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=-12.8 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,URIBL_BLOCKED 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 3888FC4338F for ; Fri, 30 Jul 2021 18:40:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A38C60E9B for ; Fri, 30 Jul 2021 18:40:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230264AbhG3Skr (ORCPT ); Fri, 30 Jul 2021 14:40:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50572 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229773AbhG3Skq (ORCPT ); Fri, 30 Jul 2021 14:40:46 -0400 Received: from mail-yb1-xb35.google.com (mail-yb1-xb35.google.com [IPv6:2607:f8b0:4864:20::b35]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 37319C06175F for ; Fri, 30 Jul 2021 11:40:40 -0700 (PDT) Received: by mail-yb1-xb35.google.com with SMTP id m193so2857651ybf.9 for ; Fri, 30 Jul 2021 11:40:40 -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=0ZJf7NdmBf0ZXmV93u+O0u4Wzjjo5mi6y5VWYy13mIc=; b=AfaMobeN17tZDFrEvG8QBJJjGhQLZX4TVzBoXbuCyOOI2lO4w8z50iKpj0nfXeunce OZ/Q1HqMI8soheQcM5qMe9ynX3bfMHGAxgdXnj3IKLkIbXMvFSiC+fb9ZWYubBMvJ23r J+sMCenFhVIuXFAXUqtfNMmmzIzz06pDondYNzN+Fyx/GQpQ+5Zewl1u6z+VrF6jIDAx KXlSG493WoAkP/DmAFU+Z19NUQ4cW4uqs/l3aC/+mur60E/n/TlwRlghBe9PUGVstJSN foLWy/piPcYJMBdBfChAT+WOSJA9VrZpbQ3D57m165pob0vSk1IMe/e9umAT231pkIq8 FsyA== 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=0ZJf7NdmBf0ZXmV93u+O0u4Wzjjo5mi6y5VWYy13mIc=; b=lOTwpnCeOSgV3ce4x7/Xkx/CFArJrgrpSdMxLB1PUvm1nqEzdqXYt9cnEuBCEgRhQF ZdiCb3C4MydPrA+txcvjS5ZM8bgD18EU4r1y2mbP10HO/lS67vvGVlf8NZRhu+uqBw/t 1LepfHE2Z/hR1TkypqP/sqHzpV+vnlqHVU2fppl0aVKG14vZd6j3HVkOrqlkHUnoOBup ILeSb0dNBn8GW5RifeLeDYovuHaglmssK3ejzKOHk8dyTe1W10NonpljEt0GipCTSF9V LLrapr+1ZEBevr4TRWCoR7vvbDdw5O4Fzai8nL7G9ot3ExLO67OhhNrX8597p4UgnnOB wk+w== X-Gm-Message-State: AOAM533LvcveXbMlMYG1giV6mu7i1Rb2GE03pS4FGkz+nfPXJ4EVJlvj +1tn3I9Rmd3kH4touCzIaGiOZcxxYS2fiJTmSMg= X-Google-Smtp-Source: ABdhPJxgB7aRYEojy8rW3j6kM292EyaGUpyarOeK4kOnu3UjtizdyNUTwSlQhPONvSCTurV9xtb7rCUEk/aBND6f1n8= X-Received: by 2002:a25:2901:: with SMTP id p1mr4971870ybp.459.1627670439333; Fri, 30 Jul 2021 11:40:39 -0700 (PDT) MIME-Version: 1.0 References: <20210729045516.7373-1-zhoufeng.zf@bytedance.com> In-Reply-To: <20210729045516.7373-1-zhoufeng.zf@bytedance.com> From: Andrii Nakryiko Date: Fri, 30 Jul 2021 11:40:28 -0700 Message-ID: Subject: Re: [PATCH] lib/bpf: Fix btf_load error lead to enable debug log To: Feng zhou Cc: Networking , Stephen Hemminger , kuznet@ms2.inr.ac.ru, duanxiongchun@bytedance.com, Dongdong Wang , chenzhuowen.simon@bytedance.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Jul 28, 2021 at 9:55 PM Feng zhou wrote: > > From: Feng Zhou > > Use tc with no verbose, when bpf_btf_attach fail, > the conditions: > "if (fd < 0 && (errno == ENOSPC || !ctx->log_size))" > will make ctx->log_size != 0. And then, bpf_prog_attach, > ctx->log_size != 0. so enable debug log. > The verifier log sometimes is so chatty on larger programs. > bpf_prog_attach is failed. > "Log buffer too small to dump verifier log 16777215 bytes (9 tries)!" > > BTF load failure does not affect prog load. prog still work. > So when BTF/PROG load fail, enlarge log_size and re-fail with > having verbose. > > Signed-off-by: Feng Zhou > --- This seems to be targeted against iproute2? It would be good to specify that as [PATCH iproute2] or something. > lib/bpf_legacy.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/lib/bpf_legacy.c b/lib/bpf_legacy.c > index 8a03b9c2..d824388c 100644 > --- a/lib/bpf_legacy.c > +++ b/lib/bpf_legacy.c > @@ -1531,7 +1531,7 @@ retry: > * into our buffer. Still, try to give a debuggable error > * log for the user, so enlarge it and re-fail. > */ > - if (fd < 0 && (errno == ENOSPC || !ctx->log_size)) { > + if (fd < 0 && errno == ENOSPC) { > if (tries++ < 10 && !bpf_log_realloc(ctx)) > goto retry; > > @@ -2069,7 +2069,7 @@ retry: > fd = bpf_btf_load(ctx->btf_data->d_buf, ctx->btf_data->d_size, > ctx->log, ctx->log_size); > if (fd < 0 || ctx->verbose) { > - if (fd < 0 && (errno == ENOSPC || !ctx->log_size)) { > + if (fd < 0 && errno == ENOSPC) { > if (tries++ < 10 && !bpf_log_realloc(ctx)) > goto retry; > > -- > 2.11.0 >