linux-stable.git/mm, branch v5.4.16

mm/page-writeback.c: avoid potential division by zero in wb_min_max_ratio()

2020-01-23T07:22:41+00:00

commit 6d9e8c651dd979aa666bee15f086745f3ea9c4b3 upstream.

Patch series "use div64_ul() instead of div_u64() if the divisor is
unsigned long".

We were first inspired by commit b0ab99e7736a ("sched: Fix possible divide
by zero in avg_atom () calculation"), then refer to the recently analyzed
mm code, we found this suspicious place.

 201                 if (min) {
 202                         min *= this_bw;
 203                         do_div(min, tot_bw);
 204                 }

And we also disassembled and confirmed it:

  /usr/src/debug/kernel-4.9.168-016.ali3000/linux-4.9.168-016.ali3000.alios7.x86_64/mm/page-writeback.c: 201
  0xffffffff811c37da <__wb_calc_thresh+234>:      xor    %r10d,%r10d
  0xffffffff811c37dd <__wb_calc_thresh+237>:      test   %rax,%rax
  0xffffffff811c37e0 <__wb_calc_thresh+240>:      je 0xffffffff811c3800 <__wb_calc_thresh+272>
  /usr/src/debug/kernel-4.9.168-016.ali3000/linux-4.9.168-016.ali3000.alios7.x86_64/mm/page-writeback.c: 202
  0xffffffff811c37e2 <__wb_calc_thresh+242>:      imul   %r8,%rax
  /usr/src/debug/kernel-4.9.168-016.ali3000/linux-4.9.168-016.ali3000.alios7.x86_64/mm/page-writeback.c: 203
  0xffffffff811c37e6 <__wb_calc_thresh+246>:      mov    %r9d,%r10d    ---> truncates it to 32 bits here
  0xffffffff811c37e9 <__wb_calc_thresh+249>:      xor    %edx,%edx
  0xffffffff811c37eb <__wb_calc_thresh+251>:      div    %r10
  0xffffffff811c37ee <__wb_calc_thresh+254>:      imul   %rbx,%rax
  0xffffffff811c37f2 <__wb_calc_thresh+258>:      shr    $0x2,%rax
  0xffffffff811c37f6 <__wb_calc_thresh+262>:      mul    %rcx
  0xffffffff811c37f9 <__wb_calc_thresh+265>:      shr    $0x2,%rdx
  0xffffffff811c37fd <__wb_calc_thresh+269>:      mov    %rdx,%r10

This series uses div64_ul() instead of div_u64() if the divisor is
unsigned long, to avoid truncation to 32-bit on 64-bit platforms.

This patch (of 3):

The variables 'min' and 'max' are unsigned long and do_div truncates
them to 32 bits, which means it can test non-zero and be truncated to
zero for division.  Fix this issue by using div64_ul() instead.

Link: http://lkml.kernel.org/r/20200102081442.8273-2-wenyang@linux.alibaba.com
Fixes: 693108a8a667 ("writeback: make bdi->min/max_ratio handling cgroup writeback aware")
Signed-off-by: Wen Yang 
Reviewed-by: Andrew Morton 
Cc: Qian Cai 
Cc: Tejun Heo 
Cc: Jens Axboe 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm/memory_hotplug: don't free usage map when removing a re-added early section

2020-01-23T07:22:41+00:00

commit 8068df3b60373c390198f660574ea14c8098de57 upstream.

When we remove an early section, we don't free the usage map, as the
usage maps of other sections are placed into the same page.  Once the
section is removed, it is no longer an early section (especially, the
memmap is freed).  When we re-add that section, the usage map is reused,
however, it is no longer an early section.  When removing that section
again, we try to kfree() a usage map that was allocated during early
boot - bad.

Let's check against PageReserved() to see if we are dealing with an
usage map that was allocated during boot.  We could also check against
!(PageSlab(usage_page) || PageCompound(usage_page)), but PageReserved() is
cleaner.

