Re: [PATCH] efi_loader: Make DisconnectController follow the EFI spec

On 28.11.23 16:45, Ilias Apalodimas wrote:

commit 239d59a65e20 ("efi_loader: reconnect drivers on failure") tried to fix the UninstallProtocol interface which must reconnect any controllers it disconnected by calling ConnectController() in case of failure. However, the reconnect functionality was wired in efi_disconnect_all_drivers() instead of efi_uninstall_protocol().

As a result some SCT tests started failing. Specifically, BBTestOpenProtocolInterfaceTest333CheckPoint3() test

• Calls ConnectController for DriverImageHandle1

• Calls DisconnectController for DriverImageHandle1 which will disconnect everything apart from TestProtocol4. That will remain open on purpose.

• Calls ConnectController for DriverImageHandle2. TestProtocol4 which was explicitly preserved was installed wth BY_DRIVER attributes. The new protocol will call DisconnectController since its attributes are BY_DRIVER|EXCLUSIVE, but TestProtocol4 will not be removed. The test expects EFI_ACCESS_DENIED which works fine.

  The problem is that DisconnectController, will eventually call EFI_DRIVER_BINDING_PROTOCOL.Stop(). But on the aforementioned test this will call CloseProtocol -- the binding protocol is defined in 'DBindingDriver3.c' and the .Stop function uses CloseProtocol. If that close protocol call fails with EFI_NOT_FOUND, the current code will try to mistakenly reconnect all drivers and the subsequent tests that rely on the device being disconnected will fail.

Move the reconnection in efi_uninstall_protocol() were it belongs.

Fixes: commit 239d59a65e20 ("efi_loader: reconnect drivers on failure") Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org

---

Heinrich this is critical. Although it doesn't break anything on our normal use cases it does break the ACS testing for SystemReady-IR and I prefer landing it in -master before the 2024.01 release

Ok

lib/efi_loader/efi_boottime.c | 23 +++++------------------ 1 file changed, 5 insertions(+), 18 deletions(-)

diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c index 0b7579cb5af1..370eaee8ce1a 100644 --- a/lib/efi_loader/efi_boottime.c +++ b/lib/efi_loader/efi_boottime.c @@ -1339,7 +1339,7 @@ static efi_status_t efi_disconnect_all_drivers const efi_guid_t *protocol, efi_handle_t child_handle) {

• efi_uintn_t number_of_drivers, tmp;

• efi_uintn_t number_of_drivers; efi_handle_t *driver_handle_buffer; efi_status_t r, ret;

@@ -1350,31 +1350,17 @@ static efi_status_t efi_disconnect_all_drivers if (!number_of_drivers) return EFI_SUCCESS;

• tmp = number_of_drivers; while (number_of_drivers) {

• ret = EFI_CALL(efi_disconnect_controller(
  

• r = EFI_CALL(efi_disconnect_controller(
  	handle,
  	driver_handle_buffer[--number_of_drivers],
  	child_handle));
  

• if (ret != EFI_SUCCESS)
  

• 	goto reconnect;
  

• }
• free(driver_handle_buffer);
• return ret;

-reconnect:

• /* Reconnect all disconnected drivers */
• for (; number_of_drivers < tmp; number_of_drivers++) {

• r = EFI_CALL(efi_connect_controller(handle,
  

• 				    &driver_handle_buffer[number_of_drivers],
  

• 				    NULL, true));
  

  if (r != EFI_SUCCESS)

• 	EFI_PRINT("Failed to reconnect controller\n");
  

• 	ret = r;
  

  }

  free(driver_handle_buffer);

• return ret;

• return (ret != EFI_SUCCESS ? ret : EFI_SUCCESS);

This will always return ret. Did you want to return another value?

}

/** @@ -1409,6 +1395,7 @@ static efi_status_t efi_uninstall_protocol r = efi_disconnect_all_drivers(handle, protocol, NULL); if (r != EFI_SUCCESS) { r = EFI_ACCESS_DENIED;

• EFI_CALL(efi_connect_controller(handle, NULL, NULL, true));
  

Chapter "EFI_BOOT_SERVICES.UninstallProtocolInterface()" of the EFI specification says: " In addition, all of the drivers that were disconnected with the boot service DisconnectController() earlier, are reconnected with the boot service EFI_BOOT_SERVICES.ConnectController()." What makes you think that ConnectController() should be called with DriverImageHandle = NULL? I cannot derive this from the specification.

EDK2's CoreDisconnectControllersUsingProtocolInterface() does so. But shouldn't such behavior be defined in the specification?

We have 4 places where we use EFI_CALL to call efi_connect_controller. Should we provide an internal function?

Best regards

Heinrich

goto out;

} /* Close protocol */ -- 2.37.2