Pull io_uring fixes from Jens Axboe:
 "Here are a few io_uring fixes that should go into this release. This
  contains:

   - Removal of (now) unused io_wq_flush() and associated flag (Pavel)

   - Fix cancelation lockup with linked timeouts (Pavel)

   - Fix for potential use-after-free when freeing percpu ref for fixed
     file sets

   - io-wq cancelation fixups (Pavel)"

* tag 'io_uring-5.6-2020-03-07' of git://git.kernel.dk/linux-block:
  io_uring: fix lockup with timeouts
  io_uring: free fixed_file_data after RCU grace period
  io-wq: remove io_wq_flush and IO_WQ_WORK_INTERNAL
  io-wq: fix IO_WQ_WORK_NO_CANCEL cancellation

Pull block fixes from Jens Axboe:
 "Here are a few fixes that should go into this release. This contains:

   - Revert of a bad bcache patch from this merge window

   - Removed unused function (Daniel)

   - Fixup for the blktrace fix from Jan from this release (Cengiz)

   - Fix of deeper level bfqq overwrite in BFQ (Carlo)"

* tag 'block-5.6-2020-03-07' of git://git.kernel.dk/linux-block:
  block, bfq: fix overwrite of bfq_group pointer in bfq_find_set_group()
  blktrace: fix dereference after null check
  Revert "bcache: ignore pending signals when creating gc and allocator thread"
  block: Remove used kblockd_schedule_work_on()

Pull media fixes from Mauro Carvalho Chehab:

 - a fix for the media controller links in both hantro driver and in
   v4l2-mem2mem core

 - some fixes for the pulse8-cec driver

 - vicodec: handle alpha channel for RGB32 formats, as it may be used

 - mc-entity.c: fix handling of pad flags

* tag 'media/v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  media: hantro: Fix broken media controller links
  media: mc-entity.c: use & to check pad flags, not ==
  media: v4l2-mem2mem.c: fix broken links
  media: vicodec: process all 4 components for RGB32 formats
  media: pulse8-cec: close serio in disconnect, not adap_free
  media: pulse8-cec: INIT_DELAYED_WORK was called too late

There is a recipe to deadlock the kernel: submit a timeout sqe with a
linked_timeout (e.g.  test_single_link_timeout_ception() from liburing),
and SIGKILL the process.

Then, io_kill_timeouts() takes @ctx->completion_lock, but the timeout
isn't flagged with REQ_F_COMP_LOCKED, and will try to double grab it
during io_put_free() to cancel the linked timeout. Probably, the same
can happen with another io_kill_timeout() call site, that is
io_commit_cqring().
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull s390 fixes from Vasily Gorbik:

 - Fix panic in gup_fast on large pud by providing an implementation of
   pud_write. This has been overlooked during migration to common gup
   code.

 - Fix unexpected write combining on PCI stores.

* tag 's390-5.6-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/pci: Fix unexpected write combine on resource
  s390/mm: fix panic in gup_fast on large pud

Pull powerpc fixes from Michael Ellerman:
 "Some more powerpc fixes for 5.6:

   - One fix for a recent regression to our breakpoint/watchpoint code.

   - Another fix for our KUAP support, this time a missing annotation in
     a rarely used path in signal handling.

   - A fix for our handling of a CPU feature that effects the PMU, when
     booting guests in some configurations.

   - A minor fix to our linker script to explicitly include the .BTF
     section.

  Thanks to: Christophe Leroy, Desnes A. Nunes do Rosario, Leonardo
  Bras, Naveen N. Rao, Ravi Bangoria, Stefan Berger"

* tag 'powerpc-5.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/mm: Fix missing KUAP disable in flush_coherent_icache()
  powerpc: fix hardware PMU exception bug on PowerVM compatibility mode systems
  powerpc: Include .BTF section
  powerpc/watchpoint: Don't call dar_within_range() for Book3S

Pull xen fixes from Juergen Gross:
 "Four fixes and a small cleanup patch:

   - two fixes by Dongli Zhang fixing races in the xenbus driver

   - two fixes by me fixing issues introduced in 5.6

   - a small cleanup by Gustavo Silva replacing a zero-length array with
     a flexible-array"

* tag 'for-linus-5.6b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/blkfront: fix ring info addressing
  xen/xenbus: fix locking
  xenbus: req->err should be updated before req->state
  xenbus: req->body should be updated before req->state
  xen: Replace zero-length array with flexible-array member

Pull thread fixes from Christian Brauner:
 "Here are a few hopefully uncontroversial fixes:

   - Use RCU_INIT_POINTER() when initializing rcu protected members in
     task_struct to fix sparse warnings.

