Commit Graph

948892 Commits

Author SHA1 Message Date
Chenxi Mao
234e9d7a62 riscv: Select ARCH_SUPPORTS_ATOMIC_RMW by default
Select ARCH_SUPPORTS_ATOMIC_RMW by default to enable osqlocks.

Signed-off-by: Chenxi Mao <maochenxi@eswin.com>
[Palmer: commit text]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-29 15:23:27 -07:00
Linus Walleij
3f1f6981af drm: pl111: Credit where credit is due
This moves over some of the credit for the development of this
driver from the old fbdev driver that I used as reference when
getting this in place.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Russell King <linux@armlinux.org.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200609200446.153209-1-linus.walleij@linaro.org
2020-06-30 00:20:58 +02:00
Wei Yongjun
dbb988b4e7 clk: qcom: Fix return value check in apss_ipq6018_probe()
In case of error, the function dev_get_regmap() returns NULL pointer
not ERR_PTR(). The IS_ERR() test in the return value check should be
replaced with NULL test.

Fixes: 5e77b4ef1b ("clk: qcom: Add ipq6018 apss clock controller")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Link: https://lore.kernel.org/r/20200628023055.50608-1-weiyongjun1@huawei.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2020-06-29 14:15:34 -07:00
Jarkko Sakkinen
377ff83083 selftests: tpm: Use /bin/sh instead of /bin/bash
It's better to use /bin/sh instead of /bin/bash in order to run the tests
in the BusyBox shell.

Fixes: 6ea3dfe1e0 ("selftests: add TPM 2.0 tests")
Cc: stable@vger.kernel.org
Cc: linux-integrity@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-06-29 14:19:38 -06:00
Jarkko Sakkinen
88a16840f4 selftests: tpm: Use 'test -e' instead of 'test -f'
'test -f' is suitable only for *regular* files. Use 'test -e' instead.

Cc: Nikita Sobolev <Nikita.Sobolev@synopsys.com>
Cc: linux-integrity@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Fixes: 5627f9cffe ("Kernel selftests: Add check if TPM devices are supported")
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-06-29 14:19:23 -06:00
Jarkko Sakkinen
5be206eaac Revert "tpm: selftest: cleanup after unseal with wrong auth/policy test"
The reverted commit illegitly uses tpm2-tools. External dependencies are
absolutely forbidden from these tests. There is also the problem that
clearing is not necessarily wanted behavior if the test/target computer is
not used only solely for testing.

Fixes: a9920d3bad ("tpm: selftest: cleanup after unseal with wrong auth/policy test")
Cc: Tadeusz Struk <tadeusz.struk@intel.com>
Cc: stable@vger.kernel.org
Cc: linux-integrity@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-06-29 14:18:15 -06:00
Mark Brown
351cf7445f Merge branch 'for-5.8' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into asoc-5.9 2020-06-29 20:47:01 +01:00
Hans de Goede
3f31f7d9b5 ASoC: rt5670: Fix dac- and adc- vol-tlv values being off by a factor of 10
The adc_vol_tlv volume-control has a range from -17.625 dB to +30 dB,
not -176.25 dB to + 300 dB. This wrong scale is esp. a problem in userspace
apps which translate the dB scale to a linear scale. With the logarithmic
dB scale being of by a factor of 10 we loose all precision in the lower
area of the range when apps translate things to a linear scale.

E.g. the 0 dB default, which corresponds with a value of 47 of the
0 - 127 range for the control, would be shown as 0/100 in alsa-mixer.

Since the centi-dB values used in the TLV struct cannot represent the
0.375 dB step size used by these controls, change the TLV definition
for them to specify a min and max value instead of min + stepsize.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20200628155231.71089-5-hdegoede@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-06-29 20:37:21 +01:00
Hans de Goede
85ca6b17e2 ASoC: rt5670: Add new gpio1_is_ext_spk_en quirk and enable it on the Lenovo Miix 2 10
The Lenovo Miix 2 10 has a keyboard dock with extra speakers in the dock.
Rather then the ACL5672's GPIO1 pin being used as IRQ to the CPU, it is
actually used to enable the amplifier for these speakers
(the IRQ to the CPU comes directly from the jack-detect switch).

