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 task_lock(task); 1007 if (task->mm) 1008 oom_adjust = task->mm->oom_adj; 1009 else 1010 oom_adjust = OOM_DISABLE; 1011 task_unlock(task); 1012 put_task_struct(task); 1013 1014 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); 1015 1016 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1017 } 1018 1019 static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 1020 size_t count, loff_t *ppos) 1021 { 1022 struct task_struct *task; 1023 char buffer[PROC_NUMBUF], *end; 1024 int oom_adjust; 1025 1026 memset(buffer, 0, sizeof(buffer)); 1027 if (count > sizeof(buffer) - 1) 1028 count = sizeof(buffer) - 1; 1029 if (copy_from_user(buffer, buf, count)) 1030 return -EFAULT; 1031 oom_adjust = simple_strtol(buffer, &end, 0); 1032 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && 1033 oom_adjust != OOM_DISABLE) 1034 return -EINVAL; 1035 if (*end == '\n') 1036 end++; 1037 task = get_proc_task(file->f_path.dentry->d_inode); 1038 if (!task) 1039 return -ESRCH; 1040 task_lock(task); 1041 if (!task->mm) { 1042 task_unlock(task); 1043 put_task_struct(task); 1044 return -EINVAL; 1045 } 1046 if (oom_adjust < task->mm->oom_adj && !capable(CAP_SYS_RESOURCE)) { 1047 task_unlock(task); 1048 put_task_struct(task); 1049 return -EACCES; 1050 } 1051 task->mm->oom_adj = oom_adjust; 1052 task_unlock(task); 1053 put_task_struct(task); 1054 if (end - buffer == 0) 1055 return -EIO; 1056 return end - buffer; 1057 } 1058 1059 static const struct file_operations proc_oom_adjust_operations = { 1060 .read = oom_adjust_read, 1061 .write = oom_adjust_write, 1062 }; 1063 1064 #ifdef CONFIG_AUDITSYSCALL 1065 #define TMPBUFLEN 21 1066 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1067 size_t count, loff_t *ppos) 1068 { 1069 struct inode * inode = file->f_path.dentry->d_inode; 1070 struct task_struct *task = get_proc_task(inode); 1071 ssize_t length; 1072 char tmpbuf[TMPBUFLEN]; 1073 1074 if (!task) 1075 return -ESRCH; 1076 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1077 audit_get_loginuid(task)); 1078 put_task_struct(task); 1079 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1080 } 1081 1082 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1083 size_t count, loff_t *ppos) 1084 { 1085 struct inode * inode = file->f_path.dentry->d_inode; 1086 char *page, *tmp; 1087 ssize_t length; 1088 uid_t loginuid; 1089 1090 if (!capable(CAP_AUDIT_CONTROL)) 1091 return -EPERM; 1092 1093 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) 1094 return -EPERM; 1095 1096 if (count >= PAGE_SIZE) 1097 count = PAGE_SIZE - 1; 1098 1099 if (*ppos != 0) { 1100 /* No partial writes. */ 1101 return -EINVAL; 1102 } 1103 page = (char*)__get_free_page(GFP_TEMPORARY); 1104 if (!page) 1105 return -ENOMEM; 1106 length = -EFAULT; 1107 if (copy_from_user(page, buf, count)) 1108 goto out_free_page; 1109 1110 page[count] = '\0'; 1111 loginuid = simple_strtoul(page, &tmp, 10); 1112 if (tmp == page) { 1113 length = -EINVAL; 1114 goto out_free_page; 1115 1116 } 1117 length = audit_set_loginuid(current, loginuid); 1118 if (likely(length == 0)) 1119 length = count; 1120 1121 out_free_page: 1122 free_page((unsigned long) page); 1123 return length; 1124 } 1125 1126 static const struct file_operations proc_loginuid_operations = { 1127 .read = proc_loginuid_read, 1128 .write = proc_loginuid_write, 1129 }; 1130 1131 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1132 size_t count, loff_t *ppos) 1133 { 1134 struct inode * inode = file->f_path.dentry->d_inode; 1135 struct task_struct *task = get_proc_task(inode); 1136 ssize_t length; 1137 char tmpbuf[TMPBUFLEN]; 1138 1139 if (!task) 1140 return -ESRCH; 1141 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1142 audit_get_sessionid(task)); 1143 put_task_struct(task); 1144 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1145 } 1146 1147 static const struct file_operations proc_sessionid_operations = { 1148 .read = proc_sessionid_read, 1149 }; 1150 #endif 1151 1152 #ifdef CONFIG_FAULT_INJECTION 1153 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1154 size_t count, loff_t *ppos) 1155 { 1156 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1157 char buffer[PROC_NUMBUF]; 1158 size_t len; 1159 int make_it_fail; 1160 1161 if (!task) 1162 return -ESRCH; 1163 make_it_fail = task->make_it_fail; 1164 put_task_struct(task); 1165 1166 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1167 1168 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1169 } 1170 1171 static ssize_t proc_fault_inject_write(struct file * file, 1172 const char __user * buf, size_t count, loff_t *ppos) 1173 { 1174 struct task_struct *task; 1175 char buffer[PROC_NUMBUF], *end; 1176 int make_it_fail; 1177 1178 if (!capable(CAP_SYS_RESOURCE)) 1179 return -EPERM; 1180 memset(buffer, 0, sizeof(buffer)); 1181 if (count > sizeof(buffer) - 1) 1182 count = sizeof(buffer) - 1; 1183 if (copy_from_user(buffer, buf, count)) 1184 return -EFAULT; 1185 make_it_fail = simple_strtol(buffer, &end, 0); 1186 if (*end == '\n') 1187 end++; 1188 task = get_proc_task(file->f_dentry->d_inode); 1189 if (!task) 1190 return -ESRCH; 1191 task->make_it_fail = make_it_fail; 1192 put_task_struct(task); 1193 if (end - buffer == 0) 1194 return -EIO; 1195 return end - buffer; 1196 } 1197 1198 static const struct file_operations proc_fault_inject_operations = { 1199 .read = proc_fault_inject_read, 1200 .write = proc_fault_inject_write, 1201 }; 1202 #endif 1203 1204 1205 #ifdef CONFIG_SCHED_DEBUG 1206 /* 1207 * Print out various scheduling related per-task fields: 1208 */ 1209 static int sched_show(struct seq_file *m, void *v) 1210 { 1211 struct inode *inode = m->private; 1212 struct task_struct *p; 1213 1214 p = get_proc_task(inode); 1215 if (!p) 1216 return -ESRCH; 1217 proc_sched_show_task(p, m); 1218 1219 put_task_struct(p); 1220 1221 return 0; 1222 } 1223 1224 static ssize_t 1225 sched_write(struct file *file, const char __user *buf, 1226 size_t count, loff_t *offset) 1227 { 1228 struct inode *inode = file->f_path.dentry->d_inode; 1229 struct task_struct *p; 1230 1231 p = get_proc_task(inode); 1232 if (!p) 1233 return -ESRCH; 1234 proc_sched_set_task(p); 1235 1236 put_task_struct(p); 1237 1238 return count; 1239 } 1240 1241 static int sched_open(struct inode *inode, struct file *filp) 1242 { 1243 int ret; 1244 1245 ret = single_open(filp, sched_show, NULL); 1246 if (!ret) { 1247 struct seq_file *m = filp->private_data; 1248 1249 m->private = inode; 1250 } 1251 return ret; 1252 } 1253 1254 static const struct file_operations proc_pid_sched_operations = { 1255 .open = sched_open, 1256 .read = seq_read, 1257 .write = sched_write, 1258 .llseek = seq_lseek, 1259 .release = single_release, 1260 }; 1261 1262 #endif 1263 1264 /* 1265 * We added or removed a vma mapping the executable. The vmas are only mapped 1266 * during exec and are not mapped with the mmap system call. 1267 * Callers must hold down_write() on the mm's mmap_sem for these 1268 */ 1269 void added_exe_file_vma(struct mm_struct *mm) 1270 { 1271 mm->num_exe_file_vmas++; 1272 } 1273 1274 void removed_exe_file_vma(struct mm_struct *mm) 1275 { 1276 mm->num_exe_file_vmas--; 1277 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){ 1278 fput(mm->exe_file); 1279 mm->exe_file = NULL; 1280 } 1281 1282 } 1283 1284 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) 1285 { 1286 if (new_exe_file) 1287 get_file(new_exe_file); 1288 if (mm->exe_file) 1289 fput(mm->exe_file); 1290 mm->exe_file = new_exe_file; 1291 mm->num_exe_file_vmas = 0; 1292 } 1293 1294 struct file *get_mm_exe_file(struct mm_struct *mm) 1295 { 1296 struct file *exe_file; 1297 1298 /* We need mmap_sem to protect against races with removal of 1299 * VM_EXECUTABLE vmas */ 1300 down_read(&mm->mmap_sem); 1301 exe_file = mm->exe_file; 1302 if (exe_file) 1303 get_file(exe_file); 1304 up_read(&mm->mmap_sem); 1305 return exe_file; 1306 } 1307 1308 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm) 1309 { 1310 /* It's safe to write the exe_file pointer without exe_file_lock because 1311 * this is called during fork when the task is not yet in /proc */ 1312 newmm->exe_file = get_mm_exe_file(oldmm); 1313 } 1314 1315 static int proc_exe_link(struct inode *inode, struct path *exe_path) 1316 { 1317 struct task_struct *task; 1318 struct mm_struct *mm; 1319 struct file *exe_file; 1320 1321 task = get_proc_task(inode); 1322 if (!task) 1323 return -ENOENT; 1324 mm = get_task_mm(task); 1325 put_task_struct(task); 1326 if (!mm) 1327 return -ENOENT; 1328 exe_file = get_mm_exe_file(mm); 1329 mmput(mm); 1330 if (exe_file) { 1331 *exe_path = exe_file->f_path; 1332 path_get(&exe_file->f_path); 1333 fput(exe_file); 1334 return 0; 1335 } else 1336 return -ENOENT; 1337 } 1338 1339 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1340 { 1341 struct inode *inode = dentry->d_inode; 1342 int error = -EACCES; 1343 1344 /* We don't need a base pointer in the /proc filesystem */ 1345 path_put(&nd->path); 1346 1347 /* Are we allowed to snoop on the tasks file descriptors? */ 1348 if (!proc_fd_access_allowed(inode)) 1349 goto out; 1350 1351 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path); 1352 nd->last_type = LAST_BIND; 1353 out: 1354 return ERR_PTR(error); 1355 } 1356 1357 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1358 { 1359 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1360 char *pathname; 1361 int len; 1362 1363 if (!tmp) 1364 return -ENOMEM; 1365 1366 pathname = d_path(path, tmp, PAGE_SIZE); 1367 len = PTR_ERR(pathname); 1368 if (IS_ERR(pathname)) 1369 goto out; 1370 len = tmp + PAGE_SIZE - 1 - pathname; 1371 1372 if (len > buflen) 1373 len = buflen; 1374 if (copy_to_user(buffer, pathname, len)) 1375 len = -EFAULT; 1376 out: 1377 free_page((unsigned long)tmp); 1378 return len; 1379 } 1380 1381 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1382 { 1383 int error = -EACCES; 1384 struct inode *inode = dentry->d_inode; 1385 struct path path; 1386 1387 /* Are we allowed to snoop on the tasks file descriptors? */ 1388 if (!proc_fd_access_allowed(inode)) 1389 goto out; 1390 1391 error = PROC_I(inode)->op.proc_get_link(inode, &path); 1392 if (error) 1393 goto out; 1394 1395 error = do_proc_readlink(&path, buffer, buflen); 1396 path_put(&path); 1397 out: 1398 return error; 1399 } 1400 1401 static const struct inode_operations proc_pid_link_inode_operations = { 1402 .readlink = proc_pid_readlink, 1403 .follow_link = proc_pid_follow_link, 1404 .setattr = proc_setattr, 1405 }; 1406 1407 1408 /* building an inode */ 1409 1410 static int task_dumpable(struct task_struct *task) 1411 { 1412 int dumpable = 0; 1413 struct mm_struct *mm; 1414 1415 task_lock(task); 1416 mm = task->mm; 1417 if (mm) 1418 dumpable = get_dumpable(mm); 1419 task_unlock(task); 1420 if(dumpable == 1) 1421 return 1; 1422 return 0; 1423 } 1424 1425 1426 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1427 { 1428 struct inode * inode; 1429 struct proc_inode *ei; 1430 const struct cred *cred; 1431 1432 /* We need a new inode */ 1433 1434 inode = new_inode(sb); 1435 if (!inode) 1436 goto out; 1437 1438 /* Common stuff */ 1439 ei = PROC_I(inode); 1440 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1441 inode->i_op = &proc_def_inode_operations; 1442 1443 /* 1444 * grab the reference to task. 1445 */ 1446 ei->pid = get_task_pid(task, PIDTYPE_PID); 1447 if (!ei->pid) 1448 goto out_unlock; 1449 1450 if (task_dumpable(task)) { 1451 rcu_read_lock(); 1452 cred = __task_cred(task); 1453 inode->i_uid = cred->euid; 1454 inode->i_gid = cred->egid; 1455 rcu_read_unlock(); 1456 } 1457 security_task_to_inode(task, inode); 1458 1459 out: 1460 return inode; 1461 1462 out_unlock: 1463 iput(inode); 1464 return NULL; 1465 } 1466 1467 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1468 { 1469 struct inode *inode = dentry->d_inode; 1470 struct task_struct *task; 1471 const struct cred *cred; 1472 1473 generic_fillattr(inode, stat); 1474 1475 rcu_read_lock(); 1476 stat->uid = 0; 1477 stat->gid = 0; 1478 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1479 if (task) { 1480 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1481 task_dumpable(task)) { 1482 cred = __task_cred(task); 1483 stat->uid = cred->euid; 1484 stat->gid = cred->egid; 1485 } 1486 } 1487 rcu_read_unlock(); 1488 return 0; 1489 } 1490 1491 /* dentry stuff */ 1492 1493 /* 1494 * Exceptional case: normally we are not allowed to unhash a busy 1495 * directory. In this case, however, we can do it - no aliasing problems 1496 * due to the way we treat inodes. 1497 * 1498 * Rewrite the inode's ownerships here because the owning task may have 1499 * performed a setuid(), etc. 1500 * 1501 * Before the /proc/pid/status file was created the only way to read 1502 * the effective uid of a /process was to stat /proc/pid. Reading 1503 * /proc/pid/status is slow enough that procps and other packages 1504 * kept stating /proc/pid. To keep the rules in /proc simple I have 1505 * made this apply to all per process world readable and executable 1506 * directories. 1507 */ 1508 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1509 { 1510 struct inode *inode = dentry->d_inode; 1511 struct task_struct *task = get_proc_task(inode); 1512 const struct cred *cred; 1513 1514 if (task) { 1515 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1516 task_dumpable(task)) { 1517 rcu_read_lock(); 1518 cred = __task_cred(task); 1519 inode->i_uid = cred->euid; 1520 inode->i_gid = cred->egid; 1521 rcu_read_unlock(); 1522 } else { 1523 inode->i_uid = 0; 1524 inode->i_gid = 0; 1525 } 1526 inode->i_mode &= ~(S_ISUID | S_ISGID); 1527 security_task_to_inode(task, inode); 1528 put_task_struct(task); 1529 return 1; 1530 } 1531 d_drop(dentry); 1532 return 0; 1533 } 1534 1535 static int pid_delete_dentry(struct dentry * dentry) 1536 { 1537 /* Is the task we represent dead? 1538 * If so, then don't put the dentry on the lru list, 1539 * kill it immediately. 1540 */ 1541 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1542 } 1543 1544 static const struct dentry_operations pid_dentry_operations = 1545 { 1546 .d_revalidate = pid_revalidate, 1547 .d_delete = pid_delete_dentry, 1548 }; 1549 1550 /* Lookups */ 1551 1552 typedef struct dentry *instantiate_t(struct inode *, struct dentry *, 1553 struct task_struct *, const void *); 1554 1555 /* 1556 * Fill a directory entry. 1557 * 1558 * If possible create the dcache entry and derive our inode number and 1559 * file type from dcache entry. 