Commit message: vfs: hoist the btrfs deduplication ioctl to the vfs

Hoist the btrfs EXTENT_SAME ioctl up to the VFS and make the name
more systematic (FIDEDUPERANGE).

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
CVE: CVE-2016-6516
Vulnerability description: Race condition in the ioctl_file_dedupe_range function in fs/ioctl.c in the Linux kernel through 4.7 allows local users to cause a denial of service (heap-based buffer overflow) or possibly gain privileges by changing a certain count value, aka a "double fetch" vulnerability.

Project: linux
File: ioctl.c

int generic_block_fiemap(struct inode *inode,
			 struct fiemap_extent_info *fieinfo, u64 start,
			 u64 len, get_block_t *get_block)
{
	int ret;
	mutex_lock(&inode->i_mutex);
	ret = __generic_block_fiemap(inode, fieinfo, start, len, get_block);
	mutex_unlock(&inode->i_mutex);
	return ret;
}

Project: linux
File: read_write.c

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 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);
		fdput(f);
	}

	if (ret > 0)
		add_rchar(current, ret);
	inc_syscr(current);
	return ret;
}

Project: linux
File: read_write.c

static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
		loff_t *ppos, iter_fn_t fn)
{
	struct kiocb kiocb;
	ssize_t ret;

	init_sync_kiocb(&kiocb, filp);
	kiocb.ki_pos = *ppos;

	ret = fn(&kiocb, iter);
	BUG_ON(ret == -EIOCBQUEUED);
	*ppos = kiocb.ki_pos;
	return ret;
}

Project: linux
File: read_write.c

COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence)
{
	return sys_lseek(fd, offset, whence);
}

Project: linux
File: read_write.c

SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high,
		unsigned long, offset_low, loff_t __user *, result,
		unsigned int, whence)
{
	int retval;
	struct fd f = fdget_pos(fd);
	loff_t offset;

	if (!f.file)
		return -EBADF;

	retval = -EINVAL;
	if (whence > SEEK_MAX)
		goto out_putf;

	offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low,
			whence);

	retval = (int)offset;
	if (offset >= 0) {
		retval = -EFAULT;
		if (!copy_to_user(result, &offset, sizeof(offset)))
			retval = 0;
	}
out_putf:
	fdput_pos(f);
	return retval;
}

Project: linux
File: read_write.c

static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
{
	struct iovec iov = { .iov_base = buf, .iov_len = len };
	struct kiocb kiocb;
	struct iov_iter iter;
	ssize_t ret;

	init_sync_kiocb(&kiocb, filp);
	kiocb.ki_pos = *ppos;
	iov_iter_init(&iter, READ, &iov, 1, len);

	ret = filp->f_op->read_iter(&kiocb, &iter);
	BUG_ON(ret == -EIOCBQUEUED);
	*ppos = kiocb.ki_pos;
	return ret;
}

Project: linux
File: read_write.c

int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
{
	struct file_dedupe_range_info *info;
	struct inode *src = file_inode(file);
	u64 off;
	u64 len;
	int i;
	int ret;
	bool is_admin = capable(CAP_SYS_ADMIN);
	u16 count = same->dest_count;
	struct file *dst_file;
	loff_t dst_off;
	ssize_t deduped;

	if (!(file->f_mode & FMODE_READ))
		return -EINVAL;

	if (same->reserved1 || same->reserved2)
		return -EINVAL;

	off = same->src_offset;
	len = same->src_length;

	ret = -EISDIR;
	if (S_ISDIR(src->i_mode))
		goto out;

	ret = -EINVAL;
	if (!S_ISREG(src->i_mode))
		goto out;

	ret = clone_verify_area(file, off, len, false);
	if (ret < 0)
		goto out;
	ret = 0;

	/* pre-format output fields to sane values */
	for (i = 0; i < count; i++) {
		same->info[i].bytes_deduped = 0ULL;
		same->info[i].status = FILE_DEDUPE_RANGE_SAME;
	}

	for (i = 0, info = same->info; i < count; i++, info++) {
		struct inode *dst;
		struct fd dst_fd = fdget(info->dest_fd);

		dst_file = dst_fd.file;
		if (!dst_file) {
			info->status = -EBADF;
			goto next_loop;
		}
		dst = file_inode(dst_file);

		ret = mnt_want_write_file(dst_file);
		if (ret) {
			info->status = ret;
			goto next_loop;
		}

		dst_off = info->dest_offset;
		ret = clone_verify_area(dst_file, dst_off, len, true);
		if (ret < 0) {
			info->status = ret;
			goto next_file;
		}
		ret = 0;

