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->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->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 return 0; 775 } 776 777 static ssize_t mem_read(struct file * file, char __user * buf, 778 size_t count, loff_t *ppos) 779 { 780 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 781 char *page; 782 unsigned long src = *ppos; 783 int ret = -ESRCH; 784 struct mm_struct *mm; 785 786 if (!task) 787 goto out_no_task; 788 789 if (check_mem_permission(task)) 790 goto out; 791 792 ret = -ENOMEM; 793 page = (char *)__get_free_page(GFP_TEMPORARY); 794 if (!page) 795 goto out; 796 797 ret = 0; 798 799 mm = get_task_mm(task); 800 if (!mm) 801 goto out_free; 802 803 ret = -EIO; 804 805 if (file->private_data != (void*)((long)current->self_exec_id)) 806 goto out_put; 807 808 ret = 0; 809 810 while (count > 0) { 811 int this_len, retval; 812 813 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 814 retval = access_process_vm(task, src, page, this_len, 0); 815 if (!retval || check_mem_permission(task)) { 816 if (!ret) 817 ret = -EIO; 818 break; 819 } 820 821 if (copy_to_user(buf, page, retval)) { 822 ret = -EFAULT; 823 break; 824 } 825 826 ret += retval; 827 src += retval; 828 buf += retval; 829 count -= retval; 830 } 831 *ppos = src; 832 833 out_put: 834 mmput(mm); 835 out_free: 836 free_page((unsigned long) page); 837 out: 838 put_task_struct(task); 839 out_no_task: 840 return ret; 841 } 842 843 #define mem_write NULL 844 845 #ifndef mem_write 846 /* This is a security hazard */ 847 static ssize_t mem_write(struct file * file, const char __user *buf, 848 size_t count, loff_t *ppos) 849 { 850 int copied; 851 char *page; 852 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 853 unsigned long dst = *ppos; 854 855 copied = -ESRCH; 856 if (!task) 857 goto out_no_task; 858 859 if (check_mem_permission(task)) 860 goto out; 861 862 copied = -ENOMEM; 863 page = (char *)__get_free_page(GFP_TEMPORARY); 864 if (!page) 865 goto out; 866 867 copied = 0; 868 while (count > 0) { 869 int this_len, retval; 870 871 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 872 if (copy_from_user(page, buf, this_len)) { 873 copied = -EFAULT; 874 break; 875 } 876 retval = access_process_vm(task, dst, page, this_len, 1); 877 if (!retval) { 878 if (!copied) 879 copied = -EIO; 880 break; 881 } 882 copied += retval; 883 buf += retval; 884 dst += retval; 885 count -= retval; 886 } 887 *ppos = dst; 888 free_page((unsigned long) page); 889 out: 890 put_task_struct(task); 891 out_no_task: 892 return copied; 893 } 894 #endif 895 896 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 897 { 898 switch (orig) { 899 case 0: 900 file->f_pos = offset; 901 break; 902 case 1: 903 file->f_pos += offset; 904 break; 905 default: 906 return -EINVAL; 907 } 908 force_successful_syscall_return(); 909 return file->f_pos; 910 } 911 912 static const struct file_operations proc_mem_operations = { 913 .llseek = mem_lseek, 914 .read = mem_read, 915 .write = mem_write, 916 .open = mem_open, 917 }; 918 919 static ssize_t environ_read(struct file *file, char __user *buf, 920 size_t count, loff_t *ppos) 921 { 922 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 923 char *page; 924 unsigned long src = *ppos; 925 int ret = -ESRCH; 926 struct mm_struct *mm; 927 928 if (!task) 929 goto out_no_task; 930 931 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 932 goto out; 933 934 ret = -ENOMEM; 935 page = (char *)__get_free_page(GFP_TEMPORARY); 936 if (!page) 937 goto out; 938 939 ret = 0; 940 941 mm = get_task_mm(task); 942 if (!mm) 943 goto out_free; 944 945 while (count > 0) { 946 int this_len, retval, max_len; 947 948 this_len = mm->env_end - (mm->env_start + src); 949 950 if (this_len <= 0) 951 break; 952 953 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 954 this_len = (this_len > max_len) ? max_len : this_len; 955 956 retval = access_process_vm(task, (mm->env_start + src), 957 page, this_len, 0); 958 959 if (retval <= 0) { 960 ret = retval; 961 break; 962 } 963 964 if (copy_to_user(buf, page, retval)) { 965 ret = -EFAULT; 966 break; 967 } 968 969 ret += retval; 970 src += retval; 971 buf += retval; 972 count -= retval; 973 } 974 *ppos = src; 975 976 mmput(mm); 977 out_free: 978 free_page((unsigned long) page); 979 out: 980 put_task_struct(task); 981 out_no_task: 982 return ret; 983 } 984 985 static const struct file_operations proc_environ_operations = { 986 .read = environ_read, 987 .llseek = generic_file_llseek, 988 }; 989 990 static ssize_t oom_adjust_read(struct file *file, char __user *buf, 991 size_t count, loff_t *ppos) 992 { 993 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 994 char buffer[PROC_NUMBUF]; 995 size_t len; 996 int oom_adjust = OOM_DISABLE; 997 unsigned long flags; 998 999 if (!task) 1000 return -ESRCH; 1001 1002 if (lock_task_sighand(task, &flags)) { 1003 oom_adjust = task->signal->oom_adj; 1004 unlock_task_sighand(task, &flags); 1005 } 1006 1007 put_task_struct(task); 1008 1009 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); 1010 1011 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1012 } 1013 1014 static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 1015 size_t count, loff_t *ppos) 1016 { 1017 struct task_struct *task; 1018 char buffer[PROC_NUMBUF]; 1019 long oom_adjust; 1020 unsigned long flags; 1021 int err; 1022 1023 memset(buffer, 0, sizeof(buffer)); 1024 if (count > sizeof(buffer) - 1) 1025 count = sizeof(buffer) - 1; 1026 if (copy_from_user(buffer, buf, count)) 1027 return -EFAULT; 1028 1029 err = strict_strtol(strstrip(buffer), 0, &oom_adjust); 1030 if (err) 1031 return -EINVAL; 1032 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && 1033 oom_adjust != OOM_DISABLE) 1034 return -EINVAL; 1035 1036 task = get_proc_task(file->f_path.dentry->d_inode); 1037 if (!task) 1038 return -ESRCH; 1039 if (!lock_task_sighand(task, &flags)) { 1040 put_task_struct(task); 1041 return -ESRCH; 1042 } 1043 1044 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) { 1045 unlock_task_sighand(task, &flags); 1046 put_task_struct(task); 1047 return -EACCES; 1048 } 1049 1050 /* 1051 * Warn that /proc/pid/oom_adj is deprecated, see 1052 * Documentation/feature-removal-schedule.txt. 1053 */ 1054 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, " 1055 "please use /proc/%d/oom_score_adj instead.\n", 1056 current->comm, task_pid_nr(current), 1057 task_pid_nr(task), task_pid_nr(task)); 1058 task->signal->oom_adj = oom_adjust; 1059 /* 1060 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 1061 * value is always attainable. 1062 */ 1063 if (task->signal->oom_adj == OOM_ADJUST_MAX) 1064 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX; 1065 else 1066 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) / 1067 -OOM_DISABLE; 1068 unlock_task_sighand(task, &flags); 1069 put_task_struct(task); 1070 1071 return count; 1072 } 1073 1074 static const struct file_operations proc_oom_adjust_operations = { 1075 .read = oom_adjust_read, 1076 .write = oom_adjust_write, 1077 .llseek = generic_file_llseek, 1078 }; 1079 1080 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 1081 size_t count, loff_t *ppos) 1082 { 1083 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 1084 char buffer[PROC_NUMBUF]; 1085 int oom_score_adj = OOM_SCORE_ADJ_MIN; 1086 unsigned long flags; 1087 size_t len; 1088 1089 if (!task) 1090 return -ESRCH; 1091 if (lock_task_sighand(task, &flags)) { 1092 oom_score_adj = task->signal->oom_score_adj; 1093 unlock_task_sighand(task, &flags); 1094 } 1095 put_task_struct(task); 1096 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj); 1097 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1098 } 1099 1100 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1101 size_t count, loff_t *ppos) 1102 { 1103 struct task_struct *task; 1104 char buffer[PROC_NUMBUF]; 1105 unsigned long flags; 1106 long oom_score_adj; 1107 int err; 1108 1109 memset(buffer, 0, sizeof(buffer)); 1110 if (count > sizeof(buffer) - 1) 1111 count = sizeof(buffer) - 1; 1112 if (copy_from_user(buffer, buf, count)) 1113 return -EFAULT; 1114 1115 err = strict_strtol(strstrip(buffer), 0, &oom_score_adj); 1116 if (err) 1117 return -EINVAL; 1118 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1119 oom_score_adj > OOM_SCORE_ADJ_MAX) 1120 return -EINVAL; 1121 1122 task = get_proc_task(file->f_path.dentry->d_inode); 1123 if (!task) 1124 return -ESRCH; 1125 if (!lock_task_sighand(task, &flags)) { 1126 put_task_struct(task); 1127 return -ESRCH; 1128 } 1129 if (oom_score_adj < task->signal->oom_score_adj && 1130 !capable(CAP_SYS_RESOURCE)) { 1131 unlock_task_sighand(task, &flags); 1132 put_task_struct(task); 1133 return -EACCES; 1134 } 1135 1136 task->signal->oom_score_adj = oom_score_adj; 1137 /* 1138 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is 1139 * always attainable. 