lib/libcrypto/armcap.c

   1 /* $OpenBSD: armcap.c,v 1.6 2014/06/20 21:00:46 deraadt Exp $ */
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include <setjmp.h>
   6 #include <signal.h>
   7 #include <crypto.h>
   8
   9 #include "arm_arch.h"
  10
  11 unsigned int OPENSSL_armcap_P;
  12
  13 #if __ARM_ARCH__ >= 7
  14 static sigset_t all_masked;
  15
  16 static sigjmp_buf ill_jmp;
  17         static void ill_handler (int sig) { 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 #endif
  26
  27 #if defined(__GNUC__) && __GNUC__>=2
  28 void OPENSSL_cpuid_setup(void) __attribute__((constructor));
  29 #endif
  30
  31 void
  32 OPENSSL_cpuid_setup(void)
  33 {
  34 #ifndef __OpenBSD__
  35         char *e;
  36 #endif
  37 #if __ARM_ARCH__ >= 7
  38         struct sigaction        ill_oact, ill_act;
  39         sigset_t                oset;
  40 #endif
  41         static int trigger = 0;
  42
  43         if (trigger)
  44                 return;
  45         trigger = 1;
  46
  47         OPENSSL_armcap_P = 0;
  48
  49 #if __ARM_ARCH__ >= 7
  50         sigfillset(&all_masked);
  51         sigdelset(&all_masked, SIGILL);
  52         sigdelset(&all_masked, SIGTRAP);
  53         sigdelset(&all_masked, SIGFPE);
  54         sigdelset(&all_masked, SIGBUS);
  55         sigdelset(&all_masked, SIGSEGV);
  56
  57         memset(&ill_act, 0, sizeof(ill_act));
  58         ill_act.sa_handler = ill_handler;
  59         ill_act.sa_mask = all_masked;
  60
  61         sigprocmask(SIG_SETMASK, &ill_act.sa_mask, &oset);
  62         sigaction(SIGILL, &ill_act, &ill_oact);
  63
  64         if (sigsetjmp(ill_jmp, 1) == 0) {
  65                 _armv7_neon_probe();
  66                 OPENSSL_armcap_P |= ARMV7_NEON;
  67         }
  68
  69         sigaction (SIGILL, &ill_oact, NULL);
  70         sigprocmask(SIG_SETMASK, &oset, NULL);
  71 #endif
  72 }