From e6b4e1d759d3bfb7cb84c87cc8f1858da7db8dea Mon Sep 17 00:00:00 2001 From: Changbin Du Date: Sun, 18 Dec 2022 06:35:08 +0800 Subject: [PATCH 1/2] libbpf: Show error info about missing ".BTF" section Show the real problem instead of just saying "No such file or directory". Now will print below info: libbpf: failed to find '.BTF' ELF section in /home/changbin/work/linux/vmlinux Error: failed to load BTF from /home/changbin/work/linux/vmlinux: No such file or directory Signed-off-by: Changbin Du Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20221217223509.88254-2-changbin.du@gmail.com --- tools/lib/bpf/btf.c | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 8cbcef959456..b03250007018 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -1003,6 +1003,7 @@ static struct btf *btf_parse_elf(const char *path, struct btf *base_btf, err = 0; if (!btf_data) { + pr_warn("failed to find '%s' ELF section in %s\n", BTF_ELF_SEC, path); err = -ENOENT; goto done; } From e7f0d5cdd023d8fa53d9ca541b9a55f0eb45618c Mon Sep 17 00:00:00 2001 From: Changbin Du Date: Sun, 18 Dec 2022 06:35:09 +0800 Subject: [PATCH 2/2] bpf: makefiles: Do not generate empty vmlinux.h Remove the empty vmlinux.h if bpftool failed to dump btf info. The empty vmlinux.h can hide real error when reading output of make. This is done by adding .DELETE_ON_ERROR special target in related makefiles. Signed-off-by: Changbin Du Signed-off-by: Andrii Nakryiko Acked-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20221217223509.88254-3-changbin.du@gmail.com --- tools/bpf/bpftool/Makefile | 3 +++ tools/testing/selftests/bpf/Makefile | 3 +++ 2 files changed, 6 insertions(+) diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile index 787b857d3fb5..313fd1b09189 100644 --- a/tools/bpf/bpftool/Makefile +++ b/tools/bpf/bpftool/Makefile @@ -289,3 +289,6 @@ FORCE: .PHONY: all FORCE bootstrap clean install-bin install uninstall .PHONY: doc doc-clean doc-install doc-uninstall .DEFAULT_GOAL := all + +# Delete partially updated (corrupted) files on error +.DELETE_ON_ERROR: diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index c22c43bbee19..205e8c3c346a 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -626,3 +626,6 @@ EXTRA_CLEAN := $(TEST_CUSTOM_PROGS) $(SCRATCH_DIR) $(HOST_SCRATCH_DIR) \ liburandom_read.so) .PHONY: docs docs-clean + +# Delete partially updated (corrupted) files on error +.DELETE_ON_ERROR: