efi_selftest: test handling of exceptions

Test the handling of execptions by trying to execute an undefined
instruction. For 32bit ARM we expect \selftest to be listed as loaded
image.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

lib/efi_selftest/Makefile

@@ -21,6 +21,7 @@ efi_selftest_devicepath.o \
 efi_selftest_devicepath_util.o \
 efi_selftest_events.o \
 efi_selftest_event_groups.o \
+efi_selftest_exception.o \
 efi_selftest_exitbootservices.o \
 efi_selftest_fdt.o \
 efi_selftest_gop.o \

lib/efi_selftest/efi_selftest_exception.c

@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * efi_selftest_exception
+ *
+ * Copyright (c) 2018 Heinrich Schuchardt <xypron.glpk@gmx.de>
+ *
+ * Test the handling of execptions by trying to execute an undefined
+ * instruction.
+ */
+
+#include <efi_selftest.h>
+
+/**
+ * undefined_instruction() - try to executed an undefined instruction
+ */
+static void undefined_instruction(void)
+{
+#if defined(CONFIG_ARM)
+	/*
+	 * 0xe7f...f.	is undefined in ARM mode
+	 * 0xde..	is undefined in Thumb mode
+	 */
+	asm volatile (".word 0xe7f7defb\n");
+#elif defined(CONFIG_RISCV)
+	asm volatile (".word 0xffffffff\n");
+#elif defined(CONFIG_X86)
+	asm volatile (".word 0xffff\n");
+#endif
+}
+
+/**
+ * execute() - execute unit test
+ *
+ * Return:	EFI_ST_SUCCESS for success
+ */
+static int execute(void)
+{
+	undefined_instruction();
+
+	efi_st_error("An undefined instruction exeption was not raised\n");
+
+	return EFI_ST_FAILURE;
+}
+
+EFI_UNIT_TEST(exception) = {
+	.name = "exception",
+	.phase = EFI_EXECUTE_BEFORE_BOOTTIME_EXIT,
+	.execute = execute,
+	.on_request = true,
+};