The patch titled Subject: tools: fix cross-compile var clobbering has been removed from the -mm tree. Its filename was tools-fix-cross-compile-var-clobbering.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Martin Kelly <martin@xxxxxxxxxxxxxxxx> Subject: tools: fix cross-compile var clobbering Currently a number of Makefiles break when used with toolchains that pass extra flags in CC and other cross-compile related variables (such as --sysroot). Thus we get this error when we use a toolchain that puts --sysroot in the CC var: ~/src/linux/tools$ make iio [snip] iio_event_monitor.c:18:10: fatal error: unistd.h: No such file or directory #include <unistd.h> ^~~~~~~~~~ This occurs because we clobber several env vars related to cross-compiling with lines like this: CC = $(CROSS_COMPILE)gcc Although this will point to a valid cross-compiler, we lose any extra flags that might exist in the CC variable, which can break toolchains that rely on them (for example, those that use --sysroot). This easily shows up using a Yocto SDK: $ . [snip]/sdk/environment-setup-cortexa8hf-neon-poky-linux-gnueabi $ echo $CC arm-poky-linux-gnueabi-gcc -march=armv7-a -mfpu=neon -mfloat-abi=hard -mcpu=cortex-a8 --sysroot=[snip]/sdk/sysroots/cortexa8hf-neon-poky-linux-gnueabi $ echo $CROSS_COMPILE arm-poky-linux-gnueabi- $ echo ${CROSS_COMPILE}gcc krm-poky-linux-gnueabi-gcc Although arm-poky-linux-gnueabi-gcc is a cross-compiler, we've lost the --sysroot and other flags that enable us to find the right libraries to link against, so we can't find unistd.h and other libraries and headers. Normally with the --sysroot flag we would find unistd.h in the sdk directory in the sysroot: $ find [snip]/sdk/sysroots -path '*/usr/include/unistd.h' [snip]/sdk/sysroots/cortexa8hf-neon-poky-linux-gnueabi/usr/include/unistd.h The perf Makefile adds CC = $(CROSS_COMPILE)gcc if and only if CC is not already set, and it compiles correctly with the above toolchain. So, generalize the logic that perf uses in the common Makefile and remove the manual CC = $(CROSS_COMPILE)gcc lines from each Makefile. Note that this patch does not fix cross-compile for all the tools (some have other bugs), but it does fix it for all except usb and acpi, which still have other unrelated issues. I tested both with and without the patch on native and cross-build and there appear to be no regressions. Link: http://lkml.kernel.org/r/20180107214028.23771-1-martin@xxxxxxxxxxxxxxxx Signed-off-by: Martin Kelly <martin@xxxxxxxxxxxxxxxx> Acked-by: Mark Brown <broonie@xxxxxxxxxx> Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Li Zefan <lizefan@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx> Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx> Cc: Jonathan Cameron <jic23@xxxxxxxxxx> Cc: Pali Rohar <pali.rohar@xxxxxxxxx> Cc: Richard Purdie <rpurdie@xxxxxxxxx> Cc: Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx> Cc: Pavel Machek <pavel@xxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Cc: Robert Moore <robert.moore@xxxxxxxxx> Cc: Lv Zheng <lv.zheng@xxxxxxxxx> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Valentina Manea <valentina.manea.m@xxxxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Cc: Mario Limonciello <mario.limonciello@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- tools/cgroup/Makefile | 1 - tools/gpio/Makefile | 2 -- tools/hv/Makefile | 1 - tools/iio/Makefile | 2 -- tools/laptop/freefall/Makefile | 1 - tools/leds/Makefile | 1 - tools/perf/Makefile.perf | 6 ------ tools/power/acpi/Makefile.config | 3 --- tools/scripts/Makefile.include | 18 ++++++++++++++++++ tools/spi/Makefile | 2 -- tools/usb/Makefile | 1 - tools/vm/Makefile | 1 - tools/wmi/Makefile | 1 - 13 files changed, 18 insertions(+), 22 deletions(-) diff -puN tools/cgroup/Makefile~tools-fix-cross-compile-var-clobbering tools/cgroup/Makefile --- a/tools/cgroup/Makefile~tools-fix-cross-compile-var-clobbering +++ a/tools/cgroup/Makefile @@ -1,7 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 # Makefile for cgroup tools -CC = $(CROSS_COMPILE)gcc CFLAGS = -Wall -Wextra all: cgroup_event_listener diff -puN tools/gpio/Makefile~tools-fix-cross-compile-var-clobbering tools/gpio/Makefile --- a/tools/gpio/Makefile~tools-fix-cross-compile-var-clobbering +++ a/tools/gpio/Makefile @@ -12,8 +12,6 @@ endif # (this improves performance and avoids hard-to-debug behaviour); MAKEFLAGS += -r -CC = $(CROSS_COMPILE)gcc -LD = $(CROSS_COMPILE)ld CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include ALL_TARGETS := lsgpio gpio-hammer gpio-event-mon diff -puN tools/hv/Makefile~tools-fix-cross-compile-var-clobbering tools/hv/Makefile --- a/tools/hv/Makefile~tools-fix-cross-compile-var-clobbering +++ a/tools/hv/Makefile @@ -1,7 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 # Makefile for Hyper-V tools -CC = $(CROSS_COMPILE)gcc WARNINGS = -Wall -Wextra CFLAGS = $(WARNINGS) -g $(shell getconf LFS_CFLAGS) diff -puN tools/iio/Makefile~tools-fix-cross-compile-var-clobbering tools/iio/Makefile --- a/tools/iio/Makefile~tools-fix-cross-compile-var-clobbering +++ a/tools/iio/Makefile @@ -12,8 +12,6 @@ endif # (this improves performance and avoids hard-to-debug behaviour); MAKEFLAGS += -r -CC = $(CROSS_COMPILE)gcc -LD = $(CROSS_COMPILE)ld CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include ALL_TARGETS := iio_event_monitor lsiio iio_generic_buffer diff -puN tools/laptop/freefall/Makefile~tools-fix-cross-compile-var-clobbering tools/laptop/freefall/Makefile --- a/tools/laptop/freefall/Makefile~tools-fix-cross-compile-var-clobbering +++ a/tools/laptop/freefall/Makefile @@ -2,7 +2,6 @@ PREFIX ?= /usr SBINDIR ?= sbin INSTALL ?= install -CC = $(CROSS_COMPILE)gcc TARGET = freefall diff -puN tools/leds/Makefile~tools-fix-cross-compile-var-clobbering tools/leds/Makefile --- a/tools/leds/Makefile~tools-fix-cross-compile-var-clobbering +++ a/tools/leds/Makefile @@ -1,7 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 # Makefile for LEDs tools -CC = $(CROSS_COMPILE)gcc CFLAGS = -Wall -Wextra -g -I../../include/uapi all: uledmon led_hw_brightness_mon diff -puN tools/perf/Makefile.perf~tools-fix-cross-compile-var-clobbering tools/perf/Makefile.perf --- a/tools/perf/Makefile.perf~tools-fix-cross-compile-var-clobbering +++ a/tools/perf/Makefile.perf @@ -146,12 +146,6 @@ define allow-override $(eval $(1) = $(2))) endef -# Allow setting CC and AR and LD, or setting CROSS_COMPILE as a prefix. -$(call allow-override,CC,$(CROSS_COMPILE)gcc) -$(call allow-override,AR,$(CROSS_COMPILE)ar) -$(call allow-override,LD,$(CROSS_COMPILE)ld) -$(call allow-override,CXX,$(CROSS_COMPILE)g++) - LD += $(EXTRA_LDFLAGS) HOSTCC ?