crypto/armcap.c

   1 /*
   2  * Copyright 2011-2021 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 #ifdef __APPLE__
  17 #include <sys/sysctl.h>
  18 #endif
  19 #include "internal/cryptlib.h"
  20
  21 #include "arm_arch.h"
  22
  23 unsigned int OPENSSL_armcap_P = 0;
  24 unsigned int OPENSSL_arm_midr = 0;
  25 unsigned int OPENSSL_armv8_rsa_neonized = 0;
  26
  27 #if __ARM_MAX_ARCH__<7
  28 void OPENSSL_cpuid_setup(void)
  29 {
  30 }
  31
  32 uint32_t OPENSSL_rdtsc(void)
  33 {
  34     return 0;
  35 }
  36 #else
  37 static sigset_t all_masked;
  38
  39 static sigjmp_buf ill_jmp;
  40 static void ill_handler(int sig)
  41 {
  42     siglongjmp(ill_jmp, sig);
  43 }
  44
  45 /*
  46  * Following subroutines could have been inlined, but it's not all
  47  * ARM compilers support inline assembler...
  48  */
  49 void _armv7_neon_probe(void);
  50 void _armv8_aes_probe(void);
  51 void _armv8_sha1_probe(void);
  52 void _armv8_sha256_probe(void);
  53 void _armv8_pmull_probe(void);
  54 # ifdef __aarch64__
  55 void _armv8_sha512_probe(void);
  56 unsigned int _armv8_cpuid_probe(void);
  57 # endif
  58 uint32_t _armv7_tick(void);
  59
  60 uint32_t OPENSSL_rdtsc(void)
  61 {
  62     if (OPENSSL_armcap_P & ARMV7_TICK)
  63         return _armv7_tick();
  64     else
  65         return 0;
  66 }
  67
  68 # if defined(__GNUC__) && __GNUC__>=2
  69 void OPENSSL_cpuid_setup(void) __attribute__ ((constructor));
  70 # endif
  71
  72 # if defined(__GLIBC__) && defined(__GLIBC_PREREQ)
  73 #  if __GLIBC_PREREQ(2, 16)
  74 #   include <sys/auxv.h>
  75 #   define OSSL_IMPLEMENT_GETAUXVAL
  76 #  endif
  77 # endif
  78 # if defined(__FreeBSD__)
  79 #  include <sys/param.h>
  80 #  if __FreeBSD_version >= 1200000
  81 #   include <sys/auxv.h>
  82 #   define OSSL_IMPLEMENT_GETAUXVAL
  83
  84 static unsigned long getauxval(unsigned long key)
  85 {
  86   unsigned long val = 0ul;
  87
  88   if (elf_aux_info((int)key, &val, sizeof(val)) != 0)
  89     return 0ul;
  90
  91   return val;
  92 }
  93 #  endif
  94 # endif
  95
  96 /*
  97  * ARM puts the feature bits for Crypto Extensions in AT_HWCAP2, whereas
  98  * AArch64 used AT_HWCAP.
  99  */
 100 # if defined(__arm__) || defined (__arm)
 101 #  define HWCAP                  16
 102                                   /* AT_HWCAP */
 103 #  define HWCAP_NEON             (1 << 12)
 104
 105 #  define HWCAP_CE               26
 106                                   /* AT_HWCAP2 */
 107 #  define HWCAP_CE_AES           (1 << 0)
 108 #  define HWCAP_CE_PMULL         (1 << 1)
 109 #  define HWCAP_CE_SHA1          (1 << 2)
 110 #  define HWCAP_CE_SHA256        (1 << 3)
 111 # elif defined(__aarch64__)
 112 #  define HWCAP                  16
 113                                   /* AT_HWCAP */
 114 #  define HWCAP_NEON             (1 << 1)
 115
 116 #  define HWCAP_CE               HWCAP
 117 #  define HWCAP_CE_AES           (1 << 3)
 118 #  define HWCAP_CE_PMULL         (1 << 4)
 119 #  define HWCAP_CE_SHA1          (1 << 5)
 120 #  define HWCAP_CE_SHA256        (1 << 6)
 121 #  define HWCAP_CPUID            (1 << 11)
 122 #  define HWCAP_CE_SHA512        (1 << 21)
 123 # endif
 124
 125 void OPENSSL_cpuid_setup(void)
 126 {
 127     const char *e;
 128     struct sigaction ill_oact, ill_act;
 129     sigset_t oset;
 130     static int trigger = 0;
 131
 132     if (trigger)
 133         return;
 134     trigger = 1;
 135
 136     if ((e = getenv("OPENSSL_armcap"))) {
 137         OPENSSL_armcap_P = (unsigned int)strtoul(e, NULL, 0);
 138         return;
 139     }
 140
 141 # if defined(__APPLE__)
 142 #   if !defined(__aarch64__)
 143     /*
 144      * Capability probing by catching SIGILL appears to be problematic
 145      * on iOS. But since Apple universe is "monocultural", it's actually
 146      * possible to simply set pre-defined processor capability mask.
