In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning
by explicitly adding a break statement instead of just letting the code
fall through to the next case.

Link: https://github.com/KSPP/linux/issues/115Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/03497331f088a938d7a728e7a689bd7953139429.1605896059.git.gustavoars@kernel.orgSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Fast commit on-disk format is designed such that the replay of these
tags can be idempotent. This patch adds documentation in the code in
form of comments and in form kernel docs that describes these
characteristics. This patch also adds a TODO item needed to ensure
kernel fast commit replay idempotence.
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201119232822.1860882-1-harshadshirwadkar@gmail.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

There are no callers of the EXT4_CURRENT_REV macro, so remove it.
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/1605164202-31120-1-git-send-email-kaixuxia@tencent.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

The ext4_find_extent() function never returns NULL, it returns error
pointers.

Fixes: 44059e503b03 ("ext4: fast commit recovery path")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20201023112232.GB282278@mwandaSigned-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

Check for valid block size directly by validating s_log_block_size; we
were doing this in two places.  First, by calculating blocksize via
BLOCK_SIZE << s_log_block_size, and then checking that the blocksize
was valid.  And then secondly, by checking s_log_block_size directly.

The first check is not reliable, and can trigger an UBSAN warning if
s_log_block_size on a maliciously corrupted superblock is greater than
22.  This is harmless, since the second test will correctly reject the
maliciously fuzzed file system, but to make syzbot shut up, and
because the two checks are duplicative in any case, delete the
blocksize check, and move the s_log_block_size earlier in
ext4_fill_super().
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reported-by: syzbot+345b75652b1d24227443@syzkaller.appspotmail.com

When freeing metadata, we will create an ext4_free_data and
insert it into the pending free list.  After the current
transaction is committed, the object will be freed.

ext4_mb_free_metadata() will check whether the area to be freed
overlaps with the pending free list. If true, return directly. At this
time, ext4_free_data is leaked.  Fortunately, the probability of this
problem is small, since it only occurs if the file system is corrupted
such that a block is claimed by more one inode and those inodes are
deleted within a single jbd2 transaction.
Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Link: https://lore.kernel.org/r/1604764698-4269-8-git-send-email-brookxu@tencent.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/1604764698-4269-7-git-send-email-brookxu@tencent.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Since ext4_data_block_valid() has been renamed to ext4_inode_block_valid(),
the related comments need to be updated.
Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/1604764698-4269-5-git-send-email-brookxu@tencent.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

The code of mb_find_order_for_block is a bit obscure, but we can
simplify it with mb_find_buddy(), make the code more concise.
Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/1604764698-4269-3-git-send-email-brookxu@tencent.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

After this patch (163a203d), if an abnormal bitmap is detected, we
will mark the group as corrupt, and we will not use this group in
the future. Therefore, it should be meaningless to regenerate the
buddy bitmap of this group, It might be better to delete it.
Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/1604764698-4269-2-git-send-email-brookxu@tencent.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

There are currently multiple forms of assertion, such as J_ASSERT().
J_ASEERT() is provided for the jbd module, which is a public module.
Maybe we should use custom ASSERT() like other file systems, such as
xfs, which would be better.
Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/1604764698-4269-1-git-send-email-brookxu@tencent.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Right now, it is hard to understand which quota journalling type is enabled:
you need to be quite familiar with kernel code and trace it or really
understand what different combinations of fs flags/mount options lead to.

This patch adds printing of current quota jounalling mode on each
mount/remount, thus making it easier to check it at a glance/in autotests.
The semantics is similar to ext4 data journalling modes:

* journalled - quota configured, journalling will be enabled
* writeback  - quota configured, journalling won't be enabled
* none       - quota isn't configured
* disabled   - kernel compiled without CONFIG_QUOTA feature
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/1603336860-16153-2-git-send-email-dotdot@yandex-team.ruSigned-off-by: Roman Anufriev <dotdot@yandex-team.ru>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Right now, there are several places, where we check whether fs is
capable of enabling quota or if quota is journalled with quite long
and non-self-descriptive condition statements.

This patch wraps these statements into helpers for better readability
and easier usage.

