cgroup: fix unbalanced locking

cgroup_pidlist_start() holds cgrp->pidlist_mutex and then calls
pidlist_array_load(), and cgroup_pidlist_stop() releases the mutex.

It is wrong that we release the mutex in the failure path in
pidlist_array_load(), because cgroup_pidlist_stop() will be called
no matter if cgroup_pidlist_start() returns errno or not.

Fixes: 4bac00d16a8760eae7205e41d2c246477d42a210
Cc: <stable@vger.kernel.org> # 3.14+
Signed-off-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
arm/arm64: KVM: Fix unaligned access bug on gicv2 access

We were using an atomic bitop on the vgic_v2.vgic_elrsr field which was
not aligned to the natural size on 64-bit platforms.  This bug showed up
after QEMU correctly identifies the pl011 line as being level-triggered,
and not edge-triggered.

These data structures are protected by a spinlock so simply use a
non-atomic version of the accessor instead.

Tested-by: Joel Schopp <joel.schopp@amd.com>
Reported-by: Riku Voipio <riku.voipio@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Merge tag 'kvm-arm-for-v3.17-rc7-or-final' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master

Fixes unaligned access to the gicv2 virtual cpu status.
Merge branch 'for-3.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup fix from Tejun Heo:
 "One late fix for cgroup.

  I was waiting for another set of fixes for a long-standing obscure
   cpuset bug but am not sure whether they'll be ready before v3.17
  release.  This one is a simple fix for a mutex unlock balance bug in
  an allocation failure path in pidlist_array_load().

  The bug was introduced in v3.14 and the fix is tagged for -stable"

* 'for-3.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: fix unbalanced locking
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull another kvm fix from Paolo Bonzini:
 "Another fix for 3.17 arrived at just the wrong time, after I had sent
  yesterday's pull request.  Normally I would have waited for some other
  patches to pile up, but since 3.17 might be short here it is"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  arm/arm64: KVM: Fix unaligned access bug on gicv2 access