- 52-bit virtual addressing in the kernel
- New ABI to allow tagged user pointers to be dereferenced by syscalls
- Early RNG seeding by the bootloader
- Improve robustness of SMP boot
- Fix TLB invalidation in light of recent architectural clarifications
- Support for i.MX8 DDR PMU
- Remove direct LSE instruction patching in favour of static keys
- Function error injection using kprobes
- Support for the PPTT "thread" flag introduced by ACPI 6.3
- Move PSCI idle code into proper cpuidle driver
- Relaxation of implicit I/O memory barriers
- Build with RELR relocations when toolchain supports them
- Numerous cleanups and non-critical fixes
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon:
"Although there isn't tonnes of code in terms of line count, there are
a fair few headline features which I've noted both in the tag and also
in the merge commits when I pulled everything together.
The part I'm most pleased with is that we had 35 contributors this
time around, which feels like a big jump from the usual small group of
core arm64 arch developers. Hopefully they all enjoyed it so much that
they'll continue to contribute, but we'll see.
It's probably worth highlighting that we've pulled in a branch from
the risc-v folks which moves our CPU topology code out to where it can
be shared with others.
Summary:
- 52-bit virtual addressing in the kernel
- New ABI to allow tagged user pointers to be dereferenced by
syscalls
- Early RNG seeding by the bootloader
- Improve robustness of SMP boot
- Fix TLB invalidation in light of recent architectural
clarifications
- Support for i.MX8 DDR PMU
- Remove direct LSE instruction patching in favour of static keys
- Function error injection using kprobes
- Support for the PPTT "thread" flag introduced by ACPI 6.3
- Move PSCI idle code into proper cpuidle driver
- Relaxation of implicit I/O memory barriers
- Build with RELR relocations when toolchain supports them
- Numerous cleanups and non-critical fixes"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (114 commits)
arm64: remove __iounmap
arm64: atomics: Use K constraint when toolchain appears to support it
arm64: atomics: Undefine internal macros after use
arm64: lse: Make ARM64_LSE_ATOMICS depend on JUMP_LABEL
arm64: asm: Kill 'asm/atomic_arch.h'
arm64: lse: Remove unused 'alt_lse' assembly macro
arm64: atomics: Remove atomic_ll_sc compilation unit
arm64: avoid using hard-coded registers for LSE atomics
arm64: atomics: avoid out-of-line ll/sc atomics
arm64: Use correct ll/sc atomic constraints
jump_label: Don't warn on __exit jump entries
docs/perf: Add documentation for the i.MX8 DDR PMU
perf/imx_ddr: Add support for AXI ID filtering
arm64: kpti: ensure patched kernel text is fetched from PoU
arm64: fix fixmap copy for 16K pages and 48-bit VA
perf/smmuv3: Validate groups for global filtering
perf/smmuv3: Validate group size
arm64: Relax Documentation/arm64/tagged-pointers.rst
arm64: kvm: Replace hardcoded '1' with SYS_PAR_EL1_F
arm64: mm: Ignore spurious translation faults taken from the kernel
...
A script that uses the '<module>.ns_deps' files generated by modpost to
automatically add the required symbol namespace dependencies to each
module.
Usage:
1) Move some symbols to a namespace with EXPORT_SYMBOL_NS() or define
DEFAULT_SYMBOL_NAMESPACE
2) Run 'make' (or 'make modules') and get warnings about modules not
importing that namespace.
3) Run 'make nsdeps' to automatically add required import statements
to said modules.
This makes it easer for subsystem maintainers to introduce and maintain
symbol namespaces into their codebase.
Co-developed-by: Martijn Coenen <maco@android.com>
Signed-off-by: Martijn Coenen <maco@android.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
This patch adds an option to modpost to generate a <module>.ns_deps file
per module, containing the namespace dependencies for that module.
E.g. if the linked module my-module.ko would depend on the symbol
myfunc.MY_NS in the namespace MY_NS, the my-module.ns_deps file created
by modpost would contain the entry MY_NS to express the namespace
dependency of my-module imposed by using the symbol myfunc.
These files can subsequently be used by static analysis tools (like
coccinelle scripts) to address issues with missing namespace imports. A
later patch of this series will introduce such a script 'nsdeps' and a
corresponding make target to automatically add missing
MODULE_IMPORT_NS() definitions to the module's sources. For that it uses
the information provided in the generated .ns_deps files.
Co-developed-by: Martijn Coenen <maco@android.com>
Signed-off-by: Martijn Coenen <maco@android.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
KBUILD_ENABLE_EXTRA_GCC_CHECKS started as a switch to add extra warning
options for GCC, but now it is a historical misnomer since we use it
also for Clang, DTC, and even kernel-doc.
Rename it to more sensible, shorter KBUILD_EXTRA_WARN.
For the backward compatibility, KBUILD_ENABLE_EXTRA_GCC_CHECKS is still
supported (but not advertised in the documentation).
I also fixed up 'make help', and updated the documentation.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Sedat Dilek <sedat.dilek@gmail.com>
CONFIG_SHELL falls back to sh when bash is not installed on the system,
but nobody is testing such a case since bash is usually installed.
So, shell scripts invoked by CONFIG_SHELL are only tested with bash.
It makes it difficult to test whether the hashbang #!/bin/sh is real.
For example, #!/bin/sh in arch/powerpc/kernel/prom_init_check.sh is
false. (I fixed it up)
Besides, some shell scripts invoked by CONFIG_SHELL use bash-extension
and #!/bin/bash is specified as the hashbang, while CONFIG_SHELL may
not always be set to bash.
Probably, the right thing to do is to introduce BASH, which is bash by
default, and always set CONFIG_SHELL to sh. Replace $(CONFIG_SHELL)
with $(BASH) for bash scripts.
If somebody tries to add bash-extension to a #!/bin/sh script, it will
be caught in testing because /bin/sh is a symlink to dash on some major
distributions.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
These flags were added by commit 61754c1875 ("kbuild: Allow arch
Makefiles to override {cpp,ld,c}flags") to allow ARC to override -O2.
We did not see any other usage after all. Now that ARC switched to
CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3, there is no more user of
these variables.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
arch/arc/Makefile overrides -O2 with -O3. This is the only user of
ARCH_CFLAGS. There is no user of ARCH_CPPFLAGS or ARCH_AFLAGS.
My plan is to remove ARCH_{CPP,A,C}FLAGS after refactoring the ARC
Makefile.
Currently, ARC has no way to enable -Wmaybe-uninitialized because both
-O3 and -Os disable it. Enabling it will be useful for compile-testing.
This commit allows allmodconfig (, which defaults to -O2) to enable it.
Add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y to all the defconfig files
in arch/arc/configs/ in order to keep the current config settings.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
This functionally reverts commit bfd77145f3 ("Makefile: Convert
-Wimplicit-fallthrough=3 to just -Wimplicit-fallthrough for clang").
clang enabled support for -Wimplicit-fallthrough in C in r369414 [1],
which causes a lot of warnings when building the kernel for two reasons:
1. Clang does not support the /* fall through */ comments. There seems
to be a general consensus in the LLVM community that this is not
something they want to support. Joe Perches wrote a script to convert
all of the comments to a "fallthrough" keyword that will be added to
compiler_attributes.h [2] [3], which catches the vast majority of the
comments. There doesn't appear to be any consensus in the kernel
community when to do this conversion.
2. Clang and GCC disagree about falling through to final case statements
with no content or cases that simply break:
https://godbolt.org/z/c8csDu
This difference contributes at least 50 warnings in an allyesconfig
build for x86, not considering other architectures. This difference
will need to be discussed to see which compiler is right [4] [5].
[1]: 1e0affb6e5
[2]: https://lore.kernel.org/lkml/61ddbb86d5e68a15e24ccb06d9b399bbf5ce2da7.camel@perches.com/
[3]: https://lore.kernel.org/lkml/1d2830aadbe9d8151728a7df5b88528fc72a0095.1564549413.git.joe@perches.com/
[4]: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91432
[5]: https://github.com/ClangBuiltLinux/linux/issues/636
Given these two problems need discussion and coordination, do not enable
-Wimplicit-fallthrough with clang right now. Add a comment to explain
what is going on as well. This commit should be reverted once these two
issues are fully flushed out and resolved.
Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Move the outputmakefile target to the leftmost in the prerequisite list
so that this is checked first. GNU Make processes the prerequisites
left to right.
GNU Make will keep to stick to this behavior, and it seems even
POSIX standard, according to this:
https://lists.gnu.org/archive/html/bug-make/2019-08/msg00030.html
The POSIX standard of make is available here:
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/make.html
Of course, when the parallel option -j given, other targets will be run
simultaneously but it is nice to show the error as early as possible.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
If you try out-of-tree build with an unclean source tree, Kbuild
suggests to run make mrproper. The path to the source tree may be
shown with a relative path, for example, "make O=foo" emits the
following:
.. is not clean, please run 'make mrproper'
in the '..' directory.
