libbpf: fix feature detectors when using token_fd

Adjust `union bpf_attr` size passed to kernel in two feature-detecting
functions to take into account prog_token_fd field.

Libbpf is avoiding memset()'ing entire `union bpf_attr` by only using
minimal set of bpf_attr's fields. Two places have been missed when
wiring BPF token support in libbpf's feature detection logic.

Fix them trivially.

Fixes: f3dcee938f48 ("libbpf: Wire up token_fd into feature probing logic")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240513180804.403775-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 466a29d8012498a9adb22db9c852f6557569efee..2a4c71501a17db9de73922bd001b713a2319d051 100644 (file)
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -105,7 +105,7 @@ int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts)
  */
 int probe_memcg_account(int token_fd)
 {
-       const size_t attr_sz = offsetofend(union bpf_attr, attach_btf_obj_fd);
+       const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd);
        struct bpf_insn insns[] = {
                BPF_EMIT_CALL(BPF_FUNC_ktime_get_coarse_ns),
                BPF_EXIT_INSN(),

diff --git a/tools/lib/bpf/features.c b/tools/lib/bpf/features.c
index 4e783cc7fc4b591cf57d9908100644e70ac65ee8..a336786a22a38d9b36a9062f733a01f1d1cb312a 100644 (file)
--- a/tools/lib/bpf/features.c
+++ b/tools/lib/bpf/features.c
@@ -22,7 +22,7 @@ int probe_fd(int fd)
 
 static int probe_kern_prog_name(int token_fd)
 {
-       const size_t attr_sz = offsetofend(union bpf_attr, prog_name);
+       const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd);
        struct bpf_insn insns[] = {
                BPF_MOV64_IMM(BPF_REG_0, 0),
                BPF_EXIT_INSN(),