18 Mar, 2019
1 commit
17 Mar, 2019
2 commits
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Currently, every arch/*/include/uapi/asm/Kbuild explicitly includes
the common Kbuild.asm file. Factor out the duplicated include directives
to scripts/Makefile.asm-generic so that no architecture would opt out
of the mandatory-y mechanism.um is not forced to include mandatory-y since it is a very exceptional
case which does not support UAPI.Signed-off-by: Masahiro Yamada
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During a simple no-op (nothing changed) build I saw 39 invocations of
the C compiler with the argument "-print-file-name=include". We don't
need to call the C compiler 39 times for this--one time will suffice.Let's change NOSTDINC_FLAGS to a simply expanded variable to avoid
this since there doesn't appear to be any reason it should be
recursively expanded.On my build this shaved ~400 ms off my "no-op" build.
Note that the recursive expansion seems to date back to the (really
old) commit e8f5bdb02ce0 ("[PATCH] Makefile include path ordering").
It's a little unclear to me if the point of that patch was to switch
the variable to be recursively expanded (which it did) or to avoid
directly assigning to NOSTDINC_FLAGS (AKA to switch to +=) because
someone else (out of tree?) was setting it. I presume later since if
the only goal was to switch to recursive expansion the patch would
have just removed the ":".Signed-off-by: Douglas Anderson
Signed-off-by: Masahiro Yamada
14 Mar, 2019
1 commit
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Since commit 3812b8c5c5d5 ("kbuild: make -r/-R effective in top
Makefile for old Make versions"), make-kpkg is not working.make-kpkg directly includes the top Makefile of Linux kernel, and
appends some debian_* targets./usr/share/kernel-package/ruleset/kernel_version.mk:
# Include the kernel makefile
override dot-config := 1
include Makefile
dot-config := 1I did not know the kernel Makefile was used in that way, and it is
hard to guarantee the behavior when the kernel Makefile is included
by another Makefile from a different project.It looks like Debian Stretch stopped providing make-kpkg. Maybe it is
obsolete and being replaced with 'make deb-pkg' etc. but still widely
used.This commit adds a workaround; if the top Makefile is included by
another Makefile, skip sub-make in order to make the main part visible.
'MAKEFLAGS += -rR' does not become effective for GNU Make < 4.0, but
Debian/Ubuntu is already using newer versions.The effect of this commit:
Debian 8 (Jessie) : Fixed
Debian 9 (Stretch) : make-kpkg (kernel-package) is not provided
Ubuntu 14.04 LTS : NOT Fixed
Ubuntu 16.04 LTS : Fixed
Ubuntu 18.04 LTS : FixedThis commit cannot fix Ubuntu 14.04 because it installs GNU Make 3.81,
but its support will end in Apr 2019, which is before the Linux v5.1
release.I added warning so that nobody would try to include the top Makefile.
Fixes: 3812b8c5c5d5 ("kbuild: make -r/-R effective in top Makefile for old Make versions")
Reported-by: Liz Zhang
Signed-off-by: Masahiro Yamada
Tested-by: Lili Deng
Cc: Manoj Srivastava
11 Mar, 2019
1 commit
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Pull Kbuild updates from Masahiro Yamada:
- do not generate unneeded top-level built-in.a
- let git ignore O= directory entirely
- optimize scripts/kallsyms slightly
- exclude DWARF info from *.s regardless of config options
- fix GCC toolchain search path for Clang to prepare ld.lld support
- do not generate modules.order when CONFIG_MODULES is disabled
- simplify single target rules and remove VPATH for external module
build- allow to add optional flags to dpkg-buildpackage when building
deb-pkg- move some compiler option tests from Makefile to Kconfig
- various Makefile cleanups
* tag 'kbuild-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (40 commits)
kbuild: remove scripts/basic/% build target
kbuild: use -Werror=implicit-... instead of -Werror-implicit-...
kbuild: clean up scripts/gcc-version.sh
kbuild: remove cc-version macro
kbuild: update comment block of scripts/clang-version.sh
kbuild: remove commented-out INITRD_COMPRESS
kbuild: move -gsplit-dwarf, -gdwarf-4 option tests to Kconfig
kbuild: [bin]deb-pkg: add DPKG_FLAGS variable
kbuild: move ".config not found!" message from Kconfig to Makefile
kbuild: invoke syncconfig if include/config/auto.conf.cmd is missing
kbuild: simplify single target rules
kbuild: remove empty rules for makefiles
kbuild: make -r/-R effective in top Makefile for old Make versions
kbuild: move tools_silent to a more relevant place
kbuild: compute false-positive -Wmaybe-uninitialized cases in Kconfig
kbuild: refactor cc-cross-prefix implementation
kbuild: hardcode genksyms path and remove GENKSYMS variable
scripts/gdb: refactor rules for symlink creation
kbuild: create symlink to vmlinux-gdb.py in scripts_gdb target
scripts/gdb: do not descend into scripts/gdb from scripts
...
