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, 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; 1003 1004 if (!task) 1005 return -ESRCH; 1006 oom_adjust = task->oomkilladj; 1007 put_task_struct(task); 1008 1009 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); 1010 1011 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1012 } 1013 1014 static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 1015 size_t count, loff_t *ppos) 1016 { 1017 struct task_struct *task; 1018 char buffer[PROC_NUMBUF], *end; 1019 int oom_adjust; 1020 1021 memset(buffer, 0, sizeof(buffer)); 1022 if (count > sizeof(buffer) - 1) 1023 count = sizeof(buffer) - 1; 1024 if (copy_from_user(buffer, buf, count)) 1025 return -EFAULT; 1026 oom_adjust = simple_strtol(buffer, &end, 0); 1027 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && 1028 oom_adjust != OOM_DISABLE) 1029 return -EINVAL; 1030 if (*end == '\n') 1031 end++; 1032 task = get_proc_task(file->f_path.dentry->d_inode); 1033 if (!task) 1034 return -ESRCH; 1035 if (oom_adjust < task->oomkilladj && !capable(CAP_SYS_RESOURCE)) { 1036 put_task_struct(task); 1037 return -EACCES; 1038 } 1039 task->oomkilladj = oom_adjust; 1040 put_task_struct(task); 1041 if (end - buffer == 0) 1042 return -EIO; 1043 return end - buffer; 1044 } 1045 1046 static const struct file_operations proc_oom_adjust_operations = { 1047 .read = oom_adjust_read, 1048 .write = oom_adjust_write, 1049 }; 1050 1051 #ifdef CONFIG_AUDITSYSCALL 1052 #define TMPBUFLEN 21 1053 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1054 size_t count, loff_t *ppos) 1055 { 1056 struct inode * inode = file->f_path.dentry->d_inode; 1057 struct task_struct *task = get_proc_task(inode); 1058 ssize_t length; 1059 char tmpbuf[TMPBUFLEN]; 1060 1061 if (!task) 1062 return -ESRCH; 1063 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1064 audit_get_loginuid(task)); 1065 put_task_struct(task); 1066 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1067 } 1068 1069 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1070 size_t count, loff_t *ppos) 1071 { 1072 struct inode * inode = file->f_path.dentry->d_inode; 1073 char *page, *tmp; 1074 ssize_t length; 1075 uid_t loginuid; 1076 1077 if (!capable(CAP_AUDIT_CONTROL)) 1078 return -EPERM; 1079 1080 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) 1081 return -EPERM; 1082 1083 if (count >= PAGE_SIZE) 1084 count = PAGE_SIZE - 1; 1085 1086 if (*ppos != 0) { 1087 /* No partial writes. */ 1088 return -EINVAL; 1089 } 1090 page = (char*)__get_free_page(GFP_TEMPORARY); 1091 if (!page) 1092 return -ENOMEM; 1093 length = -EFAULT; 1094 if (copy_from_user(page, buf, count)) 1095 goto out_free_page; 1096 1097 page[count] = '\0'; 1098 loginuid = simple_strtoul(page, &tmp, 10); 1099 if (tmp == page) { 1100 length = -EINVAL; 1101 goto out_free_page; 1102 1103 } 1104 length = audit_set_loginuid(current, loginuid); 1105 if (likely(length == 0)) 1106 length = count; 1107 1108 out_free_page: 1109 free_page((unsigned long) page); 1110 return length; 1111 } 1112 1113 static const struct file_operations proc_loginuid_operations = { 1114 .read = proc_loginuid_read, 1115 .write = proc_loginuid_write, 1116 }; 1117 1118 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1119 size_t count, loff_t *ppos) 1120 { 1121 struct inode * inode = file->f_path.dentry->d_inode; 1122 struct task_struct *task = get_proc_task(inode); 1123 ssize_t length; 1124 char tmpbuf[TMPBUFLEN]; 1125 1126 if (!task) 1127 return -ESRCH; 1128 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1129 audit_get_sessionid(task)); 1130 put_task_struct(task); 1131 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1132 } 1133 1134 static const struct file_operations proc_sessionid_operations = { 1135 .read = proc_sessionid_read, 1136 }; 1137 #endif 1138 1139 #ifdef CONFIG_FAULT_INJECTION 1140 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1141 size_t count, loff_t *ppos) 1142 { 1143 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1144 char buffer[PROC_NUMBUF]; 1145 size_t len; 1146 int make_it_fail; 1147 1148 if (!task) 1149 return -ESRCH; 1150 make_it_fail = task->make_it_fail; 1151 put_task_struct(task); 1152 1153 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1154 1155 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1156 } 1157 1158 static ssize_t proc_fault_inject_write(struct file * file, 1159 const char __user * buf, size_t count, loff_t *ppos) 1160 { 1161 struct task_struct *task; 1162 char buffer[PROC_NUMBUF], *end; 1163 int make_it_fail; 1164 1165 if (!capable(CAP_SYS_RESOURCE)) 1166 return -EPERM; 1167 memset(buffer, 0, sizeof(buffer)); 1168 if (count > sizeof(buffer) - 1) 1169 count = sizeof(buffer) - 1; 1170 if (copy_from_user(buffer, buf, count)) 1171 return -EFAULT; 1172 make_it_fail = simple_strtol(buffer, &end, 0); 1173 if (*end == '\n') 1174 end++; 1175 task = get_proc_task(file->f_dentry->d_inode); 1176 if (!task) 1177 return -ESRCH; 1178 task->make_it_fail = make_it_fail; 1179 put_task_struct(task); 1180 if (end - buffer == 0) 1181 return -EIO; 1182 return end - buffer; 1183 } 1184 1185 static const struct file_operations proc_fault_inject_operations = { 1186 .read = proc_fault_inject_read, 1187 .write = proc_fault_inject_write, 1188 }; 1189 #endif 1190 1191 1192 #ifdef CONFIG_SCHED_DEBUG 1193 /* 1194 * Print out various scheduling related per-task fields: 1195 */ 1196 static int sched_show(struct seq_file *m, void *v) 1197 { 1198 struct inode *inode = m->private; 1199 struct task_struct *p; 1200 1201 p = get_proc_task(inode); 1202 if (!p) 1203 return -ESRCH; 1204 proc_sched_show_task(p, m); 1205 1206 put_task_struct(p); 1207 1208 return 0; 1209 } 1210 1211 static ssize_t 1212 sched_write(struct file *file, const char __user *buf, 1213 size_t count, loff_t *offset) 1214 { 1215 struct inode *inode = file->f_path.dentry->d_inode; 1216 struct task_struct *p; 1217 1218 p = get_proc_task(inode); 1219 if (!p) 1220 return -ESRCH; 1221 proc_sched_set_task(p); 1222 1223 put_task_struct(p); 1224 1225 return count; 1226 } 1227 1228 static int sched_open(struct inode *inode, struct file *filp) 1229 { 1230 int ret; 1231 1232 ret = single_open(filp, sched_show, NULL); 1233 if (!ret) { 1234 struct seq_file *m = filp->private_data; 1235 1236 m->private = inode; 1237 } 1238 return ret; 1239 } 1240 1241 static const struct file_operations proc_pid_sched_operations = { 1242 .open = sched_open, 1243 .read = seq_read, 1244 .write = sched_write, 1245 .llseek = seq_lseek, 1246 .release = single_release, 1247 }; 1248 1249 #endif 1250 1251 /* 1252 * We added or removed a vma mapping the executable. The vmas are only mapped 1253 * during exec and are not mapped with the mmap system call. 1254 * Callers must hold down_write() on the mm's mmap_sem for these 1255 */ 1256 void added_exe_file_vma(struct mm_struct *mm) 1257 { 1258 mm->num_exe_file_vmas++; 1259 } 1260 1261 void removed_exe_file_vma(struct mm_struct *mm) 1262 { 1263 mm->num_exe_file_vmas--; 1264 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){ 1265 fput(mm->exe_file); 1266 mm->exe_file = NULL; 1267 } 1268 1269 } 1270 1271 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) 1272 { 1273 if (new_exe_file) 1274 get_file(new_exe_file); 1275 if (mm->exe_file) 1276 fput(mm->exe_file); 1277 mm->exe_file = new_exe_file; 1278 mm->num_exe_file_vmas = 0; 1279 } 1280 1281 struct file *get_mm_exe_file(struct