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 struct pid_entry { 92 char *name; 93 int len; 94 mode_t mode; 95 const struct inode_operations *iop; 96 const struct file_operations *fop; 97 union proc_op op; 98 }; 99 100 #define NOD(NAME, MODE, IOP, FOP, OP) { \ 101 .name = (NAME), \ 102 .len = sizeof(NAME) - 1, \ 103 .mode = MODE, \ 104 .iop = IOP, \ 105 .fop = FOP, \ 106 .op = OP, \ 107 } 108 109 #define DIR(NAME, MODE, OTYPE) \ 110 NOD(NAME, (S_IFDIR|(MODE)), \ 111 &proc_##OTYPE##_inode_operations, &proc_##OTYPE##_operations, \ 112 {} ) 113 #define LNK(NAME, OTYPE) \ 114 NOD(NAME, (S_IFLNK|S_IRWXUGO), \ 115 &proc_pid_link_inode_operations, NULL, \ 116 { .proc_get_link = &proc_##OTYPE##_link } ) 117 #define REG(NAME, MODE, OTYPE) \ 118 NOD(NAME, (S_IFREG|(MODE)), NULL, \ 119 &proc_##OTYPE##_operations, {}) 120 #define INF(NAME, MODE, OTYPE) \ 121 NOD(NAME, (S_IFREG|(MODE)), \ 122 NULL, &proc_info_file_operations, \ 123 { .proc_read = &proc_##OTYPE } ) 124 #define ONE(NAME, MODE, OTYPE) \ 125 NOD(NAME, (S_IFREG|(MODE)), \ 126 NULL, &proc_single_file_operations, \ 127 { .proc_show = &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_is_stopped_or_traced(task)) && \ 203 security_ptrace(current,task) == 0)) 204 205 struct mm_struct *mm_for_maps(struct task_struct *task) 206 { 207 struct mm_struct *mm = get_task_mm(task); 208 if (!mm) 209 return NULL; 210 down_read(&mm->mmap_sem); 211 task_lock(task); 212 if (task->mm != mm) 213 goto out; 214 if (task->mm != current->mm && __ptrace_may_attach(task) < 0) 215 goto out; 216 task_unlock(task); 217 return mm; 218 out: 219 task_unlock(task); 220 up_read(&mm->mmap_sem); 221 mmput(mm); 222 return NULL; 223 } 224 225 static int proc_pid_cmdline(struct task_struct *task, char * buffer) 226 { 227 int res = 0; 228 unsigned int len; 229 struct mm_struct *mm = get_task_mm(task); 230 if (!mm) 231 goto out; 232 if (!mm->arg_end) 233 goto out_mm; /* Shh! No looking before we're done */ 234 235 len = mm->arg_end - mm->arg_start; 236 237 if (len > PAGE_SIZE) 238 len = PAGE_SIZE; 239 240 res = access_process_vm(task, mm->arg_start, buffer, len, 0); 241 242 // If the nul at the end of args has been overwritten, then 243 // assume application is using setproctitle(3). 244 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) { 245 len = strnlen(buffer, res); 246 if (len < res) { 247 res = len; 248 } else { 249 len = mm->env_end - mm->env_start; 250 if (len > PAGE_SIZE - res) 251 len = PAGE_SIZE - res; 252 res += access_process_vm(task, mm->env_start, buffer+res, len, 0); 253 res = strnlen(buffer, res); 254 } 255 } 256 out_mm: 257 mmput(mm); 258 out: 259 return res; 260 } 261 262 static int proc_pid_auxv(struct task_struct *task, char *buffer) 263 { 264 int res = 0; 265 struct mm_struct *mm = get_task_mm(task); 266 if (mm) { 267 unsigned int nwords = 0; 268 do 269 nwords += 2; 270 while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */ 271 res = nwords * sizeof(mm->saved_auxv[0]); 272 if (res > PAGE_SIZE) 273 res = PAGE_SIZE; 274 memcpy(buffer, mm->saved_auxv, res); 275 mmput(mm); 276 } 277 return res; 278 } 279 280 281 #ifdef CONFIG_KALLSYMS 282 /* 283 * Provides a wchan file via kallsyms in a proper one-value-per-file format. 284 * Returns the resolved symbol. If that fails, simply return the address. 285 */ 286 static int proc_pid_wchan(struct task_struct *task, char *buffer) 287 { 288 unsigned long wchan; 289 char symname[KSYM_NAME_LEN]; 290 291 wchan = get_wchan(task); 292 293 if (lookup_symbol_name(wchan, symname) < 0) 294 return sprintf(buffer, "%lu", wchan); 295 else 296 return sprintf(buffer, "%s", symname); 297 } 298 #endif /* CONFIG_KALLSYMS */ 299 300 #ifdef CONFIG_SCHEDSTATS 301 /* 302 * Provides /proc/PID/schedstat 303 */ 304 static int proc_pid_schedstat(struct task_struct *task, char *buffer) 305 { 306 return sprintf(buffer, "%llu %llu %lu\n", 307 task->sched_info.cpu_time, 308 task->sched_info.run_delay, 309 task->sched_info.pcount); 310 } 311 #endif 312 313 #ifdef CONFIG_LATENCYTOP 314 static int lstats_show_proc(struct seq_file *m, void *v) 315 { 316 int i; 317 struct task_struct *task = m->private; 318 seq_puts(m, "Latency Top version : v0.1\n"); 319 320 for (i = 0; i < 32; i++) { 321 if (task->latency_record[i].backtrace[0]) { 322 int q; 323 seq_printf(m, "%i %li %li ", 324 task->latency_record[i].count, 325 task->latency_record[i].time, 326 task->latency_record[i].max); 327 for (q = 0; q < LT_BACKTRACEDEPTH; q++) { 328 char sym[KSYM_NAME_LEN]; 329 char *c; 330 if (!task->latency_record[i].backtrace[q]) 331 break; 332 if (task->latency_record[i].backtrace[q] == ULONG_MAX) 333 break; 334 sprint_symbol(sym, task->latency_record[i].backtrace[q]); 335 c = strchr(sym, '+'); 336 if (c) 337 *c = 0; 338 seq_printf(m, "%s ", sym); 339 } 340 seq_printf(m, "\n"); 341 } 342 343 } 344 return 0; 345 } 346 347 static int lstats_open(struct inode *inode, struct file *file) 348 { 349 int ret; 350 struct seq_file *m; 351 struct task_struct *task = get_proc_task(inode); 352 353 ret = single_open(file, lstats_show_proc, NULL); 354 if (!ret) { 355 m = file->private_data; 356 m->private = task; 357 } 358 return ret; 359 } 360 361 static ssize_t lstats_write(struct file *file, const char __user *buf, 362 size_t count, loff_t *offs) 363 { 364 struct seq_file *m; 365 struct task_struct *task; 366 367 m = file->private_data; 368 task = m->private; 369 clear_all_latency_tracing(task); 370 371 return count; 372 } 373 374 static const struct file_operations proc_lstats_operations = { 375 .open = lstats_open, 376 .read = seq_read, 377 .write = lstats_write, 378 .llseek = seq_lseek, 379 .release = single_release, 380 }; 381 382 #endif 383 384 /* The badness from the OOM killer */ 385 unsigned long badness(struct task_struct *p, unsigned long uptime); 386 static int proc_oom_score(struct task_struct *task, char *buffer) 387 { 388 unsigned long points; 389 struct timespec uptime; 390 391 do_posix_clock_monotonic_gettime(&uptime); 392 read_lock(&tasklist_lock); 393 points = badness(task, uptime.tv_sec); 394 read_unlock(&tasklist_lock); 395 return sprintf(buffer, "%lu\n", points); 396 } 397 398 struct limit_names { 399 char *name; 400 char *unit; 401 }; 402 403 static const struct limit_names lnames[RLIM_NLIMITS] = { 404 [RLIMIT_CPU] = {"Max cpu time", "ms"}, 405 [RLIMIT_FSIZE] = {"Max file size", "bytes"}, 406 [RLIMIT_DATA] = {"Max data size", "bytes"}, 407 [RLIMIT_STACK] = {"Max stack size", "bytes"}, 408 [RLIMIT_CORE] = {"Max core file size", "bytes"}, 409 [RLIMIT_RSS] = {"Max resident set", "bytes"}, 410 [RLIMIT_NPROC] = {"Max processes", "processes"}, 411 [RLIMIT_NOFILE] = {"Max open files", "files"}, 412 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, 413 [RLIMIT_AS] = {"Max address space", "bytes"}, 414 [RLIMIT_LOCKS] = {"Max file locks", "locks"}, 415 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, 416 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, 417 [RLIMIT_NICE] = {"Max nice priority", NULL}, 418 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, 419 }; 420 421 /* Display limits for a process */ 422 static int proc_pid_limits(struct task_struct *task, char *buffer) 423 { 424 unsigned int i; 425 int count = 0; 426 unsigned long flags; 427 char *bufptr = buffer; 428 429 struct rlimit rlim[RLIM_NLIMITS]; 430 431 rcu_read_lock(); 432 if (!lock_task_sighand(task,&flags)) { 433 rcu_read_unlock(); 434 return 0; 435 } 436 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); 437 unlock_task_sighand(task, &flags); 438 rcu_read_unlock(); 439 440 /* 441 * print the file header 442 */ 443 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n", 444 "Limit", "Soft Limit", "Hard Limit", "Units"); 445 446 for (i = 0; i < RLIM_NLIMITS; i++) { 447 if (rlim[i].rlim_cur == RLIM_INFINITY) 448 count += sprintf(&bufptr[count], "%-25s %-20s ", 449 lnames[i].name, "unlimited"); 450 else 451 count += sprintf(&bufptr[count], "%-25s %-20lu ", 452 lnames[i].name, rlim[i].rlim_cur); 453 454 if (rlim[i].rlim_max == RLIM_INFINITY) 455 count += sprintf(&bufptr[count], "%-20s ", "unlimited"); 456 else 457 count += sprintf(&bufptr[count], "%-20lu ", 458 rlim[i].rlim_max); 459 460 if (lnames[i].unit) 461 count += sprintf(&bufptr[count], "%-10s\n", 462 lnames[i].unit); 463 else 464 count += sprintf(&bufptr[count], "\n"); 465 } 466 467 return count; 468 } 469 470 /************************************************************************/ 471 /* Here the fs part begins */ 472 /************************************************************************/ 473 474 /* permission checks */ 475 static int proc_fd_access_allowed(struct inode *inode) 476 { 477 struct task_struct *task; 478 int allowed = 0; 479 /* Allow access to a task's file descriptors if it is us or we 480 * may use ptrace attach to the process and find out that 481 * information. 