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.pcount); 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_TEMPORARY))) 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_TEMPORARY); 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_TEMPORARY); 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_TEMPORARY); 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_TEMPORARY); 958 char *path; 959 int len; 960 961 if (!tmp) 962 return -ENOMEM; 963 964 inode = dentry->d_inode; 965 path = d_path(dentry, mnt, tmp, PAGE_SIZE); 966 len = PTR_ERR(path); 967 if (IS_ERR(path)) 968 goto out; 969 len = tmp + PAGE_SIZE - 1 - path; 970 971 if (len > buflen) 972 len = buflen; 973 if (copy_to_user(buffer, path, len)) 974 len = -EFAULT; 975 out: 976 free_page((unsigned long)tmp); 977 return len; 978 } 979 980 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 981 { 982 int error = -EACCES; 983 struct inode *inode = dentry->d_inode; 984 struct dentry *de; 985 struct vfsmount *mnt = NULL; 986 987 /* Are we allowed to snoop on the tasks file descriptors? */ 988 if (!proc_fd_access_allowed(inode)) 989 goto out; 990 991 error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt); 992 if (error) 993 goto out; 994 995 error = do_proc_readlink(de, mnt, buffer, buflen); 996 dput(de); 997 mntput(mnt); 998 out: 999 return error; 1000 } 1001 1002 static const struct inode_operations proc_pid_link_inode_operations = { 1003 .readlink = proc_pid_readlink, 1004 .follow_link = proc_pid_follow_link, 1005 .setattr = proc_setattr, 1006 }; 1007 1008 1009 /* building an inode */ 1010 1011 static int task_dumpable(struct task_struct *task) 1012 { 1013 int dumpable = 0; 1014 struct mm_struct *mm; 1015 1016 task_lock(task); 1017 mm = task->mm; 1018 if (mm) 1019 dumpable = get_dumpable(mm); 1020 task_unlock(task); 1021 if(dumpable == 1) 1022 return 1; 1023 return 0; 1024 } 1025 1026 1027 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1028 { 1029 struct inode * inode; 1030 struct proc_inode *ei; 1031 1032 /* We need a new inode */ 1033 1034 inode = new_inode(sb); 1035 if (!inode) 1036 goto out; 1037 1038 /* Common stuff */ 1039 ei = PROC_I(inode); 1040 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1041 inode->i_op = &proc_def_inode_operations; 1042 1043 /* 1044 * grab the reference to task. 1045 */ 1046 ei->pid = get_task_pid(task, PIDTYPE_PID); 1047 if (!ei->pid) 1048 goto out_unlock; 1049 1050 inode->i_uid = 0; 1051 inode->i_gid = 0; 1052 if (task_dumpable(task)) { 1053 inode->i_uid = task->euid; 1054 inode->i_gid = task->egid; 1055 } 1056 security_task_to_inode(task, inode); 1057 1058 out: 1059 return inode; 1060 1061 out_unlock: 1062 iput(inode); 1063 return NULL; 1064 } 1065 1066 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1067 { 1068 struct inode *inode = dentry->d_inode; 1069 struct task_struct *task; 1070 generic_fillattr(inode, stat); 1071 1072 rcu_read_lock(); 1073 stat->uid = 0; 1074 stat->gid = 0; 1075 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1076 if (task) { 1077 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1078 task_dumpable(task)) { 1079 stat->uid = task->euid; 1080 stat->gid = task->egid; 1081 } 1082 } 1083 rcu_read_unlock(); 1084 return 0; 1085 } 1086 1087 /* dentry stuff */ 1088 1089 /* 1090 * Exceptional case: normally we are not allowed to unhash a busy 1091 * directory. In this case, however, we can do it - no aliasing problems 1092 * due to the way we treat inodes. 1093 * 1094 * Rewrite the inode's ownerships here because the owning task may have 1095 * performed a setuid(), etc. 1096 * 1097 * Before the /proc/pid/status file was created the only way to read 1098 * the effective uid of a /process was to stat /proc/pid. Reading 1099 * /proc/pid/status is slow enough that procps and other packages 1100 * kept stating /proc/pid. To keep the rules in /proc simple I have 1101 * made this apply to all per process world readable and executable 1102 * directories. 1103 */ 1104 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1105 { 1106 struct inode *inode = dentry->d_inode; 1107 struct task_struct *task = get_proc_task(inode); 1108 if (task) { 1109 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1110 task_dumpable(task)) { 1111 inode->i_uid = task->euid; 1112 inode->i_gid = task->egid; 1113 } else { 1114 inode->i_uid = 0; 1115 inode->i_gid = 0; 1116 } 1117 inode->i_mode &= ~(S_ISUID | S_ISGID); 1118 security_task_to_inode(task, inode); 1119 put_task_struct(task); 1120 return 1; 1121 } 1122 d_drop(dentry); 1123 return 0; 1124 } 1125 1126 static int pid_delete_dentry(struct dentry * dentry) 1127 { 1128 /* Is the task we represent dead? 1129 * If so, then don't put the dentry on the lru list, 1130 * kill it immediately. 1131 */ 1132 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1133 } 1134 1135 static struct dentry_operations pid_dentry_operations = 1136 { 1137 .d_revalidate = pid_revalidate, 1138 .d_delete = pid_delete_dentry, 1139 }; 1140 1141 /* Lookups */ 1142 1143 typedef struct dentry *instantiate_t(struct inode *, struct dentry *, 1144 struct task_struct *, const void *); 1145 1146 /* 1147 * Fill a directory entry. 1148 * 1149 * If possible create the dcache entry and derive our inode number and 1150 * file type from dcache entry. 