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/init.h> 57 #include <linux/capability.h> 58 #include <linux/file.h> 59 #include <linux/string.h> 60 #include <linux/seq_file.h> 61 #include <linux/namei.h> 62 #include <linux/mnt_namespace.h> 63 #include <linux/mm.h> 64 #include <linux/rcupdate.h> 65 #include <linux/kallsyms.h> 66 #include <linux/resource.h> 67 #include <linux/module.h> 68 #include <linux/mount.h> 69 #include <linux/security.h> 70 #include <linux/ptrace.h> 71 #include <linux/cgroup.h> 72 #include <linux/cpuset.h> 73 #include <linux/audit.h> 74 #include <linux/poll.h> 75 #include <linux/nsproxy.h> 76 #include <linux/oom.h> 77 #include <linux/elf.h> 78 #include <linux/pid_namespace.h> 79 #include "internal.h" 80 81 /* NOTE: 82 * Implementing inode permission operations in /proc is almost 83 * certainly an error. Permission checks need to happen during 84 * each system call not at open time. The reason is that most of 85 * what we wish to check for permissions in /proc varies at runtime. 86 * 87 * The classic example of a problem is opening file descriptors 88 * in /proc for a task before it execs a suid executable. 89 */ 90 91 struct pid_entry { 92 char *name; 93 int len; 94 mode_t mode; 95 const struct inode_operations *iop; 96 const struct file_operations *fop; 97 union proc_op op; 98 }; 99 100 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 101 .name = (NAME), \ 102 .len = sizeof(NAME) - 1, \ 103 .mode = MODE, \ 104 .iop = IOP, \ 105 .fop = FOP, \ 106 .op = OP, \ 107 } 108 109 #define DIR(NAME, MODE, OTYPE) \ 110 NOD(NAME, (S_IFDIR|(MODE)), \ 111 &proc_##OTYPE##_inode_operations, &proc_##OTYPE##_operations, \ 112 {} ) 113 #define LNK(NAME, OTYPE) \ 114 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 115 &proc_pid_link_inode_operations, NULL, \ 116 { .proc_get_link = &proc_##OTYPE##_link } ) 117 #define REG(NAME, MODE, OTYPE) \ 118 NOD(NAME, (S_IFREG|(MODE)), NULL, \ 119 &proc_##OTYPE##_operations, {}) 120 #define INF(NAME, MODE, OTYPE) \ 121 NOD(NAME, (S_IFREG|(MODE)), \ 122 NULL, &proc_info_file_operations, \ 123 { .proc_read = &proc_##OTYPE } ) 124 #define ONE(NAME, MODE, OTYPE) \ 125 NOD(NAME, (S_IFREG|(MODE)), \ 126 NULL, &proc_single_file_operations, \ 127 { .proc_show = &proc_##OTYPE } ) 128 129 int maps_protect; 130 EXPORT_SYMBOL(maps_protect); 131 132 static struct fs_struct *get_fs_struct(struct task_struct *task) 133 { 134 struct fs_struct *fs; 135 task_lock(task); 136 fs = task->fs; 137 if(fs) 138 atomic_inc(&fs->count); 139 task_unlock(task); 140 return fs; 141 } 142 143 static int get_nr_threads(struct task_struct *tsk) 144 { 145 /* Must be called with the rcu_read_lock held */ 146 unsigned long flags; 147 int count = 0; 148 149 if (lock_task_sighand(tsk, &flags)) { 150 count = atomic_read(&tsk->signal->count); 151 unlock_task_sighand(tsk, &flags); 152 } 153 return count; 154 } 155 156 static int proc_cwd_link(struct inode *inode, struct path *path) 157 { 158 struct task_struct *task = get_proc_task(inode); 159 struct fs_struct *fs = NULL; 160 int result = -ENOENT; 161 162 if (task) { 163 fs = get_fs_struct(task); 164 put_task_struct(task); 165 } 166 if (fs) { 167 read_lock(&fs->lock); 168 *path = fs->pwd; 169 path_get(&fs->pwd); 170 read_unlock(&fs->lock); 171 result = 0; 172 put_fs_struct(fs); 173 } 174 return result; 175 } 176 177 static int proc_root_link(struct inode *inode, struct path *path) 178 { 179 struct task_struct *task = get_proc_task(inode); 180 struct fs_struct *fs = NULL; 181 int result = -ENOENT; 182 183 if (task) { 184 fs = get_fs_struct(task); 185 put_task_struct(task); 186 } 187 if (fs) { 188 read_lock(&fs->lock); 189 *path = fs->root; 190 path_get(&fs->root); 191 read_unlock(&fs->lock); 192 result = 0; 193 put_fs_struct(fs); 194 } 195 return result; 196 } 197 198 /* 199 * Return zero if current may access user memory in @task, -error if not. 200 */ 201 static int check_mem_permission(struct task_struct *task) 202 { 203 /* 204 * A task can always look at itself, in case it chooses 205 * to use system calls instead of load instructions. 206 */ 207 if (task == current) 208 return 0; 209 210 /* 211 * If current is actively ptrace'ing, and would also be 212 * permitted to freshly attach with ptrace now, permit it. 213 */ 214 if (task->parent == current && (task->ptrace & PT_PTRACED) && 215 task_is_stopped_or_traced(task) && 216 ptrace_may_attach(task)) 217 return 0; 218 219 /* 220 * Noone else is allowed. 221 */ 222 return -EPERM; 223 } 224 225 struct mm_struct *mm_for_maps(struct task_struct *task) 226 { 227 struct mm_struct *mm = get_task_mm(task); 228 if (!mm) 229 return NULL; 230 down_read(&mm->mmap_sem); 231 task_lock(task); 232 if (task->mm != mm) 233 goto out; 234 if (task->mm != current->mm && __ptrace_may_attach(task) < 0) 235 goto out; 236 task_unlock(task); 237 return mm; 238 out: 239 task_unlock(task); 240 up_read(&mm->mmap_sem); 241 mmput(mm); 242 return NULL; 243 } 244 245 static int proc_pid_cmdline(struct task_struct *task, char * buffer) 246 { 247 int res = 0; 248 unsigned int len; 249 struct mm_struct *mm = get_task_mm(task); 250 if (!mm) 251 goto out; 252 if (!mm->arg_end) 253 goto out_mm; /* Shh! No looking before we're done */ 254 255 len = mm->arg_end - mm->arg_start; 256 257 if (len > PAGE_SIZE) 258 len = PAGE_SIZE; 259 260 res = access_process_vm(task, mm->arg_start, buffer, len, 0); 261 262 // If the nul at the end of args has been overwritten, then 263 // assume application is using setproctitle(3). 264 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) { 265 len = strnlen(buffer, res); 266 if (len < res) { 267 res = len; 268 } else { 269 len = mm->env_end - mm->env_start; 270 if (len > PAGE_SIZE - res) 271 len = PAGE_SIZE - res; 272 res += access_process_vm(task, mm->env_start, buffer+res, len, 0); 273 res = strnlen(buffer, res); 274 } 275 } 276 out_mm: 277 mmput(mm); 278 out: 279 return res; 280 } 281 282 static int proc_pid_auxv(struct task_struct *task, char *buffer) 283 { 284 int res = 0; 285 struct mm_struct *mm = get_task_mm(task); 286 if (mm) { 287 unsigned int nwords = 0; 288 do 289 nwords += 2; 290 while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 291 res = nwords * sizeof(mm->saved_auxv[0]); 292 if (res > PAGE_SIZE) 293 res = PAGE_SIZE; 294 memcpy(buffer, mm->saved_auxv, res); 295 mmput(mm); 296 } 297 return res; 298 } 299 300 301 #ifdef CONFIG_KALLSYMS 302 /* 303 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 304 * Returns the resolved symbol. If that fails, simply return the address. 305 */ 306 static int proc_pid_wchan(struct task_struct *task, char *buffer) 307 { 308 unsigned long wchan; 309 char symname[KSYM_NAME_LEN]; 310 311 wchan = get_wchan(task); 312 313 if (lookup_symbol_name(wchan, symname) < 0) 314 return sprintf(buffer, "%lu", wchan); 315 else 316 return sprintf(buffer, "%s", symname); 317 } 318 #endif /* CONFIG_KALLSYMS */ 319 320 #ifdef CONFIG_SCHEDSTATS 321 /* 322 * Provides /proc/PID/schedstat 323 */ 324 static int proc_pid_schedstat(struct task_struct *task, char *buffer) 325 { 326 return sprintf(buffer, "%llu %llu %lu\n", 327 task->sched_info.cpu_time, 328 task->sched_info.run_delay, 329 task->sched_info.pcount); 330 } 331 #endif 332 333 #ifdef CONFIG_LATENCYTOP 334 static int lstats_show_proc(struct seq_file *m, void *v) 335 { 336 int i; 337 struct inode *inode = m->private; 338 struct task_struct *task = get_proc_task(inode); 339 340 if (!task) 341 return -ESRCH; 342 seq_puts(m, "Latency Top version : v0.1\n"); 343 for (i = 0; i < 32; i++) { 344 if (task->latency_record[i].backtrace[0]) { 345 int q; 346 seq_printf(m, "%i %li %li ", 347 task->latency_record[i].count, 348 task->latency_record[i].time, 349 task->latency_record[i].max); 350 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 351 char sym[KSYM_NAME_LEN]; 352 char *c; 353 if (!task->latency_record[i].backtrace[q]) 354 break; 355 if (task->latency_record[i].backtrace[q] == ULONG_MAX) 356 break; 357 sprint_symbol(sym, task->latency_record[i].backtrace[q]); 358 c = strchr(sym, '+'); 359 if (c) 360 *c = 0; 361 seq_printf(m, "%s ", sym); 362 } 363 seq_printf(m, "\n"); 364 } 365 366 } 367 put_task_struct(task); 368 return 0; 369 } 370 371 static int lstats_open(struct inode *inode, struct file *file) 372 { 373 return single_open(file, lstats_show_proc, inode); 374 } 375 376 static ssize_t lstats_write(struct file *file, const char __user *buf, 377 size_t count, loff_t *offs) 378 { 379 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 380 381 if (!task) 382 return -ESRCH; 383 clear_all_latency_tracing(task); 384 put_task_struct(task); 385 386 return count; 387 } 388 389 static const struct file_operations proc_lstats_operations = { 390 .open = lstats_open, 391 .read = seq_read, 392 .write = lstats_write, 393 .llseek = seq_lseek, 394 .release = single_release, 395 }; 396 397 #endif 398 399 /* The badness from the OOM killer */ 400 unsigned long badness(struct task_struct *p, unsigned long uptime); 401 static int proc_oom_score(struct task_struct *task, char *buffer) 402 { 403 unsigned long points; 404 struct timespec uptime; 405 406 do_posix_clock_monotonic_gettime(&uptime); 407 read_lock(&tasklist_lock); 408 points = badness(task, uptime.tv_sec); 409 read_unlock(&tasklist_lock); 410 return sprintf(buffer, "%lu\n", points); 411 } 412 413 struct limit_names { 414 char *name; 415 char *unit; 416 }; 417 418 static const struct limit_names lnames[RLIM_NLIMITS] = { 419 [RLIMIT_CPU] = {"Max cpu time", "ms"}, 420 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 421 [RLIMIT_DATA] = {"Max data size", "bytes"}, 422 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 423 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 424 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 425 [RLIMIT_NPROC] = {"Max processes", "processes"}, 426 [RLIMIT_NOFILE] = {"Max open