linux/scripts/Makefile.lib, branch v4.16-rc2

kasan: don't emit builtin calls when sanitization is off

2018-02-07T02:32:42Z

With KASAN enabled the kernel has two different memset() functions, one with KASAN checks (memset) and one without (__memset). KASAN uses some macro tricks to use the proper version where required. For example memset() calls in mm/slub.c are without KASAN checks, since they operate on poisoned slab object metadata. The issue is that clang emits memset() calls even when there is no memset() in the source code. They get linked with improper memset() implementation and the kernel fails to boot due to a huge amount of KASAN reports during early boot stages. The solution is to add -fno-builtin flag for files with KASAN_SANITIZE := n marker. Link: http://lkml.kernel.org/r/8ffecfffe04088c52c42b92739c2bd8a0bcb3f5e.1516384594.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Acked-by: Nick Desaulniers Cc: Masahiro Yamada Cc: Michal Marek Cc: Andrey Ryabinin Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'kconfig-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2018-02-01T19:45:49Z

Pull Kconfig updates from Masahiro Yamada: "A pretty big batch of Kconfig updates. I have to mention the lexer and parser of Kconfig are now built from real .l and .y sources. So, flex and bison are the requirement for building the kernel. Both of them (unlike gperf) have been stable for a long time. This change has been tested several weeks in linux-next, and I did not receive any problem report about this. Summary: - add checks for mistakes, like the choice default is not in choice, help is doubled - document data structure and complex code - fix various memory leaks - change Makefile to build lexer and parser instead of using pre-generated C files - drop 'boolean' keyword, which is equivalent to 'bool' - use default 'yy' prefix and remove unneeded Make variables - fix gettext() check for xconfig - announce that oldnoconfig will be finally removed - make 'Selected by:' and 'Implied by' readable in help and search result - hide silentoldconfig from 'make help' to stop confusing people - fix misc things and cleanups" * tag 'kconfig-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (37 commits) kconfig: Remove silentoldconfig from help and docs; fix kconfig/conf's help kconfig: make "Selected by:" and "Implied by:" readable kconfig: announce removal of oldnoconfig if used kconfig: fix make xconfig when gettext is missing kconfig: Clarify menu and 'if' dependency propagation kconfig: Document 'if' flattening logic kconfig: Clarify choice dependency propagation kconfig: Document SYMBOL_OPTIONAL logic kbuild: remove unnecessary LEX_PREFIX and YACC_PREFIX kconfig: use default 'yy' prefix for lexer and parser kconfig: make conf_unsaved a local variable of conf_read() kconfig: make xfgets() really static kconfig: make input_mode static kconfig: Warn if there is more than one help text kconfig: drop 'boolean' keyword kconfig: use bool instead of boolean for type definition attributes, again kconfig: Remove menu_end_entry() kconfig: Document important expression functions kconfig: Document automatic submenu creation code kconfig: Fix choice symbol expression leak ...

kbuild: fix W= option checks for extra DTC warnings

2018-01-25T13:17:25Z

Kbuild supports 3 levels of extra warnings, and multiple levels can be combined, like W=12, W=123. It was added by commit a6de553da01c ("kbuild: Allow to combine multiple W= levels"). From the log of commit 8654cb8d0371 ("dtc: update warning settings for new bus and node/property name checks"), I assume: - unit_address_vs_reg, simple_bus_reg, etc. belong to level 1 - node_name_chars_strict, property_name_chars_strict belong to level 2 However, the level 1 warnings are displayed by any argument to W=. On the other hand, the level 2 warnings are displayed by W=2, but not by W=12, or W=123. Use $(findstring ...) like scripts/Makefile.extrawarn. Signed-off-by: Masahiro Yamada Acked-by: Arnd Bergmann

kbuild: remove unnecessary LEX_PREFIX and YACC_PREFIX

2018-01-21T15:49:31Z

Kconfig was the only user of these. With Kconfig converted to use the default 'yy' prefix, we do not need them any more. Signed-off-by: Masahiro Yamada Reviewed-by: Ulf Magnusson