This is somewhat confusing if you ran "make O=foo" in the source tree.
Using the absolute path will be clearer.
This commit changes the error message like follows:
***
*** The source tree is not clean, please run 'make mrproper'
*** in /absolute/path/to/linux
***
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Since commit 3a475b2166 ("kbuild: Inform user to pass ARCH= for make
mrproper"), if you try out-of-tree build with an unclean source tree,
it suggests to run 'make ARCH=<ARCH> mrproper'.
This looks odd when you are not cross-compiling the kernel. Show the
'ARCH=<ARCH>' part only when ARCH= was given from the command line.
If ARCH is the default (native build) or came from the environment,
it should simply suggest 'make mrproper' as before.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Commit 415008af32 ("docs-rst: convert lsm from DocBook to ReST")
stopped using if_changed_rule. There is no more users of if_changed*
for the doc targets. Hence, fixdep is unneeded. Remove the dependency
on scripts_basic.
All the doc targets are phony. The dependency on FORCE is not needed
either.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This line contains $(MAKE), so Make knows that it will invoke sub-make
without help of the '+' marker.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
scripts/package/Makefile does not use $(obj) or $(src) at all.
It actually generates files and directories in the top of $(objtree).
I do not see much sense in descending into scripts/package/.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
I am not a big fan of the $(objtree)/ hack for clean-files/clean-dirs.
These are created in the top of $(objtree), so let's clean them up
from the top Makefile.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
I think splitting the modpost and linking modules into separate
Makefiles will be useful especially when more complex build steps
come in. The main motivation of this commit is to integrate the
proposed klp-convert feature cleanly.
I moved the logging 'Building modules, stage 2.' to Makefile.modpost
to avoid the code duplication although I do not know whether or not
this message is needed in the first place.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Currently, the timestamp of module linker scripts are not checked.
Add them to the dependency of modules so they are correctly rebuilt.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Currently, the single target build directly descends into the directory
of the target. For example,
$ make foo/bar/baz.o
... directly descends into foo/bar/.
On the other hand, the normal build usually descends one directory at
a time, i.e. descends into foo/, and then foo/bar/.
This difference causes some problems.
[1] miss subdir-asflags-y, subdir-ccflags-y in upper Makefiles
The options in subdir-{as,cc}flags-y take effect in the current
and its sub-directories. In other words, they are inherited
downward. In the example above, the single target will miss
subdir-{as,cc}flags-y if they are defined in foo/Makefile.
[2] could be built in a different directory
As Documentation/kbuild/modules.rst section 4.3 says, Kbuild can
handle files that are spread over several sub-directories.
The build rule of foo/bar/baz.o may not necessarily be specified in
foo/bar/Makefile. It might be specifies in foo/Makefile as follows:
[foo/Makefile]
obj-y := bar/baz.o
This often happens when a module is so big that its source files
are divided into sub-directories.
In this case, there is no Makefile in the foo/bar/ directory, yet
the single target descends into foo/bar/, then fails due to the
missing Makefile. You can still do 'make foo/bar/' for partial
building, but cannot do 'make foo/bar/baz.s'. I believe the single
target '%.s' is a useful feature for inspecting the compiler output.
Some modules work around this issue by putting an empty Makefile
in every sub-directory.
This commit fixes those problems by making the single target build
descend in the same way as the normal build does.
Another change is the single target build will observe the CONFIG
options. Previously, it allowed users to build the foo.o even when
the corresponding CONFIG_FOO is disabled:
obj-$(CONFIG_FOO) += foo.o
In the new behavior, the single target build will just fail and show
"No rule to make target ..." (or "Nothing to be done for ..." if the
stale object already exists, but cannot be updated).
The disadvantage of this commit is the build speed. Now that the
single target build visits every directory and parses lots of
Makefiles, it is slower than before. (But, I hope it will not be
too slow.)
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
The in-kernel build and external module build have similar code
for descending into sub-directories.
Factor out the code into the common place.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
There is no need to set 0 to variables such as config-targets,
mixed-targets, etc.
Unset instead of setting 0 in order to use 'ifdef' to test them.
I also renamed:
config-targets -> config-build
mixed-targets -> mixed-build
dot-config -> need-config
to clarify what we are doing.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
'make clean' descends into ./Kbuild, but does not clean anything
since everything is added to no-clean-files.
There is no need to descend to ./Kbuild in the first place.
We can drop the no-clean-files assignment.
With this, there is no more user of no-clean-files. I will keep it
for a while to see whether a new user will appear.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
'make /' is just an alias for 'make ./'; this builds all objects of an
external module, but skips the modpost stage.
I am not a big fan of 'make /' since it looks as if it were touching
the root directory of the system. I like 'make ./' better.
I do not know how many people are using it, but let's show a hint if
it is used. Also, move it close to the external module rules since
this only makes sense for external modules.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
$(objtree)/Module.symvers is not required for descending into
sub-directories. It is needed for the modpost stage.
Move the Module.symvers check to the right place.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
It wasn't obvious that this was a command to run based on 'make help',
so add it to the top-level help for devicetree builds. Also, add an
example to the documentation to show that db_binding_check can be run
with DT_SCHEMA_FILES= to only check one schema file instead of all of
them.
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: <linux-kbuild@vger.kernel.org>
Cc: <devicetree@vger.kernel.org>
Cc: <linux-doc@vger.kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
[robh: fix-up due to .md to .rst conversion]
Signed-off-by: Rob Herring <robh@kernel.org>
A compilation -Wimplicit-fallthrough warning was enabled by commit
a035d552a9 ("Makefile: Globally enable fall-through warning")
Even though clang 10.0.0 does not currently support this warning without
a patch, clang currently does not support a value for this option.
Link: https://bugs.llvm.org/show_bug.cgi?id=39382
The gcc default for this warning is 3 so removing the =3 has no effect
for gcc and enables the warning for patched versions of clang.
Also remove the =3 from an existing use in a parisc Makefile:
arch/parisc/math-emu/Makefile
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-and-tested-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- revive single target %.ko
- do not create built-in.a where it is unneeded
- do not create modules.order where it is unneeded
- show a warning if subdir-y/m is used to visit a module Makefile
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Merge tag 'kbuild-fixes-v5.3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- revive single target %.ko
- do not create built-in.a where it is unneeded
- do not create modules.order where it is unneeded
- show a warning if subdir-y/m is used to visit a module Makefile
* tag 'kbuild-fixes-v5.3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: show hint if subdir-y/m is used to visit module Makefile
kbuild: generate modules.order only in directories visited by obj-y/m
kbuild: fix false-positive need-builtin calculation
kbuild: revive single target %.ko
Since commit ff9b45c55b ("kbuild: modpost: read modules.order instead
of $(MODVERDIR)/*.mod"), a module is no longer built in the following
pattern:
[Makefile]
subdir-y := some-module
[some-module/Makefile]
obj-m := some-module.o
You cannot write Makefile this way in upstream because modules.order is
not correctly generated. subdir-y is used to descend to a sub-directory
that builds tools, device trees, etc.
For external modules, the modules order does not matter. So, the
Makefile above was known to work.
I believe the Makefile should be re-written as follows:
[Makefile]
obj-m := some-module/
[some-module/Makefile]
obj-m := some-module.o
However, people will have no idea if their Makefile suddenly stops
working. In fact, I received questions from multiple people.
Show a warning for a while if obj-m is specified in a Makefile visited
by subdir-y or subdir-m.
I touched the %/ rule to avoid false-positive warnings for the single
target.
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Tom Stonecypher <thomas.edwardx.stonecypher@intel.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
I removed the single target %.ko in commit ff9b45c55b ("kbuild:
modpost: read modules.order instead of $(MODVERDIR)/*.mod") because
the modpost stage does not work reliably. For instance, the module
dependency, modversion, etc. do not work if we lack symbol information
from the other modules.
Yet, some people still want to build only one module in their interest,
and it may be still useful if it is used within those limitations.
Fixes: ff9b45c55b ("kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod")
Reported-by: Don Brace <don.brace@microsemi.com>
Reported-by: Arend Van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Define and export OBJSIZE variable for "size" tool from binutils to be
used in architecture specific Makefiles (naming the variable just "SIZE"
would be too risky). In particular this tool is useful to perform checks
that early boot code is not using bss section (which might have not been
zeroed yet or intersects with initrd or other files boot loader might
have put right after the linux kernel).
Link: http://lkml.kernel.org/r/patch-1.thread-2257a1.git-188f5a3d81d5.your-ad-here.call-01565088755-ext-5120@work.hours
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
RELR is a relocation packing format for relative relocations.
