efi_selftest: use standalone UEFI program for exception

To fully demonstrate crash outputs for UEFI images provide a standalone
UEFI application that tries to invoke an illegal opcode.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

lib/efi_selftest/Makefile

@@ -20,7 +20,6 @@ efi_selftest_crc32.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_gop.o \
 efi_selftest_loaded_image.o \
@@ -60,16 +59,23 @@ endif
 ifeq ($(CONFIG_SANDBOX)$(CONFIG_CPU_V7M),)
 
 obj-y += \
+efi_selftest_exception.o \
 efi_selftest_loadimage.o \
 efi_selftest_startimage_exit.o \
 efi_selftest_startimage_return.o
 
 targets += \
+efi_miniapp_file_image_exception.h \
 efi_miniapp_file_image_exit.h \
 efi_miniapp_file_image_return.h \
+efi_selftest_miniapp_exception.efi \
 efi_selftest_miniapp_exit.efi \
 efi_selftest_miniapp_return.efi
 
+$(obj)/efi_miniapp_file_image_exception.h: $(obj)/efi_selftest_miniapp_exception.efi
+	$(obj)/../../tools/file2include $(obj)/efi_selftest_miniapp_exception.efi > \
+	$(obj)/efi_miniapp_file_image_exception.h
+
 $(obj)/efi_miniapp_file_image_exit.h: $(obj)/efi_selftest_miniapp_exit.efi
 	$(obj)/../../tools/file2include $(obj)/efi_selftest_miniapp_exit.efi > \
 	$(obj)/efi_miniapp_file_image_exit.h
@@ -80,6 +86,8 @@ $(obj)/efi_miniapp_file_image_return.h: $(obj)/efi_selftest_miniapp_return.efi
 
 $(obj)/efi_selftest_loadimage.o: $(obj)/efi_miniapp_file_image_exit.h
 
+$(obj)/efi_selftest_exception.o: $(obj)/efi_miniapp_file_image_exception.h
+
 $(obj)/efi_selftest_startimage_exit.o: $(obj)/efi_miniapp_file_image_exit.h
 
 $(obj)/efi_selftest_startimage_return.o: $(obj)/efi_miniapp_file_image_return.h

lib/efi_selftest/efi_selftest_exception.c

@@ -2,42 +2,138 @@
 /*
  * efi_selftest_exception
  *
- * Copyright (c) 2018 Heinrich Schuchardt <xypron.glpk@gmx.de>
+ * Copyright (c) 2019 Heinrich Schuchardt <xypron.glpk@gmx.de>
  *
- * Test the handling of exceptions by trying to execute an undefined
- * instruction.
+ * This test checks the handling of exceptions.
+ *
+ * The efi_selftest_miniapp_exception.efi application is loaded into memory
+ * and started.
  */
 
 #include <efi_selftest.h>
+/* Include containing the UEFI application */
+#include "efi_miniapp_file_image_exception.h"
 
