There is a small bug in the code that recomputes parts of bprm->cred
for every bprm->file. The code never recomputes the part of
clear_dangerous_personality_flags it is responsible for.
Which means that in practice if someone creates a sgid script
the interpreter will not be able to use any of:
READ_IMPLIES_EXEC
ADDR_NO_RANDOMIZE
ADDR_COMPAT_LAYOUT
MMAP_PAGE_ZERO.
This accentially clearing of personality flags probably does
not matter in practice because no one has complained
but it does make the code more difficult to understand.
Further remaining bug compatible prevents the recomputation from being
removed and replaced by simply computing bprm->cred once from the
final bprm->file.
Making this change removes the last behavior difference between
computing bprm->creds from the final file and recomputing
bprm->cred several times. Which allows this behavior change
to be justified for it's own reasons, and for any but hunts
looking into why the behavior changed to wind up here instead
of in the code that will follow that computes bprm->cred
from the final bprm->file.
This small logic bug appears to have existed since the code
started clearing dangerous personality bits.
History Tree: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Fixes: 1bb0fa189c6a ("[PATCH] NX: clean up legacy binary support")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
net/mlx5: Add ability to read and write ECE options
net/mlx5: Add support for RDMA TX FT headers modifying
net/mlx5: Move iseg access helper routines close to mlx5_core driver
net/mlx5: Cleanup mlx5_ifc_fte_match_set_misc2_bits
net/mlx5: Add support in forward to namespace
{IB/net}/mlx5: Simplify don't trap code
net/mlx5: Replace zero-length array with flexible-array
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
No users left.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Most of blk-mq drivers depend on managed IRQ's auto-affinity to setup
up queue mapping. Thomas mentioned the following point[1]:
"That was the constraint of managed interrupts from the very beginning:
The driver/subsystem has to quiesce the interrupt line and the associated
queue _before_ it gets shutdown in CPU unplug and not fiddle with it
until it's restarted by the core when the CPU is plugged in again."
However, current blk-mq implementation doesn't quiesce hw queue before
the last CPU in the hctx is shutdown. Even worse, CPUHP_BLK_MQ_DEAD is a
cpuhp state handled after the CPU is down, so there isn't any chance to
quiesce the hctx before shutting down the CPU.
Add new CPUHP_AP_BLK_MQ_ONLINE state to stop allocating from blk-mq hctxs
where the last CPU goes away, and wait for completion of in-flight
requests. This guarantees that there is no inflight I/O before shutting
down the managed IRQ.
Add a BLK_MQ_F_STACKING and set it for dm-rq and loop, so we don't need
to wait for completion of in-flight requests from these drivers to avoid
a potential dead-lock. It is safe to do this for stacking drivers as those
do not use interrupts at all and their I/O completions are triggered by
underlying devices I/O completion.
[1] https://lore.kernel.org/linux-block/alpine.DEB.2.21.1904051331270.1802@nanos.tec.linutronix.de/
[hch: different retry mechanism, merged two patches, minor cleanups]
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
None of the I/O schedulers actually needs it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Drivers may need to bypass error injection for error recovery. Rename
__blk_mq_complete_request() to blk_mq_force_complete_rq() and export
that function so drivers may skip potential fake timeouts after they've
reclaimed lost requests.
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The name of pm_runtime_callbacks_present() is confusing, because
it suggests that the device has PM-runtime callbacks if 'true' is
returned by that function, but in fact that may not be the case,
so replace it with pm_runtime_has_no_callbacks() which is not
ambiguous.
No functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Hi!
This patchset is another attempt to fix the regulator coupling on
Exynos5800/5422 SoCs. Here are links to the previous attempts:
https://lore.kernel.org/linux-samsung-soc/20191008101709.qVNy8eijBi0LynOteWFMnTg4GUwKG599n6OyYoX1Abs@z/https://lore.kernel.org/lkml/20191017102758.8104-1-m.szyprowski@samsung.com/https://lore.kernel.org/linux-pm/cover.1589528491.git.viresh.kumar@linaro.org/https://lore.kernel.org/linux-pm/20200528131130.17984-1-m.szyprowski@samsung.com/
The problem is with "vdd_int" regulator coupled with "vdd_arm" on Odroid
XU3/XU4 boards family. "vdd_arm" is handled by CPUfreq. "vdd_int" is
handled by devfreq. CPUfreq initialized quite early during boot and it
starts changing OPPs and "vdd_arm" value. Sometimes CPU activity during
boot goes down and some low-frequency OPPs are selected, what in turn
causes lowering "vdd_arm". This happens before devfreq applies its
requirements on "vdd_int". Regulator balancing code reduces "vdd_arm"
voltage value, what in turn causes lowering "vdd_int" value to the lowest
possible value. This is much below the operation point of the wcore bus,
which still runs at the highest frequency.
