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![Al Viro](/assets/img/avatar_default.png)
... and clean the unsigned-f_pos code, while we are at it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
948 lines
21 KiB
C
948 lines
21 KiB
C
/*
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* linux/fs/read_write.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*/
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#include <linux/slab.h>
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#include <linux/stat.h>
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#include <linux/fcntl.h>
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#include <linux/file.h>
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#include <linux/uio.h>
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#include <linux/fsnotify.h>
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#include <linux/security.h>
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#include <linux/module.h>
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#include <linux/syscalls.h>
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#include <linux/pagemap.h>
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#include <linux/splice.h>
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#include "read_write.h"
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#include <asm/uaccess.h>
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#include <asm/unistd.h>
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const struct file_operations generic_ro_fops = {
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.llseek = generic_file_llseek,
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.read = do_sync_read,
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.aio_read = generic_file_aio_read,
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.mmap = generic_file_readonly_mmap,
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.splice_read = generic_file_splice_read,
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};
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EXPORT_SYMBOL(generic_ro_fops);
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static inline int unsigned_offsets(struct file *file)
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{
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return file->f_mode & FMODE_UNSIGNED_OFFSET;
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}
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/**
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* generic_file_llseek_unlocked - lockless generic llseek implementation
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* @file: file structure to seek on
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* @offset: file offset to seek to
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* @origin: type of seek
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*
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* Updates the file offset to the value specified by @offset and @origin.
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* Locking must be provided by the caller.
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*/
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loff_t
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generic_file_llseek_unlocked(struct file *file, loff_t offset, int origin)
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{
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struct inode *inode = file->f_mapping->host;
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switch (origin) {
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case SEEK_END:
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offset += inode->i_size;
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break;
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case SEEK_CUR:
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/*
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* Here we special-case the lseek(fd, 0, SEEK_CUR)
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* position-querying operation. Avoid rewriting the "same"
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* f_pos value back to the file because a concurrent read(),
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* write() or lseek() might have altered it
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*/
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if (offset == 0)
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return file->f_pos;
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offset += file->f_pos;
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break;
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}
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if (offset < 0 && !unsigned_offsets(file))
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return -EINVAL;
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if (offset > inode->i_sb->s_maxbytes)
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return -EINVAL;
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/* Special lock needed here? */
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if (offset != file->f_pos) {
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file->f_pos = offset;
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file->f_version = 0;
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}
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return offset;
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}
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EXPORT_SYMBOL(generic_file_llseek_unlocked);
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/**
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* generic_file_llseek - generic llseek implementation for regular files
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* @file: file structure to seek on
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* @offset: file offset to seek to
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* @origin: type of seek
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*
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* This is a generic implemenation of ->llseek useable for all normal local
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* filesystems. It just updates the file offset to the value specified by
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* @offset and @origin under i_mutex.
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*/
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loff_t generic_file_llseek(struct file *file, loff_t offset, int origin)
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{
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loff_t rval;
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mutex_lock(&file->f_dentry->d_inode->i_mutex);
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rval = generic_file_llseek_unlocked(file, offset, origin);
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mutex_unlock(&file->f_dentry->d_inode->i_mutex);
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return rval;
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}
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EXPORT_SYMBOL(generic_file_llseek);
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/**
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* noop_llseek - No Operation Performed llseek implementation
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* @file: file structure to seek on
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* @offset: file offset to seek to
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* @origin: type of seek
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*
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* This is an implementation of ->llseek useable for the rare special case when
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* userspace expects the seek to succeed but the (device) file is actually not
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* able to perform the seek. In this case you use noop_llseek() instead of
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* falling back to the default implementation of ->llseek.
