[PATCH 1/3] kbuild: improve EXPORT_SYMBOL() parsing from asm code
From: Nicolas Pitre <hidden>
Date: 2016-11-30 08:50:49
Also in:
linux-arm-kernel, linux-kbuild, lkml
Subsystem:
generic include/asm header files, kernel build + files below scripts/ (unless maintained elsewhere), the rest · Maintainers:
Arnd Bergmann, Nathan Chancellor, Nicolas Schier, Linus Torvalds
First, make the asm-prototypes.h presence optional. The next patch will make it unneeded for modversion support. Use the -D__GENKSYMS__ like we do for .c files but to expand the EXPORT_SYMBOL macro using the preprocessor instead of a sed script. The preprocessor output parsing is then limited to a simpler filtering and made more robust against multiple assembly statements on a single line. Signed-off-by: Nicolas Pitre <redacted> --- include/asm-generic/export.h | 9 +++++++++ scripts/Makefile.build | 20 ++++++-------------- 2 files changed, 15 insertions(+), 14 deletions(-)
diff --git a/include/asm-generic/export.h b/include/asm-generic/export.h
index 63554e9f6e..39a19dc366 100644
--- a/include/asm-generic/export.h
+++ b/include/asm-generic/export.h@@ -28,6 +28,8 @@ #define KSYM(name) name #endif +#if defined(__KERNEL__) && !defined(__GENKSYMS__) + /* * note on .section use: @progbits vs %progbits nastiness doesn't matter, * since we immediately emit into those sections anyway.
@@ -82,6 +84,13 @@ KSYM(__kcrctab_\name): #define __EXPORT_SYMBOL(sym, val, sec) ___EXPORT_SYMBOL sym, val, sec #endif +#else /* __GENKSYMS__ */ + +/* create a preprocessor output suitable for cmd_gensymtypes_S */ +#define __EXPORT_SYMBOL(sym, val, sec) EXPORT_SYMBOL(sym) + +#endif /* __GENKSYMS__ */ + #define EXPORT_SYMBOL(name) \ __EXPORT_SYMBOL(name, KSYM_FUNC(KSYM(name)),) #define EXPORT_SYMBOL_GPL(name) \
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 7675d11ee6..ebf6e08ae4 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build@@ -325,15 +325,15 @@ $(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE) # 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. +# to make the genksyms input. See also include/asm-generic/export.h. # # 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) $< | \ - grep "\<___EXPORT_SYMBOL\>" | \ - sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \ + ( echo "\#include <linux/kernel.h>" ; \ + if [ -e $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h ]; \ + then echo "\#include <asm/asm-prototypes.h>"; fi; \ + $(CPP) -D__GENKSYMS__ $(a_flags) $< | tr ";" "\n" | \ + sed -n -e '/EXPORT_SYMBOL(/s/$$/;/p' ) | \ $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \ $(GENKSYMS) $(if $(1), -T $(2)) \ $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \
@@ -363,13 +363,6 @@ 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.
@@ -387,7 +380,6 @@ cmd_modversions_S = \ mv -f $(@D)/.tmp_$(@F) $@; \ fi; endif -endif $(obj)/%.o: $(src)/%.S $(objtool_obj) FORCE $(call if_changed_rule,as_o_S)
--
2.7.4