1 /* 2 * linux/fs/proc/base.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 * 6 * proc base directory handling functions 7 * 8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part. 9 * Instead of using magical inumbers to determine the kind of object 10 * we allocate and fill in-core inodes upon lookup. They don't even 11 * go into icache. We cache the reference to task_struct upon lookup too. 12 * Eventually it should become a filesystem in its own. We don't use the 13 * rest of procfs anymore. 14 * 15 * 16 * Changelog: 17 * 17-Jan-2005 18 * Allan Bezerra 19 * Bruna Moreira <bruna.moreira@indt.org.br> 20 * Edjard Mota <edjard.mota@indt.org.br> 21 * Ilias Biris <ilias.biris@indt.org.br> 22 * Mauricio Lin <mauricio.lin@indt.org.br> 23 * 24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 25 * 26 * A new process specific entry (smaps) included in /proc. It shows the 27 * size of rss for each memory area. The maps entry lacks information 28 * about physical memory size (rss) for each mapped file, i.e., 29 * rss information for executables and library files. 30 * This additional information is useful for any tools that need to know 31 * about physical memory consumption for a process specific library. 32 * 33 * Changelog: 34 * 21-Feb-2005 35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 36 * Pud inclusion in the page table walking. 37 * 38 * ChangeLog: 39 * 10-Mar-2005 40 * 10LE Instituto Nokia de Tecnologia - INdT: 41 * A better way to walks through the page table as suggested by Hugh Dickins. 42 * 43 * Simo Piiroinen <simo.piiroinen@nokia.com>: 44 * Smaps information related to shared, private, clean and dirty pages. 45 * 46 * Paul Mundt <paul.mundt@nokia.com>: 47 * Overall revision about smaps. 48 */ 49 50 #include <asm/uaccess.h> 51 52 #include <linux/errno.h> 53 #include <linux/time.h> 54 #include <linux/proc_fs.h> 55 #include <linux/stat.h> 56 #include <linux/task_io_accounting_ops.h> 57 #include <linux/init.h> 58 #include <linux/capability.h> 59 #include <linux/file.h> 60 #include <linux/fdtable.h> 61 #include <linux/string.h> 62 #include <linux/seq_file.h> 63 #include <linux/namei.h> 64 #include <linux/mnt_namespace.h> 65 #include <linux/mm.h> 66 #include <linux/rcupdate.h> 67 #include <linux/kallsyms.h> 68 #include <linux/stacktrace.h> 69 #include <linux/resource.h> 70 #include <linux/module.h> 71 #include <linux/mount.h> 72 #include <linux/security.h> 73 #include <linux/ptrace.h> 74 #include <linux/tracehook.h> 75 #include <linux/cgroup.h> 76 #include <linux/cpuset.h> 77 #include <linux/audit.h> 78 #include <linux/poll.h> 79 #include <linux/nsproxy.h> 80 #include <linux/oom.h> 81 #include <linux/elf.h> 82 #include <linux/pid_namespace.h> 83 #include "internal.h" 84 85 /* NOTE: 86 * Implementing inode permission operations in /proc is almost 87 * certainly an error. Permission checks need to happen during 88 * each system call not at open time. The reason is that most of 89 * what we wish to check for permissions in /proc varies at runtime. 90 * 91 * The classic example of a problem is opening file descriptors 92 * in /proc for a task before it execs a suid executable. 93 */ 94 95 struct pid_entry { 96 char *name; 97 int len; 98 mode_t mode; 99 const struct inode_operations *iop; 100 const struct file_operations *fop; 101 union proc_op op; 102 }; 103 104 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 105 .name = (NAME), \ 106 .len = sizeof(NAME) - 1, \ 107 .mode = MODE, \ 108 .iop = IOP, \ 109 .fop = FOP, \ 110 .op = OP, \ 111 } 112 113 #define DIR(NAME, MODE, iops, fops) \ 114 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} ) 115 #define LNK(NAME, get_link) \ 116 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 117 &proc_pid_link_inode_operations, NULL, \ 118 { .proc_get_link = get_link } ) 119 #define REG(NAME, MODE, fops) \ 120 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {}) 121 #define INF(NAME, MODE, read) \ 122 NOD(NAME, (S_IFREG|(MODE)), \ 123 NULL, &proc_info_file_operations, \ 124 { .proc_read = read } ) 125 #define ONE(NAME, MODE, show) \ 126 NOD(NAME, (S_IFREG|(MODE)), \ 127 NULL, &proc_single_file_operations, \ 128 { .proc_show = show } ) 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 static struct fs_struct *get_fs_struct(struct task_struct *task) 150 { 151 struct fs_struct *fs; 152 task_lock(task); 153 fs = task->fs; 154 if(fs) 155 atomic_inc(&fs->count); 156 task_unlock(task); 157 return fs; 158 } 159 160 static int get_nr_threads(struct task_struct *tsk) 161 { 162 unsigned long flags; 163 int count = 0; 164 165 if (lock_task_sighand(tsk, &flags)) { 166 count = atomic_read(&tsk->signal->count); 167 unlock_task_sighand(tsk, &flags); 168 } 169 return count; 170 } 171 172 static int proc_cwd_link(struct inode *inode, struct path *path) 173 { 174 struct task_struct *task = get_proc_task(inode); 175 struct fs_struct *fs = NULL; 176 int result = -ENOENT; 177 178 if (task) { 179 fs = get_fs_struct(task); 180 put_task_struct(task); 181 } 182 if (fs) { 183 read_lock(&fs->lock); 184 *path = fs->pwd; 185 path_get(&fs->pwd); 186 read_unlock(&fs->lock); 187 result = 0; 188 put_fs_struct(fs); 189 } 190 return result; 191 } 192 193 static int proc_root_link(struct inode *inode, struct path *path) 194 { 195 struct task_struct *task = get_proc_task(inode); 196 struct fs_struct *fs = NULL; 197 int result = -ENOENT; 198 199 if (task) { 200 fs = get_fs_struct(task); 201 put_task_struct(task); 202 } 203 if (fs) { 204 read_lock(&fs->lock); 205 *path = fs->root; 206 path_get(&fs->root); 207 read_unlock(&fs->lock); 208 result = 0; 209 put_fs_struct(fs); 210 } 211 return result; 212 } 213 214 /* 215 * Return zero if current may access user memory in @task, -error if not. 216 */ 217 static int check_mem_permission(struct task_struct *task) 218 { 219 /* 220 * A task can always look at itself, in case it chooses 221 * to use system calls instead of load instructions. 222 */ 223 if (task == current) 224 return 0; 225 226 /* 227 * If current is actively ptrace'ing, and would also be 228 * permitted to freshly attach with ptrace now, permit it. 229 */ 230 if (task_is_stopped_or_traced(task)) { 231 int match; 232 rcu_read_lock(); 233 match = (tracehook_tracer_task(task) == current); 234 rcu_read_unlock(); 235 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH)) 236 return 0; 237 } 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_STACKTRACE 342 343 #define MAX_STACK_TRACE_DEPTH 64 344 345 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, 346 struct pid *pid, struct task_struct *task) 347 { 348 struct stack_trace trace; 349 unsigned long *entries; 350 int i; 351 352 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL); 353 if (!entries) 354 return -ENOMEM; 355 356 trace.nr_entries = 0; 357 trace.max_entries = MAX_STACK_TRACE_DEPTH; 358 trace.entries = entries; 359 trace.skip = 0; 360 save_stack_trace_tsk(task, &trace); 361 362 for (i = 0; i < trace.nr_entries; i++) { 363 seq_printf(m, "[<%p>] %pS\n", 364 (void *)entries[i], (void *)entries[i]); 365 } 366 kfree(entries); 367 368 return 0; 369 } 370 #endif 371 372 #ifdef CONFIG_SCHEDSTATS 373 /* 374 * Provides /proc/PID/schedstat 375 */ 376 static int proc_pid_schedstat(struct task_struct *task, char *buffer) 377 { 378 return sprintf(buffer, "%llu %llu %lu\n", 379 (unsigned long long)task->se.sum_exec_runtime, 380 (unsigned long long)task->sched_info.run_delay, 381 task->sched_info.pcount); 382 } 383 #endif 384 385 #ifdef CONFIG_LATENCYTOP 386 static int lstats_show_proc(struct seq_file *m, void *v) 387 { 388 int i; 389 struct inode *inode = m->private; 390 struct task_struct *task = get_proc_task(inode); 391 392 if (!task) 393 return -ESRCH; 394 seq_puts(m, "Latency Top version : v0.1\n"); 395 for (i = 0; i < 32; i++) { 396 if (task->latency_record[i].backtrace[0]) { 397 int q; 398 seq_printf(m, "%i %li %li ", 399 task->latency_record[i].count, 400 task->latency_record[i].time, 401 task->latency_record[i].max); 402 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 403 char sym[KSYM_SYMBOL_LEN]; 404 char *c; 405 if (!task->latency_record[i].backtrace[q]) 406 break; 407 if (task->latency_record[i].backtrace[q] == ULONG_MAX) 408 break; 409 sprint_symbol(sym, task->latency_record[i].backtrace[q]); 410 c = strchr(sym, '+'); 411 if (c) 412 *c = 0; 413 seq_printf(m, "%s ", sym); 414 } 415 seq_printf(m, "\n"); 416 } 417 418 } 419 put_task_struct(task); 420 return 0; 421 } 422 423 static int lstats_open(struct inode *inode, struct file *file) 424 { 425 return single_open(file, lstats_show_proc, inode); 426 } 427 428 static ssize_t lstats_write(struct file *file, const char __user *buf, 429 size_t count, loff_t *offs) 430 { 431 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 432 433 if (!task) 434 return -ESRCH; 435 clear_all_latency_tracing(task); 436 put_task_struct(task); 437 438 return count; 439 } 440 441 static const struct file_operations proc_lstats_operations = { 442 .open = lstats_open, 443 .read = seq_read, 444 .write = lstats_write, 445 .llseek = seq_lseek, 446 .release = single_release, 447 }; 448 449 #endif 450 451 /* The badness from the OOM killer */ 452 unsigned long badness(struct task_struct *p, unsigned long uptime); 453 static int proc_oom_score(struct task_struct *task, char *buffer) 454 { 455 unsigned long points; 456 struct timespec uptime; 457 458 do_posix_clock_monotonic_gettime(&uptime); 459 read_lock(&tasklist_lock); 460 points = badness(task, uptime.tv_sec); 461 read_unlock(&tasklist_lock); 462 return sprintf(buffer, "%lu\n", points); 463 } 464 465 struct limit_names { 466 char *name; 467 char *unit; 468 }; 469 470 static const struct limit_names lnames[RLIM_NLIMITS] = { 471 [RLIMIT_CPU] = {"Max cpu time", "ms"}, 472 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 473 [RLIMIT_DATA] = {"Max data size", "bytes"}, 474 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 475 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 476 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 477 [RLIMIT_NPROC] = {"Max processes", "processes"}, 478 [RLIMIT_NOFILE] = {"Max open files", "files"}, 479 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 480 [RLIMIT_AS] = {"Max address space", "bytes"}, 481 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 482 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 483 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 484 [RLIMIT_NICE] = {"Max nice priority", NULL}, 485 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 486 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 487 }; 488 489 /* Display limits for a process */ 490 static int proc_pid_limits(struct task_struct *task, char *buffer) 491 { 492 unsigned int i; 493 int count = 0; 494 unsigned long flags; 495 char *bufptr = buffer; 496 497 struct rlimit rlim[RLIM_NLIMITS]; 498 499 if (!lock_task_sighand(task, &flags)) 500 return 0; 501 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 502 unlock_task_sighand(task, &flags); 503 504 /* 505 * print the file header 506 */ 507 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n", 508 "Limit", "Soft Limit", "Hard Limit", "Units"); 509 510 for (i = 0; i < RLIM_NLIMITS; i++) { 511 if (rlim[i].rlim_cur == RLIM_INFINITY) 512 count += sprintf(&bufptr[count], "%-25s %-20s ", 513 lnames[i].name, "unlimited"); 514 else 515 count += sprintf(&bufptr[count], "%-25s %-20lu ", 516 lnames[i].name, rlim[i].rlim_cur); 517 518 if (rlim[i].rlim_max == RLIM_INFINITY) 519 count += sprintf(&bufptr[count], "%-20s ", "unlimited"); 520 else 521 count += sprintf(&bufptr[count], "%-20lu ", 522 rlim[i].rlim_max); 523 524 if (lnames[i].unit) 525 count += sprintf(&bufptr[count], "%-10s\n", 526 lnames[i].unit); 527 else 528 count += sprintf(&bufptr[count], "\n"); 529 } 530 531 return count; 532 } 533 534 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 535 static int proc_pid_syscall(struct task_struct *task, char *buffer) 536 { 537 long nr; 538 unsigned long args[6], sp, pc; 539 540 if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) 541 return sprintf(buffer, "running\n"); 542 543 if (nr < 0) 544 return sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc); 545 546 return sprintf(buffer, 547 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", 548 nr, 549 args[0], args[1], args[2], args[3], args[4], args[5], 550 sp, pc); 551 } 552 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 553 554 /************************************************************************/ 555 /* Here the fs part begins */ 556 /************************************************************************/ 557 558 /* permission checks */ 559 static int proc_fd_access_allowed(struct inode *inode) 560 { 561 struct task_struct *task; 562 int allowed = 0; 563 /* Allow access to a task's file descriptors if it is us or we 564 * may use ptrace attach to the process and find out that 565 * information. 566 */ 567 task = get_proc_task(inode); 568 if (task) { 569 allowed = ptrace_may_access(task, PTRACE_MODE_READ); 570 put_task_struct(task); 571 } 572 return allowed; 573 } 574 575 static int proc_setattr(struct dentry *dentry, struct iattr *attr) 576 { 577 int error; 578 struct inode *inode = dentry->d_inode; 579 580 if (attr->ia_valid & ATTR_MODE) 581 return -EPERM; 582 583 error = inode_change_ok(inode, attr); 584 if (!error) 585 error = inode_setattr(inode, attr); 586 return error; 587 } 588 589 static const struct inode_operations proc_def_inode_operations = { 590 .setattr = proc_setattr, 591 }; 592 593 static int mounts_open_common(struct inode *inode, struct file *file, 594 const struct seq_operations *op) 595 { 596 struct task_struct *task = get_proc_task(inode); 597 struct nsproxy *nsp; 598 struct mnt_namespace *ns = NULL; 599 struct fs_struct *fs = NULL; 600 struct path root; 601 struct proc_mounts *p; 602 int ret = -EINVAL; 603 604 if (task) { 605 rcu_read_lock(); 606 nsp = task_nsproxy(task); 607 if (nsp) { 608 ns = nsp->mnt_ns; 609 if (ns) 610 get_mnt_ns(ns); 611 } 612 rcu_read_unlock(); 613 if (ns) 614 fs = get_fs_struct(task); 615 put_task_struct(task); 616 } 617 618 if (!ns) 619 goto err; 620 if (!fs) 621 goto err_put_ns; 622 623 read_lock(&fs->lock); 624 root = fs->root; 625 path_get(&root); 626 read_unlock(&fs->lock); 627 put_fs_struct(fs); 628 629 ret = -ENOMEM; 630 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL); 631 if (!p) 632 goto err_put_path; 633 634 file->private_data = &p->m; 635 ret = seq_open(file, op); 636 if (ret) 637 goto err_free; 638 639 p->m.private = p; 640 p->ns = ns; 641 p->root = root; 642 p->event = ns->event; 643 644 return 0; 645 646 err_free: 647 kfree(p); 648 err_put_path: 649 path_put(&root); 650 err_put_ns: 651 put_mnt_ns(ns); 652 err: 653 return ret; 654 } 655 656 static int mounts_release(struct inode *inode, struct file *file) 657 { 658 struct proc_mounts *p = file->private_data; 659 path_put(&p->root); 660 put_mnt_ns(p->ns); 661 return seq_release(inode, file); 662 } 663 664 static unsigned mounts_poll(struct file *file, poll_table *wait) 665 { 666 struct proc_mounts *p = file->private_data; 667 struct mnt_namespace *ns = p->ns; 668 unsigned res = 0; 669 670 poll_wait(file, &ns->poll, wait); 671 672 spin_lock(&vfsmount_lock); 673 if (p->event != ns->event) { 674 p->event = ns->event; 675 res = POLLERR; 676 } 677 spin_unlock(&vfsmount_lock); 678 679 return res; 680 } 681 682 static int mounts_open(struct inode *inode, struct file *file) 683 { 684 return mounts_open_common(inode, file, &mounts_op); 685 } 686 687 static const struct file_operations proc_mounts_operations = { 688 .open = mounts_open, 689 .read = seq_read, 690 .llseek = seq_lseek, 691 .release = mounts_release, 692 .poll = mounts_poll, 693 }; 694 695 static int mountinfo_open(struct inode *inode, struct file *file) 696 { 697 return mounts_open_common(inode, file, &mountinfo_op); 698 } 699 700 static const struct file_operations proc_mountinfo_operations = { 701 .open = mountinfo_open, 702 .read = seq_read, 703 .llseek = seq_lseek, 704 .release = mounts_release, 705 .poll = mounts_poll, 706 }; 707 708 static int mountstats_open(struct inode *inode, struct file *file) 709 { 710 return mounts_open_common(inode, file, &mountstats_op); 711 } 712 713 static const struct file_operations proc_mountstats_operations = { 714 .open = mountstats_open, 715 .read = seq_read, 716 .llseek = seq_lseek, 717 .release = mounts_release, 718 }; 719 720 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */ 721 722 static ssize_t proc_info_read(struct file * file, char __user * buf, 723 size_t count, loff_t *ppos) 724 { 725 struct inode * inode = file->f_path.dentry->d_inode; 726 unsigned long page; 727 ssize_t length; 728 struct task_struct *task = get_proc_task(inode); 729 730 length = -ESRCH; 731 if (!task) 732 goto out_no_task; 733 734 if (count > PROC_BLOCK_SIZE) 735 count = PROC_BLOCK_SIZE; 736 737 length = -ENOMEM; 738 if (!(page = __get_free_page(GFP_TEMPORARY))) 739 goto out; 740 741 length = PROC_I(inode)->op.proc_read(task, (char*)page); 742 743 if (length >= 0) 744 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length); 745 free_page(page); 746 out: 747 put_task_struct(task); 748 out_no_task: 749 return length; 750 } 751 752 static const struct file_operations proc_info_file_operations = { 753 .read = proc_info_read, 754 }; 755 756 static int proc_single_show(struct seq_file *m, void *v) 757 { 758 struct inode *inode = m->private; 759 struct pid_namespace *ns; 760 struct pid *pid; 761 struct task_struct *task; 762 int ret; 763 764 ns = inode->i_sb->s_fs_info; 765 pid = proc_pid(inode); 766 task = get_pid_task(pid, PIDTYPE_PID); 767 if (!task) 768 return -ESRCH; 769 770 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 771 772 put_task_struct(task); 773 return ret; 774 } 775 776 static int proc_single_open(struct inode *inode, struct file *filp) 777 { 778 int ret; 779 ret = single_open(filp, proc_single_show, NULL); 780 if (!ret) { 781 struct seq_file *m = filp->private_data; 782 783 m->private = inode; 784 } 785 return ret; 786 } 787 788 static const struct file_operations proc_single_file_operations = { 789 .open = proc_single_open, 790 .read = seq_read, 791 .llseek = seq_lseek, 792 .release = single_release, 793 }; 794 795 static int mem_open(struct inode* inode, struct file* file) 796 { 797 file->private_data = (void*)((long)current->self_exec_id); 798 return 0; 799 } 800 801 static ssize_t mem_read(struct file * file, char __user * buf, 802 size_t count, loff_t *ppos) 803 { 804 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 805 char *page; 806 unsigned long src = *ppos; 807 int ret = -ESRCH; 808 struct mm_struct *mm; 809 810 if (!task) 811 goto out_no_task; 812 813 if (check_mem_permission(task)) 814 goto out; 815 816 ret = -ENOMEM; 817 page = (char *)__get_free_page(GFP_TEMPORARY); 818 if (!page) 819 goto out; 820 821 ret = 0; 822 823 mm = get_task_mm(task); 824 if (!mm) 825 goto out_free; 826 827 ret = -EIO; 828 829 if (file->private_data != (void*)((long)current->self_exec_id)) 830 goto out_put; 831 832 ret = 0; 833 834 while (count > 0) { 835 int this_len, retval; 836 837 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 838 retval = access_process_vm(task, src, page, this_len, 0); 839 if (!retval || check_mem_permission(task)) { 840 if (!ret) 841 ret = -EIO; 842 break; 843 } 844 845 if (copy_to_user(buf, page, retval)) { 846 ret = -EFAULT; 847 break; 848 } 849 850 ret += retval; 851 src += retval; 852 buf += retval; 853 count -= retval; 854 } 855 *ppos = src; 856 857 out_put: 858 mmput(mm); 859 out_free: 860 free_page((unsigned long) page); 861 out: 862 put_task_struct(task); 863 out_no_task: 864 return ret; 865 } 866 867 #define mem_write NULL 868 869 #ifndef mem_write 870 /* This is a security hazard */ 871 static ssize_t mem_write(struct file * file, const char __user *buf, 872 size_t count, loff_t *ppos) 873 { 874 int copied; 875 char *page; 876 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 877 unsigned long dst = *ppos; 878 879 copied = -ESRCH; 880 if (!task) 881 goto out_no_task; 882 883 if (check_mem_permission(task)) 884 goto out; 885 886 copied = -ENOMEM; 887 page = (char *)__get_free_page(GFP_TEMPORARY); 888 if (!page) 889 goto out; 890 891 copied = 0; 892 while (count > 0) { 893 int this_len, retval; 894 895 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 896 if (copy_from_user(page, buf, this_len)) { 897 copied = -EFAULT; 898 break; 899 } 900 retval = access_process_vm(task, dst, page, this_len, 1); 901 if (!retval) { 902 if (!copied) 903 copied = -EIO; 904 break; 905 } 906 copied += retval; 907 buf += retval; 908 dst += retval; 909 count -= retval; 910 } 911 *ppos = dst; 912 free_page((unsigned long) page); 913 out: 914 put_task_struct(task); 915 out_no_task: 916 return copied; 917 } 918 #endif 919 920 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 921 { 922 switch (orig) { 923 case 0: 924 file->f_pos = offset; 925 break; 926 case 1: 927 file->f_pos += offset; 928 break; 929 default: 930 return -EINVAL; 931 } 932 force_successful_syscall_return(); 933 return file->f_pos; 934 } 935 936 static const struct file_operations proc_mem_operations = { 937 .llseek = mem_lseek, 938 .read = mem_read, 939 .write = mem_write, 940 .open = mem_open, 941 }; 942 943 static ssize_t environ_read(struct file *file, char __user *buf, 944 size_t count, loff_t *ppos) 945 { 946 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 947 char *page; 948 unsigned long src = *ppos; 949 int ret = -ESRCH; 950 struct mm_struct *mm; 951 952 if (!task) 953 goto out_no_task; 954 955 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 956 goto out; 957 958 ret = -ENOMEM; 959 page = (char *)__get_free_page(GFP_TEMPORARY); 960 if (!page) 961 goto out; 962 963 ret = 0; 964 965 mm = get_task_mm(task); 966 if (!mm) 967 goto out_free; 968 969 while (count > 0) { 970 int this_len, retval, max_len; 971 972 this_len = mm->env_end - (mm->env_start + src); 973 974 if (this_len <= 0) 975 break; 976 977 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 978 this_len = (this_len > max_len) ? max_len : this_len; 979 980 retval = access_process_vm(task, (mm->env_start + src), 981 page, this_len, 0); 982 983 if (retval <= 0) { 984 ret = retval; 985 break; 986 } 987 988 if (copy_to_user(buf, page, retval)) { 989 ret = -EFAULT; 990 break; 991 } 992 993 ret += retval; 994 src += retval; 995 buf += retval; 996 count -= retval; 997 } 998 *ppos = src; 999 1000 mmput(mm); 1001 out_free: 1002 free_page((unsigned long) page); 1003 out: 1004 put_task_struct(task); 1005 out_no_task: 1006 return ret; 1007 } 1008 1009 static const struct file_operations proc_environ_operations = { 1010 .read = environ_read, 1011 }; 1012 1013 static ssize_t oom_adjust_read(struct file *file, char __user *buf, 1014 size_t count, loff_t *ppos) 1015 { 1016 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 1017 char buffer[PROC_NUMBUF]; 1018 size_t len; 1019 int oom_adjust; 1020 1021 if (!task) 1022 return -ESRCH; 1023 oom_adjust = task->oomkilladj; 1024 put_task_struct(task); 1025 1026 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); 1027 1028 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1029 } 1030 1031 static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 1032 size_t count, loff_t *ppos) 1033 { 1034 struct task_struct *task; 1035 char buffer[PROC_NUMBUF], *end; 1036 int oom_adjust; 1037 1038 memset(buffer, 0, sizeof(buffer)); 1039 if (count > sizeof(buffer) - 1) 1040 count = sizeof(buffer) - 1; 1041 if (copy_from_user(buffer, buf, count)) 1042 return -EFAULT; 1043 oom_adjust = simple_strtol(buffer, &end, 0); 1044 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && 1045 oom_adjust != OOM_DISABLE) 1046 return -EINVAL; 1047 if (*end == '\n') 1048 end++; 1049 task = get_proc_task(file->f_path.dentry->d_inode); 1050 if (!task) 1051 return -ESRCH; 1052 if (oom_adjust < task->oomkilladj && !capable(CAP_SYS_RESOURCE)) { 1053 put_task_struct(task); 1054 return -EACCES; 1055 } 1056 task->oomkilladj = oom_adjust; 1057 put_task_struct(task); 1058 if (end - buffer == 0) 1059 return -EIO; 1060 return end - buffer; 1061 } 1062 1063 static const struct file_operations proc_oom_adjust_operations = { 1064 .read = oom_adjust_read, 1065 .write = oom_adjust_write, 1066 }; 1067 1068 #ifdef CONFIG_AUDITSYSCALL 1069 #define TMPBUFLEN 21 1070 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1071 size_t count, loff_t *ppos) 1072 { 1073 struct inode * inode = file->f_path.dentry->d_inode; 1074 struct task_struct *task = get_proc_task(inode); 1075 ssize_t length; 1076 char tmpbuf[TMPBUFLEN]; 1077 1078 if (!task) 1079 return -ESRCH; 1080 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1081 audit_get_loginuid(task)); 1082 put_task_struct(task); 1083 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1084 } 1085 1086 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1087 size_t count, loff_t *ppos) 1088 { 1089 struct inode * inode = file->f_path.dentry->d_inode; 1090 char *page, *tmp; 1091 ssize_t length; 1092 uid_t loginuid; 1093 1094 if (!capable(CAP_AUDIT_CONTROL)) 1095 return -EPERM; 1096 1097 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) 1098 return -EPERM; 1099 1100 if (count >= PAGE_SIZE) 1101 count = PAGE_SIZE - 1; 1102 1103 if (*ppos != 0) { 1104 /* No partial writes. */ 1105 return -EINVAL; 1106 } 1107 page = (char*)__get_free_page(GFP_TEMPORARY); 1108 if (!page) 1109 return -ENOMEM; 1110 length = -EFAULT; 1111 if (copy_from_user(page, buf, count)) 1112 goto out_free_page; 1113 1114 page[count] = '\0'; 1115 loginuid = simple_strtoul(page, &tmp, 10); 1116 if (tmp == page) { 1117 length = -EINVAL; 1118 goto out_free_page; 1119 1120 } 1121 length = audit_set_loginuid(current, loginuid); 1122 if (likely(length == 0)) 1123 length = count; 1124 1125 out_free_page: 1126 free_page((unsigned long) page); 1127 return length; 1128 } 1129 1130 static const struct file_operations proc_loginuid_operations = { 1131 .read = proc_loginuid_read, 1132 .write = proc_loginuid_write, 1133 }; 1134 1135 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1136 size_t count, loff_t *ppos) 1137 { 1138 struct inode * inode = file->f_path.dentry->d_inode; 1139 struct task_struct *task = get_proc_task(inode); 1140 ssize_t length; 1141 char tmpbuf[TMPBUFLEN]; 1142 1143 if (!task) 1144 return -ESRCH; 1145 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1146 audit_get_sessionid(task)); 1147 put_task_struct(task); 1148 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1149 } 1150 1151 static const struct file_operations proc_sessionid_operations = { 1152 .read = proc_sessionid_read, 1153 }; 1154 #endif 1155 1156 #ifdef CONFIG_FAULT_INJECTION 1157 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1158 size_t count, loff_t *ppos) 1159 { 1160 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1161 char buffer[PROC_NUMBUF]; 1162 size_t len; 1163 int make_it_fail; 1164 1165 if (!task) 1166 return -ESRCH; 1167 make_it_fail = task->make_it_fail; 1168 put_task_struct(task); 1169 1170 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1171 1172 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1173 } 1174 1175 static ssize_t proc_fault_inject_write(struct file * file, 1176 const char __user * buf, size_t count, loff_t *ppos) 1177 { 1178 struct task_struct *task; 1179 char buffer[PROC_NUMBUF], *end; 1180 int make_it_fail; 1181 1182 if (!capable(CAP_SYS_RESOURCE)) 1183 return -EPERM; 1184 memset(buffer, 0, sizeof(buffer)); 1185 if (count > sizeof(buffer) - 1) 1186 count = sizeof(buffer) - 1; 1187 if (copy_from_user(buffer, buf, count)) 1188 return -EFAULT; 1189 make_it_fail = simple_strtol(buffer, &end, 0); 1190 if (*end == '\n') 1191 end++; 1192 task = get_proc_task(file->f_dentry->d_inode); 1193 if (!task) 1194 return -ESRCH; 1195 task->make_it_fail = make_it_fail; 1196 put_task_struct(task); 1197 if (end - buffer == 0) 1198 return -EIO; 1199 return end - buffer; 1200 } 1201 1202 static const struct file_operations proc_fault_inject_operations = { 1203 .read = proc_fault_inject_read, 1204 .write = proc_fault_inject_write, 1205 }; 1206 #endif 1207 1208 1209 #ifdef CONFIG_SCHED_DEBUG 1210 /* 1211 * Print out various scheduling related per-task fields: 1212 */ 1213 static int sched_show(struct seq_file *m, void *v) 1214 { 1215 struct inode *inode = m->private; 1216 struct task_struct *p; 1217 1218 p = get_proc_task(inode); 1219 if (!p) 1220 return -ESRCH; 1221 proc_sched_show_task(p, m); 1222 1223 put_task_struct(p); 1224 1225 return 0; 1226 } 1227 1228 static ssize_t 1229 sched_write(struct file *file, const char __user *buf, 1230 size_t count, loff_t *offset) 1231 { 1232 struct inode *inode = file->f_path.dentry->d_inode; 1233 struct task_struct *p; 1234 1235 p = get_proc_task(inode); 1236 if (!p) 1237 return -ESRCH; 1238 proc_sched_set_task(p); 1239 1240 put_task_struct(p); 1241 1242 return count; 1243 } 1244 1245 static int sched_open(struct inode *inode, struct file *filp) 1246 { 1247 int ret; 1248 1249 ret = single_open(filp, sched_show, NULL); 1250 if (!ret) { 1251 struct seq_file *m = filp->private_data; 1252 1253 m->private = inode; 1254 } 1255 return ret; 1256 } 1257 1258 static const struct file_operations proc_pid_sched_operations = { 1259 .open = sched_open, 1260 .read = seq_read, 1261 .write = sched_write, 1262 .llseek = seq_lseek, 1263 .release = single_release, 1264 }; 1265 1266 #endif 1267 1268 /* 1269 * We added or removed a vma mapping the executable. The vmas are only mapped 1270 * during exec and are not mapped with the mmap system call. 1271 * Callers must hold down_write() on the mm's mmap_sem for these 1272 */ 1273 void added_exe_file_vma(struct mm_struct *mm) 1274 { 1275 mm->num_exe_file_vmas++; 1276 } 1277 1278 void removed_exe_file_vma(struct mm_struct *mm) 1279 { 1280 mm->num_exe_file_vmas--; 1281 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){ 1282 fput(mm->exe_file); 1283 mm->exe_file = NULL; 1284 } 1285 1286 } 1287 1288 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) 1289 { 1290 if (new_exe_file) 1291 get_file(new_exe_file); 1292 if (mm->exe_file) 1293 fput(mm->exe_file); 1294 mm->exe_file = new_exe_file; 1295 mm->num_exe_file_vmas = 0; 1296 } 1297 1298 struct file *get_mm_exe_file(struct mm_struct *mm) 1299 { 1300 struct file *exe_file; 1301 1302 /* We need mmap_sem to protect against races with removal of 1303 * VM_EXECUTABLE vmas */ 1304 down_read(&mm->mmap_sem); 1305 exe_file = mm->exe_file; 1306 if (exe_file) 1307 get_file(exe_file); 1308 up_read(&mm->mmap_sem); 1309 return exe_file; 1310 } 1311 1312 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm) 1313 { 1314 /* It's safe to write the exe_file pointer without exe_file_lock because 1315 * this is called during fork when the task is not yet in /proc */ 1316 