From: Andy Polyakov Date: Fri, 17 Jun 2016 14:09:38 +0000 (+0200) Subject: crypto/cryptlib.c: omit OPENSSL_ia32cap_loc(). X-Git-Tag: OpenSSL_1_1_0-pre6~367 X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff_plain;h=eeac54ef6d7eedd42a97025ddddaf06777be3c6b;hp=f430ba31ac81f27f0014320fee335d2dc4562a95 crypto/cryptlib.c: omit OPENSSL_ia32cap_loc(). Reviewed-by: Rich Salz --- diff --git a/crypto/cryptlib.c b/crypto/cryptlib.c index 8e189eca64..01b8ce5ed1 100644 --- a/crypto/cryptlib.c +++ b/crypto/cryptlib.c @@ -21,10 +21,6 @@ defined(_M_AMD64) || defined(_M_X64) extern unsigned int OPENSSL_ia32cap_P[4]; -unsigned int *OPENSSL_ia32cap_loc(void) -{ - return OPENSSL_ia32cap_P; -} # if defined(OPENSSL_CPUID_OBJ) && !defined(OPENSSL_NO_ASM) && !defined(I386_ONLY) #include @@ -80,12 +76,6 @@ void OPENSSL_cpuid_setup(void) # else unsigned int OPENSSL_ia32cap_P[4]; # endif - -#else -unsigned int *OPENSSL_ia32cap_loc(void) -{ - return NULL; -} #endif int OPENSSL_NONPIC_relocated = 0; #if !defined(OPENSSL_CPUID_SETUP) && !defined(OPENSSL_CPUID_OBJ) diff --git a/doc/crypto/OPENSSL_ia32cap.pod b/doc/crypto/OPENSSL_ia32cap.pod index 33c25f4b64..e062e287f4 100644 --- a/doc/crypto/OPENSSL_ia32cap.pod +++ b/doc/crypto/OPENSSL_ia32cap.pod @@ -2,23 +2,22 @@ =head1 NAME -OPENSSL_ia32cap, OPENSSL_ia32cap_loc - the IA-32 processor capabilities vector +OPENSSL_ia32cap - the x86[_64] processor capabilities vector =head1 SYNOPSIS - unsigned int *OPENSSL_ia32cap_loc(void); - #define OPENSSL_ia32cap ((OPENSSL_ia32cap_loc())[0]) + env OPENSSL_ia32cap=... =head1 DESCRIPTION -Value returned by OPENSSL_ia32cap_loc() is address of a variable -containing IA-32 processor capabilities bit vector as it appears in -EDX:ECX register pair after executing CPUID instruction with EAX=1 -input value (see Intel Application Note #241618). Naturally it's -meaningful on x86 and x86_64 platforms only. The variable is normally -set up automatically upon toolkit initialization, but can be -manipulated afterwards to modify crypto library behaviour. For the -moment of this writing following bits are significant: +OpenSSL supports a range of x86[_64] instruction set extensions. These +extensions are denoted by individual bits in capability vector returned +by processor in EDX:ECX register pair after executing CPUID instruction +with EAX=1 input value (see Intel Application Note #241618). This vector +is copied to memory upon toolkit initialization and used to choose +between different code paths to provide optimal performance across wide +range of processors. For the moment of this writing following bits are +significant: =over @@ -67,21 +66,22 @@ disables high-performance SSE2 code present in the crypto library, while clearing bit #24 disables SSE2 code operating on 128-bit XMM register bank. You might have to do the latter if target OpenSSL application is executed on SSE2 capable CPU, but under control of OS that does not -enable XMM registers. Even though you can manipulate the value -programmatically, you most likely will find it more appropriate to set -up an environment variable with the same name prior starting target -application, e.g. on Intel P4 processor 'env OPENSSL_ia32cap=0x16980010 -apps/openssl', or better yet 'env OPENSSL_ia32cap=~0x1000000 -apps/openssl' to achieve same effect without modifying the application -source code. Alternatively you can reconfigure the toolkit with no-sse2 +enable XMM registers. Historically address of the capability vector copy +was exposed to application through OPENSSL_ia32cap_loc(), but