Under rare circumstances, task_function_call() can repeatedly fail and
cause a soft lockup.

There is a slight race where the process is no longer running on the cpu
we targeted by the time remote_function() runs.  The code will simply
try again.  If we are very unlucky, this will continue to fail, until a
watchdog fires.  This can happen in a heavily loaded, multi-core virtual
machine.

Reported-by:  <syzbot+bb4935a5c09b5ff79940@syzkaller.appspotmail.com>
Signed-off-by: Barret Rhoden <brho@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200414222920.121401-1-brho@google.com

Zhaoxin CPU has provided facilities for monitoring performance
via PMU (Performance Monitor Unit), but the functionality is unused so far.
Therefore, add support for zhaoxin pmu to make performance related
hardware events available.

The PMU is mostly an Intel Architectural PerfMon-v2 with a novel
errata for the ZXC line. It supports the following events:

  -----------------------------------------------------------------------------------------------------------------------------------
  Event                      | Event  | Umask |          Description
			     | Select |       |
  -----------------------------------------------------------------------------------------------------------------------------------
  cpu-cycles                 |  82h   |  00h  | unhalt core clock
  instructions               |  00h   |  00h  | number of instructions at retirement.
  cache-references           |  15h   |  05h  | number of fillq pushs at the current cycle.
  cache-misses               |  1ah   |  05h  | number of l2 miss pushed by fillq.
  branch-instructions        |  28h   |  00h  | counts the number of branch instructions retired.
  branch-misses              |  29h   |  00h  | mispredicted branch instructions at retirement.
  bus-cycles                 |  83h   |  00h  | unhalt bus clock
  stalled-cycles-frontend    |  01h   |  01h  | Increments each cycle the # of Uops issued by the RAT to RS.
  stalled-cycles-backend     |  0fh   |  04h  | RS0/1/2/3/45 empty
  L1-dcache-loads            |  68h   |  05h  | number of retire/commit load.
  L1-dcache-load-misses      |  4bh   |  05h  | retired load uops whose data source followed an L1 miss.
  L1-dcache-stores           |  69h   |  06h  | number of retire/commit Store,no LEA
  L1-dcache-store-misses     |  62h   |  05h  | cache lines in M state evicted out of L1D due to Snoop HitM or dirty line replacement.
  L1-icache-loads            |  00h   |  03h  | number of l1i cache access for valid normal fetch,including un-cacheable access.
  L1-icache-load-misses      |  01h   |  03h  | number of l1i cache miss for valid normal fetch,including un-cacheable miss.
  L1-icache-prefetches       |  0ah   |  03h  | number of prefetch.
  L1-icache-prefetch-misses  |  0bh   |  03h  | number of prefetch miss.
  dTLB-loads                 |  68h   |  05h  | number of retire/commit load
  dTLB-load-misses           |  2ch   |  05h  | number of load operations miss all level tlbs and cause a tablewalk.
  dTLB-stores                |  69h   |  06h  | number of retire/commit Store,no LEA
  dTLB-store-misses          |  30h   |  05h  | number of store operations miss all level tlbs and cause a tablewalk.
  dTLB-prefetches            |  64h   |  05h  | number of hardware pte prefetch requests dispatched out of the prefetch FIFO.
  dTLB-prefetch-misses       |  65h   |  05h  | number of hardware pte prefetch requests miss the l1d data cache.
  iTLB-load                  |  00h   |  00h  | actually counter instructions.
  iTLB-load-misses           |  34h   |  05h  | number of code operations miss all level tlbs and cause a tablewalk.
  -----------------------------------------------------------------------------------------------------------------------------------

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: CodyYao-oc <CodyYao-oc@zhaoxin.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1586747669-4827-1-git-send-email-CodyYao-oc@zhaoxin.com

Merge tag 'perf-core-for-mingo-5.8-20200420' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

 into perf/core

Pull perf/core fixes and improvements from Arnaldo Carvalho de Melo:

kernel + tools/perf:

  Alexey Budankov:

  - Introduce CAP_PERFMON to kernel and user space.

callchains:

  Adrian Hunter:

  - Allow using Intel PT to synthesize callchains for regular events.

  Kan Liang:

  - Stitch LBR records from multiple samples to get deeper backtraces,
    there are caveats, see the csets for details.

perf script:

  Andreas Gerstmayr:

  - Add flamegraph.py script

BPF:

  Jiri Olsa:

  - Synthesize bpf_trampoline/dispatcher ksymbol events.

perf stat:

  Arnaldo Carvalho de Melo:

  - Honour --timeout for forked workloads.

