Commit 9c6c0449 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
Browse files

bpftool: Set errno on skeleton failures and propagate errors 



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.

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Acked-by: default avatarToke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210525035935.1461796-6-andrii@kernel.org
parent e9fc3ce9

tools/bpf/bpftool/gen.c

+18 −9
Original line number Diff line number Diff line
@@ -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\