- Hand-off primary maintainership of Kbuild
- Fix build warnings
- Fix build error when GCOV is enabled with old compiler
- Fix HAVE_ASM_GOTO check when GCC plugin is enabled
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Merge tag 'kbuild-fixes-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- hand-off primary maintainership of Kbuild
- fix build warnings
- fix build error when GCOV is enabled with old compiler
- fix HAVE_ASM_GOTO check when GCC plugin is enabled
* tag 'kbuild-fixes-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
gconfig: remove misleading parentheses around a condition
jump label: fix passing kbuild_cflags when checking for asm goto support
Kbuild: use cc-disable-warning consistently for maybe-uninitialized
kbuild: external module build warnings when KBUILD_OUTPUT set and W=1
MAINTAINERS: add Masahiro Yamada as a Kbuild maintainer
Documentation/sparse.txt has been moved to
Documentation/dev-tools/sparse.rst
Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
If a structure is marked with __attribute__((designated_init)) from
GCC or Sparse, it needs to have all static initializers using designated
initialization. Fail the build for any missing cases. This attribute will
be used by the randstruct plugin to make sure randomized structures are
being correctly initialized.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
The latest change of asm goto support check added passing of KBUILD_CFLAGS
to compiler. When these flags reference gcc plugins that are not built yet,
the check fails.
When one runs "make bzImage" followed by "make modules", the kernel is always
built with HAVE_JUMP_LABEL disabled, while the modules are built depending on
CONFIG_JUMP_LABEL. If HAVE_JUMP_LABEL macro happens to be different, modules
are built with undefined references, e.g.:
ERROR: "static_key_slow_inc" [net/netfilter/xt_TEE.ko] undefined!
ERROR: "static_key_slow_dec" [net/netfilter/xt_TEE.ko] undefined!
ERROR: "static_key_slow_dec" [net/netfilter/nft_meta.ko] undefined!
ERROR: "static_key_slow_inc" [net/netfilter/nft_meta.ko] undefined!
ERROR: "nf_hooks_needed" [net/netfilter/ipvs/ip_vs.ko] undefined!
ERROR: "nf_hooks_needed" [net/ipv6/ipv6.ko] undefined!
ERROR: "static_key_count" [net/ipv6/ipv6.ko] undefined!
ERROR: "static_key_slow_inc" [net/ipv6/ipv6.ko] undefined!
This change moves the check before all these references are added
to KBUILD_CFLAGS. This is correct because subsequent KBUILD_CFLAGS
modifications are not relevant to this check.
Reported-by: Anton V. Boyarshinov <boyarsh@altlinux.org>
Fixes: 35f860f9ba ("jump label: pass kbuild_cflags when checking for asm goto support")
Cc: stable@vger.kernel.org # v4.10
Signed-off-by: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: David Lin <dtwlin@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
In commit a76bcf557e ("Kbuild: enable -Wmaybe-uninitialized warning
for "make W=1""), I reverted another change that happened to fix a problem
with old compilers, and now we get this report again with old compilers
(prior to gcc-4.8) and GCOV enabled:
cc1: warnings being treated as errors
drivers/gpu/drm/i915/intel_ringbuffer.c: In function 'intel_ring_setup_status_page':
drivers/gpu/drm/i915/intel_ringbuffer.c:438: error: 'mmio.reg' may be used uninitialized in this function
At top level:
>> cc1: error: unrecognized command line option "-Wno-maybe-uninitialized"
The problem is that we turn off the warning conditionally in a number
of places as we should, but one of them does it unconditionally.
Instead, change it to call cc-disable-warning as we do elsewhere.
The original patch that caused it was merged into linux-4.7, then
4.8 removed the change and 4.9 brought it back, so we probably want
a backport to 4.9 once this is merged.
Use a ':=' assignment instead of '=' to force the cc-disable-warning
call to only be evaluated once instead of every time.
Cc: stable@vger.kernel.org
Fixes: a76bcf557e ("Kbuild: enable -Wmaybe-uninitialized warning for "make W=1"")
Fixes: e72e2dfe7c ("gcov: disable -Wmaybe-uninitialized warning")
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
The patterns '.*.orig' and '.*.rej' are cleaned away by '*.orig' and
'*.rej' seen two lines above.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Extra gcc checks like W=1 were moved to scripts/Makefile.exrawarn,
so the file name in comment needs to be fixed.
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Pull objtool fixes from Ingo Molnar:
"A handful of objtool fixes related to unreachable code, plus a build
fix for out of tree modules"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool: Enclose contents of unreachable() macro in a block
objtool: Prevent GCC from merging annotate_unreachable()
objtool: Improve detection of BUG() and other dead ends
objtool: Fix CONFIG_STACK_VALIDATION=y warning for out-of-tree modules
Three more DocBook template files have been converted to RST; only 21 to
go. There are various build improvements and the usual array of
documentation improvements and fixes.
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Merge tag 'docs-4.11' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"A slightly quieter cycle for documentation this time around.
Three more DocBook template files have been converted to RST; only 21
to go. There are various build improvements and the usual array of
documentation improvements and fixes"
* tag 'docs-4.11' of git://git.lwn.net/linux: (44 commits)
docs / driver-api: Fix structure references in device_link.rst
PM / docs: Fix structure references in device.rst
Add a target to check broken external links in the Documentation
Documentation: Fix linux-api list typo
Documentation: DocBook/Makefile comment typo
Improve sparse documentation
Documentation: make Makefile.sphinx no-ops quieter
Documentation: DMA-ISA-LPC.txt
Documentation: input: fix path to input code definitions
docs: Remove the copyright year from conf.py
docs: Fix a warning in the Korean HOWTO.rst translation
PM / sleep / docs: Convert PM notifiers document to reST
PM / core / docs: Convert sleep states API document to reST
PM / core: Update kerneldoc comments in pm.h
doc-rst: Fix recursive make invocation from macros
doc-rst: Delete output of failed dot-SVG conversion
doc-rst: Break shell command sequences on failure
Documentation/sphinx: make targets independent of Sphinx work for HAVE_SPHINX=0
doc-rst: fixed cleandoc target when used with O=dir
Documentation/sphinx: prevent generation of .pyc files in the source tree
...
Pull perf updates from Ingo Molnar:
"On the kernel side the main changes in this cycle were:
- Add Intel Kaby Lake CPU support (Srinivas Pandruvada)
- AMD uncore driver updates for fam17 (Janakarajan Natarajan)
- Intel/PT updates and core events optimizations and cleanups
(Alexander Shishkin)
- cgroups events fixes (David Carrillo-Cisneros)
- kprobes improvements (Masami Hiramatsu)
- ... plus misc fixes and updates.
On the tooling side the main changes were:
- Support clang build in tools/{perf,lib/{bpf,traceevent,api}} with
CC=clang, to, for instance, take advantage of better warnings
(Arnaldo Carvalho de Melo):
- Introduce the 'delta-abs' 'perf diff' compute method, that orders
the histogram entries by the absolute value of the percentage delta
for a function in two perf.data files, i.e. the functions that
changed the most (increase or decrease in samples) comes first
(Namhyung Kim)
- Add support for parsing Intel uncore vendor event files and add
uncore vendor events for the Intel server processors (Haswell,
Broadwell, IvyBridge), Xeon Phi (Knights Landing) and Broadwell DE
(Andi Kleen)
- Introduce 'perf ftrace' a perf front end to the kernel's ftrace
function and function_graph tracer, defaulting to the
"function_graph" tracer, more work will be done in reviving this
effort, forward porting it from its initial patch submission
(Namhyung Kim)
- Add 'e' and 'c' hotkeys to expand/collapse call chains for a single
hist entry in the 'perf report' and 'perf top' TUI (Jiri Olsa)
- Account thread wait time (off CPU time) separately: sleep, iowait
and preempt, based on the prev_state of the last event, show the
breakdown when using "perf sched timehist --state" (Namhyumg Kim)
- Add more triggers to switch the output file (perf.data.TIMESTAMP).
Now, in addition to switching to a different output file when
receiving a SIGUSR2, one can also specify file size and time based
triggers:
perf record -a --switch-output=signal
is equivalent to what we had before:
perf record -a --switch-output
While we can also ask for the file to be "sliced" by size, taking
into account that that will happen only when we get woken up by the
kernel, i.e. one has to take into account the --mmap-pages (the
size of the perf mmap ring buffer):
perf record -a --switch-output=2G
will break the perf.data output into multiple files limited to 2GB
of samples, right when generating the output.
For time based samples, alert() will be used, so to have 1 minute
limited perf.data output files:
perf record -a --switch-output=1m
(Jiri Olsa)
- Improve 'perf trace' (Arnaldo Carvalho de Melo)
- 'perf kallsyms' toy tool to look for extended symbol information on
the running kernel and demonstrate the machine/thread/symbol APIs
for use in other tools, such as 'perf probe' (Arnaldo Carvalho de
Melo)
- ... plus tons of other changes, see the shortlog and Git log for
details"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (131 commits)
perf tools: Add missing parse_events_error() prototype
perf pmu: Fix check for unset alias->unit array
perf tools: Be consistent on the type of map->symbols[] interator
perf intel pt decoder: clang has no -Wno-override-init
perf evsel: Do not put a variable sized type not at the end of a struct
perf probe: Avoid accessing uninitialized 'map' variable
perf tools: Do not put a variable sized type not at the end of a struct
perf record: Do not put a variable sized type not at the end of a struct
perf tests: Synthesize struct instead of using field after variable sized type
perf bench numa: Make sure dprintf() is not defined
Revert "perf bench futex: Sanitize numeric parameters"
tools lib subcmd: Make it an error to pass a signed value to OPTION_UINTEGER
tools: Set the maximum optimization level according to the compiler being used
tools: Suppress request for warning options not existent in clang
samples/bpf: Reset global variables
samples/bpf: Ignore already processed ELF sections
samples/bpf: Add missing header
perf symbols: dso->name is an array, no need to check it against NULL
perf tests record: No need to test an array against NULL
perf symbols: No need to check if sym->name is NULL
...
When building a CONFIG_STACK_VALIDATION enabled kernel without the
libelf devel package installed, the Makefile prints a warning:
"Cannot use CONFIG_STACK_VALIDATION, please install libelf-dev, libelf-devel or elfutils-libelf-devel"
But when building an out-of-tree module, the warning doesn't show.
Instead it tries to use objtool, and the build fails with:
/bin/sh: ./tools/objtool/objtool: No such file or directory
Make sure the warning and the disabling of objtool occur in all cases,
by moving the CONFIG_STACK_VALIDATION checks outside the 'ifeq
($(KBUILD_EXTMOD),)' block in the Makefile.
Tested-By: Marc MERLIN <marc@merlins.org>
Suggested-by: Jessica Yu <jeyu@redhat.com>
Reported-by: Marc MERLIN <marc@merlins.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Jessica Yu <jeyu@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 3b27a0c85d ("objtool: Detect and warn if libelf is missing and don't break the build")
Link: http://lkml.kernel.org/r/b3088ae4a8698143d4851965793c61fec2135b1f.1487182864.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Documentation shouldn't have broken links.
sphinx linkcheck builder scans all documents for external links, tries
to open them with urllib2, and writes an overview which ones are broken
and redirected to standard output and to output.txt in the output
directory.
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Rémy Léone <remy.leone@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Some versions of ARM GCC compiler such as Android toolchain throws in a
'-fpic' flag by default. This causes the gcc-goto check script to fail
although some config would have '-fno-pic' flag in the KBUILD_CFLAGS.
This patch passes the KBUILD_CFLAGS to the check script so that the
script does not rely on the default config from different compilers.
Link: http://lkml.kernel.org/r/20170120234329.78868-1-dtwlin@google.com
Signed-off-by: David Lin <dtwlin@google.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Michal Marek <mmarek@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
New features:
. Allow configuring a 'perf ftrace' default --tracer (Taeung Song)
Infrastructure:
. Sync tools/arch/{powerpc,arm}/include/uapi/asm/kvm.h and
tools/arch/x86/include/asm/cpufeatures.h (Ingo Molnar)
. Add BPF program file system pinning APIs and respective
'perf test' entry (Joe Stringer)
. Make tools tree support 'make -s' (Josh Poimboeuf)
. Reference count maps in callchains, fixing SEGFAULT when
referencing maps after it is freed (Krister Johansen)
. Create for_each_event trace points iterator (Taeung Song)
. Do not consider an error not to have any perfconfig file
(Arnaldo Carvalho de Melo
. Propagate perf_config() errors (Arnaldo Carvalho de Melo)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-core-for-mingo-4.11-20170201' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
New features:
- Allow configuring a 'perf ftrace' default --tracer (Taeung Song)
Infrastructure changes:
- Sync tools/arch/{powerpc,arm}/include/uapi/asm/kvm.h and
tools/arch/x86/include/asm/cpufeatures.h (Ingo Molnar)
- Add BPF program file system pinning APIs and respective
'perf test' entry (Joe Stringer)
- Make tools tree support 'make -s' (Josh Poimboeuf)
- Reference count maps in callchains, fixing SEGFAULT when
referencing maps after it is freed (Krister Johansen)
- Create for_each_event trace points iterator (Taeung Song)
- Do not consider an error not to have any perfconfig file
(Arnaldo Carvalho de Melo
- Propagate perf_config() errors (Arnaldo Carvalho de Melo)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When doing a kernel build with 'make -s', everything is silenced except
the objtool build. That's because the tools tree support for silent
builds is some combination of missing and broken.
Three changes are needed to fix it:
- Makefile: propagate '-s' to the sub-make's MAKEFLAGS variable so the
tools Makefiles can see it.
- tools/scripts/Makefile.include: fix the tools Makefiles' ability to
recognize '-s'. The MAKE_VERSION and MAKEFLAGS checks are copied from
the top-level Makefile. This silences the "DESCEND objtool" message.
- tools/build/Makefile.build: add support to the tools Build files for
recognizing '-s'. Again the MAKE_VERSION and MAKEFLAGS checks are
copied from the top-level Makefile. This silences all the object
compile/link messages.
