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