Added experimental Compcov/LAF support for the Bochs backend #186
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This was referenced Oct 12, 2023
|
Damn, this is looking awesome 😳🔥Thank you for sending this in! I am currently traveling so it'll take me more time than usual to review this, bear with me 🙏 Cheers |
![github-advanced-security[bot]](https://avatars.githubusercontent.com/in/57789?s=60&v=4){kind=small}
| LCID Locale, DWORD dwCmpFlags, PCNZWCH lpString1, int cchCount1, | ||
| PCNZWCH lpString2, int cchCount) = CompareStringW; | ||
| if (compare_string_w_ptr(LOCALE_USER_DEFAULT, 0, str5, sizeof(str5) / 2 - 1, | ||
| (const wchar_t *)buffer, |
Check failure
Code scanning / CodeQL
Cast from char* to wchar_t* High
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Hi!
This summer I've worked on adding LAF/Compcov support for WTF. This pull-request is the essence of this experiment. I tried to make the code as "production"-ready as possible but I'm sure there is still a long way to go. I'm sending this PR because at the moment I don't have any time to work on it any further.
LAF/Compcov mode allows to solve some basic CMP-related fuzz-blockers by splitting them into multiple comparisons of smaller sizes. With the proposed implementation of the LAF/Compcov mode, WTF was able to solve all the challenges from this "benchmark": fuzzy_goat.cc and crash the program:
An alternative implementations of this technique can be found in the qemuafl's source code: qemuafl/cpu-translate.h
I did some basic evaluation of the proposed approach (only on one target - rizin), and it kinda works but honestly speaking I was expecting a little bit more :) (maybe if it's tested on other targets it will show better results but who knows).
All the experimental-evaluation stuff can be found in the
./scripts/folder. The experiment I've conducted consisted of running a bunch of WTF instances with and w/o the LAF/Compcov mode. To be precise, I had 2 instances running with LAF/Compcov support (Bochs backend), and 6 instances running on the KVM backend. The experiment was repeated 5 times each one was running for 6 hours on a PC with Ubuntu, and Intel I5 processor (don't remember the exact model).Coverage mean:
Execs/sec:
Corpus size:
The error bands here show +-1 std from the mean.
The conclusion I get from this evaluation is that it's not possible to say whether the LAF/Compcov mode really helps to fuzz Rizin, however it might show drastically better results on other targets.
Changes summary:
--laf,--compcov,--laf-allowed-ranges)gen_coverage_*scripts