* [PATCH 2/5] kbuild: detect objtool changes correctly without .SECONDEXPANSION
2021-08-28 9:50 [PATCH 1/5] modpost: get the *.mod file path more simply Masahiro Yamada
@ 2021-08-28 9:51 ` Masahiro Yamada
2021-08-31 1:43 ` Masahiro Yamada
2021-08-28 9:51 ` [PATCH 3/5] kbuild: clean up objtool_args slightly Masahiro Yamada
` (3 subsequent siblings)
4 siblings, 1 reply; 8+ messages in thread
From: Masahiro Yamada @ 2021-08-28 9:51 UTC (permalink / raw)
To: linux-kbuild
Cc: Masahiro Yamada, Michal Marek, Nick Desaulniers, linux-kernel
This reverts commit 8852c5524029 ("kbuild: Fix objtool dependency for
'OBJECT_FILES_NON_STANDARD_<obj> := n'"), and fixes the dependency in
a cleaner, more precise way.
Using .SECONDEXPANSION is expensive since Makefile.build is parsed
twice every time, and the escaping dollars makes the code unreadable.
Adding include/config/* as dependency is not maintainable either because
objtool_args is dependent on more CONFIG options.
A better fix is to include the objtool command in *.cmd files so any
command change is naturally detected by if_change.
Also, include the md5sum of objtool into *.cmd files so any change in
the objtool executable will result in rebuilding all objects that depend
on objtool.
This allows us to drop $(objtool_deps) entirely.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
Makefile | 3 ++-
scripts/Makefile.build | 26 +++++++++-----------------
scripts/link-vmlinux.sh | 3 ++-
3 files changed, 13 insertions(+), 19 deletions(-)
diff --git a/Makefile b/Makefile
index 829bd339ffdc..3ef3685b7e4a 100644
--- a/Makefile
+++ b/Makefile
@@ -1858,7 +1858,8 @@ descend: $(build-dirs)
$(build-dirs): prepare
$(Q)$(MAKE) $(build)=$@ \
single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
- need-builtin=1 need-modorder=1
+ need-builtin=1 need-modorder=1 \
+ $(if $(CONFIG_STACK_VALIDATION),objtool-md5sum=$(firstword $(shell md5sum tools/objtool/objtool)))
clean-dirs := $(addprefix _clean_, $(clean-dirs))
PHONY += $(clean-dirs) clean
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 3efc984d4c69..8aa6eaa4bf21 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -155,7 +155,7 @@ $(obj)/%.ll: $(src)/%.c FORCE
# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
- cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
+ cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< $(cmd_objtool)
ifdef CONFIG_MODVERSIONS
# When module versioning is enabled the following steps are executed:
@@ -226,26 +226,21 @@ endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
ifdef CONFIG_STACK_VALIDATION
ifndef CONFIG_LTO_CLANG
-__objtool_obj := $(objtree)/tools/objtool/objtool
+objtool := $(objtree)/tools/objtool/objtool
# '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
+#
+# Record the md5sum of the objtool executable so any change in it results in
+# rebuilding objects.
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))
+ ; : $(objtool-md5sum) ; $(objtool) $(objtool_args) $@)
endif # CONFIG_LTO_CLANG
endif # CONFIG_STACK_VALIDATION
-# Rebuild all objects when objtool changes, or is enabled/disabled.
