1 /* 2 * linux/fs/proc/base.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 * 6 * proc base directory handling functions 7 * 8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part. 9 * Instead of using magical inumbers to determine the kind of object 10 * we allocate and fill in-core inodes upon lookup. They don't even 11 * go into icache. We cache the reference to task_struct upon lookup too. 12 * Eventually it should become a filesystem in its own. We don't use the 13 * rest of procfs anymore. 14 * 15 * 16 * Changelog: 17 * 17-Jan-2005 18 * Allan Bezerra 19 * Bruna Moreira <bruna.moreira@indt.org.br> 20 * Edjard Mota <edjard.mota@indt.org.br> 21 * Ilias Biris <ilias.biris@indt.org.br> 22 * Mauricio Lin <mauricio.lin@indt.org.br> 23 * 24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 25 * 26 * A new process specific entry (smaps) included in /proc. It shows the 27 * size of rss for each memory area. The maps entry lacks information 28 * about physical memory size (rss) for each mapped file, i.e., 29 * rss information for executables and library files. 30 * This additional information is useful for any tools that need to know 31 * about physical memory consumption for a process specific library. 32 * 33 * Changelog: 34 * 21-Feb-2005 35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT 36 * Pud inclusion in the page table walking. 37 * 38 * ChangeLog: 39 * 10-Mar-2005 40 * 10LE Instituto Nokia de Tecnologia - INdT: 41 * A better way to walks through the page table as suggested by Hugh Dickins. 42 * 43 * Simo Piiroinen <simo.piiroinen@nokia.com>: 44 * Smaps information related to shared, private, clean and dirty pages. 45 * 46 * Paul Mundt <paul.mundt@nokia.com>: 47 * Overall revision about smaps. 48 */ 49 50 #include <asm/uaccess.h> 51 52 #include <linux/errno.h> 53 #include <linux/time.h> 54 #include <linux/proc_fs.h> 55 #include <linux/stat.h> 56 #include <linux/task_io_accounting_ops.h> 57 #include <linux/init.h> 58 #include <linux/capability.h> 59 #include <linux/file.h> 60 #include <linux/fdtable.h> 61 #include <linux/string.h> 62 #include <linux/seq_file.h> 63 #include <linux/namei.h> 64 #include <linux/mnt_namespace.h> 65 #include <linux/mm.h> 66 #include <linux/swap.h> 67 #include <linux/rcupdate.h> 68 #include <linux/kallsyms.h> 69 #include <linux/stacktrace.h> 70 #include <linux/resource.h> 71 #include <linux/module.h> 72 #include <linux/mount.h> 73 #include <linux/security.h> 74 #include <linux/ptrace.h> 75 #include <linux/tracehook.h> 76 #include <linux/cgroup.h> 77 #include <linux/cpuset.h> 78 #include <linux/audit.h> 79 #include <linux/poll.h> 80 #include <linux/nsproxy.h> 81 #include <linux/oom.h> 82 #include <linux/elf.h> 83 #include <linux/pid_namespace.h> 84 #include <linux/fs_struct.h> 85 #include <linux/slab.h> 86 #include "internal.h" 87 88 /* NOTE: 89 * Implementing inode permission operations in /proc is almost 90 * certainly an error. Permission checks need to happen during 91 * each system call not at open time. The reason is that most of 92 * what we wish to check for permissions in /proc varies at runtime. 93 * 94 * The classic example of a problem is opening file descriptors 95 * in /proc for a task before it execs a suid executable. 96 */ 97 98 struct pid_entry { 99 char *name; 100 int len; 101 mode_t mode; 102 const struct inode_operations *iop; 103 const struct file_operations *fop; 104 union proc_op op; 105 }; 106 107 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 108 .name = (NAME), \ 109 .len = sizeof(NAME) - 1, \ 110 .mode = MODE, \ 111 .iop = IOP, \ 112 .fop = FOP, \ 113 .op = OP, \ 114 } 115 116 #define DIR(NAME, MODE, iops, fops) \ 117 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} ) 118 #define LNK(NAME, get_link) \ 119 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 120 &proc_pid_link_inode_operations, NULL, \ 121 { .proc_get_link = get_link } ) 122 #define REG(NAME, MODE, fops) \ 123 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {}) 124 #define INF(NAME, MODE, read) \ 125 NOD(NAME, (S_IFREG|(MODE)), \ 126 NULL, &proc_info_file_operations, \ 127 { .proc_read = read } ) 128 #define ONE(NAME, MODE, show) \ 129 NOD(NAME, (S_IFREG|(MODE)), \ 130 NULL, &proc_single_file_operations, \ 131 { .proc_show = show } ) 132 133 /* 134 * Count the number of hardlinks for the pid_entry table, excluding the . 135 * and .. links. 136 */ 137 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries, 138 unsigned int n) 139 { 140 unsigned int i; 141 unsigned int count; 142 143 count = 0; 144 for (i = 0; i < n; ++i) { 145 if (S_ISDIR(entries[i].mode)) 146 ++count; 147 } 148 149 return count; 150 } 151 152 static int get_task_root(struct task_struct *task, struct path *root) 153 { 154 int result = -ENOENT; 155 156 task_lock(task); 157 if (task->fs) { 158 get_fs_root(task->fs, root); 159 result = 0; 160 } 161 task_unlock(task); 162 return result; 163 } 164 165 static int proc_cwd_link(struct inode *inode, struct path *path) 166 { 167 struct task_struct *task = get_proc_task(inode); 168 int result = -ENOENT; 169 170 if (task) { 171 task_lock(task); 172 if (task->fs) { 173 get_fs_pwd(task->fs, path); 174 result = 0; 175 } 176 task_unlock(task); 177 put_task_struct(task); 178 } 179 return result; 180 } 181 182 static int proc_root_link(struct inode *inode, struct path *path) 183 { 184 struct task_struct *task = get_proc_task(inode); 185 int result = -ENOENT; 186 187 if (task) { 188 result = get_task_root(task, path); 189 put_task_struct(task); 190 } 191 return result; 192 } 193 194 /* 195 * Return zero if current may access user memory in @task, -error if not. 196 */ 197 static int check_mem_permission(struct task_struct *task) 198 { 199 /* 200 * A task can always look at itself, in case it chooses 201 * to use system calls instead of load instructions. 202 */ 203 if (task == current) 204 return 0; 205 206 /* 207 * If current is actively ptrace'ing, and would also be 208 * permitted to freshly attach with ptrace now, permit it. 209 */ 210 if (task_is_stopped_or_traced(task)) { 211 int match; 212 rcu_read_lock(); 213 match = (tracehook_tracer_task(task) == current); 214 rcu_read_unlock(); 215 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH)) 216 return 0; 217 } 218 219 /* 220 * Noone else is allowed. 221 */ 222 return -EPERM; 223 } 224 225 struct mm_struct *mm_for_maps(struct task_struct *task) 226 { 227 struct mm_struct *mm; 228 229 if (mutex_lock_killable(&task->signal->cred_guard_mutex)) 230 return NULL; 231 232 mm = get_task_mm(task); 233 if (mm && mm != current->mm && 234 !ptrace_may_access(task, PTRACE_MODE_READ)) { 235 mmput(mm); 236 mm = NULL; 237 } 238 mutex_unlock(&task->signal->cred_guard_mutex); 239 240 return mm; 241 } 242 243 static int proc_pid_cmdline(struct task_struct *task, char * buffer) 244 { 245 int res = 0; 246 unsigned int len; 247 struct mm_struct *mm = get_task_mm(task); 248 if (!mm) 249 goto out; 250 if (!mm->arg_end) 251 goto out_mm; /* Shh! No looking before we're done */ 252 253 len = mm->arg_end - mm->arg_start; 254 255 if (len > PAGE_SIZE) 256 len = PAGE_SIZE; 257 258 res = access_process_vm(task, mm->arg_start, buffer, len, 0); 259 260 // If the nul at the end of args has been overwritten, then 261 // assume application is using setproctitle(3). 262 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) { 263 len = strnlen(buffer, res); 264 if (len < res) { 265 res = len; 266 } else { 267 len = mm->env_end - mm->env_start; 268 if (len > PAGE_SIZE - res) 269 len = PAGE_SIZE - res; 270 res += access_process_vm(task, mm->env_start, buffer+res, len, 0); 271 res = strnlen(buffer, res); 272 } 273 } 274 out_mm: 275 mmput(mm); 276 out: 277 return res; 278 } 279 280 static int proc_pid_auxv(struct task_struct *task, char *buffer) 281 { 282 int res = 0; 283 struct mm_struct *mm = get_task_mm(task); 284 if (mm) { 285 unsigned int nwords = 0; 286 do { 287 nwords += 2; 288 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 289 res = nwords * sizeof(mm->saved_auxv[0]); 290 if (res > PAGE_SIZE) 291 res = PAGE_SIZE; 292 memcpy(buffer, mm->saved_auxv, res); 293 mmput(mm); 294 } 295 return res; 296 } 297 298 299 #ifdef CONFIG_KALLSYMS 300 /* 301 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 302 * Returns the resolved symbol. If that fails, simply return the address. 303 */ 304 static int proc_pid_wchan(struct task_struct *task, char *buffer) 305 { 306 unsigned long wchan; 307 char symname[KSYM_NAME_LEN]; 308 309 wchan = get_wchan(task); 310 311 if (lookup_symbol_name(wchan, symname) < 0) 312 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 313 return 0; 314 else 315 return sprintf(buffer, "%lu", wchan); 316 else 317 return sprintf(buffer, "%s", symname); 318 } 319 #endif /* CONFIG_KALLSYMS */ 320 321 #ifdef CONFIG_STACKTRACE 322 323 #define MAX_STACK_TRACE_DEPTH 64 324 325 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, 326 struct pid *pid, struct task_struct *task) 327 { 328 struct stack_trace trace; 329 unsigned long *entries; 330 int i; 331 332 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL); 333 if (!entries) 334 return -ENOMEM; 335 336 trace.nr_entries = 0; 337 trace.max_entries = MAX_STACK_TRACE_DEPTH; 338 trace.entries = entries; 339 trace.skip = 0; 340 save_stack_trace_tsk(task, &trace); 341 342 for (i = 0; i < trace.nr_entries; i++) { 343 seq_printf(m, "[<%p>] %pS\n", 344 (void *)entries[i], (void *)entries[i]); 345 } 346 kfree(entries); 347 348 return 0; 349 } 350 #endif 351 352 #ifdef CONFIG_SCHEDSTATS 353 /* 354 * Provides /proc/PID/schedstat 355 */ 356 static int proc_pid_schedstat(struct task_struct *task, char *buffer) 357 { 358 return sprintf(buffer, "%llu %llu %lu\n", 359 (unsigned long long)task->se.sum_exec_runtime, 360 (unsigned long long)task->sched_info.run_delay, 361 task->sched_info.pcount); 362 } 363 #endif 364 365 #ifdef CONFIG_LATENCYTOP 366 static int lstats_show_proc(struct seq_file *m, void *v) 367 { 368 int i; 369 struct inode *inode = m->private; 370 struct task_struct *task = get_proc_task(inode); 371 372 if (!task) 373 return -ESRCH; 374 seq_puts(m, "Latency Top version : v0.1\n"); 375 for (i = 0; i < 32; i++) { 376 if (task->latency_record[i].backtrace[0]) { 377 int q; 378 seq_printf(m, "%i %li %li ", 379 task->latency_record[i].count, 380 task->latency_record[i].time, 381 task->latency_record[i].max); 382 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 383 char sym[KSYM_SYMBOL_LEN]; 384 char *c; 385 if (!task->latency_record[i].backtrace[q]) 386 break; 387 if (task->latency_record[i].backtrace[q] == ULONG_MAX) 388 break; 389 sprint_symbol(sym, task->latency_record[i].backtrace[q]); 390 c = strchr(sym, '+'); 391 if (c) 392 *c = 0; 393 seq_printf(m, "%s ", sym); 394 } 395 seq_printf(m, "\n"); 396 } 397 398 } 399 put_task_struct(task); 400 return 0; 401 } 402 403 static int lstats_open(struct inode *inode, struct file *file) 404 { 405 return single_open(file, lstats_show_proc, inode); 406 } 407 408 static ssize_t lstats_write(struct file *file, const char __user *buf, 409 size_t count, loff_t *offs) 410 { 411 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 412 413 if (!task) 414 return -ESRCH; 415 clear_all_latency_tracing(task); 416 put_task_struct(task); 417 418 return count; 419 } 420 421 static const struct file_operations proc_lstats_operations = { 422 .open = lstats_open, 423 .read = seq_read, 