07 Mar, 2019
1 commit
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Pull driver core updates from Greg KH:
"Here is the big driver core patchset for 5.1-rc1More patches than "normal" here this merge window, due to some work in
the driver core by Alexander Duyck to rework the async probe
functionality to work better for a number of devices, and independant
work from Rafael for the device link functionality to make it work
"correctly".Also in here is:
- lots of BUS_ATTR() removals, the macro is about to go away
- firmware test fixups
- ihex fixups and simplification
- component additions (also includes i915 patches)
- lots of minor coding style fixups and cleanups.
All of these have been in linux-next for a while with no reported
issues"* tag 'driver-core-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (65 commits)
driver core: platform: remove misleading err_alloc label
platform: set of_node in platform_device_register_full()
firmware: hardcode the debug message for -ENOENT
driver core: Add missing description of new struct device_link field
driver core: Fix PM-runtime for links added during consumer probe
drivers/component: kerneldoc polish
async: Add cmdline option to specify drivers to be async probed
driver core: Fix possible supplier PM-usage counter imbalance
PM-runtime: Fix __pm_runtime_set_status() race with runtime resume
driver: platform: Support parsing GpioInt 0 in platform_get_irq()
selftests: firmware: fix verify_reqs() return value
Revert "selftests: firmware: remove use of non-standard diff -Z option"
Revert "selftests: firmware: add CONFIG_FW_LOADER_USER_HELPER_FALLBACK to config"
device: Fix comment for driver_data in struct device
kernfs: Allocating memory for kernfs_iattrs with kmem_cache.
sysfs: remove unused include of kernfs-internal.h
driver core: Postpone DMA tear-down until after devres release
driver core: Document limitation related to DL_FLAG_RPM_ACTIVE
PM-runtime: Take suppliers into account in __pm_runtime_set_status()
device.h: Add __cold to dev_ logging functions
...
05 Mar, 2019
1 commit
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This build rule was introduced by commit cd05e6bdc600 ("[PATCH]
kbuild: fix split-include dependency") to handle the dependency of
scripts/basic/split-include.Now, fixdep is the only tool in scripts/basic/, and this rule is
no longer used.Signed-off-by: Masahiro Yamada
04 Mar, 2019
3 commits
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The flag '-Werror-implicit-function-declaration', present in GCC 2.95,
stopped to be documented in GCC 4.3, replaced by the more generic
'-Werror=...' form.So, use the equivalent '-Werror=implicit-function-declaration' instead.
Signed-off-by: Luc Van Oostenryck
Signed-off-by: Masahiro Yamada -
This code has been commented out since commit b7000adef17a
("Don't set the INITRD_COMPRESS environment variable automatically").Clean it up now.
Signed-off-by: Masahiro Yamada
28 Feb, 2019
1 commit
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CONFIG_DEBUG_INFO_SPLIT and CONFIG_DEBUG_INFO_DWARF4 enable extra
dwarf options if supported. You never know if they are really enabled
since Makefile may silently turn them off.The actual behavior will match to the kernel configuration by
testing those compiler flags in the Kconfig stage.Signed-off-by: Masahiro Yamada
27 Feb, 2019
11 commits
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If you run "make" in a pristine source tree, currently Kbuild will
start to build Kconfig to let it show the error message.It would be more straightforward to check it in Makefile and let
it fail immediately.Signed-off-by: Masahiro Yamada
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If include/config/auto.conf.cmd is lost for some reasons, it is not
self-healing, so the top Makefile misses to run syncconfig.
Move include/config/auto.conf.cmd to the target side.I used a pattern rule instead of a normal rule here although it is
a bit gross.If the rule were written with a normal rule like this,
include/config/auto.conf \
include/config/auto.conf.cmd \
include/config/tristate.conf: $(KCONFIG_CONFIG)
$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig... syncconfig would be executed per target.
