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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 226FBC433E0 for ; Tue, 9 Feb 2021 17:27:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C70F764E9C for ; Tue, 9 Feb 2021 17:27:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233231AbhBIR1s (ORCPT ); Tue, 9 Feb 2021 12:27:48 -0500 Received: from smtprelay0109.hostedemail.com ([216.40.44.109]:55350 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S233196AbhBIR1K (ORCPT ); Tue, 9 Feb 2021 12:27:10 -0500 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay04.hostedemail.com (Postfix) with ESMTP id 02FF41821C6A6; Tue, 9 Feb 2021 17:24:18 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: flock94_3b0d3f127609 X-Filterd-Recvd-Size: 3474 Received: from [192.168.1.159] (unknown [47.151.137.21]) (Authenticated sender: joe@perches.com) by omf14.hostedemail.com (Postfix) with ESMTPA; Tue, 9 Feb 2021 17:24:16 +0000 (UTC) Message-ID: Subject: Re: [PATCH v2] checkpatch: do not apply "initialise globals to 0" check to BPF progs From: Joe Perches To: Song Liu , linux-kernel@vger.kernel.org Cc: bpf@vger.kernel.org, Andy Whitcroft Date: Tue, 09 Feb 2021 09:24:15 -0800 In-Reply-To: <20210209170013.3475063-1-songliubraving@fb.com> References: <20210209170013.3475063-1-songliubraving@fb.com> Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.38.1-1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2021-02-09 at 09:00 -0800, Song Liu wrote: > BPF programs explicitly initialise global variables to 0 to make sure > clang (v10 or older) do not put the variables in the common section. > Skip "initialise globals to 0" check for BPF programs to elimiate error > messages like: > >     ERROR: do not initialise globals to 0 >     #19: FILE: samples/bpf/tracex1_kern.c:21: > > Cc: Andy Whitcroft > Cc: Joe Perches > Signed-off-by: Song Liu > > --- > Changes v1 => v2: >   1. Add function exclude_global_initialisers() to keep the code clean. thanks. trivia and a question: > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl [] > @@ -2428,6 +2428,15 @@ sub get_raw_comment { >   return $comment; >  } > > +sub exclude_global_initialisers { > + my ($realfile) = @_; > + > + # Do not check for BPF programs (tools/testing/selftests/bpf/progs/*.c, samples/bpf/*_kern.c, *.bpf.c). > + return $realfile =~ /^tools\/testing\/selftests\/bpf\/progs\/.*\.c/ || > + $realfile =~ /^samples\/bpf\/.*_kern.c/ || The checkpatch convention commonly used for $realfile comparisons to file patterns with directory paths is m@...@ return $realfile =~ m@^tools/testing/selftests/bpf/progs/.*\.c@ || $realfile =~ m@^samples/bpf/.*_kern\.c@ || > + $realfile =~ /.bpf.c$/; And lastly, is this pattern meant to escape the periods? I presume so, but if not, the leading period isn't useful. Maybe: $realfile =~ m@/bpf/.*\.bpf\.c$@; $ git ls-files | grep "\.bpf\.c$" kernel/bpf/preload/iterators/iterators.bpf.c tools/bpf/bpftool/skeleton/pid_iter.bpf.c tools/bpf/bpftool/skeleton/profiler.bpf.c tools/bpf/runqslower/runqslower.bpf.c vs $ git ls-files | grep ".bpf.c$" drivers/net/hyperv/netvsc_bpf.c drivers/net/netdevsim/bpf.c kernel/bpf/preload/iterators/iterators.bpf.c lib/test_bpf.c net/core/lwt_bpf.c net/ipv4/tcp_bpf.c net/ipv4/udp_bpf.c net/netfilter/xt_bpf.c net/sched/act_bpf.c net/sched/cls_bpf.c samples/bpf/test_lwt_bpf.c tools/bpf/bpftool/skeleton/pid_iter.bpf.c tools/bpf/bpftool/skeleton/profiler.bpf.c tools/bpf/runqslower/runqslower.bpf.c tools/build/feature/test-bpf.c tools/build/feature/test-libbpf.c tools/lib/bpf/bpf.c tools/lib/bpf/libbpf.c tools/perf/tests/bpf.c tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c tools/testing/selftests/bpf/progs/fexit_bpf2bpf.c tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c tools/testing/selftests/net/reuseport_bpf.c tools/testing/selftests/seccomp/seccomp_bpf.c