Reported-and-Tested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michal Marek <mmarek@suse.com>
Link: http://lkml.kernel.org/r/e8967562ef640c3ae9a76da4ae0f4e47df737c34.1484799200.git.jpoimboe@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When building a specific target such as bzImage, modules aren't normally
built. However if CONFIG_TRIM_UNUSED_KSYMS is enabled, no built modules
means none of the exported symbols are used and therefore they will all
be trimmed away from the final kernel. A subsequent "make modules" will
fail because modpost cannot find the needed symbols for those modules in
the kernel binary.
Let's make sure modules are also built whenever CONFIG_TRIM_UNUSED_KSYMS
is enabled and that the kernel binary is properly rebuilt accordingly.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some people are able to trigger a race where autoksyms.h is used before
its empty version is even created. Let's create it at the same time as
the directory holding it is created.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Prarit Bhargava <prarit@redhat.com>
Tested-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull kbuild fixes from Michal Marek:
"Here are some regression fixes for kbuild:
- modversion support for exported asm symbols (Nick Piggin). The
affected architectures need separate patches adding
asm-prototypes.h.
- fix rebuilds of lib-ksyms.o (Nick Piggin)
- -fno-PIE builds (Sebastian Siewior and Borislav Petkov). This is
not a kernel regression, but one of the Debian gcc package.
Nevertheless, it's quite annoying, so I think it should go into
mainline and stable now"
* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kbuild: Steal gcc's pie from the very beginning
kbuild: be more careful about matching preprocessed asm ___EXPORT_SYMBOL
x86/kexec: add -fno-PIE
scripts/has-stack-protector: add -fno-PIE
kbuild: add -fno-PIE
kbuild: modversions for EXPORT_SYMBOL() for asm
kbuild: prevent lib-ksyms.o rebuilds
So Sebastian turned off the PIE for kernel builds but that was too late
- Kbuild.include already uses KBUILD_CFLAGS and trying to disable gcc
options with, say cc-disable-warning, fails:
gcc -D__KERNEL__ -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs
...
-Wno-sign-compare -fno-asynchronous-unwind-tables -Wframe-address -c -x c /dev/null -o .31392.tmp
/dev/null:1:0: error: code model kernel does not support PIC mode
because that returns an error and we can't disable the warning. For
example in this case:
KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
which leads to gcc issuing all those warnings again.
So let's turn off PIE/PIC at the earliest possible moment, when we
declare KBUILD_CFLAGS so that cc-disable-warning picks it up too.
Also, we need the $(call cc-option ...) because -fno-PIE is supported
since gcc v3.4 and our lowest supported gcc version is 3.2 right now.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Michal Marek <mmarek@suse.com>
Traditionally, we have always had warnings about uninitialized variables
enabled, as this is part of -Wall, and generally a good idea [1], but it
also always produced false positives, mainly because this is a variation
of the halting problem and provably impossible to get right in all cases
[2].
Various people have identified cases that are particularly bad for false
positives, and in commit e74fc973b6 ("Turn off -Wmaybe-uninitialized
when building with -Os"), I turned off the warning for any build that
was done with CC_OPTIMIZE_FOR_SIZE. This drastically reduced the number
of false positive warnings in the default build but unfortunately had
the side effect of turning the warning off completely in 'allmodconfig'
builds, which in turn led to a lot of warnings (both actual bugs, and
remaining false positives) to go in unnoticed.
With commit 877417e6ff ("Kbuild: change CC_OPTIMIZE_FOR_SIZE
definition") enabled the warning again for allmodconfig builds in v4.7
and in v4.8-rc1, I had finally managed to address all warnings I get in
an ARM allmodconfig build and most other maybe-uninitialized warnings
for ARM randconfig builds.
However, commit 6e8d666e92 ("Disable "maybe-uninitialized" warning
globally") was merged at the same time and disabled it completely for
all configurations, because of false-positive warnings on x86 that I had
not addressed until then. This caused a lot of actual bugs to get
merged into mainline, and I sent several dozen patches for these during
the v4.9 development cycle. Most of these are actual bugs, some are for
correct code that is safe because it is only called under external
constraints that make it impossible to run into the case that gcc sees,
and in a few cases gcc is just stupid and finds something that can
obviously never happen.
I have now done a few thousand randconfig builds on x86 and collected
all patches that I needed to address every single warning I got (I can
provide the combined patch for the other warnings if anyone is
interested), so I hope we can get the warning back and let people catch
the actual bugs earlier.
This reverts the change to disable the warning completely and for now
brings it back at the "make W=1" level, so we can get it merged into
mainline without introducing false positives. A follow-up patch enables
it on all levels unless some configuration option turns it off because
of false-positives.
Link: https://rusty.ozlabs.org/?p=232 [1]
Link: https://gcc.gnu.org/wiki/Better_Uninitialized_Warnings [2]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Debian started to build the gcc with -fPIE by default so the kernel
build ends before it starts properly with:
|kernel/bounds.c:1:0: error: code model kernel does not support PIC mode
Also add to KBUILD_AFLAGS due to:
|gcc -Wp,-MD,arch/x86/entry/vdso/vdso32/.note.o.d … -mfentry -DCC_USING_FENTRY … vdso/vdso32/note.S
|arch/x86/entry/vdso/vdso32/note.S:1:0: sorry, unimplemented: -mfentry isn’t supported for 32-bit in combination with -fpic
Tagging it stable so it is possible to compile recent stable kernels as
well.
Cc: stable@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Michal Marek <mmarek@suse.com>
This update consists of:
- Fixes and improvements to existing tests
- Moving code from Documentation to selftests, samples, and tools.
Moves dnotify_test, prctl, ptp, vDSO, ia64, watchdog, and networking
tests from Documentation to selftests.
Moves mic/mpssd, misc-devices/mei, timers, watchdog, auxdisplay, and
blackfin examples from Documentation to samples.
Moves accounting, laptops/dslm, and pcmcia/crc32hash tools from
Documentation to tools.
Deletes BUILD_DOCSRC and its dependencies.
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Merge tag 'linux-kselftest-4.9-rc1-update' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull kselftest updates from Shuah Khan:
"This update consists of:
- Fixes and improvements to existing tests
- Moving code from Documentation to selftests, samples, and tools:
* Moves dnotify_test, prctl, ptp, vDSO, ia64, watchdog, and
networking tests from Documentation to selftests.
* Moves mic/mpssd, misc-devices/mei, timers, watchdog, auxdisplay,
and blackfin examples from Documentation to samples.
* Moves accounting, laptops/dslm, and pcmcia/crc32hash tools from
Documentation to tools.
* Deletes BUILD_DOCSRC and its dependencies"
* tag 'linux-kselftest-4.9-rc1-update' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (21 commits)
selftests/futex: Check ANSI terminal color support
Doc: update 00-INDEX files to reflect the runnable code move
samples: move blackfin gptimers-example from Documentation
tools: move pcmcia crc32hash tool from Documentation
tools: move laptops dslm tool from Documentation
tools: move accounting tool from Documentation
samples: move auxdisplay example code from Documentation
samples: move watchdog example code from Documentation
samples: move timers example code from Documentation
samples: move misc-devices/mei example code from Documentation
samples: move mic/mpssd example code from Documentation
selftests: Move networking/timestamping from Documentation
selftests: move watchdog tests from Documentation/watchdog
selftests: move ia64 tests from Documentation/ia64
selftests: move vDSO tests from Documentation/vDSO
selftests: move ptp tests from Documentation/ptp
selftests: move prctl tests from Documentation/prctl
selftests: move dnotify_test from Documentation/filesystems
selftests/timers: Add missing error code assignment before test
selftests/zram: replace ZRAM_LZ4_COMPRESS
...
Pull kbuild updates from Michal Marek:
- EXPORT_SYMBOL for asm source by Al Viro.
This does bring a regression, because genksyms no longer generates
checksums for these symbols (CONFIG_MODVERSIONS). Nick Piggin is
working on a patch to fix this.
Plus, we are talking about functions like strcpy(), which rarely
change prototypes.
- Fixes for PPC fallout of the above by Stephen Rothwell and Nick
Piggin
- fixdep speedup by Alexey Dobriyan.
- preparatory work by Nick Piggin to allow architectures to build with
-ffunction-sections, -fdata-sections and --gc-sections
- CONFIG_THIN_ARCHIVES support by Stephen Rothwell
- fix for filenames with colons in the initramfs source by me.
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (22 commits)
initramfs: Escape colons in depfile
ppc: there is no clear_pages to export
powerpc/64: whitelist unresolved modversions CRCs
kbuild: -ffunction-sections fix for archs with conflicting sections
kbuild: add arch specific post-link Makefile
kbuild: allow archs to select link dead code/data elimination
kbuild: allow architectures to use thin archives instead of ld -r
kbuild: Regenerate genksyms lexer
kbuild: genksyms fix for typeof handling
fixdep: faster CONFIG_ search
ia64: move exports to definitions
sparc32: debride memcpy.S a bit
[sparc] unify 32bit and 64bit string.h
sparc: move exports to definitions
ppc: move exports to definitions
arm: move exports to definitions
s390: move exports to definitions
m68k: move exports to definitions
alpha: move exports to actual definitions
x86: move exports to actual definitions
...
This affectively reverts commit 377ccbb483 ("Makefile: Mute warning
for __builtin_return_address(>0) for tracing only") because it turns out
that it really isn't tracing only - it's all over the tree.
We already also had the warning disabled separately for mm/usercopy.c
(which this commit also removes), and it turns out that we will also
want to disable it for get_lock_parent_ip(), that is used for at least
TRACE_IRQFLAGS. Which (when enabled) ends up being all over the tree.
Steven Rostedt had a patch that tried to limit it to just the config
options that actually triggered this, but quite frankly, the extra
complexity and abstraction just isn't worth it. We have never actually
had a case where the warning is actually useful, so let's just disable
it globally and not worry about it.
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move blackfin gptimers-example to samples and remove it from Documentation
Makefile. Update samples Kconfig and Makefile to build gptimers-example.
blackfin is the last CONFIG_BUILD_DOCSRC target in Documentation/Makefile.
Hence this patch also includes changes to remove CONFIG_BUILD_DOCSRC from
Makefile and lib/Kconfig.debug and updates VIDEO_PCI_SKELETON dependency
on BUILD_DOCSRC.
Documentation/Makefile is not deleted to avoid braking make htmldocs and
make distclean.
Acked-by: Michal Marek <mmarek@suse.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reported-by: Valentin Rothberg <valentinrothberg@gmail.com>
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
The Sphinx transition is still creating a fair amount of work. Here we
have a number of fixes and, importantly, a proper PDF output solution,
thanks to Jani Nikula, Mauro Carvalho Chehab and Markus Heiser.
I've started a couple of new books: a driver API book (based on the old
device-drivers.tmpl) and a development tools book. Both are meant to show
how we can integrate together our existing documentation into a more
coherent and accessible whole. It involves moving some stuff around and
formatting changes, but, I think, the results are worth it. The good news
is that most of our existing Documentation/*.txt files are *almost* in RST
format already; the amount of messing around required is minimal.
And, of course, there's the usual set of updates, typo fixes, and more.
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Merge tag 'docs-4.9' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"This is the documentation update pull for the 4.9 merge window.
The Sphinx transition is still creating a fair amount of work. Here we
have a number of fixes and, importantly, a proper PDF output solution,
thanks to Jani Nikula, Mauro Carvalho Chehab and Markus Heiser.
I've started a couple of new books: a driver API book (based on the
old device-drivers.tmpl) and a development tools book. Both are meant
to show how we can integrate together our existing documentation into
a more coherent and accessible whole. It involves moving some stuff
around and formatting changes, but, I think, the results are worth it.
The good news is that most of our existing Documentation/*.txt files
are *almost* in RST format already; the amount of messing around
required is minimal.
And, of course, there's the usual set of updates, typo fixes, and
more"
* tag 'docs-4.9' of git://git.lwn.net/linux: (120 commits)
URL changed for Linux Foundation TAB
dax : Fix documentation with respect to struct pages
iio: Documentation: Correct the path used to create triggers.
docs: Remove space-before-label guidance from CodingStyle
docs-rst: add inter-document cross references
Documentation/email-clients.txt: convert it to ReST markup
Documentation/kernel-docs.txt: reorder based on timestamp
Documentation/kernel-docs.txt: Add dates for online docs
Documentation/kernel-docs.txt: get rid of broken docs
Documentation/kernel-docs.txt: move in-kernel docs
Documentation/kernel-docs.txt: remove more legacy references
Documentation/kernel-docs.txt: add two published books
Documentation/kernel-docs.txt: sort books per publication date
Documentation/kernel-docs.txt: adjust LDD references
Documentation/kernel-docs.txt: some improvements on the ReST output
Documentation/kernel-docs.txt: Consistent indenting: 4 spaces
Documentation/kernel-docs.txt: Add 4 paper/book references
Documentation/kernel-docs.txt: Improve layouting of book list
Documentation/kernel-docs.txt: Remove offline or outdated entries
docs: Clean up bare :: lines
...
Allow architectures to create arch/xxx/Makefile.postlink with targets
for vmlinux, modules.ko, and clean, which will be invoked after final
linking of vmlinux and modules.
powerpc will use this to check vmlinux linker relocations for sanity,
and may use it to fix up alternate instruction patch branch addresses.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
Introduce LD_DEAD_CODE_DATA_ELIMINATION option for architectures to
select to build with -ffunction-sections, -fdata-sections, and link
with --gc-sections. It requires some work (documented) to ensure all
unreferenced entrypoints are live, and requires toolchain and build
verification, so it is made a per-arch option for now.
On a random powerpc64le build, this yelds a significant size saving,
it boots and runs fine, but there is a lot I haven't tested as yet, so
these savings may be reduced if there are bugs in the link.
text data bss dec filename
11169741 1180744 1923176 14273661 vmlinux
10445269 1004127 1919707 13369103 vmlinux.dce
~700K text, ~170K data, 6% removed from kernel image size.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
Sphinx supports LaTeX output. Sometimes, it is interesting to
call it directly, instead of also generating a PDF. As it comes
for free, add a target for it.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
When the compiler doesn't support gcc plugins (either due to missing
headers or too old a version), report the problem and abort the build
instead of emitting a warning and letting the build founder with arcane
compiler errors.
