While playing with gigantic hugepages and memory_hotplug, I triggered
the following #PF when "cat memoryX/removable":

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  #PF error: [normal kernel read fault]
  PGD 0 P4D 0
  Oops: 0000 [#1] SMP PTI
  CPU: 1 PID: 1481 Comm: cat Tainted: G            E     4.20.0-rc6-mm1-1-default+ #18
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
  RIP: 0010:has_unmovable_pages+0x154/0x210
  Call Trace:
   is_mem_section_removable+0x7d/0x100
   removable_show+0x90/0xb0
   dev_attr_show+0x1c/0x50
   sysfs_kf_seq_show+0xca/0x1b0
   seq_read+0x133/0x380
   __vfs_read+0x26/0x180
   vfs_read+0x89/0x140
   ksys_read+0x42/0x90
   do_syscall_64+0x5b/0x180
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

The reason is we do not pass the Head to page_hstate(), and so, the call
to compound_order() in page_hstate() returns 0, so we end up checking
all hstates's size to match PAGE_SIZE.

Obviously, we do not find any hstate matching that size, and we return
NULL.  Then, we dereference that NULL pointer in
hugepage_migration_supported() and we got the #PF from above.

Fix that by getting the head page before calling page_hstate().

Also, since gigantic pages span several pageblocks, re-adjust the logic
for skipping pages.  While are it, we can also get rid of the
round_up().

[osalvador@suse.de: remove round_up(), adjust skip pages logic per Michal]
  Link: http://lkml.kernel.org/r/20181221062809.31771-1-osalvador@suse.de
Link: http://lkml.kernel.org/r/20181217225113.17864-1-osalvador@suse.deSigned-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 9b6f7e16 ("mm: rework memcg kernel stack accounting") will
result in fork failing if allocating a kernel stack for a task in
dup_task_struct exceeds the kernel memory allowance for that cgroup.

Unfortunately, it also results in a crash.

This is due to the code jumping to free_stack and calling
free_thread_stack when the memcg kernel stack charge fails, but without
tsk->stack pointing at the freshly allocated stack.

This in turn results in the vfree_atomic in free_thread_stack oopsing
with a backtrace like this:

#5 [ffffc900244efc88] die at ffffffff8101f0ab
 #6 [ffffc900244efcb8] do_general_protection at ffffffff8101cb86
 #7 [ffffc900244efce0] general_protection at ffffffff818ff082
    [exception RIP: llist_add_batch+7]
    RIP: ffffffff8150d487  RSP: ffffc900244efd98  RFLAGS: 00010282
    RAX: 0000000000000000  RBX: ffff88085ef55980  RCX: 0000000000000000
    RDX: ffff88085ef55980  RSI: 343834343531203a  RDI: 343834343531203a
    RBP: ffffc900244efd98   R8: 0000000000000001   R9: ffff8808578c3600
    R10: 0000000000000000  R11: 0000000000000001  R12: ffff88029f6c21c0
    R13: 0000000000000286  R14: ffff880147759b00  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #8 [ffffc900244efda0] vfree_atomic at ffffffff811df2c7
 #9 [ffffc900244efdb8] copy_process at ffffffff81086e37
#10 [ffffc900244efe98] _do_fork at ffffffff810884e0
#11 [ffffc900244eff10] sys_vfork at ffffffff810887ff
#12 [ffffc900244eff20] do_syscall_64 at ffffffff81002a43
    RIP: 000000000049b948  RSP: 00007ffcdb307830  RFLAGS: 00000246
    RAX: ffffffffffffffda  RBX: 0000000000896030  RCX: 000000000049b948
    RDX: 0000000000000000  RSI: 00007ffcdb307790  RDI: 00000000005d7421
    RBP: 000000000067370f   R8: 00007ffcdb3077b0   R9: 000000000001ed00
    R10: 0000000000000008  R11: 0000000000000246  R12: 0000000000000040
    R13: 000000000000000f  R14: 0000000000000000  R15: 000000000088d018
    ORIG_RAX: 000000000000003a  CS: 0033  SS: 002b

The simplest fix is to assign tsk->stack right where it is allocated.

Link: http://lkml.kernel.org/r/20181214231726.7ee4843c@imladris.surriel.com
Fixes: 9b6f7e16 ("mm: rework memcg kernel stack accounting")
Signed-off-by: Rik van Riel <riel@surriel.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When splitting a huge migrating PMD, we'll transfer all the existing PMD
bits and apply them again onto the small PTEs.  However we are fetching
the bits unconditionally via pmd_soft_dirty(), pmd_write() or
pmd_yound() while actually they don't make sense at all when it's a
migration entry.  Fix them up.  Since at it, drop the ifdef together as
not needed.

