30 Oct, 2020
1 commit
-
The files under Documentation/ABI should follow the syntax
as defined at Documentation/ABI/README.Allow checking if they're following the syntax by running
the ABI parser script on COMPILE_TEST.With that, when there's a problem with a file under
Documentation/ABI, it would produce a warning like:Warning: file ./Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats#14:
What '/sys/bus/pci/devices//aer_stats/aer_rootport_total_err_cor' doesn't have a description
Warning: file ./Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats#21:
What '/sys/bus/pci/devices//aer_stats/aer_rootport_total_err_fatal' doesn't have a descriptionAcked-by: Jonathan Corbet
Signed-off-by: Mauro Carvalho Chehab
Link: https://lore.kernel.org/r/57a38de85cb4b548857207cf1fc1bf1ee08613c9.1604042072.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman
23 Oct, 2020
1 commit
-
Pull Kbuild updates from Masahiro Yamada:
- Support 'make compile_commands.json' to generate the compilation
database more easily, avoiding stale entries- Support 'make clang-analyzer' and 'make clang-tidy' for static checks
using clang-tidy- Preprocess scripts/modules.lds.S to allow CONFIG options in the
module linker script- Drop cc-option tests from compiler flags supported by our minimal
GCC/Clang versions- Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y
- Use sha1 build id for both BFD linker and LLD
- Improve deb-pkg for reproducible builds and rootless builds
- Remove stale, useless scripts/namespace.pl
- Turn -Wreturn-type warning into error
- Fix build error of deb-pkg when CONFIG_MODULES=n
- Replace 'hostname' command with more portable 'uname -n'
- Various Makefile cleanups
* tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits)
kbuild: Use uname for LINUX_COMPILE_HOST detection
kbuild: Only add -fno-var-tracking-assignments for old GCC versions
kbuild: remove leftover comment for filechk utility
treewide: remove DISABLE_LTO
kbuild: deb-pkg: clean up package name variables
kbuild: deb-pkg: do not build linux-headers package if CONFIG_MODULES=n
kbuild: enforce -Werror=return-type
scripts: remove namespace.pl
builddeb: Add support for all required debian/rules targets
builddeb: Enable rootless builds
builddeb: Pass -n to gzip for reproducible packages
kbuild: split the build log of kallsyms
kbuild: explicitly specify the build id style
scripts/setlocalversion: make git describe output more reliable
kbuild: remove cc-option test of -Werror=date-time
kbuild: remove cc-option test of -fno-stack-check
kbuild: remove cc-option test of -fno-strict-overflow
kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles
kbuild: remove redundant CONFIG_KASAN check from scripts/Makefile.kasan
kbuild: do not create built-in objects for external module builds
...
19 Oct, 2020
2 commits
-
…/kernel/git/shuah/linux-kselftest
Pull more Kunit updates from Shuah Khan:
- add Kunit to kernel_init() and remove KUnit from init calls entirely.
This addresses the concern that Kunit would not work correctly during
late init phase.- add a linker section where KUnit can put references to its test
suites.This is the first step in transitioning to dispatching all KUnit
tests from a centralized executor rather than having each as its own
separate late_initcall.- add a centralized executor to dispatch tests rather than relying on
late_initcall to schedule each test suite separately. Centralized
execution is for built-in tests only; modules will execute tests when
loaded.- convert bitfield test to use KUnit framework
- Documentation updates for naming guidelines and how
kunit_test_suite() works.- add test plan to KUnit TAP format
* tag 'linux-kselftest-kunit-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
lib: kunit: Fix compilation test when using TEST_BIT_FIELD_COMPILE
lib: kunit: add bitfield test conversion to KUnit
Documentation: kunit: add a brief blurb about kunit_test_suite
kunit: test: add test plan to KUnit TAP format
init: main: add KUnit to kernel init
kunit: test: create a single centralized executor for all tests
vmlinux.lds.h: add linker section for KUnit test suites
Documentation: kunit: Add naming guidelines -
Pull RCU changes from Ingo Molnar:
- Debugging for smp_call_function()
- RT raw/non-raw lock ordering fixes
- Strict grace periods for KASAN
- New smp_call_function() torture test
- Torture-test updates
- Documentation updates
- Miscellaneous fixes
[ This doesn't actually pull the tag - I've dropped the last merge from
the RCU branch due to questions about the series. - Linus ]* tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (77 commits)
smp: Make symbol 'csd_bug_count' static
kernel/smp: Provide CSD lock timeout diagnostics
smp: Add source and destination CPUs to __call_single_data
rcu: Shrink each possible cpu krcp
rcu/segcblist: Prevent useless GP start if no CBs to accelerate
torture: Add gdb support
rcutorture: Allow pointer leaks to test diagnostic code
rcutorture: Hoist OOM registry up one level
refperf: Avoid null pointer dereference when buf fails to allocate
rcutorture: Properly synchronize with OOM notifier
rcutorture: Properly set rcu_fwds for OOM handling
torture: Add kvm.sh --help and update help message
rcutorture: Add CONFIG_PROVE_RCU_LIST to TREE05
torture: Update initrd documentation
rcutorture: Replace HTTP links with HTTPS ones
locktorture: Make function torture_percpu_rwsem_init() static
torture: document --allcpus argument added to the kvm.sh script
rcutorture: Output number of elapsed grace periods
rcutorture: Remove KCSAN stubs
rcu: Remove unused "cpu" parameter from rcu_report_qs_rdp()
...