Add a quirk for having an ext speaker-amplifier enable pin on GPIO1
and replace the Lenovo Miix 2 10's dmi_system_id table entry's wrong
GPIO_DEV quirk (which needs to be renamed to GPIO1_IS_IRQ) with the
new RT5670_GPIO1_IS_EXT_SPK_EN quirk, so that we enable the external
speaker-amplifier as necessary.

Also update the ident field for the dmi_system_id table entry, the
Miix models are not Thinkpads.

Fixes: 67e03ff3f3 ("ASoC: codecs: rt5670: add Thinkpad Tablet 10 quirk")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1786723
Link: https://lore.kernel.org/r/20200628155231.71089-4-hdegoede@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-06-29 20:37:20 +01:00
Hans de Goede
5cacc6f576 ASoC: rt5670: Correct RT5670_LDO_SEL_MASK
The RT5670_PWR_ANLG1 register has 3 bits to select the LDO voltage,
so the correct mask is 0x7 not 0x3.

Because of this wrong mask we were programming the ldo bits
to a setting of binary 001 (0x05 & 0x03) instead of binary 101
when moving to SND_SOC_BIAS_PREPARE.

According to the datasheet 001 is a reserved value, so no idea
what it did, since the driver was working fine before I guess we
got lucky and it does something which is ok.

Fixes: 5e8351de74 ("ASoC: add RT5670 CODEC driver")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200628155231.71089-3-hdegoede@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-06-29 20:37:19 +01:00
Hans de Goede
0ceb8a36d0 ASoC: Intel: cht_bsw_rt5672: Change bus format to I2S 2 channel
The default mode for SSP configuration is TDM 4 slot and so far we were
using this for the bus format on cht-bsw-rt56732 boards.

One board, the Lenovo Miix 2 10 uses not 1 but 2 codecs connected to SSP2.
The second piggy-backed, output-only codec is inside the keyboard-dock
(which has extra speakers). Unlike the main rt5672 codec, we cannot
configure this codec, it is hard coded to use 2 channel 24 bit I2S.

Using 4 channel TDM leads to the dock speakers codec (which listens in on
the data send from the SSP to the rt5672 codec) emiting horribly distorted
sound.

Since we only support 2 channels anyways, there is no need for TDM on any
cht-bsw-rt5672 designs. So we can simply use I2S 2ch everywhere.

This commit fixes the Lenovo Miix 2 10 dock speakers issue by changing
the bus format set in cht_codec_fixup() to I2S 2 channel.

This change has been tested on the following devices with a rt5672 codec:

Lenovo Miix 2 10
Lenovo Thinkpad 8
Lenovo Thinkpad 10 (gen 1)

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Cc: stable@vger.kernel.org
BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1786723
Link: https://lore.kernel.org/r/20200628155231.71089-2-hdegoede@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-06-29 20:37:18 +01:00
Eric Biggers
3e20aa9630 block/keyslot-manager: use kvfree_sensitive()
Make blk_ksm_destroy() use the kvfree_sensitive() function (which was
introduced in v5.8-rc1) instead of open-coding it.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 13:24:05 -06:00
Akira Yokosawa
5ef0a07a79 Documentation/litmus-tests: Add note on herd7 7.56 in atomic litmus test
herdtools 7.56 has enhanced herd7's C parser so that the "(void)expr"
construct in Atomic-RMW-ops-are-atomic-WRT-atomic_set.litmus is
accepted.

This is independent of LKMM's cat model, so mention the required
version in the header of the litmus test and its entry in README.

CC: Boqun Feng <boqun.feng@gmail.com>
Reported-by: Andrea Parri <parri.andrea@gmail.com>
Acked-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:05:18 -07:00
Akira Yokosawa
2bfa5c62de tools/memory-model/README: Mention herdtools7 7.56 in compatibility table
herdtools7 7.56 is going to be released in the week of 22 Jun 2020.
This commit therefore adds the exact version in the compatibility table.

Acked-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:05:18 -07:00
Akira Yokosawa
d075a78a5a tools/memory-model/README: Expand dependency of klitmus7
klitmus7 is independent of the memory model but depends on the
build-target kernel release.
It occasionally lost compatibility due to kernel API changes [1, 2, 3].
It was remedied in a backwards-compatible manner respectively [4, 5, 6].

Reflect this fact in README.

