[PATCH 4/5] efi_loader: fix the return codes of UninstallProtocol

[Heinrich Schuchardt]

On 6/15/23 16:39, Ilias Apalodimas wrote:
> Up to now we did not check the return value of DisconnectController.
> A previous patch is fixing that taking into account what happened during
> the controller disconnect.  But that check takes place before our code
> is trying to figure out if the interface exists to begin with.  In case a
> driver is not allowed to unbind -- e.g returning EFI_DEVICE_ERROR, we
> will end up returning that error instead of EFI_NOT_FOUND.
>
> Add an extra check on the top of the function to make sure the protocol
> interface exists before trying to disconnect any drivers
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>

Reviewed-by: Heinrich Schuchardt <xypron.glpk at gmx.de>

> ---
>   lib/efi_loader/efi_boottime.c | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> index b148824c7ec5..d6d52d4bbac8 100644
> --- a/lib/efi_loader/efi_boottime.c
> +++ b/lib/efi_loader/efi_boottime.c
> @@ -1373,6 +1373,8 @@ static efi_status_t efi_uninstall_protocol
>   	r = efi_search_protocol(handle, protocol, &handler);
>   	if (r != EFI_SUCCESS)
>   		goto out;
> +	if (handler->protocol_interface != protocol_interface)
> +		return EFI_NOT_FOUND;
>   	/* Disconnect controllers */
>   	r = efi_disconnect_all_drivers(handle, NULL, NULL);
>   	if (r != EFI_SUCCESS) {