newmm->exe_file = get_mm_exe_file(oldmm); 1317 } 1318 1319 static int proc_exe_link(struct inode *inode, struct path *exe_path) 1320 { 1321 struct task_struct *task; 1322 struct mm_struct *mm; 1323 struct file *exe_file; 1324 1325 task = get_proc_task(inode); 1326 if (!task) 1327 return -ENOENT; 1328 mm = get_task_mm(task); 1329 put_task_struct(task); 1330 if (!mm) 1331 return -ENOENT; 1332 exe_file = get_mm_exe_file(mm); 1333 mmput(mm); 1334 if (exe_file) { 1335 *exe_path = exe_file->f_path; 1336 path_get(&exe_file->f_path); 1337 fput(exe_file); 1338 return 0; 1339 } else 1340 return -ENOENT; 1341 } 1342 1343 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1344 { 1345 struct inode *inode = dentry->d_inode; 1346 int error = -EACCES; 1347 1348 /* We don't need a base pointer in the /proc filesystem */ 1349 path_put(&nd->path); 1350 1351 /* Are we allowed to snoop on the tasks file descriptors? */ 1352 if (!proc_fd_access_allowed(inode)) 1353 goto out; 1354 1355 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path); 1356 nd->last_type = LAST_BIND; 1357 out: 1358 return ERR_PTR(error); 1359 } 1360 1361 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1362 { 1363 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1364 char *pathname; 1365 int len; 1366 1367 if (!tmp) 1368 return -ENOMEM; 1369 1370 pathname = d_path(path, tmp, PAGE_SIZE); 1371 len = PTR_ERR(pathname); 1372 if (IS_ERR(pathname)) 1373 goto out; 1374 len = tmp + PAGE_SIZE - 1 - pathname; 1375 1376 if (len > buflen) 1377 len = buflen; 1378 if (copy_to_user(buffer, pathname, len)) 1379 len = -EFAULT; 1380 out: 1381 free_page((unsigned long)tmp); 1382 return len; 1383 } 1384 1385 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1386 { 1387 int error = -EACCES; 1388 struct inode *inode = dentry->d_inode; 1389 struct path path; 1390 1391 /* Are we allowed to snoop on the tasks file descriptors? */ 1392 if (!proc_fd_access_allowed(inode)) 1393 goto out; 1394 1395 error = PROC_I(inode)->op.proc_get_link(inode, &path); 1396 if (error) 1397 goto out; 1398 1399 error = do_proc_readlink(&path, buffer, buflen); 1400 path_put(&path); 1401 out: 1402 return error; 1403 } 1404 1405 static const struct inode_operations proc_pid_link_inode_operations = { 1406 .readlink = proc_pid_readlink, 1407 .follow_link = proc_pid_follow_link, 1408 .setattr = proc_setattr, 1409 }; 1410 1411 1412 /* building an inode */ 1413 1414 static int task_dumpable(struct task_struct *task) 1415 { 1416 int dumpable = 0; 1417 struct mm_struct *mm; 1418 1419 task_lock(task); 1420 mm = task->mm; 1421 if (mm) 1422 dumpable = get_dumpable(mm); 1423 task_unlock(task); 1424 if(dumpable == 1) 1425 return 1; 1426 return 0; 1427 } 1428 1429 1430 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1431 { 1432 struct inode * inode; 1433 struct proc_inode *ei; 1434 const struct cred *cred; 1435 1436 /* We need a new inode */ 1437 1438 inode = new_inode(sb); 1439 if (!inode) 1440 goto out; 1441 1442 /* Common stuff */ 1443 ei = PROC_I(inode); 1444 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1445 inode->i_op = &proc_def_inode_operations; 1446 1447 /* 1448 * grab the reference to task. 1449 */ 1450 ei->pid = get_task_pid(task, PIDTYPE_PID); 1451 if (!ei->pid) 1452 goto out_unlock; 1453 1454 inode->i_uid = 0; 1455 inode->i_gid = 0; 1456 if (task_dumpable(task)) { 1457 rcu_read_lock(); 1458 cred = __task_cred(task); 1459 inode->i_uid = cred->euid; 1460 inode->i_gid = cred->egid; 1461 rcu_read_unlock(); 1462 } 1463 security_task_to_inode(task, inode); 1464 1465 out: 1466 return inode; 1467 1468 out_unlock: 1469 iput(inode); 1470 return NULL; 1471 } 1472 1473 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1474 { 1475 struct inode *inode = dentry->d_inode; 1476 struct task_struct *task; 1477 const struct cred *cred; 1478 1479 generic_fillattr(inode, stat); 1480 1481 rcu_read_lock(); 1482 stat->uid = 0; 1483 stat->gid = 0; 1484 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1485 if (task) { 1486 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1487 task_dumpable(task)) { 1488 cred = __task_cred(task); 1489 stat->uid = cred->euid; 1490 stat->gid = cred->egid; 1491 } 1492 } 1493 rcu_read_unlock(); 1494 return 0; 1495 } 1496 1497 /* dentry stuff */ 1498 1499 /* 1500 * Exceptional case: normally we are not allowed to unhash a busy 1501 * directory. In this case, however, we can do it - no aliasing problems 1502 * due to the way we treat inodes. 1503 * 1504 * Rewrite the inode's ownerships here because the owning task may have 1505 * performed a setuid(), etc. 1506 * 1507 * Before the /proc/pid/status file was created the only way to read 1508 * the effective uid of a /process was to stat /proc/pid. Reading 1509 * /proc/pid/status is slow enough that procps and other packages 1510 * kept stating /proc/pid. To keep the rules in /proc simple I have 1511 * made this apply to all per process world readable and executable 1512 * directories. 1513 */ 1514 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1515 { 1516 struct inode *inode = dentry->d_inode; 1517 struct task_struct *task = get_proc_task(inode); 1518 const struct cred *cred; 1519 1520 if (task) { 1521 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1522 task_dumpable(task)) { 1523 rcu_read_lock(); 1524 cred = __task_cred(task); 1525 inode->i_uid = cred->euid; 1526 inode->i_gid = cred->egid; 1527 rcu_read_unlock(); 1528 } else { 1529 inode->i_uid = 0; 1530 inode->i_gid = 0; 1531 } 1532 inode->i_mode &= ~(S_ISUID | S_ISGID); 1533 security_task_to_inode(task, inode); 1534 put_task_struct(task); 1535 return 1; 1536 } 1537 d_drop(dentry); 1538 return 0; 1539 } 1540 1541 static int pid_delete_dentry(struct dentry * dentry) 1542 { 1543 /* Is the task we represent dead? 1544 * If so, then don't put the dentry on the lru list, 1545 * kill it immediately. 1546 */ 1547 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1548 } 1549 1550 static struct dentry_operations pid_dentry_operations = 1551 { 1552 .d_revalidate = pid_revalidate, 1553 .d_delete = pid_delete_dentry, 1554 }; 1555 1556 /* Lookups */ 1557 1558 typedef struct dentry *instantiate_t(struct inode *, struct dentry *, 1559 struct task_struct *, const void *); 1560 1561 /* 1562 * Fill a directory entry. 1563 * 1564 * If possible create the dcache entry and derive our inode number and 1565 * file type from dcache entry. 1566 * 1567 * Since all of the proc inode numbers are dynamically generated, the inode 1568 * numbers do not exist until the inode is cache. This means creating the 1569 * the dcache entry in readdir is necessary to keep the inode numbers 1570 * reported by readdir in sync with the inode numbers reported 1571 * by stat. 1572 */ 1573 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1574 char *name, int len, 1575 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1576 { 1577 struct dentry *child, *dir = filp->f_path.dentry; 1578 struct inode *inode; 1579 struct qstr qname; 1580 ino_t ino = 0; 1581 unsigned type = DT_UNKNOWN; 1582 1583 qname.name = name; 1584 qname.len = len; 1585 qname.hash = full_name_hash(name, len); 1586 1587 child = d_lookup(dir, &qname); 1588 if (!child) { 1589 struct dentry *new; 1590 new = d_alloc(dir, &qname); 1591 if (new) { 1592 child = instantiate(dir->d_inode, new, task, ptr); 1593 if (child) 1594 dput(new); 1595 else 1596 child = new; 1597 } 1598 } 1599 if (!child || IS_ERR(child) || !child->d_inode) 1600 goto end_instantiate; 1601 inode = child->d_inode; 1602 if (inode) { 1603 ino = inode->i_ino; 1604 type = inode->i_mode >> 12; 1605 } 1606 dput(child); 1607 end_instantiate: 1608 if (!ino) 1609 ino = find_inode_number(dir, &qname); 1610 if (!ino) 1611 ino = 1; 1612 return filldir(dirent, name, len, filp->f_pos, ino, type); 1613 } 1614 1615 static unsigned name_to_int(struct dentry *dentry) 1616 { 1617 const char *name = dentry->d_name.name; 1618 int len = dentry->d_name.len; 1619 unsigned n = 0; 1620 1621 if (len > 1 && *name == '0') 1622 goto out; 1623 while (len-- > 0) { 1624 unsigned c = *name++ - '0'; 1625 if (c > 9) 1626 goto out; 1627 if (n >= (~0U-9)/10) 1628 goto out; 1629 n *= 10; 1630 n += c; 1631 } 1632 return n; 1633 out: 1634 return ~0U; 1635 } 1636 1637 #define PROC_FDINFO_MAX 64 1638 1639 static int proc_fd_info(struct inode *inode, struct path *path, char *info) 1640 { 1641 struct task_struct *task = get_proc_task(inode); 1642 struct files_struct *files = NULL; 1643 struct file *file; 1644 int fd = proc_fd(inode); 1645 1646 if (task) { 1647 files = get_files_struct(task); 1648 put_task_struct(task); 1649 } 1650 if (files) { 1651 /* 1652 * We are not taking a ref to the file structure, so we must 1653 * hold ->file_lock. 1654 */ 1655 spin_lock(&files->file_lock); 1656 file = fcheck_files(files, fd); 1657 if (file) { 1658 if (path) { 1659 *path = file->f_path; 1660 path_get(&file->f_path); 1661 } 1662 if (info) 1663 snprintf(info, PROC_FDINFO_MAX, 1664 "pos:\t%lli\n" 1665 "flags:\t0%o\n", 1666 (long long) file->f_pos, 1667 file->f_flags); 1668 spin_unlock(&files->file_lock); 1669 put_files_struct(files); 1670 return 0; 1671 } 1672 spin_unlock(&files->file_lock); 1673 put_files_struct(files); 1674 } 1675 return -ENOENT; 1676 } 1677 1678 static int proc_fd_link(struct inode *inode, struct path *path) 1679 { 1680 return proc_fd_info(inode, path, NULL); 1681 } 1682 1683 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1684 { 1685 struct inode *inode = dentry->d_inode; 1686 struct task_struct *task = get_proc_task(inode); 1687 int fd = proc_fd(inode); 1688 struct files_struct *files; 1689 const struct cred *cred; 1690 1691 if (task) { 1692 files = get_files_struct(task); 1693 if (files) { 1694 rcu_read_lock(); 1695 if (fcheck_files(files, fd)) { 1696 rcu_read_unlock(); 1697 put_files_struct(files); 1698 if (task_dumpable(task)) { 1699 rcu_read_lock(); 1700 cred = __task_cred(task); 1701 inode->i_uid = cred->euid; 1702 inode->i_gid = cred->egid; 1703 rcu_read_unlock(); 1704 } else { 1705 inode->i_uid = 0; 1706 inode->i_gid = 0; 1707 } 1708 inode->i_mode &= ~(S_ISUID | S_ISGID); 1709 security_task_to_inode(task, inode); 1710 put_task_struct(task); 1711 return 1; 1712 } 1713 rcu_read_unlock(); 1714 put_files_struct(files); 1715 } 1716 put_task_struct(task); 