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