2005-04-17 06:20:36 +08:00
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# ==========================================================================
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# Building
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# ==========================================================================
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src := $(obj)
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2006-03-06 06:14:10 +08:00
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PHONY := __build
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2005-04-17 06:20:36 +08:00
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__build:
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2007-05-29 04:47:48 +08:00
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# Init all relevant variables used in kbuild files so
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# 1) they have correct type
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# 2) they do not inherit any value from the environment
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obj-y :=
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obj-m :=
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lib-y :=
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lib-m :=
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always :=
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targets :=
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subdir-y :=
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subdir-m :=
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EXTRA_AFLAGS :=
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EXTRA_CFLAGS :=
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EXTRA_CPPFLAGS :=
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EXTRA_LDFLAGS :=
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2007-10-16 04:25:06 +08:00
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asflags-y :=
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ccflags-y :=
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cppflags-y :=
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ldflags-y :=
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2007-05-29 04:47:48 +08:00
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2009-04-19 17:04:26 +08:00
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subdir-asflags-y :=
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subdir-ccflags-y :=
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2008-02-18 17:48:20 +08:00
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# Read auto.conf if it exists, otherwise ignore
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2006-06-09 13:12:39 +08:00
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-include include/config/auto.conf
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2005-04-17 06:20:36 +08:00
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2006-01-22 20:34:15 +08:00
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include scripts/Kbuild.include
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2008-02-18 17:48:20 +08:00
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# For backward compatibility check that these variables do not change
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2007-10-15 04:26:53 +08:00
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save-cflags := $(CFLAGS)
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2005-07-26 04:26:04 +08:00
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# The filename Kbuild has precedence over Makefile
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2005-07-28 04:11:01 +08:00
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kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
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2007-10-15 04:26:53 +08:00
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kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
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include $(kbuild-file)
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# If the save-* variables changed error out
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ifeq ($(KBUILD_NOPEDANTIC),)
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ifneq ("$(save-cflags)","$(CFLAGS)")
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2011-08-15 13:07:13 +08:00
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$(error CFLAGS was changed in "$(kbuild-file)". Fix it to use ccflags-y)
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2007-10-15 04:26:53 +08:00
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endif
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endif
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2011-03-01 16:35:29 +08:00
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2005-04-17 06:20:36 +08:00
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include scripts/Makefile.lib
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ifdef host-progs
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ifneq ($(hostprogs-y),$(host-progs))
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$(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
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hostprogs-y += $(host-progs)
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endif
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endif
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2008-02-18 17:48:20 +08:00
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# Do not include host rules unless needed
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2016-05-24 06:08:25 +08:00
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ifneq ($(hostprogs-y)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),)
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2005-04-17 06:20:36 +08:00
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include scripts/Makefile.host
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endif
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ifneq ($(KBUILD_SRC),)
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# Create output directory if not already present
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_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
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# Create directories for object files if directory does not exist
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# Needed when obj-y := dir/file.o syntax is used
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_dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
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endif
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ifndef obj
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$(warning kbuild: Makefile.build is included improperly)
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endif
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# ===========================================================================
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2014-09-09 18:26:21 +08:00
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ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
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2005-04-17 06:20:36 +08:00
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lib-target := $(obj)/lib.a
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2016-01-16 03:01:22 +08:00
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obj-y += $(obj)/lib-ksyms.o
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2005-04-17 06:20:36 +08:00
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endif
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2014-09-09 18:26:21 +08:00
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ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),)
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2005-04-17 06:20:36 +08:00
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builtin-target := $(obj)/built-in.o
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endif
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2007-12-07 20:04:30 +08:00
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modorder-target := $(obj)/modules.order
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2005-04-17 06:20:36 +08:00
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# We keep a list of all modules in $(MODVERDIR)
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__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
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2007-12-07 20:04:30 +08:00
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$(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
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2005-04-17 06:20:36 +08:00
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$(subdir-ym) $(always)
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@:
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# Linus' kernel sanity checking tool
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ifneq ($(KBUILD_CHECKSRC),0)
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ifeq ($(KBUILD_CHECKSRC),2)
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quiet_cmd_force_checksrc = CHECK $<
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cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
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else
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quiet_cmd_checksrc = CHECK $<
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cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
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endif
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endif
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2008-01-22 04:31:44 +08:00
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# Do section mismatch analysis for each module/built-in.o
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ifdef CONFIG_DEBUG_SECTION_MISMATCH
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cmd_secanalysis = ; scripts/mod/modpost $@
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endif
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2005-04-17 06:20:36 +08:00
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# Compile C sources (.c)
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# ---------------------------------------------------------------------------
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# Default is built-in, unless we know otherwise
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kbuild: allow assignment to {A,C,LD}FLAGS_MODULE on the command line
It is now possible to assign options to AS, CC and LD
on the command line - which is only used when building modules.
{A,C,LD}FLAGS_MODULE was all used both in the top-level Makefile
in the arch makefiles, thus users had no way to specify
additional options to AS, CC, LD when building modules
without overriding the original value.
Introduce a new set of variables KBUILD_{A,C,LD}FLAGS_MODULE
that is used by arch specific files and free up
{A,C,LD}FLAGS_MODULE so they can be assigned on
the command line.
All arch Makefiles that used the old variables has been updated.
Note: Previously we had a MODFLAGS variable for both
AS and CC. But in favour of consistency this was dropped.
So in some cases arch Makefile has one assignmnet replaced by
two assignmnets.
Note2: MODFLAGS was not documented and is dropped
without any notice. I do not expect much/any breakage
from this.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Chen Liqin <liqin.chen@sunplusct.com>
Acked-by: Mike Frysinger <vapier@gentoo.org> [blackfin]
Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> [avr32]
Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-07-28 23:33:09 +08:00
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modkern_cflags = \
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$(if $(part-of-module), \
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$(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
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2010-07-29 01:11:27 +08:00
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$(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
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2005-04-17 06:20:36 +08:00
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quiet_modtag := $(empty) $(empty)
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2009-01-12 10:00:51 +08:00
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$(real-objs-m) : part-of-module := y
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$(real-objs-m:.o=.i) : part-of-module := y
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$(real-objs-m:.o=.s) : part-of-module := y
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$(real-objs-m:.o=.lst): part-of-module := y
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2005-04-17 06:20:36 +08:00
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$(real-objs-m) : quiet_modtag := [M]
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$(real-objs-m:.o=.i) : quiet_modtag := [M]
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$(real-objs-m:.o=.s) : quiet_modtag := [M]
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$(real-objs-m:.o=.lst): quiet_modtag := [M]
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$(obj-m) : quiet_modtag := [M]
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# Default for not multi-part modules
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2006-07-01 15:58:02 +08:00
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modname = $(basetarget)
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2005-04-17 06:20:36 +08:00
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$(multi-objs-m) : modname = $(modname-multi)
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$(multi-objs-m:.o=.i) : modname = $(modname-multi)
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$(multi-objs-m:.o=.s) : modname = $(modname-multi)
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$(multi-objs-m:.o=.lst) : modname = $(modname-multi)
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$(multi-objs-y) : modname = $(modname-multi)
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$(multi-objs-y:.o=.i) : modname = $(modname-multi)
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$(multi-objs-y:.o=.s) : modname = $(modname-multi)
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$(multi-objs-y:.o=.lst) : modname = $(modname-multi)
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quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
|
2014-02-08 16:01:15 +08:00
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cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
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2005-04-17 06:20:36 +08:00
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2007-05-06 15:23:45 +08:00
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$(obj)/%.s: $(src)/%.c FORCE
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2005-04-17 06:20:36 +08:00
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$(call if_changed_dep,cc_s_c)
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2016-04-08 10:24:47 +08:00
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quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
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cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
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2005-04-17 06:20:36 +08:00
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2007-05-06 15:23:45 +08:00
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$(obj)/%.i: $(src)/%.c FORCE
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2016-04-08 10:24:47 +08:00
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$(call if_changed_dep,cpp_i_c)
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2005-04-17 06:20:36 +08:00
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2016-11-01 09:46:19 +08:00
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# These mirror gensymtypes_S and co below, keep them in synch.
