On Thu, Jan 21, 2021 at 2:38 PM Arnaldo Carvalho de Melo <arnaldo.melo@xxxxxxxxx> wrote: > > Em Tue, Jan 12, 2021 at 04:27:59PM -0800, Tom Stellard escreveu: > > On 1/12/21 10:40 AM, Jiri Olsa 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. > > > > > > > I backported this patch to pahole 1.19, and I can confirm it fixes the > > segfault for me. > > I'm applying v2 for this patch and based on your above statement I'm > adding a: > > Tested-by: Tom Stellard <tstellar@xxxxxxxxxx> > > Ok? > > Who originally reported this? > The origin was AFAICS the thread where I asked initially [1]. Tom reported in the same thread in [2] that pahole segfaults. Later in the thread Jiri offered a draft of this patch after doing some tests. I have tested all diffs and v1 and v2 of Jiri's patch. ( Anyway, latest pahole ToT plus Jiri's patch did not solve my origin problem. ) So up to you Arnaldo for the credits. - Sedat - [1] https://marc.info/?t=161036949500004&r=1&w=2 [2] https://marc.info/?t=161036949500004&r=1&w=2 > - Arnaldo > > > -Tom > > > > > 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; > > > 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); > > > if (!func || func->generated) > > > continue; > > > func->generated = true; > > > > > > > -- > > - Arnaldo
