Otherwise lockdep says:

[ 1337.483798] ================================================
[ 1337.483999] [ BUG: lock held when returning to user space! ]
[ 1337.484252] 4.11.0-rc6 #19 Not tainted
[ 1337.484423] ------------------------------------------------
[ 1337.484626] mount/14766 is leaving the kernel with locks still held!
[ 1337.484841] 1 lock held by mount/14766:
[ 1337.485017]  #0:  (&type->s_umount_key#33/1){+.+.+.}, at: [<ffffffff8124171f>] sget_userns+0x2af/0x520

Caught by xfstests generic/413 which tried to mount with the unsupported
mount option dax.  Then xfstests generic/422 ran sync which deadlocks.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Acked-by: Mike Marshall <hubcap@omnibond.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Normal pathname lookup doesn't allow empty pathnames, but using
AT_EMPTY_PATH (with name_to_handle_at() or fstatat(), for example) you
can trigger an empty pathname lookup.

And not only is the RCU lookup in that case entirely unnecessary
(because we'll obviously immediately finalize the end result), it is
actively wrong.

Why? An empth path is a special case that will return the original
'dirfd' dentry - and that dentry may not actually be RCU-free'd,
resulting in a potential use-after-free if we were to initialize the
path lazily under the RCU read lock and depend on complete_walk()
finalizing the dentry.

Found by syzkaller and KASAN.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull input fixes from Dmitry Torokhov:
 "Just a small update to xpad driver to recognize yet another gamepad,
  and another change making sure userio.h is exported"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: xpad - add support for Razer Wildcat gamepad
  uapi: add missing install of userio.h

Pull networking fixes from David Miller:
 "Things seem to be settling down as far as networking is concerned,
  let's hope this trend continues...

   1) Add iov_iter_revert() and use it to fix the behavior of
      skb_copy_datagram_msg() et al., from Al Viro.

   2) Fix the protocol used in the synthetic SKB we cons up for the
      purposes of doing a simulated route lookup for RTM_GETROUTE
      requests. From Florian Larysch.

   3) Don't add noop_qdisc to the per-device qdisc hashes, from Cong
      Wang.

   4) Don't call netdev_change_features with the team lock held, from
      Xin Long.

   5) Revert TCP F-RTO extension to catch more spurious timeouts because
      it interacts very badly with some middle-boxes. From Yuchung
      Cheng.

   6) Fix the loss of error values in l2tp {s,g}etsockopt calls, from
      Guillaume Nault.

   7) ctnetlink uses bit positions where it should be using bit masks,
      fix from Liping Zhang.

   8) Missing RCU locking in netfilter helper code, from Gao Feng.

   9) Avoid double frees and use-after-frees in tcp_disconnect(), from
      Eric Dumazet.

  10) Don't do a changelink before we register the netdevice in
      bridging, from Ido Schimmel.

  11) Lock the ipv6 device address list properly, from Rabin Vincent"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (29 commits)
  netfilter: ipt_CLUSTERIP: Fix wrong conntrack netns refcnt usage
  netfilter: nft_hash: do not dump the auto generated seed
  drivers: net: usb: qmi_wwan: add QMI_QUIRK_SET_DTR for Telit PID 0x1201
  ipv6: Fix idev->addr_list corruption
  net: xdp: don't export dev_change_xdp_fd()
  bridge: netlink: register netdevice before executing changelink
  bridge: implement missing ndo_uninit()
  bpf: reference may_access_skb() from __bpf_prog_run()
  tcp: clear saved_syn in tcp_disconnect()
  netfilter: nf_ct_expect: use proper RCU list traversal/update APIs
  netfilter: ctnetlink: skip dumping expect when nfct_help(ct) is NULL
  netfilter: make it safer during the inet6_dev->addr_list traversal
  netfilter: ctnetlink: make it safer when checking the ct helper name
  netfilter: helper: Add the rcu lock when call __nf_conntrack_helper_find
  netfilter: ctnetlink: using bit to represent the ct event
  netfilter: xt_TCPMSS: add more sanity tests on tcph->doff
  net: tcp: Increase TCP_MIB_OUTRSTS even though fail to alloc skb
  l2tp: don't mask errors in pppol2tp_getsockopt()
  l2tp: don't mask errors in pppol2tp_setsockopt()
  tcp: restrict F-RTO to work-around broken middle-boxes
  ...

