This is a note to let you know that I've just added the patch titled

kbuild: modversions for EXPORT_SYMBOL() for asm

to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: kbuild-modversions-for-export_symbol-for-asm.patch and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 4efca4ed05cbdfd13ec3e8cb623fb77d6e4ab187 Mon Sep 17 00:00:00 2001

From: Nicholas Piggin npiggin@gmail.com Date: Tue, 1 Nov 2016 12:46:19 +1100 Subject: kbuild: modversions for EXPORT_SYMBOL() for asm

From: Nicholas Piggin npiggin@gmail.com

commit 4efca4ed05cbdfd13ec3e8cb623fb77d6e4ab187 upstream.

Allow architectures to create asm/asm-prototypes.h file that provides C prototypes for exported asm functions, which enables proper CRC versions to be generated for them.

Signed-off-by: Nicholas Piggin npiggin@gmail.com Signed-off-by: Michal Marek mmarek@suse.com [jkosina@suse.cz: folded cc6acc11cad1 fixup in as well ] Signed-off-by: Jiri Kosina jkosina@suse.cz Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- scripts/Makefile.build | 87 +++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 80 insertions(+), 7 deletions(-)

--- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -158,7 +158,8 @@ cmd_cc_i_c = $(CPP) $(c_flags) - $(obj)/%.i: $(src)/%.c FORCE $(call if_changed_dep,cc_i_c)

-cmd_gensymtypes = \ +# These mirror gensymtypes_S and co below, keep them in synch. +cmd_gensymtypes_c = \ $(CPP) -D__GENKSYMS__ $(c_flags) $< | \ $(GENKSYMS) $(if $(1), -T $(2)) \ $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \ @@ -168,7 +169,7 @@ cmd_gensymtypes = quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@ cmd_cc_symtypes_c = \ set -e; \ - $(call cmd_gensymtypes,true,$@) >/dev/null; \ + $(call cmd_gensymtypes_c,true,$@) >/dev/null; \ test -s $@ || rm -f $@

$(obj)/%.symtypes : $(src)/%.c FORCE @@ -197,9 +198,10 @@ else # the actual value of the checksum generated by genksyms

cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $< -cmd_modversions = \ + +cmd_modversions_c = \ if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ - $(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ + $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ > $(@D)/.tmp_$(@F:.o=.ver); \ \ $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \ @@ -244,7 +246,7 @@ endif define rule_cc_o_c $(call echo-cmd,checksrc) $(cmd_checksrc) \ $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \ - $(cmd_modversions) \ + $(cmd_modversions_c) \ $(call echo-cmd,record_mcount) \ $(cmd_record_mcount) \ scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \ @@ -253,6 +255,15 @@ define rule_cc_o_c mv -f $(dot-target).tmp $(dot-target).cmd endef

+define rule_as_o_S + $(call echo-cmd,as_o_S) $(cmd_as_o_S); \ + scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,as_o_S)' > \ + $(dot-target).tmp; \ + $(cmd_modversions_S) \ + rm -f $(depfile); \ + mv -f $(dot-target).tmp $(dot-target).cmd +endef + # Built-in and composite module parts $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE $(call cmd,force_checksrc) @@ -281,6 +292,38 @@ modkern_aflags := $(KBUILD_AFLAGS_KERNEL $(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE) $(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)

+# .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) $< | \ + grep "<___EXPORT_SYMBOL>" | \ + sed 's/.*___EXPORT_SYMBOL[[:space:]]*([a-zA-Z0-9_]*)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \ + $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \ + $(GENKSYMS) $(if $(1), -T $(2)) \ + $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \ + $(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) + quiet_cmd_as_s_S = CPP $(quiet_modtag) $@ cmd_as_s_S = $(CPP) $(a_flags) -o $@ $<

@@ -288,10 +331,40 @@ $(obj)/%.s: $(src)/%.S FORCE $(call if_changed_dep,as_s_S)

quiet_cmd_as_o_S = AS $(quiet_modtag) $@ -cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< + +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

$(obj)/%.o: $(src)/%.S FORCE - $(call if_changed_dep,as_o_S) + $(call if_changed_rule,as_o_S)

targets += $(real-objs-y) $(real-objs-m) $(lib-y) targets += $(extra-y) $(MAKECMDGOALS) $(always)

Patches currently in stable-queue which might be from npiggin@gmail.com are

queue-4.4/kbuild-modversions-for-export_symbol-for-asm.patch queue-4.4/x86-kbuild-enable-modversions-for-symbols-exported-from-asm.patch