17 Oct, 2020
1 commit
-
Patch series "add fault injection to user memory access", v3.
The goal of this series is to improve testing of fault-tolerance in usages
of user memory access functions, by adding support for fault injection.syzkaller/syzbot are using the existing fault injection modes and will use
this particular feature also.The first patch adds failure injection capability for usercopy functions.
The second changes usercopy functions to use this new failure capability
(copy_from_user, ...). The third patch adds get/put/clear_user failures
to x86.This patch (of 3):
Add a failure injection capability to improve testing of fault-tolerance
in usages of user memory access functions.Add CONFIG_FAULT_INJECTION_USERCOPY to enable faults in usercopy
functions. The should_fail_usercopy function is to be called by these
functions (copy_from_user, get_user, ...) in order to fail or not.Signed-off-by: Albert van der Linde
Signed-off-by: Andrew Morton
Reviewed-by: Akinobu Mita
Reviewed-by: Alexander Potapenko
Cc: Borislav Petkov
Cc: Ingo Molnar
Cc: Jonathan Corbet
Cc: Thomas Gleixner
Cc: Arnd Bergmann
Cc: Peter Zijlstra (Intel)
Cc: "H. Peter Anvin"
Cc: Al Viro
Cc: Andrey Konovalov
Cc: Dmitry Vyukov
Cc: Marco Elver
Cc: Christoph Hellwig
Link: http://lkml.kernel.org/r/20200831171733.955393-1-alinde@google.com
Link: http://lkml.kernel.org/r/20200831171733.955393-2-alinde@google.com
Signed-off-by: Linus Torvalds
14 Oct, 2020
2 commits
-
Here is a very rare race which leaks memory:
Page P0 is allocated to the page cache. Page P1 is free.
Thread A Thread B Thread C
find_get_entry():
xas_load() returns P0
Removes P0 from page cache
P0 finds its buddy P1
alloc_pages(GFP_KERNEL, 1) returns P0
P0 has refcount 1
page_cache_get_speculative(P0)
P0 has refcount 2
__free_pages(P0)
P0 has refcount 1
put_page(P0)
P1 is not freedFix this by freeing all the pages in __free_pages() that won't be freed
by the call to put_page(). It's usually not a good idea to split a page,
but this is a very unlikely scenario.Fixes: e286781d5f2e ("mm: speculative page references")
Signed-off-by: Matthew Wilcox (Oracle)
Signed-off-by: Andrew Morton
Acked-by: Mike Rapoport
Cc: Nick Piggin
Cc: Hugh Dickins
Cc: Peter Zijlstra
Link: https://lkml.kernel.org/r/20200926213919.26642-1-willy@infradead.org
Signed-off-by: Linus Torvalds -
This adds the conversion of the runtime tests of test_bitfield,
from `lib/test_bitfield.c` to KUnit tests.Code Style Documentation: [0]
Signed-off-by: Vitor Massaru Iha
Link: [0] https://lore.kernel.org/linux-kselftest/20200620054944.167330-1-davidgow@google.com/T/#u
Reviewed-by: Brendan Higgins
Signed-off-by: Shuah Khan
09 Oct, 2020
1 commit
-
…k/linux-rcu into core/rcu
Pull v5.10 RCU changes from Paul E. McKenney:
- Debugging for smp_call_function().
- Strict grace periods for KASAN. The point of this series is to find
RCU-usage bugs, so the corresponding new RCU_STRICT_GRACE_PERIOD
Kconfig option depends on both DEBUG_KERNEL and RCU_EXPERT, and is
further disabled by dfefault. Finally, the help text includes
a goodly list of scary caveats.- New smp_call_function() torture test.
- Torture-test updates.
- Documentation updates.
- Miscellaneous fixes.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
20 Sep, 2020
1 commit
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This moves the KCSAN kconfig items under menu 'Generic Kernel Debugging
Instruments' where UBSAN resides.Signed-off-by: Changbin Du
Signed-off-by: Andrew Morton
Tested-by: Randy Dunlap
Reviewed-by: Randy Dunlap
Cc: Greg Kroah-Hartman
Cc: Marco Elver
Link: https://lkml.kernel.org/r/20200904152224.5570-1-changbin.du@gmail.com
Signed-off-by: Linus Torvalds
05 Sep, 2020
2 commits
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csd.2020.09.04a: CPU smp_call_function() torture tests.
-
This commit causes csd_lock_wait() to emit diagnostics when a CPU
fails to respond quickly enough to one of the smp_call_function()
family of function calls. These diagnostics are enabled by a new
CSD_LOCK_WAIT_DEBUG Kconfig option that depends on DEBUG_KERNEL.This commit was inspired by an earlier patch by Josef Bacik.