not +anymore. Now the only way to affect the capability detection is to set +OPENSSL_ia32cap envrionment variable prior target application start. To +give a specific example, on Intel P4 processor 'env +OPENSSL_ia32cap=0x16980010 apps/openssl', or better yet 'env +OPENSSL_ia32cap=~0x1000000 apps/openssl' would achieve the desired +effect. Alternatively you can reconfigure the toolkit with no-sse2 option and recompile. -Less intuitive is clearing bit #28. The truth is that it's not copied -from CPUID output verbatim, but is adjusted to reflect whether or not -the data cache is actually shared between logical cores. This in turn -affects the decision on whether or not expensive countermeasures -against cache-timing attacks are applied, most notably in AES assembler -module. +Less intuitive is clearing bit #28, or ~0x10000000 in the "environment +variable" terms. The truth is that it's not copied from CPUID output +verbatim, but is adjusted to reflect whether or not the data cache is +actually shared between logical cores. This in turn affects the decision +on whether or not expensive countermeasures against cache-timing attacks +are applied, most notably in AES assembler module. The capability vector is further extended with EBX value returned by CPUID with EAX=7 and ECX=0 as input. Following bits are significant: diff --git a/include/openssl/crypto.h b/include/openssl/crypto.h index 0f593498db..2e056c5bce 100644 --- a/include/openssl/crypto.h +++ b/include/openssl/crypto.h @@ -317,8 +317,6 @@ ossl_noreturn void OPENSSL_die(const char *assertion, const char *file, int line # define OPENSSL_assert(e) \ (void)((e) ? 0 : (OPENSSL_die("assertion failed: " #e, OPENSSL_FILE, OPENSSL_LINE), 1)) -unsigned int *OPENSSL_ia32cap_loc(void); -# define OPENSSL_ia32cap ((OPENSSL_ia32cap_loc())[0]) int OPENSSL_isservice(void); int FIPS_mode(void); diff --git a/test/sha512t.c b/test/sha512t.c index e741b27fdb..b11fcaa051 100644 --- a/test/sha512t.c +++ b/test/sha512t.c @@ -81,19 +81,6 @@ int main(int argc, char **argv) int i; EVP_MD_CTX *evp; -# ifdef OPENSSL_IA32_SSE2 - /* - * Alternative to this is to call OpenSSL_add_all_algorithms... The below - * code is retained exclusively for debugging purposes. - */ - { - char *env; - - if ((env = getenv("OPENSSL_ia32cap"))) - OPENSSL_ia32cap = strtoul(env, NULL, 0); - } -# endif - fprintf(stdout, "Testing SHA-512 "); EVP_Digest("abc", 3, md, NULL, EVP_sha512(), NULL); diff --git a/test/wp_test.c b/test/wp_test.c index 40859bae29..7b5cc04a16 100644 --- a/test/wp_test.c +++ b/test/wp_test.c @@ -128,19 +128,6 @@ int main(int argc, char *argv[]) int i; WHIRLPOOL_CTX ctx; -# ifdef OPENSSL_IA32_SSE2 - /* - * Alternative to this is to call OpenSSL_add_all_algorithms... The below - * code is retained exclusively for debugging purposes. - */ - { - char *env; - - if ((env = getenv("OPENSSL_ia32cap"))) - OPENSSL_ia32cap = strtoul(env, NULL, 0); - } -# endif - fprintf(stdout, "Testing Whirlpool "); WHIRLPOOL("", 0, md); diff --git a/util/libcrypto.num b/util/libcrypto.num index 408677ca2f..fa07ecfef9 100644 --- a/util/libcrypto.num +++ b/util/libcrypto.num @@ -2841,7 +2841,6 @@ d2i_ASN1_T61STRING 2793 1_1_0 EXIST::FUNCTION: DES_pcbc_encrypt 2794 1_1_0 EXIST::FUNCTION:DES EVP_PKEY_print_params 2795 1_1_0 EXIST::FUNCTION: BN_get0_nist_prime_192 2796 1_1_0 EXIST::FUNCTION: -OPENSSL_ia32cap_loc 2797 1_1_0 EXIST::FUNCTION: EVP_SealInit 2798 1_1_0 EXIST::FUNCTION:RSA X509_REQ_get0_signature 2799 1_1_0 EXIST::FUNCTION: PKEY_USAGE_PERIOD_free 2800 1_1_0 EXIST::FUNCTION: