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; 1799 struct task_struct *task; 1800 const struct cred *cred; 1801 1802 if (nd && nd->flags & LOOKUP_RCU) 1803 return -ECHILD; 1804 1805 inode = dentry->d_inode; 1806 task = get_proc_task(inode); 1807 1808 if (task) { 1809 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1810 task_dumpable(task)) { 1811 rcu_read_lock(); 1812 cred = __task_cred(task); 1813 inode->i_uid = cred->euid; 1814 inode->i_gid = cred->egid; 1815 rcu_read_unlock(); 1816 } else { 1817 inode->i_uid = 0; 1818 inode->i_gid = 0; 1819 } 1820 inode->i_mode &= ~(S_ISUID | S_ISGID); 1821 security_task_to_inode(task, inode); 1822 put_task_struct(task); 1823 return 1; 1824 } 1825 d_drop(dentry); 1826 return 0; 1827 } 1828 1829 static int pid_delete_dentry(const struct dentry * dentry) 1830 { 1831 /* Is the task we represent dead? 1832 * If so, then don't put the dentry on the lru list, 1833 * kill it immediately. 1834 */ 1835 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1836 } 1837 1838 static const struct dentry_operations pid_dentry_operations = 1839 { 1840 .d_revalidate = pid_revalidate, 1841 .d_delete = pid_delete_dentry, 1842 }; 1843 1844 /* Lookups */ 1845 1846 typedef struct dentry *instantiate_t(struct inode *, struct dentry *, 1847 struct task_struct *, const void *); 1848 1849 /* 1850 * Fill a directory entry. 1851 * 1852 * If possible create the dcache entry and derive our inode number and 1853 * file type from dcache entry. 1854 * 1855 * Since all of the proc inode numbers are dynamically generated, the inode 1856 * numbers do not exist until the inode is cache. This means creating the 1857 * the dcache entry in readdir is necessary to keep the inode numbers 1858 * reported by readdir in sync with the inode numbers reported 1859 * by stat. 1860 */ 1861 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1862 char *name, int len, 1863 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1864 { 1865 struct dentry *child, *dir = filp->f_path.dentry; 1866 struct inode *inode; 1867 struct qstr qname; 1868 ino_t ino = 0; 1869 unsigned type = DT_UNKNOWN; 1870 1871 qname.name = name; 1872 qname.len = len; 1873 qname.hash = full_name_hash(name, len); 1874 1875 child = d_lookup(dir, &qname); 1876 if (!child) { 1877 struct dentry *new; 1878 new = d_alloc(dir, &qname); 1879 if (new) { 1880 child = instantiate(dir->d_inode, new, task, ptr); 1881 if (child) 1882 dput(new); 1883 else 1884 child = new; 1885 } 1886 } 1887 if (!child || IS_ERR(child) || !child->d_inode) 1888 goto end_instantiate; 1889 inode = child->d_inode; 1890 if (inode) { 1891 ino = inode->i_ino; 1892 type = inode->i_mode >> 12; 1893 } 1894 dput(child); 1895 end_instantiate: 1896 if (!ino) 1897 ino = find_inode_number(dir, &qname); 1898 if (!ino) 1899 ino = 1; 1900 return filldir(dirent, name, len, filp->f_pos, ino, type); 1901 } 1902 1903 static unsigned name_to_int(struct dentry *dentry) 1904 { 1905 const char *name = dentry->d_name.name; 1906 int len = dentry->d_name.len; 1907 unsigned n = 0; 1908 1909 if (len > 1 && *name == '0') 1910 goto out; 1911 while (len-- > 0) { 1912 unsigned c = *name++ - '0'; 1913 if (c > 9) 1914 goto out; 1915 if (n >= (~0U-9)/10) 1916 goto out; 1917 n *= 10; 1918 n += c; 1919 } 1920 return n; 1921 out: 1922 return ~0U; 1923 } 1924 1925 #define PROC_FDINFO_MAX 64 1926 1927 static int proc_fd_info(struct inode *inode, struct path *path, char *info) 1928 { 1929 struct task_struct *task = get_proc_task(inode); 1930 struct files_struct *files = NULL; 1931 struct file *file; 1932 int fd = proc_fd(inode); 1933 1934 if (task) { 1935 files = get_files_struct(task); 1936 put_task_struct(task); 1937 } 1938 if (files) { 1939 /* 1940 * We are not taking a ref to the file structure, so we must 1941 * hold ->file_lock. 1942 */ 1943 spin_lock(&files->file_lock); 1944 file = fcheck_files(files, fd); 1945 if (file) { 1946 if (path) { 1947 *path = file->f_path; 1948 path_get(&file->f_path); 1949 } 1950 if (info) 1951 snprintf(info, PROC_FDINFO_MAX, 1952 "pos:\t%lli\n" 1953 "flags:\t0%o\n", 1954 (long long) file->f_pos, 1955 file->f_flags); 1956 spin_unlock(&files->file_lock); 1957 put_files_struct(files); 1958 return 0; 1959 } 1960 spin_unlock(&files->file_lock); 1961 put_files_struct(files); 1962 } 1963 return -ENOENT; 1964 } 1965 1966 static int proc_fd_link(struct inode *inode, struct path *path) 1967 { 1968 return proc_fd_info(inode, path, NULL); 1969 } 1970 1971 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1972 { 1973 struct inode *inode; 1974 struct task_struct *task; 1975 int fd; 1976 struct files_struct *files; 1977 const struct cred *cred; 1978 1979 if (nd && nd->flags & LOOKUP_RCU) 1980 return -ECHILD; 1981 1982 inode = dentry->d_inode; 1983 task = get_proc_task(inode); 1984 fd = proc_fd(inode); 1985 1986 if (task) { 1987 files = get_files_struct(task); 1988 if (files) { 1989 rcu_read_lock(); 1990 if (fcheck_files(files, fd)) { 1991 rcu_read_unlock(); 1992 put_files_struct(files); 1993 if (task_dumpable(task)) { 1994 rcu_read_lock(); 1995 cred = __task_cred(task); 1996 inode->i_uid = cred->euid; 1997 inode->i_gid = cred->egid; 1998 rcu_read_unlock(); 1999 } else { 2000 inode->i_uid = 0; 2001 inode->i_gid = 0; 2002 } 2003 inode->i_mode &= ~(S_ISUID | S_ISGID); 2004 security_task_to_inode(task, inode); 2005 put_task_struct(task); 2006 return 1; 2007 } 2008 rcu_read_unlock(); 2009 put_files_struct(files); 2010 } 2011 put_task_struct(task); 2012 } 2013 d_drop(dentry); 2014 return 0; 2015 } 2016 2017 static const struct dentry_operations tid_fd_dentry_operations = 2018 { 2019 .d_revalidate = tid_fd_revalidate, 2020 .d_delete = pid_delete_dentry, 2021 }; 2022 2023 static struct dentry *proc_fd_instantiate(struct inode *dir, 2024 struct dentry *dentry, struct task_struct *task, const void *ptr) 2025 { 2026 unsigned fd = *(const unsigned *)ptr; 2027 struct file *file; 2028 struct files_struct *files; 2029 struct