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