When we enable DEBUG_LOCK_ALLOC but do not enable PROVE_LOCKING and or
LOCK_STAT, lock_alloc() and lock_release() turn into nops, even though
we should be doing hlock checking (check=1).
This causes a false warning and a lockdep self-disable.
Rectify this.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
certain configs produce:
[ 70.076229] BUG: MAX_LOCKDEP_KEYS too low!
[ 70.080230] turning off the locking correctness validator.
tune them up.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Venki Pallipadi <venkatesh.pallipadi@intel.com> wrote:
> Found a OOPS on a big SMP box during an overnight reboot test with
> upstream git.
>
> Suresh and I looked at the oops and looks like the root cause is in
> generic_smp_call_function_interrupt() and smp_call_function_mask() with
> wait parameter.
>
> The actual oops looked like
>
> [ 11.277260] BUG: unable to handle kernel paging request at ffff8802ffffffff
> [ 11.277815] IP: [<ffff8802ffffffff>] 0xffff8802ffffffff
> [ 11.278155] PGD 202063 PUD 0
> [ 11.278576] Oops: 0010 [1] SMP
> [ 11.279006] CPU 5
> [ 11.279336] Modules linked in:
> [ 11.279752] Pid: 0, comm: swapper Not tainted 2.6.27-rc2-00020-g685d87f #290
> [ 11.280039] RIP: 0010:[<ffff8802ffffffff>] [<ffff8802ffffffff>] 0xffff8802ffffffff
> [ 11.280692] RSP: 0018:ffff88027f1f7f70 EFLAGS: 00010086
> [ 11.280976] RAX: 00000000ffffffff RBX: 0000000000000000 RCX: 0000000000000000
> [ 11.281264] RDX: 0000000000004f4e RSI: 0000000000000001 RDI: 0000000000000000
> [ 11.281624] RBP: ffff88027f1f7f98 R08: 0000000000000001 R09: ffffffff802509af
> [ 11.281925] R10: ffff8800280c2780 R11: 0000000000000000 R12: ffff88027f097d48
> [ 11.282214] R13: ffff88027f097d70 R14: 0000000000000005 R15: ffff88027e571000
> [ 11.282502] FS: 0000000000000000(0000) GS:ffff88027f1c3340(0000) knlGS:0000000000000000
> [ 11.283096] CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b
> [ 11.283382] CR2: ffff8802ffffffff CR3: 0000000000201000 CR4: 00000000000006e0
> [ 11.283760] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [ 11.284048] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> [ 11.284337] Process swapper (pid: 0, threadinfo ffff88027f1f2000, task ffff88027f1f0640)
> [ 11.284936] Stack: ffffffff80250963 0000000000000212 0000000000ee8c78 0000000000ee8a66
> [ 11.285802] ffff88027e571550 ffff88027f1f7fa8 ffffffff8021adb5 ffff88027f1f3e40
> [ 11.286599] ffffffff8020bdd6 ffff88027f1f3e40 <EOI> ffff88027f1f3ef8 0000000000000000
> [ 11.287120] Call Trace:
> [ 11.287768] <IRQ> [<ffffffff80250963>] ? generic_smp_call_function_interrupt+0x61/0x12c
> [ 11.288354] [<ffffffff8021adb5>] smp_call_function_interrupt+0x17/0x27
> [ 11.288744] [<ffffffff8020bdd6>] call_function_interrupt+0x66/0x70
> [ 11.289030] <EOI> [<ffffffff8024ab3b>] ? clockevents_notify+0x19/0x73
> [ 11.289380] [<ffffffff803b9b75>] ? acpi_idle_enter_simple+0x18b/0x1fa
> [ 11.289760] [<ffffffff803b9b6b>] ? acpi_idle_enter_simple+0x181/0x1fa
> [ 11.290051] [<ffffffff8053aeca>] ? cpuidle_idle_call+0x70/0xa2
> [ 11.290338] [<ffffffff80209f61>] ? cpu_idle+0x5f/0x7d
> [ 11.290723] [<ffffffff8060224a>] ? start_secondary+0x14d/0x152
> [ 11.291010]
> [ 11.291287]
> [ 11.291654] Code: Bad RIP value.