Using a pattern rule makes sure that syncconfig is executed just once
because Make assumes the recipe will create all of the targets.Here is a quote from the GNU Make manual [1]:
"Pattern rules may have more than one target. Unlike normal rules,
this does not act as many different rules with the same prerequisites
and recipe. If a pattern rule has multiple targets, make knows that
the rule's recipe is responsible for making all of the targets. The
recipe is executed only once to make all the targets. When searching
for a pattern rule to match a target, the target patterns of a rule
other than the one that matches the target in need of a rule are
incidental: make worries only about giving a recipe and prerequisites
to the file presently in question. However, when this file's recipe is
run, the other targets are marked as having been updated themselves."[1]: https://www.gnu.org/software/make/manual/html_node/Pattern-Intro.html
Signed-off-by: Masahiro Yamada
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The dependency will be checked anyway after Kbuild descends into a
sub-directory. Skip object/source dependency checks in top Makefile.VPATH can be simpler since the top Makefile no longer checks the
presence of the source file, which is located in in the external
module directory.One good thing is, it can compile an object from a generated source
file.$ make crypto/rsapubkey.asn1.o
...
ASN.1 crypto/rsapubkey.asn1.c
CC crypto/rsapubkey.asn1.oSigned-off-by: Masahiro Yamada
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The previous commit made 'MAKEFLAGS += -rR' effective in the top
Makefile regardless of O= option, GNU Make versions.The top Makefile does not need to cancel implicit rules for makefiles.
There is still one place where an empty rule is useful. Since -rR is
effective only after sub-make, GNU Make would try implicit rules to
update the top Makefile. Although it is not a big overhead, cancel it
just in case.Signed-off-by: Masahiro Yamada
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Adding -rR to MAKEFLAGS is important because we do not want to
be bothered by built-in implicit rules or variables.One problem that used to exist in older GNU Make versions is
MAKEFLAGS += -rR
... does not become effective in the current Makefile. When you are
building with O= option, it becomes effective in the top Makefile
since it recurses via 'sub-make' target. Otherwise, the top Makefile
tries implicit rules. That is why we explicitly add empty rules for
Makefiles, but we often miss to do that.In fact, adding -d option to older GNU Make versions shows it is
trying a bunch of implicit pattern rules.Considering target file `scripts/Makefile.kcov'.
Looking for an implicit rule for `scripts/Makefile.kcov'.
Trying pattern rule with stem `Makefile.kcov'.
Trying implicit prerequisite `scripts/Makefile.kcov.o'.
Trying pattern rule with stem `Makefile.kcov'.
Trying implicit prerequisite `scripts/Makefile.kcov.c'.
Trying pattern rule with stem `Makefile.kcov'.
Trying implicit prerequisite `scripts/Makefile.kcov.cc'.
Trying pattern rule with stem `Makefile.kcov'.
Trying implicit prerequisite `scripts/Makefile.kcov.C'.
...This issue was fixed by GNU Make commit 58dae243526b ("[Savannah #20501]
Handle adding -r/-R to MAKEFLAGS in the makefile"). So, it is no longer
a problem if you use GNU Make 4.0 or later. However, older versions are
still widely used.So, I decided to patch the kernel Makefile to invoke sub-make regardless
of O= option. This will allow further cleanups.Signed-off-by: Masahiro Yamada
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This would disturb the change the sub-make part. Move it near the
tools/ target.Signed-off-by: Masahiro Yamada
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Since -Wmaybe-uninitialized was introduced by GCC 4.7, we have patched
various false positives:- commit e74fc973b6e5 ("Turn off -Wmaybe-uninitialized when building
with -Os") turned off this option for -Os.- commit 815eb71e7149 ("Kbuild: disable 'maybe-uninitialized' warning
for CONFIG_PROFILE_ALL_BRANCHES") turned off this option for
CONFIG_PROFILE_ALL_BRANCHES- commit a76bcf557ef4 ("Kbuild: enable -Wmaybe-uninitialized warning
for "make W=1"") turned off this option for GCC < 4.9
Arnd provided more explanation in https://lkml.org/lkml/2017/3/14/903I think this looks better by shifting the logic from Makefile to Kconfig.
Link: https://github.com/ClangBuiltLinux/linux/issues/350
Signed-off-by: Masahiro Yamada
Reviewed-by: Nathan Chancellor
Tested-by: Nick Desaulniers -
The genksyms source was integrated into the kernel tree in 2003.
I do not expect anybody still using the external /sbin/genksyms.
Kbuild does not need to provide the ability to override GENKSYMS.Let's remove the GENKSYMS variable, and use the hardcoded path.