inode *inode; 2030 struct proc_inode *ei; 2031 struct dentry *error = ERR_PTR(-ENOENT); 2032 2033 inode = proc_pid_make_inode(dir->i_sb, task); 2034 if (!inode) 2035 goto out; 2036 ei = PROC_I(inode); 2037 ei->fd = fd; 2038 files = get_files_struct(task); 2039 if (!files) 2040 goto out_iput; 2041 inode->i_mode = S_IFLNK; 2042 2043 /* 2044 * We are not taking a ref to the file structure, so we must 2045 * hold ->file_lock. 2046 */ 2047 spin_lock(&files->file_lock); 2048 file = fcheck_files(files, fd); 2049 if (!file) 2050 goto out_unlock; 2051 if (file->f_mode & FMODE_READ) 2052 inode->i_mode |= S_IRUSR | S_IXUSR; 2053 if (file->f_mode & FMODE_WRITE) 2054 inode->i_mode |= S_IWUSR | S_IXUSR; 2055 spin_unlock(&files->file_lock); 2056 put_files_struct(files); 2057 2058 inode->i_op = &proc_pid_link_inode_operations; 2059 inode->i_size = 64; 2060 ei->op.proc_get_link = proc_fd_link; 2061 d_set_d_op(dentry, &tid_fd_dentry_operations); 2062 d_add(dentry, inode); 2063 /* Close the race of the process dying before we return the dentry */ 2064 if (tid_fd_revalidate(dentry, NULL)) 2065 error = NULL; 2066 2067 out: 2068 return error; 2069 out_unlock: 2070 spin_unlock(&files->file_lock); 2071 put_files_struct(files); 2072 out_iput: 2073 iput(inode); 2074 goto out; 2075 } 2076 2077 static struct dentry *proc_lookupfd_common(struct inode *dir, 2078 struct dentry *dentry, 2079 instantiate_t instantiate) 2080 { 2081 struct task_struct *task = get_proc_task(dir); 2082 unsigned fd = name_to_int(dentry); 2083 struct dentry *result = ERR_PTR(-ENOENT); 2084 2085 if (!task) 2086 goto out_no_task; 2087 if (fd == ~0U) 2088 goto out; 2089 2090 result = instantiate(dir, dentry, task, &fd); 2091 out: 2092 put_task_struct(task); 2093 out_no_task: 2094 return result; 2095 } 2096 2097 static int proc_readfd_common(struct file * filp, void * dirent, 2098 filldir_t filldir, instantiate_t instantiate) 2099 { 2100 struct dentry *dentry = filp->f_path.dentry; 2101 struct inode *inode = dentry->d_inode; 2102 struct task_struct *p = get_proc_task(inode); 2103 unsigned int fd, ino; 2104 int retval; 2105 struct files_struct * files; 2106 2107 retval = -ENOENT; 2108 if (!p) 2109 goto out_no_task; 2110 retval = 0; 2111 2112 fd = filp->f_pos; 2113 switch (fd) { 2114 case 0: 2115 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 2116 goto out; 2117 filp->f_pos++; 2118 case 1: 2119 ino = parent_ino(dentry); 2120 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 2121 goto out; 2122 filp->f_pos++; 2123 default: 2124 files = get_files_struct(p); 2125 if (!files) 2126 goto out; 2127 rcu_read_lock(); 2128 for (fd = filp->f_pos-2; 2129 fd < files_fdtable(files)->max_fds; 2130 fd++, filp->f_pos++) { 2131 char name[PROC_NUMBUF]; 2132 int len; 2133 2134 if (!fcheck_files(files, fd)) 2135 continue; 2136 rcu_read_unlock(); 2137 2138 len = snprintf(name, sizeof(name), "%d", fd); 2139 if (proc_fill_cache(filp, dirent, filldir, 2140 name, len, instantiate, 2141 p, &fd) < 0) { 2142 rcu_read_lock(); 2143 break; 2144 } 2145 rcu_read_lock(); 2146 } 2147 rcu_read_unlock(); 2148 put_files_struct(files); 2149 } 2150 out: 2151 put_task_struct(p); 2152 out_no_task: 2153 return retval; 2154 } 2155 2156 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 2157 struct nameidata *nd) 2158 { 2159 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 2160 } 2161 2162 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 2163 { 2164 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 2165 } 2166 2167 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 2168 size_t len, loff_t *ppos) 2169 { 2170 char tmp[PROC_FDINFO_MAX]; 2171 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); 2172 if (!err) 2173 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 2174 return err; 2175 } 2176 2177 static const struct file_operations proc_fdinfo_file_operations = { 2178 .open = nonseekable_open, 2179 .read = proc_fdinfo_read, 2180 .llseek = no_llseek, 2181 }; 2182 2183 static const struct file_operations proc_fd_operations = { 2184 .read = generic_read_dir, 2185 .readdir = proc_readfd, 2186 .llseek = default_llseek, 2187 }; 2188 2189 /* 2190 * /proc/pid/fd needs a special permission handler so that a process can still 2191 * access /proc/self/fd after it has executed a setuid(). 2192 */ 2193 static int proc_fd_permission(struct inode *inode, int mask, unsigned int flags) 2194 { 2195 int rv; 2196 2197 if (flags & IPERM_FLAG_RCU) 2198 return -ECHILD; 2199 rv = generic_permission(inode, mask, flags, NULL); 2200 if (rv == 0) 2201 return 0; 2202 if (task_pid(current) == proc_pid(inode)) 2203 rv = 0; 2204 return rv; 2205 } 2206 2207 /* 2208 * proc directories can do almost nothing.. 2209 */ 2210 static const struct inode_operations proc_fd_inode_operations = { 2211 .lookup = proc_lookupfd, 2212 .permission = proc_fd_permission, 2213 .setattr = proc_setattr, 2214 }; 2215 2216 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 2217 struct dentry *dentry, struct task_struct *task, const void *ptr) 2218 { 2219 unsigned fd = *(unsigned *)ptr; 2220 struct inode *inode; 2221 struct proc_inode *ei; 2222 struct dentry *error = ERR_PTR(-ENOENT); 2223 2224 inode = proc_pid_make_inode(dir->i_sb, task); 2225 if (!inode) 2226 goto out; 2227 ei = PROC_I(inode); 2228 ei->fd = fd; 2229 inode->i_mode = S_IFREG | S_IRUSR; 2230 inode->i_fop = &proc_fdinfo_file_operations; 2231 d_set_d_op(dentry, &tid_fd_dentry_operations); 2232 d_add(dentry, inode); 2233 /* Close the race of the process dying before we return the dentry */ 2234 if (tid_fd_revalidate(dentry, NULL)) 2235 error = NULL; 2236 2237 out: 2238 return error; 2239 } 2240 2241 static struct dentry *proc_lookupfdinfo(struct inode *dir, 2242 struct dentry *dentry, 2243 struct nameidata *nd) 2244 { 2245 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 2246 } 2247 2248 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 2249 { 2250 return proc_readfd_common(filp, dirent, filldir, 2251 proc_fdinfo_instantiate); 2252 } 2253 2254 static const struct file_operations proc_fdinfo_operations = { 2255 .read = generic_read_dir, 2256 .readdir = proc_readfdinfo, 2257 .llseek = default_llseek, 2258 }; 2259 2260 /* 2261 * proc directories can do almost nothing.. 