Pull x86 fixes from Thomas Gleixner:
 "A set of small fixes for x86:

   - fix locking in RDT to prevent memory leaks and freeing in use
     memory

   - prevent setting invalid values for vdso32_enabled which cause
     inconsistencies for user space resulting in application crashes.

   - plug a race in the vdso32 code between fork and sysctl which causes
     inconsistencies for user space resulting in application crashes.

   - make MPX signal delivery work in compat mode

   - make the dmesg output of traps and faults readable again"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/intel_rdt: Fix locking in rdtgroup_schemata_write()
  x86/debug: Fix the printk() debug output of signal_fault(), do_trap() and do_general_protection()
  x86/vdso: Plug race between mapping and ELF header setup
  x86/vdso: Ensure vdso32_enabled gets set to valid values only
  x86/signals: Fix lower/upper bound reporting in compat siginfo

Pull perf fixes from Thomas Gleixner:
 "Two small fixes for perf:

   - the move to support cross arch annotation introduced per arch
     initialization requirements, fullfill them for s/390 (Christian
     Borntraeger)

   - add the missing initialization to the LBR entries to avoid exposing
     random or stale data"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86: Avoid exposing wrong/stale data in intel_pmu_lbr_read_32()
  perf annotate s390: Fix perf annotate error -95 (4.10 regression)

Pull irq fixes from Thomas Gleixner:
 "The irq department provides:

   - two fixes for the CPU affinity spread infrastructure to prevent
     unbalanced spreading in corner cases which leads to horrible
     performance, because interrupts are rather aggregated than spread

   - add a missing spinlock initializer in the imx-gpcv2 init code"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/irq-imx-gpcv2: Fix spinlock initialization
  irq/affinity: Fix extra vecs calculation
  irq/affinity: Fix CPU spread for unbalanced nodes

Pull EFI fixes from Thomas Gleixner:
 "Three fixes from EFI land:

   - prevent accessing a Graphic Output Device (GOP) which the kernel
     does not know to handle

   - prevent PCI reconfiguration to modify a BAR which covers the
     framebuffer because that's already in use through the EFI GOP
     interface

   - avoid reserving EFI runtime regions as this results in bogus memory
     mappings"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/efi: Don't try to reserve runtime regions
  efi/fb: Avoid reconfiguration of BAR that covers the framebuffer
  efi/libstub: Skip GOP with PIXEL_BLT_ONLY format

Pull btrfs fixes from Chris Mason:
 "Dave Sterba collected a few more fixes for the last rc.

  These aren't marked for stable, but I'm putting them in with a batch
  were testing/sending by hand for this release"

* 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix potential use-after-free for cloned bio
  Btrfs: fix segmentation fault when doing dio read
  Btrfs: fix invalid dereference in btrfs_retry_endio
  btrfs: drop the nossd flag when remounting with -o ssd

Pull more CIFS fixes from Steve French:
 "As promised, here is the remaining set of cifs/smb3 fixes for stable
  (and a fix for one regression) now that they have had additional
  review and testing"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: Fix SMB3 mount without specifying a security mechanism
  CIFS: store results of cifs_reopen_file to avoid infinite wait
  CIFS: remove bad_network_name flag
  CIFS: reconnect thread reschedule itself
  CIFS: handle guest access errors to Windows shares
  CIFS: Fix null pointer deref during read resp processing

Pull fbdev fixes from Bartlomiej Zolnierkiewicz:

 - fix probing time checks in omapfb driver (regression fix)

 - fix optional VBAT support in ssd1307fb driver (regression fix)

 - fix connecting to backend in xen-fbfront driver

* tag 'fbdev-v4.11-rc6' of git://github.com/bzolnier/linux:
  fbdev: omapfb: delete check_required_callbacks()
  xen, fbfront: fix connecting to backend
  fbdev/ssd1307fb: fix optional VBAT support

Pull power management fixes from Rafael Wysocki:
 "These fix a cpufreq core regression related to CPU online/offline and
  several issues in the turbostat and cpupower utilities.

  Specifics:

   - Allow CPUs to be put back online even if the cpufreq driver is
     unable to work with them (eg. due to missing information from
     platform firmware), which was the previous behavior expected by
     users, but changed in the 4.9 time frame (Chen Yu).

