On Sat, 22 Oct 2016 17:36:34 +0200
Michal Marek <mmarek@xxxxxxxx> wrote:
> Dne 20.10.2016 v 10:03 Arnd Bergmann napsal(a):
> > On Thursday, October 20, 2016 2:58:27 PM CEST Nicholas Piggin wrote:
> >>
> >> Yeah, I had the same idea as you and Michal too. It's conceptually nicer,
> >> but in practice it turned into a mess. If some architectures wanted to start
> >> protecting their .h files and including them into .S for the prototypes, we
> >> could start parsing those too. Should we do the quick and dirty way for 4.9?
> >
> > Let's stay with your approach for now.
>
> Agreed.
My patch 2/2 needs the following incremental patch applied. It is
to preprocess the .S file properly as asm the same way the kernel
build does, and then building the dummy C from there.
Without this, we don't necessarily get proper symbol expansion or
get conditional compilation, etc. With it, genksyms should see what
the assembler sees.
---
scripts/Makefile.build | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 2e512a2..6beeb9e 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -321,12 +321,19 @@ $(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
# 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>" ; \
- grep EXPORT_SYMBOL $< | sed 's/$$/;/' ) | \
+ $(CPP) $(a_flags) $< | \
+ grep ^___EXPORT_SYMBOL | \
+ sed 's/___EXPORT_SYMBOL \([a-zA-Z0-9_]*\),.*/EXPORT_SYMBOL(\1);/' ) | \
$(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \
$(GENKSYMS) $(if $(1), -T $(2)) \
$(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \
--
2.9.3
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