Signed-off-by: Kees Cook <keescook@chromium.org>
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Merge tag 'media/v4.8-5' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media DocBook removal and some fixups from Mauro Carvalho Chehab:
- removal of the media DocBook (since it's all in Sphinx now)
- videobuf2: Fix an allocation regression
- a few fixes related to the CEC drivers
* tag 'media/v4.8-5' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
[media] cec: fix off-by-one memset
[media] staging: add MEDIA_SUPPORT dependency
[media] vivid: don't handle CEC_MSG_SET_STREAM_PATH
[media] media: adv7180: Fix broken interrupt register access
[media] vb2: Fix allocation size of dma_parms
[media] vim2m: copy the other colorspace-related fields as well
[media] adv7511: fix VIC autodetect
doc-rst: Remove the media docbook
. Move the suppressing of the __builtin_return_address >0 warning to the
tracing directory only.
. metag recordmcount fix for newer glibc's
. Two tracing histogram fixes that were reported by KASAN
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Merge tag 'trace-v4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"A few updates and fixes:
- move the suppressing of the __builtin_return_address >0 warning to
the tracing directory only.
- metag recordmcount fix for newer glibc's
- two tracing histogram fixes that were reported by KASAN"
* tag 'trace-v4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix use-after-free in hist_register_trigger()
tracing: Fix use-after-free in hist_unreg_all/hist_enable_unreg_all
Makefile: Mute warning for __builtin_return_address(>0) for tracing only
ftrace/recordmcount: Work around for addition of metag magic but not relocations
Pull kbuild updates from Michal Marek:
- GCC plugin support by Emese Revfy from grsecurity, with a fixup from
Kees Cook. The plugins are meant to be used for static analysis of
the kernel code. Two plugins are provided already.
- reduction of the gcc commandline by Arnd Bergmann.
- IS_ENABLED / IS_REACHABLE macro enhancements by Masahiro Yamada
- bin2c fix by Michael Tautschnig
- setlocalversion fix by Wolfram Sang
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
gcc-plugins: disable under COMPILE_TEST
kbuild: Abort build on bad stack protector flag
scripts: Fix size mismatch of kexec_purgatory_size
kbuild: make samples depend on headers_install
Kbuild: don't add obj tree in additional includes
Kbuild: arch: look for generated headers in obtree
Kbuild: always prefix objtree in LINUXINCLUDE
Kbuild: avoid duplicate include path
Kbuild: don't add ../../ to include path
vmlinux.lds.h: replace config_enabled() with IS_ENABLED()
kconfig.h: allow to use IS_{ENABLE,REACHABLE} in macro expansion
kconfig.h: use already defined macros for IS_REACHABLE() define
export.h: use __is_defined() to check if __KSYM_* is defined
kconfig.h: use __is_defined() to check if MODULE is defined
kbuild: setlocalversion: print error to STDERR
Add sancov plugin
Add Cyclomatic complexity GCC plugin
GCC plugin infrastructure
Shared library support
With the latest gcc compilers, they give a warning if
__builtin_return_address() parameter is greater than 0. That is because if
it is used by a function called by a top level function (or in the case of
the kernel, by assembly), it can try to access stack frames outside the
stack and crash the system.
The tracing system uses __builtin_return_address() of up to 2! But it is
well aware of the dangers that it may have, and has even added precautions
to protect against it (see the thunk code in arch/x86/entry/thunk*.S)
Linus originally added KBUILD_CFLAGS that would suppress the warning for the
entire kernel, as simply adding KBUILD_CFLAGS to the tracing directory
wouldn't work. The tracing directory plays a bit with the CFLAGS and
requires a little more logic.
This adds that special logic to only suppress the warning for the tracing
directory. If it is used anywhere else outside of tracing, the warning will
still be triggered.
Link: http://lkml.kernel.org/r/20160728223043.51996267@grimm.local.home
Tested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Now that all media documentation was converted to Sphinx, we
should get rid of the old DocBook one, as we don't want people
to submit patches against the old stuff.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Newer versions of gcc warn about the use of __builtin_return_address()
with a non-zero argument when "-Wall" is specified:
kernel/trace/trace_irqsoff.c: In function ‘stop_critical_timings’:
kernel/trace/trace_irqsoff.c:433:86: warning: calling ‘__builtin_return_address’ with a nonzero argument is unsafe [-Wframe-address]
stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
[ .. repeats a few times for other similar cases .. ]
It is true that a non-zero argument is somewhat dangerous, and we do not
actually have very many uses of that in the kernel - but the ftrace code
does use it, and as Stephen Rostedt says:
"We are well aware of the danger of using __builtin_return_address() of
> 0. In fact that's part of the reason for having the "thunk" code in
x86 (See arch/x86/entry/thunk_{64,32}.S). [..] it adds extra frames
when tracking irqs off sections, to prevent __builtin_return_address()
from accessing bad areas. In fact the thunk_32.S states: 'Trampoline to
trace irqs off. (otherwise CALLER_ADDR1 might crash)'."
For now, __builtin_return_address() with a non-zero argument is the best
we can do, and the warning is not helpful and can end up making people
miss other warnings for real problems.
So disable the frame-address warning on compilers that need it.
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Several build configurations had already disabled this warning because
it generates a lot of false positives. But some had not, and it was
still enabled for "allmodconfig" builds, for example.
Looking at the warnings produced, every single one I looked at was a
false positive, and the warnings are frequent enough (and big enough)
that they can easily hide real problems that you don't notice in the
noise generated by -Wmaybe-uninitialized.
The warning is good in theory, but this is a classic case of a warning
that causes more problems than the warning can solve.
If gcc gets better at avoiding false positives, we may be able to
re-enable this warning. But as is, we're better off without it, and I
want to be able to see the *real* warnings.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge updates from Andrew Morton:
- a few misc bits
- ocfs2
- most(?) of MM
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (125 commits)
thp: fix comments of __pmd_trans_huge_lock()
cgroup: remove unnecessary 0 check from css_from_id()
cgroup: fix idr leak for the first cgroup root
mm: memcontrol: fix documentation for compound parameter
mm: memcontrol: remove BUG_ON in uncharge_list
mm: fix build warnings in <linux/compaction.h>
mm, thp: convert from optimistic swapin collapsing to conservative
mm, thp: fix comment inconsistency for swapin readahead functions
thp: update Documentation/{vm/transhuge,filesystems/proc}.txt
shmem: split huge pages beyond i_size under memory pressure
thp: introduce CONFIG_TRANSPARENT_HUGE_PAGECACHE
khugepaged: add support of collapse for tmpfs/shmem pages
shmem: make shmem_inode_info::lock irq-safe
khugepaged: move up_read(mmap_sem) out of khugepaged_alloc_page()
thp: extract khugepaged from mm/huge_memory.c
shmem, thp: respect MADV_{NO,}HUGEPAGE for file mappings
shmem: add huge pages support
shmem: get_unmapped_area align huge page
shmem: prepare huge= mount option and sysfs knob
mm, rmap: account shmem thp pages
...
Before, the stack protector flag was sanity checked before .config had
been reprocessed. This meant the build couldn't be aborted early, and
only a warning could be emitted followed later by the compiler blowing
up with an unknown flag. This has caused a lot of confusion over time,
so this splits the flag selection from sanity checking and performs the
sanity checking after the make has been restarted from a reprocessed
.config, so builds can be aborted as early as possible now.
Additionally moves the x86-specific sanity check to the same location,
since it suffered from the same warn-then-wait-for-compiler-failure
problem.
Link: http://lkml.kernel.org/r/20160712223043.GA11664@www.outflux.net
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Michal Marek <mmarek@suse.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Before, the stack protector flag was sanity checked before .config had
been reprocessed. This meant the build couldn't be aborted early, and
only a warning could be emitted followed later by the compiler blowing
up with an unknown flag. This has caused a lot of confusion over time,
so this splits the flag selection from sanity checking and performs the
sanity checking after the make has been restarted from a reprocessed
.config, so builds can be aborted as early as possible now.
Additionally moves the x86-specific sanity check to the same location,
since it suffered from the same warn-then-wait-for-compiler-failure
problem.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Michal Marek <mmarek@suse.com>
documentation mechanism based on the Sphinx system. The objectives here
are to make it easier to create better-integrated (and more attractive)
documents while (eventually) dumping our one-of-a-kind, cobbled-together
system for something that is widely used and maintained by others. There's
a fair amount of information what's being done, why, and how to use it in:
https://lwn.net/Articles/692704/https://lwn.net/Articles/692705/
Closer to home, Documentation/kernel-documentation.rst describes how it
works.
For now, the new system exists alongside the old one; you should soon see
the GPU documentation converted over in the DRM pull and some significant
media conversion work as well. Once all the docs have been moved over and
we're convinced that the rough edges (of which are are a few) have been
smoothed over, the DocBook-based stuff should go away.
Primary credit is to Jani Nikula for doing the heavy lifting to make this
stuff actually work; there has also been notable effort from Markus Heiser,
Daniel Vetter, and Mauro Carvalho Chehab.
Expect a couple of conflicts on the new index.rst file over the course of
the merge window; they are trivially resolvable. That file may be a bit of
a conflict magnet in the short term, but I don't expect that situation to
last for any real length of time.
Beyond that, of course, we have the usual collection of tweaks, updates,
and typo fixes.
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Merge tag 'docs-for-linus' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"Some big changes this month, headlined by the addition of a new
formatted documentation mechanism based on the Sphinx system.
The objectives here are to make it easier to create better-integrated
(and more attractive) documents while (eventually) dumping our
one-of-a-kind, cobbled-together system for something that is widely
used and maintained by others. There's a fair amount of information
what's being done, why, and how to use it in:
https://lwn.net/Articles/692704/https://lwn.net/Articles/692705/
Closer to home, Documentation/kernel-documentation.rst describes how
it works.
For now, the new system exists alongside the old one; you should soon
see the GPU documentation converted over in the DRM pull and some
significant media conversion work as well. Once all the docs have
been moved over and we're convinced that the rough edges (of which are
are a few) have been smoothed over, the DocBook-based stuff should go
away.
Primary credit is to Jani Nikula for doing the heavy lifting to make
this stuff actually work; there has also been notable effort from
Markus Heiser, Daniel Vetter, and Mauro Carvalho Chehab.
Expect a couple of conflicts on the new index.rst file over the course
of the merge window; they are trivially resolvable. That file may be
a bit of a conflict magnet in the short term, but I don't expect that
situation to last for any real length of time.
Beyond that, of course, we have the usual collection of tweaks,
updates, and typo fixes"
* tag 'docs-for-linus' of git://git.lwn.net/linux: (77 commits)
doc-rst: kernel-doc: fix handling of address_space tags
Revert "doc/sphinx: Enable keep_warnings"
doc-rst: kernel-doc directive, fix state machine reporter
docs: deprecate kernel-doc-nano-HOWTO.txt
doc/sphinx: Enable keep_warnings
Documentation: add watermark_scale_factor to the list of vm systcl file
kernel-doc: Fix up warning output
docs: Get rid of some kernel-documentation warnings
doc-rst: add an option to ignore DocBooks when generating docs
workqueue: Fix a typo in workqueue.txt
Doc: ocfs: Fix typo in filesystems/ocfs2-online-filecheck.txt
Documentation/sphinx: skip build if user requested specific DOCBOOKS
Documentation: add cleanmediadocs to the documentation targets
Add .pyc files to .gitignore
Doc: PM: Fix a typo in intel_powerclamp.txt
doc-rst: flat-table directive - initial implementation
Documentation: add meta-documentation for Sphinx and kernel-doc
Documentation: tiny typo fix in usb/gadget_multi.txt
Documentation: fix wrong value in md.txt
bcache: documentation formatting, edited for clarity, stripe alignment notes
...
Pull perf updates from Ingo Molnar:
"With over 300 commits it's been a busy cycle - with most of the work
concentrated on the tooling side (as it should).
The main kernel side enhancements were:
- Add per event callchain limit: Recently we introduced a sysctl to
tune the max-stack for all events for which callchains were
requested:
$ sysctl kernel.perf_event_max_stack
kernel.perf_event_max_stack = 127
Now this patch introduces a way to configure this per event, i.e.
this becomes possible:
$ perf record -e sched:*/max-stack=2/ -e block:*/max-stack=10/ -a
allowing finer tuning of how much buffer space callchains use.
This uses an u16 from the reserved space at the end, leaving
another u16 for future use.
There has been interest in even finer tuning, namely to control the
max stack for kernel and userspace callchains separately. Further
discussion is needed, we may for instance use the remaining u16 for
that and when it is present, assume that the sample_max_stack
introduced in this patch applies for the kernel, and the u16 left
is used for limiting the userspace callchain (Arnaldo Carvalho de
Melo)
- Optimize AUX event (hardware assisted side-band event) delivery
(Kan Liang)
- Rework Intel family name macro usage (this is partially x86 arch
work) (Dave Hansen)
- Refine and fix Intel LBR support (David Carrillo-Cisneros)
- Add support for Intel 'TopDown' events (Andi Kleen)
- Intel uncore PMU driver fixes and enhancements (Kan Liang)
- ... other misc changes.
