, buf, count)) 1364 return -EFAULT; 1365 make_it_fail = simple_strtol(strstrip(buffer), &end, 0); 1366 if (*end) 1367 return -EINVAL; 1368 task = get_proc_task(file->f_dentry->d_inode); 1369 if (!task) 1370 return -ESRCH; 1371 task->make_it_fail = make_it_fail; 1372 put_task_struct(task); 1373 1374 return count; 1375 } 1376 1377 static const struct file_operations proc_fault_inject_operations = { 1378 .read = proc_fault_inject_read, 1379 .write = proc_fault_inject_write, 1380 .llseek = generic_file_llseek, 1381 }; 1382 #endif 1383 1384 1385 #ifdef CONFIG_SCHED_DEBUG 1386 /* 1387 * Print out various scheduling related per-task fields: 1388 */ 1389 static int sched_show(struct seq_file *m, void *v) 1390 { 1391 struct inode *inode = m->private; 1392 struct task_struct *p; 1393 1394 p = get_proc_task(inode); 1395 if (!p) 1396 return -ESRCH; 1397 proc_sched_show_task(p, m); 1398 1399 put_task_struct(p); 1400 1401 return 0; 1402 } 1403 1404 static ssize_t 1405 sched_write(struct file *file, const char __user *buf, 1406 size_t count, loff_t *offset) 1407 { 1408 struct inode *inode = file->f_path.dentry->d_inode; 1409 struct task_struct *p; 1410 1411 p = get_proc_task(inode); 1412 if (!p) 1413 return -ESRCH; 1414 proc_sched_set_task(p); 1415 1416 put_task_struct(p); 1417 1418 return count; 1419 } 1420 1421 static int sched_open(struct inode *inode, struct file *filp) 1422 { 1423 return single_open(filp, sched_show, inode); 1424 } 1425 1426 static const struct file_operations proc_pid_sched_operations = { 1427 .open = sched_open, 1428 .read = seq_read, 1429 .write = sched_write, 1430 .llseek = seq_lseek, 1431 .release = single_release, 1432 }; 1433 1434 #endif 1435 1436 #ifdef CONFIG_SCHED_AUTOGROUP 1437 /* 1438 * Print out autogroup related information: 1439 */ 1440 static int sched_autogroup_show(struct seq_file *m, void *v) 1441 { 1442 struct inode *inode = m->private; 1443 struct task_struct *p; 1444 1445 p = get_proc_task(inode); 1446 if (!p) 1447 return -ESRCH; 1448 proc_sched_autogroup_show_task(p, m); 1449 1450 put_task_struct(p); 1451 1452 return 0; 1453 } 1454 1455 static ssize_t 1456 sched_autogroup_write(struct file *file, const char __user *buf, 1457 size_t count, loff_t *offset) 1458 { 1459 struct inode *inode = file->f_path.dentry->d_inode; 1460 struct task_struct *p; 1461 char buffer[PROC_NUMBUF]; 1462 int nice; 1463 int err; 1464 1465 memset(buffer, 0, sizeof(buffer)); 1466 if (count > sizeof(buffer) - 1) 1467 count = sizeof(buffer) - 1; 1468 if (copy_from_user(buffer, buf, count)) 1469 return -EFAULT; 1470 1471 err = kstrtoint(strstrip(buffer), 0, &nice); 1472 if (err < 0) 1473 return err; 1474 1475 p = get_proc_task(inode); 1476 if (!p) 1477 return -ESRCH; 1478 1479 err = nice; 1480 err = proc_sched_autogroup_set_nice(p, &err); 1481 if (err) 1482 count = err; 1483 1484 put_task_struct(p); 1485 1486 return count; 1487 } 1488 1489 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1490 { 1491 int ret; 1492 1493 ret = single_open(filp, sched_autogroup_show, NULL); 1494 if (!ret) { 1495 struct seq_file *m = filp->private_data; 1496 1497 m->private = inode; 1498 } 1499 return ret; 1500 } 1501 1502 static const struct file_operations proc_pid_sched_autogroup_operations = { 1503 .open = sched_autogroup_open, 1504 .read = seq_read, 1505 .write = sched_autogroup_write, 1506 .llseek = seq_lseek, 1507 .release = single_release, 1508 }; 1509 1510 #endif /* CONFIG_SCHED_AUTOGROUP */ 1511 1512 static ssize_t comm_write(struct file *file, const char __user *buf, 1513 size_t count, loff_t *offset) 1514 { 1515 struct inode *inode = file->f_path.dentry->d_inode; 1516 struct task_struct *p; 1517 char buffer[TASK_COMM_LEN]; 1518 1519 memset(buffer, 0, sizeof(buffer)); 1520 if (count > sizeof(buffer) - 1) 1521 count = sizeof(buffer) - 1; 1522 if (copy_from_user(buffer, buf, count)) 1523 return -EFAULT; 1524 1525 p = get_proc_task(inode); 1526 if (!p) 1527 return -ESRCH; 1528 1529 if (same_thread_group(current, p)) 1530 set_task_comm(p, buffer); 1531 else 1532 count = -EINVAL; 1533 1534 put_task_struct(p); 1535 1536 return count; 1537 } 1538 1539 static int comm_show(struct seq_file *m, void *v) 1540 { 1541 struct inode *inode = m->private; 1542 struct task_struct *p; 1543 1544 p = get_proc_task(inode); 1545 if (!p) 1546 return -ESRCH; 1547 1548 task_lock(p); 1549 seq_printf(m, "%s\n", p->comm); 1550 task_unlock(p); 1551 1552 put_task_struct(p); 1553 1554 return 0; 1555 } 1556 1557 static int comm_open(struct inode *inode, struct file *filp) 1558 { 1559 return single_open(filp, comm_show, inode); 1560 } 1561 1562 static const struct file_operations proc_pid_set_comm_operations = { 1563 .open = comm_open, 1564 .read = seq_read, 1565 .write = comm_write, 1566 .llseek = seq_lseek, 1567 .release = single_release, 1568 }; 1569 1570 static int proc_exe_link(struct inode *inode, struct path *exe_path) 1571 { 1572 struct task_struct *task; 1573 struct mm_struct *mm; 1574 struct file *exe_file; 1575 1576 task = get_proc_task(inode); 1577 if (!task) 1578 return -ENOENT; 1579 mm = get_task_mm(task); 1580 put_task_struct(task); 1581 if (!mm) 1582 return -ENOENT; 1583 exe_file = get_mm_exe_file(mm); 1584 mmput(mm); 1585 if (exe_file) { 1586 *exe_path = exe_file->f_path; 1587 path_get(&exe_file->f_path); 1588 fput(exe_file); 1589 return 0; 1590 } else 1591 return -ENOENT; 1592 } 1593 1594 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1595 { 1596 struct inode *inode = dentry->d_inode; 1597 int error = -EACCES; 1598 1599 /* We don't need a base pointer in the /proc filesystem */ 1600 path_put(&nd->path); 1601 1602 /* Are we allowed to snoop on the tasks file descriptors? */ 1603 if (!proc_fd_access_allowed(inode)) 1604 goto out; 1605 1606 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path); 1607 out: 1608 return ERR_PTR(error); 1609 } 1610 1611 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1612 { 1613 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1614 char *pathname; 1615 int len; 1616 1617 if (!tmp) 1618 return -ENOMEM; 1619 1620 pathname = d_path(path, tmp, PAGE_SIZE); 1621 len = PTR_ERR(pathname); 1622 if (IS_ERR(pathname)) 1623 goto out; 1624 len = tmp + PAGE_SIZE - 1 - pathname; 1625 1626 if (len > buflen) 1627 len = buflen; 1628 if (copy_to_user(buffer, pathname, len)) 1629 len = -EFAULT; 1630 out: 1631 free_page((unsigned long)tmp); 1632 return len; 1633 } 1634 1635 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1636 { 1637 int error = -EACCES; 1638 struct inode *inode = dentry->d_inode; 1639 struct path path; 1640 1641 /* Are we allowed to snoop on the tasks file descriptors? */ 1642 if (!proc_fd_access_allowed(inode)) 1643 goto out; 1644 1645 error = PROC_I(inode)->op.proc_get_link(inode, &path); 1646 if (error) 1647 goto out; 1648 1649 error = do_proc_readlink(&path, buffer, buflen); 1650 path_put(&path); 1651 out: 1652 return error; 1653 } 1654 1655 static int proc_pid_fd_link_getattr(struct vfsmount *mnt, struct dentry *dentry, 1656 struct kstat *stat) 1657 { 1658 struct inode *inode = dentry->d_inode; 1659 struct task_struct *task = get_proc_task(inode); 1660 int rc; 1661 1662 if (task == NULL) 1663 return -ESRCH; 1664 1665 rc = -EACCES; 1666 if (lock_trace(task)) 1667 goto out_task; 1668 1669 generic_fillattr(inode, stat); 1670 unlock_trace(task); 1671 rc = 0; 