1140 */ 1141 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) 1142 task->signal->oom_adj = OOM_DISABLE; 1143 else 1144 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) / 1145 OOM_SCORE_ADJ_MAX; 1146 unlock_task_sighand(task, &flags); 1147 put_task_struct(task); 1148 return count; 1149 } 1150 1151 static const struct file_operations proc_oom_score_adj_operations = { 1152 .read = oom_score_adj_read, 1153 .write = oom_score_adj_write, 1154 .llseek = default_llseek, 1155 }; 1156 1157 #ifdef CONFIG_AUDITSYSCALL 1158 #define TMPBUFLEN 21 1159 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1160 size_t count, loff_t *ppos) 1161 { 1162 struct inode * inode = file->f_path.dentry->d_inode; 1163 struct task_struct *task = get_proc_task(inode); 1164 ssize_t length; 1165 char tmpbuf[TMPBUFLEN]; 1166 1167 if (!task) 1168 return -ESRCH; 1169 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1170 audit_get_loginuid(task)); 1171 put_task_struct(task); 1172 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1173 } 1174 1175 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1176 size_t count, loff_t *ppos) 1177 { 1178 struct inode * inode = file->f_path.dentry->d_inode; 1179 char *page, *tmp; 1180 ssize_t length; 1181 uid_t loginuid; 1182 1183 if (!capable(CAP_AUDIT_CONTROL)) 1184 return -EPERM; 1185 1186 rcu_read_lock(); 1187 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1188 rcu_read_unlock(); 1189 return -EPERM; 1190 } 1191 rcu_read_unlock(); 1192 1193 if (count >= PAGE_SIZE) 1194 count = PAGE_SIZE - 1; 1195 1196 if (*ppos != 0) { 1197 /* No partial writes. */ 1198 return -EINVAL; 1199 } 1200 page = (char*)__get_free_page(GFP_TEMPORARY); 1201 if (!page) 1202 return -ENOMEM; 1203 length = -EFAULT; 1204 if (copy_from_user(page, buf, count)) 1205 goto out_free_page; 1206 1207 page[count] = '\0'; 1208 loginuid = simple_strtoul(page, &tmp, 10); 1209 if (tmp == page) { 1210 length = -EINVAL; 1211 goto out_free_page; 1212 1213 } 1214 length = audit_set_loginuid(current, loginuid); 1215 if (likely(length == 0)) 1216 length = count; 1217 1218 out_free_page: 1219 free_page((unsigned long) page); 1220 return length; 1221 } 1222 1223 static const struct file_operations proc_loginuid_operations = { 1224 .read = proc_loginuid_read, 1225 .write = proc_loginuid_write, 1226 .llseek = generic_file_llseek, 1227 }; 1228 1229 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1230 size_t count, loff_t *ppos) 1231 { 1232 struct inode * inode = file->f_path.dentry->d_inode; 1233 struct task_struct *task = get_proc_task(inode); 1234 ssize_t length; 1235 char tmpbuf[TMPBUFLEN]; 1236 1237 if (!task) 1238 return -ESRCH; 1239 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1240 audit_get_sessionid(task)); 1241 put_task_struct(task); 1242 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1243 } 1244 1245 static const struct file_operations proc_sessionid_operations = { 1246 .read = proc_sessionid_read, 1247 .llseek = generic_file_llseek, 1248 }; 1249 #endif 1250 1251 #ifdef CONFIG_FAULT_INJECTION 1252 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1253 size_t count, loff_t *ppos) 1254 { 1255 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1256 char buffer[PROC_NUMBUF]; 1257 size_t len; 1258 int make_it_fail; 1259 1260 if (!task) 1261 return -ESRCH; 1262 make_it_fail = task->make_it_fail; 1263 put_task_struct(task); 1264 1265 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1266 1267 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1268 } 1269 1270 static ssize_t proc_fault_inject_write(struct file * file, 1271 const char __user * buf, size_t count, loff_t *ppos) 1272 { 1273 struct task_struct *task; 1274 char buffer[PROC_NUMBUF], *end; 1275 int make_it_fail; 1276 1277 if (!capable(CAP_SYS_RESOURCE)) 1278 return -EPERM; 1279 memset(buffer, 0, sizeof(buffer)); 1280 if (count > sizeof(buffer) - 1) 1281 count = sizeof(buffer) - 1; 1282 if (copy_from_user(buffer, buf, count)) 1283 return -EFAULT; 1284 make_it_fail = simple_strtol(strstrip(buffer), &end, 0); 1285 if (*end) 1286 return -EINVAL; 1287 task = get_proc_task(file->f_dentry->d_inode); 1288 if (!task) 1289 return -ESRCH; 1290 task->make_it_fail = make_it_fail; 1291 put_task_struct(task); 1292 1293 return count; 1294 } 1295 1296 static const struct file_operations proc_fault_inject_operations = { 1297 .read = proc_fault_inject_read, 1298 .write = proc_fault_inject_write, 1299 .llseek = generic_file_llseek, 1300 }; 1301 #endif 1302 1303 1304 #ifdef CONFIG_SCHED_DEBUG 1305 /* 1306 * Print out various scheduling related per-task fields: 1307 */ 1308 static int sched_show(struct seq_file *m, void *v) 1309 { 1310 struct inode *inode = m->private; 1311 struct task_struct *p; 1312 1313 p = get_proc_task(inode); 1314 if (!p) 1315 return -ESRCH; 1316 proc_sched_show_task(p, m); 1317 1318 put_task_struct(p); 1319 1320 return 0; 1321 } 1322 1323 static ssize_t 1324 sched_write(struct file *file, const char __user *buf, 1325 size_t count, loff_t *offset) 1326 { 1327 struct inode *inode = file->f_path.dentry->d_inode; 1328 struct task_struct *p; 1329 1330 p = get_proc_task(inode); 1331 if (!p) 1332 return -ESRCH; 1333 proc_sched_set_task(p); 1334 1335 put_task_struct(p); 1336 1337 return count; 1338 } 1339 1340 static int sched_open(struct inode *inode, struct file *filp) 1341 { 1342 int ret; 1343 1344 ret = single_open(filp, sched_show, NULL); 1345 if (!ret) { 1346 struct seq_file *m = filp->private_data; 1347 1348 m->private = inode; 1349 } 1350 return ret; 1351 } 1352 1353 static const struct file_operations proc_pid_sched_operations = { 1354 .open = sched_open, 1355 .read = seq_read, 1356 .write = sched_write, 1357 .llseek = seq_lseek, 1358 .release = single_release, 1359 }; 1360 1361 #endif 1362 1363 static ssize_t comm_write(struct file *file, const char __user *buf, 1364 size_t count, loff_t *offset) 1365 { 1366 struct inode *inode = file->f_path.dentry->d_inode; 1367 struct task_struct *p; 1368 char buffer[TASK_COMM_LEN]; 1369 1370 memset(buffer, 0, sizeof(buffer)); 1371 if (count > sizeof(buffer) - 1) 1372 count = sizeof(buffer) - 1; 1373 if (copy_from_user(buffer, buf, count)) 1374 return -EFAULT; 1375 1376 p = get_proc_task(inode); 1377 if (!p) 1378 return -ESRCH; 1379 1380 if (same_thread_group(current, p)) 1381 set_task_comm(p, buffer); 1382 else 1383 count = -EINVAL; 1384 1385 put_task_struct(p); 1386 1387 return count; 1388 } 1389 1390 static int comm_show(struct seq_file *m, void *v) 1391 { 1392 struct inode *inode = m->private; 1393 struct task_struct *p; 1394 1395 p = get_proc_task(inode); 1396 if (!p) 1397 return -ESRCH; 1398 1399 task_lock(p); 1400 seq_printf(m, "%s\n", p->comm); 1401 task_unlock(p); 1402 1403 put_task_struct(p); 1404 1405 return 0; 1406 } 1407 1408 static int comm_open(struct inode *inode, struct file *filp) 1409 { 1410 int ret; 1411 1412 ret = single_open(filp, comm_show, NULL); 1413 if (!ret) { 1414 struct seq_file *m = filp->private_data; 1415 1416 m->private = inode; 1417 } 1418 return ret; 1419 } 1420 1421 static const struct file_operations proc_pid_set_comm_operations = { 1422 .open = comm_open, 1423 .read = seq_read, 1424 .write = comm_write, 1425 .llseek = seq_lseek, 1426 .release = single_release, 1427 }; 1428 1429 /* 1430 * We added or removed a vma mapping the executable. The vmas are only mapped 1431 * during exec and are not mapped with the mmap system call. 1432 * Callers must hold down_write() on the mm's mmap_sem for these 1433 */ 1434 void added_exe_file_vma(struct mm_struct *mm) 1435 { 1436 mm->num_exe_file_vmas++; 1437 } 1438 1439 void removed_exe_file_vma(struct mm_struct *mm) 1440 { 1441 mm->num_exe_file_vmas--; 1442 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){ 1443 fput(mm->exe_file); 1444 mm->exe_file = NULL; 1445 } 1446 1447 } 1448 1449 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) 1450 { 1451 if (new_exe_file) 1452 get_file(new_exe_file); 1453 if (mm->exe_file) 1454 fput(mm->exe_file); 1455 mm->exe_file = new_exe_file; 1456 mm->num_exe_file_vmas = 0; 1457 } 1458 1459 struct file *get_mm_exe_file(struct mm_struct *mm) 1460 { 1461 struct file *exe_file; 1462 1463 /* We need mmap_sem to protect against races with removal of 1464 * VM_EXECUTABLE vmas */ 1465 down_read(&mm->mmap_sem); 1466 exe_file = mm->exe_file; 1467 if (exe_file) 1468 get_file(exe_file); 1469 up_read(&mm->mmap_sem); 1470 return exe_file; 1471 } 1472 1473 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm) 