ksm.c's write_protect_page implements a lockless means of verifying a page
does not have any users of the page which are not accounted for via other
kernel tracking means.  It does this by removing the writable pte with TLB
flushes, checking the page_count against the total known users, and then
using set_pte_at_notify to make it a read-only entry.

An unneeded mmu_notifier callout is made in the case where the known users
does not match the page_count.  In that event, we are inserting the
identical pte and there is no need for the set_pte_at_notify, but rather
the simpler set_pte_at suffices.
Signed-off-by: NRobin Holt <holt@sgi.com>
Acked-by: NIzik Eidus <ieidus@redhat.com>
Acked-by: NAndrea Arcangeli <aarcange@redhat.com>
Acked-by: NHugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Chris Wright <chrisw@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix a fatal error in scripts/kernel-doc when a function signature uses
__init_or_module (just ignore that string):

Error(drivers/base/platform.c:568): cannot understand prototype: 'struct platform_device * __init_or_module platform_create_bundle(struct platform_driver *driver, int (*probe)(struct platform_device *), struct resource *res, unsigned int n_res, const void *data, size_t size) '
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch renames PCI/PCI-DMA-mapping.txt to DMA-API-HOWTO.txt.

The commit 51e7364e "Documentation: rename
PCI-DMA-mapping.txt to DMA-API-HOWTO.txt" was supposed to do this but it
didn't.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/linux/kfifo.h first defines and then undefines __kfifo_initializer
which is used by INIT_KFIFO (which is also a macro, so building a module
which uses INIT_KFIFO will fail).
Signed-off-by: NDavid Härdeman <david@hardeman.nu>
Acked-by: NStefani Seibold <stefani@seibold.net>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix an incorrect comment in the do_mmap_shared_file().  If a mapping is
requested MAP_SHARED, then a private copy cannot be made and still provide
correct semantics.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Reported-by: NDave Hudson <uclinux@blueteddy.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Keeps MAINTAINERS a bit more consistent.
done via sed -r -i -e 's/^([A-Z]):[ \t]+/\1:\t/g' MAINTAINERS
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

According to the header in max730x it is licensed GPLv2.

Add a MODULE_LICENSE to avoid getting the kernel tainted.

[w.sang@pengutronix.de: add MODULE_AUTHOR and MODULE_DESCRIPTION also]
Signed-off-by: NRichard Röjfors <richard.rojfors@pelagicore.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update memory.txt to be more consistent: s/swapiness/swappiness/
Signed-off-by: NGreg Thelen <gthelen@google.com>
Acked-by: NBalbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 22dd5b0c (fix perlcritic warnings)
broke the ability to handle STDIN because the three argument version of
open() cannot handle standard IO-streams (which is mentioned in
PerlBestPractices, too).
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We see only one section mismatch now after thousands of randconfigs, and a
bug has been filed about that one.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

cpu_relax() is documented in volatile-considered-harmful.txt to be a
memory barrier.  However, everyone with the exception of Blackfin and
possibly ia64 defines cpu_relax() to be a compiler barrier.

Make the documentation reflect the general concensus.

Linus sayeth:

: I don't think it was ever the intention that it would be seen as anything
: but a compiler barrier, although it is obviously implied that it might
: well perform some per-architecture actions that have "memory barrier-like"
: semantics.
:
: After all, the whole and only point of the "cpu_relax()" thing is to tell
: the CPU that we're busy-looping on some event.
:
: And that "event" might be (and often is) about reading the same memory
: location over and over until it changes to what we want it to be.  So it's
: quite possible that on various architectures the "cpu_relax()" could be
: about making sure that such a tight loop on loads doesn't starve cache
: transactions, for example - and as such look a bit like a memory barrier
: from a CPU standpoint.
:
: But it's not meant to have any kind of architectural memory ordering
: semantics as far as the kernel is concerned - those must come from other
: sources.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Cc: <linux-arch@vger.kernel.org>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/binfmt_aout.c: In function `aout_core_dump':
fs/binfmt_aout.c:125: warning: passing argument 2 of `dump_write' makes pointer from integer without a cast
include/linux/coredump.h:12: note: expected `const void *' but argument is of type `long unsigned int'
fs/binfmt_aout.c:132: warning: passing argument 2 of `dump_write' makes pointer from integer without a cast
include/linux/coredump.h:12: note: expected `const void *' but argument is of type `long unsigned int'

due to dump_write() expecting a user void *.  Fold casts into the
START_DATA/START_STACK macros and shut up the warnings.
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Cc: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

scripts/kernel-doc erroneously says:

Warning(include/linux/skbuff.h:410): Excess struct/union/enum/typedef member 'cb' description in 'sk_buff'

on this line in struct sk_buff:
	char			cb[48] __aligned(8);

due to treating the last field as the struct member name, so teach
kernel-doc to ignore __aligned(x) in structs.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This was introduced by v2.6.34-rc1~38:

	4c014e87 (rtc/mc13783: protect rtc {,un}registration by mc13783 lock)
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reported-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There was a potential null deref introduced in c62b1a3b ("memcg: use
generic percpu instead of private implementation").
Signed-off-by: NDan Carpenter <error27@gmail.com>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

commit e6a1105b ("cgroups: subsystem module loading interface") and commit
c50cc752 ("sched, cgroups: Fix module export") result in duplicate
including of module.h
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NPaul Menage <menage@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In commit 02491447 ("memcg: move charges of anonymous swap"), I tried to
disable move charge feature in no mmu case by enclosing all the related
functions with "#ifdef CONFIG_MMU", but the commit places these ifdefs in
wrong place.  (it seems that it's mangled while handling some fixes...)