   - Add pidfd_fdinfo_test binary to .gitignore file"

* tag 'for-linus-2020-03-07' of gitolite.kernel.org:pub/scm/linux/kernel/git/brauner/linux:
  selftests: pidfd: Add pidfd_fdinfo_test in .gitignore
  exit: Fix Sparse errors and warnings
  fork: Use RCU_INIT_POINTER() instead of rcu_access_pointer()

Pull sound fixes from Takashi Iwai:
 "The regular "bump-in-the-middle" updates, containing mostly ASoC-
  related fixes at this time. All changes are reasonably small.

  A few entries are for ASoC and ALSA core parts (DAPM, PCM, topology)
  for followups of the recent changes and potential buffer overflow by
  snprintf(), while the rest are (both new and old) device-specific
  fixes for Intel, meson, tas2562, rt1015, as well as the usual HD-audio
  quirks"

* tag 'sound-5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (25 commits)
  ALSA: sgio2audio: Remove usage of dropped hw_params/hw_free functions
  ALSA: hda/realtek - Enable the headset of ASUS B9450FA with ALC294
  ALSA: hda/realtek - Fix silent output on Gigabyte X570 Aorus Master
  ALSA: hda/realtek - Add Headset Button supported for ThinkPad X1
  ALSA: hda/realtek - Add Headset Mic supported
  ASoC: wm8741: Fix typo in Kconfig prompt
  ASoC: stm32: sai: manage rebind issue
  ASoC: SOF: Fix snd_sof_ipc_stream_posn()
  ASoC: rt1015: modify pre-divider for sysclk
  ASoC: rt1015: add operation callback function for rt1015_dai[]
  ASoC: soc-component: tidyup snd_soc_pcm_component_sync_stop()
  ASoC: dapm: Correct DAPM handling of active widgets during shutdown
  ASoC: tas2562: Fix sample rate error message
  ASoC: Intel: Skylake: Fix available clock counter incrementation
  ASoC: soc-pcm/soc-compress: don't use snd_soc_dapm_stream_stop()
  ASoC: meson: g12a: add tohdmitx reset
  ASoC: pcm512x: Fix unbalanced regulator enable call in probe error path
  ASoC: soc-core: fix for_rtd_codec_dai_rollback() macro
  ASoC: topology: Fix memleak in soc_tplg_manifest_load()
  ASoC: topology: Fix memleak in soc_tplg_link_elems_load()
  ...

Merge tag 'asoc-fix-v5.6-rc4' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

ASoC: Fixes for v5.6

More fixes that have arrived since the merge window, spread out all
over.  There's a few things like the operation callback addition for
rt1015 and the meson reset addition which add small new bits of
functionality to fix non-working systems, they're all very small and for
parts of newly added functionality.

Merge tag 'linux-kselftest-5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest update from Shuah Khan:
 "This consists of a cleanup patch to undo changes to global .gitignore
  that added selftests/lkdtm objects and add them to a local
  selftests/lkdtm/.gitignore.

  Summary of Linus's comments on local vs. global gitignore scope:

   - Keep local gitignore patterns in local files.

   - Put only global gitignore patterns in the top-level gitignore file.

  Local scope keeps things much better separated. It also incidentally
  means that if a directory gets renamed, the gitignore file continues
  to work unless in the case of renaming the actual files themselves
  that are named in the gitignore"

* tag 'linux-kselftest-5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftest/lkdtm: Use local .gitignore

Pull RISC-V fixes from Palmer Dabbelt:
 "This contains a handful of fixes that I would like to target for 5.6:

   - A pair of fixes to module loading, which we hope solve the last of
     the issues with module text being loaded too sparsely for our call
     relocations.

   - A Kconfig fix that disallows selecting memory models not supported
     by NOMMU.

   - A series of Kconfig updates to ease selecting the drivers necessary
     to run on QEMU's virt platform.

   - DTS updates for SiFive's HiFive Unleashed.

   - A fix to our seccomp support that avoids mangling restartable
     syscalls"

* tag 'riscv-for-linus-5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: fix seccomp reject syscall code path
  riscv: dts: Add GPIO reboot method to HiFive Unleashed DTS file
  RISC-V: Select Goldfish RTC driver for QEMU virt machine
  RISC-V: Select SYSCON Reboot and Poweroff for QEMU virt machine
  RISC-V: Enable QEMU virt machine support in defconfigs
  RISC-V: Add kconfig option for QEMU virt machine
  riscv: Fix range looking for kernel image memblock
  riscv: Force flat memory model with no-mmu
  riscv: Change code model of module to medany to improve data accessing
  riscv: avoid the PIC offset of static percpu data in module beyond 2G limits

This makes the script more convenient to run.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull devicetree fixes from Rob Herring:
 "Another batch of DT fixes. I think this should be the last of it, but
  sending pull requests seems to cause people to send more fixes.

