From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5BB01C433C1 for ; Sun, 28 Mar 2021 12:09:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B0AF6195F for ; Sun, 28 Mar 2021 12:09:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229577AbhC1MEM (ORCPT ); Sun, 28 Mar 2021 08:04:12 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:26147 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229543AbhC1MDs (ORCPT ); Sun, 28 Mar 2021 08:03:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616933027; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=akFbGFrCz0YDjTwrx18zH9cQEdy+ux2yWLInd1vvevw=; b=RcO/CSXl/j5nRGO9vJaLsHIl0GuB2VGU3jZo+GI+CtLPMAShDKWzggnDRbAmMNKM9yyuJ/ 8rkbC1QWh+MbxcEzKk/IeVzbed4PBWuE3/q/0UZSYpES0Dr3NaaMT7JPdZ9tdtIpWvoG84 KFSps39ombzoa4cG+y+CfNF0YreqB60= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-321-f-iKKB0YPCub_VLgpfHhKA-1; Sun, 28 Mar 2021 08:03:43 -0400 X-MC-Unique: f-iKKB0YPCub_VLgpfHhKA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4FA011009455; Sun, 28 Mar 2021 12:03:41 +0000 (UTC) Received: from krava (unknown [10.40.192.12]) by smtp.corp.redhat.com (Postfix) with SMTP id B7ED15DDAD; Sun, 28 Mar 2021 12:03:39 +0000 (UTC) Date: Sun, 28 Mar 2021 14:03:38 +0200 From: Jiri Olsa To: Andrii Nakryiko Cc: Andrii Nakryiko , bpf , Networking , Alexei Starovoitov , Daniel Borkmann , Kernel Team Subject: Re: [PATCH v4 bpf-next 07/12] libbpf: add BPF static linker BTF and BTF.ext support Message-ID: References: <20210318194036.3521577-1-andrii@kernel.org> <20210318194036.3521577-8-andrii@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Fri, Mar 19, 2021 at 07:58:13PM +0100, Jiri Olsa wrote: > On Fri, Mar 19, 2021 at 11:39:01AM -0700, Andrii Nakryiko wrote: > > On Fri, Mar 19, 2021 at 9:23 AM Jiri Olsa wrote: > > > > > > On Thu, Mar 18, 2021 at 12:40:31PM -0700, Andrii Nakryiko wrote: > > > > > > SNIP > > > > > > > + > > > > + return NULL; > > > > +} > > > > + > > > > +static int linker_fixup_btf(struct src_obj *obj) > > > > +{ > > > > + const char *sec_name; > > > > + struct src_sec *sec; > > > > + int i, j, n, m; > > > > + > > > > + n = btf__get_nr_types(obj->btf); > > > > > > hi, > > > I'm getting bpftool crash when building tests, > > > > > > looks like above obj->btf can be NULL: > > > > I lost if (!obj->btf) return 0; somewhere along the rebases. I'll send > > a fix shortly. But how did you end up with selftests BPF objects built > > without BTF? > > no idea.. I haven't even updated llvm for almost 3 days now ;-) sorry for late follow up on this, and it's actually forgotten empty object in progs directory that was causing this I wonder we should add empty object like below to catch these cases, because there's another place that bpftool is crashing on with it I can send full patch for that if you think it's worth having jirka --- diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 7aad78dbb4b4..aecb6ca52bce 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3165,6 +3165,9 @@ static int add_dummy_ksym_var(struct btf *btf) const struct btf_var_secinfo *vs; const struct btf_type *sec; + if (!btf) + return 0; + sec_btf_id = btf__find_by_name_kind(btf, KSYMS_SEC, BTF_KIND_DATASEC); if (sec_btf_id < 0) diff --git a/tools/testing/selftests/bpf/progs/empty.c b/tools/testing/selftests/bpf/progs/empty.c new file mode 100644 index 000000000000..e69de29bb2d1