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*/
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loff_t noop_llseek(struct file *file, loff_t offset, int origin)
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{
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return file->f_pos;
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}
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EXPORT_SYMBOL(noop_llseek);
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loff_t no_llseek(struct file *file, loff_t offset, int origin)
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{
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return -ESPIPE;
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}
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EXPORT_SYMBOL(no_llseek);
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loff_t default_llseek(struct file *file, loff_t offset, int origin)
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{
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loff_t retval;
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mutex_lock(&file->f_dentry->d_inode->i_mutex);
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switch (origin) {
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case SEEK_END:
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offset += i_size_read(file->f_path.dentry->d_inode);
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break;
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case SEEK_CUR:
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if (offset == 0) {
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retval = file->f_pos;
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goto out;
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}
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offset += file->f_pos;
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}
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retval = -EINVAL;
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if (offset >= 0 || unsigned_offsets(file)) {
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if (offset != file->f_pos) {
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file->f_pos = offset;
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file->f_version = 0;
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}
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retval = offset;
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}
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out:
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mutex_unlock(&file->f_dentry->d_inode->i_mutex);
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return retval;
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}
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EXPORT_SYMBOL(default_llseek);
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loff_t vfs_llseek(struct file *file, loff_t offset, int origin)
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{
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loff_t (*fn)(struct file *, loff_t, int);
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fn = no_llseek;
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if (file->f_mode & FMODE_LSEEK) {
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if (file->f_op && file->f_op->llseek)
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fn = file->f_op->llseek;
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}
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return fn(file, offset, origin);
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}
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EXPORT_SYMBOL(vfs_llseek);
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SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, origin)
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{
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off_t retval;
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struct file * file;
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int fput_needed;
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retval = -EBADF;
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file = fget_light(fd, &fput_needed);
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if (!file)
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goto bad;
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retval = -EINVAL;
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if (origin <= SEEK_MAX) {
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loff_t res = vfs_llseek(file, offset, origin);
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retval = res;
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if (res != (loff_t)retval)
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retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */
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}
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fput_light(file, fput_needed);
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bad:
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return retval;
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}
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#ifdef __ARCH_WANT_SYS_LLSEEK
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SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high,
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unsigned long, offset_low, loff_t __user *, result,
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unsigned int, origin)
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{
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int retval;
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struct file * file;
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loff_t offset;
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int fput_needed;
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retval = -EBADF;
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file = fget_light(fd, &fput_needed);
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if (!file)
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goto bad;
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retval = -EINVAL;
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if (origin > SEEK_MAX)
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goto out_putf;
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offset = vfs_llseek(file, ((loff_t) offset_high << 32) | offset_low,
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origin);
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retval = (int)offset;
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if (offset >= 0) {
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retval = -EFAULT;
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if (!copy_to_user(result, &offset, sizeof(offset)))
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retval = 0;
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}
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out_putf:
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fput_light(file, fput_needed);
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bad:
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return retval;
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}
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#endif
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/*
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* rw_verify_area doesn't like huge counts. We limit
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* them to something that fits in "int" so that others
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* won't have to do range checks all the time.