= gcc diff -puN tools/power/acpi/Makefile.config~tools-fix-cross-compile-var-clobbering tools/power/acpi/Makefile.config --- a/tools/power/acpi/Makefile.config~tools-fix-cross-compile-var-clobbering +++ a/tools/power/acpi/Makefile.config @@ -56,9 +56,6 @@ INSTALL_SCRIPT = ${INSTALL_PROGRAM} # to compile vs uClibc, that can be done here as well. CROSS = #/usr/i386-linux-uclibc/usr/bin/i386-uclibc- CROSS_COMPILE ?= $(CROSS) -CC = $(CROSS_COMPILE)gcc -LD = $(CROSS_COMPILE)gcc -STRIP = $(CROSS_COMPILE)strip HOSTCC = gcc # check if compiler option is supported diff -puN tools/scripts/Makefile.include~tools-fix-cross-compile-var-clobbering tools/scripts/Makefile.include --- a/tools/scripts/Makefile.include~tools-fix-cross-compile-var-clobbering +++ a/tools/scripts/Makefile.include @@ -42,6 +42,24 @@ EXTRA_WARNINGS += -Wformat CC_NO_CLANG := $(shell $(CC) -dM -E -x c /dev/null | grep -Fq "__clang__"; echo $$?) +# Makefiles suck: This macro sets a default value of $(2) for the +# variable named by $(1), unless the variable has been set by +# environment or command line. This is necessary for CC and AR +# because make sets default values, so the simpler ?= approach +# won't work as expected. +define allow-override + $(if $(or $(findstring environment,$(origin $(1))),\ + $(findstring command line,$(origin $(1)))),,\ + $(eval $(1) = $(2))) +endef + +# Allow setting various cross-compile vars or setting CROSS_COMPILE as a prefix. +$(call allow-override,CC,$(CROSS_COMPILE)gcc) +$(call allow-override,AR,$(CROSS_COMPILE)ar) +$(call allow-override,LD,$(CROSS_COMPILE)ld) +$(call allow-override,CXX,$(CROSS_COMPILE)g++) +$(call allow-override,STRIP,$(CROSS_COMPILE)strip) + ifeq ($(CC_NO_CLANG), 1) EXTRA_WARNINGS += -Wstrict-aliasing=3 endif diff -puN tools/spi/Makefile~tools-fix-cross-compile-var-clobbering tools/spi/Makefile --- a/tools/spi/Makefile~tools-fix-cross-compile-var-clobbering +++ a/tools/spi/Makefile @@ -11,8 +11,6 @@ endif # (this improves performance and avoids hard-to-debug behaviour); MAKEFLAGS += -r -CC = $(CROSS_COMPILE)gcc -LD = $(CROSS_COMPILE)ld CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include ALL_TARGETS := spidev_test spidev_fdx diff -puN tools/usb/Makefile~tools-fix-cross-compile-var-clobbering tools/usb/Makefile --- a/tools/usb/Makefile~tools-fix-cross-compile-var-clobbering +++ a/tools/usb/Makefile @@ -1,7 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 # Makefile for USB tools -CC = $(CROSS_COMPILE)gcc PTHREAD_LIBS = -lpthread WARNINGS = -Wall -Wextra CFLAGS = $(WARNINGS) -g -I../include diff -puN tools/vm/Makefile~tools-fix-cross-compile-var-clobbering tools/vm/Makefile --- a/tools/vm/Makefile~tools-fix-cross-compile-var-clobbering +++ a/tools/vm/Makefile @@ -6,7 +6,6 @@ TARGETS=page-types slabinfo page_owner_s LIB_DIR = ../lib/api LIBS = $(LIB_DIR)/libapi.a -CC = $(CROSS_COMPILE)gcc CFLAGS = -Wall -Wextra -I../lib/ LDFLAGS = $(LIBS) diff -puN tools/wmi/Makefile~tools-fix-cross-compile-var-clobbering tools/wmi/Makefile --- a/tools/wmi/Makefile~tools-fix-cross-compile-var-clobbering +++ a/tools/wmi/Makefile @@ -2,7 +2,6 @@ PREFIX ?= /usr SBINDIR ?= sbin INSTALL ?= install CFLAGS += -D__EXPORTED_HEADERS__ -I../../include/uapi -I../../include -CC = $(CROSS_COMPILE)gcc TARGET = dell-smbios-example _ Patches currently in -mm which might be from martin@xxxxxxxxxxxxxxxx are -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html