[PATCH AUTOSEL 5.4 09/11] selftests:kvm: fix get_warnings_count() ignoring fscanf() return warn

From: Sasha Levin
Date: Tue Sep 28 2021 - 02:01:25 EST


From: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>

[ Upstream commit 39a71f712d8a13728febd8f3cb3f6db7e1fa7221 ]

Fix get_warnings_count() to check fscanf() return value to get rid
of the following warning:

x86_64/mmio_warning_test.c: In function ‘get_warnings_count’:
x86_64/mmio_warning_test.c:85:2: warning: ignoring return value of ‘fscanf’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
85 | fscanf(f, "%d", &warnings);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/testing/selftests/kvm/x86_64/mmio_warning_test.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c b/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c
index 00bb97d76000..2cbc09aad7f6 100644
--- a/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c
+++ b/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c
@@ -82,7 +82,8 @@ int get_warnings_count(void)
FILE *f;

f = popen("dmesg | grep \"WARNING:\" | wc -l", "r");
- fscanf(f, "%d", &warnings);
+ if (fscanf(f, "%d", &warnings) < 1)
+ warnings = 0;
fclose(f);

return warnings;
--
2.33.0