424 .write = lstats_write, 425 .llseek = seq_lseek, 426 .release = single_release, 427 }; 428 429 #endif 430 431 static int proc_oom_score(struct task_struct *task, char *buffer) 432 { 433 unsigned long points = 0; 434 435 read_lock(&tasklist_lock); 436 if (pid_alive(task)) 437 points = oom_badness(task, NULL, NULL, 438 totalram_pages + total_swap_pages); 439 read_unlock(&tasklist_lock); 440 return sprintf(buffer, "%lu\n", points); 441 } 442 443 struct limit_names { 444 char *name; 445 char *unit; 446 }; 447 448 static const struct limit_names lnames[RLIM_NLIMITS] = { 449 [RLIMIT_CPU] = {"Max cpu time", "seconds"}, 450 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 451 [RLIMIT_DATA] = {"Max data size", "bytes"}, 452 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 453 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 454 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 455 [RLIMIT_NPROC] = {"Max processes", "processes"}, 456 [RLIMIT_NOFILE] = {"Max open files", "files"}, 457 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 458 [RLIMIT_AS] = {"Max address space", "bytes"}, 459 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 460 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 461 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 462 [RLIMIT_NICE] = {"Max nice priority", NULL}, 463 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 464 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"}, 465 }; 466 467 /* Display limits for a process */ 468 static int proc_pid_limits(struct task_struct *task, char *buffer) 469 { 470 unsigned int i; 471 int count = 0; 472 unsigned long flags; 473 char *bufptr = buffer; 474 475 struct rlimit rlim[RLIM_NLIMITS]; 476 477 if (!lock_task_sighand(task, &flags)) 478 return 0; 479 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 480 unlock_task_sighand(task, &flags); 481 482 /* 483 * print the file header 484 */ 485 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n", 486 "Limit", "Soft Limit", "Hard Limit", "Units"); 487 488 for (i = 0; i < RLIM_NLIMITS; i++) { 489 if (rlim[i].rlim_cur == RLIM_INFINITY) 490 count += sprintf(&bufptr[count], "%-25s %-20s ", 491 lnames[i].name, "unlimited"); 492 else 493 count += sprintf(&bufptr[count], "%-25s %-20lu ", 494 lnames[i].name, rlim[i].rlim_cur); 495 496 if (rlim[i].rlim_max == RLIM_INFINITY) 497 count += sprintf(&bufptr[count], "%-20s ", "unlimited"); 498 else 499 count += sprintf(&bufptr[count], "%-20lu ", 500 rlim[i].rlim_max); 501 502 if (lnames[i].unit) 503 count += sprintf(&bufptr[count], "%-10s\n", 504 lnames[i].unit); 505 else 506 count += sprintf(&bufptr[count], "\n"); 507 } 508 509 return count; 510 } 511 512 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 513 static int proc_pid_syscall(struct task_struct *task, char *buffer) 514 { 515 long nr; 516 unsigned long args[6], sp, pc; 517 518 if (task_current_syscall(task, &nr, args, 6, &sp, &pc)) 519 return sprintf(buffer, "running\n"); 520 521 if (nr < 0) 522 return sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc); 523 524 return sprintf(buffer, 525 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", 526 nr, 527 args[0], args[1], args[2], args[3], args[4], args[5], 528 sp, pc); 529 } 530 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 531 532 /************************************************************************/ 533 /* Here the fs part begins */ 534 /************************************************************************/ 535 536 /* permission checks */ 537 static int proc_fd_access_allowed(struct inode *inode) 538 { 539 struct task_struct *task; 540 int allowed = 0; 541 /* Allow access to a task's file descriptors if it is us or we 542 * may use ptrace attach to the process and find out that 543 * information. 544 */ 545 task = get_proc_task(inode); 546 if (task) { 547 allowed = ptrace_may_access(task, PTRACE_MODE_READ); 548 put_task_struct(task); 549 } 550 return allowed; 551 } 552 553 static int proc_setattr(struct dentry *dentry, struct iattr *attr) 554 { 555 int error; 556 struct inode *inode = dentry->d_inode; 557 558 if (attr->ia_valid & ATTR_MODE) 559 return -EPERM; 560 561 error = inode_change_ok(inode, attr); 562 if (error) 563 return error; 564 565 if ((attr->ia_valid & ATTR_SIZE) && 566 attr->ia_size != i_size_read(inode)) { 567 error = vmtruncate(inode, attr->ia_size); 568 if (error) 569 return error; 570 } 571 572 setattr_copy(inode, attr); 573 mark_inode_dirty(inode); 574 return 0; 575 } 576 577 static const struct inode_operations proc_def_inode_operations = { 578 .setattr = proc_setattr, 579 }; 580 581 static int mounts_open_common(struct inode *inode, struct file *file, 582 const struct seq_operations *op) 583 { 584 struct task_struct *task = get_proc_task(inode); 585 struct nsproxy *nsp; 586 struct mnt_namespace *ns = NULL; 587 struct path root; 588 struct proc_mounts *p; 589 int ret = -EINVAL; 590 591 if (task) { 592 rcu_read_lock(); 593 nsp = task_nsproxy(task); 594 if (nsp) { 595 ns = nsp->mnt_ns; 596 if (ns) 597 get_mnt_ns(ns); 598 } 599 rcu_read_unlock(); 600 if (ns && get_task_root(task, &root) == 0) 601 ret = 0; 602 put_task_struct(task); 603 } 604 605 if (!ns) 606 goto err; 607 if (ret) 608 goto err_put_ns; 609 610 ret = -ENOMEM; 611 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL); 612 if (!p) 613 goto err_put_path; 614 615 file->private_data = &p->m; 616 ret = seq_open(file, op); 617 if (ret) 618 goto err_free; 619 620 p->m.private = p; 621 p->ns = ns; 622 p->root = root; 623 p->event = ns->event; 624 625 return 0; 626 627 err_free: 628 kfree(p); 629 err_put_path: 630 path_put(&root); 631 err_put_ns: 632 put_mnt_ns(ns); 633 err: 634 return ret; 635 } 636 637 static int mounts_release(struct inode *inode, struct file *file) 638 { 639 struct proc_mounts *p = file->private_data; 640 path_put(&p->root); 641 put_mnt_ns(p->ns); 642 return seq_release(inode, file); 643 } 644 645 static unsigned mounts_poll(struct file *file, poll_table *wait) 646 { 647 struct proc_mounts *p = file->private_data; 648 unsigned res = POLLIN | POLLRDNORM; 649 650 poll_wait(file, &p->ns->poll, wait); 651 if (mnt_had_events(p)) 652 res |= POLLERR | POLLPRI; 653 654 return res; 655 } 656 657 static int mounts_open(struct inode *inode, struct file *file) 658 { 659 return mounts_open_common(inode, file, &mounts_op); 660 } 661 662 static const struct file_operations proc_mounts_operations = { 663 .open = mounts_open, 664 .read = seq_read, 665 .llseek = seq_lseek, 666 .release = mounts_release, 667 .poll = mounts_poll, 668 }; 669 670 static int mountinfo_open(struct inode *inode, struct file *file) 671 { 672 return mounts_open_common(inode, file, &mountinfo_op); 673 } 674 675 static const struct file_operations proc_mountinfo_operations = { 676 .open = mountinfo_open, 677 .read = seq_read, 678 .llseek = seq_lseek, 679 .release = mounts_release, 680 .poll = mounts_poll, 681 }; 682 683 static int mountstats_open(struct inode *inode, struct file *file) 684 { 685 return mounts_open_common(inode, file, &mountstats_op); 686 } 687 688 static const struct file_operations proc_mountstats_operations = { 689 .open = mountstats_open, 690 .read = seq_read, 691 .llseek = seq_lseek, 692 .release = mounts_release, 693 }; 694 695 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */ 696 697 static ssize_t proc_info_read(struct file * file, char __user * buf, 698 size_t count, loff_t *ppos) 699 { 700 struct inode * inode = file->f_path.dentry->d_inode; 701 unsigned long page; 702 ssize_t length; 703 struct task_struct *task = get_proc_task(inode); 704 705 length = -ESRCH; 706 if (!task) 707 goto out_no_task; 708 709 if (count > PROC_BLOCK_SIZE) 710 count = PROC_BLOCK_SIZE; 711 712 length = -ENOMEM; 713 if (!(page = __get_free_page(GFP_TEMPORARY))) 714 goto out; 715 716 length = PROC_I(inode)->op.proc_read(task, (char*)page); 717 718 if (length >= 0) 719 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length); 720 free_page(page); 721 out: 722 put_task_struct(task); 723 out_no_task: 724 return length; 725 } 726 727 static const struct file_operations proc_info_file_operations = { 728 .read = proc_info_read, 729 .llseek = generic_file_llseek, 730 }; 731 732 static int proc_single_show(struct seq_file *m, void *v) 733 { 734 struct inode *inode = m->private; 735 struct pid_namespace *ns; 736 struct pid *pid; 737 struct task_struct *task; 738 int ret; 739 740 ns = inode->i_sb->s_fs_info; 741 pid = proc_pid(inode); 742 task = get_pid_task(pid, PIDTYPE_PID); 743 if (!task) 744 return -ESRCH; 745 746 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 747 748 put_task_struct(task); 749 return ret; 750 } 751 752 static int proc_single_open(struct inode *inode, struct file *filp) 753 { 754 int ret; 755 ret = single_open(filp, proc_single_show, NULL); 756 if (!ret) { 757 struct seq_file *m = filp->private_data; 758 759 m->private = inode; 760 } 761 return ret; 762 } 763 764 static const struct file_operations proc_single_file_operations = { 765 .open = proc_single_open, 766 .read = seq_read, 767 .llseek = seq_lseek, 768 .release = single_release, 769 }; 770 771 static int mem_open(struct inode* inode, struct file* file) 772 { 773 file->private_data = (void*)((long)current->self_exec_id); 774 /* OK to pass negative loff_t, we can catch out-of-range */ 775 file->f_mode |= FMODE_UNSIGNED_OFFSET; 776 return 0; 777 } 778 779 static ssize_t mem_read(struct file * file, char __user * buf, 780 size_t count, loff_t *ppos) 781 { 782 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 783 char *page; 784 unsigned long src = *ppos; 785 int ret = -ESRCH; 786 struct mm_struct *mm; 787 788 if (!task) 789 goto out_no_task; 790 791 if (check_mem_permission(task)) 792 goto out; 793 794 ret = -ENOMEM; 795 page = (char *)__get_free_page(GFP_TEMPORARY); 796 if (!page) 797 goto out; 798 799 ret = 0; 800 801 mm = get_task_mm(task); 802 if (!mm) 803 goto out_free; 804 805 ret = -EIO; 806 807 if (file->private_data != (void*)((long)current->self_exec_id)) 808 goto out_put; 809 810 ret = 0; 811 812 while (count > 0) { 813 int this_len, retval; 814 815 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 816 retval = access_process_vm(task, src, page, this_len, 0); 817 if (!retval || check_mem_permission(task)) { 818 if (!ret) 819 ret = -EIO; 820 break; 821 } 822 823 if (copy_to_user(buf, page, retval)) { 824 ret = -EFAULT; 825 break; 826 } 827 828 ret += retval; 829 src += retval; 830 buf += retval; 831 count -= retval; 832 } 833 *ppos = src; 834 835 out_put: 836 mmput(mm); 837 out_free: 838 free_page((unsigned long) page); 839 out: 840 put_task_struct(task); 841 out_no_task: 842 return ret; 843 } 844 845 #define mem_write NULL 846 847 #ifndef mem_write 848 /* This is a security hazard */ 849 static ssize_t mem_write(struct file * file, const char __user *buf, 850 size_t count, loff_t *ppos) 851 { 852 int copied; 853 char *page; 854 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 855 unsigned long dst = *ppos; 856 857 copied = -ESRCH; 858 if (!task) 859 goto out_no_task; 860 861 if (check_mem_permission(task)) 862 goto out; 863 864 copied = -ENOMEM; 865 page = (char *)__get_free_page(GFP_TEMPORARY); 866 if (!page) 867 goto out; 868 869 copied = 0; 870 while (count > 0) { 871 int this_len, retval; 872 873 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 874 if (copy_from_user(page, buf, this_len)) { 