Note that if my understanding is correct about the problem then if
without the patch there is chance to lose some of the dirty bits in the
migrating pmd pages (on x86_64 we're fetching bit 11 which is part of
swap offset instead of bit 2) and it could potentially corrupt the
memory of an userspace program which depends on the dirty bit.

Link: http://lkml.kernel.org/r/20181213051510.20306-1-peterx@redhat.comSigned-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: <stable@vger.kernel.org>	[4.14+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If memory end is not aligned with the sparse memory section boundary,
the mapping of such a section is only partly initialized.  This may lead
to VM_BUG_ON due to uninitialized struct page access from
is_mem_section_removable() or test_pages_in_a_zone() function triggered
by memory_hotplug sysfs handlers:

Here are the the panic examples:
 CONFIG_DEBUG_VM=y
 CONFIG_DEBUG_VM_PGFLAGS=y

 kernel parameter mem=2050M
 --------------------------
 page:000003d082008000 is uninitialized and poisoned
 page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
 Call Trace:
 ( test_pages_in_a_zone+0xde/0x160)
   show_valid_zones+0x5c/0x190
   dev_attr_show+0x34/0x70
   sysfs_kf_seq_show+0xc8/0x148
   seq_read+0x204/0x480
   __vfs_read+0x32/0x178
   vfs_read+0x82/0x138
   ksys_read+0x5a/0xb0
   system_call+0xdc/0x2d8
 Last Breaking-Event-Address:
   test_pages_in_a_zone+0xde/0x160
 Kernel panic - not syncing: Fatal exception: panic_on_oops

 kernel parameter mem=3075M
 --------------------------
 page:000003d08300c000 is uninitialized and poisoned
 page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
 Call Trace:
 ( is_mem_section_removable+0xb4/0x190)
   show_mem_removable+0x9a/0xd8
   dev_attr_show+0x34/0x70
   sysfs_kf_seq_show+0xc8/0x148
   seq_read+0x204/0x480
   __vfs_read+0x32/0x178
   vfs_read+0x82/0x138
   ksys_read+0x5a/0xb0
   system_call+0xdc/0x2d8
 Last Breaking-Event-Address:
   is_mem_section_removable+0xb4/0x190
 Kernel panic - not syncing: Fatal exception: panic_on_oops

Fix the problem by initializing the last memory section of each zone in
memmap_init_zone() till the very end, even if it goes beyond the zone end.

Michal said:

: This has alwways been problem AFAIU.  It just went unnoticed because we
: have zeroed memmaps during allocation before f7f99100 ("mm: stop
: zeroing memory during allocation in vmemmap") and so the above test
: would simply skip these ranges as belonging to zone 0 or provided a
: garbage.
:
: So I guess we do care for post f7f99100 kernels mostly and
: therefore Fixes: f7f99100 ("mm: stop zeroing memory during
: allocation in vmemmap")

Link: http://lkml.kernel.org/r/20181212172712.34019-2-zaslonko@linux.ibm.com
Fixes: f7f99100 ("mm: stop zeroing memory during allocation in vmemmap")
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Suggested-by: Michal Hocko <mhocko@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull kvm fix from Paolo Bonzini:
 "A simple patch for a pretty bad bug: Unbreak AMD nested
  virtualization."

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: nSVM: fix switch to guest mmu

Pull timer fix from Ingo Molnar:
 "Fix a division by zero crash in the posix-timers code"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  posix-timers: Fix division by zero bug

Pull futex fix from Ingo Molnar:
 "A single fix for a robust futexes race between sys_exit() and
  sys_futex_lock_pi()"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Cure exit race

Pull x86 fixes from Ingo Molnar:
 "The biggest part is a series of reverts for the macro based GCC
  inlining workarounds. It caused regressions in distro build and other
  kernel tooling environments, and the GCC project was very receptive to
  fixing the underlying inliner weaknesses - so as time ran out we
  decided to do a reasonably straightforward revert of the patches. The
  plan is to rely on the 'asm inline' GCC 9 feature, which might be
  backported to GCC 8 and could thus become reasonably widely available
  on modern distros.

  Other than those reverts, there's misc fixes from all around the
  place.

