For !BIO_CLONED bio, we can use .bi_vcnt safely, but it
doesn't mean we can just simply return .bi_io_vec[.bi_vcnt - 1]
because the start postion may have been moved in the middle of
the bvec, such as splitting in the middle of bvec.

Fixes: 7bcd79ac(block: bio: introduce helpers to get the 1st and last bvec)
Cc: stable@vger.kernel.org
Reported-by: NKent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: NMing Lei <ming.lei@canonical.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Pull KVM fixes from Paolo Bonzini:
 "A few simple fixes for ARM, x86, PPC and generic code.

  The x86 MMU fix is a bit larger because the surrounding code needed a
  cleanup, but nothing worrisome"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: MMU: fix reserved bit check for ept=0/CR0.WP=0/CR4.SMEP=1/EFER.NX=0
  KVM: MMU: fix ept=0/pte.u=1/pte.w=0/CR0.WP=0/CR4.SMEP=1/EFER.NX=0 combo
  kvm: cap halt polling at exactly halt_poll_ns
  KVM: s390: correct fprs on SIGP (STOP AND) STORE STATUS
  KVM: VMX: disable PEBS before a guest entry
  KVM: PPC: Book3S HV: Sanitize special-purpose register values on guest exit

Pull arm64 fixes from Will Deacon:
 "I thought we were done for 4.5, but then the 64k-page chaps came
  crawling out of the woodwork.  *sigh*

  The vmemmap fix I sent for -rc7 caused a regression with 64k pages and
  sparsemem and at some point during the release cycle the new hugetlb
  code using contiguous ptes started failing the libhugetlbfs tests with
  64k pages enabled.

  So here are a couple of patches that fix the vmemmap alignment and
  disable the new hugetlb page sizes whilst a proper fix is being
  developed:

   - Temporarily disable huge pages built using contiguous ptes

   - Ensure vmemmap region is sufficiently aligned for sparsemem
     sections"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: hugetlb: partial revert of 66b3923a
  arm64: account for sparsemem section alignment when choosing vmemmap offset

Pull s390 fixes from Martin Schwidefsky:
 "Three bug fixes:
   - The fix for the page table corruption (CVE-2016-2143)
   - The diagnose statistics introduced a regression for the dasd diag
     driver
   - Boot crash on systems without the set-program-parameters facility"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/mm: four page table levels vs. fork
  s390/cpumf: Fix lpp detection
  s390/dasd: fix diag 0x250 inline assembly

KVM has special logic to handle pages with pte.u=1 and pte.w=0 when
CR0.WP=1.  These pages' SPTEs flip continuously between two states:
U=1/W=0 (user and supervisor reads allowed, supervisor writes not allowed)
and U=0/W=1 (supervisor reads and writes allowed, user writes not allowed).

When SMEP is in effect, however, U=0 will enable kernel execution of
this page.  To avoid this, KVM also sets NX=1 in the shadow PTE together
with U=0, making the two states U=1/W=0/NX=gpte.NX and U=0/W=1/NX=1.
When guest EFER has the NX bit cleared, the reserved bit check thinks
that the latter state is invalid; teach it that the smep_andnot_wp case
will also use the NX bit of SPTEs.

Cc: stable@vger.kernel.org
Reviewed-by: NXiao Guangrong <guangrong.xiao@linux.inel.com>
Fixes: c258b62bSigned-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Yes, all of these are needed. :) This is admittedly a bit odd, but
kvm-unit-tests access.flat tests this if you run it with "-cpu host"
and of course ept=0.

KVM runs the guest with CR0.WP=1, so it must handle supervisor writes
specially when pte.u=1/pte.w=0/CR0.WP=0.  Such writes cause a fault
when U=1 and W=0 in the SPTE, but they must succeed because CR0.WP=0.
When KVM gets the fault, it sets U=0 and W=1 in the shadow PTE and
restarts execution.  This will still cause a user write to fault, while
supervisor writes will succeed.  User reads will fault spuriously now,
and KVM will then flip U and W again in the SPTE (U=1, W=0).  User reads
will be enabled and supervisor writes disabled, going back to the
originary situation where supervisor writes fault spuriously.

When SMEP is in effect, however, U=0 will enable kernel execution of
this page.  To avoid this, KVM also sets NX=1 in the shadow PTE together
with U=0.  If the guest has not enabled NX, the result is a continuous
stream of page faults due to the NX bit being reserved.

The fix is to force EFER.NX=1 even if the CPU is taking care of the EFER
switch.  (All machines with SMEP have the CPU_LOAD_IA32_EFER vm-entry
control, so they do not use user-return notifiers for EFER---if they did,
EFER.NX would be forced to the same value as the host).

There is another bug in the reserved bit check, which I've split to a
separate patch for easier application to stable kernels.

Cc: stable@vger.kernel.org
Cc: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: NXiao Guangrong <guangrong.xiao@linux.intel.com>
Fixes: f6577a5fSigned-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The fork of a process with four page table levels is broken since
git commit 6252d702 "[S390] dynamic page tables."

All new mm contexts are created with three page table levels and
an asce limit of 4TB. If the parent has four levels dup_mmap will
add vmas to the new context which are outside of the asce limit.
The subsequent call to copy_page_range will walk the three level
page table structure of the new process with non-zero pgd and pud
indexes. This leads to memory clobbers as the pgd_index *and* the
pud_index is added to the mm->pgd pointer without a pgd_deref
in between.

The init_new_context() function is selecting the number of page
table levels for a new context. The function is used by mm_init()
which in turn is called by dup_mm() and mm_alloc(). These two are
used by fork() and exec(). The init_new_context() function can
distinguish the two cases by looking at mm->context.asce_limit,
for fork() the mm struct has been copied and the number of page
table levels may not change. For exec() the mm_alloc() function
set the new mm structure to zero, in this case a three-level page
table is created as the temporary stack space is located at
STACK_TOP_MAX = 4TB.

This fixes CVE-2016-2143.
Reported-by: NMarcin Kościelnicki <koriakin@0x04.net>
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Pull spi fixes from Mark Brown:
 "A few driver specific fixes for the Rockchip and i.MX SPI controllers,
  especially for the i.MX they're annoying bugs if you run into them"

* tag 'spi-fix-v4.5-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: imx: fix spi resource leak with dma transfer
  spi: imx: allow only WML aligned transfers to use DMA
  spi: rockchip: add missing spi_master_put
  spi: rockchip: disable runtime pm when in err case

Pull ext4 fix from Ted Ts'o:
 "This fixes a regression which crept in v4.5-rc5"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: iterate over buffer heads correctly in move_extent_per_page()

Pull drm fixes from Dave Airlie:
 "A few imx fixes I missed from a couple of weeks ago, they still aren't
  that big and fix some regression and a fail to boot problem.

  Other than that, a couple of regression fixes for radeon/amdgpu, one
  regression fix for vmwgfx and one regression fix for tda998x"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  Revert "drm/radeon/pm: adjust display configuration after powerstate"
  drm/amdgpu/dp: add back special handling for NUTMEG
  drm/radeon/dp: add back special handling for NUTMEG
  drm/i2c: tda998x: Choose between atomic or non atomic dpms helper
  drm/vmwgfx: Add back ->detect() and ->fill_modes()
  drm/radeon: Fix error handling in radeon_flip_work_func.
  drm/amdgpu: Fix error handling in amdgpu_flip_work_func.
  drm/imx: Add missing DRM_FORMAT_RGB565 to ipu_plane_formats
  drm/imx: notify DRM core about CRTC vblank state
  gpu: ipu-v3: Reset IPU before activating IRQ
  gpu: ipu-v3: Do not bail out on missing optional port nodes

Merge tag 'trace-fixes-v4.5-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "I previously sent a fix that prevents all trace events from being
  called if the current cpu is offline.

  But I forgot that in 3.18, we added lockdep checks to test RCU usage
  even when the event is disabled.  Although there cannot be any bug
  when a cpu is going offline, we now get false warnings triggered by
  the added checks of the event being disabled.

  I removed the check from the tracepoint code itself, and added it to
  the condition section (which is "1" for 'no condition').  This way the
  online cpu check will get checked in all the right locations"

* tag 'trace-fixes-v4.5-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix check for cpu online when event is disabled

In commit bcff2488 ("ext4: don't read blocks from disk after extents
being swapped") bh is not updated correctly in the for loop and wrong
data has been written to disk. generic/324 catches this on sub-page
block size ext4.