The format is described in a generic-abi proposal:
https://groups.google.com/d/topic/generic-abi/bX460iggiKg/discussion
The LLD linker can be instructed to pack relocations in the RELR
format by passing the flag --pack-dyn-relocs=relr.
This patch adds a new config option, CONFIG_RELR. Enabling this option
instructs the linker to pack vmlinux's relative relocations in the RELR
format, and causes the kernel to apply the relocations at startup along
with the RELA relocations. RELA relocations still need to be applied
because the linker will emit RELA relative relocations if they are
unrepresentable in the RELR format (i.e. address not a multiple of 2).
Enabling CONFIG_RELR reduces the size of a defconfig kernel image
with CONFIG_RANDOMIZE_BASE by 3.5MB/16% uncompressed, or 550KB/5%
compressed (lz4).
Signed-off-by: Peter Collingbourne <pcc@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
CLANG_FLAGS is initialized by the following line:
CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE:%-=%))
..., which is run only when CROSS_COMPILE is set.
Some build targets (bindeb-pkg etc.) recurse to the top Makefile.
When you build the kernel with Clang but without CROSS_COMPILE,
the same compiler flags such as -no-integrated-as are accumulated
into CLANG_FLAGS.
If you run 'make CC=clang' and then 'make CC=clang bindeb-pkg',
Kbuild will recompile everything needlessly due to the build command
change.
Fix this by correctly initializing CLANG_FLAGS.
Fixes: 238bcbc4e0 ("kbuild: consolidate Clang compiler flags")
Cc: <stable@vger.kernel.org> # v5.0+
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Now that all the fall-through warnings have been addressed in the
kernel, enable the fall-through warning globally.
Also, update the deprecated.rst file to include implicit fall-through
as 'deprecated' so people can be pointed to a single location for
justification.
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The gcc -fcf-protection=branch option is not compatible with
-mindirect-branch=thunk-extern. The latter is used when
CONFIG_RETPOLINE is selected, and this will fail to build with
a gcc which has -fcf-protection=branch enabled by default. Adding
-fcf-protection=none when building with retpoline enabled
prevents such build failures.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
While descending directories, Kbuild produces objects for modules,
but do not link final *.ko files; it is done in the modpost.
To keep track of modules, Kbuild creates a *.mod file in $(MODVERDIR)
for every module it is building. Some post-processing steps read the
necessary information from *.mod files. This avoids descending into
directories again. This mechanism was introduced in 2003 or so.
Later, commit 551559e13a ("kbuild: implement modules.order") added
modules.order. So, we can simply read it out to know all the modules
with directory paths. This is easier than parsing the first line of
*.mod files.
$(MODVERDIR) has a flat directory structure, that is, *.mod files
are named only with base names. This is based on the assumption that
the module name is unique across the tree. This assumption is really
fragile.
Stephen Rothwell reported a race condition caused by a module name
conflict:
https://lkml.org/lkml/2019/5/13/991
In parallel building, two different threads could write to the same
$(MODVERDIR)/*.mod simultaneously.
Non-unique module names are the source of all kind of troubles, hence
commit 3a48a91901 ("kbuild: check uniqueness of module names")
introduced a new checker script.
However, it is still fragile in the build system point of view because
this race happens before scripts/modules-check.sh is invoked. If it
happens again, the modpost will emit unclear error messages.
To fix this issue completely, create *.mod with full directory path
so that two threads never attempt to write to the same file.
$(MODVERDIR) is no longer needed.
Since modules with directory paths are listed in modules.order, Kbuild
is still able to find *.mod files without additional descending.
I also killed cmd_secanalysis; scripts/mod/sumversion.c computes MD4 hash
for modules with MODULE_VERSION(). When CONFIG_DEBUG_SECTION_MISMATCH=y,
it occurs not only in the modpost stage, but also during directory
descending, where sumversion.c may parse stale *.mod files. It would emit
'No such file or directory' warning when an object consisting a module is
renamed, or when a single-obj module is turned into a multi-obj module or
vice versa.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Towards the goal of removing MODVERDIR, read out modules.order to get
the list of modules to be processed. This is simpler than parsing *.mod
files in $(MODVERDIR).
For external modules, $(KBUILD_EXTMOD)/modules.order should be read.
I removed the single target %.ko from the top Makefile. To make sure
modpost works correctly, vmlinux and the other modules must be built.
You cannot build a particular .ko file alone.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Removing the 'kernel/' prefix will make our life easier because we can
simply do 'cat modules.order' to get all built modules with full paths.
Currently, we parse the first line of '*.mod' files in $(MODVERDIR).
Since we have duplicated functionality here, I plan to remove MODVERDIR
entirely.
In fact, modules.order is generated also for external modules in a
broken format. It adds the 'kernel/' prefix to the absolute path of
the module, like this:
kernel//path/to/your/external/module/foo.ko
This is fine for now since modules.order is not used for external
modules. However, I want to sanitize the format everywhere towards
the goal of removing MODVERDIR.
We cannot change the format of installed module.{order,builtin}.
So, 'make modules_install' will add the 'kernel/' prefix while copying
them to $(MODLIB)/.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Currently, $(objtree)/modules.order is touched in two places.
In the 'prepare0' rule, scripts/Makefile.build creates an empty
modules.order while processing 'obj=.'
In the 'modules' rule, the top-level Makefile overwrites it with
the correct list of modules.
While this might be a good side-effect that modules.order is made
empty every time (probably this is not intended functionality),
I personally do not like this behavior.
Create modules.order only when it is sensible to do so.
This avoids creating the following pointless files:
scripts/basic/modules.order
scripts/dtc/modules.order
scripts/gcc-plugins/modules.order
scripts/genksyms/modules.order
scripts/mod/modules.order
scripts/modules.order
scripts/selinux/genheaders/modules.order
scripts/selinux/mdp/modules.order
scripts/selinux/modules.order
Going forward, $(objtree)/modules.order lists the modules that
was built in the last successful build.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
It takes somewhat long time to generate these tag files.
Keep such precious files until we run 'make distclean'.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
As commit 1e0221374e ("mips: vdso: drop unnecessary cc-ldoption")
explained, these flags are supported by the minimal required version
of binutils. They are supported by ld.lld too.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
- remove headers_{install,check}_all targets
- remove unreasonable 'depends on !UML' from CONFIG_SAMPLES
- re-implement 'make headers_install' more cleanly
- add new header-test-y syntax to compile-test headers
- compile-test exported headers to ensure they are compilable in
user-space
- compile-test headers under include/ to ensure they are self-contained
- remove -Waggregate-return, -Wno-uninitialized, -Wno-unused-value flags
- add -Werror=unknown-warning-option for Clang
- add 128-bit built-in types support to genksyms
- fix missed rebuild of modules.builtin
- propagate 'No space left on device' error in fixdep to Make
- allow Clang to use its integrated assembler
- improve some coccinelle scripts
- add a new flag KBUILD_ABS_SRCTREE to request Kbuild to use absolute
path for $(srctree).
- do not ignore errors when compression utility is missing
- misc cleanups
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Merge tag 'kbuild-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- remove headers_{install,check}_all targets
- remove unreasonable 'depends on !UML' from CONFIG_SAMPLES
- re-implement 'make headers_install' more cleanly
- add new header-test-y syntax to compile-test headers
- compile-test exported headers to ensure they are compilable in
user-space
- compile-test headers under include/ to ensure they are self-contained
- remove -Waggregate-return, -Wno-uninitialized, -Wno-unused-value
flags
- add -Werror=unknown-warning-option for Clang
- add 128-bit built-in types support to genksyms
- fix missed rebuild of modules.builtin
- propagate 'No space left on device' error in fixdep to Make
- allow Clang to use its integrated assembler
- improve some coccinelle scripts
- add a new flag KBUILD_ABS_SRCTREE to request Kbuild to use absolute
path for $(srctree).
- do not ignore errors when compression utility is missing
- misc cleanups
* tag 'kbuild-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (49 commits)
kbuild: use -- separater intead of $(filter-out ...) for cc-cross-prefix
kbuild: Inform user to pass ARCH= for make mrproper
kbuild: fix compression errors getting ignored
kbuild: add a flag to force absolute path for srctree
kbuild: replace KBUILD_SRCTREE with boolean building_out_of_srctree
kbuild: remove src and obj from the top Makefile
scripts/tags.sh: remove unused environment variables from comments
scripts/tags.sh: drop SUBARCH support for ARM
kbuild: compile-test kernel headers to ensure they are self-contained
kheaders: include only headers into kheaders_data.tar.xz
kheaders: remove meaningless -R option of 'ls'
kbuild: support header-test-pattern-y
kbuild: do not create wrappers for header-test-y
kbuild: compile-test exported headers to ensure they are self-contained
init/Kconfig: add CONFIG_CC_CAN_LINK
kallsyms: exclude kasan local symbols on s390
kbuild: add more hints about SUBDIRS replacement
coccinelle: api/stream_open: treat all wait_.*() calls as blocking
coccinelle: put_device: Add a cast to an expression for an assignment
coccinelle: put_device: Adjust a message construction
...
