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/swap.h> 67 #include <linux/rcupdate.h> 68 #include <linux/kallsyms.h> 69 #include <linux/stacktrace.h> 70 #include <linux/resource.h> 71 #include <linux/module.h> 72 #include <linux/mount.h> 73 #include <linux/security.h> 74 #include <linux/ptrace.h> 75 #include <linux/tracehook.h> 76 #include <linux/cgroup.h> 77 #include <linux/cpuset.h> 78 #include <linux/audit.h> 79 #include <linux/poll.h> 80 #include <linux/nsproxy.h> 81 #include <linux/oom.h> 82 #include <linux/elf.h> 83 #include <linux/pid_namespace.h> 84 #include <linux/fs_struct.h> 85 #include <linux/slab.h> 86 #include "internal.h" 87 88 /* NOTE: 89 * Implementing inode permission operations in /proc is almost 90 * certainly an error. Permission checks need to happen during 91 * each system call not at open time. The reason is that most of 92 * what we wish to check for permissions in /proc varies at runtime. 93 * 94 * The classic example of a problem is opening file descriptors 95 * in /proc for a task before it execs a suid executable. 96 */ 97 98 struct pid_entry { 99 char *name; 100 int len; 101 mode_t mode; 102 const struct inode_operations *iop; 103 const struct file_operations *fop; 104 union proc_op op; 105 }; 106 107 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 108 .name = (NAME), \ 109 .len = sizeof(NAME) - 1, \ 110 .mode = MODE, \ 111 .iop = IOP, \ 112 .fop = FOP, \ 113 .op = OP, \ 114 } 115 116 #define DIR(NAME, MODE, iops, fops) \ 117 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} ) 118 #define LNK(NAME, get_link) \ 119 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 120 &proc_pid_link_inode_operations, NULL, \ 121 { .proc_get_link = get_link } ) 122 #define REG(NAME, MODE, fops) \ 123 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {}) 124 #define INF(NAME, MODE, read) \ 125 NOD(NAME, (S_IFREG|(MODE)), \ 126 NULL, &proc_info_file_operations, \ 127 { .proc_read = read } ) 128 #define ONE(NAME, MODE, show) \ 129 NOD(NAME, (S_IFREG|(MODE)), \ 130 NULL, &proc_single_file_operations, \ 131 { .proc_show = show } ) 132 133 /* 134 * Count the number of hardlinks for the pid_entry table, excluding the . 135 * and .. links. 136 */ 137 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries, 138 unsigned int n) 139 { 140 unsigned int i; 141 unsigned int count; 142 143 count = 0; 144 for (i = 0; i < n; ++i) { 145 if (S_ISDIR(entries[i].mode)) 146 ++count; 147 } 148 149 return count; 150 } 151 152 static int get_task_root(struct task_struct *task, struct path *root) 153 { 154 int result = -ENOENT; 155 156 task_lock(task); 157 if (task->fs) { 158 get_fs_root(task->fs, root); 159 result = 0; 160 } 161 task_unlock(task); 162 return result; 163 } 164 165 static int proc_cwd_link(struct inode *inode, struct path *path) 166 { 167 struct task_struct *task = get_proc_task(inode); 168 int result = -ENOENT; 169 170 if (task) { 171 task_lock(task); 172 if (task->fs) { 173 get_fs_pwd(task->fs, path); 174 result = 0; 175 } 176 task_unlock(task); 177 put_task_struct(task); 178 } 179 return result; 180 } 181 182 static int proc_root_link(struct inode *inode, struct path *path) 183 { 184 struct task_struct *task = get_proc_task(inode); 185 int result = -ENOENT; 186 187 if (task) { 188 result = get_task_root(task, path); 189 put_task_struct(task); 190 } 191 return result; 192 } 193 194 /* 195 * Return zero if current may access user memory in @task, -error if not. 196 */ 197 static int check_mem_permission(struct task_struct *task) 198 { 199 /* 200 * A task can always look at itself, in case it chooses 201 * to use system calls instead of load instructions. 202 */ 203 if (task == current) 204 return 0; 205 206 /* 207 * If current is actively ptrace'ing, and would also be 208 * permitted to freshly attach with ptrace now, permit it. 209 */ 210 if (task_is_stopped_or_traced(task)) { 211 int match; 212 rcu_read_lock(); 213 match = (tracehook_tracer_task(task) == current); 214 rcu_read_unlock(); 215 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH)) 216 return 0; 217 } 218 219 /* 220 * Noone else is allowed. 221 */ 222 return -EPERM; 223 } 224 225 struct mm_struct *mm_for_maps(struct task_struct *task) 226 { 227 struct mm_struct *mm; 228 229 if (mutex_lock_killable(&task->signal->cred_guard_mutex)) 230 return NULL; 231 232 mm = get_task_mm(task); 233 if (mm && mm != current->mm && 234 !ptrace_may_access(task, PTRACE_MODE_READ)) { 235 mmput(mm); 236 mm = NULL; 237 } 238 mutex_unlock(&task->signal->cred_guard_mutex); 239 240 return mm; 241 } 242 243 static int proc_pid_cmdline(struct task_struct *task, char * buffer) 244 { 245 int res = 0; 246 unsigned int len; 247 struct mm_struct *mm = get_task_mm(task); 248 if (!mm) 249 goto out; 250 if (!mm->arg_end) 251 goto out_mm; /* Shh! No looking before we're done */ 252 253 len = mm->arg_end - mm->arg_start; 254 255 if (len > PAGE_SIZE) 256 len = PAGE_SIZE; 257 258 res = access_process_vm(task, mm->arg_start, buffer, len, 0); 259 260 // If the nul at the end of args has been overwritten, then 261 // assume application is using setproctitle(3). 262 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) { 263 len = strnlen(buffer, res); 264 if (len < res) { 265 res = len; 266 } else { 267 len = mm->env_end - mm->env_start; 268 if (len > PAGE_SIZE - res) 269 len = PAGE_SIZE - res; 270 res += access_process_vm(task, mm->env_start, buffer+res, len, 0); 271 res = strnlen(buffer, res); 272 } 273 } 274 out_mm: 275 mmput(mm); 276 out: 277 return res; 278 } 279 280 static int proc_pid_auxv(struct task_struct *task, char *buffer) 281 { 282 int res = 0; 283 struct mm_struct *mm = get_task_mm(task); 284 if (mm) { 285 unsigned int nwords = 0; 286 do { 287 nwords += 2; 288 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 289 res = nwords * sizeof(mm->saved_auxv[0]); 290 if (res > PAGE_SIZE) 291 res = PAGE_SIZE; 292 memcpy(buffer, mm->saved_auxv, res); 293 mmput(mm); 294 } 295 return res; 296 } 297 298 299 #ifdef CONFIG_KALLSYMS 300 /* 301 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 302 * Returns the resolved symbol. If that fails, simply return the address. 303 */ 304 static int proc_pid_wchan(struct task_struct *task, char *buffer) 305 { 306 unsigned long wchan; 307 char symname[KSYM_NAME_LEN]; 308 309 wchan = get_wchan(task); 310 311 if (lookup_symbol_name(wchan, symname) < 0) 312 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 313 return 0; 314 else 315 return sprintf(buffer, "%lu", wchan); 316 else 317 return sprintf(buffer, "%s", symname); 318 } 319 #endif /* CONFIG_KALLSYMS */ 320 321 #ifdef CONFIG_STACKTRACE 322 323 #define MAX_STACK_TRACE_DEPTH 64 324 325 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, 326 struct pid *pid, struct task_struct *task) 327 { 328 struct stack_trace trace; 329 unsigned long *entries; 330 int i; 331 332 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL); 333 if (!entries) 334 return -ENOMEM; 335 336 trace.nr_entries = 0; 337 trace.max_entries = MAX_STACK_TRACE_DEPTH; 338 trace.entries = entries; 339 trace.skip = 0; 340 save_stack_trace_tsk(task, &trace); 341 342 for (i = 0; i < trace.nr_entries; i++) { 343 seq_printf(m, "[<%p>] %pS\n", 344 (void *)entries[i], (void *)entries[i]); 345 } 346 kfree(entries); 347 348 return 0; 349 } 350 #endif 351 352 #ifdef CONFIG_SCHEDSTATS 353 /* 354 * Provides /proc/PID/schedstat 355 */ 356 static int proc_pid_schedstat(struct task_struct *task, char *buffer) 357 { 358 return sprintf(buffer, "%llu %llu %lu\n", 359 (unsigned long long)task->se.sum_exec_runtime, 360 (unsigned long long)task->sched_info.run_delay, 361 task->sched_info.pcount); 362 } 363 #endif 364 365 #ifdef CONFIG_LATENCYTOP 366 static int lstats_show_proc(struct seq_file *m, void *v) 367 { 368 int i; 369 struct inode *inode = m->private; 370 struct task_struct *task = get_proc_task(inode); 371 372 if (!task) 373 return -ESRCH; 374 seq_puts(m, "Latency Top version : v0.1\n"); 375 for (i = 0; i < 32; i++) { 376 if (task->latency_record[i].backtrace[0]) { 377 int q; 378 seq_printf(m, "%i %li %li ", 379 task->latency_record[i].count, 380 task->latency_record[i].time, 381 task->latency_record[i].max); 382 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 383 char sym[KSYM_SYMBOL_LEN]; 384 char *c; 385 if (!task->latency_record[i].backtrace[q]) 386 break; 387 if (task->latency_record[i].backtrace[q] == ULONG_MAX) 388 break; 389 sprint_symbol(sym, task->latency_record[i].backtrace[q]); 390 c = strchr(sym, '+'); 391 if (c) 392 *c = 0; 393 seq_printf(m, "%s ", sym); 394 } 395 seq_printf(m, "\n"); 396 } 397 398 } 399 put_task_struct(task); 400 return 0; 401 } 402 403 static int lstats_open(struct inode *inode, struct file *file) 404 { 405 return single_open(file, lstats_show_proc, inode); 406 } 407 408 static ssize_t lstats_write(struct file *file, const char __user *buf, 409 size_t count, loff_t *offs) 410 { 411 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 412 413 if (!task) 414 return -ESRCH; 415 clear_all_latency_tracing(task); 416 put_task_struct(task); 417 418 return count; 419 } 420 421 static const struct file_operations proc_lstats_operations = { 422 .open = lstats_open, 423 .read = seq_read, 424 .write = lstats_write, 425 .llseek = seq_lseek, 426 .release = single_release, 427 }; 428 429 #endif 430 431 static int proc_oom_score(struct task_struct *task, char *buffer) 432 { 433 unsigned long points = 0; 434 435 read_lock(&tasklist_lock); 436 if (pid_alive(task)) 437 points = oom_badness(task, NULL, NULL, 438 totalram_pages + total_swap_pages); 439 read_unlock(&tasklist_lock); 440 return sprintf(buffer, "%lu\n", points); 441 } 442 443 struct limit_names { 444 char *name; 445 char *unit; 446 }; 447 448 static const struct limit_names lnames[RLIM_NLIMITS] = { 449 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 450 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 451 [RLIMIT_DATA] = {"Max data size", "bytes"}, 452 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 453 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 454 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 455 [RLIMIT_NPROC] = {"Max processes", "processes"}, 456 [RLIMIT_NOFILE] = {"Max open files", "files"}, 457 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 458 [RLIMIT_AS] = {"Max address space", "bytes"}, 459 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 460 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 461 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 462 [RLIMIT_NICE] = {"Max nice priority", NULL}, 463 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 464 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 465 }; 466 467 /* Display limits for a process */ 468 static int proc_pid_limits(struct task_struct *task, char *buffer) 469 { 470 unsigned int i; 471 int count = 0; 472 unsigned long flags; 473 char *bufptr = buffer; 474 475 struct rlimit rlim[RLIM_NLIMITS]; 476 477 if (!lock_task_sighand(task, &flags)) 478 return 0; 479 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 480 unlock_task_sighand(task, &flags); 481 482 /* 483 * print the file header 484 */ 485 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n", 486 "Limit", "Soft Limit", "Hard Limit", "Units"); 487 488 for (i = 0; i < RLIM_NLIMITS; i++) { 489 if (rlim[i].rlim_cur == RLIM_INFINITY) 490 count += sprintf(&bufptr[count], "%-25s %-20s ", 491 lnames[i].name, "unlimited"); 492 else 493 count += sprintf(&bufptr[count], "%-25s %-20lu ", 494 lnames[i].name, rlim[i].rlim_cur); 495 496 if (rlim[i].rlim_max == RLIM_INFINITY) 497 count += sprintf(&bufptr[count], "%-20s ", "unlimited"); 498 else 499 count += sprintf(&bufptr[count], "%-20lu ", 500 rlim[i].rlim_max); 501 502 if (lnames[i].unit) 503 count += sprintf(&bufptr[count], "%-10s\n", 504 lnames[i].unit); 505 else 506 count += sprintf(&bufptr[count], "\n"); 507 } 508 509 return count; 510 } 511 512 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 513 static int proc_pid_syscall(struct task_struct *task, char *buffer) 514 { 515 long nr; 516 unsigned long args[6], sp, pc; 517 518 if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) 519 return sprintf(buffer, "running\n"); 520 521 if (nr < 0) 522 return sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc); 523 524 return sprintf(buffer, 525 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", 526 nr, 527 args[0], args[1], args[2], args[3], args[4], args[5], 528 sp, pc); 529 } 530 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 531 532 /************************************************************************/ 533 /* Here the fs part begins */ 534 /************************************************************************/ 535 536 /* permission checks */ 537 static int proc_fd_access_allowed(struct inode *inode) 538 { 539 struct task_struct *task; 540 int allowed = 0; 541 /* Allow access to a task's file descriptors if it is us or we 542 * may use ptrace attach to the process and find out that 543 * information. 