Add runtime detection code for ARM NEON, CRC32 and Crypto extensions

cpu.cpp

@@ -24,10 +24,17 @@
 
 NAMESPACE_BEGIN(CryptoPP)
 
+#ifndef CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY
+
 // MacPorts/GCC does not provide constructor(priority). Apple/GCC and Fink/GCC do provide it.
 #define HAVE_GCC_CONSTRUCTOR1 (__GNUC__ && (CRYPTOPP_INIT_PRIORITY > 0) && ((CRYPTOPP_GCC_VERSION >= 40300) || (CRYPTOPP_CLANG_VERSION >= 20900) || (_INTEL_COMPILER >= 300)) && !(MACPORTS_GCC_COMPILER > 0))
 #define HAVE_GCC_CONSTRUCTOR0 (__GNUC__ && (CRYPTOPP_INIT_PRIORITY > 0) && !(MACPORTS_GCC_COMPILER > 0))
 
+extern "C" {
+    typedef void (*SigHandler)(int);
+};
+#endif  // Not CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY
+
 #ifdef CRYPTOPP_CPUID_AVAILABLE
 
 #if _MSC_VER >= 1400 && CRYPTOPP_BOOL_X64
@@ -42,7 +49,6 @@ bool CpuId(word32 input, word32 output[4])
 
 #ifndef CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY
 extern "C" {
-typedef void (*SigHandler)(int);
 
 static jmp_buf s_jmpNoCPUID;
 static void SigIllHandlerCPUID(int)
@@ -258,9 +264,189 @@ void DetectX86Features()
 bool g_ArmDetectionDone = false;
 bool g_hasNEON = false, g_hasCRC32 = false, g_hasCrypto = false;
 
-// This is avaiable in a status register, but we need privileged code to perform the read
 word32 g_cacheLineSize = CRYPTOPP_L1_CACHE_LINE_SIZE;
 