1560 * 1561 * Since all of the proc inode numbers are dynamically generated, the inode 1562 * numbers do not exist until the inode is cache. This means creating the 1563 * the dcache entry in readdir is necessary to keep the inode numbers 1564 * reported by readdir in sync with the inode numbers reported 1565 * by stat. 1566 */ 1567 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1568 char *name, int len, 1569 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1570 { 1571 struct dentry *child, *dir = filp->f_path.dentry; 1572 struct inode *inode; 1573 struct qstr qname; 1574 ino_t ino = 0; 1575 unsigned type = DT_UNKNOWN; 1576 1577 qname.name = name; 1578 qname.len = len; 1579 qname.hash = full_name_hash(name, len); 1580 1581 child = d_lookup(dir, &qname); 1582 if (!child) { 1583 struct dentry *new; 1584 new = d_alloc(dir, &qname); 1585 if (new) { 1586 child = instantiate(dir->d_inode, new, task, ptr); 1587 if (child) 1588 dput(new); 1589 else 1590 child = new; 1591 } 1592 } 1593 if (!child || IS_ERR(child) || !child->d_inode) 1594 goto end_instantiate; 1595 inode = child->d_inode; 1596 if (inode) { 1597 ino = inode->i_ino; 1598 type = inode->i_mode >> 12; 1599 } 1600 dput(child); 1601 end_instantiate: 1602 if (!ino) 1603 ino = find_inode_number(dir, &qname); 1604 if (!ino) 1605 ino = 1; 1606 return filldir(dirent, name, len, filp->f_pos, ino, type); 1607 } 1608 1609 static unsigned name_to_int(struct dentry *dentry) 1610 { 1611 const char *name = dentry->d_name.name; 1612 int len = dentry->d_name.len; 1613 unsigned n = 0; 1614 1615 if (len > 1 && *name == '0') 1616 goto out; 1617 while (len-- > 0) { 1618 unsigned c = *name++ - '0'; 1619 if (c > 9) 1620 goto out; 1621 if (n >= (~0U-9)/10) 1622 goto out; 1623 n *= 10; 1624 n += c; 1625 } 1626 return n; 1627 out: 1628 return ~0U; 1629 } 1630 1631 #define PROC_FDINFO_MAX 64 1632 1633 static int proc_fd_info(struct inode *inode, struct path *path, char *info) 1634 { 1635 struct task_struct *task = get_proc_task(inode); 1636 struct files_struct *files = NULL; 1637 struct file *file; 1638 int fd = proc_fd(inode); 1639 1640 if (task) { 1641 files = get_files_struct(task); 1642 put_task_struct(task); 1643 } 1644 if (files) { 1645 /* 1646 * We are not taking a ref to the file structure, so we must 1647 * hold ->file_lock. 1648 */ 1649 spin_lock(&files->file_lock); 1650 file = fcheck_files(files, fd); 1651 if (file) { 1652 if (path) { 1653 *path = file->f_path; 1654 path_get(&file->f_path); 1655 } 1656 if (info) 1657 snprintf(info, PROC_FDINFO_MAX, 1658 "pos:\t%lli\n" 1659 "flags:\t0%o\n", 1660 (long long) file->f_pos, 1661 file->f_flags); 1662 spin_unlock(&files->file_lock); 1663 put_files_struct(files); 1664 return 0; 1665 } 1666 spin_unlock(&files->file_lock); 1667 put_files_struct(files); 1668 } 1669 return -ENOENT; 1670 } 1671 1672 static int proc_fd_link(struct inode *inode, struct path *path) 1673 { 1674 return proc_fd_info(inode, path, NULL); 1675 } 1676 1677 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1678 { 1679 struct inode *inode = dentry->d_inode; 1680 struct task_struct *task = get_proc_task(inode); 1681 int fd = proc_fd(inode); 1682 struct files_struct *files; 1683 const struct cred *cred; 1684 1685 if (task) { 1686 files = get_files_struct(task); 1687 if (files) { 1688 rcu_read_lock(); 1689 if (fcheck_files(files, fd)) { 1690 rcu_read_unlock(); 1691 put_files_struct(files); 1692 if (task_dumpable(task)) { 1693 rcu_read_lock(); 1694 cred = __task_cred(task); 1695 inode->i_uid = cred->euid; 1696 inode->i_gid = cred->egid; 1697 rcu_read_unlock(); 1698 } else { 1699 inode->i_uid = 0; 1700 inode->i_gid = 0; 1701 } 1702 inode->i_mode &= ~(S_ISUID | S_ISGID); 1703 security_task_to_inode(task, inode); 1704 put_task_struct(task); 1705 return 1; 1706 } 1707 rcu_read_unlock(); 1708 put_files_struct(files); 1709 } 1710 put_task_struct(task); 1711 } 1712 d_drop(dentry); 1713 return 0; 1714 } 1715 1716 static const struct dentry_operations tid_fd_dentry_operations = 1717 { 1718 .d_revalidate = tid_fd_revalidate, 1719 .d_delete = pid_delete_dentry, 1720 }; 1721 1722 static struct dentry *proc_fd_instantiate(struct inode *dir, 1723 struct dentry *dentry, struct task_struct *task, const void *ptr) 1724 { 1725 unsigned fd = *(const unsigned *)ptr; 1726 struct file *file; 1727 struct files_struct *files; 1728 struct inode *inode; 1729 struct proc_inode *ei; 1730 struct dentry *error = ERR_PTR(-ENOENT); 1731 1732 inode = proc_pid_make_inode(dir->i_sb, task); 1733 if (!inode) 1734 goto out; 1735 ei = PROC_I(inode); 1736 ei->fd = fd; 1737 files = get_files_struct(task); 1738 if (!files) 1739 goto out_iput; 1740 inode->i_mode = S_IFLNK; 1741 1742 /* 1743 * We are not taking a ref to the file structure, so we must 1744 * hold ->file_lock. 1745 */ 1746 spin_lock(&files->file_lock); 1747 file = fcheck_files(files, fd); 1748 if (!file) 1749 goto out_unlock; 1750 if (file->f_mode & FMODE_READ) 1751 inode->i_mode |= S_IRUSR | S_IXUSR; 1752 if (file->f_mode & FMODE_WRITE) 1753 inode->i_mode |= S_IWUSR | S_IXUSR; 1754 spin_unlock(&files->file_lock); 1755 put_files_struct(files); 1756 1757 inode->i_op = &proc_pid_link_inode_operations; 1758 inode->i_size = 64; 1759 ei->op.proc_get_link = proc_fd_link; 1760 dentry->d_op = &tid_fd_dentry_operations; 1761 d_add(dentry, inode); 1762 /* Close the race of the process dying before we return the dentry */ 1763 if (tid_fd_revalidate(dentry, NULL)) 1764 error = NULL; 1765 1766 out: 1767 return error; 1768 out_unlock: 1769 spin_unlock(&files->file_lock); 1770 put_files_struct(files); 1771 out_iput: 1772 iput(inode); 1773 goto out; 1774 } 1775 1776 static struct dentry *proc_lookupfd_common(struct inode *dir, 1777 struct dentry *dentry, 1778 instantiate_t instantiate) 1779 { 1780 struct task_struct *task = get_proc_task(dir); 1781 unsigned fd = name_to_int(dentry); 1782 struct dentry *result = ERR_PTR(-ENOENT); 1783 1784 if (!task) 1785 goto out_no_task; 1786 if (fd == ~0U) 1787 goto out; 1788 1789 result = instantiate(dir, dentry, task, &fd); 1790 out: 1791 put_task_struct(task); 1792 out_no_task: 1793 return result; 1794 } 1795 1796 static int proc_readfd_common(struct file * filp, void * dirent, 1797 filldir_t filldir, instantiate_t instantiate) 1798 { 1799 struct dentry *dentry = filp->f_path.dentry; 1800 struct inode *inode = dentry->d_inode; 1801 struct task_struct *p = get_proc_task(inode); 1802 unsigned int fd, ino; 1803 int retval; 1804 struct files_struct * files; 1805 1806 retval = -ENOENT; 1807 if (!p) 1808 goto out_no_task; 1809 retval = 0; 1810 1811 fd = filp->f_pos; 1812 switch (fd) { 1813 case 0: 1814 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 1815 goto out; 1816 filp->f_pos++; 1817 case 1: 1818 ino = parent_ino(dentry); 1819 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 1820 goto out; 1821 filp->f_pos++; 1822 default: 1823 files = get_files_struct(p); 1824 if (!files) 1825 goto out; 1826 rcu_read_lock(); 1827 for (fd = filp->f_pos-2; 1828 fd < files_fdtable(files)->max_fds; 1829 fd++, filp->f_pos++) { 1830 char name[PROC_NUMBUF]; 1831 int len; 1832 1833 if (!fcheck_files(files, fd)) 1834 continue; 1835 rcu_read_unlock(); 1836 1837 len = snprintf(name, sizeof(name), "%d", fd); 1838 if (proc_fill_cache(filp, dirent, filldir, 1839 name, len, instantiate, 1840 p, &fd) < 0) { 1841 rcu_read_lock(); 1842 break; 1843 } 1844 rcu_read_lock(); 1845 } 1846 rcu_read_unlock(); 1847 put_files_struct(files); 1848 } 1849 out: 1850 put_task_struct(p); 1851 out_no_task: 1852 return retval; 1853 } 1854 1855 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 1856 struct nameidata *nd) 1857 { 1858 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 1859 } 1860 1861 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 1862 { 1863 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 1864 } 1865 1866 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 1867 size_t len, loff_t *ppos) 1868 { 1869 char tmp[PROC_FDINFO_MAX]; 1870 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); 1871 if (!err) 1872 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 1873 return err; 1874 } 1875 1876 static const struct file_operations proc_fdinfo_file_operations = { 1877 .open = nonseekable_open, 1878 .read = proc_fdinfo_read, 1879 }; 1880 1881 static const struct file_operations proc_fd_operations = { 1882 .read = generic_read_dir, 1883 .readdir = proc_readfd, 1884 }; 1885 1886 /* 1887 * /proc/pid/fd needs a special permission handler so that a process can still 1888 * access /proc/self/fd after it has executed a setuid(). 