  Stephane Eranian:

  - Force error in fallback on :k events, to avoid counting nothing when
    the user asks for kernel events but is not allowed to.

perf bench:

  Ian Rogers:

  - Add event synthesis benchmark.

tools api fs:

  Stephane Eranian:

 - Make xxx__mountpoint() more scalable

libtraceevent:

  He Zhe:

  - Handle return value of asprintf.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge misc fixes from Andrew Morton:
 "15 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  tools/vm: fix cross-compile build
  coredump: fix null pointer dereference on coredump
  mm: shmem: disable interrupt when acquiring info->lock in userfaultfd_copy path
  shmem: fix possible deadlocks on shmlock_user_lock
  vmalloc: fix remap_vmalloc_range() bounds checks
  mm/shmem: fix build without THP
  mm/ksm: fix NULL pointer dereference when KSM zero page is enabled
  tools/build: tweak unused value workaround
  checkpatch: fix a typo in the regex for $allocFunctions
  mm, gup: return EINTR when gup is interrupted by fatal signals
  mm/hugetlb: fix a addressing exception caused by huge_pte_offset
  MAINTAINERS: add an entry for kfifo
  mm/userfaultfd: disable userfaultfd-wp on x86_32
  slub: avoid redzone when choosing freepointer location
  sh: fix build error in mm/init.c

Pull kvm fixes from Paolo Bonzini:
 "Bugfixes, and a few cleanups to the newly-introduced assembly language
  vmentry code for AMD"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: PPC: Book3S HV: Handle non-present PTEs in page fault functions
  kvm: Disable objtool frame pointer checking for vmenter.S
  MAINTAINERS: add a reviewer for KVM/s390
  KVM: s390: Fix PV check in deliverable_irqs()
  kvm: Handle reads of SandyBridge RAPL PMU MSRs rather than injecting #GP
  KVM: Remove CREATE_IRQCHIP/SET_PIT2 race
  KVM: SVM: Fix __svm_vcpu_run declaration.
  KVM: SVM: Do not setup frame pointer in __svm_vcpu_run
  KVM: SVM: Fix build error due to missing release_pages() include
  KVM: SVM: Do not mark svm_vcpu_run with STACK_FRAME_NON_STANDARD
  kvm: nVMX: match comment with return type for nested_vmx_exit_reflected
  kvm: nVMX: reflect MTF VM-exits if injected by L1
  KVM: s390: Return last valid slot if approx index is out-of-bounds
  KVM: Check validity of resolved slot when searching memslots
  KVM: VMX: Enable machine check support for 32bit targets
  KVM: SVM: move more vmentry code to assembly
  KVM: SVM: fix compilation with modular PSP and non-modular KVM

Pull virtio fixes and cleanups from Michael Tsirkin:

 - Some bug fixes

 - Cleanup a couple of issues that surfaced meanwhile

 - Disable vhost on ARM with OABI for now - to be fixed fully later in
   the cycle or in the next release.

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (24 commits)
  vhost: disable for OABI
  virtio: drop vringh.h dependency
  virtio_blk: add a missing include
  virtio-balloon: Avoid using the word 'report' when referring to free page hinting
  virtio-balloon: make virtballoon_free_page_report() static
  vdpa: fix comment of vdpa_register_device()
  vdpa: make vhost, virtio depend on menu
  vdpa: allow a 32 bit vq alignment
  drm/virtio: fix up for include file changes
  remoteproc: pull in slab.h
  rpmsg: pull in slab.h
  virtio_input: pull in slab.h
  remoteproc: pull in slab.h
  virtio-rng: pull in slab.h
  virtgpu: pull in uaccess.h
  tools/virtio: make asm/barrier.h self contained
  tools/virtio: define aligned attribute
  virtio/test: fix up after IOTLB changes
  vhost: Create accessors for virtqueues private_data
  vdpasim: Return status in vdpasim_get_status
  ...

Pull tpm fixes from Jarkko Sakkinen:
 "A few bug fixes"

* tag 'tpmdd-next-20200421' of git://git.infradead.org/users/jjs/linux-tpmdd:
  tpm/tpm_tis: Free IRQ if probing fails
  tpm: fix wrong return value in tpm_pcr_extend
  tpm: ibmvtpm: retry on H_CLOSED in tpm_ibmvtpm_send()
  tpm: Export tpm2_get_cc_attrs_tbl for ibmvtpm driver as module

Pull clang-format fixlets from Miguel Ojeda:
 "Two trivial clang-format changes:

   - Don't indent C++ namespaces (Ian Rogers)

   - The usual clang-format macro list update (Miguel Ojeda)"

* tag 'clang-format-for-linus-v5.7-rc3' of git://github.com/ojeda/linux:
  clang-format: Update with the latest for_each macro list
  clang-format: don't indent namespaces

Commit 7ed1c190 ("tools: fix cross-compile var clobbering") moved
the setup of the CC variable to tools/scripts/Makefile.include to make
the behavior consistent across all the tools Makefiles.

