A sequence counter write side critical section must be protected by some
form of locking to serialize writers. If the serialization primitive is
not disabling preemption implicitly, preemption has to be explicitly
disabled before entering the write side critical section.
There is no built-in debugging mechanism to verify that the lock used
for writer serialization is held and preemption is disabled. Some usage
sites like dma-buf have explicit lockdep checks for the writer-side
lock, but this covers only a small portion of the sequence counter usage
in the kernel.
Add new sequence counter types which allows to associate a lock to the
sequence counter at initialization time. The seqcount API functions are
extended to provide appropriate lockdep assertions depending on the
seqcount/lock type.
For sequence counters with associated locks that do not implicitly
disable preemption, preemption protection is enforced in the sequence
counter write side functions. This removes the need to explicitly add
preempt_disable/enable() around the write side critical sections: the
write_begin/end() functions for these new sequence counter types
automatically do this.
Introduce the following seqcount types with associated locks:
seqcount_spinlock_t
seqcount_raw_spinlock_t
seqcount_rwlock_t
seqcount_mutex_t
seqcount_ww_mutex_t
Extend the seqcount read and write functions to branch out to the
specific seqcount_LOCKTYPE_t implementation at compile-time. This avoids
kernel API explosion per each new seqcount_LOCKTYPE_t added. Add such
compile-time type detection logic into a new, internal, seqlock header.
Document the proper seqcount_LOCKTYPE_t usage, and rationale, at
Documentation/locking/seqlock.rst.
If lockdep is disabled, this lock association is compiled out and has
neither storage size nor runtime overhead.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-10-a.darwish@linutronix.de
Preemption must be disabled before entering a sequence count write side
critical section. Failing to do so, the seqcount read side can preempt
the write side section and spin for the entire scheduler tick. If that
reader belongs to a real-time scheduling class, it can spin forever and
the kernel will livelock.
Assert through lockdep that preemption is disabled for seqcount writers.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-9-a.darwish@linutronix.de
Asserting that preemption is enabled or disabled is a critical sanity
check. Developers are usually reluctant to add such a check in a
fastpath as reading the preemption count can be costly.
Extend the lockdep API with macros asserting that preemption is disabled
or enabled. If lockdep is disabled, or if the underlying architecture
does not support kernel preemption, this assert has no runtime overhead.
References: f54bb2ec02 ("locking/lockdep: Add IRQs disabled/enabled assertion APIs: ...")
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-8-a.darwish@linutronix.de
raw_seqcount_begin() has the same code as raw_read_seqcount(), with the
exception of masking the sequence counter's LSB before returning it to
the caller.
Note, raw_seqcount_begin() masks the counter's LSB before returning it
to the caller so that read_seqcount_retry() can fail if the counter is
odd -- without the overhead of an extra branching instruction.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-7-a.darwish@linutronix.de
seqlock.h is now included by kernel's RST documentation, but a small
number of the the exported seqlock.h functions are kernel-doc annotated.
Add kernel-doc for all seqlock.h exported APIs.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-6-a.darwish@linutronix.de
The seqlock.h seqcount_t and seqlock_t API definitions are presented in
the chronological order of their development rather than the order that
makes most sense to readers. This makes it hard to follow and understand
the header file code.
Group and reorder all of the exported seqlock.h functions according to
their function.
First, group together the seqcount_t standard read path functions:
- __read_seqcount_begin()
- raw_read_seqcount_begin()
- read_seqcount_begin()
since each function is implemented exactly in terms of the one above
it. Then, group the special-case seqcount_t readers on their own as:
- raw_read_seqcount()
- raw_seqcount_begin()
since the only difference between the two functions is that the second
one masks the sequence counter LSB while the first one does not. Note
that raw_seqcount_begin() can actually be implemented in terms of
raw_read_seqcount(), which will be done in a follow-up commit.
Then, group the seqcount_t write path functions, instead of injecting
unrelated seqcount_t latch functions between them, and order them as:
- raw_write_seqcount_begin()
- raw_write_seqcount_end()
- write_seqcount_begin_nested()
- write_seqcount_begin()
- write_seqcount_end()
- raw_write_seqcount_barrier()
- write_seqcount_invalidate()
which is the expected natural order. This also isolates the seqcount_t
latch functions into their own area, at the end of the sequence counters
section, and before jumping to the next one: sequential locks
(seqlock_t).
Do a similar grouping and reordering for seqlock_t "locking" readers vs.
the "conditionally locking or lockless" ones.
No implementation code was changed in any of the reordering above.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-5-a.darwish@linutronix.de
The seqcount_t latch reader example at the raw_write_seqcount_latch()
kernel-doc comment ends the latch read section with a manual smp memory
barrier and sequence counter comparison.
This is technically correct, but it is suboptimal: read_seqcount_retry()
already contains the same logic of an smp memory barrier and sequence
counter comparison.
End the latch read critical section example with read_seqcount_retry().
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-4-a.darwish@linutronix.de
Align the code samples and note sections inside kernel-doc comments with
tabs. This way they can be properly parsed and rendered by Sphinx. It
also makes the code samples easier to read from text editors.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-3-a.darwish@linutronix.de
Proper documentation for the design and usage of sequence counters and
sequential locks does not exist. Complete the seqlock.h documentation as
follows:
- Divide all documentation on a seqcount_t vs. seqlock_t basis. The
description for both mechanisms was intermingled, which is incorrect
since the usage constrains for each type are vastly different.
- Add an introductory paragraph describing the internal design of, and
rationale for, sequence counters.
- Document seqcount_t writer non-preemptibility requirement, which was
not previously documented anywhere, and provide a clear rationale.
- Provide template code for seqcount_t and seqlock_t initialization
and reader/writer critical sections.
- Recommend using seqlock_t by default. It implicitly handles the
serialization and non-preemptibility requirements of writers.
At seqlock.h:
- Remove references to brlocks as they've long been removed from the
kernel.
- Remove references to gcc-3.x since the kernel's minimum supported
gcc version is 4.9.
References: 0f6ed63b17 ("no need to keep brlock macros anymore...")
References: 6ec4476ac8 ("Raise gcc version requirement to 4.9")
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-2-a.darwish@linutronix.de
This patch moves ATOMIC_INIT from asm/atomic.h into linux/types.h.
This allows users of atomic_t to use ATOMIC_INIT without having to
include atomic.h as that way may lead to header loops.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lkml.kernel.org/r/20200729123105.GB7047@gondor.apana.org.au
Currently lockdep_types.h includes list.h without actually using any
of its macros or functions. All it needs are the type definitions
which were moved into types.h long ago. This potentially causes
inclusion loops because both are included by many core header
files.
This patch moves the list.h inclusion into lockdep.h. Note that
we could probably remove it completely but that could potentially
result in compile failures should any end users not include list.h
directly and also be unlucky enough to not get list.h via some other
header file.
Reported-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Petr Mladek <pmladek@suse.com>
Link: https://lkml.kernel.org/r/20200716063649.GA23065@gondor.apana.org.au
- Plug a load average accounting race which was introduced with a recent
optimization casing load average to show bogus numbers.
- Fix the rseq CPU id initialization for new tasks. sched_fork() does not
update the rseq CPU id so the id is the stale id of the parent task,
which can cause user space data corruption.
- Handle a 0 return value of task_h_load() correctly in the load balancer,
which does not decrease imbalance and therefore pulls until the maximum
number of loops is reached, which might be all tasks just created by a
fork bomb.
-----BEGIN PGP SIGNATURE-----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=bCPw
-----END PGP SIGNATURE-----
Merge tag 'sched-urgent-2020-07-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master
Pull scheduler fixes from Thomas Gleixner:
"A set of scheduler fixes:
- Plug a load average accounting race which was introduced with a
recent optimization casing load average to show bogus numbers.
- Fix the rseq CPU id initialization for new tasks. sched_fork() does
not update the rseq CPU id so the id is the stale id of the parent
task, which can cause user space data corruption.
- Handle a 0 return value of task_h_load() correctly in the load
balancer, which does not decrease imbalance and therefore pulls
until the maximum number of loops is reached, which might be all
tasks just created by a fork bomb"
* tag 'sched-urgent-2020-07-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/fair: handle case of task_h_load() returning 0
sched: Fix unreliable rseq cpu_id for new tasks
sched: Fix loadavg accounting race
- ensure we always have fully addressable memory in the dma coherent
pool (Nicolas Saenz Julienne)
-----BEGIN PGP SIGNATURE-----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=H248
-----END PGP SIGNATURE-----
Merge tag 'dma-mapping-5.8-6' of git://git.infradead.org/users/hch/dma-mapping into master
Pull dma-mapping fixes from Christoph Hellwig:
"Ensure we always have fully addressable memory in the dma coherent
pool (Nicolas Saenz Julienne)"
* tag 'dma-mapping-5.8-6' of git://git.infradead.org/users/hch/dma-mapping:
dma-pool: do not allocate pool memory from CMA
dma-pool: make sure atomic pool suits device
dma-pool: introduce dma_guess_pool()
dma-pool: get rid of dma_in_atomic_pool()
dma-direct: provide function to check physical memory area validity
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQSQHSd0lITzzeNWNm3h3BK/laaZPAUCXxGFQwAKCRDh3BK/laaZ
PDYzAP9bXxHQaRdetnj6lOGNWjmVmiHfntxHqkl6QjZf6e1WlwD+NRXayVTc+Lzw
M1pBK6kqovMQVWkyFfA3dTq/BZMzfAc=
=9GPn
-----END PGP SIGNATURE-----
Merge tag 'fuse-fixes-5.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse into master
Pull fuse fixes from Miklos Szeredi:
- two regressions in this cycle caused by the conversion of writepage
list to an rb_tree
- two regressions in v5.4 cause by the conversion to the new mount API
- saner behavior of fsconfig(2) for the reconfigure case
- an ancient issue with FS_IOC_{GET,SET}FLAGS ioctls
* tag 'fuse-fixes-5.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
fuse: Fix parameter for FS_IOC_{GET,SET}FLAGS
fuse: don't ignore errors from fuse_writepages_fill()
fuse: clean up condition for writepage sending
fuse: reject options on reconfigure via fsconfig(2)
fuse: ignore 'data' argument of mount(..., MS_REMOUNT)
fuse: use ->reconfigure() instead of ->remount_fs()
fuse: fix warning in tree_insert() and clean up writepage insertion
fuse: move rb_erase() before tree_insert()
dma-buf:
- sleeping atomic fix
amdgpu:
- Fix a race condition with KIQ
- Preemption fix
- Fix handling of fake MST encoders
- OLED panel fix
- Handle allocation failure in stream construction
- Renoir SMC fix
- SDMA 5.x fix
i915:
- FBC w/a stride fix
- Fix use-after-free fix on module reload
- Ignore irq enabling on the virtual engines to fix device sleep
- Use GTT when saving/restoring engine GPR
- Fix selftest sort function
vmwgfx:
- black screen fix
aspeed:
- fbcon init warn fix
-----BEGIN PGP SIGNATURE-----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=S5ph
-----END PGP SIGNATURE-----
Merge tag 'drm-fixes-2020-07-17-1' of git://anongit.freedesktop.org/drm/drm into master
Pull drm fixes from Dave Airlie:
"Weekly fixes pull, big bigger than I'd normally like, but they are
fairly scattered and small individually.
