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/init.h> 57 #include <linux/capability.h> 58 #include <linux/file.h> 59 #include <linux/string.h> 60 #include <linux/seq_file.h> 61 #include <linux/namei.h> 62 #include <linux/mnt_namespace.h> 63 #include <linux/mm.h> 64 #include <linux/rcupdate.h> 65 #include <linux/kallsyms.h> 66 #include <linux/resource.h> 67 #include <linux/module.h> 68 #include <linux/mount.h> 69 #include <linux/security.h> 70 #include <linux/ptrace.h> 71 #include <linux/cgroup.h> 72 #include <linux/cpuset.h> 73 #include <linux/audit.h> 74 #include <linux/poll.h> 75 #include <linux/nsproxy.h> 76 #include <linux/oom.h> 77 #include <linux/elf.h> 78 #include <linux/pid_namespace.h> 79 #include "internal.h" 80 81 /* NOTE: 82 * Implementing inode permission operations in /proc is almost 83 * certainly an error. Permission checks need to happen during 84 * each system call not at open time. The reason is that most of 85 * what we wish to check for permissions in /proc varies at runtime. 86 * 87 * The classic example of a problem is opening file descriptors 88 * in /proc for a task before it execs a suid executable. 89 */ 90 91 92 /* Worst case buffer size needed for holding an integer. */ 93 #define PROC_NUMBUF 13 94 95 struct pid_entry { 96 char *name; 97 int len; 98 mode_t mode; 99 const struct inode_operations *iop; 100 const struct file_operations *fop; 101 union proc_op op; 102 }; 103 104 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 105 .name = (NAME), \ 106 .len = sizeof(NAME) - 1, \ 107 .mode = MODE, \ 108 .iop = IOP, \ 109 .fop = FOP, \ 110 .op = OP, \ 111 } 112 113 #define DIR(NAME, MODE, OTYPE) \ 114 NOD(NAME, (S_IFDIR|(MODE)), \ 115 &proc_##OTYPE##_inode_operations, &proc_##OTYPE##_operations, \ 116 {} ) 117 #define LNK(NAME, OTYPE) \ 118 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 119 &proc_pid_link_inode_operations, NULL, \ 120 { .proc_get_link = &proc_##OTYPE##_link } ) 121 #define REG(NAME, MODE, OTYPE) \ 122 NOD(NAME, (S_IFREG|(MODE)), NULL, \ 123 &proc_##OTYPE##_operations, {}) 124 #define INF(NAME, MODE, OTYPE) \ 125 NOD(NAME, (S_IFREG|(MODE)), \ 126 NULL, &proc_info_file_operations, \ 127 { .proc_read = &proc_##OTYPE } ) 128 129 int maps_protect; 130 EXPORT_SYMBOL(maps_protect); 131 132 static struct fs_struct *get_fs_struct(struct task_struct *task) 133 { 134 struct fs_struct *fs; 135 task_lock(task); 136 fs = task->fs; 137 if(fs) 138 atomic_inc(&fs->count); 139 task_unlock(task); 140 return fs; 141 } 142 143 static int get_nr_threads(struct task_struct *tsk) 144 { 145 /* Must be called with the rcu_read_lock held */ 146 unsigned long flags; 147 int count = 0; 148 149 if (lock_task_sighand(tsk, &flags)) { 150 count = atomic_read(&tsk->signal->count); 151 unlock_task_sighand(tsk, &flags); 152 } 153 return count; 154 } 155 156 static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt) 157 { 158 struct task_struct *task = get_proc_task(inode); 159 struct fs_struct *fs = NULL; 160 int result = -ENOENT; 161 162 if (task) { 163 fs = get_fs_struct(task); 164 put_task_struct(task); 165 } 166 if (fs) { 167 read_lock(&fs->lock); 168 *mnt = mntget(fs->pwdmnt); 169 *dentry = dget(fs->pwd); 170 read_unlock(&fs->lock); 171 result = 0; 172 put_fs_struct(fs); 173 } 174 return result; 175 } 176 177 static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt) 178 { 179 struct task_struct *task = get_proc_task(inode); 180 struct fs_struct *fs = NULL; 181 int result = -ENOENT; 182 183 if (task) { 184 fs = get_fs_struct(task); 185 put_task_struct(task); 186 } 187 if (fs) { 188 read_lock(&fs->lock); 189 *mnt = mntget(fs->rootmnt); 190 *dentry = dget(fs->root); 191 read_unlock(&fs->lock); 192 result = 0; 193 put_fs_struct(fs); 194 } 195 return result; 196 } 197 198 #define MAY_PTRACE(task) \ 199 (task == current || \ 200 (task->parent == current && \ 201 (task->ptrace & PT_PTRACED) && \ 202 (task->state == TASK_STOPPED || task->state == TASK_TRACED) && \ 203 security_ptrace(current,task) == 0)) 204 205 static int proc_pid_cmdline(struct task_struct *task, char * buffer) 206 { 207 int res = 0; 208 unsigned int len; 209 struct mm_struct *mm = get_task_mm(task); 210 if (!mm) 211 goto out; 212 if (!mm->arg_end) 213 goto out_mm; /* Shh! No looking before we're done */ 214 215 len = mm->arg_end - mm->arg_start; 216 217 if (len > PAGE_SIZE) 218 len = PAGE_SIZE; 219 220 res = access_process_vm(task, mm->arg_start, buffer, len, 0); 221 222 // If the nul at the end of args has been overwritten, then 223 // assume application is using setproctitle(3). 224 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) { 225 len = strnlen(buffer, res); 226 if (len < res) { 227 res = len; 228 } else { 229 len = mm->env_end - mm->env_start; 230 if (len > PAGE_SIZE - res) 231 len = PAGE_SIZE - res; 232 res += access_process_vm(task, mm->env_start, buffer+res, len, 0); 233 res = strnlen(buffer, res); 234 } 235 } 236 out_mm: 237 mmput(mm); 238 out: 239 return res; 240 } 241 242 static int proc_pid_auxv(struct task_struct *task, char *buffer) 243 { 244 int res = 0; 245 struct mm_struct *mm = get_task_mm(task); 246 if (mm) { 247 unsigned int nwords = 0; 248 do 249 nwords += 2; 250 while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 251 res = nwords * sizeof(mm->saved_auxv[0]); 252 if (res > PAGE_SIZE) 253 res = PAGE_SIZE; 254 memcpy(buffer, mm->saved_auxv, res); 255 mmput(mm); 256 } 257 return res; 258 } 259 260 261 #ifdef CONFIG_KALLSYMS 262 /* 263 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 264 * Returns the resolved symbol. If that fails, simply return the address. 265 */ 266 static int proc_pid_wchan(struct task_struct *task, char *buffer) 267 { 268 unsigned long wchan; 269 char symname[KSYM_NAME_LEN]; 270 271 wchan = get_wchan(task); 272 273 if (lookup_symbol_name(wchan, symname) < 0) 274 return sprintf(buffer, "%lu", wchan); 275 else 276 return sprintf(buffer, "%s", symname); 277 } 278 #endif /* CONFIG_KALLSYMS */ 279 280 #ifdef CONFIG_SCHEDSTATS 281 /* 282 * Provides /proc/PID/schedstat 283 */ 284 static int proc_pid_schedstat(struct task_struct *task, char *buffer) 285 { 286 return sprintf(buffer, "%llu %llu %lu\n", 287 task->sched_info.cpu_time, 288 task->sched_info.run_delay, 289 task->sched_info.pcount); 290 } 291 #endif 292 293 /* The badness from the OOM killer */ 294 unsigned long badness(struct task_struct *p, unsigned long uptime); 295 static int proc_oom_score(struct task_struct *task, char *buffer) 296 { 297 unsigned long points; 298 struct timespec uptime; 299 300 do_posix_clock_monotonic_gettime(&uptime); 301 read_lock(&tasklist_lock); 302 points = badness(task, uptime.tv_sec); 303 read_unlock(&tasklist_lock); 304 return sprintf(buffer, "%lu\n", points); 305 } 306 307 struct limit_names { 308 char *name; 309 char *unit; 310 }; 311 312 static const struct limit_names lnames[RLIM_NLIMITS] = { 313 [RLIMIT_CPU] = {"Max cpu time", "ms"}, 314 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 315 [RLIMIT_DATA] = {"Max data size", "bytes"}, 316 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 317 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 318 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 319 [RLIMIT_NPROC] = {"Max processes", "processes"}, 320 [RLIMIT_NOFILE] = {"Max open files", "files"}, 321 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 322 [RLIMIT_AS] = {"Max address space", "bytes"}, 323 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 324 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 325 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 326 [RLIMIT_NICE] = {"Max nice priority", NULL}, 327 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 328 }; 329 330 /* Display limits for a process */ 331 static int proc_pid_limits(struct task_struct *task, char *buffer) 332 { 333 unsigned int i; 334 int count = 0; 335 unsigned long flags; 336 char *bufptr = buffer; 337 338 struct rlimit rlim[RLIM_NLIMITS]; 339 340 rcu_read_lock(); 341 if (!lock_task_sighand(task,&flags)) { 342 rcu_read_unlock(); 343 return 0; 344 } 345 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 346 unlock_task_sighand(task, &flags); 347 rcu_read_unlock(); 348 349 /* 350 * print the file header 351 */ 352 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n", 353 "Limit", "Soft Limit", "Hard Limit", "Units"); 354 355 for (i = 0; i < RLIM_NLIMITS; i++) { 356 if (rlim[i].rlim_cur == RLIM_INFINITY) 357 count += sprintf(&bufptr[count], "%-25s %-20s ", 358 lnames[i].name, "unlimited"); 359 else 360 count += sprintf(&bufptr[count], "%-25s %-20lu ", 361 lnames[i].name, rlim[i].rlim_cur); 362 363 if (rlim[i].rlim_max == RLIM_INFINITY) 364 count += sprintf(&bufptr[count], "%-20s ", "unlimited"); 365 else 366 count += sprintf(&bufptr[count], "%-20lu ", 367 rlim[i].rlim_max); 368 369 if (lnames[i].unit) 370 count += sprintf(&bufptr[count], "%-10s\n", 371 lnames[i].unit); 372 else 373 count += sprintf(&bufptr[count], "\n"); 374 } 375 376 return count; 377 } 378 379 /************************************************************************/ 380 /* Here the fs part begins */ 381 /************************************************************************/ 382 383 /* permission checks */ 384 static int proc_fd_access_allowed(struct inode *inode) 385 { 386 struct task_struct *task; 387 int allowed = 0; 388 /* Allow access to a task's file descriptors if it is us or we 389 * may use ptrace attach to the process and find out that 390 * information. 