544 */ 545 task = get_proc_task(inode); 546 if (task) { 547 allowed = ptrace_may_access(task, PTRACE_MODE_READ); 548 put_task_struct(task); 549 } 550 return allowed; 551 } 552 553 static int proc_setattr(struct dentry *dentry, struct iattr *attr) 554 { 555 int error; 556 struct inode *inode = dentry->d_inode; 557 558 if (attr->ia_valid & ATTR_MODE) 559 return -EPERM; 560 561 error = inode_change_ok(inode, attr); 562 if (error) 563 return error; 564 565 if ((attr->ia_valid & ATTR_SIZE) && 566 attr->ia_size != i_size_read(inode)) { 567 error = vmtruncate(inode, attr->ia_size); 568 if (error) 569 return error; 570 } 571 572 setattr_copy(inode, attr); 573 mark_inode_dirty(inode); 574 return 0; 575 } 576 577 static const struct inode_operations proc_def_inode_operations = { 578 .setattr = proc_setattr, 579 }; 580 581 static int mounts_open_common(struct inode *inode, struct file *file, 582 const struct seq_operations *op) 583 { 584 struct task_struct *task = get_proc_task(inode); 585 struct nsproxy *nsp; 586 struct mnt_namespace *ns = NULL; 587 struct path root; 588 struct proc_mounts *p; 589 int ret = -EINVAL; 590 591 if (task) { 592 rcu_read_lock(); 593 nsp = task_nsproxy(task); 594 if (nsp) { 595 ns = nsp->mnt_ns; 596 if (ns) 597 get_mnt_ns(ns); 598 } 599 rcu_read_unlock(); 600 if (ns && get_task_root(task, &root) == 0) 601 ret = 0; 602 put_task_struct(task); 603 } 604 605 if (!ns) 606 goto err; 607 if (ret) 608 goto err_put_ns; 609 610 ret = -ENOMEM; 611 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL); 612 if (!p) 613 goto err_put_path; 614 615 file->private_data = &p->m; 616 ret = seq_open(file, op); 617 if (ret) 618 goto err_free; 619 620 p->m.private = p; 621 p->ns = ns; 622 p->root = root; 623 p->event = ns->event; 624 625 return 0; 626 627 err_free: 628 kfree(p); 629 err_put_path: 630 path_put(&root); 631 err_put_ns: 632 put_mnt_ns(ns); 633 err: 634 return ret; 635 } 636 637 static int mounts_release(struct inode *inode, struct file *file) 638 { 639 struct proc_mounts *p = file->private_data; 640 path_put(&p->root); 641 put_mnt_ns(p->ns); 642 return seq_release(inode, file); 643 } 644 645 static unsigned mounts_poll(struct file *file, poll_table *wait) 646 { 647 struct proc_mounts *p = file->private_data; 648 unsigned res = POLLIN | POLLRDNORM; 649 650 poll_wait(file, &p->ns->poll, wait); 651 if (mnt_had_events(p)) 652 res |= POLLERR | POLLPRI; 653 654 return res; 655 } 656 657 static int mounts_open(struct inode *inode, struct file *file) 658 { 659 return mounts_open_common(inode, file, &mounts_op); 660 } 661 662 static const struct file_operations proc_mounts_operations = { 663 .open = mounts_open, 664 .read = seq_read, 665 .llseek = seq_lseek, 666 .release = mounts_release, 667 .poll = mounts_poll, 668 }; 669 670 static int mountinfo_open(struct inode *inode, struct file *file) 671 { 672 return mounts_open_common(inode, file, &mountinfo_op); 673 } 674 675 static const struct file_operations proc_mountinfo_operations = { 676 .open = mountinfo_open, 677 .read = seq_read, 678 .llseek = seq_lseek, 679 .release = mounts_release, 680 .poll = mounts_poll, 681 }; 682 683 static int mountstats_open(struct inode *inode, struct file *file) 684 { 685 return mounts_open_common(inode, file, &mountstats_op); 686 } 687 688 static const struct file_operations proc_mountstats_operations = { 689 .open = mountstats_open, 690 .read = seq_read, 691 .llseek = seq_lseek, 692 .release = mounts_release, 693 }; 694 695 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */ 696 697 static ssize_t proc_info_read(struct file * file, char __user * buf, 698 size_t count, loff_t *ppos) 699 { 700 struct inode * inode = file->f_path.dentry->d_inode; 701 unsigned long page; 702 ssize_t length; 703 struct task_struct *task = get_proc_task(inode); 704 705 length = -ESRCH; 706 if (!task) 707 goto out_no_task; 708 709 if (count > PROC_BLOCK_SIZE) 710 count = PROC_BLOCK_SIZE; 711 712 length = -ENOMEM; 713 if (!(page = __get_free_page(GFP_TEMPORARY))) 714 goto out; 715 716 length = PROC_I(inode)->op.proc_read(task, (char*)page); 717 718 if (length >= 0) 719 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length); 720 free_page(page); 721 out: 722 put_task_struct(task); 723 out_no_task: 724 return length; 725 } 726 727 static const struct file_operations proc_info_file_operations = { 728 .read = proc_info_read, 729 .llseek = generic_file_llseek, 730 }; 731 732 static int proc_single_show(struct seq_file *m, void *v) 733 { 734 struct inode *inode = m->private; 735 struct pid_namespace *ns; 736 struct pid *pid; 737 struct task_struct *task; 738 int ret; 739 740 ns = inode->i_sb->s_fs_info; 741 pid = proc_pid(inode); 742 task = get_pid_task(pid, PIDTYPE_PID); 743 if (!task) 744 return -ESRCH; 745 746 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 747 748 put_task_struct(task); 749 return ret; 750 } 751 752 static int proc_single_open(struct inode *inode, struct file *filp) 753 { 754 int ret; 755 ret = single_open(filp, proc_single_show, NULL); 756 if (!ret) { 757 struct seq_file *m = filp->private_data; 758 759 m->private = inode; 760 } 761 return ret; 762 } 763 764 static const struct file_operations proc_single_file_operations = { 765 .open = proc_single_open, 766 .read = seq_read, 767 .llseek = seq_lseek, 768 .release = single_release, 769 }; 770 771 static int mem_open(struct inode* inode, struct file* file) 772 { 773 file->private_data = (void*)((long)current->self_exec_id); 774 /* OK to pass negative loff_t, we can catch out-of-range */ 775 file->f_mode |= FMODE_UNSIGNED_OFFSET; 776 return 0; 777 } 778 779 static ssize_t mem_read(struct file * file, char __user * buf, 780 size_t count, loff_t *ppos) 781 { 782 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 783 char *page; 784 unsigned long src = *ppos; 785 int ret = -ESRCH; 786 struct mm_struct *mm; 787 788 if (!task) 789 goto out_no_task; 790 791 if (check_mem_permission(task)) 792 goto out; 793 794 ret = -ENOMEM; 795 page = (char *)__get_free_page(GFP_TEMPORARY); 796 if (!page) 797 goto out; 798 799 ret = 0; 800 801 mm = get_task_mm(task); 802 if (!mm) 803 goto out_free; 804 805 ret = -EIO; 806 807 if (file->private_data != (void*)((long)current->self_exec_id)) 808 goto out_put; 809 810 ret = 0; 811 812 while (count > 0) { 813 int this_len, retval; 814 815 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 816 retval = access_process_vm(task, src, page, this_len, 0); 817 if (!retval || check_mem_permission(task)) { 818 if (!ret) 819 ret = -EIO; 820 break; 821 } 822 823 if (copy_to_user(buf, page, retval)) { 824 ret = -EFAULT; 825 break; 826 } 827 828 ret += retval; 829 src += retval; 830 buf += retval; 831 count -= retval; 832 } 833 *ppos = src; 834 835 out_put: 836 mmput(mm); 837 out_free: 838 free_page((unsigned long) page); 839 out: 840 put_task_struct(task); 841 out_no_task: 842 return ret; 843 } 844 845 #define mem_write NULL 846 847 #ifndef mem_write 848 /* This is a security hazard */ 849 static ssize_t mem_write(struct file * file, const char __user *buf, 850 size_t count, loff_t *ppos) 851 { 852 int copied; 853 char *page; 854 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 855 unsigned long dst = *ppos; 856 857 copied = -ESRCH; 858 if (!task) 859 goto out_no_task; 860 861 if (check_mem_permission(task)) 862 goto out; 863 864 copied = -ENOMEM; 865 page = (char *)__get_free_page(GFP_TEMPORARY); 866 if (!page) 867 goto out; 868 869 copied = 0; 870 while (count > 0) { 871 int this_len, retval; 872 873 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 874 if (copy_from_user(page, buf, this_len)) { 875 copied = -EFAULT; 876 break; 877 } 878 retval = access_process_vm(task, dst, page, this_len, 1); 879 if (!retval) { 880 if (!copied) 881 copied = -EIO; 882 break; 883 } 884 copied += retval; 885 buf += retval; 886 dst += retval; 887 count -= retval; 888 } 889 *ppos = dst; 890 free_page((unsigned long) page); 891 out: 892 put_task_struct(task); 893 out_no_task: 894 return copied; 895 } 896 #endif 897 898 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 899 { 900 switch (orig) { 901 case 0: 902 file->f_pos = offset; 903 break; 904 case 1: 905 file->f_pos += offset; 906 break; 907 default: 908 return -EINVAL; 909 } 910 force_successful_syscall_return(); 911 return file->f_pos; 912 } 913 914 static const struct file_operations proc_mem_operations = { 915 .llseek = mem_lseek, 916 .read = mem_read, 917 .write = mem_write, 918 .open = mem_open, 919 }; 920 921 static ssize_t environ_read(struct file *file, char __user *buf, 922 size_t count, loff_t *ppos) 923 { 924 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 925 char *page; 926 unsigned long src = *ppos; 927 int ret = -ESRCH; 928 struct mm_struct *mm; 929 930 if (!task) 931 goto out_no_task; 932 933 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 934 goto out; 935 936 ret = -ENOMEM; 937 page = (char *)__get_free_page(GFP_TEMPORARY); 938 if (!page) 939 goto out; 940 941 ret = 0; 942 943 mm = get_task_mm(task); 944 if (!mm) 945 goto out_free; 946 947 while (count > 0) { 948 int this_len, retval, max_len; 949 950 this_len = mm->env_end - (mm->env_start + src); 951 952 if (this_len <= 0) 953 break; 954 955 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 956 this_len = (this_len > max_len) ? max_len : this_len; 957 958 retval = access_process_vm(task, (mm->env_start + src), 959 page, this_len, 0); 960 961 if (retval <= 0) { 962 ret = retval; 963 break; 964 } 965 966 if (copy_to_user(buf, page, retval)) { 967 ret = -EFAULT; 968 break; 969 } 970 971 ret += retval; 972 src += retval; 973 buf += retval; 974 count -= retval; 975 } 976 *ppos = src; 977 978 mmput(mm); 979 