Am 24.01.2018 um 01:05 schrieb Heinrich Schuchardt xypron.glpk@gmx.de:
On 01/24/2018 12:31 AM, Alexander Graf wrote:
On 23.01.18 23:46, Heinrich Schuchardt wrote: 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@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));
Just use the systab here, like we do in efi_do_enter().
No, efi_do_enter passes image_handle to efi_exit().
The UEFI API requires the image handle. It is the same image handle that the application would pass when calling Exit.
efi_exit() uses the handle as pointer to the loaded image information.
I mean use the systab to get to efi_exit instead of shuffling code around :). It‘s what we do in bootefi as well.
Alex