  I wish our final x86 pull request for v4.20 was smaller..."

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs"
  Revert "x86/objtool: Use asm macros to work around GCC inlining bugs"
  Revert "x86/refcount: Work around GCC inlining bug"
  Revert "x86/alternatives: Macrofy lock prefixes to work around GCC inlining bugs"
  Revert "x86/bug: Macrofy the BUG table section handling, to work around GCC inlining bugs"
  Revert "x86/paravirt: Work around GCC inlining bugs when compiling paravirt ops"
  Revert "x86/extable: Macrofy inline assembly code to work around GCC inlining bugs"
  Revert "x86/cpufeature: Macrofy inline assembly code to work around GCC inlining bugs"
  Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"
  x86/mtrr: Don't copy uninitialized gentry fields back to userspace
  x86/fsgsbase/64: Fix the base write helper functions
  x86/mm/cpa: Fix cpa_flush_array() TLB invalidation
  x86/vdso: Pass --eh-frame-hdr to the linker
  x86/mm: Fix decoy address handling vs 32-bit builds
  x86/intel_rdt: Ensure a CPU remains online for the region's pseudo-locking sequence
  x86/dump_pagetables: Fix LDT remap address marker
  x86/mm: Fix guard hole handling

Pull final drm fix from Daniel Vetter:
 "Very calm week, so either everything perfect or everyone on holidays
  already. Just one array_index_nospec patch, also for stable"

* tag 'drm-fixes-2018-12-21' of git://anongit.freedesktop.org/drm/drm:
  drm/ioctl: Fix Spectre v1 vulnerabilities

Pull input fixes from Dmitry Torokhov:
 "Switching a few devices with Synaptics over to SMbus and disabling
  SMbus on a couple devices with Elan touchpads as they need more
  plumbing on PS/2 side"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: synaptics - enable SMBus for HP EliteBook 840 G4
  Input: elantech - disable elan-i2c for P52 and P72
  Input: synaptics - enable RMI on ThinkPad T560
  Input: omap-keypad - fix idle configuration to not block SoC idle states

Pull GPIO fixes from Linus Walleij:
 "Hopefully last round of GPIO fixes.

  The ACPI patch is pretty important for some laptop users, the rest is
  driver-specific for embedded (mostly ARM) systems.

  I took out one ACPI patch that wasn't critical enough because I
  couldn't justify sending it at this point, and that is why the commit
  date is today, but the patches have been in linux-next.

  Sorry for not sending some of them earlier :(

  Notice that we have a co-maintainer for GPIO now, Bartosz Golaszewski,
  and he might jump in and make some pull requests at times when I am
  off.

  Summary:

   - ACPI IRQ request deferral

   - OMAP: revert deferred wakeup quirk

   - MAX7301: fix DMA safe memory handling

   - MVEBU: selective probe failure on missing clk"

* tag 'gpio-v4.20-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: mvebu: only fail on missing clk if pwm is actually to be used
  gpio: max7301: fix driver for use with CONFIG_VMAP_STACK
  gpio: gpio-omap: Revert deferred wakeup quirk handling for regressions
  gpiolib-acpi: Only defer request_irq for GpioInt ACPI event handlers

Pull smb3 fix from Steve French:
 "An important smb3 fix for an regression to some servers introduced by
  compounding optimization to rmdir.

  This fix has been tested by multiple developers (including me) with
  the usual private xfstesting, but also by the new cifs/smb3 "buildbot"
  xfstest VMs (thank you Ronnie and Aurelien for good work on this
  automation). The automated testing has been updated so that it will
  catch problems like this in the future.

  Note that Pavel discovered (very recently) some unrelated but
  extremely important bugs in credit handling (smb3 flow control problem
  that can lead to disconnects/reconnects) when compounding, that I
  would have liked to send in ASAP but the complete testing of those two
  fixes may not be done in time and have to wait for 4.21"

* tag '4.20-rc7-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: Fix rmdir compounding regression to strict servers

dmesg reports that "Your touchpad (PNP: SYN3052 SYN0100 SYN0002 PNP0f13)
says it can support a different bus."

I've tested the offered psmouse.synaptics_intertouch=1 with 4.18.x and
4.19.x and it seems to work well. No problems seen with suspend/resume.

Also, it appears that RMI/SMBus mode is actually required for 3-4 finger
multitouch gestures to work -- otherwise they are not reported at all.