The issue was hard to notice because in the most cases the board managed
to boot properly, even when the regulator was set to lowest value allowed
by the regulator constraints. However, it caused some random issues,
which can be observed as "Unhandled prefetch abort" or low USB stability.
Adding more and more special cases to the generic code has been rejected,
so the only way to ensure the desired behavior on Exynos5800-based SoCs
is to make a custom regulator coupler driver.
Best regards,
Marek Szyprowski
Patch summary:
Marek Szyprowski (2):
regulator: extract voltage balancing code to separate function
soc: samsung: Add simple voltage coupler for Exynos5800
arch/arm/mach-exynos/Kconfig | 1 +
drivers/regulator/core.c | 49 ++++++++-------
drivers/soc/samsung/Kconfig | 3 +
drivers/soc/samsung/Makefile | 1 +
.../soc/samsung/exynos-regulator-coupler.c | 59 +++++++++++++++++++
include/linux/regulator/coupler.h | 8 +++
6 files changed, 101 insertions(+), 20 deletions(-)
create mode 100644 drivers/soc/samsung/exynos-regulator-coupler.c
--
2.17.1
base-commit: 8f3d9f3542
Move the coupled regulators voltage balancing code to the separate
function and allow to call it from the custom regulator couplers.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20200529124940.10675-2-m.szyprowski@samsung.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Sub-devices of a real DMA device might exist on a separate segment than
the real DMA device and its IOMMU. These devices should still have a
valid device_domain_info, but the current dma alias model won't
allocate info for the subdevice.
This patch adds a segment member to struct device_domain_info and uses
the sub-device's BDF so that these sub-devices won't alias to other
devices.
Fixes: 2b0140c696 ("iommu/vt-d: Use pci_real_dma_dev() for mapping")
Cc: stable@vger.kernel.org # v5.6+
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20200527165617.297470-3-jonathan.derrick@intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Bartosz Golaszewski <bgolaszewski@baylibre.com>:
From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
I noticed that oftentimes I use regmap_update_bits() for simple bit
setting or clearing. In this case the fourth argument is superfluous as
it's always 0 or equal to the mask argument.
This series proposes to add simple bit operations for setting, clearing
and testing specific bits with regmap.
The second patch uses all three in a driver that got recently picked into
the net-next tree.
The patches obviously target different trees so - if you're ok with
the change itself - I propose you pick the first one into your regmap
tree for v5.8 and then I'll resend the second patch to add the first
user for these macros for v5.9.
v1 -> v2:
- convert the new macros to static inline functions
v2 -> v3:
- drop unneeded ternary operator
Bartosz Golaszewski (2):
regmap: provide helpers for simple bit operations
net: ethernet: mtk-star-emac: use regmap bitops
drivers/base/regmap/regmap.c | 22 +++++
drivers/net/ethernet/mediatek/mtk_star_emac.c | 80 ++++++++-----------
include/linux/regmap.h | 36 +++++++++
3 files changed, 93 insertions(+), 45 deletions(-)
base-commit: 8f3d9f3542
--
2.26.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.orghttp://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Looking at the Felix and Ocelot drivers, Maxim asked if it would be
possible to use them as a base for a new driver for the switch inside
NXP T1040. Turns out, it is! The result is a driver eerily similar to
Felix.
The biggest challenge seems to be getting register read/write API
generic enough to cover such wild bitfield variations between hardware
generations. There is a patch on the regmap core which I would like to
get in through the networking subsystem, if possible (and if Mark is
ok), since it's a trivial addition.
