1 /* 2 * linux/fs/proc/base.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 * 6 * proc base directory handling functions 7 * 8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part. 9 * Instead of using magical inumbers to determine the kind of object 10 * we allocate and fill in-core inodes upon lookup. They don't even 11 * go into icache. We cache the reference to task_struct upon lookup too. 12 * Eventually it should become a filesystem in its own. We don't use the 13 * rest of procfs anymore. 14 * 15 * 16 * Changelog: 17 * 17-Jan-2005 18 * Allan Bezerra 19 * Bruna Moreira <bruna.moreira@indt.org.br> 20 * Edjard Mota <edjard.mota@indt.org.br> 21 * Ilias Biris <ilias.biris@indt.org.br> 22 * Mauricio Lin <mauricio.lin@indt.org.br> 23 * 24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 25 * 26 * A new process specific entry (smaps) included in /proc. It shows the 27 * size of rss for each memory area. The maps entry lacks information 28 * about physical memory size (rss) for each mapped file, i.e., 29 * rss information for executables and library files. 30 * This additional information is useful for any tools that need to know 31 * about physical memory consumption for a process specific library. 32 * 33 * Changelog: 34 * 21-Feb-2005 35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 36 * Pud inclusion in the page table walking. 37 * 38 * ChangeLog: 39 * 10-Mar-2005 40 * 10LE Instituto Nokia de Tecnologia - INdT: 41 * A better way to walks through the page table as suggested by Hugh Dickins. 42 * 43 * Simo Piiroinen <simo.piiroinen@nokia.com>: 44 * Smaps information related to shared, private, clean and dirty pages. 45 * 46 * Paul Mundt <paul.mundt@nokia.com>: 47 * Overall revision about smaps. 48 */ 49 50 #include <asm/uaccess.h> 51 52 #include <linux/errno.h> 53 #include <linux/time.h> 54 #include <linux/proc_fs.h> 55 #include <linux/stat.h> 56 #include <linux/task_io_accounting_ops.h> 57 #include <linux/init.h> 58 #include <linux/capability.h> 59 #include <linux/file.h> 60 #include <linux/fdtable.h> 61 #include <linux/string.h> 62 #include <linux/seq_file.h> 63 #include <linux/namei.h> 64 #include <linux/mnt_namespace.h> 65 #include <linux/mm.h> 66 #include <linux/rcupdate.h> 67 #include <linux/kallsyms.h> 68 #include <linux/stacktrace.h> 69 #include <linux/resource.h> 70 #include <linux/module.h> 71 #include <linux/mount.h> 72 #include <linux/security.h> 73 #include <linux/ptrace.h> 74 #include <linux/tracehook.h> 75 #include <linux/cgroup.h> 76 #include <linux/cpuset.h> 77 #include <linux/audit.h> 78 #include <linux/poll.h> 79 #include <linux/nsproxy.h> 80 #include <linux/oom.h> 81 #include <linux/elf.h> 82 #include <linux/pid_namespace.h> 83 #include <linux/fs_struct.h> 84 #include "internal.h" 85 86 /* NOTE: 87 * Implementing inode permission operations in /proc is almost 88 * certainly an error. Permission checks need to happen during 89 * each system call not at open time. The reason is that most of 90 * what we wish to check for permissions in /proc varies at runtime. 91 * 92 * The classic example of a problem is opening file descriptors 93 * in /proc for a task before it execs a suid executable. 94 */ 95 96 struct pid_entry { 97 char *name; 98 int len; 99 mode_t mode; 100 const struct inode_operations *iop; 101 const struct file_operations *fop; 102 union proc_op op; 103 }; 104 105 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 106 .name = (NAME), \ 107 .len = sizeof(NAME) - 1, \ 108 .mode = MODE, \ 109 .iop = IOP, \ 110 .fop = FOP, \ 111 .op = OP, \ 112 } 113 114 #define DIR(NAME, MODE, iops, fops) \ 115 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} ) 116 #define LNK(NAME, get_link) \ 117 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 118 &proc_pid_link_inode_operations, NULL, \ 119 { .proc_get_link = get_link } ) 120 #define REG(NAME, MODE, fops) \ 121 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {}) 122 #define INF(NAME, MODE, read) \ 123 NOD(NAME, (S_IFREG|(MODE)), \ 124 NULL, &proc_info_file_operations, \ 125 { .proc_read = read } ) 126 #define ONE(NAME, MODE, show) \ 127 NOD(NAME, (S_IFREG|(MODE)), \ 128 NULL, &proc_single_file_operations, \ 129 { .proc_show = show } ) 130 131 /* 132 * Count the number of hardlinks for the pid_entry table, excluding the . 133 * and .. links. 134 */ 135 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries, 136 unsigned int n) 137 { 138 unsigned int i; 139 unsigned int count; 140 141 count = 0; 142 for (i = 0; i < n; ++i) { 143 if (S_ISDIR(entries[i].mode)) 144 ++count; 145 } 146 147 return count; 148 } 149 150 static int get_fs_path(struct task_struct *task, struct path *path, bool root) 151 { 152 struct fs_struct *fs; 153 int result = -ENOENT; 154 155 task_lock(task); 156 fs = task->fs; 157 if (fs) { 158 read_lock(&fs->lock); 159 *path = root ? fs->root : fs->pwd; 160 path_get(path); 161 read_unlock(&fs->lock); 162 result = 0; 163 } 164 task_unlock(task); 165 return result; 166 } 167 168 static int get_nr_threads(struct task_struct *tsk) 169 { 170 unsigned long flags; 171 int count = 0; 172 173 if (lock_task_sighand(tsk, &flags)) { 174 count = atomic_read(&tsk->signal->count); 175 unlock_task_sighand(tsk, &flags); 176 } 177 return count; 178 } 179 180 static int proc_cwd_link(struct inode *inode, struct path *path) 181 { 182 struct task_struct *task = get_proc_task(inode); 183 int result = -ENOENT; 184 185 if (task) { 186 result = get_fs_path(task, path, 0); 187 put_task_struct(task); 188 } 189 return result; 190 } 191 192 static int proc_root_link(struct inode *inode, struct path *path) 193 { 194 struct task_struct *task = get_proc_task(inode); 195 int result = -ENOENT; 196 197 if (task) { 198 result = get_fs_path(task, path, 1); 199 put_task_struct(task); 200 } 201 return result; 202 } 203 204 /* 205 * Return zero if current may access user memory in @task, -error if not. 206 */ 207 static int check_mem_permission(struct task_struct *task) 208 { 209 /* 210 * A task can always look at itself, in case it chooses 211 * to use system calls instead of load instructions. 212 */ 213 if (task == current) 214 return 0; 215 216 /* 217 * If current is actively ptrace'ing, and would also be 218 * permitted to freshly attach with ptrace now, permit it. 219 */ 220 if (task_is_stopped_or_traced(task)) { 221 int match; 222 rcu_read_lock(); 223 match = (tracehook_tracer_task(task) == current); 224 rcu_read_unlock(); 225 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH)) 226 return 0; 227 } 228 229 /* 230 * Noone else is allowed. 231 */ 232 return -EPERM; 233 } 234 235 struct mm_struct *mm_for_maps(struct task_struct *task) 236 { 237 struct mm_struct *mm; 238 239 if (mutex_lock_killable(&task->cred_guard_mutex)) 240 return NULL; 241 242 mm = get_task_mm(task); 243 if (mm && mm != current->mm && 244 !ptrace_may_access(task, PTRACE_MODE_READ)) { 245 mmput(mm); 246 mm = NULL; 247 } 248 mutex_unlock(&task->cred_guard_mutex); 249 250 return mm; 251 } 252 253 static int proc_pid_cmdline(struct task_struct *task, char * buffer) 254 { 255 int res = 0; 256 unsigned int len; 257 struct mm_struct *mm = get_task_mm(task); 258 if (!mm) 259 goto out; 260 if (!mm->arg_end) 261 goto out_mm; /* Shh! No looking before we're done */ 262 263 len = mm->arg_end - mm->arg_start; 264 265 if (len > PAGE_SIZE) 266 len = PAGE_SIZE; 267 268 res = access_process_vm(task, mm->arg_start, buffer, len, 0); 269 270 // If the nul at the end of args has been overwritten, then 271 // assume application is using setproctitle(3). 272 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) { 273 len = strnlen(buffer, res); 274 if (len < res) { 275 res = len; 276 } else { 277 len = mm->env_end - mm->env_start; 278 if (len > PAGE_SIZE - res) 279 len = PAGE_SIZE - res; 280 res += access_process_vm(task, mm->env_start, buffer+res, len, 0); 281 res = strnlen(buffer, res); 282 } 283 } 284 out_mm: 285 mmput(mm); 286 out: 287 return res; 288 } 289 290 static int proc_pid_auxv(struct task_struct *task, char *buffer) 291 { 292 int res = 0; 293 struct mm_struct *mm = get_task_mm(task); 294 if (mm) { 295 unsigned int nwords = 0; 296 do { 297 nwords += 2; 298 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 299 res = nwords * sizeof(mm->saved_auxv[0]); 300 if (res > PAGE_SIZE) 301 res = PAGE_SIZE; 302 memcpy(buffer, mm->saved_auxv, res); 303 mmput(mm); 304 } 305 return res; 306 } 307 308 309 #ifdef CONFIG_KALLSYMS 310 /* 311 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 312 * Returns the resolved symbol. If that fails, simply return the address. 