Link: https://lore.kernel.org/r/1603336860-16153-1-git-send-email-dotdot@yandex-team.ruReviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Roman Anufriev <dotdot@yandex-team.ru>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Variable ex is assigned a variable that is not being read, the assignment
is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20201021132326.148052-1-colin.king@canonical.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

bv_page can't be NULL in a valid bio_vec, so we can remove the NULL check,
as we did in other places when calling bio_for_each_segment_all() to go
through all bio_vec of a bio.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Xianting Tian <tian.xianting@h3c.com>
Link: https://lore.kernel.org/r/20201020082201.34257-1-tian.xianting@h3c.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

The out_fail branch path don't release the bh and the second bh is
valid only in the for statement, so we don't need to set them to NULL.
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Reviewed-by: zhangyi (F) <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/1603194069-17557-1-git-send-email-kaixuxia@tencent.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

We used LockDoc to derive locking rules for each member
of struct transaction_t.
Based on those results, we extended the existing documentation
by more members of struct transaction_t, and updated the existing
documentation.

Link: https://lore.kernel.org/r/10cfbef1-994c-c604-f8a6-b1042fcc622f@tu-dortmund.deSigned-off-by: Alexander Lochmann <alexander.lochmann@tu-dortmund.de>
Signed-off-by: Horst Schirmeier <horst.schirmeier@tu-dortmund.de>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Pull HID fixes from Jiri Kosina:

 - Various functionality / regression fixes for Logitech devices from
   Hans de Goede

 - Fix for (recently added) GPIO support in mcp2221 driver from Lars
   Povlsen

 - Power management handling fix/quirk in i2c-hid driver for certain
   BIOSes that have strange aproach to power-cycle from Hans de Goede

 - a few device ID additions and device-specific quirks

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid:
  HID: logitech-dj: Fix Dinovo Mini when paired with a MX5x00 receiver
  HID: logitech-dj: Fix an error in mse_bluetooth_descriptor
  HID: Add Logitech Dinovo Edge battery quirk
  HID: logitech-hidpp: Add HIDPP_CONSUMER_VENDOR_KEYS quirk for the Dinovo Edge
  HID: logitech-dj: Handle quad/bluetooth keyboards with a builtin trackpad
  HID: add HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE for Gamevice devices
  HID: mcp2221: Fix GPIO output handling
  HID: hid-sensor-hub: Fix issue with devices with no report ID
  HID: i2c-hid: Put ACPI enumerated devices in D3 on shutdown
  HID: add support for Sega Saturn
  HID: cypress: Support Varmilo Keyboards' media hotkeys
  HID: ite: Replace ABS_MISC 120/121 events with touchpad on/off keypresses
  HID: logitech-hidpp: Add PID for MX Anywhere 2
  HID: uclogic: Add ID for Trust Flex Design Tablet

Pull scheduler fixes from Thomas Gleixner:
 "A couple of scheduler fixes:

   - Make the conditional update of the overutilized state work
     correctly by caching the relevant flags state before overwriting
     them and checking them afterwards.

   - Fix a data race in the wakeup path which caused loadavg on ARM64
     platforms to become a random number generator.

   - Fix the ordering of the iowaiter accounting operations so it can't
     be decremented before it is incremented.

   - Fix a bug in the deadline scheduler vs. priority inheritance when a
     non-deadline task A has inherited the parameters of a deadline task
     B and then blocks on a non-deadline task C.

     The second inheritance step used the static deadline parameters of
     task A, which are usually 0, instead of further propagating task
     B's parameters. The zero initialized parameters trigger a bug in
     the deadline scheduler"

* tag 'sched-urgent-2020-11-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Fix priority inheritance with multiple scheduling classes
  sched: Fix rq->nr_iowait ordering
  sched: Fix data-race in wakeup
  sched/fair: Fix overutilized update in enqueue_task_fair()

Pull perf fix from Thomas Gleixner:
 "A single fix for the x86 perf sysfs interfaces which used kobject
  attributes instead of device attributes and therefore making clang's
  control flow integrity checker upset"

* tag 'perf-urgent-2020-11-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86: fix sysfs type mismatches

Pull locking fix from Thomas Gleixner:
 "A single fix for lockdep which makes the recursion protection cover
  graph lock/unlock"

* tag 'locking-urgent-2020-11-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Put graph lock/unlock under lock_recursion protection

