From: Grant Seltzer <grantseltzer@gmail.com>
Date: Wed, 20 Apr 2022 12:12:24 -0400
Subject: libbpf: Add error returns to two API functions
Patch-mainline: v5.19-rc1
Git-commit: 93442f132b94721c7143ace7f43e51a9025f46fd
References: jsc#PED-1377
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 <grantseltzer@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220420161226.86803-1-grantseltzer@gmail.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
tools/lib/bpf/libbpf.c | 12 ++++++++++--
tools/lib/bpf/libbpf.h | 6 +++---
2 files changed, 13 insertions(+), 5 deletions(-)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -8562,9 +8562,13 @@ enum bpf_prog_type bpf_program__type(con
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__expect
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)
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -686,12 +686,12 @@ LIBBPF_DEPRECATED_SINCE(0, 8, "use bpf_p
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);