Using macros in inline assembly allows us to work around bugs
in GCC's inlining decisions.
Compile macros.S and use it to assemble all C files.
Currently only x86 will use it.
Background:
The inlining pass of GCC doesn't include an assembler, so it's not aware
of basic properties of the generated code, such as its size in bytes,
or that there are such things as discontiuous blocks of code and data
due to the newfangled linker feature called 'sections' ...
Instead GCC uses a lazy and fragile heuristic: it does a linear count of
certain syntactic and whitespace elements in inlined assembly block source
code, such as a count of new-lines and semicolons (!), as a poor substitute
for "code size and complexity".
Unsurprisingly this heuristic falls over and breaks its neck whith certain
common types of kernel code that use inline assembly, such as the frequent
practice of putting useful information into alternative sections.
As a result of this fresh, 20+ years old GCC bug, GCC's inlining decisions
are effectively disabled for inlined functions that make use of such asm()
blocks, because GCC thinks those sections of code are "large" - when in
reality they are often result in just a very low number of machine
instructions.
This absolute lack of inlining provess when GCC comes across such asm()
blocks both increases generated kernel code size and causes performance
overhead, which is particularly noticeable on paravirt kernels, which make
frequent use of these inlining facilities in attempt to stay out of the
way when running on baremetal hardware.
Instead of fixing the compiler we use a workaround: we set an assembly macro
and call it from the inlined assembly block. As a result GCC considers the
inline assembly block as a single instruction. (Which it often isn't but I digress.)
This uglifies and bloats the source code - for example just the refcount
related changes have this impact:
Makefile | 9 +++++++--
arch/x86/Makefile | 7 +++++++
arch/x86/kernel/macros.S | 7 +++++++
scripts/Kbuild.include | 4 +++-
scripts/mod/Makefile | 2 ++
5 files changed, 26 insertions(+), 3 deletions(-)
Yay readability and maintainability, it's not like assembly code is hard to read
and maintain ...
We also hope that GCC will eventually get fixed, but we are not holding
our breath for that. Yet we are optimistic, it might still happen, any decade now.
[ mingo: Wrote new changelog describing the background. ]
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kbuild@vger.kernel.org
Link: http://lkml.kernel.org/r/20181003213100.189959-3-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This Kselftest fixes update for 4.9-rc5 consists of:
-- fixes to build failures
-- fixes to add missing config files to increase test coverage
-- fixes to cgroup test and a new cgroup test for memory.oom.group
-----BEGIN PGP SIGNATURE-----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=79Fh
-----END PGP SIGNATURE-----
Merge tag 'linux-kselftest-4.19-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pulled kselftest fixes from Shuah:
"This Kselftest fixes update for 4.9-rc5 consists of:
-- fixes to build failures
-- fixes to add missing config files to increase test coverage
-- fixes to cgroup test and a new cgroup test for memory.oom.group"
As a Kernel developer, I make heavy use of "make targz-pkg" in order
to locally compile and remotely install my development Kernels. The
nice feature I rely on is that after a normal "make", "make targz-pkg"
only generates the tarball without having to recompile everything.
That was true until commit f28bc3c32c ("tracing: Handle
CC_FLAGS_FTRACE more accurately"). After it, running "make targz-pkg"
after "make" will recompile the whole Kernel tree, making my
development workflow much slower.
The Kernel is choosing to recompile everything because it claims the
command line has changed. A diff of the .cmd files show a repeated
-mfentry in one of the files. That is because "make targz-pkg" calls
"make modules_install" and the environment is already populated with
the exported variables, CC_FLAGS_FTRACE being one of them. Then,
-mfentry gets duplicated because it is not protected behind an ifndef
block, like -pg.
To complicate the problem a little bit more, architectures can define
their own version CC_FLAGS_FTRACE, so our code not only has to
consider recursive Makefiles, but also architecture overrides.