875 copied = -EFAULT; 876 break; 877 } 878 retval = access_process_vm(task, dst, page, this_len, 1); 879 if (!retval) { 880 if (!copied) 881 copied = -EIO; 882 break; 883 } 884 copied += retval; 885 buf += retval; 886 dst += retval; 887 count -= retval; 888 } 889 *ppos = dst; 890 free_page((unsigned long) page); 891 out: 892 put_task_struct(task); 893 out_no_task: 894 return copied; 895 } 896 #endif 897 898 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 899 { 900 switch (orig) { 901 case 0: 902 file->f_pos = offset; 903 break; 904 case 1: 905 file->f_pos += offset; 906 break; 907 default: 908 return -EINVAL; 909 } 910 force_successful_syscall_return(); 911 return file->f_pos; 912 } 913 914 static const struct file_operations proc_mem_operations = { 915 .llseek = mem_lseek, 916 .read = mem_read, 917 .write = mem_write, 918 .open = mem_open, 919 }; 920 921 static ssize_t environ_read(struct file *file, char __user *buf, 922 size_t count, loff_t *ppos) 923 { 924 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 925 char *page; 926 unsigned long src = *ppos; 927 int ret = -ESRCH; 928 struct mm_struct *mm; 929 930 if (!task) 931 goto out_no_task; 932 933 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 934 goto out; 935 936 ret = -ENOMEM; 937 page = (char *)__get_free_page(GFP_TEMPORARY); 938 if (!page) 939 goto out; 940 941 ret = 0; 942 943 mm = get_task_mm(task); 944 if (!mm) 945 goto out_free; 946 947 while (count > 0) { 948 int this_len, retval, max_len; 949 950 this_len = mm->env_end - (mm->env_start + src); 951 952 if (this_len <= 0) 953 break; 954 955 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 956 this_len = (this_len > max_len) ? max_len : this_len; 957 958 retval = access_process_vm(task, (mm->env_start + src), 959 page, this_len, 0); 960 961 if (retval <= 0) { 962 ret = retval; 963 break; 964 } 965 966 if (copy_to_user(buf, page, retval)) { 967 ret = -EFAULT; 968 break; 969 } 970 971 ret += retval; 972 src += retval; 973 buf += retval; 974 count -= retval; 975 } 976 *ppos = src; 977 978 mmput(mm); 979 out_free: 980 free_page((unsigned long) page); 981 out: 982 put_task_struct(task); 983 out_no_task: 984 return ret; 985 } 986 987 static const struct file_operations proc_environ_operations = { 988 .read = environ_read, 989 .llseek = generic_file_llseek, 990 }; 991 992 static ssize_t oom_adjust_read(struct file *file, char __user *buf, 993 size_t count, loff_t *ppos) 994 { 995 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 996 char buffer[PROC_NUMBUF]; 997 size_t len; 998 int oom_adjust = OOM_DISABLE; 999 unsigned long flags; 1000 1001 if (!task) 1002 return -ESRCH; 1003 1004 if (lock_task_sighand(task, &flags)) { 1005 oom_adjust = task->signal->oom_adj; 1006 unlock_task_sighand(task, &flags); 1007 } 1008 1009 put_task_struct(task); 1010 1011 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); 1012 1013 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1014 } 1015 1016 static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 1017 size_t count, loff_t *ppos) 1018 { 1019 struct task_struct *task; 1020 char buffer[PROC_NUMBUF]; 1021 long oom_adjust; 1022 unsigned long flags; 1023 int err; 1024 1025 memset(buffer, 0, sizeof(buffer)); 1026 if (count > sizeof(buffer) - 1) 1027 count = sizeof(buffer) - 1; 1028 if (copy_from_user(buffer, buf, count)) { 1029 err = -EFAULT; 1030 goto out; 1031 } 1032 1033 err = strict_strtol(strstrip(buffer), 0, &oom_adjust); 1034 if (err) 1035 goto out; 1036 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && 1037 oom_adjust != OOM_DISABLE) { 1038 err = -EINVAL; 1039 goto out; 1040 } 1041 1042 task = get_proc_task(file->f_path.dentry->d_inode); 1043 if (!task) { 1044 err = -ESRCH; 1045 goto out; 1046 } 1047 1048 task_lock(task); 1049 if (!task->mm) { 1050 err = -EINVAL; 1051 goto err_task_lock; 1052 } 1053 1054 if (!lock_task_sighand(task, &flags)) { 1055 err = -ESRCH; 1056 goto err_task_lock; 1057 } 1058 1059 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) { 1060 err = -EACCES; 1061 goto err_sighand; 1062 } 1063 1064 if (oom_adjust != task->signal->oom_adj) { 1065 if (oom_adjust == OOM_DISABLE) 1066 atomic_inc(&task->mm->oom_disable_count); 1067 if (task->signal->oom_adj == OOM_DISABLE) 1068 atomic_dec(&task->mm->oom_disable_count); 1069 } 1070 1071 /* 1072 * Warn that /proc/pid/oom_adj is deprecated, see 1073 * Documentation/feature-removal-schedule.txt. 1074 */ 1075 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, " 1076 "please use /proc/%d/oom_score_adj instead.\n", 1077 current->comm, task_pid_nr(current), 1078 task_pid_nr(task), task_pid_nr(task)); 1079 task->signal->oom_adj = oom_adjust; 1080 /* 1081 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 1082 * value is always attainable. 1083 */ 1084 if (task->signal->oom_adj == OOM_ADJUST_MAX) 1085 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX; 1086 else 1087 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) / 1088 -OOM_DISABLE; 1089 err_sighand: 1090 unlock_task_sighand(task, &flags); 1091 err_task_lock: 1092 task_unlock(task); 1093 put_task_struct(task); 1094 out: 1095 return err < 0 ? err : count; 1096 } 1097 1098 static const struct file_operations proc_oom_adjust_operations = { 1099 .read = oom_adjust_read, 1100 .write = oom_adjust_write, 1101 .llseek = generic_file_llseek, 1102 }; 1103 1104 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 1105 size_t count, loff_t *ppos) 1106 { 1107 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 1108 char buffer[PROC_NUMBUF]; 1109 int oom_score_adj = OOM_SCORE_ADJ_MIN; 1110 unsigned long flags; 1111 size_t len; 1112 1113 if (!task) 1114 return -ESRCH; 1115 if (lock_task_sighand(task, &flags)) { 1116 oom_score_adj = task->signal->oom_score_adj; 1117 unlock_task_sighand(task, &flags); 1118 } 1119 put_task_struct(task); 1120 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj); 1121 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1122 } 1123 1124 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1125 size_t count, loff_t *ppos) 1126 { 1127 struct task_struct *task; 1128 char buffer[PROC_NUMBUF]; 1129 unsigned long flags; 1130 long oom_score_adj; 1131 int err; 1132 1133 memset(buffer, 0, sizeof(buffer)); 1134 if (count > sizeof(buffer) - 1) 1135 count = sizeof(buffer) - 1; 1136 if (copy_from_user(buffer, buf, count)) { 1137 err = -EFAULT; 1138 goto out; 1139 } 1140 1141 err = strict_strtol(strstrip(buffer), 0, &oom_score_adj); 1142 if (err) 1143 goto out; 1144 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1145 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1146 err = -EINVAL; 1147 goto out; 1148 } 1149 1150 task = get_proc_task(file->f_path.dentry->d_inode); 1151 if (!task) { 1152 err = -ESRCH; 1153 goto out; 1154 } 1155 1156 task_lock(task); 1157 if (!task->mm) { 1158 err = -EINVAL; 1159 goto err_task_lock; 1160 } 1161 1162 if (!lock_task_sighand(task, &flags)) { 1163 err = -ESRCH; 1164 goto err_task_lock; 1165 } 1166 1167 if (oom_score_adj < task->signal->oom_score_adj && 1168 !capable(CAP_SYS_RESOURCE)) { 1169 err = -EACCES; 1170 goto err_sighand; 1171 } 1172 1173 if (oom_score_adj != task->signal->oom_score_adj) { 1174 if (oom_score_adj == OOM_SCORE_ADJ_MIN) 1175 atomic_inc(&task->mm->oom_disable_count); 1176 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) 1177 atomic_dec(&task->mm->oom_disable_count); 1178 } 1179 task->signal->oom_score_adj = oom_score_adj; 1180 /* 1181 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is 1182 * always attainable. 1183 */ 1184 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) 1185 task->signal->oom_adj = OOM_DISABLE; 1186 else 1187 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) / 1188 OOM_SCORE_ADJ_MAX; 1189 err_sighand: 1190 unlock_task_sighand(task, &flags); 1191 err_task_lock: 1192 task_unlock(task); 1193 put_task_struct(task); 1194 out: 1195 return err < 0 ? err : count; 1196 } 1197 1198 static const struct file_operations proc_oom_score_adj_operations = { 1199 .read = oom_score_adj_read, 1200 .write = oom_score_adj_write, 1201 .llseek = default_llseek, 1202 }; 1203 1204 #ifdef CONFIG_AUDITSYSCALL 1205 #define TMPBUFLEN 21 1206 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1207 size_t count, loff_t *ppos) 1208 { 1209 struct inode * inode = file->f_path.dentry->d_inode; 1210 struct task_struct *task = get_proc_task(inode); 1211 ssize_t length; 1212 char tmpbuf[TMPBUFLEN]; 1213 1214 if (!task) 1215 return -ESRCH; 1216 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1217 audit_get_loginuid(task)); 1218 put_task_struct(task); 1219 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1220 } 1221 1222 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1223 size_t count, loff_t *ppos) 1224 { 1225 struct inode * inode = file->f_path.dentry->d_inode; 1226 char *page, *tmp; 1227 ssize_t length; 1228 uid_t loginuid; 1229 1230 if (!capable(CAP_AUDIT_CONTROL)) 1231 return -EPERM; 1232 1233 rcu_read_lock(); 1234 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1235 rcu_read_unlock(); 1236 return -EPERM; 1237 } 1238 rcu_read_unlock(); 1239 1240 if (count >= PAGE_SIZE) 1241 count = PAGE_SIZE - 1; 1242 1243 if (*ppos != 0) { 1244 /* No partial writes. */ 1245 return -EINVAL; 1246 } 1247 page = (char*)__get_free_page(GFP_TEMPORARY); 1248 if (!page) 1249 return -ENOMEM; 1250 length = -EFAULT; 1251 if (copy_from_user(page, buf, count)) 1252 goto out_free_page; 1253 1254 page[count] = '\0'; 1255 loginuid = simple_strtoul(page, &tmp, 10); 1256 if (tmp == page) { 1257 length = -EINVAL; 1258 goto out_free_page; 1259 1260 } 1261 length = audit_set_loginuid(current, loginuid); 1262 if (likely(length == 0)) 1263 length = count; 1264 1265 out_free_page: 1266 free_page((unsigned long) page); 1267 return length; 1268 } 1269 1270 static const struct file_operations proc_loginuid_operations = { 1271 .read = proc_loginuid_read, 1272 .write = proc_loginuid_write, 1273 .llseek = generic_file_llseek, 1274 }; 1275 1276 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1277 size_t count, loff_t *ppos) 1278 { 1279 struct inode * inode = file->f_path.dentry->d_inode; 1280 struct task_struct *task = get_proc_task(inode); 1281 ssize_t length; 1282 char tmpbuf[TMPBUFLEN]; 1283 1284 if (!task) 1285 return -ESRCH; 1286 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1287 audit_get_sessionid(task)); 1288 put_task_struct(task); 1289 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1290 } 1291 1292 static const struct file_operations proc_sessionid_operations = { 1293 .read = proc_sessionid_read, 1294 .llseek = generic_file_llseek, 1295 }; 1296 #endif 1297 1298 #ifdef CONFIG_FAULT_INJECTION 1299 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1300 size_t count, loff_t *ppos) 1301 { 1302 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1303 char buffer[PROC_NUMBUF]; 1304 size_t len; 1305 int make_it_fail; 1306 1307 if (!task) 1308 return -ESRCH; 1309 make_it_fail = task->make_it_fail; 1310 put_task_struct(task); 1311 1312 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1313 1314 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1315 } 1316 1317 static ssize_t proc_fault_inject_write(struct file * file, 1318 const char __user * buf, size_t count, loff_t *ppos) 1319 { 1320 struct task_struct *task; 1321 char buffer[PROC_NUMBUF], *end; 1322 int