Re: [PATCH bpf-next] libbpf: fix -Wformat warnings from format/argument type mismatches

[Quentin Monnet <qmo@kernel.org>]

2026-06-30 11:32 UTC-0700 ~ Andrii Nakryiko <andrii.nakryiko@gmail.com>
> On Fri, Jun 26, 2026 at 6:30 AM <patchwork-bot+netdevbpf@kernel.org> wrote:
>>
>> Hello:
>>
>> This patch was applied to bpf/bpf-next.git (master)
>> by Alexei Starovoitov <ast@kernel.org>:
>>
>> On Wed, 24 Jun 2026 13:49:46 -0700 you wrote:
>>> Building libbpf with -Wall (as happens via bpftool's bootstrap build)
>>> surfaces ~120 -Wformat warnings where pr_warn/pr_debug format specifiers
>>> don't match their argument types: %d for __u32/Elf64_Word, %u for signed
>>> ints, %zd for size_t, %ld for unsigned long, and %x/%lx/%llx applied to
>>> signed values.
>>>
>>> Match each specifier to its argument's type where a correctly-signed
>>> specifier exists (%d<->%u, %ld->%lu, %zd->%zu). For hex conversions,
>>> which have no signed form, cast the argument instead (%x->(unsigned),
>>> %lx->(unsigned long), %llx->(unsigned long long)). No functional change.
>>>
>>> [...]
>>
>> Here is the summary with links:
>>   - [bpf-next] libbpf: fix -Wformat warnings from format/argument type mismatches
>>     https://git.kernel.org/bpf/bpf-next/c/df3153758ddb
>>
> 
> Quentin,
> 
> I synced these changes to libbpf's Github mirror. Can you please
> update bpftool mirror's libbpf reference to include this change, so
> that I can fix these noisy warnings for wprof? Thanks!


Hi Andrii, I just synced it, thank you.

Quentin