1151 * 1152 * Since all of the proc inode numbers are dynamically generated, the inode 1153 * numbers do not exist until the inode is cache. This means creating the 1154 * the dcache entry in readdir is necessary to keep the inode numbers 1155 * reported by readdir in sync with the inode numbers reported 1156 * by stat. 1157 */ 1158 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1159 char *name, int len, 1160 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1161 { 1162 struct dentry *child, *dir = filp->f_path.dentry; 1163 struct inode *inode; 1164 struct qstr qname; 1165 ino_t ino = 0; 1166 unsigned type = DT_UNKNOWN; 1167 1168 qname.name = name; 1169 qname.len = len; 1170 qname.hash = full_name_hash(name, len); 1171 1172 child = d_lookup(dir, &qname); 1173 if (!child) { 1174 struct dentry *new; 1175 new = d_alloc(dir, &qname); 1176 if (new) { 1177 child = instantiate(dir->d_inode, new, task, ptr); 1178 if (child) 1179 dput(new); 1180 else 1181 child = new; 1182 } 1183 } 1184 if (!child || IS_ERR(child) || !child->d_inode) 1185 goto end_instantiate; 1186 inode = child->d_inode; 1187 if (inode) { 1188 ino = inode->i_ino; 1189 type = inode->i_mode >> 12; 1190 } 1191 dput(child); 1192 end_instantiate: 1193 if (!ino) 1194 ino = find_inode_number(dir, &qname); 1195 if (!ino) 1196 ino = 1; 1197 return filldir(dirent, name, len, filp->f_pos, ino, type); 1198 } 1199 1200 static unsigned name_to_int(struct dentry *dentry) 1201 { 1202 const char *name = dentry->d_name.name; 1203 int len = dentry->d_name.len; 1204 unsigned n = 0; 1205 1206 if (len > 1 && *name == '0') 1207 goto out; 1208 while (len-- > 0) { 1209 unsigned c = *name++ - '0'; 1210 if (c > 9) 1211 goto out; 1212 if (n >= (~0U-9)/10) 1213 goto out; 1214 n *= 10; 1215 n += c; 1216 } 1217 return n; 1218 out: 1219 return ~0U; 1220 } 1221 1222 #define PROC_FDINFO_MAX 64 1223 1224 static int proc_fd_info(struct inode *inode, struct dentry **dentry, 1225 struct vfsmount **mnt, char *info) 1226 { 1227 struct task_struct *task = get_proc_task(inode); 1228 struct files_struct *files = NULL; 1229 struct file *file; 1230 int fd = proc_fd(inode); 1231 1232 if (task) { 1233 files = get_files_struct(task); 1234 put_task_struct(task); 1235 } 1236 if (files) { 1237 /* 1238 * We are not taking a ref to the file structure, so we must 1239 * hold ->file_lock. 1240 */ 1241 spin_lock(&files->file_lock); 1242 file = fcheck_files(files, fd); 1243 if (file) { 1244 if (mnt) 1245 *mnt = mntget(file->f_path.mnt); 1246 if (dentry) 1247 *dentry = dget(file->f_path.dentry); 1248 if (info) 1249 snprintf(info, PROC_FDINFO_MAX, 1250 "pos:\t%lli\n" 1251 "flags:\t0%o\n", 1252 (long long) file->f_pos, 1253 file->f_flags); 1254 spin_unlock(&files->file_lock); 1255 put_files_struct(files); 1256 return 0; 1257 } 1258 spin_unlock(&files->file_lock); 1259 put_files_struct(files); 1260 } 1261 return -ENOENT; 1262 } 1263 1264 static int proc_fd_link(struct inode *inode, struct dentry **dentry, 1265 struct vfsmount **mnt) 1266 { 1267 return proc_fd_info(inode, dentry, mnt, NULL); 1268 } 1269 1270 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1271 { 1272 struct inode *inode = dentry->d_inode; 1273 struct task_struct *task = get_proc_task(inode); 1274 int fd = proc_fd(inode); 1275 struct files_struct *files; 1276 1277 if (task) { 1278 files = get_files_struct(task); 1279 if (files) { 1280 rcu_read_lock(); 1281 if (fcheck_files(files, fd)) { 1282 rcu_read_unlock(); 1283 put_files_struct(files); 1284 if (task_dumpable(task)) { 1285 inode->i_uid = task->euid; 1286 inode->i_gid = task->egid; 1287 } else { 1288 inode->i_uid = 0; 1289 inode->i_gid = 0; 1290 } 1291 inode->i_mode &= ~(S_ISUID | S_ISGID); 1292 security_task_to_inode(task, inode); 1293 put_task_struct(task); 1294 return 1; 1295 } 1296 rcu_read_unlock(); 1297 put_files_struct(files); 1298 } 1299 put_task_struct(task); 1300 } 1301 d_drop(dentry); 1302 return 0; 1303 } 1304 1305 static struct dentry_operations tid_fd_dentry_operations = 1306 { 1307 .d_revalidate = tid_fd_revalidate, 1308 .d_delete = pid_delete_dentry, 1309 }; 1310 1311 static struct dentry *proc_fd_instantiate(struct inode *dir, 1312 struct dentry *dentry, struct task_struct *task, const void *ptr) 1313 { 1314 unsigned fd = *(const unsigned *)ptr; 1315 struct file *file; 1316 struct files_struct *files; 1317 struct inode *inode; 1318 struct proc_inode *ei; 1319 struct dentry *error = ERR_PTR(-ENOENT); 1320 1321 inode = proc_pid_make_inode(dir->i_sb, task); 1322 if (!inode) 1323 goto out; 1324 ei = PROC_I(inode); 1325 ei->fd = fd; 1326 files = get_files_struct(task); 1327 if (!files) 1328 goto out_iput; 1329 inode->i_mode = S_IFLNK; 1330 1331 /* 1332 * We are not taking a ref to the file structure, so we must 1333 * hold ->file_lock. 1334 */ 1335 spin_lock(&files->file_lock); 1336 file = fcheck_files(files, fd); 1337 if (!file) 1338 goto out_unlock; 1339 if (file->f_mode & 1) 1340 inode->i_mode |= S_IRUSR | S_IXUSR; 1341 if (file->f_mode & 2) 1342 inode->i_mode |= S_IWUSR | S_IXUSR; 1343 spin_unlock(&files->file_lock); 1344 put_files_struct(files); 1345 1346 inode->i_op = &proc_pid_link_inode_operations; 1347 inode->i_size = 64; 1348 ei->op.proc_get_link = proc_fd_link; 1349 dentry->d_op = &tid_fd_dentry_operations; 1350 d_add(dentry, inode); 1351 /* Close the race of the process dying before we return the dentry */ 1352 if (tid_fd_revalidate(dentry, NULL)) 1353 error = NULL; 1354 1355 out: 1356 return error; 1357 out_unlock: 1358 spin_unlock(&files->file_lock); 1359 put_files_struct(files); 1360 out_iput: 1361 iput(inode); 1362 goto out; 1363 } 1364 1365 static struct dentry *proc_lookupfd_common(struct inode *dir, 1366 struct dentry *dentry, 1367 instantiate_t instantiate) 1368 { 1369 struct task_struct *task = get_proc_task(dir); 1370 unsigned fd = name_to_int(dentry); 1371 struct dentry *result = ERR_PTR(-ENOENT); 1372 1373 if (!task) 1374 goto out_no_task; 1375 if (fd == ~0U) 1376 goto out; 1377 1378 result = instantiate(dir, dentry, task, &fd); 1379 out: 1380 put_task_struct(task); 1381 out_no_task: 1382 return result; 1383 } 1384 1385 static int proc_readfd_common(struct file * filp, void * dirent, 1386 filldir_t filldir, instantiate_t