+// The ARM equivalent of CPUID is reading a MSR. For example, fetch crypto capabilities with:
+//   #if defined(__arm64__) || defined(__aarch64__)
+//	   word64 caps = 0;  // Read ID_AA64ISAR0_EL1
+//	   __asm __volatile("mrs %0, " "id_aa64isar0_el1" : "=r" (caps));
+//   #elif defined(__arm__) || defined(__aarch32__)
+//	   word32 caps = 0;  // Read ID_ISAR5_EL1
+//	   __asm __volatile("mrs %0, " "id_isar5_el1" : "=r" (caps));
+//   #endif
+// The code requires Exception Level 1 (EL1) and above, but user space runs at EL0.
+//   Attempting to run the code results in a SIGILL and termination.
+
+#ifndef CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY
+extern "C" {
+
+	static jmp_buf s_jmpNoNEON;
+	static void SigIllHandlerNEON(int)
+	{
+		longjmp(s_jmpNoNEON, 1);
+	}
+
+	static jmp_buf s_jmpNoCRC32;
+	static void SigIllHandlerCRC32(int)
+	{
+		longjmp(s_jmpNoCRC32, 1);
+	}
+
+	static jmp_buf s_jmpNoCrypto;
+	static void SigIllHandlerCrypto(int)
+	{
+		longjmp(s_jmpNoCrypto, 1);
+	}
+};
+#endif  // Not CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY
+
+static bool TryNEON()
+{
+#if (CRYPTOPP_BOOL_NEON_INTRINSICS_AVAILABLE)
+# if defined(CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY)
+	__try
+	{
+		static const uint32_t v1[4] = {1,1,1,1};
+		uint32x4_t x1 = vld1q_u32(v1);
+		static const uint64_t v2[2] = {1,1};
+		uint64x2_t x2 = vld1q_u64(v2);
+
+		uint32x4_t x3 = vdupq_n_u32(0);
+		x3 = vsetq_lane_u32(vgetq_lane_u32(x1,0),x3,0);
+		x3 = vsetq_lane_u32(vgetq_lane_u32(x1,3),x3,3);
+		uint64x2_t x4 = vdupq_n_u64(0);
+		x4 = vsetq_lane_u64(vgetq_lane_u64(x2,0),x4,0);
+		x4 = vsetq_lane_u64(vgetq_lane_u64(x2,1),x4,1);
+	}
+	__except (EXCEPTION_EXECUTE_HANDLER)
+	{
+		return false;
+	}
+	return true;
+# else
+	// longjmp and clobber warnings. Volatile is required.
+	// http://github.com/weidai11/cryptopp/issues/24
+	// http://stackoverflow.com/q/7721854
+	volatile bool result = true;
+
+	SigHandler oldHandler = signal(SIGILL, SigIllHandlerNEON);
+	if (oldHandler == SIG_ERR)
+		result = false;
+
+	if (setjmp(s_jmpNoNEON))
+		result = false;
+	else
+	{
+		static const uint32_t v1[4] = {1,1,1,1};
+		uint32x4_t x1 = vld1q_u32(v1);
+		static const uint64_t v2[2] = {1,1};
+		uint64x2_t x2 = vld1q_u64(v2);
+
+		uint32x4_t x3 = vdupq_n_u32(0);
+		x3 = vsetq_lane_u32(vgetq_lane_u32(x1,0),x3,0);
+		x3 = vsetq_lane_u32(vgetq_lane_u32(x1,3),x3,3);
+		uint64x2_t x4 = vdupq_n_u64(0);
+		x4 = vsetq_lane_u64(vgetq_lane_u64(x2,0),x4,0);
+		x4 = vsetq_lane_u64(vgetq_lane_u64(x2,1),x4,1);
+	}
+
+	signal(SIGILL, oldHandler);
+	return result;
+# endif
+#else
+	return false;
+#endif  // CRYPTOPP_BOOL_NEON_INTRINSICS_AVAILABLE
+}
+
+static bool TryCRC32()
+{
+#if (CRYPTOPP_BOOL_ARM_CRC32_INTRINSICS_AVAILABLE)
+# if defined(CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY)
+	__try
+	{
+		word32 w=0, x=0; word16 y=0; byte z=0;
+		w = __crc32cw(w,x);
+		w = __crc32ch(w,y);
+		w = __crc32cb(w,z);
+	}
+	__except (EXCEPTION_EXECUTE_HANDLER)
+	{
+		return false;
+	}
+	return true;
+# else
+	// longjmp and clobber warnings. Volatile is required.
+	// http://github.com/weidai11/cryptopp/issues/24
+	// http://stackoverflow.com/q/7721854
+	volatile bool result = true;
+
+	SigHandler oldHandler = signal(SIGILL, SigIllHandlerCRC32);
+	if (oldHandler == SIG_ERR)
+		result = false;
+
+	if (setjmp(s_jmpNoCRC32))
+		result = false;
+	else
+	{
+		word32 w=0, x=0; word16 y=0; byte z=0;
+		w = __crc32cw(w,x);
+		w = __crc32ch(w,y);
+		w = __crc32cb(w,z);
+	}
+
+	signal(SIGILL, oldHandler);
+	return result;
+# endif
+#else
+	return false;
+#endif  // CRYPTOPP_BOOL_ARM_CRC32_INTRINSICS_AVAILABLE
+}
+
+static bool TryCrypto()
+{
+#if (CRYPTOPP_BOOL_ARM_CRYPTO_INTRINSICS_AVAILABLE)
+# if defined(CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY)
+	__try
+	{
+		// AES encrypt and decrypt
+		static const uint8x16_t data = vdupq_n_u8(0), key = vdupq_n_u8(0); 
+		uint8x16_t r1 = vaeseq_u8(data, key);
+		uint8x16_t r2 = vaesdq_u8(data, key);
+
+		// 
+	}
+	__except (EXCEPTION_EXECUTE_HANDLER)
+	{
+		return false;
+	}
+	return true;
+# else
+	// longjmp and clobber warnings. Volatile is required.
+	// http://github.com/weidai11/cryptopp/issues/24
+	// http://stackoverflow.com/q/7721854
+	volatile bool result = true;
+
+	SigHandler oldHandler = signal(SIGILL, SigIllHandlerCrypto);
+	if (oldHandler == SIG_ERR)
+		result = false;
+
+	if (setjmp(s_jmpNoCrypto))
+		result = false;
+	else
+	{
+		static const uint8x16_t data = vdupq_n_u8(0), key = vdupq_n_u8(0); 
+		uint8x16_t r1 = vaeseq_u8(data, key);
+		uint8x16_t r2 = vaesdq_u8(data, key);
+	}
+
+	signal(SIGILL, oldHandler);
+	return result;
+# endif
+#else
+	return false;
+#endif  // CRYPTOPP_BOOL_ARM_CRYPTO_INTRINSICS_AVAILABLE
+}
+
 #if HAVE_GCC_CONSTRUCTOR1
 void __attribute__ ((constructor (CRYPTOPP_INIT_PRIORITY + 50))) DetectArmFeatures()
 #elif HAVE_GCC_CONSTRUCTOR0
@@ -269,43 +455,10 @@ void __attribute__ ((constructor)) DetectArmFeatures()
 void DetectArmFeatures()
 #endif
 {
-#if defined(__linux__) && defined(__aarch64__) // ARM-64
+	g_hasNEON = TryNEON();
-	const unsigned long hwcaps = getauxval(AT_HWCAP);
+	g_hasCRC32 = TryCRC32();
-	g_hasNEON = !!(hwcaps & HWCAP_ASIMD);
+	g_hasCrypto = TryCrypto();
-# if defined(__ARM_FEATURE_CRC32)
+
-	g_hasCRC32 = !!(hwcaps & HWCAP_CRC32);
-# else
-	g_hasCRC32 = false;
-# endif
-#elif defined(__linux__) // ARM-32
-	const unsigned long hwcaps = getauxval(AT_HWCAP);
-	g_hasNEON = !!(hwcaps & HWCAP_ARM_NEON);
-# if defined(__ARM_FEATURE_CRC32)
-	g_hasCRC32 = !!(hwcaps & HWCAP_ARM_CRC32);
-# else
-	g_hasCRC32 = false;
-# endif
-#elif defined(__APPLE__)
-	g_hasNEON = true;
-# if defined(__ARM_FEATURE_CRC32)
-	g_hasCRC32 = true;
-# else
-	g_hasCRC32 = false;
-# endif
-# if defined(__ARM_FEATURE_CRYPTO)
-	g_hasCrypto = true;
-# else
-	g_hasCrypto = false;
-# endif
-#elif defined(_WIN32)
-	g_hasNEON = true;
-	g_hasCRC32 = false;
-	g_hasCrypto = false;
-#else
-	g_hasNEON = false;
-	g_hasCRC32 = false;
-	g_hasCrypto = false;
-#endif
 	*((volatile bool*)&g_ArmDetectionDone) = true;
 }
 

cpu.h

@@ -12,17 +12,20 @@
 #include "config.h"
 
 #if (CRYPTOPP_BOOL_ARM32 || CRYPTOPP_BOOL_ARM64)
-# if defined(__linux__)
+# if defined(_MSC_VER) || defined(__BORLANDC__)
-#  include <sys/auxv.h>
+#  define CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY
-#  include <asm/hwcap.h>
+# else
-#  include <stdint.h>
+#  define CRYPTOPP_GNU_STYLE_INLINE_ASSEMBLY
 # endif
 # if CRYPTOPP_BOOL_NEON_INTRINSICS_AVAILABLE
 #  include <arm_neon.h>
 # endif
-# if (defined(__ARM_FEATURE_CRC32) || defined(__ARM_FEATURE_CRYPTO) || (__ARM_ACLE >= 200)) && !defined(__APPLE__)
+# if (CRYPTOPP_BOOL_ARM_CRYPTO_INTRINSICS_AVAILABLE || CRYPTOPP_BOOL_ARM_CRC32_INTRINSICS_AVAILABLE)
+#  include <stdint.h>
+#  if (defined(__ARM_ACLE) || defined(__GNUC__)) && !defined(__APPLE__)
 #   include <arm_acle.h>
 #  endif
+# endif
 #endif  // ARM-32 or ARM-64
 
 #ifdef CRYPTOPP_GENERATE_X64_MASM
@@ -242,6 +245,7 @@ void CRYPTOPP_API DetectArmFeatures();
 
 //! \brief Determine if an ARM processor has Advanced SIMD available
 //! \returns true if the hardware is capable of Advanced SIMD at runtime, false otherwise.
+//! \details Advanced SIMD instructions are available under Aarch64 (ARM-64) and Aarch32 (ARM-32).
 //! \details Runtime support requires compile time support. When compiling with GCC, you may
 //!   need to compile with <tt>-mfpu=neon</tt> (32-bit) or <tt>-march=armv8-a</tt>
 //!   (64-bit). Also see ARM's <tt>__ARM_NEON</tt> preprocessor macro.
@@ -254,9 +258,12 @@ inline bool HasNEON()
 
 //! \brief Determine if an ARM processor has CRC32 available
 //! \returns true if the hardware is capable of CRC32 at runtime, false otherwise.
+//! \details CRC32 instructions provide access to the processor's CRC32 and CRC32-C intructions.
+//!   They are provided by ARM C Language Extensions 2.0 (ACLE 2.0) and available under Aarch64
+//!   (ARM-64) and Aarch32 (ARM-32) running on Aarch64 (i.e., an AArch32 execution environment).
 //! \details Runtime support requires compile time support. When compiling with GCC, you may
-//!   need to compile with <tt>-march=armv8-a+crc</tt>. Also see ARM's <tt>__ARM_FEATURE_CRC32</tt>
+//!   need to compile with <tt>-march=armv8-a+crc</tt>; while Apple requires
-//!   preprocessor macro.
+//!   <tt>-arch arm64</tt>. Also see ARM's <tt>__ARM_FEATURE_CRC32</tt> preprocessor macro.
 inline bool HasCRC32()
 {
 	if (!g_ArmDetectionDone)
@@ -266,10 +273,12 @@ inline bool HasCRC32()
 
 //! \brief Determine if an ARM processor has Crypto available
 //! \returns true if the hardware is capable of Crypto at runtime, false otherwise.
+//! \details Crypto instructions provide access to the processor's AES, SHA-1, SHA-224 and SHA-256 intructions.
+//!   They are provided by ARM C Language Extensions 2.0 (ACLE 2.0) and available under Aarch64
+//!   (ARM-64) and Aarch32 (ARM-32) running on Aarch64 (i.e., an AArch32 execution environment).
 //! \details Runtime support requires compile time support. When compiling with GCC, you may
 //!   need to compile with <tt>-march=armv8-a+crypto</tt>; while Apple requires
-//!   <tt>-arch armv7s</tt> or <tt>-arch arm64</tt>. Also see ARM's <tt>__ARM_FEATURE_CRYPTO</tt>
+//!   <tt>-arch arm64</tt>. Also see ARM's <tt>__ARM_FEATURE_CRYPTO</tt> preprocessor macro.
-//!   preprocessor macro.
 inline bool HasCrypto()
 {
 	if (!g_ArmDetectionDone)