mirror of https://gitee.com/openkylin/linux.git
1835 lines
42 KiB
C
1835 lines
42 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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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/sched/xacct.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/export.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 <linux/compat.h>
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#include <linux/mount.h>
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#include <linux/fs.h>
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#include "internal.h"
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#include <linux/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_iter = generic_file_read_iter,
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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 bool 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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* vfs_setpos - update the file offset for lseek
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* @file: file structure in question
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* @offset: file offset to seek to
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* @maxsize: maximum file size
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*
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* This is a low-level filesystem helper for updating the file offset to
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* the value specified by @offset if the given offset is valid and it is
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* not equal to the current file offset.
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*
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* Return the specified offset on success and -EINVAL on invalid offset.
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*/
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loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize)
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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 > maxsize)
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return -EINVAL;
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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(vfs_setpos);
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/**
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* generic_file_llseek_size - 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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* @whence: type of seek
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* @size: max size of this file in file system
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* @eof: offset used for SEEK_END position
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*
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* This is a variant of generic_file_llseek that allows passing in a custom
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* maximum file size and a custom EOF position, for e.g. hashed directories
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*
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* Synchronization:
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* SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms)
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* SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes.
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* read/writes behave like SEEK_SET against seeks.
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*/
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loff_t
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generic_file_llseek_size(struct file *file, loff_t offset, int whence,
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loff_t maxsize, loff_t eof)
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{
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switch (whence) {
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case SEEK_END:
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offset += eof;
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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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/*
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* f_lock protects against read/modify/write race with other
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* SEEK_CURs. Note that parallel writes and reads behave
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* like SEEK_SET.
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*/
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spin_lock(&file->f_lock);
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offset = vfs_setpos(file, file->f_pos + offset, maxsize);
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spin_unlock(&file->f_lock);
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return offset;
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case SEEK_DATA:
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/*
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* In the generic case the entire file is data, so as long as
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* offset isn't at the end of the file then the offset is data.
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*/
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if ((unsigned long long)offset >= eof)
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return -ENXIO;
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break;
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case SEEK_HOLE:
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/*
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* There is a virtual hole at the end of the file, so as long as
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* offset isn't i_size or larger, return i_size.
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*/
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if ((unsigned long long)offset >= eof)
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return -ENXIO;
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offset = eof;
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break;
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}
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return vfs_setpos(file, offset, maxsize);
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}
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EXPORT_SYMBOL(generic_file_llseek_size);
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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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* @whence: 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 @whence.
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*/
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loff_t generic_file_llseek(struct file *file, loff_t offset, int whence)
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{
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struct inode *inode = file->f_mapping->host;
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return generic_file_llseek_size(file, offset, whence,
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inode->i_sb->s_maxbytes,
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i_size_read(inode));
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}
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EXPORT_SYMBOL(generic_file_llseek);
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/**
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* fixed_size_llseek - llseek implementation for fixed-sized devices
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* @file: file structure to seek on
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* @offset: file offset to seek to
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* @whence: type of seek
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* @size: size of the file
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*
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*/
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loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size)
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{
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switch (whence) {
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case SEEK_SET: case SEEK_CUR: case SEEK_END:
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return generic_file_llseek_size(file, offset, whence,
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size, size);
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default:
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return -EINVAL;
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}
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}
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EXPORT_SYMBOL(fixed_size_llseek);
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/**
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* no_seek_end_llseek - llseek implementation for fixed-sized devices
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* @file: file structure to seek on
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* @offset: file offset to seek to
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* @whence: type of seek
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*
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*/
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loff_t no_seek_end_llseek(struct file *file, loff_t offset, int whence)
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{
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switch (whence) {
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case SEEK_SET: case SEEK_CUR:
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return generic_file_llseek_size(file, offset, whence,
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OFFSET_MAX, 0);
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default:
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return -EINVAL;
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}
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}
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EXPORT_SYMBOL(no_seek_end_llseek);
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/**
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* no_seek_end_llseek_size - llseek implementation for fixed-sized devices
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* @file: file structure to seek on
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* @offset: file offset to seek to
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* @whence: type of seek
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* @size: maximal offset allowed
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*
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*/
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loff_t no_seek_end_llseek_size(struct file *file, loff_t offset, int whence, loff_t size)
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{
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switch (whence) {
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case SEEK_SET: case SEEK_CUR:
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return generic_file_llseek_size(file, offset, whence,
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size, 0);
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default:
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return -EINVAL;
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}
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}
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EXPORT_SYMBOL(no_seek_end_llseek_size);
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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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* @whence: 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 whence)
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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 whence)
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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 whence)
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{
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struct inode *inode = file_inode(file);
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loff_t retval;
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inode_lock(inode);
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switch (whence) {
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case SEEK_END:
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offset += i_size_read(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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break;
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case SEEK_DATA:
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/*
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* In the generic case the entire file is data, so as
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* long as offset isn't at the end of the file then the
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* offset is data.
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*/
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if (offset >= inode->i_size) {
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retval = -ENXIO;
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goto out;
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}
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break;
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case SEEK_HOLE:
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/*
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* There is a virtual hole at the end of the file, so
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* as long as offset isn't i_size or larger, return
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* i_size.
