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