1717 } 1718 d_drop(dentry); 1719 return 0; 1720 } 1721 1722 static struct dentry_operations tid_fd_dentry_operations = 1723 { 1724 .d_revalidate = tid_fd_revalidate, 1725 .d_delete = pid_delete_dentry, 1726 }; 1727 1728 static struct dentry *proc_fd_instantiate(struct inode *dir, 1729 struct dentry *dentry, struct task_struct *task, const void *ptr) 1730 { 1731 unsigned fd = *(const unsigned *)ptr; 1732 struct file *file; 1733 struct files_struct *files; 1734 struct inode *inode; 1735 struct proc_inode *ei; 1736 struct dentry *error = ERR_PTR(-ENOENT); 1737 1738 inode = proc_pid_make_inode(dir->i_sb, task); 1739 if (!inode) 1740 goto out; 1741 ei = PROC_I(inode); 1742 ei->fd = fd; 1743 files = get_files_struct(task); 1744 if (!files) 1745 goto out_iput; 1746 inode->i_mode = S_IFLNK; 1747 1748 /* 1749 * We are not taking a ref to the file structure, so we must 1750 * hold ->file_lock. 1751 */ 1752 spin_lock(&files->file_lock); 1753 file = fcheck_files(files, fd); 1754 if (!file) 1755 goto out_unlock; 1756 if (file->f_mode & FMODE_READ) 1757 inode->i_mode |= S_IRUSR | S_IXUSR; 1758 if (file->f_mode & FMODE_WRITE) 1759 inode->i_mode |= S_IWUSR | S_IXUSR; 1760 spin_unlock(&files->file_lock); 1761 put_files_struct(files); 1762 1763 inode->i_op = &proc_pid_link_inode_operations; 1764 inode->i_size = 64; 1765 ei->op.proc_get_link = proc_fd_link; 1766 dentry->d_op = &tid_fd_dentry_operations; 1767 d_add(dentry, inode); 1768 /* Close the race of the process dying before we return the dentry */ 1769 if (tid_fd_revalidate(dentry, NULL)) 1770 error = NULL; 1771 1772 out: 1773 return error; 1774 out_unlock: 1775 spin_unlock(&files->file_lock); 1776 put_files_struct(files); 1777 out_iput: 1778 iput(inode); 1779 goto out; 1780 } 1781 1782 static struct dentry *proc_lookupfd_common(struct inode *dir, 1783 struct dentry *dentry, 1784 instantiate_t instantiate) 1785 { 1786 struct task_struct *task = get_proc_task(dir); 1787 unsigned fd = name_to_int(dentry); 1788 struct dentry *result = ERR_PTR(-ENOENT); 1789 1790 if (!task) 1791 goto out_no_task; 1792 if (fd == ~0U) 1793 goto out; 1794 1795 result = instantiate(dir, dentry, task, &fd); 1796 out: 1797 put_task_struct(task); 1798 out_no_task: 1799 return result; 1800 } 1801 1802 static int proc_readfd_common(struct file * filp, void * dirent, 1803 filldir_t filldir, instantiate_t instantiate) 1804 { 1805 struct dentry *dentry = filp->f_path.dentry; 1806 struct inode *inode = dentry->d_inode; 1807 struct task_struct *p = get_proc_task(inode); 1808 unsigned int fd, ino; 1809 int retval; 1810 struct files_struct * files; 1811 1812 retval = -ENOENT; 1813 if (!p) 1814 goto out_no_task; 1815 retval = 0; 1816 1817 fd = filp->f_pos; 1818 switch (fd) { 1819 case 0: 1820 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 1821 goto out; 1822 filp->f_pos++; 1823 case 1: 1824 ino = parent_ino(dentry); 1825 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 1826 goto out; 1827 filp->f_pos++; 1828 default: 1829 files = get_files_struct(p); 1830 if (!files) 1831 goto out; 1832 rcu_read_lock(); 1833 for (fd = filp->f_pos-2; 1834 fd < files_fdtable(files)->max_fds; 1835 fd++, filp->f_pos++) { 1836 char name[PROC_NUMBUF]; 1837 int len; 1838 1839 if (!fcheck_files(files, fd)) 1840 continue; 1841 rcu_read_unlock(); 1842 1843 len = snprintf(name, sizeof(name), "%d", fd); 1844 if (proc_fill_cache(filp, dirent, filldir, 1845 name, len, instantiate, 1846 p, &fd) < 0) { 1847 rcu_read_lock(); 1848 break; 1849 } 1850 rcu_read_lock(); 1851 } 1852 rcu_read_unlock(); 1853 put_files_struct(files); 1854 } 1855 out: 1856 put_task_struct(p); 1857 out_no_task: 1858 return retval; 1859 } 1860 1861 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 1862 struct nameidata *nd) 1863 { 1864 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 1865 } 1866 1867 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 1868 { 1869 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 1870 } 1871 1872 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 1873 size_t len, loff_t *ppos) 1874 { 1875 char tmp[PROC_FDINFO_MAX]; 1876 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); 1877 if (!err) 1878 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 1879 return err; 1880 } 1881 1882 static const struct file_operations proc_fdinfo_file_operations = { 1883 .open = nonseekable_open, 1884 .read = proc_fdinfo_read, 1885 }; 1886 1887 static const struct file_operations proc_fd_operations = { 1888 .read = generic_read_dir, 1889 .readdir = proc_readfd, 1890 }; 1891 1892 /* 1893 * /proc/pid/fd needs a special permission handler so that a process can still 1894 * access /proc/self/fd after it has executed a setuid(). 1895 */ 1896 static int proc_fd_permission(struct inode *inode, int mask) 1897 { 1898 int rv; 1899 1900 rv = generic_permission(inode, mask, NULL); 1901 if (rv == 0) 1902 return 0; 1903 if (task_pid(current) == proc_pid(inode)) 1904 rv = 0; 1905 return rv; 1906 } 1907 1908 /* 1909 * proc directories can do almost nothing.. 1910 */ 1911 static const struct inode_operations proc_fd_inode_operations = { 1912 .lookup = proc_lookupfd, 1913 .permission = proc_fd_permission, 1914 .setattr = proc_setattr, 1915 }; 1916 1917 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 1918 struct dentry *dentry, struct task_struct *task, const void *ptr) 1919 { 1920 unsigned fd = *(unsigned *)ptr; 1921 struct inode *inode; 1922 struct proc_inode *ei; 1923 struct dentry *error = ERR_PTR(-ENOENT); 1924 1925 inode = proc_pid_make_inode(dir->i_sb, task); 1926 if (!inode) 1927 goto out; 1928 ei = PROC_I(inode); 1929 ei->fd = fd; 1930 inode->i_mode = S_IFREG | S_IRUSR; 1931 inode->i_fop = &proc_fdinfo_file_operations; 1932 dentry->d_op = &tid_fd_dentry_operations; 1933 d_add(dentry, inode); 1934 /* Close the race of the process dying before we return the dentry */ 1935 if (tid_fd_revalidate(dentry, NULL)) 1936 error = NULL; 1937 1938 out: 1939 return error; 1940 } 1941 1942 static struct dentry *proc_lookupfdinfo(struct inode *dir, 1943 struct dentry *dentry, 1944 struct nameidata *nd) 1945 { 1946 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 1947 } 1948 1949 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 1950 { 1951 return proc_readfd_common(filp, dirent, filldir, 1952 proc_fdinfo_instantiate); 1953 } 1954 1955 static const struct file_operations proc_fdinfo_operations = { 1956 .read = generic_read_dir, 1957 .readdir = proc_readfdinfo, 1958 }; 1959 1960 /* 1961 * proc directories can do almost nothing.. 1962 */ 1963 static const struct inode_operations proc_fdinfo_inode_operations = { 1964 .lookup = proc_lookupfdinfo, 1965 .setattr = proc_setattr, 1966 }; 1967 1968 1969 static struct dentry *proc_pident_instantiate(struct inode *dir, 1970 struct dentry *dentry, struct task_struct *task, const void *ptr) 1971 { 1972 const struct pid_entry *p = ptr; 1973 struct inode *inode; 1974 struct proc_inode *ei; 1975 struct dentry *error = ERR_PTR(-EINVAL); 1976 1977 inode = proc_pid_make_inode(dir->i_sb, task); 1978 if (!inode) 1979 goto out; 1980 1981 ei = PROC_I(inode); 1982 inode->i_mode = p->mode; 1983 if (S_ISDIR(inode->i_mode)) 1984 inode->i_nlink = 2; /* Use getattr to fix if necessary */ 1985 if (p->iop) 1986 inode->i_op = p->iop; 1987 if (p->fop) 1988 inode->i_fop = p->fop; 1989 ei->op = p->op; 1990 dentry->d_op = &pid_dentry_operations; 1991 d_add(dentry, inode); 1992 /* Close the race of the process dying before we return the dentry */ 1993 if (pid_revalidate(dentry, NULL)) 1994 error = NULL; 1995 out: 1996 return error; 1997 } 1998 1999 static struct dentry *proc_pident_lookup(struct inode *dir, 2000 struct dentry *dentry, 2001 const struct pid_entry *ents, 2002 unsigned int nents) 2003 { 2004 struct inode *inode; 2005 struct dentry *error; 2006 struct task_struct *task = get_proc_task(dir); 2007 const struct pid_entry *p, *last; 2008 2009 error = ERR_PTR(-ENOENT); 2010 inode = NULL; 2011 2012 if (!task) 2013 goto out_no_task; 2014 2015 /* 2016 * Yes, it does not scale. And it should not. Don't add 2017 * new entries into /proc/<tgid>/ without very good reasons. 2018 */ 2019 last = &ents[nents - 1]; 2020 for (p = ents; p <= last; p++) { 2021 if (p->len != dentry->d_name.len) 2022 continue; 2023 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2024 break; 2025 } 2026 if (p > last) 2027 goto out; 2028 2029 error = proc_pident_instantiate(dir, dentry, task, p); 2030 out: 2031 put_task_struct(task); 2032 out_no_task: 2033 return error; 2034 } 2035 2036 static int proc_pident_fill_cache(struct file *filp, void *dirent, 2037 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2038 { 2039 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2040 proc_pident_instantiate, task, p); 2041 } 2042 2043 static int proc_pident_readdir(struct file *filp, 2044 void *dirent, filldir_t filldir, 2045 const struct pid_entry *ents, unsigned int nents) 2046 { 2047 int i; 2048 struct dentry *dentry = filp->f_path.dentry; 2049 struct inode *inode = dentry->d_inode; 2050 struct task_struct *task = get_proc_task(inode); 2051 const struct pid_entry *p, *last; 2052 ino_t ino; 2053 int ret; 2054 2055 ret = -ENOENT; 2056 if (!task) 2057 goto out_no_task; 2058 2059 ret = 0; 2060 i = filp->f_pos; 2061 switch (i) { 2062 case 0: 2063 ino = inode->i_ino; 2064 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 2065 goto out; 2066 i++; 2067 filp->f_pos++; 2068 /* fall through */ 2069 case 1: 2070 ino = parent_ino(dentry); 2071 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 2072 goto out; 2073 i++; 2074 filp->f_pos++; 2075 /* fall through */ 2076 default: 2077 i -= 2; 2078 if (i >= nents) { 2079 ret = 1; 2080 goto out; 2081 } 2082 p = ents + i; 2083 last = &ents[nents - 1]; 2084 while (p <= last) { 2085 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2086 goto out; 2087 filp->f_pos++; 2088 p++; 2089 } 2090 } 2091 2092 ret = 1; 2093 out: 2094 put_task_struct(task); 2095 out_no_task: 2096 return ret; 2097 } 2098 2099 #ifdef CONFIG_SECURITY 2100 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2101 size_t count, loff_t *ppos) 2102 { 2103 struct inode * inode = file->f_path.dentry->d_inode; 2104 char *p = NULL; 2105 ssize_t length; 2106 struct task_struct *task = get_proc_task(inode); 2107 2108 