		if (info->reserved) {
			info->status = -EINVAL;
		} else if (!(is_admin || (dst_file->f_mode & FMODE_WRITE))) {
			info->status = -EINVAL;
		} else if (file->f_path.mnt != dst_file->f_path.mnt) {
			info->status = -EXDEV;
		} else if (S_ISDIR(dst->i_mode)) {
			info->status = -EISDIR;
		} else if (dst_file->f_op->dedupe_file_range == NULL) {
			info->status = -EINVAL;
		} else {
			deduped = dst_file->f_op->dedupe_file_range(file, off,
							len, dst_file,
							info->dest_offset);
			if (deduped == -EBADE)
				info->status = FILE_DEDUPE_RANGE_DIFFERS;
			else if (deduped < 0)
				info->status = deduped;
			else
				info->bytes_deduped += deduped;
		}

next_file:
		mnt_drop_write_file(dst_file);
next_loop:
		fdput(dst_fd);
	}

out:
	return ret;
}

Project: linux
File: read_write.c

static ssize_t compat_do_readv_writev(int type, struct file *file,
			       const struct compat_iovec __user *uvector,
			       unsigned long nr_segs, loff_t *pos)
{
	compat_ssize_t tot_len;
	struct iovec iovstack[UIO_FASTIOV];
	struct iovec *iov = iovstack;
	struct iov_iter iter;
	ssize_t ret;
	io_fn_t fn;
	iter_fn_t iter_fn;

	ret = compat_import_iovec(type, uvector, nr_segs,
				  UIO_FASTIOV, &iov, &iter);
	if (ret < 0)
		return ret;

	tot_len = iov_iter_count(&iter);
	if (!tot_len)
		goto out;
	ret = rw_verify_area(type, file, pos, tot_len);
	if (ret < 0)
		goto out;

	if (type == READ) {
		fn = file->f_op->read;
		iter_fn = file->f_op->read_iter;
	} else {
		fn = (io_fn_t)file->f_op->write;
		iter_fn = file->f_op->write_iter;
		file_start_write(file);
	}

	if (iter_fn)
		ret = do_iter_readv_writev(file, &iter, pos, iter_fn);
	else
		ret = do_loop_readv_writev(file, &iter, pos, fn);

	if (type != READ)
		file_end_write(file);

out:
	kfree(iov);
	if ((ret + (type == READ)) > 0) {
		if (type == READ)
			fsnotify_access(file);
		else
			fsnotify_modify(file);
	}
	return ret;
}

Project: linux
File: read_write.c

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(VERIFY_READ, buf, count)))
		return -EFAULT;

	ret = rw_verify_area(WRITE, file, pos, count);
	if (ret >= 0) {
		count = ret;
		file_start_write(file);
		ret = __vfs_write(file, buf, count, pos);
		if (ret > 0) {
			fsnotify_modify(file);
			add_wchar(current, ret);
		}
		inc_syscw(current);
		file_end_write(file);
	}

	return ret;
}

Project: linux
File: read_write.c

SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence)
{
	off_t retval;
	struct fd f = fdget_pos(fd);
	if (!f.file)
		return -EBADF;

	retval = -EINVAL;
	if (whence <= SEEK_MAX) {
		loff_t res = vfs_llseek(f.file, offset, whence);
		retval = res;
		if (res != (loff_t)retval)
			retval = -EOVERFLOW;	/* LFS: should only happen on 32 bit platforms */
	}
	fdput_pos(f);
	return retval;
}

Project: linux
File: ioctl.c

int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
	     unsigned long arg)
{
	int error = 0;
	int __user *argp = (int __user *)arg;
	struct inode *inode = file_inode(filp);

	switch (cmd) {
	case FIOCLEX:
		set_close_on_exec(fd, 1);
		break;

	case FIONCLEX:
		set_close_on_exec(fd, 0);
		break;

	case FIONBIO:
		error = ioctl_fionbio(filp, argp);
		break;

	case FIOASYNC:
		error = ioctl_fioasync(fd, filp, argp);
		break;

	case FIOQSIZE:
		if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode) ||
		    S_ISLNK(inode->i_mode)) {
			loff_t res = inode_get_bytes(inode);
			error = copy_to_user(argp, &res, sizeof(res)) ?
					-EFAULT : 0;
		} else
			error = -ENOTTY;
		break;

	case FIFREEZE:
		error = ioctl_fsfreeze(filp);
		break;

	case FITHAW:
		error = ioctl_fsthaw(filp);
		break;

	case FS_IOC_FIEMAP:
		return ioctl_fiemap(filp, arg);

	case FIGETBSZ:
		return put_user(inode->i_sb->s_blocksize, argp);

	case FICLONE:
		return ioctl_file_clone(filp, arg, 0, 0, 0);

	case FICLONERANGE:
		return ioctl_file_clone_range(filp, argp);

	case FIDEDUPERANGE:
		return ioctl_file_dedupe_range(filp, argp);

	default:
		if (S_ISREG(inode->i_mode))
			error = file_ioctl(filp, cmd, arg);
		else
			error = vfs_ioctl(filp, cmd, arg);
		break;
	}
	return error;
}

Project: linux
File: compat_ioctl.c

static int do_i2c_rdwr_ioctl(unsigned int fd, unsigned int cmd,
			struct i2c_rdwr_ioctl_data32    __user *udata)
{
	struct i2c_rdwr_aligned		__user *tdata;
	struct i2c_msg			__user *tmsgs;
	struct i2c_msg32		__user *umsgs;
	compat_caddr_t			datap;
	u32				nmsgs;
	int				i;

	if (get_user(nmsgs, &udata->nmsgs))
		return -EFAULT;
	if (nmsgs > I2C_RDWR_IOCTL_MAX_MSGS)
		return -EINVAL;

	if (get_user(datap, &udata->msgs))
		return -EFAULT;
	umsgs = compat_ptr(datap);

	tdata = compat_alloc_user_space(sizeof(*tdata) +
				      nmsgs * sizeof(struct i2c_msg));
	tmsgs = &tdata->msgs[0];

	if (put_user(nmsgs, &tdata->cmd.nmsgs) ||
	    put_user(tmsgs, &tdata->cmd.msgs))
		return -EFAULT;

	for (i = 0; i < nmsgs; i++) {
		if (copy_in_user(&tmsgs[i].addr, &umsgs[i].addr, 3*sizeof(u16)))
			return -EFAULT;
		if (get_user(datap, &umsgs[i].buf) ||
		    put_user(compat_ptr(datap), &tmsgs[i].buf))
			return -EFAULT;
	}
	return sys_ioctl(fd, cmd, (unsigned long)tdata);
}

Project: linux
File: read_write.c

static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
{
	struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
	struct kiocb kiocb;
	struct iov_iter iter;
	ssize_t ret;

	init_sync_kiocb(&kiocb, filp);
	kiocb.ki_pos = *ppos;
	iov_iter_init(&iter, WRITE, &iov, 1, len);

	ret = filp->f_op->write_iter(&kiocb, &iter);
	BUG_ON(ret == -EIOCBQUEUED);
	if (ret > 0)
		*ppos = kiocb.ki_pos;
	return ret;
}

Project: linux
File: read_write.c

loff_t generic_file_llseek(struct file *file, loff_t offset, int whence)
{
	struct inode *inode = file->f_mapping->host;

	return generic_file_llseek_size(file, offset, whence,
					inode->i_sb->s_maxbytes,
					i_size_read(inode));
}

Project: linux
File: read_write.c

static long __compat_sys_pwritev64(unsigned long fd,
				   const struct compat_iovec __user *vec,
				   unsigned long vlen, loff_t pos)
{
	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);
	fdput(f);
	return ret;
}

Project: linux
File: read_write.c

ssize_t __vfs_read(struct file *file, char __user *buf, size_t count,
		   loff_t *pos)
{
	if (file->f_op->read)
		return file->f_op->read(file, buf, count, pos);
	else if (file->f_op->read_iter)
		return new_sync_read(file, buf, count, pos);
	else
		return -EINVAL;
}

Project: linux
File: read_write.c

loff_t vfs_llseek(struct file *file, loff_t offset, int whence)
{
	loff_t (*fn)(struct file *, loff_t, int);

	fn = no_llseek;
	if (file->f_mode & FMODE_LSEEK) {
		if (file->f_op->llseek)
			fn = file->f_op->llseek;
	}
	return fn(file, offset, whence);
}

Project: linux
File: read_write.c

int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count)
{
	struct inode *inode;
	loff_t pos;
	int retval = -EINVAL;

	inode = file_inode(file);
	if (unlikely((ssize_t) count < 0))
		return retval;
	pos = *ppos;
	if (unlikely(pos < 0)) {
		if (!unsigned_offsets(file))
			return retval;
		if (count >= -pos) /* both values are in 0..LLONG_MAX */
			return -EOVERFLOW;
	} else if (unlikely((loff_t) (pos + count) < 0)) {
		if (!unsigned_offsets(file))
			return retval;
	}

	if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
		retval = locks_mandatory_area(inode, file, pos, pos + count - 1,
				read_write == READ ? F_RDLCK : F_WRLCK);
		if (retval < 0)
			return retval;
	}
	retval = security_file_permission(file,
				read_write == READ ? MAY_READ : MAY_WRITE);
	if (retval)
		return retval;
	return count > MAX_RW_COUNT ? MAX_RW_COUNT : count;
}

Project: linux
File: read_write.c

static long __compat_sys_preadv64(unsigned long fd,
				  const struct compat_iovec __user *vec,
				  unsigned long vlen, loff_t pos)
{
	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);
	fdput(f);
	return ret;
}

Project: linux
File: read_write.c

ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos)
{
	mm_segment_t old_fs;
	const char __user *p;
	ssize_t ret;

	if (!(file->f_mode & FMODE_CAN_WRITE))
		return -EINVAL;

	old_fs = get_fs();
	set_fs(get_ds());
	p = (__force const char __user *)buf;
	if (count > MAX_RW_COUNT)
		count =  MAX_RW_COUNT;
	ret = __vfs_write(file, p, count, pos);
	set_fs(old_fs);
	if (ret > 0) {
		fsnotify_modify(file);
		add_wchar(current, ret);
	}
	inc_syscw(current);
	return ret;
}

Project: linux
File: read_write.c

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);
}

Project: linux
File: read_write.c

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)
{
	struct inode *inode_in = file_inode(file_in);
	struct inode *inode_out = file_inode(file_out);
	ssize_t ret;

	if (flags != 0)
		return -EINVAL;

	/* copy_file_range allows full ssize_t len, ignoring MAX_RW_COUNT  */
	ret = rw_verify_area(READ, file_in, &pos_in, len);
	if (ret >= 0)
		ret = rw_verify_area(WRITE, file_out, &pos_out, len);
	if (ret < 0)
		return ret;

	if (!(file_in->f_mode & FMODE_READ) ||
	    !(file_out->f_mode & FMODE_WRITE) ||
	    (file_out->f_flags & O_APPEND))
		return -EBADF;

	/* this could be relaxed once a method supports cross-fs copies */
	if (inode_in->i_sb != inode_out->i_sb)
		return -EXDEV;

	if (len == 0)
		return 0;

	ret = mnt_want_write_file(file_out);
	if (ret)
		return ret;

	ret = -EOPNOTSUPP;
	if (file_out->f_op->copy_file_range)
		ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out,
						      pos_out, len, flags);
	if (ret == -EOPNOTSUPP)
		ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out,
				len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);

	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);

	mnt_drop_write_file(file_out);

	return ret;
}

Project: linux
File: read_write.c

static size_t compat_writev(struct file *file,
			    const struct compat_iovec __user *vec,
			    unsigned long vlen, loff_t *pos)
{
	ssize_t ret = -EBADF;

	if (!(file->f_mode & FMODE_WRITE))
		goto out;

	ret = -EINVAL;
	if (!(file->f_mode & FMODE_CAN_WRITE))
		goto out;

	ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos);

out:
	if (ret > 0)
		add_wchar(current, ret);
	inc_syscw(current);
	return ret;
}

Project: linux
File: read_write.c

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 __compat_sys_pwritev64(fd, vec, vlen, pos);
}

Project: linux
File: compat_ioctl.c

COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd,
		       compat_ulong_t, arg32)
{
	unsigned long arg = arg32;
	struct fd f = fdget(fd);
	int error = -EBADF;
	if (!f.file)
		goto out;

	/* RED-PEN how should LSM module know it's handling 32bit? */
	error = security_file_ioctl(f.file, cmd, arg);
	if (error)
		goto out_fput;

	/*
	 * To allow the compat_ioctl handlers to be self contained
	 * we need to check the common ioctls here first.
	 * Just handle them with the standard handlers below.
	 */
	switch (cmd) {
	case FIOCLEX:
	case FIONCLEX:
	case FIONBIO:
	case FIOASYNC:
	case FIOQSIZE:
		break;

#if defined(CONFIG_IA64) || defined(CONFIG_X86_64)
	case FS_IOC_RESVSP_32:
	case FS_IOC_RESVSP64_32:
		error = compat_ioctl_preallocate(f.file, compat_ptr(arg));
		goto out_fput;
#else
	case FS_IOC_RESVSP:
	case FS_IOC_RESVSP64:
		error = ioctl_preallocate(f.file, compat_ptr(arg));
		goto out_fput;
#endif

	case FICLONE:
	case FICLONERANGE:
	case FIDEDUPERANGE:
		goto do_ioctl;

	case FIBMAP:
	case FIGETBSZ:
	case FIONREAD:
		if (S_ISREG(file_inode(f.file)->i_mode))
			break;
		/*FALL THROUGH*/

