[PATCH 2/3] [POC] Add rt_signal test

[Johannes Kirchmair <johannes.kirchmair@sigmatek.at>]

This commit adds simple rt signal test for SIGFPE, SIGILL and SIGSEGV.
---
 configure.ac                               |   1 +
 testsuite/Makefile.am                      |   1 +
 testsuite/rt-signal-tests/Makefile.am      |  31 +++
 testsuite/rt-signal-tests/rt_signal_test.c | 231 +++++++++++++++++++++
 4 files changed, 264 insertions(+)
 create mode 100644 testsuite/rt-signal-tests/Makefile.am
 create mode 100644 testsuite/rt-signal-tests/rt_signal_test.c

diff --git a/configure.ac b/configure.ac
index 3ce34048e..3325482fc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1007,6 +1007,7 @@ AC_CONFIG_FILES([ \
 	testsuite/switchtest/Makefile \
 	testsuite/gpiotest/Makefile \
 	testsuite/gpiobench/Makefile \
+	testsuite/rt-signal-tests/Makefile \
 	testsuite/spitest/Makefile \
 	testsuite/smokey/Makefile \
 	testsuite/smokey/arith/Makefile \
diff --git a/testsuite/Makefile.am b/testsuite/Makefile.am
index 4932f6d33..59f36967a 100644
--- a/testsuite/Makefile.am
+++ b/testsuite/Makefile.am
@@ -5,6 +5,7 @@ if XENO_COBALT
 SUBDIRS += 		\
 	clocktest	\
 	gpiotest	\
+	rt-signal-tests	\
 	spitest		\
 	switchtest	\
 	xeno-test
diff --git a/testsuite/rt-signal-tests/Makefile.am b/testsuite/rt-signal-tests/Makefile.am
new file mode 100644
index 000000000..084347631
--- /dev/null
+++ b/testsuite/rt-signal-tests/Makefile.am
@@ -0,0 +1,31 @@
+testdir = @XENO_TEST_DIR@
+
+CCLD = $(top_srcdir)/scripts/wrap-link.sh $(CC)
+
+test_PROGRAMS = rt_signal_test_fpe rt_signal_test_segfault rt_signal_test_ill
+
+alchemycppflags =              			 \
+	$(XENO_USER_CFLAGS)    			 \
+	-I$(top_srcdir)/include
+
+alchemyldadd =					\
+	@XENO_AUTOINIT_LDFLAGS@			\
+	$(XENO_POSIX_WRAPPERS)			\
+	../../lib/alchemy/libalchemy.la		\
+	../../lib/copperplate/libcopperplate.la	\
+	@XENO_CORE_LDADD@			\
+	@XENO_USER_LDADD@			\
+	-lrt -lpthread -lm
+
+rt_signal_test_fpe_SOURCES = rt_signal_test.c
+rt_signal_test_fpe_CPPFLAGS = $(alchemycppflags) -DTEST_FPE=1
+rt_signal_test_fpe_LDADD = $(alchemyldadd)
+
+rt_signal_test_segfault_SOURCES = rt_signal_test.c
+rt_signal_test_segfault_CPPFLAGS = $(alchemycppflags) -DTEST_SEGFAULT=1
+rt_signal_test_segfault_LDADD = $(alchemyldadd)
+
+rt_signal_test_ill_SOURCES = rt_signal_test.c
+rt_signal_test_ill_CPPFLAGS = $(alchemycppflags)
+rt_signal_test_ill_LDADD = $(alchemyldadd)
+
diff --git a/testsuite/rt-signal-tests/rt_signal_test.c b/testsuite/rt-signal-tests/rt_signal_test.c
new file mode 100644
index 000000000..ef569b30d
--- /dev/null
+++ b/testsuite/rt-signal-tests/rt_signal_test.c
@@ -0,0 +1,231 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <copperplate/traceobj.h>
+#include <alchemy/task.h>
+#include <assert.h>
+#include <setjmp.h>
+#include <asm/ucontext.h>
+
+#ifdef TEST_SEGFAULT
+#define TEST_SIGNAL SIGSEGV
+#elif defined(TEST_FPE)
+#define TEST_SIGNAL SIGFPE
+#else
+#define TEST_SIGNAL SIGILL
+#endif
+
+#define BIT_FAULT_HANDLER_ENTERD     1
+#define BIT_FAULT_HANDLER_FINISHED   2
+#define BIT_FAULT_HANDLER_WRONG_TASK 4
+#define BIT_FAULT_HANDLER_WRONG_SIG  8
+#define BIT_DOMAIN_SWITCH            16
+
+static RT_TASK t1;
+static sig_atomic_t status = 0;
+static sig_atomic_t cause = 0;
+
+// #define JMP_CLEANUP
+#ifdef JMP_CLEANUP
+static jmp_buf jmpenv;
+#endif
+
+static int status_ok(void)
+{
+	return status ==
+	       (BIT_FAULT_HANDLER_ENTERD | BIT_FAULT_HANDLER_FINISHED);
+}
+
+static const char *sigdebug_msg[] = {
+	[SIGDEBUG_UNDEFINED] = "latency: received SIGXCPU for unknown reason",
+	[SIGDEBUG_MIGRATE_SIGNAL] = "received signal",
+	[SIGDEBUG_MIGRATE_SYSCALL] = "invoked syscall",
+	[SIGDEBUG_MIGRATE_FAULT] = "triggered fault",
+	[SIGDEBUG_MIGRATE_PRIOINV] = "affected by priority inversion",