out_free: 980 free_page((unsigned long) page); 981 out: 982 put_task_struct(task); 983 out_no_task: 984 return ret; 985 } 986 987 static const struct file_operations proc_environ_operations = { 988 .read = environ_read, 989 .llseek = generic_file_llseek, 990 }; 991 992 static ssize_t oom_adjust_read(struct file *file, char __user *buf, 993 size_t count, loff_t *ppos) 994 { 995 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 996 char buffer[PROC_NUMBUF]; 997 size_t len; 998 int oom_adjust = OOM_DISABLE; 999 unsigned long flags; 1000 1001 if (!task) 1002 return -ESRCH; 1003 1004 if (lock_task_sighand(task, &flags)) { 1005 oom_adjust = task->signal->oom_adj; 1006 unlock_task_sighand(task, &flags); 1007 } 1008 1009 put_task_struct(task); 1010 1011 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); 1012 1013 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1014 } 1015 1016 static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 1017 size_t count, loff_t *ppos) 1018 { 1019 struct task_struct *task; 1020 char buffer[PROC_NUMBUF]; 1021 long oom_adjust; 1022 unsigned long flags; 1023 int err; 1024 1025 memset(buffer, 0, sizeof(buffer)); 1026 if (count > sizeof(buffer) - 1) 1027 count = sizeof(buffer) - 1; 1028 if (copy_from_user(buffer, buf, count)) { 1029 err = -EFAULT; 1030 goto out; 1031 } 1032 1033 err = strict_strtol(strstrip(buffer), 0, &oom_adjust); 1034 if (err) 1035 goto out; 1036 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && 1037 oom_adjust != OOM_DISABLE) { 1038 err = -EINVAL; 1039 goto out; 1040 } 1041 1042 task = get_proc_task(file->f_path.dentry->d_inode); 1043 if (!task) { 1044 err = -ESRCH; 1045 goto out; 1046 } 1047 1048 task_lock(task); 1049 if (!task->mm) { 1050 err = -EINVAL; 1051 goto err_task_lock; 1052 } 1053 1054 if (!lock_task_sighand(task, &flags)) { 1055 err = -ESRCH; 1056 goto err_task_lock; 1057 } 1058 1059 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) { 1060 err = -EACCES; 1061 goto err_sighand; 1062 } 1063 1064 if (oom_adjust != task->signal->oom_adj) { 1065 if (oom_adjust == OOM_DISABLE) 1066 atomic_inc(&task->mm->oom_disable_count); 1067 if (task->signal->oom_adj == OOM_DISABLE) 1068 atomic_dec(&task->mm->oom_disable_count); 1069 } 1070 1071 /* 1072 * Warn that /proc/pid/oom_adj is deprecated, see 1073 * Documentation/feature-removal-schedule.txt. 1074 */ 1075 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, " 1076 "please use /proc/%d/oom_score_adj instead.\n", 1077 current->comm, task_pid_nr(current), 1078 task_pid_nr(task), task_pid_nr(task)); 1079 task->signal->oom_adj = oom_adjust; 1080 /* 1081 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 1082 * value is always attainable. 1083 */ 1084 if (task->signal->oom_adj == OOM_ADJUST_MAX) 1085 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX; 1086 else 1087 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) / 1088 -OOM_DISABLE; 1089 err_sighand: 1090 unlock_task_sighand(task, &flags); 1091 err_task_lock: 1092 task_unlock(task); 1093 put_task_struct(task); 1094 out: 1095 return err < 0 ? err : count; 1096 } 1097 1098 static const struct file_operations proc_oom_adjust_operations = { 1099 .read = oom_adjust_read, 1100 .write = oom_adjust_write, 1101 .llseek = generic_file_llseek, 1102 }; 1103 1104 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 1105 size_t count, loff_t *ppos) 1106 { 1107 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 1108 char buffer[PROC_NUMBUF]; 1109 int oom_score_adj = OOM_SCORE_ADJ_MIN; 1110 unsigned long flags; 1111 size_t len; 1112 1113 if (!task) 1114 return -ESRCH; 1115 if (lock_task_sighand(task, &flags)) { 1116 oom_score_adj = task->signal->oom_score_adj; 1117 unlock_task_sighand(task, &flags); 1118 } 1119 put_task_struct(task); 1120 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj); 1121 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1122 } 1123 1124 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1125 size_t count, loff_t *ppos) 1126 { 1127 struct task_struct *task; 1128 char buffer[PROC_NUMBUF]; 1129 unsigned long flags; 1130 long oom_score_adj; 1131 int err; 1132 1133 memset(buffer, 0, sizeof(buffer)); 1134 if (count > sizeof(buffer) - 1) 1135 count = sizeof(buffer) - 1; 1136 if (copy_from_user(buffer, buf, count)) { 1137 err = -EFAULT; 1138 goto out; 1139 } 1140 1141 err = strict_strtol(strstrip(buffer), 0, &oom_score_adj); 1142 if (err) 1143 goto out; 1144 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1145 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1146 err = -EINVAL; 1147 goto out; 1148 } 1149 1150 task = get_proc_task(file->f_path.dentry->d_inode); 1151 if (!task) { 1152 err = -ESRCH; 1153 goto out; 1154 } 1155 1156 task_lock(task); 1157 if (!task->mm) { 1158 err = -EINVAL; 1159 goto err_task_lock; 1160 } 1161 1162 if (!lock_task_sighand(task, &flags)) { 1163 err = -ESRCH; 1164 goto err_task_lock; 1165 } 1166 1167 if (oom_score_adj < task->signal->oom_score_adj && 1168 !capable(CAP_SYS_RESOURCE)) { 1169 err = -EACCES; 1170 goto err_sighand; 1171 } 1172 1173 if (oom_score_adj != task->signal->oom_score_adj) { 1174 if (oom_score_adj == OOM_SCORE_ADJ_MIN) 1175 atomic_inc(&task->mm->oom_disable_count); 1176 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) 1177 atomic_dec(&task->mm->oom_disable_count); 1178 } 1179 task->signal->oom_score_adj = oom_score_adj; 1180 /* 1181 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is 1182 * always attainable. 1183 */ 1184 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) 1185 task->signal->oom_adj = OOM_DISABLE; 1186 else 1187 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) / 1188 OOM_SCORE_ADJ_MAX; 1189 err_sighand: 1190 unlock_task_sighand(task, &flags); 1191 err_task_lock: 1192 task_unlock(task); 1193 put_task_struct(task); 1194 out: 1195 return err < 0 ? err : count; 1196 } 1197 1198 static const struct file_operations proc_oom_score_adj_operations = { 1199 .read = oom_score_adj_read, 1200 .write = oom_score_adj_write, 1201 .llseek = default_llseek, 1202 }; 1203 1204 #ifdef CONFIG_AUDITSYSCALL 1205 #define TMPBUFLEN 21 1206 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1207 size_t count, loff_t *ppos) 1208 { 1209 struct inode * inode = file->f_path.dentry->d_inode; 1210 struct task_struct *task = get_proc_task(inode); 1211 ssize_t length; 1212 char tmpbuf[TMPBUFLEN]; 1213 1214 if (!task) 1215 return -ESRCH; 1216 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1217 audit_get_loginuid(task)); 1218 put_task_struct(task); 1219 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1220 } 1221 1222 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1223 size_t count, loff_t *ppos) 1224 { 1225 struct inode * inode = file->f_path.dentry->d_inode; 1226 char *page, *tmp; 1227 ssize_t length; 1228 uid_t loginuid; 1229 1230 if (!capable(CAP_AUDIT_CONTROL)) 1231 return -EPERM; 1232 1233 rcu_read_lock(); 1234 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1235 rcu_read_unlock(); 1236 return -EPERM; 1237 } 1238 rcu_read_unlock(); 1239 1240 if (count >= PAGE_SIZE) 1241 count = PAGE_SIZE - 1; 1242 1243 if (*ppos != 0) { 1244 /* No partial writes. */ 1245 return -EINVAL; 1246 } 1247 page = (char*)__get_free_page(GFP_TEMPORARY); 1248 if (!page) 1249 return -ENOMEM; 1250 length = -EFAULT; 1251 if (copy_from_user(page, buf, count)) 1252 goto out_free_page; 1253 1254 page[count] = '\0'; 1255 loginuid = simple_strtoul(page, &tmp, 10); 1256 if (tmp == page) { 1257 length = -EINVAL; 1258 goto out_free_page; 1259 1260 } 1261 length = audit_set_loginuid(current, loginuid); 1262 if (likely(length == 0)) 1263 length = count; 1264 1265 out_free_page: 1266 free_page((unsigned long) page); 1267 return length; 1268 } 1269 1270 static const struct file_operations proc_loginuid_operations = { 1271 .read = proc_loginuid_read, 1272 .write = proc_loginuid_write, 1273 .llseek = generic_file_llseek, 1274 }; 1275 1276 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1277 size_t count, loff_t *ppos) 1278 { 1279 struct inode * inode = file->f_path.dentry->d_inode; 1280 struct task_struct *task = get_proc_task(inode); 1281 ssize_t length; 1282 char tmpbuf[TMPBUFLEN]; 1283 1284 if (!task) 1285 return -ESRCH; 1286 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1287 audit_get_sessionid(task)); 1288 put_task_struct(task); 1289 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1290 } 1291 1292 static const struct file_operations proc_sessionid_operations = { 1293 .read = proc_sessionid_read, 1294 .llseek = generic_file_llseek, 1295 }; 1296 #endif 1297 1298 #ifdef CONFIG_FAULT_INJECTION 1299 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1300 size_t count, loff_t *ppos) 1301 { 1302 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1303 char buffer[PROC_NUMBUF]; 1304 size_t len; 1305 int make_it_fail; 1306 1307 if (!task) 1308 return -ESRCH; 1309 make_it_fail = task->make_it_fail; 1310 put_task_struct(task); 1311 1312 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1313 1314 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1315 } 1316 1317 static ssize_t proc_fault_inject_write(struct file * file, 1318 const char __user * buf, size_t count, loff_t *ppos) 1319 { 1320 struct task_struct *task; 1321 char buffer[PROC_NUMBUF], *end; 1322 int make_it_fail; 1323 1324 if (!capable(CAP_SYS_RESOURCE)) 1325 return -EPERM; 1326 memset(buffer, 0, sizeof(buffer)); 1327 if (count > sizeof(buffer) - 1) 1328 count = sizeof(buffer) - 1; 1329 if (copy_from_user(buffer, buf, count)) 1330 return -EFAULT; 1331 make_it_fail = simple_strtol(strstrip(buffer), &end, 0); 1332 if (*end) 1333 return -EINVAL; 1334 task = get_proc_task(file->f_dentry->d_inode); 1335 if (!task) 1336 return -ESRCH; 1337 task->make_it_fail = make_it_fail; 1338 put_task_struct(task); 1339 1340 return count; 1341 } 1342 1343 static const struct file_operations proc_fault_inject_operations = { 1344 .read = proc_fault_inject_read, 1345 .write = proc_fault_inject_write, 1346 .llseek = generic_file_llseek, 1347 }; 1348 #endif 1349 1350 1351 #ifdef CONFIG_SCHED_DEBUG 1352 /* 1353 * Print out various scheduling related per-task fields: 1354 */ 1355 static int sched_show(struct seq_file *m, void *v) 1356 { 1357 struct inode *inode = m->private; 1358 struct task_struct *p; 1359 1360 p = get_proc_task(inode); 1361 if (!p) 1362 return -ESRCH; 1363 proc_sched_show_task(p, m); 1364 1365 put_task_struct(p); 1366 1367 return 0; 1368 } 1369 1370 static ssize_t 1371 sched_write(struct file *file, const char __user *buf, 1372 size_t count, loff_t *offset) 1373 { 1374 struct inode *inode = file->f_path.dentry->d_inode; 1375 struct task_struct *p; 1376 1377 p = get_proc_task(inode); 1378 if (!p) 1379 return -ESRCH; 1380 proc_sched_set_task(p); 1381 1382 put_task_struct(p); 1383 1384 return count; 1385 } 1386 1387 static int sched_open(struct inode *inode, struct file *filp) 1388 { 1389 int ret; 1390 1391 ret = single_open(filp, sched_show, NULL); 1392 if (!ret) { 1393 struct seq_file *m = filp->private_data; 1394 1395 m->private = inode; 1396 } 1397 return ret; 1398 } 1399 1400 static const struct file_operations proc_pid_sched_operations = { 1401 .open = sched_open, 1402 .read = seq_read, 1403 .write = sched_write, 1404 .llseek = seq_lseek, 1405 .release = single_release, 1406 }; 1407 1408 #endif 1409 1410 #ifdef