radix_tree_tag_get() is not safe to use concurrently with radix_tree_tag_set()
or radix_tree_tag_clear(). The problem is that the double tag_get() in
radix_tree_tag_get():
if (!tag_get(node, tag, offset))
saw_unset_tag = 1;
if (height == 1) {
int ret = tag_get(node, tag, offset);
may see the value change due to the action of set/clear. RCU is no protection
against this as no pointers are being changed, no nodes are being replaced
according to a COW protocol - set/clear alter the node directly.
The documentation in linux/radix-tree.h, however, says that
radix_tree_tag_get() is an exception to the rule that "any function modifying
the tree or tags (...) must exclude other modifications, and exclude any
functions reading the tree".
The problem is that the next statement in radix_tree_tag_get() checks that the
tag doesn't vary over time:
BUG_ON(ret && saw_unset_tag);
This has been seen happening in FS-Cache:
https://www.redhat.com/archives/linux-cachefs/2010-April/msg00013.html
To this end, remove the BUG_ON() from radix_tree_tag_get() and note in various
comments that the value of the tag may change whilst the RCU read lock is held,
and thus that the return value of radix_tree_tag_get() may not be relied upon
unless radix_tree_tag_set/clear() and radix_tree_delete() are excluded from
running concurrently with it.
Reported-by: Romain DEGEZ <romain.degez@smartjog.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As suggested by Linus, fix up kmem_ptr_validate() to handle non-kernel pointers
more graciously. The patch changes kmem_ptr_validate() to use the newly
introduced kern_ptr_validate() helper to check that a pointer is a valid kernel
pointer before we attempt to convert it into a 'struct page'.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As suggested by Linus, introduce a kern_ptr_validate() helper that does some
sanity checks to make sure a pointer is a valid kernel pointer. This is a
preparational step for fixing SLUB kmem_ptr_validate().
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit ba168fc37d.
It changes user-visible sysfs interfaces, and breaks some existing user
space applications which apparently rely on the fact that the output
does not contain the "0x" prefix.
Requested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The widget connections of ADC of ALC880 and ALC2260 aren't initialized,
thus it might point to invalid pin. This can be a problem when mode=auto
and there is only one input pin. Then user can't change the connection
at all.
This patch adds the code to initialize the input pin connection of these
codecs.
Reference: Novell bnc#594363
https://bugzilla.novell.com/show_bug.cgi?id=594363
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Write combining/cached device mappings are not setting the shared bit,
which could potentially cause problems on SMP systems since the cache
lines won't participate in the cache coherency protocol.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
The savesys_ipl_nss asm function is put into the .init.text section
however it is missing a ".previous" section which would restore the
previous section.
Luckily all functions in early.c are init functions so it doesn't
matter currently.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The default size of the vmalloc area is currently 1 GB. The memory resource
controller uses about 10 MB of vmalloc space per gigabyte of memory. That
turns a system with more than ~100 GB memory unbootable with the default
vmalloc size. It costs us nothing to increase the default size to some
more adequate value, e.g. 128 GB.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
commit 6a985c6194
([S390] s390: use change recording override for kernel mapping)
deactivated the change bit recording for the kernel mapping to
improve the performance. This works most of the time, but there
are cases (e.g. kernel runs in home space, futex atomic compare xcmg)
where we modify user memory with the kernel mapping instead of the
user mapping.
Instead of fixing these cases, this patch just deactivates change bit
override to avoid future problems with other kernel code that might
use the kernel mapping for user memory.
CC: stable@kernel.org
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If a machine check interrupts the io interrupt handler on one of the
instructions between io_return and io_leave the critical section
cleanup code will move the return psw to io_work_loop. By doing that
the switch from the asynchronous interrupt stack to the process stack
is skipped. If e.g. TIF_NEED_RESCHED is set things break because
the scheduler is called with the asynchronous interrupts stack.
Moving the psw back to io_return instead fixes the problem.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
"len" hasn't been properly range checked so we shouldn't use it as an
array offset. This can only be written to by root but it would still be
annoying to accidentally write more than 3 characters and corrupt your
memory.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
In the default case the lock is not unlocked. The return is
converted to a goto, to share the unlock at the end of the function.
A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@r exists@
expression E1;
identifier f;
@@
f (...) { <+...
* spin_lock_irq (E1,...);
... when != E1
* return ...;
...+> }
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Corrected HP and mic pins for ALC269vb amic and dmic models.
Signed-off-by: Kailang Yang <kailang@realtek.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
ALC269vb has an alternative HP pin 0x21 in addition.
Fix the parser to recognize it.
Signed-off-by: Kailang Yang <kailang@realtek.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
at91 slow-clock resume: Don't wait for a disabled PLL to lock.
We run into this problem with the PLLB on the at91: ohci-at91 disables
the PLLB when going to suspend. The slowclock code however tries to do
the same: It saves the PLLB register value and when restoring the value
during resume, it waits for the PLLB to lock again. However the PLL will
never lock and the loop would run into its timeout because the slowclock
code just stored and restored an empty register.
This fixes the problem by only restoring PLLA/PLLB when they were enabled
at suspend time.
Cc: Andrew Victor <avictor.za@gmail.com>
Signed-off-by: Anders Larsen <al@alarsen.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When CFQ dispatches requests forcefully due to a barrier or changing iosched,
it runs through all cfqq's dispatching requests and then expires each queue.
However, it does not activate a cfqq before flushing its IOs resulting in
using stale values for computing slice_used.
This patch fixes it by calling activate queue before flushing reuqests from
each queue.