1889 */ 1890 static int proc_fd_permission(struct inode *inode, int mask) 1891 { 1892 int rv; 1893 1894 rv = generic_permission(inode, mask, NULL); 1895 if (rv == 0) 1896 return 0; 1897 if (task_pid(current) == proc_pid(inode)) 1898 rv = 0; 1899 return rv; 1900 } 1901 1902 /* 1903 * proc directories can do almost nothing.. 1904 */ 1905 static const struct inode_operations proc_fd_inode_operations = { 1906 .lookup = proc_lookupfd, 1907 .permission = proc_fd_permission, 1908 .setattr = proc_setattr, 1909 }; 1910 1911 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 1912 struct dentry *dentry, struct task_struct *task, const void *ptr) 1913 { 1914 unsigned fd = *(unsigned *)ptr; 1915 struct inode *inode; 1916 struct proc_inode *ei; 1917 struct dentry *error = ERR_PTR(-ENOENT); 1918 1919 inode = proc_pid_make_inode(dir->i_sb, task); 1920 if (!inode) 1921 goto out; 1922 ei = PROC_I(inode); 1923 ei->fd = fd; 1924 inode->i_mode = S_IFREG | S_IRUSR; 1925 inode->i_fop = &proc_fdinfo_file_operations; 1926 dentry->d_op = &tid_fd_dentry_operations; 1927 d_add(dentry, inode); 1928 /* Close the race of the process dying before we return the dentry */ 1929 if (tid_fd_revalidate(dentry, NULL)) 1930 error = NULL; 1931 1932 out: 1933 return error; 1934 } 1935 1936 static struct dentry *proc_lookupfdinfo(struct inode *dir, 1937 struct dentry *dentry, 1938 struct nameidata *nd) 1939 { 1940 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 1941 } 1942 1943 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 1944 { 1945 return proc_readfd_common(filp, dirent, filldir, 1946 proc_fdinfo_instantiate); 1947 } 1948 1949 static const struct file_operations proc_fdinfo_operations = { 1950 .read = generic_read_dir, 1951 .readdir = proc_readfdinfo, 1952 }; 1953 1954 /* 1955 * proc directories can do almost nothing.. 1956 */ 1957 static const struct inode_operations proc_fdinfo_inode_operations = { 1958 .lookup = proc_lookupfdinfo, 1959 .setattr = proc_setattr, 1960 }; 1961 1962 1963 static struct dentry *proc_pident_instantiate(struct inode *dir, 1964 struct dentry *dentry, struct task_struct *task, const void *ptr) 1965 { 1966 const struct pid_entry *p = ptr; 1967 struct inode *inode; 1968 struct proc_inode *ei; 1969 struct dentry *error = ERR_PTR(-ENOENT); 1970 1971 inode = proc_pid_make_inode(dir->i_sb, task); 1972 if (!inode) 1973 goto out; 1974 1975 ei = PROC_I(inode); 1976 inode->i_mode = p->mode; 1977 if (S_ISDIR(inode->i_mode)) 1978 inode->i_nlink = 2; /* Use getattr to fix if necessary */ 1979 if (p->iop) 1980 inode->i_op = p->iop; 1981 if (p->fop) 1982 inode->i_fop = p->fop; 1983 ei->op = p->op; 1984 dentry->d_op = &pid_dentry_operations; 1985 d_add(dentry, inode); 1986 /* Close the race of the process dying before we return the dentry */ 1987 if (pid_revalidate(dentry, NULL)) 1988 error = NULL; 1989 out: 1990 return error; 1991 } 1992 1993 static struct dentry *proc_pident_lookup(struct inode *dir, 1994 struct dentry *dentry, 1995 const struct pid_entry *ents, 1996 unsigned int nents) 1997 { 1998 struct dentry *error; 1999 struct task_struct *task = get_proc_task(dir); 2000 const struct pid_entry *p, *last; 2001 2002 error = ERR_PTR(-ENOENT); 2003 2004 if (!task) 2005 goto out_no_task; 2006 2007 /* 2008 * Yes, it does not scale. And it should not. Don't add 2009 * new entries into /proc/<tgid>/ without very good reasons. 2010 */ 2011 last = &ents[nents - 1]; 2012 for (p = ents; p <= last; p++) { 2013 if (p->len != dentry->d_name.len) 2014 continue; 2015 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2016 break; 2017 } 2018 if (p > last) 2019 goto out; 2020 2021 error = proc_pident_instantiate(dir, dentry, task, p); 2022 out: 2023 put_task_struct(task); 2024 out_no_task: 2025 return error; 2026 } 2027 2028 static int proc_pident_fill_cache(struct file *filp, void *dirent, 2029 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2030 { 2031 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2032 proc_pident_instantiate, task, p); 2033 } 2034 2035 static int proc_pident_readdir(struct file *filp, 2036 void *dirent, filldir_t filldir, 2037 const struct pid_entry *ents, unsigned int nents) 2038 { 2039 int i; 2040 struct dentry *dentry = filp->f_path.dentry; 2041 struct inode *inode = dentry->d_inode; 2042 struct task_struct *task = get_proc_task(inode); 2043 const struct pid_entry *p, *last; 2044 ino_t ino; 2045 int ret; 2046 2047 ret = -ENOENT; 2048 if (!task) 2049 goto out_no_task; 2050 2051 ret = 0; 2052 i = filp->f_pos; 2053 switch (i) { 2054 case 0: 2055 ino = inode->i_ino; 2056 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 2057 goto out; 2058 i++; 2059 filp->f_pos++; 2060 /* fall through */ 2061 case 1: 2062 ino = parent_ino(dentry); 2063 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 2064 goto out; 2065 i++; 2066 filp->f_pos++; 2067 /* fall through */ 2068 default: 2069 i -= 2; 2070 if (i >= nents) { 2071 ret = 1; 2072 goto out; 2073 } 2074 p = ents + i; 2075 last = &ents[nents - 1]; 2076 while (p <= last) { 2077 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2078 goto out; 2079 filp->f_pos++; 2080 p++; 2081 } 2082 } 2083 2084 ret = 1; 2085 out: 2086 put_task_struct(task); 2087 out_no_task: 2088 return ret; 2089 } 2090 2091 #ifdef CONFIG_SECURITY 2092 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2093 size_t count, loff_t *ppos) 2094 { 2095 struct inode * inode = file->f_path.dentry->d_inode; 2096 char *p = NULL; 2097 ssize_t length; 2098 struct task_struct *task = get_proc_task(inode); 2099 2100 if (!task) 2101 return -ESRCH; 2102 2103 length = security_getprocattr(task, 2104 (char*)file->f_path.dentry->d_name.name, 2105 &p); 2106 put_task_struct(task); 2107 if (length > 0) 2108 length = simple_read_from_buffer(buf, count, ppos, p, length); 2109 kfree(p); 2110 return length; 2111 } 2112 2113 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2114 size_t count, loff_t *ppos) 2115 { 2116 struct inode * inode = file->f_path.dentry->d_inode; 2117 char *page; 2118 ssize_t length; 2119 struct task_struct *task = get_proc_task(inode); 2120 2121 length = -ESRCH; 2122 if (!task) 2123 goto out_no_task; 2124 if (count > PAGE_SIZE) 2125 count = PAGE_SIZE; 2126 2127 /* No partial writes. */ 2128 length = -EINVAL; 2129 if (*ppos != 0) 2130 goto out; 2131 2132 length = -ENOMEM; 2133 page = (char*)__get_free_page(GFP_TEMPORARY); 2134 if (!page) 2135 goto out; 2136 2137 length = -EFAULT; 2138 if (copy_from_user(page, buf, count)) 2139 goto out_free; 2140 2141 /* Guard against adverse ptrace interaction */ 2142 length = mutex_lock_interruptible(&task->cred_guard_mutex); 2143 if (length < 0) 2144 goto out_free; 2145 2146 length = security_setprocattr(task, 2147 (char*)file->f_path.dentry->d_name.name, 2148 (void*)page, count); 2149 mutex_unlock(&task->cred_guard_mutex); 2150 out_free: 2151 free_page((unsigned long) page); 2152 out: 2153 put_task_struct(task); 2154 out_no_task: 2155 return length; 2156 } 2157 2158 static const struct file_operations proc_pid_attr_operations = { 2159 .read = proc_pid_attr_read, 2160 .write = proc_pid_attr_write, 2161 }; 2162 2163 static const struct pid_entry attr_dir_stuff[] = { 2164 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2165 REG("prev", S_IRUGO, proc_pid_attr_operations), 2166 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2167 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2168 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2169 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2170 }; 2171 2172 static int proc_attr_dir_readdir(struct file * filp, 2173 void * dirent, filldir_t filldir) 2174 { 2175 return proc_pident_readdir(filp,dirent,filldir, 2176 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2177 } 2178 2179 static const struct file_operations proc_attr_dir_operations = { 2180 .read = generic_read_dir, 2181 .readdir = proc_attr_dir_readdir, 2182 }; 2183 2184 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2185 struct dentry *dentry, struct nameidata *nd) 2186 { 2187 return proc_pident_lookup(dir, dentry, 2188 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2189 } 2190 2191 static const struct inode_operations proc_attr_dir_inode_operations = { 2192 .lookup = proc_attr_dir_lookup, 2193 .getattr = pid_getattr, 2194 .setattr = proc_setattr, 2195 }; 2196 2197 #endif 2198 2199 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2200 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2201 size_t count, loff_t *ppos) 2202 { 2203 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2204 struct mm_struct *mm; 2205 char buffer[PROC_NUMBUF]; 2206 size_t len; 2207 int ret; 2208 2209 if (!task) 2210 return -ESRCH; 2211 2212 ret = 0; 2213 mm = get_task_mm(task); 2214 if (mm) { 2215 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2216 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2217 MMF_DUMP_FILTER_SHIFT)); 2218 mmput(mm); 2219 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2220 } 2221 2222 put_task_struct(task); 2223 2224 return ret; 2225 } 2226 2227 static ssize_t proc_coredump_filter_write(struct file *file, 2228 const char __user *buf, 2229 size_t count, 2230 loff_t *ppos) 2231 { 2232 struct task_struct *task; 2233 struct mm_struct *mm; 2234 char buffer[PROC_NUMBUF], *end; 2235 unsigned int val; 2236 int ret; 2237 int i; 2238 unsigned long mask; 2239 2240 ret = -EFAULT; 2241 memset(buffer, 0, sizeof(buffer)); 2242 if (count > sizeof(buffer) - 1) 2243 count = sizeof(buffer) - 1; 2244 if (copy_from_user(buffer, buf, count)) 2245 goto out_no_task; 2246 2247 ret = -EINVAL; 2248 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2249 if (*end == '\n') 2250 end++; 2251 if (end - buffer == 0) 2252 goto out_no_task; 2253 2254 ret = -ESRCH; 2255 task = get_proc_task(file->f_dentry->d_inode); 2256 if (!task) 2257 goto out_no_task; 2258 2259 ret = end - buffer; 2260 mm = get_task_mm(task); 2261 if (!mm) 2262 goto out_no_mm; 2263 2264 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2265 if (val & mask) 2266 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2267 else 2268 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2269 } 2270 2271 mmput(mm); 2272 out_no_mm: 2273 put_task_struct(task); 2274 out_no_task: 2275 return ret; 2276 } 2277 2278 static const struct file_operations proc_coredump_filter_operations = { 2279 .read = proc_coredump_filter_read, 2280 .write = proc_coredump_filter_write, 2281 }; 2282 #endif 2283 2284 /* 2285 * /proc/self: 2286 */ 2287 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2288 int buflen) 2289 { 2290 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2291 pid_t tgid = task_tgid_nr_ns(current, ns); 2292 char tmp[PROC_NUMBUF]; 2293 if (!tgid) 2294 return -ENOENT; 2295 sprintf(tmp, "%d", tgid); 2296 return vfs_readlink(dentry,buffer,buflen,tmp); 2297 } 2298 2299 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2300 { 2301 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2302 pid_t tgid = task_tgid_nr_ns(current, ns); 2303 char tmp[PROC_NUMBUF]; 2304 if (!tgid) 2305 return ERR_PTR(-ENOENT); 2306 sprintf(tmp, "%d", task_tgid_nr_ns(current, ns)); 2307 return ERR_PTR(vfs_follow_link(nd,tmp)); 2308 } 2309 2310 static const struct inode_operations proc_self_inode_operations = { 2311 .readlink = proc_self_readlink, 2312 .follow_link = proc_self_follow_link, 2313 }; 2314 2315 /* 2316 * proc base 2317 * 2318 * These are the directory entries in the root directory of /proc 2319 * that properly belong to the /proc filesystem, as they describe 2320 * describe something that is process related. 2321 */ 2322 static const struct pid_entry proc_base_stuff[] = { 2323 NOD("self", S_IFLNK|S_IRWXUGO, 2324 &proc_self_inode_operations, NULL, {}), 2325 }; 2326 2327 /* 2328 * Exceptional case: normally we are not allowed to unhash a busy 2329 * directory. In this case, however, we can do it - no aliasing problems 2330 * due to the way we treat inodes. 2331 */ 2332 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) 2333 { 2334 struct inode *inode = dentry->d_inode; 2335 struct task_struct *task = get_proc_task(inode); 2336 if (task) { 2337 put_task_struct(task); 2338 return 1; 2339 } 2340 d_drop(dentry); 2341 return 0; 2342 } 2343 2344 static const struct dentry_operations proc_base_dentry_operations = 2345 { 2346 .d_revalidate = proc_base_revalidate, 2347 .d_delete = pid_delete_dentry, 2348 }; 2349 2350 static struct dentry *proc_base_instantiate(struct inode *dir, 2351 struct dentry *dentry, struct task_struct *task, const void *ptr) 2352 { 2353 const struct pid_entry *p = ptr; 2354 struct inode *inode; 2355 struct proc_inode *ei; 2356 struct dentry *error = ERR_PTR(-EINVAL); 2357 2358 /* Allocate the inode */ 2359 error = ERR_PTR(-ENOMEM); 2360 inode = new_inode(dir->i_sb); 2361 if (!inode) 2362 goto out; 2363 2364 /* Initialize the inode */ 2365 ei = PROC_I(inode); 2366 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2367 2368 /* 2369 * grab the reference to the task. 2370 */ 2371 ei->pid = get_task_pid(task, PIDTYPE_PID); 2372 if (!ei->pid) 2373 goto out_iput; 2374 2375 inode->i_mode = p->mode; 2376 if (S_ISDIR(inode->i_mode)) 2377 inode->i_nlink = 2; 2378 if (S_ISLNK(inode->i_mode)) 2379 inode->i_size = 64; 2380 if (p->iop) 2381 inode->i_op = p->iop; 2382 if (p->fop) 2383 inode->i_fop = p->fop; 2384 ei->op = p->op; 2385 dentry->d_op = &proc_base_dentry_operations; 2386 d_add(dentry, inode); 2387 error = NULL; 2388 out: 2389 return error; 2390 out_iput: 2391 iput(inode); 2392 goto out; 2393 } 2394 2395 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2396 { 2397 struct dentry *error; 2398 struct task_struct *task = get_proc_task(dir); 2399 const struct pid_entry *p, *last; 2400 2401 error = ERR_PTR(-ENOENT); 2402 2403 if (!task) 2404 goto out_no_task; 2405 2406 /* Lookup the directory entry */ 2407 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2408 for (p = proc_base_stuff; p <= last; p++) { 2409 if (p->len != dentry->d_name.len) 2410 continue; 2411 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2412 break; 2413 } 2414 if (p > last) 2415 goto out; 2416 2417 error = proc_base_instantiate(dir, dentry, task, p); 