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932,869 commits

Author SHA1 Message Date
Beniamin Bia
4bb2b8f94a iio: adc: ad7476: implement devm_add_action_or_reset
Use devm_add_action_or_reset to automatically disable the device
when it is removed or an error occurs during probe routine.

Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-03-21 10:28:08 +00:00
Dragos Bogdan
0267a31666 iio: adc: ad7476: Add AD7091 support
AD7091R is already supported by this driver. While AD7091R allows the
choice of an internal or an external voltage reference, for AD7091 the
reference is only provided by VDD. Since this information is anyway
obtained through the "vcc" regulator, no other driver changes are
required for adding AD7091 support as well.

Signed-off-by: Dragos Bogdan <dragos.bogdan@analog.com>
Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-03-21 10:27:53 +00:00
Dragos Bogdan
3a6af93dd6 iio: adc: ad7476: Add IIO_CHAN_INFO_RAW for AD7091R
When CONVST signal is generated internally, IIO_CHAN_INFO_RAW can be
made available for AD7091R for single reads. This patch enables it and
makes supporting more devices by this driver easier.

Signed-off-by: Dragos Bogdan <dragos.bogdan@analog.com>
Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-03-21 10:27:45 +00:00
Dragos Bogdan
af37e4703d iio: adc: ad7476: Generate CONVST signal internally
Compared to the other supported parts, AD7091R are dependent of
a CONVST signal that initiates the conversion. At this moment, only
sampling in buffered mode is supported for AD7091R and the only
option until now was to generate this signal externally using an
IIO trigger. This patch adds the option of generating it internally,
more compatible triggers being available in this case.

Also, it is an intermediate step of adding support more devices.

Signed-off-by: Dragos Bogdan <dragos.bogdan@analog.com>
Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-03-21 10:27:36 +00:00
Andy Shevchenko
4be590e3f6 iio: adc: intel_mrfld_adc: Use be16_to_cpu() instead of get_unaligned_be16()
There is no need to call unaligned helpers on stack placed variables
because compiler will align them correctly, accordingly to architectural
ABI. Moreover, using bitwise type makes it explicit to see what we are
reading in bulk transfer. On top of that, use sizeof() instead of
magic value.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-03-21 10:27:23 +00:00
Andy Shevchenko
144eb562be iio: humidity: hts221: Drop unneeded casting when print error code
Explicit casting in printf() usually shows that something is not okay.
Here, we really don't need it by providing correct specifier.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-03-21 10:27:15 +00:00
Andy Shevchenko
92c3e93b7d iio: humidity: hts221: Make use of device properties
Device property API allows to gather device resources from different sources,
such as ACPI. Convert the drivers to unleash the power of device property API.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-03-21 10:27:05 +00:00
Andy Shevchenko
4d8d2f09ad iio: humidity: hts221: Use dev_get_platdata() to get platform_data
Use dev_get_platdata() to get the platform_data instead of
referencing it directly.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-03-21 10:26:54 +00:00
Andy Shevchenko
38bc80154a iio: st_sensors: Join string literals back
For easy grepping on debug purposes join string literals back in
the messages.

No functional change.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-03-21 10:26:43 +00:00
Andy Shevchenko
7da08588b9 iio: st_sensors: Drop unneeded casting when print error code
Explicit casting in printf() usually shows that something is not okay.
Here, we really don't need it by providing correct specifier.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-03-21 10:26:32 +00:00
Andy Shevchenko
1f38527d58 iio: st_sensors: Drop unneeded explicit castings
In few places the unnecessary explicit castings are being used.
Drop them for good.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-03-21 10:26:21 +00:00
Andy Shevchenko
49f20fc6fe iio: st_sensors: Use dev_get_platdata() to get platform_data
Use dev_get_platdata() to get the platform_data instead of
referencing it directly.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-03-21 10:26:10 +00:00
Andy Shevchenko
3c50dee995 iio: light: st_uvis25: Drop unneeded casting when print error code
Explicit casting in printf() usually shows that something is not okay.
Here, we really don't need it by providing correct specifier.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-03-21 10:25:59 +00:00
Takashi Iwai
35a4eeb055 iio: core: Use scnprintf() for avoiding potential buffer overflow
Since snprintf() returns the would-be-output size instead of the
actual output size, the succeeding calls may go beyond the given
buffer limit.  Fix it by replacing with scnprintf().

