1 /* 2 * linux/fs/proc/base.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 * 6 * proc base directory handling functions 7 * 8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part. 9 * Instead of using magical inumbers to determine the kind of object 10 * we allocate and fill in-core inodes upon lookup. They don't even 11 * go into icache. We cache the reference to task_struct upon lookup too. 12 * Eventually it should become a filesystem in its own. We don't use the 13 * rest of procfs anymore. 14 * 15 * 16 * Changelog: 17 * 17-Jan-2005 18 * Allan Bezerra 19 * Bruna Moreira <bruna.moreira@indt.org.br> 20 * Edjard Mota <edjard.mota@indt.org.br> 21 * Ilias Biris <ilias.biris@indt.org.br> 22 * Mauricio Lin <mauricio.lin@indt.org.br> 23 * 24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 25 * 26 * A new process specific entry (smaps) included in /proc. It shows the 27 * size of rss for each memory area. The maps entry lacks information 28 * about physical memory size (rss) for each mapped file, i.e., 29 * rss information for executables and library files. 30 * This additional information is useful for any tools that need to know 31 * about physical memory consumption for a process specific library. 32 * 33 * Changelog: 34 * 21-Feb-2005 35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 36 * Pud inclusion in the page table walking. 37 * 38 * ChangeLog: 39 * 10-Mar-2005 40 * 10LE Instituto Nokia de Tecnologia - INdT: 41 * A better way to walks through the page table as suggested by Hugh Dickins. 42 * 43 * Simo Piiroinen <simo.piiroinen@nokia.com>: 44 * Smaps information related to shared, private, clean and dirty pages. 45 * 46 * Paul Mundt <paul.mundt@nokia.com>: 47 * Overall revision about smaps. 48 */ 49 50 #include <asm/uaccess.h> 51 52 #include <linux/errno.h> 53 #include <linux/time.h> 54 #include <linux/proc_fs.h> 55 #include <linux/stat.h> 56 #include <linux/task_io_accounting_ops.h> 57 #include <linux/init.h> 58 #include <linux/capability.h> 59 #include <linux/file.h> 60 #include <linux/fdtable.h> 61 #include <linux/string.h> 62 #include <linux/seq_file.h> 63 #include <linux/namei.h> 64 #include <linux/mnt_namespace.h> 65 #include <linux/mm.h> 66 #include <linux/rcupdate.h> 67 #include <linux/kallsyms.h> 68 #include <linux/resource.h> 69 #include <linux/module.h> 70 #include <linux/mount.h> 71 #include <linux/security.h> 72 #include <linux/ptrace.h> 73 #include <linux/tracehook.h> 74 #include <linux/cgroup.h> 75 #include <linux/cpuset.h> 76 #include <linux/audit.h> 77 #include <linux/poll.h> 78 #include <linux/nsproxy.h> 79 #include <linux/oom.h> 80 #include <linux/elf.h> 81 #include <linux/pid_namespace.h> 82 #include "internal.h" 83 84 /* NOTE: 85 * Implementing inode permission operations in /proc is almost 86 * certainly an error. Permission checks need to happen during 87 * each system call not at open time. The reason is that most of 88 * what we wish to check for permissions in /proc varies at runtime. 89 * 90 * The classic example of a problem is opening file descriptors 91 * in /proc for a task before it execs a suid executable. 92 */ 93 94 struct pid_entry { 95 char *name; 96 int len; 97 mode_t mode; 98 const struct inode_operations *iop; 99 const struct file_operations *fop; 100 union proc_op op; 101 }; 102 103 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 104 .name = (NAME), \ 105 .len = sizeof(NAME) - 1, \ 106 .mode = MODE, \ 107 .iop = IOP, \ 108 .fop = FOP, \ 109 .op = OP, \ 110 } 111 112 #define DIR(NAME, MODE, OTYPE) \ 113 NOD(NAME, (S_IFDIR|(MODE)), \ 114 &proc_##OTYPE##_inode_operations, &proc_##OTYPE##_operations, \ 115 {} ) 116 #define LNK(NAME, OTYPE) \ 117 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 118 &proc_pid_link_inode_operations, NULL, \ 119 { .proc_get_link = &proc_##OTYPE##_link } ) 120 #define REG(NAME, MODE, OTYPE) \ 121 NOD(NAME, (S_IFREG|(MODE)), NULL, \ 122 &proc_##OTYPE##_operations, {}) 123 #define INF(NAME, MODE, OTYPE) \ 124 NOD(NAME, (S_IFREG|(MODE)), \ 125 NULL, &proc_info_file_operations, \ 126 { .proc_read = &proc_##OTYPE } ) 127 #define ONE(NAME, MODE, OTYPE) \ 128 NOD(NAME, (S_IFREG|(MODE)), \ 129 NULL, &proc_single_file_operations, \ 130 { .proc_show = &proc_##OTYPE } ) 131 132 /* 133 * Count the number of hardlinks for the pid_entry table, excluding the . 134 * and .. links. 135 */ 136 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries, 137 unsigned int n) 138 { 139 unsigned int i; 140 unsigned int count; 141 142 count = 0; 143 for (i = 0; i < n; ++i) { 144 if (S_ISDIR(entries[i].mode)) 145 ++count; 146 } 147 148 return count; 149 } 150 151 static struct fs_struct *get_fs_struct(struct task_struct *task) 152 { 153 struct fs_struct *fs; 154 task_lock(task); 155 fs = task->fs; 156 if(fs) 157 atomic_inc(&fs->count); 158 task_unlock(task); 159 return fs; 160 } 161 162 static int get_nr_threads(struct task_struct *tsk) 163 { 164 unsigned long flags; 165 int count = 0; 166 167 if (lock_task_sighand(tsk, &flags)) { 168 count = atomic_read(&tsk->signal->count); 169 unlock_task_sighand(tsk, &flags); 170 } 171 return count; 172 } 173 174 static int proc_cwd_link(struct inode *inode, struct path *path) 175 { 176 struct task_struct *task = get_proc_task(inode); 177 struct fs_struct *fs = NULL; 178 int result = -ENOENT; 179 180 if (task) { 181 fs = get_fs_struct(task); 182 put_task_struct(task); 183 } 184 if (fs) { 185 read_lock(&fs->lock); 186 *path = fs->pwd; 187 path_get(&fs->pwd); 188 read_unlock(&fs->lock); 189 result = 0; 190 put_fs_struct(fs); 191 } 192 return result; 193 } 194 195 static int proc_root_link(struct inode *inode, struct path *path) 196 { 197 struct task_struct *task = get_proc_task(inode); 198 struct fs_struct *fs = NULL; 199 int result = -ENOENT; 200 201 if (task) { 202 fs = get_fs_struct(task); 203 put_task_struct(task); 204 } 205 if (fs) { 206 read_lock(&fs->lock); 207 *path = fs->root; 208 path_get(&fs->root); 209 read_unlock(&fs->lock); 210 result = 0; 211 put_fs_struct(fs); 212 } 213 return result; 214 } 215 216 /* 217 * Return zero if current may access user memory in @task, -error if not. 218 */ 219 static int check_mem_permission(struct task_struct *task) 220 { 221 /* 222 * A task can always look at itself, in case it chooses 223 * to use system calls instead of load instructions. 224 */ 225 if (task == current) 226 return 0; 227 228 /* 229 * If current is actively ptrace'ing, and would also be 230 * permitted to freshly attach with ptrace now, permit it. 231 */ 232 if (task_is_stopped_or_traced(task)) { 233 int match; 234 rcu_read_lock(); 235 match = (tracehook_tracer_task(task) == current); 236 rcu_read_unlock(); 237 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH)) 238 return 0; 239 } 240 241 /* 242 * Noone else is allowed. 243 */ 244 return -EPERM; 245 } 246 247 struct mm_struct *mm_for_maps(struct task_struct *task) 248 { 249 struct mm_struct *mm = get_task_mm(task); 250 if (!mm) 251 return NULL; 252 down_read(&mm->mmap_sem); 253 task_lock(task); 254 if (task->mm != mm) 255 goto out; 256 if (task->mm != current->mm && 257 __ptrace_may_access(task, PTRACE_MODE_READ) < 0) 258 goto out; 259 task_unlock(task); 260 return mm; 261 out: 262 task_unlock(task); 263 up_read(&mm->mmap_sem); 264 mmput(mm); 265 return NULL; 266 } 267 268 static int proc_pid_cmdline(struct task_struct *task, char * buffer) 269 { 270 int res = 0; 271 unsigned int len; 272 struct mm_struct *mm = get_task_mm(task); 273 if (!mm) 274 goto out; 275 if (!mm->arg_end) 276 goto out_mm; /* Shh! No looking before we're done */ 277 278 len = mm->arg_end - mm->arg_start; 279 280 if (len > PAGE_SIZE) 281 len = PAGE_SIZE; 282 283 res = access_process_vm(task, mm->arg_start, buffer, len, 0); 284 285 // If the nul at the end of args has been overwritten, then 286 // assume application is using setproctitle(3). 287 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) { 288 len = strnlen(buffer, res); 289 if (len < res) { 290 res = len; 291 } else { 292 len = mm->env_end - mm->env_start; 293 if (len > PAGE_SIZE - res) 294 len = PAGE_SIZE - res; 295 res += access_process_vm(task, mm->env_start, buffer+res, len, 0); 296 res = strnlen(buffer, res); 297 } 298 } 299 out_mm: 300 mmput(mm); 301 out: 302 return res; 303 } 304 305 static int proc_pid_auxv(struct task_struct *task, char *buffer) 306 { 307 int res = 0; 308 struct mm_struct *mm = get_task_mm(task); 309 if (mm) { 310 unsigned int nwords = 0; 311 do 312 nwords += 2; 313 while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 314 res = nwords * sizeof(mm->saved_auxv[0]); 315 if (res > PAGE_SIZE) 316 res = PAGE_SIZE; 317 memcpy(buffer, mm->saved_auxv, res); 318 mmput(mm); 319 } 320 return res; 321 } 322 323 324 #ifdef CONFIG_KALLSYMS 325 /* 326 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 327 * Returns the resolved symbol. If that fails, simply return the address. 