[1]: b899a85043 ("compiler.h: Remove ACCESS_ONCE()")
[2]: 0bb95f80a3 ("Makefile: Globally enable VLA warning")
[3]: d56c0d45f0 ("proc: decouple proc from VFS with "struct proc_ops"")
[4]: https://github.com/herd/herdtools7/commit/e87d7f9287d1
     ("klitmus: Use WRITE_ONCE and READ_ONCE in place of deprecated ACCESS_ONCE")
[5]: https://github.com/herd/herdtools7/commit/a0cbb10d02be
     ("klitmus: Avoid variable length array")
[6]: https://github.com/herd/herdtools7/commit/46b9412d3a58
     ("klitmus: Linux kernel v5.6.x compat")

NOTE: [5] was ahead of herdtools7 7.53, which did not make an
official release.  Code generated by klitmus7 without [5] can still be
built targeting Linux 4.20--5.5 if you don't care VLA warnings.

Acked-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:05:18 -07:00
Joel Fernandes (Google)
c425fb5f8d Documentation/litmus-tests: Cite an RCU litmus test
This commit cites a pertinent RCU-related litmus test.

Co-developed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Co-developed-by: Akira Yokosawa <akiyks@gmail.com>
[Alan: grammar nit]
[ paulmck: Update commit log and title per Akira feedback. ]
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:05:18 -07:00
Akira Yokosawa
cdaac9d6d2 Documentation/litmus-tests: Merge atomic's README into top-level one
Where Documentation/litmus-tests/README lists RCU litmus tests,
Documentation/litmus-tests/atomic/README lists atomic litmus tests.
For symmetry, merge the latter into former, with some context
adjustment in the introduction.

Acked-by: Andrea Parri <parri.andrea@gmail.com>
Acked-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:05:18 -07:00
Akira Yokosawa
9725dd5551 tools/memory-model: Fix reference to litmus test in recipes.txt
The name of litmus test doesn't match the one described below.
Fix the name of litmus test.

Acked-by: Andrea Parri <parri.andrea@gmail.com>
Acked-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:05:18 -07:00
Boqun Feng
e30d023555 Documentation/litmus-tests/atomic: Add a test for smp_mb__after_atomic()
We already use a litmus test in atomic_t.txt to describe atomic RMW +
smp_mb__after_atomic() is stronger than acquire (both the read and the
write parts are ordered). So make it a litmus test in atomic-tests
directory, so that people can access the litmus easily.

Additionally, change the processor numbers "P1, P2" to "P0, P1" in
atomic_t.txt for the consistency with the processor numbers in the
litmus test, which herd can handle.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:05:18 -07:00
Boqun Feng
4dcd4d36dd Documentation/litmus-tests/atomic: Add a test for atomic_set()
We already use a litmus test in atomic_t.txt to describe the behavior of
an atomic_set() with the an atomic RMW, so add it into atomic-tests
directory to make it easily accessible for anyone who cares about the
semantics of our atomic APIs.

Besides currently the litmus test "atomic-set" in atomic_t.txt has a few
things to be improved:

1)	The CPU/Processor numbers "P1,P2" are not only inconsistent with
	the rest of the document, which uses "CPU0" and "CPU1", but also
	unacceptable by the herd tool, which requires processors start
	at "P0".

2)	The initialization block uses a "atomic_set()", which is OK, but
	it's better to use ATOMIC_INIT() to make clear this is an
	initialization.

3)	The return value of atomic_add_unless() is discarded
	inexplicitly, which is OK for C language, but it will be helpful
	to the herd tool if we use a void cast to make the discard
	explicit.

4)	The name and the paragraph describing the test need to be more
	accurate and aligned with our wording in LKMM.

Therefore fix these in both atomic_t.txt and the new added litmus test.

Acked-by: Andrea Parri <parri.andrea@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:05:18 -07:00
Boqun Feng
efff615020 Documentation/litmus-tests: Introduce atomic directory
Although we have atomic_t.txt and its friends to describe the semantics
of atomic APIs and lib/atomic64_test.c for build testing and testing in
UP mode, the tests for our atomic APIs in real SMP mode are still
missing. Since now we have the LKMM tool in kernel and litmus tests can
be used to generate kernel modules for testing purpose with "klitmus" (a
tool from the LKMM toolset), it makes sense to put a few typical litmus
tests into kernel so that

1)	they are the examples to describe the conceptual mode of the
	semantics of atomic APIs, and

2)	they can be used to generate kernel test modules for anyone
	who is interested to test the atomic APIs implementation (in
	most cases, is the one who implements the APIs for a new arch)

Therefore, introduce the atomic directory for this purpose. The
directory is maintained by the LKMM group to make sure the litmus tests
are always aligned with our memory model.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Andrea Parri <parri.andrea@gmail.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:05:18 -07:00
Boqun Feng
4a9cc65f7a tools/memory-model: Add an exception for limitations on _unless() family
According to Luc, atomic_add_unless() is directly provided by herd7,
therefore it can be used in litmus tests. So change the limitation
section in README to unlimit the use of atomic_add_unless().

