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