diff options
| author | Nikos Mavrogiannopoulos <nmav@gnutls.org> | 2017-01-15 10:40:02 +0100 |
|---|---|---|
| committer | Nikos Mavrogiannopoulos <nmav@redhat.com> | 2017-01-18 09:32:55 +0100 |
| commit | 09db170c9269c675491781a151626369ddc2c4d7 (patch) | |
| tree | fe83da672ee0098a45e16914bb59879bd6d9036a /lib | |
| parent | 61009ee749a27c90d141e3d4b2ebaebe9934422d (diff) | |
| download | gnutls-09db170c9269c675491781a151626369ddc2c4d7.tar.gz | |
Disable AVX support when it is not supported by the CPUtmp-fix-movbe-run
This mostly affects virtual systems. Reported by Frank Chen.
Signed-off-by: Nikos Mavrogiannopoulos <nmav@gnutls.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/accelerated/x86/x86-common.c | 33 |
1 files changed, 31 insertions, 2 deletions
diff --git a/lib/accelerated/x86/x86-common.c b/lib/accelerated/x86/x86-common.c index dcd74a4f94..353a252909 100644 --- a/lib/accelerated/x86/x86-common.c +++ b/lib/accelerated/x86/x86-common.c @@ -64,6 +64,11 @@ unsigned int _gnutls_x86_cpuid_s[4]; # define bit_AVX 0x10000000 #endif +#ifndef OSXSAVE_MASK +/* OSXSAVE|FMA|MOVBE */ +# define OSXSAVE_MASK (0x8000000|0x1000|0x400000) +#endif + #ifndef bit_MOVBE # define bit_MOVBE 0x00400000 #endif @@ -83,6 +88,26 @@ unsigned int _gnutls_x86_cpuid_s[4]; #define VIA_PADLOCK_PHE (1<<21) #define VIA_PADLOCK_PHE_SHA512 (1<<22) +/* Based on the example in "How to detect New Instruction support in + * the 4th generation Intel Core processor family. + * https://software.intel.com/en-us/articles/how-to-detect-new-instruction-support-in-the-4th-generation-intel-core-processor-family + */ +static unsigned check_4th_gen_intel_features(unsigned ecx) +{ + uint32_t xcr0; + + if ((ecx & OSXSAVE_MASK) != OSXSAVE_MASK) + return 0; + +#if defined(_MSC_VER) + xcr0 = _xgetbv(0); +#else + __asm__ ("xgetbv" : "=a" (xcr0) : "c" (0) : "%edx"); +#endif + /* Check if xmm and ymm state are enabled in XCR0. */ + return (xcr0 & 6) == 6; +} + static void capabilities_to_intel_cpuid(unsigned capabilities) { unsigned a,b,c,t; @@ -114,7 +139,7 @@ static void capabilities_to_intel_cpuid(unsigned capabilities) } if (capabilities & INTEL_AVX) { - if ((b & bit_AVX) && (b & bit_MOVBE)) { + if ((b & bit_AVX) && check_4th_gen_intel_features(b)) { _gnutls_x86_cpuid_s[1] |= bit_AVX|bit_MOVBE; } else { _gnutls_debug_log @@ -133,6 +158,7 @@ static void capabilities_to_intel_cpuid(unsigned capabilities) } + static unsigned check_optimized_aes(void) { return (_gnutls_x86_cpuid_s[1] & bit_AES); @@ -146,7 +172,10 @@ static unsigned check_ssse3(void) #ifdef ASM_X86_64 static unsigned check_avx_movbe(void) { - return ((_gnutls_x86_cpuid_s[1] & bit_AVX) && (_gnutls_x86_cpuid_s[1] & bit_MOVBE)); + if (check_4th_gen_intel_features(_gnutls_x86_cpuid_s[1]) == 0) + return 0; + + return ((_gnutls_x86_cpuid_s[1] & bit_AVX)); } static unsigned check_pclmul(void) |