FIES - Fault Injection for Evaluation of Software-based fault tolerance

FIES is a QEMU fault injection extension.

The following picture shows the main points, where FIES takes action during an QEMU binary translation:

The working principle of FIES is described in the following publications:

• A. Höller, G. Schönfelder, N. Kajtazovic, T. Rauter, and C. Kreiner, “FIES: A Fault Injection Framework for the Evaluation of Self-Tests for COTS-Based Safety-Critical Systems,” in 15th IEEE International Microprocessor Test and Verification Workshop (MTV), 2014, vol. 2015-April, pp. 105–110.
• A. Höller, G. Macher, T. Rauter, J. Iber, and C. Kreiner, “A Virtual Fault Injection Framework for Reliability-Aware Software Development,” in IEEE/IFIP International Conference on Dependable Systems and Networks Workshops (DSN-W), 2015, pp. 69 – 74.
• A. Höller, A. Krieg, T. Rauter, J. Iber, and C. Kreiner, “QEMU-Based Fault Injection for a System-Level Analysis of Software Countermeasures Against Fault Attacks,” in 18th Euromicro Conference on Digital System Design (DSD), 2015, pp. 530 – 533.

Building FIES

• Install required libraries: libffi, libiconv, gettext, python, pkg-config, glib, sdl, zlib, pixman, libfdt, libxml2 For detailed information about QEMU-required packages see http://wiki.qemu.org/Hosts/Linux . Additionally FIES requires libxml2.

To install dependencies on Ubuntu:

sudo apt install libffi6 libffi-dev libc6-dev gettext python pkg-config libsdl2-dev zlib1g-dev libpixman-1-dev libfdt-dev libxml2-dev
sudo apt install libsdl1.2debian libsdl-gfx1.2-5 libsdl-gfx1.2-dev libsdl-gfx1.2-doc libsdl-image1.2 libsdl-image1.2-dbg libsdl-image1.2-dev libsdl-mixer1.2 libsdl-mixer1.2-dbg libsdl-mixer1.2-dev libsdl-net1.2 libsdl-net1.2-dbg libsdl-net1.2-dev libsdl-sound1.2 libsdl-sound1.2-dev libsdl-ttf2.0-0 libsdl-ttf2.0-dev

• Configure and build FIES

CF=$(xml2-config --cflags)
LF=$(xml2-config --libs)
PP=$(which python2)
./configure --target-list=arm-softmmu --extra-cflags="$CF" --extra-ldflags="$LF" --python="$PP" --enable-sdl --disable-werror
cd pixman
./configure
cd ..
make

Using FIES

Example files

For illustration we created a simple hello-world app and exemplary fault libraries in the folder fies_sandbox

Compiling for FIES

Currently, FIES supports only ARM architectures. Thus, to compile an application that should be simulated with FIES compile it for ARM.

GCC example:

arm-none-eabi-gcc -marm *.c --specs=nosys.specs

Clang example:

clang -target arm -marm *.c 

If you use Code Sourcery use the following settings (C/C++ Build > Tool Settings)

• Board: QEMU ARM Simulator (VFP)
• Profile: Simulator
• Hosting: Hosted

Execute an Application without Fault Injection (for Golden Runs)

Start the application the same way as you start a normal QEMU emulation (see http://wiki.qemu.org/download/qemu-doc.html#pcsys_005fquickstart) Hint: to pass arguments use the -append flag

arm-softmmu/qemu-system-arm -semihosting -kernel <binary>

Application Profiling

Use the -profiling flag to record register and memory usage

Options:

• m profile memory usage
• r profile register usage

Results are stored in profiling_meory.txt or/and profiling_registers.txt

Example:

arm-softmmu/qemu-system-arm -semihosting -kernel <binary> -profiling rm

Start Fault Injection

Define Fault Library

Faults that should be injected are described in an XML file.

XML fault lib example:

<?xml version="1.0" encoding="UTF-8"?>
<injection>
	<fault>
		<id>1</id>
		<component>RAM</component>
		<target>MEMORY CELL</target>
		<mode>SF</mode>
		<trigger>ACCESS</trigger>
		<type>PERMANENT</type>
		<params> 
			<address>0x07FFFFDC</address>
			<mask>0xFF</mask>
			<set_bit>0xFF</set_bit>
		</params>
	</fault>
</injection>

XML Fields:

• <fault>: Defines start and end of fault description. Multiple faults are injected concurrently if multiple fault descriptions are provided.
• <id>: Defines fault ID
• <component>: CPU, RAM, or REGISTER
• <target>:
  • for CPU faults: INSTRUCTION DECODER, INSTRUCTION EXECUTION, or CONDITION FLAGS
  • for REGISTER faults: ADDRESS DECODER, REGISTER CELL
  • for RAM faults: ADDRESS DECODER, MEMORY CELL
• <mode>: Defines the fault mode
  • Condition flags: VF, ZF, CF, NF, QF
  • General fault modes: NEW VALUE, SF, BIT-FLIP
  • Operation-dependent static faults: TF0, TF1, WDF0, WDF1, IRF0, IRF1, DRDF0, DRDF1, RDF0, RDF1
  • Operation-dependent dynamic faults: RDF00, RDF01, RDF10, RDF11, IRF00, IRF01, IRF10, IRF11, DRDF00, DRDF01, DRDF10, DRDF11
  • Coupling faults: CFST00, CFST01, CFST10, CFST11, CFTR00, CFTR01, CFTR10, CFTR11, CFWD00, CFWD01, CFWD10, CFWD11, CFRD00, CFRD01, CFRD10, CFRD11, CFIR00, CFIR01, CFIR10, CFIR11, CFDR00, CFDR01, CFDR10, CFDR11, CFDS0W00, CFDS0W01, CFDS0W10, CFDS0W11, CFDSW00, CFDS1W01, CFDS1W10, CFDS1W11, CFDS0R00, CFDS0R01, CFDS0R10, CFDS1R11
• <trigger>: ACCESS, TIME, PC
• <type>: TRANSIENT, PERMANENT, INTERMITTEND
• <duration>: duration for intemittend and transient faults in ms (e.g. 10MS)
• <interval>: interval for intermittent faults in ms (e.g. 10MS)
• <params>: parameter descriptions to specify fault mode
  • <address>: register or memory address
  • <mask>: mask for the position where fault should be active (e.g. to inject fault in last bit 0x1), or new value definition in NEW VALUE mode
  • <cf_address>: coupling addrsss for coupling faults
  • <instruction>: instruction number that should be replaced for CPU INSTRUCTION DECODER faults
  • <set_bit>: mask to select if bits defined in <mask> should be set (e.g. 0x1 for SAF-1) or resetted (e.g. 0x0 for SAF-0). Aggressor-bit mask for intercoupling faults.

Execute software and inject fault

Use the -fi flag to give the fault library and start FIES with fault injection

arm-softmmu/qemu-system-arm -semihosting -kernel <binary> -fi <fault-lib.xml>

See fies.log for error messages