2262 */ 2263 static const struct inode_operations proc_fdinfo_inode_operations = { 2264 .lookup = proc_lookupfdinfo, 2265 .setattr = proc_setattr, 2266 }; 2267 2268 2269 static struct dentry *proc_pident_instantiate(struct inode *dir, 2270 struct dentry *dentry, struct task_struct *task, const void *ptr) 2271 { 2272 const struct pid_entry *p = ptr; 2273 struct inode *inode; 2274 struct proc_inode *ei; 2275 struct dentry *error = ERR_PTR(-ENOENT); 2276 2277 inode = proc_pid_make_inode(dir->i_sb, task); 2278 if (!inode) 2279 goto out; 2280 2281 ei = PROC_I(inode); 2282 inode->i_mode = p->mode; 2283 if (S_ISDIR(inode->i_mode)) 2284 inode->i_nlink = 2; /* Use getattr to fix if necessary */ 2285 if (p->iop) 2286 inode->i_op = p->iop; 2287 if (p->fop) 2288 inode->i_fop = p->fop; 2289 ei->op = p->op; 2290 d_set_d_op(dentry, &pid_dentry_operations); 2291 d_add(dentry, inode); 2292 /* Close the race of the process dying before we return the dentry */ 2293 if (pid_revalidate(dentry, NULL)) 2294 error = NULL; 2295 out: 2296 return error; 2297 } 2298 2299 static struct dentry *proc_pident_lookup(struct inode *dir, 2300 struct dentry *dentry, 2301 const struct pid_entry *ents, 2302 unsigned int nents) 2303 { 2304 struct dentry *error; 2305 struct task_struct *task = get_proc_task(dir); 2306 const struct pid_entry *p, *last; 2307 2308 error = ERR_PTR(-ENOENT); 2309 2310 if (!task) 2311 goto out_no_task; 2312 2313 /* 2314 * Yes, it does not scale. And it should not. Don't add 2315 * new entries into /proc/<tgid>/ without very good reasons. 2316 */ 2317 last = &ents[nents - 1]; 2318 for (p = ents; p <= last; p++) { 2319 if (p->len != dentry->d_name.len) 2320 continue; 2321 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2322 break; 2323 } 2324 if (p > last) 2325 goto out; 2326 2327 error = proc_pident_instantiate(dir, dentry, task, p); 2328 out: 2329 put_task_struct(task); 2330 out_no_task: 2331 return error; 2332 } 2333 2334 static int proc_pident_fill_cache(struct file *filp, void *dirent, 2335 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2336 { 2337 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2338 proc_pident_instantiate, task, p); 2339 } 2340 2341 static int proc_pident_readdir(struct file *filp, 2342 void *dirent, filldir_t filldir, 2343 const struct pid_entry *ents, unsigned int nents) 2344 { 2345 int i; 2346 struct dentry *dentry = filp->f_path.dentry; 2347 struct inode *inode = dentry->d_inode; 2348 struct task_struct *task = get_proc_task(inode); 2349 const struct pid_entry *p, *last; 2350 ino_t ino; 2351 int ret; 2352 2353 ret = -ENOENT; 2354 if (!task) 2355 goto out_no_task; 2356 2357 ret = 0; 2358 i = filp->f_pos; 2359 switch (i) { 2360 case 0: 2361 ino = inode->i_ino; 2362 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 2363 goto out; 2364 i++; 2365 filp->f_pos++; 2366 /* fall through */ 2367 case 1: 2368 ino = parent_ino(dentry); 2369 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 2370 goto out; 2371 i++; 2372 filp->f_pos++; 2373 /* fall through */ 2374 default: 2375 i -= 2; 2376 if (i >= nents) { 2377 ret = 1; 2378 goto out; 2379 } 2380 p = ents + i; 2381 last = &ents[nents - 1]; 2382 while (p <= last) { 2383 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2384 goto out; 2385 filp->f_pos++; 2386 p++; 2387 } 2388 } 2389 2390 ret = 1; 2391 out: 2392 put_task_struct(task); 2393 out_no_task: 2394 return ret; 2395 } 2396 2397 #ifdef CONFIG_SECURITY 2398 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2399 size_t count, loff_t *ppos) 2400 { 2401 struct inode * inode = file->f_path.dentry->d_inode; 2402 char *p = NULL; 2403 ssize_t length; 2404 struct task_struct *task = get_proc_task(inode); 2405 2406 if (!task) 2407 return -ESRCH; 2408 2409 length = security_getprocattr(task, 2410 (char*)file->f_path.dentry->d_name.name, 2411 &p); 2412 put_task_struct(task); 2413 if (length > 0) 2414 length = simple_read_from_buffer(buf, count, ppos, p, length); 2415 kfree(p); 2416 return length; 2417 } 2418 2419 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2420 size_t count, loff_t *ppos) 2421 { 2422 struct inode * inode = file->f_path.dentry->d_inode; 2423 char *page; 2424 ssize_t length; 2425 struct task_struct *task = get_proc_task(inode); 2426 2427 length = -ESRCH; 2428 if (!task) 2429 goto out_no_task; 2430 if (count > PAGE_SIZE) 2431 count = PAGE_SIZE; 2432 2433 /* No partial writes. */ 2434 length = -EINVAL; 2435 if (*ppos != 0) 2436 goto out; 2437 2438 length = -ENOMEM; 2439 page = (char*)__get_free_page(GFP_TEMPORARY); 2440 if (!page) 2441 goto out; 2442 2443 length = -EFAULT; 2444 if (copy_from_user(page, buf, count)) 2445 goto out_free; 2446 2447 /* Guard against adverse ptrace interaction */ 2448 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex); 2449 if (length < 0) 2450 goto out_free; 2451 2452 length = security_setprocattr(task, 2453 (char*)file->f_path.dentry->d_name.name, 2454 (void*)page, count); 2455 mutex_unlock(&task->signal->cred_guard_mutex); 2456 out_free: 2457 free_page((unsigned long) page); 2458 out: 2459 put_task_struct(task); 2460 out_no_task: 2461 return length; 2462 } 2463 2464 static const struct file_operations proc_pid_attr_operations = { 2465 .read = proc_pid_attr_read, 2466 .write = proc_pid_attr_write, 2467 .llseek = generic_file_llseek, 2468 }; 2469 2470 static const struct pid_entry attr_dir_stuff[] = { 2471 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2472 REG("prev", S_IRUGO, proc_pid_attr_operations), 2473 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2474 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2475 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2476 