[PATCH 04/11] kselftest/arm64: mte: user_mem: Fix write() warning

[Andre Przywara]

Out of the box Ubuntu's 20.04 compiler warns about missing return value
checks for write() (sys)calls.

Make GCC happy by checking whether we actually managed to write "val".

Signed-off-by: Andre Przywara <andre.przywara at arm.com>
---
 tools/testing/selftests/arm64/mte/check_user_mem.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/arm64/mte/check_user_mem.c b/tools/testing/selftests/arm64/mte/check_user_mem.c
index 4bfa80f2a8c3..1de7a0abd0ae 100644
--- a/tools/testing/selftests/arm64/mte/check_user_mem.c
+++ b/tools/testing/selftests/arm64/mte/check_user_mem.c
@@ -33,7 +33,8 @@ static int check_usermem_access_fault(int mem_type, int mode, int mapping)
 	if (fd == -1)
 		return KSFT_FAIL;
 	for (i = 0; i < len; i++)
-		write(fd, &val, sizeof(val));
+		if (write(fd, &val, sizeof(val)) != sizeof(val))
+			return KSFT_FAIL;
 	lseek(fd, 0, 0);
 	ptr = mte_allocate_memory(len, mem_type, mapping, true);
 	if (check_allocated_memory(ptr, len, mem_type, true) != KSFT_PASS) {
-- 
2.17.5