  Summary:

   - Fixes for warnings introduced by hierarchical PSCI binding changes

   - Fixes for broken doc references due to DT schema conversions

   - Several grammar and typo fixes

   - Fix a bunch of dtc warnings in examples"

* tag 'devicetree-fixes-for-5.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  dt-bindings: arm: Fixup the DT bindings for hierarchical PSCI states
  dt-bindings: power: Extend nodename pattern for power-domain providers
  MAINTAINERS: update ALLWINNER CPUFREQ DRIVER entry
  dt-bindings: bus: Drop empty compatible string in example
  dt-bindings: power: Convert domain-idle-states bindings to json-schema
  dt-bindings: arm: Fix cpu compatibles in the hierarchical example for PSCI
  dt-bindings: arm: Correct links to idle states definitions
  dt-bindings: mfd: Fix typo in file name of twl-familly.txt
  dt-bindings: mfd: tps65910: Improve grammar
  dt-bindings: mfd: zii,rave-sp: Fix a typo ("onborad")
  dt-bindings: arm: fsl: fix APF6Dev compatible
  dt-bindings: Fix dtc warnings in examples
  docs: dt: fix several broken doc references
  docs: dt: fix several broken references due to renames
  MAINTAINERS: clean up PCIE DRIVER FOR CAVIUM THUNDERX

Pull vgacon fix from Daniel Vetter:
 "One vgacon input check for stable"

* tag 'drm-fixes-2020-03-06-1' of git://anongit.freedesktop.org/drm/drm:
  vgacon: Fix a UAF in vgacon_invert_region

Pull btrfs fix from David Sterba:
 "One fixup for DIO when in use with the new checksums, a missed case
  where the checksum size was still assuming u32"

* tag 'for-5.6-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix RAID direct I/O reads with alternate csums

Pull file locking fixes from Jeff Layton:
 "Just a couple of late-breaking patches for the file locking code. The
  second patch (from yangerkun) fixes a rather nasty looking potential
  use-after-free that should go to stable.

  The other patch could technically wait for 5.7, but it's fairly
  innocuous so I figured we might as well take it"

* tag 'filelock-v5.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
  locks: fix a potential use-after-free problem when wakeup a waiter
  fcntl: Distribute switch variables for initialization

Pull spi fixes from Mark Brown:
 "A selection of small fixes, mostly for drivers, that have arrived
  since the merge window. None of them are earth shattering in
  themselves but all useful for affected systems"

* tag 'spi-fix-v5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: spi_register_controller(): free bus id on error paths
  spi: bcm63xx-hsspi: Really keep pll clk enabled
  spi: atmel-quadspi: fix possible MMIO window size overrun
  spi/zynqmp: remove entry that causes a cs glitch
  spi: pxa2xx: Add CS control clock quirk
  spi: spidev: Fix CS polarity if GPIO descriptors are used
  spi: qup: call spi_qup_pm_resume_runtime before suspending
  spi: spi-omap2-mcspi: Support probe deferral for DMA channels
  spi: spi-omap2-mcspi: Handle DMA size restriction on AM65x

Merge tag 'regulator-fix-v5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator

Pull regulator fixes from Mark Brown:
 "A couple of small fixes, one for a minor issue in the stm32-vrefbuf
  driver and a documentation fix in the Qualcomm code"

* tag 'regulator-fix-v5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: stm32-vrefbuf: fix a possible overshoot when re-enabling
  regulator: qcom_spmi: Fix docs for PM8004

Merge tag 'hwmon-for-v5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:
 "Fix an error return in the adt7462 driver, bad voltage limits reported
  by the xdpe12284 driver, and a broken documentation reference in the
  adm1177 driver documentation"

* tag 'hwmon-for-v5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (adt7462) Fix an error return in ADT7462_REG_VOLT()
  hwmon: (pmbus/xdpe12284) Add callback for vout limits conversion
  docs: adm1177: fix a broken reference

Pull arm64 fixes from Will Deacon:
 "Here are another three arm64 fixes for 5.6, all pretty minor. Main
  thing is fixing a silly bug in the fsl_imx8_ddr PMU driver where we
  would zero the counters when disabling them.

   - Fix misreporting of ASID limit when KPTI is enabled

   - Fix busted NULL pointer checks for GICC structure in ACPI PMU code

   - Avoid nobbling the "fsl_imx8_ddr" PMU counters when disabling them"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: context: Fix ASID limit in boot messages
  drivers/perf: arm_pmu_acpi: Fix incorrect checking of gicc pointer
  drivers/perf: fsl_imx8_ddr: Correct the CLEAR bit definition