As the vm tools missed the include we end up with the wrong CC in a
cross-compiling evironment.

Fixes: 7ed1c190 (tools: fix cross-compile var clobbering)
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Martin Kelly <martin@martingkelly.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200416104748.25243-1-l.stach@pengutronix.de


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If the core_pattern is set to "|" and any process segfaults then we get
a null pointer derefernce while trying to coredump. The call stack shows:

    RIP: do_coredump+0x628/0x11c0

When the core_pattern has only "|" there is no use of trying the
coredump and we can check that while formating the corename and exit
with an error.

After this change I get:

    format_corename failed
    Aborting core

Fixes: 315c6926 ("coredump: split pipe command whitespace before expanding template")
Reported-by: Matthew Ruffell <matthew.ruffell@canonical.com>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Wise <pabs3@bonedaddy.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200416194612.21418-1-sudipm.mukherjee@gmail.com


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Syzbot reported the below lockdep splat:

    WARNING: possible irq lock inversion dependency detected
    5.6.0-rc7-syzkaller #0 Not tainted
    --------------------------------------------------------
    syz-executor.0/10317 just changed the state of lock:
    ffff888021d16568 (&(&info->lock)->rlock){+.+.}, at: spin_lock include/linux/spinlock.h:338 [inline]
    ffff888021d16568 (&(&info->lock)->rlock){+.+.}, at: shmem_mfill_atomic_pte+0x1012/0x21c0 mm/shmem.c:2407
    but this lock was taken by another, SOFTIRQ-safe lock in the past:
     (&(&xa->xa_lock)->rlock#5){..-.}

    and interrupts could create inverse lock ordering between them.

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

           CPU0                    CPU1
           ----                    ----
      lock(&(&info->lock)->rlock);
                                   local_irq_disable();
                                   lock(&(&xa->xa_lock)->rlock#5);
                                   lock(&(&info->lock)->rlock);
      <Interrupt>
        lock(&(&xa->xa_lock)->rlock#5);

     *** DEADLOCK ***

The full report is quite lengthy, please see:

  https://lore.kernel.org/linux-mm/alpine.LSU.2.11.2004152007370.13597@eggly.anvils/T/#m813b412c5f78e25ca8c6c7734886ed4de43f241d



It is because CPU 0 held info->lock with IRQ enabled in userfaultfd_copy
path, then CPU 1 is splitting a THP which held xa_lock and info->lock in
IRQ disabled context at the same time.  If softirq comes in to acquire
xa_lock, the deadlock would be triggered.

The fix is to acquire/release info->lock with *_irq version instead of
plain spin_{lock,unlock} to make it softirq safe.

Fixes: 4c27fe4c ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support")
Reported-by:  <syzbot+e27980339d305f2dbfd9@syzkaller.appspotmail.com>
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by:  <syzbot+e27980339d305f2dbfd9@syzkaller.appspotmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Link: http://lkml.kernel.org/r/1587061357-122619-1-git-send-email-yang.shi@linux.alibaba.com


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Recent commit 71725ed1 ("mm: huge tmpfs: try to split_huge_page()
when punching hole") has allowed syzkaller to probe deeper, uncovering a
long-standing lockdep issue between the irq-unsafe shmlock_user_lock,
the irq-safe xa_lock on mapping->i_pages, and shmem inode's info->lock
which nests inside xa_lock (or tree_lock) since 4.8's shmem_uncharge().

user_shm_lock(), servicing SysV shmctl(SHM_LOCK), wants
shmlock_user_lock while its caller shmem_lock() holds info->lock with
interrupts disabled; but hugetlbfs_file_setup() calls user_shm_lock()
with interrupts enabled, and might be interrupted by a writeback endio
wanting xa_lock on i_pages.

This may not risk an actual deadlock, since shmem inodes do not take
part in writeback accounting, but there are several easy ways to avoid
it.

Requiring interrupts disabled for shmlock_user_lock would be easy, but
it's a high-level global lock for which that seems inappropriate.
Instead, recall that the use of info->lock to guard info->flags in
shmem_lock() dates from pre-3.1 days, when races with SHMEM_PAGEIN and
SHMEM_TRUNCATE could occur: nowadays it serves no purpose, the only flag
added or removed is VM_LOCKED itself, and calls to shmem_lock() an inode
are already serialized by the caller.

Take info->lock out of the chain and the possibility of deadlock or
lockdep warning goes away.

