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If a message comes in and we do not have the client in the table, then
try to load the module supplying that client using MODULE_ALIAS to find
it.
This duplicates the scheme seen in other netlink muxes (eg nfnetlink).
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into usb-next
Felipe writes:
usb: changes for v4.14 merge window
Not a big pull request this time around. Only 49 non-merge
commits. This pull request is, however, all over the place. Most of
the changes are in the bdc driver adding support for USB Phy layer and
PM.
Renesas adds support for R-Car H3 ES2.0 and R-Car M3-W SoCs.
Also here is PM_RUNTIME support for dwc3-keystone.
UDC Core got a DMA unmap fix to make sure we only unmap requests that
were, indeed, mapped.
Other than these, we have a lot of cleanups, many of them adding
'const' to several places.
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The macro size is valid. This change makes it less ambiguous.
Bounds check trap type for better security.
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Kamenee Arumugam <kamenee.arumugam@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
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Increase lid used in hfi1 driver to 32 bits. qib continues
to use 16 bit lids.
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Signed-off-by: Don Hiatt <don.hiatt@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
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Add 16B bypass packet support for UD traffic types.
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Signed-off-by: Don Hiatt <don.hiatt@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
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When address handle attributes are initialized, the LIDs are
transformed to be in the 32 bit LID space.
When constructing the header, hfi1 driver will look at the LID
to determine the packet header to be created.
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Signed-off-by: Don Hiatt <don.hiatt@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
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We introduce a struct hfi1_16b_header to support 16B headers.
16B bypass packets are received by the driver and processed
similar to 9B packets. Add basic support to handle 16B packets.
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Don Hiatt <don.hiatt@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
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rvt_check_ah() delegates lid verification to underlying
driver. Underlying driver uses different conditions to
check for dlid depending on whether the device supports
extended LIDs
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Signed-off-by: Don Hiatt <don.hiatt@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
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The pmtu field doens't have be stored in the QP structure
as it can easily be calculated when needed.
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
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We currently keep rt->rt6i_node pointing to the fib6_node for the route.
And some functions make use of this pointer to dereference the fib6_node
from rt structure, e.g. rt6_check(). However, as there is neither
refcount nor rcu taken when dereferencing rt->rt6i_node, it could
potentially cause crashes as rt->rt6i_node could be set to NULL by other
CPUs when doing a route deletion.
This patch introduces an rcu grace period before freeing fib6_node and
makes sure the functions that dereference it takes rcu_read_lock().
Note: there is no "Fixes" tag because this bug was there in a very
early stage.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The PCI pool API is deprecated. This commit replaces the PCI pool old
API by the appropriate function with the DMA pool API.
Signed-off-by: Romain Perier <romain.perier@collabora.com>
Reviewed-by: Peter Senna Tschudin <peter.senna@collabora.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Tested-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
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Add register details an channels definition for using the TSI
registers in the hwmon driver.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
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git://anongit.freedesktop.org/git/drm-intel into drm-next
Final pile of features for 4.14
- New ioctl to change NOA configurations, plus prep (Lionel)
- CCS (color compression) scanout support, based on the fancy new
modifier additions (Ville&Ben)
- Document i915 register macro style (Jani)
- Many more gen10/cnl patches (Rodrigo, Pualo, ...)
- More gpu reset vs. modeset duct-tape to restore the old way.
- prep work for cnl: hpd_pin reorg (Rodrigo), support for more power
wells (Imre), i2c pin reorg (Anusha)
- drm_syncobj support (Jason Ekstrand)
- forcewake vs gpu reset fix (Chris)
- execbuf speedup for the no-relocs fastpath, anv/vk low-overhead ftw (Chris)
- switch to idr/radixtree instead of the resizing ht for execbuf id->vma
lookups (Chris)
gvt:
- MMIO save/restore optimization (Changbin)
- Split workload scan vs. dispatch for more parallel exec (Ping)
- vGPU full 48bit ppgtt support (Joonas, Tina)
- vGPU hw id expose for perf (Zhenyu)
Bunch of work all over to make the igt CI runs more complete/stable.
Watch https://intel-gfx-ci.01.org/tree/drm-tip/shards-all.html for
progress in getting this ready. Next week we're going into production
mode (i.e. will send results to intel-gfx) on hsw, more platforms to
come.
Also, a new maintainer tram, I'm stepping out. Huge thanks to Jani for
being an awesome co-maintainer the past few years, and all the best
for Jani, Joonas&Rodrigo as the new maintainers!
* tag 'drm-intel-next-2017-08-18' of git://anongit.freedesktop.org/git/drm-intel: (179 commits)
drm/i915: Update DRIVER_DATE to 20170818
drm/i915/bxt: use NULL for GPIO connection ID
drm/i915: Mark the GT as busy before idling the previous request
drm/i915: Trivial grammar fix s/opt of/opt out of/ in comment
drm/i915: Replace execbuf vma ht with an idr
drm/i915: Simplify eb_lookup_vmas()
drm/i915: Convert execbuf to use struct-of-array packing for critical fields
drm/i915: Check context status before looking up our obj/vma
drm/i915: Don't use MI_STORE_DWORD_IMM on Sandybridge/vcs
drm/i915: Stop touching forcewake following a gen6+ engine reset
MAINTAINERS: drm/i915 has a new maintainer team
drm/i915: Split pin mapping into per platform functions
drm/i915/opregion: let user specify override VBT via firmware load
drm/i915/cnl: Reuse skl_wm_get_hw_state on Cannonlake.
drm/i915/gen10: implement gen 10 watermarks calculations
drm/i915/cnl: Fix LSPCON support.
drm/i915/vbt: ignore extraneous child devices for a port
drm/i915/cnl: Setup PAT Index.
drm/i915/edp: Allow alternate fixed mode for eDP if available.
drm/i915: Add support for drm syncobjs
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Pull networking fixes from David Miller:
1) Fix IGMP handling wrt VRF, from David Ahern.
2) Fix timer access to freed object in dccp, from Eric Dumazet.
3) Use kmalloc_array() in ptr_ring to avoid overflow cases which are
triggerable by userspace. Also from Eric Dumazet.
4) Fix infinite loop in unmapping cleanup of nfp driver, from Colin Ian
King.
5) Correct datagram peek handling of empty SKBs, from Matthew Dawson.
6) Fix use after free in TIPC, from Eric Dumazet.
7) When replacing a route in ipv6 we need to reset the round robin
pointer, from Wei Wang.
8) Fix bug in pci_find_pcie_root_port() which was unearthed by the
relaxed ordering changes, from Thierry Redding. I made sure to get
an explicit ACK from Bjorn this time around :-)
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (27 commits)
ipv6: repair fib6 tree in failure case
net_sched: fix order of queue length updates in qdisc_replace()
tools lib bpf: improve warning
switchdev: documentation: minor typo fixes
bpf, doc: also add s390x as arch to sysctl description
net: sched: fix NULL pointer dereference when action calls some targets
rxrpc: Fix oops when discarding a preallocated service call
irda: do not leak initialized list.dev to userspace
net/mlx4_core: Enable 4K UAR if SRIOV module parameter is not enabled
PCI: Allow PCI express root ports to find themselves
tcp: when rearming RTO, if RTO time is in past then fire RTO ASAP
net: check and errout if res->fi is NULL when RTM_F_FIB_MATCH is set
ipv6: reset fn->rr_ptr when replacing route
sctp: fully initialize the IPv6 address in sctp_v6_to_addr()
tipc: fix use-after-free
tun: handle register_netdevice() failures properly
datagram: When peeking datagrams with offset < 0 don't skip empty skbs
bpf, doc: improve sysctl knob description
netxen: fix incorrect loop counter decrement
nfp: fix infinite loop on umapping cleanup
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This was reported many times, and this was even mentioned in commit
52ee2dfdd4f5 ("pids: refactor vnr/nr_ns helpers to make them safe") but
somehow nobody bothered to fix the obvious problem: task_tgid_nr_ns() is
not safe because task->group_leader points to nowhere after the exiting
task passes exit_notify(), rcu_read_lock() can not help.
We really need to change __unhash_process() to nullify group_leader,
parent, and real_parent, but this needs some cleanups. Until then we
can turn task_tgid_nr_ns() into another user of __task_pid_nr_ns() and
fix the problem.
Reported-by: Troy Kensinger <tkensinger@google.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:
- Removal of spin_unlock_wait()
- SRCU updates
- Torture-test updates
- Documentation updates
- Miscellaneous fixes
- CPU-hotplug fixes
- Miscellaneous non-RCU fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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This important to call qdisc_tree_reduce_backlog() after changing queue
length. Parent qdisc should deactivate class in ->qlen_notify() called from
qdisc_tree_reduce_backlog() but this happens only if qdisc->q.qlen in zero.
Missed class deactivations leads to crashes/warnings at picking packets
from empty qdisc and corrupting state at reactivating this class in future.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Fixes: 86a7996cc8a0 ("net_sched: introduce qdisc_replace() helper")
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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git://people.freedesktop.org/~gabbayo/linux into drm-next
This is the amdkfd pull request for 4.14 merge window.
AMD has started cleaning the pipe and sending patches from their internal
development to the upstream community.
The plan as I understand it is to first get all the non-dGPU patches to
upstream and then move to upstream dGPU support.
The patches here are relevant only for Kaveri and Carrizo.
The following is a summary of the changes:
- Add new IOCTL to set a Scratch memory VA
- Update PM4 headers for new firmware that support scratch memory
- Support image tiling mode
- Remove all uses of BUG_ON
- Various Bug fixes and coding style fixes
* tag 'drm-amdkfd-next-2017-08-18' of git://people.freedesktop.org/~gabbayo/linux: (24 commits)
drm/amdkfd: Implement image tiling mode support v2
drm/amdgpu: Add kgd kfd interface get_tile_config() v2
drm/amdkfd: Adding new IOCTL for scratch memory v2
drm/amdgpu: Add kgd/kfd interface to support scratch memory v2
drm/amdgpu: Program SH_STATIC_MEM_CONFIG globally, not per-VMID
drm/amd: Update MEC HQD loading code for KFD
drm/amdgpu: Disable GFX PG on CZ
drm/amdkfd: Update PM4 packet headers
drm/amdkfd: Clamp EOP queue size correctly on Gfx8
drm/amdkfd: Add more error printing to help bringup v2
drm/amdkfd: Handle remaining BUG_ONs more gracefully v2
drm/amdkfd: Allocate gtt_sa_bitmap in long units
drm/amdkfd: Fix doorbell initialization and finalization
drm/amdkfd: Remove BUG_ONs for NULL pointer arguments
drm/amdkfd: Remove usage of alloc(sizeof(struct...
drm/amdkfd: Fix goto usage v2
drm/amdkfd: Change x==NULL/false references to !x
drm/amdkfd: Consolidate and clean up log commands
drm/amdkfd: Clean up KFD style errors and warnings v2
drm/amdgpu: Remove hard-coded assumptions about compute pipes
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into devel
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into drm-next
More changes for 4.14. Highlights:
- command submission overhead improvements
- Huge page support for vega10
- physical mode support for mjpeg for asics that don't support UVD vm
- improve ttm_mem_type_manager_func debug
- misc ttm fixes, cleanups
- misc gpuvm cleanups
* 'drm-next-4.14' of git://people.freedesktop.org/~agd5f/linux: (26 commits)
drm/ttm: use reservation_object_trylock in ttm_bo_individualize_resv v2
drm/amdgpu: fix vega10 graphic hang issue in S3 test
drm/amdgpu: bump version for support of UVD MJPEG decode
drm/amdgpu: add MJPEG check for UVD physical mode msg buffer
drm/ttm: Fix accounting error when fail to get pages for pool
drm/amd/amdgpu: expose fragment size as module parameter (v2)
drm/amd/amdgpu: store fragment_size in vm_manager
drm/amdgpu: rename VM invalidated to moved
drm/amdgpu: separate bo_va structure
drm/amdgpu: drop the extra VM huge page flag v2
drm/amdgpu: remove superflous amdgpu_bo_kmap in the VM
drm/amdgpu: cleanup static CSA handling
drm/amdgpu: SHADOW and VRAM_CONTIGUOUS flags shouldn't be used by userspace
drm/amdgpu: save list length when fence is signaled
drm/amdgpu: move vram usage tracking into the vram manager v2
drm/amdgpu: move gtt usage tracking into the gtt manager v2
drm/amdgpu: move debug print into the MM managers
drm/amdgpu: fix incorrect use of the lru_lock
drm/radeon: fix incorrect use of the lru_lock
drm/ttm: make ttm_mem_type_manager_func debug more useful
...
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git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-linus
Jonathan writes:
Second set of IIO fixes for the 4.13 cycle.
Given the late stage of this series, some more involved fixes have been
held back for the upcoming merge window.
The hid-sensor issue has been causing problems for a long time so it
is great to have that one finally fixed! No more bug reports for the
userspace guys (well about that anyway).
* documentation
- some warning fixes due to missing colons in kernel-doc.
* adis16480
- fix accel scale factor.
* bmp280
- properly initialize the device for humidity readings - without this
the humidity readings may be skipped and a magic value of 0x8000 returned.
* hid-sensor-strigger
- fix a race with user space when powering up the sensor.
* ina291
- Avoid an underflow for the sleeping time as a result of supporting the
fastest rates.
* st-magnetometer
- Fix the status register address for hte LSM303AGR,
- Remove the ihl property for LSM303AGR as the sensor doesn't support
active low for the dataready line.
* stm32-adc
- Fix use of a common clock rate.
* stm32-timer
- fix the quadrature mode get routine to account for the magic 0 value.
set on boot.
- fix the return value of write_raw,
- fix the get/set down count direction as the enum value was not being
converted to the relevant bit field,
- add an enable attribute to actually turn it on when in encoder mode,
- missing mask when reading the trigger mode.
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git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next
Jonathan writes:
Second set of IIO new device support, features and cleanup for the 4.14 cycle.
New device support:
* ak8974
- support the AMI306.
* st_magnetometer
- add support for the LIS2MDL with bindings.
* rockchip-saradc
- add binding for rv1108 SoC (no driver change).
* srf08
- add srf02 (i2c only) and srf10 support.
* stm32-timer
- support for the STM32H7 to existing driver.
Features:
* tools
- move over to the tools buildsystem rather than hand rolling.
- add an install section to the build.
* ak8974
- use serial number to add device randomness.
- add AMI306 calibration data output.
* ccs811
- triggered buffer support.
* srf08
- add a device tree table as the old style i2c probing is going away,
- add triggered buffer support
* st32-adc
- add optional st,min-sample-time-nsecs binding to allow control of
sampling against analog circuitry.
* stm32-timer
- add output compare triggers.
* ti-ads1015
- add threshold event support.
* ti-ads7950
- Allow use on ACPI platforms including providing a default reference
voltage as there is no way to obtain this on ACPI currently.
Cleanup and fixes:
* ad7606
- fix an error return code in probe.
* ads1015
- fix incorrect data rate setting update when capture in progress,
- fix wrong scale information for the ADS1115,
- make conversions work when CONFIG_PM is not set,
- make sure we don't get a stale result after a runtime resume by
ensuring we wait long enough,
- avoid returning a false error form the buffer setup callbacks,
- add enough wait time to get the correct conversion,
- remove an unnecessary config register update,
- add a helper to set conversion mode reducing repeated boilerplate,
- use devm_iio_triggered_buffer_setup to simplify error and remove
paths,
- use iio_device_claim_direct_mode instead of opencoding the same.
* ak8974
- mark the INT_CLEAR register as precious to prevent debugfs access.
* apds9300
- constify the i2c_device_id.
* at91-sama5 adc
- add missing Kconfig dependency.
* bma180 accel
- constify the i2c_device_id.
* rockchip_saradc
- explicitly request exclusive reset control as part of the reset rework
on going throughout the kernel.
* st_accel
- fix drdy configuration for a load of accelerometers that only have
the int1 line. Fix is unimportant as presumably no deviec tree actually
used the non existent hardware line.
* st_pressure
- fix drdy configuration for LPS22HB and LPS25H by dropping int2 support
as they don't have this. Fix is unimportant as presumably no device tree
actually used the non existent hardware line.
* stm32-dac
- explicitly request exclusive reset control (part of reset being reworked).
* tsl2583
- constify the i2c_device_id.
* xadc
- coding style fixes.
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
"Two fixes for the perf subsystem:
- Fix an inconsistency of RDPMC mm struct tagging across exec() which
causes RDPMC to fault.
- Correct the timestamp mechanics across IOC_DISABLE/ENABLE which
causes incorrect timestamps and total time calculations"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Fix time on IOC_ENABLE
perf/x86: Fix RDPMC vs. mm_struct tracking
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull watchdog fix from Thomas Gleixner:
"A fix for the hardlockup watchdog to prevent false positives with
extreme Turbo-Modes which make the perf/NMI watchdog fire faster than
the hrtimer which is used to verify.
Slightly larger than the minimal fix, which just would increase the
hrtimer frequency, but comes with extra overhead of more watchdog
timer interrupts and thread wakeups for all users.
With this change we restrict the overhead to the extreme Turbo-Mode
systems"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
kernel/watchdog: Prevent false positives with turbo modes
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The kerneldoc description for the trig_readonly field of struct iio_dev
lacked a colon, leading to this doc build warning:
./include/linux/iio/iio.h:603: warning: No description found for parameter 'trig_readonly'
A similar issue for iio_trigger_set_immutable() in trigger.h yielded:
./include/linux/iio/trigger.h:151: warning: No description found for parameter 'indio_dev'
./include/linux/iio/trigger.h:151: warning: No description found for parameter 'trig'
Fix the formatting and silence the warnings.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
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Wenwei Tao has noticed that our current assumption that the oom victim
is dying and never doing any visible changes after it dies, and so the
oom_reaper can tear it down, is not entirely true.
__task_will_free_mem consider a task dying when SIGNAL_GROUP_EXIT is set
but do_group_exit sends SIGKILL to all threads _after_ the flag is set.
So there is a race window when some threads won't have
fatal_signal_pending while the oom_reaper could start unmapping the
address space. Moreover some paths might not check for fatal signals
before each PF/g-u-p/copy_from_user.
We already have a protection for oom_reaper vs. PF races by checking
MMF_UNSTABLE. This has been, however, checked only for kernel threads
(use_mm users) which can outlive the oom victim. A simple fix would be
to extend the current check in handle_mm_fault for all tasks but that
wouldn't be sufficient because the current check assumes that a kernel
thread would bail out after EFAULT from get_user*/copy_from_user and
never re-read the same address which would succeed because the PF path
has established page tables already. This seems to be the case for the
only existing use_mm user currently (virtio driver) but it is rather
fragile in general.
This is even more fragile in general for more complex paths such as
generic_perform_write which can re-read the same address more times
(e.g. iov_iter_copy_from_user_atomic to fail and then
iov_iter_fault_in_readable on retry).
Therefore we have to implement MMF_UNSTABLE protection in a robust way
and never make a potentially corrupted content visible. That requires
to hook deeper into the PF path and check for the flag _every time_
before a pte for anonymous memory is established (that means all
!VM_SHARED mappings).
The corruption can be triggered artificially
(http://lkml.kernel.org/r/201708040646.v746kkhC024636@www262.sakura.ne.jp)
but there doesn't seem to be any real life bug report. The race window
should be quite tight to trigger most of the time.
Link: http://lkml.kernel.org/r/20170807113839.16695-3-mhocko@kernel.org
Fixes: aac453635549 ("mm, oom: introduce oom reaper")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Wenwei Tao <wenwei.tww@alibaba-inc.com>
Tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andrea Argangeli <andrea@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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There is existing use after free bug when deferred struct pages are
enabled:
The memblock_add() allocates memory for the memory array if more than
128 entries are needed. See comment in e820__memblock_setup():
* The bootstrap memblock region count maximum is 128 entries
* (INIT_MEMBLOCK_REGIONS), but EFI might pass us more E820 entries
* than that - so allow memblock resizing.
This memblock memory is freed here:
free_low_memory_core_early()
We access the freed memblock.memory later in boot when deferred pages
are initialized in this path:
deferred_init_memmap()
for_each_mem_pfn_range()
__next_mem_pfn_range()
type = &memblock.memory;
One possible explanation for why this use-after-free hasn't been hit
before is that the limit of INIT_MEMBLOCK_REGIONS has never been
exceeded at least on systems where deferred struct pages were enabled.
Tested by reducing INIT_MEMBLOCK_REGIONS down to 4 from the current 128,
and verifying in qemu that this code is getting excuted and that the
freed pages are sane.
Link: http://lkml.kernel.org/r/1502485554-318703-2-git-send-email-pasha.tatashin@oracle.com
Fixes: 7e18adb4f80b ("mm: meminit: initialise remaining struct pages in parallel with kswapd")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
These are the few pending fixes I have queued up for v4.13-final. One
is a a generic regression fix for recursive loops on kmod and the other
one is a trivial print out correction.
During the v4.13 development we assumed that recursive kmod loops were
no longer possible. Clearly that is not true. The regression fix makes
use of a new killable wait. We use a killable wait to be paranoid in
how signals might be sent to modprobe and only accept a proper SIGKILL.
The signal will only be available to userspace to issue *iff* a thread
has already entered a wait state, and that happens only if we've already
throttled after 50 kmod threads have been hit.
Note that although it may seem excessive to trigger a failure afer 5
seconds if all kmod thread remain busy, prior to the series of changes
that went into v4.13 we would actually *always* fatally fail any request
which came in if the limit was already reached. The new waiting
implemented in v4.13 actually gives us *more* breathing room -- the wait
for 5 seconds is a wait for *any* kmod thread to finish. We give up and
fail *iff* no kmod thread has finished and they're *all* running
straight for 5 consecutive seconds. If 50 kmod threads are running
consecutively for 5 seconds something else must be really bad.
Recursive loops with kmod are bad but they're also hard to implement
properly as a selftest without currently fooling current userspace tools
like kmod [1]. For instance kmod will complain when you run depmod if
it finds a recursive loop with symbol dependency between modules as such
this type of recursive loop cannot go upstream as the modules_install
target will fail after running depmod.
These tests already exist on userspace kmod upstream though (refer to
the testsuite/module-playground/mod-loop-*.c files). The same is not
true if request_module() is used though, or worst if aliases are used.
Likewise the issue with 64-bit kernels booting 32-bit userspace without
a binfmt handler built-in is also currently not detected and proactively
avoided by userspace kmod tools, or kconfig for all architectures.
Although we could complain in the kernel when some of these individual
recursive issues creep up, proactively avoiding these situations in
userspace at build time is what we should keep striving for.
Lastly, since recursive loops could happen with kmod it may mean
recursive loops may also be possible with other kernel usermode helpers,
this should be investigated and long term if we can come up with a more
sensible generic solution even better!
[0] https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git/log/?h=20170809-kmod-for-v4.13-final
[1] https://git.kernel.org/pub/scm/utils/kernel/kmod/kmod.git
This patch (of 3):
This wait is similar to wait_event_interruptible_timeout() but only
accepts SIGKILL interrupt signal. Other signals are ignored.
Link: http://lkml.kernel.org/r/20170809234635.13443-2-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michal Marek <mmarek@suse.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Daniel Mentz <danielmentz@google.com>
Cc: David Binderman <dcb314@hotmail.com>
Cc: Matt Redfearn <matt.redfearn@imgetc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Jaegeuk and Brad report a NULL pointer crash when writeback ending tries
to update the memcg stats:
BUG: unable to handle kernel NULL pointer dereference at 00000000000003b0
IP: test_clear_page_writeback+0x12e/0x2c0
[...]
RIP: 0010:test_clear_page_writeback+0x12e/0x2c0
Call Trace:
<IRQ>
end_page_writeback+0x47/0x70
f2fs_write_end_io+0x76/0x180 [f2fs]
bio_endio+0x9f/0x120
blk_update_request+0xa8/0x2f0
scsi_end_request+0x39/0x1d0
scsi_io_completion+0x211/0x690
scsi_finish_command+0xd9/0x120
scsi_softirq_done+0x127/0x150
__blk_mq_complete_request_remote+0x13/0x20
flush_smp_call_function_queue+0x56/0x110
generic_smp_call_function_single_interrupt+0x13/0x30
smp_call_function_single_interrupt+0x27/0x40
call_function_single_interrupt+0x89/0x90
RIP: 0010:native_safe_halt+0x6/0x10
(gdb) l *(test_clear_page_writeback+0x12e)
0xffffffff811bae3e is in test_clear_page_writeback (./include/linux/memcontrol.h:619).
614 mod_node_page_state(page_pgdat(page), idx, val);
615 if (mem_cgroup_disabled() || !page->mem_cgroup)
616 return;
617 mod_memcg_state(page->mem_cgroup, idx, val);
618 pn = page->mem_cgroup->nodeinfo[page_to_nid(page)];
619 this_cpu_add(pn->lruvec_stat->count[idx], val);
620 }
621
622 unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
623 gfp_t gfp_mask,
The issue is that writeback doesn't hold a page reference and the page
might get freed after PG_writeback is cleared (and the mapping is
unlocked) in test_clear_page_writeback(). The stat functions looking up
the page's node or zone are safe, as those attributes are static across
allocation and free cycles. But page->mem_cgroup is not, and it will
get cleared if we race with truncation or migration.
It appears this race window has been around for a while, but less likely
to trigger when the memcg stats were updated first thing after
PG_writeback is cleared. Recent changes reshuffled this code to update
the global node stats before the memcg ones, though, stretching the race
window out to an extent where people can reproduce the problem.
Update test_clear_page_writeback() to look up and pin page->mem_cgroup
before clearing PG_writeback, then not use that pointer afterward. It
is a partial revert of 62cccb8c8e7a ("mm: simplify lock_page_memcg()")
but leaves the pageref-holding callsites that aren't affected alone.
