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, 3 insertions, 4 deletions

diff --git a/arch/s390/kernel/os_info.c b/arch/s390/kernel/os_info.c
index a2b08d3f53ec..6b5b64e67eee 100644
--- a/arch/s390/kernel/os_info.c
+++ b/arch/s390/kernel/os_info.c
@@ -91,7 +91,7 @@ static void os_info_old_alloc(int nr, int align)
 		goto fail;
 	}
 	buf_align = PTR_ALIGN(buf, align);
-	if (copy_oldmem_kernel(buf_align, (void *) addr, size)) {
+	if (copy_oldmem_kernel(buf_align, addr, size)) {
 		msg = "copy failed";
 		goto fail_free;
 	}
@@ -124,15 +124,14 @@ static void os_info_old_init(void)
 		return;
 	if (!oldmem_data.start)
 		goto fail;
-	if (copy_oldmem_kernel(&addr, (void *)__LC_OS_INFO, sizeof(addr)))
+	if (copy_oldmem_kernel(&addr, __LC_OS_INFO, sizeof(addr)))
 		goto fail;
 	if (addr == 0 || addr % PAGE_SIZE)
 		goto fail;
 	os_info_old = kzalloc(sizeof(*os_info_old), GFP_KERNEL);
 	if (!os_info_old)
 		goto fail;
-	if (copy_oldmem_kernel(os_info_old, (void *) addr,
-			       sizeof(*os_info_old)))
+	if (copy_oldmem_kernel(os_info_old, addr, sizeof(*os_info_old)))
 		goto fail_free;
 	if (os_info_old->magic != OS_INFO_MAGIC)
 		goto fail_free;