instantiate) 1387 { 1388 struct dentry *dentry = filp->f_path.dentry; 1389 struct inode *inode = dentry->d_inode; 1390 struct task_struct *p = get_proc_task(inode); 1391 unsigned int fd, tid, ino; 1392 int retval; 1393 struct files_struct * files; 1394 struct fdtable *fdt; 1395 1396 retval = -ENOENT; 1397 if (!p) 1398 goto out_no_task; 1399 retval = 0; 1400 tid = p->pid; 1401 1402 fd = filp->f_pos; 1403 switch (fd) { 1404 case 0: 1405 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 1406 goto out; 1407 filp->f_pos++; 1408 case 1: 1409 ino = parent_ino(dentry); 1410 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 1411 goto out; 1412 filp->f_pos++; 1413 default: 1414 files = get_files_struct(p); 1415 if (!files) 1416 goto out; 1417 rcu_read_lock(); 1418 fdt = files_fdtable(files); 1419 for (fd = filp->f_pos-2; 1420 fd < fdt->max_fds; 1421 fd++, filp->f_pos++) { 1422 char name[PROC_NUMBUF]; 1423 int len; 1424 1425 if (!fcheck_files(files, fd)) 1426 continue; 1427 rcu_read_unlock(); 1428 1429 len = snprintf(name, sizeof(name), "%d", fd); 1430 if (proc_fill_cache(filp, dirent, filldir, 1431 name, len, instantiate, 1432 p, &fd) < 0) { 1433 rcu_read_lock(); 1434 break; 1435 } 1436 rcu_read_lock(); 1437 } 1438 rcu_read_unlock(); 1439 put_files_struct(files); 1440 } 1441 out: 1442 put_task_struct(p); 1443 out_no_task: 1444 return retval; 1445 } 1446 1447 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 1448 struct nameidata *nd) 1449 { 1450 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 1451 } 1452 1453 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 1454 { 1455 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 1456 } 1457 1458 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 1459 size_t len, loff_t *ppos) 1460 { 1461 char tmp[PROC_FDINFO_MAX]; 1462 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, NULL, tmp); 1463 if (!err) 1464 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 1465 return err; 1466 } 1467 1468 static const struct file_operations proc_fdinfo_file_operations = { 1469 .open = nonseekable_open, 1470 .read = proc_fdinfo_read, 1471 }; 1472 1473 static const struct file_operations proc_fd_operations = { 1474 .read = generic_read_dir, 1475 .readdir = proc_readfd, 1476 }; 1477 1478 /* 1479 * /proc/pid/fd needs a special permission handler so that a process can still 1480 * access /proc/self/fd after it has executed a setuid(). 1481 */ 1482 static int proc_fd_permission(struct inode *inode, int mask, 1483 struct nameidata *nd) 1484 { 1485 int rv; 1486 1487 rv = generic_permission(inode, mask, NULL); 1488 if (rv == 0) 1489 return 0; 1490 if (task_pid(current) == proc_pid(inode)) 1491 rv = 0; 1492 return rv; 1493 } 1494 1495 /* 1496 * proc directories can do almost nothing.. 1497 */ 1498 static const struct inode_operations proc_fd_inode_operations = { 1499 .lookup = proc_lookupfd, 1500 .permission = proc_fd_permission, 1501 .setattr = proc_setattr, 1502 }; 1503 1504 static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 1505 struct dentry *dentry, struct task_struct *task, const void *ptr) 1506 { 1507 unsigned fd = *(unsigned *)ptr; 1508 struct inode *inode; 1509 struct proc_inode *ei; 1510 struct dentry *error = ERR_PTR(-ENOENT); 1511 1512 inode = proc_pid_make_inode(dir->i_sb, task); 1513 if (!inode) 1514 goto out; 1515 ei = PROC_I(inode); 1516 ei->fd = fd; 1517 inode->i_mode = S_IFREG | S_IRUSR; 1518 inode->i_fop = &proc_fdinfo_file_operations; 1519 dentry->d_op = &tid_fd_dentry_operations; 1520 d_add(dentry, inode); 1521 /* Close the race of the process dying before we return the dentry */ 1522 if (tid_fd_revalidate(dentry, NULL)) 1523 error = NULL; 1524 1525 out: 1526 return error; 1527 } 1528 1529 static struct dentry *proc_lookupfdinfo(struct inode *dir, 1530 struct dentry *dentry, 1531 struct nameidata *nd) 1532 { 1533 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 1534 } 1535 1536 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 1537 { 1538 return proc_readfd_common(filp, dirent, filldir, 1539 proc_fdinfo_instantiate); 1540 } 1541 1542 static const struct file_operations proc_fdinfo_operations = { 1543 .read = generic_read_dir, 1544 .readdir = proc_readfdinfo, 1545 }; 1546 1547 /* 1548 * proc directories can do almost nothing.. 1549 */ 1550 static const struct inode_operations proc_fdinfo_inode_operations = { 1551 .lookup = proc_lookupfdinfo, 1552 .setattr = proc_setattr, 1553 }; 1554 1555 1556 static struct dentry *proc_pident_instantiate(struct inode *dir, 1557 struct dentry *dentry, struct task_struct *task, const void *ptr) 1558 { 1559 const struct pid_entry *p = ptr; 1560 struct inode *inode; 1561 struct proc_inode *ei; 1562 struct dentry *error = ERR_PTR(-EINVAL); 1563 1564 inode = proc_pid_make_inode(dir->i_sb, task); 1565 if (!inode) 1566 goto out; 1567 1568 ei = PROC_I(inode); 1569 inode->i_mode = p->mode; 1570 if (S_ISDIR(inode->i_mode)) 1571 inode->i_nlink = 2; /* Use getattr to fix if necessary */ 1572 if (p->iop) 1573 inode->i_op = p->iop; 1574 if (p->fop) 1575 inode->i_fop = p->fop; 1576 ei->op = p->op; 1577 dentry->d_op = &pid_dentry_operations; 1578 d_add(dentry, inode); 1579 /* Close the race of the process dying before we return the dentry */ 1580 if (pid_revalidate(dentry, NULL)) 1581 error = NULL; 1582 out: 1583 return error; 1584 } 1585 1586 static struct dentry *proc_pident_lookup(struct inode *dir, 1587 struct dentry *dentry, 1588 const struct pid_entry *ents, 1589 unsigned int nents) 1590 { 1591 struct inode *inode; 1592 struct dentry *error; 1593 struct task_struct *task = get_proc_task(dir); 1594 const struct pid_entry *p, *last; 1595 1596 error = ERR_PTR(-ENOENT); 1597 inode = NULL; 1598 1599 if (!task) 1600 goto out_no_task; 1601 1602 /* 1603 * Yes, it does not scale. And it should not. Don't add 1604 * new entries into /proc/<tgid>/ without very good reasons. 