When cross-compiling an out-of-tree build with an unclean source tree
directory, the build fails with:
/path/to/kernel/source/tree is not clean, please run 'make mrproper'
in the '/path/to/kernel/source/tree' directory.
However, doing so does not fix the problem, as "make mrproper" now
requires passing the target architecture to the make command, else it
won't remove $(srctree)/arch/$(SRCARCH)/include/generated.
"git ls-files -o" doesn't give a clue, as it doesn't list (empty)
directories, only files.
Improve usability by including the ARCH= option in the error output.
Fixes: a788b2ed81 ("kbuild: check arch/$(SRCARCH)/include/generated before out-of-tree build")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
In old days, Kbuild always used an absolute path for $(srctree).
Since commit 890676c65d ("kbuild: Use relative path when building in
the source tree"), $(srctree) is '.' when O= was not passed from the
command line.
Yet, using absolute paths is useful in some cases even without O=, for
instance, to create a cscope file with absolute path tags.
'O=.' was known to work as a workaround to force Kbuild to use absolute
paths even when you are building in the source tree.
Since commit 25b146c5b8 ("kbuild: allow Kbuild to start from any
directory"), Kbuild is too clever to be tricked. Even if you pass 'O=.'
Kbuild notices you are building in the source tree, then use '.' for
$(srctree).
So, 'make O=. cscope' is no help to create absolute path tags.
We cannot force one or the other according to commit e93bc1a0ca
("Revert "kbuild: specify absolute paths for cscope""). Both of
relative path and absolute path have pros and cons.
This commit adds a new flag KBUILD_ABS_SRCTREE to allow users to
choose the absolute path for $(srctree).
'make KBUILD_ABS_SRCTREE=1 cscope' will work as a replacement of
'make O=. cscope'.
Reported-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Commit 25b146c5b8 ("kbuild: allow Kbuild to start from any directory")
deprecated KBUILD_SRCTREE.
It is only used in tools/testing/selftest/ to distinguish out-of-tree
build. Replace it with a new boolean flag, building_out_of_srctree.
I also replaced the conditional ($(srctree),.) because the next commit
will allow an absolute path to be used for $(srctree) even when building
in the source tree.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
The headers in include/ are globally used in the kernel source tree
to provide common APIs. They are included from external modules, too.
It will be useful to make as many headers self-contained as possible
so that we do not have to rely on a specific include order.
There are more than 4000 headers in include/. In my rough analysis,
70% of them are already self-contained. With efforts, most of them
can be self-contained.
For now, we must exclude more than 1000 headers just because they
cannot be compiled as standalone units. I added them to header-test-.
The blacklist was mostly generated by a script, so the reason of the
breakage should be checked later.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
header-test-y does not work with headers in sub-directories.
For example, you may want to write a Makefile, like this:
include/linux/Kbuild:
header-test-y += mtd/nand.h
This entry will create a wrapper include/linux/mtd/nand.hdrtest.c
with the following content:
#include "mtd/nand.h"
To make this work, we need to add $(srctree)/include/linux to the
header search path. It would be tedious to add ccflags-y.
Instead, we could change the *.hdrtest.c rule to wrap:
#include "nand.h"
This works for in-tree build since #include "..." searches in the
relative path from the header with this directive. For O=... build,
we need to add $(srctree)/include/linux/mtd to the header search path,
which will be even more tedious.
After all, I thought it would be handier to compile headers directly
without creating wrappers.
I added a new build rule to compile %.h into %.h.s
The target is %.h.s instead of %.h.o because it is slightly faster.
Also, as for GCC, an empty assembly is smaller than an empty object.
I wrote the build rule:
$(CC) $(c_flags) -S -o $@ -x c /dev/null -include $<
instead of:
$(CC) $(c_flags) -S -o $@ -x c $<
Both work fine with GCC, but the latter is bad for Clang.
This comes down to the difference in the -Wunused-function policy.
GCC does not warn about unused 'static inline' functions at all.
Clang does not warn about the ones in included headers, but does
about the ones in the source. So, we should handle headers as
headers, not as source files.
In fact, this has been hidden since commit abb2ea7dfd ("compiler,
clang: suppress warning for unused static inline functions"), but we
should not rely on that.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: Jani Nikula <jani.nikula@intel.com>
Multiple people have suggested compile-testing UAPI headers to ensure
they can be really included from user-space. "make headers_check" is
obviously not enough to catch bugs, and we often leak unresolved
references to user-space.
Use the new header-test-y syntax to implement it. Please note exported
headers are compile-tested with a completely different set of compiler
flags. The header search path is set to $(objtree)/usr/include since
exported headers should not include unexported ones.
We use -std=gnu89 for the kernel space since the kernel code highly
depends on GNU extensions. On the other hand, UAPI headers should be
written in more standardized C, so they are compiled with -std=c90.
This will emit errors if C++ style comments, the keyword 'inline', etc.
are used. Please use C style comments (/* ... */), '__inline__', etc.
in UAPI headers.
There is additional compiler requirement to enable this test because
many of UAPI headers include <stdlib.h>, <sys/ioctl.h>, <sys/time.h>,
etc. directly or indirectly. You cannot use kernel.org pre-built
toolchains [1] since they lack <stdlib.h>.
I reused CONFIG_CC_CAN_LINK to check the system header availability.
The intention is slightly different, but a compiler that can link
userspace programs provide system headers.
For now, a lot of headers need to be excluded because they cannot
be compiled standalone, but this is a good start point.
[1] https://mirrors.edge.kernel.org/pub/tools/crosstool/index.html
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Commit 0126be38d9 ("kbuild: announce removal of SUBDIRS if used")
added a hint about the 'SUBDIRS' replacement, but it was not clear
enough.
Multiple people sent me similar questions, patches. For instance,
https://lkml.org/lkml/2019/1/17/456
I did not mean to use M= for building a subdirectory in the kernel tree.
From commit 669efc76b3 ("net: hns3: fix compile error"), people
already (ab)use M=... to do that because it seems to work to some extent.
Documentation/kbuild/kbuild.txt says M= and KBUILD_EXTMOD are used for
building external modules.
In fact, Kbuild supports the single target '%/' for this purpose, but
this may not be noticed much.
Kindly add more hints.
Makefile:213: ================= WARNING ================
Makefile:214: 'SUBDIRS' will be removed after Linux 5.3
Makefile:215:
Makefile:216: If you are building an individual subdirectory
Makefile:217: in the kernel tree, you can do like this:
Makefile:218: $ make path/to/dir/you/want/to/build/
Makefile:219: (Do not forget the trailing slash)
Makefile:220:
Makefile:221: If you are building an external module,
Makefile:222: Please use 'M=' or 'KBUILD_EXTMOD' instead
Makefile:223: ==========================================
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
There are some people interested in experimenting with Clang's
integrated assembler. To make it easy to do so without source
modification, allow the user to specify 'AS=clang' as part of the
make command to avoid adding '-no-integrated-as' to the {A,C}FLAGS.
Link: https://github.com/ClangBuiltLinux/linux/issues/577
Suggested-by: Dmitry Golovin <dima@golovin.in>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Unlike modules.order, modules.builtin is not rebuilt every time.
Once modules.builtin is created, it will not be updated until
auto.conf or tristate.conf is changed.
So, it does not notice a change in Makefile, for example, the rename
of modules.
Kbuild must always descend into directories for modules.builtin too.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
In commit ebcc5928c5 ("arm64: Silence gcc warnings about arch ABI
drift"), the arm64 Makefile added -Wno-psabi to KBUILD_CFLAGS, which is
a GCC only option so clang rightfully complains:
warning: unknown warning option '-Wno-psabi' [-Wunknown-warning-option]
https://clang.llvm.org/docs/DiagnosticsReference.html#wunknown-warning-option
However, by default, this is merely a warning so the build happily goes
on with a slew of these warnings in the process.
Commit c3f0d0bc5b ("kbuild, LLVMLinux: Add -Werror to cc-option to
support clang") worked around this behavior in cc-option by adding
-Werror so that unknown flags cause an error. However, this all happens
silently and when an unknown flag is added to the build unconditionally
like -Wno-psabi, cc-option will always fail because there is always an
unknown flag in the list of flags. This manifested as link time failures
in the arm64 libstub because -fno-stack-protector didn't get added to
KBUILD_CFLAGS.