Fixes: bcff2488 ("ext4: don't read blocks from disk after extentsbeing swapped")
Signed-off-by: NEryu Guan <guaneryu@gmail.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Merge fixes from Andrew Morton:
 "13 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  dma-mapping: avoid oops when parameter cpu_addr is null
  mm/hugetlb: use EOPNOTSUPP in hugetlb sysctl handlers
  memremap: check pfn validity before passing to pfn_to_page()
  mm, thp: fix migration of PTE-mapped transparent huge pages
  dax: check return value of dax_radix_entry()
  ocfs2: fix return value from ocfs2_page_mkwrite()
  arm64: kasan: clear stale stack poison
  sched/kasan: remove stale KASAN poison after hotplug
  kasan: add functions to clear stack poison
  mm: fix mixed zone detection in devm_memremap_pages
  list: kill list_force_poison()
  mm: __delete_from_page_cache show Bad page if mapped
  mm/hugetlb: hugetlb_no_page: rate-limit warning message

To keep consistent with kfree, which tolerate ptr is NULL.  We do this
because sometimes we may use goto statement, so that success and failure
case can share parts of the code.  But unfortunately, dma_free_coherent
called with parameter cpu_addr is null will cause oops, such as showed
below:

  Unable to handle kernel paging request at virtual address ffffffc020d3b2b8
  pgd = ffffffc083a61000
  [ffffffc020d3b2b8] *pgd=0000000000000000, *pud=0000000000000000
  CPU: 4 PID: 1489 Comm: malloc_dma_1 Tainted: G           O    4.1.12 #1
  Hardware name: ARM64 (DT)
  PC is at __dma_free_coherent.isra.10+0x74/0xc8
  LR is at __dma_free+0x9c/0xb0
  Process malloc_dma_1 (pid: 1489, stack limit = 0xffffffc0837fc020)
  [...]
  Call trace:
    __dma_free_coherent.isra.10+0x74/0xc8
    __dma_free+0x9c/0xb0
    malloc_dma+0x104/0x158 [dma_alloc_coherent_mtmalloc]
    kthread+0xec/0xfc
Signed-off-by: NZhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace ENOTSUPP with EOPNOTSUPP.  If hugepages are not supported, this
value is propagated to userspace.  EOPNOTSUPP is part of uapi and is
widely supported by libc libraries.

It gives nicer message to user, rather than:

  # cat /proc/sys/vm/nr_hugepages
  cat: /proc/sys/vm/nr_hugepages: Unknown error 524

And also LTP's proc01 test was failing because this ret code (524)
was unexpected:

  proc01      1  TFAIL  :  proc01.c:396: read failed: /proc/sys/vm/nr_hugepages: errno=???(524): Unknown error 524
  proc01      2  TFAIL  :  proc01.c:396: read failed: /proc/sys/vm/nr_hugepages_mempolicy: errno=???(524): Unknown error 524
  proc01      3  TFAIL  :  proc01.c:396: read failed: /proc/sys/vm/nr_overcommit_hugepages: errno=???(524): Unknown error 524
Signed-off-by: NJan Stancek <jstancek@redhat.com>
Acked-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NHillf Danton <hillf.zj@alibaba-inc.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In memremap's helper function try_ram_remap(), we dereference a struct
page pointer that was derived from a PFN that is known to be covered by
a 'System RAM' iomem region, and is thus assumed to be a 'valid' PFN,
i.e., a PFN that has a struct page associated with it and is covered by
the kernel direct mapping.

However, the assumption that there is a 1:1 relation between the System
RAM iomem region and the kernel direct mapping is not universally valid
on all architectures, and on ARM and arm64, 'System RAM' may include
regions for which pfn_valid() returns false.

Generally speaking, both __va() and pfn_to_page() should only ever be
called on PFNs/physical addresses for which pfn_valid() returns true, so
add that check to try_ram_remap().
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We don't have native support of THP migration, so we have to split huge
page into small pages in order to migrate it to different node.  This
includes PTE-mapped huge pages.

I made mistake in refcounting patchset: we don't actually split
PTE-mapped huge page in queue_pages_pte_range(), if we step on head
page.

The result is that the head page is queued for migration, but none of
tail pages: putting head page on queue takes pin on the page and any
subsequent attempts of split_huge_pages() would fail and we skip queuing
tail pages.

unmap_and_move_huge_page() will eventually split the huge pages, but
only one of 512 pages would get migrated.

Let's fix the situation.

Fixes: 248db92d ("migrate_pages: try to split pages on queuing")
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

dax_pfn_mkwrite() previously wasn't checking the return value of the
call to dax_radix_entry(), which was a mistake.