1605 */ 1606 last = &ents[nents - 1]; 1607 for (p = ents; p <= last; p++) { 1608 if (p->len != dentry->d_name.len) 1609 continue; 1610 if (!memcmp(dentry->d_name.name, p->name, p->len)) 1611 break; 1612 } 1613 if (p > last) 1614 goto out; 1615 1616 error = proc_pident_instantiate(dir, dentry, task, p); 1617 out: 1618 put_task_struct(task); 1619 out_no_task: 1620 return error; 1621 } 1622 1623 static int proc_pident_fill_cache(struct file *filp, void *dirent, 1624 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 1625 { 1626 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 1627 proc_pident_instantiate, task, p); 1628 } 1629 1630 static int proc_pident_readdir(struct file *filp, 1631 void *dirent, filldir_t filldir, 1632 const struct pid_entry *ents, unsigned int nents) 1633 { 1634 int i; 1635 int pid; 1636 struct dentry *dentry = filp->f_path.dentry; 1637 struct inode *inode = dentry->d_inode; 1638 struct task_struct *task = get_proc_task(inode); 1639 const struct pid_entry *p, *last; 1640 ino_t ino; 1641 int ret; 1642 1643 ret = -ENOENT; 1644 if (!task) 1645 goto out_no_task; 1646 1647 ret = 0; 1648 pid = task->pid; 1649 i = filp->f_pos; 1650 switch (i) { 1651 case 0: 1652 ino = inode->i_ino; 1653 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 1654 goto out; 1655 i++; 1656 filp->f_pos++; 1657 /* fall through */ 1658 case 1: 1659 ino = parent_ino(dentry); 1660 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 1661 goto out; 1662 i++; 1663 filp->f_pos++; 1664 /* fall through */ 1665 default: 1666 i -= 2; 1667 if (i >= nents) { 1668 ret = 1; 1669 goto out; 1670 } 1671 p = ents + i; 1672 last = &ents[nents - 1]; 1673 while (p <= last) { 1674 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 1675 goto out; 1676 filp->f_pos++; 1677 p++; 1678 } 1679 } 1680 1681 ret = 1; 1682 out: 1683 put_task_struct(task); 1684 out_no_task: 1685 return ret; 1686 } 1687 1688 #ifdef CONFIG_SECURITY 1689 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 1690 size_t count, loff_t *ppos) 1691 { 1692 struct inode * inode = file->f_path.dentry->d_inode; 1693 char *p = NULL; 1694 ssize_t length; 1695 struct task_struct *task = get_proc_task(inode); 1696 1697 if (!task) 1698 return -ESRCH; 1699 1700 length = security_getprocattr(task, 1701 (char*)file->f_path.dentry->d_name.name, 1702 &p); 1703 put_task_struct(task); 1704 if (length > 0) 1705 length = simple_read_from_buffer(buf, count, ppos, p, length); 1706 kfree(p); 1707 return length; 1708 } 1709 1710 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 1711 size_t count, loff_t *ppos) 1712 { 1713 struct inode * inode = file->f_path.dentry->d_inode; 1714 char *page; 1715 ssize_t length; 1716 struct task_struct *task = get_proc_task(inode); 1717 1718 length = -ESRCH; 1719 if (!task) 1720 goto out_no_task; 1721 if (count > PAGE_SIZE) 1722 count = PAGE_SIZE; 1723 1724 /* No partial writes. */ 1725 length = -EINVAL; 1726 if (*ppos != 0) 1727 goto out; 1728 1729 length = -ENOMEM; 1730 page = (char*)__get_free_page(GFP_TEMPORARY); 1731 if (!page) 1732 goto out; 1733 1734 length = -EFAULT; 1735 if (copy_from_user(page, buf, count)) 1736 goto out_free; 1737 1738 length = security_setprocattr(task, 1739 (char*)file->f_path.dentry->d_name.name, 1740 (void*)page, count); 1741 out_free: 1742 free_page((unsigned long) page); 1743 out: 1744 put_task_struct(task); 1745 out_no_task: 1746 return length; 1747 } 1748 1749 static const struct file_operations proc_pid_attr_operations = { 1750 .read = proc_pid_attr_read, 1751 .write = proc_pid_attr_write, 1752 }; 1753 1754 static const struct pid_entry attr_dir_stuff[] = { 1755 REG("current", S_IRUGO|S_IWUGO, pid_attr), 1756 REG("prev", S_IRUGO, pid_attr), 1757 REG("exec", S_IRUGO|S_IWUGO, pid_attr), 1758 REG("fscreate", S_IRUGO|S_IWUGO, pid_attr), 1759 REG("keycreate", S_IRUGO|S_IWUGO, pid_attr), 1760 REG("sockcreate", S_IRUGO|S_IWUGO, pid_attr), 1761 }; 1762 1763 static int proc_attr_dir_readdir(struct file * filp, 1764 void * dirent, filldir_t filldir) 1765 { 1766 return proc_pident_readdir(filp,dirent,filldir, 1767 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 1768 } 1769 1770 static const struct file_operations proc_attr_dir_operations = { 1771 .read = generic_read_dir, 1772 .readdir = proc_attr_dir_readdir, 1773 }; 1774 1775 static struct dentry *proc_attr_dir_lookup(struct inode *dir, 1776 struct dentry *dentry, struct nameidata *nd) 1777 { 1778 return proc_pident_lookup(dir, dentry, 1779 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 1780 } 1781 1782 static const struct inode_operations proc_attr_dir_inode_operations = { 1783 .lookup = proc_attr_dir_lookup, 1784 .getattr = pid_getattr, 1785 .setattr = proc_setattr, 1786 }; 1787 1788 #endif 1789 1790 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 1791 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, 1792 size_t count, loff_t *ppos) 1793 { 1794 struct task_struct *task = get_proc_task(file->f_dentry->d_inode); 1795 struct mm_struct *mm; 1796 char buffer[PROC_NUMBUF]; 1797 size_t len; 1798 int ret; 1799 1800 if (!task) 1801 return -ESRCH; 1802 1803 ret = 0; 1804 mm = get_task_mm(task); 1805 if (mm) { 1806 len = snprintf(buffer, sizeof(buffer), "%08lx\n", 1807 ((mm->flags & MMF_DUMP_FILTER_MASK) >> 1808 MMF_DUMP_FILTER_SHIFT)); 1809 mmput(mm); 1810 ret = simple_read_from_buffer(buf, count, ppos, buffer, len); 1811 } 1812 1813 put_task_struct(task); 1814 1815 return ret; 1816 } 1817 1818 static ssize_t proc_coredump_filter_write(struct file *file, 1819 const char __user *buf, 1820 size_t count, 1821 loff_t *ppos) 1822 { 1823 struct task_struct *task; 1824 struct mm_struct *mm; 1825 char buffer[PROC_NUMBUF], *end; 1826 unsigned int val; 1827 int ret; 1828 int i; 1829 unsigned long mask; 1830 1831 ret = -EFAULT; 1832 memset(buffer, 0, sizeof(buffer)); 1833 if (count > sizeof(buffer) - 1) 1834 count = sizeof(buffer) - 1; 1835 if (copy_from_user(buffer, buf, count)) 1836 goto out_no_task; 1837 1838 ret = -EINVAL; 1839 val = (unsigned int)simple_strtoul(buffer, &end, 0); 1840 if (*end == '\n') 1841 end++; 1842 if (end - buffer == 0) 1843 goto out_no_task; 1844 1845 ret = -ESRCH; 1846 task = get_proc_task(file->f_dentry->d_inode); 1847 if (!task) 1848 goto out_no_task; 1849 1850 ret = end - buffer; 1851 mm = get_task_mm(task); 1852 if (!mm) 1853 goto out_no_mm; 1854 1855 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { 1856 if (val & mask) 1857 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 1858 else 1859 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); 1860 } 1861 1862 mmput(mm); 1863 out_no_mm: 1864 put_task_struct(task); 1865 out_no_task: 1866 return ret; 1867 } 1868 1869 static const struct file_operations proc_coredump_filter_operations = { 1870 .read = proc_coredump_filter_read, 1871 .write = proc_coredump_filter_write, 1872 }; 1873 #endif 1874 1875 /* 1876 * /proc/self: 1877 */ 1878 static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 1879 int buflen) 1880 { 1881 char tmp[PROC_NUMBUF]; 1882 sprintf(tmp, "%d", current->tgid); 1883 return vfs_readlink(dentry,buffer,buflen,tmp); 1884 } 1885 1886 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 1887 { 1888 char tmp[PROC_NUMBUF]; 1889 sprintf(tmp, "%d", current->tgid); 1890 return ERR_PTR(vfs_follow_link(nd,tmp)); 1891 } 1892 1893 static const struct inode_operations proc_self_inode_operations = { 1894 .readlink = proc_self_readlink, 1895 .follow_link = proc_self_follow_link, 1896 }; 1897 1898 /* 1899 * proc base 1900 * 1901 * These are the directory entries in the root directory of /proc 1902 * that properly belong to the /proc filesystem, as they describe 1903 * describe something that is process related. 1904 */ 1905 static const struct pid_entry proc_base_stuff[] = { 1906 NOD("self", S_IFLNK|S_IRWXUGO, 1907 &proc_self_inode_operations, NULL, {}), 1908 }; 1909 1910 /* 1911 * Exceptional case: normally we are not allowed to unhash a busy 1912 * directory. In this case, however, we can do it - no aliasing problems 1913 * due to the way we treat inodes. 1914 */ 1915 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) 1916 { 1917 struct inode *inode = dentry->d_inode; 1918 struct task_struct *task = get_proc_task(inode); 1919 if (task) { 1920 put_task_struct(task); 1921 return 1; 1922 } 1923 d_drop(dentry); 1924 return 0; 1925 } 1926 1927 static struct dentry_operations proc_base_dentry_operations = 1928 { 1929 .d_revalidate = proc_base_revalidate, 1930 .d_delete = pid_delete_dentry, 1931 }; 1932 1933 static struct dentry *proc_base_instantiate(struct inode *dir, 1934 struct dentry *dentry, struct task_struct *task, const void *ptr) 1935 { 1936 const struct pid_entry *p = ptr; 1937 struct inode *inode; 1938 struct proc_inode *ei; 1939 struct dentry *error = ERR_PTR(-EINVAL); 1940 1941 /* Allocate the inode */ 1942 error = ERR_PTR(-ENOMEM); 1943 inode = new_inode(dir->i_sb); 1944 if (!inode) 1945 goto out; 1946 1947 /* Initialize the inode */ 1948 ei = PROC_I(inode); 1949 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1950 1951 /* 1952 * grab the reference to the task. 1953 */ 1954 ei->pid = get_task_pid(task, PIDTYPE_PID); 1955 if (!ei->pid) 1956 goto out_iput; 1957 1958 inode->i_uid = 0; 1959 inode->i_gid = 0; 1960 inode->i_mode = p->mode; 1961 if (S_ISDIR(inode->i_mode)) 1962 inode->i_nlink = 2; 1963 if (S_ISLNK(inode->i_mode)) 1964 inode->i_size = 64; 1965 if (p->iop) 1966 inode->i_op = p->iop; 1967 if (p->fop) 1968 inode->i_fop = p->fop; 1969 ei->op = p->op; 1970 dentry->d_op = &proc_base_dentry_operations; 1971 d_add(dentry, inode); 1972 error = NULL; 1973 out: 1974 return error; 1975 out_iput: 1976 iput(inode); 1977 goto out; 1978 } 1979 1980 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 1981 { 1982 struct dentry *error; 1983 struct task_struct *task = get_proc_task(dir); 1984 const struct pid_entry *p, *last; 1985 1986 error = ERR_PTR(-ENOENT); 1987 1988 if (!task) 1989 goto out_no_task; 1990 1991 /* Lookup the directory entry */ 1992 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 1993 for (p = proc_base_stuff; p <= last; p++) { 1994 if (p->len != dentry->d_name.len) 1995 continue; 1996 if (!memcmp(dentry->d_name.name, p->name, p->len)) 1997 break; 1998 } 1999 if (p > last) 2000 goto out; 2001 2002 error = proc_base_instantiate(dir, dentry, task, p); 2003 2004 out: 2005 put_task_struct(task); 2006 out_no_task: 2007 return error; 2008 } 2009 2010 static int proc_base_fill_cache(struct file *filp, void *dirent, 2011 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 2012 { 2013 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 2014 proc_base_instantiate, task, p); 2015 } 2016 2017 #ifdef CONFIG_TASK_IO_ACCOUNTING 2018 static int proc_pid_io_accounting(struct task_struct *task, char *buffer) 2019 { 2020 return sprintf(buffer, 2021 #ifdef CONFIG_TASK_XACCT 2022 "rchar: %llu\n" 2023 "wchar: %llu\n" 2024 "syscr: %llu\n" 2025 "syscw: %llu\n" 2026 #endif 2027 "read_bytes: %llu\n" 2028 "write_bytes: %llu\n" 2029 "cancelled_write_bytes: %llu\n", 2030 #ifdef CONFIG_TASK_XACCT 2031 (unsigned long long)task->rchar, 2032 (unsigned long long)task->wchar, 2033 (unsigned long long)task->syscr, 2034 (unsigned long long)task->syscw, 2035 #endif 2036 (unsigned long long)task->ioac.read_bytes, 2037 (unsigned long long)task->ioac.write_bytes, 2038 (unsigned long