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cmd_gensymtypes_c = \
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2008-12-20 04:38:09 +08:00
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$(CPP) -D__GENKSYMS__ $(c_flags) $< | \
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2013-03-18 17:08:56 +08:00
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$(GENKSYMS) $(if $(1), -T $(2)) \
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$(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \
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2017-02-03 17:54:05 +08:00
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$(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
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2008-12-20 04:38:09 +08:00
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$(if $(KBUILD_PRESERVE),-p) \
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2010-05-25 05:07:24 +08:00
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-r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
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2008-12-20 04:38:09 +08:00
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kbuild: support for %.symtypes files
Here is a patch that adds a new -T option to genksyms for generating dumps of
the type definition that makes up the symbol version hashes. This allows to
trace modversion changes back to what caused them. The dump format is the
name of the type defined, followed by its definition (which is almost C):
s#list_head struct list_head { s#list_head * next , * prev ; }
The s#, u#, e#, and t# prefixes stand for struct, union, enum, and typedef.
The exported symbols do not define types, and thus do not have an x# prefix:
nfs4_acl_get_whotype int nfs4_acl_get_whotype ( char * , t#u32 )
The symbol type defintion of a single file can be generated with:
make fs/jbd/journal.symtypes
If KBUILD_SYMTYPES is defined, all the *.symtypes of all object files that
export symbols are generated.
The single *.symtypes files can be combined into a single file after a kernel
build with a script like the following:
for f in $(find -name '*.symtypes' | sort); do
f=${f#./}
echo "/* ${f%.symtypes}.o */"
cat $f
echo
done \
| sed -e '\:UNKNOWN:d' \
-e 's:[,;] }:}:g' \
-e 's:\([[({]\) :\1:g' \
-e 's: \([])},;]\):\1:g' \
-e 's: $::' \
$f \
| awk '
/^.#/ { if (defined[$1] == $0) {
print $1
next
}
defined[$1] = $0
}
{ print }
'
When the kernel ABI changes, diffing individual *.symtype files, or the
combined files, against each other will show which symbol changes caused the
ABI changes. This can save a tremendous amount of time.
Dump the types that make up modversions
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-05-10 02:37:30 +08:00
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quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
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2008-12-20 04:38:09 +08:00
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cmd_cc_symtypes_c = \
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set -e; \
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2016-11-01 09:46:19 +08:00
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$(call cmd_gensymtypes_c,true,$@) >/dev/null; \
|
2008-12-20 04:38:09 +08:00
|
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|
test -s $@ || rm -f $@
|
kbuild: support for %.symtypes files
Here is a patch that adds a new -T option to genksyms for generating dumps of
the type definition that makes up the symbol version hashes. This allows to
trace modversion changes back to what caused them. The dump format is the
name of the type defined, followed by its definition (which is almost C):
s#list_head struct list_head { s#list_head * next , * prev ; }
The s#, u#, e#, and t# prefixes stand for struct, union, enum, and typedef.
The exported symbols do not define types, and thus do not have an x# prefix:
nfs4_acl_get_whotype int nfs4_acl_get_whotype ( char * , t#u32 )
The symbol type defintion of a single file can be generated with:
make fs/jbd/journal.symtypes
If KBUILD_SYMTYPES is defined, all the *.symtypes of all object files that
export symbols are generated.
The single *.symtypes files can be combined into a single file after a kernel
build with a script like the following:
for f in $(find -name '*.symtypes' | sort); do
f=${f#./}
echo "/* ${f%.symtypes}.o */"
cat $f
echo
done \
| sed -e '\:UNKNOWN:d' \
-e 's:[,;] }:}:g' \
-e 's:\([[({]\) :\1:g' \
-e 's: \([])},;]\):\1:g' \
-e 's: $::' \
$f \
| awk '
/^.#/ { if (defined[$1] == $0) {
print $1
next
}
defined[$1] = $0
}
{ print }
'
When the kernel ABI changes, diffing individual *.symtype files, or the
combined files, against each other will show which symbol changes caused the
ABI changes. This can save a tremendous amount of time.
Dump the types that make up modversions
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-05-10 02:37:30 +08:00
|
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|
|
2007-05-06 15:23:45 +08:00
|
|
|
$(obj)/%.symtypes : $(src)/%.c FORCE
|
2008-12-02 06:21:01 +08:00
|
|
|
$(call cmd,cc_symtypes_c)
|
kbuild: support for %.symtypes files
Here is a patch that adds a new -T option to genksyms for generating dumps of
the type definition that makes up the symbol version hashes. This allows to
trace modversion changes back to what caused them. The dump format is the
name of the type defined, followed by its definition (which is almost C):
s#list_head struct list_head { s#list_head * next , * prev ; }
The s#, u#, e#, and t# prefixes stand for struct, union, enum, and typedef.
The exported symbols do not define types, and thus do not have an x# prefix:
nfs4_acl_get_whotype int nfs4_acl_get_whotype ( char * , t#u32 )
The symbol type defintion of a single file can be generated with:
make fs/jbd/journal.symtypes
If KBUILD_SYMTYPES is defined, all the *.symtypes of all object files that
export symbols are generated.
The single *.symtypes files can be combined into a single file after a kernel
build with a script like the following:
for f in $(find -name '*.symtypes' | sort); do
f=${f#./}
echo "/* ${f%.symtypes}.o */"
cat $f
echo
done \
| sed -e '\:UNKNOWN:d' \
-e 's:[,;] }:}:g' \
-e 's:\([[({]\) :\1:g' \
-e 's: \([])},;]\):\1:g' \
-e 's: $::' \
$f \
| awk '
/^.#/ { if (defined[$1] == $0) {
print $1
next
}
defined[$1] = $0
}
{ print }
'
When the kernel ABI changes, diffing individual *.symtype files, or the
combined files, against each other will show which symbol changes caused the
ABI changes. This can save a tremendous amount of time.
Dump the types that make up modversions
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-05-10 02:37:30 +08:00
|
|
|
|
2017-04-25 04:04:58 +08:00
|
|
|
# LLVM assembly
|
|
|
|
|
# Generate .ll files from .c
|
|
|
|
|
quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
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|
|
|
|
cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
|
|
|
|
|
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|
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|
|
$(obj)/%.ll: $(src)/%.c FORCE
|
|
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|
|
$(call if_changed_dep,cc_ll_c)
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|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
# C (.c) files
|
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|
|
# The C file is compiled and updated dependency information is generated.
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|
# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
|
|
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|
|
quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
|
|
|
|
|
|
|
|
|
|
ifndef CONFIG_MODVERSIONS
|
|
|
|
|
cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
|
|
|
|
|
|
|
|
|
|
else
|
|
|
|
|
# When module versioning is enabled the following steps are executed:
|
2009-01-15 04:38:20 +08:00
|
|
|
# o compile a .tmp_<file>.o from <file>.c
|
|
|
|
|
# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
|
|
|
|
|
# not export symbols, we just rename .tmp_<file>.o to <file>.o and
|
2005-04-17 06:20:36 +08:00
|
|
|
# are done.
|
|
|
|
|
# o otherwise, we calculate symbol versions using the good old
|
|
|
|
|
# genksyms on the preprocessed source and postprocess them in a way
|
2009-01-15 04:38:20 +08:00
|
|
|
# that they are usable as a linker script
|
|
|
|
|
# o generate <file>.o from .tmp_<file>.o using the linker to
|
|
|
|
|
# replace the unresolved symbols __crc_exported_symbol with
|
|
|
|
|
# the actual value of the checksum generated by genksyms
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2009-01-15 04:38:20 +08:00
|
|
|
cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
|
2016-11-01 09:46:19 +08:00
|
|
|
|
|
|
|
|
cmd_modversions_c = \
|
2010-05-25 05:07:24 +08:00
|
|
|
if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
|
2016-11-01 09:46:19 +08:00
|
|
|
$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
|
2010-05-25 05:07:24 +08:00
|
|
|
> $(@D)/.tmp_$(@F:.o=.ver); \
|
|
|
|
|
\
|
|
|
|
|
$(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
|
|
|
|
|
-T $(@D)/.tmp_$(@F:.o=.ver); \
|
|
|
|
|
rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
|
|
|
|
|
else \
|
|
|
|
|
mv -f $(@D)/.tmp_$(@F) $@; \
|
2005-04-17 06:20:36 +08:00
|
|
|
fi;
|
|
|
|
|
endif
|
|
|
|
|
|
ftrace: create __mcount_loc section
This patch creates a section in the kernel called "__mcount_loc".
This will hold a list of pointers to the mcount relocation for
each call site of mcount.
For example:
objdump -dr init/main.o
[...]
Disassembly of section .text:
0000000000000000 <do_one_initcall>:
0: 55 push %rbp
[...]
000000000000017b <init_post>:
17b: 55 push %rbp
17c: 48 89 e5 mov %rsp,%rbp
17f: 53 push %rbx
180: 48 83 ec 08 sub $0x8,%rsp
184: e8 00 00 00 00 callq 189 <init_post+0xe>
185: R_X86_64_PC32 mcount+0xfffffffffffffffc
[...]
We will add a section to point to each function call.
.section __mcount_loc,"a",@progbits
[...]
.quad .text + 0x185
[...]
The offset to of the mcount call site in init_post is an offset from
the start of the section, and not the start of the function init_post.
The mcount relocation is at the call site 0x185 from the start of the
.text section.
.text + 0x185 == init_post + 0xa
We need a way to add this __mcount_loc section in a way that we do not
lose the relocations after final link. The .text section here will
be attached to all other .text sections after final link and the
offsets will be meaningless. We need to keep track of where these
.text sections are.
To do this, we use the start of the first function in the section.
do_one_initcall. We can make a tmp.s file with this function as a reference
to the start of the .text section.
.section __mcount_loc,"a",@progbits
[...]
.quad do_one_initcall + 0x185
[...]
Then we can compile the tmp.s into a tmp.o
gcc -c tmp.s -o tmp.o
And link it into back into main.o.
ld -r main.o tmp.o -o tmp_main.o
mv tmp_main.o main.o
But we have a problem. What happens if the first function in a section
is not exported, and is a static function. The linker will not let
the tmp.o use it. This case exists in main.o as well.
Disassembly of section .init.text:
0000000000000000 <set_reset_devices>:
0: 55 push %rbp
1: 48 89 e5 mov %rsp,%rbp
4: e8 00 00 00 00 callq 9 <set_reset_devices+0x9>
5: R_X86_64_PC32 mcount+0xfffffffffffffffc
The first function in .init.text is a static function.
00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 t set_reset_devices
The lowercase 't' means that set_reset_devices is local and is not exported.
If we simply try to link the tmp.o with the set_reset_devices we end
up with two symbols: one local and one global.
.section __mcount_loc,"a",@progbits
.quad set_reset_devices + 0x10
00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 t set_reset_devices
U set_reset_devices
We still have an undefined reference to set_reset_devices, and if we try
to compile the kernel, we will end up with an undefined reference to
set_reset_devices, or even worst, it could be exported someplace else,
and then we will have a reference to the wrong location.
To handle this case, we make an intermediate step using objcopy.
We convert set_reset_devices into a global exported symbol before linking
it with tmp.o and set it back afterwards.
00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 T set_reset_devices
00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 T set_reset_devices
00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 t set_reset_devices
Now we have a section in main.o called __mcount_loc that we can place
somewhere in the kernel using vmlinux.ld.S and access it to convert
all these locations that call mcount into nops before starting SMP
and thus, eliminating the need to do this with kstop_machine.
Note, A well documented perl script (scripts/recordmcount.pl) is used
to do all this in one location.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-15 03:45:07 +08:00
|
|
|
ifdef CONFIG_FTRACE_MCOUNT_RECORD
|
2010-10-14 05:12:30 +08:00
|
|
|
ifdef BUILD_C_RECORDMCOUNT
|
2011-04-13 06:59:10 +08:00
|
|
|
ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
|
|
|
|
|
RECORDMCOUNT_FLAGS = -w
|
|
|
|
|
endif
|
2010-10-19 02:42:00 +08:00
|
|
|
# Due to recursion, we must skip empty.o.
|
|
|
|
|
# The empty.o file is created in the make process in order to determine
|
|
|
|
|
# the target endianness and word size. It is made before all other C
|
|
|
|
|
# files, including recordmcount.
|
ftrace: Speed up recordmcount
cmd_record_mcount is used to locate the _mcount symbols in the object
files, only the files compiled with -pg has the _mcount symbol, so, it
is only needed for such files, but the current cmd_record_mcount is used
for all of the object files, so, we need to fix it and speed it up.
Since -pg may be removed by the method used in kernel/trace/Makefile:
ORIG_CFLAGS := $(KBUILD_CFLAGS)
KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS))
Or may be removed by the method used in arch/x86/kernel/Makefile:
CFLAGS_REMOVE_file.o = -pg
So, we must check the last variable stores the compiling flags, that is
c_flags(Please refer to cmd_cc_o_c and rule_cc_o_c defined in
scripts/Makefile.build) and since the CFLAGS_REMOVE_file.o is already
filtered in _c_flags(Please refer to scripts/Makefile.lib) and _c_flags
has less symbols, therefore, we only need to check _c_flags.
---------------
Changes from v1:
o Don't touch Makefile for CONFIG_FTRACE_MCOUNT_RECORD is enough
o Use _c_flags intead of KBUILD_CFLAGS to cover CONFIG_REMOVE_file.o = -pg
(feedback from Steven Rostedt <rostedt@goodmis.org>)
Acked-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
LKML-Reference: <3dc8cddf022eb7024f9f2cf857529a15bee8999a.1288196498.git.wuzhangjin@gmail.com>
[ changed if [ .. == .. ] to if [ .. = .. ] to handle dash environments ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-28 00:24:34 +08:00
|
|
|
sub_cmd_record_mcount = \
|
|
|
|
|
if [ $(@) != "scripts/mod/empty.o" ]; then \
|
2011-04-13 06:59:10 +08:00
|
|
|
$(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
|
ftrace: Speed up recordmcount
cmd_record_mcount is used to locate the _mcount symbols in the object
files, only the files compiled with -pg has the _mcount symbol, so, it
is only needed for such files, but the current cmd_record_mcount is used
for all of the object files, so, we need to fix it and speed it up.
Since -pg may be removed by the method used in kernel/trace/Makefile:
ORIG_CFLAGS := $(KBUILD_CFLAGS)
KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS))
Or may be removed by the method used in arch/x86/kernel/Makefile:
CFLAGS_REMOVE_file.o = -pg
So, we must check the last variable stores the compiling flags, that is
c_flags(Please refer to cmd_cc_o_c and rule_cc_o_c defined in
scripts/Makefile.build) and since the CFLAGS_REMOVE_file.o is already
filtered in _c_flags(Please refer to scripts/Makefile.lib) and _c_flags
has less symbols, therefore, we only need to check _c_flags.
---------------
Changes from v1:
o Don't touch Makefile for CONFIG_FTRACE_MCOUNT_RECORD is enough
o Use _c_flags intead of KBUILD_CFLAGS to cover CONFIG_REMOVE_file.o = -pg
(feedback from Steven Rostedt <rostedt@goodmis.org>)
Acked-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
LKML-Reference: <3dc8cddf022eb7024f9f2cf857529a15bee8999a.1288196498.git.wuzhangjin@gmail.com>
[ changed if [ .. == .. ] to if [ .. = .. ] to handle dash environments ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-28 00:24:34 +08:00
|
|
|
fi;
|
2011-05-17 21:36:46 +08:00
|
|
|
recordmcount_source := $(srctree)/scripts/recordmcount.c \
|
|
|
|
|
$(srctree)/scripts/recordmcount.h
|
2010-10-14 05:12:30 +08:00
|
|
|
else
|
ftrace: Speed up recordmcount
cmd_record_mcount is used to locate the _mcount symbols in the object
files, only the files compiled with -pg has the _mcount symbol, so, it
is only needed for such files, but the current cmd_record_mcount is used
for all of the object files, so, we need to fix it and speed it up.
Since -pg may be removed by the method used in kernel/trace/Makefile:
ORIG_CFLAGS := $(KBUILD_CFLAGS)
KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS))
Or may be removed by the method used in arch/x86/kernel/Makefile:
CFLAGS_REMOVE_file.o = -pg
So, we must check the last variable stores the compiling flags, that is
c_flags(Please refer to cmd_cc_o_c and rule_cc_o_c defined in
scripts/Makefile.build) and since the CFLAGS_REMOVE_file.o is already
filtered in _c_flags(Please refer to scripts/Makefile.lib) and _c_flags
has less symbols, therefore, we only need to check _c_flags.
---------------
Changes from v1:
o Don't touch Makefile for CONFIG_FTRACE_MCOUNT_RECORD is enough
o Use _c_flags intead of KBUILD_CFLAGS to cover CONFIG_REMOVE_file.o = -pg
(feedback from Steven Rostedt <rostedt@goodmis.org>)
Acked-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
LKML-Reference: <3dc8cddf022eb7024f9f2cf857529a15bee8999a.1288196498.git.wuzhangjin@gmail.com>
[ changed if [ .. == .. ] to if [ .. = .. ] to handle dash environments ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-28 00:24:34 +08:00
|
|
|
sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
|
2009-11-20 20:34:31 +08:00
|
|
|
"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
|
2008-10-30 03:30:26 +08:00
|
|
|
"$(if $(CONFIG_64BIT),64,32)" \
|
2010-08-11 02:39:20 +08:00
|
|
|
"$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
|
|
|
|
|
"$(LD)" "$(NM)" "$(RM)" "$(MV)" \
|
2009-01-12 10:00:51 +08:00
|
|
|
"$(if $(part-of-module),1,0)" "$(@)";
|
2011-05-17 21:36:46 +08:00
|
|
|
recordmcount_source := $(srctree)/scripts/recordmcount.pl
|
ftrace: create __mcount_loc section
This patch creates a section in the kernel called "__mcount_loc".
This will hold a list of pointers to the mcount relocation for
each call site of mcount.
For example:
objdump -dr init/main.o
[...]
Disassembly of section .text:
0000000000000000 <do_one_initcall>:
0: 55 push %rbp
[...]
000000000000017b <init_post>:
17b: 55 push %rbp
17c: 48 89 e5 mov %rsp,%rbp
17f: 53 push %rbx
180: 48 83 ec 08 sub $0x8,%rsp
184: e8 00 00 00 00 callq 189 <init_post+0xe>
185: R_X86_64_PC32 mcount+0xfffffffffffffffc
[...]
We will add a section to point to each function call.
.section __mcount_loc,"a",@progbits
[...]
.quad .text + 0x185
[...]
The offset to of the mcount call site in init_post is an offset from
the start of the section, and not the start of the function init_post.
The mcount relocation is at the call site 0x185 from the start of the
.text section.
.text + 0x185 == init_post + 0xa
We need a way to add this __mcount_loc section in a way that we do not
lose the relocations after final link. The .text section here will
be attached to all other .text sections after final link and the
offsets will be meaningless. We need to keep track of where these
.text sections are.
To do this, we use the start of the first function in the section.
do_one_initcall. We can make a tmp.s file with this function as a reference
to the start of the .text section.
.section __mcount_loc,"a",@progbits
[...]
.quad do_one_initcall + 0x185
[...]
Then we can compile the tmp.s into a tmp.o
gcc -c tmp.s -o tmp.o
And link it into back into main.o.
ld -r main.o tmp.o -o tmp_main.o
mv tmp_main.o main.o
But we have a problem. What happens if the first function in a section
is not exported, and is a static function. The linker will not let
the tmp.o use it. This case exists in main.o as well.
Disassembly of section .init.text:
0000000000000000 <set_reset_devices>:
0: 55 push %rbp
1: 48 89 e5 mov %rsp,%rbp
4: e8 00 00 00 00 callq 9 <set_reset_devices+0x9>
5: R_X86_64_PC32 mcount+0xfffffffffffffffc
The first function in .init.text is a static function.
00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 t set_reset_devices
The lowercase 't' means that set_reset_devices is local and is not exported.
If we simply try to link the tmp.o with the set_reset_devices we end
up with two symbols: one local and one global.
.section __mcount_loc,"a",@progbits
.quad set_reset_devices + 0x10
00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 t set_reset_devices
U set_reset_devices
We still have an undefined reference to set_reset_devices, and if we try
to compile the kernel, we will end up with an undefined reference to
set_reset_devices, or even worst, it could be exported someplace else,
and then we will have a reference to the wrong location.
To handle this case, we make an intermediate step using objcopy.
We convert set_reset_devices into a global exported symbol before linking
it with tmp.o and set it back afterwards.
00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 T set_reset_devices
00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 T set_reset_devices
00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 t set_reset_devices
Now we have a section in main.o called __mcount_loc that we can place
somewhere in the kernel using vmlinux.ld.S and access it to convert
all these locations that call mcount into nops before starting SMP
and thus, eliminating the need to do this with kstop_machine.
Note, A well documented perl script (scripts/recordmcount.pl) is used
to do all this in one location.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-15 03:45:07 +08:00
|
|
|
endif
|
2015-01-09 20:06:33 +08:00
|
|
|
cmd_record_mcount = \
|
|
|
|
|
if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \
|
|
|
|
|
"$(CC_FLAGS_FTRACE)" ]; then \
|
ftrace: Speed up recordmcount
cmd_record_mcount is used to locate the _mcount symbols in the object
files, only the files compiled with -pg has the _mcount symbol, so, it
is only needed for such files, but the current cmd_record_mcount is used
for all of the object files, so, we need to fix it and speed it up.
Since -pg may be removed by the method used in kernel/trace/Makefile:
ORIG_CFLAGS := $(KBUILD_CFLAGS)
KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS))
Or may be removed by the method used in arch/x86/kernel/Makefile:
CFLAGS_REMOVE_file.o = -pg
So, we must check the last variable stores the compiling flags, that is
c_flags(Please refer to cmd_cc_o_c and rule_cc_o_c defined in
scripts/Makefile.build) and since the CFLAGS_REMOVE_file.o is already
filtered in _c_flags(Please refer to scripts/Makefile.lib) and _c_flags
has less symbols, therefore, we only need to check _c_flags.
---------------
Changes from v1:
o Don't touch Makefile for CONFIG_FTRACE_MCOUNT_RECORD is enough
o Use _c_flags intead of KBUILD_CFLAGS to cover CONFIG_REMOVE_file.o = -pg
(feedback from Steven Rostedt <rostedt@goodmis.org>)
Acked-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
LKML-Reference: <3dc8cddf022eb7024f9f2cf857529a15bee8999a.1288196498.git.wuzhangjin@gmail.com>
[ changed if [ .. == .. ] to if [ .. = .. ] to handle dash environments ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-28 00:24:34 +08:00
|
|
|
$(sub_cmd_record_mcount) \
|
|
|
|
|
fi;
|
2010-10-14 05:12:30 +08:00
|
|
|
endif
|
ftrace: create __mcount_loc section
This patch creates a section in the kernel called "__mcount_loc".
This will hold a list of pointers to the mcount relocation for
each call site of mcount.
For example:
objdump -dr init/main.o
[...]
Disassembly of section .text:
0000000000000000 <do_one_initcall>:
0: 55 push %rbp
[...]
000000000000017b <init_post>:
17b: 55 push %rbp
17c: 48 89 e5 mov %rsp,%rbp
17f: 53 push %rbx
180: 48 83 ec 08 sub $0x8,%rsp
184: e8 00 00 00 00 callq 189 <init_post+0xe>
185: R_X86_64_PC32 mcount+0xfffffffffffffffc
[...]
We will add a section to point to each function call.
.section __mcount_loc,"a",@progbits
[...]
.quad .text + 0x185
[...]
The offset to of the mcount call site in init_post is an offset from
the start of the section, and not the start of the function init_post.
The mcount relocation is at the call site 0x185 from the start of the
.text section.
.text + 0x185 == init_post + 0xa
We need a way to add this __mcount_loc section in a way that we do not
lose the relocations after final link. The .text section here will
be attached to all other .text sections after final link and the
offsets will be meaningless. We need to keep track of where these
.text sections are.
To do this, we use the start of the first function in the section.
do_one_initcall. We can make a tmp.s file with this function as a reference
to the start of the .text section.
.section __mcount_loc,"a",@progbits
[...]
.quad do_one_initcall + 0x185
[...]
Then we can compile the tmp.s into a tmp.o
gcc -c tmp.s -o tmp.o
And link it into back into main.o.
ld -r main.o tmp.o -o tmp_main.o
mv tmp_main.o main.o
But we have a problem. What happens if the first function in a section
is not exported, and is a static function. The linker will not let
the tmp.o use it. This case exists in main.o as well.
Disassembly of section .init.text:
0000000000000000 <set_reset_devices>:
0: 55 push %rbp
1: 48 89 e5 mov %rsp,%rbp
4: e8 00 00 00 00 callq 9 <set_reset_devices+0x9>
5: R_X86_64_PC32 mcount+0xfffffffffffffffc
The first function in .init.text is a static function.
00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 t set_reset_devices
The lowercase 't' means that set_reset_devices is local and is not exported.
If we simply try to link the tmp.o with the set_reset_devices we end
up with two symbols: one local and one global.
.section __mcount_loc,"a",@progbits
.quad set_reset_devices + 0x10
00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 t set_reset_devices
U set_reset_devices
We still have an undefined reference to set_reset_devices, and if we try
to compile the kernel, we will end up with an undefined reference to
set_reset_devices, or even worst, it could be exported someplace else,
and then we will have a reference to the wrong location.
To handle this case, we make an intermediate step using objcopy.
We convert set_reset_devices into a global exported symbol before linking
it with tmp.o and set it back afterwards.
00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 T set_reset_devices
00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 T set_reset_devices
00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 t set_reset_devices
Now we have a section in main.o called __mcount_loc that we can place
somewhere in the kernel using vmlinux.ld.S and access it to convert
all these locations that call mcount into nops before starting SMP
and thus, eliminating the need to do this with kstop_machine.
Note, A well documented perl script (scripts/recordmcount.pl) is used
to do all this in one location.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-15 03:45:07 +08:00
|
|
|
|
2016-02-29 12:22:42 +08:00
|
|
|
ifdef CONFIG_STACK_VALIDATION
|
2016-03-04 01:39:30 +08:00
|
|
|
ifneq ($(SKIP_STACK_VALIDATION),1)
|
2016-02-29 12:22:42 +08:00
|
|
|
|
|
|
|
|
__objtool_obj := $(objtree)/tools/objtool/objtool
|
|
|
|
|
|
|
|
|
|
objtool_args = check
|
|
|
|
|
ifndef CONFIG_FRAME_POINTER
|
|
|
|
|
objtool_args += --no-fp
|
|
|
|
|
endif
|
2017-07-25 07:34:14 +08:00
|
|
|
ifdef CONFIG_GCOV_KERNEL
|
|
|
|
|
objtool_args += --no-unreachable
|
|
|
|
|
endif
|
2016-02-29 12:22:42 +08:00
|
|
|
|
|
|
|
|
# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
|
|
|
|
|
# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
|
|
|
|
|
# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
|
|
|
|
|
cmd_objtool = $(if $(patsubst y%,, \
|
|
|
|
|
$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
|
|
|
|
|
$(__objtool_obj) $(objtool_args) "$(@)";)
|
|
|
|
|
objtool_obj = $(if $(patsubst y%,, \
|
|
|
|
|
$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
|
|
|
|
|
$(__objtool_obj))
|
|
|
|
|
|
2016-03-04 01:39:30 +08:00
|
|
|
endif # SKIP_STACK_VALIDATION
|
2016-02-29 12:22:42 +08:00
|
|
|
endif # CONFIG_STACK_VALIDATION
|
|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
define rule_cc_o_c
|
2006-01-30 17:04:27 +08:00
|
|
|
$(call echo-cmd,checksrc) $(cmd_checksrc) \
|
2016-02-18 04:50:06 +08:00
|
|
|
$(call cmd_and_fixdep,cc_o_c) \
|
2016-11-01 09:46:19 +08:00
|
|
|
$(cmd_modversions_c) \
|
2017-04-21 23:16:20 +08:00
|
|
|
$(call echo-cmd,objtool) $(cmd_objtool) \
|
2016-02-18 04:50:06 +08:00
|
|
|
$(call echo-cmd,record_mcount) $(cmd_record_mcount)
|
2005-04-17 06:20:36 +08:00
|
|
|
endef
|
|
|
|
|
|
2016-02-29 12:22:42 +08:00
|
|
|
define rule_as_o_S
|
2016-02-18 04:50:06 +08:00
|
|
|
$(call cmd_and_fixdep,as_o_S) \
|
2016-11-01 09:46:19 +08:00
|
|
|
$(cmd_modversions_S) \
|
2017-04-21 23:16:20 +08:00
|
|
|
$(call echo-cmd,objtool) $(cmd_objtool)
|
2016-02-29 12:22:42 +08:00
|
|
|
endef
|
|
|
|
|
|
2016-01-22 06:07:24 +08:00
|
|
|
# List module undefined symbols (or empty line if not enabled)
|
|
|
|
|
ifdef CONFIG_TRIM_UNUSED_KSYMS
|
|
|
|
|
cmd_undef_syms = $(NM) $@ | sed -n 's/^ \+U //p' | xargs echo
|
|
|
|
|
else
|
|
|
|
|
cmd_undef_syms = echo
|
|
|
|
|
endif
|
|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
# Built-in and composite module parts
|
2016-02-29 12:22:42 +08:00
|
|
|
$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE
|
2005-04-17 06:20:36 +08:00
|
|
|
$(call cmd,force_checksrc)
|
|
|
|
|
$(call if_changed_rule,cc_o_c)
|
|
|
|
|
|
|
|
|
|
# Single-part modules are special since we need to mark them in $(MODVERDIR)
|
|
|
|
|
|
2016-02-29 12:22:42 +08:00
|
|
|
$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE
|
2005-04-17 06:20:36 +08:00
|
|
|
$(call cmd,force_checksrc)
|
|
|
|
|
$(call if_changed_rule,cc_o_c)
|
2016-01-22 06:07:24 +08:00
|
|
|
@{ echo $(@:.o=.ko); echo $@; \
|
|
|
|
|
$(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
|
quiet_cmd_cc_lst_c = MKLST $@
|
|
|
|
|
cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
|
|
|
|
|
$(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
|
|
|
|
|
System.map $(OBJDUMP) > $@
|
|
|
|
|
|
2007-05-06 15:23:45 +08:00
|
|
|
$(obj)/%.lst: $(src)/%.c FORCE
|
2005-04-17 06:20:36 +08:00
|
|
|
$(call if_changed_dep,cc_lst_c)
|
|
|
|
|
|
|
|
|
|
# Compile assembler sources (.S)
|
|
|
|
|
# ---------------------------------------------------------------------------
|
|
|
|
|
|
2010-07-29 01:11:27 +08:00
|
|
|
modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
|
2005-04-17 06:20:36 +08:00
|
|
|
|
kbuild: allow assignment to {A,C,LD}FLAGS_MODULE on the command line
It is now possible to assign options to AS, CC and LD
on the command line - which is only used when building modules.
{A,C,LD}FLAGS_MODULE was all used both in the top-level Makefile
in the arch makefiles, thus users had no way to specify
additional options to AS, CC, LD when building modules
without overriding the original value.
Introduce a new set of variables KBUILD_{A,C,LD}FLAGS_MODULE
that is used by arch specific files and free up
{A,C,LD}FLAGS_MODULE so they can be assigned on
the command line.
All arch Makefiles that used the old variables has been updated.
Note: Previously we had a MODFLAGS variable for both
AS and CC. But in favour of consistency this was dropped.
So in some cases arch Makefile has one assignmnet replaced by
two assignmnets.
Note2: MODFLAGS was not documented and is dropped
without any notice. I do not expect much/any breakage
from this.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Chen Liqin <liqin.chen@sunplusct.com>
Acked-by: Mike Frysinger <vapier@gentoo.org> [blackfin]
Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> [avr32]
Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-07-28 23:33:09 +08:00
|
|
|
$(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
|
|
|
|
|
$(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2016-11-01 09:46:19 +08:00
|
|
|
# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
|
|
|
|
|
# or a file that it includes, in order to get versioned symbols. We build a
|
|
|
|
|
# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
|
|
|
|
|
# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
|
|
|
|
|
#
|
|
|
|
|
# This is convoluted. The .S file must first be preprocessed to run guards and
|
|
|
|
|
# expand names, then the resulting exports must be constructed into plain
|
|
|
|
|
# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
|
|
|
|
|
# to make the genksyms input.
|
|
|
|
|
#
|
|
|
|
|
# These mirror gensymtypes_c and co above, keep them in synch.
|
|
|
|
|
cmd_gensymtypes_S = \
|
|
|
|
|
(echo "\#include <linux/kernel.h>" ; \
|
|
|
|
|
echo "\#include <asm/asm-prototypes.h>" ; \
|
|
|
|
|
$(CPP) $(a_flags) $< | \
|
2016-11-09 12:34:05 +08:00
|
|
|
grep "\<___EXPORT_SYMBOL\>" | \
|
|
|
|
|
sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \
|
2016-11-01 09:46:19 +08:00
|
|
|
$(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \
|
|
|
|
|
$(GENKSYMS) $(if $(1), -T $(2)) \
|
|
|
|
|
$(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \
|
2017-02-03 17:54:05 +08:00
|
|
|
$(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
|
2016-11-01 09:46:19 +08:00
|
|
|
$(if $(KBUILD_PRESERVE),-p) \
|
|
|
|
|
-r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
|
|
|
|
|
|
|
|
|
|
quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
|
|
|
|
|
cmd_cc_symtypes_S = \
|
|
|
|
|
set -e; \
|
|
|
|
|
$(call cmd_gensymtypes_S,true,$@) >/dev/null; \
|
|
|
|
|
test -s $@ || rm -f $@
|
|
|
|
|
|
|
|
|
|
$(obj)/%.symtypes : $(src)/%.S FORCE
|
|
|
|
|
$(call cmd,cc_symtypes_S)
|
|
|
|
|
|
|
|
|
|
|
2016-04-08 10:24:48 +08:00
|
|
|
quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
|
|
|
|
|
cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2007-05-06 15:23:45 +08:00
|
|
|
$(obj)/%.s: $(src)/%.S FORCE
|
2016-04-08 10:24:48 +08:00
|
|
|
$(call if_changed_dep,cpp_s_S)
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
|
quiet_cmd_as_o_S = AS $(quiet_modtag) $@
|
2016-11-01 09:46:19 +08:00
|
|
|
|
|
|
|
|
ifndef CONFIG_MODVERSIONS
|
|
|
|
|
cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
|
|
|
|
|
|
|
|
|
|
else
|
|
|
|
|
|
|
|
|
|
ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h)
|
|
|
|
|
|
|
|
|
|
ifeq ($(ASM_PROTOTYPES),)
|
|
|
|
|
cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
|
|
|
|
|
|
|
|
|
|
else
|
|
|
|
|
|
|
|
|
|
# versioning matches the C process described above, with difference that
|
|
|
|
|
# we parse asm-prototypes.h C header to get function definitions.
|
|
|
|
|
|
|
|
|
|
cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $<
|
|
|
|
|
|
|
|
|
|
cmd_modversions_S = \
|
|
|
|
|
if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
|
|
|
|
|
$(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
|
|
|
|
|
> $(@D)/.tmp_$(@F:.o=.ver); \
|
|
|
|
|
\
|
|
|
|
|
$(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
|
|
|
|
|
-T $(@D)/.tmp_$(@F:.o=.ver); \
|
|
|
|
|
rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
|
|
|
|
|
else \
|
|
|
|
|
mv -f $(@D)/.tmp_$(@F) $@; \
|
|
|
|
|
fi;
|
|
|
|
|
endif
|
|
|
|
|
endif
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2016-02-29 12:22:42 +08:00
|
|
|
$(obj)/%.o: $(src)/%.S $(objtool_obj) FORCE
|
|
|
|
|
$(call if_changed_rule,as_o_S)
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
|
targets += $(real-objs-y) $(real-objs-m) $(lib-y)
|
|
|
|
|
targets += $(extra-y) $(MAKECMDGOALS) $(always)
|
|
|
|
|
|
|
|
|
|
# Linker scripts preprocessor (.lds.S -> .lds)
|
|
|
|
|
# ---------------------------------------------------------------------------
|
|
|
|
|
quiet_cmd_cpp_lds_S = LDS $@
|
2009-09-20 18:28:22 +08:00
|
|
|
cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
|
2009-09-21 06:14:12 +08:00
|
|
|
-D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2007-05-06 15:23:45 +08:00
|
|
|
$(obj)/%.lds: $(src)/%.lds.S FORCE
|
2005-04-17 06:20:36 +08:00
|
|
|
$(call if_changed_dep,cpp_lds_S)
|
|
|
|
|
|
2012-09-22 06:31:13 +08:00
|
|
|
# ASN.1 grammar
|
|
|
|
|
# ---------------------------------------------------------------------------
|
|
|
|
|
quiet_cmd_asn1_compiler = ASN.1 $@
|
|
|
|
|
cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
|
|
|
|
|
$(subst .h,.c,$@) $(subst .c,.h,$@)
|
|
|
|
|
|
|
|
|
|
.PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h
|
|
|
|
|
|
|
|
|
|
$(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
|
|
|
|
|
$(call cmd,asn1_compiler)
|
|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
# Build the compiled-in targets
|
|
|
|
|
# ---------------------------------------------------------------------------
|
|
|
|
|
|
|
|
|
|
# To build objects in subdirs, we need to descend into the directories
|
|
|
|
|
$(sort $(subdir-obj-y)): $(subdir-ym) ;
|
|
|
|
|
|
|
|
|
|
#
|
|
|
|
|
# Rule to compile a set of .o files into one .o file
|
|
|
|
|
#
|
|
|
|
|
ifdef builtin-target
|
kbuild: allow architectures to use thin archives instead of ld -r
ld -r is an incremental link used to create built-in.o files in build
subdirectories. It produces relocatable object files containing all
its input files, and these are are then pulled together and relocated
in the final link. Aside from the bloat, this constrains the final
link relocations, which has bitten large powerpc builds with
unresolvable relocations in the final link.
Alan Modra has recommended the kernel use thin archives for linking.
This is an alternative and means that the linker has more information
available to it when it links the kernel.
This patch enables a config option architectures can select, which
causes all built-in.o files to be built as thin archives. built-in.o
files in subdirectories do not get symbol table or index attached,
which improves speed and size. The final link pass creates a
built-in.o archive in the root output directory which includes the
symbol table and index. The linker then uses takes this file to link.
The --whole-archive linker option is required, because the linker now
has visibility to every individual object file, and it will otherwise
just completely avoid including those without external references
(consider a file with EXPORT_SYMBOL or initcall or hardware exceptions
as its only entry points). The traditional built works "by luck" as
built-in.o files are large enough that they're going to get external
references. However this optimisation is unpredictable for the kernel
(due to above external references), ineffective at culling unused, and
costly because the .o files have to be searched for references.
Superior alternatives for link-time culling should be used instead.
Build characteristics for inclink vs thinarc, on a small powerpc64le
pseries VM with a modest .config:
inclink thinarc
sizes
vmlinux 15 618 680 15 625 028
sum of all built-in.o 56 091 808 1 054 334
sum excluding root built-in.o 151 430
find -name built-in.o | xargs rm ; time make vmlinux
real 22.772s 21.143s
user 13.280s 13.430s
sys 4.310s 2.750s
- Final kernel pulled in only about 6K more, which shows how
ineffective the object file culling is.
- Build performance looks improved due to less pagecache activity.
On IO constrained systems it could be a bigger win.
- Build size saving is significant.
Side note, the toochain understands archives, so there's some tricks,
$ ar t built-in.o # list all files you linked with
$ size built-in.o # and their sizes
$ objdump -d built-in.o # disassembly (unrelocated) with filenames
Implementation by sfr, minor tweaks by npiggin.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-08-24 20:29:19 +08:00
|
|
|
|
|
|
|
|
ifdef CONFIG_THIN_ARCHIVES
|
2017-06-09 13:24:14 +08:00
|
|
|
cmd_make_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
|
|
|
|
|
cmd_make_empty_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
|
kbuild: allow architectures to use thin archives instead of ld -r
ld -r is an incremental link used to create built-in.o files in build
subdirectories. It produces relocatable object files containing all
its input files, and these are are then pulled together and relocated
in the final link. Aside from the bloat, this constrains the final
link relocations, which has bitten large powerpc builds with
unresolvable relocations in the final link.
Alan Modra has recommended the kernel use thin archives for linking.
This is an alternative and means that the linker has more information
available to it when it links the kernel.
This patch enables a config option architectures can select, which
causes all built-in.o files to be built as thin archives. built-in.o
files in subdirectories do not get symbol table or index attached,
which improves speed and size. The final link pass creates a
built-in.o archive in the root output directory which includes the
symbol table and index. The linker then uses takes this file to link.
The --whole-archive linker option is required, because the linker now
has visibility to every individual object file, and it will otherwise
just completely avoid including those without external references
(consider a file with EXPORT_SYMBOL or initcall or hardware exceptions
as its only entry points). The traditional built works "by luck" as
built-in.o files are large enough that they're going to get external
references. However this optimisation is unpredictable for the kernel
(due to above external references), ineffective at culling unused, and
costly because the .o files have to be searched for references.
Superior alternatives for link-time culling should be used instead.
Build characteristics for inclink vs thinarc, on a small powerpc64le
pseries VM with a modest .config:
inclink thinarc
sizes
vmlinux 15 618 680 15 625 028
sum of all built-in.o 56 091 808 1 054 334
sum excluding root built-in.o 151 430
find -name built-in.o | xargs rm ; time make vmlinux
real 22.772s 21.143s
user 13.280s 13.430s
sys 4.310s 2.750s
- Final kernel pulled in only about 6K more, which shows how
ineffective the object file culling is.
- Build performance looks improved due to less pagecache activity.
On IO constrained systems it could be a bigger win.
- Build size saving is significant.
Side note, the toochain understands archives, so there's some tricks,
$ ar t built-in.o # list all files you linked with
$ size built-in.o # and their sizes
$ objdump -d built-in.o # disassembly (unrelocated) with filenames
Implementation by sfr, minor tweaks by npiggin.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-08-24 20:29:19 +08:00
|
|
|
quiet_cmd_link_o_target = AR $@
|
|
|
|
|
else
|
|
|
|
|
cmd_make_builtin = $(LD) $(ld_flags) -r -o
|
|
|
|
|
cmd_make_empty_builtin = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS)
|
|
|
|
|
quiet_cmd_link_o_target = LD $@
|
|
|
|
|
endif
|
|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
# If the list of objects to link is empty, just create an empty built-in.o
|
|
|
|
|
cmd_link_o_target = $(if $(strip $(obj-y)),\
|
kbuild: allow architectures to use thin archives instead of ld -r
ld -r is an incremental link used to create built-in.o files in build
subdirectories. It produces relocatable object files containing all
its input files, and these are are then pulled together and relocated
in the final link. Aside from the bloat, this constrains the final
link relocations, which has bitten large powerpc builds with
unresolvable relocations in the final link.
Alan Modra has recommended the kernel use thin archives for linking.
This is an alternative and means that the linker has more information
available to it when it links the kernel.
This patch enables a config option architectures can select, which
causes all built-in.o files to be built as thin archives. built-in.o
files in subdirectories do not get symbol table or index attached,
which improves speed and size. The final link pass creates a
built-in.o archive in the root output directory which includes the
symbol table and index. The linker then uses takes this file to link.
The --whole-archive linker option is required, because the linker now
has visibility to every individual object file, and it will otherwise
just completely avoid including those without external references
(consider a file with EXPORT_SYMBOL or initcall or hardware exceptions
as its only entry points). The traditional built works "by luck" as
built-in.o files are large enough that they're going to get external
references. However this optimisation is unpredictable for the kernel
(due to above external references), ineffective at culling unused, and
costly because the .o files have to be searched for references.
Superior alternatives for link-time culling should be used instead.
Build characteristics for inclink vs thinarc, on a small powerpc64le
pseries VM with a modest .config:
inclink thinarc
sizes
vmlinux 15 618 680 15 625 028
sum of all built-in.o 56 091 808 1 054 334
sum excluding root built-in.o 151 430
find -name built-in.o | xargs rm ; time make vmlinux
real 22.772s 21.143s
user 13.280s 13.430s
sys 4.310s 2.750s
- Final kernel pulled in only about 6K more, which shows how
ineffective the object file culling is.
- Build performance looks improved due to less pagecache activity.
On IO constrained systems it could be a bigger win.
- Build size saving is significant.
Side note, the toochain understands archives, so there's some tricks,
$ ar t built-in.o # list all files you linked with
$ size built-in.o # and their sizes
$ objdump -d built-in.o # disassembly (unrelocated) with filenames
Implementation by sfr, minor tweaks by npiggin.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-08-24 20:29:19 +08:00
|
|
|
$(cmd_make_builtin) $@ $(filter $(obj-y), $^) \
|
2008-01-22 04:31:44 +08:00
|
|
|
$(cmd_secanalysis),\
|
kbuild: allow architectures to use thin archives instead of ld -r
ld -r is an incremental link used to create built-in.o files in build
subdirectories. It produces relocatable object files containing all
its input files, and these are are then pulled together and relocated
in the final link. Aside from the bloat, this constrains the final
link relocations, which has bitten large powerpc builds with
unresolvable relocations in the final link.
Alan Modra has recommended the kernel use thin archives for linking.
This is an alternative and means that the linker has more information
available to it when it links the kernel.
This patch enables a config option architectures can select, which
causes all built-in.o files to be built as thin archives. built-in.o
files in subdirectories do not get symbol table or index attached,
which improves speed and size. The final link pass creates a
built-in.o archive in the root output directory which includes the
symbol table and index. The linker then uses takes this file to link.
The --whole-archive linker option is required, because the linker now
has visibility to every individual object file, and it will otherwise
just completely avoid including those without external references
(consider a file with EXPORT_SYMBOL or initcall or hardware exceptions
as its only entry points). The traditional built works "by luck" as
built-in.o files are large enough that they're going to get external
references. However this optimisation is unpredictable for the kernel
(due to above external references), ineffective at culling unused, and
costly because the .o files have to be searched for references.
Superior alternatives for link-time culling should be used instead.
Build characteristics for inclink vs thinarc, on a small powerpc64le
pseries VM with a modest .config:
inclink thinarc
sizes
vmlinux 15 618 680 15 625 028
sum of all built-in.o 56 091 808 1 054 334
sum excluding root built-in.o 151 430
find -name built-in.o | xargs rm ; time make vmlinux
real 22.772s 21.143s
user 13.280s 13.430s
sys 4.310s 2.750s
- Final kernel pulled in only about 6K more, which shows how
ineffective the object file culling is.
- Build performance looks improved due to less pagecache activity.
On IO constrained systems it could be a bigger win.
- Build size saving is significant.
Side note, the toochain understands archives, so there's some tricks,
$ ar t built-in.o # list all files you linked with
$ size built-in.o # and their sizes
$ objdump -d built-in.o # disassembly (unrelocated) with filenames
Implementation by sfr, minor tweaks by npiggin.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-08-24 20:29:19 +08:00
|
|
|
$(cmd_make_empty_builtin) $@)
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
|
$(builtin-target): $(obj-y) FORCE
|
|
|
|
|
$(call if_changed,link_o_target)
|
|
|
|
|
|
|
|
|
|
targets += $(builtin-target)
|
|
|
|
|
endif # builtin-target
|
|
|
|
|
|
2007-12-07 20:04:30 +08:00
|
|
|
#
|
|
|
|
|
# Rule to create modules.order file
|
|
|
|
|
#
|
|
|
|
|
# Create commands to either record .ko file or cat modules.order from
|
|
|
|
|
# a subdirectory
|
|
|
|
|
modorder-cmds = \
|
|
|
|
|
$(foreach m, $(modorder), \
|
|
|
|
|
$(if $(filter %/modules.order, $m), \
|
|
|
|
|
cat $m;, echo kernel/$m;))
|
|
|
|
|
|
|
|
|
|
$(modorder-target): $(subdir-ym) FORCE
|
|
|
|
|
$(Q)(cat /dev/null; $(modorder-cmds)) > $@
|
|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
#
|
|
|
|
|
# Rule to compile a set of .o files into one .a file
|
|
|
|
|
#
|
|
|
|
|
ifdef lib-target
|
|
|
|
|
quiet_cmd_link_l_target = AR $@
|
kbuild: allow architectures to use thin archives instead of ld -r
ld -r is an incremental link used to create built-in.o files in build
subdirectories. It produces relocatable object files containing all
its input files, and these are are then pulled together and relocated
in the final link. Aside from the bloat, this constrains the final
link relocations, which has bitten large powerpc builds with
unresolvable relocations in the final link.
Alan Modra has recommended the kernel use thin archives for linking.
This is an alternative and means that the linker has more information
available to it when it links the kernel.
This patch enables a config option architectures can select, which
causes all built-in.o files to be built as thin archives. built-in.o
files in subdirectories do not get symbol table or index attached,
which improves speed and size. The final link pass creates a
built-in.o archive in the root output directory which includes the
symbol table and index. The linker then uses takes this file to link.
The --whole-archive linker option is required, because the linker now
has visibility to every individual object file, and it will otherwise
just completely avoid including those without external references
(consider a file with EXPORT_SYMBOL or initcall or hardware exceptions
as its only entry points). The traditional built works "by luck" as
built-in.o files are large enough that they're going to get external
references. However this optimisation is unpredictable for the kernel
(due to above external references), ineffective at culling unused, and
costly because the .o files have to be searched for references.
Superior alternatives for link-time culling should be used instead.
Build characteristics for inclink vs thinarc, on a small powerpc64le
pseries VM with a modest .config:
inclink thinarc
sizes
vmlinux 15 618 680 15 625 028
sum of all built-in.o 56 091 808 1 054 334
sum excluding root built-in.o 151 430
find -name built-in.o | xargs rm ; time make vmlinux
real 22.772s 21.143s
user 13.280s 13.430s
sys 4.310s 2.750s
- Final kernel pulled in only about 6K more, which shows how
ineffective the object file culling is.
- Build performance looks improved due to less pagecache activity.
On IO constrained systems it could be a bigger win.
- Build size saving is significant.
Side note, the toochain understands archives, so there's some tricks,
$ ar t built-in.o # list all files you linked with
$ size built-in.o # and their sizes
$ objdump -d built-in.o # disassembly (unrelocated) with filenames
Implementation by sfr, minor tweaks by npiggin.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-08-24 20:29:19 +08:00
|
|
|
|
|
|
|
|
ifdef CONFIG_THIN_ARCHIVES
|
2017-06-09 13:24:14 +08:00
|
|
|
cmd_link_l_target = rm -f $@; $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(lib-y)
|
kbuild: allow architectures to use thin archives instead of ld -r
ld -r is an incremental link used to create built-in.o files in build
subdirectories. It produces relocatable object files containing all
its input files, and these are are then pulled together and relocated
in the final link. Aside from the bloat, this constrains the final
link relocations, which has bitten large powerpc builds with
unresolvable relocations in the final link.
Alan Modra has recommended the kernel use thin archives for linking.
This is an alternative and means that the linker has more information
available to it when it links the kernel.
This patch enables a config option architectures can select, which
causes all built-in.o files to be built as thin archives. built-in.o
files in subdirectories do not get symbol table or index attached,
which improves speed and size. The final link pass creates a
built-in.o archive in the root output directory which includes the
symbol table and index. The linker then uses takes this file to link.
The --whole-archive linker option is required, because the linker now
has visibility to every individual object file, and it will otherwise
just completely avoid including those without external references
(consider a file with EXPORT_SYMBOL or initcall or hardware exceptions
as its only entry points). The traditional built works "by luck" as
built-in.o files are large enough that they're going to get external
references. However this optimisation is unpredictable for the kernel
(due to above external references), ineffective at culling unused, and
costly because the .o files have to be searched for references.
Superior alternatives for link-time culling should be used instead.
Build characteristics for inclink vs thinarc, on a small powerpc64le
pseries VM with a modest .config:
inclink thinarc
sizes
vmlinux 15 618 680 15 625 028
sum of all built-in.o 56 091 808 1 054 334
sum excluding root built-in.o 151 430
find -name built-in.o | xargs rm ; time make vmlinux
real 22.772s 21.143s
user 13.280s 13.430s
sys 4.310s 2.750s
- Final kernel pulled in only about 6K more, which shows how
ineffective the object file culling is.
- Build performance looks improved due to less pagecache activity.
On IO constrained systems it could be a bigger win.
- Build size saving is significant.
Side note, the toochain understands archives, so there's some tricks,
$ ar t built-in.o # list all files you linked with
$ size built-in.o # and their sizes
$ objdump -d built-in.o # disassembly (unrelocated) with filenames
Implementation by sfr, minor tweaks by npiggin.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-08-24 20:29:19 +08:00
|
|
|
else
|
|
|
|
|
cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
|
|
|
|
|
endif
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
|
$(lib-target): $(lib-y) FORCE
|
|
|
|
|
$(call if_changed,link_l_target)
|
|
|
|
|
|
|
|
|
|
targets += $(lib-target)
|
2016-01-16 03:01:22 +08:00
|
|
|
|
|
|
|
|
dummy-object = $(obj)/.lib_exports.o
|
|
|
|
|
ksyms-lds = $(dot-target).lds
|
|
|
|
|
ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
|
|
|
|
|
ref_prefix = EXTERN(_
|
|
|
|
|
else
|
|
|
|
|
ref_prefix = EXTERN(
|
|
|
|
|
endif
|
|
|
|
|
|
|
|
|
|
quiet_cmd_export_list = EXPORTS $@
|
|
|
|
|
cmd_export_list = $(OBJDUMP) -h $< | \
|
2016-11-17 08:28:39 +08:00
|
|
|
sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/$(ref_prefix)\1)/p' >$(ksyms-lds);\
|
2016-01-16 03:01:22 +08:00
|
|
|
rm -f $(dummy-object);\
|
2016-11-24 00:41:40 +08:00
|
|
|
echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
|
2016-01-16 03:01:22 +08:00
|
|
|
$(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\
|
|
|
|
|
rm $(dummy-object) $(ksyms-lds)
|
|
|
|
|
|
|
|
|
|
$(obj)/lib-ksyms.o: $(lib-target) FORCE
|
|
|
|
|
$(call if_changed,export_list)
|
2016-10-20 22:13:33 +08:00
|
|
|
|
|
|
|
|
targets += $(obj)/lib-ksyms.o
|
|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
endif
|
|
|
|
|
|
|
|
|
|
#
|
|
|
|
|
# Rule to link composite objects
|
|
|
|
|
#
|
|
|
|
|
# Composite objects are specified in kbuild makefile as follows:
|
|
|
|
|
# <composite-object>-objs := <list of .o files>
|
|
|
|
|
# or
|
|
|
|
|
# <composite-object>-y := <list of .o files>
|
2015-10-27 21:02:24 +08:00
|
|
|
# or
|
|
|
|
|
# <composite-object>-m := <list of .o files>
|
|
|
|
|
# The -m syntax only works if <composite object> is a module
|
2005-04-17 06:20:36 +08:00
|
|
|
link_multi_deps = \
|
|
|
|
|
$(filter $(addprefix $(obj)/, \
|
|
|
|
|
$($(subst $(obj)/,,$(@:.o=-objs))) \
|
2015-10-27 21:02:24 +08:00
|
|
|
$($(subst $(obj)/,,$(@:.o=-y))) \
|
|
|
|
|
$($(subst $(obj)/,,$(@:.o=-m)))), $^)
|
2014-04-28 15:26:18 +08:00
|
|
|
|
2016-11-24 00:41:38 +08:00
|
|
|
cmd_link_multi-link = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
|
|
|
|
|
|
|
|
|
|
ifdef CONFIG_THIN_ARCHIVES
|
|
|
|
|
quiet_cmd_link_multi-y = AR $@
|
2017-06-09 13:24:14 +08:00
|
|
|
cmd_link_multi-y = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(link_multi_deps)
|
2016-11-24 00:41:38 +08:00
|
|
|
else
|
|
|
|
|
quiet_cmd_link_multi-y = LD $@
|
|
|
|
|
cmd_link_multi-y = $(cmd_link_multi-link)
|
|
|
|
|
endif
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
|
quiet_cmd_link_multi-m = LD [M] $@
|
2016-11-24 00:41:38 +08:00
|
|
|
cmd_link_multi-m = $(cmd_link_multi-link)
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2014-08-19 15:34:20 +08:00
|
|
|
$(multi-used-y): FORCE
|
2005-04-17 06:20:36 +08:00
|
|
|
$(call if_changed,link_multi-y)
|
2014-08-19 15:34:20 +08:00
|
|
|
$(call multi_depend, $(multi-used-y), .o, -objs -y)
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2014-08-19 15:34:20 +08:00
|
|
|
$(multi-used-m): FORCE
|
2005-04-17 06:20:36 +08:00
|
|
|
$(call if_changed,link_multi-m)
|
2016-01-22 06:07:24 +08:00
|
|
|
@{ echo $(@:.o=.ko); echo $(link_multi_deps); \
|
|
|
|
|
$(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
|
2015-10-27 21:02:24 +08:00
|
|
|
$(call multi_depend, $(multi-used-m), .o, -objs -y -m)
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
|
targets += $(multi-used-y) $(multi-used-m)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
# Descending
|
|
|
|
|
# ---------------------------------------------------------------------------
|
|
|
|
|
|
2006-03-06 06:14:10 +08:00
|
|
|
PHONY += $(subdir-ym)
|
2005-04-17 06:20:36 +08:00
|
|
|
$(subdir-ym):
|
|
|
|
|
$(Q)$(MAKE) $(build)=$@
|
|
|
|
|
|
|
|
|
|
# Add FORCE to the prequisites of a target to force it to be always rebuilt.
|
|
|
|
|
# ---------------------------------------------------------------------------
|
|
|
|
|
|
2006-03-06 06:14:10 +08:00
|
|
|
PHONY += FORCE
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
|
FORCE:
|
|
|
|
|
|
|
|
|
|
# Read all saved command lines and dependencies for the $(targets) we
|
|
|
|
|
# may be building above, using $(if_changed{,_dep}). As an
|
|
|
|
|
# optimization, we don't need to read them if the target does not
|
|
|
|
|
# exist, we will rebuild anyway in that case.
|
|
|
|
|
|
|
|
|
|
targets := $(wildcard $(sort $(targets)))
|
|
|
|
|
cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
|
|
|
|
|
|
|
|
|
|
ifneq ($(cmd_files),)
|
|
|
|
|
include $(cmd_files)
|
|
|
|
|
endif
|
2006-03-06 06:14:10 +08:00
|
|
|
|
|
|
|
|
# Declare the contents of the .PHONY variable as phony. We keep that
|
|
|
|
|
# information in a variable se we can use it in if_changed and friends.
|
|
|
|
|
|
|
|
|
|
.PHONY: $(PHONY)
|