Can be triggered using memtrace under ppc64/powernv:

  $ mount -t debugfs none /sys/kernel/debug/
  $ echo 0x20000000 > /sys/kernel/debug/powerpc/memtrace/enable
  $ echo 0x20000000 > /sys/kernel/debug/powerpc/memtrace/enable
   ------------[ cut here ]------------
   kernel BUG at mm/slub.c:3969!
   Oops: Exception in kernel mode, sig: 5 [#1]
   LE PAGE_SIZE=3D64K MMU=3DHash SMP NR_CPUS=3D2048 NUMA PowerNV
   Modules linked in:
   CPU: 0 PID: 154 Comm: sh Not tainted 5.5.0-rc2-next-20191216-00005-g0be1dba7b7c0 #61
   NIP kfree+0x338/0x3b0
   LR section_deactivate+0x138/0x200
   Call Trace:
     section_deactivate+0x138/0x200
     __remove_pages+0x114/0x150
     arch_remove_memory+0x3c/0x160
     try_remove_memory+0x114/0x1a0
     __remove_memory+0x20/0x40
     memtrace_enable_set+0x254/0x850
     simple_attr_write+0x138/0x160
     full_proxy_write+0x8c/0x110
     __vfs_write+0x38/0x70
     vfs_write+0x11c/0x2a0
     ksys_write+0x84/0x140
     system_call+0x5c/0x68
   ---[ end trace 4b053cbd84e0db62 ]---

The first invocation will offline+remove memory blocks.  The second
invocation will first add+online them again, in order to offline+remove
them again (usually we are lucky and the exact same memory blocks will
get "reallocated").

Tested on powernv with boot memory: The usage map will not get freed.
Tested on x86-64 with DIMMs: The usage map will get freed.

Using Dynamic Memory under a Power DLAPR can trigger it easily.

Triggering removal (I assume after previously removed+re-added) of
memory from the HMC GUI can crash the kernel with the same call trace
and is fixed by this patch.

Link: http://lkml.kernel.org/r/20191217104637.5509-1-david@redhat.com
Fixes: 326e1b8f83a4 ("mm/sparsemem: introduce a SECTION_IS_EARLY flag")
Signed-off-by: David Hildenbrand 
Tested-by: Pingfan Liu 
Cc: Dan Williams 
Cc: Oscar Salvador 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm, debug_pagealloc: don't rely on static keys too early

2020-01-23T07:22:40+00:00

commit 8e57f8acbbd121ecfb0c9dc13b8b030f86c6bd3b upstream.

Commit 96a2b03f281d ("mm, debug_pagelloc: use static keys to enable
debugging") has introduced a static key to reduce overhead when
debug_pagealloc is compiled in but not enabled.  It relied on the
assumption that jump_label_init() is called before parse_early_param()
as in start_kernel(), so when the "debug_pagealloc=on" option is parsed,
it is safe to enable the static key.

However, it turns out multiple architectures call parse_early_param()
earlier from their setup_arch().  x86 also calls jump_label_init() even
earlier, so no issue was found while testing the commit, but same is not
true for e.g.  ppc64 and s390 where the kernel would not boot with
debug_pagealloc=on as found by our QA.

To fix this without tricky changes to init code of multiple
architectures, this patch partially reverts the static key conversion
from 96a2b03f281d.  Init-time and non-fastpath calls (such as in arch
code) of debug_pagealloc_enabled() will again test a simple bool
variable.  Fastpath mm code is converted to a new
debug_pagealloc_enabled_static() variant that relies on the static key,
which is enabled in a well-defined point in mm_init() where it's
guaranteed that jump_label_init() has been called, regardless of
architecture.