When syzkaller tests, there is a UAF:
  BUG: KASan: use after free in vgacon_invert_region+0x9d/0x110 at addr
    ffff880000100000
  Read of size 2 by task syz-executor.1/16489
  page:ffffea0000004000 count:0 mapcount:-127 mapping:          (null)
  index:0x0
  page flags: 0xfffff00000000()
  page dumped because: kasan: bad access detected
  CPU: 1 PID: 16489 Comm: syz-executor.1 Not tainted
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
  rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
  Call Trace:
    [<ffffffffb119f309>] dump_stack+0x1e/0x20
    [<ffffffffb04af957>] kasan_report+0x577/0x950
    [<ffffffffb04ae652>] __asan_load2+0x62/0x80
    [<ffffffffb090f26d>] vgacon_invert_region+0x9d/0x110
    [<ffffffffb0a39d95>] invert_screen+0xe5/0x470
    [<ffffffffb0a21dcb>] set_selection+0x44b/0x12f0
    [<ffffffffb0a3bfae>] tioclinux+0xee/0x490
    [<ffffffffb0a1d114>] vt_ioctl+0xff4/0x2670
    [<ffffffffb0a0089a>] tty_ioctl+0x46a/0x1a10
    [<ffffffffb052db3d>] do_vfs_ioctl+0x5bd/0xc40
    [<ffffffffb052e2f2>] SyS_ioctl+0x132/0x170
    [<ffffffffb11c9b1b>] system_call_fastpath+0x22/0x27
    Memory state around the buggy address:
     ffff8800000fff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00
     00 00
     ffff8800000fff80: 00 00 00 00 00 00 00 00 00 00 00 00 00
     00 00 00
    >ffff880000100000: ff ff ff ff ff ff ff ff ff ff ff ff ff
     ff ff ff

It can be reproduce in the linux mainline by the program:
  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <sys/ioctl.h>
  #include <linux/vt.h>

  struct tiocl_selection {
    unsigned short xs;      /* X start */
    unsigned short ys;      /* Y start */
    unsigned short xe;      /* X end */
    unsigned short ye;      /* Y end */
    unsigned short sel_mode; /* selection mode */
  };

  #define TIOCL_SETSEL    2
  struct tiocl {
    unsigned char type;
    unsigned char pad;
    struct tiocl_selection sel;
  };

  int main()
  {
    int fd = 0;
    const char *dev = "/dev/char/4:1";

    struct vt_consize v = {0};
    struct tiocl tioc = {0};

    fd = open(dev, O_RDWR, 0);

    v.v_rows = 3346;
    ioctl(fd, VT_RESIZEX, &v);

    tioc.type = TIOCL_SETSEL;
    ioctl(fd, TIOCLINUX, &tioc);

    return 0;
  }

When resize the screen, update the 'vc->vc_size_row' to the new_row_size,
but when 'set_origin' in 'vgacon_set_origin', vgacon use 'vga_vram_base'
for 'vc_origin' and 'vc_visible_origin', not 'vc_screenbuf'. It maybe
smaller than 'vc_screenbuf'. When TIOCLINUX, use the new_row_size to calc
the offset, it maybe larger than the vga_vram_size in vgacon driver, then
bad access.
Also, if set an larger screenbuf firstly, then set an more larger
screenbuf, when copy old_origin to new_origin, a bad access may happen.

So, If the screen size larger than vga_vram, resize screen should be
failed. This alse fix CVE-2020-8649 and CVE-2020-8647.

Linus pointed out that overflow checking seems absent. We're saved by
the existing bounds checks in vc_do_resize() with rather strict
limits:

	if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
		return -EINVAL;

Fixes: 0aec4867 ("[PATCH] SVGATextMode fix")
Reference: CVE-2020-8647 and CVE-2020-8649
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
[danvet: augment commit message to point out overflow safety]
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200304022429.37738-1-zhangxiaoxu5@huawei.com

The hierarchical topology with power-domain should be described through
child nodes, rather than as currently described in the PSCI root node. Fix
this by adding a patternProperties with a corresponding reference to the
power-domain DT binding.

Additionally, update the example to conform to the new pattern, but also to
the adjusted domain-idle-state DT binding.

Fixes: a3f048b5 ("dt: psci: Update DT bindings to support hierarchical PSCI states")
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[robh: Add missing allOf, tweak power-domain node name]
Signed-off-by: Rob Herring <robh@kernel.org>

The existing binding requires the nodename to have a '@', which is a bit
limiting for the wider use case. Therefore, let's extend the pattern to
allow either '@' or '-'.

