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From: Colin Ian King <colin.i.king@gmail.com>
To: Sean Christopherson <seanjc@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Shuah Khan <shuah@kernel.org>,
	kvm@vger.kernel.org, linux-kselftest@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH][next][V2] selftests: kvm: fix shift of 32 bit unsigned int more than 32 bits
Date: Thu, 23 May 2024 16:41:02 +0100	[thread overview]
Message-ID: <20240523154102.2236133-1-colin.i.king@gmail.com> (raw)

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>

---

V2: Fix incorrect variable in 2nd BIT_ULL(), kudos to Dan Carpenter for
    catching this error.

---
 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(i))
 			test_init2(vm_type,
 				&(struct kvm_sev_init){ .vmsa_features = BIT_ULL(i) });
 	}
-- 
2.39.2


             reply	other threads:[~2024-05-23 15:41 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-23 15:41 Colin Ian King [this message]
2024-06-04 23:29 ` [PATCH][next][V2] selftests: kvm: fix shift of 32 bit unsigned int more than 32 bits Sean Christopherson

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