Here's an incomplete list of the tooling enhancements (but there's
much more, see the shortlog and the git log for details):
- Support cross unwinding, i.e. collecting '--call-graph dwarf'
perf.data files in one machine and then doing analysis in another
machine of a different hardware architecture. This enables, for
instance, to do:
$ perf record -a --call-graph dwarf
on a x86-32 or aarch64 system and then do 'perf report' on it on a
x86_64 workstation (He Kuang)
- Allow reading from a backward ring buffer (one setup via
sys_perf_event_open() with perf_event_attr.write_backward = 1)
(Wang Nan)
- Finish merging initial SDT (Statically Defined Traces) support, see
cset comments for details about how it all works (Masami Hiramatsu)
- Support attaching eBPF programs to tracepoints (Wang Nan)
- Add demangling of symbols in programs written in the Rust language
(David Tolnay)
- Add support for tracepoints in the python binding, including an
example, that sets up and parses sched:sched_switch events,
tools/perf/python/tracepoint.py (Jiri Olsa)
- Introduce --stdio-color to set up the color output mode selection
in 'annotate' and 'report', allowing emit color escape sequences
when redirecting the output of these tools (Arnaldo Carvalho de
Melo)
- Add 'callindent' option to 'perf script -F', to indent the Intel PT
call stack, making this output more ftrace-like (Adrian Hunter,
Andi Kleen)
- Allow dumping the object files generated by llvm when processing
eBPF scriptlet events (Wang Nan)
- Add stackcollapse.py script to help generating flame graphs (Paolo
Bonzini)
- Add --ldlat option to 'perf mem' to specify load latency for loads
event (e.g. cpu/mem-loads/ ) (Jiri Olsa)
- Tooling support for Intel TopDown counters, recently added to the
kernel (Andi Kleen)"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (303 commits)
perf tests: Add is_printable_array test
perf tools: Make is_printable_array global
perf script python: Fix string vs byte array resolving
perf probe: Warn unmatched function filter correctly
perf cpu_map: Add more helpers
perf stat: Balance opening and reading events
tools: Copy linux/{hash,poison}.h and check for drift
perf tools: Remove include/linux/list.h from perf's MANIFEST
tools: Copy the bitops files accessed from the kernel and check for drift
Remove: kernel unistd*h files from perf's MANIFEST, not used
perf tools: Remove tools/perf/util/include/linux/const.h
perf tools: Remove tools/perf/util/include/asm/byteorder.h
perf tools: Add missing linux/compiler.h include to perf-sys.h
perf jit: Remove some no-op error handling
perf jit: Add missing curly braces
objtool: Initialize variable to silence old compiler
objtool: Add -I$(srctree)/tools/arch/$(ARCH)/include/uapi
perf record: Add --tail-synthesize option
perf session: Don't warn about out of order event if write_backward is used
perf tools: Enable overwrite settings
...
Olof's build test setup keeps failing to compile arm64 kernels
because of a toolchain that uses outdated kernel headers:
/work/build/batch/samples/seccomp/bpf-fancy.c:13:27: fatal error: linux/seccomp.h: No such file or directory
This is of course something he could change, but it also indicates
that others may run into the same problem. Running 'make headers_install'
avoids the issue by ensuring that the kernel headers are put into
the $(objdir)/usr/include path before we build the samples.
The same problem happened for the Documentation build in the
past and was fixed up with commit 8e2faea877 ("Make Documenation
depend on headers_install"). This adds an identical Makefile dependency
for the samples/ subdirectory.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michal Marek <mmarek@suse.com>
When $(LINUXINCLUDE) is added to the cflags of a target that
normall doesn't have it (e.g. HOSTCFLAGS), each entry in the
list is expanded so that we search both $(objtree) and $(srctree),
which is a bit silly, as we already know which of the two we
want for each entry in LINUXINCLUDE.
Also, a follow-up patch changes the behavior so we only look in
$(srctree) for manually added include path, and that breaks finding
the generated headers.
This adds an explicit $(objtree) for each tree that we want to
look for generated files.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michal Marek <mmarek@suse.com>
arch/$(hdr-arch)/include/generated/uapi is included twice in the
header search path, which is unnecessary, so this changes the
top-level Makefile to drop the second instance by filtering out
everything from USERINCLUDE that was already part of LINUXINCLUDE.
This should have very little effect other than making the 'make V=1'
output slightly smaller and making the build time faster by a miniscule
amount, but it seems to be cleaner.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michal Marek <mmarek@suse.com>
This was broken when updating the documentation targets for the Sphinx
build, and moving from %docs target pattern to explicitly listed
targets.
Cc: Markus Heiser <markus.heiser@darmarit.de>
Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Fixes: 22cba31bae ("Documentation/sphinx: add basic working Sphinx configuration and build")
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Pull kbuild regression fix from Michal Marek:
"The problem is that commit 9c8fa9bc08 ("kbuild: fix if_change and
friends to consider argument order") fixed a potential missed rebuild,
but this results in unnnecessary rebuilds with the packaging targets.
Which is still more correct than the previous logic, but also very
annoying"
* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kbuild: Initialize exported variables
While there's slight overlap with the DocBook help now, this can stay
intact when the DocBook help goes away.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
On openSUSE, the libelf development files are in package libelf-devel.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Michal Marek <mmarek@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kbuild@vger.kernel.org
Link: http://lkml.kernel.org/n/tip-s8nyk3pyy2927sd7qp7u42oi@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The NOSTDINC_FLAGS variable is exported, so it needs to be cleared to
avoid duplicating its content when running make from within make (e.g.
in the packaging targets). This became an issue after commit
9c8fa9bc08 ("kbuild: fix if_change and friends to consider argument
order"), which no longer ignores the duplicate options. As Paulo Zanoni
points out, the LDFLAGS_vmlinux variable has the same problem.
Reported-by: "Zanoni, Paulo R" <paulo.r.zanoni@intel.com>
Fixes: 9c8fa9bc08 ("kbuild: fix if_change and friends to consider argument order")
Signed-off-by: Michal Marek <mmarek@suse.com>
The sancov gcc plugin inserts a __sanitizer_cov_trace_pc() call
at the start of basic blocks.
This plugin is a helper plugin for the kcov feature. It supports
all gcc versions with plugin support (from gcc-4.5 on).
It is based on the gcc commit "Add fuzzing coverage support" by Dmitry Vyukov
(https://gcc.gnu.org/viewcvs/gcc?limit_changes=0&view=revision&revision=231296).
Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Michal Marek <mmarek@suse.com>
This patch allows to build the whole kernel with GCC plugins. It was ported from
grsecurity/PaX. The infrastructure supports building out-of-tree modules and
building in a separate directory. Cross-compilation is supported too.
Currently the x86, arm, arm64 and uml architectures enable plugins.
The directory of the gcc plugins is scripts/gcc-plugins. You can use a file or a directory
there. The plugins compile with these options:
* -fno-rtti: gcc is compiled with this option so the plugins must use it too
* -fno-exceptions: this is inherited from gcc too
* -fasynchronous-unwind-tables: this is inherited from gcc too
* -ggdb: it is useful for debugging a plugin (better backtrace on internal
errors)
* -Wno-narrowing: to suppress warnings from gcc headers (ipa-utils.h)
* -Wno-unused-variable: to suppress warnings from gcc headers (gcc_version
variable, plugin-version.h)
The infrastructure introduces a new Makefile target called gcc-plugins. It
supports all gcc versions from 4.5 to 6.0. The scripts/gcc-plugin.sh script
chooses the proper host compiler (gcc-4.7 can be built by either gcc or g++).
This script also checks the availability of the included headers in
scripts/gcc-plugins/gcc-common.h.
The gcc-common.h header contains frequently included headers for GCC plugins
and it has a compatibility layer for the supported gcc versions.
The gcc-generate-*-pass.h headers automatically generate the registration
structures for GIMPLE, SIMPLE_IPA, IPA and RTL passes.
Note that 'make clean' keeps the *.so files (only the distclean or mrproper
targets clean all) because they are needed for out-of-tree modules.
Based on work created by the PaX Team.
Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Michal Marek <mmarek@suse.com>
Add basic configuration and makefile to build documentation from any
.rst files under Documentation using Sphinx. For starters, there's just
the placeholder index.rst.
At the top level Makefile, hook Sphinx documentation targets alongside
(but independent of) the DocBook toolchain, having both be run on the
various 'make *docs' targets.
All Sphinx processing is placed into Documentation/Makefile.sphinx. Both
that and the Documentation/DocBook/Makefile are now expected to handle
all the documentation targets, explicitly ignoring them if they're not
relevant for that particular toolchain. The changes to the existing
DocBook Makefile are kept minimal.
There is graceful handling of missing Sphinx and rst2pdf (which is
needed for pdf output) by checking for the tool and python module,
respectively, with informative messages to the user.
If the Read the Docs theme (sphinx_rtd_theme) is available, use it, but
otherwise gracefully fall back to the Sphinx default theme, with an
informative message to the user, and slightly less pretty HTML output.
Sphinx can now handle htmldocs, pdfdocs (if rst2pdf is available),
epubdocs and xmldocs targets. The output documents are written into per
output type subdirectories under Documentation/output.
Finally, you can pass options to sphinx-build using the SPHINXBUILD make
variable. For example, 'make SPHINXOPTS=-v htmldocs' for more verbose
output from Sphinx.
This is based on the original work by Jonathan Corbet, but he probably
wouldn't recognize this as his own anymore.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Pull kbuild updates from Michal Marek:
- new option CONFIG_TRIM_UNUSED_KSYMS which does a two-pass build and
unexports symbols which are not used in the current config [Nicolas
Pitre]
- several kbuild rule cleanups [Masahiro Yamada]
- warning option adjustments for gcov etc [Arnd Bergmann]
- a few more small fixes
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (31 commits)
kbuild: move -Wunused-const-variable to W=1 warning level
kbuild: fix if_change and friends to consider argument order
kbuild: fix adjust_autoksyms.sh for modules that need only one symbol
kbuild: fix ksym_dep_filter when multiple EXPORT_SYMBOL() on the same line
gcov: disable -Wmaybe-uninitialized warning
gcov: disable tree-loop-im to reduce stack usage
gcov: disable for COMPILE_TEST
Kbuild: disable 'maybe-uninitialized' warning for CONFIG_PROFILE_ALL_BRANCHES
Kbuild: change CC_OPTIMIZE_FOR_SIZE definition
kbuild: forbid kernel directory to contain spaces and colons
kbuild: adjust ksym_dep_filter for some cmd_* renames
kbuild: Fix dependencies for final vmlinux link
kbuild: better abstract vmlinux sequential prerequisites
kbuild: fix call to adjust_autoksyms.sh when output directory specified
kbuild: Get rid of KBUILD_STR
kbuild: rename cmd_as_s_S to cmd_cpp_s_S
kbuild: rename cmd_cc_i_c to cmd_cpp_i_c
kbuild: drop redundant "PHONY += FORCE"
kbuild: delete unnecessary "@:"
kbuild: mark help target as PHONY
...
gcc-6 started warning by default about variables that are not
used anywhere and that are marked 'const', generating many
false positives in an allmodconfig build, e.g.:
arch/arm/mach-davinci/board-da830-evm.c:282:20: warning: 'da830_evm_emif25_pins' defined but not used [-Wunused-const-variable=]
arch/arm/plat-omap/dmtimer.c:958:34: warning: 'omap_timer_match' defined but not used [-Wunused-const-variable=]
drivers/bluetooth/hci_bcm.c:625:39: warning: 'acpi_bcm_default_gpios' defined but not used [-Wunused-const-variable=]
drivers/char/hw_random/omap-rng.c:92:18: warning: 'reg_map_omap4' defined but not used [-Wunused-const-variable=]
drivers/devfreq/exynos/exynos5_bus.c:381:32: warning: 'exynos5_busfreq_int_pm' defined but not used [-Wunused-const-variable=]
drivers/dma/mv_xor.c:1139:34: warning: 'mv_xor_dt_ids' defined but not used [-Wunused-const-variable=]
This is similar to the existing -Wunused-but-set-variable warning
that was added in an earlier release and that we disable by default
now and only enable when W=1 is set, so it makes sense to do
the same here. Once we have eliminated the majority of the
warnings for both, we can put them back into the default list.
We probably want this in backport kernels as well, to allow building
them with gcc-6 without introducing extra warnings.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Lee Jones <lee.jones@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Michal Marek <mmarek@suse.com>
When gcov profiling is enabled, we see a lot of spurious warnings about
possibly uninitialized variables being used:
arch/arm/mm/dma-mapping.c: In function 'arm_coherent_iommu_map_page':
arch/arm/mm/dma-mapping.c:1085:16: warning: 'start' may be used uninitialized in this function [-Wmaybe-uninitialized]
drivers/clk/st/clk-flexgen.c: In function 'st_of_flexgen_setup':
drivers/clk/st/clk-flexgen.c:323:9: warning: 'num_parents' may be used uninitialized in this function [-Wmaybe-uninitialized]
kernel/cgroup.c: In function 'cgroup_mount':
kernel/cgroup.c:2119:11: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized]
All of these are false positives, so it seems better to just disable
the warnings whenever GCOV is enabled. Most users don't enable GCOV,
and based on a prior patch, it is now also disabled for 'allmodconfig'
builds, so there should be no downsides of doing this.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
Enabling CONFIG_GCOV_PROFILE_ALL produces us a lot of warnings like
lib/lz4/lz4hc_compress.c: In function 'lz4_compresshcctx':
lib/lz4/lz4hc_compress.c:514:1: warning: the frame size of 1504 bytes is larger than 1024 bytes [-Wframe-larger-than=]
After some investigation, I found that this behavior started with gcc-4.9,
and opened https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69702.
A suggested workaround for it is to use the -fno-tree-loop-im
flag that turns off one of the optimization stages in gcc, so the
code runs a little slower but does not use excessive amounts
of stack.
We could make this conditional on the gcc version, but I could not
find an easy way to do this in Kbuild and the benefit would be
fairly small, given that most of the gcc version in production are
affected now.
I'm marking this for 'stable' backports because it addresses a bug
with code generation in gcc that exists in all kernel versions
with the affected gcc releases.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Michal Marek <mmarek@suse.com>
CONFIG_PROFILE_ALL_BRANCHES confuses gcc-5.x to the degree that it prints
incorrect warnings about a lot of variables that it thinks can be used
uninitialized, e.g.:
i2c/busses/i2c-diolan-u2c.c: In function 'diolan_usb_xfer':
i2c/busses/i2c-diolan-u2c.c:391:16: warning: 'byte' may be used uninitialized in this function
iio/gyro/itg3200_core.c: In function 'itg3200_probe':
iio/gyro/itg3200_core.c:213:6: warning: 'val' may be used uninitialized in this function
leds/leds-lp55xx-common.c: In function 'lp55xx_update_bits':
leds/leds-lp55xx-common.c:350:6: warning: 'tmp' may be used uninitialized in this function
misc/bmp085.c: In function 'show_pressure':
misc/bmp085.c:363:10: warning: 'pressure' may be used uninitialized in this function
power/ds2782_battery.c: In function 'ds2786_get_capacity':
power/ds2782_battery.c:214:17: warning: 'raw' may be used uninitialized in this function
These are all false positives that either rob someone's time when trying
to figure out whether they are real, or they get people to send wrong
patches to shut up the warnings.