-objtool_dep = $(objtool_obj) \
- $(wildcard include/config/ORC_UNWINDER \
- include/config/STACK_VALIDATION)
-
ifdef CONFIG_TRIM_UNUSED_KSYMS
cmd_gen_ksymdeps = \
$(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
@@ -259,7 +254,6 @@ define rule_cc_o_c
$(call cmd,gen_ksymdeps)
$(call cmd,checksrc)
$(call cmd,checkdoc)
- $(call cmd,objtool)
$(call cmd,modversions_c)
$(call cmd,record_mcount)
endef
@@ -267,13 +261,11 @@ endef
define rule_as_o_S
$(call cmd_and_fixdep,as_o_S)
$(call cmd,gen_ksymdeps)
- $(call cmd,objtool)
$(call cmd,modversions_S)
endef
# Built-in and composite module parts
-.SECONDEXPANSION:
-$(obj)/%.o: $(src)/%.c $(recordmcount_source) $$(objtool_dep) FORCE
+$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
$(call if_changed_rule,cc_o_c)
$(call cmd,force_checksrc)
@@ -356,7 +348,7 @@ $(obj)/%.s: $(src)/%.S FORCE
$(call if_changed_dep,cpp_s_S)
quiet_cmd_as_o_S = AS $(quiet_modtag) $@
- cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
+ cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
ifdef CONFIG_ASM_MODVERSIONS
@@ -375,7 +367,7 @@ cmd_modversions_S = \
fi
endif
-$(obj)/%.o: $(src)/%.S $$(objtool_dep) FORCE
+$(obj)/%.o: $(src)/%.S FORCE
$(call if_changed_rule,as_o_S)
targets += $(filter-out $(subdir-builtin), $(real-obj-y))
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index d74cee5c4326..58b3a94c934b 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -335,7 +335,8 @@ else
fi;
# final build of init/
-${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init need-builtin=1
+${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init need-builtin=1 \
+ ${CONFIG_STACK_VALIDATION:+objtool-md5sum=$(md5sum tools/objtool/objtool | cut -d ' ' -f1)}
#link vmlinux.o
modpost_link vmlinux.o
--
2.30.2
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH 2/5] kbuild: detect objtool changes correctly without .SECONDEXPANSION
2021-08-28 9:51 ` [PATCH 2/5] kbuild: detect objtool changes correctly without .SECONDEXPANSION Masahiro Yamada
@ 2021-08-31 1:43 ` Masahiro Yamada
0 siblings, 0 replies; 8+ messages in thread
From: Masahiro Yamada @ 2021-08-31 1:43 UTC (permalink / raw)
To: Linux Kbuild mailing list
Cc: Michal Marek, Nick Desaulniers, Linux Kernel Mailing List
On Sat, Aug 28, 2021 at 6:51 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> This reverts commit 8852c5524029 ("kbuild: Fix objtool dependency for
> 'OBJECT_FILES_NON_STANDARD_<obj> := n'"), and fixes the dependency in
> a cleaner, more precise way.
>
> Using .SECONDEXPANSION is expensive since Makefile.build is parsed
> twice every time, and the escaping dollars makes the code unreadable.
>
> Adding include/config/* as dependency is not maintainable either because
> objtool_args is dependent on more CONFIG options.
>
> A better fix is to include the objtool command in *.cmd files so any
> command change is naturally detected by if_change.
>
> Also, include the md5sum of objtool into *.cmd files so any change in
> the objtool executable will result in rebuilding all objects that depend
> on objtool.
After more consideration, I decided not to do this.
(I retract 2/5, 4/5, 5/5 from this series).
I came up with a cleaner patch set.
I will send it later.
> This allows us to drop $(objtool_deps) entirely.