   - Fix a few minor issues in the turbostat utility, introduced mostly
     during the recent update of it (Len Brown, Doug Smythies).

   - Fix a cpupower utility bug causing it to report incorrect values
     for turbo frequencies in some cases (Ben Hutchings)"

* tag 'pm-4.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpupower: Fix turbo frequency reporting for pre-Sandy Bridge cores
  cpufreq: Bring CPUs up even if cpufreq_online() failed
  tools/power turbostat: update version number
  tools/power turbostat: fix impossibly large CPU%c1 value
  tools/power turbostat: turbostat.8 add missing column definitions
  tools/power turbostat: update HWP dump to decimal from hex
  tools/power turbostat: enable package THERM_INTERRUPT dump
  tools/power turbostat: show missing Core and GFX power on SKL and KBL
  tools/power turbostat: bugfix: GFXMHz column not changing

Pull ACPI fixes from Rafael Wysocki:

 "These revert a recent ACPICA commit that turned out to be problematic
  and fix a device enumeration breakage from the 4.8 cycle.

  Specifics:

   - Revert a recent ACPICA commit targeted at catching firmware bugs
     which promptly did that and caused functional problems to appear
     (Rafael Wysocki).

   - Fix a device enumeration problem introduced in the 4.8 time frame
     which caused the ACPI docking station driver to report incorrect
     status via sysfs among other things (Rafael Wysocki)"

* tag 'acpi-4.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Revert "ACPICA: Resources: Not a valid resource if buffer length too long"
  ACPI / scan: Set the visited flag for all enumerated devices

Pull CONFIG_STRICT_DEVMEM fix from Kees Cook:
 "Fixes /dev/mem to read back zeros for System RAM areas in the 1MB
  exception area on x86 to avoid exposing RAM or tripping hardened
  usercopy"

* tag 'devmem-v4.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  mm: Tighten x86 /dev/mem with zeroing reads

Pull virtio fixes from Michael S. Tsirkin:
 "virtio oops fixes

  The virtio pci rework using shared interrupts caused a lot of issues.
  We tried to fix them but run out of time. Revert for now, and revisit
  the issue for the next kernel.

  Luckily we are able to do this without loosing automatic interrupt
  NUMA affinity which was the main motivator for the rework"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio-pci: Remove affinity hint before freeing the interrupt
  Revert "virtio_pci: remove struct virtio_pci_vq_info"
  Revert "virtio_pci: use shared interrupts for virtqueues"
  Revert "virtio_pci: don't duplicate the msix_enable flag in struct pci_dev"
  Revert "virtio_pci: simplify MSI-X setup"
  Revert "virtio_pci: fix out of bound access for msix_names"
  MAINTAINERS: fix virtio file pattern
  virtio_console: fix uninitialized variable use
  virtio_net: clear MTU when out of range
  virtio: allow drivers to validate features
  virtio_net: enable big packets for large MTU values

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for your net tree,
they are:

1) Missing TCP header sanity check in TCPMSS target, from Eric Dumazet.

2) Incorrect event message type for related conntracks created via
   ctnetlink, from Liping Zhang.

3) Fix incorrect rcu locking when handling helpers from ctnetlink,
   from Gao feng.

4) Fix missing rcu locking when updating helper, from Liping Zhang.

5) Fix missing read_lock_bh when iterating over list of device addresses
   from TPROXY and redirect, also from Liping.

6) Fix crash when trying to dump expectations from conntrack with no
   helper via ctnetlink, from Liping.

7) Missing RCU protection to expecation list update given ctnetlink
   iterates over the list under rcu read lock side, from Liping too.

8) Don't dump autogenerated seed in nft_hash to userspace, this is
   very confusing to the user, again from Liping.

9) Fix wrong conntrack netns module refcount in ipt_CLUSTERIP,
   from Gao feng.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 561eb9d0 ("fbdev: omap/lcd: Make callbacks optional") made
panel callbacks optional but forgot to update check_required_callbacks().
As a result many (all?) OMAP systems using omapfb will crash at boot.
Fix by deleting the whole function.

Fixes: 561eb9d0

 ("fbdev: omap/lcd: Make callbacks optional")
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

* acpi-scan-fixes:
  ACPI / scan: Set the visited flag for all enumerated devices

* acpica-fixes:
  Revert "ACPICA: Resources: Not a valid resource if buffer length too long"

* pm-cpufreq-fixes:
  cpufreq: Bring CPUs up even if cpufreq_online() failed

* pm-tools-fixes:
  cpupower: Fix turbo frequency reporting for pre-Sandy Bridge cores
  tools/power turbostat: update version number
  tools/power turbostat: fix impossibly large CPU%c1 value
  tools/power turbostat: turbostat.8 add missing column definitions
  tools/power turbostat: update HWP dump to decimal from hex
  tools/power turbostat: enable package THERM_INTERRUPT dump
  tools/power turbostat: show missing Core and GFX power on SKL and KBL
  tools/power turbostat: bugfix: GFXMHz column not changing

The raw_spinlock in the IMX GPCV2 interupt chip is not initialized before
usage. That results in a lockdep splat:

  INFO: trying to register non-static key.
  the code is fine but needs lockdep annotation.
  turning off the locking correctness validator.

Add the missing raw_spin_lock_init() to the setup code.

Fixes: e324c4dc

 ("irqchip/imx-gpcv2: IMX GPCv2 driver for wakeup sources")
Signed-off-by: Tyler Baker <tyler.baker@linaro.org>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Cc: jason@lakedaemon.net
Cc: marc.zyngier@arm.com
Cc: shawnguo@kernel.org
Cc: andrew.smirnov@gmail.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170413222731.5917-1-tyler.baker@linaro.org


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

When the perf_branch_entry::{in_tx,abort,cycles} fields were added,
intel_pmu_lbr_read_32() wasn't updated to initialize them.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Cc: <stable@vger.kernel.org>
Fixes: 135c5612

 ("perf/x86/intel: Support Haswell/v4 LBR format")
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge fixes from Andrew Morton:
 "11 fixes.

  The presence of 'thp: reduce indentation level in change_huge_pmd()'
  is unfortunate. But the patchset had been decently reviewed and tested
  before we decided it was needed in -stable and I felt it best not to
  churn things at the last minute"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mailmap: add Martin Kepplinger's email
  zsmalloc: expand class bit
  zram: do not use copy_page with non-page aligned address
  zram: fix operator precedence to get offset
  hugetlbfs: fix offset overflow in hugetlbfs mmap
  thp: fix MADV_DONTNEED vs clear soft dirty race
  thp: fix MADV_DONTNEED vs. MADV_FREE race
  mm: drop unused pmdp_huge_get_and_clear_notify()
  thp: fix MADV_DONTNEED vs. numa balancing race
  thp: reduce indentation level in change_huge_pmd()
  z3fold: fix page locking in z3fold_alloc()

Set the partly deprecated companies' email addresses as alias for the
personal one.

Link: http://lkml.kernel.org/r/1491984622-17321-1-git-send-email-martin.kepplinger@ginzinger.com


Signed-off-by: Martin Kepplinger <martin.kepplinger@ginzinger.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Now 64K page system, zsamlloc has 257 classes so 8 class bit is not
enough.  With that, it corrupts the system when zsmalloc stores
65536byte data(ie, index number 256) so that this patch increases class
bit for simple fix for stable backport.  We should clean up this mess
soon.

  index	size
  0	32
  1	288
  ..
  ..
  204	52256
  256	65536

Fixes: 3783689a ("zsmalloc: introduce zspage structure")
Link: http://lkml.kernel.org/r/1492042622-12074-3-git-send-email-minchan@kernel.org


Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The copy_page is optimized memcpy for page-alinged address.  If it is
used with non-page aligned address, it can corrupt memory which means
system corruption.  With zram, it can happen with

1. 64K architecture
2. partial IO
3. slub debug

Partial IO need to allocate a page and zram allocates it via kmalloc.
With slub debug, kmalloc(PAGE_SIZE) doesn't return page-size aligned
address.  And finally, copy_page(mem, cmem) corrupts memory.

So, this patch changes it to memcpy.

Actuaully, we don't need to change zram_bvec_write part because zsmalloc
returns page-aligned address in case of PAGE_SIZE class but it's not
good to rely on the internal of zsmalloc.

Note:
 When this patch is merged to stable, clear_page should be fixed, too.
 Unfortunately, recent zram removes it by "same page merge" feature so
 it's hard to backport this patch to -stable tree.