files", "files"}, 427 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 428 [RLIMIT_AS] = {"Max address space", "bytes"}, 429 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 430 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 431 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 432 [RLIMIT_NICE] = {"Max nice priority", NULL}, 433 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 434 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 435 }; 436 437 /* Display limits for a process */ 438 static int proc_pid_limits(struct task_struct *task, char *buffer) 439 { 440 unsigned int i; 441 int count = 0; 442 unsigned long flags; 443 char *bufptr = buffer; 444 445 struct rlimit rlim[RLIM_NLIMITS]; 446 447 rcu_read_lock(); 448 if (!lock_task_sighand(task,&flags)) { 449 rcu_read_unlock(); 450 return 0; 451 } 452 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 453 unlock_task_sighand(task, &flags); 454 rcu_read_unlock(); 455 456 /* 457 * print the file header 458 */ 459 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n", 460 "Limit", "Soft Limit", "Hard Limit", "Units"); 461 462 for (i = 0; i < RLIM_NLIMITS; i++) { 463 if (rlim[i].rlim_cur == RLIM_INFINITY) 464 count += sprintf(&bufptr[count], "%-25s %-20s ", 465 lnames[i].name, "unlimited"); 466 else 467 count += sprintf(&bufptr[count], "%-25s %-20lu ", 468 lnames[i].name, rlim[i].rlim_cur); 469 470 if (rlim[i].rlim_max == RLIM_INFINITY) 471 count += sprintf(&bufptr[count], "%-20s ", "unlimited"); 472 else 473 count += sprintf(&bufptr[count], "%-20lu ", 474 rlim[i].rlim_max); 475 476 if (lnames[i].unit) 477 count += sprintf(&bufptr[count], "%-10s\n", 478 lnames[i].unit); 479 else 480 count += sprintf(&bufptr[count], "\n"); 481 } 482 483 return count; 484 } 485 486 /************************************************************************/ 487 /* Here the fs part begins */ 488 /************************************************************************/ 489 490 /* permission checks */ 491 static int proc_fd_access_allowed(struct inode *inode) 492 { 493 struct task_struct *task; 494 int allowed = 0; 495 /* Allow access to a task's file descriptors if it is us or we 496 * may use ptrace attach to the process and find out that 497 * information. 498 */ 499 task = get_proc_task(inode); 500 if (task) { 501 allowed = ptrace_may_attach(task); 502 put_task_struct(task); 503 } 504 return allowed; 505 } 506 507 static int proc_setattr(struct dentry *dentry, struct iattr *attr) 508 { 509 int error; 510 struct inode *inode = dentry->d_inode; 511 512 if (attr->ia_valid & ATTR_MODE) 513 return -EPERM; 514 515 error = inode_change_ok(inode, attr); 516 if (!error) 517 error = inode_setattr(inode, attr); 518 return error; 519 } 520 521 static const struct inode_operations proc_def_inode_operations = { 522 .setattr = proc_setattr, 523 }; 524 525 static int mounts_open_common(struct inode *inode, struct file *file, 526 const struct seq_operations *op) 527 { 528 struct task_struct *task = get_proc_task(inode); 529 struct nsproxy *nsp; 530 struct mnt_namespace *ns = NULL; 531 struct fs_struct *fs = NULL; 532 struct path root; 533 struct proc_mounts *p; 534 int ret = -EINVAL; 535 536 if (task) { 537 rcu_read_lock(); 538 nsp = task_nsproxy(task); 539 if (nsp) { 540 ns = nsp->mnt_ns; 541 if (ns) 542 get_mnt_ns(ns); 543 } 544 rcu_read_unlock(); 545 if (ns) 546 fs = get_fs_struct(task); 547 put_task_struct(task); 548 } 549 550 if (!ns) 551 goto err; 552 if (!fs) 553 goto err_put_ns; 554 555 read_lock(&fs->lock); 556 root = fs->root; 557 path_get(&root); 558 read_unlock(&fs->lock); 559 put_fs_struct(fs); 560 561 ret = -ENOMEM; 562 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL); 563 if (!p) 564 goto err_put_path; 565 566 file->private_data = &p->m; 567 ret = seq_open(file, op); 568 if (ret) 569 goto err_free; 570 571 p->m.private = p; 572 p->ns = ns; 573 p->root = root; 574 p->event = ns->event; 575 576 return 0; 577 578 err_free: 579 kfree(p); 580 err_put_path: 581 path_put(&root); 582 err_put_ns: 583 put_mnt_ns(ns); 584 err: 585 return ret; 586 } 587 588 static int mounts_release(struct inode *inode, struct file *file) 589 { 590 struct proc_mounts *p = file->private_data; 591 path_put(&p->root); 592 put_mnt_ns(p->ns); 593 return seq_release(inode, file); 594 } 595 596 static unsigned mounts_poll(struct file *file, poll_table *wait) 597 { 598 struct proc_mounts *p = file->private_data; 599 struct mnt_namespace *ns = p->ns; 600 unsigned res = 0; 601 602 poll_wait(file, &ns->poll, wait); 603 604 spin_lock(&vfsmount_lock); 605 if (p->event != ns->event) { 606 p->event = ns->event; 607 res = POLLERR; 608 } 609 spin_unlock(&vfsmount_lock); 610 611 return res; 612 } 613 614 static int mounts_open(struct inode *inode, struct file *file) 615 { 616 return mounts_open_common(inode, file, &mounts_op); 617 } 618 619 static const struct file_operations proc_mounts_operations = { 620 .open = mounts_open, 621 .read = seq_read, 622 .llseek = seq_lseek, 623 .release = mounts_release, 624 .poll = mounts_poll, 625 }; 626 627 static int mountinfo_open(struct inode *inode, struct file *file) 628 { 629 return mounts_open_common(inode, file, &mountinfo_op); 630 } 631 632 static const struct file_operations proc_mountinfo_operations = { 633 .open = mountinfo_open, 634 .read = seq_read, 635 .llseek = seq_lseek, 636 .release = mounts_release, 637 .poll = mounts_poll, 638 }; 639 640 static int mountstats_open(struct inode *inode, struct file *file) 641 { 642 return mounts_open_common(inode, file, &mountstats_op); 643 } 644 645 static const struct file_operations proc_mountstats_operations = { 646 .open = mountstats_open, 647 .read = seq_read, 648 .llseek = seq_lseek, 649 .release = mounts_release, 650 }; 651 652 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */ 653 654 static ssize_t proc_info_read(struct file * file, char __user * buf, 655 size_t count, loff_t *ppos) 656 { 657 struct inode * inode = file->f_path.dentry->d_inode; 658 unsigned long page; 659 ssize_t length; 660 struct task_struct *task = get_proc_task(inode); 661 662 length = -ESRCH; 663 if (!task) 664 goto out_no_task; 665 666 if (count > PROC_BLOCK_SIZE) 667 count = PROC_BLOCK_SIZE; 668 669 length = -ENOMEM; 670 if (!(page = __get_free_page(GFP_TEMPORARY))) 671 goto out; 672 673 length = PROC_I(inode)->op.proc_read(task, (char*)page); 674 675 if (length >= 0) 676 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length); 677 free_page(page); 678 out: 679 put_task_struct(task); 680 out_no_task: 681 return length; 682 } 683 684 static const struct file_operations proc_info_file_operations = { 685 .read = proc_info_read, 686 }; 687 688 static int proc_single_show(struct seq_file *m, void *v) 689 { 690 struct inode *inode = m->private; 691 struct pid_namespace *ns; 692 struct pid *pid; 693 struct task_struct *task; 694 int ret; 695 696 ns = inode->i_sb->s_fs_info; 697 pid = proc_pid(inode); 698 task = get_pid_task(pid, PIDTYPE_PID); 699 if (!task) 700 return -ESRCH; 701 702 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 703 704 put_task_struct(task); 705 return ret; 706 } 707 708 static int proc_single_open(struct inode *inode, struct file *filp) 709 { 710 int ret; 711 ret = single_open(filp, proc_single_show, NULL); 712 if (!ret) { 713 struct seq_file *m = filp->private_data; 714 715 m->private = inode; 716 } 717 return ret; 718 } 719 720 static const struct file_operations proc_single_file_operations = { 721 .open = proc_single_open, 722 .read = seq_read, 723 .llseek = seq_lseek, 724 .release = single_release, 725 }; 726 727 static int mem_open(struct inode* inode, struct file* file) 728 { 729 file->private_data = (void*)((long)current->self_exec_id); 730 return 0; 731 } 732 733 static ssize_t mem_read(struct file * file, char __user * buf, 734 size_t count, loff_t *ppos) 735 { 736 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 737 char *page; 738 unsigned long src = *ppos; 739 int ret = -ESRCH; 740 struct mm_struct *mm; 741 742 if (!task) 743 goto out_no_task; 744 745 if (check_mem_permission(task)) 746 goto out; 747 748 ret = -ENOMEM; 749 page = (char *)__get_free_page(GFP_TEMPORARY); 750 if (!page) 751 goto out; 752 753 ret = 0; 754 755 mm = get_task_mm(task); 756 if (!mm) 757 goto out_free; 758 759 ret = -EIO; 760 761 if (file->private_data != (void*)((long)current->self_exec_id)) 762 goto out_put; 763 764 ret = 0; 765 766 while (count > 0) { 767 int this_len, retval; 768 769 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 770 retval = access_process_vm(task, src, page, this_len, 0); 771 if (!retval || check_mem_permission(task)) { 772 if (!ret) 773 ret = -EIO; 774 break; 775 } 776 777 if (copy_to_user(buf, page, retval)) { 778 ret = -EFAULT; 779 break; 780 } 781 782 ret += retval; 783 src += retval; 784 buf += retval; 785 count -= retval; 786 } 787 *ppos = src; 788 789 out_put: 790 mmput(mm); 791 out_free: 792 free_page((unsigned long) page); 793 out: 794 put_task_struct(task); 795 out_no_task: 796 return ret; 797 } 798 799 #define mem_write NULL 800 801 #ifndef mem_write 802 /* This is a security hazard */ 803 static ssize_t mem_write(struct file * file, const char __user *buf, 804 size_t count, loff_t *ppos) 805 { 806 int copied; 807 char *page; 808 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 809 unsigned long dst = *ppos; 810 811 copied = -ESRCH; 812 if (!task) 813 goto out_no_task; 814 815 if (check_mem_permission(task)) 816 goto out; 817 818 copied = -ENOMEM; 819 page = (char *)__get_free_page(GFP_TEMPORARY); 820 if (!page) 821 goto out; 822 823 copied = 0; 824 while (count > 0) { 825 int this_len, retval; 826 827 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 828 if (copy_from_user(page, buf, this_len)) { 829 copied = -EFAULT; 830 break; 831 } 832 retval = access_process_vm(task, dst, page, this_len, 1); 833 if (!retval) { 834 if (!copied) 835 copied = -EIO; 836 break; 837 } 838 copied += retval; 839 buf += retval; 840 dst += retval; 841 count -= retval; 842 } 843 *ppos = dst; 844 free_page((unsigned long) page); 845 out: 846 put_task_struct(task); 847 out_no_task: 848 return copied; 849 } 850 #endif 851 852 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 853 { 854 switch (orig) { 855 case 0: 856 file->f_pos = offset; 857 break; 858 case 1: 859 file->f_pos += offset; 860 break; 861 default: 862 return -EINVAL; 863 } 864 force_successful_syscall_return(); 865 return file->f_pos; 866 } 867 868 static const struct file_operations proc_mem_operations = { 869 .llseek = mem_lseek, 870 .read = mem_read, 871 .write = mem_write, 872 .open = mem_open, 873 }; 874 875 static ssize_t environ_read(struct file *file, char __user *buf, 876 size_t count, loff_t *ppos) 877 { 878 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 879 char *page; 880 unsigned long src = *ppos; 881 int ret = -ESRCH; 882 struct mm_struct *mm; 883 884 if (!task) 885 goto out_no_task; 886 887 if (!ptrace_may_attach(task)) 888 goto out; 889 890 ret = -ENOMEM; 891 page = (char *)__get_free_page(GFP_TEMPORARY); 892 if (!page) 893 goto out; 894 895 ret = 0; 896 897 mm = get_task_mm(task); 898 if (!mm) 899 goto out_free; 900 901 while (count > 0) { 902 int this_len, retval, max_len; 903 904 this_len = mm->env_end - (mm->env_start + src); 905 906 if (this_len <= 0) 907 break; 908 909 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 910 this_len = (this_len > max_len) ? max_len : this_len; 911 912 retval = access_process_vm(task, (mm->env_start + src), 913 page, this_len, 0); 914 915 if (retval <= 0) { 916 ret = retval; 917 break; 918 } 919 920 if (copy_to_user(buf, page, retval)) { 921 ret = -EFAULT; 922 break; 923 } 924 925 ret += retval; 926 src += retval; 927 buf += retval; 928 count -= retval; 929 } 930 *ppos = src; 931 932 mmput(mm); 933 out_free: 934 free_page((unsigned long) page); 935 out: 936 put_task_struct(task); 937 out_no_task: 938 return ret; 939 } 940 941 static const struct file_operations proc_environ_operations = { 942 .read = environ_read, 943 }; 944 945 static ssize_t oom_adjust_read(struct file *file, char __user *buf, 946 size_t count, loff_t *ppos) 947 { 948 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 949 char buffer[PROC_NUMBUF]; 950 size_t len; 951 int oom_adjust; 952 953 if (!task) 954 return -ESRCH; 955 oom_adjust = task->oomkilladj; 956 put_task_struct(task); 957 958 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); 959 960 return simple_read_from_buffer(buf, count, ppos, buffer, len); 961 } 962 963 static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 964 size_t count, loff_t *ppos) 965 { 966 struct task_struct *task; 967 char buffer[PROC_NUMBUF], *end; 968 int oom_adjust; 969 970 memset(buffer, 0, sizeof(buffer)); 971 if (count > sizeof(buffer) - 1) 972 count = sizeof(buffer) - 1; 973 if (copy_from_user(buffer, buf, count)) 974 return -EFAULT; 975 oom_adjust = simple_strtol(buffer, &end, 0); 976 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && 977 oom_adjust != OOM_DISABLE) 978 return -EINVAL; 979 if (*end == '\n') 980 end++; 981 task = get_proc_task(file->f_path.dentry->d_inode); 982 if (!task) 983 return -ESRCH; 984 if (oom_adjust < task->oomkilladj && !capable(CAP_SYS_RESOURCE)) { 985 put_task_struct(task); 986 return -EACCES; 987 } 988 task->oomkilladj = oom_adjust; 989 put_task_struct(task); 990 if (end - buffer == 0) 991 return -EIO; 992 return end - buffer; 993 } 994 995 static const struct file_operations proc_oom_adjust_operations = { 996 .read = oom_adjust_read, 997 .write = oom_adjust_write, 998 }; 999 1000 #ifdef CONFIG_AUDITSYSCALL 1001 #define TMPBUFLEN 21 1002 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1003 size_t count, loff_t *ppos) 1004 { 1005 struct inode * inode = file->f_path.dentry->d_inode; 1006 struct task_struct *task = get_proc_task(inode); 1007 ssize_t length; 1008 char tmpbuf[TMPBUFLEN]; 1009 1010 if (!task) 1011 return -ESRCH; 1012 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1013 audit_get_loginuid(task)); 1014 put_task_struct(task); 1015 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1016 } 1017 1018 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1019 size_t count, loff_t *ppos) 1020 { 1021 struct inode * inode = file->f_path.dentry->d_inode; 1022 char *page, *tmp; 1023 ssize_t length; 1024 uid_t loginuid; 1025 1026 if (!capable(CAP_AUDIT_CONTROL)) 1027 return -EPERM; 1028 1029 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) 1030 return -EPERM; 1031 1032 if (count >= PAGE_SIZE) 1033 count = PAGE_SIZE - 1; 1034 1035 if (*ppos != 0) { 1036 /* No partial writes. */ 1037 return -EINVAL; 1038 } 1039 page = (char*)__get_free_page(GFP_TEMPORARY); 1040 if (!page) 1041 return -ENOMEM; 1042 length = -EFAULT; 1043 if (copy_from_user(page, buf, count)) 1044 goto out_free_page; 1045 1046 page[count] = '\0'; 1047 loginuid = simple_strtoul(page, &tmp, 10); 1048 if (tmp == page) { 1049 length = -EINVAL; 1050 goto out_free_page; 1051 1052 } 1053 length = audit_set_loginuid(current, loginuid); 1054 if (likely(length == 0)) 1055 length = count; 1056 1057 out_free_page: 1058 free_page((unsigned long) page); 1059 return length; 1060 } 1061 1062 static const struct file_operations proc_loginuid_operations = { 1063 .read = proc_loginuid_read, 1064 .write = proc_loginuid_write, 1065 }; 1066 1067 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1068 size_t count, loff_t *ppos) 1069 { 1070 struct inode * inode = file->f_path.dentry->d_inode; 1071 struct task_struct *task = get_proc_task(inode); 1072 ssize_t length; 1073 char tmpbuf[TMPBUFLEN]; 1074 1075 if (!task) 1076 return -ESRCH; 1077 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1078 audit_get_sessionid(task)); 1079 put_task_struct(task); 1080 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1081 } 1082 1083 static const struct file_operations proc_sessionid_operations = { 1084 .read = proc_sessionid_read, 1085 }; 1086 #endif 1087 1088 #ifdef CONFIG_FAULT_INJECTION 1089 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1090 size_t count, loff_t *ppos) 1091 { 1092 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1093 char buffer[PROC_NUMBUF]; 1094 size_t len; 1095 int make_it_fail; 1096 1097 if (!task) 1098 return -ESRCH; 1099 make_it_fail = task->make_it_fail; 1100 put_task_struct(task); 1101 1102 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1103 1104 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1105 } 1106 1107 static ssize_t proc_fault_inject_write(struct file * file, 1108 const char __user * buf, size_t count, loff_t *ppos) 1109 { 1110 struct task_struct *task; 1111 char buffer[PROC_NUMBUF], *end; 1112 int make_it_fail; 1113 1114 if (!capable(CAP_SYS_RESOURCE)) 1115 return -EPERM; 1116 memset(buffer, 0, sizeof(buffer)); 1117 if (count > sizeof(buffer) - 1) 1118 count = sizeof(buffer) - 1; 1119 if (copy_from_user(buffer, buf, count)) 1120 return -EFAULT; 1121 make_it_fail = simple_strtol(buffer, &end, 0); 1122 if (*end == '\n') 1123 end++; 1124 task = get_proc_task(file->f_dentry->d_inode); 1125 if (!task) 1126 return -ESRCH; 1127 task->make_it_fail = make_it_fail; 1128 put_task_struct(task); 1129 if (end - buffer == 0) 1130 return -EIO; 1131 return end - buffer; 1132 } 1133 1134 static const struct file_operations proc_fault_inject_operations = { 1135 .read = proc_fault_inject_read, 1136 .write = proc_fault_inject_write, 1137 }; 1138 #endif 1139 1140 1141 #ifdef CONFIG_SCHED_DEBUG 1142 /* 1143 * Print out various scheduling related per-task fields: 1144 */ 1145 static int sched_show(struct seq_file *m, void *v) 1146 { 1147 struct inode *inode = m->private; 1148 struct task_struct *p; 1149 1150 WARN_ON(!inode); 1151 1152 p = get_proc_task(inode); 1153 if (!p) 1154 return -ESRCH; 1155 proc_sched_show_task(p, m); 1156 1157 put_task_struct(p); 1158 1159 return 0; 1160 } 1161 1162 static ssize_t 1163 sched_write(struct file *file, const char __user *buf, 1164 size_t count, loff_t *offset) 1165 { 1166 struct inode *inode = file->f_path.dentry->d_inode; 1167 struct task_struct *p; 1168 1169 WARN_ON(!inode); 1170 1171 p = get_proc_task(inode); 1172 if (!p) 1173 return -ESRCH; 1174 proc_sched_set_task(p); 1175 1176 put_task_struct(p); 1177 1178 return count; 1179 } 1180 1181 static int sched_open(struct inode *inode, struct file *filp) 1182 { 1183 int ret; 1184 1185 ret = single_open(filp, sched_show, NULL); 1186 if (!ret) { 1187 struct seq_file *m = filp->private_data; 1188 1189 m->private = inode; 1190 } 1191 return ret; 1192 } 1193 1194 static const struct file_operations proc_pid_sched_operations = { 1195 .open = sched_open, 1196 .read = seq_read, 1197 .write = sched_write, 1198 .llseek = seq_lseek, 1199 .release = single_release, 1200 }; 1201 1202 #endif 1203 1204 /* 1205 * We added or removed a vma mapping the executable. The vmas are only mapped 1206 * during exec and are not mapped with the mmap system call. 1207 * Callers must hold down_write() on the mm's mmap_sem for these 1208 */ 1209 void added_exe_file_vma(struct mm_struct *mm) 1210 { 1211 mm->num_exe_file_vmas++; 1212 } 1213 1214 void removed_exe_file_vma(struct mm_struct *mm) 1215 { 1216 mm->num_exe_file_vmas--; 1217 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){ 1218 fput(mm->exe_file); 1219 mm->exe_file = NULL; 1220 } 1221 1222 } 1223 1224 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) 1225 { 1226 if (new_exe_file) 1227 get_file(new_exe_file); 1228 if (mm->exe_file) 1229 fput(mm->exe_file); 1230 mm->exe_file = new_exe_file; 1231 mm->num_exe_file_vmas = 0; 1232 } 1233 1234 struct file *get_mm_exe_file(struct mm_struct *mm) 1235 { 1236 struct file *exe_file; 1237 1238 /* We need mmap_sem to protect against races with removal