Fixes: a3f048b5 ("dt: psci: Update DT bindings to support hierarchical PSCI states")
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[robh: drop example change]
Signed-off-by: Rob Herring <robh@kernel.org>

The percpu refcount protects this structure, and we can have an atomic
switch in progress when exiting. This makes it unsafe to just free the
struct normally, and can trigger the following KASAN warning:

BUG: KASAN: use-after-free in percpu_ref_switch_to_atomic_rcu+0xfa/0x1b0
Read of size 1 at addr ffff888181a19a30 by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc4+ #5747
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
 <IRQ>
 dump_stack+0x76/0xa0
 print_address_description.constprop.0+0x3b/0x60
 ? percpu_ref_switch_to_atomic_rcu+0xfa/0x1b0
 ? percpu_ref_switch_to_atomic_rcu+0xfa/0x1b0
 __kasan_report.cold+0x1a/0x3d
 ? percpu_ref_switch_to_atomic_rcu+0xfa/0x1b0
 percpu_ref_switch_to_atomic_rcu+0xfa/0x1b0
 rcu_core+0x370/0x830
 ? percpu_ref_exit+0x50/0x50
 ? rcu_note_context_switch+0x7b0/0x7b0
 ? run_rebalance_domains+0x11d/0x140
 __do_softirq+0x10a/0x3e9
 irq_exit+0xd5/0xe0
 smp_apic_timer_interrupt+0x86/0x200
 apic_timer_interrupt+0xf/0x20
 </IRQ>
RIP: 0010:default_idle+0x26/0x1f0

Fix this by punting the final exit and free of the struct to RCU, then
we know that it's safe to do so. Jann suggested the approach of using a
double rcu callback to achieve this. It's important that we do a nested
call_rcu() callback, as otherwise the free could be ordered before the
atomic switch, even if the latter was already queued.

Reported-by: syzbot+e017e49c39ab484ac87a@syzkaller.appspotmail.com
Suggested-by: Jann Horn <jannh@google.com>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

'16306a61 ("fs/locks: always delete_block after waiting.")' add the
logic to check waiter->fl_blocker without blocked_lock_lock. And it will
trigger a UAF when we try to wakeup some waiter：

Thread 1 has create a write flock a on file, and now thread 2 try to
unlock and delete flock a, thread 3 try to add flock b on the same file.

Thread2                         Thread3
                                flock syscall(create flock b)
	                        ...flock_lock_inode_wait
				    flock_lock_inode(will insert
				    our fl_blocked_member list
				    to flock a's fl_blocked_requests)
				   sleep
flock syscall(unlock)
...flock_lock_inode_wait
    locks_delete_lock_ctx
    ...__locks_wake_up_blocks
        __locks_delete_blocks(
	b->fl_blocker = NULL)
	...
                                   break by a signal
				   locks_delete_block
				    b->fl_blocker == NULL &&
				    list_empty(&b->fl_blocked_requests)
	                            success, return directly
				 locks_free_lock b
	wake_up(&b->fl_waiter)
	trigger UAF

Fix it by remove this logic, and this patch may also fix CVE-2019-19769.

Cc: stable@vger.kernel.org
Fixes: 16306a61 ("fs/locks: always delete_block after waiting.")
Signed-off-by: yangerkun <yangerkun@huawei.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>

The bfq_find_set_group() function takes as input a blkcg (which represents
a cgroup) and retrieves the corresponding bfq_group, then it updates the
bfq internal group hierarchy (see comments inside the function for why
this is needed) and finally it returns the bfq_group.
In the hierarchy update cycle, the pointer holding the correct bfq_group
that has to be returned is mistakenly used to traverse the hierarchy
bottom to top, meaning that in each iteration it gets overwritten with the
parent of the current group. Since the update cycle stops at root's
children (depth = 2), the overwrite becomes a problem only if the blkcg
describes a cgroup at a hierarchy level deeper than that (depth > 2). In
this case the root's child that happens to be also an ancestor of the
correct bfq_group is returned. The main consequence is that processes
contained in a cgroup at depth greater than 2 are wrongly placed in the
group described above by BFQ.

This commits fixes this problem by using a different bfq_group pointer in
the update cycle in order to avoid the overwrite of the variable holding
the original group reference.
Reported-by: Kwon Je Oh <kwonje.oh2@gmail.com>
Signed-off-by: Carlo Nonato <carlo.nonato95@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Merge misc fixes from Andrew Morton:
 "7 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  arch/Kconfig: update HAVE_RELIABLE_STACKTRACE description
  mm, hotplug: fix page online with DEBUG_PAGEALLOC compiled but not enabled
  mm/z3fold.c: do not include rwlock.h directly
  fat: fix uninit-memory access for partial initialized inode
  mm: avoid data corruption on CoW fault into PFN-mapped VMA
  mm: fix possible PMD dirty bit lost in set_pmd_migration_entry()
  mm, numa: fix bad pmd by atomically check for pmd_trans_huge when marking page tables prot_numa

save_stack_trace_tsk_reliable() is not the only function providing the
reliable stack traces anymore.  Architecture might define ARCH_STACKWALK
which provides a newer stack walking interface and has
arch_stack_walk_reliable() function.  Update the description accordingly.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: http://lkml.kernel.org/r/20200120154042.9934-1-mbenes@suse.czSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit cd02cf1a ("mm/hotplug: fix an imbalance with DEBUG_PAGEALLOC")
fixed memory hotplug with debug_pagealloc enabled, where onlining a page
goes through page freeing, which removes the direct mapping.  Some arches
don't like when the page is not mapped in the first place, so
generic_online_page() maps it first.  This is somewhat wasteful, but
better than special casing page freeing fast paths.