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-03-21 10:25:45 +00:00
Lars-Peter Clausen
2dbbe4d513 iio: xilinx-xadc: Fix typo in author's name
It appears the author of the xilinx-xadc driver can't even spell his own
name correctly. Fix that.

Reported-by: Lars Möllendorf <lars.moellendorf@plating.de>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-03-21 10:25:35 +00:00
Oscar Carter
3017e587e3 staging: vt6656: Use BIT() macro in vnt_mac_reg_bits_* functions
The last parameter in the functions vnt_mac_reg_bits_on and
vnt_mac_reg_bits_off defines the bits to set or unset. So, it's more
clear to use the BIT() macro instead of an hexadecimal value.

Signed-off-by: Oscar Carter <oscar.carter@gmx.com>
Link: https://lore.kernel.org/r/20200320181326.12156-1-oscar.carter@gmx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-21 11:03:16 +01:00
Michael Straube
609ccb3071 staging: rtl8188eu: remove some 5 GHz code
According to the TODO code valid only for 5 GHz should be removed.

- find and remove remaining code valid only for 5 GHz. Most of the obvious
  ones have been removed, but things like channel > 14 still exist.

Remove if statement that checks for channel > 14 from rtw_ieee80211.c.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20200320191305.10425-1-straube.linux@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-21 10:58:19 +01:00
Oscar Carter
a74081b442 staging: vt6656: Use BIT() macro instead of hex value
Use the BIT() macro instead of the hexadecimal value to define the
different bits in registers.

Signed-off-by: Oscar Carter <oscar.carter@gmx.com>
Link: https://lore.kernel.org/r/20200320171056.7841-1-oscar.carter@gmx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-21 10:58:16 +01:00
Heyi Guo
b2cb11f4f7 irqchip/gic-v4: Use Inner-Shareable attributes for virtual pending tables
There is no special reason to set virtual LPI pending table as
non-shareable. If we choose to hard code the shareability without
probing, Inner-Shareable is likely to be a better choice, as the
VPEs can move around and benefit from having the redistributors
snooping each other's cache, if that's something they can do.

Furthermore, Hisilicon hip08 ends up with unspecified errors when
mixing shareability attributes. So let's move to IS attributes for
the VPT. This has also been tested on D05 and didn't show any
regression.

Signed-off-by: Heyi Guo <guoheyi@huawei.com>
[maz: rewrote commit message]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20191130073849.38378-1-guoheyi@huawei.com
2020-03-21 09:40:47 +00:00
R Veera Kumar
067be57238 staging: rtl8723bs: os_dep: Remove whitespace characters in code line
Remove four leading whitespace characters in code line.

Signed-off-by: R Veera Kumar <vkor@vkten.in>
Link: https://lore.kernel.org/r/27b60d20868203efdc5975803f5f9d43e46526dd.1584764104.git.vkor@vkten.in
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-21 10:36:13 +01:00
R Veera Kumar
b6b2a53cf3 staging: rtl8723bs: os_dep: Correct long line comments
Correct long line comments to respect 80 character per
line limit.

Signed-off-by: R Veera Kumar <vkor@vkten.in>
Link: https://lore.kernel.org/r/16399fc057c6dd1c78e77ddd3b3224f4b2e37da5.1584764104.git.vkor@vkten.in
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-21 10:36:12 +01:00
R Veera Kumar
3056483111 staging: rtl8723bs: os_dep: Remove commented out code lines
Remove multiple commented out code lines.
Remove blank lines next to them.

Signed-off-by: R Veera Kumar <vkor@vkten.in>
Link: https://lore.kernel.org/r/a62d2fbb77990210b939a5ec99ee27cfa5749a09.1584764104.git.vkor@vkten.in
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-21 10:36:12 +01:00
Payal Kshirsagar
25e1543b9f staging: rtl8723bs: remove unneeded variables
Remove unneeded temporary local variables and their declarations.

