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=-6.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 01295C4741F for ; Fri, 25 Sep 2020 00:50:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9AD7D20702 for ; Fri, 25 Sep 2020 00:50:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="dDZ+FP4+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726861AbgIYAu4 (ORCPT ); Thu, 24 Sep 2020 20:50:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40740 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726700AbgIYAuz (ORCPT ); Thu, 24 Sep 2020 20:50:55 -0400 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF34CC0613CE; Thu, 24 Sep 2020 17:50:55 -0700 (PDT) Received: by mail-pg1-x541.google.com with SMTP id k133so1048504pgc.7; Thu, 24 Sep 2020 17:50:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=ZEj7jJ2RajYtDSmZOrLZRT9SFF9pAXigrpnF3pG53vM=; b=dDZ+FP4+FHl4gUgw2wF/Uuem6fqtpWvDOGt52UFUkBzGXHV+7Jth4pWeCB+5gryZAM ho/vb6eJx797Q1muCG0bIyeZbQZt72VVccaeY6H9VP8YNWHY/k75gZ+zTo+GFx2Xn4XF 7171eRlBErtdeQDB10Mm6+oWyYhej7YIdSzPPlOaKAinmObCDKdb3l/Y9uDZKTyYUdZ1 NFYuIBNNdMB4pVHpx/DVdlf6MuWuhzDv0Dyn5Q2L5+MINFib8sOYfaL4avO/Q9gqkTpg DQlszmtid4zzx4T18TF0cLdVEnQNNLc5AuLsT31HlQdKwurfwVw91TBvIGtu4g59URGl SITg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=ZEj7jJ2RajYtDSmZOrLZRT9SFF9pAXigrpnF3pG53vM=; b=PVDtnYdim6ozjWfDgaEToCb8pW8Yd2gzY3LSD4vKVXHFYvs+fCjbmt6lGbzAMMUo5F O920QxbRLgq0JZgCWU7oir3+MxCRAo+U9HllLEYIPNvF0AvQAnt7fiRnA/PiV9SOOjlu sOtzbY3i6Rr+ZzMdK/WKIW/NlN9yg1+awzP6C+PUtetGeSOvfg/jqg7vS7qt2YzRpGq1 YiNHWe3ftkfBRRIeH2NucjqkSnDPi6KI2Vwn7lRH1NJh8jRemBWXC2ohkYsVTwLElAlI 02QA6peuXRW4sjWO5howTqoubJ0A6ryVIsRWXNuVEuaoi0+QEiUdqLqFFsFDIy/p6u5U 30Og== X-Gm-Message-State: AOAM530SjOA/VGrLIHSUgnBCp/5E+0vW+aKCoUnfK8JRG9pNUArJxxSG ziE+SupkHMVE5rbsO0O0EYQ= X-Google-Smtp-Source: ABdhPJwtrAG2FWI+khpVtPUig0amsxnQGdDTAGByGD0X+rSPF0F08DoZ59Jg1jOIX7UA+NhmyRRWyA== X-Received: by 2002:aa7:8ec7:0:b029:13e:d13d:a137 with SMTP id b7-20020aa78ec70000b029013ed13da137mr1676726pfr.31.1600995055255; Thu, 24 Sep 2020 17:50:55 -0700 (PDT) Received: from ast-mbp.dhcp.thefacebook.com ([2620:10d:c090:400::5:49ed]) by smtp.gmail.com with ESMTPSA id c185sm610932pfb.123.2020.09.24.17.50.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 24 Sep 2020 17:50:54 -0700 (PDT) Date: Thu, 24 Sep 2020 17:50:51 -0700 From: Alexei Starovoitov To: Alan Maguire Cc: ast@kernel.org, daniel@iogearbox.net, andriin@fb.com, yhs@fb.com, linux@rasmusvillemoes.dk, andriy.shevchenko@linux.intel.com, pmladek@suse.com, kafai@fb.com, songliubraving@fb.com, john.fastabend@gmail.com, kpsingh@chromium.org, shuah@kernel.org, rdna@fb.com, scott.branden@broadcom.com, quentin@isovalent.com, cneirabustos@gmail.com, jakub@cloudflare.com, mingo@redhat.com, rostedt@goodmis.org, bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, acme@kernel.org Subject: Re: [PATCH v6 bpf-next 4/6] selftests/bpf: add bpf_snprintf_btf helper tests Message-ID: <20200925005051.nqf6ru46psex7oh4@ast-mbp.dhcp.thefacebook.com> References: <1600883188-4831-1-git-send-email-alan.maguire@oracle.com> <1600883188-4831-5-git-send-email-alan.maguire@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1600883188-4831-5-git-send-email-alan.maguire@oracle.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Sep 23, 2020 at 06:46:26PM +0100, Alan Maguire wrote: > +static int __strncmp(const void *m1, const void *m2, size_t len) > +{ > + const unsigned char *s1 = m1; > + const unsigned char *s2 = m2; > + int i, delta = 0; > + > +#pragma clang loop unroll(full) Shouldn't be needed? The verifier supports bounded loops. > + for (i = 0; i < len; i++) { > + delta = s1[i] - s2[i]; > + if (delta || s1[i] == 0 || s2[i] == 0) > + break; > + } > + return delta; > +} > + > +/* Use __builtin_btf_type_id to test snprintf_btf by type id instead of name */ > +#if __has_builtin(__builtin_btf_type_id) > +#define TEST_BTF_BY_ID(_str, _typestr, _ptr, _hflags) \ > + do { \ > + int _expected_ret = ret; \ > + _ptr.type = 0; \ > + _ptr.type_id = __builtin_btf_type_id(_typestr, 0); \ The test is passing for me, but I don't understand why :) __builtin_btf_type_id(, 0); means btf_id of the bpf program. While bpf_snprintf_btf() is treating it as btf_id of vmlinux_btf. So it really should have been __builtin_btf_type_id(,1); The following diff works: diff --git a/tools/testing/selftests/bpf/progs/netif_receive_skb.c b/tools/testing/selftests/bpf/progs/netif_receive_skb.c index b4f96f1f6830..bffa786e3b03 100644 --- a/tools/testing/selftests/bpf/progs/netif_receive_skb.c +++ b/tools/testing/selftests/bpf/progs/netif_receive_skb.c @@ -45,7 +45,7 @@ static int __strncmp(const void *m1, const void *m2, size_t len) do { \ int _expected_ret = ret; \ _ptr.type = 0; \ - _ptr.type_id = __builtin_btf_type_id(_typestr, 0); \ + _ptr.type_id = __builtin_btf_type_id(_typestr, 1); \ ret = bpf_snprintf_btf(_str, STRSIZE, &_ptr, \ sizeof(_ptr), _hflags); \ if (ret != _expected_ret) { \ @@ -88,7 +88,7 @@ static int __strncmp(const void *m1, const void *m2, size_t len) ret = -EBADMSG; \ break; \ } \ - TEST_BTF_BY_ID(_str, #_type, _ptr, _hflags); \ + TEST_BTF_BY_ID(_str, _ptr, _ptr, _hflags); \ But still makes me suspicious of the test. I haven't debugged further.