If a rescuer and stop_machine() bringing down a CPU race with each
other, they may deadlock on non-preemptive kernel. The CPU won't
accept a new task, so the rescuer can't migrate to the target CPU,
while stop_machine() can't proceed because the rescuer is holding one
of the CPU retrying migration. GCWQ_DISASSOCIATED is never cleared
and worker_maybe_bind_and_lock() retries indefinitely.
This problem can be reproduced semi reliably while the system is
entering suspend.
http://thread.gmane.org/gmane.linux.kernel/1122051
A lot of kudos to Thilo-Alexander for reporting this tricky issue and
painstaking testing.
stable: This affects all kernels with cmwq, so all kernels since and
including v2.6.36 need this fix.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Thilo-Alexander Ginkel <thilo@ginkel.com>
Tested-by: Thilo-Alexander Ginkel <thilo@ginkel.com>
Cc: stable@kernel.org
Fix CI data transfer regression introduced by previous cleanup.
Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Some v4l drivers currently don't initialize their struct v4l2_subdev
with zeros, and this is a problem since some of the v4l2 code expects
this. One example is the addition of internal_ops in commit 45f6f84,
after that we are at risk of random oopses with these drivers when code
in v4l2_device_register_subdev tries to dereference sd->internal_ops->*,
as can be shown by the report at http://bugs.launchpad.net/bugs/745213
and analysis of its crash at https://lkml.org/lkml/2011/4/1/168
Use kzalloc within problematic drivers to ensure we have a zeroed struct
v4l2_subdev.
BugLink: http://bugs.launchpad.net/bugs/745213
Cc: <stable@kernel.org>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
* 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6:
OMAP3+: voltage: remove initial voltage
OMAP4: Intialize IVA Device in addition to DSP device.
omap: rx51: mark reserved memory earlier
OMAP3: l3: fix for "irq 10: nobody cared" message
arm: omap2: enable smc instruction for sleep34xx
OMAP2/3: hwmod: fix gpio-reset timeouts seen during bootup.
OMAP3: PM: Do not rely on ROM code to restore CM_AUTOIDLE_PLL.AUTO_PERIPH_DPLL
OMAP2+: PM: Fix the saving of CM_AUTOIDLE_PLL register on scratchpad area
OMAP4: clock data: Change DSS clock aliases
OMAP2+: hwmod data: Fix wrong dma_system end address
When CONFIG_OABI_COMPAT is set, the wrapper for semtimedop does not
bound the nsops argument. A sufficiently large value will cause an
integer overflow in allocation size, followed by copying too much data
into the allocated buffer. Fix this by restricting nsops to SEMOPM.
Untested.
Cc: stable@kernel.org
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The following is a patch to avoid a kernel oops when running rmmod
saa7134 on kernel 2.6.27.1. The change is as suggested by mchehab on
irc.freenode.org
Signed-off-by: Hussam Al-Tayeb <ht990332@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
We must remove all files we created, even in error cases.
Fixes second part of kernel bug #34072:
https://bugzilla.kernel.org/show_bug.cgi?id=34072
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
Recent Xeon processor thermal sensors are supported by the coretemp
driver and not the adm1021 driver. Only one old generation of Xeon
processors (the first Netburst ones) are supported by the adm1021
driver.
Reported-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
The lm90 driver's attribute update interval is configurable.
Reflect this information in the driver documentation.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
This patch adds support for ADT7461A and NCT1008 to the lm90 driver.
Both chips have identical functionality and report the same manufacturing ID
and device ID values.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The imon_ir_change_protocol function gets called two different ways, one
way is from rc_register_device, for initial protocol selection/setup,
and the other is via a userspace-initiated protocol change request,
either by direct sysfs prodding or by something like ir-keytable.
In the rc_register_device case, the imon context lock is already held,
but when initiated from userspace, it is not, so we must acquire it,
prior to calling send_packet, which requires that the lock is held.
Without this change, there's an easily reproduceable deadlock when
another function calls send_packet (such as either of the display write
fops) after a userspace-initiated change_protocol.