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*/
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int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count)
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{
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struct inode *inode;
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loff_t pos;
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int retval = -EINVAL;
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inode = file->f_path.dentry->d_inode;
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if (unlikely((ssize_t) count < 0))
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return retval;
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pos = *ppos;
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if (unlikely(pos < 0)) {
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if (!unsigned_offsets(file))
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return retval;
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if (count >= -pos) /* both values are in 0..LLONG_MAX */
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return -EOVERFLOW;
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} else if (unlikely((loff_t) (pos + count) < 0)) {
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if (!unsigned_offsets(file))
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return retval;
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}
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if (unlikely(inode->i_flock && mandatory_lock(inode))) {
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retval = locks_mandatory_area(
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read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE,
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inode, file, pos, count);
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if (retval < 0)
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return retval;
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}
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retval = security_file_permission(file,
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read_write == READ ? MAY_READ : MAY_WRITE);
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if (retval)
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return retval;
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return count > MAX_RW_COUNT ? MAX_RW_COUNT : count;
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}
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static void wait_on_retry_sync_kiocb(struct kiocb *iocb)
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{
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set_current_state(TASK_UNINTERRUPTIBLE);
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if (!kiocbIsKicked(iocb))
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schedule();
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else
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kiocbClearKicked(iocb);
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__set_current_state(TASK_RUNNING);
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}
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ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
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{
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struct iovec iov = { .iov_base = buf, .iov_len = len };
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struct kiocb kiocb;
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ssize_t ret;
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init_sync_kiocb(&kiocb, filp);
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kiocb.ki_pos = *ppos;
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kiocb.ki_left = len;
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kiocb.ki_nbytes = len;
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for (;;) {
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ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos);
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if (ret != -EIOCBRETRY)
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break;
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wait_on_retry_sync_kiocb(&kiocb);
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}
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if (-EIOCBQUEUED == ret)
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ret = wait_on_sync_kiocb(&kiocb);
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*ppos = kiocb.ki_pos;
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return ret;
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}
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EXPORT_SYMBOL(do_sync_read);
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ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
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{
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ssize_t ret;
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if (!(file->f_mode & FMODE_READ))
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return -EBADF;
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if (!file->f_op || (!file->f_op->read && !file->f_op->aio_read))
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return -EINVAL;
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if (unlikely(!access_ok(VERIFY_WRITE, buf, count)))
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return -EFAULT;
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ret = rw_verify_area(READ, file, pos, count);
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if (ret >= 0) {
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count = ret;
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if (file->f_op->read)
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ret = file->f_op->read(file, buf, count, pos);
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else
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ret = do_sync_read(file, buf, count, pos);
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if (ret > 0) {
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fsnotify_access(file);
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add_rchar(current, ret);
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}
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inc_syscr(current);
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}
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return ret;
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}
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EXPORT_SYMBOL(vfs_read);
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ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
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{
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struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
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struct kiocb kiocb;
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ssize_t ret;
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init_sync_kiocb(&kiocb, filp);
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kiocb.ki_pos = *ppos;
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kiocb.ki_left = len;
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kiocb.ki_nbytes = len;
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for (;;) {
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ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos);
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if (ret != -EIOCBRETRY)
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break;
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wait_on_retry_sync_kiocb(&kiocb);
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}
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if (-EIOCBQUEUED == ret)
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ret = wait_on_sync_kiocb(&kiocb);
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*ppos = kiocb.ki_pos;
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return ret;
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}
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EXPORT_SYMBOL(do_sync_write);
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ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
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{
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ssize_t ret;
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if (!(file->f_mode & FMODE_WRITE))
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return -EBADF;
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if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write))
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return -EINVAL;
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if (unlikely(!access_ok(VERIFY_READ, buf, count)))
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return -EFAULT;
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ret = rw_verify_area(WRITE, file, pos, count);
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if (ret >= 0) {
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count = ret;
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if (file->f_op->write)
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ret = file->f_op->write(file, buf, count, pos);