313 */ 314 static int proc_pid_wchan(struct task_struct *task, char *buffer) 315 { 316 unsigned long wchan; 317 char symname[KSYM_NAME_LEN]; 318 319 wchan = get_wchan(task); 320 321 if (lookup_symbol_name(wchan, symname) < 0) 322 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 323 return 0; 324 else 325 return sprintf(buffer, "%lu", wchan); 326 else 327 return sprintf(buffer, "%s", symname); 328 } 329 #endif /* CONFIG_KALLSYMS */ 330 331 #ifdef CONFIG_STACKTRACE 332 333 #define MAX_STACK_TRACE_DEPTH 64 334 335 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, 336 struct pid *pid, struct task_struct *task) 337 { 338 struct stack_trace trace; 339 unsigned long *entries; 340 int i; 341 342 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL); 343 if (!entries) 344 return -ENOMEM; 345 346 trace.nr_entries = 0; 347 trace.max_entries = MAX_STACK_TRACE_DEPTH; 348 trace.entries = entries; 349 trace.skip = 0; 350 save_stack_trace_tsk(task, &trace); 351 352 for (i = 0; i < trace.nr_entries; i++) { 353 seq_printf(m, "[<%p>] %pS\n", 354 (void *)entries[i], (void *)entries[i]); 355 } 356 kfree(entries); 357 358 return 0; 359 } 360 #endif 361 362 #ifdef CONFIG_SCHEDSTATS 363 /* 364 * Provides /proc/PID/schedstat 365 */ 366 static int proc_pid_schedstat(struct task_struct *task, char *buffer) 367 { 368 return sprintf(buffer, "%llu %llu %lu\n", 369 (unsigned long long)task->se.sum_exec_runtime, 370 (unsigned long long)task->sched_info.run_delay, 371 task->sched_info.pcount); 372 } 373 #endif 374 375 #ifdef CONFIG_LATENCYTOP 376 static int lstats_show_proc(struct seq_file *m, void *v) 377 { 378 int i; 379 struct inode *inode = m->private; 380 struct task_struct *task = get_proc_task(inode); 381 382 if (!task) 383 return -ESRCH; 384 seq_puts(m, "Latency Top version : v0.1\n"); 385 for (i = 0; i < 32; i++) { 386 if (task->latency_record[i].backtrace[0]) { 387 int q; 388 seq_printf(m, "%i %li %li ", 389 task->latency_record[i].count, 390 task->latency_record[i].time, 391 task->latency_record[i].max); 392 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 393 char sym[KSYM_SYMBOL_LEN]; 394 char *c; 395 if (!task->latency_record[i].backtrace[q]) 396 break; 397 if (task->latency_record[i].backtrace[q] == ULONG_MAX) 398 break; 399 sprint_symbol(sym, task->latency_record[i].backtrace[q]); 400 c = strchr(sym, '+'); 401 if (c) 402 *c = 0; 403 seq_printf(m, "%s ", sym); 404 } 405 seq_printf(m, "\n"); 406 } 407 408 } 409 put_task_struct(task); 410 return 0; 411 } 412 413 static int lstats_open(struct inode *inode, struct file *file) 414 { 415 return single_open(file, lstats_show_proc, inode); 416 } 417 418 static ssize_t lstats_write(struct file *file, const char __user *buf, 419 size_t count, loff_t *offs) 420 { 421 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 422 423 if (!task) 424 return -ESRCH; 425 clear_all_latency_tracing(task); 426 put_task_struct(task); 427 428 return count; 429 } 430 431 static const struct file_operations proc_lstats_operations = { 432 .open = lstats_open, 433 .read = seq_read, 434 .write = lstats_write, 435 .llseek = seq_lseek, 436 .release = single_release, 437 }; 438 439 #endif 440 441 /* The badness from the OOM killer */ 442 unsigned long badness(struct task_struct *p, unsigned long uptime); 443 static int proc_oom_score(struct task_struct *task, char *buffer) 444 { 445 unsigned long points; 446 struct timespec uptime; 447 448 do_posix_clock_monotonic_gettime(&uptime); 449 read_lock(&tasklist_lock); 450 points = badness(task->group_leader, uptime.tv_sec); 451 read_unlock(&tasklist_lock); 452 return sprintf(buffer, "%lu\n", points); 453 } 454 455 struct limit_names { 456 char *name; 457 char *unit; 458 }; 459 460 static const struct limit_names lnames[RLIM_NLIMITS] = { 461 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 462 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 463 [RLIMIT_DATA] = {"Max data size", "bytes"}, 464 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 465 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 466 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 467 [RLIMIT_NPROC] = {"Max processes", "processes"}, 468 [RLIMIT_NOFILE] = {"Max open files", "files"}, 469 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 470 [RLIMIT_AS] = {"Max address space", "bytes"}, 471 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 472 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 473 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 474 [RLIMIT_NICE] = {"Max nice priority", NULL}, 475 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 476 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 477 }; 478 479 /* Display limits for a process */ 480 static int proc_pid_limits(struct task_struct *task, char *buffer) 481 { 482 unsigned int i; 483 int count = 0; 484 unsigned long flags; 485 char *bufptr = buffer; 486 487 struct rlimit rlim[RLIM_NLIMITS]; 488 489 if (!lock_task_sighand(task, &flags)) 490 return 0; 491 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 492 unlock_task_sighand(task, &flags); 493 494 /* 495 * print the file header 496 */ 497 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n", 498 "Limit", "Soft Limit", "Hard Limit", "Units"); 499 500 for (i = 0; i < RLIM_NLIMITS; i++) { 501 if (rlim[i].rlim_cur == RLIM_INFINITY) 502 count += sprintf(&bufptr[count], "%-25s %-20s ", 503 lnames[i].name, "unlimited"); 504 else 505 count += sprintf(&bufptr[count], "%-25s %-20lu ", 506 lnames[i].name, rlim[i].rlim_cur); 507 508 if (rlim[i].rlim_max == RLIM_INFINITY) 509 count += sprintf(&bufptr[count], "%-20s ", "unlimited"); 510 else 511 count += sprintf(&bufptr[count], "%-20lu ", 512 rlim[i].rlim_max); 513 514 if (lnames[i].unit) 515 count += sprintf(&bufptr[count], "%-10s\n", 516 lnames[i].unit); 517 else 518 count += sprintf(&bufptr[count], "\n"); 519 } 520 521 return count; 522 } 523 524 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 525 static int proc_pid_syscall(struct task_struct *task, char *buffer) 526 { 527 long nr; 528 unsigned long args[6], sp, pc; 529 530 if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) 531 return sprintf(buffer, "running\n"); 532 533 if (nr < 0) 534 return sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc); 535 536 return sprintf(buffer, 537 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", 538 nr, 539 args[0], args[1], args[2], args[3], args[4], args[5], 540 sp, pc); 541 } 542 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 543 544 /************************************************************************/ 545 /* Here the fs part begins */ 546 /************************************************************************/ 547 548 /* permission checks */ 549 static int proc_fd_access_allowed(struct inode *inode) 550 { 551 struct task_struct *task; 552 int allowed = 0; 553 /* Allow access to a task's file descriptors if it is us or we 554 * may use ptrace attach to the process and find out that 555 * information. 556 */ 557 task = get_proc_task(inode); 558 if (task) { 559 allowed = ptrace_may_access(task, PTRACE_MODE_READ); 560 put_task_struct(task); 561 } 562 return allowed; 563 } 564 565 static int proc_setattr(struct dentry *dentry, struct iattr *attr) 566 { 567 int error; 568 struct inode *inode = dentry->d_inode; 569 570 if (attr->ia_valid & ATTR_MODE) 571 return -EPERM; 572 573 error = inode_change_ok(inode, attr); 574 if (!error) 575 error = inode_setattr(inode, attr); 576 return error; 577 } 578 579 static const struct inode_operations proc_def_inode_operations = { 580 .setattr = proc_setattr, 581 }; 582 583 static int mounts_open_common(struct inode *inode, struct file *file, 584 const struct seq_operations *op) 585 { 586 struct task_struct *task = get_proc_task(inode); 587 struct nsproxy *nsp; 588 struct mnt_namespace *ns = NULL; 589 struct path root; 590 struct proc_mounts *p; 591 int ret = -EINVAL; 592 593 if (task) { 594 rcu_read_lock(); 595 nsp = task_nsproxy(task); 596 if (nsp) { 597 ns = nsp->mnt_ns; 598 if (ns) 599 get_mnt_ns(ns); 600 } 601 rcu_read_unlock(); 602 if (ns && get_fs_path(task, &root, 1) == 0) 603 ret = 0; 604 put_task_struct(task); 605 } 606 607 if (!ns) 608 goto err; 609 if (ret) 610 goto err_put_ns; 611 612 ret = -ENOMEM; 613 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL); 614 if (!p) 615 goto err_put_path; 616 617 file->private_data = &p->m; 618 ret = seq_open(file, op); 619 if (ret) 620 goto err_free; 621 622 p->m.private = p; 623 p->ns = ns; 624 p->root = root; 625 p->event = ns->event; 626 627 return 0; 628 629 err_free: 630 kfree(p); 631 err_put_path: 632 path_put(&root); 633 err_put_ns: 634 put_mnt_ns(ns); 635 err: 636 return ret; 637 } 638 639 static int mounts_release(struct inode *inode, struct file *file) 640 { 641 struct proc_mounts *p = file->private_data; 642 path_put(&p->root); 643 put_mnt_ns(p->ns); 644 return seq_release(inode, file); 645 } 646 647 static unsigned mounts_poll(struct file *file, poll_table *wait) 648 { 649 struct proc_mounts *p = file->private_data; 650 struct mnt_namespace *ns = p->ns; 651 unsigned res = POLLIN | POLLRDNORM; 652 653 