391 */ 392 task = get_proc_task(inode); 393 if (task) { 394 allowed = ptrace_may_attach(task); 395 put_task_struct(task); 396 } 397 return allowed; 398 } 399 400 static int proc_setattr(struct dentry *dentry, struct iattr *attr) 401 { 402 int error; 403 struct inode *inode = dentry->d_inode; 404 405 if (attr->ia_valid & ATTR_MODE) 406 return -EPERM; 407 408 error = inode_change_ok(inode, attr); 409 if (!error) 410 error = inode_setattr(inode, attr); 411 return error; 412 } 413 414 static const struct inode_operations proc_def_inode_operations = { 415 .setattr = proc_setattr, 416 }; 417 418 extern struct seq_operations mounts_op; 419 struct proc_mounts { 420 struct seq_file m; 421 int event; 422 }; 423 424 static int mounts_open(struct inode *inode, struct file *file) 425 { 426 struct task_struct *task = get_proc_task(inode); 427 struct nsproxy *nsp; 428 struct mnt_namespace *ns = NULL; 429 struct proc_mounts *p; 430 int ret = -EINVAL; 431 432 if (task) { 433 rcu_read_lock(); 434 nsp = task_nsproxy(task); 435 if (nsp) { 436 ns = nsp->mnt_ns; 437 if (ns) 438 get_mnt_ns(ns); 439 } 440 rcu_read_unlock(); 441 442 put_task_struct(task); 443 } 444 445 if (ns) { 446 ret = -ENOMEM; 447 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL); 448 if (p) { 449 file->private_data = &p->m; 450 ret = seq_open(file, &mounts_op); 451 if (!ret) { 452 p->m.private = ns; 453 p->event = ns->event; 454 return 0; 455 } 456 kfree(p); 457 } 458 put_mnt_ns(ns); 459 } 460 return ret; 461 } 462 463 static int mounts_release(struct inode *inode, struct file *file) 464 { 465 struct seq_file *m = file->private_data; 466 struct mnt_namespace *ns = m->private; 467 put_mnt_ns(ns); 468 return seq_release(inode, file); 469 } 470 471 static unsigned mounts_poll(struct file *file, poll_table *wait) 472 { 473 struct proc_mounts *p = file->private_data; 474 struct mnt_namespace *ns = p->m.private; 475 unsigned res = 0; 476 477 poll_wait(file, &ns->poll, wait); 478 479 spin_lock(&vfsmount_lock); 480 if (p->event != ns->event) { 481 p->event = ns->event; 482 res = POLLERR; 483 } 484 spin_unlock(&vfsmount_lock); 485 486 return res; 487 } 488 489 static const struct file_operations proc_mounts_operations = { 490 .open = mounts_open, 491 .read = seq_read, 492 .llseek = seq_lseek, 493 .release = mounts_release, 494 .poll = mounts_poll, 495 }; 496 497 extern struct seq_operations mountstats_op; 498 static int mountstats_open(struct inode *inode, struct file *file) 499 { 500 int ret = seq_open(file, &mountstats_op); 501 502 if (!ret) { 503 struct seq_file *m = file->private_data; 504 struct nsproxy *nsp; 505 struct mnt_namespace *mnt_ns = NULL; 506 struct task_struct *task = get_proc_task(inode); 507 508 if (task) { 509 rcu_read_lock(); 510 nsp = task_nsproxy(task); 511 if (nsp) { 512 mnt_ns = nsp->mnt_ns; 513 if (mnt_ns) 514 get_mnt_ns(mnt_ns); 515 } 516 rcu_read_unlock(); 517 518 put_task_struct(task); 519 } 520 521 if (mnt_ns) 522 m->private = mnt_ns; 523 else { 524 seq_release(inode, file); 525 ret = -EINVAL; 526 } 527 } 528 return ret; 529 } 530 531 static const struct file_operations proc_mountstats_operations = { 532 .open = mountstats_open, 533 .read = seq_read, 534 .llseek = seq_lseek, 535 .release = mounts_release, 536 }; 537 538 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */ 539 540 static ssize_t proc_info_read(struct file * file, char __user * buf, 541 size_t count, loff_t *ppos) 542 { 543 struct inode * inode = file->f_path.dentry->d_inode; 544 unsigned long page; 545 ssize_t length; 546 struct task_struct *task = get_proc_task(inode); 547 548 length = -ESRCH; 549 if (!task) 550 goto out_no_task; 551 552 if (count > PROC_BLOCK_SIZE) 553 count = PROC_BLOCK_SIZE; 554 555 length = -ENOMEM; 556 if (!(page = __get_free_page(GFP_TEMPORARY))) 557 goto out; 558 559 length = PROC_I(inode)->op.proc_read(task, (char*)page); 560 561 if (length >= 0) 562 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length); 563 free_page(page); 564 out: 565 put_task_struct(task); 566 out_no_task: 567 return length; 568 } 569 570 static const struct file_operations proc_info_file_operations = { 571 .read = proc_info_read, 572 }; 573 574 static int mem_open(struct inode* inode, struct file* file) 575 { 576 file->private_data = (void*)((long)current->self_exec_id); 577 return 0; 578 } 579 580 static ssize_t mem_read(struct file * file, char __user * buf, 581 size_t count, loff_t *ppos) 582 { 583 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 584 char *page; 585 unsigned long src = *ppos; 586 int ret = -ESRCH; 587 struct mm_struct *mm; 588 589 if (!task) 590 goto out_no_task; 591 592 if (!MAY_PTRACE(task) || !ptrace_may_attach(task)) 593 goto out; 594 595 ret = -ENOMEM; 596 page = (char *)__get_free_page(GFP_TEMPORARY); 597 if (!page) 598 goto out; 599 600 ret = 0; 601 602 mm = get_task_mm(task); 603 if (!mm) 604 goto out_free; 605 606 ret = -EIO; 607 608 if (file->private_data != (void*)((long)current->self_exec_id)) 609 goto out_put; 610 611 ret = 0; 612 613 while (count > 0) { 614 int this_len, retval; 615 616 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 617 retval = access_process_vm(task, src, page, this_len, 0); 618 if (!retval || !MAY_PTRACE(task) || !ptrace_may_attach(task)) { 619 if (!ret) 620 ret = -EIO; 621 break; 622 } 623 624 if (copy_to_user(buf, page, retval)) { 625 ret = -EFAULT; 626 break; 627 } 628 629 ret += retval; 630 src += retval; 631 buf += retval; 632 count -= retval; 633 } 634 *ppos = src; 635 636 out_put: 637 mmput(mm); 638 out_free: 639 free_page((unsigned long) page); 640 out: 641 put_task_struct(task); 642 out_no_task: 643 return ret; 644 } 645 646 #define mem_write NULL 647 648 #ifndef mem_write 649 /* This is a security hazard */ 650 static ssize_t mem_write(struct file * file, const char __user *buf, 651 size_t count, loff_t *ppos) 652 { 653 int copied; 654 char *page; 655 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 656 unsigned long dst = *ppos; 657 658 copied = -ESRCH; 659 if (!task) 660 goto out_no_task; 661 662 if (!MAY_PTRACE(task) || !ptrace_may_attach(task)) 663 goto out; 664 665 copied = -ENOMEM; 666 page = (char *)__get_free_page(GFP_TEMPORARY); 667 if (!page) 668 goto out; 669 670 copied = 0; 671 while (count > 0) { 672 int this_len, retval; 673 674 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 675 if (copy_from_user(page, buf, this_len)) { 676 copied = -EFAULT; 677 break; 678 } 679 retval = access_process_vm(task, dst, page, this_len, 1); 680 if (!retval) { 681 if (!copied) 682 copied = -EIO; 683 break; 684 } 685 copied += retval; 686 buf += retval; 687 dst += retval; 688 count -= retval; 689 } 690 *ppos = dst; 691 free_page((unsigned long) page); 692 out: 693 put_task_struct(task); 694 out_no_task: 695 return copied; 696 } 697 #endif 698 699 static loff_t mem_lseek(struct file * file, loff_t offset, int orig) 700 { 701 switch (orig) { 702 case 0: 703 file->f_pos = offset; 704 break; 705 case 1: 706 file->f_pos += offset; 707 break; 708 default: 709 return -EINVAL; 710 } 711 force_successful_syscall_return(); 712 return file->f_pos; 713 } 714 715 static const struct file_operations proc_mem_operations = { 716 .llseek = mem_lseek, 717 .read = mem_read, 718 .write = mem_write, 719 .open = mem_open, 720 }; 721 722 static ssize_t environ_read(struct file *file, char __user *buf, 723 size_t count, loff_t *ppos) 724 { 725 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 726 char *page; 727 unsigned long src = *ppos; 728 int ret = -ESRCH; 729 struct mm_struct *mm; 730 731 if (!task) 732 goto out_no_task; 733 734 if (!ptrace_may_attach(task)) 735 goto out; 736 737 ret = -ENOMEM; 738 page = (char *)__get_free_page(GFP_TEMPORARY); 739 if (!page) 740 goto out; 741 742 ret = 0; 743 744 mm = get_task_mm(task); 745 if (!mm) 746 goto out_free; 747 748 while (count > 0) { 749 int this_len, retval, max_len; 750 751 this_len = mm->env_end - (mm->env_start + src); 752 753 if (this_len <= 0) 754 break; 755 756 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 757 this_len = (this_len > max_len) ? max_len : this_len; 758 759 retval = access_process_vm(task, (mm->env_start + src), 760 page, this_len, 0); 761 762 if (retval <= 0) { 763 ret = retval; 764 break; 765 } 766 767 if (copy_to_user(buf, page, retval)) { 768 ret = -EFAULT; 769 break; 770 } 771 772 ret += retval; 773 src += retval; 774 buf += retval; 775 count -= retval; 776 } 777 *ppos = src; 778 779 mmput(mm); 780 out_free: 781 free_page((unsigned long) page); 782 out: 783 put_task_struct(task); 784 out_no_task: 785 return ret; 786 } 787 788 static const struct file_operations proc_environ_operations = { 789 .read = environ_read, 790 }; 791 792 static ssize_t oom_adjust_read(struct file *file, char __user *buf, 793 size_t count, loff_t *ppos) 794 { 795 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 796 char buffer[PROC_NUMBUF]; 797 size_t len; 798 int oom_adjust; 799 800 if (!task) 801 return -ESRCH; 802 oom_adjust = task->oomkilladj; 803 put_task_struct(task); 804 805 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); 806 807 return simple_read_from_buffer(buf, count, ppos, buffer, len); 808 } 809 810 static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 811 size_t count, loff_t *ppos) 812 { 813 struct task_struct *task; 814 char buffer[PROC_NUMBUF], *end; 815 int oom_adjust; 816 817 memset(buffer, 0, sizeof(buffer)); 818 if (count > sizeof(buffer) - 1) 819 count = sizeof(buffer) - 1; 820 if (copy_from_user(buffer, buf, count)) 821 return -EFAULT; 822 oom_adjust = simple_strtol(buffer, &end, 0); 823 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && 824 oom_adjust != OOM_DISABLE) 825 return -EINVAL; 826 if (*end == '\n') 827 end++; 828 task = get_proc_task(file->f_path.dentry->d_inode); 829 if (!task) 830 return -ESRCH; 831 if (oom_adjust < task->oomkilladj && !capable(CAP_SYS_RESOURCE)) { 832 put_task_struct(task); 833 return -EACCES; 834 } 835 task->oomkilladj = oom_adjust; 836 put_task_struct(task); 837 if (end - buffer == 0) 838 return -EIO; 839 return end - buffer; 840 } 841 842 static const struct file_operations proc_oom_adjust_operations = { 843 .read = oom_adjust_read, 844 .write = oom_adjust_write, 845 }; 846 847 #ifdef CONFIG_MMU 848 static ssize_t clear_refs_write(struct file *file, const char __user *buf, 849 size_t count, loff_t *ppos) 850 { 851 struct task_struct *task; 852 char buffer[PROC_NUMBUF], *end; 853 struct mm_struct *mm; 854 855 memset(buffer, 0, sizeof(buffer)); 856 if (count > sizeof(buffer) - 1) 857 count = sizeof(buffer) - 1; 858 if (copy_from_user(buffer, buf, count)) 859 return -EFAULT; 860 if (!simple_strtol(buffer, &end, 0)) 861 return -EINVAL; 862 if (*end == '\n') 863 end++; 864 task = get_proc_task(file->f_path.dentry->d_inode); 865 if (!task) 866 return -ESRCH; 867 mm = get_task_mm(task); 868 if (mm) { 869 clear_refs_smap(mm); 870 mmput(mm); 871 } 872 put_task_struct(task); 873 if (end - buffer == 0) 874 return -EIO; 875 return end - buffer; 876 } 877 878 static struct file_operations proc_clear_refs_operations = { 879 .write = clear_refs_write, 880 }; 881 #endif 882 883 #ifdef CONFIG_AUDITSYSCALL 884 #define TMPBUFLEN 21 885 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 886 size_t count, loff_t *ppos) 887 { 888 struct inode * inode = file->f_path.dentry->d_inode; 889 struct task_struct *task = get_proc_task(inode); 890 ssize_t length; 891 char tmpbuf[TMPBUFLEN]; 892 893 if (!task) 894 return -ESRCH; 895 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 896 audit_get_loginuid(task->audit_context)); 897 put_task_struct(task); 898 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 899 } 900 901 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 902 size_t count, loff_t *ppos) 903 { 904 struct inode * inode = file->f_path.dentry->d_inode; 905 char *page, *tmp; 906 ssize_t length; 907 uid_t loginuid; 908 909 if (!capable(CAP_AUDIT_CONTROL)) 910 return -EPERM; 911 912 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) 913 return -EPERM; 914 915 if (count >= PAGE_SIZE) 916 count = PAGE_SIZE - 1; 917 918 if (*ppos != 0) { 919 /* No partial writes. */ 920 return -EINVAL; 921 } 922 page = (char*)__get_free_page(GFP_TEMPORARY); 923 if (!page) 924 return -ENOMEM; 925 length = -EFAULT; 926 if (copy_from_user(page, buf, count)) 927 goto out_free_page; 928 929 page[count] = '\0'; 930 loginuid = simple_strtoul(page, &tmp, 10); 931 if (tmp == page) { 932 length = -EINVAL; 933 goto out_free_page; 934 935 } 936 length = audit_set_loginuid(current, loginuid); 937 if (likely(length == 0)) 938 length = count; 939 940 out_free_page: 941 free_page((unsigned long) page); 942 return length; 943 } 944 945 static const struct file_operations proc_loginuid_operations = { 946 .read = proc_loginuid_read, 947 .write = proc_loginuid_write, 948 }; 949 #endif 950 951 #ifdef CONFIG_FAULT_INJECTION 952 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 953 size_t count, loff_t *ppos) 954 { 955 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 956 char buffer[PROC_NUMBUF]; 957 size_t len; 958 int make_it_fail; 959 960 if (!task) 961 return -ESRCH; 962 make_it_fail = task->make_it_fail; 963 put_task_struct(task); 964 965 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 966 967 return simple_read_from_buffer(buf, count, ppos, buffer, len); 968 } 969 970 static ssize_t proc_fault_inject_write(struct file * file, 971 const char __user * buf, size_t count, loff_t *ppos) 972 { 973 struct task_struct *task; 974 char buffer[PROC_NUMBUF], *end; 975 int make_it_fail; 976 977 if (!capable(CAP_SYS_RESOURCE)) 978 return -EPERM; 979 memset(buffer, 0, sizeof(buffer)); 980 if (count > sizeof(buffer) - 1) 981 count = sizeof(buffer) - 1; 982 if (copy_from_user(buffer, buf, count)) 983 return -EFAULT; 984 make_it_fail = simple_strtol(buffer, &end, 0); 985 if (*end == '\n') 986 end++; 987 task = get_proc_task(file->f_dentry->d_inode); 988 if (!task) 989 return -ESRCH; 990 task->make_it_fail = make_it_fail; 991 put_task_struct(task); 992 if (end - buffer == 0) 993 return -EIO; 994 return end - buffer; 995 } 996 997 static const struct file_operations proc_fault_inject_operations = { 998 .read = proc_fault_inject_read, 999 .write = proc_fault_inject_write, 1000 }; 1001 #endif 1002 1003 #ifdef CONFIG_SCHED_DEBUG 1004 /* 1005 * Print out various scheduling related per-task fields: 1006 */ 1007 static int sched_show(struct seq_file *m, void *v) 1008 { 1009 struct inode *inode = m->private; 1010 struct task_struct *p; 1011 1012 WARN_ON(!inode); 1013 1014 p = get_proc_task(inode); 1015 if (!p) 1016 return -ESRCH; 1017 proc_sched_show_task(p, m); 1018 1019 put_task_struct(p); 1020 1021 return 0; 1022 } 1023 1024 static ssize_t 1025 sched_write(struct file *file, const char __user *buf, 1026 size_t count, loff_t *offset) 1027 { 1028 struct inode *inode = file->f_path.dentry->d_inode; 1029 struct task_struct *p; 1030 1031 WARN_ON(!inode); 1032 1033 p = get_proc_task(inode); 1034 if (!p) 1035 return -ESRCH; 1036 proc_sched_set_task(p); 1037 1038 put_task_struct(p); 1039 1040 return count; 1041 } 1042 1043 static int sched_open(struct inode *inode, struct file *filp) 1044 { 1045 int ret; 1046 1047 ret = single_open(filp, sched_show, NULL); 1048 if (!ret) { 1049 struct seq_file *m = filp->private_data; 1050 1051 m->private = inode; 1052 } 1053 return ret; 1054 } 1055 1056 static const struct file_operations proc_pid_sched_operations = { 1057 .open = sched_open, 1058 .read = seq_read, 1059 .write = sched_write, 1060 .llseek = seq_lseek, 1061 .release = single_release, 1062 }; 1063 1064 #endif 1065 1066 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1067 { 1068 struct inode *inode = dentry->d_inode; 1069 int error = -EACCES; 1070 1071 /* We don't need a base pointer in the /proc filesystem */ 1072 path_release(nd); 1073 1074 /* Are we allowed to snoop on the tasks file descriptors? */ 1075 if (!proc_fd_access_allowed(inode)) 1076 goto out; 1077 1078 error = PROC_I(inode)->op.proc_get_link(inode, &nd->dentry, &nd->mnt); 1079 nd->last_type = LAST_BIND; 1080 out: 1081 return ERR_PTR(error); 1082 } 1083 1084 static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt, 1085 char __user *buffer, int buflen) 1086 { 1087 struct inode * inode; 1088 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1089 char *path; 1090 int len; 1091 1092 if (!tmp) 1093 return -ENOMEM; 1094 1095 inode = dentry->d_inode; 1096 path = d_path(dentry, mnt, tmp, PAGE_SIZE); 1097 len = PTR_ERR(path); 1098 if (IS_ERR(path)) 1099 goto out; 1100 len = tmp + PAGE_SIZE - 1 - path; 1101 1102 if (len > buflen) 1103 len = buflen; 1104 if (copy_to_user(buffer, path, len)) 1105 len = -EFAULT; 1106 out: 1107 free_page((unsigned long)tmp); 1108 return len; 1109 } 1110 1111 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1112 { 1113 int error = -EACCES; 1114 struct inode *inode = dentry->d_inode; 1115 struct dentry *de; 1116 struct vfsmount *mnt = NULL; 1117 1118 /* Are we allowed to snoop on the tasks file descriptors? */ 1119 if (!proc_fd_access_allowed(inode)) 1120 goto out; 1121 1122 error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt); 1123 if (error) 1124 goto out; 1125 1126 error = do_proc_readlink(de, mnt, buffer, buflen); 1127 dput(de); 1128 mntput(mnt); 1129 out: 1130 return error; 1131 } 1132 1133 static const struct inode_operations proc_pid_link_inode_operations = { 1134 .readlink = proc_pid_readlink, 1135 .follow_link = proc_pid_follow_link, 1136 .setattr = proc_setattr, 1137 }; 1138 1139 1140 /* building an inode */ 1141 1142 static int task_dumpable(struct task_struct *task) 1143 { 1144 int dumpable = 0; 1145 struct mm_struct *mm; 1146 1147 task_lock(task); 1148 mm = task->mm; 1149 if (mm) 1150 dumpable = get_dumpable(mm); 1151 task_unlock(task); 1152 if(dumpable == 1) 1153 return 1; 1154 