Cc: Luc Maranget <luc.maranget@inria.fr>
Acked-by: Andrea Parri <parri.andrea@gmail.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:05:18 -07:00
Joel Fernandes (Google)
7f871338ff MAINTAINERS: Update maintainers for new Documentation/litmus-tests
This commit adds Joel Fernandes as official LKMM reviewer.

Acked-by: Boqun Feng <boqun.feng@gmail.com>
Acked-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
[ paulmck: Apply Joe Perches alphabetization feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:05:18 -07:00
Joel Fernandes (Google)
a591890c4e Documentation: LKMM: Add litmus test for RCU GP guarantee where reader stores
This adds an example for the important RCU grace period guarantee, which
shows an RCU reader can never span a grace period.

Acked-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:05:18 -07:00
Joel Fernandes (Google)
be4a37973c Documentation: LKMM: Add litmus test for RCU GP guarantee where updater frees object
This adds an example for the important RCU grace period guarantee, which
shows an RCU reader can never span a grace period.

Acked-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:05:17 -07:00
Marco Elver
c1b1460901 tools/memory-model: Fix "conflict" definition
The definition of "conflict" should not include the type of access nor
whether the accesses are concurrent or not, which this patch addresses.
The definition of "data race" remains unchanged.

The definition of "conflict" as we know it and is cited by various
papers on memory consistency models appeared in [1]: "Two accesses to
the same variable conflict if at least one is a write; two operations
conflict if they execute conflicting accesses."

The LKMM as well as the C11 memory model are adaptations of
data-race-free, which are based on the work in [2]. Necessarily, we need
both conflicting data operations (plain) and synchronization operations
(marked). For example, C11's definition is based on [3], which defines a
"data race" as: "Two memory operations conflict if they access the same
memory location, and at least one of them is a store, atomic store, or
atomic read-modify-write operation. In a sequentially consistent
execution, two memory operations from different threads form a type 1
data race if they conflict, at least one of them is a data operation,
and they are adjacent in <T (i.e., they may be executed concurrently)."

[1] D. Shasha, M. Snir, "Efficient and Correct Execution of Parallel
    Programs that Share Memory", 1988.
	URL: http://snir.cs.illinois.edu/listed/J21.pdf

[2] S. Adve, "Designing Memory Consistency Models for Shared-Memory
    Multiprocessors", 1993.
	URL: http://sadve.cs.illinois.edu/Publications/thesis.pdf

[3] H.-J. Boehm, S. Adve, "Foundations of the C++ Concurrency Memory
    Model", 2008.
	URL: https://www.hpl.hp.com/techreports/2008/HPL-2008-56.pdf

Signed-off-by: Marco Elver <elver@google.com>
Co-developed-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:05:17 -07:00
Paul E. McKenney
38908de90a tools/memory-model: Add recent references
This commit updates the list of LKMM-related publications in
Documentation/references.txt.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Andrea Parri <parri.andrea@gmail.com>
2020-06-29 12:05:17 -07:00
Marco Elver
61d56d7aa5 kcsan: Disable branch tracing in core runtime
Disable branch tracing in core KCSAN runtime if branches are being
traced (TRACE_BRANCH_PROFILING). This it to avoid its performance
impact, but also avoid recursion in case KCSAN is enabled for the branch
tracing runtime.