The commit however missed that DEBUG_PAGEALLOC configured doesn't mean
it's actually enabled.  One has to test debug_pagealloc_enabled() since
031bc574 ("mm/debug-pagealloc: make debug-pagealloc boottime
configurable"), or alternatively debug_pagealloc_enabled_static() since
8e57f8ac ("mm, debug_pagealloc: don't rely on static keys too early"),
but this is not done.

As a result, a s390 kernel with DEBUG_PAGEALLOC configured but not enabled
will crash:

Unable to handle kernel pointer dereference in virtual kernel address space
Failing address: 0000000000000000 TEID: 0000000000000483
Fault in home space mode while using kernel ASCE.
AS:0000001ece13400b R2:000003fff7fd000b R3:000003fff7fcc007 S:000003fff7fd7000 P:000000000000013d
Oops: 0004 ilc:2 [#1] SMP
CPU: 1 PID: 26015 Comm: chmem Kdump: loaded Tainted: GX 5.3.18-5-default #1 SLE15-SP2 (unreleased)
Krnl PSW : 0704e00180000000 0000001ecd281b9e (__kernel_map_pages+0x166/0x188)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
Krnl GPRS: 0000000000000000 0000000000000800 0000400b00000000 0000000000000100
0000000000000001 0000000000000000 0000000000000002 0000000000000100
0000001ece139230 0000001ecdd98d40 0000400b00000100 0000000000000000
000003ffa17e4000 001fffe0114f7d08 0000001ecd4d93ea 001fffe0114f7b20
Krnl Code: 0000001ecd281b8e: ec17ffff00d8 ahik %r1,%r7,-1
0000001ecd281b94: ec111dbc0355 risbg %r1,%r1,29,188,3
>0000001ecd281b9e: 94fb5006 ni 6(%r5),251
0000001ecd281ba2: 41505008 la %r5,8(%r5)
0000001ecd281ba6: ec51fffc6064 cgrj %r5,%r1,6,1ecd281b9e
0000001ecd281bac: 1a07 ar %r0,%r7
0000001ecd281bae: ec03ff584076 crj %r0,%r3,4,1ecd281a5e
Call Trace:
[<0000001ecd281b9e>] __kernel_map_pages+0x166/0x188
[<0000001ecd4d9516>] online_pages_range+0xf6/0x128
[<0000001ecd2a8186>] walk_system_ram_range+0x7e/0xd8
[<0000001ecda28aae>] online_pages+0x2fe/0x3f0
[<0000001ecd7d02a6>] memory_subsys_online+0x8e/0xc0
[<0000001ecd7add42>] device_online+0x5a/0xc8
[<0000001ecd7d0430>] state_store+0x88/0x118
[<0000001ecd5b9f62>] kernfs_fop_write+0xc2/0x200
[<0000001ecd5064b6>] vfs_write+0x176/0x1e0
[<0000001ecd50676a>] ksys_write+0xa2/0x100
[<0000001ecda315d4>] system_call+0xd8/0x2c8

Fix this by checking debug_pagealloc_enabled_static() before calling
kernel_map_pages(). Backports for kernel before 5.5 should use
debug_pagealloc_enabled() instead. Also add comments.

Fixes: cd02cf1a ("mm/hotplug: fix an imbalance with DEBUG_PAGEALLOC")
Reported-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: <stable@vger.kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Qian Cai <cai@lca.pw>
Link: http://lkml.kernel.org/r/20200224094651.18257-1-vbabka@suse.czSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rwlock.h should not be included directly. Instead linux/splinlock.h
should be included. One thing it does is to break the RT build.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200224133631.1510569-1-bigeasy@linutronix.deSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When get an error in the middle of reading an inode, some fields in the
inode might be still not initialized.  And then the evict_inode path may
access those fields via iput().

To fix, this makes sure that inode fields are initialized.

Reported-by: syzbot+9d82b8de2992579da5d0@syzkaller.appspotmail.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/871rqnreqx.fsf@mail.parknet.co.jpSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Jeff Moyer has reported that one of xfstests triggers a warning when run
on DAX-enabled filesystem:

	WARNING: CPU: 76 PID: 51024 at mm/memory.c:2317 wp_page_copy+0xc40/0xd50
	...
	wp_page_copy+0x98c/0xd50 (unreliable)
	do_wp_page+0xd8/0xad0
	__handle_mm_fault+0x748/0x1b90
	handle_mm_fault+0x120/0x1f0
	__do_page_fault+0x240/0xd70
	do_page_fault+0x38/0xd0
	handle_page_fault+0x10/0x30

The warning happens on failed __copy_from_user_inatomic() which tries to
copy data into a CoW page.

This happens because of race between MADV_DONTNEED and CoW page fault:

	CPU0					CPU1
 handle_mm_fault()
   do_wp_page()
     wp_page_copy()
       do_wp_page()
					madvise(MADV_DONTNEED)
					  zap_page_range()
					    zap_pte_range()
					      ptep_get_and_clear_full()
					      <TLB flush>
	 __copy_from_user_inatomic()
	 sees empty PTE and fails
	 WARN_ON_ONCE(1)
	 clear_page()

The solution is to re-try __copy_from_user_inatomic() under PTL after
checking that PTE is matches the orig_pte.

The second copy attempt can still fail, like due to non-readable PTE, but
there's nothing reasonable we can do about, except clearing the CoW page.
Reported-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Jeff Moyer <jmoyer@redhat.com>
Cc: <stable@vger.kernel.org>
Cc: Justin He <Justin.He@arm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Link: http://lkml.kernel.org/r/20200218154151.13349-1-kirill.shutemov@linux.intel.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In set_pmd_migration_entry(), pmdp_invalidate() is used to change PMD
atomically.  But the PMD is read before that with an ordinary memory
reading.  If the THP (transparent huge page) is written between the PMD
reading and pmdp_invalidate(), the PMD dirty bit may be lost, and cause
data corruption.  The race window is quite small, but still possible in
theory, so need to be fixed.

The race is fixed via using the return value of pmdp_invalidate() to get
the original content of PMD, which is a read/modify/write atomic
operation.  So no THP writing can occur in between.

The race has been introduced when the THP migration support is added in
the commit 616b8371 ("mm: thp: enable thp migration in generic path").
But this fix depends on the commit d52605d7 ("mm: do not lose dirty
and accessed bits in pmdp_invalidate()").  So it's easy to be backported
after v4.16.  But the race window is really small, so it may be fine not
to backport the fix at all.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Link: http://lkml.kernel.org/r/20200220075220.2327056-1-ying.huang@intel.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

: A user reported a bug against a distribution kernel while running a
: proprietary workload described as "memory intensive that is not swapping"
: that is expected to apply to mainline kernels.  The workload is
: read/write/modifying ranges of memory and checking the contents.  They
: reported that within a few hours that a bad PMD would be reported followed
: by a memory corruption where expected data was all zeros.  A partial
: report of the bad PMD looked like
:
:   [ 5195.338482] ../mm/pgtable-generic.c:33: bad pmd ffff8888157ba008(000002e0396009e2)
:   [ 5195.341184] ------------[ cut here ]------------
:   [ 5195.356880] kernel BUG at ../mm/pgtable-generic.c:35!
:   ....
:   [ 5195.410033] Call Trace:
:   [ 5195.410471]  [<ffffffff811bc75d>] change_protection_range+0x7dd/0x930
:   [ 5195.410716]  [<ffffffff811d4be8>] change_prot_numa+0x18/0x30
:   [ 5195.410918]  [<ffffffff810adefe>] task_numa_work+0x1fe/0x310
:   [ 5195.411200]  [<ffffffff81098322>] task_work_run+0x72/0x90
:   [ 5195.411246]  [<ffffffff81077139>] exit_to_usermode_loop+0x91/0xc2
:   [ 5195.411494]  [<ffffffff81003a51>] prepare_exit_to_usermode+0x31/0x40
:   [ 5195.411739]  [<ffffffff815e56af>] retint_user+0x8/0x10
:
: Decoding revealed that the PMD was a valid prot_numa PMD and the bad PMD
: was a false detection.  The bug does not trigger if automatic NUMA
: balancing or transparent huge pages is disabled.
:
: The bug is due a race in change_pmd_range between a pmd_trans_huge and
: pmd_nond_or_clear_bad check without any locks held.  During the
: pmd_trans_huge check, a parallel protection update under lock can have
: cleared the PMD and filled it with a prot_numa entry between the transhuge
: check and the pmd_none_or_clear_bad check.
:
: While this could be fixed with heavy locking, it's only necessary to make
: a copy of the PMD on the stack during change_pmd_range and avoid races.  A
: new helper is created for this as the check if quite subtle and the
: existing similar helpful is not suitable.  This passed 154 hours of
: testing (usually triggers between 20 minutes and 24 hours) without
: detecting bad PMDs or corruption.  A basic test of an autonuma-intensive
: workload showed no significant change in behaviour.