mm_struct *mm) 1282 { 1283 struct file *exe_file; 1284 1285 /* We need mmap_sem to protect against races with removal of 1286 * VM_EXECUTABLE vmas */ 1287 down_read(&mm->mmap_sem); 1288 exe_file = mm->exe_file; 1289 if (exe_file) 1290 get_file(exe_file); 1291 up_read(&mm->mmap_sem); 1292 return exe_file; 1293 } 1294 1295 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm) 1296 { 1297 /* It's safe to write the exe_file pointer without exe_file_lock because 1298 * this is called during fork when the task is not yet in /proc */ 1299 newmm->exe_file = get_mm_exe_file(oldmm); 1300 } 1301 1302 static int proc_exe_link(struct inode *inode, struct path *exe_path) 1303 { 1304 struct task_struct *task; 1305 struct mm_struct *mm; 1306 struct file *exe_file; 1307 1308 task = get_proc_task(inode); 1309 if (!task) 1310 return -ENOENT; 1311 mm = get_task_mm(task); 1312 put_task_struct(task); 1313 if (!mm) 1314 return -ENOENT; 1315 exe_file = get_mm_exe_file(mm); 1316 mmput(mm); 1317 if (exe_file) { 1318 *exe_path = exe_file->f_path; 1319 path_get(&exe_file->f_path); 1320 fput(exe_file); 1321 return 0; 1322 } else 1323 return -ENOENT; 1324 } 1325 1326 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1327 { 1328 struct inode *inode = dentry->d_inode; 1329 int error = -EACCES; 1330 1331 /* We don't need a base pointer in the /proc filesystem */ 1332 path_put(&nd->path); 1333 1334 /* Are we allowed to snoop on the tasks file descriptors? */ 1335 if (!proc_fd_access_allowed(inode)) 1336 goto out; 1337 1338 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path); 1339 nd->last_type = LAST_BIND; 1340 out: 1341 return ERR_PTR(error); 1342 } 1343 1344 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1345 { 1346 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1347 char *pathname; 1348 int len; 1349 1350 if (!tmp) 1351 return -ENOMEM; 1352 1353 pathname = d_path(path, tmp, PAGE_SIZE); 1354 len = PTR_ERR(pathname); 1355 if (IS_ERR(pathname)) 1356 goto out; 1357 len = tmp + PAGE_SIZE - 1 - pathname; 1358 1359 if (len > buflen) 1360 len = buflen; 1361 if (copy_to_user(buffer, pathname, len)) 1362 len = -EFAULT; 1363 out: 1364 free_page((unsigned long)tmp); 1365 return len; 1366 } 1367 1368 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1369 { 1370 int error = -EACCES; 1371 struct inode *inode = dentry->d_inode; 1372 struct path path; 1373 1374 /* Are we allowed to snoop on the tasks file descriptors? */ 1375 if (!proc_fd_access_allowed(inode)) 1376 goto out; 1377 1378 error = PROC_I(inode)->op.proc_get_link(inode, &path); 1379 if (error) 1380 goto out; 1381 1382 error = do_proc_readlink(&path, buffer, buflen); 1383 path_put(&path); 1384 out: 1385 return error; 1386 } 1387 1388 static const struct inode_operations proc_pid_link_inode_operations = { 1389 .readlink = proc_pid_readlink, 1390 .follow_link = proc_pid_follow_link, 1391 .setattr = proc_setattr, 1392 }; 1393 1394 1395 /* building an inode */ 1396 1397 static int task_dumpable(struct task_struct *task) 1398 { 1399 int dumpable = 0; 1400 struct mm_struct *mm; 1401 1402 task_lock(task); 1403 mm = task->mm; 1404 if (mm) 1405 dumpable = get_dumpable(mm); 1406 task_unlock(task); 1407 if(dumpable == 1) 1408 return 1; 1409 return 0; 1410 } 1411 1412 1413 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1414 { 1415 struct inode * inode; 1416 struct proc_inode *ei; 1417 const struct cred *cred; 1418 1419 /* We need a new inode */ 1420 1421 inode = new_inode(sb); 1422 if (!inode) 1423 goto out; 1424 1425 /* Common stuff */ 1426 ei = PROC_I(inode); 1427 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1428 inode->i_op = &proc_def_inode_operations; 1429 1430 /* 1431 * grab the reference to task. 1432 */ 1433 ei->pid = get_task_pid(task, PIDTYPE_PID); 1434 if (!ei->pid) 1435 goto out_unlock; 1436 1437 if (task_dumpable(task)) { 1438 rcu_read_lock(); 1439 cred = __task_cred(task); 1440 inode->i_uid = cred->euid; 1441 inode->i_gid = cred->egid; 1442 rcu_read_unlock(); 1443 } 1444 security_task_to_inode(task, inode); 1445 1446 out: 1447 return inode; 1448 1449 out_unlock: 1450 iput(inode); 1451 return NULL; 1452 } 1453 1454 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1455 { 1456 struct inode *inode = dentry->d_inode; 1457 struct task_struct *task; 1458 const struct cred *cred; 1459 1460 generic_fillattr(inode, stat); 1461 1462 rcu_read_lock(); 1463 stat->uid = 0; 1464 stat->gid = 0; 1465 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1466 if (task) { 1467 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1468 task_dumpable(task)) { 1469 cred = __task_cred(task); 1470 stat->uid = cred->euid; 1471 stat->gid = cred->egid; 1472 } 1473 } 1474 rcu_read_unlock(); 1475 return 0; 1476 } 1477 1478 /* dentry stuff */ 1479 1480 /* 1481 * Exceptional case: normally we are not allowed to unhash a busy 1482 * directory. In this case, however, we can do it - no aliasing problems 1483 * due to the way we treat inodes. 1484 * 1485 * Rewrite the inode's ownerships here because the owning task may have 1486 * performed a setuid(), etc. 1487 * 1488 * Before the /proc/pid/status file was created the only way to read 1489 * the effective uid of a /process was to stat /proc/pid. Reading 1490 * /proc/pid/status is slow enough that procps and other packages 1491 * kept stating /proc/pid. To keep the rules in /proc simple I have 1492 * made this apply to all per process world readable and executable 1493 * directories. 1494 */ 1495 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1496 { 1497 struct inode *inode = dentry->d_inode; 1498 struct task_struct *task = get_proc_task(inode); 1499 const struct cred *cred; 1500 1501 if (task) { 1502 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1503 task_dumpable(task)) { 1504 rcu_read_lock(); 1505 cred = __task_cred(task); 1506 inode->i_uid = cred->euid; 1507 inode->i_gid = cred->egid; 1508 rcu_read_unlock(); 1509 } else { 1510 inode->i_uid = 0; 1511 inode->i_gid = 0; 1512 } 1513 inode->i_mode &= ~(S_ISUID | S_ISGID); 1514 security_task_to_inode(task, inode); 1515 put_task_struct(task); 1516 return 1; 1517 } 1518 d_drop(dentry); 1519 return 0; 1520 } 1521 1522 static int pid_delete_dentry(struct dentry * dentry) 1523 { 1524 /* Is the task we represent dead? 1525 * If so, then don't put the dentry on the lru list, 1526 * kill it immediately. 1527 */ 1528 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1529 } 1530 1531 static const struct dentry_operations pid_dentry_operations = 1532 { 1533 .d_revalidate = pid_revalidate, 1534 .d_delete = pid_delete_dentry, 1535 }; 1536 1537 /* Lookups */ 1538 1539 typedef struct dentry *instantiate_t(struct inode *, struct dentry *, 1540 struct task_struct *, const void *); 1541 1542 /* 1543 * Fill a directory entry. 1544 * 1545 * If possible create the dcache entry and derive our inode number and 1546 * file type from dcache entry. 1547 * 1548 * Since all of the proc inode numbers are dynamically generated, the inode 1549 * numbers do not exist until the inode is cache. This means creating the 1550 * the dcache entry in readdir is necessary to keep the inode numbers 1551 * reported by readdir in sync with the inode numbers reported 1552 * by stat. 1553 */ 1554 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1555 char *name, int len, 1556 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1557 { 1558 struct dentry *child, *dir = filp->f_path.dentry; 1559 struct inode *inode; 1560 struct qstr qname; 1561 ino_t ino = 0; 1562 unsigned type = DT_UNKNOWN; 1563 1564 qname.name = name; 1565 qname.len = len; 1566 qname.hash = full_name_hash(name, len); 1567 1568 child = d_lookup(dir, &qname); 1569 if (!child) { 1570 struct dentry *new; 1571 new = d_alloc(dir, &qname); 1572 if (new) { 1573 child = instantiate(dir->d_inode, new, task, ptr); 1574 if (child) 1575 dput(new); 1576 else 1577 child = new; 1578 } 1579 } 1580 if (!child || IS_ERR(child) || !child->d_inode) 1581 goto end_instantiate; 1582 inode = child->d_inode; 1583 if (inode) { 1584 ino = inode->i_ino; 1585 type = inode->i_mode >> 12; 1586 } 1587 dput(child); 1588 end_instantiate: 1589 if (!ino) 1590 ino = find_inode_number(dir, &qname); 1591 if (!ino) 1592 ino = 1; 1593 return filldir(dirent, name, len, filp->f_pos, ino, type); 1594 } 1595 1596 static unsigned name_to_int(struct dentry *dentry) 1597 { 1598 const char *name = dentry->d_name.name; 1599 int len = dentry->d_name.len; 1600 unsigned n = 0; 1601 1602 if (len > 1 && *name == '0') 1603 goto out; 1604 while (len-- > 0) { 1605 unsigned c = *name++ - '0'; 1606 if (c > 9) 1607 goto out; 1608 if (n >= (~0U-9)/10) 1609 goto out; 1610 n *= 10; 1611 n += c; 1612 } 1613 return n; 1614 out: 1615 return ~0U; 1616 } 1617 1618 #define PROC_FDINFO_MAX 64 1619 1620 static int proc_fd_info(struct inode *inode, struct path *path, char *info) 1621 { 1622 struct task_struct *task = get_proc_task(inode); 1623 struct files_struct *files = NULL; 1624 struct file *file; 1625 int fd = proc_fd(inode); 1626 1627 if (task) { 1628 files = get_files_struct(task); 1629 put_task_struct(task); 1630 } 1631 if (files) { 1632 /* 1633 * We are not taking a ref to the file structure, so we must 1634 * hold ->file_lock. 1635 */ 1636 spin_lock(&files->file_lock); 1637 file = fcheck_files(files, fd); 1638 if (file) { 1639 if (path) { 1640 *path = file->f_path; 1641 path_get(&file->f_path); 1642 } 1643 if (info) 1644 snprintf(info, PROC_FDINFO_MAX, 1645 "pos:\t%lli\n" 1646 "flags:\t0%o\n", 1647 (long long) file->f_pos, 1648 file->f_flags); 1649 spin_unlock(&files->file_lock); 1650 put_files_struct(files); 1651 return 0; 1652 } 1653 spin_unlock(&files->file_lock); 1654 put_files_struct(files); 1655 } 1656 return -ENOENT; 1657 } 1658 1659 static int proc_fd_link(struct inode *inode, struct path *path) 1660 { 1661 return proc_fd_info(inode, path, NULL); 1662 } 1663 1664 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1665 { 1666 struct inode *inode = dentry->d_inode; 1667 struct task_struct *task = get_proc_task(inode); 1668 int fd = proc_fd(inode); 1669 struct files_struct *files; 1670 const struct cred *cred; 1671 1672 if (task) { 1673 files = get_files_struct(task); 1674 if (files) { 1675 rcu_read_lock(); 1676 if (fcheck_files(files, fd)) { 1677 rcu_read_unlock(); 1678 put_files_struct(files); 1679 if (task_dumpable(task)) { 1680 rcu_read_lock(); 1681 cred = __task_cred(task); 1682 inode->i_uid = cred->euid; 1683 inode->i_gid = cred->egid; 1684 rcu_read_unlock(); 1685 } else { 1686 inode->i_uid = 0; 1687 inode->i_gid = 0; 1688 } 1689 inode->i_mode &= ~(S_ISUID | S_ISGID); 1690 security_task_to_inode(task, inode); 1691 put_task_struct(task); 1692 return 1; 1693 } 1694 rcu_read_unlock(); 1695 put_files_struct(files); 1696 } 1697 put_task_struct(task); 1698 } 1699 d_drop(dentry); 1700 return 0; 1701 } 1702 1703 static const struct dentry_operations tid_fd_dentry_operations = 1704 { 1705 .d_revalidate = tid_fd_revalidate, 1706 .d_delete = pid_delete_dentry, 1707 }; 1708 1709 static struct dentry *proc_fd_instantiate(struct inode *dir, 1710 struct dentry *dentry, struct task_struct *task, const void *ptr) 1711 { 1712 unsigned fd = *(const unsigned *)ptr; 1713 struct file *file; 1714 struct files_struct *files; 1715 struct inode *inode; 1716 struct proc_inode *ei; 1717 struct dentry *error = ERR_PTR(-ENOENT); 1718 1719 inode = proc_pid_make_inode(dir->i_sb, task); 1720 if (!inode) 1721 goto out; 1722 ei = PROC_I(inode); 1723 ei->fd = fd; 1724 files = get_files_struct(task); 1725 if (!files) 1726 goto out_iput; 1727 inode->i_mode = S_IFLNK; 1728 1729 /* 1730 * We are not taking a ref to the file structure, so we must 1731 * hold ->file_lock. 1732 */ 1733 spin_lock(&files->file_lock); 1734 file = fcheck_files(files, fd); 1735 if (!file) 1736 goto out_unlock; 1737 if (file->f_mode & FMODE_READ) 1738 inode->i_mode |= S_IRUSR | S_IXUSR; 1739 if (file->f_mode & FMODE_WRITE) 1740 inode->i_mode |= S_IWUSR | S_IXUSR; 1741 spin_unlock(&files->file_lock); 1742 put_files_struct(files); 1743 1744 inode->i_op = &proc_pid_link_inode_operations; 1745 inode->i_size = 64; 1746 ei->op.proc_get_link = proc_fd_link; 1747 dentry->d_op = &tid_fd_dentry_operations; 1748 d_add(dentry, inode); 1749 /* Close the race of the process dying before we return the dentry */ 1750 if (tid_fd_revalidate(dentry, NULL)) 1751 error = NULL; 1752 1753 out: 1754 return error; 1755 out_unlock: 1756 spin_unlock(&files->file_lock); 1757 put_files_struct(files); 1758 out_iput: 1759 iput(inode); 1760 goto out; 1761 } 1762 1763 static struct dentry *proc_lookupfd_common(struct inode *dir, 1764 struct dentry *dentry, 1765 instantiate_t instantiate) 1766 { 1767 struct task_struct *task = get_proc_task(dir); 1768 unsigned fd = name_to_int(dentry); 1769 struct dentry *result = ERR_PTR(-ENOENT); 1770 1771 if (!task) 1772 goto out_no_task; 1773 if (fd == ~0U) 1774 goto out; 1775 1776 result = instantiate(dir, dentry, task, &fd); 1777 out: 1778 put_task_struct(task); 1779 out_no_task: 1780 return result; 1781 } 1782 1783 static int proc_readfd_common(struct file * filp, void * dirent, 1784 filldir_t filldir, instantiate_t instantiate) 1785 { 1786 struct dentry *dentry = filp->f_path.dentry; 1787 struct inode *inode = dentry->d_inode; 1788 struct task_struct *p = get_proc_task(inode); 1789 unsigned int fd, ino; 1790 int retval; 1791 struct files_struct * files; 1792 1793 retval = -ENOENT; 1794 if (!p) 1795 goto out_no_task; 1796 retval = 0; 1797 1798 fd = filp->f_pos; 1799 switch (fd) { 1800 case 0: 1801 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 1802 goto out; 1803 filp->f_pos++; 1804 case 1: 1805 ino = parent_ino(dentry); 1806 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 1807 goto out; 1808 filp->f_pos++; 1809 default: 1810 files = get_files_struct(p); 1811 if (!files) 1812 goto out; 1813 rcu_read_lock(); 1814 for (fd = filp->f_pos-2; 1815 fd < files_fdtable(files)->max_fds; 1816 fd++, filp->f_pos++) { 1817 char name[PROC_NUMBUF]; 1818 int len; 1819 1820 if (!fcheck_files(files, fd)) 1821 continue; 1822 rcu_read_unlock(); 1823 1824 len = snprintf(name, sizeof(name), "%d", fd); 1825 if (proc_fill_cache(filp, dirent, filldir, 1826 name, len, instantiate, 1827 p, &fd) < 0) { 1828 rcu_read_lock(); 1829 break; 1830 } 1831 rcu_read_lock(); 1832 } 1833 rcu_read_unlock(); 1834 put_files_struct(files); 1835 } 1836 out: 1837 put_task_struct(p); 1838 out_no_task: 1839 return retval; 1840 } 1841 1842 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 1843 struct nameidata *nd) 1844 { 1845 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 1846 } 1847 1848 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 1849 { 1850 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 1851 } 1852 1853 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 1854 size_t len, loff_t *ppos) 1855 { 1856 char tmp[PROC_FDINFO_MAX]; 1857 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); 1858 if (!err) 1859 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 1860 return err; 1861 } 1862 1863 static const struct file_operations proc_fdinfo_file_operations = { 1864 .open = nonseekable_open, 1865 .read = proc_fdinfo_read, 1866 }; 1867 1868 static const struct file_operations proc_fd_operations = { 1869 .read = generic_read_dir, 1870 .readdir = proc_readfd, 1871 }; 1872 1873 /* 1874 * /proc/pid/fd needs a special permission handler so that a process can still 1875 * access /proc/self/fd after it has executed a setuid(). 1876 */ 1877 static int proc_fd_permission(struct inode *inode, int mask) 1878 { 1879 int rv; 1880 1881 rv = generic_permission(inode, mask, NULL); 1882 if (rv == 0) 1883 return 0; 1884 if (task_pid(current) == proc_pid(inode)) 1885 rv = 0; 1886 return rv; 1887 } 1888 1889 /* 1890 * proc directories can do almost nothing.. 1891 */ 1892 static const struct inode_operations proc_fd_inode_operations = { 1893 .lookup = proc_lookupfd, 1894 .permission = proc_fd_permission, 1895 .setattr = proc_setattr, 1896 }; 1897 1898 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 1899 struct dentry *dentry, struct task_struct *task, const void *ptr) 1900 { 1901 unsigned fd = *(unsigned *)ptr; 1902 struct inode *inode; 1903 struct proc_inode *ei; 1904 struct dentry *error = ERR_PTR(-ENOENT); 1905 1906 inode = proc_pid_make_inode(dir->i_sb, task); 1907 if (!inode) 1908 goto out; 1909 ei = PROC_I(inode); 1910 ei->fd = fd; 1911 inode->i_mode = S_IFREG | S_IRUSR; 1912 inode->i_fop = &proc_fdinfo_file_operations; 1913 dentry->d_op = &tid_fd_dentry_operations; 1914 d_add(dentry, inode); 1915 /* Close the race of the process dying before we return the dentry */ 1916 if (tid_fd_revalidate(dentry, NULL)) 1917 error = NULL; 1918 1919 out: 1920 return error; 1921 } 1922 1923 static struct dentry *proc_lookupfdinfo(struct inode *dir, 1924 struct dentry *dentry, 1925 struct nameidata *nd) 1926 { 1927 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 1928 } 1929 1930 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 1931 { 1932 return proc_readfd_common(filp, dirent, filldir, 1933 proc_fdinfo_instantiate); 1934 } 1935 1936 static const struct file_operations proc_fdinfo_operations = { 1937 .read = generic_read_dir, 1938 .readdir = proc_readfdinfo, 1939 }; 1940 1941 /* 1942 * proc directories can do almost nothing.. 1943 */ 1944 static const struct inode_operations proc_fdinfo_inode_operations = { 1945 .lookup = proc_lookupfdinfo, 1946 .setattr = proc_setattr, 1947 }; 1948 1949 1950 static struct dentry *proc_pident_instantiate(struct inode *dir, 1951 struct dentry *dentry, struct task_struct *task, const void *ptr) 1952 { 1953 const struct pid_entry *p = ptr; 1954 struct inode *inode; 1955 struct proc_inode *ei; 1956 struct dentry *error = ERR_PTR(-ENOENT); 1957 1958 inode = proc_pid_make_inode(dir->i_sb, task); 1959 if (!inode) 1960 goto out; 1961 1962 ei = PROC_I(inode); 1963 inode->i_mode = p->mode; 1964 if (S_ISDIR(inode->i_mode)) 1965 inode->i_nlink = 2; /* Use getattr to fix if necessary */ 1966 if (p->iop) 1967 inode->i_op = p->iop; 1968 if (p->fop) 1969 inode->i_fop = p->fop; 1970 ei->op = p->op; 1971 dentry->d_op = &pid_dentry_operations; 1972 d_add(dentry, inode); 1973 /* Close the race of the process dying before we return the dentry */ 1974 if (pid_revalidate(dentry, NULL)) 1975 error = NULL; 1976 out: 1977 return error; 1978 } 1979 1980 static struct dentry *proc_pident_lookup(struct inode *dir, 1981 struct dentry *dentry, 1982 const struct pid_entry *ents, 1983 unsigned int nents) 1984 { 1985 struct dentry *error; 1986 struct task_struct *task = get_proc_task(dir); 1987 const struct pid_entry *p, *last; 1988 1989 error = ERR_PTR(-ENOENT); 1990 1991 if (!task) 1992 goto out_no_task; 1993 1994 /* 1995 * Yes, it does not scale. And it should not. Don't add 1996 * new entries into /proc/<tgid>/ without very good reasons. 1997 */ 1998 last = &ents[nents - 1]; 1999 for (p = ents; p <= last; p++) { 2000 if (p->len != dentry->d_name.len) 2001 continue; 2002 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2003 break; 2004 } 2005 if (p > last) 2006 goto out; 2007 2008 error = proc_pident_instantiate(dir, dentry, task, p); 2009 out: 2010 put_task_struct(task); 2011 out_no_task: 2012 return error; 2013 } 2014 2015 static int proc_pident_fill_cache(struct file *filp, void *dirent, 2016 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2017 { 2018 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2019 proc_pident_instantiate, task, p); 2020 } 2021 2022 static int proc_pident_readdir(struct file *filp, 2023 void *dirent, filldir_t filldir, 2024 const struct pid_entry *ents, unsigned int nents) 2025 { 2026 int i; 2027 struct dentry *dentry = filp->f_path.dentry; 2028 struct inode *inode = dentry->d_inode; 2029 struct task_struct *task = get_proc_task(inode); 2030 const struct pid_entry *p, *last; 2031 ino_t ino; 2032 int ret; 2033 2034 ret = -ENOENT; 2035 if (!task) 2036 goto out_no_task; 2037 2038 ret = 0; 2039 i = filp->f_pos; 2040 switch (i) { 2041 case 0: 2042 ino = inode->i_ino; 2043 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 2044 goto out; 2045 i++; 2046 filp->f_pos++; 2047 /* fall through */ 2048 case 1: 2049 ino = parent_ino(dentry); 2050 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 2051 goto out; 2052 i++; 2053 filp->f_pos++; 2054 /* fall through */ 2055 default: 2056 i -= 2; 2057 if (i >= nents) { 2058 ret = 1; 2059 goto out; 2060 } 2061 p = ents + i; 2062 last = &ents[nents - 1]; 2063 while (p <= last) { 2064 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2065 goto out; 2066 filp->f_pos++; 2067 p++; 2068 } 2069 } 2070 2071 ret = 1; 2072 out: 2073 put_task_struct(task); 2074 out_no_task: 2075 return ret; 2076 } 2077 2078 #ifdef CONFIG_SECURITY 2079 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2080 size_t count, loff_t *ppos) 2081 { 2082 struct inode * inode = file->f_path.dentry->d_inode; 2083 char *p = NULL; 2084 ssize_t length; 2085 struct task_struct *task = get_proc_task(inode); 2086 2087 if (!task) 2088 return -ESRCH; 2089 2090 length = security_getprocattr(task, 2091 (char*)file->f_path.dentry->d_name.name, 2092 &p); 2093 put_task_struct(task); 2094 if (length > 0) 2095 length = simple_read_from_buffer(buf, count, ppos, p, length); 2096 kfree(p); 2097 return length; 2098 } 2099 2100 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2101 size_t count, loff_t *ppos) 2102 { 2103 struct inode * inode = file->f_path.dentry->d_inode; 2104 char *page; 2105 ssize_t length; 2106 struct task_struct *task = get_proc_task(inode); 2107 2108 length = -ESRCH; 2109 if (!task) 2110 goto out_no_task; 2111 if (count > PAGE_SIZE) 2112 count = PAGE_SIZE; 2113 2114 /* No partial writes. */ 2115 length = -EINVAL; 2116 if (*ppos != 0) 2117 goto out; 2118 2119 length = -ENOMEM; 2120 page = (char*)__get_free_page(GFP_TEMPORARY); 2121 if (!page) 2122 goto out; 2123 2124 length = -EFAULT; 2125 if (copy_from_user(page, buf, count)) 2126 goto out_free; 2127 2128 /* Guard against adverse ptrace interaction */ 2129 length = mutex_lock_interruptible(&task->cred_guard_mutex); 2130 if (length < 0) 2131 goto out_free; 2132 2133 length = security_setprocattr(task, 2134 (char*)file->f_path.dentry->d_name.name, 2135 (void*)page, count); 2136 mutex_unlock(&task->cred_guard_mutex); 