Signed-off-by: Payal Kshirsagar <payalskshirsagar1234@gmail.com>
Link: https://lore.kernel.org/r/20200321074757.8321-1-payalskshirsagar1234@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-21 10:34:48 +01:00
Sergio Paracuellos
6bdf0ddd73 staging: mt7621-pci: delete release gpios related code
Making gpio8 and gpio9 vendor specific and putting them
into the specific dts file makes not needed to release
gpios anymore because we are not occupying those pins
in the first place if it is not necessary. When the
device tree is parsed we can also check and return for
the error because we rely in the fact that the related
device for the board is correct.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20200321072650.7784-3-sergio.paracuellos@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-21 10:31:55 +01:00
Sergio Paracuellos
0d326e722d staging: mt7621-dts: gpio 8 and 9 are vendor specific
There are three pins that can be used for reset gpios.
As mentioned in the application note, there are two
possible way of wiring pcie reset:
* connect gpio19 to all pcie reset pins
* connect gpio19 to pcie0 reset and pick two other
gpios for pcie1 and pcie2

gpio7 and gpio8 may not be used as pcie reset and are
vendor specific. Hence, maintain common mt7621.dtsi with
only gpio19 which is common and make an overlay for gnubee
board which uses all gpio's as resets for pcie. After this
changes release gpios in driver code is not needed anymore.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20200321072650.7784-2-sergio.paracuellos@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-21 10:31:54 +01:00
Gokce Kuler
5d6633b26b staging: mt7621-dma: quoted string split across lines
quoted string merge to upper line

Signed-off-by: Gokce Kuler <gokcekuler@gmail.com>
Link: https://lore.kernel.org/r/20200320232607.GA8601@siyah2
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-21 10:31:54 +01:00
Sergio Paracuellos
5737cfe87a staging: mt7621-pci: avoid to poweroff the phy for slot one
Phy for slot 0 and 1 is shared and handled properly in slot 0.
If there is only one port in use,(slot 0) we shall not call the
'phy_power_off' function with an invalid slot because kernel
will crash with an unaligned access fault like the following:

mt7621-pci 1e140000.pcie: Error applying setting, reverse things back
mt7621-pci-phy 1e149000.pcie-phy: PHY for 0xbe149000 (dual port = 1)
mt7621-pci-phy 1e14a000.pcie-phy: PHY for 0xbe14a000 (dual port = 0)
mt7621-pci-phy 1e149000.pcie-phy: Xtal is 40MHz
mt7621-pci-phy 1e14a000.pcie-phy: Xtal is 40MHz
mt7621-pci 1e140000.pcie: pcie1 no card, disable it (RST & CLK)
Unhandled kernel unaligned access[#1]:
CPU: 3 PID: 111 Comm: kworker/3:2 Not tainted 5.6.0-rc3-00347-g825c6f470c62-dirty #9
Workqueue: events deferred_probe_work_func
$ 0   : 00000000 00000001 5f60d043 8fe1ba80
$ 4   : 0000010d 01eb9000 00000000 00000000
$ 8   : 294b4c00 80940000 00000008 000000ce
$12   : 2e303030 00000000 00000000 65696370
$16   : ffffffed 0000010d 8e373cd0 8214c1e0
$20   : 00000000 82144c80 82144680 8214c250
$24   : 00000018 803ef8f4
$28   : 8e372000 8e373c60 8214c080 803940e8
Hi    : 00000125
Lo    : 122f2000
epc   : 807b3328 mutex_lock+0x8/0x44
ra    : 803940e8 phy_power_off+0x28/0xb0
Status: 1100fc03        KERNEL EXL IE
Cause : 00800010 (ExcCode 04)
BadVA : 0000010d
PrId  : 0001992f (MIPS 1004Kc)
Modules linked in:
Process kworker/3:2 (pid: 111, threadinfo=(ptrval), task=(ptrval), tls=00000000)
Stack : 8e373cd0 803fe4f4 8e372000 8e373c90 8214c080 804fde1c 8e373c98 808d62f4
         8e373c78 00000000 8214c254 804fe648 1e160000 804f27b8 00000001 808d62f4
         00000000 00000001 8214c228 808d62f4 80930000 809a0000 8fd47e10 808d63d4
         808d62d4 8fd47e10 808d0000 808d0000 8e373cd0 8e373cd0 809e2a74 809db510
         809db510 00000006 00000001 00000000 00000000 00000000 01000000 1e1440ff
         ...
Call Trace:
[<807b3328>] mutex_lock+0x8/0x44
[<803940e8>] phy_power_off+0x28/0xb0
[<804fe648>] mt7621_pci_probe+0xc20/0xd18
[<80402ab8>] platform_drv_probe+0x40/0x94
[<80400a74>] really_probe+0x104/0x364
[<803feb74>] bus_for_each_drv+0x84/0xdc
[<80400924>] __device_attach+0xdc/0x120
[<803ffb5c>] bus_probe_device+0xa0/0xbc
[<80400124>] deferred_probe_work_func+0x7c/0xbc
[<800420e8>] process_one_work+0x230/0x450
[<80042638>] worker_thread+0x330/0x5fc
[<80048eb0>] kthread+0x12c/0x134
[<80007438>] ret_from_kernel_thread+0x14/0x1c
Code: 24050002  27bdfff8  8f830000 <c0850000> 14a00005  00000000  00600825  e0810000  1020fffa

