Set the page dirty if VM_WRITE is not set because in such case the pte
won't be marked dirty and the page would be reclaimed without writepage
(i.e.  swapout in the shmem case).

This was found by source review.  Most apps (certainly including QEMU)
only use UFFDIO_COPY on PROT_READ|PROT_WRITE mappings or the app can't
modify the memory in the first place.  This is for correctness and it
could help the non cooperative use case to avoid unexpected data loss.

Link: http://lkml.kernel.org/r/20181126173452.26955-6-aarcange@redhat.comReviewed-by: Hugh Dickins <hughd@google.com>
Cc: stable@vger.kernel.org
Fixes: 4c27fe4c ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support")
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

With MAP_SHARED: recheck the i_size after taking the PT lock, to
serialize against truncate with the PT lock.  Delete the page from the
pagecache if the i_size_read check fails.

With MAP_PRIVATE: check the i_size after the PT lock before mapping
anonymous memory or zeropages into the MAP_PRIVATE shmem mapping.

A mostly irrelevant cleanup: like we do the delete_from_page_cache()
pagecache removal after dropping the PT lock, the PT lock is a spinlock
so drop it before the sleepable page lock.

Link: http://lkml.kernel.org/r/20181126173452.26955-5-aarcange@redhat.com
Fixes: 4c27fe4c ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Hugh Dickins <hughd@google.com>
Reported-by: Jann Horn <jannh@google.com>
Cc: <stable@vger.kernel.org>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

After the VMA to register the uffd onto is found, check that it has
VM_MAYWRITE set before allowing registration.  This way we inherit all
common code checks before allowing to fill file holes in shmem and
hugetlbfs with UFFDIO_COPY.

The userfaultfd memory model is not applicable for readonly files unless
it's a MAP_PRIVATE.

Link: http://lkml.kernel.org/r/20181126173452.26955-4-aarcange@redhat.com
Fixes: ff62a342 ("hugetlb: implement memfd sealing")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Hugh Dickins <hughd@google.com>
Reported-by: Jann Horn <jannh@google.com>
Fixes: 4c27fe4c ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support")
Cc: <stable@vger.kernel.org>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Userfaultfd did not create private memory when UFFDIO_COPY was invoked
on a MAP_PRIVATE shmem mapping.  Instead it wrote to the shmem file,
even when that had not been opened for writing.  Though, fortunately,
that could only happen where there was a hole in the file.

Fix the shmem-backed implementation of UFFDIO_COPY to create private
memory for MAP_PRIVATE mappings.  The hugetlbfs-backed implementation
was already correct.

This change is visible to userland, if userfaultfd has been used in
unintended ways: so it introduces a small risk of incompatibility, but
is necessary in order to respect file permissions.

An app that uses UFFDIO_COPY for anything like postcopy live migration
won't notice the difference, and in fact it'll run faster because there
will be no copy-on-write and memory waste in the tmpfs pagecache
anymore.

Userfaults on MAP_PRIVATE shmem keep triggering only on file holes like
before.

The real zeropage can also be built on a MAP_PRIVATE shmem mapping
through UFFDIO_ZEROPAGE and that's safe because the zeropage pte is
never dirty, in turn even an mprotect upgrading the vma permission from
PROT_READ to PROT_READ|PROT_WRITE won't make the zeropage pte writable.

Link: http://lkml.kernel.org/r/20181126173452.26955-3-aarcange@redhat.com
Fixes: 4c27fe4c ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.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 "userfaultfd shmem updates".

Jann found two bugs in the userfaultfd shmem MAP_SHARED backend: the
lack of the VM_MAYWRITE check and the lack of i_size checks.

Then looking into the above we also fixed the MAP_PRIVATE case.

Hugh by source review also found a data loss source if UFFDIO_COPY is
used on shmem MAP_SHARED PROT_READ mappings (the production usages
incidentally run with PROT_READ|PROT_WRITE, so the data loss couldn't
happen in those production usages like with QEMU).

The whole patchset is marked for stable.

We verified QEMU postcopy live migration with guest running on shmem
MAP_PRIVATE run as well as before after the fix of shmem MAP_PRIVATE.
Regardless if it's shmem or hugetlbfs or MAP_PRIVATE or MAP_SHARED, QEMU
unconditionally invokes a punch hole if the guest mapping is filebacked
and a MADV_DONTNEED too (needed to get rid of the MAP_PRIVATE COWs and
for the anon backend).