[ paulmck: Fix for syzbot+0f719294463916a3fc0e@syzkaller.appspotmail.com ]
[ paulmck: Fix KASAN use-after-free issue reported by Qian Cai. ]
[ paulmck: Fix botched nr_cpu_ids comparison per Dan Carpenter. ]
[ paulmck: Apply Peter Zijlstra feedback. ]
Link: https://lore.kernel.org/lkml/00000000000042f21905a991ecea@google.com
Link: https://lore.kernel.org/lkml/0000000000002ef21705a9933cf3@google.com
Cc: Peter Zijlstra
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: Sebastian Andrzej Siewior
Signed-off-by: Paul E. McKenney
26 Aug, 2020
1 commit
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While playing with [1] I saw that the handling
of CONFIG_DEBUG_INFO can be simplified.[1] https://patchwork.kernel.org/patch/11716107/
Signed-off-by: Sedat Dilek
Signed-off-by: Masahiro Yamada
25 Aug, 2020
1 commit
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This commit adds an smp_call_function() torture test that repeatedly
invokes this function and complains if things go badly awry.Signed-off-by: Paul E. McKenney
13 Aug, 2020
5 commits
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There exists duplicated "the" in the help text of CONFIG_PANIC_TIMEOUT,
Remove it.Signed-off-by: Tiezhu Yang
Signed-off-by: Andrew Morton
Reviewed-by: Kees Cook
Cc: Xuefeng Li
Link: http://lkml.kernel.org/r/1591103358-32087-2-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Linus Torvalds -
Add tests of GENMASK and GENMASK_ULL.
A few test cases that should fail compilation are provided under #ifdef
TEST_GENMASK_FAILURES[rd.dunlap@gmail.com: add MODULE_LICENSE()]
Link: http://lkml.kernel.org/r/dfc74524-0789-2827-4eff-476ddab65699@gmail.com
[weiyongjun1@huawei.com: make some functions static]
Link: http://lkml.kernel.org/r/20200702150336.4756-1-weiyongjun1@huawei.comSuggested-by: Andy Shevchenko
Signed-off-by: Rikard Falkeborn
Signed-off-by: Randy Dunlap
Signed-off-by: Wei Yongjun
Signed-off-by: Andrew Morton
Reviewed-by: Andy Shevchenko
Acked-by: William Breathitt Gray
Cc: Emil Velikov
Cc: Syed Nayyar Waris
Cc: Andy Shevchenko
Cc: Arnd Bergmann
Cc: Geert Uytterhoeven
Cc: Kees Cook
Cc: Linus Walleij
Cc: Masahiro Yamada
Link: http://lkml.kernel.org/r/20200621054210.14804-2-rikard.falkeborn@gmail.com
Link: http://lkml.kernel.org/r/20200608221823.35799-2-rikard.falkeborn@gmail.com
Signed-off-by: Linus Torvalds -
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.Signed-off-by: Alexander A. Klimov
Signed-off-by: Andrew Morton
Acked-by: Coly Li [crc64.c]
Link: http://lkml.kernel.org/r/20200726112154.16510-1-grandmaster@al2klimov.de
Signed-off-by: Linus Torvalds -
Since test_lockup is a test module to generate lockups, it is better to
limit TEST_LOCKUP to module (=m) or disabled (=n) because we can not use
the module parameters when CONFIG_TEST_LOCKUP=y.Signed-off-by: Tiezhu Yang
Signed-off-by: Andrew Morton
Reviewed-by: Guenter Roeck
Cc: Konstantin Khlebnikov
Cc: Kees Cook
Link: http://lkml.kernel.org/r/1595555407-29875-1-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Linus Torvalds -
Recently 0day reported many strange performance changes (regression or
improvement), in which there was no obvious relation between the culprit
commit and the benchmark at the first look, and it causes people to doubt
the test itself is wrong.Upon further check, many of these cases are caused by the change to the
alignment of kernel text or data, as whole text/data of kernel are linked
together, change in one domain may affect alignments of other domains.gcc has an option '-falign-functions=n' to force text aligned, and with
that option enabled, some of those performance changes will be gone, like
[1][2][3].Add this option so that developers and 0day can easily find performance
bump caused by text alignment change, as tracking these strange bump is
quite time consuming. Though it can't help in other cases like data
alignment changes like [4].Following is some size data for v5.7 kernel built with a RHEL config used
in 0day:text data bss dec filename
19738771 13292906 5554236 38585913 vmlinux.noalign
19758591 13297002 5529660 38585253 vmlinux.align32Raw vmlinux size in bytes:
v5.7 v5.7+align32
253950832 254018000 +0.02%Some benchmark data, most of them have no big change:
* hackbench: [ -1.8%, +0.5%]
* fsmark: [ -3.2%, +3.4%] # ext4/xfs/btrfs
* kbuild: [ -2.0%, +0.9%]
* will-it-scale: [ -0.5%, +1.8%] # mmap1/pagefault3
* netperf:
- TCP_CRR [+16.6%, +97.4%]
- TCP_RR [-18.5%, -1.8%]
- TCP_STREAM [ -1.1%, +1.9%][1] https://lore.kernel.org/lkml/20200114085637.GA29297@shao2-debian/
[2] https://lore.kernel.org/lkml/20200330011254.GA14393@feng-iot/
[3] https://lore.kernel.org/lkml/1d98d1f0-fe84-6df7-f5bd-f4cb2cdb7f45@intel.com/
[4] https://lore.kernel.org/lkml/20200205123216.GO12867@shao2-debian/Signed-off-by: Feng Tang
Signed-off-by: Andrew Morton
Cc: Masahiro Yamada
Cc: Michal Marek
Cc: Andi Kleen
Cc: Huang Ying
Cc: Andy Shevchenko
Link: http://lkml.kernel.org/r/1595475001-90945-1-git-send-email-feng.tang@intel.com
Signed-off-by: Linus Torvalds
06 Aug, 2020
1 commit
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Pull driver core updates from Greg KH:
