openssl/crypto/s390xcap.c

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

extern unsigned long OPENSSL_s390xcap_P;

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

unsigned long OPENSSL_s390x_facilities(void);

void OPENSSL_cpuid_setup(void)
{
    sigset_t oset;
    struct sigaction ill_act, oact;

    if (OPENSSL_s390xcap_P)
        return;

    memset(&ill_act, 0, sizeof(ill_act));
    ill_act.sa_handler = ill_handler;
    sigfillset(&ill_act.sa_mask);
    sigdelset(&ill_act.sa_mask, SIGILL);
    sigdelset(&ill_act.sa_mask, SIGTRAP);
    sigprocmask(SIG_SETMASK, &ill_act.sa_mask, &oset);
    sigaction(SIGILL, &ill_act, &oact);

    /* protection against missing store-facility-list-extended */
    if (sigsetjmp(ill_jmp, 0) == 0)
        OPENSSL_s390xcap_P = OPENSSL_s390x_facilities();
    else
        OPENSSL_s390xcap_P = 1UL << 63;

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