Pull EFI fixes from Borislav Petkov:
 "Forwarded EFI fixes from Ard Biesheuvel:

   - fix memory leak in efivarfs driver

   - fix HYP mode issue in 32-bit ARM version of the EFI stub when built
     in Thumb2 mode

   - avoid leaking EFI pgd pages on allocation failure"

* tag 'efi-urgent-for-v5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/x86: Free efi_pgd with free_pages()
  efivarfs: fix memory leak in efivarfs_create()
  efi/arm: set HSCTLR Thumb2 bit correctly for HVC calls from HYP

Pull x86 fixes from Borislav Petkov:

 - An IOMMU VT-d build fix when CONFIG_PCI_ATS=n along with a revert of
   same because the proper one is going through the IOMMU tree (Thomas
   Gleixner)

 - An Intel microcode loader fix to save the correct microcode patch to
   apply during resume (Chen Yu)

 - A fix to not access user memory of other processes when dumping
   opcode bytes (Thomas Gleixner)

* tag 'x86_urgent_for_v5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "iommu/vt-d: Take CONFIG_PCI_ATS into account"
  x86/dumpstack: Do not try to access user space code of other tasks
  x86/microcode/intel: Check patch signature before saving microcode for early loading
  iommu/vt-d: Take CONFIG_PCI_ATS into account

Merge misc fixes from Andrew Morton:
 "8 patches.

  Subsystems affected by this patch series: mm (madvise, pagemap,
  readahead, memcg, userfaultfd), kbuild, and vfs"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: fix madvise WILLNEED performance problem
  libfs: fix error cast of negative value in simple_attr_write()
  mm/userfaultfd: do not access vma->vm_mm after calling handle_userfault()
  mm: memcg/slab: fix root memcg vmstats
  mm: fix readahead_page_batch for retry entries
  mm: fix phys_to_target_node() and memory_add_physaddr_to_nid() exports
  compiler-clang: remove version check for BPF Tracing
  mm/madvise: fix memory leak from process_madvise

Pull staging and IIO fixes from Greg KH:
 "Here are some small Staging and IIO driver fixes for 5.10-rc5. They
  include:

   - IIO fixes for reported regressions and problems

   - new device ids for IIO drivers

   - new device id for rtl8723bs driver

   - staging ralink driver Kconfig dependency fix

   - staging mt7621-pci bus resource fix

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

* tag 'staging-5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio: accel: kxcjk1013: Add support for KIOX010A ACPI DSM for setting tablet-mode
  iio: accel: kxcjk1013: Replace is_smo8500_device with an acpi_type enum
  docs: ABI: testing: iio: stm32: remove re-introduced unsupported ABI
  iio: light: fix kconfig dependency bug for VCNL4035
  iio/adc: ingenic: Fix AUX/VBAT readings when touchscreen is used
  iio/adc: ingenic: Fix battery VREF for JZ4770 SoC
  staging: rtl8723bs: Add 024c:0627 to the list of SDIO device-ids
  staging: ralink-gdma: fix kconfig dependency bug for DMA_RALINK
  staging: mt7621-pci: avoid to request pci bus resources
  iio: imu: st_lsm6dsx: set 10ms as min shub slave timeout
  counter/ti-eqep: Fix regmap max_register
  iio: adc: stm32-adc: fix a regression when using dma and irq
  iio: adc: mediatek: fix unset field
  iio: cros_ec: Use default frequencies when EC returns invalid information

Pull tty fixes from Greg KH:
 "Here are some small tty/serial fixes for 5.10-rc5 that resolve some
  reported issues:

   - speakup crash when telling the kernel to use a device that isn't
     really there

   - imx serial driver fixes for reported problems

   - ar933x_uart driver fix for probe error handling path

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

* tag 'tty-5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: ar933x_uart: disable clk on error handling path in probe
  tty: serial: imx: keep console clocks always on
  speakup: Do not let the line discipline be used several times
  tty: serial: imx: fix potential deadlock

Pull ext4 fixes from Ted Ts'o:
 "A final set of miscellaneous bug fixes for ext4"

* tag 'ext4_for_linus_fixes2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix bogus warning in ext4_update_dx_flag()
  jbd2: fix kernel-doc markups
  ext4: drop fast_commit from /proc/mounts

When doing a lookup in a directory, the afs filesystem uses a bulk
status fetch to speculatively retrieve the statuses of up to 48 other
vnodes found in the same directory and it will then either update extant
inodes or create new ones - effectively doing 'lookup ahead'.

