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