git: 4626aa7fda0a - main - Add a tool to test AVX context integrity under ctx switches and signals (amd64)

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=4626aa7fda0a677a72a791056fd2d6cad68e944f

commit 4626aa7fda0a677a72a791056fd2d6cad68e944f
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2021-12-13 02:31:40 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2021-12-13 02:31:40 +0000

    Add a tool to test AVX context integrity under ctx switches and signals (amd64)
    
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
---
 tools/test/avx_sig/avx_sig.c | 220 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 220 insertions(+)

diff --git a/tools/test/avx_sig/avx_sig.c b/tools/test/avx_sig/avx_sig.c
new file mode 100644
index 000000000000..711d40f2c231
--- /dev/null
+++ b/tools/test/avx_sig/avx_sig.c
@@ -0,0 +1,220 @@
+/* $Id: avx_sig.c,v 1.12 2021/12/11 22:47:09 kostik Exp $ */
+/*
+ * Naive test to check that context switches and signal delivery do
+ * not corrupt AVX registers file (%xmm).  Run until some
+ * inconsistency detected, then aborts.
+ *
+ * FreeBSD:
+ * ${CC} -Wall -Wextra -O -g -o avx_sig avx_sig.c -lpthread
+ * Linux
+ * ${CC} -D_GNU_SOURCE -Wall -Wextra -O -g -o avx_sig avx_sig.c -lbsd -lpthread
+ */
+
+#include <sys/param.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <sys/syscall.h>
+#include <errno.h>
+#include <pthread.h>
+#ifdef __FreeBSD__
+#include <pthread_np.h>
+#endif
+#ifdef __linux__
+#include <bsd/stdlib.h>
+#endif
+#include <signal.h>
+#include <stdatomic.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#ifndef __unused
+#define	__unused	__attribute__((__unused__))
+#endif
+#ifndef nitems
+#define	nitems(x)	(sizeof((x)) / sizeof((x)[0]))
+#endif
+
+struct xmmreg {
+	uint8_t xmm_bytes[16];
+};
+
+struct xmm {
+	struct xmmreg xmmreg[16];
+};
+
+#define	X2C(r) 	asm("movdqu %0, %%xmm" #r : "=m" (xmm->xmmreg[r]))
+#define	C2X(r)	asm("movdqu %%xmm" #r ", %0" : : "m" (xmm->xmmreg[r]) : "xmm" #r)
+
+static void
+cpu_to_xmm(struct xmm *xmm)
+{
+	C2X(0);	C2X(1);	C2X(2);	C2X(3);	C2X(4);	C2X(5);	C2X(6);	C2X(7);
+	C2X(8);	C2X(9);	C2X(10); C2X(11); C2X(12); C2X(13); C2X(14); C2X(15);
+}
+
+static void
+xmm_to_cpu(struct xmm *xmm)
+{
+	X2C(0);	X2C(1);	X2C(2);	X2C(3);	X2C(4);	X2C(5);	X2C(6);	X2C(7);
+	X2C(8);	X2C(9);	X2C(10); X2C(11); X2C(12); X2C(13); X2C(14); X2C(15);
+}
+
+#undef C2X
+#undef X2C
+
+static atomic_uint sigs;
+
+static void
+sigusr1_handler(int sig __unused, siginfo_t *si __unused, void *m __unused)
+{
+	atomic_fetch_add_explicit(&sigs, 1, memory_order_relaxed);
+}
+
+#ifdef SIGINFO
+static void
+siginfo_handler(int sig __unused)
+{
+	struct rusage r;
+
+	if (getrusage(RUSAGE_SELF, &r) == 0) {
+		printf("%lu vctx %lu nvctx %lu nsigs ",
