Loading the pmd without holding the pmd_lock exposes us to races with
concurrent updaters of the page tables but, worse still, it also allows
the compiler to cache the pmd value in a register and reuse it later on,
even if we've performed a READ_ONCE in between and seen a more recent
value.

In the case of page_vma_mapped_walk, this leads to the following crash
when the pmd loaded for the initial pmd_trans_huge check is all zeroes
and a subsequent valid table entry is loaded by check_pmd.  We then
proceed into map_pte, but the compiler re-uses the zero entry inside
pte_offset_map, resulting in a junk pointer being installed in
pvmw->pte:

  PC is at check_pte+0x20/0x170
  LR is at page_vma_mapped_walk+0x2e0/0x540
  [...]
  Process doio (pid: 2463, stack limit = 0xffff00000f2e8000)
  Call trace:
    check_pte+0x20/0x170
    page_vma_mapped_walk+0x2e0/0x540
    page_mkclean_one+0xac/0x278
    rmap_walk_file+0xf0/0x238
    rmap_walk+0x64/0xa0
    page_mkclean+0x90/0xa8
    clear_page_dirty_for_io+0x84/0x2a8
    mpage_submit_page+0x34/0x98
    mpage_process_page_bufs+0x164/0x170
    mpage_prepare_extent_to_map+0x134/0x2b8
    ext4_writepages+0x484/0xe30
    do_writepages+0x44/0xe8
    __filemap_fdatawrite_range+0xbc/0x110
    file_write_and_wait_range+0x48/0xd8
    ext4_sync_file+0x80/0x4b8
    vfs_fsync_range+0x64/0xc0
    SyS_msync+0x194/0x1e8

This patch fixes the problem by ensuring that READ_ONCE is used before
the initial checks on the pmd, and this value is subsequently used when
checking whether or not the pmd is present.  pmd_check is removed and
the pmd_present check is inlined directly.

Link: http://lkml.kernel.org/r/1507222630-5839-1-git-send-email-will.deacon@arm.com
Fixes: f27176cf ("mm: convert page_mkclean_one() to use page_vma_mapped_walk()")
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Tested-by: NYury Norov <ynorov@caviumnetworks.com>
Tested-by: NRichard Ruigrok <rruigrok@codeaurora.org>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Kmemleak considers any pointers on task stacks as references.  This
patch clears newly allocated and reused vmap stacks.

Link: http://lkml.kernel.org/r/150728990124.744199.8403409836394318684.stgit@buzzSigned-off-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

inode->i_private is assigned by a Node pointer only after registering a
new binary format, so it could be NULL if inode was created by
bm_fill_super() (or iput() was called by the error path in
bm_register_write()), and this could result in NULL pointer dereference
when evicting such an inode.  e.g.  mount binfmt_misc filesystem then
umount it immediately:

  mount -t binfmt_misc binfmt_misc /proc/sys/fs/binfmt_misc
  umount /proc/sys/fs/binfmt_misc

will result in

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000013
  IP: bm_evict_inode+0x16/0x40 [binfmt_misc]
  ...
  Call Trace:
   evict+0xd3/0x1a0
   iput+0x17d/0x1d0
   dentry_unlink_inode+0xb9/0xf0
   __dentry_kill+0xc7/0x170
   shrink_dentry_list+0x122/0x280
   shrink_dcache_parent+0x39/0x90
   do_one_tree+0x12/0x40
   shrink_dcache_for_umount+0x2d/0x90
   generic_shutdown_super+0x1f/0x120
   kill_litter_super+0x29/0x40
   deactivate_locked_super+0x43/0x70
   deactivate_super+0x45/0x60
   cleanup_mnt+0x3f/0x70
   __cleanup_mnt+0x12/0x20
   task_work_run+0x86/0xa0
   exit_to_usermode_loop+0x6d/0x99
   syscall_return_slowpath+0xba/0xf0
   entry_SYSCALL_64_fastpath+0xa3/0xa

Fix it by making sure Node (e) is not NULL.