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*/
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if (offset >= inode->i_size) {
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retval = -ENXIO;
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goto out;
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}
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offset = inode->i_size;
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break;
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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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inode_unlock(inode);
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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 whence)
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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->llseek)
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fn = file->f_op->llseek;
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}
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return fn(file, offset, whence);
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}
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EXPORT_SYMBOL(vfs_llseek);
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static off_t ksys_lseek(unsigned int fd, off_t offset, unsigned int whence)
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{
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off_t retval;
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struct fd f = fdget_pos(fd);
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if (!f.file)
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return -EBADF;
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retval = -EINVAL;
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if (whence <= SEEK_MAX) {
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loff_t res = vfs_llseek(f.file, offset, whence);
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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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fdput_pos(f);
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return retval;
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}
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SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence)
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{
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return ksys_lseek(fd, offset, whence);
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}
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#ifdef CONFIG_COMPAT
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COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence)
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{
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return ksys_lseek(fd, offset, whence);
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}
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#endif
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#if !defined(CONFIG_64BIT) || defined(CONFIG_COMPAT) || \
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defined(__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, whence)
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{
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int retval;
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struct fd f = fdget_pos(fd);
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loff_t offset;
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if (!f.file)
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return -EBADF;
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retval = -EINVAL;
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if (whence > SEEK_MAX)
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goto out_putf;
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offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low,
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whence);
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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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fdput_pos(f);
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return retval;
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}
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#endif
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int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count)
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{
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struct inode *inode;
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int retval = -EINVAL;
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inode = file_inode(file);
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if (unlikely((ssize_t) count < 0))
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return retval;
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/*
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* ranged mandatory locking does not apply to streams - it makes sense
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* only for files where position has a meaning.
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*/
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if (ppos) {
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loff_t 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_flctx && mandatory_lock(inode))) {
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retval = locks_mandatory_area(inode, file, pos, pos + count - 1,
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read_write == READ ? F_RDLCK : F_WRLCK);
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if (retval < 0)
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return retval;
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}
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}
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return security_file_permission(file,
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read_write == READ ? MAY_READ : MAY_WRITE);
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}
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static ssize_t new_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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struct iov_iter iter;
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ssize_t ret;
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init_sync_kiocb(&kiocb, filp);
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kiocb.ki_pos = (ppos ? *ppos : 0);
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iov_iter_init(&iter, READ, &iov, 1, len);
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ret = call_read_iter(filp, &kiocb, &iter);
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BUG_ON(ret == -EIOCBQUEUED);
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if (ppos)
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*ppos = kiocb.ki_pos;
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return ret;
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}
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ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
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{
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mm_segment_t old_fs = get_fs();
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ssize_t ret;
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if (WARN_ON_ONCE(!(file->f_mode & FMODE_READ)))
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return -EINVAL;
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if (!(file->f_mode & FMODE_CAN_READ))
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return -EINVAL;
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if (count > MAX_RW_COUNT)
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count = MAX_RW_COUNT;
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set_fs(KERNEL_DS);
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if (file->f_op->read)
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ret = file->f_op->read(file, (void __user *)buf, count, pos);
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else if (file->f_op->read_iter)
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ret = new_sync_read(file, (void __user *)buf, count, pos);
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else
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ret = -EINVAL;
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set_fs(old_fs);
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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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return ret;
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}
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ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
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{
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ssize_t ret;
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ret = rw_verify_area(READ, file, pos, count);
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if (ret)
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return ret;
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return __kernel_read(file, buf, count, pos);
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}
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EXPORT_SYMBOL(kernel_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_mode & FMODE_CAN_READ))
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return -EINVAL;
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if (unlikely(!access_ok(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)
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return ret;
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if (count > MAX_RW_COUNT)
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count = MAX_RW_COUNT;
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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 if (file->f_op->read_iter)
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ret = new_sync_read(file, buf, count, pos);
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else
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ret = -EINVAL;
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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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return ret;
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}
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static ssize_t new_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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struct iov_iter iter;
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ssize_t ret;
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init_sync_kiocb(&kiocb, filp);
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kiocb.ki_pos = (ppos ? *ppos : 0);
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iov_iter_init(&iter, WRITE, &iov, 1, len);
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ret = call_write_iter(filp, &kiocb, &iter);
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BUG_ON(ret == -EIOCBQUEUED);
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if (ret > 0 && ppos)
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*ppos = kiocb.ki_pos;
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return ret;
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}
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|
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/* caller is responsible for file_start_write/file_end_write */
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ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos)
|
|
{
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mm_segment_t old_fs;
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const char __user *p;
|
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ssize_t ret;
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|
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if (WARN_ON_ONCE(!(file->f_mode & FMODE_WRITE)))
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return -EBADF;
|
|
if (!(file->f_mode & FMODE_CAN_WRITE))
|
|
return -EINVAL;
|
|
|
|
old_fs = get_fs();
|
|
set_fs(KERNEL_DS);
|
|
p = (__force const char __user *)buf;
|
|
if (count > MAX_RW_COUNT)
|
|
count = MAX_RW_COUNT;
|
|
if (file->f_op->write)
|
|
ret = file->f_op->write(file, p, count, pos);
|
|
else if (file->f_op->write_iter)
|
|
ret = new_sync_write(file, p, count, pos);
|
|
else
|
|
ret = -EINVAL;
|
|
set_fs(old_fs);
|
|
if (ret > 0) {
|
|
fsnotify_modify(file);
|
|
add_wchar(current, ret);
|
|
}
|
|
inc_syscw(current);
|
|
return ret;
|
|
}
|
|
/*
|
|
* This "EXPORT_SYMBOL_GPL()" is more of a "EXPORT_SYMBOL_DONTUSE()",
|
|
* but autofs is one of the few internal kernel users that actually
|
|
* wants this _and_ can be built as a module. So we need to export
|
|
* this symbol for autofs, even though it really isn't appropriate
|
|
* for any other kernel modules.
|
|
*/
|
|
EXPORT_SYMBOL_GPL(__kernel_write);
|
|
|
|
ssize_t kernel_write(struct file *file, const void *buf, size_t count,
|
|
loff_t *pos)
|
|
{
|
|
ssize_t ret;
|
|
|
|
ret = rw_verify_area(WRITE, file, pos, count);
|
|
if (ret)
|
|
return ret;
|
|
|
|
file_start_write(file);
|
|
ret = __kernel_write(file, buf, count, pos);
|
|
file_end_write(file);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kernel_write);
|
|
|
|
ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
|
|
{
|
|
ssize_t ret;
|
|
|
|
if (!(file->f_mode & FMODE_WRITE))
|
|
return -EBADF;
|
|
if (!(file->f_mode & FMODE_CAN_WRITE))
|
|
return -EINVAL;
|
|
if (unlikely(!access_ok(buf, count)))
|
|
return -EFAULT;
|
|
|
|
ret = rw_verify_area(WRITE, file, pos, count);
|
|
if (ret)
|
|
return ret;
|
|
if (count > MAX_RW_COUNT)
|
|
count = MAX_RW_COUNT;
|
|
file_start_write(file);
|
|
if (file->f_op->write)
|
|
ret = file->f_op->write(file, buf, count, pos);
|
|
else if (file->f_op->write_iter)
|
|
ret = new_sync_write(file, buf, count, pos);
|
|
else
|
|
ret = -EINVAL;
|
|
if (ret > 0) {
|
|
fsnotify_modify(file);
|
|
add_wchar(current, ret);
|
|
}
|
|
inc_syscw(current);
|
|
file_end_write(file);
|
|
return ret;
|
|
}
|
|
|
|
/* file_ppos returns &file->f_pos or NULL if file is stream */
|
|
static inline loff_t *file_ppos(struct file *file)
|
|
{
|
|
return file->f_mode & FMODE_STREAM ? NULL : &file->f_pos;
|
|
}
|
|
|
|
ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count)
|
|
{
|
|
struct fd f = fdget_pos(fd);
|
|
ssize_t ret = -EBADF;
|
|
|
|
if (f.file) {
|
|
loff_t pos, *ppos = file_ppos(f.file);
|
|
if (ppos) {
|
|
pos = *ppos;
|
|
ppos = &pos;
|
|
}
|
|
ret = vfs_read(f.file, buf, count, ppos);
|
|
if (ret >= 0 && ppos)
|
|
f.file->f_pos = pos;
|
|
fdput_pos(f);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
|
|
{
|
|
return ksys_read(fd, buf, count);
|
|
}
|
|
|
|
ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count)
|
|
{
|
|
struct fd f = fdget_pos(fd);
|
|
ssize_t ret = -EBADF;
|
|
|
|
if (f.file) {
|
|
loff_t pos, *ppos = file_ppos(f.file);
|
|
if (ppos) {
|
|
pos = *ppos;
|
|
ppos = &pos;
|
|
}
|
|
ret = vfs_write(f.file, buf, count, ppos);
|
|
if (ret >= 0 && ppos)
|
|
f.file->f_pos = pos;
|
|
fdput_pos(f);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
|
|
size_t, count)
|
|
{
|
|
return ksys_write(fd, buf, count);
|
|
}
|
|
|
|
ssize_t ksys_pread64(unsigned int fd, char __user *buf, size_t count,
|
|
loff_t pos)
|
|
{
|
|
struct fd f;
|
|
ssize_t ret = -EBADF;
|
|
|
|
if (pos < 0)
|
|
return -EINVAL;
|
|
|
|
f = fdget(fd);
|
|
if (f.file) {
|
|
ret = -ESPIPE;
|
|
if (f.file->f_mode & FMODE_PREAD)
|
|
ret = vfs_read(f.file, buf, count, &pos);
|
|
fdput(f);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf,
|
|
size_t, count, loff_t, pos)
|
|
{
|
|
return ksys_pread64(fd, buf, count, pos);
|
|
}
|
|
|
|
ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf,
|
|
size_t count, loff_t pos)
|
|
{
|
|
struct fd f;
|
|
ssize_t ret = -EBADF;
|
|
|
|
if (pos < 0)
|
|
return -EINVAL;
|
|
|
|
f = fdget(fd);
|
|
if (f.file) {
|
|
ret = -ESPIPE;
|
|
if (f.file->f_mode & FMODE_PWRITE)
|
|
ret = vfs_write(f.file, buf, count, &pos);
|
|
fdput(f);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf,
|
|
size_t, count, loff_t, pos)
|
|
{
|
|
return ksys_pwrite64(fd, buf, count, pos);
|
|
}
|
|
|
|
static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
|
|
loff_t *ppos, int type, rwf_t flags)
|
|
{
|
|
struct kiocb kiocb;
|
|
ssize_t ret;
|
|
|
|
init_sync_kiocb(&kiocb, filp);
|
|
ret = kiocb_set_rw_flags(&kiocb, flags);
|
|
if (ret)
|
|
return ret;
|
|
kiocb.ki_pos = (ppos ? *ppos : 0);
|
|
|
|
if (type == READ)
|
|
ret = call_read_iter(filp, &kiocb, iter);
|
|
else
|
|
ret = call_write_iter(filp, &kiocb, iter);
|
|
BUG_ON(ret == -EIOCBQUEUED);
|
|
if (ppos)
|
|
*ppos = kiocb.ki_pos;
|
|
return ret;
|
|
}
|
|
|
|
/* Do it by hand, with file-ops */
|
|
static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter,
|
|
loff_t *ppos, int type, rwf_t flags)
|
|
{
|
|
ssize_t ret = 0;
|
|
|
|
if (flags & ~RWF_HIPRI)
|
|
return -EOPNOTSUPP;
|
|
|
|
while (iov_iter_count(iter)) {
|
|
struct iovec iovec = iov_iter_iovec(iter);
|
|
ssize_t nr;
|
|
|
|
if (type == READ) {
|
|
nr = filp->f_op->read(filp, iovec.iov_base,
|
|
iovec.iov_len, ppos);
|
|
} else {
|
|
nr = filp->f_op->write(filp, iovec.iov_base,
|
|
iovec.iov_len, ppos);
|
|
}
|
|
|
|
if (nr < 0) {
|
|
if (!ret)
|
|
ret = nr;
|
|
break;
|
|
}
|
|
ret += nr;
|
|
if (nr != iovec.iov_len)
|
|
break;
|
|
iov_iter_advance(iter, nr);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* rw_copy_check_uvector() - Copy an array of &struct iovec from userspace
|
|
* into the kernel and check that it is valid.
|
|
*
|
|
* @type: One of %CHECK_IOVEC_ONLY, %READ, or %WRITE.
|
|
* @uvector: Pointer to the userspace array.
|
|
* @nr_segs: Number of elements in userspace array.
