crypto/armcap.c

   1 /*
   2  * Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include <setjmp.h>
  14 #include <signal.h>
  15 #include <openssl/crypto.h>
  16 #include "internal/cryptlib.h"
  17
  18 #include "arm_arch.h"
  19
  20 unsigned int OPENSSL_armcap_P = 0;
  21
  22 #if __ARM_MAX_ARCH__<7
  23 void OPENSSL_cpuid_setup(void)
  24 {
  25 }
  26
  27 uint32_t OPENSSL_rdtsc(void)
  28 {
  29     return 0;
  30 }
  31 #else
  32 static sigset_t all_masked;
  33
  34 static sigjmp_buf ill_jmp;
  35 static void ill_handler(int sig)
  36 {
  37     siglongjmp(ill_jmp, sig);
  38 }
  39
  40 /*
  41  * Following subroutines could have been inlined, but it's not all
  42  * ARM compilers support inline assembler...
  43  */
  44 void _armv7_neon_probe(void);
  45 void _armv8_aes_probe(void);
  46 void _armv8_sha1_probe(void);
  47 void _armv8_sha256_probe(void);
  48 void _armv8_pmull_probe(void);
  49 # ifdef __aarch64__
  50 void _armv8_sha512_probe(void);
  51 # endif
  52 uint32_t _armv7_tick(void);
  53
  54 uint32_t OPENSSL_rdtsc(void)
  55 {
  56     if (OPENSSL_armcap_P & ARMV7_TICK)
  57         return _armv7_tick();
  58     else
  59         return 0;
  60 }
  61
  62 # if defined(__GNUC__) && __GNUC__>=2
  63 void OPENSSL_cpuid_setup(void) __attribute__ ((constructor));
  64 # endif
  65 /*
  66  * Use a weak reference to getauxval() so we can use it if it is available but
  67  * don't break the build if it is not.
  68  */
  69 # if defined(__GNUC__) && __GNUC__>=2 && defined(__ELF__)
  70 extern unsigned long getauxval(unsigned long type) __attribute__ ((weak));
  71 # else
  72 static unsigned long (*getauxval) (unsigned long) = NULL;
  73 # endif
  74
  75 /*
  76  * ARM puts the feature bits for Crypto Extensions in AT_HWCAP2, whereas
  77  * AArch64 used AT_HWCAP.
  78  */
  79 # if defined(__arm__) || defined (__arm)
  80 #  define HWCAP                  16
  81                                   /* AT_HWCAP */
  82 #  define HWCAP_NEON             (1 << 12)
  83
  84 #  define HWCAP_CE               26
  85                                   /* AT_HWCAP2 */
  86 #  define HWCAP_CE_AES           (1 << 0)
  87 #  define HWCAP_CE_PMULL         (1 << 1)
  88 #  define HWCAP_CE_SHA1          (1 << 2)
  89 #  define HWCAP_CE_SHA256        (1 << 3)
  90 # elif defined(__aarch64__)
  91 #  define HWCAP                  16
  92                                   /* AT_HWCAP */
  93 #  define HWCAP_NEON             (1 << 1)
  94
  95 #  define HWCAP_CE               HWCAP
  96 #  define HWCAP_CE_AES           (1 << 3)
  97 #  define HWCAP_CE_PMULL         (1 << 4)
  98 #  define HWCAP_CE_SHA1          (1 << 5)
  99 #  define HWCAP_CE_SHA256        (1 << 6)
 100 #  define HWCAP_CE_SHA512        (1 << 21)
 101 # endif
 102
 103 void OPENSSL_cpuid_setup(void)
 104 {
 105     const char *e;
 106     struct sigaction ill_oact, ill_act;
 107     sigset_t oset;
 108     static int trigger = 0;
 109
 110     if (trigger)
 111         return;
 112     trigger = 1;
 113
 114     if ((e = getenv("OPENSSL_armcap"))) {
 115         OPENSSL_armcap_P = (unsigned int)strtoul(e, NULL, 0);
 116         return;
 117     }
 118
 119 # if defined(__APPLE__) && !defined(__aarch64__)
 120     /*
 121      * Capability probing by catching SIGILL appears to be problematic
 122      * on iOS. But since Apple universe is "monocultural", it's actually
 123      * possible to simply set pre-defined processor capability mask.
 124      */
 125     if (1) {
 126         OPENSSL_armcap_P = ARMV7_NEON;
 127         return;
 128     }
 129     /*
 130      * One could do same even for __aarch64__ iOS builds. It's not done
 131      * exclusively for reasons of keeping code unified across platforms.
 132      * Unified code works because it never triggers SIGILL on Apple
 133      * devices...
 134      */
 135 # endif
 136
 137     sigfillset(&all_masked);
 138     sigdelset(&all_masked, SIGILL);
 139     sigdelset(&all_masked, SIGTRAP);
 140     sigdelset(&all_masked, SIGFPE);
 141     sigdelset(&all_masked, SIGBUS);
 142     sigdelset(&all_masked, SIGSEGV);
 143
 144     OPENSSL_armcap_P = 0;
 145
 146     memset(&ill_act, 0, sizeof(ill_act));
 147     ill_act.sa_handler = ill_handler;
 148     ill_act.sa_mask = all_masked;
 149
 150     sigprocmask(SIG_SETMASK, &ill_act.sa_mask, &oset);
 151     sigaction(SIGILL, &ill_act, &ill_oact);
 152
 153     if (getauxval != NULL) {
 154         if (getauxval(HWCAP) & HWCAP_NEON) {
 155             unsigned long hwcap = getauxval(HWCAP_CE);
 156
 157             OPENSSL_armcap_P |= ARMV7_NEON;
 158
 159             if (hwcap & HWCAP_CE_AES)
 160                 OPENSSL_armcap_P |= ARMV8_AES;
 161
 162             if (hwcap & HWCAP_CE_PMULL)
 163                 OPENSSL_armcap_P |= ARMV8_PMULL;
 164
 165             if (hwcap & HWCAP_CE_SHA1)
 166                 OPENSSL_armcap_P |= ARMV8_SHA1;
 167
 168             if (hwcap & HWCAP_CE_SHA256)
 169                 OPENSSL_armcap_P |= ARMV8_SHA256;
 170
 171 # ifdef __aarch64__
 172             if (hwcap & HWCAP_CE_SHA512)
 173                 OPENSSL_armcap_P |= ARMV8_SHA512;
 174 # endif
 175         }
 176     } else if (sigsetjmp(ill_jmp, 1) == 0) {
 177         _armv7_neon_probe();
 178         OPENSSL_armcap_P |= ARMV7_NEON;
 179         if (sigsetjmp(ill_jmp, 1) == 0) {
 180             _armv8_pmull_probe();
 181             OPENSSL_armcap_P |= ARMV8_PMULL | ARMV8_AES;
 182         } else if (sigsetjmp(ill_jmp, 1) == 0) {
 183             _armv8_aes_probe();
 184             OPENSSL_armcap_P |= ARMV8_AES;
 185         }
 186         if (sigsetjmp(ill_jmp, 1) == 0) {
 187             _armv8_sha1_probe();
 188             OPENSSL_armcap_P |= ARMV8_SHA1;
 189         }
 190         if (sigsetjmp(ill_jmp, 1) == 0) {
 191             _armv8_sha256_probe();
 192             OPENSSL_armcap_P |= ARMV8_SHA256;
 193         }
 194 # ifdef __aarch64__
 195         if (sigsetjmp(ill_jmp, 1) == 0) {
 196             _armv8_sha512_probe();
 197             OPENSSL_armcap_P |= ARMV8_SHA512;
 198         }
 199 # endif
 200     }
 201     if (sigsetjmp(ill_jmp, 1) == 0) {
 202         _armv7_tick();
 203         OPENSSL_armcap_P |= ARMV7_TICK;
 204     }
 205
 206     sigaction(SIGILL, &ill_oact, NULL);
 207     sigprocmask(SIG_SETMASK, &oset, NULL);
 208 }
 209 #endif