2137 out_free: 2138 free_page((unsigned long) page); 2139 out: 2140 put_task_struct(task); 2141 out_no_task: 2142 return length; 2143 } 2144 2145 static const struct file_operations proc_pid_attr_operations = { 2146 .read = proc_pid_attr_read, 2147 .write = proc_pid_attr_write, 2148 }; 2149 2150 static const struct pid_entry attr_dir_stuff[] = { 2151 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2152 REG("prev", S_IRUGO, proc_pid_attr_operations), 2153 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2154 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2155 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2156 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2157 }; 2158 2159 static int proc_attr_dir_readdir(struct file * filp, 2160 void * dirent, filldir_t filldir) 2161 { 2162 return proc_pident_readdir(filp,dirent,filldir, 2163 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2164 } 2165 2166 static const struct file_operations proc_attr_dir_operations = { 2167 .read = generic_read_dir, 2168 .readdir = proc_attr_dir_readdir, 2169 }; 2170 2171 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2172 struct dentry *dentry, struct nameidata *nd) 2173 { 2174 return proc_pident_lookup(dir, dentry, 2175 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2176 } 2177 2178 static const struct inode_operations proc_attr_dir_inode_operations = { 2179 .lookup = proc_attr_dir_lookup, 2180 .getattr = pid_getattr, 2181 .setattr = proc_setattr, 2182 }; 2183 2184 #endif 2185 2186 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2187 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2188 size_t count, loff_t *ppos) 2189 { 2190 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2191 struct mm_struct *mm; 2192 char buffer[PROC_NUMBUF]; 2193 size_t len; 2194 int ret; 2195 2196 if (!task) 2197 return -ESRCH; 2198 2199 ret = 0; 2200 mm = get_task_mm(task); 2201 if (mm) { 2202 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2203 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2204 MMF_DUMP_FILTER_SHIFT)); 2205 mmput(mm); 2206 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2207 } 2208 2209 put_task_struct(task); 2210 2211 return ret; 2212 } 2213 2214 static ssize_t proc_coredump_filter_write(struct file *file, 2215 const char __user *buf, 2216 size_t count, 2217 loff_t *ppos) 2218 { 2219 struct task_struct *task; 2220 struct mm_struct *mm; 2221 char buffer[PROC_NUMBUF], *end; 2222 unsigned int val; 2223 int ret; 2224 int i; 2225 unsigned long mask; 2226 2227 ret = -EFAULT; 2228 memset(buffer, 0, sizeof(buffer)); 2229 if (count > sizeof(buffer) - 1) 2230 count = sizeof(buffer) - 1; 2231 if (copy_from_user(buffer, buf, count)) 2232 goto out_no_task; 2233 2234 ret = -EINVAL; 2235 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2236 if (*end == '\n') 2237 end++; 2238 if (end - buffer == 0) 2239 goto out_no_task; 2240 2241 ret = -ESRCH; 2242 task = get_proc_task(file->f_dentry->d_inode); 2243 if (!task) 2244 goto out_no_task; 2245 2246 ret = end - buffer; 2247 mm = get_task_mm(task); 2248 if (!mm) 2249 goto out_no_mm; 2250 2251 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2252 if (val & mask) 2253 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2254 else 2255 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2256 } 2257 2258 mmput(mm); 2259 out_no_mm: 2260 put_task_struct(task); 2261 out_no_task: 2262 return ret; 2263 } 2264 2265 static const struct file_operations proc_coredump_filter_operations = { 2266 .read = proc_coredump_filter_read, 2267 .write = proc_coredump_filter_write, 2268 }; 2269 #endif 2270 2271 /* 2272 * /proc/self: 2273 */ 2274 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2275 int buflen) 2276 { 2277 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2278 pid_t tgid = task_tgid_nr_ns(current, ns); 2279 char tmp[PROC_NUMBUF]; 2280 if (!tgid) 2281 return -ENOENT; 2282 sprintf(tmp, "%d", tgid); 2283 return vfs_readlink(dentry,buffer,buflen,tmp); 2284 } 2285 2286 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2287 { 2288 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2289 pid_t tgid = task_tgid_nr_ns(current, ns); 2290 char tmp[PROC_NUMBUF]; 2291 if (!tgid) 2292 return ERR_PTR(-ENOENT); 2293 sprintf(tmp, "%d", task_tgid_nr_ns(current, ns)); 2294 return ERR_PTR(vfs_follow_link(nd,tmp)); 2295 } 2296 2297 static const struct inode_operations proc_self_inode_operations = { 2298 .readlink = proc_self_readlink, 2299 .follow_link = proc_self_follow_link, 2300 }; 2301 2302 /* 2303 * proc base 2304 * 2305 * These are the directory entries in the root directory of /proc 2306 * that properly belong to the /proc filesystem, as they describe 2307 * describe something that is process related. 2308 */ 2309 static const struct pid_entry proc_base_stuff[] = { 2310 NOD("self", S_IFLNK|S_IRWXUGO, 2311 &proc_self_inode_operations, NULL, {}), 2312 }; 2313 2314 /* 2315 * Exceptional case: normally we are not allowed to unhash a busy 2316 * directory. In this case, however, we can do it - no aliasing problems 2317 * due to the way we treat inodes. 2318 */ 2319 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) 2320 { 2321 struct inode *inode = dentry->d_inode; 2322 struct task_struct *task = get_proc_task(inode); 2323 if (task) { 2324 put_task_struct(task); 2325 return 1; 2326 } 2327 d_drop(dentry); 2328 return 0; 2329 } 2330 2331 static const struct dentry_operations proc_base_dentry_operations = 2332 { 2333 .d_revalidate = proc_base_revalidate, 2334 .d_delete = pid_delete_dentry, 2335 }; 2336 2337 static struct dentry *proc_base_instantiate(struct inode *dir, 2338 struct dentry *dentry, struct task_struct *task, const void *ptr) 2339 { 2340 const struct pid_entry *p = ptr; 2341 struct inode *inode; 2342 struct proc_inode *ei; 2343 struct dentry *error = ERR_PTR(-EINVAL); 2344 2345 /* Allocate the inode */ 2346 error = ERR_PTR(-ENOMEM); 2347 inode = new_inode(dir->i_sb); 2348 if (!inode) 2349 goto out; 2350 2351 /* Initialize the inode */ 2352 ei = PROC_I(inode); 2353 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2354 2355 /* 2356 * grab the reference to the task. 2357 */ 2358 ei->pid = get_task_pid(task, PIDTYPE_PID); 2359 if (!ei->pid) 2360 goto out_iput; 2361 2362 inode->i_mode = p->mode; 2363 if (S_ISDIR(inode->i_mode)) 2364 inode->i_nlink = 2; 2365 if (S_ISLNK(inode->i_mode)) 2366 inode->i_size = 64; 2367 if (p->iop) 2368 inode->i_op = p->iop; 2369 if (p->fop) 2370 inode->i_fop = p->fop; 2371 ei->op = p->op; 2372 dentry->d_op = &proc_base_dentry_operations; 2373 d_add(dentry, inode); 2374 error = NULL; 2375 out: 2376 return error; 2377 out_iput: 2378 iput(inode); 2379 goto out; 2380 } 2381 2382 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2383 { 2384 struct dentry *error; 2385 struct task_struct *task = get_proc_task(dir); 2386 const struct pid_entry *p, *last; 2387 2388 error = ERR_PTR(-ENOENT); 2389 2390 if (!task) 2391 goto out_no_task; 2392 2393 /* Lookup the directory entry */ 2394 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2395 for (p = proc_base_stuff; p <= last; p++) { 2396 if (p->len != dentry->d_name.len) 2397 continue; 2398 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2399 break; 2400 } 2401 if (p > last) 2402 goto out; 2403 2404 error = proc_base_instantiate(dir, dentry, task, p); 2405 2406 out: 2407 put_task_struct(task); 2408 out_no_task: 2409 