|
|
* @fast_segs: Number of elements in @fast_pointer.
|
|
* @fast_pointer: Pointer to (usually small on-stack) kernel array.
|
|
* @ret_pointer: (output parameter) Pointer to a variable that will point to
|
|
* either @fast_pointer, a newly allocated kernel array, or NULL,
|
|
* depending on which array was used.
|
|
*
|
|
* This function copies an array of &struct iovec of @nr_segs from
|
|
* userspace into the kernel and checks that each element is valid (e.g.
|
|
* it does not point to a kernel address or cause overflow by being too
|
|
* large, etc.).
|
|
*
|
|
* As an optimization, the caller may provide a pointer to a small
|
|
* on-stack array in @fast_pointer, typically %UIO_FASTIOV elements long
|
|
* (the size of this array, or 0 if unused, should be given in @fast_segs).
|
|
*
|
|
* @ret_pointer will always point to the array that was used, so the
|
|
* caller must take care not to call kfree() on it e.g. in case the
|
|
* @fast_pointer array was used and it was allocated on the stack.
|
|
*
|
|
* Return: The total number of bytes covered by the iovec array on success
|
|
* or a negative error code on error.
|
|
*/
|
|
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_array(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 (type >= 0
|
|
&& unlikely(!access_ok(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;
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
ssize_t compat_rw_copy_check_uvector(int type,
|
|
const struct compat_iovec __user *uvector, unsigned long nr_segs,
|
|
unsigned long fast_segs, struct iovec *fast_pointer,
|
|
struct iovec **ret_pointer)
|
|
{
|
|
compat_ssize_t tot_len;
|
|
struct iovec *iov = *ret_pointer = fast_pointer;
|
|
ssize_t ret = 0;
|
|
int seg;
|
|
|
|
/*
|
|
* 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)
|
|
goto out;
|
|
|
|
ret = -EINVAL;
|
|
if (nr_segs > UIO_MAXIOV)
|
|
goto out;
|
|
if (nr_segs > fast_segs) {
|
|
ret = -ENOMEM;
|
|
iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL);
|
|
if (iov == NULL)
|
|
goto out;
|
|
}
|
|
*ret_pointer = iov;
|
|
|
|
ret = -EFAULT;
|
|
if (!access_ok(uvector, nr_segs*sizeof(*uvector)))
|
|
goto out;
|
|
|
|
/*
|
|
* Single unix specification:
|
|
* We should -EINVAL if an element length is not >= 0 and fitting an
|
|
* ssize_t.
|
|
*
|
|
* In Linux, the total length is limited to MAX_RW_COUNT, there is
|
|
* no overflow possibility.
|
|
*/
|
|
tot_len = 0;
|
|
ret = -EINVAL;
|
|
for (seg = 0; seg < nr_segs; seg++) {
|
|
compat_uptr_t buf;
|
|
compat_ssize_t len;
|
|
|
|
if (__get_user(len, &uvector->iov_len) ||
|
|
__get_user(buf, &uvector->iov_base)) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
if (len < 0) /* size_t not fitting in compat_ssize_t .. */
|
|
goto out;
|
|
if (type >= 0 &&
|
|
!access_ok(compat_ptr(buf), len)) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
if (len > MAX_RW_COUNT - tot_len)
|
|
len = MAX_RW_COUNT - tot_len;
|
|
tot_len += len;
|
|
iov->iov_base = compat_ptr(buf);
|
|
iov->iov_len = (compat_size_t) len;
|
|
uvector++;
|
|
iov++;
|
|
}
|
|
ret = tot_len;
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
#endif
|
|
|
|
static ssize_t do_iter_read(struct file *file, struct iov_iter *iter,
|
|
loff_t *pos, rwf_t flags)
|
|
{
|
|
size_t tot_len;
|
|
ssize_t ret = 0;
|
|
|
|
if (!(file->f_mode & FMODE_READ))
|
|
return -EBADF;
|
|
if (!(file->f_mode & FMODE_CAN_READ))
|
|
return -EINVAL;
|
|
|
|
tot_len = iov_iter_count(iter);
|
|
if (!tot_len)
|
|
goto out;
|
|
ret = rw_verify_area(READ, file, pos, tot_len);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (file->f_op->read_iter)
|
|
ret = do_iter_readv_writev(file, iter, pos, READ, flags);
|
|
else
|
|
ret = do_loop_readv_writev(file, iter, pos, READ, flags);
|
|
out:
|
|
if (ret >= 0)
|
|
fsnotify_access(file);
|
|
return ret;
|
|
}
|
|
|
|
ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb,
|
|
struct iov_iter *iter)
|
|
{
|
|
size_t tot_len;
|
|
ssize_t ret = 0;
|
|
|
|
if (!file->f_op->read_iter)
|
|
return -EINVAL;
|
|
if (!(file->f_mode & FMODE_READ))
|
|
return -EBADF;
|
|
if (!(file->f_mode & FMODE_CAN_READ))
|
|
return -EINVAL;
|
|
|
|
tot_len = iov_iter_count(iter);
|
|
if (!tot_len)
|
|
goto out;
|
|
ret = rw_verify_area(READ, file, &iocb->ki_pos, tot_len);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = call_read_iter(file, iocb, iter);
|
|
out:
|
|
if (ret >= 0)
|
|
fsnotify_access(file);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(vfs_iocb_iter_read);
|
|
|
|
ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos,
|
|
rwf_t flags)
|
|
{
|
|
if (!file->f_op->read_iter)
|
|
return -EINVAL;
|
|
return do_iter_read(file, iter, ppos, flags);
|
|
}
|
|
EXPORT_SYMBOL(vfs_iter_read);
|
|
|
|