This patch fixes it up.
Signed-off-by: NDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 45575f5a ("ppc64 sys_ipc breakage in 2.6.34-rc2") fixed the
definition of the sys_ipc() helper, but didn't fix the prototype in
<linux/syscalls.h>
Reported-and-tested-by: NAndreas Schwab <schwab@linux-m68k.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio: console: Check if port is valid in resize_console
  virtio: console: Generate a kobject CHANGE event on adding 'name' attribute

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (38 commits)
  ip_gre: include route header_len in max_headroom calculation
  if_tunnel.h: add missing ams/byteorder.h include
  ipv4: Don't drop redirected route cache entry unless PTMU actually expired
  net: suppress lockdep-RCU false positive in FIB trie.
  Bluetooth: Fix kernel crash on L2CAP stress tests
  Bluetooth: Convert debug files to actually use debugfs instead of sysfs
  Bluetooth: Fix potential bad memory access with sysfs files
  netfilter: ctnetlink: fix reliable event delivery if message building fails
  netlink: fix NETLINK_RECV_NO_ENOBUFS in netlink_set_err()
  NET_DMA: free skbs periodically
  netlink: fix unaligned access in nla_get_be64()
  tcp: Fix tcp_mark_head_lost() with packets == 0
  net: ipmr/ip6mr: fix potential out-of-bounds vif_table access
  KS8695: update ksp->next_rx_desc_read at the end of rx loop
  igb: Add support for 82576 ET2 Quad Port Server Adapter
  ixgbevf: Message formatting cleanups
  ixgbevf: Shorten up delay timer for watchdog task
  ixgbevf: Fix VF Stats accounting after reset
  ixgbe: Set IXGBE_RSC_CB(skb)->DMA field to zero after unmapping the address
  ixgbe: fix for real_num_tx_queues update issue
  ...

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
  edac, mce: Filter out invalid values

alloc_skb() can return NULL.
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It seems clear from the surrounding code that xpermits is allowed to be
NULL here.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I chased down a fail on ppc64 on 2.6.34-rc2 where an application that
uses shared memory was getting a SEGV.

Commit baed7fc9 ("Add generic sys_ipc
wrapper") changed the second argument from an unsigned long to an int.
When we call shmget the system call wrappers for sys_ipc will sign
extend second (ie the size) which truncates it.  It took a while to
track down because the call succeeds and strace shows the untruncated
size :)

The patch below changes second from an int to an unsigned long which
fixes shmget on ppc64 (and I assume s390, sparc64 and mips64).
Signed-off-by: NAnton Blanchard <anton@samba.org>
--

I assume the function prototypes for the other IPC methods would cause us
to sign or zero extend second where appropriate (avoiding any security
issues). Come to think of it, the syscall wrappers for each method should do
that for us as well.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 3f6da390
(perf: Rework and fix the arch CPU-hotplug hooks) broke suspend to
RAM on my HP nx6325 (and most likely on other AMD-based boxes too)
by allowing amd_pmu_cpu_offline() to be executed for CPUs that are
going offline as part of the suspend process.  The problem is that
cpuhw->amd_nb may be NULL already, so the function should make sure
it's not NULL before accessing the object pointed to by it.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Print the CPU associated with the error only when the field is valid.

Cc: <stable@kernel.org> # .32.x .33.x
Signed-off-by: NBorislav Petkov <borislav.petkov@amd.com>

The console port could have been hot-unplugged. Check if it is valid
before working on it.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

When the host lets us know what 'name' a port is assigned, we create the
sysfs 'name' attribute. Generate a 'change' event after this so that
udev wakes up and acts on the rules for virtio-ports (currently there's
only one rule that creates a symlink from the 'name' to the actual char
device).
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

Taking route's header_len into account, and updating gre device
needed_headroom will give better hints on upper bound of required
headroom. This is useful if the gre traffic is xfrm'ed.
Signed-off-by: NTimo Teras <timo.teras@iki.fi>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When compiling userspace application which includes
if_tunnel.h and uses GRE_* defines you will get undefined
reference to __cpu_to_be16.

Fix this by adding missing #include <asm/byteorder.h>

Cc: stable@kernel.org
Signed-off-by: NPaulius Zaleckas <paulius.zaleckas@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

TCP sessions over IPv4 can get stuck if routers between endpoints
do not fragment packets but implement PMTU instead, and we are using
those routers because of an ICMP redirect.

