Commit b250e6d1 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Add -s option (strict mode) to merge_config.sh to make it fail when
   any symbol is redefined.

 - Show a warning if a different compiler is used for building external
   modules.

 - Infer --target from ARCH for CC=clang to let you cross-compile the
   kernel without CROSS_COMPILE.

 - Make the integrated assembler default (LLVM_IAS=1) for CC=clang.

 - Add <linux/stdarg.h> to the kernel source instead of borrowing
   <stdarg.h> from the compiler.

 - Add Nick Desaulniers as a Kbuild reviewer.

 - Drop stale cc-option tests.

 - Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG
   to handle symbols in inline assembly.

 - Show a warning if 'FORCE' is missing for if_changed rules.

 - Various cleanups

* tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits)
  kbuild: redo fake deps at include/ksym/*.h
  kbuild: clean up objtool_args slightly
  modpost: get the *.mod file path more simply
  checkkconfigsymbols.py: Fix the '--ignore' option
  kbuild: merge vmlinux_link() between ARCH=um and other architectures
  kbuild: do not remove 'linux' link in scripts/link-vmlinux.sh
  kbuild: merge vmlinux_link() between the ordinary link and Clang LTO
  kbuild: remove stale *.symversions
  kbuild: remove unused quiet_cmd_update_lto_symversions
  gen_compile_commands: extract compiler command from a series of commands
  x86: remove cc-option-yn test for -mtune=
  arc: replace cc-option-yn uses with cc-option
  s390: replace cc-option-yn uses with cc-option
  ia64: move core-y in arch/ia64/Makefile to arch/ia64/Kbuild
  sparc: move the install rule to arch/sparc/Makefile
  security: remove unneeded subdir-$(CONFIG_...)
  kbuild: sh: remove unused install script
  kbuild: Fix 'no symbols' warning when CONFIG_TRIM_UNUSD_KSYMS=y
  kbuild: Switch to 'f' variants of integrated assembler flag
  kbuild: Shuffle blank line to improve comment meaning
  ...
parents 4e71add0 bc7cd2dd
......@@ -38,7 +38,7 @@ Cross Compiling
A single Clang compiler binary will typically contain all supported backends,
which can help simplify cross compiling. ::
ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- make CC=clang
make ARCH=arm64 CC=clang CROSS_COMPILE=aarch64-linux-gnu-
``CROSS_COMPILE`` is not used to prefix the Clang compiler binary, instead
``CROSS_COMPILE`` is used to set a command line flag: ``--target=<triple>``. For
......@@ -60,8 +60,27 @@ They can be enabled individually. The full list of the parameters: ::
OBJCOPY=llvm-objcopy OBJDUMP=llvm-objdump READELF=llvm-readelf \
HOSTCC=clang HOSTCXX=clang++ HOSTAR=llvm-ar HOSTLD=ld.lld
Currently, the integrated assembler is disabled by default. You can pass
``LLVM_IAS=1`` to enable it.
The integrated assembler is enabled by default. You can pass ``LLVM_IAS=0`` to
disable it.
Omitting CROSS_COMPILE
----------------------
As explained above, ``CROSS_COMPILE`` is used to set ``--target=<triple>``.
If ``CROSS_COMPILE`` is not specified, the ``--target=<triple>`` is inferred
from ``ARCH``.
That means if you use only LLVM tools, ``CROSS_COMPILE`` becomes unnecessary.
For example, to cross-compile the arm64 kernel::
make ARCH=arm64 LLVM=1
If ``LLVM_IAS=0`` is specified, ``CROSS_COMPILE`` is also used to derive
``--prefix=<path>`` to search for the GNU assembler and linker. ::
make ARCH=arm64 LLVM=1 LLVM_IAS=0 CROSS_COMPILE=aarch64-linux-gnu-
Supported Architectures
-----------------------
......
......@@ -4532,6 +4532,7 @@ B: https://github.com/ClangBuiltLinux/linux/issues
C: irc://irc.libera.chat/clangbuiltlinux
F: Documentation/kbuild/llvm.rst
F: include/linux/compiler-clang.h
F: scripts/Makefile.clang
F: scripts/clang-tools/
K: \b(?i:clang|llvm)\b
 