poll_wait(file, &ns->poll, wait); 654 655 spin_lock(&vfsmount_lock); 656 if (p->event != ns->event) { 657 p->event = ns->event; 658 res |= POLLERR | POLLPRI; 659 } 660 spin_unlock(&vfsmount_lock); 661 662 return res; 663 } 664 665 static int mounts_open(struct inode *inode, struct file *file) 666 { 667 return mounts_open_common(inode, file, &mounts_op); 668 } 669 670 static const struct file_operations proc_mounts_operations = { 671 .open = mounts_open, 672 .read = seq_read, 673 .llseek = seq_lseek, 674 .release = mounts_release, 675 .poll = mounts_poll, 676 }; 677 678 static int mountinfo_open(struct inode *inode, struct file *file) 679 { 680 return mounts_open_common(inode, file, &mountinfo_op); 681 } 682 683 static const struct file_operations proc_mountinfo_operations = { 684 .open = mountinfo_open, 685 .read = seq_read, 686 .llseek = seq_lseek, 687 .release = mounts_release, 688 .poll = mounts_poll, 689 }; 690 691 static int mountstats_open(struct inode *inode, struct file *file) 692 { 693 return mounts_open_common(inode, file, &mountstats_op); 694 } 695 696 static const struct file_operations proc_mountstats_operations = { 697 .open = mountstats_open, 698 .read = seq_read, 699 .llseek = seq_lseek, 700 .release = mounts_release, 701 }; 702 703 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */ 704 705 static ssize_t proc_info_read(struct file * file, char __user * buf, 706 size_t count, loff_t *ppos) 707 { 708 struct inode * inode = file->f_path.dentry->d_inode; 709 unsigned long page; 710 ssize_t length; 711 struct task_struct *task = get_proc_task(inode); 712 713 length = -ESRCH; 714 if (!task) 715 goto out_no_task; 716 717 if (count > PROC_BLOCK_SIZE) 718 count = PROC_BLOCK_SIZE; 719 720 length = -ENOMEM; 721 if (!(page = __get_free_page(GFP_TEMPORARY))) 722 goto out; 723 724 length = PROC_I(inode)->op.proc_read(task, (char*)page); 725 726 if (length >= 0) 727 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length); 728 free_page(page); 729 out: 730 put_task_struct(task); 731 out_no_task: 732 return length; 733 } 734 735 static const struct file_operations proc_info_file_operations = { 736 .read = proc_info_read, 737 }; 738 739 static int proc_single_show(struct seq_file *m, void *v) 740 { 741 struct inode *inode = m->private; 742 struct pid_namespace *ns; 743 struct pid *pid; 744 struct task_struct *task; 745 int ret; 746 747 ns = inode->i_sb->s_fs_info; 748 pid = proc_pid(inode); 749 task = get_pid_task(pid, PIDTYPE_PID); 750 if (!task) 751 return -ESRCH; 752 753 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 754 755 put_task_struct(task); 756 return ret; 757 } 758 759 static int proc_single_open(struct inode *inode, struct file *filp) 760 { 761 int ret; 762 ret = single_open(filp, proc_single_show, NULL); 763 if (!ret) { 764 struct seq_file *m = filp->private_data; 765 766 m->private = inode; 767 } 768 return ret; 769 } 770 771 static const struct file_operations proc_single_file_operations = { 772 .open = proc_single_open, 773 .read = seq_read, 774 .llseek = seq_lseek, 775 .release = single_release, 776 }; 777 778 static int mem_open(struct inode* inode, struct file* file) 779 { 780 file->private_data = (void*)((long)current->self_exec_id); 781 return 0; 782 } 783 784 static ssize_t mem_read(struct file * file, char __user * buf, 785 size_t count, loff_t *ppos) 786 { 787 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 788 char *page; 789 unsigned long src = *ppos; 790 int ret = -ESRCH; 791 struct mm_struct *mm; 792 793 if (!task) 794 goto out_no_task; 795 796 if (check_mem_permission(task)) 797 goto out; 798 799 ret = -ENOMEM; 800 page = (char *)__get_free_page(GFP_TEMPORARY); 801 if (!page) 802 goto out; 803 804 ret = 0; 805 806 mm = get_task_mm(task); 807 if (!mm) 808 goto out_free; 809 810 ret = -EIO; 811 812 if (file->private_data != (void*)((long)current->self_exec_id)) 813 goto out_put; 814 815 ret = 0; 816 817 while (count > 0) { 818 int this_len, retval; 819 820 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 821 retval = access_process_vm(task, src, page, this_len, 0); 822 if (!retval || check_mem_permission(task)) { 823 if (!ret) 824 ret = -EIO; 825 break; 826 } 827 828 if (copy_to_user(buf, page, retval)) { 829 ret = -EFAULT; 830 break; 831 } 832 833 ret += retval; 834 src += retval; 835 buf += retval; 836 count -= retval; 837 } 838 *ppos = src; 839 840 out_put: 841 mmput(mm); 842 out_free: 843 free_page((unsigned long) page); 844 out: 845 put_task_struct(task); 846 out_no_task: 847 return ret; 848 } 849 850 #define mem_write NULL 851 852 #ifndef mem_write 853 /* This is a security hazard */ 854 static ssize_t mem_write(struct file * file, const char __user *buf, 855 size_t count, loff_t *ppos) 856 { 857 int copied; 858 char *page; 859 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 860 unsigned long dst = *ppos; 861 862 copied = -ESRCH; 863 if (!task) 864 goto out_no_task; 865 866 if (check_mem_permission(task)) 867 goto out; 868 869 copied = -ENOMEM; 870 page = (char *)__get_free_page(GFP_TEMPORARY); 871 if (!page) 872 goto out; 873 874 copied = 0; 875 while (count > 0) { 876 int this_len, retval; 877 878 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 879 if (copy_from_user(page, buf, this_len)) { 880 copied = -EFAULT; 881 break; 882 } 883 retval = access_process_vm(task, dst, page, this_len, 1); 884 if (!retval) { 885 if (!copied) 886 copied = -EIO; 887 break; 888 } 889 copied += retval; 890 buf += retval; 891 dst += retval; 892 count -= retval; 893 } 894 *ppos = dst; 895 free_page((unsigned long) page); 896 out: 897 put_task_struct(task); 898 out_no_task: 899 return copied; 900 } 901 #endif 902 903 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 904 { 905 switch (orig) { 906 case 0: 907 file->f_pos = offset; 908 break; 909 case 1: 910 file->f_pos += offset; 911 break; 912 default: 913 return -EINVAL; 914 } 915 force_successful_syscall_return(); 916 return file->f_pos; 917 } 918 919 static const struct file_operations proc_mem_operations = { 920 .llseek = mem_lseek, 921 .read = mem_read, 922 .write = mem_write, 923 .open = mem_open, 924 }; 925 926 static ssize_t environ_read(struct file *file, char __user *buf, 927 size_t count, loff_t *ppos) 928 { 929 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 930 char *page; 931 unsigned long src = *ppos; 932 int ret = -ESRCH; 933 struct mm_struct *mm; 934 935 if (!task) 936 goto out_no_task; 937 938 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 939 goto out; 940 941 ret = -ENOMEM; 942 page = (char *)__get_free_page(GFP_TEMPORARY); 943 if (!page) 944 goto out; 945 946 ret = 0; 947 948 mm = get_task_mm(task); 949 if (!mm) 950 goto out_free; 951 952 while (count > 0) { 953 int this_len, retval, max_len; 954 955 this_len = mm->env_end - (mm->env_start + src); 956 957 if (this_len <= 0) 958 break; 959 960 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 961 this_len = (this_len > max_len) ? max_len : this_len; 962 963 retval = access_process_vm(task, (mm->env_start + src), 964 page, this_len, 0); 965 966 if (retval <= 0) { 967 ret = retval; 968 break; 969 } 970 971 if (copy_to_user(buf, page, retval)) { 972 ret = -EFAULT; 973 break; 974 } 975 976 ret += retval; 977 src += retval; 978 buf += retval; 979 count -= retval; 980 } 981 *ppos = src; 982 983 mmput(mm); 984 out_free: 985 free_page((unsigned long) page); 986 out: 987 put_task_struct(task); 988 out_no_task: 989 return ret; 990 } 991 992 static const struct file_operations proc_environ_operations = { 993 .read = environ_read, 994 }; 995 996 static ssize_t oom_adjust_read(struct file *file, char __user *buf, 997 size_t count, loff_t *ppos) 998 { 999 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 1000 char buffer[PROC_NUMBUF]; 1001 size_t len; 1002 int oom_adjust = OOM_DISABLE; 1003 unsigned long flags; 1004 1005 if (!task) 1006 return -ESRCH; 1007 1008 if (lock_task_sighand(task, &flags)) { 1009 oom_adjust = task->signal->oom_adj; 1010 unlock_task_sighand(task, &flags); 1011 } 1012 1013 put_task_struct(task); 1014 1015 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); 1016 1017 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1018 } 1019 1020 static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 1021 size_t count, loff_t *ppos) 1022 { 1023 struct task_struct *task; 1024 char buffer[PROC_NUMBUF]; 1025 long oom_adjust; 1026 unsigned long flags; 1027 int err; 1028 1029 memset(buffer, 0, sizeof(buffer)); 1030 if (count > sizeof(buffer) - 1) 1031 count = sizeof(buffer) - 1; 1032 if (copy_from_user(buffer, buf, count)) 1033 return -EFAULT; 1034 1035 err = strict_strtol(strstrip(buffer), 0, &oom_adjust); 1036 if (err) 1037 return -EINVAL; 1038 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && 1039 oom_adjust != OOM_DISABLE) 1040 return -EINVAL; 1041 1042 task = get_proc_task(file->f_path.dentry->d_inode); 1043 if (!task) 1044 return -ESRCH; 1045 if (!lock_task_sighand(task, &flags)) { 1046 put_task_struct(task); 1047 return -ESRCH; 1048 } 1049 1050 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) { 1051 unlock_task_sighand(task, &flags); 1052 put_task_struct(task); 1053 return -EACCES; 1054 } 1055 1056 task->signal->oom_adj = oom_adjust; 1057 1058 unlock_task_sighand(task, &flags); 1059 put_task_struct(task); 1060 1061 return count; 1062 } 1063 1064 static const struct file_operations proc_oom_adjust_operations = { 1065 .read = oom_adjust_read, 1066 .write = oom_adjust_write, 1067 }; 1068 1069 #ifdef CONFIG_AUDITSYSCALL 1070 #define TMPBUFLEN 21 1071 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1072 size_t count, loff_t *ppos) 1073 { 1074 struct inode * inode = file->f_path.dentry->d_inode; 1075 struct task_struct *task = get_proc_task(inode); 1076 ssize_t length; 1077 char tmpbuf[TMPBUFLEN]; 1078 1079 if (!task) 1080 return -ESRCH; 1081 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1082 audit_get_loginuid(task)); 1083 put_task_struct(task); 1084 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1085 } 1086 1087 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1088 size_t count, loff_t *ppos) 1089 { 1090 struct inode * inode = file->f_path.dentry->d_inode; 1091 char *page, *tmp; 1092 ssize_t length; 1093 uid_t loginuid; 1094 1095 if (!capable(CAP_AUDIT_CONTROL)) 1096 return -EPERM; 1097 1098 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) 1099 return -EPERM; 1100 1101 if (count >= PAGE_SIZE) 1102 count = PAGE_SIZE - 1; 1103 1104 if (*ppos != 0) { 1105 /* No partial writes. */ 1106 return -EINVAL; 1107 } 1108 page = (char*)__get_free_page(GFP_TEMPORARY); 1109 if (!page) 1110 return -ENOMEM; 1111 length = -EFAULT; 1112 if (copy_from_user(page, buf, count)) 1113 goto out_free_page; 1114 1115 page[count] = '\0'; 1116 loginuid = simple_strtoul(page, &tmp, 10); 1117 if (tmp == page) { 1118 length = -EINVAL; 1119 goto out_free_page; 1120 1121 } 1122 length = audit_set_loginuid(current, loginuid); 1123 if (likely(length == 0)) 1124 length = count; 1125 1126 out_free_page: 1127 free_page((unsigned long) page); 1128 return length; 1129 } 1130 1131 static const struct file_operations proc_loginuid_operations = { 1132 .read = proc_loginuid_read, 1133 .write = proc_loginuid_write, 1134 }; 1135 1136 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1137 size_t count, loff_t *ppos) 1138 { 1139 struct inode * inode = file->f_path.dentry->d_inode; 1140 struct task_struct *task = get_proc_task(inode); 1141 ssize_t length; 1142 char tmpbuf[TMPBUFLEN]; 1143 1144 if (!task) 1145 return -ESRCH; 1146 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1147 audit_get_sessionid(task)); 1148 put_task_struct(task); 1149 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1150 } 1151 1152 static const struct file_operations proc_sessionid_operations = { 1153 .read = proc_sessionid_read, 1154 }; 1155 #endif 1156 1157 #ifdef CONFIG_FAULT_INJECTION 1158 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1159 size_t count, loff_t *ppos) 1160 { 1161 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1162 char buffer[PROC_NUMBUF]; 1163 size_t len; 1164 int make_it_fail; 1165 1166 if (!task) 1167 return -ESRCH; 1168 make_it_fail = task->make_it_fail; 1169 put_task_struct(task); 1170 1171 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1172 1173 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1174 } 1175 1176 static ssize_t proc_fault_inject_write(struct file * file, 1177 const char __user * buf, size_t count, loff_t *ppos) 1178 { 1179 struct task_struct *task; 1180 char buffer[PROC_NUMBUF], *end; 1181 int make_it_fail; 1182 1183 if (!capable(CAP_SYS_RESOURCE)) 1184 return -EPERM; 1185 memset(buffer, 0, sizeof(buffer)); 1186 if (count > sizeof(buffer) - 1) 1187 count = sizeof(buffer) - 1; 1188 if (copy_from_user(buffer, buf, count)) 1189 return -EFAULT; 1190 make_it_fail = simple_strtol(strstrip(buffer), &end, 0); 1191 if (*end) 1192 return -EINVAL; 1193 task = get_proc_task(file->f_dentry->d_inode); 1194 if (!task) 1195 return -ESRCH; 1196 task->make_it_fail = make_it_fail; 1197 put_task_struct(task); 1198 1199 return count; 1200 } 1201 1202 static const struct file_operations proc_fault_inject_operations = { 1203 .read = proc_fault_inject_read, 1204 .write = proc_fault_inject_write, 1205 }; 1206 #endif 1207 1208 1209 #ifdef CONFIG_SCHED_DEBUG 1210 /* 1211 * Print out various scheduling related per-task fields: 1212 */ 1213 static int sched_show(struct seq_file *m, void *v) 1214 { 1215 struct inode *inode = m->private; 1216 struct task_struct *p; 1217 1218 p = get_proc_task(inode); 1219 if (!p) 1220 return -ESRCH; 1221 proc_sched_show_task(p, m); 1222 1223 put_task_struct(p); 1224 1225 return 0; 1226 } 1227 1228 static ssize_t 1229 sched_write(struct file *file, const char __user *buf, 1230 size_t count, loff_t *offset) 1231 { 1232 struct inode *inode = file->f_path.dentry->d_inode; 1233 struct task_struct *p; 1234 1235 p = get_proc_task(inode); 1236 if (!p) 1237 return -ESRCH; 1238 proc_sched_set_task(p); 1239 1240 put_task_struct(p); 1241 1242 return count; 1243 } 1244 1245 static int sched_open(struct inode *inode, struct file *filp) 1246 { 1247 int ret; 1248 1249 ret = single_open(filp, sched_show, NULL); 1250 if (!ret) { 1251 struct seq_file *m = filp->private_data; 1252 1253 m->private = inode; 1254 } 1255 return ret; 1256 } 1257 1258 static const struct file_operations proc_pid_sched_operations = { 1259 .open = sched_open, 1260 .read = seq_read, 1261 .write = sched_write, 1262 .llseek = seq_lseek, 1263 .release = single_release, 1264 }; 1265 1266 #endif 1267 1268 /* 1269 * We added or removed a vma mapping the executable. The vmas are only mapped 1270 * during exec and are not mapped with the mmap system call. 1271 * Callers must hold down_write() on the mm's mmap_sem for these 1272 */ 1273 void added_exe_file_vma(struct mm_struct *mm) 1274 { 1275 mm->num_exe_file_vmas++; 1276 } 1277 1278 void removed_exe_file_vma(struct mm_struct *mm) 1279 { 1280 mm->num_exe_file_vmas--; 1281 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){ 1282 fput(mm->exe_file); 1283 mm->exe_file = NULL; 1284 } 1285 1286 } 1287 1288 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) 1289 { 1290 if (new_exe_file) 1291 get_file(new_exe_file); 1292 if (mm->exe_file) 1293 fput(mm->exe_file); 1294 mm->exe_file = new_exe_file; 1295 mm->num_exe_file_vmas = 0; 1296 } 1297 1298 struct file *get_mm_exe_file(struct mm_struct *mm) 1299 { 1300 struct file *exe_file; 1301 1302 /* We need mmap_sem to protect against races with removal of 1303 * VM_EXECUTABLE vmas */ 1304 down_read(&mm->mmap_sem); 1305 exe_file = mm->exe_file; 1306 if (exe_file) 1307 get_file(exe_file); 1308 up_read(&mm->mmap_sem); 1309 return exe_file; 1310 } 1311 1312 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm) 1313 { 1314 /* It's safe to write the exe_file pointer without exe_file_lock because 1315 * this is called during fork when the task is not yet in /proc */ 1316 newmm->exe_file = get_mm_exe_file(oldmm); 1317 } 1318 1319 static int proc_exe_link(struct inode *inode, struct path *exe_path) 1320 { 1321 struct task_struct *task; 1322 struct mm_struct *mm; 1323 struct file *exe_file; 1324 1325 task = get_proc_task(inode); 1326 if (!task) 1327 return -ENOENT; 1328 mm = get_task_mm(task); 1329 put_task_struct(task); 1330 if (!mm) 1331 return -ENOENT; 1332 exe_file = get_mm_exe_file(mm); 1333 mmput(mm); 1334 if (exe_file) { 1335 *exe_path = exe_file->f_path; 1336 path_get(&exe_file->f_path); 1337 fput(exe_file); 1338 return 0; 1339 } else 1340 return -ENOENT; 1341 } 1342 1343 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1344 { 1345 struct inode *inode = dentry->d_inode; 1346 int error = -EACCES; 1347 1348 /* We don't need a base pointer in the /proc filesystem */ 1349 path_put(&nd->path); 1350 1351 /* Are we allowed to snoop on the tasks file descriptors? */ 1352 if (!proc_fd_access_allowed(inode)) 1353 goto out; 1354 1355 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path); 1356 nd->last_type = LAST_BIND; 1357 out: 1358 return ERR_PTR(error); 1359 } 1360 1361 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1362 { 1363 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1364 char *pathname; 1365 int len; 1366 1367 if (!tmp) 1368 return -ENOMEM; 1369 1370 pathname = d_path(path, tmp, PAGE_SIZE); 1371 len = PTR_ERR(pathname); 1372 if (IS_ERR(pathname)) 1373 goto out; 1374 len = tmp + PAGE_SIZE - 1 - pathname; 1375 1376 if (len > buflen) 1377 len = buflen; 1378 if (copy_to_user(buffer, pathname, len)) 1379 len = -EFAULT; 1380 out: 1381 free_page((unsigned long)tmp); 1382 return len; 1383 } 1384 1385 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1386 { 