2418 2419 out: 2420 put_task_struct(task); 2421 out_no_task: 2422 return error; 2423 } 2424 2425 static int proc_base_fill_cache(struct file *filp, void *dirent, 2426 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2427 { 2428 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2429 proc_base_instantiate, task, p); 2430 } 2431 2432 #ifdef CONFIG_TASK_IO_ACCOUNTING 2433 static int do_io_accounting(struct task_struct *task, char *buffer, int whole) 2434 { 2435 struct task_io_accounting acct = task->ioac; 2436 unsigned long flags; 2437 2438 if (whole && lock_task_sighand(task, &flags)) { 2439 struct task_struct *t = task; 2440 2441 task_io_accounting_add(&acct, &task->signal->ioac); 2442 while_each_thread(task, t) 2443 task_io_accounting_add(&acct, &t->ioac); 2444 2445 unlock_task_sighand(task, &flags); 2446 } 2447 return sprintf(buffer, 2448 "rchar: %llu\n" 2449 "wchar: %llu\n" 2450 "syscr: %llu\n" 2451 "syscw: %llu\n" 2452 "read_bytes: %llu\n" 2453 "write_bytes: %llu\n" 2454 "cancelled_write_bytes: %llu\n", 2455 (unsigned long long)acct.rchar, 2456 (unsigned long long)acct.wchar, 2457 (unsigned long long)acct.syscr, 2458 (unsigned long long)acct.syscw, 2459 (unsigned long long)acct.read_bytes, 2460 (unsigned long long)acct.write_bytes, 2461 (unsigned long long)acct.cancelled_write_bytes); 2462 } 2463 2464 static int proc_tid_io_accounting(struct task_struct *task, char *buffer) 2465 { 2466 return do_io_accounting(task, buffer, 0); 2467 } 2468 2469 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer) 2470 { 2471 return do_io_accounting(task, buffer, 1); 2472 } 2473 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2474 2475 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2476 struct pid *pid, struct task_struct *task) 2477 { 2478 seq_printf(m, "%08x\n", task->personality); 2479 return 0; 2480 } 2481 2482 /* 2483 * Thread groups 2484 */ 2485 static const struct file_operations proc_task_operations; 2486 static const struct inode_operations proc_task_inode_operations; 2487 2488 static const struct pid_entry tgid_base_stuff[] = { 2489 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2490 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2491 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2492 #ifdef CONFIG_NET 2493 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2494 #endif 2495 REG("environ", S_IRUSR, proc_environ_operations), 2496 INF("auxv", S_IRUSR, proc_pid_auxv), 2497 ONE("status", S_IRUGO, proc_pid_status), 2498 ONE("personality", S_IRUSR, proc_pid_personality), 2499 INF("limits", S_IRUSR, proc_pid_limits), 2500 #ifdef CONFIG_SCHED_DEBUG 2501 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2502 #endif 2503 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2504 INF("syscall", S_IRUSR, proc_pid_syscall), 2505 #endif 2506 INF("cmdline", S_IRUGO, proc_pid_cmdline), 2507 ONE("stat", S_IRUGO, proc_tgid_stat), 2508 ONE("statm", S_IRUGO, proc_pid_statm), 2509 REG("maps", S_IRUGO, proc_maps_operations), 2510 #ifdef CONFIG_NUMA 2511 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 2512 #endif 2513 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2514 LNK("cwd", proc_cwd_link), 2515 LNK("root", proc_root_link), 2516 LNK("exe", proc_exe_link), 2517 REG("mounts", S_IRUGO, proc_mounts_operations), 2518 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2519 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2520 #ifdef CONFIG_PROC_PAGE_MONITOR 2521 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2522 REG("smaps", S_IRUGO, proc_smaps_operations), 2523 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2524 #endif 2525 #ifdef CONFIG_SECURITY 2526 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2527 #endif 2528 #ifdef CONFIG_KALLSYMS 2529 INF("wchan", S_IRUGO, proc_pid_wchan), 2530 #endif 2531 #ifdef CONFIG_STACKTRACE 2532 ONE("stack", S_IRUSR, proc_pid_stack), 2533 #endif 2534 #ifdef CONFIG_SCHEDSTATS 2535 INF("schedstat", S_IRUGO, proc_pid_schedstat), 2536 #endif 2537 #ifdef CONFIG_LATENCYTOP 2538 REG("latency", S_IRUGO, proc_lstats_operations), 2539 #endif 2540 #ifdef CONFIG_PROC_PID_CPUSET 2541 REG("cpuset", S_IRUGO, proc_cpuset_operations), 2542 #endif 2543 #ifdef CONFIG_CGROUPS 2544 REG("cgroup", S_IRUGO, proc_cgroup_operations), 2545 #endif 2546 INF("oom_score", S_IRUGO, proc_oom_score), 2547 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 2548 #ifdef CONFIG_AUDITSYSCALL 2549 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2550 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2551 #endif 2552 #ifdef CONFIG_FAULT_INJECTION 2553 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2554 #endif 2555 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2556 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2557 #endif 2558 #ifdef CONFIG_TASK_IO_ACCOUNTING 2559 INF("io", S_IRUGO, proc_tgid_io_accounting), 2560 #endif 2561 }; 2562 2563 static int proc_tgid_base_readdir(struct file * filp, 2564 void * dirent, filldir_t filldir) 2565 { 2566 return proc_pident_readdir(filp,dirent,filldir, 2567 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2568 } 2569 2570 static const struct file_operations proc_tgid_base_operations = { 2571 .read = generic_read_dir, 2572 .readdir = proc_tgid_base_readdir, 2573 }; 2574 2575 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2576 return proc_pident_lookup(dir, dentry, 2577 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2578 } 2579 2580 static const struct inode_operations proc_tgid_base_inode_operations = { 2581 .lookup = proc_tgid_base_lookup, 2582 .getattr = pid_getattr, 2583 .setattr = proc_setattr, 2584 }; 2585 2586 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2587 { 2588 struct dentry *dentry, *leader, *dir; 2589 char buf[PROC_NUMBUF]; 2590 struct qstr name; 2591 2592 name.name = buf; 2593 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2594 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2595 if (dentry) { 2596 if (!(current->flags & PF_EXITING)) 2597 shrink_dcache_parent(dentry); 2598 d_drop(dentry); 2599 dput(dentry); 2600 } 2601 2602 if (tgid == 0) 2603 goto out; 2604 2605 name.name = buf; 2606 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2607 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2608 if (!leader) 2609 goto out; 2610 2611 name.name = "task"; 2612 name.len = strlen(name.name); 2613 dir = d_hash_and_lookup(leader, &name); 2614 if (!dir) 2615 goto out_put_leader; 2616 2617 name.name = buf; 2618 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2619 dentry = d_hash_and_lookup(dir, &name); 2620 if (dentry) { 2621 shrink_dcache_parent(dentry); 2622 d_drop(dentry); 2623 dput(dentry); 2624 } 2625 2626 dput(dir); 2627 out_put_leader: 2628 dput(leader); 2629 out: 2630 return; 2631 } 2632 2633 /** 2634 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2635 * @task: task that should be flushed. 2636 * 2637 * When flushing dentries from proc, one needs to flush them from global 2638 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2639 * in. This call is supposed to do all of this job. 2640 * 2641 * Looks in the dcache for 2642 * /proc/@pid 2643 * /proc/@tgid/task/@pid 2644 * if either directory is present flushes it and all of it'ts children 2645 * from the dcache. 