On 2025/1/17 7:34, Andrii Nakryiko wrote:
On Wed, Jan 15, 2025 at 2:00 AM Pu Lehui <pulehui@xxxxxxxxxxxxxxx> wrote:
From: Pu Lehui <pulehui@xxxxxxxxxx>
When redirecting the split BTF to the vmlinux base BTF, we need to mark
the distilled base struct/union members of split BTF structs/unions in
id_map with BTF_IS_EMBEDDED. This indicates that these types must match
both name and size later. So if a needed composite type, which is the
member of composite type in the split BTF, has a different size in the
base BTF we wish to relocate with, btf__relocate() should error out.
Signed-off-by: Pu Lehui <pulehui@xxxxxxxxxx>
---
v2: Add test about marking BTF_IS_EMBEDDED.
.../selftests/bpf/prog_tests/btf_distill.c | 72 +++++++++++++++++++
1 file changed, 72 insertions(+)
Nice test, thanks! Applied the series to bpf-next.
Curious, resilient split BTF is currently supported, shall we deprecate
MODULE_ALLOW_BTF_MISMATCH?
diff --git a/tools/testing/selftests/bpf/prog_tests/btf_distill.c b/tools/testing/selftests/bpf/prog_tests/btf_distill.c
index b72b966df77b..fb67ae195a73 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf_distill.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf_distill.c
@@ -601,6 +601,76 @@ static void test_distilled_endianness(void)
btf__free(base);
}
[...]
