1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright 2015, Cyril Bur, IBM Corp. 4 * 5 * This test attempts to see if the FPU registers are correctly reported in a 6 * signal context. Each worker just spins checking its FPU registers, at some 7 * point a signal will interrupt it and C code will check the signal context 8 * ensuring it is also the same. 9 */ 10 11 #include <stdio.h> 12 #include <unistd.h> 13 #include <sys/syscall.h> 14 #include <sys/time.h> 15 #include <sys/types.h> 16 #include <sys/wait.h> 17 #include <stdlib.h> 18 #include <pthread.h> 19 20 #include "utils.h" 21 #include "fpu.h" 22 23 /* Number of times each thread should receive the signal */ 24 #define ITERATIONS 10 25 /* 26 * Factor by which to multiply number of online CPUs for total number of 27 * worker threads 28 */ 29 #define THREAD_FACTOR 8 30 31 __thread double darray[32]; 32 33 bool bad_context; 34 int threads_starting; 35 int running; 36 37 extern long preempt_fpu(double *darray, int *threads_starting, int *running); 38 39 void signal_fpu_sig(int sig, siginfo_t *info, void *context) 40 { 41 int i; 42 ucontext_t *uc = context; 43 mcontext_t *mc = &uc->uc_mcontext; 44 45 // Don't check f30/f31, they're used as scratches in check_all_fprs() 46 for (i = 0; i < 30; i++) { 47 if (mc->fp_regs[i] != darray[i]) { 48 bad_context = true; 49 break; 50 } 51 } 52 } 53 54 void *signal_fpu_c(void *p) 55 { 56 long rc; 57 struct sigaction act; 58 act.sa_sigaction = signal_fpu_sig; 59 act.sa_flags = SA_SIGINFO; 60 rc = sigaction(SIGUSR1, &act, NULL); 61 if (rc) 62 return p; 63 64 srand(pthread_self()); 65 randomise_darray(darray, ARRAY_SIZE(darray)); 66 rc = preempt_fpu(darray, &threads_starting, &running); 67 68 return (void *) rc; 69 } 70 71 int test_signal_fpu(void) 72 { 73 int i, j, rc, threads; 74 void *rc_p; 75 pthread_t *tids; 76 77 threads = sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR; 78 tids = malloc(threads * sizeof(pthread_t)); 79 FAIL_IF(!tids); 80 81 running = true; 82 threads_starting = threads; 83 for (i = 0; i < threads; i++) { 84 rc = pthread_create(&tids[i], NULL, signal_fpu_c, NULL); 85 FAIL_IF(rc); 86 } 87 88 setbuf(stdout, NULL); 89 printf("\tWaiting for all workers to start..."); 90 while (threads_starting) 91 asm volatile("": : :"memory"); 92 printf("done\n"); 93 94 printf("\tSending signals to all threads %d times...", ITERATIONS); 95 for (i = 0; i < ITERATIONS; i++) { 96 for (j = 0; j < threads; j++) { 97 pthread_kill(tids[j], SIGUSR1); 98 } 99 sleep(1); 100 } 101 printf("done\n"); 102 103 printf("\tStopping workers..."); 104 running = 0; 105 for (i = 0; i < threads; i++) { 106 pthread_join(tids[i], &rc_p); 107 108 /* 109 * Harness will say the fail was here, look at why signal_fpu 110 * returned 111 */ 112 if ((long) rc_p || bad_context) 113 printf("oops\n"); 114 if (bad_context) 115 fprintf(stderr, "\t!! bad_context is true\n"); 116 FAIL_IF((long) rc_p || bad_context); 117 } 118 printf("done\n"); 119 120 free(tids); 121 return 0; 122 } 123 124 int main(int argc, char *argv[]) 125 { 126 return test_harness(test_signal_fpu, "fpu_signal"); 127 } 128