Instead, capture this return value and return the appropriate VM_FAULT_
value.
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ocfs2_page_mkwrite() could mistakenly return error code instead of
mkwrite status value.  Fix it.
Signed-off-by: NJan Kara <jack@suse.cz>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Functions which the compiler has instrumented for KASAN place poison on
the stack shadow upon entry and remove this poison prior to returning.

In the case of cpuidle, CPUs exit the kernel a number of levels deep in
C code.  Any instrumented functions on this critical path will leave
portions of the stack shadow poisoned.

If CPUs lose context and return to the kernel via a cold path, we
restore a prior context saved in __cpu_suspend_enter are forgotten, and
we never remove the poison they placed in the stack shadow area by
functions calls between this and the actual exit of the kernel.

Thus, (depending on stackframe layout) subsequent calls to instrumented
functions may hit this stale poison, resulting in (spurious) KASAN
splats to the console.

To avoid this, clear any stale poison from the idle thread for a CPU
prior to bringing a CPU online.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Functions which the compiler has instrumented for KASAN place poison on
the stack shadow upon entry and remove this poision prior to returning.

In the case of CPU hotplug, CPUs exit the kernel a number of levels deep
in C code.  Any instrumented functions on this critical path will leave
portions of the stack shadow poisoned.

When a CPU is subsequently brought back into the kernel via a different
path, depending on stackframe, layout calls to instrumented functions
may hit this stale poison, resulting in (spurious) KASAN splats to the
console.

To avoid this, clear any stale poison from the idle thread for a CPU
prior to bringing a CPU online.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: NIngo Molnar <mingo@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Functions which the compiler has instrumented for ASAN place poison on
the stack shadow upon entry and remove this poison prior to returning.

In some cases (e.g. hotplug and idle), CPUs may exit the kernel a
number of levels deep in C code.  If there are any instrumented
functions on this critical path, these will leave portions of the idle
thread stack shadow poisoned.

If a CPU returns to the kernel via a different path (e.g. a cold
entry), then depending on stack frame layout subsequent calls to
instrumented functions may use regions of the stack with stale poison,
resulting in (spurious) KASAN splats to the console.

Contemporary GCCs always add stack shadow poisoning when ASAN is
enabled, even when asked to not instrument a function [1], so we can't
simply annotate functions on the critical path to avoid poisoning.

Instead, this series explicitly removes any stale poison before it can
be hit.  In the common hotplug case we clear the entire stack shadow in
common code, before a CPU is brought online.

On architectures which perform a cold return as part of cpu idle may
retain an architecture-specific amount of stack contents.  To retain the
poison for this retained context, the arch code must call the core KASAN
code, passing a "watermark" stack pointer value beyond which shadow will
be cleared.  Architectures which don't perform a cold return as part of
idle do not need any additional code.

This patch (of 3):

Functions which the compiler has instrumented for KASAN place poison on
the stack shadow upon entry and remove this poision prior to returning.

In some cases (e.g.  hotplug and idle), CPUs may exit the kernel a number
of levels deep in C code.  If there are any instrumented functions on this
critical path, these will leave portions of the stack shadow poisoned.

If a CPU returns to the kernel via a different path (e.g.  a cold entry),
then depending on stack frame layout subsequent calls to instrumented
functions may use regions of the stack with stale poison, resulting in
(spurious) KASAN splats to the console.

To avoid this, we must clear stale poison from the stack prior to
instrumented functions being called.  This patch adds functions to the
KASAN core for removing poison from (portions of) a task's stack.  These
will be used by subsequent patches to avoid problems with hotplug and
idle.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The check for whether we overlap "System RAM" needs to be done at
section granularity.  For example a system with the following mapping:

    100000000-37bffffff : System RAM
    37c000000-837ffffff : Persistent Memory

...is unable to use devm_memremap_pages() as it would result in two
zones colliding within a given section.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: NToshi Kani <toshi.kani@hpe.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Given we have uninitialized list_heads being passed to list_add() it
will always be the case that those uninitialized values randomly trigger
the poison value.  Especially since a list_add() operation will seed the
stack with the poison value for later stack allocations to trip over.