This patch (of 5):

We internally used EFAULT to communicate with the caller, switch to
ENOENT, so EFAULT can be used as a non internal retval.

Link: http://lkml.kernel.org/r/20181126173452.26955-2-aarcange@redhat.com
Fixes: 4c27fe4c ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Hugh Dickins <hughd@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Jann Horn <jannh@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: <stable@vger.kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We free the misc device string twice on rmmod; fix this.  Without this
we cannot remove the module without crashing.

Link: http://lkml.kernel.org/r/20181124050500.5257-1-mcgrof@kernel.orgSigned-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@vger.kernel.org>	[4.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

hfs_bmap_free() frees node via hfs_bnode_put(node).  However it then
reads node->this when dumping error message on an error path, which may
result in a use-after-free bug.  This patch frees node only when it is
never used.

Link: http://lkml.kernel.org/r/1543053441-66942-1-git-send-email-bianpan2016@163.comSigned-off-by: Pan Bian <bianpan2016@163.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Ernesto A. Fernandez <ernesto.mnd.fernandez@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

hfs_bmap_free() frees the node via hfs_bnode_put(node).  However, it
then reads node->this when dumping error message on an error path, which
may result in a use-after-free bug.  This patch frees the node only when
it is never again used.

Link: http://lkml.kernel.org/r/1542963889-128825-1-git-send-email-bianpan2016@163.com
Fixes: a1185ffa2fc ("HFS rewrite")
Signed-off-by: Pan Bian <bianpan2016@163.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joe Perches <joe@perches.com>
Cc: Ernesto A. Fernandez <ernesto.mnd.fernandez@gmail.com>
Cc: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Turns out that /proc has official documentation and people even trying
to keep it uptodate.

Link: http://lkml.kernel.org/r/20181116134630.GA8004@avx2Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init_currently_empty_zone() will adjust pgdat->nr_zones and set it to
'zone_idx(zone) + 1' unconditionally.  This is correct in the normal
case, while not exact in hot-plug situation.

This function is used in two places:

  * free_area_init_core()
  * move_pfn_range_to_zone()

In the first case, we are sure zone index increase monotonically.  While
in the second one, this is under users control.

One way to reproduce this is:
----------------------------

1. create a virtual machine with empty node1

   -m 4G,slots=32,maxmem=32G \
   -smp 4,maxcpus=8          \
   -numa node,nodeid=0,mem=4G,cpus=0-3 \
   -numa node,nodeid=1,mem=0G,cpus=4-7

2. hot-add cpu 3-7

   cpu-add [3-7]

2. hot-add memory to nod1

   object_add memory-backend-ram,id=ram0,size=1G
   device_add pc-dimm,id=dimm0,memdev=ram0,node=1

3. online memory with following order

   echo online_movable > memory47/state
   echo online > memory40/state

After this, node1 will have its nr_zones equals to (ZONE_NORMAL + 1)
instead of (ZONE_MOVABLE + 1).

Michal said:
 "Having an incorrect nr_zones might result in all sorts of problems
  which would be quite hard to debug (e.g. reclaim not considering the
  movable zone). I do not expect many users would suffer from this it
  but still this is trivial and obviously right thing to do so
  backporting to the stable tree shouldn't be harmful (last famous
  words)"

Link: http://lkml.kernel.org/r/20181117022022.9956-1-richard.weiyang@gmail.com
Fixes: f1dd2cd1 ("mm, memory_hotplug: do not associate hotadded memory to zones until online")
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We changed the key of swap cache tree from swp_entry_t.val to
swp_offset.  We need to do so in shmem_replace_page() as well.

Hugh said:
 "shmem_replace_page() has been wrong since the day I wrote it: good
  enough to work on swap "type" 0, which is all most people ever use
  (especially those few who need shmem_replace_page() at all), but
  broken once there are any non-0 swp_type bits set in the higher order
  bits"

Link: http://lkml.kernel.org/r/20181121215442.138545-1-yuzhao@google.com
Fixes: f6ab1f7f ("mm, swap: use offset of swap entry as key of swap cache")
Signed-off-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>	[4.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If all pages are deleted from the mapping by memory reclaim and also
moved to the cleancache:

__delete_from_page_cache
  (no shadow case)
  unaccount_page_cache_page
    cleancache_put_page
  page_cache_delete
    mapping->nrpages -= nr
    (nrpages becomes 0)

We don't clean the cleancache for an inode after final file truncation
(removal).

truncate_inode_pages_final
  check (nrpages || nrexceptional) is false
    no truncate_inode_pages
      no cleancache_invalidate_inode(mapping)

These way when reading the new file created with same inode we may get
these trash leftover pages from cleancache and see wrong data instead of
the contents of the new file.

Fix it by always doing truncate_inode_pages which is already ready for
nrpages == 0 && nrexceptional == 0 case and just invalidates inode.

[akpm@linux-foundation.org: add comment, per Jan]
Link: http://lkml.kernel.org/r/20181112095734.17979-1-ptikhomirov@virtuozzo.com
Fixes: commit 91b0abe3 ("mm + fs: store shadow entries in page cache")
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Reviewed-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andi Kleen <ak@linux.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>

ocfs2_defrag_extent may fall into deadlock.

ocfs2_ioctl_move_extents
    ocfs2_ioctl_move_extents
      ocfs2_move_extents
        ocfs2_defrag_extent
          ocfs2_lock_allocators_move_extents

            ocfs2_reserve_clusters
              inode_lock GLOBAL_BITMAP_SYSTEM_INODE

	  __ocfs2_flush_truncate_log
              inode_lock GLOBAL_BITMAP_SYSTEM_INODE

As backtrace shows above, ocfs2_reserve_clusters() will call inode_lock
against the global bitmap if local allocator has not sufficient cluters.
Once global bitmap could meet the demand, ocfs2_reserve_cluster will
return success with global bitmap locked.

After ocfs2_reserve_cluster(), if truncate log is full,
__ocfs2_flush_truncate_log() will definitely fall into deadlock because
it needs to inode_lock global bitmap, which has already been locked.

To fix this bug, we could remove from
ocfs2_lock_allocators_move_extents() the code which intends to lock
global allocator, and put the removed code after
__ocfs2_flush_truncate_log().

ocfs2_lock_allocators_move_extents() is referred by 2 places, one is
here, the other does not need the data allocator context, which means
this patch does not affect the caller so far.

Link: http://lkml.kernel.org/r/20181101071422.14470-1-lchen@suse.comSigned-off-by: Larry Chen <lchen@suse.com>
Reviewed-by: Changwei Ge <ge.changwei@h3c.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit df06b37f ("mm/gup: cache dev_pagemap while pinning pages")
attempted to operate on each page that get_user_pages had retrieved.  In
order to do that, it created a common exit point from the routine.
However, one case was missed, which this patch fixes up.

Also, there was still an unnecessary shadow declaration (with a
different type) of the "ret" variable, which this patch removes.

Keith's description of the situation is:

  This also fixes a potentially leaked dev_pagemap reference count if a
  failure occurs when an iteration crosses a vma boundary.  I don't think
  it's normal to have different vma's on a users mapped zone device
  memory, but good to fix anyway.

I actually thought that this code:

    /* first iteration or cross vma bound */
    if (!vma || start >= vma->vm_end) {
	        vma = find_extend_vma(mm, start);
	        if (!vma && in_gate_area(mm, start)) {
		            ret = get_gate_page(mm, start & PAGE_MASK,
		                    gup_flags, &vma,
		                    pages ? &pages[i] : NULL);
		            if (ret)
		                goto out;

dealt with the "you're trying to pin the gate page, as part of this
call", rather than the generic case of crossing a vma boundary.  (I
think there's a fine point that I must be overlooking.) But it's still a
valid case, either way.

Link: http://lkml.kernel.org/r/20181121081402.29641-2-jhubbard@nvidia.com
Fixes: df06b37f ("mm/gup: cache dev_pagemap while pinning pages")
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

My name has changed, works better than Global Entry I tell ya.

Link: http://lkml.kernel.org/r/20181122003138.7752-1-mcgrof@kernel.orgSigned-off-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull char/misc fixes from Greg KH:
 "Here are a few small char/misc driver fixes for 4.20-rc5 that resolve
  a number of reported issues.

