cregit-Linux how code gets into the kernel

Release 4.11 tools/testing/selftests/powerpc/math/fpu_signal.c

/*
 * Copyright 2015, Cyril Bur, IBM Corp.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *
 * 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; } } }

Contributors

PersonTokensPropCommitsCommitProp
Cyril Bur73100.00%1100.00%
Total73100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Cyril Bur98100.00%1100.00%
Total98100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Cyril Bur261100.00%1100.00%
Total261100.00%1100.00%


int main(int argc, char *argv[]) { return test_harness(test_signal_fpu, "fpu_signal"); }

Contributors

PersonTokensPropCommitsCommitProp
Cyril Bur21100.00%1100.00%
Total21100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Cyril Bur566100.00%1100.00%
Total566100.00%1100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.