To avoid these weird cryptic failures in the future, make clang behave
like gcc and immediately error when it encounters an unknown flag by
adding -Werror=unknown-warning-option to CLANG_FLAGS. This can be added
unconditionally for clang because it is supported by at least 3.0.0,
according to godbolt [1] and 4.0.0, according to its documentation [2],
which is far earlier than we typically support.
[1]: https://godbolt.org/z/7F7rm3
[2]: https://releases.llvm.org/4.0.0/tools/clang/docs/DiagnosticsReference.html#wunknown-warning-option
Link: https://github.com/ClangBuiltLinux/linux/issues/511
Link: https://github.com/ClangBuiltLinux/linux/issues/517
Suggested-by: Peter Smith <peter.smith@linaro.org>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Sometimes it's useful to be able to explicitly ensure certain headers
remain self-contained, i.e. that they are compilable as standalone
units, by including and/or forward declaring everything they depend on.
Add special target header-test-y where individual Makefiles can add
headers to be tested if CONFIG_HEADER_TEST is enabled. This will
generate a dummy C file per header that gets built as part of extra-y.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Now that hdr-inst is used only in the top Makefile, move it there
from scripts/Kbuild.include.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Since commit fcc8487d47 ("uapi: export all headers under uapi
directories"), the headers in uapi directories are all exported by
default although exceptional cases are still allowed by the syntax
'no-export-headers'.
The traditional directory descending has been kept (in a somewhat
hacky way), but it is actually unneeded.
Get rid of it to simplify the code.
Also, handle files one by one instead of the previous per-directory
processing. This will emit much more log, but I like it.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
In Linux build system, build targets and installation targets are
separated.
Examples are:
- 'make vmlinux' -> 'make install'
- 'make modules' -> 'make modules_install'
- 'make dtbs' -> 'make dtbs_install'
- 'make vdso' -> 'make vdso_install'
The intention is to run the build targets under the normal privilege,
then the installation targets under the root privilege since we need
the write permission to the system directories.
We have 'make headers_install' but the corresponding 'make headers'
stage does not exist. The purpose of headers_install is to provide
the kernel interface to C library. So, nobody would try to install
headers to /usr/include directly.
If 'sudo make INSTALL_HDR_PATH=/usr/include headers_install' were run,
some build artifacts in the kernel tree would be owned by root because
some of uapi headers are generated by 'uapi-asm-generic', 'archheaders'
targets.
Anyway, I believe it makes sense to split the header installation into
two stages.
[1] 'make headers'
Process headers in uapi directories by scripts/headers_install.sh
and copy them to usr/include
[2] 'make headers_install'
Copy '*.h' verbatim from usr/include to $(INSTALL_HDR_PATH)/include
For the backward compatibility, 'headers_install' depends on 'headers'.
Some samples expect uapi headers in usr/include. So, the 'headers'
target is useful to build up them in the fixed location usr/include
irrespective of INSTALL_HDR_PATH.
Another benefit is to stop polluting the final destination with the
time-stamp files '.install' and '.check'. Maybe you can see them in
your toolchains.
Lastly, my main motivation is to prepare for compile-testing uapi
headers. To build something, we have to save an object and .*.cmd
somewhere. The usr/include/ will be the work directory for that.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Currently, scripts/unifdef is compiled after scripts_basic,
uapi-asm-generic, archheaders, and archscripts.
The proper dependency is just scripts_basic. There is no problem
to compile scripts/unifdef and other headers at the same time.
Split scripts_unifdef out in order to allow more parallel building.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Since commit 2aedcd098a ("kbuild: suppress annoying "... is up to date."
message"), if_changed and friends nicely suppress "is up to date" messages.
We do not need per-Makefile tricks.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Commit 5318321d36 ("samples: disable CONFIG_SAMPLES for UML") used
a big hammer to fix the build errors under the samples/ directory.
Only some samples actually include uapi headers from usr/include.
Introduce CONFIG_HEADERS_INSTALL since 'depends on HEADERS_INSTALL' is
clearer than 'depends on !UML'. If this option is enabled, uapi headers
are installed before starting directory descending.
I added 'depends on HEADERS_INSTALL' to per-sample CONFIG options.
This allows UML to compile some samples.
$ make ARCH=um allmodconfig samples/
[ snip ]
CC [M] samples/configfs/configfs_sample.o
CC [M] samples/kfifo/bytestream-example.o
CC [M] samples/kfifo/dma-example.o
CC [M] samples/kfifo/inttype-example.o
CC [M] samples/kfifo/record-example.o
CC [M] samples/kobject/kobject-example.o
CC [M] samples/kobject/kset-example.o
CC [M] samples/trace_events/trace-events-sample.o
CC [M] samples/trace_printk/trace-printk.o
AR samples/vfio-mdev/built-in.a
AR samples/built-in.a
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
'gdb_script' needs headers generated by ./Kbuild, which is visited
by 'prepare0'. None of 'gdb_script' depends on 'prepare'.
Loosen the dependency.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Commit 8e2faea877 ("Make Documenation depend on headers_install")
dates back to 2014, which is before Sphinx was introduced for the
kernel documentation.
Since none of DOC_TARGET requires headers_install, it is strange to
run it only for the single target "Documentation/".
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
headers_install_all does not make much sense any more because different
architectures export different set of uapi/linux/ headers. As you see
in include/uapi/linux/Kbuild, the installation of a.out.h, kvm.h, and
kvm_para.h is arch-dependent. So, headers_install_all repeats the
installation/removal of them.
If somebody really thinks it is useful to do headers_install for all
architectures, it would be possible by small shell-scripting, but
the top Makefile does not have to provide entry targets just for that
purpose.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Current implementation of kselftest-merge only finds config files that
are one level deep using `$(srctree)/tools/testing/selftests/*/config`.
Often, config files are added in nested directories, and do not get
picked up by kselftest-merge.
Use `find` to catch all config files under
`$(srctree)/tools/testing/selftests` instead.
Signed-off-by: Dan Rue <dan.rue@linaro.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
In the recent build test of linux-next, Stephen saw a build error
caused by a broken .tmp_versions/*.mod file:
https://lkml.org/lkml/2019/5/13/991
drivers/net/phy/asix.ko and drivers/net/usb/asix.ko have the same
basename, and there is a race in generating .tmp_versions/asix.mod
Kbuild has not checked this before, and it suddenly shows up with
obscure error messages when this kind of race occurs.
Non-unique module names cause various sort of problems, but it is
not trivial to catch them by eyes.
Hence, this script.
It checks not only real modules, but also built-in modules (i.e.
controlled by tristate CONFIG option, but currently compiled with =y).
Non-unique names for built-in modules also cause problems because
/sys/modules/ would fall over.
For the latest kernel, I tested "make allmodconfig all" (or more
quickly "make allyesconfig modules"), and it detected the following:
warning: same basename if the following are built as modules:
drivers/regulator/88pm800.ko
drivers/mfd/88pm800.ko
warning: same basename if the following are built as modules:
drivers/gpu/drm/bridge/adv7511/adv7511.ko
drivers/media/i2c/adv7511.ko
warning: same basename if the following are built as modules:
drivers/net/phy/asix.ko
drivers/net/usb/asix.ko
warning: same basename if the following are built as modules:
fs/coda/coda.ko
drivers/media/platform/coda/coda.ko
warning: same basename if the following are built as modules:
drivers/net/phy/realtek.ko
drivers/net/dsa/realtek.ko
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
If the compiler specified by $(CC) is not present, the Kconfig stage
sprinkles 'not found' messages, then succeeds.
$ make CROSS_COMPILE=foo defconfig
/bin/sh: 1: foogcc: not found
/bin/sh: 1: foogcc: not found
*** Default configuration is based on 'x86_64_defconfig'
./scripts/gcc-version.sh: 17: ./scripts/gcc-version.sh: foogcc: not found
./scripts/gcc-version.sh: 18: ./scripts/gcc-version.sh: foogcc: not found
./scripts/gcc-version.sh: 19: ./scripts/gcc-version.sh: foogcc: not found
./scripts/gcc-version.sh: 17: ./scripts/gcc-version.sh: foogcc: not found
./scripts/gcc-version.sh: 18: ./scripts/gcc-version.sh: foogcc: not found
./scripts/gcc-version.sh: 19: ./scripts/gcc-version.sh: foogcc: not found
./scripts/clang-version.sh: 11: ./scripts/clang-version.sh: foogcc: not found
./scripts/gcc-plugin.sh: 11: ./scripts/gcc-plugin.sh: foogcc: not found
init/Kconfig:16:warning: 'GCC_VERSION': number is invalid
#
# configuration written to .config
#
Terminate parsing files immediately if $(CC) or $(LD) is not found.
"make *config" will fail more nicely.
