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=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,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 3DEB2C4338F for ; Mon, 26 Jul 2021 20:16:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A6B660F6E for ; Mon, 26 Jul 2021 20:16:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231540AbhGZTgD (ORCPT ); Mon, 26 Jul 2021 15:36:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229646AbhGZTgC (ORCPT ); Mon, 26 Jul 2021 15:36:02 -0400 Received: from mail-yb1-xb2e.google.com (mail-yb1-xb2e.google.com [IPv6:2607:f8b0:4864:20::b2e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 18D3CC061757 for ; Mon, 26 Jul 2021 13:16:30 -0700 (PDT) Received: by mail-yb1-xb2e.google.com with SMTP id q15so16899815ybu.2 for ; Mon, 26 Jul 2021 13:16:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=v/Hh0BhXPg+c/FHcyqxLjFQd7yO/ysXyVL2dIDqJLZ0=; b=P3fNDzl+PL28tuZVAYkjCX9nR86dWwu9aGaDqgWitTbzhhkIaEDF1qUkaU+QPuySnN IRmJPFv4Cp2B6URKXFmDAGtyV8S8981ImE73K9MllhtGOCRKK3X3fmDbETHE3+Y/zq4W 1cCWrE3wn7rz/YTFLTw2MD66IQfg4hk3hPi85B8iRylEy/uF6NcLttjmMH3/epSxYEKx LN4KvmWthoeV437QDgbyUrkF3+hrTC1oaXaFOIE+gVn1Yn6vPk0ExVQxx2zMrEYQP0SY DljfSXcNomLtRSB/87w7b4OXp20xFZHkyqvaN9iQYHBd1ujAJKOepcKT/BV7MycUXMTJ 7zXg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=v/Hh0BhXPg+c/FHcyqxLjFQd7yO/ysXyVL2dIDqJLZ0=; b=LiYUPDZB4zArgmueqiglC7AOT4wlrkQdCfH/4BFEkdnFD7E8/9KxfDi2sObHkRqwMq BnUahI9IYDpuZxqa0lkD53J/MY57w93ctkHG2BvrnvEP6vA0AhfcH17Nkuftu3Ms70CV wRat4KbqOHkkPdH32iYD4oqk/+LPglXNCv8vrmCqJxwo/2rRE61q9pgLCe1SxsmUsS0L M8iClhmeDihy30v7r5hg49FdysozbxTqHWvvKUWIDd7wh0qswq97G5a7MFslroVEowyC 3599eJwzRASZg/HzX8q6JF5Nq37dmjFnTfKU00pAmxfYOUV+16Ud1NRhEb2khv7vg1j+ YIWA== X-Gm-Message-State: AOAM53357ds7QzDyz9JF+3x++xgrAznhBQ6HeDSd2XNvL4QohGkhv9cZ HO2l9dyoNhLHF74D0RdMaFaEjr+MB4xkmzI3TcU= X-Google-Smtp-Source: ABdhPJyu2JjGO0pLxx4c5AczizVXFzPafoysnW44uN715Hk58CQPcgDcOnoGkFUjEyAmW6P149DjGNbX944xA9Umj7c= X-Received: by 2002:a25:9942:: with SMTP id n2mr26803371ybo.230.1627330589420; Mon, 26 Jul 2021 13:16:29 -0700 (PDT) MIME-Version: 1.0 References: <20210725141814.2000828-1-hengqi.chen@gmail.com> <20210725141814.2000828-2-hengqi.chen@gmail.com> In-Reply-To: <20210725141814.2000828-2-hengqi.chen@gmail.com> From: Andrii Nakryiko Date: Mon, 26 Jul 2021 13:16:18 -0700 Message-ID: Subject: Re: [PATCH bpf-next 1/2] tools/resolve_btfids: emit warnings and patch zero id for missing symbols To: Hengqi Chen Cc: bpf , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Yonghong Song , john fastabend , Jiri Olsa , Yaniv Agman Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Sun, Jul 25, 2021 at 7:18 AM Hengqi Chen wrote: > > Kernel functions referenced by .BTF_ids may changed from global to static > and get inlined and thus disappears from BTF. This causes kernel build > failure when resolve_btfids do id patch for symbols in .BTF_ids in vmlinux. > Update resolve_btfids to emit warning messages and patch zero id for missing > symbols instead of aborting kernel build process. > > Signed-off-by: Hengqi Chen > --- > tools/bpf/resolve_btfids/main.c | 13 +++++++------ > 1 file changed, 7 insertions(+), 6 deletions(-) > > diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c > index 3ad9301b0f00..3ea19e33250d 100644 > --- a/tools/bpf/resolve_btfids/main.c > +++ b/tools/bpf/resolve_btfids/main.c > @@ -291,7 +291,7 @@ static int compressed_section_fix(Elf *elf, Elf_Scn *scn, GElf_Shdr *sh) > sh->sh_addralign = expected; > > if (gelf_update_shdr(scn, sh) == 0) { > - printf("FAILED cannot update section header: %s\n", > + pr_err("FAILED cannot update section header: %s\n", > elf_errmsg(-1)); > return -1; > } > @@ -317,6 +317,7 @@ static int elf_collect(struct object *obj) > > elf = elf_begin(fd, ELF_C_RDWR_MMAP, NULL); > if (!elf) { > + close(fd); > pr_err("FAILED cannot create ELF descriptor: %s\n", > elf_errmsg(-1)); > return -1; > @@ -484,7 +485,7 @@ static int symbols_resolve(struct object *obj) > err = libbpf_get_error(btf); > if (err) { > pr_err("FAILED: load BTF from %s: %s\n", > - obj->path, strerror(-err)); > + obj->btf ?: obj->path, strerror(-err)); > return -1; > } > > @@ -555,8 +556,7 @@ static int id_patch(struct object *obj, struct btf_id *id) > int i; > > if (!id->id) { > - pr_err("FAILED unresolved symbol %s\n", id->name); > - return -EINVAL; > + pr_err("WARN: unresolved symbol %s\n", id->name); we should probably give a bit more information for people to get back to us for this. For starters, maybe prefix the message with "resolve_btfids:" so that people at least can grep something relevant? > } > > for (i = 0; i < id->addr_cnt; i++) { > @@ -734,8 +734,9 @@ int main(int argc, const char **argv) > > err = 0; > out: > - if (obj.efile.elf) > + if (obj.efile.elf) { > elf_end(obj.efile.elf); > - close(obj.efile.fd); > + close(obj.efile.fd); > + } > return err; > } > -- > 2.25.1