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else
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ret = do_sync_write(file, buf, count, pos);
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if (ret > 0) {
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fsnotify_modify(file);
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add_wchar(current, ret);
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}
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inc_syscw(current);
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}
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return ret;
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}
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EXPORT_SYMBOL(vfs_write);
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static inline loff_t file_pos_read(struct file *file)
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{
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return file->f_pos;
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}
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static inline void file_pos_write(struct file *file, loff_t pos)
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{
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file->f_pos = pos;
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}
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SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
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{
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struct file *file;
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ssize_t ret = -EBADF;
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int fput_needed;
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file = fget_light(fd, &fput_needed);
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if (file) {
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loff_t pos = file_pos_read(file);
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ret = vfs_read(file, buf, count, &pos);
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file_pos_write(file, pos);
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fput_light(file, fput_needed);
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}
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return ret;
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}
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SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
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size_t, count)
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{
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struct file *file;
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ssize_t ret = -EBADF;
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int fput_needed;
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file = fget_light(fd, &fput_needed);
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if (file) {
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loff_t pos = file_pos_read(file);
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ret = vfs_write(file, buf, count, &pos);
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file_pos_write(file, pos);
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fput_light(file, fput_needed);
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}
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return ret;
|
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}
|
|
|
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SYSCALL_DEFINE(pread64)(unsigned int fd, char __user *buf,
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size_t count, loff_t pos)
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{
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struct file *file;
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ssize_t ret = -EBADF;
|
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int fput_needed;
|
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|
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if (pos < 0)
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return -EINVAL;
|
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|
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file = fget_light(fd, &fput_needed);
|
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if (file) {
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ret = -ESPIPE;
|
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if (file->f_mode & FMODE_PREAD)
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ret = vfs_read(file, buf, count, &pos);
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fput_light(file, fput_needed);
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}
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|
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return ret;
|
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}
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#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
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asmlinkage long SyS_pread64(long fd, long buf, long count, loff_t pos)
|
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{
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return SYSC_pread64((unsigned int) fd, (char __user *) buf,
|
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(size_t) count, pos);
|
|
}
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SYSCALL_ALIAS(sys_pread64, SyS_pread64);
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#endif
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|
|
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SYSCALL_DEFINE(pwrite64)(unsigned int fd, const char __user *buf,
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size_t count, loff_t pos)
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{
|
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struct file *file;
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ssize_t ret = -EBADF;
|
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int fput_needed;
|
|
|
|
if (pos < 0)
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return -EINVAL;
|
|
|
|
file = fget_light(fd, &fput_needed);
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|
if (file) {
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ret = -ESPIPE;
|
|
if (file->f_mode & FMODE_PWRITE)
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ret = vfs_write(file, buf, count, &pos);
|
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fput_light(file, fput_needed);
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|
}
|
|
|
|
return ret;
|
|
}
|
|
#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
|
|
asmlinkage long SyS_pwrite64(long fd, long buf, long count, loff_t pos)
|
|
{
|
|
return SYSC_pwrite64((unsigned int) fd, (const char __user *) buf,
|
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(size_t) count, pos);
|
|
}
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|
SYSCALL_ALIAS(sys_pwrite64, SyS_pwrite64);
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|
#endif
|
|
|
|
/*
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|
* Reduce an iovec's length in-place. Return the resulting number of segments
|
|
*/
|
|
unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to)
|
|
{
|
|
unsigned long seg = 0;
|
|
size_t len = 0;
|
|
|
|
while (seg < nr_segs) {
|
|
seg++;
|
|
if (len + iov->iov_len >= to) {
|
|
iov->iov_len = to - len;
|
|
break;
|
|
}
|
|
len += iov->iov_len;
|
|
iov++;
|
|
}
|
|
return seg;
|
|
}
|
|
EXPORT_SYMBOL(iov_shorten);
|
|
|
|
ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov,
|
|
unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn)
|
|
{
|
|
struct kiocb kiocb;
|
|
ssize_t ret;
|
|
|
|
init_sync_kiocb(&kiocb, filp);
|
|
kiocb.ki_pos = *ppos;
|
|
kiocb.ki_left = len;
|
|
kiocb.ki_nbytes = len;
|
|
|
|
for (;;) {
|
|
ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos);
|
|
if (ret != -EIOCBRETRY)
|
|
break;
|
|
wait_on_retry_sync_kiocb(&kiocb);
|
|
}
|
|
|
|
if (ret == -EIOCBQUEUED)
|
|
ret = wait_on_sync_kiocb(&kiocb);
|
|
*ppos = kiocb.ki_pos;
|
|
return ret;
|
|
}
|
|
|
|
/* Do it by hand, with file-ops */
|
|
ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov,
|
|
unsigned long nr_segs, loff_t *ppos, io_fn_t fn)
|
|
{
|
|
struct iovec *vector = iov;
|
|
ssize_t ret = 0;
|
|
|
|
while (nr_segs > 0) {
|
|
void __user *base;
|
|
size_t len;
|
|
ssize_t nr;
|
|
|
|
base = vector->iov_base;
|
|
len = vector->iov_len;
|
|
vector++;
|
|
nr_segs--;
|
|
|
|
nr = fn(filp, base, len, ppos);
|
|
|
|
if (nr < 0) {
|
|
if (!ret)
|
|
ret = nr;
|
|
break;
|
|
}
|
|
ret += nr;
|
|
if (nr != len)
|
|
break;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* A write operation does a read from user space and vice versa */
|
|
#define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ)
|
|
|
|
ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
|
|
unsigned long nr_segs, unsigned long fast_segs,
|
|
struct iovec *fast_pointer,
|
|
struct iovec **ret_pointer)
|
|
{
|
|
unsigned long seg;
|
|
ssize_t ret;
|
|
struct iovec *iov = fast_pointer;
|
|
|
|
/*
|
|
* SuS says "The readv() function *may* fail if the iovcnt argument
|
|
* was less than or equal to 0, or greater than {IOV_MAX}. Linux has
|
|
* traditionally returned zero for zero segments, so...
