diff options
Diffstat (limited to 'third_party/boringssl/src/crypto/cpu-arm.c')
| -rw-r--r-- | third_party/boringssl/src/crypto/cpu-arm.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/third_party/boringssl/src/crypto/cpu-arm.c b/third_party/boringssl/src/crypto/cpu-arm.c new file mode 100644 index 0000000000..6e037ab946 --- /dev/null +++ b/third_party/boringssl/src/crypto/cpu-arm.c @@ -0,0 +1,189 @@ +/* Copyright (c) 2014, Google Inc. + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY + * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION + * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN + * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ + +#include <openssl/cpu.h> + +#if defined(OPENSSL_ARM) || defined(OPENSSL_AARCH64) + +#include <inttypes.h> +#include <string.h> + +#if !defined(OPENSSL_TRUSTY) +#include <setjmp.h> +#include <signal.h> +#endif + +#include <openssl/arm_arch.h> + + +/* We can't include <sys/auxv.h> because the Android SDK version against which + * Chromium builds is too old to have it. Instead we define all the constants + * that we need and have a weak pointer to getauxval. */ + +unsigned long getauxval(unsigned long type) __attribute__((weak)); + +char CRYPTO_is_NEON_capable(void) { + return (OPENSSL_armcap_P & ARMV7_NEON) != 0; +} + +static char g_set_neon_called = 0; + +void CRYPTO_set_NEON_capable(char neon_capable) { + g_set_neon_called = 1; + + if (neon_capable) { + OPENSSL_armcap_P |= ARMV7_NEON; + } else { + OPENSSL_armcap_P &= ~ARMV7_NEON; + } +} + +char CRYPTO_is_NEON_functional(void) { + static const uint32_t kWantFlags = ARMV7_NEON | ARMV7_NEON_FUNCTIONAL; + return (OPENSSL_armcap_P & kWantFlags) == kWantFlags; +} + +void CRYPTO_set_NEON_functional(char neon_functional) { + if (neon_functional) { + OPENSSL_armcap_P |= ARMV7_NEON_FUNCTIONAL; + } else { + OPENSSL_armcap_P &= ~ARMV7_NEON_FUNCTIONAL; + } +} + +#if !defined(OPENSSL_NO_ASM) && defined(OPENSSL_ARM) && !defined(OPENSSL_TRUSTY) + +static sigjmp_buf sigill_jmp; + +static void sigill_handler(int signal) { + siglongjmp(sigill_jmp, signal); +} + +void CRYPTO_arm_neon_probe(void); + +// probe_for_NEON returns 1 if a NEON instruction runs successfully. Because +// getauxval doesn't exist on Android until Jelly Bean, supporting NEON on +// older devices requires this. +static int probe_for_NEON(void) { + int supported = 0; + + sigset_t sigmask; + sigfillset(&sigmask); + sigdelset(&sigmask, SIGILL); + sigdelset(&sigmask, SIGTRAP); + sigdelset(&sigmask, SIGFPE); + sigdelset(&sigmask, SIGBUS); + sigdelset(&sigmask, SIGSEGV); + + struct sigaction sigill_original_action, sigill_action; + memset(&sigill_action, 0, sizeof(sigill_action)); + sigill_action.sa_handler = sigill_handler; + sigill_action.sa_mask = sigmask; + + sigset_t original_sigmask; + sigprocmask(SIG_SETMASK, &sigmask, &original_sigmask); + + if (sigsetjmp(sigill_jmp, 1 /* save signals */) == 0) { + sigaction(SIGILL, &sigill_action, &sigill_original_action); + + // This function cannot be inline asm because GCC will refuse to compile + // inline NEON instructions unless building with -mfpu=neon, which would + // defeat the point of probing for support at runtime. + CRYPTO_arm_neon_probe(); + supported = 1; + } + // Note that Android up to and including Lollipop doesn't restore the signal + // mask correctly after returning from a sigsetjmp. So that would need to be + // set again here if more probes were added. + // See https://android-review.googlesource.com/#/c/127624/ + + sigaction(SIGILL, &sigill_original_action, NULL); + sigprocmask(SIG_SETMASK, &original_sigmask, NULL); + + return supported; +} + +#else + +static int probe_for_NEON(void) { + return 0; +} + +#endif /* !OPENSSL_NO_ASM && OPENSSL_ARM && !OPENSSL_TRUSTY */ + +void OPENSSL_cpuid_setup(void) { + if (getauxval == NULL) { + // On ARM, but not AArch64, try a NEON instruction and see whether it works + // in order to probe for NEON support. + // + // Note that |CRYPTO_is_NEON_capable| can be true even if + // |CRYPTO_set_NEON_capable| has never been called if the code was compiled + // with NEON support enabled (e.g. -mfpu=neon). + if (!g_set_neon_called && !CRYPTO_is_NEON_capable() && probe_for_NEON()) { + OPENSSL_armcap_P |= ARMV7_NEON; + } + return; + } + + static const unsigned long AT_HWCAP = 16; + unsigned long hwcap = getauxval(AT_HWCAP); + +#if defined(OPENSSL_ARM) + static const unsigned long kNEON = 1 << 12; + if ((hwcap & kNEON) == 0) { + return; + } + + /* In 32-bit mode, the ARMv8 feature bits are in a different aux vector + * value. */ + static const unsigned long AT_HWCAP2 = 26; + hwcap = getauxval(AT_HWCAP2); + + /* See /usr/include/asm/hwcap.h on an ARM installation for the source of + * these values. */ + static const unsigned long kAES = 1 << 0; + static const unsigned long kPMULL = 1 << 1; + static const unsigned long kSHA1 = 1 << 2; + static const unsigned long kSHA256 = 1 << 3; +#elif defined(OPENSSL_AARCH64) + /* See /usr/include/asm/hwcap.h on an aarch64 installation for the source of + * these values. */ + static const unsigned long kNEON = 1 << 1; + static const unsigned long kAES = 1 << 3; + static const unsigned long kPMULL = 1 << 4; + static const unsigned long kSHA1 = 1 << 5; + static const unsigned long kSHA256 = 1 << 6; + + if ((hwcap & kNEON) == 0) { + return; + } +#endif + + OPENSSL_armcap_P |= ARMV7_NEON; + + if (hwcap & kAES) { + OPENSSL_armcap_P |= ARMV8_AES; + } + if (hwcap & kPMULL) { + OPENSSL_armcap_P |= ARMV8_PMULL; + } + if (hwcap & kSHA1) { + OPENSSL_armcap_P |= ARMV8_SHA1; + } + if (hwcap & kSHA256) { + OPENSSL_armcap_P |= ARMV8_SHA256; + } +} + +#endif /* defined(OPENSSL_ARM) || defined(OPENSSL_AARCH64) */ |