Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f5029855 authored by Al Viro's avatar Al Viro
Browse files

move compat_rw_copy_check_uvector() over to fs/read_write.c 



Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 2b891026

fs/compat.c

+0 −76
Original line number Diff line number Diff line
@@ -54,82 +54,6 @@ 
#include <asm/ioctls.h>

#include "internal.h"



/* A write operation does a read from user space and vice versa */

#define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ)



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(nr_segs*sizeof(struct iovec), GFP_KERNEL);

		if (iov == NULL)

			goto out;

	}

	*ret_pointer = iov;



	ret = -EFAULT;

	if (!access_ok(VERIFY_READ, 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(vrfy_dir(type), 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;

}



struct compat_ncp_mount_data {

	compat_int_t version;

	compat_uint_t ncp_fd;

fs/read_write.c

+75 −0
Original line number Diff line number Diff line
@@ -841,6 +841,81 @@ ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, 
	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(nr_segs*sizeof(struct iovec), GFP_KERNEL);

		if (iov == NULL)

			goto out;

	}

	*ret_pointer = iov;



	ret = -EFAULT;

	if (!access_ok(VERIFY_READ, 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(vrfy_dir(type), 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_readv_writev(int type, struct file *file,

				 struct iov_iter *iter, loff_t *pos, int flags)

{