Link: http://lkml.kernel.org/r/20170809183825.GA26387@cmpxchg.org
Fixes: 62cccb8c8e7a ("mm: simplify lock_page_memcg()")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Jaegeuk Kim <jaegeuk@kernel.org>
Tested-by: Jaegeuk Kim <jaegeuk@kernel.org>
Reported-by: Bradley Bolen <bradleybolen@gmail.com>
Tested-by: Brad Bolen <bradleybolen@gmail.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: <stable@vger.kernel.org> [4.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Due to commit e6afc8ace6dd5cef5e812f26c72579da8806f5ac ("udp: remove
headers from UDP packets before queueing"), when udp packets are being
peeked the requested extra offset is always 0 as there is no need to skip
the udp header. However, when the offset is 0 and the next skb is
of length 0, it is only returned once. The behaviour can be seen with
the following python script:
from socket import *;
f=socket(AF_INET6, SOCK_DGRAM | SOCK_NONBLOCK, 0);
g=socket(AF_INET6, SOCK_DGRAM | SOCK_NONBLOCK, 0);
f.bind(('::', 0));
addr=('::1', f.getsockname()[1]);
g.sendto(b'', addr)
g.sendto(b'b', addr)
print(f.recvfrom(10, MSG_PEEK));
print(f.recvfrom(10, MSG_PEEK));
Where the expected output should be the empty string twice.
Instead, make sk_peek_offset return negative values, and pass those values
to __skb_try_recv_datagram/__skb_try_recv_from_queue. If the passed offset
to __skb_try_recv_from_queue is negative, the checked skb is never skipped.
__skb_try_recv_from_queue will then ensure the offset is reset back to 0
if a peek is requested without an offset, unless no packets are found.
Also simplify the if condition in __skb_try_recv_from_queue. If _off is
greater then 0, and off is greater then or equal to skb->len, then
(_off || skb->len) must always be true assuming skb->len >= 0 is always
true.
Also remove a redundant check around a call to sk_peek_offset in af_unix.c,
as it double checked if MSG_PEEK was set in the flags.
V2:
- Moved the negative fixup into __skb_try_recv_from_queue, and remove now
redundant checks
- Fix peeking in udp{,v6}_recvmsg to report the right value when the
offset is 0
V3:
- Marked new branch in __skb_try_recv_from_queue as unlikely.
Signed-off-by: Matthew Dawson <matthew@mjdsystems.ca>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
This patch series primarily increases sizes of variables that hold
lid values from 16 to 32 bits. Additionally, it adds a check in
the IB mad stack to verify a properly formatted MAD when OPA
extended LIDs are used.
Signed-off-by: Don Hiatt <don.hiatt@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
|
|
Conflicts:
drivers/infiniband/core/iwcm.c - The rdma_netlink patches in
HEAD and the iwarp cm workqueue fix (don't use WQ_MEM_RECLAIM,
we aren't safe for that context) touched the same code.
Signed-off-by: Doug Ledford <dledford@redhat.com>
|
|
A sockaddr_in structure on the stack getting passed into rdma_ip2gid
triggers this warning, since we memcpy into a larger sockaddr_in6
structure:
In function 'memcpy',
inlined from 'rdma_ip2gid' at include/rdma/ib_addr.h:175:3,
inlined from 'addr_event.isra.4.constprop' at drivers/infiniband/core/roce_gid_mgmt.c:693:2,
inlined from 'inetaddr_event' at drivers/infiniband/core/roce_gid_mgmt.c:716:9:
include/linux/string.h:305:4: error: call to '__read_overflow2' declared with attribute error: detected read beyond size of object passed as 2nd parameter
The warning seems appropriate here, but the code is also clearly
correct, so we really just want to shut up this instance of the
output.
The best way I found so far is to avoid the memcpy() call and instead
replace it with a struct assignment.
Fixes: 6974f0c4555e ("include/linux/string.h: add the option of fortified string.h functions")
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>
|
|
Some drivers (specifically the nes IB driver), want to create a lot of
sysfs driver attributes. Instead of open-coding the creation and
removal of these files (and getting it wrong btw), it's a better idea to
let the driver core handle all of this logic for us.
So add a new field to the pci driver structure, **groups, that allows
pci drivers to specify an attribute group list it wishes to have created
when it is registered with the driver core.
Big bonus is now the driver doesn't race with userspace when the sysfs
files are created vs. when the kobject is announced, so any script/tool
that actually wanted to use these files will not have to poll waiting
for them to show up.
Cc: Faisal Latif <faisal.latif@intel.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
|
|
Archit requested this backmerge to facilitate merging some patches
depending on changes between -rc2 & -rc5
Signed-off-by: Sean Paul <seanpaul@chromium.org>
|
|
The hardlockup detector on x86 uses a performance counter based on unhalted
CPU cycles and a periodic hrtimer. The hrtimer period is about 2/5 of the
performance counter period, so the hrtimer should fire 2-3 times before the
performance counter NMI fires. The NMI code checks whether the hrtimer
fired since the last invocation. If not, it assumess a hard lockup.
The calculation of those periods is based on the nominal CPU
frequency. Turbo modes increase the CPU clock frequency and therefore
shorten the period of the perf/NMI watchdog. With extreme Turbo-modes (3x
nominal frequency) the perf/NMI period is shorter than the hrtimer period
which leads to false positives.
A simple fix would be to shorten the hrtimer period, but that comes with
the side effect of more frequent hrtimer and softlockup thread wakeups,
which is not desired.
Implement a low pass filter, which checks the perf/NMI period against
kernel time. If the perf/NMI fires before 4/5 of the watchdog period has
elapsed then the event is ignored and postponed to the next perf/NMI.
That solves the problem and avoids the overhead of shorter hrtimer periods
and more frequent softlockup thread wakeups.
