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