So in this patch we move CC_FLAGS_FTRACE up and unconditionally
define it to -pg. Then we let the architecture Makefiles possibly
override it, and finally append the extra options later. This ensures
the variable is always fully redefined at each invocation so recursive
Makefiles don't keep appending, and hopefully it maintains the
intended behavior on how architectures can override the defaults..
Thanks Steven Rostedt and Vasily Gorbik for the help on this
regression.
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: linux-kbuild@vger.kernel.org
Fixes: commit f28bc3c32c ("tracing: Handle CC_FLAGS_FTRACE more accurately")
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If the kernel headers aren't installed we can't build all the tests.
Add a new make target rule 'khdr' in the file lib.mk to generate the
kernel headers and that gets include for every test-dir Makefile that
includes lib.mk If the testdir in turn have its own sub-dirs the
top_srcdir needs to be set to the linux-rootdir to be able to generate
the kernel headers.
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: Fathi Boudra <fathi.boudra@linaro.org>
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
Pull x86 fixes from Thomas Gleixner:
- Correct the L1TF fallout on 32bit and the off by one in the 'too much
RAM for protection' calculation.
- Add a helpful kernel message for the 'too much RAM' case
- Unbreak the VDSO in case that the compiler desides to use indirect
jumps/calls and emits retpolines which cannot be resolved because the
kernel uses its own thunks, which does not work for the VDSO. Make it
use the builtin thunks.
- Re-export start_thread() which was unexported when the 32/64bit
implementation was unified. start_thread() is required by modular
binfmt handlers.
- Trivial cleanups
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/speculation/l1tf: Suggest what to do on systems with too much RAM
x86/speculation/l1tf: Fix off-by-one error when warning that system has too much RAM
x86/kvm/vmx: Remove duplicate l1d flush definitions
x86/speculation/l1tf: Fix overflow in l1tf_pfn_limit() on 32bit
x86/process: Re-export start_thread()
x86/mce: Add notifier_block forward declaration
x86/vdso: Fix vDSO build if a retpoline is emitted
Commit a0f97e06a4 ("kbuild: enable 'make CFLAGS=...' to add
additional options to CC") renamed CFLAGS to KBUILD_CFLAGS.
Commit 222d394d30 ("kbuild: enable 'make AFLAGS=...' to add
additional options to AS") renamed AFLAGS to KBUILD_AFLAGS.
Commit 06c5040cdb ("kbuild: enable 'make CPPFLAGS=...' to add
additional options to CPP") renamed CPPFLAGS to KBUILD_CPPFLAGS.
For some reason, LDFLAGS was not renamed.
Using a well-known variable like LDFLAGS may result in accidental
override of the variable.
Kbuild generally uses KBUILD_ prefixed variables for the internally
appended options, so here is one more conversion to sanitize the
naming convention.
I did not touch Makefiles under tools/ since the tools build system
is a different world.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
This config option should be enabled only when both the compiler and
the linker support necessary flags. Add proper dependencies to Kconfig.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
As commit ebaad7d364 ("kbuild: rpm: prompt to use "rpm-pkg" if "rpm"
target is used") noticed, the "rpm" target is now removed.
I assume people have already migrated to "rpm-pkg".
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
- Restructure of lockdep and latency tracers
This is the biggest change. Joel Fernandes restructured the hooks
from irqs and preemption disabling and enabling. He got rid of
a lot of the preprocessor #ifdef mess that they caused.
He turned both lockdep and the latency tracers to use trace events
inserted in the preempt/irqs disabling paths. But unfortunately,
these started to cause issues in corner cases. Thus, parts of the
code was reverted back to where lockde and the latency tracers
just get called directly (without using the trace events).
But because the original change cleaned up the code very nicely
we kept that, as well as the trace events for preempt and irqs
disabling, but they are limited to not being called in NMIs.
- Have trace events use SRCU for "rcu idle" calls. This was required
for the preempt/irqs off trace events. But it also had to not
allow them to be called in NMI context. Waiting till Paul makes
an NMI safe SRCU API.
- New notrace SRCU API to allow trace events to use SRCU.
- Addition of mcount-nop option support
- SPDX headers replacing GPL templates.
