fork() clones all thread_info flags, including
TIF_USER_RETURN_NOTIFY; if the new task is first scheduled on a cpu
which doesn't have user return notifiers set, this causes user
return notifiers to trigger without any way of clearing itself.

This is easy to trigger with a forky workload on the host in
parallel with kvm, resulting in a cpu in an endless loop on the
verge of returning to userspace.

Fix by dropping the TIF_USER_RETURN_NOTIFY immediately after fork.

Signed-off-by: Avi Kivity <avi@redhat.com>
LKML-Reference: <1259505288-16559-1-git-send-email-avi@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Today's linux-next build (x86_64 allmodconfig) failed like this:

  kernel/user-return-notifier.c: In function
  'fire_user_return_notifiers': kernel/user-return-notifier.c:45:
  error: expected expression before ')' token

Introduced by commit 7c68af6e
("core, x86: Add user return notifiers") from the tip and kvm trees
but revealed by commit e0fdb0e0
("percpu: add __percpu for sparse") from the percpu tree.

Before that percpu tree commit, "put_cpu_var()" would compile
without error (even though it really needs a parameter).

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Avi Kivity <avi@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Lameter <cl@linux-foundation.org>
LKML-Reference: <20091102161722.eea4358d.sfr@canb.auug.org.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

When CONFIG_USER_RETURN_NOTIFIER is set, we need to link
kernel/user-return-notifier.o.

Signed-off-by: Avi Kivity <avi@redhat.com>
LKML-Reference: <1256473485-23109-1-git-send-email-avi@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Add a general per-cpu notifier that is called whenever the kernel is
about to return to userspace.  The notifier uses a thread_info flag
and existing checks, so there is no impact on user return or context
switch fast paths.

This will be used initially to speed up KVM task switching by lazily
updating MSRs.

Signed-off-by: Avi Kivity <avi@redhat.com>
LKML-Reference: <1253342422-13811-1-git-send-email-avi@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
  ax25: Fix possible oops in ax25_make_new
  net: restore tx timestamping for accelerated vlans
  Phonet: fix mutex imbalance
  sit: fix off-by-one in ipip6_tunnel_get_prl
  net: Fix sock_wfree() race
  net: Make setsockopt() optlen be unsigned.

In ax25_make_new, if kmemdup of digipeat returns an error, there would
be an oops in sk_free while calling sk_destruct, because sk_protinfo
is NULL at the moment; move sk->sk_destruct initialization after this.

BTW of reported-by: Bernard Pidoux F6BVP <f6bvp@free.fr>

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since commit 9b22ea56
( net: fix packet socket delivery in rx irq handler )

We lost rx timestamping of packets received on accelerated vlans.

Effect is that tcpdump on real dev can show strange timings, since it gets rx timestamps
too late (ie at skb dequeueing time, not at skb queueing time)

14:47:26.986871 IP 192.168.20.110 > 192.168.20.141: icmp 64: echo request seq 1
14:47:26.986786 IP 192.168.20.141 > 192.168.20.110: icmp 64: echo reply seq 1

14:47:27.986888 IP 192.168.20.110 > 192.168.20.141: icmp 64: echo request seq 2
14:47:27.986781 IP 192.168.20.141 > 192.168.20.110: icmp 64: echo reply seq 2

14:47:28.986896 IP 192.168.20.110 > 192.168.20.141: icmp 64: echo request seq 3
14:47:28.986780 IP 192.168.20.141 > 192.168.20.110: icmp 64: echo reply seq 3

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

From: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>

port_mutex was unlocked twice.

Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When requesting all prl entries (kprl.addr == INADDR_ANY) and there are
more prl entries than there is space passed from userspace, the existing
code would always copy cmax+1 entries, which is more than can be handled.

This patch makes the kernel copy only exactly cmax entries.

Signed-off-by: Sascha Hlusiak <contact@saschahlusiak.de>
Acked-By: Fred L. Templin <Fred.L.Templin@boeing.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 2b85a34e
(net: No more expensive sock_hold()/sock_put() on each tx)
opens a window in sock_wfree() where another cpu
might free the socket we are working on.

A fix is to call sk->sk_write_space(sk) while still
holding a reference on sk.

Reported-by: Jike Song <albcamus@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This provides safety against negative optlen at the type
level instead of depending upon (sometimes non-trivial)
checks against this sprinkled all over the the place, in
each and every implementation.

Based upon work done by Arjan van de Ven and feedback
from Linus Torvalds.

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

Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched_clock: Fix atomicity/continuity bug by using cmpxchg64()
  x86: Provide an alternative() based cmpxchg64()

Commit def0a9b2 (sched_clock: Make it NMI safe) assumed
cmpxchg() of 64bit values was available on X86_32.