Nobody normally wants to run a CONFIG_PROFILE_ALL_BRANCHES kernel in
production, so disabling the whole class of warnings for this configuration
has no serious downsides either.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Steven Rostedt <rostedtgoodmis.org>
Signed-off-by: Michal Marek <mmarek@suse.com>
When the kernel path contains a space or a colon somewhere in the path
name, the modules_install target doesn't work anymore, as the path names
are not enclosed in double quotes. It is also supposed that and O= build
will suffer from the same weakness as modules_install.
Instead of checking and improving kbuild to resist to directories
including these characters, error out early to prevent any build if the
kernel's main directory contains a space.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
The if_changed directive is useless against phony targets.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 2441e78b19 ("kbuild: better abstract vmlinux sequential prerequisites")
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
When CONFIG_TRIM_UNUSED_KSYMS=y and CONFIG_BUILD_DOCSRC=y it is possible
to get the following error:
ERROR: "cn_del_callback" [Documentation/connector/cn_test.ko] undefined!
ERROR: "cn_add_callback" [Documentation/connector/cn_test.ko] undefined!
ERROR: "cn_netlink_send" [Documentation/connector/cn_test.ko] undefined!
../scripts/Makefile.modpost:91: recipe for target '__modpost' failed
It is not sufficient to do "vmlinux-dirs += Documentation" as this also
depends on the headers_check target, and all of this needs to be done
before adjust_autoksyms.sh is executed.
Let's sort this out by gathering those sequential prerequisites in a make
target of their own, separate from the vmlinux target. And by doing so,
the special autoksyms_recursive target is no longer needed.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
When a different output directory is specified during the build process (with
O= or KBUILD_OUTPUT), the call to adjust_autoksyms.sh script fails with the
following error:
/bin/sh scripts/adjust_autoksyms.sh \
"make KBUILD_MODULES=1 -f ../Makefile autoksyms_recursive"
/bin/sh: scripts/adjust_autoksyms.sh: No such file or directory
make[2]: *** [vmlinux] Error 127
make[1]: *** [sub-make] Error 2
make: *** [__sub-make] Error 2
Using the absolute path with $(srctree) variable solves the problem.
This is in case the CONFIG_TRIM_UNUSED_KSYMS option is specified.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Fixes: 23121ca2b5 ("kbuild: create/adjust generated/autoksyms.h")
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Michal Marek <mmarek@suse.com>
Pull objtool fixes from Ingo Molnar:
"A handful of objtool fixes: two improvements to how warnings are
printed plus a false positive warning fix, and build environment fix"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool: Fix Makefile to properly see if libelf is supported
objtool: Detect falling through to the next function
objtool: Add workaround for GCC switch jump table bug
When doing a make allmodconfig, I hit the following compile error:
In file included from builtin-check.c:32:0:
elf.h:22:18: fatal error: gelf.h: No such file or directory
compilation terminated.
...
Digging into it, it appears that the $(shell ..) command in the Makefile does
not give the proper result when it fails to find -lelf, and continues to
compile objtool.
Instead, use the "try-run" makefile macro to perform the test. This gives a
proper result for both cases.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Fixes: 442f04c34a ("objtool: Add tool to perform compile-time stack metadata validation")
Link: http://lkml.kernel.org/r/20160420153234.GA24032@home.goodmis.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Obviously, the "help" should be a PHONY target.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
As in other places, PHONY is a better fit for "modules" and
"modules_install".
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
These targets are marked as PHONY. No need to add FORCE to their
dependency.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
Make sample modules in parallel with the rest of the kernel rather
than having them built from the vmlinux target. This makes the build
slightly faster, and those modules are properly considered when
adjust_autoksyms.sh is executed.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Given the list of exported symbols needed by all modules, we can create
a header file containing preprocessor defines for each of those symbols.
Also, when some symbols are added and/or removed from the list, we can
update the time on the corresponding files used as build dependencies for
those symbols. And finally, if any symbol did change state, the
corresponding source files must be rebuilt.
The insertion or removal of an EXPORT_SYMBOL() entry within a module may
create or remove the need for another exported symbol. This is why this
operation has to be repeated until the list of needed exported symbols
becomes stable. Only then the final kernel and modules link take place.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Similar to include/generated/autoconf.h, include/generated/autoksyms.h
will contain a list of defines for each EXPORT_SYMBOL() that we want
active. The format is:
#define __KSYM_<symbol_name> 1
This list will be auto-generated with another patch. For now we only
include the preprocessor magic to automatically create or omit the
corresponding struct kernel_symbol declaration.
Given the content of include/generated/autoksyms.h may not be known in
advance, an empty file is created early on to let the build proceed.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Pull kbuild updates from Michal Marek:
- make dtbs_install fix
- Error handling fix fixdep and link-vmlinux.sh
- __UNIQUE_ID fix for clang
- Fix for if_changed_* to suppress the "is up to date." message
- The kernel is built with -Werror=incompatible-pointer-types
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kbuild: Add option to turn incompatible pointer check into error
kbuild: suppress annoying "... is up to date." message
kbuild: fixdep: Check fstat(2) return value
scripts/link-vmlinux.sh: force error on kallsyms failure
Kbuild: provide a __UNIQUE_ID for clang
dtbsinstall: don't move target directory out of the way
kcov provides code coverage collection for coverage-guided fuzzing
(randomized testing). Coverage-guided fuzzing is a testing technique
that uses coverage feedback to determine new interesting inputs to a
system. A notable user-space example is AFL
(http://lcamtuf.coredump.cx/afl/). However, this technique is not
widely used for kernel testing due to missing compiler and kernel
support.
kcov does not aim to collect as much coverage as possible. It aims to
collect more or less stable coverage that is function of syscall inputs.
To achieve this goal it does not collect coverage in soft/hard
interrupts and instrumentation of some inherently non-deterministic or
non-interesting parts of kernel is disbled (e.g. scheduler, locking).
Currently there is a single coverage collection mode (tracing), but the
API anticipates additional collection modes. Initially I also
implemented a second mode which exposes coverage in a fixed-size hash
table of counters (what Quentin used in his original patch). I've
dropped the second mode for simplicity.
This patch adds the necessary support on kernel side. The complimentary
compiler support was added in gcc revision 231296.
We've used this support to build syzkaller system call fuzzer, which has
found 90 kernel bugs in just 2 months:
https://github.com/google/syzkaller/wiki/Found-Bugs
We've also found 30+ bugs in our internal systems with syzkaller.
Another (yet unexplored) direction where kcov coverage would greatly
help is more traditional "blob mutation". For example, mounting a
random blob as a filesystem, or receiving a random blob over wire.
Why not gcov. Typical fuzzing loop looks as follows: (1) reset
coverage, (2) execute a bit of code, (3) collect coverage, repeat. A
typical coverage can be just a dozen of basic blocks (e.g. an invalid
input). In such context gcov becomes prohibitively expensive as
reset/collect coverage steps depend on total number of basic
blocks/edges in program (in case of kernel it is about 2M). Cost of
kcov depends only on number of executed basic blocks/edges. On top of
that, kernel requires per-thread coverage because there are always
background threads and unrelated processes that also produce coverage.
With inlined gcov instrumentation per-thread coverage is not possible.
kcov exposes kernel PCs and control flow to user-space which is
insecure. But debugfs should not be mapped as user accessible.
Based on a patch by Quentin Casasnovas.
[akpm@linux-foundation.org: make task_struct.kcov_mode have type `enum kcov_mode']
[akpm@linux-foundation.org: unbreak allmodconfig]
[akpm@linux-foundation.org: follow x86 Makefile layout standards]
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: syzkaller <syzkaller@googlegroups.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Tavis Ormandy <taviso@google.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@google.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: David Drysdale <drysdale@google.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull 'objtool' stack frame validation from Ingo Molnar:
"This tree adds a new kernel build-time object file validation feature
(ONFIG_STACK_VALIDATION=y): kernel stack frame correctness validation.
It was written by and is maintained by Josh Poimboeuf.
The motivation: there's a category of hard to find kernel bugs, most
of them in assembly code (but also occasionally in C code), that
degrades the quality of kernel stack dumps/backtraces. These bugs are
hard to detect at the source code level. Such bugs result in
incorrect/incomplete backtraces most of time - but can also in some
rare cases result in crashes or other undefined behavior.
The build time correctness checking is done via the new 'objtool'
user-space utility that was written for this purpose and which is
hosted in the kernel repository in tools/objtool/. The tool's (very
simple) UI and source code design is shaped after Git and perf and
shares quite a bit of infrastructure with tools/perf (which tooling
infrastructure sharing effort got merged via perf and is already
upstream). Objtool follows the well-known kernel coding style.
Objtool does not try to check .c or .S files, it instead analyzes the
resulting .o generated machine code from first principles: it decodes
the instruction stream and interprets it. (Right now objtool supports
the x86-64 architecture.)
From tools/objtool/Documentation/stack-validation.txt:
"The kernel CONFIG_STACK_VALIDATION option enables a host tool named
objtool which runs at compile time. It has a "check" subcommand
which analyzes every .o file and ensures the validity of its stack
metadata. It enforces a set of rules on asm code and C inline
assembly code so that stack traces can be reliable.
Currently it only checks frame pointer usage, but there are plans to
add CFI validation for C files and CFI generation for asm files.
For each function, it recursively follows all possible code paths
and validates the correct frame pointer state at each instruction.
It also follows code paths involving special sections, like
.altinstructions, __jump_table, and __ex_table, which can add
alternative execution paths to a given instruction (or set of
instructions). Similarly, it knows how to follow switch statements,
for which gcc sometimes uses jump tables."
When this new kernel option is enabled (it's disabled by default), the
tool, if it finds any suspicious assembly code pattern, outputs
warnings in compiler warning format:
warning: objtool: rtlwifi_rate_mapping()+0x2e7: frame pointer state mismatch
warning: objtool: cik_tiling_mode_table_init()+0x6ce: call without frame pointer save/setup
warning: objtool:__schedule()+0x3c0: duplicate frame pointer save
warning: objtool:__schedule()+0x3fd: sibling call from callable instruction with changed frame pointer
... so that scripts that pick up compiler warnings will notice them.
All known warnings triggered by the tool are fixed by the tree, most
of the commits in fact prepare the kernel to be warning-free. Most of
them are bugfixes or cleanups that stand on their own, but there are
also some annotations of 'special' stack frames for justified cases
such entries to JIT-ed code (BPF) or really special boot time code.
There are two other long-term motivations behind this tool as well:
- To improve the quality and reliability of kernel stack frames, so
that they can be used for optimized live patching.
- To create independent infrastructure to check the correctness of
CFI stack frames at build time. CFI debuginfo is notoriously
unreliable and we cannot use it in the kernel as-is without extra
checking done both on the kernel side and on the build side.
The quality of kernel stack frames matters to debuggability as well,
so IMO we can merge this without having to consider the live patching
or CFI debuginfo angle"
* 'core-objtool-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
objtool: Only print one warning per function
objtool: Add several performance improvements
tools: Copy hashtable.h into tools directory
objtool: Fix false positive warnings for functions with multiple switch statements
objtool: Rename some variables and functions
objtool: Remove superflous INIT_LIST_HEAD
objtool: Add helper macros for traversing instructions
objtool: Fix false positive warnings related to sibling calls
objtool: Compile with debugging symbols
objtool: Detect infinite recursion
objtool: Prevent infinite recursion in noreturn detection
objtool: Detect and warn if libelf is missing and don't break the build
tools: Support relative directory path for 'O='
objtool: Support CROSS_COMPILE
x86/asm/decoder: Use explicitly signed chars
objtool: Enable stack metadata validation on 64-bit x86
objtool: Add CONFIG_STACK_VALIDATION option
objtool: Add tool to perform compile-time stack metadata validation
x86/kprobes: Mark kretprobe_trampoline() stack frame as non-standard
sched: Always inline context_switch()
...
This update for Kselftest adds:
- A new feature to create test-specific kconfig fragments.
This feature helps configure Kselftests to test specific
Kernel Configuration options as opposed to defconfig.
- A new test for Media Controller API
- A few fixes
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Merge tag 'linux-kselftest-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull Kselftest updates from Shuah Khan:
"This update for Kselftest adds:
- A new feature to create test-specific kconfig fragments. This
feature helps configure Kselftests to test specific Kernel
Configuration options as opposed to defconfig.
- A new test for Media Controller API
- A few fixes"
* tag 'linux-kselftest-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
selftests: media_dcevice_test fix usage information
selftests: media_dcevice_test fix to handle ioctl failure case
selftests: add missing .gitignore file or entry
Makefile: add kselftest-merge
selftests: create test-specific kconfig fragments
selftests: breakpoint: add step_after_suspend_test
selftests: add a new test for Media Controller API
With the introduction of the simple wait API we have two very
similar APIs in the kernel. For example wake_up() and swake_up()
is only one character away. Although the compiler will warn
happily the wrong usage it keeps on going an even links the kernel.
Thomas and Peter would rather like to see early missuses reported
as error early on.
In a first attempt we tried to wrap all swait and wait calls
into a macro which has an compile time type assertion. The result
was pretty ugly and wasn't able to catch all wrong usages.
woken_wake_function(), autoremove_wake_function() and wake_bit_function()
are assigned as function pointers. Wrapping them with a macro around is
not possible. Prefixing them with '_' was also not a real option
because there some users in the kernel which do use them as well.
All in all this attempt looked to intrusive and too ugly.
An alternative is to turn the pointer type check into an error which
catches wrong type uses. Obviously not only the swait/wait ones. That
isn't a bad thing either.
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Michal Marek <mmarek@suse.com>
With CONFIG_STACK_VALIDATION enabled, if the host system doesn't have
a development version of libelf installed, the build fails with errors
like:
elf.h:22:18: fatal error: gelf.h: No such file or directory compilation terminated.
Instead of failing to build, instead just print a warning and disable
stack validation.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-next@vger.kernel.org
Cc: linux@roeck-us.net
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/8c27fe00face60f42e888ddb3142c97e45223165.1457026550.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Running "make O=foo" (with a relative directory path) fails with:
scripts/Makefile.include:3: *** O=foo does not exist. Stop.
