diff options
Diffstat (limited to 'crypto/cpuid.c')
| -rw-r--r-- | crypto/cpuid.c | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/crypto/cpuid.c b/crypto/cpuid.c new file mode 100644 index 0000000000..090f6fe03e --- /dev/null +++ b/crypto/cpuid.c @@ -0,0 +1,214 @@ +/* + * Copyright 1998-2021 The OpenSSL Project Authors. All Rights Reserved. + * + * Licensed under the Apache License 2.0 (the "License"). You may not use + * this file except in compliance with the License. You can obtain a copy + * in the file LICENSE in the source distribution or at + * https://www.openssl.org/source/license.html + */ + +#include "e_os.h" +#include "crypto/cryptlib.h" + +#if defined(__i386) || defined(__i386__) || defined(_M_IX86) || \ + defined(__x86_64) || defined(__x86_64__) || \ + defined(_M_AMD64) || defined(_M_X64) + +extern unsigned int OPENSSL_ia32cap_P[4]; + +# if defined(OPENSSL_CPUID_OBJ) + +/* + * Purpose of these minimalistic and character-type-agnostic subroutines + * is to break dependency on MSVCRT (on Windows) and locale. This makes + * OPENSSL_cpuid_setup safe to use as "constructor". "Character-type- + * agnostic" means that they work with either wide or 8-bit characters, + * exploiting the fact that first 127 characters can be simply casted + * between the sets, while the rest would be simply rejected by ossl_is* + * subroutines. + */ +# ifdef _WIN32 +typedef WCHAR variant_char; + +static variant_char *ossl_getenv(const char *name) +{ + /* + * Since we pull only one environment variable, it's simpler to + * to just ignore |name| and use equivalent wide-char L-literal. + * As well as to ignore excessively long values... + */ + static WCHAR value[48]; + DWORD len = GetEnvironmentVariableW(L"OPENSSL_ia32cap", value, 48); + + return (len > 0 && len < 48) ? value : NULL; +} +# else +typedef char variant_char; +# define ossl_getenv getenv +# endif + +# include "crypto/ctype.h" + +static int todigit(variant_char c) +{ + if (ossl_isdigit(c)) + return c - '0'; + else if (ossl_isxdigit(c)) + return ossl_tolower(c) - 'a' + 10; + + /* return largest base value to make caller terminate the loop */ + return 16; +} + +static uint64_t ossl_strtouint64(const variant_char *str) +{ + uint64_t ret = 0; + unsigned int digit, base = 10; + + if (*str == '0') { + base = 8, str++; + if (ossl_tolower(*str) == 'x') + base = 16, str++; + } + + while((digit = todigit(*str++)) < base) + ret = ret * base + digit; + + return ret; +} + +static variant_char *ossl_strchr(const variant_char *str, char srch) +{ variant_char c; + + while((c = *str)) { + if (c == srch) + return (variant_char *)str; + str++; + } + + return NULL; +} + +# define OPENSSL_CPUID_SETUP +typedef uint64_t IA32CAP; + +void OPENSSL_cpuid_setup(void) +{ + static int trigger = 0; + IA32CAP OPENSSL_ia32_cpuid(unsigned int *); + IA32CAP vec; + const variant_char *env; + + if (trigger) + return; + + trigger = 1; + if ((env = ossl_getenv("OPENSSL_ia32cap")) != NULL) { + int off = (env[0] == '~') ? 1 : 0; + + vec = ossl_strtouint64(env + off); + + if (off) { + IA32CAP mask = vec; + vec = OPENSSL_ia32_cpuid(OPENSSL_ia32cap_P) & ~mask; + if (mask & (1<<24)) { + /* + * User disables FXSR bit, mask even other capabilities + * that operate exclusively on XMM, so we don't have to + * double-check all the time. We mask PCLMULQDQ, AMD XOP, + * AES-NI and AVX. Formally speaking we don't have to + * do it in x86_64 case, but we can safely assume that + * x86_64 users won't actually flip this flag. + */ + vec &= ~((IA32CAP)(1<<1|1<<11|1<<25|1<<28) << 32); + } + } else if (env[0] == ':') { + vec = OPENSSL_ia32_cpuid(OPENSSL_ia32cap_P); + } + + if ((env = ossl_strchr(env, ':')) != NULL) { + IA32CAP vecx; + + env++; + off = (env[0] == '~') ? 1 : 0; + vecx = ossl_strtouint64(env + off); + if (off) { + OPENSSL_ia32cap_P[2] &= ~(unsigned int)vecx; + OPENSSL_ia32cap_P[3] &= ~(unsigned int)(vecx >> 32); + } else { + OPENSSL_ia32cap_P[2] = (unsigned int)vecx; + OPENSSL_ia32cap_P[3] = (unsigned int)(vecx >> 32); + } + } else { + OPENSSL_ia32cap_P[2] = 0; + OPENSSL_ia32cap_P[3] = 0; + } + } else { + vec = OPENSSL_ia32_cpuid(OPENSSL_ia32cap_P); + } + + /* + * |(1<<10) sets a reserved bit to signal that variable + * was initialized already... This is to avoid interference + * with cpuid snippets in ELF .init segment. + */ + OPENSSL_ia32cap_P[0] = (unsigned int)vec | (1 << 10); + OPENSSL_ia32cap_P[1] = (unsigned int)(vec >> 32); +} +# else +unsigned int OPENSSL_ia32cap_P[4]; +# endif +#endif + +#ifndef OPENSSL_CPUID_OBJ +# ifndef OPENSSL_CPUID_SETUP +void OPENSSL_cpuid_setup(void) +{ +} +# endif + +/* + * The rest are functions that are defined in the same assembler files as + * the CPUID functionality. + */ + +/* + * The volatile is used to to ensure that the compiler generates code that reads + * all values from the array and doesn't try to optimize this away. The standard + * doesn't actually require this behavior if the original data pointed to is + * not volatile, but compilers do this in practice anyway. + * + * There are also assembler versions of this function. + */ +# undef CRYPTO_memcmp +int CRYPTO_memcmp(const void * in_a, const void * in_b, size_t len) +{ + size_t i; + const volatile unsigned char *a = in_a; + const volatile unsigned char *b = in_b; + unsigned char x = 0; + + for (i = 0; i < len; i++) + x |= a[i] ^ b[i]; + + return x; +} + +/* + * For systems that don't provide an instruction counter register or equivalent. + */ +uint32_t OPENSSL_rdtsc(void) +{ + return 0; +} + +size_t OPENSSL_instrument_bus(unsigned int *out, size_t cnt) +{ + return 0; +} + +size_t OPENSSL_instrument_bus2(unsigned int *out, size_t cnt, size_t max) +{ + return 0; +} +#endif |