static ssize_t do_iter_write(struct file *file, struct iov_iter *iter,
|
|
loff_t *pos, rwf_t flags)
|
|
{
|
|
size_t tot_len;
|
|
ssize_t ret = 0;
|
|
|
|
if (!(file->f_mode & FMODE_WRITE))
|
|
return -EBADF;
|
|
if (!(file->f_mode & FMODE_CAN_WRITE))
|
|
return -EINVAL;
|
|
|
|
tot_len = iov_iter_count(iter);
|
|
if (!tot_len)
|
|
return 0;
|
|
ret = rw_verify_area(WRITE, file, pos, tot_len);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (file->f_op->write_iter)
|
|
ret = do_iter_readv_writev(file, iter, pos, WRITE, flags);
|
|
else
|
|
ret = do_loop_readv_writev(file, iter, pos, WRITE, flags);
|
|
if (ret > 0)
|
|
fsnotify_modify(file);
|
|
return ret;
|
|
}
|
|
|
|
ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb,
|
|
struct iov_iter *iter)
|
|
{
|
|
size_t tot_len;
|
|
ssize_t ret = 0;
|
|
|
|
if (!file->f_op->write_iter)
|
|
return -EINVAL;
|
|
if (!(file->f_mode & FMODE_WRITE))
|
|
return -EBADF;
|
|
if (!(file->f_mode & FMODE_CAN_WRITE))
|
|
return -EINVAL;
|
|
|
|
tot_len = iov_iter_count(iter);
|
|
if (!tot_len)
|
|
return 0;
|
|
ret = rw_verify_area(WRITE, file, &iocb->ki_pos, tot_len);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = call_write_iter(file, iocb, iter);
|
|
if (ret > 0)
|
|
fsnotify_modify(file);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(vfs_iocb_iter_write);
|
|
|
|
ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,
|
|
rwf_t flags)
|
|
{
|
|
if (!file->f_op->write_iter)
|
|
return -EINVAL;
|
|
return do_iter_write(file, iter, ppos, flags);
|
|
}
|
|
EXPORT_SYMBOL(vfs_iter_write);
|
|
|
|
ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
|
|
unsigned long vlen, loff_t *pos, rwf_t flags)
|
|
{
|
|
struct iovec iovstack[UIO_FASTIOV];
|
|
struct iovec *iov = iovstack;
|
|
struct iov_iter iter;
|
|
ssize_t ret;
|
|
|
|
ret = import_iovec(READ, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter);
|
|
if (ret >= 0) {
|
|
ret = do_iter_read(file, &iter, pos, flags);
|
|
kfree(iov);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
|
|
unsigned long vlen, loff_t *pos, rwf_t flags)
|
|
{
|
|
struct iovec iovstack[UIO_FASTIOV];
|
|
struct iovec *iov = iovstack;
|
|
struct iov_iter iter;
|
|
ssize_t ret;
|
|
|
|
ret = import_iovec(WRITE, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter);
|
|
if (ret >= 0) {
|
|
file_start_write(file);
|
|
ret = do_iter_write(file, &iter, pos, flags);
|
|
file_end_write(file);
|
|
kfree(iov);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec,
|
|
unsigned long vlen, rwf_t flags)
|
|
{
|
|
struct fd f = fdget_pos(fd);
|
|
ssize_t ret = -EBADF;
|
|
|
|
if (f.file) {
|
|
loff_t pos, *ppos = file_ppos(f.file);
|
|
if (ppos) {
|
|
pos = *ppos;
|
|
ppos = &pos;
|
|
}
|
|
ret = vfs_readv(f.file, vec, vlen, ppos, flags);
|
|
if (ret >= 0 && ppos)
|
|
f.file->f_pos = pos;
|
|
fdput_pos(f);
|
|
}
|
|
|
|
if (ret > 0)
|
|
add_rchar(current, ret);
|
|
inc_syscr(current);
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t do_writev(unsigned long fd, const struct iovec __user *vec,
|
|
unsigned long vlen, rwf_t flags)
|
|
{
|
|
struct fd f = fdget_pos(fd);
|
|
ssize_t ret = -EBADF;
|
|
|
|
if (f.file) {
|
|
loff_t pos, *ppos = file_ppos(f.file);
|
|
if (ppos) {
|
|
pos = *ppos;
|
|
ppos = &pos;
|
|
}
|
|
ret = vfs_writev(f.file, vec, vlen, ppos, flags);
|
|
if (ret >= 0 && ppos)
|
|
f.file->f_pos = pos;
|
|
fdput_pos(f);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec,
|
|
unsigned long vlen, loff_t pos, rwf_t flags)
|
|
{
|
|
struct fd f;
|
|
ssize_t ret = -EBADF;
|
|
|
|
if (pos < 0)
|
|
return -EINVAL;
|
|
|
|
f = fdget(fd);
|
|
if (f.file) {
|
|
ret = -ESPIPE;
|
|
if (f.file->f_mode & FMODE_PREAD)
|
|
ret = vfs_readv(f.file, vec, vlen, &pos, flags);
|
|
fdput(f);
|
|
}
|
|
|
|
if (ret > 0)
|
|
add_rchar(current, ret);
|
|
inc_syscr(current);
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t do_pwritev(unsigned long fd, const struct iovec __user *vec,
|
|
unsigned long vlen, loff_t pos, rwf_t flags)
|
|
{
|
|
struct fd f;
|
|
ssize_t ret = -EBADF;
|
|
|
|
if (pos < 0)
|
|
return -EINVAL;
|
|
|
|
f = fdget(fd);
|
|
if (f.file) {
|
|
ret = -ESPIPE;
|
|
if (f.file->f_mode & FMODE_PWRITE)
|
|
ret = vfs_writev(f.file, vec, vlen, &pos, flags);
|
|
fdput(f);
|
|
}
|
|
|
|
if (ret > 0)
|
|
add_wchar(current, ret);
|
|
inc_syscw(current);
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
|
|
unsigned long, vlen)
|
|
{
|
|
return do_readv(fd, vec, vlen, 0);
|
|
}
|
|
|
|
SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
|
|
unsigned long, vlen)
|
|
{
|
|
return do_writev(fd, vec, vlen, 0);
|
|
}
|
|
|
|
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);
|
|
|
|
return do_preadv(fd, vec, vlen, pos, 0);
|
|
}
|
|
|
|