|
|
*/
|
|
if (nr_segs == 0) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* First get the "struct iovec" from user memory and
|
|
* verify all the pointers
|
|
*/
|
|
if (nr_segs > UIO_MAXIOV) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
if (nr_segs > fast_segs) {
|
|
iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL);
|
|
if (iov == NULL) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
}
|
|
if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* According to the Single Unix Specification we should return EINVAL
|
|
* if an element length is < 0 when cast to ssize_t or if the
|
|
* total length would overflow the ssize_t return value of the
|
|
* system call.
|
|
*
|
|
* Linux caps all read/write calls to MAX_RW_COUNT, and avoids the
|
|
* overflow case.
|
|
*/
|
|
ret = 0;
|
|
for (seg = 0; seg < nr_segs; seg++) {
|
|
void __user *buf = iov[seg].iov_base;
|
|
ssize_t len = (ssize_t)iov[seg].iov_len;
|
|
|
|
/* see if we we're about to use an invalid len or if
|
|
* it's about to overflow ssize_t */
|
|
if (len < 0) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
if (unlikely(!access_ok(vrfy_dir(type), buf, len))) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
if (len > MAX_RW_COUNT - ret) {
|
|
len = MAX_RW_COUNT - ret;
|
|
iov[seg].iov_len = len;
|
|
}
|
|
ret += len;
|
|
}
|
|
out:
|
|
*ret_pointer = iov;
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t do_readv_writev(int type, struct file *file,
|
|
const struct iovec __user * uvector,
|
|
unsigned long nr_segs, loff_t *pos)
|
|
{
|
|
size_t tot_len;
|
|
struct iovec iovstack[UIO_FASTIOV];
|
|
struct iovec *iov = iovstack;
|
|
ssize_t ret;
|
|
io_fn_t fn;
|
|
iov_fn_t fnv;
|
|
|
|
if (!file->f_op) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
ret = rw_copy_check_uvector(type, uvector, nr_segs,
|
|
ARRAY_SIZE(iovstack), iovstack, &iov);
|
|
if (ret <= 0)
|
|
goto out;
|
|
|
|
tot_len = ret;
|
|
ret = rw_verify_area(type, file, pos, tot_len);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
fnv = NULL;
|
|
if (type == READ) {
|
|
fn = file->f_op->read;
|
|
fnv = file->f_op->aio_read;
|
|
} else {
|
|
fn = (io_fn_t)file->f_op->write;
|
|
fnv = file->f_op->aio_write;
|
|
}
|
|
|
|
if (fnv)
|
|
ret = do_sync_readv_writev(file, iov, nr_segs, tot_len,
|
|
pos, fnv);
|
|
else
|
|
ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn);
|
|
|
|
out:
|
|
if (iov != iovstack)
|
|
kfree(iov);
|
|
if ((ret + (type == READ)) > 0) {
|
|
if (type == READ)
|
|
fsnotify_access(file);
|
|
else
|
|
fsnotify_modify(file);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
|
|
unsigned long vlen, loff_t *pos)
|
|
{
|
|
if (!(file->f_mode & FMODE_READ))
|
|
return -EBADF;
|
|
if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read))
|
|
return -EINVAL;
|
|
|
|
return do_readv_writev(READ, file, vec, vlen, pos);
|
|
}
|
|
|
|
EXPORT_SYMBOL(vfs_readv);
|
|
|