long)task->ioac.cancelled_write_bytes); 2039 } 2040 #endif 2041 2042 /* 2043 * Thread groups 2044 */ 2045 static const struct file_operations proc_task_operations; 2046 static const struct inode_operations proc_task_inode_operations; 2047 2048 static const struct pid_entry tgid_base_stuff[] = { 2049 DIR("task", S_IRUGO|S_IXUGO, task), 2050 DIR("fd", S_IRUSR|S_IXUSR, fd), 2051 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), 2052 INF("environ", S_IRUSR, pid_environ), 2053 INF("auxv", S_IRUSR, pid_auxv), 2054 INF("status", S_IRUGO, pid_status), 2055 #ifdef CONFIG_SCHED_DEBUG 2056 REG("sched", S_IRUGO|S_IWUSR, pid_sched), 2057 #endif 2058 INF("cmdline", S_IRUGO, pid_cmdline), 2059 INF("stat", S_IRUGO, tgid_stat), 2060 INF("statm", S_IRUGO, pid_statm), 2061 REG("maps", S_IRUGO, maps), 2062 #ifdef CONFIG_NUMA 2063 REG("numa_maps", S_IRUGO, numa_maps), 2064 #endif 2065 REG("mem", S_IRUSR|S_IWUSR, mem), 2066 LNK("cwd", cwd), 2067 LNK("root", root), 2068 LNK("exe", exe), 2069 REG("mounts", S_IRUGO, mounts), 2070 REG("mountstats", S_IRUSR, mountstats), 2071 #ifdef CONFIG_MMU 2072 REG("clear_refs", S_IWUSR, clear_refs), 2073 REG("smaps", S_IRUGO, smaps), 2074 #endif 2075 #ifdef CONFIG_SECURITY 2076 DIR("attr", S_IRUGO|S_IXUGO, attr_dir), 2077 #endif 2078 #ifdef CONFIG_KALLSYMS 2079 INF("wchan", S_IRUGO, pid_wchan), 2080 #endif 2081 #ifdef CONFIG_SCHEDSTATS 2082 INF("schedstat", S_IRUGO, pid_schedstat), 2083 #endif 2084 #ifdef CONFIG_CPUSETS 2085 REG("cpuset", S_IRUGO, cpuset), 2086 #endif 2087 INF("oom_score", S_IRUGO, oom_score), 2088 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust), 2089 #ifdef CONFIG_AUDITSYSCALL 2090 REG("loginuid", S_IWUSR|S_IRUGO, loginuid), 2091 #endif 2092 #ifdef CONFIG_FAULT_INJECTION 2093 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject), 2094 #endif 2095 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 2096 REG("coredump_filter", S_IRUGO|S_IWUSR, coredump_filter), 2097 #endif 2098 #ifdef CONFIG_TASK_IO_ACCOUNTING 2099 INF("io", S_IRUGO, pid_io_accounting), 2100 #endif 2101 }; 2102 2103 static int proc_tgid_base_readdir(struct file * filp, 2104 void * dirent, filldir_t filldir) 2105 { 2106 return proc_pident_readdir(filp,dirent,filldir, 2107 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2108 } 2109 2110 static const struct file_operations proc_tgid_base_operations = { 2111 .read = generic_read_dir, 2112 .readdir = proc_tgid_base_readdir, 2113 }; 2114 2115 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2116 return proc_pident_lookup(dir, dentry, 2117 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2118 } 2119 2120 static const struct inode_operations proc_tgid_base_inode_operations = { 2121 .lookup = proc_tgid_base_lookup, 2122 .getattr = pid_getattr, 2123 .setattr = proc_setattr, 2124 }; 2125 2126 /** 2127 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2128 * 2129 * @task: task that should be flushed. 2130 * 2131 * Looks in the dcache for 2132 * /proc/@pid 2133 * /proc/@tgid/task/@pid 2134 * if either directory is present flushes it and all of it'ts children 2135 * from the dcache. 2136 * 2137 * It is safe and reasonable to cache /proc entries for a task until 2138 * that task exits. After that they just clog up the dcache with 2139 * useless entries, possibly causing useful dcache entries to be 2140 * flushed instead. This routine is proved to flush those useless 2141 * dcache entries at process exit time. 2142 * 2143 * NOTE: This routine is just an optimization so it does not guarantee 2144 * that no dcache entries will exist at process exit time it 2145 * just makes it very unlikely that any will persist. 2146 */ 2147 void proc_flush_task(struct task_struct *task) 2148 { 2149 struct dentry *dentry, *leader, *dir; 2150 char buf[PROC_NUMBUF]; 2151 struct qstr name; 2152 2153 name.name = buf; 2154 name.len = snprintf(buf, sizeof(buf), "%d", task->pid); 2155 dentry = d_hash_and_lookup(proc_mnt->mnt_root, &name); 2156 if (dentry) { 2157 shrink_dcache_parent(dentry); 2158 d_drop(dentry); 2159 dput(dentry); 2160 } 2161 2162 if (thread_group_leader(task)) 2163 goto out; 2164 2165 name.name = buf; 2166 name.len = snprintf(buf, sizeof(buf), "%d", task->tgid); 2167 leader = d_hash_and_lookup(proc_mnt->mnt_root, &name); 2168 if (!leader) 2169 goto out; 2170 2171 name.name = "task"; 2172 name.len = strlen(name.name); 2173 dir = d_hash_and_lookup(leader, &name); 2174 if (!dir) 2175 goto out_put_leader; 2176 2177 name.name = buf; 2178 name.len = snprintf(buf, sizeof(buf), "%d", task->pid); 2179 dentry = d_hash_and_lookup(dir, &name); 2180 if (dentry) { 2181 shrink_dcache_parent(dentry); 2182 d_drop(dentry); 2183 dput(dentry); 2184 } 2185 2186 dput(dir); 2187 out_put_leader: 2188 dput(leader); 2189 out: 2190 return; 2191 } 2192 2193 static struct dentry *proc_pid_instantiate(struct inode *dir, 2194 struct dentry * dentry, 2195 struct task_struct *task, const void *ptr) 2196 { 2197 struct dentry *error = ERR_PTR(-ENOENT); 2198 struct inode *inode; 2199 2200 inode = proc_pid_make_inode(dir->i_sb, task); 2201 if (!inode) 2202 goto out; 2203 2204 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2205 inode->i_op = &proc_tgid_base_inode_operations; 2206 inode->i_fop = &proc_tgid_base_operations; 2207 inode->i_flags|=S_IMMUTABLE; 2208 inode->i_nlink = 5; 2209 #ifdef CONFIG_SECURITY 2210 inode->i_nlink += 1; 2211 #endif 2212 2213 dentry->d_op = &pid_dentry_operations; 2214 2215 d_add(dentry, inode); 2216 /* Close the race of the process dying before we return the dentry */ 2217 if (pid_revalidate(dentry, NULL)) 2218 error = NULL; 2219 out: 2220 return error; 2221 } 2222 2223 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2224 { 2225 struct dentry *result = ERR_PTR(-ENOENT); 2226 struct task_struct *task; 2227 unsigned tgid; 2228 2229 result = proc_base_lookup(dir, dentry); 2230 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 2231 goto out; 2232 2233 tgid = name_to_int(dentry); 2234 if (tgid == ~0U) 2235 goto out; 2236 2237 rcu_read_lock(); 2238 task = find_task_by_pid(tgid); 2239 if (task) 2240 get_task_struct(task); 2241 rcu_read_unlock(); 2242 if (!task) 2243 goto out; 2244 2245 result = proc_pid_instantiate(dir, dentry, task, NULL); 2246 put_task_struct(task); 2247 out: 2248 return result; 2249 } 2250 2251 /* 2252 * Find the first task with tgid >= tgid 2253 * 2254 */ 2255 static struct task_struct *next_tgid(unsigned int tgid) 2256 { 2257 struct task_struct *task; 2258 struct pid *pid; 2259 2260 rcu_read_lock(); 2261 retry: 2262 task = NULL; 2263 pid = find_ge_pid(tgid); 2264 if (pid) { 2265 tgid = pid->nr + 1; 2266 task = pid_task(pid, PIDTYPE_PID); 2267 /* What we to know is if the pid we have find is the 2268 * pid of a thread_group_leader. Testing for task 2269 * being a thread_group_leader is the obvious thing 2270 * todo but there is a window when it fails, due to 2271 * the pid transfer logic in de_thread. 2272 * 2273 * So we perform the straight forward test of seeing 2274 * if the pid we have found is the pid of a thread 2275 * group leader, and don't worry if the task we have 2276 * found doesn't happen to be a thread group leader. 2277 * As we don't care in the case of readdir. 2278 */ 2279 if (!task || !has_group_leader_pid(task)) 2280 goto retry; 2281 get_task_struct(task); 2282 } 2283 rcu_read_unlock(); 2284 return task; 2285 } 2286 2287 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 2288 2289 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2290 struct task_struct *task, int tgid) 2291 { 2292 char name[PROC_NUMBUF]; 2293 int len = snprintf(name, sizeof(name), "%d", tgid); 2294 return proc_fill_cache(filp, dirent, filldir, name, len, 2295 proc_pid_instantiate, task, NULL); 2296 } 2297 2298 /* for the /proc/ directory itself, after non-process stuff has been done */ 2299 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 2300 { 2301 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; 2302 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode); 2303 struct task_struct *task; 2304 int tgid; 2305 2306 if (!reaper) 2307 goto out_no_task; 2308 2309 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 2310 const struct pid_entry *p = &proc_base_stuff[nr]; 2311 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 2312 goto out; 2313 } 2314 2315 tgid = filp->f_pos - TGID_OFFSET; 2316 for (task = next_tgid(tgid); 2317 task; 2318 put_task_struct(task), task = next_tgid(tgid + 1)) { 2319 tgid = task->pid; 2320 filp->f_pos = tgid + TGID_OFFSET; 2321 if (proc_pid_fill_cache(filp, dirent, filldir, task, tgid) < 0) { 2322 put_task_struct(task); 2323 goto out; 2324 } 2325 } 2326 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 2327 out: 2328 put_task_struct(reaper); 2329 out_no_task: 2330 return 0; 2331 } 2332 2333 /* 2334 * Tasks 2335 */ 2336 static const struct pid_entry tid_base_stuff[] = { 2337 DIR("fd", S_IRUSR|S_IXUSR, fd), 2338 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), 2339 INF("environ", S_IRUSR, pid_environ), 2340 INF("auxv", S_IRUSR, pid_auxv), 2341 INF("status", S_IRUGO, pid_status), 2342 #ifdef CONFIG_SCHED_DEBUG 2343 REG("sched", S_IRUGO|S_IWUSR, pid_sched), 2344 #endif 2345 INF("cmdline", S_IRUGO, pid_cmdline), 2346 INF("stat", S_IRUGO, tid_stat), 2347 INF("statm", S_IRUGO, pid_statm), 2348 REG("maps", S_IRUGO, maps), 2349 #ifdef CONFIG_NUMA 2350 REG("numa_maps", S_IRUGO, numa_maps), 2351 #endif 2352 REG("mem", S_IRUSR|S_IWUSR, mem), 2353 LNK("cwd", cwd), 2354 LNK("root", root), 2355 LNK("exe", exe), 2356 REG("mounts", S_IRUGO, mounts), 2357 #ifdef CONFIG_MMU 2358 REG("clear_refs", S_IWUSR, clear_refs), 2359 REG("smaps", S_IRUGO, smaps), 2360 #endif 2361 #ifdef CONFIG_SECURITY 2362 DIR("attr", S_IRUGO|S_IXUGO, attr_dir), 2363 #endif 2364 #ifdef CONFIG_KALLSYMS 2365 INF("wchan", S_IRUGO, pid_wchan), 2366 #endif 2367 #ifdef CONFIG_SCHEDSTATS 2368 INF("schedstat", S_IRUGO, pid_schedstat), 2369 #endif 2370 #ifdef CONFIG_CPUSETS 2371 REG("cpuset", S_IRUGO, cpuset), 2372 #endif 2373 INF("oom_score", S_IRUGO, oom_score), 2374 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust), 2375 #ifdef CONFIG_AUDITSYSCALL 2376 REG("loginuid", S_IWUSR|S_IRUGO, loginuid), 2377 #endif 2378 #ifdef CONFIG_FAULT_INJECTION 2379 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject), 2380 #endif 2381 }; 2382 2383 static int proc_tid_base_readdir(struct file * filp, 2384 void * dirent, filldir_t filldir) 2385 { 2386 return proc_pident_readdir(filp,dirent,filldir, 2387 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 2388 } 2389 2390 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2391 return proc_pident_lookup(dir, dentry, 2392 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 2393 } 2394 2395 static const struct file_operations proc_tid_base_operations = { 2396 .read = generic_read_dir, 2397 .readdir = proc_tid_base_readdir, 2398 }; 2399 2400 static const struct inode_operations proc_tid_base_inode_operations = { 2401 .lookup = proc_tid_base_lookup, 2402 .getattr = pid_getattr, 2403 .setattr = proc_setattr, 2404 }; 2405 2406 static struct dentry *proc_task_instantiate(struct inode *dir, 2407 struct dentry *dentry, struct task_struct *task, const void *ptr) 2408 { 2409 struct dentry *error = ERR_PTR(-ENOENT); 2410 struct inode *inode; 2411 inode = proc_pid_make_inode(dir->i_sb, task); 2412 2413 if (!inode) 2414 goto out; 2415 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2416 inode->i_op = &proc_tid_base_inode_operations; 2417 inode->i_fop = &proc_tid_base_operations; 