Maxim Kochetkov (4):
soc/mscc: ocelot: add MII registers description
net: mscc: ocelot: convert SYS_PAUSE_CFG register access to regfield
net: mscc: ocelot: extend watermark encoding function
net: dsa: ocelot: introduce driver for Seville VSC9953 switch
Vladimir Oltean (7):
regmap: add helper for per-port regfield initialization
net: mscc: ocelot: unexport ocelot_probe_port
net: mscc: ocelot: convert port registers to regmap
net: mscc: ocelot: convert QSYS_SWITCH_PORT_MODE and SYS_PORT_MODE to
regfields
net: dsa: ocelot: create a template for the DSA tags on xmit
net: mscc: ocelot: split writes to pause frame enable bit and to
thresholds
net: mscc: ocelot: disable flow control on NPI interface
drivers/net/dsa/ocelot/Kconfig | 12 +
drivers/net/dsa/ocelot/Makefile | 6 +
drivers/net/dsa/ocelot/felix.c | 49 +-
drivers/net/dsa/ocelot/felix_vsc9959.c | 72 +-
drivers/net/dsa/ocelot/seville.c | 742 +++++++++++++++
drivers/net/dsa/ocelot/seville.h | 50 +
drivers/net/dsa/ocelot/seville_vsc9953.c | 1064 ++++++++++++++++++++++
drivers/net/ethernet/mscc/ocelot.c | 87 +-
drivers/net/ethernet/mscc/ocelot.h | 9 +-
drivers/net/ethernet/mscc/ocelot_board.c | 21 +-
drivers/net/ethernet/mscc/ocelot_io.c | 18 +-
drivers/net/ethernet/mscc/ocelot_regs.c | 57 ++
include/linux/regmap.h | 8 +
include/soc/mscc/ocelot.h | 68 +-
include/soc/mscc/ocelot_dev.h | 78 --
include/soc/mscc/ocelot_qsys.h | 13 -
include/soc/mscc/ocelot_sys.h | 23 -
net/dsa/tag_ocelot.c | 21 +-
18 files changed, 2196 insertions(+), 202 deletions(-)
create mode 100644 drivers/net/dsa/ocelot/seville.c
create mode 100644 drivers/net/dsa/ocelot/seville.h
create mode 100644 drivers/net/dsa/ocelot/seville_vsc9953.c
base-commit: 8f3d9f3542
--
2.25.1
In many instances regmap_update_bits() is used for simple bit setting
and clearing. In these cases the last argument is redundant and we can
hide it with a static inline function.
This adds three new helpers for simple bit operations: set_bits,
clear_bits and test_bits (the last one defined as a regular function).
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20200528154503.26304-2-brgl@bgdev.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
After binding a device to an mm, device drivers currently need to
register a mm_exit handler. This function is called when the mm exits,
to gracefully stop DMA targeting the address space and flush page faults
to the IOMMU.
This is deemed too complex for the MMU release() notifier, which may be
triggered by any mmput() invocation, from about 120 callsites [1]. The
upcoming SVA module has an example of such complexity: the I/O Page
Fault handler would need to call mmput_async() instead of mmput() after
handling an IOPF, to avoid triggering the release() notifier which would
in turn drain the IOPF queue and lock up.
Another concern is the DMA stop function taking too long, up to several
minutes [2]. For some mmput() callers this may disturb other users. For
example, if the OOM killer picks the mm bound to a device as the victim
and that mm's memory is locked, if the release() takes too long, it
might choose additional innocent victims to kill.
To simplify the MMU release notifier, don't forward the notification to
device drivers. Since they don't stop DMA on mm exit anymore, the PASID
lifetime is extended:
(1) The device driver calls bind(). A PASID is allocated.
Here any DMA fault is handled by mm, and on error we don't print
anything to dmesg. Userspace can easily trigger errors by issuing DMA
on unmapped buffers.
(2) exit_mmap(), for example the process took a SIGKILL. This step
doesn't happen during normal operations. Remove the pgd from the
PASID table, since the page tables are about to be freed. Invalidate
the IOTLBs.
Here the device may still perform DMA on the address space. Incoming
transactions are aborted but faults aren't printed out. ATS
Translation Requests return Successful Translation Completions with
R=W=0. PRI Page Requests return with Invalid Request.
(3) The device driver stops DMA, possibly following release of a fd, and
calls unbind(). PASID table is cleared, IOTLB invalidated if
necessary. The page fault queues are drained, and the PASID is
freed.
If DMA for that PASID is still running here, something went seriously
wrong and errors should be reported.
For now remove iommu_sva_ops entirely. We might need to re-introduce
them at some point, for example to notify device drivers of unhandled
IOPF.
[1] https://lore.kernel.org/linux-iommu/20200306174239.GM31668@ziepe.ca/
[2] https://lore.kernel.org/linux-iommu/4d68da96-0ad5-b412-5987-2f7a6aa796c3@amd.com/
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Acked-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20200423125329.782066-3-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
The mm_exit() op will be removed from the SVA API. When a process dies
and its mm goes away, the IOMMU driver won't notify device drivers
anymore. Drivers should expect to handle a lot more aborted DMA. On the
upside, it does greatly simplify the queue management.
