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 92struct 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 126int maps_protect; 127EXPORT_SYMBOL(maps_protect); 128 129static 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 140static 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 153static 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 174static 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 202static 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 218static 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 } 249out_mm: 250 mmput(mm); 251out: 252 return res; 253} 254 255static 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 */ 279static 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 */ 297static int proc_pid_schedstat(struct task_struct *task, char *buffer) 298{ 299 return sprintf(buffer, "%llu %llu %lu\n", 300 task->sched_info.cpu_time, 301 task->sched_info.run_delay, 302 task->sched_info.pcount); 303} 304#endif 305 306/* The badness from the OOM killer */ 307unsigned long badness(struct task_struct *p, unsigned long uptime); 308static 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 */ 325static 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 341static 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 355static const struct inode_operations proc_def_inode_operations = { 356 .setattr = proc_setattr, 357}; 358 359extern struct seq_operations mounts_op; 360struct proc_mounts { 361 struct seq_file m; 362 int event; 363}; 364 365static 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 401static 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 409static 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 427static 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 435extern struct seq_operations mountstats_op; 436static 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 465static 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 474static 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); 498out: 499 put_task_struct(task); 500out_no_task: 501 return length; 502} 503 504static const struct file_operations proc_info_file_operations = { 505 .read = proc_info_read, 506}; 507 508static 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 514static 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 570out_put: 571 mmput(mm); 572out_free: 573 free_page((unsigned long) page); 574out: 575 put_task_struct(task); 576out_no_task: 577 return ret; 578} 579 580#define mem_write NULL 581 582#ifndef mem_write 583/* This is a security hazard */ 584static 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); 626out: 627 put_task_struct(task); 628out_no_task: 629 return copied; 630} 631#endif 632 633static 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 649static 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 656static 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 674static 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 706static const struct file_operations proc_oom_adjust_operations = { 707 .read = oom_adjust_read, 708 .write = oom_adjust_write, 709}; 710 711#ifdef CONFIG_MMU 712static 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 742static struct file_operations proc_clear_refs_operations = { 743 .write = clear_refs_write, 744}; 745#endif 746 747#ifdef CONFIG_AUDITSYSCALL 748#define TMPBUFLEN 21 749static 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 765static 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 804out_free_page: 805 free_page((unsigned long) page); 806 return length; 807} 808 809static 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 816static 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 832static 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; 868out: 869 put_task_struct(tsk); 870out_no_task: 871 return result; 872} 873 874static 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 881static 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 899static 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 926static 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#ifdef CONFIG_SCHED_DEBUG 933/* 934 * Print out various scheduling related per-task fields: 935 */ 936static int sched_show(struct seq_file *m, void *v) 937{ 938 struct inode *inode = m->private; 939 struct task_struct *p; 940 941 WARN_ON(!inode); 942 943 p = get_proc_task(inode); 944 if (!p) 945 return -ESRCH; 946 proc_sched_show_task(p, m); 947 948 put_task_struct(p); 949 950 return 0; 951} 952 953static ssize_t 954sched_write(struct file *file, const char __user *buf, 955 size_t count, loff_t *offset) 956{ 957 struct inode *inode = file->f_path.dentry->d_inode; 958 struct task_struct *p; 959 960 WARN_ON(!inode); 961 962 p = get_proc_task(inode); 963 if (!p) 964 return -ESRCH; 965 proc_sched_set_task(p); 966 967 put_task_struct(p); 968 969 return count; 970} 971 972static int sched_open(struct inode *inode, struct file *filp) 973{ 974 int ret; 975 976 ret = single_open(filp, sched_show, NULL); 977 if (!ret) { 978 struct seq_file *m = filp->private_data; 979 980 m->private = inode; 981 } 982 return ret; 983} 984 985static const struct file_operations proc_pid_sched_operations = { 986 .open = sched_open, 987 .read = seq_read, 988 .write = sched_write, 989 .llseek = seq_lseek, 990 .release = seq_release, 991}; 992 993#endif 994 995static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) 996{ 997 struct inode *inode = dentry->d_inode; 998 int error = -EACCES; 999 1000 /* We don't need a base pointer in the /proc filesystem */ 1001 path_release(nd); 1002 1003 /* Are we allowed to snoop on the tasks file descriptors? */ 1004 if (!proc_fd_access_allowed(inode)) 1005 goto out; 1006 1007 error = PROC_I(inode)->op.proc_get_link(inode, &nd->dentry, &nd->mnt); 1008 nd->last_type = LAST_BIND; 1009out: 1010 return ERR_PTR(error); 1011} 1012 1013static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt, 1014 char __user *buffer, int buflen) 1015{ 1016 struct inode * inode; 1017 char *tmp = (char*)__get_free_page(GFP_KERNEL), *path; 1018 int len; 1019 1020 if (!tmp) 1021 return -ENOMEM; 1022 1023 inode = dentry->d_inode; 1024 path = d_path(dentry, mnt, tmp, PAGE_SIZE); 1025 len = PTR_ERR(path); 1026 if (IS_ERR(path)) 1027 goto out; 1028 len = tmp + PAGE_SIZE - 1 - path; 1029 1030 if (len > buflen) 1031 len = buflen; 1032 if (copy_to_user(buffer, path, len)) 1033 len = -EFAULT; 1034 out: 1035 free_page((unsigned long)tmp); 1036 return len; 1037} 1038 1039static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen) 1040{ 1041 int error = -EACCES; 1042 struct inode *inode = dentry->d_inode; 1043 struct dentry *de; 1044 struct vfsmount *mnt = NULL; 1045 1046 /* Are we allowed to snoop on the tasks file descriptors? */ 1047 if (!proc_fd_access_allowed(inode)) 1048 goto out; 1049 1050 error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt); 1051 if (error) 1052 goto out; 1053 1054 error = do_proc_readlink(de, mnt, buffer, buflen); 1055 dput(de); 1056 mntput(mnt); 1057out: 1058 return error; 1059} 1060 1061static const struct inode_operations proc_pid_link_inode_operations = { 1062 .readlink = proc_pid_readlink, 1063 .follow_link = proc_pid_follow_link, 1064 .setattr = proc_setattr, 1065}; 1066 1067 1068/* building an inode */ 1069 1070static int task_dumpable(struct task_struct *task) 1071{ 1072 int dumpable = 0; 1073 struct mm_struct *mm; 1074 1075 task_lock(task); 1076 mm = task->mm; 1077 if (mm) 1078 dumpable = mm->dumpable; 1079 task_unlock(task); 1080 if(dumpable == 1) 1081 return 1; 1082 return 0; 1083} 1084 1085 1086static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task) 1087{ 1088 struct inode * inode; 1089 struct proc_inode *ei; 1090 1091 /* We need a new inode */ 1092 1093 inode = new_inode(sb); 1094 if (!inode) 1095 goto out; 1096 1097 /* Common stuff */ 1098 ei = PROC_I(inode); 1099 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1100 inode->i_op = &proc_def_inode_operations; 1101 1102 /* 1103 * grab the reference to task. 1104 */ 1105 ei->pid = get_task_pid(task, PIDTYPE_PID); 1106 if (!ei->pid) 1107 goto out_unlock; 1108 1109 inode->i_uid = 0; 1110 inode->i_gid = 0; 1111 if (task_dumpable(task)) { 1112 inode->i_uid = task->euid; 1113 inode->i_gid = task->egid; 1114 } 1115 security_task_to_inode(task, inode); 1116 1117out: 1118 return inode; 1119 1120out_unlock: 1121 iput(inode); 1122 return NULL; 1123} 1124 1125static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 1126{ 1127 struct inode *inode = dentry->d_inode; 1128 struct task_struct *task; 1129 generic_fillattr(inode, stat); 1130 1131 rcu_read_lock(); 1132 stat->uid = 0; 1133 stat->gid = 0; 1134 task = pid_task(proc_pid(inode), PIDTYPE_PID); 1135 if (task) { 1136 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1137 task_dumpable(task)) { 1138 stat->uid = task->euid; 1139 stat->gid = task->egid; 1140 } 1141 } 1142 rcu_read_unlock(); 1143 return 0; 1144} 1145 1146/* dentry stuff */ 1147 1148/* 1149 * Exceptional case: normally we are not allowed to unhash a busy 1150 * directory. In this case, however, we can do it - no aliasing problems 1151 * due to the way we treat inodes. 1152 * 1153 * Rewrite the inode's ownerships here because the owning task may have 1154 * performed a setuid(), etc. 1155 * 1156 * Before the /proc/pid/status file was created the only way to read 1157 * the effective uid of a /process was to stat /proc/pid. Reading 1158 * /proc/pid/status is slow enough that procps and other packages 1159 * kept stating /proc/pid. To keep the rules in /proc simple I have 1160 * made this apply to all per process world readable and executable 1161 * directories. 1162 */ 1163static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) 1164{ 1165 struct inode *inode = dentry->d_inode; 1166 struct task_struct *task = get_proc_task(inode); 1167 if (task) { 1168 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || 1169 task_dumpable(task)) { 1170 inode->i_uid = task->euid; 1171 inode->i_gid = task->egid; 1172 } else { 1173 inode->i_uid = 0; 1174 inode->i_gid = 0; 1175 } 1176 inode->i_mode &= ~(S_ISUID | S_ISGID); 1177 security_task_to_inode(task, inode); 1178 put_task_struct(task); 1179 return 1; 1180 } 1181 d_drop(dentry); 1182 return 0; 1183} 1184 1185static int pid_delete_dentry(struct dentry * dentry) 1186{ 1187 /* Is the task we represent dead? 1188 * If so, then don't put the dentry on the lru list, 1189 * kill it immediately. 1190 */ 1191 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; 1192} 1193 1194static struct dentry_operations pid_dentry_operations = 1195{ 1196 .d_revalidate = pid_revalidate, 1197 .d_delete = pid_delete_dentry, 1198}; 1199 1200/* Lookups */ 1201 1202typedef struct dentry *instantiate_t(struct inode *, struct dentry *, 1203 struct task_struct *, const void *); 1204 1205/* 1206 * Fill a directory entry. 1207 * 1208 * If possible create the dcache entry and derive our inode number and 1209 * file type from dcache entry. 1210 * 1211 * Since all of the proc inode numbers are dynamically generated, the inode 1212 * numbers do not exist until the inode is cache. This means creating the 1213 * the dcache entry in readdir is necessary to keep the inode numbers 1214 * reported by readdir in sync with the inode numbers reported 1215 * by stat. 1216 */ 1217static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 1218 char *name, int len, 1219 instantiate_t instantiate, struct task_struct *task, const void *ptr) 1220{ 1221 struct dentry *child, *dir = filp->f_path.dentry; 1222 struct inode *inode; 1223 struct qstr qname; 1224 ino_t ino = 0; 1225 unsigned type = DT_UNKNOWN; 1226 1227 qname.name = name; 1228 qname.len = len; 1229 qname.hash = full_name_hash(name, len); 1230 1231 child = d_lookup(dir, &qname); 1232 if (!child) { 1233 struct dentry *new; 1234 new = d_alloc(dir, &qname); 1235 if (new) { 1236 child = instantiate(dir->d_inode, new, task, ptr); 1237 if (child) 1238 dput(new); 1239 else 1240 child = new; 1241 } 1242 } 1243 if (!child || IS_ERR(child) || !child->d_inode) 1244 goto end_instantiate; 1245 inode = child->d_inode; 1246 if (inode) { 1247 ino = inode->i_ino; 1248 type = inode->i_mode >> 12; 1249 } 1250 dput(child); 1251end_instantiate: 1252 if (!ino) 1253 ino = find_inode_number(dir, &qname); 1254 if (!ino) 1255 ino = 1; 1256 return filldir(dirent, name, len, filp->f_pos, ino, type); 