> [ 11.292041] RIP [<ffff8802ffffffff>] 0xffff8802ffffffff
> [ 11.292380] RSP <ffff88027f1f7f70>
> [ 11.292741] CR2: ffff8802ffffffff
> [ 11.310951] ---[ end trace 137c54d525305f1c ]---
>
> The problem is with the following sequence of events:
>
> - CPU A calls smp_call_function_mask() for CPU B with wait parameter
> - CPU A sets up the call_function_data on the stack and does an rcu add to
> call_function_queue
> - CPU A waits until the WAIT flag is cleared
> - CPU B gets the call function interrupt and starts going through the
> call_function_queue
> - CPU C also gets some other call function interrupt and starts going through
> the call_function_queue
> - CPU C, which is also going through the call_function_queue, starts referencing
> CPU A's stack, as that element is still in call_function_queue
> - CPU B finishes the function call that CPU A set up and as there are no other
> references to it, rcu deletes the call_function_data (which was from CPU A
> stack)
> - CPU B sees the wait flag and just clears the flag (no call_rcu to free)
> - CPU A which was waiting on the flag continues executing and the stack
> contents change
>
> - CPU C is still in rcu_read section accessing the CPU A's stack sees
> inconsistent call_funation_data and can try to execute
> function with some random pointer, causing stack corruption for A
> (by clearing the bits in mask field) and oops.
Nice debugging work.
I'd suggest something like the attached (boot tested) patch as the simple
fix for now.
I expect the benefits from the less synchronized, multiple-in-flight-data
global queue will still outweigh the costs of dynamic allocations. But
if worst comes to worst then we just go back to a globally synchronous
one-at-a-time implementation, but that would be pretty sad!
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There is a overflow by 1 case in the new shrunken hlock code.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
the names were too generic:
drivers/uio/uio.c:87: error: expected identifier or '(' before 'do'
drivers/uio/uio.c:87: error: expected identifier or '(' before 'while'
drivers/uio/uio.c:113: error: 'map_release' undeclared here (not in a function)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Solve this by marking the classes as unused and not printing information
about the unused classes.
Reported-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Rabin Vincent <rabin@rab.in>
Acked-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The nesting is correct due to holding mmap_sem, use the new annotation
to annotate this.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Expose the new lock protection lock.
This can be used to annotate places where we take multiple locks of the
same class and avoid deadlocks by always taking another (top-level) lock
first.
NOTE: we're still bound to the MAX_LOCK_DEPTH (48) limit.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
On Fri, 2008-08-01 at 16:26 -0700, Linus Torvalds wrote:
> On Fri, 1 Aug 2008, David Miller wrote:
> >
> > Taking more than a few locks of the same class at once is bad
> > news and it's better to find an alternative method.
>
> It's not always wrong.
>
> If you can guarantee that anybody that takes more than one lock of a
> particular class will always take a single top-level lock _first_, then
> that's all good. You can obviously screw up and take the same lock _twice_
> (which will deadlock), but at least you cannot get into ABBA situations.
>
> So maybe the right thing to do is to just teach lockdep about "lock
> protection locks". That would have solved the multi-queue issues for
> networking too - all the actual network drivers would still have taken
> just their single queue lock, but the one case that needs to take all of
> them would have taken a separate top-level lock first.
>
> Never mind that the multi-queue locks were always taken in the same order:
> it's never wrong to just have some top-level serialization, and anybody
> who needs to take <n> locks might as well do <n+1>, because they sure as
> hell aren't going to be on _any_ fastpaths.
>
> So the simplest solution really sounds like just teaching lockdep about
> that one special case. It's not "nesting" exactly, although it's obviously
> related to it.
Do as Linus suggested. The lock protection lock is called nest_lock.
Note that we still have the MAX_LOCK_DEPTH (48) limit to consider, so anything
that spills that it still up shit creek.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Most the free-standing lock_acquire() usages look remarkably similar, sweep
them into a new helper.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Instead of using a per-rq lock class, use the regular nesting operations.