of 1239 * VM_EXECUTABLE vmas */ 1240 down_read(&mm->mmap_sem); 1241 exe_file = mm->exe_file; 1242 if (exe_file) 1243 get_file(exe_file); 1244 up_read(&mm->mmap_sem); 1245 return exe_file; 1246 } 1247 1248 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm) 1249 { 1250 /* It's safe to write the exe_file pointer without exe_file_lock because 1251 * this is called during fork when the task is not yet in /proc */ 1252 newmm->exe_file = get_mm_exe_file(oldmm); 1253 } 1254 1255 static int proc_exe_link(struct inode *inode, struct path *exe_path) 1256 { 1257 struct task_struct *task; 1258 struct mm_struct *mm; 1259 struct file *exe_file; 1260 1261 task = get_proc_task(inode); 1262 if (!task) 1263 return -ENOENT; 1264 mm = get_task_mm(task); 1265 put_task_struct(task); 1266 if (!mm) 1267 return -ENOENT; 1268 exe_file = get_mm_exe_file(mm); 1269 mmput(mm); 1270 if (exe_file) { 1271 *exe_path = exe_file->f_path; 1272 path_get(&exe_file->f_path); 1273 fput(exe_file); 1274 return 0; 1275 } else 1276 return -ENOENT; 1277 } 1278 1279 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1280 { 1281 struct inode *inode = dentry->d_inode; 1282 int error = -EACCES; 1283 1284 /* We don't need a base pointer in the /proc filesystem */ 1285 path_put(&nd->path); 1286 1287 /* Are we allowed to snoop on the tasks file descriptors? */ 1288 if (!proc_fd_access_allowed(inode)) 1289 goto out; 1290 1291 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path); 1292 nd->last_type = LAST_BIND; 1293 out: 1294 return ERR_PTR(error); 1295 } 1296 1297 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1298 { 1299 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1300 char *pathname; 1301 int len; 1302 1303 if (!tmp) 1304 return -ENOMEM; 1305 1306 pathname = d_path(path, tmp, PAGE_SIZE); 1307 len = PTR_ERR(pathname); 1308 if (IS_ERR(pathname)) 1309 goto out; 1310 len = tmp + PAGE_SIZE - 1 - pathname; 1311 1312 if (len > buflen) 1313 len = buflen; 1314 if (copy_to_user(buffer, pathname, len)) 1315 len = -EFAULT; 1316 out: 1317 free_page((unsigned long)tmp); 1318 return len; 1319 } 1320 1321 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1322 { 1323 int error = -EACCES; 1324 struct inode *inode = dentry->d_inode; 1325 struct path path; 1326 1327 /* Are we allowed to snoop on the tasks file descriptors? */ 1328 if (!proc_fd_access_allowed(inode)) 1329 goto out; 1330 1331 error = PROC_I(inode)->op.proc_get_link(inode, &path); 1332 if (error) 1333 goto out; 1334 1335 error = do_proc_readlink(&path, buffer, buflen); 1336 path_put(&path); 1337 out: 1338 return error; 1339 } 1340 1341 static const struct inode_operations proc_pid_link_inode_operations = { 1342 .readlink = proc_pid_readlink, 1343 .follow_link = proc_pid_follow_link, 1344 .setattr = proc_setattr, 1345 }; 1346 1347 1348 /* building an inode */ 1349 1350 static int task_dumpable(struct task_struct *task) 1351 { 1352 int dumpable = 0; 1353 struct mm_struct *mm; 1354 1355 task_lock(task); 1356 mm = task->mm; 1357 if (mm) 1358 dumpable = get_dumpable(mm); 1359 task_unlock(task); 1360 if(dumpable == 1) 1361 return 1; 1362 return 0; 1363 } 1364 1365 1366 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1367 { 1368 struct inode * inode; 1369 struct proc_inode *ei; 1370 1371 /* We need a new inode */ 1372 1373 inode = new_inode(sb); 1374 if (!inode) 1375 goto out; 1376 1377 /* Common stuff */ 1378 ei = PROC_I(inode); 1379 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1380 inode->i_op = &proc_def_inode_operations; 1381 1382 /* 1383 * grab the reference to task. 1384 */ 1385 ei->pid = get_task_pid(task, PIDTYPE_PID); 1386 if (!ei->pid) 1387 goto out_unlock; 1388 1389 inode->i_uid = 0; 1390 inode->i_gid = 0; 1391 if (task_dumpable(task)) { 1392 inode->i_uid = task->euid; 1393 inode->i_gid = task->egid; 1394 } 1395 security_task_to_inode(task, inode); 1396 1397 out: 1398 return inode; 1399 1400 out_unlock: 1401 iput(inode); 1402 return NULL; 1403 } 1404 1405 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1406 { 1407 struct inode *inode = dentry->d_inode; 1408 struct task_struct *task; 1409 generic_fillattr(inode, stat); 1410 1411 rcu_read_lock(); 1412 stat->uid = 0; 1413 stat->gid = 0; 1414 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1415 if (task) { 1416 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1417 task_dumpable(task)) { 1418 stat->uid = task->euid; 1419 stat->gid = task->egid; 1420 } 1421 } 1422 rcu_read_unlock(); 1423 return 0; 1424 } 1425 1426 /* dentry stuff */ 1427 1428 /* 1429 * Exceptional case: normally we are not allowed to unhash a busy 1430 * directory. In this case, however, we can do it - no aliasing problems 1431 * due to the way we treat inodes. 1432 * 1433 * Rewrite the inode's ownerships here because the owning task may have 1434 * performed a setuid(), etc. 1435 * 1436 * Before the /proc/pid/status file was created the only way to read 1437 * the effective uid of a /process was to stat /proc/pid. Reading 1438 * /proc/pid/status is slow enough that procps and other packages 1439 * kept stating /proc/pid. To keep the rules in /proc simple I have 1440 * made this apply to all per process world readable and executable 1441 * directories. 1442 */ 1443 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1444 { 1445 struct inode *inode = dentry->d_inode; 1446 struct task_struct *task = get_proc_task(inode); 1447 if (task) { 1448 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1449 task_dumpable(task)) { 1450 inode->i_uid = task->euid; 1451 inode->i_gid = task->egid; 1452 } else { 1453 inode->i_uid = 0; 1454 inode->i_gid = 0; 1455 } 1456 inode->i_mode &= ~(S_ISUID | S_ISGID); 1457 security_task_to_inode(task, inode); 1458 put_task_struct(task); 1459 return 1; 1460 } 1461 d_drop(dentry); 1462 return 0; 1463 } 1464 1465 static int pid_delete_dentry(struct dentry * dentry) 1466 { 1467 /* Is the task we represent dead? 1468 * If so, then don't put the dentry on the lru list, 1469 * kill it immediately. 1470 */ 1471 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1472 } 1473 1474 static struct dentry_operations pid_dentry_operations = 1475 { 1476 .d_revalidate = pid_revalidate, 1477 .d_delete = pid_delete_dentry, 1478 }; 1479 1480 /* Lookups */ 1481 1482 typedef struct dentry *instantiate_t(struct inode *, struct dentry *, 1483 struct task_struct *, const void *); 1484 1485 /* 1486 * Fill a directory entry. 1487 * 1488 * If possible create the dcache entry and derive our inode number and 1489 * file type from dcache entry. 1490 * 1491 * Since all of the proc inode numbers are dynamically generated, the inode 1492 * numbers do not exist until the inode is cache. This means creating the 1493 * the dcache entry in readdir is necessary to keep the inode numbers 1494 * reported by readdir in sync with the inode numbers reported 1495 * by stat. 1496 */ 1497 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1498 char *name, int len, 1499 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1500 { 1501 struct dentry *child, *dir = filp->f_path.dentry; 1502 struct inode *inode; 1503 struct qstr qname; 1504 ino_t ino = 0; 1505 unsigned type = DT_UNKNOWN; 1506 1507 qname.name = name; 1508 qname.len = len; 1509 qname.hash = full_name_hash(name, len); 1510 1511 child = d_lookup(dir, &qname); 1512 if (!child) { 1513 struct dentry *new; 1514 new = d_alloc(dir, &qname); 1515 if (new) { 1516 child = instantiate(dir->d_inode, new, task, ptr); 1517 if (child) 1518 dput(new); 1519 else 1520 child = new; 1521 } 1522 } 1523 if (!child || IS_ERR(child) || !child->d_inode) 1524 goto end_instantiate; 1525 inode = child->d_inode; 1526 if (inode) { 1527 ino = inode->i_ino; 1528 type = inode->i_mode >> 12; 1529 } 1530 dput(child); 1531 end_instantiate: 1532 if (!ino) 1533 ino = find_inode_number(dir, &qname); 1534 if (!ino) 1535 ino = 1; 1536 return filldir(dirent, name, len, filp->f_pos, ino, type); 1537 } 1538 1539 static unsigned name_to_int(struct dentry *dentry) 1540 { 1541 const char *name = dentry->d_name.name; 1542 int len = dentry->d_name.len; 1543 unsigned n = 0; 1544 1545 if (len > 1 && *name == '0') 1546 goto out; 1547 while (len-- > 0) { 1548 unsigned c = *name++ - '0'; 1549 if (c > 9) 1550 goto out; 1551 if (n >= (~0U-9)/10) 1552 goto out; 1553 n *= 10; 1554 n += c; 1555 } 1556 return n; 1557 out: 1558 return ~0U; 1559 } 1560 1561 #define PROC_FDINFO_MAX 64 1562 1563 static int proc_fd_info(struct inode *inode, struct path *path, char *info) 1564 { 1565 struct task_struct *task = get_proc_task(inode); 1566 struct files_struct *files = NULL; 1567 struct file *file; 1568 int fd = proc_fd(inode); 1569 1570 if (task) { 1571 files = get_files_struct(task); 1572 put_task_struct(task); 1573 } 1574 if (files) { 1575 /* 1576 * We are not taking a ref to the file structure, so we must 1577 * hold ->file_lock. 1578 */ 1579 spin_lock(&files->file_lock); 1580 file = fcheck_files(files, fd); 1581 if (file) { 1582 if (path) { 1583 *path = file->f_path; 1584 path_get(&file->f_path); 1585 } 1586 if (info) 1587 snprintf(info, PROC_FDINFO_MAX, 1588 "pos:\t%lli\n" 1589 "flags:\t0%o\n", 1590 (long long) file->f_pos, 1591 file->f_flags); 1592 spin_unlock(&files->file_lock); 1593 put_files_struct(files); 1594 return 0; 1595 } 1596 spin_unlock(&files->file_lock); 1597 put_files_struct(files); 1598 } 1599 return -ENOENT; 1600 } 1601 1602 static int proc_fd_link(struct inode *inode, struct path *path) 1603 { 1604 return proc_fd_info(inode, path, NULL); 1605 } 1606 1607 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1608 { 1609 struct inode *inode = dentry->d_inode; 1610 struct task_struct *task = get_proc_task(inode); 1611 int fd = proc_fd(inode); 1612 struct files_struct *files; 1613 1614 if (task) { 1615 files = get_files_struct(task); 1616 if (files) { 1617 rcu_read_lock(); 1618 if (fcheck_files(files, fd)) { 1619 rcu_read_unlock(); 1620 put_files_struct(files); 1621 if (task_dumpable(task)) { 1622 inode->i_uid = task->euid; 1623 inode->i_gid = task->egid; 1624 } else { 1625 inode->i_uid = 0; 1626 inode->i_gid = 0; 1627 } 1628 inode->i_mode &= ~(S_ISUID | S_ISGID); 1629 security_task_to_inode(task, inode); 1630 put_task_struct(task); 1631 return 1; 1632 } 1633 rcu_read_unlock(); 1634 put_files_struct(files); 1635 } 1636 put_task_struct(task); 1637 } 1638 d_drop(dentry); 1639 return 0; 1640 } 1641 1642 static struct dentry_operations tid_fd_dentry_operations = 1643 { 1644 .d_revalidate = tid_fd_revalidate, 1645 .d_delete = pid_delete_dentry, 1646 }; 1647 1648 static struct dentry *proc_fd_instantiate(struct inode *dir, 1649 struct dentry *dentry, struct task_struct *task, const void *ptr) 1650 { 1651 unsigned fd = *(const unsigned *)ptr; 1652 struct file *file; 1653 struct files_struct *files; 1654 struct inode *inode; 1655 struct proc_inode *ei; 1656 struct dentry *error = ERR_PTR(-ENOENT); 1657 1658 inode = proc_pid_make_inode(dir->i_sb, task); 1659 if (!inode) 1660 goto out; 1661 ei = PROC_I(inode); 1662 ei->fd = fd; 1663 files = get_files_struct(task); 1664 if (!files) 1665 goto out_iput; 1666 inode->i_mode = S_IFLNK; 1667 1668 /* 1669 * We are not taking a ref to the file structure, so we must 1670 * hold ->file_lock. 1671 */ 1672 spin_lock(&files->file_lock); 1673 file = fcheck_files(files, fd); 1674 if (!file) 1675 goto out_unlock; 1676 if (file->f_mode & 1) 1677 inode->i_mode |= S_IRUSR | S_IXUSR; 1678 if (file->f_mode & 2) 1679 inode->i_mode |= S_IWUSR | S_IXUSR; 1680 spin_unlock(&files->file_lock); 1681 put_files_struct(files); 1682 1683 inode->i_op = &proc_pid_link_inode_operations; 1684 inode->i_size = 64; 1685 ei->op.proc_get_link = proc_fd_link; 1686 dentry->d_op = &tid_fd_dentry_operations; 1687 d_add(dentry, inode); 1688 /* Close the race of the process dying before we return the dentry */ 1689 if (tid_fd_revalidate(dentry, NULL)) 1690 error = NULL; 1691 1692 out: 1693 return error; 1694 out_unlock: 1695 spin_unlock(&files->file_lock); 1696 put_files_struct(files); 1697 out_iput: 1698 iput(inode); 1699 goto out; 1700 } 1701 1702 static struct dentry *proc_lookupfd_common(struct inode *dir, 1703 struct dentry *dentry, 1704 instantiate_t instantiate) 1705 { 1706 struct task_struct *task = get_proc_task(dir); 1707 unsigned fd = name_to_int(dentry); 1708 struct dentry *result = ERR_PTR(-ENOENT); 1709 1710 if (!task) 1711 goto out_no_task; 1712 if (fd == ~0U) 1713 goto out; 1714 1715 result = instantiate(dir, dentry, task, &fd); 1716 out: 1717 put_task_struct(task); 1718 out_no_task: 1719 return result; 1720 } 1721 1722 static int proc_readfd_common(struct file * filp, void * dirent, 1723 filldir_t filldir, instantiate_t instantiate) 1724 { 1725 struct dentry *dentry = filp->f_path.dentry; 1726 struct inode *inode = dentry->d_inode; 1727 struct task_struct *p = get_proc_task(inode); 1728 unsigned int fd, ino; 1729 int retval; 1730 struct files_struct * files; 1731 1732 retval = -ENOENT; 1733 if (!p) 1734 goto out_no_task; 1735 retval = 0; 1736 1737 fd = filp->f_pos; 1738 switch (fd) { 1739 case 0: 1740 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 1741 goto out; 1742 filp->f_pos++; 1743 case 1: 1744 ino = parent_ino(dentry); 1745 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 1746 goto out; 1747 filp->f_pos++; 1748 default: 1749 files = get_files_struct(p); 1750 if (!files) 1751 goto out; 1752 rcu_read_lock(); 1753 for (fd = filp->f_pos-2; 1754 fd < files_fdtable(files)->max_fds; 1755 fd++, filp->f_pos++) { 1756 char name[PROC_NUMBUF]; 1757 int len; 1758 1759 if (!fcheck_files(files, fd)) 1760 continue; 1761 rcu_read_unlock(); 1762 1763 len = snprintf(name, sizeof(name), "%d", fd); 1764 if (proc_fill_cache(filp, dirent, filldir, 1765 name, len, instantiate, 1766 p, &fd) < 0) { 1767 rcu_read_lock(); 1768 break; 1769 } 1770 rcu_read_lock(); 1771 } 1772 rcu_read_unlock(); 1773 put_files_struct(files); 1774 } 1775 out: 1776 put_task_struct(p); 1777 out_no_task: 1778 return retval; 1779 } 1780 1781 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 1782 struct nameidata *nd) 1783 { 1784 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 1785 } 1786 1787 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 1788 { 1789 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 1790 } 1791 1792 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 1793 size_t len, loff_t *ppos) 1794 { 1795 char tmp[PROC_FDINFO_MAX]; 1796 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); 1797 if (!err) 1798 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 1799 return err; 1800 } 1801 1802 static const struct file_operations proc_fdinfo_file_operations = { 1803 .open = nonseekable_open, 1804 .read = proc_fdinfo_read, 1805 }; 1806 1807 static const struct file_operations proc_fd_operations = { 1808 .read = generic_read_dir, 1809 .readdir = proc_readfd, 1810 }; 1811 1812 /* 1813 * /proc/pid/fd needs a special permission handler so that a process can still 1814 * access /proc/self/fd after it has executed a setuid(). 1815 */ 1816 static int proc_fd_permission(struct inode *inode, int mask, 1817 struct nameidata *nd) 1818 { 1819 int rv; 1820 1821 rv = generic_permission(inode, mask, NULL); 1822 if (rv == 0) 1823 return 0; 1824 if (task_pid(current) == proc_pid(inode)) 1825 rv = 0; 1826 return rv; 1827 } 1828 1829 /* 1830 * proc directories can do almost nothing.. 1831 */ 1832 static const struct inode_operations proc_fd_inode_operations = { 1833 .lookup = proc_lookupfd, 1834 .permission = proc_fd_permission, 1835 .setattr = proc_setattr, 1836 }; 1837 1838 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 1839 struct dentry *dentry, struct task_struct *task, const void *ptr) 1840 { 1841 unsigned fd = *(unsigned *)ptr; 1842 struct inode *inode; 1843 struct proc_inode *ei; 1844 struct dentry *error = ERR_PTR(-ENOENT); 1845 1846 inode = proc_pid_make_inode(dir->i_sb, task); 1847 if (!inode) 1848 goto out; 1849 ei = PROC_I(inode); 1850 ei->fd = fd; 1851 inode->i_mode = S_IFREG | S_IRUSR; 1852 inode->i_fop = &proc_fdinfo_file_operations; 1853 dentry->d_op = &tid_fd_dentry_operations; 1854 d_add(dentry, inode); 1855 /* Close the race of the process dying before we return the dentry */ 1856 if (tid_fd_revalidate(dentry, NULL)) 1857 error = NULL; 1858 1859 out: 1860 return error; 1861 } 1862 1863 static struct dentry *proc_lookupfdinfo(struct inode *dir, 1864 struct dentry *dentry, 1865 struct nameidata *nd) 1866 { 1867 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 1868 } 1869 1870 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 1871 { 1872 return proc_readfd_common(filp, dirent, filldir, 1873 proc_fdinfo_instantiate); 1874 } 1875 1876 static const struct file_operations proc_fdinfo_operations = { 1877 .read = generic_read_dir, 1878 .readdir = proc_readfdinfo, 1879 }; 1880 1881 /* 1882 * proc directories can do almost nothing.. 1883 */ 1884 static const struct inode_operations proc_fdinfo_inode_operations = { 1885 .lookup = proc_lookupfdinfo, 1886 .setattr = proc_setattr, 1887 }; 1888 1889 1890 static struct dentry *proc_pident_instantiate(struct inode *dir, 1891 struct dentry *dentry, struct task_struct *task, const void *ptr) 1892 { 1893 const struct pid_entry *p = ptr; 1894 struct inode *inode; 1895 struct proc_inode *ei; 1896 struct dentry *error = ERR_PTR(-EINVAL); 1897 1898 inode = proc_pid_make_inode(dir->i_sb, task); 1899 if (!inode) 1900 goto out; 1901 1902 ei = PROC_I(inode); 1903 inode->i_mode = p->mode; 1904 if (S_ISDIR(inode->i_mode)) 1905 inode->i_nlink = 2; /* Use getattr to fix if necessary */ 1906 if (p->iop) 1907 inode->i_op = p->iop; 1908 if (p->fop) 1909 inode->i_fop = p->fop; 1910 ei->op = p->op; 1911 dentry->d_op = &pid_dentry_operations; 1912 d_add(dentry, inode); 1913 /* Close the race of the process dying before we return the dentry */ 1914 if (pid_revalidate(dentry, NULL)) 1915 error = NULL; 1916 out: 1917 return error; 1918 } 1919 1920 static struct dentry *proc_pident_lookup(struct inode *dir, 1921 struct dentry *dentry, 1922 const struct pid_entry *ents, 1923 unsigned int nents) 1924 { 1925 struct inode *inode; 1926 struct dentry *error; 1927 struct task_struct *task = get_proc_task(dir); 1928 const struct pid_entry *p, *last; 1929 1930 error = ERR_PTR(-ENOENT); 1931 inode = NULL; 1932 1933 if (!task) 1934 goto out_no_task; 1935 1936 /* 1937 * Yes, it does not scale. And it should not. Don't add 1938 * new entries into /proc/<tgid>/ without very good reasons. 1939 */ 1940 last = &ents[nents - 1]; 1941 for (p = ents; p <= last; p++) { 1942 if (p->len != dentry->d_name.len) 1943 continue; 1944 if (!memcmp(dentry->d_name.name, p->name, p->len)) 1945 break; 1946 } 1947 if (p > last) 1948 goto out; 1949 1950 error = proc_pident_instantiate(dir, dentry, task, p); 1951 out: 1952 put_task_struct(task); 1953 out_no_task: 1954 return error; 1955 } 1956 1957 static int proc_pident_fill_cache(struct file *filp, void *dirent, 1958 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 1959 { 1960 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 1961 proc_pident_instantiate, task, p); 1962 } 1963 1964 static int proc_pident_readdir(struct file *filp, 1965 void *dirent, filldir_t filldir, 1966 const struct pid_entry *ents, unsigned int nents) 1967 { 1968 int i; 1969 struct dentry *dentry = filp->f_path.dentry; 1970 struct inode *inode = dentry->d_inode; 1971 struct task_struct *task = get_proc_task(inode); 1972 const struct pid_entry *p, *last; 1973 ino_t ino; 1974 int ret; 1975 1976 ret = -ENOENT; 1977 if (!task) 1978 goto out_no_task; 1979 1980 ret = 0; 1981 i = filp->f_pos; 1982 switch (i) { 1983 case 0: 1984 ino = inode->i_ino; 1985 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 1986 goto out; 1987 i++; 1988 filp->f_pos++; 1989 /* fall through */ 1990 case 1: 1991 ino = parent_ino(dentry); 1992 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 1993 goto out; 1994 i++; 1995 filp->f_pos++; 1996 /* fall through */ 1997 default: 1998 i -= 2; 1999 if (i >= nents) { 2000 ret = 1; 2001 goto out; 2002 } 2003 p = ents + i; 2004 last = &ents[nents - 1]; 2005 while (p <= last) { 2006 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2007 goto out; 2008 filp->f_pos++; 2009 p++; 2010 } 2011 } 2012 2013 ret = 1; 2014 out: 2015 put_task_struct(task); 2016 out_no_task: 2017 return ret; 2018 } 2019 2020 #ifdef CONFIG_SECURITY 2021 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2022 size_t count, loff_t *ppos) 2023 { 2024 struct inode * inode = file->f_path.dentry->d_inode; 2025 char *p = NULL; 2026 ssize_t length; 2027 struct task_struct *task = get_proc_task(inode); 2028 2029 if (!task) 2030 return -ESRCH; 2031 2032 length = security_getprocattr(task, 2033 (char*)file->f_path.dentry->d_name.name, 2034 &p); 2035 put_task_struct(task); 2036 if (length > 0) 2037 length = simple_read_from_buffer(buf, count, ppos, p, length); 2038 kfree(p); 2039 return length; 2040 } 2041 2042 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2043 size_t count, loff_t *ppos) 2044 { 2045 struct inode * inode = file->f_path.dentry->d_inode; 2046 char *page; 2047 ssize_t length; 2048 struct task_struct *task = get_proc_task(inode); 2049 2050 length = -ESRCH; 2051 if (!task) 2052 goto out_no_task; 2053 if (count > PAGE_SIZE) 2054 count = PAGE_SIZE; 2055 2056 /* No partial writes. */ 2057 length = -EINVAL; 2058 if (*ppos != 0) 2059 goto out; 2060 2061 length = -ENOMEM; 2062 page = (char*)__get_free_page(GFP_TEMPORARY); 2063 if (!page) 2064 goto out; 2065 2066 length = -EFAULT; 2067 if (copy_from_user(page, buf, count)) 2068 goto out_free; 2069 2070 length = security_setprocattr(task, 2071 (char*)file->f_path.dentry->d_name.name, 2072 (void*)page, count); 2073 out_free: 2074 free_page((unsigned long) page); 2075 out: 2076 put_task_struct(task); 2077 out_no_task: 2078 return length; 2079 } 2080 2081 static const struct file_operations proc_pid_attr_operations = { 2082 .read = proc_pid_attr_read, 2083 .write = proc_pid_attr_write, 2084 }; 2085 2086 static const struct pid_entry attr_dir_stuff[] = { 2087 REG("current", S_IRUGO|S_IWUGO, pid_attr), 2088 REG("prev", S_IRUGO, pid_attr), 2089 REG("exec", S_IRUGO|S_IWUGO, pid_attr), 2090 REG("fscreate", S_IRUGO|S_IWUGO, pid_attr), 2091 REG("keycreate", S_IRUGO|S_IWUGO, pid_attr), 2092 REG("sockcreate", S_IRUGO|S_IWUGO, pid_attr), 2093 }; 2094 2095 static int proc_attr_dir_readdir(struct file * filp, 2096 void * dirent, filldir_t filldir) 2097 { 2098 return proc_pident_readdir(filp,dirent,filldir, 2099 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2100 } 2101 2102 static const struct file_operations proc_attr_dir_operations = { 2103 .read = generic_read_dir, 2104 .readdir = proc_attr_dir_readdir, 2105 }; 2106 2107 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2108 struct dentry *dentry, struct nameidata *nd) 2109 { 2110 return proc_pident_lookup(dir, dentry, 2111 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2112 } 2113 2114 static const struct inode_operations proc_attr_dir_inode_operations = { 2115 .lookup = proc_attr_dir_lookup, 2116 .getattr = pid_getattr, 2117 .setattr = proc_setattr, 2118 }; 2119 2120 #endif 2121 2122 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2123 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2124 size_t count, loff_t *ppos) 2125 { 2126 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2127 struct mm_struct *mm; 2128 char buffer[PROC_NUMBUF]; 2129 size_t len; 2130 int ret; 2131 2132 if (!task) 2133 return -ESRCH; 2134 2135 ret = 0; 2136 mm = get_task_mm(task); 2137 if (mm) { 2138 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2139 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2140 MMF_DUMP_FILTER_SHIFT)); 2141 mmput(mm); 2142 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2143 } 2144 2145 put_task_struct(task); 2146 2147 return ret; 2148 } 2149 2150 static ssize_t proc_coredump_filter_write(struct file *file, 2151 const char __user *buf, 2152 size_t count, 2153 loff_t *ppos) 2154 { 2155 struct task_struct *task; 2156 struct mm_struct *mm; 2157 char buffer[PROC_NUMBUF], *end; 2158 unsigned int val; 2159 int ret; 2160 int i; 2161 unsigned long mask; 2162 2163 ret = -EFAULT; 2164 memset(buffer, 0, sizeof(buffer)); 2165 if (count > sizeof(buffer) - 1) 2166 count = sizeof(buffer) - 1; 2167 if (copy_from_user(buffer, buf, count)) 2168 goto out_no_task; 2169 2170 ret = -EINVAL; 2171 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2172 if (*end == '\n') 2173 end++; 2174 if (end - buffer == 0) 2175 goto out_no_task; 2176 2177 ret = -ESRCH; 2178 task = get_proc_task(file->f_dentry->d_inode); 2179 if (!task) 2180 goto out_no_task; 2181 2182 ret = end - buffer; 2183 mm = get_task_mm(task); 2184 if (!mm) 2185 goto out_no_mm; 2186 2187 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2188 if (val & mask) 2189 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2190 else 2191 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2192 } 2193 2194 mmput(mm); 2195 out_no_mm: 2196 put_task_struct(task); 2197 out_no_task: 2198 return ret; 2199 } 2200 2201 static const struct file_operations proc_coredump_filter_operations = { 2202 .read = proc_coredump_filter_read, 2203 .write = proc_coredump_filter_write, 2204 }; 2205 #endif 2206 2207 /* 2208 * /proc/self: 2209 */ 2210 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2211 int buflen) 2212 { 2213 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2214 pid_t tgid = task_tgid_nr_ns(current, ns); 2215 char tmp[PROC_NUMBUF]; 2216 if (!tgid) 2217 return -ENOENT; 2218 sprintf(tmp, "%d", tgid); 2219 return vfs_readlink(dentry,buffer,buflen,tmp); 2220 } 2221 2222 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2223 { 2224 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2225 pid_t tgid = task_tgid_nr_ns(current, ns); 2226 char tmp[PROC_NUMBUF]; 2227 if (!tgid) 2228 return ERR_PTR(-ENOENT); 2229 sprintf(tmp, "%d", task_tgid_nr_ns(current, ns)); 2230 return ERR_PTR(vfs_follow_link(nd,tmp)); 2231 } 2232 2233 static const struct inode_operations proc_self_inode_operations = { 2234 .readlink = proc_self_readlink, 2235 .follow_link = proc_self_follow_link, 2236 }; 2237 2238 /* 2239 * proc base 2240 * 2241 * These are the directory entries in the root directory of /proc 2242 * that properly belong to the /proc filesystem, as they describe 2243 * describe something that is process related. 2244 */ 2245 static const struct pid_entry proc_base_stuff[] = { 2246 NOD("self", S_IFLNK|S_IRWXUGO, 2247 &proc_self_inode_operations, NULL, {}), 2248 }; 2249 2250 /* 2251 * Exceptional case: normally we are not allowed to unhash a busy 2252 * directory. In this case, however, we can do it - no aliasing problems 2253 * due to the way we treat inodes. 2254 */ 2255 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) 2256 { 2257 struct inode *inode = dentry->d_inode; 2258 struct task_struct *task = get_proc_task(inode); 2259 if (task) { 2260 put_task_struct(task); 2261 return 1; 2262 } 2263 d_drop(dentry); 2264 return 0; 2265 } 2266 2267 static struct dentry_operations proc_base_dentry_operations = 2268 { 2269 .d_revalidate = proc_base_revalidate, 2270 .d_delete = pid_delete_dentry, 2271 }; 2272 2273 static struct dentry *proc_base_instantiate(struct inode *dir, 2274 struct dentry *dentry, struct task_struct *task, const void *ptr) 2275 { 2276 const struct pid_entry *p = ptr; 2277 struct inode *inode; 2278 struct proc_inode *ei; 2279 struct dentry *error = ERR_PTR(-EINVAL); 2280 2281 /* Allocate the inode */ 2282 error = ERR_PTR(-ENOMEM); 2283 inode = new_inode(dir->i_sb); 2284 if (!inode) 2285 goto out; 2286 2287 /* Initialize the inode */ 2288 ei = PROC_I(inode); 2289 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2290 2291 /* 2292 * grab the reference to the task. 2293 */ 2294 ei->pid = get_task_pid(task, PIDTYPE_PID); 2295 if (!ei->pid) 2296 goto out_iput; 2297 2298 inode->i_uid = 0; 2299 inode->i_gid = 0; 2300 inode->i_mode = p->mode; 2301 if (S_ISDIR(inode->i_mode)) 2302 inode->i_nlink = 2; 2303 if (S_ISLNK(inode->i_mode)) 2304 inode->i_size = 64; 2305 if (p->iop) 2306 inode->i_op = p->iop; 2307 if (p->fop) 2308 inode->i_fop = p->fop; 2309 ei->op = p->op; 2310 dentry->d_op = &proc_base_dentry_operations; 2311 d_add(dentry, inode); 2312 error = NULL; 2313 out: 2314 return error; 2315 out_iput: 2316 iput(inode); 2317 goto out; 2318 } 2319 2320 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2321 { 2322 struct dentry *error; 2323 struct task_struct *task = get_proc_task(dir); 2324 const struct pid_entry *p, *last; 2325 2326 error = ERR_PTR(-ENOENT); 2327 2328 if (!task) 2329 goto out_no_task; 2330 2331 /* Lookup the directory entry */ 2332 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2333 for (p = proc_base_stuff; p <= last; p++) { 2334 if (p->len != dentry->d_name.len) 2335 continue; 2336 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2337 break; 2338 } 2339 if (p > last) 2340 goto out; 2341 2342 error = proc_base_instantiate(dir, dentry, task, p); 2343 2344 out: 2345 put_task_struct(task); 2346 out_no_task: 2347 return error; 2348 } 2349 2350 static int proc_base_fill_cache(struct file *filp, void *dirent, 2351 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2352 { 2353 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2354 proc_base_instantiate, task, p); 2355 } 2356 2357 #ifdef CONFIG_TASK_IO_ACCOUNTING 2358 static int proc_pid_io_accounting(struct task_struct *task, char *buffer) 2359 { 2360 return sprintf(buffer, 2361 #ifdef CONFIG_TASK_XACCT 2362 "rchar: %llu\n" 2363 "wchar: %llu\n" 2364 "syscr: %llu\n" 2365 "syscw: %llu\n" 2366 #endif 2367 "read_bytes: %llu\n" 2368 "write_bytes: %llu\n" 2369 "cancelled_write_bytes: %llu\n", 2370 #ifdef CONFIG_TASK_XACCT 2371 (unsigned long long)task->rchar, 2372 (unsigned long long)task->wchar, 2373 (unsigned long long)task->syscr, 2374 (unsigned long long)task->syscw, 2375 #endif 2376 (unsigned long long)task->ioac.read_bytes, 2377 (unsigned long long)task->ioac.write_bytes, 2378 (unsigned long long)task->ioac.cancelled_write_bytes); 2379 } 2380 #endif 2381 2382 /* 2383 * Thread groups 2384 */ 2385 static const struct file_operations proc_task_operations; 2386 static const struct inode_operations proc_task_inode_operations; 2387 2388 static const struct pid_entry tgid_base_stuff[] = { 2389 DIR("task", S_IRUGO|S_IXUGO, task), 2390 DIR("fd", S_IRUSR|S_IXUSR, fd), 2391 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), 2392 #ifdef CONFIG_NET 2393 DIR("net", S_IRUGO|S_IXUGO, net), 2394 #endif 2395 REG("environ", S_IRUSR, environ), 2396 INF("auxv", S_IRUSR, pid_auxv), 2397 ONE("status", S_IRUGO, pid_status), 2398 INF("limits", S_IRUSR, pid_limits), 2399 #ifdef CONFIG_SCHED_DEBUG 2400 REG("sched", S_IRUGO|S_IWUSR, pid_sched), 2401 #endif 2402 INF("cmdline", S_IRUGO, pid_cmdline), 2403 ONE("stat", S_IRUGO, tgid_stat), 2404 ONE("statm", S_IRUGO, pid_statm), 2405 REG("maps", S_IRUGO, maps), 2406 #ifdef CONFIG_NUMA 2407 REG("numa_maps", S_IRUGO, numa_maps), 2408 #endif 2409 REG("mem", S_IRUSR|S_IWUSR, mem), 2410 LNK("cwd", cwd), 2411 LNK("root", root), 2412 LNK("exe", exe), 2413 REG("mounts", S_IRUGO, mounts), 2414 REG("mountinfo", S_IRUGO, mountinfo), 2415 REG("mountstats", S_IRUSR, mountstats), 2416 #ifdef CONFIG_PROC_PAGE_MONITOR 2417 REG("clear_refs", S_IWUSR, clear_refs), 2418 REG("smaps", S_IRUGO, smaps), 2419 REG("pagemap", S_IRUSR, pagemap), 2420 #endif 2421 #ifdef CONFIG_SECURITY 2422 DIR("attr", S_IRUGO|S_IXUGO, attr_dir), 2423 #endif 2424 #ifdef CONFIG_KALLSYMS 2425 INF("wchan", S_IRUGO, pid_wchan), 2426 #endif 2427 #ifdef CONFIG_SCHEDSTATS 2428 INF("schedstat", S_IRUGO, pid_schedstat), 2429 #endif 2430 #ifdef CONFIG_LATENCYTOP 2431 REG("latency", S_IRUGO, lstats), 2432 #endif 2433 #ifdef CONFIG_PROC_PID_CPUSET 2434 REG("cpuset", S_IRUGO, cpuset), 2435 #endif 2436 #ifdef CONFIG_CGROUPS 2437 REG("cgroup", S_IRUGO, cgroup), 2438 #endif 2439 INF("oom_score", S_IRUGO, oom_score), 2440 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust), 2441 #ifdef CONFIG_AUDITSYSCALL 2442 REG("loginuid", S_IWUSR|S_IRUGO, loginuid), 2443 REG("sessionid", S_IRUSR, sessionid), 2444 #endif 2445 #ifdef CONFIG_FAULT_INJECTION 2446 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject), 2447 #endif 2448 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2449 REG("coredump_filter", S_IRUGO|S_IWUSR, coredump_filter), 2450 #endif 2451 #ifdef CONFIG_TASK_IO_ACCOUNTING 2452 INF("io", S_IRUGO, pid_io_accounting), 2453 #endif 2454 }; 2455 2456 static int proc_tgid_base_readdir(struct file * filp, 2457 void * dirent, filldir_t filldir) 2458 { 2459 return proc_pident_readdir(filp,dirent,filldir, 2460 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2461 } 2462 2463 static const struct file_operations proc_tgid_base_operations = { 2464 .read = generic_read_dir, 2465 .readdir = proc_tgid_base_readdir, 2466 }; 2467 2468 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2469 return proc_pident_lookup(dir, dentry, 2470 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2471 } 2472 2473 static const struct inode_operations proc_tgid_base_inode_operations = { 2474 .lookup = proc_tgid_base_lookup, 2475 .getattr = pid_getattr, 2476 .setattr = proc_setattr, 2477 }; 2478 2479 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2480 { 2481 struct dentry *dentry, *leader, *dir; 2482 char buf[PROC_NUMBUF]; 2483 struct qstr name; 2484 2485 name.name = buf; 2486 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2487 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2488 if (dentry) { 2489 if (!(current->flags & PF_EXITING)) 2490 shrink_dcache_parent(dentry); 2491 d_drop(dentry); 2492 dput(dentry); 2493 } 2494 2495 if (tgid == 0) 2496 goto out; 2497 2498 name.name = buf; 2499 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2500 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2501 if (!leader) 2502 goto out; 2503 2504 name.name = "task"; 2505 name.len = strlen(name.name); 2506 dir = d_hash_and_lookup(leader, &name); 2507 if (!dir) 2508 goto out_put_leader; 2509 2510 name.name = buf; 2511 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2512 dentry = d_hash_and_lookup(dir, &name); 2513 if (dentry) { 2514 shrink_dcache_parent(dentry); 2515 d_drop(dentry); 2516 dput(dentry); 2517 } 2518 2519 dput(dir); 2520 out_put_leader: 2521 dput(leader); 2522 out: 2523 return; 2524 } 2525 2526 /** 2527 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2528 * @task: task that should be flushed. 2529 * 2530 * When flushing dentries from proc, one needs to flush them from global 2531 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2532 * in. This call is supposed to do all of this job. 2533 * 2534 * Looks in the dcache for 2535 * /proc/@pid 2536 * /proc/@tgid/task/@pid 2537 * if either directory is present flushes it and all of it'ts children 2538 * from the dcache. 2539 * 2540 * It is safe and reasonable to cache /proc entries for a task until 2541 * that task exits. After that they just clog up the dcache with 2542 * useless entries, possibly causing useful dcache entries to be 2543 * flushed instead. This routine is proved to flush those useless 2544 * dcache entries at process exit time. 2545 * 2546 * NOTE: This routine is just an optimization so it does not guarantee 2547 * that no dcache entries will exist at process exit time it 2548 * just makes it very unlikely that any will persist. 2549 */ 2550 2551 void proc_flush_task(struct task_struct *task) 2552 { 2553 int i; 2554 struct pid *pid, *tgid = NULL; 2555 struct upid *upid; 2556 2557 pid = task_pid(task); 2558 if (thread_group_leader(task)) 2559 tgid = task_tgid(task); 2560 2561 for (i = 0; i <= pid->level; i++) { 2562 upid = &pid->numbers[i]; 2563 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 2564 tgid ? tgid->numbers[i].nr : 0); 2565 } 2566 2567 upid = &pid->numbers[pid->level]; 2568 if (upid->nr == 1) 2569 pid_ns_release_proc(upid->ns); 2570 } 2571 2572 static struct dentry *proc_pid_instantiate(struct inode *dir, 2573 struct dentry * dentry, 2574 struct task_struct *task, const void *ptr) 2575 { 2576 struct dentry *error = ERR_PTR(-ENOENT); 2577 struct inode *inode; 2578 2579 inode = proc_pid_make_inode(dir->i_sb, task); 2580 if (!inode) 2581 goto out; 2582 2583 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2584 inode->i_op = &proc_tgid_base_inode_operations; 2585 inode->i_fop = &proc_tgid_base_operations; 2586 inode->i_flags|=S_IMMUTABLE; 2587 inode->i_nlink = 5; 2588 #ifdef CONFIG_SECURITY 2589 inode->i_nlink += 1; 2590 #endif 2591 2592 dentry->d_op = &pid_dentry_operations; 2593 2594 d_add(dentry, inode); 2595 /* Close the race of the process dying before we return the dentry */ 2596 if (pid_revalidate(dentry, NULL)) 2597 error = NULL; 2598 out: 2599 return error; 2600 } 2601 2602 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2603 { 2604 struct dentry *result = ERR_PTR(-ENOENT); 2605 struct task_struct *task; 2606 unsigned tgid; 2607 struct pid_namespace *ns; 2608 2609 result = proc_base_lookup(dir, dentry); 2610 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 2611 goto out; 2612 2613 tgid = name_to_int(dentry); 2614 if (tgid == ~0U) 2615 goto out; 2616 2617 ns = dentry->d_sb->s_fs_info; 2618 rcu_read_lock(); 2619 task = find_task_by_pid_ns(tgid, ns); 2620 if (task) 2621 get_task_struct(task); 2622 rcu_read_unlock(); 2623 if (!task) 2624 goto out; 2625 2626 result = proc_pid_instantiate(dir, dentry, task, NULL); 2627 put_task_struct(task); 2628 out: 2629 return result; 2630 } 2631 2632 /* 2633 * Find the first task with tgid >= tgid 2634 * 2635 */ 2636 struct tgid_iter { 2637 unsigned int tgid; 2638 struct task_struct *task; 2639 }; 2640 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 2641 { 2642 struct pid *pid; 2643 2644 if (iter.task) 2645 put_task_struct(iter.task); 2646 rcu_read_lock(); 2647 retry: 2648 iter.task = NULL; 2649 pid = find_ge_pid(iter.tgid, ns); 2650 if (pid) { 2651 iter.tgid = pid_nr_ns(pid, ns); 2652 iter.task = pid_task(pid, PIDTYPE_PID); 2653 /* What we to know is if the pid we have find is the 2654 * pid of a thread_group_leader. Testing for task 2655 * being a thread_group_leader is the obvious thing 2656 * todo but there is a window when it fails, due to 2657 * the pid transfer logic in de_thread. 2658 * 2659 * So we perform the straight forward test of seeing 2660 * if the pid we have found is the pid of a thread 2661 * group leader, and don't worry if the task we have 2662 * found doesn't happen to be a thread group leader. 2663 * As we don't care in the case of readdir. 