328 */ 329 static int proc_pid_wchan(struct task_struct *task, char *buffer) 330 { 331 unsigned long wchan; 332 char symname[KSYM_NAME_LEN]; 333 334 wchan = get_wchan(task); 335 336 if (lookup_symbol_name(wchan, symname) < 0) 337 return sprintf(buffer, "%lu", wchan); 338 else 339 return sprintf(buffer, "%s", symname); 340 } 341 #endif /* CONFIG_KALLSYMS */ 342 343 #ifdef CONFIG_SCHEDSTATS 344 /* 345 * Provides /proc/PID/schedstat 346 */ 347 static int proc_pid_schedstat(struct task_struct *task, char *buffer) 348 { 349 return sprintf(buffer, "%llu %llu %lu\n", 350 (unsigned long long)task->se.sum_exec_runtime, 351 (unsigned long long)task->sched_info.run_delay, 352 task->sched_info.pcount); 353 } 354 #endif 355 356 #ifdef CONFIG_LATENCYTOP 357 static int lstats_show_proc(struct seq_file *m, void *v) 358 { 359 int i; 360 struct inode *inode = m->private; 361 struct task_struct *task = get_proc_task(inode); 362 363 if (!task) 364 return -ESRCH; 365 seq_puts(m, "Latency Top version : v0.1\n"); 366 for (i = 0; i < 32; i++) { 367 if (task->latency_record[i].backtrace[0]) { 368 int q; 369 seq_printf(m, "%i %li %li ", 370 task->latency_record[i].count, 371 task->latency_record[i].time, 372 task->latency_record[i].max); 373 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 374 char sym[KSYM_SYMBOL_LEN]; 375 char *c; 376 if (!task->latency_record[i].backtrace[q]) 377 break; 378 if (task->latency_record[i].backtrace[q] == ULONG_MAX) 379 break; 380 sprint_symbol(sym, task->latency_record[i].backtrace[q]); 381 c = strchr(sym, '+'); 382 if (c) 383 *c = 0; 384 seq_printf(m, "%s ", sym); 385 } 386 seq_printf(m, "\n"); 387 } 388 389 } 390 put_task_struct(task); 391 return 0; 392 } 393 394 static int lstats_open(struct inode *inode, struct file *file) 395 { 396 return single_open(file, lstats_show_proc, inode); 397 } 398 399 static ssize_t lstats_write(struct file *file, const char __user *buf, 400 size_t count, loff_t *offs) 401 { 402 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 403 404 if (!task) 405 return -ESRCH; 406 clear_all_latency_tracing(task); 407 put_task_struct(task); 408 409 return count; 410 } 411 412 static const struct file_operations proc_lstats_operations = { 413 .open = lstats_open, 414 .read = seq_read, 415 .write = lstats_write, 416 .llseek = seq_lseek, 417 .release = single_release, 418 }; 419 420 #endif 421 422 /* The badness from the OOM killer */ 423 unsigned long badness(struct task_struct *p, unsigned long uptime); 424 static int proc_oom_score(struct task_struct *task, char *buffer) 425 { 426 unsigned long points; 427 struct timespec uptime; 428 429 do_posix_clock_monotonic_gettime(&uptime); 430 read_lock(&tasklist_lock); 431 points = badness(task, uptime.tv_sec); 432 read_unlock(&tasklist_lock); 433 return sprintf(buffer, "%lu\n", points); 434 } 435 436 struct limit_names { 437 char *name; 438 char *unit; 439 }; 440 441 static const struct limit_names lnames[RLIM_NLIMITS] = { 442 [RLIMIT_CPU] = {"Max cpu time", "ms"}, 443 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 444 [RLIMIT_DATA] = {"Max data size", "bytes"}, 445 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 446 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 447 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 448 [RLIMIT_NPROC] = {"Max processes", "processes"}, 449 [RLIMIT_NOFILE] = {"Max open files", "files"}, 450 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 451 [RLIMIT_AS] = {"Max address space", "bytes"}, 452 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 453 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 454 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 455 [RLIMIT_NICE] = {"Max nice priority", NULL}, 456 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 457 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 458 }; 459 460 /* Display limits for a process */ 461 static int proc_pid_limits(struct task_struct *task, char *buffer) 462 { 463 unsigned int i; 464 int count = 0; 465 unsigned long flags; 466 char *bufptr = buffer; 467 468 struct rlimit rlim[RLIM_NLIMITS]; 469 470 if (!lock_task_sighand(task, &flags)) 471 return 0; 472 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 473 unlock_task_sighand(task, &flags); 474 475 /* 476 * print the file header 477 */ 478 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n", 479 "Limit", "Soft Limit", "Hard Limit", "Units"); 480 481 for (i = 0; i < RLIM_NLIMITS; i++) { 482 if (rlim[i].rlim_cur == RLIM_INFINITY) 483 count += sprintf(&bufptr[count], "%-25s %-20s ", 484 lnames[i].name, "unlimited"); 485 else 486 count += sprintf(&bufptr[count], "%-25s %-20lu ", 487 lnames[i].name, rlim[i].rlim_cur); 488 489 if (rlim[i].rlim_max == RLIM_INFINITY) 490 count += sprintf(&bufptr[count], "%-20s ", "unlimited"); 491 else 492 count += sprintf(&bufptr[count], "%-20lu ", 493 rlim[i].rlim_max); 494 495 if (lnames[i].unit) 496 count += sprintf(&bufptr[count], "%-10s\n", 497 lnames[i].unit); 498 else 499 count += sprintf(&bufptr[count], "\n"); 500 } 501 502 return count; 503 } 504 505 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 506 static int proc_pid_syscall(struct task_struct *task, char *buffer) 507 { 508 long nr; 509 unsigned long args[6], sp, pc; 510 511 if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) 512 return sprintf(buffer, "running\n"); 513 514 if (nr < 0) 515 return sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc); 516 517 return sprintf(buffer, 518 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", 519 nr, 520 args[0], args[1], args[2], args[3], args[4], args[5], 521 sp, pc); 522 } 523 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 524 525 /************************************************************************/ 526 /* Here the fs part begins */ 527 /************************************************************************/ 528 529 /* permission checks */ 530 static int proc_fd_access_allowed(struct inode *inode) 531 { 532 struct task_struct *task; 533 int allowed = 0; 534 /* Allow access to a task's file descriptors if it is us or we 535 * may use ptrace attach to the process and find out that 536 * information. 537 */ 538 task = get_proc_task(inode); 539 if (task) { 540 allowed = ptrace_may_access(task, PTRACE_MODE_READ); 541 put_task_struct(task); 542 } 543 return allowed; 544 } 545 546 static int proc_setattr(struct dentry *dentry, struct iattr *attr) 547 { 548 int error; 549 struct inode *inode = dentry->d_inode; 550 551 if (attr->ia_valid & ATTR_MODE) 552 return -EPERM; 553 554 error = inode_change_ok(inode, attr); 555 if (!error) 556 error = inode_setattr(inode, attr); 557 return error; 558 } 559 560 static const struct inode_operations proc_def_inode_operations = { 561 .setattr = proc_setattr, 562 }; 563 564 static int mounts_open_common(struct inode *inode, struct file *file, 565 const struct seq_operations *op) 566 { 567 struct task_struct *task = get_proc_task(inode); 568 struct nsproxy *nsp; 569 struct mnt_namespace *ns = NULL; 570 struct fs_struct *fs = NULL; 571 struct path root; 572 struct proc_mounts *p; 573 int ret = -EINVAL; 574 575 if (task) { 576 rcu_read_lock(); 577 nsp = task_nsproxy(task); 578 if (nsp) { 579 ns = nsp->mnt_ns; 580 if (ns) 581 get_mnt_ns(ns); 582 } 583 rcu_read_unlock(); 584 if (ns) 585 fs = get_fs_struct(task); 586 put_task_struct(task); 587 } 588 589 if (!ns) 590 goto err; 591 if (!fs) 592 goto err_put_ns; 593 594 read_lock(&fs->lock); 595 root = fs->root; 596 path_get(&root); 597 read_unlock(&fs->lock); 598 put_fs_struct(fs); 599 600 ret = -ENOMEM; 601 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL); 602 if (!p) 603 goto err_put_path; 604 605 file->private_data = &p->m; 606 ret = seq_open(file, op); 607 if (ret) 608 goto err_free; 609 610 p->m.private = p; 611 p->ns = ns; 612 p->root = root; 613 p->event = ns->event; 614 615 return 0; 616 617 err_free: 618 kfree(p); 619 err_put_path: 620 path_put(&root); 621 err_put_ns: 622 put_mnt_ns(ns); 623 err: 624 return ret; 625 } 626 627 static int mounts_release(struct inode *inode, struct file *file) 628 { 629 struct proc_mounts *p = file->private_data; 630 path_put(&p->root); 631 put_mnt_ns(p->ns); 632 return seq_release(inode, file); 633 } 634 635 static unsigned mounts_poll(struct file *file, poll_table *wait) 636 { 637 struct proc_mounts *p = file->private_data; 638 struct mnt_namespace *ns = p->ns; 639 unsigned res = 0; 640 641 poll_wait(file, &ns->poll, wait); 642 643 spin_lock(&vfsmount_lock); 644 if (p->event != ns->event) { 645 p->event = ns->event; 646 res = POLLERR; 647 } 648 spin_unlock(&vfsmount_lock); 649 650 return res; 651 } 652 653 static int mounts_open(struct inode *inode, struct file *file) 654 { 655 return mounts_open_common(inode, file, &mounts_op); 656 } 657 658 static const struct file_operations proc_mounts_operations = { 659 .open = mounts_open, 660 .read = seq_read, 661 .llseek = seq_lseek, 662 .release = mounts_release, 663 .poll = mounts_poll, 664 }; 665 666 static int mountinfo_open(struct inode *inode, struct file *file) 667 { 668 return mounts_open_common(inode, file, &mountinfo_op); 669 } 670 671 static const struct file_operations proc_mountinfo_operations = { 672 .open = mountinfo_open, 673 .read = seq_read, 674 .llseek = seq_lseek, 675 .release = mounts_release, 676 .poll = mounts_poll, 677 }; 678 679 static int mountstats_open(struct inode *inode, struct file *file) 680 { 681 return mounts_open_common(inode, file, &mountstats_op); 682 } 683 684 static const struct file_operations proc_mountstats_operations = { 685 .open = mountstats_open, 686 .read = seq_read, 687 .llseek = seq_lseek, 688 .release = mounts_release, 689 }; 690 691 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */ 692 693 static ssize_t proc_info_read(struct file * file, char __user * buf, 694 size_t count, loff_t *ppos) 695 { 696 struct inode * inode = file->f_path.dentry->d_inode; 697 unsigned long page; 698 ssize_t length; 699 struct task_struct *task = get_proc_task(inode); 700 701 length = -ESRCH; 702 if (!task) 703 goto out_no_task; 704 705 if (count > PROC_BLOCK_SIZE) 706 count = PROC_BLOCK_SIZE; 707 708 length = -ENOMEM; 709 if (!(page = __get_free_page(GFP_TEMPORARY))) 710 goto out; 711 712 length = PROC_I(inode)->op.proc_read(task, (char*)page); 713 714 if (length >= 0) 715 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length); 716 free_page(page); 717 out: 718 put_task_struct(task); 719 out_no_task: 720 return length; 721 } 722 723 static const struct file_operations proc_info_file_operations = { 724 .read = proc_info_read, 725 }; 726 727 static int proc_single_show(struct seq_file *m, void *v) 728 { 729 struct inode *inode = m->private; 730 struct pid_namespace *ns; 731 struct pid *pid; 732 struct task_struct *task; 733 int ret; 734 735 ns = inode->i_sb->s_fs_info; 736 pid = proc_pid(inode); 737 task = get_pid_task(pid, PIDTYPE_PID); 738 if (!task) 739 return -ESRCH; 740 741 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 742 743 put_task_struct(task); 744 return ret; 745 } 746 747 static int proc_single_open(struct inode *inode, struct file *filp) 748 { 749 int ret; 750 ret = single_open(filp, proc_single_show, NULL); 751 if (!ret) { 752 struct seq_file *m = filp->private_data; 753 754 m->private = inode; 755 } 756 return ret; 757 } 758 759 static const struct file_operations proc_single_file_operations = { 760 .open = proc_single_open, 761 .read = seq_read, 762 .llseek = seq_lseek, 763 .release = single_release, 764 }; 765 766 static int mem_open(struct inode* inode, struct file* file) 767 { 768 file->private_data = (void*)((long)current->self_exec_id); 769 return 0; 770 } 771 772 static ssize_t mem_read(struct file * file, char __user * buf, 773 size_t count, loff_t *ppos) 774 { 775 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 776 char *page; 777 unsigned long src = *ppos; 778 int ret = -ESRCH; 779 struct mm_struct *mm; 780 781 if (!task) 