Fixes: 4595ef88 ("shmem: make shmem_inode_info::lock irq-safe")
Reported-by:  <syzbot+c8a8197c8852f566b9d9@syzkaller.appspotmail.com>
Reported-by:  <syzbot+40b71e145e73f78f81ad@syzkaller.appspotmail.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2004161707410.16322@eggly.anvils
Link: https://lore.kernel.org/lkml/000000000000e5838c05a3152f53@google.com/
Link: https://lore.kernel.org/lkml/0000000000003712b305a331d3b1@google.com/


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

remap_vmalloc_range() has had various issues with the bounds checks it
promises to perform ("This function checks that addr is a valid
vmalloc'ed area, and that it is big enough to cover the vma") over time,
e.g.:

 - not detecting pgoff<<PAGE_SHIFT overflow

 - not detecting (pgoff<<PAGE_SHIFT)+usize overflow

 - not checking whether addr and addr+(pgoff<<PAGE_SHIFT) are the same
   vmalloc allocation

 - comparing a potentially wildly out-of-bounds pointer with the end of
   the vmalloc region

In particular, since commit fc970227 ("bpf: Add mmap() support for
BPF_MAP_TYPE_ARRAY"), unprivileged users can cause kernel null pointer
dereferences by calling mmap() on a BPF map with a size that is bigger
than the distance from the start of the BPF map to the end of the
address space.

This could theoretically be used as a kernel ASLR bypass, by using
whether mmap() with a given offset oopses or returns an error code to
perform a binary search over the poss...

Some optimizers don't notice that shmem_punch_compound() is always true
(PageTransCompound() being false) without CONFIG_TRANSPARENT_HUGEPAGE==y.

Use IS_ENABLED to help them to avoid the BUILD_BUG inside HPAGE_PMD_NR.

Fixes: 71725ed1 ("mm: huge tmpfs: try to split_huge_page() when punching hole")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2004142339170.10035@eggly.anvils


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

find_mergeable_vma() can return NULL.  In this case, it leads to a crash
when we access vm_mm(its offset is 0x40) later in write_protect_page.
And this case did happen on our server.  The following call trace is
captured in kernel 4.19 with the following patch applied and KSM zero
page enabled on our server.

  commit e86c59b1 ("mm/ksm: improve deduplication of zero pages with colouring")

So add a vma check to fix it.

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000040
  Oops: 0000 [#1] SMP NOPTI
  CPU: 9 PID: 510 Comm: ksmd Kdump: loaded Tainted: G OE 4.19.36.bsk.9-amd64 #4.19.36.bsk.9
  RIP: try_to_merge_one_page+0xc7/0x760
  Code: 24 58 65 48 33 34 25 28 00 00 00 89 e8 0f 85 a3 06 00 00 48 83 c4
        60 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 8b 46 08 a8 01 75 b8 <49>
        8b 44 24 40 4c 8d 7c 24 20 b9 07 00 00 00 4c 89 e6 4c 89 ff 48
  RSP: 0018:ffffadbdd9fffdb0 EFLAGS: 00010246
  RAX: ffffda83ffd4be08 RBX: ffffda83ffd4be40 RCX: 0000002c6e800000
  RDX: 0000000000000000 RSI: ffffda83ffd4be40 RDI: 0000000000000000
  RBP: ffffa11939f02ec0 R08: 0000000094e1a447 R09: 00000000abe76577
  R10: 0000000000000962 R11: 0000000000004e6a R12: 0000000000000000
  R13: ffffda83b1e06380 R14: ffffa18f31f072c0 R15: ffffda83ffd4be40
  FS: 0000000000000000(0000) GS:ffffa0da43b80000(0000) knlGS:0000000000000000
  CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000040 CR3: 0000002c77c0a003 CR4: 00000000007626e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  PKRU: 55555554
  Call Trace:
    ksm_scan_thread+0x115e/0x1960
    kthread+0xf5/0x130
    ret_from_fork+0x1f/0x30

[songmuchun@bytedance.com: if the vma is out of date, just exit]
  Link: http://lkml.kernel.org/r/20200416025034.29780-1-songmuchun@bytedance.com


[akpm@linux-foundation.org: add the conventional braces, replace /** with /*]
Fixes: e86c59b1 ("mm/ksm: improve deduplication of zero pages with colouring")
Co-developed-by: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Cc: Markus Elfring <Markus.Elfring@web.de>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200416025034.29780-1-songmuchun@bytedance.com
Link: http://lkml.kernel.org/r/20200414132905.83819-1-songmuchun@bytedance.com


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Clang has -Wself-assign enabled by default under -Wall, which always
gets -Werror'ed on this file, causing sync-compare-and-swap to be
disabled by default.

The generally-accepted way to spell "this value is intentionally
unused," is casting it to `void`.  This is accepted by both GCC and
Clang with -Wall enabled: https://godbolt.org/z/qqZ9r3



Signed-off-by: George Burgess IV <gbiv@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Link: http://lkml.kernel.org/r/20200414195638.156123-1-gbiv@google.com


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Here, we look for function such as 'netdev_alloc_skb_ip_align', so a '_'
is missing in the regex.

