Peter Zijlstra suggested that we remove USER_SCHED at:

   http://lkml.org/lkml/2009/3/21/67

Removing USER_SCHED removes a lot of code from the scheduler
and simplifies the code.

We already have the ability to do user based classification
which is tightened using PAM in userspace.

Schedule USER_SCHED for removal in 2.6.34
Signed-off-by: NDhaval Giani <dhaval@linux.vnet.ibm.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Bharata B Rao <bharata@linux.vnet.ibm.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
LKML-Reference: <20091103214544.GI5495@linux.vnet.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

cpu_nr_migrations() is not used, remove it.
Signed-off-by: NHiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4AF12A66.6020609@ct.jp.nec.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

time_sync_thresh had been removed.
Signed-off-by: NHiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4AF12A3A.5050200@ct.jp.nec.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

__schedule() had been removed.
Signed-off-by: NHiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4AF129C8.3030008@ct.jp.nec.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

CPU time of a guest is always accounted in 'user' time
without concern for the nice value of its counterpart
process although the guest is scheduled under the nice
value.

This patch fixes the defect and accounts cpu time of
a niced guest in 'nice' time as same as a niced process.

And also the patch adds 'guest_nice' to cpuacct. The
value provides niced guest cpu time which is like 'nice'
to 'user'.

The original discussions can be found here:

  http://www.mail-archive.com/kvm@vger.kernel.org/msg23982.html
  http://www.mail-archive.com/kvm@vger.kernel.org/msg23860.htmlSigned-off-by: NRyota Ozaki <ozaki.ryota@gmail.com>
Acked-by: NAvi Kivity <avi@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1256314810-7897-1-git-send-email-ozaki.ryota@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Conflicts:
	fs/proc/array.c

Merge reason: resolve conflict and queue up dependent patch.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  move virtrng_remove to .devexit.text
  move virtballoon_remove to .devexit.text
  virtio_blk: Revert serial number support
  virtio: let header files include virtio_ids.h
  virtio_blk: revert QUEUE_FLAG_VIRT addition

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (21 commits)
  niu: VLAN_ETH_HLEN should be used to make sure that the whole MAC header was copied to the head buffer in the Vlan packets case
  KS8851: Fix ks8851_set_rx_mode() for IFF_MULTICAST
  KS8851: Fix MAC address write order
  KS8851: Add soft reset at probe time
  net: fix section mismatch in fec.c
  net: Fix struct inet_timewait_sock bitfield annotation
  tcp: Try to catch MSG_PEEK bug
  net: Fix IP_MULTICAST_IF
  bluetooth: static lock key fix
  bluetooth: scheduling while atomic bug fix
  tcp: fix TCP_DEFER_ACCEPT retrans calculation
  tcp: reduce SYN-ACK retrans for TCP_DEFER_ACCEPT
  tcp: accept socket after TCP_DEFER_ACCEPT period
  Revert "tcp: fix tcp_defer_accept to consider the timeout"
  AF_UNIX: Fix deadlock on connecting to shutdown socket
  ethoc: clear only pending irqs
  ethoc: inline regs access
  vmxnet3: use dev_dbg, fix build for CONFIG_BLOCK=n
  virtio_net: use dev_kfree_skb_any() in free_old_xmit_skbs()
  be2net: fix support for PCI hot plug
  ...

The function virtrng_remove is used only wrapped by __devexit_p so define
it using __devexit.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

The function virtballoon_remove is used only wrapped by __devexit_p so
define it using __devexit.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This reverts "Add serial number support for virtio_blk, V4a".

Turns out that virtio_pci, lguest and s/390 all have an 8 bit limit
on virtio config space, so noone could ever use this.

This is coming back later in a cleaner form.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: john cooper <john.cooper@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>

Rusty,

commit 3ca4f5ca
    virtio: add virtio IDs file
moved all device IDs into a single file. While the change itself is
a very good one, it can break userspace applications. For example
if a userspace tool wanted to get the ID of virtio_net it used to
include virtio_net.h. This does no longer work, since virtio_net.h
does not include virtio_ids.h.
This patch moves all "#include <linux/virtio_ids.h>" from the C
files into the header files, making the header files compatible with
the old ones.

In addition, this patch exports virtio_ids.h to userspace.

CC: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

It seems like the addition of QUEUE_FLAG_VIRT caueses major performance
regressions for Fedora users:

	https://bugzilla.redhat.com/show_bug.cgi?id=509383
	https://bugzilla.redhat.com/show_bug.cgi?id=505695

while I can't reproduce those extreme regressions myself I think the flag
is wrong.

