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_struct_types() 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. Changes in v2: 1. Patch 1: Refactored code to prevent copying existing logic. Instead of adding a new function () we modify the existing btf_dedup_struct_type() function to handle the BTF_KIND_TYPEDEF case. Calls to btf_hash_struct() and btf_shallow_equal_struct() are replaced with calls to functions that select btf_hash_struct() / btf_hash_typedef() based on the type. 2. Patch 2: Added tests v1: https://lore.kernel.org/lkml/[email protected]/ Paul Houssel (2): libbpf: fix BTF dedup to support recursive typedef definitions selftests/bpf: add BTF dedup tests for recursive typedef definitions tools/lib/bpf/btf.c | 59 +++++++++++++++---- tools/testing/selftests/bpf/prog_tests/btf.c | 61 ++++++++++++++++++++ 2 files changed, 110 insertions(+), 10 deletions(-) -- 2.51.0