......@@ -10116,6 +10117,7 @@ F: fs/autofs/
KERNEL BUILD + files below scripts/ (unless maintained elsewhere)
M: Masahiro Yamada <masahiroy@kernel.org>
M: Michal Marek <michal.lkml@markovi.net>
R: Nick Desaulniers <ndesaulniers@google.com>
L: linux-kbuild@vger.kernel.org
S: Maintained
T: git git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git
......
......@@ -191,10 +191,9 @@ endif
ifneq ($(abs_srctree),$(abs_objtree))
# Look for make include files relative to root of kernel src
#
# This does not become effective immediately because MAKEFLAGS is re-parsed
# once after the Makefile is read. We need to invoke sub-make.
# --included-dir is added for backward compatibility, but you should not rely on
# it. Please add $(srctree)/ prefix to include Makefiles in the source tree.
MAKEFLAGS += --include-dir=$(abs_srctree)
need-sub-make := 1
endif
ifneq ($(filter 3.%,$(MAKE_VERSION)),)
......@@ -587,23 +586,10 @@ endif
# 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 = $(subst $(pound),,$(shell $(CC) --version 2>/dev/null | head -n 1))
CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
ifneq ($(CROSS_COMPILE),)
CLANG_FLAGS += --target=$(notdir $(CROSS_COMPILE:%-=%))
endif
ifeq ($(LLVM_IAS),1)
CLANG_FLAGS += -integrated-as
else
CLANG_FLAGS += -no-integrated-as
GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
endif
CLANG_FLAGS += -Werror=unknown-warning-option
KBUILD_CFLAGS += $(CLANG_FLAGS)
KBUILD_AFLAGS += $(CLANG_FLAGS)
export CLANG_FLAGS
include $(srctree)/scripts/Makefile.clang
endif
# Include this also for config targets because some architectures need
......@@ -688,9 +674,10 @@ endif # KBUILD_EXTMOD
# 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,)
CFLAGS_GCOV := -fprofile-arcs -ftest-coverage
ifdef CONFIG_CC_IS_GCC
CFLAGS_GCOV += -fno-tree-loop-im
endif
export CFLAGS_GCOV
# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
......@@ -698,12 +685,14 @@ ifdef CONFIG_FUNCTION_TRACER
CC_FLAGS_FTRACE := -pg
endif
RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
ifdef CONFIG_CC_IS_GCC
RETPOLINE_CFLAGS := $(call cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register)
RETPOLINE_VDSO_CFLAGS := $(call cc-option,-mindirect-branch=thunk-inline -mindirect-branch-register)
endif
ifdef CONFIG_CC_IS_CLANG
RETPOLINE_CFLAGS := -mretpoline-external-thunk
RETPOLINE_VDSO_CFLAGS := -mretpoline
endif
export RETPOLINE_CFLAGS
export RETPOLINE_VDSO_CFLAGS
......@@ -756,7 +745,7 @@ include/config/auto.conf:
endif # may-sync-config
endif # need-config
KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
KBUILD_CFLAGS += -fno-delete-null-pointer-checks
KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
......@@ -771,17 +760,19 @@ KBUILD_CFLAGS += -Os
endif
# Tell gcc to never replace conditional load with a non-conditional one
ifdef CONFIG_CC_IS_GCC
# gcc-10 renamed --param=allow-store-data-races=0 to
# -fno-allow-store-data-races.
KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
KBUILD_CFLAGS += $(call cc-option,-fno-allow-store-data-races)
endif
ifdef CONFIG_READABLE_ASM
# Disable optimizations that make assembler listings hard to read.
# reorder blocks reorders the control in the function
# ipa clone creates specialized cloned functions
# partial inlining inlines only parts of functions
KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
$(call cc-option,-fno-ipa-cp-clone,) \
$(call cc-option,-fno-partial-inlining)
KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
endif
ifneq ($(CONFIG_FRAME_WARN),0)
......@@ -796,7 +787,7 @@ KBUILD_CFLAGS += $(stackp-flags-y)
ifdef CONFIG_CC_IS_CLANG
KBUILD_CPPFLAGS += -Qunused-arguments
KBUILD_CFLAGS += -Wno-format-invalid-specifier
# The kernel builds with '-std=gnu89' 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.
......@@ -813,8 +804,8 @@ endif
# These warnings generated too much noise in a regular build.
# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
ifdef CONFIG_FRAME_POINTER
KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
else