- Various other fixes and clean ups.
- Some fixes are marked for stable, but were not fully tested
before the merge window opened.
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCW3ruhRQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6qiM7AP47NhYdSnCFCRUJfrt6PovXmQtuCHt3
c3QMoGGdvzh9YAEAqcSXwh7uLhpHUp1LjMAPkXdZVwNddf4zJQ1zyxQ+EAU=
=vgEr
-----END PGP SIGNATURE-----
Merge tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
- Restructure of lockdep and latency tracers
This is the biggest change. Joel Fernandes restructured the hooks
from irqs and preemption disabling and enabling. He got rid of a lot
of the preprocessor #ifdef mess that they caused.
He turned both lockdep and the latency tracers to use trace events
inserted in the preempt/irqs disabling paths. But unfortunately,
these started to cause issues in corner cases. Thus, parts of the
code was reverted back to where lockdep and the latency tracers just
get called directly (without using the trace events). But because the
original change cleaned up the code very nicely we kept that, as well
as the trace events for preempt and irqs disabling, but they are
limited to not being called in NMIs.
- Have trace events use SRCU for "rcu idle" calls. This was required
for the preempt/irqs off trace events. But it also had to not allow
them to be called in NMI context. Waiting till Paul makes an NMI safe
SRCU API.
- New notrace SRCU API to allow trace events to use SRCU.
- Addition of mcount-nop option support
- SPDX headers replacing GPL templates.
- Various other fixes and clean ups.
- Some fixes are marked for stable, but were not fully tested before
the merge window opened.
* tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits)
tracing: Fix SPDX format headers to use C++ style comments
tracing: Add SPDX License format tags to tracing files
tracing: Add SPDX License format to bpf_trace.c
blktrace: Add SPDX License format header
s390/ftrace: Add -mfentry and -mnop-mcount support
tracing: Add -mcount-nop option support
tracing: Avoid calling cc-option -mrecord-mcount for every Makefile
tracing: Handle CC_FLAGS_FTRACE more accurately
Uprobe: Additional argument arch_uprobe to uprobe_write_opcode()
Uprobes: Simplify uprobe_register() body
tracepoints: Free early tracepoints after RCU is initialized
uprobes: Use synchronize_rcu() not synchronize_sched()
tracing: Fix synchronizing to event changes with tracepoint_synchronize_unregister()
ftrace: Remove unused pointer ftrace_swapper_pid
tracing: More reverting of "tracing: Centralize preemptirq tracepoints and unify their usage"
tracing/irqsoff: Handle preempt_count for different configs
tracing: Partial revert of "tracing: Centralize preemptirq tracepoints and unify their usage"
tracing: irqsoff: Account for additional preempt_disable
trace: Use rcu_dereference_raw for hooks from trace-event subsystem
tracing/kprobes: Fix within_notrace_func() to check only notrace functions
...
Currently, if the vDSO ends up containing an indirect branch or
call, GCC will emit the "external thunk" style of retpoline, and it
will fail to link.
Fix it by building the vDSO with inline retpoline thunks.
I haven't seen any reports of this triggering on an unpatched
kernel.
Fixes: commit 76b043848f ("x86/retpoline: Add initial retpoline support")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Matt Rickard <matt@softrans.com.au>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jason Vas Dias <jason.vas.dias@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/c76538cd3afbe19c6246c2d1715bc6a60bd63985.1534448381.git.luto@kernel.org
-mcount-nop gcc option generates the calls to the profiling functions
as nops which allows to avoid patching mcount jump with NOP instructions
initially.
-mcount-nop gcc option will be activated if platform selects
HAVE_NOP_MCOUNT and gcc actually supports it.
In addition to that CC_USING_NOP_MCOUNT is defined and could be used by
architectures to adapt ftrace patching behavior.
Link: http://lkml.kernel.org/r/patch-3.thread-aa7b8d.git-e02ed2dc082b.your-ad-here.call-01533557518-ext-9465@work.hours
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Currently if CONFIG_FTRACE_MCOUNT_RECORD is enabled -mrecord-mcount
compiler flag support is tested for every Makefile.
