We found this issue last week w/ the -RT kernel, but it seems the same
issue is in mainline as well.

Basically it is possible for futex_unlock_pi to return without actually
freeing the lock.  This is due to buggy logic in the use of
futex_handle_fault() and its attempt argument in a failure case.

Looking at futex.c the logic is as follows:

1) In futex_unlock_pi() we start w/ ret=0 and we go down to the first
   futex_atomic_cmpxchg_inatomic(), where we find uval==-EFAULT.  We then
   jump to the pi_faulted label.

2) From pi_faulted: We increment attempt, unlock the sem and hit the
   retry label.

3) From the retry label, with ret still zero, we again hit EFAULT on the
   first futex_atomic_cmpxchg_inatomic(), and again goto the pi_faulted
   label.

4) Again from pi_faulted: we increment attempt and enter the
   conditional, where we call futex_handle_fault.

5) futex_handle_fault fails, and we goto the out_unlock_release_sem
   label.

6) From out_unlock_release_sem we return, and since ret is still zero,
   we return without error, while never actually unlocking the lock.

Issue #1: at the first futex_atomic_cmpxchg_inatomic() we should probably
be setting ret=-EFAULT before jumping to pi_faulted: However in our case
this doesn't really affect anything, as the glibc we're using ignores the
error value from futex_unlock_pi().

Issue #2: Look at futex_handle_fault(), its first conditional will return
-EFAULT if attempt is >= 2.  However, from the "if(attempt++)
futex_handle_fault(attempt)" logic above, we'll *never* call
futex_handle_fault when attempt is less then two.  So we never get a chance
to even try to fault the page in.

The following patch addresses these two issues by 1) Always setting ret to
-EFAULT if futex_handle_fault fails, and 2) Removing the = in
futex_handle_fault's (attempt >= 2) check.

I'm really not sure this is the right fix, but wanted to bring it up so
folks knew the issue is alive and well in the current -git tree.  From
looking at the git logs the logic was first introduced (then later copied
to other places) in the following commit almost a year ago:

http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=4732efbeb997189d9f9b04708dc26bf8613ed721;hp=5b039e681b8c5f30aac9cc04385cc94be45d0823

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

sys_getppid() optimization can access a freed memory.  On kernels with
DEBUG_SLAB turned ON, this results in Oops.  As Dave Hansen noted, this
optimization is also unsafe for memory hotplug.

So this patch always takes the lock to be safe.

[oleg@tv-sign.ru: simplifications]
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Cc: <stable@kernel.org>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Previously the message was "Fatal exception: panic_on_oops", as introduced
in a recent patch whith removed a somewhat dangerous call to ssleep() in
the panic_on_oops path.  However, Paul Mackerras suggested that this was
somewhat confusing, leadind people to believe that it was panic_on_oops
that was the root cause of the fatal exception.  On his suggestion, this
patch changes the message to simply "Fatal exception".  A suitable oops
message should already have been displayed.
Signed-off-by: Simon Horman <horms@verge.net.au>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Fix BUG I tripped on while testing failover and multipathing.

BUG shows up on error path in multipath_ctr() when parse_priority_group()
fails after returning at least once without error.  The fix is to
initialize m->ti early - just after alloc()ing it.

BUG: unable to handle kernel NULL pointer dereference at virtual address 00000000
 printing eip:
c027c3d2
*pde = 00000000
Oops: 0000 [#3]
Modules linked in: qla2xxx ext3 jbd mbcache sg ide_cd cdrom floppy
CPU:    0
EIP:    0060:[<c027c3d2>]    Not tainted VLI
EFLAGS: 00010202   (2.6.17.3 #1)
EIP is at dm_put_device+0xf/0x3b
eax: 00000001   ebx: ee4fcac0   ecx: 00000000   edx: ee4fcac0
esi: ee4fc4e0   edi: ee4fc4e0   ebp: 00000000   esp: c5db3e78
ds: 007b   es: 007b   ss: 0068
Process multipathd (pid: 15912, threadinfo=c5db2000 task=ef485a90)
Stack: ec4eda40 c02816bd ee4fc4c0 00000000 f7e89498 f883e0bc c02816f6 f7e89480
       f7e8948c c0281801 ffffffea f7e89480 f883e080 c0281ffe 00000001 00000000
       00000004 dfe9cab8 f7a693c0 f883e080 f883e0c0 ca4b99c0 c027c6ee 01400000
Call Trace:
 <c02816bd> free_pgpaths+0x31/0x45  <c02816f6> free_priority_group+0x25/0x2e
 <c0281801> free_multipath+0x35/0x67  <c0281ffe> multipath_ctr+0x123/0x12d
 <c027c6ee> dm_table_add_target+0x11e/0x18b  <c027e5b4> populate_table+0x8a/0xaf
 <c027e62b> table_load+0x52/0xf9  <c027ec23> ctl_ioctl+0xca/0xfc
 <c027e5d9> table_load+0x0/0xf9  <c0152146> do_ioctl+0x3e/0x43
 <c0152360> vfs_ioctl+0x16c/0x178  <c01523b4> sys_ioctl+0x48/0x60
 <c01029b3> syscall_call+0x7/0xb
Code: 97 f0 00 00 00 89 c1 83 c9 01 80 e2 01 0f 44 c1 88 43 14 8b 04 24 59 5b 5e 5f 5d c3 53 89 c1 89 d3 ff 4a 08 0f 94 c0 84 c0 74 2a <8b> 01 8b 10 89 d8 e8 f6 fb ff ff 8b 03 8b 53 04 89 50 04 89 02
EIP: [<c027c3d2>] dm_put_device+0xf/0x3b SS:ESP 0068:c5db3e78
Signed-off-by: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Acked-by: Alasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

