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Herbert Xu recently reported a problem concerning RCU and compiler
barriers. In the course of discussing the problem, he put forth a
litmus test which illustrated a serious defect in the Linux Kernel
Memory Model's data-race-detection code [1].
The defect was that the LKMM assumed visibility and executes-before
ordering of plain accesses had to be mediated by marked accesses. In
Herbert's litmus test this wasn't so, and the LKMM claimed the litmus
test was allowed and contained a data race although neither is true.
In fact, plain accesses can be ordered by fences even in the absence
of marked accesses. In most cases this doesn't matter, because most
fences only order accesses within a single thread. But the rcu-fence
relation is different; it can order (and induce visibility between)
accesses in different threads -- events which otherwise might be
concurrent. This makes it relevant to data-race detection.
This patch makes two changes to the memory model to incorporate the
new insight:
If a store is separated by a fence from another access,
the store is necessarily visible to the other access (as
reflected in the ww-vis and wr-vis relations). Similarly,
if a load is separated by a fence from another access then
the load necessarily executes before the other access (as
reflected in the rw-xbstar relation).
If a store is separated by a strong fence from a marked access
then it is necessarily visible to any access that executes
after the marked access (as reflected in the ww-vis and wr-vis
relations).
With these changes, the LKMM gives the desired result for Herbert's
litmus test and other related ones [2].
[1] https://lore.kernel.org/lkml/Pine.LNX.4.44L0.1906041026570.1731-100000@iolanthe.rowland.org/
[2] https://github.com/paulmckrcu/litmus/blob/master/manual/plain/C-S-rcunoderef-1.litmus
https://github.com/paulmckrcu/litmus/blob/master/manual/plain/C-S-rcunoderef-2.litmus
https://github.com/paulmckrcu/litmus/blob/master/manual/plain/C-S-rcunoderef-3.litmus
https://github.com/paulmckrcu/litmus/blob/master/manual/plain/C-S-rcunoderef-4.litmus
https://github.com/paulmckrcu/litmus/blob/master/manual/plain/strong-vis.litmus
Reported-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Tested-by: Akira Yokosawa <akiyks@gmail.com>
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This patch fixes the MAC address setup in the probe. The MAC address
retrieved using of_get_mac_address was checked for not containing an
error, but it may also be NULL which wasn't tested. Fix it by replacing
IS_ERR with IS_ERR_OR_NULL.
Fixes: 541ddc66d665 ("net: macb: support of_get_mac_address new ERR_PTR error")
Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Ask device connected on sink pad for link frequency
in order to configure CLK_LANE_REG1 (ui_x4).
If not available, ask for pixel rate information to compute it.
This is needed to deal with compressed format such as JPEG
where number of bits per pixel is unknown: computation of
link frequency from pixel rate is not possible.
Signed-off-by: Hugues Fruchet <hugues.fruchet@st.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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The sensor needs the MCLK clock running when it's being probed. On
platforms where the sensor is instantiated from a DT (MMP2) it is going
to happen asynchronously.
Therefore, the current modus operandi, where the bridge driver fiddles
with the sensor power and clock itself is not going to fly. As the comments
wisely note, this doesn't even belong there.
Luckily, the ov7670 driver is already able to control its power and
reset lines, we can just drop the MMP platform glue altogether.
It also requests the clock via the standard clock subsystem. Good -- let's
set up a clock instance so that the sensor can ask us to enable the clock.
Note that this is pretty dumb at the moment: the clock is hardwired to a
particular frequency and parent. It was always the case.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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An instance of a sensor on DT-based MMP2 platform is always going to be
created asynchronously.
Let's move the manual device creation away from the core to the Cafe
driver (used on OLPC XO-1, not present in DT) and set up appropriate
async matches: I2C on Cafe, FWNODE on MMP (OLPC XO-1.75).
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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The platform data is actually not used anywhere (along with the CSI
support) and should be safe to remove.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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Use the names more suitable for devicetree bindings.