Fixes: bf516f413f ("staging: mt7621-pci: use only two phys from device tree")
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20200320153837.20415-1-sergio.paracuellos@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-21 10:31:54 +01:00
Clark Williams
afa58b49ac thermal/x86_pkg_temp: Make pkg_temp_lock a raw_spinlock_t
The spinlock pkg_temp_lock has the potential of being taken in atomic
context because it can be acquired from the thermal IRQ vector.
It's static and limited scope so go ahead and make it a raw spinlock.

Signed-off-by: Clark Williams <williams@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20191008110021.2j44ayunal7fkb7i@linutronix.de
2020-03-21 10:01:02 +01:00
Marco Elver
f5d2313bd3 kcsan, trace: Make KCSAN compatible with tracing
Previously the system would lock up if ftrace was enabled together with
KCSAN. This is due to recursion on reporting if the tracer code is
instrumented with KCSAN.

To avoid this for all types of tracing, disable KCSAN instrumentation
for all of kernel/trace.

Furthermore, since KCSAN relies on udelay() to introduce delay, we have
to disable ftrace for udelay() (currently done for x86) in case KCSAN is
used together with lockdep and ftrace. The reason is that it may corrupt
lockdep IRQ flags tracing state due to a peculiar case of recursion
(details in Makefile comment).

Reported-by: Qian Cai <cai@lca.pw>
Tested-by: Qian Cai <cai@lca.pw>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:44:41 +01:00
Marco Elver
703b321501 kcsan: Introduce ASSERT_EXCLUSIVE_BITS(var, mask)
This introduces ASSERT_EXCLUSIVE_BITS(var, mask).
ASSERT_EXCLUSIVE_BITS(var, mask) will cause KCSAN to assume that the
following access is safe w.r.t. data races (however, please see the
docbook comment for disclaimer here).

For more context on why this was considered necessary, please see:

  http://lkml.kernel.org/r/1580995070-25139-1-git-send-email-cai@lca.pw

In particular, before this patch, data races between reads (that use
@mask bits of an access that should not be modified concurrently) and
writes (that change ~@mask bits not used by the readers) would have been
annotated with "data_race()" (or "READ_ONCE()"). However, doing so would
then hide real problems: we would no longer be able to detect harmful
races between reads to @mask bits and writes to @mask bits.

Therefore, by using ASSERT_EXCLUSIVE_BITS(var, mask), we accomplish:

  1. Avoid proliferation of specific macros at the call sites: by
     including a single mask in the argument list, we can use the same
     macro in a wide variety of call sites, regardless of how and which
     bits in a field each call site actually accesses.

  2. The existing code does not need to be modified (although READ_ONCE()
     may still be advisable if we cannot prove that the data race is
     always safe).

  3. We catch bugs where the exclusive bits are modified concurrently.

  4. We document properties of the current code.

Acked-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Qian Cai <cai@lca.pw>
2020-03-21 09:44:14 +01:00
Marco Elver
81af89e158 kcsan: Add kcsan_set_access_mask() support
When setting up an access mask with kcsan_set_access_mask(), KCSAN will
only report races if concurrent changes to bits set in access_mask are
observed. Conveying access_mask via a separate call avoids introducing
overhead in the common-case fast-path.

Acked-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:44:08 +01:00
Marco Elver
b738f6169f kcsan: Introduce kcsan_value_change type
Introduces kcsan_value_change type, which explicitly points out if we
either observed a value-change (TRUE), or we could not observe one but
cannot rule out a value-change happened (MAYBE). The MAYBE state can
either be reported or not, depending on configuration preferences.