With a lock-debugging-enabled kernel, I was getting this:
[ 15.014153] =====================================
[ 15.015048] [ BUG: bad unlock balance detected! ]
[ 15.015048] -------------------------------------
[ 15.015048] ir-keytable/773 is trying to release lock (&ictx->lock) at:
[ 15.015048] [<ffffffff814c6297>] mutex_unlock+0xe/0x10
[ 15.015048] but there are no more locks to release!
[ 15.015048]
[ 15.015048] other info that might help us debug this:
[ 15.015048] 2 locks held by ir-keytable/773:
[ 15.015048] #0: (&buffer->mutex){+.+.+.}, at: [<ffffffff8119d400>] sysfs_write_file+0x3c/0x144
[ 15.015048] #1: (s_active#87){.+.+.+}, at: [<ffffffff8119d4ab>] sysfs_write_file+0xe7/0x144
[ 15.015048]
[ 15.015048] stack backtrace:
[ 15.015048] Pid: 773, comm: ir-keytable Not tainted 2.6.38.4-20.fc15.x86_64.debug #1
[ 15.015048] Call Trace:
[ 15.015048] [<ffffffff81089715>] ? print_unlock_inbalance_bug+0xca/0xd5
[ 15.015048] [<ffffffff8108b35c>] ? lock_release_non_nested+0xc1/0x263
[ 15.015048] [<ffffffff814c6297>] ? mutex_unlock+0xe/0x10
[ 15.015048] [<ffffffff814c6297>] ? mutex_unlock+0xe/0x10
[ 15.015048] [<ffffffff8108b67b>] ? lock_release+0x17d/0x1a4
[ 15.015048] [<ffffffff814c6229>] ? __mutex_unlock_slowpath+0xc5/0x125
[ 15.015048] [<ffffffff814c6297>] ? mutex_unlock+0xe/0x10
[ 15.015048] [<ffffffffa02964b6>] ? send_packet+0x1c9/0x264 [imon]
[ 15.015048] [<ffffffff8108b376>] ? lock_release_non_nested+0xdb/0x263
[ 15.015048] [<ffffffffa0296731>] ? imon_ir_change_protocol+0x126/0x15e [imon]
[ 15.015048] [<ffffffffa024a334>] ? store_protocols+0x1c3/0x286 [rc_core]
[ 15.015048] [<ffffffff81326e4e>] ? dev_attr_store+0x20/0x22
[ 15.015048] [<ffffffff8119d4cc>] ? sysfs_write_file+0x108/0x144
...
The original report that led to the investigation was the following:
[ 1679.457305] INFO: task LCDd:8460 blocked for more than 120 seconds.
[ 1679.457307] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1679.457309] LCDd D ffff88010fcd89c8 0 8460 1 0x00000000
[ 1679.457312] ffff8800d5a03b48 0000000000000082 0000000000000000 ffff8800d5a03fd8
[ 1679.457314] 00000000012dcd30 fffffffffffffffd ffff8800d5a03fd8 ffff88010fcd86f0
[ 1679.457316] ffff8800d5a03fd8 ffff8800d5a03fd8 ffff88010fcd89d0 ffff8800d5a03fd8
[ 1679.457319] Call Trace:
[ 1679.457324] [<ffffffff810ff1a5>] ? zone_statistics+0x75/0x90
[ 1679.457327] [<ffffffff810ea907>] ? get_page_from_freelist+0x3c7/0x820
[ 1679.457330] [<ffffffff813b0a49>] __mutex_lock_slowpath+0x139/0x320
[ 1679.457335] [<ffffffff813b0c41>] mutex_lock+0x11/0x30
[ 1679.457338] [<ffffffffa0d54216>] display_open+0x66/0x130 [imon]
[ 1679.457345] [<ffffffffa01d06c0>] usb_open+0x180/0x310 [usbcore]
[ 1679.457349] [<ffffffff81143b3b>] chrdev_open+0x1bb/0x2d0
[ 1679.457350] [<ffffffff8113d93d>] __dentry_open+0x10d/0x370
[ 1679.457352] [<ffffffff81143980>] ? chrdev_open+0x0/0x2d0
...
Bump the driver version here so its easier to tell if people have this
locking fix or not, and also make locking during probe easier to follow.
CC: stable@kernel.org
Reported-by: Benjamin Hodgetts <ben@xnode.org>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
The PCI SSID is 1025:031c and the codec SSID is 1025:031d,
so the driver mistakes this for a SKU value, but looking at
the numbers, this is obviously wrong.
Cc: stable@kernel.org (2.6.38+)
BugLink: http://bugs.launchpad.net/bugs/761861
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Sedat and Bruno reported RCU stalls which turned out to be caused by
the following;
sched_init() calls init_rt_bandwidth() which calls hrtimer_init()
_BEFORE_ hrtimers_init() is called. While not entirely correct this
worked because hrtimer_init() only accessed statically initialized
data (hrtimer_bases.clock_base[CLOCK_MONOTONIC])
Commit e06383db9 (hrtimers: extend hrtimer base code to handle more
then 2 clockids) added an indirection to the hrtimer_bases.clock_base
lookup to avoid gap handling in the hot path. The table which is used
for the translataion from CLOCK_ID to HRTIMER_BASE index is
initialized at runtime in hrtimers_init(). So the early call of the
scheduler code translates CLOCK_MONOTONIC to HRTIMER_BASE_REALTIME.
Thus the rt_bandwith timer ends up on CLOCK_REALTIME. If the timer is
armed and the wall clock time is set (e.g. ntpdate in the early boot
process - which also gives the problem deterministic behaviour
i.e. magic recovery after N hours), then the timer ends up with an
expiry time far into the future. That breaks the RT throttler
mechanism as rt runtime is accumulated and never cleared, so the rt
throttler detects a false cpu hog condition and blocks all RT tasks
until the timer finally expires. That in turn stalls the RCU thread of
TINYRCU which leads to an huge amount of RCU callbacks piling up.
Make the translation table statically initialized, so we are back to
the status of <= 2.6.39.
Reported-and-tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reported-by: Bruno Prémont <bonbons@linux-vserver.org>
Cc: John stultz <johnstul@us.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/%3Calpine.LFD.2.02.1104282353140.3005%40ionos%3E
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
pfault, dasd diag and virtio all use the same external interrupt number.
The respective interrupt handlers decide by the subcode if they are
meant to handle the interrupt.
Counting is currently done before looking at the subcode which means
each handler counts an interrupt even if it is not handling it.
Fix this by moving the kstat code after the code which looks at the
subcode.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
PC Beep was not being reported as enabled on my EeePC 901:
SKU: enable_pcbeep=0x0
Signed-off-by: Daniel Cordero <danielcordero@lavabit.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
There are a couple of places in this code where these values can wrap or
go negative, and that could potentially end up overflowing the buffer.
Ensure that that doesn't happen. Do all of the length calculation and
checks first, and only perform the memcpy after they pass.
Also, increase some stack variables to 32 bits to ensure that they don't
wrap without being detected.
Finally, change the error codes to be a bit more descriptive of any
problems detected. -EINVAL isn't very accurate.
Cc: stable@kernel.org
Reported-and-Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
It's possible that when we go to decode the string area in the
SESSION_SETUP response, that bytes_remaining will be 0. Decrementing it at
that point will mean that it can go "negative" and wrap. Check for a
bytes_remaining value of 0, and don't try to decode the string area if
that's the case.
Cc: stable@kernel.org
Reported-and-Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
The buffer length checks in this function depend on this value being a
signed data type, but 690c522fa converted it to an unsigned type.
Also, eliminate a problem with the null termination check in the same
function. cifs_strndup_from_ucs handles that situation correctly
already, and the existing check could potentially lead to a buffer
overrun since it increments bleft without checking to see whether it
falls off the end of the buffer.
Cc: stable@kernel.org
Reported-and-Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
- Remove coding standard violations reported by checkpatch.pl
- Delete comment about handling of conditional branches which is no
longer true.
- Delete comment at end of file which lists all ARM instructions. This
duplicates data available in the ARM ARM and seems like an
unnecessary maintenance burden to keep this up to date and accurate.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Being able to probe NOP instructions is useful for hard-coding probeable
locations and is used by the kprobes test code.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
These bit field manipulation instructions occur several thousand
times in an ARMv7 kernel.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The MOVW and MOVT instructions account for approximately 7% of all
instructions in a ARMv7 kernel as GCC uses them instead of a literal
pool.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The instruction decoding in space_cccc_000x needs to reject probing of
instructions with undefined patterns as they may in future become
defined and then emulated faultily - as has already happened with the
SMC instruction.
This fix is achieved by testing for the instruction patterns we want to
probe and making the the default fall-through paths reject probes. This
also allows us to remove some explicit tests for instructions that we
wish to reject, as that is now the default action.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The tests to explicitly reject probing CPS, RFE and SRS instructions
are redundant as the default case is now to reject undecoded patterns.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The PLD instructions wasn't being decoded correctly and the emulation
code wasn't adjusting PC correctly.
As the PLD instruction is only a performance hint we emulate it as a
simple nop, and we can broaden the instruction decoding to take into
account newer PLI and PLDW instructions.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The emulation of SETEND was broken as it changed the endianess for
the running kprobes handling code. Rather than adding a new simulation
routine to fix this we'll just reject probing of SETEND as these should
be very rare in the kernel.
Note, the function emulate_none is now unused but it is left in the
source code as future patches will use it.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Following the change to remove support for coprocessor instructions
we are left with three stub functions which can be consolidated.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The kernel doesn't currently support VFP or Neon code, and probing of
code with CP15 operations is fraught with bad consequences. Therefore we
don't need the ability to probe coprocessor instructions and the code to
support this can be removed.
The removed code also had at least two bugs:
- MRC into R15 should set CPSR not trash PC
- LDC and STC which use PC as base register needed the address offset by 8
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The USAD8 instruction wasn't being explicitly decoded leading
to the incorrect emulation routine being called. It can be correctly
decoded in the same way as the signed multiply instructions so we move
the decoding there.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The signed multiply instructions were being decoded incorrectly.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
These sign extension instructions are encoded as extend-and-add
instructions where the register to add is specified as r15. The decoding
routines weren't checking for this and were using the incorrect
emulation code, giving incorrect results.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The instructions space for media instructions contains some undefined
patterns. We need to reject probing of these because they may in future
become defined and the kprobes code may then emulate them faultily.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The v6T2 RBIT instruction was accidentally being emulated correctly,
this patch adds correct decoding for the instruction.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
These instructions are specified as UNPREDICTABLE.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The decoding of these instructions got the register indexed and
immediate indexed forms the wrong way around, causing incorrect
emulation.
Instructions like "LDRD Rx, [Rx]" were corrupting Rx because the base
register writeback was being performed unconditionally, overwriting the
value just loaded from memory. The fix is to only writeback the base
register when that form of the instruction is used. Note, now that we
reject probing writeback with PC the emulation code doesn't need the
check rn!=15.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Using PC as an base register with writeback is UNPREDICTABLE, as is non
word-sized loads or stores of PC. (We only really care about preventing
loads to PC but it keeps the code simpler if we also exclude stores.)
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The decoding of these instructions got the register indexed and
immediate indexed forms the wrong way around, causing incorrect
emulation.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The emulation code for STREX and LDREX instructions is faulty, however,
rather than attempting to fix this we reject probes of these
instructions. We do this because they can never succeed in gaining
exclusive access as the exception framework clears the exclusivity
monitor when a probes breakpoint is hit. (This is a general problem
when probing all instructions executing between a LDREX and its
corresponding STREX and can lead to infinite retry loops.)
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The instructions space for 'Multiply and multiply-accumulate'
instructions contains some undefined patterns. We need to reject
probing of these because they may in future become defined and the
kprobes code may then emulate them faultily.
This has already happened with the new MLS instruction which this patch
also adds correct decoding for as well as tightening up other decoding
tests. (Before this patch the wrong emulation routine was being called
for MLS though it still produced correct results.)
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The MRS instruction should set mode and interrupt bits in the read value
so it is simpler to use a new simulation routine (simulate_mrs) rather
than some modified emulation.
prep_emulate_rd12 is now unused and removed.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
We need to reject probing of instructions which read SPSR because
we can't handle this as the value in SPSR is lost when the exception
handler for the probe breakpoint first runs.
This patch also fixes the bitmask for MRS instructions decoding to
include checking bits 5-7.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Emulation of instructions like "ADD rd, rn, #<const>" would result in a
corrupted value for rd.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