The latter had already been a problem for KASAN:
https://lore.kernel.org/lkml/CANpmjNOeXmD5E3O50Z3MjkiuCYaYOPyi+1rq=GZvEKwBvLR0Ug@mail.gmail.com/

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:04:48 -07:00
Marco Elver
2839a23207 kcsan: Simplify compiler flags
Simplify the set of compiler flags for the runtime by removing cc-option
from -fno-stack-protector, because all supported compilers support it.
This saves us one compiler invocation during build.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:04:48 -07:00
Marco Elver
e68dcd8eac kcsan: Re-add GCC as a supported compiler
GCC version 11 recently implemented all requirements to correctly
support KCSAN:

1. Correct no_sanitize-attribute inlining behaviour:
   https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=4089df8ef4a63126b0774c39b6638845244c20d2

2. --param=tsan-distinguish-volatile
   https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=ab2789ec507a94f1a75a6534bca51c7b39037ce0

3. --param=tsan-instrument-func-entry-exit
   https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=06712fc68dc9843d9af7c7ac10047f49d305ad76

Therefore, we can re-enable GCC for KCSAN, and document the new compiler
requirements.

Signed-off-by: Marco Elver <elver@google.com>
Cc: Martin Liska <mliska@suse.cz>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:04:48 -07:00
Marco Elver
56b031f0ab kcsan: Add jiffies test to test suite
Add a test that KCSAN nor the compiler gets confused about accesses to
jiffies on different architectures.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:04:48 -07:00
Marco Elver
7e766560e6 kcsan: Remove existing special atomic rules
Remove existing special atomic rules from kcsan_is_atomic_special()
because they are no longer needed. Since we rely on the compiler
emitting instrumentation distinguishing volatile accesses, the rules
have become redundant.

Let's keep kcsan_is_atomic_special() around, so that we have an obvious
place to add special rules should the need arise in future.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:04:48 -07:00
Marco Elver
acfa087ccf kcsan: Rename test.c to selftest.c
Rename 'test.c' to 'selftest.c' to better reflect its purpose (Kconfig
variable and code inside already match this). This is to avoid confusion
with the test suite module in 'kcsan-test.c'.

No functional change.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:04:48 -07:00
Marco Elver
9dd979bae4 kcsan: Silence -Wmissing-prototypes warning with W=1
The functions here should not be forward declared for explicit use
elsewhere in the kernel, as they should only be emitted by the compiler
due to sanitizer instrumentation.  Add forward declarations a line above
their definition to shut up warnings in W=1 builds.

Link: https://lkml.kernel.org/r/202006060103.jSCpnV1g%lkp@intel.com
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:04:48 -07:00
Marco Elver
2888557f68 kcsan: Prefer '__no_kcsan inline' in test
Instead of __no_kcsan_or_inline, prefer '__no_kcsan inline' in test --
this is in case we decide to remove __no_kcsan_or_inline.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:04:48 -07:00
Qian Cai
33190b675c locking/osq_lock: Annotate a data race in osq_lock
The prev->next pointer can be accessed concurrently as noticed by KCSAN:

 write (marked) to 0xffff9d3370dbbe40 of 8 bytes by task 3294 on cpu 107:
  osq_lock+0x25f/0x350
  osq_wait_next at kernel/locking/osq_lock.c:79
  (inlined by) osq_lock at kernel/locking/osq_lock.c:185
  rwsem_optimistic_spin
  <snip>

 read to 0xffff9d3370dbbe40 of 8 bytes by task 3398 on cpu 100:
  osq_lock+0x196/0x350
  osq_lock at kernel/locking/osq_lock.c:157
  rwsem_optimistic_spin
  <snip>

Since the write only stores NULL to prev->next and the read tests if
prev->next equals to this_cpu_ptr(&osq_node). Even if the value is
shattered, the code is still working correctly. Thus, mark it as an
intentional data race using the data_race() macro.

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:04:48 -07:00
Marco Elver
1fe84fd4a4 kcsan: Add test suite
This adds KCSAN test focusing on behaviour of the integrated runtime.
Tests various race scenarios, and verifies the reports generated to
console. Makes use of KUnit for test organization, and the Torture
framework for test thread control.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:04:48 -07:00
Paul E. McKenney
c93773c1a3 rculist: Add ASSERT_EXCLUSIVE_ACCESS() to __list_splice_init_rcu()
After the sync() in __list_splice_init_rcu(), there should be no
readers traversing the old list.  This commit therefore enlists the
help of KCSAN to verify this condition via a pair of calls to
ASSERT_EXCLUSIVE_ACCESS().

