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_adjust_read(struct file *file, char __user *buf, 877 size_t count, loff_t *ppos) 878 { 879 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 880 char buffer[PROC_NUMBUF]; 881 size_t len; 882 int oom_adjust = OOM_DISABLE; 883 unsigned long flags; 884 885 if (!task) 886 return -ESRCH; 887 888 if (lock_task_sighand(task, &flags)) { 889 oom_adjust = task->signal->oom_adj; 890 unlock_task_sighand(task, &flags); 891 } 892 893 put_task_struct(task); 894 895 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); 896 897 return simple_read_from_buffer(buf, count, ppos, buffer, len); 898 } 899 900 static ssize_t oom_adjust_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_adjust; 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_adjust); 918 if (err) 919 goto out; 920 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && 921 oom_adjust != 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 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) { 944 err = -EACCES; 945 goto err_sighand; 946 } 947 948 /* 949 * Warn that /proc/pid/oom_adj is deprecated, see 950 * Documentation/feature-removal-schedule.txt. 951 */ 952 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n", 953 current->comm, task_pid_nr(current), task_pid_nr(task), 954 task_pid_nr(task)); 955 task->signal->oom_adj = oom_adjust; 956 /* 957 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum 958 * value is always attainable. 959 */ 960 if (task->signal->oom_adj == OOM_ADJUST_MAX) 961 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX; 962 else 963 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) / 964 -OOM_DISABLE; 965 trace_oom_score_adj_update(task); 966 err_sighand: 967 unlock_task_sighand(task, &flags); 968 err_task_lock: 969 task_unlock(task); 970 put_task_struct(task); 971 out: 972 return err < 0 ? err : count; 973 } 974 975 static const struct file_operations proc_oom_adjust_operations = { 976 .read = oom_adjust_read, 977 .write = oom_adjust_write, 978 .llseek = generic_file_llseek, 979 }; 980 981 static ssize_t oom_score_adj_read(struct file *file, char __user *buf, 982 size_t count, loff_t *ppos) 983 { 984 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 985 char buffer[PROC_NUMBUF]; 986 int oom_score_adj = OOM_SCORE_ADJ_MIN; 987 unsigned long flags; 988 size_t len; 989 990 if (!task) 991 return -ESRCH; 992 if (lock_task_sighand(task, &flags)) { 993 oom_score_adj = task->signal->oom_score_adj; 994 unlock_task_sighand(task, &flags); 995 } 996 put_task_struct(task); 997 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj); 998 return simple_read_from_buffer(buf, count, ppos, buffer, len); 999 } 1000 1001 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf, 1002 size_t count, loff_t *ppos) 1003 { 1004 struct task_struct *task; 1005 char buffer[PROC_NUMBUF]; 1006 unsigned long flags; 1007 int oom_score_adj; 1008 int err; 1009 1010 memset(buffer, 0, sizeof(buffer)); 1011 if (count > sizeof(buffer) - 1) 1012 count = sizeof(buffer) - 1; 1013 if (copy_from_user(buffer, buf, count)) { 1014 err = -EFAULT; 1015 goto out; 1016 } 1017 1018 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj); 1019 if (err) 1020 goto out; 1021 if (oom_score_adj < OOM_SCORE_ADJ_MIN || 1022 oom_score_adj > OOM_SCORE_ADJ_MAX) { 1023 err = -EINVAL; 1024 goto out; 1025 } 1026 1027 task = get_proc_task(file->f_path.dentry->d_inode); 1028 if (!task) { 1029 err = -ESRCH; 1030 goto out; 1031 } 1032 1033 task_lock(task); 1034 if (!task->mm) { 1035 err = -EINVAL; 1036 goto err_task_lock; 1037 } 1038 1039 if (!lock_task_sighand(task, &flags)) { 1040 err = -ESRCH; 1041 goto err_task_lock; 1042 } 1043 1044 if (oom_score_adj < task->signal->oom_score_adj_min && 1045 !capable(CAP_SYS_RESOURCE)) { 1046 err = -EACCES; 1047 goto err_sighand; 1048 } 1049 1050 task->signal->oom_score_adj = oom_score_adj; 1051 if (has_capability_noaudit(current, CAP_SYS_RESOURCE)) 1052 task->signal->oom_score_adj_min = oom_score_adj; 1053 trace_oom_score_adj_update(task); 1054 /* 1055 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is 1056 * always attainable. 1057 */ 1058 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) 1059 task->signal->oom_adj = OOM_DISABLE; 1060 else 1061 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) / 1062 OOM_SCORE_ADJ_MAX; 1063 err_sighand: 1064 unlock_task_sighand(task, &flags); 1065 err_task_lock: 1066 task_unlock(task); 1067 put_task_struct(task); 1068 out: 1069 return err < 0 ? err : count; 1070 } 1071 1072 static const struct file_operations proc_oom_score_adj_operations = { 1073 .read = oom_score_adj_read, 1074 .write = oom_score_adj_write, 1075 .llseek = default_llseek, 1076 }; 1077 1078 #ifdef CONFIG_AUDITSYSCALL 1079 #define TMPBUFLEN 21 1080 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 1081 size_t count, loff_t *ppos) 1082 { 1083 struct inode * inode = file->f_path.dentry->d_inode; 1084 struct task_struct *task = get_proc_task(inode); 1085 ssize_t length; 1086 char tmpbuf[TMPBUFLEN]; 1087 1088 if (!task) 1089 return -ESRCH; 1090 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1091 from_kuid(file->f_cred->user_ns, 1092 audit_get_loginuid(task))); 1093 put_task_struct(task); 1094 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1095 } 1096 1097 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 1098 size_t count, loff_t *ppos) 1099 { 1100 struct inode * inode = file->f_path.dentry->d_inode; 1101 char *page, *tmp; 1102 ssize_t length; 1103 uid_t loginuid; 1104 kuid_t kloginuid; 1105 1106 rcu_read_lock(); 1107 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { 1108 rcu_read_unlock(); 1109 return -EPERM; 1110 } 1111 rcu_read_unlock(); 1112 1113 if (count >= PAGE_SIZE) 1114 count = PAGE_SIZE - 1; 1115 1116 if (*ppos != 0) { 1117 /* No partial writes. */ 1118 return -EINVAL; 1119 } 1120 page = (char*)__get_free_page(GFP_TEMPORARY); 1121 if (!page) 1122 return -ENOMEM; 1123 length = -EFAULT; 1124 if (copy_from_user(page, buf, count)) 1125 goto out_free_page; 1126 1127 page[count] = '\0'; 1128 loginuid = simple_strtoul(page, &tmp, 10); 1129 if (tmp == page) { 1130 length = -EINVAL; 1131 goto out_free_page; 1132 1133 } 1134 kloginuid = make_kuid(file->f_cred->user_ns, loginuid); 1135 if (!uid_valid(kloginuid)) { 1136 length = -EINVAL; 1137 goto out_free_page; 1138 } 1139 1140 length = audit_set_loginuid(kloginuid); 1141 if (likely(length == 0)) 1142 length = count; 1143 1144 out_free_page: 1145 free_page((unsigned long) page); 1146 return length; 1147 } 1148 1149 static const struct file_operations proc_loginuid_operations = { 1150 .read = proc_loginuid_read, 1151 .write = proc_loginuid_write, 1152 .llseek = generic_file_llseek, 1153 }; 1154 1155 static ssize_t proc_sessionid_read(struct file * file, char __user * buf, 1156 size_t count, loff_t *ppos) 1157 { 1158 struct inode * inode = file->f_path.dentry->d_inode; 1159 struct task_struct *task = get_proc_task(inode); 1160 ssize_t length; 1161 char tmpbuf[TMPBUFLEN]; 1162 1163 if (!task) 1164 return -ESRCH; 1165 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 1166 audit_get_sessionid(task)); 1167 put_task_struct(task); 1168 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 1169 } 1170 1171 static const struct file_operations proc_sessionid_operations = { 1172 .read = proc_sessionid_read, 1173 .llseek = generic_file_llseek, 1174 }; 1175 #endif 1176 1177 #ifdef CONFIG_FAULT_INJECTION 1178 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1179 size_t count, loff_t *ppos) 1180 { 1181 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1182 char buffer[PROC_NUMBUF]; 1183 size_t len; 1184 int make_it_fail; 1185 1186 if (!task) 1187 return -ESRCH; 1188 make_it_fail = task->make_it_fail; 1189 put_task_struct(task); 1190 1191 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1192 1193 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1194 } 1195 1196 static ssize_t proc_fault_inject_write(struct file * file, 1197 const char __user * buf, size_t count, loff_t *ppos) 1198 { 1199 struct task_struct *task; 1200 char buffer[PROC_NUMBUF], *end; 1201 int make_it_fail; 1202 1203 if (!capable(CAP_SYS_RESOURCE)) 1204 return -EPERM; 1205 memset(buffer, 