	default:
		if (f.file->f_op->compat_ioctl) {
			error = f.file->f_op->compat_ioctl(f.file, cmd, arg);
			if (error != -ENOIOCTLCMD)
				goto out_fput;
		}

		if (!f.file->f_op->unlocked_ioctl)
			goto do_ioctl;
		break;
	}

	if (compat_ioctl_check_table(XFORM(cmd)))
		goto found_handler;

	error = do_ioctl_trans(fd, cmd, arg, f.file);
	if (error == -ENOIOCTLCMD)
		error = -ENOTTY;

	goto out_fput;

 found_handler:
	arg = (unsigned long)compat_ptr(arg);
 do_ioctl:
	error = do_vfs_ioctl(f.file, fd, cmd, arg);
 out_fput:
	fdput(f);
 out:
	return error;
}

Project: linux
File: read_write.c

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_mode & FMODE_CAN_WRITE))
		return -EINVAL;

	return do_readv_writev(WRITE, file, vec, vlen, pos);
}

Project: linux
File: ioctl.c

static long vfs_ioctl(struct file *filp, unsigned int cmd,
		      unsigned long arg)
{
	int error = -ENOTTY;

	if (!filp->f_op->unlocked_ioctl)
		goto out;

	error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
	if (error == -ENOIOCTLCMD)
		error = -ENOTTY;
 out:
	return error;
}

Project: linux
File: read_write.c

SYSCALL_DEFINE3(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 = file_pos_read(f.file);
		ret = vfs_read(f.file, buf, count, &pos);
		if (ret >= 0)
			file_pos_write(f.file, pos);
		fdput_pos(f);
	}
	return ret;
}

Project: linux
File: read_write.c

ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
{
	ssize_t ret;

	if (!(file->f_mode & FMODE_READ))
		return -EBADF;
	if (!(file->f_mode & FMODE_CAN_READ))
		return -EINVAL;
	if (unlikely(!access_ok(VERIFY_WRITE, buf, count)))
		return -EFAULT;

	ret = rw_verify_area(READ, file, pos, count);
	if (ret >= 0) {
		count = ret;
		ret = __vfs_read(file, buf, count, pos);
		if (ret > 0) {
			fsnotify_access(file);
			add_rchar(current, ret);
		}
		inc_syscr(current);
	}

	return ret;
}

Project: linux
File: read_write.c

COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
		const struct compat_iovec __user *, vec,
		compat_ulong_t, vlen)
{
	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);
	if (ret >= 0)
		f.file->f_pos = pos;
	fdput_pos(f);
	return ret;
}

Project: linux
File: read_write.c

loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size)
{
	switch (whence) {
	case SEEK_SET: case SEEK_CUR: case SEEK_END:
		return generic_file_llseek_size(file, offset, whence,
						size, size);
	default:
		return -EINVAL;
	}
}

Project: linux
File: read_write.c

SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
		unsigned long, vlen)
{
	struct fd f = fdget_pos(fd);
	ssize_t ret = -EBADF;

	if (f.file) {
		loff_t pos = file_pos_read(f.file);
		ret = vfs_writev(f.file, vec, vlen, &pos);
		if (ret >= 0)
			file_pos_write(f.file, pos);
		fdput_pos(f);
	}

	if (ret > 0)
		add_wchar(current, ret);
	inc_syscw(current);
	return ret;
}

Project: linux
File: read_write.c

loff_t default_llseek(struct file *file, loff_t offset, int whence)
{
	struct inode *inode = file_inode(file);
	loff_t retval;

	mutex_lock(&inode->i_mutex);
	switch (whence) {
		case SEEK_END:
			offset += i_size_read(inode);
			break;
		case SEEK_CUR:
			if (offset == 0) {
				retval = file->f_pos;
				goto out;
			}
			offset += file->f_pos;
			break;
		case SEEK_DATA:
			/*
			 * In the generic case the entire file is data, so as
			 * long as offset isn't at the end of the file then the
			 * offset is data.
			 */
			if (offset >= inode->i_size) {
				retval = -ENXIO;
				goto out;
			}
			break;
		case SEEK_HOLE:
			/*
			 * There is a virtual hole at the end of the file, so
			 * as long as offset isn't i_size or larger, return
			 * i_size.
			 */
			if (offset >= inode->i_size) {
				retval = -ENXIO;
				goto out;
			}
			offset = inode->i_size;
			break;
	}
	retval = -EINVAL;
	if (offset >= 0 || unsigned_offsets(file)) {
		if (offset != file->f_pos) {
			file->f_pos = offset;
			file->f_version = 0;
		}
		retval = offset;
	}
out:
	mutex_unlock(&inode->i_mutex);
	return retval;
}