1474 { 1475 /* It's safe to write the exe_file pointer without exe_file_lock because 1476 * this is called during fork when the task is not yet in /proc */ 1477 newmm->exe_file = get_mm_exe_file(oldmm); 1478 } 1479 1480 static int proc_exe_link(struct inode *inode, struct path *exe_path) 1481 { 1482 struct task_struct *task; 1483 struct mm_struct *mm; 1484 struct file *exe_file; 1485 1486 task = get_proc_task(inode); 1487 if (!task) 1488 return -ENOENT; 1489 mm = get_task_mm(task); 1490 put_task_struct(task); 1491 if (!mm) 1492 return -ENOENT; 1493 exe_file = get_mm_exe_file(mm); 1494 mmput(mm); 1495 if (exe_file) { 1496 *exe_path = exe_file->f_path; 1497 path_get(&exe_file->f_path); 1498 fput(exe_file); 1499 return 0; 1500 } else 1501 return -ENOENT; 1502 } 1503 1504 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1505 { 1506 struct inode *inode = dentry->d_inode; 1507 int error = -EACCES; 1508 1509 /* We don't need a base pointer in the /proc filesystem */ 1510 path_put(&nd->path); 1511 1512 /* Are we allowed to snoop on the tasks file descriptors? */ 1513 if (!proc_fd_access_allowed(inode)) 1514 goto out; 1515 1516 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path); 1517 out: 1518 return ERR_PTR(error); 1519 } 1520 1521 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1522 { 1523 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1524 char *pathname; 1525 int len; 1526 1527 if (!tmp) 1528 return -ENOMEM; 1529 1530 pathname = d_path_with_unreachable(path, tmp, PAGE_SIZE); 1531 len = PTR_ERR(pathname); 1532 if (IS_ERR(pathname)) 1533 goto out; 1534 len = tmp + PAGE_SIZE - 1 - pathname; 1535 1536 if (len > buflen) 1537 len = buflen; 1538 if (copy_to_user(buffer, pathname, len)) 1539 len = -EFAULT; 1540 out: 1541 free_page((unsigned long)tmp); 1542 return len; 1543 } 1544 1545 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1546 { 1547 int error = -EACCES; 1548 struct inode *inode = dentry->d_inode; 1549 struct path path; 1550 1551 /* Are we allowed to snoop on the tasks file descriptors? */ 1552 if (!proc_fd_access_allowed(inode)) 1553 goto out; 1554 1555 error = PROC_I(inode)->op.proc_get_link(inode, &path); 1556 if (error) 1557 goto out; 1558 1559 error = do_proc_readlink(&path, buffer, buflen); 1560 path_put(&path); 1561 out: 1562 return error; 1563 } 1564 1565 static const struct inode_operations proc_pid_link_inode_operations = { 1566 .readlink = proc_pid_readlink, 1567 .follow_link = proc_pid_follow_link, 1568 .setattr = proc_setattr, 1569 }; 1570 1571 1572 /* building an inode */ 1573 1574 static int task_dumpable(struct task_struct *task) 1575 { 1576 int dumpable = 0; 1577 struct mm_struct *mm; 1578 1579 task_lock(task); 1580 mm = task->mm; 1581 if (mm) 1582 dumpable = get_dumpable(mm); 1583 task_unlock(task); 1584 if(dumpable == 1) 1585 return 1; 1586 return 0; 1587 } 1588 1589 1590 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1591 { 1592 struct inode * inode; 1593 struct proc_inode *ei; 1594 const struct cred *cred; 1595 1596 /* We need a new inode */ 1597 1598 inode = new_inode(sb); 1599 if (!inode) 1600 goto out; 1601 1602 /* Common stuff */ 1603 ei = PROC_I(inode); 1604 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1605 inode->i_op = &proc_def_inode_operations; 1606 1607 /* 1608 * grab the reference to task. 1609 */ 1610 ei->pid = get_task_pid(task, PIDTYPE_PID); 1611 if (!ei->pid) 1612 goto out_unlock; 1613 1614 if (task_dumpable(task)) { 1615 rcu_read_lock(); 1616 cred = __task_cred(task); 1617 inode->i_uid = cred->euid; 1618 inode->i_gid = cred->egid; 1619 rcu_read_unlock(); 1620 } 1621 security_task_to_inode(task, inode); 1622 1623 out: 1624 return inode; 1625 1626 out_unlock: 1627 iput(inode); 1628 return NULL; 1629 } 1630 1631 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1632 { 1633 struct inode *inode = dentry->d_inode; 1634 struct task_struct *task; 1635 const struct cred *cred; 1636 1637 generic_fillattr(inode, stat); 1638 1639 rcu_read_lock(); 1640 stat->uid = 0; 1641 stat->gid = 0; 1642 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1643 if (task) { 1644 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1645 task_dumpable(task)) { 1646 cred = __task_cred(task); 1647 stat->uid = cred->euid; 1648 stat->gid = cred->egid; 1649 } 1650 } 1651 rcu_read_unlock(); 1652 return 0; 1653 } 1654 1655 /* dentry stuff */ 1656 1657 /* 1658 * Exceptional case: normally we are not allowed to unhash a busy 1659 * directory. In this case, however, we can do it - no aliasing problems 1660 * due to the way we treat inodes. 1661 * 1662 * Rewrite the inode's ownerships here because the owning task may have 1663 * performed a setuid(), etc. 1664 * 1665 * Before the /proc/pid/status file was created the only way to read 1666 * the effective uid of a /process was to stat /proc/pid. Reading 1667 * /proc/pid/status is slow enough that procps and other packages 1668 * kept stating /proc/pid. To keep the rules in /proc simple I have 1669 * made this apply to all per process world readable and executable 1670 * directories. 1671 */ 1672 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1673 { 1674 struct inode *inode = dentry->d_inode; 1675 struct task_struct *task = get_proc_task(inode); 1676 const struct cred *cred; 1677 1678 if (task) { 1679 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1680 task_dumpable(task)) { 1681 rcu_read_lock(); 1682 cred = __task_cred(task); 1683 inode->i_uid = cred->euid; 1684 inode->i_gid = cred->egid; 1685 rcu_read_unlock(); 1686 } else { 1687 inode->i_uid = 0; 1688 inode->i_gid = 0; 1689 } 1690 inode->i_mode &= ~(S_ISUID | S_ISGID); 1691 security_task_to_inode(task, inode); 1692 put_task_struct(task); 1693 return 1; 1694 } 1695 d_drop(dentry); 1696 return 0; 1697 } 1698 1699 static int pid_delete_dentry(struct dentry * dentry) 1700 { 1701 /* Is the task we represent dead? 1702 * If so, then don't put the dentry on the lru list, 1703 * kill it immediately. 1704 */ 1705 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1706 } 1707 1708 static const struct dentry_operations pid_dentry_operations = 1709 { 1710 .d_revalidate = pid_revalidate, 1711 .d_delete = pid_delete_dentry, 1712 }; 1713 1714 /* Lookups */ 1715 1716 typedef struct dentry *instantiate_t(struct inode *, struct dentry *, 1717 struct task_struct *, const void *); 1718 1719 /* 1720 * Fill a directory entry. 1721 * 1722 * If possible create the dcache entry and derive our inode number and 1723 * file type from dcache entry. 1724 * 1725 * Since all of the proc inode numbers are dynamically generated, the inode 1726 * numbers do not exist until the inode is cache. This means creating the 1727 * the dcache entry in readdir is necessary to keep the inode numbers 1728 * reported by readdir in sync with the inode numbers reported 1729 * by stat. 1730 */ 1731 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1732 char *name, int len, 1733 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1734 { 1735 struct dentry *child, *dir = filp->f_path.dentry; 1736 struct inode *inode; 1737 struct qstr qname; 1738 ino_t ino = 0; 1739 unsigned type = DT_UNKNOWN; 1740 1741 qname.name = name; 1742 qname.len = len; 1743 qname.hash = full_name_hash(name, len); 1744 1745 child = d_lookup(dir, &qname); 1746 if (!child) { 1747 struct dentry *new; 1748 new = d_alloc(dir, &qname); 1749 if (new) { 1750 child = instantiate(dir->d_inode, new, task, ptr); 1751 if (child) 1752 dput(new); 1753 else 1754 child = new; 1755 } 1756 } 1757 if (!child || IS_ERR(child) || !child->d_inode) 1758 goto end_instantiate; 1759 inode = child->d_inode; 1760 if (inode) { 1761 ino = inode->i_ino; 1762 type = inode->i_mode >> 12; 1763 } 1764 dput(child); 1765 end_instantiate: 1766 if (!ino) 1767 ino = find_inode_number(dir, &qname); 1768 if (!ino) 1769 ino = 1; 1770 return filldir(dirent, name, len, filp->f_pos, ino, type); 1771 } 1772 1773 static unsigned name_to_int(struct dentry *dentry) 1774 { 1775 const char *name = dentry->d_name.name; 1776 int len = dentry->d_name.len; 1777 unsigned n = 0; 1778 1779 if (len > 1 && *name == '0') 1780 goto out; 1781 while (len-- > 0) { 1782 unsigned c = *name++ - '0'; 1783 if (c > 9) 1784 goto out; 1785 if (n >= (~0U-9)/10) 1786 goto out; 1787 n *= 10; 1788 n += c; 1789 } 1790 return n; 1791 out: 1792 return ~0U; 1793 } 1794 1795 #define PROC_FDINFO_MAX 64 1796 1797 static int proc_fd_info(struct inode *inode, struct path *path, char *info) 1798 { 1799 struct task_struct *task = get_proc_task(inode); 1800 struct files_struct *files = NULL; 1801 struct file *file; 1802 int fd = proc_fd(inode); 1803 1804 if (task) { 1805 files = get_files_struct(task); 1806 put_task_struct(task); 1807 } 1808 if (files) { 1809 /* 1810 * We are not taking a ref to the file structure, so we must 1811 * hold ->file_lock. 1812 */ 1813 spin_lock(&files->file_lock); 1814 file = fcheck_files(files, fd); 1815 if (file) { 1816 if (path) { 1817 *path = file->f_path; 1818 path_get(&file->f_path); 1819 } 1820 if (info) 1821 snprintf(info, PROC_FDINFO_MAX, 1822 "pos:\t%lli\n" 1823 "flags:\t0%o\n", 1824 (long long) file->f_pos, 1825 file->f_flags); 1826 spin_unlock(&files->file_lock); 1827 put_files_struct(files); 1828 return 0; 1829 } 1830 spin_unlock(&files->file_lock); 1831 put_files_struct(files); 1832 } 1833 return -ENOENT; 1834 } 1835 1836 static int proc_fd_link(struct inode *inode, struct path *path) 1837 { 1838 return proc_fd_info(inode, path, NULL); 1839 } 1840 1841 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1842 { 1843 struct inode *inode = dentry->d_inode; 1844 struct task_struct *task = get_proc_task(inode); 1845 int fd = proc_fd(inode); 1846 struct files_struct *files; 1847 const struct cred *cred; 1848 1849 if (task) { 1850 files = get_files_struct(task); 1851 if (files) { 1852 rcu_read_lock(); 1853 if (fcheck_files(files, fd)) { 1854 rcu_read_unlock(); 1855 put_files_struct(files); 1856 if (task_dumpable(task)) { 1857 rcu_read_lock(); 1858 cred = __task_cred(task); 1859 inode->i_uid = cred->euid; 1860 inode->i_gid = cred->egid; 1861 rcu_read_unlock(); 1862 } else { 1863 inode->i_uid = 0; 1864 inode->i_gid = 0; 1865 } 1866 inode->i_mode &= ~(S_ISUID | S_ISGID); 1867 security_task_to_inode(task, inode); 1868 put_task_struct(task); 1869 return 1; 1870 } 1871 rcu_read_unlock(); 1872 put_files_struct(files); 1873 } 1874 put_task_struct(task); 1875 } 1876 d_drop(dentry); 1877 return 0; 1878 } 1879 1880 static const struct dentry_operations tid_fd_dentry_operations = 1881 { 1882 .d_revalidate = tid_fd_revalidate, 1883 .d_delete = pid_delete_dentry, 1884 }; 1885 1886 static struct dentry *proc_fd_instantiate(struct inode *dir, 1887 struct dentry *dentry, struct task_struct *task, const void *ptr) 1888 { 1889 unsigned fd = *(const unsigned *)ptr; 1890 struct file *file; 1891 struct files_struct *files; 1892 struct inode *inode; 1893 struct proc_inode *ei; 1894 struct dentry *error = ERR_PTR(-ENOENT); 1895 1896 inode = proc_pid_make_inode(dir->i_sb, task); 1897 if (!inode) 1898 goto out; 1899 ei = PROC_I(inode); 1900 ei->fd = fd; 1901 files = get_files_struct(task); 1902 if (!files) 1903 goto out_iput; 1904 inode->i_mode = S_IFLNK; 1905 1906 /* 1907 * We are not taking a ref to the file structure, so we must 1908 * hold ->file_lock. 1909 */ 1910 spin_lock(&files->file_lock); 1911 file = fcheck_files(files, fd); 1912 if (!file) 1913 goto out_unlock; 1914 if (file->f_mode & FMODE_READ) 1915 inode->i_mode |= S_IRUSR | S_IXUSR; 1916 if (file->f_mode & FMODE_WRITE) 1917 inode->i_mode |= S_IWUSR | S_IXUSR; 1918 spin_unlock(&files->file_lock); 1919 put_files_struct(files); 1920 1921 inode->i_op = &proc_pid_link_inode_operations; 1922 inode->i_size = 64; 1923 ei->op.proc_get_link = proc_fd_link; 1924 dentry->d_op = &tid_fd_dentry_operations; 1925 d_add(dentry, inode); 1926 /* Close the race of the process dying before we return the dentry */ 1927 if (tid_fd_revalidate(dentry, NULL)) 1928 error = NULL; 1929 1930 out: 1931 return error; 1932 out_unlock: 1933 spin_unlock(&files->file_lock); 1934 put_files_struct(files); 1935 out_iput: 1936 iput(inode); 1937 goto out; 1938 } 1939 1940 static struct dentry *proc_lookupfd_common(struct inode *dir, 1941 struct dentry *dentry, 1942 instantiate_t instantiate) 1943 { 1944 struct task_struct *task = get_proc_task(dir); 1945 unsigned fd = name_to_int(dentry); 1946 struct dentry *result = ERR_PTR(-ENOENT); 1947 1948 if (!task) 1949 goto out_no_task; 1950 if (fd == ~0U) 1951 goto out; 1952 1953 result = instantiate(dir, dentry, task, &fd); 1954 out: 1955 put_task_struct(task); 1956 out_no_task: 1957 return result; 1958 } 1959 1960 static int proc_readfd_common(struct file * filp, void * dirent, 1961 filldir_t filldir, instantiate_t instantiate) 1962 { 1963 struct dentry *dentry = filp->f_path.dentry; 1964 struct inode *inode = dentry->d_inode; 1965 struct task_struct *p = get_proc_task(inode); 1966 unsigned int fd, ino; 1967 int retval; 1968 struct files_struct * files; 1969 1970 retval = -ENOENT; 1971 if (!p) 1972 goto out_no_task; 1973 retval = 0; 1974 1975 fd = filp->f_pos; 1976 switch (fd) { 1977 case 0: 1978 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 1979 goto out; 1980 filp->f_pos++; 1981 case 1: 1982 ino = parent_ino(dentry); 1983 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 1984 goto out; 1985 filp->f_pos++; 1986 default: 1987 files = get_files_struct(p); 1988 if (!files) 1989 goto out; 1990 rcu_read_lock(); 1991 for (fd = filp->f_pos-2; 1992 fd < files_fdtable(files)->max_fds; 1993 fd++, filp->f_pos++) { 1994 char name[PROC_NUMBUF]; 1995 int len; 1996 1997 if (!fcheck_files(files, fd)) 1998 continue; 1999 rcu_read_unlock(); 2000 2001 len = snprintf(name, sizeof(name), "%d", fd); 2002 if (proc_fill_cache(filp, dirent, filldir, 2003 name, len, instantiate, 2004 p, &fd) < 0) { 2005 rcu_read_lock(); 2006 break; 2007 } 2008 rcu_read_lock(); 2009 } 2010 rcu_read_unlock(); 2011 put_files_struct(files); 2012 } 2013 out: 2014 put_task_struct(p); 2015 out_no_task: 2016 return retval; 2017 } 2018 2019 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 2020 struct nameidata *nd) 2021 { 2022 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 2023 } 2024 2025 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 2026 { 2027 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 2028 } 2029 2030 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 2031 size_t len, loff_t *ppos) 2032 { 2033 char tmp[PROC_FDINFO_MAX]; 2034 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); 2035 if (!err) 2036 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 2037 return err; 2038 } 2039 2040 static const struct file_operations proc_fdinfo_file_operations = { 2041 .open = nonseekable_open, 2042 .read = proc_fdinfo_read, 2043 .llseek = no_llseek, 2044 }; 2045 2046 static const struct file_operations proc_fd_operations = { 2047 .read = generic_read_dir, 2048 .readdir = proc_readfd, 2049 .llseek = default_llseek, 2050 }; 2051 2052 /* 2053 * /proc/pid/fd needs a special permission handler so that a process can still 2054 * access /proc/self/fd after it has executed a setuid(). 2055 */ 2056 static int proc_fd_permission(struct inode *inode, int mask) 2057 { 2058 int rv; 2059 2060 rv = generic_permission(inode, mask, NULL); 2061 if (rv == 0) 2062 return 0; 2063 if (task_pid(current) == proc_pid(inode)) 2064 rv = 0; 2065 return rv; 2066 } 2067 2068 /* 2069 * proc directories can do almost nothing.. 2070 */ 2071 static const struct inode_operations proc_fd_inode_operations = { 2072 .lookup = proc_lookupfd, 2073 .permission = proc_fd_permission, 2074 .setattr = proc_setattr, 2075 }; 2076 2077 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 2078 struct dentry *dentry, struct task_struct *task, const void *ptr) 2079 { 2080 unsigned fd = *(unsigned *)ptr; 2081 struct inode *inode; 2082 struct proc_inode *ei; 2083 struct dentry *error = ERR_PTR(-ENOENT); 2084 2085 inode = proc_pid_make_inode(dir->i_sb, task); 2086 if (!inode) 2087 goto out; 2088 ei = PROC_I(inode); 2089 ei->fd = fd; 2090 inode->i_mode = S_IFREG | S_IRUSR; 2091 inode->i_fop = &proc_fdinfo_file_operations; 2092 dentry->d_op = &tid_fd_dentry_operations; 2093 d_add(dentry, inode); 2094 /* Close the race of the process dying before we return the dentry */ 2095 if (tid_fd_revalidate(dentry, NULL)) 2096 error = NULL; 2097 2098 out: 2099 return error; 2100 } 2101 2102 static struct dentry *proc_lookupfdinfo(struct inode *dir, 2103 struct dentry *dentry, 2104 struct nameidata *nd) 2105 { 2106 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 2107 } 2108 2109 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 2110 { 2111 return proc_readfd_common(filp, dirent, filldir, 2112 proc_fdinfo_instantiate); 2113 } 2114 2115 static const struct file_operations proc_fdinfo_operations = { 2116 .read = generic_read_dir, 2117 .readdir = proc_readfdinfo, 2118 .llseek = default_llseek, 2119 }; 2120 2121 /* 2122 * proc directories can do almost nothing.. 