For example, see these two false positive reports:

  list_add attempted on force-poisoned entry
  WARNING: at lib/list_debug.c:34
  [..]
  NIP [c00000000043c390] __list_add+0xb0/0x150
  LR [c00000000043c38c] __list_add+0xac/0x150
  Call Trace:
    __list_add+0xac/0x150 (unreliable)
    __down+0x4c/0xf8
    down+0x68/0x70
    xfs_buf_lock+0x4c/0x150 [xfs]

  list_add attempted on force-poisoned entry(0000000000000500),
   new->next == d0000000059ecdb0, new->prev == 0000000000000500
  WARNING: at lib/list_debug.c:33
  [..]
  NIP [c00000000042db78] __list_add+0xa8/0x140
  LR [c00000000042db74] __list_add+0xa4/0x140
  Call Trace:
    __list_add+0xa4/0x140 (unreliable)
    rwsem_down_read_failed+0x6c/0x1a0
    down_read+0x58/0x60
    xfs_log_commit_cil+0x7c/0x600 [xfs]

Fixes: commit 5c2c2587 ("mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup")
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Reported-by: NEryu Guan <eguan@redhat.com>
Tested-by: NEryu Guan <eguan@redhat.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit e1534ae9 ("mm: differentiate page_mapped() from
page_mapcount() for compound pages") changed the famous
BUG_ON(page_mapped(page)) in __delete_from_page_cache() to
VM_BUG_ON_PAGE(page_mapped(page)): which gives us more info when
CONFIG_DEBUG_VM=y, but nothing at all when not.

Although it has not usually been very helpul, being hit long after the
error in question, we do need to know if it actually happens on users'
systems; but reinstating a crash there is likely to be opposed :)

In the non-debug case, pr_alert("BUG: Bad page cache") plus dump_page(),
dump_stack(), add_taint() - I don't really believe LOCKDEP_NOW_UNRELIABLE,
but that seems to be the standard procedure now.  Move that, or the
VM_BUG_ON_PAGE(), up before the deletion from tree: so that the
unNULLified page->mapping gives a little more information.

If the inode is being evicted (rather than truncated), it won't have any
vmas left, so it's safe(ish) to assume that the raised mapcount is
erroneous, and we can discount it from page_count to avoid leaking the
page (I'm less worried by leaking the occasional 4kB, than losing a
potential 2MB page with each 4kB page leaked).
Signed-off-by: NHugh Dickins <hughd@google.com>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The warning message "killed due to inadequate hugepage pool" simply
indicates that SIGBUS was sent, not that the process was forcibly killed.
If the process has a signal handler installed does not fix the problem,
this message can rapidly spam the kernel log.

On my amd64 dev machine that does not have hugepages configured, I can
reproduce the repeated warnings easily by setting vm.nr_hugepages=2 (i.e.,
4 megabytes of huge pages) and running something that sets a signal
handler and forks, like

  #include <sys/mman.h>
  #include <signal.h>
  #include <stdlib.h>
  #include <unistd.h>

  sig_atomic_t counter = 10;
  void handler(int signal)
  {
      if (counter-- == 0)
         exit(0);
  }

  int main(void)
  {
      int status;
      char *addr = mmap(NULL, 4 * 1048576, PROT_READ | PROT_WRITE,
              MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0);
      if (addr == MAP_FAILED) {perror("mmap"); return 1;}
      *addr = 'x';
      switch (fork()) {
         case -1:
            perror("fork"); return 1;
         case 0:
            signal(SIGBUS, handler);
            *addr = 'x';
            break;
         default:
            *addr = 'x';
            wait(&status);
            if (WIFSIGNALED(status)) {
               psignal(WTERMSIG(status), "child");
            }
            break;
      }
  }
Signed-off-by: NGeoffrey Thomas <geofft@ldpreload.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull PCI fix from Bjorn Helgaas:
 "Here's another fix for v4.5.  It fixes an ARM regression in v4.0 that
  causes many boxes to crash on boot, including cns3xxx, dove,
  footbridge, iopl13xx, ip32x, iop33x, ixp4xx, ks8695, mv78xx0, orion5x,
  pxa, sa1100, etc.

  The change is in code that's only built for ARM and ARM64.

  Summary:

  Enumeration:
    Allow generic PCI domains without bridge "parent" pointer (Krzysztof Hałasa)"

* tag 'pci-v4.5-fixes-5' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: Allow a NULL "parent" pointer in pci_bus_assign_domain_nr()

Commit f3775549 ("tracepoints: Do not trace when cpu is offline") added
a check to make sure that tracepoints only get called when the cpu is
online, as it uses rcu_read_lock_sched() for protection.