782 goto out_no_task; 783 784 if (check_mem_permission(task)) 785 goto out; 786 787 ret = -ENOMEM; 788 page = (char *)__get_free_page(GFP_TEMPORARY); 789 if (!page) 790 goto out; 791 792 ret = 0; 793 794 mm = get_task_mm(task); 795 if (!mm) 796 goto out_free; 797 798 ret = -EIO; 799 800 if (file->private_data != (void*)((long)current->self_exec_id)) 801 goto out_put; 802 803 ret = 0; 804 805 while (count > 0) { 806 int this_len, retval; 807 808 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 809 retval = access_process_vm(task, src, page, this_len, 0); 810 if (!retval || check_mem_permission(task)) { 811 if (!ret) 812 ret = -EIO; 813 break; 814 } 815 816 if (copy_to_user(buf, page, retval)) { 817 ret = -EFAULT; 818 break; 819 } 820 821 ret += retval; 822 src += retval; 823 buf += retval; 824 count -= retval; 825 } 826 *ppos = src; 827 828 out_put: 829 mmput(mm); 830 out_free: 831 free_page((unsigned long) page); 832 out: 833 put_task_struct(task); 834 out_no_task: 835 return ret; 836 } 837 838 #define mem_write NULL 839 840 #ifndef mem_write 841 /* This is a security hazard */ 842 static ssize_t mem_write(struct file * file, const char __user *buf, 843 size_t count, loff_t *ppos) 844 { 845 int copied; 846 char *page; 847 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 848 unsigned long dst = *ppos; 849 850 copied = -ESRCH; 851 if (!task) 852 goto out_no_task; 853 854 if (check_mem_permission(task)) 855 goto out; 856 857 copied = -ENOMEM; 858 page = (char *)__get_free_page(GFP_TEMPORARY); 859 if (!page) 860 goto out; 861 862 copied = 0; 863 while (count > 0) { 864 int this_len, retval; 865 866 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 867 if (copy_from_user(page, buf, this_len)) { 868 copied = -EFAULT; 869 break; 870 } 871 retval = access_process_vm(task, dst, page, this_len, 1); 872 if (!retval) { 873 if (!copied) 874 copied = -EIO; 875 break; 876 } 877 copied += retval; 878 buf += retval; 879 dst += retval; 880 count -= retval; 881 } 882 *ppos = dst; 883 free_page((unsigned long) page); 884 out: 885 put_task_struct(task); 886 out_no_task: 887 return copied; 888 } 889 #endif 890 891 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 892 { 893 switch (orig) { 894 case 0: 895 file->f_pos = offset; 896 break; 897 case 1: 898 file->f_pos += offset; 899 break; 900 default: 901 return -EINVAL; 902 } 903 force_successful_syscall_return(); 904 return file->f_pos; 905 } 906 907 static const struct file_operations proc_mem_operations = { 908 .llseek = mem_lseek, 909 .read = mem_read, 910 .write = mem_write, 911 .open = mem_open, 912 }; 913 914 static ssize_t environ_read(struct file *file, char __user *buf, 915 size_t count, loff_t *ppos) 916 { 917 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 918 char *page; 919 unsigned long src = *ppos; 920 int ret = -ESRCH; 921 struct mm_struct *mm; 922 923 if (!task) 924 goto out_no_task; 925 926 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 927 goto out; 928 929 ret = -ENOMEM; 930 page = (char *)__get_free_page(GFP_TEMPORARY); 931 if (!page) 932 goto out; 933 934 ret = 0; 935 936 mm = get_task_mm(task); 937 if (!mm) 938 goto out_free; 939 940 while (count > 0) { 941 int this_len, retval, max_len; 942 943 this_len = mm->env_end - (mm->env_start + src); 944 945 if (this_len <= 0) 946 break; 947 948 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 949 this_len = (this_len > max_len) ? max_len : this_len; 950 951 retval = access_process_vm(task, (mm->env_start + src), 952 page, this_len, 0); 953 954 if (retval <= 0) { 955 ret = retval; 956 break; 957 } 958 959 if (copy_to_user(buf, page, retval)) { 960 ret = -EFAULT; 961 break; 962 } 963 964 ret += retval; 965 src += retval; 966 buf += retval; 967 count -= retval; 968 } 969 *ppos = src; 970 971 mmput(mm); 972 out_free: 973 free_page((unsigned long) page); 974 out: 975 put_task_struct(task); 976 out_no_task: 977 return ret; 978 } 979 980 static const struct file_operations proc_environ_operations = { 981 .read = environ_read, 982 }; 983 984 static ssize_t oom_adjust_read(struct file *file, char __user *buf, 985 size_t count, loff_t *ppos) 986 { 987 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 988 char buffer[PROC_NUMBUF]; 989 size_t len; 990 int oom_adjust; 991 992 if (!task) 993 return -ESRCH; 994 oom_adjust = task->oomkilladj; 995 put_task_struct(task); 996 997 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); 998 999 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1000 } 1001 1002 static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 1003 size_t count, loff_t *ppos) 1004 { 1005 struct task_struct *task; 1006 char buffer[PROC_NUMBUF], *end; 1007 int oom_adjust; 1008 1009 memset(buffer, 0, sizeof(buffer)); 1010 if (count > sizeof(buffer) - 1) 1011 count = sizeof(buffer) - 1; 1012 if (copy_from_user(buffer, buf, count)) 1013 return -EFAULT; 1014 oom_adjust = simple_strtol(buffer, &end, 0); 1015 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && 1016 oom_adjust != OOM_DISABLE) 1017 return -EINVAL; 1018 if (*end == '\n') 1019 end++; 1020 task = get_proc_task(file->f_path.dentry->d_inode); 1021 if (!task) 1022 return -ESRCH; 1023 if (oom_adjust < task->oomkilladj && !capable(CAP_SYS_RESOURCE)) { 1024 put_task_struct(task); 1025 return -EACCES; 1026 } 1027 task->oomkilladj = oom_adjust; 1028 put_task_struct(task); 1029 if (end - buffer == 0) 1030 return -EIO; 1031 return end - buffer; 1032 } 1033 1034 static const struct file_operations proc_oom_adjust_operations = { 1035 .read = oom_adjust_read, 1036 .write = oom_adjust_write, 1037 }; 1038 1039 #ifdef CONFIG_AUDITSYSCALL 1040 #define TMPBUFLEN 21 1041 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1042 size_t count, loff_t *ppos) 1043 { 1044 struct inode * inode = file->f_path.dentry->d_inode; 1045 struct task_struct *task = get_proc_task(inode); 1046 ssize_t length; 1047 char tmpbuf[TMPBUFLEN]; 1048 1049 if (!task) 1050 return -ESRCH; 1051 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1052 audit_get_loginuid(task)); 1053 put_task_struct(task); 1054 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1055 } 1056 1057 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1058 size_t count, loff_t *ppos) 1059 { 1060 struct inode * inode = file->f_path.dentry->d_inode; 1061 char *page, *tmp; 1062 ssize_t length; 1063 uid_t loginuid; 1064 1065 if (!capable(CAP_AUDIT_CONTROL)) 1066 return -EPERM; 1067 1068 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) 1069 return -EPERM; 1070 1071 if (count >= PAGE_SIZE) 1072 count = PAGE_SIZE - 1; 1073 1074 if (*ppos != 0) { 1075 /* No partial writes. */ 1076 return -EINVAL; 1077 } 1078 page = (char*)__get_free_page(GFP_TEMPORARY); 1079 if (!page) 1080 return -ENOMEM; 1081 length = -EFAULT; 1082 if (copy_from_user(page, buf, count)) 1083 goto out_free_page; 1084 1085 page[count] = '\0'; 1086 loginuid = simple_strtoul(page, &tmp, 10); 1087 if (tmp == page) { 1088 length = -EINVAL; 1089 goto out_free_page; 1090 1091 } 1092 length = audit_set_loginuid(current, loginuid); 1093 if (likely(length == 0)) 1094 length = count; 1095 1096 out_free_page: 1097 free_page((unsigned long) page); 1098 return length; 1099 } 1100 1101 static const struct file_operations proc_loginuid_operations = { 1102 .read = proc_loginuid_read, 1103 .write = proc_loginuid_write, 1104 }; 1105 1106 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1107 size_t count, loff_t *ppos) 1108 { 1109 struct inode * inode = file->f_path.dentry->d_inode; 1110 struct task_struct *task = get_proc_task(inode); 1111 ssize_t length; 1112 char tmpbuf[TMPBUFLEN]; 1113 1114 if (!task) 1115 return -ESRCH; 1116 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1117 audit_get_sessionid(task)); 1118 put_task_struct(task); 1119 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1120 } 1121 1122 static const struct file_operations proc_sessionid_operations = { 1123 .read = proc_sessionid_read, 1124 }; 1125 #endif 1126 1127 #ifdef CONFIG_FAULT_INJECTION 1128 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1129 size_t count, loff_t *ppos) 1130 { 1131 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1132 char buffer[PROC_NUMBUF]; 1133 size_t len; 1134 int make_it_fail; 1135 1136 if (!task) 1137 return -ESRCH; 1138 make_it_fail = task->make_it_fail; 1139 put_task_struct(task); 1140 1141 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1142 1143 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1144 } 1145 1146 static ssize_t proc_fault_inject_write(struct file * file, 1147 const char __user * buf, size_t count, loff_t *ppos) 1148 { 1149 struct task_struct *task; 1150 char buffer[PROC_NUMBUF], *end; 1151 int make_it_fail; 1152 1153 if (!capable(CAP_SYS_RESOURCE)) 1154 return -EPERM; 1155 memset(buffer, 0, sizeof(buffer)); 1156 if (count > sizeof(buffer) - 1) 1157 count = sizeof(buffer) - 1; 1158 if (copy_from_user(buffer, buf, count)) 1159 return -EFAULT; 1160 make_it_fail = simple_strtol(buffer, &end, 0); 1161 if (*end == '\n') 1162 end++; 1163 task = get_proc_task(file->f_dentry->d_inode); 1164 if (!task) 1165 return -ESRCH; 1166 task->make_it_fail = make_it_fail; 1167 put_task_struct(task); 1168 if (end - buffer == 0) 1169 return -EIO; 1170 return end - buffer; 1171 } 1172 1173 static const struct file_operations proc_fault_inject_operations = { 1174 .read = proc_fault_inject_read, 1175 .write = proc_fault_inject_write, 1176 }; 1177 #endif 1178 1179 1180 #ifdef CONFIG_SCHED_DEBUG 1181 /* 1182 * Print out various scheduling related per-task fields: 1183 */ 1184 static int sched_show(struct seq_file *m, void *v) 1185 { 1186 struct inode *inode = m->private; 1187 struct task_struct *p; 1188 1189 WARN_ON(!inode); 1190 1191 p = get_proc_task(inode); 1192 if (!p) 1193 return -ESRCH; 1194 proc_sched_show_task(p, m); 1195 1196 put_task_struct(p); 1197 1198 return 0; 1199 } 1200 1201 static ssize_t 1202 sched_write(struct file *file, const char __user *buf, 1203 size_t count, loff_t *offset) 1204 { 1205 struct inode *inode = file->f_path.dentry->d_inode; 1206 struct task_struct *p; 1207 1208 WARN_ON(!inode); 1209 1210 p = get_proc_task(inode); 1211 if (!p) 1212 return -ESRCH; 1213 proc_sched_set_task(p); 1214 1215 put_task_struct(p); 1216 1217 return count; 1218 } 1219 1220 static int sched_open(struct inode *inode, struct file *filp) 1221 { 1222 int ret; 1223 1224 ret = single_open(filp, sched_show, NULL); 