  The "largest" here is the thunderbolt patch, which resolves an issue
  with NVM upgrade, the smallest being some fsi driver fixes. There's
  also a hyperv bugfix, and the usual binder bugfixes.

  All of these have been in linux-next with no reported issues"

* tag 'char-misc-4.20-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  misc: mic/scif: fix copy-paste error in scif_create_remote_lookup
  thunderbolt: Prevent root port runtime suspend during NVM upgrade
  Drivers: hv: vmbus: check the creation_status in vmbus_establish_gpadl()
  binder: fix race that allows malicious free of live buffer
  fsi: fsi-scom.c: Remove duplicate header
  fsi: master-ast-cf: select GENERIC_ALLOCATOR

Merge tag 'driver-core-4.20-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fix from Greg KH:
 "Here is a single driver core fix for 4.20-rc5

  It resolves an issue with the data alignment in 'struct devres' for
  the ARC platform. The full details are in the commit changelog, but
  the short summary is the change is a single line:

	-       unsigned long long              data[]; /* guarantee ull alignment */
	+       u8 __aligned(ARCH_KMALLOC_MINALIGN) data[];

  This has been in linux-next for a while with no reported issues"

* tag 'driver-core-4.20-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  devres: Align data[] to ARCH_KMALLOC_MINALIGN

Pull staging and IIO driver fixes from Greg KH:
 "Here are some small IIO and staging driver fixes for 4.20-rc5.

  Nothing major, the IIO fix ended up touching the HID drivers at the
  same time, but the HID maintainer acked it. The staging fixes are all
  minor patches for reported issues and regressions, full details are in
  the shortlog.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'staging-4.20-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio/hid-sensors: Fix IIO_CHAN_INFO_RAW returning wrong values for signed numbers
  staging: vchiq_arm: fix compat VCHIQ_IOC_AWAIT_COMPLETION
  staging: mt7621-pinctrl: fix uninitialized variable ngroups
  staging: rtl8723bs: Add missing return for cfg80211_rtw_get_station
  staging: most: use format specifier "%s" in snprintf
  staging: rtl8723bs: Fix incorrect sense of ether_addr_equal
  staging: mt7621-dma: fix potentially dereferencing uninitialized 'tx_desc'
  staging: comedi: clarify/unify macros for NI macro-defined terminals
  drivers: staging: cedrus: find ctx before dereferencing it ctx
  staging: rtl8723bs: Fix the return value in case of error in 'rtw_wx_read32()'
  staging: comedi: ni_mio_common: scale ao INSN_CONFIG_GET_CMD_TIMING_CONSTRAINTS
  iio:st_magn: Fix enable device after trigger

Pull USB/PHY driver fixes from Greg KH:
 "Here are some small USB and PHY driver fixes for 4.20-rc5

  Nothing big at all, just the usual handful of USB fixes for reported
  issues, along with some gadget and PHY driver bug fixes.

  All of these have been in linux-next with no reported issues. Note,
  the USB gadget fixes were in linux-next on its own branch, not in
  mine, it just got merged into here yesterday and missed linux-next of
  today"

* tag 'usb-4.20-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: gadget: u_ether: fix unsafe list iteration
  USB: omap_udc: fix rejection of out transfers when DMA is used
  USB: omap_udc: fix USB gadget functionality on Palm Tungsten E
  USB: omap_udc: fix omap_udc_start() on 15xx machines
  USB: omap_udc: fix crashes on probe error and module removal
  USB: omap_udc: use devm_request_irq()
  usb: core: quirks: add RESET_RESUME quirk for Cherry G230 Stream series
  USB: usb-storage: Add new IDs to ums-realtek
  Revert "usb: dwc3: gadget: skip Set/Clear Halt when invalid"
  phy: qcom-qusb2: Fix HSTX_TRIM tuning with fused value for SDM845
  phy: qcom-qusb2: Use HSTX_TRIM fused value as is
  dt-bindings: phy-qcom-qmp: Fix several mistakes from prior commits
  phy: uniphier-pcie: Depend on HAS_IOMEM

Pull mtd fixes from Boris Brezillon:
 "NAND fix:
   - Fix BBT cache allocation done in nanddev_bbt_init()

  SPI NOR fixes:
   - Fix the erase type selection logic"

* tag 'mtd/fixes-for-4.20-rc5' of git://git.infradead.org/linux-mtd:
  mtd: nand: Fix memory allocation in nanddev_bbt_init()
  mtd: spi-nor: fix erase_type array to indicate current map conf

New versions of gcc reasonably warn about the odd pattern of

	strncpy(p, q, strlen(q));

which really doesn't make sense: the strncpy() ends up being just a slow
and odd way to write memcpy() in this case.

Apparently there was a patch for this floating around earlier, but it
got lost.
Acked-again-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull x86 fixes from Ingo Molnar:
 "Misc fixes:

   - MCE related boot crash fix on certain AMD systems

   - FPU exception handling fix

   - FPU handling race fix

   - revert+rewrite of the RSDP boot protocol extension, use boot_params
     instead

   - documentation fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/MCE/AMD: Fix the thresholding machinery initialization order
  x86/fpu: Use the correct exception table macro in the XSTATE_OP wrapper
  x86/fpu: Disable bottom halves while loading FPU registers
  x86/acpi, x86/boot: Take RSDP address from boot params if available
  x86/boot: Mostly revert commit ae7e1238 ("Add ACPI RSDP address to setup_header")
  x86/ptrace: Fix documentation for tracehook_report_syscall_entry()

Pull perf fixes from Ingo Molnar:
 "Misc fixes:

   - counter freezing related regression fix

   - uprobes race fix

   - Intel PMU unusual event combination fix

   - .. and diverse tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  uprobes: Fix handle_swbp() vs. unregister() + register() race once more
  perf/x86/intel: Disallow precise_ip on BTS events
  perf/x86/intel: Add generic branch tracing check to intel_pmu_has_bts()
  perf/x86/intel: Move branch tracing setup to the Intel-specific source file
  perf/x86/intel: Fix regression by default disabling perfmon v4 interrupt handling
  perf tools beauty ioctl: Support new ISO7816 commands
  tools uapi asm-generic: Synchronize ioctls.h
  tools arch x86: Update tools's copy of cpufeatures.h
  tools headers uapi: Synchronize i915_drm.h
  perf tools: Restore proper cwd on return from mnt namespace
  tools build feature: Check if get_current_dir_name() is available
  perf tools: Fix crash on synthesizing the unit

Pull EFI fix from Ingo Molnar:
 "An arm64 warning fix"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: Prevent GICv3 WARN() by mapping the memreserve table before first use

Pull objtool fixes from Ingo Molnar:
 "Two fixes for boundary conditions"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Fix segfault in .cold detection with -ffunction-sections
  objtool: Fix double-free in .cold detection error path

Pull vfs fixes from Al Viro:
 "Assorted fixes all over the place.

  The iov_iter one is this cycle regression (splice from UDP triggering
  WARN_ON()), the rest is older"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  afs: Use d_instantiate() rather than d_add() and don't d_drop()
  afs: Fix missing net error handling
  afs: Fix validation/callback interaction
  iov_iter: teach csum_and_copy_to_iter() to handle pipe-backed ones
  exportfs: do not read dentry after free
  exportfs: fix 'passing zero to ERR_PTR()' warning
  aio: fix failure to put the file pointer
  sysv: return 'err' instead of 0 in __sysv_write_inode

Pull more tracing fixes from Steven Rostedt:
 "Two more fixes:

   - Change idx variable in DO_TRACE macro to __idx to avoid name
     conflicts. A kvm event had "idx" as a parameter and it confused the
     macro.

   - Fix a race where interrupts would be traced when set_graph_function
     was set. The previous patch set increased a race window that
     tricked the function graph tracer to think it should trace
     interrupts when it really should not have.

     The bug has been there before, but was seldom hit. Only the last
     patch series made it more common"

* tag 'trace-v4.20-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/fgraph: Fix set_graph_function from showing interrupts
  tracepoint: Use __idx instead of idx in DO_TRACE macro to make it unique

Pull tracing fixes from Steven Rostedt:
 "While rewriting the function graph tracer, I discovered a design flaw
  that was introduced by a patch that tried to fix one bug, but by doing
  so created another bug.