To avoid the possibility of deadlocking itself, however, the filesystem
doesn't lock all of those inodes; rather just the directory inode is
locked (by the VFS).

When the operation completes, afs_inode_init_from_status() or
afs_apply_status() is called, depending on whether the inode already
exists, to commit the new status.

A case exists, however, where the speculative status fetch operation may
straddle a modification operation on one of those vnodes.  What can then
happen is that the speculative bulk status RPC retrieves the old status,
and whilst that is happening, the modification happens - which returns
an updated status, then the modification status is committed, then we
attempt to commit the speculative status.

This results in something like the following being seen in dmesg:

	kAFS: vnode modified {100058:861} 8->9 YFS.InlineBulkStatus

showing that for vnode 861 on volume 100058, we saw YFS.InlineBulkStatus
say that the vnode had data version 8 when we'd already recorded version
9 due to a local modification.  This was causing the cache to be
invalidated for that vnode when it shouldn't have been.  If it happens
on a data file, this might lead to local changes being lost.

Fix this by ignoring speculative status updates if the data version
doesn't match the expected value.

Note that it is possible to get a DV regression if a volume gets
restored from a backup - but we should get a callback break in such a
case that should trigger a recheck anyway.  It might be worth checking
the volume creation time in the volsync info and, if a change is
observed in that (as would happen on a restore), invalidate all caches
associated with the volume.

Fixes: 5cf9dd55 ("afs: Prospectively look up extra files when doing a single lookup")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The calculation of the end page index was incorrect, leading to a
regression of 70% when running stress-ng.

With this fix, we instead see a performance improvement of 3%.

Fixes: e6e88712 ("mm: optimise madvise WILLNEED")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Link: https://lkml.kernel.org/r/20201109134851.29692-1-willy@infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The attr->set() receive a value of u64, but simple_strtoll() is used for
doing the conversion.  It will lead to the error cast if user inputs a
negative value.

Use kstrtoull() instead of simple_strtoll() to convert a string got from
the user to an unsigned value.  The former will return '-EINVAL' if it
gets a negetive value, but the latter can't handle the situation
correctly.  Make 'val' unsigned long long as what kstrtoull() takes,
this will eliminate the compile warning on no 64-bit architectures.

Fixes: f7b88631 ("fs/libfs.c: fix simple_attr_write() on 32bit machines")
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lkml.kernel.org/r/1605341356-11872-1-git-send-email-yangyicong@hisilicon.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Alexander reported a syzkaller / KASAN finding on s390, see below for
complete output.

In do_huge_pmd_anonymous_page(), the pre-allocated pagetable will be
freed in some cases.  In the case of userfaultfd_missing(), this will
happen after calling handle_userfault(), which might have released the
mmap_lock.  Therefore, the following pte_free(vma->vm_mm, pgtable) will
access an unstable vma->vm_mm, which could have been freed or re-used
already.

For all architectures other than s390 this will go w/o any negative
impact, because pte_free() simply frees the page and ignores the
passed-in mm.  The implementation for SPARC32 would also access
mm->page_table_lock for pte_free(), but there is no THP support in
SPARC32, so the buggy code path will not be used there.

For s390, the mm->context.pgtable_list is being used to maintain the 2K
pagetable fragments, and operating on an already freed or even re-used
mm could result in various more or less subtle bugs due to list /
pagetable corruption.

Fix this by calling pte_free() before handle_userfault(), similar to how
it is already done in __do_huge_pmd_anonymous_page() for the WRITE /
non-huge_zero_page case.

Commit 6b251fc9 ("userfaultfd: call handle_userfault() for
userfaultfd_missing() faults") actually introduced both, the
do_huge_pmd_anonymous_page() and also __do_huge_pmd_anonymous_page()
changes wrt to calling handle_userfault(), but only in the latter case
it put the pte_free() before calling handle_userfault().