Setup is as follows

       MTU1    MTU2   MTU1
    A--------B------C------D

with MTU1 > MTU2. A and D are endpoints, B and C are routers. B and C
implement PMTU and drop packets larger than MTU2 (for example because
DF is set on all packets). TCP sessions are initiated between A and D.
There is packet loss between A and D, causing frequent TCP
retransmits.

After the number of retransmits on a TCP session reaches tcp_retries1,
tcp calls dst_negative_advice() prior to each retransmit. This results
in route cache entries for the peer to be deleted in
ipv4_negative_advice() if the Path MTU is set.

If the outstanding data on an affected TCP session is larger than
MTU2, packets sent from the endpoints will be dropped by B or C, and
ICMP NEEDFRAG will be returned. A and D receive NEEDFRAG messages and
update PMTU.

Before the next retransmit, tcp will again call dst_negative_advice(),
causing the route cache entry (with correct PMTU) to be deleted. The
retransmitted packet will be larger than MTU2, causing it to be
dropped again.

This sequence repeats until the TCP session aborts or is terminated.

Problem is fixed by removing redirected route cache entries in
ipv4_negative_advice() only if the PMTU is expired.
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow fib_find_node() to be called either under rcu_read_lock()
protection or with RTNL held.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Added very simple check that req buffer has enough space to
fit configuration parameters. Shall be enough to reject packets
with configuration size more than req buffer.

Crash trace below

[ 6069.659393] Unable to handle kernel paging request at virtual address 02000205
[ 6069.673034] Internal error: Oops: 805 [#1] PREEMPT
...
[ 6069.727172] PC is at l2cap_add_conf_opt+0x70/0xf0 [l2cap]
[ 6069.732604] LR is at l2cap_recv_frame+0x1350/0x2e78 [l2cap]
...
[ 6070.030303] Backtrace:
[ 6070.032806] [<bf1c2880>] (l2cap_add_conf_opt+0x0/0xf0 [l2cap]) from
[<bf1c6624>] (l2cap_recv_frame+0x1350/0x2e78 [l2cap])
[ 6070.043823]  r8:dc5d3100 r7:df2a91d6 r6:00000001 r5:df2a8000 r4:00000200
[ 6070.050659] [<bf1c52d4>] (l2cap_recv_frame+0x0/0x2e78 [l2cap]) from
[<bf1c8408>] (l2cap_recv_acldata+0x2bc/0x350 [l2cap])
[ 6070.061798] [<bf1c814c>] (l2cap_recv_acldata+0x0/0x350 [l2cap]) from
[<bf0037a4>] (hci_rx_task+0x244/0x478 [bluetooth])
[ 6070.072631]  r6:dc647700 r5:00000001 r4:df2ab740
[ 6070.077362] [<bf003560>] (hci_rx_task+0x0/0x478 [bluetooth]) from
[<c006b9fc>] (tasklet_action+0x78/0xd8)
[ 6070.087005] [<c006b984>] (tasklet_action+0x0/0xd8) from [<c006c160>]
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@nokia.com>
Acked-by: NGustavo F. Padovan <gustavo@padovan.org>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Some of the debug files ended up wrongly in sysfs, because at that point
of time, debugfs didn't exist. Convert these files to use debugfs and
also seq_file. This patch converts all of these files at once and then
removes the exported symbol for the Bluetooth sysfs class.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When creating a high number of Bluetooth sockets (L2CAP, SCO
and RFCOMM) it is possible to scribble repeatedly on arbitrary
pages of memory. Ensure that the content of these sysfs files is
always less than one page. Even if this means truncating. The
files in question are scheduled to be moved over to debugfs in
the future anyway.

Based on initial patches from Neil Brown and Linus Torvalds
Reported-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch fixes a bug that allows to lose events when reliable
event delivery mode is used, ie. if NETLINK_BROADCAST_SEND_ERROR
and NETLINK_RECV_NO_ENOBUFS socket options are set.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, ENOBUFS errors are reported to the socket via
netlink_set_err() even if NETLINK_RECV_NO_ENOBUFS is set. However,
that should not happen. This fixes this problem and it changes the
prototype of netlink_set_err() to return the number of sockets that
have set the NETLINK_RECV_NO_ENOBUFS socket option. This return
value is used in the next patch in these bugfix series.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Under NET_DMA, data transfer can grind to a halt when userland issues a
large read on a socket with a high RCVLOWAT (i.e., 512 KB for both).
This appears to be because the NET_DMA design queues up lots of memcpy
operations, but doesn't issue or wait for them (and thus free the
associated skbs) until it is time for tcp_recvmesg() to return.
The socket hangs when its TCP window goes to zero before enough data is
available to satisfy the read.

Periodically issue asynchronous memcpy operations, and free skbs for ones
that have completed, to prevent sockets from going into zero-window mode.
Signed-off-by: NSteven J. Magnani <steve@digidescorp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>