linux/Makefile

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 15:07:57 +01:00
# SPDX-License-Identifier: GPL-2.0
2019-01-07 02:08:20 +01:00
VERSION = 5
PATCHLEVEL = 0
SUBLEVEL = 0
2019-01-07 02:08:20 +01:00
EXTRAVERSION = -rc1
2018-11-25 23:19:31 +01:00
NAME = Shy Crocodile
# *DOCUMENTATION*
# To see a list of typical targets execute "make help"
# More info can be located in ./README
# Comments in this file are targeted only to the developer, do not
# expect to learn how to build the kernel reading this file.
# That's our default target when none is given on the command line
PHONY := _all
_all:
# Do not use make's built-in rules and variables
# (this increases performance and avoids hard-to-debug behaviour)
MAKEFLAGS += -rR
# Avoid funny character set dependencies
unexport LC_ALL
LC_COLLATE=C
LC_NUMERIC=C
export LC_COLLATE LC_NUMERIC
# Avoid interference with shell env settings
unexport GREP_OPTIONS
# We are using a recursive build, so we need to do a little thinking
# to get the ordering right.
#
# Most importantly: sub-Makefiles should only ever modify files in
# their own directory. If in some directory we have a dependency on
# a file in another dir (which doesn't happen often, but it's often
# unavoidable when linking the built-in.a targets which finally
# turn into vmlinux), we will call a sub make in that other dir, and
# after that we are sure that everything which is in that other dir
# is now up to date.
#
# The only cases where we need to modify files which have global
# effects are thus separated out and done before the recursive
# descending is started. They are now explicitly listed as the
# prepare rule.
# Beautify output
# ---------------------------------------------------------------------------
#
# Normally, we echo the whole command before executing it. By making
# that echo $($(quiet)$(cmd)), we now have the possibility to set
# $(quiet) to choose other forms of output instead, e.g.
#
# quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
# cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
#
# If $(quiet) is empty, the whole command will be printed.
# If it is set to "quiet_", only the short version will be printed.
# If it is set to "silent_", nothing will be printed at all, since
# the variable $(silent_cmd_cc_o_c) doesn't exist.
#
# A simple variant is to prefix commands with $(Q) - that's useful
# for commands that shall be hidden in non-verbose mode.
#
# $(Q)ln $@ :<
#
# If KBUILD_VERBOSE equals 0 then the above command will be hidden.
# If KBUILD_VERBOSE equals 1 then the above command is displayed.
#
# To put more focus on warnings, be less verbose as default
# Use 'make V=1' to see the full commands
ifeq ("$(origin V)", "command line")
KBUILD_VERBOSE = $(V)
endif
ifndef KBUILD_VERBOSE
KBUILD_VERBOSE = 0
endif
ifeq ($(KBUILD_VERBOSE),1)
quiet =
Q =
else
quiet=quiet_
Q = @
endif
# If the user is running make -s (silent mode), suppress echoing of
# commands
ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
quiet=silent_
tools_silent=s
endif
export quiet Q KBUILD_VERBOSE
# kbuild supports saving output files in a separate directory.
# To locate output files in a separate directory two syntaxes are supported.
# In both cases the working directory must be the root of the kernel src.
# 1) O=
# Use "make O=dir/to/store/output/files/"
#
# 2) Set KBUILD_OUTPUT
# Set the environment variable KBUILD_OUTPUT to point to the directory
# where the output files shall be placed.
# export KBUILD_OUTPUT=dir/to/store/output/files/
# make
#
# The O= assignment takes precedence over the KBUILD_OUTPUT environment
# variable.
# KBUILD_SRC is not intended to be used by the regular user (for now),
# it is set on invocation of make with KBUILD_OUTPUT or O= specified.
ifeq ($(KBUILD_SRC),)
# OK, Make called in directory where kernel src resides
# Do we want to locate output files in a separate directory?
ifeq ("$(origin O)", "command line")
KBUILD_OUTPUT := $(O)
endif
# Cancel implicit rules on top Makefile
$(CURDIR)/Makefile Makefile: ;
ifneq ($(words $(subst :, ,$(CURDIR))), 1)
$(error main directory cannot contain spaces nor colons)
endif
ifneq ($(KBUILD_OUTPUT),)
# check that the output directory actually exists
saved-output := $(KBUILD_OUTPUT)
KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
&& pwd)
$(if $(KBUILD_OUTPUT),, \
$(error failed to create output directory "$(saved-output)"))
# 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. It is OK since we are going to invoke
# 'sub-make' below.
MAKEFLAGS += --include-dir=$(CURDIR)
PHONY += $(MAKECMDGOALS) sub-make
$(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
@:
# Invoke a second make in the output directory, passing relevant variables
sub-make:
$(Q)$(MAKE) -C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR) \
-f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))
# Leave processing to above invocation of make
skip-makefile := 1
endif # ifneq ($(KBUILD_OUTPUT),)
endif # ifeq ($(KBUILD_SRC),)
# We process the rest of the Makefile if this is the final invocation of make
ifeq ($(skip-makefile),)
# Do not print "Entering directory ...",
# but we want to display it when entering to the output directory
# so that IDEs/editors are able to understand relative filenames.
MAKEFLAGS += --no-print-directory
# Call a source code checker (by default, "sparse") as part of the
# C compilation.
#
# Use 'make C=1' to enable checking of only re-compiled files.
# Use 'make C=2' to enable checking of *all* source files, regardless
# of whether they are re-compiled or not.
#
# See the file "Documentation/dev-tools/sparse.rst" for more details,
# including where to get the "sparse" utility.
ifeq ("$(origin C)", "command line")
KBUILD_CHECKSRC = $(C)
endif
ifndef KBUILD_CHECKSRC
KBUILD_CHECKSRC = 0
endif
# Use make M=dir to specify directory of external module to build
# Old syntax make ... SUBDIRS=$PWD is still supported
# Setting the environment variable KBUILD_EXTMOD take precedence
ifdef SUBDIRS
$(warning ================= WARNING ================)
$(warning 'SUBDIRS' will be removed after Linux 5.3)
$(warning Please use 'M=' or 'KBUILD_EXTMOD' instead)
$(warning ==========================================)
KBUILD_EXTMOD ?= $(SUBDIRS)
endif
ifeq ("$(origin M)", "command line")
KBUILD_EXTMOD := $(M)
endif
ifeq ($(KBUILD_SRC),)
# building in the source tree
srctree := .
else
ifeq ($(KBUILD_SRC)/,$(dir $(CURDIR)))
# building in a subdirectory of the source tree
srctree := ..
else
srctree := $(KBUILD_SRC)
endif
endif
export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC
objtree := .
src := $(srctree)
obj := $(objtree)
VPATH := $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
export srctree objtree VPATH
# To make sure we do not include .config for any of the *config targets
# catch them early, and hand them over to scripts/kconfig/Makefile
# It is allowed to specify more targets when calling make, including
# mixing *config targets and build targets.
# For example 'make oldconfig all'.
# Detect when mixed targets is specified, and make a second invocation
# of make so .config is not included in this case either (for *config).
version_h := include/generated/uapi/linux/version.h
old_version_h := include/linux/version.h
clean-targets := %clean mrproper cleandocs
no-dot-config-targets := $(clean-targets) \
cscope gtags TAGS tags help% %docs check% coccicheck \
$(version_h) headers_% archheaders archscripts \
%asm-generic kernelversion %src-pkg
no-sync-config-targets := $(no-dot-config-targets) install %install \
kernelrelease
kbuild: do not update config when running install targets "make syncconfig" is automatically invoked when any of the following happens: - .config is updated - any of Kconfig files is updated - any of environment variables referenced in Kconfig is changed Then, it updates configuration files such as include/config/auto.conf include/generated/autoconf.h, etc. Even install targets (install, modules_install, etc.) are no exception. However, they should never ever modify the source tree. Install targets are often run with root privileges. Once those configuration files are owned by root, "make mrproper" would end up with permission error. Install targets should just copy things blindly. They should not care whether the configuration is up-to-date or not. This makes more sense because we are interested in the configuration that was used in the previous kernel building. This issue has existed since before, but rarely happened. I expect more chance where people are hit by this; with the new Kconfig syntax extension, the .config now contains the compiler information. If you cross-compile the kernel with CROSS_COMPILE, but forget to pass it for "make install", you meet "any of environment variables referenced in Kconfig is changed" because $(CC) is referenced in Kconfig. Another scenario is the compiler upgrade before the installation. Install targets need the configuration. "make modules_install" refer to CONFIG_MODULES etc. "make dtbs_install" also needs CONFIG_ARCH_* to decide which dtb files to install. However, the auto-update of the configuration files should be avoided. We already do this for external modules. Now, Make targets are categorized into 3 groups: [1] Do not need the kernel configuration at all help, coccicheck, headers_install etc. [2] Need the latest kernel configuration If new config options are added, Kconfig will show prompt to ask user's selection. Build targets such as vmlinux, in-kernel modules are the cases. [3] Need the kernel configuration, but do not want to update it Install targets except headers_install, and external modules are the cases. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-20 09:46:34 +02:00
config-targets := 0
mixed-targets := 0
dot-config := 1
may-sync-config := 1
ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
dot-config := 0
endif
endif
kbuild: do not update config when running install targets "make syncconfig" is automatically invoked when any of the following happens: - .config is updated - any of Kconfig files is updated - any of environment variables referenced in Kconfig is changed Then, it updates configuration files such as include/config/auto.conf include/generated/autoconf.h, etc. Even install targets (install, modules_install, etc.) are no exception. However, they should never ever modify the source tree. Install targets are often run with root privileges. Once those configuration files are owned by root, "make mrproper" would end up with permission error. Install targets should just copy things blindly. They should not care whether the configuration is up-to-date or not. This makes more sense because we are interested in the configuration that was used in the previous kernel building. This issue has existed since before, but rarely happened. I expect more chance where people are hit by this; with the new Kconfig syntax extension, the .config now contains the compiler information. If you cross-compile the kernel with CROSS_COMPILE, but forget to pass it for "make install", you meet "any of environment variables referenced in Kconfig is changed" because $(CC) is referenced in Kconfig. Another scenario is the compiler upgrade before the installation. Install targets need the configuration. "make modules_install" refer to CONFIG_MODULES etc. "make dtbs_install" also needs CONFIG_ARCH_* to decide which dtb files to install. However, the auto-update of the configuration files should be avoided. We already do this for external modules. Now, Make targets are categorized into 3 groups: [1] Do not need the kernel configuration at all help, coccicheck, headers_install etc. [2] Need the latest kernel configuration If new config options are added, Kconfig will show prompt to ask user's selection. Build targets such as vmlinux, in-kernel modules are the cases. [3] Need the kernel configuration, but do not want to update it Install targets except headers_install, and external modules are the cases. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-20 09:46:34 +02:00
ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
may-sync-config := 0
endif
endif
ifneq ($(KBUILD_EXTMOD),)
may-sync-config := 0
endif
ifeq ($(KBUILD_EXTMOD),)
ifneq ($(filter config %config,$(MAKECMDGOALS)),)
config-targets := 1
ifneq ($(words $(MAKECMDGOALS)),1)
mixed-targets := 1
endif
endif
endif
# For "make -j clean all", "make -j mrproper defconfig all", etc.
ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
mixed-targets := 1
endif
endif
# install and modules_install need also be processed one by one
ifneq ($(filter install,$(MAKECMDGOALS)),)
ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
mixed-targets := 1
endif
endif
ifeq ($(mixed-targets),1)
# ===========================================================================
# We're called with mixed targets (*config and build targets).
# Handle them one by one.
PHONY += $(MAKECMDGOALS) __build_one_by_one
$(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
@:
__build_one_by_one:
$(Q)set -e; \
for i in $(MAKECMDGOALS); do \
$(MAKE) -f $(srctree)/Makefile $$i; \
done
else
# We need some generic definitions (do not try to remake the file).
scripts/Kbuild.include: ;
include scripts/Kbuild.include
# Read KERNELRELEASE from include/config/kernel.release (if it exists)
KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
include scripts/subarch.include
# Cross compiling and selecting different set of gcc/bin-utils
# ---------------------------------------------------------------------------
#
# When performing cross compilation for other architectures ARCH shall be set
# to the target architecture. (See arch/* for the possibilities).
# ARCH can be set during invocation of make:
# make ARCH=ia64
# Another way is to have ARCH set in the environment.
# The default ARCH is the host where make is executed.
# CROSS_COMPILE specify the prefix used for all executables used
# during compilation. Only gcc and related bin-utils executables
# are prefixed with $(CROSS_COMPILE).
# CROSS_COMPILE can be set on the command line
# make CROSS_COMPILE=ia64-linux-
# Alternatively CROSS_COMPILE can be set in the environment.
# Default value for CROSS_COMPILE is not to prefix executables
# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
ARCH ?= $(SUBARCH)
# Architecture as present in compile.h
UTS_MACHINE := $(ARCH)
SRCARCH := $(ARCH)
# Additional ARCH settings for x86
ifeq ($(ARCH),i386)
SRCARCH := x86
endif
ifeq ($(ARCH),x86_64)
SRCARCH := x86
endif
# Additional ARCH settings for sparc
ifeq ($(ARCH),sparc32)
SRCARCH := sparc
endif
ifeq ($(ARCH),sparc64)
SRCARCH := sparc
endif
# Additional ARCH settings for sh
ifeq ($(ARCH),sh64)
SRCARCH := sh
endif
KCONFIG_CONFIG ?= .config
export KCONFIG_CONFIG
# SHELL used by kbuild
CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
else if [ -x /bin/bash ]; then echo /bin/bash; \
else echo sh; fi ; fi)
HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
HOSTCC = gcc
HOSTCXX = g++
KBUILD_HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \
-fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS) \
$(HOSTCFLAGS)
KBUILD_HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
# Make variables (CC, etc...)
AS = $(CROSS_COMPILE)as
LD = $(CROSS_COMPILE)ld
CC = $(CROSS_COMPILE)gcc
CPP = $(CC) -E
AR = $(CROSS_COMPILE)ar
NM = $(CROSS_COMPILE)nm
STRIP = $(CROSS_COMPILE)strip
OBJCOPY = $(CROSS_COMPILE)objcopy
OBJDUMP = $(CROSS_COMPILE)objdump
LEX = flex
YACC = bison
AWK = awk
GENKSYMS = scripts/genksyms/genksyms
kbuild: use INSTALLKERNEL to select customized installkernel script Replace the use of CROSS_COMPILE to select a customized installkernel script with the possibility to set INSTALLKERNEL to select a custom installkernel script when running make: make INSTALLKERNEL=arm-installkernel install With this patch we are now more consistent across different architectures - they did not all support use of CROSS_COMPILE. The use of CROSS_COMPILE was a hack as this really belongs to gcc/binutils and the installkernel script does not change just because we change toolchain. The use of CROSS_COMPILE caused troubles with an upcoming patch that saves CROSS_COMPILE when a kernel is built - it would no longer be installable. [Thanks to Peter Z. for this hint] This patch undos what Ian did in commit: 0f8e2d62fa04441cd12c08ce521e84e5bd3f8a46 ("use ${CROSS_COMPILE}installkernel in arch/*/boot/install.sh") The patch has been lightly tested on x86 only - but all changes looks obvious. Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Frysinger <vapier@gentoo.org> [blackfin] Acked-by: Russell King <linux@arm.linux.org.uk> [arm] Acked-by: Paul Mundt <lethal@linux-sh.org> [sh] Acked-by: "H. Peter Anvin" <hpa@zytor.com> [x86] Cc: Ian Campbell <icampbell@arcom.com> Cc: Tony Luck <tony.luck@intel.com> [ia64] Cc: Fenghua Yu <fenghua.yu@intel.com> [ia64] Cc: Hirokazu Takata <takata@linux-m32r.org> [m32r] Cc: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Cc: Kyle McMartin <kyle@mcmartin.ca> [parisc] Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> [powerpc] Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> [s390] Cc: Thomas Gleixner <tglx@linutronix.de> [x86] Cc: Ingo Molnar <mingo@redhat.com> [x86] Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2009-07-20 21:37:11 +02:00
INSTALLKERNEL := installkernel
DEPMOD = /sbin/depmod
PERL = perl
PYTHON = python
kbuild: add PYTHON2 and PYTHON3 variables The variable 'PYTHON' allows users to specify a proper executable name in case the default 'python' does not work. However, this does not address the case where both Python 2.x and 3.x scripts are used in one source tree. PEP 394 (https://www.python.org/dev/peps/pep-0394/) provides a convention for Python scripts portability. Here is a quotation: In order to tolerate differences across platforms, all new code that needs to invoke the Python interpreter should not specify 'python', but rather should specify either 'python2' or 'python3'. This distinction should be made in shebangs, when invoking from a shell script, when invoking via the system() call, or when invoking in any other context. One exception to this is scripts that are deliberately written to be source compatible with both Python 2.x and 3.x. Such scripts may continue to use python on their shebang line without affecting their portability. To meet this requirement, this commit adds new variables 'PYTHON2' and 'PYTHON3'. arch/ia64/scripts/unwcheck.py is the only script that has ever used $(PYTHON). Recent commit bd5edbe67794 ("ia64: convert unwcheck.py to python3") converted it to be compatible with both Python 2.x and 3.x, so this is the exceptional case where the use of 'python' is allowed. So, I did not touch arch/ia64/Makefile. tools/perf/Makefile.config sets PYTHON and PYTHON2 by itself, so it is not affected by this commit. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-03-13 10:12:02 +01:00
PYTHON2 = python2
PYTHON3 = python3
CHECK = sparse
CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
-Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
NOSTDINC_FLAGS =
kbuild: allow assignment to {A,C,LD}FLAGS_MODULE on the command line It is now possible to assign options to AS, CC and LD on the command line - which is only used when building modules. {A,C,LD}FLAGS_MODULE was all used both in the top-level Makefile in the arch makefiles, thus users had no way to specify additional options to AS, CC, LD when building modules without overriding the original value. Introduce a new set of variables KBUILD_{A,C,LD}FLAGS_MODULE that is used by arch specific files and free up {A,C,LD}FLAGS_MODULE so they can be assigned on the command line. All arch Makefiles that used the old variables has been updated. Note: Previously we had a MODFLAGS variable for both AS and CC. But in favour of consistency this was dropped. So in some cases arch Makefile has one assignmnet replaced by two assignmnets. Note2: MODFLAGS was not documented and is dropped without any notice. I do not expect much/any breakage from this. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Denys Vlasenko <vda.linux@googlemail.com> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Chen Liqin <liqin.chen@sunplusct.com> Acked-by: Mike Frysinger <vapier@gentoo.org> [blackfin] Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> [avr32] Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-07-28 17:33:09 +02:00
CFLAGS_MODULE =
AFLAGS_MODULE =
LDFLAGS_MODULE =
CFLAGS_KERNEL =
AFLAGS_KERNEL =
LDFLAGS_vmlinux =
# Use USERINCLUDE when you must reference the UAPI directories only.
USERINCLUDE := \
-I$(srctree)/arch/$(SRCARCH)/include/uapi \
-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
-I$(srctree)/include/uapi \
-I$(objtree)/include/generated/uapi \
-include $(srctree)/include/linux/kconfig.h
# Use LINUXINCLUDE when you must reference the include/ directory.
# Needed to be compatible with the O= option
LINUXINCLUDE := \
-I$(srctree)/arch/$(SRCARCH)/include \
-I$(objtree)/arch/$(SRCARCH)/include/generated \
$(if $(KBUILD_SRC), -I$(srctree)/include) \
-I$(objtree)/include \
$(USERINCLUDE)
KBUILD_AFLAGS := -D__ASSEMBLY__ -fno-PIE
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 \
-Wno-format-security \
-std=gnu89
KBUILD_CPPFLAGS := -D__KERNEL__
KBUILD_AFLAGS_KERNEL :=
KBUILD_CFLAGS_KERNEL :=
kbuild: allow assignment to {A,C,LD}FLAGS_MODULE on the command line It is now possible to assign options to AS, CC and LD on the command line - which is only used when building modules. {A,C,LD}FLAGS_MODULE was all used both in the top-level Makefile in the arch makefiles, thus users had no way to specify additional options to AS, CC, LD when building modules without overriding the original value. Introduce a new set of variables KBUILD_{A,C,LD}FLAGS_MODULE that is used by arch specific files and free up {A,C,LD}FLAGS_MODULE so they can be assigned on the command line. All arch Makefiles that used the old variables has been updated. Note: Previously we had a MODFLAGS variable for both AS and CC. But in favour of consistency this was dropped. So in some cases arch Makefile has one assignmnet replaced by two assignmnets. Note2: MODFLAGS was not documented and is dropped without any notice. I do not expect much/any breakage from this. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Denys Vlasenko <vda.linux@googlemail.com> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Chen Liqin <liqin.chen@sunplusct.com> Acked-by: Mike Frysinger <vapier@gentoo.org> [blackfin] Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> [avr32] Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-07-28 17:33:09 +02:00
KBUILD_AFLAGS_MODULE := -DMODULE
KBUILD_CFLAGS_MODULE := -DMODULE
KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
KBUILD_LDFLAGS :=
GCC_PLUGINS_CFLAGS :=
export ARCH SRCARCH CONFIG_SHELL HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE AS LD CC
export CPP AR NM STRIP OBJCOPY OBJDUMP KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS
kbuild: add PYTHON2 and PYTHON3 variables The variable 'PYTHON' allows users to specify a proper executable name in case the default 'python' does not work. However, this does not address the case where both Python 2.x and 3.x scripts are used in one source tree. PEP 394 (https://www.python.org/dev/peps/pep-0394/) provides a convention for Python scripts portability. Here is a quotation: In order to tolerate differences across platforms, all new code that needs to invoke the Python interpreter should not specify 'python', but rather should specify either 'python2' or 'python3'. This distinction should be made in shebangs, when invoking from a shell script, when invoking via the system() call, or when invoking in any other context. One exception to this is scripts that are deliberately written to be source compatible with both Python 2.x and 3.x. Such scripts may continue to use python on their shebang line without affecting their portability. To meet this requirement, this commit adds new variables 'PYTHON2' and 'PYTHON3'. arch/ia64/scripts/unwcheck.py is the only script that has ever used $(PYTHON). Recent commit bd5edbe67794 ("ia64: convert unwcheck.py to python3") converted it to be compatible with both Python 2.x and 3.x, so this is the exceptional case where the use of 'python' is allowed. So, I did not touch arch/ia64/Makefile. tools/perf/Makefile.config sets PYTHON and PYTHON2 by itself, so it is not affected by this commit. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-03-13 10:12:02 +01:00
export MAKE LEX YACC AWK GENKSYMS INSTALLKERNEL PERL PYTHON PYTHON2 PYTHON3 UTS_MACHINE
export HOSTCXX KBUILD_HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
kbuild: allow assignment to {A,C,LD}FLAGS_MODULE on the command line It is now possible to assign options to AS, CC and LD on the command line - which is only used when building modules. {A,C,LD}FLAGS_MODULE was all used both in the top-level Makefile in the arch makefiles, thus users had no way to specify additional options to AS, CC, LD when building modules without overriding the original value. Introduce a new set of variables KBUILD_{A,C,LD}FLAGS_MODULE that is used by arch specific files and free up {A,C,LD}FLAGS_MODULE so they can be assigned on the command line. All arch Makefiles that used the old variables has been updated. Note: Previously we had a MODFLAGS variable for both AS and CC. But in favour of consistency this was dropped. So in some cases arch Makefile has one assignmnet replaced by two assignmnets. Note2: MODFLAGS was not documented and is dropped without any notice. I do not expect much/any breakage from this. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Denys Vlasenko <vda.linux@googlemail.com> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Chen Liqin <liqin.chen@sunplusct.com> Acked-by: Mike Frysinger <vapier@gentoo.org> [blackfin] Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> [avr32] Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-07-28 17:33:09 +02:00
export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
export KBUILD_ARFLAGS
# 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.
export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
# Files to ignore in find ... statements
export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
-name CVS -o -name .pc -o -name .hg -o -name .git \) \
-prune -o
export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
--exclude CVS --exclude .pc --exclude .hg --exclude .git
# ===========================================================================
# Rules shared between *config targets and build targets
# Basic helpers built in scripts/basic/
PHONY += scripts_basic
scripts_basic:
$(Q)$(MAKE) $(build)=scripts/basic
$(Q)rm -f .tmp_quiet_recordmcount
# To avoid any implicit rule to kick in, define an empty command.
scripts/basic/%: scripts_basic ;
PHONY += outputmakefile
# outputmakefile generates a Makefile in the output directory, if using a
# separate output directory. This allows convenient use of make in the
# output directory.
outputmakefile:
ifneq ($(KBUILD_SRC),)
$(Q)ln -fsn $(srctree) source
$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
endif
ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
ifneq ($(CROSS_COMPILE),)
CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE:%-=%))
GCC_TOOLCHAIN_DIR := $(dir $(shell which $(LD)))
CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)
GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..)
endif
ifneq ($(GCC_TOOLCHAIN),)
CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN)
endif
CLANG_FLAGS += -no-integrated-as
KBUILD_CFLAGS += $(CLANG_FLAGS)
KBUILD_AFLAGS += $(CLANG_FLAGS)
export CLANG_FLAGS
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)))
export RETPOLINE_CFLAGS
export RETPOLINE_VDSO_CFLAGS
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 <geert@linux-m68k.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
2018-06-08 02:21:43 +02:00
# 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
# in scripts/kconfig to make the *config target
# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
# KBUILD_DEFCONFIG may point out an alternative default configuration
# used for 'make defconfig'
include arch/$(SRCARCH)/Makefile
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 <geert@linux-m68k.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
2018-06-08 02:21:43 +02:00
export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
config: scripts_basic outputmakefile FORCE
$(Q)$(MAKE) $(build)=scripts/kconfig $@
%config: scripts_basic outputmakefile FORCE
$(Q)$(MAKE) $(build)=scripts/kconfig $@
else
# ===========================================================================
# Build targets only - this includes vmlinux, arch specific targets, clean
# targets and others. In general all targets except *config targets.
# If building an external module we do not care about the all: rule
# but instead _all depend on modules
PHONY += all
ifeq ($(KBUILD_EXTMOD),)
_all: all
else
_all: modules
endif
# Decide whether to build built-in, modular, or both.
# Normally, just do built-in.
KBUILD_MODULES :=
KBUILD_BUILTIN := 1
# If we have only "make modules", don't compile built-in objects.
# When we're building modules with modversions, we need to consider
# the built-in objects during the descend as well, in order to
# make sure the checksums are up to date before we record them.
ifeq ($(MAKECMDGOALS),modules)
KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
endif
# If we have "make <whatever> modules", compile modules
# in addition to whatever we do anyway.
# Just "make" or "make all" shall build modules as well
ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
KBUILD_MODULES := 1
endif
ifeq ($(MAKECMDGOALS),)
KBUILD_MODULES := 1
endif
export KBUILD_MODULES KBUILD_BUILTIN
ifeq ($(KBUILD_EXTMOD),)
# Objects we will link into vmlinux / subdirs we need to visit
init-y := init/
drivers-y := drivers/ sound/ firmware/
net-y := net/
libs-y := lib/
core-y := usr/
virt-y := virt/
endif # KBUILD_EXTMOD
ifeq ($(dot-config),1)
include include/config/auto.conf
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 <geert@linux-m68k.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
2018-06-08 02:21:43 +02:00
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
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 <geert@linux-m68k.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
2018-06-08 02:21:43 +02:00
tracing/Makefile: Fix handling redefinition of CC_FLAGS_FTRACE As a Kernel developer, I make heavy use of "make targz-pkg" in order to locally compile and remotely install my development Kernels. The nice feature I rely on is that after a normal "make", "make targz-pkg" only generates the tarball without having to recompile everything. That was true until commit f28bc3c32c05 ("tracing: Handle CC_FLAGS_FTRACE more accurately"). After it, running "make targz-pkg" after "make" will recompile the whole Kernel tree, making my development workflow much slower. The Kernel is choosing to recompile everything because it claims the command line has changed. A diff of the .cmd files show a repeated -mfentry in one of the files. That is because "make targz-pkg" calls "make modules_install" and the environment is already populated with the exported variables, CC_FLAGS_FTRACE being one of them. Then, -mfentry gets duplicated because it is not protected behind an ifndef block, like -pg. To complicate the problem a little bit more, architectures can define their own version CC_FLAGS_FTRACE, so our code not only has to consider recursive Makefiles, but also architecture overrides. So in this patch we move CC_FLAGS_FTRACE up and unconditionally define it to -pg. Then we let the architecture Makefiles possibly override it, and finally append the extra options later. This ensures the variable is always fully redefined at each invocation so recursive Makefiles don't keep appending, and hopefully it maintains the intended behavior on how architectures can override the defaults.. Thanks Steven Rostedt and Vasily Gorbik for the help on this regression. Cc: Michal Marek <michal.lkml@markovi.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: linux-kbuild@vger.kernel.org Fixes: commit f28bc3c32c05 ("tracing: Handle CC_FLAGS_FTRACE more accurately") Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-09-10 19:59:56 +02:00
# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
ifdef CONFIG_FUNCTION_TRACER
CC_FLAGS_FTRACE := -pg
endif
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 <geert@linux-m68k.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
2018-06-08 02:21:43 +02:00
# 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
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 <geert@linux-m68k.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
2018-06-08 02:21:43 +02:00
ifeq ($(dot-config),1)
kbuild: do not update config when running install targets "make syncconfig" is automatically invoked when any of the following happens: - .config is updated - any of Kconfig files is updated - any of environment variables referenced in Kconfig is changed Then, it updates configuration files such as include/config/auto.conf include/generated/autoconf.h, etc. Even install targets (install, modules_install, etc.) are no exception. However, they should never ever modify the source tree. Install targets are often run with root privileges. Once those configuration files are owned by root, "make mrproper" would end up with permission error. Install targets should just copy things blindly. They should not care whether the configuration is up-to-date or not. This makes more sense because we are interested in the configuration that was used in the previous kernel building. This issue has existed since before, but rarely happened. I expect more chance where people are hit by this; with the new Kconfig syntax extension, the .config now contains the compiler information. If you cross-compile the kernel with CROSS_COMPILE, but forget to pass it for "make install", you meet "any of environment variables referenced in Kconfig is changed" because $(CC) is referenced in Kconfig. Another scenario is the compiler upgrade before the installation. Install targets need the configuration. "make modules_install" refer to CONFIG_MODULES etc. "make dtbs_install" also needs CONFIG_ARCH_* to decide which dtb files to install. However, the auto-update of the configuration files should be avoided. We already do this for external modules. Now, Make targets are categorized into 3 groups: [1] Do not need the kernel configuration at all help, coccicheck, headers_install etc. [2] Need the latest kernel configuration If new config options are added, Kconfig will show prompt to ask user's selection. Build targets such as vmlinux, in-kernel modules are the cases. [3] Need the kernel configuration, but do not want to update it Install targets except headers_install, and external modules are the cases. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-20 09:46:34 +02:00
ifeq ($(may-sync-config),1)
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 <geert@linux-m68k.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
2018-06-08 02:21:43 +02:00
# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
# because some architectures define CROSS_COMPILE there.
-include include/config/auto.conf.cmd
# To avoid any implicit rule to kick in, define an empty command
$(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
2018-02-13 08:58:20 +01:00
# The actual configuration files used during the build are stored in
# include/generated/ and include/config/. Update them if .config is newer than
# include/config/auto.conf (which mirrors .config).
include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
else
kbuild: do not update config when running install targets "make syncconfig" is automatically invoked when any of the following happens: - .config is updated - any of Kconfig files is updated - any of environment variables referenced in Kconfig is changed Then, it updates configuration files such as include/config/auto.conf include/generated/autoconf.h, etc. Even install targets (install, modules_install, etc.) are no exception. However, they should never ever modify the source tree. Install targets are often run with root privileges. Once those configuration files are owned by root, "make mrproper" would end up with permission error. Install targets should just copy things blindly. They should not care whether the configuration is up-to-date or not. This makes more sense because we are interested in the configuration that was used in the previous kernel building. This issue has existed since before, but rarely happened. I expect more chance where people are hit by this; with the new Kconfig syntax extension, the .config now contains the compiler information. If you cross-compile the kernel with CROSS_COMPILE, but forget to pass it for "make install", you meet "any of environment variables referenced in Kconfig is changed" because $(CC) is referenced in Kconfig. Another scenario is the compiler upgrade before the installation. Install targets need the configuration. "make modules_install" refer to CONFIG_MODULES etc. "make dtbs_install" also needs CONFIG_ARCH_* to decide which dtb files to install. However, the auto-update of the configuration files should be avoided. We already do this for external modules. Now, Make targets are categorized into 3 groups: [1] Do not need the kernel configuration at all help, coccicheck, headers_install etc. [2] Need the latest kernel configuration If new config options are added, Kconfig will show prompt to ask user's selection. Build targets such as vmlinux, in-kernel modules are the cases. [3] Need the kernel configuration, but do not want to update it Install targets except headers_install, and external modules are the cases. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-20 09:46:34 +02:00