482 */ 483 task = get_proc_task(inode); 484 if (task) { 485 allowed = ptrace_may_attach(task); 486 put_task_struct(task); 487 } 488 return allowed; 489 } 490 491 static int proc_setattr(struct dentry *dentry, struct iattr *attr) 492 { 493 int error; 494 struct inode *inode = dentry->d_inode; 495 496 if (attr->ia_valid & ATTR_MODE) 497 return -EPERM; 498 499 error = inode_change_ok(inode, attr); 500 if (!error) 501 error = inode_setattr(inode, attr); 502 return error; 503 } 504 505 static const struct inode_operations proc_def_inode_operations = { 506 .setattr = proc_setattr, 507 }; 508 509 extern const struct seq_operations mounts_op; 510 struct proc_mounts { 511 struct seq_file m; 512 int event; 513 }; 514 515 static int mounts_open(struct inode *inode, struct file *file) 516 { 517 struct task_struct *task = get_proc_task(inode); 518 struct nsproxy *nsp; 519 struct mnt_namespace *ns = NULL; 520 struct proc_mounts *p; 521 int ret = -EINVAL; 522 523 if (task) { 524 rcu_read_lock(); 525 nsp = task_nsproxy(task); 526 if (nsp) { 527 ns = nsp->mnt_ns; 528 if (ns) 529 get_mnt_ns(ns); 530 } 531 rcu_read_unlock(); 532 533 put_task_struct(task); 534 } 535 536 if (ns) { 537 ret = -ENOMEM; 538 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL); 539 if (p) { 540 file->private_data = &p->m; 541 ret = seq_open(file, &mounts_op); 542 if (!ret) { 543 p->m.private = ns; 544 p->event = ns->event; 545 return 0; 546 } 547 kfree(p); 548 } 549 put_mnt_ns(ns); 550 } 551 return ret; 552 } 553 554 static int mounts_release(struct inode *inode, struct file *file) 555 { 556 struct seq_file *m = file->private_data; 557 struct mnt_namespace *ns = m->private; 558 put_mnt_ns(ns); 559 return seq_release(inode, file); 560 } 561 562 static unsigned mounts_poll(struct file *file, poll_table *wait) 563 { 564 struct proc_mounts *p = file->private_data; 565 struct mnt_namespace *ns = p->m.private; 566 unsigned res = 0; 567 568 poll_wait(file, &ns->poll, wait); 569 570 spin_lock(&vfsmount_lock); 571 if (p->event != ns->event) { 572 p->event = ns->event; 573 res = POLLERR; 574 } 575 spin_unlock(&vfsmount_lock); 576 577 return res; 578 } 579 580 static const struct file_operations proc_mounts_operations = { 581 .open = mounts_open, 582 .read = seq_read, 583 .llseek = seq_lseek, 584 .release = mounts_release, 585 .poll = mounts_poll, 586 }; 587 588 extern const struct seq_operations mountstats_op; 589 static int mountstats_open(struct inode *inode, struct file *file) 590 { 591 int ret = seq_open(file, &mountstats_op); 592 593 if (!ret) { 594 struct seq_file *m = file->private_data; 595 struct nsproxy *nsp; 596 struct mnt_namespace *mnt_ns = NULL; 597 struct task_struct *task = get_proc_task(inode); 598 599 if (task) { 600 rcu_read_lock(); 601 nsp = task_nsproxy(task); 602 if (nsp) { 603 mnt_ns = nsp->mnt_ns; 604 if (mnt_ns) 605 get_mnt_ns(mnt_ns); 606 } 607 rcu_read_unlock(); 608 609 put_task_struct(task); 610 } 611 612 if (mnt_ns) 613 m->private = mnt_ns; 614 else { 615 seq_release(inode, file); 616 ret = -EINVAL; 617 } 618 } 619 return ret; 620 } 621 622 static const struct file_operations proc_mountstats_operations = { 623 .open = mountstats_open, 624 .read = seq_read, 625 .llseek = seq_lseek, 626 .release = mounts_release, 627 }; 628 629 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */ 630 631 static ssize_t proc_info_read(struct file * file, char __user * buf, 632 size_t count, loff_t *ppos) 633 { 634 struct inode * inode = file->f_path.dentry->d_inode; 635 unsigned long page; 636 ssize_t length; 637 struct task_struct *task = get_proc_task(inode); 638 639 length = -ESRCH; 640 if (!task) 641 goto out_no_task; 642 643 if (count > PROC_BLOCK_SIZE) 644 count = PROC_BLOCK_SIZE; 645 646 length = -ENOMEM; 647 if (!(page = __get_free_page(GFP_TEMPORARY))) 648 goto out; 649 650 length = PROC_I(inode)->op.proc_read(task, (char*)page); 651 652 if (length >= 0) 653 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length); 654 free_page(page); 655 out: 656 put_task_struct(task); 657 out_no_task: 658 return length; 659 } 660 661 static const struct file_operations proc_info_file_operations = { 662 .read = proc_info_read, 663 }; 664 665 static int proc_single_show(struct seq_file *m, void *v) 666 { 667 struct inode *inode = m->private; 668 struct pid_namespace *ns; 669 struct pid *pid; 670 struct task_struct *task; 671 int ret; 672 673 ns = inode->i_sb->s_fs_info; 674 pid = proc_pid(inode); 675 task = get_pid_task(pid, PIDTYPE_PID); 676 if (!task) 677 return -ESRCH; 678 679 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); 680 681 put_task_struct(task); 682 return ret; 683 } 684 685 static int proc_single_open(struct inode *inode, struct file *filp) 686 { 687 int ret; 688 ret = single_open(filp, proc_single_show, NULL); 689 if (!ret) { 690 struct seq_file *m = filp->private_data; 691 692 m->private = inode; 693 } 694 return ret; 695 } 696 697 static const struct file_operations proc_single_file_operations = { 698 .open = proc_single_open, 699 .read = seq_read, 700 .llseek = seq_lseek, 701 .release = single_release, 702 }; 703 704 static int mem_open(struct inode* inode, struct file* file) 705 { 706 file->private_data = (void*)((long)current->self_exec_id); 707 return 0; 708 } 709 710 static ssize_t mem_read(struct file * file, char __user * buf, 711 size_t count, loff_t *ppos) 712 { 713 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 714 char *page; 715 unsigned long src = *ppos; 716 int ret = -ESRCH; 717 struct mm_struct *mm; 718 719 if (!task) 720 goto out_no_task; 721 722 if (!MAY_PTRACE(task) || !ptrace_may_attach(task)) 723 goto out; 724 725 ret = -ENOMEM; 726 page = (char *)__get_free_page(GFP_TEMPORARY); 727 if (!page) 728 goto out; 729 730 ret = 0; 731 732 mm = get_task_mm(task); 733 if (!mm) 734 goto out_free; 735 736 ret = -EIO; 737 738 if (file->private_data != (void*)((long)current->self_exec_id)) 739 goto out_put; 740 741 ret = 0; 742 743 while (count > 0) { 744 int this_len, retval; 745 746 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 747 retval = access_process_vm(task, src, page, this_len, 0); 748 if (!retval || !MAY_PTRACE(task) || !ptrace_may_attach(task)) { 749 if (!ret) 750 ret = -EIO; 751 break; 752 } 753 754 if (copy_to_user(buf, page, retval)) { 755 ret = -EFAULT; 756 break; 757 } 758 759 ret += retval; 760 src += retval; 761 buf += retval; 762 count -= retval; 763 } 764 *ppos = src; 765 766 out_put: 767 mmput(mm); 768 out_free: 769 free_page((unsigned long) page); 770 out: 771 put_task_struct(task); 772 out_no_task: 773 return ret; 774 } 775 776 #define mem_write NULL 777 778 #ifndef mem_write 779 /* This is a security hazard */ 780 static ssize_t mem_write(struct file * file, const char __user *buf, 781 size_t count, loff_t *ppos) 782 { 783 int copied; 784 char *page; 785 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 786 unsigned long dst = *ppos; 787 788 copied = -ESRCH; 789 if (!task) 790 goto out_no_task; 791 792 if (!MAY_PTRACE(task) || !ptrace_may_attach(task)) 793 goto out; 794 795 copied = -ENOMEM; 796 page = (char *)__get_free_page(GFP_TEMPORARY); 797 if (!page) 798 goto out; 799 800 copied = 0; 801 while (count > 0) { 802 int this_len, retval; 803 804 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 805 if (copy_from_user(page, buf, this_len)) { 806 copied = -EFAULT; 807 break; 808 } 809 retval = access_process_vm(task, dst, page, this_len, 1); 810 if (!retval) { 811 if (!copied) 812 copied = -EIO; 813 break; 814 } 815 copied += retval; 816 buf += retval; 817 dst += retval; 818 count -= retval; 819 } 820 *ppos = dst; 821 free_page((unsigned long) page); 822 out: 823 put_task_struct(task); 824 out_no_task: 825 return copied; 826 } 827 #endif 828 829 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 830 { 831 switch (orig) { 832 case 0: 833 file->f_pos = offset; 834 break; 835 case 1: 836 file->f_pos += offset; 837 break; 838 default: 839 return -EINVAL; 840 } 841 force_successful_syscall_return(); 842 return file->f_pos; 843 } 844 845 static const struct file_operations proc_mem_operations = { 846 .llseek = mem_lseek, 847 .read = mem_read, 848 .write = mem_write, 849 .open = mem_open, 850 }; 851 852 static ssize_t environ_read(struct file *file, char __user *buf, 853 size_t count, loff_t *ppos) 854 { 855 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 856 char *page; 857 unsigned long src = *ppos; 858 int ret = -ESRCH; 859 struct mm_struct *mm; 860 861 if (!task) 862 goto out_no_task; 863 864 if (!ptrace_may_attach(task)) 865 goto out; 866 867 ret = -ENOMEM; 868 page = (char *)__get_free_page(GFP_TEMPORARY); 869 if (!page) 870 goto out; 871 872 ret = 0; 873 874 mm = get_task_mm(task); 875 if (!mm) 876 goto out_free; 877 878 while (count > 0) { 879 int this_len, retval, max_len; 880 881 this_len = mm->env_end - (mm->env_start + src); 882 883 if (this_len <= 0) 884 break; 885 886 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; 887 this_len = (this_len > max_len) ? max_len : this_len; 888 889 retval = access_process_vm(task, (mm->env_start + src), 890 page, this_len, 0); 891 892 if (retval <= 0) { 893 ret = retval; 894 break; 895 } 896 897 if (copy_to_user(buf, page, retval)) { 898 ret = -EFAULT; 899 break; 900 } 901 902 ret += retval; 903 src += retval; 904 buf += retval; 905 count -= retval; 906 } 907 *ppos = src; 908 909 mmput(mm); 910 out_free: 911 