mm: Ensure pte and pmd stores ordering.

Bug 974153
Signed-off-by: Krishna Reddy <vdumpa@nvidia.com>

Reviewed-on: http://git-master/r/105215
(cherry picked from commit 25c3334f0e1ea6bde84c0514bad0eb1859566dba)

Change-Id: I3a77ce812fab77f785c488a3aac9d0bc66e8236d
Reviewed-on: http://git-master/r/108446
GVS: Gerrit_Virtual_Submit
Reviewed-by: Sang-Hun Lee <sanlee@nvidia.com>
Tested-by: Sang-Hun Lee <sanlee@nvidia.com>
Reviewed-by: Krishna Reddy <vdumpa@nvidia.com>
ARM: tegra: clock: Update secondary pll dividers resume

During resume from LP0 on Tegra2 always enable pll secondary dividers
before clocks restoration (to make sure clock sources are enabled).
Restore actual secondary dividers settings after clocks are restored.

Bug 965928
Bug 953030

Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>

Reviewed on http://git-master/r/#change,104661
(cherry picked from commit 6350d1fd475373779cf5110403717b2c84e723ba)

Change-Id: I048e3f925daf02074312472afa667609a8338c15
Reviewed-on: http://git-master/r/104698
Reviewed-by: Manish Tuteja <mtuteja@nvidia.com>
Tested-by: Manish Tuteja <mtuteja@nvidia.com>
ARM: tegra: define/enable ARCH_HAS_SUSPEND_PAGETABLE

For Tegra, the CPU suspend code path installs its own 1:1 pagetable
setup once at init time. This pagetable is used by all CPUs doing
suspend/resume.

We want to use the common ARM code for CPU suspend/resume, but don't
want the MMU reenable code to patch the current pagetable as it's
shared (and could cause problems if the pagetable loads/stores were
were interleaved).

The installed pagetable already covers the cpu_resume_turn_mmu_on
VA, so we're able to just use the existing pagetable. This sets up
the CONFIG option to skip this part of the MMU reenable.

Bug 929856

Change-Id: Ibbac258122df6def7f7a2d511778a6f11d474938
Signed-off-by: Chris Johnson <cwj@nvidia.com>
Reviewed-on: http://git-master/r/92350
Reviewed-by: Sang-Hun Lee <sanlee@nvidia.com>
Tested-by: Sang-Hun Lee <sanlee@nvidia.com>
Reviewed-by: Thomas Cherry <tcherry@nvidia.com>
Reviewed-by: Krishna Reddy <vdumpa@nvidia.com>
Reviewed-by: Ahung Cheng <ahcheng@nvidia.com>
Tested-by: Ahung Cheng <ahcheng@nvidia.com>
Reviewed-on: http://git-master/r/103205
Reviewed-by: Simone Willett <swillett@nvidia.com>
Tested-by: Simone Willett <swillett@nvidia.com>
arm: tegra: Enable arm errata 764369

Enable arm errata 764369 for TEGRA_2x and 3x.
Bug 981223
Bug 885467

Change-Id: Ie013dc1ed4f1417a72dda72ea2d079a6534c3933
Signed-off-by: Krishna Reddy <vdumpa@nvidia.com>
Reviewed-on: http://git-master/r/104181
Reviewed-by: Simone Willett <swillett@nvidia.com>
Tested-by: Simone Willett <swillett@nvidia.com>
Revert "device_cgroup: fix RCU usage"

This reverts commit c5ee58688baa98bc3a4f6095a1acf6fd7fd9e967,
which was commit 201e72acb2d3821e2de9ce6091e98859c316b29a upstream.

Herton Ronaldo Krzesinski pointed out that the race condition this
dealt with does not exist in 3.2.y.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Revert "sched, autogroup: Stop going ahead if autogroup is disabled"

commit fd8ef11730f1d03d5d6555aa53126e9e34f52f12 upstream.

This reverts commit 800d4d30c8f20bd728e5741a3b77c4859a613f7c.

Between commits 8323f26ce342 ("sched: Fix race in task_group()") and
800d4d30c8f2 ("sched, autogroup: Stop going ahead if autogroup is
disabled"), autogroup is a wreck.

With both applied, all you have to do to crash a box is disable
autogroup during boot up, then reboot..  boom, NULL pointer dereference
due to commit 800d4d30c8f2 not allowing autogroup to move things, and
commit 8323f26ce342 making that the only way to switch runqueues:

  BUG: unable to handle kernel NULL pointer dereference at           (null)
  IP: [<ffffffff81063ac0>] effective_load.isra.43+0x50/0x90
  Pid: 7047, comm: systemd-user-se Not tainted 3.6.8-smp #7 MEDIONPC MS-7502/MS-7502
  RIP: effective_load.isra.43+0x50/0x90
  Process systemd-user-se (pid: 7047, threadinfo ffff880221dde000, task ffff88022618b3a0)
  Call Trace:
    select_task_rq_fair+0x255/0x780
    try_to_wake_up+0x156/0x2c0
    wake_up_state+0xb/0x10
    signal_wake_up+0x28/0x40
    complete_signal+0x1d6/0x250
    __send_signal+0x170/0x310
    send_signal+0x40/0x80
    do_send_sig_info+0x47/0x90
    group_send_sig_info+0x4a/0x70
    kill_pid_info+0x3a/0x60
    sys_kill+0x97/0x1a0
    ? vfs_read+0x120/0x160
    ? sys_read+0x45/0x90
    system_call_fastpath+0x16/0x1b
  Code: 49 0f af 41 50 31 d2 49 f7 f0 48 83 f8 01 48 0f 46 c6 48 2b 07 48 8b bf 40 01 00 00 48 85 ff 74 3a 45 31 c0 48 8b 8f 50 01 00 00 <48> 8b 11 4c 8b 89 80 00 00 00 49 89 d2 48 01 d0 45 8b 59 58 4c
  RIP  [<ffffffff81063ac0>] effective_load.isra.43+0x50/0x90
   RSP <ffff880221ddfbd8>
  CR2: 0000000000000000

Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Yong Zhang <yong.zhang0@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust filenames]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
tmpfs: fix shared mempolicy leak

commit 18a2f371f5edf41810f6469cb9be39931ef9deb9 upstream.

This fixes a regression in 3.7-rc, which has since gone into stable.

Commit 00442ad04a5e ("mempolicy: fix a memory corruption by refcount
imbalance in alloc_pages_vma()") changed get_vma_policy() to raise the
refcount on a shmem shared mempolicy; whereas shmem_alloc_page() went
on expecting alloc_page_vma() to drop the refcount it had acquired.
This deserves a rework: but for now fix the leak in shmem_alloc_page().

Hugh: shmem_swapin() did not need a fix, but surely it's clearer to use
the same refcounting there as in shmem_alloc_page(), delete its onstack
mempolicy, and the strange mpol_cond_copy() and __mpol_cond_copy() -
those were invented to let swapin_readahead() make an unknown number of
calls to alloc_pages_vma() with one mempolicy; but since 00442ad04a5e,
alloc_pages_vma() has kept refcount in balance, so now no problem.

Reported-and-tested-by: Tommi Rantala <tt.rantala@gmail.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
cgroup: cgroup_subsys->fork() should be called after the task is added to css_set

commit 5edee61edeaaebafe584f8fb7074c1ef4658596b upstream.

cgroup core has a bug which violates a basic rule about event
notifications - when a new entity needs to be added, you add that to
the notification list first and then make the new entity conform to
the current state.  If done in the reverse order, an event happening
inbetween will be lost.

cgroup_subsys->fork() is invoked way before the new task is added to
the css_set.  Currently, cgroup_freezer is the only user of ->fork()
and uses it to make new tasks conform to the current state of the
freezer.  If FROZEN state is requested while fork is in progress
between cgroup_fork_callbacks() and cgroup_post_fork(), the child
could escape freezing - the cgroup isn't frozen when ->fork() is
called and the freezer couldn't see the new task on the css_set.

This patch moves cgroup_subsys->fork() invocation to
cgroup_post_fork() after the new task is added to the css_set.
cgroup_fork_callbacks() is removed.

Because now a task may be migrated during cgroup_subsys->fork(),
freezer_fork() is updated so that it adheres to the usual RCU locking
and the rather pointless comment on why locking can be different there
is removed (if it doesn't make anything simpler, why even bother?).

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
[bwh: Backported to 3.2:
 - Adjust context
 - Iterate over first CGROUP_BUILTIN_SUBSYS_COUNT elements of subsys
 - cgroup_subsys::fork takes cgroup_subsys pointer as first parameter]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
mm: add kmap_to_page()

This is extracted from Mel Gorman's commit 5a178119b0fb ('mm: add
support for direct_IO to highmem pages') upstream.

Required to backport commit b9cdc88df8e6 ('virtio: 9p: correctly pass
physical address to userspace for high pages').

Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
mm: highmem: export kmap_to_page for modules

commit f0263d2d222e9e25f2587e51a9dc58c6fb2a9352 upstream.

Some virtio device drivers (9p) need to translate high virtual addresses
to physical addresses, which are inserted into the virtqueue for
processing by userspace.

This patch exports the kmap_to_page symbol, so that the affected drivers
can be compiled as modules.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ARM: mm: use pteval_t to represent page protection values

commit 864aa04cd02979c2c755cb28b5f4fe56039171c0 upstream.

When updating the page protection map after calculating the user_pgprot
value, the base protection map is temporarily stored in an unsigned long
type, causing truncation of the protection bits when LPAE is enabled.
This effectively means that calls to mprotect() will corrupt the upper
page attributes, clearing the XN bit unconditionally.

This patch uses pteval_t to store the intermediate protection values,
preserving the upper bits for 64-bit descriptors.

Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
rcu: Fix batch-limit size problem

commit 878d7439d0f45a95869e417576774673d1fa243f upstream.

Commit 29c00b4a1d9e27 (rcu: Add event-tracing for RCU callback
invocation) added a regression in rcu_do_batch()

Under stress, RCU is supposed to allow to process all items in queue,
instead of a batch of 10 items (blimit), but an integer overflow makes
the effective limit being 1.  So, unless there is frequent idle periods
(during which RCU ignores batch limits), RCU can be forced into a
state where it cannot keep up with the callback-generation rate,
eventually resulting in OOM.

This commit therefore converts a few variables in rcu_do_batch() from
int to long to fix this problem, along with the module parameters
controlling the batch limits.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[bwh: Backported to 3.2:
 - Adjust context
 - Module parameters remain hidden from sysfs]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
cgroup: remove incorrect dget/dput() pair in cgroup_create_dir()

commit 175431635ec09b1d1bba04979b006b99e8305a83 upstream.

cgroup_create_dir() does weird dancing with dentry refcnt.  On
success, it gets and then puts it achieving nothing.  On failure, it
puts but there isn't no matching get anywhere leading to the following
oops if cgroup_create_file() fails for whatever reason.

  ------------[ cut here ]------------
  kernel BUG at /work/os/work/fs/dcache.c:552!
  invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
  Modules linked in:
  CPU 2
  Pid: 697, comm: mkdir Not tainted 3.7.0-rc4-work+ #3 Bochs Bochs
  RIP: 0010:[<ffffffff811d9c0c>]  [<ffffffff811d9c0c>] dput+0x1dc/0x1e0
  RSP: 0018:ffff88001a3ebef8  EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff88000e5b1ef8 RCX: 0000000000000403
  RDX: 0000000000000303 RSI: 2000000000000000 RDI: ffff88000e5b1f58
  RBP: ffff88001a3ebf18 R08: ffffffff82c76960 R09: 0000000000000001
  R10: ffff880015022080 R11: ffd9bed70f48a041 R12: 00000000ffffffea
  R13: 0000000000000001 R14: ffff88000e5b1f58 R15: 00007fff57656d60
  FS:  00007ff05fcb3800(0000) GS:ffff88001fd00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000004046f0 CR3: 000000001315f000 CR4: 00000000000006e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  Process mkdir (pid: 697, threadinfo ffff88001a3ea000, task ffff880015022080)
  Stack:
   ffff88001a3ebf48 00000000ffffffea 0000000000000001 0000000000000000
   ffff88001a3ebf38 ffffffff811cc889 0000000000000001 ffff88000e5b1ef8
   ffff88001a3ebf68 ffffffff811d1fc9 ffff8800198d7f18 ffff880019106ef8
  Call Trace:
   [<ffffffff811cc889>] done_path_create+0x19/0x50
   [<ffffffff811d1fc9>] sys_mkdirat+0x59/0x80
   [<ffffffff811d2009>] sys_mkdir+0x19/0x20
   [<ffffffff81be1e02>] system_call_fastpath+0x16/0x1b
  Code: 00 48 8d 90 18 01 00 00 48 89 93 c0 00 00 00 4c 89 a0 18 01 00 00 48 8b 83 a0 00 00 00 83 80 28 01 00 00 01 e8 e6 6f a0 00 eb 92 <0f> 0b 66 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 49 89 fe 41
  RIP  [<ffffffff811d9c0c>] dput+0x1dc/0x1e0
   RSP <ffff88001a3ebef8>
  ---[ end trace 1277bcfd9561ddb0 ]---

Fix it by dropping the unnecessary dget/dput() pair.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
mm: dmapool: use provided gfp flags for all dma_alloc_coherent() calls

commit 387870f2d6d679746020fa8e25ef786ff338dc98 upstream.

dmapool always calls dma_alloc_coherent() with GFP_ATOMIC flag,
regardless the flags provided by the caller. This causes excessive
pruning of emergency memory pools without any good reason. Additionaly,
on ARM architecture any driver which is using dmapools will sooner or
later  trigger the following error:
"ERROR: 256 KiB atomic DMA coherent pool is too small!
Please increase it with coherent_pool= kernel parameter!".
Increasing the coherent pool size usually doesn't help much and only
delays such error, because all GFP_ATOMIC DMA allocations are always
served from the special, very limited memory pool.

This patch changes the dmapool code to correctly use gfp flags provided
by the dmapool caller.

Reported-by: Soeren Moch <smoch@web.de>
Reported-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Soeren Moch <smoch@web.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Revert "mm: vmscan: fix endless loop in kswapd balancing"

This reverts commit 39d18dc4b8b0c000fa681cbae10ac3f8a132814b which
was commit 60cefed485a02bd99b6299dad70666fe49245da7 upstream.

This was not needed and is not suitable for 3.2.y.

Reported-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
defconfig: jb: regen