Re: [stos, again] Re: CVS commit: src/sys/arch/amd64

[Kamil Rytarowski <kamil%netbsd.org@localhost>]

On 03.06.2020 01:49, Andrew Doran wrote:
> On the assembly thing recall that recently you expressed a desire to remove
> all of the amd64 assembly string functions from libc because of sanitizers -
> I invested my time to do up a little demo to try and show you why that's not
> a good idea:
> 
> 	http://mail-index.netbsd.org/port-amd64/2020/04/19/msg003226.html

Please note that interceptors for string functions are not just some
extra burden, but also very useful approach to feedback a fuzzer through
additional coverage.

At least libFuzzer and honggfuzz wrap many kinds of string functions and
use it for fuzzing. We should add a special mode in KCOV to feedback
userland (syzkaller) with traces from string functions.

https://github.com/google/honggfuzz/blob/bbb476eec95ad927d6d7d3d367d2b3e38eed3569/libhfuzz/memorycmp.c#L24