Top 4 cc-option usages:
511 -mrecord-mcount
11 -fno-stack-protector
9 -Wno-override-init
2 -fsched-pressure
To address that move cc-option from scripts/Makefile.build to top Makefile
and export CC_USING_RECORD_MCOUNT to be used in original place.
While doing that also add -mrecord-mcount to CC_FLAGS_FTRACE (if gcc
actually supports it).
Link: http://lkml.kernel.org/r/patch-2.thread-aa7b8d.git-de935bace15a.your-ad-here.call-01533557518-ext-9465@work.hours
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
CC_FLAGS_FTRACE is exported and later used to remove ftrace relevant
build flags from files which should be built without ftrace support.
For that reason add -mfentry to CC_FLAGS_FTRACE as well. That fixes
a problem with vdso32 build on s390, where -mfentry could not be used
together with -m31 flag.
At the same time flags like -pg and -mfentry are not relevant for asm
files, so avoid adding them to KBUILD_AFLAGS.
Introduce CC_FLAGS_USING instead of CC_USING_FENTRY to collect
-DCC_USING_FENTRY (and future alike) which are relevant for both
KBUILD_CFLAGS and KBUILD_AFLAGS.
Link: http://lkml.kernel.org/r/patch-1.thread-aa7b8d.git-42971afe87de.your-ad-here.call-01533557518-ext-9465@work.hours
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
- show clearer error messages where pkg-config is needed, but not
installed
- rename SYMBOL_AUTO to SYMBOL_NO_WRITE to reflect its semantics
- create all necessary directories by Kconfig tool itself instead
of Makefile
- update the .config unconditionally when syncconfig is invoked
- use 'include' directive instead of '-include' where
include/config/{auto,tristate}.conf is mandatory
- do not try to update the .config when running install targets
- add .DELETE_ON_ERROR to delete partially updated files
- misc cleanups and fixes
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=/Dow
-----END PGP SIGNATURE-----
Merge tag 'kconfig-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kconfig updates from Masahiro Yamada:
- show clearer error messages where pkg-config is needed, but not
installed
- rename SYMBOL_AUTO to SYMBOL_NO_WRITE to reflect its semantics
- create all necessary directories by Kconfig tool itself instead of
Makefile
- update the .config unconditionally when syncconfig is invoked
- use 'include' directive instead of '-include' where
include/config/{auto,tristate}.conf is mandatory
- do not try to update the .config when running install targets
- add .DELETE_ON_ERROR to delete partially updated files
- misc cleanups and fixes
* tag 'kconfig-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kconfig: remove P_ENV property type
kconfig: remove unused sym_get_env_prop() function
kconfig: fix the rule of mainmenu_stmt symbol
init/Kconfig: Use short unix-style option instead of --longname
Kbuild: Makefile.modbuiltin: include auto.conf and tristate.conf mandatory
kbuild: remove auto.conf from prerequisite of phony targets
kbuild: do not update config for 'make kernelrelease'
kbuild: do not update config when running install targets
kbuild: add .DELETE_ON_ERROR special target
kbuild: use 'include' directive to load auto.conf from top Makefile
kconfig: allow all config targets to write auto.conf if missing
kconfig: make syncconfig update .config regardless of sym_change_count
kconfig: create directories needed for syncconfig by itself
kconfig: remove unneeded directory generation from local*config
kconfig: split out useful helpers in confdata.c
kconfig: rename file_write_dep and move it to confdata.c
kconfig: fix typos in description of "choice" in kconfig-language.txt
kconfig: handle format string before calling conf_message_callback()
kconfig: rename SYMBOL_AUTO to SYMBOL_NO_WRITE
kconfig: check for pkg-config on make {menu,n,g,x}config
- verify depmod is installed before modules_install
- support build salt in case build ids must be unique between builds
- allow users to specify additional host compiler flags via HOST*FLAGS,
and rename internal variables to KBUILD_HOST*FLAGS
- update buildtar script to drop vax support, add arm64 support
- update builddeb script for better debarch support
- document the pit-fall of if_changed usage
- fix parallel build of UML with O= option
- make 'samples' target depend on headers_install to fix build errors
- remove deprecated host-progs variable
- add a new coccinelle script for refcount_t vs atomic_t check
- improve double-test coccinelle script
- misc cleanups and fixes
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=VjfG
-----END PGP SIGNATURE-----
Merge tag 'kbuild-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- verify depmod is installed before modules_install
- support build salt in case build ids must be unique between builds
- allow users to specify additional host compiler flags via HOST*FLAGS,
and rename internal variables to KBUILD_HOST*FLAGS
- update buildtar script to drop vax support, add arm64 support
- update builddeb script for better debarch support
- document the pit-fall of if_changed usage
- fix parallel build of UML with O= option
- make 'samples' target depend on headers_install to fix build errors
- remove deprecated host-progs variable
- add a new coccinelle script for refcount_t vs atomic_t check
- improve double-test coccinelle script
- misc cleanups and fixes
* tag 'kbuild-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (41 commits)
coccicheck: return proper error code on fail
Coccinelle: doubletest: reduce side effect false positives
kbuild: remove deprecated host-progs variable
kbuild: make samples really depend on headers_install
um: clean up archheaders recipe
kbuild: add %asm-generic to no-dot-config-targets
um: fix parallel building with O= option
scripts: Add Python 3 support to tracing/draw_functrace.py
builddeb: Add automatic support for sh{3,4}{,eb} architectures
builddeb: Add automatic support for riscv* architectures
builddeb: Add automatic support for m68k architecture
builddeb: Add automatic support for or1k architecture
builddeb: Add automatic support for sparc64 architecture
builddeb: Add automatic support for mips{,64}r6{,el} architectures
builddeb: Add automatic support for mips64el architecture
builddeb: Add automatic support for ppc64 and powerpcspe architectures
builddeb: Introduce functions to simplify kconfig tests in set_debarch
builddeb: Drop check for 32-bit s390
builddeb: Change architecture detection fallback to use dpkg-architecture
builddeb: Skip architecture detection when KBUILD_DEBARCH is set
...
Kernel headers must be installed into $(objtree)/usr/include to avoid
the build failure of samples.
Commit ddea05fa14 ("kbuild: make samples depend on headers_install")
addressed this, but "samples/" is only used for the single target build.
"make samples/" properly installs kernel headers, but it does not work
for general building because a phony target "sample" (no trailing slash)
is used.
Reported-by: David Howells <dhowells@redhat.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: David Howells <dhowells@redhat.com>
asm-generic and uapi-asm-generic do not depend on the kernel
configuration. In fact, uapi-asm-generic is the prerequisite of
headers_{install,check}, hence it should not require the .config file.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Richard Weinberger <richard@nod.at>
Currently, filechk unconditionally opens the first prerequisite and
redirects it as the stdin of a filechk_* rule. Hence, every target
using $(call filechk,...) must list something as the first prerequisite
even if it is unneeded.
'< $<' is actually unneeded in most cases. Each rule can explicitly
adds it if necessary.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
The top-level Makefile adds include/config/auto.conf as
prerequisites of 'scripts', 'prepare1', etc.
They were needed to terminate the build when include/config/auto.conf
is missing.
Now that the inclusion of include/config/auto.conf is mandatory
in the top-level Makefile if dot-config is 1 (Note 'include' directive
is used instead of '-include').
Make terminates the build by itself if it fails to create or update
include/config/auto.conf so we are sure that include/config/auto.conf
exists in the very first stage of make.
I am still keeping include/config/auto.conf as the prerequisite of
%/modules.builtin because modules.builtin is a real file. According
to commit a6c366324c ("kbuild: Do not unnecessarily regenerate
modules.builtin"), it is intentional to compare time-stamps between
%/modules.builtin and include/config/auto.conf . I moved tristate.conf
here because it is only included from scripts/Makefile.modbuiltin.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
'make kernelrelease' depends on CONFIG_LOCALVERSION(_AUTO), but
for the same reason as install targets, we do not want to update
the configuration just for printing the kernelrelease string.
This is likely to happen when you compiled the kernel with
CROSS_COMPILE, but forget to pass it to 'make kernelrelease'.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
"make syncconfig" is automatically invoked when any of the following
happens:
- .config is updated
- any of Kconfig files is updated
- any of environment variables referenced in Kconfig is changed
Then, it updates configuration files such as include/config/auto.conf
include/generated/autoconf.h, etc.
Even install targets (install, modules_install, etc.) are no exception.
However, they should never ever modify the source tree. Install
targets are often run with root privileges. Once those configuration
files are owned by root, "make mrproper" would end up with permission
error.
Install targets should just copy things blindly. They should not care
whether the configuration is up-to-date or not. This makes more sense
because we are interested in the configuration that was used in the
previous kernel building.
This issue has existed since before, but rarely happened. I expect
more chance where people are hit by this; with the new Kconfig syntax
extension, the .config now contains the compiler information. If you
cross-compile the kernel with CROSS_COMPILE, but forget to pass it
for "make install", you meet "any of environment variables referenced
in Kconfig is changed" because $(CC) is referenced in Kconfig.
Another scenario is the compiler upgrade before the installation.
Install targets need the configuration. "make modules_install" refer
to CONFIG_MODULES etc. "make dtbs_install" also needs CONFIG_ARCH_*
to decide which dtb files to install. However, the auto-update of
the configuration files should be avoided. We already do this for
external modules.
Now, Make targets are categorized into 3 groups:
[1] Do not need the kernel configuration at all
help, coccicheck, headers_install etc.
[2] Need the latest kernel configuration
If new config options are added, Kconfig will show prompt to
ask user's selection.
Build targets such as vmlinux, in-kernel modules are the cases.
[3] Need the kernel configuration, but do not want to update it
Install targets except headers_install, and external modules
are the cases.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
When you build targets that require the kernel configuration, dot-config
is set to 1, then the top-level Makefile includes auto.conf. However,
Make considers its inclusion is optional because the '-include' directive
is used here.
If a necessary configuration file is missing for the external module
building, the following error message is displayed:
ERROR: Kernel configuration is invalid.
include/generated/autoconf.h or include/config/auto.conf are missing.
Run 'make oldconfig && make prepare' on kernel src to fix it.
However, Make still continues building; /bin/false let the creation of
'include/config/auto.config' fail, but Make can ignore the error since
it is included by the '-include' directive.
I guess the reason of using '-include' directive was to suppress
the warning when you build the kernel from a pristine source tree:
Makefile:605: include/config/auto.conf: No such file or directory
The previous commit made sure include/config/auto.conf exists after
the 'make *config' stage. Now, we can use the 'include' directive
without showing the warning.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Now that we have the rename in place, reuse the HOST*FLAGS options as
something that can be set from the command line and included with the
rest of the flags.
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
In preparation for enabling command line LDLIBS, re-name HOST_LOADLIBES
to KBUILD_HOSTLDLIBS as the internal use only flags. Also rename
existing usage to HOSTLDLIBS for consistency. This should not have any
visible effects.
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
In preparation for enabling command line LDFLAGS, re-name HOSTLDFLAGS
to KBUILD_HOSTLDFLAGS as the internal use only flags. This should not
have any visible effects.
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
In preparation for enabling command line CXXFLAGS, re-name HOSTCXXFLAGS
to KBUILD_HOSTCXXFLAGS as the internal use only flags. This should not
have any visible effects.
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
In preparation for enabling command line CFLAGS, re-name HOSTCFLAGS to
KBUILD_HOSTCFLAGS as the internal use only flags. This should not have
any visible effects.
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
- update Kbuild and Kconfig documents
- sanitize -I compiler option handling
- update extract-vmlinux script to recognize LZ4 and ZSTD
- fix tools Makefiles
- update tags.sh to handle __ro_after_init
- suppress warnings in case getconf does not recognize LFS_* parameters
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=aXcg
-----END PGP SIGNATURE-----
Merge tag 'kbuild-fixes-v4.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- update Kbuild and Kconfig documents
- sanitize -I compiler option handling
- update extract-vmlinux script to recognize LZ4 and ZSTD
- fix tools Makefiles
- update tags.sh to handle __ro_after_init
- suppress warnings in case getconf does not recognize LFS_* parameters
* tag 'kbuild-fixes-v4.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: suppress warnings from 'getconf LFS_*'
scripts/tags.sh: add __ro_after_init
tools: build: Use HOSTLDFLAGS with fixdep
tools: build: Fixup host c flags
tools build: fix # escaping in .cmd files for future Make
scripts: teach extract-vmlinux about LZ4 and ZSTD
kbuild: remove duplicated comments about PHONY
kbuild: .PHONY is not a variable, but PHONY is
kbuild: do not drop -I without parameter
kbuild: document the KBUILD_KCONFIG env. variable
kconfig: update user kconfig tools doc.
kbuild: delete INSTALL_FW_PATH from kbuild documentation
kbuild: update ARCH alias info for sparc
kbuild: update ARCH alias info for sh
Suppress warnings for systems that do not recognize LFS_*.
getconf: no such configuration parameter `LFS_CFLAGS'
getconf: no such configuration parameter `LFS_LDFLAGS'
getconf: no such configuration parameter `LFS_LIBS'
Fixes: d7f14c66c2 ("kbuild: Enable Large File Support for hostprogs")
Reported-by: Chen Feng <puck.chen@hisilicon.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Pull networking fixes from David Miller:
1) Verify netlink attributes properly in nf_queue, from Eric Dumazet.
2) Need to bump memory lock rlimit for test_sockmap bpf test, from
Yonghong Song.
3) Fix VLAN handling in lan78xx driver, from Dave Stevenson.
4) Fix uninitialized read in nf_log, from Jann Horn.
5) Fix raw command length parsing in mlx5, from Alex Vesker.
6) Cleanup loopback RDS connections upon netns deletion, from Sowmini
Varadhan.
7) Fix regressions in FIB rule matching during create, from Jason A.
Donenfeld and Roopa Prabhu.
8) Fix mpls ether type detection in nfp, from Pieter Jansen van Vuuren.
9) More bpfilter build fixes/adjustments from Masahiro Yamada.
10) Fix XDP_{TX,REDIRECT} flushing in various drivers, from Jesper
Dangaard Brouer.
11) fib_tests.sh file permissions were broken, from Shuah Khan.
12) Make sure BH/preemption is disabled in data path of mac80211, from
Denis Kenzior.
13) Don't ignore nla_parse_nested() return values in nl80211, from
Johannes berg.
14) Properly account sock objects ot kmemcg, from Shakeel Butt.
15) Adjustments to setting bpf program permissions to read-only, from
Daniel Borkmann.
16) TCP Fast Open key endianness was broken, it always took on the host
endiannness. Whoops. Explicitly make it little endian. From Yuching
Cheng.
17) Fix prefix route setting for link local addresses in ipv6, from
David Ahern.
18) Potential Spectre v1 in zatm driver, from Gustavo A. R. Silva.
19) Various bpf sockmap fixes, from John Fastabend.
20) Use after free for GRO with ESP, from Sabrina Dubroca.
21) Passing bogus flags to crypto_alloc_shash() in ipv6 SR code, from
Eric Biggers.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (87 commits)
qede: Adverstise software timestamp caps when PHC is not available.
qed: Fix use of incorrect size in memcpy call.
qed: Fix setting of incorrect eswitch mode.
qed: Limit msix vectors in kdump kernel to the minimum required count.
ipvlan: call dev_change_flags when ipvlan mode is reset
ipv6: sr: fix passing wrong flags to crypto_alloc_shash()
net: fix use-after-free in GRO with ESP
tcp: prevent bogus FRTO undos with non-SACK flows
bpf: sockhash, add release routine
bpf: sockhash fix omitted bucket lock in sock_close
bpf: sockmap, fix smap_list_map_remove when psock is in many maps
bpf: sockmap, fix crash when ipv6 sock is added
net: fib_rules: bring back rule_exists to match rule during add
hv_netvsc: split sub-channel setup into async and sync
net: use dev_change_tx_queue_len() for SIOCSIFTXQLEN
atm: zatm: Fix potential Spectre v1
s390/qeth: consistently re-enable device features
s390/qeth: don't clobber buffer on async TX completion
s390/qeth: avoid using is_multicast_ether_addr_64bits on (u8 *)[6]
s390/qeth: fix race when setting MAC address
...
With the brand-new syntax extension of Kconfig, we can directly
check the compiler capability in the configuration phase.
If the cc-can-link.sh fails, the BPFILTER_UMH is automatically
hidden by the dependency.
I also deleted 'default n', which is no-op.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The changes to automatically test for working stack protector compiler
support in the Kconfig files removed the special STACKPROTECTOR_AUTO
option that picked the strongest stack protector that the compiler
supported.
That was all a nice cleanup - it makes no sense to have the AUTO case
now that the Kconfig phase can just determine the compiler support
directly.
HOWEVER.
It also meant that doing "make oldconfig" would now _disable_ the strong
stackprotector if you had AUTO enabled, because in a legacy config file,
the sane stack protector configuration would look like
CONFIG_HAVE_CC_STACKPROTECTOR=y
# CONFIG_CC_STACKPROTECTOR_NONE is not set
# CONFIG_CC_STACKPROTECTOR_REGULAR is not set
# CONFIG_CC_STACKPROTECTOR_STRONG is not set
CONFIG_CC_STACKPROTECTOR_AUTO=y
and when you ran this through "make oldconfig" with the Kbuild changes,
it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had
been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just
CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version
used to be disabled (because it was really enabled by AUTO), and would
disable it in the new config, resulting in:
CONFIG_HAVE_CC_STACKPROTECTOR=y
CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
CONFIG_CC_STACKPROTECTOR=y
# CONFIG_CC_STACKPROTECTOR_STRONG is not set
CONFIG_CC_HAS_SANE_STACKPROTECTOR=y
That's dangerously subtle - people could suddenly find themselves with
the weaker stack protector setup without even realizing.
The solution here is to just rename not just the old RECULAR stack
protector option, but also the strong one. This does that by just
removing the CC_ prefix entirely for the user choices, because it really
is not about the compiler support (the compiler support now instead
automatially impacts _visibility_ of the options to users).
This results in "make oldconfig" actually asking the user for their
choice, so that we don't have any silent subtle security model changes.
The end result would generally look like this:
CONFIG_HAVE_CC_STACKPROTECTOR=y
CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
CONFIG_STACKPROTECTOR=y
CONFIG_STACKPROTECTOR_STRONG=y
CONFIG_CC_HAS_SANE_STACKPROTECTOR=y
where the "CC_" versions really are about internal compiler
infrastructure, not the user selections.
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As Documentation/kbuild/kconfig-language.txt notes, 'select' should be
be used with care - it forces a lower limit of another symbol, ignoring
the dependency. Currently, KCOV can select GCC_PLUGINS even if arch
does not select HAVE_GCC_PLUGINS. This could cause the unmet direct
dependency.
Now that Kconfig can test compiler capability, let's handle this in a
more sophisticated way.
There are two ways to enable KCOV; use the compiler that natively
supports -fsanitize-coverage=trace-pc, or build the SANCOV plugin if
the compiler has ability to build GCC plugins. Hence, the correct
dependency for KCOV is:
depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
You do not need to build the SANCOV plugin if the compiler already
supports -fsanitize-coverage=trace-pc. Hence, the select should be:
select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
With this, GCC_PLUGIN_SANCOV is selected only when necessary, so
scripts/Makefile.gcc-plugins can be cleaner.
I also cleaned up Kconfig and scripts/Makefile.kcov as well.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