if (!task) 2109 return -ESRCH; 2110 2111 length = security_getprocattr(task, 2112 (char*)file->f_path.dentry->d_name.name, 2113 &p); 2114 put_task_struct(task); 2115 if (length > 0) 2116 length = simple_read_from_buffer(buf, count, ppos, p, length); 2117 kfree(p); 2118 return length; 2119 } 2120 2121 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2122 size_t count, loff_t *ppos) 2123 { 2124 struct inode * inode = file->f_path.dentry->d_inode; 2125 char *page; 2126 ssize_t length; 2127 struct task_struct *task = get_proc_task(inode); 2128 2129 length = -ESRCH; 2130 if (!task) 2131 goto out_no_task; 2132 if (count > PAGE_SIZE) 2133 count = PAGE_SIZE; 2134 2135 /* No partial writes. */ 2136 length = -EINVAL; 2137 if (*ppos != 0) 2138 goto out; 2139 2140 length = -ENOMEM; 2141 page = (char*)__get_free_page(GFP_TEMPORARY); 2142 if (!page) 2143 goto out; 2144 2145 length = -EFAULT; 2146 if (copy_from_user(page, buf, count)) 2147 goto out_free; 2148 2149 length = security_setprocattr(task, 2150 (char*)file->f_path.dentry->d_name.name, 2151 (void*)page, count); 2152 out_free: 2153 free_page((unsigned long) page); 2154 out: 2155 put_task_struct(task); 2156 out_no_task: 2157 return length; 2158 } 2159 2160 static const struct file_operations proc_pid_attr_operations = { 2161 .read = proc_pid_attr_read, 2162 .write = proc_pid_attr_write, 2163 }; 2164 2165 static const struct pid_entry attr_dir_stuff[] = { 2166 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2167 REG("prev", S_IRUGO, proc_pid_attr_operations), 2168 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2169 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2170 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2171 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2172 }; 2173 2174 static int proc_attr_dir_readdir(struct file * filp, 2175 void * dirent, filldir_t filldir) 2176 { 2177 return proc_pident_readdir(filp,dirent,filldir, 2178 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2179 } 2180 2181 static const struct file_operations proc_attr_dir_operations = { 2182 .read = generic_read_dir, 2183 .readdir = proc_attr_dir_readdir, 2184 }; 2185 2186 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2187 struct dentry *dentry, struct nameidata *nd) 2188 { 2189 return proc_pident_lookup(dir, dentry, 2190 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2191 } 2192 2193 static const struct inode_operations proc_attr_dir_inode_operations = { 2194 .lookup = proc_attr_dir_lookup, 2195 .getattr = pid_getattr, 2196 .setattr = proc_setattr, 2197 }; 2198 2199 #endif 2200 2201 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2202 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2203 size_t count, loff_t *ppos) 2204 { 2205 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2206 struct mm_struct *mm; 2207 char buffer[PROC_NUMBUF]; 2208 size_t len; 2209 int ret; 2210 2211 if (!task) 2212 return -ESRCH; 2213 2214 ret = 0; 2215 mm = get_task_mm(task); 2216 if (mm) { 2217 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2218 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2219 MMF_DUMP_FILTER_SHIFT)); 2220 mmput(mm); 2221 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2222 } 2223 2224 put_task_struct(task); 2225 2226 return ret; 2227 } 2228 2229 static ssize_t proc_coredump_filter_write(struct file *file, 2230 const char __user *buf, 2231 size_t count, 2232 loff_t *ppos) 2233 { 2234 struct task_struct *task; 2235 struct mm_struct *mm; 2236 char buffer[PROC_NUMBUF], *end; 2237 unsigned int val; 2238 int ret; 2239 int i; 2240 unsigned long mask; 2241 2242 ret = -EFAULT; 2243 memset(buffer, 0, sizeof(buffer)); 2244 if (count > sizeof(buffer) - 1) 2245 count = sizeof(buffer) - 1; 2246 if (copy_from_user(buffer, buf, count)) 2247 goto out_no_task; 2248 2249 ret = -EINVAL; 2250 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2251 if (*end == '\n') 2252 end++; 2253 if (end - buffer == 0) 2254 goto out_no_task; 2255 2256 ret = -ESRCH; 2257 task = get_proc_task(file->f_dentry->d_inode); 2258 if (!task) 2259 goto out_no_task; 2260 2261 ret = end - buffer; 2262 mm = get_task_mm(task); 2263 if (!mm) 2264 goto out_no_mm; 2265 2266 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2267 if (val & mask) 2268 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2269 else 2270 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2271 } 2272 2273 mmput(mm); 2274 out_no_mm: 2275 put_task_struct(task); 2276 out_no_task: 2277 return ret; 2278 } 2279 2280 static const struct file_operations proc_coredump_filter_operations = { 2281 .read = proc_coredump_filter_read, 2282 .write = proc_coredump_filter_write, 2283 }; 2284 #endif 2285 2286 /* 2287 * /proc/self: 2288 */ 2289 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2290 int buflen) 2291 { 2292 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2293 pid_t tgid = task_tgid_nr_ns(current, ns); 2294 char tmp[PROC_NUMBUF]; 2295 if (!tgid) 2296 return -ENOENT; 2297 sprintf(tmp, "%d", tgid); 2298 return vfs_readlink(dentry,buffer,buflen,tmp); 2299 } 2300 2301 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2302 { 2303 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2304 pid_t tgid = task_tgid_nr_ns(current, ns); 2305 char tmp[PROC_NUMBUF]; 2306 if (!tgid) 2307 return ERR_PTR(-ENOENT); 2308 sprintf(tmp, "%d", task_tgid_nr_ns(current, ns)); 2309 return ERR_PTR(vfs_follow_link(nd,tmp)); 2310 } 2311 2312 static const struct inode_operations proc_self_inode_operations = { 2313 .readlink = proc_self_readlink, 2314 .follow_link = proc_self_follow_link, 2315 }; 2316 2317 /* 2318 * proc base 2319 * 2320 * These are the directory entries in the root directory of /proc 2321 * that properly belong to the /proc filesystem, as they describe 2322 * describe something that is process related. 2323 */ 2324 static const struct pid_entry proc_base_stuff[] = { 2325 NOD("self", S_IFLNK|S_IRWXUGO, 2326 &proc_self_inode_operations, NULL, {}), 2327 }; 2328 2329 /* 2330 * Exceptional case: normally we are not allowed to unhash a busy 2331 * directory. In this case, however, we can do it - no aliasing problems 2332 * due to the way we treat inodes. 2333 */ 2334 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) 2335 { 2336 struct inode *inode = dentry->d_inode; 2337 struct task_struct *task = get_proc_task(inode); 2338 if (task) { 2339 put_task_struct(task); 2340 return 1; 2341 } 2342 d_drop(dentry); 2343 return 0; 2344 } 2345 2346 static struct dentry_operations proc_base_dentry_operations = 2347 { 2348 .d_revalidate = proc_base_revalidate, 2349 .d_delete = pid_delete_dentry, 2350 }; 2351 2352 static struct dentry *proc_base_instantiate(struct inode *dir, 2353 struct dentry *dentry, struct task_struct *task, const void *ptr) 2354 { 2355 const struct pid_entry *p = ptr; 2356 struct inode *inode; 2357 struct proc_inode *ei; 2358 struct dentry *error = ERR_PTR(-EINVAL); 2359 2360 /* Allocate the inode */ 2361 error = ERR_PTR(-ENOMEM); 2362 inode = new_inode(dir->i_sb); 2363 if (!inode) 2364 goto out; 2365 2366 /* Initialize the inode */ 2367 ei = PROC_I(inode); 2368 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2369 2370 /* 2371 * grab the reference to the task. 2372 */ 2373 ei->pid = get_task_pid(task, PIDTYPE_PID); 2374 if (!ei->pid) 2375 goto out_iput; 2376 2377 inode->i_uid = 0; 2378 inode->i_gid = 0; 2379 inode->i_mode = p->mode; 2380 if (S_ISDIR(inode->i_mode)) 2381 inode->i_nlink = 2; 2382 if (S_ISLNK(inode->i_mode)) 2383 inode->i_size = 64; 2384 if (p->iop) 2385 inode->i_op = p->iop; 2386 if (p->fop) 2387 inode->i_fop = p->fop; 2388 ei->op = p->op; 2389 dentry->d_op = &proc_base_dentry_operations; 2390 d_add(dentry, inode); 2391 error = NULL; 2392 out: 2393 return error; 2394 out_iput: 2395 iput(inode); 2396 goto out; 2397 } 2398 2399 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2400 { 2401 struct dentry *error; 2402 struct task_struct *task = get_proc_task(dir); 2403 const struct pid_entry *p, *last; 2404 2405 error = ERR_PTR(-ENOENT); 2406 2407 if (!task) 2408 goto out_no_task; 2409 2410 /* Lookup the directory entry */ 2411 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2412 for (p = proc_base_stuff; p <= last; p++) { 2413 if (p->len != dentry->d_name.len) 2414 continue; 2415 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2416 break; 2417 } 2418 if (p > last) 2419 goto out; 2420 2421 error = proc_base_instantiate(dir, dentry, task, p); 2422 2423 out: 2424 put_task_struct(task); 2425 out_no_task: 2426 return error; 2427 } 2428 2429 static int proc_base_fill_cache(struct file *filp, void *dirent, 2430 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2431 { 2432 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2433 proc_base_instantiate, task, p); 2434 } 2435 2436 #ifdef CONFIG_TASK_IO_ACCOUNTING 2437 static int do_io_accounting(struct task_struct *task, char *buffer, int whole) 2438 { 2439 struct task_io_accounting acct = task->ioac; 2440 unsigned long flags; 2441 2442 if (whole && lock_task_sighand(task, &flags)) { 2443 struct task_struct *t = task; 2444 2445 task_io_accounting_add(&acct, &task->signal->ioac); 2446 while_each_thread(task, t) 2447 task_io_accounting_add(&acct, &t->ioac); 2448 2449 unlock_task_sighand(task, &flags); 2450 } 2451 return sprintf(buffer, 2452 "rchar: %llu\n" 2453 "wchar: %llu\n" 2454 "syscr: %llu\n" 2455 "syscw: %llu\n" 2456 "read_bytes: %llu\n" 2457 "write_bytes: %llu\n" 2458 "cancelled_write_bytes: %llu\n", 2459 (unsigned long long)acct.rchar, 2460 (unsigned long long)acct.wchar, 2461 (unsigned long long)acct.syscr, 2462 (unsigned long long)acct.syscw, 2463 (unsigned long long)acct.read_bytes, 2464 (unsigned long long)acct.write_bytes, 2465 (unsigned long long)acct.cancelled_write_bytes); 2466 } 2467 2468 static int proc_tid_io_accounting(struct task_struct *task, char *buffer) 2469 { 2470 return do_io_accounting(task, buffer, 0); 2471 } 2472 2473 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer) 2474 { 2475 return do_io_accounting(task, buffer, 1); 2476 } 2477 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2478 2479 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2480 struct pid *pid, struct task_struct *task) 2481 { 2482 seq_printf(m, "%08x\n", task->personality); 