Rationale:

  QUEUE_FLAG_VIRT expands to QUEUE_FLAG_NONROT which casus the queue
  unplugged immediately.  This is not a good behaviour for at least
  qemu and kvm where we do have significant overhead for every
  I/O operations.  Even with all the latested speeups (native AIO,
  MSI support, zero copy) we can only get native speed for up to 128kb
  I/O requests we already are down to 66% of native performance for 4kb
  requests even on my laptop running the Intel X25-M SSD for which the
  QUEUE_FLAG_NONROT was designed.
  If we ever get virtio-blk overhead low enough that this flag makes
  sense it should only be set based on a feature flag set by the host.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

niu: VLAN_ETH_HLEN should be used to make sure that the whole MAC header was copied to the head buffer in the Vlan packets case
Signed-off-by: NJoyce Yu <joyce.yu@sun.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

* 'for-linus' of git://git.infradead.org/users/eparis/notify:
  dnotify: ignore FS_EVENT_ON_CHILD
  inotify: fix coalesce duplicate events into a single event in special case
  inotify: deprecate the inotify kernel interface
  fsnotify: do not set group for a mark before it is on the i_list

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: hp_sdc_rtc - fix test in hp_sdc_rtc_read_rt()
  Input: atkbd - consolidate force release quirks for volume keys
  Input: logips2pp - model 73 is actually TrackMan FX
  Input: i8042 - add Sony Vaio VGN-FZ240E to the nomux list
  Input: fix locking issue in /proc/bus/input/ handlers
  Input: atkbd - postpone restoring LED/repeat rate at resume
  Input: atkbd - restore resetting LED state at startup
  Input: i8042 - make pnp_data_busted variable boolean instead of int
  Input: synaptics - add another Protege M300 to rate blacklist

* 'kvm-updates/2.6.32' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: Prevent kvm_init from corrupting debugfs structures
  KVM: MMU: fix pointer cast
  KVM: use proper hrtimer function to retrieve expiration time

* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm:
  dm snapshot: allow chunk size to be less than page size
  dm snapshot: use unsigned integer chunk size
  dm snapshot: lock snapshot while supplying status
  dm exception store: fix failed set_chunk_size error path
  dm snapshot: require non zero chunk size by end of ctr
  dm: dec_pending needs locking to save error value
  dm: add missing del_gendisk to alloc_dev error path
  dm log: userspace fix incorrect luid cast in userspace_ctr
  dm snapshot: free exception store on init failure
  dm snapshot: sort by chunk size to fix race

Increase TEST_SUSPEND_SECONDS to 10 so the warning in
suspend_test_finish() doesn't annoy the users of slower systems so much.

Also, make the warning print the suspend-resume cycle time, so that we
know why the warning actually triggered.

Patch prepared during the hacking session at the Kernel Summit in Tokyo.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This fixes a compile bug introduced in

	6ef297f8 (ARM: 5720/1: Move MMCI header to amba include dir)

That commit moved arch/arm/include/asm/mach/mmc.h to
include/linux/amba/mmci.h.  Just removing the include was enough.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: NLinus Walleij <linus.walleij@stericsson.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NBill Gatliff <bgat@billgatliff.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'sh/for-2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  sh: Kill off stray HAVE_FTRACE_SYSCALLS reference.
  sh: Remove BKL from landisk gio.
  sh: disabled cache handling fix.
  sh: Fix up single page flushing to use PAGE_SIZE.

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: aesni-intel - Fix irq_fpu_usable usage
  crypto: padlock-sha - Fix stack alignment

Fix a (small) memory leak in one of the error paths of the NFS mount
options parsing code.

Regression introduced in 2.6.30 by commit a67d18f8 (NFS: load the
rpc/rdma transport module automatically).
Reported-by: NYinghai Lu <yinghai@kernel.org>
Reported-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch fixes a null pointer exception in pipe_rdwr_open() which
generates the stack trace:

> Unable to handle kernel NULL pointer dereference at 0000000000000028 RIP:
>  [<ffffffff802899a5>] pipe_rdwr_open+0x35/0x70
>  [<ffffffff8028125c>] __dentry_open+0x13c/0x230
>  [<ffffffff8028143d>] do_filp_open+0x2d/0x40
>  [<ffffffff802814aa>] do_sys_open+0x5a/0x100
>  [<ffffffff8021faf3>] sysenter_do_call+0x1b/0x67