To make sure:
   grep -r --include=*.c skbip_a * | wc   ==>   0 results
   grep -r --include=*.c skb_ip_a * | wc  ==> 112 results

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Joe Perches <joe@perches.com>
Link: http://lkml.kernel.org/r/20200407190029.892-1-christophe.jaillet@wanadoo.fr


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

EINTR is the usual error code which other killable interfaces return.
This is the case for the other fatal_signal_pending break out from the
same function.  Make the code consistent.

ERESTARTSYS is also quite confusing because the signal is fatal and so
no restart will happen before returning to the userspace.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Link: http://lkml.kernel.org/r/20200409071133.31734-1-mhocko@kernel.org


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Our machine encountered a panic(addressing exception) after run for a
long time and the calltrace is:

    RIP: hugetlb_fault+0x307/0xbe0
    RSP: 0018:ffff9567fc27f808  EFLAGS: 00010286
    RAX: e800c03ff1258d48 RBX: ffffd3bb003b69c0 RCX: e800c03ff1258d48
    RDX: 17ff3fc00eda72b7 RSI: 00003ffffffff000 RDI: e800c03ff1258d48
    RBP: ffff9567fc27f8c8 R08: e800c03ff1258d48 R09: 0000000000000080
    R10: ffffaba0704c22a8 R11: 0000000000000001 R12: ffff95c87b4b60d8
    R13: 00005fff00000000 R14: 0000000000000000 R15: ffff9567face8074
    FS:  00007fe2d9ffb700(0000) GS:ffff956900e40000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: ffffd3bb003b69c0 CR3: 000000be67374000 CR4: 00000000003627e0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
    Call Trace:
      follow_hugetlb_page+0x175/0x540
      __get_user_pages+0x2a0/0x7e0
      __get_user_pages_unlocked+0x15d/0x210
      __gfn_to_pfn_memslot+0x3c5/0x460 [kvm]
      try_async_pf+0x6e/0x2a0 [kvm]
      tdp_page_fault+0x151/0x2d0 [kvm]
     ...
      kvm_arch_vcpu_ioctl_run+0x330/0x490 [kvm]
      kvm_vcpu_ioctl+0x309/0x6d0 [kvm]
      do_vfs_ioctl+0x3f0/0x540
      SyS_ioctl+0xa1/0xc0
      system_call_fastpath+0x22/0x27

For 1G hugepages, huge_pte_offset() wants to return NULL or pudp, but it
may return a wrong 'pmdp' if there is a race.  Please look at the
following code snippet:

    ...
    pud = pud_offset(p4d, addr);
    if (sz != PUD_SIZE && pud_none(*pud))
        return NULL;
    /* hugepage or swap? */
    if (pud_huge(*pud) || !pud_present(*pud))
        return (pte_t *)pud;

    pmd = pmd_offset(pud, addr);
    if (sz != PMD_SIZE && pmd_none(*pmd))
        return NULL;
    /* hugepage or swap? */
    if (pmd_huge(*pmd) || !pmd_present(*pmd))
        return (pte_t *)pmd;
    ...

The following sequence would trigger this bug:

 - CPU0: sz = PUD_SIZE and *pud = 0 , continue
 - CPU0: "pud_huge(*pud)" is false
 - CPU1: calling hugetlb_no_page and set *pud to xxxx8e7(PRESENT)
 - CPU0: "!pud_present(*pud)" is false, continue
 - CPU0: pmd = pmd_offset(pud, addr) and maybe return a wrong pmdp

However, we want CPU0 to return NULL or pudp in this case.

We must make sure there is exactly one dereference of pud and pmd.

Signed-off-by: Longpeng <longpeng2@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200413010342.771-1-longpeng2@huawei.com


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Kfifo has been written by Stefani Seibold and she's implicitly expected
to Ack any changes to it.  She's not however officially listed as kfifo
maintainer which leads to delays in patch review.  This patch proposes
to add an explitic entry for kfifo to MAINTAINERS file.

[akpm@linux-foundation.org: alphasort F: entries, per Joe]
[akpm@linux-foundation.org: remove colon, per Bartosz]
Link: http://lkml.kernel.org/r/20200124174533.21815-1-brgl@bgdev.pl
Link: http://lkml.kernel.org/r/20200413104250.26683-1-brgl@bgdev.pl


Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Userfaultfd-wp is not yet working on 32bit hosts, but it's accidentally
enabled previously.  Disable it.

Fixes: 5a281062 ("userfaultfd: wp: add WP pagetable tracking to x86")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Link: http://lkml.kernel.org/r/20200413141608.109211-1-peterx@redhat.com


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Marco Elver reported system crashes when booting with "slub_debug=Z".

The freepointer location (s->offset) was not taking into account that
the "inuse" size that includes the redzone area should not be used by
the freelist pointer.  Change the calculation to save the area of the
object that an inline freepointer may be written into.

