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