# External modules and some install targets need include/generated/autoconf.h
# and include/config/auto.conf but do not care if they are up-to-date.
# Use auto.conf to trigger the test
PHONY += include/config/auto.conf
include/config/auto.conf:
$(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
echo >&2; \
echo >&2 " ERROR: Kernel configuration is invalid."; \
echo >&2 " include/generated/autoconf.h or $@ are missing.";\
echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
echo >&2 ; \
/bin/false)
kbuild: do not update config when running install targets "make syncconfig" is automatically invoked when any of the following happens: - .config is updated - any of Kconfig files is updated - any of environment variables referenced in Kconfig is changed Then, it updates configuration files such as include/config/auto.conf include/generated/autoconf.h, etc. Even install targets (install, modules_install, etc.) are no exception. However, they should never ever modify the source tree. Install targets are often run with root privileges. Once those configuration files are owned by root, "make mrproper" would end up with permission error. Install targets should just copy things blindly. They should not care whether the configuration is up-to-date or not. This makes more sense because we are interested in the configuration that was used in the previous kernel building. This issue has existed since before, but rarely happened. I expect more chance where people are hit by this; with the new Kconfig syntax extension, the .config now contains the compiler information. If you cross-compile the kernel with CROSS_COMPILE, but forget to pass it for "make install", you meet "any of environment variables referenced in Kconfig is changed" because $(CC) is referenced in Kconfig. Another scenario is the compiler upgrade before the installation. Install targets need the configuration. "make modules_install" refer to CONFIG_MODULES etc. "make dtbs_install" also needs CONFIG_ARCH_* to decide which dtb files to install. However, the auto-update of the configuration files should be avoided. We already do this for external modules. Now, Make targets are categorized into 3 groups: [1] Do not need the kernel configuration at all help, coccicheck, headers_install etc. [2] Need the latest kernel configuration If new config options are added, Kconfig will show prompt to ask user's selection. Build targets such as vmlinux, in-kernel modules are the cases. [3] Need the kernel configuration, but do not want to update it Install targets except headers_install, and external modules are the cases. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-20 09:46:34 +02:00
endif # may-sync-config
endif # $(dot-config)
KBUILD_CFLAGS += $(call cc-option,-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)
KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,)
else
ifdef CONFIG_PROFILE_ALL_BRANCHES
Kbuild: enable -Wmaybe-uninitialized warning for "make W=1" Traditionally, we have always had warnings about uninitialized variables enabled, as this is part of -Wall, and generally a good idea [1], but it also always produced false positives, mainly because this is a variation of the halting problem and provably impossible to get right in all cases [2]. Various people have identified cases that are particularly bad for false positives, and in commit e74fc973b6e5 ("Turn off -Wmaybe-uninitialized when building with -Os"), I turned off the warning for any build that was done with CC_OPTIMIZE_FOR_SIZE. This drastically reduced the number of false positive warnings in the default build but unfortunately had the side effect of turning the warning off completely in 'allmodconfig' builds, which in turn led to a lot of warnings (both actual bugs, and remaining false positives) to go in unnoticed. With commit 877417e6ffb9 ("Kbuild: change CC_OPTIMIZE_FOR_SIZE definition") enabled the warning again for allmodconfig builds in v4.7 and in v4.8-rc1, I had finally managed to address all warnings I get in an ARM allmodconfig build and most other maybe-uninitialized warnings for ARM randconfig builds. However, commit 6e8d666e9253 ("Disable "maybe-uninitialized" warning globally") was merged at the same time and disabled it completely for all configurations, because of false-positive warnings on x86 that I had not addressed until then. This caused a lot of actual bugs to get merged into mainline, and I sent several dozen patches for these during the v4.9 development cycle. Most of these are actual bugs, some are for correct code that is safe because it is only called under external constraints that make it impossible to run into the case that gcc sees, and in a few cases gcc is just stupid and finds something that can obviously never happen. I have now done a few thousand randconfig builds on x86 and collected all patches that I needed to address every single warning I got (I can provide the combined patch for the other warnings if anyone is interested), so I hope we can get the warning back and let people catch the actual bugs earlier. This reverts the change to disable the warning completely and for now brings it back at the "make W=1" level, so we can get it merged into mainline without introducing false positives. A follow-up patch enables it on all levels unless some configuration option turns it off because of false-positives. Link: https://rusty.ozlabs.org/?p=232 [1] Link: https://gcc.gnu.org/wiki/Better_Uninitialized_Warnings [2] Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-10 17:44:44 +01:00
KBUILD_CFLAGS += -O2 $(call cc-disable-warning,maybe-uninitialized,)
else
KBUILD_CFLAGS += -O2
endif
endif
Kbuild: enable -Wmaybe-uninitialized warning for "make W=1" Traditionally, we have always had warnings about uninitialized variables enabled, as this is part of -Wall, and generally a good idea [1], but it also always produced false positives, mainly because this is a variation of the halting problem and provably impossible to get right in all cases [2]. Various people have identified cases that are particularly bad for false positives, and in commit e74fc973b6e5 ("Turn off -Wmaybe-uninitialized when building with -Os"), I turned off the warning for any build that was done with CC_OPTIMIZE_FOR_SIZE. This drastically reduced the number of false positive warnings in the default build but unfortunately had the side effect of turning the warning off completely in 'allmodconfig' builds, which in turn led to a lot of warnings (both actual bugs, and remaining false positives) to go in unnoticed. With commit 877417e6ffb9 ("Kbuild: change CC_OPTIMIZE_FOR_SIZE definition") enabled the warning again for allmodconfig builds in v4.7 and in v4.8-rc1, I had finally managed to address all warnings I get in an ARM allmodconfig build and most other maybe-uninitialized warnings for ARM randconfig builds. However, commit 6e8d666e9253 ("Disable "maybe-uninitialized" warning globally") was merged at the same time and disabled it completely for all configurations, because of false-positive warnings on x86 that I had not addressed until then. This caused a lot of actual bugs to get merged into mainline, and I sent several dozen patches for these during the v4.9 development cycle. Most of these are actual bugs, some are for correct code that is safe because it is only called under external constraints that make it impossible to run into the case that gcc sees, and in a few cases gcc is just stupid and finds something that can obviously never happen. I have now done a few thousand randconfig builds on x86 and collected all patches that I needed to address every single warning I got (I can provide the combined patch for the other warnings if anyone is interested), so I hope we can get the warning back and let people catch the actual bugs earlier. This reverts the change to disable the warning completely and for now brings it back at the "make W=1" level, so we can get it merged into mainline without introducing false positives. A follow-up patch enables it on all levels unless some configuration option turns it off because of false-positives. Link: https://rusty.ozlabs.org/?p=232 [1] Link: https://gcc.gnu.org/wiki/Better_Uninitialized_Warnings [2] Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-10 17:44:44 +01:00
KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
$(call cc-disable-warning,maybe-uninitialized,))
./Makefile: tell gcc optimizer to never introduce new data races We have been chasing a memory corruption bug, which turned out to be caused by very old gcc (4.3.4), which happily turned conditional load into a non-conditional one, and that broke correctness (the condition was met only if lock was held) and corrupted memory. This particular problem with that particular code did not happen when never gccs were used. I've brought this up with our gcc folks, as I wanted to make sure that this can't really happen again, and it turns out it actually can. Quoting Martin Jambor <mjambor@suse.cz>: "More current GCCs are more careful when it comes to replacing a conditional load with a non-conditional one, most notably they check that a store happens in each iteration of _a_ loop but they assume loops are executed. They also perform a simple check whether the store cannot trap which currently passes only for non-const variables. A simple testcase demonstrating it on an x86_64 is for example the following: $ cat cond_store.c int g_1 = 1; int g_2[1024] __attribute__((section ("safe_section"), aligned (4096))); int c = 4; int __attribute__ ((noinline)) foo (void) { int l; for (l = 0; (l != 4); l++) { if (g_1) return l; for (g_2[0] = 0; (g_2[0] >= 26); ++g_2[0]) ; } return 2; } int main (int argc, char* argv[]) { if (mprotect (g_2, sizeof(g_2), PROT_READ) == -1) { int e = errno; error (e, e, "mprotect error %i", e); } foo (); __builtin_printf("OK\n"); return 0; } /* EOF */ $ ~/gcc/trunk/inst/bin/gcc cond_store.c -O2 --param allow-store-data-races=0 $ ./a.out OK $ ~/gcc/trunk/inst/bin/gcc cond_store.c -O2 --param allow-store-data-races=1 $ ./a.out Segmentation fault The testcase fails the same at least with 4.9, 4.8 and 4.7. Therefore I would suggest building kernels with this parameter set to zero. I also agree with Jikos that the default should be changed for -O2. I have run most of the SPEC 2k6 CPU benchmarks (gamess and dealII failed, at -O2, not sure why) compiled with and without this option and did not see any real difference between respective run-times" Hopefully the default will be changed in newer gccs, but let's force it for kernel builds so that we are on a safe side even when older gcc are used. The code in question was out-of-tree printk-in-NMI (yeah, surprise suprise, once again) patch written by Petr Mladek, let me quote his comment from our internal bugzilla: "I have spent few days investigating inconsistent state of kernel ring buffer. It went out that it was caused by speculative store generated by gcc-4.3.4. The problem is in assembly generated for make_free_space(). The functions is called the following way: + vprintk_emit(); + log = MAIN_LOG; // with logbuf_lock or log = NMI_LOG; // with nmi_logbuf_lock cont_add(log, ...); + cont_flush(log, ...); + log_store(log, ...); + log_make_free_space(log, ...); If called with log = NMI_LOG then only nmi_log_* global variables are safe to modify but the generated code does store also into (main_)log_* global variables: <log_make_free_space>: 55 push %rbp 89 f6 mov %esi,%esi 48 8b 05 03 99 51 01 mov 0x1519903(%rip),%rax # ffffffff82620868 <nmi_log_next_id> 44 8b 1d ec 98 51 01 mov 0x15198ec(%rip),%r11d # ffffffff82620858 <log_next_idx> 8b 35 36 60 14 01 mov 0x1146036(%rip),%esi # ffffffff8224cfa8 <log_buf_len> 44 8b 35 33 60 14 01 mov 0x1146033(%rip),%r14d # ffffffff8224cfac <nmi_log_buf_len> 4c 8b 2d d0 98 51 01 mov 0x15198d0(%rip),%r13 # ffffffff82620850 <log_next_seq> 4c 8b 25 11 61 14 01 mov 0x1146111(%rip),%r12 # ffffffff8224d098 <log_buf> 49 89 c2 mov %rax,%r10 48 21 c2 and %rax,%rdx 48 8b 1d 0c 99 55 01 mov 0x155990c(%rip),%rbx # ffffffff826608a0 <nmi_log_buf> 49 c1 ea 20 shr $0x20,%r10 48 89 55 d0 mov %rdx,-0x30(%rbp) 44 29 de sub %r11d,%esi 45 29 d6 sub %r10d,%r14d 4c 8b 0d 97 98 51 01 mov 0x1519897(%rip),%r9 # ffffffff82620840 <log_first_seq> eb 7e jmp ffffffff81107029 <log_make_free_space+0xe9> [...] 85 ff test %edi,%edi # edi = 1 for NMI_LOG 4c 89 e8 mov %r13,%rax 4c 89 ca mov %r9,%rdx 74 0a je ffffffff8110703d <log_make_free_space+0xfd> 8b 15 27 98 51 01 mov 0x1519827(%rip),%edx # ffffffff82620860 <nmi_log_first_id> 48 8b 45 d0 mov -0x30(%rbp),%rax 48 39 c2 cmp %rax,%rdx # end of loop 0f 84 da 00 00 00 je ffffffff81107120 <log_make_free_space+0x1e0> [...] 85 ff test %edi,%edi # edi = 1 for NMI_LOG 4c 89 0d 17 97 51 01 mov %r9,0x1519717(%rip) # ffffffff82620840 <log_first_seq> ^^^^^^^^^^^^^^^^^^^^^^^^^^ KABOOOM 74 35 je ffffffff81107160 <log_make_free_space+0x220> It stores log_first_seq when edi == NMI_LOG. This instructions are used also when edi == MAIN_LOG but the store is done speculatively before the condition is decided. It is unsafe because we do not have "logbuf_lock" in NMI context and some other process migh modify "log_first_seq" in parallel" I believe that the best course of action is both - building kernel (and anything multi-threaded, I guess) with that optimization turned off - persuade gcc folks to change the default for future releases Signed-off-by: Jiri Kosina <jkosina@suse.cz> Cc: Martin Jambor <mjambor@suse.cz> Cc: Petr Mladek <pmladek@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Marek Polacek <polacek@redhat.com> Cc: Jakub Jelinek <jakub@redhat.com> Cc: Steven Noonan <steven@uplinklabs.net> Cc: Richard Biener <richard.guenther@gmail.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-07 01:08:43 +02:00
# Tell gcc to never replace conditional load with a non-conditional one
KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
include scripts/Makefile.kcov
GCC plugin infrastructure This patch allows to build the whole kernel with GCC plugins. It was ported from grsecurity/PaX. The infrastructure supports building out-of-tree modules and building in a separate directory. Cross-compilation is supported too. Currently the x86, arm, arm64 and uml architectures enable plugins. The directory of the gcc plugins is scripts/gcc-plugins. You can use a file or a directory there. The plugins compile with these options: * -fno-rtti: gcc is compiled with this option so the plugins must use it too * -fno-exceptions: this is inherited from gcc too * -fasynchronous-unwind-tables: this is inherited from gcc too * -ggdb: it is useful for debugging a plugin (better backtrace on internal errors) * -Wno-narrowing: to suppress warnings from gcc headers (ipa-utils.h) * -Wno-unused-variable: to suppress warnings from gcc headers (gcc_version variable, plugin-version.h) The infrastructure introduces a new Makefile target called gcc-plugins. It supports all gcc versions from 4.5 to 6.0. The scripts/gcc-plugin.sh script chooses the proper host compiler (gcc-4.7 can be built by either gcc or g++). This script also checks the availability of the included headers in scripts/gcc-plugins/gcc-common.h. The gcc-common.h header contains frequently included headers for GCC plugins and it has a compatibility layer for the supported gcc versions. The gcc-generate-*-pass.h headers automatically generate the registration structures for GIMPLE, SIMPLE_IPA, IPA and RTL passes. Note that 'make clean' keeps the *.so files (only the distclean or mrproper targets clean all) because they are needed for out-of-tree modules. Based on work created by the PaX Team. Signed-off-by: Emese Revfy <re.emese@gmail.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-05-24 00:09:38 +02:00
include scripts/Makefile.gcc-plugins
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,) \
$(call cc-option,-fno-partial-inlining)
endif
ifneq ($(CONFIG_FRAME_WARN),0)
KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
endif
stackp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector
Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables The changes to automatically test for working stack protector compiler support in the Kconfig files removed the special STACKPROTECTOR_AUTO option that picked the strongest stack protector that the compiler supported. That was all a nice cleanup - it makes no sense to have the AUTO case now that the Kconfig phase can just determine the compiler support directly. HOWEVER. It also meant that doing "make oldconfig" would now _disable_ the strong stackprotector if you had AUTO enabled, because in a legacy config file, the sane stack protector configuration would look like CONFIG_HAVE_CC_STACKPROTECTOR=y # CONFIG_CC_STACKPROTECTOR_NONE is not set # CONFIG_CC_STACKPROTECTOR_REGULAR is not set # CONFIG_CC_STACKPROTECTOR_STRONG is not set CONFIG_CC_STACKPROTECTOR_AUTO=y and when you ran this through "make oldconfig" with the Kbuild changes, it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version used to be disabled (because it was really enabled by AUTO), and would disable it in the new config, resulting in: CONFIG_HAVE_CC_STACKPROTECTOR=y CONFIG_CC_HAS_STACKPROTECTOR_NONE=y CONFIG_CC_STACKPROTECTOR=y # CONFIG_CC_STACKPROTECTOR_STRONG is not set CONFIG_CC_HAS_SANE_STACKPROTECTOR=y That's dangerously subtle - people could suddenly find themselves with the weaker stack protector setup without even realizing. The solution here is to just rename not just the old RECULAR stack protector option, but also the strong one. This does that by just removing the CC_ prefix entirely for the user choices, because it really is not about the compiler support (the compiler support now instead automatially impacts _visibility_ of the options to users). This results in "make oldconfig" actually asking the user for their choice, so that we don't have any silent subtle security model changes. The end result would generally look like this: CONFIG_HAVE_CC_STACKPROTECTOR=y CONFIG_CC_HAS_STACKPROTECTOR_NONE=y CONFIG_STACKPROTECTOR=y CONFIG_STACKPROTECTOR_STRONG=y CONFIG_CC_HAS_SANE_STACKPROTECTOR=y where the "CC_" versions really are about internal compiler infrastructure, not the user selections. Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-14 05:21:18 +02:00
stackp-flags-$(CONFIG_STACKPROTECTOR) := -fstack-protector
stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong
KBUILD_CFLAGS += $(stackp-flags-y)