I will handle it when I receive the mail from stable tree maintainer to
merge this patch to backport.

Fixes: 42e99bd9 ("zram: optimize memory operations with clear_page()/copy_page()")
Link: http://lkml.kernel.org/r/1492042622-12074-2-git-send-email-minchan@kernel.org


Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In zram_rw_page, the logic to get offset is wrong by operator precedence
(i.e., "<<" is higher than "&").  With wrong offset, zram can corrupt
the user's data.  This patch fixes it.

Fixes: 8c7f0102 ("zram: implement rw_page operation of zram")
Link: http://lkml.kernel.org/r/1492042622-12074-1-git-send-email-minchan@kernel.org


Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If mmap() maps a file, it can be passed an offset into the file at which
the mapping is to start.  Offset could be a negative value when
represented as a loff_t.  The offset plus length will be used to update
the file size (i_size) which is also a loff_t.

Validate the value of offset and offset + length to make sure they do
not overflow and appear as negative.

Found by syzcaller with commit ff8c0c53 ("mm/hugetlb.c: don't call
region_abort if region_chg fails") applied.  Prior to this commit, the
overflow would still occur but we would luckily return ENOMEM.

To reproduce:

   mmap(0, 0x2000, 0, 0x40021, 0xffffffffffffffffULL, 0x8000000000000000ULL);

Resulted in,

  kernel BUG at mm/hugetlb.c:742!
  Call Trace:
   hugetlbfs_evict_inode+0x80/0xa0
   evict+0x24a/0x620
   iput+0x48f/0x8c0
   dentry_unlink_inode+0x31f/0x4d0
   __dentry_kill+0x292/0x5e0
   dput+0x730/0x830
   __fput+0x438/0x720
   ____fput+0x1a/0x20
   task_work_run+0xfe/0x180
   exit_to_usermode_loop+0x133/0x150
   syscall_return_slowpath+0x184/0x1c0
   entry_SYSCALL_64_fastpath+0xab/0xad

Fixes: ff8c0c53 ("mm/hugetlb.c: don't call region_abort if region_chg fails")
Link: http://lkml.kernel.org/r/1491951118-30678-1-git-send-email-mike.kravetz@oracle.com


Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Yet another instance of the same race.

Fix is identical to change_huge_pmd().

See "thp: fix MADV_DONTNEED vs.  numa balancing race" for more details.

Link: http://lkml.kernel.org/r/20170302151034.27829-5-kirill.shutemov@linux.intel.com


Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Both MADV_DONTNEED and MADV_FREE handled with down_read(mmap_sem).

It's critical to not clear pmd intermittently while handling MADV_FREE
to avoid race with MADV_DONTNEED:

	CPU0:				CPU1:
				madvise_free_huge_pmd()
				 pmdp_huge_get_and_clear_full()
madvise_dontneed()
 zap_pmd_range()
  pmd_trans_huge(*pmd) == 0 (without ptl)
  // skip the pmd
				 set_pmd_at();
				 // pmd is re-established

It results in MADV_DONTNEED skipping the pmd, leaving it not cleared.
It violates MADV_DONTNEED interface and can result is userspace
misbehaviour.

Basically it's the same race as with numa balancing in
change_huge_pmd(), but a bit simpler to mitigate: we don't need to
preserve dirty/young flags here due to MADV_FREE functionality.

[kirill.shutemov@linux.intel.com: Urgh... Power is special again]
  Link: http://lkml.kernel.org/r/20170303102636.bhd2zhtpds4mt62a@black.fi.intel.com
Link: http://lkml.kernel.org/r/20170302151034.27829-4-kirill.shutemov@linux.intel.com


Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Dave noticed that after fixing MADV_DONTNEED vs numa balancing race the
last pmdp_huge_get_and_clear_notify() user is gone.

Let's drop the helper.

Link: http://lkml.kernel.org/r/20170306112047.24809-1-kirill.shutemov@linux.intel.com


Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In case prot_numa, we are under down_read(mmap_sem).  It's critical to
not clear pmd intermittently to avoid race with MADV_DONTNEED which is
also under down_read(mmap_sem):

	CPU0:				CPU1:
				change_huge_pmd(prot_numa=1)
				 pmdp_huge_get_and_clear_notify()
madvise_dontneed()
 zap_pmd_range()
  pmd_trans_huge(*pmd) == 0 (without ptl)
  // skip the pmd
				 set_pmd_at();
				 // pmd is re-established

The race makes MADV_DONTNEED miss the huge pmd and don't clear it
which may break userspace.

Found by code analysis, never saw triggered.

Link: http://lkml.kernel.org/r/20170302151034.27829-3-kirill.shutemov@linux.intel.com


Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "thp: fix few MADV_DONTNEED races"

For MADV_DONTNEED to work properly with huge pages, it's critical to not
clear pmd intermittently unless you hold down_write(mmap_sem).

Otherwise MADV_DONTNEED can miss the THP which can lead to userspace
breakage.

See example of such race in commit message of patch 2/4.

All these races are found by code inspection.  I haven't seen them
triggered.  I don't think it's worth to apply them to stable@.

This patch (of 4):

Restructure code in preparation for a fix.

Link: http://lkml.kernel.org/r/20170302151034.27829-2-kirill.shutemov@linux.intel.com


Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Stress testing of the current z3fold implementation on a 8-core system
revealed it was possible that a z3fold page deleted from its unbuddied
list in z3fold_alloc() would be put on another unbuddied list by
z3fold_free() while z3fold_alloc() is still processing it.  This has
been introduced with commit 5a27aa82

 ("z3fold: add kref refcounting")
due to the removal of special handling of a z3fold page not on any list
in z3fold_free().

To fix this, the z3fold page lock should be taken in z3fold_alloc()
before the pool lock is released.  To avoid deadlocking, we just try to
lock the page as soon as we get a hold of it, and if trylock fails, we
drop this page and take the next one.

Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: <Oleksiy.Avramchenko@sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The ia64 build generates many warnings like this:

   WARNING: EXPORT symbol "empty_zero_page" [vmlinux] version generation failed, symbol will not be versioned.

Besides adding the necessary header this also requires fiddling with
some explicit .S -> .o rules.

Cc: IA64-ML <linux-ia64@vger.kernel.org>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This fixes a math error calculating the extra_vecs. The error assumed
only 1 cpu per vector, but the value needs to account for the actual
number of cpus per vector in order to get the correct remainder for
extra CPU assignment.

Fixes: 7bf8222b

 ("irq/affinity: Fix CPU spread for unbalanced nodes")
Reported-by: Xiaolong Ye <xiaolong.ye@intel.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Link: http://lkml.kernel.org/r/1492104492-19943-1-git-send-email-keith.busch@intel.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Current codes invoke wrongly nf_ct_netns_get in the destroy routine,
it should use nf_ct_netns_put, not nf_ct_netns_get.
It could cause some modules could not be unloaded.

Fixes: ecb2421b

 ("netfilter: add and use nf_ct_netns_get/put")
Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

This can prevent the nft utility from printing out the auto generated
seed to the user, which is unnecessary and confusing.

Fixes: cb1b69b0

 ("netfilter: nf_tables: add hash expression")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Telit LE920A4 uses the same pid 0x1201 of LE920, but modem
implementation is different, since it requires DTR to be set for
answering to qmi messages.

This patch replaces QMI_FIXED_INTF with QMI_QUIRK_SET_DTR: tests on
LE920 have been performed in order to verify backward compatibility.

Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Revert commit 57707a9a (ACPICA: Resources: Not a valid resource if
buffer length too long) as it is reported to prevent the TPM module
from loading on Lenovo X60 with Coreboot.

It also causes new confusing warnings to show up in the kernel log.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=195311


Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Pull pin control fixes from Linus Walleij:
 "Two pin control fixes arriving late, these are hopefully the last pin
  control fixes I send this kernel cycle. A Chromebook and an Exynos SoC
  thingie.

  The Exynos patch is pretty big, it is fixing unbroken a breakage
  caused by yours truly when trying to figure out the merge mess with
  the different Samsung platforms for this merge window. Sorry about
  that. We have countered this situation by assigning a Samsung pin
  control submaintainer to catch stuff earlier.

  Summary:

   - Make the Acer Chromebook keyboard work again with the Intel
     Cherryview driver.

   - Fix a merge error in the Exynos 5433 driver"

* tag 'pinctrl-v4.11-5' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  pinctrl: cherryview: Add a quirk to make Acer Chromebook keyboard work again
  pinctrl: samsung: Add missing part for PINCFG_TYPE_DRV of Exynos5433