armcap.c

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <setjmp.h>
#include <signal.h>
#include <crypto.h>

#include "arm_arch.h"

unsigned int OPENSSL_armcap_P;

static sigset_t all_masked;

static sigjmp_buf ill_jmp;
static void ill_handler (int sig) { siglongjmp(ill_jmp,sig); }

/*
 * Following subroutines could have been inlined, but it's not all
 * ARM compilers support inline assembler...
 */
void _armv7_neon_probe(void);
unsigned int _armv7_tick(void);

unsigned int OPENSSL_rdtsc(void)
    {
    if (OPENSSL_armcap_P|ARMV7_TICK)
        return _armv7_tick();
    else
        return 0;
    }

#if defined(__GNUC__) && __GNUC__>=2
void OPENSSL_cpuid_setup(void) __attribute__((constructor));
#endif
void OPENSSL_cpuid_setup(void)
    {
    char *e;
    struct sigaction    ill_oact,ill_act;
    sigset_t        oset;
    static int trigger=0;

    if (trigger) return;
    trigger=1;
 
    if ((e=getenv("OPENSSL_armcap")))
        {
        OPENSSL_armcap_P=strtoul(e,NULL,0);
        return;
        }

    sigfillset(&all_masked);
    sigdelset(&all_masked,SIGILL);
    sigdelset(&all_masked,SIGTRAP);
    sigdelset(&all_masked,SIGFPE);
    sigdelset(&all_masked,SIGBUS);
    sigdelset(&all_masked,SIGSEGV);

    OPENSSL_armcap_P = 0;

    memset(&ill_act,0,sizeof(ill_act));
    ill_act.sa_handler = ill_handler;
    ill_act.sa_mask    = all_masked;

    sigprocmask(SIG_SETMASK,&ill_act.sa_mask,&oset);
    sigaction(SIGILL,&ill_act,&ill_oact);

    if (sigsetjmp(ill_jmp,1) == 0)
        {
        _armv7_neon_probe();
        OPENSSL_armcap_P |= ARMV7_NEON;
        }
    if (sigsetjmp(ill_jmp,1) == 0)
        {
        _armv7_tick();
        OPENSSL_armcap_P |= ARMV7_TICK;
        }

    sigaction (SIGILL,&ill_oact,NULL);
    sigprocmask(SIG_SETMASK,&oset,NULL);
    }