2483 return 0; 2484 } 2485 2486 /* 2487 * Thread groups 2488 */ 2489 static const struct file_operations proc_task_operations; 2490 static const struct inode_operations proc_task_inode_operations; 2491 2492 static const struct pid_entry tgid_base_stuff[] = { 2493 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2494 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2495 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2496 #ifdef CONFIG_NET 2497 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2498 #endif 2499 REG("environ", S_IRUSR, proc_environ_operations), 2500 INF("auxv", S_IRUSR, proc_pid_auxv), 2501 ONE("status", S_IRUGO, proc_pid_status), 2502 ONE("personality", S_IRUSR, proc_pid_personality), 2503 INF("limits", S_IRUSR, proc_pid_limits), 2504 #ifdef CONFIG_SCHED_DEBUG 2505 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2506 #endif 2507 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2508 INF("syscall", S_IRUSR, proc_pid_syscall), 2509 #endif 2510 INF("cmdline", S_IRUGO, proc_pid_cmdline), 2511 ONE("stat", S_IRUGO, proc_tgid_stat), 2512 ONE("statm", S_IRUGO, proc_pid_statm), 2513 REG("maps", S_IRUGO, proc_maps_operations), 2514 #ifdef CONFIG_NUMA 2515 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 2516 #endif 2517 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2518 LNK("cwd", proc_cwd_link), 2519 LNK("root", proc_root_link), 2520 LNK("exe", proc_exe_link), 2521 REG("mounts", S_IRUGO, proc_mounts_operations), 2522 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2523 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2524 #ifdef CONFIG_PROC_PAGE_MONITOR 2525 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2526 REG("smaps", S_IRUGO, proc_smaps_operations), 2527 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2528 #endif 2529 #ifdef CONFIG_SECURITY 2530 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2531 #endif 2532 #ifdef CONFIG_KALLSYMS 2533 INF("wchan", S_IRUGO, proc_pid_wchan), 2534 #endif 2535 #ifdef CONFIG_STACKTRACE 2536 ONE("stack", S_IRUSR, proc_pid_stack), 2537 #endif 2538 #ifdef CONFIG_SCHEDSTATS 2539 INF("schedstat", S_IRUGO, proc_pid_schedstat), 2540 #endif 2541 #ifdef CONFIG_LATENCYTOP 2542 REG("latency", S_IRUGO, proc_lstats_operations), 2543 #endif 2544 #ifdef CONFIG_PROC_PID_CPUSET 2545 REG("cpuset", S_IRUGO, proc_cpuset_operations), 2546 #endif 2547 #ifdef CONFIG_CGROUPS 2548 REG("cgroup", S_IRUGO, proc_cgroup_operations), 2549 #endif 2550 INF("oom_score", S_IRUGO, proc_oom_score), 2551 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 2552 #ifdef CONFIG_AUDITSYSCALL 2553 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2554 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2555 #endif 2556 #ifdef CONFIG_FAULT_INJECTION 2557 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2558 #endif 2559 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2560 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2561 #endif 2562 #ifdef CONFIG_TASK_IO_ACCOUNTING 2563 INF("io", S_IRUGO, proc_tgid_io_accounting), 2564 #endif 2565 }; 2566 2567 static int proc_tgid_base_readdir(struct file * filp, 2568 void * dirent, filldir_t filldir) 2569 { 2570 return proc_pident_readdir(filp,dirent,filldir, 2571 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2572 } 2573 2574 static const struct file_operations proc_tgid_base_operations = { 2575 .read = generic_read_dir, 2576 .readdir = proc_tgid_base_readdir, 2577 }; 2578 2579 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2580 return proc_pident_lookup(dir, dentry, 2581 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2582 } 2583 2584 static const struct inode_operations proc_tgid_base_inode_operations = { 2585 .lookup = proc_tgid_base_lookup, 2586 .getattr = pid_getattr, 2587 .setattr = proc_setattr, 2588 }; 2589 2590 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2591 { 2592 struct dentry *dentry, *leader, *dir; 2593 char buf[PROC_NUMBUF]; 2594 struct qstr name; 2595 2596 name.name = buf; 2597 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2598 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2599 if (dentry) { 2600 if (!(current->flags & PF_EXITING)) 2601 shrink_dcache_parent(dentry); 2602 d_drop(dentry); 2603 dput(dentry); 2604 } 2605 2606 if (tgid == 0) 2607 goto out; 2608 2609 name.name = buf; 2610 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2611 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2612 if (!leader) 2613 goto out; 2614 2615 name.name = "task"; 2616 name.len = strlen(name.name); 2617 dir = d_hash_and_lookup(leader, &name); 2618 if (!dir) 2619 goto out_put_leader; 2620 2621 name.name = buf; 2622 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2623 dentry = d_hash_and_lookup(dir, &name); 2624 if (dentry) { 2625 shrink_dcache_parent(dentry); 2626 d_drop(dentry); 2627 dput(dentry); 2628 } 2629 2630 dput(dir); 2631 out_put_leader: 2632 dput(leader); 2633 out: 2634 return; 2635 } 2636 2637 /** 2638 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2639 * @task: task that should be flushed. 2640 * 2641 * When flushing dentries from proc, one needs to flush them from global 2642 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2643 * in. This call is supposed to do all of this job. 2644 * 2645 * Looks in the dcache for 2646 * /proc/@pid 2647 * /proc/@tgid/task/@pid 2648 * if either directory is present flushes it and all of it'ts children 2649 * from the dcache. 2650 * 2651 * It is safe and reasonable to cache /proc entries for a task until 2652 * that task exits. After that they just clog up the dcache with 2653 * useless entries, possibly causing useful dcache entries to be 2654 * flushed instead. This routine is proved to flush those useless 2655 * dcache entries at process exit time. 2656 * 2657 * NOTE: This routine is just an optimization so it does not guarantee 2658 * that no dcache entries will exist at process exit time it 2659 * just makes it very unlikely that any will persist. 2660 */ 2661 2662 void proc_flush_task(struct task_struct *task) 2663 { 2664 int i; 2665 struct pid *pid, *tgid = NULL; 2666 struct upid *upid; 2667 2668 pid = task_pid(task); 2669 if (thread_group_leader(task)) 2670 tgid = task_tgid(task); 2671 2672 for (i = 0; i <= pid->level; i++) { 2673 upid = &pid->numbers[i]; 2674 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 2675 tgid ? tgid->numbers[i].nr : 0); 2676 } 2677 2678 upid = &pid->numbers[pid->level]; 2679 if (upid->nr == 1) 2680 pid_ns_release_proc(upid->ns); 2681 } 2682 2683 static struct dentry *proc_pid_instantiate(struct inode *dir, 2684 struct dentry * dentry, 2685 struct task_struct *task, const void *ptr) 2686 { 2687 struct dentry *error = ERR_PTR(-ENOENT); 2688 struct inode *inode; 2689 2690 inode = proc_pid_make_inode(dir->i_sb, task); 2691 if (!inode) 2692 goto out; 2693 2694 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2695 inode->i_op = &proc_tgid_base_inode_operations; 2696 inode->i_fop = &proc_tgid_base_operations; 2697 inode->i_flags|=S_IMMUTABLE; 2698 2699 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff, 2700 ARRAY_SIZE(tgid_base_stuff)); 2701 2702 dentry->d_op = &pid_dentry_operations; 2703 2704 d_add(dentry, inode); 2705 /* Close the race of the process dying before we return the dentry */ 2706 if (pid_revalidate(dentry, NULL)) 2707 error = NULL; 2708 out: 2709 return error; 2710 } 2711 2712 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2713 { 2714 struct dentry *result = ERR_PTR(-ENOENT); 2715 struct task_struct *task; 2716 unsigned tgid; 2717 struct pid_namespace *ns; 2718 2719 result = proc_base_lookup(dir, dentry); 2720 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 2721 goto out; 2722 2723 tgid = name_to_int(dentry); 2724 if (tgid == ~0U) 2725 goto out; 2726 2727 ns = dentry->d_sb->s_fs_info; 2728 rcu_read_lock(); 2729 task = find_task_by_pid_ns(tgid, ns); 2730 if (task) 2731 get_task_struct(task); 2732 rcu_read_unlock(); 2733 if (!task) 2734 goto out; 2735 2736 result = proc_pid_instantiate(dir, dentry, task, NULL); 2737 put_task_struct(task); 2738 out: 2739 return result; 2740 } 2741 2742 /* 2743 * Find the first task with tgid >= tgid 2744 * 2745 */ 2746 struct tgid_iter { 2747 unsigned int tgid; 2748 struct task_struct *task; 2749 }; 2750 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 2751 { 2752 struct pid *pid; 2753 2754 if (iter.task) 2755 put_task_struct(iter.task); 2756 rcu_read_lock(); 2757 retry: 2758 iter.task = NULL; 2759 pid = find_ge_pid(iter.tgid, ns); 2760 if (pid) { 2761 iter.tgid = pid_nr_ns(pid, ns); 2762 iter.task = pid_task(pid, PIDTYPE_PID); 2763 /* What we to know is if the pid we have find is the 2764 * pid of a thread_group_leader. Testing for task 2765 * being a thread_group_leader is the obvious thing 2766 * todo but there is a window when it fails, due to 2767 * the pid transfer logic in de_thread. 2768 * 2769 * So we perform the straight forward test of seeing 2770 * if the pid we have found is the pid of a thread 2771 * group leader, and don't worry if the task we have 2772 * found doesn't happen to be a thread group leader. 2773 * As we don't care in the case of readdir. 