Qemu tmin

[forky2]

Description

Single-threaded version of a QEMU testcase minizer. Submitting for interested parties.

Possibly working on a multi-threaded modification, but I would like to propose that both single-threaded and multi-threaded version could be kept in the codebase as a tutorial to others. I've tried to be quite detailed in my comments.

Checklist

• [*] I have run ./scripts/precommit.sh and addressed all comments

[tokatoka]

Can you add your fuzzer to this list
https://github.com/AFLplusplus/LibAFL/blob/main/.github/workflows/build_and_test.yml#L388

[tokatoka]

Should this supercede your pending PR? @WorksButNotTested

[tokatoka]

As I said this should not be run with a normal executor
Romain will replace forkexecutor with forkserver in #3114
I think we should wait it to be merged

[forky2]

Yep, happy to wait for that to be merged. I'll keep going with this as best I can until that PR is merged and then deal with replacing it. Presumably the same will need to be done for other fuzzers I'm not touching, like qemu_cmin.

[forky2]

The fork version of my code doesn't work anyway, so rather than fix it, I'll wait for this new ForkServer to drop and refactor against that.

[WorksButNotTested]

Check out this for an example of how you can have a single crate create multiple binaries. Then you can put any common code in a single file and reference it from either fuzzer. Alternatively, you can just add a command line argument for '--cores' like the other qemu fuzzers.

LibAFL/libafl_qemu/librasan/fuzz/Cargo.toml

Line 29 in fb0848e

[[bin]]

[WorksButNotTested]

Should this supercede your pending PR? @WorksButNotTested

Absolutely. I didn't get time to finish it. I hope it was a useful starting point though.

[WorksButNotTested]

Looks like a little format error here...
https://github.com/AFLplusplus/LibAFL/actions/runs/14216906751/job/39835637242?pr=3118
Running this guy should fix it...
https://github.com/AFLplusplus/LibAFL/blob/main/scripts/fmt_all.sh

[forky2]

Thanks all; I've got more pressing things to do today but I'll take all comments on board on Monday. Yes @WorksButNotTested it was useful thanks!

[forky2]

Looks like a little format error here... https://github.com/AFLplusplus/LibAFL/actions/runs/14216906751/job/39835637242?pr=3118 Running this guy should fix it... https://github.com/AFLplusplus/LibAFL/blob/main/scripts/fmt_all.sh

Whatever that thing toplo is whinging about, neither ./scripts/precommit.sh nor ./scripts/fmt_all.sh report. I did a costly container rebuild to see if it was a new nightly feature but no change.

[domenukk]

Looks like a little format error here... https://github.com/AFLplusplus/LibAFL/actions/runs/14216906751/job/39835637242?pr=3118 Running this guy should fix it... https://github.com/AFLplusplus/LibAFL/blob/main/scripts/fmt_all.sh

Whatever that thing toplo is whinging about, neither ./scripts/precommit.sh nor ./scripts/fmt_all.sh report. I did a costly container rebuild to see if it was a new nightly feature but no change.

install taplo, then run taplo format.
This is added to fmt_all in #3099 but it hasn't landed yet

[forky2]

install taplo, then run taplo format.

How does one install taplo? I've tried:

• cargo install taplo ("there is nothing to install in taplo v0.13.2, because it has no binaries")
• cargo add taplo (no error, but still no taplo binary in path), apt install taplo (doesn't exist)
• rustup component add taplo ("toolchain 'nightly-x86_64-unknown-linux-gnu' does not contain component 'taplo' for target 'x86_64-unknown-linux-gnu'; did you mean 'cargo'?")

Never mind; I found the crate: taplo-cli

[forky2]

I've done the parallel version as best I can. Waiting on ForkServer completion before finishing the "fork" version. Then I'll look at merging the single and multiple core versions as @WorksButNotTested suggested.