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Marco Elver <elver@google.com>
2020-06-29 12:04:48 -07:00
Qian Cai
cb38f82043 x86/mm/pat: Mark an intentional data race
cpa_4k_install could be accessed concurrently as noticed by KCSAN,

read to 0xffffffffaa59a000 of 8 bytes by interrupt on cpu 7:
cpa_inc_4k_install arch/x86/mm/pat/set_memory.c:131 [inline]
__change_page_attr+0x10cf/0x1840 arch/x86/mm/pat/set_memory.c:1514
__change_page_attr_set_clr+0xce/0x490 arch/x86/mm/pat/set_memory.c:1636
__set_pages_np+0xc4/0xf0 arch/x86/mm/pat/set_memory.c:2148
__kernel_map_pages+0xb0/0xc8 arch/x86/mm/pat/set_memory.c:2178
kernel_map_pages include/linux/mm.h:2719 [inline] <snip>

write to 0xffffffffaa59a000 of 8 bytes by task 1 on cpu 6:
cpa_inc_4k_install arch/x86/mm/pat/set_memory.c:131 [inline]
__change_page_attr+0x10ea/0x1840 arch/x86/mm/pat/set_memory.c:1514
__change_page_attr_set_clr+0xce/0x490 arch/x86/mm/pat/set_memory.c:1636
__set_pages_p+0xc4/0xf0 arch/x86/mm/pat/set_memory.c:2129
__kernel_map_pages+0x2e/0xc8 arch/x86/mm/pat/set_memory.c:2176
kernel_map_pages include/linux/mm.h:2719 [inline] <snip>

Both accesses are due to the same "cpa_4k_install++" in
cpa_inc_4k_install. A data race here could be potentially undesirable:
depending on compiler optimizations or how x86 executes a non-LOCK'd
increment, it may lose increments, corrupt the counter, etc. Since this
counter only seems to be used for printing some stats, this data race
itself is unlikely to cause harm to the system though. Thus, mark this
intentional data race using the data_race() marco.

Suggested-by: Macro Elver <elver@google.com>
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:04:47 -07:00
Qian Cai
cda099b37d fork: Annotate a data race in vm_area_dup()
struct vm_area_struct could be accessed concurrently as noticed by
KCSAN,

 write to 0xffff9cf8bba08ad8 of 8 bytes by task 14263 on cpu 35:
  vma_interval_tree_insert+0x101/0x150:
  rb_insert_augmented_cached at include/linux/rbtree_augmented.h:58
  (inlined by) vma_interval_tree_insert at mm/interval_tree.c:23
  __vma_link_file+0x6e/0xe0
  __vma_link_file at mm/mmap.c:629
  vma_link+0xa2/0x120
  mmap_region+0x753/0xb90
  do_mmap+0x45c/0x710
  vm_mmap_pgoff+0xc0/0x130
  ksys_mmap_pgoff+0x1d1/0x300
  __x64_sys_mmap+0x33/0x40
  do_syscall_64+0x91/0xc44
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 read to 0xffff9cf8bba08a80 of 200 bytes by task 14262 on cpu 122:
  vm_area_dup+0x6a/0xe0
  vm_area_dup at kernel/fork.c:362
  __split_vma+0x72/0x2a0
  __split_vma at mm/mmap.c:2661
  split_vma+0x5a/0x80
  mprotect_fixup+0x368/0x3f0
  do_mprotect_pkey+0x263/0x420
  __x64_sys_mprotect+0x51/0x70
  do_syscall_64+0x91/0xc44
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

vm_area_dup() blindly copies all fields of original VMA to the new one.
This includes coping vm_area_struct::shared.rb which is normally
protected by i_mmap_lock. But this is fine because the read value will
be overwritten on the following __vma_link_file() under proper
protection. Thus, mark it as an intentional data race and insert a few
assertions for the fields that should not be modified concurrently.