Although Mel withdrew the patch on the face of LKML comment
https://lkml.org/lkml/2017/4/10/922 the race window aforementioned is
still open, and we have reports of Linpack test reporting bad residuals
after the bad PMD warning is observed.  In addition to that, bad
rss-counter and non-zero pgtables assertions are triggered on mm teardown
for the task hitting the bad PMD.

 host kernel: mm/pgtable-generic.c:40: bad pmd 00000000b3152f68(8000000d2d2008e7)
 ....
 host kernel: BUG: Bad rss-counter state mm:00000000b583043d idx:1 val:512
 host kernel: BUG: non-zero pgtables_bytes on freeing mm: 4096

The issue is observed on a v4.18-based distribution kernel, but the race
window is expected to be applicable to mainline kernels, as well.

[akpm@linux-foundation.org: fix comment typo, per Rafael]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Link: http://lkml.kernel.org/r/20200216191800.22423-1-aquini@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull device properties framework fix from Rafael Wysocki:
 "Revert a problematic commit from the 5.3 development cycle (Brendan
  Higgins)"

* tag 'devprop-5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Revert "software node: Simplify software_node_release() function"

Pull ACPI documentation fix from Rafael Wysocki:
 "Fix Sphinx format warinings in an ACPI fan document added recently
  (Randy Dunlap)"

* tag 'acpi-5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Documentation/admin-guide/acpi: fix fan_performance_states.rst warnings

Pull drm fixes from Dave Airlie:
 "Weekly fixes round, looks like a few people woke up, got a bunch of
  fixes across the drivers. Bit bigger than I'd like but they all seem
  fine and hopefully it quiets down now.

  sun4i, kirin, mediatek and exynos on the ARM side. virtio-gpu and core
  have some mmap fixes, and there is a dma-buf leak. one ttm fence leak
  is also fixed.

  Otherwise it's mostly amdgpu and i915.

  One of the i915 fixes is for a very long latency I was seeing (using
  latencytop) running gnome-shell locally when using firefox and eating
  nearly all my RAM, it really helps with desktop responsiveness esp
  when firefox is chewing a lot.

  dma-buf:
   - fix memory leak

  core:
   - shmem object mmap fix.

  ttm:
   - Fix fence leak in ttm_buffer_object_transfer().

  amdgpu:
   - Gfx reset fix for gfx9, 10
   - Fix for gfx10
   - DP MST fix
   - DCC fix
   - Renoir power fixes
   - Navi power fix

  i915:
   - Break up long lists of object reclaim with cond_resched()
   - PSR probe fix
   - TGL workarounds
   - Selftest return value fix
   - Drop timeline mutex while waiting for retirement
   - Wait for OA configuration completion before writes to OA buffer

  virtio:
   - Fix resource id creation race in virtio.
   - mmap fixes

  sun4i:
   - Fixes for sun4i VI layer format support.

  kirin:
   - kirin: Revert "Fix for hikey620 display offset problem"

  exynos:
   - fix a kernel oops problem in case that driver is loaded as module.
   - fix a regulator warning issue when I2C DDC adapter cannot be gathered.
   - print out an error message only in error case excepting -EPROBE_DEFER.

  mediatek:
   - overlay, cursor and gce fixes"
`

* tag 'drm-fixes-2020-03-06' of git://anongit.freedesktop.org/drm/drm: (38 commits)
  drm/amdgpu/display: navi1x copy dcn watermark clock settings to smu resume from s3 (v2)
  drm/amd/powerplay: map mclk to fclk for COMBINATIONAL_BYPASS case
  drm/amd/powerplay: fix pre-check condition for setting clock range
  drm/amd/display: fix dcc swath size calculations on dcn1
  drm/amd/display: Clear link settings on MST disable connector
  drm/amdgpu: disable 3D pipe 1 on Navi1x
  drm/amdgpu: clean wptr on wb when gpu recovery
  drm: kirin: Revert "Fix for hikey620 display offset problem"
  drm/i915/gt: Drop the timeline->mutex as we wait for retirement
  drm/i915/perf: Reintroduce wait on OA configuration completion
  drm/sun4i: Fix DE2 VI layer format support
  drm/sun4i: Add separate DE3 VI layer formats
  drm/sun4i: de2/de3: Remove unsupported VI layer formats
  drm/i915/selftests: Fix return in assert_mmap_offset()
  drm/i915: Protect i915_request_await_start from early waits
  drm/i915/tgl: Add Wa_1608008084
  drm/i915/tgl: Add Wa_22010178259:tgl
  drm/i915: Program MBUS with rmw during initialization
  drm/i915/psr: Force PSR probe only after full initialization
  drm/i915/gem: Break up long lists of object reclaim
  ...

Commit ee88f4eb ("ALSA: mips: Use managed buffer allocation") removed
superfluous hw_params/hw_free callbacks, but forgot to remove them where
they were used.

Fixes: ee88f4eb ("ALSA: mips: Use managed buffer allocation")
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Link: https://lore.kernel.org/r/20200306105837.31523-1-tsbogend@alpha.franken.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

* acpi-doc:
  Documentation/admin-guide/acpi: fix fan_performance_states.rst warnings