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