0, sizeof(buffer)); 1206 if (count > sizeof(buffer) - 1) 1207 count = sizeof(buffer) - 1; 1208 if (copy_from_user(buffer, buf, count)) 1209 return -EFAULT; 1210 make_it_fail = simple_strtol(strstrip(buffer), &end, 0); 1211 if (*end) 1212 return -EINVAL; 1213 task = get_proc_task(file->f_dentry->d_inode); 1214 if (!task) 1215 return -ESRCH; 1216 task->make_it_fail = make_it_fail; 1217 put_task_struct(task); 1218 1219 return count; 1220 } 1221 1222 static const struct file_operations proc_fault_inject_operations = { 1223 .read = proc_fault_inject_read, 1224 .write = proc_fault_inject_write, 1225 .llseek = generic_file_llseek, 1226 }; 1227 #endif 1228 1229 1230 #ifdef CONFIG_SCHED_DEBUG 1231 /* 1232 * Print out various scheduling related per-task fields: 1233 */ 1234 static int sched_show(struct seq_file *m, void *v) 1235 { 1236 struct inode *inode = m->private; 1237 struct task_struct *p; 1238 1239 p = get_proc_task(inode); 1240 if (!p) 1241 return -ESRCH; 1242 proc_sched_show_task(p, m); 1243 1244 put_task_struct(p); 1245 1246 return 0; 1247 } 1248 1249 static ssize_t 1250 sched_write(struct file *file, const char __user *buf, 1251 size_t count, loff_t *offset) 1252 { 1253 struct inode *inode = file->f_path.dentry->d_inode; 1254 struct task_struct *p; 1255 1256 p = get_proc_task(inode); 1257 if (!p) 1258 return -ESRCH; 1259 proc_sched_set_task(p); 1260 1261 put_task_struct(p); 1262 1263 return count; 1264 } 1265 1266 static int sched_open(struct inode *inode, struct file *filp) 1267 { 1268 return single_open(filp, sched_show, inode); 1269 } 1270 1271 static const struct file_operations proc_pid_sched_operations = { 1272 .open = sched_open, 1273 .read = seq_read, 1274 .write = sched_write, 1275 .llseek = seq_lseek, 1276 .release = single_release, 1277 }; 1278 1279 #endif 1280 1281 #ifdef CONFIG_SCHED_AUTOGROUP 1282 /* 1283 * Print out autogroup related information: 1284 */ 1285 static int sched_autogroup_show(struct seq_file *m, void *v) 1286 { 1287 struct inode *inode = m->private; 1288 struct task_struct *p; 1289 1290 p = get_proc_task(inode); 1291 if (!p) 1292 return -ESRCH; 1293 proc_sched_autogroup_show_task(p, m); 1294 1295 put_task_struct(p); 1296 1297 return 0; 1298 } 1299 1300 static ssize_t 1301 sched_autogroup_write(struct file *file, const char __user *buf, 1302 size_t count, loff_t *offset) 1303 { 1304 struct inode *inode = file->f_path.dentry->d_inode; 1305 struct task_struct *p; 1306 char buffer[PROC_NUMBUF]; 1307 int nice; 1308 int err; 1309 1310 memset(buffer, 0, sizeof(buffer)); 1311 if (count > sizeof(buffer) - 1) 1312 count = sizeof(buffer) - 1; 1313 if (copy_from_user(buffer, buf, count)) 1314 return -EFAULT; 1315 1316 err = kstrtoint(strstrip(buffer), 0, &nice); 1317 if (err < 0) 1318 return err; 1319 1320 p = get_proc_task(inode); 1321 if (!p) 1322 return -ESRCH; 1323 1324 err = proc_sched_autogroup_set_nice(p, nice); 1325 if (err) 1326 count = err; 1327 1328 put_task_struct(p); 1329 1330 return count; 1331 } 1332 1333 static int sched_autogroup_open(struct inode *inode, struct file *filp) 1334 { 1335 int ret; 1336 1337 ret = single_open(filp, sched_autogroup_show, NULL); 1338 if (!ret) { 1339 struct seq_file *m = filp->private_data; 1340 1341 m->private = inode; 1342 } 1343 return ret; 1344 } 1345 1346 static const struct file_operations proc_pid_sched_autogroup_operations = { 1347 .open = sched_autogroup_open, 1348 .read = seq_read, 1349 .write = sched_autogroup_write, 1350 .llseek = seq_lseek, 1351 .release = single_release, 1352 }; 1353 1354 #endif /* CONFIG_SCHED_AUTOGROUP */ 1355 1356 static ssize_t comm_write(struct file *file, const char __user *buf, 1357 size_t count, loff_t *offset) 1358 { 1359 struct inode *inode = file->f_path.dentry->d_inode; 1360 struct task_struct *p; 1361 char buffer[TASK_COMM_LEN]; 1362 1363 memset(buffer, 0, sizeof(buffer)); 1364 if (count > sizeof(buffer) - 1) 1365 count = sizeof(buffer) - 1; 1366 if (copy_from_user(buffer, buf, count)) 1367 return -EFAULT; 1368 1369 p = get_proc_task(inode); 1370 if (!p) 1371 return -ESRCH; 1372 1373 if (same_thread_group(current, p)) 1374 set_task_comm(p, buffer); 1375 else 1376 count = -EINVAL; 1377 1378 put_task_struct(p); 1379 1380 return count; 1381 } 1382 1383 static int comm_show(struct seq_file *m, void *v) 1384 { 1385 struct inode *inode = m->private; 1386 struct task_struct *p; 1387 1388 p = get_proc_task(inode); 1389 if (!p) 1390 return -ESRCH; 1391 1392 task_lock(p); 1393 seq_printf(m, "%s\n", p->comm); 1394 task_unlock(p); 1395 1396 put_task_struct(p); 1397 1398 return 0; 1399 } 1400 1401 static int comm_open(struct inode *inode, struct file *filp) 1402 { 1403 return single_open(filp, comm_show, inode); 1404 } 1405 1406 static const struct file_operations proc_pid_set_comm_operations = { 1407 .open = comm_open, 1408 .read = seq_read, 1409 .write = comm_write, 1410 .llseek = seq_lseek, 1411 .release = single_release, 1412 }; 1413 1414 static int proc_exe_link(struct dentry *dentry, struct path *exe_path) 1415 { 1416 struct task_struct *task; 1417 struct mm_struct *mm; 1418 struct file *exe_file; 1419 1420 task = get_proc_task(dentry->d_inode); 1421 if (!task) 1422 return -ENOENT; 1423 mm = get_task_mm(task); 1424 put_task_struct(task); 1425 if (!mm) 1426 return -ENOENT; 1427 exe_file = get_mm_exe_file(mm); 1428 mmput(mm); 1429 if (exe_file) { 1430 *exe_path = exe_file->f_path; 1431 path_get(&exe_file->f_path); 1432 fput(exe_file); 1433 return 0; 1434 } else 1435 return -ENOENT; 1436 } 1437 1438 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1439 { 1440 struct inode *inode = dentry->d_inode; 1441 struct path path; 1442 int error = -EACCES; 1443 1444 /* Are we allowed to snoop on the tasks file descriptors? */ 1445 if (!proc_fd_access_allowed(inode)) 1446 goto out; 1447 1448 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1449 if (error) 1450 goto out; 1451 1452 nd_jump_link(nd, &path); 1453 return NULL; 1454 out: 1455 return ERR_PTR(error); 1456 } 1457 1458 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) 1459 { 1460 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1461 char *pathname; 1462 int len; 1463 1464 if (!tmp) 1465 return -ENOMEM; 1466 1467 pathname = d_path(path, tmp, PAGE_SIZE); 1468 len = PTR_ERR(pathname); 1469 if (IS_ERR(pathname)) 1470 goto out; 1471 len = tmp + PAGE_SIZE - 1 - pathname; 1472 1473 if (len > buflen) 1474 len = buflen; 1475 if (copy_to_user(buffer, pathname, len)) 1476 len = -EFAULT; 1477 out: 1478 free_page((unsigned long)tmp); 1479 return len; 1480 } 1481 1482 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1483 { 1484 int error = -EACCES; 1485 struct inode *inode = dentry->d_inode; 1486 struct path path; 1487 1488 /* Are we allowed to snoop on the tasks file descriptors? */ 1489 if (!proc_fd_access_allowed(inode)) 1490 goto out; 1491 1492 error = PROC_I(inode)->op.proc_get_link(dentry, &path); 1493 if (error) 1494 goto out; 1495 1496 error = do_proc_readlink(&path, buffer, buflen); 1497 path_put(&path); 1498 out: 1499 return error; 1500 } 1501 1502 const struct inode_operations proc_pid_link_inode_operations = { 1503 .readlink = proc_pid_readlink, 1504 .follow_link = proc_pid_follow_link, 1505 .setattr = proc_setattr, 1506 }; 1507 1508 1509 /* building an inode */ 1510 1511 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1512 { 1513 struct inode * inode; 1514 struct proc_inode *ei; 1515 const struct cred *cred; 1516 1517 /* We need a new inode */ 1518 1519 inode = new_inode(sb); 1520 if (!inode) 1521 goto out; 1522 1523 /* Common stuff */ 1524 ei = PROC_I(inode); 1525 inode->i_ino = get_next_ino(); 1526 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1527 inode->i_op = &proc_def_inode_operations; 1528 1529 /* 1530 * grab the reference to task. 1531 */ 1532 ei->pid = get_task_pid(task, PIDTYPE_PID); 1533 if (!ei->pid) 1534 goto out_unlock; 1535 1536 if (task_dumpable(task)) { 1537 rcu_read_lock(); 1538 cred = __task_cred(task); 1539 inode->i_uid = cred->euid; 1540 inode->i_gid = cred->egid; 1541 rcu_read_unlock(); 1542 } 1543 security_task_to_inode(task, inode); 1544 1545 out: 1546 return inode; 1547 1548 out_unlock: 1549 iput(inode); 1550 return NULL; 1551 } 1552 1553 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1554 { 1555 struct inode *inode = dentry->d_inode; 1556 struct task_struct *task; 1557 const struct cred *cred; 1558 struct pid_namespace *pid = dentry->d_sb->s_fs_info; 1559 1560 generic_fillattr(inode, stat); 1561 1562 rcu_read_lock(); 1563 stat->uid = GLOBAL_ROOT_UID; 1564 stat->gid = GLOBAL_ROOT_GID; 1565 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1566 if (task) { 1567 if (!has_pid_permissions(pid, task, 2)) { 1568 rcu_read_unlock(); 1569 /* 1570 * This doesn't prevent learning whether PID exists, 1571 * it only makes getattr() consistent with readdir(). 