1257} 1258 1259static unsigned name_to_int(struct dentry *dentry) 1260{ 1261 const char *name = dentry->d_name.name; 1262 int len = dentry->d_name.len; 1263 unsigned n = 0; 1264 1265 if (len > 1 && *name == '0') 1266 goto out; 1267 while (len-- > 0) { 1268 unsigned c = *name++ - '0'; 1269 if (c > 9) 1270 goto out; 1271 if (n >= (~0U-9)/10) 1272 goto out; 1273 n *= 10; 1274 n += c; 1275 } 1276 return n; 1277out: 1278 return ~0U; 1279} 1280 1281#define PROC_FDINFO_MAX 64 1282 1283static int proc_fd_info(struct inode *inode, struct dentry **dentry, 1284 struct vfsmount **mnt, char *info) 1285{ 1286 struct task_struct *task = get_proc_task(inode); 1287 struct files_struct *files = NULL; 1288 struct file *file; 1289 int fd = proc_fd(inode); 1290 1291 if (task) { 1292 files = get_files_struct(task); 1293 put_task_struct(task); 1294 } 1295 if (files) { 1296 /* 1297 * We are not taking a ref to the file structure, so we must 1298 * hold ->file_lock. 1299 */ 1300 spin_lock(&files->file_lock); 1301 file = fcheck_files(files, fd); 1302 if (file) { 1303 if (mnt) 1304 *mnt = mntget(file->f_path.mnt); 1305 if (dentry) 1306 *dentry = dget(file->f_path.dentry); 1307 if (info) 1308 snprintf(info, PROC_FDINFO_MAX, 1309 "pos:\t%lli\n" 1310 "flags:\t0%o\n", 1311 (long long) file->f_pos, 1312 file->f_flags); 1313 spin_unlock(&files->file_lock); 1314 put_files_struct(files); 1315 return 0; 1316 } 1317 spin_unlock(&files->file_lock); 1318 put_files_struct(files); 1319 } 1320 return -ENOENT; 1321} 1322 1323static int proc_fd_link(struct inode *inode, struct dentry **dentry, 1324 struct vfsmount **mnt) 1325{ 1326 return proc_fd_info(inode, dentry, mnt, NULL); 1327} 1328 1329static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) 1330{ 1331 struct inode *inode = dentry->d_inode; 1332 struct task_struct *task = get_proc_task(inode); 1333 int fd = proc_fd(inode); 1334 struct files_struct *files; 1335 1336 if (task) { 1337 files = get_files_struct(task); 1338 if (files) { 1339 rcu_read_lock(); 1340 if (fcheck_files(files, fd)) { 1341 rcu_read_unlock(); 1342 put_files_struct(files); 1343 if (task_dumpable(task)) { 1344 inode->i_uid = task->euid; 1345 inode->i_gid = task->egid; 1346 } else { 1347 inode->i_uid = 0; 1348 inode->i_gid = 0; 1349 } 1350 inode->i_mode &= ~(S_ISUID | S_ISGID); 1351 security_task_to_inode(task, inode); 1352 put_task_struct(task); 1353 return 1; 1354 } 1355 rcu_read_unlock(); 1356 put_files_struct(files); 1357 } 1358 put_task_struct(task); 1359 } 1360 d_drop(dentry); 1361 return 0; 1362} 1363 1364static struct dentry_operations tid_fd_dentry_operations = 1365{ 1366 .d_revalidate = tid_fd_revalidate, 1367 .d_delete = pid_delete_dentry, 1368}; 1369 1370static struct dentry *proc_fd_instantiate(struct inode *dir, 1371 struct dentry *dentry, struct task_struct *task, const void *ptr) 1372{ 1373 unsigned fd = *(const unsigned *)ptr; 1374 struct file *file; 1375 struct files_struct *files; 1376 struct inode *inode; 1377 struct proc_inode *ei; 1378 struct dentry *error = ERR_PTR(-ENOENT); 1379 1380 inode = proc_pid_make_inode(dir->i_sb, task); 1381 if (!inode) 1382 goto out; 1383 ei = PROC_I(inode); 1384 ei->fd = fd; 1385 files = get_files_struct(task); 1386 if (!files) 1387 goto out_iput; 1388 inode->i_mode = S_IFLNK; 1389 1390 /* 1391 * We are not taking a ref to the file structure, so we must 1392 * hold ->file_lock. 1393 */ 1394 spin_lock(&files->file_lock); 1395 file = fcheck_files(files, fd); 1396 if (!file) 1397 goto out_unlock; 1398 if (file->f_mode & 1) 1399 inode->i_mode |= S_IRUSR | S_IXUSR; 1400 if (file->f_mode & 2) 1401 inode->i_mode |= S_IWUSR | S_IXUSR; 1402 spin_unlock(&files->file_lock); 1403 put_files_struct(files); 1404 1405 inode->i_op = &proc_pid_link_inode_operations; 1406 inode->i_size = 64; 1407 ei->op.proc_get_link = proc_fd_link; 1408 dentry->d_op = &tid_fd_dentry_operations; 1409 d_add(dentry, inode); 1410 /* Close the race of the process dying before we return the dentry */ 1411 if (tid_fd_revalidate(dentry, NULL)) 1412 error = NULL; 1413 1414 out: 1415 return error; 1416out_unlock: 1417 spin_unlock(&files->file_lock); 1418 put_files_struct(files); 1419out_iput: 1420 iput(inode); 1421 goto out; 1422} 1423 1424static struct dentry *proc_lookupfd_common(struct inode *dir, 1425 struct dentry *dentry, 1426 instantiate_t instantiate) 1427{ 1428 struct task_struct *task = get_proc_task(dir); 1429 unsigned fd = name_to_int(dentry); 1430 struct dentry *result = ERR_PTR(-ENOENT); 1431 1432 if (!task) 1433 goto out_no_task; 1434 if (fd == ~0U) 1435 goto out; 1436 1437 result = instantiate(dir, dentry, task, &fd); 1438out: 1439 put_task_struct(task); 1440out_no_task: 1441 return result; 1442} 1443 1444static int proc_readfd_common(struct file * filp, void * dirent, 1445 filldir_t filldir, instantiate_t instantiate) 1446{ 1447 struct dentry *dentry = filp->f_path.dentry; 1448 struct inode *inode = dentry->d_inode; 1449 struct task_struct *p = get_proc_task(inode); 1450 unsigned int fd, tid, ino; 1451 int retval; 1452 struct files_struct * files; 1453 struct fdtable *fdt; 1454 1455 retval = -ENOENT; 1456 if (!p) 1457 goto out_no_task; 1458 retval = 0; 1459 tid = p->pid; 1460 1461 fd = filp->f_pos; 1462 switch (fd) { 1463 case 0: 1464 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0) 1465 goto out; 1466 filp->f_pos++; 1467 case 1: 1468 ino = parent_ino(dentry); 1469 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0) 1470 goto out; 1471 filp->f_pos++; 1472 default: 1473 files = get_files_struct(p); 1474 if (!files) 1475 goto out; 1476 rcu_read_lock(); 1477 fdt = files_fdtable(files); 1478 for (fd = filp->f_pos-2; 1479 fd < fdt->max_fds; 1480 fd++, filp->f_pos++) { 1481 char name[PROC_NUMBUF]; 1482 int len; 1483 1484 if (!fcheck_files(files, fd)) 1485 continue; 1486 rcu_read_unlock(); 1487 1488 len = snprintf(name, sizeof(name), "%d", fd); 1489 if (proc_fill_cache(filp, dirent, filldir, 1490 name, len, instantiate, 1491 p, &fd) < 0) { 1492 rcu_read_lock(); 1493 break; 1494 } 1495 rcu_read_lock(); 1496 } 1497 rcu_read_unlock(); 1498 put_files_struct(files); 1499 } 1500out: 1501 put_task_struct(p); 1502out_no_task: 1503 return retval; 1504} 1505 