[U-Boot] [PATCH 1/1] efi_loader: always call Exit after an image returns.
Heinrich Schuchardt
xypron.glpk at gmx.de
Tue Jan 23 22:46:39 UTC 2018
If an application or driver started via StartImage returns without
calling Exit, StartImage has to call Exit. This is mandated by the
UEFI spec and we do the same in efi_do_enter().
The patch looks bigger than it is. To avoid a forward declaration function
efi_exit() was moved up. Only one (void*) was replaced by (void *).
The only real change is in efi_start_image().
Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
---
Without this patch on Ubuntu 16.04 a crash could be observed in
efi_selftest_startimage_return.c. With the patch it is gone.
But this could be coincidence.
---
lib/efi_loader/efi_boottime.c | 99 ++++++++++++++++++++++---------------------
1 file changed, 51 insertions(+), 48 deletions(-)
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 0ac5b44..62a24bf 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -1519,6 +1519,54 @@ failure:
}
/*
+ * Leave an EFI application or driver.
+ *
+ * This function implements the Exit service.
+ * See the Unified Extensible Firmware Interface (UEFI) specification
+ * for details.
+ *
+ * @image_handle handle of the application or driver that is exiting
+ * @exit_status status code
+ * @exit_data_size size of the buffer in bytes
+ * @exit_data buffer with data describing an error
+ * @return status code
+ */
+static efi_status_t EFIAPI efi_exit(efi_handle_t image_handle,
+ efi_status_t exit_status, unsigned long exit_data_size,
+ int16_t *exit_data)
+{
+ /*
+ * We require that the handle points to the original loaded
+ * image protocol interface.
+ *
+ * For getting the longjmp address this is safer than locating
+ * the protocol because the protocol may have been reinstalled
+ * pointing to another memory location.
+ *
+ * TODO: We should call the unload procedure of the loaded
+ * image protocol.
+ */
+ struct efi_loaded_image *loaded_image_info = (void *)image_handle;
+
+ EFI_ENTRY("%p, %ld, %ld, %p", image_handle, exit_status,
+ exit_data_size, exit_data);
+
+ /* Make sure entry/exit counts for EFI world cross-overs match */
+ EFI_EXIT(exit_status);
+
+ /*
+ * But longjmp out with the U-Boot gd, not the application's, as
+ * the other end is a setjmp call inside EFI context.
+ */
+ efi_restore_gd();
+
+ loaded_image_info->exit_status = exit_status;
+ longjmp(&loaded_image_info->exit_jmp, 1);
+
+ panic("EFI application exited");
+}
+
+/*
* Call the entry point of an image.
*
* This function implements the StartImage service.
@@ -1575,59 +1623,14 @@ static efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle,
ret = EFI_CALL(entry(image_handle, &systab));
+ /* Clean up the image */
+ ret = EFI_CALL(efi_exit(image_handle, ret, 0, NULL));
+
/* Should usually never get here */
return EFI_EXIT(ret);
}
/*
- * Leave an EFI application or driver.
- *
- * This function implements the Exit service.
- * See the Unified Extensible Firmware Interface (UEFI) specification
- * for details.
- *
- * @image_handle handle of the application or driver that is exiting
- * @exit_status status code
- * @exit_data_size size of the buffer in bytes
- * @exit_data buffer with data describing an error
- * @return status code
- */
-static efi_status_t EFIAPI efi_exit(efi_handle_t image_handle,
- efi_status_t exit_status, unsigned long exit_data_size,
- int16_t *exit_data)
-{
- /*
- * We require that the handle points to the original loaded
- * image protocol interface.
- *
- * For getting the longjmp address this is safer than locating
- * the protocol because the protocol may have been reinstalled
- * pointing to another memory location.
- *
- * TODO: We should call the unload procedure of the loaded
- * image protocol.
- */
- struct efi_loaded_image *loaded_image_info = (void*)image_handle;
-
- EFI_ENTRY("%p, %ld, %ld, %p", image_handle, exit_status,
- exit_data_size, exit_data);
-
- /* Make sure entry/exit counts for EFI world cross-overs match */
- EFI_EXIT(exit_status);
-
- /*
- * But longjmp out with the U-Boot gd, not the application's, as
- * the other end is a setjmp call inside EFI context.
- */
- efi_restore_gd();
-
- loaded_image_info->exit_status = exit_status;
- longjmp(&loaded_image_info->exit_jmp, 1);
-
- panic("EFI application exited");
-}
-
-/*
* Unload an EFI image.
*
* This function implements the UnloadImage service.
--
2.7.4
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