1225 if (!ret) { 1226 struct seq_file *m = filp->private_data; 1227 1228 m->private = inode; 1229 } 1230 return ret; 1231 } 1232 1233 static const struct file_operations proc_pid_sched_operations = { 1234 .open = sched_open, 1235 .read = seq_read, 1236 .write = sched_write, 1237 .llseek = seq_lseek, 1238 .release = single_release, 1239 }; 1240 1241 #endif 1242 1243 /* 1244 * We added or removed a vma mapping the executable. The vmas are only mapped 1245 * during exec and are not mapped with the mmap system call. 1246 * Callers must hold down_write() on the mm's mmap_sem for these 1247 */ 1248 void added_exe_file_vma(struct mm_struct *mm) 1249 { 1250 mm->num_exe_file_vmas++; 1251 } 1252 1253 void removed_exe_file_vma(struct mm_struct *mm) 1254 { 1255 mm->num_exe_file_vmas--; 1256 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){ 1257 fput(mm->exe_file); 1258 mm->exe_file = NULL; 1259 } 1260 1261 } 1262 1263 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) 1264 { 1265 if (new_exe_file) 1266 get_file(new_exe_file); 1267 if (mm->exe_file) 1268 fput(mm->exe_file); 1269 mm->exe_file = new_exe_file; 1270 mm->num_exe_file_vmas = 0; 1271 } 1272 1273 struct file *get_mm_exe_file(struct mm_struct *mm) 1274 { 1275 struct file *exe_file; 1276 1277 /* We need mmap_sem to protect against races with removal of 1278 * VM_EXECUTABLE vmas */ 1279 down_read(&mm->mmap_sem); 1280 exe_file = mm->exe_file; 1281 if (exe_file) 1282 get_file(exe_file); 1283 up_read(&mm->mmap_sem); 1284 return exe_file; 1285 } 1286 1287 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm) 1288 { 1289 /* It's safe to write the exe_file pointer without exe_file_lock because 1290 * this is called during fork when the task is not yet in /proc */ 1291 newmm->exe_file = get_mm_exe_file(oldmm); 1292 } 1293 1294 static int proc_exe_link(struct inode *inode, struct path *exe_path) 1295 { 1296 struct task_struct *task; 1297 struct mm_struct *mm; 1298 struct file *exe_file; 1299 1300 task = get_proc_task(inode); 1301 if (!task) 1302 return -ENOENT; 1303 mm = get_task_mm(task); 1304 put_task_struct(task); 1305 if (!mm) 1306 return -ENOENT; 1307 exe_file = get_mm_exe_file(mm); 1308 mmput(mm); 1309 if (exe_file) { 1310 *exe_path = exe_file->f_path; 1311 path_get(&exe_file->f_path); 1312 fput(exe_file); 1313 return 0; 1314 } else 1315 return -ENOENT; 1316 } 1317 1318 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1319 { 1320 struct inode *inode = dentry->d_inode; 1321 int error = -EACCES; 1322 1323 /* We don't need a base pointer in the /proc filesystem */ 1324 path_put(&nd->path); 1325 1326 /* Are we allowed to snoop on the tasks file descriptors? */ 1327 if (!proc_fd_access_allowed(inode)) 1328 goto out; 1329 1330 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path); 1331 nd->last_type = LAST_BIND; 1332 out: 1333 return ERR_PTR(error); 1334 } 1335 1336 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1337 { 1338 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1339 char *pathname; 1340 int len; 1341 1342 if (!tmp) 1343 return -ENOMEM; 1344 1345 pathname = d_path(path, tmp, PAGE_SIZE); 1346 len = PTR_ERR(pathname); 1347 if (IS_ERR(pathname)) 1348 goto out; 1349 len = tmp + PAGE_SIZE - 1 - pathname; 1350 1351 if (len > buflen) 1352 len = buflen; 1353 if (copy_to_user(buffer, pathname, len)) 1354 len = -EFAULT; 1355 out: 1356 free_page((unsigned long)tmp); 1357 return len; 1358 } 1359 1360 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1361 { 1362 int error = -EACCES; 1363 struct inode *inode = dentry->d_inode; 1364 struct path path; 1365 1366 /* Are we allowed to snoop on the tasks file descriptors? */ 1367 if (!proc_fd_access_allowed(inode)) 1368 goto out; 1369 1370 error = PROC_I(inode)->op.proc_get_link(inode, &path); 1371 if (error) 1372 goto out; 1373 1374 error = do_proc_readlink(&path, buffer, buflen); 1375 path_put(&path); 1376 out: 1377 return error; 1378 } 1379 1380 static const struct inode_operations proc_pid_link_inode_operations = { 1381 .readlink = proc_pid_readlink, 1382 .follow_link = proc_pid_follow_link, 1383 .setattr = proc_setattr, 1384 }; 1385 1386 1387 /* building an inode */ 1388 1389 static int task_dumpable(struct task_struct *task) 1390 { 1391 int dumpable = 0; 1392 struct mm_struct *mm; 1393 1394 task_lock(task); 1395 mm = task->mm; 1396 if (mm) 1397 dumpable = get_dumpable(mm); 1398 task_unlock(task); 1399 if(dumpable == 1) 1400 return 1; 1401 return 0; 1402 } 1403 1404 1405 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1406 { 1407 struct inode * inode; 1408 struct proc_inode *ei; 1409 const struct cred *cred; 1410 1411 /* We need a new inode */ 1412 1413 inode = new_inode(sb); 1414 if (!inode) 1415 goto out; 1416 1417 /* Common stuff */ 1418 ei = PROC_I(inode); 1419 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1420 inode->i_op = &proc_def_inode_operations; 1421 1422 /* 1423 * grab the reference to task. 1424 */ 1425 ei->pid = get_task_pid(task, PIDTYPE_PID); 1426 if (!ei->pid) 1427 goto out_unlock; 1428 1429 if (task_dumpable(task)) { 1430 rcu_read_lock(); 1431 cred = __task_cred(task); 1432 inode->i_uid = cred->euid; 1433 inode->i_gid = cred->egid; 1434 rcu_read_unlock(); 1435 } 1436 security_task_to_inode(task, inode); 1437 1438 out: 1439 return inode; 1440 1441 out_unlock: 1442 iput(inode); 1443 return NULL; 1444 } 1445 1446 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1447 { 1448 struct inode *inode = dentry->d_inode; 1449 struct task_struct *task; 1450 const struct cred *cred; 1451 1452 generic_fillattr(inode, stat); 1453 1454 rcu_read_lock(); 1455 stat->uid = 0; 1456 stat->gid = 0; 1457 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1458 if (task) { 1459 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1460 task_dumpable(task)) { 1461 cred = __task_cred(task); 1462 stat->uid = cred->euid; 1463 stat->gid = cred->egid; 1464 } 1465 } 1466 rcu_read_unlock(); 1467 return 0; 1468 } 1469 1470 /* dentry stuff */ 1471 1472 /* 1473 * Exceptional case: normally we are not allowed to unhash a busy 1474 * directory. In this case, however, we can do it - no aliasing problems 1475 * due to the way we treat inodes. 1476 * 1477 * Rewrite the inode's ownerships here because the owning task may have 1478 * performed a setuid(), etc. 1479 * 1480 * Before the /proc/pid/status file was created the only way to read 1481 * the effective uid of a /process was to stat /proc/pid. Reading 1482 * /proc/pid/status is slow enough that procps and other packages 1483 * kept stating /proc/pid. To keep the rules in /proc simple I have 1484 * made this apply to all per process world readable and executable 1485 * directories. 1486 */ 1487 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1488 { 1489 struct inode *inode = dentry->d_inode; 1490 struct task_struct *task = get_proc_task(inode); 1491 const struct cred *cred; 1492 1493 if (task) { 1494 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1495 task_dumpable(task)) { 1496 rcu_read_lock(); 1497 cred = __task_cred(task); 1498 inode->i_uid = cred->euid; 1499 inode->i_gid = cred->egid; 1500 rcu_read_unlock(); 1501 } else { 1502 inode->i_uid = 0; 1503 inode->i_gid = 0; 1504 } 1505 inode->i_mode &= ~(S_ISUID | S_ISGID); 1506 security_task_to_inode(task, inode); 1507 put_task_struct(task); 1508 return 1; 1509 } 1510 d_drop(dentry); 1511 return 0; 1512 } 1513 1514 static int pid_delete_dentry(struct dentry * dentry) 1515 { 1516 /* Is the task we represent dead? 1517 * If so, then don't put the dentry on the lru list, 1518 * kill it immediately. 1519 */ 1520 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1521 } 1522 1523 static struct dentry_operations pid_dentry_operations = 1524 { 1525 .d_revalidate = pid_revalidate, 1526 .d_delete = pid_delete_dentry, 1527 }; 1528 1529 /* Lookups */ 1530 1531 typedef struct dentry *instantiate_t(struct inode *, struct dentry *, 1532 struct task_struct *, const void *); 1533 1534 /* 1535 * Fill a directory entry. 1536 * 1537 * If possible create the dcache entry and derive our inode number and 1538 * file type from dcache entry. 1539 * 1540 * Since all of the proc inode numbers are dynamically generated, the inode 1541 * numbers do not exist until the inode is cache. This means creating the 1542 * the dcache entry in readdir is necessary to keep the inode numbers 1543 * reported by readdir in sync with the inode numbers reported 1544 * by stat. 1545 */ 1546 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1547 char *name, int len, 1548 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1549 { 1550 struct dentry *child, *dir = filp->f_path.dentry; 1551 struct inode *inode; 1552 struct qstr qname; 1553 ino_t ino = 0; 1554 unsigned type = DT_UNKNOWN; 1555 1556 qname.name = name; 1557 qname.len = len; 1558 qname.hash = full_name_hash(name, len); 1559 1560 child = d_lookup(dir, &qname); 1561 if (!child) { 1562 struct dentry *new; 1563 new = d_alloc(dir, &qname); 1564 if (new) { 1565 child = instantiate(dir->d_inode, new, task, ptr); 1566 if (child) 1567 dput(new); 1568 else 1569 child = new; 1570 } 1571 } 1572 if (!child || IS_ERR(child) || !child->d_inode) 1573 goto end_instantiate; 1574 inode = child->d_inode; 1575 if (inode) { 1576 ino = inode->i_ino; 1577 type = inode->i_mode >> 12; 1578 } 1579 dput(child); 1580 end_instantiate: 1581 if (!ino) 1582 ino = find_inode_number(dir, &qname); 1583 if (!ino) 1584 ino = 1; 1585 return filldir(dirent, name, len, filp->f_pos, ino, type); 1586 } 1587 1588 static unsigned name_to_int(struct dentry *dentry) 1589 { 1590 const char *name = dentry->d_name.name; 1591 int len = dentry->d_name.len; 1592 unsigned n = 0; 1593 1594 if (len > 1 && *name == '0') 1595 goto out; 1596 while (len-- > 0) { 1597 unsigned c = *name++ - '0'; 1598 if (c > 9) 1599 goto out; 1600 if (n >= (~0U-9)/10) 1601 goto out; 1602 n *= 10; 1603 n += c; 1604 } 1605 return n; 1606 out: 1607 return ~0U; 1608 } 1609 1610 #define PROC_FDINFO_MAX 64 1611 1612 static int proc_fd_info(struct inode *inode, struct path *path, char *info) 1613 { 1614 struct task_struct *task = get_proc_task(inode); 1615 struct files_struct *files = NULL; 1616 struct file *file; 1617 int fd = proc_fd(inode); 1618 1619 if (task) { 1620 files = get_files_struct(task); 1621 put_task_struct(task); 1622 } 1623 if (files) { 1624 /* 1625 * We are not taking a ref to the file structure, so we must 1626 * hold ->file_lock. 