1506static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, 1507 struct nameidata *nd) 1508{ 1509 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); 1510} 1511 1512static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) 1513{ 1514 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); 1515} 1516 1517static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, 1518 size_t len, loff_t *ppos) 1519{ 1520 char tmp[PROC_FDINFO_MAX]; 1521 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, NULL, tmp); 1522 if (!err) 1523 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); 1524 return err; 1525} 1526 1527static const struct file_operations proc_fdinfo_file_operations = { 1528 .open = nonseekable_open, 1529 .read = proc_fdinfo_read, 1530}; 1531 1532static const struct file_operations proc_fd_operations = { 1533 .read = generic_read_dir, 1534 .readdir = proc_readfd, 1535}; 1536 1537/* 1538 * /proc/pid/fd needs a special permission handler so that a process can still 1539 * access /proc/self/fd after it has executed a setuid(). 1540 */ 1541static int proc_fd_permission(struct inode *inode, int mask, 1542 struct nameidata *nd) 1543{ 1544 int rv; 1545 1546 rv = generic_permission(inode, mask, NULL); 1547 if (rv == 0) 1548 return 0; 1549 if (task_pid(current) == proc_pid(inode)) 1550 rv = 0; 1551 return rv; 1552} 1553 1554/* 1555 * proc directories can do almost nothing.. 1556 */ 1557static const struct inode_operations proc_fd_inode_operations = { 1558 .lookup = proc_lookupfd, 1559 .permission = proc_fd_permission, 1560 .setattr = proc_setattr, 1561}; 1562 1563static struct dentry *proc_fdinfo_instantiate(struct inode *dir, 1564 struct dentry *dentry, struct task_struct *task, const void *ptr) 1565{ 1566 unsigned fd = *(unsigned *)ptr; 1567 struct inode *inode; 1568 struct proc_inode *ei; 1569 struct dentry *error = ERR_PTR(-ENOENT); 1570 1571 inode = proc_pid_make_inode(dir->i_sb, task); 1572 if (!inode) 1573 goto out; 1574 ei = PROC_I(inode); 1575 ei->fd = fd; 1576 inode->i_mode = S_IFREG | S_IRUSR; 1577 inode->i_fop = &proc_fdinfo_file_operations; 1578 dentry->d_op = &tid_fd_dentry_operations; 1579 d_add(dentry, inode); 1580 /* Close the race of the process dying before we return the dentry */ 1581 if (tid_fd_revalidate(dentry, NULL)) 1582 error = NULL; 1583 1584 out: 1585 return error; 1586} 1587 1588static struct dentry *proc_lookupfdinfo(struct inode *dir, 1589 struct dentry *dentry, 1590 struct nameidata *nd) 1591{ 1592 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); 1593} 1594 1595static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir) 1596{ 1597 return proc_readfd_common(filp, dirent, filldir, 1598 proc_fdinfo_instantiate); 1599} 1600 1601static const struct file_operations proc_fdinfo_operations = { 1602 .read = generic_read_dir, 1603 .readdir = proc_readfdinfo, 1604}; 1605 1606/* 1607 * proc directories can do almost nothing.. 1608 */ 1609static const struct inode_operations proc_fdinfo_inode_operations = { 1610 .lookup = proc_lookupfdinfo, 1611 .setattr = proc_setattr, 1612}; 1613 1614 1615static struct dentry *proc_pident_instantiate(struct inode *dir, 1616 struct dentry *dentry, struct task_struct *task, const void *ptr) 1617{ 1618 const struct pid_entry *p = ptr; 1619 struct inode *inode; 1620 struct proc_inode *ei; 1621 struct dentry *error = ERR_PTR(-EINVAL); 1622 1623 inode = proc_pid_make_inode(dir->i_sb, task); 1624 if (!inode) 1625 goto out; 1626 1627 ei = PROC_I(inode); 1628 inode->i_mode = p->mode; 1629 if (S_ISDIR(inode->i_mode)) 1630 inode->i_nlink = 2; /* Use getattr to fix if necessary */ 1631 if (p->iop) 1632 inode->i_op = p->iop; 1633 if (p->fop) 1634 inode->i_fop = p->fop; 1635 ei->op = p->op; 1636 dentry->d_op = &pid_dentry_operations; 1637 d_add(dentry, inode); 1638 /* Close the race of the process dying before we return the dentry */ 1639 if (pid_revalidate(dentry, NULL)) 1640 error = NULL; 1641out: 1642 return error; 1643} 1644 1645static struct dentry *proc_pident_lookup(struct inode *dir, 1646 struct dentry *dentry, 1647 const struct pid_entry *ents, 1648 unsigned int nents) 1649{ 1650 struct inode *inode; 1651 struct dentry *error; 1652 struct task_struct *task = get_proc_task(dir); 1653 const struct pid_entry *p, *last; 1654 1655 error = ERR_PTR(-ENOENT); 1656 inode = NULL; 1657 1658 if (!task) 1659 goto out_no_task; 1660 1661 /* 1662 * Yes, it does not scale. And it should not. Don't add 1663 * new entries into /proc/<tgid>/ without very good reasons. 1664 */ 1665 last = &ents[nents - 1]; 1666 for (p = ents; p <= last; p++) { 1667 if (p->len != dentry->d_name.len) 1668 continue; 1669 if (!memcmp(dentry->d_name.name, p->name, p->len)) 1670 break; 1671 } 1672 if (p > last) 1673 goto out; 1674 1675 error = proc_pident_instantiate(dir, dentry, task, p); 1676out: 1677 put_task_struct(task); 1678out_no_task: 1679 return error; 1680} 1681 1682static int proc_pident_fill_cache(struct file *filp, void *dirent, 1683 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 1684{ 1685 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 1686 proc_pident_instantiate, task, p); 1687} 1688 1689static int proc_pident_readdir(struct file *filp, 1690 void *dirent, filldir_t filldir, 1691 const struct pid_entry *ents, unsigned int nents) 1692{ 1693 int i; 1694 int pid; 1695 struct dentry *dentry = filp->f_path.dentry; 1696 struct inode *inode = dentry->d_inode; 1697 struct task_struct *task = get_proc_task(inode); 1698 const struct pid_entry *p, *last; 1699 ino_t ino; 1700 int ret; 1701 1702 ret = -ENOENT; 1703 if (!task) 1704 goto out_no_task; 1705 1706 ret = 0; 1707 pid = task->pid; 1708 i = filp->f_pos; 1709 switch (i) { 1710 case 0: 1711 ino = inode->i_ino; 1712 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 1713 goto out; 1714 i++; 1715 filp->f_pos++; 1716 /* fall through */ 1717 case 1: 1718 ino = parent_ino(dentry); 1719 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 1720 goto out; 1721 i++; 1722 filp->f_pos++; 1723 /* fall through */ 1724 default: 1725 i -= 2; 1726 if (i >= nents) { 1727 ret = 1; 1728 goto out; 1729 } 1730 p = ents + i; 1731 last = &ents[nents - 1]; 1732 while (p <= last) { 1733 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0) 1734 goto out; 1735 filp->f_pos++; 1736 p++; 1737 } 1738 } 1739 1740 ret = 1; 1741out: 1742 put_task_struct(task); 1743out_no_task: 1744 return ret; 1745} 1746 1747#ifdef CONFIG_SECURITY 1748static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, 1749 size_t count, loff_t *ppos) 1750{ 1751 struct inode * inode = file->f_path.dentry->d_inode; 1752 char *p = NULL; 1753 ssize_t length; 1754 struct task_struct *task = get_proc_task(inode); 1755 1756 if (!task) 1757 return -ESRCH; 1758 1759 length = security_getprocattr(task, 1760 (char*)file->f_path.dentry->d_name.name, 1761 &p); 1762 put_task_struct(task); 1763 if (length > 0) 1764 length = simple_read_from_buffer(buf, count, ppos, p, length); 1765 kfree(p); 1766 return length; 1767} 1768 1769static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, 1770 size_t count, loff_t *ppos) 1771{ 1772 struct inode * inode = file->f_path.dentry->d_inode; 1773 char *page; 1774 ssize_t length; 1775 struct task_struct *task = get_proc_task(inode); 1776 1777 length = -ESRCH; 1778 if (!task) 1779 goto out_no_task; 1780 if (count > PAGE_SIZE) 1781 count = PAGE_SIZE; 1782 1783 /* No partial writes. */ 1784 length = -EINVAL; 1785 if (*ppos != 0) 1786 goto out; 1787 1788 length = -ENOMEM; 1789 page = (char*)__get_free_page(GFP_USER); 1790 if (!page) 1791 goto out; 1792 1793 length = -EFAULT; 1794 if (copy_from_user(page, buf, count)) 1795 goto out_free; 1796 1797 length = security_setprocattr(task, 1798 (char*)file->f_path.dentry->d_name.name, 1799 (void*)page, count); 1800out_free: 1801 free_page((unsigned long) page); 1802out: 1803 put_task_struct(task); 1804out_no_task: 1805 return length; 1806} 1807 1808static const struct file_operations proc_pid_attr_operations = { 1809 .read = proc_pid_attr_read, 1810 .write = proc_pid_attr_write, 1811}; 1812 1813static const struct pid_entry attr_dir_stuff[] = { 1814 REG("current", S_IRUGO|S_IWUGO, pid_attr), 1815 REG("prev", S_IRUGO, pid_attr), 1816 REG("exec", S_IRUGO|S_IWUGO, pid_attr), 1817 REG("fscreate", S_IRUGO|S_IWUGO, pid_attr), 1818 REG("keycreate", S_IRUGO|S_IWUGO, pid_attr), 1819 REG("sockcreate", S_IRUGO|S_IWUGO, pid_attr), 1820}; 1821 1822static int proc_attr_dir_readdir(struct file * filp, 1823 void * dirent, filldir_t filldir) 1824{ 1825 return proc_pident_readdir(filp,dirent,filldir, 1826 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff)); 1827} 1828 1829static const struct file_operations proc_attr_dir_operations = { 1830 .read = generic_read_dir, 1831 .readdir = proc_attr_dir_readdir, 1832}; 1833 1834static struct dentry *proc_attr_dir_lookup(struct inode *dir, 1835 struct dentry *dentry, struct nameidata *nd) 1836{ 1837 return proc_pident_lookup(dir, dentry, 1838 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff)); 1839} 1840 1841static const struct inode_operations proc_attr_dir_inode_operations = { 1842 .lookup = proc_attr_dir_lookup, 1843 .getattr = pid_getattr, 1844 .setattr = proc_setattr, 1845}; 1846 1847#endif 1848 1849/* 1850 * /proc/self: 1851 */ 1852static int proc_self_readlink(struct dentry *dentry, char __user *buffer, 1853 int buflen) 1854{ 1855 char tmp[PROC_NUMBUF]; 1856 sprintf(tmp, "%d", current->tgid); 1857 return vfs_readlink(dentry,buffer,buflen,tmp); 1858} 1859 1860static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) 1861{ 1862 char tmp[PROC_NUMBUF]; 1863 sprintf(tmp, "%d", current->tgid); 1864 return ERR_PTR(vfs_follow_link(nd,tmp)); 1865} 1866 1867static const struct inode_operations proc_self_inode_operations = { 1868 .readlink = proc_self_readlink, 1869 .follow_link = proc_self_follow_link, 1870}; 1871 1872/* 1873 * proc base 1874 * 1875 * These are the directory entries in the root directory of /proc 1876 * that properly belong to the /proc filesystem, as they describe 1877 * describe something that is process related. 1878 */ 1879static const struct pid_entry proc_base_stuff[] = { 1880 NOD("self", S_IFLNK|S_IRWXUGO, 1881 &proc_self_inode_operations, NULL, {}), 1882}; 1883 1884/* 1885 * Exceptional case: normally we are not allowed to unhash a busy 1886 * directory. In this case, however, we can do it - no aliasing problems 1887 * due to the way we treat inodes. 1888 */ 1889static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) 1890{ 1891 struct inode *inode = dentry->d_inode; 1892 struct task_struct *task = get_proc_task(inode); 1893 if (task) { 1894 put_task_struct(task); 1895 return 1; 1896 } 1897 d_drop(dentry); 1898 return 0; 1899} 1900 1901static struct dentry_operations proc_base_dentry_operations = 1902{ 1903 .d_revalidate = proc_base_revalidate, 1904 .d_delete = pid_delete_dentry, 1905}; 1906 1907static struct dentry *proc_base_instantiate(struct inode *dir, 1908 struct dentry *dentry, struct task_struct *task, const void *ptr) 1909{ 1910 const struct pid_entry *p = ptr; 1911 struct inode *inode; 1912 struct proc_inode *ei; 1913 struct dentry *error = ERR_PTR(-EINVAL); 1914 1915 /* Allocate the inode */ 1916 error = ERR_PTR(-ENOMEM); 1917 inode = new_inode(dir->i_sb); 1918 if (!inode) 1919 goto out; 1920 1921 /* Initialize the inode */ 1922 ei = PROC_I(inode); 1923 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 1924 1925 /* 1926 * grab the reference to the task. 1927 */ 1928 ei->pid = get_task_pid(task, PIDTYPE_PID); 1929 if (!ei->pid) 1930 goto out_iput; 1931 1932 inode->i_uid = 0; 1933 inode->i_gid = 0; 1934 inode->i_mode = p->mode; 1935 if (S_ISDIR(inode->i_mode)) 1936 inode->i_nlink = 2; 1937 if (S_ISLNK(inode->i_mode)) 1938 inode->i_size = 64; 1939 if (p->iop) 1940 inode->i_op = p->iop; 1941 if (p->fop) 1942 inode->i_fop = p->fop; 1943 ei->op = p->op; 1944 dentry->d_op = &proc_base_dentry_operations; 1945 d_add(dentry, inode); 1946 error = NULL; 1947out: 1948 return error; 1949out_iput: 1950 iput(inode); 1951 goto out; 1952} 1953 1954static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) 1955{ 1956 struct dentry *error; 1957 struct task_struct *task = get_proc_task(dir); 1958 const struct pid_entry *p, *last; 1959 1960 error = ERR_PTR(-ENOENT); 1961 1962 if (!task) 1963 goto out_no_task; 1964 1965 /* Lookup the directory entry */ 1966 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; 