There are no board files utilizing this, thus we seem to be at liberty
at renaming this without consequences.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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The access to REG_CLKCTRL or REG_CTRL1 without the clock enabled hangs
the machine. Enable the clock first.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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Remove structure members and headers that are not actually used. Saves
us from some noise in subsequent cleanup commits.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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stability"
This accesses the clock registers directly and thus is going to stay in the
way of making the driver devicetree friendly.
No boards seems to actually use this. If it's somehow actually needed it
needs to be done differently.
This reverts commit 7c269f454e7a51b151d94f99344120efa1cd0acb.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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In the patch refactoring the fw-node, the mt9m111 was broken for all
platform_data based platforms, which were the first aim of this
driver. Only the devicetree platform are still functional, probably
because the testing was done on these.
The result is that -EINVAL is systematically return for such platforms,
what this patch fixes.
[Sakari Ailus: Rework this to resolve a merge conflict and use dev_fwnode]
Fixes: 98480d65c48c ("media: mt9m111: allow to setup pixclk polarity")
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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of a client
We have a dedicated pointer for that, so use it. Much easier to read and
less computation involved.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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a client
We have a dedicated pointer for that, so use it. Much easier to read and
less computation involved.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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client
We have a dedicated pointer for that, so use it. Much easier to read and
less computation involved.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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We have a dedicated pointer for that, so use it. Much easier to read and
less computation involved.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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We have a dedicated pointer for that, so use it. Much easier to read and
less computation involved.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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We have a dedicated pointer for that, so use it. Much easier to read and
less computation involved.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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We have a dedicated pointer for that, so use it. Much easier to read and
less computation involved.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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We have a dedicated pointer for that, so use it. Much easier to read and
less computation involved.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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The mt9m111_power_on function did not properly clean up whenever it
encountered an error. Do that now.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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The regulator_get() function returns a regulator when it succeeds. There's
no need to check whether the regulator is NULL later on.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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Reported by sparse.
Fixes: 7f8e89a8f2fd ("vfio-ccw: Factor out the ccw0-to-ccw1 transition")
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20190624090721.16241-1-cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw into features
Refactoring of the vfio-ccw cp handling, simplifying the
code and avoiding unneeded allocating/copying.
* tag 'vfio-ccw-20190621' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw:
vfio-ccw: Remove copy_ccw_from_iova()
vfio-ccw: Factor out the ccw0-to-ccw1 transition
vfio-ccw: Copy CCW data outside length calculation
vfio-ccw: Skip second copy of guest cp to host
vfio-ccw: Move guest_cp storage into common struct
s390/cio: Combine direct and indirect CCW paths
vfio-ccw: Rearrange IDAL allocation in direct CCW
vfio-ccw: Remove pfn_array_table
vfio-ccw: Adjust the first IDAW outside of the nested loops
vfio-ccw: Rearrange pfn_array and pfn_array_table arrays
s390/cio: Use generalized CCW handler in cp_init()
s390/cio: Generalize the TIC handler
s390/cio: Refactor the routine that handles TIC CCWs
s390/cio: Squash cp_free() and cp_unpin_free()
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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syzbot found we can leak memory in packet_set_ring(), if user application
provides buggy parameters.
Fixes: 7f953ab2ba46 ("af_packet: TX_RING support for TPACKET_V3")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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With commit 94850257cf0f ("tls: Fix tls_device handling of partial records")
a new path was introduced to cleanup partial records during sk_proto_close.
This path does not handle the SW KTLS tx_list cleanup.
This is unnecessary though since the free_resources calls for both
SW and offload paths will cleanup a partial record.
The visible effect is the following warning, but this bug also causes
a page double free.