1572 */ 1573 return -ENOENT; 1574 } 1575 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1576 task_dumpable(task)) { 1577 cred = __task_cred(task); 1578 stat->uid = cred->euid; 1579 stat->gid = cred->egid; 1580 } 1581 } 1582 rcu_read_unlock(); 1583 return 0; 1584 } 1585 1586 /* dentry stuff */ 1587 1588 /* 1589 * Exceptional case: normally we are not allowed to unhash a busy 1590 * directory. In this case, however, we can do it - no aliasing problems 1591 * due to the way we treat inodes. 1592 * 1593 * Rewrite the inode's ownerships here because the owning task may have 1594 * performed a setuid(), etc. 1595 * 1596 * Before the /proc/pid/status file was created the only way to read 1597 * the effective uid of a /process was to stat /proc/pid. Reading 1598 * /proc/pid/status is slow enough that procps and other packages 1599 * kept stating /proc/pid. To keep the rules in /proc simple I have 1600 * made this apply to all per process world readable and executable 1601 * directories. 1602 */ 1603 int pid_revalidate(struct dentry *dentry, unsigned int flags) 1604 { 1605 struct inode *inode; 1606 struct task_struct *task; 1607 const struct cred *cred; 1608 1609 if (flags & LOOKUP_RCU) 1610 return -ECHILD; 1611 1612 inode = dentry->d_inode; 1613 task = get_proc_task(inode); 1614 1615 if (task) { 1616 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1617 task_dumpable(task)) { 1618 rcu_read_lock(); 1619 cred = __task_cred(task); 1620 inode->i_uid = cred->euid; 1621 inode->i_gid = cred->egid; 1622 rcu_read_unlock(); 1623 } else { 1624 inode->i_uid = GLOBAL_ROOT_UID; 1625 inode->i_gid = GLOBAL_ROOT_GID; 1626 } 1627 inode->i_mode &= ~(S_ISUID | S_ISGID); 1628 security_task_to_inode(task, inode); 1629 put_task_struct(task); 1630 return 1; 1631 } 1632 d_drop(dentry); 1633 return 0; 1634 } 1635 1636 const struct dentry_operations pid_dentry_operations = 1637 { 1638 .d_revalidate = pid_revalidate, 1639 .d_delete = pid_delete_dentry, 1640 }; 1641 1642 /* Lookups */ 1643 1644 /* 1645 * Fill a directory entry. 1646 * 1647 * If possible create the dcache entry and derive our inode number and 1648 * file type from dcache entry. 1649 * 1650 * Since all of the proc inode numbers are dynamically generated, the inode 1651 * numbers do not exist until the inode is cache. This means creating the 1652 * the dcache entry in readdir is necessary to keep the inode numbers 1653 * reported by readdir in sync with the inode numbers reported 1654 * by stat. 1655 */ 1656 int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1657 const char *name, int len, 1658 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1659 { 1660 struct dentry *child, *dir = filp->f_path.dentry; 1661 struct inode *inode; 1662 struct qstr qname; 1663 ino_t ino = 0; 1664 unsigned type = DT_UNKNOWN; 1665 1666 qname.name = name; 1667 qname.len = len; 1668 qname.hash = full_name_hash(name, len); 1669 1670 child = d_lookup(dir, &qname); 1671 if (!child) { 1672 struct dentry *new; 1673 new = d_alloc(dir, &qname); 1674 if (new) { 1675 child = instantiate(dir->d_inode, new, task, ptr); 1676 if (child) 1677 dput(new); 1678 else 1679 child = new; 1680 } 1681 } 1682 if (!child || IS_ERR(child) || !child->d_inode) 1683 goto end_instantiate; 1684 inode = child->d_inode; 1685 if (inode) { 1686 ino = inode->i_ino; 1687 type = inode->i_mode >> 12; 1688 } 1689 dput(child); 1690 end_instantiate: 1691 if (!ino) 1692 ino = find_inode_number(dir, &qname); 1693 if (!ino) 1694 ino = 1; 1695 return filldir(dirent, name, len, filp->f_pos, ino, type); 1696 } 1697 1698 #ifdef CONFIG_CHECKPOINT_RESTORE 1699 1700 /* 1701 * dname_to_vma_addr - maps a dentry name into two unsigned longs 1702 * which represent vma start and end addresses. 1703 */ 1704 static int dname_to_vma_addr(struct dentry *dentry, 1705 unsigned long *start, unsigned long *end) 1706 { 1707 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2) 1708 return -EINVAL; 1709 1710 return 0; 1711 } 1712 1713 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags) 1714 { 1715 unsigned long vm_start, vm_end; 1716 bool exact_vma_exists = false; 1717 struct mm_struct *mm = NULL; 1718 struct task_struct *task; 1719 const struct cred *cred; 1720 struct inode *inode; 1721 int status = 0; 1722 1723 if (flags & LOOKUP_RCU) 1724 return -ECHILD; 1725 1726 if (!capable(CAP_SYS_ADMIN)) { 1727 status = -EACCES; 1728 goto out_notask; 1729 } 1730 1731 inode = dentry->d_inode; 1732 task = get_proc_task(inode); 1733 if (!task) 1734 goto out_notask; 1735 1736 mm = mm_access(task, PTRACE_MODE_READ); 1737 if (IS_ERR_OR_NULL(mm)) 1738 goto out; 1739 1740 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) { 1741 down_read(&mm->mmap_sem); 1742 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end); 1743 up_read(&mm->mmap_sem); 1744 } 1745 1746 mmput(mm); 1747 1748 if (exact_vma_exists) { 1749 if (task_dumpable(task)) { 1750 rcu_read_lock(); 1751 cred = __task_cred(task); 1752 inode->i_uid = cred->euid; 1753 inode->i_gid = cred->egid; 1754 rcu_read_unlock(); 1755 } else { 1756 inode->i_uid = GLOBAL_ROOT_UID; 1757 inode->i_gid = GLOBAL_ROOT_GID; 1758 } 1759 security_task_to_inode(task, inode); 1760 status = 1; 1761 } 1762 1763 out: 1764 put_task_struct(task); 1765 1766 out_notask: 1767 if (status <= 0) 1768 d_drop(dentry); 1769 1770 return status; 1771 } 1772 1773 static const struct dentry_operations tid_map_files_dentry_operations = { 1774 .d_revalidate = map_files_d_revalidate, 1775 .d_delete = pid_delete_dentry, 1776 }; 1777 1778 static int proc_map_files_get_link(struct dentry *dentry, struct path *path) 1779 { 1780 unsigned long vm_start, vm_end; 1781 struct vm_area_struct *vma; 1782 struct task_struct *task; 1783 struct mm_struct *mm; 1784 int rc; 1785 1786 rc = -ENOENT; 1787 task = get_proc_task(dentry->d_inode); 1788 if (!task) 1789 goto out; 1790 1791 mm = get_task_mm(task); 1792 put_task_struct(task); 1793 if (!mm) 1794 goto out; 1795 1796 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end); 1797 if (rc) 1798 goto out_mmput; 1799 1800 down_read(&mm->mmap_sem); 1801 vma = find_exact_vma(mm, vm_start, vm_end); 1802 if (vma && vma->vm_file) { 1803 *path = vma->vm_file->f_path; 1804 path_get(path); 1805 rc = 0; 1806 } 1807 up_read(&mm->mmap_sem); 1808 1809 out_mmput: 1810 mmput(mm); 1811 out: 1812 return rc; 1813 } 1814 1815 struct map_files_info { 1816 fmode_t mode; 1817 unsigned long len; 1818 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */ 1819 }; 1820 1821 static struct dentry * 1822 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry, 1823 struct task_struct *task, const void *ptr) 1824 { 1825 fmode_t mode = (fmode_t)(unsigned long)ptr; 1826 struct proc_inode *ei; 1827 struct inode *inode; 1828 1829 inode = proc_pid_make_inode(dir->i_sb, task); 1830 if (!inode) 1831 return ERR_PTR(-ENOENT); 1832 1833 ei = PROC_I(inode); 1834 ei->op.proc_get_link = proc_map_files_get_link; 1835 1836 inode->i_op = &proc_pid_link_inode_operations; 1837 inode->i_size = 64; 1838 inode->i_mode = S_IFLNK; 1839 1840 if (mode & FMODE_READ) 1841 inode->i_mode |= S_IRUSR; 1842 if (mode & FMODE_WRITE) 1843 inode->i_mode |= S_IWUSR; 1844 1845 d_set_d_op(dentry, &tid_map_files_dentry_operations); 1846 d_add(dentry, inode); 1847 1848 return NULL; 1849 } 1850 1851 static struct dentry *proc_map_files_lookup(struct inode *dir, 1852 struct dentry *dentry, unsigned int flags) 1853 { 1854 unsigned long vm_start, vm_end; 1855 struct vm_area_struct *vma; 1856 struct task_struct *task; 1857 struct dentry *result; 1858 struct mm_struct *mm; 1859 1860 result = ERR_PTR(-EACCES); 1861 if (!capable(CAP_SYS_ADMIN)) 1862 goto out; 1863 1864 result = ERR_PTR(-ENOENT); 1865 task = get_proc_task(dir); 1866 if (!task) 1867 goto out; 1868 1869 result = ERR_PTR(-EACCES); 1870 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 1871 goto out_put_task; 1872 1873 result = ERR_PTR(-ENOENT); 1874 if (dname_to_vma_addr(dentry, &vm_start, &vm_end)) 1875 goto out_put_task; 1876 1877 mm = get_task_mm(task); 1878 if (!mm) 1879 goto out_put_task; 1880 1881 down_read(&mm->mmap_sem); 1882 vma = find_exact_vma(mm, vm_start, vm_end); 1883 if (!vma) 1884 goto out_no_vma; 1885 1886 result = proc_map_files_instantiate(dir, dentry, task, 1887 (void *)(unsigned long)vma->vm_file->f_mode); 1888 1889 out_no_vma: 1890 up_read(&mm->mmap_sem); 1891 mmput(mm); 1892 out_put_task: 1893 put_task_struct(task); 1894 out: 1895 return result; 1896 } 1897 1898 static const struct inode_operations proc_map_files_inode_operations = { 1899 .lookup = proc_map_files_lookup, 1900 .permission = proc_fd_permission, 1901 .setattr = proc_setattr, 1902 }; 1903 1904 static int 1905 proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir) 1906 { 1907 struct dentry *dentry = filp->f_path.dentry; 1908 struct inode *inode = dentry->d_inode; 1909 struct vm_area_struct *vma; 1910 struct task_struct *task; 1911 struct mm_struct *mm; 1912 ino_t ino; 1913 int ret; 1914 1915 ret = -EACCES; 1916 if (!capable(CAP_SYS_ADMIN)) 1917 goto out; 1918 1919 ret = -ENOENT; 1920 task = get_proc_task(inode); 1921 if (!task) 1922 goto out; 1923 1924 ret = -EACCES; 1925 if (!ptrace_may_access(task, PTRACE_MODE_READ)) 1926 goto out_put_task; 1927 1928 ret = 0; 1929 switch (filp->f_pos) { 1930 case 0: 1931 ino = inode->i_ino; 1932 if (filldir(dirent, ".", 1, 0, ino, DT_DIR) < 0) 1933 goto out_put_task; 1934 filp->f_pos++; 1935 case 1: 1936 ino = parent_ino(dentry); 1937 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 1938 goto out_put_task; 1939 filp->f_pos++; 1940 default: 1941 { 1942 unsigned long nr_files, pos, i; 1943 struct flex_array *fa = NULL; 1944 struct map_files_info info; 1945 struct map_files_info *p; 1946 1947 mm = get_task_mm(task); 1948 if (!mm) 1949 goto out_put_task; 1950 down_read(&mm->mmap_sem); 1951 1952 nr_files = 0; 1953 1954 /* 1955 * We need two passes here: 1956 * 1957 * 1) Collect vmas of mapped files with mmap_sem taken 1958 * 2) Release mmap_sem and instantiate entries 1959 * 1960 * otherwise we get lockdep complained, since filldir() 1961 * routine might require mmap_sem taken in might_fault(). 1962 */ 1963 1964 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) { 1965 if (vma->vm_file && ++pos > filp->f_pos) 1966 nr_files++; 1967 } 1968 1969 if (nr_files) { 1970 fa = flex_array_alloc(sizeof(info), nr_files, 1971 GFP_KERNEL); 1972 if (!fa || flex_array_prealloc(fa, 0, nr_files, 1973 GFP_KERNEL)) { 1974 ret = -ENOMEM; 1975 if (fa) 1976 flex_array_free(fa); 1977 up_read(&mm->mmap_sem); 1978 mmput(mm); 1979 goto out_put_task; 1980 } 1981 for (i = 0, vma = mm->mmap, pos = 2; vma; 1982 vma = vma->vm_next) { 1983 if (!vma->vm_file) 1984 continue; 1985 if (++pos <= filp->f_pos) 1986 continue; 1987 1988 info.mode = vma->vm_file->f_mode; 1989 info.len = snprintf(info.name, 1990 sizeof(info.name), "%lx-%lx", 1991 vma->vm_start, vma->vm_end); 1992 if (flex_array_put(fa, i++, &info, GFP_KERNEL)) 1993 BUG(); 1994 } 1995 } 1996 up_read(&mm->mmap_sem); 1997 1998 for (i = 0; i < nr_files; i++) { 1999 p = flex_array_get(fa, i); 2000 ret = proc_fill_cache(filp, dirent, filldir, 2001 p->name, p->len, 2002 proc_map_files_instantiate, 2003 task, 2004 (void *)(unsigned long)p->mode); 2005 if (ret) 2006 break; 2007 filp->f_pos++; 2008 } 2009 if (fa) 2010 flex_array_free(fa); 2011 mmput(mm); 2012 } 2013 } 2014 2015 out_put_task: 2016 put_task_struct(task); 2017 out: 2018 return ret; 2019 } 2020 2021 static const struct file_operations proc_map_files_operations = { 2022 .read = generic_read_dir, 2023 .readdir = proc_map_files_readdir, 2024 .llseek = default_llseek, 2025 }; 2026 2027 #endif /* CONFIG_CHECKPOINT_RESTORE */ 2028 2029 static struct dentry *proc_pident_instantiate(struct inode *dir, 2030 struct dentry *dentry, struct task_struct *task, const void *ptr) 2031 { 2032 const struct pid_entry *p = ptr; 2033 struct inode *inode; 2034 struct proc_inode *ei; 2035 struct dentry *error = ERR_PTR(-ENOENT); 2036 2037 inode = proc_pid_make_inode(dir->i_sb, task); 2038 if (!inode) 2039 goto out; 2040 2041 ei = PROC_I(inode); 2042 inode->i_mode = p->mode; 2043 if (S_ISDIR(inode->i_mode)) 2044 set_nlink(inode, 2); /* Use getattr to fix if necessary */ 2045 if (p->iop) 2046 inode->i_op = p->iop; 2047 if (p->fop) 2048 inode->i_fop = p->fop; 2049 ei->op = p->op; 2050 d_set_d_op(dentry, &pid_dentry_operations); 2051 d_add(dentry, inode); 2052 /* Close the race of the process dying before we return the dentry */ 2053 if (pid_revalidate(dentry, 0)) 2054 error = NULL; 2055 out: 2056 return error; 2057 } 2058 2059 static struct dentry *proc_pident_lookup(struct inode *dir, 2060 struct dentry *dentry, 2061 const struct pid_entry *ents, 2062 unsigned int nents) 2063 { 2064 struct dentry *error; 2065 struct task_struct *task = get_proc_task(dir); 2066 const struct pid_entry *p, *last; 2067 2068 error = ERR_PTR(-ENOENT); 2069 2070 if (!task) 2071 goto out_no_task; 2072 2073 /* 2074 * Yes, it does not scale. And it should not. Don't add 2075 * new entries into /proc/<tgid>/ without very good reasons. 2076 */ 2077 last = &ents[nents - 1]; 2078 for (p = ents; p <= last; p++) { 2079 if (p->len != dentry->d_name.len) 2080 continue; 2081 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2082 break; 2083 } 2084 if (p > last) 2085 goto out; 2086 2087 error = proc_pident_instantiate(dir, dentry, task, p); 2088 out: 2089 put_task_struct(task); 2090 out_no_task: 2091 return error; 2092 } 2093 2094 static int proc_pident_fill_cache(struct file *filp, void *dirent, 2095 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2096 { 2097 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2098 proc_pident_instantiate, task, p); 2099 } 2100 2101 static int proc_pident_readdir(struct file *filp, 2102 void *dirent, filldir_t filldir, 2103 const struct pid_entry *ents, unsigned int nents) 2104 { 2105 int i; 2106 struct dentry *dentry = filp->f_path.dentry; 2107 struct inode *inode = dentry->d_inode; 2108 struct task_struct *task = get_proc_task(inode); 2109 const struct pid_entry *p, *last; 2110 ino_t ino; 2111 int ret; 2112 2113 ret = -ENOENT; 2114 if (!task) 2115 goto out_no_task; 2116 2117 ret = 0; 2118 i = filp->f_pos; 2119 switch (i) { 2120 case 0: 2121 ino = inode->i_ino; 2122 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 2123 goto out; 2124 i++; 2125 filp->f_pos++; 2126 /* fall through */ 2127 case 1: 2128 ino = parent_ino(dentry); 2129 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 2130 goto out; 2131 i++; 2132 filp->f_pos++; 2133 /* fall through */ 2134 default: 2135 i -= 2; 2136 if (i >= nents) { 2137 ret = 1; 2138 goto out; 2139 } 2140 p = ents + i; 2141 last = &ents[nents - 1]; 2142 while (p <= last) { 2143 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 2144 goto out; 2145 filp->f_pos++; 2146 p++; 2147 } 2148 } 2149 2150 ret = 1; 2151 out: 2152 put_task_struct(task); 2153 out_no_task: 2154 return ret; 2155 } 2156 2157 #ifdef CONFIG_SECURITY 2158 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 2159 size_t count, loff_t *ppos) 2160 { 2161 struct inode * inode = file->f_path.dentry->d_inode; 2162 char *p = NULL; 2163 ssize_t length; 2164 struct task_struct *task = get_proc_task(inode); 2165 2166 if (!task) 2167 return -ESRCH; 2168 2169 length = security_getprocattr(task, 2170 (char*)file->f_path.dentry->d_name.name, 2171 &p); 2172 put_task_struct(task); 2173 if (length > 0) 2174 length = simple_read_from_buffer(buf, count, ppos, p, length); 2175 kfree(p); 2176 return length; 2177 } 2178 2179 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 2180 size_t count, loff_t *ppos) 2181 { 2182 struct inode * inode = file->f_path.dentry->d_inode; 2183 char *page; 2184 ssize_t length; 2185 struct task_struct *task = get_proc_task(inode); 2186 2187 length = -ESRCH; 2188 if (!task) 2189 goto out_no_task; 2190 if (count > PAGE_SIZE) 2191 count = PAGE_SIZE; 2192 2193 /* No partial writes. */ 2194 length = -EINVAL; 2195 if (*ppos != 0) 2196 goto out; 2197 2198 length = -ENOMEM; 2199 page = (char*)__get_free_page(GFP_TEMPORARY); 2200 if (!page) 2201 goto out; 2202 2203 length = -EFAULT; 2204 if (copy_from_user(page, buf, count)) 2205 goto out_free; 2206 2207 /* Guard against adverse ptrace interaction */ 2208 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex); 2209 if (length < 0) 2210 goto out_free; 2211 2212 length = security_setprocattr(task, 2213 (char*)file->f_path.dentry->d_name.name, 2214 (void*)page, count); 2215 mutex_unlock(&task->signal->cred_guard_mutex); 2216 out_free: 2217 free_page((unsigned long) page); 2218 out: 2219 put_task_struct(task); 2220 out_no_task: 2221 return length; 2222 } 2223 2224 static const struct file_operations proc_pid_attr_operations = { 2225 .read = proc_pid_attr_read, 2226 .write = proc_pid_attr_write, 2227 .llseek = generic_file_llseek, 2228 }; 2229 2230 static const struct pid_entry attr_dir_stuff[] = { 2231 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2232 REG("prev", S_IRUGO, proc_pid_attr_operations), 2233 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2234 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2235 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2236 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations), 2237 }; 2238 2239 static int proc_attr_dir_readdir(struct file * filp, 2240 void * dirent, filldir_t filldir) 2241 { 2242 return proc_pident_readdir(filp,dirent,filldir, 2243 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 2244 } 2245 2246 static const struct file_operations proc_attr_dir_operations = { 2247 .read = generic_read_dir, 2248 .readdir = proc_attr_dir_readdir, 2249 .llseek = default_llseek, 2250 }; 2251 2252 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 2253 struct dentry *dentry, unsigned int flags) 2254 { 2255 return proc_pident_lookup(dir, dentry, 2256 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2257 } 2258 2259 static const struct inode_operations proc_attr_dir_inode_operations = { 2260 .lookup = proc_attr_dir_lookup, 2261 .getattr = pid_getattr, 2262 .setattr = proc_setattr, 2263 }; 2264 2265 #endif 2266 2267 #ifdef CONFIG_ELF_CORE 2268 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2269 size_t count, loff_t *ppos) 2270 { 2271 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2272 struct mm_struct *mm; 2273 char buffer[PROC_NUMBUF]; 2274 size_t len; 2275 int ret; 2276 2277 if (!task) 2278 return -ESRCH; 2279 2280 ret = 0; 2281 mm = get_task_mm(task); 2282 if (mm) { 2283 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2284 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2285 MMF_DUMP_FILTER_SHIFT)); 2286 mmput(mm); 2287 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2288 } 2289 2290 put_task_struct(task); 2291 2292 return ret; 2293 } 2294 2295 static ssize_t proc_coredump_filter_write(struct file *file, 2296 const char __user *buf, 2297 size_t count, 2298 loff_t *ppos) 2299 { 2300 struct task_struct *task; 2301 struct mm_struct *mm; 2302 char buffer[PROC_NUMBUF], *end; 2303 unsigned int val; 2304 int ret; 2305 int i; 2306 unsigned long mask; 2307 2308 ret = -EFAULT; 2309 memset(buffer, 0, sizeof(buffer)); 2310 if (count > sizeof(buffer) - 1) 2311 count = sizeof(buffer) - 1; 2312 if (copy_from_user(buffer, buf, count)) 2313 goto out_no_task; 2314 2315 ret = -EINVAL; 2316 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2317 if (*end == '\n') 2318 end++; 2319 if (end - buffer == 0) 2320 goto out_no_task; 2321 2322 ret = -ESRCH; 2323 task = get_proc_task(file->f_dentry->d_inode); 2324 if (!task) 2325 goto out_no_task; 2326 2327 ret = end - buffer; 2328 mm = get_task_mm(task); 2329 if (!mm) 2330 goto out_no_mm; 2331 2332 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2333 if (val & mask) 2334 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2335 else 2336 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2337 } 2338 2339 mmput(mm); 2340 out_no_mm: 2341 put_task_struct(task); 2342 out_no_task: 2343 return ret; 2344 } 2345 2346 static const struct file_operations proc_coredump_filter_operations = { 2347 .read = proc_coredump_filter_read, 2348 .write = proc_coredump_filter_write, 2349 .llseek = generic_file_llseek, 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 static struct dentry *proc_base_instantiate(struct inode *dir, 2411 struct dentry *dentry, struct task_struct *task, const void *ptr) 2412 { 2413 const struct pid_entry *p = ptr; 2414 struct inode *inode; 2415 struct proc_inode *ei; 2416 struct dentry *error; 2417 2418 /* Allocate the inode */ 2419 error = ERR_PTR(-ENOMEM); 2420 inode = new_inode(dir->i_sb); 2421 if (!inode) 2422 goto out; 2423 2424 /* Initialize the inode */ 2425 ei = PROC_I(inode); 2426 inode->i_ino = get_next_ino(); 2427 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2428 2429 /* 2430 * grab the reference to the task. 2431 */ 2432 ei->pid = get_task_pid(task, PIDTYPE_PID); 2433 if (!ei->pid) 2434 goto out_iput; 2435 2436 inode->i_mode = p->mode; 2437 if (S_ISDIR(inode->i_mode)) 2438 set_nlink(inode, 2); 2439 if (S_ISLNK(inode->i_mode)) 2440 inode->i_size = 64; 2441 if (p->iop) 2442 inode->i_op = p->iop; 2443 if (p->fop) 2444 inode->i_fop = p->fop; 2445 ei->op = p->op; 2446 d_add(dentry, inode); 2447 error = NULL; 2448 out: 2449 return error; 2450 out_iput: 2451 iput(inode); 2452 goto out; 2453 } 2454 2455 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2456 { 2457 struct dentry *error; 2458 struct task_struct *task = get_proc_task(dir); 2459 const struct pid_entry *p, *last; 2460 2461 error = ERR_PTR(-ENOENT); 2462 2463 if (!task) 2464 goto out_no_task; 2465 2466 /* Lookup the directory entry */ 2467 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2468 for (p = proc_base_stuff; p <= last; p++) { 2469 if (p->len != dentry->d_name.len) 2470 continue; 2471 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2472 break; 2473 } 2474 if (p > last) 2475 goto out; 2476 2477 error = proc_base_instantiate(dir, dentry, task, p); 2478 2479 out: 2480 put_task_struct(task); 2481 out_no_task: 2482 return error; 2483 } 2484 2485 static int proc_base_fill_cache(struct file *filp, void *dirent, 2486 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2487 { 2488 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2489 proc_base_instantiate, task, p); 2490 } 2491 2492 #ifdef CONFIG_TASK_IO_ACCOUNTING 2493 static int do_io_accounting(struct task_struct *task, char *buffer, int whole) 2494 { 2495 struct task_io_accounting acct = task->ioac; 2496 unsigned long flags; 2497 int result; 2498 2499 result = mutex_lock_killable(&task->signal->cred_guard_mutex); 2500 if (result) 2501 return result; 2502 2503 if (!ptrace_may_access(task, PTRACE_MODE_READ)) { 2504 result = -EACCES; 2505 goto out_unlock; 2506 } 2507 2508 if (whole && lock_task_sighand(task, &flags)) { 2509 struct task_struct *t = task; 2510 2511 task_io_accounting_add(&acct, &task->signal->ioac); 2512 while_each_thread(task, t) 2513 task_io_accounting_add(&acct, &t->ioac); 2514 2515 unlock_task_sighand(task, &flags); 2516 } 2517 result = sprintf(buffer, 2518 "rchar: %llu\n" 2519 "wchar: %llu\n" 2520 "syscr: %llu\n" 2521 "syscw: %llu\n" 2522 "read_bytes: %llu\n" 2523 "write_bytes: %llu\n" 2524 "cancelled_write_bytes: %llu\n", 2525 (unsigned long long)acct.rchar, 2526 (unsigned long long)acct.wchar, 2527 (unsigned long long)acct.syscr, 2528 (unsigned long long)acct.syscw, 2529 (unsigned long long)acct.read_bytes, 2530 (unsigned long long)acct.write_bytes, 2531 (unsigned long long)acct.cancelled_write_bytes); 2532 out_unlock: 2533 mutex_unlock(&task->signal->cred_guard_mutex); 2534 return result; 2535 } 2536 2537 static int proc_tid_io_accounting(struct task_struct *task, char *buffer) 2538 { 2539 return do_io_accounting(task, buffer, 0); 2540 } 2541 2542 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer) 2543 { 2544 return do_io_accounting(task, buffer, 1); 2545 } 2546 #endif /* CONFIG_TASK_IO_ACCOUNTING */ 2547 2548 #ifdef CONFIG_USER_NS 2549 static int proc_id_map_open(struct inode *inode, struct file *file, 2550 struct seq_operations *seq_ops) 2551 { 2552 struct user_namespace *ns = NULL; 2553 struct task_struct *task; 2554 struct seq_file *seq; 2555 int ret = -EINVAL; 2556 2557 task = get_proc_task(inode); 2558 if (task) { 2559 rcu_read_lock(); 2560 ns = get_user_ns(task_cred_xxx(task, user_ns)); 2561 rcu_read_unlock(); 2562 put_task_struct(task); 2563 } 2564 if (!ns) 2565 goto err; 2566 2567 ret = seq_open(file, seq_ops); 2568 if (ret) 2569 goto err_put_ns; 2570 2571 seq = file->private_data; 2572 seq->private = ns; 2573 2574 return 0; 2575 err_put_ns: 2576 put_user_ns(ns); 2577 err: 2578 return ret; 2579 } 2580 2581 static int proc_id_map_release(struct inode *inode, struct file *file) 2582 { 2583 struct seq_file *seq = file->private_data; 2584 struct user_namespace *ns = seq->private; 2585 put_user_ns(ns); 2586 return seq_release(inode, file); 2587 } 2588 2589 static int proc_uid_map_open(struct inode *inode, struct file *file) 2590 { 2591 return proc_id_map_open(inode, file, &proc_uid_seq_operations); 2592 } 2593 2594 static int proc_gid_map_open(struct inode *inode, struct file *file) 2595 { 2596 return proc_id_map_open(inode, file, &proc_gid_seq_operations); 2597 } 2598 2599 static int proc_projid_map_open(struct inode *inode, struct file *file) 2600 { 2601 return proc_id_map_open(inode, file, &proc_projid_seq_operations); 2602 } 2603 2604 static const struct file_operations proc_uid_map_operations = { 2605 .open = proc_uid_map_open, 2606 .write = proc_uid_map_write, 2607 .read = seq_read, 2608 .llseek = seq_lseek, 2609 .release = proc_id_map_release, 2610 }; 2611 2612 static const struct file_operations proc_gid_map_operations = { 2613 .open = proc_gid_map_open, 2614 .write = proc_gid_map_write, 2615 .read = seq_read, 2616 .llseek = seq_lseek, 2617 .release = proc_id_map_release, 2618 }; 2619 2620 static const struct file_operations proc_projid_map_operations = { 2621 .open = proc_projid_map_open, 2622 .write = proc_projid_map_write, 2623 .read = seq_read, 2624 .llseek = seq_lseek, 2625 .release = proc_id_map_release, 2626 }; 2627 #endif /* CONFIG_USER_NS */ 2628 2629 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, 2630 struct pid *pid, struct task_struct *task) 2631 { 2632 int err = lock_trace(task); 2633 if (!err) { 2634 seq_printf(m, "%08x\n", task->personality); 2635 unlock_trace(task); 2636 } 2637 return err; 2638 } 2639 2640 /* 2641 * Thread groups 2642 */ 2643 static const struct file_operations proc_task_operations; 2644 static const struct inode_operations proc_task_inode_operations; 2645 2646 static const struct pid_entry tgid_base_stuff[] = { 2647 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations), 2648 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 2649 #ifdef CONFIG_CHECKPOINT_RESTORE 2650 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations), 2651 #endif 2652 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 2653 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 2654 #ifdef CONFIG_NET 2655 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations), 2656 #endif 2657 REG("environ", S_IRUSR, proc_environ_operations), 2658 INF("auxv", S_IRUSR, proc_pid_auxv), 2659 ONE("status", S_IRUGO, proc_pid_status), 2660 ONE("personality", S_IRUGO, proc_pid_personality), 2661 INF("limits", S_IRUGO, proc_pid_limits), 2662 #ifdef CONFIG_SCHED_DEBUG 2663 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 2664 #endif 2665 #ifdef CONFIG_SCHED_AUTOGROUP 2666 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), 2667 #endif 2668 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 2669 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 2670 INF("syscall", S_IRUGO, proc_pid_syscall), 2671 #endif 2672 INF("cmdline", S_IRUGO, proc_pid_cmdline), 2673 ONE("stat", S_IRUGO, proc_tgid_stat), 2674 ONE("statm", S_IRUGO, proc_pid_statm), 2675 REG("maps", S_IRUGO, proc_pid_maps_operations), 2676 #ifdef CONFIG_NUMA 2677 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), 2678 #endif 2679 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 2680 LNK("cwd", proc_cwd_link), 2681 LNK("root", proc_root_link), 2682 LNK("exe", proc_exe_link), 2683 REG("mounts", S_IRUGO, proc_mounts_operations), 2684 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 2685 REG("mountstats", S_IRUSR, proc_mountstats_operations), 2686 #ifdef CONFIG_PROC_PAGE_MONITOR 2687 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 2688 REG("smaps", S_IRUGO, proc_pid_smaps_operations), 2689 REG("pagemap", S_IRUGO, proc_pagemap_operations), 2690 #endif 2691 #ifdef CONFIG_SECURITY 2692 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 2693 #endif 2694 #ifdef CONFIG_KALLSYMS 2695 INF("wchan", S_IRUGO, proc_pid_wchan), 2696 #endif 2697 #ifdef CONFIG_STACKTRACE 2698 ONE("stack", S_IRUGO, proc_pid_stack), 2699 #endif 2700 #ifdef CONFIG_SCHEDSTATS 2701 INF("schedstat", S_IRUGO, proc_pid_schedstat), 2702 #endif 2703 #ifdef CONFIG_LATENCYTOP 2704 REG("latency", S_IRUGO, proc_lstats_operations), 2705 #endif 2706 #ifdef CONFIG_PROC_PID_CPUSET 2707 REG("cpuset", S_IRUGO, proc_cpuset_operations), 2708 #endif 2709 #ifdef CONFIG_CGROUPS 2710 REG("cgroup", S_IRUGO, proc_cgroup_operations), 2711 #endif 2712 INF("oom_score", S_IRUGO, proc_oom_score), 2713 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 2714 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 2715 #ifdef CONFIG_AUDITSYSCALL 2716 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 2717 REG("sessionid", S_IRUGO, proc_sessionid_operations), 2718 #endif 2719 #ifdef CONFIG_FAULT_INJECTION 2720 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 2721 #endif 2722 #ifdef CONFIG_ELF_CORE 2723 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), 2724 #endif 2725 #ifdef CONFIG_TASK_IO_ACCOUNTING 2726 INF("io", S_IRUSR, proc_tgid_io_accounting), 2727 #endif 2728 #ifdef CONFIG_HARDWALL 2729 INF("hardwall", S_IRUGO, proc_pid_hardwall), 2730 #endif 2731 #ifdef CONFIG_USER_NS 2732 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 2733 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 2734 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 2735 #endif 2736 }; 2737 2738 static int proc_tgid_base_readdir(struct file * filp, 2739 void * dirent, filldir_t filldir) 2740 { 2741 return proc_pident_readdir(filp,dirent,filldir, 2742 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2743 } 2744 2745 static const struct file_operations proc_tgid_base_operations = { 2746 .read = generic_read_dir, 2747 .readdir = proc_tgid_base_readdir, 2748 .llseek = default_llseek, 2749 }; 2750 2751 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 2752 { 2753 return proc_pident_lookup(dir, dentry, 2754 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2755 } 2756 2757 static const struct inode_operations proc_tgid_base_inode_operations = { 2758 .lookup = proc_tgid_base_lookup, 2759 .getattr = pid_getattr, 2760 .setattr = proc_setattr, 2761 .permission = proc_pid_permission, 2762 }; 2763 2764 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2765 { 2766 struct dentry *dentry, *leader, *dir; 2767 char buf[PROC_NUMBUF]; 2768 struct qstr name; 2769 2770 name.name = buf; 2771 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2772 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2773 if (dentry) { 2774 shrink_dcache_parent(dentry); 2775 d_drop(dentry); 2776 dput(dentry); 2777 } 2778 2779 name.name = buf; 2780 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2781 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2782 if (!leader) 2783 goto out; 2784 2785 name.name = "task"; 2786 name.len = strlen(name.name); 2787 dir = d_hash_and_lookup(leader, &name); 2788 if (!dir) 2789 goto out_put_leader; 2790 2791 name.name = buf; 2792 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2793 dentry = d_hash_and_lookup(dir, &name); 2794 if (dentry) { 2795 shrink_dcache_parent(dentry); 2796 d_drop(dentry); 2797 dput(dentry); 2798 } 2799 2800 dput(dir); 2801 out_put_leader: 2802 dput(leader); 2803 out: 2804 return; 2805 } 2806 2807 /** 2808 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2809 * @task: task that should be flushed. 