Files
xen/tools/fuzz
Tamas K Lengyel 51e1c041f5 oss-fuzz: Fix coverage runtime error
The oss-fuzz infrastructure collects runtime coverage information for debugging
and fuzzing evaluation. Currently it appears broken due to missing C files.
This is because the fuzzer's Makefile only symlinks the C files from various
locations in the Xen source tree into the build folder. These symlinks however
are gone as oss-fuzz uses separate docker containers for the build and for the
run.

Update the oss-fuzz build script to copy the required C files into the
build folder to fix this oss-fuzz specific issue.

Signed-off-by: Tamas K Lengyel <tamas@tklengyel.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
2024-08-28 19:43:32 +01:00
..
2022-07-12 08:36:37 +02:00
2017-07-28 17:47:42 +01:00
2017-01-25 10:04:31 +00:00

# OVERVIEW

This directory provides fuzzing targets to be run inside Google
oss-fuzz infrastructure.

See also https://github.com/google/oss-fuzz.

# HOW IT WORKS

We need to provide the source code and the rune to produce objects or
archives (artefacts) from source code. These items ideally should live
inside xen.git so that they can be kept up to date.

The artefacts contain all the code we wish to fuzz and a function
called LLVMFuzzerTestOneInput. LLVMFuzzerTestOneInput is the entry
point to the code we wish to fuzz. Note that we don't produce
executable programs because we don't have libFuzzEngine
locally. libFuzzEngine is maintained by oss-fuzz.

We also provide build script to oss-fuzz. The build script will
inherit the correct compiler settings and be run in a pre-setup
environment, which has libFuzzEngine installed. The build script is
responsible for calling the correct Xen build rune to produce the
artefacts, then link them against libFuzzEngine to produce
executables, which will run in oss-fuzz infrastructure.

Please refer to official oss-fuzz documents for the most up-to-date
descriptions for all moving parts.

# HOW TO IMPROVE THE FUZZING TARGETS

Feel free to modify each fuzzing targets at will. Make sure they build
by invoking make as you would build tools.

To actually test the new code, you would need to run the target in
standalone mode, please refer to oss-fuzz documents on how to do that.

It is highly recommended that you run the new target for a while to
weed out error in plumbing code to avoid false positives.