fuzz: simplify fuzzers dependencies in CIFuzz #1896

IvanNardi · 2023-03-02T14:33:56Z

CIFuzz (based on oss-fuzz) is the GitHub action/CI job that runs fuzz
targets on pull requests. It only runs the fuzzers affected by a pull
request/commit. Otherwise it will divide up the allotted fuzzing time
among all fuzzers in the project.
Since:

we have more than 20 fuzzers and most of them use the custom memory
allocation functions (to force allocation failures) even if they are not
strictly about DPI stuff;
we need to keep fuzzing time relatively small (to avoid waiting for the CI
results for a long time)

it is important that fuzzers dependencies (which are based on files
changed by the single commit/PR) are as small as possible.

Bottom line: move all the low-level allocation callbacks to a dedicated
file; this way most of the fuzzers don't depend anymore on ndpi_main.c
file (which is touched by every commit/PR).

The goal is to have only the "most important" fuzzers running during (most
of) the CI.

utoni

I do not know what the intention of those flow memory wrappers were in the first place. But in my imagination, it could be useful e.g. for fixed size memory pools.

I am not sure if this feature is used by developers. But I think it has it's justification.

IvanNardi · 2023-03-13T12:10:18Z

I do not know what the intention of those flow memory wrappers were in the first place. But in my imagination, it could be useful e.g. for fixed size memory pools.

I am not sure if this feature is used by developers. But I think it has it's justification.

Ok, I'll push a new version restoring the flow wrappers

CIFuzz (based on oss-fuzz) is the GitHub action/CI job that runs fuzz targets on pull requests. It only runs the fuzzers affected by a pull request/commit. Otherwise it will divide up the allotted fuzzing time among all fuzzers in the project. Since: * we have more than 20 fuzzers and most of them use the custom memory allocation functions (to force allocation failures) even if they are not strictly about DPI stuff; * we need to keep fuzzing time relatively small (to avoid waiting the CI results for a long time) it is important that fuzzers dependencies (which are based on *files* changed by the single commit/PR) are as small as possible. Bottom line: move all the low-level allocation callbacks to a dedicated file; this way most of the fuzzers don't depend anymore on `ndpi_main.c` file (which is touched by ever commit/PR). The goal is to have only the "most important" fuzzers running during (most of) the CI.