2774 */ 2775 if (!iter.task || !has_group_leader_pid(iter.task)) { 2776 iter.tgid += 1; 2777 goto retry; 2778 } 2779 get_task_struct(iter.task); 2780 } 2781 rcu_read_unlock(); 2782 return iter; 2783 } 2784 2785 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 2786 2787 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2788 struct tgid_iter iter) 2789 { 2790 char name[PROC_NUMBUF]; 2791 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 2792 return proc_fill_cache(filp, dirent, filldir, name, len, 2793 proc_pid_instantiate, iter.task, NULL); 2794 } 2795 2796 /* for the /proc/ directory itself, after non-process stuff has been done */ 2797 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 2798 { 2799 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; 2800 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode); 2801 struct tgid_iter iter; 2802 struct pid_namespace *ns; 2803 2804 if (!reaper) 2805 goto out_no_task; 2806 2807 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 2808 const struct pid_entry *p = &proc_base_stuff[nr]; 2809 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 2810 goto out; 2811 } 2812 2813 ns = filp->f_dentry->d_sb->s_fs_info; 2814 iter.task = NULL; 2815 iter.tgid = filp->f_pos - TGID_OFFSET; 2816 for (iter = next_tgid(ns, iter); 2817 iter.task; 2818 iter.tgid += 1, iter = next_tgid(ns, iter)) { 2819 filp->f_pos = iter.tgid + TGID_OFFSET; 2820 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) { 2821 put_task_struct(iter.task); 2822 goto out; 2823 } 2824 } 2825 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 2826 out: 2827 put_task_struct(reaper); 2828 out_no_task: 2829 return 0; 2830 } 2831 2832 /* 2833 * Tasks 2834 */ 2835 static const struct pid_entry tid_base_stuff[] = { 2836 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2837 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fd_operations), 2838 REG("environ", S_IRUSR, proc_environ_operations), 2839 INF("auxv", S_IRUSR, proc_pid_auxv), 2840 ONE("status", S_IRUGO, proc_pid_status), 2841 ONE("personality", S_IRUSR, proc_pid_personality), 2842 INF("limits", S_IRUSR, proc_pid_limits), 2843 #ifdef CONFIG_SCHED_DEBUG 2844 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2845 #endif 2846 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2847 INF("syscall", S_IRUSR, proc_pid_syscall), 2848 #endif 2849 INF("cmdline", S_IRUGO, proc_pid_cmdline), 2850 ONE("stat", S_IRUGO, proc_tid_stat), 2851 ONE("statm", S_IRUGO, proc_pid_statm), 2852 REG("maps", S_IRUGO, proc_maps_operations), 2853 #ifdef CONFIG_NUMA 2854 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 2855 #endif 2856 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2857 LNK("cwd", proc_cwd_link), 2858 LNK("root", proc_root_link), 2859 LNK("exe", proc_exe_link), 2860 REG("mounts", S_IRUGO, proc_mounts_operations), 2861 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2862 #ifdef CONFIG_PROC_PAGE_MONITOR 2863 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2864 REG("smaps", S_IRUGO, proc_smaps_operations), 2865 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2866 #endif 2867 #ifdef CONFIG_SECURITY 2868 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2869 #endif 2870 #ifdef CONFIG_KALLSYMS 2871 INF("wchan", S_IRUGO, proc_pid_wchan), 2872 #endif 2873 #ifdef CONFIG_STACKTRACE 2874 ONE("stack", S_IRUSR, proc_pid_stack), 2875 #endif 2876 #ifdef CONFIG_SCHEDSTATS 2877 INF("schedstat", S_IRUGO, proc_pid_schedstat), 2878 #endif 2879 #ifdef CONFIG_LATENCYTOP 2880 REG("latency", S_IRUGO, proc_lstats_operations), 2881 #endif 2882 #ifdef CONFIG_PROC_PID_CPUSET 2883 REG("cpuset", S_IRUGO, proc_cpuset_operations), 2884 #endif 2885 #ifdef CONFIG_CGROUPS 2886 REG("cgroup", S_IRUGO, proc_cgroup_operations), 2887 #endif 2888 INF("oom_score", S_IRUGO, proc_oom_score), 2889 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 2890 #ifdef CONFIG_AUDITSYSCALL 2891 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2892 REG("sessionid", S_IRUSR, proc_sessionid_operations), 2893 #endif 2894 #ifdef CONFIG_FAULT_INJECTION 2895 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2896 #endif 2897 #ifdef CONFIG_TASK_IO_ACCOUNTING 2898 INF("io", S_IRUGO, proc_tid_io_accounting), 2899 #endif 2900 }; 2901 2902 static int proc_tid_base_readdir(struct file * filp, 2903 void * dirent, filldir_t filldir) 2904 { 2905 return proc_pident_readdir(filp,dirent,filldir, 2906 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 2907 } 2908 2909 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2910 return proc_pident_lookup(dir, dentry, 2911 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 2912 } 2913 2914 static const struct file_operations proc_tid_base_operations = { 2915 .read = generic_read_dir, 2916 .readdir = proc_tid_base_readdir, 2917 }; 2918 2919 static const struct inode_operations proc_tid_base_inode_operations = { 2920 .lookup = proc_tid_base_lookup, 2921 .getattr = pid_getattr, 2922 .setattr = proc_setattr, 2923 }; 2924 2925 static struct dentry *proc_task_instantiate(struct inode *dir, 2926 struct dentry *dentry, struct task_struct *task, const void *ptr) 2927 { 2928 struct dentry *error = ERR_PTR(-ENOENT); 2929 struct inode *inode; 2930 inode = proc_pid_make_inode(dir->i_sb, task); 2931 2932 if (!inode) 2933 goto out; 2934 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2935 inode->i_op = &proc_tid_base_inode_operations; 2936 inode->i_fop = &proc_tid_base_operations; 2937 inode->i_flags|=S_IMMUTABLE; 2938 2939 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff, 2940 ARRAY_SIZE(tid_base_stuff)); 2941 2942 dentry->d_op = &pid_dentry_operations; 2943 2944 d_add(dentry, inode); 2945 /* Close the race of the process dying before we return the dentry */ 2946 if (pid_revalidate(dentry, NULL)) 2947 error = NULL; 2948 out: 2949 return error; 2950 } 2951 2952 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2953 { 2954 struct dentry *result = ERR_PTR(-ENOENT); 2955 struct task_struct *task; 2956 struct task_struct *leader = get_proc_task(dir); 2957 unsigned tid; 2958 struct pid_namespace *ns; 2959 2960 if (!leader) 2961 goto out_no_task; 2962 2963 tid = name_to_int(dentry); 2964 if (tid == ~0U) 2965 goto out; 2966 2967 ns = dentry->d_sb->s_fs_info; 2968 rcu_read_lock(); 2969 task = find_task_by_pid_ns(tid, ns); 2970 if (task) 2971 get_task_struct(task); 2972 rcu_read_unlock(); 2973 if (!task) 2974 goto out; 2975 if (!same_thread_group(leader, task)) 2976 goto out_drop_task; 2977 2978 result = proc_task_instantiate(dir, dentry, task, NULL); 2979 out_drop_task: 2980 put_task_struct(task); 2981 out: 2982 put_task_struct(leader); 2983 out_no_task: 2984 return result; 2985 } 2986 2987 /* 2988 * Find the first tid of a thread group to return to user space. 2989 * 2990 * Usually this is just the thread group leader, but if the users 2991 * buffer was too small or there was a seek into the middle of the 2992 * directory we have more work todo. 2993 * 2994 * In the case of a short read we start with find_task_by_pid. 2995 * 2996 * In the case of a seek we start with the leader and walk nr 2997 * threads past it. 2998 */ 2999 static struct task_struct *first_tid(struct task_struct *leader, 3000 int tid, int nr, struct pid_namespace *ns) 3001 { 3002 struct task_struct *pos; 3003 3004 rcu_read_lock(); 3005 /* Attempt to start with the pid of a thread */ 3006 if (tid && (nr > 0)) { 3007 pos = find_task_by_pid_ns(tid, ns); 3008 if (pos && (pos->group_leader == leader)) 3009 goto found; 3010 } 3011 3012 /* If nr exceeds the number of threads there is nothing todo */ 3013 pos = NULL; 3014 if (nr && nr >= get_nr_threads(leader)) 3015 goto out; 3016 3017 /* If we haven't found our starting place yet start 3018 * with the leader and walk nr threads forward. 3019 */ 3020 for (pos = leader; nr > 0; --nr) { 3021 pos = next_thread(pos); 3022 if (pos == leader) { 3023 pos = NULL; 3024 goto out; 3025 } 3026 } 3027 found: 3028 get_task_struct(pos); 3029 out: 3030 rcu_read_unlock(); 3031 return pos; 3032 } 3033 3034 /* 3035 * Find the next thread in the thread list. 3036 * Return NULL if there is an error or no next thread. 3037 * 3038 * The reference to the input task_struct is released. 3039 */ 3040 static struct task_struct *next_tid(struct task_struct *start) 3041 { 3042 struct task_struct *pos = NULL; 3043 rcu_read_lock(); 3044 if (pid_alive(start)) { 3045 pos = next_thread(start); 3046 if (thread_group_leader(pos)) 3047 pos = NULL; 3048 else 3049 get_task_struct(pos); 3050 } 3051 rcu_read_unlock(); 3052 put_task_struct(start); 3053 return pos; 3054 } 3055 3056 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3057 struct task_struct *task, int tid) 3058 { 3059 char name[PROC_NUMBUF]; 3060 int len = snprintf(name, sizeof(name), "%d", tid); 3061 return proc_fill_cache(filp, dirent, filldir, name, len, 3062 proc_task_instantiate, task, NULL); 3063 } 3064 3065 /* for the /proc/TGID/task/ directories */ 3066 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 3067 { 3068 struct dentry *dentry = filp->f_path.dentry; 3069 struct inode *inode = dentry->d_inode; 3070 struct task_struct *leader = NULL; 3071 struct task_struct *task; 3072 int retval = -ENOENT; 3073 ino_t ino; 3074 int tid; 3075 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */ 3076 struct pid_namespace *ns; 3077 3078 task = get_proc_task(inode); 3079 if (!task) 3080 goto out_no_task; 3081 rcu_read_lock(); 3082 if (pid_alive(task)) { 3083 leader = task->group_leader; 3084 get_task_struct(leader); 3085 } 3086 rcu_read_unlock(); 3087 put_task_struct(task); 3088 if (!leader) 3089 goto out_no_task; 3090 retval = 0; 3091 3092 switch (pos) { 3093 case 0: 3094 ino = inode->i_ino; 3095 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0) 3096 goto out; 3097 pos++; 3098 /* fall through */ 3099 case 1: 3100 ino = parent_ino(dentry); 3101 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0) 3102 goto out; 3103 pos++; 3104 /* fall through */ 3105 } 3106 3107 /* f_version caches the tgid value that the last readdir call couldn't 3108 * return. lseek aka telldir automagically resets f_version to 0. 3109 */ 3110 ns = filp->f_dentry->d_sb->s_fs_info; 3111 tid = (int)filp->f_version; 3112 filp->f_version = 0; 3113 for (task = first_tid(leader, tid, pos - 2, ns); 3114 task; 3115 task = next_tid(task), pos++) { 3116 tid = task_pid_nr_ns(task, ns); 3117 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 3118 /* returning this tgid failed, save it as the first 3119 * pid for the next readir call */ 3120 filp->f_version = (u64)tid; 3121 put_task_struct(task); 3122 break; 3123 } 3124 } 3125 out: 3126 filp->f_pos = pos; 3127 put_task_struct(leader); 3128 out_no_task: 3129 return retval; 3130 } 3131 3132 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3133 { 3134 struct inode *inode = dentry->d_inode; 3135 struct task_struct *p = get_proc_task(inode); 3136 generic_fillattr(inode, stat); 3137 3138 if (p) { 3139 stat->nlink += get_nr_threads(p); 3140 put_task_struct(p); 3141 } 3142 3143 return 0; 3144 } 3145 3146 static const struct inode_operations proc_task_inode_operations = { 3147 .lookup = proc_task_lookup, 3148 .getattr = proc_task_getattr, 3149 .setattr = proc_setattr, 3150 }; 3151 3152 static const struct file_operations proc_task_operations = { 3153 .read = generic_read_dir, 3154 .readdir = proc_task_readdir, 3155 }; 3156