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	 13b25489b6
			
		
	
	
		13b25489b6
		
	
	
	
	
		
			
			Currently, Kbuild always operates in the output directory of the kernel,
even when building external modules. This increases the risk of external
module Makefiles attempting to write to the kernel directory.
This commit switches the working directory to the external module
directory, allowing the removal of the $(KBUILD_EXTMOD)/ prefix from
some build artifacts.
The command for building external modules maintains backward
compatibility, but Makefiles that rely on working in the kernel
directory may break. In such cases, $(objtree) and $(srctree) should
be used to refer to the output and source directories of the kernel.
The appearance of the build log will change as follows:
[Before]
  $ make -C /path/to/my/linux M=/path/to/my/externel/module
  make: Entering directory '/path/to/my/linux'
    CC [M]  /path/to/my/externel/module/helloworld.o
    MODPOST /path/to/my/externel/module/Module.symvers
    CC [M]  /path/to/my/externel/module/helloworld.mod.o
    CC [M]  /path/to/my/externel/module/.module-common.o
    LD [M]  /path/to/my/externel/module/helloworld.ko
  make: Leaving directory '/path/to/my/linux'
[After]
  $ make -C /path/to/my/linux M=/path/to/my/externel/module
  make: Entering directory '/path/to/my/linux'
  make[1]: Entering directory '/path/to/my/externel/module'
    CC [M]  helloworld.o
    MODPOST Module.symvers
    CC [M]  helloworld.mod.o
    CC [M]  .module-common.o
    LD [M]  helloworld.ko
  make[1]: Leaving directory '/path/to/my/externel/module'
  make: Leaving directory '/path/to/my/linux'
Printing "Entering directory" twice is cumbersome. This will be
addressed later.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
		
	
			
		
			
				
	
	
		
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			1.9 KiB
		
	
	
	
		
			Text
		
	
	
	
	
	
			
		
		
	
	
			63 lines
		
	
	
	
		
			1.9 KiB
		
	
	
	
		
			Text
		
	
	
	
	
	
| # SPDX-License-Identifier: GPL-2.0
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| # ==========================================================================
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| # Cleaning up
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| # ==========================================================================
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| 
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| src := $(srcroot)/$(obj)
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| 
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| PHONY := __clean
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| __clean:
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| 
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| include $(srctree)/scripts/Kbuild.include
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| include $(kbuild-file)
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| 
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| # Figure out what we need to build from the various variables
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| # ==========================================================================
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| 
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| subdir-ymn := $(sort $(subdir-y) $(subdir-m) $(subdir-) \
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| 		$(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m) $(obj-))))
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| 
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| # Add subdir path
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| 
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| subdir-ymn	:= $(addprefix $(obj)/,$(subdir-ymn))
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| 
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| # build a list of files to remove, usually relative to the current
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| # directory
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| 
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| __clean-files	:= \
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| 	$(clean-files) $(targets) $(hostprogs) $(userprogs) \
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| 	$(extra-y) $(extra-m) $(extra-) \
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| 	$(always-y) $(always-m) $(always-) \
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| 	$(hostprogs-always-y) $(hostprogs-always-m) $(hostprogs-always-) \
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| 	$(userprogs-always-y) $(userprogs-always-m) $(userprogs-always-)
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| 
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| __clean-files   := $(filter-out $(no-clean-files), $(__clean-files))
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| 
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| __clean-files   := $(wildcard $(addprefix $(obj)/, $(__clean-files)))
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| 
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| # ==========================================================================
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| 
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| # To make this rule robust against "Argument list too long" error,
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| # remove $(obj)/ prefix, and restore it by a shell command.
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| quiet_cmd_clean = CLEAN   $(obj)
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|       cmd_clean = printf '$(obj)/%s ' $(patsubst $(obj)/%,%,$(__clean-files)) | xargs rm -rf
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| 
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| __clean: $(subdir-ymn)
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| ifneq ($(strip $(__clean-files)),)
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| 	$(call cmd,clean)
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| endif
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| 	@:
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| 
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| 
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| # ===========================================================================
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| # Generic stuff
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| # ===========================================================================
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| 
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| # Descending
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| # ---------------------------------------------------------------------------
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| 
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| PHONY += $(subdir-ymn)
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| $(subdir-ymn):
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| 	$(Q)$(MAKE) $(clean)=$@
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| 
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| .PHONY: $(PHONY)
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