|
ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
|
|
unsigned long vlen, loff_t *pos)
|
|
{
|
|
if (!(file->f_mode & FMODE_WRITE))
|
|
return -EBADF;
|
|
if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write))
|
|
return -EINVAL;
|
|
|
|
return do_readv_writev(WRITE, file, vec, vlen, pos);
|
|
}
|
|
|
|
EXPORT_SYMBOL(vfs_writev);
|
|
|
|
SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
|
|
unsigned long, vlen)
|
|
{
|
|
struct file *file;
|
|
ssize_t ret = -EBADF;
|
|
int fput_needed;
|
|
|
|
file = fget_light(fd, &fput_needed);
|
|
if (file) {
|
|
loff_t pos = file_pos_read(file);
|
|
ret = vfs_readv(file, vec, vlen, &pos);
|
|
file_pos_write(file, pos);
|
|
fput_light(file, fput_needed);
|
|
}
|
|
|
|
if (ret > 0)
|
|
add_rchar(current, ret);
|
|
inc_syscr(current);
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
|
|
unsigned long, vlen)
|
|
{
|
|
struct file *file;
|
|
ssize_t ret = -EBADF;
|
|
int fput_needed;
|
|
|
|
file = fget_light(fd, &fput_needed);
|
|
if (file) {
|
|
loff_t pos = file_pos_read(file);
|
|
ret = vfs_writev(file, vec, vlen, &pos);
|
|
file_pos_write(file, pos);
|
|
fput_light(file, fput_needed);
|
|
}
|
|
|
|
if (ret > 0)
|
|
add_wchar(current, ret);
|
|
inc_syscw(current);
|
|
return ret;
|
|
}
|
|
|
|
static inline loff_t pos_from_hilo(unsigned long high, unsigned long low)
|
|
{
|
|
#define HALF_LONG_BITS (BITS_PER_LONG / 2)
|
|
return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low;
|
|
}
|
|
|
|
SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
|
|
unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
|
|
{
|
|
loff_t pos = pos_from_hilo(pos_h, pos_l);
|
|
struct file *file;
|
|
ssize_t ret = -EBADF;
|
|
int fput_needed;
|
|
|
|
if (pos < 0)
|
|
return -EINVAL;
|
|
|
|
file = fget_light(fd, &fput_needed);
|
|
if (file) {
|
|
ret = -ESPIPE;
|
|
if (file->f_mode & FMODE_PREAD)
|
|
ret = vfs_readv(file, vec, vlen, &pos);
|
|
fput_light(file, fput_needed);
|
|
}
|
|
|
|
if (ret > 0)
|
|
add_rchar(current, ret);
|
|
inc_syscr(current);
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
|
|
unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
|
|
{
|
|
loff_t pos = pos_from_hilo(pos_h, pos_l);
|
|
struct file *file;
|
|
ssize_t ret = -EBADF;
|
|
int fput_needed;
|
|
|
|
if (pos < 0)
|
|
return -EINVAL;
|
|
|
|
file = fget_light(fd, &fput_needed);
|
|
if (file) {
|
|
ret = -ESPIPE;
|
|
if (file->f_mode & FMODE_PWRITE)
|
|
ret = vfs_writev(file, vec, vlen, &pos);
|
|
fput_light(file, fput_needed);
|
|
}
|
|
|
|
if (ret > 0)
|
|
add_wchar(current, ret);
|
|
inc_syscw(current);
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
|
|
size_t count, loff_t max)
|
|
{
|
|
struct file * in_file, * out_file;
|
|
struct inode * in_inode, * out_inode;
|
|
loff_t pos;
|
|
ssize_t retval;
|
|
int fput_needed_in, fput_needed_out, fl;
|
|
|
|
/*
|
|
* Get input file, and verify that it is ok..