2646 * 2647 * It is safe and reasonable to cache /proc entries for a task until 2648 * that task exits. After that they just clog up the dcache with 2649 * useless entries, possibly causing useful dcache entries to be 2650 * flushed instead. This routine is proved to flush those useless 2651 * dcache entries at process exit time. 2652 * 2653 * NOTE: This routine is just an optimization so it does not guarantee 2654 * that no dcache entries will exist at process exit time it 2655 * just makes it very unlikely that any will persist. 2656 */ 2657 2658 void proc_flush_task(struct task_struct *task) 2659 { 2660 int i; 2661 struct pid *pid, *tgid = NULL; 2662 struct upid *upid; 2663 2664 pid = task_pid(task); 2665 if (thread_group_leader(task)) 2666 tgid = task_tgid(task); 2667 2668 for (i = 0; i <= pid->level; i++) { 2669 upid = &pid->numbers[i]; 2670 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 2671 tgid ? tgid->numbers[i].nr : 0); 2672 } 2673 2674 upid = &pid->numbers[pid->level]; 2675 if (upid->nr == 1) 2676 pid_ns_release_proc(upid->ns); 2677 } 2678 2679 static struct dentry *proc_pid_instantiate(struct inode *dir, 2680 struct dentry * dentry, 2681 struct task_struct *task, const void *ptr) 2682 { 2683 struct dentry *error = ERR_PTR(-ENOENT); 2684 struct inode *inode; 2685 2686 inode = proc_pid_make_inode(dir->i_sb, task); 2687 if (!inode) 2688 goto out; 2689 2690 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2691 inode->i_op = &proc_tgid_base_inode_operations; 2692 inode->i_fop = &proc_tgid_base_operations; 2693 inode->i_flags|=S_IMMUTABLE; 2694 2695 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff, 2696 ARRAY_SIZE(tgid_base_stuff)); 2697 2698 dentry->d_op = &pid_dentry_operations; 2699 2700 d_add(dentry, inode); 2701 /* Close the race of the process dying before we return the dentry */ 2702 if (pid_revalidate(dentry, NULL)) 2703 error = NULL; 2704 out: 2705 return error; 2706 } 2707 2708 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2709 { 2710 struct dentry *result = ERR_PTR(-ENOENT); 2711 struct task_struct *task; 2712 unsigned tgid; 2713 struct pid_namespace *ns; 2714 2715 result = proc_base_lookup(dir, dentry); 2716 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 2717 goto out; 2718 2719 tgid = name_to_int(dentry); 2720 if (tgid == ~0U) 2721 goto out; 2722 2723 ns = dentry->d_sb->s_fs_info; 2724 rcu_read_lock(); 2725 task = find_task_by_pid_ns(tgid, ns); 2726 if (task) 2727 get_task_struct(task); 2728 rcu_read_unlock(); 2729 if (!task) 2730 goto out; 2731 2732 result = proc_pid_instantiate(dir, dentry, task, NULL); 2733 put_task_struct(task); 2734 out: 2735 return result; 2736 } 2737 2738 /* 2739 * Find the first task with tgid >= tgid 2740 * 2741 */ 2742 struct tgid_iter { 2743 unsigned int tgid; 2744 struct task_struct *task; 2745 }; 2746 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 2747 { 2748 struct pid *pid; 2749 2750 if (iter.task) 2751 put_task_struct(iter.task); 2752 rcu_read_lock(); 2753 retry: 2754 iter.task = NULL; 2755 pid = find_ge_pid(iter.tgid, ns); 2756 if (pid) { 2757 iter.tgid = pid_nr_ns(pid, ns); 2758 iter.task = pid_task(pid, PIDTYPE_PID); 2759 /* What we to know is if the pid we have find is the 2760 * pid of a thread_group_leader. Testing for task 2761 * being a thread_group_leader is the obvious thing 2762 * todo but there is a window when it fails, due to 2763 * the pid transfer logic in de_thread. 2764 * 2765 * So we perform the straight forward test of seeing 2766 * if the pid we have found is the pid of a thread 2767 * group leader, and don't worry if the task we have 2768 * found doesn't happen to be a thread group leader. 2769 * As we don't care in the case of readdir. 2770 */ 2771 if (!iter.task || !has_group_leader_pid(iter.task)) { 2772 iter.tgid += 1; 2773 goto retry; 2774 } 2775 get_task_struct(iter.task); 2776 } 2777 rcu_read_unlock(); 2778 return iter; 2779 } 2780 2781 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 2782 2783 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2784 struct tgid_iter iter) 2785 { 2786 char name[PROC_NUMBUF]; 2787 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 2788 return proc_fill_cache(filp, dirent, filldir, name, len, 2789 proc_pid_instantiate, iter.task, NULL); 2790 } 2791 2792 /* for the /proc/ directory itself, after non-process stuff has been done */ 2793 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 2794 { 2795 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; 2796 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode); 2797 struct tgid_iter iter; 2798 struct pid_namespace *ns; 2799 2800 if (!reaper) 2801 goto out_no_task; 2802 2803 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 2804 const struct pid_entry *p = &proc_base_stuff[nr]; 2805 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 2806 goto out; 2807 } 2808 2809 ns = filp->f_dentry->d_sb->s_fs_info; 2810 iter.task = NULL; 2811 iter.tgid = filp->f_pos - TGID_OFFSET; 2812 for (iter = next_tgid(ns, iter); 2813 iter.task; 2814 iter.tgid += 1, iter = next_tgid(ns, iter)) { 2815 filp->f_pos = iter.tgid + TGID_OFFSET; 2816 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) { 2817 put_task_struct(iter.task); 2818 goto out; 2819 } 2820 } 2821 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 2822 out: 2823 put_task_struct(reaper); 2824 out_no_task: 2825 return 0; 2826 } 2827 2828 /* 2829 * Tasks 2830 */ 2831 static const struct pid_entry tid_base_stuff[] = { 2832 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2833 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fd_operations), 2834 REG("environ", S_IRUSR, proc_environ_operations), 2835 INF("auxv", S_IRUSR, proc_pid_auxv), 2836 ONE("status", S_IRUGO, proc_pid_status), 2837 ONE("personality", S_IRUSR, proc_pid_personality), 2838 INF("limits", S_IRUSR, proc_pid_limits), 2839 #ifdef CONFIG_SCHED_DEBUG 2840 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2841 #endif 2842 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2843 INF("syscall", S_IRUSR, proc_pid_syscall), 2844 #endif 2845 INF("cmdline", S_IRUGO, proc_pid_cmdline), 2846 ONE("stat", S_IRUGO, proc_tid_stat), 2847 ONE("statm", S_IRUGO, proc_pid_statm), 2848 REG("maps", S_IRUGO, proc_maps_operations), 2849 #ifdef CONFIG_NUMA 2850 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 2851 #endif 2852 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2853 LNK("cwd", proc_cwd_link), 2854 LNK("root", proc_root_link), 2855 LNK("exe", proc_exe_link), 2856 REG("mounts", S_IRUGO, proc_mounts_operations), 2857 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2858 #ifdef CONFIG_PROC_PAGE_MONITOR 2859 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2860 REG("smaps", S_IRUGO, proc_smaps_operations), 2861 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2862 #endif 2863 #ifdef CONFIG_SECURITY 2864 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2865 #endif 2866 #ifdef CONFIG_KALLSYMS 2867 INF("wchan", S_IRUGO, proc_pid_wchan), 2868 #endif 2869 #ifdef CONFIG_STACKTRACE 2870 ONE("stack", S_IRUSR, proc_pid_stack), 2871 #endif 2872 #ifdef CONFIG_SCHEDSTATS 2873 INF("schedstat", S_IRUGO, proc_pid_schedstat), 2874 #endif 2875 #ifdef CONFIG_LATENCYTOP 2876 REG("latency", S_IRUGO, proc_lstats_operations), 2877 #endif 2878 #ifdef CONFIG_PROC_PID_CPUSET 2879 REG("cpuset", S_IRUGO, proc_cpuset_operations), 2880 #endif 2881 #ifdef CONFIG_CGROUPS 2882 REG("cgroup", S_IRUGO, proc_cgroup_operations), 2883 #endif 2884 INF("oom_score", S_IRUGO, proc_oom_score), 2885 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 2886 #ifdef