- /* 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 "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();
-
- // 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);
-
- 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) */
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