2664 */ 2665 if (!iter.task || !has_group_leader_pid(iter.task)) { 2666 iter.tgid += 1; 2667 goto retry; 2668 } 2669 get_task_struct(iter.task); 2670 } 2671 rcu_read_unlock(); 2672 return iter; 2673 } 2674 2675 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 2676 2677 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2678 struct tgid_iter iter) 2679 { 2680 char name[PROC_NUMBUF]; 2681 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 2682 return proc_fill_cache(filp, dirent, filldir, name, len, 2683 proc_pid_instantiate, iter.task, NULL); 2684 } 2685 2686 /* for the /proc/ directory itself, after non-process stuff has been done */ 2687 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 2688 { 2689 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; 2690 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode); 2691 struct tgid_iter iter; 2692 struct pid_namespace *ns; 2693 2694 if (!reaper) 2695 goto out_no_task; 2696 2697 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 2698 const struct pid_entry *p = &proc_base_stuff[nr]; 2699 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 2700 goto out; 2701 } 2702 2703 ns = filp->f_dentry->d_sb->s_fs_info; 2704 iter.task = NULL; 2705 iter.tgid = filp->f_pos - TGID_OFFSET; 2706 for (iter = next_tgid(ns, iter); 2707 iter.task; 2708 iter.tgid += 1, iter = next_tgid(ns, iter)) { 2709 filp->f_pos = iter.tgid + TGID_OFFSET; 2710 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) { 2711 put_task_struct(iter.task); 2712 goto out; 2713 } 2714 } 2715 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 2716 out: 2717 put_task_struct(reaper); 2718 out_no_task: 2719 return 0; 2720 } 2721 2722 /* 2723 * Tasks 2724 */ 2725 static const struct pid_entry tid_base_stuff[] = { 2726 DIR("fd", S_IRUSR|S_IXUSR, fd), 2727 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), 2728 REG("environ", S_IRUSR, environ), 2729 INF("auxv", S_IRUSR, pid_auxv), 2730 ONE("status", S_IRUGO, pid_status), 2731 INF("limits", S_IRUSR, pid_limits), 2732 #ifdef CONFIG_SCHED_DEBUG 2733 REG("sched", S_IRUGO|S_IWUSR, pid_sched), 2734 #endif 2735 INF("cmdline", S_IRUGO, pid_cmdline), 2736 ONE("stat", S_IRUGO, tid_stat), 2737 ONE("statm", S_IRUGO, pid_statm), 2738 REG("maps", S_IRUGO, maps), 2739 #ifdef CONFIG_NUMA 2740 REG("numa_maps", S_IRUGO, numa_maps), 2741 #endif 2742 REG("mem", S_IRUSR|S_IWUSR, mem), 2743 LNK("cwd", cwd), 2744 LNK("root", root), 2745 LNK("exe", exe), 2746 REG("mounts", S_IRUGO, mounts), 2747 REG("mountinfo", S_IRUGO, mountinfo), 2748 #ifdef CONFIG_PROC_PAGE_MONITOR 2749 REG("clear_refs", S_IWUSR, clear_refs), 2750 REG("smaps", S_IRUGO, smaps), 2751 REG("pagemap", S_IRUSR, pagemap), 2752 #endif 2753 #ifdef CONFIG_SECURITY 2754 DIR("attr", S_IRUGO|S_IXUGO, attr_dir), 2755 #endif 2756 #ifdef CONFIG_KALLSYMS 2757 INF("wchan", S_IRUGO, pid_wchan), 2758 #endif 2759 #ifdef CONFIG_SCHEDSTATS 2760 INF("schedstat", S_IRUGO, pid_schedstat), 2761 #endif 2762 #ifdef CONFIG_LATENCYTOP 2763 REG("latency", S_IRUGO, lstats), 2764 #endif 2765 #ifdef CONFIG_PROC_PID_CPUSET 2766 REG("cpuset", S_IRUGO, cpuset), 2767 #endif 2768 #ifdef CONFIG_CGROUPS 2769 REG("cgroup", S_IRUGO, cgroup), 2770 #endif 2771 INF("oom_score", S_IRUGO, oom_score), 2772 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust), 2773 #ifdef CONFIG_AUDITSYSCALL 2774 REG("loginuid", S_IWUSR|S_IRUGO, loginuid), 2775 REG("sessionid", S_IRUSR, sessionid), 2776 #endif 2777 #ifdef CONFIG_FAULT_INJECTION 2778 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject), 2779 #endif 2780 }; 2781 2782 static int proc_tid_base_readdir(struct file * filp, 2783 void * dirent, filldir_t filldir) 2784 { 2785 return proc_pident_readdir(filp,dirent,filldir, 2786 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 2787 } 2788 2789 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2790 return proc_pident_lookup(dir, dentry, 2791 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 2792 } 2793 2794 static const struct file_operations proc_tid_base_operations = { 2795 .read = generic_read_dir, 2796 .readdir = proc_tid_base_readdir, 2797 }; 2798 2799 static const struct inode_operations proc_tid_base_inode_operations = { 2800 .lookup = proc_tid_base_lookup, 2801 .getattr = pid_getattr, 2802 .setattr = proc_setattr, 2803 }; 2804 2805 static struct dentry *proc_task_instantiate(struct inode *dir, 2806 struct dentry *dentry, struct task_struct *task, const void *ptr) 2807 { 2808 struct dentry *error = ERR_PTR(-ENOENT); 2809 struct inode *inode; 2810 inode = proc_pid_make_inode(dir->i_sb, task); 2811 2812 if (!inode) 2813 goto out; 2814 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2815 inode->i_op = &proc_tid_base_inode_operations; 2816 inode->i_fop = &proc_tid_base_operations; 2817 inode->i_flags|=S_IMMUTABLE; 2818 inode->i_nlink = 4; 2819 #ifdef CONFIG_SECURITY 2820 inode->i_nlink += 1; 2821 #endif 2822 2823 dentry->d_op = &pid_dentry_operations; 2824 2825 d_add(dentry, inode); 2826 /* Close the race of the process dying before we return the dentry */ 2827 if (pid_revalidate(dentry, NULL)) 2828 error = NULL; 2829 out: 2830 return error; 2831 } 2832 2833 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2834 { 2835 struct dentry *result = ERR_PTR(-ENOENT); 2836 struct task_struct *task; 2837 struct task_struct *leader = get_proc_task(dir); 2838 unsigned tid; 2839 struct pid_namespace *ns; 2840 2841 if (!leader) 2842 goto out_no_task; 2843 2844 tid = name_to_int(dentry); 2845 if (tid == ~0U) 2846 goto out; 2847 2848 ns = dentry->d_sb->s_fs_info; 2849 rcu_read_lock(); 2850 task = find_task_by_pid_ns(tid, ns); 2851 if (task) 2852 get_task_struct(task); 2853 rcu_read_unlock(); 2854 if (!task) 2855 goto out; 2856 if (!same_thread_group(leader, task)) 2857 goto out_drop_task; 2858 2859 result = proc_task_instantiate(dir, dentry, task, NULL); 2860 out_drop_task: 2861 put_task_struct(task); 2862 out: 2863 put_task_struct(leader); 2864 out_no_task: 2865 return result; 2866 } 2867 2868 /* 2869 * Find the first tid of a thread group to return to user space. 2870 * 2871 * Usually this is just the thread group leader, but if the users 2872 * buffer was too small or there was a seek into the middle of the 2873 * directory we have more work todo. 2874 * 2875 * In the case of a short read we start with find_task_by_pid. 2876 * 2877 * In the case of a seek we start with the leader and walk nr 2878 * threads past it. 2879 */ 2880 static struct task_struct *first_tid(struct task_struct *leader, 2881 int tid, int nr, struct pid_namespace *ns) 2882 { 2883 struct task_struct *pos; 2884 2885 rcu_read_lock(); 2886 /* Attempt to start with the pid of a thread */ 2887 if (tid && (nr > 0)) { 2888 pos = find_task_by_pid_ns(tid, ns); 2889 if (pos && (pos->group_leader == leader)) 2890 goto found; 2891 } 2892 2893 /* If nr exceeds the number of threads there is nothing todo */ 2894 pos = NULL; 2895 if (nr && nr >= get_nr_threads(leader)) 2896 goto out; 2897 2898 /* If we haven't found our starting place yet start 2899 * with the leader and walk nr threads forward. 2900 */ 2901 for (pos = leader; nr > 0; --nr) { 2902 pos = next_thread(pos); 2903 if (pos == leader) { 2904 pos = NULL; 2905 goto out; 2906 } 2907 } 2908 found: 2909 get_task_struct(pos); 2910 out: 2911 rcu_read_unlock(); 2912 return pos; 2913 } 2914 2915 /* 2916 * Find the next thread in the thread list. 2917 * Return NULL if there is an error or no next thread. 2918 * 2919 * The reference to the input task_struct is released. 2920 */ 2921 static struct task_struct *next_tid(struct task_struct *start) 2922 { 2923 struct task_struct *pos = NULL; 2924 rcu_read_lock(); 2925 if (pid_alive(start)) { 2926 pos = next_thread(start); 2927 if (thread_group_leader(pos)) 2928 pos = NULL; 2929 else 2930 get_task_struct(pos); 2931 } 2932 rcu_read_unlock(); 2933 put_task_struct(start); 2934 return pos; 2935 } 2936 2937 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2938 struct task_struct *task, int tid) 2939 { 2940 char name[PROC_NUMBUF]; 2941 int len = snprintf(name, sizeof(name), "%d", tid); 2942 return proc_fill_cache(filp, dirent, filldir, name, len, 2943 proc_task_instantiate, task, NULL); 2944 } 2945 2946 /* for the /proc/TGID/task/ directories */ 2947 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 2948 { 2949 struct dentry *dentry = filp->f_path.dentry; 2950 struct inode *inode = dentry->d_inode; 2951 struct task_struct *leader = NULL; 2952 struct task_struct *task; 2953 int retval = -ENOENT; 2954 ino_t ino; 2955 int tid; 2956 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */ 2957 struct pid_namespace *ns; 2958 2959 task = get_proc_task(inode); 2960 if (!task) 2961 goto out_no_task; 2962 rcu_read_lock(); 2963 if (pid_alive(task)) { 2964 leader = task->group_leader; 2965 get_task_struct(leader); 2966 } 2967 rcu_read_unlock(); 2968 put_task_struct(task); 2969 if (!leader) 2970 goto out_no_task; 2971 retval = 0; 2972 2973 switch (pos) { 2974 case 0: 2975 ino = inode->i_ino; 2976 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0) 2977 goto out; 2978 pos++; 2979 /* fall through */ 2980 case 1: 2981 ino = parent_ino(dentry); 2982 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0) 2983 goto out; 2984 pos++; 2985 /* fall through */ 2986 } 2987 2988 /* f_version caches the tgid value that the last readdir call couldn't 2989 * return. lseek aka telldir automagically resets f_version to 0. 2990 */ 2991 ns = filp->f_dentry->d_sb->s_fs_info; 2992 tid = (int)filp->f_version; 2993 filp->f_version = 0; 2994 for (task = first_tid(leader, tid, pos - 2, ns); 2995 task; 2996 task = next_tid(task), pos++) { 2997 tid = task_pid_nr_ns(task, ns); 2998 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 2999 /* returning this tgid failed, save it as the first 3000 * pid for the next readir call */ 3001 filp->f_version = (u64)tid; 3002 put_task_struct(task); 3003 break; 3004 } 3005 } 3006 out: 3007 filp->f_pos = pos; 3008 put_task_struct(leader); 3009 out_no_task: 3010 return retval; 3011 } 3012 3013 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3014 { 3015 struct inode *inode = dentry->d_inode; 3016 struct task_struct *p = get_proc_task(inode); 3017 generic_fillattr(inode, stat); 3018 3019 if (p) { 3020 rcu_read_lock(); 3021 stat->nlink += get_nr_threads(p); 3022 rcu_read_unlock(); 3023 put_task_struct(p); 3024 } 3025 3026 return 0; 3027 } 3028 3029 static const struct inode_operations proc_task_inode_operations = { 3030 .lookup = proc_task_lookup, 3031 .getattr = proc_task_getattr, 3032 .setattr = proc_setattr, 3033 }; 3034 3035 static const struct file_operations proc_task_operations = { 3036 .read = generic_read_dir, 3037 .readdir = proc_task_readdir, 3038 }; 3039