free_page((unsigned long) page); 912 out: 913 put_task_struct(task); 914 out_no_task: 915 return ret; 916 } 917 918 static const struct file_operations proc_environ_operations = { 919 .read = environ_read, 920 }; 921 922 static ssize_t oom_adjust_read(struct file *file, char __user *buf, 923 size_t count, loff_t *ppos) 924 { 925 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); 926 char buffer[PROC_NUMBUF]; 927 size_t len; 928 int oom_adjust; 929 930 if (!task) 931 return -ESRCH; 932 oom_adjust = task->oomkilladj; 933 put_task_struct(task); 934 935 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); 936 937 return simple_read_from_buffer(buf, count, ppos, buffer, len); 938 } 939 940 static ssize_t oom_adjust_write(struct file *file, const char __user *buf, 941 size_t count, loff_t *ppos) 942 { 943 struct task_struct *task; 944 char buffer[PROC_NUMBUF], *end; 945 int oom_adjust; 946 947 memset(buffer, 0, sizeof(buffer)); 948 if (count > sizeof(buffer) - 1) 949 count = sizeof(buffer) - 1; 950 if (copy_from_user(buffer, buf, count)) 951 return -EFAULT; 952 oom_adjust = simple_strtol(buffer, &end, 0); 953 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) && 954 oom_adjust != OOM_DISABLE) 955 return -EINVAL; 956 if (*end == '\n') 957 end++; 958 task = get_proc_task(file->f_path.dentry->d_inode); 959 if (!task) 960 return -ESRCH; 961 if (oom_adjust < task->oomkilladj && !capable(CAP_SYS_RESOURCE)) { 962 put_task_struct(task); 963 return -EACCES; 964 } 965 task->oomkilladj = oom_adjust; 966 put_task_struct(task); 967 if (end - buffer == 0) 968 return -EIO; 969 return end - buffer; 970 } 971 972 static const struct file_operations proc_oom_adjust_operations = { 973 .read = oom_adjust_read, 974 .write = oom_adjust_write, 975 }; 976 977 #ifdef CONFIG_AUDITSYSCALL 978 #define TMPBUFLEN 21 979 static ssize_t proc_loginuid_read(struct file * file, char __user * buf, 980 size_t count, loff_t *ppos) 981 { 982 struct inode * inode = file->f_path.dentry->d_inode; 983 struct task_struct *task = get_proc_task(inode); 984 ssize_t length; 985 char tmpbuf[TMPBUFLEN]; 986 987 if (!task) 988 return -ESRCH; 989 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", 990 audit_get_loginuid(task)); 991 put_task_struct(task); 992 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); 993 } 994 995 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, 996 size_t count, loff_t *ppos) 997 { 998 struct inode * inode = file->f_path.dentry->d_inode; 999 char *page, *tmp; 1000 ssize_t length; 1001 uid_t loginuid; 1002 1003 if (!capable(CAP_AUDIT_CONTROL)) 1004 return -EPERM; 1005 1006 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) 1007 return -EPERM; 1008 1009 if (count >= PAGE_SIZE) 1010 count = PAGE_SIZE - 1; 1011 1012 if (*ppos != 0) { 1013 /* No partial writes. */ 1014 return -EINVAL; 1015 } 1016 page = (char*)__get_free_page(GFP_TEMPORARY); 1017 if (!page) 1018 return -ENOMEM; 1019 length = -EFAULT; 1020 if (copy_from_user(page, buf, count)) 1021 goto out_free_page; 1022 1023 page[count] = '\0'; 1024 loginuid = simple_strtoul(page, &tmp, 10); 1025 if (tmp == page) { 1026 length = -EINVAL; 1027 goto out_free_page; 1028 1029 } 1030 length = audit_set_loginuid(current, loginuid); 1031 if (likely(length == 0)) 1032 length = count; 1033 1034 out_free_page: 1035 free_page((unsigned long) page); 1036 return length; 1037 } 1038 1039 static const struct file_operations proc_loginuid_operations = { 1040 .read = proc_loginuid_read, 1041 .write = proc_loginuid_write, 1042 }; 1043 #endif 1044 1045 #ifdef CONFIG_FAULT_INJECTION 1046 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf, 1047 size_t count, loff_t *ppos) 1048 { 1049 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1050 char buffer[PROC_NUMBUF]; 1051 size_t len; 1052 int make_it_fail; 1053 1054 if (!task) 1055 return -ESRCH; 1056 make_it_fail = task->make_it_fail; 1057 put_task_struct(task); 1058 1059 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail); 1060 1061 return simple_read_from_buffer(buf, count, ppos, buffer, len); 1062 } 1063 1064 static ssize_t proc_fault_inject_write(struct file * file, 1065 const char __user * buf, size_t count, loff_t *ppos) 1066 { 1067 struct task_struct *task; 1068 char buffer[PROC_NUMBUF], *end; 1069 int make_it_fail; 1070 1071 if (!capable(CAP_SYS_RESOURCE)) 1072 return -EPERM; 1073 memset(buffer, 0, sizeof(buffer)); 1074 if (count > sizeof(buffer) - 1) 1075 count = sizeof(buffer) - 1; 1076 if (copy_from_user(buffer, buf, count)) 1077 return -EFAULT; 1078 make_it_fail = simple_strtol(buffer, &end, 0); 1079 if (*end == '\n') 1080 end++; 1081 task = get_proc_task(file->f_dentry->d_inode); 1082 if (!task) 1083 return -ESRCH; 1084 task->make_it_fail = make_it_fail; 1085 put_task_struct(task); 1086 if (end - buffer == 0) 1087 return -EIO; 1088 return end - buffer; 1089 } 1090 1091 static const struct file_operations proc_fault_inject_operations = { 1092 .read = proc_fault_inject_read, 1093 .write = proc_fault_inject_write, 1094 }; 1095 #endif 1096 1097 1098 #ifdef CONFIG_SCHED_DEBUG 1099 /* 1100 * Print out various scheduling related per-task fields: 1101 */ 1102 static int sched_show(struct seq_file *m, void *v) 1103 { 1104 struct inode *inode = m->private; 1105 struct task_struct *p; 1106 1107 WARN_ON(!inode); 1108 1109 p = get_proc_task(inode); 1110 if (!p) 1111 return -ESRCH; 1112 proc_sched_show_task(p, m); 1113 1114 put_task_struct(p); 1115 1116 return 0; 1117 } 1118 1119 static ssize_t 1120 sched_write(struct file *file, const char __user *buf, 1121 size_t count, loff_t *offset) 1122 { 1123 struct inode *inode = file->f_path.dentry->d_inode; 1124 struct task_struct *p; 1125 1126 WARN_ON(!inode); 1127 1128 p = get_proc_task(inode); 1129 if (!p) 1130 return -ESRCH; 1131 proc_sched_set_task(p); 1132 1133 put_task_struct(p); 1134 1135 return count; 1136 } 1137 1138 static int sched_open(struct inode *inode, struct file *filp) 1139 { 1140 int ret; 1141 1142 ret = single_open(filp, sched_show, NULL); 1143 if (!ret) { 1144 struct seq_file *m = filp->private_data; 1145 1146 m->private = inode; 1147 } 1148 return ret; 1149 } 1150 1151 static const struct file_operations proc_pid_sched_operations = { 1152 .open = sched_open, 1153 .read = seq_read, 1154 .write = sched_write, 1155 .llseek = seq_lseek, 1156 .release = single_release, 1157 }; 1158 1159 #endif 1160 1161 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 1162 { 1163 struct inode *inode = dentry->d_inode; 1164 int error = -EACCES; 1165 1166 /* We don't need a base pointer in the /proc filesystem */ 1167 path_release(nd); 1168 1169 /* Are we allowed to snoop on the tasks file descriptors? */ 1170 if (!proc_fd_access_allowed(inode)) 1171 goto out; 1172 1173 error = PROC_I(inode)->op.proc_get_link(inode, &nd->dentry, &nd->mnt); 1174 nd->last_type = LAST_BIND; 1175 out: 1176 return ERR_PTR(error); 1177 } 1178 1179 static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt, 1180 char __user *buffer, int buflen) 1181 { 1182 struct inode * inode; 1183 char *tmp = (char*)__get_free_page(GFP_TEMPORARY); 1184 char *path; 1185 int len; 1186 1187 if (!tmp) 1188 return -ENOMEM; 1189 1190 inode = dentry->d_inode; 1191 path = d_path(dentry, mnt, tmp, PAGE_SIZE); 1192 len = PTR_ERR(path); 1193 if (IS_ERR(path)) 1194 goto out; 1195 len = tmp + PAGE_SIZE - 1 - path; 1196 1197 if (len > buflen) 1198 len = buflen; 1199 if (copy_to_user(buffer, path, len)) 1200 len = -EFAULT; 1201 out: 1202 free_page((unsigned long)tmp); 1203 return len; 1204 } 1205 1206 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1207 { 1208 int error = -EACCES; 1209 struct inode *inode = dentry->d_inode; 1210 struct dentry *de; 1211 struct vfsmount *mnt = NULL; 1212 1213 /* Are we allowed to snoop on the tasks file descriptors? */ 1214 if (!proc_fd_access_allowed(inode)) 1215 goto out; 1216 1217 error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt); 1218 if (error) 1219 goto out; 1220 1221 error = do_proc_readlink(de, mnt, buffer, buflen); 1222 dput(de); 1223 mntput(mnt); 1224 out: 1225 return error; 1226 } 1227 1228 static const struct inode_operations proc_pid_link_inode_operations = { 1229 .readlink = proc_pid_readlink, 1230 .follow_link = proc_pid_follow_link, 1231 .setattr = proc_setattr, 1232 }; 1233 1234 1235 /* building an inode */ 1236 1237 static int task_dumpable(struct task_struct *task) 1238 { 1239 int dumpable = 0; 1240 struct mm_struct *mm; 1241 1242 task_lock(task); 1243 mm = task->mm; 1244 if (mm) 1245 dumpable = get_dumpable(mm); 1246 task_unlock(task); 1247 if(dumpable == 1) 1248 return 1; 1249 return 0; 1250 } 1251 1252 1253 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1254 { 1255 struct inode * inode; 1256 struct proc_inode *ei; 1257 1258 /* We need a new inode */ 1259 1260 inode = new_inode(sb); 1261 if (!inode) 1262 goto out; 1263 1264 /* Common stuff */ 1265 ei = PROC_I(inode); 1266 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1267 inode->i_op = &proc_def_inode_operations; 1268 1269 /* 1270 * grab the reference to task. 1271 */ 1272 ei->pid = get_task_pid(task, PIDTYPE_PID); 1273 if (!ei->pid) 1274 goto out_unlock; 1275 1276 inode->i_uid = 0; 1277 inode->i_gid = 0; 1278 if (task_dumpable(task)) { 1279 inode->i_uid = task->euid; 1280 inode->i_gid = task->egid; 1281 } 1282 security_task_to_inode(task, inode); 1283 1284 out: 1285 return inode; 1286 1287 out_unlock: 1288 iput(inode); 1289 return NULL; 1290 } 1291 1292 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1293 { 1294 struct inode *inode = dentry->d_inode; 1295 struct task_struct *task; 1296 generic_fillattr(inode, stat); 1297 1298 rcu_read_lock(); 1299 stat->uid = 0; 1300 stat->gid = 0; 1301 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1302 if (task) { 1303 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1304 task_dumpable(task)) { 1305 stat->uid = task->euid; 1306 stat->gid = task->egid; 1307 } 1308 } 1309 rcu_read_unlock(); 1310 return 0; 1311 } 1312 1313 /* dentry stuff */ 1314 1315 /* 1316 * Exceptional case: normally we are not allowed to unhash a busy 1317 * directory. In this case, however, we can do it - no aliasing problems 1318 * due to the way we treat inodes. 