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