1387 int error = -EACCES; 1388 struct inode *inode = dentry->d_inode; 1389 struct path path; 1390 1391 /* Are we allowed to snoop on the tasks file descriptors? */ 1392 if (!proc_fd_access_allowed(inode)) 1393 goto out; 1394 1395 error = PROC_I(inode)->op.proc_get_link(inode, &path); 1396 if (error) 1397 goto out; 1398 1399 error = do_proc_readlink(&path, buffer, buflen); 1400 path_put(&path); 1401 out: 1402 return error; 1403 } 1404 1405 static const struct inode_operations proc_pid_link_inode_operations = { 1406 .readlink = proc_pid_readlink, 1407 .follow_link = proc_pid_follow_link, 1408 .setattr = proc_setattr, 1409 }; 1410 1411 1412 /* building an inode */ 1413 1414 static int task_dumpable(struct task_struct *task) 1415 { 1416 int dumpable = 0; 1417 struct mm_struct *mm; 1418 1419 task_lock(task); 1420 mm = task->mm; 1421 if (mm) 1422 dumpable = get_dumpable(mm); 1423 task_unlock(task); 1424 if(dumpable == 1) 1425 return 1; 1426 return 0; 1427 } 1428 1429 1430 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1431 { 1432 struct inode * inode; 1433 struct proc_inode *ei; 1434 const struct cred *cred; 1435 1436 /* We need a new inode */ 1437 1438 inode = new_inode(sb); 1439 if (!inode) 1440 goto out; 1441 1442 /* Common stuff */ 1443 ei = PROC_I(inode); 1444 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1445 inode->i_op = &proc_def_inode_operations; 1446 1447 /* 1448 * grab the reference to task. 1449 */ 1450 ei->pid = get_task_pid(task, PIDTYPE_PID); 1451 if (!ei->pid) 1452 goto out_unlock; 1453 1454 if (task_dumpable(task)) { 1455 rcu_read_lock(); 1456 cred = __task_cred(task); 1457 inode->i_uid = cred->euid; 1458 inode->i_gid = cred->egid; 1459 rcu_read_unlock(); 1460 } 1461 security_task_to_inode(task, inode); 1462 1463 out: 1464 return inode; 1465 1466 out_unlock: 1467 iput(inode); 1468 return NULL; 1469 } 1470 1471 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1472 { 1473 struct inode *inode = dentry->d_inode; 1474 struct task_struct *task; 1475 const struct cred *cred; 1476 1477 generic_fillattr(inode, stat); 1478 1479 rcu_read_lock(); 1480 stat->uid = 0; 1481 stat->gid = 0; 1482 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1483 if (task) { 1484 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1485 task_dumpable(task)) { 1486 cred = __task_cred(task); 1487 stat->uid = cred->euid; 1488 stat->gid = cred->egid; 1489 } 1490 } 1491 rcu_read_unlock(); 1492 return 0; 1493 } 1494 1495 /* dentry stuff */ 1496 1497 /* 1498 * Exceptional case: normally we are not allowed to unhash a busy 1499 * directory. In this case, however, we can do it - no aliasing problems 1500 * due to the way we treat inodes. 1501 * 1502 * Rewrite the inode's ownerships here because the owning task may have 1503 * performed a setuid(), etc. 1504 * 1505 * Before the /proc/pid/status file was created the only way to read 1506 * the effective uid of a /process was to stat /proc/pid. Reading 1507 * /proc/pid/status is slow enough that procps and other packages 1508 * kept stating /proc/pid. To keep the rules in /proc simple I have 1509 * made this apply to all per process world readable and executable 1510 * directories. 1511 */ 1512 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1513 { 1514 struct inode *inode = dentry->d_inode; 1515 struct task_struct *task = get_proc_task(inode); 1516 const struct cred *cred; 1517 1518 if (task) { 1519 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1520 task_dumpable(task)) { 1521 rcu_read_lock(); 1522 cred = __task_cred(task); 1523 inode->i_uid = cred->euid; 1524 inode->i_gid = cred->egid; 1525 rcu_read_unlock(); 1526 } else { 1527 inode->i_uid = 0; 1528 inode->i_gid = 0; 1529 } 1530 inode->i_mode &= ~(S_ISUID | S_ISGID); 1531 security_task_to_inode(task, inode); 1532 put_task_struct(task); 1533 return 1; 1534 } 1535 d_drop(dentry); 1536 return 0; 1537 } 1538 1539 static int pid_delete_dentry(struct dentry * dentry) 1540 { 1541 /* Is the task we represent dead? 1542 * If so, then don't put the dentry on the lru list, 1543 * kill it immediately. 1544 */ 1545 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1546 } 1547 1548 static const struct dentry_operations pid_dentry_operations = 1549 { 1550 .d_revalidate = pid_revalidate, 1551 .d_delete = pid_delete_dentry, 1552 }; 1553 1554 /* Lookups */ 1555 1556 typedef struct dentry *instantiate_t(struct inode *, struct dentry *, 1557 struct task_struct *, const void *); 1558 1559 /* 1560 * Fill a directory entry. 1561 * 1562 * If possible create the dcache entry and derive our inode number and 1563 * file type from dcache entry. 1564 * 1565 * Since all of the proc inode numbers are dynamically generated, the inode 1566 * numbers do not exist until the inode is cache. This means creating the 1567 * the dcache entry in readdir is necessary to keep the inode numbers 1568 * reported by readdir in sync with the inode numbers reported 1569 * by stat. 1570 */ 1571 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1572 char *name, int len, 1573 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1574 { 1575 struct dentry *child, *dir = filp->f_path.dentry; 1576 struct inode *inode; 1577 struct qstr qname; 1578 ino_t ino = 0; 1579 unsigned type = DT_UNKNOWN; 1580 1581 qname.name = name; 1582 qname.len = len; 1583 qname.hash = full_name_hash(name, len); 1584 1585 child = d_lookup(dir, &qname); 1586 if (!child) { 1587 struct dentry *new; 1588 new = d_alloc(dir, &qname); 1589 if (new) { 1590 child = instantiate(dir->d_inode, new, task, ptr); 1591 if (child) 1592 dput(new); 1593 else 1594 child = new; 1595 } 1596 } 1597 if (!child || IS_ERR(child) || !child->d_inode) 1598 goto end_instantiate; 1599 inode = child->d_inode; 1600 if (inode) { 1601 ino = inode->i_ino; 1602 type = inode->i_mode >> 12; 1603 } 1604 dput(child); 1605 end_instantiate: 1606 if (!ino) 1607 ino = find_inode_number(dir, &qname); 1608 if (!ino) 1609 ino = 1; 1610 return filldir(dirent, name, len, filp->f_pos, ino, type); 1611 } 1612 1613 static unsigned name_to_int(struct dentry *dentry) 1614 { 1615 const char *name = dentry->d_name.name; 1616 int len = dentry->d_name.len; 1617 unsigned n = 0; 1618 1619 if (len > 1 && *name == '0') 1620 goto out; 1621 while (len-- > 0) { 1622 unsigned c = *name++ - '0'; 1623 if (c > 9) 1624 goto out; 1625 if (n >= (~0U-9)/10) 1626 goto out; 1627 n *= 10; 1628 n += c; 1629 } 1630 return n; 1631 out: 1632 return ~0U; 1633 } 1634 1635 #define PROC_FDINFO_MAX 64 1636 1637 static int proc_fd_info(struct inode *inode, struct path *path, char *info) 1638 { 1639 struct task_struct *task = get_proc_task(inode); 1640 struct files_struct *files = NULL; 1641 struct file *file; 1642 int fd = proc_fd(inode); 1643 1644 if (task) { 1645 files = get_files_struct(task); 1646 put_task_struct(task); 1647 } 1648 if (files) { 1649 /* 1650 * We are not taking a ref to the file structure, so we must 1651 * hold ->file_lock. 1652 */ 1653 spin_lock(&files->file_lock); 1654 file = fcheck_files(files, fd); 1655 if (file) { 1656 if (path) { 1657 *path = file->f_path; 1658 path_get(&file->f_path); 1659 } 1660 if (info) 1661 snprintf(info, PROC_FDINFO_MAX, 1662 "pos:\t%lli\n" 1663 "flags:\t0%o\n", 1664 (long long) file->f_pos, 1665 file->f_flags); 1666 spin_unlock(&files->file_lock); 1667 put_files_struct(files); 1668 return 0; 1669 } 1670 spin_unlock(&files->file_lock); 1671 put_files_struct(files); 1672 } 1673 return -ENOENT; 1674 } 1675 1676 static int proc_fd_link(struct inode *inode, struct path *path) 1677 { 1678 return proc_fd_info(inode, path, NULL); 1679 } 1680 1681 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1682 { 1683 struct inode *inode = dentry->d_inode; 1684 struct task_struct *task = get_proc_task(inode); 1685 int fd = proc_fd(inode); 1686 struct files_struct *files; 1687 const struct cred *cred; 1688 1689 if (task) { 1690 files = get_files_struct(task); 1691 if (files) { 1692 rcu_read_lock(); 1693 if (fcheck_files(files, fd)) { 1694 rcu_read_unlock(); 1695 put_files_struct(files); 1696 if (task_dumpable(task)) { 1697 rcu_read_lock(); 1698 cred = __task_cred(task); 1699 inode->i_uid = cred->euid; 1700 inode->i_gid = cred->egid; 1701 rcu_read_unlock(); 1702 } else { 1703 inode->i_uid = 0; 1704 inode->i_gid = 0; 1705 } 1706 inode->i_mode &= ~(S_ISUID | S_ISGID); 1707 security_task_to_inode(task, inode); 1708 put_task_struct(task); 1709 return 1; 1710 } 1711 rcu_read_unlock(); 1712 put_files_struct(files); 1713 } 1714 put_task_struct(task); 1715 } 1716 d_drop(dentry); 1717 return 0; 1718 } 1719 1720 static const struct dentry_operations tid_fd_dentry_operations = 1721 { 1722 .d_revalidate = tid_fd_revalidate, 1723 .d_delete = pid_delete_dentry, 1724 }; 1725 1726 static struct dentry *proc_fd_instantiate(struct inode *dir, 1727 struct dentry *dentry, struct task_struct *task, const void *ptr) 1728 { 1729 unsigned fd = *(const unsigned *)ptr; 1730 struct file *file; 1731 struct files_struct *files; 1732 struct inode *inode; 1733 struct proc_inode *ei; 1734 struct dentry *error = ERR_PTR(-ENOENT); 1735 1736 inode = proc_pid_make_inode(dir->i_sb, task); 1737 if (!inode) 1738 goto out; 1739 ei = PROC_I(inode); 1740 ei->fd = fd; 1741 files = get_files_struct(task); 1742 if (!files) 1743 goto out_iput; 1744 inode->i_mode = S_IFLNK; 1745 1746 /* 1747 * We are not taking a ref to the file structure, so we must 1748 * hold ->file_lock. 1749 */ 1750 spin_lock(&files->file_lock); 1751 file = fcheck_files(files, fd); 1752 if (!file) 1753 goto out_unlock; 1754 if (file->f_mode & FMODE_READ) 1755 inode->i_mode |= S_IRUSR | S_IXUSR; 1756 if (file->f_mode & FMODE_WRITE) 1757 inode->i_mode |= S_IWUSR | S_IXUSR; 1758 spin_unlock(&files->file_lock); 1759 put_files_struct(files); 1760 1761 inode->i_op = &proc_pid_link_inode_operations; 1762 inode->i_size = 64; 1763 ei->op.proc_get_link = proc_fd_link; 1764 dentry->d_op = &tid_fd_dentry_operations; 1765 d_add(dentry, inode); 1766 /* Close the race of the process dying before we return the dentry */ 1767 if (tid_fd_revalidate(dentry, NULL)) 1768 error = NULL; 1769 1770 out: 1771 return error; 1772 out_unlock: 1773 spin_unlock(&files->file_lock); 1774 put_files_struct(files); 1775 out_iput: 1776 iput(inode); 1777 goto out; 1778 } 1779 1780 static struct dentry *proc_lookupfd_common(struct inode *dir, 1781 struct dentry *dentry, 1782 instantiate_t instantiate) 1783 { 1784 struct task_struct *task = get_proc_task(dir); 1785 unsigned fd = name_to_int(dentry); 1786 struct dentry *result = ERR_PTR(-ENOENT); 1787 1788 if (!task) 1789 goto out_no_task; 1790 if (fd == ~0U) 1791 goto out; 1792 1793 result = instantiate(dir, dentry, task, &fd); 1794 out: 1795 put_task_struct(task); 1796 out_no_task: 1797 return result; 1798 } 1799 1800 static int proc_readfd_common(struct file * filp, void * dirent, 1801 filldir_t filldir, instantiate_t instantiate) 1802 { 1803 struct dentry *dentry = filp->f_path.dentry; 1804 struct inode *inode = dentry->d_inode; 1805 struct task_struct *p = get_proc_task(inode); 1806 unsigned int fd, ino; 1807 int retval; 1808 struct files_struct * files; 1809 1810 retval = -ENOENT; 1811 if (!p) 1812 goto out_no_task; 1813 retval = 0; 1814 1815 fd = filp->f_pos; 1816 switch (fd) { 1817 case 0: 1818 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 1819 goto out; 1820 filp->f_pos++; 1821 case 1: 1822 ino = parent_ino(dentry); 1823 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 1824 goto out; 1825 filp->f_pos++; 1826 default: 1827 files = get_files_struct(p); 1828 if (!files) 1829 goto out; 1830 rcu_read_lock(); 1831 for (fd = filp->f_pos-2; 1832 fd < files_fdtable(files)->max_fds; 1833 fd++, filp->f_pos++) { 1834 char name[PROC_NUMBUF]; 1835 int len; 1836 1837 if (!fcheck_files(files, fd)) 1838 continue; 1839 rcu_read_unlock(); 1840 1841 len = snprintf(name, sizeof(name), "%d", fd); 1842 if (proc_fill_cache(filp, dirent, filldir, 1843 name, len, instantiate, 1844 p, &fd) < 0) { 1845 rcu_read_lock(); 1846 break; 1847 } 1848 rcu_read_lock(); 1849 } 1850 rcu_read_unlock(); 1851 put_files_struct(files); 1852 } 1853 out: 1854 put_task_struct(p); 1855 out_no_task: 1856 return retval; 1857 } 1858 1859 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 1860 struct nameidata *nd) 1861 { 1862 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 1863 } 1864 1865 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 1866 { 1867 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 1868 } 1869 1870 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 1871 size_t len, loff_t *ppos) 1872 { 1873 char tmp[PROC_FDINFO_MAX]; 1874 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); 1875 if (!err) 1876 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 1877 return err; 1878 } 1879 1880 static const struct file_operations proc_fdinfo_file_operations = { 1881 .open = nonseekable_open, 1882 .read = proc_fdinfo_read, 1883 }; 1884 1885 static const struct file_operations proc_fd_operations = { 1886 .read = generic_read_dir, 1887 .readdir = proc_readfd, 1888 }; 1889 1890 /* 1891 * /proc/pid/fd needs a special permission handler so that a process can still 1892 * access /proc/self/fd after it has executed a setuid(). 1893 */ 1894 static int proc_fd_permission(struct inode *inode, int mask) 1895 { 1896 int rv; 1897 1898 rv = generic_permission(inode, mask, NULL); 1899 if (rv == 0) 1900 return 0; 1901 if (task_pid(current) == proc_pid(inode)) 1902 rv = 0; 1903 return rv; 1904 } 1905 1906 /* 1907 * proc directories can do almost nothing.. 1908 */ 1909 static const struct inode_operations proc_fd_inode_operations = { 1910 .lookup = proc_lookupfd, 1911 .permission = proc_fd_permission, 1912 .setattr = proc_setattr, 1913 }; 1914 1915 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 1916 struct dentry *dentry, struct task_struct *task, const void *ptr) 1917 { 1918 unsigned fd = *(unsigned *)ptr; 1919 struct inode *inode; 1920 struct proc_inode *ei; 1921 struct dentry *error = ERR_PTR(-ENOENT); 1922 1923 inode = proc_pid_make_inode(dir->i_sb, task); 1924 if (!inode) 1925 goto out; 1926 ei = PROC_I(inode); 1927 ei->fd = fd; 1928 inode->i_mode = S_IFREG | S_IRUSR; 1929 inode->i_fop = &proc_fdinfo_file_operations; 1930 dentry->d_op = &tid_fd_dentry_operations; 1931 d_add(dentry, inode); 1932 /* Close the race of the process dying before we return the dentry */ 1933 if (tid_fd_revalidate(dentry, NULL)) 1934 error = NULL; 1935 1936 out: 1937 return error; 1938 } 1939 1940 static struct dentry *proc_lookupfdinfo(struct inode *dir, 1941 struct dentry *dentry, 1942 struct nameidata *nd) 1943 { 1944 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 1945 } 1946 1947 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 1948 { 1949 return proc_readfd_common(filp, dirent, filldir, 1950 proc_fdinfo_instantiate); 1951 } 1952 1953 static const struct file_operations proc_fdinfo_operations = { 1954 .read = generic_read_dir, 1955 .readdir = proc_readfdinfo, 1956 }; 1957 1958 /* 1959 * proc directories can do almost nothing.. 1960 */ 1961 static const struct inode_operations proc_fdinfo_inode_operations = { 1962 .lookup = proc_lookupfdinfo, 1963 .setattr = proc_setattr, 1964 }; 1965 1966 1967 static struct dentry *proc_pident_instantiate(struct inode *dir, 1968 struct dentry *dentry, struct task_struct *task, const void *ptr) 1969 { 1970 const struct pid_entry *p = ptr; 1971 struct inode *inode; 1972 struct proc_inode *ei; 1973 struct dentry *error = ERR_PTR(-ENOENT); 1974 1975 inode = proc_pid_make_inode(dir->i_sb, task); 1976 if (!inode) 1977 goto out; 1978 1979 ei = PROC_I(inode); 1980 inode->i_mode = p->mode; 1981 if (S_ISDIR(inode->i_mode)) 1982 inode->i_nlink = 2; /* Use getattr to fix if necessary */ 1983 if (p->iop) 1984 inode->i_op = p->iop; 1985 if (p->fop) 1986 inode->i_fop = p->fop; 1987 ei->op = p->op; 1988 dentry->d_op = &pid_dentry_operations; 1989 d_add(dentry, inode); 1990 /* Close the race of the process dying before we return the dentry */ 1991 if (pid_revalidate(dentry, NULL)) 1992 error = NULL; 1993 out: 1994 return error; 1995 } 1996 1997 static struct dentry *proc_pident_lookup(struct inode *dir, 1998 struct dentry *dentry, 1999 const struct pid_entry *ents, 2000 unsigned int nents) 2001 { 2002 struct dentry *error; 2003 struct task_struct *task = get_proc_task(dir); 2004 const struct pid_entry *p, *last; 2005 2006 error = ERR_PTR(-ENOENT); 2007 2008 if (!task) 2009 goto out_no_task; 2010 2011 /* 2012 * Yes, it does not scale. And it should not. Don't add 2013 * new entries into /proc/<tgid>/ without very good reasons. 