return error; 2410 } 2411 2412 static int proc_base_fill_cache(struct file *filp, void *dirent, 2413 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2414 { 2415 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2416 proc_base_instantiate, task, p); 2417 } 2418 2419 #ifdef CONFIG_TASK_IO_ACCOUNTING 2420 static int do_io_accounting(struct task_struct *task, char *buffer, int whole) 2421 { 2422 struct task_io_accounting acct = task->ioac; 2423 unsigned long flags; 2424 2425 if (whole && lock_task_sighand(task, &flags)) { 2426 struct task_struct *t = task; 2427 2428 task_io_accounting_add(&acct, &task->signal->ioac); 2429 while_each_thread(task, t) 2430 task_io_accounting_add(&acct, &t->ioac); 2431 2432 unlock_task_sighand(task, &flags); 2433 } 2434 return sprintf(buffer, 2435 "rchar: %llu\n" 2436 "wchar: %llu\n" 2437 "syscr: %llu\n" 2438 "syscw: %llu\n" 2439 "read_bytes: %llu\n" 2440 "write_bytes: %llu\n" 2441 "cancelled_write_bytes: %llu\n", 2442 (unsigned long long)acct.rchar, 2443 (unsigned long long)acct.wchar, 2444 (unsigned long long)acct.syscr, 2445 (unsigned long long)acct.syscw, 2446 (unsigned long long)acct.read_bytes, 2447 (unsigned long long)acct.write_bytes, 2448 (unsigned long long)acct.cancelled_write_bytes); 2449 } 2450 2451 static int proc_tid_io_accounting(struct task_struct *task, char *buffer) 2452 { 2453 return do_io_accounting(task, buffer, 0); 2454 } 2455 2456 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer) 2457 { 2458 return do_io_accounting(task, buffer, 1); 2459 } 2460 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2461 2462 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2463 struct pid *pid, struct task_struct *task) 2464 { 2465 seq_printf(m, "%08x\n", task->personality); 2466 return 0; 2467 } 2468 2469 /* 2470 * Thread groups 2471 */ 2472 static const struct file_operations proc_task_operations; 2473 static const struct inode_operations proc_task_inode_operations; 2474 2475 static const struct pid_entry tgid_base_stuff[] = { 2476 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2477 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2478 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2479 #ifdef CONFIG_NET 2480 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2481 #endif 2482 REG("environ", S_IRUSR, proc_environ_operations), 2483 INF("auxv", S_IRUSR, proc_pid_auxv), 2484 ONE("status", S_IRUGO, proc_pid_status), 2485 ONE("personality", S_IRUSR, proc_pid_personality), 2486 INF("limits", S_IRUSR, proc_pid_limits), 2487 #ifdef CONFIG_SCHED_DEBUG 2488 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2489 #endif 2490 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2491 INF("syscall", S_IRUSR, proc_pid_syscall), 2492 #endif 2493 INF("cmdline", S_IRUGO, proc_pid_cmdline), 2494 ONE("stat", S_IRUGO, proc_tgid_stat), 2495 ONE("statm", S_IRUGO, proc_pid_statm), 2496 REG("maps", S_IRUGO, proc_maps_operations), 2497 #ifdef CONFIG_NUMA 2498 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 2499 #endif 2500 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2501 LNK("cwd", proc_cwd_link), 2502 LNK("root", proc_root_link), 2503 LNK("exe", proc_exe_link), 2504 REG("mounts", S_IRUGO, proc_mounts_operations), 2505 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2506 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2507 #ifdef CONFIG_PROC_PAGE_MONITOR 2508 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2509 REG("smaps", S_IRUGO, proc_smaps_operations), 2510 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2511 #endif 2512 #ifdef CONFIG_SECURITY 2513 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2514 #endif 2515 #ifdef CONFIG_KALLSYMS 2516 INF("wchan", S_IRUGO, proc_pid_wchan), 2517 #endif 2518 #ifdef CONFIG_STACKTRACE 2519 ONE("stack", S_IRUSR, proc_pid_stack), 2520 #endif 2521 #ifdef CONFIG_SCHEDSTATS 2522 INF("schedstat", S_IRUGO, proc_pid_schedstat), 2523 #endif 2524 #ifdef CONFIG_LATENCYTOP 2525 REG("latency", S_IRUGO, proc_lstats_operations), 2526 #endif 2527 #ifdef CONFIG_PROC_PID_CPUSET 2528 REG("cpuset", S_IRUGO, proc_cpuset_operations), 2529 #endif 2530 #ifdef CONFIG_CGROUPS 2531 REG("cgroup", S_IRUGO, proc_cgroup_operations), 2532 #endif 2533 INF("oom_score", S_IRUGO, proc_oom_score), 2534 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 2535 #ifdef CONFIG_AUDITSYSCALL 2536 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2537 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2538 #endif 2539 #ifdef CONFIG_FAULT_INJECTION 2540 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2541 #endif 2542 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2543 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2544 #endif 2545 #ifdef CONFIG_TASK_IO_ACCOUNTING 2546 INF("io", S_IRUGO, proc_tgid_io_accounting), 2547 #endif 2548 }; 2549 2550 static int proc_tgid_base_readdir(struct file * filp, 2551 void * dirent, filldir_t filldir) 2552 { 2553 return proc_pident_readdir(filp,dirent,filldir, 2554 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2555 } 2556 2557 static const struct file_operations proc_tgid_base_operations = { 2558 .read = generic_read_dir, 2559 .readdir = proc_tgid_base_readdir, 2560 }; 2561 2562 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2563 return proc_pident_lookup(dir, dentry, 2564 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2565 } 2566 2567 static const struct inode_operations proc_tgid_base_inode_operations = { 2568 .lookup = proc_tgid_base_lookup, 2569 .getattr = pid_getattr, 2570 .setattr = proc_setattr, 2571 }; 2572 2573 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2574 { 2575 struct dentry *dentry, *leader, *dir; 2576 char buf[PROC_NUMBUF]; 2577 struct qstr name; 2578 2579 name.name = buf; 2580 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2581 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2582 if (dentry) { 2583 if (!(current->flags & PF_EXITING)) 2584 shrink_dcache_parent(dentry); 2585 d_drop(dentry); 2586 dput(dentry); 2587 } 2588 2589 if (tgid == 0) 2590 goto out; 2591 2592 name.name = buf; 2593 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2594 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2595 if (!leader) 2596 goto out; 2597 2598 name.name = "task"; 2599 name.len = strlen(name.name); 2600 dir = d_hash_and_lookup(leader, &name); 2601 if (!dir) 2602 goto out_put_leader; 2603 2604 name.name = buf; 2605 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2606 dentry = d_hash_and_lookup(dir, &name); 2607 if (dentry) { 2608 shrink_dcache_parent(dentry); 2609 d_drop(dentry); 2610 dput(dentry); 2611 } 2612 2613 dput(dir); 2614 out_put_leader: 2615 dput(leader); 2616 out: 2617 return; 2618 } 2619 2620 /** 2621 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2622 * @task: task that should be flushed. 2623 * 2624 * When flushing dentries from proc, one needs to flush them from global 2625 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2626 * in. This call is supposed to do all of this job. 2627 * 2628 * Looks in the dcache for 2629 * /proc/@pid 2630 * /proc/@tgid/task/@pid 2631 * if either directory is present flushes it and all of it'ts children 2632 * from the dcache. 