ext-cryptopp/ppc_power9.cpp
Jeffrey Walton 6028a6921a
Fix SIGILL in TestDARN() function
I thought this was due to trying to call the darn instruction even though g_hasDARN == false on Power8. However, the problem turned out to be a Power9 load was used when DARN class threw a DARN_Err.
2018-11-30 09:12:35 -05:00

131 lines
3.8 KiB
C++

// ppc_power9.cpp - written and placed in the public domain by
// Jeffrey Walton, Uri Blumenthal and Marcel Raad.
//
// This source file uses intrinsics and built-ins to gain access to
// Power9 instructions. A separate source file is needed because
// additional CXXFLAGS are required to enable the appropriate
// instructions sets in some build configurations.
#include "pch.h"
#include "config.h"
#ifdef CRYPTOPP_GNU_STYLE_INLINE_ASSEMBLY
# include <signal.h>
# include <setjmp.h>
#endif
#if defined(_ARCH_PWR9)
# include "ppc_simd.h"
#endif
// Squash MS LNK4221 and libtool warnings
extern const char PPC_POWER9_FNAME[] = __FILE__;
NAMESPACE_BEGIN(CryptoPP)
// ************************* Feature Probes ************************* //
#ifdef CRYPTOPP_GNU_STYLE_INLINE_ASSEMBLY
extern "C" {
typedef void (*SigHandler)(int);
static jmp_buf s_jmpSIGILL;
static void SigIllHandler(int)
{
longjmp(s_jmpSIGILL, 1);
}
}
#endif // CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY
#if (CRYPTOPP_BOOL_PPC32 || CRYPTOPP_BOOL_PPC64)
bool CPU_ProbePower9()
{
#if defined(CRYPTOPP_NO_CPU_FEATURE_PROBES)
return false;
#elif defined(CRYPTOPP_POWER9_AVAILABLE)
# if defined(CRYPTOPP_GNU_STYLE_INLINE_ASSEMBLY)
// longjmp and clobber warnings. Volatile is required.
// http://github.com/weidai11/cryptopp/issues/24 and http://stackoverflow.com/q/7721954
volatile int result = true;
volatile SigHandler oldHandler = signal(SIGILL, SigIllHandler);
if (oldHandler == SIG_ERR)
return false;
volatile sigset_t oldMask;
if (sigprocmask(0, NULLPTR, (sigset_t*)&oldMask))
return false;
if (setjmp(s_jmpSIGILL))
result = false;
else
{
// This is "darn r3, 0". It provides a conditioned 32-bit
// word. It is available on both 32-bit and 64-bit.
#if CRYPTOPP_BIG_ENDIAN
__asm__ __volatile__ (".byte 0x7c, 0x60, 0x05, 0xe6 \n" : : : "r3");
#else
__asm__ __volatile__ (".byte 0xe6, 0x05, 0x60, 0x7c \n" : : : "r3");
#endif
result = true;
}
sigprocmask(SIG_SETMASK, (sigset_t*)&oldMask, NULLPTR);
signal(SIGILL, oldHandler);
return result;
# endif
#else
return false;
#endif // _ARCH_PWR9
}
// The DARN probe is not guarded with a preprocessor macro at the moment. We
// don't use CRYPTOPP_POWER9_AVAILABLE because old compilers, like GCC 4.8 on
// CentOS 7, will report NO even though we can produce the random numbers.
// Other Power9 implementations which use builtins will use the preprocessor
// macro guard. This strategy also gets into a situation where Power9 is not
// available but DARN is.
bool CPU_ProbeDARN()
{
#if defined(CRYPTOPP_NO_CPU_FEATURE_PROBES)
return false;
#else
# if defined(CRYPTOPP_GNU_STYLE_INLINE_ASSEMBLY)
// longjmp and clobber warnings. Volatile is required.
// http://github.com/weidai11/cryptopp/issues/24 and http://stackoverflow.com/q/7721954
volatile int result = true;
volatile SigHandler oldHandler = signal(SIGILL, SigIllHandler);
if (oldHandler == SIG_ERR)
return false;
volatile sigset_t oldMask;
if (sigprocmask(0, NULLPTR, (sigset_t*)&oldMask))
return false;
if (setjmp(s_jmpSIGILL))
result = false;
else
{
// This is "darn r3, 0". It provides a conditioned 32-bit
// word. It is available on both 32-bit and 64-bit.
#if CRYPTOPP_BIG_ENDIAN
__asm__ __volatile__ (".byte 0x7c, 0x60, 0x05, 0xe6 \n" : : : "r3");
#else
__asm__ __volatile__ (".byte 0xe6, 0x05, 0x60, 0x7c \n" : : : "r3");
#endif
result = true;
}
sigprocmask(SIG_SETMASK, (sigset_t*)&oldMask, NULLPTR);
signal(SIGILL, oldHandler);
return result;
# endif
#endif // DARN
}
#endif // PPC32 or PPC64
NAMESPACE_END