make_it_fail; 1323 1324 if (!capable(CAP_SYS_RESOURCE)) 1325 return -EPERM; 1326 memset(buffer, 0, sizeof(buffer)); 1327 if (count > sizeof(buffer) - 1) 1328 count = sizeof(buffer) - 1; 1329 if (copy_from_user(buffer, buf, count)) 1330 return -EFAULT; 1331 make_it_fail = simple_strtol(strstrip(buffer), &end, 0); 1332 if (*end) 1333 return -EINVAL; 1334 task = get_proc_task(file->f_dentry->d_inode); 1335 if (!task) 1336 return -ESRCH; 1337 task->make_it_fail = make_it_fail; 1338 put_task_struct(task); 1339 1340 return count; 1341 } 1342 1343 static const struct file_operations proc_fault_inject_operations = { 1344 .read = proc_fault_inject_read, 1345 .write = proc_fault_inject_write, 1346 .llseek = generic_file_llseek, 1347 }; 1348 #endif 1349 1350 1351 #ifdef CONFIG_SCHED_DEBUG 1352 /* 1353 * Print out various scheduling related per-task fields: 1354 */ 1355 static int sched_show(struct seq_file *m, void *v) 1356 { 1357 struct inode *inode = m->private; 1358 struct task_struct *p; 1359 1360 p = get_proc_task(inode); 1361 if (!p) 1362 return -ESRCH; 1363 proc_sched_show_task(p, m); 1364 1365 put_task_struct(p); 1366 1367 return 0; 1368 } 1369 1370 static ssize_t 1371 sched_write(struct file *file, const char __user *buf, 1372 size_t count, loff_t *offset) 1373 { 1374 struct inode *inode = file->f_path.dentry->d_inode; 1375 struct task_struct *p; 1376 1377 p = get_proc_task(inode); 1378 if (!p) 1379 return -ESRCH; 1380 proc_sched_set_task(p); 1381 1382 put_task_struct(p); 1383 1384 return count; 1385 } 1386 1387 static int sched_open(struct inode *inode, struct file *filp) 1388 { 1389 int ret; 1390 1391 ret = single_open(filp, sched_show, NULL); 1392 if (!ret) { 1393 struct seq_file *m = filp->private_data; 1394 1395 m->private = inode; 1396 } 1397 return ret; 1398 } 1399 1400 static const struct file_operations proc_pid_sched_operations = { 1401 .open = sched_open, 1402 .read = seq_read, 1403 .write = sched_write, 1404 .llseek = seq_lseek, 1405 .release = single_release, 1406 }; 1407 1408 #endif 1409 1410 static ssize_t comm_write(struct file *file, const char __user *buf, 1411 size_t count, loff_t *offset) 1412 { 1413 struct inode *inode = file->f_path.dentry->d_inode; 1414 struct task_struct *p; 1415 char buffer[TASK_COMM_LEN]; 1416 1417 memset(buffer, 0, sizeof(buffer)); 1418 if (count > sizeof(buffer) - 1) 1419 count = sizeof(buffer) - 1; 1420 if (copy_from_user(buffer, buf, count)) 1421 return -EFAULT; 1422 1423 p = get_proc_task(inode); 1424 if (!p) 1425 return -ESRCH; 1426 1427 if (same_thread_group(current, p)) 1428 set_task_comm(p, buffer); 1429 else 1430 count = -EINVAL; 1431 1432 put_task_struct(p); 1433 1434 return count; 1435 } 1436 1437 static int comm_show(struct seq_file *m, void *v) 1438 { 1439 struct inode *inode = m->private; 1440 struct task_struct *p; 1441 1442 p = get_proc_task(inode); 1443 if (!p) 1444 return -ESRCH; 1445 1446 task_lock(p); 1447 seq_printf(m, "%s\n", p->comm); 1448 task_unlock(p); 1449 1450 put_task_struct(p); 1451 1452 return 0; 1453 } 1454 1455 static int comm_open(struct inode *inode, struct file *filp) 1456 { 1457 int ret; 1458 1459 ret = single_open(filp, comm_show, NULL); 1460 if (!ret) { 1461 struct seq_file *m = filp->private_data; 1462 1463 m->private = inode; 1464 } 1465 return ret; 1466 } 1467 1468 static const struct file_operations proc_pid_set_comm_operations = { 1469 .open = comm_open, 1470 .read = seq_read, 1471 .write = comm_write, 1472 .llseek = seq_lseek, 1473 .release = single_release, 1474 }; 1475 1476 /* 1477 * We added or removed a vma mapping the executable. The vmas are only mapped 1478 * during exec and are not mapped with the mmap system call. 1479 * Callers must hold down_write() on the mm's mmap_sem for these 1480 */ 1481 void added_exe_file_vma(struct mm_struct *mm) 1482 { 1483 mm->num_exe_file_vmas++; 1484 } 1485 1486 void removed_exe_file_vma(struct mm_struct *mm) 1487 { 1488 mm->num_exe_file_vmas--; 1489 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){ 1490 fput(mm->exe_file); 1491 mm->exe_file = NULL; 1492 } 1493 1494 } 1495 1496 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) 1497 { 1498 if (new_exe_file) 1499 get_file(new_exe_file); 1500 if (mm->exe_file) 1501 fput(mm->exe_file); 1502 mm->exe_file = new_exe_file; 1503 mm->num_exe_file_vmas = 0; 1504 } 1505 1506 struct file *get_mm_exe_file(struct mm_struct *mm) 1507 { 1508 struct file *exe_file; 1509 1510 /* We need mmap_sem to protect against races with removal of 1511 * VM_EXECUTABLE vmas */ 1512 down_read(&mm->mmap_sem); 1513 exe_file = mm->exe_file; 1514 if (exe_file) 1515 get_file(exe_file); 1516 up_read(&mm->mmap_sem); 1517 return exe_file; 1518 } 1519 1520 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm) 1521 { 1522 /* It's safe to write the exe_file pointer without exe_file_lock because 1523 * this is called during fork when the task is not yet in /proc */ 1524 newmm->exe_file = get_mm_exe_file(oldmm); 1525 } 1526 1527 static int proc_exe_link(struct inode *inode, struct path *exe_path) 1528 { 1529 struct task_struct *task; 1530 struct mm_struct *mm; 1531 struct file *exe_file; 1532 1533 task = get_proc_task(inode); 1534 if (!task) 1535 return -ENOENT; 1536 mm = get_task_mm(task); 1537 put_task_struct(task); 1538 if (!mm) 1539 return -ENOENT; 1540 exe_file = get_mm_exe_file(mm); 1541 mmput(mm); 1542 if (exe_file) { 1543 *exe_path = exe_file->f_path; 1544 path_get(&exe_file->f_path); 1545 fput(exe_file); 1546 return 0; 1547 } else 1548 return -ENOENT; 1549 } 1550 1551 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1552 { 1553 struct inode *inode = dentry->d_inode; 1554 int error = -EACCES; 1555 1556 /* We don't need a base pointer in the /proc filesystem */ 1557 path_put(&nd->path); 1558 1559 /* Are we allowed to snoop on the tasks file descriptors? */ 1560 if (!proc_fd_access_allowed(inode)) 1561 goto out; 1562 1563 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path); 1564 out: 1565 return ERR_PTR(error); 1566 } 1567 1568 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1569 { 1570 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1571 char *pathname; 1572 int len; 1573 1574 if (!tmp) 1575 return -ENOMEM; 1576 1577 pathname = d_path_with_unreachable(path, tmp, PAGE_SIZE); 1578 len = PTR_ERR(pathname); 1579 if (IS_ERR(pathname)) 1580 goto out; 1581 len = tmp + PAGE_SIZE - 1 - pathname; 1582 1583 if (len > buflen) 1584 len = buflen; 1585 if (copy_to_user(buffer, pathname, len)) 1586 len = -EFAULT; 1587 out: 1588 free_page((unsigned long)tmp); 1589 return len; 1590 } 1591 1592 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1593 { 1594 int error = -EACCES; 1595 struct inode *inode = dentry->d_inode; 1596 struct path path; 1597 1598 /* Are we allowed to snoop on the tasks file descriptors? */ 1599 if (!proc_fd_access_allowed(inode)) 1600 goto out; 1601 1602 error = PROC_I(inode)->op.proc_get_link(inode, &path); 1603 if (error) 1604 goto out; 1605 1606 error = do_proc_readlink(&path, buffer, buflen); 1607 path_put(&path); 1608 out: 1609 return error; 1610 } 1611 1612 static const struct inode_operations proc_pid_link_inode_operations = { 1613 .readlink = proc_pid_readlink, 1614 .follow_link = proc_pid_follow_link, 1615 .setattr = proc_setattr, 1616 }; 1617 1618 1619 /* building an inode */ 1620 1621 static int task_dumpable(struct task_struct *task) 1622 { 1623 int dumpable = 0; 1624 struct mm_struct *mm; 1625 1626 task_lock(task); 1627 mm = task->mm; 1628 if (mm) 1629 dumpable = get_dumpable(mm); 1630 task_unlock(task); 1631 if(dumpable == 1) 1632 return 1; 1633 return 0; 1634 } 1635 1636 1637 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1638 { 1639 struct inode * inode; 1640 struct proc_inode *ei; 1641 const struct cred *cred; 1642 1643 /* We need a new inode */ 1644 1645 inode = new_inode(sb); 1646 if (!inode) 1647 goto out; 1648 1649 /* Common stuff */ 1650 ei = PROC_I(inode); 1651 inode->i_ino = get_next_ino(); 1652 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1653 inode->i_op = &proc_def_inode_operations; 1654 1655 /* 1656 * grab the reference to task. 1657 */ 1658 ei->pid = get_task_pid(task, PIDTYPE_PID); 1659 if (!ei->pid) 1660 goto out_unlock; 1661 1662 if (task_dumpable(task)) { 1663 rcu_read_lock(); 1664 cred = __task_cred(task); 1665 inode->i_uid = cred->euid; 1666 inode->i_gid = cred->egid; 1667 rcu_read_unlock(); 1668 } 1669 security_task_to_inode(task, inode); 1670 1671 out: 1672 return inode; 1673 1674 out_unlock: 1675 iput(inode); 1676 return NULL; 1677 } 1678 1679 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1680 { 1681 struct inode *inode = dentry->d_inode; 1682 struct task_struct *task; 1683 const struct cred *cred; 1684 1685 generic_fillattr(inode, stat); 1686 1687 rcu_read_lock(); 1688 stat->uid = 0; 1689 stat->gid = 0; 1690 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1691 if (task) { 1692 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1693 task_dumpable(task)) { 1694 cred = __task_cred(task); 1695 stat->uid = cred->euid; 1696 stat->gid = cred->egid; 1697 } 1698 } 1699 rcu_read_unlock(); 1700 return 0; 1701 } 1702 1703 /* dentry stuff */ 1704 1705 /* 1706 * Exceptional case: normally we are not allowed to unhash a busy 1707 * directory. In this case, however, we can do it - no aliasing problems 1708 * due to the way we treat inodes. 1709 * 1710 * Rewrite the inode's ownerships here because the owning task may have 1711 * performed a setuid(), etc. 1712 * 1713 * Before the /proc/pid/status file was created the only way to read 1714 * the effective uid of a /process was to stat /proc/pid. Reading 1715 * /proc/pid/status is slow enough that procps and other packages 1716 * kept stating /proc/pid. To keep the rules in /proc simple I have 1717 * made this apply to all per process world readable and executable 1718 * directories. 1719 */ 1720 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1721 { 1722 struct inode *inode = dentry->d_inode; 1723 struct task_struct *task = get_proc_task(inode); 1724 const struct cred *cred; 1725 1726 if (task) { 1727 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1728 task_dumpable(task)) { 1729 rcu_read_lock(); 1730 cred = __task_cred(task); 1731 inode->i_uid = cred->euid; 1732 inode->i_gid = cred->egid; 1733 rcu_read_unlock(); 1734 } else { 1735 inode->i_uid = 0; 1736 inode->i_gid = 0; 1737 } 1738 inode->i_mode &= ~(S_ISUID | S_ISGID); 1739 security_task_to_inode(task, inode); 1740 put_task_struct(task); 1741 return 1; 1742 } 1743 d_drop(dentry); 1744 return 0; 1745 } 1746 1747 static int pid_delete_dentry(struct dentry * dentry) 1748 { 1749 /* Is the task we represent dead? 1750 * If so, then don't put the dentry on the lru list, 1751 * kill it immediately. 1752 */ 1753 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1754 } 1755 1756 static const struct dentry_operations pid_dentry_operations = 1757 { 1758 .d_revalidate = pid_revalidate, 1759 .d_delete = pid_delete_dentry, 1760 }; 1761 1762 /* Lookups */ 1763 1764 typedef struct dentry *instantiate_t(struct inode *, struct dentry *, 1765 struct task_struct *, const void *); 1766 1767 /* 1768 * Fill a directory entry. 1769 * 1770 * If possible create the dcache entry and derive our inode number and 1771 * file type from dcache entry. 