  As both bugs corrupt the output (but they do not crash the kernel), I
  decided to fix the design such that it could have both bugs fixed. The
  original fix, fixed time reporting of the function graph tracer when
  doing a max_depth of one. This was code that can test how much the
  kernel interferes with userspace. But in doing so, it could corrupt
  the time keeping of the function profiler.

  The issue is that the curr_ret_stack variable was being used for two
  different meanings. One was to keep track of the stack pointer on the
  ret_stack (shadow stack used by the function graph tracer), and the
  other use case was the graph call depth. Although, the two may be
  closely related, where they got updated was the issue that lead to the
  two different bugs that required the two use cases to be updated
  differently.

  The big issue with this fix is that it requires changing each
  architecture. The good news is, I was able to remove a lot of code
  that was duplicated within the architectures and place it into a
  single location. Then I could make the fix in one place.

  I pushed this code into linux-next to let it settle over a week, and
  before doing so, I cross compiled all the affected architectures to
  make sure that they built fine.

  In the mean time, I also pulled in a patch that fixes the sched_switch
  previous tasks state output, that was not actually correct"

* tag 'trace-v4.20-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  sched, trace: Fix prev_state output in sched_switch tracepoint
  function_graph: Have profiler use curr_ret_stack and not depth
  function_graph: Reverse the order of pushing the ret_stack and the callback
  function_graph: Move return callback before update of curr_ret_stack
  function_graph: Use new curr_ret_depth to manage depth instead of curr_ret_stack
  function_graph: Make ftrace_push_return_trace() static
  sparc/function_graph: Simplify with function_graph_enter()
  sh/function_graph: Simplify with function_graph_enter()
  s390/function_graph: Simplify with function_graph_enter()
  riscv/function_graph: Simplify with function_graph_enter()
  powerpc/function_graph: Simplify with function_graph_enter()
  parisc: function_graph: Simplify with function_graph_enter()
  nds32: function_graph: Simplify with function_graph_enter()
  MIPS: function_graph: Simplify with function_graph_enter()
  microblaze: function_graph: Simplify with function_graph_enter()
  arm64: function_graph: Simplify with function_graph_enter()
  ARM: function_graph: Simplify with function_graph_enter()
  x86/function_graph: Simplify with function_graph_enter()
  function_graph: Create function_graph_enter() to consolidate architecture code

Pull drm fixes from Dave Airlie:
 "This weeks instalment of fixes. Looks fairly like business as usual
  and everything seems to rolling along. There was one MST fix applied
  and reverted in the misc tree, but otherwise nothing too strange in
  here.

  core:
   - incorrect master setting on error fix

  i915:
   - only GVT fixes this week:
      * one MOCS register load
      * rpm lock fix
      * use after free

  rcar-du:
   - regression fix for group start

  amdgpu:
   - DP MST fix
   - GPUVM fix for huge pages
   - RLC fix for vega20

  ast:
   - fix EDID reading stability
   - ioreg free fix

  meson:
   - sleep in irq fix
   - vblank fixes
   - array boundary fix"

* tag 'drm-fixes-2018-11-30' of git://anongit.freedesktop.org/drm/drm:
  drm/ast: fixed reading monitor EDID not stable issue
  drm/ast: Fix incorrect free on ioregs
  Revert "drm/dp_mst: Skip validating ports during destruction, just ref"
  drm/amdgpu: Add delay after enable RLC ucode
  drm/amdgpu: Avoid endless loop in GPUVM fragment processing
  drm/amdgpu: Cast to uint64_t before left shift
  drm/meson: add support for 1080p25 mode
  drm/meson: Fix OOB memory accesses in meson_viu_set_osd_lut()
  drm/meson: Enable fast_io in meson_dw_hdmi_regmap_config
  drm/meson: Fixes for drm_crtc_vblank_on/off support
  drm: set is_master to 0 upon drm_new_set_master() failure
  drm/dp_mst: Skip validating ports during destruction, just ref
  drm: rcar-du: Fix DU3 start/stop on M3-N
  drm/amd/dm: Understand why attaching path/tile properties are needed
  drm/amd/dm: Don't forget to attach MST encoders
  drm/i915/gvt: Avoid use-after-free iterating the gtt list
  drm/i915/gvt: ensure gpu is powered before do i915_gem_gtt_insert
  drm/i915/gvt: not to touch undefined MOCS registers

