Commit fee7e49d4514 ("mm: propagate error from stack expansion even for
guard page") made sure that we return the error properly for stack
growth conditions. It also theorized that counting the guard page
towards the stack limit might break something, but also said "Let's see
if anybody notices".
Somebody did notice. Apparently android-x86 sets the stack limit very
close to the limit indeed, and including the guard page in the rlimit
check causes the android 'zygote' process problems.
So this adds the (fairly trivial) code to make the stack rlimit check be
against the actual real stack size, rather than the size of the vma that
includes the guard page.
Jay Foad reports that the address sanitizer test (asan) sometimes gets
confused by a stack pointer that ends up being outside the stack vma
that is reported by /proc/maps.
This happens due to an interaction between RLIMIT_STACK and the guard
page: when we do the guard page check, we ignore the potential error
from the stack expansion, which effectively results in a missing guard
page, since the expected stack expansion won't have been done.
And since /proc/maps explicitly ignores the guard page (commit d7824370e263: "mm: fix up some user-visible effects of the stack guard
page"), the stack pointer ends up being outside the reported stack area.
This is the minimal patch: it just propagates the error. It also
effectively makes the guard page part of the stack limit, which in turn
measn that the actual real stack is one page less than the stack limit.
Let's see if anybody notices. We could teach acct_stack_growth() to
allow an extra page for a grow-up/grow-down stack in the rlimit test,
but I don't want to add more complexity if it isn't needed.
Charles Shirron and Paul Cassella from Cray Inc have reported kswapd
stuck in a busy loop with nothing left to balance, but
kswapd_try_to_sleep() failing to sleep. Their analysis found the cause
to be a combination of several factors:
1. A process is waiting in throttle_direct_reclaim() on pgdat->pfmemalloc_wait
2. The process has been killed (by OOM in this case), but has not yet been
scheduled to remove itself from the waitqueue and die.
3. kswapd checks for throttled processes in prepare_kswapd_sleep():
if (waitqueue_active(&pgdat->pfmemalloc_wait)) {
wake_up(&pgdat->pfmemalloc_wait);
return false; // kswapd will not go to sleep
}
However, for a process that was already killed, wake_up() does not remove
the process from the waitqueue, since try_to_wake_up() checks its state
first and returns false when the process is no longer waiting.
4. kswapd is running on the same CPU as the only CPU that the process is
allowed to run on (through cpus_allowed, or possibly single-cpu system).
5. CONFIG_PREEMPT_NONE=y kernel is used. If there's nothing to balance, kswapd
encounters no voluntary preemption points and repeatedly fails
prepare_kswapd_sleep(), blocking the process from running and removing
itself from the waitqueue, which would let kswapd sleep.
So, the source of the problem is that we prevent kswapd from going to
sleep until there are processes waiting on the pfmemalloc_wait queue,
and a process waiting on a queue is guaranteed to be removed from the
queue only when it gets scheduled. This was done to make sure that no
process is left sleeping on pfmemalloc_wait when kswapd itself goes to
sleep.
However, it isn't necessary to postpone kswapd sleep until the
pfmemalloc_wait queue actually empties. To prevent processes from being
left sleeping, it's actually enough to guarantee that all processes
waiting on pfmemalloc_wait queue have been woken up by the time we put
kswapd to sleep.
This patch therefore fixes this issue by substituting 'wake_up' with
'wake_up_all' and removing 'return false' in the code snippet from
prepare_kswapd_sleep() above. Note that if any process puts itself in
the queue after this waitqueue_active() check, or after the wake up
itself, it means that the process will also wake up kswapd - and since
we are under prepare_to_wait(), the wake up won't be missed. Also we
update the comment prepare_kswapd_sleep() to hopefully more clearly
describe the races it is preventing.
Fixes: 5515061d22f0 ("mm: throttle direct reclaimers if PF_MEMALLOC reserves are low and swap is backed by network storage") Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tejun, while reviewing the code, spotted the following race condition
between the dirtying and truncation of a page:
__set_page_dirty_nobuffers() __delete_from_page_cache()
if (TestSetPageDirty(page))
page->mapping = NULL
if (PageDirty())
dec_zone_page_state(page, NR_FILE_DIRTY);
dec_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE);
if (page->mapping)
account_page_dirtied(page)
__inc_zone_page_state(page, NR_FILE_DIRTY);
__inc_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE);
which results in an imbalance of NR_FILE_DIRTY and BDI_RECLAIMABLE.
Dirtiers usually lock out truncation, either by holding the page lock
directly, or in case of zap_pte_range(), by pinning the mapcount with
the page table lock held. The notable exception to this rule, though,
is do_wp_page(), for which this race exists. However, do_wp_page()
already waits for a locked page to unlock before setting the dirty bit,
in order to prevent a race where clear_page_dirty() misses the page bit
in the presence of dirty ptes. Upgrade that wait to a fully locked
set_page_dirty() to also cover the situation explained above.
Afterwards, the code in set_page_dirty() dealing with a truncation race
is no longer needed. Remove it.
Reported-by: Tejun Heo <tj@kernel.org> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
wait_consider_task() checks EXIT_ZOMBIE after EXIT_DEAD/EXIT_TRACE and
both checks can fail if we race with EXIT_ZOMBIE -> EXIT_DEAD/EXIT_TRACE
change in between, gcc needs to reload p->exit_state after
security_task_wait(). In this case ->notask_error will be wrongly
cleared and do_wait() can hang forever if it was the last eligible
child.
Many thanks to Arne who carefully investigated the problem.
Note: this bug is very old but it was pure theoretical until commit b3ab03160dfa ("wait: completely ignore the EXIT_DEAD tasks"). Before
this commit "-O2" was probably enough to guarantee that compiler won't
read ->exit_state twice.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Arne Goedeke <el@laramies.com> Tested-by: Arne Goedeke <el@laramies.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sleep in atomic context happened on Trats2 board after inserting or
removing SD card because mmc_gpio_get_cd() was called under spin lock.
Fix this by moving card detection earlier, before acquiring spin lock.
The mmc_gpio_get_cd() call does not have to be protected by spin lock
because it does not access any sdhci internal data.