+		    r.ru_nvcsw, r.ru_nivcsw, r.ru_nsignals);
+	}
+	printf("%u SIGUSR1\n", sigs);
+}
+#endif
+
+static struct xmm zero_xmm = {};
+
+static void
+fill_xmm(struct xmm *xmm)
+{
+	arc4random_buf(xmm, sizeof(*xmm));
+}
+
+static void
+dump_xmm(const struct xmmreg *r)
+{
+	unsigned k;
+
+	for (k = 0; k < nitems(r->xmm_bytes); k++) {
+		if (k != 0)
+			printf(" ");
+		printf("%02x", r->xmm_bytes[k]);
+	}
+	printf("\n");
+}
+
+static pthread_mutex_t show_lock;
+
+static void
+show_diff(const struct xmm *xmm1, const struct xmm *xmm2)
+{
+	const struct xmmreg *r1, *r2;
+	unsigned i, j;
+
+#if defined(__FreeBSD__)
+	printf("thr %d\n", pthread_getthreadid_np());
+#elif defined(__linux__)
+	printf("thr %ld\n", syscall(SYS_gettid));
+#endif
+	for (i = 0; i < nitems(xmm1->xmmreg); i++) {
+		r1 = &xmm1->xmmreg[i];
+		r2 = &xmm2->xmmreg[i];
+		for (j = 0; j < nitems(r1->xmm_bytes); j++) {
+			if (r1->xmm_bytes[j] != r2->xmm_bytes[j]) {
+				printf("xmm%u\n", i);
+				dump_xmm(r1);
+				dump_xmm(r2);
+				break;
+			}
+		}
+	}
+}
+
+static void
+my_pause(void)
+{
+	usleep(0);
+}
+
+static void *
+worker_thread(void *arg __unused)
+{
+	struct xmm xmm, xmm_cpu;
+
+	fill_xmm(&xmm);
+	for (;;) {
+		xmm_to_cpu(&xmm);
+		my_pause();
+		cpu_to_xmm(&xmm_cpu);
+		if (memcmp(&xmm, &xmm_cpu, sizeof(struct xmm)) != 0) {
+			pthread_mutex_lock(&show_lock);
+			show_diff(&xmm, &xmm_cpu);
+			abort();
+			pthread_mutex_unlock(&show_lock);
+		}
+
+		xmm_to_cpu(&zero_xmm);
+		my_pause();
+		cpu_to_xmm(&xmm_cpu);
+		if (memcmp(&zero_xmm, &xmm_cpu, sizeof(struct xmm)) != 0) {
+			pthread_mutex_lock(&show_lock);
+			show_diff(&zero_xmm, &xmm_cpu);
+			abort();
+			pthread_mutex_unlock(&show_lock);
+		}
+	}
+	return (NULL);
+}
+
+int
+main(void)
+{
+	struct sigaction sa;
+	int error, i, ncpu;
+
+#ifdef SIGINFO
+	bzero(&sa, sizeof(sa));
+	sa.sa_handler = siginfo_handler;
+	if (sigaction(SIGINFO, &sa, NULL) == -1) {
+		fprintf(stderr, "sigaction SIGINFO %s\n", strerror(errno));
+		exit(1);
+	}
+#endif
+
+	bzero(&sa, sizeof(sa));
+	sa.sa_sigaction = sigusr1_handler;
+	sa.sa_flags = SA_SIGINFO;
+	if (sigaction(SIGUSR1, &sa, NULL) == -1) {
+		fprintf(stderr, "sigaction SIGUSR1 %s\n", strerror(errno));
+		exit(1);
+	}
+
+	error = pthread_mutex_init(&show_lock, NULL);
+	if (error != 0) {
+		fprintf(stderr, "pthread_mutex_init %s\n", strerror(error));
+		exit(1);
+	}
+
+	ncpu = sysconf(_SC_NPROCESSORS_ONLN);
+	ncpu *= 2;
+	pthread_t wt[ncpu];
+	for (i = 0; i < ncpu; i++) {
+		error = pthread_create(&wt[i], NULL, worker_thread, NULL);
+		if (error != 0) {
+			fprintf(stderr, "pthread_create %s\n", strerror(error));
+		}
+	}
+
+	for (;;) {
+		for (i = 0; i < ncpu; i++) {
+			my_pause();
+			pthread_kill(wt[i], SIGUSR1);
+		}
+	}
+}