1627 */ 1628 spin_lock(&files->file_lock); 1629 file = fcheck_files(files, fd); 1630 if (file) { 1631 if (path) { 1632 *path = file->f_path; 1633 path_get(&file->f_path); 1634 } 1635 if (info) 1636 snprintf(info, PROC_FDINFO_MAX, 1637 "pos:\t%lli\n" 1638 "flags:\t0%o\n", 1639 (long long) file->f_pos, 1640 file->f_flags); 1641 spin_unlock(&files->file_lock); 1642 put_files_struct(files); 1643 return 0; 1644 } 1645 spin_unlock(&files->file_lock); 1646 put_files_struct(files); 1647 } 1648 return -ENOENT; 1649 } 1650 1651 static int proc_fd_link(struct inode *inode, struct path *path) 1652 { 1653 return proc_fd_info(inode, path, NULL); 1654 } 1655 1656 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1657 { 1658 struct inode *inode = dentry->d_inode; 1659 struct task_struct *task = get_proc_task(inode); 1660 int fd = proc_fd(inode); 1661 struct files_struct *files; 1662 const struct cred *cred; 1663 1664 if (task) { 1665 files = get_files_struct(task); 1666 if (files) { 1667 rcu_read_lock(); 1668 if (fcheck_files(files, fd)) { 1669 rcu_read_unlock(); 1670 put_files_struct(files); 1671 if (task_dumpable(task)) { 1672 rcu_read_lock(); 1673 cred = __task_cred(task); 1674 inode->i_uid = cred->euid; 1675 inode->i_gid = cred->egid; 1676 rcu_read_unlock(); 1677 } else { 1678 inode->i_uid = 0; 1679 inode->i_gid = 0; 1680 } 1681 inode->i_mode &= ~(S_ISUID | S_ISGID); 1682 security_task_to_inode(task, inode); 1683 put_task_struct(task); 1684 return 1; 1685 } 1686 rcu_read_unlock(); 1687 put_files_struct(files); 1688 } 1689 put_task_struct(task); 1690 } 1691 d_drop(dentry); 1692 return 0; 1693 } 1694 1695 static struct dentry_operations tid_fd_dentry_operations = 1696 { 1697 .d_revalidate = tid_fd_revalidate, 1698 .d_delete = pid_delete_dentry, 1699 }; 1700 1701 static struct dentry *proc_fd_instantiate(struct inode *dir, 1702 struct dentry *dentry, struct task_struct *task, const void *ptr) 1703 { 1704 unsigned fd = *(const unsigned *)ptr; 1705 struct file *file; 1706 struct files_struct *files; 1707 struct inode *inode; 1708 struct proc_inode *ei; 1709 struct dentry *error = ERR_PTR(-ENOENT); 1710 1711 inode = proc_pid_make_inode(dir->i_sb, task); 1712 if (!inode) 1713 goto out; 1714 ei = PROC_I(inode); 1715 ei->fd = fd; 1716 files = get_files_struct(task); 1717 if (!files) 1718 goto out_iput; 1719 inode->i_mode = S_IFLNK; 1720 1721 /* 1722 * We are not taking a ref to the file structure, so we must 1723 * hold ->file_lock. 1724 */ 1725 spin_lock(&files->file_lock); 1726 file = fcheck_files(files, fd); 1727 if (!file) 1728 goto out_unlock; 1729 if (file->f_mode & FMODE_READ) 1730 inode->i_mode |= S_IRUSR | S_IXUSR; 1731 if (file->f_mode & FMODE_WRITE) 1732 inode->i_mode |= S_IWUSR | S_IXUSR; 1733 spin_unlock(&files->file_lock); 1734 put_files_struct(files); 1735 1736 inode->i_op = &proc_pid_link_inode_operations; 1737 inode->i_size = 64; 1738 ei->op.proc_get_link = proc_fd_link; 1739 dentry->d_op = &tid_fd_dentry_operations; 1740 d_add(dentry, inode); 1741 /* Close the race of the process dying before we return the dentry */ 1742 if (tid_fd_revalidate(dentry, NULL)) 1743 error = NULL; 1744 1745 out: 1746 return error; 1747 out_unlock: 1748 spin_unlock(&files->file_lock); 1749 put_files_struct(files); 1750 out_iput: 1751 iput(inode); 1752 goto out; 1753 } 1754 1755 static struct dentry *proc_lookupfd_common(struct inode *dir, 1756 struct dentry *dentry, 1757 instantiate_t instantiate) 1758 { 1759 struct task_struct *task = get_proc_task(dir); 1760 unsigned fd = name_to_int(dentry); 1761 struct dentry *result = ERR_PTR(-ENOENT); 1762 1763 if (!task) 1764 goto out_no_task; 1765 if (fd == ~0U) 1766 goto out; 1767 1768 result = instantiate(dir, dentry, task, &fd); 1769 out: 1770 put_task_struct(task); 1771 out_no_task: 1772 return result; 1773 } 1774 1775 static int proc_readfd_common(struct file * filp, void * dirent, 1776 filldir_t filldir, instantiate_t instantiate) 1777 { 1778 struct dentry *dentry = filp->f_path.dentry; 1779 struct inode *inode = dentry->d_inode; 1780 struct task_struct *p = get_proc_task(inode); 1781 unsigned int fd, ino; 1782 int retval; 1783 struct files_struct * files; 1784 1785 retval = -ENOENT; 1786 if (!p) 1787 goto out_no_task; 1788 retval = 0; 1789 1790 fd = filp->f_pos; 1791 switch (fd) { 1792 case 0: 1793 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 1794 goto out; 1795 filp->f_pos++; 1796 case 1: 1797 ino = parent_ino(dentry); 1798 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 1799 goto out; 1800 filp->f_pos++; 1801 default: 1802 files = get_files_struct(p); 1803 if (!files) 1804 goto out; 1805 rcu_read_lock(); 1806 for (fd = filp->f_pos-2; 1807 fd < files_fdtable(files)->max_fds; 1808 fd++, filp->f_pos++) { 1809 char name[PROC_NUMBUF]; 1810 int len; 1811 1812 if (!fcheck_files(files, fd)) 1813 continue; 1814 rcu_read_unlock(); 1815 1816 len = snprintf(name, sizeof(name), "%d", fd); 1817 if (proc_fill_cache(filp, dirent, filldir, 1818 name, len, instantiate, 1819 p, &fd) < 0) { 1820 rcu_read_lock(); 1821 break; 1822 } 1823 rcu_read_lock(); 1824 } 1825 rcu_read_unlock(); 1826 put_files_struct(files); 1827 } 1828 out: 1829 put_task_struct(p); 1830 out_no_task: 1831 return retval; 1832 } 1833 1834 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 1835 struct nameidata *nd) 1836 { 1837 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 1838 } 1839 1840 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 1841 { 1842 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 1843 } 1844 1845 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 1846 size_t len, loff_t *ppos) 1847 { 1848 char tmp[PROC_FDINFO_MAX]; 1849 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); 1850 if (!err) 1851 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 1852 return err; 1853 } 1854 1855 static const struct file_operations proc_fdinfo_file_operations = { 1856 .open = nonseekable_open, 1857 .read = proc_fdinfo_read, 1858 }; 1859 1860 static const struct file_operations proc_fd_operations = { 1861 .read = generic_read_dir, 1862 .readdir = proc_readfd, 1863 }; 1864 1865 /* 1866 * /proc/pid/fd needs a special permission handler so that a process can still 1867 * access /proc/self/fd after it has executed a setuid(). 1868 */ 1869 static int proc_fd_permission(struct inode *inode, int mask) 1870 { 1871 int rv; 1872 1873 rv = generic_permission(inode, mask, NULL); 1874 if (rv == 0) 1875 return 0; 1876 if (task_pid(current) == proc_pid(inode)) 1877 rv = 0; 1878 return rv; 1879 } 1880 1881 /* 1882 * proc directories can do almost nothing.. 1883 */ 1884 static const struct inode_operations proc_fd_inode_operations = { 1885 .lookup = proc_lookupfd, 1886 .permission = proc_fd_permission, 1887 .setattr = proc_setattr, 1888 }; 1889 1890 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 1891 struct dentry *dentry, struct task_struct *task, const void *ptr) 1892 { 1893 unsigned fd = *(unsigned *)ptr; 1894 struct inode *inode; 1895 struct proc_inode *ei; 1896 struct dentry *error = ERR_PTR(-ENOENT); 1897 1898 inode = proc_pid_make_inode(dir->i_sb, task); 1899 if (!inode) 1900 goto out; 1901 ei = PROC_I(inode); 1902 ei->fd = fd; 1903 inode->i_mode = S_IFREG | S_IRUSR; 1904 inode->i_fop = &proc_fdinfo_file_operations; 1905 dentry->d_op = &tid_fd_dentry_operations; 1906 d_add(dentry, inode); 1907 /* Close the race of the process dying before we return the dentry */ 1908 if (tid_fd_revalidate(dentry, NULL)) 1909 error = NULL; 1910 1911 out: 1912 return error; 1913 } 1914 1915 static struct dentry *proc_lookupfdinfo(struct inode *dir, 1916 struct dentry *dentry, 1917 struct nameidata *nd) 1918 { 1919 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 1920 } 1921 1922 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 1923 { 1924 return proc_readfd_common(filp, dirent, filldir, 1925 proc_fdinfo_instantiate); 1926 } 1927 1928 static const struct file_operations proc_fdinfo_operations = { 1929 .read = generic_read_dir, 1930 .readdir = proc_readfdinfo, 1931 }; 1932 1933 /* 1934 * proc directories can do almost nothing.. 1935 */ 1936 static const struct inode_operations proc_fdinfo_inode_operations = { 1937 .lookup = proc_lookupfdinfo, 1938 .setattr = proc_setattr, 1939 }; 1940 1941 1942 static struct dentry *proc_pident_instantiate(struct inode *dir, 1943 struct dentry *dentry, struct task_struct *task, const void *ptr) 1944 { 1945 const struct pid_entry *p = ptr; 1946 struct inode *inode; 1947 struct proc_inode *ei; 1948 struct dentry *error = ERR_PTR(-EINVAL); 1949 1950 inode = proc_pid_make_inode(dir->i_sb, task); 1951 if (!inode) 1952 goto out; 1953 1954 ei = PROC_I(inode); 1955 inode->i_mode = p->mode; 1956 if (S_ISDIR(inode->i_mode)) 1957 inode->i_nlink = 2; /* Use getattr to fix if necessary */ 1958 if (p->iop) 1959 inode->i_op = p->iop; 1960 if (p->fop) 1961 inode->i_fop = p->fop; 1962 ei->op = p->op; 1963 dentry->d_op = &pid_dentry_operations; 1964 d_add(dentry, inode); 1965 /* Close the race of the process dying before we return the dentry */ 1966 if (pid_revalidate(dentry, NULL)) 1967 error = NULL; 1968 out: 1969 return error; 1970 } 1971 1972 static struct dentry *proc_pident_lookup(struct inode *dir, 1973 struct dentry *dentry, 1974 const struct pid_entry *ents, 1975 unsigned int nents) 1976 { 1977 struct inode *inode; 1978 struct dentry *error; 1979 struct task_struct *task = get_proc_task(dir); 1980 const struct pid_entry *p, *last; 1981 1982 error = ERR_PTR(-ENOENT); 1983 inode = NULL; 1984 1985 if (!task) 1986 goto out_no_task; 1987 1988 /* 1989 * Yes, it does not scale. And it should not. Don't add 1990 * new entries into /proc/<tgid>/ without very good reasons. 1991 */ 1992 last = &ents[nents - 1]; 1993 for (p = ents; p <= last; p++) { 1994 if (p->len != dentry->d_name.len) 1995 continue; 1996 if (!memcmp(dentry->d_name.name, p->name, p->len)) 1997 break; 1998 } 1999 if (p > last) 2000 goto out; 2001 2002 error = proc_pident_instantiate(dir, dentry, task, p); 2003 out: 2004 put_task_struct(task); 2005 out_no_task: 2006 return error; 2007 } 2008 2009 static int proc_pident_fill_cache(struct file *filp, void *dirent, 2010 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2011 { 2012 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2013 proc_pident_instantiate, task, p); 2014 } 2015 2016 static int proc_pident_readdir(struct file *filp, 2017 void *dirent, filldir_t filldir, 2018 const struct pid_entry *ents, unsigned int nents) 2019 { 2020 int i; 2021 struct dentry *dentry = filp->f_path.dentry; 2022 struct inode *inode = dentry->d_inode; 2023 struct task_struct *task = get_proc_task(inode); 2024 const struct pid_entry *p, *last; 2025 ino_t ino; 2026 int ret; 2027 2028 ret = -ENOENT; 2029 if (!task) 2030 goto out_no_task; 2031 2032 ret = 0; 2033 i = filp->f_pos; 2034 switch (i) { 2035 case 0: 2036 ino = inode->i_ino; 2037 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 2038 goto out; 2039 i++; 2040 filp->f_pos++; 2041 /* fall through */ 2042 case 1: 2043 ino = parent_ino(dentry); 2044 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 2045 goto out; 2046 i++; 2047 filp->f_pos++; 2048 /* fall through */ 2049 default: 2050 i -= 2; 2051 if (i >= nents) { 2052 ret = 1; 2053 goto out; 2054 } 2055 p = ents + i; 2056 last = &ents[nents - 1]; 2057 while (p <= last) { 2058 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2059 goto out; 2060 filp->f_pos++; 2061 p++; 2062 } 2063 } 2064 2065 ret = 1; 2066 out: 2067 put_task_struct(task); 2068 out_no_task: 2069 return ret; 2070 } 2071 2072 #ifdef CONFIG_SECURITY 2073 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2074 size_t count, loff_t *ppos) 2075 { 2076 struct inode * inode = file->f_path.dentry->d_inode; 2077 char *p = NULL; 2078 ssize_t length; 2079 struct task_struct *task = get_proc_task(inode); 2080 2081 if (!task) 2082 return -ESRCH; 2083 2084 length = security_getprocattr(task, 2085 (char*)file->f_path.dentry->d_name.name, 2086 &p); 2087 put_task_struct(task); 2088 if (length > 0) 2089 length = simple_read_from_buffer(buf, count, ppos, p, length); 2090 kfree(p); 2091 return length; 2092 } 2093 2094 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2095 size_t count, loff_t *ppos) 2096 { 2097 struct inode * inode = file->f_path.dentry->d_inode; 2098 char *page; 2099 ssize_t length; 2100 struct task_struct *task = get_proc_task(inode); 2101 2102 length = -ESRCH; 2103 if (!task) 2104 goto out_no_task; 2105 if (count > PAGE_SIZE) 2106 count = PAGE_SIZE; 2107 2108 /* No partial writes. */ 2109 length = -EINVAL; 2110 if (*ppos != 0) 2111 goto out; 2112 2113 length = -ENOMEM; 2114 page = (char*)__get_free_page(GFP_TEMPORARY); 2115 if (!page) 2116 goto out; 2117 2118 length = -EFAULT; 2119 if (copy_from_user(page, buf, count)) 2120 goto out_free; 2121 2122 length = security_setprocattr(task, 2123 (char*)file->f_path.dentry->d_name.name, 2124 (void*)page, count); 2125 out_free: 2126 free_page((unsigned long) page); 2127 out: 2128 put_task_struct(task); 2129 out_no_task: 2130 return length; 2131 } 2132 2133 static const struct file_operations proc_pid_attr_operations = { 2134 .read = proc_pid_attr_read, 2135 .write = proc_pid_attr_write, 2136 }; 2137 2138 static const struct pid_entry attr_dir_stuff[] = { 2139 REG("current", S_IRUGO|S_IWUGO, pid_attr), 2140 REG("prev", S_IRUGO, pid_attr), 2141 REG("exec", S_IRUGO|S_IWUGO, pid_attr), 2142 REG("fscreate", S_IRUGO|S_IWUGO, pid_attr), 2143 REG("keycreate", S_IRUGO|S_IWUGO, pid_attr), 2144 REG("sockcreate", S_IRUGO|S_IWUGO, pid_attr), 2145 }; 2146 2147 static int proc_attr_dir_readdir(struct file * filp, 2148 void * dirent, filldir_t filldir) 2149 { 2150 return proc_pident_readdir(filp,dirent,filldir, 2151 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2152 } 2153 2154 static const struct file_operations proc_attr_dir_operations = { 2155 .read = generic_read_dir, 2156 .readdir = proc_attr_dir_readdir, 2157 }; 2158 2159 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2160 struct dentry *dentry, struct nameidata *nd) 2161 { 2162 return proc_pident_lookup(dir, dentry, 2163 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2164 } 2165 2166 static const struct inode_operations proc_attr_dir_inode_operations = { 2167 .lookup = proc_attr_dir_lookup, 2168 .getattr = pid_getattr, 2169 .setattr = proc_setattr, 2170 }; 2171 2172 #endif 2173 2174 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2175 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2176 size_t count, loff_t *ppos) 2177 { 2178 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2179 struct mm_struct *mm; 2180 char buffer[PROC_NUMBUF]; 2181 size_t len; 2182 int ret; 2183 2184 if (!task) 2185 return -ESRCH; 2186 2187 ret = 0; 2188 mm = get_task_mm(task); 2189 if (mm) { 2190 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2191 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2192 MMF_DUMP_FILTER_SHIFT)); 2193 mmput(mm); 2194 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2195 } 2196 2197 put_task_struct(task); 2198 2199 return ret; 2200 } 2201 2202 static ssize_t proc_coredump_filter_write(struct file *file, 2203 const char __user *buf, 2204 size_t count, 2205 loff_t *ppos) 2206 { 2207 struct task_struct *task; 2208 struct mm_struct *mm; 2209 char buffer[PROC_NUMBUF], *end; 2210 unsigned int val; 2211 int ret; 2212 int i; 2213 unsigned long mask; 2214 2215 ret = -EFAULT; 2216 memset(buffer, 0, sizeof(buffer)); 2217 if (count > sizeof(buffer) - 1) 2218 count = sizeof(buffer) - 1; 2219 if (copy_from_user(buffer, buf, count)) 2220 goto out_no_task; 2221 2222 ret = -EINVAL; 2223 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2224 if (*end == '\n') 2225 end++; 2226 if (end - buffer == 0) 2227 goto out_no_task; 2228 2229 ret = -ESRCH; 2230 task = get_proc_task(file->f_dentry->d_inode); 2231 if (!task) 2232 goto out_no_task; 2233 2234 ret = end - buffer; 2235 mm = get_task_mm(task); 2236 if (!mm) 2237 goto out_no_mm; 2238 2239 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2240 if (val & mask) 2241 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2242 else 2243 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2244 } 2245 2246 mmput(mm); 2247 out_no_mm: 2248 put_task_struct(task); 2249 out_no_task: 2250 return ret; 2251 } 2252 2253 static const struct file_operations proc_coredump_filter_operations = { 2254 .read = proc_coredump_filter_read, 2255 .write = proc_coredump_filter_write, 2256 }; 2257 #endif 2258 2259 /* 2260 * /proc/self: 2261 */ 2262 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2263 int buflen) 2264 { 2265 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2266 pid_t tgid = task_tgid_nr_ns(current, ns); 2267 char tmp[PROC_NUMBUF]; 2268 if (!tgid) 2269 return -ENOENT; 2270 sprintf(tmp, "%d", tgid); 2271 return vfs_readlink(dentry,buffer,buflen,tmp); 2272 } 2273 2274 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2275 { 2276 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2277 pid_t tgid = task_tgid_nr_ns(current, ns); 2278 char tmp[PROC_NUMBUF]; 2279 if (!tgid) 2280 return ERR_PTR(-ENOENT); 2281 sprintf(tmp, "%d", task_tgid_nr_ns(current, ns)); 2282 return ERR_PTR(vfs_follow_link(nd,tmp)); 2283 } 2284 2285 static const struct inode_operations proc_self_inode_operations = { 2286 .readlink = proc_self_readlink, 2287 .follow_link = proc_self_follow_link, 2288 }; 2289 2290 /* 2291 * proc base 2292 * 2293 * These are the directory entries in the root directory of /proc 2294 * that properly belong to the /proc filesystem, as they describe 2295 * describe something that is process related. 2296 */ 2297 static const struct pid_entry proc_base_stuff[] = { 2298 NOD("self", S_IFLNK|S_IRWXUGO, 2299 &proc_self_inode_operations, NULL, {}), 2300 }; 2301 2302 /* 2303 * Exceptional case: normally we are not allowed to unhash a busy 2304 * directory. In this case, however, we can do it - no aliasing problems 2305 * due to the way we treat inodes. 2306 */ 2307 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) 2308 { 2309 struct inode *inode = dentry->d_inode; 2310 struct task_struct *task = get_proc_task(inode); 2311 if (task) { 2312 put_task_struct(task); 2313 return 1; 2314 } 2315 d_drop(dentry); 2316 return 0; 2317 } 2318 2319 static struct dentry_operations proc_base_dentry_operations = 2320 { 2321 .d_revalidate = proc_base_revalidate, 2322 .d_delete = pid_delete_dentry, 2323 }; 2324 2325 static struct dentry *proc_base_instantiate(struct inode *dir, 2326 struct dentry *dentry, struct task_struct *task, const void *ptr) 2327 { 2328 const struct pid_entry *p = ptr; 2329 struct inode *inode; 2330 struct proc_inode *ei; 2331 struct dentry *error = ERR_PTR(-EINVAL); 2332 2333 /* Allocate the inode */ 2334 error = ERR_PTR(-ENOMEM); 2335 inode = new_inode(dir->i_sb); 2336 if (!inode) 2337 goto out; 2338 2339 /* Initialize the inode */ 2340 ei = PROC_I(inode); 2341 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2342 2343 /* 2344 * grab the reference to the task. 2345 */ 2346 ei->pid = get_task_pid(task, PIDTYPE_PID); 2347 if (!ei->pid) 2348 goto out_iput; 2349 2350 inode->i_mode = p->mode; 2351 if (S_ISDIR(inode->i_mode)) 2352 inode->i_nlink = 2; 2353 if (S_ISLNK(inode->i_mode)) 2354 inode->i_size = 64; 2355 if (p->iop) 2356 inode->i_op = p->iop; 2357 if (p->fop) 2358 inode->i_fop = p->fop; 2359 ei->op = p->op; 2360 dentry->d_op = &proc_base_dentry_operations; 2361 d_add(dentry, inode); 2362 error = NULL; 2363 out: 2364 return error; 2365 out_iput: 2366 iput(inode); 2367 goto out; 2368 } 2369 2370 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2371 { 2372 struct dentry *error; 2373 struct task_struct *task = get_proc_task(dir); 2374 const struct pid_entry *p, *last; 2375 2376 error = ERR_PTR(-ENOENT); 2377 2378 if (!task) 2379 goto out_no_task; 2380 2381 /* Lookup the directory entry */ 2382 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2383 for (p = proc_base_stuff; p <= last; p++) { 2384 if (p->len != dentry->d_name.len) 2385 continue; 2386 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2387 break; 2388 } 2389 if (p > last) 2390 goto out; 2391 2392 error = proc_base_instantiate(dir, dentry, task, p); 2393 2394 out: 2395 put_task_struct(task); 2396 out_no_task: 2397 return error; 2398 } 2399 2400 static int proc_base_fill_cache(struct file *filp, void *dirent, 2401 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2402 { 2403 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2404 proc_base_instantiate, task, p); 2405 } 2406 2407 #ifdef CONFIG_TASK_IO_ACCOUNTING 2408 static int do_io_accounting(struct task_struct *task, char *buffer, int whole) 2409 { 2410 struct task_io_accounting acct = task->ioac; 2411 unsigned long flags; 2412 2413 if (whole && lock_task_sighand(task, &flags)) { 2414 struct task_struct *t = task; 2415 2416 task_io_accounting_add(&acct, &task->signal->ioac); 2417 while_each_thread(task, t) 2418 task_io_accounting_add(&acct, &t->ioac); 2419 2420 unlock_task_sighand(task, &flags); 2421 } 2422 return sprintf(buffer, 2423 "rchar: %llu\n" 2424 "wchar: %llu\n" 2425 "syscr: %llu\n" 2426 "syscw: %llu\n" 2427 "read_bytes: %llu\n" 2428 "write_bytes: %llu\n" 2429 "cancelled_write_bytes: %llu\n", 2430 (unsigned long long)acct.rchar, 2431 (unsigned long long)acct.wchar, 2432 (unsigned long long)acct.syscr, 2433 (unsigned long long)acct.syscw, 2434 (unsigned long long)acct.read_bytes, 2435 (unsigned long long)acct.write_bytes, 2436 (unsigned long long)acct.cancelled_write_bytes); 2437 } 2438 2439 static int proc_tid_io_accounting(struct task_struct *task, char *buffer) 2440 { 2441 return do_io_accounting(task, buffer, 0); 2442 } 2443 2444 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer) 2445 { 2446 return do_io_accounting(task, buffer, 1); 2447 } 2448 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2449 2450 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2451 struct pid *pid, struct task_struct *task) 2452 { 2453 seq_printf(m, "%08x\n", task->personality); 2454 return 0; 2455 } 2456 2457 /* 2458 * Thread groups 2459 */ 2460 static const struct file_operations proc_task_operations; 2461 static const struct inode_operations proc_task_inode_operations; 2462 2463 static const struct pid_entry tgid_base_stuff[] = { 2464 DIR("task", S_IRUGO|S_IXUGO, task), 2465 DIR("fd", S_IRUSR|S_IXUSR, fd), 2466 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), 2467 #ifdef CONFIG_NET 2468 DIR("net", S_IRUGO|S_IXUGO, net), 2469 #endif 2470 REG("environ", S_IRUSR, environ), 2471 INF("auxv", S_IRUSR, pid_auxv), 2472 ONE("status", S_IRUGO, pid_status), 2473 ONE("personality", S_IRUSR, pid_personality), 2474 INF("limits", S_IRUSR, pid_limits), 2475 #ifdef CONFIG_SCHED_DEBUG 2476 REG("sched", S_IRUGO|S_IWUSR, pid_sched), 2477 #endif 2478 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2479 INF("syscall", S_IRUSR, pid_syscall), 2480 #endif 2481 INF("cmdline", S_IRUGO, pid_cmdline), 2482 ONE("stat", S_IRUGO, tgid_stat), 2483 ONE("statm", S_IRUGO, pid_statm), 2484 REG("maps", S_IRUGO, maps), 2485 #ifdef CONFIG_NUMA 2486 REG("numa_maps", S_IRUGO, numa_maps), 2487 #endif 2488 REG("mem", S_IRUSR|S_IWUSR, mem), 2489 LNK("cwd", cwd), 2490 LNK("root", root), 2491 LNK("exe", exe), 2492 REG("mounts", S_IRUGO, mounts), 2493 REG("mountinfo", S_IRUGO, mountinfo), 2494 REG("mountstats", S_IRUSR, mountstats), 2495 #ifdef CONFIG_PROC_PAGE_MONITOR 2496 REG("clear_refs", S_IWUSR, clear_refs), 2497 REG("smaps", S_IRUGO, smaps), 2498 REG("pagemap", S_IRUSR, pagemap), 2499 #endif 2500 #ifdef CONFIG_SECURITY 2501 DIR("attr", S_IRUGO|S_IXUGO, attr_dir), 2502 #endif 2503 #ifdef CONFIG_KALLSYMS 2504 INF("wchan", S_IRUGO, pid_wchan), 2505 #endif 2506 #ifdef CONFIG_SCHEDSTATS 2507 INF("schedstat", S_IRUGO, pid_schedstat), 2508 #endif 2509 #ifdef CONFIG_LATENCYTOP 2510 REG("latency", S_IRUGO, lstats), 2511 #endif 2512 #ifdef CONFIG_PROC_PID_CPUSET 2513 REG("cpuset", S_IRUGO, cpuset), 2514 #endif 2515 #ifdef CONFIG_CGROUPS 2516 REG("cgroup", S_IRUGO, cgroup), 2517 #endif 2518 INF("oom_score", S_IRUGO, oom_score), 2519 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust), 2520 #ifdef CONFIG_AUDITSYSCALL 2521 REG("loginuid", S_IWUSR|S_IRUGO, loginuid), 2522 REG("sessionid", S_IRUGO, sessionid), 2523 #endif 2524 #ifdef CONFIG_FAULT_INJECTION 2525 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject), 2526 #endif 2527 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2528 REG("coredump_filter", S_IRUGO|S_IWUSR, coredump_filter), 2529 #endif 2530 #ifdef CONFIG_TASK_IO_ACCOUNTING 2531 INF("io", S_IRUGO, tgid_io_accounting), 2532 #endif 2533 }; 2534 2535 static int proc_tgid_base_readdir(struct file * filp, 2536 void * dirent, filldir_t filldir) 2537 { 2538 return proc_pident_readdir(filp,dirent,filldir, 2539 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2540 } 2541 2542 static const struct file_operations proc_tgid_base_operations = { 2543 .read = generic_read_dir, 2544 .readdir = proc_tgid_base_readdir, 2545 }; 2546 2547 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2548 return proc_pident_lookup(dir, dentry, 2549 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2550 } 2551 2552 static const struct inode_operations proc_tgid_base_inode_operations = { 2553 .lookup = proc_tgid_base_lookup, 2554 .getattr = pid_getattr, 2555 .setattr = proc_setattr, 2556 }; 2557 2558 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2559 { 2560 struct dentry *dentry, *leader, *dir; 2561 char buf[PROC_NUMBUF]; 2562 struct qstr name; 2563 2564 name.name = buf; 2565 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2566 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2567 if (dentry) { 2568 if (!(current->flags & PF_EXITING)) 2569 shrink_dcache_parent(dentry); 2570 d_drop(dentry); 2571 dput(dentry); 2572 } 2573 2574 if (tgid == 0) 2575 goto out; 2576 2577 name.name = buf; 2578 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2579 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2580 if (!leader) 2581 goto out; 2582 2583 name.name = "task"; 2584 name.len = strlen(name.name); 2585 dir = d_hash_and_lookup(leader, &name); 2586 if (!dir) 2587 goto out_put_leader; 2588 2589 name.name = buf; 2590 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2591 dentry = d_hash_and_lookup(dir, &name); 2592 if (dentry) { 2593 shrink_dcache_parent(dentry); 2594 d_drop(dentry); 2595 dput(dentry); 2596 } 2597 2598 dput(dir); 2599 out_put_leader: 2600 dput(leader); 2601 out: 2602 return; 2603 } 2604 2605 /** 2606 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2607 * @task: task that should be flushed. 2608 * 2609 * When flushing dentries from proc, one needs to flush them from global 2610 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2611 * in. This call is supposed to do all of this job. 2612 * 2613 * Looks in the dcache for 2614 * /proc/@pid 2615 * /proc/@tgid/task/@pid 2616 * if either directory is present flushes it and all of it'ts children 2617 * from the dcache. 2618 * 2619 * It is safe and reasonable to cache /proc entries for a task until 2620 * that task exits. After that they just clog up the dcache with 2621 * useless entries, possibly causing useful dcache entries to be 2622 * flushed instead. This routine is proved to flush those useless 2623 * dcache entries at process exit time. 2624 * 2625 * NOTE: This routine is just an optimization so it does not guarantee 2626 * that no dcache entries will exist at process exit time it 2627 * just makes it very unlikely that any will persist. 2628 */ 2629 2630 void proc_flush_task(struct task_struct *task) 2631 { 2632 int i; 2633 struct pid *pid, *tgid = NULL; 2634 struct upid *upid; 2635 2636 pid = task_pid(task); 2637 if (thread_group_leader(task)) 2638 tgid = task_tgid(task); 2639 2640 for (i = 0; i <= pid->level; i++) { 2641 upid = &pid->numbers[i]; 2642 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 2643 tgid ? tgid->numbers[i].nr : 0); 2644 } 2645 2646 upid = &pid->numbers[pid->level]; 2647 if (upid->nr == 1) 2648 pid_ns_release_proc(upid->ns); 2649 } 2650 2651 static struct dentry *proc_pid_instantiate(struct inode *dir, 2652 struct dentry * dentry, 2653 struct task_struct *task, const void *ptr) 2654 { 2655 struct dentry *error = ERR_PTR(-ENOENT); 2656 struct inode *inode; 2657 2658 inode = proc_pid_make_inode(dir->i_sb, task); 2659 if (!inode) 2660 goto out; 2661 2662 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2663 inode->i_op = &proc_tgid_base_inode_operations; 2664 inode->i_fop = &proc_tgid_base_operations; 2665 inode->i_flags|=S_IMMUTABLE; 2666 2667 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff, 2668 ARRAY_SIZE(tgid_base_stuff)); 2669 2670 dentry->d_op = &pid_dentry_operations; 2671 2672 d_add(dentry, inode); 2673 /* Close the race of the process dying before we return the dentry */ 2674 if (pid_revalidate(dentry, NULL)) 2675 error = NULL; 2676 out: 2677 return error; 2678 } 2679 2680 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2681 { 2682 struct dentry *result = ERR_PTR(-ENOENT); 2683 struct task_struct *task; 2684 unsigned tgid; 2685 struct pid_namespace *ns; 2686 2687 result = proc_base_lookup(dir, dentry); 2688 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 2689 goto out; 2690 2691 tgid = name_to_int(dentry); 2692 if (tgid == ~0U) 2693 goto out; 2694 2695 ns = dentry->d_sb->s_fs_info; 2696 rcu_read_lock(); 2697 task = find_task_by_pid_ns(tgid, ns); 2698 if (task) 2699 get_task_struct(task); 2700 rcu_read_unlock(); 2701 if (!task) 2702 goto out; 2703 2704 result = proc_pid_instantiate(dir, dentry, task, NULL); 2705 put_task_struct(task); 2706 out: 2707 return result; 2708 } 2709 2710 /* 2711 * Find the first task with tgid >= tgid 2712 * 2713 */ 2714 struct tgid_iter { 2715 unsigned int tgid; 2716 struct task_struct *task; 2717 }; 2718 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 2719 { 2720 struct pid *pid; 2721 2722 if (iter.task) 2723 put_task_struct(iter.task); 2724 rcu_read_lock(); 2725 retry: 2726 iter.task = NULL; 2727 pid = find_ge_pid(iter.tgid, ns); 2728 if (pid) { 2729 iter.tgid = pid_nr_ns(pid, ns); 2730 iter.task = pid_task(pid, PIDTYPE_PID); 2731 /* What we to know is if the pid we have find is the 2732 * pid of a thread_group_leader. Testing for task 2733 * being a thread_group_leader is the obvious thing 2734 * todo but there is a window when it fails, due to 2735 * the pid transfer logic in de_thread. 2736 * 2737 * So we perform the straight forward test of seeing 2738 * if the pid we have found is the pid of a thread 2739 * group leader, and don't worry if the task we have 2740 * found doesn't happen to be a thread group leader. 2741 * As we don't care in the case of readdir. 