SYSCALL_DEFINE6(preadv2, unsigned long, fd, const struct iovec __user *, vec,
|
|
unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
|
|
rwf_t, flags)
|
|
{
|
|
loff_t pos = pos_from_hilo(pos_h, pos_l);
|
|
|
|
if (pos == -1)
|
|
return do_readv(fd, vec, vlen, flags);
|
|
|
|
return do_preadv(fd, vec, vlen, pos, flags);
|
|
}
|
|
|
|
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);
|
|
|
|
return do_pwritev(fd, vec, vlen, pos, 0);
|
|
}
|
|
|
|
SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec,
|
|
unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
|
|
rwf_t, flags)
|
|
{
|
|
loff_t pos = pos_from_hilo(pos_h, pos_l);
|
|
|
|
if (pos == -1)
|
|
return do_writev(fd, vec, vlen, flags);
|
|
|
|
return do_pwritev(fd, vec, vlen, pos, flags);
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static size_t compat_readv(struct file *file,
|
|
const struct compat_iovec __user *vec,
|
|
unsigned long vlen, loff_t *pos, rwf_t flags)
|
|
{
|
|
struct iovec iovstack[UIO_FASTIOV];
|
|
struct iovec *iov = iovstack;
|
|
struct iov_iter iter;
|
|
ssize_t ret;
|
|
|
|
ret = compat_import_iovec(READ, vec, vlen, UIO_FASTIOV, &iov, &iter);
|
|
if (ret >= 0) {
|
|
ret = do_iter_read(file, &iter, pos, flags);
|
|
kfree(iov);
|
|
}
|
|
if (ret > 0)
|
|
add_rchar(current, ret);
|
|
inc_syscr(current);
|
|
return ret;
|
|
}
|
|
|
|
static size_t do_compat_readv(compat_ulong_t fd,
|
|
const struct compat_iovec __user *vec,
|
|
compat_ulong_t vlen, rwf_t flags)
|
|
{
|
|
struct fd f = fdget_pos(fd);
|
|
ssize_t ret;
|
|
loff_t pos;
|
|
|
|
if (!f.file)
|
|
return -EBADF;
|
|
pos = f.file->f_pos;
|
|
ret = compat_readv(f.file, vec, vlen, &pos, flags);
|
|
if (ret >= 0)
|
|
f.file->f_pos = pos;
|
|
fdput_pos(f);
|
|
return ret;
|
|
|
|
}
|
|
|
|
COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
|
|
const struct compat_iovec __user *,vec,
|
|
compat_ulong_t, vlen)
|
|
{
|
|
return do_compat_readv(fd, vec, vlen, 0);
|
|
}
|
|
|
|
static long do_compat_preadv64(unsigned long fd,
|
|
const struct compat_iovec __user *vec,
|
|
unsigned long vlen, loff_t pos, rwf_t flags)
|
|
{
|
|
struct fd f;
|
|
ssize_t ret;
|
|
|
|
if (pos < 0)
|
|
return -EINVAL;
|
|
f = fdget(fd);
|
|
if (!f.file)
|
|
return -EBADF;
|
|
ret = -ESPIPE;
|
|
if (f.file->f_mode & FMODE_PREAD)
|
|
ret = compat_readv(f.file, vec, vlen, &pos, flags);
|
|
fdput(f);
|
|
return ret;
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
|
|
COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
|
|
const struct compat_iovec __user *,vec,
|
|
unsigned long, vlen, loff_t, pos)
|
|
{
|
|
return do_compat_preadv64(fd, vec, vlen, pos, 0);
|
|
}
|
|
#endif
|
|
|
|
COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
|
|
const struct compat_iovec __user *,vec,
|
|
compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
|
|
{
|
|
loff_t pos = ((loff_t)pos_high << 32) | pos_low;
|
|
|
|
return do_compat_preadv64(fd, vec, vlen, pos, 0);
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2
|
|
COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd,
|
|
const struct compat_iovec __user *,vec,
|
|
unsigned long, vlen, loff_t, pos, rwf_t, flags)
|
|
{
|
|
if (pos == -1)
|
|
return do_compat_readv(fd, vec, vlen, flags);
|
|
|
|
return do_compat_preadv64(fd, vec, vlen, pos, flags);
|
|
}
|
|
#endif
|
|
|
|
COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd,
|
|
const struct compat_iovec __user *,vec,
|
|
compat_ulong_t, vlen, u32, pos_low, u32, pos_high,
|
|
rwf_t, flags)
|
|
{
|
|
loff_t pos = ((loff_t)pos_high << 32) | pos_low;
|
|
|
|
if (pos == -1)
|
|
return do_compat_readv(fd, vec, vlen, flags);
|
|
|
|
return do_compat_preadv64(fd, vec, vlen, pos, flags);
|
|
}
|
|
|
|
static size_t compat_writev(struct file *file,
|
|
const struct compat_iovec __user *vec,
|
|
unsigned long vlen, loff_t *pos, rwf_t flags)
|
|
{
|
|
struct iovec iovstack[UIO_FASTIOV];
|
|
struct iovec *iov = iovstack;
|
|
struct iov_iter iter;
|
|
ssize_t ret;
|
|
|
|
ret = compat_import_iovec(WRITE, vec, vlen, UIO_FASTIOV, &iov, &iter);
|
|
if (ret >= 0) {
|
|
file_start_write(file);
|
|
ret = do_iter_write(file, &iter, pos, flags);
|
|
file_end_write(file);
|
|
kfree(iov);
|
|
}
|
|
if (ret > 0)
|
|
add_wchar(current, ret);
|
|
inc_syscw(current);
|
|
return ret;
|
|
}
|
|
|
|
static size_t do_compat_writev(compat_ulong_t fd,
|
|
const struct compat_iovec __user* vec,
|
|
compat_ulong_t vlen, rwf_t flags)
|
|
{
|
|
struct fd f = fdget_pos(fd);
|
|
ssize_t ret;
|
|
loff_t pos;
|
|
|
|
if (!f.file)
|
|
return -EBADF;
|
|
pos = f.file->f_pos;
|
|
ret = compat_writev(f.file, vec, vlen, &pos, flags);
|
|
if (ret >= 0)
|
|
f.file->f_pos = pos;
|
|
fdput_pos(f);
|
|
return ret;
|
|
}
|
|
|
|
COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
