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 const struct inode_operations proc_pid_link_inode_operations = { 1656 .readlink = proc_pid_readlink, 1657 .follow_link = proc_pid_follow_link, 1658 .setattr = proc_setattr, 1659 }; 1660 1661 1662 /* building an inode */ 1663 1664 static int task_dumpable(struct task_struct *task) 1665 { 1666 int dumpable = 0; 1667 struct mm_struct *mm; 1668 1669 task_lock(task); 1670 mm = task->mm; 1671 if (mm) 1672 dumpable = get_dumpable(mm); 1673 task_unlock(task); 1674 if(dumpable == 1) 1675 return 1; 1676 return 0; 1677 } 1678 1679 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1680 { 1681 struct inode * inode; 1682 struct proc_inode *ei; 1683 const struct cred *cred; 1684 1685 /* We need a new inode */ 1686 1687 inode = new_inode(sb); 1688 if (!inode) 1689 goto out; 1690 1691 /* Common stuff */ 1692 ei = PROC_I(inode); 1693 inode->i_ino = get_next_ino(); 1694 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1695 inode->i_op = &proc_def_inode_operations; 1696 1697 /* 1698 * grab the reference to task. 1699 */ 1700 ei->pid = get_task_pid(task, PIDTYPE_PID); 1701 if (!ei->pid) 1702 goto out_unlock; 1703 1704 if (task_dumpable(task)) { 1705 rcu_read_lock(); 1706 cred = __task_cred(task); 1707 inode->i_uid = cred->euid; 1708 inode->i_gid = cred->egid; 1709 rcu_read_unlock(); 1710 } 1711 security_task_to_inode(task, inode); 1712 1713 out: 1714 return inode; 1715 1716 out_unlock: 1717 iput(inode); 1718 return NULL; 1719 } 1720 1721 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1722 { 1723 struct inode *inode = dentry->d_inode; 1724 struct task_struct *task; 1725 const struct cred *cred; 1726 1727 generic_fillattr(inode, stat); 1728 1729 rcu_read_lock(); 1730 stat->uid = 0; 1731 stat->gid = 0; 1732 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1733 if (task) { 1734 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1735 task_dumpable(task)) { 1736 cred = __task_cred(task); 1737 stat->uid = cred->euid; 1738 stat->gid = cred->egid; 1739 } 1740 } 1741 rcu_read_unlock(); 1742 return 0; 1743 } 1744 1745 /* dentry stuff */ 1746 1747 /* 1748 * Exceptional case: normally we are not allowed to unhash a busy 1749 * directory. In this case, however, we can do it - no aliasing problems 1750 * due to the way we treat inodes. 1751 * 1752 * Rewrite the inode's ownerships here because the owning task may have 1753 * performed a setuid(), etc. 1754 * 1755 * Before the /proc/pid/status file was created the only way to read 1756 * the effective uid of a /process was to stat /proc/pid. Reading 1757 * /proc/pid/status is slow enough that procps and other packages 1758 * kept stating /proc/pid. To keep the rules in /proc simple I have 1759 * made this apply to all per process world readable and executable 1760 * directories. 1761 */ 1762 int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1763 { 1764 struct inode *inode; 1765 struct task_struct *task; 1766 const struct cred *cred; 1767 1768 if (nd && nd->flags & LOOKUP_RCU) 1769 return -ECHILD; 1770 1771 inode = dentry->d_inode; 1772 task = get_proc_task(inode); 1773 1774 if (task) { 1775 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1776 task_dumpable(task)) { 1777 rcu_read_lock(); 1778 cred = __task_cred(task); 1779 inode->i_uid = cred->euid; 1780 inode->i_gid = cred->egid; 1781 rcu_read_unlock(); 1782 } else { 1783 inode->i_uid = 0; 1784 inode->i_gid = 0; 1785 } 1786 inode->i_mode &= ~(S_ISUID | S_ISGID); 1787 security_task_to_inode(task, inode); 1788 put_task_struct(task); 1789 return 1; 1790 } 1791 d_drop(dentry); 1792 return 0; 1793 } 1794 1795 static int pid_delete_dentry(const struct dentry * dentry) 1796 { 1797 /* Is the task we represent dead? 1798 * If so, then don't put the dentry on the lru list, 1799 * kill it immediately. 1800 */ 1801 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1802 } 1803 1804 const struct dentry_operations pid_dentry_operations = 1805 { 1806 .d_revalidate = pid_revalidate, 1807 .d_delete = pid_delete_dentry, 1808 }; 1809 1810 /* Lookups */ 1811 1812 /* 1813 * Fill a directory entry. 1814 * 1815 * If possible create the dcache entry and derive our inode number and 1816 * file type from dcache entry. 1817 * 1818 * Since all of the proc inode numbers are dynamically generated, the inode 1819 * numbers do not exist until the inode is cache. This means creating the 1820 * the dcache entry in readdir is necessary to keep the inode numbers 1821 * reported by readdir in sync with the inode numbers reported 1822 * by stat. 1823 */ 1824 int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1825 const char *name, int len, 1826 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1827 { 1828 struct dentry *child, *dir = filp->f_path.dentry; 1829 struct inode *inode; 1830 struct qstr qname; 1831 ino_t ino = 0; 1832 unsigned type = DT_UNKNOWN; 1833 1834 qname.name = name; 1835 qname.len = len; 1836 qname.hash = full_name_hash(name, len); 1837 1838 child = d_lookup(dir, &qname); 1839 if (!child) { 1840 struct dentry *new; 1841 new = d_alloc(dir, &qname); 1842 if (new) { 1843 child = instantiate(dir->d_inode, new, task, ptr); 1844 if (child) 1845 dput(new); 1846 else 1847 child = new; 1848 } 1849 } 1850 if (!child || IS_ERR(child) || !child->d_inode) 1851 goto end_instantiate; 1852 inode = child->d_inode; 1853 if (inode) { 1854 ino = inode->i_ino; 1855 type = inode->i_mode >> 12; 1856 } 1857 dput(child); 1858 end_instantiate: 1859 if (!ino) 1860 ino = find_inode_number(dir, &qname); 1861 if (!ino) 1862 ino = 1; 1863 return filldir(dirent, name, len, filp->f_pos, ino, type); 1864 } 1865 1866 static unsigned name_to_int(struct dentry *dentry) 1867 { 1868 const char *name = dentry->d_name.name; 1869 int len = dentry->d_name.len; 1870 unsigned n = 0; 1871 1872 if (len > 1 && *name == '0') 1873 goto out; 1874 while (len-- > 0) { 1875 unsigned c = *name++ - '0'; 1876 if (c > 9) 1877 goto out; 1878 if (n >= (~0U-9)/10) 1879 goto out; 1880 n *= 10; 1881 n += c; 1882 } 1883 return n; 1884 out: 1885 return ~0U; 1886 } 1887 1888 #define PROC_FDINFO_MAX 64 1889 1890 static int proc_fd_info(struct inode *inode, struct path *path, char *info) 1891 { 1892 struct task_struct *task = get_proc_task(inode); 1893 struct files_struct *files = NULL; 1894 struct file *file; 