libbpf: Fix struct end padding in btf_dump

[ Upstream commit b4099769f3 ]

Fix a case where explicit padding at the end of a struct is necessary
due to non-standart alignment requirements of fields (which BTF doesn't
capture explicitly).

Fixes: 351131b51c ("libbpf: add btf_dump API for BTF-to-C conversion")
Reported-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20191008231009.2991130-2-andriin@fb.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Andrii Nakryiko 2019-10-08 16:10:06 -07:00 committed by Greg Kroah-Hartman
parent 8ff8178124
commit f97e8686e6

View file

@ -876,7 +876,6 @@ static void btf_dump_emit_struct_def(struct btf_dump *d,
__u16 vlen = btf_vlen(t);
packed = is_struct ? btf_is_struct_packed(d->btf, id, t) : 0;
align = packed ? 1 : btf_align_of(d->btf, id);
btf_dump_printf(d, "%s%s%s {",
is_struct ? "struct" : "union",
@ -906,6 +905,13 @@ static void btf_dump_emit_struct_def(struct btf_dump *d,
btf_dump_printf(d, ";");
}
/* pad at the end, if necessary */
if (is_struct) {
align = packed ? 1 : btf_align_of(d->btf, id);
btf_dump_emit_bit_padding(d, off, t->size * 8, 0, align,
lvl + 1);
}
if (vlen)
btf_dump_printf(d, "\n");
btf_dump_printf(d, "%s}", pfx(lvl));