| // 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"); | |
| } |