Re: [PATCH] kbuild: fix endless syncconfig in case arch Makefile sets CROSS_COMPILE
2018-06-08 17:20 GMT+09:00 Geert Uytterhoeven :
> Hi Yamada-san,
>
> On Fri, Jun 8, 2018 at 2:21 AM, Masahiro Yamada
> wrote:
>> Commit 21c54b774744 ("kconfig: show compiler version text in the top
>> comment") was intended to detect the compiler upgrade, but Geert
>> reported a breakage on the m68k build.
>>
>> The compiler upgrade is detected by the change of the environment
>> variable, CC_VERSION_TEXT, which contains the first line of the output
>> from $(CC) --version. Currently, this works well when CROSS_COMPILE
>> is given via the environment variable or the Make command line.
>>
>> However, some architectures such as m68k can specify CROSS_COMPILE
>> from arch/$(SRCARCH)/Makefile as well. In this case, "make ARCH=m68k"
>> ends up with endless syncconfig loop.
>>
>> $ make ARCH=m68k defconfig
>> *** Default configuration is based on 'multi_defconfig'
>> #
>> # configuration written to .config
>> #
>> $ make ARCH=m68k
>> scripts/kconfig/conf --syncconfig Kconfig
>> scripts/kconfig/conf --syncconfig Kconfig
>> scripts/kconfig/conf --syncconfig Kconfig
>> scripts/kconfig/conf --syncconfig Kconfig
>
> [...]
>
>> Fixes: 21c54b774744 ("kconfig: show compiler version text in the top
>> comment")
>> Reported-by: Geert Uytterhoeven
>> Signed-off-by: Masahiro Yamada
>
> Thanks for fixing this quickly!
>
> Tested-by: Geert Uytterhoeven
Applied to linux-kbuild.
--
Best Regards
Masahiro Yamada
Re: [PATCH] kbuild: fix endless syncconfig in case arch Makefile sets CROSS_COMPILE
2018-06-08 17:20 GMT+09:00 Geert Uytterhoeven :
> Hi Yamada-san,
>
> On Fri, Jun 8, 2018 at 2:21 AM, Masahiro Yamada
> wrote:
>> Commit 21c54b774744 ("kconfig: show compiler version text in the top
>> comment") was intended to detect the compiler upgrade, but Geert
>> reported a breakage on the m68k build.
>>
>> The compiler upgrade is detected by the change of the environment
>> variable, CC_VERSION_TEXT, which contains the first line of the output
>> from $(CC) --version. Currently, this works well when CROSS_COMPILE
>> is given via the environment variable or the Make command line.
>>
>> However, some architectures such as m68k can specify CROSS_COMPILE
>> from arch/$(SRCARCH)/Makefile as well. In this case, "make ARCH=m68k"
>> ends up with endless syncconfig loop.
>>
>> $ make ARCH=m68k defconfig
>> *** Default configuration is based on 'multi_defconfig'
>> #
>> # configuration written to .config
>> #
>> $ make ARCH=m68k
>> scripts/kconfig/conf --syncconfig Kconfig
>> scripts/kconfig/conf --syncconfig Kconfig
>> scripts/kconfig/conf --syncconfig Kconfig
>> scripts/kconfig/conf --syncconfig Kconfig
>
> [...]
>
>> Fixes: 21c54b774744 ("kconfig: show compiler version text in the top
>> comment")
>> Reported-by: Geert Uytterhoeven
>> Signed-off-by: Masahiro Yamada
>
> Thanks for fixing this quickly!
>
> Tested-by: Geert Uytterhoeven
Applied to linux-kbuild.
--
Best Regards
Masahiro Yamada
Re: [PATCH] kbuild: fix endless syncconfig in case arch Makefile sets CROSS_COMPILE
Hi Yamada-san,
On Fri, Jun 8, 2018 at 2:21 AM, Masahiro Yamada
wrote:
> Commit 21c54b774744 ("kconfig: show compiler version text in the top
> comment") was intended to detect the compiler upgrade, but Geert
> reported a breakage on the m68k build.
>
> The compiler upgrade is detected by the change of the environment
> variable, CC_VERSION_TEXT, which contains the first line of the output
> from $(CC) --version. Currently, this works well when CROSS_COMPILE
> is given via the environment variable or the Make command line.
