[PATCH 5.18 114/181] s390/crash: make copy_oldmem_page() return number of bytes copied

[Greg Kroah-Hartman]

From: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>

[ Upstream commit af2debd58bd769e38f538143f0d332e15d753396 ]

Callback copy_oldmem_page() returns either error code or zero.
Instead, it should return the error code or number of bytes copied.

Fixes: df9694c7975f ("s390/dump: streamline oldmem copy functions")
Reviewed-by: Alexander Egorenkov <egorenar@xxxxxxxxxxxxx>
Tested-by: Alexander Egorenkov <egorenar@xxxxxxxxxxxxx>
Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 arch/s390/kernel/crash_dump.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/arch/s390/kernel/crash_dump.c
+++ b/arch/s390/kernel/crash_dump.c
@@ -233,9 +233,10 @@ ssize_t copy_oldmem_page(struct iov_iter
 		rc = copy_oldmem_user(iter->iov->iov_base, src, csize);
 	else
 		rc = copy_oldmem_kernel(iter->kvec->iov_base, src, csize);
-	if (!rc)
-		iov_iter_advance(iter, csize);
-	return rc;
+	if (rc < 0)
+		return rc;
+	iov_iter_advance(iter, csize);
+	return csize;
 }
 
 /*