Information from dmesg in both modes:

  psmouse serio3: synaptics: Touchpad model: 1, fw: 8.2, id: 0x1e2b1,
      caps: 0xf00123/0x840300/0x2e800/0x0, board id: 3139, fw id: 2000742

  psmouse serio3: synaptics: Trying to set up SMBus access
  rmi4_smbus 6-002c: registering SMbus-connected sensor
  rmi4_f01 rmi4-00.fn01: found RMI device,
      manufacturer: Synaptics, product: TM3139-001, fw id: 2000742
Signed-off-by: Mantas Mikulėnas <grawity@gmail.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

The current implementation of elan_i2c is known to not support those
2 laptops.

A proper fix is to tweak both elantech and elan_i2c to transmit the
correct information from PS/2, which would make a bad candidate for
stable.

So to give us some time for fixing the root of the problem, disable
elan_i2c for the devices we know are not behaving properly.

Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1803600
Link: https://bugs.archlinux.org/task/59714
Fixes: df077237 Input: elantech - detect new ICs and setup Host Notify for them

Cc: stable@vger.kernel.org  # v4.18+
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

The gpio IP on Armada 370 at offset 0x18180 has neither a clk nor pwm
registers. So there is no need for a clk as the pwm isn't used anyhow.
So only check for the clk in the presence of the pwm registers. This fixes
a failure to probe the gpio driver for the above mentioned gpio device.

Fixes: 757642f9 ("gpio: mvebu: Add limited PWM support")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

spi_read() and spi_write() require DMA-safe memory. When
CONFIG_VMAP_STACK is selected, those functions cannot be used
with buffers on stack.

This patch replaces calls to spi_read() and spi_write() by
spi_write_then_read() which doesn't require DMA-safe buffers.

Fixes: 0c36ec31 ("gpio: gpio driver for max7301 SPI GPIO expander")
Cc: <stable@vger.kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Commit ec0daae6 ("gpio: omap: Add level wakeup handling for omap4
based SoCs") attempted to fix omap4 GPIO wakeup handling as it was
blocking deeper SoC idle states. However this caused a regression for
GPIOs during runtime having over second long latencies for Ethernet
GPIO interrupt as reportedy by Russell King <rmk+kernel@armlinux.org.uk>.

Let's fix this issue by doing a partial revert of the breaking commit.
We still want to keep the quirk handling around as it is also used for
OMAP_GPIO_QUIRK_IDLE_REMOVE_TRIGGER.

The real fix for omap4 GPIO wakeup handling involves fixes for
omap_set_gpio_trigger() and omap_gpio_unmask_irq() and will be posted
separately. And we must keep the wakeup bit enabled during runtime
because of module doing clock autogating with autoidle configured.
Reported-by: Russell King <rmk+kernel@armlinux.org.uk>
Fixes: ec0daae6 ("gpio: omap: Add level wakeup handling for omap4
based SoCs")
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Ladislav Michl <ladis@linux-mips.org>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Pull i2c fixes from Wolfram Sang:
 "I2C has a MAINTAINERS update for you, so people will be immediately
  pointed to the right person for this previously orphaned driver.

  And one of Arnd's build warning fixes for a new driver added this
  cycle"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: nvidia-gpu: mark resume function as __maybe_unused
  MAINTAINERS: add entry for i2c-axxia driver

Pull UBI/UBIFS fixes from Richard Weinberger:

 - Kconfig dependency fixes for our new auth feature

 - Fix for selecting the right compressor when creating a fs

 - Bugfix for a bug in UBIFS's O_TMPFILE implementation

 - Refcounting fixes for UBI

* tag 'upstream-4.20-rc7' of git://git.infradead.org/linux-ubifs:
  ubifs: Handle re-linking of inodes correctly while recovery
  ubi: Do not drop UBI device reference before using
  ubi: Put MTD device after it is not used
  ubifs: Fix default compression selection in ubifs
  ubifs: Fix memory leak on error condition
  ubifs: auth: Add CONFIG_KEYS dependency
  ubifs: CONFIG_UBIFS_FS_AUTHENTICATION should depend on UBIFS_FS
  ubifs: replay: Fix high stack usage

Fix spectre v1 vuln in drm_ioctl
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
From: Sean Paul <sean@poorly.run>
Link: https://patchwork.freedesktop.org/patch/msgid/20181220165740.GA42344@art_vandelay

Pull m68k fix from Geert Uytterhoeven:
 "Fix memblock-related crashes"

* tag 'm68k-for-v4.20-tag2' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
  m68k: Fix memblock-related crashes

Merge tag 'kbuild-fixes-v4.20-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fix from Masahiro Yamada:
 "Fix false positive warning/error about missing library for objtool"

* tag 'kbuild-fixes-v4.20-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: fix false positive warning/error about missing libelf

Pull char/misc driver fixes from Greg KH:
 "Here are three tiny last-minute driver fixes for 4.20-rc8 that resolve
  some reported issues, and one MAINTAINERS file update.