WARNING: CPU: 7 PID: 4000 at net/core/stream.c:206 sk_stream_kill_queues+0x103/0x110
RIP: 0010:sk_stream_kill_queues+0x103/0x110
RSP: 0018:ffffb6df87e07bd0 EFLAGS: 00010206
RAX: 0000000000000000 RBX: ffff8c21db4971c0 RCX: 0000000000000007
RDX: ffffffffffffffa0 RSI: 000000000000001d RDI: ffff8c21db497270
RBP: ffff8c21db497270 R08: ffff8c29f4748600 R09: 000000010020001a
R10: ffffb6df87e07aa0 R11: ffffffff9a445600 R12: 0000000000000007
R13: 0000000000000000 R14: ffff8c21f03f2900 R15: ffff8c21f03b8df0
Call Trace:
inet_csk_destroy_sock+0x55/0x100
tcp_close+0x25d/0x400
? tcp_check_oom+0x120/0x120
tls_sk_proto_close+0x127/0x1c0
inet_release+0x3c/0x60
__sock_release+0x3d/0xb0
sock_close+0x11/0x20
__fput+0xd8/0x210
task_work_run+0x84/0xa0
do_exit+0x2dc/0xb90
? release_sock+0x43/0x90
do_group_exit+0x3a/0xa0
get_signal+0x295/0x720
do_signal+0x36/0x610
? SYSC_recvfrom+0x11d/0x130
exit_to_usermode_loop+0x69/0xb0
do_syscall_64+0x173/0x180
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x7fe9b9abc10d
RSP: 002b:00007fe9b19a1d48 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 0000000000000006 RCX: 00007fe9b9abc10d
RDX: 0000000000000002 RSI: 0000000000000080 RDI: 00007fe948003430
RBP: 00007fe948003410 R08: 00007fe948003430 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00005603739d9080
R13: 00007fe9b9ab9f90 R14: 00007fe948003430 R15: 0000000000000000
Fixes: 94850257cf0f ("tls: Fix tls_device handling of partial records")
Signed-off-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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It's not okay to cast a "u32 *" to "unsigned long *" when you are
doing a for_each_set_bit() loop because that will break on big
endian systems.
Fixes: 386145601b82 ("mfd: stmfx: Uninitialized variable in stmfx_irq_handler()")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Tested-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
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Initialize pidfd to an invalid descriptor, to fail gracefully on
those kernels that do not implement CLONE_PIDFD and leave pidfd
unchanged.
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Christian Brauner <christian@brauner.io>
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Give userspace a cheap and reliable way to tell whether CLONE_PIDFD is
supported by the kernel or not. The easiest way is to pass an invalid
file descriptor value in parent_tidptr, perform the syscall and verify
that parent_tidptr has been changed to a valid file descriptor value.
CLONE_PIDFD uses parent_tidptr to return pidfds. CLONE_PARENT_SETTID
will use parent_tidptr to return the tid of the parent. The two flags
cannot be used together. Old kernels that only support
CLONE_PARENT_SETTID will not verify the value pointed to by
parent_tidptr. This behavior is unchanged even with the introduction of
CLONE_PIDFD.
However, if CLONE_PIDFD is specified the kernel will currently check the
value pointed to by parent_tidptr before placing the pidfd in the memory
pointed to. EINVAL will be returned if the value in parent_tidptr is not
0.
If CLONE_PIDFD is supported and fd 0 is closed, then the returned pidfd
can and likely will be 0 and parent_tidptr will be unchanged. This means
userspace must either check CLONE_PIDFD support beforehand or check that
fd 0 is not closed when invoking CLONE_PIDFD.
The check for pidfd == 0 was introduced during the v5.2 merge window by
commit b3e583825266 ("clone: add CLONE_PIDFD") to ensure that
CLONE_PIDFD could be potentially extended by passing in flags through
the return argument.
However, that extension would look horrible, and with the upcoming
introduction of the clone3 syscall in v5.3 there is no need to extend
legacy clone syscall this way. (Even if it would need to be extended,
CLONE_DETACHED can be reused with CLONE_PIDFD.)
So remove the pidfd == 0 check. Userspace that needs to be portable to
kernels without CLONE_PIDFD support can then be advised to initialize
pidfd to -1 and check the pidfd value returned by CLONE_PIDFD.