2123 */ 2124 static const struct inode_operations proc_fdinfo_inode_operations = { 2125 .lookup = proc_lookupfdinfo, 2126 .setattr = proc_setattr, 2127 }; 2128 2129 2130 static struct dentry *proc_pident_instantiate(struct inode *dir, 2131 struct dentry *dentry, struct task_struct *task, const void *ptr) 2132 { 2133 const struct pid_entry *p = ptr; 2134 struct inode *inode; 2135 struct proc_inode *ei; 2136 struct dentry *error = ERR_PTR(-ENOENT); 2137 2138 inode = proc_pid_make_inode(dir->i_sb, task); 2139 if (!inode) 2140 goto out; 2141 2142 ei = PROC_I(inode); 2143 inode->i_mode = p->mode; 2144 if (S_ISDIR(inode->i_mode)) 2145 inode->i_nlink = 2; /* Use getattr to fix if necessary */ 2146 if (p->iop) 2147 inode->i_op = p->iop; 2148 if (p->fop) 2149 inode->i_fop = p->fop; 2150 ei->op = p->op; 2151 dentry->d_op = &pid_dentry_operations; 2152 d_add(dentry, inode); 2153 /* Close the race of the process dying before we return the dentry */ 2154 if (pid_revalidate(dentry, NULL)) 2155 error = NULL; 2156 out: 2157 return error; 2158 } 2159 2160 static struct dentry *proc_pident_lookup(struct inode *dir, 2161 struct dentry *dentry, 2162 const struct pid_entry *ents, 2163 unsigned int nents) 2164 { 2165 struct dentry *error; 2166 struct task_struct *task = get_proc_task(dir); 2167 const struct pid_entry *p, *last; 2168 2169 error = ERR_PTR(-ENOENT); 2170 2171 if (!task) 2172 goto out_no_task; 2173 2174 /* 2175 * Yes, it does not scale. And it should not. Don't add 2176 * new entries into /proc/<tgid>/ without very good reasons. 2177 */ 2178 last = &ents[nents - 1]; 2179 for (p = ents; p <= last; p++) { 2180 if (p->len != dentry->d_name.len) 2181 continue; 2182 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2183 break; 2184 } 2185 if (p > last) 2186 goto out; 2187 2188 error = proc_pident_instantiate(dir, dentry, task, p); 2189 out: 2190 put_task_struct(task); 2191 out_no_task: 2192 return error; 2193 } 2194 2195 static int proc_pident_fill_cache(struct file *filp, void *dirent, 2196 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2197 { 2198 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2199 proc_pident_instantiate, task, p); 2200 } 2201 2202 static int proc_pident_readdir(struct file *filp, 2203 void *dirent, filldir_t filldir, 2204 const struct pid_entry *ents, unsigned int nents) 2205 { 2206 int i; 2207 struct dentry *dentry = filp->f_path.dentry; 2208 struct inode *inode = dentry->d_inode; 2209 struct task_struct *task = get_proc_task(inode); 2210 const struct pid_entry *p, *last; 2211 ino_t ino; 2212 int ret; 2213 2214 ret = -ENOENT; 2215 if (!task) 2216 goto out_no_task; 2217 2218 ret = 0; 2219 i = filp->f_pos; 2220 switch (i) { 2221 case 0: 2222 ino = inode->i_ino; 2223 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 2224 goto out; 2225 i++; 2226 filp->f_pos++; 2227 /* fall through */ 2228 case 1: 2229 ino = parent_ino(dentry); 2230 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 2231 goto out; 2232 i++; 2233 filp->f_pos++; 2234 /* fall through */ 2235 default: 2236 i -= 2; 2237 if (i >= nents) { 2238 ret = 1; 2239 goto out; 2240 } 2241 p = ents + i; 2242 last = &ents[nents - 1]; 2243 while (p <= last) { 2244 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2245 goto out; 2246 filp->f_pos++; 2247 p++; 2248 } 2249 } 2250 2251 ret = 1; 2252 out: 2253 put_task_struct(task); 2254 out_no_task: 2255 return ret; 2256 } 2257 2258 #ifdef CONFIG_SECURITY 2259 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2260 size_t count, loff_t *ppos) 2261 { 2262 struct inode * inode = file->f_path.dentry->d_inode; 2263 char *p = NULL; 2264 ssize_t length; 2265 struct task_struct *task = get_proc_task(inode); 2266 2267 if (!task) 2268 return -ESRCH; 2269 2270 length = security_getprocattr(task, 2271 (char*)file->f_path.dentry->d_name.name, 2272 &p); 2273 put_task_struct(task); 2274 if (length > 0) 2275 length = simple_read_from_buffer(buf, count, ppos, p, length); 2276 kfree(p); 2277 return length; 2278 } 2279 2280 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2281 size_t count, loff_t *ppos) 2282 { 2283 struct inode * inode = file->f_path.dentry->d_inode; 2284 char *page; 2285 ssize_t length; 2286 struct task_struct *task = get_proc_task(inode); 2287 2288 length = -ESRCH; 2289 if (!task) 2290 goto out_no_task; 2291 if (count > PAGE_SIZE) 2292 count = PAGE_SIZE; 2293 2294 /* No partial writes. */ 2295 length = -EINVAL; 2296 if (*ppos != 0) 2297 goto out; 2298 2299 length = -ENOMEM; 2300 page = (char*)__get_free_page(GFP_TEMPORARY); 2301 if (!page) 2302 goto out; 2303 2304 length = -EFAULT; 2305 if (copy_from_user(page, buf, count)) 2306 goto out_free; 2307 2308 /* Guard against adverse ptrace interaction */ 2309 length = mutex_lock_interruptible(&task->cred_guard_mutex); 2310 if (length < 0) 2311 goto out_free; 2312 2313 length = security_setprocattr(task, 2314 (char*)file->f_path.dentry->d_name.name, 2315 (void*)page, count); 2316 mutex_unlock(&task->cred_guard_mutex); 2317 out_free: 2318 free_page((unsigned long) page); 2319 out: 2320 put_task_struct(task); 2321 out_no_task: 2322 return length; 2323 } 2324 2325 static const struct file_operations proc_pid_attr_operations = { 2326 .read = proc_pid_attr_read, 2327 .write = proc_pid_attr_write, 2328 .llseek = generic_file_llseek, 2329 }; 2330 2331 static const struct pid_entry attr_dir_stuff[] = { 2332 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2333 REG("prev", S_IRUGO, proc_pid_attr_operations), 2334 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2335 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2336 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2337 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2338 }; 2339 2340 static int proc_attr_dir_readdir(struct file * filp, 2341 void * dirent, filldir_t filldir) 2342 { 2343 return proc_pident_readdir(filp,dirent,filldir, 2344 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2345 } 2346 2347 static const struct file_operations proc_attr_dir_operations = { 2348 .read = generic_read_dir, 2349 .readdir = proc_attr_dir_readdir, 2350 .llseek = default_llseek, 2351 }; 2352 2353 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2354 struct dentry *dentry, struct nameidata *nd) 2355 { 2356 return proc_pident_lookup(dir, dentry, 2357 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2358 } 2359 2360 static const struct inode_operations proc_attr_dir_inode_operations = { 2361 .lookup = proc_attr_dir_lookup, 2362 .getattr = pid_getattr, 2363 .setattr = proc_setattr, 2364 }; 2365 2366 #endif 2367 2368 #ifdef CONFIG_ELF_CORE 2369 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2370 size_t count, loff_t *ppos) 2371 { 2372 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2373 struct mm_struct *mm; 2374 char buffer[PROC_NUMBUF]; 2375 size_t len; 2376 int ret; 2377 2378 if (!task) 2379 return -ESRCH; 2380 2381 ret = 0; 2382 mm = get_task_mm(task); 2383 if (mm) { 2384 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2385 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2386 MMF_DUMP_FILTER_SHIFT)); 2387 mmput(mm); 2388 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2389 } 2390 2391 put_task_struct(task); 2392 2393 return ret; 2394 } 2395 2396 static ssize_t proc_coredump_filter_write(struct file *file, 2397 const char __user *buf, 2398 size_t count, 2399 loff_t *ppos) 2400 { 2401 struct task_struct *task; 2402 struct mm_struct *mm; 2403 char buffer[PROC_NUMBUF], *end; 2404 unsigned int val; 2405 int ret; 2406 int i; 2407 unsigned long mask; 2408 2409 ret = -EFAULT; 2410 memset(buffer, 0, sizeof(buffer)); 2411 if (count > sizeof(buffer) - 1) 2412 count = sizeof(buffer) - 1; 2413 if (copy_from_user(buffer, buf, count)) 2414 goto out_no_task; 2415 2416 ret = -EINVAL; 2417 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2418 if (*end == '\n') 2419 end++; 2420 if (end - buffer == 0) 2421 goto out_no_task; 2422 2423 ret = -ESRCH; 2424 task = get_proc_task(file->f_dentry->d_inode); 2425 if (!task) 2426 goto out_no_task; 2427 2428 ret = end - buffer; 2429 mm = get_task_mm(task); 2430 if (!mm) 2431 goto out_no_mm; 2432 2433 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2434 if (val & mask) 2435 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2436 else 2437 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2438 } 2439 2440 mmput(mm); 2441 out_no_mm: 2442 put_task_struct(task); 2443 out_no_task: 2444 return ret; 2445 } 2446 2447 static const struct file_operations proc_coredump_filter_operations = { 2448 .read = proc_coredump_filter_read, 2449 .write = proc_coredump_filter_write, 2450 .llseek = generic_file_llseek, 2451 }; 2452 #endif 2453 2454 /* 2455 * /proc/self: 2456 */ 2457 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2458 int buflen) 2459 { 2460 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2461 pid_t tgid = task_tgid_nr_ns(current, ns); 2462 char tmp[PROC_NUMBUF]; 2463 if (!tgid) 2464 return -ENOENT; 2465 sprintf(tmp, "%d", tgid); 2466 return vfs_readlink(dentry,buffer,buflen,tmp); 2467 } 2468 2469 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2470 { 2471 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2472 pid_t tgid = task_tgid_nr_ns(current, ns); 2473 char *name = ERR_PTR(-ENOENT); 2474 if (tgid) { 2475 name = __getname(); 2476 if (!name) 2477 name = ERR_PTR(-ENOMEM); 2478 else 2479 sprintf(name, "%d", tgid); 2480 } 2481 nd_set_link(nd, name); 2482 return NULL; 2483 } 2484 2485 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd, 2486 void *cookie) 2487 { 2488 char *s = nd_get_link(nd); 2489 if (!IS_ERR(s)) 2490 __putname(s); 2491 } 2492 2493 static const struct inode_operations proc_self_inode_operations = { 2494 .readlink = proc_self_readlink, 2495 .follow_link = proc_self_follow_link, 2496 .put_link = proc_self_put_link, 2497 }; 2498 2499 /* 2500 * proc base 2501 * 2502 * These are the directory entries in the root directory of /proc 2503 * that properly belong to the /proc filesystem, as they describe 2504 * describe something that is process related. 