From 93442f132b94721c7143ace7f43e51a9025f46fd Mon Sep 17 00:00:00 2001 From: Grant Seltzer Date: Wed, 20 Apr 2022 12:12:24 -0400 Subject: [PATCH] libbpf: Add error returns to two API functions This adds an error return to the following API functions: - bpf_program__set_expected_attach_type() - bpf_program__set_type() In both cases, the error occurs when the BPF object has already been loaded when the function is called. In this case -EBUSY is returned. Signed-off-by: Grant Seltzer Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20220420161226.86803-1-grantseltzer@gmail.com --- tools/lib/bpf/libbpf.c | 12 ++++++++++-- tools/lib/bpf/libbpf.h | 6 +++--- 2 files changed, 13 insertions(+), 5 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 8375021800f3..342340aee948 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -8562,9 +8562,13 @@ enum bpf_prog_type bpf_program__type(const struct bpf_program *prog) return prog->type; } -void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type) +int bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type) { + if (prog->obj->loaded) + return libbpf_err(-EBUSY); + prog->type = type; + return 0; } static bool bpf_program__is_type(const struct bpf_program *prog, @@ -8609,10 +8613,14 @@ enum bpf_attach_type bpf_program__expected_attach_type(const struct bpf_program return prog->expected_attach_type; } -void bpf_program__set_expected_attach_type(struct bpf_program *prog, +int bpf_program__set_expected_attach_type(struct bpf_program *prog, enum bpf_attach_type type) { + if (prog->obj->loaded) + return libbpf_err(-EBUSY); + prog->expected_attach_type = type; + return 0; } __u32 bpf_program__flags(const struct bpf_program *prog) diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 63d66f1adf1a..66735623ca63 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -686,12 +686,12 @@ LIBBPF_DEPRECATED_SINCE(0, 8, "use bpf_program__set_type() instead") LIBBPF_API int bpf_program__set_sk_lookup(struct bpf_program *prog); LIBBPF_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog); -LIBBPF_API void bpf_program__set_type(struct bpf_program *prog, - enum bpf_prog_type type); +LIBBPF_API int bpf_program__set_type(struct bpf_program *prog, + enum bpf_prog_type type); LIBBPF_API enum bpf_attach_type bpf_program__expected_attach_type(const struct bpf_program *prog); -LIBBPF_API void +LIBBPF_API int bpf_program__set_expected_attach_type(struct bpf_program *prog, enum bpf_attach_type type);