That is not so - and causes some subtle scheduler misbehavior due
to incorrect timestamps off to up by ~4 seconds.

Two symptoms are known right now:

 - interactivity problems seen by Arjan: up to 600 msecs
   latencies instead of the expected 20-40 msecs. These
   latencies are very visible on the desktop.

 - incorrect CPU stats: occasionally too high percentages in 'top',
   and crazy CPU usage stats.

Reported-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090930170754.0886ff2e@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

cmpxchg64() today generates, to quote Linus, "barf bag" code.

cmpxchg64() is about to get used in the scheduler to fix a bug there,
but it's a prerequisite that cmpxchg64() first be made non-sucking.

This patch turns cmpxchg64() into an efficient implementation that
uses the alternative() mechanism to just use the raw instruction on
all modern systems.

Note: the fallback is NOT smp safe, just like the current fallback
is not SMP safe. (Interested parties with i486 based SMP systems
are welcome to submit fix patches for that.)

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
[ fixed asm constraint bug ]
Fixed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090930170754.0886ff2e@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  MIPS: Avoid spurious make includecheck message
  MIPS: VPE: Get rid of BKL.
  MIPS: VPE: Fix build after the credential changes a while ago.
  MIPS: Excite: Get rid of BKL.
  MIPS: Sibyte: Get rid of BKL.
  MIPS: BCM63xx: Add PCMCIA & Cardbus support.
  MIPS: MSP71xx: request_irq() failure ignored in msp_pcibios_config_access()
  MIPS: Decrease size of au1xxx_dbdma_pm_regs[][]
  MIPS: SMP: Inline arch_send_call_function_{single_ipi,ipi_mask}
  MIPS: SMP: Fix build.
  MIPS: MIPSxx SC: Avoid destructive invalidation on partial L2 cachelines.
  MIPS: Sibyte: Fix compilation error.
  MIPS: BCM1480: Re-apply patch lost due to bad resolution of merge conflict.
  MIPS: BCM63xx: Add serial driver for bcm63xx integrated UART.
  MIPS: Loongson2: Fix typo "enalbe" -> "enable"
  MIPS: SMTC: Remove duplicate structure field initialization
  MIPS: Remove duplicated #include
  MIPS: BCM63xx: Remove duplicated #include

arch/mips/include/asm/unaligned.h: linux/unaligned/generic.h is included more than once.

Entirely legitimate but just noise.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

It's not obvious what good it was supposed to do here anyway.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Produce an error if request_irq() fails.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: "Ithamar R. Adema" <ithamar.adema@team-embedded.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

There are 16 individual channels (NUM_DBDMA_CHANS) to save/restore plus the
global ddma block config (the +1).  The last register in a channel can be
skipped since it's read-only (at offset 0x18).

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Manuel Lauss <manuel.lauss@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

commit 48a048fe
Author: Rusty Russell <rusty@rustcorp.com.au>
Date:   Thu Sep 24 09:34:44 2009 -0600

apparently only passed the "looks good" level of QA ;-)

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

This extends commit a8ca8b64 to cover
MIPSxx-style board cache code.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Build error introduced by d4f587c6.

Signed-off-by: Mark Mason <mmason@upwardaccess.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Patch 14275ccdb1e4b487cca745aba994699c426a31ee and
d5dedd45 are conflicting and the
conflict was resolved badly in merge
92241940be501f798cb21db344bbb3d1ec3c4f1c resulting in the BCM1480 changes
of 14275ccdb1e4b487cca745aba994699c426a31ee getting lost.  Sort out the
damage.

Reported and initial patch by Mark Mason <mmason@upwardaccess.com>.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Yanhua <yanh@lemote.com>
Cc: Robert Richter <robert.richter@amd.com>
Acked-by: Wu Zhangjin <wuzj@lemote.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

The definition of the irq_ipi structure has two initializations of the
flags field.  This combines them.

[Ralf: The issue was originally introduced by commit
be4894196d79455f420dd7bb78be7dc73bec115c (linux-mips.org) rsp.
033890b0 (kernel.org).  The original
intention of the code was to initialize .flags with both flags ored together.
The broken C code as actually implemented will be compiled by an equally
broken gcc to use only the last initialization, that is IRQF_PERCPU
which means this turned into an SMTC bug for 2.6.23 and newer.]

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/

)

// <smpl>
@r@
identifier I, s, fld;
position p0,p;
expression E;
@@

struct I s =@p0 { ... .fld@p = E, ...};

@s@
identifier I, s, r.fld;
position r.p0,p;
expression E;
@@

struct I s =@p0 { ... .fld@p = E, ...};

@script:python@
p0 << r.p0;
fld << r.fld;
ps << s.p;
pr << r.p;
@@

if int(ps[0].line)!=int(pr[0].line) or int(ps[0].column)!=int(pr[0].column):
  cocci.print_main(fld,p0)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Remove duplicated #include in arch/mips/kernel/smp.c.

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Remove duplicated #include in arch/mips/bcm63xx/boards/board_bcm963xx.c.

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
  nilfs2: fix missing initialization of i_dir_start_lookup member
  nilfs2: fix missing zero-fill initialization of btree node cache

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: Fix time encoding with extra epoch bits
  ext4: Add a stub for mpage_da_data in the trace header
  jbd2: Use tracepoints for history file
  ext4: Use tracepoints for mb_history trace file
  ext4, jbd2: Drop unneeded printks at mount and unmount time
  ext4: Handle nested ext4_journal_start/stop calls without a journal
  ext4: Make sure ext4_dirty_inode() updates the inode in no journal mode
  ext4: Avoid updating the inode table bh twice in no journal mode
  ext4: EXT4_IOC_MOVE_EXT: Check for different original and donor inodes first
  ext4: async direct IO for holes and fallocate support
  ext4: Use end_io callback to avoid direct I/O fallback to buffered I/O
  ext4: Split uninitialized extents for direct I/O
  ext4: release reserved quota when block reservation for delalloc retry
  ext4: Adjust ext4_da_writepages() to write out larger contiguous chunks
  ext4: Fix hueristic which avoids group preallocation for closed files
  ext4: Use ext4_msg() for ext4_da_writepage() errors
  ext4: Update documentation about quota mount options

* git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6:
  fat: Check s_dirt in fat_sync_fs()
  vfat: change the default from shortname=lower to shortname=mixed
  fat/nls: Fix handling of utf8 invalid char

* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  PM / yenta: Fix cardbus suspend/resume regression
  PM / PCMCIA: Drop second argument of pcmcia_socket_dev_suspend()

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (33 commits)
  sony-laptop: re-read the rfkill state when resuming from suspend
  sony-laptop: check for rfkill hard block at load time
  wext: add back wireless/ dir in sysfs for cfg80211 interfaces
  wext: Add bound checks for copy_from_user
  mac80211: improve/fix mlme messages
  cfg80211: always get BSS
  iwlwifi: fix 3945 ucode info retrieval after failure
  iwlwifi: fix memory leak in command queue handling
  iwlwifi: fix debugfs buffer handling
  cfg80211: don't set privacy w/o key
  cfg80211: wext: don't display BSSID unless associated
  net: Add explicit bound checks in net/socket.c
  bridge: Fix double-free in br_add_if.
  isdn: fix netjet/isdnhdlc build errors
  atm: dereference of he_dev->rbps_virt in he_init_group()
  ax25: Add missing dev_put in ax25_setsockopt
  Revert "sit: stateless autoconf for isatap"
  net: fix double skb free in dcbnl
  net: fix nlmsg len size for skb when error bit is set.
  net: fix vlan_get_size to include vlan_flags size
  ...

* 'drm-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (25 commits)
  drm/radeon/kms: Convert R520 to new init path and associated cleanup
  drm/radeon/kms: Convert RV515 to new init path and associated cleanup
  drm: fix radeon DRM warnings when !CONFIG_DEBUG_FS
  drm: fix drm_fb_helper warning when !CONFIG_MAGIC_SYSRQ
  drm/r600: fix memory leak introduced with 64k malloc avoidance fix.
  drm/kms: make fb helper work for all drivers.
  drm/radeon/r600: fix offset handling in CS parser
  drm/radeon/kms/r600: fix forcing pci mode on agp cards
  drm/radeon/kms: fix for the extra pages copying.
  drm/radeon/kms/r600: add support for vline relocs
  drm/radeon/kms: fix some bugs in vline reloc
  drm/radeon/kms/r600: clamp vram to aperture size
  drm/kms: protect against fb helper not being created.
  drm/r600: get values from the passed in IB not the copy.
  drm: create gitignore file for radeon
  drm/radeon/kms: remove unneeded master create/destroy functions.
  drm/kms: start adding command line interface using fb.
  fb: change rules for global rules match.
  drm/radeon/kms: don't require up to 64k allocations. (v2)
  drm/radeon/kms: enable dac load detection by default.
  ...

Trivial conflicts in drivers/gpu/drm/radeon/radeon_asic.h due to adding
'->vga_set_state' function pointers.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: make allocation failures more verbose
  percpu: make pcpu_setup_first_chunk() failures more verbose
  percpu: make embedding first chunk allocator check vmalloc space size
  sparc64: implement page mapping percpu first chunk allocator
  percpu: make pcpu_build_alloc_info() clear static buffers
  percpu: fix unit_map[] verification in pcpu_setup_first_chunk()