ifdef CONFIG_CC_IS_CLANG
KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
# Quiet clang warning: comparison of unsigned expression < 0 is always false
KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
# 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 += $(call cc-option, -mno-global-merge,)
KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
else
# These warnings generated too much noise in a regular build.
# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
KBUILD_CFLAGS += -Wno-unused-but-set-variable
endif
KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
ifdef CONFIG_FRAME_POINTER
KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
else
# Some targets (ARM with Thumb2, for example), can't be built with frame
# pointers. For those, we don't have FUNCTION_TRACER automatically
# select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
# incompatible with -fomit-frame-pointer with current GCC, so we don't use
# -fomit-frame-pointer with FUNCTION_TRACER.
ifndef CONFIG_FUNCTION_TRACER
KBUILD_CFLAGS += -fomit-frame-pointer
endif
endif
Fix gcc-4.9.0 miscompilation of load_balance() in scheduler Michel Dänzer and a couple of other people reported inexplicable random oopses in the scheduler, and the cause turns out to be gcc mis-compiling the load_balance() function when debugging is enabled. The gcc bug apparently goes back to gcc-4.5, but slight optimization changes means that it now showed up as a problem in 4.9.0 and 4.9.1. The instruction scheduling problem causes gcc to schedule a spill operation to before the stack frame has been created, which in turn can corrupt the spilled value if an interrupt comes in. There may be other effects of this bug too, but that's the code generation problem seen in Michel's case. This is fixed in current gcc HEAD, but the workaround as suggested by Markus Trippelsdorf is pretty simple: use -fno-var-tracking-assignments when compiling the kernel, which disables the gcc code that causes the problem. This can result in slightly worse debug information for variable accesses, but that is infinitely preferable to actual code generation problems. Doing this unconditionally (not just for CONFIG_DEBUG_INFO) also allows non-debug builds to verify that the debug build would be identical: we can do export GCC_COMPARE_DEBUG=1 to make gcc internally verify that the result of the build is independent of the "-g" flag (it will make the compiler build everything twice, toggling the debug flag, and compare the results). Without the "-fno-var-tracking-assignments" option, the build would fail (even with 4.8.3 that didn't show the actual stack frame bug) with a gcc compare failure. See also gcc bugzilla: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61801 Reported-by: Michel Dänzer <michel@daenzer.net> Suggested-by: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Jakub Jelinek <jakub@redhat.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-07-26 23:52:01 +02:00
KBUILD_CFLAGS += $(call cc-option, -fno-var-tracking-assignments)
ifdef CONFIG_DEBUG_INFO
kbuild: Support split debug info v4 This is an alternative approach to lower the overhead of debug info (as we discussed a few days ago) gcc 4.7+ and newer binutils have a new "split debug info" debug info model where the debug info is only written once into central ".dwo" files. This avoids having to copy it around multiple times, from the object files to the final executable. It lowers the disk space requirements. In addition it defaults to compressed debug data. More details here: http://gcc.gnu.org/wiki/DebugFission This patch adds a new option to enable it. It has to be an option, because it'll undoubtedly break everyone's debuginfo packaging scheme. gdb/objdump/etc. all still work, if you have new enough versions. I don't see big compile wins (maybe a second or two faster or so), but the object dirs with debuginfo get significantly smaller. My standard kernel config (slightly bigger than defconfig) shrinks from 2.9G disk space to 1.1G objdir (with non reduced debuginfo). I presume if you are IO limited the compile time difference will be larger. Only problem I've seen so far is that it doesn't play well with older versions of ccache (apparently fixed, see https://bugzilla.samba.org/show_bug.cgi?id=10005) v2: various fixes from Dirk Gouders. Improve commit message slightly. v3: Fix clean rules and improve Kconfig slightly v4: Fix merge error in last version (Sam Ravnborg) Clarify description that it mainly helps disk size. Cc: Dirk Gouders <dirk@gouders.net> Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-07-30 20:50:18 +02:00
ifdef CONFIG_DEBUG_INFO_SPLIT
KBUILD_CFLAGS += $(call cc-option, -gsplit-dwarf, -g)
else
KBUILD_CFLAGS += -g
kbuild: Support split debug info v4 This is an alternative approach to lower the overhead of debug info (as we discussed a few days ago) gcc 4.7+ and newer binutils have a new "split debug info" debug info model where the debug info is only written once into central ".dwo" files. This avoids having to copy it around multiple times, from the object files to the final executable. It lowers the disk space requirements. In addition it defaults to compressed debug data. More details here: http://gcc.gnu.org/wiki/DebugFission This patch adds a new option to enable it. It has to be an option, because it'll undoubtedly break everyone's debuginfo packaging scheme. gdb/objdump/etc. all still work, if you have new enough versions. I don't see big compile wins (maybe a second or two faster or so), but the object dirs with debuginfo get significantly smaller. My standard kernel config (slightly bigger than defconfig) shrinks from 2.9G disk space to 1.1G objdir (with non reduced debuginfo). I presume if you are IO limited the compile time difference will be larger. Only problem I've seen so far is that it doesn't play well with older versions of ccache (apparently fixed, see https://bugzilla.samba.org/show_bug.cgi?id=10005) v2: various fixes from Dirk Gouders. Improve commit message slightly. v3: Fix clean rules and improve Kconfig slightly v4: Fix merge error in last version (Sam Ravnborg) Clarify description that it mainly helps disk size. Cc: Dirk Gouders <dirk@gouders.net> Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-07-30 20:50:18 +02:00
endif
KBUILD_AFLAGS += -Wa,-gdwarf-2
endif
ifdef CONFIG_DEBUG_INFO_DWARF4
KBUILD_CFLAGS += $(call cc-option, -gdwarf-4,)
endif
ifdef CONFIG_DEBUG_INFO_REDUCED
KBUILD_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
$(call cc-option,-fno-var-tracking)
endif
ifdef CONFIG_FUNCTION_TRACER
ifdef CONFIG_FTRACE_MCOUNT_RECORD
# gcc 5 supports generating the mcount tables directly
ifeq ($(call cc-option-yn,-mrecord-mcount),y)
CC_FLAGS_FTRACE += -mrecord-mcount
export CC_USING_RECORD_MCOUNT := 1
endif
ifdef CONFIG_HAVE_NOP_MCOUNT
ifeq ($(call cc-option-yn, -mnop-mcount),y)
CC_FLAGS_FTRACE += -mnop-mcount
CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
endif
endif
endif
ifdef CONFIG_HAVE_FENTRY
ifeq ($(call cc-option-yn, -mfentry),y)
CC_FLAGS_FTRACE += -mfentry
CC_FLAGS_USING += -DCC_USING_FENTRY
endif
endif
export CC_FLAGS_FTRACE
KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
KBUILD_AFLAGS += $(CC_FLAGS_USING)
ifdef CONFIG_DYNAMIC_FTRACE
ifdef CONFIG_HAVE_C_RECORDMCOUNT
BUILD_C_RECORDMCOUNT := y
export BUILD_C_RECORDMCOUNT
endif
endif
endif
# We trigger additional mismatches with less inlining
ifdef CONFIG_DEBUG_SECTION_MISMATCH
KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
endif
ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
LDFLAGS_vmlinux += --gc-sections
endif
# arch Makefile may override CC so keep this after arch Makefile is included
NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
# warn about C99 declaration after statement
KBUILD_CFLAGS += -Wdeclaration-after-statement
# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
KBUILD_CFLAGS += $(call cc-option,-Wvla)
# disable pointer signed / unsigned warnings in gcc 4.0
KBUILD_CFLAGS += -Wno-pointer-sign
# disable stringop warnings in gcc 8+
KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
# disable invalid "can't wrap" optimizations for signed / pointers
KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
kbuild: disable clang's default use of -fmerge-all-constants Prasad reported that he has seen crashes in BPF subsystem with netd on Android with arm64 in the form of (note, the taint is unrelated): [ 4134.721483] Unable to handle kernel paging request at virtual address 800000001 [ 4134.820925] Mem abort info: [ 4134.901283] Exception class = DABT (current EL), IL = 32 bits [ 4135.016736] SET = 0, FnV = 0 [ 4135.119820] EA = 0, S1PTW = 0 [ 4135.201431] Data abort info: [ 4135.301388] ISV = 0, ISS = 0x00000021 [ 4135.359599] CM = 0, WnR = 0 [ 4135.470873] user pgtable: 4k pages, 39-bit VAs, pgd = ffffffe39b946000 [ 4135.499757] [0000000800000001] *pgd=0000000000000000, *pud=0000000000000000 [ 4135.660725] Internal error: Oops: 96000021 [#1] PREEMPT SMP [ 4135.674610] Modules linked in: [ 4135.682883] CPU: 5 PID: 1260 Comm: netd Tainted: G S W 4.14.19+ #1 [ 4135.716188] task: ffffffe39f4aa380 task.stack: ffffff801d4e0000 [ 4135.731599] PC is at bpf_prog_add+0x20/0x68 [ 4135.741746] LR is at bpf_prog_inc+0x20/0x2c [ 4135.751788] pc : [<ffffff94ab7ad584>] lr : [<ffffff94ab7ad638>] pstate: 60400145 [ 4135.769062] sp : ffffff801d4e3ce0 [...] [ 4136.258315] Process netd (pid: 1260, stack limit = 0xffffff801d4e0000) [ 4136.273746] Call trace: [...] [ 4136.442494] 3ca0: ffffff94ab7ad584 0000000060400145 ffffffe3a01bf8f8 0000000000000006 [ 4136.460936] 3cc0: 0000008000000000 ffffff94ab844204 ffffff801d4e3cf0 ffffff94ab7ad584 [ 4136.479241] [<ffffff94ab7ad584>] bpf_prog_add+0x20/0x68 [ 4136.491767] [<ffffff94ab7ad638>] bpf_prog_inc+0x20/0x2c [ 4136.504536] [<ffffff94ab7b5d08>] bpf_obj_get_user+0x204/0x22c [ 4136.518746] [<ffffff94ab7ade68>] SyS_bpf+0x5a8/0x1a88 Android's netd was basically pinning the uid cookie BPF map in BPF fs (/sys/fs/bpf/traffic_cookie_uid_map) and later on retrieving it again resulting in above panic. Issue is that the map was wrongly identified as a prog! Above kernel was compiled with clang 4.0, and it turns out that clang decided to merge the bpf_prog_iops and bpf_map_iops into a single memory location, such that the two i_ops could then not be distinguished anymore. Reason for this miscompilation is that clang has the more aggressive -fmerge-all-constants enabled by default. In fact, clang source code has a comment about it in lib/AST/ExprConstant.cpp on why it is okay to do so: Pointers with different bases cannot represent the same object. (Note that clang defaults to -fmerge-all-constants, which can lead to inconsistent results for comparisons involving the address of a constant; this generally doesn't matter in practice.) The issue never appeared with gcc however, since gcc does not enable -fmerge-all-constants by default and even *explicitly* states in it's option description that using this flag results in non-conforming behavior, quote from man gcc: Languages like C or C++ require each variable, including multiple instances of the same variable in recursive calls, to have distinct locations, so using this option results in non-conforming behavior. There are also various clang bug reports open on that matter [1], where clang developers acknowledge the non-conforming behavior, and refer to disabling it with -fno-merge-all-constants. But even if this gets fixed in clang today, there are already users out there that triggered this. Thus, fix this issue by explicitly adding -fno-merge-all-constants to the kernel's Makefile to generically disable this optimization, since potentially other places in the kernel could subtly break as well. Note, there is also a flag called -fmerge-constants (not supported by clang), which is more conservative and only applies to strings and it's enabled in gcc's -O/-O2/-O3/-Os optimization levels. In gcc's code, the two flags -fmerge-{all-,}constants share the same variable internally, so when disabling it via -fno-merge-all-constants, then we really don't merge any const data (e.g. strings), and text size increases with gcc (14,927,214 -> 14,942,646 for vmlinux.o). $ gcc -fverbose-asm -O2 foo.c -S -o foo.S -> foo.S lists -fmerge-constants under options enabled $ gcc -fverbose-asm -O2 -fno-merge-all-constants foo.c -S -o foo.S -> foo.S doesn't list -fmerge-constants under options enabled $ gcc -fverbose-asm -O2 -fno-merge-all-constants -fmerge-constants foo.c -S -o foo.S -> foo.S lists -fmerge-constants under options enabled Thus, as a workaround we need to set both -fno-merge-all-constants *and* -fmerge-constants in the Makefile in order for text size to stay as is. [1] https://bugs.llvm.org/show_bug.cgi?id=18538 Reported-by: Prasad Sodagudi <psodagud@codeaurora.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Chenbo Feng <fengc@google.com> Cc: Richard Smith <richard-llvm@metafoo.co.uk> Cc: Chandler Carruth <chandlerc@gmail.com> Cc: linux-kernel@vger.kernel.org Tested-by: Prasad Sodagudi <psodagud@codeaurora.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-03-21 01:18:24 +01:00
# clang sets -fmerge-all-constants by default as optimization, but this
# is non-conforming behavior for C and in fact breaks the kernel, so we
# need to disable it here generally.
KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants)
# for gcc -fno-merge-all-constants disables everything, but it is fine
# to have actual conforming behavior enabled.
KBUILD_CFLAGS += $(call cc-option,-fmerge-constants)
# Make sure -fstack-check isn't enabled (like gentoo apparently did)
KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,)
# conserve stack if available
KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
# Prohibit date/time macros, which would make the build non-deterministic
KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
# enforce correct pointer usage
KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
# Require designated initializers for all marked structures
KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
# change __FILE__ to the relative path from the srctree
KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
# use the deterministic mode of AR if available
KBUILD_ARFLAGS := $(call ar-option,D)
include scripts/Makefile.kasan
include scripts/Makefile.extrawarn
UBSAN: run-time undefined behavior sanity checker UBSAN uses compile-time instrumentation to catch undefined behavior (UB). Compiler inserts code that perform certain kinds of checks before operations that could cause UB. If check fails (i.e. UB detected) __ubsan_handle_* function called to print error message. So the most of the work is done by compiler. This patch just implements ubsan handlers printing errors. GCC has this capability since 4.9.x [1] (see -fsanitize=undefined option and its suboptions). However GCC 5.x has more checkers implemented [2]. Article [3] has a bit more details about UBSAN in the GCC. [1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html [2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html [3] - http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/ Issues which UBSAN has found thus far are: Found bugs: * out-of-bounds access - 97840cb67ff5 ("netfilter: nfnetlink: fix insufficient validation in nfnetlink_bind") undefined shifts: * d48458d4a768 ("jbd2: use a better hash function for the revoke table") * 10632008b9e1 ("clockevents: Prevent shift out of bounds") * 'x << -1' shift in ext4 - http://lkml.kernel.org/r/<5444EF21.8020501@samsung.com> * undefined rol32(0) - http://lkml.kernel.org/r/<1449198241-20654-1-git-send-email-sasha.levin@oracle.com> * undefined dirty_ratelimit calculation - http://lkml.kernel.org/r/<566594E2.3050306@odin.com> * undefined roundown_pow_of_two(0) - http://lkml.kernel.org/r/<1449156616-11474-1-git-send-email-sasha.levin@oracle.com> * [WONTFIX] undefined shift in __bpf_prog_run - http://lkml.kernel.org/r/<CACT4Y+ZxoR3UjLgcNdUm4fECLMx2VdtfrENMtRRCdgHB2n0bJA@mail.gmail.com> WONTFIX here because it should be fixed in bpf program, not in kernel. signed overflows: * 32a8df4e0b33f ("sched: Fix odd values in effective_load() calculations") * mul overflow in ntp - http://lkml.kernel.org/r/<1449175608-1146-1-git-send-email-sasha.levin@oracle.com> * incorrect conversion into rtc_time in rtc_time64_to_tm() - http://lkml.kernel.org/r/<1449187944-11730-1-git-send-email-sasha.levin@oracle.com> * unvalidated timespec in io_getevents() - http://lkml.kernel.org/r/<CACT4Y+bBxVYLQ6LtOKrKtnLthqLHcw-BMp3aqP3mjdAvr9FULQ@mail.gmail.com> * [NOTABUG] signed overflow in ktime_add_safe() - http://lkml.kernel.org/r/<CACT4Y+aJ4muRnWxsUe1CMnA6P8nooO33kwG-c8YZg=0Xc8rJqw@mail.gmail.com> [akpm@linux-foundation.org: fix unused local warning] [akpm@linux-foundation.org: fix __int128 build woes] Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Marek <mmarek@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Yury Gribov <y.gribov@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21 00:00:55 +01:00
include scripts/Makefile.ubsan
# Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
# last assignments
KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS)
KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS)
# Use --build-id when available.
LDFLAGS_BUILD_ID := $(call ld-option, --build-id)
kbuild: allow assignment to {A,C,LD}FLAGS_MODULE on the command line It is now possible to assign options to AS, CC and LD on the command line - which is only used when building modules. {A,C,LD}FLAGS_MODULE was all used both in the top-level Makefile in the arch makefiles, thus users had no way to specify additional options to AS, CC, LD when building modules without overriding the original value. Introduce a new set of variables KBUILD_{A,C,LD}FLAGS_MODULE that is used by arch specific files and free up {A,C,LD}FLAGS_MODULE so they can be assigned on the command line. All arch Makefiles that used the old variables has been updated. Note: Previously we had a MODFLAGS variable for both AS and CC. But in favour of consistency this was dropped. So in some cases arch Makefile has one assignmnet replaced by two assignmnets. Note2: MODFLAGS was not documented and is dropped without any notice. I do not expect much/any breakage from this. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Denys Vlasenko <vda.linux@googlemail.com> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Chen Liqin <liqin.chen@sunplusct.com> Acked-by: Mike Frysinger <vapier@gentoo.org> [blackfin] Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> [avr32] Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-07-28 17:33:09 +02:00
KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
LDFLAGS_vmlinux += $(call ld-option, -X,)
endif
# insure the checker run with the right endianness
CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
# the checker needs the correct machine size
CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
# Default kernel image to build when no specific target is given.
# KBUILD_IMAGE may be overruled on the command line or
# set in the environment
# Also any assignments in arch/$(ARCH)/Makefile take precedence over
# this default value
export KBUILD_IMAGE ?= vmlinux
#
# INSTALL_PATH specifies where to place the updated kernel and system map
# images. Default is /boot, but you can set it to other values
export INSTALL_PATH ?= /boot
kbuild: dtbs_install: new make target Unlike other build products in the Linux kernel, there is no 'make *install' mechanism to put devicetree blobs in a standard place. This commit adds a new 'dtbs_install' make target which copies all of the dtbs into the INSTALL_DTBS_PATH directory. INSTALL_DTBS_PATH can be set before calling make to change the default install directory. If not set then it defaults to: $INSTALL_PATH/dtbs/$KERNELRELEASE. This is done to keep dtbs from different kernel versions separate until things have settled down. Once the dtbs are stable, and not so strongly linked to the kernel version, the devicetree files will most likely move to their own repo. Users will need to upgrade install scripts at that time. v7: (reworked by Grant Likely) - Moved rules from arch/arm/Makefile to arch/arm/boot/dts/Makefile so that each dtb install could have a separate target and be reported as part of the make output. - Fixed dependency problem to ensure $KERNELRELEASE is calculated before attempting to install - Removed option to call external script. Copying the files should be sufficient and a build system can post-process the install directory. Despite the fact an external script is used for installing the kernel, I don't think that is a pattern that should be encouraged. I would rather see buildroot type tools post process the install directory to rename or move dtb files after installing to a staging directory. - Plus it is easy to add a hook after the fact without blocking the rest of this feature. - Move the helper targets into scripts/Makefile.lib with the rest of the common dtb rules Signed-off-by: Jason Cooper <jason@lakedaemon.net> Signed-off-by: Grant Likely <grant.likely@linaro.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Russell King <linux@arm.linux.org.uk> Cc: Rob Herring <robh+dt@kernel.org>
2013-12-02 00:56:28 +01:00
#
# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
# an argument if needed. Otherwise it defaults to the kernel install path
#
export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
#
# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
# relocations required by build roots. This is not defined in the
# makefile but the argument can be passed to make if needed.
#
MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
export MODLIB
#
# INSTALL_MOD_STRIP, if defined, will cause modules to be
# stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
# the default option --strip-debug will be used. Otherwise,
# INSTALL_MOD_STRIP value will be used as the options to the strip command.
ifdef INSTALL_MOD_STRIP
ifeq ($(INSTALL_MOD_STRIP),1)
mod_strip_cmd = $(STRIP) --strip-debug
else
mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
endif # INSTALL_MOD_STRIP=1
else
mod_strip_cmd = true
endif # INSTALL_MOD_STRIP
export mod_strip_cmd
kbuild: handle module compression while running 'make modules_install'. Since module-init-tools (gzip) and kmod (gzip and xz) support compressed modules, it could be useful to include a support for compressing modules right after having them installed. Doing this in kbuild instead of per distro can permit to make this kind of usage more generic. This patch add a Kconfig entry to "Enable loadable module support" menu and let you choose to compress using gzip (default) or xz. Both gzip and xz does not used any extra -[1-9] option since Andi Kleen and Rusty Russell prove no gain is made using them. gzip is called with -n argument to avoid storing original filename inside compressed file, that way we can save some more bytes. On a v3.16 kernel, 'make allmodconfig' generated 4680 modules for a total of 378MB (no strip, no sign, no compress), the following table shows observed disk space gain based on the allmodconfig .config : | time | +-------------+-----------------+ | manual .ko | make | size | percent | compression | modules_install | | gain +-------------+-----------------+------+-------- - | | 18.61s | 378M | GZIP | 3m16s | 3m37s | 102M | 73.41% XZ | 5m22s | 5m39s | 77M | 79.83% The gain for restricted environnement seems to be interesting while uncompress can be time consuming but happens only while loading a module, that is generally done only once. This is fully compatible with signed modules while the signed module is compressed. module-init-tools or kmod handles decompression and provide to other layer the uncompressed but signed payload. Reviewed-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Bertrand Jacquin <beber@meleeweb.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-08-27 13:01:56 +02:00
# CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
# after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
# or CONFIG_MODULE_COMPRESS_XZ.
mod_compress_cmd = true
ifdef CONFIG_MODULE_COMPRESS
ifdef CONFIG_MODULE_COMPRESS_GZIP
mod_compress_cmd = gzip -n -f
kbuild: handle module compression while running 'make modules_install'. Since module-init-tools (gzip) and kmod (gzip and xz) support compressed modules, it could be useful to include a support for compressing modules right after having them installed. Doing this in kbuild instead of per distro can permit to make this kind of usage more generic. This patch add a Kconfig entry to "Enable loadable module support" menu and let you choose to compress using gzip (default) or xz. Both gzip and xz does not used any extra -[1-9] option since Andi Kleen and Rusty Russell prove no gain is made using them. gzip is called with -n argument to avoid storing original filename inside compressed file, that way we can save some more bytes. On a v3.16 kernel, 'make allmodconfig' generated 4680 modules for a total of 378MB (no strip, no sign, no compress), the following table shows observed disk space gain based on the allmodconfig .config : | time | +-------------+-----------------+ | manual .ko | make | size | percent | compression | modules_install | | gain +-------------+-----------------+------+-------- - | | 18.61s | 378M | GZIP | 3m16s | 3m37s | 102M | 73.41% XZ | 5m22s | 5m39s | 77M | 79.83% The gain for restricted environnement seems to be interesting while uncompress can be time consuming but happens only while loading a module, that is generally done only once. This is fully compatible with signed modules while the signed module is compressed. module-init-tools or kmod handles decompression and provide to other layer the uncompressed but signed payload. Reviewed-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Bertrand Jacquin <beber@meleeweb.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-08-27 13:01:56 +02:00
endif # CONFIG_MODULE_COMPRESS_GZIP
ifdef CONFIG_MODULE_COMPRESS_XZ
mod_compress_cmd = xz -f
kbuild: handle module compression while running 'make modules_install'. Since module-init-tools (gzip) and kmod (gzip and xz) support compressed modules, it could be useful to include a support for compressing modules right after having them installed. Doing this in kbuild instead of per distro can permit to make this kind of usage more generic. This patch add a Kconfig entry to "Enable loadable module support" menu and let you choose to compress using gzip (default) or xz. Both gzip and xz does not used any extra -[1-9] option since Andi Kleen and Rusty Russell prove no gain is made using them. gzip is called with -n argument to avoid storing original filename inside compressed file, that way we can save some more bytes. On a v3.16 kernel, 'make allmodconfig' generated 4680 modules for a total of 378MB (no strip, no sign, no compress), the following table shows observed disk space gain based on the allmodconfig .config : | time | +-------------+-----------------+ | manual .ko | make | size | percent | compression | modules_install | | gain +-------------+-----------------+------+-------- - | | 18.61s | 378M | GZIP | 3m16s | 3m37s | 102M | 73.41% XZ | 5m22s | 5m39s | 77M | 79.83% The gain for restricted environnement seems to be interesting while uncompress can be time consuming but happens only while loading a module, that is generally done only once. This is fully compatible with signed modules while the signed module is compressed. module-init-tools or kmod handles decompression and provide to other layer the uncompressed but signed payload. Reviewed-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Bertrand Jacquin <beber@meleeweb.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-08-27 13:01:56 +02:00
endif # CONFIG_MODULE_COMPRESS_XZ
endif # CONFIG_MODULE_COMPRESS
export mod_compress_cmd
# Select initial ramdisk compression format, default is gzip(1).
# This shall be used by the dracut(8) tool while creating an initramfs image.
#
INITRD_COMPRESS-y := gzip
INITRD_COMPRESS-$(CONFIG_RD_BZIP2) := bzip2
INITRD_COMPRESS-$(CONFIG_RD_LZMA) := lzma
INITRD_COMPRESS-$(CONFIG_RD_XZ) := xz
INITRD_COMPRESS-$(CONFIG_RD_LZO) := lzo
INITRD_COMPRESS-$(CONFIG_RD_LZ4) := lz4
# do not export INITRD_COMPRESS, since we didn't actually
# choose a sane default compression above.
# export INITRD_COMPRESS := $(INITRD_COMPRESS-y)
ifdef CONFIG_MODULE_SIG_ALL
$(eval $(call config_filename,MODULE_SIG_KEY))
mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
else
mod_sign_cmd = true
endif
export mod_sign_cmd
ifdef CONFIG_STACK_VALIDATION
has_libelf := $(call try-run,\
echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0)
ifeq ($(has_libelf),1)
objtool_target := tools/objtool FORCE
else
SKIP_STACK_VALIDATION := 1
export SKIP_STACK_VALIDATION
endif
endif
ifeq ($(KBUILD_EXTMOD),)
core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
$(core-y) $(core-m) $(drivers-y) $(drivers-m) \
$(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
$(init-) $(core-) $(drivers-) $(net-) $(libs-) $(virt-))))
init-y := $(patsubst %/, %/built-in.a, $(init-y))
core-y := $(patsubst %/, %/built-in.a, $(core-y))
drivers-y := $(patsubst %/, %/built-in.a, $(drivers-y))
net-y := $(patsubst %/, %/built-in.a, $(net-y))
libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))
virt-y := $(patsubst %/, %/built-in.a, $(virt-y))
# Externally visible symbols (used by link-vmlinux.sh)
export KBUILD_VMLINUX_INIT := $(head-y) $(init-y)
export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y2) $(drivers-y) $(net-y) $(virt-y)
export KBUILD_VMLINUX_LIBS := $(libs-y1)
export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
export LDFLAGS_vmlinux
# used by scripts/package/Makefile
export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools)
vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_INIT) $(KBUILD_VMLINUX_MAIN) $(KBUILD_VMLINUX_LIBS)
kbuild: link vmlinux only once for CONFIG_TRIM_UNUSED_KSYMS If CONFIG_TRIM_UNUSED_KSYMS is enabled and the kernel is built from a pristine state, the vmlinux is linked twice. [1] A user runs 'make' [2] First build with empty autoksyms.h [3] adjust_autoksyms.sh updates autoksyms.h and recurses 'make vmlinux' --------(begin sub-make)-------- [4] Second build with new autoksyms.h [5] link-vmlinux.sh is invoked because vmlinux is missing ---------(end sub-make)--------- [6] link-vmlinux.sh is invoked again despite vmlinux is up-to-date. The reason of [6] is probably because Make already decided to update vmlinux at the time of [2] because vmlinux was missing when Make built up the dependency graph. Because if_changed is implemented based on $?, this issue can be narrowed down to how Make handles $?. You can test it with the following simple code: [Test Makefile] A: B @echo newer prerequisite: $? cp B A B: C cp C B touch A [Result] $ rm -f A B $ touch C $ make cp C B touch A newer prerequisite: B cp B A Here, 'A' has been touched in the recipe of 'B'. So, the dependency 'A: B' has already been met before the recipe of 'A' is executed. However, Make does not notice the fact that the recipe of 'B' also updates 'A' as a side-effect. The situation is similar in this case; the vmlinux has actually been updated in the vmlinux_prereq target. Make cannot predict this, so judges the vmlinux is old. link-vmlinux.sh is costly, so it is better to not run it when unneeded. Split CONFIG_TRIM_UNUSED_KSYMS recursion to a dedicated target. The reason of commit 2441e78b1919 ("kbuild: better abstract vmlinux sequential prerequisites") was to cater to CONFIG_BUILD_DOCSRC, but it was later removed by commit 184892925118 ("samples: move blackfin gptimers-example from Documentation"). Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Nicolas Pitre <nico@linaro.org>
2018-03-16 08:37:15 +01:00
# Recurse until adjust_autoksyms.sh is satisfied
PHONY += autoksyms_recursive
autoksyms_recursive: $(vmlinux-deps)
ifdef CONFIG_TRIM_UNUSED_KSYMS
$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
"$(MAKE) -f $(srctree)/Makefile vmlinux"
endif
# For the kernel to actually contain only the needed exported symbols,
# we have to build modules as well to determine what those symbols are.
# (this can be evaluated only once include/config/auto.conf has been included)
ifdef CONFIG_TRIM_UNUSED_KSYMS
KBUILD_MODULES := 1
endif
kbuild: restore autoksyms.h touch to the top Makefile Commit d3fc425e819b ("kbuild: make sure autoksyms.h exists early") moved the code that touches autoksyms.h to scripts/kconfig/Makefile with obscure reason. From Nicolas' comment [1], he did not seem to be sure about the root cause. I guess I figured it out, so here is a fix-up I think is more correct. According to the error log in the original post [2], the build failed in scripts/mod/devicetable-offsets.c scripts/mod/Makefile is descended from scripts/Makefile, which is invoked from the top-level Makefile by the 'scripts' target. To build vmlinux and/or modules, Kbuild descend into $(vmlinux-dirs). This depends on 'prepare' and 'scripts' as follows: $(vmlinux-dirs): prepare scripts Because there is no dependency between 'prepare' and 'scripts', the parallel building can execute them simultaneously. 'prepare' depends on 'prepare1', which touched autoksyms.h, while 'scripts' descends into script/, then scripts/mod/, which needs <generated/autoksyms.h> if CONFIG_TRIM_UNUSED_KSYMS. It was the reason of the race. I am not happy to have unrelated code in the Kconfig Makefile, so getting it back to the top Makefile. I removed the standalone test target because I want to use it to create an empty autoksyms.h file. Here is a little improvement; unnecessary autoksyms.h is not created when CONFIG_TRIM_UNUSED_KSYMS is disabled. [1] https://lkml.org/lkml/2016/11/30/734 [2] https://lkml.org/lkml/2016/11/30/531 Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Nicolas Pitre <nico@linaro.org>
2018-03-16 08:37:12 +01:00
autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
$(autoksyms_h):
$(Q)mkdir -p $(dir $@)
$(Q)touch $@
ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
# Final link of vmlinux with optional arch pass after final link
cmd_link-vmlinux = \
$(CONFIG_SHELL) $< $(LD) $(KBUILD_LDFLAGS) $(LDFLAGS_vmlinux) ; \
$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
kbuild: link vmlinux only once for CONFIG_TRIM_UNUSED_KSYMS If CONFIG_TRIM_UNUSED_KSYMS is enabled and the kernel is built from a pristine state, the vmlinux is linked twice. [1] A user runs 'make' [2] First build with empty autoksyms.h [3] adjust_autoksyms.sh updates autoksyms.h and recurses 'make vmlinux' --------(begin sub-make)-------- [4] Second build with new autoksyms.h [5] link-vmlinux.sh is invoked because vmlinux is missing ---------(end sub-make)--------- [6] link-vmlinux.sh is invoked again despite vmlinux is up-to-date. The reason of [6] is probably because Make already decided to update vmlinux at the time of [2] because vmlinux was missing when Make built up the dependency graph. Because if_changed is implemented based on $?, this issue can be narrowed down to how Make handles $?. You can test it with the following simple code: [Test Makefile] A: B @echo newer prerequisite: $? cp B A B: C cp C B touch A [Result] $ rm -f A B $ touch C $ make cp C B touch A newer prerequisite: B cp B A Here, 'A' has been touched in the recipe of 'B'. So, the dependency 'A: B' has already been met before the recipe of 'A' is executed. However, Make does not notice the fact that the recipe of 'B' also updates 'A' as a side-effect. The situation is similar in this case; the vmlinux has actually been updated in the vmlinux_prereq target. Make cannot predict this, so judges the vmlinux is old. link-vmlinux.sh is costly, so it is better to not run it when unneeded. Split CONFIG_TRIM_UNUSED_KSYMS recursion to a dedicated target. The reason of commit 2441e78b1919 ("kbuild: better abstract vmlinux sequential prerequisites") was to cater to CONFIG_BUILD_DOCSRC, but it was later removed by commit 184892925118 ("samples: move blackfin gptimers-example from Documentation"). Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Nicolas Pitre <nico@linaro.org>
2018-03-16 08:37:15 +01:00
vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
ifdef CONFIG_GDB_SCRIPTS
$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
endif
+$(call if_changed,link-vmlinux)
kbuild: let fixdep directly write to .*.cmd files Currently, fixdep writes dependencies to .*.tmp, which is renamed to .*.cmd after everything succeeds. This is a very safe way to avoid corrupted .*.cmd files. The if_changed_dep has carried this safety mechanism since it was added in 2002. If fixdep fails for some reasons or a user terminates the build while fixdep is running, the incomplete output from the fixdep could be troublesome. This is my insight about some bad scenarios: [1] If the compiler succeeds to generate *.o file, but fixdep fails to write necessary dependencies to .*.cmd file, Make will miss to rebuild the object when headers or CONFIG options are changed. In this case, fixdep should not generate .*.cmd file at all so that 'arg-check' will surely trigger the rebuild of the object. [2] A partially constructed .*.cmd file may not be a syntactically correct makefile. The next time Make runs, it would include it, then fail to parse it. Once this happens, 'make clean' is be the only way to fix it. In fact, [1] is no longer a problem since commit 9c2af1c7377a ("kbuild: add .DELETE_ON_ERROR special target"). Make deletes a target file on any failure in its recipe. Because fixdep is a part of the recipe of *.o target, if it fails, the *.o is deleted anyway. However, I am a bit worried about the slight possibility of [2]. So, here is a solution. Let fixdep directly write to a .*.cmd file, but allow makefiles to include it only when its corresponding target exists. This effectively reverts commit 2982c953570b ("kbuild: remove redundant $(wildcard ...) for cmd_files calculation"), and commit 00d78ab2ba75 ("kbuild: remove dead code in cmd_files calculation in top Makefile") because now we must check the presence of targets. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-11-30 02:05:22 +01:00
targets := vmlinux
# Build samples along the rest of the kernel. This needs headers_install.
ifdef CONFIG_SAMPLES
vmlinux-dirs += samples
samples: headers_install
endif
# The actual objects are generated when descending,
# make sure no implicit rule kicks in
$(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
# Handle descending into subdirectories listed in $(vmlinux-dirs)
# Preset locale variables to speed up the build process. Limit locale
# tweaks to this spot to avoid wrong language settings when running
# make menuconfig etc.
# Error messages still appears in the original language
PHONY += $(vmlinux-dirs)
$(vmlinux-dirs): prepare
$(Q)$(MAKE) $(build)=$@ need-builtin=1
filechk_kernel.release = \
echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
# Store (new) KERNELRELEASE string in include/config/kernel.release
include/config/kernel.release: $(srctree)/Makefile FORCE
$(call filechk,kernel.release)
# Additional helpers built in scripts/
# Carefully list dependencies so we do not try to build scripts twice
# in parallel
PHONY += scripts
scripts: scripts_basic scripts_dtc
$(Q)$(MAKE) $(build)=$(@)
# Things we need to do before we recursively start building the kernel
# or the modules are listed in "prepare".
# A multi level approach is used. prepareN is processed before prepareN-1.
# archprepare is used in arch Makefiles and when processed asm symlink,
# version.h and scripts_basic is processed / created.
# Listed in dependency order
PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3
# prepare3 is used to check if we are building in a separate output directory,
# and if so do:
# 1) Check that make has not been executed in the kernel src $(srctree)
prepare3: include/config/kernel.release
ifneq ($(KBUILD_SRC),)
@$(kecho) ' Using $(srctree) as source for kernel'
$(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
echo >&2 " $(srctree) is not clean, please run 'make mrproper'"; \
echo >&2 " in the '$(srctree)' directory.";\
/bin/false; \
fi;
endif
# prepare2 creates a makefile if using a separate output directory.
# From this point forward, .config has been reprocessed, so any rules
# that need to depend on updated CONFIG_* values can be checked here.
prepare2: prepare3 outputmakefile asm-generic
prepare1: prepare2 $(version_h) $(autoksyms_h) include/generated/utsrelease.h
$(cmd_crmodverdir)
Kbuild updates for v4.21 Kbuild core: - remove unneeded $(call cc-option,...) switches - consolidate Clang compiler flags into CLANG_FLAGS - announce the deprecation of SUBDIRS - fix single target build for external module - simplify the dependencies of 'prepare' stage targets - allow fixdep to directly write to .*.cmd files - simplify dependency generation for CONFIG_TRIM_UNUSED_KSYMS - change if_changed_rule to accept multi-line recipe - move .SECONDARY special target to scripts/Kbuild.include - remove redundant 'set -e' - improve parallel execution for CONFIG_HEADERS_CHECK - misc cleanups Treewide fixes and cleanups - set Clang flags correctly for PowerPC boot images - fix UML build error with CONFIG_GCC_PLUGINS - remove unneeded patterns from .gitignore files - refactor firmware/Makefile - remove unneeded rules for *offsets.s - avoid unneeded regeneration of intermediate .s files - clean up ./Kbuild Modpost: - remove unused -M, -K options - fix false positive warnings about section mismatch - use simple devtable lookup instead of linker magic - misc cleanups Coccinelle: - relax boolinit.cocci checks for overall consistency - fix warning messages of boolinit.cocci Other tools: - improve -dirty check of scripts/setlocalversion - add a tool to generate compile_commands.json from .*.cmd files -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAABAgAGBQJcJiVeAAoJED2LAQed4NsGXEMP/1fdkBfZGxYlxp4w1tEBeRKZ GInxxMfHiHZlu7nFPQ3k1mncczZjeLbnKcLaybnPmqBSfQe1F7tN0ux1sHtWkVfI DvqoKaHObZ3lEMEVxCHXQ2bKrN/j9nB2xSxzr4dvc9DscW8dwKElZuKVE7nHKdhl z70xsalxHGEGY6hptJrucbv8KTBOSleZ8Gaat79sEDkDSLCTjxXB3WcVMWqDT0M/ IqN5QCwiPjZC3UCwuqq6+vnG1gyvDUORcbrVgHrBIKxLYAABYzugB5IlLpi8B31C ZUDmijSTandHd4SG5gw5uZoyYuK4YhZeI7g4yNyXSqnPurmcJxrGdpiuwRcE7xet 5yB2uaNbAFO6Fbz4gUdDEvryA9IZEPPn1Z0Btfpp7UOxiWEqE61oHReCNdkiad94 Oonl+ROZw5UOT3AZD3xCZTf9bTnQoCFccHTmnbaKqqSiDWxxLUXum7sNfnJ6GXEb fNQDuwuxtsPStaWoU93QNrGyl5e8jYTKFdphUCnZZ2/hE8ygoQ06PYmeBAk+UKfN UI2IqR8PHgmA97XJg+fHhbw6X4nQcPsg/usLqxGItAZNO2O4uXgaN24dOcHG74Bu 2Dk/gQQB2sVB/Dxfmlaxvvj98MVg7IMtpusAT2bQ7miiSS3EqPFT8KQMZYLICWuZ u7QQe20yCho3ZULmsRwH =0PCt -----END PGP SIGNATURE----- Merge tag 'kbuild-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: "Kbuild core: - remove unneeded $(call cc-option,...) switches - consolidate Clang compiler flags into CLANG_FLAGS - announce the deprecation of SUBDIRS - fix single target build for external module - simplify the dependencies of 'prepare' stage targets - allow fixdep to directly write to .*.cmd files - simplify dependency generation for CONFIG_TRIM_UNUSED_KSYMS - change if_changed_rule to accept multi-line recipe - move .SECONDARY special target to scripts/Kbuild.include - remove redundant 'set -e' - improve parallel execution for CONFIG_HEADERS_CHECK - misc cleanups Treewide fixes and cleanups - set Clang flags correctly for PowerPC boot images - fix UML build error with CONFIG_GCC_PLUGINS - remove unneeded patterns from .gitignore files - refactor firmware/Makefile - remove unneeded rules for *offsets.s - avoid unneeded regeneration of intermediate .s files - clean up ./Kbuild Modpost: - remove unused -M, -K options - fix false positive warnings about section mismatch - use simple devtable lookup instead of linker magic - misc cleanups Coccinelle: - relax boolinit.cocci checks for overall consistency - fix warning messages of boolinit.cocci Other tools: - improve -dirty check of scripts/setlocalversion - add a tool to generate compile_commands.json from .*.cmd files" * tag 'kbuild-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (51 commits) kbuild: remove unused cmd_gentimeconst kbuild: remove $(obj)/ prefixes in ./Kbuild treewide: add intermediate .s files to targets treewide: remove explicit rules for *offsets.s firmware: refactor firmware/Makefile firmware: remove unnecessary patterns from .gitignore scripts: remove unnecessary ihex2fw and check-lc_ctypes from .gitignore um: remove unused filechk_gen_header in Makefile scripts: add a tool to produce a compile_commands.json file kbuild: add -Werror=implicit-int flag unconditionally kbuild: add -Werror=strict-prototypes flag unconditionally kbuild: add -fno-PIE flag unconditionally scripts: coccinelle: Correct warning message scripts: coccinelle: only suggest true/false in files that already use them kbuild: handle part-of-module correctly for *.ll and *.symtypes kbuild: refactor part-of-module kbuild: refactor quiet_modtag kbuild: remove redundant quiet_modtag for $(obj-m) kbuild: refactor Makefile.asm-generic user/Makefile: Fix typo and capitalization in comment section ...
2018-12-29 21:03:17 +01:00
archprepare: archheaders archscripts prepare1 scripts
kbuild: fix UML build error with CONFIG_GCC_PLUGINS UML fails to build with CONFIG_GCC_PLUGINS=y. $ make -s ARCH=um mrproper $ make -s ARCH=um allmodconfig $ make ARCH=um UPD include/generated/uapi/linux/version.h WRAP arch/x86/include/generated/uapi/asm/bpf_perf_event.h WRAP arch/x86/include/generated/uapi/asm/poll.h WRAP arch/x86/include/generated/asm/dma-contiguous.h WRAP arch/x86/include/generated/asm/early_ioremap.h WRAP arch/x86/include/generated/asm/export.h WRAP arch/x86/include/generated/asm/mcs_spinlock.h WRAP arch/x86/include/generated/asm/mm-arch-hooks.h SYSTBL arch/x86/include/generated/asm/syscalls_32.h SYSHDR arch/x86/include/generated/asm/unistd_32_ia32.h SYSHDR arch/x86/include/generated/asm/unistd_64_x32.h SYSTBL arch/x86/include/generated/asm/syscalls_64.h SYSHDR arch/x86/include/generated/uapi/asm/unistd_32.h SYSHDR arch/x86/include/generated/uapi/asm/unistd_64.h SYSHDR arch/x86/include/generated/uapi/asm/unistd_x32.h HOSTCC scripts/unifdef CC arch/x86/um/user-offsets.s cc1: error: cannot load plugin ./scripts/gcc-plugins/cyc_complexity_plugin.so ./scripts/gcc-plugins/cyc_complexity_plugin.so: cannot open shared object file: No such file or directory cc1: error: cannot load plugin ./scripts/gcc-plugins/structleak_plugin.so ./scripts/gcc-plugins/structleak_plugin.so: cannot open shared object file: No such file or directory cc1: error: cannot load plugin ./scripts/gcc-plugins/latent_entropy_plugin.so ./scripts/gcc-plugins/latent_entropy_plugin.so: cannot open shared object file: No such file or directory cc1: error: cannot load plugin ./scripts/gcc-plugins/randomize_layout_plugin.so ./scripts/gcc-plugins/randomize_layout_plugin.so: cannot open shared object file: No such file or directory make[1]: *** [scripts/Makefile.build;119: arch/x86/um/user-offsets.s] Error 1 make: *** [arch/um/Makefile;152: arch/x86/um/user-offsets.s] Error 2 Reorder the preparation stage (with cleanups) to make sure gcc-plugins is built before descending to arch/x86/um/. Fixes: 6b90bd4ba40b ("GCC plugin infrastructure") Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-11-29 03:58:50 +01:00
prepare0: archprepare
$(Q)$(MAKE) $(build)=scripts/mod
$(Q)$(MAKE) $(build)=.
# All the preparing..
prepare: prepare0 prepare-objtool
# Support for using generic headers in asm-generic
asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
PHONY += asm-generic uapi-asm-generic
asm-generic: uapi-asm-generic
$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm
uapi-asm-generic:
$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm
PHONY += prepare-objtool
prepare-objtool: $(objtool_target)
ifeq ($(SKIP_STACK_VALIDATION),1)
ifdef CONFIG_UNWINDER_ORC
@echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
@false
else
@echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
endif
endif
# Generate some files
# ---------------------------------------------------------------------------
# KERNELRELEASE can change from a few different places, meaning version.h
# needs to be updated, so this check is forced on all builds
uts_len := 64
define filechk_utsrelease.h
if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
exit 1; \
fi; \
echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
endef
define filechk_version.h
echo \#define LINUX_VERSION_CODE $(shell \
expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))'
endef
$(version_h): FORCE
$(call filechk,version.h)
$(Q)rm -f $(old_version_h)
include/generated/utsrelease.h: include/config/kernel.release FORCE
$(call filechk,utsrelease.h)
PHONY += headerdep
headerdep:
$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
$(srctree)/scripts/headerdep.pl -I$(srctree)/include
# ---------------------------------------------------------------------------
# Kernel headers
#Default location for installed headers
export INSTALL_HDR_PATH = $(objtree)/usr
# If we do an all arch process set dst to include/arch-$(SRCARCH)
hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(SRCARCH), dst=include)
PHONY += archheaders archscripts
PHONY += __headers
__headers: $(version_h) scripts_basic uapi-asm-generic archheaders archscripts
$(Q)$(MAKE) $(build)=scripts build_unifdef
PHONY += headers_install_all
headers_install_all:
$(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
PHONY += headers_install
headers_install: __headers
$(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
UAPI: Plumb the UAPI Kbuilds into the user header installation and checking Plumb the UAPI Kbuilds into the user header installation and checking system. As the headers are split the entries will be transferred across from the old Kbuild files to the UAPI Kbuild files. The changes made in this commit are: (1) Exported generated files (of which there are currently four) are moved to uapi/ directories under the appropriate generated/ directory, thus we get: include/generated/uapi/linux/version.h arch/x86/include/generated/uapi/asm/unistd_32.h arch/x86/include/generated/uapi/asm/unistd_64.h arch/x86/include/generated/uapi/asm/unistd_x32.h These paths were added to the build as -I flags in a previous patch. (2) scripts/Makefile.headersinst is now given the UAPI path to install from rather than the old path. It then determines the old path from that and includes that Kbuild also if it exists, thus permitting the headers to exist in either directory during the changeover. I also renamed the "install" variable to "installdir" as it refers to a directory not the install program. (3) scripts/headers_install.pl is altered to take a list of source file paths instead of just their names so that the makefile can tell it exactly where to find each file. For the moment, files can be obtained from one of four places for each output directory: .../include/uapi/foo/ .../include/generated/uapi/foo/ .../include/foo/ .../include/generated/foo/ The non-UAPI paths will be dropped later. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>
2012-10-02 19:01:57 +02:00
$(error Headers not exportable for the $(SRCARCH) architecture))
$(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include
$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst)
PHONY += headers_check_all
headers_check_all: headers_install_all
$(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
PHONY += headers_check
headers_check: headers_install
$(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include HDRCHECK=1
$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst) HDRCHECK=1
ifdef CONFIG_HEADERS_CHECK
all: headers_check
endif
# ---------------------------------------------------------------------------
# Kernel selftest
PHONY += kselftest
kselftest:
$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
PHONY += kselftest-clean
kselftest-clean:
$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
PHONY += kselftest-merge
kselftest-merge:
$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
$(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
-m $(objtree)/.config \
$(srctree)/tools/testing/selftests/*/config
+$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
kbuild: consolidate Devicetree dtb build rules There is nothing arch specific about building dtb files other than their location under /arch/*/boot/dts/. Keeping each arch aligned is a pain. The dependencies and supported targets are all slightly different. Also, a cross-compiler for each arch is needed, but really the host compiler preprocessor is perfectly fine for building dtbs. Move the build rules to a common location and remove the arch specific ones. This is done in a single step to avoid warnings about overriding rules. The build dependencies had been a mixture of 'scripts' and/or 'prepare'. These pull in several dependencies some of which need a target compiler (specifically devicetable-offsets.h) and aren't needed to build dtbs. All that is really needed is dtc, so adjust the dependencies to only be dtc. This change enables support 'dtbs_install' on some arches which were missing the target. Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Paul Burton <paul.burton@mips.com> Acked-by: Ley Foon Tan <ley.foon.tan@intel.com> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michal Marek <michal.lkml@markovi.net> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: linux-kbuild@vger.kernel.org Cc: linux-snps-arc@lists.infradead.org Cc: linux-arm-kernel@lists.infradead.org Cc: uclinux-h8-devel@lists.sourceforge.jp Cc: linux-mips@linux-mips.org Cc: nios2-dev@lists.rocketboards.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-xtensa@linux-xtensa.org Signed-off-by: Rob Herring <robh@kernel.org>
2018-01-10 22:19:37 +01:00
# ---------------------------------------------------------------------------
# Devicetree files
ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
dtstree := arch/$(SRCARCH)/boot/dts
endif
ifneq ($(dtstree),)
%.dtb: prepare3 scripts_dtc
$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
PHONY += dtbs dtbs_install dt_binding_check
dtbs dtbs_check: prepare3 scripts_dtc
kbuild: consolidate Devicetree dtb build rules There is nothing arch specific about building dtb files other than their location under /arch/*/boot/dts/. Keeping each arch aligned is a pain. The dependencies and supported targets are all slightly different. Also, a cross-compiler for each arch is needed, but really the host compiler preprocessor is perfectly fine for building dtbs. Move the build rules to a common location and remove the arch specific ones. This is done in a single step to avoid warnings about overriding rules. The build dependencies had been a mixture of 'scripts' and/or 'prepare'. These pull in several dependencies some of which need a target compiler (specifically devicetable-offsets.h) and aren't needed to build dtbs. All that is really needed is dtc, so adjust the dependencies to only be dtc. This change enables support 'dtbs_install' on some arches which were missing the target. Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Paul Burton <paul.burton@mips.com> Acked-by: Ley Foon Tan <ley.foon.tan@intel.com> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michal Marek <michal.lkml@markovi.net> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: linux-kbuild@vger.kernel.org Cc: linux-snps-arc@lists.infradead.org Cc: linux-arm-kernel@lists.infradead.org Cc: uclinux-h8-devel@lists.sourceforge.jp Cc: linux-mips@linux-mips.org Cc: nios2-dev@lists.rocketboards.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-xtensa@linux-xtensa.org Signed-off-by: Rob Herring <robh@kernel.org>
2018-01-10 22:19:37 +01:00
$(Q)$(MAKE) $(build)=$(dtstree)
dtbs_check: export CHECK_DTBS=1
dtbs_check: dt_binding_check
kbuild: consolidate Devicetree dtb build rules There is nothing arch specific about building dtb files other than their location under /arch/*/boot/dts/. Keeping each arch aligned is a pain. The dependencies and supported targets are all slightly different. Also, a cross-compiler for each arch is needed, but really the host compiler preprocessor is perfectly fine for building dtbs. Move the build rules to a common location and remove the arch specific ones. This is done in a single step to avoid warnings about overriding rules. The build dependencies had been a mixture of 'scripts' and/or 'prepare'. These pull in several dependencies some of which need a target compiler (specifically devicetable-offsets.h) and aren't needed to build dtbs. All that is really needed is dtc, so adjust the dependencies to only be dtc. This change enables support 'dtbs_install' on some arches which were missing the target. Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Paul Burton <paul.burton@mips.com> Acked-by: Ley Foon Tan <ley.foon.tan@intel.com> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michal Marek <michal.lkml@markovi.net> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: linux-kbuild@vger.kernel.org Cc: linux-snps-arc@lists.infradead.org Cc: linux-arm-kernel@lists.infradead.org Cc: uclinux-h8-devel@lists.sourceforge.jp Cc: linux-mips@linux-mips.org Cc: nios2-dev@lists.rocketboards.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-xtensa@linux-xtensa.org Signed-off-by: Rob Herring <robh@kernel.org>
2018-01-10 22:19:37 +01:00
dtbs_install:
$(Q)$(MAKE) $(dtbinst)=$(dtstree)
ifdef CONFIG_OF_EARLY_FLATTREE
all: dtbs
endif
endif
PHONY += scripts_dtc
scripts_dtc: scripts_basic
$(Q)$(MAKE) $(build)=scripts/dtc
dt_binding_check: scripts_dtc
$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
# ---------------------------------------------------------------------------
# Modules
ifdef CONFIG_MODULES
# By default, build modules as well
all: modules
# Build modules
#
# A module can be listed more than once in obj-m resulting in
# duplicate lines in modules.order files. Those are removed
# using awk while concatenating to the final file.
PHONY += modules
modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
$(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
@$(kecho) ' Building modules, stage 2.';
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
$(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
%/modules.builtin: include/config/auto.conf include/config/tristate.conf
$(Q)$(MAKE) $(modbuiltin)=$*
# Target to prepare building external modules
PHONY += modules_prepare
modules_prepare: prepare
# Target to install modules
PHONY += modules_install
modules_install: _modinst_ _modinst_post
PHONY += _modinst_
_modinst_:
@rm -rf $(MODLIB)/kernel
@rm -f $(MODLIB)/source
@mkdir -p $(MODLIB)/kernel
@ln -s $(abspath $(srctree)) $(MODLIB)/source
@if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
rm -f $(MODLIB)/build ; \
ln -s $(CURDIR) $(MODLIB)/build ; \
fi
@cp -f $(objtree)/modules.order $(MODLIB)/
@cp -f $(objtree)/modules.builtin $(MODLIB)/
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
# This depmod is only for convenience to give the initial
# boot a modules.dep even before / is mounted read-write. However the
# boot script depmod is the master version.
PHONY += _modinst_post
_modinst_post: _modinst_
$(call cmd,depmod)
ifeq ($(CONFIG_MODULE_SIG), y)
PHONY += modules_sign
modules_sign:
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
endif
else # CONFIG_MODULES
# Modules not configured
# ---------------------------------------------------------------------------
PHONY += modules modules_install
modules modules_install:
@echo >&2
@echo >&2 "The present kernel configuration has modules disabled."
@echo >&2 "Type 'make config' and enable loadable module support."
@echo >&2 "Then build a kernel with module support enabled."
@echo >&2
@exit 1
endif # CONFIG_MODULES
###
# Cleaning is done on three levels.
# make clean Delete most generated files
# Leave enough to build external modules
# make mrproper Delete the current configuration, and all generated files
# make distclean Remove editor backup files, patch leftover files and the like
# Directories & files removed with 'make clean'
CLEAN_DIRS += $(MODVERDIR) include/ksym
# Directories & files removed with 'make mrproper'
MRPROPER_DIRS += include/config usr/include include/generated \
arch/*/include/generated .tmp_objdiff
MRPROPER_FILES += .config .config.old .version \
Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
signing_key.pem signing_key.priv signing_key.x509 \
x509.genkey extra_certificates signing_key.x509.keyid \
signing_key.x509.signer vmlinux-gdb.py
# clean - Delete most, but leave enough to build external modules
#
clean: rm-dirs := $(CLEAN_DIRS)
clean: rm-files := $(CLEAN_FILES)
clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation samples)
PHONY += $(clean-dirs) clean archclean vmlinuxclean
$(clean-dirs):
$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
vmlinuxclean:
$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
clean: archclean vmlinuxclean
# mrproper - Delete all generated files, including .config
#
mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
mrproper-dirs := $(addprefix _mrproper_,scripts)
PHONY += $(mrproper-dirs) mrproper archmrproper
$(mrproper-dirs):
$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
mrproper: clean archmrproper $(mrproper-dirs)
$(call cmd,rmdirs)
$(call cmd,rmfiles)
# distclean
#
PHONY += distclean
distclean: mrproper
@find $(srctree) $(RCS_FIND_IGNORE) \
\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
-o -name '*.bak' -o -name '#*#' -o -name '*%' \
-o -name 'core' \) \
-type f -print | xargs rm -f
# Packaging of the kernel to various formats
# ---------------------------------------------------------------------------
package-dir := scripts/package
%src-pkg: FORCE
$(Q)$(MAKE) $(build)=$(package-dir) $@
%pkg: include/config/kernel.release FORCE
$(Q)$(MAKE) $(build)=$(package-dir) $@
# Brief documentation of the typical targets used
# ---------------------------------------------------------------------------
boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
boards := $(sort $(notdir $(boards)))
board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
board-dirs := $(sort $(notdir $(board-dirs:/=)))
PHONY += help
help:
@echo 'Cleaning targets:'
@echo ' clean - Remove most generated files but keep the config and'
@echo ' enough build support to build external modules'
@echo ' mrproper - Remove all generated files + config + various backup files'
@echo ' distclean - mrproper + remove editor backup and patch files'
@echo ''
@echo 'Configuration targets:'
@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
@echo ''
@echo 'Other generic targets:'
@echo ' all - Build all targets marked with [*]'
@echo '* vmlinux - Build the bare kernel'
@echo '* modules - Build all modules'
@echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
@echo ' dir/ - Build all files in dir and below'
@echo ' dir/file.[ois] - Build specified target only'
@echo ' dir/file.ll - Build the LLVM assembly file'
@echo ' (requires compiler support for LLVM assembly generation)'
@echo ' dir/file.lst - Build specified mixed source/assembly target only'
@echo ' (requires a recent binutils and recent build (System.map))'
@echo ' dir/file.ko - Build module including final link'
@echo ' modules_prepare - Set up for building external modules'
@echo ' tags/TAGS - Generate tags file for editors'
@echo ' cscope - Generate cscope index'
@echo ' gtags - Generate GNU GLOBAL index'
@echo ' kernelrelease - Output the release version string (use with make -s)'
@echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
@echo ' image_name - Output the image name (use with make -s)'
@echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
echo ' (default: $(INSTALL_HDR_PATH))'; \
echo ''
@echo 'Static analysers:'
@echo ' checkstack - Generate a list of stack hogs'
@echo ' namespacecheck - Name space analysis on compiled kernel'
@echo ' versioncheck - Sanity check on version.h usage'
@echo ' includecheck - Check for duplicate included header files'
@echo ' export_report - List the usages of all exported symbols'
@echo ' headers_check - Sanity check on exported headers'
@echo ' headerdep - Detect inclusion cycles in headers'
@echo ' coccicheck - Check with Coccinelle'
@echo ''
@echo 'Kernel selftest:'
@echo ' kselftest - Build and run kernel selftest (run as root)'
@echo ' Build, install, and boot kernel before'
@echo ' running kselftest on it'
@echo ' kselftest-clean - Remove all generated kselftest files'
@echo ' kselftest-merge - Merge all the config dependencies of kselftest to existing'
@echo ' .config.'
@echo ''
kbuild: consolidate Devicetree dtb build rules There is nothing arch specific about building dtb files other than their location under /arch/*/boot/dts/. Keeping each arch aligned is a pain. The dependencies and supported targets are all slightly different. Also, a cross-compiler for each arch is needed, but really the host compiler preprocessor is perfectly fine for building dtbs. Move the build rules to a common location and remove the arch specific ones. This is done in a single step to avoid warnings about overriding rules. The build dependencies had been a mixture of 'scripts' and/or 'prepare'. These pull in several dependencies some of which need a target compiler (specifically devicetable-offsets.h) and aren't needed to build dtbs. All that is really needed is dtc, so adjust the dependencies to only be dtc. This change enables support 'dtbs_install' on some arches which were missing the target. Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Paul Burton <paul.burton@mips.com> Acked-by: Ley Foon Tan <ley.foon.tan@intel.com> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michal Marek <michal.lkml@markovi.net> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: linux-kbuild@vger.kernel.org Cc: linux-snps-arc@lists.infradead.org Cc: linux-arm-kernel@lists.infradead.org Cc: uclinux-h8-devel@lists.sourceforge.jp Cc: linux-mips@linux-mips.org Cc: nios2-dev@lists.rocketboards.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-xtensa@linux-xtensa.org Signed-off-by: Rob Herring <robh@kernel.org>
2018-01-10 22:19:37 +01:00
@$(if $(dtstree), \
echo 'Devicetree:'; \
echo '* dtbs - Build device tree blobs for enabled boards'; \
echo ' dtbs_install - Install dtbs to $(INSTALL_DTBS_PATH)'; \
echo '')
@echo 'Userspace tools targets:'
@echo ' use "make tools/help"'
@echo ' or "cd tools; make help"'
@echo ''
@echo 'Kernel packaging:'
@$(MAKE) $(build)=$(package-dir) help
@echo ''
@echo 'Documentation targets:'
@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
@echo ''
@echo 'Architecture specific targets ($(SRCARCH)):'
@$(if $(archhelp),$(archhelp),\
echo ' No architecture specific help defined for $(SRCARCH)')
@echo ''
@$(if $(boards), \
$(foreach b, $(boards), \
printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
echo '')
@$(if $(board-dirs), \
$(foreach b, $(board-dirs), \
printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
printf " %-16s - Show all of the above\\n" help-boards; \
echo '')
@echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
@echo ' make V=2 [targets] 2 => give reason for rebuild of target'
@echo ' make O=dir [targets] Locate all output files in "dir", including .config'
@echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
@echo ' make C=2 [targets] Force check of all c source with $$CHECK'
@echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
@echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3 where'
@echo ' 1: warnings which may be relevant and do not occur too often'
@echo ' 2: warnings which occur quite often but may still be relevant'
@echo ' 3: more obscure warnings, can most likely be ignored'
@echo ' Multiple levels can be combined with W=12 or W=123'
@echo ''
@echo 'Execute "make" or "make all" to build all targets marked with [*] '
@echo 'For further info see the ./README file'
help-board-dirs := $(addprefix help-,$(board-dirs))
help-boards: $(help-board-dirs)
boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
$(help-board-dirs): help-%:
@echo 'Architecture specific targets ($(SRCARCH) $*):'
@$(if $(boards-per-dir), \
$(foreach b, $(boards-per-dir), \
printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
echo '')
# Documentation targets
# ---------------------------------------------------------------------------
DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
linkcheckdocs dochelp refcheckdocs
Documentation/sphinx: add basic working Sphinx configuration and build Add basic configuration and makefile to build documentation from any .rst files under Documentation using Sphinx. For starters, there's just the placeholder index.rst. At the top level Makefile, hook Sphinx documentation targets alongside (but independent of) the DocBook toolchain, having both be run on the various 'make *docs' targets. All Sphinx processing is placed into Documentation/Makefile.sphinx. Both that and the Documentation/DocBook/Makefile are now expected to handle all the documentation targets, explicitly ignoring them if they're not relevant for that particular toolchain. The changes to the existing DocBook Makefile are kept minimal. There is graceful handling of missing Sphinx and rst2pdf (which is needed for pdf output) by checking for the tool and python module, respectively, with informative messages to the user. If the Read the Docs theme (sphinx_rtd_theme) is available, use it, but otherwise gracefully fall back to the Sphinx default theme, with an informative message to the user, and slightly less pretty HTML output. Sphinx can now handle htmldocs, pdfdocs (if rst2pdf is available), epubdocs and xmldocs targets. The output documents are written into per output type subdirectories under Documentation/output. Finally, you can pass options to sphinx-build using the SPHINXBUILD make variable. For example, 'make SPHINXOPTS=-v htmldocs' for more verbose output from Sphinx. This is based on the original work by Jonathan Corbet, but he probably wouldn't recognize this as his own anymore. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-05-19 14:14:05 +02:00
PHONY += $(DOC_TARGETS)