Since it occurred in the pre-git era, I attached the commit message
in case somebody is interested in the historical background.| Author: Kai Germaschewski
| Date: Wed Feb 19 04:17:28 2003 -0600
|
| kbuild: [PATCH] put genksyms in scripts dir
|
| This puts genksyms into scripts/genksyms/.
|
| genksyms used to be maintained externally, though the only possible user
| was the kernel build. Moving it into the kernel sources makes it easier to
| keep it uptodate, like for example updating it to generate linker scripts
| directly instead of postprocessing the generated header file fragments
| with sed, as we do currently.
|
| Also, genksyms does not handle __typeof__, which needs to be fixed since
| some of the exported symbol in the kernel are defined using __typeof__.
|
| (Rusty Russell/me)Signed-off-by: Masahiro Yamada
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It is weird to create gdb stuff as a side-effect of vmlinux.
Move it to a more relevant place.
Signed-off-by: Masahiro Yamada
Reviewed-by: Kieran Bingham -
Currently, Kbuild descends from scripts/Makefile to scripts/gdb/Makefile
just for creating symbolic links, but it does not need to do it so early.Merge the two descending paths to simplify the code.
Signed-off-by: Masahiro Yamada
Reviewed-by: Kieran Bingham -
scripts/gdb/linux/constants.py is never used in the kernel build
process. There is no good reason to create it so early.Get it out of the 'prepare' stage.
Signed-off-by: Masahiro Yamada
Reviewed-by: Kieran Bingham
25 Feb, 2019
1 commit
20 Feb, 2019
4 commits
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Commit 06300b21f4c7 ("kbuild: support building individual files for
external modules") introduced the '/' target. It works only for
external modules to build all .o files, but skip the modpost stage.However, 'make /' looks a bit weird to me. 'make ./' is more sensible
if you want to build all objects under the current directory, and it
works as expected.Let's change '/' into a phony target that is an alias of './', but
I may feel like deprecating it in the future.Signed-off-by: Masahiro Yamada
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It is fine to set KBUILD_MODULES=1 when CONFIG_MODULES is disabled.
It is actually how "make allnoconfig all" works.On the other hand, KBUILD_MODULES=1 is unneeded for the %.ko pattern.
It is just a matter of whether modules.order is generated or not.Signed-off-by: Masahiro Yamada
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This causes an issue when trying to build with `make LD=ld.lld` if
ld.lld and the rest of your cross tools aren't in the same directory
(ex. /usr/local/bin) (as is the case for Android's build system), as the
GCC_TOOLCHAIN_DIR then gets set based on `which $(LD)` which will point
where LLVM tools are, not GCC/binutils tools are located.Instead, select the GCC_TOOLCHAIN_DIR based on another tool provided by
binutils for which LLVM does not provide a substitute for, such as
elfedit.Fixes: 785f11aa595b ("kbuild: Add better clang cross build support")
Link: https://github.com/ClangBuiltLinux/linux/issues/341
Suggested-by: Nathan Chancellor
Reviewed-by: Nathan Chancellor
Tested-by: Nathan Chancellor
Signed-off-by: Nick Desaulniers
Signed-off-by: Masahiro Yamada -
Modern gcc adds view assignments, reset assertion checking in .loc
directives and a couple more additional debug markers, which clutters
the asm output unnecessarily:For example:
bsp_resume:
.LFB3466:
.loc 1 1868 1 is_stmt 1 view -0
.cfi_startproc
.loc 1 1869 2 view .LVU73
# arch/x86/kernel/cpu/common.c:1869: if (this_cpu->c_bsp_resume)
.loc 1 1869 14 is_stmt 0 view .LVU74
movq this_cpu(%rip), %rax # this_cpu, this_cpu
movq 64(%rax), %rax # this_cpu.94_1->c_bsp_resume, _2
# arch/x86/kernel/cpu/common.c:1869: if (this_cpu->c_bsp_resume)
.loc 1 1869 5 view .LVU75
testq %rax, %rax # _2
je .L8 #,
.loc 1 1870 3 is_stmt 1 view .LVU76
movq $boot_cpu_data, %rdi #,
jmp __x86_indirect_thunk_raxor
.loc 2 57 9 view .LVU478
.loc 2 57 9 view .LVU479
.loc 2 57 9 view .LVU480
.loc 2 57 9 view .LVU481
.LBB1385:
.LBB1383:
.LBB1379:
.LBB1377:
.LBB1375:
.loc 2 57 9 view .LVU482
.loc 2 57 9 view .LVU483
movl %edi, %edx # cpu, cpu
.LVL87:
.loc 2 57 9 is_stmt 0 view .LVU484That MOV in there is drowned in debugging information and latter makes
