TEE-Watchdog: Mitigating Unauthorized Activities within Trusted Execution Environments in ARM-Based Low-Power IoT Devices

Algorithm 4

Creating a log entry of access violation into log file

	Input:             ⊳ Application ID causing the access violation
	Output:
	Procedure Log_Violation(ActiveApp)
	Initialize       ⊳ A datastructure representing Log File entry is initialized with null values
	if bit 7 of MMFSR = = 1 then               ⊳ The MMFAR holds a valid fault address
	⊳ Violating application
	MMFAR         ⊳ Violated peripheral address
	if bit 0 of MMFSR = = 1 then
	XN              ⊳ Code execution attempt
	else if bit 1 of MMFSR = = 1 then
	RW              ⊳ Read or write attempt
	else if bit 3 ofMMFSR = = 1 then
	ER            ⊳ Access violation due to exception return
	else if bit 4 ofMMFSR = = 1 then
	EE             ⊳ Access violation due to exception entry
	else
	UE                       ⊳ Unknown fault
	end
	Write to Secure Storage
	⊳ The procedure is successful
	else
	;
	⊳ MMFAR does not contain a valid address and is not added to Log File
	end
	return
	End Procedure