Fixes: b3e583825266 ("clone: add CLONE_PIDFD")
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Christian Brauner <christian@brauner.io>
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git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux
Pull mtd fixes from Miquel Raynal:
- Set the raw NAND number of targets to the right value
- Fix a bug uncovered by a recent patch on Spansion SPI-NOR flashes
* tag 'mtd/fixes-for-5.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux:
mtd: spi-nor: use 16-bit WRR command when QE is set on spansion flashes
mtd: rawnand: initialize ntargets with maxchips
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"One fix for a bug in our context id handling on 64-bit hash CPUs,
which can lead to unrelated processes being able to read/write to each
other's virtual memory. See the commit for full details.
That is the fix for CVE-2019-12817.
This also adds a kernel selftest for the bug"
* tag 'powerpc-5.2-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
selftests/powerpc: Add test of fork with mapping above 512TB
powerpc/mm/64s/hash: Reallocate context ids on fork
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According to the i.MX6UL/L RM, table 3.1 "ARM Cortex A7 domain interrupt
summary", the interrupts for the PWM[1-4] go from 83 to 86.
Fixes: b9901fe84f02 ("ARM: dts: imx6ul: add pwm[1-4] nodes")
Signed-off-by: Sébastien Szymanski <sebastien.szymanski@armadeus.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
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The recent USB core code performs sanity checks for the given pipe and
EP types, and it can be hit by manipulated USB descriptors by syzbot.
For making syzbot happier, this patch introduces a local helper for a
sanity check in the driver side and calls it at each place before the
message handling, so that we can avoid the WARNING splats.
Reported-by: syzbot+d952e5e28f5fb7718d23@syzkaller.appspotmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Pull auxdisplay cleanup from Miguel Ojeda:
"A cleanup for two drivers in auxdisplay: convert them to use
vm_map_pages_zero() (Souptick Joarder)"
* tag 'auxdisplay-for-linus-v5.2-rc7' of git://github.com/ojeda/linux:
auxdisplay/ht16k33.c: Convert to use vm_map_pages_zero()
auxdisplay/cfag12864bfb.c: Convert to use vm_map_pages_zero()
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Currently during soft reboot(kexec_file_load) boot command line
arguments are not measured. Define hooks needed to measure kexec
command line arguments during soft reboot(kexec_file_load).
- A new ima hook ima_kexec_cmdline is defined to be called by the
kexec code.
- A new function process_buffer_measurement is defined to measure
the buffer hash into the IMA measurement list.
- A new func policy KEXEC_CMDLINE is defined to control the
measurement.
Signed-off-by: Prakhar Srivastava <prsriva02@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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In ALSA firewire-motu driver, some tracepoints are supported to probe
vendor-specific data fields for SPH and status/control messages in
payload of isochronous packet. At present, the events of tracepoints
are unique each of direction, however the pair of events has the
same structure and print format. It's possible to unify the pair.
This commit unifies the pair. From userspace, direction is specified
by filtering for src/dst fields in the structure.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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This reverts commit e703965a129cdd72ff74e248f8fbf0d617844527.
When creating this patch, I compared the value of src field to the
value of first byte of cip_header field (SID) in tracing event.
But in this test I used a device which has a quirk to transfer
isochronous packet with invalid SID. The original change is valid.
Fixes: e703965a129c ("ALSA: firewire-lib: fix inverted node IDs for amdtp_packet events")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Linux 5.2-rc6
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_set_opp_custom() receives a set of OPP supplies as its arguments and
the caller of it passes NULL when the supplies are not valid. But
_set_opp_custom(), by mistake, checks for error by performing
IS_ERR(old_supply) on it which will always evaluate to false.
The problem was spotted during of testing of upcoming update for the
NVIDIA Tegra CPUFreq driver.
Cc: stable <stable@vger.kernel.org>
Fixes: 7e535993fa4f ("OPP: Separate out custom OPP handler specific code")
Reported-by: Marc Dietrich <marvin24@gmx.de>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
[ Viresh: Massaged changelog ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
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This commit replaces printk with pr_debug, so we don't flood kernel log.