The failure mode is triggered by an attempt to open an anonymous
pipe via /proc/pid/fd/* as exemplified by this script:

=============================================================
while : ; do
   { echo y ; sleep 1 ; } | { while read ; do echo z$REPLY; done ; } &
   PID=$!
   OUT=$(ps -efl | grep 'sleep 1' | grep -v grep |
        { read PID REST ; echo $PID; } )
   OUT="${OUT%% *}"
   DELAY=$((RANDOM * 1000 / 32768))
   usleep $((DELAY * 1000 + RANDOM % 1000 ))
   echo n > /proc/$OUT/fd/1                 # Trigger defect
done
=============================================================

Note that the failure window is quite small and I could only
reliably reproduce the defect by inserting a small delay
in pipe_rdwr_open(). For example:

 static int
 pipe_rdwr_open(struct inode *inode, struct file *filp)
 {
       msleep(100);
       mutex_lock(&inode->i_mutex);

Although the defect was observed in pipe_rdwr_open(), I think it
makes sense to replicate the change through all the pipe_*_open()
functions.

The core of the change is to verify that inode->i_pipe has not
been released before attempting to manipulate it. If inode->i_pipe
is no longer present, return ENOENT to indicate so.

The comment about potentially using atomic_t for i_pipe->readers
and i_pipe->writers has also been removed because it is no longer
relevant in this context. The inode->i_mutex lock must be used so
that inode->i_pipe can be dealt with correctly.
Signed-off-by: NEarl Chew <earl_chew@agilent.com>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In ks8851_set_rx_mode() the case handling IFF_MULTICAST was also setting
the RXCR1_AE bit by accident. This meant that all unicast frames where
being accepted by the device. Remove RXCR1_AE from this case.

Note, RXCR1_AE was also masking a problem with setting the MAC address
properly, so needs to be applied after fixing the MAC write order.

Fixes a bug reported by Doong, Ping of Micrel. This version of the
patch avoids setting RXCR1_ME for all cases.
Signed-off-by: NBen Dooks <ben@simtec.co.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The MAC address register was being written in the wrong order, so add
a new address macro to convert mac-address byte to register address and
a ks8851_wrreg8() function to write each byte without having to worry
about any difficult byte swapping.

Fixes a bug reported by Doong, Ping of Micrel.
Signed-off-by: NBen Dooks <ben@simtec.co.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Issue a full soft reset at probe time.

This was reported by Doong Ping of Micrel, but no explanation of why this
is necessary or what bug it is fixing. Add it as it does not seem to hurt
the current driver and ensures that the device is in a known state when we
start setting it up.
Signed-off-by: NBen Dooks <ben@simtec.co.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fec_enet_init is called by both fec_probe and fec_resume, so it
shouldn't be marked as __init.
Signed-off-by: NSteven King <sfking@fdwdc.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Mask off FS_EVENT_ON_CHILD in dnotify_handle_event().  Otherwise, when there
is more than one watch on a directory and dnotify_should_send_event()
succeeds, events with FS_EVENT_ON_CHILD set will trigger all watches and cause
spurious events.

This case was overlooked in commit e42e2773.

	#define _GNU_SOURCE

	#include <stdio.h>
	#include <stdlib.h>
	#include <unistd.h>
	#include <signal.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <fcntl.h>
	#include <string.h>

	static void create_event(int s, siginfo_t* si, void* p)
	{
		printf("create\n");
	}

	static void delete_event(int s, siginfo_t* si, void* p)
	{
		printf("delete\n");
	}

	int main (void) {
		struct sigaction action;
		char *tmpdir, *file;
		int fd1, fd2;

		sigemptyset (&action.sa_mask);
		action.sa_flags = SA_SIGINFO;

		action.sa_sigaction = create_event;
		sigaction (SIGRTMIN + 0, &action, NULL);

		action.sa_sigaction = delete_event;
		sigaction (SIGRTMIN + 1, &action, NULL);

	#	define TMPDIR "/tmp/test.XXXXXX"
		tmpdir = malloc(strlen(TMPDIR) + 1);
		strcpy(tmpdir, TMPDIR);
		mkdtemp(tmpdir);

	#	define TMPFILE "/file"
		file = malloc(strlen(tmpdir) + strlen(TMPFILE) + 1);
		sprintf(file, "%s/%s", tmpdir, TMPFILE);

		fd1 = open (tmpdir, O_RDONLY);
		fcntl(fd1, F_SETSIG, SIGRTMIN);
		fcntl(fd1, F_NOTIFY, DN_MULTISHOT | DN_CREATE);

		fd2 = open (tmpdir, O_RDONLY);
		fcntl(fd2, F_SETSIG, SIGRTMIN + 1);
		fcntl(fd2, F_NOTIFY, DN_MULTISHOT | DN_DELETE);

		if (fork()) {
			/* This triggers a create event */
			creat(file, 0600);
			/* This triggers a create and delete event (!) */
			unlink(file);
		} else {
			sleep(1);
			rmdir(tmpdir);
		}

		return 0;
	}
Signed-off-by: NAndreas Gruenbacher <agruen@suse.de>
Signed-off-by: NEric Paris <eparis@redhat.com>

commit 9e337b0f (net: annotate inet_timewait_sock bitfields)
added 4/8 bytes in struct inet_timewait_sock.

Fix this by declaring tw_ipv6_offset in the 'flags' bitfield
The 14 bits hole is named tw_pad to make it cleary apparent.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch tries to print out more information when we hit the
MSG_PEEK bug in tcp_recvmsg.  It's been around since at least
2005 and it's about time that we finally fix it.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When renaming kernel_fpu_using to irq_fpu_usable, the semantics of the
function is changed too, from mesuring whether kernel is using FPU,
that is, the FPU is NOT available, to measuring whether FPU is usable,
that is, the FPU is available.

But the usage of irq_fpu_usable in aesni-intel_glue.c is not changed
accordingly. This patch fixes this.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

ipv4/ipv6 setsockopt(IP_MULTICAST_IF) have dubious __dev_get_by_index() calls.

This function should be called only with RTNL or dev_base_lock held, or reader
could see a corrupt hash chain and eventually enter an endless loop.

Fix is to call dev_get_by_index()/dev_put().

If this happens to be performance critical, we could define a new dev_exist_by_index()
function to avoid touching dev refcount.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When shutdown ppp connection, lockdep waring about non-static key
will happen, it is caused by the lock is not initialized properly
at that time.

Fix with tuning the lock/skb_queue_head init order

[   94.339261] INFO: trying to register non-static key.
[   94.342509] the code is fine but needs lockdep annotation.
[   94.342509] turning off the locking correctness validator.
[   94.342509] Pid: 0, comm: swapper Not tainted 2.6.31-mm1 #2
[   94.342509] Call Trace:
[   94.342509]  [<c0248fbe>] register_lock_class+0x58/0x241
[   94.342509]  [<c024b5df>] ? __lock_acquire+0xb57/0xb73
[   94.342509]  [<c024ab34>] __lock_acquire+0xac/0xb73
[   94.342509]  [<c024b7fa>] ? lock_release_non_nested+0x17b/0x1de
[   94.342509]  [<c024b662>] lock_acquire+0x67/0x84
[   94.342509]  [<c04cd1eb>] ? skb_dequeue+0x15/0x41
[   94.342509]  [<c054a857>] _spin_lock_irqsave+0x2f/0x3f
[   94.342509]  [<c04cd1eb>] ? skb_dequeue+0x15/0x41
[   94.342509]  [<c04cd1eb>] skb_dequeue+0x15/0x41
[   94.342509]  [<c054a648>] ? _read_unlock+0x1d/0x20
[   94.342509]  [<c04cd641>] skb_queue_purge+0x14/0x1b
[   94.342509]  [<fab94fdc>] l2cap_recv_frame+0xea1/0x115a [l2cap]
[   94.342509]  [<c024b5df>] ? __lock_acquire+0xb57/0xb73
[   94.342509]  [<c0249c04>] ? mark_lock+0x1e/0x1c7
[   94.342509]  [<f8364963>] ? hci_rx_task+0xd2/0x1bc [bluetooth]
[   94.342509]  [<fab95346>] l2cap_recv_acldata+0xb1/0x1c6 [l2cap]
[   94.342509]  [<f8364997>] hci_rx_task+0x106/0x1bc [bluetooth]
[   94.342509]  [<fab95295>] ? l2cap_recv_acldata+0x0/0x1c6 [l2cap]
[   94.342509]  [<c02302c4>] tasklet_action+0x69/0xc1
[   94.342509]  [<c022fbef>] __do_softirq+0x94/0x11e
[   94.342509]  [<c022fcaf>] do_softirq+0x36/0x5a
[   94.342509]  [<c022fe14>] irq_exit+0x35/0x68
[   94.342509]  [<c0204ced>] do_IRQ+0x72/0x89
[   94.342509]  [<c02038ee>] common_interrupt+0x2e/0x34
[   94.342509]  [<c024007b>] ? pm_qos_add_requirement+0x63/0x9d
[   94.342509]  [<c038e8a5>] ? acpi_idle_enter_bm+0x209/0x238
[   94.342509]  [<c049d238>] cpuidle_idle_call+0x5c/0x94
[   94.342509]  [<c02023f8>] cpu_idle+0x4e/0x6f
[   94.342509]  [<c0534153>] rest_init+0x53/0x55
[   94.342509]  [<c0781894>] start_kernel+0x2f0/0x2f5
[   94.342509]  [<c0781091>] i386_start_kernel+0x91/0x96
Reported-by: NOliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: NDave Young <hidave.darkstar@gmail.com>
Tested-by: NOliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Due to driver core changes dev_set_drvdata will call kzalloc which should be
in might_sleep context, but hci_conn_add will be called in atomic context