1672 out_task: 1673 put_task_struct(task); 1674 return rc; 1675 } 1676 1677 static const struct inode_operations proc_pid_link_inode_operations = { 1678 .readlink = proc_pid_readlink, 1679 .follow_link = proc_pid_follow_link, 1680 .setattr = proc_setattr, 1681 }; 1682 1683 static const struct inode_operations proc_fdinfo_link_inode_operations = { 1684 .setattr = proc_setattr, 1685 .getattr = proc_pid_fd_link_getattr, 1686 }; 1687 1688 static const struct inode_operations proc_fd_link_inode_operations = { 1689 .readlink = proc_pid_readlink, 1690 .follow_link = proc_pid_follow_link, 1691 .setattr = proc_setattr, 1692 .getattr = proc_pid_fd_link_getattr, 1693 }; 1694 1695 1696 /* building an inode */ 1697 1698 static int task_dumpable(struct task_struct *task) 1699 { 1700 int dumpable = 0; 1701 struct mm_struct *mm; 1702 1703 task_lock(task); 1704 mm = task->mm; 1705 if (mm) 1706 dumpable = get_dumpable(mm); 1707 task_unlock(task); 1708 if(dumpable == 1) 1709 return 1; 1710 return 0; 1711 } 1712 1713 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1714 { 1715 struct inode * inode; 1716 struct proc_inode *ei; 1717 const struct cred *cred; 1718 1719 /* We need a new inode */ 1720 1721 inode = new_inode(sb); 1722 if (!inode) 1723 goto out; 1724 1725 /* Common stuff */ 1726 ei = PROC_I(inode); 1727 inode->i_ino = get_next_ino(); 1728 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1729 inode->i_op = &proc_def_inode_operations; 1730 1731 /* 1732 * grab the reference to task. 1733 */ 1734 ei->pid = get_task_pid(task, PIDTYPE_PID); 1735 if (!ei->pid) 1736 goto out_unlock; 1737 1738 if (task_dumpable(task)) { 1739 rcu_read_lock(); 1740 cred = __task_cred(task); 1741 inode->i_uid = cred->euid; 1742 inode->i_gid = cred->egid; 1743 rcu_read_unlock(); 1744 } 1745 security_task_to_inode(task, inode); 1746 1747 out: 1748 return inode; 1749 1750 out_unlock: 1751 iput(inode); 1752 return NULL; 1753 } 1754 1755 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1756 { 1757 struct inode *inode = dentry->d_inode; 1758 struct task_struct *task; 1759 const struct cred *cred; 1760 1761 generic_fillattr(inode, stat); 1762 1763 rcu_read_lock(); 1764 stat->uid = 0; 1765 stat->gid = 0; 1766 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1767 if (task) { 1768 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1769 task_dumpable(task)) { 1770 cred = __task_cred(task); 1771 stat->uid = cred->euid; 1772 stat->gid = cred->egid; 1773 } 1774 } 1775 rcu_read_unlock(); 1776 return 0; 1777 } 1778 1779 /* dentry stuff */ 1780 1781 /* 1782 * Exceptional case: normally we are not allowed to unhash a busy 1783 * directory. In this case, however, we can do it - no aliasing problems 1784 * due to the way we treat inodes. 1785 * 1786 * Rewrite the inode's ownerships here because the owning task may have 1787 * performed a setuid(), etc. 1788 * 1789 * Before the /proc/pid/status file was created the only way to read 1790 * the effective uid of a /process was to stat /proc/pid. Reading 1791 * /proc/pid/status is slow enough that procps and other packages 1792 * kept stating /proc/pid. To keep the rules in /proc simple I have 1793 * made this apply to all per process world readable and executable 1794 * directories. 1795 */ 1796 int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1797 { 1798 struct inode *inode; 1799 struct task_struct *task; 1800 const struct cred *cred; 1801 1802 if (nd && nd->flags & LOOKUP_RCU) 1803 return -ECHILD; 1804 1805 inode = dentry->d_inode; 1806 task = get_proc_task(inode); 1807 1808 if (task) { 1809 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1810 task_dumpable(task)) { 1811 rcu_read_lock(); 1812 cred = __task_cred(task); 1813 inode->i_uid = cred->euid; 1814 inode->i_gid = cred->egid; 1815 rcu_read_unlock(); 1816 } else { 1817 inode->i_uid = 0; 1818 inode->i_gid = 0; 1819 } 1820 inode->i_mode &= ~(S_ISUID | S_ISGID); 1821 security_task_to_inode(task, inode); 1822 put_task_struct(task); 1823 return 1; 1824 } 1825 d_drop(dentry); 1826 return 0; 1827 } 1828 1829 static int pid_delete_dentry(const struct dentry * dentry) 1830 { 1831 /* Is the task we represent dead? 1832 * If so, then don't put the dentry on the lru list, 1833 * kill it immediately. 1834 */ 1835 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1836 } 1837 1838 const struct dentry_operations pid_dentry_operations = 1839 { 1840 .d_revalidate = pid_revalidate, 1841 .d_delete = pid_delete_dentry, 1842 }; 1843 1844 /* Lookups */ 1845 1846 /* 1847 * Fill a directory entry. 1848 * 1849 * If possible create the dcache entry and derive our inode number and 1850 * file type from dcache entry. 1851 * 1852 * Since all of the proc inode numbers are dynamically generated, the inode 1853 * numbers do not exist until the inode is cache. This means creating the 1854 * the dcache entry in readdir is necessary to keep the inode numbers 1855 * reported by readdir in sync with the inode numbers reported 1856 * by stat. 1857 */ 1858 int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1859 const char *name, int len, 1860 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1861 { 1862 struct dentry *child, *dir = filp->f_path.dentry; 1863 struct inode *inode; 1864 struct qstr qname; 1865 ino_t ino = 0; 1866 unsigned type = DT_UNKNOWN; 1867 1868 qname.name = name; 1869 qname.len = len; 1870 qname.hash = full_name_hash(name, len); 1871 1872 child = d_lookup(dir, &qname); 1873 if (!child) { 1874 struct dentry *new; 1875 new = d_alloc(dir, &qname); 1876 if (new) { 1877 child = instantiate(dir->d_inode, new, task, ptr); 1878 if (child) 1879 dput(new); 1880 else 1881 child = new; 1882 } 1883 } 1884 if (!child || IS_ERR(child) || !child->d_inode) 1885 goto end_instantiate; 1886 inode = child->d_inode; 1887 if (inode) { 1888 ino = inode->i_ino; 1889 type = inode->i_mode >> 12; 1890 } 1891 dput(child); 1892 end_instantiate: 1893 if (!ino) 1894 ino = find_inode_number(dir, &qname); 1895 if (!ino) 1896 ino = 1; 1897 return filldir(dirent, name, len, filp->f_pos, ino, type); 1898 } 1899 1900 static unsigned name_to_int(struct dentry *dentry) 1901 { 1902 const char *name = dentry->d_name.name; 1903 int len = dentry->d_name.len; 1904 unsigned n = 0; 1905 1906 if (len > 1 && *name == '0') 1907 goto out; 1908 while (len-- > 0) { 1909 unsigned c = *name++ - '0'; 1910 if (c > 9) 1911 goto out; 1912 if (n >= (~0U-9)/10) 1913 goto out; 1914 n *= 10; 1915 n += c; 1916 } 1917 return n; 1918 out: 1919 return ~0U; 1920 } 1921 1922 #define PROC_FDINFO_MAX 64 1923 1924 static int proc_fd_info(struct inode *inode, struct path *path, char *info) 1925 { 1926 struct task_struct *task; 1927 struct files_struct *files; 1928 struct file *file; 1929 int fd = proc_fd(inode); 1930 int rc; 1931 1932 task = get_proc_task(inode); 1933 if (!task) 1934 return -ENOENT; 1935 1936 rc = -EACCES; 1937 if (lock_trace(task)) 1938 goto out_task; 1939 1940 rc = -ENOENT; 1941 files = get_files_struct(task); 1942 if (files == NULL) 1943 goto out_unlock; 1944 1945 /* 1946 * We are not taking a ref to the file structure, so we must 1947 * hold ->file_lock. 1948 */ 1949 spin_lock(&files->file_lock); 1950 file = fcheck_files(files, fd); 1951 if (file) { 1952 unsigned int f_flags; 1953 struct fdtable *fdt; 1954 1955 fdt = files_fdtable(files); 1956 f_flags = file->f_flags & ~O_CLOEXEC; 1957 if (FD_ISSET(fd, fdt->close_on_exec)) 1958 f_flags |= O_CLOEXEC; 1959 1960 if (path) { 1961 *path = file->f_path; 1962 path_get(&file->f_path); 1963 } 1964 if (info) 1965 snprintf(info, PROC_FDINFO_MAX, 1966 "pos:\t%lli\n" 1967 "flags:\t0%o\n", 1968 (long long) file->f_pos, 1969 f_flags); 1970 rc = 0; 1971 } else 1972 rc = -ENOENT; 1973 spin_unlock(&files->file_lock); 1974 put_files_struct(files); 1975 1976 out_unlock: 1977 unlock_trace(task); 1978 out_task: 1979 put_task_struct(task); 1980 return rc; 1981 } 1982 1983 static int proc_fd_link(struct inode *inode, struct path *path) 1984 { 1985 return proc_fd_info(inode, path, NULL); 1986 } 1987 1988 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1989 { 1990 struct inode *inode; 1991 struct task_struct *task; 1992 int fd; 1993 struct files_struct *files; 1994 const struct cred *cred; 1995 1996 if (nd && nd->flags & LOOKUP_RCU) 1997 return -ECHILD; 1998 1999 inode = dentry->d_inode; 2000 task = get_proc_task(inode); 2001 fd = proc_fd(inode); 2002 2003 if (task) { 2004 files = get_files_struct(task); 2005 if (files) { 2006 rcu_read_lock(); 2007 if (fcheck_files(files, fd)) { 2008 rcu_read_unlock(); 2009 put_files_struct(files); 2010 if (task_dumpable(task)) { 2011 rcu_read_lock(); 2012 cred = __task_cred(task); 2013 inode->i_uid = cred->euid; 2014 inode->i_gid = cred->egid; 2015 rcu_read_unlock(); 2016 } else { 2017 inode->i_uid = 0; 2018 inode->i_gid = 0; 2019 } 2020 inode->i_mode &= ~(S_ISUID | S_ISGID); 2021 security_task_to_inode(task, inode); 2022 put_task_struct(task); 2023 return 1; 2024 } 2025 rcu_read_unlock(); 2026 put_files_struct(files); 2027 } 2028 put_task_struct(task); 2029 } 2030 d_drop(dentry); 2031 return 0; 2032 } 2033 2034 static const struct dentry_operations tid_fd_dentry_operations = 2035 { 2036 .d_revalidate = tid_fd_revalidate, 2037 .d_delete = pid_delete_dentry, 2038 }; 2039 2040 static struct dentry *proc_fd_instantiate(struct inode *dir, 2041 struct dentry *dentry, struct task_struct *task, const void *ptr) 2042 { 2043 unsigned fd = *(const unsigned *)ptr; 2044 struct file *file; 2045 struct files_struct *files; 2046 struct inode *inode; 2047 struct proc_inode *ei; 2048 struct dentry *error = ERR_PTR(-ENOENT); 2049 2050 inode = proc_pid_make_inode(dir->i_sb, task); 2051 if (!inode) 2052 goto out; 2053 ei = PROC_I(inode); 2054 ei->fd = fd; 2055 files = get_files_struct(task); 2056 if (!files) 2057 goto out_iput; 2058 inode->i_mode = S_IFLNK; 2059 2060 /* 2061 * We are not taking a ref to the file structure, so we must 2062 * hold ->file_lock. 2063 */ 2064 spin_lock(&files->file_lock); 2065 file = fcheck_files(files, fd); 2066 if (!file) 2067 goto out_unlock; 2068 if (file->f_mode & FMODE_READ) 2069 inode->i_mode |= S_IRUSR | S_IXUSR; 2070 if (file->f_mode & FMODE_WRITE) 2071 inode->i_mode |= S_IWUSR | S_IXUSR; 2072 spin_unlock(&files->file_lock); 2073 put_files_struct(files); 2074 2075 inode->i_op = &proc_fd_link_inode_operations; 2076 inode->i_size = 64; 2077 ei->op.proc_get_link = proc_fd_link; 2078 d_set_d_op(dentry, &tid_fd_dentry_operations); 2079 d_add(dentry, inode); 2080 /* Close the race of the process dying before we return the dentry */ 2081 if (tid_fd_revalidate(dentry, NULL)) 2082 error = NULL; 2083 2084 out: 2085 return error; 2086 out_unlock: 2087 spin_unlock(&files->file_lock); 2088 put_files_struct(files); 2089 out_iput: 2090 iput(inode); 2091 goto out; 2092 } 2093 2094 static struct dentry *proc_lookupfd_common(struct inode *dir, 2095 struct dentry *dentry, 2096 instantiate_t instantiate) 2097 { 2098 struct task_struct *task = get_proc_task(dir); 2099 unsigned fd = name_to_int(dentry); 2100 struct dentry *result = ERR_PTR(-ENOENT); 2101 2102 if (!task) 2103 goto out_no_task; 2104 if (fd == ~0U) 2105 goto out; 2106 2107 result = ERR_PTR(-EACCES); 2108 if (lock_trace(task)) 2109 goto out; 2110 2111 result = instantiate(dir, dentry, task, &fd); 2112 unlock_trace(task); 2113 out: 2114 put_task_struct(task); 2115 out_no_task: 2116 return result; 2117 } 2118 2119 static int proc_readfd_common(struct file * filp, void * dirent, 2120 filldir_t filldir, instantiate_t instantiate) 2121 { 2122 struct dentry *dentry = filp->f_path.dentry; 2123 struct inode *inode = dentry->d_inode; 2124 struct task_struct *p = get_proc_task(inode); 2125 unsigned int fd, ino; 2126 int retval; 2127 struct files_struct * files; 2128 2129 retval = -ENOENT; 2130 if (!p) 2131 goto out_no_task; 2132 2133 retval = -EACCES; 2134 if (lock_trace(p)) 2135 goto out; 2136 2137 retval = 0; 2138 2139 fd = filp->f_pos; 2140 switch (fd) { 2141 case 0: 2142 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 2143 goto out_unlock; 2144 filp->f_pos++; 2145 case 1: 2146 ino = parent_ino(dentry); 2147 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 2148 goto out_unlock; 2149 filp->f_pos++; 2150 default: 2151 files = get_files_struct(p); 2152 if (!files) 2153 goto out_unlock; 2154 rcu_read_lock(); 2155 for (fd = filp->f_pos-2; 2156 fd < files_fdtable(files)->max_fds; 2157 fd++, filp->f_pos++) { 2158 char name[PROC_NUMBUF]; 2159 int len; 2160 2161 if (!fcheck_files(files, fd)) 2162 continue; 2163 rcu_read_unlock(); 2164 2165 len = snprintf(name, sizeof(name), "%d", fd); 2166 if (proc_fill_cache(filp, dirent, filldir, 2167 name, len, instantiate, 2168 p, &fd) < 0) { 2169 rcu_read_lock(); 2170 break; 2171 } 2172 rcu_read_lock(); 2173 } 2174 rcu_read_unlock(); 2175 put_files_struct(files); 2176 } 2177 2178 out_unlock: 2179 unlock_trace(p); 2180 out: 2181 put_task_struct(p); 2182 out_no_task: 2183 return retval; 2184 } 2185 2186 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 2187 struct nameidata *nd) 2188 { 2189 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 2190 } 2191 2192 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 2193 { 2194 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 2195 } 2196 2197 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 2198 size_t len, loff_t *ppos) 2199 { 2200 char tmp[PROC_FDINFO_MAX]; 2201 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); 2202 if (!err) 2203 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 2204 return err; 2205 } 2206 2207 static const struct file_operations proc_fdinfo_file_operations = { 2208 .open = nonseekable_open, 2209 .read = proc_fdinfo_read, 2210 .llseek = no_llseek, 2211 }; 2212 2213 static const struct file_operations proc_fd_operations = { 2214 .read = generic_read_dir, 2215 .readdir = proc_readfd, 2216 .llseek = default_llseek, 2217 }; 2218 2219 /* 2220 * /proc/pid/fd needs a special permission handler so that a process can still 2221 * access /proc/self/fd after it has executed a setuid(). 2222 */ 2223 static int proc_fd_permission(struct inode *inode, int mask) 2224 { 2225 int rv = generic_permission(inode, mask); 2226 if (rv == 0) 2227 return 0; 2228 if (task_pid(current) == proc_pid(inode)) 2229 rv = 0; 2230 return rv; 2231 } 2232 2233 /* 2234 * proc directories can do almost nothing.. 2235 */ 2236 static const struct inode_operations proc_fd_inode_operations = { 2237 .lookup = proc_lookupfd, 2238 .permission = proc_fd_permission, 2239 .setattr = proc_setattr, 2240 }; 2241 2242 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 2243 struct dentry *dentry, struct task_struct *task, const void *ptr) 2244 { 2245 unsigned fd = *(unsigned *)ptr; 2246 struct inode *inode; 2247 struct proc_inode *ei; 2248 struct dentry *error = ERR_PTR(-ENOENT); 2249 2250 inode = proc_pid_make_inode(dir->i_sb, task); 2251 if (!inode) 2252 goto out; 2253 ei = PROC_I(inode); 2254 ei->fd = fd; 2255 inode->i_mode = S_IFREG | S_IRUSR; 2256 inode->i_fop = &proc_fdinfo_file_operations; 2257 inode->i_op = &proc_fdinfo_link_inode_operations; 2258 d_set_d_op(dentry, &tid_fd_dentry_operations); 2259 d_add(dentry, inode); 2260 /* Close the race of the process dying before we return the dentry */ 2261 if (tid_fd_revalidate(dentry, NULL)) 2262 error = NULL; 2263 2264 out: 2265 return error; 2266 } 2267 2268 static struct dentry *proc_lookupfdinfo(struct inode *dir, 2269 struct dentry *dentry, 2270 struct nameidata *nd) 2271 { 2272 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 2273 } 2274 2275 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 2276 { 2277 return proc_readfd_common(filp, dirent, filldir, 2278 proc_fdinfo_instantiate); 2279 } 2280 2281 static const struct file_operations proc_fdinfo_operations = { 2282 .read = generic_read_dir, 2283 .readdir = proc_readfdinfo, 2284 .llseek = default_llseek, 2285 }; 2286 2287 /* 2288 * proc directories can do almost nothing.. 2289 */ 2290 static const struct inode_operations proc_fdinfo_inode_operations = { 2291 .lookup = proc_lookupfdinfo, 2292 .setattr = proc_setattr, 2293 }; 2294 2295 2296 static struct dentry *proc_pident_instantiate(struct inode *dir, 2297 struct dentry *dentry, struct task_struct *task, const void *ptr) 2298 { 2299 const struct pid_entry *p = ptr; 2300 struct inode *inode; 2301 struct proc_inode *ei; 2302 struct dentry *error = ERR_PTR(-ENOENT); 2303 2304 inode = proc_pid_make_inode(dir->i_sb, task); 2305 if (!inode) 2306 goto out; 2307 2308 ei = PROC_I(inode); 2309 inode->i_mode = p->mode; 2310 if (S_ISDIR(inode->i_mode)) 2311 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2312 if (p->iop) 2313 inode->i_op = p->iop; 2314 if (p->fop) 2315 inode->i_fop = p->fop; 2316 ei->op = p->op; 2317 d_set_d_op(dentry, &pid_dentry_operations); 2318 d_add(dentry, inode); 2319 /* Close the race of the process dying before we return the dentry */ 2320 if (pid_revalidate(dentry, NULL)) 2321 error = NULL; 2322 out: 2323 return error; 2324 } 2325 2326 static struct dentry *proc_pident_lookup(struct inode *dir, 2327 struct dentry *dentry, 2328 const struct pid_entry *ents, 2329 unsigned int nents) 2330 { 2331 struct dentry *error; 2332 struct task_struct *task = get_proc_task(dir); 2333 const struct pid_entry *p, *last; 2334 2335 error = ERR_PTR(-ENOENT); 2336 2337 if (!task) 2338 goto out_no_task; 2339 2340 /* 2341 * Yes, it does not scale. And it should not. Don't add 2342 * new entries into /proc/<tgid>/ without very good reasons. 2343 */ 2344 last = &ents[nents - 1]; 2345 for (p = ents; p <= last; p++) { 2346 if (p->len != dentry->d_name.len) 2347 continue; 2348 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2349 break; 2350 } 2351 if (p > last) 2352 goto out; 2353 2354 error = proc_pident_instantiate(dir, dentry, task, p); 2355 out: 2356 put_task_struct(task); 2357 out_no_task: 2358 return error; 2359 } 2360 2361 static int proc_pident_fill_cache(struct file *filp, void *dirent, 2362 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2363 { 2364 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2365 proc_pident_instantiate, task, p); 2366 } 2367 2368 static int proc_pident_readdir(struct file *filp, 2369 void *dirent, filldir_t filldir, 2370 const struct pid_entry *ents, unsigned int nents) 2371 { 2372 int i; 2373 struct dentry *dentry = filp->f_path.dentry; 2374 struct inode *inode = dentry->d_inode; 2375 struct task_struct *task = get_proc_task(inode); 2376 const struct pid_entry *p, *last; 2377 ino_t ino; 2378 int ret; 2379 2380 ret = -ENOENT; 2381 if (!task) 2382 goto out_no_task; 2383 2384 ret = 0; 2385 i = filp->f_pos; 2386 switch (i) { 2387 case 0: 2388 ino = inode->i_ino; 2389 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 2390 goto out; 2391 i++; 2392 filp->f_pos++; 2393 /* fall through */ 2394 case 1: 2395 ino = parent_ino(dentry); 2396 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 2397 goto out; 2398 i++; 2399 filp->f_pos++; 2400 /* fall through */ 2401 default: 2402 i -= 2; 2403 if (i >= nents) { 2404 ret = 1; 2405 goto out; 2406 } 2407 p = ents + i; 2408 last = &ents[nents - 1]; 2409 while (p <= last) { 2410 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2411 goto out; 2412 filp->f_pos++; 2413 p++; 2414 } 2415 } 2416 2417 ret = 1; 2418 out: 2419 put_task_struct(task); 2420 out_no_task: 2421 return ret; 2422 } 2423 2424 #ifdef CONFIG_SECURITY 2425 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2426 size_t count, loff_t *ppos) 2427 { 2428 struct inode * inode = file->f_path.dentry->d_inode; 2429 char *p = NULL; 2430 ssize_t length; 2431 struct task_struct *task = get_proc_task(inode); 2432 2433 if (!task) 2434 return -ESRCH; 2435 2436 length = security_getprocattr(task, 2437 (char*)file->f_path.dentry->d_name.name, 2438 &p); 2439 put_task_struct(task); 2440 if (length > 0) 2441 length = simple_read_from_buffer(buf, count, ppos, p, length); 2442 kfree(p); 2443 return length; 2444 } 2445 2446 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2447 size_t count, loff_t *ppos) 2448 { 2449 struct inode * inode = file->f_path.dentry->d_inode; 2450 char *page; 2451 ssize_t length; 2452 struct task_struct *task = get_proc_task(inode); 2453 2454 length = -ESRCH; 2455 if (!task) 2456 goto out_no_task; 2457 if (count > PAGE_SIZE) 2458 count = PAGE_SIZE; 2459 2460 /* No partial writes. */ 2461 length = -EINVAL; 2462 if (*ppos != 0) 2463 goto out; 2464 2465 length = -ENOMEM; 2466 page = (char*)__get_free_page(GFP_TEMPORARY); 2467 if (!page) 2468 goto out; 2469 2470 length = -EFAULT; 2471 if (copy_from_user(page, buf, count)) 2472 goto out_free; 2473 2474 /* Guard against adverse ptrace interaction */ 2475 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex); 2476 if (length < 0) 2477 goto out_free; 2478 2479 length = security_setprocattr(task, 2480 (char*)file->f_path.dentry->d_name.name, 2481 (void*)page, count); 2482 mutex_unlock(&task->signal->cred_guard_mutex); 2483 out_free: 2484 free_page((unsigned long) page); 2485 out: 2486 put_task_struct(task); 2487 out_no_task: 2488 return length; 2489 } 2490 2491 static const struct file_operations proc_pid_attr_operations = { 2492 .read = proc_pid_attr_read, 2493 .write = proc_pid_attr_write, 2494 .llseek = generic_file_llseek, 2495 }; 2496 2497 static const struct pid_entry attr_dir_stuff[] = { 2498 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2499 REG("prev", S_IRUGO, proc_pid_attr_operations), 2500 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2501 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2502 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2503 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2504 }; 2505 2506 static int proc_attr_dir_readdir(struct file * filp, 2507 void * dirent, filldir_t filldir) 2508 { 2509 return proc_pident_readdir(filp,dirent,filldir, 2510 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2511 } 2512 2513 static const struct file_operations proc_attr_dir_operations = { 2514 .read = generic_read_dir, 2515 .readdir = proc_attr_dir_readdir, 2516 .llseek = default_llseek, 2517 }; 2518 2519 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2520 struct dentry *dentry, struct nameidata *nd) 2521 { 2522 return proc_pident_lookup(dir, dentry, 2523 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2524 } 2525 2526 static const struct inode_operations proc_attr_dir_inode_operations = { 2527 .lookup = proc_attr_dir_lookup, 2528 .getattr = pid_getattr, 2529 .setattr = proc_setattr, 2530 }; 2531 2532 #endif 2533 2534 #ifdef CONFIG_ELF_CORE 2535 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2536 size_t count, loff_t *ppos) 2537 { 2538 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2539 struct mm_struct *mm; 2540 char buffer[PROC_NUMBUF]; 2541 size_t len; 2542 int ret; 2543 2544 if (!task) 2545 return -ESRCH; 2546 2547 ret = 0; 2548 mm = get_task_mm(task); 2549 if (mm) { 2550 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2551 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2552 MMF_DUMP_FILTER_SHIFT)); 2553 mmput(mm); 2554 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2555 } 2556 2557 put_task_struct(task); 2558 2559 return ret; 2560 } 2561 2562 static ssize_t proc_coredump_filter_write(struct file *file, 2563 const char __user *buf, 2564 size_t count, 2565 loff_t *ppos) 2566 { 2567 struct task_struct *task; 2568 struct mm_struct *mm; 2569 char buffer[PROC_NUMBUF], *end; 2570 unsigned int val; 2571 int ret; 2572 int i; 2573 unsigned long mask; 2574 2575 ret = -EFAULT; 2576 memset(buffer, 0, sizeof(buffer)); 2577 if (count > sizeof(buffer) - 1) 2578 count = sizeof(buffer) - 1; 2579 if (copy_from_user(buffer, buf, count)) 2580 goto out_no_task; 2581 2582 ret = -EINVAL; 2583 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2584 if (*end == '\n') 2585 end++; 2586 if (end - buffer == 0) 2587 goto out_no_task; 2588 2589 ret = -ESRCH; 2590 task = get_proc_task(file->f_dentry->d_inode); 2591 if (!task) 2592 goto out_no_task; 2593 2594 ret = end - buffer; 2595 mm = get_task_mm(task); 2596 if (!mm) 2597 goto out_no_mm; 2598 2599 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2600 if (val & mask) 2601 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2602 else 2603 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2604 } 2605 2606 mmput(mm); 2607 out_no_mm: 2608 put_task_struct(task); 2609 out_no_task: 2610 return ret; 2611 } 2612 2613 static const struct file_operations proc_coredump_filter_operations = { 2614 .read = proc_coredump_filter_read, 2615 .write = proc_coredump_filter_write, 2616 .llseek = generic_file_llseek, 2617 }; 2618 #endif 2619 2620 /* 2621 * /proc/self: 2622 */ 2623 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2624 int buflen) 2625 { 2626 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2627 pid_t tgid = task_tgid_nr_ns(current, ns); 2628 char tmp[PROC_NUMBUF]; 2629 if (!tgid) 2630 return -ENOENT; 2631 sprintf(tmp, "%d", tgid); 2632 return vfs_readlink(dentry,buffer,buflen,tmp); 2633 } 2634 2635 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2636 { 2637 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2638 pid_t tgid = task_tgid_nr_ns(current, ns); 2639 char *name = ERR_PTR(-ENOENT); 2640 if (tgid) { 2641 name = __getname(); 2642 if (!name) 2643 name = ERR_PTR(-ENOMEM); 2644 else 2645 sprintf(name, "%d", tgid); 2646 } 2647 nd_set_link(nd, name); 2648 return NULL; 2649 } 2650 2651 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd, 2652 void *cookie) 2653 { 2654 char *s = nd_get_link(nd); 2655 if (!IS_ERR(s)) 2656 __putname(s); 2657 } 2658 2659 static const struct inode_operations proc_self_inode_operations = { 2660 .readlink = proc_self_readlink, 2661 .follow_link = proc_self_follow_link, 2662 .put_link = proc_self_put_link, 2663 }; 2664 2665 /* 2666 * proc base 2667 * 2668 * These are the directory entries in the root directory of /proc 2669 * that properly belong to the /proc filesystem, as they describe 2670 * describe something that is process related. 2671 */ 2672 static const struct pid_entry proc_base_stuff[] = { 2673 NOD("self", S_IFLNK|S_IRWXUGO, 2674 &proc_self_inode_operations, NULL, {}), 2675 }; 2676 2677 static struct dentry *proc_base_instantiate(struct inode *dir, 2678 struct dentry *dentry, struct task_struct *task, const void *ptr) 2679 { 2680 const struct pid_entry *p = ptr; 2681 struct inode *inode; 2682 struct proc_inode *ei; 2683 struct dentry *error; 2684 2685 /* Allocate the inode */ 2686 error = ERR_PTR(-ENOMEM); 2687 inode = new_inode(dir->i_sb); 2688 if (!inode) 2689 goto out; 2690 2691 /* Initialize the inode */ 2692 ei = PROC_I(inode); 2693 inode->i_ino = get_next_ino(); 2694 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2695 2696 /* 2697 * grab the reference to the task. 2698 */ 2699 ei->pid = get_task_pid(task, PIDTYPE_PID); 2700 if (!ei->pid) 2701 goto out_iput; 2702 2703 inode->i_mode = p->mode; 2704 if (S_ISDIR(inode->i_mode)) 2705 set_nlink(inode, 2); 2706 if (S_ISLNK(inode->i_mode)) 2707 inode->i_size = 64; 2708 if (p->iop) 2709 inode->i_op = p->iop; 2710 if (p->fop) 2711 inode->i_fop = p->fop; 2712 ei->op = p->op; 2713 d_add(dentry, inode); 2714 error = NULL; 2715 out: 2716 return error; 2717 out_iput: 2718 iput(inode); 2719 goto out; 2720 } 2721 2722 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2723 { 2724 struct dentry *error; 2725 struct task_struct *task = get_proc_task(dir); 2726 const struct pid_entry *p, *last; 2727 2728 error = ERR_PTR(-ENOENT); 2729 2730 if (!task) 2731 goto out_no_task; 2732 2733 /* Lookup the directory entry */ 2734 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2735 for (p = proc_base_stuff; p <= last; p++) { 2736 if (p->len != dentry->d_name.len) 2737 continue; 2738 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2739 break; 2740 } 2741 if (p > last) 2742 goto out; 2743 2744 error = proc_base_instantiate(dir, dentry, task, p); 2745 2746 out: 2747 put_task_struct(task); 2748 out_no_task: 2749 return error; 2750 } 2751 2752 static int proc_base_fill_cache(struct file *filp, void *dirent, 2753 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2754 { 2755 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2756 proc_base_instantiate, task, p); 2757 } 2758 2759 #ifdef CONFIG_TASK_IO_ACCOUNTING 2760 static int do_io_accounting(struct task_struct *task, char *buffer, int whole) 2761 { 2762 struct task_io_accounting acct = task->ioac; 2763 unsigned long flags; 2764 int result; 2765 2766 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2767 if (result) 2768 return result; 2769 2770 if (!ptrace_may_access(task, PTRACE_MODE_READ)) { 2771 result = -EACCES; 2772 goto out_unlock; 2773 } 2774 2775 if (whole && lock_task_sighand(task, &flags)) { 2776 struct task_struct *t = task; 2777 2778 task_io_accounting_add(&acct, &task->signal->ioac); 2779 while_each_thread(task, t) 2780 task_io_accounting_add(&acct, &t->ioac); 2781 2782 unlock_task_sighand(task, &flags); 2783 } 2784 result = sprintf(buffer, 2785 "rchar: %llu\n" 2786 "wchar: %llu\n" 2787 "syscr: %llu\n" 2788 "syscw: %llu\n" 2789 "read_bytes: %llu\n" 2790 "write_bytes: %llu\n" 2791 "cancelled_write_bytes: %llu\n", 2792 (unsigned long long)acct.rchar, 2793 (unsigned long long)acct.wchar, 2794 (unsigned long long)acct.syscr, 2795 (unsigned long long)acct.syscw, 2796 (unsigned