Re: [PATCH v4 1/2] libbpf: fix BTF dedup to support recursive typedef definitions

[Eduard Zingerman]

On Thu, 2025-11-13 at 13:39 +0100, Paul Houssel wrote:
> Handle recursive typedefs in BTF deduplication
> 
> Pahole fails to encode BTF for some Go projects (e.g. Kubernetes and
> Podman) due to recursive type definitions that create reference loops
> not representable in C. These recursive typedefs trigger a failure in
> the BTF deduplication algorithm.
> 
> This patch extends btf_dedup_ref_type() to properly handle potential
> recursion for BTF_KIND_TYPEDEF, similar to how recursion is already
> handled for BTF_KIND_STRUCT. This allows pahole to successfully
> generate BTF for Go binaries using recursive types without impacting
> existing C-based workflows.
> 
> Co-developed-by: Martin Horth <martin.horth@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Martin Horth <martin.horth@xxxxxxxxxxxxxxxxxxx>
> Co-developed-by: Ouail Derghal <ouail.derghal@xxxxxxxxxxxxxxxxx>
> Signed-off-by: Ouail Derghal <ouail.derghal@xxxxxxxxxxxxxxxxx>
> Co-developed-by: Guilhem Jazeron <guilhem.jazeron@xxxxxxxx>
> Signed-off-by: Guilhem Jazeron <guilhem.jazeron@xxxxxxxx>
> Co-developed-by: Ludovic Paillat <ludovic.paillat@xxxxxxxx>
> Signed-off-by: Ludovic Paillat <ludovic.paillat@xxxxxxxx>
> Co-developed-by: Robin Theveniaut <robin.theveniaut@xxxxxxx>
> Signed-off-by: Robin Theveniaut <robin.theveniaut@xxxxxxx>
> Suggested-by: Tristan d'Audibert <tristan.daudibert@xxxxxxxxx>
> Signed-off-by: Paul Houssel <paul.houssel@xxxxxxxxxx>
> 
> ---

Acked-by: Eduard Zingerman <eddyz87@xxxxxxxxx>

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