+	[SIGDEBUG_NOMLOCK] = "Xenomai: process memory not locked "
+			     "(missing mlockall?)",
+	[SIGDEBUG_WATCHDOG] = "Xenomai: watchdog triggered "
+			      "(period too short?)",
+};
+
+
+#ifndef JMP_CLEANUP
+static int get_step(void)
+{
+#ifdef TEST_SEGFAULT
+#if defined(__i386__) || defined(__x86_64__)
+	return 11;
+#else
+	return 4;
+#endif
+#elif defined(TEST_FPE)
+	return 2;
+#else
+#if defined(__i386__) || defined(__x86_64__)
+	return 2;
+#else
+	return 4;
+#endif
+#endif
+}
+
+static void do_cleanup(void *context)
+{
+	int step = 0;
+	struct ucontext *uc = context;
+
+	step = get_step();
+
+#if defined(__i386__)
+	uc->uc_mcontext.eip += step;
+#elif defined(__x86_64__)
+	uc->uc_mcontext.rip += step;
+#elif defined(__aarch64__)
+	uc->uc_mcontext.pc += step;
+#endif
+}
+#endif
+
+static void signal_handler(int sig, siginfo_t *info, void *context)
+{
+	RT_TASK *self;
+	(void)context;
+
+	if (sig == SIGDEBUG) {
+		cause = sigdebug_reason(info);
+
+		if (cause > SIGDEBUG_WATCHDOG)
+			cause = SIGDEBUG_UNDEFINED;
+
+		/* XXX: caused by rt_task_delete() */
+		if (!(status & BIT_FAULT_HANDLER_ENTERD) &&
+		    cause == SIGDEBUG_MIGRATE_SYSCALL) {
+			return;
+		}
+
+		status |= BIT_DOMAIN_SWITCH;
+	} else {
+		status |= BIT_FAULT_HANDLER_ENTERD;
+		if (sig != TEST_SIGNAL) {
+			status |= BIT_FAULT_HANDLER_WRONG_SIG;
+			return;
+		}
+
+		self = rt_task_self();
+
+		if (self == NULL || !rt_task_same(self, &t1)) {
+			status |= BIT_FAULT_HANDLER_WRONG_TASK;
+		} else {
+			status |= BIT_FAULT_HANDLER_FINISHED;
+		}
+
+#ifdef JMP_CLEANUP
+		longjmp(jmpenv, 1);
+#else
+		do_cleanup(context);
+#endif
+	}
+}
+
+static void do_div_by_0(void)
+{
+#if defined(__i386__) || defined (__x86_64__)
+	__asm__("xorl %eax, %eax\n\t"
+		"movl %eax, %ecx\n\t"
+		"cltd\n\t"
+		"idivl %ecx");
+#endif
+	//TODO find a cortex-A way to trigger an FPE
+}
+
+static void do_ill(void)
+{
+#if defined(__i386__) || defined (__x86_64__)
+	__asm__("ud2");
+#else
+	__asm__("udf #0xdead");
+#endif
+}
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Warray-bounds"
+static void do_segfault(void)
+{
+	*((int *)0x73) = 0xdecafbad;
+}
+#pragma GCC diagnostic pop
+
+static void task_proc(void *arg)
+{
+	int ret;
+	(void)arg;
+
+	ret = cobalt_rt_signal(TEST_SIGNAL, signal_handler);
+	assert(ret == 0);
+	(void)ret;
+
+#ifdef JMP_CLEANUP
+	if (setjmp(jmpenv) != 0)
+		return;
+#endif
+
+#ifdef TEST_SEGFAULT
+	do_segfault();
+#elif defined(TEST_FPE)
+	do_div_by_0();
+#else
+	do_ill();
+#endif
+
+	if (0) { // so we don't geht defined but not used errors
+		do_segfault();
+		do_div_by_0();
+		do_ill();
+	}
+}
+
+static int test_sucessfull(void)
+{
+	if (status_ok()) {
+		fputs("Test passed\n", stderr);
+		return 1;
+	}
+
+	if (!(status & BIT_FAULT_HANDLER_ENTERD))
+		fputs("Test failed: signal handler not invoked!\n", stderr);
+	if ((status & BIT_FAULT_HANDLER_WRONG_TASK))
+		fputs("Test failed: Signal handler in wrong task!\n", stderr);
+	if ((status & BIT_FAULT_HANDLER_WRONG_SIG))
+		fputs("Test failed: Signal handler of wrong signal!\n", stderr);
+	if ((status & BIT_DOMAIN_SWITCH)) {
+		fputs("Test failed: domain switch happened!\n", stderr);
+		fprintf(stderr, "Caused by: %s\n", sigdebug_msg[cause]);
+	}
+
+	return 0;
+}
+
+int main(void)
+{
+	struct sigaction sa;
+	int ret;
+
+	memset(&sa, 0, sizeof(sa));
+	sa.sa_sigaction = signal_handler;
+	sa.sa_flags = SA_SIGINFO | SA_NODEFER;
+	sigaction(TEST_SIGNAL, &sa, NULL);
+	sigaction(SIGDEBUG, &sa, NULL);
+
+	ret = rt_task_create(&t1, "rt-task", 0, 20, T_JOINABLE | T_WARNSW);
+	assert(ret == 0);
+
+	ret = rt_task_start(&t1, task_proc, NULL);
+	assert(ret == 0);
+
+	ret = rt_task_join(&t1);
+	assert(ret == 0);
+	(void)ret; // so the compiler does not complain about not checking ret
+
+	return test_sucessfull() ? EXIT_SUCCESS : EXIT_FAILURE;
+}
-- 
2.25.1