[sfr@canb.auug.org.au: export _debug_pagealloc_enabled_early]
  Link: http://lkml.kernel.org/r/20200106164944.063ac07b@canb.auug.org.au
Link: http://lkml.kernel.org/r/20191219130612.23171-1-vbabka@suse.cz
Fixes: 96a2b03f281d ("mm, debug_pagelloc: use static keys to enable debugging")
Signed-off-by: Vlastimil Babka 
Signed-off-by: Stephen Rothwell 
Cc: Joonsoo Kim 
Cc: "Kirill A. Shutemov" 
Cc: Michal Hocko 
Cc: Vlastimil Babka 
Cc: Matthew Wilcox 
Cc: Mel Gorman 
Cc: Peter Zijlstra 
Cc: Borislav Petkov 
Cc: Qian Cai 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm: memcg/slab: call flush_memcg_workqueue() only if memcg workqueue is valid

2020-01-23T07:22:39+00:00

commit 2fe20210fc5f5e62644678b8f927c49f2c6f42a7 upstream.

When booting with amd_iommu=off, the following WARNING message
appears:

  AMD-Vi: AMD IOMMU disabled on kernel command-line
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 0 at kernel/workqueue.c:2772 flush_workqueue+0x42e/0x450
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.5.0-rc3-amd-iommu #6
  Hardware name: Lenovo ThinkSystem SR655-2S/7D2WRCZ000, BIOS D8E101L-1.00 12/05/2019
  RIP: 0010:flush_workqueue+0x42e/0x450
  Code: ff 0f 0b e9 7a fd ff ff 4d 89 ef e9 33 fe ff ff 0f 0b e9 7f fd ff ff 0f 0b e9 bc fd ff ff 0f 0b e9 a8 fd ff ff e8 52 2c fe ff <0f> 0b 31 d2 48 c7 c6 e0 88 c5 95 48 c7 c7 d8 ad f0 95 e8 19 f5 04
  Call Trace:
   kmem_cache_destroy+0x69/0x260
   iommu_go_to_state+0x40c/0x5ab
   amd_iommu_prepare+0x16/0x2a
   irq_remapping_prepare+0x36/0x5f
   enable_IR_x2apic+0x21/0x172
   default_setup_apic_routing+0x12/0x6f
   apic_intr_mode_init+0x1a1/0x1f1
   x86_late_time_init+0x17/0x1c
   start_kernel+0x480/0x53f
   secondary_startup_64+0xb6/0xc0
  ---[ end trace 30894107c3749449 ]---
  x2apic: IRQ remapping doesn't support X2APIC mode
  x2apic disabled

The warning is caused by the calling of 'kmem_cache_destroy()'
in free_iommu_resources(). Here is the call path:

  free_iommu_resources
    kmem_cache_destroy
      flush_memcg_workqueue
        flush_workqueue

The root cause is that the IOMMU subsystem runs before the workqueue
subsystem, which the variable 'wq_online' is still 'false'.  This leads
to the statement 'if (WARN_ON(!wq_online))' in flush_workqueue() is
'true'.

Since the variable 'memcg_kmem_cache_wq' is not allocated during the
time, it is unnecessary to call flush_memcg_workqueue().  This prevents
the WARNING message triggered by flush_workqueue().

Link: http://lkml.kernel.org/r/20200103085503.1665-1-ahuang12@lenovo.com
Fixes: 92ee383f6daab ("mm: fix race between kmem_cache destroy, create and deactivate")
Signed-off-by: Adrian Huang 
Reported-by: Xiaochun Lee 
Reviewed-by: Shakeel Butt 
Cc: Joerg Roedel 
Cc: Christoph Lameter 
Cc: Pekka Enberg 
Cc: David Rientjes 
Cc: Joonsoo Kim 
Cc: Michal Hocko 
Cc: Johannes Weiner 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm: memcg/slab: fix percpu slab vmstats flushing

2020-01-23T07:22:39+00:00

commit 4a87e2a25dc27131c3cce5e94421622193305638 upstream.

Currently slab percpu vmstats are flushed twice: during the memcg
offlining and just before freeing the memcg structure.  Each time percpu
counters are summed, added to the atomic counterparts and propagated up
by the cgroup tree.

The second flushing is required due to how recursive vmstats are
implemented: counters are batched in percpu variables on a local level,
and once a percpu value is crossing some predefined threshold, it spills
over to atomic values on the local and each ascendant levels.  It means
that without flushing some numbers cached in percpu variables will be
dropped on floor each time a cgroup is destroyed.  And with uptime the
error on upper levels might become noticeable.