1895 int fd = proc_fd(inode); 1896 1897 if (task) { 1898 files = get_files_struct(task); 1899 put_task_struct(task); 1900 } 1901 if (files) { 1902 /* 1903 * We are not taking a ref to the file structure, so we must 1904 * hold ->file_lock. 1905 */ 1906 spin_lock(&files->file_lock); 1907 file = fcheck_files(files, fd); 1908 if (file) { 1909 unsigned int f_flags; 1910 struct fdtable *fdt; 1911 1912 fdt = files_fdtable(files); 1913 f_flags = file->f_flags & ~O_CLOEXEC; 1914 if (FD_ISSET(fd, fdt->close_on_exec)) 1915 f_flags |= O_CLOEXEC; 1916 1917 if (path) { 1918 *path = file->f_path; 1919 path_get(&file->f_path); 1920 } 1921 if (info) 1922 snprintf(info, PROC_FDINFO_MAX, 1923 "pos:\t%lli\n" 1924 "flags:\t0%o\n", 1925 (long long) file->f_pos, 1926 f_flags); 1927 spin_unlock(&files->file_lock); 1928 put_files_struct(files); 1929 return 0; 1930 } 1931 spin_unlock(&files->file_lock); 1932 put_files_struct(files); 1933 } 1934 return -ENOENT; 1935 } 1936 1937 static int proc_fd_link(struct inode *inode, struct path *path) 1938 { 1939 return proc_fd_info(inode, path, NULL); 1940 } 1941 1942 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1943 { 1944 struct inode *inode; 1945 struct task_struct *task; 1946 int fd; 1947 struct files_struct *files; 1948 const struct cred *cred; 1949 1950 if (nd && nd->flags & LOOKUP_RCU) 1951 return -ECHILD; 1952 1953 inode = dentry->d_inode; 1954 task = get_proc_task(inode); 1955 fd = proc_fd(inode); 1956 1957 if (task) { 1958 files = get_files_struct(task); 1959 if (files) { 1960 rcu_read_lock(); 1961 if (fcheck_files(files, fd)) { 1962 rcu_read_unlock(); 1963 put_files_struct(files); 1964 if (task_dumpable(task)) { 1965 rcu_read_lock(); 1966 cred = __task_cred(task); 1967 inode->i_uid = cred->euid; 1968 inode->i_gid = cred->egid; 1969 rcu_read_unlock(); 1970 } else { 1971 inode->i_uid = 0; 1972 inode->i_gid = 0; 1973 } 1974 inode->i_mode &= ~(S_ISUID | S_ISGID); 1975 security_task_to_inode(task, inode); 1976 put_task_struct(task); 1977 return 1; 1978 } 1979 rcu_read_unlock(); 1980 put_files_struct(files); 1981 } 1982 put_task_struct(task); 1983 } 1984 d_drop(dentry); 1985 return 0; 1986 } 1987 1988 static const struct dentry_operations tid_fd_dentry_operations = 1989 { 1990 .d_revalidate = tid_fd_revalidate, 1991 .d_delete = pid_delete_dentry, 1992 }; 1993 1994 static struct dentry *proc_fd_instantiate(struct inode *dir, 1995 struct dentry *dentry, struct task_struct *task, const void *ptr) 1996 { 1997 unsigned fd = *(const unsigned *)ptr; 1998 struct file *file; 1999 struct files_struct *files; 2000 struct inode *inode; 2001 struct proc_inode *ei; 2002 struct dentry *error = ERR_PTR(-ENOENT); 2003 2004 inode = proc_pid_make_inode(dir->i_sb, task); 2005 if (!inode) 2006 goto out; 2007 ei = PROC_I(inode); 2008 ei->fd = fd; 2009 files = get_files_struct(task); 2010 if (!files) 2011 goto out_iput; 2012 inode->i_mode = S_IFLNK; 2013 2014 /* 2015 * We are not taking a ref to the file structure, so we must 2016 * hold ->file_lock. 2017 */ 2018 spin_lock(&files->file_lock); 2019 file = fcheck_files(files, fd); 2020 if (!file) 2021 goto out_unlock; 2022 if (file->f_mode & FMODE_READ) 2023 inode->i_mode |= S_IRUSR | S_IXUSR; 2024 if (file->f_mode & FMODE_WRITE) 2025 inode->i_mode |= S_IWUSR | S_IXUSR; 2026 spin_unlock(&files->file_lock); 2027 put_files_struct(files); 2028 2029 inode->i_op = &proc_pid_link_inode_operations; 2030 inode->i_size = 64; 2031 ei->op.proc_get_link = proc_fd_link; 2032 d_set_d_op(dentry, &tid_fd_dentry_operations); 2033 d_add(dentry, inode); 2034 /* Close the race of the process dying before we return the dentry */ 2035 if (tid_fd_revalidate(dentry, NULL)) 2036 error = NULL; 2037 2038 out: 2039 return error; 2040 out_unlock: 2041 spin_unlock(&files->file_lock); 2042 put_files_struct(files); 2043 out_iput: 2044 iput(inode); 2045 goto out; 2046 } 2047 2048 static struct dentry *proc_lookupfd_common(struct inode *dir, 2049 struct dentry *dentry, 2050 instantiate_t instantiate) 2051 { 2052 struct task_struct *task = get_proc_task(dir); 2053 unsigned fd = name_to_int(dentry); 2054 struct dentry *result = ERR_PTR(-ENOENT); 2055 2056 if (!task) 2057 goto out_no_task; 2058 if (fd == ~0U) 2059 goto out; 2060 2061 result = instantiate(dir, dentry, task, &fd); 2062 out: 2063 put_task_struct(task); 2064 out_no_task: 2065 return result; 2066 } 2067 2068 static int proc_readfd_common(struct file * filp, void * dirent, 2069 filldir_t filldir, instantiate_t instantiate) 2070 { 2071 struct dentry *dentry = filp->f_path.dentry; 2072 struct inode *inode = dentry->d_inode; 2073 struct task_struct *p = get_proc_task(inode); 2074 unsigned int fd, ino; 2075 int retval; 2076 struct files_struct * files; 2077 2078 retval = -ENOENT; 2079 if (!p) 2080 goto out_no_task; 2081 retval = 0; 2082 2083 fd = filp->f_pos; 2084 switch (fd) { 2085 case 0: 2086 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 2087 goto out; 2088 filp->f_pos++; 2089 case 1: 2090 ino = parent_ino(dentry); 2091 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 2092 goto out; 2093 filp->f_pos++; 2094 default: 2095 files = get_files_struct(p); 2096 if (!files) 2097 goto out; 2098 rcu_read_lock(); 2099 for (fd = filp->f_pos-2; 2100 fd < files_fdtable(files)->max_fds; 2101 fd++, filp->f_pos++) { 2102 char name[PROC_NUMBUF]; 2103 int len; 2104 2105 if (!fcheck_files(files, fd)) 2106 continue; 2107 rcu_read_unlock(); 2108 2109 len = snprintf(name, sizeof(name), "%d", fd); 2110 if (proc_fill_cache(filp, dirent, filldir, 2111 name, len, instantiate, 2112 p, &fd) < 0) { 2113 rcu_read_lock(); 2114 break; 2115 } 2116 rcu_read_lock(); 2117 } 2118 rcu_read_unlock(); 2119 put_files_struct(files); 2120 } 2121 out: 2122 put_task_struct(p); 2123 out_no_task: 2124 return retval; 2125 } 2126 2127 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 2128 struct nameidata *nd) 2129 { 2130 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 2131 } 2132 2133 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 2134 { 2135 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 2136 } 2137 2138 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 2139 size_t len, loff_t *ppos) 2140 { 2141 char tmp[PROC_FDINFO_MAX]; 2142 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); 2143 if (!err) 2144 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 2145 return err; 2146 } 2147 2148 static const struct file_operations proc_fdinfo_file_operations = { 2149 .open = nonseekable_open, 2150 .read = proc_fdinfo_read, 2151 .llseek = no_llseek, 2152 }; 2153 2154 static const struct file_operations proc_fd_operations = { 2155 .read = generic_read_dir, 2156 .readdir = proc_readfd, 2157 .llseek = default_llseek, 2158 }; 2159 2160 /* 2161 * /proc/pid/fd needs a special permission handler so that a process can still 2162 * access /proc/self/fd after it has executed a setuid(). 