Signed-off-by: Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
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Since two new sysfs interface files are created for umwait control, add
an ABI document entry for the files:
/sys/devices/system/cpu/umwait_control/enable_c02
/sys/devices/system/cpu/umwait_control/max_time
[ tglx: Made the write value instructions readable ]
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Cc: "Borislav Petkov" <bp@alien8.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Andy Lutomirski" <luto@kernel.org>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Link: https://lkml.kernel.org/r/1560994438-235698-6-git-send-email-fenghua.yu@intel.com
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IA32_UMWAIT_CONTROL[31:2] determines the maximum time in TSC-quanta
that processor can stay in C0.1 or C0.2. A zero value means no maximum
time.
Each instruction sets its own deadline in the instruction's implicit
input EDX:EAX value. The instruction wakes up if the time-stamp counter
reaches or exceeds the specified deadline, or the umwait maximum time
expires, or a store happens in the monitored address range in umwait.
The administrator can write an unsigned 32-bit number to
/sys/devices/system/cpu/umwait_control/max_time to change the default
value. Note that a value of zero means there is no limit. The lower two
bits of the value must be zero.
[ tglx: Simplify the write function. Massage changelog ]
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: "Borislav Petkov" <bp@alien8.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Andy Lutomirski" <luto@kernel.org>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Link: https://lkml.kernel.org/r/1560994438-235698-5-git-send-email-fenghua.yu@intel.com
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C0.2 state in umwait and tpause instructions can be enabled or disabled
on a processor through IA32_UMWAIT_CONTROL MSR register.
By default, C0.2 is enabled and the user wait instructions results in
lower power consumption with slower wakeup time.
But in real time systems which require faster wakeup time although power
savings could be smaller, the administrator needs to disable C0.2 and all
umwait invocations from user applications use C0.1.
Create a sysfs interface which allows the administrator to control C0.2
state during run time.
Andy Lutomirski suggested to turn off local irqs before writing the MSR to
ensure the cached control value is not changed by a concurrent sysfs write
from a different CPU via IPI.
[ tglx: Simplified the update logic in the write function and got rid of
all the convoluted type casts. Added a shared update function and
made the namespace consistent. Moved the sysfs create invocation.
Massaged changelog ]
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: "Borislav Petkov" <bp@alien8.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Andy Lutomirski" <luto@kernel.org>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Link: https://lkml.kernel.org/r/1560994438-235698-4-git-send-email-fenghua.yu@intel.com
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umwait or tpause allows the processor to enter a light-weight
power/performance optimized state (C0.1 state) or an improved
power/performance optimized state (C0.2 state) for a period specified by
the instruction or until the system time limit or until a store to the
monitored address range in umwait.
IA32_UMWAIT_CONTROL MSR register allows the OS to enable/disable C0.2 on
the processor and to set the maximum time the processor can reside in C0.1
or C0.2.
By default C0.2 is enabled so the user wait instructions can enter the
C0.2 state to save more power with slower wakeup time.
Andy Lutomirski proposed to set the maximum umwait time to 100000 cycles by
default. A quote from Andy:
"What I want to avoid is the case where it works dramatically differently
on NO_HZ_FULL systems as compared to everything else. Also, UMWAIT may
behave a bit differently if the max timeout is hit, and I'd like that
path to get exercised widely by making it happen even on default
configs."
A sysfs interface to adjust the time and the C0.2 enablement is provided in
a follow up change.
[ tglx: Renamed MSR_IA32_UMWAIT_CONTROL_MAX_TIME to
MSR_IA32_UMWAIT_CONTROL_TIME_MASK because the constant is used as
mask throughout the code.