1772 * 1773 * Since all of the proc inode numbers are dynamically generated, the inode 1774 * numbers do not exist until the inode is cache. This means creating the 1775 * the dcache entry in readdir is necessary to keep the inode numbers 1776 * reported by readdir in sync with the inode numbers reported 1777 * by stat. 1778 */ 1779 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1780 char *name, int len, 1781 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1782 { 1783 struct dentry *child, *dir = filp->f_path.dentry; 1784 struct inode *inode; 1785 struct qstr qname; 1786 ino_t ino = 0; 1787 unsigned type = DT_UNKNOWN; 1788 1789 qname.name = name; 1790 qname.len = len; 1791 qname.hash = full_name_hash(name, len); 1792 1793 child = d_lookup(dir, &qname); 1794 if (!child) { 1795 struct dentry *new; 1796 new = d_alloc(dir, &qname); 1797 if (new) { 1798 child = instantiate(dir->d_inode, new, task, ptr); 1799 if (child) 1800 dput(new); 1801 else 1802 child = new; 1803 } 1804 } 1805 if (!child || IS_ERR(child) || !child->d_inode) 1806 goto end_instantiate; 1807 inode = child->d_inode; 1808 if (inode) { 1809 ino = inode->i_ino; 1810 type = inode->i_mode >> 12; 1811 } 1812 dput(child); 1813 end_instantiate: 1814 if (!ino) 1815 ino = find_inode_number(dir, &qname); 1816 if (!ino) 1817 ino = 1; 1818 return filldir(dirent, name, len, filp->f_pos, ino, type); 1819 } 1820 1821 static unsigned name_to_int(struct dentry *dentry) 1822 { 1823 const char *name = dentry->d_name.name; 1824 int len = dentry->d_name.len; 1825 unsigned n = 0; 1826 1827 if (len > 1 && *name == '0') 1828 goto out; 1829 while (len-- > 0) { 1830 unsigned c = *name++ - '0'; 1831 if (c > 9) 1832 goto out; 1833 if (n >= (~0U-9)/10) 1834 goto out; 1835 n *= 10; 1836 n += c; 1837 } 1838 return n; 1839 out: 1840 return ~0U; 1841 } 1842 1843 #define PROC_FDINFO_MAX 64 1844 1845 static int proc_fd_info(struct inode *inode, struct path *path, char *info) 1846 { 1847 struct task_struct *task = get_proc_task(inode); 1848 struct files_struct *files = NULL; 1849 struct file *file; 1850 int fd = proc_fd(inode); 1851 1852 if (task) { 1853 files = get_files_struct(task); 1854 put_task_struct(task); 1855 } 1856 if (files) { 1857 /* 1858 * We are not taking a ref to the file structure, so we must 1859 * hold ->file_lock. 1860 */ 1861 spin_lock(&files->file_lock); 1862 file = fcheck_files(files, fd); 1863 if (file) { 1864 if (path) { 1865 *path = file->f_path; 1866 path_get(&file->f_path); 1867 } 1868 if (info) 1869 snprintf(info, PROC_FDINFO_MAX, 1870 "pos:\t%lli\n" 1871 "flags:\t0%o\n", 1872 (long long) file->f_pos, 1873 file->f_flags); 1874 spin_unlock(&files->file_lock); 1875 put_files_struct(files); 1876 return 0; 1877 } 1878 spin_unlock(&files->file_lock); 1879 put_files_struct(files); 1880 } 1881 return -ENOENT; 1882 } 1883 1884 static int proc_fd_link(struct inode *inode, struct path *path) 1885 { 1886 return proc_fd_info(inode, path, NULL); 1887 } 1888 1889 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1890 { 1891 struct inode *inode = dentry->d_inode; 1892 struct task_struct *task = get_proc_task(inode); 1893 int fd = proc_fd(inode); 1894 struct files_struct *files; 1895 const struct cred *cred; 1896 1897 if (task) { 1898 files = get_files_struct(task); 1899 if (files) { 1900 rcu_read_lock(); 1901 if (fcheck_files(files, fd)) { 1902 rcu_read_unlock(); 1903 put_files_struct(files); 1904 if (task_dumpable(task)) { 1905 rcu_read_lock(); 1906 cred = __task_cred(task); 1907 inode->i_uid = cred->euid; 1908 inode->i_gid = cred->egid; 1909 rcu_read_unlock(); 1910 } else { 1911 inode->i_uid = 0; 1912 inode->i_gid = 0; 1913 } 1914 inode->i_mode &= ~(S_ISUID | S_ISGID); 1915 security_task_to_inode(task, inode); 1916 put_task_struct(task); 1917 return 1; 1918 } 1919 rcu_read_unlock(); 1920 put_files_struct(files); 1921 } 1922 put_task_struct(task); 1923 } 1924 d_drop(dentry); 1925 return 0; 1926 } 1927 1928 static const struct dentry_operations tid_fd_dentry_operations = 1929 { 1930 .d_revalidate = tid_fd_revalidate, 1931 .d_delete = pid_delete_dentry, 1932 }; 1933 1934 static struct dentry *proc_fd_instantiate(struct inode *dir, 1935 struct dentry *dentry, struct task_struct *task, const void *ptr) 1936 { 1937 unsigned fd = *(const unsigned *)ptr; 1938 struct file *file; 1939 struct files_struct *files; 1940 struct inode *inode; 1941 struct proc_inode *ei; 1942 struct dentry *error = ERR_PTR(-ENOENT); 1943 1944 inode = proc_pid_make_inode(dir->i_sb, task); 1945 if (!inode) 1946 goto out; 1947 ei = PROC_I(inode); 1948 ei->fd = fd; 1949 files = get_files_struct(task); 1950 if (!files) 1951 goto out_iput; 1952 inode->i_mode = S_IFLNK; 1953 1954 /* 1955 * We are not taking a ref to the file structure, so we must 1956 * hold ->file_lock. 1957 */ 1958 spin_lock(&files->file_lock); 1959 file = fcheck_files(files, fd); 1960 if (!file) 1961 goto out_unlock; 1962 if (file->f_mode & FMODE_READ) 1963 inode->i_mode |= S_IRUSR | S_IXUSR; 1964 if (file->f_mode & FMODE_WRITE) 1965 inode->i_mode |= S_IWUSR | S_IXUSR; 1966 spin_unlock(&files->file_lock); 1967 put_files_struct(files); 1968 1969 inode->i_op = &proc_pid_link_inode_operations; 1970 inode->i_size = 64; 1971 ei->op.proc_get_link = proc_fd_link; 1972 dentry->d_op = &tid_fd_dentry_operations; 1973 d_add(dentry, inode); 1974 /* Close the race of the process dying before we return the dentry */ 1975 if (tid_fd_revalidate(dentry, NULL)) 1976 error = NULL; 1977 1978 out: 1979 return error; 1980 out_unlock: 1981 spin_unlock(&files->file_lock); 1982 put_files_struct(files); 1983 out_iput: 1984 iput(inode); 1985 goto out; 1986 } 1987 1988 static struct dentry *proc_lookupfd_common(struct inode *dir, 1989 struct dentry *dentry, 1990 instantiate_t instantiate) 1991 { 1992 struct task_struct *task = get_proc_task(dir); 1993 unsigned fd = name_to_int(dentry); 1994 struct dentry *result = ERR_PTR(-ENOENT); 1995 1996 if (!task) 1997 goto out_no_task; 1998 if (fd == ~0U) 1999 goto out; 2000 2001 result = instantiate(dir, dentry, task, &fd); 2002 out: 2003 put_task_struct(task); 2004 out_no_task: 2005 return result; 2006 } 2007 2008 static int proc_readfd_common(struct file * filp, void * dirent, 2009 filldir_t filldir, instantiate_t instantiate) 2010 { 2011 struct dentry *dentry = filp->f_path.dentry; 2012 struct inode *inode = dentry->d_inode; 2013 struct task_struct *p = get_proc_task(inode); 2014 unsigned int fd, ino; 2015 int retval; 2016 struct files_struct * files; 2017 2018 retval = -ENOENT; 2019 if (!p) 2020 goto out_no_task; 2021 retval = 0; 2022 2023 fd = filp->f_pos; 2024 switch (fd) { 2025 case 0: 2026 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 2027 goto out; 2028 filp->f_pos++; 2029 case 1: 2030 ino = parent_ino(dentry); 2031 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 2032 goto out; 2033 filp->f_pos++; 2034 default: 2035 files = get_files_struct(p); 2036 if (!files) 2037 goto out; 2038 rcu_read_lock(); 2039 for (fd = filp->f_pos-2; 2040 fd < files_fdtable(files)->max_fds; 2041 fd++, filp->f_pos++) { 2042 char name[PROC_NUMBUF]; 2043 int len; 2044 2045 if (!fcheck_files(files, fd)) 2046 continue; 2047 rcu_read_unlock(); 2048 2049 len = snprintf(name, sizeof(name), "%d", fd); 2050 if (proc_fill_cache(filp, dirent, filldir, 2051 name, len, instantiate, 2052 p, &fd) < 0) { 2053 rcu_read_lock(); 2054 break; 2055 } 2056 rcu_read_lock(); 2057 } 2058 rcu_read_unlock(); 2059 put_files_struct(files); 2060 } 2061 out: 2062 put_task_struct(p); 2063 out_no_task: 2064 return retval; 2065 } 2066 2067 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 2068 struct nameidata *nd) 2069 { 2070 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 2071 } 2072 2073 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 2074 { 2075 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 2076 } 2077 2078 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 2079 size_t len, loff_t *ppos) 2080 { 2081 char tmp[PROC_FDINFO_MAX]; 2082 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); 2083 if (!err) 2084 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 2085 return err; 2086 } 2087 2088 static const struct file_operations proc_fdinfo_file_operations = { 2089 .open = nonseekable_open, 2090 .read = proc_fdinfo_read, 2091 .llseek = no_llseek, 2092 }; 2093 2094 static const struct file_operations proc_fd_operations = { 2095 .read = generic_read_dir, 2096 .readdir = proc_readfd, 2097 .llseek = default_llseek, 2098 }; 2099 2100 /* 2101 * /proc/pid/fd needs a special permission handler so that a process can still 2102 * access /proc/self/fd after it has executed a setuid(). 2103 */ 2104 static int proc_fd_permission(struct inode *inode, int mask) 2105 { 2106 int rv; 2107 2108 rv = generic_permission(inode, mask, NULL); 2109 if (rv == 0) 2110 return 0; 2111 if (task_pid(current) == proc_pid(inode)) 2112 rv = 0; 2113 return rv; 2114 } 2115 2116 /* 2117 * proc directories can do almost nothing.. 2118 */ 2119 static const struct inode_operations proc_fd_inode_operations = { 2120 .lookup = proc_lookupfd, 2121 .permission = proc_fd_permission, 2122 .setattr = proc_setattr, 2123 }; 2124 2125 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 2126 struct dentry *dentry, struct task_struct *task, const void *ptr) 2127 { 2128 unsigned fd = *(unsigned *)ptr; 2129 struct inode *inode; 2130 struct proc_inode *ei; 2131 struct dentry *error = ERR_PTR(-ENOENT); 2132 2133 inode = proc_pid_make_inode(dir->i_sb, task); 2134 if (!inode) 2135 goto out; 2136 ei = PROC_I(inode); 2137 ei->fd = fd; 2138 inode->i_mode = S_IFREG | S_IRUSR; 2139 inode->i_fop = &proc_fdinfo_file_operations; 2140 dentry->d_op = &tid_fd_dentry_operations; 2141 d_add(dentry, inode); 2142 /* Close the race of the process dying before we return the dentry */ 2143 if (tid_fd_revalidate(dentry, NULL)) 2144 error = NULL; 2145 2146 out: 2147 return error; 2148 } 2149 2150 static struct dentry *proc_lookupfdinfo(struct inode *dir, 2151 struct dentry *dentry, 2152 struct nameidata *nd) 2153 { 2154 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 2155 } 2156 2157 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 2158 { 2159 return proc_readfd_common(filp, dirent, filldir, 2160 proc_fdinfo_instantiate); 2161 } 2162 2163 static const struct file_operations proc_fdinfo_operations = { 2164 .read = generic_read_dir, 2165 .readdir = proc_readfdinfo, 2166 .llseek = default_llseek, 2167 }; 2168 2169 /* 2170 * proc directories can do almost nothing.. 2171 */ 2172 static const struct inode_operations proc_fdinfo_inode_operations = { 2173 .lookup = proc_lookupfdinfo, 2174 .setattr = proc_setattr, 2175 }; 2176 2177 2178 static struct dentry *proc_pident_instantiate(struct inode *dir, 2179 struct dentry *dentry, struct task_struct *task, const void *ptr) 2180 { 2181 const struct pid_entry *p = ptr; 2182 struct inode *inode; 2183 struct proc_inode *ei; 2184 struct dentry *error = ERR_PTR(-ENOENT); 2185 2186 inode = proc_pid_make_inode(dir->i_sb, task); 2187 if (!inode) 2188 goto out; 2189 2190 ei = PROC_I(inode); 2191 inode->i_mode = p->mode; 2192 if (S_ISDIR(inode->i_mode)) 2193 inode->i_nlink = 2; /* Use getattr to fix if necessary */ 2194 if (p->iop) 2195 inode->i_op = p->iop; 2196 if (p->fop) 2197 inode->i_fop = p->fop; 2198 ei->op = p->op; 2199 dentry->d_op = &pid_dentry_operations; 2200 d_add(dentry, inode); 2201 /* Close the race of the process dying before we return the dentry */ 2202 if (pid_revalidate(dentry, NULL)) 2203 error = NULL; 2204 out: 2205 return error; 2206 } 2207 2208 static struct dentry *proc_pident_lookup(struct inode *dir, 2209 struct dentry *dentry, 2210 const struct pid_entry *ents, 2211 unsigned int nents) 2212 { 2213 struct dentry *error; 2214 struct task_struct *task = get_proc_task(dir); 2215 const struct pid_entry *p, *last; 2216 2217 error = ERR_PTR(-ENOENT); 2218 2219 if (!task) 2220 goto out_no_task; 2221 2222 /* 2223 * Yes, it does not scale. And it should not. Don't add 2224 * new entries into /proc/<tgid>/ without very good reasons. 