/home/jpoimboe/git/linux/Makefile:1547: recipe for target 'tools/objtool' failed
The tools Makefile gets confused by the relative path and tries to build
objtool in tools/foo. Convert the output directory to an absolute path
before passing it to the tools Makefile.
Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-next@vger.kernel.org
Cc: linux@roeck-us.net
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/94a078c6c998fac9f01a14f574008bf7dff40191.1457016803.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add a CONFIG_STACK_VALIDATION option which will run "objtool check" for
each .o file to ensure the validity of its stack metadata.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/92baab69a6bf9bc7043af0bfca9fb964a1d45546.1456719558.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add kselftest-merge to enable the dependencies of kernel config
for all the kselftest testcases. User should call it after create
the kernel configuration(.config), eg:
$ make kselftest-merge
Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
UBSAN uses compile-time instrumentation to catch undefined behavior
(UB). Compiler inserts code that perform certain kinds of checks before
operations that could cause UB. If check fails (i.e. UB detected)
__ubsan_handle_* function called to print error message.
So the most of the work is done by compiler. This patch just implements
ubsan handlers printing errors.
GCC has this capability since 4.9.x [1] (see -fsanitize=undefined
option and its suboptions).
However GCC 5.x has more checkers implemented [2].
Article [3] has a bit more details about UBSAN in the GCC.
[1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html
[2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html
[3] - http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/
Issues which UBSAN has found thus far are:
Found bugs:
* out-of-bounds access - 97840cb67f ("netfilter: nfnetlink: fix
insufficient validation in nfnetlink_bind")
undefined shifts:
* d48458d4a7 ("jbd2: use a better hash function for the revoke
table")
* 10632008b9 ("clockevents: Prevent shift out of bounds")
* 'x << -1' shift in ext4 -
http://lkml.kernel.org/r/<5444EF21.8020501@samsung.com>
* undefined rol32(0) -
http://lkml.kernel.org/r/<1449198241-20654-1-git-send-email-sasha.levin@oracle.com>
* undefined dirty_ratelimit calculation -
http://lkml.kernel.org/r/<566594E2.3050306@odin.com>
* undefined roundown_pow_of_two(0) -
http://lkml.kernel.org/r/<1449156616-11474-1-git-send-email-sasha.levin@oracle.com>
* [WONTFIX] undefined shift in __bpf_prog_run -
http://lkml.kernel.org/r/<CACT4Y+ZxoR3UjLgcNdUm4fECLMx2VdtfrENMtRRCdgHB2n0bJA@mail.gmail.com>
WONTFIX here because it should be fixed in bpf program, not in kernel.
signed overflows:
* 32a8df4e0b ("sched: Fix odd values in effective_load()
calculations")
* mul overflow in ntp -
http://lkml.kernel.org/r/<1449175608-1146-1-git-send-email-sasha.levin@oracle.com>
* incorrect conversion into rtc_time in rtc_time64_to_tm() -
http://lkml.kernel.org/r/<1449187944-11730-1-git-send-email-sasha.levin@oracle.com>
* unvalidated timespec in io_getevents() -
http://lkml.kernel.org/r/<CACT4Y+bBxVYLQ6LtOKrKtnLthqLHcw-BMp3aqP3mjdAvr9FULQ@mail.gmail.com>
* [NOTABUG] signed overflow in ktime_add_safe() -
http://lkml.kernel.org/r/<CACT4Y+aJ4muRnWxsUe1CMnA6P8nooO33kwG-c8YZg=0Xc8rJqw@mail.gmail.com>
[akpm@linux-foundation.org: fix unused local warning]
[akpm@linux-foundation.org: fix __int128 build woes]
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yury Gribov <y.gribov@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull kbuild updates from Michal Marek:
- Make <modname>-m in makefiles work like <modname>-y and fix the
fallout
- Minor genksyms fix
- Fix race with make -j install modules_install
- Move -Wsign-compare from make W=1 to W=2
- Other minor fixes
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kbuild: Demote 'sign-compare' warning to W=2
Makefile: revert "Makefile: Document ability to make file.lst and file.S" partially
kbuild: Do not run modules_install and install in paralel
genksyms: Handle string literals with spaces in reference files
fixdep: constify strrcmp arguments
ath10k: Fix build with CONFIG_THERMAL=m
Revert "drm: Hack around CONFIG_AGP=m build failures"
kbuild: Allow to specify composite modules with modname-m
staging/ad7606: Actually build the interface modules
Commit 6271897978 ("Makefile: Document ability to make file.lst
and file.S") document ability to make file.S, but there isn't such
ability in kbuild, so revert it.
Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
Based on a x86-only patch by Andy Lutomirski <luto@amacapital.net>
With modular kernels, 'make install' is going to need the installed
modules at some point to generate the initramfs.
Signed-off-by: Michal Marek <mmarek@suse.cz>
Pull kbuild update from Michal Marek:
"The kbuild branch for v4.4-rc1 only has one commit: A new make
kselftest-clean target cleans tools/testing/selftests"
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kselftest: add kselftest-clean rule
handling.
PPC: Mostly bug fixes.
ARM: No big features, but many small fixes and prerequisites including:
- a number of fixes for the arch-timer
- introducing proper level-triggered semantics for the arch-timers
- a series of patches to synchronously halt a guest (prerequisite for
IRQ forwarding)
- some tracepoint improvements
- a tweak for the EL2 panic handlers
- some more VGIC cleanups getting rid of redundant state
x86: quite a few changes:
- support for VT-d posted interrupts (i.e. PCI devices can inject
interrupts directly into vCPUs). This introduces a new component (in
virt/lib/) that connects VFIO and KVM together. The same infrastructure
will be used for ARM interrupt forwarding as well.
- more Hyper-V features, though the main one Hyper-V synthetic interrupt
controller will have to wait for 4.5. These will let KVM expose Hyper-V
devices.
- nested virtualization now supports VPID (same as PCID but for vCPUs)
which makes it quite a bit faster
- for future hardware that supports NVDIMM, there is support for clflushopt,
clwb, pcommit
- support for "split irqchip", i.e. LAPIC in kernel + IOAPIC/PIC/PIT in
userspace, which reduces the attack surface of the hypervisor
- obligatory smattering of SMM fixes
- on the guest side, stable scheduler clock support was rewritten to not
require help from the hypervisor.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"First batch of KVM changes for 4.4.
s390:
A bunch of fixes and optimizations for interrupt and time handling.
PPC:
Mostly bug fixes.
ARM:
No big features, but many small fixes and prerequisites including:
- a number of fixes for the arch-timer
- introducing proper level-triggered semantics for the arch-timers
- a series of patches to synchronously halt a guest (prerequisite
for IRQ forwarding)
- some tracepoint improvements
- a tweak for the EL2 panic handlers
- some more VGIC cleanups getting rid of redundant state
x86:
Quite a few changes:
- support for VT-d posted interrupts (i.e. PCI devices can inject
interrupts directly into vCPUs). This introduces a new
component (in virt/lib/) that connects VFIO and KVM together.
The same infrastructure will be used for ARM interrupt
forwarding as well.
- more Hyper-V features, though the main one Hyper-V synthetic
interrupt controller will have to wait for 4.5. These will let
KVM expose Hyper-V devices.
- nested virtualization now supports VPID (same as PCID but for
vCPUs) which makes it quite a bit faster
- for future hardware that supports NVDIMM, there is support for
clflushopt, clwb, pcommit
- support for "split irqchip", i.e. LAPIC in kernel +
IOAPIC/PIC/PIT in userspace, which reduces the attack surface of
the hypervisor
- obligatory smattering of SMM fixes
- on the guest side, stable scheduler clock support was rewritten
to not require help from the hypervisor"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (123 commits)
KVM: VMX: Fix commit which broke PML
KVM: x86: obey KVM_X86_QUIRK_CD_NW_CLEARED in kvm_set_cr0()
KVM: x86: allow RSM from 64-bit mode
KVM: VMX: fix SMEP and SMAP without EPT
KVM: x86: move kvm_set_irq_inatomic to legacy device assignment
KVM: device assignment: remove pointless #ifdefs
KVM: x86: merge kvm_arch_set_irq with kvm_set_msi_inatomic
KVM: x86: zero apic_arb_prio on reset
drivers/hv: share Hyper-V SynIC constants with userspace
KVM: x86: handle SMBASE as physical address in RSM
KVM: x86: add read_phys to x86_emulate_ops
KVM: x86: removing unused variable
KVM: don't pointlessly leave KVM_COMPAT=y in non-KVM configs
KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr()
KVM: arm/arm64: Clean up vgic_retire_lr() and surroundings
KVM: arm/arm64: Optimize away redundant LR tracking
KVM: s390: use simple switch statement as multiplexer
KVM: s390: drop useless newline in debugging data
KVM: s390: SCA must not cross page boundaries
KVM: arm: Do not indent the arguments of DECLARE_BITMAP
...
some new CAN driver documentation. Beyond that, we have kernel-doc fixes,
a bit more work to support reproducible builds, and the usual collection of
small fixes.
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Merge tag 'docs-for-linus' of git://git.lwn.net/linux
Pull documentation update from Jon Corbet:
"There is a nice new document from Neil on how pathname lookups work
and some new CAN driver documentation. Beyond that, we have
kernel-doc fixes, a bit more work to support reproducible builds, and
the usual collection of small fixes"
* tag 'docs-for-linus' of git://git.lwn.net/linux: (34 commits)
Documentation: add new description of path-name lookup.
Documentation/vm/slub.txt: document slabinfo-gnuplot.sh
Doc: ABI/stable: Fix typo in ABI/stable
doc: Clarify that nmi_watchdog param is for hardlockups
Typo correction for description in gpio document.
DocBook: Fix kernel-doc to be case-insensitive for private:
kernel-docs.txt: update kernelnewbies reference
Doc:kvm: Fix typo in Doc/virtual/kvm
Documentation/Changes: Add bc in "Current Minimal Requirements" section
Documentation/email-clients.txt: remove trailing whitespace
DocBook: Use a fixed encoding for output
MAINTAINERS: The docs tree has moved
Docs/kernel-parameters: Add earlycon devicetree usage
SubmittingPatches: make Subject examples match the de facto standard
Documentation: gpio: mention that <function>-gpio has been deprecated
Documentation: cgroups: just fix a few typos
Documentation: Update kselftest.txt
Documentation: DMA API: Be more explicit that nents is always the same
Documentation: Update the default value of crashkernel low
zram: update documentation
...
We use
$make TARGETS="size timers" kselftest
to build and run selftests. but there is no rule
for us to clean the kselftest generated files.
This patch add the rules, for example:
$ make TARGETS="size timers" kselftest-clean
can clean all kselftest generated files.
Signed-off-by: Wang Long <long.wanglong@huawei.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michal Marek <mmarek@suse.com>
We need to build files in virt/lib/, which are now used by
KVM and VFIO, so add virt directory to the top Makefile.
Signed-off-by: Feng Wu <feng.wu@intel.com>
Acked-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently the encoding of documents generated by DocBook depends on
the current locale. Make the output reproducible independently of
the locale, by setting the encoding to UTF-8 (LC_CTYPE=C.UTF-8) by
preference, or ASCII (LC_CTYPE=C) as a fallback.
LC_CTYPE can normally be overridden by LC_ALL, but the top-level
Makefile unsets that.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[jc: added check-lc_ctype to .gitignore]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Pull misc kbuild updates from Michal Marek:
- deb-pkg:
+ module signing fix
+ dtb files are added to the package
+ do not require `hostname -f` to work during build
+ make deb-pkg generates a source package, bindeb-pkg has been
added to only generate the binary package
- rpm-pkg packages /lib/modules as well
- new coccinelle patch and updates to existing ones
- new stackusage & stackdelta script to collect and compare stack usage
info (using gcc's -fstack-usage)
- make tags understands trace_*_rcuidle() macros
- .gitignore updates, misc cleanups
* 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (27 commits)
deb-pkg: add source package
package/Makefile: move source tar creation to a function
scripts: add stackdelta script
kbuild: remove *.su files generated by -fstack-usage
.gitignore: add *.su pattern
scripts: add stackusage script
kbuild: avoid listing /lib/modules in kernel spec file
fallback to hostname in scripts/package/builddeb
coccinelle: api: extend spatch for dropping unnecessary owner
deb-pkg: simplify directory creation
scripts/tags.sh: Include trace_*_rcuidle() in tags
scripts/package/Makefile: rpmbuild is needed for rpm targets
Kbuild: Add ID files to .gitignore
gitignore: Add MIPS vmlinux.32 to the list
coccinelle: simple_return: Add a blank line
coccinelle: irqf_oneshot.cocci: Improve the generated commit log
coccinelle: api: add vma_pages.cocci
scripts/coccinelle/misc/irqf_oneshot.cocci: Fix grammar
scripts/coccinelle/misc/semicolon.cocci: Use imperative mood
coccinelle: simple_open: Use imperative mood
...
Pull security subsystem updates from James Morris:
"Highlights:
- PKCS#7 support added to support signed kexec, also utilized for
module signing. See comments in 3f1e1bea.
** NOTE: this requires linking against the OpenSSL library, which
must be installed, e.g. the openssl-devel on Fedora **
- Smack
- add IPv6 host labeling; ignore labels on kernel threads
- support smack labeling mounts which use binary mount data
- SELinux:
- add ioctl whitelisting (see
http://kernsec.org/files/lss2015/vanderstoep.pdf)
- fix mprotect PROT_EXEC regression caused by mm change
- Seccomp:
- add ptrace options for suspend/resume"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (57 commits)
PKCS#7: Add OIDs for sha224, sha284 and sha512 hash algos and use them
Documentation/Changes: Now need OpenSSL devel packages for module signing
scripts: add extract-cert and sign-file to .gitignore
modsign: Handle signing key in source tree
modsign: Use if_changed rule for extracting cert from module signing key
Move certificate handling to its own directory
sign-file: Fix warning about BIO_reset() return value
PKCS#7: Add MODULE_LICENSE() to test module
Smack - Fix build error with bringup unconfigured
sign-file: Document dependency on OpenSSL devel libraries
PKCS#7: Appropriately restrict authenticated attributes and content type
KEYS: Add a name for PKEY_ID_PKCS7
PKCS#7: Improve and export the X.509 ASN.1 time object decoder
modsign: Use extract-cert to process CONFIG_SYSTEM_TRUSTED_KEYS
extract-cert: Cope with multiple X.509 certificates in a single file
sign-file: Generate CMS message as signature instead of PKCS#7
PKCS#7: Support CMS messages also [RFC5652]
X.509: Change recorded SKID & AKID to not include Subject or Issuer
PKCS#7: Check content type and versions
MAINTAINERS: The keyrings mailing list has moved
...