long long)acct.read_bytes, 2797 (unsigned long long)acct.write_bytes, 2798 (unsigned long long)acct.cancelled_write_bytes); 2799 out_unlock: 2800 mutex_unlock(&task->signal->cred_guard_mutex); 2801 return result; 2802 } 2803 2804 static int proc_tid_io_accounting(struct task_struct *task, char *buffer) 2805 { 2806 return do_io_accounting(task, buffer, 0); 2807 } 2808 2809 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer) 2810 { 2811 return do_io_accounting(task, buffer, 1); 2812 } 2813 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2814 2815 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2816 struct pid *pid, struct task_struct *task) 2817 { 2818 int err = lock_trace(task); 2819 if (!err) { 2820 seq_printf(m, "%08x\n", task->personality); 2821 unlock_trace(task); 2822 } 2823 return err; 2824 } 2825 2826 /* 2827 * Thread groups 2828 */ 2829 static const struct file_operations proc_task_operations; 2830 static const struct inode_operations proc_task_inode_operations; 2831 2832 static const struct pid_entry tgid_base_stuff[] = { 2833 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2834 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2835 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2836 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2837 #ifdef CONFIG_NET 2838 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2839 #endif 2840 REG("environ", S_IRUSR, proc_environ_operations), 2841 INF("auxv", S_IRUSR, proc_pid_auxv), 2842 ONE("status", S_IRUGO, proc_pid_status), 2843 ONE("personality", S_IRUGO, proc_pid_personality), 2844 INF("limits", S_IRUGO, proc_pid_limits), 2845 #ifdef CONFIG_SCHED_DEBUG 2846 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2847 #endif 2848 #ifdef CONFIG_SCHED_AUTOGROUP 2849 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2850 #endif 2851 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2852 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2853 INF("syscall", S_IRUGO, proc_pid_syscall), 2854 #endif 2855 INF("cmdline", S_IRUGO, proc_pid_cmdline), 2856 ONE("stat", S_IRUGO, proc_tgid_stat), 2857 ONE("statm", S_IRUGO, proc_pid_statm), 2858 REG("maps", S_IRUGO, proc_maps_operations), 2859 #ifdef CONFIG_NUMA 2860 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 2861 #endif 2862 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2863 LNK("cwd", proc_cwd_link), 2864 LNK("root", proc_root_link), 2865 LNK("exe", proc_exe_link), 2866 REG("mounts", S_IRUGO, proc_mounts_operations), 2867 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2868 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2869 #ifdef CONFIG_PROC_PAGE_MONITOR 2870 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2871 REG("smaps", S_IRUGO, proc_smaps_operations), 2872 REG("pagemap", S_IRUGO, proc_pagemap_operations), 2873 #endif 2874 #ifdef CONFIG_SECURITY 2875 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2876 #endif 2877 #ifdef CONFIG_KALLSYMS 2878 INF("wchan", S_IRUGO, proc_pid_wchan), 2879 #endif 2880 #ifdef CONFIG_STACKTRACE 2881 ONE("stack", S_IRUGO, proc_pid_stack), 2882 #endif 2883 #ifdef CONFIG_SCHEDSTATS 2884 INF("schedstat", S_IRUGO, proc_pid_schedstat), 2885 #endif 2886 #ifdef CONFIG_LATENCYTOP 2887 REG("latency", S_IRUGO, proc_lstats_operations), 2888 #endif 2889 #ifdef CONFIG_PROC_PID_CPUSET 2890 REG("cpuset", S_IRUGO, proc_cpuset_operations), 2891 #endif 2892 #ifdef CONFIG_CGROUPS 2893 REG("cgroup", S_IRUGO, proc_cgroup_operations), 2894 #endif 2895 INF("oom_score", S_IRUGO, proc_oom_score), 2896 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 2897 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2898 #ifdef CONFIG_AUDITSYSCALL 2899 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2900 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2901 #endif 2902 #ifdef CONFIG_FAULT_INJECTION 2903 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2904 #endif 2905 #ifdef CONFIG_ELF_CORE 2906 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2907 #endif 2908 #ifdef CONFIG_TASK_IO_ACCOUNTING 2909 INF("io", S_IRUSR, proc_tgid_io_accounting), 2910 #endif 2911 #ifdef CONFIG_HARDWALL 2912 INF("hardwall", S_IRUGO, proc_pid_hardwall), 2913 #endif 2914 }; 2915 2916 static int proc_tgid_base_readdir(struct file * filp, 2917 void * dirent, filldir_t filldir) 2918 { 2919 return proc_pident_readdir(filp,dirent,filldir, 2920 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2921 } 2922 2923 static const struct file_operations proc_tgid_base_operations = { 2924 .read = generic_read_dir, 2925 .readdir = proc_tgid_base_readdir, 2926 .llseek = default_llseek, 2927 }; 2928 2929 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2930 return proc_pident_lookup(dir, dentry, 2931 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2932 } 2933 2934 static const struct inode_operations proc_tgid_base_inode_operations = { 2935 .lookup = proc_tgid_base_lookup, 2936 .getattr = pid_getattr, 2937 .setattr = proc_setattr, 2938 }; 2939 2940 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2941 { 2942 struct dentry *dentry, *leader, *dir; 2943 char buf[PROC_NUMBUF]; 2944 struct qstr name; 2945 2946 name.name = buf; 2947 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2948 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2949 if (dentry) { 2950 shrink_dcache_parent(dentry); 2951 d_drop(dentry); 2952 dput(dentry); 2953 } 2954 2955 name.name = buf; 2956 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2957 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2958 if (!leader) 2959 goto out; 2960 2961 name.name = "task"; 2962 name.len = strlen(name.name); 2963 dir = d_hash_and_lookup(leader, &name); 2964 if (!dir) 2965 goto out_put_leader; 2966 2967 name.name = buf; 2968 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2969 dentry = d_hash_and_lookup(dir, &name); 2970 if (dentry) { 2971 shrink_dcache_parent(dentry); 2972 d_drop(dentry); 2973 dput(dentry); 2974 } 2975 2976 dput(dir); 2977 out_put_leader: 2978 dput(leader); 2979 out: 2980 return; 2981 } 2982 2983 /** 2984 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2985 * @task: task that should be flushed. 2986 * 2987 * When flushing dentries from proc, one needs to flush them from global 2988 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2989 * in. This call is supposed to do all of this job. 2990 * 2991 * Looks in the dcache for 2992 * /proc/@pid 2993 * /proc/@tgid/task/@pid 2994 * if either directory is present flushes it and all of it'ts children 2995 * from the dcache. 2996 * 2997 * It is safe and reasonable to cache /proc entries for a task until 2998 * that task exits. After that they just clog up the dcache with 2999 * useless entries, possibly causing useful dcache entries to be 3000 * flushed instead. This routine is proved to flush those useless 3001 * dcache entries at process exit time. 3002 * 3003 * NOTE: This routine is just an optimization so it does not guarantee 3004 * that no dcache entries will exist at process exit time it 3005 * just makes it very unlikely that any will persist. 