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2477 }; 2478 2479 static int proc_attr_dir_readdir(struct file * filp, 2480 void * dirent, filldir_t filldir) 2481 { 2482 return proc_pident_readdir(filp,dirent,filldir, 2483 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2484 } 2485 2486 static const struct file_operations proc_attr_dir_operations = { 2487 .read = generic_read_dir, 2488 .readdir = proc_attr_dir_readdir, 2489 .llseek = default_llseek, 2490 }; 2491 2492 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2493 struct dentry *dentry, struct nameidata *nd) 2494 { 2495 return proc_pident_lookup(dir, dentry, 2496 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2497 } 2498 2499 static const struct inode_operations proc_attr_dir_inode_operations = { 2500 .lookup = proc_attr_dir_lookup, 2501 .getattr = pid_getattr, 2502 .setattr = proc_setattr, 2503 }; 2504 2505 #endif 2506 2507 #ifdef CONFIG_ELF_CORE 2508 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2509 size_t count, loff_t *ppos) 2510 { 2511 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2512 struct mm_struct *mm; 2513 char buffer[PROC_NUMBUF]; 2514 size_t len; 2515 int ret; 2516 2517 if (!task) 2518 return -ESRCH; 2519 2520 ret = 0; 2521 mm = get_task_mm(task); 2522 if (mm) { 2523 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2524 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2525 MMF_DUMP_FILTER_SHIFT)); 2526 mmput(mm); 2527 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2528 } 2529 2530 put_task_struct(task); 2531 2532 return ret; 2533 } 2534 2535 static ssize_t proc_coredump_filter_write(struct file *file, 2536 const char __user *buf, 2537 size_t count, 2538 loff_t *ppos) 2539 { 2540 struct task_struct *task; 2541 struct mm_struct *mm; 2542 char buffer[PROC_NUMBUF], *end; 2543 unsigned int val; 2544 int ret; 2545 int i; 2546 unsigned long mask; 2547 2548 ret = -EFAULT; 2549 memset(buffer, 0, sizeof(buffer)); 2550 if (count > sizeof(buffer) - 1) 2551 count = sizeof(buffer) - 1; 2552 if (copy_from_user(buffer, buf, count)) 2553 goto out_no_task; 2554 2555 ret = -EINVAL; 2556 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2557 if (*end == '\n') 2558 end++; 2559 if (end - buffer == 0) 2560 goto out_no_task; 2561 2562 ret = -ESRCH; 2563 task = get_proc_task(file->f_dentry->d_inode); 2564 if (!task) 2565 goto out_no_task; 2566 2567 ret = end - buffer; 2568 mm = get_task_mm(task); 2569 if (!mm) 2570 goto out_no_mm; 2571 2572 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2573 if (val & mask) 2574 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2575 else 2576 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2577 } 2578 2579 mmput(mm); 2580 out_no_mm: 2581 put_task_struct(task); 2582 out_no_task: 2583 return ret; 2584 } 2585 2586 static const struct file_operations proc_coredump_filter_operations = { 2587 .read = proc_coredump_filter_read, 2588 .write = proc_coredump_filter_write, 2589 .llseek = generic_file_llseek, 2590 }; 2591 #endif 2592 2593 /* 2594 * /proc/self: 2595 */ 2596 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2597 int buflen) 2598 { 2599 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2600 pid_t tgid = task_tgid_nr_ns(current, ns); 2601 char tmp[PROC_NUMBUF]; 2602 if (!tgid) 2603 return -ENOENT; 2604 sprintf(tmp, "%d", tgid); 2605 return vfs_readlink(dentry,buffer,buflen,tmp); 2606 } 2607 2608 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2609 { 2610 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2611 pid_t tgid = task_tgid_nr_ns(current, ns); 2612 char *name = ERR_PTR(-ENOENT); 2613 if (tgid) { 2614 name = __getname(); 2615 if (!name) 2616 name = ERR_PTR(-ENOMEM); 2617 else 2618 sprintf(name, "%d", tgid); 2619 } 2620 nd_set_link(nd, name); 2621 return NULL; 2622 } 2623 2624 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd, 2625 void *cookie) 2626 { 2627 char *s = nd_get_link(nd); 2628 if (!IS_ERR(s)) 2629 __putname(s); 2630 } 2631 2632 static const struct inode_operations proc_self_inode_operations = { 2633 .readlink = proc_self_readlink, 2634 .follow_link = proc_self_follow_link, 2635 .put_link = proc_self_put_link, 2636 }; 2637 2638 /* 2639 * proc base 2640 * 2641 * These are the directory entries in the root directory of /proc 2642 * that properly belong to the /proc filesystem, as they describe 2643 * describe something that is process related. 2644 */ 2645 static const struct pid_entry proc_base_stuff[] = { 2646 NOD("self", S_IFLNK|S_IRWXUGO, 2647 &proc_self_inode_operations, NULL, {}), 2648 }; 2649 2650 /* 2651 * Exceptional case: normally we are not allowed to unhash a busy 2652 * directory. In this case, however, we can do it - no aliasing problems 2653 * due to the way we treat inodes. 2654 */ 2655 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) 2656 { 2657 struct inode *inode; 2658 struct task_struct *task; 2659 2660 if (nd->flags & LOOKUP_RCU) 2661 return -ECHILD; 2662 2663 inode = dentry->d_inode; 2664 task = get_proc_task(inode); 2665 if (task) { 2666 put_task_struct(task); 2667 return 1; 2668 } 2669 d_drop(dentry); 2670 return 0; 2671 } 2672 2673 static const struct dentry_operations proc_base_dentry_operations = 2674 { 2675 .d_revalidate = proc_base_revalidate, 2676 .d_delete = pid_delete_dentry, 2677 }; 2678 2679 static struct dentry *proc_base_instantiate(struct inode *dir, 2680 struct dentry *dentry, struct task_struct *task, const void *ptr) 2681 { 2682 const struct pid_entry *p = ptr; 2683 struct inode *inode; 2684 struct proc_inode *ei; 2685 struct dentry *error; 2686 2687 /* Allocate the inode */ 2688 error = ERR_PTR(-ENOMEM); 2689 inode = new_inode(dir->i_sb); 2690 if (!inode) 2691 goto out; 2692 2693 /* Initialize the inode */ 2694 ei = PROC_I(inode); 2695 inode->i_ino = get_next_ino(); 2696 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2697 2698 /* 2699 * grab the reference to the task. 2700 */ 2701 ei->pid = get_task_pid(task, PIDTYPE_PID); 2702 if (!ei->pid) 2703 goto out_iput; 2704 2705 inode->i_mode = p->mode; 2706 if (S_ISDIR(inode->i_mode)) 2707 inode->i_nlink = 2; 2708 if (S_ISLNK(inode->i_mode)) 2709 inode->i_size = 64; 2710 if (p->iop) 2711 inode->i_op = p->iop; 2712 if (p->fop) 2713 inode->i_fop = p->fop; 2714 ei->op = p->op; 2715 d_set_d_op(dentry, &proc_base_dentry_operations); 2716 d_add(dentry, inode); 2717 error = NULL; 2718 out: 2719 return error; 2720 out_iput: 2721 iput(inode); 2722 goto out; 2723 } 2724 2725 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2726 { 2727 struct dentry *error; 2728 struct task_struct *task = get_proc_task(dir); 2729 const struct pid_entry *p, *last; 2730 2731 error = ERR_PTR(-ENOENT); 2732 2733 if (!task) 2734 goto out_no_task; 2735 2736 /* Lookup the directory entry */ 2737 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2738 for (p = proc_base_stuff; p <= last; p++) { 2739 if (p->len != dentry->d_name.len) 2740 continue; 2741 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2742 break; 2743 } 2744 if (p > last) 2745 goto out; 2746 2747 error = proc_base_instantiate(dir, dentry, task, p); 2748 2749 out: 2750 put_task_struct(task); 2751 out_no_task: 2752 return error; 2753 } 2754 2755 static int proc_base_fill_cache(struct file *filp, void *dirent, 2756 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2757 { 2758 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2759 proc_base_instantiate, task, p); 2760 } 2761 2762 #ifdef CONFIG_TASK_IO_ACCOUNTING 2763 static int do_io_accounting(struct task_struct *task, char *buffer, int whole) 2764 { 2765 struct task_io_accounting acct = task->ioac; 2766 unsigned long flags; 2767 2768 if (whole && lock_task_sighand(task, &flags)) { 2769 struct task_struct *t = task; 2770 2771 task_io_accounting_add(&acct, &task->signal->ioac); 2772 while_each_thread(task, t) 2773 task_io_accounting_add(&acct, &t->ioac); 2774 2775 unlock_task_sighand(task, &flags); 2776 } 2777 return sprintf(buffer, 2778 "rchar: %llu\n" 2779 "wchar: %llu\n" 2780 "syscr: %llu\n" 2781 "syscw: %llu\n" 2782 "read_bytes: %llu\n" 2783 "write_bytes: %llu\n" 2784 "cancelled_write_bytes: %llu\n", 2785 (unsigned long long)acct.rchar, 2786 (unsigned long long)acct.wchar, 2787 (unsigned long long)acct.syscr, 2788 (unsigned long long)acct.syscw, 2789 (unsigned long long)acct.read_bytes, 2790 (unsigned long long)acct.write_bytes, 2791 (unsigned long long)acct.cancelled_write_bytes); 2792 } 2793 2794 static int proc_tid_io_accounting(struct task_struct *task, char *buffer) 2795 { 2796 return do_io_accounting(task, buffer, 0); 2797 } 2798 2799 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer) 2800 { 2801 return do_io_accounting(task, buffer, 1); 2802 } 2803 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2804 2805 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2806 struct pid *pid, struct task_struct *task) 2807 { 2808 seq_printf(m, "%08x\n", task->personality); 2809 return 0; 2810 } 2811 2812 /* 2813 * Thread groups 2814 */ 2815 static const struct file_operations proc_task_operations; 2816 static const struct inode_operations proc_task_inode_operations; 2817 2818 static const struct pid_entry tgid_base_stuff[] = { 2819 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2820 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2821 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2822 #ifdef CONFIG_NET 2823 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2824 #endif 2825 REG("environ", S_IRUSR, proc_environ_operations), 2826 INF("auxv", S_IRUSR, proc_pid_auxv), 2827 ONE("status", S_IRUGO, proc_pid_status), 2828 ONE("personality", S_IRUSR, proc_pid_personality), 2829 INF("limits", S_IRUGO, proc_pid_limits), 2830 #ifdef CONFIG_SCHED_DEBUG 2831 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2832 #endif 2833 #ifdef CONFIG_SCHED_AUTOGROUP 2834 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2835 #endif 2836 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2837 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2838 INF("syscall", S_IRUSR, proc_pid_syscall), 2839 #endif 2840 INF("cmdline", S_IRUGO, proc_pid_cmdline), 2841 ONE("stat", S_IRUGO, proc_tgid_stat), 2842 ONE("statm", S_IRUGO, proc_pid_statm), 2843 REG("maps", S_IRUGO, proc_maps_operations), 2844 #ifdef CONFIG_NUMA 2845 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 2846 #endif 2847 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2848 LNK("cwd", proc_cwd_link), 2849 LNK("root", proc_root_link), 2850 LNK("exe", proc_exe_link), 2851 REG("mounts", S_IRUGO, proc_mounts_operations), 2852 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2853 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2854 #ifdef CONFIG_PROC_PAGE_MONITOR 2855 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2856 REG("smaps", S_IRUGO, proc_smaps_operations), 2857 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2858 #endif 2859 #ifdef CONFIG_SECURITY 2860 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2861 #endif 2862 #ifdef CONFIG_KALLSYMS 2863 INF("wchan", S_IRUGO, proc_pid_wchan), 2864 #endif 2865 #ifdef CONFIG_STACKTRACE 2866 ONE("stack", S_IRUSR, proc_pid_stack), 2867 #endif 2868 #ifdef CONFIG_SCHEDSTATS 2869 INF("schedstat", S_IRUGO, proc_pid_schedstat), 2870 #endif 2871 #ifdef CONFIG_LATENCYTOP 2872 REG("latency", S_IRUGO, proc_lstats_operations), 2873 #endif 2874 #ifdef CONFIG_PROC_PID_CPUSET 2875 REG("cpuset", S_IRUGO, proc_cpuset_operations), 2876 #endif 2877 #ifdef CONFIG_CGROUPS 2878 REG("cgroup", S_IRUGO, proc_cgroup_operations), 2879 #endif 2880 INF("oom_score", S_IRUGO, proc_oom_score), 2881 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 2882 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2883 #ifdef CONFIG_AUDITSYSCALL 2884 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2885 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2886 #endif 2887 #ifdef CONFIG_FAULT_INJECTION 2888 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2889 #endif 2890 #ifdef CONFIG_ELF_CORE 2891 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2892 #endif 2893 #ifdef CONFIG_TASK_IO_ACCOUNTING 2894 INF("io", S_IRUGO, proc_tgid_io_accounting), 2895 #endif 2896 }; 2897 2898 static int proc_tgid_base_readdir(struct file * filp, 2899 void * dirent, filldir_t filldir) 2900 { 2901 return proc_pident_readdir(filp,dirent,filldir, 2902 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2903 } 2904 2905 static const struct file_operations proc_tgid_base_operations = { 2906 .read = generic_read_dir, 2907 .readdir = proc_tgid_base_readdir, 2908 .llseek = default_llseek, 2909 }; 2910 2911 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2912 return proc_pident_lookup(dir, dentry, 2913 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2914 } 2915 2916 static const struct inode_operations proc_tgid_base_inode_operations = { 2917 .lookup = proc_tgid_base_lookup, 2918 .getattr = pid_getattr, 2919 .setattr = proc_setattr, 2920 }; 2921 2922 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2923 { 2924 struct dentry *dentry, *leader, *dir; 2925 char buf[PROC_NUMBUF]; 2926 struct qstr name; 2927 2928 name.name = buf; 2929 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2930 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2931 if (dentry) { 2932 shrink_dcache_parent(dentry); 2933 d_drop(dentry); 2934 dput(dentry); 2935 } 2936 2937 name.name = buf; 2938 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2939 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2940 if (!leader) 2941 goto out; 2942 2943 name.name = "task"; 2944 name.len = strlen(name.name); 2945 dir = d_hash_and_lookup(leader, &name); 2946 if (!dir) 2947 goto out_put_leader; 2948 2949 name.name = buf; 2950 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2951 dentry = d_hash_and_lookup(dir, &name); 2952 if (dentry) { 2953 shrink_dcache_parent(dentry); 2954 d_drop(dentry); 2955 dput(dentry); 2956 } 2957 2958 dput(dir); 2959 out_put_leader: 2960 dput(leader); 2961 out: 2962 return; 2963 } 2964 2965 /** 2966 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2967 * @task: task that should be flushed. 2968 * 2969 * When flushing dentries from proc, one needs to flush them from global 2970 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2971 * in. This call is supposed to do all of this job. 2972 * 2973 * Looks in the dcache for 2974 * /proc/@pid 2975 * /proc/@tgid/task/@pid 2976 * if either directory is present flushes it and all of it'ts children 2977 * from the dcache. 2978 * 2979 * It is safe and reasonable to cache /proc entries for a task until 2980 * that task exits. After that they just clog up the dcache with 2981 * useless entries, possibly causing useful dcache entries to be 2982 * flushed instead. This routine is proved to flush those useless 2983 * dcache entries at process exit time. 2984 * 2985 * NOTE: This routine is just an optimization so it does not guarantee 2986 * that no dcache entries will exist at process exit time it 2987 * just makes it very unlikely that any will persist. 2988 */ 2989 2990 void proc_flush_task(struct task_struct *task) 2991 { 2992 int i; 2993 struct pid *pid, *tgid; 2994 struct upid *upid; 2995 2996 pid = task_pid(task); 2997 tgid = task_tgid(task); 2998 2999 for (i = 0; i <= pid->level; i++) { 3000 upid = &pid->numbers[i]; 3001 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 3002 tgid->numbers[i].nr); 3003 } 3004 3005 upid = &pid->numbers[pid->level]; 3006 if (upid->nr == 1) 3007 pid_ns_release_proc(upid->ns); 3008 } 3009 3010 static struct dentry *proc_pid_instantiate(struct inode *dir, 3011 struct dentry * dentry, 3012 struct task_struct *task, const void *ptr) 3013 { 3014 struct dentry *error = ERR_PTR(-ENOENT); 3015 struct inode *inode; 3016 3017 inode = proc_pid_make_inode(dir->i_sb, task); 3018 if (!inode) 3019 goto out; 3020 3021 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3022 inode->i_op = &proc_tgid_base_inode_operations; 3023 inode->i_fop = &proc_tgid_base_operations; 3024 inode->i_flags|=S_IMMUTABLE; 3025 3026 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff, 3027 ARRAY_SIZE(tgid_base_stuff)); 3028 3029 d_set_d_op(dentry, &pid_dentry_operations); 3030 3031 d_add(dentry, inode); 3032 /* Close the race of the process dying before we return the dentry */ 3033 if (pid_revalidate(dentry, NULL)) 3034 error = NULL; 3035 out: 3036 return error; 3037 } 3038 3039 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 3040 { 3041 struct dentry *result; 3042 struct task_struct *task; 3043 unsigned tgid; 3044 struct pid_namespace *ns; 3045 3046 result = proc_base_lookup(dir, dentry); 3047 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 3048 goto out; 3049 3050 tgid = name_to_int(dentry); 3051 if (tgid == ~0U) 3052 goto out; 3053 3054 ns = dentry->d_sb->s_fs_info; 3055 rcu_read_lock(); 3056 task = find_task_by_pid_ns(tgid, ns); 3057 if (task) 3058 get_task_struct(task); 3059 rcu_read_unlock(); 3060 if (!task) 3061 goto out; 3062 3063 result = proc_pid_instantiate(dir, dentry, task, NULL); 3064 put_task_struct(task); 3065 out: 3066 return result; 3067 } 3068 3069 /* 3070 * Find the first task with tgid >= tgid 3071 * 3072 */ 3073 struct tgid_iter { 3074 unsigned int tgid; 3075 struct task_struct *task; 3076 }; 3077 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 3078 { 3079 struct pid *pid; 3080 3081 if (iter.task) 3082 put_task_struct(iter.task); 3083 rcu_read_lock(); 3084 retry: 3085 iter.task = NULL; 3086 pid = find_ge_pid(iter.tgid, ns); 3087 if (pid) { 3088 iter.tgid = pid_nr_ns(pid, ns); 3089 iter.task = pid_task(pid, PIDTYPE_PID); 3090 /* What we to know is if the pid we have find is the 3091 * pid of a thread_group_leader. Testing for task 3092 * being a thread_group_leader is the obvious thing 3093 * todo but there is a window when it fails, due to 3094 * the pid transfer logic in de_thread. 