[PATCH bpf-next 08/13] bpftool gen: embed loader prog BTF in the lskel header
From: KP Singh <kpsingh@kernel.org>
Date: 2026-05-22 02:32:53
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [tooling] (bpftool), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Quentin Monnet, Linus Torvalds
Extend the signed lskel codegen to include the loader prog BTF in the generated header and the PKCS#7 signature scope. The loader needs this BTF at load time so the kernel can resolve kfunc calls by name. Lskels generated without -S are unchanged; the new codegen is gated on opts.btf_sz. Signed-off-by: KP Singh <kpsingh@kernel.org> --- tools/bpf/bpftool/gen.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)
diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index 2f9e10752e28..95dba5c53ef4 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c@@ -793,6 +793,8 @@ static int gen_trace(struct bpf_object *obj, const char *obj_name, const char *h if (sign_progs) { sopts.insns = opts.insns; sopts.insns_sz = opts.insns_sz; + sopts.btf = opts.btf; + sopts.btf_sz = opts.btf_sz; sopts.excl_prog_hash = prog_sha; sopts.excl_prog_hash_sz = sizeof(prog_sha); sopts.signature = sig_buf;
@@ -822,6 +824,17 @@ static int gen_trace(struct bpf_object *obj, const char *obj_name, const char *h \n\ \";\n"); + if (opts.btf_sz) { + codegen("\ + \n\ + static const char opts_btf[] __attribute__((__aligned__(8))) = \"\\\n\ + "); + print_hex(opts.btf, opts.btf_sz); + codegen("\ + \n\ + \";\n"); + } + codegen("\ \n\ opts.signature = (void *)opts_sig; \n\
@@ -830,6 +843,14 @@ static int gen_trace(struct bpf_object *obj, const char *obj_name, const char *h opts.excl_prog_hash_sz = sizeof(opts_excl_hash) - 1; \n\ opts.keyring_id = skel->keyring_id; \n\ "); + + if (opts.btf_sz) { + codegen("\ + \n\ + opts.btf = (void *)opts_btf; \n\ + opts.btf_sz = sizeof(opts_btf) - 1; \n\ + "); + } } codegen("\
--
2.53.0