The uacce_mm struct, that tracks all queues bound to an mm, was only
used by the mm_exit() callback. Remove it.
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Acked-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Link: https://lore.kernel.org/r/20200423125329.782066-2-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Similar to the standalone regfields, add an initializer for the users
who need to set .id_size and .id_offset in order to use the
regmap_fields_update_bits_base API.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20200527234113.2491988-2-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
In simple cases we can instantiate SPD EEPROMs on the SMBus
automatically. Start with just DDR2, DDR3 and DDR4 on x86 for now,
and only for systems with no more than 4 memory slots. These
limitations may be lifted later.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
[wsa: minor change for new API]
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Commit e8759ad17d ("serial: uapi: Add support for bus termination")
introduced the ability to enable rs485 bus termination from user space.
So far the feature is only used by a single driver, 8250_exar.c, using a
hardcoded GPIO pin specific to Siemens IOT2040 products.
Provide for a more generic solution by allowing specification of an
rs485 bus termination GPIO pin in the device tree: Amend the serial
core to retrieve the GPIO from the device tree (or ACPI table) and amend
the default ->rs485_config() callback for 8250 drivers to change the
GPIO on request from user space.
Perhaps 8250_exar.c can be converted to the generic approach in a
follow-up patch.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Link: https://lore.kernel.org/r/94c6c800d1ca9fa04766dd1d43a8272c5ad4bedd.1589811297.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix ordering of SDIO IDs to conform to the comment above, which says vendor
first, device next.
Signed-off-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20200522144412.19712-12-pali@kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
All macro names for SDIO device IDs are prefixed by vendor name to which
device ID belongs. So for consistency add Broadcom string vendor prefix to
all Cypress macro names as they belong to SDIO Broadcom vendor ID.
Change also Cypress 43012 value from decimal do hexadecimal notation to be
consistent with all other values.
Signed-off-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20200522144412.19712-11-pali@kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Also replace generic MANUFACTURER macros by proper SDIO IDs macros.
Checks for device IDs are slightly modified to use SDIO device IDs.
This allows removal of all custom MANUFACTURER macros from ath10k.
Signed-off-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20200522144412.19712-9-pali@kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Also replace generic MANUFACTURER macros by proper SDIO IDs macros.
Check for "AR6003 or later" is slightly modified to use SDIO device IDs.
This allows removal of all custom MANUFACTURER macros from ath6kl.
Signed-off-by: Pali Rohár <pali@kernel.org>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200522144412.19712-8-pali@kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Add _WLAN suffix to macro names for consistency with other Marvell macros.
These IDs represents wlan function of combo bt/wlan cards. Other functions
of these cards have different IDs.
Signed-off-by: Pali Rohár <pali@kernel.org>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200522144412.19712-4-pali@kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Ganapathi Bhat <ganapathi.bhat@nxp.com>
Expose the bandwidth information as well via debugfs.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
The OPP bindings now support bandwidth values, so add support to parse it
from device tree and store it into the new dev_pm_opp_icc_bw struct, which
is part of the dev_pm_opp.
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
[ Viresh: Create _read_bw() and use it, renamed _of_find_icc_paths() to
dev_pm_opp_of_find_icc_paths(), exported it and made opp_table
argument optional. Also drop the depends on from Kconfig. ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Recent change in virtio_net_hdr_to_skb() broke some packetdrill tests.
When --mss=XXX option is set, packetdrill always provide gso_type & gso_size
for its inbound packets, regardless of packet size.
if (packet->tcp && packet->mss) {
if (packet->ipv4)
gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
else
gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
gso.gso_size = packet->mss;
}
Since many other programs could do the same, relax virtio_net_hdr_to_skb()
to no longer return an error, but instead ignore gso settings.
This keeps Willem intent to make sure no malicious packet could
reach gso stack.
Note that TCP stack has a special logic in tcp_set_skb_tso_segs()
to clear gso_size for small packets.
Fixes: 6dd912f826 ("net: check untrusted gso_size at kernel entry")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
gss_mech_register() calls svcauth_gss_register_pseudoflavor() for each
flavour, but gss_mech_unregister() does not call auth_domain_put().
This is unbalanced and makes it impossible to reload the module.
Change svcauth_gss_register_pseudoflavor() to return the registered
auth_domain, and save it for later release.
Cc: stable@vger.kernel.org (v2.6.12+)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206651
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Added a check such that only singleton IOMMU groups can pin pages.
>From the point when vendor driver pins any pages, consider IOMMU group
dirty page scope to be limited to pinned pages.
To optimize to avoid walking list often, added flag
pinned_page_dirty_scope to indicate if all of the vfio_groups for each
vfio_domain in the domain_list dirty page scope is limited to pinned
pages. This flag is updated on first pinned pages request for that IOMMU
group and on attaching/detaching group.
Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
With 'commit 461c1a7d47 ("gpiolib: override irq_enable/disable")' gpiolib
overrides irqchip's irq_enable and irq_disable callbacks. If irq_disable
callback is implemented then genirq takes unlazy path to disable irq.
Underlying irqchip may not want to implement irq_disable callback to lazy
disable irq when client drivers invokes disable_irq(). By overriding
irq_disable callback, gpiolib ends up always unlazy disabling IRQ.
Allow gpiolib to lazy disable IRQs by overriding irq_disable callback only
if irqchip implemented irq_disable. In cases where irq_disable is not
implemented irq_mask is overridden. Similarly override irq_enable callback
only if irqchip implemented irq_enable otherwise irq_unmask is overridden.
Fixes: 461c1a7d47 ("gpiolib: override irq_enable/disable")
Signed-off-by: Maulik Shah <mkshah@codeaurora.org>
Tested-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Link: https://lore.kernel.org/r/1590253873-11556-2-git-send-email-mkshah@codeaurora.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Replace superfluous VM_BUG_ON() with comment about correct usage.
Technically reverts commit 1d148e218a ("mm: add VM_BUG_ON_PAGE() to
page_mapcount()"), but context lines have changed.
Function isolate_migratepages_block() runs some checks out of lru_lock
when choose pages for migration. After checking PageLRU() it checks
extra page references by comparing page_count() and page_mapcount().
Between these two checks page could be removed from lru, freed and taken
by slab.
As a result this race triggers VM_BUG_ON(PageSlab()) in page_mapcount().
Race window is tiny. For certain workload this happens around once a
year.
page:ffffea0105ca9380 count:1 mapcount:0 mapping:ffff88ff7712c180 index:0x0 compound_mapcount: 0
flags: 0x500000000008100(slab|head)
raw: 0500000000008100 dead000000000100 dead000000000200 ffff88ff7712c180
raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000
page dumped because: VM_BUG_ON_PAGE(PageSlab(page))
------------[ cut here ]------------
kernel BUG at ./include/linux/mm.h:628!
invalid opcode: 0000 [#1] SMP NOPTI
CPU: 77 PID: 504 Comm: kcompactd1 Tainted: G W 4.19.109-27 #1
Hardware name: Yandex T175-N41-Y3N/MY81-EX0-Y3N, BIOS R05 06/20/2019
RIP: 0010:isolate_migratepages_block+0x986/0x9b0
The code in isolate_migratepages_block() was added in commit
119d6d59dc ("mm, compaction: avoid isolating pinned pages") before
adding VM_BUG_ON into page_mapcount().
This race has been predicted in 2015 by Vlastimil Babka (see link
below).
[akpm@linux-foundation.org: comment tweaks, per Hugh]
Fixes: 1d148e218a ("mm: add VM_BUG_ON_PAGE() to page_mapcount()")
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/159032779896.957378.7852761411265662220.stgit@buzz
Link: https://lore.kernel.org/lkml/557710E1.6060103@suse.cz/
Link: https://lore.kernel.org/linux-mm/158937872515.474360.5066096871639561424.stgit@buzz/T/ (v1)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a helper to directly set the TCP_KEEPCNT sockopt from kernel space
without going through a fake uaccess.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the TCP_KEEPINTVL sockopt from kernel space
without going through a fake uaccess.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the TCP_KEEP_IDLE sockopt from kernel
space without going through a fake uaccess.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the TCP_USER_TIMEOUT sockopt from kernel
space without going through a fake uaccess.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the TCP_SYNCNT sockopt from kernel space
without going through a fake uaccess.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the TCP_QUICKACK sockopt from kernel space
without going through a fake uaccess. Cleanup the callers to avoid
pointless wrappers now that this is a simple function call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the TCP_NODELAY sockopt from kernel space
without going through a fake uaccess. Cleanup the callers to avoid
pointless wrappers now that this is a simple function call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the TCP_CORK sockopt from kernel space
without going through a fake uaccess. Cleanup the callers to avoid
pointless wrappers now that this is a simple function call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some battery fuel gauges know when the battery needs to
be recalibrated before providing usable values. This
should be reported via the health property.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Some smart batteries store their manufacture date, which is
useful to identify the battery and/or to know about the cell
quality.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