$ make CROSS_COMPILE=foo defconfig
*** Default configuration is based on 'x86_64_defconfig'
scripts/Kconfig.include:34: compiler 'foogcc' not found
make[1]: *** [scripts/kconfig/Makefile;82: defconfig] Error 1
make: *** [Makefile;557: defconfig] Error 2
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
syncconfig is responsible for keeping auto.conf up-to-date, so if it
fails for any reason, the build must be terminated immediately.
However, since commit 9390dff66a ("kbuild: invoke syncconfig if
include/config/auto.conf.cmd is missing"), Kbuild continues running
even after syncconfig fails.
You can confirm this by intentionally making syncconfig error out:
diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index 08ba146..307b9de 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -1023,6 +1023,9 @@ int conf_write_autoconf(int overwrite)
FILE *out, *tristate, *out_h;
int i;
+ if (overwrite)
+ return 1;
+
if (!overwrite && is_present(autoconf_name))
return 0;
Then, syncconfig fails, but Make would not stop:
$ make -s mrproper allyesconfig defconfig
$ make
scripts/kconfig/conf --syncconfig Kconfig
*** Error during sync of the configuration.
make[2]: *** [scripts/kconfig/Makefile;69: syncconfig] Error 1
make[1]: *** [Makefile;557: syncconfig] Error 2
make: *** [include/config/auto.conf.cmd] Deleting file 'include/config/tristate.conf'
make: Failed to remake makefile 'include/config/auto.conf'.
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
[ continue running ... ]
The reason is in the behavior of a pattern rule with multi-targets.
%/auto.conf %/auto.conf.cmd %/tristate.conf: $(KCONFIG_CONFIG)
$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
GNU Make knows this rule is responsible for making all the three files
simultaneously. As far as examined, auto.conf.cmd is the target in
question when this rule is invoked. It is probably because auto.conf.cmd
is included below the inclusion of auto.conf.
The inclusion of auto.conf is mandatory, while that of auto.conf.cmd
is optional. GNU Make does not care about the failure in the process
of updating optional include files.
I filed this issue (https://savannah.gnu.org/bugs/?56301) in case this
behavior could be improved somehow in future releases of GNU Make.
Anyway, it is quite easy to fix our Makefile.
Given that auto.conf is already a mandatory include file, there is no
reason to stick auto.conf.cmd optional. Make it mandatory as well.
Cc: linux-stable <stable@vger.kernel.org> # 5.0+
Fixes: 9390dff66a ("kbuild: invoke syncconfig if include/config/auto.conf.cmd is missing")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
We do not support old Clang versions. Upgrade your clang version
if any of these flags is unsupported.
Let's add all flags inside ifdef CONFIG_CC_IS_CLANG unconditionally.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
This is no longer a valid option in clang, it was removed in 3.5, which
we don't support.
cb3f812b6b
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This flag is documented in the GCC 4.6 manual, and recognized by
Clang as well. Let's rip off the cc-option switch.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
This warning was disabled by commit bd664f6b3e ("disable new
gcc-7.1.1 warnings for now") just because it was too noisy.
Thanks to Arnd Bergmann, all warnings have been fixed. Now, we are
ready to re-enable it.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
- allow users to invoke 'make' out of the source tree
- refactor scripts/mkmakefile
- deprecate KBUILD_SRC, which was used to track the source tree
location for O= build.
- fix recordmcount.pl in case objdump output is localized
- turn unresolved symbols in external modules to errors from warnings
by default; pass KBUILD_MODPOST_WARN=1 to get them back to warnings
- generate modules.builtin.modinfo to collect .modinfo data from
built-in modules
- misc Makefile cleanups
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Merge tag 'kbuild-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- allow users to invoke 'make' out of the source tree
- refactor scripts/mkmakefile
- deprecate KBUILD_SRC, which was used to track the source tree
location for O= build.
- fix recordmcount.pl in case objdump output is localized
- turn unresolved symbols in external modules to errors from warnings
by default; pass KBUILD_MODPOST_WARN=1 to get them back to warnings
- generate modules.builtin.modinfo to collect .modinfo data from
built-in modules
- misc Makefile cleanups
* tag 'kbuild-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (21 commits)
.gitignore: add more all*.config patterns
moduleparam: Save information about built-in modules in separate file
Remove MODULE_ALIAS() calls that take undefined macro
.gitignore: add leading and trailing slashes to generated directories
scripts/tags.sh: fix direct execution of scripts/tags.sh
scripts: override locale from environment when running recordmcount.pl
samples: kobject: allow CONFIG_SAMPLE_KOBJECT to become y
samples: seccomp: turn CONFIG_SAMPLE_SECCOMP into a bool option
kbuild: move Documentation to vmlinux-alldirs
kbuild: move samples/ to KBUILD_VMLINUX_OBJS
modpost: make KBUILD_MODPOST_WARN also configurable for external modules
kbuild: check arch/$(SRCARCH)/include/generated before out-of-tree build
kbuild: remove unneeded dependency for include/config/kernel.release
memory: squash drivers/memory/Makefile.asm-offsets
kbuild: use $(srctree) instead of KBUILD_SRC to check out-of-tree build
kbuild: mkmakefile: generate a simple wrapper of top Makefile
kbuild: mkmakefile: do not check the generated Makefile marker
kbuild: allow Kbuild to start from any directory
kbuild: pass $(MAKECMDGOALS) to sub-make as is
kbuild: fix warning "overriding recipe for target 'Makefile'"
...
Pull networking updates from David Miller:
"Highlights:
1) Support AES128-CCM ciphers in kTLS, from Vakul Garg.
2) Add fib_sync_mem to control the amount of dirty memory we allow to
queue up between synchronize RCU calls, from David Ahern.
3) Make flow classifier more lockless, from Vlad Buslov.
4) Add PHY downshift support to aquantia driver, from Heiner
Kallweit.
5) Add SKB cache for TCP rx and tx, from Eric Dumazet. This reduces
contention on SLAB spinlocks in heavy RPC workloads.
6) Partial GSO offload support in XFRM, from Boris Pismenny.
7) Add fast link down support to ethtool, from Heiner Kallweit.
8) Use siphash for IP ID generator, from Eric Dumazet.
9) Pull nexthops even further out from ipv4/ipv6 routes and FIB
entries, from David Ahern.
10) Move skb->xmit_more into a per-cpu variable, from Florian
Westphal.
11) Improve eBPF verifier speed and increase maximum program size,
from Alexei Starovoitov.
12) Eliminate per-bucket spinlocks in rhashtable, and instead use bit
spinlocks. From Neil Brown.
13) Allow tunneling with GUE encap in ipvs, from Jacky Hu.
14) Improve link partner cap detection in generic PHY code, from
Heiner Kallweit.
15) Add layer 2 encap support to bpf_skb_adjust_room(), from Alan
Maguire.
16) Remove SKB list implementation assumptions in SCTP, your's truly.
17) Various cleanups, optimizations, and simplifications in r8169
driver. From Heiner Kallweit.
18) Add memory accounting on TX and RX path of SCTP, from Xin Long.
19) Switch PHY drivers over to use dynamic featue detection, from
Heiner Kallweit.
20) Support flow steering without masking in dpaa2-eth, from Ioana
Ciocoi.
21) Implement ndo_get_devlink_port in netdevsim driver, from Jiri
Pirko.
22) Increase the strict parsing of current and future netlink
attributes, also export such policies to userspace. From Johannes
Berg.
23) Allow DSA tag drivers to be modular, from Andrew Lunn.
24) Remove legacy DSA probing support, also from Andrew Lunn.
25) Allow ll_temac driver to be used on non-x86 platforms, from Esben
Haabendal.
26) Add a generic tracepoint for TX queue timeouts to ease debugging,
from Cong Wang.
27) More indirect call optimizations, from Paolo Abeni"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1763 commits)
cxgb4: Fix error path in cxgb4_init_module
net: phy: improve pause mode reporting in phy_print_status
dt-bindings: net: Fix a typo in the phy-mode list for ethernet bindings
net: macb: Change interrupt and napi enable order in open
net: ll_temac: Improve error message on error IRQ
net/sched: remove block pointer from common offload structure
net: ethernet: support of_get_mac_address new ERR_PTR error
net: usb: smsc: fix warning reported by kbuild test robot
staging: octeon-ethernet: Fix of_get_mac_address ERR_PTR check
net: dsa: support of_get_mac_address new ERR_PTR error
net: dsa: sja1105: Fix status initialization in sja1105_get_ethtool_stats
vrf: sit mtu should not be updated when vrf netdev is the link
net: dsa: Fix error cleanup path in dsa_init_module
l2tp: Fix possible NULL pointer dereference
taprio: add null check on sched_nest to avoid potential null pointer dereference
net: mvpp2: cls: fix less than zero check on a u32 variable
net_sched: sch_fq: handle non connected flows
net_sched: sch_fq: do not assume EDT packets are ordered
net: hns3: use devm_kcalloc when allocating desc_cb
net: hns3: some cleanup for struct hns3_enet_ring
...
