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=-4.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 D75C8C28CC1 for ; Wed, 29 May 2019 09:54:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B0FBC208CB for ; Wed, 29 May 2019 09:54:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cogentembedded-com.20150623.gappssmtp.com header.i=@cogentembedded-com.20150623.gappssmtp.com header.b="b7fhwy9K" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726508AbfE2JyJ (ORCPT ); Wed, 29 May 2019 05:54:09 -0400 Received: from mail-lj1-f195.google.com ([209.85.208.195]:34515 "EHLO mail-lj1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726024AbfE2JyI (ORCPT ); Wed, 29 May 2019 05:54:08 -0400 Received: by mail-lj1-f195.google.com with SMTP id j24so1820343ljg.1 for ; Wed, 29 May 2019 02:54:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cogentembedded-com.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=lNs/p+JI3D1zMvTvnIvX3YzQkmwKplKfx1eyegHlUGs=; b=b7fhwy9KHyUHN1+JlY54Izh0UyO3XPFFISf05d3A09WpwVuLvrThPkOQMuiPkXAHd2 av6G2ajatkgXHfRYOzoCM73Yl7wigIk/GrANkMIGKS0APqqPU8ml399Qb+v4pbmh3kd6 8y9/xQ49KErSRP5pPjn1hWTvlBpTrg8GTFRC8fdrGE++BIime5+AGff2+5UUnMDQfXFk Vvh7BeWG2cAK2O6qE/SzBVHqhgh019YeN0H0NM71HAyAE0UoVUa5bk1oPzWvK9d3Fo2o tImwEqaC5PM0ibTBMRTPr956imoYfWybaalHs2WbQ4RmAaj5VaZ3Zwvh9WBR09VmmcFc Ap+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=lNs/p+JI3D1zMvTvnIvX3YzQkmwKplKfx1eyegHlUGs=; b=YyT2eUrSv8qvW5n0Ux2ZgpzPMV9c/zjnvBVFYt0jDDHvNZau50TiVIz+zrVHXt7HX3 emNi5sxXEOjcxEv5KocWIUQYG/zYTHyEwy6pSdbcV4TkOqHDwHseG8Nn76Au+GZxIzVP dItK/7RdcX4nQ9lm7gTfs8vyMwnpc2j0MF/ZQgmOFpLWhAZOKgzUKoham0BX/e+xNOgq TE1mLvctzUQBlVhyXrHUsrOhLcdl11qcu0cLtf/iCqlVpcJBwfissV7v6WQqAW3OhsGU gJYM/SestfGtdDF6NxMMpO4hlPQwGRC+Rh09LWKNcfCibgPzdni3qE+DSHxa1FCP0QJ0 SI2Q== X-Gm-Message-State: APjAAAWKe3F+IcpbCxrzc8KUgPGzKdLA6JBdIdVxuxn7/iAfRGH7hfEd A1zU4PzVr10Pz6WFeuAMOU3QhzkeeD4= X-Google-Smtp-Source: APXvYqy3vMRQTqltRLbu1to0t8Uw2L6vp3NNLrEAEyPljntAyQr8TzYLsDyYWbDU7gEOUTVGvhAhRg== X-Received: by 2002:a2e:9193:: with SMTP id f19mr26590199ljg.111.1559123646154; Wed, 29 May 2019 02:54:06 -0700 (PDT) Received: from [192.168.0.199] ([31.173.80.1]) by smtp.gmail.com with ESMTPSA id g81sm3390192lfg.22.2019.05.29.02.54.04 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 29 May 2019 02:54:05 -0700 (PDT) Subject: Re: [PATCH bpf] libbpf: Return btf_fd in libbpf__probe_raw_btf To: Michal Rostecki Cc: Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org References: <20190529082941.9440-1-mrostecki@opensuse.org> From: Sergei Shtylyov Message-ID: Date: Wed, 29 May 2019 12:53:42 +0300 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20190529082941.9440-1-mrostecki@opensuse.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello! On 29.05.2019 11:29, Michal Rostecki wrote: > Function load_sk_storage_btf expects that libbpf__probe_raw_btf is > returning a btf descriptor, but before this change it was returning > an information about whether the probe was successful (0 or 1). > load_sk_storage_btf was using that value as an argument to the close > function, which was resulting in closing stdout and thus terminating the > process which used that dunction. Function? :-) > That bug was visible in bpftool. `bpftool feature` subcommand was always > exiting too early (because of closed stdout) and it didn't display all > requested probes. `bpftool -j feature` or `bpftool -p feature` were not > returning a valid json object. > > Fixes: d7c4b3980c18 ("libbpf: detect supported kernel BTF features and sanitize BTF") > Signed-off-by: Michal Rostecki [...] MBR, Sergei