|
|
*/
|
|
retval = -EBADF;
|
|
in_file = fget_light(in_fd, &fput_needed_in);
|
|
if (!in_file)
|
|
goto out;
|
|
if (!(in_file->f_mode & FMODE_READ))
|
|
goto fput_in;
|
|
retval = -ESPIPE;
|
|
if (!ppos)
|
|
ppos = &in_file->f_pos;
|
|
else
|
|
if (!(in_file->f_mode & FMODE_PREAD))
|
|
goto fput_in;
|
|
retval = rw_verify_area(READ, in_file, ppos, count);
|
|
if (retval < 0)
|
|
goto fput_in;
|
|
count = retval;
|
|
|
|
/*
|
|
* Get output file, and verify that it is ok..
|
|
*/
|
|
retval = -EBADF;
|
|
out_file = fget_light(out_fd, &fput_needed_out);
|
|
if (!out_file)
|
|
goto fput_in;
|
|
if (!(out_file->f_mode & FMODE_WRITE))
|
|
goto fput_out;
|
|
retval = -EINVAL;
|
|
in_inode = in_file->f_path.dentry->d_inode;
|
|
out_inode = out_file->f_path.dentry->d_inode;
|
|
retval = rw_verify_area(WRITE, out_file, &out_file->f_pos, count);
|
|
if (retval < 0)
|
|
goto fput_out;
|
|
count = retval;
|
|
|
|
if (!max)
|
|
max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
|
|
|
|
pos = *ppos;
|
|
if (unlikely(pos + count > max)) {
|
|
retval = -EOVERFLOW;
|
|
if (pos >= max)
|
|
goto fput_out;
|
|
count = max - pos;
|
|
}
|
|
|
|
fl = 0;
|
|
#if 0
|
|
/*
|
|
* We need to debate whether we can enable this or not. The
|
|
* man page documents EAGAIN return for the output at least,
|
|
* and the application is arguably buggy if it doesn't expect
|
|
* EAGAIN on a non-blocking file descriptor.
|
|
*/
|
|
if (in_file->f_flags & O_NONBLOCK)
|
|
fl = SPLICE_F_NONBLOCK;
|
|
#endif
|
|
retval = do_splice_direct(in_file, ppos, out_file, count, fl);
|
|
|
|
if (retval > 0) {
|
|
add_rchar(current, retval);
|
|
add_wchar(current, retval);
|
|
}
|
|
|
|
inc_syscr(current);
|
|
inc_syscw(current);
|
|
if (*ppos > max)
|
|
retval = -EOVERFLOW;
|
|
|
|
fput_out:
|
|
fput_light(out_file, fput_needed_out);
|
|
fput_in:
|
|
fput_light(in_file, fput_needed_in);
|
|
out:
|
|
return retval;
|
|
}
|
|
|
|
SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
|
|
{
|
|
loff_t pos;
|
|
off_t off;
|
|
ssize_t ret;
|
|
|
|
if (offset) {
|
|
if (unlikely(get_user(off, offset)))
|
|
return -EFAULT;
|
|
pos = off;
|
|
ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
|
|
if (unlikely(put_user(pos, offset)))
|
|
return -EFAULT;
|
|
return ret;
|
|
}
|
|
|
|
return do_sendfile(out_fd, in_fd, NULL, count, 0);
|
|
}
|
|
|
|
SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
|
|
{
|
|
loff_t pos;
|
|
ssize_t ret;
|
|
|
|
if (offset) {
|
|
if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
|
|
return -EFAULT;
|
|
ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
|
|
if (unlikely(put_user(pos, offset)))
|
|
return -EFAULT;
|
|
return ret;
|
|
}
|
|
|
|
return do_sendfile(out_fd, in_fd, NULL, count, 0);
|
|
}
|