From 556d8dc937f74fa8a5fa849b7e1393db3446f3b2 Mon Sep 17 00:00:00 2001
From: Heinrich Schuchardt <xypron.glpk@gmx.de>
Date: Tue, 30 Apr 2019 17:57:30 +0200
Subject: [PATCH] efi_loader: implement support of exit data
In case of a failure exit data may be passed to Exit() which in turn is
returned by StartImage().
Let the `bootefi` command print the exit data string in case of an error.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
---
cmd/bootefi.c | 11 +++++---
include/efi_loader.h | 5 ++++
lib/efi_loader/efi_boottime.c | 47 +++++++++++++++++++++++++++++++++++
3 files changed, 60 insertions(+), 3 deletions(-)
diff --git a/cmd/bootefi.c b/cmd/bootefi.c
index b93d8c6a32..f1d7d8bc66 100644
--- a/cmd/bootefi.c
+++ b/cmd/bootefi.c
@@ -297,6 +297,8 @@ static efi_status_t efi_install_fdt(const char *fdt_opt)
static efi_status_t do_bootefi_exec(efi_handle_t handle)
{
efi_status_t ret;
+ efi_uintn_t exit_data_size = 0;
+ u16 *exit_data = NULL;
/* Transfer environment variable as load options */
ret = set_load_options(handle, "bootargs");
@@ -304,7 +306,12 @@ static efi_status_t do_bootefi_exec(efi_handle_t handle)
return ret;
/* Call our payload! */
- ret = EFI_CALL(efi_start_image(handle, NULL, NULL));
+ ret = EFI_CALL(efi_start_image(handle, &exit_data_size, &exit_data));
+ printf("## Application terminated, r = %lu\n", ret & ~EFI_ERROR_MASK);
+ if (ret && exit_data) {
+ printf("## %ls\n", exit_data);
+ efi_free_pool(exit_data);
+ }
efi_restore_gd();
@@ -357,7 +364,6 @@ static int do_efibootmgr(const char *fdt_opt)
}
ret = do_bootefi_exec(handle);
- printf("## Application terminated, r = %lu\n", ret & ~EFI_ERROR_MASK);
if (ret != EFI_SUCCESS)
return CMD_RET_FAILURE;
@@ -472,7 +478,6 @@ static int do_bootefi_image(const char *image_opt, const char *fdt_opt)
goto out;
ret = do_bootefi_exec(handle);
- printf("## Application terminated, r = %lu\n", ret & ~EFI_ERROR_MASK);
out:
if (mem_handle)
diff --git a/include/efi_loader.h b/include/efi_loader.h
index 07b913d256..7af3f16ef8 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -207,12 +207,17 @@ struct efi_object {
* struct efi_loaded_image_obj - handle of a loaded image
*
* @header: EFI object header
+ * @exit_status: exit status passed to Exit()
+ * @exit_data_size: exit data size passed to Exit()
+ * @exit_data: exit data passed to Exit()
* @exit_jmp: long jump buffer for returning form started image
* @entry: entry address of the relocated image
*/
struct efi_loaded_image_obj {
struct efi_object header;
efi_status_t exit_status;
+ efi_uintn_t *exit_data_size;
+ u16 **exit_data;
struct jmp_buf_data exit_jmp;
EFIAPI efi_status_t (*entry)(efi_handle_t image_handle,
struct efi_system_table *st);
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index a72cbe1559..6d2dc2dda3 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -2626,6 +2626,9 @@ efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle,
efi_is_direct_boot = false;
+ image_obj->exit_data_size = exit_data_size;
+ image_obj->exit_data = exit_data;
+
/* call the image! */
if (setjmp(&image_obj->exit_jmp)) {
/*
@@ -2669,6 +2672,41 @@ efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle,
return EFI_CALL(systab.boottime->exit(image_handle, ret, 0, NULL));
}
+/**
+ * efi_update_exit_data() - fill exit data parameters of StartImage()
+ *
+ * @image_obj image handle
+ * @exit_data_size size of the exit data buffer
+ * @exit_data buffer with data returned by UEFI payload
+ * Return: status code
+ */
+static efi_status_t efi_update_exit_data(struct efi_loaded_image_obj *image_obj,
+ efi_uintn_t exit_data_size,
+ u16 *exit_data)
+{
+ efi_status_t ret;
+
+ /*
+ * If exit_data is not provided to StartImage(), exit_data_size must be
+ * ignored.
+ */
+ if (!image_obj->exit_data)
+ return EFI_SUCCESS;
+ if (image_obj->exit_data_size)
+ *image_obj->exit_data_size = exit_data_size;
+ if (exit_data_size && exit_data) {
+ ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA,
+ exit_data_size,
+ (void **)image_obj->exit_data);
+ if (ret != EFI_SUCCESS)
+ return ret;
+ memcpy(*image_obj->exit_data, exit_data, exit_data_size);
+ } else {
+ image_obj->exit_data = NULL;
+ }
+ return EFI_SUCCESS;
+}
+
/**
* efi_exit() - leave an EFI application or driver
* @image_handle: handle of the application or driver that is exiting
@@ -2709,6 +2747,15 @@ static efi_status_t EFIAPI efi_exit(efi_handle_t image_handle,
if (ret != EFI_SUCCESS)
goto out;
+ /* Exit data is only foreseen in case of failure. */
+ if (exit_status != EFI_SUCCESS) {
+ ret = efi_update_exit_data(image_obj, exit_data_size,
+ exit_data);
+ /* Exiting has priority. Don't return error to caller. */
+ if (ret != EFI_SUCCESS)
+ EFI_PRINT("%s: out of memory\n", __func__);
+ }
+
/* Make sure entry/exit counts for EFI world cross-overs match */
EFI_EXIT(exit_status);
--
2.39.5