-/**
- * undefined_instruction() - try to executed an undefined instruction
+/* Block size of compressed disk image */
+#define COMPRESSED_DISK_IMAGE_BLOCK_SIZE 8
+
+/* Binary logarithm of the block size */
+#define LB_BLOCK_SIZE 9
+
+/* File device path for LoadImage() */
+static struct {
+	struct efi_device_path dp;
+	u16 filename[8];
+	struct efi_device_path end;
+} dp = {
+	{
+		DEVICE_PATH_TYPE_MEDIA_DEVICE,
+		DEVICE_PATH_SUB_TYPE_FILE_PATH,
+		sizeof(dp.dp) + sizeof(dp.filename),
+	},
+	L"bug.efi",
+	{
+		DEVICE_PATH_TYPE_END,
+		DEVICE_PATH_SUB_TYPE_END,
+		sizeof(dp.end),
+	}
+};
+
+static efi_handle_t image_handle;
+static struct efi_boot_services *boottime;
+
+/* One 8 byte block of the compressed disk image */
+struct line {
+	size_t addr;
+	char *line;
+};
+
+/* Compressed file image */
+struct compressed_file_image {
+	size_t length;
+	struct line lines[];
+};
+
+static struct compressed_file_image img = EFI_ST_DISK_IMG;
+
+/* Decompressed file image */
+static u8 *image;
+
+/*
+ * Decompress the disk image.
+ *
+ * @image	decompressed disk image
+ * @return	status code
  */
-static void undefined_instruction(void)
+static efi_status_t decompress(u8 **image)
 {
-#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
+	u8 *buf;
+	size_t i;
+	size_t addr;
+	size_t len;
+	efi_status_t ret;
+
+	ret = boottime->allocate_pool(EFI_LOADER_DATA, img.length,
+				      (void **)&buf);
+	if (ret != EFI_SUCCESS) {
+		efi_st_error("Out of memory\n");
+		return ret;
+	}
+	boottime->set_mem(buf, img.length, 0);
+
+	for (i = 0; ; ++i) {
+		if (!img.lines[i].line)
+			break;
+		addr = img.lines[i].addr;
+		len = COMPRESSED_DISK_IMAGE_BLOCK_SIZE;
+		if (addr + len > img.length)
+			len = img.length - addr;
+		boottime->copy_mem(buf + addr, img.lines[i].line, len);
+	}
+	*image = buf;
+	return ret;
 }
 
-/**
- * execute() - execute unit test
+/*
+ * Setup unit test.
  *
- * Return:	EFI_ST_SUCCESS for success
+ * @handle:	handle of the loaded image
+ * @systable:	system table
+ * @return:	EFI_ST_SUCCESS for success
+ */
+static int setup(const efi_handle_t handle,
+		 const struct efi_system_table *systable)
+{
+	image_handle = handle;
+	boottime = systable->boottime;
+
+	/* Load the application image into memory */
+	decompress(&image);
+
+	return EFI_ST_SUCCESS;
+}
+
+/*
+ * Execute unit test.
+ *
+ * Load and start the application image.
+ *
+ * @return:	EFI_ST_SUCCESS for success
  */
 static int execute(void)
 {
-	undefined_instruction();
+	efi_status_t ret;
+	efi_handle_t handle;
 
-	efi_st_error("An undefined instruction exception was not raised\n");
+	ret = boottime->load_image(false, image_handle, &dp.dp, image,
+				   img.length, &handle);
+	if (ret != EFI_SUCCESS) {
+		efi_st_error("Failed to load image\n");
+		return EFI_ST_FAILURE;
+	}
+	ret = boottime->start_image(handle, NULL, NULL);
+
+	efi_st_error("Exception not triggered\n");
 
 	return EFI_ST_FAILURE;
 }
@@ -45,6 +141,7 @@ static int execute(void)
 EFI_UNIT_TEST(exception) = {
 	.name = "exception",
 	.phase = EFI_EXECUTE_BEFORE_BOOTTIME_EXIT,
+	.setup = setup,
 	.execute = execute,
 	.on_request = true,
 };

lib/efi_selftest/efi_selftest_miniapp_exception.c

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * efi_selftest_miniapp_return
+ *
+ * Copyright (c) 2019 Heinrich Schuchardt
+ *
+ * This EFI application triggers an exception.
+ */
+
+#include <common.h>
+#include <efi_api.h>
+
+/*
+ * Entry point of the EFI application.
+ *
+ * @handle	handle of the loaded image
+ * @systable	system table
+ * @return	status code
+ */
+efi_status_t EFIAPI efi_main(efi_handle_t handle,
+			     struct efi_system_table *systable)
+{
+	struct efi_simple_text_output_protocol *con_out = systable->con_out;
+
+	con_out->output_string(con_out,
+			       L"EFI application triggers exception.\n");
+
+#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
+	con_out->output_string(con_out, L"Exception not triggered.\n");
+	return EFI_ABORTED;
+}