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/fdtable.h> 60 #include <linux/string.h> 61 #include <linux/seq_file.h> 62 #include <linux/namei.h> 63 #include <linux/mnt_namespace.h> 64 #include <linux/mm.h> 65 #include <linux/rcupdate.h> 66 #include <linux/kallsyms.h> 67 #include <linux/resource.h> 68 #include <linux/module.h> 69 #include <linux/mount.h> 70 #include <linux/security.h> 71 #include <linux/ptrace.h> 72 #include <linux/cgroup.h> 73 #include <linux/cpuset.h> 74 #include <linux/audit.h> 75 #include <linux/poll.h> 76 #include <linux/nsproxy.h> 77 #include <linux/oom.h> 78 #include <linux/elf.h> 79 #include <linux/pid_namespace.h> 80 #include "internal.h" 81 82 /* NOTE: 83 * Implementing inode permission operations in /proc is almost 84 * certainly an error. Permission checks need to happen during 85 * each system call not at open time. The reason is that most of 86 * what we wish to check for permissions in /proc varies at runtime. 87 * 88 * The classic example of a problem is opening file descriptors 89 * in /proc for a task before it execs a suid executable. 90 */ 91 92 struct pid_entry { 93 char *name; 94 int len; 95 mode_t mode; 96 const struct inode_operations *iop; 97 const struct file_operations *fop; 98 union proc_op op; 99 }; 100 101 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 102 .name = (NAME), \ 103 .len = sizeof(NAME) - 1, \ 104 .mode = MODE, \ 105 .iop = IOP, \ 106 .fop = FOP, \ 107 .op = OP, \ 108 } 109 110 #define DIR(NAME, MODE, OTYPE) \ 111 NOD(NAME, (S_IFDIR|(MODE)), \ 112 &proc_##OTYPE##_inode_operations, &proc_##OTYPE##_operations, \ 113 {} ) 114 #define LNK(NAME, OTYPE) \ 115 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 116 &proc_pid_link_inode_operations, NULL, \ 117 { .proc_get_link = &proc_##OTYPE##_link } ) 118 #define REG(NAME, MODE, OTYPE) \ 119 NOD(NAME, (S_IFREG|(MODE)), NULL, \ 120 &proc_##OTYPE##_operations, {}) 121 #define INF(NAME, MODE, OTYPE) \ 122 NOD(NAME, (S_IFREG|(MODE)), \ 123 NULL, &proc_info_file_operations, \ 124 { .proc_read = &proc_##OTYPE } ) 125 #define ONE(NAME, MODE, OTYPE) \ 126 NOD(NAME, (S_IFREG|(MODE)), \ 127 NULL, &proc_single_file_operations, \ 128 { .proc_show = &proc_##OTYPE } ) 129 130 /* 131 * Count the number of hardlinks for the pid_entry table, excluding the . 132 * and .. links. 133 */ 134 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries, 135 unsigned int n) 136 { 137 unsigned int i; 138 unsigned int count; 139 140 count = 0; 141 for (i = 0; i < n; ++i) { 142 if (S_ISDIR(entries[i].mode)) 143 ++count; 144 } 145 146 return count; 147 } 148 149 int maps_protect; 150 EXPORT_SYMBOL(maps_protect); 151 152 static struct fs_struct *get_fs_struct(struct task_struct *task) 153 { 154 struct fs_struct *fs; 155 task_lock(task); 156 fs = task->fs; 157 if(fs) 158 atomic_inc(&fs->count); 159 task_unlock(task); 160 return fs; 161 } 162 163 static int get_nr_threads(struct task_struct *tsk) 164 { 165 /* Must be called with the rcu_read_lock held */ 166 unsigned long flags; 167 int count = 0; 168 169 if (lock_task_sighand(tsk, &flags)) { 170 count = atomic_read(&tsk->signal->count); 171 unlock_task_sighand(tsk, &flags); 172 } 173 return count; 174 } 175 176 static int proc_cwd_link(struct inode *inode, struct path *path) 177 { 178 struct task_struct *task = get_proc_task(inode); 179 struct fs_struct *fs = NULL; 180 int result = -ENOENT; 181 182 if (task) { 183 fs = get_fs_struct(task); 184 put_task_struct(task); 185 } 186 if (fs) { 187 read_lock(&fs->lock); 188 *path = fs->pwd; 189 path_get(&fs->pwd); 190 read_unlock(&fs->lock); 191 result = 0; 192 put_fs_struct(fs); 193 } 194 return result; 195 } 196 197 static int proc_root_link(struct inode *inode, struct path *path) 198 { 199 struct task_struct *task = get_proc_task(inode); 200 struct fs_struct *fs = NULL; 201 int result = -ENOENT; 202 203 if (task) { 204 fs = get_fs_struct(task); 205 put_task_struct(task); 206 } 207 if (fs) { 208 read_lock(&fs->lock); 209 *path = fs->root; 210 path_get(&fs->root); 211 read_unlock(&fs->lock); 212 result = 0; 213 put_fs_struct(fs); 214 } 215 return result; 216 } 217 218 /* 219 * Return zero if current may access user memory in @task, -error if not. 220 */ 221 static int check_mem_permission(struct task_struct *task) 222 { 223 /* 224 * A task can always look at itself, in case it chooses 225 * to use system calls instead of load instructions. 226 */ 227 if (task == current) 228 return 0; 229 230 /* 231 * If current is actively ptrace'ing, and would also be 232 * permitted to freshly attach with ptrace now, permit it. 233 */ 234 if (task->parent == current && (task->ptrace & PT_PTRACED) && 235 task_is_stopped_or_traced(task) && 236 ptrace_may_access(task, PTRACE_MODE_ATTACH)) 237 return 0; 238 239 /* 240 * Noone else is allowed. 241 */ 242 return -EPERM; 243 } 244 245 struct mm_struct *mm_for_maps(struct task_struct *task) 246 { 247 struct mm_struct *mm = get_task_mm(task); 248 if (!mm) 249 return NULL; 250 down_read(&mm->mmap_sem); 251 task_lock(task); 252 if (task->mm != mm) 253 goto out; 254 if (task->mm != current->mm && 255 __ptrace_may_access(task, PTRACE_MODE_READ) < 0) 256 goto out; 257 task_unlock(task); 258 return mm; 259 out: 260 task_unlock(task); 261 up_read(&mm->mmap_sem); 262 mmput(mm); 263 return NULL; 264 } 265 266 static int proc_pid_cmdline(struct task_struct *task, char * buffer) 267 { 268 int res = 0; 269 unsigned int len; 270 struct mm_struct *mm = get_task_mm(task); 271 if (!mm) 272 goto out; 273 if (!mm->arg_end) 274 goto out_mm; /* Shh! No looking before we're done */ 275 276 len = mm->arg_end - mm->arg_start; 277 278 if (len > PAGE_SIZE) 279 len = PAGE_SIZE; 280 281 res = access_process_vm(task, mm->arg_start, buffer, len, 0); 282 283 // If the nul at the end of args has been overwritten, then 284 // assume application is using setproctitle(3). 285 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) { 286 len = strnlen(buffer, res); 287 if (len < res) { 288 res = len; 289 } else { 290 len = mm->env_end - mm->env_start; 291 if (len > PAGE_SIZE - res) 292 len = PAGE_SIZE - res; 293 res += access_process_vm(task, mm->env_start, buffer+res, len, 0); 294 res = strnlen(buffer, res); 295 } 296 } 297 out_mm: 298 mmput(mm); 299 out: 300 return res; 301 } 302 303 static int proc_pid_auxv(struct task_struct *task, char *buffer) 304 { 305 int res = 0; 306 struct mm_struct *mm = get_task_mm(task); 307 if (mm) { 308 unsigned int nwords = 0; 309 do 310 nwords += 2; 311 while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 312 res = nwords * sizeof(mm->saved_auxv[0]); 313 if (res > PAGE_SIZE) 314 res = PAGE_SIZE; 315 memcpy(buffer, mm->saved_auxv, res); 316 mmput(mm); 317 } 318 return res; 319 } 320 321 322 #ifdef CONFIG_KALLSYMS 323 /* 324 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 325 * Returns the resolved symbol. If that fails, simply return the address. 326 */ 327 static int proc_pid_wchan(struct task_struct *task, char *buffer) 328 { 329 unsigned long wchan; 330 char symname[KSYM_NAME_LEN]; 331 332 wchan = get_wchan(task); 333 334 if (lookup_symbol_name(wchan, symname) < 0) 335 return sprintf(buffer, "%lu", wchan); 336 else 337 return sprintf(buffer, "%s", symname); 338 } 339 #endif /* CONFIG_KALLSYMS */ 340 341 #ifdef CONFIG_SCHEDSTATS 342 /* 343 * Provides /proc/PID/schedstat 344 */ 345 static int proc_pid_schedstat(struct task_struct *task, char *buffer) 346 { 347 return sprintf(buffer, "%llu %llu %lu\n", 348 task->sched_info.cpu_time, 349 task->sched_info.run_delay, 350 task->sched_info.pcount); 351 } 352 #endif 353 354 #ifdef CONFIG_LATENCYTOP 355 static int lstats_show_proc(struct seq_file *m, void *v) 356 { 357 int i; 358 struct inode *inode = m->private; 359 struct task_struct *task = get_proc_task(inode); 360 361 if (!task) 362 return -ESRCH; 363 seq_puts(m, "Latency Top version : v0.1\n"); 364 for (i = 0; i < 32; i++) { 365 if (task->latency_record[i].backtrace[0]) { 366 int q; 367 seq_printf(m, "%i %li %li ", 368 task->latency_record[i].count, 369 task->latency_record[i].time, 370 task->latency_record[i].max); 371 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 372 char sym[KSYM_NAME_LEN]; 373 char *c; 374 if (!task->latency_record[i].backtrace[q]) 375 break; 376 if (task->latency_record[i].backtrace[q] == ULONG_MAX) 377 break; 378 sprint_symbol(sym, task->latency_record[i].backtrace[q]); 379 c = strchr(sym, '+'); 380 if (c) 381 *c = 0; 382 seq_printf(m, "%s ", sym); 383 } 384 seq_printf(m, "\n"); 385 } 386 387 } 388 put_task_struct(task); 389 return 0; 390 } 391 392 static int lstats_open(struct inode *inode, struct file *file) 393 { 394 return single_open(file, lstats_show_proc, inode); 395 } 396 397 static ssize_t lstats_write(struct file *file, const char __user *buf, 398 size_t count, loff_t *offs) 399 { 400 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 401 402 if (!task) 403 return -ESRCH; 404 clear_all_latency_tracing(task); 405 put_task_struct(task); 406 407 return count; 408 } 409 410 static const struct file_operations proc_lstats_operations = { 411 .open = lstats_open, 412 .read = seq_read, 413 .write = lstats_write, 414 .llseek = seq_lseek, 415 .release = single_release, 416 }; 417 418 #endif 419 420 /* The badness from the OOM killer */ 421 unsigned long badness(struct task_struct *p, unsigned long uptime); 422 static int proc_oom_score(struct task_struct *task, char *buffer) 423 { 424 unsigned long points; 425 struct timespec uptime; 426 427 do_posix_clock_monotonic_gettime(&uptime); 428 read_lock(&tasklist_lock); 429 points = badness(task, uptime.tv_sec); 430 read_unlock(&tasklist_lock); 431 return sprintf(buffer, "%lu\n", points); 432 } 433 434 struct limit_names { 435 char *name; 436 char *unit; 437 }; 438 439 static const struct limit_names lnames[RLIM_NLIMITS] = { 440 [RLIMIT_CPU] = {"Max cpu time", "ms"}, 441 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 