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:04:47 -07:00
Paul E. McKenney
13625c0a40 Merge branches 'doc.2020.06.29a', 'fixes.2020.06.29a', 'kfree_rcu.2020.06.29a', 'rcu-tasks.2020.06.29a', 'scale.2020.06.29a', 'srcu.2020.06.29a' and 'torture.2020.06.29a' into HEAD
doc.2020.06.29a:  Documentation updates.
fixes.2020.06.29a:  Miscellaneous fixes.
kfree_rcu.2020.06.29a:  kfree_rcu() updates.
rcu-tasks.2020.06.29a:  RCU Tasks updates.
scale.2020.06.29a:  Read-side scalability tests.
srcu.2020.06.29a:  SRCU updates.
torture.2020.06.29a:  Torture-test updates.
2020-06-29 12:03:15 -07:00
Paul E. McKenney
7a6bbeaa01 torture: Remove obsolete "cd $KVM"
In the dim distant past, qemu commands needed to be run from the
rcutorture directory, but this is no longer the case.  This commit
therefore removes the now-useless "cd $KVM" from the kvm-test-1-run.sh
script.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:01:45 -07:00
Paul E. McKenney
316db5897e torture: Avoid duplicate specification of qemu command
Currently, the qemu command is constructed twice, once to dump it
to the qemu-cmd file and again to execute it.  This is of course an
accident waiting to happen, but is done to ensure that the remainder
of the script has an accurate idea of the running qemu command's PID.
This commit therefore places both the qemu command and the PID capture
into a new temporary file and sources that temporary file.  Thus the
single construction of the qemu command into the qemu-cmd file suffices
for both purposes.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:01:45 -07:00
Paul E. McKenney
2102ad290a torture: Dump ftrace at shutdown only if requested
If there is a large number of torture tests running concurrently,
all of which are dumping large ftrace buffers at shutdown time, the
resulting dumping can take a very long time, particularly on systems
with rotating-rust storage.  This commit therefore adds a default-off
torture.ftrace_dump_at_shutdown module parameter that enables
shutdown-time ftrace-buffer dumping.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:01:45 -07:00
Paul E. McKenney
06efa9b4b2 torture: Add kvm-tranform.sh script for qemu-cmd files
This commit adds a script that transforms qemu-cmd files to allow them
and the corresponding kernels to be run in contexts other than the one
that they were created for, including on systems other than the one that
they were built on.  For example, this allows the build products from a
--buildonly run to be transformed to allow distributed rcutorture testing.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:01:45 -07:00
Paul E. McKenney
9ccba350bd torture: Add more tracing crib notes to kvm.sh
This commit adds a few more hints about how to use tracing as comments
at the end of kvm.sh.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:01:45 -07:00
Paul E. McKenney
61b77be09e torture: Improve diagnostic for KCSAN-incapable compilers
Using --kcsan when the compiler does not support KCSAN results in this:

:CONFIG_KCSAN=y: improperly set
:CONFIG_KCSAN_REPORT_ONCE_IN_MS=100000: improperly set
:CONFIG_KCSAN_VERBOSE=y: improperly set
:CONFIG_KCSAN_INTERRUPT_WATCHER=y: improperly set
Clean KCSAN run in /home/git/linux-rcu/tools/testing/selftests/rcutorture/res/2020.06.16-09.53.16

This is a bit obtuse, so this commit adds checks resulting in this:

:CONFIG_KCSAN=y: improperly set
:CONFIG_KCSAN_REPORT_ONCE_IN_MS=100000: improperly set
:CONFIG_KCSAN_VERBOSE=y: improperly set
:CONFIG_KCSAN_INTERRUPT_WATCHER=y: improperly set
Compiler or architecture does not support KCSAN!
Did you forget to switch your compiler with --kmake-arg CC=<cc-that-supports-kcsan>?

Suggested-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Marco Elver <elver@google.com>
2020-06-29 12:01:45 -07:00
Paul E. McKenney
6bcaf2a087 torture: Correctly summarize build-only runs
Currently, kvm-recheck.sh complains that qemu failed for --buildonly
runs, which is sort of true given that qemu can hardly succeed if not
invoked in the first place.  Nevertheless, this commit swaps the order
of checks in kvm-recheck.sh so that --buildonly runs will be summarized
more straightforwardly.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:01:44 -07:00
Marco Elver
603d11ad69 torture: Pass --kmake-arg to all make invocations
We need to pass the arguments provided to --kmake-arg to all make
invocations. In particular, the make invocations generating the configs
need to see the final make arguments, e.g. if config variables depend on
particular variables that are passed to make.

For example, when using '--kcsan --kmake-arg CC=clang-11', we would lose
CONFIG_KCSAN=y due to 'make oldconfig' not seeing that we want to use a
compiler that supports KCSAN.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:01:44 -07:00
Paul E. McKenney
7752275118 rcutorture: Check for unwatched readers
RCU is supposed to be watching all non-idle kernel code and also all
softirq handlers.  This commit adds some teeth to this statement by
adding a WARN_ON_ONCE().

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:01:44 -07:00