Fixes: 3202fa62 ("slub: relocate freelist pointer to middle of object")
Reported-by: Marco Elver <elver@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Marco Elver <elver@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Link: http://lkml.kernel.org/r/202004151054.BD695840@keescook
Link: https://lore.kernel.org/linux-mm/20200415164726.GA234932@google.com


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The closing parenthesis is missing.

Fixes: bfeb022f ("mm/memory_hotplug: add pgprot_t to mhp_params")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Link: http://lkml.kernel.org/r/20200413014743.16353-1-masahiroy@kernel.org


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'kvm-ppc-fixes-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into kvm-master

PPC KVM fix for 5.7

- Fix a regression introduced in the last merge window, which results
  in guests in HPT mode dying randomly.

Merge tag 'kvm-s390-master-5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-master

KVM: s390: Fix for 5.7 and maintainer update

- Silence false positive lockdep warning
- add Claudio as reviewer

Since cd758a9b "KVM: PPC: Book3S HV: Use __gfn_to_pfn_memslot in HPT
page fault handler", it's been possible in fairly rare circumstances to
load a non-present PTE in kvmppc_book3s_hv_page_fault() when running a
guest on a POWER8 host.

Because that case wasn't checked for, we could misinterpret the non-present
PTE as being a cache-inhibited PTE.  That could mismatch with the
corresponding hash PTE, which would cause the function to fail with -EFAULT
a little further down.  That would propagate up to the KVM_RUN ioctl()
generally causing the KVM userspace (usually qemu) to fall over.

This addresses the problem by catching that case and returning to the guest
instead.

For completeness, this fixes the radix page fault handler in the same
way.  For radix this didn't cause any obvious misbehaviour, because we
ended up putting the non-present PTE into the guest's partition-scoped
page tables, leading immediately to another hypervisor data/instruction
storage interrupt, which would go through the page fault path again
and fix things up.

Fixes: cd758a9b "KVM: PPC: Book3S HV: Use __gfn_to_pfn_memslot in HPT page fault handler"
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1820402


Reported-by: David Gibson <david@gibson.dropbear.id.au>
Tested-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

Frame pointers are completely broken by vmenter.S because it clobbers
RBP:

  arch/x86/kvm/svm/vmenter.o: warning: objtool: __svm_vcpu_run()+0xe4: BP used as a scratch register

That's unavoidable, so just skip checking that file when frame pointers
are configured in.

On the other hand, ORC can handle that code just fine, so leave objtool
enabled in the !FRAME_POINTER case.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Message-Id: <01fae42917bacad18be8d2cbc771353da6603473.1587398610.git.jpoimboe@redhat.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Fixes: 199cd1d7 ("KVM: SVM: Split svm_vcpu_run inline assembly to separate file")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Call disable_interrupts() if we have to revert to polling in order not to
unnecessarily reserve the IRQ for the life-cycle of the driver.

Cc: stable@vger.kernel.org # 4.5.x
Reported-by: Hans de Goede <hdegoede@redhat.com>
Fixes: e3837e74 ("tpm_tis: Refactor the interrupt setup")
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

For the algorithm that does not match the bank, a positive
value EINVAL is returned here. I think this is a typo error.
It is necessary to return an error value.

Cc: stable@vger.kernel.org # 5.4.x
Fixes: 9f75c822 ("KEYS: trusted: correctly initialize digests and fix locking issue")
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

tpm_ibmvtpm_send() can fail during PowerVM Live Partition Mobility resume
with an H_CLOSED return from ibmvtpm_send_crq().  The PAPR says, 'The
"partner partition suspended" transport event disables the associated CRQ
such that any H_SEND_CRQ hcall() to the associated CRQ returns H_Closed
until the CRQ has been explicitly enabled using the H_ENABLE_CRQ hcall.'
This patch adds a check in tpm_ibmvtpm_send() for an H_CLOSED return from
ibmvtpm_send_crq() and in that case calls tpm_ibmvtpm_resume() and
retries the ibmvtpm_send_crq() once.

Cc: stable@vger.kernel.org # 3.7.x
Fixes: 132f7629 ("drivers/char/tpm: Add new device driver to support IBM vTPM")
Reported-by: Linh Pham <phaml@us.ibm.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: George Wilson <gcwilson@linux.ibm.com>
Tested-by: Linh Pham <phaml@us.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

This patch fixes the following problem when the ibmvtpm driver
is built as a module:

ERROR: modpost: "tpm2_get_cc_attrs_tbl" [drivers/char/tpm/tpm_ibmvtpm.ko] undefined!
make[1]: *** [scripts/Makefile.modpost:94: __modpost] Error 1
make: *** [Makefile:1298: modules] Error 2

Fixes: 18b3670d ("tpm: ibmvtpm: Add support for TPM2")
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

vhost is currently broken on the some ARM configs.

