[PATCH v2 bpf-next 5/5] bpftool: set errno on skeleton failures and propagate errors
From: Andrii Nakryiko <andrii@kernel.org>
Date: 2021-05-25 04:00:05
Also in:
netdev
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
Follow libbpf's error handling conventions and pass through errors and errno properly. Skeleton code always returned NULL on errors (not ERR_PTR(err)), so there are no backwards compatibility concerns. But now we also set errno properly, so it's possible to distinguish different reasons for failure, if necessary. Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Toke Høiland-Jørgensen <redacted> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> --- tools/bpf/bpftool/gen.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-)
diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index 13b0aa789178..1d71ff8c52fa 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c@@ -713,6 +713,7 @@ static int do_skeleton(int argc, char **argv) #ifndef %2$s \n\ #define %2$s \n\ \n\ + #include <errno.h> \n\ #include <stdlib.h> \n\ #include <bpf/libbpf.h> \n\ \n\
@@ -793,18 +794,23 @@ static int do_skeleton(int argc, char **argv) %1$s__open_opts(const struct bpf_object_open_opts *opts) \n\ { \n\ struct %1$s *obj; \n\ + int err; \n\ \n\ obj = (struct %1$s *)calloc(1, sizeof(*obj)); \n\ - if (!obj) \n\ + if (!obj) { \n\ + errno = ENOMEM; \n\ return NULL; \n\ - if (%1$s__create_skeleton(obj)) \n\ - goto err; \n\ - if (bpf_object__open_skeleton(obj->skeleton, opts)) \n\ - goto err; \n\ + } \n\ + \n\ + err = %1$s__create_skeleton(obj); \n\ + err = err ?: bpf_object__open_skeleton(obj->skeleton, opts);\n\ + if (err) \n\ + goto err_out; \n\ \n\ return obj; \n\ - err: \n\ + err_out: \n\ %1$s__destroy(obj); \n\ + errno = -err; \n\ return NULL; \n\ } \n\ \n\
@@ -824,12 +830,15 @@ static int do_skeleton(int argc, char **argv) %1$s__open_and_load(void) \n\ { \n\ struct %1$s *obj; \n\ + int err; \n\ \n\ obj = %1$s__open(); \n\ if (!obj) \n\ return NULL; \n\ - if (%1$s__load(obj)) { \n\ + err = %1$s__load(obj); \n\ + if (err) { \n\ %1$s__destroy(obj); \n\ + errno = -err; \n\ return NULL; \n\ } \n\ return obj; \n\
@@ -860,7 +869,7 @@ static int do_skeleton(int argc, char **argv) \n\ s = (struct bpf_object_skeleton *)calloc(1, sizeof(*s));\n\ if (!s) \n\ - return -1; \n\ + goto err; \n\ obj->skeleton = s; \n\ \n\ s->sz = sizeof(*s); \n\
@@ -949,7 +958,7 @@ static int do_skeleton(int argc, char **argv) return 0; \n\ err: \n\ bpf_object__destroy_skeleton(s); \n\ - return -1; \n\ + return -ENOMEM; \n\ } \n\ \n\ #endif /* %s */ \n\
--
2.30.2