2163 */ 2164 static int proc_fd_permission(struct inode *inode, int mask) 2165 { 2166 int rv = generic_permission(inode, mask); 2167 if (rv == 0) 2168 return 0; 2169 if (task_pid(current) == proc_pid(inode)) 2170 rv = 0; 2171 return rv; 2172 } 2173 2174 /* 2175 * proc directories can do almost nothing.. 2176 */ 2177 static const struct inode_operations proc_fd_inode_operations = { 2178 .lookup = proc_lookupfd, 2179 .permission = proc_fd_permission, 2180 .setattr = proc_setattr, 2181 }; 2182 2183 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 2184 struct dentry *dentry, struct task_struct *task, const void *ptr) 2185 { 2186 unsigned fd = *(unsigned *)ptr; 2187 struct inode *inode; 2188 struct proc_inode *ei; 2189 struct dentry *error = ERR_PTR(-ENOENT); 2190 2191 inode = proc_pid_make_inode(dir->i_sb, task); 2192 if (!inode) 2193 goto out; 2194 ei = PROC_I(inode); 2195 ei->fd = fd; 2196 inode->i_mode = S_IFREG | S_IRUSR; 2197 inode->i_fop = &proc_fdinfo_file_operations; 2198 d_set_d_op(dentry, &tid_fd_dentry_operations); 2199 d_add(dentry, inode); 2200 /* Close the race of the process dying before we return the dentry */ 2201 if (tid_fd_revalidate(dentry, NULL)) 2202 error = NULL; 2203 2204 out: 2205 return error; 2206 } 2207 2208 static struct dentry *proc_lookupfdinfo(struct inode *dir, 2209 struct dentry *dentry, 2210 struct nameidata *nd) 2211 { 2212 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 2213 } 2214 2215 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 2216 { 2217 return proc_readfd_common(filp, dirent, filldir, 2218 proc_fdinfo_instantiate); 2219 } 2220 2221 static const struct file_operations proc_fdinfo_operations = { 2222 .read = generic_read_dir, 2223 .readdir = proc_readfdinfo, 2224 .llseek = default_llseek, 2225 }; 2226 2227 /* 2228 * proc directories can do almost nothing.. 2229 */ 2230 static const struct inode_operations proc_fdinfo_inode_operations = { 2231 .lookup = proc_lookupfdinfo, 2232 .setattr = proc_setattr, 2233 }; 2234 2235 2236 static struct dentry *proc_pident_instantiate(struct inode *dir, 2237 struct dentry *dentry, struct task_struct *task, const void *ptr) 2238 { 2239 const struct pid_entry *p = ptr; 2240 struct inode *inode; 2241 struct proc_inode *ei; 2242 struct dentry *error = ERR_PTR(-ENOENT); 2243 2244 inode = proc_pid_make_inode(dir->i_sb, task); 2245 if (!inode) 2246 goto out; 2247 2248 ei = PROC_I(inode); 2249 inode->i_mode = p->mode; 2250 if (S_ISDIR(inode->i_mode)) 2251 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2252 if (p->iop) 2253 inode->i_op = p->iop; 2254 if (p->fop) 2255 inode->i_fop = p->fop; 2256 ei->op = p->op; 2257 d_set_d_op(dentry, &pid_dentry_operations); 2258 d_add(dentry, inode); 2259 /* Close the race of the process dying before we return the dentry */ 2260 if (pid_revalidate(dentry, NULL)) 2261 error = NULL; 2262 out: 2263 return error; 2264 } 2265 2266 static struct dentry *proc_pident_lookup(struct inode *dir, 2267 struct dentry *dentry, 2268 const struct pid_entry *ents, 2269 unsigned int nents) 2270 { 2271 struct dentry *error; 2272 struct task_struct *task = get_proc_task(dir); 2273 const struct pid_entry *p, *last; 2274 2275 error = ERR_PTR(-ENOENT); 2276 2277 if (!task) 2278 goto out_no_task; 2279 2280 /* 2281 * Yes, it does not scale. And it should not. Don't add 2282 * new entries into /proc/<tgid>/ without very good reasons. 2283 */ 2284 last = &ents[nents - 1]; 2285 for (p = ents; p <= last; p++) { 2286 if (p->len != dentry->d_name.len) 2287 continue; 2288 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2289 break; 2290 } 2291 if (p > last) 2292 goto out; 2293 2294 error = proc_pident_instantiate(dir, dentry, task, p); 2295 out: 2296 put_task_struct(task); 2297 out_no_task: 2298 return error; 2299 } 2300 2301 static int proc_pident_fill_cache(struct file *filp, void *dirent, 2302 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2303 { 2304 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2305 proc_pident_instantiate, task, p); 2306 } 2307 2308 static int proc_pident_readdir(struct file *filp, 2309 void *dirent, filldir_t filldir, 2310 const struct pid_entry *ents, unsigned int nents) 2311 { 2312 int i; 2313 struct dentry *dentry = filp->f_path.dentry; 2314 struct inode *inode = dentry->d_inode; 2315 struct task_struct *task = get_proc_task(inode); 2316 const struct pid_entry *p, *last; 2317 ino_t ino; 2318 int ret; 2319 2320 ret = -ENOENT; 2321 if (!task) 2322 goto out_no_task; 2323 2324 ret = 0; 2325 i = filp->f_pos; 2326 switch (i) { 2327 case 0: 2328 ino = inode->i_ino; 2329 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 2330 goto out; 2331 i++; 2332 filp->f_pos++; 2333 /* fall through */ 2334 case 1: 2335 ino = parent_ino(dentry); 2336 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 2337 goto out; 2338 i++; 2339 filp->f_pos++; 2340 /* fall through */ 2341 default: 2342 i -= 2; 2343 if (i >= nents) { 2344 ret = 1; 2345 goto out; 2346 } 2347 p = ents + i; 2348 last = &ents[nents - 1]; 2349 while (p <= last) { 2350 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2351 goto out; 2352 filp->f_pos++; 2353 p++; 2354 } 2355 } 2356 2357 ret = 1; 2358 out: 2359 put_task_struct(task); 2360 out_no_task: 2361 return ret; 2362 } 2363 2364 #ifdef CONFIG_SECURITY 2365 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2366 size_t count, loff_t *ppos) 2367 { 2368 struct inode * inode = file->f_path.dentry->d_inode; 2369 char *p = NULL; 2370 ssize_t length; 2371 struct task_struct *task = get_proc_task(inode); 2372 2373 if (!task) 2374 return -ESRCH; 2375 2376 length = security_getprocattr(task, 2377 (char*)file->f_path.dentry->d_name.name, 2378 &p); 2379 put_task_struct(task); 2380 if (length > 0) 2381 length = simple_read_from_buffer(buf, count, ppos, p, length); 2382 kfree(p); 2383 return length; 2384 } 2385 2386 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2387 size_t count, loff_t *ppos) 2388 { 2389 struct inode * inode = file->f_path.dentry->d_inode; 2390 char *page; 2391 ssize_t length; 2392 struct task_struct *task = get_proc_task(inode); 2393 2394 length = -ESRCH; 2395 if (!task) 2396 goto out_no_task; 2397 if (count > PAGE_SIZE) 2398 count = PAGE_SIZE; 2399 2400 /* No partial writes. */ 2401 length = -EINVAL; 2402 if (*ppos != 0) 2403 goto out; 2404 2405 length = -ENOMEM; 2406 page = (char*)__get_free_page(GFP_TEMPORARY); 2407 if (!page) 2408 goto out; 2409 2410 length = -EFAULT; 2411 if (copy_from_user(page, buf, count)) 2412 goto out_free; 2413 2414 /* Guard against adverse ptrace interaction */ 2415 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex); 2416 if (length < 0) 2417 goto out_free; 2418 2419 length = security_setprocattr(task, 2420 (char*)file->f_path.dentry->d_name.name, 2421 (void*)page, count); 2422 mutex_unlock(&task->signal->cred_guard_mutex); 2423 out_free: 2424 free_page((unsigned long) page); 2425 out: 2426 put_task_struct(task); 2427 out_no_task: 2428 return length; 2429 } 2430 2431 static const struct file_operations proc_pid_attr_operations = { 2432 .read = proc_pid_attr_read, 2433 .write = proc_pid_attr_write, 2434 .llseek = generic_file_llseek, 2435 }; 2436 2437 static const struct pid_entry attr_dir_stuff[] = { 2438 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2439 REG("prev", S_IRUGO, proc_pid_attr_operations), 2440 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2441 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2442 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2443 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2444 }; 2445 2446 static int proc_attr_dir_readdir(struct file * filp, 2447 void * dirent, filldir_t filldir) 2448 { 2449 return proc_pident_readdir(filp,dirent,filldir, 2450 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2451 } 2452 2453 static const struct file_operations proc_attr_dir_operations = { 2454 .read = generic_read_dir, 2455 .readdir = proc_attr_dir_readdir, 2456 .llseek = default_llseek, 2457 }; 2458 2459 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2460 struct dentry *dentry, struct nameidata *nd) 2461 { 2462 return proc_pident_lookup(dir, dentry, 2463 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2464 } 2465 2466 static const struct inode_operations proc_attr_dir_inode_operations = { 2467 .lookup = proc_attr_dir_lookup, 2468 .getattr = pid_getattr, 2469 .setattr = proc_setattr, 2470 }; 2471 2472 #endif 2473 2474 #ifdef CONFIG_ELF_CORE 2475 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2476 size_t count, loff_t *ppos) 2477 { 2478 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2479 struct mm_struct *mm; 2480 char buffer[PROC_NUMBUF]; 2481 size_t len; 2482 int ret; 2483 2484 if (!task) 2485 return -ESRCH; 2486 2487 ret = 0; 2488 mm = get_task_mm(task); 2489 if (mm) { 2490 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2491 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2492 MMF_DUMP_FILTER_SHIFT)); 2493 mmput(mm); 2494 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2495 } 2496 2497 put_task_struct(task); 2498 2499 return ret; 2500 } 2501 2502 static ssize_t proc_coredump_filter_write(struct file *file, 2503 const char __user *buf, 2504 size_t count, 2505 loff_t *ppos) 2506 { 2507 struct task_struct *task; 2508 struct mm_struct *mm; 2509 char buffer[PROC_NUMBUF], *end; 2510 unsigned int val; 2511 int ret; 2512 int i; 2513 unsigned long mask; 2514 2515 ret = -EFAULT; 2516 memset(buffer, 0, sizeof(buffer)); 2517 if (count > sizeof(buffer) - 1) 2518 count = sizeof(buffer) - 1; 2519 if (copy_from_user(buffer, buf, count)) 2520 goto out_no_task; 2521 2522 ret = -EINVAL; 2523 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2524 if (*end == '\n') 2525 end++; 2526 if (end - buffer == 0) 2527 goto out_no_task; 2528 2529 ret = -ESRCH; 2530 task = get_proc_task(file->f_dentry->d_inode); 2531 if (!task) 2532 goto out_no_task; 2533 2534 ret = end - buffer; 2535 mm = get_task_mm(task); 2536 if (!mm) 2537 goto out_no_mm; 2538 2539 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2540 if (val & mask) 2541 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2542 else 2543 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2544 } 2545 2546 mmput(mm); 2547 out_no_mm: 2548 put_task_struct(task); 2549 out_no_task: 2550 return ret; 2551 } 2552 2553 static const struct file_operations proc_coredump_filter_operations = { 2554 .read = proc_coredump_filter_read, 2555 .write = proc_coredump_filter_write, 2556 .llseek = generic_file_llseek, 2557 }; 2558 #endif 2559 2560 /* 2561 * /proc/self: 2562 */ 2563 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2564 int buflen) 2565 { 2566 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2567 pid_t tgid = task_tgid_nr_ns(current, ns); 2568 char tmp[PROC_NUMBUF]; 2569 if (!tgid) 2570 return -ENOENT; 2571 sprintf(tmp, "%d", tgid); 2572 return vfs_readlink(dentry,buffer,buflen,tmp); 2573 } 2574 2575 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2576 { 2577 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2578 pid_t tgid = task_tgid_nr_ns(current, ns); 2579 char *name = ERR_PTR(-ENOENT); 2580 if (tgid) { 2581 name = __getname(); 2582 if (!name) 2583 name = ERR_PTR(-ENOMEM); 2584 else 2585 sprintf(name, "%d", tgid); 2586 } 2587 nd_set_link(nd, name); 2588 return NULL; 2589 } 2590 2591 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd, 2592 void *cookie) 2593 { 2594 char *s = nd_get_link(nd); 2595 if (!IS_ERR(s)) 2596 __putname(s); 2597 } 2598 2599 static const struct inode_operations proc_self_inode_operations = { 2600 .readlink = proc_self_readlink, 2601 .follow_link = proc_self_follow_link, 2602 .put_link = proc_self_put_link, 2603 }; 2604 2605 /* 2606 * proc base 2607 * 2608 * These are the directory entries in the root directory of /proc 2609 * that properly belong to the /proc filesystem, as they describe 2610 * describe something that is process related. 