"Here is the "big" set of changes to the driver core, and some drivers
using the changes, for 5.9-rc1."Biggest" thing in here is the device link exposure in sysfs, to help
to tame the madness that is SoC device tree representations and driver
interactions with it.Other stuff in here that is interesting is:
- device probe log helper so that drivers can report problems in a
unified way easier.- devres functions added
- DEVICE_ATTR_ADMIN_* macro added to make it harder to write
incorrect sysfs file permissions- documentation cleanups
- ability for debugfs to be present in the kernel, yet not exposed to
userspace. Needed for systems that want it enabled, but do not
trust users, so they can still use some kernel functions that were
otherwise disabled.- other minor fixes and cleanups
The patches outside of drivers/base/ all have acks from the respective
subsystem maintainers to go through this tree instead of theirs.All of these have been in linux-next with no reported issues"
* tag 'driver-core-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (39 commits)
drm/bridge: lvds-codec: simplify error handling
drm/bridge/sii8620: fix resource acquisition error handling
driver core: add deferring probe reason to devices_deferred property
driver core: add device probe log helper
driver core: Avoid binding drivers to dead devices
Revert "test_firmware: Test platform fw loading on non-EFI systems"
firmware_loader: EFI firmware loader must handle pre-allocated buffer
selftest/firmware: Add selftest timeout in settings
test_firmware: Test platform fw loading on non-EFI systems
driver core: Change delimiter in devlink device's name to "--"
debugfs: Add access restriction option
tracefs: Remove unnecessary debug_fs checks.
driver core: Fix probe_count imbalance in really_probe()
kobject: remove unused KOBJ_MAX action
driver core: Fix sleeping in invalid context during device link deletion
driver core: Add waiting_for_supplier sysfs file for devices
driver core: Add state_synced sysfs file for devices that support it
driver core: Expose device link details in sysfs
driver core: Drop mention of obsolete bus rwsem from kernel-doc
debugfs: file: Remove unnecessary cast in kfree()
...
04 Aug, 2020
1 commit
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Pull x86 FPU selftest from Ingo Molnar:
"Add the /sys/kernel/debug/selftest_helpers/test_fpu FPU self-test"* tag 'x86-fpu-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
selftests/fpu: Add an FPU selftest
03 Aug, 2020
1 commit
-
Signed-off-by: Ingo Molnar
29 Jul, 2020
1 commit
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Asserting that preemption is enabled or disabled is a critical sanity
check. Developers are usually reluctant to add such a check in a
fastpath as reading the preemption count can be costly.Extend the lockdep API with macros asserting that preemption is disabled
or enabled. If lockdep is disabled, or if the underlying architecture
does not support kernel preemption, this assert has no runtime overhead.References: f54bb2ec02c8 ("locking/lockdep: Add IRQs disabled/enabled assertion APIs: ...")
Signed-off-by: Ahmed S. Darwish
Signed-off-by: Peter Zijlstra (Intel)
Link: https://lkml.kernel.org/r/20200720155530.1173732-8-a.darwish@linutronix.de
27 Jul, 2020
1 commit
-
Prior to commit:
859d069ee1dd ("lockdep: Prepare for NMI IRQ state tracking")
IRQ state tracking was disabled in NMIs due to nmi_enter()
doing lockdep_off() -- with the obvious requirement that NMI entry
call nmi_enter() before trace_hardirqs_off().[ AFAICT, PowerPC and SH violate this order on their NMI entry ]
However, that commit explicitly changed lockdep_hardirqs_*() to ignore
lockdep_off() and breaks every architecture that has irq-tracing in
it's NMI entry that hasn't been fixed up (x86 being the only fixed one
at this point).The reason for this change is that by ignoring lockdep_off() we can:
- get rid of 'current->lockdep_recursion' in lockdep_assert_irqs*()
which was going to to give header-recursion issues with the
seqlock rework.- allow these lockdep_assert_*() macros to function in NMI context.
Restore the previous state of things and allow an architecture to
opt-in to the NMI IRQ tracking support, however instead of relying on
lockdep_off(), rely on in_nmi(), both are part of nmi_enter() and so
over-all entry ordering doesn't need to change.Signed-off-by: Peter Zijlstra (Intel)
Signed-off-by: Ingo Molnar
Link: https://lore.kernel.org/r/20200727124852.GK119549@hirez.programming.kicks-ass.net
23 Jul, 2020
1 commit
-
Since debugfs include sensitive information it need to be treated
carefully. But it also has many very useful debug functions for userspace.
With this option we can have same configuration for system with
need of debugfs and a way to turn it off. This gives a extra protection
for exposure on systems where user-space services with system
access are attacked.It is controlled by a configurable default value that can be override
with a kernel command line parameter. (debugfs=)It can be on or off, but also internally on but not seen from user-space.
