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