Fixes: 58687acba592 ("lockup_detector: Combine nmi_watchdog and softlockup detector")
Reported-and-tested-by: Kan Liang <Kan.liang@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: dzickus@redhat.com
Cc: prarit@redhat.com
Cc: ak@linux.intel.com
Cc: babu.moger@oracle.com
Cc: peterz@infradead.org
Cc: eranian@google.com
Cc: acme@redhat.com
Cc: stable@vger.kernel.org
Cc: atomlin@redhat.com
Cc: akpm@linux-foundation.org
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1708150931310.1886@nanos
|
|
Merge the flow handlers and irq domain extensions which are in a separate
branch so they can be consumed by the gpio folks.
|
|
For an already existing irqdomain hierarchy, as might be obtained via
a call to pci_enable_msix_range(), a PCI driver wishing to add an
additional irqdomain to the hierarchy needs to be able to insert the
irqdomain to that already initialized hierarchy. Calling
irq_domain_create_hierarchy() allows the new irqdomain to be created,
but no existing code allows for initializing the associated irq_data.
Add a couple of helper functions (irq_domain_push_irq() and
irq_domain_pop_irq()) to initialize the irq_data for the new
irqdomain added to an existing hierarchy.
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-gpio@vger.kernel.org
Link: http://lkml.kernel.org/r/1503017616-3252-6-git-send-email-david.daney@cavium.com
|
|
Follow-on patch for gpio-thunderx uses a irqdomain hierarchy which
requires slightly different flow handlers, add them to chip.c which
contains most of the other flow handlers. Make these conditionally
compiled based on CONFIG_IRQ_FASTEOI_HIERARCHY_HANDLERS.
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-gpio@vger.kernel.org
Link: http://lkml.kernel.org/r/1503017616-3252-3-git-send-email-david.daney@cavium.com
|
|
Just because CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK is selected
doesn't mean that all the interrupts are using the effective
affinity mask. For a number of them, this mask is likely to
be empty.
In order to deal with this, let's restrict the use of the
effective affinity mask to these interrupts that have a non empty
effective affinity.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Wei Xu <xuwei5@hisilicon.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Link: http://lkml.kernel.org/r/20170818083925.10108-2-marc.zyngier@arm.com
|
|
We need the ASM_UNREACHABLE() macro for a dependent patch.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
For SoC to achieve its lowest power platform idle state a set of hardware
preconditions must be met. These preconditions or constraints can be
obtained by issuing a device specific method (_DSM) with function "1".
Refer to the document provided in the link below.
Here during initialization (from attach() callback of LPS0 device), invoke
function 1 to get the device constraints. Each enabled constraint is
stored in a table.
The devices in this table are used to check whether they were in required
minimum state, while entering suspend. This check is done from platform
freeze wake() callback, only when /sys/power/pm_debug_messages attribute
is non zero.
If any constraint is not met and device is ACPI power managed then it
prints the device information to kernel logs.
Also if debug is enabled in acpi/sleep.c, the constraint table and state
of each device on wake is dumped in kernel logs.
Since pm_debug_messages_on setting is used as condition to check
constraints outside kernel/power/main.c, pm_debug_messages_on is changed
to a global variable.
Link: http://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
|
Provide the drm printer directly instead of just the callback.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux into drm-next
omapdrm changes for v4.14
* HDMI hot plug IRQ support (instead of polling)
* Big driver cleanup from Laurent (no functional changes)
* OMAP5 DSI support (only the pinmuxing was missing)
* tag 'omapdrm-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux: (60 commits)
drm/omap: Potential NULL deref in omap_crtc_duplicate_state()
drm/omap: remove no-op cleanup code
drm/omap: rename omapdrm device back
drm: omapdrm: Remove omapdrm platform data
ARM: OMAP2+: Don't register omapdss device for omapdrm
ARM: OMAP2+: Remove unused omapdrm platform device
drm: omapdrm: Remove the omapdss driver
drm: omapdrm: Register omapdrm platform device in omapdss driver
drm: omapdrm: hdmi: Don't allocate PHY features dynamically
drm: omapdrm: hdmi: Configure the PHY from the HDMI core version
drm: omapdrm: hdmi: Configure the PLL from the HDMI core version
drm: omapdrm: hdmi: Pass HDMI core version as integer to HDMI audio
drm: omapdrm: hdmi: Replace OMAP SoC model check with HDMI xmit version
drm: omapdrm: hdmi: Rename functions and structures to use hdmi_ prefix
drm/omap: add OMAP5 DSIPHY lane-enable support
drm/omap: use regmap_update_bit() when muxing DSI pads
drm: omapdrm: Remove dss_features.h
drm: omapdrm: Move supported outputs feature to dss driver
drm: omapdrm: Move DSS_FCK feature to dss driver
drm: omapdrm: Move PCD, LINEWIDTH and DOWNSCALE features to dispc driver
...
|
|
Christian Brauner reported that if you use the TIOCGPTPEER ioctl() to
get a slave pty file descriptor, the resulting file descriptor doesn't
look right in /proc/<pid>/fd/<fd>. In particular, he wanted to use
readlink() on /proc/self/fd/<fd> to get the pathname of the slave pty
(basically implementing "ptsname{_r}()").
The reason for that was that we had generated the wrong 'struct path'
when we create the pty in ptmx_open().
In particular, the dentry was correct, but the vfsmount pointed to the
mount of the ptmx node. That _can_ be correct - in case you use
"/dev/pts/ptmx" to open the master - but usually is not. The normal
case is to use /dev/ptmx, which then looks up the pts/ directory, and
then the vfsmount of the ptmx node is obviously the /dev directory, not
the /dev/pts/ directory.
We actually did have the right vfsmount available, but in the wrong
place (it gets looked up in 'devpts_acquire()' when we get a reference
to the pts filesystem), and so ptmx_open() used the wrong mnt pointer.
The end result of this confusion was that the pty worked fine, but when
if you did TIOCGPTPEER to get the slave side of the pty, end end result
would also work, but have that dodgy 'struct path'.
And then when doing "d_path()" on to get the pathname, the vfsmount
would not match the root of the pts directory, and d_path() would return
an empty pathname thinking that the entry had escaped a bind mount into
another mount.
This fixes the problem by making devpts_acquire() return the vfsmount
for the pts filesystem, allowing ptmx_open() to trivially just use the
right mount for the pts dentry, and create the proper 'struct path'.
Reported-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
'hotplug.2017.07.25b', 'misc.2017.08.17a', 'spin_unlock_wait_no.2017.08.17a', 'srcu.2017.07.27c' and 'torture.2017.07.24c' into HEAD
doc.2017.08.17a: Documentation updates.
fixes.2017.08.17a: RCU fixes.
hotplug.2017.07.25b: CPU-hotplug updates.
misc.2017.08.17a: Miscellaneous fixes outside of RCU (give or take conflicts).
spin_unlock_wait_no.2017.08.17a: Remove spin_unlock_wait().
srcu.2017.07.27c: SRCU updates.
torture.2017.07.24c: Torture-test updates.
|
|
There is no agreed-upon definition of spin_unlock_wait()'s semantics,
and it appears that all callers could do just as well with a lock/unlock
pair. This commit therefore removes spin_unlock_wait() and related
definitions from core code.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Implement MEMBARRIER_CMD_PRIVATE_EXPEDITED with IPIs using cpumask built
from all runqueues for which current thread's mm is the same as the
thread calling sys_membarrier. It executes faster than the non-expedited
variant (no blocking). It also works on NOHZ_FULL configurations.
Scheduler-wise, it requires a memory barrier before and after context
switching between processes (which have different mm). The memory
barrier before context switch is already present. For the barrier after
context switch:
* Our TSO archs can do RELEASE without being a full barrier. Look at
x86 spin_unlock() being a regular STORE for example. But for those
archs, all atomics imply smp_mb and all of them have atomic ops in
switch_mm() for mm_cpumask(), and on x86 the CR3 load acts as a full
barrier.
* From all weakly ordered machines, only ARM64 and PPC can do RELEASE,
the rest does indeed do smp_mb(), so there the spin_unlock() is a full
barrier and we're good.
* ARM64 has a very heavy barrier in switch_to(), which suffices.
* PPC just removed its barrier from switch_to(), but appears to be
talking about adding something to switch_mm(). So add a
smp_mb__after_unlock_lock() for now, until this is settled on the PPC
side.
Changes since v3:
- Properly document the memory barriers provided by each architecture.
Changes since v2:
- Address comments from Peter Zijlstra,
- Add smp_mb__after_unlock_lock() after finish_lock_switch() in
finish_task_switch() to add the memory barrier we need after storing
to rq->curr. This is much simpler than the previous approach relying
on atomic_dec_and_test() in mmdrop(), which actually added a memory
barrier in the common case of switching between userspace processes.
- Return -EINVAL when MEMBARRIER_CMD_SHARED is used on a nohz_full
kernel, rather than having the whole membarrier system call returning
-ENOSYS. Indeed, CMD_PRIVATE_EXPEDITED is compatible with nohz_full.
Adapt the CMD_QUERY mask accordingly.
Changes since v1:
- move membarrier code under kernel/sched/ because it uses the
scheduler runqueue,
- only add the barrier when we switch from a kernel thread. The case
where we switch from a user-space thread is already handled by
the atomic_dec_and_test() in mmdrop().
- add a comment to mmdrop() documenting the requirement on the implicit
memory barrier.
CC: Peter Zijlstra <peterz@infradead.org>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: Andrew Hunter <ahh@google.com>
CC: Maged Michael <maged.michael@gmail.com>
CC: gromer@google.com
CC: Avi Kivity <avi@scylladb.com>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <paulus@samba.org>
CC: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Dave Watson <davejwatson@fb.com>
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There are cases where folks are using an interruptible swait when
using kthreads. This is rather confusing given you'd expect
interruptible waits to be -- interruptible, but kthreads are not
interruptible ! The reason for such practice though is to avoid
having these kthreads contribute to the system load average.
When systems are idle some kthreads may spend a lot of time blocking if
using swait_event_timeout(). This would contribute to the system load
average. On systems without preemption this would mean the load average
of an idle system is bumped to 2 instead of 0. On systems with PREEMPT=y
this would mean the load average of an idle system is bumped to 3
instead of 0.
This adds proper API using TASK_IDLE to make such goals explicit and
avoid confusion.
Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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Currently, the exit-time support for TASKS_RCU is open-coded in do_exit().
This commit creates exit_tasks_rcu_start() and exit_tasks_rcu_finish()
APIs for do_exit() use. This has the benefit of confining the use of the
tasks_rcu_exit_srcu variable to one file, allowing it to become static.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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