A follow-up patch introduces the FALSE state, which should never be
reported.

No functional change intended.

Acked-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:44:03 +01:00
Marco Elver
b968a08f24 compiler.h, seqlock.h: Remove unnecessary kcsan.h includes
No we longer have to include kcsan.h, since the required KCSAN interface
for both compiler.h and seqlock.h are now provided by kcsan-checks.h.

Acked-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:43:57 +01:00
Marco Elver
f0f6928c2c kcsan: Move interfaces that affects checks to kcsan-checks.h
This moves functions that affect state changing the behaviour of
kcsan_check_access() to kcsan-checks.h. Since these are likely used with
kcsan_check_access() it makes more sense to have them in kcsan-checks.h,
to avoid including all of 'include/linux/kcsan.h'.

No functional change intended.

Acked-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:43:47 +01:00
Marco Elver
3a5b45e503 kcsan: Fix misreporting if concurrent races on same address
If there are at least 4 threads racing on the same address, it can
happen that one of the readers may observe another matching reader in
other_info. To avoid locking up, we have to consume 'other_info'
regardless, but skip the report. See the added comment for more details.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:43:41 +01:00
Marco Elver
80d4c47752 kcsan: Expose core configuration parameters as module params
This adds early_boot, udelay_{task,interrupt}, and skip_watch as module
params. The latter parameters are useful to modify at runtime to tune
KCSAN's performance on new systems. This will also permit auto-tuning
these parameters to maximize overall system performance and KCSAN's race
detection ability.

None of the parameters are used in the fast-path and referring to them
via static variables instead of CONFIG constants will not affect
performance.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Qian Cai <cai@lca.pw>
2020-03-21 09:43:35 +01:00
Marco Elver
a312013578 kcsan: Add test to generate conflicts via debugfs
Add 'test=<iters>' option to KCSAN's debugfs interface to invoke KCSAN
checks on a dummy variable. By writing 'test=<iters>' to the debugfs
file from multiple tasks, we can generate real conflicts, and trigger
data race reports.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:43:30 +01:00
Marco Elver
f97f713dc2 kcsan: Introduce ASSERT_EXCLUSIVE_*() macros
Introduces ASSERT_EXCLUSIVE_WRITER() and ASSERT_EXCLUSIVE_ACCESS(), which
may be used to assert properties of synchronization logic, where
violation cannot be detected as a normal data race.

Examples of the reports that may be generated:

    ==================================================================
    BUG: KCSAN: assert: race in test_thread / test_thread

    write to 0xffffffffab3d1540 of 8 bytes by task 466 on cpu 2:
     test_thread+0x8d/0x111
     debugfs_write.cold+0x32/0x44
     ...

    assert no writes to 0xffffffffab3d1540 of 8 bytes by task 464 on cpu 0:
     test_thread+0xa3/0x111
     debugfs_write.cold+0x32/0x44
     ...
    ==================================================================

    ==================================================================
    BUG: KCSAN: assert: race in test_thread / test_thread

    assert no accesses to 0xffffffffab3d1540 of 8 bytes by task 465 on cpu 1:
     test_thread+0xb9/0x111
     debugfs_write.cold+0x32/0x44
     ...

    read to 0xffffffffab3d1540 of 8 bytes by task 464 on cpu 0:
     test_thread+0x77/0x111
     debugfs_write.cold+0x32/0x44
     ...
    ==================================================================

Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:42:59 +01:00
Marco Elver
d591ec3db7 kcsan: Introduce KCSAN_ACCESS_ASSERT access type
The KCSAN_ACCESS_ASSERT access type may be used to introduce dummy reads
and writes to assert certain properties of concurrent code, where bugs
could not be detected as normal data races.

For example, a variable that is only meant to be written by a single
CPU, but may be read (without locking) by other CPUs must still be
marked properly to avoid data races. However, concurrent writes,
regardless if WRITE_ONCE() or not, would be a bug. Using
kcsan_check_access(&x, sizeof(x), KCSAN_ACCESS_ASSERT) would allow
catching such bugs.