kbuild: prepare to remove C files pre-generated by flex and bison

2017-12-16T02:12:53Z

In Linux build system convention, pre-generated files are version- controlled with a "_shipped" suffix. During the kernel building, they are simply shipped (copied) removing the suffix. This approach can reduce external tool dependency for the kernel build, but it is tedious to manually regenerate such artifacts from developers' point of view. (We need to do "make REGENERATE_PARSERS=1" every time we touch real source files such as *.l, *.y) Some months ago, I sent out RFC patches to run flex, bison, and gperf during the build. In the review and test, Linus noticed gperf-3.1 had changed the lookup function prototype. Then, the use of gperf in kernel was entirely removed by commit bb3290d91695 ("Remove gperf usage from toolchain"). This time, I tested several versions of flex and bison, and I was not hit by any compatibility issue except a flaw in flex-2.6.3; if you generate lexer for dtc and genksyms with flex-2.6.3, you will see "yywrap redefined" warning. This was not intentional, but a bug, fixed by flex-2.6.4. Otherwise, both flex and bison look fairly stable for a long time. This commit prepares some build rules to remove the _shipped files. Also, document minimal requirement for flex and bison. Rationale for the minimal version: The -Wmissing-prototypes option of GCC warns "no previous prototype" for lexers generated by flex-2.5.34 or older, so I chose 2.5.35 as the required version for flex. Flex-2.5.35 was released in 2008. Bison looks more stable. I did not see any problem with bison-2.0, released in 2004. I did not test bison-1.x, but bison-2.0 should be old enough. Tested flex versions: 2.5.35 2.5.36 2.5.37 2.5.39 2.6.0 2.6.1 2.6.2 2.6.3 (*) 2.6.4 (*) flex-2.6.3 causes "yywrap redefined" warning Tested bison versions: 2.0 2.1 2.2 2.3 2.4 2.4.1 2.5.1 2.6 2.6.1 2.6.2 2.6.3 2.6.4 2.6.5 2.7 2.7.1 3.0 3.0.1 3.0.2 3.0.3 3.0.4 Signed-off-by: Masahiro Yamada

kbuild: add LEX and YACC variables

2017-12-16T02:12:53Z

Allow users to use their favorite lexer / parser generators. This is useful for me to test various flex and bison versions. Signed-off-by: Masahiro Yamada

kbuild: drop $(extra-y) from real-objs-y

2017-11-23T14:29:26Z

$(real-objs-y) in only used in scripts/Makefile.build to form "targets", but $(extra-y) is added to "targets" in another line. We do not need to add $(extra-y) twice. Signed-off-by: Masahiro Yamada

Merge tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2017-11-18T01:45:29Z

Pull Kbuild updates from Masahiro Yamada: "One of the most remarkable improvements in this cycle is, Kbuild is now able to cache the result of shell commands. Some variables are expensive to compute, for example, $(call cc-option,...) invokes the compiler. It is not efficient to redo this computation every time, even when we are not actually building anything. Kbuild creates a hidden file ".cache.mk" that contains invoked shell commands and their results. The speed-up should be noticeable. Summary: - Fix arch build issues (hexagon, sh) - Clean up various Makefiles and scripts - Fix wrong usage of {CFLAGS,LDFLAGS}_MODULE in arch Makefiles - Cache variables that are expensive to compute - Improve cc-ldopton and ld-option for Clang - Optimize output directory creation" * tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits) kbuild: move coccicheck help from scripts/Makefile.help to top Makefile sh: decompressor: add shipped files to .gitignore frv: .gitignore: ignore vmlinux.lds selinux: remove unnecessary assignment to subdir- kbuild: specify FORCE in Makefile.headersinst as .PHONY target kbuild: remove redundant mkdir from ./Kbuild kbuild: optimize object directory creation for incremental build kbuild: create object directories simpler and faster kbuild: filter-out PHONY targets from "targets" kbuild: remove redundant $(wildcard ...) for cmd_files calculation kbuild: create directory for make cache only when necessary sh: select KBUILD_DEFCONFIG depending on ARCH kbuild: fix linker feature test macros when cross compiling with Clang kbuild: shrink .cache.mk when it exceeds 1000 lines kbuild: do not call cc-option before KBUILD_CFLAGS initialization kbuild: Cache a few more calls to the compiler kbuild: Add a cache for generated variables kbuild: add forward declaration of default target to Makefile.asm-generic kbuild: remove KBUILD_SUBDIR_ASFLAGS and KBUILD_SUBDIR_CCFLAGS hexagon/kbuild: replace CFLAGS_MODULE with KBUILD_CFLAGS_MODULE ...