2611 */ 2612 static const struct pid_entry proc_base_stuff[] = { 2613 NOD("self", S_IFLNK|S_IRWXUGO, 2614 &proc_self_inode_operations, NULL, {}), 2615 }; 2616 2617 static struct dentry *proc_base_instantiate(struct inode *dir, 2618 struct dentry *dentry, struct task_struct *task, const void *ptr) 2619 { 2620 const struct pid_entry *p = ptr; 2621 struct inode *inode; 2622 struct proc_inode *ei; 2623 struct dentry *error; 2624 2625 /* Allocate the inode */ 2626 error = ERR_PTR(-ENOMEM); 2627 inode = new_inode(dir->i_sb); 2628 if (!inode) 2629 goto out; 2630 2631 /* Initialize the inode */ 2632 ei = PROC_I(inode); 2633 inode->i_ino = get_next_ino(); 2634 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2635 2636 /* 2637 * grab the reference to the task. 2638 */ 2639 ei->pid = get_task_pid(task, PIDTYPE_PID); 2640 if (!ei->pid) 2641 goto out_iput; 2642 2643 inode->i_mode = p->mode; 2644 if (S_ISDIR(inode->i_mode)) 2645 set_nlink(inode, 2); 2646 if (S_ISLNK(inode->i_mode)) 2647 inode->i_size = 64; 2648 if (p->iop) 2649 inode->i_op = p->iop; 2650 if (p->fop) 2651 inode->i_fop = p->fop; 2652 ei->op = p->op; 2653 d_add(dentry, inode); 2654 error = NULL; 2655 out: 2656 return error; 2657 out_iput: 2658 iput(inode); 2659 goto out; 2660 } 2661 2662 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2663 { 2664 struct dentry *error; 2665 struct task_struct *task = get_proc_task(dir); 2666 const struct pid_entry *p, *last; 2667 2668 error = ERR_PTR(-ENOENT); 2669 2670 if (!task) 2671 goto out_no_task; 2672 2673 /* Lookup the directory entry */ 2674 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2675 for (p = proc_base_stuff; p <= last; p++) { 2676 if (p->len != dentry->d_name.len) 2677 continue; 2678 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2679 break; 2680 } 2681 if (p > last) 2682 goto out; 2683 2684 error = proc_base_instantiate(dir, dentry, task, p); 2685 2686 out: 2687 put_task_struct(task); 2688 out_no_task: 2689 return error; 2690 } 2691 2692 static int proc_base_fill_cache(struct file *filp, void *dirent, 2693 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2694 { 2695 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2696 proc_base_instantiate, task, p); 2697 } 2698 2699 #ifdef CONFIG_TASK_IO_ACCOUNTING 2700 static int do_io_accounting(struct task_struct *task, char *buffer, int whole) 2701 { 2702 struct task_io_accounting acct = task->ioac; 2703 unsigned long flags; 2704 int result; 2705 2706 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2707 if (result) 2708 return result; 2709 2710 if (!ptrace_may_access(task, PTRACE_MODE_READ)) { 2711 result = -EACCES; 2712 goto out_unlock; 2713 } 2714 2715 if (whole && lock_task_sighand(task, &flags)) { 2716 struct task_struct *t = task; 2717 2718 task_io_accounting_add(&acct, &task->signal->ioac); 2719 while_each_thread(task, t) 2720 task_io_accounting_add(&acct, &t->ioac); 2721 2722 unlock_task_sighand(task, &flags); 2723 } 2724 result = sprintf(buffer, 2725 "rchar: %llu\n" 2726 "wchar: %llu\n" 2727 "syscr: %llu\n" 2728 "syscw: %llu\n" 2729 "read_bytes: %llu\n" 2730 "write_bytes: %llu\n" 2731 "cancelled_write_bytes: %llu\n", 2732 (unsigned long long)acct.rchar, 2733 (unsigned long long)acct.wchar, 2734 (unsigned long long)acct.syscr, 2735 (unsigned long long)acct.syscw, 2736 (unsigned long long)acct.read_bytes, 2737 (unsigned long long)acct.write_bytes, 2738 (unsigned long long)acct.cancelled_write_bytes); 2739 out_unlock: 2740 mutex_unlock(&task->signal->cred_guard_mutex); 2741 return result; 2742 } 2743 2744 static int proc_tid_io_accounting(struct task_struct *task, char *buffer) 2745 { 2746 return do_io_accounting(task, buffer, 0); 2747 } 2748 2749 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer) 2750 { 2751 return do_io_accounting(task, buffer, 1); 2752 } 2753 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2754 2755 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2756 struct pid *pid, struct task_struct *task) 2757 { 2758 int err = lock_trace(task); 2759 if (!err) { 2760 seq_printf(m, "%08x\n", task->personality); 2761 unlock_trace(task); 2762 } 2763 return err; 2764 } 2765 2766 /* 2767 * Thread groups 2768 */ 2769 static const struct file_operations proc_task_operations; 2770 static const struct inode_operations proc_task_inode_operations; 2771 2772 static const struct pid_entry tgid_base_stuff[] = { 2773 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2774 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2775 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2776 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2777 #ifdef CONFIG_NET 2778 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2779 #endif 2780 REG("environ", S_IRUSR, proc_environ_operations), 2781 INF("auxv", S_IRUSR, proc_pid_auxv), 2782 ONE("status", S_IRUGO, proc_pid_status), 2783 ONE("personality", S_IRUGO, proc_pid_personality), 2784 INF("limits", S_IRUGO, proc_pid_limits), 2785 #ifdef CONFIG_SCHED_DEBUG 2786 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2787 #endif 2788 #ifdef CONFIG_SCHED_AUTOGROUP 2789 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2790 #endif 2791 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2792 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2793 INF("syscall", S_IRUGO, proc_pid_syscall), 2794 #endif 2795 INF("cmdline", S_IRUGO, proc_pid_cmdline), 2796 ONE("stat", S_IRUGO, proc_tgid_stat), 2797 ONE("statm", S_IRUGO, proc_pid_statm), 2798 REG("maps", S_IRUGO, proc_maps_operations), 2799 #ifdef CONFIG_NUMA 2800 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 2801 #endif 2802 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2803 LNK("cwd", proc_cwd_link), 2804 LNK("root", proc_root_link), 2805 LNK("exe", proc_exe_link), 2806 REG("mounts", S_IRUGO, proc_mounts_operations), 2807 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2808 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2809 #ifdef CONFIG_PROC_PAGE_MONITOR 2810 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2811 REG("smaps", S_IRUGO, proc_smaps_operations), 2812 REG("pagemap", S_IRUGO, proc_pagemap_operations), 2813 #endif 2814 #ifdef CONFIG_SECURITY 2815 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2816 #endif 2817 #ifdef CONFIG_KALLSYMS 2818 INF("wchan", S_IRUGO, proc_pid_wchan), 2819 #endif 2820 #ifdef CONFIG_STACKTRACE 2821 ONE("stack", S_IRUGO, proc_pid_stack), 