The sdhci_do_get_cd() call access host flags (SDHCI_DEVICE_DEAD). After
moving it out side of spin lock it could theoretically race with driver
removal but still there is no actual protection against manual card
eject.
Dmesg after inserting SD card:
[ 41.663414] BUG: sleeping function called from invalid context at drivers/gpio/gpiolib.c:1511
[ 41.670469] in_atomic(): 1, irqs_disabled(): 128, pid: 30, name: kworker/u8:1
[ 41.677580] INFO: lockdep is turned off.
[ 41.681486] irq event stamp: 61972
[ 41.684872] hardirqs last enabled at (61971): [<c0490ee0>] _raw_spin_unlock_irq+0x24/0x5c
[ 41.693118] hardirqs last disabled at (61972): [<c04907ac>] _raw_spin_lock_irq+0x18/0x54
[ 41.701190] softirqs last enabled at (61648): [<c0026fd4>] __do_softirq+0x234/0x2c8
[ 41.708914] softirqs last disabled at (61631): [<c00273a0>] irq_exit+0xd0/0x114
[ 41.716206] Preemption disabled at:[< (null)>] (null)
[ 41.721500]
[ 41.722985] CPU: 3 PID: 30 Comm: kworker/u8:1 Tainted: G W 3.18.0-rc5-next-20141121 #883
[ 41.732111] Workqueue: kmmcd mmc_rescan
[ 41.735945] [<c0014d2c>] (unwind_backtrace) from [<c0011c80>] (show_stack+0x10/0x14)
[ 41.743661] [<c0011c80>] (show_stack) from [<c0489d14>] (dump_stack+0x70/0xbc)
[ 41.750867] [<c0489d14>] (dump_stack) from [<c0228b74>] (gpiod_get_raw_value_cansleep+0x18/0x30)
[ 41.759628] [<c0228b74>] (gpiod_get_raw_value_cansleep) from [<c03646e8>] (mmc_gpio_get_cd+0x38/0x58)
[ 41.768821] [<c03646e8>] (mmc_gpio_get_cd) from [<c036d378>] (sdhci_request+0x50/0x1a4)
[ 41.776808] [<c036d378>] (sdhci_request) from [<c0357934>] (mmc_start_request+0x138/0x268)
[ 41.785051] [<c0357934>] (mmc_start_request) from [<c0357cc8>] (mmc_wait_for_req+0x58/0x1a0)
[ 41.793469] [<c0357cc8>] (mmc_wait_for_req) from [<c0357e68>] (mmc_wait_for_cmd+0x58/0x78)
[ 41.801714] [<c0357e68>] (mmc_wait_for_cmd) from [<c0361c00>] (mmc_io_rw_direct_host+0x98/0x124)
[ 41.810480] [<c0361c00>] (mmc_io_rw_direct_host) from [<c03620f8>] (sdio_reset+0x2c/0x64)
[ 41.818641] [<c03620f8>] (sdio_reset) from [<c035a3d8>] (mmc_rescan+0x254/0x2e4)
[ 41.826028] [<c035a3d8>] (mmc_rescan) from [<c003a0e0>] (process_one_work+0x180/0x3f4)
[ 41.833920] [<c003a0e0>] (process_one_work) from [<c003a3bc>] (worker_thread+0x34/0x4b0)
[ 41.841991] [<c003a3bc>] (worker_thread) from [<c003fed8>] (kthread+0xe4/0x104)
[ 41.849285] [<c003fed8>] (kthread) from [<c000f268>] (ret_from_fork+0x14/0x2c)
[ 42.038276] mmc0: new high speed SDHC card at address 1234
Invalid buck4 configuration for linear mapping of voltage in S2MPS14
regulators caused boot failure on Gear 2 (dw_mmc-exynos):
[ 3.569137] EXT4-fs (mmcblk0p15): mounted filesystem with ordered data mode. Opts: (null)
[ 3.571716] VFS: Mounted root (ext4 filesystem) readonly on device 179:15.
[ 3.629842] mmcblk0: error -110 sending status command, retrying
[ 3.630244] mmcblk0: error -110 sending status command, retrying
[ 3.636292] mmcblk0: error -110 sending status command, aborting
Buck4 voltage regulator has different minimal voltage value than other
bucks. Commit merging multiple regulator description macros caused to
use linear_min_sel from buck[1235] regulators as value for buck4. This
lead to lower voltage of buck4 than required.
Output of the buck4 is used internally as power source for
LDO{3,4,7,11,19,20,21,23}. On Gear 2 board LDO11 is used as MMC
regulator (V_EMMC_1.8V).
Fixes: 5a867cf28893 ("regulator: s2mps11: Optimize the regulator description macro") Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nouveau userspace back at 1.0.1 used to call the X server
DRIOpenDRMMaster interface even for DRI2 (doh!), this attempts
to map the sarea and fails if it can't.
SH-MSIOF driver is enabled autosuspend API of spi framework.
But autosuspend framework doesn't work during initializing.
So runtime PM lock is added in SH-MSIOF driver initializing.
Fixes: e2a0ba547ba31c (spi: sh-msiof: Convert to spi core auto_runtime_pm framework) Signed-off-by: Hisashi Nakamura <hisashi.nakamura.ak@renesas.com> Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linus reported perf report command being interrupted due to processing
of 'out of order' event, with following error:
Timestamp below last timeslice flush
0x5733a8 [0x28]: failed to process type: 3
I could reproduce the issue and in my case it was caused by one CPU
(mmap) being behind during record and userspace mmap reader seeing the
data after other CPUs data were already stored.
This is expected under some circumstances because we need to limit the
number of events that we queue for reordering when we receive a
PERF_RECORD_FINISHED_ROUND or when we force flush due to memory
pressure.
forces group members to change their event->cpu,
if the currently-opened-event's PMU changed the cpu
and there is a group move.
Above behaviour causes problem for breakpoint events,
which uses event->cpu to touch cpu specific data for
breakpoints accounting. By changing event->cpu, some
breakpoints slots were wrongly accounted for given
cpu.
