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