Link: http://lkml.kernel.org/r/20171010100642.31786-1-eguan@redhat.com
Fixes: 83f91827 ("exec: binfmt_misc: shift filp_close(interp_file) from kill_node() to bm_evict_inode()")
Signed-off-by: NEryu Guan <eguan@redhat.com>
Acked-by: NOleg Nesterov <oleg@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When using FAT on a block device which supports rw_page, we can hit
BUG_ON(!PageLocked(page)) in try_to_free_buffers().  This is because we
call clean_buffers() after unlocking the page we've written.  Introduce
a new clean_page_buffers() which cleans all buffers associated with a
page and call it from within bdev_write_page().

[akpm@linux-foundation.org: s/PAGE_SIZE/~0U/ per Linus and Matthew]
Link: http://lkml.kernel.org/r/20171006211541.GA7409@bombadil.infradead.orgSigned-off-by: NMatthew Wilcox <mawilcox@microsoft.com>
Reported-by: NToshi Kani <toshi.kani@hpe.com>
Reported-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Tested-by: NToshi Kani <toshi.kani@hpe.com>
Acked-by: NJohannes Thumshirn <jthumshirn@suse.de>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add kernel-doc notation for some macros.  Correct kernel-doc comments &
typos for a few macros.

Link: http://lkml.kernel.org/r/76fa1403-1511-be4c-e9c4-456b43edfad3@infradead.orgSigned-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We have seen NULL-pointer dereference crashes in tty->disc_data when the
N_TTY fallback driver failed to open during hangup.  The immediate cause
of this open to fail has been addressed in the preceding patch to
vmalloc(), but this code could be more robust.

As Alan pointed out in commit 8a8dabf2 ("tty: handle the case where
we cannot restore a line discipline"), the N_TTY driver, historically
the safe fallback that could never fail, can indeed fail, but the
surrounding code is not prepared to handle this.  To avoid crashes he
added a new N_NULL driver to take N_TTY's place as the last resort.

Hook that fallback up to the hangup path.  Update tty_ldisc_reinit() to
reflect the reality that n_tty_open can indeed fail.

Link: http://lkml.kernel.org/r/20171004185959.GC2136@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Alan Cox <alan@llwyncelyn.cymru>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commits 5d17a73a ("vmalloc: back off when the current
task is killed") and 171012f5 ("mm: don't warn when vmalloc() fails
due to a fatal signal").

Commit 5d17a73a ("vmalloc: back off when the current task is
killed") made all vmalloc allocations from a signal-killed task fail.
We have seen crashes in the tty driver from this, where a killed task
exiting tries to switch back to N_TTY, fails n_tty_open because of the
vmalloc failing, and later crashes when dereferencing tty->disc_data.

Arguably, relying on a vmalloc() call to succeed in order to properly
exit a task is not the most robust way of doing things.  There will be a
follow-up patch to the tty code to fall back to the N_NULL ldisc.

But the justification to make that vmalloc() call fail like this isn't
convincing, either.  The patch mentions an OOM victim exhausting the
memory reserves and thus deadlocking the machine.  But the OOM killer is
only one, improbable source of fatal signals.  It doesn't make sense to
fail allocations preemptively with plenty of memory in most cases.

The patch doesn't mention real-life instances where vmalloc sites would
exhaust memory, which makes it sound more like a theoretical issue to
begin with.  But just in case, the OOM access to memory reserves has
been restricted on the allocator side in cd04ae1e ("mm, oom: do not
rely on TIF_MEMDIE for memory reserves access"), which should take care
of any theoretical concerns on that front.

Revert this patch, and the follow-up that suppresses the allocation
warnings when we fail the allocations due to a signal.

Link: http://lkml.kernel.org/r/20171004185906.GB2136@cmpxchg.org
Fixes:  171012f5 ("mm: don't warn when vmalloc() fails due to a fatal signal")
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Alan Cox <alan@llwyncelyn.cymru>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

cma_alloc() unconditionally prints an INFO message when the CMA
allocation fails.  Make this message conditional on the non-presence of
__GFP_NOWARN in gfp_mask.

