s390/maccess: fix semantics of memcpy_real() and its callers

There is a confusion with regard to the source address of
memcpy_real() and calling functions. While the declared
type for a source assumes a virtual address, in fact it
always called with physical address of the source.

This confusion led to bugs in copy_oldmem_kernel() and
copy_oldmem_user() functions, where __pa() macro applied
mistakenly to physical addresses. It does not lead to a
real issue, since virtual and physical addresses are
currently the same.

Fix both the bugs and memcpy_real() prototype by making
type of source address consistent to the function name
and the way it actually used.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index d4d311cb2bb5..4cc5020f4e18 100644
--- a/arch/s390/mm/maccess.c
+++ b/arch/s390/mm/maccess.c
@@ -121,7 +121,7 @@ static unsigned long __no_sanitize_address _memcpy_real(unsigned long dest,
 /*
  * Copy memory in real mode (kernel to kernel)
  */
-int memcpy_real(void *dest, void *src, size_t count)
+int memcpy_real(void *dest, unsigned long src, size_t count)
 {
 	unsigned long _dest  = (unsigned long)dest;
 	unsigned long _src   = (unsigned long)src;
@@ -173,7 +173,7 @@ void memcpy_absolute(void *dest, void *src, size_t count)
 /*
  * Copy memory from kernel (real) to user (virtual)
  */
-int copy_to_user_real(void __user *dest, void *src, unsigned long count)
+int copy_to_user_real(void __user *dest, unsigned long src, unsigned long count)
 {
 	int offs = 0, size, rc;
 	char *buf;