it hard to follow the asm. And that DWARF info is not really needed for
asm output staring.Disable the debug information generation which clutters the asm output
unnecessarily:bsp_resume:
# arch/x86/kernel/cpu/common.c:1869: if (this_cpu->c_bsp_resume)
movq this_cpu(%rip), %rax # this_cpu, this_cpu
movq 64(%rax), %rax # this_cpu.94_1->c_bsp_resume, _2
# arch/x86/kernel/cpu/common.c:1869: if (this_cpu->c_bsp_resume)
testq %rax, %rax # _2
je .L8 #,
# arch/x86/kernel/cpu/common.c:1870: this_cpu->c_bsp_resume(&boot_cpu_data);
movq $boot_cpu_data, %rdi #,
jmp __x86_indirect_thunk_rax
.L8:
# arch/x86/kernel/cpu/common.c:1871: }
rep ret
.size bsp_resume, .-bsp_resume[ bp: write commit message. ]
Signed-off-by: Masahiro Yamada
Signed-off-by: Borislav Petkov
19 Feb, 2019
1 commit
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When compiling into output directory using O=, many files
created under KBUILD_OUTPUT that git considers
as new ones; git clients, ex. "git gui" lists it, and it clutters
file list making it difficult to see what was really changedGenerate .gitignore in output directory that ignores all
its contentSigned-off-by: Vladimir Kondratiev
Signed-off-by: Masahiro Yamada
18 Feb, 2019
1 commit
11 Feb, 2019
2 commits
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We need the debugfs fixes in here as well.
Signed-off-by: Greg Kroah-Hartman
04 Feb, 2019
1 commit
28 Jan, 2019
3 commits
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There is no build order among the following:
prepare3
outputmakefile
asm-generic
$(version_h)
$(autoksyms_h)
include/generated/utsrelease.hIt is meaningless to insert the prepare2 target between the first
three and the last three.The comment says, "prepare2 creates a makefile if using a separate
output directory." Let me explain it more precisely. The prepare
targets cannot be executed without the .config file. Because the
configuration targets depend on the outputmakefile target, the
generated makefile is already there before the parepare2 is run.Signed-off-by: Masahiro Yamada
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The top Makefile does not need to export KBUILD_VMLINUX_INIT and
KBUILD_VMLINUX_MAIN separately.Put every built-in.a into KBUILD_VMLINUX_OBJS. The order of
$(head-y), $(init-y), $(core-y), ... is still retained.Signed-off-by: Masahiro Yamada
22 Jan, 2019
1 commit
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Currently, the 'firmware' directory only contains a single Makefile
to embed extra firmware into the kernel.Move it to the more relevant place.
Signed-off-by: Masahiro Yamada
Signed-off-by: Greg Kroah-Hartman
21 Jan, 2019
1 commit
17 Jan, 2019
1 commit
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Commit c3ff2a5193fa ("powerpc/32: add stack protector support")
caused kernel panic on PowerPC when an external module is used with
CONFIG_STACKPROTECTOR because the 'prepare' target was not executed
for the external module build.Commit e07db28eea38 ("kbuild: fix single target build for external
module") turned it into a build error because the 'prepare' target is
now executed but the 'prepare0' target is missing for the external
module build.External module on arm/arm64 with CONFIG_STACKPROTECTOR_PER_TASK is
also broken in the same way.Move 'PHONY += prepare0' to the common place. GNU Make is fine with
missing rule for phony targets. I also removed the comment which is
wrong irrespective of this commit.I minimize the change so it can be easily backported to 4.20.x
To fix v4.20, please backport e07db28eea38 ("kbuild: fix single target
build for external module"), and then this commit.Link: https://bugzilla.kernel.org/show_bug.cgi?id=201891
Fixes: e07db28eea38 ("kbuild: fix single target build for external module")
Fixes: c3ff2a5193fa ("powerpc/32: add stack protector support")
Fixes: 189af4657186 ("ARM: smp: add support for per-task stack canaries")
Fixes: 0a1213fa7432 ("arm64: enable per-task stack canaries")
Cc: linux-stable # v4.20
Reported-by: Samuel Holland
Reported-by: Alexey Kardashevskiy
Signed-off-by: Masahiro Yamada
Acked-by: Ard Biesheuvel
Tested-by: Alexey Kardashevskiy
16 Jan, 2019
1 commit
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No one uses archmrproper.
Signed-off-by: Masahiro Yamada
14 Jan, 2019
1 commit