......@@ -867,7 +858,7 @@ else
DEBUG_CFLAGS += -g
endif
ifneq ($(LLVM_IAS),1)
ifndef CONFIG_AS_IS_LLVM
KBUILD_AFLAGS += -Wa,-gdwarf-2
endif
......@@ -878,8 +869,10 @@ DEBUG_CFLAGS += -gdwarf-$(dwarf-version-y)
endif
ifdef CONFIG_DEBUG_INFO_REDUCED
DEBUG_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
$(call cc-option,-fno-var-tracking)
DEBUG_CFLAGS += -fno-var-tracking
ifdef CONFIG_CC_IS_GCC
DEBUG_CFLAGS += -femit-struct-debug-baseonly
endif
endif
ifdef CONFIG_DEBUG_INFO_COMPRESSED
......@@ -913,6 +906,7 @@ ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
endif
endif
ifdef CONFIG_HAVE_FENTRY
# s390-linux-gnu-gcc did not support -mfentry until gcc-9.
ifeq ($(call cc-option-yn, -mfentry),y)
CC_FLAGS_FTRACE += -mfentry
CC_FLAGS_USING += -DCC_USING_FENTRY
......@@ -925,7 +919,7 @@ endif
# We trigger additional mismatches with less inlining
ifdef CONFIG_DEBUG_SECTION_MISMATCH
KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
KBUILD_CFLAGS += -fno-inline-functions-called-once
endif
ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
......@@ -1004,14 +998,16 @@ 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, array-bounds)
KBUILD_CFLAGS += -Wno-array-bounds
KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
# Another good warning that we'll want to enable eventually
KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
# Enabled with W=2, disabled by default as noisy
KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized)
ifdef CONFIG_CC_IS_GCC
KBUILD_CFLAGS += -Wno-maybe-uninitialized
endif
# disable invalid "can't wrap" optimizations for signed / pointers
KBUILD_CFLAGS += -fno-strict-overflow
......@@ -1020,7 +1016,9 @@ KBUILD_CFLAGS += -fno-strict-overflow
KBUILD_CFLAGS += -fno-stack-check
# conserve stack if available
KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
ifdef CONFIG_CC_IS_GCC
KBUILD_CFLAGS += -fconserve-stack
endif
# Prohibit date/time macros, which would make the build non-deterministic
KBUILD_CFLAGS += -Werror=date-time
......@@ -1750,6 +1748,16 @@ clean-dirs := $(KBUILD_EXTMOD)
clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
$(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
PHONY += prepare
# now expand this into a simple variable to reduce the cost of shell evaluations
prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
prepare:
@if [ "$(CC_VERSION_TEXT)" != $(CONFIG_CC_VERSION_TEXT) ]; then \
echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
echo >&2 " The kernel was built by: "$(CONFIG_CC_VERSION_TEXT); \
echo >&2 " You are using: $(CC_VERSION_TEXT)"; \
fi
PHONY += help
help:
@echo ' Building external modules.'
......@@ -1761,7 +1769,7 @@ help:
@echo ''
# no-op for external module builds
PHONY += prepare modules_prepare
PHONY += modules_prepare
endif # KBUILD_EXTMOD
......
......@@ -18,8 +18,7 @@ ifeq ($(CONFIG_ARC_TUNE_MCPU),"")
cflags-y += $(tune-mcpu-def-y)
else
tune-mcpu := $(shell echo $(CONFIG_ARC_TUNE_MCPU))
tune-mcpu-ok := $(call cc-option-yn, $(tune-mcpu))
ifeq ($(tune-mcpu-ok),y)
ifneq ($(call cc-option,$(tune-mcpu)),)
cflags-y += $(tune-mcpu)
else
# The flag provided by 'CONFIG_ARC_TUNE_MCPU' option isn't known by this compiler
......
......@@ -5,8 +5,6 @@
* Copyright (C) 1996-2000 Russell King - Converted to ARM.
* Original Copyright (C) 1995 Linus Torvalds
*/
#include <stdarg.h>
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
......
......@@ -10,8 +10,6 @@
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <stdarg.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <linux/ioport.h>
......
......@@ -6,9 +6,6 @@
* Copyright (C) 1996-2000 Russell King - Converted to ARM.
* Copyright (C) 2012 ARM Ltd.
*/
#include <stdarg.h>
#include <linux/compat.h>
#include <linux/efi.h>
#include <linux/elf.h>
......
# SPDX-License-Identifier: GPL-2.0-only
obj-y += kernel/ mm/
obj-$(CONFIG_IA64_SGI_UV) += uv/
......@@ -47,8 +47,6 @@ KBUILD_CFLAGS += $(cflags-y)
head-y := arch/ia64/kernel/head.o
libs-y += arch/ia64/lib/
core-y += arch/ia64/kernel/ arch/ia64/mm/
