crypto/armcap.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <setjmp.h>
   5 #include <signal.h>
   6 #include <crypto.h>
   7
   8 #include "arm_arch.h"
   9
  10 unsigned int OPENSSL_armcap_P;
  11
  12 static sigset_t all_masked;
  13
  14 static sigjmp_buf ill_jmp;
  15 static void ill_handler(int sig)
  16 {
  17     siglongjmp(ill_jmp, sig);
  18 }
  19
  20 /*
  21  * Following subroutines could have been inlined, but it's not all
  22  * ARM compilers support inline assembler...
  23  */
  24 void _armv7_neon_probe(void);
  25 unsigned int _armv7_tick(void);
  26
  27 unsigned int OPENSSL_rdtsc(void)
  28 {
  29     if (OPENSSL_armcap_P & ARMV7_TICK)
  30         return _armv7_tick();
  31     else
  32         return 0;
  33 }
  34
  35 #if defined(__GNUC__) && __GNUC__>=2
  36 void OPENSSL_cpuid_setup(void) __attribute__ ((constructor));
  37 #endif
  38 void OPENSSL_cpuid_setup(void)
  39 {
  40     char *e;
  41     struct sigaction ill_oact, ill_act;
  42     sigset_t oset;
  43     static int trigger = 0;
  44
  45     if (trigger)
  46         return;
  47     trigger = 1;
  48
  49     if ((e = getenv("OPENSSL_armcap"))) {
  50         OPENSSL_armcap_P = strtoul(e, NULL, 0);
  51         return;
  52     }
  53
  54     sigfillset(&all_masked);
  55     sigdelset(&all_masked, SIGILL);
  56     sigdelset(&all_masked, SIGTRAP);
  57     sigdelset(&all_masked, SIGFPE);
  58     sigdelset(&all_masked, SIGBUS);
  59     sigdelset(&all_masked, SIGSEGV);
  60
  61     OPENSSL_armcap_P = 0;
  62
  63     memset(&ill_act, 0, sizeof(ill_act));
  64     ill_act.sa_handler = ill_handler;
  65     ill_act.sa_mask = all_masked;
  66
  67     sigprocmask(SIG_SETMASK, &ill_act.sa_mask, &oset);
  68     sigaction(SIGILL, &ill_act, &ill_oact);
  69
  70     if (sigsetjmp(ill_jmp, 1) == 0) {
  71         _armv7_neon_probe();
  72         OPENSSL_armcap_P |= ARMV7_NEON;
  73     }
  74     if (sigsetjmp(ill_jmp, 1) == 0) {
  75         _armv7_tick();
  76         OPENSSL_armcap_P |= ARMV7_TICK;
  77     }
  78
  79     sigaction(SIGILL, &ill_oact, NULL);
  80     sigprocmask(SIG_SETMASK, &oset, NULL);
  81 }