This patch aims at removing INFO messages that are displayed when the
VC4 driver tries to allocate buffer objects.  From the driver
perspective an allocation failure is acceptable, and the driver can
possibly do something to make following allocation succeed (like
flushing the VC4 internal cache).

Link: http://lkml.kernel.org/r/20171004125447.15195-1-boris.brezillon@free-electrons.comSigned-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: NLaura Abbott <labbott@redhat.com>
Cc: Jaewon Kim <jaewon31.kim@samsung.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Eric Anholt <eric@anholt.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

gcc on aarch64 may emit synbols of type 'n' if the kernel is built with
'-frecord-gcc-switches'.  In most cases, those symbols are reported with
nm as

	000000000000000e n $d

and with objdump as

	0000000000000000 l    d  .GCC.command.line	0000000000000000 .GCC.command.line
	000000000000000e l       .GCC.command.line	0000000000000000 $d

Those symbols are detected in is_arm_mapping_symbol() and ignored.
However, if "--prefix-symbols=<prefix>" is configured as well, the
situation is different.  For example, in efi/libstub, arm64 images are
built with

	'--prefix-alloc-sections=.init --prefix-symbols=__efistub_'.

In combination with '-frecord-gcc-switches', the symbols are now reported
by nm as:

	000000000000000e n __efistub_$d
and by objdump as:
	0000000000000000 l    d  .GCC.command.line	0000000000000000 .GCC.command.line
	000000000000000e l       .GCC.command.line	0000000000000000 __efistub_$d

Those symbols are no longer ignored and included in the base address
calculation.  This results in a base address of 000000000000000e, which
in turn causes kallsyms to abort with

    kallsyms failure:
	relative symbol value 0xffffff900800a000 out of range in relative mode

The problem is seen in little endian arm64 builds with CONFIG_EFI
enabled and with '-frecord-gcc-switches' set in KCFLAGS.

Explicitly ignore symbols of type 'n' since those are clearly debug
symbols.

Link: http://lkml.kernel.org/r/1507136063-3139-1-git-send-email-linux@roeck-us.netSigned-off-by: NGuenter Roeck <linux@roeck-us.net>
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I was stress testing some backports and with high load, after some time,
the latest version of the selftest showed some false positive in
connection with the uffdio_copy_retry.  This seems to fix it while still
exercising -EEXIST in the background transfer once in a while.

The fork child will quit after the last UFFDIO_COPY is run, so a
repeated UFFDIO_COPY may not return -EEXIST.  This change restricts the
-EEXIST stress to the background transfer where the memory can't go away
from under it.

Also updated uffdio_zeropage, so the interface is consistent.

Link: http://lkml.kernel.org/r/20171004171541.1495-2-aarcange@redhat.comSigned-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When I execute numactl -H (which reads /sys/devices/system/node/nodeX/cpumap
and displays cpumask_of_node for each node), I get different result
on X86 and arm64.  For each numa node, the former only displayed online
CPUs, and the latter displayed all possible CPUs.  Unfortunately, both
Linux documentation and numactl manual have not described it clear.

I sent a mail to ask for help, and Michal Hocko replied that he
preferred to print online cpus because it doesn't really make much sense
to bind anything on offline nodes.

Will said:
 "I suspect the vast majority (if not all) code that reads this file was
  developed for x86, so having the same behaviour for arm64 sounds like
  something we should do ASAP before people try to special case with
  things like #ifdef __aarch64__. I'd rather have this in 4.14 if
  possible."

Link: http://lkml.kernel.org/r/1506678805-15392-2-git-send-email-thunder.leizhen@huawei.comSigned-off-by: NZhen Lei <thunder.leizhen@huawei.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tianhong Ding <dingtianhong@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Libin <huawei.libin@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A non present pmd entry can appear after pmd_lock is taken in
page_vma_mapped_walk(), even if THP migration is not enabled.  The
WARN_ONCE is unnecessary.

Link: http://lkml.kernel.org/r/20171003142606.12324-1-zi.yan@sent.com
Fixes: 616b8371 ("mm: thp: enable thp migration in generic path")
Signed-off-by: NZi Yan <zi.yan@cs.rutgers.edu>
Reported-by: NAbdul Haleem <abdhalee@linux.vnet.ibm.com>
Tested-by: NAbdul Haleem <abdhalee@linux.vnet.ibm.com>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 3a321d2a ("mm: change the call sites of numa statistics
items") separated NUMA counters from zone counters, but the
NUMA_INTERLEAVE_HIT call site wasn't updated to use the new interface.
So alloc_page_interleave() actually increments NR_ZONE_INACTIVE_FILE
instead of NUMA_INTERLEAVE_HIT.

Fix this by using __inc_numa_state() interface to increment
NUMA_INTERLEAVE_HIT.

Link: http://lkml.kernel.org/r/20171003191003.8573-1-aryabinin@virtuozzo.com
Fixes: 3a321d2a ("mm: change the call sites of numa statistics items")
Signed-off-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Cc: Kemi Wang <kemi.wang@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The pci-rcar driver is enabled for compile tests, and this has shown that
the driver cannot build without CONFIG_OF, following the inclusion of
commit f8f2fe73 ("PCI: rcar: Use new OF interrupt mapping when possible"):

  drivers/pci/host/pcie-rcar.c: In function 'pci_dma_range_parser_init':
  drivers/pci/host/pcie-rcar.c:1039:2: error: implicit declaration of function 'of_n_addr_cells' [-Werror=implicit-function-declaration]
    parser->pna = of_n_addr_cells(node);
    ^

As pointed out by Ben Dooks and Geert Uytterhoeven, this is actually
supposed to build fine, which we can achieve if we make the declaration
of of_irq_parse_and_map_pci conditional on CONFIG_OF and provide an
empty inline function otherwise, as we do for a lot of other of
interfaces.

This lets us build the rcar_pci driver again without CONFIG_OF for build
testing.  All platforms using this driver select OF, so this doesn't
change anything for the users.

[akpm@linux-foundation.org: be consistent with surrounding code]
Link: http://lkml.kernel.org/r/20170911200805.3363318-1-arnd@arndb.de
Fixes: c25da477 ("PCI: rcar: Add Renesas R-Car PCIe driver")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NFrank Rowand <frank.rowand@sony.com>
Acked-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Magnus Damm <damm@opensource.se>
Cc: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/madvise.c has a brief description about all MADV_ flags.  Add a
description for the newly added MADV_WIPEONFORK and MADV_KEEPONFORK.

Although man page has the similar information, but it'd better to keep
the consistent with other flags.

Link: http://lkml.kernel.org/r/1506117328-88228-1-git-send-email-yang.s@alibaba-inc.comSigned-off-by: NYang Shi <yang.s@alibaba-inc.com>
Reviewed-by: NRik van Riel <riel@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Expand the "Runtime testing" menu by including more entries inside it
instead of after it.  This is just Kconfig symbol movement.

This causes the (arch-independent) Runtime tests to be presented
(listed) all in one place instead of in multiple places.

Link: http://lkml.kernel.org/r/c194e5c4-2042-bf94-a2d8-7aa13756e257@infradead.orgSigned-off-by: NRandy Dunlap <rdunlap@infradead.org>
Acked-by: NKees Cook <keescook@chromium.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Index was incremented before last use and thus the second array could
dereference to an invalid address (not mentioning the fact that it did
not properly clear the entry we intended to clear).

Link: http://lkml.kernel.org/r/1506973525-16491-1-git-send-email-jglisse@redhat.com
Fixes: 8315ada7 ("mm/migrate: allow migrate_vma() to alloc new page on empty entry")
Signed-off-by: NMark Hairgrove <mhairgrove@nvidia.com>
Signed-off-by: NJérôme Glisse <jglisse@redhat.com>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull IOMMU fixes from Joerg Roedel:

 - keep an important data structure in the Exynos driver around after
   kernel-init to fix a kernel-oops

 - keep SWIOTLB enabled when SME is active in the AMD IOMMU driver

 - add a missing IOTLB sync to the AMD IOMMU driver

* tag 'iommu-fixes-v4.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/amd: Finish TLB flush in amd_iommu_unmap()
  iommu/exynos: Remove initconst attribute to avoid potential kernel oops
  iommu/amd: Do not disable SWIOTLB if SME is active

Pull DeviceTree fixes from Rob Herring:

 - Fix memory leak in error case of of_console_check

 - Increase number of reserved memory regions to 32. 16 was not enough
   on some Power systems.

 - Fix OF node refcounting for of_fwnode_graph_get_port_parent

* tag 'devicetree-fixes-for-4.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  device property: preserve usecount for node passed to of_fwnode_graph_get_port_parent()
  drivers: of: increase MAX_RESERVED_REGIONS to 32
  of: do not leak console options

Pull powerpc fixes from Michael Ellerman:
 "A fix for a bad bug (written by me) in our livepatch handler. Removal
  of an over-zealous lockdep_assert_cpus_held() in our topology code. A
  fix to the recently added emulation of cntlz[wd]. And three small
  fixes to the recently added IMC PMU driver.

  Thanks to: Anju T Sudhakar, Balbir Singh, Kamalesh Babulal, Naveen N.
  Rao, Sandipan Das, Santosh Sivaraj, Thiago Jung Bauermann"

* tag 'powerpc-4.14-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/perf: Fix IMC initialization crash
  powerpc/perf: Add ___GFP_NOWARN flag to alloc_pages_node()
  powerpc/perf: Fix for core/nest imc call trace on cpuhotplug
  powerpc: Don't call lockdep_assert_cpus_held() from arch_update_cpu_topology()
  powerpc/lib/sstep: Fix count leading zeros instructions
  powerpc/livepatch: Fix livepatch stack access

Pull xen fixlet from Juergen Gross:
 "A minor fix correcting the cpu hotplug name for Xen guests"

* tag 'for-linus-4.14c-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/vcpu: Use a unified name about cpu hotplug state for pv and pvhvm

The function only sends the flush command to the IOMMU(s),
but does not wait for its completion when it returns. Fix
that.

Fixes: 601367d7 ('x86/amd-iommu: Remove iommu_flush_domain function')
Cc: stable@vger.kernel.org # >= 2.6.33
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Panic observed with latest firmware, and upstream kernel:

 NIP init_imc_pmu+0x8c/0xcf0
 LR  init_imc_pmu+0x2f8/0xcf0
 Call Trace:
   init_imc_pmu+0x2c8/0xcf0 (unreliable)
   opal_imc_counters_probe+0x300/0x400
   platform_drv_probe+0x64/0x110
   driver_probe_device+0x3d8/0x580
   __driver_attach+0x14c/0x1a0
   bus_for_each_dev+0x8c/0xf0
   driver_attach+0x34/0x50
   bus_add_driver+0x298/0x350
   driver_register+0x9c/0x180
   __platform_driver_register+0x5c/0x70
   opal_imc_driver_init+0x2c/0x40
   do_one_initcall+0x64/0x1d0
   kernel_init_freeable+0x280/0x374
   kernel_init+0x24/0x160
   ret_from_kernel_thread+0x5c/0x74

While registering nest imc at init, cpu-hotplug callback
nest_pmu_cpumask_init() makes an OPAL call to stop the engine. And if
the OPAL call fails, imc_common_cpuhp_mem_free() is invoked to cleanup
memory and cpuhotplug setup.

But when cleaning up the attribute group, we are dereferencing the
attribute element array without checking whether the backing element
is not NULL. This causes the kernel panic.

Add a check for the backing element prior to dereferencing the
attribute element, to handle the failing case gracefully.
Signed-off-by: NAnju T Sudhakar <anju@linux.vnet.ibm.com>
Reported-by: NPridhiviraj Paidipeddi <ppaidipe@linux.vnet.ibm.com>
[mpe: Trim change log]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Pull device properties framework fixes from Rafael Wysocki:
 "These fix an issue related to device removal introduced during the 4.9
  cycle and fix up new functionality added recently.

  Specifics:

   - Fix a device properties management issue, introduced during the 4.9
     cycle, that causes device properties associated with a parent
     device to go away on a removal of its child in some cases (Jarkko
     Nikula).

   - Fix inconsistencies in error codes returned by a new function
     helper in the device properties framework depending on the
     underlying low-level firmware interface, DT or ACPI, by making the
     meaning of error codes returned in the ACPI case agree with the
     meaning of DT error codes in analogous situations (Sakari Ailus)"

* tag 'devprop-4.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: properties: Fix __acpi_node_get_property_reference() return codes
  ACPI: properties: Align return codes of __acpi_node_get_property_reference()
  device property: Track owner device of device property

Pull xfs fixes from Darrick Wong:

 - Fix a stale kernel memory exposure when logging inodes.

 - Fix some build problems with CONFIG_XFS_RT=n

 - Don't change inode mode if the acl write fails, leaving the file
   totally inaccessible.

 - Fix a dangling pointer problem when removing an attr fork under
   memory pressure.

 - Don't crash while trying to invalidate a null buffer associated with
   a corrupt metadata pointer.

* tag 'xfs-4.14-fixes-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: handle error if xfs_btree_get_bufs fails
  xfs: reinit btree pointer on attr tree inactivation walk
  xfs: Fix bool initialization/comparison
  xfs: don't change inode mode if ACL update fails
  xfs: move more RT specific code under CONFIG_XFS_RT
  xfs: Don't log uninitialised fields in inode structures

If faddr2line is given a function name which is the last one listed by
"nm -n", it will fail because it never finds the next symbol.

So teach the awk script to catch that possibility, and use 'size' to
provide the end point of the last function.
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull quota fix from Jan Kara:
 "A fix for a regression in handling of quota grace times and warnings"

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  quota: Generate warnings for DQUOT_SPACE_NOFAIL allocations

Pull kvm fixes from Paolo Bonzini:
 "Another latent bug related to PCID, an out-of-bounds access, and a
  submaintainer change being finally made official"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  MAINTAINERS: Add Paul Mackerras as maintainer for KVM/powerpc
  KVM: nVMX: fix guest CR4 loading when emulating L2 to L1 exit
  KVM: MMU: always terminate page walks at level 1
  KVM: nVMX: update last_nonleaf_level when initializing nested EPT

Using CONFIG_OF_DYNAMIC=y uncovered an imbalance in the usecount of the
node being passed to of_fwnode_graph_get_port_parent(). Preserve the
usecount by using of_get_parent() instead of of_get_next_parent() which
don't decrement the usecount of the node passed to it.

Fixes: 3b27d00e ("device property: Move fwnode graph ops to firmware specific locations")
Signed-off-by: NNiklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NRob Herring <robh@kernel.org>

There are two types of memory reservations firmware can ask the kernel
to make in the device tree: static and dynamic.
See Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt

If you have greater than 16 entries in /reserved-memory (as we do on
POWER9 systems) you would get this scary looking error message:
 [    0.000000] OF: reserved mem: not enough space all defined regions.

This is harmless if all your reservations are static (which with OPAL on
POWER9, they are).

It is not harmless if you have any dynamic reservations after the 16th.

In the first pass over the fdt to find reservations, the child nodes of
/reserved-memory are added to a static array in of_reserved_mem.c so that
memory can be reserved in a 2nd pass. The array has 16 entries. This is why,
on my dual socket POWER9 system, I get that error 4 times with 20 static
reservations.

We don't have a problem on ppc though, as in arch/powerpc/kernel/prom.c
we look at the new style /reserved-ranges property to do reservations,
and this logic was introduced in 0962e800 (well before any powernv
system shipped).

A Google search shows up no occurances of that exact error message, so we're
probably safe in that no machine that people use has memory not being reserved
when it should be.

The simple fix is to bump the length of the array to 32 which "should be
enough for everyone(TM)". The simple fix of not recording static allocations
in the array would cause problems for devices with "memory-region" properties.
A more future-proof fix is likely possible, although more invasive and this
simple fix is perfectly suitable in the meantime while a more future-proof
fix is developed.
Signed-off-by: NStewart Smith <stewart@linux.vnet.ibm.com>
Tested-by: NMauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
Signed-off-by: NRob Herring <robh@kernel.org>

Do not strdup() console options. It seems that the only reason for
it to be strdup()-ed was a compilation warning: printk, UART and
console drivers, for some reason, expect char pointer instead of
const char pointer. So we can just pass `of_stdout_options', but
need to cast it to char pointer. A better fix would be to change
printk, console drivers and UART to accept const char `options';
but that will take time - there are lots of drivers to update.

The patch also fixes a possible memory leak: add_preferred_console()
can fail, but we don't kfree() options.
Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: NPetr Mladek <pmladek@suse.com>
Signed-off-by: NRob Herring <robh@kernel.org>

Pull crypto fixes from Herbert Xu:

 - fix crashes in skcipher/shash from zero-length input.

 - fix softirq GFP_KERNEL allocation in shash_setkey_unaligned.

 - error path bug fix in xts create function.

 - fix compiler warning regressions in axis and stm32

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: shash - Fix zero-length shash ahash digest crash
  crypto: skcipher - Fix crash on zero-length input
  crypto: shash - Fix a sleep-in-atomic bug in shash_setkey_unaligned
  crypto: xts - Fix an error handling path in 'create()'
  crypto: stm32 - Try to fix hash padding
  crypto: axis - hide an unused variable

Pull livepatching fix from Jiri Kosina:

 - bugfix for handling of coming modules (incorrect handling of failure)
   from Joe Lawrence

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
  livepatch: unpatch all klp_objects if klp_module_coming fails

Pull HID fixes from Jiri Kosina:

 - fix for potential out-of-bounds memory access (found by fuzzing,
   likely requires specially crafted device to trigger) by Jaejoong Kim

 - two new device IDs for elecom driver from Alex Manoussakis

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: hid-elecom: extend to fix descriptor for HUGE trackball
  HID: usbhid: fix out-of-bounds bug

Pull sound fixes from Takashi Iwai:
 "It's been a busy week for defending the attacks from fuzzer people.

  This contains various USB-audio driver fixes and sequencer core fixes
  spotted by syzkaller and other fuzzer, as well as one quirk for a
  Plantronics USB audio device"

* tag 'sound-4.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: caiaq: Fix stray URB at probe error path
  ALSA: seq: Fix use-after-free at creating a port
  ALSA: usb-audio: Kill stray URB at exiting
  ALSA: line6: Fix leftover URB at error-path during probe
  ALSA: line6: Fix NULL dereference at podhd_disconnect()
  ALSA: line6: Fix missing initialization before error path
  ALSA: seq: Fix copy_from_user() call inside lock
  ALSA: usb-audio: Add sample rate quirk for Plantronics P610

Merge waitid() fix from Kees Cook.

I'd have hoped that the unsafe_{get|put}_user() naming would have
avoided these kinds of stupid bugs, but no such luck.

* waitid-fix:
  waitid(): Add missing access_ok() checks

Stack trace output during a stress test:
 [    4.310049] Freeing initrd memory: 22592K
[    4.310646] rtas_flash: no firmware flash support
[    4.313341] cpuhp/64: page allocation failure: order:0, mode:0x14480c0(GFP_KERNEL|__GFP_ZERO|__GFP_THISNODE), nodemask=(null)
[    4.313465] cpuhp/64 cpuset=/ mems_allowed=0
[    4.313521] CPU: 64 PID: 392 Comm: cpuhp/64 Not tainted 4.11.0-39.el7a.ppc64le #1
[    4.313588] Call Trace:
[    4.313622] [c000000f1fb1b8e0] [c000000000c09388] dump_stack+0xb0/0xf0 (unreliable)
[    4.313694] [c000000f1fb1b920] [c00000000030ef6c] warn_alloc+0x12c/0x1c0
[    4.313753] [c000000f1fb1b9c0] [c00000000030ff68] __alloc_pages_nodemask+0xea8/0x1000
[    4.313823] [c000000f1fb1bbb0] [c000000000113a8c] core_imc_mem_init+0xbc/0x1c0
[    4.313892] [c000000f1fb1bc00] [c000000000113cdc] ppc_core_imc_cpu_online+0x14c/0x170
[    4.313962] [c000000f1fb1bc90] [c000000000125758] cpuhp_invoke_callback+0x198/0x5d0
[    4.314031] [c000000f1fb1bd00] [c00000000012782c] cpuhp_thread_fun+0x8c/0x3d0
[    4.314101] [c000000f1fb1bd60] [c0000000001678d0] smpboot_thread_fn+0x290/0x2a0
[    4.314169] [c000000f1fb1bdc0] [c00000000015ee78] kthread+0x168/0x1b0
[    4.314229] [c000000f1fb1be30] [c00000000000b368] ret_from_kernel_thread+0x5c/0x74
[    4.314313] Mem-Info:
[    4.314356] active_anon:0 inactive_anon:0 isolated_anon:0

core_imc_mem_init() at system boot use alloc_pages_node() to get memory
and alloc_pages_node() throws this stack dump when tried to allocate
memory from a node which has no memory behind it. Add a ___GFP_NOWARN
flag in allocation request as a fix.
Signed-off-by: NAnju T Sudhakar <anju@linux.vnet.ibm.com>
Reported-by: NMichael Ellerman <mpe@ellerman.id.au>
Reported-by: NVenkat R.B <venkatb3@in.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Nest/core pmu units are enabled only when it is used. A reference count is
maintained for the events which uses the nest/core pmu units. Currently in
*_imc_counters_release function a WARN() is used for notification of any
underflow of ref count.

The case where event ref count hit a negative value is, when perf session is
started, followed by offlining of all cpus in a given core.
i.e. in cpuhotplug offline path ppc_core_imc_cpu_offline() function set the
ref->count to zero, if the current cpu which is about to offline is the last
cpu in a given core and make an OPAL call to disable the engine in that core.
And on perf session termination, perf->destroy (core_imc_counters_release) will
first decrement the ref->count for this core and based on the ref->count value
an opal call is made to disable the core-imc engine.
Now, since cpuhotplug path already clears the ref->count for core and disabled
the engine, perf->destroy() decrementing again at event termination make it
negative which in turn fires the WARN_ON. The same happens for nest units.

Add a check to see if the reference count is alreday zero, before decrementing
the count, so that the ref count will not hit a negative value.
Signed-off-by: NAnju T Sudhakar <anju@linux.vnet.ibm.com>
Reviewed-by: NSantosh Sivaraj <santosh@fossix.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Paul is handling almost all of the powerpc related KVM patches nowadays,
so he should be mentioned in the MAINTAINERS file accordingly.
Signed-off-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

When KVM emulates an exit from L2 to L1, it loads L1 CR4 into the
guest CR4. Before this CR4 loading, the guest CR4 refers to L2
CR4. Because these two CR4's are in different levels of guest, we
should vmx_set_cr4() rather than kvm_set_cr4() here. The latter, which
is used to handle guest writes to its CR4, checks the guest change to
CR4 and may fail if the change is invalid.

The failure may cause trouble. Consider we start
  a L1 guest with non-zero L1 PCID in use,
     (i.e. L1 CR4.PCIDE == 1 && L1 CR3.PCID != 0)
and
  a L2 guest with L2 PCID disabled,
     (i.e. L2 CR4.PCIDE == 0)
and following events may happen:

1. If kvm_set_cr4() is used in load_vmcs12_host_state() to load L1 CR4
   into guest CR4 (in VMCS01) for L2 to L1 exit, it will fail because
   of PCID check. As a result, the guest CR4 recorded in L0 KVM (i.e.
   vcpu->arch.cr4) is left to the value of L2 CR4.

2. Later, if L1 attempts to change its CR4, e.g., clearing VMXE bit,
   kvm_set_cr4() in L0 KVM will think L1 also wants to enable PCID,
   because the wrong L2 CR4 is used by L0 KVM as L1 CR4. As L1
   CR3.PCID != 0, L0 KVM will inject GP to L1 guest.

Fixes: 4704d0be ("KVM: nVMX: Exiting from L2 to L1")
Cc: qemu-stable@nongnu.org
Signed-off-by: NHaozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>