  BUG: KASAN: use-after-free in do_huge_pmd_anonymous_page+0xcda/0xd90 mm/huge_memory.c:744
  Read of size 8 at addr 00000000962d6988 by task syz-executor.0/9334

  CPU: 1 PID: 9334 Comm: syz-executor.0 Not tainted 5.10.0-rc1-syzkaller-07083-g4c9720875573 #0
  Hardware name: IBM 3906 M04 701 (KVM/Linux)
  Call Trace:
    do_huge_pmd_anonymous_page+0xcda/0xd90 mm/huge_memory.c:744
    create_huge_pmd mm/memory.c:4256 [inline]
    __handle_mm_fault+0xe6e/0x1068 mm/memory.c:4480
    handle_mm_fault+0x288/0x748 mm/memory.c:4607
    do_exception+0x394/0xae0 arch/s390/mm/fault.c:479
    do_dat_exception+0x34/0x80 arch/s390/mm/fault.c:567
    pgm_check_handler+0x1da/0x22c arch/s390/kernel/entry.S:706
    copy_from_user_mvcos arch/s390/lib/uaccess.c:111 [inline]
    raw_copy_from_user+0x3a/0x88 arch/s390/lib/uaccess.c:174
    _copy_from_user+0x48/0xa8 lib/usercopy.c:16
    copy_from_user include/linux/uaccess.h:192 [inline]
    __do_sys_sigaltstack kernel/signal.c:4064 [inline]
    __s390x_sys_sigaltstack+0xc8/0x240 kernel/signal.c:4060
    system_call+0xe0/0x28c arch/s390/kernel/entry.S:415

  Allocated by task 9334:
    slab_alloc_node mm/slub.c:2891 [inline]
    slab_alloc mm/slub.c:2899 [inline]
    kmem_cache_alloc+0x118/0x348 mm/slub.c:2904
    vm_area_dup+0x9c/0x2b8 kernel/fork.c:356
    __split_vma+0xba/0x560 mm/mmap.c:2742
    split_vma+0xca/0x108 mm/mmap.c:2800
    mlock_fixup+0x4ae/0x600 mm/mlock.c:550
    apply_vma_lock_flags+0x2c6/0x398 mm/mlock.c:619
    do_mlock+0x1aa/0x718 mm/mlock.c:711
    __do_sys_mlock2 mm/mlock.c:738 [inline]
    __s390x_sys_mlock2+0x86/0xa8 mm/mlock.c:728
    system_call+0xe0/0x28c arch/s390/kernel/entry.S:415

  Freed by task 9333:
    slab_free mm/slub.c:3142 [inline]
    kmem_cache_free+0x7c/0x4b8 mm/slub.c:3158
    __vma_adjust+0x7b2/0x2508 mm/mmap.c:960
    vma_merge+0x87e/0xce0 mm/mmap.c:1209
    userfaultfd_release+0x412/0x6b8 fs/userfaultfd.c:868
    __fput+0x22c/0x7a8 fs/file_table.c:281
    task_work_run+0x200/0x320 kernel/task_work.c:151
    tracehook_notify_resume include/linux/tracehook.h:188 [inline]
    do_notify_resume+0x100/0x148 arch/s390/kernel/signal.c:538
    system_call+0xe6/0x28c arch/s390/kernel/entry.S:416

  The buggy address belongs to the object at 00000000962d6948 which belongs to the cache vm_area_struct of size 200
  The buggy address is located 64 bytes inside of 200-byte region [00000000962d6948, 00000000962d6a10)
  The buggy address belongs to the page: page:00000000313a09fe refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x962d6 flags: 0x3ffff00000000200(slab)
  raw: 3ffff00000000200 000040000257e080 0000000c0000000c 000000008020ba00
  raw: 0000000000000000 000f001e00000000 ffffffff00000001 0000000096959501
  page dumped because: kasan: bad access detected
  page->mem_cgroup:0000000096959501

  Memory state around the buggy address:
   00000000962d6880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   00000000962d6900: 00 fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb
  >00000000962d6980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                        ^
   00000000962d6a00: fb fb fc fc fc fc fc fc fc fc 00 00 00 00 00 00
   00000000962d6a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  ==================================================================

Fixes: 6b251fc9 ("userfaultfd: call handle_userfault() for userfaultfd_missing() faults")
Reported-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: <stable@vger.kernel.org>	[4.3+]
Link: https://lkml.kernel.org/r/20201110190329.11920-1-gerald.schaefer@linux.ibm.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If we reparent the slab objects to the root memcg, when we free the slab
object, we need to update the per-memcg vmstats to keep it correct for
the root memcg.  Now this at least affects the vmstat of
NR_KERNEL_STACK_KB for !CONFIG_VMAP_STACK when the thread stack size is
smaller than the PAGE_SIZE.

David said:
 "I assume that without this fix that the root memcg's vmstat would
  always be inflated if we reparented"

Fixes: ec9f0238 ("mm: workingset: fix vmstat counters for shadow nodes")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Chris Down <chris@chrisdown.name>
Cc: <stable@vger.kernel.org>	[5.3+]
Link: https://lkml.kernel.org/r/20201110031015.15715-1-songmuchun@bytedance.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Both btrfs and fuse have reported faults caused by seeing a retry entry
instead of the page they were looking for.  This was caused by a missing
check in the iterator.

As can be seen in the below panic log, the accessing 0x402 causes a
panic.  In the xarray.h, 0x402 means RETRY_ENTRY.

  BUG: kernel NULL pointer dereference, address: 0000000000000402
  CPU: 14 PID: 306003 Comm: as Not tainted 5.9.0-1-amd64 #1 Debian 5.9.1-1
  Hardware name: Lenovo ThinkSystem SR665/7D2VCTO1WW, BIOS D8E106Q-1.01 05/30/2020
  RIP: 0010:fuse_readahead+0x152/0x470 [fuse]
  Code: 41 8b 57 18 4c 8d 54 10 ff 4c 89 d6 48 8d 7c 24 10 e8 d2 e3 28 f9 48 85 c0 0f 84 fe 00 00 00 44 89 f2 49 89 04 d4 44 8d 72 01 <48> 8b 10 41 8b 4f 1c 48 c1 ea 10 83 e2 01 80 fa 01 19 d2 81 e2 01
  RSP: 0018:ffffad99ceaebc50 EFLAGS: 00010246
  RAX: 0000000000000402 RBX: 0000000000000001 RCX: 0000000000000002
  RDX: 0000000000000000 RSI: ffff94c5af90bd98 RDI: ffffad99ceaebc60
  RBP: ffff94ddc1749a00 R08: 0000000000000402 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000100 R12: ffff94de6c429ce0
  R13: ffff94de6c4d3700 R14: 0000000000000001 R15: ffffad99ceaebd68
  FS:  00007f228c5c7040(0000) GS:ffff94de8ed80000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000402 CR3: 0000001dbd9b4000 CR4: 0000000000350ee0
  Call Trace:
    read_pages+0x83/0x270
    page_cache_readahead_unbounded+0x197/0x230
    generic_file_buffered_read+0x57a/0xa20
    new_sync_read+0x112/0x1a0
    vfs_read+0xf8/0x180
    ksys_read+0x5f/0xe0
    do_syscall_64+0x33/0x80
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 042124cc ("mm: add new readahead_control API")
Reported-by: David Sterba <dsterba@suse.com>
Reported-by: Wonhyuk Yang <vvghjk1234@gmail.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201103142852.8543-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20201103124349.16722-1-vvghjk1234@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The core-mm has a default __weak implementation of phys_to_target_node()
to mirror the weak definition of memory_add_physaddr_to_nid().  That
symbol is exported for modules.  However, while the export in
mm/memory_hotplug.c exported the symbol in the configuration cases of:

	CONFIG_NUMA_KEEP_MEMINFO=y
	CONFIG_MEMORY_HOTPLUG=y

...and:

	CONFIG_NUMA_KEEP_MEMINFO=n
	CONFIG_MEMORY_HOTPLUG=y

...it failed to export the symbol in the case of:

	CONFIG_NUMA_KEEP_MEMINFO=y
	CONFIG_MEMORY_HOTPLUG=n

Not only is that broken, but Christoph points out that the kernel should
not be exporting any __weak symbol, which means that
memory_add_physaddr_to_nid() example that phys_to_target_node() copied
is broken too.

