From patchwork Thu May 5 07:22:44 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 12839124 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 06959C433F5 for ; Thu, 5 May 2022 07:26:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241460AbiEEHaI (ORCPT ); Thu, 5 May 2022 03:30:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35964 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231535AbiEEHaA (ORCPT ); Thu, 5 May 2022 03:30:00 -0400 Received: from conuserg-12.nifty.com (conuserg-12.nifty.com [210.131.2.79]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C51F437027; Thu, 5 May 2022 00:26:21 -0700 (PDT) Received: from grover.sesame (133-32-177-133.west.xps.vectant.ne.jp [133.32.177.133]) (authenticated) by conuserg-12.nifty.com with ESMTP id 2457Nenx019426; Thu, 5 May 2022 16:23:58 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-12.nifty.com 2457Nenx019426 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1651735438; bh=q2lbEzTRVD+QPFvQ/TvNHXThm5Pw736ecoqXdaet6u0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Mg+Td5I/ravKpnTWe4pZIocSpNNW1nCsM6IHrKLKcAuzizHyyE4hanm6PXv8obBHe p2OgMuhQUdBaj5v+Kctpix7Kir2XgODmkfYNyqIvmopRk1jJlWZKEBGJS34pIHL6e+ tnfVPVV51mmNWSkTdKtxqlbTnkjyKLvUyz1759W9WdehN3YVwcWa/0v4wp22cia9xo keOEB3XRNSgaSDoDwev15VN29q0azLvbt24+ur7modfZXaTdiTJPxPPPhXDKpN7GOd LccaHCWLc55aTnPqAxxGZo/JLijoUQNxNnxX459GEDsUkg2UdiV1dwLC5/MfAHBkwC MLNWnIbJqlYaQ== X-Nifty-SrcIP: [133.32.177.133] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: clang-built-linux@googlegroups.com, linux-kernel@vger.kernel.org, Nicolas Schier a , Ard Biesheuvel , Luis Chamberlain , Peter Zijlstra , linuxppc-dev@lists.ozlabs.org, linux-um@lists.infradead.org, linux-s390@vger.kernel.org, Nick Desaulniers , Sami Tolvanen , Kees Cook , Masahiro Yamada Subject: [PATCH v3 15/15] kbuild: make *.mod rule robust against too long argument error Date: Thu, 5 May 2022 16:22:44 +0900 Message-Id: <20220505072244.1155033-16-masahiroy@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220505072244.1155033-1-masahiroy@kernel.org> References: <20220505072244.1155033-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Like built-in.a, the command length of the *.mod rule scales with the depth of the directory times the number of objects in the Makefile. Add $(obj)/ by the shell command (awk) instead of by Make's builtin function. In-tree modules still have some room to the limit (ARG_MAX=2097152), but this is more future-proof for big modules in a deep directory. For example, you can build i915 as a module (CONFIG_DRM_I915=m) and compare drivers/gpu/drm/i915/.i915.mod.cmd with/without this commit. The issue is more critical for external modules because the M= path can be very long as Jeff Johnson reported before [1]. [1] https://lore.kernel.org/linux-kbuild/4c02050c4e95e4cb8cc04282695f8404@codeaurora.org/ Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier --- (no changes since v2) Changes in v2: - New patch scripts/Makefile.build | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index cea48762299c..e7b3f329d443 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -266,8 +266,8 @@ $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE $(call if_changed_rule,cc_o_c) $(call cmd,force_checksrc) -cmd_mod = echo $(addprefix $(obj)/, $(call real-search, $*.o, .o, -objs -y -m)) | \ - $(AWK) -v RS='( |\n)' '!x[$$0]++' > $@ +cmd_mod = echo $(call real-search, $*.o, .o, -objs -y -m) | \ + $(AWK) -v RS='( |\n)' '!x[$$0]++ { print("$(obj)/"$$0) }' > $@ $(obj)/%.mod: FORCE $(call if_changed,mod)