The reason is that the ring element addresses are passed between
components with different alignments assumptions. Thus, if
guest selects a pointer and host then gets and dereferences
it, then alignment assumed by the host's compiler might be
greater than the actual alignment of the pointer.
compiler on the host from assuming pointer is aligned.

This actually triggers on ARM with -mabi=apcs-gnu - which is a
deprecated configuration. With this OABI, compiler assumes that
all structures are 4 byte aligned - which is stronger than
virtio guarantees for available and used rings, which are
merely 2 bytes. Thus a guest without -mabi=apcs-gnu running
on top of host with -mabi=apcs-gnu will be broken.

The correct fix is to force alignment of structures - however
that is an intrusive fix that's best deferred until the next release.

We didn't previously support such ancient systems at all - this surfaced
after vdpa support prompted removing dependency of vhost on
VIRTULIZATION. So for now, let's just add something along the lines of

	depends on !ARM || AEABI

to the virtio Kconfig declaration, and add a comment that it has to do
with struct member alignment.

Note: we can't make VHOST and VHOST_RING themselves have
a dependency since these are selected. Add a new symbol for that.

We should be able to drop this dependency down the road.

Fixes: 20c384f1 ("vhost: refine vhost and vringh kconfig")
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Suggested-by: Richard Earnshaw <Richard.Earnshaw@arm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20200417152936.772256-1-imbrenda@linux.ibm.com

The diag 0x44 handler, which handles a directed yield, goes into a
a codepath that does a kvm_for_each_vcpu() and ultimately
deliverable_irqs().  The new check for kvm_s390_pv_cpu_is_protected()
contains an assertion that the vcpu->mutex is held, which isn't going
to be the case in this scenario.

The result is a plethora of these messages if the lock debugging
is enabled, and thus an implication that we have a problem.

  WARNING: CPU: 9 PID: 16167 at arch/s390/kvm/kvm-s390.h:239 deliverable_irqs+0x1c6/0x1d0 [kvm]
  ...snip...
  Call Trace:
   [<000003ff80429bf2>] deliverable_irqs+0x1ca/0x1d0 [kvm]
  ([<000003ff80429b34>] deliverable_irqs+0x10c/0x1d0 [kvm])
   [<000003ff8042ba82>] kvm_s390_vcpu_has_irq+0x2a/0xa8 [kvm]
   [<000003ff804101e2>] kvm_arch_dy_runnable+0x22/0x38 [kvm]
   [<000003ff80410284>] kvm_vcpu_on_spin+0x8c/0x1d0 [kvm]
   [<000003ff80436888>] kvm_s390_handle_diag+0x3b0/0x768 [kvm]
   [<000003ff80425af4>] kvm_handle_sie_intercept+0x1cc/0xcd0 [kvm]
   [<000003ff80422bb0>] __vcpu_run+0x7b8/0xfd0 [kvm]
   [<000003ff80423de6>] kvm_arch_vcpu_ioctl_run+0xee/0x3e0 [kvm]
   [<000003ff8040ccd8>] kvm_vcpu_ioctl+0x2c8/0x8d0 [kvm]
   [<00000001504ced06>] ksys_ioctl+0xae/0xe8
   [<00000001504cedaa>] __s390x_sys_ioctl+0x2a/0x38
   [<0000000150cb9034>] system_call+0xd8/0x2d8
  2 locks held by CPU 2/KVM/16167:
   #0: 00000001951980c0 (&vcpu->mutex){+.+.}, at: kvm_vcpu_ioctl+0x90/0x8d0 [kvm]
   #1: 000000019599c0f0 (&kvm->srcu){....}, at: __vcpu_run+0x4bc/0xfd0 [kvm]
  Last Breaking-Event-Address:
   [<000003ff80429b34>] deliverable_irqs+0x10c/0x1d0 [kvm]
  irq event stamp: 11967
  hardirqs last  enabled at (11975): [<00000001502992f2>] console_unlock+0x4ca/0x650
  hardirqs last disabled at (11982): [<0000000150298ee8>] console_unlock+0xc0/0x650
  softirqs last  enabled at (7940): [<0000000150cba6ca>] __do_softirq+0x422/0x4d8
  softirqs last disabled at (7929): [<00000001501cd688>] do_softirq_own_stack+0x70/0x80

Considering what's being done here, let's fix this by removing the
mutex assertion rather than acquiring the mutex for every other vcpu.

Fixes: 201ae986 ("KVM: s390: protvirt: Implement interrupt injection")
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/20200415190353.63625-1-farman@linux.ibm.com


Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

When remapping a mapping where a portion of a VMA is remapped
into another portion of the VMA it can cause the VMA to become
split. During the copy_vma operation the VMA can actually
be remerged if it's an anonymous VMA whose pages have not yet
been faulted. This isn't normally a problem because at the end
of the remap the original portion is unmapped causing it to
become split again.