2822 #endif 2823 #ifdef CONFIG_SCHEDSTATS 2824 INF("schedstat", S_IRUGO, proc_pid_schedstat), 2825 #endif 2826 #ifdef CONFIG_LATENCYTOP 2827 REG("latency", S_IRUGO, proc_lstats_operations), 2828 #endif 2829 #ifdef CONFIG_PROC_PID_CPUSET 2830 REG("cpuset", S_IRUGO, proc_cpuset_operations), 2831 #endif 2832 #ifdef CONFIG_CGROUPS 2833 REG("cgroup", S_IRUGO, proc_cgroup_operations), 2834 #endif 2835 INF("oom_score", S_IRUGO, proc_oom_score), 2836 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 2837 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2838 #ifdef CONFIG_AUDITSYSCALL 2839 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2840 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2841 #endif 2842 #ifdef CONFIG_FAULT_INJECTION 2843 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2844 #endif 2845 #ifdef CONFIG_ELF_CORE 2846 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2847 #endif 2848 #ifdef CONFIG_TASK_IO_ACCOUNTING 2849 INF("io", S_IRUSR, proc_tgid_io_accounting), 2850 #endif 2851 #ifdef CONFIG_HARDWALL 2852 INF("hardwall", S_IRUGO, proc_pid_hardwall), 2853 #endif 2854 }; 2855 2856 static int proc_tgid_base_readdir(struct file * filp, 2857 void * dirent, filldir_t filldir) 2858 { 2859 return proc_pident_readdir(filp,dirent,filldir, 2860 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2861 } 2862 2863 static const struct file_operations proc_tgid_base_operations = { 2864 .read = generic_read_dir, 2865 .readdir = proc_tgid_base_readdir, 2866 .llseek = default_llseek, 2867 }; 2868 2869 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2870 return proc_pident_lookup(dir, dentry, 2871 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2872 } 2873 2874 static const struct inode_operations proc_tgid_base_inode_operations = { 2875 .lookup = proc_tgid_base_lookup, 2876 .getattr = pid_getattr, 2877 .setattr = proc_setattr, 2878 }; 2879 2880 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2881 { 2882 struct dentry *dentry, *leader, *dir; 2883 char buf[PROC_NUMBUF]; 2884 struct qstr name; 2885 2886 name.name = buf; 2887 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2888 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2889 if (dentry) { 2890 shrink_dcache_parent(dentry); 2891 d_drop(dentry); 2892 dput(dentry); 2893 } 2894 2895 name.name = buf; 2896 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2897 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2898 if (!leader) 2899 goto out; 2900 2901 name.name = "task"; 2902 name.len = strlen(name.name); 2903 dir = d_hash_and_lookup(leader, &name); 2904 if (!dir) 2905 goto out_put_leader; 2906 2907 name.name = buf; 2908 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2909 dentry = d_hash_and_lookup(dir, &name); 2910 if (dentry) { 2911 shrink_dcache_parent(dentry); 2912 d_drop(dentry); 2913 dput(dentry); 2914 } 2915 2916 dput(dir); 2917 out_put_leader: 2918 dput(leader); 2919 out: 2920 return; 2921 } 2922 2923 /** 2924 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2925 * @task: task that should be flushed. 2926 * 2927 * When flushing dentries from proc, one needs to flush them from global 2928 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2929 * in. This call is supposed to do all of this job. 2930 * 2931 * Looks in the dcache for 2932 * /proc/@pid 2933 * /proc/@tgid/task/@pid 2934 * if either directory is present flushes it and all of it'ts children 2935 * from the dcache. 2936 * 2937 * It is safe and reasonable to cache /proc entries for a task until 2938 * that task exits. After that they just clog up the dcache with 2939 * useless entries, possibly causing useful dcache entries to be 2940 * flushed instead. This routine is proved to flush those useless 2941 * dcache entries at process exit time. 2942 * 2943 * NOTE: This routine is just an optimization so it does not guarantee 2944 * that no dcache entries will exist at process exit time it 2945 * just makes it very unlikely that any will persist. 2946 */ 2947 2948 void proc_flush_task(struct task_struct *task) 2949 { 2950 int i; 2951 struct pid *pid, *tgid; 2952 struct upid *upid; 2953 2954 pid = task_pid(task); 2955 tgid = task_tgid(task); 2956 2957 for (i = 0; i <= pid->level; i++) { 2958 upid = &pid->numbers[i]; 2959 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 2960 tgid->numbers[i].nr); 2961 } 2962 2963 upid = &pid->numbers[pid->level]; 2964 if (upid->nr == 1) 2965 pid_ns_release_proc(upid->ns); 2966 } 2967 2968 static struct dentry *proc_pid_instantiate(struct inode *dir, 2969 struct dentry * dentry, 2970 struct task_struct *task, const void *ptr) 2971 { 2972 struct dentry *error = ERR_PTR(-ENOENT); 2973 struct inode *inode; 2974 2975 inode = proc_pid_make_inode(dir->i_sb, task); 2976 if (!inode) 2977 goto out; 2978 2979 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2980 inode->i_op = &proc_tgid_base_inode_operations; 2981 inode->i_fop = &proc_tgid_base_operations; 2982 inode->i_flags|=S_IMMUTABLE; 2983 2984 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff, 2985 ARRAY_SIZE(tgid_base_stuff))); 2986 2987 d_set_d_op(dentry, &pid_dentry_operations); 2988 2989 d_add(dentry, inode); 2990 /* Close the race of the process dying before we return the dentry */ 2991 if (pid_revalidate(dentry, NULL)) 2992 error = NULL; 2993 out: 2994 return error; 2995 } 2996 2997 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2998 { 2999 struct dentry *result; 3000 struct task_struct *task; 3001 unsigned tgid; 3002 struct pid_namespace *ns; 3003 3004 result = proc_base_lookup(dir, dentry); 3005 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 3006 goto out; 3007 3008 tgid = name_to_int(dentry); 3009 if (tgid == ~0U) 3010 goto out; 3011 3012 ns = dentry->d_sb->s_fs_info; 3013 rcu_read_lock(); 3014 task = find_task_by_pid_ns(tgid, ns); 3015 if (task) 3016 get_task_struct(task); 3017 rcu_read_unlock(); 3018 if (!task) 3019 goto out; 3020 3021 result = proc_pid_instantiate(dir, dentry, task, NULL); 3022 put_task_struct(task); 3023 out: 3024 return result; 3025 } 3026 3027 /* 3028 * Find the first task with tgid >= tgid 3029 * 3030 */ 3031 struct tgid_iter { 3032 unsigned int tgid; 3033 struct task_struct *task; 3034 }; 3035 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3036 { 3037 struct pid *pid; 3038 3039 if (iter.task) 3040 put_task_struct(iter.task); 3041 rcu_read_lock(); 3042 retry: 3043 iter.task = NULL; 3044 pid = find_ge_pid(iter.tgid, ns); 3045 if (pid) { 3046 iter.tgid = pid_nr_ns(pid, ns); 3047 iter.task = pid_task(pid, PIDTYPE_PID); 3048 /* What we to know is if the pid we have find is the 3049 * pid of a thread_group_leader. Testing for task 3050 * being a thread_group_leader is the obvious thing 3051 * todo but there is a window when it fails, due to 3052 * the pid transfer logic in de_thread. 