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=-3.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_GIT 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 3B5D8C04E53 for ; Wed, 15 May 2019 13:48:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 06DF02070D for ; Wed, 15 May 2019 13:48:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kinvolk.io header.i=@kinvolk.io header.b="Wmz44KxN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727855AbfEONsQ (ORCPT ); Wed, 15 May 2019 09:48:16 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:38404 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726635AbfEONsP (ORCPT ); Wed, 15 May 2019 09:48:15 -0400 Received: by mail-wr1-f67.google.com with SMTP id d18so2222094wrs.5 for ; Wed, 15 May 2019 06:48:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kinvolk.io; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=DgryeVXBfS0oVlWILr3leOrpFjnwkDVNHwaRTJYmSLs=; b=Wmz44KxNc+WRAG37tbtVeUY8uQiVejN1WhSs1iXgHDYxv4oCMYT+yjQ0veYGBot2ba yxeaLfF6beXeyGniY/YNQOUzQHVR2u0s9JyJ7nM+CFJhbe3RjRPe3YaJ1ahLsN/m6O/7 mAtELVAbVymulWB8lnXEtF7Tbyq3yGIbhxozQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=DgryeVXBfS0oVlWILr3leOrpFjnwkDVNHwaRTJYmSLs=; b=C8F4wtRDPW1KTtoTyUtUH6fW0eSEHDMC6gjr0C/nVDDWnN97+uGcHuMcdc61YV326d zHQGRZG/5U6TEl28IbVGhmtNHpSfHgXSoWZ/+TMPMJDd26DdOhG1VQVhVhmS8/+VWIyP wQH23I4yrSeZDIuH1iqCJmq2lN3CSRnGq+BMs6nOxEh3AnGqAVAQFxOEk9/Dm9xIHjno geCOYGmETgNPSvqLVH+iy1hF64k4qiwcC9M/dIASh6H3yS3UWYzgvRIbe9o0leaGCMHP Ey9Cg3AvYqxH3IpWOWMEKo4vpnzeANcHXu7UcxnrktZ3R3WLF6Fo7nY2uZ8YWWd0C6qr IGQA== X-Gm-Message-State: APjAAAUipp1YcVGn3KmMazoRzxQay6wXe3NkTK4lSapy1O2TU0YTN319 R78vRw79/n/xWc0VY1I6EtZCzA== X-Google-Smtp-Source: APXvYqxoKpq4i6hxR1Vd+uEIthTPeUr9Z2rxDVTBtNcWEq/8JUOsD/KwIJmcXYs0OmIhopWuSg9uyw== X-Received: by 2002:adf:8385:: with SMTP id 5mr8392281wre.194.1557928093806; Wed, 15 May 2019 06:48:13 -0700 (PDT) Received: from localhost.localdomain (ip5f5aea35.dynamic.kabel-deutschland.de. [95.90.234.53]) by smtp.gmail.com with ESMTPSA id v5sm4498506wra.83.2019.05.15.06.48.11 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 15 May 2019 06:48:12 -0700 (PDT) From: Krzesimir Nowak To: bpf@vger.kernel.org Cc: iago@kinvolk.io, alban@kinvolk.io, Krzesimir Nowak , Shuah Khan , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , Andrey Ignatov , Jiong Wang , Jakub Kicinski , linux-kselftest@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH bpf v1 0/3] Test the 32bit narrow reads Date: Wed, 15 May 2019 15:47:25 +0200 Message-Id: <20190515134731.12611-1-krzesimir@kinvolk.io> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org These patches try to test the fix made in commit e2f7fc0ac695 ("bpf: fix undefined behavior in narrow load handling"). The problem existed in the generated BPF bytecode that was doing a 32bit narrow read of a 64bit field, so to test it the code would need to be executed. Currently the only such field exists in BPF_PROG_TYPE_PERF_EVENT, which is not supported by bpf_prog_test_run(). First commit adds the test, but since I can't run it, I'm not sure if it is even valid (because endianness, for example). Second commit adds a message to test_verifier when it couldn't run the program because of lack permissions or program type being not supported. Third commit fixes a possible problem with errno. With these patches, I get the following output on my test: /kernel/tools/testing/selftests/bpf$ sudo ./test_verifier 920 920 #920/p 32bit loads of a 64bit field (both least and most significant words) Did not run the program (not supported) OK Summary: 1 PASSED, 0 SKIPPED, 0 FAILED So it looks like I need to pick a different approach. Krzesimir Nowak (3): selftests/bpf: Test correctness of narrow 32bit read on 64bit field selftests/bpf: Print a message when tester could not run a program selftests/bpf: Avoid a clobbering of errno tools/testing/selftests/bpf/test_verifier.c | 19 +++++++++++++++---- .../testing/selftests/bpf/verifier/var_off.c | 15 +++++++++++++++ 2 files changed, 30 insertions(+), 4 deletions(-) -- 2.20.1