However, MREMAP_DONTUNMAP leaves that original portion in place which
means that the VMA which was split and then remerged is not actually
split at the end of the mremap. This patch fixes a bug where
we don't detect that the VMAs got remerged and we end up
putting back VM_ACCOUNT on the next mapping which is completely
unreleated. When that next mapping is unmapped it results in
incorrectly unaccounting for the memory which was never accounted,
and eventually we will underflow on the memory comittment.

There is also another issue which is similar, we're currently
accouting for the number of pages in the new_vma but that's wrong.
We need to account for the length of the remap operation as that's
all that is being added. If there was a mapping already at that
location its comittment would have been adjusted as part of
the munmap at the start of the mremap.

A really simple repro can be seen in:
https://gist.github.com/bgaff/e101ce99da7d9a8c60acc641d07f312c



Fixes: e346b381 ("mm/mremap: add MREMAP_DONTUNMAP to mremap()")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Brian Geffon <bgeffon@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull clk fixes from Stephen Boyd:
 "Two build fixes for a couple clk drivers and a fix for the Unisoc
  serial clk where we want to keep it on for earlycon"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: sprd: don't gate uart console clock
  clk: mmp2: fix link error without mmp2
  clk: asm9260: fix __clk_hw_register_fixed_rate_with_accuracy typo

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

  objtool:

   - Ignore the double UD2 which is emitted in BUG() when
     CONFIG_UBSAN_TRAP is enabled.

   - Support clang non-section symbols in objtool ORC dump

   - Fix switch table detection in .text.unlikely

   - Make the BP scratch register warning more robust.

  x86:

   - Increase microcode maximum patch size for AMD to cope with new CPUs
     which have a larger patch size.

   - Fix a crash in the resource control filesystem when the removal of
     the default resource group is attempted.

   - Preserve Code and Data Prioritization enabled state accross CPU
     hotplug.

   - Update split lock cpu matching to use the new X86_MATCH macros.

   - Change the split lock enumeration as Intel finaly decided that the
     IA32_CORE_CAPABILITIES bits are not architectural contrary to what
     the SDM claims. !@#%$^!

   - Add Tremont CPU models to the split lock detection cpu match.

   - Add a missing static attribute to make sparse happy"

* tag 'x86-urgent-2020-04-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/split_lock: Add Tremont family CPU models
  x86/split_lock: Bits in IA32_CORE_CAPABILITIES are not architectural
  x86/resctrl: Preserve CDP enable over CPU hotplug
  x86/resctrl: Fix invalid attempt at removing the default resource group
  x86/split_lock: Update to use X86_MATCH_INTEL_FAM6_MODEL()
  x86/umip: Make umip_insns static
  x86/microcode/AMD: Increase microcode PATCH_MAX_SIZE
  objtool: Make BP scratch register warning more robust
  objtool: Fix switch table detection in .text.unlikely
  objtool: Support Clang non-section symbols in ORC generation
  objtool: Support Clang non-section symbols in ORC dump
  objtool: Fix CONFIG_UBSAN_TRAP unreachable warnings

Pull time namespace fix from Thomas Gleixner:
 "An update for the proc interface of time namespaces: Use symbolic
  names instead of clockid numbers. The usability nuisance of numbers
  was noticed by Michael when polishing the man page"

* tag 'timers-urgent-2020-04-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  proc, time/namespace: Show clock symbolic names in /proc/pid/timens_offsets

Pull perf tooling fixes and updates from Thomas Gleixner:

 - Fix the header line of perf stat output for '--metric-only --per-socket'

 - Fix the python build with clang

 - The usual tools UAPI header synchronization

* tag 'perf-urgent-2020-04-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tools headers: Synchronize linux/bits.h with the kernel sources
  tools headers: Adopt verbatim copy of compiletime_assert() from kernel sources
  tools headers: Update x86's syscall_64.tbl with the kernel sources
  tools headers UAPI: Sync drm/i915_drm.h with the kernel sources
  tools headers UAPI: Update tools's copy of drm.h headers
  tools headers kvm: Sync linux/kvm.h with the kernel sources
  tools headers UAPI: Sync linux/fscrypt.h with the kernel sources
  tools include UAPI: Sync linux/vhost.h with the kernel sources
  tools arch x86: Sync asm/cpufeatures.h with the kernel sources
  tools headers UAPI: Sync linux/mman.h with the kernel
  tools headers UAPI: Sync sched.h with the kernel
  tools headers: Update linux/vdso.h and grab a copy of vdso/const.h
  perf stat: Fix no metric header if --per-socket and --metric-only set
  perf python: Check if clang supports -fno-semantic-interposition
  tools arch x86: Sync the msr-index.h copy with the kernel sources