Re: [PATCH bpf-next v7 6/9] selftests/bpf: Add arena ASAN runtime to libarena

["Emil Tsalapatis" <emil@etsalapatis.com>]

On Sun Apr 12, 2026 at 2:28 PM EDT, bot+bpf-ci wrote:
>> diff --git a/tools/testing/selftests/bpf/libarena/src/asan.bpf.c b/tools/testing/selftests/bpf/libarena/src/asan.bpf.c
>> new file mode 100644
>> index 000000000000..fff12ff50f26
>> --- /dev/null
>> +++ b/tools/testing/selftests/bpf/libarena/src/asan.bpf.c
>
> [ ... ]
>
>> +SEC("syscall")
>> +__weak __noasan int asan_init(struct asan_init_args *args)
>> +{
>> +	u64 globals_pages = args->arena_globals_pages;
>> +	u64 all_pages = args->arena_all_pages;
>> +	u64 shadow_map, shadow_pgoff;
>> +	u64 shadow_pages;
>> +
>> +	if (asan_inited)
>> +		return 0;
>> +
>> +	/*
>> +	 * Round up the shadow map size to the nearest page.
>> +	 */
>> +	shadow_pages = all_pages >> ASAN_SHADOW_SHIFT;
>> +	if ((all_pages & ((1 << ASAN_SHADOW_SHIFT) - 1)))
>> +		shadow_pages += 1;
>> +
>> +	/*
>> +	 * Make sure the numbers provided by userspace are sane.
>> +	 */
>
> Alexei Starovoitov flagged this comment as unhelpful in v4 review.
> The validation checks below with their error messages are
> self-documenting. Was the intent to remove this comment or
> replace it with something more descriptive?
>
> https://lore.kernel.org/bpf/CAADnVQLHFZE3AFzP3gtZKvcaX+3hbp3pCw3JLqEtpdoQ+OUf7g@mail.gmail.com/

Missed this during the comment removal pass, holding off on updating
for now as this is relatively minor.

>
>> +	if (all_pages > (1ULL << 32) / __PAGE_SIZE) {
>> +		arena_stderr("error: arena size %lx too large", all_pages);
>> +		return -EINVAL;
>> +	}
>
> [ ... ]
>
>
> ---
> AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
> See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md
>
> CI run summary: https://github.com/kernel-patches/bpf/actions/runs/24313021445