CONFIG_SCHED_AUTOGROUP 1411 /* 1412 * Print out autogroup related information: 1413 */ 1414 static int sched_autogroup_show(struct seq_file *m, void *v) 1415 { 1416 struct inode *inode = m->private; 1417 struct task_struct *p; 1418 1419 p = get_proc_task(inode); 1420 if (!p) 1421 return -ESRCH; 1422 proc_sched_autogroup_show_task(p, m); 1423 1424 put_task_struct(p); 1425 1426 return 0; 1427 } 1428 1429 static ssize_t 1430 sched_autogroup_write(struct file *file, const char __user *buf, 1431 size_t count, loff_t *offset) 1432 { 1433 struct inode *inode = file->f_path.dentry->d_inode; 1434 struct task_struct *p; 1435 char buffer[PROC_NUMBUF]; 1436 long nice; 1437 int err; 1438 1439 memset(buffer, 0, sizeof(buffer)); 1440 if (count > sizeof(buffer) - 1) 1441 count = sizeof(buffer) - 1; 1442 if (copy_from_user(buffer, buf, count)) 1443 return -EFAULT; 1444 1445 err = strict_strtol(strstrip(buffer), 0, &nice); 1446 if (err) 1447 return -EINVAL; 1448 1449 p = get_proc_task(inode); 1450 if (!p) 1451 return -ESRCH; 1452 1453 err = nice; 1454 err = proc_sched_autogroup_set_nice(p, &err); 1455 if (err) 1456 count = err; 1457 1458 put_task_struct(p); 1459 1460 return count; 1461 } 1462 1463 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1464 { 1465 int ret; 1466 1467 ret = single_open(filp, sched_autogroup_show, NULL); 1468 if (!ret) { 1469 struct seq_file *m = filp->private_data; 1470 1471 m->private = inode; 1472 } 1473 return ret; 1474 } 1475 1476 static const struct file_operations proc_pid_sched_autogroup_operations = { 1477 .open = sched_autogroup_open, 1478 .read = seq_read, 1479 .write = sched_autogroup_write, 1480 .llseek = seq_lseek, 1481 .release = single_release, 1482 }; 1483 1484 #endif /* CONFIG_SCHED_AUTOGROUP */ 1485 1486 static ssize_t comm_write(struct file *file, const char __user *buf, 1487 size_t count, loff_t *offset) 1488 { 1489 struct inode *inode = file->f_path.dentry->d_inode; 1490 struct task_struct *p; 1491 char buffer[TASK_COMM_LEN]; 1492 1493 memset(buffer, 0, sizeof(buffer)); 1494 if (count > sizeof(buffer) - 1) 1495 count = sizeof(buffer) - 1; 1496 if (copy_from_user(buffer, buf, count)) 1497 return -EFAULT; 1498 1499 p = get_proc_task(inode); 1500 if (!p) 1501 return -ESRCH; 1502 1503 if (same_thread_group(current, p)) 1504 set_task_comm(p, buffer); 1505 else 1506 count = -EINVAL; 1507 1508 put_task_struct(p); 1509 1510 return count; 1511 } 1512 1513 static int comm_show(struct seq_file *m, void *v) 1514 { 1515 struct inode *inode = m->private; 1516 struct task_struct *p; 1517 1518 p = get_proc_task(inode); 1519 if (!p) 1520 return -ESRCH; 1521 1522 task_lock(p); 1523 seq_printf(m, "%s\n", p->comm); 1524 task_unlock(p); 1525 1526 put_task_struct(p); 1527 1528 return 0; 1529 } 1530 1531 static int comm_open(struct inode *inode, struct file *filp) 1532 { 1533 int ret; 1534 1535 ret = single_open(filp, comm_show, NULL); 1536 if (!ret) { 1537 struct seq_file *m = filp->private_data; 1538 1539 m->private = inode; 1540 } 1541 return ret; 1542 } 1543 1544 static const struct file_operations proc_pid_set_comm_operations = { 1545 .open = comm_open, 1546 .read = seq_read, 1547 .write = comm_write, 1548 .llseek = seq_lseek, 1549 .release = single_release, 1550 }; 1551 1552 /* 1553 * We added or removed a vma mapping the executable. The vmas are only mapped 1554 * during exec and are not mapped with the mmap system call. 1555 * Callers must hold down_write() on the mm's mmap_sem for these 1556 */ 1557 void added_exe_file_vma(struct mm_struct *mm) 1558 { 1559 mm->num_exe_file_vmas++; 1560 } 1561 1562 void removed_exe_file_vma(struct mm_struct *mm) 1563 { 1564 mm->num_exe_file_vmas--; 1565 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){ 1566 fput(mm->exe_file); 1567 mm->exe_file = NULL; 1568 } 1569 1570 } 1571 1572 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) 1573 { 1574 if (new_exe_file) 1575 get_file(new_exe_file); 1576 if (mm->exe_file) 1577 fput(mm->exe_file); 1578 mm->exe_file = new_exe_file; 1579 mm->num_exe_file_vmas = 0; 1580 } 1581 1582 struct file *get_mm_exe_file(struct mm_struct *mm) 1583 { 1584 struct file *exe_file; 1585 1586 /* We need mmap_sem to protect against races with removal of 1587 * VM_EXECUTABLE vmas */ 1588 down_read(&mm->mmap_sem); 1589 exe_file = mm->exe_file; 1590 if (exe_file) 1591 get_file(exe_file); 1592 up_read(&mm->mmap_sem); 1593 return exe_file; 1594 } 1595 1596 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm) 1597 { 1598 /* It's safe to write the exe_file pointer without exe_file_lock because 1599 * this is called during fork when the task is not yet in /proc */ 1600 newmm->exe_file = get_mm_exe_file(oldmm); 1601 } 1602 1603 static int proc_exe_link(struct inode *inode, struct path *exe_path) 1604 { 1605 struct task_struct *task; 1606 struct mm_struct *mm; 1607 struct file *exe_file; 1608 1609 task = get_proc_task(inode); 1610 if (!task) 1611 return -ENOENT; 1612 mm = get_task_mm(task); 1613 put_task_struct(task); 1614 if (!mm) 1615 return -ENOENT; 1616 exe_file = get_mm_exe_file(mm); 1617 mmput(mm); 1618 if (exe_file) { 1619 *exe_path = exe_file->f_path; 1620 path_get(&exe_file->f_path); 1621 fput(exe_file); 1622 return 0; 1623 } else 1624 return -ENOENT; 1625 } 1626 1627 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1628 { 1629 struct inode *inode = dentry->d_inode; 1630 int error = -EACCES; 1631 1632 /* We don't need a base pointer in the /proc filesystem */ 1633 path_put(&nd->path); 1634 1635 /* Are we allowed to snoop on the tasks file descriptors? */ 1636 if (!proc_fd_access_allowed(inode)) 1637 goto out; 1638 1639 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path); 1640 out: 1641 return ERR_PTR(error); 1642 } 1643 1644 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1645 { 1646 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1647 char *pathname; 1648 int len; 1649 1650 if (!tmp) 1651 return -ENOMEM; 1652 1653 pathname = d_path(path, tmp, PAGE_SIZE); 1654 len = PTR_ERR(pathname); 1655 if (IS_ERR(pathname)) 1656 goto out; 1657 len = tmp + PAGE_SIZE - 1 - pathname; 1658 1659 if (len > buflen) 1660 len = buflen; 1661 if (copy_to_user(buffer, pathname, len)) 1662 len = -EFAULT; 1663 out: 1664 free_page((unsigned long)tmp); 1665 return len; 1666 } 1667 1668 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1669 { 1670 int error = -EACCES; 1671 struct inode *inode = dentry->d_inode; 1672 struct path path; 1673 1674 /* Are we allowed to snoop on the tasks file descriptors? */ 1675 if (!proc_fd_access_allowed(inode)) 1676 goto out; 1677 1678 error = PROC_I(inode)->op.proc_get_link(inode, &path); 1679 if (error) 1680 goto out; 1681 1682 error = do_proc_readlink(&path, buffer, buflen); 1683 path_put(&path); 1684 out: 1685 return error; 1686 } 1687 1688 static const struct inode_operations proc_pid_link_inode_operations = { 1689 .readlink = proc_pid_readlink, 1690 .follow_link = proc_pid_follow_link, 1691 .setattr = proc_setattr, 1692 }; 1693 1694 1695 /* building an inode */ 1696 1697 static int task_dumpable(struct task_struct *task) 1698 { 1699 int dumpable = 0; 1700 struct mm_struct *mm; 1701 1702 task_lock(task); 1703 mm = task->mm; 1704 if (mm) 1705 dumpable = get_dumpable(mm); 1706 task_unlock(task); 1707 if(dumpable == 1) 1708 return 1; 1709 return 0; 1710 } 1711 1712 1713 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1714 { 1715 struct inode * inode; 1716 struct proc_inode *ei; 1717 const struct cred *cred; 1718 1719 /* We need a new inode */ 1720 1721 inode = new_inode(sb); 1722 if (!inode) 1723 goto out; 1724 1725 /* Common stuff */ 1726 ei = PROC_I(inode); 1727 inode->i_ino = get_next_ino(); 1728 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1729 inode->i_op = &proc_def_inode_operations; 1730 1731 /* 1732 * grab the reference to task. 1733 */ 1734 ei->pid = get_task_pid(task, PIDTYPE_PID); 1735 if (!ei->pid) 1736 goto out_unlock; 1737 1738 if (task_dumpable(task)) { 1739 rcu_read_lock(); 1740 cred = __task_cred(task); 1741 inode->i_uid = cred->euid; 1742 inode->i_gid = cred->egid; 1743 rcu_read_unlock(); 1744 } 1745 security_task_to_inode(task, inode); 1746 1747 out: 1748 return inode; 1749 1750 out_unlock: 1751 iput(inode); 1752 return NULL; 1753 } 1754 1755 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1756 { 1757 struct inode *inode = dentry->d_inode; 1758 struct task_struct *task; 1759 const struct cred *cred; 1760 1761 generic_fillattr(inode, stat); 1762 1763 rcu_read_lock(); 1764 stat->uid = 0; 1765 stat->gid = 0; 1766 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1767 if (task) { 1768 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1769 task_dumpable(task)) { 1770 cred = __task_cred(task); 1771 stat->uid = cred->euid; 1772 stat->gid = cred->egid; 1773 } 1774 } 1775 rcu_read_unlock(); 1776 return 0; 1777 } 1778 1779 /* dentry stuff */ 1780 1781 /* 1782 * Exceptional case: normally we are not allowed to unhash a busy 1783 * directory. In this case, however, we can do it - no aliasing problems 1784 * due to the way we treat inodes. 1785 * 1786 * Rewrite the inode's ownerships here because the owning task may have 1787 * performed a setuid(), etc. 1788 * 1789 * Before the /proc/pid/status file was created the only way to read 1790 * the effective uid of a /process was to stat /proc/pid. Reading 1791 * /proc/pid/status is slow enough that procps and other packages 1792 * kept stating /proc/pid. To keep the rules in /proc simple I have 1793 * made this apply to all per process world readable and executable 1794 * directories. 1795 */ 1796 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1797 { 1798 struct inode *inode = dentry->d_inode; 1799 struct task_struct *task = get_proc_task(inode); 1800 const struct cred *cred; 1801 1802 if (task) { 1803 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1804 task_dumpable(task)) { 1805 rcu_read_lock(); 1806 cred = __task_cred(task); 1807 inode->i_uid = cred->euid; 1808 inode->i_gid = cred->egid; 1809 rcu_read_unlock(); 1810 } else { 1811 inode->i_uid = 0; 1812 inode->i_gid = 0; 1813 } 1814 inode->i_mode &= ~(S_ISUID | S_ISGID); 1815 security_task_to_inode(task, inode); 1816 put_task_struct(task); 1817 return 1; 1818 } 1819 d_drop(dentry); 1820 return 0; 1821 } 1822 1823 static int pid_delete_dentry(struct dentry * dentry) 1824 { 1825 /* Is the task we represent dead? 1826 * If so, then don't put the dentry on the lru list, 1827 * kill it immediately. 1828 */ 1829 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1830 } 1831 1832 static const struct dentry_operations pid_dentry_operations = 1833 { 1834 .d_revalidate = pid_revalidate, 1835 .d_delete = pid_delete_dentry, 1836 }; 1837 1838 /* Lookups */ 1839 1840 typedef struct dentry *instantiate_t(struct inode *, struct dentry *, 1841 struct task_struct *, const void *); 1842 1843 /* 1844 * Fill a directory entry. 1845 * 1846 * If possible create the dcache entry and derive our inode number and 1847 * file type from dcache entry. 1848 * 1849 * Since all of the proc inode numbers are dynamically generated, the inode 1850 * numbers do not exist until the inode is cache. This means creating the 1851 * the dcache entry in readdir is necessary to keep the inode numbers 1852 * reported by readdir in sync with the inode numbers reported 1853 * by stat. 1854 */ 1855 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1856 char *name, int len, 1857 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1858 { 1859 struct dentry *child, *dir = filp->f_path.dentry; 1860 struct inode *inode; 1861 struct qstr qname; 1862 ino_t ino = 0; 1863 unsigned type = DT_UNKNOWN; 1864 1865 qname.name = name; 1866 qname.len = len; 1867 qname.hash = full_name_hash(name, len); 1868 1869 child = d_lookup(dir, &qname); 1870 if (!child) { 1871 struct dentry *new; 1872 new = d_alloc(dir, &qname); 1873 if (new) { 1874 child = instantiate(dir->d_inode, new, task, ptr); 1875 if (child) 1876 dput(new); 1877 else 1878 child = new; 1879 } 1880 } 1881 if (!child || IS_ERR(child) || !child->d_inode) 1882 goto end_instantiate; 1883 inode = child->d_inode; 1884 if (inode) { 1885 ino = inode->i_ino; 1886 type = inode->i_mode >> 12; 1887 } 1888 dput(child); 1889 end_instantiate: 1890 if (!ino) 1891 ino = find_inode_number(dir, &qname); 1892 if (!ino) 1893 ino = 1; 1894 return filldir(dirent, name, len, filp->f_pos, ino, type); 1895 } 1896 1897 static unsigned name_to_int(struct dentry *dentry) 1898 { 1899 const char *name = dentry->d_name.name; 1900 int len = dentry->d_name.len; 1901 unsigned n = 0; 1902 1903 if (len > 1 && *name == '0') 1904 goto out; 1905 while (len-- > 0) { 1906 unsigned c = *name++ - '0'; 1907 if (c > 9) 1908 goto out; 1909 if (n >= (~0U-9)/10) 1910 goto out; 1911 n *= 10; 1912 n += c; 1913 } 1914 return n; 1915 out: 1916 return ~0U; 1917 } 1918 1919 #define PROC_FDINFO_MAX 64 1920 1921 static int proc_fd_info(struct inode *inode, struct path *path, char *info) 1922 { 1923 struct task_struct *task = get_proc_task(inode); 1924 struct files_struct *files = NULL; 1925 struct file *file; 1926 int fd = proc_fd(inode); 1927 1928 if (task) { 1929 files = get_files_struct(task); 1930 put_task_struct(task); 1931 } 1932 if (files) { 1933 /* 1934 * We are not taking a ref to the file structure, so we must 1935 * hold ->file_lock. 1936 */ 1937 spin_lock(&files->file_lock); 1938 file = fcheck_files(files, fd); 1939 if (file) { 1940 if (path) { 1941 *path = file->f_path; 1942 path_get(&file->f_path); 1943 } 1944 if (info) 1945 snprintf(info, PROC_FDINFO_MAX, 1946 "pos:\t%lli\n" 1947 "flags:\t0%o\n", 1948 (long long) file->f_pos, 1949 file->f_flags); 1950 spin_unlock(&files->file_lock); 1951 put_files_struct(files); 1952 return 0; 1953 } 1954 spin_unlock(&files->file_lock); 1955 put_files_struct(files); 1956 } 1957 return -ENOENT; 1958 } 1959 1960 static int proc_fd_link(struct inode *inode, struct path *path) 1961 { 1962 return proc_fd_info(inode, path, NULL); 1963 } 1964 1965 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1966 { 1967 struct inode *inode = dentry->d_inode; 1968 struct task_struct *task = get_proc_task(inode); 1969 int fd = proc_fd(inode); 1970 struct files_struct *files; 1971 const struct cred *cred; 1972 1973 if (task) { 1974 files = get_files_struct(task); 1975 if (files) { 1976 rcu_read_lock(); 1977 if (fcheck_files(files, fd)) { 1978 rcu_read_unlock(); 1979 put_files_struct(files); 1980 if (task_dumpable(task)) { 1981 rcu_read_lock(); 1982 cred = __task_cred(task); 1983 inode->i_uid = cred->euid; 1984 inode->i_gid = cred->egid; 1985 rcu_read_unlock(); 1986 } else { 1987 inode->i_uid = 0; 1988 inode->i_gid = 0; 1989 } 1990 inode->i_mode &= ~(S_ISUID | S_ISGID); 1991 security_task_to_inode(task, inode); 1992 put_task_struct(task); 1993 return 1; 1994 } 1995 rcu_read_unlock(); 1996 put_files_struct(files); 1997 } 1998 put_task_struct(task); 1999 } 2000 d_drop(dentry); 2001 return 0; 2002 } 2003 2004 static const struct dentry_operations tid_fd_dentry_operations = 2005 { 2006 .d_revalidate = tid_fd_revalidate, 2007 .d_delete = pid_delete_dentry, 2008 }; 2009 2010 static struct dentry *proc_fd_instantiate(struct inode *dir, 2011 struct dentry *dentry, struct task_struct *task, const void *ptr) 2012 { 2013 unsigned fd = *(const unsigned *)ptr; 2014 struct file *file; 2015 struct files_struct *files; 2016 struct inode *inode; 2017 struct proc_inode *ei; 2018 struct dentry *error = ERR_PTR(-ENOENT); 2019 2020 inode = proc_pid_make_inode(dir->i_sb, task); 2021 if (!inode) 2022 goto out; 2023 ei = PROC_I(inode); 2024 ei->fd = fd; 2025 files = get_files_struct(task); 2026 if (!files) 2027 goto out_iput; 2028 inode->i_mode = S_IFLNK; 2029 2030 /* 2031 * We are not taking a ref to the file structure, so we must 2032 * hold ->file_lock. 2033 */ 2034 spin_lock(&files->file_lock); 2035 file = fcheck_files(files, fd); 2036 if (!file) 2037 goto out_unlock; 2038 if (file->f_mode & FMODE_READ) 2039 inode->i_mode |= S_IRUSR | S_IXUSR; 2040 if (file->f_mode & FMODE_WRITE) 2041 inode->i_mode |= S_IWUSR | S_IXUSR; 2042 spin_unlock(&files->file_lock); 2043 put_files_struct(files); 2044 2045 inode->i_op = &proc_pid_link_inode_operations; 2046 inode->i_size = 64; 2047 ei->op.proc_get_link = proc_fd_link; 2048 dentry->d_op = &tid_fd_dentry_operations; 2049 d_add(dentry, inode); 2050 /* Close the race of the process dying before we return the dentry */ 2051 if (tid_fd_revalidate(dentry, NULL)) 2052 error = NULL; 2053 2054 out: 2055 return error; 2056 out_unlock: 2057 spin_unlock(&files->file_lock); 2058 put_files_struct(files); 2059 out_iput: 2060 iput(inode); 2061 goto out; 2062 } 2063 2064 static struct dentry *proc_lookupfd_common(struct inode *dir, 2065 struct dentry *dentry, 2066 instantiate_t instantiate) 2067 { 2068 struct task_struct *task = get_proc_task(dir); 2069 unsigned fd = name_to_int(dentry); 2070 struct dentry *result = ERR_PTR(-ENOENT); 2071 2072 if (!task) 2073 goto out_no_task; 2074 if (fd == ~0U) 2075 goto out; 2076 2077 result = instantiate(dir, dentry, task, &fd); 2078 out: 2079 put_task_struct(task); 2080 out_no_task: 2081 return result; 2082 } 2083 2084 static int proc_readfd_common(struct file * filp, void * dirent, 2085 filldir_t filldir, instantiate_t instantiate) 2086 { 2087 struct dentry *dentry = filp->f_path.dentry; 2088 struct inode *inode = dentry->d_inode; 2089 struct task_struct *p = get_proc_task(inode); 2090 unsigned int fd, ino; 2091 int retval; 2092 struct files_struct * files; 2093 2094 retval = -ENOENT; 2095 if (!p) 2096 goto out_no_task; 2097 retval = 0; 2098 2099 fd = filp->f_pos; 2100 switch (fd) { 2101 case 0: 2102 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 2103 goto out; 2104 filp->f_pos++; 2105 case 1: 2106 ino = parent_ino(dentry); 2107 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 2108 goto out; 2109 filp->f_pos++; 2110 default: 2111 files = get_files_struct(p); 2112 if (!files) 2113 goto out; 2114 rcu_read_lock(); 2115 for (fd = filp->f_pos-2; 2116 fd < files_fdtable(files)->max_fds; 2117 fd++, filp->f_pos++) { 2118 char name[PROC_NUMBUF]; 2119 int len; 2120 2121 if (!fcheck_files(files, fd)) 2122 continue; 2123 rcu_read_unlock(); 2124 2125 len = snprintf(name, sizeof(name), "%d", fd); 2126 if (proc_fill_cache(filp, dirent, filldir, 2127 name, len, instantiate, 2128 p, &fd) < 0) { 2129 rcu_read_lock(); 2130 break; 2131 } 2132 rcu_read_lock(); 2133 } 2134 rcu_read_unlock(); 2135 put_files_struct(files); 2136 } 2137 out: 2138 put_task_struct(p); 2139 out_no_task: 2140 return retval; 2141 } 2142 2143 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 2144 struct nameidata *nd) 2145 { 2146 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 2147 } 2148 2149 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 2150 { 2151 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 2152 } 2153 2154 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 2155 size_t len, loff_t *ppos) 2156 { 2157 char tmp[PROC_FDINFO_MAX]; 2158 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); 2159 if (!err) 2160 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 2161 return err; 2162 } 2163 2164 static const struct file_operations proc_fdinfo_file_operations = { 2165 .open = nonseekable_open, 2166 .read = proc_fdinfo_read, 2167 .llseek = no_llseek, 2168 }; 2169 2170 static const struct file_operations proc_fd_operations = { 2171 .read = generic_read_dir, 2172 .readdir = proc_readfd, 2173 .llseek = default_llseek, 2174 }; 2175 2176 /* 2177 * /proc/pid/fd needs a special permission handler so that a process can still 2178 * access /proc/self/fd after it has executed a setuid(). 2179 */ 2180 static int proc_fd_permission(struct inode *inode, int mask) 2181 { 2182 int rv; 2183 2184 rv = generic_permission(inode, mask, NULL); 2185 if (rv == 0) 2186 return 0; 2187 if (task_pid(current) == proc_pid(inode)) 2188 rv = 0; 2189 return rv; 2190 } 2191 2192 /* 2193 * proc directories can do almost nothing.. 2194 */ 2195 static const struct inode_operations proc_fd_inode_operations = { 2196 .lookup = proc_lookupfd, 2197 .permission = proc_fd_permission, 2198 .setattr = proc_setattr, 2199 }; 2200 2201 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 2202 struct dentry *dentry, struct task_struct *task, const void *ptr) 2203 { 2204 unsigned fd = *(unsigned *)ptr; 2205 struct inode *inode; 2206 struct proc_inode *ei; 2207 struct dentry *error = ERR_PTR(-ENOENT); 2208 2209 inode = proc_pid_make_inode(dir->i_sb, task); 2210 if (!inode) 2211 goto out; 2212 ei = PROC_I(inode); 2213 ei->fd = fd; 2214 inode->i_mode = S_IFREG | S_IRUSR; 2215 inode->i_fop = &proc_fdinfo_file_operations; 2216 dentry->d_op = &tid_fd_dentry_operations; 2217 d_add(dentry, inode); 2218 /* Close the race of the process dying before we return the dentry */ 2219 if (tid_fd_revalidate(dentry, NULL)) 2220 error = NULL; 2221 2222 out: 2223 return error; 2224 } 2225 2226 static struct dentry *proc_lookupfdinfo(struct inode *dir, 2227 struct dentry *dentry, 2228 struct nameidata *nd) 2229 { 2230 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 2231 } 2232 2233 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 2234 { 2235 return proc_readfd_common(filp, dirent, filldir, 2236 proc_fdinfo_instantiate); 2237 } 2238 2239 static const struct file_operations proc_fdinfo_operations = { 2240 .read = generic_read_dir, 2241 .readdir = proc_readfdinfo, 2242 .llseek = default_llseek, 2243 }; 2244 2245 /* 2246 * proc directories can do almost nothing.. 2247 */ 2248 static const struct inode_operations proc_fdinfo_inode_operations = { 2249 .lookup = proc_lookupfdinfo, 2250 .setattr = proc_setattr, 2251 }; 2252 2253 2254 static struct dentry *proc_pident_instantiate(struct inode *dir, 2255 struct dentry *dentry, struct task_struct *task, const void *ptr) 2256 { 2257 const struct pid_entry *p = ptr; 2258 struct inode *inode; 2259 struct proc_inode *ei; 2260 struct dentry *error = ERR_PTR(-ENOENT); 2261 2262 inode = proc_pid_make_inode(dir->i_sb, task); 2263 if (!inode) 2264 goto out; 2265 2266 ei = PROC_I(inode); 2267 inode->i_mode = p->mode; 2268 if (S_ISDIR(inode->i_mode)) 2269 inode->i_nlink = 2; /* Use getattr to fix if necessary */ 2270 if (p->iop) 2271 inode->i_op = p->iop; 2272 if (p->fop) 2273 inode->i_fop = p->fop; 2274 ei->op = p->op; 2275 dentry->d_op = &pid_dentry_operations; 2276 d_add(dentry, inode); 2277 /* Close the race of the process dying before we return the dentry */ 2278 if (pid_revalidate(dentry, NULL)) 2279 error = NULL; 2280 out: 2281 return error; 2282 } 2283 2284 static struct dentry *proc_pident_lookup(struct inode *dir, 2285 struct dentry *dentry, 2286 const struct pid_entry *ents, 2287 unsigned int nents) 2288 { 2289 struct dentry *error; 2290 struct task_struct *task = get_proc_task(dir); 2291 const struct pid_entry *p, *last; 2292 2293 error = ERR_PTR(-ENOENT); 2294 2295 if (!task) 2296 goto out_no_task; 2297 2298 /* 2299 * Yes, it does not scale. And it should not. Don't add 2300 * new entries into /proc/<tgid>/ without very good reasons. 2301 */ 2302 last = &ents[nents - 1]; 2303 for (p = ents; p <= last; p++) { 2304 if (p->len != dentry->d_name.len) 2305 continue; 2306 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2307 break; 2308 } 2309 if (p > last) 2310 goto out; 2311 2312 error = proc_pident_instantiate(dir, dentry, task, p); 2313 out: 2314 put_task_struct(task); 2315 out_no_task: 2316 return error; 2317 } 2318 2319 static int proc_pident_fill_cache(struct file *filp, void *dirent, 2320 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2321 { 2322 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2323 proc_pident_instantiate, task, p); 2324 } 2325 2326 static int proc_pident_readdir(struct file *filp, 2327 void *dirent, filldir_t filldir, 2328 const struct pid_entry *ents, unsigned int nents) 2329 { 2330 int i; 2331 struct dentry *dentry = filp->f_path.dentry; 2332 struct inode *inode = dentry->d_inode; 2333 struct task_struct *task = get_proc_task(inode); 2334 const struct pid_entry *p, *last; 2335 ino_t ino; 2336 int ret; 2337 2338 ret = -ENOENT; 2339 if (!task) 2340 goto out_no_task; 2341 2342 ret = 0; 2343 i = filp->f_pos; 2344 switch (i) { 2345 case 0: 2346 ino = inode->i_ino; 2347 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 2348 goto out; 2349 i++; 2350 filp->f_pos++; 2351 /* fall through */ 2352 case 1: 2353 ino = parent_ino(dentry); 2354 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 2355 goto out; 2356 i++; 2357 filp->f_pos++; 2358 /* fall through */ 2359 default: 2360 i -= 2; 2361 if (i >= nents) { 2362 ret = 1; 2363 goto out; 2364 } 2365 p = ents + i; 2366 last = &ents[nents - 1]; 2367 while (p <= last) { 2368 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2369 goto out; 2370 filp->f_pos++; 2371 p++; 2372 } 2373 } 2374 2375 ret = 1; 2376 out: 2377 put_task_struct(task); 2378 out_no_task: 2379 return ret; 2380 } 2381 2382 #ifdef CONFIG_SECURITY 2383 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2384 size_t count, loff_t *ppos) 2385 { 2386 struct inode * inode = file->f_path.dentry->d_inode; 2387 char *p = NULL; 2388 ssize_t length; 2389 struct task_struct *task = get_proc_task(inode); 2390 2391 if (!task) 2392 return -ESRCH; 2393 2394 length = security_getprocattr(task, 2395 (char*)file->f_path.dentry->d_name.name, 2396 &p); 2397 put_task_struct(task); 2398 if (length > 0) 2399 length = simple_read_from_buffer(buf, count, ppos, p, length); 2400 kfree(p); 2401 return length; 2402 } 2403 2404 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2405 size_t count, loff_t *ppos) 2406 { 2407 struct inode * inode = file->f_path.dentry->d_inode; 2408 char *page; 2409 ssize_t length; 2410 struct task_struct *task = get_proc_task(inode); 2411 2412 length = -ESRCH; 2413 if (!task) 2414 goto out_no_task; 2415 if (count > PAGE_SIZE) 2416 count = PAGE_SIZE; 2417 2418 /* No partial writes. */ 2419 length = -EINVAL; 2420 if (*ppos != 0) 2421 goto out; 2422 2423 length = -ENOMEM; 2424 page = (char*)__get_free_page(GFP_TEMPORARY); 2425 if (!page) 2426 goto out; 2427 2428 length = -EFAULT; 2429 if (copy_from_user(page, buf, count)) 2430 goto out_free; 2431 2432 /* Guard against adverse ptrace interaction */ 2433 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex); 2434 if (length < 0) 2435 goto out_free; 2436 2437 length = security_setprocattr(task, 2438 (char*)file->f_path.dentry->d_name.name, 2439 (void*)page, count); 2440 mutex_unlock(&task->signal->cred_guard_mutex); 2441 out_free: 2442 free_page((unsigned long) page); 2443 out: 2444 put_task_struct(task); 2445 out_no_task: 2446 return length; 2447 } 2448 2449 static const struct file_operations proc_pid_attr_operations = { 2450 .read = proc_pid_attr_read, 2451 .write = proc_pid_attr_write, 2452 .llseek = generic_file_llseek, 2453 }; 2454 2455 static const struct pid_entry attr_dir_stuff[] = { 2456 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2457 REG("prev", S_IRUGO, proc_pid_attr_operations), 2458 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2459 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2460 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2461 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2462 }; 2463 2464 static int proc_attr_dir_readdir(struct file * filp, 2465 void * dirent, filldir_t filldir) 2466 { 2467 return proc_pident_readdir(filp,dirent,filldir, 2468 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2469 } 2470 2471 static const struct file_operations proc_attr_dir_operations = { 2472 .read = generic_read_dir, 2473 .readdir = proc_attr_dir_readdir, 2474 .llseek = default_llseek, 2475 }; 2476 2477 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2478 struct dentry *dentry, struct nameidata *nd) 2479 { 2480 return proc_pident_lookup(dir, dentry, 2481 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2482 } 2483 2484 static const struct inode_operations proc_attr_dir_inode_operations = { 2485 .lookup = proc_attr_dir_lookup, 2486 .getattr = pid_getattr, 2487 .setattr = proc_setattr, 2488 }; 2489 2490 #endif 2491 2492 #ifdef CONFIG_ELF_CORE 2493 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2494 size_t count, loff_t *ppos) 2495 { 2496 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2497 struct mm_struct *mm; 2498 char buffer[PROC_NUMBUF]; 2499 size_t len; 2500 int ret; 2501 2502 if (!task) 2503 return -ESRCH; 2504 2505 ret = 0; 2506 mm = get_task_mm(task); 2507 if (mm) { 2508 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2509 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2510 MMF_DUMP_FILTER_SHIFT)); 2511 mmput(mm); 2512 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2513 } 2514 2515 put_task_struct(task); 2516 2517 return ret; 2518 } 2519 2520 static ssize_t proc_coredump_filter_write(struct file *file, 2521 const char __user *buf, 2522 size_t count, 2523 loff_t *ppos) 2524 { 2525 struct task_struct *task; 2526 struct mm_struct *mm; 2527 char buffer[PROC_NUMBUF], *end; 2528 unsigned int val; 2529 int ret; 2530 int i; 2531 unsigned long mask; 2532 2533 ret = -EFAULT; 2534 memset(buffer, 0, sizeof(buffer)); 2535 if (count > sizeof(buffer) - 1) 2536 count = sizeof(buffer) - 1; 2537 if (copy_from_user(buffer, buf, count)) 2538 goto out_no_task; 2539 2540 ret = -EINVAL; 2541 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2542 if (*end == '\n') 2543 end++; 2544 if (end - buffer == 0) 2545 goto out_no_task; 2546 2547 ret = -ESRCH; 2548 task = get_proc_task(file->f_dentry->d_inode); 2549 if (!task) 2550 goto out_no_task; 2551 2552 ret = end - buffer; 2553 mm = get_task_mm(task); 2554 if (!mm) 2555 goto out_no_mm; 2556 2557 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2558 if (val & mask) 2559 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2560 else 2561 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2562 } 2563 2564 mmput(mm); 2565 out_no_mm: 2566 put_task_struct(task); 2567 out_no_task: 2568 return ret; 2569 } 2570 2571 static const struct file_operations proc_coredump_filter_operations = { 2572 .read = proc_coredump_filter_read, 2573 .write = proc_coredump_filter_write, 2574 .llseek = generic_file_llseek, 2575 }; 2576 #endif 2577 2578 /* 2579 * /proc/self: 2580 */ 2581 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2582 int buflen) 2583 { 2584 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2585 pid_t tgid = task_tgid_nr_ns(current, ns); 2586 char tmp[PROC_NUMBUF]; 2587 if (!tgid) 2588 return -ENOENT; 2589 sprintf(tmp, "%d", tgid); 2590 return vfs_readlink(dentry,buffer,buflen,tmp); 2591 } 2592 2593 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2594 { 2595 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2596 pid_t tgid = task_tgid_nr_ns(current, ns); 2597 char *name = ERR_PTR(-ENOENT); 2598 if (tgid) { 2599 name = __getname(); 2600 if (!name) 2601 name = ERR_PTR(-ENOMEM); 2602 else 2603 sprintf(name, "%d", tgid); 2604 } 2605 nd_set_link(nd, name); 2606 return NULL; 2607 } 2608 2609 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd, 2610 void *cookie) 2611 { 2612 char *s = nd_get_link(nd); 2613 if (!IS_ERR(s)) 2614 __putname(s); 2615 } 2616 2617 static const struct inode_operations proc_self_inode_operations = { 2618 .readlink = proc_self_readlink, 2619 .follow_link = proc_self_follow_link, 2620 .put_link = proc_self_put_link, 2621 }; 2622 2623 /* 2624 * proc base 2625 * 2626 * These are the directory entries in the root directory of /proc 2627 * that properly belong to the /proc filesystem, as they describe 2628 * describe something that is process related. 2629 */ 2630 static const struct pid_entry proc_base_stuff[] = { 2631 NOD("self", S_IFLNK|S_IRWXUGO, 2632 &proc_self_inode_operations, NULL, {}), 2633 }; 2634 2635 /* 2636 * Exceptional case: normally we are not allowed to unhash a busy 2637 * directory. In this case, however, we can do it - no aliasing problems 2638 * due to the way we treat inodes. 2639 */ 2640 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) 2641 { 2642 struct inode *inode = dentry->d_inode; 2643 struct task_struct *task = get_proc_task(inode); 2644 if (task) { 2645 put_task_struct(task); 2646 return 1; 2647 } 2648 d_drop(dentry); 2649 return 0; 2650 } 2651 2652 static const struct dentry_operations proc_base_dentry_operations = 2653 { 2654 .d_revalidate = proc_base_revalidate, 2655 .d_delete = pid_delete_dentry, 2656 }; 2657 2658 static struct dentry *proc_base_instantiate(struct inode *dir, 2659 struct dentry *dentry, struct task_struct *task, const void *ptr) 2660 { 2661 const struct pid_entry *p = ptr; 2662 struct inode *inode; 2663 struct proc_inode *ei; 2664 struct dentry *error; 2665 2666 /* Allocate the inode */ 2667 error = ERR_PTR(-ENOMEM); 2668 inode = new_inode(dir->i_sb); 2669 if (!inode) 2670 goto out; 2671 2672 /* Initialize the inode */ 2673 ei = PROC_I(inode); 2674 inode->i_ino = get_next_ino(); 2675 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2676 2677 /* 2678 * grab the reference to the task. 2679 */ 2680 ei->pid = get_task_pid(task, PIDTYPE_PID); 2681 if (!ei->pid) 2682 goto out_iput; 2683 2684 inode->i_mode = p->mode; 2685 if (S_ISDIR(inode->i_mode)) 2686 inode->i_nlink = 2; 2687 if (S_ISLNK(inode->i_mode)) 2688 inode->i_size = 64; 2689 if (p->iop) 2690 inode->i_op = p->iop; 2691 if (p->fop) 2692 inode->i_fop = p->fop; 2693 ei->op = p->op; 2694 dentry->d_op = &proc_base_dentry_operations; 2695 d_add(dentry, inode); 2696 error = NULL; 2697 out: 2698 return error; 2699 out_iput: 2700 iput(inode); 2701 goto out; 2702 } 2703 2704 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2705 { 2706 struct dentry *error; 2707 struct task_struct *task = get_proc_task(dir); 2708 const struct pid_entry *p, *last; 2709 2710 error = ERR_PTR(-ENOENT); 2711 2712 if (!task) 2713 goto out_no_task; 2714 2715 /* Lookup the directory entry */ 2716 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2717 for (p = proc_base_stuff; p <= last; p++) { 2718 if (p->len != dentry->d_name.len) 2719 continue; 2720 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2721 break; 2722 } 2723 if (p > last) 2724 goto out; 2725 2726 error = proc_base_instantiate(dir, dentry, task, p); 2727 2728 out: 2729 put_task_struct(task); 2730 out_no_task: 2731 return error; 2732 } 2733 2734 static int proc_base_fill_cache(struct file *filp, void *dirent, 2735 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2736 { 2737 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2738 proc_base_instantiate, task, p); 2739 } 2740 2741 #ifdef CONFIG_TASK_IO_ACCOUNTING 2742 static int do_io_accounting(struct task_struct *task, char *buffer, int whole) 2743 { 2744 struct task_io_accounting acct = task->ioac; 2745 unsigned long flags; 2746 2747 if (whole && lock_task_sighand(task, &flags)) { 2748 struct task_struct *t = task; 2749 2750 task_io_accounting_add(&acct, &task->signal->ioac); 2751 while_each_thread(task, t) 2752 task_io_accounting_add(&acct, &t->ioac); 2753 2754 unlock_task_sighand(task, &flags); 2755 } 2756 return sprintf(buffer, 2757 "rchar: %llu\n" 2758 "wchar: %llu\n" 2759 "syscr: %llu\n" 2760 "syscw: %llu\n" 2761 "read_bytes: %llu\n" 2762 "write_bytes: %llu\n" 2763 "cancelled_write_bytes: %llu\n", 2764 (unsigned long long)acct.rchar, 2765 (unsigned long long)acct.wchar, 2766 (unsigned long long)acct.syscr, 2767 (unsigned long long)acct.syscw, 2768 (unsigned long long)acct.read_bytes, 2769 (unsigned long long)acct.write_bytes, 2770 (unsigned long long)acct.cancelled_write_bytes); 2771 } 2772 2773 static int proc_tid_io_accounting(struct task_struct *task, char *buffer) 2774 { 2775 return do_io_accounting(task, buffer, 0); 2776 } 2777 2778 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer) 2779 { 2780 return do_io_accounting(task, buffer, 1); 2781 } 2782 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2783 2784 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2785 struct pid *pid, struct task_struct *task) 2786 { 2787 seq_printf(m, "%08x\n", task->personality); 2788 return 0; 2789 } 2790 2791 /* 2792 * Thread groups 2793 */ 2794 static const struct file_operations proc_task_operations; 2795 static const struct inode_operations proc_task_inode_operations; 2796 2797 static const struct pid_entry tgid_base_stuff[] = { 2798 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2799 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2800 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2801 #ifdef CONFIG_NET 2802 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2803 #endif 2804 REG("environ", S_IRUSR, proc_environ_operations), 2805 INF("auxv", S_IRUSR, proc_pid_auxv), 2806 ONE("status", S_IRUGO, proc_pid_status), 2807 ONE("personality", S_IRUSR, proc_pid_personality), 2808 INF("limits", S_IRUGO, proc_pid_limits), 2809 #ifdef CONFIG_SCHED_DEBUG 2810 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2811 #endif 2812 #ifdef CONFIG_SCHED_AUTOGROUP 2813 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2814 #endif 2815 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2816 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2817 INF("syscall", S_IRUSR, proc_pid_syscall), 2818 #endif 2819 INF("cmdline", S_IRUGO, proc_pid_cmdline), 2820 ONE("stat", S_IRUGO, proc_tgid_stat), 2821 ONE("statm", S_IRUGO, proc_pid_statm), 2822 REG("maps", S_IRUGO, proc_maps_operations), 2823 #ifdef CONFIG_NUMA 2824 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 2825 #endif 2826 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2827 LNK("cwd", proc_cwd_link), 2828 LNK("root", proc_root_link), 2829 LNK("exe", proc_exe_link), 2830 REG("mounts", S_IRUGO, proc_mounts_operations), 2831 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2832 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2833 #ifdef CONFIG_PROC_PAGE_MONITOR 2834 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2835 REG("smaps", S_IRUGO, proc_smaps_operations), 2836 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2837 #endif 2838 #ifdef CONFIG_SECURITY 2839 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2840 #endif 2841 #ifdef CONFIG_KALLSYMS 2842 INF("wchan", S_IRUGO, proc_pid_wchan), 2843 #endif 2844 #ifdef CONFIG_STACKTRACE 2845 ONE("stack", S_IRUSR, proc_pid_stack), 2846 #endif 2847 #ifdef CONFIG_SCHEDSTATS 2848 INF("schedstat", S_IRUGO, proc_pid_schedstat), 2849 #endif 2850 #ifdef CONFIG_LATENCYTOP 2851 REG("latency", S_IRUGO, proc_lstats_operations), 2852 #endif 2853 #ifdef CONFIG_PROC_PID_CPUSET 2854 REG("cpuset", S_IRUGO, proc_cpuset_operations), 2855 #endif 2856 #ifdef CONFIG_CGROUPS 2857 REG("cgroup", S_IRUGO, proc_cgroup_operations), 2858 #endif 2859 INF("oom_score", S_IRUGO, proc_oom_score), 2860 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 2861 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2862 #ifdef CONFIG_AUDITSYSCALL 2863 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2864 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2865 #endif 2866 #ifdef CONFIG_FAULT_INJECTION 2867 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2868 #endif 2869 #ifdef CONFIG_ELF_CORE 2870 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2871 #endif 2872 #ifdef CONFIG_TASK_IO_ACCOUNTING 2873 INF("io", S_IRUGO, proc_tgid_io_accounting), 2874 #endif 2875 }; 2876 2877 static int proc_tgid_base_readdir(struct file * filp, 2878 void * dirent, filldir_t filldir) 2879 { 2880 return proc_pident_readdir(filp,dirent,filldir, 2881 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2882 } 2883 2884 static const struct file_operations proc_tgid_base_operations = { 2885 .read = generic_read_dir, 2886 .readdir = proc_tgid_base_readdir, 2887 .llseek = default_llseek, 2888 }; 2889 2890 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2891 return proc_pident_lookup(dir, dentry, 2892 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2893 } 2894 2895 static const struct inode_operations proc_tgid_base_inode_operations = { 2896 .lookup = proc_tgid_base_lookup, 2897 .getattr = pid_getattr, 2898 .setattr = proc_setattr, 2899 }; 2900 2901 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2902 { 2903 struct dentry *dentry, *leader, *dir; 2904 char buf[PROC_NUMBUF]; 2905 struct qstr name; 2906 2907 name.name = buf; 2908 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2909 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2910 if (dentry) { 2911 shrink_dcache_parent(dentry); 2912 d_drop(dentry); 2913 dput(dentry); 2914 } 2915 2916 name.name = buf; 2917 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2918 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2919 if (!leader) 2920 goto out; 2921 2922 name.name = "task"; 2923 name.len = strlen(name.name); 2924 dir = d_hash_and_lookup(leader, &name); 2925 if (!dir) 2926 goto out_put_leader; 2927 2928 name.name = buf; 2929 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2930 dentry = d_hash_and_lookup(dir, &name); 2931 if (dentry) { 2932 shrink_dcache_parent(dentry); 2933 d_drop(dentry); 2934 dput(dentry); 2935 } 2936 2937 dput(dir); 2938 out_put_leader: 2939 dput(leader); 2940 out: 2941 return; 2942 } 2943 2944 /** 2945 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2946 * @task: task that should be flushed. 2947 * 2948 * When flushing dentries from proc, one needs to flush them from global 2949 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2950 * in. This call is supposed to do all of this job. 2951 * 2952 * Looks in the dcache for 2953 * /proc/@pid 2954 * /proc/@tgid/task/@pid 2955 * if either directory is present flushes it and all of it'ts children 2956 * from the dcache. 2957 * 2958 * It is safe and reasonable to cache /proc entries for a task until 2959 * that task exits. After that they just clog up the dcache with 2960 * useless entries, possibly causing useful dcache entries to be 2961 * flushed instead. This routine is proved to flush those useless 2962 * dcache entries at process exit time. 2963 * 2964 * NOTE: This routine is just an optimization so it does not guarantee 2965 * that no dcache entries will exist at process exit time it 2966 * just makes it very unlikely that any will persist. 2967 */ 2968 2969 void proc_flush_task(struct task_struct *task) 2970 { 2971 int i; 2972 struct pid *pid, *tgid; 2973 struct upid *upid; 2974 2975 pid = task_pid(task); 2976 tgid = task_tgid(task); 2977 2978 for (i = 0; i <= pid->level; i++) { 2979 upid = &pid->numbers[i]; 2980 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 2981 tgid->numbers[i].nr); 2982 } 2983 2984 upid = &pid->numbers[pid->level]; 2985 if (upid->nr == 1) 2986 pid_ns_release_proc(upid->ns); 2987 } 2988 2989 static struct dentry *proc_pid_instantiate(struct inode *dir, 2990 struct dentry * dentry, 2991 struct task_struct *task, const void *ptr) 2992 { 2993 struct dentry *error = ERR_PTR(-ENOENT); 2994 struct inode *inode; 2995 2996 inode = proc_pid_make_inode(dir->i_sb, task); 2997 if (!inode) 2998 goto out; 2999 3000 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3001 inode->i_op = &proc_tgid_base_inode_operations; 3002 inode->i_fop = &proc_tgid_base_operations; 3003 inode->i_flags|=S_IMMUTABLE; 3004 3005 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff, 3006 ARRAY_SIZE(tgid_base_stuff)); 3007 3008 dentry->d_op = &pid_dentry_operations; 3009 3010 d_add(dentry, inode); 3011 /* Close the race of the process dying before we return the dentry */ 3012 if (pid_revalidate(dentry, NULL)) 3013 error = NULL; 3014 out: 3015 return error; 3016 } 3017 3018 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 3019 { 3020 struct dentry *result; 3021 struct task_struct *task; 3022 unsigned tgid; 3023 struct pid_namespace *ns; 3024 3025 result = proc_base_lookup(dir, dentry); 3026 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 3027 goto out; 3028 3029 tgid = name_to_int(dentry); 3030 if (tgid == ~0U) 3031 goto out; 3032 3033 ns = dentry->d_sb->s_fs_info; 3034 rcu_read_lock(); 3035 task = find_task_by_pid_ns(tgid, ns); 3036 if (task) 3037 get_task_struct(task); 3038 rcu_read_unlock(); 3039 if (!task) 3040 goto out; 3041 3042 result = proc_pid_instantiate(dir, dentry, task, NULL); 3043 put_task_struct(task); 3044 out: 3045 return result; 3046 } 3047 3048 /* 3049 * Find the first task with tgid >= tgid 3050 * 3051 */ 3052 struct tgid_iter { 3053 unsigned int tgid; 3054 struct task_struct *task; 3055 }; 3056 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3057 { 3058 struct pid *pid; 3059 3060 if (iter.task) 3061 put_task_struct(iter.task); 3062 rcu_read_lock(); 3063 retry: 3064 iter.task = NULL; 3065 pid = find_ge_pid(iter.tgid, ns); 3066 if (pid) { 3067 iter.tgid = pid_nr_ns(pid, ns); 3068 iter.task = pid_task(pid, PIDTYPE_PID); 3069 /* What we to know is if the pid we have find is the 3070 * pid of a thread_group_leader. Testing for task 3071 * being a thread_group_leader is the obvious thing 3072 * todo but there is a window when it fails, due to 3073 * the pid transfer logic in de_thread. 3074 * 3075 * So we perform the straight forward test of seeing 3076 * if the pid we have found is the pid of a thread 3077 * group leader, and don't worry if the task we have 3078 * found doesn't happen to be a thread group leader. 3079 * As we don't care in the case of readdir. 3080 */ 3081 if (!iter.task || !has_group_leader_pid(iter.task)) { 3082 iter.tgid += 1; 3083 goto retry; 3084 } 3085 get_task_struct(iter.task); 3086 } 3087 rcu_read_unlock(); 3088 return iter; 3089 } 3090 3091 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 3092 3093 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3094 struct tgid_iter iter) 3095 { 3096 char name[PROC_NUMBUF]; 3097 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 3098 return proc_fill_cache(filp, dirent, filldir, name, len, 3099 proc_pid_instantiate, iter.task, NULL); 3100 } 3101 3102 /* for the /proc/ directory itself, after non-process stuff has been done */ 3103 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 3104 { 3105 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; 3106 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode); 3107 struct tgid_iter iter; 3108 struct pid_namespace *ns; 3109 3110 if (!reaper) 3111 goto out_no_task; 3112 3113 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 3114 const struct pid_entry *p = &proc_base_stuff[nr]; 3115 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 3116 goto out; 3117 } 3118 3119 ns = filp->f_dentry->d_sb->s_fs_info; 3120 iter.task = NULL; 3121 iter.tgid = filp->f_pos - TGID_OFFSET; 3122 for (iter = next_tgid(ns, iter); 3123 iter.task; 3124 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3125 filp->f_pos = iter.tgid + TGID_OFFSET; 3126 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) { 3127 put_task_struct(iter.task); 3128 goto out; 3129 } 3130 } 3131 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 3132 out: 3133 put_task_struct(reaper); 3134 out_no_task: 3135 return 0; 3136 } 3137 3138 /* 3139 * Tasks 3140 */ 3141 static const struct pid_entry tid_base_stuff[] = { 3142 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3143 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3144 REG("environ", S_IRUSR, proc_environ_operations), 3145 INF("auxv", S_IRUSR, proc_pid_auxv), 3146 ONE("status", S_IRUGO, proc_pid_status), 3147 ONE("personality", S_IRUSR, proc_pid_personality), 3148 INF("limits", S_IRUGO, proc_pid_limits), 3149 #ifdef CONFIG_SCHED_DEBUG 3150 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3151 #endif 3152 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3153 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3154 INF("syscall", S_IRUSR, proc_pid_syscall), 3155 #endif 3156 INF("cmdline", S_IRUGO, proc_pid_cmdline), 3157 ONE("stat", S_IRUGO, proc_tid_stat), 3158 ONE("statm", S_IRUGO, proc_pid_statm), 3159 REG("maps", S_IRUGO, proc_maps_operations), 3160 #ifdef CONFIG_NUMA 3161 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 3162 #endif 3163 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3164 LNK("cwd", proc_cwd_link), 3165 LNK("root", proc_root_link), 3166 LNK("exe", proc_exe_link), 3167 REG("mounts", S_IRUGO, proc_mounts_operations), 3168 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3169 #ifdef CONFIG_PROC_PAGE_MONITOR 3170 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3171 REG("smaps", S_IRUGO, proc_smaps_operations), 3172 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3173 #endif 3174 #ifdef CONFIG_SECURITY 3175 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3176 #endif 3177 #ifdef CONFIG_KALLSYMS 3178 INF("wchan", S_IRUGO, proc_pid_wchan), 3179 #endif 3180 #ifdef CONFIG_STACKTRACE 3181 ONE("stack", S_IRUSR, proc_pid_stack), 3182 #endif 3183 #ifdef CONFIG_SCHEDSTATS 3184 INF("schedstat", S_IRUGO, proc_pid_schedstat), 3185 #endif 3186 #ifdef CONFIG_LATENCYTOP 3187 REG("latency", S_IRUGO, proc_lstats_operations), 3188 #endif 3189 #ifdef CONFIG_PROC_PID_CPUSET 3190 REG("cpuset", S_IRUGO, proc_cpuset_operations), 3191 #endif 3192 #ifdef CONFIG_CGROUPS 3193 REG("cgroup", S_IRUGO, proc_cgroup_operations), 3194 #endif 3195 INF("oom_score", S_IRUGO, proc_oom_score), 3196 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 3197 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3198 #ifdef CONFIG_AUDITSYSCALL 3199 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3200 REG("sessionid", S_IRUSR, proc_sessionid_operations), 3201 #endif 3202 #ifdef CONFIG_FAULT_INJECTION 3203 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3204 #endif 3205 #ifdef CONFIG_TASK_IO_ACCOUNTING 3206 INF("io", S_IRUGO, proc_tid_io_accounting), 3207 #endif 3208 }; 3209 3210 static int proc_tid_base_readdir(struct file * filp, 3211 void * dirent, filldir_t filldir) 3212 { 3213 return proc_pident_readdir(filp,dirent,filldir, 3214 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 3215 } 3216 3217 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 3218 return proc_pident_lookup(dir, dentry, 3219 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3220 } 3221 3222 static const struct file_operations proc_tid_base_operations = { 3223 .read = generic_read_dir, 3224 .readdir = proc_tid_base_readdir, 3225 .llseek = default_llseek, 3226 }; 3227 3228 static const struct inode_operations proc_tid_base_inode_operations = { 3229 .lookup = proc_tid_base_lookup, 3230 .getattr = pid_getattr, 3231 .setattr = proc_setattr, 3232 }; 3233 3234 static struct dentry *proc_task_instantiate(struct inode *dir, 3235 struct dentry *dentry, struct task_struct *task, const void *ptr) 3236 { 3237 struct dentry *error = ERR_PTR(-ENOENT); 3238 struct inode *inode; 3239 inode = proc_pid_make_inode(dir->i_sb, task); 3240 3241 if (!inode) 3242 goto out; 3243 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3244 inode->i_op = &proc_tid_base_inode_operations; 3245 inode->i_fop = &proc_tid_base_operations; 3246 inode->i_flags|=S_IMMUTABLE; 3247 3248 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff, 3249 ARRAY_SIZE(tid_base_stuff)); 3250 3251 dentry->d_op = &pid_dentry_operations; 3252 3253 d_add(dentry, inode); 3254 /* Close the race of the process dying before we return the dentry */ 3255 if (pid_revalidate(dentry, NULL)) 3256 error = NULL; 3257 out: 3258 return error; 3259 } 3260 3261 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 3262 { 3263 struct dentry *result = ERR_PTR(-ENOENT); 3264 struct task_struct *task; 3265 struct task_struct *leader = get_proc_task(dir); 3266 unsigned tid; 3267 struct pid_namespace *ns; 3268 3269 if (!leader) 3270 goto out_no_task; 3271 3272 tid = name_to_int(dentry); 3273 if (tid == ~0U) 3274 goto out; 3275 3276 ns = dentry->d_sb->s_fs_info; 3277 rcu_read_lock(); 3278 task = find_task_by_pid_ns(tid, ns); 3279 if (task) 3280 get_task_struct(task); 3281 rcu_read_unlock(); 3282 if (!task) 3283 goto out; 3284 if (!same_thread_group(leader, task)) 3285 goto out_drop_task; 3286 3287 result = proc_task_instantiate(dir, dentry, task, NULL); 3288 out_drop_task: 3289 put_task_struct(task); 3290 out: 3291 put_task_struct(leader); 3292 out_no_task: 3293 return result; 3294 } 3295 3296 /* 3297 * Find the first tid of a thread group to return to user space. 3298 * 3299 * Usually this is just the thread group leader, but if the users 3300 * buffer was too small or there was a seek into the middle of the 3301 * directory we have more work todo. 3302 * 3303 * In the case of a short read we start with find_task_by_pid. 3304 * 3305 * In the case of a seek we start with the leader and walk nr 3306 * threads past it. 3307 */ 3308 static struct task_struct *first_tid(struct task_struct *leader, 3309 int tid, int nr, struct pid_namespace *ns) 3310 { 3311 struct task_struct *pos; 3312 3313 rcu_read_lock(); 3314 /* Attempt to start with the pid of a thread */ 3315 if (tid && (nr > 0)) { 3316 pos = find_task_by_pid_ns(tid, ns); 3317 if (pos && (pos->group_leader == leader)) 3318 goto found; 3319 } 3320 3321 /* If nr exceeds the number of threads there is nothing todo */ 3322 pos = NULL; 3323 if (nr && nr >= get_nr_threads(leader)) 3324 goto out; 3325 3326 /* If we haven't found our starting place yet start 3327 * with the leader and walk nr threads forward. 3328 */ 3329 for (pos = leader; nr > 0; --nr) { 3330 pos = next_thread(pos); 3331 if (pos == leader) { 3332 pos = NULL; 3333 goto out; 3334 } 3335 } 3336 found: 3337 get_task_struct(pos); 3338 out: 3339 rcu_read_unlock(); 3340 return pos; 3341 } 3342 3343 /* 3344 * Find the next thread in the thread list. 3345 * Return NULL if there is an error or no next thread. 3346 * 3347 * The reference to the input task_struct is released. 3348 */ 3349 static struct task_struct *next_tid(struct task_struct *start) 3350 { 3351 struct task_struct *pos = NULL; 3352 rcu_read_lock(); 3353 if (pid_alive(start)) { 3354 pos = next_thread(start); 3355 if (thread_group_leader(pos)) 3356 pos = NULL; 3357 else 3358 get_task_struct(pos); 3359 } 3360 rcu_read_unlock(); 3361 put_task_struct(start); 3362 return pos; 3363 } 3364 3365 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3366 struct task_struct *task, int tid) 3367 { 3368 char name[PROC_NUMBUF]; 3369 int len = snprintf(name, sizeof(name), "%d", tid); 3370 return proc_fill_cache(filp, dirent, filldir, name, len, 3371 proc_task_instantiate, task, NULL); 3372 } 3373 3374 /* for the /proc/TGID/task/ directories */ 3375 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 3376 { 3377 struct dentry *dentry = filp->f_path.dentry; 3378 struct inode *inode = dentry->d_inode; 3379 struct task_struct *leader = NULL; 3380 struct task_struct *task; 3381 int retval = -ENOENT; 3382 ino_t ino; 3383 int tid; 3384 struct pid_namespace *ns; 3385 3386 task = get_proc_task(inode); 3387 if (!task) 3388 goto out_no_task; 3389 rcu_read_lock(); 3390 if (pid_alive(task)) { 3391 leader = task->group_leader; 3392 get_task_struct(leader); 3393 } 3394 rcu_read_unlock(); 3395 put_task_struct(task); 3396 if (!leader) 3397 goto out_no_task; 3398 retval = 0; 3399 3400 switch ((unsigned long)filp->f_pos) { 3401 case 0: 3402 ino = inode->i_ino; 3403 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0) 3404 goto out; 3405 filp->f_pos++; 3406 /* fall through */ 3407 case 1: 3408 ino = parent_ino(dentry); 3409 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0) 3410 goto out; 3411 filp->f_pos++; 3412 /* fall through */ 3413 } 3414 3415 /* f_version caches the tgid value that the last readdir call couldn't 3416 * return. lseek aka telldir automagically resets f_version to 0. 3417 */ 3418 ns = filp->f_dentry->d_sb->s_fs_info; 3419 tid = (int)filp->f_version; 3420 filp->f_version = 0; 3421 for (task = first_tid(leader, tid, filp->f_pos - 2, ns); 3422 task; 3423 task = next_tid(task), filp->f_pos++) { 3424 tid = task_pid_nr_ns(task, ns); 3425 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 3426 /* returning this tgid failed, save it as the first 3427 * pid for the next readir call */ 3428 filp->f_version = (u64)tid; 3429 put_task_struct(task); 3430 break; 3431 } 3432 } 3433 out: 3434 put_task_struct(leader); 3435 out_no_task: 3436 return retval; 3437 } 3438 3439 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3440 { 3441 struct inode *inode = dentry->d_inode; 3442 struct task_struct *p = get_proc_task(inode); 3443 generic_fillattr(inode, stat); 3444 3445 if (p) { 3446 stat->nlink += get_nr_threads(p); 3447 put_task_struct(p); 3448 } 3449 3450 return 0; 3451 } 3452 3453 static const struct inode_operations proc_task_inode_operations = { 3454 .lookup = proc_task_lookup, 3455 .getattr = proc_task_getattr, 3456 .setattr = proc_setattr, 3457 }; 3458 3459 static const struct file_operations proc_task_operations = { 3460 .read = generic_read_dir, 3461 .readdir = proc_task_readdir, 3462 .llseek = default_llseek, 3463 }; 3464