  All of them are related to the hyper-v subsystem, it seems people are
  actually testing and using it now, which is nice to see :)

  The fixes are:
   - uio_hv_generic: fix for opening multiple times
   - Remove PCI dependancy on hyperv drivers
   - return proper error code for an unopened channel.

  And Sasha has signed up to help out with the hyperv maintainership.

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

* tag 'char-misc-4.20-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels
  x86, hyperv: remove PCI dependency
  MAINTAINERS: Patch monkey for the Hyper-V code
  uio_hv_generic: set callbacks on open

Pull tty/serial fix from Greg KH:
 "Here is a single fix, a revert, for the 8250 serial driver to resolve
  a reported problem.

  There was some attempted patches to fix the issue, but people are
  arguing about them, so reverting the patch to revert back to the 4.19
  and older behavior is the best thing to do at this late in the release
  cycle.

  The revert has been in linux-next with no reported issues"

* tag 'tty-4.20-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  Revert "serial: 8250: Fix clearing FIFOs in RS485 mode again"

Pull USB fixes and ids from Greg KH:
 "Here are some late xhci fixes for 4.20-rc8 as well as a few new device
  ids for the option usb-serial driver.

  The xhci fixes resolve some many-reported issues and all of these have
  been in linux-next for a while with no reported problems"

* tag 'usb-4.20-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: xhci: fix 'broken_suspend' placement in struct xchi_hcd
  xhci: Don't prevent USB2 bus suspend in state check intended for USB3 only
  USB: serial: option: add Telit LN940 series
  USB: serial: option: add Fibocom NL668 series
  USB: serial: option: add Simcom SIM7500/SIM7600 (MBIM mode)
  USB: serial: option: add GosunCn ZTE WeLink ME3630
  USB: serial: option: add HP lt4132

Pull MMC fixes from Ulf Hansson:
 "MMC core:
   - Restore code to allow BKOPS and CACHE ctrl even if no HPI support
   - Reset HPI enabled state during re-init
   - Use a default minimum timeout when enabling CACHE ctrl

  MMC host:
   - omap_hsmmc: Fix DMA API warning
   - sdhci-tegra: Fix dt parsing of SDMMC pads autocal values
   - Correct register accesses when enabling v4 mode"

* tag 'mmc-v4.20-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  mmc: core: Use a minimum 1600ms timeout when enabling CACHE ctrl
  mmc: core: Allow BKOPS and CACHE ctrl even if no HPI support
  mmc: core: Reset HPI enabled state during re-init and in case of errors
  mmc: omap_hsmmc: fix DMA API warning
  mmc: tegra: Fix for SDMMC pads autocal parsing from dt
  mmc: sdhci: Fix sdhci_do_enable_v4_mode

This reverts commit 61c6de66.

The reverted commit added page reference counting to iomap page
structures that are used to track block size < page size state. This
was supposed to align the code with page migration page accounting
assumptions, but what it has done instead is break XFS filesystems.
Every fstests run I've done on sub-page block size XFS filesystems
has since picking up this commit 2 days ago has failed with bad page
state errors such as:

# ./run_check.sh "-m rmapbt=1,reflink=1 -i sparse=1 -b size=1k" "generic/038"
....
SECTION       -- xfs
FSTYP         -- xfs (debug)
PLATFORM      -- Linux/x86_64 test1 4.20.0-rc6-dgc+
MKFS_OPTIONS  -- -f -m rmapbt=1,reflink=1 -i sparse=1 -b size=1k /dev/sdc
MOUNT_OPTIONS -- /dev/sdc /mnt/scratch

generic/038 454s ...
 run fstests generic/038 at 2018-12-20 18:43:05
 XFS (sdc): Unmounting Filesystem
 XFS (sdc): Mounting V5 Filesystem
 XFS (sdc): Ending clean mount
 BUG: Bad page state in process kswapd0  pfn:3a7fa
 page:ffffea0000ccbeb0 count:0 mapcount:0 mapping:ffff88800d9b6360 index:0x1
 flags: 0xfffffc0000000()
 raw: 000fffffc0000000 dead000000000100 dead000000000200 ffff88800d9b6360
 raw: 0000000000000001 0000000000000000 00000000ffffffff
 page dumped because: non-NULL mapping
 CPU: 0 PID: 676 Comm: kswapd0 Not tainted 4.20.0-rc6-dgc+ #915
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-1 04/01/2014
 Call Trace:
  dump_stack+0x67/0x90
  bad_page.cold.116+0x8a/0xbd
  free_pcppages_bulk+0x4bf/0x6a0
  free_unref_page_list+0x10f/0x1f0
  shrink_page_list+0x49d/0xf50
  shrink_inactive_list+0x19d/0x3b0
  shrink_node_memcg.constprop.77+0x398/0x690
  ? shrink_slab.constprop.81+0x278/0x3f0
  shrink_node+0x7a/0x2f0
  kswapd+0x34b/0x6d0
  ? node_reclaim+0x240/0x240
  kthread+0x11f/0x140
  ? __kthread_bind_mask+0x60/0x60
  ret_from_fork+0x24/0x30
 Disabling lock debugging due to kernel taint
....

The failures are from anyway that frees pages and empties the
per-cpu page magazines, so it's not a predictable failure or an easy
to debug failure.

generic/038 is a reliable reproducer of this problem - it has a 9 in
10 failure rate on one of my test machines. Failure on other
machines have been at random points in fstests runs but every run
has ended up tripping this problem. Hence generic/038 was used to
bisect the failure because it was the most reliable failure.

It is too close to the 4.20 release (not to mention holidays) to
try to diagnose, fix and test the underlying cause of the problem,
so reverting the commit is the only option we have right now. The
revert has been tested against a current tot 4.20-rc7+ kernel across
multiple machines running sub-page block size XFs filesystems and
none of the bad page state failures have been seen.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Cc: Piotr Jaroszynski <pjaroszynski@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Brian Foster <bfoster@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull networking fixes from David Miller:

 1) Off by one in netlink parsing of mac802154_hwsim, from Alexander
    Aring.

 2) nf_tables RCU usage fix from Taehee Yoo.

 3) Flow dissector needs nhoff and thoff clamping, from Stanislav
    Fomichev.

 4) Missing sin6_flowinfo initialization in SCTP, from Xin Long.

 5) Spectrev1 in ipmr and ip6mr, from Gustavo A. R. Silva.

 6) Fix r8169 crash when DEBUG_SHIRQ is enabled, from Heiner Kallweit.

 7) Fix SKB leak in rtlwifi, from Larry Finger.

 8) Fix state pruning in bpf verifier, from Jakub Kicinski.

 9) Don't handle completely duplicate fragments as overlapping, from
    Michal Kubecek.

10) Fix memory corruption with macb and 64-bit DMA, from Anssi Hannula.

11) Fix TCP fallback socket release in smc, from Myungho Jung.

12) gro_cells_destroy needs to napi_disable, from Lorenzo Bianconi.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (130 commits)
  rds: Fix warning.
  neighbor: NTF_PROXY is a valid ndm_flag for a dump request
  net: mvpp2: fix the phylink mode validation
  net/sched: cls_flower: Remove old entries from rhashtable
  net/tls: allocate tls context using GFP_ATOMIC
  iptunnel: make TUNNEL_FLAGS available in uapi
  gro_cell: add napi_disable in gro_cells_destroy
  lan743x: Remove MAC Reset from initialization
  net/mlx5e: Remove the false indication of software timestamping support
  net/mlx5: Typo fix in del_sw_hw_rule
  net/mlx5e: RX, Fix wrong early return in receive queue poll
  ipv6: explicitly initialize udp6_addr in udp_sock_create6()
  bnxt_en: Fix ethtool self-test loopback.
  net/rds: remove user triggered WARN_ON in rds_sendmsg
  net/rds: fix warn in rds_message_alloc_sgs
  ath10k: skip sending quiet mode cmd for WCN3990
  mac80211: free skb fraglist before freeing the skb
  nl80211: fix memory leak if validate_pae_over_nl80211() fails
  net/smc: fix TCP fallback socket release
  vxge: ensure data0 is initialized in when fetching firmware version information
  ...

nr is indirectly controlled by user-space, hence leading to a
potential exploitation of the Spectre variant 1 vulnerability.