CONFIG_AUDITSYSCALL 2887 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2888 REG("sessionid", S_IRUSR, proc_sessionid_operations), 2889 #endif 2890 #ifdef CONFIG_FAULT_INJECTION 2891 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2892 #endif 2893 #ifdef CONFIG_TASK_IO_ACCOUNTING 2894 INF("io", S_IRUGO, proc_tid_io_accounting), 2895 #endif 2896 }; 2897 2898 static int proc_tid_base_readdir(struct file * filp, 2899 void * dirent, filldir_t filldir) 2900 { 2901 return proc_pident_readdir(filp,dirent,filldir, 2902 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 2903 } 2904 2905 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2906 return proc_pident_lookup(dir, dentry, 2907 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 2908 } 2909 2910 static const struct file_operations proc_tid_base_operations = { 2911 .read = generic_read_dir, 2912 .readdir = proc_tid_base_readdir, 2913 }; 2914 2915 static const struct inode_operations proc_tid_base_inode_operations = { 2916 .lookup = proc_tid_base_lookup, 2917 .getattr = pid_getattr, 2918 .setattr = proc_setattr, 2919 }; 2920 2921 static struct dentry *proc_task_instantiate(struct inode *dir, 2922 struct dentry *dentry, struct task_struct *task, const void *ptr) 2923 { 2924 struct dentry *error = ERR_PTR(-ENOENT); 2925 struct inode *inode; 2926 inode = proc_pid_make_inode(dir->i_sb, task); 2927 2928 if (!inode) 2929 goto out; 2930 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2931 inode->i_op = &proc_tid_base_inode_operations; 2932 inode->i_fop = &proc_tid_base_operations; 2933 inode->i_flags|=S_IMMUTABLE; 2934 2935 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff, 2936 ARRAY_SIZE(tid_base_stuff)); 2937 2938 dentry->d_op = &pid_dentry_operations; 2939 2940 d_add(dentry, inode); 2941 /* Close the race of the process dying before we return the dentry */ 2942 if (pid_revalidate(dentry, NULL)) 2943 error = NULL; 2944 out: 2945 return error; 2946 } 2947 2948 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2949 { 2950 struct dentry *result = ERR_PTR(-ENOENT); 2951 struct task_struct *task; 2952 struct task_struct *leader = get_proc_task(dir); 2953 unsigned tid; 2954 struct pid_namespace *ns; 2955 2956 if (!leader) 2957 goto out_no_task; 2958 2959 tid = name_to_int(dentry); 2960 if (tid == ~0U) 2961 goto out; 2962 2963 ns = dentry->d_sb->s_fs_info; 2964 rcu_read_lock(); 2965 task = find_task_by_pid_ns(tid, ns); 2966 if (task) 2967 get_task_struct(task); 2968 rcu_read_unlock(); 2969 if (!task) 2970 goto out; 2971 if (!same_thread_group(leader, task)) 2972 goto out_drop_task; 2973 2974 result = proc_task_instantiate(dir, dentry, task, NULL); 2975 out_drop_task: 2976 put_task_struct(task); 2977 out: 2978 put_task_struct(leader); 2979 out_no_task: 2980 return result; 2981 } 2982 2983 /* 2984 * Find the first tid of a thread group to return to user space. 2985 * 2986 * Usually this is just the thread group leader, but if the users 2987 * buffer was too small or there was a seek into the middle of the 2988 * directory we have more work todo. 2989 * 2990 * In the case of a short read we start with find_task_by_pid. 2991 * 2992 * In the case of a seek we start with the leader and walk nr 2993 * threads past it. 2994 */ 2995 static struct task_struct *first_tid(struct task_struct *leader, 2996 int tid, int nr, struct pid_namespace *ns) 2997 { 2998 struct task_struct *pos; 2999 3000 rcu_read_lock(); 3001 /* Attempt to start with the pid of a thread */ 3002 if (tid && (nr > 0)) { 3003 pos = find_task_by_pid_ns(tid, ns); 3004 if (pos && (pos->group_leader == leader)) 3005 goto found; 3006 } 3007 3008 /* If nr exceeds the number of threads there is nothing todo */ 3009 pos = NULL; 3010 if (nr && nr >= get_nr_threads(leader)) 3011 goto out; 3012 3013 /* If we haven't found our starting place yet start 3014 * with the leader and walk nr threads forward. 3015 */ 3016 for (pos = leader; nr > 0; --nr) { 3017 pos = next_thread(pos); 3018 if (pos == leader) { 3019 pos = NULL; 3020 goto out; 3021 } 3022 } 3023 found: 3024 get_task_struct(pos); 3025 out: 3026 rcu_read_unlock(); 3027 return pos; 3028 } 3029 3030 /* 3031 * Find the next thread in the thread list. 3032 * Return NULL if there is an error or no next thread. 3033 * 3034 * The reference to the input task_struct is released. 3035 */ 3036 static struct task_struct *next_tid(struct task_struct *start) 3037 { 3038 struct task_struct *pos = NULL; 3039 rcu_read_lock(); 3040 if (pid_alive(start)) { 3041 pos = next_thread(start); 3042 if (thread_group_leader(pos)) 3043 pos = NULL; 3044 else 3045 get_task_struct(pos); 3046 } 3047 rcu_read_unlock(); 3048 put_task_struct(start); 3049 return pos; 3050 } 3051 3052 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3053 struct task_struct *task, int tid) 3054 { 3055 char name[PROC_NUMBUF]; 3056 int len = snprintf(name, sizeof(name), "%d", tid); 3057 return proc_fill_cache(filp, dirent, filldir, name, len, 3058 proc_task_instantiate, task, NULL); 3059 } 3060 3061 /* for the /proc/TGID/task/ directories */ 3062 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 3063 { 3064 struct dentry *dentry = filp->f_path.dentry; 3065 struct inode *inode = dentry->d_inode; 3066 struct task_struct *leader = NULL; 3067 struct task_struct *task; 3068 int retval = -ENOENT; 3069 ino_t ino; 3070 int tid; 3071 struct pid_namespace *ns; 3072 3073 task = get_proc_task(inode); 3074 if (!task) 3075 goto out_no_task; 3076 rcu_read_lock(); 3077 if (pid_alive(task)) { 3078 leader = task->group_leader; 3079 get_task_struct(leader); 3080 } 3081 rcu_read_unlock(); 3082 put_task_struct(task); 3083 if (!leader) 3084 goto out_no_task; 3085 retval = 0; 3086 3087 switch ((unsigned long)filp->f_pos) { 3088 case 0: 3089 ino = inode->i_ino; 3090 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0) 3091 goto out; 3092 filp->f_pos++; 3093 /* fall through */ 3094 case 1: 3095 ino = parent_ino(dentry); 3096 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0) 3097 goto out; 3098 filp->f_pos++; 3099 /* fall through */ 3100 } 3101 3102 /* f_version caches the tgid value that the last readdir call couldn't 3103 * return. lseek aka telldir automagically resets f_version to 0. 3104 */ 3105 ns = filp->f_dentry->d_sb->s_fs_info; 3106 tid = (int)filp->f_version; 3107 filp->f_version = 0; 3108 for (task = first_tid(leader, tid, filp->f_pos - 2, ns); 3109 task; 3110 task = next_tid(task), filp->f_pos++) { 3111 tid = task_pid_nr_ns(task, ns); 3112 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 3113 /* returning this tgid failed, save it as the first 3114 * pid for the next readir call */ 3115 filp->f_version = (u64)tid; 3116 put_task_struct(task); 3117 break; 3118 } 3119 } 3120 out: 3121 put_task_struct(leader); 3122 out_no_task: 3123 return retval; 3124 } 3125 3126 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3127 { 3128 struct inode *inode = dentry->d_inode; 3129 struct task_struct *p = get_proc_task(inode); 3130 generic_fillattr(inode, stat); 3131 3132 if (p) { 3133 stat->nlink += get_nr_threads(p); 3134 put_task_struct(p); 3135 } 3136 3137 return 0; 3138 } 3139 3140 static const struct inode_operations proc_task_inode_operations = { 3141 .lookup = proc_task_lookup, 3142 .getattr = proc_task_getattr, 3143 .setattr = proc_setattr, 3144 }; 3145 3146 static const struct file_operations proc_task_operations = { 3147 .read = generic_read_dir, 3148 .readdir = proc_task_readdir, 3149 }; 3150