2633 * 2634 * It is safe and reasonable to cache /proc entries for a task until 2635 * that task exits. After that they just clog up the dcache with 2636 * useless entries, possibly causing useful dcache entries to be 2637 * flushed instead. This routine is proved to flush those useless 2638 * dcache entries at process exit time. 2639 * 2640 * NOTE: This routine is just an optimization so it does not guarantee 2641 * that no dcache entries will exist at process exit time it 2642 * just makes it very unlikely that any will persist. 2643 */ 2644 2645 void proc_flush_task(struct task_struct *task) 2646 { 2647 int i; 2648 struct pid *pid, *tgid = NULL; 2649 struct upid *upid; 2650 2651 pid = task_pid(task); 2652 if (thread_group_leader(task)) 2653 tgid = task_tgid(task); 2654 2655 for (i = 0; i <= pid->level; i++) { 2656 upid = &pid->numbers[i]; 2657 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 2658 tgid ? tgid->numbers[i].nr : 0); 2659 } 2660 2661 upid = &pid->numbers[pid->level]; 2662 if (upid->nr == 1) 2663 pid_ns_release_proc(upid->ns); 2664 } 2665 2666 static struct dentry *proc_pid_instantiate(struct inode *dir, 2667 struct dentry * dentry, 2668 struct task_struct *task, const void *ptr) 2669 { 2670 struct dentry *error = ERR_PTR(-ENOENT); 2671 struct inode *inode; 2672 2673 inode = proc_pid_make_inode(dir->i_sb, task); 2674 if (!inode) 2675 goto out; 2676 2677 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2678 inode->i_op = &proc_tgid_base_inode_operations; 2679 inode->i_fop = &proc_tgid_base_operations; 2680 inode->i_flags|=S_IMMUTABLE; 2681 2682 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff, 2683 ARRAY_SIZE(tgid_base_stuff)); 2684 2685 dentry->d_op = &pid_dentry_operations; 2686 2687 d_add(dentry, inode); 2688 /* Close the race of the process dying before we return the dentry */ 2689 if (pid_revalidate(dentry, NULL)) 2690 error = NULL; 2691 out: 2692 return error; 2693 } 2694 2695 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2696 { 2697 struct dentry *result = ERR_PTR(-ENOENT); 2698 struct task_struct *task; 2699 unsigned tgid; 2700 struct pid_namespace *ns; 2701 2702 result = proc_base_lookup(dir, dentry); 2703 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 2704 goto out; 2705 2706 tgid = name_to_int(dentry); 2707 if (tgid == ~0U) 2708 goto out; 2709 2710 ns = dentry->d_sb->s_fs_info; 2711 rcu_read_lock(); 2712 task = find_task_by_pid_ns(tgid, ns); 2713 if (task) 2714 get_task_struct(task); 2715 rcu_read_unlock(); 2716 if (!task) 2717 goto out; 2718 2719 result = proc_pid_instantiate(dir, dentry, task, NULL); 2720 put_task_struct(task); 2721 out: 2722 return result; 2723 } 2724 2725 /* 2726 * Find the first task with tgid >= tgid 2727 * 2728 */ 2729 struct tgid_iter { 2730 unsigned int tgid; 2731 struct task_struct *task; 2732 }; 2733 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 2734 { 2735 struct pid *pid; 2736 2737 if (iter.task) 2738 put_task_struct(iter.task); 2739 rcu_read_lock(); 2740 retry: 2741 iter.task = NULL; 2742 pid = find_ge_pid(iter.tgid, ns); 2743 if (pid) { 2744 iter.tgid = pid_nr_ns(pid, ns); 2745 iter.task = pid_task(pid, PIDTYPE_PID); 2746 /* What we to know is if the pid we have find is the 2747 * pid of a thread_group_leader. Testing for task 2748 * being a thread_group_leader is the obvious thing 2749 * todo but there is a window when it fails, due to 2750 * the pid transfer logic in de_thread. 2751 * 2752 * So we perform the straight forward test of seeing 2753 * if the pid we have found is the pid of a thread 2754 * group leader, and don't worry if the task we have 2755 * found doesn't happen to be a thread group leader. 2756 * As we don't care in the case of readdir. 2757 */ 2758 if (!iter.task || !has_group_leader_pid(iter.task)) { 2759 iter.tgid += 1; 2760 goto retry; 2761 } 2762 get_task_struct(iter.task); 2763 } 2764 rcu_read_unlock(); 2765 return iter; 2766 } 2767 2768 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 2769 2770 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2771 struct tgid_iter iter) 2772 { 2773 char name[PROC_NUMBUF]; 2774 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 2775 return proc_fill_cache(filp, dirent, filldir, name, len, 2776 proc_pid_instantiate, iter.task, NULL); 2777 } 2778 2779 /* for the /proc/ directory itself, after non-process stuff has been done */ 2780 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 2781 { 2782 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; 2783 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode); 2784 struct tgid_iter iter; 2785 struct pid_namespace *ns; 2786 2787 if (!reaper) 2788 goto out_no_task; 2789 2790 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 2791 const struct pid_entry *p = &proc_base_stuff[nr]; 2792 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 2793 goto out; 2794 } 2795 2796 ns = filp->f_dentry->d_sb->s_fs_info; 2797 iter.task = NULL; 2798 iter.tgid = filp->f_pos - TGID_OFFSET; 2799 for (iter = next_tgid(ns, iter); 2800 iter.task; 2801 iter.tgid += 1, iter = next_tgid(ns, iter)) { 2802 filp->f_pos = iter.tgid + TGID_OFFSET; 2803 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) { 2804 put_task_struct(iter.task); 2805 goto out; 2806 } 2807 } 2808 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 2809 out: 2810 put_task_struct(reaper); 2811 out_no_task: 2812 return 0; 2813 } 2814 2815 /* 2816 * Tasks 2817 */ 2818 static const struct pid_entry tid_base_stuff[] = { 2819 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2820 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fd_operations), 2821 REG("environ", S_IRUSR, proc_environ_operations), 2822 INF("auxv", S_IRUSR, proc_pid_auxv), 2823 ONE("status", S_IRUGO, proc_pid_status), 2824 ONE("personality", S_IRUSR, proc_pid_personality), 2825 INF("limits", S_IRUSR, proc_pid_limits), 2826 #ifdef CONFIG_SCHED_DEBUG 2827 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2828 #endif 2829 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2830 INF("syscall", S_IRUSR, proc_pid_syscall), 2831 #endif 2832 INF("cmdline", S_IRUGO, proc_pid_cmdline), 2833 ONE("stat", S_IRUGO, proc_tid_stat), 2834 ONE("statm", S_IRUGO, proc_pid_statm), 2835 REG("maps", S_IRUGO, proc_maps_operations), 2836 #ifdef CONFIG_NUMA 2837 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 2838 #endif 2839 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2840 LNK("cwd", proc_cwd_link), 2841 LNK("root", proc_root_link), 2842 LNK("exe", proc_exe_link), 2843 REG("mounts", S_IRUGO, proc_mounts_operations), 2844 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2845 #ifdef CONFIG_PROC_PAGE_MONITOR 2846 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2847 REG("smaps", S_IRUGO, proc_smaps_operations), 2848 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2849 #endif 2850 #ifdef CONFIG_SECURITY 2851 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2852 #endif 2853 #ifdef CONFIG_KALLSYMS 2854 INF("wchan", S_IRUGO, proc_pid_wchan), 2855 #endif 2856 #ifdef CONFIG_STACKTRACE 2857 ONE("stack", S_IRUSR, proc_pid_stack), 2858 #endif 2859 #ifdef CONFIG_SCHEDSTATS 2860 INF("schedstat", S_IRUGO, proc_pid_schedstat), 2861 #endif 2862 #ifdef CONFIG_LATENCYTOP 2863 REG("latency", S_IRUGO, proc_lstats_operations), 2864 #endif 2865 #ifdef CONFIG_PROC_PID_CPUSET 2866 REG("cpuset", S_IRUGO, proc_cpuset_operations), 2867 #endif 2868 #ifdef CONFIG_CGROUPS 2869 REG("cgroup", S_IRUGO, proc_cgroup_operations), 2870 #endif 2871 INF("oom_score", S_IRUGO, proc_oom_score), 2872 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 2873 #ifdef CONFIG_AUDITSYSCALL 2874 