This repository has been archived by the owner on Nov 1, 2023. It is now read-only.
Fix MSVC Libfuzzer coverage reporting #324
Merged
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 PR fixes two issues: - First, in MSVC compiled binaries both the LLVM _and_ MSVC symbols are present, but only the MSVC symbols have correct values. For example: ``` 0:000> cdb: Reading initial command '.scriptload DumpCountersOld.js ; !dumpcounters "cov" ; q' JavaScript script successfully loaded from 'DumpCountersOld.js' [+] not disabling sympath INFO: Seed: 58715679 INFO: Loaded 1 modules (3968 inline 8-bit counters): 3968 [00007FF70DB4B000, 00007FF70DB4BF80), # XXX Note xxx.exe: Running 1 inputs 1 time(s) each. Running: inp [+] processing xxx.exe [+] using LLVM 10 symbols - 0x7ff70db72b00:0x7ff70db72b08 # XXX These are wrong ``` This means the order we search for the coverage symbols is important. - Secondly, this enables support for MSVC 8bit counter coverage.
bmc-msft
reviewed
Nov 18, 2020
bmc-msft
suggested changes
Nov 18, 2020
bmc-msft
approved these changes
Nov 18, 2020
|
Performing integration tests with existing samples. |
|
Hello @bmc-msft! Because this pull request has the Do note that I've been instructed to only help merge pull requests of this repository that have been opened for at least 18 hours, a condition that will be fulfilled in about 5 hours 20 minutes. No worries though, I will be back when the time is right! 😉 p.s. you can customize the way I help with merging this pull request, such as holding this pull request until a specific person approves. Simply @mention me (
|
ghost
merged commit 
ghost
locked as resolved and limited conversation to collaborators
This pull request was closed.
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
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.
This PR fixes two issues:
present, but only the MSVC symbols have correct values. For example:
This means the order we search for the coverage symbols is important.
Validation Steps Performed
Running any recent MSVC compiled libfuzzer target should fail to actually collect coverage, instead just returning the 8 null bytes described in the linked issue.