1319 * 1320 * Rewrite the inode's ownerships here because the owning task may have 1321 * performed a setuid(), etc. 1322 * 1323 * Before the /proc/pid/status file was created the only way to read 1324 * the effective uid of a /process was to stat /proc/pid. Reading 1325 * /proc/pid/status is slow enough that procps and other packages 1326 * kept stating /proc/pid. To keep the rules in /proc simple I have 1327 * made this apply to all per process world readable and executable 1328 * directories. 1329 */ 1330 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1331 { 1332 struct inode *inode = dentry->d_inode; 1333 struct task_struct *task = get_proc_task(inode); 1334 if (task) { 1335 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1336 task_dumpable(task)) { 1337 inode->i_uid = task->euid; 1338 inode->i_gid = task->egid; 1339 } else { 1340 inode->i_uid = 0; 1341 inode->i_gid = 0; 1342 } 1343 inode->i_mode &= ~(S_ISUID | S_ISGID); 1344 security_task_to_inode(task, inode); 1345 put_task_struct(task); 1346 return 1; 1347 } 1348 d_drop(dentry); 1349 return 0; 1350 } 1351 1352 static int pid_delete_dentry(struct dentry * dentry) 1353 { 1354 /* Is the task we represent dead? 1355 * If so, then don't put the dentry on the lru list, 1356 * kill it immediately. 1357 */ 1358 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1359 } 1360 1361 static struct dentry_operations pid_dentry_operations = 1362 { 1363 .d_revalidate = pid_revalidate, 1364 .d_delete = pid_delete_dentry, 1365 }; 1366 1367 /* Lookups */ 1368 1369 typedef struct dentry *instantiate_t(struct inode *, struct dentry *, 1370 struct task_struct *, const void *); 1371 1372 /* 1373 * Fill a directory entry. 1374 * 1375 * If possible create the dcache entry and derive our inode number and 1376 * file type from dcache entry. 1377 * 1378 * Since all of the proc inode numbers are dynamically generated, the inode 1379 * numbers do not exist until the inode is cache. This means creating the 1380 * the dcache entry in readdir is necessary to keep the inode numbers 1381 * reported by readdir in sync with the inode numbers reported 1382 * by stat. 1383 */ 1384 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1385 char *name, int len, 1386 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1387 { 1388 struct dentry *child, *dir = filp->f_path.dentry; 1389 struct inode *inode; 1390 struct qstr qname; 1391 ino_t ino = 0; 1392 unsigned type = DT_UNKNOWN; 1393 1394 qname.name = name; 1395 qname.len = len; 1396 qname.hash = full_name_hash(name, len); 1397 1398 child = d_lookup(dir, &qname); 1399 if (!child) { 1400 struct dentry *new; 1401 new = d_alloc(dir, &qname); 1402 if (new) { 1403 child = instantiate(dir->d_inode, new, task, ptr); 1404 if (child) 1405 dput(new); 1406 else 1407 child = new; 1408 } 1409 } 1410 if (!child || IS_ERR(child) || !child->d_inode) 1411 goto end_instantiate; 1412 inode = child->d_inode; 1413 if (inode) { 1414 ino = inode->i_ino; 1415 type = inode->i_mode >> 12; 1416 } 1417 dput(child); 1418 end_instantiate: 1419 if (!ino) 1420 ino = find_inode_number(dir, &qname); 1421 if (!ino) 1422 ino = 1; 1423 return filldir(dirent, name, len, filp->f_pos, ino, type); 1424 } 1425 1426 static unsigned name_to_int(struct dentry *dentry) 1427 { 1428 const char *name = dentry->d_name.name; 1429 int len = dentry->d_name.len; 1430 unsigned n = 0; 1431 1432 if (len > 1 && *name == '0') 1433 goto out; 1434 while (len-- > 0) { 1435 unsigned c = *name++ - '0'; 1436 if (c > 9) 1437 goto out; 1438 if (n >= (~0U-9)/10) 1439 goto out; 1440 n *= 10; 1441 n += c; 1442 } 1443 return n; 1444 out: 1445 return ~0U; 1446 } 1447 1448 #define PROC_FDINFO_MAX 64 1449 1450 static int proc_fd_info(struct inode *inode, struct dentry **dentry, 1451 struct vfsmount **mnt, char *info) 1452 { 1453 struct task_struct *task = get_proc_task(inode); 1454 struct files_struct *files = NULL; 1455 struct file *file; 1456 int fd = proc_fd(inode); 1457 1458 if (task) { 1459 files = get_files_struct(task); 1460 put_task_struct(task); 1461 } 1462 if (files) { 1463 /* 1464 * We are not taking a ref to the file structure, so we must 1465 * hold ->file_lock. 1466 */ 1467 spin_lock(&files->file_lock); 1468 file = fcheck_files(files, fd); 1469 if (file) { 1470 if (mnt) 1471 *mnt = mntget(file->f_path.mnt); 1472 if (dentry) 1473 *dentry = dget(file->f_path.dentry); 1474 if (info) 1475 snprintf(info, PROC_FDINFO_MAX, 1476 "pos:\t%lli\n" 1477 "flags:\t0%o\n", 1478 (long long) file->f_pos, 1479 file->f_flags); 1480 spin_unlock(&files->file_lock); 1481 put_files_struct(files); 1482 return 0; 1483 } 1484 spin_unlock(&files->file_lock); 1485 put_files_struct(files); 1486 } 1487 return -ENOENT; 1488 } 1489 1490 static int proc_fd_link(struct inode *inode, struct dentry **dentry, 1491 struct vfsmount **mnt) 1492 { 1493 return proc_fd_info(inode, dentry, mnt, NULL); 1494 } 1495 1496 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1497 { 1498 struct inode *inode = dentry->d_inode; 1499 struct task_struct *task = get_proc_task(inode); 1500 int fd = proc_fd(inode); 1501 struct files_struct *files; 1502 1503 if (task) { 1504 files = get_files_struct(task); 1505 if (files) { 1506 rcu_read_lock(); 1507 if (fcheck_files(files, fd)) { 1508 rcu_read_unlock(); 1509 put_files_struct(files); 1510 if (task_dumpable(task)) { 1511 inode->i_uid = task->euid; 1512 inode->i_gid = task->egid; 1513 } else { 1514 inode->i_uid = 0; 1515 inode->i_gid = 0; 1516 } 1517 inode->i_mode &= ~(S_ISUID | S_ISGID); 1518 security_task_to_inode(task, inode); 1519 put_task_struct(task); 1520 return 1; 1521 } 1522 rcu_read_unlock(); 1523 put_files_struct(files); 1524 } 1525 put_task_struct(task); 1526 } 1527 d_drop(dentry); 1528 return 0; 1529 } 1530 1531 static struct dentry_operations tid_fd_dentry_operations = 1532 { 1533 .d_revalidate = tid_fd_revalidate, 1534 .d_delete = pid_delete_dentry, 1535 }; 1536 1537 static struct dentry *proc_fd_instantiate(struct inode *dir, 1538 struct dentry *dentry, struct task_struct *task, const void *ptr) 1539 { 1540 unsigned fd = *(const unsigned *)ptr; 1541 struct file *file; 1542 struct files_struct *files; 1543 struct inode *inode; 1544 struct proc_inode *ei; 1545 struct dentry *error = ERR_PTR(-ENOENT); 1546 1547 inode = proc_pid_make_inode(dir->i_sb, task); 1548 if (!inode) 1549 goto out; 1550 ei = PROC_I(inode); 1551 ei->fd = fd; 1552 files = get_files_struct(task); 1553 if (!files) 1554 goto out_iput; 1555 inode->i_mode = S_IFLNK; 1556 1557 /* 1558 * We are not taking a ref to the file structure, so we must 1559 * hold ->file_lock. 1560 */ 1561 spin_lock(&files->file_lock); 1562 file = fcheck_files(files, fd); 1563 if (!file) 1564 goto out_unlock; 1565 if (file->f_mode & 1) 1566 inode->i_mode |= S_IRUSR | S_IXUSR; 1567 if (file->f_mode & 2) 1568 inode->i_mode |= S_IWUSR | S_IXUSR; 1569 spin_unlock(&files->file_lock); 1570 put_files_struct(files); 1571 1572 inode->i_op = &proc_pid_link_inode_operations; 1573 inode->i_size = 64; 1574 ei->op.proc_get_link = proc_fd_link; 1575 dentry->d_op = &tid_fd_dentry_operations; 1576 d_add(dentry, inode); 1577 /* Close the race of the process dying before we return the dentry */ 1578 if (tid_fd_revalidate(dentry, NULL)) 1579 error = NULL; 1580 1581 out: 1582 return error; 1583 out_unlock: 1584 spin_unlock(&files->file_lock); 1585 put_files_struct(files); 1586 out_iput: 1587 iput(inode); 1588 goto out; 1589 } 1590 1591 static struct dentry *proc_lookupfd_common(struct inode *dir, 1592 struct dentry *dentry, 1593 instantiate_t instantiate) 1594 { 1595 struct task_struct *task = get_proc_task(dir); 1596 unsigned fd = name_to_int(dentry); 1597 struct dentry *result = ERR_PTR(-ENOENT); 1598 1599 if (!task) 1600 goto out_no_task; 1601 if (fd == ~0U) 1602 goto out; 1603 1604 result = instantiate(dir, dentry, task, &fd); 1605 out: 1606 put_task_struct(task); 1607 out_no_task: 1608 return result; 1609 } 1610 1611 static int proc_readfd_common(struct file * filp, void * dirent, 1612 filldir_t filldir, instantiate_t instantiate) 