Re: [PATCH 2/4 v2] efi_loader: check the status of disconnected drivers

[Heinrich Schuchardt]

Am 20. Juni 2023 08:19:29 MESZ schrieb Ilias Apalodimas <ilias.apalodimas at linaro.org>:
>efi_uninstall_protocol() calls efi_disconnect_all_drivers() but never
>checks the return value.  Instead it tries to identify protocols that
>are still open after closing the ones that were opened with
>EFI_OPEN_PROTOCOL_BY_HANDLE_PROTOCOL, EFI_OPEN_PROTOCOL_GET_PROTOCOL
>and EFI_OPEN_PROTOCOL_TEST_PROTOCOL.
>
>Instead of doing that,  check the return value early and exit if
>disconnecting the drivers failed.  Also reconnect all the drivers of
>a handle if protocols are still found on the handle after disconnecting
>controllers and closing the remaining protocols.

We talk about a single protocol but possibly multiple open prototocol information records.

Othrwise looks good.

Best regards

Heinrich

>
>While at it fix a memory leak and properly free the opened protocol
>information when closing a protocol.
>
>Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
>---
> lib/efi_loader/efi_boottime.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
>diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
>index d44562d8f4e0..bfcd913dfad9 100644
>--- a/lib/efi_loader/efi_boottime.c
>+++ b/lib/efi_loader/efi_boottime.c
>@@ -1374,17 +1374,23 @@ static efi_status_t efi_uninstall_protocol
> 	if (r != EFI_SUCCESS)
> 		goto out;
> 	/* Disconnect controllers */
>-	efi_disconnect_all_drivers(efiobj, protocol, NULL);
>+	r = efi_disconnect_all_drivers(efiobj, protocol, NULL);
>+	if (r != EFI_SUCCESS) {
>+		r = EFI_ACCESS_DENIED;
>+		goto out;
>+	}
> 	/* Close protocol */
> 	list_for_each_entry_safe(item, pos, &handler->open_infos, link) {
> 		if (item->info.attributes ==
> 			EFI_OPEN_PROTOCOL_BY_HANDLE_PROTOCOL ||
> 		    item->info.attributes == EFI_OPEN_PROTOCOL_GET_PROTOCOL ||
> 		    item->info.attributes == EFI_OPEN_PROTOCOL_TEST_PROTOCOL)
>-			list_del(&item->link);
>+			efi_delete_open_info(item);
> 	}
>+	/* if agents didn't close the protocols properly */
> 	if (!list_empty(&handler->open_infos)) {
> 		r =  EFI_ACCESS_DENIED;
>+		EFI_CALL(efi_connect_controller(handle, NULL, NULL, true));
> 		goto out;
> 	}
> 	r = efi_remove_protocol(handle, protocol, protocol_interface);
>--
>2.40.1
>