kernel/panic.c: In function 'add_taint':
kernel/panic.c:176: warning: implicit declaration of function 'debug_locks_off'

Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

The percpu variable is used incorrectly in switch_hrtimer_base().
Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Eric says:

> I saw an oops down this path when trying to create a new file on a UDF
> filesystem which was internally marked as readonly, but mounted rw:
>
> udf_create
>         udf_new_inode
>                 new_inode
>                         alloc_inode
>                         	udf_alloc_inode
>                 udf_new_block
>                         returns EIO due to readonlyness
>                 iput (on error)

I ran into the same issue today, but when listing a directory with
invalid/corrupt entries:

udf_lookup
        udf_iget
                get_new_inode_fast
                        alloc_inode
                                udf_alloc_inode
                __udf_read_inode
                        fails for any reason
                iput (on error)
                        ...

The following patch to udf_alloc_inode() should take care of both (and
other similar) cases, but I've only tested it with udf_lookup().
Signed-off-by: Dan Bastone <dan@pwienterprises.com>
Cc: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Don't use NULL as a printf control string.  Fixes bug #6889.

Cc: Ralph Corderoy <ralph@inputplus.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Add basic Machine detection to imacfb and some Ducumentation bits for
imacfb.
Signed-off-by: Edgar Hucek <hostmaster@ed-soft.at>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

The IPv4/IPv6 datagram output path was using skb_trim to trim paged
packets because they know that the packet has not been cloned yet
(since the packet hasn't been given to anything else in the system).

This broke because skb_trim no longer allows paged packets to be
trimmed.  Paged packets must be given to one of the pskb_trim functions
instead.

This patch adds a new pskb_trim_unique function to cover the IPv4/IPv6
datagram output path scenario and replaces the corresponding skb_trim
calls with it.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix kernel panic on various SMP machines. The culprit is a null
ub->skb in ulog_send(). If ulog_timer() has already been scheduled on
one CPU and is spinning on the lock, and ipt_ulog_packet() flushes the
queue on another CPU by calling ulog_send() right before it exits,
there will be no skbuff when ulog_timer() acquires the lock and calls
ulog_send(). Cancelling the timer in ulog_send() doesn't help because
it has already been scheduled and is running on the first CPU.

Similar problem exists in ebt_ulog.c and nfnetlink_log.c.
Signed-off-by: Mark Huang <mlhuang@cs.princeton.edu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Neither of {arp,ip,ip6}_tables cleans up behind itself when something goes
wrong during initialization.

Noticed by Rennie deGraaf <degraaf@cpsc.ucalgary.ca>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix from Aji_Srinivas@emc.com, STP packets are incorrectly received on
all LLC datagram sockets, whichever interface they are bound to.  The
llc_sap datagram receive logic sends packets with a unicast
destination MAC to one socket bound to that SAP and MAC, and multicast
packets to all sockets bound to that SAP. STP packets are multicast,
and we do need to know on which interface they were received.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

If dst->obsolete is -1, this is a signal from the
bundle creator that we want the XFRM dst and the
dsts that it references to be validated on every
use.

I misunderstood this intention when I changed
xfrm_dst_check() to always return NULL.

Now, when we purge a dst entry, by running dst_free()
on it.  This will set the dst->obsolete to a positive
integer, and we want to return NULL in that case so
that the socket does a relookup for the route.

Thus, if dst->obsolete<0, let stale_bundle() validate
the state, else always return NULL.

In general, we need to do things more intelligently
here because we flush too much state during rule
changes.  Herbert Xu has some ideas wherein the key
manager gives us some help in this area.  We can also
use smarter state management algorithms inside of
the kernel as well.
Signed-off-by: David S. Miller <davem@davemloft.net>

Hashlimit doesn't account for the first packet, which is inconsistent
with the limit match.

Reported by ryan.castellucci@gmail.com, netfilter bugzilla #500.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

The xt_string match is broken with ! negation.
This resolves a portion of netfilter bugzilla #497.
Signed-off-by: Phil Oester <kernel@linuxace.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Somehow I clobbered James's original fix and only my
subsequent compiler warning change went in for that
changeset.

Get the real fix in there.

Noticed by Jesper Juhl.
Signed-off-by: David S. Miller <davem@davemloft.net>

In my quest to try and figure out why test 14 (control write) doesn't
work with my EZ-USB board, I noticed that sometimes testusb reported
no error even though the kernel log complained "byte 0 is 0 not 2" etc.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: Jonathan Davies <jjd27@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

I write a patch for ipaq.c.
Would you like to add upstream tree ?

This patch enables a support of "SHARP W-ZERO3(WS004SH)" and "SHARP W-ZERO3[es](WS007SH)".

From: Norihiko Tomiyama <norihiko.tomiyama@ctc-g.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

appletouch uses urb->transfer_dma after having freed the urb, this shows
up only if the system is compiled with slab debugging. This patch fixes
it by reordering the free calls.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Vojtech Pavlik <vojtech@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

This patch has removed a unbalanced #endif from ohci-au1xxx.c .
Please apply before 2.6.18 release.

Error message was:
In file included from drivers/usb/host/ohci-hcd.c:909:
drivers/usb/host/ohci-au1xxx.c:113:2: #endif without #if
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

This patch (as763) adds an unusual_devs entry for the A-VOX WSX-300ER MP3
player.

From: David Kuehling <dvdkhlng@gmx.de>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Nothing in the tree references this config option.
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Make pciehp build on powerpc
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

pr_debug() should not be used from drivers, add comment saying that.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

block/genhd.c no longer in drivers/.  Update Documentation/kobjects.txt
Signed-off-by: Brandon Philips <brandon@ifup.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

While helping someone to submit a patch to the stable branch, I noticed
that the stable branch is not listed in the MAINTAINERS file.  This was
after I went there to look for the email addresses for the stable branch
list (stable@kernel.org).

This patch adds the stable branch to the maintainers file so that people
can find where to send patches when they have a fix for the stable team.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

We recently fixed an out-of-space deadlock in XFS, and part of that fix
involved the addition of the XFS_ALLOC_FLAG_FREEING flag to some of the
space allocator calls to indicate they're freeing space, not allocating
it. There was a missed xfs_alloc_fix_freelist condition test that did not
correctly test "flags". The same test would also test an uninitialised
structure field (args->userdata) and depending on its value either would
or would not return early with a critical buffer pointer set to NULL.

This fixes that up, adds asserts to several places to catch future botches
of this nature, and skips sections of xfs_alloc_fix_freelist that are
irrelevent for the space-freeing case.

SGI-PV: 955303
SGI-Modid: xfs-linux-melb:xfs-kern:26743a
Signed-off-by: Nathan Scott <nathans@sgi.com>

Noticed by Dave Jones.
Signed-off-by: David S. Miller <davem@davemloft.net>

The ifa lock is expected to be taken in BH context (by addrconf timers)
so we must disable BH when accessing it from user context.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

When the IDE fix for Jmicron went in one piece went walking somewhere
(send log shows my end somehow). Without this sometimes you get an oops
on boot.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Merge branch 'upstream-greg' of gregkh@master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/netdev-2.6

Merge branch 'upstream-greg' of gregkh@master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev

Patch from Dmitry Mishin <dim@openvz.org>:

Replace add_timer() by mod_timer() in dst_run_gc
in order to avoid BUG message.

       CPU1                            CPU2
dst_run_gc()  entered           dst_run_gc() entered
spin_lock(&dst_lock)                   .....
del_timer(&dst_gc_timer)         fail to get lock
       ....                         mod_timer() <--- puts 
                                                 timer back
                                                 to the list
add_timer(&dst_gc_timer) <--- BUG because timer is in list already.

Found during OpenVZ internal testing.

At first we thought that it is OpenVZ specific as we
added dst_run_gc(0) call in dst_dev_event(),
but as Alexey pointed to me it is possible to trigger
this condition in mainstream kernel.

F.e. timer has fired on CPU2, but the handler was preeempted
by an irq before dst_lock is tried.
Meanwhile, someone on CPU1 adds an entry to gc list and
starts the timer.
If CPU2 was preempted long enough, this timer can expire
simultaneously with resuming timer handler on CPU1, arriving
exactly to the situation described.
Signed-off-by: Dmitry Mishin <dim@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>

SCSI EH locks door if sdev->locked is set.  Sometimes door lock
command fails continuously (e.g. when medium is not present) and as
libata uses EH to acquire sense data, this easily creates a loop where
a failed lock door invokes EH and EH issues lock door on completion.

This patch clears sdev->locked on door lock failure to break this
loop.  This problem has been spotted and diagnosed by Unicorn Chang
<uchang@tw.ibm.com>.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>