This is useful mostly for barrier requests because when the iosched is changing
it really doesnt matter if we have incorrect accounting since we're going to
break down all structures anyway.
We also now expire the current timeslice before moving on with the dispatch
to accurately account slice used for that cfqq.
Signed-off-by: Divyesh Shah<dpshah@google.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* 'nouveau/for-airlied' of ../drm-nouveau-next: (21 commits)
drm/nouveau: bail out of auxch transaction if we repeatedly recieve defers
drm/nv50: implement gpio set/get routines
drm/nv50: parse/use some more de-magiced parts of gpio table entries
drm/nouveau: store raw gpio table entry in bios gpio structs
drm/nv40: Init some tiling-related PGRAPH state.
drm/nv50: Add NVA3 support in ctxprog/ctxvals generator.
drm/nv50: another dodgy DP hack
drm/nv50: punt hotplug irq handling out to workqueue
drm/nv50: preserve an unknown SOR_MODECTRL value for DP encoders
drm/nv50: Allow using the NVA3 new compute class.
drm/nv50: cleanup properly if PDISPLAY init fails
drm/nouveau: fixup the init failure paths some more
drm/nv50: fix instmem init on IGPs if stolen mem crosses 4GiB mark
drm/nv40: add LVDS table quirk for Dell Latitude D620
drm/nv40: rework lvds table parsing
drm/nouveau: detect vram amount once, and save the value
drm/nouveau: remove some unused members from drm_nouveau_private
drm/nouveau: Make use of TTM busy_placements.
drm/nv50: add more 0x100c80 flushy magic
drm/nv50: fix fbcon when framebuffer above 4GiB mark
...
Fixes garbled 3D on an nv46 card.
Reported-by: Francesco Marella <francesco.marella@gmail.com>
Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Allows *some* DP cards to keep working in some corner cases that most
people shouldn't hit. I hit it all the time with development, so this
can stay for now.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
This value interacts with some registers we don't currently know how to
program properly ourselves. The default of 5 that we were using matches
what the VBIOS on early DP cards do, but later ones use 6, which would
cause nouveau to program an incorrect mode on these chips.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
All indications seem to be that the version 0x30 table should be handled
the same way as 0x40 (as used on G80), at least for the parts that we
currently try use.
This commit cleans up the parsing to make it clearer about what we're
actually trying to achieve, and unifies the 0x30/0x40 parsing.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
As opposed to repeatedly reading the amount back from the GPU every
time we need to know the VRAM size.
We should now fail to load gracefully on detecting no VRAM, rather than
something potentially messy happening.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Previously we were filling it the same as "placements", but in some
cases there're valid alternatives that we were ignoring completely.
Keeping a back-up memory type helps on several low-mem situations.
Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Fixes the !vbo_fifo path in the 3D driver on certain chipsets. Still not
really any good idea of what exactly the magic achieves, but it makes
things work.
While we're at it, in the PCIEGART path, flush on unbinding also.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
For 4965, need to check it is valid qos frame before free, only valid
QoS frame has the tid used to free the packets.
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Update mtime when writing to backing filesystem using the address space
operations write_begin and write_end.
Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
not overwriting file_lock structure after GET_LK
cifs: Fix a kernel BUG with remote OS/2 server (try #3)
[CIFS] initialize nbytes at the beginning of CIFSSMBWrite()
[CIFS] Add mmap for direct, nobrl cifs mount types
Back in commit 04a0551c87
("loopback: Drop obsolete ip_summed setting") we stopped
setting CHECKSUM_UNNECESSARY in the loopback xmit.
This is because such a setting was a lie since it implies that the
checksum field of the packet is properly filled in.
Instead what happens normally is that CHECKSUM_PARTIAL is set and
skb->csum is calculated as needed.
But this was only happening for TCP data packets (via the
skb->ip_summed assignment done in tcp_sendmsg()). It doesn't
happen for non-data packets like ACKs etc.
Fix this by setting skb->ip_summed in the common non-data packet
constructor. It already is setting skb->csum to zero.
But this reminds us that we still have things like ip_output.c's
ip_dev_loopback_xmit() which sets skb->ip_summed to the value
CHECKSUM_UNNECESSARY, which Herbert's patch teaches us is not
valid. So we'll have to address that at some point too.
Signed-off-by: David S. Miller <davem@davemloft.net>
Commits 5051ebd275 and
5051ebd275 ("ipv[46]: udp: optimize unicast RX
path") broke some programs.
After upgrading a L2TP server to 2.6.33 it started to fail, tunnels going up an
down, after the 10th tunnel came up. My modified rp-l2tp uses a global
unconnected socket bound to (INADDR_ANY, 1701) and one connected socket per
tunnel after parameter negotiation.
After ten sockets were open and due to mixed parameters to
udp[46]_lib_lookup2() kernel started to drop packets.
Signed-off-by: Jorge Boncompte [DTI2] <jorge@dti2.net>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
libata: Fix accesses at LBA28 boundary (old bug, but nasty) (v2)
Most drives from Seagate, Hitachi, and possibly other brands,
do not allow LBA28 access to sector number 0x0fffffff (2^28 - 1).
So instead use LBA48 for such accesses.
This bug could bite a lot of systems, especially when the user has
taken care to align partitions to 4KB boundaries. On misaligned systems,
it is less likely to be encountered, since a 4KB read would end at
0x10000000 rather than at 0x0fffffff.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6:
ide: Fix IDE taskfile with cfq scheduler
ide: Must hold queue lock when requeueing
ide: Requeue request after DMA timeout