1613 { 1614 struct dentry *dentry = filp->f_path.dentry; 1615 struct inode *inode = dentry->d_inode; 1616 struct task_struct *p = get_proc_task(inode); 1617 unsigned int fd, ino; 1618 int retval; 1619 struct files_struct * files; 1620 struct fdtable *fdt; 1621 1622 retval = -ENOENT; 1623 if (!p) 1624 goto out_no_task; 1625 retval = 0; 1626 1627 fd = filp->f_pos; 1628 switch (fd) { 1629 case 0: 1630 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 1631 goto out; 1632 filp->f_pos++; 1633 case 1: 1634 ino = parent_ino(dentry); 1635 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 1636 goto out; 1637 filp->f_pos++; 1638 default: 1639 files = get_files_struct(p); 1640 if (!files) 1641 goto out; 1642 rcu_read_lock(); 1643 fdt = files_fdtable(files); 1644 for (fd = filp->f_pos-2; 1645 fd < fdt->max_fds; 1646 fd++, filp->f_pos++) { 1647 char name[PROC_NUMBUF]; 1648 int len; 1649 1650 if (!fcheck_files(files, fd)) 1651 continue; 1652 rcu_read_unlock(); 1653 1654 len = snprintf(name, sizeof(name), "%d", fd); 1655 if (proc_fill_cache(filp, dirent, filldir, 1656 name, len, instantiate, 1657 p, &fd) < 0) { 1658 rcu_read_lock(); 1659 break; 1660 } 1661 rcu_read_lock(); 1662 } 1663 rcu_read_unlock(); 1664 put_files_struct(files); 1665 } 1666 out: 1667 put_task_struct(p); 1668 out_no_task: 1669 return retval; 1670 } 1671 1672 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 1673 struct nameidata *nd) 1674 { 1675 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 1676 } 1677 1678 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 1679 { 1680 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 1681 } 1682 1683 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 1684 size_t len, loff_t *ppos) 1685 { 1686 char tmp[PROC_FDINFO_MAX]; 1687 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, NULL, tmp); 1688 if (!err) 1689 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 1690 return err; 1691 } 1692 1693 static const struct file_operations proc_fdinfo_file_operations = { 1694 .open = nonseekable_open, 1695 .read = proc_fdinfo_read, 1696 }; 1697 1698 static const struct file_operations proc_fd_operations = { 1699 .read = generic_read_dir, 1700 .readdir = proc_readfd, 1701 }; 1702 1703 /* 1704 * /proc/pid/fd needs a special permission handler so that a process can still 1705 * access /proc/self/fd after it has executed a setuid(). 1706 */ 1707 static int proc_fd_permission(struct inode *inode, int mask, 1708 struct nameidata *nd) 1709 { 1710 int rv; 1711 1712 rv = generic_permission(inode, mask, NULL); 1713 if (rv == 0) 1714 return 0; 1715 if (task_pid(current) == proc_pid(inode)) 1716 rv = 0; 1717 return rv; 1718 } 1719 1720 /* 1721 * proc directories can do almost nothing.. 1722 */ 1723 static const struct inode_operations proc_fd_inode_operations = { 1724 .lookup = proc_lookupfd, 1725 .permission = proc_fd_permission, 1726 .setattr = proc_setattr, 1727 }; 1728 1729 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 1730 struct dentry *dentry, struct task_struct *task, const void *ptr) 1731 { 1732 unsigned fd = *(unsigned *)ptr; 1733 struct inode *inode; 1734 struct proc_inode *ei; 1735 struct dentry *error = ERR_PTR(-ENOENT); 1736 1737 inode = proc_pid_make_inode(dir->i_sb, task); 1738 if (!inode) 1739 goto out; 1740 ei = PROC_I(inode); 1741 ei->fd = fd; 1742 inode->i_mode = S_IFREG | S_IRUSR; 1743 inode->i_fop = &proc_fdinfo_file_operations; 1744 dentry->d_op = &tid_fd_dentry_operations; 1745 d_add(dentry, inode); 1746 /* Close the race of the process dying before we return the dentry */ 1747 if (tid_fd_revalidate(dentry, NULL)) 1748 error = NULL; 1749 1750 out: 1751 return error; 1752 } 1753 1754 static struct dentry *proc_lookupfdinfo(struct inode *dir, 1755 struct dentry *dentry, 1756 struct nameidata *nd) 1757 { 1758 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 1759 } 1760 1761 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 1762 { 1763 return proc_readfd_common(filp, dirent, filldir, 1764 proc_fdinfo_instantiate); 1765 } 1766 1767 static const struct file_operations proc_fdinfo_operations = { 1768 .read = generic_read_dir, 1769 .readdir = proc_readfdinfo, 1770 }; 1771 1772 /* 1773 * proc directories can do almost nothing.. 1774 */ 1775 static const struct inode_operations proc_fdinfo_inode_operations = { 1776 .lookup = proc_lookupfdinfo, 1777 .setattr = proc_setattr, 1778 }; 1779 1780 1781 static struct dentry *proc_pident_instantiate(struct inode *dir, 1782 struct dentry *dentry, struct task_struct *task, const void *ptr) 1783 { 1784 const struct pid_entry *p = ptr; 1785 struct inode *inode; 1786 struct proc_inode *ei; 1787 struct dentry *error = ERR_PTR(-EINVAL); 1788 1789 inode = proc_pid_make_inode(dir->i_sb, task); 1790 if (!inode) 1791 goto out; 1792 1793 ei = PROC_I(inode); 1794 inode->i_mode = p->mode; 1795 if (S_ISDIR(inode->i_mode)) 1796 inode->i_nlink = 2; /* Use getattr to fix if necessary */ 1797 if (p->iop) 1798 inode->i_op = p->iop; 1799 if (p->fop) 1800 inode->i_fop = p->fop; 1801 ei->op = p->op; 1802 dentry->d_op = &pid_dentry_operations; 1803 d_add(dentry, inode); 1804 /* Close the race of the process dying before we return the dentry */ 1805 if (pid_revalidate(dentry, NULL)) 1806 error = NULL; 1807 out: 1808 return error; 1809 } 1810 1811 static struct dentry *proc_pident_lookup(struct inode *dir, 1812 struct dentry *dentry, 1813 const struct pid_entry *ents, 1814 unsigned int nents) 1815 { 1816 struct inode *inode; 1817 struct dentry *error; 1818 struct task_struct *task = get_proc_task(dir); 1819 const struct pid_entry *p, *last; 1820 1821 error = ERR_PTR(-ENOENT); 1822 inode = NULL; 1823 1824 if (!task) 1825 goto out_no_task; 1826 1827 /* 1828 * Yes, it does not scale. And it should not. Don't add 1829 * new entries into /proc/<tgid>/ without very good reasons. 1830 */ 1831 last = &ents[nents - 1]; 1832 for (p = ents; p <= last; p++) { 1833 if (p->len != dentry->d_name.len) 1834 continue; 1835 if (!memcmp(dentry->d_name.name, p->name, p->len)) 1836 break; 1837 } 1838 if (p > last) 1839 goto out; 1840 1841 error = proc_pident_instantiate(dir, dentry, task, p); 1842 out: 1843 put_task_struct(task); 1844 out_no_task: 1845 return error; 1846 } 1847 1848 static int proc_pident_fill_cache(struct file *filp, void *dirent, 1849 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 1850 { 1851 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 1852 proc_pident_instantiate, task, p); 1853 } 1854 1855 static int proc_pident_readdir(struct file *filp, 1856 void *dirent, filldir_t filldir, 1857 const struct pid_entry *ents, unsigned int nents) 1858 { 1859 int i; 1860 struct dentry *dentry = filp->f_path.dentry; 1861 struct inode *inode = dentry->d_inode; 1862 struct task_struct *task = get_proc_task(inode); 1863 const struct pid_entry *p, *last; 1864 ino_t ino; 1865 int ret; 1866 1867 ret = -ENOENT; 1868 if (!task) 1869 goto out_no_task; 1870 1871 ret = 0; 1872 i = filp->f_pos; 1873 switch (i) { 1874 case 0: 1875 ino = inode->i_ino; 1876 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 1877 goto out; 1878 i++; 1879 filp->f_pos++; 1880 /* fall through */ 1881 case 1: 1882 ino = parent_ino(dentry); 1883 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 1884 goto out; 1885 i++; 1886 filp->f_pos++; 1887 /* fall through */ 1888 default: 1889 i -= 2; 1890 if (i >= nents) { 1891 ret = 1; 1892 goto out; 1893 } 1894 p = ents + i; 1895 last = &ents[nents - 1]; 1896 while (p <= last) { 1897 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 1898 goto out; 1899 filp->f_pos++; 1900 p++; 1901 } 1902 } 1903 1904 ret = 1; 1905 out: 1906 put_task_struct(task); 1907 out_no_task: 1908 return ret; 1909 } 1910 1911 #ifdef CONFIG_SECURITY 1912 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 1913 size_t count, loff_t *ppos) 1914 { 1915 struct inode * inode = file->f_path.dentry->d_inode; 1916 char *p = NULL; 1917 ssize_t length; 1918 struct task_struct *task = get_proc_task(inode); 1919 1920 if (!task) 1921 return -ESRCH; 1922 1923 length = security_getprocattr(task, 1924 (char*)file->f_path.dentry->d_name.name, 1925 &p); 1926 put_task_struct(task); 1927 if (length > 0) 1928 length = simple_read_from_buffer(buf, count, ppos, p, length); 1929 kfree(p); 1930 return length; 1931 } 1932 1933 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 1934 size_t count, loff_t *ppos) 1935 { 1936 struct inode * inode = file->f_path.dentry->d_inode; 1937 char *page; 1938 ssize_t length; 1939 struct task_struct *task = get_proc_task(inode); 1940 1941 length = -ESRCH; 1942 if (!task) 1943 goto out_no_task; 1944 if (count > PAGE_SIZE) 1945 count = PAGE_SIZE; 1946 1947 /* No partial writes. */ 1948 length = -EINVAL; 1949 if (*ppos != 0) 1950 goto out; 1951 1952 length = -ENOMEM; 1953 page = (char*)__get_free_page(GFP_TEMPORARY); 1954 if (!page) 1955 goto out; 1956 1957 length = -EFAULT; 1958 if (copy_from_user(page, buf, count)) 1959 goto out_free; 1960 1961 length = security_setprocattr(task, 1962 (char*)file->f_path.dentry->d_name.name, 1963 (void*)page, count); 1964 out_free: 1965 free_page((unsigned long) page); 