The vmwgfx one is a black screen regression, otherwise the largest is
an MST encoder fix for amdgpu which results in a WARN in some cases,
and a scattering of i915 fixes.
I'm tracking two regressions at the moment that hopefully we get
nailed down this week for rc7.
dma-buf:
- sleeping atomic fix
amdgpu:
- Fix a race condition with KIQ
- Preemption fix
- Fix handling of fake MST encoders
- OLED panel fix
- Handle allocation failure in stream construction
- Renoir SMC fix
- SDMA 5.x fix
i915:
- FBC w/a stride fix
- Fix use-after-free fix on module reload
- Ignore irq enabling on the virtual engines to fix device sleep
- Use GTT when saving/restoring engine GPR
- Fix selftest sort function
vmwgfx:
- black screen fix
aspeed:
- fbcon init warn fix"
* tag 'drm-fixes-2020-07-17-1' of git://anongit.freedesktop.org/drm/drm:
drm/amdgpu/sdma5: fix wptr overwritten in ->get_wptr()
drm/amdgpu/powerplay: Modify SMC message name for setting power profile mode
drm/amd/display: handle failed allocation during stream construction
drm/amd/display: OLED panel backlight adjust not work with external display connected
drm/amdgpu/display: create fake mst encoders ahead of time (v4)
drm/amdgpu: fix preemption unit test
drm/amdgpu/gfx10: fix race condition for kiq
drm/i915: Recalculate FBC w/a stride when needed
drm/i915: Move cec_notifier to intel_hdmi_connector_unregister, v2.
drm/i915/gt: Only swap to a random sibling once upon creation
drm/i915/gt: Ignore irq enabling on the virtual engines
drm/i915/perf: Use GTT when saving/restoring engine GPR
drm/i915/selftests: Fix compare functions provided for sorting
drm/vmwgfx: fix update of display surface when resolution changes
dmabuf: use spinlock to access dmabuf->name
drm/aspeed: Call drm_fbdev_generic_setup after drm_dev_register
Leading comma prevents arbitrary reordering of initialisation clauses.
The whole point of C99 initialisation is to allow any such reordering.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200711145954.GA1178171@localhost.localdomain
Currently lockdep_types.h includes list.h without actually using any
of its macros or functions. All it needs are the type definitions
which were moved into types.h long ago. This potentially causes
inclusion loops because both are included by many core header
files.
This patch moves the list.h inclusion into lockdep.h. Note that
we could probably remove it completely but that could potentially
result in compile failures should any end users not include list.h
directly and also be unlucky enough to not get list.h via some other
header file.
Reported-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Petr Mladek <pmladek@suse.com>
Link: https://lkml.kernel.org/r/20200716063649.GA23065@gondor.apana.org.au
Here are 3 driver core fixes for 5.8-rc6.
They resolve some issues found with the deferred probe code for some
types of devices on some embedded systems. They have been tested a
bunch and have been in linux-next for a while with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCXxBwLw8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ym99QCfTvYnzY9iqndGTqJrzsKwCy9wJUMAnjI907Ip
wKZCqOC4YC0cOITUYV5b
=q1lu
-----END PGP SIGNATURE-----
Merge tag 'driver-core-5.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core into master
Pull driver core fixes from Greg KH:
"Here are 3 driver core fixes for 5.8-rc6.
They resolve some issues found with the deferred probe code for some
types of devices on some embedded systems. They have been tested a
bunch and have been in linux-next for a while with no reported issues"
* tag 'driver-core-5.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
driver core: Avoid deferred probe due to fw_devlink_pause/resume()
driver core: Rename dev_links_info.defer_sync to defer_hook
driver core: Don't do deferred probe in parallel with kernel_init thread
Here are some small tty and serial driver fixes for 5.8-rc6.