2505 */ 2506 static const struct pid_entry proc_base_stuff[] = { 2507 NOD("self", S_IFLNK|S_IRWXUGO, 2508 &proc_self_inode_operations, NULL, {}), 2509 }; 2510 2511 /* 2512 * Exceptional case: normally we are not allowed to unhash a busy 2513 * directory. In this case, however, we can do it - no aliasing problems 2514 * due to the way we treat inodes. 2515 */ 2516 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) 2517 { 2518 struct inode *inode = dentry->d_inode; 2519 struct task_struct *task = get_proc_task(inode); 2520 if (task) { 2521 put_task_struct(task); 2522 return 1; 2523 } 2524 d_drop(dentry); 2525 return 0; 2526 } 2527 2528 static const struct dentry_operations proc_base_dentry_operations = 2529 { 2530 .d_revalidate = proc_base_revalidate, 2531 .d_delete = pid_delete_dentry, 2532 }; 2533 2534 static struct dentry *proc_base_instantiate(struct inode *dir, 2535 struct dentry *dentry, struct task_struct *task, const void *ptr) 2536 { 2537 const struct pid_entry *p = ptr; 2538 struct inode *inode; 2539 struct proc_inode *ei; 2540 struct dentry *error; 2541 2542 /* Allocate the inode */ 2543 error = ERR_PTR(-ENOMEM); 2544 inode = new_inode(dir->i_sb); 2545 if (!inode) 2546 goto out; 2547 2548 /* Initialize the inode */ 2549 ei = PROC_I(inode); 2550 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2551 2552 /* 2553 * grab the reference to the task. 2554 */ 2555 ei->pid = get_task_pid(task, PIDTYPE_PID); 2556 if (!ei->pid) 2557 goto out_iput; 2558 2559 inode->i_mode = p->mode; 2560 if (S_ISDIR(inode->i_mode)) 2561 inode->i_nlink = 2; 2562 if (S_ISLNK(inode->i_mode)) 2563 inode->i_size = 64; 2564 if (p->iop) 2565 inode->i_op = p->iop; 2566 if (p->fop) 2567 inode->i_fop = p->fop; 2568 ei->op = p->op; 2569 dentry->d_op = &proc_base_dentry_operations; 2570 d_add(dentry, inode); 2571 error = NULL; 2572 out: 2573 return error; 2574 out_iput: 2575 iput(inode); 2576 goto out; 2577 } 2578 2579 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2580 { 2581 struct dentry *error; 2582 struct task_struct *task = get_proc_task(dir); 2583 const struct pid_entry *p, *last; 2584 2585 error = ERR_PTR(-ENOENT); 2586 2587 if (!task) 2588 goto out_no_task; 2589 2590 /* Lookup the directory entry */ 2591 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2592 for (p = proc_base_stuff; p <= last; p++) { 2593 if (p->len != dentry->d_name.len) 2594 continue; 2595 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2596 break; 2597 } 2598 if (p > last) 2599 goto out; 2600 2601 error = proc_base_instantiate(dir, dentry, task, p); 2602 2603 out: 2604 put_task_struct(task); 2605 out_no_task: 2606 return error; 2607 } 2608 2609 static int proc_base_fill_cache(struct file *filp, void *dirent, 2610 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2611 { 2612 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2613 proc_base_instantiate, task, p); 2614 } 2615 2616 #ifdef CONFIG_TASK_IO_ACCOUNTING 2617 static int do_io_accounting(struct task_struct *task, char *buffer, int whole) 2618 { 2619 struct task_io_accounting acct = task->ioac; 2620 unsigned long flags; 2621 2622 if (whole && lock_task_sighand(task, &flags)) { 2623 struct task_struct *t = task; 2624 2625 task_io_accounting_add(&acct, &task->signal->ioac); 2626 while_each_thread(task, t) 2627 task_io_accounting_add(&acct, &t->ioac); 2628 2629 unlock_task_sighand(task, &flags); 2630 } 2631 return sprintf(buffer, 2632 "rchar: %llu\n" 2633 "wchar: %llu\n" 2634 "syscr: %llu\n" 2635 "syscw: %llu\n" 2636 "read_bytes: %llu\n" 2637 "write_bytes: %llu\n" 2638 "cancelled_write_bytes: %llu\n", 2639 (unsigned long long)acct.rchar, 2640 (unsigned long long)acct.wchar, 2641 (unsigned long long)acct.syscr, 2642 (unsigned long long)acct.syscw, 2643 (unsigned long long)acct.read_bytes, 2644 (unsigned long long)acct.write_bytes, 2645 (unsigned long long)acct.cancelled_write_bytes); 2646 } 2647 2648 static int proc_tid_io_accounting(struct task_struct *task, char *buffer) 2649 { 2650 return do_io_accounting(task, buffer, 0); 2651 } 2652 2653 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer) 2654 { 2655 return do_io_accounting(task, buffer, 1); 2656 } 2657 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2658 2659 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2660 struct pid *pid, struct task_struct *task) 2661 { 2662 seq_printf(m, "%08x\n", task->personality); 2663 return 0; 2664 } 2665 2666 /* 2667 * Thread groups 2668 */ 2669 static const struct file_operations proc_task_operations; 2670 static const struct inode_operations proc_task_inode_operations; 2671 2672 static const struct pid_entry tgid_base_stuff[] = { 2673 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2674 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2675 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2676 #ifdef CONFIG_NET 2677 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2678 #endif 2679 REG("environ", S_IRUSR, proc_environ_operations), 2680 INF("auxv", S_IRUSR, proc_pid_auxv), 2681 ONE("status", S_IRUGO, proc_pid_status), 2682 ONE("personality", S_IRUSR, proc_pid_personality), 2683 INF("limits", S_IRUGO, proc_pid_limits), 2684 #ifdef CONFIG_SCHED_DEBUG 2685 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2686 #endif 2687 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2688 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2689 INF("syscall", S_IRUSR, proc_pid_syscall), 2690 #endif 2691 INF("cmdline", S_IRUGO, proc_pid_cmdline), 2692 ONE("stat", S_IRUGO, proc_tgid_stat), 2693 ONE("statm", S_IRUGO, proc_pid_statm), 2694 REG("maps", S_IRUGO, proc_maps_operations), 2695 #ifdef CONFIG_NUMA 2696 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 2697 #endif 2698 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2699 LNK("cwd", proc_cwd_link), 2700 LNK("root", proc_root_link), 2701 LNK("exe", proc_exe_link), 2702 REG("mounts", S_IRUGO, proc_mounts_operations), 2703 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2704 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2705 #ifdef CONFIG_PROC_PAGE_MONITOR 2706 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2707 REG("smaps", S_IRUGO, proc_smaps_operations), 2708 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2709 #endif 2710 #ifdef CONFIG_SECURITY 2711 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2712 #endif 2713 #ifdef CONFIG_KALLSYMS 2714 INF("wchan", S_IRUGO, proc_pid_wchan), 2715 #endif 2716 #ifdef CONFIG_STACKTRACE 2717 ONE("stack", S_IRUSR, proc_pid_stack), 2718 #endif 2719 #ifdef CONFIG_SCHEDSTATS 2720 INF("schedstat", S_IRUGO, proc_pid_schedstat), 2721 #endif 2722 #ifdef CONFIG_LATENCYTOP 2723 REG("latency", S_IRUGO, proc_lstats_operations), 2724 #endif 2725 #ifdef CONFIG_PROC_PID_CPUSET 2726 REG("cpuset", S_IRUGO, proc_cpuset_operations), 2727 #endif 2728 #ifdef CONFIG_CGROUPS 2729 REG("cgroup", S_IRUGO, proc_cgroup_operations), 2730 #endif 2731 INF("oom_score", S_IRUGO, proc_oom_score), 2732 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 2733 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2734 #ifdef CONFIG_AUDITSYSCALL 2735 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2736 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2737 #endif 2738 #ifdef CONFIG_FAULT_INJECTION 2739 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2740 #endif 2741 #ifdef CONFIG_ELF_CORE 2742 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2743 #endif 2744 #ifdef CONFIG_TASK_IO_ACCOUNTING 2745 INF("io", S_IRUGO, proc_tgid_io_accounting), 2746 #endif 2747 }; 2748 2749 static int proc_tgid_base_readdir(struct file * filp, 2750 void * dirent, filldir_t filldir) 2751 { 2752 return