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https://github.com/FEX-Emu/linux.git
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ac34ebb3a6
A cleanup of rw_copy_check_uvector and compat_rw_copy_check_uvector after changes made to support CMA in an earlier patch. Rather than having an additional check_access parameter to these functions, the first paramater type is overloaded to allow the caller to specify CHECK_IOVEC_ONLY which means check that the contents of the iovec are valid, but do not check the memory that they point to. This is used by process_vm_readv/writev where we need to validate that a iovec passed to the syscall is valid but do not want to check the memory that it points to at this point because it refers to an address space in another process. Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1008 lines
22 KiB
C
1008 lines
22 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/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 "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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static loff_t lseek_execute(struct file *file, struct inode *inode,
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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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/**
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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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* @origin: type of seek
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* @size: max size of file system
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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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* file size.
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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 origin,
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loff_t maxsize)
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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 += i_size_read(inode);
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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 = lseek_execute(file, inode, file->f_pos + offset,
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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 (offset >= i_size_read(inode))
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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 (offset >= i_size_read(inode))
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return -ENXIO;
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offset = i_size_read(inode);
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break;
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}
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return lseek_execute(file, inode, 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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* @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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struct inode *inode = file->f_mapping->host;
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return generic_file_llseek_size(file, offset, origin,
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inode->i_sb->s_maxbytes);
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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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struct inode *inode = file->f_path.dentry->d_inode;
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loff_t retval;
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mutex_lock(&inode->i_mutex);
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switch (origin) {
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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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mutex_unlock(&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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if (pos < 0)
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return -EINVAL;
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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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}
|
|
|
|
return ret;
|
|
}
|
|
#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
|
|
asmlinkage long SyS_pread64(long fd, long buf, long count, loff_t pos)
|
|
{
|
|
return SYSC_pread64((unsigned int) fd, (char __user *) buf,
|
|
(size_t) count, pos);
|
|
}
|
|
SYSCALL_ALIAS(sys_pread64, SyS_pread64);
|
|
#endif
|
|
|
|
SYSCALL_DEFINE(pwrite64)(unsigned int fd, const char __user *buf,
|
|
size_t count, loff_t pos)
|
|
{
|
|
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_write(file, buf, count, &pos);
|
|
fput_light(file, fput_needed);
|
|
}
|
|
|
|
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,
|
|
(size_t) count, pos);
|
|
}
|
|
SYSCALL_ALIAS(sys_pwrite64, SyS_pwrite64);
|
|
#endif
|
|
|
|
/*
|
|
* 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 (type >= 0
|
|
&& 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);
|
|
}
|