Project: linux
File: read_write.c

SYSCALL_DEFINE4(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;
}

Project: linux
File: read_write.c

COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
		const struct compat_iovec __user *,vec,
		unsigned long, vlen, loff_t, pos)
{
	return __compat_sys_pwritev64(fd, vec, vlen, pos);
}

Project: linux
File: compat_ioctl.c

static int serial_struct_ioctl(unsigned fd, unsigned cmd,
			struct serial_struct32 __user *ss32)
{
        typedef struct serial_struct32 SS32;
        int err;
        struct serial_struct ss;
        mm_segment_t oldseg = get_fs();
        __u32 udata;
	unsigned int base;

        if (cmd == TIOCSSERIAL) {
                if (!access_ok(VERIFY_READ, ss32, sizeof(SS32)))
                        return -EFAULT;
                if (__copy_from_user(&ss, ss32, offsetof(SS32, iomem_base)))
			return -EFAULT;
                if (__get_user(udata, &ss32->iomem_base))
			return -EFAULT;
                ss.iomem_base = compat_ptr(udata);
                if (__get_user(ss.iomem_reg_shift, &ss32->iomem_reg_shift) ||
		    __get_user(ss.port_high, &ss32->port_high))
			return -EFAULT;
                ss.iomap_base = 0UL;
        }
        set_fs(KERNEL_DS);
                err = sys_ioctl(fd,cmd,(unsigned long)(&ss));
        set_fs(oldseg);
        if (cmd == TIOCGSERIAL && err >= 0) {
                if (!access_ok(VERIFY_WRITE, ss32, sizeof(SS32)))
                        return -EFAULT;
                if (__copy_to_user(ss32,&ss,offsetof(SS32,iomem_base)))
			return -EFAULT;
		base = (unsigned long)ss.iomem_base  >> 32 ?
			0xffffffff : (unsigned)(unsigned long)ss.iomem_base;
		if (__put_user(base, &ss32->iomem_base) ||
		    __put_user(ss.iomem_reg_shift, &ss32->iomem_reg_shift) ||
		    __put_user(ss.port_high, &ss32->port_high))
			return -EFAULT;
        }
        return err;
}

Project: linux
File: read_write.c

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;
}

Project: linux
File: read_write.c

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);
}

Project: linux
File: read_write.c

static inline loff_t file_pos_read(struct file *file)
{
	return file->f_pos;
}

Project: linux
File: read_write.c

SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
		unsigned long, vlen)
{
	struct fd f = fdget_pos(fd);
	ssize_t ret = -EBADF;

	if (f.file) {
		loff_t pos = file_pos_read(f.file);
		ret = vfs_readv(f.file, vec, vlen, &pos);
		if (ret >= 0)
			file_pos_write(f.file, pos);
		fdput_pos(f);
	}

	if (ret > 0)
		add_rchar(current, ret);
	inc_syscr(current);
	return ret;
}

Project: linux
File: read_write.c

loff_t noop_llseek(struct file *file, loff_t offset, int whence)
{
	return file->f_pos;
}

Project: linux
File: read_write.c

generic_file_llseek_size(struct file *file, loff_t offset, int whence,
		loff_t maxsize, loff_t eof)
{
	switch (whence) {
	case SEEK_END:
		offset += eof;
		break;
	case SEEK_CUR:
		/*
		 * Here we special-case the lseek(fd, 0, SEEK_CUR)
		 * position-querying operation.  Avoid rewriting the "same"
		 * f_pos value back to the file because a concurrent read(),
		 * write() or lseek() might have altered it
		 */
		if (offset == 0)
			return file->f_pos;
		/*
		 * f_lock protects against read/modify/write race with other
		 * SEEK_CURs. Note that parallel writes and reads behave
		 * like SEEK_SET.
		 */
		spin_lock(&file->f_lock);
		offset = vfs_setpos(file, file->f_pos + offset, maxsize);
		spin_unlock(&file->f_lock);
		return offset;
	case SEEK_DATA:
		/*
		 * In the generic case the entire file is data, so as long as
		 * offset isn't at the end of the file then the offset is data.
		 */
		if (offset >= eof)
			return -ENXIO;
		break;
	case SEEK_HOLE:
		/*
		 * There is a virtual hole at the end of the file, so as long as
		 * offset isn't i_size or larger, return i_size.
		 */
		if (offset >= eof)
			return -ENXIO;
		offset = eof;
		break;
	}

	return vfs_setpos(file, offset, maxsize);
}

Project: linux
File: read_write.c

int vfs_clone_file_range(struct file *file_in, loff_t pos_in,
		struct file *file_out, loff_t pos_out, u64 len)
{
	struct inode *inode_in = file_inode(file_in);
	struct inode *inode_out = file_inode(file_out);
	int ret;