This no-mount mode do not register a debugfs as filesystem, but client can
register their parts in the internal structures. This data can be readed
with a debugger or saved with a crashkernel. When it is off clients
get EPERM error when accessing the functions for registering their
components.Signed-off-by: Peter Enderborg
Link: https://lore.kernel.org/r/20200716071511.26864-3-peter.enderborg@sony.com
Signed-off-by: Greg Kroah-Hartman
03 Jul, 2020
1 commit
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There is no extra interrupt when registering a shared interrupt handler
since 2011. Update the Kconfig text to make it clear and to avoid wrong
assumptions when debugging issues found by it.Fixes: 6d83f94db95c ("genirq: Disable the SHIRQ_DEBUG call in request_threaded_irq for now")
Link: https://lore.kernel.org/linux-i2c/859e8211-2c56-8dd5-d6fb-33e4358e4128@pengutronix.de/T/#mf24d7070d7e0c8f17b6be6ceb51df94b7d7613b3
Reviewed-by: Krzysztof Kozlowski
Acked-by: Andy Shevchenko
Signed-off-by: Wolfram Sang
Link: https://lore.kernel.org/r/20200702222024.6915-1-wsa+renesas@sang-engineering.com
Signed-off-by: Greg Kroah-Hartman
29 Jun, 2020
1 commit
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Add a selftest for the usage of FPU code in kernel mode.
Currently only implemented for x86. In the future, kernel FPU testing
could be unified between the different architectures supporting it.[ bp:
- Split out from a conglomerate patch, put comments over statements.
- run the test only on debugfs write.
- Add bare-minimum run_test_fpu.sh, run 1000 iterations on all CPUs
by default.
- Add conditionally -msse2 so that clang doesn't generate library
calls.
- Use cc-option to detect gcc 7.1 not supporting -mpreferred-stack-boundary=3 (amluto).
- Document stuff so that we don't forget.
- Fix:
ld: lib/test_fpu.o: in function `test_fpu_get':
>> test_fpu.c:(.text+0x16e): undefined reference to `__sanitizer_cov_trace_cmpd'
>> ld: test_fpu.c:(.text+0x1a7): undefined reference to `__sanitizer_cov_trace_cmpd'
ld: test_fpu.c:(.text+0x1e0): undefined reference to `__sanitizer_cov_trace_cmpd'
]Reported-by: kernel test robot
Signed-off-by: Petteri Aimonen
Signed-off-by: Borislav Petkov
Reviewed-by: Nick Desaulniers
Link: https://lkml.kernel.org/r/20200624114646.28953-3-bp@alien8.de
17 Jun, 2020
1 commit
-
cc-option and as-option are almost the same; both pass the flag to
$(CC). The main difference is the cc-option stops before the assemble
stage (-S option) whereas as-option stops after (-c option).I chose -S because it is slightly faster, but $(cc-option,-gz=zlib)
returns a wrong result (https://lkml.org/lkml/2020/6/9/1529).
It has been fixed by commit 7b16994437c7 ("Makefile: Improve compressed
debug info support detection"), but the assembler should always be
invoked for more reliable compiler option tests.However, you cannot simply replace -S with -c because the following
code in lib/Kconfig.debug would break:depends on $(cc-option,-gsplit-dwarf)
The combination of -c and -gsplit-dwarf does not accept /dev/null as
output.$ cat /dev/null | gcc -gsplit-dwarf -S -x c - -o /dev/null
$ echo $?
0$ cat /dev/null | gcc -gsplit-dwarf -c -x c - -o /dev/null
objcopy: Warning: '/dev/null' is not an ordinary file
$ echo $?
1$ cat /dev/null | gcc -gsplit-dwarf -c -x c - -o tmp.o
$ echo $?
0There is another flag that creates an separate file based on the
object file path:$ cat /dev/null | gcc -ftest-coverage -c -x c - -o /dev/null
:1: error: cannot open /dev/null.gcnoSo, we cannot use /dev/null to sink the output.
Align the cc-option implementation with scripts/Kbuild.include.
With -c option used in cc-option, as-option is unneeded.
Signed-off-by: Masahiro Yamada
Acked-by: Will Deacon
15 Jun, 2020
1 commit
-
Commit
10e68b02c861 ("Makefile: support compressed debug info")
added support for compressed debug sections.Support is detected by checking
- does the compiler support -gz=zlib
- does the assembler support --compressed-debug-sections=zlib
- does the linker support --compressed-debug-sections=zlibHowever, the gcc driver's support for this option is somewhat
convoluted. The driver's builtin specs are set based on the version of
binutils that it was configured with. It reports an error if the
configure-time linker/assembler (i.e., not necessarily the actual
assembler that will be run) do not support the option, but only if the
assembler (or linker) is actually invoked when -gz=zlib is passed.The cc-option check in scripts/Kconfig.include does not invoke the
assembler, so the gcc driver reports success even if it does not support
the option being passed to the assembler.Because the as-option check passes the option directly to the assembler
via -Wa,--compressed-debug-sections=zlib, the gcc driver does not see
this option and will never report an error.Combined with an installed version of binutils that is more recent than
the one the compiler was built with, it is possible for all three tests
to succeed, yet an actual compilation with -gz=zlib to fail.Moreover, it is unnecessary to explicitly pass
--compressed-debug-sections=zlib to the assembler via -Wa, since the
driver will do that automatically when it supports -gz=zlib.Convert the as-option to just -gz=zlib, simplifying it as well as
performing a better test of the gcc driver's capabilities.Reported-by: kernel test robot
Signed-off-by: Arvind Sankar
Reviewed-by: Nick Desaulniers
Signed-off-by: Masahiro Yamada
14 Jun, 2020
2 commits
-
Pull more Kbuild updates from Masahiro Yamada:
- fix build rules in binderfs sample
- fix build errors when Kbuild recurses to the top Makefile
- covert '---help---' in Kconfig to 'help'
* tag 'kbuild-v5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
treewide: replace '---help---' in Kconfig files with 'help'
kbuild: fix broken builds because of GZIP,BZIP2,LZOP variables
samples: binderfs: really compile this sample and fix build issues -
Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.There are a variety of indentation styles found.
