Re: [PATCH bpf-next v1 00/14] selftests/bpf: Fixes for userspace ASAN

[Ihor Solodrai]

On 2/13/26 10:09 AM, Eduard Zingerman wrote:
> On Fri, 2026-02-13 at 09:56 -0800, Ihor Solodrai wrote:
>> On 2/12/26 3:26 PM, Eduard Zingerman wrote:
>>> On Wed, 2026-02-11 at 17:13 -0800, Ihor Solodrai wrote:
>>>> This series includes various fixes aiming to enable test_progs run
>>>> with userspace address sanitizer on BPF CI.
>>>>
>>>> The first patch fixes the selftests/bpf/test_progs build with:
>>>>
>>>>     SAN_CFLAGS="-fsanitize=address -fno-omit-frame-pointer"
>>>>
>>>> The subsequent patches fix bugs reported by the address sanitizer on
>>>> attempt to run the tests.
>>>>
>>>> The series is a pre-requisite for enabling "test_progs with ASAN"
>>>> workflow on BPF CI.
>>>
>>> Also, do we want to have ASAN enabled by default?
>>
>> I don't think so. At least not right away.
>>
>>> If it would be enabled for CI, people will need to deal with local
>>> configuration anyway. It might make sense to put the default flags in
>>> to save everyone the trouble of figuring out which flags CI uses.
>>> Wdyt?
>>
>> WIP CI changes add an *additional* test job, that builds only
>> test_progs default flavor with ASAN and runs it. Previous test jobs,
>> built with -static, are still there as usual.
>>
>> There are tests that don't play well with ASAN such as BPF arena
>> tests, and some tests may be much slower when ASAN is enabled.
>> We still want to run them on CI.
> 
> Fair enough.
> 
>> I don't see why we should pick between asan everywhere or
>> nowhere. At the very least, CI should make sure selftests can build
>> successfully without the asan flags.
>>
>> Additional job will catch most of bugs of the sort covered in this
>> series, and that is good enough I think.
> 
> My main concern is that when this fails on CI I will have to dig
> through CI config to recover exact SAN_CFLAGS used. If not enabled by
> default I'd still like to have a single knob like 'ASAN=t'.

I kinda have a switch like that [1]:

	if [[ -n "${SELFTESTS_BPF_ASAN:-}" ]]; then
		SELF_OPTS+=(SAN_CFLAGS="-fsanitize=address -fno-omit-frame-pointer")
	[...]

Any ideas how to make this obvious in CI logs?
I could set -x in the script executing the make, but it may be noisy still.

[1] https://github.com/libbpf/ci/blob/selftests-asan/build-selftests/build_selftests.sh#L50-L51