To support KCSAN_ACCESS_ASSERT the following notable changes were made:

  * If an access is of type KCSAN_ASSERT_ACCESS, disable various filters
    that only apply to data races, so that all races that KCSAN observes are
    reported.
  * Bug reports that involve an ASSERT access type will be reported as
    "KCSAN: assert: race in ..." instead of "data-race"; this will help
    more easily distinguish them.
  * Update a few comments to just mention 'races' where we do not always
    mean pure data races.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:42:50 +01:00
Marco Elver
ed95f95c86 kcsan: Fix 0-sized checks
Instrumentation of arbitrary memory-copy functions, such as user-copies,
may be called with size of 0, which could lead to false positives.

To avoid this, add a comparison in check_access() for size==0, which
will be optimized out for constant sized instrumentation
(__tsan_{read,write}N), and therefore not affect the common-case
fast-path.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:42:42 +01:00
Marco Elver
8cfbb04fae kcsan: Clean up the main KCSAN Kconfig option
This patch cleans up the rules of the 'KCSAN' Kconfig option by:

  1. implicitly selecting 'STACKTRACE' instead of depending on it;
  2. depending on DEBUG_KERNEL, to avoid accidentally turning KCSAN on if
     the kernel is not meant to be a debug kernel;
  3. updating the short and long summaries.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:42:26 +01:00
Marco Elver
a249a73231 kcsan: Clarify Kconfig option KCSAN_IGNORE_ATOMICS
Clarify difference between options KCSAN_IGNORE_ATOMICS and
KCSAN_ASSUME_PLAIN_WRITES_ATOMIC in help text.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:42:21 +01:00
Marco Elver
1e6ee2f0fe kcsan: Add option to assume plain aligned writes up to word size are atomic
This adds option KCSAN_ASSUME_PLAIN_WRITES_ATOMIC. If enabled, plain
aligned writes up to word size are assumed to be atomic, and also not
subject to other unsafe compiler optimizations resulting in data races.

This option has been enabled by default to reflect current kernel-wide
preferences.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:42:18 +01:00
Paul E. McKenney
7ad900d35b kcsan: Add docbook header for data_race()
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
2020-03-21 09:42:04 +01:00
Marco Elver
76d6f06c36 copy_to_user, copy_from_user: Use generic instrumented.h
This replaces the KASAN instrumentation with generic instrumentation,
implicitly adding KCSAN instrumentation support.

For KASAN no functional change is intended.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:41:59 +01:00
Marco Elver
d0ef4c360f iov_iter: Use generic instrumented.h
This replaces the kasan instrumentation with generic instrumentation,
implicitly adding KCSAN instrumentation support.

For KASAN no functional change is intended.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:41:55 +01:00
Marco Elver
27f937cc81 asm-generic, kcsan: Add KCSAN instrumentation for bitops
Add explicit KCSAN checks for bitops.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:41:46 +01:00
Marco Elver
ed8af2e4d2 asm-generic, atomic-instrumented: Use generic instrumented.h
This switches atomic-instrumented.h to use the generic instrumentation
wrappers provided by instrumented.h.

No functional change intended.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:41:42 +01:00
Marco Elver
36e4d4dd4f include/linux: Add instrumented.h infrastructure
This adds instrumented.h, which provides generic wrappers for memory
access instrumentation that the compiler cannot emit for various
sanitizers. Currently this unifies KASAN and KCSAN instrumentation. In
future this will also include KMSAN instrumentation.

Note that, copy_{to,from}_user should use special instrumentation, since
we should be able to instrument both source and destination memory
accesses if both are kernel memory.

The current patch only instruments the memory access where the address
is always in kernel space, however, both may in fact be kernel addresses
when a compat syscall passes an argument allocated in the kernel to a
real syscall. In a future change, both KASAN and KCSAN should check both
addresses in such cases, as well as KMSAN will make use of both
addresses. [It made more sense to provide the completed function
signature, rather than updating it and changing all locations again at a
later time.]

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:41:34 +01:00
Marco Elver
ad4f8eeca8 kcsan: Address missing case with KCSAN_REPORT_VALUE_CHANGE_ONLY
Even with KCSAN_REPORT_VALUE_CHANGE_ONLY, KCSAN still reports data
races between reads and watchpointed writes, even if the writes wrote
values already present.  This commit causes KCSAN to unconditionally
skip reporting in this case.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-21 09:41:29 +01:00