return 0; 1155 } 1156 1157 1158 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1159 { 1160 struct inode * inode; 1161 struct proc_inode *ei; 1162 1163 /* We need a new inode */ 1164 1165 inode = new_inode(sb); 1166 if (!inode) 1167 goto out; 1168 1169 /* Common stuff */ 1170 ei = PROC_I(inode); 1171 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1172 inode->i_op = &proc_def_inode_operations; 1173 1174 /* 1175 * grab the reference to task. 1176 */ 1177 ei->pid = get_task_pid(task, PIDTYPE_PID); 1178 if (!ei->pid) 1179 goto out_unlock; 1180 1181 inode->i_uid = 0; 1182 inode->i_gid = 0; 1183 if (task_dumpable(task)) { 1184 inode->i_uid = task->euid; 1185 inode->i_gid = task->egid; 1186 } 1187 security_task_to_inode(task, inode); 1188 1189 out: 1190 return inode; 1191 1192 out_unlock: 1193 iput(inode); 1194 return NULL; 1195 } 1196 1197 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1198 { 1199 struct inode *inode = dentry->d_inode; 1200 struct task_struct *task; 1201 generic_fillattr(inode, stat); 1202 1203 rcu_read_lock(); 1204 stat->uid = 0; 1205 stat->gid = 0; 1206 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1207 if (task) { 1208 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1209 task_dumpable(task)) { 1210 stat->uid = task->euid; 1211 stat->gid = task->egid; 1212 } 1213 } 1214 rcu_read_unlock(); 1215 return 0; 1216 } 1217 1218 /* dentry stuff */ 1219 1220 /* 1221 * Exceptional case: normally we are not allowed to unhash a busy 1222 * directory. In this case, however, we can do it - no aliasing problems 1223 * due to the way we treat inodes. 1224 * 1225 * Rewrite the inode's ownerships here because the owning task may have 1226 * performed a setuid(), etc. 1227 * 1228 * Before the /proc/pid/status file was created the only way to read 1229 * the effective uid of a /process was to stat /proc/pid. Reading 1230 * /proc/pid/status is slow enough that procps and other packages 1231 * kept stating /proc/pid. To keep the rules in /proc simple I have 1232 * made this apply to all per process world readable and executable 1233 * directories. 1234 */ 1235 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1236 { 1237 struct inode *inode = dentry->d_inode; 1238 struct task_struct *task = get_proc_task(inode); 1239 if (task) { 1240 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1241 task_dumpable(task)) { 1242 inode->i_uid = task->euid; 1243 inode->i_gid = task->egid; 1244 } else { 1245 inode->i_uid = 0; 1246 inode->i_gid = 0; 1247 } 1248 inode->i_mode &= ~(S_ISUID | S_ISGID); 1249 security_task_to_inode(task, inode); 1250 put_task_struct(task); 1251 return 1; 1252 } 1253 d_drop(dentry); 1254 return 0; 1255 } 1256 1257 static int pid_delete_dentry(struct dentry * dentry) 1258 { 1259 /* Is the task we represent dead? 1260 * If so, then don't put the dentry on the lru list, 1261 * kill it immediately. 1262 */ 1263 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1264 } 1265 1266 static struct dentry_operations pid_dentry_operations = 1267 { 1268 .d_revalidate = pid_revalidate, 1269 .d_delete = pid_delete_dentry, 1270 }; 1271 1272 /* Lookups */ 1273 1274 typedef struct dentry *instantiate_t(struct inode *, struct dentry *, 1275 struct task_struct *, const void *); 1276 1277 /* 1278 * Fill a directory entry. 1279 * 1280 * If possible create the dcache entry and derive our inode number and 1281 * file type from dcache entry. 1282 * 1283 * Since all of the proc inode numbers are dynamically generated, the inode 1284 * numbers do not exist until the inode is cache. This means creating the 1285 * the dcache entry in readdir is necessary to keep the inode numbers 1286 * reported by readdir in sync with the inode numbers reported 1287 * by stat. 1288 */ 1289 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1290 char *name, int len, 1291 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1292 { 1293 struct dentry *child, *dir = filp->f_path.dentry; 1294 struct inode *inode; 1295 struct qstr qname; 1296 ino_t ino = 0; 1297 unsigned type = DT_UNKNOWN; 1298 1299 qname.name = name; 1300 qname.len = len; 1301 qname.hash = full_name_hash(name, len); 1302 1303 child = d_lookup(dir, &qname); 1304 if (!child) { 1305 struct dentry *new; 1306 new = d_alloc(dir, &qname); 1307 if (new) { 1308 child = instantiate(dir->d_inode, new, task, ptr); 1309 if (child) 1310 dput(new); 1311 else 1312 child = new; 1313 } 1314 } 1315 if (!child || IS_ERR(child) || !child->d_inode) 1316 goto end_instantiate; 1317 inode = child->d_inode; 1318 if (inode) { 1319 ino = inode->i_ino; 1320 type = inode->i_mode >> 12; 1321 } 1322 dput(child); 1323 end_instantiate: 1324 if (!ino) 1325 ino = find_inode_number(dir, &qname); 1326 if (!ino) 1327 ino = 1; 1328 return filldir(dirent, name, len, filp->f_pos, ino, type); 1329 } 1330 1331 static unsigned name_to_int(struct dentry *dentry) 1332 { 1333 const char *name = dentry->d_name.name; 1334 int len = dentry->d_name.len; 1335 unsigned n = 0; 1336 1337 if (len > 1 && *name == '0') 1338 goto out; 1339 while (len-- > 0) { 1340 unsigned c = *name++ - '0'; 1341 if (c > 9) 1342 goto out; 1343 if (n >= (~0U-9)/10) 1344 goto out; 1345 n *= 10; 1346 n += c; 1347 } 1348 return n; 1349 out: 1350 return ~0U; 1351 } 1352 1353 #define PROC_FDINFO_MAX 64 1354 1355 static int proc_fd_info(struct inode *inode, struct dentry **dentry, 1356 struct vfsmount **mnt, char *info) 1357 { 1358 struct task_struct *task = get_proc_task(inode); 1359 struct files_struct *files = NULL; 1360 struct file *file; 1361 int fd = proc_fd(inode); 1362 1363 if (task) { 1364 files = get_files_struct(task); 1365 put_task_struct(task); 1366 } 1367 if (files) { 1368 /* 1369 * We are not taking a ref to the file structure, so we must 1370 * hold ->file_lock. 1371 */ 1372 spin_lock(&files->file_lock); 1373 file = fcheck_files(files, fd); 1374 if (file) { 1375 if (mnt) 1376 *mnt = mntget(file->f_path.mnt); 1377 if (dentry) 1378 *dentry = dget(file->f_path.dentry); 1379 if (info) 1380 snprintf(info, PROC_FDINFO_MAX, 1381 "pos:\t%lli\n" 1382 "flags:\t0%o\n", 1383 (long long) file->f_pos, 1384 file->f_flags); 1385 spin_unlock(&files->file_lock); 1386 put_files_struct(files); 1387 return 0; 1388 } 1389 spin_unlock(&files->file_lock); 1390 put_files_struct(files); 1391 } 1392 return -ENOENT; 1393 } 1394 1395 static int proc_fd_link(struct inode *inode, struct dentry **dentry, 1396 struct vfsmount **mnt) 1397 { 1398 return proc_fd_info(inode, dentry, mnt, NULL); 1399 } 1400 1401 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1402 { 1403 struct inode *inode = dentry->d_inode; 1404 struct task_struct *task = get_proc_task(inode); 1405 int fd = proc_fd(inode); 1406 struct files_struct *files; 1407 1408 if (task) { 1409 files = get_files_struct(task); 1410 if (files) { 1411 rcu_read_lock(); 1412 if (fcheck_files(files, fd)) { 1413 rcu_read_unlock(); 1414 put_files_struct(files); 1415 if (task_dumpable(task)) { 1416 inode->i_uid = task->euid; 1417 inode->i_gid = task->egid; 1418 } else { 1419 inode->i_uid = 0; 1420 inode->i_gid = 0; 1421 } 1422 inode->i_mode &= ~(S_ISUID | S_ISGID); 1423 security_task_to_inode(task, inode); 1424 put_task_struct(task); 1425 return 1; 1426 } 1427 rcu_read_unlock(); 1428 put_files_struct(files); 1429 } 1430 put_task_struct(task); 1431 } 1432 d_drop(dentry); 1433 return 0; 1434 } 1435 1436 static struct dentry_operations tid_fd_dentry_operations = 1437 { 1438 .d_revalidate = tid_fd_revalidate, 1439 .d_delete = pid_delete_dentry, 1440 }; 1441 1442 static struct dentry *proc_fd_instantiate(struct inode *dir, 1443 struct dentry *dentry, struct task_struct *task, const void *ptr) 1444 { 1445 unsigned fd = *(const unsigned *)ptr; 1446 struct file *file; 1447 struct files_struct *files; 1448 struct inode *inode; 1449 struct proc_inode *ei; 1450 struct dentry *error = ERR_PTR(-ENOENT); 1451 1452 inode = proc_pid_make_inode(dir->i_sb, task); 1453 if (!inode) 1454 goto out; 1455 ei = PROC_I(inode); 1456 ei->fd = fd; 1457 files = get_files_struct(task); 1458 if (!files) 1459 goto out_iput; 1460 inode->i_mode = S_IFLNK; 1461 1462 /* 1463 * We are not taking a ref to the file structure, so we must 1464 * hold ->file_lock. 1465 */ 1466 spin_lock(&files->file_lock); 1467 file = fcheck_files(files, fd); 1468 if (!file) 1469 goto out_unlock; 1470 if (file->f_mode & 1) 1471 inode->i_mode |= S_IRUSR | S_IXUSR; 1472 if (file->f_mode & 2) 1473 inode->i_mode |= S_IWUSR | S_IXUSR; 1474 spin_unlock(&files->file_lock); 1475 put_files_struct(files); 1476 1477 inode->i_op = &proc_pid_link_inode_operations; 1478 inode->i_size = 64; 1479 ei->op.proc_get_link = proc_fd_link; 1480 dentry->d_op = &tid_fd_dentry_operations; 1481 d_add(dentry, inode); 1482 /* Close the race of the process dying before we return the dentry */ 1483 if (tid_fd_revalidate(dentry, NULL)) 1484 error = NULL; 1485 1486 out: 1487 return error; 1488 out_unlock: 1489 spin_unlock(&files->file_lock); 1490 put_files_struct(files); 1491 out_iput: 1492 iput(inode); 1493 goto out; 1494 } 1495 1496 static struct dentry *proc_lookupfd_common(struct inode *dir, 1497 struct dentry *dentry, 1498 instantiate_t instantiate) 1499 { 1500 struct task_struct *task = get_proc_task(dir); 1501 unsigned fd = name_to_int(dentry); 1502 struct dentry *result = ERR_PTR(-ENOENT); 1503 1504 if (!task) 1505 goto out_no_task; 1506 if (fd == ~0U) 1507 goto out; 1508 1509 result = instantiate(dir, dentry, task, &fd); 1510 out: 1511 put_task_struct(task); 1512 out_no_task: 1513 return result; 1514 } 1515 1516 static int proc_readfd_common(struct file * filp, void * dirent, 1517 filldir_t filldir, instantiate_t instantiate) 1518 { 1519 struct dentry *dentry = filp->f_path.dentry; 1520 struct inode *inode = dentry->d_inode; 1521 struct task_struct *p = get_proc_task(inode); 1522 unsigned int fd, ino; 1523 int retval; 1524 struct files_struct * files; 1525 struct fdtable *fdt; 1526 1527 retval = -ENOENT; 1528 if (!p) 1529 goto out_no_task; 1530 retval = 0; 1531 1532 fd = filp->f_pos; 1533 switch (fd) { 1534 case 0: 1535 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 1536 goto out; 1537 filp->f_pos++; 1538 case 1: 1539 ino = parent_ino(dentry); 1540 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 1541 goto out; 1542 filp->f_pos++; 1543 default: 1544 files = get_files_struct(p); 1545 if (!files) 1546 goto out; 1547 rcu_read_lock(); 1548 fdt = files_fdtable(files); 1549 for (fd = filp->f_pos-2; 1550 fd < fdt->max_fds; 1551 fd++, filp->f_pos++) { 1552 char name[PROC_NUMBUF]; 1553 int len; 1554 1555 if (!fcheck_files(files, fd)) 1556 continue; 1557 rcu_read_unlock(); 1558 1559 len = snprintf(name, sizeof(name), "%d", fd); 1560 if (proc_fill_cache(filp, dirent, filldir, 1561 name, len, instantiate, 1562 p, &fd) < 0) { 1563 rcu_read_lock(); 1564 break; 1565 } 1566 rcu_read_lock(); 1567 } 1568 rcu_read_unlock(); 1569 put_files_struct(files); 1570 } 1571 out: 1572 put_task_struct(p); 1573 out_no_task: 1574 return retval; 1575 } 1576 1577 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 1578 struct nameidata *nd) 1579 { 1580 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 1581 } 1582 1583 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 1584 { 1585 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 1586 } 1587 1588 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 1589 size_t len, loff_t *ppos) 1590 { 1591 char tmp[PROC_FDINFO_MAX]; 1592 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, NULL, tmp); 1593 if (!err) 1594 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 1595 return err; 1596 } 1597 1598 static const struct file_operations proc_fdinfo_file_operations = { 1599 .open = nonseekable_open, 1600 .read = proc_fdinfo_read, 1601 }; 1602 1603 static const struct file_operations proc_fd_operations = { 1604 .read = generic_read_dir, 1605 .readdir = proc_readfd, 1606 }; 1607 1608 /* 1609 * /proc/pid/fd needs a special permission handler so that a process can still 1610 * access /proc/self/fd after it has executed a setuid(). 1611 */ 1612 static int proc_fd_permission(struct inode *inode, int mask, 1613 struct nameidata *nd) 1614 { 1615 int rv; 1616 1617 rv = generic_permission(inode, mask, NULL); 1618 if (rv == 0) 1619 return 0; 1620 if (task_pid(current) == proc_pid(inode)) 1621 rv = 0; 1622 return rv; 1623 } 1624 1625 /* 1626 * proc directories can do almost nothing.. 1627 */ 1628 static const struct inode_operations proc_fd_inode_operations = { 1629 .lookup = proc_lookupfd, 1630 .permission = proc_fd_permission, 1631 .setattr = proc_setattr, 1632 }; 1633 1634 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 1635 struct dentry *dentry, struct task_struct *task, const void *ptr) 1636 { 1637 unsigned fd = *(unsigned *)ptr; 1638 struct inode *inode; 1639 struct proc_inode *ei; 1640 struct dentry *error = ERR_PTR(-ENOENT); 1641 1642 inode = proc_pid_make_inode(dir->i_sb, task); 1643 if (!inode) 1644 goto out; 1645 ei = PROC_I(inode); 1646 ei->fd = fd; 1647 inode->i_mode = S_IFREG | S_IRUSR; 1648 inode->i_fop = &proc_fdinfo_file_operations; 1649 dentry->d_op = &tid_fd_dentry_operations; 1650 d_add(dentry, inode); 1651 /* Close the race of the process dying before we return the dentry */ 1652 if (tid_fd_revalidate(dentry, NULL)) 1653 error = NULL; 1654 1655 out: 1656 return error; 1657 } 1658 1659 static struct dentry *proc_lookupfdinfo(struct inode *dir, 1660 struct dentry *dentry, 1661 struct nameidata *nd) 1662 { 1663 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 1664 } 1665 1666 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 1667 { 1668 return proc_readfd_common(filp, dirent, filldir, 1669 proc_fdinfo_instantiate); 1670 } 1671 1672 static const struct file_operations proc_fdinfo_operations = { 1673 .read = generic_read_dir, 1674 .readdir = proc_readfdinfo, 1675 }; 1676 1677 /* 1678 * proc directories can do almost nothing.. 1679 */ 1680 static const struct inode_operations proc_fdinfo_inode_operations = { 1681 .lookup = proc_lookupfdinfo, 1682 .setattr = proc_setattr, 1683 }; 1684 1685 1686 static struct dentry *proc_pident_instantiate(struct inode *dir, 1687 struct dentry *dentry, struct task_struct *task, const void *ptr) 1688 { 1689 const struct pid_entry *p = ptr; 1690 struct inode *inode; 1691 struct proc_inode *ei; 1692 struct dentry *error = ERR_PTR(-EINVAL); 1693 1694 inode = proc_pid_make_inode(dir->i_sb, task); 1695 if (!inode) 1696 goto out; 1697 1698 ei = PROC_I(inode); 1699 inode->i_mode = p->mode; 1700 if (S_ISDIR(inode->i_mode)) 1701 inode->i_nlink = 2; /* Use getattr to fix if necessary */ 1702 if (p->iop) 1703 inode->i_op = p->iop; 1704 if (p->fop) 1705 inode->i_fop = p->fop; 1706 ei->op = p->op; 1707 dentry->d_op = &pid_dentry_operations; 1708 d_add(dentry, inode); 1709 /* Close the race of the process dying before we return the dentry */ 1710 if (pid_revalidate(dentry, NULL)) 1711 error = NULL; 1712 out: 1713 return error; 1714 } 1715 1716 static struct dentry *proc_pident_lookup(struct inode *dir, 1717 struct dentry *dentry, 1718 const struct pid_entry *ents, 1719 unsigned int nents) 1720 { 1721 struct inode *inode; 1722 struct dentry *error; 1723 struct task_struct *task = get_proc_task(dir); 1724 const struct pid_entry *p, *last; 1725 1726 error = ERR_PTR(-ENOENT); 1727 inode = NULL; 1728 1729 if (!task) 1730 goto out_no_task; 1731 1732 /* 1733 * Yes, it does not scale. And it should not. Don't add 1734 * new entries into /proc/<tgid>/ without very good reasons. 1735 */ 1736 last = &ents[nents - 1]; 1737 for (p = ents; p <= last; p++) { 1738 if (p->len != dentry->d_name.len) 1739 continue; 1740 if (!memcmp(dentry->d_name.name, p->name, p->len)) 1741 break; 1742 } 1743 if (p > last) 1744 goto out; 1745 1746 error = proc_pident_instantiate(dir, dentry, task, p); 1747 out: 1748 put_task_struct(task); 1749 out_no_task: 1750 return error; 1751 } 1752 1753 static int proc_pident_fill_cache(struct file *filp, void *dirent, 1754 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 1755 { 1756 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 1757 proc_pident_instantiate, task, p); 1758 } 1759 1760 static int proc_pident_readdir(struct file *filp, 1761 void *dirent, filldir_t filldir, 1762 const struct pid_entry *ents, unsigned int nents) 1763 { 1764 int i; 1765 struct dentry *dentry = filp->f_path.dentry; 1766 struct inode *inode = dentry->d_inode; 1767 struct task_struct *task = get_proc_task(inode); 1768 const struct pid_entry *p, *last; 1769 ino_t ino; 1770 int ret; 1771 1772 ret = -ENOENT; 1773 if (!task) 1774 goto out_no_task; 1775 1776 ret = 0; 1777 i = filp->f_pos; 1778 switch (i) { 1779 case 0: 1780 ino = inode->i_ino; 1781 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 1782 goto out; 1783 i++; 1784 filp->f_pos++; 1785 /* fall through */ 1786 case 1: 1787 ino = parent_ino(dentry); 1788 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 1789 goto out; 1790 i++; 1791 filp->f_pos++; 1792 /* fall through */ 1793 default: 1794 i -= 2; 1795 if (i >= nents) { 1796 ret = 1; 1797 goto out; 1798 } 1799 p = ents + i; 1800 last = &ents[nents - 1]; 1801 while (p <= last) { 1802 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 1803 goto out; 1804 filp->f_pos++; 1805 p++; 1806 } 1807 } 1808 1809 ret = 1; 1810 out: 1811 put_task_struct(task); 1812 out_no_task: 1813 return ret; 1814 } 1815 1816 #ifdef CONFIG_SECURITY 1817 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 1818 size_t count, loff_t *ppos) 1819 { 1820 struct inode * inode = file->f_path.dentry->d_inode; 1821 char *p = NULL; 1822 ssize_t length; 1823 struct task_struct *task = get_proc_task(inode); 1824 1825 if (!task) 1826 return -ESRCH; 1827 1828 length = security_getprocattr(task, 1829 (char*)file->f_path.dentry->d_name.name, 1830 &p); 1831 put_task_struct(task); 1832 if (length > 0) 1833 length = simple_read_from_buffer(buf, count, ppos, p, length); 1834 kfree(p); 1835 return length; 1836 } 1837 1838 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 1839 size_t count, loff_t *ppos) 1840 { 1841 struct inode * inode = file->f_path.dentry->d_inode; 1842 char *page; 1843 ssize_t length; 1844 struct task_struct *task = get_proc_task(inode); 1845 1846 length = -ESRCH; 1847 if (!task) 1848 goto out_no_task; 1849 if (count > PAGE_SIZE) 1850 count = PAGE_SIZE; 1851 1852 /* No partial writes. */ 1853 length = -EINVAL; 1854 if (*ppos != 0) 1855 goto out; 1856 1857 length = -ENOMEM; 1858 page = (char*)__get_free_page(GFP_TEMPORARY); 1859 if (!page) 1860 goto out; 1861 1862 length = -EFAULT; 1863 if (copy_from_user(page, buf, count)) 1864 goto out_free; 1865 1866 length = security_setprocattr(task, 1867 (char*)file->f_path.dentry->d_name.name, 1868 (void*)page, count); 1869 out_free: 1870 free_page((unsigned long) page); 1871 out: 1872 put_task_struct(task); 1873 out_no_task: 1874 return length; 1875 } 1876 1877 static const struct file_operations proc_pid_attr_operations = { 1878 .read = proc_pid_attr_read, 1879 .write = proc_pid_attr_write, 1880 }; 1881 1882 static const struct pid_entry attr_dir_stuff[] = { 1883 REG("current", S_IRUGO|S_IWUGO, pid_attr), 1884 REG("prev", S_IRUGO, pid_attr), 1885 REG("exec", S_IRUGO|S_IWUGO, pid_attr), 1886 REG("fscreate", S_IRUGO|S_IWUGO, pid_attr), 1887 REG("keycreate", S_IRUGO|S_IWUGO, pid_attr), 1888 REG("sockcreate", S_IRUGO|S_IWUGO, pid_attr), 1889 }; 1890 1891 static int proc_attr_dir_readdir(struct file * filp, 1892 void * dirent, filldir_t filldir) 1893 { 1894 return proc_pident_readdir(filp,dirent,filldir, 1895 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 1896 } 1897 1898 static const struct file_operations proc_attr_dir_operations = { 1899 .read = generic_read_dir, 1900 .readdir = proc_attr_dir_readdir, 1901 }; 1902 1903 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 1904 struct dentry *dentry, struct nameidata *nd) 1905 { 1906 return proc_pident_lookup(dir, dentry, 1907 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 1908 } 1909 1910 static const struct inode_operations proc_attr_dir_inode_operations = { 1911 .lookup = proc_attr_dir_lookup, 1912 .getattr = pid_getattr, 1913 .setattr = proc_setattr, 1914 }; 1915 1916 #endif 1917 1918 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 1919 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 1920 size_t count, loff_t *ppos) 1921 { 1922 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1923 struct mm_struct *mm; 1924 char buffer[PROC_NUMBUF]; 1925 size_t len; 1926 int ret; 1927 1928 if (!task) 1929 return -ESRCH; 1930 1931 ret = 0; 1932 mm = get_task_mm(task); 1933 if (mm) { 1934 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 1935 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 1936 MMF_DUMP_FILTER_SHIFT)); 1937 mmput(mm); 1938 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 1939 } 1940 1941 put_task_struct(task); 1942 1943 return ret; 1944 } 1945 1946 static ssize_t proc_coredump_filter_write(struct file *file, 1947 const char __user *buf, 1948 size_t count, 1949 loff_t *ppos) 1950 { 1951 struct task_struct *task; 1952 struct mm_struct *mm; 1953 char buffer[PROC_NUMBUF], *end; 1954 unsigned int val; 1955 int ret; 1956 int i; 1957 unsigned long mask; 1958 1959 ret = -EFAULT; 1960 memset(buffer, 0, sizeof(buffer)); 1961 if (count > sizeof(buffer) - 1) 1962 count = sizeof(buffer) - 1; 1963 if (copy_from_user(buffer, buf, count)) 1964 goto out_no_task; 1965 1966 ret = -EINVAL; 1967 val = (unsigned int)simple_strtoul(buffer, &end, 0); 1968 if (*end == '\n') 1969 end++; 1970 if (end - buffer == 0) 1971 goto out_no_task; 1972 1973 ret = -ESRCH; 1974 task = get_proc_task(file->f_dentry->d_inode); 1975 if (!task) 1976 goto out_no_task; 1977 1978 ret = end - buffer; 1979 mm = get_task_mm(task); 1980 if (!mm) 1981 goto out_no_mm; 1982 1983 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 1984 if (val & mask) 1985 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 1986 else 1987 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 1988 } 1989 1990 mmput(mm); 1991 out_no_mm: 1992 put_task_struct(task); 1993 out_no_task: 1994 return ret; 1995 } 1996 1997 static const struct file_operations proc_coredump_filter_operations = { 1998 .read = proc_coredump_filter_read, 1999 .write = proc_coredump_filter_write, 2000 }; 2001 #endif 2002 2003 /* 2004 * /proc/self: 2005 */ 2006 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2007 int buflen) 2008 { 2009 char tmp[PROC_NUMBUF]; 2010 sprintf(tmp, "%d", task_tgid_vnr(current)); 2011 return vfs_readlink(dentry,buffer,buflen,tmp); 2012 } 2013 2014 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2015 { 2016 char tmp[PROC_NUMBUF]; 2017 sprintf(tmp, "%d", task_tgid_vnr(current)); 2018 return ERR_PTR(vfs_follow_link(nd,tmp)); 2019 } 2020 2021 static const struct inode_operations proc_self_inode_operations = { 2022 .readlink = proc_self_readlink, 2023 .follow_link = proc_self_follow_link, 2024 }; 2025 2026 /* 2027 * proc base 2028 * 2029 * These are the directory entries in the root directory of /proc 2030 * that properly belong to the /proc filesystem, as they describe 2031 * describe something that is process related. 2032 */ 2033 static const struct pid_entry proc_base_stuff[] = { 2034 NOD("self", S_IFLNK|S_IRWXUGO, 2035 &proc_self_inode_operations, NULL, {}), 2036 }; 2037 2038 /* 2039 * Exceptional case: normally we are not allowed to unhash a busy 2040 * directory. In this case, however, we can do it - no aliasing problems 2041 * due to the way we treat inodes. 2042 */ 2043 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) 2044 { 2045 struct inode *inode = dentry->d_inode; 2046 struct task_struct *task = get_proc_task(inode); 2047 if (task) { 2048 put_task_struct(task); 2049 return 1; 2050 } 2051 d_drop(dentry); 2052 return 0; 2053 } 2054 2055 static struct dentry_operations proc_base_dentry_operations = 2056 { 2057 .d_revalidate = proc_base_revalidate, 2058 .d_delete = pid_delete_dentry, 2059 }; 2060 2061 static struct dentry *proc_base_instantiate(struct inode *dir, 2062 struct dentry *dentry, struct task_struct *task, const void *ptr) 2063 { 2064 const struct pid_entry *p = ptr; 2065 struct inode *inode; 2066 struct proc_inode *ei; 2067 struct dentry *error = ERR_PTR(-EINVAL); 2068 2069 /* Allocate the inode */ 2070 error = ERR_PTR(-ENOMEM); 2071 inode = new_inode(dir->i_sb); 2072 if (!inode) 2073 goto out; 2074 2075 /* Initialize the inode */ 2076 ei = PROC_I(inode); 2077 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2078 2079 /* 2080 * grab the reference to the task. 2081 */ 2082 ei->pid = get_task_pid(task, PIDTYPE_PID); 2083 if (!ei->pid) 2084 goto out_iput; 2085 2086 inode->i_uid = 0; 2087 inode->i_gid = 0; 2088 inode->i_mode = p->mode; 2089 if (S_ISDIR(inode->i_mode)) 2090 inode->i_nlink = 2; 2091 if (S_ISLNK(inode->i_mode)) 2092 inode->i_size = 64; 2093 if (p->iop) 2094 inode->i_op = p->iop; 2095 if (p->fop) 2096 inode->i_fop = p->fop; 2097 ei->op = p->op; 2098 dentry->d_op = &proc_base_dentry_operations; 2099 d_add(dentry, inode); 2100 error = NULL; 2101 out: 2102 return error; 2103 out_iput: 2104 iput(inode); 2105 goto out; 2106 } 2107 2108 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2109 { 2110 struct dentry *error; 2111 struct task_struct *task = get_proc_task(dir); 2112 const struct pid_entry *p, *last; 2113 2114 error = ERR_PTR(-ENOENT); 2115 2116 if (!task) 2117 goto out_no_task; 2118 2119 /* Lookup the directory entry */ 2120 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2121 for (p = proc_base_stuff; p <= last; p++) { 2122 if (p->len != dentry->d_name.len) 2123 continue; 2124 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2125 break; 2126 } 2127 if (p > last) 2128 goto out; 2129 2130 error = proc_base_instantiate(dir, dentry, task, p); 2131 2132 out: 2133 put_task_struct(task); 2134 out_no_task: 2135 return error; 2136 } 2137 2138 static int proc_base_fill_cache(struct file *filp, void *dirent, 2139 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2140 { 2141 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2142 proc_base_instantiate, task, p); 2143 } 2144 2145 #ifdef CONFIG_TASK_IO_ACCOUNTING 2146 static int proc_pid_io_accounting(struct task_struct *task, char *buffer) 2147 { 2148 return sprintf(buffer, 2149 #ifdef CONFIG_TASK_XACCT 2150 "rchar: %llu\n" 2151 "wchar: %llu\n" 2152 "syscr: %llu\n" 2153 "syscw: %llu\n" 2154 #endif 2155 "read_bytes: %llu\n" 2156 "write_bytes: %llu\n" 2157 "cancelled_write_bytes: %llu\n", 2158 #ifdef CONFIG_TASK_XACCT 2159 (unsigned long long)task->rchar, 2160 (unsigned long long)task->wchar, 2161 (unsigned long long)task->syscr, 2162 (unsigned long long)task->syscw, 2163 #endif 2164 (unsigned long long)task->ioac.read_bytes, 2165 (unsigned long long)task->ioac.write_bytes, 2166 (unsigned long long)task->ioac.cancelled_write_bytes); 2167 } 2168 #endif 2169 2170 /* 2171 * Thread groups 2172 */ 2173 static const struct file_operations proc_task_operations; 2174 static const struct inode_operations proc_task_inode_operations; 2175 2176 static const struct pid_entry tgid_base_stuff[] = { 2177 DIR("task", S_IRUGO|S_IXUGO, task), 2178 DIR("fd", S_IRUSR|S_IXUSR, fd), 2179 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), 2180 REG("environ", S_IRUSR, environ), 2181 INF("auxv", S_IRUSR, pid_auxv), 2182 INF("status", S_IRUGO, pid_status), 