We cannot detect clang before including the arch Makefile, because that
can set the default cross compiler. We also cannot detect clang after
including the arch Makefile, because powerpc wants to know about clang.
Solve this by using an deferred variable. This costs us a few shell
invocations, but this is only a constant number.
Reported-by: Behan Webster <behanw@converseincode.com>
Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michal Marek <mmarek@suse.com>
Make sure 'make clean' removes *.su files generated by the gcc option
-fstack-usage.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Michal Marek <mmarek@suse.com>
Since commit 1329e8cc69 ("modsign: Extract signing cert from
CONFIG_MODULE_SIG_KEY if needed"), the build system has carefully coped
with the signing key being specified as a relative path in either the
source or or the build trees.
However, the actual signing of modules has not worked if the filename
is relative to the source tree.
Fix that by moving the config_filename helper into scripts/Kbuild.include
so that it can be used from elsewhere, and then using it in the top-level
Makefile to find the signing key file.
Kill the intermediate $(MODPUBKEY) and $(MODSECKEY) variables too, while
we're at it. There's no need for them.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Move certificate handling out of the kernel/ directory and into a certs/
directory to get all the weird stuff in one place and move the generated
signing keys into this directory.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: David Woodhouse <David.Woodhouse@intel.com>
The current rule for generating signing_key.priv and signing_key.x509 is
a classic example of a bad rule which has a tendency to break parallel
make. When invoked to create *either* target, it generates the other
target as a side-effect that make didn't predict.
So let's switch to using a single file signing_key.pem which contains
both key and certificate. That matches what we do in the case of an
external key specified by CONFIG_MODULE_SIG_KEY anyway, so it's also
slightly cleaner.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Move to using PKCS#7 messages as module signatures because:
(1) We have to be able to support the use of X.509 certificates that don't
have a subjKeyId set. We're currently relying on this to look up the
X.509 certificate in the trusted keyring list.
(2) PKCS#7 message signed information blocks have a field that supplies the
data required to match with the X.509 certificate that signed it.
(3) The PKCS#7 certificate carries fields that specify the digest algorithm
used to generate the signature in a standardised way and the X.509
certificates specify the public key algorithm in a standardised way - so
we don't need our own methods of specifying these.
(4) We now have PKCS#7 message support in the kernel for signed kexec purposes
and we can make use of this.
To make this work, the old sign-file script has been replaced with a program
that needs compiling in a previous patch. The rules to build it are added
here.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Vivek Goyal <vgoyal@redhat.com>
Pull kbuild fixes from Michal Marek:
"Two fixes for kbuild:
- The new ARCH_{CPP,A,C}FLAGS variables are reset before including
the arch Makefile
- Fix calling make modules_install twice when module compression is
enabled"
* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
Makefile: Force gzip and xz on module install
kbuild: Do not pick up ARCH_{CPP,A,C}FLAGS from the environment
Running `make modules_install` ordinarily will overwrite existing
modules. This is the desired behavior, and is how pretty much every
other `make install` target works.
However, if CONFIG_MODULE_COMPRESS is enabled, modules are passed
through gzip and xz which then do the file writing. Both gzip and xz
will error out if the file already exists, unless -f is passed.
This patch adds -f so that the behavior is uniform.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
Initialize the ARCH_* overrides before including the arch Makefile, to
avoid picking up the values from the environment. The variables can
still be overriden on the make command line, but this won't happen
by accident.
Signed-off-by: Michal Marek <mmarek@suse.com>
- Makefile changes (top-level+ARC) reinstates -O3 builds (regression since 3.16)
- IDU intc related fixes, IRQ affinity
- patch to make bitops safer for ARC
- perf fix from Alexey to remove signed PC braino
- Futex backend gets llock/scond support
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Merge tag 'arc-v4.2-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc
Pull ARC fixes from Vineet Gupta:
- Makefile changes (top-level+ARC) reinstates -O3 builds (regression
since 3.16)
- IDU intc related fixes, IRQ affinity
- patch to make bitops safer for ARC
- perf fix from Alexey to remove signed PC braino
- Futex backend gets llock/scond support
* tag 'arc-v4.2-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARCv2: support HS38 releases
ARC: make sure instruction_pointer() returns unsigned value
ARC: slightly refactor macros for boot logging
ARC: Add llock/scond to futex backend
arc:irqchip: prepare for drivers/irqchip/irqchip.h removal
ARC: Make ARC bitops "safer" (add anti-optimization)
ARCv2: [axs103] bump CPU frequency from 75 to 90 MHZ
ARCv2: intc: IDU: Fix potential race in installing a chained IRQ handler
ARCv2: intc: IDU: support irq affinity
ARC: fix unused var wanring
ARC: Don't memzero twice in dma_alloc_coherent for __GFP_ZERO
ARC: Override toplevel default -O2 with -O3
kbuild: Allow arch Makefiles to override {cpp,ld,c}flags
ARCv2: guard SLC DMA ops with spinlock
ARC: Kconfig: better way to disable ARC_HAS_LLSC for ARC_CPU_750D
Since commit a1c48bb1 (Makefile: Fix unrecognized cross-compiler command
line options), the arch Makefile is included earlier by the main
Makefile, preventing the arc architecture to set its -O3 compiler
option. Since there might be more use cases for an arch Makefile to
fine-tune the options, add support for ARCH_CPPFLAGS, ARCH_AFLAGS and
ARCH_CFLAGS variables that are appended to the respective kbuild
variables. The user still has the final say via the KCPPFLAGS, KAFLAGS
and KCFLAGS variables.
Reported-by: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Cc: stable@vger.kernel.org # 3.16+
Signed-off-by: Michal Marek <mmarek@suse.com>
Pull kbuild updates from Michal Marek:
"Just a few kbuild core commits this time:
- kallsyms fix for CONFIG_XIP_KERNEL
- bashisms in scripts/link-vmlinux.sh fixed
- workaround to make DEBUG_INFO_REDUCED more useful yet still space
efficient
- clang is not wrongly detected when cross-compiling"
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kbuild: include core debug info when DEBUG_INFO_REDUCED
scripts: link-vmlinux: Don't pass page offset to kallsyms if XIP Kernel
scripts: fix link-vmlinux.sh bash-ism
Makefile: Fix detection of clang when cross-compiling
Pull perf updates from Ingo Molnar:
"Kernel side changes mostly consist of work on x86 PMU drivers:
- x86 Intel PT (hardware CPU tracer) improvements (Alexander
Shishkin)
- x86 Intel CQM (cache quality monitoring) improvements (Thomas
Gleixner)
- x86 Intel PEBSv3 support (Peter Zijlstra)
- x86 Intel PEBS interrupt batching support for lower overhead
sampling (Zheng Yan, Kan Liang)
- x86 PMU scheduler fixes and improvements (Peter Zijlstra)
There's too many tooling improvements to list them all - here are a
few select highlights:
'perf bench':
- Introduce new 'perf bench futex' benchmark: 'wake-parallel', to
measure parallel waker threads generating contention for kernel
locks (hb->lock). (Davidlohr Bueso)
'perf top', 'perf report':
- Allow disabling/enabling events dynamicaly in 'perf top':
a 'perf top' session can instantly become a 'perf report'
one, i.e. going from dynamic analysis to a static one,
returning to a dynamic one is possible, to toogle the
modes, just press 'f' to 'freeze/unfreeze' the sampling. (Arnaldo Carvalho de Melo)
- Make Ctrl-C stop processing on TUI, allowing interrupting the load of big
perf.data files (Namhyung Kim)
'perf probe': (Masami Hiramatsu)
- Support glob wildcards for function name
- Support $params special probe argument: Collect all function arguments
- Make --line checks validate C-style function name.
- Add --no-inlines option to avoid searching inline functions
- Greatly speed up 'perf probe --list' by caching debuginfo.
- Improve --filter support for 'perf probe', allowing using its arguments
on other commands, as --add, --del, etc.
'perf sched':
- Add option in 'perf sched' to merge like comms to lat output (Josef Bacik)
Plus tons of infrastructure work - in particular preparation for
upcoming threaded perf report support, but also lots of other work -
and fixes and other improvements. See (much) more details in the
shortlog and in the git log"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (305 commits)
perf tools: Configurable per thread proc map processing time out
perf tools: Add time out to force stop proc map processing
perf report: Fix sort__sym_cmp to also compare end of symbol
perf hists browser: React to unassigned hotkey pressing
perf top: Tell the user how to unfreeze events after pressing 'f'
perf hists browser: Honour the help line provided by builtin-{top,report}.c
perf hists browser: Do not exit when 'f' is pressed in 'report' mode
perf top: Replace CTRL+z with 'f' as hotkey for enable/disable events
perf annotate: Rename source_line_percent to source_line_samples
perf annotate: Display total number of samples with --show-total-period
perf tools: Ensure thread-stack is flushed
perf top: Allow disabling/enabling events dynamicly
perf evlist: Add toggle_enable() method
perf trace: Fix race condition at the end of started workloads
perf probe: Speed up perf probe --list by caching debuginfo
perf probe: Show usage even if the last event is skipped
perf tools: Move libtraceevent dynamic list to separated LDFLAGS variable
perf tools: Fix a problem when opening old perf.data with different byte order
perf tools: Ignore .config-detected in .gitignore
perf probe: Fix to return error if no probe is added
...
User visible:
- Improve --filter support for 'perf probe', allowing using its arguments
on other commands, as --add, --del, etc (Masami Hiramatsu)
- Show warning when running 'perf kmem stat' on a unsuitable perf.data file,
i.e. one with events that are not the ones required for the stat variant
used (Namhyung Kim).
Infrastructure:
- Auxtrace support patches, paving the way to support Intel PT and BTS (Adrian Hunter)
- hists browser (top, report) refactorings (Namhyung Kim)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-core-for-mingo-3' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
User visible changes:
- Improve --filter support for 'perf probe', allowing using its arguments
on other commands, as --add, --del, etc (Masami Hiramatsu)
- Show warning when running 'perf kmem stat' on a unsuitable perf.data file,
i.e. one with events that are not the ones required for the stat variant
used (Namhyung Kim).
Infrastructure changes:
- Auxtrace support patches, paving the way to support Intel PT and BTS (Adrian Hunter)
- hists browser (top, report) refactorings (Namhyung Kim)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Several fixes were needed to allow following builds:
$ make tools/tmon
$ make -C <kernelsrc> tools/perf
$ make -C <kernelsrc>/tools perf
- some of the tools (perf) use same make variables as in
kernel build, unsetting srctree and objtree
- using original $(O) for O variable
- perf build does not follow the descend function setup
invoking it via it's own make rule
I tried the rest of the tools/Makefile targets and they
seem to work now.
Reported-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: linux-kbuild@vger.kernel.org
Link: http://lkml.kernel.org/r/1429389280-18720-3-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When the host's C compiler is clang, and when attempting to
cross-compile Linux e.g. to MIPS with mipsel-linux-gcc, the Makefile
would incorrectly detect the use of clang, which resulted in
clang-specific flags being passed to mipsel-linux-gcc.
This can be verified under Debian by installing the "clang" package,
and then using it as the default compiler with:
sudo update-alternatives --config cc
This patch moves the detection of clang after the $(CC) variable is
initialized to the name of the cross-compiler, so that the check applies
to the cross-compiler and not the host's C compiler.
v2: Move the detection of clang after the inclusion of the
arch/*/Makefile (as they might set $(CROSS_COMPILE))
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Pull kbuild updates from Michal Marek:
"Here is the first round of kbuild changes for v4.1-rc1:
- kallsyms fix for ARM and cleanup
- make dep(end) removed (developers have no sense of nostalgia these
days...)
- include Makefiles by relative path
- stop useless rebuilds of asm-offsets.h and bounds.h"
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
Kbuild: kallsyms: drop special handling of pre-3.0 GCC symbols
Kbuild: kallsyms: ignore veneers emitted by the ARM linker
kbuild: ia64: use $(src)/Makefile.gate rather than particular path
kbuild: include $(src)/Makefile rather than $(obj)/Makefile
kbuild: use relative path more to include Makefile
kbuild: use relative path to include Makefile
kbuild: do not add $(bounds-file) and $(offsets-file) to targets
kbuild: remove warning about "make depend"
kbuild: Don't reset timestamps in include/generated if not needed
Pull core locking changes from Ingo Molnar:
"Main changes:
- jump label asm preparatory work for PowerPC (Anton Blanchard)
- rwsem optimizations and cleanups (Davidlohr Bueso)
- mutex optimizations and cleanups (Jason Low)
- futex fix (Oleg Nesterov)
- remove broken atomicity checks from {READ,WRITE}_ONCE() (Peter
Zijlstra)"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
powerpc, jump_label: Include linux/jump_label.h to get HAVE_JUMP_LABEL define
jump_label: Allow jump labels to be used in assembly
jump_label: Allow asm/jump_label.h to be included in assembly
locking/mutex: Further simplify mutex_spin_on_owner()
locking: Remove atomicy checks from {READ,WRITE}_ONCE
locking/rtmutex: Rename argument in the rt_mutex_adjust_prio_chain() documentation as well
locking/rwsem: Fix lock optimistic spinning when owner is not running
locking: Remove ACCESS_ONCE() usage
locking/rwsem: Check for active lock before bailing on spinning
locking/rwsem: Avoid deceiving lock spinners
locking/rwsem: Set lock ownership ASAP
locking/rwsem: Document barrier need when waking tasks
locking/futex: Check PF_KTHREAD rather than !p->mm to filter out kthreads
locking/mutex: Refactor mutex_spin_on_owner()
locking/mutex: In mutex_spin_on_owner(), return true when owner changes
Prior to this commit, it was impossible to use relative path to
include Makefiles from the top level Makefile because the option
"--include-dir=$(srctree)" becomes effective when Make enters into
sub Makefiles.
To use relative path in any places, this commit moves the option
above the "sub-make" target.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Enough time has passed since "make depend" was deprecated.
Nobody would be in trouble without this hint.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
.. after extensive statistical analysis of my G+ polling, I've come to
the inescapable conclusion that internet polls are bad.
Big surprise.
But "Hurr durr I'ma sheep" trounced "I like online polls" by a 62-to-38%
margin, in a poll that people weren't even supposed to participate in.
Who can argue with solid numbers like that? 5,796 votes from people who
can't even follow the most basic directions?
In contrast, "v4.0" beat out "v3.20" by a slimmer margin of 56-to-44%,
but with a total of 29,110 votes right now.
Now, arguably, that vote spread is only about 3,200 votes, which is less
than the almost six thousand votes that the "please ignore" poll got, so
it could be considered noise.
But hey, I asked, so I'll honor the votes.
Pull kbuild updates from Michal Marek:
- several cleanups in kbuild
- serialize multiple *config targets so that 'make defconfig kvmconfig'
works
- The cc-ifversion macro got support for an else-branch
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kbuild,gcov: simplify kernel/gcov/Makefile more
kbuild: allow cc-ifversion to have the argument for false condition
kbuild,gcov: simplify kernel/gcov/Makefile
kbuild,gcov: remove unnecessary workaround
kbuild: do not add $(call ...) to invoke cc-version or cc-fullversion
kbuild: fix cc-ifversion macro
kbuild: drop $(version_h) from MRPROPER_FILES
kbuild: use mixed-targets when two or more config targets are given
kbuild: remove redundant line from bounds.h/asm-offsets.h
kbuild: merge bounds.h and asm-offsets.h rules
kbuild: Drop support for clean-rule
This provides the basic infrastructure to load kernel-specific python
helper scripts when debugging the kernel in gdb.
The loading mechanism is based on gdb loading for <objfile>-gdb.py when
opening <objfile>. Therefore, this places a corresponding link to the
main helper script into the output directory that contains vmlinux.
The main scripts will pull in submodules containing Linux specific gdb
commands and functions. To avoid polluting the source directory with
compiled python modules, we link to them from the object directory.
Due to gdb.parse_and_eval and string redirection for gdb.execute, we
depend on gdb >= 7.2.
This feature is enabled via CONFIG_GDB_SCRIPTS.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Michal Marek <mmarek@suse.cz> [kbuild stuff]
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kernel Address sanitizer (KASan) is a dynamic memory error detector. It
provides fast and comprehensive solution for finding use-after-free and
out-of-bounds bugs.
KASAN uses compile-time instrumentation for checking every memory access,
therefore GCC > v4.9.2 required. v4.9.2 almost works, but has issues with
putting symbol aliases into the wrong section, which breaks kasan
instrumentation of globals.
This patch only adds infrastructure for kernel address sanitizer. It's
not available for use yet. The idea and some code was borrowed from [1].
Basic idea:
The main idea of KASAN is to use shadow memory to record whether each byte
of memory is safe to access or not, and use compiler's instrumentation to
check the shadow memory on each memory access.
Address sanitizer uses 1/8 of the memory addressable in kernel for shadow
memory and uses direct mapping with a scale and offset to translate a
memory address to its corresponding shadow address.
Here is function to translate address to corresponding shadow address:
unsigned long kasan_mem_to_shadow(unsigned long addr)
{
return (addr >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET;
}
where KASAN_SHADOW_SCALE_SHIFT = 3.
So for every 8 bytes there is one corresponding byte of shadow memory.
The following encoding used for each shadow byte: 0 means that all 8 bytes
of the corresponding memory region are valid for access; k (1 <= k <= 7)
means that the first k bytes are valid for access, and other (8 - k) bytes
are not; Any negative value indicates that the entire 8-bytes are
inaccessible. Different negative values used to distinguish between
different kinds of inaccessible memory (redzones, freed memory) (see
mm/kasan/kasan.h).
To be able to detect accesses to bad memory we need a special compiler.
Such compiler inserts a specific function calls (__asan_load*(addr),
__asan_store*(addr)) before each memory access of size 1, 2, 4, 8 or 16.
These functions check whether memory region is valid to access or not by
checking corresponding shadow memory. If access is not valid an error
printed.
Historical background of the address sanitizer from Dmitry Vyukov:
"We've developed the set of tools, AddressSanitizer (Asan),
ThreadSanitizer and MemorySanitizer, for user space. We actively use
them for testing inside of Google (continuous testing, fuzzing,
running prod services). To date the tools have found more than 10'000
scary bugs in Chromium, Google internal codebase and various
open-source projects (Firefox, OpenSSL, gcc, clang, ffmpeg, MySQL and
lots of others): [2] [3] [4].
The tools are part of both gcc and clang compilers.
We have not yet done massive testing under the Kernel AddressSanitizer
(it's kind of chicken and egg problem, you need it to be upstream to
start applying it extensively). To date it has found about 50 bugs.
Bugs that we've found in upstream kernel are listed in [5].
We've also found ~20 bugs in out internal version of the kernel. Also
people from Samsung and Oracle have found some.
[...]
As others noted, the main feature of AddressSanitizer is its
performance due to inline compiler instrumentation and simple linear
shadow memory. User-space Asan has ~2x slowdown on computational
programs and ~2x memory consumption increase. Taking into account that
kernel usually consumes only small fraction of CPU and memory when
running real user-space programs, I would expect that kernel Asan will
have ~10-30% slowdown and similar memory consumption increase (when we
finish all tuning).
I agree that Asan can well replace kmemcheck. We have plans to start
working on Kernel MemorySanitizer that finds uses of unitialized
memory. Asan+Msan will provide feature-parity with kmemcheck. As
others noted, Asan will unlikely replace debug slab and pagealloc that
can be enabled at runtime. Asan uses compiler instrumentation, so even
if it is disabled, it still incurs visible overheads.
Asan technology is easily portable to other architectures. Compiler
instrumentation is fully portable. Runtime has some arch-dependent
parts like shadow mapping and atomic operation interception. They are
relatively easy to port."
Comparison with other debugging features:
========================================
KMEMCHECK:
- KASan can do almost everything that kmemcheck can. KASan uses
compile-time instrumentation, which makes it significantly faster than
kmemcheck. The only advantage of kmemcheck over KASan is detection of
uninitialized memory reads.
Some brief performance testing showed that kasan could be
x500-x600 times faster than kmemcheck:
$ netperf -l 30
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to localhost (127.0.0.1) port 0 AF_INET
Recv Send Send
Socket Socket Message Elapsed
Size Size Size Time Throughput
bytes bytes bytes secs. 10^6bits/sec
no debug: 87380 16384 16384 30.00 41624.72
kasan inline: 87380 16384 16384 30.00 12870.54
kasan outline: 87380 16384 16384 30.00 10586.39
kmemcheck: 87380 16384 16384 30.03 20.23
- Also kmemcheck couldn't work on several CPUs. It always sets
number of CPUs to 1. KASan doesn't have such limitation.
DEBUG_PAGEALLOC:
- KASan is slower than DEBUG_PAGEALLOC, but KASan works on sub-page
granularity level, so it able to find more bugs.
SLUB_DEBUG (poisoning, redzones):
- SLUB_DEBUG has lower overhead than KASan.
- SLUB_DEBUG in most cases are not able to detect bad reads,
KASan able to detect both reads and writes.
- In some cases (e.g. redzone overwritten) SLUB_DEBUG detect
bugs only on allocation/freeing of object. KASan catch
bugs right before it will happen, so we always know exact
place of first bad read/write.
[1] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel
[2] https://code.google.com/p/address-sanitizer/wiki/FoundBugs
[3] https://code.google.com/p/thread-sanitizer/wiki/FoundBugs
[4] https://code.google.com/p/memory-sanitizer/wiki/FoundBugs
[5] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel#Trophies
Based on work by Andrey Konovalov.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Acked-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull s390 updates from Martin Schwidefsky:
- The remaining patches for the z13 machine support: kernel build
option for z13, the cache synonym avoidance, SMT support,
compare-and-delay for spinloops and the CES5S crypto adapater.
- The ftrace support for function tracing with the gcc hotpatch option.
This touches common code Makefiles, Steven is ok with the changes.
- The hypfs file system gets an extension to access diagnose 0x0c data
in user space for performance analysis for Linux running under z/VM.
- The iucv hvc console gets wildcard spport for the user id filtering.
- The cacheinfo code is converted to use the generic infrastructure.
- Cleanup and bug fixes.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (42 commits)
s390/process: free vx save area when releasing tasks
s390/hypfs: Eliminate hypfs interval
s390/hypfs: Add diagnose 0c support
s390/cacheinfo: don't use smp_processor_id() in preemptible context
s390/zcrypt: fixed domain scanning problem (again)
s390/smp: increase maximum value of NR_CPUS to 512
s390/jump label: use different nop instruction
s390/jump label: add sanity checks
s390/mm: correct missing space when reporting user process faults
s390/dasd: cleanup profiling
s390/dasd: add locking for global_profile access
s390/ftrace: hotpatch support for function tracing
ftrace: let notrace function attribute disable hotpatching if necessary
ftrace: allow architectures to specify ftrace compile options
s390: reintroduce diag 44 calls for cpu_relax()
s390/zcrypt: Add support for new crypto express (CEX5S) adapter.
s390/zcrypt: Number of supported ap domains is not retrievable.
s390/spinlock: add compare-and-delay to lock wait loops
s390/tape: remove redundant if statement
s390/hvc_iucv: add simple wildcard matches to the iucv allow filter
...
If the kernel is compiled with function tracer support the -pg compile option
is passed to gcc to generate extra code into the prologue of each function.
This patch replaces the "open-coded" -pg compile flag with a CC_FLAGS_FTRACE
makefile variable which architectures can override if a different option
should be used for code generation.
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The introduction of the uapi directories in v3.7-rc1 moved some of the
generated headers from arch/*/include/generated to the uapi directory,
keeping the #include directives intact.
This creates a problem when bisecting, because the unversioned files are
not cleaned automatically by git and the compiler might include stale
headers as a result. Instead of cleaning them in the Makefiles, promote
arch/*/include/generated/uapi in the search path. Under normal
circumstances, there is no overlap between this uapi subdirectory and
its parent, so the include choices remain the same. We keep
arch/*/include/generated/uapi in the USERINCLUDE variable so that it is
usable standalone.
Note that we cannot completely swap the order of the uapi and
kernel-only directories, since the headers in include/uapi/asm-generic
are meant to be wrapped by their include/asm-generic counterparts when
building kernel code.
Reported-by: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Reported-by: David Drysdale <dmd@lurklurk.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now $(version_h) is include/generated/uapi/linux/version.h.
$(version_h) in MRPROPER_FILES is redundant because it is covered
by include/generated in MRPROPER_DIRS.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
"make kvmconfig" expects that the .config has already been created,
but some people might want to create the .config and run kvmconfig
in one shot command, like this:
$ make defconfig kvmconfig
To make sure this command works correctly even if -j* option is set,
we must handle them one by one.
This commit turns on mixed-targets when $(MAKECMDGOALS) includes
at least one config target and also includes another target.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Pull kbuild updates from Michal Marek:
"Here are the kbuild changes for v3.19-rc1:
- Cleanups and deduplication in the main Makefile and
scripts/Makefile.*
- Sort the output of *config targets in make help
- Old <linux/version.h> is always removed to avoid a surprise during
bisecting
- Warning fix in kconfig"
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kbuild: remove redundant -rR flag of hdr-inst
kbuild: Fix make help-<board series> on powerpc
kbuild: Automatically remove stale <linux/version.h> file
kconfig: Fix warning "‘jump’ may be used uninitialized"
Makefile: sort list of defconfig targets in make help output
kbuild: Remove duplicate $(cmd) definition in Makefile.clean
kbuild: collect shorthands into scripts/Kbuild.include
make ARCH=powerpc help-<board series> should not require a cofigured
source tree. Also, sort the boards in the output.
Signed-off-by: Michal Marek <mmarek@suse.cz>
In 3.7, the file moved from include/linux/ to
include/generated/uapi/linux/. The path in the #include directive
remained the same for compatibility reasons, but this created a problem
when bisecting. Commit 9c8cdb71 (kbuild: unconditionally clobber
include/linux/version.h on distclean) fixes this, provided the user does
make distclean between builds. Better not rely on the user and delete
the stale file each time make is invoked.
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Without sorting this list is completely unreadable for ARCH=arm.
Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
The shorthand "clean" is defined in both the top Makefile and
scripts/Makefile.clean. Likewise, the "hdr-inst" is defined in
both the top Makefile and scripts/Makefile.headersinst.
To reduce code duplication, this commit collects them into
scripts/Kbuild.include like the "build" and "modbuiltin" shorthands.
It requires scripts/Makefile.clean to include scripts/Kbuild.include,
but its impact on the performance of "make clean" should be
negligible.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Sasha Levin reports:
"gcc5 changes the default standard to c11, which makes kernel build
unhappy
Explicitly define the kernel standard to be gnu89 which should keep
everything working exactly like it was before gcc5"
There are multiple small issues with the new default, but the biggest
issue seems to be that the old - and very useful - GNU extension to
allow a cast in front of an initializer has gone away.
Patch updated by Kirill:
"I'm pretty sure all gcc versions you can build kernel with supports
-std=gnu89. cc-option is redunrant.
We also need to adjust HOSTCFLAGS otherwise allmodconfig fails for me"
Note by Andrew Pinski:
"Yes it was reported and both problems relating to this extension has
been added to gnu99 and gnu11. Though there are other issues with the
kernel dealing with extern inline have different semantics between
gnu89 and gnu99/11"
End result: we may be able to move up to a newer stdc model eventually,
but right now the newer models have some annoying deficiencies, so the
traditional "gnu89" model ends up being the preferred one.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Singed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds