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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright IBM Corp. 2020
*
* This test attempts to cause a FP denormal exception on POWER8 CPUs. Unfortunately
* if the denormal handler is not configured or working properly, this can cause a bad
* crash in kernel mode when the kernel tries to save FP registers when the process
* exits.
*/
#include <stdio.h>
#include <string.h>
#include "utils.h"
static int test_denormal_fpu(void)
{
unsigned int m32;
unsigned long m64;
volatile float f;
volatile double d;
/* try to induce lfs <denormal> ; stfd */
m32 = 0x00715fcf; /* random denormal */
memcpy((float *)&f, &m32, sizeof(f));
d = f;
memcpy(&m64, (double *)&d, sizeof(d));
FAIL_IF((long)(m64 != 0x380c57f3c0000000)); /* renormalised value */
return 0;
}
int main(int argc, char *argv[])
{
return test_harness(test_denormal_fpu, "fpu_denormal");
}
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