Rework the definition of phys_to_target_node() and
memory_add_physaddr_to_nid() to not require weak symbols.  Move to the
common arch override design-pattern of an asm header defining a symbol
to replace the default implementation.

The only common header that all memory_add_physaddr_to_nid() producing
architectures implement is asm/sparsemem.h.  In fact, powerpc already
defines its memory_add_physaddr_to_nid() helper in sparsemem.h.
Double-down on that observation and define phys_to_target_node() where
necessary in asm/sparsemem.h.  An alternate consideration that was
discarded was to put this override in asm/numa.h, but that entangles
with the definition of MAX_NUMNODES relative to the inclusion of
linux/nodemask.h, and requires powerpc to grow a new header.

The dependency on NUMA_KEEP_MEMINFO for DEV_DAX_HMEM_DEVICES is invalid
now that the symbol is properly exported / stubbed in all combinations
of CONFIG_NUMA_KEEP_MEMINFO and CONFIG_MEMORY_HOTPLUG.

[dan.j.williams@intel.com: v4]
  Link: https://lkml.kernel.org/r/160461461867.1505359.5301571728749534585.stgit@dwillia2-desk3.amr.corp.intel.com
[dan.j.williams@intel.com: powerpc: fix create_section_mapping compile warning]
  Link: https://lkml.kernel.org/r/160558386174.2948926.2740149041249041764.stgit@dwillia2-desk3.amr.corp.intel.com

Fixes: a035b6bf ("mm/memory_hotplug: introduce default phys_to_target_node() implementation")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lkml.kernel.org/r/160447639846.1133764.7044090803980177548.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bpftrace parses the kernel headers and uses Clang under the hood.

Remove the version check when __BPF_TRACING__ is defined (as bpftrace
does) so that this tool can continue to parse kernel headers, even with
older clang sources.

Fixes: commit 1f7a44f6 ("compiler-clang: add build check for clang 10.0.1")
Reported-by: Chen Yu <yu.chen.surf@gmail.com>
Reported-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://lkml.kernel.org/r/20201104191052.390657-1-ndesaulniers@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The early return in process_madvise() will produce a memory leak.

Fix it.

Fixes: ecb8ac8b ("mm/madvise: introduce process_madvise() syscall: an external memory hinting API")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20201116155132.GA3805951@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull xfs fixes from Darrick Wong:
 "The critical fixes are for a crash that someone reported in the xattr
  code on 32-bit arm last week; and a revert of the rmap key comparison
  change from last week as it was totally wrong. I need a vacation. :(

  Summary:

   - Fix various deficiencies in online fsck's metadata checking code

   - Fix an integer casting bug in the xattr code on 32-bit systems

   - Fix a hang in an inode walk when the inode index is corrupt

   - Fix error codes being dropped when initializing per-AG structures

   - Fix nowait directio writes that partially succeed but return EAGAIN

   - Revert last week's rmap comparison patch because it was wrong"

* tag 'xfs-5.10-fixes-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: revert "xfs: fix rmap key and record comparison functions"
  xfs: don't allow NOWAIT DIO across extent boundaries
  xfs: return corresponding errcode if xfs_initialize_perag() fail
  xfs: ensure inobt record walks always make forward progress
  xfs: fix forkoff miscalculation related to XFS_LITINO(mp)
  xfs: directory scrub should check the null bestfree entries too
  xfs: strengthen rmap record flags checking
  xfs: fix the minrecs logic when dealing with inode root child blocks

Pull fanotify fix from Jan Kara:
 "A single fanotify fix from Amir"

* tag 'fsnotify_for_v5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  fanotify: fix logic of reporting name info with watched parent

Pull seccomp fixes from Kees Cook:
 "This gets the seccomp selftests running again on powerpc and sh, and
  fixes an audit reporting oversight noticed in both seccomp and ptrace.

   - Fix typos in seccomp selftests on powerpc and sh (Kees Cook)

   - Fix PF_SUPERPRIV audit marking in seccomp and ptrace (Mickaël
     Salaün)"

* tag 'seccomp-v5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  selftests/seccomp: sh: Fix register names
  selftests/seccomp: powerpc: Fix typo in macro variable name
  seccomp: Set PF_SUPERPRIV when checking capability
  ptrace: Set PF_SUPERPRIV when checking capability