However, take extra care with double_lock_balance() as it can release the
already held rq->lock (and therefore change its nesting class).
So what can happen is:
spin_lock(rq->lock); // this rq subclass 0
double_lock_balance(rq, other_rq);
// release rq
// acquire other_rq->lock subclass 0
// acquire rq->lock subclass 1
spin_unlock(other_rq->lock);
leaving you with rq->lock in subclass 1
So a subsequent double_lock_balance() call can try to nest a subclass 1
lock while already holding a subclass 1 lock.
Fix this by introducing double_unlock_balance() which releases the other
rq's lock, but also re-sets the subclass for this rq's lock to 0.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
this can be used to reset a held lock's subclass, for arbitrary-depth
iterated data structures such as trees or lists which have per-node
locks.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
[CPUFREQ][2/2] preregister support for powernow-k8
[CPUFREQ][1/2] whitespace fix for powernow-k8
[CPUFREQ] Update MAINTAINERS to reflect new mailing list.
[CPUFREQ] Fix warning in elanfreq
[CPUFREQ] Fix -Wshadow warning in conservative governor.
[CPUFREQ] Remove EXPERIMENTAL annotation from VIA C7 powersaver kconfig.
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
[CIFS] list entry can not return null
turn cifs_setattr into a multiplexor that calls the correct function
move file time and dos attribute setting logic into new function
spin off cifs_setattr with unix extensions to its own function
[CIFS] Code cleanup in old sessionsetup code
[CIFS] cifs_mkdir and cifs_create should respect the setgid bit on parent dir
Rename CIFSSMBSetFileTimes to CIFSSMBSetFileInfo and add PID arg
change CIFSSMBSetTimes to CIFSSMBSetPathInfo
[CIFS] fix trailing whitespace
bundle up Unix SET_PATH_INFO args into a struct and change name
Fix missing braces in cifs_revalidate()
remove locking around tcpSesAllocCount atomic variable
[CIFS] properly account for new user= field in SPNEGO upcall string allocation
[CIFS] remove level of indentation from decode_negTokenInit
[CIFS] cifs send2 not retrying enough in some cases on full socket
[CIFS] oid should also be checked against class in cifs asn
Fix fatal multi-line kernel-doc error in list.h:
function short description must be on one line.
Error(linux-2.6.27-rc2-git3//include/linux/list.h:318): duplicate section name 'Description'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch provides support for the _PSD ACPI object in the Powernow-k8
driver. Although it looks like an invasive patch, most of it is
simply the consequence of turning the static acpi_performance_data
structure into a pointer.
AMD has tested it on several machines over the past few days without issue.
[trivial checkpatch warnings fixed up by davej]
[X86_POWERNOW_K8_ACPI=n buildfix from Randy Dunlap]
Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
Tested-by: Frank Arnold <frank.arnold@amd.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Dave Jones <davej@redhat.com>
arch/x86/kernel/cpu/cpufreq/elanfreq.c:47:26: warning: symbol 'elan_multiplier' was not declared. Should it be static?
Yes, yes it should.
Signed-off-by: Dave Jones <davej@redhat.com>
drivers/cpufreq/cpufreq_conservative.c:336:15: warning: symbol 'freq_step' shadows an earlier one
Just rename the local variable.
Signed-off-by: Dave Jones <davej@redhat.com>
* 'for-linus-merged' of master.kernel.org:/home/rmk/linux-2.6-arm:
[ARM] 5177/1: arm/mach-sa1100/Makefile: remove CONFIG_SA1100_USB
[ARM] 5166/1: magician: add MAINTAINERS entry
[ARM] fix pnx4008 build errors
[ARM] Fix SMP booting with non-zero PHYS_OFFSET
[ARM] 5185/1: Fix spi num_chipselect for lubbock
[ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach
[ARM] Add support for arch/arm/mach-*/include and arch/arm/plat-*/include
[ARM] Remove asm/hardware.h, use asm/arch/hardware.h instead
[ARM] Eliminate useless includes of asm/mach-types.h
[ARM] Fix circular include dependency with IRQ headers
avr32: Use <mach/foo.h> instead of <asm/arch/foo.h>
avr32: Introduce arch/avr32/mach-*/include/mach
avr32: Move include/asm-avr32 to arch/avr32/include/asm
[ARM] sa1100_wdt: use reset_status to remember watchdog reset status
[ARM] pxa: introduce reset_status and clear_reset_status for driver's usage
[ARM] pxa: introduce reset.h for reset specific header information
There doesn't seem to be a compelling reason why nfsd4_op_name() is
marked as "inline":
It's only used in a dprintk(), and as long as it has only one caller
non-ancient gcc versions anyway inline it automatically.
This patch fixes the following compile error with gcc 3.4:
...
CC fs/nfsd/nfs4proc.o
nfs4proc.c: In function `nfsd4_proc_compound':
nfs4proc.c:854: sorry, unimplemented: inlining failed in call to
nfs4proc.c:897: sorry, unimplemented: called from here
make[3]: *** [fs/nfsd/nfs4proc.o] Error 1
Reported-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
[ Also made it "const char *" - Linus]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (99 commits)
pkt_sched: Fix actions referencing
bnx2x: fix logical op
tcp: (whitespace only) fix confusing indentation
pkt_sched: Fix qdisc config when link is down.
[Bluetooth] Add full quirk implementation for btusb driver
[Bluetooth] Removal of unnecessary ignore module parameter
[Bluetooth] Add parameters to control BNEP header compression
ath9k: Revamp wireless mode usage
ath9k: More unused macros
ath9k: Remove a few unused macros and fix indentation
ath9k: Use mac80211's band macros and remove enum hal_freq_band
ath9k: Remove redundant data structure ath9k_txq_info
ath9k: Cleanup data structures related to HW capabilities
ath9k: work around gcc ICEs
ath9k: Add new Atheros IEEE 802.11n driver
ath5k: remove Atheros 11n devices from supported list
list.h: add list_cut_position()
list.h: Add list_splice_tail() and list_splice_tail_init()
p54: swap short slot time dcf values
rt2x00: Block all unsupported modes
...
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
sparc64: Fix end-of-stack checking in save_stack_trace().
sparc: don't use asm/of_device.h
sparc64: Use kernel/uid16.c helpers instead of own copy.
of/sparc: remove include of linux/of_platform.h from asm/of_platform.h
sparc: i8042-sparcio.h: fix warning
Back when .gitignore file was added to arch/powerpc/ in 06f2138 ([POWERPC]
Add files build to .gitignore, 2006-11-26), there indeed was nothing
tracked in the ignored hierarchy and ignoring everything made sense. But
we have very many tracked files there these days, and having a higher
level .gitignore that ignores everything is asking for future troubles..
This should have been part of b8b572e (powerpc: Move include files to
arch/powerpc/include/asm, 2008-08-01).
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch removes the commented out line for the not available
CONFIG_SA1100_USB option.
Reported-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Acked-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
include/linux/i2c-pnx.h was missed when moving the include files.
Fix it now; it doesn't really need to include mach/i2c.h at all.
Successfully build tested with pnx4008_defconfig, which had
failed in linux-next.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Bug reported by Alexander Beregalov.
Before we dereference the stack frame or try to peek at the
pt_regs magic value, make sure the entire object is within
the kernel stack bounds.
Signed-off-by: David S. Miller <davem@davemloft.net>
When an action is added several times with the same exact index
it gets deleted on every even-numbered attempt.
This fixes that issue.
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix dubious logical operation that was found by sparse:
linux-next-20080807/drivers/net/bnx2x_main.c:7205:27: warning: dubious: !x & y
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The indentation in part of tcp_minisocks makes it look like one of the if
statements is much more important than it actually is.
Signed-off-by: Adam Langley <agl@imperialviolet.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
IB/mad: Test ib_create_send_mad() return with IS_ERR(), not == NULL
IB/mlx4: Allow 4K messages for UD QPs
mlx4_core: Add ethernet fields to CQE struct
IB/ipath: Fix printk format warnings
RDMA/cxgb3: Fix deadlock initializing iw_cxgb3 device
RDMA/cxgb3: Fix up MW access rights
RDMA/cxgb3: Fix QP capabilities
RDMA/cma: Remove padding arrays by using struct sockaddr_storage
IB/ipath: Use unsigned long for irq flags
IPoIB/cm: Set correct SG list in ipoib_cm_init_rx_wr()
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
xen-blkfront.c: make blkif_ioctl() static
bio: make use of bvec_nr_vecs
cciss: fix bug if scsi tape support is disabled
cciss: add support for multi lun tape devices
cciss: change the way we notify scsi midlayer of tape drives
cciss: fix negative logical drive count in procfs
cciss: remove redundant code
cciss: make rebuild_lun_table behave better
cciss: return -EFAULT if copy_from_user() fails
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
ALSA: ASoC: fix SNDCTL_DSP_SYNC support in Freescale 8610 sound drivers
Looks like somebody didn't get enough sleep.
Noticed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This driver was declared obsolete over 2 years ago, the alternative
console driver for legacy iSeries (hvc_iseries) was made the default
over 1 year ago and this driver has been build broken for over 3
months, so remove it.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb: (23 commits)
V4L/DVB (8617): uvcvideo: don't use stack-based buffers for USB transfers.
V4L/DVB (8616): uvcvideo: Add support for two Bison Electronics webcams
V4L/DVB (8611): Add suspend/resume to pxa_camera driver
V4L/DVB (8610): Add suspend/resume capabilities to soc_camera.
V4L/DVB (8609): media: Clean up platform_driver_unregister() bogosity.
V4L/DVB (8607): cxusb: fix OOPS and broken tuning regression on FusionHDTV Dual Digital 4
V4L/DVB (8605): gspca: Fix of gspca_zc3xx oops - 2.6.27-rc1
V4L/DVB (8604): gspca: Fix of "scheduling while atomic" crash.
V4L/DVB (8602): gspca: Fix small bugs, simplify and cleanup ov519.
V4L/DVB (8582): set mts_firmware for em2882 based Pinnacle Hybrid Pro
V4L/DVB (8574): gspca: Bad bytesperlines of pixelformat in spca505/506/508 and vc023x.
V4L/DVB (8573): gspca: Bad scan of frame in spca505/506/508.
V4L/DVB (8572): gspca: Webcam 0c45:6143 in documentation.
V4L/DVB (8571): gspca: Don't use CONFIG_VIDEO_ADV_DEBUG as a compile option.
V4L/DVB (8569): gspca: Set back the old values of Sonix sn9c120 and cleanup source.
V4L/DVB (8567): gspca: hflip and vflip controls added for ov519 - ov7670 plus init cleanup.
V4L/DVB (8564): fix vino driver build error
V4L/DVB (8563): fix drivers/media/video/arv.c compilation
V4L/DVB (8562): DVB_DRX397XD: remove FW_LOADER select
V4L/DVB (8558): media/video/Kconfig: fix a typo
...
* 'hwmon-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6:
hwmon: (it87) Support for 16-bit fan reading in it8705 >= rev 0x03
hwmon: (it87) Support for 16-bit fan reading in it8712 >= rev 0x07
hwmon: (hwmon-vid) Add 6-bit vid codes for AMD NPT 0Fh cpus
hwmon: (hwmon-vid) Trivial format multi-line comments per CodingStyle
hwmon: ad7414 driver
hwmon: (thmc50) Add support for critical temperature limits
hwmon: (adm9240) Remove EXPERIMENTAL dependency
hwmon: (w83627hf) Drop reset module parameter
hwmon: (w83627hf) Add pwm_enable sysfs interface
hwmon: (w83791d) Use fan divisor bits from vbat register
hwmon: (f71882fg) Delete needless forward declarations
hwmon: (dme1737) Add support for the SMSC SCH5027
hwmon: (dme1737) Skip detection if forced
hwmon: (dme1737) Cleanups