2742 */ 2743 if (!iter.task || !has_group_leader_pid(iter.task)) { 2744 iter.tgid += 1; 2745 goto retry; 2746 } 2747 get_task_struct(iter.task); 2748 } 2749 rcu_read_unlock(); 2750 return iter; 2751 } 2752 2753 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 2754 2755 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2756 struct tgid_iter iter) 2757 { 2758 char name[PROC_NUMBUF]; 2759 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 2760 return proc_fill_cache(filp, dirent, filldir, name, len, 2761 proc_pid_instantiate, iter.task, NULL); 2762 } 2763 2764 /* for the /proc/ directory itself, after non-process stuff has been done */ 2765 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 2766 { 2767 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; 2768 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode); 2769 struct tgid_iter iter; 2770 struct pid_namespace *ns; 2771 2772 if (!reaper) 2773 goto out_no_task; 2774 2775 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 2776 const struct pid_entry *p = &proc_base_stuff[nr]; 2777 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 2778 goto out; 2779 } 2780 2781 ns = filp->f_dentry->d_sb->s_fs_info; 2782 iter.task = NULL; 2783 iter.tgid = filp->f_pos - TGID_OFFSET; 2784 for (iter = next_tgid(ns, iter); 2785 iter.task; 2786 iter.tgid += 1, iter = next_tgid(ns, iter)) { 2787 filp->f_pos = iter.tgid + TGID_OFFSET; 2788 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) { 2789 put_task_struct(iter.task); 2790 goto out; 2791 } 2792 } 2793 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 2794 out: 2795 put_task_struct(reaper); 2796 out_no_task: 2797 return 0; 2798 } 2799 2800 /* 2801 * Tasks 2802 */ 2803 static const struct pid_entry tid_base_stuff[] = { 2804 DIR("fd", S_IRUSR|S_IXUSR, fd), 2805 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), 2806 REG("environ", S_IRUSR, environ), 2807 INF("auxv", S_IRUSR, pid_auxv), 2808 ONE("status", S_IRUGO, pid_status), 2809 ONE("personality", S_IRUSR, pid_personality), 2810 INF("limits", S_IRUSR, pid_limits), 2811 #ifdef CONFIG_SCHED_DEBUG 2812 REG("sched", S_IRUGO|S_IWUSR, pid_sched), 2813 #endif 2814 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2815 INF("syscall", S_IRUSR, pid_syscall), 2816 #endif 2817 INF("cmdline", S_IRUGO, pid_cmdline), 2818 ONE("stat", S_IRUGO, tid_stat), 2819 ONE("statm", S_IRUGO, pid_statm), 2820 REG("maps", S_IRUGO, maps), 2821 #ifdef CONFIG_NUMA 2822 REG("numa_maps", S_IRUGO, numa_maps), 2823 #endif 2824 REG("mem", S_IRUSR|S_IWUSR, mem), 2825 LNK("cwd", cwd), 2826 LNK("root", root), 2827 LNK("exe", exe), 2828 REG("mounts", S_IRUGO, mounts), 2829 REG("mountinfo", S_IRUGO, mountinfo), 2830 #ifdef CONFIG_PROC_PAGE_MONITOR 2831 REG("clear_refs", S_IWUSR, clear_refs), 2832 REG("smaps", S_IRUGO, smaps), 2833 REG("pagemap", S_IRUSR, pagemap), 2834 #endif 2835 #ifdef CONFIG_SECURITY 2836 DIR("attr", S_IRUGO|S_IXUGO, attr_dir), 2837 #endif 2838 #ifdef CONFIG_KALLSYMS 2839 INF("wchan", S_IRUGO, pid_wchan), 2840 #endif 2841 #ifdef CONFIG_SCHEDSTATS 2842 INF("schedstat", S_IRUGO, pid_schedstat), 2843 #endif 2844 #ifdef CONFIG_LATENCYTOP 2845 REG("latency", S_IRUGO, lstats), 2846 #endif 2847 #ifdef CONFIG_PROC_PID_CPUSET 2848 REG("cpuset", S_IRUGO, cpuset), 2849 #endif 2850 #ifdef CONFIG_CGROUPS 2851 REG("cgroup", S_IRUGO, cgroup), 2852 #endif 2853 INF("oom_score", S_IRUGO, oom_score), 2854 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust), 2855 #ifdef CONFIG_AUDITSYSCALL 2856 REG("loginuid", S_IWUSR|S_IRUGO, loginuid), 2857 REG("sessionid", S_IRUSR, sessionid), 2858 #endif 2859 #ifdef CONFIG_FAULT_INJECTION 2860 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject), 2861 #endif 2862 #ifdef CONFIG_TASK_IO_ACCOUNTING 2863 INF("io", S_IRUGO, tid_io_accounting), 2864 #endif 2865 }; 2866 2867 static int proc_tid_base_readdir(struct file * filp, 2868 void * dirent, filldir_t filldir) 2869 { 2870 return proc_pident_readdir(filp,dirent,filldir, 2871 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 2872 } 2873 2874 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2875 return proc_pident_lookup(dir, dentry, 2876 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 2877 } 2878 2879 static const struct file_operations proc_tid_base_operations = { 2880 .read = generic_read_dir, 2881 .readdir = proc_tid_base_readdir, 2882 }; 2883 2884 static const struct inode_operations proc_tid_base_inode_operations = { 2885 .lookup = proc_tid_base_lookup, 2886 .getattr = pid_getattr, 2887 .setattr = proc_setattr, 2888 }; 2889 2890 static struct dentry *proc_task_instantiate(struct inode *dir, 2891 struct dentry *dentry, struct task_struct *task, const void *ptr) 2892 { 2893 struct dentry *error = ERR_PTR(-ENOENT); 2894 struct inode *inode; 2895 inode = proc_pid_make_inode(dir->i_sb, task); 2896 2897 if (!inode) 2898 goto out; 2899 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2900 inode->i_op = &proc_tid_base_inode_operations; 2901 inode->i_fop = &proc_tid_base_operations; 2902 inode->i_flags|=S_IMMUTABLE; 2903 2904 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff, 2905 ARRAY_SIZE(tid_base_stuff)); 2906 2907 dentry->d_op = &pid_dentry_operations; 2908 2909 d_add(dentry, inode); 2910 /* Close the race of the process dying before we return the dentry */ 2911 if (pid_revalidate(dentry, NULL)) 2912 error = NULL; 2913 out: 2914 return error; 2915 } 2916 2917 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2918 { 2919 struct dentry *result = ERR_PTR(-ENOENT); 2920 struct task_struct *task; 2921 struct task_struct *leader = get_proc_task(dir); 2922 unsigned tid; 2923 struct pid_namespace *ns; 2924 2925 if (!leader) 2926 goto out_no_task; 2927 2928 tid = name_to_int(dentry); 2929 if (tid == ~0U) 2930 goto out; 2931 2932 ns = dentry->d_sb->s_fs_info; 2933 rcu_read_lock(); 2934 task = find_task_by_pid_ns(tid, ns); 2935 if (task) 2936 get_task_struct(task); 2937 rcu_read_unlock(); 2938 if (!task) 2939 goto out; 2940 if (!same_thread_group(leader, task)) 2941 goto out_drop_task; 2942 2943 result = proc_task_instantiate(dir, dentry, task, NULL); 2944 out_drop_task: 2945 put_task_struct(task); 2946 out: 2947 put_task_struct(leader); 2948 out_no_task: 2949 return result; 2950 } 2951 2952 /* 2953 * Find the first tid of a thread group to return to user space. 2954 * 2955 * Usually this is just the thread group leader, but if the users 2956 * buffer was too small or there was a seek into the middle of the 2957 * directory we have more work todo. 2958 * 2959 * In the case of a short read we start with find_task_by_pid. 2960 * 2961 * In the case of a seek we start with the leader and walk nr 2962 * threads past it. 2963 */ 2964 static struct task_struct *first_tid(struct task_struct *leader, 2965 int tid, int nr, struct pid_namespace *ns) 2966 { 2967 struct task_struct *pos; 2968 2969 rcu_read_lock(); 2970 /* Attempt to start with the pid of a thread */ 2971 if (tid && (nr > 0)) { 2972 pos = find_task_by_pid_ns(tid, ns); 2973 if (pos && (pos->group_leader == leader)) 2974 goto found; 2975 } 2976 2977 /* If nr exceeds the number of threads there is nothing todo */ 2978 pos = NULL; 2979 if (nr && nr >= get_nr_threads(leader)) 2980 goto out; 2981 2982 /* If we haven't found our starting place yet start 2983 * with the leader and walk nr threads forward. 2984 */ 2985 for (pos = leader; nr > 0; --nr) { 2986 pos = next_thread(pos); 2987 if (pos == leader) { 2988 pos = NULL; 2989 goto out; 2990 } 2991 } 2992 found: 2993 get_task_struct(pos); 2994 out: 2995 rcu_read_unlock(); 2996 return pos; 2997 } 2998 2999 /* 3000 * Find the next thread in the thread list. 3001 * Return NULL if there is an error or no next thread. 3002 * 3003 * The reference to the input task_struct is released. 3004 */ 3005 static struct task_struct *next_tid(struct task_struct *start) 3006 { 3007 struct task_struct *pos = NULL; 3008 rcu_read_lock(); 3009 if (pid_alive(start)) { 3010 pos = next_thread(start); 3011 if (thread_group_leader(pos)) 3012 pos = NULL; 3013 else 3014 get_task_struct(pos); 3015 } 3016 rcu_read_unlock(); 3017 put_task_struct(start); 3018 return pos; 3019 } 3020 3021 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3022 struct task_struct *task, int tid) 3023 { 3024 char name[PROC_NUMBUF]; 3025 int len = snprintf(name, sizeof(name), "%d", tid); 3026 return proc_fill_cache(filp, dirent, filldir, name, len, 3027 proc_task_instantiate, task, NULL); 3028 } 3029 3030 /* for the /proc/TGID/task/ directories */ 3031 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 3032 { 3033 struct dentry *dentry = filp->f_path.dentry; 3034 struct inode *inode = dentry->d_inode; 3035 struct task_struct *leader = NULL; 3036 struct task_struct *task; 3037 int retval = -ENOENT; 3038 ino_t ino; 3039 int tid; 3040 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */ 3041 struct pid_namespace *ns; 3042 3043 task = get_proc_task(inode); 3044 if (!task) 3045 goto out_no_task; 3046 rcu_read_lock(); 3047 if (pid_alive(task)) { 3048 leader = task->group_leader; 3049 get_task_struct(leader); 3050 } 3051 rcu_read_unlock(); 3052 put_task_struct(task); 3053 if (!leader) 3054 goto out_no_task; 3055 retval = 0; 3056 3057 switch (pos) { 3058 case 0: 3059 ino = inode->i_ino; 3060 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0) 3061 goto out; 3062 pos++; 3063 /* fall through */ 3064 case 1: 3065 ino = parent_ino(dentry); 3066 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0) 3067 goto out; 3068 pos++; 3069 /* fall through */ 3070 } 3071 3072 /* f_version caches the tgid value that the last readdir call couldn't 3073 * return. lseek aka telldir automagically resets f_version to 0. 3074 */ 3075 ns = filp->f_dentry->d_sb->s_fs_info; 3076 tid = (int)filp->f_version; 3077 filp->f_version = 0; 3078 for (task = first_tid(leader, tid, pos - 2, ns); 3079 task; 3080 task = next_tid(task), pos++) { 3081 tid = task_pid_nr_ns(task, ns); 3082 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 3083 /* returning this tgid failed, save it as the first 3084 * pid for the next readir call */ 3085 filp->f_version = (u64)tid; 3086 put_task_struct(task); 3087 break; 3088 } 3089 } 3090 out: 3091 filp->f_pos = pos; 3092 put_task_struct(leader); 3093 out_no_task: 3094 return retval; 3095 } 3096 3097 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3098 { 3099 struct inode *inode = dentry->d_inode; 3100 struct task_struct *p = get_proc_task(inode); 3101 generic_fillattr(inode, stat); 3102 3103 if (p) { 3104 stat->nlink += get_nr_threads(p); 3105 put_task_struct(p); 3106 } 3107 3108 return 0; 3109 } 3110 3111 static const struct inode_operations proc_task_inode_operations = { 3112 .lookup = proc_task_lookup, 3113 .getattr = proc_task_getattr, 3114 .setattr = proc_setattr, 3115 }; 3116 3117 static const struct file_operations proc_task_operations = { 3118 .read = generic_read_dir, 3119 .readdir = proc_task_readdir, 3120 }; 3121