This issue was detected with the help of Smatch:

drivers/gpu/drm/drm_ioctl.c:805 drm_ioctl() warn: potential spectre issue 'dev->driver->ioctls' [r]
drivers/gpu/drm/drm_ioctl.c:810 drm_ioctl() warn: potential spectre issue 'drm_ioctls' [r] (local cap)
drivers/gpu/drm/drm_ioctl.c:892 drm_ioctl_flags() warn: potential spectre issue 'drm_ioctls' [r] (local cap)

Fix this by sanitizing nr before using it to index dev->driver->ioctls
and drm_ioctls.

Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].

[1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2

Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20181220000015.GA18973@embeddedor

>> net/rds/send.c:1109:42: warning: Using plain integer as NULL pointer

Fixes: ea010070 ("net/rds: fix warn in rds_message_alloc_sgs")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull virtio fix from Michael Tsirkin:
 "A last-minute fix for a test build"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio: fix test build after uio.h change

Pull NFS client bugfixes from Trond Myklebust:

 - Fix TCP socket disconnection races by ensuring we always call
   xprt_disconnect_done() after releasing the socket.

 - Fix a race when clearing both XPRT_CONNECTING and XPRT_LOCKED

 - Remove xprt_connect_status() so it does not mask errors that should
   be handled by call_connect_status()

* tag 'nfs-for-4.20-6' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  SUNRPC: Remove xprt_connect_status()
  SUNRPC: Fix a race with XPRT_CONNECTING
  SUNRPC: Fix disconnection races

Pull kvm fixes from Paolo Bonzini:

 -  One nasty use-after-free bugfix, from this merge window however

 -  A less nasty use-after-free that can only zero some words at the
    beginning of the page, and hence is not really exploitable

 -  A NULL pointer dereference

 -  A dummy implementation of an AMD chicken bit MSR that Windows uses
    for some unknown reason

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm: x86: Add AMD's EX_CFG to the list of ignored MSRs
  KVM: X86: Fix NULL deref in vcpu_scan_ioapic
  KVM: Fix UAF in nested posted interrupt processing
  KVM: fix unregistering coalesced mmio zone from wrong bus

Pull dma-mapping fix from Christoph Hellwig:
 "Fix a regression in dma-direct that didn't take account the magic AMD
  memory encryption mask in the DMA address"

* tag 'dma-mapping-4.20-4' of git://git.infradead.org/users/hch/dma-mapping:
  dma-direct: do not include SME mask in the DMA supported check

When dumping proxy entries the dump request has NTF_PROXY set in
ndm_flags. strict mode checking needs to be updated to allow this
flag.

Fixes: 51183d23 ("net/neighbor: Update neigh_dump_info for strict data checking")
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The mvpp2_phylink_validate() sets all modes that are supported by a
given PPv2 port. An mistake made the 10000baseT_Full mode being
advertised in some cases when a port wasn't configured to perform at
10G. This patch fixes this.

Fixes: d97c9f4a ("net: mvpp2: 1000baseX support")
Reported-by: Russell King <linux@armlinux.org.uk>
Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When replacing a rule we add the new rule to the rhashtable
but only remove the old if not in skip_sw.
This commit fix this and remove the old rule anyway.

Fixes: 35cc3cef ("net/sched: cls_flower: Reject duplicated rules also under skip_sw")
Signed-off-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

create_ctx can be called from atomic context, hence use
GFP_ATOMIC instead of GFP_KERNEL.

[  395.962599] BUG: sleeping function called from invalid context at mm/slab.h:421
[  395.979896] in_atomic(): 1, irqs_disabled(): 0, pid: 16254, name: openssl
[  395.996564] 2 locks held by openssl/16254:
[  396.010492]  #0: 00000000347acb52 (sk_lock-AF_INET){+.+.}, at: do_tcp_setsockopt.isra.44+0x13b/0x9a0
[  396.029838]  #1: 000000006c9552b5 (device_spinlock){+...}, at: tls_init+0x1d/0x280
[  396.047675] CPU: 5 PID: 16254 Comm: openssl Tainted: G           O      4.20.0-rc6+ #25
[  396.066019] Hardware name: Supermicro X10SRA-F/X10SRA-F, BIOS 2.0c 09/25/2017
[  396.083537] Call Trace:
[  396.096265]  dump_stack+0x5e/0x8b
[  396.109876]  ___might_sleep+0x216/0x250
[  396.123940]  kmem_cache_alloc_trace+0x1b0/0x240
[  396.138800]  create_ctx+0x1f/0x60
[  396.152504]  tls_init+0xbd/0x280
[  396.166135]  tcp_set_ulp+0x191/0x2d0
[  396.180035]  ? tcp_set_ulp+0x2c/0x2d0
[  396.193960]  do_tcp_setsockopt.isra.44+0x148/0x9a0
[  396.209013]  __sys_setsockopt+0x7c/0xe0
[  396.223054]  __x64_sys_setsockopt+0x20/0x30
[  396.237378]  do_syscall_64+0x4a/0x180
[  396.251200]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: df9d4a17 ("net/tls: sleeping function from invalid context")
Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ip l add dev tun type gretap external
ip r a 10.0.0.1 encap ip dst 192.168.152.171 id 1000 dev gretap

