tmpfs: fix use-after-free of mempolicy object

The tmpfs remount logic preserves filesystem mempolicy if the mpol=M
option is not specified in the remount request.  A new policy can be
specified if mpol=M is given.

Before this patch remounting an mpol bound tmpfs without specifying
mpol= mount option in the remount request would set the filesystem's
mempolicy object to a freed mempolicy object.

To reproduce the problem boot a DEBUG_PAGEALLOC kernel and run:
    # mkdir /tmp/x

    # mount -t tmpfs -o size=100M,mpol=interleave nodev /tmp/x

    # grep /tmp/x /proc/mounts
    nodev /tmp/x tmpfs rw,relatime,size=102400k,mpol=interleave:0-3 0 0

    # mount -o remount,size=200M nodev /tmp/x

    # grep /tmp/x /proc/mounts
    nodev /tmp/x tmpfs rw,relatime,size=204800k,mpol=??? 0 0
        # note ? garbage in mpol=... output above

    # dd if=/dev/zero of=/tmp/x/f count=1
        # panic here

Panic:
    BUG: unable to handle kernel NULL pointer dereference at           (null)
    IP: [<          (null)>]           (null)
    [...]
    Oops: 0010 [#1] SMP DEBUG_PAGEALLOC
    Call Trace:
     [<ffffffff81186ead>] ? mpol_set_nodemask+0x8d/0x100
     [<ffffffff811895ef>] ? mpol_shared_policy_init+0x8f/0x160
     [<ffffffff81189605>] mpol_shared_policy_init+0xa5/0x160
     [<ffffffff811580e1>] ? shmem_get_inode+0x1e1/0x270
     [<ffffffff811580e1>] ? shmem_get_inode+0x1e1/0x270
     [<ffffffff810db15d>] ? trace_hardirqs_on+0xd/0x10
     [<ffffffff81158109>] shmem_get_inode+0x209/0x270
     [<ffffffff811581ae>] shmem_mknod+0x3e/0xf0
     [<ffffffff811582b8>] shmem_create+0x18/0x20
     [<ffffffff811af5d5>] vfs_create+0xb5/0x130
     [<ffffffff811afff1>] do_last+0x9a1/0xea0
     [<ffffffff811ac77a>] ? link_path_walk+0x7a/0x930
     [<ffffffff811b05a3>] path_openat+0xb3/0x4d0
     [<ffffffff811be831>] ? __alloc_fd+0x31/0x160
     [<ffffffff811b0de2>] do_filp_open+0x42/0xa0
     [<ffffffff811be8e0>] ? __alloc_fd+0xe0/0x160
     [<ffffffff811a066e>] do_sys_open+0xfe/0x1e0
     [<ffffffff811f0aeb>] compat_sys_open+0x1b/0x20
     [<ffffffff815d6055>] cstar_dispatch+0x7/0x1f
Non-debug kernels will not crash immediately because referencing the
dangling mpol will not cause a fault.  Instead the filesystem will
reference a freed mempolicy object, which will cause unpredictable
behavior.

The problem boils down to a dropped mpol reference below if
shmem_parse_options() does not allocate a new mpol:
    config = *sbinfo
    shmem_parse_options(data, &config, true)
    mpol_put(sbinfo->mpol)
    sbinfo->mpol = config.mpol  /* BUG: saves unreferenced mpol */
This patch avoids the crash by not releasing the mempolicy if
shmem_parse_options() doesn't create a new mpol.

How far back does this issue go?  I see it in both 2.6.36 and 3.3.  I
did not look back further.

Signed-off-by: Greg Thelen <gthelen@google.com>
i2c: tegra: Fix i2c unknown interrupt issue

writes to modules on APB bus may complete out-of-order. need
to guarantee that the write is completed by reading it back.

read I2C_INT_STATUS back right after writing the current int status
in the isr to make sure the clear operation of I2C_INT_STATUS is
done before the interrupt is re-enabled.
the same also done for DVC_STATUS.

bug 980763

Change-Id: I34f18804d530ccadf561fe1736552b6a4dd6e4ce
Signed-off-by: Ken Chang <kenc@nvidia.com>
Reviewed-on: http://git-master/r/101925
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
blkdev.h: default nr_requests to 256
ARM: 7626/1: arm/crypto: Make asm SHA-1 and AES code Thumb-2 compatible

This patch fixes aes-armv4.S and sha1-armv4-large.S to work
natively in Thumb.  This allows ARM/Thumb interworking workarounds
to be removed.

I also take the opportunity to convert some explicit assembler
directives for exported functions to the standard
ENTRY()/ENDPROC().

For the code itself:

  * In sha1_block_data_order, use of TEQ with sp is deprecated in
    ARMv7 and not supported in Thumb.  For the branches back to
    .L_00_15 and .L_40_59, the TEQ is converted to a CMP, under the
    assumption that clobbering the C flag here will not cause
    incorrect behaviour.

    For the first branch back to .L_20_39_or_60_79 the C flag is
    important, so sp is moved temporarily into another register so
    that TEQ can be used for the comparison.

  * In the AES code, most forms of register-indexed addressing with
    shifts and rotates are not permitted for loads and stores in
    Thumb, so the address calculation is done using a separate
    instruction for the Thumb case.

The resulting code is unlikely to be optimally scheduled, but it
should not have a large impact given the overall size of the code.
I haven't run any benchmarks.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Tested-by: David McCullough <ucdevel@gmail.com> (ARM only)
Acked-by: David McCullough <ucdevel@gmail.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7723/1: crypto: sha1-armv4-large.S: fix SP handling

Make the SHA1 asm code ABI conformant by making sure all stack
accesses occur above the stack pointer.

Origin:
http://git.openssl.org/gitweb/?p=openssl.git;a=commit;h=1a9d60d2

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arm: unwind: Remove logspam while in debug mode
Reduce logging

Change-Id: I6a74dd40cedf05ae10afafbdb0e5052acbcf2deb
mmc: core: Fix possbile memory leak

Fix possible memory leak detected by kmemleak:

unreferenced object 0xc0f80f00 (size 64):
  comm "swapper/0", pid 1, jiffies 4294937508 (age 82.980s)
  hex dump (first 32 bytes):
    6d 6d 63 30 5f 64 65 74 65 63 74 00 72 79 2e 68  mmc0_detect.ry.h
    00 07 00 00 68 77 63 61 70 2e 68 00 02 00 00 70  ....hwcap.h....p
  backtrace:
    [<c010a1fc>] __kmalloc+0x164/0x220
    [<c01e1630>] kvasprintf+0x38/0x58
    [<c01e1668>] kasprintf+0x18/0x24
    [<c02fcf60>] mmc_alloc_host+0x114/0x1b4
    [<c0311c84>] msmsdcc_probe+0xc14/0x1fd8
    [<c022b40c>] platform_drv_probe+0x14/0x18
    [<c022a144>] driver_probe_device+0x144/0x334
    [<c022a394>] __driver_attach+0x60/0x84
    [<c022884c>] bus_for_each_dev+0x4c/0x78
    [<c0229720>] bus_add_driver+0xd0/0x250
    [<c022a884>] driver_register+0x9c/0x128
    [<c00086bc>] do_one_initcall+0x90/0x160
    [<c06d1904>] kernel_init+0xe8/0x1a4
    [<c000ee4c>] kernel_thread_exit+0x0/0x8
    [<ffffffff>] 0xffffffff

Change-Id: I3b29d71463af849a072cabbe56637adf6db6d0da
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
slub: fix a possible memory leak

Memory allocated by kstrdup should be freed,
when kmalloc(kmem_size, GFP_KERNEL) is failed.

Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
mmc: decrease wakelock timeout
ARM: 7401/1: mm: Fix section mismatches

WARNING: vmlinux.o(.text+0x111b8): Section mismatch in reference
from the function arm_memory_present() to the function
.init.text:memory_present()
The function arm_memory_present() references
the function __init memory_present().
This is often because arm_memory_present lacks a __init
annotation or the annotation of memory_present is wrong.

WARNING: arch/arm/mm/built-in.o(.text+0x1edc): Section mismatch
in reference from the function alloc_init_pud() to the function
.init.text:alloc_init_section()
The function alloc_init_pud() references
the function __init alloc_init_section().
This is often because alloc_init_pud lacks a __init
annotation or the annotation of alloc_init_section is wrong.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
suspend: shorten time to enter sleep state
mm: improve data writeback operations