1967 for (p = proc_base_stuff; p <= last; p++) { 1968 if (p->len != dentry->d_name.len) 1969 continue; 1970 if (!memcmp(dentry->d_name.name, p->name, p->len)) 1971 break; 1972 } 1973 if (p > last) 1974 goto out; 1975 1976 error = proc_base_instantiate(dir, dentry, task, p); 1977 1978out: 1979 put_task_struct(task); 1980out_no_task: 1981 return error; 1982} 1983 1984static int proc_base_fill_cache(struct file *filp, void *dirent, 1985 filldir_t filldir, struct task_struct *task, const struct pid_entry *p) 1986{ 1987 return proc_fill_cache(filp, dirent, filldir, p->name, p->len, 1988 proc_base_instantiate, task, p); 1989} 1990 1991#ifdef CONFIG_TASK_IO_ACCOUNTING 1992static int proc_pid_io_accounting(struct task_struct *task, char *buffer) 1993{ 1994 return sprintf(buffer, 1995#ifdef CONFIG_TASK_XACCT 1996 "rchar: %llu\n" 1997 "wchar: %llu\n" 1998 "syscr: %llu\n" 1999 "syscw: %llu\n" 2000#endif 2001 "read_bytes: %llu\n" 2002 "write_bytes: %llu\n" 2003 "cancelled_write_bytes: %llu\n", 2004#ifdef CONFIG_TASK_XACCT 2005 (unsigned long long)task->rchar, 2006 (unsigned long long)task->wchar, 2007 (unsigned long long)task->syscr, 2008 (unsigned long long)task->syscw, 2009#endif 2010 (unsigned long long)task->ioac.read_bytes, 2011 (unsigned long long)task->ioac.write_bytes, 2012 (unsigned long long)task->ioac.cancelled_write_bytes); 2013} 2014#endif 2015 2016/* 2017 * Thread groups 2018 */ 2019static const struct file_operations proc_task_operations; 2020static const struct inode_operations proc_task_inode_operations; 2021 2022static const struct pid_entry tgid_base_stuff[] = { 2023 DIR("task", S_IRUGO|S_IXUGO, task), 2024 DIR("fd", S_IRUSR|S_IXUSR, fd), 2025 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), 2026 INF("environ", S_IRUSR, pid_environ), 2027 INF("auxv", S_IRUSR, pid_auxv), 2028 INF("status", S_IRUGO, pid_status), 2029#ifdef CONFIG_SCHED_DEBUG 2030 REG("sched", S_IRUGO|S_IWUSR, pid_sched), 2031#endif 2032 INF("cmdline", S_IRUGO, pid_cmdline), 2033 INF("stat", S_IRUGO, tgid_stat), 2034 INF("statm", S_IRUGO, pid_statm), 2035 REG("maps", S_IRUGO, maps), 2036#ifdef CONFIG_NUMA 2037 REG("numa_maps", S_IRUGO, numa_maps), 2038#endif 2039 REG("mem", S_IRUSR|S_IWUSR, mem), 2040#ifdef CONFIG_SECCOMP 2041 REG("seccomp", S_IRUSR|S_IWUSR, seccomp), 2042#endif 2043 LNK("cwd", cwd), 2044 LNK("root", root), 2045 LNK("exe", exe), 2046 REG("mounts", S_IRUGO, mounts), 2047 REG("mountstats", S_IRUSR, mountstats), 2048#ifdef CONFIG_MMU 2049 REG("clear_refs", S_IWUSR, clear_refs), 2050 REG("smaps", S_IRUGO, smaps), 2051#endif 2052#ifdef CONFIG_SECURITY 2053 DIR("attr", S_IRUGO|S_IXUGO, attr_dir), 2054#endif 2055#ifdef CONFIG_KALLSYMS 2056 INF("wchan", S_IRUGO, pid_wchan), 2057#endif 2058#ifdef CONFIG_SCHEDSTATS 2059 INF("schedstat", S_IRUGO, pid_schedstat), 2060#endif 2061#ifdef CONFIG_CPUSETS 2062 REG("cpuset", S_IRUGO, cpuset), 2063#endif 2064 INF("oom_score", S_IRUGO, oom_score), 2065 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust), 2066#ifdef CONFIG_AUDITSYSCALL 2067 REG("loginuid", S_IWUSR|S_IRUGO, loginuid), 2068#endif 2069#ifdef CONFIG_FAULT_INJECTION 2070 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject), 2071#endif 2072#ifdef CONFIG_TASK_IO_ACCOUNTING 2073 INF("io", S_IRUGO, pid_io_accounting), 2074#endif 2075}; 2076 2077static int proc_tgid_base_readdir(struct file * filp, 2078 void * dirent, filldir_t filldir) 2079{ 2080 return proc_pident_readdir(filp,dirent,filldir, 2081 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff)); 2082} 2083 2084static const struct file_operations proc_tgid_base_operations = { 2085 .read = generic_read_dir, 2086 .readdir = proc_tgid_base_readdir, 2087}; 2088 2089static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2090 return proc_pident_lookup(dir, dentry, 2091 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); 2092} 2093 2094static const struct inode_operations proc_tgid_base_inode_operations = { 2095 .lookup = proc_tgid_base_lookup, 2096 .getattr = pid_getattr, 2097 .setattr = proc_setattr, 2098}; 2099 2100/** 2101 * proc_flush_task - Remove dcache entries for @task from the /proc dcache. 2102 * 2103 * @task: task that should be flushed. 2104 * 2105 * Looks in the dcache for 2106 * /proc/@pid 2107 * /proc/@tgid/task/@pid 2108 * if either directory is present flushes it and all of it'ts children 2109 * from the dcache. 2110 * 2111 * It is safe and reasonable to cache /proc entries for a task until 2112 * that task exits. After that they just clog up the dcache with 2113 * useless entries, possibly causing useful dcache entries to be 2114 * flushed instead. This routine is proved to flush those useless 2115 * dcache entries at process exit time. 2116 * 2117 * NOTE: This routine is just an optimization so it does not guarantee 2118 * that no dcache entries will exist at process exit time it 2119 * just makes it very unlikely that any will persist. 2120 */ 2121void proc_flush_task(struct task_struct *task) 2122{ 2123 struct dentry *dentry, *leader, *dir; 2124 char buf[PROC_NUMBUF]; 2125 struct qstr name; 2126 2127 name.name = buf; 2128 name.len = snprintf(buf, sizeof(buf), "%d", task->pid); 2129 dentry = d_hash_and_lookup(proc_mnt->mnt_root, &name); 2130 if (dentry) { 2131 shrink_dcache_parent(dentry); 2132 d_drop(dentry); 2133 dput(dentry); 2134 } 2135 2136 if (thread_group_leader(task)) 2137 goto out; 2138 2139 name.name = buf; 2140 name.len = snprintf(buf, sizeof(buf), "%d", task->tgid); 2141 leader = d_hash_and_lookup(proc_mnt->mnt_root, &name); 2142 if (!leader) 2143 goto out; 2144 2145 name.name = "task"; 2146 name.len = strlen(name.name); 2147 dir = d_hash_and_lookup(leader, &name); 2148 if (!dir) 2149 goto out_put_leader; 2150 2151 name.name = buf; 2152 name.len = snprintf(buf, sizeof(buf), "%d", task->pid); 2153 dentry = d_hash_and_lookup(dir, &name); 2154 if (dentry) { 2155 shrink_dcache_parent(dentry); 2156 d_drop(dentry); 2157 dput(dentry); 2158 } 2159 2160 dput(dir); 2161out_put_leader: 2162 dput(leader); 2163out: 2164 return; 2165} 2166 2167static struct dentry *proc_pid_instantiate(struct inode *dir, 2168 struct dentry * dentry, 2169 struct task_struct *task, const void *ptr) 