a) 4 spaces + '---help---'
b) 7 spaces + '---help---'
c) 8 spaces + '---help---'
d) 1 space + 1 tab + '---help---'
e) 1 tab + '---help---' (correct indentation)
f) 1 tab + 1 space + '---help---'
g) 1 tab + 2 spaces + '---help---'In order to convert all of them to 1 tab + 'help', I ran the
following commend:$ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'
Signed-off-by: Masahiro Yamada
12 Jun, 2020
2 commits
-
Pull the Kernel Concurrency Sanitizer from Thomas Gleixner:
"The Kernel Concurrency Sanitizer (KCSAN) is a dynamic race detector,
which relies on compile-time instrumentation, and uses a
watchpoint-based sampling approach to detect races.The feature was under development for quite some time and has already
found legitimate bugs.Unfortunately it comes with a limitation, which was only understood
late in the development cycle:It requires an up to date CLANG-11 compiler
CLANG-11 is not yet released (scheduled for June), but it's the only
compiler today which handles the kernel requirements and especially
the annotations of functions to exclude them from KCSAN
instrumentation correctly.These annotations really need to work so that low level entry code and
especially int3 text poke handling can be completely isolated.A detailed discussion of the requirements and compiler issues can be
found here:https://lore.kernel.org/lkml/CANpmjNMTsY_8241bS7=XAfqvZHFLrVEkv_uM4aDUWE_kh3Rvbw@mail.gmail.com/
We came to the conclusion that trying to work around compiler
limitations and bugs again would end up in a major trainwreck, so
requiring a working compiler seemed to be the best choice.For Continous Integration purposes the compiler restriction is
manageable and that's where most xxSAN reports come from.For a change this limitation might make GCC people actually look at
their bugs. Some issues with CSAN in GCC are 7 years old and one has
been 'fixed' 3 years ago with a half baken solution which 'solved' the
reported issue but not the underlying problem.The KCSAN developers also ponder to use a GCC plugin to become
independent, but that's not something which will show up in a few
days.Blocking KCSAN until wide spread compiler support is available is not
a really good alternative because the continuous growth of lockless
optimizations in the kernel demands proper tooling support"* tag 'locking-kcsan-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (76 commits)
compiler_types.h, kasan: Use __SANITIZE_ADDRESS__ instead of CONFIG_KASAN to decide inlining
compiler.h: Move function attributes to compiler_types.h
compiler.h: Avoid nested statement expression in data_race()
compiler.h: Remove data_race() and unnecessary checks from {READ,WRITE}_ONCE()
kcsan: Update Documentation to change supported compilers
kcsan: Remove 'noinline' from __no_kcsan_or_inline
kcsan: Pass option tsan-instrument-read-before-write to Clang
kcsan: Support distinguishing volatile accesses
kcsan: Restrict supported compilers
kcsan: Avoid inserting __tsan_func_entry/exit if possible
ubsan, kcsan: Don't combine sanitizer with kcov on clang
objtool, kcsan: Add kcsan_disable_current() and kcsan_enable_current_nowarn()
kcsan: Add __kcsan_{enable,disable}_current() variants
checkpatch: Warn about data_race() without comment
kcsan: Use GFP_ATOMIC under spin lock
Improve KCSAN documentation a bit
kcsan: Make reporting aware of KCSAN tests
kcsan: Fix function matching in report
kcsan: Change data_race() to no longer require marking racing accesses
kcsan: Move kcsan_{disable,enable}_current() to kcsan-checks.h
... -
Merge the state of the locking kcsan branch before the read/write_once()
and the atomics modifications got merged.Squash the fallout of the rebase on top of the read/write once and atomic
fallback work into the merge. The history of the original branch is
preserved in tag locking-kcsan-2020-06-02.Signed-off-by: Thomas Gleixner
11 Jun, 2020
1 commit
-
Add some tests for get_count_order/long in test_bitops.c.
