1 /* 2 * Copyright 2015, Cyril Bur, IBM Corp. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * This test attempts to see if the FPU registers are correctly reported in a 10 * signal context. Each worker just spins checking its FPU registers, at some 11 * point a signal will interrupt it and C code will check the signal context 12 * ensuring it is also the same. 13 */ 14 15 #include <stdio.h> 16 #include <unistd.h> 17 #include <sys/syscall.h> 18 #include <sys/time.h> 19 #include <sys/types.h> 20 #include <sys/wait.h> 21 #include <stdlib.h> 22 #include <pthread.h> 23 24 #include "utils.h" 25 26 /* Number of times each thread should receive the signal */ 27 #define ITERATIONS 10 28 /* 29 * Factor by which to multiply number of online CPUs for total number of 30 * worker threads 31 */ 32 #define THREAD_FACTOR 8 33 34 __thread double darray[] = {0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 35 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 36 2.1}; 37 38 bool bad_context; 39 int threads_starting; 40 int running; 41 42 extern long preempt_fpu(double *darray, int *threads_starting, int *running); 43 44 void signal_fpu_sig(int sig, siginfo_t *info, void *context) 45 { 46 int i; 47 ucontext_t *uc = context; 48 mcontext_t *mc = &uc->uc_mcontext; 49 50 /* Only the non volatiles were loaded up */ 51 for (i = 14; i < 32; i++) { 52 if (mc->fp_regs[i] != darray[i - 14]) { 53 bad_context = true; 54 break; 55 } 56 } 57 } 58 59 void *signal_fpu_c(void *p) 60 { 61 int i; 62 long rc; 63 struct sigaction act; 64 act.sa_sigaction = signal_fpu_sig; 65 act.sa_flags = SA_SIGINFO; 66 rc = sigaction(SIGUSR1, &act, NULL); 67 if (rc) 68 return p; 69 70 srand(pthread_self()); 71 for (i = 0; i < 21; i++) 72 darray[i] = rand(); 73 74 rc = preempt_fpu(darray, &threads_starting, &running); 75 76 return (void *) rc; 77 } 78 79 int test_signal_fpu(void) 80 { 81 int i, j, rc, threads; 82 void *rc_p; 83 pthread_t *tids; 84 85 threads = sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR; 86 tids = malloc(threads * sizeof(pthread_t)); 87 FAIL_IF(!tids); 88 89 running = true; 90 threads_starting = threads; 91 for (i = 0; i < threads; i++) { 92 rc = pthread_create(&tids[i], NULL, signal_fpu_c, NULL); 93 FAIL_IF(rc); 94 } 95 96 setbuf(stdout, NULL); 97 printf("\tWaiting for all workers to start..."); 98 while (threads_starting) 99 asm volatile("": : :"memory"); 100 printf("done\n"); 101 102 printf("\tSending signals to all threads %d times...", ITERATIONS); 103 for (i = 0; i < ITERATIONS; i++) { 104 for (j = 0; j < threads; j++) { 105 pthread_kill(tids[j], SIGUSR1); 106 } 107 sleep(1); 108 } 109 printf("done\n"); 110 111 printf("\tStopping workers..."); 112 running = 0; 113 for (i = 0; i < threads; i++) { 114 pthread_join(tids[i], &rc_p); 115 116 /* 117 * Harness will say the fail was here, look at why signal_fpu 118 * returned 119 */ 120 if ((long) rc_p || bad_context) 121 printf("oops\n"); 122 if (bad_context) 123 fprintf(stderr, "\t!! bad_context is true\n"); 124 FAIL_IF((long) rc_p || bad_context); 125 } 126 printf("done\n"); 127 128 free(tids); 129 return 0; 130 } 131 132 int main(int argc, char *argv[]) 133 { 134 return test_harness(test_signal_fpu, "fpu_signal"); 135 } 136