The largest set of patches in here is a revert of the sysrq changes that
went into 5.8-rc1 but turned out to cause a noticable overhead and cpu
usage.
Other than that, there's a few small serial driver fixes to resolve
reported issues, and finally resolving the spinlock init problem on many
serial driver consoles.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCXxBx8g8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ykqAwCeIWhRt4Z6YdUXjT/rFycYlFKWCVsAoJodlx6C
7FoXKFoP4c72il+qgHMp
=cCbW
-----END PGP SIGNATURE-----
Merge tag 'tty-5.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty into master
Pull tty/serial driver fixes from Greg KH:
:Here are some small tty and serial driver fixes for 5.8-rc6.
The largest set of patches in here is a revert of the sysrq changes
that went into 5.8-rc1 but turned out to cause a noticable overhead
and cpu usage.
Other than that, there's a few small serial driver fixes to resolve
reported issues, and finally resolving the spinlock init problem on
many serial driver consoles.
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-5.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
serial: core: Initialise spin lock before use in uart_configure_port()
serial: mxs-auart: add missed iounmap() in probe failure and remove
serial: sh-sci: Initialize spinlock for uart console
Revert "tty: xilinx_uartps: Fix missing id assignment to the console"
serial: core: drop redundant sysrq checks
serial: core: fix sysrq overhead regression
Revert "serial: core: Refactor uart_unlock_and_check_sysrq()"
tty/serial: fix serial_core.c kernel-doc warnings
tty: serial: cpm_uart: Fix behaviour for non existing GPIOs
and stacktrace in dmesg log
* dmabuf: protect dmabuf->name with a spinlock; avoids sleeping in
atomic context
-----BEGIN PGP SIGNATURE-----
iQEzBAABCAAdFiEEchf7rIzpz2NEoWjlaA3BHVMLeiMFAl8POcoACgkQaA3BHVML
eiN2fgf+KtQtM/e6xYd+u2m7PB/neOHbi77MX/YiSQ0bPzh5qIUGALzQEerOAD/D
TqxOQQEbLewJKyJZfj47e4WAbZ/Zv6Lw7jqq6FlaXY9YKFwOZhlctI87wq304/ML
M5GWExGjyjlhkAFOF2q/fv4hoB1VqXA9GI7PfXyRB8KDzvxmnc2p/I/Q7mP1aaXw
HZmTWF/p52CYVBL22fEb+InzTs/oPaFoexM6Lj9aak2eSZQQGAbJqgKjdFr+b0x7
Oq/DdGgyXg4pLyJ0ZB96uvZjxn90b1mTz5zeEss72Nz9hg7HPVHe4T8bUgug1gcK
7lShxUEGg3yTDyvqqJ0H7YZ5E2Nbqg==
=pAPP
-----END PGP SIGNATURE-----
Merge tag 'drm-misc-fixes-2020-07-15' of git://anongit.freedesktop.org/drm/drm-misc into drm-fixes
* aspeed: setup fbdev console after registering device; avoids warning
and stacktrace in dmesg log
* dmabuf: protect dmabuf->name with a spinlock; avoids sleeping in
atomic context
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20200715171756.GA18606@linux-uq9g
dma_coherent_ok() checks if a physical memory area fits a device's DMA
constraints.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Previous patch changed handling of remount/reconfigure to ignore all
options, including those that are unknown to the fuse kernel fs. This was
done for backward compatibility, but this likely only affects the old
mount(2) API.
The new fsconfig(2) based reconfiguration could possibly be improved. This
would make the new API less of a drop in replacement for the old, OTOH this
is a good chance to get rid of some weirdnesses in the old API.
Several other behaviors might make sense:
1) unknown options are rejected, known options are ignored
2) unknown options are rejected, known options are rejected if the value
is changed, allowed otherwise
3) all options are rejected
Prior to the backward compatibility fix to ignore all options all known
options were accepted (1), even if they change the value of a mount
parameter; fuse_reconfigure() does not look at the config values set by
fuse_parse_param().
To fix that we'd need to verify that the value provided is the same as set
in the initial configuration (2). The major drawback is that this is much
more complex than just rejecting all attempts at changing options (3);
i.e. all options signify initial configuration values and don't make sense
on reconfigure.
This patch opts for (3) with the rationale that no mount options are
reconfigurable in fuse.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Pull input fixes from Dmitry Torokhov:
"A few quirks for the Elan touchpad driver, another Thinkpad is being
switched over from PS/2 to native RMI4 interface, and we gave a brand
new SW_MACHINE_COVER switch definition"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: elan_i2c - add more hardware ID for Lenovo laptops
Input: i8042 - add Lenovo XiaoXin Air 12 to i8042 nomux list
Revert "Input: elants_i2c - report resolution information for touch major"
Input: elan_i2c - only increment wakeup count on touch
Input: synaptics - enable InterTouch for ThinkPad X1E 1st gen
ARM: dts: n900: remove mmc1 card detect gpio
Input: add `SW_MACHINE_COVER`
I have a few KGDB-related fixes that I'd like to target for 5.8-rc5. They're
mostly fixes for build warnings, but there's also:
* Support for the qSupported and qXfer packets, which are necessary to pass
around GDB XML information which we need for the RISC-V GDB port to fully
function.
