On Tue, Jan 12, 2021 at 10:43 AM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> When processing kernel image build by clang we can
> find some functions without the name, which causes
> pahole to segfault.
>
> Adding extra checks to make sure we always have
> function's name defined before using it.
>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
> btf_encoder.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/btf_encoder.c b/btf_encoder.c
> index 333973054b61..17f7a14f2ef0 100644
> --- a/btf_encoder.c
> +++ b/btf_encoder.c
> @@ -72,6 +72,8 @@ static int collect_function(struct btf_elf *btfe, GElf_Sym *sym)
>
> if (elf_sym__type(sym) != STT_FUNC)
> return 0;
> + if (!elf_sym__name(sym, btfe->symtab))
> + return 0;
elf_sym__name() is called below again, so might be better to just use
local variable to store result?
>
> if (functions_cnt == functions_alloc) {
> functions_alloc = max(1000, functions_alloc * 3 / 2);
> @@ -730,9 +732,11 @@ int cu__encode_btf(struct cu *cu, int verbose, bool force,
> if (!has_arg_names(cu, &fn->proto))
> continue;
> if (functions_cnt) {
> - struct elf_function *func;
> + const char *name = function__name(fn, cu);
> + struct elf_function *func = NULL;
>
> - func = find_function(btfe, function__name(fn, cu));
> + if (name)
> + func = find_function(btfe, name);
isn't this a more convoluted way of writing:
name = function__name(fn, cu);
if (!name)
continue;
func = find_function(btfe, name);
if (!func || func->generated)
continue
?
> if (!func || func->generated)
> continue;
> func->generated = true;
> --
> 2.26.2
>