2183 INF("limits", S_IRUSR, pid_limits), 2184 #ifdef CONFIG_SCHED_DEBUG 2185 REG("sched", S_IRUGO|S_IWUSR, pid_sched), 2186 #endif 2187 INF("cmdline", S_IRUGO, pid_cmdline), 2188 INF("stat", S_IRUGO, tgid_stat), 2189 INF("statm", S_IRUGO, pid_statm), 2190 REG("maps", S_IRUGO, maps), 2191 #ifdef CONFIG_NUMA 2192 REG("numa_maps", S_IRUGO, numa_maps), 2193 #endif 2194 REG("mem", S_IRUSR|S_IWUSR, mem), 2195 LNK("cwd", cwd), 2196 LNK("root", root), 2197 LNK("exe", exe), 2198 REG("mounts", S_IRUGO, mounts), 2199 REG("mountstats", S_IRUSR, mountstats), 2200 #ifdef CONFIG_MMU 2201 REG("clear_refs", S_IWUSR, clear_refs), 2202 REG("smaps", S_IRUGO, smaps), 2203 #endif 2204 #ifdef CONFIG_SECURITY 2205 DIR("attr", S_IRUGO|S_IXUGO, attr_dir), 2206 #endif 2207 #ifdef CONFIG_KALLSYMS 2208 INF("wchan", S_IRUGO, pid_wchan), 2209 #endif 2210 #ifdef CONFIG_SCHEDSTATS 2211 INF("schedstat", S_IRUGO, pid_schedstat), 2212 #endif 2213 #ifdef CONFIG_PROC_PID_CPUSET 2214 REG("cpuset", S_IRUGO, cpuset), 2215 #endif 2216 #ifdef CONFIG_CGROUPS 2217 REG("cgroup", S_IRUGO, cgroup), 2218 #endif 2219 INF("oom_score", S_IRUGO, oom_score), 2220 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust), 2221 #ifdef CONFIG_AUDITSYSCALL 2222 REG("loginuid", S_IWUSR|S_IRUGO, loginuid), 2223 #endif 2224 #ifdef CONFIG_FAULT_INJECTION 2225 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject), 2226 #endif 2227 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2228 REG("coredump_filter", S_IRUGO|S_IWUSR, coredump_filter), 2229 #endif 2230 #ifdef CONFIG_TASK_IO_ACCOUNTING 2231 INF("io", S_IRUGO, pid_io_accounting), 2232 #endif 2233 }; 2234 2235 static int proc_tgid_base_readdir(struct file * filp, 2236 void * dirent, filldir_t filldir) 2237 { 2238 return proc_pident_readdir(filp,dirent,filldir, 2239 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2240 } 2241 2242 static const struct file_operations proc_tgid_base_operations = { 2243 .read = generic_read_dir, 2244 .readdir = proc_tgid_base_readdir, 2245 }; 2246 2247 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2248 return proc_pident_lookup(dir, dentry, 2249 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2250 } 2251 2252 static const struct inode_operations proc_tgid_base_inode_operations = { 2253 .lookup = proc_tgid_base_lookup, 2254 .getattr = pid_getattr, 2255 .setattr = proc_setattr, 2256 }; 2257 2258 /** 2259 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2260 * 2261 * @task: task that should be flushed. 2262 * 2263 * Looks in the dcache for 2264 * /proc/@pid 2265 * /proc/@tgid/task/@pid 2266 * if either directory is present flushes it and all of it'ts children 2267 * from the dcache. 2268 * 2269 * It is safe and reasonable to cache /proc entries for a task until 2270 * that task exits. After that they just clog up the dcache with 2271 * useless entries, possibly causing useful dcache entries to be 2272 * flushed instead. This routine is proved to flush those useless 2273 * dcache entries at process exit time. 2274 * 2275 * NOTE: This routine is just an optimization so it does not guarantee 2276 * that no dcache entries will exist at process exit time it 2277 * just makes it very unlikely that any will persist. 2278 */ 2279 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2280 { 2281 struct dentry *dentry, *leader, *dir; 2282 char buf[PROC_NUMBUF]; 2283 struct qstr name; 2284 2285 name.name = buf; 2286 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2287 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2288 if (dentry) { 2289 shrink_dcache_parent(dentry); 2290 d_drop(dentry); 2291 dput(dentry); 2292 } 2293 2294 if (tgid == 0) 2295 goto out; 2296 2297 name.name = buf; 2298 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2299 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2300 if (!leader) 2301 goto out; 2302 2303 name.name = "task"; 2304 name.len = strlen(name.name); 2305 dir = d_hash_and_lookup(leader, &name); 2306 if (!dir) 2307 goto out_put_leader; 2308 2309 name.name = buf; 2310 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2311 dentry = d_hash_and_lookup(dir, &name); 2312 if (dentry) { 2313 shrink_dcache_parent(dentry); 2314 d_drop(dentry); 2315 dput(dentry); 2316 } 2317 2318 dput(dir); 2319 out_put_leader: 2320 dput(leader); 2321 out: 2322 return; 2323 } 2324 2325 /* 2326 * when flushing dentries from proc one need to flush them from global 2327 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2328 * in. this call is supposed to make all this job. 2329 */ 2330 2331 void proc_flush_task(struct task_struct *task) 2332 { 2333 int i, leader; 2334 struct pid *pid, *tgid; 2335 struct upid *upid; 2336 2337 leader = thread_group_leader(task); 2338 proc_flush_task_mnt(proc_mnt, task->pid, leader ? task->tgid : 0); 2339 pid = task_pid(task); 2340 if (pid->level == 0) 2341 return; 2342 2343 tgid = task_tgid(task); 2344 for (i = 1; i <= pid->level; i++) { 2345 upid = &pid->numbers[i]; 2346 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 2347 leader ? 0 : tgid->numbers[i].nr); 2348 } 2349 2350 upid = &pid->numbers[pid->level]; 2351 if (upid->nr == 1) 2352 pid_ns_release_proc(upid->ns); 2353 } 2354 2355 static struct dentry *proc_pid_instantiate(struct inode *dir, 2356 struct dentry * dentry, 2357 struct task_struct *task, const void *ptr) 2358 { 2359 struct dentry *error = ERR_PTR(-ENOENT); 2360 struct inode *inode; 2361 2362 inode = proc_pid_make_inode(dir->i_sb, task); 2363 if (!inode) 2364 goto out; 2365 2366 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2367 inode->i_op = &proc_tgid_base_inode_operations; 2368 inode->i_fop = &proc_tgid_base_operations; 2369 inode->i_flags|=S_IMMUTABLE; 2370 inode->i_nlink = 5; 2371 #ifdef CONFIG_SECURITY 2372 inode->i_nlink += 1; 2373 #endif 2374 2375 dentry->d_op = &pid_dentry_operations; 2376 2377 d_add(dentry, inode); 2378 /* Close the race of the process dying before we return the dentry */ 2379 if (pid_revalidate(dentry, NULL)) 2380 error = NULL; 2381 out: 2382 return error; 2383 } 2384 2385 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2386 { 2387 struct dentry *result = ERR_PTR(-ENOENT); 2388 struct task_struct *task; 2389 unsigned tgid; 2390 struct pid_namespace *ns; 2391 2392 result = proc_base_lookup(dir, dentry); 2393 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 2394 goto out; 2395 2396 tgid = name_to_int(dentry); 2397 if (tgid == ~0U) 2398 goto out; 2399 2400 ns = dentry->d_sb->s_fs_info; 2401 rcu_read_lock(); 2402 task = find_task_by_pid_ns(tgid, ns); 2403 if (task) 2404 get_task_struct(task); 2405 rcu_read_unlock(); 2406 if (!task) 2407 goto out; 2408 2409 result = proc_pid_instantiate(dir, dentry, task, NULL); 2410 put_task_struct(task); 2411 out: 2412 return result; 2413 } 2414 2415 /* 2416 * Find the first task with tgid >= tgid 2417 * 2418 */ 2419 static struct task_struct *next_tgid(unsigned int tgid, 2420 struct pid_namespace *ns) 2421 { 2422 struct task_struct *task; 2423 struct pid *pid; 2424 2425 rcu_read_lock(); 2426 retry: 2427 task = NULL; 2428 pid = find_ge_pid(tgid, ns); 2429 if (pid) { 2430 tgid = pid_nr_ns(pid, ns) + 1; 2431 task = pid_task(pid, PIDTYPE_PID); 2432 /* What we to know is if the pid we have find is the 2433 * pid of a thread_group_leader. Testing for task 2434 * being a thread_group_leader is the obvious thing 2435 * todo but there is a window when it fails, due to 2436 * the pid transfer logic in de_thread. 2437 * 2438 * So we perform the straight forward test of seeing 2439 * if the pid we have found is the pid of a thread 2440 * group leader, and don't worry if the task we have 2441 * found doesn't happen to be a thread group leader. 2442 * As we don't care in the case of readdir. 2443 */ 2444 if (!task || !has_group_leader_pid(task)) 2445 goto retry; 2446 get_task_struct(task); 2447 } 2448 rcu_read_unlock(); 2449 return task; 2450 } 2451 2452 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 2453 2454 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2455 struct task_struct *task, int tgid) 2456 { 2457 char name[PROC_NUMBUF]; 2458 int len = snprintf(name, sizeof(name), "%d", tgid); 2459 return proc_fill_cache(filp, dirent, filldir, name, len, 2460 proc_pid_instantiate, task, NULL); 2461 } 2462 2463 /* for the /proc/ directory itself, after non-process stuff has been done */ 2464 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 2465 { 2466 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; 2467 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode); 2468 struct task_struct *task; 2469 int tgid; 2470 struct pid_namespace *ns; 2471 2472 if (!reaper) 2473 goto out_no_task; 2474 2475 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 2476 const struct pid_entry *p = &proc_base_stuff[nr]; 2477 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 2478 goto out; 2479 } 2480 2481 ns = filp->f_dentry->d_sb->s_fs_info; 2482 tgid = filp->f_pos - TGID_OFFSET; 2483 for (task = next_tgid(tgid, ns); 2484 task; 2485 put_task_struct(task), task = next_tgid(tgid + 1, ns)) { 2486 tgid = task_pid_nr_ns(task, ns); 2487 filp->f_pos = tgid + TGID_OFFSET; 2488 if (proc_pid_fill_cache(filp, dirent, filldir, task, tgid) < 0) { 2489 put_task_struct(task); 2490 goto out; 2491 } 2492 } 2493 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 2494 out: 2495 put_task_struct(reaper); 2496 out_no_task: 2497 return 0; 2498 } 2499 2500 /* 2501 * Tasks 2502 */ 2503 static const struct pid_entry tid_base_stuff[] = { 2504 DIR("fd", S_IRUSR|S_IXUSR, fd), 2505 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), 2506 REG("environ", S_IRUSR, environ), 2507 INF("auxv", S_IRUSR, pid_auxv), 2508 INF("status", S_IRUGO, pid_status), 2509 INF("limits", S_IRUSR, pid_limits), 2510 #ifdef CONFIG_SCHED_DEBUG 2511 REG("sched", S_IRUGO|S_IWUSR, pid_sched), 2512 #endif 2513 INF("cmdline", S_IRUGO, pid_cmdline), 2514 INF("stat", S_IRUGO, tid_stat), 2515 INF("statm", S_IRUGO, pid_statm), 2516 REG("maps", S_IRUGO, maps), 2517 #ifdef CONFIG_NUMA 2518 REG("numa_maps", S_IRUGO, numa_maps), 2519 #endif 2520 REG("mem", S_IRUSR|S_IWUSR, mem), 2521 LNK("cwd", cwd), 2522 LNK("root", root), 2523 LNK("exe", exe), 2524 REG("mounts", S_IRUGO, mounts), 2525 #ifdef CONFIG_MMU 2526 REG("clear_refs", S_IWUSR, clear_refs), 2527 REG("smaps", S_IRUGO, smaps), 2528 #endif 2529 #ifdef CONFIG_SECURITY 2530 DIR("attr", S_IRUGO|S_IXUGO, attr_dir), 2531 #endif 2532 #ifdef CONFIG_KALLSYMS 2533 INF("wchan", S_IRUGO, pid_wchan), 2534 #endif 2535 #ifdef CONFIG_SCHEDSTATS 2536 INF("schedstat", S_IRUGO, pid_schedstat), 2537 #endif 2538 #ifdef CONFIG_PROC_PID_CPUSET 2539 REG("cpuset", S_IRUGO, cpuset), 2540 #endif 2541 #ifdef CONFIG_CGROUPS 2542 REG("cgroup", S_IRUGO, cgroup), 2543 #endif 2544 INF("oom_score", S_IRUGO, oom_score), 2545 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust), 2546 #ifdef CONFIG_AUDITSYSCALL 2547 REG("loginuid", S_IWUSR|S_IRUGO, loginuid), 2548 #endif 2549 #ifdef CONFIG_FAULT_INJECTION 2550 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject), 2551 #endif 2552 }; 2553 2554 static int proc_tid_base_readdir(struct file * filp, 2555 void * dirent, filldir_t filldir) 2556 { 2557 return proc_pident_readdir(filp,dirent,filldir, 2558 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 2559 } 2560 2561 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2562 return proc_pident_lookup(dir, dentry, 2563 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 2564 } 2565 2566 static const struct file_operations proc_tid_base_operations = { 2567 .read = generic_read_dir, 2568 .readdir = proc_tid_base_readdir, 2569 }; 2570 2571 static const struct inode_operations proc_tid_base_inode_operations = { 2572 .lookup = proc_tid_base_lookup, 2573 .getattr = pid_getattr, 2574 .setattr = proc_setattr, 2575 }; 2576 2577 static struct dentry *proc_task_instantiate(struct inode *dir, 2578 struct dentry *dentry, struct task_struct *task, const void *ptr) 2579 { 2580 struct dentry *error = ERR_PTR(-ENOENT); 2581 struct inode *inode; 2582 inode = proc_pid_make_inode(dir->i_sb, task); 2583 2584 if (!inode) 2585 goto out; 2586 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2587 inode->i_op = &proc_tid_base_inode_operations; 2588 inode->i_fop = &proc_tid_base_operations; 2589 inode->i_flags|=S_IMMUTABLE; 2590 inode->i_nlink = 4; 2591 #ifdef CONFIG_SECURITY 2592 inode->i_nlink += 1; 2593 #endif 2594 2595 dentry->d_op = &pid_dentry_operations; 2596 2597 d_add(dentry, inode); 2598 /* Close the race of the process dying before we return the dentry */ 2599 if (pid_revalidate(dentry, NULL)) 2600 error = NULL; 2601 out: 2602 return error; 2603 } 2604 2605 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2606 { 2607 struct dentry *result = ERR_PTR(-ENOENT); 2608 struct task_struct *task; 2609 struct task_struct *leader = get_proc_task(dir); 2610 unsigned tid; 2611 struct pid_namespace *ns; 2612 2613 if (!leader) 2614 goto out_no_task; 2615 2616 tid = name_to_int(dentry); 2617 if (tid == ~0U) 2618 goto out; 2619 2620 ns = dentry->d_sb->s_fs_info; 2621 rcu_read_lock(); 2622 task = find_task_by_pid_ns(tid, ns); 2623 if (task) 2624 get_task_struct(task); 2625 rcu_read_unlock(); 2626 if (!task) 2627 goto out; 2628 if (!same_thread_group(leader, task)) 2629 goto out_drop_task; 2630 2631 result = proc_task_instantiate(dir, dentry, task, NULL); 2632 out_drop_task: 2633 put_task_struct(task); 2634 out: 2635 put_task_struct(leader); 2636 out_no_task: 2637 return result; 2638 } 2639 2640 /* 2641 * Find the first tid of a thread group to return to user space. 2642 * 2643 * Usually this is just the thread group leader, but if the users 2644 * buffer was too small or there was a seek into the middle of the 2645 * directory we have more work todo. 2646 * 2647 * In the case of a short read we start with find_task_by_pid. 2648 * 2649 * In the case of a seek we start with the leader and walk nr 2650 * threads past it. 2651 */ 2652 static struct task_struct *first_tid(struct task_struct *leader, 2653 int tid, int nr, struct pid_namespace *ns) 2654 { 2655 struct task_struct *pos; 2656 2657 rcu_read_lock(); 2658 /* Attempt to start with the pid of a thread */ 2659 if (tid && (nr > 0)) { 2660 pos = find_task_by_pid_ns(tid, ns); 2661 if (pos && (pos->group_leader == leader)) 2662 goto found; 2663 } 2664 2665 /* If nr exceeds the number of threads there is nothing todo */ 2666 pos = NULL; 2667 if (nr && nr >= get_nr_threads(leader)) 2668 goto out; 2669 2670 /* If we haven't found our starting place yet start 2671 * with the leader and walk nr threads forward. 2672 */ 2673 for (pos = leader; nr > 0; --nr) { 2674 pos = next_thread(pos); 2675 if (pos == leader) { 2676 pos = NULL; 2677 goto out; 2678 } 2679 } 2680 found: 2681 get_task_struct(pos); 2682 out: 2683 rcu_read_unlock(); 2684 return pos; 2685 } 2686 2687 /* 2688 * Find the next thread in the thread list. 2689 * Return NULL if there is an error or no next thread. 2690 * 2691 * The reference to the input task_struct is released. 2692 */ 2693 static struct task_struct *next_tid(struct task_struct *start) 2694 { 2695 struct task_struct *pos = NULL; 2696 rcu_read_lock(); 2697 if (pid_alive(start)) { 2698 pos = next_thread(start); 2699 if (thread_group_leader(pos)) 2700 pos = NULL; 2701 else 2702 get_task_struct(pos); 2703 } 2704 rcu_read_unlock(); 2705 put_task_struct(start); 2706 return pos; 2707 } 2708 2709 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2710 struct task_struct *task, int tid) 2711 { 2712 char name[PROC_NUMBUF]; 2713 int len = snprintf(name, sizeof(name), "%d", tid); 2714 return proc_fill_cache(filp, dirent, filldir, name, len, 2715 proc_task_instantiate, task, NULL); 2716 } 2717 2718 /* for the /proc/TGID/task/ directories */ 2719 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 2720 { 2721 struct dentry *dentry = filp->f_path.dentry; 2722 struct inode *inode = dentry->d_inode; 2723 struct task_struct *leader = NULL; 2724 struct task_struct *task; 2725 int retval = -ENOENT; 2726 ino_t ino; 2727 int tid; 2728 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */ 2729 struct pid_namespace *ns; 2730 2731 task = get_proc_task(inode); 2732 if (!task) 2733 goto out_no_task; 2734 rcu_read_lock(); 2735 if (pid_alive(task)) { 2736 leader = task->group_leader; 2737 get_task_struct(leader); 2738 } 2739 rcu_read_unlock(); 2740 put_task_struct(task); 2741 if (!leader) 2742 goto out_no_task; 2743 retval = 0; 2744 2745 switch (pos) { 2746 case 0: 2747 ino = inode->i_ino; 2748 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0) 2749 goto out; 2750 pos++; 2751 /* fall through */ 2752 case 1: 2753 ino = parent_ino(dentry); 2754 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0) 2755 goto out; 2756 pos++; 2757 /* fall through */ 2758 } 2759 2760 /* f_version caches the tgid value that the last readdir call couldn't 2761 * return. lseek aka telldir automagically resets f_version to 0. 2762 */ 2763 ns = filp->f_dentry->d_sb->s_fs_info; 2764 tid = (int)filp->f_version; 2765 filp->f_version = 0; 2766 for (task = first_tid(leader, tid, pos - 2, ns); 2767 task; 2768 task = next_tid(task), pos++) { 2769 tid = task_pid_nr_ns(task, ns); 2770 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 2771 /* returning this tgid failed, save it as the first 2772 * pid for the next readir call */ 2773 filp->f_version = (u64)tid; 2774 put_task_struct(task); 2775 break; 2776 } 2777 } 2778 out: 2779 filp->f_pos = pos; 2780 put_task_struct(leader); 2781 out_no_task: 2782 return retval; 2783 } 2784 2785 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 2786 { 2787 struct inode *inode = dentry->d_inode; 2788 struct task_struct *p = get_proc_task(inode); 2789 generic_fillattr(inode, stat); 2790 2791 if (p) { 2792 rcu_read_lock(); 2793 stat->nlink += get_nr_threads(p); 2794 rcu_read_unlock(); 2795 put_task_struct(p); 2796 } 2797 2798 return 0; 2799 } 2800 2801 static const struct inode_operations proc_task_inode_operations = { 2802 .lookup = proc_task_lookup, 2803 .getattr = proc_task_getattr, 2804 .setattr = proc_setattr, 2805 }; 2806 2807 static const struct file_operations proc_task_operations = { 2808 .read = generic_read_dir, 2809 .readdir = proc_task_readdir, 2810 }; 2811