Pull ftrace fixes from Steven Rostedt:
 "Namhyung Kim found and fixed a bug that can crash the kernel by simply
  doing: echo 1234 | tee -a /sys/kernel/debug/tracing/set_ftrace_pid

  Luckily, this can only be done by root, but still is a nasty bug."

* tag 'trace-fixes-v3.9-rc-v3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Move ftrace_filter_lseek out of CONFIG_DYNAMIC_FTRACE section
  tracing: Fix possible NULL pointer dereferences

Nothing is using it yet, but this will allow us to delay the open-time
checks to use time, without breaking the normal UNIX permission
semantics where permissions are determined by the opener (and the file
descriptor can then be passed to a different process, or the process can
drop capabilities).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This patch attempts to fix:

	https://bugzilla.kernel.org/show_bug.cgi?id=56461

The symptom is a crash and messages like this:

	chrome: Corrupted page table at address 34a03000
	*pdpt = 0000000000000000 *pde = 0000000000000000
	Bad pagetable: 000f [#1] PREEMPT SMP

Ingo guesses this got introduced by commit 611ae8e3f520 ("x86/tlb:
enable tlb flush range support for x86") since that code started to free
unused pagetables.

On x86-32 PAE kernels, that new code has the potential to free an entire
PMD page and will clear one of the four page-directory-pointer-table
(aka pgd_t entries).

The hardware aggressively "caches" these top-level entries and invlpg
does not actually affect the CPU's copy.  If we clear one we *HAVE* to
do a full TLB flush, otherwise we might continue using a freed pmd page.
(note, we do this properly on the population side in pud_populate()).

This patch tracks whenever we clear one of these entries in the 'struct
mmu_gather', and ensures that we follow up with a full tlb flush.

BTW, I disassembled and checked that:

	if (tlb->fullmm == 0)
and
	if (!tlb->fullmm && !tlb->need_flush_all)

generate essentially the same code, so there should be zero impact there
to the !PAE case.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Artem S Tashkinov <t.artem@mailcity.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

As ftrace_filter_lseek is now used with ftrace_pid_fops, it needs to
be moved out of the #ifdef CONFIG_DYNAMIC_FTRACE section as the
ftrace_pid_fops is defined when DYNAMIC_FTRACE is not.

Cc: stable@vger.kernel.org
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Currently set_ftrace_pid and set_graph_function files use seq_lseek
for their fops.  However seq_open() is called only for FMODE_READ in
the fops->open() so that if an user tries to seek one of those file
when she open it for writing, it sees NULL seq_file and then panic.

It can be easily reproduced with following command:

  $ cd /sys/kernel/debug/tracing
  $ echo 1234 | sudo tee -a set_ftrace_pid

In this example, GNU coreutils' tee opens the file with fopen(, "a")
and then the fopen() internally calls lseek().

Link: http://lkml.kernel.org/r/1365663302-2170-1-git-send-email-namhyung@kernel.org

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: stable@vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Pull networking fixes from David Miller:

 1) cfg80211_conn_scan() must be called with the sched_scan_mutex, fix
    from Artem Savkov.

 2) Fix regression in TCP ICMPv6 processing, we do not want to treat
    redirects as socket errors, from Christoph Paasch.

 3) Fix several recvmsg() msg_name kernel memory leaks into userspace,
    in ATM, AX25, Bluetooth, CAIF, IRDA, s390 IUCV, L2TP, LLC, Netrom,
    NFC, Rose, TIPC, and VSOCK.  From Mathias Krause and Wei Yongjun.

 4) Fix AF_IUCV handling of segmented SKBs in recvmsg(), from Ursula
    Braun and Eric Dumazet.

 5) CAN gw.c code does kfree() on SLAB cache memory, use
    kmem_cache_free() instead.  Fix from Wei Yongjun.

 6) Fix LSM regression on TCP SYN/ACKs, some LSMs such as SELINUX want
    an skb->sk socket context available for these packets, but nothing
    else requires it.  From Eric Dumazet and Paul Moore.

 7) Fix ipv4 address lifetime processing so that we don't perform
    sleepable acts inside of rcu_read_lock() sections, do them in an
    rtnl_lock() section instead.  From Jiri Pirko.

 8) mvneta driver accidently sets HW features after device registry, it
    should do so beforehand.  Fix from Willy Tarreau.

 9) Fix bonding unload races more correctly, from Nikolay Aleksandrov
    and Veaceslav Falico.

10) rtnl_dump_ifinfo() and rtnl_calcit() invoke nlmsg_parse() with wrong
    header size argument.  Fix from Michael Riesch.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (44 commits)
  lsm: add the missing documentation for the security_skb_owned_by() hook
  bnx2x: Prevent null pointer dereference in AFEX mode
  e100: Add dma mapping error check
  selinux: add a skb_owned_by() hook
  can: gw: use kmem_cache_free() instead of kfree()
  netrom: fix invalid use of sizeof in nr_recvmsg()
  qeth: fix qeth_wait_for_threads() deadlock for OSN devices
  af_iucv: fix recvmsg by replacing skb_pull() function
  rtnetlink: Call nlmsg_parse() with correct header length
  bonding: fix bonding_masters race condition in bond unloading
  Revert "bonding: remove sysfs before removing devices"
  net: mvneta: enable features before registering the driver
  hyperv: Fix RNDIS send_completion code path
  hyperv: Fix a kernel warning from netvsc_linkstatus_callback()
  net: ipv4: fix schedule while atomic bug in check_lifetime()
  net: ipv4: reset check_lifetime_work after changing lifetime
  bnx2x: Fix KR2 rapid link flap
  sctp: remove 'sridhar' from maintainers list
  VSOCK: Fix missing msg_namelen update in vsock_stream_recvmsg()
  VSOCK: vmci - fix possible info leak in vmci_transport_dgram_dequeue()
  ...

Unfortunately we didn't catch the missing comments earlier when the
patch was merged.

Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull vfs fixes from Al Viro:
 "A nasty bug in fs/namespace.c caught by Andrey + a couple of less
  serious unpleasantness - ecryptfs misc device playing hopeless games
  with try_module_get() and palinfo procfs support being...  not quite
  correctly done, to be polite."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  mnt: release locks on error path in do_loopback
  palinfo fixes
  procfs: add proc_remove_subtree()
  ecryptfs: close rmmod race

just what it sounds like; do that only to procfs subtrees you've
created - doing that to something shared with another driver is
not only antisocial, but might cause interesting races with
proc_create() and its ilk.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

In UP and non-preempt respectively, the spinlocks and preemption
disable/enable points are stubbed out entirely, because there is no
regular code that can ever hit the kind of concurrency they are meant to
protect against.

However, while there is no regular code that can cause scheduling, we
_do_ end up having some exceptional (literally!) code that can do so,
and that we need to make sure does not ever get moved into the critical
region by the compiler.

In particular, get_user() and put_user() is generally implemented as
inline asm statements (even if the inline asm may then make a call
instruction to call out-of-line), and can obviously cause a page fault
and IO as a result.  If that inline asm has been scheduled into the
middle of a preemption-safe (or spinlock-protected) code region, we
obviously lose.

Now, admittedly this is *very* unlikely to actually ever happen, and
we've not seen examples of actual bugs related to this.  But partly
exactly because it's so hard to trigger and the resulting bug is so
subtle, we should be extra careful to get this right.

So make sure that even when preemption is disabled, and we don't have to
generate any actual *code* to explicitly tell the system that we are in
a preemption-disabled region, we need to at least tell the compiler not
to move things around the critical region.

This patch grew out of the same discussion that caused commits
79e5f05edcbf ("ARC: Add implicit compiler barrier to raw_local_irq*
functions") and 3e2e0d2c222b ("tile: comment assumption about
__insn_mtspr for <asm/irqflags.h>") to come about.

Note for stable: use discretion when/if applying this.  As mentioned,
this bug may never have actually bitten anybody, and gcc may never have
done the required code motion for it to possibly ever trigger in
practice.

Cc: stable@vger.kernel.org
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>