1966 out: 1967 put_task_struct(task); 1968 out_no_task: 1969 return length; 1970 } 1971 1972 static const struct file_operations proc_pid_attr_operations = { 1973 .read = proc_pid_attr_read, 1974 .write = proc_pid_attr_write, 1975 }; 1976 1977 static const struct pid_entry attr_dir_stuff[] = { 1978 REG("current", S_IRUGO|S_IWUGO, pid_attr), 1979 REG("prev", S_IRUGO, pid_attr), 1980 REG("exec", S_IRUGO|S_IWUGO, pid_attr), 1981 REG("fscreate", S_IRUGO|S_IWUGO, pid_attr), 1982 REG("keycreate", S_IRUGO|S_IWUGO, pid_attr), 1983 REG("sockcreate", S_IRUGO|S_IWUGO, pid_attr), 1984 }; 1985 1986 static int proc_attr_dir_readdir(struct file * filp, 1987 void * dirent, filldir_t filldir) 1988 { 1989 return proc_pident_readdir(filp,dirent,filldir, 1990 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 1991 } 1992 1993 static const struct file_operations proc_attr_dir_operations = { 1994 .read = generic_read_dir, 1995 .readdir = proc_attr_dir_readdir, 1996 }; 1997 1998 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 1999 struct dentry *dentry, struct nameidata *nd) 2000 { 2001 return proc_pident_lookup(dir, dentry, 2002 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 2003 } 2004 2005 static const struct inode_operations proc_attr_dir_inode_operations = { 2006 .lookup = proc_attr_dir_lookup, 2007 .getattr = pid_getattr, 2008 .setattr = proc_setattr, 2009 }; 2010 2011 #endif 2012 2013 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2014 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 2015 size_t count, loff_t *ppos) 2016 { 2017 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 2018 struct mm_struct *mm; 2019 char buffer[PROC_NUMBUF]; 2020 size_t len; 2021 int ret; 2022 2023 if (!task) 2024 return -ESRCH; 2025 2026 ret = 0; 2027 mm = get_task_mm(task); 2028 if (mm) { 2029 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 2030 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 2031 MMF_DUMP_FILTER_SHIFT)); 2032 mmput(mm); 2033 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 2034 } 2035 2036 put_task_struct(task); 2037 2038 return ret; 2039 } 2040 2041 static ssize_t proc_coredump_filter_write(struct file *file, 2042 const char __user *buf, 2043 size_t count, 2044 loff_t *ppos) 2045 { 2046 struct task_struct *task; 2047 struct mm_struct *mm; 2048 char buffer[PROC_NUMBUF], *end; 2049 unsigned int val; 2050 int ret; 2051 int i; 2052 unsigned long mask; 2053 2054 ret = -EFAULT; 2055 memset(buffer, 0, sizeof(buffer)); 2056 if (count > sizeof(buffer) - 1) 2057 count = sizeof(buffer) - 1; 2058 if (copy_from_user(buffer, buf, count)) 2059 goto out_no_task; 2060 2061 ret = -EINVAL; 2062 val = (unsigned int)simple_strtoul(buffer, &end, 0); 2063 if (*end == '\n') 2064 end++; 2065 if (end - buffer == 0) 2066 goto out_no_task; 2067 2068 ret = -ESRCH; 2069 task = get_proc_task(file->f_dentry->d_inode); 2070 if (!task) 2071 goto out_no_task; 2072 2073 ret = end - buffer; 2074 mm = get_task_mm(task); 2075 if (!mm) 2076 goto out_no_mm; 2077 2078 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 2079 if (val & mask) 2080 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2081 else 2082 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 2083 } 2084 2085 mmput(mm); 2086 out_no_mm: 2087 put_task_struct(task); 2088 out_no_task: 2089 return ret; 2090 } 2091 2092 static const struct file_operations proc_coredump_filter_operations = { 2093 .read = proc_coredump_filter_read, 2094 .write = proc_coredump_filter_write, 2095 }; 2096 #endif 2097 2098 /* 2099 * /proc/self: 2100 */ 2101 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 2102 int buflen) 2103 { 2104 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2105 pid_t tgid = task_tgid_nr_ns(current, ns); 2106 char tmp[PROC_NUMBUF]; 2107 if (!tgid) 2108 return -ENOENT; 2109 sprintf(tmp, "%d", tgid); 2110 return vfs_readlink(dentry,buffer,buflen,tmp); 2111 } 2112 2113 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 2114 { 2115 struct pid_namespace *ns = dentry->d_sb->s_fs_info; 2116 pid_t tgid = task_tgid_nr_ns(current, ns); 2117 char tmp[PROC_NUMBUF]; 2118 if (!tgid) 2119 return ERR_PTR(-ENOENT); 2120 sprintf(tmp, "%d", task_tgid_nr_ns(current, ns)); 2121 return ERR_PTR(vfs_follow_link(nd,tmp)); 2122 } 2123 2124 static const struct inode_operations proc_self_inode_operations = { 2125 .readlink = proc_self_readlink, 2126 .follow_link = proc_self_follow_link, 2127 }; 2128 2129 /* 2130 * proc base 2131 * 2132 * These are the directory entries in the root directory of /proc 2133 * that properly belong to the /proc filesystem, as they describe 2134 * describe something that is process related. 2135 */ 2136 static const struct pid_entry proc_base_stuff[] = { 2137 NOD("self", S_IFLNK|S_IRWXUGO, 2138 &proc_self_inode_operations, NULL, {}), 2139 }; 2140 2141 /* 2142 * Exceptional case: normally we are not allowed to unhash a busy 2143 * directory. In this case, however, we can do it - no aliasing problems 2144 * due to the way we treat inodes. 2145 */ 2146 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) 2147 { 2148 struct inode *inode = dentry->d_inode; 2149 struct task_struct *task = get_proc_task(inode); 2150 if (task) { 2151 put_task_struct(task); 2152 return 1; 2153 } 2154 d_drop(dentry); 2155 return 0; 2156 } 2157 2158 static struct dentry_operations proc_base_dentry_operations = 2159 { 2160 .d_revalidate = proc_base_revalidate, 2161 .d_delete = pid_delete_dentry, 2162 }; 2163 2164 static struct dentry *proc_base_instantiate(struct inode *dir, 2165 struct dentry *dentry, struct task_struct *task, const void *ptr) 2166 { 2167 const struct pid_entry *p = ptr; 2168 struct inode *inode; 2169 struct proc_inode *ei; 2170 struct dentry *error = ERR_PTR(-EINVAL); 2171 2172 /* Allocate the inode */ 2173 error = ERR_PTR(-ENOMEM); 2174 inode = new_inode(dir->i_sb); 2175 if (!inode) 2176 goto out; 2177 2178 /* Initialize the inode */ 2179 ei = PROC_I(inode); 2180 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2181 2182 /* 2183 * grab the reference to the task. 2184 */ 2185 ei->pid = get_task_pid(task, PIDTYPE_PID); 2186 if (!ei->pid) 2187 goto out_iput; 2188 2189 inode->i_uid = 0; 2190 inode->i_gid = 0; 2191 inode->i_mode = p->mode; 2192 if (S_ISDIR(inode->i_mode)) 2193 inode->i_nlink = 2; 2194 if (S_ISLNK(inode->i_mode)) 2195 inode->i_size = 64; 2196 if (p->iop) 2197 inode->i_op = p->iop; 2198 if (p->fop) 2199 inode->i_fop = p->fop; 2200 ei->op = p->op; 2201 dentry->d_op = &proc_base_dentry_operations; 2202 d_add(dentry, inode); 2203 error = NULL; 2204 out: 2205 return error; 2206 out_iput: 2207 iput(inode); 2208 goto out; 2209 } 2210 2211 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 2212 { 2213 struct dentry *error; 2214 struct task_struct *task = get_proc_task(dir); 2215 const struct pid_entry *p, *last; 2216 2217 error = ERR_PTR(-ENOENT); 2218 2219 if (!task) 2220 goto out_no_task; 2221 2222 /* Lookup the directory entry */ 2223 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 2224 for (p = proc_base_stuff; p <= last; p++) { 2225 if (p->len != dentry->d_name.len) 2226 continue; 2227 if (!memcmp(dentry->d_name.name, p->name, p->len)) 2228 break; 2229 } 2230 if (p > last) 2231 goto out; 2232 2233 error = proc_base_instantiate(dir, dentry, task, p); 2234 2235 out: 2236 put_task_struct(task); 2237 out_no_task: 2238 return error; 2239 } 2240 2241 static int proc_base_fill_cache(struct file *filp, void *dirent, 2242 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2243 { 2244 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2245 proc_base_instantiate, task, p); 2246 } 2247 2248 #ifdef CONFIG_TASK_IO_ACCOUNTING 2249 static int proc_pid_io_accounting(struct task_struct *task, char *buffer) 2250 { 2251 return sprintf(buffer, 2252 #ifdef CONFIG_TASK_XACCT 2253 "rchar: %llu\n" 2254 "wchar: %llu\n" 2255 "syscr: %llu\n" 2256 "syscw: %llu\n" 2257 #endif 2258 "read_bytes: %llu\n" 2259 "write_bytes: %llu\n" 2260 "cancelled_write_bytes: %llu\n", 2261 #ifdef CONFIG_TASK_XACCT 2262 (unsigned long long)task->rchar, 2263 (unsigned long long)task->wchar, 2264 (unsigned long long)task->syscr, 2265 (unsigned long long)task->syscw, 2266 #endif 2267 (unsigned long long)task->ioac.read_bytes, 2268 (unsigned long long)task->ioac.write_bytes, 2269 (unsigned long long)task->ioac.cancelled_write_bytes); 2270 } 2271 #endif 2272 2273 /* 2274 * Thread groups 2275 */ 2276 static const struct file_operations proc_task_operations; 2277 static const struct inode_operations proc_task_inode_operations; 2278 2279 static const struct pid_entry tgid_base_stuff[] = { 2280 DIR("task", S_IRUGO|S_IXUGO, task), 2281 DIR("fd", S_IRUSR|S_IXUSR, fd), 2282 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), 2283 REG("environ", S_IRUSR, environ), 2284 INF("auxv", S_IRUSR, pid_auxv), 2285 ONE("status", S_IRUGO, pid_status), 2286 INF("limits", S_IRUSR, pid_limits), 2287 #ifdef CONFIG_SCHED_DEBUG 2288 REG("sched", S_IRUGO|S_IWUSR, pid_sched), 2289 #endif 2290 INF("cmdline", S_IRUGO, pid_cmdline), 2291 ONE("stat", S_IRUGO, tgid_stat), 2292 ONE("statm", S_IRUGO, pid_statm), 2293 