- Consolidate memory initialization Kconfigs (Kees)
- Implement support for Clang's stack variable auto-init (Alexander)
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Merge tag 'meminit-v5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull compiler-based variable initialization updates from Kees Cook:
"This is effectively part of my gcc-plugins tree, but as this adds some
Clang support, it felt weird to still call it "gcc-plugins". :)
This consolidates Kconfig for the existing stack variable
initialization (via structleak and stackleak gcc plugins) and adds
Alexander Potapenko's support for Clang's new similar functionality.
Summary:
- Consolidate memory initialization Kconfigs (Kees)
- Implement support for Clang's stack variable auto-init (Alexander)"
* tag 'meminit-v5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
security: Implement Clang's stack initialization
security: Move stackleak config to Kconfig.hardening
security: Create "kernel hardening" config area
Pull livepatching updates from Jiri Kosina:
- livepatching kselftests improvements from Joe Lawrence and Miroslav
Benes
- making use of gcc's -flive-patching option when available, from
Miroslav Benes
- kobject handling cleanups, from Petr Mladek
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching:
livepatch: Remove duplicated code for early initialization
livepatch: Remove custom kobject state handling
livepatch: Convert error about unsupported reliable stacktrace into a warning
selftests/livepatch: Add functions.sh to TEST_PROGS_EXTENDED
kbuild: use -flive-patching when CONFIG_LIVEPATCH is enabled
selftests/livepatch: use TEST_PROGS for test scripts
Problem:
When a kernel module is compiled as a separate module, some important
information about the kernel module is available via .modinfo section of
the module. In contrast, when the kernel module is compiled into the
kernel, that information is not available.
Information about built-in modules is necessary in the following cases:
1. When it is necessary to find out what additional parameters can be
passed to the kernel at boot time.
2. When you need to know which module names and their aliases are in
the kernel. This is very useful for creating an initrd image.
Proposal:
The proposed patch does not remove .modinfo section with module
information from the vmlinux at the build time and saves it into a
separate file after kernel linking. So, the kernel does not increase in
size and no additional information remains in it. Information is stored
in the same format as in the separate modules (null-terminated string
array). Because the .modinfo section is already exported with a separate
modules, we are not creating a new API.
It can be easily read in the userspace:
$ tr '\0' '\n' < modules.builtin.modinfo
ext4.softdep=pre: crc32c
ext4.license=GPL
ext4.description=Fourth Extended Filesystem
ext4.author=Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others
ext4.alias=fs-ext4
ext4.alias=ext3
ext4.alias=fs-ext3
ext4.alias=ext2
ext4.alias=fs-ext2
md_mod.alias=block-major-9-*
md_mod.alias=md
md_mod.description=MD RAID framework
md_mod.license=GPL
md_mod.parmtype=create_on_open:bool
md_mod.parmtype=start_dirty_degraded:int
...
Co-Developed-by: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
Signed-off-by: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com>
Acked-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Handle samples/ like the other top-level directories to simplify
the Makefile.
Include include/config/auto.conf earlier to evaluate
drivers-$(CONFIG_SAMPLES).
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
We already did this for clang, but now gcc has that warning too. Yes,
yes, the address may be unaligned. And that's kind of the point.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_INIT_STACK_ALL turns on stack initialization based on
-ftrivial-auto-var-init in Clang builds, which has greater coverage
than CONFIG_GCC_PLUGINS_STRUCTLEAK_BYREF_ALL.
-ftrivial-auto-var-init Clang option provides trivial initializers for
uninitialized local variables, variable fields and padding.
It has three possible values:
pattern - uninitialized locals are filled with a fixed pattern
(mostly 0xAA on 64-bit platforms, see https://reviews.llvm.org/D54604
for more details, but 0x000000AA for 32-bit pointers) likely to cause
crashes when uninitialized value is used;
zero (it's still debated whether this flag makes it to the official
Clang release) - uninitialized locals are filled with zeroes;
uninitialized (default) - uninitialized locals are left intact.
This patch uses only the "pattern" mode when CONFIG_INIT_STACK_ALL is
enabled.
Developers have the possibility to opt-out of this feature on a
per-variable basis by using __attribute__((uninitialized)), but such
use should be well justified in comments.
Co-developed-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Alexander Potapenko <glider@google.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Daniel Borkmann says:
====================
pull-request: bpf-next 2019-04-12
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Improve BPF verifier scalability for large programs through two
optimizations: i) remove verifier states that are not useful in pruning,
ii) stop walking parentage chain once first LIVE_READ is seen. Combined
gives approx 20x speedup. Increase limits for accepting large programs
under root, and add various stress tests, from Alexei.
2) Implement global data support in BPF. This enables static global variables
for .data, .rodata and .bss sections to be properly handled which allows
for more natural program development. This also opens up the possibility
to optimize program workflow by compiling ELFs only once and later only
rewriting section data before reload, from Daniel and with test cases and
libbpf refactoring from Joe.
3) Add config option to generate BTF type info for vmlinux as part of the
kernel build process. DWARF debug info is converted via pahole to BTF.
Latter relies on libbpf and makes use of BTF deduplication algorithm which
results in 100x savings compared to DWARF data. Resulting .BTF section is
typically about 2MB in size, from Andrii.
4) Add BPF verifier support for stack access with variable offset from
helpers and add various test cases along with it, from Andrey.
5) Extend bpf_skb_adjust_room() growth BPF helper to mark inner MAC header
so that L2 encapsulation can be used for tc tunnels, from Alan.
6) Add support for input __sk_buff context in BPF_PROG_TEST_RUN so that
users can define a subset of allowed __sk_buff fields that get fed into
the test program, from Stanislav.
7) Add bpf fs multi-dimensional array tests for BTF test suite and fix up
various UBSAN warnings in bpftool, from Yonghong.
8) Generate a pkg-config file for libbpf, from Luca.
9) Dump program's BTF id in bpftool, from Prashant.
10) libbpf fix to use smaller BPF log buffer size for AF_XDP's XDP
program, from Magnus.
11) kallsyms related fixes for the case when symbols are not present in
BPF selftests and samples, from Daniel
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
After cross-compiling the kernel, "make mrproper" should be executed
with the proper ARCH= option. Otherwise, stale objects will remain
under arch/$(SRCARCH)/.
One bad scenario is like this:
$ make ARCH=arm defconfig all # cross-compile the kernel for arm
$ make mrproper # mrproper for host-arch (i.e. x86)
$ make ARCH=arm O=build_dir defconfig all
If you miss ARCH= for mrproper and cross-compile the kernel with O=
and ARCH= options, Kbuild will happily start to build, but may fail
due to stale objects in the srctree.
If $(srctree)/arch/$(SRCARCH)/include/generated/ exists, let's stop
the out-of-tree build. To detect this, mrproper should clean only
arch/$(SRCARCH)/include/generated/.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This is unneeded since commit 43fee2b238 ("kbuild: do not redirect
the first prerequisite for filechk").
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
GCC 9 introduces a new option, -flive-patching. It disables certain
optimizations which could make a compilation unsafe for later live
patching of the running kernel.
The option is used only if CONFIG_LIVEPATCH is enabled and $(CC)
supports it.
Performance impact of the option was measured on three different
Intel machines - two bigger NUMA boxes and one smaller UMA box. Kernel
intensive (IO, scheduling, networking) benchmarks were selected, plus a
set of HPC workloads from NAS Parallel Benchmark. The tests were done on
upstream kernel 5.0-rc8 with openSUSE Leap 15.0 userspace.
The majority of the tests is unaffected. The only significant exception
is the scheduler section which suffers 1-3% degradation.
Evaluated-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
This patch adds new config option to trigger generation of BTF type
information from DWARF debuginfo for vmlinux and kernel modules through
pahole, which in turn relies on libbpf for btf_dedup() algorithm.
The intent is to record compact type information of all types used
inside kernel, including all the structs/unions/typedefs/etc. This
enables BPF's compile-once-run-everywhere ([0]) approach, in which
tracing programs that are inspecting kernel's internal data (e.g.,
struct task_struct) can be compiled on a system running some kernel
version, but would be possible to run on other kernel versions (and
configurations) without recompilation, even if the layout of structs
changed and/or some of the fields were added, removed, or renamed.
This is only possible if BPF loader can get kernel type info to adjust
all the offsets correctly. This patch is a first time in this direction,
making sure that BTF type info is part of Linux kernel image in
non-loadable ELF section.
BTF deduplication ([1]) algorithm typically provides 100x savings
compared to DWARF data, so resulting .BTF section is not big as is
typically about 2MB in size.
[0] http://vger.kernel.org/lpc-bpf2018.html#session-2
[1] https://facebookmicrosites.github.io/bpf/blog/2018/11/14/btf-enhancement.html
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
KBUILD_SRC was conventionally used for some different purposes:
[1] To remember the source tree path
[2] As a flag to check if sub-make is already done
[3] As a flag to check if Kbuild runs out of tree
For [1], we do not need to remember it because the top Makefile
can compute it by $(realpath $(dir $(lastword $(MAKEFILE_LIST))))
[2] has been replaced with self-commenting 'sub_make_done'.
For [3], we can distinguish in-tree/out-of-tree by comparing
$(srctree) and '.'
This commit converts [3] to prepare for the KBUILD_SRC removal.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Kbuild always runs in the top of the output directory.
If Make starts in the source directory with O=, it relocates the
working directory to the location specified by O=.
Also, users can start build from the output directory by using the
Makefile generated by scripts/mkmakefile.
With a little more effort, Kbuild will be able to start from any
directory path.
This commit allows to specify the source directory by using
the -f option.
For example, you can do:
$ cd path/to/output/dir
$ make -f path/to/source/dir/Makefile
Or, for the equivalent behavior, you can do:
$ make O=path/to/output/dir -f path/to/source/dir/Makefile
KBUILD_SRC is now deprecated.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kieran Bingham <kbingham@kernel.org>
Manipulating $(MAKECMDGOALS) for sub-make seems odd to me.
[1] 'make O=foo sub-make' is turned into 'make O=foo', which builds
the default targets. It would make sense to terminate the build with:
*** No rule to make target 'sub-make'. Stop.
[2] 'make O=foo defconfig _all' is turned into 'make O=foo defconfig',
which changes the behavior.
Let's pass $(MAKECMDGOALS) as is.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
If you do "make Makefile" with GNU Make 3.x, the following warning
is displayed:
$ make Makefile
Makefile:165: warning: overriding recipe for target 'Makefile'
Makefile:51: warning: ignoring old recipe for target 'Makefile'
make[1]: Nothing to be done for 'Makefile'.
make: Nothing to be done for 'Makefile'.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
When you run a "make *config" target, the retpoline compiler flags
are evaluated for nothing because the code is located above the
'ifeq ($(config-targets),1)'.
Move it a bit below to avoid unneeded computation in the Kconfig stage.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Pull core fixes from Thomas Gleixner:
"A small set of core updates:
- Make the watchdog respect the selected CPU mask again. That was
broken by the rework of the watchdog thread management and caused
inconsistent state and NMI watchdog being unstoppable.
- Ensure that the objtool build can find the libelf location.
- Remove dead kcore stub code"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
watchdog: Respect watchdog cpumask on CPU hotplug
objtool: Query pkg-config for libelf location
proc/kcore: Remove unused kclist_add_remap()
- Remove harmful -Oz option of Clang
- Get back the original behavior (no recursion for in-tree build)
for GNU Make 4.x
- Some minor fixes for coccinelle patches
- Do not overwrite .gitignore in the output directory in case
it is version-controlled
- Fix missed record-mcount bug for dynamic ftrace
- Fix endianness bug in modversions for relative CRC
- Cater to '^H' key code in Kconfig ncurses programs
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Merge tag 'kbuild-fixes-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- Remove harmful -Oz option of Clang
- Get back the original behavior (no recursion for in-tree build) for
GNU Make 4.x
- Some minor fixes for coccinelle patches
- Do not overwrite .gitignore in the output directory in case it is
version-controlled
- Fix missed record-mcount bug for dynamic ftrace
- Fix endianness bug in modversions for relative CRC
- Cater to '^H' key code in Kconfig ncurses programs
* tag 'kbuild-fixes-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kconfig/[mn]conf: handle backspace (^H) key
kbuild: modversions: Fix relative CRC byte order interpretation
scripts: coccinelle: Fix description of badty.cocci
kbuild: strip whitespace in cmd_record_mcount findstring
kbuild: do not overwrite .gitignore in output directory
kbuild: skip parsing pre sub-make code for recursion
coccinelle: put_device: reduce false positives
kbuild: skip sub-make for in-tree build with GNU Make 4.x
Revert "kbuild: use -Oz instead of -Os when using clang"
Commit 3a51ff3442 ("kbuild: gitignore output directory") seemed to
bother people who version-control output directories.
Andre Przywara says:
"Unfortunately this breaks my setup, because I keep a totally separate
git repository in my build directories to track (various versions of)
.config. So .gitignore there is carefully crafted to ignore most build
artefacts, but not .config, for instance."
Link: https://lkml.org/lkml/2019/3/22/1819
Reported-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
When Make recurses to the top Makefile with sub-make-done unset,
the code block surrounded by 'ifneq ($(sub-make-done),1) ... endif'
is parsed multiple times. This happens for in-tree building of
include/config/auto.conf, *-pkg, etc. with GNU Make 4.x.
This is a slight regression by commit 688931a5ad ("kbuild: skip
sub-make for in-tree build with GNU Make 4.x") in terms of performance
since that code block contains one $(shell ...) invocation.
Fix it by exporting the variable irrespective of sub-make being run.
I renamed it because GNU Make cannot properly export variables
containing hyphens. This is probably a bug of GNU Make, and the issue
in Kbuild had already been reported by commit 2bfbe7881e ("kbuild:
Do not use hyphen in exported variable name").
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Commit 2b50f7ab63 ("kbuild: add workaround for Debian make-kpkg")
annoyed people who want to wrap the top Makefile with GNUmakefile
to customize it for their use.
On second thought, we do not need to run the sub-make for in-tree
build with Make 4.x because the 'MAKEFLAGS += -rR' issue only happens
on GNU Make 3.x.
With this commit, people will get back their workflow, and the Debian
make-kpkg will still work.
Fixes: 2b50f7ab63 ("kbuild: add workaround for Debian make-kpkg")
Reported-by: Andreas Schwab <schwab@suse.de>
Reported-by: David Howells <dhowells@redhat.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Andreas Schwab <schwab@suse.de>
Tested-by: David Howells <dhowells@redhat.com>
The clang option -Oz enables *aggressive* optimization for size,
which doesn't necessarily result in smaller images, but can have
negative impact on performance. Switch back to the less aggressive
-Os.
This reverts commit 6748cb3c29.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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 <yamada.masahiro@socionext.com>
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 e8f5bdb02c ("[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 <dianders@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Since commit 3812b8c5c5 ("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 := 1
I 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 : Fixed
This 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: 3812b8c5c5 ("kbuild: make -r/-R effective in top Makefile for old Make versions")
Reported-by: Liz Zhang <lizzha@microsoft.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Lili Deng <v-lide@microsoft.com>
Cc: Manoj Srivastava <srivasta@debian.org>
- 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
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Merge tag 'kbuild-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
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
...
Here is the big driver core patchset for 5.1-rc1
More 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.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the big driver core patchset for 5.1-rc1
More 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_<level> logging functions
...
This build rule was introduced by commit cd05e6bdc6 ("[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 <yamada.masahiro@socionext.com>
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 <luc.vanoostenryck@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This code has been commented out since commit b7000adef1
("Don't set the INITRD_COMPRESS environment variable automatically").
Clean it up now.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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 <yamada.masahiro@socionext.com>
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 <yamada.masahiro@socionext.com>
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 <yamada.masahiro@socionext.com>
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.o
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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 <yamada.masahiro@socionext.com>
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 <yamada.masahiro@socionext.com>
Since -Wmaybe-uninitialized was introduced by GCC 4.7, we have patched
various false positives:
- commit e74fc973b6 ("Turn off -Wmaybe-uninitialized when building
with -Os") turned off this option for -Os.
- commit 815eb71e71 ("Kbuild: disable 'maybe-uninitialized' warning
for CONFIG_PROFILE_ALL_BRANCHES") turned off this option for
CONFIG_PROFILE_ALL_BRANCHES
- commit a76bcf557e ("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/2017/3/14/903
I 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 <yamada.masahiro@socionext.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
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 <kai@tp1.ruhr-uni-bochum.de>
| 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 <yamada.masahiro@socionext.com>
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 <yamada.masahiro@socionext.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
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 <yamada.masahiro@socionext.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Linus Torvalds
Matthias Maennich
Masahiro Yamada
Nathan Chancellor
Stephen Boyd
Joe Perches
Vasily Gorbik
Peter Collingbourne
Gustavo A. R. Silva
Seth Forshee
Geert Uytterhoeven
Jani Nikula
Dan Rue
Alexey Gladkov
David S. Miller
Kees Cook
Miroslav Benes
Andrii Nakryiko
Rolf Eike Beer
Matthias Kaehlcke
Douglas Anderson
Luc Van Oostenryck