3053 * 3054 * So we perform the straight forward test of seeing 3055 * if the pid we have found is the pid of a thread 3056 * group leader, and don't worry if the task we have 3057 * found doesn't happen to be a thread group leader. 3058 * As we don't care in the case of readdir. 3059 */ 3060 if (!iter.task || !has_group_leader_pid(iter.task)) { 3061 iter.tgid += 1; 3062 goto retry; 3063 } 3064 get_task_struct(iter.task); 3065 } 3066 rcu_read_unlock(); 3067 return iter; 3068 } 3069 3070 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 3071 3072 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3073 struct tgid_iter iter) 3074 { 3075 char name[PROC_NUMBUF]; 3076 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 3077 return proc_fill_cache(filp, dirent, filldir, name, len, 3078 proc_pid_instantiate, iter.task, NULL); 3079 } 3080 3081 /* for the /proc/ directory itself, after non-process stuff has been done */ 3082 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 3083 { 3084 unsigned int nr; 3085 struct task_struct *reaper; 3086 struct tgid_iter iter; 3087 struct pid_namespace *ns; 3088 3089 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET) 3090 goto out_no_task; 3091 nr = filp->f_pos - FIRST_PROCESS_ENTRY; 3092 3093 reaper = get_proc_task(filp->f_path.dentry->d_inode); 3094 if (!reaper) 3095 goto out_no_task; 3096 3097 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 3098 const struct pid_entry *p = &proc_base_stuff[nr]; 3099 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 3100 goto out; 3101 } 3102 3103 ns = filp->f_dentry->d_sb->s_fs_info; 3104 iter.task = NULL; 3105 iter.tgid = filp->f_pos - TGID_OFFSET; 3106 for (iter = next_tgid(ns, iter); 3107 iter.task; 3108 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3109 filp->f_pos = iter.tgid + TGID_OFFSET; 3110 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) { 3111 put_task_struct(iter.task); 3112 goto out; 3113 } 3114 } 3115 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 3116 out: 3117 put_task_struct(reaper); 3118 out_no_task: 3119 return 0; 3120 } 3121 3122 /* 3123 * Tasks 3124 */ 3125 static const struct pid_entry tid_base_stuff[] = { 3126 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3127 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3128 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3129 REG("environ", S_IRUSR, proc_environ_operations), 3130 INF("auxv", S_IRUSR, proc_pid_auxv), 3131 ONE("status", S_IRUGO, proc_pid_status), 3132 ONE("personality", S_IRUGO, proc_pid_personality), 3133 INF("limits", S_IRUGO, proc_pid_limits), 3134 #ifdef CONFIG_SCHED_DEBUG 3135 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3136 #endif 3137 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3138 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3139 INF("syscall", S_IRUGO, proc_pid_syscall), 3140 #endif 3141 INF("cmdline", S_IRUGO, proc_pid_cmdline), 3142 ONE("stat", S_IRUGO, proc_tid_stat), 3143 ONE("statm", S_IRUGO, proc_pid_statm), 3144 REG("maps", S_IRUGO, proc_maps_operations), 3145 #ifdef CONFIG_NUMA 3146 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 3147 #endif 3148 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3149 LNK("cwd", proc_cwd_link), 3150 LNK("root", proc_root_link), 3151 LNK("exe", proc_exe_link), 3152 REG("mounts", S_IRUGO, proc_mounts_operations), 3153 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3154 #ifdef CONFIG_PROC_PAGE_MONITOR 3155 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3156 REG("smaps", S_IRUGO, proc_smaps_operations), 3157 REG("pagemap", S_IRUGO, proc_pagemap_operations), 3158 #endif 3159 #ifdef CONFIG_SECURITY 3160 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3161 #endif 3162 #ifdef CONFIG_KALLSYMS 3163 INF("wchan", S_IRUGO, proc_pid_wchan), 3164 #endif 3165 #ifdef CONFIG_STACKTRACE 3166 ONE("stack", S_IRUGO, proc_pid_stack), 3167 #endif 3168 #ifdef CONFIG_SCHEDSTATS 3169 INF("schedstat", S_IRUGO, proc_pid_schedstat), 3170 #endif 3171 #ifdef CONFIG_LATENCYTOP 3172 REG("latency", S_IRUGO, proc_lstats_operations), 3173 #endif 3174 #ifdef CONFIG_PROC_PID_CPUSET 3175 REG("cpuset", S_IRUGO, proc_cpuset_operations), 3176 #endif 3177 #ifdef CONFIG_CGROUPS 3178 REG("cgroup", S_IRUGO, proc_cgroup_operations), 3179 #endif 3180 INF("oom_score", S_IRUGO, proc_oom_score), 3181 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 3182 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3183 #ifdef CONFIG_AUDITSYSCALL 3184 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3185 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3186 #endif 3187 #ifdef CONFIG_FAULT_INJECTION 3188 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3189 #endif 3190 #ifdef CONFIG_TASK_IO_ACCOUNTING 3191 INF("io", S_IRUSR, proc_tid_io_accounting), 3192 #endif 3193 #ifdef CONFIG_HARDWALL 3194 INF("hardwall", S_IRUGO, proc_pid_hardwall), 3195 #endif 3196 }; 3197 3198 static int proc_tid_base_readdir(struct file * filp, 3199 void * dirent, filldir_t filldir) 3200 { 3201 return proc_pident_readdir(filp,dirent,filldir, 3202 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 3203 } 3204 3205 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 3206 return proc_pident_lookup(dir, dentry, 3207 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3208 } 3209 3210 static const struct file_operations proc_tid_base_operations = { 3211 .read = generic_read_dir, 3212 .readdir = proc_tid_base_readdir, 3213 .llseek = default_llseek, 3214 }; 3215 3216 static const struct inode_operations proc_tid_base_inode_operations = { 3217 .lookup = proc_tid_base_lookup, 3218 .getattr = pid_getattr, 3219 .setattr = proc_setattr, 3220 }; 3221 3222 static struct dentry *proc_task_instantiate(struct inode *dir, 3223 struct dentry *dentry, struct task_struct *task, const void *ptr) 3224 { 3225 struct dentry *error = ERR_PTR(-ENOENT); 3226 struct inode *inode; 3227 inode = proc_pid_make_inode(dir->i_sb, task); 3228 3229 if (!inode) 3230 goto out; 3231 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3232 inode->i_op = &proc_tid_base_inode_operations; 3233 inode->i_fop = &proc_tid_base_operations; 3234 inode->i_flags|=S_IMMUTABLE; 3235 3236 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff, 3237 ARRAY_SIZE(tid_base_stuff))); 3238 3239 d_set_d_op(dentry, &pid_dentry_operations); 3240 3241 d_add(dentry, inode); 3242 /* Close the race of the process dying before we return the dentry */ 3243 if (pid_revalidate(dentry, NULL)) 3244 error = NULL; 3245 out: 3246 return error; 3247 } 3248 3249 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 3250 { 3251 struct dentry *result = ERR_PTR(-ENOENT); 3252 struct task_struct *task; 3253 struct task_struct *leader = get_proc_task(dir); 3254 unsigned tid; 3255 struct pid_namespace *ns; 3256 3257 if (!leader) 3258 goto out_no_task; 3259 3260 tid = name_to_int(dentry); 3261 if (tid == ~0U) 3262 goto out; 3263 3264 ns = dentry->d_sb->s_fs_info; 3265 rcu_read_lock(); 3266 task = find_task_by_pid_ns(tid, ns); 3267 if (task) 3268 get_task_struct(task); 3269 rcu_read_unlock(); 3270 if (!task) 3271 goto out; 3272 if (!same_thread_group(leader, task)) 3273 goto out_drop_task; 3274 3275 result = proc_task_instantiate(dir, dentry, task, NULL); 3276 out_drop_task: 3277 put_task_struct(task); 3278 out: 3279 put_task_struct(leader); 3280 out_no_task: 3281 return result; 3282 } 3283 3284 /* 3285 * Find the first tid of a thread group to return to user space. 3286 * 3287 * Usually this is just the thread group leader, but if the users 3288 * buffer was too small or there was a seek into the middle of the 3289 * directory we have more work todo. 3290 * 3291 * In the case of a short read we start with find_task_by_pid. 3292 * 3293 * In the case of a seek we start with the leader and walk nr 3294 * threads past it. 3295 */ 3296 static struct task_struct *first_tid(struct task_struct *leader, 3297 int tid, int nr, struct pid_namespace *ns) 3298 { 3299 struct task_struct *pos; 3300 3301 rcu_read_lock(); 3302 /* Attempt to start with the pid of a thread */ 3303 if (tid && (nr > 0)) { 3304 pos = find_task_by_pid_ns(tid, ns); 3305 if (pos && (pos->group_leader == leader)) 3306 goto found; 3307 } 3308 3309 /* If nr exceeds the number of threads there is nothing todo */ 3310 pos = NULL; 3311 if (nr && nr >= get_nr_threads(leader)) 3312 goto out; 3313 3314 /* If we haven't found our starting place yet start 3315 * with the leader and walk nr threads forward. 3316 */ 3317 for (pos = leader; nr > 0; --nr) { 3318 pos = next_thread(pos); 3319 if (pos == leader) { 3320 pos = NULL; 3321 goto out; 3322 } 3323 } 3324 found: 3325 get_task_struct(pos); 3326 out: 3327 rcu_read_unlock(); 3328 return pos; 3329 } 3330 3331 /* 3332 * Find the next thread in the thread list. 3333 * Return NULL if there is an error or no next thread. 3334 * 3335 * The reference to the input task_struct is released. 3336 */ 3337 static struct task_struct *next_tid(struct task_struct *start) 3338 { 3339 struct task_struct *pos = NULL; 3340 rcu_read_lock(); 3341 if (pid_alive(start)) { 3342 pos = next_thread(start); 3343 if (thread_group_leader(pos)) 3344 pos = NULL; 3345 else 3346 get_task_struct(pos); 3347 } 3348 rcu_read_unlock(); 3349 put_task_struct(start); 3350 return pos; 3351 } 3352 3353 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3354 struct task_struct *task, int tid) 3355 { 3356 char name[PROC_NUMBUF]; 3357 int len = snprintf(name, sizeof(name), "%d", tid); 3358 return proc_fill_cache(filp, dirent, filldir, name, len, 3359 proc_task_instantiate, task, NULL); 3360 } 3361 3362 /* for the /proc/TGID/task/ directories */ 3363 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 3364 { 3365 struct dentry *dentry = filp->f_path.dentry; 3366 struct inode *inode = dentry->d_inode; 3367 struct task_struct *leader = NULL; 3368 struct task_struct *task; 3369 int retval = -ENOENT; 3370 ino_t ino; 3371 int tid; 3372 struct pid_namespace *ns; 3373 3374 task = get_proc_task(inode); 3375 if (!task) 3376 goto out_no_task; 3377 rcu_read_lock(); 3378 if (pid_alive(task)) { 3379 leader = task->group_leader; 3380 get_task_struct(leader); 3381 } 3382 rcu_read_unlock(); 3383 put_task_struct(task); 3384 if (!leader) 3385 goto out_no_task; 3386 retval = 0; 3387 3388 switch ((unsigned long)filp->f_pos) { 3389 case 0: 3390 ino = inode->i_ino; 3391 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0) 3392 goto out; 3393 filp->f_pos++; 3394 /* fall through */ 3395 case 1: 3396 ino = parent_ino(dentry); 3397 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0) 3398 goto out; 3399 filp->f_pos++; 3400 /* fall through */ 3401 } 3402 3403 /* f_version caches the tgid value that the last readdir call couldn't 3404 * return. lseek aka telldir automagically resets f_version to 0. 3405 */ 3406 ns = filp->f_dentry->d_sb->s_fs_info; 3407 tid = (int)filp->f_version; 3408 filp->f_version = 0; 3409 for (task = first_tid(leader, tid, filp->f_pos - 2, ns); 3410 task; 3411 task = next_tid(task), filp->f_pos++) { 3412 tid = task_pid_nr_ns(task, ns); 3413 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 3414 /* returning this tgid failed, save it as the first 3415 * pid for the next readir call */ 3416 filp->f_version = (u64)tid; 3417 put_task_struct(task); 3418 break; 3419 } 3420 } 3421 out: 3422 put_task_struct(leader); 3423 out_no_task: 3424 return retval; 3425 } 3426 3427 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3428 { 3429 struct inode *inode = dentry->d_inode; 3430 struct task_struct *p = get_proc_task(inode); 3431 generic_fillattr(inode, stat); 3432 3433 if (p) { 3434 stat->nlink += get_nr_threads(p); 3435 put_task_struct(p); 3436 } 3437 3438 return 0; 3439 } 3440 3441 static const struct inode_operations proc_task_inode_operations = { 3442 .lookup = proc_task_lookup, 3443 .getattr = proc_task_getattr, 3444 .setattr = proc_setattr, 3445 }; 3446 3447 static const struct file_operations proc_task_operations = { 3448 .read = generic_read_dir, 3449 .readdir = proc_task_readdir, 3450 .llseek = default_llseek, 3451 }; 3452