| Message ID | 1507800145-29563-1-git-send-email-yamada.masahiro@socionext.com |
|---|---|
| State | Accepted |
| Commit | 433dc2ebe7d17dd21cba7ad5c362d37323592236 |
| Headers | show |
| Series | kbuild: do not call cc-option before KBUILD_CFLAGS initialization | expand |
Hi, On Thu, Oct 12, 2017 at 2:22 AM, Masahiro Yamada <yamada.masahiro@socionext.com> wrote: > Some $(call cc-option,...) are invoked very early, even before > KBUILD_CFLAGS, etc. are initialized. > > The returned string from $(call cc-option,...) depends on > KBUILD_CPPFLAGS, KBUILD_CFLAGS, and GCC_PLUGINS_CFLAGS. > > Since they are exported, they are not empty when the top Makefile > is recursively invoked. > > The recursion occurs in several places. For example, the top > Makefile invokes itself for silentoldconfig. "make tinyconfig", > "make rpm-pkg" are the cases, too. > > In those cases, the second call of cc-option from the same line > runs a different shell command due to non-pristine KBUILD_CFLAGS. > > To get the same result all the time, KBUILD_* and GCC_PLUGINS_CFLAGS > must be initialized before any call of cc-option. This avoids > garbage data in the .cache.mk file. > > Move all calls of cc-option below the config targets because target > compiler flags are unnecessary for Kconfig. > > Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> > --- > > Makefile | 21 +++++++++++---------- > 1 file changed, 11 insertions(+), 10 deletions(-) I can't pretend that I know of all the subtleties involved in the twisty turny passages of the kernel Makefiles, but as far as I can tell this looks good. Thanks! Reviewed-by: Douglas Anderson <dianders@chromium.org>
2017-10-12 18:22 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>: > Some $(call cc-option,...) are invoked very early, even before > KBUILD_CFLAGS, etc. are initialized. > > The returned string from $(call cc-option,...) depends on > KBUILD_CPPFLAGS, KBUILD_CFLAGS, and GCC_PLUGINS_CFLAGS. > > Since they are exported, they are not empty when the top Makefile > is recursively invoked. > > The recursion occurs in several places. For example, the top > Makefile invokes itself for silentoldconfig. "make tinyconfig", > "make rpm-pkg" are the cases, too. > > In those cases, the second call of cc-option from the same line > runs a different shell command due to non-pristine KBUILD_CFLAGS. > > To get the same result all the time, KBUILD_* and GCC_PLUGINS_CFLAGS > must be initialized before any call of cc-option. This avoids > garbage data in the .cache.mk file. > > Move all calls of cc-option below the config targets because target > compiler flags are unnecessary for Kconfig. > > Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> > --- Applied to linux-kbuild/kbuild. -- Best Regards Masahiro Yamada
diff --git a/Makefile b/Makefile index e5c20ee..2c4a238 100644 --- a/Makefile +++ b/Makefile @@ -392,9 +392,6 @@ LDFLAGS_MODULE = CFLAGS_KERNEL = AFLAGS_KERNEL = LDFLAGS_vmlinux = -CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,) -CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,) - # Use USERINCLUDE when you must reference the UAPI directories only. USERINCLUDE := \ @@ -413,21 +410,19 @@ LINUXINCLUDE := \ -I$(objtree)/include \ $(USERINCLUDE) -KBUILD_CPPFLAGS := -D__KERNEL__ - +KBUILD_AFLAGS := -D__ASSEMBLY__ KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ -fno-strict-aliasing -fno-common -fshort-wchar \ -Werror-implicit-function-declaration \ -Wno-format-security \ - -std=gnu89 $(call cc-option,-fno-PIE) - - + -std=gnu89 +KBUILD_CPPFLAGS := -D__KERNEL__ KBUILD_AFLAGS_KERNEL := KBUILD_CFLAGS_KERNEL := -KBUILD_AFLAGS := -D__ASSEMBLY__ $(call cc-option,-fno-PIE) KBUILD_AFLAGS_MODULE := -DMODULE KBUILD_CFLAGS_MODULE := -DMODULE KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds +GCC_PLUGINS_CFLAGS := export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC export CPP AR NM STRIP OBJCOPY OBJDUMP HOSTLDFLAGS HOST_LOADLIBES @@ -435,7 +430,7 @@ export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS -export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_GCOV CFLAGS_KCOV CFLAGS_KASAN CFLAGS_UBSAN +export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_KASAN CFLAGS_UBSAN export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL @@ -607,6 +602,12 @@ endif # Defaults to vmlinux, but the arch makefile usually adds further targets all: vmlinux +KBUILD_CFLAGS += $(call cc-option,-fno-PIE) +KBUILD_AFLAGS += $(call cc-option,-fno-PIE) +CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,) +CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,) +export CFLAGS_GCOV CFLAGS_KCOV + # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default # values of the respective KBUILD_* variables ARCH_CPPFLAGS :=
Some $(call cc-option,...) are invoked very early, even before KBUILD_CFLAGS, etc. are initialized. The returned string from $(call cc-option,...) depends on KBUILD_CPPFLAGS, KBUILD_CFLAGS, and GCC_PLUGINS_CFLAGS. Since they are exported, they are not empty when the top Makefile is recursively invoked. The recursion occurs in several places. For example, the top Makefile invokes itself for silentoldconfig. "make tinyconfig", "make rpm-pkg" are the cases, too. In those cases, the second call of cc-option from the same line runs a different shell command due to non-pristine KBUILD_CFLAGS. To get the same result all the time, KBUILD_* and GCC_PLUGINS_CFLAGS must be initialized before any call of cc-option. This avoids garbage data in the .cache.mk file. Move all calls of cc-option below the config targets because target compiler flags are unnecessary for Kconfig. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> --- Makefile | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) -- 2.7.4