For gretap Key example when the command set the id but don't set the
TUNNEL_KEY flags. There is no key field in the send packet

In the lwtunnel situation, some TUNNEL_FLAGS should can be set by
userspace
Signed-off-by: wenxu <wenxu@ucloud.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add napi_disable routine in gro_cells_destroy since starting from
commit c42858ea ("gro_cells: remove spinlock protecting receive
queues") gro_cell_poll and gro_cells_destroy can run concurrently on
napi_skbs list producing a kernel Oops if the tunnel interface is
removed while gro_cell_poll is running. The following Oops has been
triggered removing a vxlan device while the interface is receiving
traffic

[ 5628.948853] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[ 5628.949981] PGD 0 P4D 0
[ 5628.950308] Oops: 0002 [#1] SMP PTI
[ 5628.950748] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 4.20.0-rc6+ #41
[ 5628.952940] RIP: 0010:gro_cell_poll+0x49/0x80
[ 5628.955615] RSP: 0018:ffffc9000004fdd8 EFLAGS: 00010202
[ 5628.956250] RAX: 0000000000000000 RBX: ffffe8ffffc08150 RCX: 0000000000000000
[ 5628.957102] RDX: 0000000000000000 RSI: ffff88802356bf00 RDI: ffffe8ffffc08150
[ 5628.957940] RBP: 0000000000000026 R08: 0000000000000000 R09: 0000000000000000
[ 5628.958803] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000040
[ 5628.959661] R13: ffffe8ffffc08100 R14: 0000000000000000 R15: 0000000000000040
[ 5628.960682] FS:  0000000000000000(0000) GS:ffff88803ea00000(0000) knlGS:0000000000000000
[ 5628.961616] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5628.962359] CR2: 0000000000000008 CR3: 000000000221c000 CR4: 00000000000006b0
[ 5628.963188] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 5628.964034] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 5628.964871] Call Trace:
[ 5628.965179]  net_rx_action+0xf0/0x380
[ 5628.965637]  __do_softirq+0xc7/0x431
[ 5628.966510]  run_ksoftirqd+0x24/0x30
[ 5628.966957]  smpboot_thread_fn+0xc5/0x160
[ 5628.967436]  kthread+0x113/0x130
[ 5628.968283]  ret_from_fork+0x3a/0x50
[ 5628.968721] Modules linked in:
[ 5628.969099] CR2: 0000000000000008
[ 5628.969510] ---[ end trace 9d9dedc7181661fe ]---
[ 5628.970073] RIP: 0010:gro_cell_poll+0x49/0x80
[ 5628.972965] RSP: 0018:ffffc9000004fdd8 EFLAGS: 00010202
[ 5628.973611] RAX: 0000000000000000 RBX: ffffe8ffffc08150 RCX: 0000000000000000
[ 5628.974504] RDX: 0000000000000000 RSI: ffff88802356bf00 RDI: ffffe8ffffc08150
[ 5628.975462] RBP: 0000000000000026 R08: 0000000000000000 R09: 0000000000000000
[ 5628.976413] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000040
[ 5628.977375] R13: ffffe8ffffc08100 R14: 0000000000000000 R15: 0000000000000040
[ 5628.978296] FS:  0000000000000000(0000) GS:ffff88803ea00000(0000) knlGS:0000000000000000
[ 5628.979327] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5628.980044] CR2: 0000000000000008 CR3: 000000000221c000 CR4: 00000000000006b0
[ 5628.980929] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 5628.981736] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 5628.982409] Kernel panic - not syncing: Fatal exception in interrupt
[ 5628.983307] Kernel Offset: disabled

Fixes: c42858ea ("gro_cells: remove spinlock protecting receive queues")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>