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