2014 */ 2015 last = &ents[nents - 1]; 2016 for (p = ents; p <= last; p++) { 2017 if (p->len != dentry->d_name.len) 2018 continue; 2019 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2020 break; 2021 } 2022 if (p > last) 2023 goto out; 2024 2025 error = proc_pident_instantiate(dir, dentry, task, p); 2026 out: 2027 put_task_struct(task); 2028 out_no_task: 2029 return error; 2030 } 2031 2032 static int proc_pident_fill_cache(struct file *filp, void *dirent, 2033 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2034 { 2035 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2036 proc_pident_instantiate, task, p); 2037 } 2038 2039 static int proc_pident_readdir(struct file *filp, 2040 void *dirent, filldir_t filldir, 2041 const struct pid_entry *ents, unsigned int nents) 2042 { 2043 int i; 2044 struct dentry *dentry = filp->f_path.dentry; 2045 struct inode *inode = dentry->d_inode; 2046 struct task_struct *task = get_proc_task(inode); 2047 const struct pid_entry *p, *last; 2048 ino_t ino; 2049 int ret; 2050 2051 ret = -ENOENT; 2052 if (!task) 2053 goto out_no_task; 2054 2055 ret = 0; 2056 i = filp->f_pos; 2057 switch (i) { 2058 case 0: 2059 ino = inode->i_ino; 2060 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 2061 goto out; 2062 i++; 2063 filp->f_pos++; 2064 /* fall through */ 2065 case 1: 2066 ino = parent_ino(dentry); 2067 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 2068 goto out; 2069 i++; 2070 filp->f_pos++; 2071 /* fall through */ 2072 default: 2073 i -= 2; 2074 if (i >= nents) { 2075 ret = 1; 2076 goto out; 2077 } 2078 p = ents + i; 2079 last = &ents[nents - 1]; 2080 while (p <= last) { 2081 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2082 goto out; 2083 filp->f_pos++; 2084 p++; 2085 } 2086 } 2087 2088 ret = 1; 2089 out: 2090 put_task_struct(task); 2091 out_no_task: 2092 return ret; 2093 } 2094 2095 #ifdef CONFIG_SECURITY 2096 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2097 size_t count, loff_t *ppos) 2098 { 2099 struct inode * inode = file->f_path.dentry->d_inode; 2100 char *p = NULL; 2101 ssize_t length; 2102 struct task_struct *task = get_proc_task(inode); 2103 2104 if (!task) 2105 return -ESRCH; 2106 2107 length = security_getprocattr(task, 2108 (char*)file->f_path.dentry->d_name.name, 2109 &p); 2110 put_task_struct(task); 2111 if (length > 0) 2112 length = simple_read_from_buffer(buf, count, ppos, p, length); 2113 kfree(p); 2114 return length; 2115 } 2116 2117 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2118 size_t count, loff_t *ppos) 2119 { 2120 struct inode * inode = file->f_path.dentry->d_inode; 2121 char *page; 2122 ssize_t length; 2123 struct task_struct *task = get_proc_task(inode); 2124 2125 length = -ESRCH; 2126 if (!task) 2127 goto out_no_task; 2128 if (count > PAGE_SIZE) 2129 count = PAGE_SIZE; 2130 2131 /* No partial writes. */ 2132 length = -EINVAL; 2133 if (*ppos != 0) 2134 goto out; 2135 2136 length = -ENOMEM; 2137 page = (char*)__get_free_page(GFP_TEMPORARY); 2138 if (!page) 2139 goto out; 2140 2141 length = -EFAULT; 2142 if (copy_from_user(page, buf, count)) 2143 goto out_free; 2144 2145 /* Guard against adverse ptrace interaction */ 2146 length = mutex_lock_interruptible(&task->cred_guard_mutex); 2147 if (length < 0) 2148 goto out_free; 2149 2150 length = security_setprocattr(task, 2151 (char*)file->f_path.dentry->d_name.name, 2152 (void*)page, count); 2153 mutex_unlock(&task->cred_guard_mutex); 2154 out_free: 2155 free_page((unsigned long) page); 2156 out: 2157 put_task_struct(task); 2158 out_no_task: 2159 return length; 2160 } 2161 2162 static const struct file_operations proc_pid_attr_operations = { 2163 .read = proc_pid_attr_read, 2164 .write = proc_pid_attr_write, 2165 }; 2166 2167 static const struct pid_entry attr_dir_stuff[] = { 2168 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2169 REG("prev", S_IRUGO, proc_pid_attr_operations), 2170 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2171 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2172 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2173 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2174 }; 2175 2176 static int proc_attr_dir_readdir(struct file * filp, 2177 void * dirent, filldir_t filldir) 2178 { 2179 return proc_pident_readdir(filp,dirent,filldir, 2180 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2181 } 2182 2183 static const struct file_operations proc_attr_dir_operations = { 2184 .read = generic_read_dir, 2185 .readdir = proc_attr_dir_readdir, 2186 }; 2187 2188 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2189 struct dentry *dentry, struct nameidata *nd) 2190 { 2191 return proc_pident_lookup(dir, dentry, 2192 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2193 } 2194 2195 static const struct inode_operations proc_attr_dir_inode_operations = { 2196 .lookup = proc_attr_dir_lookup, 2197 .getattr = pid_getattr, 2198 .setattr = proc_setattr, 2199 }; 2200 2201 #endif 2202 2203 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2204 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2205 size_t count, loff_t *ppos) 2206 { 2207 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2208 struct mm_struct *mm; 2209 char buffer[PROC_NUMBUF]; 2210 size_t len; 2211 int ret; 2212 2213 if (!task) 2214 return -ESRCH; 2215 2216 ret = 0; 2217 mm = get_task_mm(task); 2218 if (mm) { 2219 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2220 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2221 MMF_DUMP_FILTER_SHIFT)); 2222 mmput(mm); 2223 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2224 } 2225 2226 put_task_struct(task); 2227 2228 return ret; 2229 } 2230 2231 static ssize_t proc_coredump_filter_write(struct file *file, 2232 const char __user *buf, 2233 size_t count, 2234 loff_t *ppos) 2235 { 2236 struct task_struct *task; 2237 struct mm_struct *mm; 2238 char buffer[PROC_NUMBUF], *end; 2239 unsigned int val; 2240 int ret; 2241 int i; 2242 unsigned long mask; 2243 2244 ret = -EFAULT; 2245 memset(buffer, 0, sizeof(buffer)); 2246 if (count > sizeof(buffer) - 1) 2247 count = sizeof(buffer) - 1; 2248 if (copy_from_user(buffer, buf, count)) 2249 goto out_no_task; 2250 2251 ret = -EINVAL; 2252 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2253 if (*end == '\n') 2254 end++; 2255 if (end - buffer == 0) 2256 goto out_no_task; 2257 2258 ret = -ESRCH; 2259 task = get_proc_task(file->f_dentry->d_inode); 2260 if (!task) 2261 goto out_no_task; 2262 2263 ret = end - buffer; 2264 mm = get_task_mm(task); 2265 if (!mm) 2266 goto out_no_mm; 2267 2268 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2269 if (val & mask) 2270 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2271 else 2272 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2273 } 2274 2275 mmput(mm); 2276 out_no_mm: 2277 put_task_struct(task); 2278 out_no_task: 2279 return ret; 2280 } 2281 2282 static const struct file_operations proc_coredump_filter_operations = { 2283 .read = proc_coredump_filter_read, 2284 .write = proc_coredump_filter_write, 2285 }; 2286 #endif 2287 2288 /* 2289 * /proc/self: 2290 */ 2291 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2292 int buflen) 2293 { 2294 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2295 pid_t tgid = task_tgid_nr_ns(current, ns); 2296 char tmp[PROC_NUMBUF]; 2297 if (!tgid) 2298 return -ENOENT; 2299 sprintf(tmp, "%d", tgid); 2300 return vfs_readlink(dentry,buffer,buflen,tmp); 2301 } 2302 2303 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2304 { 2305 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2306 pid_t tgid = task_tgid_nr_ns(current, ns); 2307 char tmp[PROC_NUMBUF]; 2308 if (!tgid) 2309 return ERR_PTR(-ENOENT); 2310 sprintf(tmp, "%d", task_tgid_nr_ns(current, ns)); 2311 return ERR_PTR(vfs_follow_link(nd,tmp)); 2312 } 2313 2314 static const struct inode_operations proc_self_inode_operations = { 2315 .readlink = proc_self_readlink, 2316 .follow_link = proc_self_follow_link, 2317 }; 2318 2319 /* 2320 * proc base 2321 * 2322 * These are the directory entries in the root directory of /proc 2323 * that properly belong to the /proc filesystem, as they describe 2324 * describe something that is process related. 2325 */ 2326 static const struct pid_entry proc_base_stuff[] = { 2327 NOD("self", S_IFLNK|S_IRWXUGO, 2328 &proc_self_inode_operations, NULL, {}), 2329 }; 2330 2331 /* 2332 * Exceptional case: normally we are not allowed to unhash a busy 2333 * directory. In this case, however, we can do it - no aliasing problems 2334 * due to the way we treat inodes. 2335 */ 2336 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) 2337 { 2338 struct inode *inode = dentry->d_inode; 2339 struct task_struct *task = get_proc_task(inode); 2340 if (task) { 2341 put_task_struct(task); 2342 return 1; 2343 } 2344 d_drop(dentry); 2345 return 0; 2346 } 2347 2348 static const struct dentry_operations proc_base_dentry_operations = 2349 { 2350 .d_revalidate = proc_base_revalidate, 2351 .d_delete = pid_delete_dentry, 2352 }; 2353 2354 static struct dentry *proc_base_instantiate(struct inode *dir, 2355 struct dentry *dentry, struct task_struct *task, const void *ptr) 2356 { 2357 const struct pid_entry *p = ptr; 2358 struct inode *inode; 2359 struct proc_inode *ei; 2360 struct dentry *error = ERR_PTR(-EINVAL); 2361 2362 /* Allocate the inode */ 2363 error = ERR_PTR(-ENOMEM); 2364 inode = new_inode(dir->i_sb); 2365 if (!inode) 2366 goto out; 2367 2368 /* Initialize the inode */ 2369 ei = PROC_I(inode); 2370 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2371 2372 /* 2373 * grab the reference to the task. 2374 */ 2375 ei->pid = get_task_pid(task, PIDTYPE_PID); 2376 if (!ei->pid) 2377 goto out_iput; 2378 2379 inode->i_mode = p->mode; 2380 if (S_ISDIR(inode->i_mode)) 2381 inode->i_nlink = 2; 2382 if (S_ISLNK(inode->i_mode)) 2383 inode->i_size = 64; 2384 if (p->iop) 2385 inode->i_op = p->iop; 2386 if (p->fop) 2387 inode->i_fop = p->fop; 2388 ei->op = p->op; 2389 dentry->d_op = &proc_base_dentry_operations; 2390 d_add(dentry, inode); 2391 error = NULL; 2392 out: 2393 return error; 2394 out_iput: 2395 iput(inode); 2396 goto out; 2397 } 2398 2399 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2400 { 2401 struct dentry *error; 2402 struct task_struct *task = get_proc_task(dir); 2403 const struct pid_entry *p, *last; 2404 2405 error = ERR_PTR(-ENOENT); 2406 2407 if (!task) 2408 goto out_no_task; 2409 2410 /* Lookup the directory entry */ 2411 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2412 for (p = proc_base_stuff; p <= last; p++) { 2413 if (p->len != dentry->d_name.len) 2414 continue; 2415 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2416 break; 2417 } 2418 if (p > last) 2419 goto out; 2420 2421 error = proc_base_instantiate(dir, dentry, task, p); 2422 2423 out: 2424 put_task_struct(task); 2425 out_no_task: 2426 return error; 2427 } 2428 2429 static int proc_base_fill_cache(struct file *filp, void *dirent, 2430 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2431 { 2432 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2433 proc_base_instantiate, task, p); 2434 } 2435 2436 #ifdef CONFIG_TASK_IO_ACCOUNTING 2437 static int do_io_accounting(struct task_struct *task, char *buffer, int whole) 2438 { 2439 struct task_io_accounting acct = task->ioac; 2440 unsigned long flags; 2441 2442 if (whole && lock_task_sighand(task, &flags)) { 2443 struct task_struct *t = task; 2444 2445 task_io_accounting_add(&acct, &task->signal->ioac); 2446 while_each_thread(task, t) 2447 task_io_accounting_add(&acct, &t->ioac); 2448 2449 unlock_task_sighand(task, &flags); 2450 } 2451 return sprintf(buffer, 2452 "rchar: %llu\n" 2453 "wchar: %llu\n" 2454 "syscr: %llu\n" 2455 "syscw: %llu\n" 2456 "read_bytes: %llu\n" 2457 "write_bytes: %llu\n" 2458 "cancelled_write_bytes: %llu\n", 2459 (unsigned long long)acct.rchar, 2460 (unsigned long long)acct.wchar, 2461 (unsigned long long)acct.syscr, 2462 (unsigned long long)acct.syscw, 2463 (unsigned long long)acct.read_bytes, 2464 (unsigned long long)acct.write_bytes, 2465 (unsigned long long)acct.cancelled_write_bytes); 2466 } 2467 2468 static int proc_tid_io_accounting(struct task_struct *task, char *buffer) 2469 { 2470 return do_io_accounting(task, buffer, 0); 2471 } 2472 2473 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer) 2474 { 2475 return do_io_accounting(task, buffer, 1); 2476 } 2477 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2478 2479 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2480 struct pid *pid, struct task_struct *task) 2481 { 2482 seq_printf(m, "%08x\n", task->personality); 2483 return 0; 2484 } 2485 2486 /* 2487 * Thread groups 2488 */ 2489 static const struct file_operations proc_task_operations; 2490 static const struct inode_operations proc_task_inode_operations; 2491 2492 static const struct pid_entry tgid_base_stuff[] = { 2493 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2494 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2495 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2496 #ifdef CONFIG_NET 2497 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2498 #endif 2499 REG("environ", S_IRUSR, proc_environ_operations), 2500 INF("auxv", S_IRUSR, proc_pid_auxv), 2501 ONE("status", S_IRUGO, proc_pid_status), 2502 ONE("personality", S_IRUSR, proc_pid_personality), 2503 INF("limits", S_IRUSR, proc_pid_limits), 2504 #ifdef CONFIG_SCHED_DEBUG 2505 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2506 #endif 2507 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2508 INF("syscall", S_IRUSR, proc_pid_syscall), 2509 #endif 2510 INF("cmdline", S_IRUGO, proc_pid_cmdline), 2511 ONE("stat", S_IRUGO, proc_tgid_stat), 2512 ONE("statm", S_IRUGO, proc_pid_statm), 2513 REG("maps", S_IRUGO, proc_maps_operations), 2514 #ifdef CONFIG_NUMA 2515 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 2516 #endif 2517 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2518 LNK("cwd", proc_cwd_link), 2519 LNK("root", proc_root_link), 2520 LNK("exe", proc_exe_link), 2521 REG("mounts", S_IRUGO, proc_mounts_operations), 2522 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2523 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2524 #ifdef CONFIG_PROC_PAGE_MONITOR 2525 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2526 REG("smaps", S_IRUGO, proc_smaps_operations), 2527 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2528 #endif 2529 #ifdef CONFIG_SECURITY 2530 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2531 #endif 2532 #ifdef CONFIG_KALLSYMS 2533 INF("wchan", S_IRUGO, proc_pid_wchan), 2534 #endif 2535 #ifdef CONFIG_STACKTRACE 2536 ONE("stack", S_IRUSR, proc_pid_stack), 2537 #endif 2538 #ifdef CONFIG_SCHEDSTATS 2539 INF("schedstat", S_IRUGO, proc_pid_schedstat), 2540 #endif 2541 #ifdef CONFIG_LATENCYTOP 2542 REG("latency", S_IRUGO, proc_lstats_operations), 2543 #endif 2544 #ifdef CONFIG_PROC_PID_CPUSET 2545 REG("cpuset", S_IRUGO, proc_cpuset_operations), 2546 #endif 2547 #ifdef CONFIG_CGROUPS 2548 REG("cgroup", S_IRUGO, proc_cgroup_operations), 2549 #endif 2550 INF("oom_score", S_IRUGO, proc_oom_score), 2551 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 2552 #ifdef CONFIG_AUDITSYSCALL 2553 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2554 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2555 #endif 2556 #ifdef CONFIG_FAULT_INJECTION 2557 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2558 #endif 2559 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2560 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2561 #endif 2562 #ifdef CONFIG_TASK_IO_ACCOUNTING 2563 INF("io", S_IRUGO, proc_tgid_io_accounting), 2564 #endif 2565 }; 2566 2567 static int proc_tgid_base_readdir(struct file * filp, 2568 void * dirent, filldir_t filldir) 2569 { 2570 return proc_pident_readdir(filp,dirent,filldir, 2571 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2572 } 2573 2574 static const struct file_operations proc_tgid_base_operations = { 2575 .read = generic_read_dir, 2576 .readdir = proc_tgid_base_readdir, 2577 }; 2578 2579 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2580 return proc_pident_lookup(dir, dentry, 2581 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2582 } 2583 2584 static const struct inode_operations proc_tgid_base_inode_operations = { 2585 .lookup = proc_tgid_base_lookup, 2586 .getattr = pid_getattr, 2587 .setattr = proc_setattr, 2588 }; 2589 2590 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2591 { 2592 struct dentry *dentry, *leader, *dir; 2593 char buf[PROC_NUMBUF]; 2594 struct qstr name; 2595 2596 name.name = buf; 2597 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2598 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2599 if (dentry) { 2600 if (!(current->flags & PF_EXITING)) 2601 shrink_dcache_parent(dentry); 2602 d_drop(dentry); 2603 dput(dentry); 2604 } 2605 2606 name.name = buf; 2607 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2608 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2609 if (!leader) 2610 goto out; 2611 2612 name.name = "task"; 2613 name.len = strlen(name.name); 2614 dir = d_hash_and_lookup(leader, &name); 2615 if (!dir) 2616 goto out_put_leader; 2617 2618 name.name = buf; 2619 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2620 dentry = d_hash_and_lookup(dir, &name); 2621 if (dentry) { 2622 shrink_dcache_parent(dentry); 2623 d_drop(dentry); 2624 dput(dentry); 2625 } 2626 2627 dput(dir); 2628 out_put_leader: 2629 dput(leader); 2630 out: 2631 return; 2632 } 2633 2634 /** 2635 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2636 * @task: task that should be flushed. 2637 * 2638 * When flushing dentries from proc, one needs to flush them from global 2639 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2640 * in. This call is supposed to do all of this job. 2641 * 2642 * Looks in the dcache for 2643 * /proc/@pid 2644 * /proc/@tgid/task/@pid 2645 * if either directory is present flushes it and all of it'ts children 2646 * from the dcache. 2647 * 2648 * It is safe and reasonable to cache /proc entries for a task until 2649 * that task exits. After that they just clog up the dcache with 2650 * useless entries, possibly causing useful dcache entries to be 2651 * flushed instead. This routine is proved to flush those useless 2652 * dcache entries at process exit time. 2653 * 2654 * NOTE: This routine is just an optimization so it does not guarantee 2655 * that no dcache entries will exist at process exit time it 2656 * just makes it very unlikely that any will persist. 2657 */ 2658 2659 void proc_flush_task(struct task_struct *task) 2660 { 2661 int i; 2662 struct pid *pid, *tgid; 2663 struct upid *upid; 2664 2665 pid = task_pid(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->numbers[i].nr); 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