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[next] selftests: kvm: fix shift of 32 bit unsigned int more than 32 bits

Message ID 20240523113802.2195703-1-colin.i.king@gmail.com (mailing list archive)
State New, archived
Headers show
Series [next] selftests: kvm: fix shift of 32 bit unsigned int more than 32 bits | expand

Commit Message

Colin Ian King May 23, 2024, 11:38 a.m. UTC
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@gmail.com>
---
 tools/testing/selftests/kvm/x86_64/sev_init2_tests.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Dan Carpenter May 23, 2024, 3:35 p.m. UTC | #1
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@gmail.com>
> ---
>  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

regards,
dan carpenter
Colin Ian King May 23, 2024, 3:37 p.m. UTC | #2
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@gmail.com>
>> ---
>>   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
>
diff mbox series

Patch

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))
 			test_init2(vm_type,
 				&(struct kvm_sev_init){ .vmsa_features = BIT_ULL(i) });
 	}