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2875 REG("sessionid", S_IRUSR, proc_sessionid_operations), 2876 #endif 2877 #ifdef CONFIG_FAULT_INJECTION 2878 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2879 #endif 2880 #ifdef CONFIG_TASK_IO_ACCOUNTING 2881 INF("io", S_IRUGO, proc_tid_io_accounting), 2882 #endif 2883 }; 2884 2885 static int proc_tid_base_readdir(struct file * filp, 2886 void * dirent, filldir_t filldir) 2887 { 2888 return proc_pident_readdir(filp,dirent,filldir, 2889 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 2890 } 2891 2892 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2893 return proc_pident_lookup(dir, dentry, 2894 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 2895 } 2896 2897 static const struct file_operations proc_tid_base_operations = { 2898 .read = generic_read_dir, 2899 .readdir = proc_tid_base_readdir, 2900 }; 2901 2902 static const struct inode_operations proc_tid_base_inode_operations = { 2903 .lookup = proc_tid_base_lookup, 2904 .getattr = pid_getattr, 2905 .setattr = proc_setattr, 2906 }; 2907 2908 static struct dentry *proc_task_instantiate(struct inode *dir, 2909 struct dentry *dentry, struct task_struct *task, const void *ptr) 2910 { 2911 struct dentry *error = ERR_PTR(-ENOENT); 2912 struct inode *inode; 2913 inode = proc_pid_make_inode(dir->i_sb, task); 2914 2915 if (!inode) 2916 goto out; 2917 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2918 inode->i_op = &proc_tid_base_inode_operations; 2919 inode->i_fop = &proc_tid_base_operations; 2920 inode->i_flags|=S_IMMUTABLE; 2921 2922 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff, 2923 ARRAY_SIZE(tid_base_stuff)); 2924 2925 dentry->d_op = &pid_dentry_operations; 2926 2927 d_add(dentry, inode); 2928 /* Close the race of the process dying before we return the dentry */ 2929 if (pid_revalidate(dentry, NULL)) 2930 error = NULL; 2931 out: 2932 return error; 2933 } 2934 2935 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2936 { 2937 struct dentry *result = ERR_PTR(-ENOENT); 2938 struct task_struct *task; 2939 struct task_struct *leader = get_proc_task(dir); 2940 unsigned tid; 2941 struct pid_namespace *ns; 2942 2943 if (!leader) 2944 goto out_no_task; 2945 2946 tid = name_to_int(dentry); 2947 if (tid == ~0U) 2948 goto out; 2949 2950 ns = dentry->d_sb->s_fs_info; 2951 rcu_read_lock(); 2952 task = find_task_by_pid_ns(tid, ns); 2953 if (task) 2954 get_task_struct(task); 2955 rcu_read_unlock(); 2956 if (!task) 2957 goto out; 2958 if (!same_thread_group(leader, task)) 2959 goto out_drop_task; 2960 2961 result = proc_task_instantiate(dir, dentry, task, NULL); 2962 out_drop_task: 2963 put_task_struct(task); 2964 out: 2965 put_task_struct(leader); 2966 out_no_task: 2967 return result; 2968 } 2969 2970 /* 2971 * Find the first tid of a thread group to return to user space. 2972 * 2973 * Usually this is just the thread group leader, but if the users 2974 * buffer was too small or there was a seek into the middle of the 2975 * directory we have more work todo. 2976 * 2977 * In the case of a short read we start with find_task_by_pid. 2978 * 2979 * In the case of a seek we start with the leader and walk nr 2980 * threads past it. 2981 */ 2982 static struct task_struct *first_tid(struct task_struct *leader, 2983 int tid, int nr, struct pid_namespace *ns) 2984 { 2985 struct task_struct *pos; 2986 2987 rcu_read_lock(); 2988 /* Attempt to start with the pid of a thread */ 2989 if (tid && (nr > 0)) { 2990 pos = find_task_by_pid_ns(tid, ns); 2991 if (pos && (pos->group_leader == leader)) 2992 goto found; 2993 } 2994 2995 /* If nr exceeds the number of threads there is nothing todo */ 2996 pos = NULL; 2997 if (nr && nr >= get_nr_threads(leader)) 2998 goto out; 2999 3000 /* If we haven't found our starting place yet start 3001 * with the leader and walk nr threads forward. 3002 */ 3003 for (pos = leader; nr > 0; --nr) { 3004 pos = next_thread(pos); 3005 if (pos == leader) { 3006 pos = NULL; 3007 goto out; 3008 } 3009 } 3010 found: 3011 get_task_struct(pos); 3012 out: 3013 rcu_read_unlock(); 3014 return pos; 3015 } 3016 3017 /* 3018 * Find the next thread in the thread list. 3019 * Return NULL if there is an error or no next thread. 3020 * 3021 * The reference to the input task_struct is released. 3022 */ 3023 static struct task_struct *next_tid(struct task_struct *start) 3024 { 3025 struct task_struct *pos = NULL; 3026 rcu_read_lock(); 3027 if (pid_alive(start)) { 3028 pos = next_thread(start); 3029 if (thread_group_leader(pos)) 3030 pos = NULL; 3031 else 3032 get_task_struct(pos); 3033 } 3034 rcu_read_unlock(); 3035 put_task_struct(start); 3036 return pos; 3037 } 3038 3039 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3040 struct task_struct *task, int tid) 3041 { 3042 char name[PROC_NUMBUF]; 3043 int len = snprintf(name, sizeof(name), "%d", tid); 3044 return proc_fill_cache(filp, dirent, filldir, name, len, 3045 proc_task_instantiate, task, NULL); 3046 } 3047 3048 /* for the /proc/TGID/task/ directories */ 3049 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 3050 { 3051 struct dentry *dentry = filp->f_path.dentry; 3052 struct inode *inode = dentry->d_inode; 3053 struct task_struct *leader = NULL; 3054 struct task_struct *task; 3055 int retval = -ENOENT; 3056 ino_t ino; 3057 int tid; 3058 struct pid_namespace *ns; 3059 3060 task = get_proc_task(inode); 3061 if (!task) 3062 goto out_no_task; 3063 rcu_read_lock(); 3064 if (pid_alive(task)) { 3065 leader = task->group_leader; 3066 get_task_struct(leader); 3067 } 3068 rcu_read_unlock(); 3069 put_task_struct(task); 3070 if (!leader) 3071 goto out_no_task; 3072 retval = 0; 3073 3074 switch ((unsigned long)filp->f_pos) { 3075 case 0: 3076 ino = inode->i_ino; 3077 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0) 3078 goto out; 3079 filp->f_pos++; 3080 /* fall through */ 3081 case 1: 3082 ino = parent_ino(dentry); 3083 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0) 3084 goto out; 3085 filp->f_pos++; 3086 /* fall through */ 3087 } 3088 3089 /* f_version caches the tgid value that the last readdir call couldn't 3090 * return. lseek aka telldir automagically resets f_version to 0. 3091 */ 3092 ns = filp->f_dentry->d_sb->s_fs_info; 3093 tid = (int)filp->f_version; 3094 filp->f_version = 0; 3095 for (task = first_tid(leader, tid, filp->f_pos - 2, ns); 3096 task; 3097 task = next_tid(task), filp->f_pos++) { 3098 tid = task_pid_nr_ns(task, ns); 3099 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 3100 /* returning this tgid failed, save it as the first 3101 * pid for the next readir call */ 3102 filp->f_version = (u64)tid; 3103 put_task_struct(task); 3104 break; 3105 } 3106 } 3107 out: 3108 put_task_struct(leader); 3109 out_no_task: 3110 return retval; 3111 } 3112 3113 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3114 { 3115 struct inode *inode = dentry->d_inode; 3116 struct task_struct *p = get_proc_task(inode); 3117 generic_fillattr(inode, stat); 3118 3119 if (p) { 3120 stat->nlink += get_nr_threads(p); 3121 put_task_struct(p); 3122 } 3123 3124 return 0; 3125 } 3126 3127 static const struct inode_operations proc_task_inode_operations = { 3128 .lookup = proc_task_lookup, 3129 .getattr = proc_task_getattr, 3130 .setattr = proc_setattr, 3131 }; 3132 3133 static const struct file_operations proc_task_operations = { 3134 .read = generic_read_dir, 3135 .readdir = proc_task_readdir, 3136 }; 3137