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> ---
>
> Makefile | 3 ++-
> scripts/Makefile.build | 26 +++++++++-----------------
> scripts/link-vmlinux.sh | 3 ++-
> 3 files changed, 13 insertions(+), 19 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index 829bd339ffdc..3ef3685b7e4a 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1858,7 +1858,8 @@ descend: $(build-dirs)
> $(build-dirs): prepare
> $(Q)$(MAKE) $(build)=$@ \
> single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
> - need-builtin=1 need-modorder=1
> + need-builtin=1 need-modorder=1 \
> + $(if $(CONFIG_STACK_VALIDATION),objtool-md5sum=$(firstword $(shell md5sum tools/objtool/objtool)))
>
> clean-dirs := $(addprefix _clean_, $(clean-dirs))
> PHONY += $(clean-dirs) clean
> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> index 3efc984d4c69..8aa6eaa4bf21 100644
> --- a/scripts/Makefile.build
> +++ b/scripts/Makefile.build
> @@ -155,7 +155,7 @@ $(obj)/%.ll: $(src)/%.c FORCE
> # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
>
> quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
> - cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
> + cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< $(cmd_objtool)
>
> ifdef CONFIG_MODVERSIONS
> # When module versioning is enabled the following steps are executed:
> @@ -226,26 +226,21 @@ endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
> ifdef CONFIG_STACK_VALIDATION
> ifndef CONFIG_LTO_CLANG
>
> -__objtool_obj := $(objtree)/tools/objtool/objtool
> +objtool := $(objtree)/tools/objtool/objtool
>
> # '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
> +#
> +# Record the md5sum of the objtool executable so any change in it results in
> +# rebuilding objects.
> 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))
> + ; : $(objtool-md5sum) ; $(objtool) $(objtool_args) $@)
>
> endif # CONFIG_LTO_CLANG
> endif # CONFIG_STACK_VALIDATION
>
> -# Rebuild all objects when objtool changes, or is enabled/disabled.
> -objtool_dep = $(objtool_obj) \
> - $(wildcard include/config/ORC_UNWINDER \
> - include/config/STACK_VALIDATION)
> -
> ifdef CONFIG_TRIM_UNUSED_KSYMS
> cmd_gen_ksymdeps = \
> $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
> @@ -259,7 +254,6 @@ define rule_cc_o_c
> $(call cmd,gen_ksymdeps)
> $(call cmd,checksrc)
> $(call cmd,checkdoc)
> - $(call cmd,objtool)
> $(call cmd,modversions_c)
> $(call cmd,record_mcount)
> endef
> @@ -267,13 +261,11 @@ endef
> define rule_as_o_S
> $(call cmd_and_fixdep,as_o_S)
> $(call cmd,gen_ksymdeps)
> - $(call cmd,objtool)
> $(call cmd,modversions_S)
> endef
>
> # Built-in and composite module parts
> -.SECONDEXPANSION:
> -$(obj)/%.o: $(src)/%.c $(recordmcount_source) $$(objtool_dep) FORCE
> +$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
> $(call if_changed_rule,cc_o_c)
> $(call cmd,force_checksrc)
>
> @@ -356,7 +348,7 @@ $(obj)/%.s: $(src)/%.S FORCE
> $(call if_changed_dep,cpp_s_S)
>
> quiet_cmd_as_o_S = AS $(quiet_modtag) $@
> - cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
> + cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
>
> ifdef CONFIG_ASM_MODVERSIONS
>
> @@ -375,7 +367,7 @@ cmd_modversions_S = \
> fi
> endif
>
> -$(obj)/%.o: $(src)/%.S $$(objtool_dep) FORCE
> +$(obj)/%.o: $(src)/%.S FORCE
> $(call if_changed_rule,as_o_S)
>
> targets += $(filter-out $(subdir-builtin), $(real-obj-y))
> diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
> index d74cee5c4326..58b3a94c934b 100755
> --- a/scripts/link-vmlinux.sh
> +++ b/scripts/link-vmlinux.sh
> @@ -335,7 +335,8 @@ else
> fi;
>
> # final build of init/
> -${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init need-builtin=1
> +${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init need-builtin=1 \
> + ${CONFIG_STACK_VALIDATION:+objtool-md5sum=$(md5sum tools/objtool/objtool | cut -d ' ' -f1)}
>
> #link vmlinux.o
> modpost_link vmlinux.o
> --
> 2.30.2
>
--
Best Regards
Masahiro Yamada
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH 3/5] kbuild: clean up objtool_args slightly
2021-08-28 9:50 [PATCH 1/5] modpost: get the *.mod file path more simply Masahiro Yamada
2021-08-28 9:51 ` [PATCH 2/5] kbuild: detect objtool changes correctly without .SECONDEXPANSION Masahiro Yamada
@ 2021-08-28 9:51 ` Masahiro Yamada
2021-08-31 1:41 ` Masahiro Yamada
2021-08-28 9:51 ` [PATCH 4/5] kbuild: merge objtool_args into objtool in scripts/Makefile.build Masahiro Yamada
` (2 subsequent siblings)
4 siblings, 1 reply; 8+ messages in thread
From: Masahiro Yamada @ 2021-08-28 9:51 UTC (permalink / raw)
To: linux-kbuild
Cc: Masahiro Yamada, Michal Marek, Nick Desaulniers, linux-kernel
The code:
$(if $(or $(CONFIG_GCOV_KERNEL),$(CONFIG_LTO_CLANG)), ...)
... can be simpled to:
$(if $(CONFIG_GCOV_KERNEL)$(CONFIG_LTO_CLANG), ...)
Also, remove meaningless commas at the end of $(if ...).
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
scripts/Makefile.lib | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index af1c920a585c..cd011f3f6f78 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -236,13 +236,12 @@ endif
# then here to avoid duplication.
objtool_args = \
$(if $(CONFIG_UNWINDER_ORC),orc generate,check) \
- $(if $(part-of-module), --module,) \
+ $(if $(part-of-module), --module) \
$(if $(CONFIG_FRAME_POINTER),, --no-fp) \
- $(if $(or $(CONFIG_GCOV_KERNEL),$(CONFIG_LTO_CLANG)), \
- --no-unreachable,) \
- $(if $(CONFIG_RETPOLINE), --retpoline,) \
- $(if $(CONFIG_X86_SMAP), --uaccess,) \
- $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount,)
+ $(if $(CONFIG_GCOV_KERNEL)$(CONFIG_LTO_CLANG), --no-unreachable)\
+ $(if $(CONFIG_RETPOLINE), --retpoline) \
+ $(if $(CONFIG_X86_SMAP), --uaccess) \
+ $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)
# Useful for describing the dependency of composite objects
# Usage:
--
2.30.2
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH 3/5] kbuild: clean up objtool_args slightly
2021-08-28 9:51 ` [PATCH 3/5] kbuild: clean up objtool_args slightly Masahiro Yamada
@ 2021-08-31 1:41 ` Masahiro Yamada
0 siblings, 0 replies; 8+ messages in thread
From: Masahiro Yamada @ 2021-08-31 1:41 UTC (permalink / raw)
To: Linux Kbuild mailing list
Cc: Michal Marek, Nick Desaulniers, Linux Kernel Mailing List
On Sat, Aug 28, 2021 at 6:51 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> The code:
>
> $(if $(or $(CONFIG_GCOV_KERNEL),$(CONFIG_LTO_CLANG)), ...)
>
> ... can be simpled to:
>
> $(if $(CONFIG_GCOV_KERNEL)$(CONFIG_LTO_CLANG), ...)
>
> Also, remove meaningless commas at the end of $(if ...).
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> ---
Applied this to linux-kbuild.
(only 1/5 and 3/5)
> scripts/Makefile.lib | 11 +++++------
> 1 file changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index af1c920a585c..cd011f3f6f78 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -236,13 +236,12 @@ endif
> # then here to avoid duplication.
> objtool_args = \
> $(if $(CONFIG_UNWINDER_ORC),orc generate,check) \
> - $(if $(part-of-module), --module,) \
> + $(if $(part-of-module), --module) \
> $(if $(CONFIG_FRAME_POINTER),, --no-fp) \
> - $(if $(or $(CONFIG_GCOV_KERNEL),$(CONFIG_LTO_CLANG)), \
> - --no-unreachable,) \
> - $(if $(CONFIG_RETPOLINE), --retpoline,) \
> - $(if $(CONFIG_X86_SMAP), --uaccess,) \
> - $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount,)
> + $(if $(CONFIG_GCOV_KERNEL)$(CONFIG_LTO_CLANG), --no-unreachable)\
> + $(if $(CONFIG_RETPOLINE), --retpoline) \
> + $(if $(CONFIG_X86_SMAP), --uaccess) \
> + $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)
>
> # Useful for describing the dependency of composite objects
> # Usage:
> --
> 2.30.2
>
--
Best Regards
Masahiro Yamada
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH 4/5] kbuild: merge objtool_args into objtool in scripts/Makefile.build
2021-08-28 9:50 [PATCH 1/5] modpost: get the *.mod file path more simply Masahiro Yamada
2021-08-28 9:51 ` [PATCH 2/5] kbuild: detect objtool changes correctly without .SECONDEXPANSION Masahiro Yamada
2021-08-28 9:51 ` [PATCH 3/5] kbuild: clean up objtool_args slightly Masahiro Yamada
@ 2021-08-28 9:51 ` Masahiro Yamada
2021-08-28 9:51 ` [PATCH 5/5] kbuild: rebuild *.lto.o when objtool is changed Masahiro Yamada
2021-08-31 1:41 ` [PATCH 1/5] modpost: get the *.mod file path more simply Masahiro Yamada
4 siblings, 0 replies; 8+ messages in thread
From: Masahiro Yamada @ 2021-08-28 9:51 UTC (permalink / raw)
To: linux-kbuild
Cc: Masahiro Yamada, Michal Marek, Nick Desaulniers, linux-kernel
Commit b1a1a1a09b46 ("kbuild: lto: postpone objtool") moved objtool_args
to Makefile.lib, so the arguments can be used in Makefile.modfinal as
well as Makefile.build.
With commit 2b1d7fc05467 ("kbuild: Fix TRIM_UNUSED_KSYMS with
LTO_CLANG"), module LTO linking came back to scripts/Makefile.build
again.
So, there is no more reason to keep objtool_args in a separate file.
Move it to scripts/Makefile.build and merge into the 'objtool' variable.
You might wonder why cmd_cc_lto_link_modules adds --module again. Add
a small comment to explain it.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
scripts/Makefile.build | 19 ++++++++++++++-----
scripts/Makefile.lib | 11 -----------
2 files changed, 14 insertions(+), 16 deletions(-)
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 8aa6eaa4bf21..cc0c494a48d3 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -224,9 +224,17 @@ cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)),
endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
ifdef CONFIG_STACK_VALIDATION
-ifndef CONFIG_LTO_CLANG
-objtool := $(objtree)/tools/objtool/objtool
+objtool = $(objtree)/tools/objtool/objtool \
+ $(if $(CONFIG_UNWINDER_ORC),orc generate,check) \
+ $(if $(part-of-module), --module) \
+ $(if $(CONFIG_FRAME_POINTER),, --no-fp) \
+ $(if $(CONFIG_GCOV_KERNEL)$(CONFIG_LTO_CLANG), --no-unreachable)\
+ $(if $(CONFIG_RETPOLINE), --retpoline) \
+ $(if $(CONFIG_X86_SMAP), --uaccess) \
+ $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)
+
+ifndef CONFIG_LTO_CLANG
# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
@@ -236,7 +244,7 @@ objtool := $(objtree)/tools/objtool/objtool
# rebuilding objects.
cmd_objtool = $(if $(patsubst y%,, \
$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
- ; : $(objtool-md5sum) ; $(objtool) $(objtool_args) $@)
+ ; : $(objtool-md5sum) ; $(objtool) $@)
endif # CONFIG_LTO_CLANG
endif # CONFIG_STACK_VALIDATION
@@ -282,8 +290,9 @@ cmd_cc_lto_link_modules = \
ifdef CONFIG_STACK_VALIDATION
# objtool was skipped for LLVM bitcode, run it now that we have compiled
# modules into native code
-cmd_cc_lto_link_modules += ; \
- $(objtree)/tools/objtool/objtool $(objtool_args) --module $@
+#
+# Repeat --module because $(part-of-module) does not work here.
+cmd_cc_lto_link_modules += ; $(objtool) --module $@
endif
$(obj)/%.lto.o: $(obj)/%.o FORCE
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index cd011f3f6f78..34c4c11c4bc1 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -232,17 +232,6 @@ ifeq ($(CONFIG_LTO_CLANG),y)
mod-prelink-ext := .lto
endif
-# Objtool arguments are also needed for modfinal with LTO, so we define
-# then here to avoid duplication.
-objtool_args = \
- $(if $(CONFIG_UNWINDER_ORC),orc generate,check) \
- $(if $(part-of-module), --module) \
- $(if $(CONFIG_FRAME_POINTER),, --no-fp) \
- $(if $(CONFIG_GCOV_KERNEL)$(CONFIG_LTO_CLANG), --no-unreachable)\
- $(if $(CONFIG_RETPOLINE), --retpoline) \
- $(if $(CONFIG_X86_SMAP), --uaccess) \
- $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)
-
# Useful for describing the dependency of composite objects
# Usage:
# $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
--
2.30.2
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 5/5] kbuild: rebuild *.lto.o when objtool is changed
2021-08-28 9:50 [PATCH 1/5] modpost: get the *.mod file path more simply Masahiro Yamada
` (2 preceding siblings ...)
2021-08-28 9:51 ` [PATCH 4/5] kbuild: merge objtool_args into objtool in scripts/Makefile.build Masahiro Yamada
@ 2021-08-28 9:51 ` Masahiro Yamada
2021-08-31 1:41 ` [PATCH 1/5] modpost: get the *.mod file path more simply Masahiro Yamada
4 siblings, 0 replies; 8+ messages in thread
From: Masahiro Yamada @ 2021-08-28 9:51 UTC (permalink / raw)
To: linux-kbuild
Cc: Masahiro Yamada, Michal Marek, Nick Desaulniers, linux-kernel
When objtool is changed, all objects are rebuilt, but this check
is missing in the %.lto.o rule.
Move the objtool-md5sum into the objtool variable so the updated
objtool is detected when CONFIG_LTO_CLANG=y as well.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
scripts/Makefile.build | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index cc0c494a48d3..790b72208668 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -225,7 +225,10 @@ endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
ifdef CONFIG_STACK_VALIDATION
-objtool = $(objtree)/tools/objtool/objtool \
+# Record the md5sum of the objtool executable so any change in it results in
+# rebuilding objects.
+objtool = : $(objtool-md5sum) ; \
+ $(objtree)/tools/objtool/objtool \
$(if $(CONFIG_UNWINDER_ORC),orc generate,check) \
$(if $(part-of-module), --module) \
$(if $(CONFIG_FRAME_POINTER),, --no-fp) \
@@ -239,12 +242,9 @@ ifndef CONFIG_LTO_CLANG
# '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
-#
-# Record the md5sum of the objtool executable so any change in it results in
-# rebuilding objects.
cmd_objtool = $(if $(patsubst y%,, \
$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
- ; : $(objtool-md5sum) ; $(objtool) $@)
+ ; $(objtool) $@)
endif # CONFIG_LTO_CLANG
endif # CONFIG_STACK_VALIDATION
--
2.30.2
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH 1/5] modpost: get the *.mod file path more simply
2021-08-28 9:50 [PATCH 1/5] modpost: get the *.mod file path more simply Masahiro Yamada
` (3 preceding siblings ...)
2021-08-28 9:51 ` [PATCH 5/5] kbuild: rebuild *.lto.o when objtool is changed Masahiro Yamada
@ 2021-08-31 1:41 ` Masahiro Yamada
4 siblings, 0 replies; 8+ messages in thread
From: Masahiro Yamada @ 2021-08-31 1:41 UTC (permalink / raw)
To: Linux Kbuild mailing list
Cc: Michal Marek, Nick Desaulniers, Linux Kernel Mailing List
On Sat, Aug 28, 2021 at 6:51 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> get_src_version() strips 'o' or 'lto.o' from the end of the object file
> path (so, postfixlen is 1 or 5), then adds 'mod'.
>
> If you look at the code closely, mod->name already holds the base path
> with the extension stripped.
>
> Most of the code changes made by commit 7ac204b545f2 ("modpost: lto:
> strip .lto from module names") was actually unneeded.
>
> sumversion.c does not need strends(), so it can get back local in
> modpost.c again.
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> ---
Applied this to linux-kbuild.
(only 1/5 and 3/5)
> scripts/mod/modpost.c | 11 ++++++++++-
> scripts/mod/modpost.h | 9 ---------
> scripts/mod/sumversion.c | 7 +------
> 3 files changed, 11 insertions(+), 16 deletions(-)
>
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index 270a7df898e2..a26139aa57fd 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -17,6 +17,7 @@
> #include <ctype.h>
> #include <string.h>
> #include <limits.h>
> +#include <stdbool.h>
> #include <errno.h>
> #include "modpost.h"
> #include "../../include/linux/license.h"
> @@ -89,6 +90,14 @@ modpost_log(enum loglevel loglevel, const char *fmt, ...)
> error_occurred = true;
> }
>
> +static inline bool strends(const char *str, const char *postfix)
> +{
> + if (strlen(str) < strlen(postfix))
> + return false;
> +
> + return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
> +}
> +
> void *do_nofail(void *ptr, const char *expr)
> {
> if (!ptr)
> @@ -2060,7 +2069,7 @@ static void read_symbols(const char *modname)
> if (!mod->is_vmlinux) {
> version = get_modinfo(&info, "version");
> if (version || all_versions)
> - get_src_version(modname, mod->srcversion,
> + get_src_version(mod->name, mod->srcversion,
> sizeof(mod->srcversion) - 1);
> }
>
> diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
> index c1a895c0d682..0c47ff95c0e2 100644
> --- a/scripts/mod/modpost.h
> +++ b/scripts/mod/modpost.h
> @@ -2,7 +2,6 @@
> #include <stdio.h>
> #include <stdlib.h>
> #include <stdarg.h>
> -#include <stdbool.h>
> #include <string.h>
> #include <sys/types.h>
> #include <sys/stat.h>
> @@ -178,14 +177,6 @@ static inline unsigned int get_secindex(const struct elf_info *info,
> return info->symtab_shndx_start[sym - info->symtab_start];
> }
>
> -static inline bool strends(const char *str, const char *postfix)
> -{
> - if (strlen(str) < strlen(postfix))
> - return false;
> -
> - return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
> -}
> -
> /* file2alias.c */
> extern unsigned int cross_build;
> void handle_moddevtable(struct module *mod, struct elf_info *info,
> diff --git a/scripts/mod/sumversion.c b/scripts/mod/sumversion.c
> index 760e6baa7eda..905c0ec291e1 100644
> --- a/scripts/mod/sumversion.c
> +++ b/scripts/mod/sumversion.c
> @@ -391,14 +391,9 @@ void get_src_version(const char *modname, char sum[], unsigned sumlen)
> struct md4_ctx md;
> char *fname;
> char filelist[PATH_MAX + 1];
> - int postfix_len = 1;
> -
> - if (strends(modname, ".lto.o"))
> - postfix_len = 5;
>
> /* objects for a module are listed in the first line of *.mod file. */
> - snprintf(filelist, sizeof(filelist), "%.*smod",
> - (int)strlen(modname) - postfix_len, modname);
> + snprintf(filelist, sizeof(filelist), "%s.mod", modname);
>
> buf = read_text_file(filelist);
>
> --
> 2.30.2
>
--
Best Regards
Masahiro Yamada
^ permalink raw reply [flat|nested] 8+ messages in thread