2170{ 2171 struct dentry *error = ERR_PTR(-ENOENT); 2172 struct inode *inode; 2173 2174 inode = proc_pid_make_inode(dir->i_sb, task); 2175 if (!inode) 2176 goto out; 2177 2178 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2179 inode->i_op = &proc_tgid_base_inode_operations; 2180 inode->i_fop = &proc_tgid_base_operations; 2181 inode->i_flags|=S_IMMUTABLE; 2182 inode->i_nlink = 5; 2183#ifdef CONFIG_SECURITY 2184 inode->i_nlink += 1; 2185#endif 2186 2187 dentry->d_op = &pid_dentry_operations; 2188 2189 d_add(dentry, inode); 2190 /* Close the race of the process dying before we return the dentry */ 2191 if (pid_revalidate(dentry, NULL)) 2192 error = NULL; 2193out: 2194 return error; 2195} 2196 2197struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2198{ 2199 struct dentry *result = ERR_PTR(-ENOENT); 2200 struct task_struct *task; 2201 unsigned tgid; 2202 2203 result = proc_base_lookup(dir, dentry); 2204 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) 2205 goto out; 2206 2207 tgid = name_to_int(dentry); 2208 if (tgid == ~0U) 2209 goto out; 2210 2211 rcu_read_lock(); 2212 task = find_task_by_pid(tgid); 2213 if (task) 2214 get_task_struct(task); 2215 rcu_read_unlock(); 2216 if (!task) 2217 goto out; 2218 2219 result = proc_pid_instantiate(dir, dentry, task, NULL); 2220 put_task_struct(task); 2221out: 2222 return result; 2223} 2224 2225/* 2226 * Find the first task with tgid >= tgid 2227 * 2228 */ 2229static struct task_struct *next_tgid(unsigned int tgid) 2230{ 2231 struct task_struct *task; 2232 struct pid *pid; 2233 2234 rcu_read_lock(); 2235retry: 2236 task = NULL; 2237 pid = find_ge_pid(tgid); 2238 if (pid) { 2239 tgid = pid->nr + 1; 2240 task = pid_task(pid, PIDTYPE_PID); 2241 /* What we to know is if the pid we have find is the 2242 * pid of a thread_group_leader. Testing for task 2243 * being a thread_group_leader is the obvious thing 2244 * todo but there is a window when it fails, due to 2245 * the pid transfer logic in de_thread. 2246 * 2247 * So we perform the straight forward test of seeing 2248 * if the pid we have found is the pid of a thread 2249 * group leader, and don't worry if the task we have 2250 * found doesn't happen to be a thread group leader. 2251 * As we don't care in the case of readdir. 2252 */ 2253 if (!task || !has_group_leader_pid(task)) 2254 goto retry; 2255 get_task_struct(task); 2256 } 2257 rcu_read_unlock(); 2258 return task; 2259} 2260 2261#define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) 2262 2263static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2264 struct task_struct *task, int tgid) 2265{ 2266 char name[PROC_NUMBUF]; 2267 int len = snprintf(name, sizeof(name), "%d", tgid); 2268 return proc_fill_cache(filp, dirent, filldir, name, len, 2269 proc_pid_instantiate, task, NULL); 2270} 2271 2272/* for the /proc/ directory itself, after non-process stuff has been done */ 2273int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) 2274{ 2275 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; 2276 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode); 2277 struct task_struct *task; 2278 int tgid; 2279 2280 if (!reaper) 2281 goto out_no_task; 2282 2283 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { 2284 const struct pid_entry *p = &proc_base_stuff[nr]; 2285 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) 2286 goto out; 2287 } 2288 2289 tgid = filp->f_pos - TGID_OFFSET; 2290 for (task = next_tgid(tgid); 2291 task; 2292 put_task_struct(task), task = next_tgid(tgid + 1)) { 2293 tgid = task->pid; 2294 filp->f_pos = tgid + TGID_OFFSET; 2295 if (proc_pid_fill_cache(filp, dirent, filldir, task, tgid) < 0) { 2296 put_task_struct(task); 2297 goto out; 2298 } 2299 } 2300 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET; 2301out: 2302 put_task_struct(reaper); 2303out_no_task: 2304 return 0; 2305} 2306 2307/* 2308 * Tasks 2309 */ 2310static const struct pid_entry tid_base_stuff[] = { 2311 DIR("fd", S_IRUSR|S_IXUSR, fd), 2312 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo), 2313 INF("environ", S_IRUSR, pid_environ), 2314 INF("auxv", S_IRUSR, pid_auxv), 2315 INF("status", S_IRUGO, pid_status), 2316#ifdef CONFIG_SCHED_DEBUG 2317 REG("sched", S_IRUGO|S_IWUSR, pid_sched), 2318#endif 2319 INF("cmdline", S_IRUGO, pid_cmdline), 2320 INF("stat", S_IRUGO, tid_stat), 2321 INF("statm", S_IRUGO, pid_statm), 2322 REG("maps", S_IRUGO, maps), 2323#ifdef CONFIG_NUMA 2324 REG("numa_maps", S_IRUGO, numa_maps), 2325#endif 2326 REG("mem", S_IRUSR|S_IWUSR, mem), 2327#ifdef CONFIG_SECCOMP 2328 REG("seccomp", S_IRUSR|S_IWUSR, seccomp), 2329#endif 2330 LNK("cwd", cwd), 2331 LNK("root", root), 2332 LNK("exe", exe), 2333 REG("mounts", S_IRUGO, mounts), 2334#ifdef CONFIG_MMU 2335 REG("clear_refs", S_IWUSR, clear_refs), 2336 REG("smaps", S_IRUGO, smaps), 2337#endif 2338#ifdef CONFIG_SECURITY 2339 DIR("attr", S_IRUGO|S_IXUGO, attr_dir), 2340#endif 2341#ifdef CONFIG_KALLSYMS 2342 INF("wchan", S_IRUGO, pid_wchan), 2343#endif 2344#ifdef CONFIG_SCHEDSTATS 2345 INF("schedstat", S_IRUGO, pid_schedstat), 2346#endif 2347#ifdef CONFIG_CPUSETS 2348 REG("cpuset", S_IRUGO, cpuset), 2349#endif 2350 INF("oom_score", S_IRUGO, oom_score), 2351 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust), 2352#ifdef CONFIG_AUDITSYSCALL 2353 REG("loginuid", S_IWUSR|S_IRUGO, loginuid), 2354#endif 2355#ifdef CONFIG_FAULT_INJECTION 2356 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject), 2357#endif 2358}; 2359 2360static int proc_tid_base_readdir(struct file * filp, 2361 void * dirent, filldir_t filldir) 2362{ 2363 return proc_pident_readdir(filp,dirent,filldir, 2364 tid_base_stuff,ARRAY_SIZE(tid_base_stuff)); 2365} 2366 2367static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ 2368 return proc_pident_lookup(dir, dentry, 2369 tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); 2370} 2371 2372static const struct file_operations proc_tid_base_operations = { 2373 .read = generic_read_dir, 2374 .readdir = proc_tid_base_readdir, 2375}; 2376 2377static const struct inode_operations proc_tid_base_inode_operations = { 2378 .lookup = proc_tid_base_lookup, 2379 .getattr = pid_getattr, 2380 .setattr = proc_setattr, 2381}; 2382 2383static struct dentry *proc_task_instantiate(struct inode *dir, 2384 struct dentry *dentry, struct task_struct *task, const void *ptr) 2385{ 2386 struct dentry *error = ERR_PTR(-ENOENT); 2387 struct inode *inode; 2388 inode = proc_pid_make_inode(dir->i_sb, task); 2389 2390 if (!inode) 2391 goto out; 2392 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO; 2393 inode->i_op = &proc_tid_base_inode_operations; 2394 inode->i_fop = &proc_tid_base_operations; 2395 inode->i_flags|=S_IMMUTABLE; 2396 inode->i_nlink = 4; 2397#ifdef CONFIG_SECURITY 2398 inode->i_nlink += 1; 2399#endif 2400 2401 dentry->d_op = &pid_dentry_operations; 2402 2403 d_add(dentry, inode); 2404 /* Close the race of the process dying before we return the dentry */ 2405 if (pid_revalidate(dentry, NULL)) 2406 error = NULL; 2407out: 2408 return error; 2409} 2410 2411static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 2412{ 2413 struct dentry *result = ERR_PTR(-ENOENT); 2414 struct task_struct *task; 2415 struct task_struct *leader = get_proc_task(dir); 2416 unsigned tid; 2417 2418 if (!leader) 2419 goto out_no_task; 2420 2421 tid = name_to_int(dentry); 2422 if (tid == ~0U) 2423 goto out; 2424 2425 rcu_read_lock(); 2426 task = find_task_by_pid(tid); 2427 if (task) 2428 get_task_struct(task); 2429 rcu_read_unlock(); 2430 if (!task) 2431 goto out; 2432 if (leader->tgid != task->tgid) 2433 goto out_drop_task; 2434 2435 result = proc_task_instantiate(dir, dentry, task, NULL); 2436out_drop_task: 2437 put_task_struct(task); 2438out: 2439 put_task_struct(leader); 2440out_no_task: 2441 return result; 2442} 2443 2444/* 2445 * Find the first tid of a thread group to return to user space. 2446 * 2447 * Usually this is just the thread group leader, but if the users 2448 * buffer was too small or there was a seek into the middle of the 2449 * directory we have more work todo. 2450 * 2451 * In the case of a short read we start with find_task_by_pid. 2452 * 2453 * In the case of a seek we start with the leader and walk nr 2454 * threads past it. 2455 */ 2456static struct task_struct *first_tid(struct task_struct *leader, 2457 int tid, int nr) 2458{ 2459 struct task_struct *pos; 2460 2461 rcu_read_lock(); 2462 /* Attempt to start with the pid of a thread */ 2463 if (tid && (nr > 0)) { 2464 pos = find_task_by_pid(tid); 2465 if (pos && (pos->group_leader == leader)) 2466 goto found; 2467 } 2468 2469 /* If nr exceeds the number of threads there is nothing todo */ 2470 pos = NULL; 2471 if (nr && nr >= get_nr_threads(leader)) 2472 goto out; 2473 2474 /* If we haven't found our starting place yet start 2475 * with the leader and walk nr threads forward. 2476 */ 2477 for (pos = leader; nr > 0; --nr) { 2478 pos = next_thread(pos); 2479 if (pos == leader) { 2480 pos = NULL; 2481 goto out; 2482 } 2483 } 2484found: 2485 get_task_struct(pos); 2486out: 2487 rcu_read_unlock(); 2488 return pos; 2489} 2490 2491/* 2492 * Find the next thread in the thread list. 2493 * Return NULL if there is an error or no next thread. 2494 * 2495 * The reference to the input task_struct is released. 2496 */ 2497static struct task_struct *next_tid(struct task_struct *start) 2498{ 2499 struct task_struct *pos = NULL; 2500 rcu_read_lock(); 2501 if (pid_alive(start)) { 2502 pos = next_thread(start); 2503 if (thread_group_leader(pos)) 2504 pos = NULL; 2505 else 2506 get_task_struct(pos); 2507 } 2508 rcu_read_unlock(); 2509 put_task_struct(start); 2510 return pos; 2511} 2512 2513static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir, 2514 struct task_struct *task, int tid) 2515{ 2516 char name[PROC_NUMBUF]; 2517 int len = snprintf(name, sizeof(name), "%d", tid); 2518 return proc_fill_cache(filp, dirent, filldir, name, len, 2519 proc_task_instantiate, task, NULL); 2520} 2521 2522/* for the /proc/TGID/task/ directories */ 2523static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir) 2524{ 2525 struct dentry *dentry = filp->f_path.dentry; 2526 struct inode *inode = dentry->d_inode; 2527 struct task_struct *leader = NULL; 2528 struct task_struct *task; 2529 int retval = -ENOENT; 2530 ino_t ino; 2531 int tid; 2532 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */ 2533 2534 task = get_proc_task(inode); 2535 if (!task) 2536 goto out_no_task; 2537 rcu_read_lock(); 2538 if (pid_alive(task)) { 2539 leader = task->group_leader; 2540 get_task_struct(leader); 2541 } 2542 rcu_read_unlock(); 2543 put_task_struct(task); 2544 if (!leader) 2545 goto out_no_task; 2546 retval = 0; 2547 2548 switch (pos) { 2549 case 0: 2550 ino = inode->i_ino; 2551 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0) 2552 goto out; 2553 pos++; 2554 /* fall through */ 2555 case 1: 2556 ino = parent_ino(dentry); 2557 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0) 2558 goto out; 2559 pos++; 2560 /* fall through */ 2561 } 2562 2563 /* f_version caches the tgid value that the last readdir call couldn't 2564 * return. lseek aka telldir automagically resets f_version to 0. 2565 */ 2566 tid = filp->f_version; 2567 filp->f_version = 0; 2568 for (task = first_tid(leader, tid, pos - 2); 2569 task; 2570 task = next_tid(task), pos++) { 2571 tid = task->pid; 2572 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) { 2573 /* returning this tgid failed, save it as the first 2574 * pid for the next readir call */ 2575 filp->f_version = tid; 2576 put_task_struct(task); 2577 break; 2578 } 2579 } 2580out: 2581 filp->f_pos = pos; 2582 put_task_struct(leader); 2583out_no_task: 2584 return retval; 2585} 2586 2587static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 2588{ 2589 struct inode *inode = dentry->d_inode; 2590 struct task_struct *p = get_proc_task(inode); 2591 generic_fillattr(inode, stat); 2592 2593 if (p) { 2594 rcu_read_lock(); 2595 stat->nlink += get_nr_threads(p); 2596 rcu_read_unlock(); 2597 put_task_struct(p); 2598 } 2599 2600 return 0; 2601} 2602 2603static const struct inode_operations proc_task_inode_operations = { 2604 .lookup = proc_task_lookup, 2605 .getattr = proc_task_getattr, 2606 .setattr = proc_setattr, 2607}; 2608 2609static const struct file_operations proc_task_operations = { 2610 .read = generic_read_dir, 2611 .readdir = proc_task_readdir, 2612}; 2613