Like dev_set_name move dev_set_drvdata to work queue function.

oops as following:

Oct  2 17:41:59 darkstar kernel: [  438.001341] BUG: sleeping function called from invalid context at mm/slqb.c:1546
Oct  2 17:41:59 darkstar kernel: [  438.001345] in_atomic(): 1, irqs_disabled(): 0, pid: 2133, name: sdptool
Oct  2 17:41:59 darkstar kernel: [  438.001348] 2 locks held by sdptool/2133:
Oct  2 17:41:59 darkstar kernel: [  438.001350]  #0:  (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.+.}, at: [<faa1d2f5>] lock_sock+0xa/0xc [l2cap]
Oct  2 17:41:59 darkstar kernel: [  438.001360]  #1:  (&hdev->lock){+.-.+.}, at: [<faa20e16>] l2cap_sock_connect+0x103/0x26b [l2cap]
Oct  2 17:41:59 darkstar kernel: [  438.001371] Pid: 2133, comm: sdptool Not tainted 2.6.31-mm1 #2
Oct  2 17:41:59 darkstar kernel: [  438.001373] Call Trace:
Oct  2 17:41:59 darkstar kernel: [  438.001381]  [<c022433f>] __might_sleep+0xde/0xe5
Oct  2 17:41:59 darkstar kernel: [  438.001386]  [<c0298843>] __kmalloc+0x4a/0x15a
Oct  2 17:41:59 darkstar kernel: [  438.001392]  [<c03f0065>] ? kzalloc+0xb/0xd
Oct  2 17:41:59 darkstar kernel: [  438.001396]  [<c03f0065>] kzalloc+0xb/0xd
Oct  2 17:41:59 darkstar kernel: [  438.001400]  [<c03f04ff>] device_private_init+0x15/0x3d
Oct  2 17:41:59 darkstar kernel: [  438.001405]  [<c03f24c5>] dev_set_drvdata+0x18/0x26
Oct  2 17:41:59 darkstar kernel: [  438.001414]  [<fa51fff7>] hci_conn_init_sysfs+0x40/0xd9 [bluetooth]
Oct  2 17:41:59 darkstar kernel: [  438.001422]  [<fa51cdc0>] ? hci_conn_add+0x128/0x186 [bluetooth]
Oct  2 17:41:59 darkstar kernel: [  438.001429]  [<fa51ce0f>] hci_conn_add+0x177/0x186 [bluetooth]
Oct  2 17:41:59 darkstar kernel: [  438.001437]  [<fa51cf8a>] hci_connect+0x3c/0xfb [bluetooth]
Oct  2 17:41:59 darkstar kernel: [  438.001442]  [<faa20e87>] l2cap_sock_connect+0x174/0x26b [l2cap]
Oct  2 17:41:59 darkstar kernel: [  438.001448]  [<c04c8df5>] sys_connect+0x60/0x7a
Oct  2 17:41:59 darkstar kernel: [  438.001453]  [<c024b703>] ? lock_release_non_nested+0x84/0x1de
Oct  2 17:41:59 darkstar kernel: [  438.001458]  [<c028804b>] ? might_fault+0x47/0x81
Oct  2 17:41:59 darkstar kernel: [  438.001462]  [<c028804b>] ? might_fault+0x47/0x81
Oct  2 17:41:59 darkstar kernel: [  438.001468]  [<c033361f>] ? __copy_from_user_ll+0x11/0xce
Oct  2 17:41:59 darkstar kernel: [  438.001472]  [<c04c9419>] sys_socketcall+0x82/0x17b
Oct  2 17:41:59 darkstar kernel: [  438.001477]  [<c020329d>] syscall_call+0x7/0xb
Signed-off-by: NDave Young <hidave.darkstar@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix TCP_DEFER_ACCEPT conversion between seconds and
retransmission to match the TCP SYN-ACK retransmission periods
because the time is converted to such retransmissions. The old
algorithm selects one more retransmission in some cases. Allow
up to 255 retransmissions.
Signed-off-by: NJulian Anastasov <ja@ssi.bg>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change SYN-ACK retransmitting code for the TCP_DEFER_ACCEPT
users to not retransmit SYN-ACKs during the deferring period if
ACK from client was received. The goal is to reduce traffic
during the deferring period. When the period is finished
we continue with sending SYN-ACKs (at least one) but this time
any traffic from client will change the request to established
socket allowing application to terminate it properly.
Also, do not drop acked request if sending of SYN-ACK fails.
Signed-off-by: NJulian Anastasov <ja@ssi.bg>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Willy Tarreau and many other folks in recent years
were concerned what happens when the TCP_DEFER_ACCEPT period
expires for clients which sent ACK packet. They prefer clients
that actively resend ACK on our SYN-ACK retransmissions to be
converted from open requests to sockets and queued to the
listener for accepting after the deferring period is finished.
Then application server can decide to wait longer for data
or to properly terminate the connection with FIN if read()
returns EAGAIN which is an indication for accepting after
the deferring period. This change still can have side effects
for applications that expect always to see data on the accepted
socket. Others can be prepared to work in both modes (with or
without TCP_DEFER_ACCEPT period) and their data processing can
ignore the read=EAGAIN notification and to allocate resources for
clients which proved to have no data to send during the deferring
period. OTOH, servers that use TCP_DEFER_ACCEPT=1 as flag (not
as a timeout) to wait for data will notice clients that didn't
send data for 3 seconds but that still resend ACKs.
Thanks to Willy Tarreau for the initial idea and to
Eric Dumazet for the review and testing the change.
Signed-off-by: NJulian Anastasov <ja@ssi.bg>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 6d01a026.