2418 inode->i_flags|=S_IMMUTABLE; 2419 inode->i_nlink = 4; 2420 #ifdef CONFIG_SECURITY 2421 inode->i_nlink += 1; 2422 #endif 2423 2424 dentry->d_op = &pid_dentry_operations; 2425 2426 d_add(dentry, inode); 2427 /* Close the race of the process dying before we return the dentry */ 2428 if (pid_revalidate(dentry, NULL)) 2429 error = NULL; 2430 out: 2431 return error; 2432 } 2433 2434 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2435 { 2436 struct dentry *result = ERR_PTR(-ENOENT); 2437 struct task_struct *task; 2438 struct task_struct *leader = get_proc_task(dir); 2439 unsigned tid; 2440 2441 if (!leader) 2442 goto out_no_task; 2443 2444 tid = name_to_int(dentry); 2445 if (tid == ~0U) 2446 goto out; 2447 2448 rcu_read_lock(); 2449 task = find_task_by_pid(tid); 2450 if (task) 2451 get_task_struct(task); 2452 rcu_read_unlock(); 2453 if (!task) 2454 goto out; 2455 if (leader->tgid != task->tgid) 2456 goto out_drop_task; 2457 2458 result = proc_task_instantiate(dir, dentry, task, NULL); 2459 out_drop_task: 2460 put_task_struct(task); 2461 out: 2462 put_task_struct(leader); 2463 out_no_task: 2464 return result; 2465 } 2466 2467 /* 2468 * Find the first tid of a thread group to return to user space. 2469 * 2470 * Usually this is just the thread group leader, but if the users 2471 * buffer was too small or there was a seek into the middle of the 2472 * directory we have more work todo. 2473 * 2474 * In the case of a short read we start with find_task_by_pid. 2475 * 2476 * In the case of a seek we start with the leader and walk nr 2477 * threads past it. 2478 */ 2479 static struct task_struct *first_tid(struct task_struct *leader, 2480 int tid, int nr) 2481 { 2482 struct task_struct *pos; 2483 2484 rcu_read_lock(); 2485 /* Attempt to start with the pid of a thread */ 2486 if (tid && (nr > 0)) { 2487 pos = find_task_by_pid(tid); 2488 if (pos && (pos->group_leader == leader)) 2489 goto found; 2490 } 2491 2492 /* If nr exceeds the number of threads there is nothing todo */ 2493 pos = NULL; 2494 if (nr && nr >= get_nr_threads(leader)) 2495 goto out; 2496 2497 /* If we haven't found our starting place yet start 2498 * with the leader and walk nr threads forward. 2499 */ 2500 for (pos = leader; nr > 0; --nr) { 2501 pos = next_thread(pos); 2502 if (pos == leader) { 2503 pos = NULL; 2504 goto out; 2505 } 2506 } 2507 found: 2508 get_task_struct(pos); 2509 out: 2510 rcu_read_unlock(); 2511 return pos; 2512 } 2513 2514 /* 2515 * Find the next thread in the thread list. 2516 * Return NULL if there is an error or no next thread. 2517 * 2518 * The reference to the input task_struct is released. 2519 */ 2520 static struct task_struct *next_tid(struct task_struct *start) 2521 { 2522 struct task_struct *pos = NULL; 2523 rcu_read_lock(); 2524 if (pid_alive(start)) { 2525 pos = next_thread(start); 2526 if (thread_group_leader(pos)) 2527 pos = NULL; 2528 else 2529 get_task_struct(pos); 2530 } 2531 rcu_read_unlock(); 2532 put_task_struct(start); 2533 return pos; 2534 } 2535 2536 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2537 struct task_struct *task, int tid) 2538 { 2539 char name[PROC_NUMBUF]; 2540 int len = snprintf(name, sizeof(name), "%d", tid); 2541 return proc_fill_cache(filp, dirent, filldir, name, len, 2542 proc_task_instantiate, task, NULL); 2543 } 2544 2545 /* for the /proc/TGID/task/ directories */ 2546 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 2547 { 2548 struct dentry *dentry = filp->f_path.dentry; 2549 struct inode *inode = dentry->d_inode; 2550 struct task_struct *leader = NULL; 2551 struct task_struct *task; 2552 int retval = -ENOENT; 2553 ino_t ino; 2554 int tid; 2555 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */ 2556 2557 task = get_proc_task(inode); 2558 if (!task) 2559 goto out_no_task; 2560 rcu_read_lock(); 2561 if (pid_alive(task)) { 2562 leader = task->group_leader; 2563 get_task_struct(leader); 2564 } 2565 rcu_read_unlock(); 2566 put_task_struct(task); 2567 if (!leader) 2568 goto out_no_task; 2569 retval = 0; 2570 2571 switch (pos) { 2572 case 0: 2573 ino = inode->i_ino; 2574 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0) 2575 goto out; 2576 pos++; 2577 /* fall through */ 2578 case 1: 2579 ino = parent_ino(dentry); 2580 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0) 2581 goto out; 2582 pos++; 2583 /* fall through */ 2584 } 2585 2586 /* f_version caches the tgid value that the last readdir call couldn't 2587 * return. lseek aka telldir automagically resets f_version to 0. 2588 */ 2589 tid = filp->f_version; 2590 filp->f_version = 0; 2591 for (task = first_tid(leader, tid, pos - 2); 2592 task; 2593 task = next_tid(task), pos++) { 2594 tid = task->pid; 2595 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 2596 /* returning this tgid failed, save it as the first 2597 * pid for the next readir call */ 2598 filp->f_version = tid; 2599 put_task_struct(task); 2600 break; 2601 } 2602 } 2603 out: 2604 filp->f_pos = pos; 2605 put_task_struct(leader); 2606 out_no_task: 2607 return retval; 2608 } 2609 2610 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 2611 { 2612 struct inode *inode = dentry->d_inode; 2613 struct task_struct *p = get_proc_task(inode); 2614 generic_fillattr(inode, stat); 2615 2616 if (p) { 2617 rcu_read_lock(); 2618 stat->nlink += get_nr_threads(p); 2619 rcu_read_unlock(); 2620 put_task_struct(p); 2621 } 2622 2623 return 0; 2624 } 2625 2626 static const struct inode_operations proc_task_inode_operations = { 2627 .lookup = proc_task_lookup, 2628 .getattr = proc_task_getattr, 2629 .setattr = proc_setattr, 2630 }; 2631 2632 static const struct file_operations proc_task_operations = { 2633 .read = generic_read_dir, 2634 .readdir = proc_task_readdir, 2635 }; 2636