Commit 3a630178 ("tracing: generate RCU warnings even when tracepoints
are disabled") added lockdep checks (including rcu checks) for events that
are not enabled to catch possible RCU issues that would only be triggered if
a trace event was enabled. Commit f3775549 only stopped the warnings
when the trace event was enabled but did not prevent warnings if the trace
event was called when disabled.

To fix this, the cpu online check is moved to where the condition is added
to the trace event. This will place the cpu online check in all places that
it may be used now and in the future.

Cc: stable@vger.kernel.org # v3.18+
Fixes: f3775549 ("tracepoints: Do not trace when cpu is offline")
Fixes: 3a630178 ("tracing: generate RCU warnings even when tracepoints are disabled")
Reported-by: NSudeep Holla <sudeep.holla@arm.com>
Tested-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Commit 66b3923a ("arm64: hugetlb: add support for PTE contiguous bit")
introduced support for huge pages using the contiguous bit in the PTE
as opposed to block mappings, which may be slightly unwieldy (512M) in
64k page configurations.

Unfortunately, this support has resulted in some late regressions when
running the libhugetlbfs test suite with 64k pages and CONFIG_DEBUG_VM
as a result of a BUG:

 | readback (2M: 64):	------------[ cut here ]------------
 | kernel BUG at fs/hugetlbfs/inode.c:446!
 | Internal error: Oops - BUG: 0 [#1] SMP
 | Modules linked in:
 | CPU: 7 PID: 1448 Comm: readback Not tainted 4.5.0-rc7 #148
 | Hardware name: linux,dummy-virt (DT)
 | task: fffffe0040964b00 ti: fffffe00c2668000 task.ti: fffffe00c2668000
 | PC is at remove_inode_hugepages+0x44c/0x480
 | LR is at remove_inode_hugepages+0x264/0x480

Rather than revert the entire patch, simply avoid advertising the
contiguous huge page sizes for now while people are actively working on
a fix. This patch can then be reverted once things have been sorted out.

Cc: David Woods <dwoods@ezchip.com>
Reported-by: NSteve Capper <steve.capper@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Commit dfd55ad8 ("arm64: vmemmap: use virtual projection of linear
region") fixed an issue where the struct page array would overflow into the
adjacent virtual memory region if system RAM was placed so high up in
physical memory that its addresses were not representable in the build time
configured virtual address size.

However, the fix failed to take into account that the vmemmap region needs
to be relatively aligned with respect to the sparsemem section size, so that
a sequence of page structs corresponding with a sparsemem section in the
linear region appears naturally aligned in the vmemmap region.

So round up vmemmap to sparsemem section size. Since this essentially moves
the projection of the linear region up in memory, also revert the reduction
of the size of the vmemmap region.

Cc: <stable@vger.kernel.org>
Fixes: dfd55ad8 ("arm64: vmemmap: use virtual projection of linear region")
Tested-by: NMark Langsdorf <mlangsdo@redhat.com>
Tested-by: NDavid Daney <david.daney@cavium.com>
Tested-by: NRobert Richter <rrichter@cavium.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When growing halt-polling, there is no check that the poll time exceeds
the limit. It's possible for vcpu->halt_poll_ns grow once past
halt_poll_ns, and stay there until a halt which takes longer than
vcpu->halt_poll_ns. For example, booting a Linux guest with
halt_poll_ns=11000:

 ... kvm:kvm_halt_poll_ns: vcpu 0: halt_poll_ns 0 (shrink 10000)
 ... kvm:kvm_halt_poll_ns: vcpu 0: halt_poll_ns 10000 (grow 0)
 ... kvm:kvm_halt_poll_ns: vcpu 0: halt_poll_ns 20000 (grow 10000)
Signed-off-by: NDavid Matlack <dmatlack@google.com>
Fixes: aca6ff29
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

ipu-v3 probe and imx-drm crtc and plane fixes

- Fix ipu probe if optional port nodes are not present in the device tree
- Reset the ipu before initializing interrupts, not thereafter
- Notify DRM core about the state of vblank interrupts
- Add missing RGB565 format to the list of plate formats

* tag 'imx-drm-fixes-2016-02-19' of git://git.pengutronix.de/git/pza/linux:
  drm/imx: Add missing DRM_FORMAT_RGB565 to ipu_plane_formats
  drm/imx: notify DRM core about CRTC vblank state
  gpu: ipu-v3: Reset IPU before activating IRQ
  gpu: ipu-v3: Do not bail out on missing optional port nodes

radeon and amdgpu fixes for 4.5. Three regression fixes and
some fixups for the error handling in the vblank regression fixes
from earlier.

* 'drm-fixes-4.5' of git://people.freedesktop.org/~agd5f/linux:
  Revert "drm/radeon/pm: adjust display configuration after powerstate"
  drm/amdgpu/dp: add back special handling for NUTMEG
  drm/radeon/dp: add back special handling for NUTMEG
  drm/radeon: Fix error handling in radeon_flip_work_func.
  drm/amdgpu: Fix error handling in amdgpu_flip_work_func.

This reverts commit 39d42750.

This caused a regression on some older hardware.

bug:
https://bugzilla.kernel.org/show_bug.cgi?id=113891Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

Pull sound fixes from Takashi Iwai:
 "It's always an ambivalent feeling to send a large pull request at the
  late stage like this, especially when most of patches came from me.
  Anyway, this is a collection of lots of small fixes that slipped from
  the previous pull request.

  All fixes are about ASoC, and the majority of changes are corrections
  of the wrong access types in ALSA ctl enum items.  They are mostly
  harmless on 32bit architectures, but actually buggy on 64bit.  So we
  addressed all these now in a shot.  The rest are various small ASoC
  driver fixes.

  Among them, only two changes have been done to ASoC core, and both of
  them are trivial.  The rest are all device-specific.  So overall, they
  should be safe to apply"

* tag 'sound-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (33 commits)
  ASoC: wm_adsp: Fix enum ctl accesses in a wrong type
  ASoC: wm9081: Fix enum ctl accesses in a wrong type
  ASoC: wm8996: Fix enum ctl accesses in a wrong type
  ASoC: wm8994: Fix enum ctl accesses in a wrong type
  ASoC: wm8985: Fix enum ctl accesses in a wrong type
  ASoC: wm8983: Fix enum ctl accesses in a wrong type
  ASoC: wm8958: Fix enum ctl accesses in a wrong type
  ASoC: wm8904: Fix enum ctl accesses in a wrong type
  ASoC: wm8753: Fix enum ctl accesses in a wrong type
  ASoC: wl1273: Fix enum ctl accesses in a wrong type
  ASoC: tlv320dac33: Fix enum ctl accesses in a wrong type
  ASoC: max98095: Fix enum ctl accesses in a wrong type
  ASoC: max98088: Fix enum ctl accesses in a wrong type
  ASoC: ab8500: Fix enum ctl accesses in a wrong type
  ASoC: da732x: Fix enum ctl accesses in a wrong type
  ASoC: cs42l51: Fix enum ctl accesses in a wrong type
  ASoC: intel: mfld: Fix enum ctl accesses in a wrong type
  ASoC: omap: rx51: Fix enum ctl accesses in a wrong type
  ASoC: omap: n810: Fix enum ctl accesses in a wrong type
  ASoC: pxa: tosa: Fix enum ctl accesses in a wrong type
  ...

Pull EDAC fix from Borislav Petkov:
 "Last minute fix for sb_edac which fixes DIMM detection on certain Xeon
  Phi configurations:

  A single fix to the Xeon Phi section of sb_edac.  The issue was
  introduced during this merge window"

* tag 'edac_fix_for_4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
  EDAC, sb_edac: Fix logic when computing DIMM sizes on Xeon Phi

When I fixed the dp rate selection in:
3b73b168cffd9c392584d3f665021fa2190f8612
drm/amdgpu: fix dp link rate selection (v2)
I accidently dropped the special handling for NUTMEG
DP bridge chips.  They require a fixed link rate.
Reviewed-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NKen Wang <Qingqing.Wang@amd.com>
Reviewed-by: NHarry Wentland <harry.wentland@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

When I fixed the dp rate selection in:
092c96a8
drm/radeon: fix dp link rate selection (v2)
I accidently dropped the special handling for NUTMEG
DP bridge chips.  They require a fixed link rate.
Reviewed-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NKen Wang <Qingqing.Wang@amd.com>
Reviewed-by: NHarry Wentland <harry.wentland@amd.com>
Tested-by: NKen Moffat <zarniwhoop@ntlworld.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org