From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: 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> In-Reply-To: <20220505072244.1155033-1-masahiroy@kernel.org> References: <20220505072244.1155033-1-masahiroy@kernel.org> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-um" Errors-To: linux-um-bounces+geert=linux-m68k.org@lists.infradead.org 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 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 --- (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) -- 2.32.0 _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um