3006 */ 3007 3008 void proc_flush_task(struct task_struct *task) 3009 { 3010 int i; 3011 struct pid *pid, *tgid; 3012 struct upid *upid; 3013 3014 pid = task_pid(task); 3015 tgid = task_tgid(task); 3016 3017 for (i = 0; i <= pid->level; i++) { 3018 upid = &pid->numbers[i]; 3019 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3020 tgid->numbers[i].nr); 3021 } 3022 3023 upid = &pid->numbers[pid->level]; 3024 if (upid->nr == 1) 3025 pid_ns_release_proc(upid->ns); 3026 } 3027 3028 static struct dentry *proc_pid_instantiate(struct inode *dir, 3029 struct dentry * dentry, 3030 struct task_struct *task, const void *ptr) 3031 { 3032 struct dentry *error = ERR_PTR(-ENOENT); 3033 struct inode *inode; 3034 3035 inode = proc_pid_make_inode(dir->i_sb, task); 3036 if (!inode) 3037 goto out; 3038 3039 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3040 inode->i_op = &proc_tgid_base_inode_operations; 3041 inode->i_fop = &proc_tgid_base_operations; 3042 inode->i_flags|=S_IMMUTABLE; 3043 3044 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff, 3045 ARRAY_SIZE(tgid_base_stuff))); 3046 3047 d_set_d_op(dentry, &pid_dentry_operations); 3048 3049 d_add(dentry, inode); 3050 /* Close the race of the process dying before we return the dentry */ 3051 if (pid_revalidate(dentry, NULL)) 3052 error = NULL; 3053 out: 3054 return error; 3055 } 3056 3057 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 3058 { 3059 struct dentry *result; 3060 struct task_struct *task; 3061 unsigned tgid; 3062 struct pid_namespace *ns; 3063 3064 result = proc_base_lookup(dir, dentry); 3065 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 3066 goto out; 3067 3068 tgid = name_to_int(dentry); 3069 if (tgid == ~0U) 3070 goto out; 3071 3072 ns = dentry->d_sb->s_fs_info; 3073 rcu_read_lock(); 3074 task = find_task_by_pid_ns(tgid, ns); 3075 if (task) 3076 get_task_struct(task); 3077 rcu_read_unlock(); 3078 if (!task) 3079 goto out; 3080 3081 result = proc_pid_instantiate(dir, dentry, task, NULL); 3082 put_task_struct(task); 3083 out: 3084 return result; 3085 } 3086 3087 /* 3088 * Find the first task with tgid >= tgid 3089 * 3090 */ 3091 struct tgid_iter { 3092 unsigned int tgid; 3093 struct task_struct *task; 3094 }; 3095 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3096 { 3097 struct pid *pid; 3098 3099 if (iter.task) 3100 put_task_struct(iter.task); 3101 rcu_read_lock(); 3102 retry: 3103 iter.task = NULL; 3104 pid = find_ge_pid(iter.tgid, ns); 3105 if (pid) { 3106 iter.tgid = pid_nr_ns(pid, ns); 3107 iter.task = pid_task(pid, PIDTYPE_PID); 3108 /* What we to know is if the pid we have find is the 3109 * pid of a thread_group_leader. Testing for task 3110 * being a thread_group_leader is the obvious thing 3111 * todo but there is a window when it fails, due to 3112 * the pid transfer logic in de_thread. 3113 * 3114 * So we perform the straight forward test of seeing 3115 * if the pid we have found is the pid of a thread 3116 * group leader, and don't worry if the task we have 3117 * found doesn't happen to be a thread group leader. 3118 * As we don't care in the case of readdir. 3119 */ 3120 if (!iter.task || !has_group_leader_pid(iter.task)) { 3121 iter.tgid += 1; 3122 goto retry; 3123 } 3124 get_task_struct(iter.task); 3125 } 3126 rcu_read_unlock(); 3127 return iter; 3128 } 3129 3130 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 3131 3132 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3133 struct tgid_iter iter) 3134 { 3135 char name[PROC_NUMBUF]; 3136 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 3137 return proc_fill_cache(filp, dirent, filldir, name, len, 3138 proc_pid_instantiate, iter.task, NULL); 3139 } 3140 3141 /* for the /proc/ directory itself, after non-process stuff has been done */ 3142 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 3143 { 3144 unsigned int nr; 3145 struct task_struct *reaper; 3146 struct tgid_iter iter; 3147 struct pid_namespace *ns; 3148 3149 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET) 3150 goto out_no_task; 3151 nr = filp->f_pos - FIRST_PROCESS_ENTRY; 3152 3153 reaper = get_proc_task(filp->f_path.dentry->d_inode); 3154 if (!reaper) 3155 goto out_no_task; 3156 3157 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 3158 const struct pid_entry *p = &proc_base_stuff[nr]; 3159 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 3160 goto out; 3161 } 3162 3163 ns = filp->f_dentry->d_sb->s_fs_info; 3164 iter.task = NULL; 3165 iter.tgid = filp->f_pos - TGID_OFFSET; 3166 for (iter = next_tgid(ns, iter); 3167 iter.task; 3168 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3169 filp->f_pos = iter.tgid + TGID_OFFSET; 3170 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) { 3171 put_task_struct(iter.task); 3172 goto out; 3173 } 3174 } 3175 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 3176 out: 3177 put_task_struct(reaper); 3178 out_no_task: 3179 return 0; 3180 } 3181 3182 /* 3183 * Tasks 3184 */ 3185 static const struct pid_entry tid_base_stuff[] = { 3186 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3187 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3188 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3189 REG("environ", S_IRUSR, proc_environ_operations), 3190 INF("auxv", S_IRUSR, proc_pid_auxv), 3191 ONE("status", S_IRUGO, proc_pid_status), 3192 ONE("personality", S_IRUGO, proc_pid_personality), 3193 INF("limits", S_IRUGO, proc_pid_limits), 3194 #ifdef CONFIG_SCHED_DEBUG 3195 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3196 #endif 3197 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3198 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3199 INF("syscall", S_IRUGO, proc_pid_syscall), 3200 #endif 3201 INF("cmdline", S_IRUGO, proc_pid_cmdline), 3202 ONE("stat", S_IRUGO, proc_tid_stat), 3203 ONE("statm", S_IRUGO, proc_pid_statm), 3204 REG("maps", S_IRUGO, proc_maps_operations), 3205 #ifdef CONFIG_NUMA 3206 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 3207 #endif 3208 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3209 LNK("cwd", proc_cwd_link), 3210 LNK("root", proc_root_link), 3211 LNK("exe", proc_exe_link), 3212 REG("mounts", S_IRUGO, proc_mounts_operations), 3213 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3214 #ifdef CONFIG_PROC_PAGE_MONITOR 3215 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3216 REG("smaps", S_IRUGO, proc_smaps_operations), 3217 REG("pagemap", S_IRUGO, proc_pagemap_operations), 3218 #endif 3219 #ifdef CONFIG_SECURITY 3220 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3221 #endif 3222 #ifdef CONFIG_KALLSYMS 3223 INF("wchan", S_IRUGO, proc_pid_wchan), 3224 #endif 3225 #ifdef CONFIG_STACKTRACE 3226 ONE("stack", S_IRUGO, proc_pid_stack), 3227 #endif 3228 #ifdef CONFIG_SCHEDSTATS 3229 INF("schedstat", S_IRUGO, proc_pid_schedstat), 3230 #endif 3231 #ifdef CONFIG_LATENCYTOP 3232 REG("latency", S_IRUGO, proc_lstats_operations), 3233 #endif 3234 #ifdef CONFIG_PROC_PID_CPUSET 3235 REG("cpuset", S_IRUGO, proc_cpuset_operations), 3236 #endif 3237 #ifdef CONFIG_CGROUPS 3238 REG("cgroup", S_IRUGO, proc_cgroup_operations), 3239 #endif 3240 INF("oom_score", S_IRUGO, proc_oom_score), 3241 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 3242 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3243 #ifdef CONFIG_AUDITSYSCALL 3244 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3245 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3246 #endif 3247 #ifdef CONFIG_FAULT_INJECTION 3248 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3249 #endif 3250 #ifdef CONFIG_TASK_IO_ACCOUNTING 3251 INF("io", S_IRUSR, proc_tid_io_accounting), 3252 #endif 3253 #ifdef CONFIG_HARDWALL 3254 INF("hardwall", S_IRUGO, proc_pid_hardwall), 3255 #endif 3256 }; 3257 3258 static int proc_tid_base_readdir(struct file * filp, 3259 void * dirent, filldir_t filldir) 3260 { 3261 return proc_pident_readdir(filp,dirent,filldir, 3262 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 3263 } 3264 3265 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 3266 return proc_pident_lookup(dir, dentry, 3267 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3268 } 3269 3270 static const struct file_operations proc_tid_base_operations = { 3271 .read = generic_read_dir, 3272 .readdir = proc_tid_base_readdir, 3273 .llseek = default_llseek, 3274 }; 3275 3276 static const struct inode_operations proc_tid_base_inode_operations = { 3277 .lookup = proc_tid_base_lookup, 3278 .getattr = pid_getattr, 3279 .setattr = proc_setattr, 3280 }; 3281 3282 static struct dentry *proc_task_instantiate(struct inode *dir, 3283 struct dentry *dentry, struct task_struct *task, const void *ptr) 3284 { 3285 struct dentry *error = ERR_PTR(-ENOENT); 3286 struct inode *inode; 3287 inode = proc_pid_make_inode(dir->i_sb, task); 3288 3289 if (!inode) 3290 goto out; 3291 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3292 inode->i_op = &proc_tid_base_inode_operations; 3293 inode->i_fop = &proc_tid_base_operations; 3294 inode->i_flags|=S_IMMUTABLE; 3295 3296 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff, 3297 ARRAY_SIZE(tid_base_stuff))); 3298 3299 d_set_d_op(dentry, &pid_dentry_operations); 3300 3301 d_add(dentry, inode); 3302 /* Close the race of the process dying before we return the dentry */ 3303 if (pid_revalidate(dentry, NULL)) 3304 error = NULL; 3305 out: 3306 return error; 3307 } 3308 3309 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 3310 { 3311 struct dentry *result = ERR_PTR(-ENOENT); 3312 struct task_struct *task; 3313 struct task_struct *leader = get_proc_task(dir); 3314 unsigned tid; 3315 struct pid_namespace *ns; 3316 3317 if (!leader) 3318 goto out_no_task; 3319 3320 tid = name_to_int(dentry); 3321 if (tid == ~0U) 3322 goto out; 3323 3324 ns = dentry->d_sb->s_fs_info; 3325 rcu_read_lock(); 3326 task = find_task_by_pid_ns(tid, ns); 3327 if (task) 3328 get_task_struct(task); 3329 rcu_read_unlock(); 3330 if (!task) 3331 goto out; 3332 if (!same_thread_group(leader, task)) 3333 goto out_drop_task; 3334 3335 result = proc_task_instantiate(dir, dentry, task, NULL); 3336 out_drop_task: 3337 put_task_struct(task); 3338 out: 3339 put_task_struct(leader); 3340 out_no_task: 3341 return result; 3342 } 3343 3344 /* 3345 * Find the first tid of a thread group to return to user space. 3346 * 3347 * Usually this is just the thread group leader, but if the users 3348 * buffer was too small or there was a seek into the middle of the 3349 * directory we have more work todo. 3350 * 3351 * In the case of a short read we start with find_task_by_pid. 3352 * 3353 * In the case of a seek we start with the leader and walk nr 3354 * threads past it. 3355 */ 3356 static struct task_struct *first_tid(struct task_struct *leader, 3357 int tid, int nr, struct pid_namespace *ns) 3358 { 3359 struct task_struct *pos; 3360 3361 rcu_read_lock(); 3362 /* Attempt to start with the pid of a thread */ 3363 if (tid && (nr > 0)) { 3364 pos = find_task_by_pid_ns(tid, ns); 3365 if (pos && (pos->group_leader == leader)) 3366 goto found; 3367 } 3368 3369 /* If nr exceeds the number of threads there is nothing todo */ 3370 pos = NULL; 3371 if (nr && nr >= get_nr_threads(leader)) 3372 goto out; 3373 3374 /* If we haven't found our starting place yet start 3375 * with the leader and walk nr threads forward. 3376 */ 3377 for (pos = leader; nr > 0; --nr) { 3378 pos = next_thread(pos); 3379 if (pos == leader) { 3380 pos = NULL; 3381 goto out; 3382 } 3383 } 3384 found: 3385 get_task_struct(pos); 3386 out: 3387 rcu_read_unlock(); 3388 return pos; 3389 } 3390 3391 /* 3392 * Find the next thread in the thread list. 3393 * Return NULL if there is an error or no next thread. 3394 * 3395 * The reference to the input task_struct is released. 3396 */ 3397 static struct task_struct *next_tid(struct task_struct *start) 3398 { 3399 struct task_struct *pos = NULL; 3400 rcu_read_lock(); 3401 if (pid_alive(start)) { 3402 pos = next_thread(start); 3403 if (thread_group_leader(pos)) 3404 pos = NULL; 3405 else 3406 get_task_struct(pos); 3407 } 3408 rcu_read_unlock(); 3409 put_task_struct(start); 3410 return pos; 3411 } 3412 3413 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3414 struct task_struct *task, int tid) 3415 { 3416 char name[PROC_NUMBUF]; 3417 int len = snprintf(name, sizeof(name), "%d", tid); 3418 return proc_fill_cache(filp, dirent, filldir, name, len, 3419 proc_task_instantiate, task, NULL); 3420 } 3421 3422 /* for the /proc/TGID/task/ directories */ 3423 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 3424 { 3425 struct dentry *dentry = filp->f_path.dentry; 3426 struct inode *inode = dentry->d_inode; 3427 struct task_struct *leader = NULL; 3428 struct task_struct *task; 3429 int retval = -ENOENT; 3430 ino_t ino; 3431 int tid; 3432 struct pid_namespace *ns; 3433 3434 task = get_proc_task(inode); 3435 if (!task) 3436 goto out_no_task; 3437 rcu_read_lock(); 3438 if (pid_alive(task)) { 3439 leader = task->group_leader; 3440 get_task_struct(leader); 3441 } 3442 rcu_read_unlock(); 3443 put_task_struct(task); 3444 if (!leader) 3445 goto out_no_task; 3446 retval = 0; 3447 3448 switch ((unsigned long)filp->f_pos) { 3449 case 0: 3450 ino = inode->i_ino; 3451 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0) 3452 goto out; 3453 filp->f_pos++; 3454 /* fall through */ 3455 case 1: 3456 ino = parent_ino(dentry); 3457 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0) 3458 goto out; 3459 filp->f_pos++; 3460 /* fall through */ 3461 } 3462 3463 /* f_version caches the tgid value that the last readdir call couldn't 3464 * return. lseek aka telldir automagically resets f_version to 0. 3465 */ 3466 ns = filp->f_dentry->d_sb->s_fs_info; 3467 tid = (int)filp->f_version; 3468 filp->f_version = 0; 3469 for (task = first_tid(leader, tid, filp->f_pos - 2, ns); 3470 task; 3471 task = next_tid(task), filp->f_pos++) { 3472 tid = task_pid_nr_ns(task, ns); 3473 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 3474 /* returning this tgid failed, save it as the first 3475 * pid for the next readir call */ 3476 filp->f_version = (u64)tid; 3477 put_task_struct(task); 3478 break; 3479 } 3480 } 3481 out: 3482 put_task_struct(leader); 3483 out_no_task: 3484 return retval; 3485 } 3486 3487 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3488 { 3489 struct inode *inode = dentry->d_inode; 3490 struct task_struct *p = get_proc_task(inode); 3491 generic_fillattr(inode, stat); 3492 3493 if (p) { 3494 stat->nlink += get_nr_threads(p); 3495 put_task_struct(p); 3496 } 3497 3498 return 0; 3499 } 3500 3501 static const struct inode_operations proc_task_inode_operations = { 3502 .lookup = proc_task_lookup, 3503 .getattr = proc_task_getattr, 3504 .setattr = proc_setattr, 3505 }; 3506 3507 static const struct file_operations proc_task_operations = { 3508 .read = generic_read_dir, 3509 .readdir = proc_task_readdir, 3510 .llseek = default_llseek, 3511 }; 3512