crypto/armcap.c

   1 /*
   2  * Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (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 # if defined(__GLIBC__) && defined(__GLIBC_PREREQ)
  67 #  if __GLIBC_PREREQ(2, 16)
  68 #   include <sys/auxv.h>
  69 #   define OSSL_IMPLEMENT_GETAUXVAL
  70 #  endif
  71 # endif
  72
  73 /*
  74  * ARM puts the feature bits for Crypto Extensions in AT_HWCAP2, whereas
  75  * AArch64 used AT_HWCAP.
  76  */
  77 # if defined(__arm__) || defined (__arm)
  78 #  define HWCAP                  16
  79                                   /* AT_HWCAP */
  80 #  define HWCAP_NEON             (1 << 12)
  81
  82 #  define HWCAP_CE               26
  83                                   /* AT_HWCAP2 */
  84 #  define HWCAP_CE_AES           (1 << 0)
  85 #  define HWCAP_CE_PMULL         (1 << 1)
  86 #  define HWCAP_CE_SHA1          (1 << 2)
  87 #  define HWCAP_CE_SHA256        (1 << 3)
  88 # elif defined(__aarch64__)
  89 #  define HWCAP                  16
  90                                   /* AT_HWCAP */
  91 #  define HWCAP_NEON             (1 << 1)
  92
  93 #  define HWCAP_CE               HWCAP
  94 #  define HWCAP_CE_AES           (1 << 3)
  95 #  define HWCAP_CE_PMULL         (1 << 4)
  96 #  define HWCAP_CE_SHA1          (1 << 5)
  97 #  define HWCAP_CE_SHA256        (1 << 6)
  98 #  define HWCAP_CE_SHA512        (1 << 21)
  99 # endif
 100
 101 void OPENSSL_cpuid_setup(void)
 102 {
 103     const char *e;
 104     struct sigaction ill_oact, ill_act;
 105     sigset_t oset;
 106     static int trigger = 0;
 107
 108     if (trigger)
 109         return;
 110     trigger = 1;
 111
 112     if ((e = getenv("OPENSSL_armcap"))) {
 113         OPENSSL_armcap_P = (unsigned int)strtoul(e, NULL, 0);
 114         return;
 115     }
 116
 117 # if defined(__APPLE__) && !defined(__aarch64__)
 118     /*
 119      * Capability probing by catching SIGILL appears to be problematic
 120      * on iOS. But since Apple universe is "monocultural", it's actually
 121      * possible to simply set pre-defined processor capability mask.
 122      */
 123     if (1) {
 124         OPENSSL_armcap_P = ARMV7_NEON;
 125         return;
 126     }
 127     /*
 128      * One could do same even for __aarch64__ iOS builds. It's not done
 129      * exclusively for reasons of keeping code unified across platforms.
 130      * Unified code works because it never triggers SIGILL on Apple
 131      * devices...
 132      */
 133 # endif
 134
 135     OPENSSL_armcap_P = 0;
 136
 137 # ifdef OSSL_IMPLEMENT_GETAUXVAL
 138     if (getauxval(HWCAP) & HWCAP_NEON) {
 139         unsigned long hwcap = getauxval(HWCAP_CE);
 140
 141         OPENSSL_armcap_P |= ARMV7_NEON;
 142
 143         if (hwcap & HWCAP_CE_AES)
 144             OPENSSL_armcap_P |= ARMV8_AES;
 145
 146         if (hwcap & HWCAP_CE_PMULL)
 147             OPENSSL_armcap_P |= ARMV8_PMULL;
 148
 149         if (hwcap & HWCAP_CE_SHA1)
 150             OPENSSL_armcap_P |= ARMV8_SHA1;
 151
 152         if (hwcap & HWCAP_CE_SHA256)
 153             OPENSSL_armcap_P |= ARMV8_SHA256;
 154
 155 #  ifdef __aarch64__
 156         if (hwcap & HWCAP_CE_SHA512)
 157             OPENSSL_armcap_P |= ARMV8_SHA512;
 158 #  endif
 159     }
 160 # endif
 161
 162     sigfillset(&all_masked);
 163     sigdelset(&all_masked, SIGILL);
 164     sigdelset(&all_masked, SIGTRAP);
 165     sigdelset(&all_masked, SIGFPE);
 166     sigdelset(&all_masked, SIGBUS);
 167     sigdelset(&all_masked, SIGSEGV);
 168
 169     memset(&ill_act, 0, sizeof(ill_act));
 170     ill_act.sa_handler = ill_handler;
 171     ill_act.sa_mask = all_masked;
 172
 173     sigprocmask(SIG_SETMASK, &ill_act.sa_mask, &oset);
 174     sigaction(SIGILL, &ill_act, &ill_oact);
 175
 176     /* If we used getauxval, we already have all the values */
 177 # ifndef OSSL_IMPLEMENT_GETAUXVAL
 178     if (sigsetjmp(ill_jmp, 1) == 0) {
 179         _armv7_neon_probe();
 180         OPENSSL_armcap_P |= ARMV7_NEON;
 181         if (sigsetjmp(ill_jmp, 1) == 0) {
 182             _armv8_pmull_probe();
 183             OPENSSL_armcap_P |= ARMV8_PMULL | ARMV8_AES;
 184         } else if (sigsetjmp(ill_jmp, 1) == 0) {
 185             _armv8_aes_probe();
 186             OPENSSL_armcap_P |= ARMV8_AES;
 187         }
 188         if (sigsetjmp(ill_jmp, 1) == 0) {
 189             _armv8_sha1_probe();
 190             OPENSSL_armcap_P |= ARMV8_SHA1;
 191         }
 192         if (sigsetjmp(ill_jmp, 1) == 0) {
 193             _armv8_sha256_probe();
 194             OPENSSL_armcap_P |= ARMV8_SHA256;
 195         }
 196 #  if defined(__aarch64__) && !defined(__APPLE__)
 197         if (sigsetjmp(ill_jmp, 1) == 0) {
 198             _armv8_sha512_probe();
 199             OPENSSL_armcap_P |= ARMV8_SHA512;
 200         }
 201 #  endif
 202     }
 203 # endif
 204
 205     /* Things that getauxval didn't tell us */
 206     if (sigsetjmp(ill_jmp, 1) == 0) {
 207         _armv7_tick();
 208         OPENSSL_armcap_P |= ARMV7_TICK;
 209     }
 210
 211     sigaction(SIGILL, &ill_oact, NULL);
 212     sigprocmask(SIG_SETMASK, &oset, NULL);
 213 }
 214 #endif