3095 * 3096 * So we perform the straight forward test of seeing 3097 * if the pid we have found is the pid of a thread 3098 * group leader, and don't worry if the task we have 3099 * found doesn't happen to be a thread group leader. 3100 * As we don't care in the case of readdir. 3101 */ 3102 if (!iter.task || !has_group_leader_pid(iter.task)) { 3103 iter.tgid += 1; 3104 goto retry; 3105 } 3106 get_task_struct(iter.task); 3107 } 3108 rcu_read_unlock(); 3109 return iter; 3110 } 3111 3112 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 3113 3114 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3115 struct tgid_iter iter) 3116 { 3117 char name[PROC_NUMBUF]; 3118 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 3119 return proc_fill_cache(filp, dirent, filldir, name, len, 3120 proc_pid_instantiate, iter.task, NULL); 3121 } 3122 3123 /* for the /proc/ directory itself, after non-process stuff has been done */ 3124 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 3125 { 3126 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; 3127 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode); 3128 struct tgid_iter iter; 3129 struct pid_namespace *ns; 3130 3131 if (!reaper) 3132 goto out_no_task; 3133 3134 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 3135 const struct pid_entry *p = &proc_base_stuff[nr]; 3136 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 3137 goto out; 3138 } 3139 3140 ns = filp->f_dentry->d_sb->s_fs_info; 3141 iter.task = NULL; 3142 iter.tgid = filp->f_pos - TGID_OFFSET; 3143 for (iter = next_tgid(ns, iter); 3144 iter.task; 3145 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3146 filp->f_pos = iter.tgid + TGID_OFFSET; 3147 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) { 3148 put_task_struct(iter.task); 3149 goto out; 3150 } 3151 } 3152 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 3153 out: 3154 put_task_struct(reaper); 3155 out_no_task: 3156 return 0; 3157 } 3158 3159 /* 3160 * Tasks 3161 */ 3162 static const struct pid_entry tid_base_stuff[] = { 3163 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3164 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3165 REG("environ", S_IRUSR, proc_environ_operations), 3166 INF("auxv", S_IRUSR, proc_pid_auxv), 3167 ONE("status", S_IRUGO, proc_pid_status), 3168 ONE("personality", S_IRUSR, proc_pid_personality), 3169 INF("limits", S_IRUGO, proc_pid_limits), 3170 #ifdef CONFIG_SCHED_DEBUG 3171 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3172 #endif 3173 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3174 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3175 INF("syscall", S_IRUSR, proc_pid_syscall), 3176 #endif 3177 INF("cmdline", S_IRUGO, proc_pid_cmdline), 3178 ONE("stat", S_IRUGO, proc_tid_stat), 3179 ONE("statm", S_IRUGO, proc_pid_statm), 3180 REG("maps", S_IRUGO, proc_maps_operations), 3181 #ifdef CONFIG_NUMA 3182 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 3183 #endif 3184 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3185 LNK("cwd", proc_cwd_link), 3186 LNK("root", proc_root_link), 3187 LNK("exe", proc_exe_link), 3188 REG("mounts", S_IRUGO, proc_mounts_operations), 3189 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3190 #ifdef CONFIG_PROC_PAGE_MONITOR 3191 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3192 REG("smaps", S_IRUGO, proc_smaps_operations), 3193 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3194 #endif 3195 #ifdef CONFIG_SECURITY 3196 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3197 #endif 3198 #ifdef CONFIG_KALLSYMS 3199 INF("wchan", S_IRUGO, proc_pid_wchan), 3200 #endif 3201 #ifdef CONFIG_STACKTRACE 3202 ONE("stack", S_IRUSR, proc_pid_stack), 3203 #endif 3204 #ifdef CONFIG_SCHEDSTATS 3205 INF("schedstat", S_IRUGO, proc_pid_schedstat), 3206 #endif 3207 #ifdef CONFIG_LATENCYTOP 3208 REG("latency", S_IRUGO, proc_lstats_operations), 3209 #endif 3210 #ifdef CONFIG_PROC_PID_CPUSET 3211 REG("cpuset", S_IRUGO, proc_cpuset_operations), 3212 #endif 3213 #ifdef CONFIG_CGROUPS 3214 REG("cgroup", S_IRUGO, proc_cgroup_operations), 3215 #endif 3216 INF("oom_score", S_IRUGO, proc_oom_score), 3217 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 3218 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3219 #ifdef CONFIG_AUDITSYSCALL 3220 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3221 REG("sessionid", S_IRUSR, proc_sessionid_operations), 3222 #endif 3223 #ifdef CONFIG_FAULT_INJECTION 3224 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3225 #endif 3226 #ifdef CONFIG_TASK_IO_ACCOUNTING 3227 INF("io", S_IRUGO, proc_tid_io_accounting), 3228 #endif 3229 }; 3230 3231 static int proc_tid_base_readdir(struct file * filp, 3232 void * dirent, filldir_t filldir) 3233 { 3234 return proc_pident_readdir(filp,dirent,filldir, 3235 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 3236 } 3237 3238 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 3239 return proc_pident_lookup(dir, dentry, 3240 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3241 } 3242 3243 static const struct file_operations proc_tid_base_operations = { 3244 .read = generic_read_dir, 3245 .readdir = proc_tid_base_readdir, 3246 .llseek = default_llseek, 3247 }; 3248 3249 static const struct inode_operations proc_tid_base_inode_operations = { 3250 .lookup = proc_tid_base_lookup, 3251 .getattr = pid_getattr, 3252 .setattr = proc_setattr, 3253 }; 3254 3255 static struct dentry *proc_task_instantiate(struct inode *dir, 3256 struct dentry *dentry, struct task_struct *task, const void *ptr) 3257 { 3258 struct dentry *error = ERR_PTR(-ENOENT); 3259 struct inode *inode; 3260 inode = proc_pid_make_inode(dir->i_sb, task); 3261 3262 if (!inode) 3263 goto out; 3264 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3265 inode->i_op = &proc_tid_base_inode_operations; 3266 inode->i_fop = &proc_tid_base_operations; 3267 inode->i_flags|=S_IMMUTABLE; 3268 3269 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff, 3270 ARRAY_SIZE(tid_base_stuff)); 3271 3272 d_set_d_op(dentry, &pid_dentry_operations); 3273 3274 d_add(dentry, inode); 3275 /* Close the race of the process dying before we return the dentry */ 3276 if (pid_revalidate(dentry, NULL)) 3277 error = NULL; 3278 out: 3279 return error; 3280 } 3281 3282 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 3283 { 3284 struct dentry *result = ERR_PTR(-ENOENT); 3285 struct task_struct *task; 3286 struct task_struct *leader = get_proc_task(dir); 3287 unsigned tid; 3288 struct pid_namespace *ns; 3289 3290 if (!leader) 3291 goto out_no_task; 3292 3293 tid = name_to_int(dentry); 3294 if (tid == ~0U) 3295 goto out; 3296 3297 ns = dentry->d_sb->s_fs_info; 3298 rcu_read_lock(); 3299 task = find_task_by_pid_ns(tid, ns); 3300 if (task) 3301 get_task_struct(task); 3302 rcu_read_unlock(); 3303 if (!task) 3304 goto out; 3305 if (!same_thread_group(leader, task)) 3306 goto out_drop_task; 3307 3308 result = proc_task_instantiate(dir, dentry, task, NULL); 3309 out_drop_task: 3310 put_task_struct(task); 3311 out: 3312 put_task_struct(leader); 3313 out_no_task: 3314 return result; 3315 } 3316 3317 /* 3318 * Find the first tid of a thread group to return to user space. 3319 * 3320 * Usually this is just the thread group leader, but if the users 3321 * buffer was too small or there was a seek into the middle of the 3322 * directory we have more work todo. 3323 * 3324 * In the case of a short read we start with find_task_by_pid. 3325 * 3326 * In the case of a seek we start with the leader and walk nr 3327 * threads past it. 3328 */ 3329 static struct task_struct *first_tid(struct task_struct *leader, 3330 int tid, int nr, struct pid_namespace *ns) 3331 { 3332 struct task_struct *pos; 3333 3334 rcu_read_lock(); 3335 /* Attempt to start with the pid of a thread */ 3336 if (tid && (nr > 0)) { 3337 pos = find_task_by_pid_ns(tid, ns); 3338 if (pos && (pos->group_leader == leader)) 3339 goto found; 3340 } 3341 3342 /* If nr exceeds the number of threads there is nothing todo */ 3343 pos = NULL; 3344 if (nr && nr >= get_nr_threads(leader)) 3345 goto out; 3346 3347 /* If we haven't found our starting place yet start 3348 * with the leader and walk nr threads forward. 3349 */ 3350 for (pos = leader; nr > 0; --nr) { 3351 pos = next_thread(pos); 3352 if (pos == leader) { 3353 pos = NULL; 3354 goto out; 3355 } 3356 } 3357 found: 3358 get_task_struct(pos); 3359 out: 3360 rcu_read_unlock(); 3361 return pos; 3362 } 3363 3364 /* 3365 * Find the next thread in the thread list. 3366 * Return NULL if there is an error or no next thread. 3367 * 3368 * The reference to the input task_struct is released. 3369 */ 3370 static struct task_struct *next_tid(struct task_struct *start) 3371 { 3372 struct task_struct *pos = NULL; 3373 rcu_read_lock(); 3374 if (pid_alive(start)) { 3375 pos = next_thread(start); 3376 if (thread_group_leader(pos)) 3377 pos = NULL; 3378 else 3379 get_task_struct(pos); 3380 } 3381 rcu_read_unlock(); 3382 put_task_struct(start); 3383 return pos; 3384 } 3385 3386 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3387 struct task_struct *task, int tid) 3388 { 3389 char name[PROC_NUMBUF]; 3390 int len = snprintf(name, sizeof(name), "%d", tid); 3391 return proc_fill_cache(filp, dirent, filldir, name, len, 3392 proc_task_instantiate, task, NULL); 3393 } 3394 3395 /* for the /proc/TGID/task/ directories */ 3396 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 3397 { 3398 struct dentry *dentry = filp->f_path.dentry; 3399 struct inode *inode = dentry->d_inode; 3400 struct task_struct *leader = NULL; 3401 struct task_struct *task; 3402 int retval = -ENOENT; 3403 ino_t ino; 3404 int tid; 3405 struct pid_namespace *ns; 3406 3407 task = get_proc_task(inode); 3408 if (!task) 3409 goto out_no_task; 3410 rcu_read_lock(); 3411 if (pid_alive(task)) { 3412 leader = task->group_leader; 3413 get_task_struct(leader); 3414 } 3415 rcu_read_unlock(); 3416 put_task_struct(task); 3417 if (!leader) 3418 goto out_no_task; 3419 retval = 0; 3420 3421 switch ((unsigned long)filp->f_pos) { 3422 case 0: 3423 ino = inode->i_ino; 3424 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0) 3425 goto out; 3426 filp->f_pos++; 3427 /* fall through */ 3428 case 1: 3429 ino = parent_ino(dentry); 3430 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0) 3431 goto out; 3432 filp->f_pos++; 3433 /* fall through */ 3434 } 3435 3436 /* f_version caches the tgid value that the last readdir call couldn't 3437 * return. lseek aka telldir automagically resets f_version to 0. 3438 */ 3439 ns = filp->f_dentry->d_sb->s_fs_info; 3440 tid = (int)filp->f_version; 3441 filp->f_version = 0; 3442 for (task = first_tid(leader, tid, filp->f_pos - 2, ns); 3443 task; 3444 task = next_tid(task), filp->f_pos++) { 3445 tid = task_pid_nr_ns(task, ns); 3446 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 3447 /* returning this tgid failed, save it as the first 3448 * pid for the next readir call */ 3449 filp->f_version = (u64)tid; 3450 put_task_struct(task); 3451 break; 3452 } 3453 } 3454 out: 3455 put_task_struct(leader); 3456 out_no_task: 3457 return retval; 3458 } 3459 3460 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3461 { 3462 struct inode *inode = dentry->d_inode; 3463 struct task_struct *p = get_proc_task(inode); 3464 generic_fillattr(inode, stat); 3465 3466 if (p) { 3467 stat->nlink += get_nr_threads(p); 3468 put_task_struct(p); 3469 } 3470 3471 return 0; 3472 } 3473 3474 static const struct inode_operations proc_task_inode_operations = { 3475 .lookup = proc_task_lookup, 3476 .getattr = proc_task_getattr, 3477 .setattr = proc_setattr, 3478 }; 3479 3480 static const struct file_operations proc_task_operations = { 3481 .read = generic_read_dir, 3482 .readdir = proc_task_readdir, 3483 .llseek = default_llseek, 3484 }; 3485