The first flushing aims to make counters on ancestor levels more
precise.  Dying cgroups may resume in the dying state for a long time.
After kmem_cache reparenting which is performed during the offlining
slab counters of the dying cgroup don't have any chances to be updated,
because any slab operations will be performed on the parent level.  It
means that the inaccuracy caused by percpu batching will not decrease up
to the final destruction of the cgroup.  By the original idea flushing
slab counters during the offlining should minimize the visible
inaccuracy of slab counters on the parent level.

The problem is that percpu counters are not zeroed after the first
flushing.  So every cached percpu value is summed twice.  It creates a
small error (up to 32 pages per cpu, but usually less) which accumulates
on parent cgroup level.  After creating and destroying of thousands of
child cgroups, slab counter on parent level can be way off the real
value.

For now, let's just stop flushing slab counters on memcg offlining.  It
can't be done correctly without scheduling a work on each cpu: reading
and zeroing it during css offlining can race with an asynchronous
update, which doesn't expect values to be changed underneath.

With this change, slab counters on parent level will become eventually
consistent.  Once all dying children are gone, values are correct.  And
if not, the error is capped by 32 * NR_CPUS pages per dying cgroup.

It's not perfect, as slab are reparented, so any updates after the
reparenting will happen on the parent level.  It means that if a slab
page was allocated, a counter on child level was bumped, then the page
was reparented and freed, the annihilation of positive and negative
counter values will not happen until the child cgroup is released.  It
makes slab counters different from others, and it might want us to
implement flushing in a correct form again.  But it's also a question of
performance: scheduling a work on each cpu isn't free, and it's an open
question if the benefit of having more accurate counters is worth it.

We might also consider flushing all counters on offlining, not only slab
counters.

So let's fix the main problem now: make the slab counters eventually
consistent, so at least the error won't grow with uptime (or more
precisely the number of created and destroyed cgroups).  And think about
the accuracy of counters separately.

Link: http://lkml.kernel.org/r/20191220042728.1045881-1-guro@fb.com
Fixes: bee07b33db78 ("mm: memcontrol: flush percpu slab vmstats on kmem offlining")
Signed-off-by: Roman Gushchin 
Acked-by: Johannes Weiner 
Acked-by: Michal Hocko 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm/huge_memory.c: thp: fix conflict of above-47bit hint address and PMD alignment

2020-01-23T07:22:39+00:00

commit 97d3d0f9a1cf132c63c0b8b8bd497b8a56283dd9 upstream.

Patch series "Fix two above-47bit hint address vs.  THP bugs".

The two get_unmapped_area() implementations have to be fixed to provide
THP-friendly mappings if above-47bit hint address is specified.

This patch (of 2):

Filesystems use thp_get_unmapped_area() to provide THP-friendly
mappings.  For DAX in particular.

Normally, the kernel doesn't create userspace mappings above 47-bit,
even if the machine allows this (such as with 5-level paging on x86-64).
Not all user space is ready to handle wide addresses.  It's known that
at least some JIT compilers use higher bits in pointers to encode their
information.

Userspace can ask for allocation from full address space by specifying
hint address (with or without MAP_FIXED) above 47-bits.  If the
application doesn't need a particular address, but wants to allocate
from whole address space it can specify -1 as a hint address.

Unfortunately, this trick breaks thp_get_unmapped_area(): the function
would not try to allocate PMD-aligned area if *any* hint address
specified.

Modify the routine to handle it correctly:

 - Try to allocate the space at the specified hint address with length
   padding required for PMD alignment.
 - If failed, retry without length padding (but with the same hint
   address);
 - If the returned address matches the hint address return it.
 - Otherwise, align the address as required for THP and return.

The user specified hint address is passed down to get_unmapped_area() so
above-47bit hint address will be taken into account without breaking
alignment requirements.

Link: http://lkml.kernel.org/r/20191220142548.7118-2-kirill.shutemov@linux.intel.com
Fixes: b569bab78d8d ("x86/mm: Prepare to expose larger address space to userspace")
Signed-off-by: Kirill A. Shutemov 
Reported-by: Thomas Willhalm 
Tested-by: Dan Williams 
Cc: "Aneesh Kumar K . V" 
Cc: "Bruggeman, Otto G" 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm/shmem.c: thp, shmem: fix conflict of above-47bit hint address and PMD alignment

2020-01-23T07:22:39+00:00

commit 991589974d9c9ecb24ee3799ec8c415c730598a2 upstream.

Shmem/tmpfs tries to provide THP-friendly mappings if huge pages are
enabled.  But it doesn't work well with above-47bit hint address.

Normally, the kernel doesn't create userspace mappings above 47-bit,
even if the machine allows this (such as with 5-level paging on x86-64).
Not all user space is ready to handle wide addresses.  It's known that
at least some JIT compilers use higher bits in pointers to encode their
information.

Userspace can ask for allocation from full address space by specifying
hint address (with or without MAP_FIXED) above 47-bits.  If the
application doesn't need a particular address, but wants to allocate
from whole address space it can specify -1 as a hint address.

Unfortunately, this trick breaks THP alignment in shmem/tmp:
shmem_get_unmapped_area() would not try to allocate PMD-aligned area if
*any* hint address specified.

This can be fixed by requesting the aligned area if the we failed to
allocated at user-specified hint address.  The request with inflated
length will also take the user-specified hint address.  This way we will
not lose an allocation request from the full address space.

[kirill@shutemov.name: fold in a fixup]
  Link: http://lkml.kernel.org/r/20191223231309.t6bh5hkbmokihpfu@box
Link: http://lkml.kernel.org/r/20191220142548.7118-3-kirill.shutemov@linux.intel.com
Fixes: b569bab78d8d ("x86/mm: Prepare to expose larger address space to userspace")
Signed-off-by: Kirill A. Shutemov 
Cc: "Willhalm, Thomas" 
Cc: Dan Williams 
Cc: "Bruggeman, Otto G" 
Cc: "Aneesh Kumar K . V" 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

uaccess: Add non-pagefault user-space write function

2020-01-17T18:48:40+00:00

commit 1d1585ca0f48fe7ed95c3571f3e4a82b2b5045dc upstream.

Commit 3d7081822f7f ("uaccess: Add non-pagefault user-space read functions")
missed to add probe write function, therefore factor out a probe_write_common()
helper with most logic of probe_kernel_write() except setting KERNEL_DS, and
add a new probe_user_write() helper so it can be used from BPF side.

Again, on some archs, the user address space and kernel address space can
co-exist and be overlapping, so in such case, setting KERNEL_DS would mean
that the given address is treated as being in kernel address space.

Signed-off-by: Daniel Borkmann 
Signed-off-by: Alexei Starovoitov 
Acked-by: Andrii Nakryiko 
Cc: Masami Hiramatsu 
Link: https://lore.kernel.org/bpf/9df2542e68141bfa3addde631441ee45503856a8.1572649915.git.daniel@iogearbox.net
Signed-off-by: Greg Kroah-Hartman

mm/hugetlb: defer freeing of huge pages if in non-task context

2020-01-09T09:20:07+00:00

[ Upstream commit c77c0a8ac4c522638a8242fcb9de9496e3cdbb2d ]

The following lockdep splat was observed when a certain hugetlbfs test
was run:

  ================================
  WARNING: inconsistent lock state
  4.18.0-159.el8.x86_64+debug #1 Tainted: G        W --------- -  -
  --------------------------------
  inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
  swapper/30/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
  ffffffff9acdc038 (hugetlb_lock){+.?.}, at: free_huge_page+0x36f/0xaa0
  {SOFTIRQ-ON-W} state was registered at:
    lock_acquire+0x14f/0x3b0
    _raw_spin_lock+0x30/0x70
    __nr_hugepages_store_common+0x11b/0xb30
    hugetlb_sysctl_handler_common+0x209/0x2d0
    proc_sys_call_handler+0x37f/0x450
    vfs_write+0x157/0x460
    ksys_write+0xb8/0x170
    do_syscall_64+0xa5/0x4d0
    entry_SYSCALL_64_after_hwframe+0x6a/0xdf
  irq event stamp: 691296
  hardirqs last  enabled at (691296): [] _raw_spin_unlock_irqrestore+0x4b/0x60
  hardirqs last disabled at (691295): [] _raw_spin_lock_irqsave+0x22/0x81
  softirqs last  enabled at (691284): [] irq_enter+0xc3/0xe0
  softirqs last disabled at (691285): [] irq_exit+0x23e/0x2b0

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(hugetlb_lock);
    
      lock(hugetlb_lock);

   *** DEADLOCK ***
      :
  Call Trace:
   
   __lock_acquire+0x146b/0x48c0
   lock_acquire+0x14f/0x3b0
   _raw_spin_lock+0x30/0x70
   free_huge_page+0x36f/0xaa0
   bio_check_pages_dirty+0x2fc/0x5c0
   clone_endio+0x17f/0x670 [dm_mod]
   blk_update_request+0x276/0xe50
   scsi_end_request+0x7b/0x6a0
   scsi_io_completion+0x1c6/0x1570
   blk_done_softirq+0x22e/0x350
   __do_softirq+0x23d/0xad8
   irq_exit+0x23e/0x2b0
   do_IRQ+0x11a/0x200
   common_interrupt+0xf/0xf
   

Both the hugetbl_lock and the subpool lock can be acquired in
free_huge_page().  One way to solve the problem is to make both locks
irq-safe.  However, Mike Kravetz had learned that the hugetlb_lock is
held for a linear scan of ALL hugetlb pages during a cgroup reparentling
operation.  So it is just too long to have irq disabled unless we can
break hugetbl_lock down into finer-grained locks with shorter lock hold
times.

Another alternative is to defer the freeing to a workqueue job.  This
patch implements the deferred freeing by adding a free_hpage_workfn()
work function to do the actual freeing.  The free_huge_page() call in a
non-task context saves the page to be freed in the hpage_freelist linked
list in a lockless manner using the llist APIs.

The generic workqueue is used to process the work, but a dedicated
workqueue can be used instead if it is desirable to have the huge page
freed ASAP.

Thanks to Kirill Tkhai  for suggesting the use of
llist APIs which simplfy the code.

Link: http://lkml.kernel.org/r/20191217170331.30893-1-longman@redhat.com
Signed-off-by: Waiman Long 
Reviewed-by: Mike Kravetz 
Acked-by: Davidlohr Bueso 
Acked-by: Michal Hocko 
Reviewed-by: Kirill Tkhai 
Cc: Aneesh Kumar K.V 
Cc: Matthew Wilcox 
Cc: Andi Kleen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

mm/sparse.c: mark populate_section_memmap as __meminit

2020-01-09T09:20:06+00:00

[ Upstream commit 030eab4f9ffb469344c10a46bc02c5149db0a2a9 ]

Building the kernel on s390 with -Og produces the following warning:

  WARNING: vmlinux.o(.text+0x28dabe): Section mismatch in reference from the function populate_section_memmap() to the function .meminit.text:__populate_section_memmap()
  The function populate_section_memmap() references
  the function __meminit __populate_section_memmap().
  This is often because populate_section_memmap lacks a __meminit
  annotation or the annotation of __populate_section_memmap is wrong.

While -Og is not supported, in theory this might still happen with
another compiler or on another architecture.  So fix this by using the
correct section annotations.

[iii@linux.ibm.com: v2]
  Link: http://lkml.kernel.org/r/20191030151639.41486-1-iii@linux.ibm.com
Link: http://lkml.kernel.org/r/20191028165549.14478-1-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich 
Acked-by: David Hildenbrand 
Cc: Heiko Carstens 
Cc: Vasily Gorbik 
Cc: Oscar Salvador 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin