From e6148767825ce345338328a29030a182e3b22d10 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 18 Jun 2021 23:30:07 -0700 Subject: Makefile: Enable -Warray-bounds With the recent fixes for flexible arrays and expanded FORTIFY_SOURCE coverage, it is now possible to enable -Warray-bounds. Since both GCC and Clang include -Warray-bounds in -Wall, adjust the Makefile to just stop disabling it. Note that this option can be conservative in its warnings (which is done at casting time rather than access time), but this is reasonable since the cast variables may be accessed out of a scope where the true size of the original object can't be evaluated. These handful of false positives (which are arguably bad casts and can be easily avoided), are worth dealing with because of the many places where this option has helped identify missed bounds checks and even accesses done against cases where a NULL pointer could be reached. https://github.com/KSPP/linux/issues/109 https://github.com/KSPP/linux/issues/151 Cc: Arnd Bergmann Cc: Masahiro Yamada Cc: linux-kbuild@vger.kernel.org Co-developed-by: Gustavo A. R. Silva Signed-off-by: Gustavo A. R. Silva Signed-off-by: Kees Cook --- Makefile | 1 - 1 file changed, 1 deletion(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index ceb987e5c87b..d66b61691e8c 100644 --- a/Makefile +++ b/Makefile @@ -952,7 +952,6 @@ KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation) # We'll want to enable this eventually, but it's not going away for 5.7 at least KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds) -KBUILD_CFLAGS += -Wno-array-bounds KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow) # Another good warning that we'll want to enable eventually -- cgit v1.2.3-58-ga151 From 00a4f836eb369723b148e3f250c850a028778832 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 17 Aug 2021 11:56:36 -0700 Subject: Makefile: Enable -Wzero-length-bounds With all known internal zero-length accesses fixed, it is possible to enable -Wzero-length-bounds globally. Since this is included by default in -Warray-bounds, we just need to stop disabling it. Cc: "Gustavo A. R. Silva" Cc: Arnd Bergmann Cc: Masahiro Yamada Cc: linux-kbuild@vger.kernel.org Signed-off-by: Kees Cook Reviewed-by: Nick Desaulniers Link: https://lore.kernel.org/lkml/CAKwvOd=bcs5W6eEDXGn5ROR2EuMiSp_2e6sLFxak=KK6yLWcvA@mail.gmail.com --- Makefile | 1 - 1 file changed, 1 deletion(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index d66b61691e8c..8e2e4edf7e71 100644 --- a/Makefile +++ b/Makefile @@ -951,7 +951,6 @@ KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type) KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation) # We'll want to enable this eventually, but it's not going away for 5.7 at least -KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds) KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow) # Another good warning that we'll want to enable eventually -- cgit v1.2.3-58-ga151 From f67695c9962e5f444549b3437fb8d840ec6222c8 Mon Sep 17 00:00:00 2001 From: Elliot Berman Date: Tue, 1 Feb 2022 13:35:42 -0800 Subject: kbuild: Add environment variables for userprogs flags Allow additional arguments be passed to userprogs compilation. Reproducible clang builds need to provide a sysroot and gcc path to ensure the same toolchain is used across hosts. KCFLAGS is not currently used for any user programs compilation, so add new USERCFLAGS and USERLDFLAGS which serves similar purpose as HOSTCFLAGS/HOSTLDFLAGS. Clang might detect GCC installation on hosts which have it installed to a default location in /. With addition of these environment variables, you can specify flags such as: $ make USERCFLAGS=--sysroot=/path/to/sysroot This can also be used to specify different sysroots such as musl or bionic which may be installed on the host in paths that the compiler may not search by default. Signed-off-by: Elliot Berman Reviewed-by: Nick Desaulniers Reviewed-by: Fangrui Song Signed-off-by: Masahiro Yamada --- Documentation/kbuild/kbuild.rst | 11 +++++++++++ Documentation/kbuild/makefiles.rst | 2 ++ Makefile | 10 ++++++---- init/Kconfig | 8 ++++---- usr/include/Makefile | 3 +++ 5 files changed, 26 insertions(+), 8 deletions(-) (limited to 'Makefile') diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst index 2d1fc03d346e..ef19b9c13523 100644 --- a/Documentation/kbuild/kbuild.rst +++ b/Documentation/kbuild/kbuild.rst @@ -77,6 +77,17 @@ HOSTLDLIBS ---------- Additional libraries to link against when building host programs. +.. _userkbuildflags: + +USERCFLAGS +---------- +Additional options used for $(CC) when compiling userprogs. + +USERLDFLAGS +----------- +Additional options used for $(LD) when linking userprogs. userprogs are linked +with CC, so $(USERLDFLAGS) should include "-Wl," prefix as applicable. + KBUILD_KCONFIG -------------- Set the top-level Kconfig file to the value of this environment diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst index b008b90b92c9..11a296e52d68 100644 --- a/Documentation/kbuild/makefiles.rst +++ b/Documentation/kbuild/makefiles.rst @@ -982,6 +982,8 @@ The syntax is quite similar. The difference is to use "userprogs" instead of When linking bpfilter_umh, it will be passed the extra option -static. + From command line, :ref:`USERCFLAGS and USERLDFLAGS ` will also be used. + 5.4 When userspace programs are actually built ---------------------------------------------- diff --git a/Makefile b/Makefile index 51e142f760f7..351f043e133a 100644 --- a/Makefile +++ b/Makefile @@ -431,11 +431,12 @@ HOSTCC = gcc HOSTCXX = g++ endif -export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \ - -O2 -fomit-frame-pointer -std=gnu89 -export KBUILD_USERLDFLAGS := +KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \ + -O2 -fomit-frame-pointer -std=gnu89 +KBUILD_USERCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS) +KBUILD_USERLDFLAGS := $(USERLDFLAGS) -KBUILD_HOSTCFLAGS := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS) +KBUILD_HOSTCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS) KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS) KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS) KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS) @@ -530,6 +531,7 @@ export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AW export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE +export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE diff --git a/init/Kconfig b/init/Kconfig index e9119bf54b1f..a2f881cc84d6 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -62,13 +62,13 @@ config LLD_VERSION config CC_CAN_LINK bool - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag)) if 64BIT - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag)) + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag)) if 64BIT + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag)) config CC_CAN_LINK_STATIC bool - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag) -static) if 64BIT - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag) -static) + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag) -static) if 64BIT + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag) -static) config CC_HAS_ASM_GOTO def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC)) diff --git a/usr/include/Makefile b/usr/include/Makefile index 83822c33e9e7..5bc0d566cfe0 100644 --- a/usr/include/Makefile +++ b/usr/include/Makefile @@ -12,6 +12,9 @@ UAPI_CFLAGS := -std=c90 -Wall -Werror=implicit-function-declaration # It is here just because CONFIG_CC_CAN_LINK is tested with -m32 or -m64. UAPI_CFLAGS += $(filter -m32 -m64, $(KBUILD_CFLAGS)) +# USERCFLAGS might contain sysroot location for CC. +UAPI_CFLAGS += $(USERCFLAGS) + override c_flags = $(UAPI_CFLAGS) -Wp,-MMD,$(depfile) -I$(objtree)/usr/include # The following are excluded for now because they fail to build. -- cgit v1.2.3-58-ga151 From 5c8166419acf468b5bc3e48f928a040485d3e0c2 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 11 Feb 2022 14:14:11 +0900 Subject: kbuild: replace $(if A,A,B) with $(or A,B) $(or ...) is available since GNU Make 3.81, and useful to shorten the code in some places. Covert as follows: $(if A,A,B) --> $(or A,B) This patch also converts: $(if A, A, B) --> $(or A, B) Strictly speaking, the latter is not an equivalent conversion because GNU Make keeps spaces after commas; if A is not empty, $(if A, A, B) expands to " A", while $(or A, B) expands to "A". Anyway, preceding spaces are not significant in the code hunks I touched. Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier --- Makefile | 8 ++++---- scripts/Makefile.build | 3 +-- scripts/Makefile.clean | 2 +- scripts/Makefile.lib | 4 ++-- tools/bpf/bpftool/Makefile | 4 ++-- tools/build/Makefile | 2 +- tools/counter/Makefile | 2 +- tools/gpio/Makefile | 2 +- tools/hv/Makefile | 2 +- tools/iio/Makefile | 2 +- tools/lib/api/Makefile | 2 +- tools/lib/bpf/Makefile | 2 +- tools/lib/perf/Makefile | 2 +- tools/lib/subcmd/Makefile | 2 +- tools/objtool/Makefile | 2 +- tools/pci/Makefile | 2 +- tools/perf/Makefile.perf | 4 ++-- tools/power/x86/intel-speed-select/Makefile | 2 +- tools/scripts/utilities.mak | 2 +- tools/spi/Makefile | 6 +++--- tools/tracing/rtla/Makefile | 2 +- tools/usb/Makefile | 2 +- 22 files changed, 30 insertions(+), 31 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 351f043e133a..a82095c69fdd 100644 --- a/Makefile +++ b/Makefile @@ -1240,8 +1240,8 @@ define filechk_version.h echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL) endef -$(version_h): PATCHLEVEL := $(if $(PATCHLEVEL), $(PATCHLEVEL), 0) -$(version_h): SUBLEVEL := $(if $(SUBLEVEL), $(SUBLEVEL), 0) +$(version_h): PATCHLEVEL := $(or $(PATCHLEVEL), 0) +$(version_h): SUBLEVEL := $(or $(SUBLEVEL), 0) $(version_h): FORCE $(call filechk,version.h) @@ -1624,7 +1624,7 @@ help: @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp @echo '' @echo 'Architecture specific targets ($(SRCARCH)):' - @$(if $(archhelp),$(archhelp),\ + @$(or $(archhelp),\ echo ' No architecture specific help defined for $(SRCARCH)') @echo '' @$(if $(boards), \ @@ -1841,7 +1841,7 @@ $(clean-dirs): clean: $(clean-dirs) $(call cmd,rmfiles) - @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \ + @find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \ \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \ -o -name '*.ko.*' \ -o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \ diff --git a/scripts/Makefile.build b/scripts/Makefile.build index a4b89b757287..7e177d0ee02d 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -40,8 +40,7 @@ include $(srctree)/scripts/Makefile.compiler # The filename Kbuild has precedence over Makefile kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src)) -kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile) -include $(kbuild-file) +include $(or $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Makefile) include $(srctree)/scripts/Makefile.lib diff --git a/scripts/Makefile.clean b/scripts/Makefile.clean index fd6175322470..74cb1c5c3658 100644 --- a/scripts/Makefile.clean +++ b/scripts/Makefile.clean @@ -12,7 +12,7 @@ include $(srctree)/scripts/Kbuild.include # The filename Kbuild has precedence over Makefile kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src)) -include $(if $(wildcard $(kbuild-dir)/Kbuild), $(kbuild-dir)/Kbuild, $(kbuild-dir)/Makefile) +include $(or $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Makefile) # Figure out what we need to build from the various variables # ========================================================================== diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 40735a3adb54..49377d2c2d20 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -111,7 +111,7 @@ subdir-ym := $(addprefix $(obj)/,$(subdir-ym)) modname-multi = $(sort $(foreach m,$(multi-obj-ym),\ $(if $(filter $*.o, $(call suffix-search, $m, .o, -objs -y -m)),$(m:.o=)))) -__modname = $(if $(modname-multi),$(modname-multi),$(basetarget)) +__modname = $(or $(modname-multi),$(basetarget)) modname = $(subst $(space),:,$(__modname)) modfile = $(addprefix $(obj)/,$(__modname)) @@ -434,7 +434,7 @@ MKIMAGE := $(srctree)/scripts/mkuboot.sh # SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces # the number of overrides in arch makefiles UIMAGE_ARCH ?= $(SRCARCH) -UIMAGE_COMPRESSION ?= $(if $(2),$(2),none) +UIMAGE_COMPRESSION ?= $(or $(2),none) UIMAGE_OPTS-y ?= UIMAGE_TYPE ?= kernel UIMAGE_LOADADDR ?= arch_must_set_this diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile index 83369f55df61..ebd21a609910 100644 --- a/tools/bpf/bpftool/Makefile +++ b/tools/bpf/bpftool/Makefile @@ -78,7 +78,7 @@ CFLAGS += -O2 CFLAGS += -W -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers CFLAGS += $(filter-out -Wswitch-enum -Wnested-externs,$(EXTRA_WARNINGS)) CFLAGS += -DPACKAGE='"bpftool"' -D__EXPORTED_HEADERS__ \ - -I$(if $(OUTPUT),$(OUTPUT),.) \ + -I$(or $(OUTPUT),.) \ -I$(LIBBPF_INCLUDE) \ -I$(srctree)/kernel/bpf/ \ -I$(srctree)/tools/include \ @@ -186,7 +186,7 @@ endif $(OUTPUT)%.bpf.o: skeleton/%.bpf.c $(OUTPUT)vmlinux.h $(LIBBPF_BOOTSTRAP) $(QUIET_CLANG)$(CLANG) \ - -I$(if $(OUTPUT),$(OUTPUT),.) \ + -I$(or $(OUTPUT),.) \ -I$(srctree)/tools/include/uapi/ \ -I$(LIBBPF_BOOTSTRAP_INCLUDE) \ -g -O2 -Wall -target bpf -c $< -o $@ diff --git a/tools/build/Makefile b/tools/build/Makefile index 6f11e6fc9ffe..17cdf01e29a0 100644 --- a/tools/build/Makefile +++ b/tools/build/Makefile @@ -36,7 +36,7 @@ TMP_O := $(if $(OUTPUT),$(OUTPUT)feature/,./) clean: $(call QUIET_CLEAN, fixdep) - $(Q)find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete + $(Q)find $(or $(OUTPUT),.) -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete $(Q)rm -f $(OUTPUT)fixdep $(call QUIET_CLEAN, feature-detect) ifneq ($(wildcard $(TMP_O)),) diff --git a/tools/counter/Makefile b/tools/counter/Makefile index 5ebc195fd9c0..8843f0fa6119 100644 --- a/tools/counter/Makefile +++ b/tools/counter/Makefile @@ -40,7 +40,7 @@ $(OUTPUT)counter_example: $(COUNTER_EXAMPLE) clean: rm -f $(ALL_PROGRAMS) rm -rf $(OUTPUT)include/linux/counter.h - find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete + find $(or $(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete install: $(ALL_PROGRAMS) install -d -m 755 $(DESTDIR)$(bindir); \ diff --git a/tools/gpio/Makefile b/tools/gpio/Makefile index 440434027557..d29c9c49e251 100644 --- a/tools/gpio/Makefile +++ b/tools/gpio/Makefile @@ -78,7 +78,7 @@ $(OUTPUT)gpio-watch: $(GPIO_WATCH_IN) clean: rm -f $(ALL_PROGRAMS) rm -f $(OUTPUT)include/linux/gpio.h - find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete + find $(or $(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete install: $(ALL_PROGRAMS) install -d -m 755 $(DESTDIR)$(bindir); \ diff --git a/tools/hv/Makefile b/tools/hv/Makefile index b57143d9459c..fe770e679ae8 100644 --- a/tools/hv/Makefile +++ b/tools/hv/Makefile @@ -47,7 +47,7 @@ $(OUTPUT)hv_fcopy_daemon: $(HV_FCOPY_DAEMON_IN) clean: rm -f $(ALL_PROGRAMS) - find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete + find $(or $(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete install: $(ALL_PROGRAMS) install -d -m 755 $(DESTDIR)$(sbindir); \ diff --git a/tools/iio/Makefile b/tools/iio/Makefile index 5d12ac4e7f8f..fa720f062229 100644 --- a/tools/iio/Makefile +++ b/tools/iio/Makefile @@ -58,7 +58,7 @@ $(OUTPUT)iio_generic_buffer: $(IIO_GENERIC_BUFFER_IN) clean: rm -f $(ALL_PROGRAMS) rm -rf $(OUTPUT)include/linux/iio - find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete + find $(or $(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete install: $(ALL_PROGRAMS) install -d -m 755 $(DESTDIR)$(bindir); \ diff --git a/tools/lib/api/Makefile b/tools/lib/api/Makefile index a13e9c7f1fc5..e21e1b40b525 100644 --- a/tools/lib/api/Makefile +++ b/tools/lib/api/Makefile @@ -60,7 +60,7 @@ $(LIBFILE): $(API_IN) clean: $(call QUIET_CLEAN, libapi) $(RM) $(LIBFILE); \ - find $(if $(OUTPUT),$(OUTPUT),.) -name \*.o -or -name \*.o.cmd -or -name \*.o.d | xargs $(RM) + find $(or $(OUTPUT),.) -name \*.o -or -name \*.o.cmd -or -name \*.o.d | xargs $(RM) FORCE: diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index f947b61b2107..36b85aea0393 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -60,7 +60,7 @@ ifndef VERBOSE VERBOSE = 0 endif -INCLUDES = -I$(if $(OUTPUT),$(OUTPUT),.) \ +INCLUDES = -I$(or $(OUTPUT),.) \ -I$(srctree)/tools/include -I$(srctree)/tools/include/uapi export prefix libdir src obj diff --git a/tools/lib/perf/Makefile b/tools/lib/perf/Makefile index 08fe6e3c4089..21df023a2103 100644 --- a/tools/lib/perf/Makefile +++ b/tools/lib/perf/Makefile @@ -153,7 +153,7 @@ $(TESTS_STATIC): $(TESTS_IN) $(LIBPERF_A) $(LIBAPI) $(QUIET_LINK)$(CC) -o $@ $^ $(TESTS_SHARED): $(TESTS_IN) $(LIBAPI) - $(QUIET_LINK)$(CC) -o $@ -L$(if $(OUTPUT),$(OUTPUT),.) $^ -lperf + $(QUIET_LINK)$(CC) -o $@ -L$(or $(OUTPUT),.) $^ -lperf make-tests: libs $(TESTS_SHARED) $(TESTS_STATIC) diff --git a/tools/lib/subcmd/Makefile b/tools/lib/subcmd/Makefile index 1c777a72bb39..8f1a09cdfd17 100644 --- a/tools/lib/subcmd/Makefile +++ b/tools/lib/subcmd/Makefile @@ -63,7 +63,7 @@ $(LIBFILE): $(SUBCMD_IN) clean: $(call QUIET_CLEAN, libsubcmd) $(RM) $(LIBFILE); \ - find $(if $(OUTPUT),$(OUTPUT),.) -name \*.o -or -name \*.o.cmd -or -name \*.o.d | xargs $(RM) + find $(or $(OUTPUT),.) -name \*.o -or -name \*.o.cmd -or -name \*.o.d | xargs $(RM) FORCE: diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile index 92ce4fce7bc7..0dbd397f319d 100644 --- a/tools/objtool/Makefile +++ b/tools/objtool/Makefile @@ -13,7 +13,7 @@ srctree := $(patsubst %/,%,$(dir $(srctree))) endif SUBCMD_SRCDIR = $(srctree)/tools/lib/subcmd/ -LIBSUBCMD_OUTPUT = $(if $(OUTPUT),$(OUTPUT),$(CURDIR)/) +LIBSUBCMD_OUTPUT = $(or $(OUTPUT),$(CURDIR)/) LIBSUBCMD = $(LIBSUBCMD_OUTPUT)libsubcmd.a OBJTOOL := $(OUTPUT)objtool diff --git a/tools/pci/Makefile b/tools/pci/Makefile index 4b95a5176355..57744778b518 100644 --- a/tools/pci/Makefile +++ b/tools/pci/Makefile @@ -42,7 +42,7 @@ $(OUTPUT)pcitest: $(PCITEST_IN) clean: rm -f $(ALL_PROGRAMS) rm -rf $(OUTPUT)include/ - find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete + find $(or $(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete install: $(ALL_PROGRAMS) install -d -m 755 $(DESTDIR)$(bindir); \ diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index ac861e42c8f7..8583d18a3739 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -724,7 +724,7 @@ endif # get relative building directory (to $(OUTPUT)) # and '.' if it's $(OUTPUT) itself __build-dir = $(subst $(OUTPUT),,$(dir $@)) -build-dir = $(if $(__build-dir),$(__build-dir),.) +build-dir = $(or $(__build-dir),.) prepare: $(OUTPUT)PERF-VERSION-FILE $(OUTPUT)common-cmds.h archheaders $(drm_ioctl_array) \ $(fadvise_advice_array) \ @@ -1090,7 +1090,7 @@ bpf-skel-clean: clean:: $(LIBTRACEEVENT)-clean $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clean $(LIBPERF)-clean fixdep-clean python-clean bpf-skel-clean $(call QUIET_CLEAN, core-objs) $(RM) $(LIBPERF_A) $(OUTPUT)perf-archive $(OUTPUT)perf-with-kcore $(OUTPUT)perf-iostat $(LANG_BINDINGS) - $(Q)find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete + $(Q)find $(or $(OUTPUT),.) -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete $(Q)$(RM) $(OUTPUT).config-detected $(call QUIET_CLEAN, core-progs) $(RM) $(ALL_PROGRAMS) perf perf-read-vdso32 perf-read-vdsox32 $(OUTPUT)pmu-events/jevents $(OUTPUT)$(LIBJVMTI).so $(call QUIET_CLEAN, core-gen) $(RM) *.spec *.pyc *.pyo */*.pyc */*.pyo $(OUTPUT)common-cmds.h TAGS tags cscope* $(OUTPUT)PERF-VERSION-FILE $(OUTPUT)FEATURE-DUMP $(OUTPUT)util/*-bison* $(OUTPUT)util/*-flex* \ diff --git a/tools/power/x86/intel-speed-select/Makefile b/tools/power/x86/intel-speed-select/Makefile index 12c6939dca2a..7eaa517cd403 100644 --- a/tools/power/x86/intel-speed-select/Makefile +++ b/tools/power/x86/intel-speed-select/Makefile @@ -43,7 +43,7 @@ $(OUTPUT)intel-speed-select: $(ISST_IN) clean: rm -f $(ALL_PROGRAMS) rm -rf $(OUTPUT)include/linux/isst_if.h - find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete + find $(or $(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete install: $(ALL_PROGRAMS) install -d -m 755 $(DESTDIR)$(bindir); \ diff --git a/tools/scripts/utilities.mak b/tools/scripts/utilities.mak index c16ce833079c..172e47273b5d 100644 --- a/tools/scripts/utilities.mak +++ b/tools/scripts/utilities.mak @@ -175,5 +175,5 @@ _ge-abspath = $(if $(is-executable),$(1)) define get-executable-or-default $(if $($(1)),$(call _ge_attempt,$($(1)),$(1)),$(call _ge_attempt,$(2))) endef -_ge_attempt = $(if $(get-executable),$(get-executable),$(call _gea_err,$(2))) +_ge_attempt = $(or $(get-executable),$(call _gea_err,$(2))) _gea_err = $(if $(1),$(error Please set '$(1)' appropriately)) diff --git a/tools/spi/Makefile b/tools/spi/Makefile index 0aa6dbd31fb8..7fccd245a535 100644 --- a/tools/spi/Makefile +++ b/tools/spi/Makefile @@ -53,9 +53,9 @@ $(OUTPUT)spidev_fdx: $(SPIDEV_FDX_IN) clean: rm -f $(ALL_PROGRAMS) rm -rf $(OUTPUT)include/ - find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete - find $(if $(OUTPUT),$(OUTPUT),.) -name '\.*.o.d' -delete - find $(if $(OUTPUT),$(OUTPUT),.) -name '\.*.o.cmd' -delete + find $(or $(OUTPUT),.) -name '*.o' -delete + find $(or $(OUTPUT),.) -name '\.*.o.d' -delete + find $(or $(OUTPUT),.) -name '\.*.o.cmd' -delete install: $(ALL_PROGRAMS) install -d -m 755 $(DESTDIR)$(bindir); \ diff --git a/tools/tracing/rtla/Makefile b/tools/tracing/rtla/Makefile index 5a1eda617992..11fb417abb42 100644 --- a/tools/tracing/rtla/Makefile +++ b/tools/tracing/rtla/Makefile @@ -46,7 +46,7 @@ DATADIR := /usr/share DOCDIR := $(DATADIR)/doc MANDIR := $(DATADIR)/man LICDIR := $(DATADIR)/licenses -SRCTREE := $(if $(BUILD_SRC),$(BUILD_SRC),$(CURDIR)) +SRCTREE := $(or $(BUILD_SRC),$(CURDIR)) # If running from the tarball, man pages are stored in the Documentation # dir. If running from the kernel source, man pages are stored in diff --git a/tools/usb/Makefile b/tools/usb/Makefile index 1b128e551b2e..c6235667dd46 100644 --- a/tools/usb/Makefile +++ b/tools/usb/Makefile @@ -38,7 +38,7 @@ $(OUTPUT)ffs-test: $(FFS_TEST_IN) clean: rm -f $(ALL_PROGRAMS) - find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete -o -name '\.*.o.cmd' -delete + find $(or $(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete -o -name '\.*.o.cmd' -delete install: $(ALL_PROGRAMS) install -d -m 755 $(DESTDIR)$(bindir); \ -- cgit v1.2.3-58-ga151 From ffb217a13a2eaf6d5bd974fc83036a53ca69f1e2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 6 Mar 2022 14:28:31 -0800 Subject: Linux 5.17-rc7 --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index daeb5c88b50b..87f672473523 100644 --- a/Makefile +++ b/Makefile @@ -2,7 +2,7 @@ VERSION = 5 PATCHLEVEL = 17 SUBLEVEL = 0 -EXTRAVERSION = -rc6 +EXTRAVERSION = -rc7 NAME = Superb Owl # *DOCUMENTATION* -- cgit v1.2.3-58-ga151 From 4d94f910e79a349b00a4f8aab6f3ae87129d8c5a Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Tue, 8 Mar 2022 22:56:13 +0100 Subject: Kbuild: use -Wdeclaration-after-statement MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The kernel is moving from using `-std=gnu89` to `-std=gnu11`, permitting the use of additional C11 features such as for-loop initial declarations. One contentious aspect of C99 is that it permits mixed declarations and code, and for now at least, it seems preferable to enforce that declarations must come first. These warnings were already enabled in the kernel itself, but not for KBUILD_USERCFLAGS or the compat VDSO on arch/arm64, which uses a separate set of CFLAGS. This patch fixes an existing violation in modpost.c, which is not reported because of the missing flag in KBUILD_USERCFLAGS: | scripts/mod/modpost.c: In function ‘match’: | scripts/mod/modpost.c:837:3: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement] | 837 | const char *endp = p + strlen(p) - 1; | | ^~~~~ Signed-off-by: Mark Rutland [arnd: don't add a duplicate flag to the default set, update changelog] Signed-off-by: Arnd Bergmann Reviewed-by: Nathan Chancellor Reviewed-by: Nick Desaulniers Tested-by: Sedat Dilek # LLVM/Clang v13.0.0 (x86-64) Signed-off-by: Masahiro Yamada --- Makefile | 3 ++- arch/arm64/kernel/vdso32/Makefile | 1 + scripts/mod/modpost.c | 4 +++- 3 files changed, 6 insertions(+), 2 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 51e142f760f7..84a2de340934 100644 --- a/Makefile +++ b/Makefile @@ -432,7 +432,8 @@ HOSTCXX = g++ endif export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \ - -O2 -fomit-frame-pointer -std=gnu89 + -O2 -fomit-frame-pointer -std=gnu89 \ + -Wdeclaration-after-statement export KBUILD_USERLDFLAGS := KBUILD_HOSTCFLAGS := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS) diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile index 6c01b63ff56d..f46457f1f4f0 100644 --- a/arch/arm64/kernel/vdso32/Makefile +++ b/arch/arm64/kernel/vdso32/Makefile @@ -68,6 +68,7 @@ VDSO_CFLAGS += -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ -fno-strict-aliasing -fno-common \ -Werror-implicit-function-declaration \ -Wno-format-security \ + -Wdeclaration-after-statement \ -std=gnu89 VDSO_CFLAGS += -O2 # Some useful compiler-dependent flags from top-level Makefile diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 6bfa33217914..fe693304b120 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -833,8 +833,10 @@ static int match(const char *sym, const char * const pat[]) { const char *p; while (*pat) { + const char *endp; + p = *pat++; - const char *endp = p + strlen(p) - 1; + endp = p + strlen(p) - 1; /* "*foo*" */ if (*p == '*' && *endp == '*') { -- cgit v1.2.3-58-ga151 From e8c07082a810fbb9db303a2b66b66b8d7e588b53 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 8 Mar 2022 22:56:14 +0100 Subject: Kbuild: move to -std=gnu11 During a patch discussion, Linus brought up the option of changing the C standard version from gnu89 to gnu99, which allows using variable declaration inside of a for() loop. While the C99, C11 and later standards introduce many other features, most of these are already available in gnu89 as GNU extensions as well. An earlier attempt to do this when gcc-5 started defaulting to -std=gnu11 failed because at the time that caused warnings about designated initializers with older compilers. Now that gcc-5.1 is the minimum compiler version used for building kernels, that is no longer a concern. Similarly, the behavior of 'inline' functions changes between gnu89 using gnu_inline behavior and gnu11 using standard c99+ behavior, but this was taken care of by defining 'inline' to include __attribute__((gnu_inline)) in order to allow building with clang a while ago. Nathan Chancellor reported a new -Wdeclaration-after-statement warning that appears in a system header on arm, this still needs a workaround. The differences between gnu99, gnu11, gnu1x and gnu17 are fairly minimal and mainly impact warnings at the -Wpedantic level that the kernel never enables. Between these, gnu11 is the newest version that is supported by all supported compiler versions, though it is only the default on gcc-5, while all other supported versions of gcc or clang default to gnu1x/gnu17. Link: https://lore.kernel.org/lkml/CAHk-=wiyCH7xeHcmiFJ-YgXUy2Jaj7pnkdKpcovt8fYbVFW3TA@mail.gmail.com/ Link: https://github.com/ClangBuiltLinux/linux/issues/1603 Suggested-by: Linus Torvalds Acked-by: Marco Elver Acked-by: Jani Nikula Acked-by: David Sterba Tested-by: Sedat Dilek Reviewed-by: Alex Shi Reviewed-by: Nick Desaulniers Reviewed-by: Miguel Ojeda Signed-off-by: Arnd Bergmann Reviewed-by: Nathan Chancellor Signed-off-by: Masahiro Yamada --- Documentation/process/programming-language.rst | 6 +++--- Documentation/translations/it_IT/process/programming-language.rst | 4 ++-- Documentation/translations/zh_CN/process/programming-language.rst | 3 +-- Documentation/translations/zh_TW/process/programming-language.rst | 3 +-- Makefile | 4 ++-- arch/arm64/kernel/vdso32/Makefile | 2 +- 6 files changed, 10 insertions(+), 12 deletions(-) (limited to 'Makefile') diff --git a/Documentation/process/programming-language.rst b/Documentation/process/programming-language.rst index ec474a70a02f..5fc9160ca1fa 100644 --- a/Documentation/process/programming-language.rst +++ b/Documentation/process/programming-language.rst @@ -5,9 +5,9 @@ Programming Language The kernel is written in the C programming language [c-language]_. More precisely, the kernel is typically compiled with ``gcc`` [gcc]_ -under ``-std=gnu89`` [gcc-c-dialect-options]_: the GNU dialect of ISO C90 -(including some C99 features). ``clang`` [clang]_ is also supported, see -docs on :ref:`Building Linux with Clang/LLVM `. +under ``-std=gnu11`` [gcc-c-dialect-options]_: the GNU dialect of ISO C11. +``clang`` [clang]_ is also supported, see docs on +:ref:`Building Linux with Clang/LLVM `. This dialect contains many extensions to the language [gnu-extensions]_, and many of them are used within the kernel as a matter of course. diff --git a/Documentation/translations/it_IT/process/programming-language.rst b/Documentation/translations/it_IT/process/programming-language.rst index 41db2598ce11..c1a9b481a6f9 100644 --- a/Documentation/translations/it_IT/process/programming-language.rst +++ b/Documentation/translations/it_IT/process/programming-language.rst @@ -10,8 +10,8 @@ Linguaggio di programmazione Il kernel è scritto nel linguaggio di programmazione C [it-c-language]_. Più precisamente, il kernel viene compilato con ``gcc`` [it-gcc]_ usando -l'opzione ``-std=gnu89`` [it-gcc-c-dialect-options]_: il dialetto GNU -dello standard ISO C90 (con l'aggiunta di alcune funzionalità da C99). +l'opzione ``-std=gnu11`` [it-gcc-c-dialect-options]_: il dialetto GNU +dello standard ISO C11. Linux supporta anche ``clang`` [it-clang]_, leggete la documentazione :ref:`Building Linux with Clang/LLVM `. diff --git a/Documentation/translations/zh_CN/process/programming-language.rst b/Documentation/translations/zh_CN/process/programming-language.rst index 2a47a1d2ec20..fabdc338dbfb 100644 --- a/Documentation/translations/zh_CN/process/programming-language.rst +++ b/Documentation/translations/zh_CN/process/programming-language.rst @@ -9,8 +9,7 @@ ============ 内核是用C语言 :ref:`c-language ` 编写的。更准确地说，内核通常是用 :ref:`gcc ` -在 ``-std=gnu89`` :ref:`gcc-c-dialect-options ` 下编译的：ISO C90的 GNU 方言（ -包括一些C99特性） +在 ``-std=gnu11`` :ref:`gcc-c-dialect-options ` 下编译的：ISO C11的 GNU 方言 这种方言包含对语言 :ref:`gnu-extensions ` 的许多扩展，当然，它们许多都在内核中使用。 diff --git a/Documentation/translations/zh_TW/process/programming-language.rst b/Documentation/translations/zh_TW/process/programming-language.rst index 54e3699eadf8..144bdaf81a41 100644 --- a/Documentation/translations/zh_TW/process/programming-language.rst +++ b/Documentation/translations/zh_TW/process/programming-language.rst @@ -12,8 +12,7 @@ ============ 內核是用C語言 :ref:`c-language ` 編寫的。更準確地說，內核通常是用 :ref:`gcc ` -在 ``-std=gnu89`` :ref:`gcc-c-dialect-options ` 下編譯的：ISO C90的 GNU 方言（ -包括一些C99特性） +在 ``-std=gnu11`` :ref:`gcc-c-dialect-options ` 下編譯的：ISO C11的 GNU 方言 這種方言包含對語言 :ref:`gnu-extensions ` 的許多擴展，當然，它們許多都在內核中使用。 diff --git a/Makefile b/Makefile index 84a2de340934..19b4f75d42c2 100644 --- a/Makefile +++ b/Makefile @@ -516,7 +516,7 @@ KBUILD_CFLAGS := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \ -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \ -Werror=implicit-function-declaration -Werror=implicit-int \ -Werror=return-type -Wno-format-security \ - -std=gnu89 + -std=gnu11 KBUILD_CPPFLAGS := -D__KERNEL__ KBUILD_AFLAGS_KERNEL := KBUILD_CFLAGS_KERNEL := @@ -783,7 +783,7 @@ KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH) ifdef CONFIG_CC_IS_CLANG KBUILD_CPPFLAGS += -Qunused-arguments -# The kernel builds with '-std=gnu89' so use of GNU extensions is acceptable. +# The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable. KBUILD_CFLAGS += -Wno-gnu # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the # source of a reference will be _MergedGlobals and not on of the whitelisted names. diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile index f46457f1f4f0..ed181bedbffc 100644 --- a/arch/arm64/kernel/vdso32/Makefile +++ b/arch/arm64/kernel/vdso32/Makefile @@ -69,7 +69,7 @@ VDSO_CFLAGS += -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ -Werror-implicit-function-declaration \ -Wno-format-security \ -Wdeclaration-after-statement \ - -std=gnu89 + -std=gnu11 VDSO_CFLAGS += -O2 # Some useful compiler-dependent flags from top-level Makefile VDSO_CFLAGS += $(call cc32-option,-Wdeclaration-after-statement,) -- cgit v1.2.3-58-ga151 From 1e24078113ae69c741cb1b03375a9f1490db7308 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 8 Mar 2022 22:56:15 +0100 Subject: Kbuild: use -std=gnu11 for KBUILD_USERCFLAGS As we change the C language standard for the kernel from gnu89 to gnu11, it makes sense to also update the version for user space compilation. Some users have older native compilers than what they use for kernel builds, so I considered using gnu99 as the default version for wider compatibility with gcc-4.6 and earlier. However, testing with older compilers showed that we already require HOSTCC version 5.1 as well because a lot of host tools include linux/compiler.h that uses __has_attribute(): CC tools/objtool/exec-cmd.o In file included from tools/include/linux/compiler_types.h:36:0, from tools/include/linux/compiler.h:5, from exec-cmd.c:2: tools/include/linux/compiler-gcc.h:19:5: error: "__has_attribute" is not defined [-Werror=undef] Signed-off-by: Arnd Bergmann Reviewed-by: Nathan Chancellor Reviewed-by: Nick Desaulniers Tested-by: Sedat Dilek Signed-off-by: Masahiro Yamada --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 19b4f75d42c2..8a18fa1e19a7 100644 --- a/Makefile +++ b/Makefile @@ -432,7 +432,7 @@ HOSTCXX = g++ endif export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \ - -O2 -fomit-frame-pointer -std=gnu89 \ + -O2 -fomit-frame-pointer -std=gnu11 \ -Wdeclaration-after-statement export KBUILD_USERLDFLAGS := -- cgit v1.2.3-58-ga151 From 09688c0166e76ce2fb85e86b9d99be8b0084cdf9 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 13 Mar 2022 13:23:37 -0700 Subject: Linux 5.17-rc8 --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 87f672473523..55a30ca69350 100644 --- a/Makefile +++ b/Makefile @@ -2,7 +2,7 @@ VERSION = 5 PATCHLEVEL = 17 SUBLEVEL = 0 -EXTRAVERSION = -rc7 +EXTRAVERSION = -rc8 NAME = Superb Owl # *DOCUMENTATION* -- cgit v1.2.3-58-ga151 From f443e374ae131c168a065ea1748feac6b2e76613 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 20 Mar 2022 13:14:17 -0700 Subject: Linux 5.17 Signed-off-by: Linus Torvalds --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 55a30ca69350..7214f075e1f0 100644 --- a/Makefile +++ b/Makefile @@ -2,7 +2,7 @@ VERSION = 5 PATCHLEVEL = 17 SUBLEVEL = 0 -EXTRAVERSION = -rc8 +EXTRAVERSION = NAME = Superb Owl # *DOCUMENTATION* -- cgit v1.2.3-58-ga151 From e9c281928c24dfeb86b11c31b53757b6a127f8aa Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Fri, 4 Mar 2022 10:08:14 -0700 Subject: kbuild: Make $(LLVM) more flexible The LLVM make variable allows a developer to quickly switch between the GNU and LLVM tools. However, it does not handle versioned binaries, such as the ones shipped by Debian, as LLVM=1 just defines the tool variables with the unversioned binaries. There was some discussion during the review of the patch that introduces LLVM=1 around versioned binaries, ultimately coming to the conclusion that developers can just add the folder that contains the unversioned binaries to their PATH, as Debian's versioned suffixed binaries are really just symlinks to the unversioned binaries in /usr/lib/llvm-#/bin: $ realpath /usr/bin/clang-14 /usr/lib/llvm-14/bin/clang $ PATH=/usr/lib/llvm-14/bin:$PATH make ... LLVM=1 However, that can be cumbersome to developers who are constantly testing series with different toolchains and versions. It is simple enough to support these versioned binaries directly in the Kbuild system by allowing the developer to specify the version suffix with LLVM=, which is shorter than the above suggestion: $ make ... LLVM=-14 It does not change the meaning of LLVM=1 (which will continue to use unversioned binaries) and it does not add too much additional complexity to the existing $(LLVM) code, while allowing developers to quickly test their series with different versions of the whole LLVM suite of tools. Some developers may build LLVM from source but not add the binaries to their PATH, as they may not want to use that toolchain systemwide. Support those developers by allowing them to supply the directory that the LLVM tools are available in, as it is no more complex to support than the version suffix change above. $ make ... LLVM=/path/to/llvm/ Update and reorder the documentation to reflect these new additions. At the same time, notate that LLVM=0 is not the same as just omitting it altogether, which has confused people in the past. Link: https://lore.kernel.org/r/20200317215515.226917-1-ndesaulniers@google.com/ Link: https://lore.kernel.org/r/20220224151322.072632223@infradead.org/ Suggested-by: Masahiro Yamada Suggested-by: Peter Zijlstra Signed-off-by: Nathan Chancellor Reviewed-by: Kees Cook Reviewed-by: Nick Desaulniers Signed-off-by: Masahiro Yamada --- Documentation/kbuild/llvm.rst | 31 +++++++++++++++++++++++++------ Makefile | 26 ++++++++++++++++---------- tools/scripts/Makefile.include | 22 ++++++++++++++-------- tools/testing/selftests/lib.mk | 8 +++++++- 4 files changed, 62 insertions(+), 25 deletions(-) (limited to 'Makefile') diff --git a/Documentation/kbuild/llvm.rst b/Documentation/kbuild/llvm.rst index d32616891dcf..b854bb413164 100644 --- a/Documentation/kbuild/llvm.rst +++ b/Documentation/kbuild/llvm.rst @@ -49,17 +49,36 @@ example: :: LLVM Utilities -------------- -LLVM has substitutes for GNU binutils utilities. Kbuild supports ``LLVM=1`` -to enable them. :: - - make LLVM=1 - -They can be enabled individually. The full list of the parameters: :: +LLVM has substitutes for GNU binutils utilities. They can be enabled individually. +The full list of supported make variables:: make CC=clang LD=ld.lld AR=llvm-ar NM=llvm-nm STRIP=llvm-strip \ OBJCOPY=llvm-objcopy OBJDUMP=llvm-objdump READELF=llvm-readelf \ HOSTCC=clang HOSTCXX=clang++ HOSTAR=llvm-ar HOSTLD=ld.lld +To simplify the above command, Kbuild supports the ``LLVM`` variable:: + + make LLVM=1 + +If your LLVM tools are not available in your PATH, you can supply their +location using the LLVM variable with a trailing slash:: + + make LLVM=/path/to/llvm/ + +which will use ``/path/to/llvm/clang``, ``/path/to/llvm/ld.lld``, etc. + +If your LLVM tools have a version suffix and you want to test with that +explicit version rather than the unsuffixed executables like ``LLVM=1``, you +can pass the suffix using the ``LLVM`` variable:: + + make LLVM=-14 + +which will use ``clang-14``, ``ld.lld-14``, etc. + +``LLVM=0`` is not the same as omitting ``LLVM`` altogether, it will behave like +``LLVM=1``. If you only wish to use certain LLVM utilities, use their respective +make variables. + The integrated assembler is enabled by default. You can pass ``LLVM_IAS=0`` to disable it. diff --git a/Makefile b/Makefile index a82095c69fdd..b3fb32fd3906 100644 --- a/Makefile +++ b/Makefile @@ -424,8 +424,14 @@ HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null) HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null) ifneq ($(LLVM),) -HOSTCC = clang -HOSTCXX = clang++ +ifneq ($(filter %/,$(LLVM)),) +LLVM_PREFIX := $(LLVM) +else ifneq ($(filter -%,$(LLVM)),) +LLVM_SUFFIX := $(LLVM) +endif + +HOSTCC = $(LLVM_PREFIX)clang$(LLVM_SUFFIX) +HOSTCXX = $(LLVM_PREFIX)clang++$(LLVM_SUFFIX) else HOSTCC = gcc HOSTCXX = g++ @@ -444,14 +450,14 @@ KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS) # Make variables (CC, etc...) CPP = $(CC) -E ifneq ($(LLVM),) -CC = clang -LD = ld.lld -AR = llvm-ar -NM = llvm-nm -OBJCOPY = llvm-objcopy -OBJDUMP = llvm-objdump -READELF = llvm-readelf -STRIP = llvm-strip +CC = $(LLVM_PREFIX)clang$(LLVM_SUFFIX) +LD = $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX) +AR = $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX) +NM = $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX) +OBJCOPY = $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX) +OBJDUMP = $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX) +READELF = $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX) +STRIP = $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX) else CC = $(CROSS_COMPILE)gcc LD = $(CROSS_COMPILE)ld diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include index 79d102304470..b507a6a733f5 100644 --- a/tools/scripts/Makefile.include +++ b/tools/scripts/Makefile.include @@ -52,11 +52,17 @@ define allow-override endef ifneq ($(LLVM),) -$(call allow-override,CC,clang) -$(call allow-override,AR,llvm-ar) -$(call allow-override,LD,ld.lld) -$(call allow-override,CXX,clang++) -$(call allow-override,STRIP,llvm-strip) +ifneq ($(filter %/,$(LLVM)),) +LLVM_PREFIX := $(LLVM) +else ifneq ($(filter -%,$(LLVM)),) +LLVM_SUFFIX := $(LLVM) +endif + +$(call allow-override,CC,$(LLVM_PREFIX)clang$(LLVM_SUFFIX)) +$(call allow-override,AR,$(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)) +$(call allow-override,LD,$(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)) +$(call allow-override,CXX,$(LLVM_PREFIX)clang++$(LLVM_SUFFIX)) +$(call allow-override,STRIP,$(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)) else # Allow setting various cross-compile vars or setting CROSS_COMPILE as a prefix. $(call allow-override,CC,$(CROSS_COMPILE)gcc) @@ -69,9 +75,9 @@ endif CC_NO_CLANG := $(shell $(CC) -dM -E -x c /dev/null | grep -Fq "__clang__"; echo $$?) ifneq ($(LLVM),) -HOSTAR ?= llvm-ar -HOSTCC ?= clang -HOSTLD ?= ld.lld +HOSTAR ?= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX) +HOSTCC ?= $(LLVM_PREFIX)clang$(LLVM_SUFFIX) +HOSTLD ?= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX) else HOSTAR ?= ar HOSTCC ?= gcc diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk index a40add31a2e3..2a2d240cdc1b 100644 --- a/tools/testing/selftests/lib.mk +++ b/tools/testing/selftests/lib.mk @@ -1,7 +1,13 @@ # This mimics the top-level Makefile. We do it explicitly here so that this # Makefile can operate with or without the kbuild infrastructure. ifneq ($(LLVM),) -CC := clang +ifneq ($(filter %/,$(LLVM)),) +LLVM_PREFIX := $(LLVM) +else ifneq ($(filter -%,$(LLVM)),) +LLVM_SUFFIX := $(LLVM) +endif + +CC := $(LLVM_PREFIX)clang$(LLVM_SUFFIX) else CC := $(CROSS_COMPILE)gcc endif -- cgit v1.2.3-58-ga151 From cf300b83c793c25c6b485fdaf7a4447d8ea4c655 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Wed, 30 Mar 2022 16:45:27 -0700 Subject: kbuild: Remove '-mno-global-merge' This flag is specific to clang, where it is only used by the 32-bit and 64-bit ARM backends. In certain situations, the presence of this flag will cause a warning, as shown by commit 6580c5c18fb3 ("um: clang: Strip out -mno-global-merge from USER_CFLAGS"). Since commit 61163efae020 ("kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang") that added this flag back in 2014, there have been quite a few changes to the GlobalMerge pass in LLVM. Building several different ARCH=arm and ARCH=arm64 configurations with LLVM 11 (minimum) and 15 (current main version) with this flag removed (i.e., with the default of '-mglobal-merge') reveals no modpost warnings, so it is likely that the issue noted in the comment is no longer relevant due to changes in LLVM or modpost, meaning this flag can be removed. If any new warnings show up that are a result of the removal of this flag, it can be added back under arch/arm{,64}/Makefile to avoid warnings on other architectures. Signed-off-by: Nathan Chancellor Tested-by: David Gow Reviewed-by: Kees Cook Tested-by: Sedat Dilek Reviewed-by: Sedat Dilek Signed-off-by: Masahiro Yamada --- Makefile | 4 ---- 1 file changed, 4 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 18ecb49f1af6..3b3cd75bba87 100644 --- a/Makefile +++ b/Makefile @@ -793,10 +793,6 @@ ifdef CONFIG_CC_IS_CLANG KBUILD_CPPFLAGS += -Qunused-arguments # The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable. KBUILD_CFLAGS += -Wno-gnu -# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the -# source of a reference will be _MergedGlobals and not on of the whitelisted names. -# See modpost pattern 2 -KBUILD_CFLAGS += -mno-global-merge else # gcc inanely warns about local variables called 'main' -- cgit v1.2.3-58-ga151 From 3123109284176b1532874591f7c81f3837bbdc17 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 3 Apr 2022 14:08:21 -0700 Subject: Linux 5.18-rc1 --- Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 3b3cd75bba87..8c7de9a72ea2 100644 --- a/Makefile +++ b/Makefile @@ -1,8 +1,8 @@ # SPDX-License-Identifier: GPL-2.0 VERSION = 5 -PATCHLEVEL = 17 +PATCHLEVEL = 18 SUBLEVEL = 0 -EXTRAVERSION = +EXTRAVERSION = -rc1 NAME = Superb Owl # *DOCUMENTATION* -- cgit v1.2.3-58-ga151