On Wed, Jan 13, 2021 at 11:25 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>
Applied on top of latest pahole Git.
Tested-by: Sedat Dilek <sedat.dilek@xxxxxxxxx>
- Sedat -
> ---
> v2 changes:
> - reorg the code based on Andrii's suggestion
>
> btf_encoder.c | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/btf_encoder.c b/btf_encoder.c
> index 333973054b61..5557c9efd365 100644
> --- a/btf_encoder.c
> +++ b/btf_encoder.c
> @@ -68,10 +68,14 @@ static int collect_function(struct btf_elf *btfe, GElf_Sym *sym)
> struct elf_function *new;
> static GElf_Shdr sh;
> static int last_idx;
> + const char *name;
> int idx;
>
> if (elf_sym__type(sym) != STT_FUNC)
> return 0;
> + name = elf_sym__name(sym, btfe->symtab);
> + if (!name)
> + return 0;
>
> if (functions_cnt == functions_alloc) {
> functions_alloc = max(1000, functions_alloc * 3 / 2);
> @@ -94,7 +98,7 @@ static int collect_function(struct btf_elf *btfe, GElf_Sym *sym)
> last_idx = idx;
> }
>
> - functions[functions_cnt].name = elf_sym__name(sym, btfe->symtab);
> + functions[functions_cnt].name = name;
> functions[functions_cnt].addr = elf_sym__value(sym);
> functions[functions_cnt].sh_addr = sh.sh_addr;
> functions[functions_cnt].generated = false;
> @@ -731,8 +735,13 @@ int cu__encode_btf(struct cu *cu, int verbose, bool force,
> continue;
> if (functions_cnt) {
> struct elf_function *func;
> + const char *name;
> +
> + name = function__name(fn, cu);
> + if (!name)
> + continue;
>
> - func = find_function(btfe, function__name(fn, cu));
> + func = find_function(btfe, name);
> if (!func || func->generated)
> continue;
> func->generated = true;
> --
> 2.26.2
>