442 [RLIMIT_DATA] = {"Max data size", "bytes"}, 443 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 444 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 445 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 446 [RLIMIT_NPROC] = {"Max processes", "processes"}, 447 [RLIMIT_NOFILE] = {"Max open files", "files"}, 448 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 449 [RLIMIT_AS] = {"Max address space", "bytes"}, 450 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 451 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 452 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 453 [RLIMIT_NICE] = {"Max nice priority", NULL}, 454 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 455 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 456 }; 457 458 /* Display limits for a process */ 459 static int proc_pid_limits(struct task_struct *task, char *buffer) 460 { 461 unsigned int i; 462 int count = 0; 463 unsigned long flags; 464 char *bufptr = buffer; 465 466 struct rlimit rlim[RLIM_NLIMITS]; 467 468 rcu_read_lock(); 469 if (!lock_task_sighand(task,&flags)) { 470 rcu_read_unlock(); 471 return 0; 472 } 473 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 474 unlock_task_sighand(task, &flags); 475 rcu_read_unlock(); 476 477 /* 478 * print the file header 479 */ 480 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n", 481 "Limit", "Soft Limit", "Hard Limit", "Units"); 482 483 for (i = 0; i < RLIM_NLIMITS; i++) { 484 if (rlim[i].rlim_cur == RLIM_INFINITY) 485 count += sprintf(&bufptr[count], "%-25s %-20s ", 486 lnames[i].name, "unlimited"); 487 else 488 count += sprintf(&bufptr[count], "%-25s %-20lu ", 489 lnames[i].name, rlim[i].rlim_cur); 490 491 if (rlim[i].rlim_max == RLIM_INFINITY) 492 count += sprintf(&bufptr[count], "%-20s ", "unlimited"); 493 else 494 count += sprintf(&bufptr[count], "%-20lu ", 495 rlim[i].rlim_max); 496 497 if (lnames[i].unit) 498 count += sprintf(&bufptr[count], "%-10s\n", 499 lnames[i].unit); 500 else 501 count += sprintf(&bufptr[count], "\n"); 502 } 503 504 return count; 505 } 506 507 /************************************************************************/ 508 /* Here the fs part begins */ 509 /************************************************************************/ 510 511 /* permission checks */ 512 static int proc_fd_access_allowed(struct inode *inode) 513 { 514 struct task_struct *task; 515 int allowed = 0; 516 /* Allow access to a task's file descriptors if it is us or we 517 * may use ptrace attach to the process and find out that 518 * information. 519 */ 520 task = get_proc_task(inode); 521 if (task) { 522 allowed = ptrace_may_access(task, PTRACE_MODE_READ); 523 put_task_struct(task); 524 } 525 return allowed; 526 } 527 528 static int proc_setattr(struct dentry *dentry, struct iattr *attr) 529 { 530 int error; 531 struct inode *inode = dentry->d_inode; 532 533 if (attr->ia_valid & ATTR_MODE) 534 return -EPERM; 535 536 error = inode_change_ok(inode, attr); 537 if (!error) 538 error = inode_setattr(inode, attr); 539 return error; 540 } 541 542 static const struct inode_operations proc_def_inode_operations = { 543 .setattr = proc_setattr, 544 }; 545 546 static int mounts_open_common(struct inode *inode, struct file *file, 547 const struct seq_operations *op) 548 { 549 struct task_struct *task = get_proc_task(inode); 550 struct nsproxy *nsp; 551 struct mnt_namespace *ns = NULL; 552 struct fs_struct *fs = NULL; 553 struct path root; 554 struct proc_mounts *p; 555 int ret = -EINVAL; 556 557 if (task) { 558 rcu_read_lock(); 559 nsp = task_nsproxy(task); 560 if (nsp) { 561 ns = nsp->mnt_ns; 562 if (ns) 563 get_mnt_ns(ns); 564 } 565 rcu_read_unlock(); 566 if (ns) 567 fs = get_fs_struct(task); 568 put_task_struct(task); 569 } 570 571 if (!ns) 572 goto err; 573 if (!fs) 574 goto err_put_ns; 575 576 read_lock(&fs->lock); 577 root = fs->root; 578 path_get(&root); 579 read_unlock(&fs->lock); 580 put_fs_struct(fs); 581 582 ret = -ENOMEM; 583 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL); 584 if (!p) 585 goto err_put_path; 586 587 file->private_data = &p->m; 588 ret = seq_open(file, op); 589 if (ret) 590 goto err_free; 591 592 p->m.private = p; 593 p->ns = ns; 594 p->root = root; 595 p->event = ns->event; 596 597 return 0; 598 599 err_free: 600 kfree(p); 601 err_put_path: 602 path_put(&root); 603 err_put_ns: 604 put_mnt_ns(ns); 605 err: 606 return ret; 607 } 608 609 static int mounts_release(struct inode *inode, struct file *file) 610 { 611 struct proc_mounts *p = file->private_data; 612 path_put(&p->root); 613 put_mnt_ns(p->ns); 614 return seq_release(inode, file); 615 } 616 617 static unsigned mounts_poll(struct file *file, poll_table *wait) 618 { 619 struct proc_mounts *p = file->private_data; 620 struct mnt_namespace *ns = p->ns; 621 unsigned res = 0; 622 623 poll_wait(file, &ns->poll, wait); 624 625 spin_lock(&vfsmount_lock); 626 if (p->event != ns->event) { 627 p->event = ns->event; 628 res = POLLERR; 629 } 630 spin_unlock(&vfsmount_lock); 631 632 return res; 633 } 634 635 static int mounts_open(struct inode *inode, struct file *file) 636 { 637 return mounts_open_common(inode, file, &mounts_op); 638 } 639 640 static const struct file_operations proc_mounts_operations = { 641 .open = mounts_open, 642 .read = seq_read, 643 .llseek = seq_lseek, 644 .release = mounts_release, 645 .poll = mounts_poll, 646 }; 647 648 static int mountinfo_open(struct inode *inode, struct file *file) 649 { 650 return mounts_open_common(inode, file, &mountinfo_op); 651 } 652 653 static const struct file_operations proc_mountinfo_operations = { 654 .open = mountinfo_open, 655 .read = seq_read, 656 .llseek = seq_lseek, 657 .release = mounts_release, 658 .poll = mounts_poll, 659 }; 660 661 static int mountstats_open(struct inode *inode, struct file *file) 662 { 663 return mounts_open_common(inode, file, &mountstats_op); 664 } 665 666 static const struct file_operations proc_mountstats_operations = { 667 .open = mountstats_open, 668 .read = seq_read, 669 .llseek = seq_lseek, 670 .release = mounts_release, 671 }; 672 673 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */ 674 675 static ssize_t proc_info_read(struct file * file, char __user * buf, 676 size_t count, loff_t *ppos) 677 { 678 struct inode * inode = file->f_path.dentry->d_inode; 679 unsigned long page; 680 ssize_t length; 681 struct task_struct *task = get_proc_task(inode); 682 683 length = -ESRCH; 684 if (!task) 685 goto out_no_task; 686 687 if (count > PROC_BLOCK_SIZE) 688 count = PROC_BLOCK_SIZE; 689 690 length = -ENOMEM; 691 if (!(page = __get_free_page(GFP_TEMPORARY))) 692 goto out; 693 694 length = PROC_I(inode)->op.proc_read(task, (char*)page); 695 696 if (length >= 0) 697 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length); 698 free_page(page); 699 out: 700 put_task_struct(task); 701 out_no_task: 702 return length; 703 } 704 705 static const struct file_operations proc_info_file_operations = { 706 .read = proc_info_read, 707 }; 708 709 static int proc_single_show(struct seq_file *m, void *v) 710 { 711 struct inode *inode = m->private; 712 struct pid_namespace *ns; 713 struct pid *pid; 714 struct task_struct *task; 715 int ret; 716 717 ns = inode->i_sb->s_fs_info; 718 pid = proc_pid(inode); 719 task = get_pid_task(pid, PIDTYPE_PID); 720 if (!task) 721 return -ESRCH; 722 723 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 724 725 put_task_struct(task); 726 return ret; 727 } 728 729 static int proc_single_open(struct inode *inode, struct file *filp) 730 { 731 int ret; 732 ret = single_open(filp, proc_single_show, NULL); 733 if (!ret) { 734 struct seq_file *m = filp->private_data; 735 736 m->private = inode; 737 } 738 return ret; 739 } 740 741 static const struct file_operations proc_single_file_operations = { 742 .open = proc_single_open, 743 .read = seq_read, 744 .llseek = seq_lseek, 745 .release = single_release, 746 }; 747 748 static int mem_open(struct inode* inode, struct file* file) 749 { 750 file->private_data = (void*)((long)current->self_exec_id); 751 return 0; 752 } 753 754 static ssize_t mem_read(struct file * file, char __user * buf, 755 size_t count, loff_t *ppos) 756 { 757 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 758 char *page; 759 unsigned long src = *ppos; 760 int ret = -ESRCH; 761 struct mm_struct *mm; 762 763 if (!task) 764 goto out_no_task; 765 766 if (check_mem_permission(task)) 767 goto out; 768 769 ret = -ENOMEM; 770 page = (char *)__get_free_page(GFP_TEMPORARY); 771 if (!page) 772 goto out; 773 774 ret = 0; 775 776 mm = get_task_mm(task); 777 if (!mm) 778 goto out_free; 779 780 ret = -EIO; 781 782 if (file->private_data != (void*)((long)current->self_exec_id)) 783 goto out_put; 784 785 ret = 0; 786 787 while (count > 0) { 788 int this_len, retval; 789 790 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 791 retval = access_process_vm(task, src, page, this_len, 0); 792 if (!retval || check_mem_permission(task)) { 793 if (!ret) 794 ret = -EIO; 795 break; 796 } 797 798 if (copy_to_user(buf, page, retval)) { 799 ret = -EFAULT; 800 break; 801 } 802 803 ret += retval; 804 src += retval; 805 buf += retval; 806 count -= retval; 807 } 808 *ppos = src; 809 810 out_put: 811 mmput(mm); 812 out_free: 813 free_page((unsigned long) page); 814 out: 815 put_task_struct(task); 816 out_no_task: 817 return ret; 818 } 819 820 #define mem_write NULL 821 822 #ifndef mem_write 823 /* This is a security hazard */ 824 static ssize_t mem_write(struct file * file, const char __user *buf, 825 size_t count, loff_t *ppos) 826 { 827 int copied; 828 char *page; 829 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 830 unsigned long dst = *ppos; 831 832 copied = -ESRCH; 833 if (!task) 834 goto out_no_task; 835 836 if (check_mem_permission(task)) 837 goto out; 838 839 copied = -ENOMEM; 840 page = (char *)__get_free_page(GFP_TEMPORARY); 841 if (!page) 842 goto out; 843 844 copied = 0; 845 while (count > 0) { 846 int this_len, retval; 847 848 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 849 if (copy_from_user(page, buf, this_len)) { 850 copied = -EFAULT; 851 break; 852 } 853 retval = access_process_vm(task, dst, page, this_len, 1); 854 if (!retval) { 855 if (!copied) 856 copied = -EIO; 857 break; 858 } 859 copied += retval; 860 buf += retval; 861 dst += retval; 862 count -= retval; 863 } 864 *ppos = dst; 865 free_page((unsigned long) page); 866 out: 867 put_task_struct(task); 868 out_no_task: 869 return copied; 870 } 871 #endif 872 873 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 874 { 875 switch (orig) { 876 case 0: 877 file->f_pos = offset; 878 break; 879 case 1: 880 file->f_pos += offset; 881 break; 882 default: 883 return -EINVAL; 884 } 885 force_successful_syscall_return(); 886 return file->f_pos; 887 } 888 889 static const struct file_operations proc_mem_operations = { 890 .llseek = mem_lseek, 891 .read = mem_read, 892 .write = mem_write, 893 .open = mem_open, 894 }; 895 896 static ssize_t environ_read(struct file *file, char __user *buf, 897 size_t count, loff_t *ppos) 898 { 899 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 900 char *page; 901 unsigned long src = *ppos; 902 int ret = -ESRCH; 903 struct mm_struct *mm; 904 905 if (!task) 906 goto out_no_task; 907 908 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 909 goto out; 910 911 ret = -ENOMEM; 912 page = (char *)__get_free_page(GFP_TEMPORARY); 913 if (!page) 914 goto out; 915 916 ret = 0; 917 918 mm = get_task_mm(task); 919 if (!mm) 920 goto out_free; 921 922 while (count > 0) { 923 int this_len, retval, max_len; 924 925 this_len = mm->env_end - (mm->env_start + src); 926 927 if (this_len <= 0) 928 break; 929 930 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 931 this_len = (this_len > max_len) ? max_len : this_len; 932 933 retval = access_process_vm(task, (mm->env_start + src), 934 page, this_len, 0); 935 936 if (retval <= 0) { 937 ret = retval; 938 break; 939 } 940 941 if (copy_to_user(buf, page, retval)) { 942 ret = -EFAULT; 943 break; 944 } 945 946 ret += retval; 947 src += retval; 948 buf += retval; 949 count -= retval; 950 } 951 *ppos = src; 952 953 mmput(mm); 954 out_free: 955 free_page((unsigned long) page); 956 out: 957 put_task_struct(task); 958 out_no_task: 959 return ret; 960 } 961 962 static const struct file_operations proc_environ_operations = { 963 .read = environ_read, 964 }; 965 966 static ssize_t oom_adjust_read(struct file *file, char __user *buf, 967 size_t count, loff_t *ppos) 968 { 969 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 970 char buffer[PROC_NUMBUF]; 971 size_t len; 972 int oom_adjust; 973 974 if (!task) 975 return -ESRCH; 976 oom_adjust = task->oomkilladj; 977 put_task_struct(task); 978 979 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); 980 981 return simple_read_from_buffer(buf, count, ppos, buffer, len); 982 } 983 984 static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 985 size_t count, loff_t *ppos) 986 { 987 struct task_struct *task; 988 char buffer[PROC_NUMBUF], *end; 989 int oom_adjust; 990 991 memset(buffer, 0, sizeof(buffer)); 992 if (count > sizeof(buffer) - 1) 993 count = sizeof(buffer) - 1; 994 if (copy_from_user(buffer, buf, count)) 995 return -EFAULT; 996 oom_adjust = simple_strtol(buffer, &end, 0); 997 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && 998 oom_adjust != OOM_DISABLE) 999 return -EINVAL; 1000 if (*end == '\n') 1001 end++; 1002 task = get_proc_task(file->f_path.dentry->d_inode); 1003 if (!task) 1004 return -ESRCH; 1005 if (oom_adjust < task->oomkilladj && !capable(CAP_SYS_RESOURCE)) { 1006 put_task_struct(task); 1007 return -EACCES; 1008 } 1009 task->oomkilladj = oom_adjust; 1010 put_task_struct(task); 1011 if (end - buffer == 0) 1012 return -EIO; 1013 return end - buffer; 1014 } 1015 1016 static const struct file_operations proc_oom_adjust_operations = { 1017 .read = oom_adjust_read, 1018 .write = oom_adjust_write, 1019 }; 1020 1021 #ifdef CONFIG_AUDITSYSCALL 1022 #define TMPBUFLEN 21 1023 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1024 size_t count, loff_t *ppos) 1025 { 1026 struct inode * inode = file->f_path.dentry->d_inode; 1027 struct task_struct *task = get_proc_task(inode); 1028 ssize_t length; 1029 char tmpbuf[TMPBUFLEN]; 1030 1031 if (!task) 1032 return -ESRCH; 1033 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1034 audit_get_loginuid(task)); 1035 put_task_struct(task); 1036 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1037 } 1038 1039 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1040 size_t count, loff_t *ppos) 1041 { 1042 struct inode * inode = file->f_path.dentry->d_inode; 1043 char *page, *tmp; 1044 ssize_t length; 1045 uid_t loginuid; 1046 1047 if (!capable(CAP_AUDIT_CONTROL)) 1048 return -EPERM; 1049 1050 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) 1051 return -EPERM; 1052 1053 if (count >= PAGE_SIZE) 1054 count = PAGE_SIZE - 1; 1055 1056 if (*ppos != 0) { 1057 /* No partial writes. */ 1058 return -EINVAL; 1059 } 1060 page = (char*)__get_free_page(GFP_TEMPORARY); 1061 if (!page) 1062 return -ENOMEM; 1063 length = -EFAULT; 1064 if (copy_from_user(page, buf, count)) 1065 goto out_free_page; 1066 1067 page[count] = '\0'; 1068 loginuid = simple_strtoul(page, &tmp, 10); 1069 if (tmp == page) { 1070 length = -EINVAL; 1071 goto out_free_page; 1072 1073 } 1074 length = audit_set_loginuid(current, loginuid); 1075 if (likely(length == 0)) 1076 length = count; 1077 1078 out_free_page: 1079 free_page((unsigned long) page); 1080 return length; 1081 } 1082 1083 static const struct file_operations proc_loginuid_operations = { 1084 .read = proc_loginuid_read, 1085 .write = proc_loginuid_write, 1086 }; 1087 1088 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1089 size_t count, loff_t *ppos) 1090 { 1091 struct inode * inode = file->f_path.dentry->d_inode; 1092 struct task_struct *task = get_proc_task(inode); 1093 ssize_t length; 1094 char tmpbuf[TMPBUFLEN]; 1095 1096 if (!task) 1097 return -ESRCH; 1098 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1099 audit_get_sessionid(task)); 1100 put_task_struct(task); 1101 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1102 } 1103 1104 static const struct file_operations proc_sessionid_operations = { 1105 .read = proc_sessionid_read, 1106 }; 1107 #endif 1108 1109 #ifdef CONFIG_FAULT_INJECTION 1110 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1111 size_t count, loff_t *ppos) 1112 { 1113 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1114 char buffer[PROC_NUMBUF]; 1115 size_t len; 1116 int make_it_fail; 1117 1118 if (!task) 1119 return -ESRCH; 1120 make_it_fail = task->make_it_fail; 1121 put_task_struct(task); 1122 1123 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1124 1125 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1126 } 1127 1128 static ssize_t proc_fault_inject_write(struct file * file, 1129 const char __user * buf, size_t count, loff_t *ppos) 1130 { 1131 struct task_struct *task; 1132 char buffer[PROC_NUMBUF], *end; 1133 int make_it_fail; 1134 1135 if (!capable(CAP_SYS_RESOURCE)) 1136 return -EPERM; 1137 memset(buffer, 0, sizeof(buffer)); 1138 if (count > sizeof(buffer) - 1) 1139 count = sizeof(buffer) - 1; 1140 if (copy_from_user(buffer, buf, count)) 1141 return -EFAULT; 1142 make_it_fail = simple_strtol(buffer, &end, 0); 1143 if (*end == '\n') 1144 end++; 1145 task = get_proc_task(file->f_dentry->d_inode); 1146 if (!task) 1147 return -ESRCH; 1148 task->make_it_fail = make_it_fail; 1149 put_task_struct(task); 1150 if (end - buffer == 0) 1151 return -EIO; 1152 return end - buffer; 1153 } 1154 1155 static const struct file_operations proc_fault_inject_operations = { 1156 .read = proc_fault_inject_read, 1157 .write = proc_fault_inject_write, 1158 }; 1159 #endif 1160 1161 1162 #ifdef CONFIG_SCHED_DEBUG 1163 /* 1164 * Print out various scheduling related per-task fields: 1165 */ 1166 static int sched_show(struct seq_file *m, void *v) 1167 { 1168 struct inode *inode = m->private; 1169 struct task_struct *p; 1170 1171 WARN_ON(!inode); 1172 1173 p = get_proc_task(inode); 1174 if (!p) 1175 return -ESRCH; 1176 proc_sched_show_task(p, m); 1177 1178 put_task_struct(p); 1179 1180 return 0; 1181 } 1182 1183 static ssize_t 1184 sched_write(struct file *file, const char __user *buf, 1185 size_t count, loff_t *offset) 1186 { 1187 struct inode *inode = file->f_path.dentry->d_inode; 1188 struct task_struct *p; 1189 1190 WARN_ON(!inode); 1191 1192 p = get_proc_task(inode); 1193 if (!p) 1194 return -ESRCH; 1195 proc_sched_set_task(p); 1196 1197 put_task_struct(p); 1198 1199 return count; 1200 } 1201 1202 static int sched_open(struct inode *inode, struct file *filp) 1203 { 1204 int ret; 1205 1206 ret = single_open(filp, sched_show, NULL); 1207 if (!ret) { 1208 struct seq_file *m = filp->private_data; 1209 1210 m->private = inode; 1211 } 1212 return ret; 1213 } 1214 1215 static const struct file_operations proc_pid_sched_operations = { 1216 .open = sched_open, 1217 .read = seq_read, 1218 .write = sched_write, 1219 .llseek = seq_lseek, 1220 .release = single_release, 1221 }; 1222 1223 #endif 1224 1225 /* 1226 * We added or removed a vma mapping the executable. The vmas are only mapped 1227 * during exec and are not mapped with the mmap system call. 1228 * Callers must hold down_write() on the mm's mmap_sem for these 1229 */ 1230 void added_exe_file_vma(struct mm_struct *mm) 1231 { 1232 mm->num_exe_file_vmas++; 1233 } 1234 1235 void removed_exe_file_vma(struct mm_struct *mm) 1236 { 1237 mm->num_exe_file_vmas--; 1238 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){ 1239 fput(mm->exe_file); 1240 mm->exe_file = NULL; 1241 } 1242 1243 } 1244 1245 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) 1246 { 1247 if (new_exe_file) 1248 get_file(new_exe_file); 1249 if (mm->exe_file) 1250 fput(mm->exe_file); 1251 mm->exe_file = new_exe_file; 1252 mm->num_exe_file_vmas = 0; 1253 } 1254 1255 struct file *get_mm_exe_file(struct mm_struct *mm) 1256 { 1257 struct file *exe_file; 1258 1259 /* We need mmap_sem to protect against races with removal of 1260 * VM_EXECUTABLE vmas */ 1261 down_read(&mm->mmap_sem); 1262 exe_file = mm->exe_file; 1263 if (exe_file) 1264 get_file(exe_file); 1265 up_read(&mm->mmap_sem); 1266 return exe_file; 1267 } 1268 1269 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm) 1270 { 1271 /* It's safe to write the exe_file pointer without exe_file_lock because 1272 * this is called during fork when the task is not yet in /proc */ 1273 newmm->exe_file = get_mm_exe_file(oldmm); 1274 } 1275 1276 static int proc_exe_link(struct inode *inode, struct path *exe_path) 1277 { 1278 struct task_struct *task; 1279 struct mm_struct *mm; 1280 struct file *exe_file; 1281 1282 task = get_proc_task(inode); 1283 if (!task) 1284 return -ENOENT; 1285 mm = get_task_mm(task); 1286 put_task_struct(task); 1287 if (!mm) 1288 return -ENOENT; 1289 exe_file = get_mm_exe_file(mm); 1290 mmput(mm); 1291 if (exe_file) { 1292 *exe_path = exe_file->f_path; 1293 path_get(&exe_file->f_path); 1294 fput(exe_file); 1295 return 0; 1296 } else 1297 return -ENOENT; 1298 } 1299 1300 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1301 { 1302 struct inode *inode = dentry->d_inode; 1303 int error = -EACCES; 1304 1305 /* We don't need a base pointer in the /proc filesystem */ 1306 path_put(&nd->path); 1307 1308 /* Are we allowed to snoop on the tasks file descriptors? */ 1309 if (!proc_fd_access_allowed(inode)) 1310 goto out; 1311 1312 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path); 1313 nd->last_type = LAST_BIND; 1314 out: 1315 return ERR_PTR(error); 1316 } 1317 1318 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1319 { 1320 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1321 char *pathname; 1322 int len; 1323 1324 if (!tmp) 1325 return -ENOMEM; 1326 1327 pathname = d_path(path, tmp, PAGE_SIZE); 1328 len = PTR_ERR(pathname); 1329 if (IS_ERR(pathname)) 1330 goto out; 1331 len = tmp + PAGE_SIZE - 1 - pathname; 1332 1333 if (len > buflen) 1334 len = buflen; 1335 if (copy_to_user(buffer, pathname, len)) 1336 len = -EFAULT; 1337 out: 1338 free_page((unsigned long)tmp); 1339 return len; 1340 } 1341 1342 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1343 { 1344 int error = -EACCES; 1345 struct inode *inode = dentry->d_inode; 1346 struct path path; 1347 1348 /* Are we allowed to snoop on the tasks file descriptors? */ 1349 if (!proc_fd_access_allowed(inode)) 1350 goto out; 1351 1352 error = PROC_I(inode)->op.proc_get_link(inode, &path); 1353 if (error) 1354 goto out; 1355 1356 error = do_proc_readlink(&path, buffer, buflen); 1357 path_put(&path); 1358 out: 1359 return error; 1360 } 1361 1362 static const struct inode_operations proc_pid_link_inode_operations = { 1363 .readlink = proc_pid_readlink, 1364 .follow_link = proc_pid_follow_link, 1365 .setattr = proc_setattr, 1366 }; 1367 1368 1369 /* building an inode */ 1370 1371 static int task_dumpable(struct task_struct *task) 1372 { 1373 int dumpable = 0; 1374 struct mm_struct *mm; 1375 1376 task_lock(task); 1377 mm = task->mm; 1378 if (mm) 1379 dumpable = get_dumpable(mm); 1380 task_unlock(task); 1381 if(dumpable == 1) 1382 return 1; 1383 return 0; 1384 } 1385 1386 1387 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1388 { 1389 struct inode * inode; 1390 struct proc_inode *ei; 1391 1392 /* We need a new inode */ 1393 1394 inode = new_inode(sb); 1395 if (!inode) 1396 goto out; 1397 1398 /* Common stuff */ 1399 ei = PROC_I(inode); 1400 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1401 inode->i_op = &proc_def_inode_operations; 1402 1403 /* 1404 * grab the reference to task. 1405 */ 1406 ei->pid = get_task_pid(task, PIDTYPE_PID); 1407 if (!ei->pid) 1408 goto out_unlock; 1409 1410 inode->i_uid = 0; 1411 inode->i_gid = 0; 1412 if (task_dumpable(task)) { 1413 inode->i_uid = task->euid; 1414 inode->i_gid = task->egid; 1415 } 1416 security_task_to_inode(task, inode); 1417 1418 out: 1419 return inode; 1420 1421 out_unlock: 1422 iput(inode); 1423 return NULL; 1424 } 1425 1426 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1427 { 1428 struct inode *inode = dentry->d_inode; 1429 struct task_struct *task; 1430 generic_fillattr(inode, stat); 1431 1432 rcu_read_lock(); 1433 stat->uid = 0; 1434 stat->gid = 0; 1435 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1436 if (task) { 1437 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1438 task_dumpable(task)) { 1439 stat->uid = task->euid; 1440 stat->gid = task->egid; 1441 } 1442 } 1443 rcu_read_unlock(); 1444 return 0; 1445 } 1446 1447 /* dentry stuff */ 1448 1449 /* 1450 * Exceptional case: normally we are not allowed to unhash a busy 1451 * directory. In this case, however, we can do it - no aliasing problems 1452 * due to the way we treat inodes. 1453 * 1454 * Rewrite the inode's ownerships here because the owning task may have 1455 * performed a setuid(), etc. 1456 * 1457 * Before the /proc/pid/status file was created the only way to read 1458 * the effective uid of a /process was to stat /proc/pid. Reading 1459 * /proc/pid/status is slow enough that procps and other packages 1460 * kept stating /proc/pid. To keep the rules in /proc simple I have 1461 * made this apply to all per process world readable and executable 1462 * directories. 1463 */ 1464 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1465 { 1466 struct inode *inode = dentry->d_inode; 1467 struct task_struct *task = get_proc_task(inode); 1468 if (task) { 1469 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1470 task_dumpable(task)) { 1471 inode->i_uid = task->euid; 1472 inode->i_gid = task->egid; 1473 } else { 1474 inode->i_uid = 0; 1475 inode->i_gid = 0; 1476 } 1477 inode->i_mode &= ~(S_ISUID | S_ISGID); 1478 security_task_to_inode(task, inode); 1479 put_task_struct(task); 1480 return 1; 1481 } 1482 d_drop(dentry); 1483 return 0; 1484 } 1485 1486 static int pid_delete_dentry(struct dentry * dentry) 1487 { 1488 /* Is the task we represent dead? 1489 * If so, then don't put the dentry on the lru list, 1490 * kill it immediately. 1491 */ 1492 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1493 } 1494 1495 static struct dentry_operations pid_dentry_operations = 1496 { 1497 .d_revalidate = pid_revalidate, 1498 .d_delete = pid_delete_dentry, 1499 }; 1500 1501 /* Lookups */ 1502 1503 typedef struct dentry *instantiate_t(struct inode *, struct dentry *, 1504 struct task_struct *, const void *); 1505 1506 /* 1507 * Fill a directory entry. 1508 * 1509 * If possible create the dcache entry and derive our inode number and 1510 * file type from dcache entry. 1511 * 1512 * Since all of the proc inode numbers are dynamically generated, the inode 1513 * numbers do not exist until the inode is cache. This means creating the 1514 * the dcache entry in readdir is necessary to keep the inode numbers 1515 * reported by readdir in sync with the inode numbers reported 1516 * by stat. 1517 */ 1518 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1519 char *name, int len, 1520 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1521 { 1522 struct dentry *child, *dir = filp->f_path.dentry; 1523 struct inode *inode; 1524 struct qstr qname; 1525 ino_t ino = 0; 1526 unsigned type = DT_UNKNOWN; 1527 1528 qname.name = name; 1529 qname.len = len; 1530 qname.hash = full_name_hash(name, len); 1531 1532 child = d_lookup(dir, &qname); 1533 if (!child) { 1534 struct dentry *new; 1535 new = d_alloc(dir, &qname); 1536 if (new) { 1537 child = instantiate(dir->d_inode, new, task, ptr); 1538 if (child) 1539 dput(new); 1540 else 1541 child = new; 1542 } 1543 } 1544 if (!child || IS_ERR(child) || !child->d_inode) 1545 goto end_instantiate; 1546 inode = child->d_inode; 1547 if (inode) { 1548 ino = inode->i_ino; 1549 type = inode->i_mode >> 12; 1550 } 1551 dput(child); 1552 end_instantiate: 1553 if (!ino) 1554 ino = find_inode_number(dir, &qname); 1555 if (!ino) 1556 ino = 1; 1557 return filldir(dirent, name, len, filp->f_pos, ino, type); 1558 } 1559 1560 static unsigned name_to_int(struct dentry *dentry) 1561 { 1562 const char *name = dentry->d_name.name; 1563 int len = dentry->d_name.len; 1564 unsigned n = 0; 1565 1566 if (len > 1 && *name == '0') 1567 goto out; 1568 while (len-- > 0) { 1569 unsigned c = *name++ - '0'; 1570 if (c > 9) 1571 goto out; 1572 if (n >= (~0U-9)/10) 1573 goto out; 1574 n *= 10; 1575 n += c; 1576 } 1577 return n; 1578 out: 1579 return ~0U; 1580 } 1581 1582 #define PROC_FDINFO_MAX 64 1583 1584 static int proc_fd_info(struct inode *inode, struct path *path, char *info) 1585 { 1586 struct task_struct *task = get_proc_task(inode); 1587 struct files_struct *files = NULL; 1588 struct file *file; 1589 int fd = proc_fd(inode); 1590 1591 if (task) { 1592 files = get_files_struct(task); 1593 put_task_struct(task); 1594 } 1595 if (files) { 1596 /* 1597 * We are not taking a ref to the file structure, so we must 1598 * hold ->file_lock. 1599 */ 1600 spin_lock(&files->file_lock); 1601 file = fcheck_files(files, fd); 1602 if (file) { 1603 if (path) { 1604 *path = file->f_path; 1605 path_get(&file->f_path); 1606 } 1607 if (info) 1608 snprintf(info, PROC_FDINFO_MAX, 1609 "pos:\t%lli\n" 1610 "flags:\t0%o\n", 1611 (long long) file->f_pos, 1612 file->f_flags); 1613 spin_unlock(&files->file_lock); 1614 put_files_struct(files); 1615 return 0; 1616 } 1617 spin_unlock(&files->file_lock); 1618 put_files_struct(files); 1619 } 1620 return -ENOENT; 1621 } 1622 1623 static int proc_fd_link(struct inode *inode, struct path *path) 1624 { 1625 return proc_fd_info(inode, path, NULL); 1626 } 1627 1628 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1629 { 1630 struct inode *inode = dentry->d_inode; 1631 struct task_struct *task = get_proc_task(inode); 1632 int fd = proc_fd(inode); 1633 struct files_struct *files; 1634 1635 if (task) { 1636 files = get_files_struct(task); 1637 if (files) { 1638 rcu_read_lock(); 1639 if (fcheck_files(files, fd)) { 1640 rcu_read_unlock(); 1641 put_files_struct(files); 1642 if (task_dumpable(task)) { 1643 inode->i_uid = task->euid; 1644 inode->i_gid = task->egid; 1645 } else { 1646 inode->i_uid = 0; 1647 inode->i_gid = 0; 1648 } 1649 inode->i_mode &= ~(S_ISUID | S_ISGID); 1650 security_task_to_inode(task, inode); 1651 put_task_struct(task); 1652 return 1; 1653 } 1654 rcu_read_unlock(); 1655 put_files_struct(files); 1656 } 1657 put_task_struct(task); 1658 } 1659 d_drop(dentry); 1660 return 0; 1661 } 1662 1663 static struct dentry_operations tid_fd_dentry_operations = 1664 { 1665 .d_revalidate = tid_fd_revalidate, 1666 .d_delete = pid_delete_dentry, 1667 }; 1668 1669 static struct dentry *proc_fd_instantiate(struct inode *dir, 1670 struct dentry *dentry, struct task_struct *task, const void *ptr) 1671 { 1672 unsigned fd = *(const unsigned *)ptr; 1673 struct file *file; 1674 struct files_struct *files; 1675 struct inode *inode; 1676 struct proc_inode *ei; 1677 struct dentry *error = ERR_PTR(-ENOENT); 1678 1679 inode = proc_pid_make_inode(dir->i_sb, task); 1680 if (!inode) 1681 goto out; 1682 ei = PROC_I(inode); 1683 ei->fd = fd; 1684 files = get_files_struct(task); 1685 if (!files) 1686 goto out_iput; 1687 inode->i_mode = S_IFLNK; 1688 1689 /* 1690 * We are not taking a ref to the file structure, so we must 1691 * hold ->file_lock. 1692 */ 1693 spin_lock(&files->file_lock); 1694 file = fcheck_files(files, fd); 1695 if (!file) 1696 goto out_unlock; 1697 if (file->f_mode & 1) 1698 inode->i_mode |= S_IRUSR | S_IXUSR; 1699 if (file->f_mode & 2) 1700 inode->i_mode |= S_IWUSR | S_IXUSR; 1701 spin_unlock(&files->file_lock); 1702 put_files_struct(files); 1703 1704 inode->i_op = &proc_pid_link_inode_operations; 1705 inode->i_size = 64; 1706 ei->op.proc_get_link = proc_fd_link; 1707 dentry->d_op = &tid_fd_dentry_operations; 1708 d_add(dentry, inode); 1709 /* Close the race of the process dying before we return the dentry */ 1710 if (tid_fd_revalidate(dentry, NULL)) 1711 error = NULL; 1712 1713 out: 1714 return error; 1715 out_unlock: 1716 spin_unlock(&files->file_lock); 1717 put_files_struct(files); 1718 out_iput: 1719 iput(inode); 1720 goto out; 1721 } 1722 1723 static struct dentry *proc_lookupfd_common(struct inode *dir, 1724 struct dentry *dentry, 1725 instantiate_t instantiate) 1726 { 1727 struct task_struct *task = get_proc_task(dir); 1728 unsigned fd = name_to_int(dentry); 1729 struct dentry *result = ERR_PTR(-ENOENT); 1730 1731 if (!task) 1732 goto out_no_task; 1733 if (fd == ~0U) 1734 goto out; 1735 1736 result = instantiate(dir, dentry, task, &fd); 1737 out: 1738 put_task_struct(task); 1739 out_no_task: 1740 return result; 1741 } 1742 1743 static int proc_readfd_common(struct file * filp, void * dirent, 1744 filldir_t filldir, instantiate_t instantiate) 1745 { 1746 struct dentry *dentry = filp->f_path.dentry; 1747 struct inode *inode = dentry->d_inode; 1748 struct task_struct *p = get_proc_task(inode); 1749 unsigned int fd, ino; 1750 int retval; 1751 struct files_struct * files; 1752 1753 retval = -ENOENT; 1754 if (!p) 1755 goto out_no_task; 1756 retval = 0; 1757 1758 fd = filp->f_pos; 1759 switch (fd) { 1760 case 0: 1761 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 1762 goto out; 1763 filp->f_pos++; 1764 case 1: 1765 ino = parent_ino(dentry); 1766 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 1767 goto out; 1768 filp->f_pos++; 1769 default: 1770 files = get_files_struct(p); 1771 if (!files) 1772 goto out; 1773 rcu_read_lock(); 1774 for (fd = filp->f_pos-2; 1775 fd < files_fdtable(files)->max_fds; 1776 fd++, filp->f_pos++) { 1777 char name[PROC_NUMBUF]; 1778 int len; 1779 1780 if (!fcheck_files(files, fd)) 1781 continue; 1782 rcu_read_unlock(); 1783 1784 len = snprintf(name, sizeof(name), "%d", fd); 1785 if (proc_fill_cache(filp, dirent, filldir, 1786 name, len, instantiate, 1787 p, &fd) < 0) { 1788 rcu_read_lock(); 1789 break; 1790 } 1791 rcu_read_lock(); 1792 } 1793 rcu_read_unlock(); 1794 put_files_struct(files); 1795 } 1796 out: 1797 put_task_struct(p); 1798 out_no_task: 1799 return retval; 1800 } 1801 1802 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 1803 struct nameidata *nd) 1804 { 1805 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 1806 } 1807 1808 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 1809 { 1810 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 1811 } 1812 1813 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 1814 size_t len, loff_t *ppos) 1815 { 1816 char tmp[PROC_FDINFO_MAX]; 1817 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); 1818 if (!err) 1819 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 1820 return err; 1821 } 1822 1823 static const struct file_operations proc_fdinfo_file_operations = { 1824 .open = nonseekable_open, 1825 .read = proc_fdinfo_read, 1826 }; 1827 1828 static const struct file_operations proc_fd_operations = { 1829 .read = generic_read_dir, 1830 .readdir = proc_readfd, 1831 }; 1832 1833 /* 1834 * /proc/pid/fd needs a special permission handler so that a process can still 1835 * access /proc/self/fd after it has executed a setuid(). 1836 */ 1837 static int proc_fd_permission(struct inode *inode, int mask, 1838 struct nameidata *nd) 1839 { 1840 int rv; 1841 1842 rv = generic_permission(inode, mask, NULL); 1843 if (rv == 0) 1844 return 0; 1845 if (task_pid(current) == proc_pid(inode)) 1846 rv = 0; 1847 return rv; 1848 } 1849 1850 /* 1851 * proc directories can do almost nothing.. 1852 */ 1853 static const struct inode_operations proc_fd_inode_operations = { 1854 .lookup = proc_lookupfd, 1855 .permission = proc_fd_permission, 1856 .setattr = proc_setattr, 1857 }; 1858 1859 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 1860 struct dentry *dentry, struct task_struct *task, const void *ptr) 1861 { 1862 unsigned fd = *(unsigned *)ptr; 1863 struct inode *inode; 1864 struct proc_inode *ei; 1865 struct dentry *error = ERR_PTR(-ENOENT); 1866 1867 inode = proc_pid_make_inode(dir->i_sb, task); 1868 if (!inode) 1869 goto out; 1870 ei = PROC_I(inode); 1871 ei->fd = fd; 1872 inode->i_mode = S_IFREG | S_IRUSR; 1873 inode->i_fop = &proc_fdinfo_file_operations; 1874 dentry->d_op = &tid_fd_dentry_operations; 1875 d_add(dentry, inode); 1876 /* Close the race of the process dying before we return the dentry */ 1877 if (tid_fd_revalidate(dentry, NULL)) 1878 error = NULL; 1879 1880 out: 1881 return error; 1882 } 1883 1884 static struct dentry *proc_lookupfdinfo(struct inode *dir, 1885 struct dentry *dentry, 1886 struct nameidata *nd) 1887 { 1888 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 1889 } 1890 1891 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 1892 { 1893 return proc_readfd_common(filp, dirent, filldir, 1894 proc_fdinfo_instantiate); 1895 } 1896 1897 static const struct file_operations proc_fdinfo_operations = { 1898 .read = generic_read_dir, 1899 .readdir = proc_readfdinfo, 1900 }; 1901 1902 /* 1903 * proc directories can do almost nothing.. 1904 */ 1905 static const struct inode_operations proc_fdinfo_inode_operations = { 1906 .lookup = proc_lookupfdinfo, 1907 .setattr = proc_setattr, 1908 }; 1909 1910 1911 static struct dentry *proc_pident_instantiate(struct inode *dir, 1912 struct dentry *dentry, struct task_struct *task, const void *ptr) 1913 { 1914 const struct pid_entry *p = ptr; 1915 struct inode *inode; 1916 struct proc_inode *ei; 1917 struct dentry *error = ERR_PTR(-EINVAL); 1918 1919 inode = proc_pid_make_inode(dir->i_sb, task); 1920 if (!inode) 1921 goto out; 1922 1923 ei = PROC_I(inode); 1924 inode->i_mode = p->mode; 1925 if (S_ISDIR(inode->i_mode)) 1926 inode->i_nlink = 2; /* Use getattr to fix if necessary */ 1927 if (p->iop) 1928 inode->i_op = p->iop; 1929 if (p->fop) 1930 inode->i_fop = p->fop; 1931 ei->op = p->op; 1932 dentry->d_op = &pid_dentry_operations; 1933 d_add(dentry, inode); 1934 /* Close the race of the process dying before we return the dentry */ 1935 if (pid_revalidate(dentry, NULL)) 1936 error = NULL; 1937 out: 1938 return error; 1939 } 1940 1941 static struct dentry *proc_pident_lookup(struct inode *dir, 1942 struct dentry *dentry, 1943 const struct pid_entry *ents, 1944 unsigned int nents) 1945 { 1946 struct inode *inode; 1947 struct dentry *error; 1948 struct task_struct *task = get_proc_task(dir); 1949 const struct pid_entry *p, *last; 1950 1951 error = ERR_PTR(-ENOENT); 1952 inode = NULL; 1953 1954 if (!task) 1955 goto out_no_task; 1956 1957 /* 1958 * Yes, it does not scale. And it should not. Don't add 1959 * new entries into /proc/<tgid>/ without very good reasons. 1960 */ 1961 last = &ents[nents - 1]; 1962 for (p = ents; p <= last; p++) { 1963 if (p->len != dentry->d_name.len) 1964 continue; 1965 if (!memcmp(dentry->d_name.name, p->name, p->len)) 1966 break; 1967 } 1968 if (p > last) 1969 goto out; 1970 1971 error = proc_pident_instantiate(dir, dentry, task, p); 1972 out: 1973 put_task_struct(task); 1974 out_no_task: 1975 return error; 1976 } 1977 1978 static int proc_pident_fill_cache(struct file *filp, void *dirent, 1979 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 1980 { 1981 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 1982 proc_pident_instantiate, task, p); 1983 } 1984 1985 static int proc_pident_readdir(struct file *filp, 1986 void *dirent, filldir_t filldir, 1987 const struct pid_entry *ents, unsigned int nents) 1988 { 1989 int i; 1990 struct dentry *dentry = filp->f_path.dentry; 1991 struct inode *inode = dentry->d_inode; 1992 struct task_struct *task = get_proc_task(inode); 1993 const struct pid_entry *p, *last; 1994 ino_t ino; 1995 int ret; 1996 1997 ret = -ENOENT; 1998 if (!task) 1999 goto out_no_task; 2000 2001 ret = 0; 2002 i = filp->f_pos; 2003 switch (i) { 2004 case 0: 2005 ino = inode->i_ino; 2006 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 2007 goto out; 2008 i++; 2009 filp->f_pos++; 2010 /* fall through */ 2011 case 1: 2012 ino = parent_ino(dentry); 2013 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 2014 goto out; 2015 i++; 2016 filp->f_pos++; 2017 /* fall through */ 2018 default: 2019 i -= 2; 2020 if (i >= nents) { 2021 ret = 1; 2022 goto out; 2023 } 2024 p = ents + i; 2025 last = &ents[nents - 1]; 2026 while (p <= last) { 2027 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2028 goto out; 2029 filp->f_pos++; 2030 p++; 2031 } 2032 } 2033 2034 ret = 1; 2035 out: 2036 put_task_struct(task); 2037 out_no_task: 2038 return ret; 2039 } 2040 2041 #ifdef CONFIG_SECURITY 2042 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2043 size_t count, loff_t *ppos) 2044 { 2045 struct inode * inode = file->f_path.dentry->d_inode; 2046 char *p = NULL; 2047 ssize_t length; 2048 struct task_struct *task = get_proc_task(inode); 2049 2050 if (!task) 2051 return -ESRCH; 2052 2053 length = security_getprocattr(task, 2054 (char*)file->f_path.dentry->d_name.name, 2055 &p); 2056 put_task_struct(task); 2057 if (length > 0) 2058 length = simple_read_from_buffer(buf, count, ppos, p, length); 2059 kfree(p); 2060 return length; 2061 } 2062 2063 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2064 size_t count, loff_t *ppos) 2065 { 2066 struct inode * inode = file->f_path.dentry->d_inode; 2067 char *page; 2068 ssize_t length; 2069 struct task_struct *task = get_proc_task(inode); 2070 2071 length = -ESRCH; 2072 if (!task) 2073 goto out_no_task; 2074 if (count > PAGE_SIZE) 2075 count = PAGE_SIZE; 2076 2077 /* No partial writes. */ 2078 length = -EINVAL; 2079 if (*ppos != 0) 2080 goto out; 2081 2082 length = -ENOMEM; 2083 page = (char*)__get_free_page(GFP_TEMPORARY); 2084 if (!page) 2085 goto out; 2086 2087 length = -EFAULT; 2088 if (copy_from_user(page, buf, count)) 2089 goto out_free; 2090 2091 length = security_setprocattr(task, 2092 (char*)file->f_path.dentry->d_name.name, 2093 (void*)page, count); 2094 out_free: 2095 free_page((unsigned long) page); 2096 out: 2097 put_task_struct(task); 2098 out_no_task: 2099 return length; 2100 } 2101 2102 static const struct file_operations proc_pid_attr_operations = { 2103 .read = proc_pid_attr_read, 2104 .write = proc_pid_attr_write, 2105 }; 2106 2107 static const struct pid_entry attr_dir_stuff[] = { 2108 REG("current", S_IRUGO|S_IWUGO, pid_attr), 2109 REG("prev", S_IRUGO, pid_attr), 2110 REG("exec", S_IRUGO|S_IWUGO, pid_attr), 2111 REG("fscreate", S_IRUGO|S_IWUGO, pid_attr), 2112 REG("keycreate", S_IRUGO|S_IWUGO, pid_attr), 2113 REG("sockcreate", S_IRUGO|S_IWUGO, pid_attr), 2114 }; 2115 2116 static int proc_attr_dir_readdir(struct file * filp, 2117 void * dirent, filldir_t filldir) 2118 { 2119 return proc_pident_readdir(filp,dirent,filldir, 2120 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2121 } 2122 2123 static const struct file_operations proc_attr_dir_operations = { 2124 .read = generic_read_dir, 2125 .readdir = proc_attr_dir_readdir, 2126 }; 2127 2128 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2129 struct dentry *dentry, struct nameidata *nd) 2130 { 2131 return proc_pident_lookup(dir, dentry, 2132 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2133 } 2134 2135 static const struct inode_operations proc_attr_dir_inode_operations = { 2136 .lookup = proc_attr_dir_lookup, 2137 .getattr = pid_getattr, 2138 .setattr = proc_setattr, 2139 }; 2140 2141 #endif 2142 2143 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2144 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2145 size_t count, loff_t *ppos) 2146 { 2147 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2148 struct mm_struct *mm; 2149 char buffer[PROC_NUMBUF]; 2150 size_t len; 2151 int ret; 2152 2153 if (!task) 2154 return -ESRCH; 2155 2156 ret = 0; 2157 mm = get_task_mm(task); 2158 if (mm) { 2159 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2160 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2161 MMF_DUMP_FILTER_SHIFT)); 2162 mmput(mm); 2163 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2164 } 2165 2166 put_task_struct(task); 2167 2168 return ret; 2169 } 2170 2171 static ssize_t proc_coredump_filter_write(struct file *file, 2172 const char __user *buf, 2173 size_t count, 2174 loff_t *ppos) 2175 { 2176 struct task_struct *task; 2177 struct mm_struct *mm; 2178 char buffer[PROC_NUMBUF], *end; 2179 unsigned int val; 2180 int ret; 2181 int i; 2182 unsigned long mask; 2183 2184 ret = -EFAULT; 2185 memset(buffer, 0, sizeof(buffer)); 2186 if (count > sizeof(buffer) - 1) 2187 count = sizeof(buffer) - 1; 2188 if (copy_from_user(buffer, buf, count)) 2189 goto out_no_task; 2190 2191 ret = -EINVAL; 2192 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2193 if (*end == '\n') 2194 end++; 2195 if (end - buffer == 0) 2196 goto out_no_task; 2197 2198 ret = -ESRCH; 2199 task = get_proc_task(file->f_dentry->d_inode); 2200 if (!task) 2201 goto out_no_task; 2202 2203 ret = end - buffer; 2204 mm = get_task_mm(task); 2205 if (!mm) 2206 goto out_no_mm; 2207 2208 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2209 if (val & mask) 2210 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2211 else 2212 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2213 } 2214 2215 mmput(mm); 2216 out_no_mm: 2217 put_task_struct(task); 2218 out_no_task: 2219 return ret; 2220 } 2221 2222 static const struct file_operations proc_coredump_filter_operations = { 2223 .read = proc_coredump_filter_read, 2224 .write = proc_coredump_filter_write, 2225 }; 2226 #endif 2227 2228 /* 2229 * /proc/self: 2230 */ 2231 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2232 int buflen) 2233 { 2234 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2235 pid_t tgid = task_tgid_nr_ns(current, ns); 2236 char tmp[PROC_NUMBUF]; 2237 if (!tgid) 2238 return -ENOENT; 2239 sprintf(tmp, "%d", tgid); 2240 return vfs_readlink(dentry,buffer,buflen,tmp); 2241 } 2242 2243 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2244 { 2245 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2246 pid_t tgid = task_tgid_nr_ns(current, ns); 2247 char tmp[PROC_NUMBUF]; 2248 if (!tgid) 2249 return ERR_PTR(-ENOENT); 2250 sprintf(tmp, "%d", task_tgid_nr_ns(current, ns)); 2251 return ERR_PTR(vfs_follow_link(nd,tmp)); 2252 } 2253 2254 static const struct inode_operations proc_self_inode_operations = { 2255 .readlink = proc_self_readlink, 2256 .follow_link = proc_self_follow_link, 2257 }; 2258 2259 /* 2260 * proc base 2261 * 2262 * These are the directory entries in the root directory of /proc 2263 * that properly belong to the /proc filesystem, as they describe 2264 * describe something that is process related. 2265 */ 2266 static const struct pid_entry proc_base_stuff[] = { 2267 NOD("self", S_IFLNK|S_IRWXUGO, 2268 &proc_self_inode_operations, NULL, {}), 2269 }; 2270 2271 /* 2272 * Exceptional case: normally we are not allowed to unhash a busy 2273 * directory. In this case, however, we can do it - no aliasing problems 2274 * due to the way we treat inodes. 2275 */ 2276 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) 2277 { 2278 struct inode *inode = dentry->d_inode; 2279 struct task_struct *task = get_proc_task(inode); 2280 if (task) { 2281 put_task_struct(task); 2282 return 1; 2283 } 2284 d_drop(dentry); 2285 return 0; 2286 } 2287 2288 static struct dentry_operations proc_base_dentry_operations = 2289 { 2290 .d_revalidate = proc_base_revalidate, 2291 .d_delete = pid_delete_dentry, 2292 }; 2293 2294 static struct dentry *proc_base_instantiate(struct inode *dir, 2295 struct dentry *dentry, struct task_struct *task, const void *ptr) 2296 { 2297 const struct pid_entry *p = ptr; 2298 struct inode *inode; 2299 struct proc_inode *ei; 2300 struct dentry *error = ERR_PTR(-EINVAL); 2301 2302 /* Allocate the inode */ 2303 error = ERR_PTR(-ENOMEM); 2304 inode = new_inode(dir->i_sb); 2305 if (!inode) 2306 goto out; 2307 2308 /* Initialize the inode */ 2309 ei = PROC_I(inode); 2310 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2311 2312 /* 2313 * grab the reference to the task. 2314 */ 2315 ei->pid = get_task_pid(task, PIDTYPE_PID); 2316 if (!ei->pid) 2317 goto out_iput; 2318 2319 inode->i_uid = 0; 2320 inode->i_gid = 0; 2321 inode->i_mode = p->mode; 2322 if (S_ISDIR(inode->i_mode)) 2323 inode->i_nlink = 2; 2324 if (S_ISLNK(inode->i_mode)) 2325 inode->i_size = 64; 2326 if (p->iop) 2327 inode->i_op = p->iop; 2328 if (p->fop) 2329 inode->i_fop = p->fop; 2330 ei->op = p->op; 2331 dentry->d_op = &proc_base_dentry_operations; 2332 d_add(dentry, inode); 2333 error = NULL; 2334 out: 2335 return error; 2336 out_iput: 2337 iput(inode); 2338 goto out; 2339 } 2340 2341 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2342 { 2343 struct dentry *error; 2344 struct task_struct *task = get_proc_task(dir); 2345 const struct pid_entry *p, *last; 2346 2347 error = ERR_PTR(-ENOENT); 2348 2349 if (!task) 2350 goto out_no_task; 2351 2352 /* Lookup the directory entry */ 2353 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2354 for (p = proc_base_stuff; p <= last; p++) { 2355 if (p->len != dentry->d_name.len) 2356 continue; 2357 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2358 break; 2359 } 2360 if (p > last) 2361 goto out; 2362 2363 error = proc_base_instantiate(dir, dentry, task, p); 2364 2365 out: 2366 put_task_struct(task); 2367 out_no_task: 2368 return error; 2369 } 2370 2371 static int proc_base_fill_cache(struct file *filp, void *dirent, 2372 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2373 { 2374 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2375 proc_base_instantiate, task, p); 2376 } 2377 2378 #ifdef CONFIG_TASK_IO_ACCOUNTING 2379 static int proc_pid_io_accounting(struct task_struct *task, char *buffer) 2380 { 2381 return sprintf(buffer, 2382 #ifdef CONFIG_TASK_XACCT 2383 "rchar: %llu\n" 2384 "wchar: %llu\n" 2385 "syscr: %llu\n" 2386 "syscw: %llu\n" 2387 #endif 2388 "read_bytes: %llu\n" 2389 "write_bytes: %llu\n" 2390 "cancelled_write_bytes: %llu\n", 2391 #ifdef CONFIG_TASK_XACCT 2392 (unsigned long long)task->rchar, 2393 (unsigned long long)task->wchar, 2394 (unsigned long long)task->syscr, 2395 (unsigned long long)task->syscw, 2396 #endif 2397 (unsigned long long)task->ioac.read_bytes, 2398 (unsigned long long)task->ioac.write_bytes, 2399 (unsigned long long)task->ioac.cancelled_write_bytes); 2400 } 2401 #endif 2402 2403 /* 2404 * Thread groups 2405 */ 2406 static const struct file_operations proc_task_operations; 2407 static const struct inode_operations proc_task_inode_operations; 2408 2409 static const struct pid_entry tgid_base_stuff[] = { 2410 DIR("task", S_IRUGO|S_IXUGO, task), 2411 DIR("fd", S_IRUSR|S_IXUSR, fd), 2412 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), 2413 #ifdef CONFIG_NET 2414 DIR("net", S_IRUGO|S_IXUGO, net), 2415 #endif 2416 REG("environ", S_IRUSR, environ), 2417 INF("auxv", S_IRUSR, pid_auxv), 2418 ONE("status", S_IRUGO, pid_status), 2419 INF("limits", S_IRUSR, pid_limits), 2420 #ifdef CONFIG_SCHED_DEBUG 2421 REG("sched", S_IRUGO|S_IWUSR, pid_sched), 2422 #endif 2423 INF("cmdline", S_IRUGO, pid_cmdline), 2424 ONE("stat", S_IRUGO, tgid_stat), 2425 ONE("statm", S_IRUGO, pid_statm), 2426 REG("maps", S_IRUGO, maps), 2427 #ifdef CONFIG_NUMA 2428 REG("numa_maps", S_IRUGO, numa_maps), 2429 #endif 2430 REG("mem", S_IRUSR|S_IWUSR, mem), 2431 LNK("cwd", cwd), 2432 LNK("root", root), 2433 LNK("exe", exe), 2434 REG("mounts", S_IRUGO, mounts), 2435 REG("mountinfo", S_IRUGO, mountinfo), 2436 REG("mountstats", S_IRUSR, mountstats), 2437 #ifdef CONFIG_PROC_PAGE_MONITOR 2438 REG("clear_refs", S_IWUSR, clear_refs), 2439 REG("smaps", S_IRUGO, smaps), 2440 REG("pagemap", S_IRUSR, pagemap), 2441 #endif 2442 #ifdef CONFIG_SECURITY 2443 DIR("attr", S_IRUGO|S_IXUGO, attr_dir), 2444 #endif 2445 #ifdef CONFIG_KALLSYMS 2446 INF("wchan", S_IRUGO, pid_wchan), 2447 #endif 2448 #ifdef CONFIG_SCHEDSTATS 2449 INF("schedstat", S_IRUGO, pid_schedstat), 2450 #endif 2451 #ifdef CONFIG_LATENCYTOP 2452 REG("latency", S_IRUGO, lstats), 2453 #endif 2454 #ifdef CONFIG_PROC_PID_CPUSET 2455 REG("cpuset", S_IRUGO, cpuset), 2456 #endif 2457 #ifdef CONFIG_CGROUPS 2458 REG("cgroup", S_IRUGO, cgroup), 2459 #endif 2460 INF("oom_score", S_IRUGO, oom_score), 2461 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust), 2462 #ifdef CONFIG_AUDITSYSCALL 2463 REG("loginuid", S_IWUSR|S_IRUGO, loginuid), 2464 REG("sessionid", S_IRUGO, sessionid), 2465 #endif 2466 #ifdef CONFIG_FAULT_INJECTION 2467 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject), 2468 #endif 2469 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2470 REG("coredump_filter", S_IRUGO|S_IWUSR, coredump_filter), 2471 #endif 2472 #ifdef CONFIG_TASK_IO_ACCOUNTING 2473 INF("io", S_IRUGO, pid_io_accounting), 2474 #endif 2475 }; 2476 2477 static int proc_tgid_base_readdir(struct file * filp, 2478 void * dirent, filldir_t filldir) 2479 { 2480 return proc_pident_readdir(filp,dirent,filldir, 2481 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2482 } 2483 2484 static const struct file_operations proc_tgid_base_operations = { 2485 .read = generic_read_dir, 2486 .readdir = proc_tgid_base_readdir, 2487 }; 2488 2489 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2490 return proc_pident_lookup(dir, dentry, 2491 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2492 } 2493 2494 static const struct inode_operations proc_tgid_base_inode_operations = { 2495 .lookup = proc_tgid_base_lookup, 2496 .getattr = pid_getattr, 2497 .setattr = proc_setattr, 2498 }; 2499 2500 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2501 { 2502 struct dentry *dentry, *leader, *dir; 2503 char buf[PROC_NUMBUF]; 2504 struct qstr name; 2505 2506 name.name = buf; 2507 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2508 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2509 if (dentry) { 2510 if (!(current->flags & PF_EXITING)) 2511 shrink_dcache_parent(dentry); 2512 d_drop(dentry); 2513 dput(dentry); 2514 } 2515 2516 if (tgid == 0) 2517 goto out; 2518 2519 name.name = buf; 2520 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2521 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2522 if (!leader) 2523 goto out; 2524 2525 name.name = "task"; 2526 name.len = strlen(name.name); 2527 dir = d_hash_and_lookup(leader, &name); 2528 if (!dir) 2529 goto out_put_leader; 2530 2531 name.name = buf; 2532 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2533 dentry = d_hash_and_lookup(dir, &name); 2534 if (dentry) { 2535 shrink_dcache_parent(dentry); 2536 d_drop(dentry); 2537 dput(dentry); 2538 } 2539 2540 dput(dir); 2541 out_put_leader: 2542 dput(leader); 2543 out: 2544 return; 2545 } 2546 2547 /** 2548 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2549 * @task: task that should be flushed. 2550 * 2551 * When flushing dentries from proc, one needs to flush them from global 2552 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2553 * in. This call is supposed to do all of this job. 2554 * 2555 * Looks in the dcache for 2556 * /proc/@pid 2557 * /proc/@tgid/task/@pid 2558 * if either directory is present flushes it and all of it'ts children 2559 * from the dcache. 2560 * 2561 * It is safe and reasonable to cache /proc entries for a task until 2562 * that task exits. After that they just clog up the dcache with 2563 * useless entries, possibly causing useful dcache entries to be 2564 * flushed instead. This routine is proved to flush those useless 2565 * dcache entries at process exit time. 2566 * 2567 * NOTE: This routine is just an optimization so it does not guarantee 2568 * that no dcache entries will exist at process exit time it 2569 * just makes it very unlikely that any will persist. 2570 */ 2571 2572 void proc_flush_task(struct task_struct *task) 2573 { 2574 int i; 2575 struct pid *pid, *tgid = NULL; 2576 struct upid *upid; 2577 2578 pid = task_pid(task); 2579 if (thread_group_leader(task)) 2580 tgid = task_tgid(task); 2581 2582 for (i = 0; i <= pid->level; i++) { 2583 upid = &pid->numbers[i]; 2584 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 2585 tgid ? tgid->numbers[i].nr : 0); 2586 } 2587 2588 upid = &pid->numbers[pid->level]; 2589 if (upid->nr == 1) 2590 pid_ns_release_proc(upid->ns); 2591 } 2592 2593 static struct dentry *proc_pid_instantiate(struct inode *dir, 2594 struct dentry * dentry, 2595 struct task_struct *task, const void *ptr) 2596 { 2597 struct dentry *error = ERR_PTR(-ENOENT); 2598 struct inode *inode; 2599 2600 inode = proc_pid_make_inode(dir->i_sb, task); 2601 if (!inode) 2602 goto out; 2603 2604 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2605 inode->i_op = &proc_tgid_base_inode_operations; 2606 inode->i_fop = &proc_tgid_base_operations; 2607 inode->i_flags|=S_IMMUTABLE; 2608 2609 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff, 2610 ARRAY_SIZE(tgid_base_stuff)); 2611 2612 dentry->d_op = &pid_dentry_operations; 2613 2614 d_add(dentry, inode); 2615 /* Close the race of the process dying before we return the dentry */ 2616 if (pid_revalidate(dentry, NULL)) 2617 error = NULL; 2618 out: 2619 return error; 2620 } 2621 2622 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2623 { 2624 struct dentry *result = ERR_PTR(-ENOENT); 2625 struct task_struct *task; 2626 unsigned tgid; 2627 struct pid_namespace *ns; 2628 2629 result = proc_base_lookup(dir, dentry); 2630 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 2631 goto out; 2632 2633 tgid = name_to_int(dentry); 2634 if (tgid == ~0U) 2635 goto out; 2636 2637 ns = dentry->d_sb->s_fs_info; 2638 rcu_read_lock(); 2639 task = find_task_by_pid_ns(tgid, ns); 2640 if (task) 2641 get_task_struct(task); 2642 rcu_read_unlock(); 2643 if (!task) 2644 goto out; 2645 2646 result = proc_pid_instantiate(dir, dentry, task, NULL); 2647 put_task_struct(task); 2648 out: 2649 return result; 2650 } 2651 2652 /* 2653 * Find the first task with tgid >= tgid 2654 * 2655 */ 2656 struct tgid_iter { 2657 unsigned int tgid; 2658 struct task_struct *task; 2659 }; 2660 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 2661 { 2662 struct pid *pid; 2663 2664 if (iter.task) 2665 put_task_struct(iter.task); 2666 rcu_read_lock(); 2667 retry: 2668 iter.task = NULL; 2669 pid = find_ge_pid(iter.tgid, ns); 2670 if (pid) { 2671 iter.tgid = pid_nr_ns(pid, ns); 2672 iter.task = pid_task(pid, PIDTYPE_PID); 2673 /* What we to know is if the pid we have find is the 2674 * pid of a thread_group_leader. Testing for task 2675 * being a thread_group_leader is the obvious thing 2676 * todo but there is a window when it fails, due to 2677 * the pid transfer logic in de_thread. 2678 * 2679 * So we perform the straight forward test of seeing 2680 * if the pid we have found is the pid of a thread 2681 * group leader, and don't worry if the task we have 2682 * found doesn't happen to be a thread group leader. 2683 * As we don't care in the case of readdir. 2684 */ 2685 if (!iter.task || !has_group_leader_pid(iter.task)) { 2686 iter.tgid += 1; 2687 goto retry; 2688 } 2689 get_task_struct(iter.task); 2690 } 2691 rcu_read_unlock(); 2692 return iter; 2693 } 2694 2695 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 2696 2697 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2698 struct tgid_iter iter) 2699 { 2700 char name[PROC_NUMBUF]; 2701 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 2702 return proc_fill_cache(filp, dirent, filldir, name, len, 2703 proc_pid_instantiate, iter.task, NULL); 2704 } 2705 2706 /* for the /proc/ directory itself, after non-process stuff has been done */ 2707 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 2708 { 2709 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; 2710 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode); 2711 struct tgid_iter iter; 2712 struct pid_namespace *ns; 2713 2714 if (!reaper) 2715 goto out_no_task; 2716 2717 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 2718 const struct pid_entry *p = &proc_base_stuff[nr]; 2719 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 2720 goto out; 2721 } 2722 2723 ns = filp->f_dentry->d_sb->s_fs_info; 2724 iter.task = NULL; 2725 iter.tgid = filp->f_pos - TGID_OFFSET; 2726 for (iter = next_tgid(ns, iter); 2727 iter.task; 2728 iter.tgid += 1, iter = next_tgid(ns, iter)) { 2729 filp->f_pos = iter.tgid + TGID_OFFSET; 2730 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) { 2731 put_task_struct(iter.task); 2732 goto out; 2733 } 2734 } 2735 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 2736 out: 2737 put_task_struct(reaper); 2738 out_no_task: 2739 return 0; 2740 } 2741 2742 /* 2743 * Tasks 2744 */ 2745 static const struct pid_entry tid_base_stuff[] = { 2746 DIR("fd", S_IRUSR|S_IXUSR, fd), 2747 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), 2748 REG("environ", S_IRUSR, environ), 2749 INF("auxv", S_IRUSR, pid_auxv), 2750 ONE("status", S_IRUGO, pid_status), 2751 INF("limits", S_IRUSR, pid_limits), 2752 #ifdef CONFIG_SCHED_DEBUG 2753 REG("sched", S_IRUGO|S_IWUSR, pid_sched), 2754 #endif 2755 INF("cmdline", S_IRUGO, pid_cmdline), 2756 ONE("stat", S_IRUGO, tid_stat), 2757 ONE("statm", S_IRUGO, pid_statm), 2758 REG("maps", S_IRUGO, maps), 2759 #ifdef CONFIG_NUMA 2760 REG("numa_maps", S_IRUGO, numa_maps), 2761 #endif 2762 REG("mem", S_IRUSR|S_IWUSR, mem), 2763 LNK("cwd", cwd), 2764 LNK("root", root), 2765 LNK("exe", exe), 2766 REG("mounts", S_IRUGO, mounts), 2767 REG("mountinfo", S_IRUGO, mountinfo), 2768 #ifdef CONFIG_PROC_PAGE_MONITOR 2769 REG("clear_refs", S_IWUSR, clear_refs), 2770 REG("smaps", S_IRUGO, smaps), 2771 REG("pagemap", S_IRUSR, pagemap), 2772 #endif 2773 #ifdef CONFIG_SECURITY 2774 DIR("attr", S_IRUGO|S_IXUGO, attr_dir), 2775 #endif 2776 #ifdef CONFIG_KALLSYMS 2777 INF("wchan", S_IRUGO, pid_wchan), 2778 #endif 2779 #ifdef CONFIG_SCHEDSTATS 2780 INF("schedstat", S_IRUGO, pid_schedstat), 2781 #endif 2782 #ifdef CONFIG_LATENCYTOP 2783 REG("latency", S_IRUGO, lstats), 2784 #endif 2785 #ifdef CONFIG_PROC_PID_CPUSET 2786 REG("cpuset", S_IRUGO, cpuset), 2787 #endif 2788 #ifdef CONFIG_CGROUPS 2789 REG("cgroup", S_IRUGO, cgroup), 2790 #endif 2791 INF("oom_score", S_IRUGO, oom_score), 2792 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust), 2793 #ifdef CONFIG_AUDITSYSCALL 2794 REG("loginuid", S_IWUSR|S_IRUGO, loginuid), 2795 REG("sessionid", S_IRUSR, sessionid), 2796 #endif 2797 #ifdef CONFIG_FAULT_INJECTION 2798 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject), 2799 #endif 2800 }; 2801 2802 static int proc_tid_base_readdir(struct file * filp, 2803 void * dirent, filldir_t filldir) 2804 { 2805 return proc_pident_readdir(filp,dirent,filldir, 2806 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 2807 } 2808 2809 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2810 return proc_pident_lookup(dir, dentry, 2811 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 2812 } 2813 2814 static const struct file_operations proc_tid_base_operations = { 2815 .read = generic_read_dir, 2816 .readdir = proc_tid_base_readdir, 2817 }; 2818 2819 static const struct inode_operations proc_tid_base_inode_operations = { 2820 .lookup = proc_tid_base_lookup, 2821 .getattr = pid_getattr, 2822 .setattr = proc_setattr, 2823 }; 2824 2825 static struct dentry *proc_task_instantiate(struct inode *dir, 2826 struct dentry *dentry, struct task_struct *task, const void *ptr) 2827 { 2828 struct dentry *error = ERR_PTR(-ENOENT); 2829 struct inode *inode; 2830 inode = proc_pid_make_inode(dir->i_sb, task); 2831 2832 if (!inode) 2833 goto out; 2834 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2835 inode->i_op = &proc_tid_base_inode_operations; 2836 inode->i_fop = &proc_tid_base_operations; 2837 inode->i_flags|=S_IMMUTABLE; 2838 2839 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff, 2840 ARRAY_SIZE(tid_base_stuff)); 2841 2842 dentry->d_op = &pid_dentry_operations; 2843 2844 d_add(dentry, inode); 2845 /* Close the race of the process dying before we return the dentry */ 2846 if (pid_revalidate(dentry, NULL)) 2847 error = NULL; 2848 out: 2849 return error; 2850 } 2851 2852 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2853 { 2854 struct dentry *result = ERR_PTR(-ENOENT); 2855 struct task_struct *task; 2856 struct task_struct *leader = get_proc_task(dir); 2857 unsigned tid; 2858 struct pid_namespace *ns; 2859 2860 if (!leader) 2861 goto out_no_task; 2862 2863 tid = name_to_int(dentry); 2864 if (tid == ~0U) 2865 goto out; 2866 2867 ns = dentry->d_sb->s_fs_info; 2868 rcu_read_lock(); 2869 task = find_task_by_pid_ns(tid, ns); 2870 if (task) 2871 get_task_struct(task); 2872 rcu_read_unlock(); 2873 if (!task) 2874 goto out; 2875 if (!same_thread_group(leader, task)) 2876 goto out_drop_task; 2877 2878 result = proc_task_instantiate(dir, dentry, task, NULL); 2879 out_drop_task: 2880 put_task_struct(task); 2881 out: 2882 put_task_struct(leader); 2883 out_no_task: 2884 return result; 2885 } 2886 2887 /* 2888 * Find the first tid of a thread group to return to user space. 2889 * 2890 * Usually this is just the thread group leader, but if the users 2891 * buffer was too small or there was a seek into the middle of the 2892 * directory we have more work todo. 2893 * 2894 * In the case of a short read we start with find_task_by_pid. 2895 * 2896 * In the case of a seek we start with the leader and walk nr 2897 * threads past it. 2898 */ 2899 static struct task_struct *first_tid(struct task_struct *leader, 2900 int tid, int nr, struct pid_namespace *ns) 2901 { 2902 struct task_struct *pos; 2903 2904 rcu_read_lock(); 2905 /* Attempt to start with the pid of a thread */ 2906 if (tid && (nr > 0)) { 2907 pos = find_task_by_pid_ns(tid, ns); 2908 if (pos && (pos->group_leader == leader)) 2909 goto found; 2910 } 2911 2912 /* If nr exceeds the number of threads there is nothing todo */ 2913 pos = NULL; 2914 if (nr && nr >= get_nr_threads(leader)) 2915 goto out; 2916 2917 /* If we haven't found our starting place yet start 2918 * with the leader and walk nr threads forward. 2919 */ 2920 for (pos = leader; nr > 0; --nr) { 2921 pos = next_thread(pos); 2922 if (pos == leader) { 2923 pos = NULL; 2924 goto out; 2925 } 2926 } 2927 found: 2928 get_task_struct(pos); 2929 out: 2930 rcu_read_unlock(); 2931 return pos; 2932 } 2933 2934 /* 2935 * Find the next thread in the thread list. 2936 * Return NULL if there is an error or no next thread. 2937 * 2938 * The reference to the input task_struct is released. 2939 */ 2940 static struct task_struct *next_tid(struct task_struct *start) 2941 { 2942 struct task_struct *pos = NULL; 2943 rcu_read_lock(); 2944 if (pid_alive(start)) { 2945 pos = next_thread(start); 2946 if (thread_group_leader(pos)) 2947 pos = NULL; 2948 else 2949 get_task_struct(pos); 2950 } 2951 rcu_read_unlock(); 2952 put_task_struct(start); 2953 return pos; 2954 } 2955 2956 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2957 struct task_struct *task, int tid) 2958 { 2959 char name[PROC_NUMBUF]; 2960 int len = snprintf(name, sizeof(name), "%d", tid); 2961 return proc_fill_cache(filp, dirent, filldir, name, len, 2962 proc_task_instantiate, task, NULL); 2963 } 2964 2965 /* for the /proc/TGID/task/ directories */ 2966 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 2967 { 2968 struct dentry *dentry = filp->f_path.dentry; 2969 struct inode *inode = dentry->d_inode; 2970 struct task_struct *leader = NULL; 2971 struct task_struct *task; 2972 int retval = -ENOENT; 2973 ino_t ino; 2974 int tid; 2975 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */ 2976 struct pid_namespace *ns; 2977 2978 task = get_proc_task(inode); 2979 if (!task) 2980 goto out_no_task; 2981 rcu_read_lock(); 2982 if (pid_alive(task)) { 2983 leader = task->group_leader; 2984 get_task_struct(leader); 2985 } 2986 rcu_read_unlock(); 2987 put_task_struct(task); 2988 if (!leader) 2989 goto out_no_task; 2990 retval = 0; 2991 2992 switch (pos) { 2993 case 0: 2994 ino = inode->i_ino; 2995 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0) 2996 goto out; 2997 pos++; 2998 /* fall through */ 2999 case 1: 3000 ino = parent_ino(dentry); 3001 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0) 3002 goto out; 3003 pos++; 3004 /* fall through */ 3005 } 3006 3007 /* f_version caches the tgid value that the last readdir call couldn't 3008 * return. lseek aka telldir automagically resets f_version to 0. 3009 */ 3010 ns = filp->f_dentry->d_sb->s_fs_info; 3011 tid = (int)filp->f_version; 3012 filp->f_version = 0; 3013 for (task = first_tid(leader, tid, pos - 2, ns); 3014 task; 3015 task = next_tid(task), pos++) { 3016 tid = task_pid_nr_ns(task, ns); 3017 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 3018 /* returning this tgid failed, save it as the first 3019 * pid for the next readir call */ 3020 filp->f_version = (u64)tid; 3021 put_task_struct(task); 3022 break; 3023 } 3024 } 3025 out: 3026 filp->f_pos = pos; 3027 put_task_struct(leader); 3028 out_no_task: 3029 return retval; 3030 } 3031 3032 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3033 { 3034 struct inode *inode = dentry->d_inode; 3035 struct task_struct *p = get_proc_task(inode); 3036 generic_fillattr(inode, stat); 3037 3038 if (p) { 3039 rcu_read_lock(); 3040 stat->nlink += get_nr_threads(p); 3041 rcu_read_unlock(); 3042 put_task_struct(p); 3043 } 3044 3045 return 0; 3046 } 3047 3048 static const struct inode_operations proc_task_inode_operations = { 3049 .lookup = proc_task_lookup, 3050 .getattr = proc_task_getattr, 3051 .setattr = proc_setattr, 3052 }; 3053 3054 static const struct file_operations proc_task_operations = { 3055 .read = generic_read_dir, 3056 .readdir = proc_task_readdir, 3057 }; 3058