proc_pident_readdir(filp,dirent,filldir, 2753 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2754 } 2755 2756 static const struct file_operations proc_tgid_base_operations = { 2757 .read = generic_read_dir, 2758 .readdir = proc_tgid_base_readdir, 2759 .llseek = default_llseek, 2760 }; 2761 2762 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2763 return proc_pident_lookup(dir, dentry, 2764 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2765 } 2766 2767 static const struct inode_operations proc_tgid_base_inode_operations = { 2768 .lookup = proc_tgid_base_lookup, 2769 .getattr = pid_getattr, 2770 .setattr = proc_setattr, 2771 }; 2772 2773 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2774 { 2775 struct dentry *dentry, *leader, *dir; 2776 char buf[PROC_NUMBUF]; 2777 struct qstr name; 2778 2779 name.name = buf; 2780 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2781 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2782 if (dentry) { 2783 shrink_dcache_parent(dentry); 2784 d_drop(dentry); 2785 dput(dentry); 2786 } 2787 2788 name.name = buf; 2789 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2790 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2791 if (!leader) 2792 goto out; 2793 2794 name.name = "task"; 2795 name.len = strlen(name.name); 2796 dir = d_hash_and_lookup(leader, &name); 2797 if (!dir) 2798 goto out_put_leader; 2799 2800 name.name = buf; 2801 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2802 dentry = d_hash_and_lookup(dir, &name); 2803 if (dentry) { 2804 shrink_dcache_parent(dentry); 2805 d_drop(dentry); 2806 dput(dentry); 2807 } 2808 2809 dput(dir); 2810 out_put_leader: 2811 dput(leader); 2812 out: 2813 return; 2814 } 2815 2816 /** 2817 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2818 * @task: task that should be flushed. 2819 * 2820 * When flushing dentries from proc, one needs to flush them from global 2821 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2822 * in. This call is supposed to do all of this job. 2823 * 2824 * Looks in the dcache for 2825 * /proc/@pid 2826 * /proc/@tgid/task/@pid 2827 * if either directory is present flushes it and all of it'ts children 2828 * from the dcache. 2829 * 2830 * It is safe and reasonable to cache /proc entries for a task until 2831 * that task exits. After that they just clog up the dcache with 2832 * useless entries, possibly causing useful dcache entries to be 2833 * flushed instead. This routine is proved to flush those useless 2834 * dcache entries at process exit time. 2835 * 2836 * NOTE: This routine is just an optimization so it does not guarantee 2837 * that no dcache entries will exist at process exit time it 2838 * just makes it very unlikely that any will persist. 2839 */ 2840 2841 void proc_flush_task(struct task_struct *task) 2842 { 2843 int i; 2844 struct pid *pid, *tgid; 2845 struct upid *upid; 2846 2847 pid = task_pid(task); 2848 tgid = task_tgid(task); 2849 2850 for (i = 0; i <= pid->level; i++) { 2851 upid = &pid->numbers[i]; 2852 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 2853 tgid->numbers[i].nr); 2854 } 2855 2856 upid = &pid->numbers[pid->level]; 2857 if (upid->nr == 1) 2858 pid_ns_release_proc(upid->ns); 2859 } 2860 2861 static struct dentry *proc_pid_instantiate(struct inode *dir, 2862 struct dentry * dentry, 2863 struct task_struct *task, const void *ptr) 2864 { 2865 struct dentry *error = ERR_PTR(-ENOENT); 2866 struct inode *inode; 2867 2868 inode = proc_pid_make_inode(dir->i_sb, task); 2869 if (!inode) 2870 goto out; 2871 2872 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2873 inode->i_op = &proc_tgid_base_inode_operations; 2874 inode->i_fop = &proc_tgid_base_operations; 2875 inode->i_flags|=S_IMMUTABLE; 2876 2877 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff, 2878 ARRAY_SIZE(tgid_base_stuff)); 2879 2880 dentry->d_op = &pid_dentry_operations; 2881 2882 d_add(dentry, inode); 2883 /* Close the race of the process dying before we return the dentry */ 2884 if (pid_revalidate(dentry, NULL)) 2885 error = NULL; 2886 out: 2887 return error; 2888 } 2889 2890 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2891 { 2892 struct dentry *result; 2893 struct task_struct *task; 2894 unsigned tgid; 2895 struct pid_namespace *ns; 2896 2897 result = proc_base_lookup(dir, dentry); 2898 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 2899 goto out; 2900 2901 tgid = name_to_int(dentry); 2902 if (tgid == ~0U) 2903 goto out; 2904 2905 ns = dentry->d_sb->s_fs_info; 2906 rcu_read_lock(); 2907 task = find_task_by_pid_ns(tgid, ns); 2908 if (task) 2909 get_task_struct(task); 2910 rcu_read_unlock(); 2911 if (!task) 2912 goto out; 2913 2914 result = proc_pid_instantiate(dir, dentry, task, NULL); 2915 put_task_struct(task); 2916 out: 2917 return result; 2918 } 2919 2920 /* 2921 * Find the first task with tgid >= tgid 2922 * 2923 */ 2924 struct tgid_iter { 2925 unsigned int tgid; 2926 struct task_struct *task; 2927 }; 2928 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 2929 { 2930 struct pid *pid; 2931 2932 if (iter.task) 2933 put_task_struct(iter.task); 2934 rcu_read_lock(); 2935 retry: 2936 iter.task = NULL; 2937 pid = find_ge_pid(iter.tgid, ns); 2938 if (pid) { 2939 iter.tgid = pid_nr_ns(pid, ns); 2940 iter.task = pid_task(pid, PIDTYPE_PID); 2941 /* What we to know is if the pid we have find is the 2942 * pid of a thread_group_leader. Testing for task 2943 * being a thread_group_leader is the obvious thing 2944 * todo but there is a window when it fails, due to 2945 * the pid transfer logic in de_thread. 2946 * 2947 * So we perform the straight forward test of seeing 2948 * if the pid we have found is the pid of a thread 2949 * group leader, and don't worry if the task we have 2950 * found doesn't happen to be a thread group leader. 2951 * As we don't care in the case of readdir. 2952 */ 2953 if (!iter.task || !has_group_leader_pid(iter.task)) { 2954 iter.tgid += 1; 2955 goto retry; 2956 } 2957 get_task_struct(iter.task); 2958 } 2959 rcu_read_unlock(); 2960 return iter; 2961 } 2962 2963 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 2964 2965 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2966 struct tgid_iter iter) 2967 { 2968 char name[PROC_NUMBUF]; 2969 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 2970 return proc_fill_cache(filp, dirent, filldir, name, len, 2971 proc_pid_instantiate, iter.task, NULL); 2972 } 2973 2974 /* for the /proc/ directory itself, after non-process stuff has been done */ 2975 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 2976 { 2977 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; 2978 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode); 2979 struct tgid_iter iter; 2980 struct pid_namespace *ns; 2981 2982 if (!reaper) 2983 goto out_no_task; 2984 2985 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 2986 const struct pid_entry *p = &proc_base_stuff[nr]; 2987 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 2988 goto out; 2989 } 2990 2991 ns = filp->f_dentry->d_sb->s_fs_info; 2992 iter.task = NULL; 2993 iter.tgid = filp->f_pos - TGID_OFFSET; 2994 for (iter = next_tgid(ns, iter); 2995 iter.task; 2996 iter.tgid += 1, iter = next_tgid(ns, iter)) { 2997 filp->f_pos = iter.tgid + TGID_OFFSET; 2998 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) { 2999 put_task_struct(iter.task); 3000 goto out; 3001 } 3002 } 3003 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 3004 out: 3005 put_task_struct(reaper); 3006 out_no_task: 3007 return 0; 3008 } 3009 3010 /* 3011 * Tasks 3012 */ 3013 static const struct pid_entry tid_base_stuff[] = { 3014 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3015 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3016 REG("environ", S_IRUSR, proc_environ_operations), 3017 INF("auxv", S_IRUSR, proc_pid_auxv), 3018 ONE("status", S_IRUGO, proc_pid_status), 3019 ONE("personality", S_IRUSR, proc_pid_personality), 3020 INF("limits", S_IRUGO, proc_pid_limits), 3021 #ifdef CONFIG_SCHED_DEBUG 3022 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3023 #endif 3024 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3025 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3026 INF("syscall", S_IRUSR, proc_pid_syscall), 3027 #endif 3028 INF("cmdline", S_IRUGO, proc_pid_cmdline), 3029 ONE("stat", S_IRUGO, proc_tid_stat), 3030 ONE("statm", S_IRUGO, proc_pid_statm), 3031 REG("maps", S_IRUGO, proc_maps_operations), 3032 #ifdef CONFIG_NUMA 3033 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 3034 #endif 3035 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3036 LNK("cwd", proc_cwd_link), 3037 LNK("root", proc_root_link), 3038 LNK("exe", proc_exe_link), 