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