	if (inode_in->i_sb != inode_out->i_sb ||
	    file_in->f_path.mnt != file_out->f_path.mnt)
		return -EXDEV;

	if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
		return -EISDIR;
	if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
		return -EINVAL;

	if (!(file_in->f_mode & FMODE_READ) ||
	    !(file_out->f_mode & FMODE_WRITE) ||
	    (file_out->f_flags & O_APPEND) ||
	    !file_in->f_op->clone_file_range)
		return -EBADF;

	ret = clone_verify_area(file_in, pos_in, len, false);
	if (ret)
		return ret;

	ret = clone_verify_area(file_out, pos_out, len, true);
	if (ret)
		return ret;

	if (pos_in + len > i_size_read(inode_in))
		return -EINVAL;

	ret = mnt_want_write_file(file_out);
	if (ret)
		return ret;

	ret = file_in->f_op->clone_file_range(file_in, pos_in,
			file_out, pos_out, len);
	if (!ret) {
		fsnotify_access(file_in);
		fsnotify_modify(file_out);
	}

	mnt_drop_write_file(file_out);
	return ret;
}

Project: linux
File: read_write.c

ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos)
{
	struct kiocb kiocb;
	ssize_t ret;

	if (!file->f_op->write_iter)
		return -EINVAL;

	init_sync_kiocb(&kiocb, file);
	kiocb.ki_pos = *ppos;

	iter->type |= WRITE;
	ret = file->f_op->write_iter(&kiocb, iter);
	BUG_ON(ret == -EIOCBQUEUED);
	if (ret > 0)
		*ppos = kiocb.ki_pos;
	return ret;
}

Project: linux
File: read_write.c

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 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);
		fdput(f);
	}

	if (ret > 0)
		add_wchar(current, ret);
	inc_syscw(current);
	return ret;
}

Project: linux
File: read_write.c

SYSCALL_DEFINE4(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;
}

Project: linux
File: read_write.c

SYSCALL_DEFINE3(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 = file_pos_read(f.file);
		ret = vfs_write(f.file, buf, count, &pos);
		if (ret >= 0)
			file_pos_write(f.file, pos);
		fdput_pos(f);
	}

	return ret;
}

Project: linux
File: read_write.c

ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos)
{
	struct kiocb kiocb;
	ssize_t ret;

	if (!file->f_op->read_iter)
		return -EINVAL;

	init_sync_kiocb(&kiocb, file);
	kiocb.ki_pos = *ppos;

	iter->type |= READ;
	ret = file->f_op->read_iter(&kiocb, iter);
	BUG_ON(ret == -EIOCBQUEUED);
	if (ret > 0)
		*ppos = kiocb.ki_pos;
	return ret;
}

Project: linux
File: read_write.c

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);
}

Project: linux
File: read_write.c

static size_t compat_readv(struct file *file,
			   const struct compat_iovec __user *vec,
			   unsigned long vlen, loff_t *pos)
{
	ssize_t ret = -EBADF;

	if (!(file->f_mode & FMODE_READ))
		goto out;

	ret = -EINVAL;
	if (!(file->f_mode & FMODE_CAN_READ))
		goto out;

	ret = compat_do_readv_writev(READ, file, vec, vlen, pos);

out:
	if (ret > 0)
		add_rchar(current, ret);
	inc_syscr(current);
	return ret;
}

Project: linux
File: compat_ioctl.c

static int rtc_ioctl(unsigned fd, unsigned cmd, void __user *argp)
{
	mm_segment_t oldfs = get_fs();
	compat_ulong_t val32;
	unsigned long kval;
	int ret;

	switch (cmd) {
	case RTC_IRQP_READ32:
	case RTC_EPOCH_READ32:
		set_fs(KERNEL_DS);
		ret = sys_ioctl(fd, (cmd == RTC_IRQP_READ32) ?
					RTC_IRQP_READ : RTC_EPOCH_READ,
					(unsigned long)&kval);
		set_fs(oldfs);
		if (ret)
			return ret;
		val32 = kval;
		return put_user(val32, (unsigned int __user *)argp);
	case RTC_IRQP_SET32:
		return sys_ioctl(fd, RTC_IRQP_SET, (unsigned long)argp);
	case RTC_EPOCH_SET32:
		return sys_ioctl(fd, RTC_EPOCH_SET, (unsigned long)argp);
	}

	return -ENOIOCTLCMD;
}

Project: linux
File: read_write.c

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_mode & FMODE_CAN_READ))
		return -EINVAL;

	return do_readv_writev(READ, file, vec, vlen, pos);
}

Project: linux
File: read_write.c

static inline void file_pos_write(struct file *file, loff_t pos)
{
	file->f_pos = pos;
}