2225 */ 2226 last = &ents[nents - 1]; 2227 for (p = ents; p <= last; p++) { 2228 if (p->len != dentry->d_name.len) 2229 continue; 2230 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2231 break; 2232 } 2233 if (p > last) 2234 goto out; 2235 2236 error = proc_pident_instantiate(dir, dentry, task, p); 2237 out: 2238 put_task_struct(task); 2239 out_no_task: 2240 return error; 2241 } 2242 2243 static int proc_pident_fill_cache(struct file *filp, void *dirent, 2244 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2245 { 2246 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2247 proc_pident_instantiate, task, p); 2248 } 2249 2250 static int proc_pident_readdir(struct file *filp, 2251 void *dirent, filldir_t filldir, 2252 const struct pid_entry *ents, unsigned int nents) 2253 { 2254 int i; 2255 struct dentry *dentry = filp->f_path.dentry; 2256 struct inode *inode = dentry->d_inode; 2257 struct task_struct *task = get_proc_task(inode); 2258 const struct pid_entry *p, *last; 2259 ino_t ino; 2260 int ret; 2261 2262 ret = -ENOENT; 2263 if (!task) 2264 goto out_no_task; 2265 2266 ret = 0; 2267 i = filp->f_pos; 2268 switch (i) { 2269 case 0: 2270 ino = inode->i_ino; 2271 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 2272 goto out; 2273 i++; 2274 filp->f_pos++; 2275 /* fall through */ 2276 case 1: 2277 ino = parent_ino(dentry); 2278 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 2279 goto out; 2280 i++; 2281 filp->f_pos++; 2282 /* fall through */ 2283 default: 2284 i -= 2; 2285 if (i >= nents) { 2286 ret = 1; 2287 goto out; 2288 } 2289 p = ents + i; 2290 last = &ents[nents - 1]; 2291 while (p <= last) { 2292 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2293 goto out; 2294 filp->f_pos++; 2295 p++; 2296 } 2297 } 2298 2299 ret = 1; 2300 out: 2301 put_task_struct(task); 2302 out_no_task: 2303 return ret; 2304 } 2305 2306 #ifdef CONFIG_SECURITY 2307 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2308 size_t count, loff_t *ppos) 2309 { 2310 struct inode * inode = file->f_path.dentry->d_inode; 2311 char *p = NULL; 2312 ssize_t length; 2313 struct task_struct *task = get_proc_task(inode); 2314 2315 if (!task) 2316 return -ESRCH; 2317 2318 length = security_getprocattr(task, 2319 (char*)file->f_path.dentry->d_name.name, 2320 &p); 2321 put_task_struct(task); 2322 if (length > 0) 2323 length = simple_read_from_buffer(buf, count, ppos, p, length); 2324 kfree(p); 2325 return length; 2326 } 2327 2328 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2329 size_t count, loff_t *ppos) 2330 { 2331 struct inode * inode = file->f_path.dentry->d_inode; 2332 char *page; 2333 ssize_t length; 2334 struct task_struct *task = get_proc_task(inode); 2335 2336 length = -ESRCH; 2337 if (!task) 2338 goto out_no_task; 2339 if (count > PAGE_SIZE) 2340 count = PAGE_SIZE; 2341 2342 /* No partial writes. */ 2343 length = -EINVAL; 2344 if (*ppos != 0) 2345 goto out; 2346 2347 length = -ENOMEM; 2348 page = (char*)__get_free_page(GFP_TEMPORARY); 2349 if (!page) 2350 goto out; 2351 2352 length = -EFAULT; 2353 if (copy_from_user(page, buf, count)) 2354 goto out_free; 2355 2356 /* Guard against adverse ptrace interaction */ 2357 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex); 2358 if (length < 0) 2359 goto out_free; 2360 2361 length = security_setprocattr(task, 2362 (char*)file->f_path.dentry->d_name.name, 2363 (void*)page, count); 2364 mutex_unlock(&task->signal->cred_guard_mutex); 2365 out_free: 2366 free_page((unsigned long) page); 2367 out: 2368 put_task_struct(task); 2369 out_no_task: 2370 return length; 2371 } 2372 2373 static const struct file_operations proc_pid_attr_operations = { 2374 .read = proc_pid_attr_read, 2375 .write = proc_pid_attr_write, 2376 .llseek = generic_file_llseek, 2377 }; 2378 2379 static const struct pid_entry attr_dir_stuff[] = { 2380 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2381 REG("prev", S_IRUGO, proc_pid_attr_operations), 2382 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2383 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2384 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2385 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2386 }; 2387 2388 static int proc_attr_dir_readdir(struct file * filp, 2389 void * dirent, filldir_t filldir) 2390 { 2391 return proc_pident_readdir(filp,dirent,filldir, 2392 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2393 } 2394 2395 static const struct file_operations proc_attr_dir_operations = { 2396 .read = generic_read_dir, 2397 .readdir = proc_attr_dir_readdir, 2398 .llseek = default_llseek, 2399 }; 2400 2401 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2402 struct dentry *dentry, struct nameidata *nd) 2403 { 2404 return proc_pident_lookup(dir, dentry, 2405 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2406 } 2407 2408 static const struct inode_operations proc_attr_dir_inode_operations = { 2409 .lookup = proc_attr_dir_lookup, 2410 .getattr = pid_getattr, 2411 .setattr = proc_setattr, 2412 }; 2413 2414 #endif 2415 2416 #ifdef CONFIG_ELF_CORE 2417 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2418 size_t count, loff_t *ppos) 2419 { 2420 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2421 struct mm_struct *mm; 2422 char buffer[PROC_NUMBUF]; 2423 size_t len; 2424 int ret; 2425 2426 if (!task) 2427 return -ESRCH; 2428 2429 ret = 0; 2430 mm = get_task_mm(task); 2431 if (mm) { 2432 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2433 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2434 MMF_DUMP_FILTER_SHIFT)); 2435 mmput(mm); 2436 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2437 } 2438 2439 put_task_struct(task); 2440 2441 return ret; 2442 } 2443 2444 static ssize_t proc_coredump_filter_write(struct file *file, 2445 const char __user *buf, 2446 size_t count, 2447 loff_t *ppos) 2448 { 2449 struct task_struct *task; 2450 struct mm_struct *mm; 2451 char buffer[PROC_NUMBUF], *end; 2452 unsigned int val; 2453 int ret; 2454 int i; 2455 unsigned long mask; 2456 2457 ret = -EFAULT; 2458 memset(buffer, 0, sizeof(buffer)); 2459 if (count > sizeof(buffer) - 1) 2460 count = sizeof(buffer) - 1; 2461 if (copy_from_user(buffer, buf, count)) 2462 goto out_no_task; 2463 2464 ret = -EINVAL; 2465 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2466 if (*end == '\n') 2467 end++; 2468 if (end - buffer == 0) 2469 goto out_no_task; 2470 2471 ret = -ESRCH; 2472 task = get_proc_task(file->f_dentry->d_inode); 2473 if (!task) 2474 goto out_no_task; 2475 2476 ret = end - buffer; 2477 mm = get_task_mm(task); 2478 if (!mm) 2479 goto out_no_mm; 2480 2481 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2482 if (val & mask) 2483 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2484 else 2485 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2486 } 2487 2488 mmput(mm); 2489 out_no_mm: 2490 put_task_struct(task); 2491 out_no_task: 2492 return ret; 2493 } 2494 2495 static const struct file_operations proc_coredump_filter_operations = { 2496 .read = proc_coredump_filter_read, 2497 .write = proc_coredump_filter_write, 2498 .llseek = generic_file_llseek, 2499 }; 2500 #endif 2501 2502 /* 2503 * /proc/self: 2504 */ 2505 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2506 int buflen) 2507 { 2508 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2509 pid_t tgid = task_tgid_nr_ns(current, ns); 2510 char tmp[PROC_NUMBUF]; 2511 if (!tgid) 2512 return -ENOENT; 2513 sprintf(tmp, "%d", tgid); 2514 return vfs_readlink(dentry,buffer,buflen,tmp); 2515 } 2516 2517 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2518 { 2519 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2520 pid_t tgid = task_tgid_nr_ns(current, ns); 2521 char *name = ERR_PTR(-ENOENT); 2522 if (tgid) { 2523 name = __getname(); 2524 if (!name) 2525 name = ERR_PTR(-ENOMEM); 2526 else 2527 sprintf(name, "%d", tgid); 2528 } 2529 nd_set_link(nd, name); 2530 return NULL; 2531 } 2532 2533 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd, 2534 void *cookie) 2535 { 2536 char *s = nd_get_link(nd); 2537 if (!IS_ERR(s)) 2538 __putname(s); 2539 } 2540 2541 static const struct inode_operations proc_self_inode_operations = { 2542 .readlink = proc_self_readlink, 2543 .follow_link = proc_self_follow_link, 2544 .put_link = proc_self_put_link, 2545 }; 2546 2547 /* 2548 * proc base 2549 * 2550 * These are the directory entries in the root directory of /proc 2551 * that properly belong to the /proc filesystem, as they describe 2552 * describe something that is process related. 2553 */ 2554 static const struct pid_entry proc_base_stuff[] = { 2555 NOD("self", S_IFLNK|S_IRWXUGO, 2556 &proc_self_inode_operations, NULL, {}), 2557 }; 2558 2559 /* 2560 * Exceptional case: normally we are not allowed to unhash a busy 2561 * directory. In this case, however, we can do it - no aliasing problems 2562 * due to the way we treat inodes. 2563 */ 2564 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) 2565 { 2566 struct inode *inode = dentry->d_inode; 2567 struct task_struct *task = get_proc_task(inode); 2568 if (task) { 2569 put_task_struct(task); 2570 return 1; 2571 } 2572 d_drop(dentry); 2573 return 0; 2574 } 2575 2576 static const struct dentry_operations proc_base_dentry_operations = 2577 { 2578 .d_revalidate = proc_base_revalidate, 2579 .d_delete = pid_delete_dentry, 2580 }; 2581 2582 static struct dentry *proc_base_instantiate(struct inode *dir, 2583 struct dentry *dentry, struct task_struct *task, const void *ptr) 2584 { 2585 const struct pid_entry *p = ptr; 2586 struct inode *inode; 2587 struct proc_inode *ei; 2588 struct dentry *error; 2589 2590 /* Allocate the inode */ 2591 error = ERR_PTR(-ENOMEM); 2592 inode = new_inode(dir->i_sb); 2593 if (!inode) 2594 goto out; 2595 2596 /* Initialize the inode */ 2597 ei = PROC_I(inode); 2598 inode->i_ino = get_next_ino(); 2599 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2600 2601 /* 2602 * grab the reference to the task. 2603 */ 2604 ei->pid = get_task_pid(task, PIDTYPE_PID); 2605 if (!ei->pid) 2606 goto out_iput; 2607 2608 inode->i_mode = p->mode; 2609 if (S_ISDIR(inode->i_mode)) 2610 inode->i_nlink = 2; 2611 if (S_ISLNK(inode->i_mode)) 2612 inode->i_size = 64; 2613 if (p->iop) 2614 inode->i_op = p->iop; 2615 if (p->fop) 2616 inode->i_fop = p->fop; 2617 ei->op = p->op; 2618 dentry->d_op = &proc_base_dentry_operations; 2619 d_add(dentry, inode); 2620 error = NULL; 2621 out: 2622 return error; 2623 out_iput: 2624 iput(inode); 2625 goto out; 2626 } 2627 2628 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2629 { 2630 struct dentry *error; 2631 struct task_struct *task = get_proc_task(dir); 2632 const struct pid_entry *p, *last; 2633 2634 error = ERR_PTR(-ENOENT); 2635 2636 if (!task) 2637 goto out_no_task; 2638 2639 /* Lookup the directory entry */ 2640 