From: Eduard Zingerman Date: Sat, 1 Oct 2022 10:44:24 +0000 (+0300) Subject: bpftool: Print newline before '}' for struct with padding only fields X-Git-Tag: v6.1.37~2280 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=77e41187a3875ef747868ff19646a41375f2f508;p=platform%2Fkernel%2Flinux-starfive.git bpftool: Print newline before '}' for struct with padding only fields [ Upstream commit 44a726c3f23cf762ef4ce3c1709aefbcbe97f62c ] btf_dump_emit_struct_def attempts to print empty structures at a single line, e.g. `struct empty {}`. However, it has to account for a case when there are no regular but some padding fields in the struct. In such case `vlen` would be zero, but size would be non-zero. E.g. here is struct bpf_timer from vmlinux.h before this patch: struct bpf_timer { long: 64; long: 64;}; And after this patch: struct bpf_dynptr { long: 64; long: 64; }; Signed-off-by: Eduard Zingerman Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20221001104425.415768-1-eddyz87@gmail.com Signed-off-by: Sasha Levin --- diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c index 5610271..80a15a6 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -1011,7 +1011,11 @@ static void btf_dump_emit_struct_def(struct btf_dump *d, if (is_struct) btf_dump_emit_bit_padding(d, off, t->size * 8, align, false, lvl + 1); - if (vlen) + /* + * Keep `struct empty {}` on a single line, + * only print newline when there are regular or padding fields. + */ + if (vlen || t->size) btf_dump_printf(d, "\n"); btf_dump_printf(d, "%s}", pfx(lvl)); if (packed)