REG("maps", S_IRUGO, maps), 2294 #ifdef CONFIG_NUMA 2295 REG("numa_maps", S_IRUGO, numa_maps), 2296 #endif 2297 REG("mem", S_IRUSR|S_IWUSR, mem), 2298 LNK("cwd", cwd), 2299 LNK("root", root), 2300 LNK("exe", exe), 2301 REG("mounts", S_IRUGO, mounts), 2302 REG("mountstats", S_IRUSR, mountstats), 2303 #ifdef CONFIG_PROC_PAGE_MONITOR 2304 REG("clear_refs", S_IWUSR, clear_refs), 2305 REG("smaps", S_IRUGO, smaps), 2306 REG("pagemap", S_IRUSR, pagemap), 2307 #endif 2308 #ifdef CONFIG_SECURITY 2309 DIR("attr", S_IRUGO|S_IXUGO, attr_dir), 2310 #endif 2311 #ifdef CONFIG_KALLSYMS 2312 INF("wchan", S_IRUGO, pid_wchan), 2313 #endif 2314 #ifdef CONFIG_SCHEDSTATS 2315 INF("schedstat", S_IRUGO, pid_schedstat), 2316 #endif 2317 #ifdef CONFIG_LATENCYTOP 2318 REG("latency", S_IRUGO, lstats), 2319 #endif 2320 #ifdef CONFIG_PROC_PID_CPUSET 2321 REG("cpuset", S_IRUGO, cpuset), 2322 #endif 2323 #ifdef CONFIG_CGROUPS 2324 REG("cgroup", S_IRUGO, cgroup), 2325 #endif 2326 INF("oom_score", S_IRUGO, oom_score), 2327 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust), 2328 #ifdef CONFIG_AUDITSYSCALL 2329 REG("loginuid", S_IWUSR|S_IRUGO, loginuid), 2330 #endif 2331 #ifdef CONFIG_FAULT_INJECTION 2332 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject), 2333 #endif 2334 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2335 REG("coredump_filter", S_IRUGO|S_IWUSR, coredump_filter), 2336 #endif 2337 #ifdef CONFIG_TASK_IO_ACCOUNTING 2338 INF("io", S_IRUGO, pid_io_accounting), 2339 #endif 2340 }; 2341 2342 static int proc_tgid_base_readdir(struct file * filp, 2343 void * dirent, filldir_t filldir) 2344 { 2345 return proc_pident_readdir(filp,dirent,filldir, 2346 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2347 } 2348 2349 static const struct file_operations proc_tgid_base_operations = { 2350 .read = generic_read_dir, 2351 .readdir = proc_tgid_base_readdir, 2352 }; 2353 2354 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2355 return proc_pident_lookup(dir, dentry, 2356 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2357 } 2358 2359 static const struct inode_operations proc_tgid_base_inode_operations = { 2360 .lookup = proc_tgid_base_lookup, 2361 .getattr = pid_getattr, 2362 .setattr = proc_setattr, 2363 }; 2364 2365 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) 2366 { 2367 struct dentry *dentry, *leader, *dir; 2368 char buf[PROC_NUMBUF]; 2369 struct qstr name; 2370 2371 name.name = buf; 2372 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2373 dentry = d_hash_and_lookup(mnt->mnt_root, &name); 2374 if (dentry) { 2375 if (!(current->flags & PF_EXITING)) 2376 shrink_dcache_parent(dentry); 2377 d_drop(dentry); 2378 dput(dentry); 2379 } 2380 2381 if (tgid == 0) 2382 goto out; 2383 2384 name.name = buf; 2385 name.len = snprintf(buf, sizeof(buf), "%d", tgid); 2386 leader = d_hash_and_lookup(mnt->mnt_root, &name); 2387 if (!leader) 2388 goto out; 2389 2390 name.name = "task"; 2391 name.len = strlen(name.name); 2392 dir = d_hash_and_lookup(leader, &name); 2393 if (!dir) 2394 goto out_put_leader; 2395 2396 name.name = buf; 2397 name.len = snprintf(buf, sizeof(buf), "%d", pid); 2398 dentry = d_hash_and_lookup(dir, &name); 2399 if (dentry) { 2400 shrink_dcache_parent(dentry); 2401 d_drop(dentry); 2402 dput(dentry); 2403 } 2404 2405 dput(dir); 2406 out_put_leader: 2407 dput(leader); 2408 out: 2409 return; 2410 } 2411 2412 /** 2413 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2414 * @task: task that should be flushed. 2415 * 2416 * When flushing dentries from proc, one needs to flush them from global 2417 * proc (proc_mnt) and from all the namespaces' procs this task was seen 2418 * in. This call is supposed to do all of this job. 2419 * 2420 * Looks in the dcache for 2421 * /proc/@pid 2422 * /proc/@tgid/task/@pid 2423 * if either directory is present flushes it and all of it'ts children 2424 * from the dcache. 2425 * 2426 * It is safe and reasonable to cache /proc entries for a task until 2427 * that task exits. After that they just clog up the dcache with 2428 * useless entries, possibly causing useful dcache entries to be 2429 * flushed instead. This routine is proved to flush those useless 2430 * dcache entries at process exit time. 2431 * 2432 * NOTE: This routine is just an optimization so it does not guarantee 2433 * that no dcache entries will exist at process exit time it 2434 * just makes it very unlikely that any will persist. 2435 */ 2436 2437 void proc_flush_task(struct task_struct *task) 2438 { 2439 int i; 2440 struct pid *pid, *tgid = NULL; 2441 struct upid *upid; 2442 2443 pid = task_pid(task); 2444 if (thread_group_leader(task)) 2445 tgid = task_tgid(task); 2446 2447 for (i = 0; i <= pid->level; i++) { 2448 upid = &pid->numbers[i]; 2449 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr, 2450 tgid ? tgid->numbers[i].nr : 0); 2451 } 2452 2453 upid = &pid->numbers[pid->level]; 2454 if (upid->nr == 1) 2455 pid_ns_release_proc(upid->ns); 2456 } 2457 2458 static struct dentry *proc_pid_instantiate(struct inode *dir, 2459 struct dentry * dentry, 2460 struct task_struct *task, const void *ptr) 2461 { 2462 struct dentry *error = ERR_PTR(-ENOENT); 2463 struct inode *inode; 2464 2465 inode = proc_pid_make_inode(dir->i_sb, task); 2466 if (!inode) 2467 goto out; 2468 2469 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2470 inode->i_op = &proc_tgid_base_inode_operations; 2471 inode->i_fop = &proc_tgid_base_operations; 2472 inode->i_flags|=S_IMMUTABLE; 2473 inode->i_nlink = 5; 2474 #ifdef CONFIG_SECURITY 2475 inode->i_nlink += 1; 2476 #endif 2477 2478 dentry->d_op = &pid_dentry_operations; 2479 2480 d_add(dentry, inode); 2481 /* Close the race of the process dying before we return the dentry */ 2482 if (pid_revalidate(dentry, NULL)) 2483 error = NULL; 2484 out: 2485 return error; 2486 } 2487 2488 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2489 { 2490 struct dentry *result = ERR_PTR(-ENOENT); 2491 struct task_struct *task; 2492 unsigned tgid; 2493 struct pid_namespace *ns; 2494 2495 result = proc_base_lookup(dir, dentry); 2496 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 2497 goto out; 2498 2499 tgid = name_to_int(dentry); 2500 if (tgid == ~0U) 2501 goto out; 2502 2503 ns = dentry->d_sb->s_fs_info; 2504 rcu_read_lock(); 2505 task = find_task_by_pid_ns(tgid, ns); 2506 if (task) 2507 get_task_struct(task); 2508 rcu_read_unlock(); 2509 if (!task) 2510 goto out; 2511 2512 result = proc_pid_instantiate(dir, dentry, task, NULL); 2513 put_task_struct(task); 2514 out: 2515 return result; 2516 } 2517 2518 /* 2519 * Find the first task with tgid >= tgid 2520 * 2521 */ 2522 struct tgid_iter { 2523 unsigned int tgid; 2524 struct task_struct *task; 2525 }; 2526 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter) 2527 { 2528 struct pid *pid; 2529 2530 if (iter.task) 2531 put_task_struct(iter.task); 2532 rcu_read_lock(); 2533 retry: 2534 iter.task = NULL; 2535 pid = find_ge_pid(iter.tgid, ns); 2536 if (pid) { 2537 iter.tgid = pid_nr_ns(pid, ns); 2538 iter.task = pid_task(pid, PIDTYPE_PID); 2539 /* What we to know is if the pid we have find is the 2540 * pid of a thread_group_leader. Testing for task 2541 * being a thread_group_leader is the obvious thing 2542 * todo but there is a window when it fails, due to 2543 * the pid transfer logic in de_thread. 2544 * 2545 * So we perform the straight forward test of seeing 2546 * if the pid we have found is the pid of a thread 2547 * group leader, and don't worry if the task we have 2548 * found doesn't happen to be a thread group leader. 2549 * As we don't care in the case of readdir. 2550 */ 2551 if (!iter.task || !has_group_leader_pid(iter.task)) { 2552 iter.tgid += 1; 2553 goto retry; 2554 } 2555 get_task_struct(iter.task); 2556 } 2557 rcu_read_unlock(); 2558 return iter; 2559 } 2560 2561 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 2562 2563 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2564 struct tgid_iter iter) 2565 { 2566 char name[PROC_NUMBUF]; 2567 int len = snprintf(name, sizeof(name), "%d", iter.tgid); 2568 return proc_fill_cache(filp, dirent, filldir, name, len, 2569 proc_pid_instantiate, iter.task, NULL); 2570 } 2571 2572 /* for the /proc/ directory itself, after non-process stuff has been done */ 2573 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 2574 { 2575 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; 2576 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode); 2577 struct tgid_iter iter; 2578 struct pid_namespace *ns; 2579 2580 if (!reaper) 2581 goto out_no_task; 2582 2583 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 2584 const struct pid_entry *p = &proc_base_stuff[nr]; 2585 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 2586 goto out; 2587 } 2588 2589 ns = filp->f_dentry->d_sb->s_fs_info; 2590 iter.task = NULL; 2591 iter.tgid = filp->f_pos - TGID_OFFSET; 2592 for (iter = next_tgid(ns, iter); 2593 iter.task; 2594 iter.tgid += 1, iter = next_tgid(ns, iter)) { 2595 filp->f_pos = iter.tgid + TGID_OFFSET; 2596 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) { 2597 put_task_struct(iter.task); 2598 goto out; 2599 } 2600 } 2601 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 2602 out: 2603 put_task_struct(reaper); 2604 out_no_task: 2605 return 0; 2606 } 2607 2608 /* 2609 * Tasks 2610 */ 2611 static const struct pid_entry tid_base_stuff[] = { 2612 DIR("fd", S_IRUSR|S_IXUSR, fd), 2613 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), 2614 REG("environ", S_IRUSR, environ), 2615 INF("auxv", S_IRUSR, pid_auxv), 2616 ONE("status", S_IRUGO, pid_status), 2617 INF("limits", S_IRUSR, pid_limits), 2618 #ifdef CONFIG_SCHED_DEBUG 2619 REG("sched", S_IRUGO|S_IWUSR, pid_sched), 2620 #endif 2621 INF("cmdline", S_IRUGO, pid_cmdline), 2622 ONE("stat", S_IRUGO, tid_stat), 2623 ONE("statm", S_IRUGO, pid_statm), 2624 REG("maps", S_IRUGO, maps), 2625 #ifdef CONFIG_NUMA 2626 REG("numa_maps", S_IRUGO, numa_maps), 2627 #endif 2628 REG("mem", S_IRUSR|S_IWUSR, mem), 2629 LNK("cwd", cwd), 2630 LNK("root", root), 2631 LNK("exe", exe), 2632 REG("mounts", S_IRUGO, mounts), 2633 #ifdef CONFIG_PROC_PAGE_MONITOR 2634 REG("clear_refs", S_IWUSR, clear_refs), 2635 REG("smaps", S_IRUGO, smaps), 2636 REG("pagemap", S_IRUSR, pagemap), 2637 #endif 2638 #ifdef CONFIG_SECURITY 2639 DIR("attr", S_IRUGO|S_IXUGO, attr_dir), 2640 #endif 2641 #ifdef CONFIG_KALLSYMS 2642 INF("wchan", S_IRUGO, pid_wchan), 2643 #endif 2644 #ifdef CONFIG_SCHEDSTATS 2645 INF("schedstat", S_IRUGO, pid_schedstat), 2646 #endif 2647 #ifdef CONFIG_LATENCYTOP 2648 REG("latency", S_IRUGO, lstats), 2649 #endif 2650 #ifdef CONFIG_PROC_PID_CPUSET 2651 REG("cpuset", S_IRUGO, cpuset), 2652 #endif 2653 #ifdef CONFIG_CGROUPS 2654 REG("cgroup", S_IRUGO, cgroup), 2655 #endif 2656 INF("oom_score", S_IRUGO, oom_score), 2657 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust), 2658 #ifdef CONFIG_AUDITSYSCALL 2659 REG("loginuid", S_IWUSR|S_IRUGO, loginuid), 2660 #endif 2661 #ifdef CONFIG_FAULT_INJECTION 2662 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject), 2663 #endif 2664 }; 2665 2666 static int proc_tid_base_readdir(struct file * filp, 2667 void * dirent, filldir_t filldir) 2668 { 2669 return proc_pident_readdir(filp,dirent,filldir, 2670 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 2671 } 2672 2673 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2674 return proc_pident_lookup(dir, dentry, 2675 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 2676 } 2677 2678 static const struct file_operations proc_tid_base_operations = { 2679 .read = generic_read_dir, 2680 .readdir = proc_tid_base_readdir, 2681 }; 2682 2683 static const struct inode_operations proc_tid_base_inode_operations = { 2684 .lookup = proc_tid_base_lookup, 2685 .getattr = pid_getattr, 2686 .setattr = proc_setattr, 2687 }; 2688 2689 static struct dentry *proc_task_instantiate(struct inode *dir, 2690 struct dentry *dentry, struct task_struct *task, const void *ptr) 2691 { 2692 struct dentry *error = ERR_PTR(-ENOENT); 2693 struct inode *inode; 2694 inode = proc_pid_make_inode(dir->i_sb, task); 2695 2696 if (!inode) 2697 goto out; 2698 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2699 inode->i_op = &proc_tid_base_inode_operations; 2700 inode->i_fop = &proc_tid_base_operations; 2701 inode->i_flags|=S_IMMUTABLE; 2702 inode->i_nlink = 4; 2703 #ifdef CONFIG_SECURITY 2704 inode->i_nlink += 1; 2705 #endif 2706 2707 dentry->d_op = &pid_dentry_operations; 2708 2709 d_add(dentry, inode); 2710 /* Close the race of the process dying before we return the dentry */ 2711 if (pid_revalidate(dentry, NULL)) 2712 error = NULL; 2713 out: 2714 return error; 2715 } 2716 2717 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2718 { 2719 struct dentry *result = ERR_PTR(-ENOENT); 2720 struct task_struct *task; 2721 struct task_struct *leader = get_proc_task(dir); 2722 unsigned tid; 2723 struct pid_namespace *ns; 2724 2725 if (!leader) 2726 goto out_no_task; 2727 2728 tid = name_to_int(dentry); 2729 if (tid == ~0U) 2730 goto out; 2731 2732 ns = dentry->d_sb->s_fs_info; 2733 rcu_read_lock(); 2734 task = find_task_by_pid_ns(tid, ns); 2735 if (task) 2736 get_task_struct(task); 2737 rcu_read_unlock(); 2738 if (!task) 2739 goto out; 2740 if (!same_thread_group(leader, task)) 2741 goto out_drop_task; 2742 2743 result = proc_task_instantiate(dir, dentry, task, NULL); 2744 out_drop_task: 2745 put_task_struct(task); 2746 out: 2747 put_task_struct(leader); 2748 out_no_task: 2749 return result; 2750 } 2751 2752 /* 2753 * Find the first tid of a thread group to return to user space. 2754 * 2755 * Usually this is just the thread group leader, but if the users 2756 * buffer was too small or there was a seek into the middle of the 2757 * directory we have more work todo. 2758 * 2759 * In the case of a short read we start with find_task_by_pid. 2760 * 2761 * In the case of a seek we start with the leader and walk nr 2762 * threads past it. 2763 */ 2764 static struct task_struct *first_tid(struct task_struct *leader, 2765 int tid, int nr, struct pid_namespace *ns) 2766 { 2767 struct task_struct *pos; 2768 2769 rcu_read_lock(); 2770 /* Attempt to start with the pid of a thread */ 2771 if (tid && (nr > 0)) { 2772 pos = find_task_by_pid_ns(tid, ns); 2773 if (pos && (pos->group_leader == leader)) 2774 goto found; 2775 } 2776 2777 /* If nr exceeds the number of threads there is nothing todo */ 2778 pos = NULL; 2779 if (nr && nr >= get_nr_threads(leader)) 2780 goto out; 2781 2782 /* If we haven't found our starting place yet start 2783 * with the leader and walk nr threads forward. 2784 */ 2785 for (pos = leader; nr > 0; --nr) { 2786 pos = next_thread(pos); 2787 if (pos == leader) { 2788 pos = NULL; 2789 goto out; 2790 } 2791 } 2792 found: 2793 get_task_struct(pos); 2794 out: 2795 rcu_read_unlock(); 2796 return pos; 2797 } 2798 2799 /* 2800 * Find the next thread in the thread list. 2801 * Return NULL if there is an error or no next thread. 2802 * 2803 * The reference to the input task_struct is released. 2804 */ 2805 static struct task_struct *next_tid(struct task_struct *start) 2806 { 2807 struct task_struct *pos = NULL; 2808 rcu_read_lock(); 2809 if (pid_alive(start)) { 2810 pos = next_thread(start); 2811 if (thread_group_leader(pos)) 2812 pos = NULL; 2813 else 2814 get_task_struct(pos); 2815 } 2816 rcu_read_unlock(); 2817 put_task_struct(start); 2818 return pos; 2819 } 2820 2821 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2822 struct task_struct *task, int tid) 2823 { 2824 char name[PROC_NUMBUF]; 2825 int len = snprintf(name, sizeof(name), "%d", tid); 2826 return proc_fill_cache(filp, dirent, filldir, name, len, 2827 proc_task_instantiate, task, NULL); 2828 } 2829 2830 /* for the /proc/TGID/task/ directories */ 2831 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 2832 { 2833 struct dentry *dentry = filp->f_path.dentry; 2834 struct inode *inode = dentry->d_inode; 2835 struct task_struct *leader = NULL; 2836 struct task_struct *task; 2837 int retval = -ENOENT; 2838 ino_t ino; 2839 int tid; 2840 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */ 2841 struct pid_namespace *ns; 2842 2843 task = get_proc_task(inode); 2844 if (!task) 2845 goto out_no_task; 2846 rcu_read_lock(); 2847 if (pid_alive(task)) { 2848 leader = task->group_leader; 2849 get_task_struct(leader); 2850 } 2851 rcu_read_unlock(); 2852 put_task_struct(task); 2853 if (!leader) 2854 goto out_no_task; 2855 retval = 0; 2856 2857 switch (pos) { 2858 case 0: 2859 ino = inode->i_ino; 2860 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0) 2861 goto out; 2862 pos++; 2863 /* fall through */ 2864 case 1: 2865 ino = parent_ino(dentry); 2866 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0) 2867 goto out; 2868 pos++; 2869 /* fall through */ 2870 } 2871 2872 /* f_version caches the tgid value that the last readdir call couldn't 2873 * return. lseek aka telldir automagically resets f_version to 0. 2874 */ 2875 ns = filp->f_dentry->d_sb->s_fs_info; 2876 tid = (int)filp->f_version; 2877 filp->f_version = 0; 2878 for (task = first_tid(leader, tid, pos - 2, ns); 2879 task; 2880 task = next_tid(task), pos++) { 2881 tid = task_pid_nr_ns(task, ns); 2882 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 2883 /* returning this tgid failed, save it as the first 2884 * pid for the next readir call */ 2885 filp->f_version = (u64)tid; 2886 put_task_struct(task); 2887 break; 2888 } 2889 } 2890 out: 2891 filp->f_pos = pos; 2892 put_task_struct(leader); 2893 out_no_task: 2894 return retval; 2895 } 2896 2897 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 2898 { 2899 struct inode *inode = dentry->d_inode; 2900 struct task_struct *p = get_proc_task(inode); 2901 generic_fillattr(inode, stat); 2902 2903 if (p) { 2904 rcu_read_lock(); 2905 stat->nlink += get_nr_threads(p); 2906 rcu_read_unlock(); 2907 put_task_struct(p); 2908 } 2909 2910 return 0; 2911 } 2912 2913 static const struct inode_operations proc_task_inode_operations = { 2914 .lookup = proc_task_lookup, 2915 .getattr = proc_task_getattr, 2916 .setattr = proc_setattr, 2917 }; 2918 2919 static const struct file_operations proc_task_operations = { 2920 .read = generic_read_dir, 2921 .readdir = proc_task_readdir, 2922 }; 2923