 147      */
 148     if (1) {
 149         OPENSSL_armcap_P = ARMV7_NEON;
 150         return;
 151     }
 152     /*
 153      * One could do same even for __aarch64__ iOS builds. It's not done
 154      * exclusively for reasons of keeping code unified across platforms.
 155      * Unified code works because it never triggers SIGILL on Apple
 156      * devices...
 157      */
 158 #   else
 159     {
 160         unsigned int sha512;
 161         size_t len = sizeof(sha512);
 162
 163         if (sysctlbyname("hw.optional.armv8_2_sha512", &sha512, &len, NULL, 0) == 0 && sha512 == 1)
 164             OPENSSL_armcap_P |= ARMV8_SHA512;
 165     }
 166 #   endif
 167 # endif
 168
 169     OPENSSL_armcap_P = 0;
 170
 171 # ifdef OSSL_IMPLEMENT_GETAUXVAL
 172     if (getauxval(HWCAP) & HWCAP_NEON) {
 173         unsigned long hwcap = getauxval(HWCAP_CE);
 174
 175         OPENSSL_armcap_P |= ARMV7_NEON;
 176
 177         if (hwcap & HWCAP_CE_AES)
 178             OPENSSL_armcap_P |= ARMV8_AES;
 179
 180         if (hwcap & HWCAP_CE_PMULL)
 181             OPENSSL_armcap_P |= ARMV8_PMULL;
 182
 183         if (hwcap & HWCAP_CE_SHA1)
 184             OPENSSL_armcap_P |= ARMV8_SHA1;
 185
 186         if (hwcap & HWCAP_CE_SHA256)
 187             OPENSSL_armcap_P |= ARMV8_SHA256;
 188
 189 #  ifdef __aarch64__
 190         if (hwcap & HWCAP_CE_SHA512)
 191             OPENSSL_armcap_P |= ARMV8_SHA512;
 192
 193         if (hwcap & HWCAP_CPUID)
 194             OPENSSL_armcap_P |= ARMV8_CPUID;
 195 #  endif
 196     }
 197 # endif
 198
 199     sigfillset(&all_masked);
 200     sigdelset(&all_masked, SIGILL);
 201     sigdelset(&all_masked, SIGTRAP);
 202     sigdelset(&all_masked, SIGFPE);
 203     sigdelset(&all_masked, SIGBUS);
 204     sigdelset(&all_masked, SIGSEGV);
 205
 206     memset(&ill_act, 0, sizeof(ill_act));
 207     ill_act.sa_handler = ill_handler;
 208     ill_act.sa_mask = all_masked;
 209
 210     sigprocmask(SIG_SETMASK, &ill_act.sa_mask, &oset);
 211     sigaction(SIGILL, &ill_act, &ill_oact);
 212
 213     /* If we used getauxval, we already have all the values */
 214 # ifndef OSSL_IMPLEMENT_GETAUXVAL
 215     if (sigsetjmp(ill_jmp, 1) == 0) {
 216         _armv7_neon_probe();
 217         OPENSSL_armcap_P |= ARMV7_NEON;
 218         if (sigsetjmp(ill_jmp, 1) == 0) {
 219             _armv8_pmull_probe();
 220             OPENSSL_armcap_P |= ARMV8_PMULL | ARMV8_AES;
 221         } else if (sigsetjmp(ill_jmp, 1) == 0) {
 222             _armv8_aes_probe();
 223             OPENSSL_armcap_P |= ARMV8_AES;
 224         }
 225         if (sigsetjmp(ill_jmp, 1) == 0) {
 226             _armv8_sha1_probe();
 227             OPENSSL_armcap_P |= ARMV8_SHA1;
 228         }
 229         if (sigsetjmp(ill_jmp, 1) == 0) {
 230             _armv8_sha256_probe();
 231             OPENSSL_armcap_P |= ARMV8_SHA256;
 232         }
 233 #  if defined(__aarch64__) && !defined(__APPLE__)
 234         if (sigsetjmp(ill_jmp, 1) == 0) {
 235             _armv8_sha512_probe();
 236             OPENSSL_armcap_P |= ARMV8_SHA512;
 237         }
 238 #  endif
 239     }
 240 # endif
 241
 242     /* Things that getauxval didn't tell us */
 243     if (sigsetjmp(ill_jmp, 1) == 0) {
 244         _armv7_tick();
 245         OPENSSL_armcap_P |= ARMV7_TICK;
 246     }
 247
 248     sigaction(SIGILL, &ill_oact, NULL);
 249     sigprocmask(SIG_SETMASK, &oset, NULL);
 250
 251 # ifdef __aarch64__
 252     if (OPENSSL_armcap_P & ARMV8_CPUID)
 253         OPENSSL_arm_midr = _armv8_cpuid_probe();
 254
 255     if ((MIDR_IS_CPU_MODEL(OPENSSL_arm_midr, ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A72) ||
 256          MIDR_IS_CPU_MODEL(OPENSSL_arm_midr, ARM_CPU_IMP_ARM, ARM_CPU_PART_N1)) &&
 257         (OPENSSL_armcap_P & ARMV7_NEON)) {
 258             OPENSSL_armv8_rsa_neonized = 1;
 259     }
 260 # endif
 261 }
 262 #endif