[akpm@linux-foundation.org: define local `i']
[akpm@linux-foundation.org: enhancement, warning fix, cleanup per Geert]
[akpm@linux-foundation.org: fix loop bound, per Wei Yang]Signed-off-by: Wei Yang
Signed-off-by: Andrew Morton
Reviewed-by: Andy Shevchenko
Cc: Christian Brauner
Cc: Geert Uytterhoeven
Link: http://lkml.kernel.org/r/20200602223728.32722-1-richard.weiyang@gmail.com
Signed-off-by: Linus Torvalds
10 Jun, 2020
1 commit
-
…kernel/git/shuah/linux-kselftest
Pull Kunit updates from Shuah Khan:
"This consists of:- Several config fragment fixes from Anders Roxell to improve test
coverage.- Improvements to kunit run script to use defconfig as default and
restructure the code for config/build/exec/parse from Vitor Massaru
Iha and David Gow.- Miscellaneous documentation warn fix"
* tag 'linux-kselftest-kunit-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
security: apparmor: default KUNIT_* fragments to KUNIT_ALL_TESTS
fs: ext4: default KUNIT_* fragments to KUNIT_ALL_TESTS
drivers: base: default KUNIT_* fragments to KUNIT_ALL_TESTS
lib: Kconfig.debug: default KUNIT_* fragments to KUNIT_ALL_TESTS
kunit: default KUNIT_* fragments to KUNIT_ALL_TESTS
kunit: Kconfig: enable a KUNIT_ALL_TESTS fragment
kunit: Fix TabError, remove defconfig code and handle when there is no kunitconfig
kunit: use KUnit defconfig by default
kunit: use --build_dir=.kunit as default
Documentation: test.h - fix warnings
kunit: kunit_tool: Separate out config/build/exec/parse
09 Jun, 2020
1 commit
-
Instead of enabling dynamic debug globally with CONFIG_DYNAMIC_DEBUG,
CONFIG_DYNAMIC_DEBUG_CORE will only enable core function of dynamic
debug. With the DYNAMIC_DEBUG_MODULE defined for any modules, dynamic
debug will be tied to them.This is useful for people who only want to enable dynamic debug for
kernel modules without worrying about kernel image size and memory
consumption is increasing too much.[orson.zhai@unisoc.com: v2]
Link: http://lkml.kernel.org/r/1587408228-10861-1-git-send-email-orson.unisoc@gmail.comSigned-off-by: Orson Zhai
Signed-off-by: Andrew Morton
Acked-by: Greg Kroah-Hartman
Acked-by: Petr Mladek
Cc: Jonathan Corbet
Cc: Sergey Senozhatsky
Cc: Steven Rostedt
Cc: Jason Baron
Cc: Randy Dunlap
Link: http://lkml.kernel.org/r/1586521984-5890-1-git-send-email-orson.unisoc@gmail.com
Signed-off-by: Linus Torvalds
07 Jun, 2020
1 commit
-
Pull Kbuild updates from Masahiro Yamada:
- fix warnings in 'make clean' for ARCH=um, hexagon, h8300, unicore32
- ensure to rebuild all objects when the compiler is upgraded
- exclude system headers from dependency tracking and fixdep processing
- fix potential bit-size mismatch between the kernel and BPF user-mode
helper- add the new syntax 'userprogs' to build user-space programs for the
target architecture (the same arch as the kernel)- compile user-space sample code under samples/ for the target arch
instead of the host arch- make headers_install fail if a CONFIG option is leaked to user-space
- sanitize the output format of scripts/checkstack.pl
- handle ARM 'push' instruction in scripts/checkstack.pl
- error out before modpost if a module name conflict is found
- error out when multiple directories are passed to M= because this
feature is broken for a long time- add CONFIG_DEBUG_INFO_COMPRESSED to support compressed debug info
- a lot of cleanups of modpost
- dump vmlinux symbols out into vmlinux.symvers, and reuse it in the
second pass of modpost- do not run the second pass of modpost if nothing in modules is
updated- install modules.builtin(.modinfo) by 'make install' as well as by
'make modules_install' because it is useful even when
CONFIG_MODULES=n- add new command line variables, GZIP, BZIP2, LZOP, LZMA, LZ4, and XZ
to allow users to use alternatives such as pigz, pbzip2, etc.* tag 'kbuild-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (96 commits)
kbuild: add variables for compression tools
Makefile: install modules.builtin even if CONFIG_MODULES=n
mksysmap: Fix the mismatch of '.L' symbols in System.map
kbuild: doc: rename LDFLAGS to KBUILD_LDFLAGS
modpost: change elf_info->size to size_t
modpost: remove is_vmlinux() helper
modpost: strip .o from modname before calling new_module()
modpost: set have_vmlinux in new_module()
modpost: remove mod->skip struct member
modpost: add mod->is_vmlinux struct member
modpost: remove is_vmlinux() call in check_for_{gpl_usage,unused}()
modpost: remove mod->is_dot_o struct member
modpost: move -d option in scripts/Makefile.modpost
modpost: remove -s option
modpost: remove get_next_text() and make {grab,release_}file static
modpost: use read_text_file() and get_line() for reading text files
modpost: avoid false-positive file open error
modpost: fix potential mmap'ed file overrun in get_src_version()
modpost: add read_text_file() and get_line() helpers
modpost: do not call get_modinfo() for vmlinux(.o)
...
05 Jun, 2020
3 commits
-
Test some bit clears/sets to make sure assembly doesn't change, and that
the set_bit and clear_bit functions work and don't cause sparse warnings.Instruct Kbuild to build this file with extra warning level -Wextra, to
catch new issues, and also doesn't hurt to build with C=1.This was used to test changes to arch/x86/include/asm/bitops.h.
In particular, sparse (C=1) was very concerned when the last bit before a
natural boundary, like 7, or 31, was being tested, as this causes sign
extension (0xffffff7f) for instance when clearing bit 7.Recommended usage:
make defconfig
scripts/config -m CONFIG_TEST_BITOPS
make modules_prepare
make C=1 W=1 lib/test_bitops.ko
objdump -S -d lib/test_bitops.ko
insmod lib/test_bitops.ko
rmmod lib/test_bitops.ko, there should be no compiler/sparse warnings and no
error messages in log.Link: http://lkml.kernel.org/r/20200310221747.2848474-2-jesse.brandeburg@intel.com
Signed-off-by: Jesse Brandeburg
Reviewed-by: Andy Shevchenko
Cc: Thomas Gleixner
CcL Ingo Molnar
Signed-off-by: Andrew Morton
Cc: Borislav Petkov
Cc: Rasmus Villemoes
Cc: Dan Williams
Cc: Peter Zijlstra
Cc: Wei Yang
Cc: Christian Brauner
Signed-off-by: Linus Torvalds -
This adds tests which will validate architecture page table helpers and
other accessors in their compliance with expected generic MM semantics.
This will help various architectures in validating changes to existing
page table helpers or addition of new ones.This test covers basic page table entry transformations including but not
limited to old, young, dirty, clean, write, write protect etc at various
level along with populating intermediate entries with next page table page
and validating them.Test page table pages are allocated from system memory with required size
and alignments. The mapped pfns at page table levels are derived from a
real pfn representing a valid kernel text symbol. This test gets called
via late_initcall().This test gets built and run when CONFIG_DEBUG_VM_PGTABLE is selected.
Any architecture, which is willing to subscribe this test will need to
select ARCH_HAS_DEBUG_VM_PGTABLE. For now this is limited to arc, arm64,
x86, s390 and powerpc platforms where the test is known to build and run
successfully Going forward, other architectures too can subscribe the test
after fixing any build or runtime problems with their page table helpers.Folks interested in making sure that a given platform's page table helpers
conform to expected generic MM semantics should enable the above config
which will just trigger this test during boot. Any non conformity here
will be reported as an warning which would need to be fixed. This test
will help catch any changes to the agreed upon semantics expected from
generic MM and enable platforms to accommodate it thereafter.[anshuman.khandual@arm.com: v17]
Link: http://lkml.kernel.org/r/1587436495-22033-3-git-send-email-anshuman.khandual@arm.com
[anshuman.khandual@arm.com: v18]
Link: http://lkml.kernel.org/r/1588564865-31160-3-git-send-email-anshuman.khandual@arm.com
Suggested-by: Catalin Marinas
Signed-off-by: Anshuman Khandual
Signed-off-by: Christophe Leroy
Signed-off-by: Qian Cai
Signed-off-by: Andrew Morton
Tested-by: Gerald Schaefer [s390]
Tested-by: Christophe Leroy [ppc32]
Reviewed-by: Ingo Molnar
Cc: Mike Rapoport
Cc: Vineet Gupta
Cc: Catalin Marinas
Cc: Will Deacon
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: Michael Ellerman
Cc: Heiko Carstens
Cc: Vasily Gorbik
Cc: Christian Borntraeger
Cc: Thomas Gleixner
Cc: Ingo Molnar
Cc: Borislav Petkov
Cc: "H. Peter Anvin"
Cc: Kirill A. Shutemov
Cc: Paul Walmsley
Cc: Palmer Dabbelt
Link: http://lkml.kernel.org/r/1583919272-24178-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Linus Torvalds -
This change extends kcov remote coverage support to allow collecting
coverage from soft interrupts in addition to kernel background threads.To collect coverage from code that is executed in softirq context, a part
of that code has to be annotated with kcov_remote_start/stop() in a
similar way as how it is done for global kernel background threads. Then
the handle used for the annotations has to be passed to the
KCOV_REMOTE_ENABLE ioctl.Internally this patch adjusts the __sanitizer_cov_trace_pc() compiler
inserted callback to not bail out when called from softirq context.
kcov_remote_start/stop() are updated to save/restore the current per task
kcov state in a per-cpu area (in case the softirq came when the kernel was
already collecting coverage in task context). Coverage from softirqs is
collected into pre-allocated per-cpu areas, whose size is controlled by
the new CONFIG_KCOV_IRQ_AREA_SIZE.[andreyknvl@google.com: turn current->kcov_softirq into unsigned int to fix objtool warning]
Link: http://lkml.kernel.org/r/841c778aa3849c5cb8c3761f56b87ce653a88671.1585233617.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov
Signed-off-by: Andrew Morton
Reviewed-by: Dmitry Vyukov
Cc: Alan Stern
Cc: Alexander Potapenko
Cc: Andrey Konovalov
Cc: Greg Kroah-Hartman
Cc: Marco Elver
Link: http://lkml.kernel.org/r/469bd385c431d050bc38a593296eff4baae50666.1584655448.git.andreyknvl@google.com
Signed-off-by: Linus Torvalds
03 Jun, 2020
1 commit
-
Pull hmm updates from Jason Gunthorpe:
"This series adds a selftest for hmm_range_fault() and several of the
DEVICE_PRIVATE migration related actions, and another simplification
for hmm_range_fault()'s API.- Simplify hmm_range_fault() with a simpler return code, no
HMM_PFN_SPECIAL, and no customizable output PFN format- Add a selftest for hmm_range_fault() and DEVICE_PRIVATE related
functionality"* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
MAINTAINERS: add HMM selftests
mm/hmm/test: add selftests for HMM
mm/hmm/test: add selftest driver for HMM
mm/hmm: remove the customizable pfn format from hmm_range_fault
mm/hmm: remove HMM_PFN_SPECIAL
drm/amdgpu: remove dead code after hmm_range_fault()
mm/hmm: make hmm_range_fault return 0 or -1