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 unsigned long 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 unsigned long _armv7_tick(void);
  50
  51 unsigned long OPENSSL_rdtsc(void)
  52 {
  53     if (OPENSSL_armcap_P & ARMV7_TICK)
  54         return _armv7_tick();
  55     else
  56         return 0;
  57 }
  58
  59 # if defined(__GNUC__) && __GNUC__>=2
  60 void OPENSSL_cpuid_setup(void) __attribute__ ((constructor));
  61 # endif
  62 /*
  63  * Use a weak reference to getauxval() so we can use it if it is available but
  64  * don't break the build if it is not.
  65  */
  66 # if defined(__GNUC__) && __GNUC__>=2 && defined(__ELF__)
  67 extern unsigned long getauxval(unsigned long type) __attribute__ ((weak));
  68 # else
  69 static unsigned long (*getauxval) (unsigned long) = NULL;
  70 # endif
  71
  72 /*
  73  * ARM puts the feature bits for Crypto Extensions in AT_HWCAP2, whereas
  74  * AArch64 used AT_HWCAP.
  75  */
  76 # if defined(__arm__) || defined (__arm)
  77 #  define HWCAP                  16
  78                                   /* AT_HWCAP */
  79 #  define HWCAP_NEON             (1 << 12)
  80
  81 #  define HWCAP_CE               26
  82                                   /* AT_HWCAP2 */
  83 #  define HWCAP_CE_AES           (1 << 0)
  84 #  define HWCAP_CE_PMULL         (1 << 1)
  85 #  define HWCAP_CE_SHA1          (1 << 2)
  86 #  define HWCAP_CE_SHA256        (1 << 3)
  87 # elif defined(__aarch64__)
  88 #  define HWCAP                  16
  89                                   /* AT_HWCAP */
  90 #  define HWCAP_NEON             (1 << 1)
  91
  92 #  define HWCAP_CE               HWCAP
  93 #  define HWCAP_CE_AES           (1 << 3)
  94 #  define HWCAP_CE_PMULL         (1 << 4)
  95 #  define HWCAP_CE_SHA1          (1 << 5)
  96 #  define HWCAP_CE_SHA256        (1 << 6)
  97 # endif
  98
  99 void OPENSSL_cpuid_setup(void)
 100 {
 101     char *e;
 102     struct sigaction ill_oact, ill_act;
 103     sigset_t oset;
 104     static int trigger = 0;
 105
 106     if (trigger)
 107         return;
 108     trigger = 1;
 109
 110     if ((e = getenv("OPENSSL_armcap"))) {
 111         OPENSSL_armcap_P = (unsigned int)strtoul(e, NULL, 0);
 112         return;
 113     }
 114
 115 # if defined(__APPLE__) && !defined(__aarch64__)
 116     /*
 117      * Capability probing by catching SIGILL appears to be problematic
 118      * on iOS. But since Apple universe is "monocultural", it's actually
 119      * possible to simply set pre-defined processor capability mask.
 120      */
 121     if (1) {
 122         OPENSSL_armcap_P = ARMV7_NEON;
 123         return;
 124     }
 125     /*
 126      * One could do same even for __aarch64__ iOS builds. It's not done
 127      * exclusively for reasons of keeping code unified across platforms.
 128      * Unified code works because it never triggers SIGILL on Apple
 129      * devices...
 130      */
 131 # endif
 132
 133     sigfillset(&all_masked);
 134     sigdelset(&all_masked, SIGILL);
 135     sigdelset(&all_masked, SIGTRAP);
 136     sigdelset(&all_masked, SIGFPE);
 137     sigdelset(&all_masked, SIGBUS);
 138     sigdelset(&all_masked, SIGSEGV);
 139
 140     OPENSSL_armcap_P = 0;
 141
 142     memset(&ill_act, 0, sizeof(ill_act));
 143     ill_act.sa_handler = ill_handler;
 144     ill_act.sa_mask = all_masked;
 145
 146     sigprocmask(SIG_SETMASK, &ill_act.sa_mask, &oset);
 147     sigaction(SIGILL, &ill_act, &ill_oact);
 148
 149     if (getauxval != NULL) {
 150         if (getauxval(HWCAP) & HWCAP_NEON) {
 151             unsigned long hwcap = getauxval(HWCAP_CE);
 152
 153             OPENSSL_armcap_P |= ARMV7_NEON;
 154
 155             if (hwcap & HWCAP_CE_AES)
 156                 OPENSSL_armcap_P |= ARMV8_AES;
 157
 158             if (hwcap & HWCAP_CE_PMULL)
 159                 OPENSSL_armcap_P |= ARMV8_PMULL;
 160
 161             if (hwcap & HWCAP_CE_SHA1)
 162                 OPENSSL_armcap_P |= ARMV8_SHA1;
 163
 164             if (hwcap & HWCAP_CE_SHA256)
 165                 OPENSSL_armcap_P |= ARMV8_SHA256;
 166         }
 167     } else if (sigsetjmp(ill_jmp, 1) == 0) {
 168         _armv7_neon_probe();
 169         OPENSSL_armcap_P |= ARMV7_NEON;
 170         if (sigsetjmp(ill_jmp, 1) == 0) {
 171             _armv8_pmull_probe();
 172             OPENSSL_armcap_P |= ARMV8_PMULL | ARMV8_AES;
 173         } else if (sigsetjmp(ill_jmp, 1) == 0) {
 174             _armv8_aes_probe();
 175             OPENSSL_armcap_P |= ARMV8_AES;
 176         }
 177         if (sigsetjmp(ill_jmp, 1) == 0) {
 178             _armv8_sha1_probe();
 179             OPENSSL_armcap_P |= ARMV8_SHA1;
 180         }
 181         if (sigsetjmp(ill_jmp, 1) == 0) {
 182             _armv8_sha256_probe();
 183             OPENSSL_armcap_P |= ARMV8_SHA256;
 184         }
 185     }
 186     if (sigsetjmp(ill_jmp, 1) == 0) {
 187         _armv7_tick();
 188         OPENSSL_armcap_P |= ARMV7_TICK;
 189     }
 190
 191     sigaction(SIGILL, &ill_oact, NULL);
 192     sigprocmask(SIG_SETMASK, &oset, NULL);
 193 }
 194 #endif