blob: 8ca60fbf26cc42d9600eafd59839826016fd216c [file] [log] [blame]
/* 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 <setjmp.h>
#include <signal.h>
#include <string.h>
#include "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));
static const unsigned long AT_HWCAP = 16;
static const unsigned long AT_HWCAP2 = 26;
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)
static sigjmp_buf sigill_jmp;
static void sigill_handler(int signal) {
siglongjmp(sigill_jmp, signal);
}
void CRYPTO_arm_neon_probe();
// 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() {
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);
sigaction(SIGILL, &sigill_action, &sigill_original_action);
if (sigsetjmp(sigill_jmp, 1 /* save signals */) == 0) {
// 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() {
return 0;
}
#endif /* !OPENSSL_NO_ASM && OPENSSL_ARM */
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;
}
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. */
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 | ARMV7_NEON_FUNCTIONAL;
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) */