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2641 for (p = proc_base_stuff; p <= last; p++) { 2642 if (p->len != dentry->d_name.len) 2643 continue; 2644 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2645 break; 2646 } 2647 if (p > last) 2648 goto out; 2649 2650 error = proc_base_instantiate(dir, dentry, task, p); 2651 2652 out: 2653 put_task_struct(task); 2654 out_no_task: 2655 return error; 2656 } 2657 2658 static int proc_base_fill_cache(struct file *filp, void *dirent, 2659 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2660 { 2661 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2662 proc_base_instantiate, task, p); 2663 } 2664 2665 #ifdef CONFIG_TASK_IO_ACCOUNTING 2666 static int do_io_accounting(struct task_struct *task, char *buffer, int whole) 2667 { 2668 struct task_io_accounting acct = task->ioac; 2669 unsigned long flags; 2670 2671 if (whole && lock_task_sighand(task, &flags)) { 2672 struct task_struct *t = task; 2673 2674 task_io_accounting_add(&acct, &task->signal->ioac); 2675 while_each_thread(task, t) 2676 task_io_accounting_add(&acct, &t->ioac); 2677 2678 unlock_task_sighand(task, &flags); 2679 } 2680 return sprintf(buffer, 2681 "rchar: %llu\n" 2682 "wchar: %llu\n" 2683 "syscr: %llu\n" 2684 "syscw: %llu\n" 2685 "read_bytes: %llu\n" 2686 "write_bytes: %llu\n" 2687 "cancelled_write_bytes: %llu\n", 2688 (unsigned long long)acct.rchar, 2689 (unsigned long long)acct.wchar, 2690 (unsigned long long)acct.syscr, 2691 (unsigned long long)acct.syscw, 2692 (unsigned long long)acct.read_bytes, 2693 (unsigned long long)acct.write_bytes, 2694 (unsigned long long)acct.cancelled_write_bytes); 2695 } 2696 2697 static int proc_tid_io_accounting(struct task_struct *task, char *buffer) 2698 { 2699 return do_io_accounting(task, buffer, 0); 2700 } 2701 2702 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer) 2703 { 2704 return do_io_accounting(task, buffer, 1); 2705 } 2706 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2707 2708 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2709 struct pid *pid, struct task_struct *task) 2710 { 2711 seq_printf(m, "%08x\n", task->personality); 2712 return 0; 2713 } 2714 2715 /* 2716 * Thread groups 2717 */ 2718 static const struct file_operations proc_task_operations; 2719 static const struct inode_operations proc_task_inode_operations; 2720 2721 static const struct pid_entry tgid_base_stuff[] = { 2722 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2723 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2724 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2725 #ifdef CONFIG_NET 2726 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2727 #endif 2728 REG("environ", S_IRUSR, proc_environ_operations), 2729 INF("auxv", S_IRUSR, proc_pid_auxv), 2730 ONE("status", S_IRUGO, proc_pid_status), 2731 ONE("personality", S_IRUSR, proc_pid_personality), 2732 INF("limits", S_IRUGO, proc_pid_limits), 2733 #ifdef CONFIG_SCHED_DEBUG 2734 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2735 #endif 2736 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2737 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2738 INF("syscall", S_IRUSR, proc_pid_syscall), 2739 #endif 2740 INF("cmdline", S_IRUGO, proc_pid_cmdline), 2741 ONE("stat", S_IRUGO, proc_tgid_stat), 2742 ONE("statm", S_IRUGO, proc_pid_statm), 2743 REG("maps", S_IRUGO, proc_maps_operations), 2744 #ifdef CONFIG_NUMA 2745 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 2746 #endif 2747 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2748 LNK("cwd", proc_cwd_link), 2749 LNK("root", proc_root_link), 2750 LNK("exe", proc_exe_link), 2751 REG("mounts", S_IRUGO, proc_mounts_operations), 2752 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2753 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2754 #ifdef CONFIG_PROC_PAGE_MONITOR 2755 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2756 REG("smaps", S_IRUGO, proc_smaps_operations), 2757 REG("pagemap", S_IRUSR, proc_pagemap_operations), 2758 #endif 2759 #ifdef CONFIG_SECURITY 2760 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2761 #endif 2762 #ifdef CONFIG_KALLSYMS 2763 INF("wchan", S_IRUGO, proc_pid_wchan), 2764 #endif 2765 #ifdef CONFIG_STACKTRACE 2766 ONE("stack", S_IRUSR, proc_pid_stack), 2767 #endif 2768 #ifdef CONFIG_SCHEDSTATS 2769 INF("schedstat", S_IRUGO, proc_pid_schedstat), 2770 #endif 2771 #ifdef CONFIG_LATENCYTOP 2772 REG("latency", S_IRUGO, proc_lstats_operations), 2773 #endif 2774 #ifdef CONFIG_PROC_PID_CPUSET 2775 REG("cpuset", S_IRUGO, proc_cpuset_operations), 2776 #endif 2777 #ifdef CONFIG_CGROUPS 2778 REG("cgroup", S_IRUGO, proc_cgroup_operations), 2779 #endif 2780 INF("oom_score", S_IRUGO, proc_oom_score), 2781 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 2782 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2783 #ifdef CONFIG_AUDITSYSCALL 2784 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2785 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2786 #endif 2787 #ifdef CONFIG_FAULT_INJECTION 2788 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2789 #endif 2790 #ifdef CONFIG_ELF_CORE 2791 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2792 #endif 2793 #ifdef CONFIG_TASK_IO_ACCOUNTING 2794 INF("io", S_IRUGO, proc_tgid_io_accounting), 2795 #endif 2796 }; 2797 2798 static int proc_tgid_base_readdir(struct file * filp, 2799 void * dirent, filldir_t filldir) 2800 { 2801 return proc_pident_readdir(filp,dirent,filldir, 2802 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2803 } 2804 2805 static const struct file_operations proc_tgid_base_operations = { 2806 .read = generic_read_dir, 2807 .readdir = proc_tgid_base_readdir, 2808 .llseek = default_llseek, 2809 }; 2810 2811 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2812 return proc_pident_lookup(dir, dentry, 2813 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2814 } 2815 2816 static const struct inode_operations proc_tgid_base_inode_operations = { 2817 .lookup = proc_tgid_base_lookup, 2818 .getattr = pid_getattr, 2819 .setattr = proc_setattr, 2820 }; 2821 2822 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2823 { 2824 struct dentry *dentry, *leader, *dir; 2825 char buf[PROC_NUMBUF]; 2826 struct qstr name; 2827 2828 name.name = buf; 2829 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2830 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2831 if (dentry) { 2832 shrink_dcache_parent(dentry); 2833 d_drop(dentry); 2834 dput(dentry); 2835 } 2836 2837 name.name = buf; 2838 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2839 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2840 if (!leader) 2841 goto out; 2842 2843 name.name = "task"; 2844 name.len = strlen(name.name); 2845 dir = d_hash_and_lookup(leader, &name); 2846 if (!dir) 2847 goto out_put_leader; 2848 2849 name.name = buf; 2850 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2851 dentry = d_hash_and_lookup(dir, &name); 2852 if (dentry) { 2853 shrink_dcache_parent(dentry); 2854 d_drop(dentry); 2855 dput(dentry); 2856 } 2857 2858 dput(dir); 2859 out_put_leader: 2860 dput(leader); 2861 out: 2862 return; 2863 } 2864 2865 /** 2866 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2867 * @task: task that should be flushed. 2868 * 2869 * When flushing dentries from proc, one needs to flush them from global 2870 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2871 * in. This call is supposed to do all of this job. 2872 * 2873 * Looks in the dcache for 2874 * /proc/@pid 2875 * /proc/@tgid/task/@pid 2876 * if either directory is present flushes it and all of it'ts children 2877 * from the dcache. 2878 * 2879 * It is safe and reasonable to cache /proc entries for a task until 2880 * that task exits. After that they just clog up the dcache with 2881 * useless entries, possibly causing useful dcache entries to be 2882 * flushed instead. This routine is proved to flush those useless 2883 * dcache entries at process exit time. 2884 * 2885 * NOTE: This routine is just an optimization so it does not guarantee 2886 * that no dcache entries will exist at process exit time it 2887 * just makes it very unlikely that any will persist. 2888 */ 2889 2890 void proc_flush_task(struct task_struct *task) 2891 { 2892 int i; 2893 struct pid *pid, *tgid; 2894 struct upid *upid; 2895 2896 pid = task_pid(task); 2897 tgid = task_tgid(task); 2898 2899 for (i = 0; i <= pid->level; i++) { 2900 upid = &pid->numbers[i]; 2901 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 2902 tgid->numbers[i].nr); 2903 } 2904 2905 upid = &pid->numbers[pid->level]; 2906 if (upid->nr == 1) 2907 pid_ns_release_proc(upid->ns); 2908 } 2909 2910 static struct dentry *proc_pid_instantiate(struct inode *dir, 2911 struct dentry * dentry, 2912 struct task_struct *task, const void *ptr) 2913 { 2914 struct dentry *error = ERR_PTR(-ENOENT); 2915 struct inode *inode; 2916 2917 inode = proc_pid_make_inode(dir->i_sb, task); 2918 if (!inode) 2919 goto out; 2920 2921 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2922 inode->i_op = &proc_tgid_base_inode_operations; 2923 inode->i_fop = &proc_tgid_base_operations; 2924 inode->i_flags|=S_IMMUTABLE; 2925 2926 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff, 2927 ARRAY_SIZE(tgid_base_stuff)); 2928 2929 dentry->d_op = &pid_dentry_operations; 2930 2931 d_add(dentry, inode); 2932 /* Close the race of the process dying before we return the dentry */ 2933 if (pid_revalidate(dentry, NULL)) 2934 error = NULL; 2935 out: 2936 return error; 2937 } 2938 2939 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2940 { 2941 struct dentry *result; 2942 struct task_struct *task; 2943 unsigned tgid; 2944 struct pid_namespace *ns; 2945 2946 result = proc_base_lookup(dir, dentry); 2947 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 2948 goto out; 2949 2950 tgid = name_to_int(dentry); 2951 if (tgid == ~0U) 2952 goto out; 2953 2954 ns = dentry->d_sb->s_fs_info; 2955 rcu_read_lock(); 2956 task = find_task_by_pid_ns(tgid, ns); 2957 if (task) 2958 get_task_struct(task); 2959 rcu_read_unlock(); 2960 if (!task) 2961 goto out; 2962 2963 result = proc_pid_instantiate(dir, dentry, task, NULL); 2964 put_task_struct(task); 2965 out: 2966 return result; 2967 } 2968 2969 /* 2970 * Find the first task with tgid >= tgid 2971 * 2972 */ 2973 struct tgid_iter { 2974 unsigned int tgid; 2975 struct task_struct *task; 2976 }; 2977 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 2978 { 2979 struct pid *pid; 2980 2981 if (iter.task) 2982 put_task_struct(iter.task); 2983 rcu_read_lock(); 2984 retry: 2985 iter.task = NULL; 2986 pid = find_ge_pid(iter.tgid, ns); 2987 if (pid) { 2988 iter.tgid = pid_nr_ns(pid, ns); 2989 iter.task = pid_task(pid, PIDTYPE_PID); 2990 /* What we to know is if the pid we have find is the 2991 * pid of a thread_group_leader. Testing for task 2992 * being a thread_group_leader is the obvious thing 2993 * todo but there is a window when it fails, due to 2994 * the pid transfer logic in de_thread. 2995 * 2996 * So we perform the straight forward test of seeing 2997 * if the pid we have found is the pid of a thread 2998 * group leader, and don't worry if the task we have 2999 * found doesn't happen to be a thread group leader. 3000 * As we don't care in the case of readdir. 3001 */ 3002 if (!iter.task || !has_group_leader_pid(iter.task)) { 3003 iter.tgid += 1; 3004 goto retry; 3005 } 3006 get_task_struct(iter.task); 3007 } 3008 rcu_read_unlock(); 3009 return iter; 3010 } 3011 3012 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 3013 3014 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3015 struct tgid_iter iter) 3016 { 3017 char name[PROC_NUMBUF]; 3018 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 3019 return proc_fill_cache(filp, dirent, filldir, name, len, 3020 proc_pid_instantiate, iter.task, NULL); 3021 } 3022 3023 /* for the /proc/ directory itself, after non-process stuff has been done */ 3024 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 3025 { 3026 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; 3027 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode); 3028 struct tgid_iter iter; 3029 struct pid_namespace *ns; 3030 3031 if (!reaper) 3032 goto out_no_task; 3033 3034 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 3035 const struct pid_entry *p = &proc_base_stuff[nr]; 3036 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 3037 goto out; 3038 } 3039 3040 ns = filp->f_dentry->d_sb->s_fs_info; 3041 iter.task = NULL; 3042 iter.tgid = filp->f_pos - TGID_OFFSET; 3043 for (iter = next_tgid(ns, iter); 3044 iter.task; 3045 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3046 filp->f_pos = iter.tgid + TGID_OFFSET; 3047 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) { 3048 put_task_struct(iter.task); 3049 goto out; 3050 } 3051 } 3052 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 3053 out: 3054 put_task_struct(reaper); 3055 out_no_task: 3056 return 0; 3057 } 3058 3059 /* 3060 * Tasks 3061 */ 3062 static const struct pid_entry tid_base_stuff[] = { 3063 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3064 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3065 REG("environ", S_IRUSR, proc_environ_operations), 3066 INF("auxv", S_IRUSR, proc_pid_auxv), 3067 ONE("status", S_IRUGO, proc_pid_status), 3068 ONE("personality", S_IRUSR, proc_pid_personality), 3069 INF("limits", S_IRUGO, proc_pid_limits), 3070 #ifdef CONFIG_SCHED_DEBUG 3071 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3072 #endif 3073 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3074 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3075 INF("syscall", S_IRUSR, proc_pid_syscall), 3076 #endif 3077 INF("cmdline", S_IRUGO, proc_pid_cmdline), 3078 ONE("stat", S_IRUGO, proc_tid_stat), 3079 ONE("statm", S_IRUGO, proc_pid_statm), 3080 REG("maps", S_IRUGO, proc_maps_operations), 3081 #ifdef CONFIG_NUMA 3082 REG("numa_maps", S_IRUGO, proc_numa_maps_operations), 3083 #endif 3084 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3085 LNK("cwd", proc_cwd_link), 3086 LNK("root", proc_root_link), 3087 LNK("exe", proc_exe_link), 3088 REG("mounts", S_IRUGO, proc_mounts_operations), 3089 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3090 #ifdef CONFIG_PROC_PAGE_MONITOR 3091 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3092 REG("smaps", S_IRUGO, proc_smaps_operations), 3093 REG("pagemap", S_IRUSR, proc_pagemap_operations), 3094 #endif 3095 #ifdef CONFIG_SECURITY 3096 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3097 #endif 3098 #ifdef CONFIG_KALLSYMS 3099 INF("wchan", S_IRUGO, proc_pid_wchan), 3100 #endif 3101 #ifdef CONFIG_STACKTRACE 3102 ONE("stack", S_IRUSR, proc_pid_stack), 3103 #endif 3104 #ifdef CONFIG_SCHEDSTATS 3105 INF("schedstat", S_IRUGO, proc_pid_schedstat), 3106 #endif 3107 #ifdef CONFIG_LATENCYTOP 3108 REG("latency", S_IRUGO, proc_lstats_operations), 3109 #endif 3110 #ifdef CONFIG_PROC_PID_CPUSET 3111 REG("cpuset", S_IRUGO, proc_cpuset_operations), 3112 #endif 3113 #ifdef CONFIG_CGROUPS 3114 REG("cgroup", S_IRUGO, proc_cgroup_operations), 3115 #endif 3116 INF("oom_score", S_IRUGO, proc_oom_score), 3117 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 3118 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3119 #ifdef CONFIG_AUDITSYSCALL 3120 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3121 REG("sessionid", S_IRUSR, proc_sessionid_operations), 3122 #endif 3123 #ifdef CONFIG_FAULT_INJECTION 3124 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3125 #endif 3126 #ifdef CONFIG_TASK_IO_ACCOUNTING 3127 INF("io", S_IRUGO, proc_tid_io_accounting), 3128 #endif 3129 }; 3130 3131 static int proc_tid_base_readdir(struct file * filp, 3132 void * dirent, filldir_t filldir) 3133 { 3134 return proc_pident_readdir(filp,dirent,filldir, 3135 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 3136 } 3137 3138 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 3139 return proc_pident_lookup(dir, dentry, 3140 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3141 } 3142 3143 static const struct file_operations proc_tid_base_operations = { 3144 .read = generic_read_dir, 3145 .readdir = proc_tid_base_readdir, 3146 .llseek = default_llseek, 3147 }; 3148 3149 static const struct inode_operations proc_tid_base_inode_operations = { 3150 .lookup = proc_tid_base_lookup, 3151 .getattr = pid_getattr, 3152 .setattr = proc_setattr, 3153 }; 3154 3155 static struct dentry *proc_task_instantiate(struct inode *dir, 3156 struct dentry *dentry, struct task_struct *task, const void *ptr) 3157 { 3158 struct dentry *error = ERR_PTR(-ENOENT); 3159 struct inode *inode; 3160 inode = proc_pid_make_inode(dir->i_sb, task); 3161 3162 if (!inode) 3163 goto out; 3164 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3165 inode->i_op = &proc_tid_base_inode_operations; 3166 inode->i_fop = &proc_tid_base_operations; 3167 inode->i_flags|=S_IMMUTABLE; 3168 3169 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff, 3170 ARRAY_SIZE(tid_base_stuff)); 3171 3172 dentry->d_op = &pid_dentry_operations; 3173 3174 d_add(dentry, inode); 3175 /* Close the race of the process dying before we return the dentry */ 3176 if (pid_revalidate(dentry, NULL)) 3177 error = NULL; 3178 out: 3179 return error; 3180 } 3181 3182 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 3183 { 3184 struct dentry *result = ERR_PTR(-ENOENT); 3185 struct task_struct *task; 3186 struct task_struct *leader = get_proc_task(dir); 3187 unsigned tid; 3188 struct pid_namespace *ns; 3189 3190 if (!leader) 3191 goto out_no_task; 3192 3193 tid = name_to_int(dentry); 3194 if (tid == ~0U) 3195 goto out; 3196 3197 ns = dentry->d_sb->s_fs_info; 3198 rcu_read_lock(); 3199 task = find_task_by_pid_ns(tid, ns); 3200 if (task) 3201 get_task_struct(task); 3202 rcu_read_unlock(); 3203 if (!task) 3204 goto out; 3205 if (!same_thread_group(leader, task)) 3206 goto out_drop_task; 3207 3208 result = proc_task_instantiate(dir, dentry, task, NULL); 3209 out_drop_task: 3210 put_task_struct(task); 3211 out: 3212 put_task_struct(leader); 3213 out_no_task: 3214 return result; 3215 } 3216 3217 /* 3218 * Find the first tid of a thread group to return to user space. 3219 * 3220 * Usually this is just the thread group leader, but if the users 3221 * buffer was too small or there was a seek into the middle of the 3222 * directory we have more work todo. 3223 * 3224 * In the case of a short read we start with find_task_by_pid. 3225 * 3226 * In the case of a seek we start with the leader and walk nr 3227 * threads past it. 3228 */ 3229 static struct task_struct *first_tid(struct task_struct *leader, 3230 int tid, int nr, struct pid_namespace *ns) 3231 { 3232 struct task_struct *pos; 3233 3234 rcu_read_lock(); 3235 /* Attempt to start with the pid of a thread */ 3236 if (tid && (nr > 0)) { 3237 pos = find_task_by_pid_ns(tid, ns); 3238 if (pos && (pos->group_leader == leader)) 3239 goto found; 3240 } 3241 3242 /* If nr exceeds the number of threads there is nothing todo */ 3243 pos = NULL; 3244 if (nr && nr >= get_nr_threads(leader)) 3245 goto out; 3246 3247 /* If we haven't found our starting place yet start 3248 * with the leader and walk nr threads forward. 3249 */ 3250 for (pos = leader; nr > 0; --nr) { 3251 pos = next_thread(pos); 3252 if (pos == leader) { 3253 pos = NULL; 3254 goto out; 3255 } 3256 } 3257 found: 3258 get_task_struct(pos); 3259 out: 3260 rcu_read_unlock(); 3261 return pos; 3262 } 3263 3264 /* 3265 * Find the next thread in the thread list. 3266 * Return NULL if there is an error or no next thread. 3267 * 3268 * The reference to the input task_struct is released. 3269 */ 3270 static struct task_struct *next_tid(struct task_struct *start) 3271 { 3272 struct task_struct *pos = NULL; 3273 rcu_read_lock(); 3274 if (pid_alive(start)) { 3275 pos = next_thread(start); 3276 if (thread_group_leader(pos)) 3277 pos = NULL; 3278 else 3279 get_task_struct(pos); 3280 } 3281 rcu_read_unlock(); 3282 put_task_struct(start); 3283 return pos; 3284 } 3285 3286 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3287 struct task_struct *task, int tid) 3288 { 3289 char name[PROC_NUMBUF]; 3290 int len = snprintf(name, sizeof(name), "%d", tid); 3291 return proc_fill_cache(filp, dirent, filldir, name, len, 3292 proc_task_instantiate, task, NULL); 3293 } 3294 3295 /* for the /proc/TGID/task/ directories */ 3296 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 3297 { 3298 struct dentry *dentry = filp->f_path.dentry; 3299 struct inode *inode = dentry->d_inode; 3300 struct task_struct *leader = NULL; 3301 struct task_struct *task; 3302 int retval = -ENOENT; 3303 ino_t ino; 3304 int tid; 3305 struct pid_namespace *ns; 3306 3307 task = get_proc_task(inode); 3308 if (!task) 3309 goto out_no_task; 3310 rcu_read_lock(); 3311 if (pid_alive(task)) { 3312 leader = task->group_leader; 3313 get_task_struct(leader); 3314 } 3315 rcu_read_unlock(); 3316 put_task_struct(task); 3317 if (!leader) 3318 goto out_no_task; 3319 retval = 0; 3320 3321 switch ((unsigned long)filp->f_pos) { 3322 case 0: 3323 ino = inode->i_ino; 3324 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0) 3325 goto out; 3326 filp->f_pos++; 3327 /* fall through */ 3328 case 1: 3329 ino = parent_ino(dentry); 3330 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0) 3331 goto out; 3332 filp->f_pos++; 3333 /* fall through */ 3334 } 3335 3336 /* f_version caches the tgid value that the last readdir call couldn't 3337 * return. lseek aka telldir automagically resets f_version to 0. 3338 */ 3339 ns = filp->f_dentry->d_sb->s_fs_info; 3340 tid = (int)filp->f_version; 3341 filp->f_version = 0; 3342 for (task = first_tid(leader, tid, filp->f_pos - 2, ns); 3343 task; 3344 task = next_tid(task), filp->f_pos++) { 3345 tid = task_pid_nr_ns(task, ns); 3346 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 3347 /* returning this tgid failed, save it as the first 3348 * pid for the next readir call */ 3349 filp->f_version = (u64)tid; 3350 put_task_struct(task); 3351 break; 3352 } 3353 } 3354 out: 3355 put_task_struct(leader); 3356 out_no_task: 3357 return retval; 3358 } 3359 3360 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3361 { 3362 struct inode *inode = dentry->d_inode; 3363 struct task_struct *p = get_proc_task(inode); 3364 generic_fillattr(inode, stat); 3365 3366 if (p) { 3367 stat->nlink += get_nr_threads(p); 3368 put_task_struct(p); 3369 } 3370 3371 return 0; 3372 } 3373 3374 static const struct inode_operations proc_task_inode_operations = { 3375 .lookup = proc_task_lookup, 3376 .getattr = proc_task_getattr, 3377 .setattr = proc_setattr, 3378 }; 3379 3380 static const struct file_operations proc_task_operations = { 3381 .read = generic_read_dir, 3382 .readdir = proc_task_readdir, 3383 .llseek = default_llseek, 3384 }; 3385