core-$(CONFIG_IA64_SGI_UV) += arch/ia64/uv/
drivers-y += arch/ia64/pci/ arch/ia64/hp/common/
......
......@@ -254,7 +254,7 @@ endif
#
# Board-dependent options and extra files
#
include arch/mips/Kbuild.platforms
include $(srctree)/arch/mips/Kbuild.platforms
ifdef CONFIG_PHYSICAL_START
load-y = $(CONFIG_PHYSICAL_START)
......
......@@ -14,8 +14,6 @@
*/
#define __KERNEL_SYSCALLS__
#include <stdarg.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
......
......@@ -51,7 +51,7 @@
* prumpf 991016
*/
#include <stdarg.h>
#include <linux/stdarg.h>
#include <linux/delay.h>
#include <linux/init.h>
......
......@@ -17,9 +17,6 @@
* Copyright (C) 2001-2014 Helge Deller <deller@gmx.de>
* Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
*/
#include <stdarg.h>
#include <linux/elf.h>
#include <linux/errno.h>
#include <linux/kernel.h>
......
......@@ -11,7 +11,6 @@
#undef DEBUG
#include <stdarg.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/init.h>
......
......@@ -14,7 +14,7 @@
/* we cannot use FORTIFY as it brings in new symbols */
#define __NO_FORTIFY
#include <stdarg.h>
#include <linux/stdarg.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/init.h>
......
......@@ -7,7 +7,7 @@
* Copyright (C) 2001 IBM.
*/
#include <stdarg.h>
#include <linux/stdarg.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/spinlock.h>
......
......@@ -5,7 +5,7 @@
* c 2001 PPC 64 Team, IBM Corp
*/
#include <stdarg.h>
#include <linux/stdarg.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/console.h>
......
......@@ -41,7 +41,7 @@ endif
ifeq ($(CONFIG_LD_IS_LLD),y)
KBUILD_CFLAGS += -mno-relax
KBUILD_AFLAGS += -mno-relax
ifneq ($(LLVM_IAS),1)
ifndef CONFIG_AS_IS_LLVM
KBUILD_CFLAGS += -Wa,-mno-relax
KBUILD_AFLAGS += -Wa,-mno-relax
endif
......
......@@ -70,7 +70,7 @@ cflags-y += -Wa,-I$(srctree)/arch/$(ARCH)/include
#
cflags-$(CONFIG_FRAME_POINTER) += -fno-optimize-sibling-calls
ifeq ($(call cc-option-yn,-mpacked-stack -mbackchain -msoft-float),y)
ifneq ($(call cc-option,-mpacked-stack -mbackchain -msoft-float),)
cflags-$(CONFIG_PACK_STACK) += -mpacked-stack -D__PACK_STACK
aflags-$(CONFIG_PACK_STACK) += -D__PACK_STACK
endif
......@@ -78,22 +78,22 @@ endif
KBUILD_AFLAGS_DECOMPRESSOR += $(aflags-y)
KBUILD_CFLAGS_DECOMPRESSOR += $(cflags-y)
ifeq ($(call cc-option-yn,-mstack-size=8192 -mstack-guard=128),y)
ifneq ($(call cc-option,-mstack-size=8192 -mstack-guard=128),)
cflags-$(CONFIG_CHECK_STACK) += -mstack-size=$(STACK_SIZE)
ifneq ($(call cc-option-yn,-mstack-size=8192),y)
ifeq ($(call cc-option,-mstack-size=8192),)
cflags-$(CONFIG_CHECK_STACK) += -mstack-guard=$(CONFIG_STACK_GUARD)
endif
endif
ifdef CONFIG_WARN_DYNAMIC_STACK
ifeq ($(call cc-option-yn,-mwarn-dynamicstack),y)
ifneq ($(call cc-option,-mwarn-dynamicstack),)
KBUILD_CFLAGS += -mwarn-dynamicstack
KBUILD_CFLAGS_DECOMPRESSOR += -mwarn-dynamicstack
endif
endif
ifdef CONFIG_EXPOLINE
ifeq ($(call cc-option-yn,$(CC_FLAGS_MARCH) -mindirect-branch=thunk),y)
ifneq ($(call cc-option,$(CC_FLAGS_MARCH) -mindirect-branch=thunk),)
CC_FLAGS_EXPOLINE := -mindirect-branch=thunk
CC_FLAGS_EXPOLINE += -mfunction-return=thunk
CC_FLAGS_EXPOLINE += -mindirect-branch-table
......@@ -104,10 +104,10 @@ ifdef CONFIG_EXPOLINE
endif
ifdef CONFIG_FUNCTION_TRACER
ifeq ($(call cc-option-yn,-mfentry -mnop-mcount),n)
ifeq ($(call cc-option,-mfentry -mnop-mcount),)
# make use of hotpatch feature if the compiler supports it
cc_hotpatch := -mhotpatch=0,3
ifeq ($(call cc-option-yn,$(cc_hotpatch)),y)
ifneq ($(call cc-option,$(cc_hotpatch)),)
CC_FLAGS_FTRACE := $(cc_hotpatch)
KBUILD_AFLAGS += -DCC_USING_HOTPATCH
KBUILD_CFLAGS += -DCC_USING_HOTPATCH
......
// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/stdarg.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <asm/stacktrace.h>
......@@ -8,7 +9,6 @@
#include <asm/setup.h>
#include <asm/sclp.h>
#include <asm/uv.h>
#include <stdarg.h>
#include "boot.h"
const char hex_asc[] = "0123456789abcdef";
......
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