Project: linux
File: read_write.c

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 __compat_sys_preadv64(fd, vec, vlen, pos);
}

Project: linux
File: read_write.c

static inline struct fd fdget_pos(int fd)
{
	return __to_fd(__fdget_pos(fd));
}

Project: linux
File: read_write.c

loff_t no_llseek(struct file *file, loff_t offset, int whence)
{
	return -ESPIPE;
}

Project: linux
File: read_write.c

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;
}

Project: linux
File: read_write.c

ssize_t __vfs_write(struct file *file, const char __user *p, size_t count,
		    loff_t *pos)
{
	if (file->f_op->write)
		return file->f_op->write(file, p, count, pos);
	else if (file->f_op->write_iter)
		return new_sync_write(file, p, count, pos);
	else
		return -EINVAL;
}

Project: linux
File: read_write.c

COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
		const struct compat_iovec __user *,vec,
		unsigned long, vlen, loff_t, pos)
{
	return __compat_sys_preadv64(fd, vec, vlen, pos);
}

Project: linux
File: read_write.c

static int clone_verify_area(struct file *file, loff_t pos, u64 len, bool write)
{
	struct inode *inode = file_inode(file);

	if (unlikely(pos < 0))
		return -EINVAL;

	 if (unlikely((loff_t) (pos + len) < 0))
		return -EINVAL;

	if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
		loff_t end = len ? pos + len - 1 : OFFSET_MAX;
		int retval;

		retval = locks_mandatory_area(inode, file, pos, end,
				write ? F_WRLCK : F_RDLCK);
		if (retval < 0)
			return retval;
	}

	return security_file_permission(file, write ? MAY_WRITE : MAY_READ);
}

Project: linux
File: read_write.c

static inline int unsigned_offsets(struct file *file)
{
	return file->f_mode & FMODE_UNSIGNED_OFFSET;
}

Project: linux
File: read_write.c

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;
	struct iov_iter iter;
	ssize_t ret;
	io_fn_t fn;
	iter_fn_t iter_fn;

	ret = import_iovec(type, uvector, nr_segs,
			   ARRAY_SIZE(iovstack), &iov, &iter);
	if (ret < 0)
		return ret;

	tot_len = iov_iter_count(&iter);
	if (!tot_len)
		goto out;
	ret = rw_verify_area(type, file, pos, tot_len);
	if (ret < 0)
		goto out;

	if (type == READ) {
		fn = file->f_op->read;
		iter_fn = file->f_op->read_iter;
	} else {
		fn = (io_fn_t)file->f_op->write;
		iter_fn = file->f_op->write_iter;
		file_start_write(file);
	}

	if (iter_fn)
		ret = do_iter_readv_writev(file, &iter, pos, iter_fn);
	else
		ret = do_loop_readv_writev(file, &iter, pos, fn);

	if (type != READ)
		file_end_write(file);

out:
	kfree(iov);
	if ((ret + (type == READ)) > 0) {
		if (type == READ)
			fsnotify_access(file);
		else
			fsnotify_modify(file);
	}
	return ret;
}

Project: linux
File: read_write.c

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);
}

Project: linux
File: read_write.c

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;
	count = retval;

	/*
	 * 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;
	retval = -EINVAL;
	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;
	count = retval;

	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;
}

Project: linux
File: read_write.c

COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
		const struct compat_iovec __user *,vec,
		compat_ulong_t, vlen)
{
	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);
	if (ret >= 0)
		f.file->f_pos = pos;
	fdput_pos(f);
	return ret;
}

Project: linux
File: read_write.c

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;
}

Project: linux
File: read_write.c

loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize)
{
	if (offset < 0 && !unsigned_offsets(file))
		return -EINVAL;
	if (offset > maxsize)
		return -EINVAL;

	if (offset != file->f_pos) {
		file->f_pos = offset;
		file->f_version = 0;
	}
	return offset;
}

Project: linux
File: read_write.c

static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter,
		loff_t *ppos, io_fn_t fn)
{
	ssize_t ret = 0;

	while (iov_iter_count(iter)) {
		struct iovec iovec = iov_iter_iovec(iter);
		ssize_t nr;

		nr = fn(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;
}

Project: linux
File: read_write.c

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;
}

Project: linux
File: read_write.c

static inline void fdput_pos(struct fd f)
{
	if (f.flags & FDPUT_POS_UNLOCK)
		mutex_unlock(&f.file->f_pos_lock);
	fdput(f);
}