2810 * 2811 * When flushing dentries from proc, one needs to flush them from global 2812 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2813 * in. This call is supposed to do all of this job. 2814 * 2815 * Looks in the dcache for 2816 * /proc/@pid 2817 * /proc/@tgid/task/@pid 2818 * if either directory is present flushes it and all of it'ts children 2819 * from the dcache. 2820 * 2821 * It is safe and reasonable to cache /proc entries for a task until 2822 * that task exits. After that they just clog up the dcache with 2823 * useless entries, possibly causing useful dcache entries to be 2824 * flushed instead. This routine is proved to flush those useless 2825 * dcache entries at process exit time. 2826 * 2827 * NOTE: This routine is just an optimization so it does not guarantee 2828 * that no dcache entries will exist at process exit time it 2829 * just makes it very unlikely that any will persist. 2830 */ 2831 2832 void proc_flush_task(struct task_struct *task) 2833 { 2834 int i; 2835 struct pid *pid, *tgid; 2836 struct upid *upid; 2837 2838 pid = task_pid(task); 2839 tgid = task_tgid(task); 2840 2841 for (i = 0; i <= pid->level; i++) { 2842 upid = &pid->numbers[i]; 2843 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 2844 tgid->numbers[i].nr); 2845 } 2846 2847 upid = &pid->numbers[pid->level]; 2848 if (upid->nr == 1) 2849 pid_ns_release_proc(upid->ns); 2850 } 2851 2852 static struct dentry *proc_pid_instantiate(struct inode *dir, 2853 struct dentry * dentry, 2854 struct task_struct *task, const void *ptr) 2855 { 2856 struct dentry *error = ERR_PTR(-ENOENT); 2857 struct inode *inode; 2858 2859 inode = proc_pid_make_inode(dir->i_sb, task); 2860 if (!inode) 2861 goto out; 2862 2863 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2864 inode->i_op = &proc_tgid_base_inode_operations; 2865 inode->i_fop = &proc_tgid_base_operations; 2866 inode->i_flags|=S_IMMUTABLE; 2867 2868 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff, 2869 ARRAY_SIZE(tgid_base_stuff))); 2870 2871 d_set_d_op(dentry, &pid_dentry_operations); 2872 2873 d_add(dentry, inode); 2874 /* Close the race of the process dying before we return the dentry */ 2875 if (pid_revalidate(dentry, 0)) 2876 error = NULL; 2877 out: 2878 return error; 2879 } 2880 2881 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 2882 { 2883 struct dentry *result; 2884 struct task_struct *task; 2885 unsigned tgid; 2886 struct pid_namespace *ns; 2887 2888 result = proc_base_lookup(dir, dentry); 2889 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 2890 goto out; 2891 2892 tgid = name_to_int(dentry); 2893 if (tgid == ~0U) 2894 goto out; 2895 2896 ns = dentry->d_sb->s_fs_info; 2897 rcu_read_lock(); 2898 task = find_task_by_pid_ns(tgid, ns); 2899 if (task) 2900 get_task_struct(task); 2901 rcu_read_unlock(); 2902 if (!task) 2903 goto out; 2904 2905 result = proc_pid_instantiate(dir, dentry, task, NULL); 2906 put_task_struct(task); 2907 out: 2908 return result; 2909 } 2910 2911 /* 2912 * Find the first task with tgid >= tgid 2913 * 2914 */ 2915 struct tgid_iter { 2916 unsigned int tgid; 2917 struct task_struct *task; 2918 }; 2919 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 2920 { 2921 struct pid *pid; 2922 2923 if (iter.task) 2924 put_task_struct(iter.task); 2925 rcu_read_lock(); 2926 retry: 2927 iter.task = NULL; 2928 pid = find_ge_pid(iter.tgid, ns); 2929 if (pid) { 2930 iter.tgid = pid_nr_ns(pid, ns); 2931 iter.task = pid_task(pid, PIDTYPE_PID); 2932 /* What we to know is if the pid we have find is the 2933 * pid of a thread_group_leader. Testing for task 2934 * being a thread_group_leader is the obvious thing 2935 * todo but there is a window when it fails, due to 2936 * the pid transfer logic in de_thread. 2937 * 2938 * So we perform the straight forward test of seeing 2939 * if the pid we have found is the pid of a thread 2940 * group leader, and don't worry if the task we have 2941 * found doesn't happen to be a thread group leader. 2942 * As we don't care in the case of readdir. 2943 */ 2944 if (!iter.task || !has_group_leader_pid(iter.task)) { 2945 iter.tgid += 1; 2946 goto retry; 2947 } 2948 get_task_struct(iter.task); 2949 } 2950 rcu_read_unlock(); 2951 return iter; 2952 } 2953 2954 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 2955 2956 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2957 struct tgid_iter iter) 2958 { 2959 char name[PROC_NUMBUF]; 2960 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 2961 return proc_fill_cache(filp, dirent, filldir, name, len, 2962 proc_pid_instantiate, iter.task, NULL); 2963 } 2964 2965 static int fake_filldir(void *buf, const char *name, int namelen, 2966 loff_t offset, u64 ino, unsigned d_type) 2967 { 2968 return 0; 2969 } 2970 2971 /* for the /proc/ directory itself, after non-process stuff has been done */ 2972 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 2973 { 2974 unsigned int nr; 2975 struct task_struct *reaper; 2976 struct tgid_iter iter; 2977 struct pid_namespace *ns; 2978 filldir_t __filldir; 2979 2980 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET) 2981 goto out_no_task; 2982 nr = filp->f_pos - FIRST_PROCESS_ENTRY; 2983 2984 reaper = get_proc_task(filp->f_path.dentry->d_inode); 2985 if (!reaper) 2986 goto out_no_task; 2987 2988 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 2989 const struct pid_entry *p = &proc_base_stuff[nr]; 2990 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 2991 goto out; 2992 } 2993 2994 ns = filp->f_dentry->d_sb->s_fs_info; 2995 iter.task = NULL; 2996 iter.tgid = filp->f_pos - TGID_OFFSET; 2997 for (iter = next_tgid(ns, iter); 2998 iter.task; 2999 iter.tgid += 1, iter = next_tgid(ns, iter)) { 3000 if (has_pid_permissions(ns, iter.task, 2)) 3001 __filldir = filldir; 3002 else 3003 __filldir = fake_filldir; 3004 3005 filp->f_pos = iter.tgid + TGID_OFFSET; 3006 if (proc_pid_fill_cache(filp, dirent, __filldir, iter) < 0) { 3007 put_task_struct(iter.task); 3008 goto out; 3009 } 3010 } 3011 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 3012 out: 3013 put_task_struct(reaper); 3014 out_no_task: 3015 return 0; 3016 } 3017 3018 /* 3019 * Tasks 3020 */ 3021 static const struct pid_entry tid_base_stuff[] = { 3022 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations), 3023 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations), 3024 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations), 3025 REG("environ", S_IRUSR, proc_environ_operations), 3026 INF("auxv", S_IRUSR, proc_pid_auxv), 3027 ONE("status", S_IRUGO, proc_pid_status), 3028 ONE("personality", S_IRUGO, proc_pid_personality), 3029 INF("limits", S_IRUGO, proc_pid_limits), 3030 #ifdef CONFIG_SCHED_DEBUG 3031 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations), 3032 #endif 3033 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), 3034 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 3035 INF("syscall", S_IRUGO, proc_pid_syscall), 3036 #endif 3037 INF("cmdline", S_IRUGO, proc_pid_cmdline), 3038 ONE("stat", S_IRUGO, proc_tid_stat), 3039 ONE("statm", S_IRUGO, proc_pid_statm), 3040 REG("maps", S_IRUGO, proc_tid_maps_operations), 3041 #ifdef CONFIG_CHECKPOINT_RESTORE 3042 REG("children", S_IRUGO, proc_tid_children_operations), 3043 #endif 3044 #ifdef CONFIG_NUMA 3045 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations), 3046 #endif 3047 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), 3048 LNK("cwd", proc_cwd_link), 3049 LNK("root", proc_root_link), 3050 LNK("exe", proc_exe_link), 3051 REG("mounts", S_IRUGO, proc_mounts_operations), 3052 REG("mountinfo", S_IRUGO, proc_mountinfo_operations), 3053 #ifdef CONFIG_PROC_PAGE_MONITOR 3054 REG("clear_refs", S_IWUSR, proc_clear_refs_operations), 3055 REG("smaps", S_IRUGO, proc_tid_smaps_operations), 3056 REG("pagemap", S_IRUGO, proc_pagemap_operations), 3057 #endif 3058 #ifdef CONFIG_SECURITY 3059 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations), 3060 #endif 3061 #ifdef CONFIG_KALLSYMS 3062 INF("wchan", S_IRUGO, proc_pid_wchan), 3063 #endif 3064 #ifdef CONFIG_STACKTRACE 3065 ONE("stack", S_IRUGO, proc_pid_stack), 3066 #endif 3067 #ifdef CONFIG_SCHEDSTATS 3068 INF("schedstat", S_IRUGO, proc_pid_schedstat), 3069 #endif 3070 #ifdef CONFIG_LATENCYTOP 3071 REG("latency", S_IRUGO, proc_lstats_operations), 3072 #endif 3073 #ifdef CONFIG_PROC_PID_CPUSET 3074 