* Users can now select STRICT_KERNEL_RWX instead of forcing it on.
I know it's a bit late for rc5, as these are not critical it's not a big deal
if they don't make it in.
-----BEGIN PGP SIGNATURE-----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=kyQD
-----END PGP SIGNATURE-----
Merge tag 'riscv-for-linus-5.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V fixes from Palmer Dabbelt:
"I have a few KGDB-related fixes. They're mostly fixes for build
warnings, but there's also:
- Support for the qSupported and qXfer packets, which are necessary
to pass around GDB XML information which we need for the RISC-V GDB
port to fully function.
- Users can now select STRICT_KERNEL_RWX instead of forcing it on"
* tag 'riscv-for-linus-5.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: Avoid kgdb.h including gdb_xml.h to solve unused-const-variable warning
kgdb: Move the extern declaration kgdb_has_hit_break() to generic kgdb.h
riscv: Fix "no previous prototype" compile warning in kgdb.c file
riscv: enable the Kconfig prompt of STRICT_KERNEL_RWX
kgdb: enable arch to support XML packet.
Pull networking fixes from David Miller:
1) Restore previous behavior of CAP_SYS_ADMIN wrt loading networking
BPF programs, from Maciej Żenczykowski.
2) Fix dropped broadcasts in mac80211 code, from Seevalamuthu
Mariappan.
3) Slay memory leak in nl80211 bss color attribute parsing code, from
Luca Coelho.
4) Get route from skb properly in ip_route_use_hint(), from Miaohe Lin.
5) Don't allow anything other than ARPHRD_ETHER in llc code, from Eric
Dumazet.
6) xsk code dips too deeply into DMA mapping implementation internals.
Add dma_need_sync and use it. From Christoph Hellwig
7) Enforce power-of-2 for BPF ringbuf sizes. From Andrii Nakryiko.
8) Check for disallowed attributes when loading flow dissector BPF
programs. From Lorenz Bauer.
9) Correct packet injection to L3 tunnel devices via AF_PACKET, from
Jason A. Donenfeld.
10) Don't advertise checksum offload on ipa devices that don't support
it. From Alex Elder.
11) Resolve several issues in TCP MD5 signature support. Missing memory
barriers, bogus options emitted when using syncookies, and failure
to allow md5 key changes in established states. All from Eric
Dumazet.
12) Fix interface leak in hsr code, from Taehee Yoo.
13) VF reset fixes in hns3 driver, from Huazhong Tan.
14) Make loopback work again with ipv6 anycast, from David Ahern.
15) Fix TX starvation under high load in fec driver, from Tobias
Waldekranz.
16) MLD2 payload lengths not checked properly in bridge multicast code,
from Linus Lüssing.
17) Packet scheduler code that wants to find the inner protocol
currently only works for one level of VLAN encapsulation. Allow
Q-in-Q situations to work properly here, from Toke
Høiland-Jørgensen.
18) Fix route leak in l2tp, from Xin Long.
19) Resolve conflict between the sk->sk_user_data usage of bpf reuseport
support and various protocols. From Martin KaFai Lau.
20) Fix socket cgroup v2 reference counting in some situations, from
Cong Wang.
21) Cure memory leak in mlx5 connection tracking offload support, from
Eli Britstein.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (146 commits)
mlxsw: pci: Fix use-after-free in case of failed devlink reload
mlxsw: spectrum_router: Remove inappropriate usage of WARN_ON()
net: macb: fix call to pm_runtime in the suspend/resume functions
net: macb: fix macb_suspend() by removing call to netif_carrier_off()
net: macb: fix macb_get/set_wol() when moving to phylink
net: macb: mark device wake capable when "magic-packet" property present
net: macb: fix wakeup test in runtime suspend/resume routines
bnxt_en: fix NULL dereference in case SR-IOV configuration fails
libbpf: Fix libbpf hashmap on (I)LP32 architectures
net/mlx5e: CT: Fix memory leak in cleanup
net/mlx5e: Fix port buffers cell size value
net/mlx5e: Fix 50G per lane indication
net/mlx5e: Fix CPU mapping after function reload to avoid aRFS RX crash
net/mlx5e: Fix VXLAN configuration restore after function reload
net/mlx5e: Fix usage of rcu-protected pointer
net/mxl5e: Verify that rpriv is not NULL
net/mlx5: E-Switch, Fix vlan or qos setting in legacy mode
net/mlx5: Fix eeprom support for SFP module
cgroup: Fix sock_cgroup_data on big-endian.
selftests: bpf: Fix detach from sockmap tests
...
-----BEGIN PGP SIGNATURE-----
iQEzBAABCAAdFiEEGhZs6bAKwk/OTgTpSD+KveBX+j4FAl8H0fsACgkQSD+KveBX
+j4xwwf7BIordw3SH3O1gpmxBCx7/i+28BYjwY6Z0jgEisJp/nCx9gigu+Fx2Bxc
0b0CBz2IKkRYs42MmIEWBr2/jxKAoIrvf/rCohvUhRvMdZ8n0GNQTvGlzHCAaWdj
Shgj63ty7OP42yIMhrAtOMtPNdy0HrLVEk/ghZzcBhlYoAXS/GElgTEFmldWNfJ8
sAWx+nAd9IUR/+tDLsIiUntvApiRnTKYNrsiqXlWYW79OLHBHZtYySDb51t9NjYz
Luk96bDpPoyaz1EOboWkGO5FEq8EQS0XtqJ1G9WSkCAZsN8faVWmhaCFJi0bH1En
gYiCHhJ3TX1sx218Jfjj8UyNJnPqxQ==
=8fIi
-----END PGP SIGNATURE-----
Merge tag 'mlx5-fixes-2020-07-02' of git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux
Saeed Mahameed says:
====================
mlx5 fixes 2020-07-02
This series introduces some fixes to mlx5 driver.
V1->v2:
- Drop "ip -s" patch and mirred device hold reference patch.
- Will revise them in a later submission.
Please pull and let me know if there is any problem.
For -stable v5.2
('net/mlx5: Fix eeprom support for SFP module')
For -stable v5.4
('net/mlx5e: Fix 50G per lane indication')
For -stable v5.5
('net/mlx5e: Fix CPU mapping after function reload to avoid aRFS RX crash')
('net/mlx5e: Fix VXLAN configuration restore after function reload')
For -stable v5.7
('net/mlx5e: CT: Fix memory leak in cleanup')
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Reshuffle the (__)kernel_read and (__)kernel_write helpers, and ensure
all users of in-kernel file I/O use them if they don't use iov_iter
based methods already.
-----BEGIN PGP SIGNATURE-----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=eYsI
-----END PGP SIGNATURE-----
Merge tag 'cleanup-kernel_read_write' of git://git.infradead.org/users/hch/misc
Pull in-kernel read and write op cleanups from Christoph Hellwig:
"Cleanup in-kernel read and write operations
Reshuffle the (__)kernel_read and (__)kernel_write helpers, and ensure
all users of in-kernel file I/O use them if they don't use iov_iter
based methods already.
The new WARN_ONs in combination with syzcaller already found a missing
input validation in 9p. The fix should be on your way through the
maintainer ASAP".
[ This is prep-work for the real changes coming 5.9 ]
* tag 'cleanup-kernel_read_write' of git://git.infradead.org/users/hch/misc:
fs: remove __vfs_read
fs: implement kernel_read using __kernel_read
integrity/ima: switch to using __kernel_read
fs: add a __kernel_read helper
fs: remove __vfs_write
fs: implement kernel_write using __kernel_write
fs: check FMODE_WRITE in __kernel_write
fs: unexport __kernel_write
bpfilter: switch to kernel_write
autofs: switch to kernel_write
cachefiles: switch to kernel_write
- add a warning when the atomic pool is depleted (David Rientjes)
- protect the parameters of the new scatterlist helper macros
(Marek Szyprowski )
-----BEGIN PGP SIGNATURE-----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=KI5i
-----END PGP SIGNATURE-----
Merge tag 'dma-mapping-5.8-5' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping fixes from Christoph Hellwig:
- add a warning when the atomic pool is depleted (David Rientjes)
- protect the parameters of the new scatterlist helper macros (Marek
Szyprowski )
* tag 'dma-mapping-5.8-5' of git://git.infradead.org/users/hch/dma-mapping:
scatterlist: protect parameters of the sg_table related macros
dma-mapping: warn when coherent pool is depleted
-----BEGIN PGP SIGNATURE-----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=dfnJ
-----END PGP SIGNATURE-----
Merge tag 'gfs2-v5.8-rc4.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull gfs2 fixes from Andreas Gruenbacher:
"Fix gfs2 readahead deadlocks by adding a IOCB_NOIO flag that allows
gfs2 to use the generic fiel read iterator functions without having to
worry about being called back while holding locks".
* tag 'gfs2-v5.8-rc4.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Rework read and page fault locking
fs: Add IOCB_NOIO flag for generic_file_read_iter
With the earlier patch in this series, all devices that deferred probe
due to fw_devlink_pause() will have their probes delayed till the
deferred probe thread is kicked off during late_initcall. This will also
affect all their consumers.
This delayed probing in unnecessary. So this patch just keeps track of
the devices that had their probe deferred due to fw_devlink_pause() and
attempts to probe them once during fw_devlink_resume().
Fixes: 716a7a2596 ("driver core: fw_devlink: Add support for batching fwnode parsing")
Signed-off-by: Saravana Kannan <saravanak@google.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200701194259.3337652-4-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The defer_sync field is used as a hook to add the device to the
deferred_sync list. Rename it so that it's more meaningful for the next
patch that'll also use this field as a hook to a deferred_fw_devlink
list.
Signed-off-by: Saravana Kannan <saravanak@google.com>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200701194259.3337652-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There exists a sleep-while-atomic bug while accessing the dmabuf->name
under mutex in the dmabuffs_dname(). This is caused from the SELinux
permissions checks on a process where it tries to validate the inherited
files from fork() by traversing them through iterate_fd() (which
traverse files under spin_lock) and call
match_file(security/selinux/hooks.c) where the permission checks happen.
This audit information is logged using dump_common_audit_data() where it
calls d_path() to get the file path name. If the file check happen on
the dmabuf's fd, then it ends up in ->dmabuffs_dname() and use mutex to
access dmabuf->name. The flow will be like below:
flush_unauthorized_files()
iterate_fd()
spin_lock() --> Start of the atomic section.
match_file()
file_has_perm()
avc_has_perm()
avc_audit()
slow_avc_audit()
common_lsm_audit()
dump_common_audit_data()
audit_log_d_path()
d_path()
dmabuffs_dname()
mutex_lock()--> Sleep while atomic.
Call trace captured (on 4.19 kernels) is below:
___might_sleep+0x204/0x208
__might_sleep+0x50/0x88
__mutex_lock_common+0x5c/0x1068
__mutex_lock_common+0x5c/0x1068
mutex_lock_nested+0x40/0x50
dmabuffs_dname+0xa0/0x170
d_path+0x84/0x290
audit_log_d_path+0x74/0x130
common_lsm_audit+0x334/0x6e8
slow_avc_audit+0xb8/0xf8
avc_has_perm+0x154/0x218
file_has_perm+0x70/0x180
match_file+0x60/0x78
iterate_fd+0x128/0x168
selinux_bprm_committing_creds+0x178/0x248
security_bprm_committing_creds+0x30/0x48
install_exec_creds+0x1c/0x68
load_elf_binary+0x3a4/0x14e0
search_binary_handler+0xb0/0x1e0
So, use spinlock to access dmabuf->name to avoid sleep-while-atomic.
Cc: <stable@vger.kernel.org> [5.3+]
Signed-off-by: Charan Teja Kalla <charante@codeaurora.org>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Acked-by: Christian König <christian.koenig@amd.com>
[sumits: added comment to spinlock_t definition to avoid warning]
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/a83e7f0d-4e54-9848-4b58-e1acdbe06735@codeaurora.org
Currently all IRQ-tracking state is in task_struct, this means that
task_struct needs to be defined before we use it.
Especially for lockdep_assert_irq*() this can lead to header-hell.
Move the hardirq state into per-cpu variables to avoid the task_struct
dependency.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200623083721.512673481@infradead.org
While the nmi_enter() users did
trace_hardirqs_{off_prepare,on_finish}() there was no matching
lockdep_hardirqs_*() calls to complete the picture.
Introduce idtentry_{enter,exit}_nmi() to enable proper IRQ state
tracking across the NMIs.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200623083721.216740948@infradead.org
Currently, only riscv kgdb.c uses the kgdb_has_hit_break() to identify
the kgdb breakpoint. It causes other architectures will encounter the "no
previous prototype" warnings if the compile option has W=1. Moving the
declaration of extern kgdb_has_hit_break() from risc-v kgdb.h to generic
kgdb.h to avoid generating these warnings.
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
The XML packet could be supported by required architecture if the
architecture defines CONFIG_HAVE_ARCH_KGDB_QXFER_PKT and implement its own
kgdb_arch_handle_qxfer_pkt(). Except for the kgdb_arch_handle_qxfer_pkt(),
the architecture also needs to record the feature supported by gdb stub
into the kgdb_arch_gdb_stub_feature, and these features will be reported
to host gdb when gdb stub receives the qSupported packet.
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Device unit for port buffers size, xoff_threshold and xon_threshold is
cells. Fix a bug in driver where cell unit size was hard-coded to
128 bytes. This hard-coded value is buggy, as it is wrong for some hardware
versions.
Driver to read cell size from SBCAM register and translate bytes to cell
units accordingly.
In order to fix the bug, this patch exposes SBCAM (Shared buffer
capabilities mask) layout and defines.
If SBCAM.cap_cell_size is valid, use it for all bytes to cells
calculations. If not valid, fallback to 128.
Cell size do not change on the fly per device. Instead of issuing SBCAM
access reg command every time such translation is needed, cache it in
mlx5e_dcbx as part of mlx5e_dcbnl_initialize(). Pass dcbx.port_buff_cell_sz
as a param to every function that needs bytes to cells translation.
While fixing the bug, move MLX5E_BUFFER_CELL_SHIFT macro to
en_dcbnl.c, as it is only used by that file.
Fixes: 0696d60853 ("net/mlx5e: Receive buffer configuration")
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Reviewed-by: Huy Nguyen <huyn@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
In order for no_refcnt and is_data to be the lowest order two
bits in the 'val' we have to pad out the bitfield of the u8.
Fixes: ad0f75e5f5 ("cgroup: fix cgroup_sk_alloc() for sk_clone_lock()")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Several users of kallsyms_show_value() were performing checks not
during "open". Refactor everything needed to gain proper checks against
file->f_cred for modules, kprobes, and bpf.
-----BEGIN PGP SIGNATURE-----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=ib5Q
-----END PGP SIGNATURE-----
Merge tag 'kallsyms_show_value-v5.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull kallsyms fix from Kees Cook:
"Refactor kallsyms_show_value() users for correct cred.
I'm not delighted by the timing of getting these changes to you, but
it does fix a handful of kernel address exposures, and no one has
screamed yet at the patches.
Several users of kallsyms_show_value() were performing checks not
during "open". Refactor everything needed to gain proper checks
against file->f_cred for modules, kprobes, and bpf"
* tag 'kallsyms_show_value-v5.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
selftests: kmod: Add module address visibility test
bpf: Check correct cred for CAP_SYSLOG in bpf_dump_raw_ok()
kprobes: Do not expose probe addresses to non-CAP_SYSLOG
module: Do not expose section addresses to non-CAP_SYSLOG
module: Refactor section attr into bin attribute
kallsyms: Refactor kallsyms_show_value() to take cred
When evaluating access control over kallsyms visibility, credentials at
open() time need to be used, not the "current" creds (though in BPF's
case, this has likely always been the same). Plumb access to associated
file->f_cred down through bpf_dump_raw_ok() and its callers now that
kallsysm_show_value() has been refactored to take struct cred.
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: bpf@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: 7105e828c0 ("bpf: allow for correlation of maps and helpers in dump")
Signed-off-by: Kees Cook <keescook@chromium.org>
In order to perform future tests against the cred saved during open(),
switch kallsyms_show_value() to operate on a cred, and have all current
callers pass current_cred(). This makes it very obvious where callers
are checking the wrong credential in their "read" contexts. These will
be fixed in the coming patches.
Additionally switch return value to bool, since it is always used as a
direct permission check, not a 0-on-success, negative-on-error style
function return.
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
I realize that we fairly recently raised it to 4.8, but the fact is, 4.9
is a much better minimum version to target.
We have a number of workarounds for actual bugs in pre-4.9 gcc versions
(including things like internal compiler errors on ARM), but we also
have some syntactic workarounds for lacking features.
In particular, raising the minimum to 4.9 means that we can now just
assume _Generic() exists, which is likely the much better replacement
for a lot of very convoluted built-time magic with conditionals on
sizeof and/or __builtin_choose_expr() with same_type() etc.
Using _Generic also means that you will need to have a very recent
version of 'sparse', but thats easy to build yourself, and much less of
a hassle than some old gcc version can be.
The latest (in a long string) of reasons for minimum compiler version
upgrades was commit 5435f73d5c ("efi/x86: Fix build with gcc 4").
Ard points out that RHEL 7 uses gcc-4.8, but the people who stay back on
old RHEL versions persumably also don't build their own kernels anyway.
And maybe they should cross-built or just have a little side affair with
a newer compiler?
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The recent commit:
c6e7bd7afa ("sched/core: Optimize ttwu() spinning on p->on_cpu")
moved these lines in ttwu():
p->sched_contributes_to_load = !!task_contributes_to_load(p);
p->state = TASK_WAKING;
up before:
smp_cond_load_acquire(&p->on_cpu, !VAL);
into the 'p->on_rq == 0' block, with the thinking that once we hit
schedule() the current task cannot change it's ->state anymore. And
while this is true, it is both incorrect and flawed.
It is incorrect in that we need at least an ACQUIRE on 'p->on_rq == 0'
to avoid weak hardware from re-ordering things for us. This can fairly
easily be achieved by relying on the control-dependency already in
place.
The second problem, which makes the flaw in the original argument, is
that while schedule() will not change prev->state, it will read it a
number of times (arguably too many times since it's marked volatile).
The previous condition 'p->on_cpu == 0' was sufficient because that
indicates schedule() has completed, and will no longer read
prev->state. So now the trick is to make this same true for the (much)
earlier 'prev->on_rq == 0' case.
Furthermore, in order to make the ordering stick, the 'prev->on_rq = 0'
assignment needs to he a RELEASE, but adding additional ordering to
schedule() is an unwelcome proposition at the best of times, doubly so
for mere accounting.
Luckily we can push the prev->state load up before rq->lock, with the
only caveat that we then have to re-read the state after. However, we
know that if it changed, we no longer have to worry about the blocking
path. This gives us the required ordering, if we block, we did the
prev->state load before an (effective) smp_mb() and the p->on_rq store
needs not change.
With this we end up with the effective ordering:
LOAD p->state LOAD-ACQUIRE p->on_rq == 0
MB
STORE p->on_rq, 0 STORE p->state, TASK_WAKING
which ensures the TASK_WAKING store happens after the prev->state
load, and all is well again.
Fixes: c6e7bd7afa ("sched/core: Optimize ttwu() spinning on p->on_cpu")
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Dave Jones <davej@codemonkey.org.uk>
Tested-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Link: https://lkml.kernel.org/r/20200707102957.GN117543@hirez.programming.kicks-ass.net
Ahmed S. Darwish