3039 REG("mounts", S_IRUGO, proc_mounts_operations), 3040 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3041 #ifdef CONFIG_PROC_PAGE_MONITOR 3042 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3043 REG("smaps", S_IRUGO, proc_smaps_operations), 3044 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3045 #endif 3046 #ifdef CONFIG_SECURITY 3047 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3048 #endif 3049 #ifdef CONFIG_KALLSYMS 3050 INF("wchan", S_IRUGO, proc_pid_wchan), 3051 #endif 3052 #ifdef CONFIG_STACKTRACE 3053 ONE("stack", S_IRUSR, proc_pid_stack), 3054 #endif 3055 #ifdef CONFIG_SCHEDSTATS 3056 INF("schedstat", S_IRUGO, proc_pid_schedstat), 3057 #endif 3058 #ifdef CONFIG_LATENCYTOP 3059 REG("latency", S_IRUGO, proc_lstats_operations), 3060 #endif 3061 #ifdef CONFIG_PROC_PID_CPUSET 3062 REG("cpuset", S_IRUGO, proc_cpuset_operations), 3063 #endif 3064 #ifdef CONFIG_CGROUPS 3065 REG("cgroup", S_IRUGO, proc_cgroup_operations), 3066 #endif 3067 INF("oom_score", S_IRUGO, proc_oom_score), 3068 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 3069 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3070 #ifdef CONFIG_AUDITSYSCALL 3071 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3072 REG("sessionid", S_IRUSR, proc_sessionid_operations), 3073 #endif 3074 #ifdef CONFIG_FAULT_INJECTION 3075 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3076 #endif 3077 #ifdef CONFIG_TASK_IO_ACCOUNTING 3078 INF("io", S_IRUGO, proc_tid_io_accounting), 3079 #endif 3080 }; 3081 3082 static int proc_tid_base_readdir(struct file * filp, 3083 void * dirent, filldir_t filldir) 3084 { 3085 return proc_pident_readdir(filp,dirent,filldir, 3086 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 3087 } 3088 3089 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 3090 return proc_pident_lookup(dir, dentry, 3091 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3092 } 3093 3094 static const struct file_operations proc_tid_base_operations = { 3095 .read = generic_read_dir, 3096 .readdir = proc_tid_base_readdir, 3097 .llseek = default_llseek, 3098 }; 3099 3100 static const struct inode_operations proc_tid_base_inode_operations = { 3101 .lookup = proc_tid_base_lookup, 3102 .getattr = pid_getattr, 3103 .setattr = proc_setattr, 3104 }; 3105 3106 static struct dentry *proc_task_instantiate(struct inode *dir, 3107 struct dentry *dentry, struct task_struct *task, const void *ptr) 3108 { 3109 struct dentry *error = ERR_PTR(-ENOENT); 3110 struct inode *inode; 3111 inode = proc_pid_make_inode(dir->i_sb, task); 3112 3113 if (!inode) 3114 goto out; 3115 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3116 inode->i_op = &proc_tid_base_inode_operations; 3117 inode->i_fop = &proc_tid_base_operations; 3118 inode->i_flags|=S_IMMUTABLE; 3119 3120 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff, 3121 ARRAY_SIZE(tid_base_stuff)); 3122 3123 dentry->d_op = &pid_dentry_operations; 3124 3125 d_add(dentry, inode); 3126 /* Close the race of the process dying before we return the dentry */ 3127 if (pid_revalidate(dentry, NULL)) 3128 error = NULL; 3129 out: 3130 return error; 3131 } 3132 3133 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 3134 { 3135 struct dentry *result = ERR_PTR(-ENOENT); 3136 struct task_struct *task; 3137 struct task_struct *leader = get_proc_task(dir); 3138 unsigned tid; 3139 struct pid_namespace *ns; 3140 3141 if (!leader) 3142 goto out_no_task; 3143 3144 tid = name_to_int(dentry); 3145 if (tid == ~0U) 3146 goto out; 3147 3148 ns = dentry->d_sb->s_fs_info; 3149 rcu_read_lock(); 3150 task = find_task_by_pid_ns(tid, ns); 3151 if (task) 3152 get_task_struct(task); 3153 rcu_read_unlock(); 3154 if (!task) 3155 goto out; 3156 if (!same_thread_group(leader, task)) 3157 goto out_drop_task; 3158 3159 result = proc_task_instantiate(dir, dentry, task, NULL); 3160 out_drop_task: 3161 put_task_struct(task); 3162 out: 3163 put_task_struct(leader); 3164 out_no_task: 3165 return result; 3166 } 3167 3168 /* 3169 * Find the first tid of a thread group to return to user space. 3170 * 3171 * Usually this is just the thread group leader, but if the users 3172 * buffer was too small or there was a seek into the middle of the 3173 * directory we have more work todo. 3174 * 3175 * In the case of a short read we start with find_task_by_pid. 3176 * 3177 * In the case of a seek we start with the leader and walk nr 3178 * threads past it. 3179 */ 3180 static struct task_struct *first_tid(struct task_struct *leader, 3181 int tid, int nr, struct pid_namespace *ns) 3182 { 3183 struct task_struct *pos; 3184 3185 rcu_read_lock(); 3186 /* Attempt to start with the pid of a thread */ 3187 if (tid && (nr > 0)) { 3188 pos = find_task_by_pid_ns(tid, ns); 3189 if (pos && (pos->group_leader == leader)) 3190 goto found; 3191 } 3192 3193 /* If nr exceeds the number of threads there is nothing todo */ 3194 pos = NULL; 3195 if (nr && nr >= get_nr_threads(leader)) 3196 goto out; 3197 3198 /* If we haven't found our starting place yet start 3199 * with the leader and walk nr threads forward. 3200 */ 3201 for (pos = leader; nr > 0; --nr) { 3202 pos = next_thread(pos); 3203 if (pos == leader) { 3204 pos = NULL; 3205 goto out; 3206 } 3207 } 3208 found: 3209 get_task_struct(pos); 3210 out: 3211 rcu_read_unlock(); 3212 return pos; 3213 } 3214 3215 /* 3216 * Find the next thread in the thread list. 3217 * Return NULL if there is an error or no next thread. 3218 * 3219 * The reference to the input task_struct is released. 3220 */ 3221 static struct task_struct *next_tid(struct task_struct *start) 3222 { 3223 struct task_struct *pos = NULL; 3224 rcu_read_lock(); 3225 if (pid_alive(start)) { 3226 pos = next_thread(start); 3227 if (thread_group_leader(pos)) 3228 pos = NULL; 3229 else 3230 get_task_struct(pos); 3231 } 3232 rcu_read_unlock(); 3233 put_task_struct(start); 3234 return pos; 3235 } 3236 3237 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3238 struct task_struct *task, int tid) 3239 { 3240 char name[PROC_NUMBUF]; 3241 int len = snprintf(name, sizeof(name), "%d", tid); 3242 return proc_fill_cache(filp, dirent, filldir, name, len, 3243 proc_task_instantiate, task, NULL); 3244 } 3245 3246 /* for the /proc/TGID/task/ directories */ 3247 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 3248 { 3249 struct dentry *dentry = filp->f_path.dentry; 3250 struct inode *inode = dentry->d_inode; 3251 struct task_struct *leader = NULL; 3252 struct task_struct *task; 3253 int retval = -ENOENT; 3254 ino_t ino; 3255 int tid; 3256 struct pid_namespace *ns; 3257 3258 task = get_proc_task(inode); 3259 if (!task) 3260 goto out_no_task; 3261 rcu_read_lock(); 3262 if (pid_alive(task)) { 3263 leader = task->group_leader; 3264 get_task_struct(leader); 3265 } 3266 rcu_read_unlock(); 3267 put_task_struct(task); 3268 if (!leader) 3269 goto out_no_task; 3270 retval = 0; 3271 3272 switch ((unsigned long)filp->f_pos) { 3273 case 0: 3274 ino = inode->i_ino; 3275 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0) 3276 goto out; 3277 filp->f_pos++; 3278 /* fall through */ 3279 case 1: 3280 ino = parent_ino(dentry); 3281 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0) 3282 goto out; 3283 filp->f_pos++; 3284 /* fall through */ 3285 } 3286 3287 /* f_version caches the tgid value that the last readdir call couldn't 3288 * return. lseek aka telldir automagically resets f_version to 0. 3289 */ 3290 ns = filp->f_dentry->d_sb->s_fs_info; 3291 tid = (int)filp->f_version; 3292 filp->f_version = 0; 3293 for (task = first_tid(leader, tid, filp->f_pos - 2, ns); 3294 task; 3295 task = next_tid(task), filp->f_pos++) { 3296 tid = task_pid_nr_ns(task, ns); 3297 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 3298 /* returning this tgid failed, save it as the first 3299 * pid for the next readir call */ 3300 filp->f_version = (u64)tid; 3301 put_task_struct(task); 3302 break; 3303 } 3304 } 3305 out: 3306 put_task_struct(leader); 3307 out_no_task: 3308 return retval; 3309 } 3310 3311 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3312 { 3313 struct inode *inode = dentry->d_inode; 3314 struct task_struct *p = get_proc_task(inode); 3315 generic_fillattr(inode, stat); 3316 3317 if (p) { 3318 stat->nlink += get_nr_threads(p); 3319 put_task_struct(p); 3320 } 3321 3322 return 0; 3323 } 3324 3325 static const struct inode_operations proc_task_inode_operations = { 3326 .lookup = proc_task_lookup, 3327 .getattr = proc_task_getattr, 3328 .setattr = proc_setattr, 3329 }; 3330 3331 static const struct file_operations proc_task_operations = { 3332 .read = generic_read_dir, 3333 .readdir = proc_task_readdir, 3334 .llseek = default_llseek, 3335 }; 3336