Re: [PATCH][next] selftests: kvm: fix shift of 32 bit unsigned int more than 32 bits
From: Colin King (gmail)
Date: Thu May 23 2024 - 11:37:29 EST
On 23/05/2024 16:35, Dan Carpenter wrote:
On Thu, May 23, 2024 at 12:38:02PM +0100, Colin Ian King wrote:
Currrentl a 32 bit 1u value is being shifted more than 32 bits causing
overflow and incorrect checking of bits 32-63. Fix this by using the
BIT_ULL macro for shifting bits.
Detected by cppcheck:
sev_init2_tests.c:108:34: error: Shifting 32-bit value by 63 bits is
undefined behaviour [shiftTooManyBits]
Fixes: dfc083a181ba ("selftests: kvm: add tests for KVM_SEV_INIT2")
Signed-off-by: Colin Ian King <colin.i.king@xxxxxxxxx>
---
tools/testing/selftests/kvm/x86_64/sev_init2_tests.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kvm/x86_64/sev_init2_tests.c b/tools/testing/selftests/kvm/x86_64/sev_init2_tests.c
index 7a4a61be119b..ea09f7a06aa4 100644
--- a/tools/testing/selftests/kvm/x86_64/sev_init2_tests.c
+++ b/tools/testing/selftests/kvm/x86_64/sev_init2_tests.c
@@ -105,11 +105,11 @@ void test_features(uint32_t vm_type, uint64_t supported_features)
int i;
for (i = 0; i < 64; i++) {
- if (!(supported_features & (1u << i)))
+ if (!(supported_features & BIT_ULL(i)))
test_init2_invalid(vm_type,
&(struct kvm_sev_init){ .vmsa_features = BIT_ULL(i) },
"unknown feature");
- else if (KNOWN_FEATURES & (1u << i))
+ else if (KNOWN_FEATURES & BIT_ULL(u))
^
Should be i. How does this build? :P
good catch, I sent the wrong one :-(
regards,
dan carpenter