// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright 2015, Cyril Bur, IBM Corp.
*
* This test attempts to see if the FPU registers are correctly reported in a
* signal context. Each worker just spins checking its FPU registers, at some
* point a signal will interrupt it and C code will check the signal context
* ensuring it is also the same.
*/
#include <stdio.h>
#include <unistd.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <stdlib.h>
#include <pthread.h>
#include "utils.h"
/* Number of times each thread should receive the signal */
#define ITERATIONS 10
/*
* Factor by which to multiply number of online CPUs for total number of
* worker threads
*/
#define THREAD_FACTOR 8
__thread double darray[] = {0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0,
1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0,
2.1};
bool bad_context;
int threads_starting;
int running;
extern long preempt_fpu(double *darray, int *threads_starting, int *running);
void signal_fpu_sig(int sig, siginfo_t *info, void *context)
{
int i;
ucontext_t *uc = context;
mcontext_t *mc = &uc->uc_mcontext;
/* Only the non volatiles were loaded up */
for (i = 14; i < 32; i++) {
if (mc->fp_regs[i] != darray[i - 14]) {
bad_context = true;
break;
}
}
}
void *signal_fpu_c(void *p)
{
int i;
long rc;
struct sigaction act;
act.sa_sigaction = signal_fpu_sig;
act.sa_flags = SA_SIGINFO;
rc = sigaction(SIGUSR1, &act, NULL);
if (rc)
return p;
srand(pthread_self());
for (i = 0; i < 21; i++)
darray[i] = rand();
rc = preempt_fpu(darray, &threads_starting, &running);
return (void *) rc;
}
int test_signal_fpu(void)
{
int i, j, rc, threads;
void *rc_p;
pthread_t *tids;
threads = sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR;
tids = malloc(threads * sizeof(pthread_t));
FAIL_IF(!tids);
running = true;
threads_starting = threads;
for (i = 0; i < threads; i++) {
rc = pthread_create(&tids[i], NULL, signal_fpu_c, NULL);
FAIL_IF(rc);
}
setbuf(stdout, NULL);
printf("\tWaiting for all workers to start...");
while (threads_starting)
asm volatile("": : :"memory");
printf("done\n");
printf("\tSending signals to all threads %d times...", ITERATIONS);
for (i = 0; i < ITERATIONS; i++) {
for (j = 0; j < threads; j++) {
pthread_kill(tids[j], SIGUSR1);
}
sleep(1);
}
printf("done\n");
printf("\tStopping workers...");
running = 0;
for (i = 0; i < threads; i++) {
pthread_join(tids[i], &rc_p);
/*
* Harness will say the fail was here, look at why signal_fpu
* returned
*/
if ((long) rc_p || bad_context)
printf("oops\n");
if (bad_context)
fprintf(stderr, "\t!! bad_context is true\n");
FAIL_IF((long) rc_p || bad_context);
}
printf("done\n");
free(tids);
return 0;
}
int main(int argc, char *argv[])
{
return test_harness(test_signal_fpu, "fpu_signal");
}