Pull pstore fix from Kees Cook:
 "Fix corrupted compression due to unlucky size choice with ECC"

* tag 'pstore-v4.20-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore/ram: Correctly calculate usable PRZ bytes

Pull rdma fixes from Jason Gunthorpe:
 "This is a bit later than usual for our first -rc but I'm not seeing
  anything worry-some in the RDMA tree right now. Quiet so far this -rc
  cycle, only a few internal driver related bugs and a small series
  fixing ODP bugs found by more advanced testing.

  A set of small driver and core code fixes:

   - Small series fixing longtime user triggerable bugs in the ODP
     processing inside mlx5 and core code

   - Various small driver malfunctions and crashes (use after, free,
     error unwind, implementation bugs)

   - A misfunction of the RDMA GID cache that can be triggered by the
     administrator"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  RDMA/mlx5: Initialize return variable in case pagefault was skipped
  IB/mlx5: Fix page fault handling for MW
  IB/umem: Set correct address to the invalidation function
  IB/mlx5: Skip non-ODP MR when handling a page fault
  RDMA/hns: Bugfix pbl configuration for rereg mr
  iser: set sector for ambiguous mr status errors
  RDMA/rdmavt: Fix rvt_create_ah function signature
  IB/mlx5: Avoid load failure due to unknown link width
  IB/mlx5: Fix XRC QP support after introducing extended atomic
  RDMA/bnxt_re: Avoid accessing the device structure after it is freed
  RDMA/bnxt_re: Fix system hang when registration with L2 driver fails
  RDMA/core: Add GIDs while changing MAC addr only for registered ndev
  RDMA/mlx5: Fix fence type for IB_WR_LOCAL_INV WR
  net/mlx5: Fix XRC SRQ umem valid bits

The tracefs file set_graph_function is used to only function graph functions
that are listed in that file (or all functions if the file is empty). The
way this is implemented is that the function graph tracer looks at every
function, and if the current depth is zero and the function matches
something in the file then it will trace that function. When other functions
are called, the depth will be greater than zero (because the original
function will be at depth zero), and all functions will be traced where the
depth is greater than zero.

The issue is that when a function is first entered, and the handler that
checks this logic is called, the depth is set to zero. If an interrupt comes
in and a function in the interrupt handler is traced, its depth will be
greater than zero and it will automatically be traced, even if the original
function was not. But because the logic only looks at depth it may trace
interrupts when it should not be.

The recent design change of the function graph tracer to fix other bugs
caused the depth to be zero while the function graph callback handler is
being called for a longer time, widening the race of this happening. This
bug was actually there for a longer time, but because the race window was so
small it seldom happened. The Fixes tag below is for the commit that widen
the race window, because that commit belongs to a series that will also help
fix the original bug.

Cc: stable@kernel.org
Fixes: 39eb456d ("function_graph: Use new curr_ret_depth to manage depth instead of curr_ret_stack")
Reported-by: Joe Lawrence <joe.lawrence@redhat.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

After enabling KVM event tracing, almost all of trace_kvm_exit()'s
printk shows

	"kvm_exit: IRQ: ..."

even if the actual exception_type is NOT IRQ.  More specifically,
trace_kvm_exit() is defined in virt/kvm/arm/trace.h by TRACE_EVENT.

This slight problem may have existed after commit e6753f23
("tracepoint: Make rcuidle tracepoint callers use SRCU"). There are
two variables in trace_kvm_exit() and __DO_TRACE() which have the
same name, *idx*. Thus the actual value of *idx* will be overwritten
when tracing. Fix it by adding a simple prefix.

Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Wang Haibin <wanghaibin.wang@huawei.com>
Cc: linux-trace-devel@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: e6753f23 ("tracepoint: Make rcuidle tracepoint callers use SRCU")
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Use d_instantiate() rather than d_add() and don't d_drop() in
afs_vnode_new_inode().  The dentry shouldn't be removed as it's not
changing its name.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

kAFS can be given certain network errors (EADDRNOTAVAIL, EHOSTDOWN and
ERFKILL) that it doesn't handle in its server/address rotation algorithms.
They cause the probing and rotation to abort immediately rather than
rotating.

