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
38bool bad_context;
39int threads_starting;
40int running;
41
42extern long preempt_fpu(double *darray, int *threads_starting, int *running);
43
44void 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
59void *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
79int 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
132int main(int argc, char *argv[])
133{
134	return test_harness(test_signal_fpu, "fpu_signal");
135}
136