REG("cpuset", S_IRUGO, proc_cpuset_operations), 3075 #endif 3076 #ifdef CONFIG_CGROUPS 3077 REG("cgroup", S_IRUGO, proc_cgroup_operations), 3078 #endif 3079 INF("oom_score", S_IRUGO, proc_oom_score), 3080 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations), 3081 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations), 3082 #ifdef CONFIG_AUDITSYSCALL 3083 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), 3084 REG("sessionid", S_IRUGO, proc_sessionid_operations), 3085 #endif 3086 #ifdef CONFIG_FAULT_INJECTION 3087 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), 3088 #endif 3089 #ifdef CONFIG_TASK_IO_ACCOUNTING 3090 INF("io", S_IRUSR, proc_tid_io_accounting), 3091 #endif 3092 #ifdef CONFIG_HARDWALL 3093 INF("hardwall", S_IRUGO, proc_pid_hardwall), 3094 #endif 3095 #ifdef CONFIG_USER_NS 3096 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations), 3097 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), 3098 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), 3099 #endif 3100 }; 3101 3102 static int proc_tid_base_readdir(struct file * filp, 3103 void * dirent, filldir_t filldir) 3104 { 3105 return proc_pident_readdir(filp,dirent,filldir, 3106 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 3107 } 3108 3109 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 3110 { 3111 return proc_pident_lookup(dir, dentry, 3112 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 3113 } 3114 3115 static const struct file_operations proc_tid_base_operations = { 3116 .read = generic_read_dir, 3117 .readdir = proc_tid_base_readdir, 3118 .llseek = default_llseek, 3119 }; 3120 3121 static const struct inode_operations proc_tid_base_inode_operations = { 3122 .lookup = proc_tid_base_lookup, 3123 .getattr = pid_getattr, 3124 .setattr = proc_setattr, 3125 }; 3126 3127 static struct dentry *proc_task_instantiate(struct inode *dir, 3128 struct dentry *dentry, struct task_struct *task, const void *ptr) 3129 { 3130 struct dentry *error = ERR_PTR(-ENOENT); 3131 struct inode *inode; 3132 inode = proc_pid_make_inode(dir->i_sb, task); 3133 3134 if (!inode) 3135 goto out; 3136 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 3137 inode->i_op = &proc_tid_base_inode_operations; 3138 inode->i_fop = &proc_tid_base_operations; 3139 inode->i_flags|=S_IMMUTABLE; 3140 3141 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff, 3142 ARRAY_SIZE(tid_base_stuff))); 3143 3144 d_set_d_op(dentry, &pid_dentry_operations); 3145 3146 d_add(dentry, inode); 3147 /* Close the race of the process dying before we return the dentry */ 3148 if (pid_revalidate(dentry, 0)) 3149 error = NULL; 3150 out: 3151 return error; 3152 } 3153 3154 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) 3155 { 3156 struct dentry *result = ERR_PTR(-ENOENT); 3157 struct task_struct *task; 3158 struct task_struct *leader = get_proc_task(dir); 3159 unsigned tid; 3160 struct pid_namespace *ns; 3161 3162 if (!leader) 3163 goto out_no_task; 3164 3165 tid = name_to_int(dentry); 3166 if (tid == ~0U) 3167 goto out; 3168 3169 ns = dentry->d_sb->s_fs_info; 3170 rcu_read_lock(); 3171 task = find_task_by_pid_ns(tid, ns); 3172 if (task) 3173 get_task_struct(task); 3174 rcu_read_unlock(); 3175 if (!task) 3176 goto out; 3177 if (!same_thread_group(leader, task)) 3178 goto out_drop_task; 3179 3180 result = proc_task_instantiate(dir, dentry, task, NULL); 3181 out_drop_task: 3182 put_task_struct(task); 3183 out: 3184 put_task_struct(leader); 3185 out_no_task: 3186 return result; 3187 } 3188 3189 /* 3190 * Find the first tid of a thread group to return to user space. 3191 * 3192 * Usually this is just the thread group leader, but if the users 3193 * buffer was too small or there was a seek into the middle of the 3194 * directory we have more work todo. 3195 * 3196 * In the case of a short read we start with find_task_by_pid. 3197 * 3198 * In the case of a seek we start with the leader and walk nr 3199 * threads past it. 3200 */ 3201 static struct task_struct *first_tid(struct task_struct *leader, 3202 int tid, int nr, struct pid_namespace *ns) 3203 { 3204 struct task_struct *pos; 3205 3206 rcu_read_lock(); 3207 /* Attempt to start with the pid of a thread */ 3208 if (tid && (nr > 0)) { 3209 pos = find_task_by_pid_ns(tid, ns); 3210 if (pos && (pos->group_leader == leader)) 3211 goto found; 3212 } 3213 3214 /* If nr exceeds the number of threads there is nothing todo */ 3215 pos = NULL; 3216 if (nr && nr >= get_nr_threads(leader)) 3217 goto out; 3218 3219 /* If we haven't found our starting place yet start 3220 * with the leader and walk nr threads forward. 3221 */ 3222 for (pos = leader; nr > 0; --nr) { 3223 pos = next_thread(pos); 3224 if (pos == leader) { 3225 pos = NULL; 3226 goto out; 3227 } 3228 } 3229 found: 3230 get_task_struct(pos); 3231 out: 3232 rcu_read_unlock(); 3233 return pos; 3234 } 3235 3236 /* 3237 * Find the next thread in the thread list. 3238 * Return NULL if there is an error or no next thread. 3239 * 3240 * The reference to the input task_struct is released. 3241 */ 3242 static struct task_struct *next_tid(struct task_struct *start) 3243 { 3244 struct task_struct *pos = NULL; 3245 rcu_read_lock(); 3246 if (pid_alive(start)) { 3247 pos = next_thread(start); 3248 if (thread_group_leader(pos)) 3249 pos = NULL; 3250 else 3251 get_task_struct(pos); 3252 } 3253 rcu_read_unlock(); 3254 put_task_struct(start); 3255 return pos; 3256 } 3257 3258 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 3259 struct task_struct *task, int tid) 3260 { 3261 char name[PROC_NUMBUF]; 3262 int len = snprintf(name, sizeof(name), "%d", tid); 3263 return proc_fill_cache(filp, dirent, filldir, name, len, 3264 proc_task_instantiate, task, NULL); 3265 } 3266 3267 /* for the /proc/TGID/task/ directories */ 3268 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 3269 { 3270 struct dentry *dentry = filp->f_path.dentry; 3271 struct inode *inode = dentry->d_inode; 3272 struct task_struct *leader = NULL; 3273 struct task_struct *task; 3274 int retval = -ENOENT; 3275 ino_t ino; 3276 int tid; 3277 struct pid_namespace *ns; 3278 3279 task = get_proc_task(inode); 3280 if (!task) 3281 goto out_no_task; 3282 rcu_read_lock(); 3283 if (pid_alive(task)) { 3284 leader = task->group_leader; 3285 get_task_struct(leader); 3286 } 3287 rcu_read_unlock(); 3288 put_task_struct(task); 3289 if (!leader) 3290 goto out_no_task; 3291 retval = 0; 3292 3293 switch ((unsigned long)filp->f_pos) { 3294 case 0: 3295 ino = inode->i_ino; 3296 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0) 3297 goto out; 3298 filp->f_pos++; 3299 /* fall through */ 3300 case 1: 3301 ino = parent_ino(dentry); 3302 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0) 3303 goto out; 3304 filp->f_pos++; 3305 /* fall through */ 3306 } 3307 3308 /* f_version caches the tgid value that the last readdir call couldn't 3309 * return. lseek aka telldir automagically resets f_version to 0. 3310 */ 3311 ns = filp->f_dentry->d_sb->s_fs_info; 3312 tid = (int)filp->f_version; 3313 filp->f_version = 0; 3314 for (task = first_tid(leader, tid, filp->f_pos - 2, ns); 3315 task; 3316 task = next_tid(task), filp->f_pos++) { 3317 tid = task_pid_nr_ns(task, ns); 3318 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 3319 /* returning this tgid failed, save it as the first 3320 * pid for the next readir call */ 3321 filp->f_version = (u64)tid; 3322 put_task_struct(task); 3323 break; 3324 } 3325 } 3326 out: 3327 put_task_struct(leader); 3328 out_no_task: 3329 return retval; 3330 } 3331 3332 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 3333 { 3334 struct inode *inode = dentry->d_inode; 3335 struct task_struct *p = get_proc_task(inode); 3336 generic_fillattr(inode, stat); 3337 3338 if (p) { 3339 stat->nlink += get_nr_threads(p); 3340 put_task_struct(p); 3341 } 3342 3343 return 0; 3344 } 3345 3346 static const struct inode_operations proc_task_inode_operations = { 3347 .lookup = proc_task_lookup, 3348 .getattr = proc_task_getattr, 3349 .setattr = proc_setattr, 3350 .permission = proc_pid_permission, 3351 }; 3352 3353 static const struct file_operations proc_task_operations = { 3354 .read = generic_read_dir, 3355 .readdir = proc_task_readdir, 3356 .llseek = default_llseek, 3357 }; 3358