Clear Asan finding in VMAC under 32-bit inline ASM (GH #860)

This one has been nagging us for a while. Tested OK under i686 and x86_64.

1 files changed, 10 insertions, 11 deletions

diff --git a/vmac.cpp b/vmac.cpp
index 535cce21..cd5dcbc3 100644
--- a/vmac.cpp
+++ b/vmac.cpp
@@ -184,23 +184,21 @@ __attribute__ ((noinline))		// Intel Compiler 9.1 workaround
 #endif

 VMAC_Base::VHASH_Update_SSE2(const word64 *data, size_t blocksRemainingInWord64, int tagPart)

 {

-	CRYPTOPP_ASSERT(IsAlignedOn(m_polyState(),GetAlignmentOf<word64>()));

-	CRYPTOPP_ASSERT(IsAlignedOn(m_nhKey(),GetAlignmentOf<word64>()));

-

 	const word64 *nhK = m_nhKey();

 	word64 *polyS = (word64*)(void*)m_polyState();

 	word32 L1KeyLength = m_L1KeyLength;

 

-	// These are used in the ASM, but some analysis engines cnnot determine it.

-	CRYPTOPP_UNUSED(data); CRYPTOPP_UNUSED(tagPart); CRYPTOPP_UNUSED(L1KeyLength);

+	// These are used in the ASM, but some analysis services miss it.

+	CRYPTOPP_UNUSED(data); CRYPTOPP_UNUSED(tagPart);

+	CRYPTOPP_UNUSED(L1KeyLength);

 	CRYPTOPP_UNUSED(blocksRemainingInWord64);

 

 #ifdef __GNUC__

-	word32 temp;

+

 	__asm__ __volatile__

 	(

-	AS2(	mov		%%ebx, %0)

-	AS2(	mov		%1, %%ebx)

+	AS1(	push	%%ebx)

+	AS2(	mov		%0, %%ebx)

 	INTEL_NOPREFIX

 #else

 	#if defined(__INTEL_COMPILER)

@@ -419,10 +417,11 @@ VMAC_Base::VHASH_Update_SSE2(const word64 *data, size_t blocksRemainingInWord64,
 	AS_POP_IF86(	bp)

 	AS1(	emms)

 #ifdef __GNUC__

+	AS1(	pop		%%ebx)

 	ATT_PREFIX

-	AS2(	mov	%0, %%ebx)

-		: "=m" (temp)

-		: "m" (L1KeyLength), "c" (blocksRemainingInWord64), "S" (data), "D" (nhK+tagPart*2), "d" (m_isFirstBlock), "a" (polyS+tagPart*4)

+		:

+		: "m" (L1KeyLength), "c" (blocksRemainingInWord64), "S" (data),

+		  "D" (nhK+tagPart*2), "d" (m_isFirstBlock), "a" (polyS+tagPart*4)

 		: "memory", "cc"

 	);

 #endif