Vinces's perf fuzzer hit this issue and caused following
WARN on my setup:
WARNING: CPU: 0 PID: 20214 at arch/x86/kernel/hw_breakpoint.c:119 arch_install_hw_breakpoint+0x142/0x150()
Can't find any breakpoint slot
[...]
This patch changes the group moving code to keep the event's
original cpu.
The uncore_collect_events functions assumes that event group
might contain only uncore events which is wrong, because it
might contain any type of events.
This bug leads to uncore framework touching 'not' uncore events,
which could end up all sorts of bugs.
One was triggered by Vince's perf fuzzer, when the uncore code
touched breakpoint event private event space as if it was uncore
event and caused BUG:
The code in uncore_assign_events() function was looking for
event->hw.idx data while the event was initialized as a
breakpoint with different members in event->hw union.
This patch forces uncore_collect_events() to collect only uncore
events.
It turns out that the p54 and cw2100 drivers assume that there's
tailroom even when they don't say they really need it. However,
there's currently no way for them to explicitly say they do need
it, so for now revert this.
This fixes https://bugzilla.kernel.org/show_bug.cgi?id=90331.
Fixes: ca34e3b5c808 ("mac80211: Fix accounting of the tailroom-needed counter") Reported-by: Christopher Chavez <chrischavez@gmx.us> Bisected-by: Larry Finger <Larry.Finger@lwfinger.net> Debugged-by: Christian Lamparter <chunkeey@googlemail.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 1d52c78afbb (Btrfs: try not to ENOSPC on log replay) added a
check to skip delayed inode updates during log replay because it
confuses the enospc code. But the delayed processing will end up
ignoring delayed refs from log replay because the inode itself wasn't
put through the delayed code.
This can end up triggering a warning at commit time:
WARNING: CPU: 2 PID: 778 at fs/btrfs/delayed-inode.c:1410 btrfs_assert_delayed_root_empty+0x32/0x34()
Which is repeated for each commit because we never process the delayed
inode ref update.
The fix used here is to change btrfs_delayed_delete_inode_ref to return
an error if we're currently in log replay. The caller will do the ref
deletion immediately and everything will work properly.
Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The "by8" counter mode optimization is broken for 128 bit keys with
input data longer than 128 bytes. It uses the wrong key material for
en- and decryption.
The key registers xkey0, xkey4, xkey8 and xkey12 need to be preserved
in case we're handling more than 128 bytes of input data -- they won't
get reloaded after the initial load. They must therefore be (a) loaded
on the first iteration and (b) be preserved for the latter ones. The
implementation for 128 bit keys does not comply with (a) nor (b).
Fix this by bringing the implementation back to its original source
and correctly load the key registers and preserve their values by
*not* re-using the registers for other purposes.
Kudos to James for reporting the issue and providing a test case
showing the discrepancies.
Reported-by: James Yonan <james@openvpn.net> Cc: Chandramouli Narayanan <mouli@linux.intel.com> Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The early ioremap support introduced by patch bf4b558eba92
("arm64: add early_ioremap support") failed to add a call to
early_ioremap_reset() at an appropriate time. Without this call,
invocations of early_ioremap etc. that are done too late will go
unnoticed and may cause corruption.
This is exactly what happened when the first user of this feature
was added in patch f84d02755f5a ("arm64: add EFI runtime services").
The early mapping of the EFI memory map is unmapped during an early
initcall, at which time the early ioremap support is long gone.
Fix by adding the missing call to early_ioremap_reset() to
setup_arch(), and move the offending early_memunmap() to right after
the point where the early mapping of the EFI memory map is last used.
On arm64 the TTBR0_EL1 register is set to either the reserved TTBR0
page tables on boot or to the active_mm mappings belonging to user space
processes, it must never be set to swapper_pg_dir page tables mappings.
When a CPU is booted its active_mm is set to init_mm even though its
TTBR0_EL1 points at the reserved TTBR0 page mappings. This implies
that when __cpu_suspend is triggered the active_mm can point at
init_mm even if the current TTBR0_EL1 register contains the reserved
TTBR0_EL1 mappings.
Therefore, the mm save and restore executed in __cpu_suspend might
turn out to be erroneous in that, if the current->active_mm corresponds
to init_mm, on resume from low power it ends up restoring in the
TTBR0_EL1 the init_mm mappings that are global and can cause speculation
of TLB entries which end up being propagated to user space.
This patch fixes the issue by checking the active_mm pointer before
restoring the TTBR0 mappings. If the current active_mm == &init_mm,
the code sets the TTBR0_EL1 to the reserved TTBR0 mapping instead of
switching back to the active_mm, which is the expected behaviour
corresponding to the TTBR0_EL1 settings when __cpu_suspend was entered.
The function cpu_resume currently lives in the .data section.
There's no reason for it to be there since we can use relative
instructions without a problem. Move a few cpu_resume data
structures out of the assembly file so the .data annotation
can be dropped completely and cpu_resume ends up in the read
only text section.
Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Tested-by: Kees Cook <keescook@chromium.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Protocol v7 uses the middle / right button bits on clickpads to communicate
"location" information of a 3th touch (and possible 4th) touch on
clickpads.
Specifically when 3 touches are down, if one of the 3 touches is in the
left / right button area, this will get reported in the middle / right
button bits and the touchpad will still send a TWO type packet rather then
a MULTI type packet, so when this happens we must add the finger reported
in the button area to the finger count.
Likewise we must also add fingers reported this way to the finger count
when we get MULTI packets.
BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=86338 Signed-off-by: Hans de Goede <hdegoede@redhat.com> Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The v7 proto differentiates between a primary touch (with high precision)
and a secondary touch (with lower precision). Normally when 2 fingers are
down and one is lifted the still present touch becomes the primary touch,
but some traces have shown that this does not happen always.
This commit deals with this by making alps_get_mt_count() not stop at the
first empty mt slot, and if a touch is present in mt[1] and not mt[0]
moving the data to mt[0] (for input_mt_assign_slots).
BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=86338 Signed-off-by: Hans de Goede <hdegoede@redhat.com> Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
NEW packets are send to indicate a discontinuity in the finger coordinate
reporting. Specifically a finger may have moved from slot 0 to 1 or vice
versa. INPUT_MT_TRACK takes care of this for us.
NEW packets have 3 problems:
1) They do not contain middle / right button info (on non clickpads)
this can be worked around by preserving the old button state
2) They do not contain an accurate fingercount, and they are
typically send when the number of fingers changes. We cannot use
the old finger count as that may mismatch with the amount of
touch coordinates we've available in the NEW packet
3) Their x data for the second touch is inaccurate leading to
a possible jump of the x coordinate by 16 units when the first
non NEW packet comes in
Since problems 2 & 3 cannot be worked around, just ignore them.
BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=86338 Signed-off-by: Hans de Goede <hdegoede@redhat.com> Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If an ACPI device object whose _STA returns 0 (not present and not
functional) has _PR0 or _PS0, its power_manageable flag will be set
and acpi_bus_init_power() will return 0 for it. Consequently, if
such a device object is passed to the ACPI device PM functions, they
will attempt to carry out the requested operation on the device,
although they should not do that for devices that are not present.
To fix that problem make acpi_bus_init_power() return an error code
for devices that are not present which will cause power_manageable to
be cleared for them as appropriate in acpi_bus_get_power_flags().
However, the lists of power resources should not be freed for the
device in that case, so modify acpi_bus_get_power_flags() to keep
those lists even if acpi_bus_init_power() returns an error.
Accordingly, when deciding whether or not the lists of power
resources need to be freed, acpi_free_power_resources_lists()
should check the power.flags.power_resources flag instead of
flags.power_manageable, so make that change too.
Furthermore, if acpi_bus_attach() sees that flags.initialized is
unset for the given device, it should reset the power management
settings of the device and re-initialize them from scratch instead
of relying on the previous settings (the device may have appeared
after being not present previously, for example), so make it use
the 'valid' flag of the D0 power state as the initial value of
flags.power_manageable for it and call acpi_bus_init_power() to
discover its current power state.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Several Samsung laptop models (SAMSUNG 870Z5E/880Z5E/680Z5E and
SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V) do not have a working
native backlight control interface so restore their acpi_videoX
interface.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=84221 Link: https://bugzilla.kernel.org/show_bug.cgi?id=84651
For SAMSUNG 870Z5E/880Z5E/680Z5E: Reported-and-tested-by: Brent Saner <brent.saner@gmail.com> Reported-by: Vitaliy Filippov <vitalif@yourcmc.ru> Reported-by: Laszlo KREKACS <laszlo.krekacs.list@gmail.com>
For SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V: Reported-by: Vladimir Perepechin <vovochka13@gmail.com> Signed-off-by: Aaron Lu <aaron.lu@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A struct xdr_stream at a page boundary might point to the end of one
page or the beginning of the next, but xdr_truncate_encode isn't
prepared to handle the former.
This can cause corruption of NFSv4 READDIR replies in the case that a
readdir entry that would have exceeded the client's dircount/maxcount
limit would have ended exactly on a 4k page boundary. You're more
likely to hit this case on large directories.
Other xdr_truncate_encode callers are probably also affected.
Commit 9fc2105aeaaf ("ARM: 7830/1: delay: don't bother reporting
bogomips in /proc/cpuinfo") breaks audio in python, and probably
elsewhere, with message
Commit 705814b5ea6f ("ARM: OMAP4+: PM: Consolidate OMAP4 PM code to
re-use it for OMAP5")
Moved logic generic for OMAP5+ as part of the init routine by
introducing omap4_pm_init. However, the patch left the powerdomain
initial setup, an unused omap4430 es1.0 check and a spurious log
"Power Management for TI OMAP4." in the original code.
Remove the duplicate code which is already present in omap4_pm_init from
omap4_init_static_deps.
As part of this change, also move the u-boot version print out of the
static dependency function to the omap4_pm_init function.
Fixes: 705814b5ea6f ("ARM: OMAP4+: PM: Consolidate OMAP4 PM code to re-use it for OMAP5") Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The PWM block is required for system clock source so it must be always
enabled. This patch fixes boot issues on SMDK6410 which did not have
the node enabled explicitly for other purposes.
Fixes: eeb93d02 ("clocksource: of: Respect device tree node status") Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
OMAP wdt driver supports only ti,omap3-wdt compatible. In DRA7 dt
wdt compatible property is defined as ti,omap4-wdt by mistake instead of
ti,omap3-wdt. Correcting the typo.
Fixes: 6e58b8f1daaf1a ("ARM: dts: DRA7: Add the dts files for dra7 SoC and dra7-evm board") Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CONFIG_GENERIC_CPUFREQ_CPU0 disappeared with commit bbcf071969b20f
("cpufreq: cpu0: rename driver and internals to 'cpufreq_dt'") and some
defconfigs are still using it instead of the new one.
The lcd0 node for am437x-sk-evm.dts contains bad LCD timings, and while
they seem to work with a quick test, doing for example blank/unblank
will give you a black display.
This patch updates the timings to the 'typical' values from the LCD spec
sheet.
Also, the compatible string is completely bogus, as
"osddisplays,osd057T0559-34ts" is _not_ a 480x272 panel. The panel on
the board is a newhaven one. Update the compatible string to reflect
this. Note that this hasn't caused any issues, as the "panel-dpi"
matches the driver.
Tested-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Caused by a copy & paste error. Note that even with
this bug AM437x SK display still works because GPIO
mux mode is always enabled. It's still wrong to mux
somebody else's pin.
Luckily ball D25 (offset 0x238 - gpio5_8) on AM437x
isn't used for anything.
While at that, also replace a pullup with a pulldown
as that gpio should be normally low, not high.
Acked-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Locklessly doing is_idle_task(rq->curr) is only okay because of
RCU protection. The older variant of the broken code checked
rq->curr == rq->idle instead and therefore didn't need RCU.
Fixes: f6be8af1c95d ("sched: Add new API wake_up_if_idle() to wake up the idle cpu") Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Chuansheng Liu <chuansheng.liu@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/729365dddca178506dfd0a9451006344cd6808bc.1417277372.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The dl_runtime_exceeded() function is supposed to ckeck if
a SCHED_DEADLINE task must be throttled, by checking if its
current runtime is <= 0. However, it also checks if the
scheduling deadline has been missed (the current time is
larger than the current scheduling deadline), further
decreasing the runtime if this happens.
This "double accounting" is wrong:
- In case of partitioned scheduling (or single CPU), this
happens if task_tick_dl() has been called later than expected
(due to small HZ values). In this case, the current runtime is
also negative, and replenish_dl_entity() can take care of the
deadline miss by recharging the current runtime to a value smaller
than dl_runtime
- In case of global scheduling on multiple CPUs, scheduling
deadlines can be missed even if the task did not consume more
runtime than expected, hence penalizing the task is wrong
This patch fix this problem by throttling a SCHED_DEADLINE task
only when its runtime becomes negative, and not modifying the runtime
According to global EDF, tasks should be migrated between runqueues
without checking if their scheduling deadlines and runtimes are valid.
However, SCHED_DEADLINE currently performs such a check:
a migration happens doing:
which ends up calling dequeue_task_dl(), setting the new CPU, and then
calling enqueue_task_dl().
enqueue_task_dl() then calls enqueue_dl_entity(), which calls
update_dl_entity(), which can modify scheduling deadline and runtime,
breaking global EDF scheduling.
As a result, some of the properties of global EDF are not respected:
for example, a taskset {(30, 80), (40, 80), (120, 170)} scheduled on
two cores can have unbounded response times for the third task even
if 30/80+40/80+120/170 = 1.5809 < 2
This can be fixed by invoking update_dl_entity() only in case of
wakeup, or if this is a new SCHED_DEADLINE task.
Same story as in commit 41080b5a2401 ("nfsd race fixes: ext2") (similar
ext2 fix) except that nilfs2 needs to use insert_inode_locked4() instead
of insert_inode_locked() and a bug of a check for dead inodes needs to
be fixed.
If nilfs_iget() is called from nfsd after nilfs_new_inode() calls
insert_inode_locked4(), nilfs_iget() will wait for unlock_new_inode() at
the end of nilfs_mkdir()/nilfs_create()/etc to unlock the inode.
If nilfs_iget() is called before nilfs_new_inode() calls
insert_inode_locked4(), it will create an in-core inode and read its
data from the on-disk inode. But, nilfs_iget() will find i_nlink equals
zero and fail at nilfs_read_inode_common(), which will lead it to call
iget_failed() and cleanly fail.
However, this sanity check doesn't work as expected for reused on-disk
inodes because they leave a non-zero value in i_mode field and it
hinders the test of i_nlink. This patch also fixes the issue by
removing the test on i_mode that nilfs2 doesn't need.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3430LDP has NAND flash with 32 bytes OOB size which is sufficient to hold
BCH8 codes but the small page check introduced in
commit b491da7233d5 ("mtd: nand: omap: clean-up ecc layout for BCH ecc schemes")
considers anything below 64 bytes unsuitable for BCH4/8/16. There is another
bug in that code where it doesn't skip the check for OMAP_ECC_HAM1_CODE_SW.
Get rid of that small page check code as it is insufficient and redundant
because we are checking for OOB available bytes vs ecc layout before calling
nand_scan_tail().
Fixes: b491da7233d5 ("mtd: nand: omap: clean-up ecc layout for BCH ecc schemes") Reported-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Roger Quadros <rogerq@ti.com> Signed-off-by: Brian Norris <computersforpeace@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As stated in a5b7616c5, "mtd: m25p80,spi-nor: Fix module aliases for
m25p80", m25p_ids[] in m25p80.c needs to be kept in sync with
spi_nor_ids[] in spi-nor.c. The change here corrects a misalignment.
(We were missing m25px80 and we had a duplicate w25q128.)
If the firmware has declared more than 8 video output devices, and the
one that control the internal panel's backlight is listed after the
first 8 output devices, the _DOD will not include it due to the current
i915 operation region implementation. As a result, we will not create a
backlight device for it while we should. Solve this problem by special
case the firmware that has 8+ output devices in that if we see such a
firmware, we do not test if the device is in _DOD list. The creation of
the backlight device will also enable the firmware to emit events on
backlight hotkey press when the acpi_osi= cmdline option is specified on
those affected ASUS laptops.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=70241 Reported-and-tested-by: Oleksij Rempel <linux@rempel-privat.de> Reported-and-tested-by: Dmitry Tunin <hanipouspilot@gmail.com> Reported-and-tested-by: Jimbo <jaime.91@hotmail.es> Signed-off-by: Aaron Lu <aaron.lu@intel.com> Acked-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, nfs4_set_delegation takes a reference to an existing
delegation and then checks to see if there is a conflict. If there is
one, then it doesn't release that reference.
Change the code to take the reference after the check and only if there
is no conflict.
Signed-off-by: Jeff Layton <jlayton@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix a bug where nfsd4_encode_components_esc() incorrectly calculates the
length of server array in fs_location4--note that it is a count of the
number of array elements, not a length in bytes.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Fixes: 082d4bd72a45 (nfsd4: "backfill" using write_bytes_to_xdr_buf) Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bugs similar to the one in acbbe6fbb240 (kcmp: fix standard comparison
bug) are in rich supply.
In this variant, the problem is that struct xdr_netobj::len has type
unsigned int, so the expression o1->len - o2->len _also_ has type
unsigned int; it has completely well-defined semantics, and the result
is some non-negative integer, which is always representable in a long
long. But this means that if the conditional triggers, we are
guaranteed to return a positive value from compare_blob.
In this case it could be fixed by
- res = o1->len - o2->len;
+ res = (long long)o1->len - (long long)o2->len;
but I'd rather eliminate the usually broken 'return a - b;' idiom.
Reviewed-by: Jeff Layton <jlayton@primarydata.com> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
An attempt to fix fcopy on i586 (bc5a5b0 Drivers: hv: util: Properly pack the data
for file copy functionality) led to a regression on x86_64 (and actually didn't fix
i586 breakage). Fcopy messages from Hyper-V host come in the following format:
On x86_64 struct hv_do_fcopy matched this format without ' __attribute__((packed))'
and on i586 adding ' __attribute__((packed))' to it doesn't change anything. Keep
the structure packed and add padding to match re reality. Tested both i586 and x86_64
on Hyper-V Server 2012 R2.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This happens due to the following race: between 'if (channel->device_obj)' check
in vmbus_process_rescind_offer() and pr_debug() in vmbus_device_unregister() the
device can disappear. Fix the issue by taking an additional reference to the
device before proceeding to vmbus_device_unregister().
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 19e2ad6a09f0c06dbca19c98e5f4584269d913dd ("n_tty: Remove overflow
tests from receive_buf() path") moved the increment of read_head into
the arguments list of read_buf_addr(). Function calls represent a
sequence point in C. Therefore read_head is incremented before the
character c is placed in the buffer. Since the circular read buffer is
a lock-less design since commit 6d76bd2618535c581f1673047b8341fd291abc67
("n_tty: Make N_TTY ldisc receive path lockless"), this creates a race
condition that leads to communication errors.
This patch modifies the code to increment read_head _after_ the data
is placed in the buffer and thus fixes the race for non-SMP machines.
To fix the problem for SMP machines, memory barriers must be added in
a separate patch.
Signed-off-by: Christian Riesch <christian.riesch@omicron.at> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds waiting until transmit buffer and shifter will be empty
before clock disabling.
Without this fix it's possible to have clock disabled while data was
not transmited yet, which causes unproper state of TX line and problems
in following data transfers.
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When recording the state of a task for the sched_switch tracepoint a check of
task_preempt_count() is performed to see if PREEMPT_ACTIVE is set. This is
because, technically, a task being preempted is really in the TASK_RUNNING
state, and that is what should be recorded when tracing a sched_switch,
even if the task put itself into another state (it hasn't scheduled out
in that state yet).
But with the change to use per_cpu preempt counts, the
task_thread_info(p)->preempt_count is no longer used, and instead
task_preempt_count(p) is used.
The problem is that this does not use the current preempt count but a stale
one from a previous sched_switch. The task_preempt_count(p) uses
saved_preempt_count and not preempt_count(). But for tracing sched_switch,
if p is current, we really want preempt_count().
I hit this bug when I was tracing sleep and the call from do_nanosleep()
scheduled out in the "RUNNING" state.
After a bit of hair pulling, I found that the state was really
TASK_INTERRUPTIBLE, but the saved_preempt_count had an old PREEMPT_ACTIVE
set and caused the sched_switch tracepoint to show it as RUNNING.
Link: http://lkml.kernel.org/r/20141210174428.3cb7542a@gandalf.local.home Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Fixes: 01028747559a "sched: Create more preempt_count accessors" Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After invoking ->dirty_inode(), __mark_inode_dirty() does smp_mb() and
tests inode->i_state locklessly to see whether it already has all the
necessary I_DIRTY bits set. The comment above the barrier doesn't
contain any useful information - memory barriers can't ensure "changes
are seen by all cpus" by itself.
And it sure enough was broken. Please consider the following
scenario.
CPU 0 CPU 1
-------------------------------------------------------------------------------
enters __writeback_single_inode()
grabs inode->i_lock
tests PAGECACHE_TAG_DIRTY which is clear
enters __set_page_dirty()
grabs mapping->tree_lock
sets PAGECACHE_TAG_DIRTY
releases mapping->tree_lock
leaves __set_page_dirty()
enters __mark_inode_dirty()
smp_mb()
sees I_DIRTY_PAGES set
leaves __mark_inode_dirty()
clears I_DIRTY_PAGES
releases inode->i_lock
Now @inode has dirty pages w/ I_DIRTY_PAGES clear. This doesn't seem
to lead to an immediately critical problem because requeue_inode()
later checks PAGECACHE_TAG_DIRTY instead of I_DIRTY_PAGES when
deciding whether the inode needs to be requeued for IO and there are
enough unintentional memory barriers inbetween, so while the inode
ends up with inconsistent I_DIRTY_PAGES flag, it doesn't fall off the
IO list.
The lack of explicit barrier may also theoretically affect the other
I_DIRTY bits which deal with metadata dirtiness. There is no
guarantee that a strong enough barrier exists between
I_DIRTY_[DATA]SYNC clearing and write_inode() writing out the dirtied
inode. Filesystem inode writeout path likely has enough stuff which
can behave as full barrier but it's theoretically possible that the
writeout may not see all the updates from ->dirty_inode().
Fix it by adding an explicit smp_mb() after I_DIRTY clearing. Note
that I_DIRTY_PAGES needs a special treatment as it always needs to be
cleared to be interlocked with the lockless test on
__mark_inode_dirty() side. It's cleared unconditionally and
reinstated after smp_mb() if the mapping still has dirty pages.
Also add comments explaining how and why the barriers are paired.
Lightly tested.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We can get here from blkdev_ioctl() -> blkpg_ioctl() -> add_partition()
with a user passed in partno value. If we pass in 0x7fffffff, the
new target in disk_expand_part_tbl() overflows the 'int' and we
access beyond the end of ptbl->part[] and even write to it when we
do the rcu_assign_pointer() to assign the new partition.
Currently we enable Exynos devices in the multi v7 defconfig, however, when
testing on my ODROID-U3, I noticed that USB was not working. Enabling this
option causes USB to work, which enables networking support as well since the
ODROID-U3 has networking on the USB bus.
[arnd] Support for odroid-u3 was added in 3.10, so it would be nice to
backport this fix at least that far.
Commit 7628083227b6bc4a7e33d7c381d7a4e558424b6b (usb: gadget: at91_udc:
prepare clk before calling enable) added clock preparation in interrupt
context. This is not allowed as it might sleep. Also setting the clock
rate is unsafe to call from there for the same reason. Move clock
preparation and setting clock rate into process context (at91udc_probe).
Signed-off-by: Ronald Wahl <ronald.wahl@raritan.com> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Felipe Balbi <balbi@ti.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes an issue that the NULL pointer dereference happens
when we uses g_audio driver. Since the g_audio driver will call
usb_ep_disable() in afunc_set_alt() before it calls usb_ep_enable(),
the uep->pipe of renesas usbhs driver will be NULL. So, this patch
adds a condition to avoid the oops.
It is critical that fetch_block() and handle_stripe_dirtying()
are consistent in their analysis of what needs to be loaded.
Otherwise raid5 can wait forever for a block that won't be loaded.
Currently when writing to a RAID5 that is resyncing, to a location
beyond the resync offset, handle_stripe_dirtying chooses a
reconstruct-write cycle, but fetch_block() assumes a
read-modify-write, and a lockup can happen.
So treat that case just like RAID6, just as we do in
handle_stripe_dirtying. RAID6 always does reconstruct-write.
This bug was introduced when the behaviour of handle_stripe_dirtying
was changed in 3.7, so the patch is suitable for any kernel since,
though it will need careful merging for some versions.
Fixes: a7854487cd7128a30a7f4f5259de9f67d5efb95f Reported-by: Henry Cai <henryplusplus@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
stac_store_hints() does utterly wrong for masking the values for
gpio_dir and gpio_data, likely due to copy&paste errors. Fortunately,
this feature is used very rarely, so the impact must be really small.
Commit 897c329bc ("ALSA: usb: caiaq: check for cdev->n_streams > 1")
introduced a safety check to protect against bogus data provided by
devices. However, the n_streams variable is already divided by
CHANNELS_PER_STREAM, so the correct check is 'n_streams > 0'.
In olden times the snd_hda_param_read() function always set "*start_id"
but in 2007 we introduced a new return and it causes uninitialized data
bugs in a couple of the callers: print_codec_info() and
hdmi_parse_codec().
The Arcam rPAC seems to have the same problem - whenever anything
(alsamixer, udevd, 3.9+ kernel from 60af3d037eb8c, ..) attempts to
access mixer / control interface of the card, the firmware "locks up"
the entire device, resulting in
SNDRV_PCM_IOCTL_HW_PARAMS failed (-5): Input/output error
from alsa-lib.
Other operating systems can somehow read the mixer (there seems to be
playback volume/mute), but any manipulation is ignored by the device
(which has hardware volume controls).
In (6468276 i2c: designware: make SCL and SDA falling time
configurable) new device tree properties were added for setting the
falling time of SDA and SCL. The device tree bindings doc had a typo
in it: it forgot the "-ns" suffix for both properies in the prose of
the bindings.
I assume this is a typo because:
* The source code includes the "-ns"
* The example in the bindings includes the "-ns".
Fix the typo.
Signed-off-by: Doug Anderson <dianders@chromium.org> Fixes: 6468276b2206 ("i2c: designware: make SCL and SDA falling time configurable") Acked-by: Romain Baeriswyl <romain.baeriswyl@alitech.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
`genwqe_user_vmap()` calls `get_user_pages_fast()` and if the return
value is less than the number of pages requested, it frees the pages and
returns an error (`-EFAULT`). However, it fails to consider a negative
error return value from `get_user_pages_fast()`. In that case, the test
`if (rc < m->nr_pages)` will be false (due to promotion of `rc` to a
large `unsigned int`) and the code will continue on to call
`genwqe_map_pages()` with an invalid list of page pointers. Fix it by
bailing out if `get_user_pages_fast()` returns a negative error value.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bus_find_device_by_name() acquires a device reference which is never
released. This results in an object leak, which on older kernels
results in failure to release all resources of PCI devices. libvirt
uses drivers_probe to re-attach devices to the host after assignment
and is therefore a common trigger for this leak.
In Linux 3.18 and below, GCC hoists the lsl instructions in the
pvclock code all the way to the beginning of __vdso_clock_gettime,
slowing the non-paravirt case significantly. For unknown reasons,
presumably related to the removal of a branch, the performance issue
is gone as of
e76b027e6408 x86,vdso: Use LSL unconditionally for vgetcpu
but I don't trust GCC enough to expect the problem to stay fixed.
There should be no correctness issue, because the __getcpu calls in
__vdso_vlock_gettime were never necessary in the first place.
Note to stable maintainers: In 3.18 and below, depending on
configuration, gcc 4.9.2 generates code like this:
This patch won't apply as is to any released kernel, but I'll send a
trivial backported version if needed.
[
Backported by Andy Lutomirski. Should apply to all affected
versions. This fixes a functionality bug as well as a performance
bug: buggy kernels can infinite loop in __vdso_clock_gettime on
affected compilers. See, for exammple:
The theory behind vdso randomization is that it's mapped at a random
offset above the top of the stack. To avoid wasting a page of
memory for an extra page table, the vdso isn't supposed to extend
past the lowest PMD into which it can fit. Other than that, the
address should be a uniformly distributed address that meets all of
the alignment requirements.
The current algorithm is buggy: the vdso has about a 50% probability
of being at the very end of a PMD. The current algorithm also has a
decent chance of failing outright due to incorrect handling of the
case where the top of the stack is near the top of its PMD.
This fixes the implementation. The paxtest estimate of vdso
"randomisation" improves from 11 bits to 18 bits. (Disclaimer: I
don't know what the paxtest code is actually calculating.)
It's worth noting that this algorithm is inherently biased: the vdso
is more likely to end up near the end of its PMD than near the
beginning. Ideally we would either nix the PMD sharing requirement
or jointly randomize the vdso and the stack to reduce the bias.
In the mean time, this is a considerable improvement with basically
no risk of compatibility issues, since the allowed outputs of the
algorithm are unchanged.
As an easy test, doing this:
for i in `seq 10000`
do grep -P vdso /proc/self/maps |cut -d- -f1
done |sort |uniq -d
used to produce lots of output (1445 lines on my most recent run).
A tiny subset looks like this:
ipte_unlock_siif uses cmpxchg to replace the in-memory data of the ipte
lock together with ACCESS_ONCE for the intial read.
union ipte_control {
unsigned long val;
struct {
unsigned long k : 1;
unsigned long kh : 31;
unsigned long kg : 32;
};
};
[...]
static void ipte_unlock_siif(struct kvm_vcpu *vcpu)
{
union ipte_control old, new, *ic;
ic = &vcpu->kvm->arch.sca->ipte_control;
do {
new = old = ACCESS_ONCE(*ic);
new.kh--;
if (!new.kh)
new.k = 0;
} while (cmpxchg(&ic->val, old.val, new.val) != old.val);
if (!new.kh)
wake_up(&vcpu->kvm->arch.ipte_wq);
}
The new value, is loaded twice from memory with gcc 4.7.2 of
fedora 18, despite the ACCESS_ONCE:
--->
l %r4,0(%r3) <--- load first 32 bit of lock (k and kh) in r4
alfi %r4,2147483647 <--- add -1 to r4
llgtr %r4,%r4 <--- zero out the sign bit of r4
lg %r1,0(%r3) <--- load all 64 bit of lock into new
lgr %r2,%r1 <--- load the same into old
risbg %r1,%r4,1,31,32 <--- shift and insert r4 into the bits 1-31 of
new
llihf %r4,2147483647
ngrk %r4,%r1,%r4
jne aa0 <ipte_unlock+0xf8>
nihh %r1,32767
lgr %r4,%r2
csg %r4,%r1,0(%r3)
cgr %r2,%r4
jne a70 <ipte_unlock+0xc8>
If the memory value changes between the first load (l) and the second
load (lg) we are broken. If that happens VCPU threads will hang
(unkillable) in handle_ipte_interlock.
Andreas Krebbel analyzed this and tracked it down to a compiler bug in
that version:
"while it is not that obvious the C99 standard basically forbids
duplicating the memory access also in that case. For an argumentation of
a similiar case please see:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=22278#c43
For the implementation-defined cases regarding volatile there are some
GCC-specific clarifications which can be found here:
https://gcc.gnu.org/onlinedocs/gcc/Volatiles.html#Volatiles
I've tracked down the problem with a reduced testcase. The problem was
that during a tree level optimization (SRA - scalar replacement of
aggregates) the volatile marker is lost. And an RTL level optimizer (CSE
- common subexpression elimination) then propagated the memory read into
its second use introducing another access to the memory location. So
indeed Christian's suspicion that the union access has something to do
with it is correct (since it triggered the SRA optimization).
This issue has been reported and fixed in the GCC 4.8 development cycle:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145"
This patch replaces the ACCESS_ONCE scheme with a barrier() based scheme
that should work for all supported compilers.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
some control register changes will flush some aspects of the CPU, e.g.
POP explicitely mentions that for CR9-CR11 "TLBs may be cleared".
Instead of trying to be clever and only flush on specific CRs, let
play safe and flush on all lctl(g) as future machines might define
new bits in CRs. Load control intercept should not happen that often.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Userspace is expecting non-compacted format for KVM_GET_XSAVE, but
struct xsave_struct might be using the compacted format. Convert
in order to preserve userspace ABI.
Likewise, userspace is passing non-compacted format for KVM_SET_XSAVE
but the kernel will pass it to XRSTORS, and we need to convert back.
Fixes: f31a9f7c71691569359fa7fb8b0acaa44bce0324 Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@linux.intel.com> Tested-by: Nadav Amit <namit@cs.technion.ac.il> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
get_xsave_addr is the API to access XSAVE states, and KVM would
like to use it. Export it.
Cc: x86@kernel.org Cc: H. Peter Anvin <hpa@linux.intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
New Genius MousePen i608X devices have a new id 0x501a instead of the
old 0x5011 so add a new #define with "_2" appended and change required
places.
The remaining two checkpatch warnings about line length
being over 80 characters are present in the original files too and this
patch was made in the same style (no line break).
Just adding a new id and changing the required places should make the
new device work without any issues according to the bug report in the
following url.
This patch was made according to and fixes:
https://bugzilla.kernel.org/show_bug.cgi?id=67111
Apple bluetooth wireless keyboard (sold in UK) has always reported zero
for battery strength no matter what condition the batteries are actually
in. With this patch applied (applying same quirk as other Apple
keyboards), the battery strength is now correctly reported.
When a hid driver that uses i2c-hid as transport is unloaded, the hid core
will call i2c_hid_stop() which releases all the buffers associated with the
device. This includes also the command buffer.
Now, when the i2c-hid driver itself is unloaded it tries to power down the
device by sending it PWR_SLEEP command. Since the command buffer is already
released we get following crash:
This is a static checker fix. We write some binary settings to the
sysfs file. One of the settings is the "->startup_profile". There
isn't any checking to make sure it fits into the
pyra->profile_settings[] array in the profile_activated() function.
I added a check to pyra_sysfs_write_settings() in both places because
I wasn't positive that the other callers were correct.
Before ->start() is called, bufsize size is set to HID_MIN_BUFFER_SIZE,
64 bytes. While processing the IRQ, we were asking to receive up to
wMaxInputLength bytes, which can be bigger than 64 bytes.
Later, when ->start is run, a proper bufsize will be calculated.
Given wMaxInputLength is said to be unreliable in other part of the
code, set to receive only what we can even if it results in truncated
reports.
Current driver uses a common buffer for reading reports either
synchronously in i2c_hid_get_raw_report() and asynchronously in
the interrupt handler.
There is race condition if an interrupt arrives immediately after
the report is received in i2c_hid_get_raw_report(); the common
buffer is modified by the interrupt handler with the new report
and then i2c_hid_get_raw_report() proceed using wrong data.
Fix it by using a separate buffers for synchronous reports.
Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
[Antonio Borneo: cleanup, rebase to v3.17, submit mainline] Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com> Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
So here, wacom_open is called, and then wacom_resume is called by the
PM system. However, wacom_open already took the lock when wacom_resume
tries to get it. Freeze.
A little bit of history shows that this already happened in the past
- commit f6cd378372bf ("Input: wacom - fix runtime PM related deadlock"),
and the solution was to call first the PM function before taking the lock.
The lock was introduced in commit commit e722409445fb ("Input: wacom -
implement suspend and autosuspend") when the autosuspend feature has
been added. Given that usbhid already takes care of this very same
locking between suspend/resume, I think we can simply kill the lock
in open/close.
The lock is now used also with LEDs, so we can not remove it completely.
Reported-by: Hans Spath <inbox-546@hans-spath.de> Tested-by: Hans Spath <inbox-546@hans-spath.de> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
projects / linux-stable / log