$(DOC_TARGETS): scripts_basic FORCE
$(Q)$(MAKE) $(build)=Documentation $@
else # KBUILD_EXTMOD
###
# External module support.
# When building external modules the kernel used as basis is considered
# read-only, and no consistency checks are made and the make
# system is not used on the basis kernel. If updates are required
# in the basis kernel ordinary make commands (without M=...) must
# be used.
#
# The following are the only valid targets when building external
# modules.
# make M=dir clean Delete all automatically generated files
# make M=dir modules Make all modules in specified dir
# make M=dir Same as 'make M=dir modules'
# make M=dir modules_install
# Install the modules built in the module directory
# Assumes install directory is already created
# We are always building modules
KBUILD_MODULES := 1
PHONY += $(objtree)/Module.symvers
$(objtree)/Module.symvers:
@test -e $(objtree)/Module.symvers || ( \
echo; \
echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
echo " is missing; modules will have no dependencies and modversions."; \
echo )
module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
PHONY += $(module-dirs) modules
$(module-dirs): prepare $(objtree)/Module.symvers
$(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
modules: $(module-dirs)
@$(kecho) ' Building modules, stage 2.';
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
PHONY += modules_install
modules_install: _emodinst_ _emodinst_post
install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
PHONY += _emodinst_
_emodinst_:
$(Q)mkdir -p $(MODLIB)/$(install-dir)
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
PHONY += _emodinst_post
_emodinst_post: _emodinst_
$(call cmd,depmod)
clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
PHONY += $(clean-dirs) clean
$(clean-dirs):
$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
clean: rm-dirs := $(MODVERDIR)
clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
PHONY += help
help:
@echo ' Building external modules.'
@echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
@echo ''
@echo ' modules - default target, build the module(s)'
@echo ' modules_install - install the module'
@echo ' clean - remove generated files in module directory only'
@echo ''
PHONY += prepare
prepare:
$(cmd_crmodverdir)
endif # KBUILD_EXTMOD
clean: $(clean-dirs)
$(call cmd,rmdirs)
$(call cmd,rmfiles)
@find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
\( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
-o -name '*.ko.*' \
-o -name '*.dtb' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
-o -name '*.dwo' -o -name '*.lst' \
-o -name '*.su' \
-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
-o -name '*.lex.c' -o -name '*.tab.[ch]' \
-o -name '*.asn1.[ch]' \
-o -name '*.symtypes' -o -name 'modules.order' \
-o -name modules.builtin -o -name '.tmp_*.o.*' \
GCC plugin infrastructure This patch allows to build the whole kernel with GCC plugins. It was ported from grsecurity/PaX. The infrastructure supports building out-of-tree modules and building in a separate directory. Cross-compilation is supported too. Currently the x86, arm, arm64 and uml architectures enable plugins. The directory of the gcc plugins is scripts/gcc-plugins. You can use a file or a directory there. The plugins compile with these options: * -fno-rtti: gcc is compiled with this option so the plugins must use it too * -fno-exceptions: this is inherited from gcc too * -fasynchronous-unwind-tables: this is inherited from gcc too * -ggdb: it is useful for debugging a plugin (better backtrace on internal errors) * -Wno-narrowing: to suppress warnings from gcc headers (ipa-utils.h) * -Wno-unused-variable: to suppress warnings from gcc headers (gcc_version variable, plugin-version.h) The infrastructure introduces a new Makefile target called gcc-plugins. It supports all gcc versions from 4.5 to 6.0. The scripts/gcc-plugin.sh script chooses the proper host compiler (gcc-4.7 can be built by either gcc or g++). This script also checks the availability of the included headers in scripts/gcc-plugins/gcc-common.h. The gcc-common.h header contains frequently included headers for GCC plugins and it has a compatibility layer for the supported gcc versions. The gcc-generate-*-pass.h headers automatically generate the registration structures for GIMPLE, SIMPLE_IPA, IPA and RTL passes. Note that 'make clean' keeps the *.so files (only the distclean or mrproper targets clean all) because they are needed for out-of-tree modules. Based on work created by the PaX Team. Signed-off-by: Emese Revfy <re.emese@gmail.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-05-24 00:09:38 +02:00
-o -name '*.c.[012]*.*' \
-o -name '*.ll' \
-o -name '*.gcno' \) -type f -print | xargs rm -f
# Generate tags for editors
# ---------------------------------------------------------------------------
quiet_cmd_tags = GEN $@
cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
tags TAGS cscope gtags: FORCE
$(call cmd,tags)
# Scripts to check various things for consistency
# ---------------------------------------------------------------------------
PHONY += includecheck versioncheck coccicheck namespacecheck export_report
includecheck:
find $(srctree)/* $(RCS_FIND_IGNORE) \
-name '*.[hcS]' -type f -print | sort \
| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
versioncheck:
find $(srctree)/* $(RCS_FIND_IGNORE) \
-name '*.[hcS]' -type f -print | sort \
| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
coccicheck:
$(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
namespacecheck:
$(PERL) $(srctree)/scripts/namespace.pl
export_report:
$(PERL) $(srctree)/scripts/export_report.pl
PHONY += checkstack kernelrelease kernelversion image_name
# UML needs a little special treatment here. It wants to use the host
# toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
# else wants $(ARCH), including people doing cross-builds, which means
# that $(SUBARCH) doesn't work here.
ifeq ($(ARCH), um)
CHECKSTACK_ARCH := $(SUBARCH)
else
CHECKSTACK_ARCH := $(ARCH)
endif
checkstack:
$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
$(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
kernelrelease:
@echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
kernelversion:
@echo $(KERNELVERSION)
image_name:
@echo $(KBUILD_IMAGE)
# Clear a bunch of variables before executing the submake
tools/: FORCE
tools: Honour the O= flag when tool build called from a higher Makefile Honour the O= flag that was passed to a higher level Makefile and then passed down as part of a tool build. To make this work, the top-level Makefile passes the original O= flag and subdir=tools to the tools/Makefile, and that in turn passes subdir=$(O)/$(subdir)/foodir when building tool foo in directory $(O)/$(subdir)/foodir (where the intervening slashes aren't added if an element is missing). For example, take perf. This is found in tools/perf/. Assume we're building into directory ~/zebra/, so we pass O=~/zebra to make. Dependening on where we run the build from, we see: make run in dir $(OUTPUT) dir ======================= ================== linux ~/zebra/tools/perf/ linux/tools ~/zebra/perf/ linux/tools/perf ~/zebra/ and if O= is not set, we get: make run in dir $(OUTPUT) dir ======================= ================== linux linux/tools/perf/ linux/tools linux/tools/perf/ linux/tools/perf linux/tools/perf/ The output directories are created by the descend function if they don't already exist. Signed-off-by: David Howells <dhowells@redhat.com> Cc: Borislav Petkov <bp@amd64.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1378.1352379110@warthog.procyon.org.uk Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-11-05 22:02:08 +01:00
$(Q)mkdir -p $(objtree)/tools
$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
tools/%: FORCE
tools: Honour the O= flag when tool build called from a higher Makefile Honour the O= flag that was passed to a higher level Makefile and then passed down as part of a tool build. To make this work, the top-level Makefile passes the original O= flag and subdir=tools to the tools/Makefile, and that in turn passes subdir=$(O)/$(subdir)/foodir when building tool foo in directory $(O)/$(subdir)/foodir (where the intervening slashes aren't added if an element is missing). For example, take perf. This is found in tools/perf/. Assume we're building into directory ~/zebra/, so we pass O=~/zebra to make. Dependening on where we run the build from, we see: make run in dir $(OUTPUT) dir ======================= ================== linux ~/zebra/tools/perf/ linux/tools ~/zebra/perf/ linux/tools/perf ~/zebra/ and if O= is not set, we get: make run in dir $(OUTPUT) dir ======================= ================== linux linux/tools/perf/ linux/tools linux/tools/perf/ linux/tools/perf linux/tools/perf/ The output directories are created by the descend function if they don't already exist. Signed-off-by: David Howells <dhowells@redhat.com> Cc: Borislav Petkov <bp@amd64.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1378.1352379110@warthog.procyon.org.uk Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-11-05 22:02:08 +01:00
$(Q)mkdir -p $(objtree)/tools
$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $*
# Single targets
# ---------------------------------------------------------------------------
# Single targets are compatible with:
# - build with mixed source and output
# - build with separate output dir 'make O=...'
# - external modules
#
# target-dir => where to store outputfile
# build-dir => directory in kernel source tree to use
ifeq ($(KBUILD_EXTMOD),)
build-dir = $(patsubst %/,%,$(dir $@))
target-dir = $(dir $@)
else
zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
build-dir = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
endif
%.s: %.c prepare FORCE
$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
%.i: %.c prepare FORCE
$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
%.o: %.c prepare FORCE
$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
%.lst: %.c prepare FORCE
$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
%.s: %.S prepare FORCE
$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
%.o: %.S prepare FORCE
$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
%.symtypes: %.c prepare FORCE
kbuild: support for %.symtypes files Here is a patch that adds a new -T option to genksyms for generating dumps of the type definition that makes up the symbol version hashes. This allows to trace modversion changes back to what caused them. The dump format is the name of the type defined, followed by its definition (which is almost C): s#list_head struct list_head { s#list_head * next , * prev ; } The s#, u#, e#, and t# prefixes stand for struct, union, enum, and typedef. The exported symbols do not define types, and thus do not have an x# prefix: nfs4_acl_get_whotype int nfs4_acl_get_whotype ( char * , t#u32 ) The symbol type defintion of a single file can be generated with: make fs/jbd/journal.symtypes If KBUILD_SYMTYPES is defined, all the *.symtypes of all object files that export symbols are generated. The single *.symtypes files can be combined into a single file after a kernel build with a script like the following: for f in $(find -name '*.symtypes' | sort); do f=${f#./} echo "/* ${f%.symtypes}.o */" cat $f echo done \ | sed -e '\:UNKNOWN:d' \ -e 's:[,;] }:}:g' \ -e 's:\([[({]\) :\1:g' \ -e 's: \([])},;]\):\1:g' \ -e 's: $::' \ $f \ | awk ' /^.#/ { if (defined[$1] == $0) { print $1 next } defined[$1] = $0 } { print } ' When the kernel ABI changes, diffing individual *.symtype files, or the combined files, against each other will show which symbol changes caused the ABI changes. This can save a tremendous amount of time. Dump the types that make up modversions Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-05-09 20:37:30 +02:00
$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
%.ll: %.c prepare FORCE
$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
# Modules
/: prepare FORCE
$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
$(build)=$(build-dir)
# Make sure the latest headers are built for Documentation
Documentation/ samples/: headers_install
%/: prepare FORCE
$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
$(build)=$(build-dir)
%.ko: prepare FORCE
$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
$(build)=$(build-dir) $(@:.ko=.o)
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
# FIXME Should go into a make.lib or something
# ===========================================================================
quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
cmd_rmdirs = rm -rf $(rm-dirs)
quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
cmd_rmfiles = rm -f $(rm-files)
# Run depmod only if we have System.map and depmod is executable
quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
$(KERNELRELEASE)
# Create temporary dir for module support files
# clean it up only when building all modules
cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
$(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
kbuild: let fixdep directly write to .*.cmd files Currently, fixdep writes dependencies to .*.tmp, which is renamed to .*.cmd after everything succeeds. This is a very safe way to avoid corrupted .*.cmd files. The if_changed_dep has carried this safety mechanism since it was added in 2002. If fixdep fails for some reasons or a user terminates the build while fixdep is running, the incomplete output from the fixdep could be troublesome. This is my insight about some bad scenarios: [1] If the compiler succeeds to generate *.o file, but fixdep fails to write necessary dependencies to .*.cmd file, Make will miss to rebuild the object when headers or CONFIG options are changed. In this case, fixdep should not generate .*.cmd file at all so that 'arg-check' will surely trigger the rebuild of the object. [2] A partially constructed .*.cmd file may not be a syntactically correct makefile. The next time Make runs, it would include it, then fail to parse it. Once this happens, 'make clean' is be the only way to fix it. In fact, [1] is no longer a problem since commit 9c2af1c7377a ("kbuild: add .DELETE_ON_ERROR special target"). Make deletes a target file on any failure in its recipe. Because fixdep is a part of the recipe of *.o target, if it fails, the *.o is deleted anyway. However, I am a bit worried about the slight possibility of [2]. So, here is a solution. Let fixdep directly write to a .*.cmd file, but allow makefiles to include it only when its corresponding target exists. This effectively reverts commit 2982c953570b ("kbuild: remove redundant $(wildcard ...) for cmd_files calculation"), and commit 00d78ab2ba75 ("kbuild: remove dead code in cmd_files calculation in top Makefile") because now we must check the presence of targets. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-11-30 02:05:22 +01:00
# read saved command lines for existing targets
existing-targets := $(wildcard $(sort $(targets)))
kbuild: let fixdep directly write to .*.cmd files Currently, fixdep writes dependencies to .*.tmp, which is renamed to .*.cmd after everything succeeds. This is a very safe way to avoid corrupted .*.cmd files. The if_changed_dep has carried this safety mechanism since it was added in 2002. If fixdep fails for some reasons or a user terminates the build while fixdep is running, the incomplete output from the fixdep could be troublesome. This is my insight about some bad scenarios: [1] If the compiler succeeds to generate *.o file, but fixdep fails to write necessary dependencies to .*.cmd file, Make will miss to rebuild the object when headers or CONFIG options are changed. In this case, fixdep should not generate .*.cmd file at all so that 'arg-check' will surely trigger the rebuild of the object. [2] A partially constructed .*.cmd file may not be a syntactically correct makefile. The next time Make runs, it would include it, then fail to parse it. Once this happens, 'make clean' is be the only way to fix it. In fact, [1] is no longer a problem since commit 9c2af1c7377a ("kbuild: add .DELETE_ON_ERROR special target"). Make deletes a target file on any failure in its recipe. Because fixdep is a part of the recipe of *.o target, if it fails, the *.o is deleted anyway. However, I am a bit worried about the slight possibility of [2]. So, here is a solution. Let fixdep directly write to a .*.cmd file, but allow makefiles to include it only when its corresponding target exists. This effectively reverts commit 2982c953570b ("kbuild: remove redundant $(wildcard ...) for cmd_files calculation"), and commit 00d78ab2ba75 ("kbuild: remove dead code in cmd_files calculation in top Makefile") because now we must check the presence of targets. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-11-30 02:05:22 +01:00
cmd_files := $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
$(cmd_files): ; # Do not try to update included dependency files
-include $(cmd_files)
endif # ifeq ($(config-targets),1)
endif # ifeq ($(mixed-targets),1)
endif # skip-makefile
PHONY += FORCE
FORCE:
# Declare the contents of the PHONY variable as phony. We keep that
# information in a variable so we can use it in if_changed and friends.
.PHONY: $(PHONY)