|
|
const struct compat_iovec __user *, vec,
|
|
compat_ulong_t, vlen)
|
|
{
|
|
return do_compat_writev(fd, vec, vlen, 0);
|
|
}
|
|
|
|
static long do_compat_pwritev64(unsigned long fd,
|
|
const struct compat_iovec __user *vec,
|
|
unsigned long vlen, loff_t pos, rwf_t flags)
|
|
{
|
|
struct fd f;
|
|
ssize_t ret;
|
|
|
|
if (pos < 0)
|
|
return -EINVAL;
|
|
f = fdget(fd);
|
|
if (!f.file)
|
|
return -EBADF;
|
|
ret = -ESPIPE;
|
|
if (f.file->f_mode & FMODE_PWRITE)
|
|
ret = compat_writev(f.file, vec, vlen, &pos, flags);
|
|
fdput(f);
|
|
return ret;
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
|
|
COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
|
|
const struct compat_iovec __user *,vec,
|
|
unsigned long, vlen, loff_t, pos)
|
|
{
|
|
return do_compat_pwritev64(fd, vec, vlen, pos, 0);
|
|
}
|
|
#endif
|
|
|
|
COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
|
|
const struct compat_iovec __user *,vec,
|
|
compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
|
|
{
|
|
loff_t pos = ((loff_t)pos_high << 32) | pos_low;
|
|
|
|
return do_compat_pwritev64(fd, vec, vlen, pos, 0);
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2
|
|
COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd,
|
|
const struct compat_iovec __user *,vec,
|
|
unsigned long, vlen, loff_t, pos, rwf_t, flags)
|
|
{
|
|
if (pos == -1)
|
|
return do_compat_writev(fd, vec, vlen, flags);
|
|
|
|
return do_compat_pwritev64(fd, vec, vlen, pos, flags);
|
|
}
|
|
#endif
|
|
|
|
COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd,
|
|
const struct compat_iovec __user *,vec,
|
|
compat_ulong_t, vlen, u32, pos_low, u32, pos_high, rwf_t, flags)
|
|
{
|
|
loff_t pos = ((loff_t)pos_high << 32) | pos_low;
|
|
|
|
if (pos == -1)
|
|
return do_compat_writev(fd, vec, vlen, flags);
|
|
|
|
return do_compat_pwritev64(fd, vec, vlen, pos, flags);
|
|
}
|
|
|
|
#endif
|
|
|
|
static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
|
|
size_t count, loff_t max)
|
|
{
|
|
struct fd in, out;
|
|
struct inode *in_inode, *out_inode;
|
|
loff_t pos;
|
|
loff_t out_pos;
|
|
ssize_t retval;
|
|
int fl;
|
|
|
|
/*
|
|
* Get input file, and verify that it is ok..
|
|
*/
|
|
retval = -EBADF;
|
|
in = fdget(in_fd);
|
|
if (!in.file)
|
|
goto out;
|
|
if (!(in.file->f_mode & FMODE_READ))
|
|
goto fput_in;
|
|
retval = -ESPIPE;
|
|
if (!ppos) {
|
|
pos = in.file->f_pos;
|
|
} else {
|
|
pos = *ppos;
|
|
if (!(in.file->f_mode & FMODE_PREAD))
|
|
goto fput_in;
|
|
}
|
|
retval = rw_verify_area(READ, in.file, &pos, count);
|
|
if (retval < 0)
|
|
goto fput_in;
|
|
if (count > MAX_RW_COUNT)
|
|
count = MAX_RW_COUNT;
|
|
|
|
/*
|
|
* Get output file, and verify that it is ok..
|
|
*/
|
|
retval = -EBADF;
|
|
out = fdget(out_fd);
|
|
if (!out.file)
|
|
goto fput_in;
|
|
if (!(out.file->f_mode & FMODE_WRITE))
|
|
goto fput_out;
|
|
in_inode = file_inode(in.file);
|
|
out_inode = file_inode(out.file);
|
|
out_pos = out.file->f_pos;
|
|
retval = rw_verify_area(WRITE, out.file, &out_pos, count);
|
|
if (retval < 0)
|
|
goto fput_out;
|
|
|
|
if (!max)
|
|
max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
|
|
|
|
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
|
|
file_start_write(out.file);
|
|
retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
|
|
file_end_write(out.file);
|
|
|
|
if (retval > 0) {
|
|
add_rchar(current, retval);
|
|
add_wchar(current, retval);
|
|
fsnotify_access(in.file);
|
|
fsnotify_modify(out.file);
|
|
out.file->f_pos = out_pos;
|
|
if (ppos)
|
|
*ppos = pos;
|
|
else
|
|
in.file->f_pos = pos;
|
|
}
|
|
|
|
inc_syscr(current);
|
|
inc_syscw(current);
|
|
if (pos > max)
|
|
retval = -EOVERFLOW;
|
|
|
|
fput_out:
|
|
fdput(out);
|
|
fput_in:
|
|
fdput(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);
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd,
|
|
compat_off_t __user *, offset, compat_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);
|
|
}
|
|
|
|
COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
|
|
compat_loff_t __user *, offset, compat_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);
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* generic_copy_file_range - copy data between two files
|
|
* @file_in: file structure to read from
|
|
* @pos_in: file offset to read from
|
|
* @file_out: file structure to write data to
|
|
* @pos_out: file offset to write data to
|
|
* @len: amount of data to copy
|
|
* @flags: copy flags
|
|
*
|
|
* This is a generic filesystem helper to copy data from one file to another.
|
|
* It has no constraints on the source or destination file owners - the files
|
|
* can belong to different superblocks and different filesystem types. Short
|
|
* copies are allowed.