kbuild: create object directories simpler and faster

2017-11-16T00:07:35Z

For the out-of-tree build, scripts/Makefile.build creates output directories, but this operation is not efficient. scripts/Makefile.lib calculates obj-dirs as follows: obj-dirs := $(dir $(multi-objs) $(obj-y)) Please notice $(sort ...) is not used here. Usually the result is as many "./" as objects here. For a lot of duplicated paths, the following command is invoked. _dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d))) Then, the costly shell command is run over and over again. I see many points for optimization: [1] Use $(sort ...) to cut down duplicated paths before passing them to system call [2] Use single $(shell ...) instead of repeating it with $(foreach ...) This will reduce forking. [3] We can calculate obj-dirs more simply. Most of objects are already accumulated in $(targets). So, $(dir $(targets)) is fine and more comprehensive. I also removed ugly code in arch/x86/entry/vdso/Makefile. This is now really unnecessary. Signed-off-by: Masahiro Yamada Acked-by: Ingo Molnar Tested-by: Douglas Anderson

Merge tag 'devicetree-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

2017-11-15T02:25:40Z

Pull DeviceTree updates from Rob Herring: "A bigger diffstat than usual with the kbuild changes and a tree wide fix in the binding documentation. Summary: - kbuild cleanups and improvements for dtbs - Code clean-up of overlay code and fixing for some long standing memory leak and race condition in applying overlays - Improvements to DT memory usage making sysfs/kobjects optional and skipping unflattening of disabled nodes. This is part of kernel tinification efforts. - Final piece of removing storing the full path for every DT node. The prerequisite conversion of printk's to use device_node format specifier happened in 4.14. - Sync with current upstream dtc. This brings additional checks to dtb compiling. - Binding doc tree wide removal of leading 0s from examples - RTC binding documentation adding missing devices and some consolidation of duplicated bindings - Vendor prefix documentation for nutsboard, Silicon Storage Technology, shimafuji, Tecon Microprocessor Technologies, DH electronics GmbH, Opal Kelly, and Next Thing" * tag 'devicetree-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (55 commits) dt-bindings: usb: add #phy-cells to usb-nop-xceiv dt-bindings: Remove leading zeros from bindings notation kbuild: handle dtb-y and CONFIG_OF_ALL_DTBS natively in Makefile.lib MIPS: dts: remove bogus bcm96358nb4ser.dtb from dtb-y entry kbuild: clean up *.dtb and *.dtb.S patterns from top-level Makefile .gitignore: move *.dtb and *.dtb.S patterns to the top-level .gitignore .gitignore: sort normal pattern rules alphabetically dt-bindings: add vendor prefix for Next Thing Co. scripts/dtc: Update to upstream version v1.4.5-6-gc1e55a5513e9 of: dynamic: fix memory leak related to properties of __of_node_dup of: overlay: make pr_err() string unique of: overlay: pr_err from return NOTIFY_OK to overlay apply/remove of: overlay: remove unneeded check for NULL kbasename() of: overlay: remove a dependency on device node full_name of: overlay: simplify applying symbols from an overlay of: overlay: avoid race condition between applying multiple overlays of: overlay: loosen overly strict phandle clash check of: overlay: expand check of whether overlay changeset can be removed of: overlay: detect cases where device tree may become corrupt of: overlay: minor restructuring ...