Julian Anastasov, Willy Tarreau and Eric Dumazet have come up
with a more correct way to deal with this.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I found a deadlock bug in UNIX domain socket, which makes able to DoS
attack against the local machine by non-root users.

How to reproduce:
1. Make a listening AF_UNIX/SOCK_STREAM socket with an abstruct
    namespace(*), and shutdown(2) it.
 2. Repeat connect(2)ing to the listening socket from the other sockets
    until the connection backlog is full-filled.
 3. connect(2) takes the CPU forever. If every core is taken, the
    system hangs.

PoC code: (Run as many times as cores on SMP machines.)

int main(void)
{
	int ret;
	int csd;
	int lsd;
	struct sockaddr_un sun;

	/* make an abstruct name address (*) */
	memset(&sun, 0, sizeof(sun));
	sun.sun_family = PF_UNIX;
	sprintf(&sun.sun_path[1], "%d", getpid());

	/* create the listening socket and shutdown */
	lsd = socket(AF_UNIX, SOCK_STREAM, 0);
	bind(lsd, (struct sockaddr *)&sun, sizeof(sun));
	listen(lsd, 1);
	shutdown(lsd, SHUT_RDWR);

	/* connect loop */
	alarm(15); /* forcely exit the loop after 15 sec */
	for (;;) {
		csd = socket(AF_UNIX, SOCK_STREAM, 0);
		ret = connect(csd, (struct sockaddr *)&sun, sizeof(sun));
		if (-1 == ret) {
			perror("connect()");
			break;
		}
		puts("Connection OK");
	}
	return 0;
}

(*) Make sun_path[0] = 0 to use the abstruct namespace.
    If a file-based socket is used, the system doesn't deadlock because
    of context switches in the file system layer.

Why this happens:
 Error checks between unix_socket_connect() and unix_wait_for_peer() are
 inconsistent. The former calls the latter to wait until the backlog is
 processed. Despite the latter returns without doing anything when the
 socket is shutdown, the former doesn't check the shutdown state and
 just retries calling the latter forever.

Patch:
 The patch below adds shutdown check into unix_socket_connect(), so
 connect(2) to the shutdown socket will return -ECONREFUSED.
Signed-off-by: NTomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
Signed-off-by: NMasanori Yoshida <masanori.yoshida.tv@hitachi.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>