|
|
*
|
|
* This should be called from the @file_out filesystem, as per the
|
|
* ->copy_file_range() method.
|
|
*
|
|
* Returns the number of bytes copied or a negative error indicating the
|
|
* failure.
|
|
*/
|
|
|
|
ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in,
|
|
struct file *file_out, loff_t pos_out,
|
|
size_t len, unsigned int flags)
|
|
{
|
|
return do_splice_direct(file_in, &pos_in, file_out, &pos_out,
|
|
len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
|
|
}
|
|
EXPORT_SYMBOL(generic_copy_file_range);
|
|
|
|
static ssize_t do_copy_file_range(struct file *file_in, loff_t pos_in,
|
|
struct file *file_out, loff_t pos_out,
|
|
size_t len, unsigned int flags)
|
|
{
|
|
/*
|
|
* Although we now allow filesystems to handle cross sb copy, passing
|
|
* a file of the wrong filesystem type to filesystem driver can result
|
|
* in an attempt to dereference the wrong type of ->private_data, so
|
|
* avoid doing that until we really have a good reason. NFS defines
|
|
* several different file_system_type structures, but they all end up
|
|
* using the same ->copy_file_range() function pointer.
|
|
*/
|
|
if (file_out->f_op->copy_file_range &&
|
|
file_out->f_op->copy_file_range == file_in->f_op->copy_file_range)
|
|
return file_out->f_op->copy_file_range(file_in, pos_in,
|
|
file_out, pos_out,
|
|
len, flags);
|
|
|
|
return generic_copy_file_range(file_in, pos_in, file_out, pos_out, len,
|
|
flags);
|
|
}
|
|
|
|
/*
|
|
* copy_file_range() differs from regular file read and write in that it
|
|
* specifically allows return partial success. When it does so is up to
|
|
* the copy_file_range method.
|
|
*/
|
|
ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
|
|
struct file *file_out, loff_t pos_out,
|
|
size_t len, unsigned int flags)
|
|
{
|
|
ssize_t ret;
|
|
|
|
if (flags != 0)
|
|
return -EINVAL;
|
|
|
|
ret = generic_copy_file_checks(file_in, pos_in, file_out, pos_out, &len,
|
|
flags);
|
|
if (unlikely(ret))
|
|
return ret;
|
|
|
|
ret = rw_verify_area(READ, file_in, &pos_in, len);
|
|
if (unlikely(ret))
|
|
return ret;
|
|
|
|
ret = rw_verify_area(WRITE, file_out, &pos_out, len);
|
|
if (unlikely(ret))
|
|
return ret;
|
|
|
|
if (len == 0)
|
|
return 0;
|
|
|
|
file_start_write(file_out);
|
|
|
|
/*
|
|
* Try cloning first, this is supported by more file systems, and
|
|
* more efficient if both clone and copy are supported (e.g. NFS).
|
|
*/
|
|
if (file_in->f_op->remap_file_range &&
|
|
file_inode(file_in)->i_sb == file_inode(file_out)->i_sb) {
|
|
loff_t cloned;
|
|
|
|
cloned = file_in->f_op->remap_file_range(file_in, pos_in,
|
|
file_out, pos_out,
|
|
min_t(loff_t, MAX_RW_COUNT, len),
|
|
REMAP_FILE_CAN_SHORTEN);
|
|
if (cloned > 0) {
|
|
ret = cloned;
|
|
goto done;
|
|
}
|
|
}
|
|
|
|
ret = do_copy_file_range(file_in, pos_in, file_out, pos_out, len,
|
|
flags);
|
|
WARN_ON_ONCE(ret == -EOPNOTSUPP);
|
|
done:
|
|
if (ret > 0) {
|
|
fsnotify_access(file_in);
|
|
add_rchar(current, ret);
|
|
fsnotify_modify(file_out);
|
|
add_wchar(current, ret);
|
|
}
|
|
|
|
inc_syscr(current);
|
|
inc_syscw(current);
|
|
|
|
file_end_write(file_out);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(vfs_copy_file_range);
|
|
|
|
SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in,
|
|
int, fd_out, loff_t __user *, off_out,
|
|
size_t, len, unsigned int, flags)
|
|
{
|
|
loff_t pos_in;
|
|
loff_t pos_out;
|
|
struct fd f_in;
|
|
struct fd f_out;
|
|
ssize_t ret = -EBADF;
|
|
|
|
f_in = fdget(fd_in);
|
|
if (!f_in.file)
|
|
goto out2;
|
|
|
|
f_out = fdget(fd_out);
|
|
if (!f_out.file)
|
|
goto out1;
|
|
|
|
ret = -EFAULT;
|
|
if (off_in) {
|
|
if (copy_from_user(&pos_in, off_in, sizeof(loff_t)))
|
|
goto out;
|
|
} else {
|
|
pos_in = f_in.file->f_pos;
|
|
}
|
|
|
|
if (off_out) {
|
|
if (copy_from_user(&pos_out, off_out, sizeof(loff_t)))
|
|
goto out;
|
|
} else {
|
|
pos_out = f_out.file->f_pos;
|
|
}
|
|
|
|
ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len,
|
|
flags);
|
|
if (ret > 0) {
|
|
pos_in += ret;
|
|
pos_out += ret;
|
|
|
|
if (off_in) {
|
|
if (copy_to_user(off_in, &pos_in, sizeof(loff_t)))
|
|
ret = -EFAULT;
|
|
} else {
|
|
f_in.file->f_pos = pos_in;
|
|
}
|
|
|
|
if (off_out) {
|
|
if (copy_to_user(off_out, &pos_out, sizeof(loff_t)))
|
|
ret = -EFAULT;
|
|
} else {
|
|
f_out.file->f_pos = pos_out;
|
|
}
|
|
}
|
|
|
|
out:
|
|
fdput(f_out);
|
|
out1:
|
|
fdput(f_in);
|
|
out2:
|
|
return ret;
|
|
}
|