>
> However, some architectures such as m68k can specify CROSS_COMPILE
> from arch/$(SRCARCH)/Makefile as well. In this case, "make ARCH=m68k"
> ends up with endless syncconfig loop.
>
> $ make ARCH=m68k defconfig
> *** Default configuration is based on 'multi_defconfig'
> #
> # configuration written to .config
> #
> $ make ARCH=m68k
> scripts/kconfig/conf --syncconfig Kconfig
> scripts/kconfig/conf --syncconfig Kconfig
> scripts/kconfig/conf --syncconfig Kconfig
> scripts/kconfig/conf --syncconfig Kconfig
[...]
> Fixes: 21c54b774744 ("kconfig: show compiler version text in the top comment")
> Reported-by: Geert Uytterhoeven
> Signed-off-by: Masahiro Yamada
Thanks for fixing this quickly!
Tested-by: Geert Uytterhoeven
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
Re: [PATCH] kbuild: fix endless syncconfig in case arch Makefile sets CROSS_COMPILE
Hi Yamada-san,
On Fri, Jun 8, 2018 at 2:21 AM, Masahiro Yamada
wrote:
> Commit 21c54b774744 ("kconfig: show compiler version text in the top
> comment") was intended to detect the compiler upgrade, but Geert
> reported a breakage on the m68k build.
>
> The compiler upgrade is detected by the change of the environment
> variable, CC_VERSION_TEXT, which contains the first line of the output
> from $(CC) --version. Currently, this works well when CROSS_COMPILE
> is given via the environment variable or the Make command line.
>
> However, some architectures such as m68k can specify CROSS_COMPILE
> from arch/$(SRCARCH)/Makefile as well. In this case, "make ARCH=m68k"
> ends up with endless syncconfig loop.
>
> $ make ARCH=m68k defconfig
> *** Default configuration is based on 'multi_defconfig'
> #
> # configuration written to .config
> #
> $ make ARCH=m68k
> scripts/kconfig/conf --syncconfig Kconfig
> scripts/kconfig/conf --syncconfig Kconfig
> scripts/kconfig/conf --syncconfig Kconfig
> scripts/kconfig/conf --syncconfig Kconfig
[...]
> Fixes: 21c54b774744 ("kconfig: show compiler version text in the top comment")
> Reported-by: Geert Uytterhoeven
> Signed-off-by: Masahiro Yamada
Thanks for fixing this quickly!
Tested-by: Geert Uytterhoeven
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
[PATCH] kbuild: fix endless syncconfig in case arch Makefile sets CROSS_COMPILE
Commit 21c54b774744 ("kconfig: show compiler version text in the top
comment") was intended to detect the compiler upgrade, but Geert
reported a breakage on the m68k build.
The compiler upgrade is detected by the change of the environment
variable, CC_VERSION_TEXT, which contains the first line of the output
from $(CC) --version. Currently, this works well when CROSS_COMPILE
is given via the environment variable or the Make command line.
However, some architectures such as m68k can specify CROSS_COMPILE
from arch/$(SRCARCH)/Makefile as well. In this case, "make ARCH=m68k"
ends up with endless syncconfig loop.
$ make ARCH=m68k defconfig
*** Default configuration is based on 'multi_defconfig'
#
# configuration written to .config
#
$ make ARCH=m68k
scripts/kconfig/conf --syncconfig Kconfig
scripts/kconfig/conf --syncconfig Kconfig
scripts/kconfig/conf --syncconfig Kconfig
scripts/kconfig/conf --syncconfig Kconfig
Things are happening like this:
Because arch/$(SRCARCH)/Makefile is included after CC_VERSION_TEXT
is set, it contains the host compiler version in the defconfig phase.
To create or update auto.conf, the following line is triggered:
include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
This recurses the top Makefile after arch/$(SRCARCH)/Makefile is
included. CROSS_COMPILE is set to a m68k toolchain prefix and
exported to the recursed Make. Then, syncconfig is invoked with
the target compiler version in CC_VERSION_TEXT.
The Make will restart because auto.conf and auto.conf.cmd have been
updated. At this point, CROSS_COMPILE is reset, so CC_VERSION_TEXT
is set to the host compiler version again. Then, syncconfig is
triggered due to the change of CC_VERSION_TEXT. This loop continues
eternally.
To fix this problem, $(CC_VERSION_TEXT) must be evaluated only after
arch/$(SRCARCH)/Makefile. Setting it earlier is OK as long as it is
defined by using the '=' operator instead of ':='.
For the defconfig phase, $(CC_VERSION_TEXT) is evaluated when Kbuild
descends into scripts/kconfig/, so it contains the target compiler
version correctly.
include/config/auto.conf.cmd references $(CC_VERSION_TEXT) as well,
so it must be included after arch/$(SRCARCH)/Makefile.
Fixes: 21c54b774744 ("kconfig: show compiler version text in the top comment")
Reported-by: Geert Uytterhoeven
Signed-off-by: Masahiro Yamada
---
Makefile | 54 ++
1 file changed, 30 insertions(+), 24 deletions(-)
diff --git a/Makefile b/Makefile
index 019a5a0..747edaf 100644
--- a/Makefile
+++ b/Makefile
@@ -442,8 +442,6 @@ export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE
KBUILD_LDFLAGS_MODULE
export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
export KBUILD_ARFLAGS
-export CC_VERSION_TEXT := $(shell $(CC) --version | head -n 1)
-
# When compiling out-of-tree modules, put MODVERDIR in the module
# tree rather than in the kernel tree. The kernel tree might
# even be read-only.
@@ -514,6 +512,12 @@ ifeq ($(shell $(CONFIG_SHELL)
$(srctree)/scripts/cc-can-link.sh $(CC)), y)
export CC_CAN_LINK
endif
+# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
+# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
+# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
+# and from include/config/auto.conf.cmd to detect the compiler upgrade.
+CC_VERSION_TEXT = $(shell $(CC) --version | head -n 1)
+
ifeq ($(config-targets),1)
# ===
# *config targets only - make sure prerequisites are updated, and descend
@@ -523,7 +527,7 @@ ifeq ($(config-targets),1)
# KBUILD_DEFCONFIG may point out an alternative default configuration
# used for 'make defconfig'
include arch/$(SRCARCH)/Makefile
-export KBUILD_DEFCONFIG KBUILD_KCONFIG
+export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
config: scripts_basic outputmakefile FORCE
$(Q)$(MAKE) $(build)=scripts/kconfig $@
@@ -585,12 +589,32 @@ virt-y:= virt/
endif # KBUILD_EXTMOD
ifeq ($(dot-config),1)
-# Read in config
-include include/config/auto.conf
+endif
+
+# The all: target is the default when no target is given on the
+# command line.
+# This allow a user to issue only 'make' to build a kernel including modules
+# Defaults to vmlinux, but the arch makefile usually adds further targets
+all: vmlinux
+
+CFLAGS_GCOV:= -fprofile-arcs -ftest-coverage \
+ $(call cc-option,-fno-tree-loop-im) \
+ $(call cc-disable-warning,maybe-uninitialized,)
+export CFLAGS_GCOV CFLAGS_KCOV
+
+# The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
+# values of the respective KBUILD_* variables
+ARCH_CPPFLAGS :=
+ARCH_AFLAGS :=
+ARCH_CFLAGS :=
+include arch/$(SRCARCH)/Makefile
+ifeq ($(dot-config),1)
ifeq ($(KBUILD_EXTMOD),)
-# Read in dependencies to all Kconfig* files, make sure
[PATCH] kbuild: fix endless syncconfig in case arch Makefile sets CROSS_COMPILE
Commit 21c54b774744 ("kconfig: show compiler version text in the top
comment") was intended to detect the compiler upgrade, but Geert
reported a breakage on the m68k build.
The compiler upgrade is detected by the change of the environment
variable, CC_VERSION_TEXT, which contains the first line of the output
from $(CC) --version. Currently, this works well when CROSS_COMPILE
is given via the environment variable or the Make command line.
However, some architectures such as m68k can specify CROSS_COMPILE
from arch/$(SRCARCH)/Makefile as well. In this case, "make ARCH=m68k"
ends up with endless syncconfig loop.
$ make ARCH=m68k defconfig
*** Default configuration is based on 'multi_defconfig'
#
# configuration written to .config
#
$ make ARCH=m68k
scripts/kconfig/conf --syncconfig Kconfig
scripts/kconfig/conf --syncconfig Kconfig
scripts/kconfig/conf --syncconfig Kconfig
scripts/kconfig/conf --syncconfig Kconfig
Things are happening like this:
Because arch/$(SRCARCH)/Makefile is included after CC_VERSION_TEXT
is set, it contains the host compiler version in the defconfig phase.
To create or update auto.conf, the following line is triggered:
include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
This recurses the top Makefile after arch/$(SRCARCH)/Makefile is
included. CROSS_COMPILE is set to a m68k toolchain prefix and
exported to the recursed Make. Then, syncconfig is invoked with
the target compiler version in CC_VERSION_TEXT.
The Make will restart because auto.conf and auto.conf.cmd have been
updated. At this point, CROSS_COMPILE is reset, so CC_VERSION_TEXT
is set to the host compiler version again. Then, syncconfig is
triggered due to the change of CC_VERSION_TEXT. This loop continues
eternally.
To fix this problem, $(CC_VERSION_TEXT) must be evaluated only after
arch/$(SRCARCH)/Makefile. Setting it earlier is OK as long as it is
defined by using the '=' operator instead of ':='.
For the defconfig phase, $(CC_VERSION_TEXT) is evaluated when Kbuild
descends into scripts/kconfig/, so it contains the target compiler
version correctly.
include/config/auto.conf.cmd references $(CC_VERSION_TEXT) as well,
so it must be included after arch/$(SRCARCH)/Makefile.
Fixes: 21c54b774744 ("kconfig: show compiler version text in the top comment")
Reported-by: Geert Uytterhoeven
Signed-off-by: Masahiro Yamada
---
Makefile | 54 ++
1 file changed, 30 insertions(+), 24 deletions(-)
diff --git a/Makefile b/Makefile
index 019a5a0..747edaf 100644
--- a/Makefile
+++ b/Makefile
@@ -442,8 +442,6 @@ export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE
KBUILD_LDFLAGS_MODULE
export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
export KBUILD_ARFLAGS
-export CC_VERSION_TEXT := $(shell $(CC) --version | head -n 1)
-
# When compiling out-of-tree modules, put MODVERDIR in the module
# tree rather than in the kernel tree. The kernel tree might
# even be read-only.
@@ -514,6 +512,12 @@ ifeq ($(shell $(CONFIG_SHELL)
$(srctree)/scripts/cc-can-link.sh $(CC)), y)
export CC_CAN_LINK
endif
+# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
+# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
+# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
+# and from include/config/auto.conf.cmd to detect the compiler upgrade.
+CC_VERSION_TEXT = $(shell $(CC) --version | head -n 1)
+
ifeq ($(config-targets),1)
# ===
# *config targets only - make sure prerequisites are updated, and descend
@@ -523,7 +527,7 @@ ifeq ($(config-targets),1)
# KBUILD_DEFCONFIG may point out an alternative default configuration
# used for 'make defconfig'
include arch/$(SRCARCH)/Makefile
-export KBUILD_DEFCONFIG KBUILD_KCONFIG
+export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
config: scripts_basic outputmakefile FORCE
$(Q)$(MAKE) $(build)=scripts/kconfig $@
@@ -585,12 +589,32 @@ virt-y:= virt/
endif # KBUILD_EXTMOD
ifeq ($(dot-config),1)
-# Read in config
-include include/config/auto.conf
+endif
+
+# The all: target is the default when no target is given on the
+# command line.
+# This allow a user to issue only 'make' to build a kernel including modules
+# Defaults to vmlinux, but the arch makefile usually adds further targets
+all: vmlinux
+
+CFLAGS_GCOV:= -fprofile-arcs -ftest-coverage \
+ $(call cc-option,-fno-tree-loop-im) \
+ $(call cc-disable-warning,maybe-uninitialized,)
+export CFLAGS_GCOV CFLAGS_KCOV
+
+# The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
+# values of the respective KBUILD_* variables
+ARCH_CPPFLAGS :=
+ARCH_AFLAGS :=
+ARCH_CFLAGS :=
+include arch/$(SRCARCH)/Makefile
+ifeq ($(dot-config),1)
ifeq ($(KBUILD_EXTMOD),)
-# Read in dependencies to all Kconfig* files, make sure