Fix this by:

 (1) Abstracting out the error prioritisation from the VL and FS rotation
     algorithms into a common function and expand usage into the server
     probing code.

     When multiple errors are available, this code selects the one we'd
     prefer to return.

 (2) Add handling for EADDRNOTAVAIL, EHOSTDOWN and ERFKILL.

Fixes: 0fafdc9f ("afs: Fix file locking")
Fixes: 0338747d8454 ("afs: Probe multiple fileservers simultaneously")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

When afs_validate() is called to validate a vnode (inode), there are two
unhandled cases in the fastpath at the top of the function:

 (1) If the vnode is promised (AFS_VNODE_CB_PROMISED is set), the break
     counters match and the data has expired, then there's an implicit case
     in which the vnode needs revalidating.

     This has no consequences since the default "valid = false" set at the
     top of the function happens to do the right thing.

 (2) If the vnode is not promised and it hasn't been deleted
     (AFS_VNODE_DELETED is not set) then there's a default case we're not
     handling in which the vnode is invalid.  If the vnode is invalid, we
     need to bring cb_s_break and cb_v_break up to date before we refetch
     the status.

     As a consequence, once the server loses track of the client
     (ie. sufficient time has passed since we last sent it an operation),
     it will send us a CB.InitCallBackState* operation when we next try to
     talk to it.  This calls afs_init_callback_state() which increments
     afs_server::cb_s_break, but this then doesn't propagate to the
     afs_vnode record.

     The result being that every afs_validate() call thereafter sends a
     status fetch operation to the server.

Clarify and fix this by:

 (A) Setting valid in all the branches rather than initialising it at the
     top so that the compiler catches where we've missed.

 (B) Restructuring the logic in the 'promised' branch so that we set valid
     to false if the callback is due to expire (or has expired) and so that
     the final case is that the vnode is still valid.

 (C) Adding an else-statement that ups cb_s_break and cb_v_break if the
     promised and deleted cases don't match.

Fixes: c435ee34 ("afs: Overhaul the callback handling")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Pull ACPI fix from Rafael Wysocki:
 "Fix a recent regression in ACPICA releted to the Generic Serial Bus
  protocol handling and causing it to read or write too little or too
  much data in some cases, so incorrect data may be written to hardware
  as a result (Hans de Goede)"

* tag 'acpi-4.20-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPICA: Fix handling of buffer-size in acpi_ex_write_data_to_field()

Pull power management fixes from Rafael Wysocki:
 "These fix two issues in the operating performance points (OPP)
  framework.

  Specifics:

   - Fix the handling of the "operating-points-v2" property to avoid
     failures if multiple phandles are present in it which is legitimate
     (Viresh Kumar).

   - Drop the unnecessary static initialization of the .owner field in
     the ti_opp_supply_driver structure (YueHaibing)"

* tag 'pm-4.20-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  OPP: Fix parsing of multiple phandles in "operating-points-v2" property
  opp: ti-opp-supply: Fix platform_no_drv_owner.cocci warnings

Pagefaults occurred in non-ODP MR are completely valid events, so
initialize return variable to 0.

Fixes: 4d5422a3 ("IB/mlx5: Skip non-ODP MR when handling a page fault")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

The actual number of bytes stored in a PRZ is smaller than the
bytes requested by platform data, since there is a header on each
PRZ. Additionally, if ECC is enabled, there are trailing bytes used
as well. Normally this mismatch doesn't matter since PRZs are circular
buffers and the leading "overflow" bytes are just thrown away. However, in
the case of a compressed record, this rather badly corrupts the results.

This corruption was visible with "ramoops.mem_size=204800 ramoops.ecc=1".
Any stored crashes would not be uncompressable (producing a pstorefs
"dmesg-*.enc.z" file), and triggering errors at boot:

  [    2.790759] pstore: crypto_comp_decompress failed, ret = -22!

Backporting this depends on commit 70ad35db ("pstore: Convert console
write to use ->write_buf")
Reported-by: Joel Fernandes <joel@joelfernandes.org>
Fixes: b0aad7a9 ("pstore: Add compression support to pstore")
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>