Massaged comments and changelog ]
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: "Borislav Petkov" <bp@alien8.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Link: https://lkml.kernel.org/r/1560994438-235698-3-git-send-email-fenghua.yu@intel.com
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umonitor, umwait, and tpause are a set of user wait instructions.
umonitor arms address monitoring hardware using an address. The
address range is determined by using CPUID.0x5. A store to
an address within the specified address range triggers the
monitoring hardware to wake up the processor waiting in umwait.
umwait instructs the processor to enter an implementation-dependent
optimized state while monitoring a range of addresses. The optimized
state may be either a light-weight power/performance optimized state
(C0.1 state) or an improved power/performance optimized state
(C0.2 state).
tpause instructs the processor to enter an implementation-dependent
optimized state C0.1 or C0.2 state and wake up when time-stamp counter
reaches specified timeout.
The three instructions may be executed at any privilege level.
The instructions provide power saving method while waiting in
user space. Additionally, they can allow a sibling hyperthread to
make faster progress while this thread is waiting. One example of an
application usage of umwait is when waiting for input data from another
application, such as a user level multi-threaded packet processing
engine.
Availability of the user wait instructions is indicated by the presence
of the CPUID feature flag WAITPKG CPUID.0x07.0x0:ECX[5].
Detailed information on the instructions and CPUID feature WAITPKG flag
can be found in the latest Intel Architecture Instruction Set Extensions
and Future Features Programming Reference and Intel 64 and IA-32
Architectures Software Developer's Manual.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: "Borislav Petkov" <bp@alien8.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Link: https://lkml.kernel.org/r/1560994438-235698-2-git-send-email-fenghua.yu@intel.com
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Clean up the vDSO code a bit by giving pvclock_page and hvclock_page
their actual types instead of u8[PAGE_SIZE]. This shouldn't
materially affect the generated code.
Heavily based on a patch from Linus.
[ tglx: Adapted to the unified VDSO code ]
Co-developed-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/6920c5188f8658001af1fc56fd35b815706d300c.1561241273.git.luto@kernel.org
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If register_qdisc fails, we should unregister
netdevice notifier.
Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: e0a7683d30e9 ("net/sched: cbs: fix port_rate miscalculation")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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SPI memory devices from different manufacturers have widely
different configurations for Status, Control and Configuration
registers. JEDEC 216C defines a new map for these common register
bits and their functions, and describes how the individual bits may
be accessed for a specific device. For the JEDEC 216B compliant
flashes, we can partially deduce Status and Configuration registers
functions by inspecting the 16th DWORD of BFPT. Older flashes that
don't declare the SFDP tables (SPANSION FL512SAIFG1 311QQ063 A ©11
SPANSION) let the software decide how to interact with these registers.
The commit dcb4b22eeaf4 ("spi-nor: s25fl512s supports region locking")
uncovered a probe error for s25fl512s, when the Quad Enable bit CR[1]
was set to one in the bootloader. When this bit is one, only the Write
Status (01h) command with two data byts may be used, the 01h command with
one data byte is not recognized and hence the error when trying to clear
the block protection bits.
Fix the above by using the Write Status (01h) command with two data bytes
when the Quad Enable bit is one.
Backward compatibility should be fine. The newly introduced
spi_nor_spansion_clear_sr_bp() is tightly coupled with the
spansion_quad_enable() function. Both assume that the Write Register
with 16 bits, together with the Read Configuration Register (35h)
instructions are supported.
Fixes: dcb4b22eeaf44f91 ("spi-nor: s25fl512s supports region locking")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Tested-by: Jonas Bonn <jonas@norrbonn.se>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>
Tested-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
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The code is executed with interrupts disabled, so it's safe to use
__this_cpu_write().
[ tglx: Massaged changelog ]
Signed-off-by: Muchun Song <smuchun@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: joel@joelfernandes.org
Cc: rostedt@goodmis.org
Cc: frederic@kernel.org
Cc: paulmck@linux.vnet.ibm.com
Cc: alexander.levin@verizon.com
Cc: peterz@infradead.org
Link: https://lkml.kernel.org/r/20190618143305.2038-1-smuchun@gmail.com
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The return value is fixed. Remove it and amend the callers.
[ tglx: Fixup arm/bL_switcher and powerpc/rtas ]
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20190613064813.8102-2-namit@vmware.com
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