Pull tomoyo updates from James Morris:
 "Fixes to enable fuzz testing, and a fix for calculating whether a
  filesystem is user-modifiable"

* 'next-tomoyo2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  tomoyo: Don't emit WARNING: string while fuzzing testing.
  tomoyo: Change pathname calculation for read-only filesystems.
  tomoyo: Check address length before reading address family
  tomoyo: Add a kernel config option for fuzzing testing.

Pull xtensa updates from Max Filippov:

 - implement atomic operations using exclusive access Xtensa option
   operations

 - add support for Xtensa cores with memory protection unit (MPU)

 - clean up xtensa-specific kernel-only headers

 - fix error path in simdisk_setup

* tag 'xtensa-20190510' of git://github.com/jcmvbkbc/linux-xtensa:
  xtensa: implement initialize_cacheattr for MPU cores
  xtensa: add exclusive atomics support
  xtensa: clean up inline assembly in futex.h
  xtensa: replace variant/core.h with asm/core.h
  xtensa: drop ifdef __KERNEL__ from kernel-only headers
  xtensa: set proper error code for simdisk_setup()
  xtensa: fix incorrect fd close in error case of simdisk_setup()

Commit cff0e6c3ec3e6230 ("tomoyo: Add a kernel config option for fuzzing
testing.") enabled the learning mode, but syzkaller is detecting any
"WARNING:" string as a crash. Thus, disable TOMOYO's quota warning if
built for fuzzing testing.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: James Morris <jamorris@linux.microsoft.com>

Commit 5625f2e3 ("TOMOYO: Change pathname for non-rename()able
filesystems.") intended to be applied to filesystems where the content is
not controllable from the userspace (e.g. proc, sysfs, securityfs), based
on an assumption that such filesystems do not support rename() operation.

But it turned out that read-only filesystems also do not support rename()
operation despite the content is controllable from the userspace, and that
commit is annoying TOMOYO users who want to use e.g. squashfs as the root
filesystem due to use of local name which does not start with '/'.

Therefore, based on an assumption that filesystems which require the
device argument upon mount() request is an indication that the content
is controllable from the userspace, do not use local name if a filesystem
does not support rename() operation but requires the device argument upon
mount() request.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jamorris@linux.microsoft.com>

KMSAN will complain if valid address length passed to bind()/connect()/
sendmsg() is shorter than sizeof("struct sockaddr"->sa_family) bytes.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jamorris@linux.microsoft.com>

syzbot is reporting kernel panic triggered by memory allocation fault
injection before loading TOMOYO's policy [1]. To make the fuzzing tests
useful, we need to assign a profile other than "disabled" (no-op) mode.
Therefore, let's allow syzbot to load TOMOYO's built-in policy for
"learning" mode using a kernel config option. This option must not be
enabled for kernels built for production system, for this option also
disables domain/program checks when modifying policy configuration via
/sys/kernel/security/tomoyo/ interface.

[1] https://syzkaller.appspot.com/bug?extid=29569ed06425fcf67a95Reported-by: syzbot <syzbot+e1b8084e532b6ee7afab@syzkaller.appspotmail.com>
Reported-by: syzbot <syzbot+29569ed06425fcf67a95@syzkaller.appspotmail.com>
Reported-by: syzbot <syzbot+2ee3f8974c2e7dc69feb@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jamorris@linux.microsoft.com>

Pull more documentation updates from Jonathan Corbet:
 "Some late arriving documentation changes. In particular, this contains
  the conversion of the x86 docs to RST, which has been in the works for
  some time but needed a couple of final tweaks"

* tag 'docs-5.2a' of git://git.lwn.net/linux: (29 commits)
  Documentation: x86: convert x86_64/machinecheck to reST
  Documentation: x86: convert x86_64/cpu-hotplug-spec to reST
  Documentation: x86: convert x86_64/fake-numa-for-cpusets to reST
  Documentation: x86: convert x86_64/5level-paging.txt to reST
  Documentation: x86: convert x86_64/mm.txt to reST
  Documentation: x86: convert x86_64/uefi.txt to reST
  Documentation: x86: convert x86_64/boot-options.txt to reST
  Documentation: x86: convert i386/IO-APIC.txt to reST
  Documentation: x86: convert usb-legacy-support.txt to reST
  Documentation: x86: convert orc-unwinder.txt to reST
  Documentation: x86: convert resctrl_ui.txt to reST
  Documentation: x86: convert microcode.txt to reST
  Documentation: x86: convert pti.txt to reST
  Documentation: x86: convert amd-memory-encryption.txt to reST
  Documentation: x86: convert intel_mpx.txt to reST
  Documentation: x86: convert protection-keys.txt to reST
  Documentation: x86: convert pat.txt to reST
  Documentation: x86: convert mtrr.txt to reST
  Documentation: x86: convert tlb.txt to reST
  Documentation: x86: convert zero-page.txt to reST
  ...

Merge tag 'printk-for-5.2-fixes' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/pmladek/printk

Pull printk fixup from Petr Mladek:
 "Replace the problematic probe_kernel_read() with original simple
  pointer checks in vsprintf()"

* tag 'printk-for-5.2-fixes' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
  vsprintf: Do not break early boot with probing addresses

Pull pidfd fixes from Christian Brauner:
 "This fixes two bugs:

   - The first one reported by Linus whereby the pidfd-metadata binary
     was not placed in a .gitignore file.

   - The second one is rather urgent and fixes a locking issue found by
     syzkaller.

     What happened is that during process creation we need to check
     whether the cgroup we are in allows us to fork. To perform this
     check the cgroup needs to guard itself against threadgroup changes
     and takes a lock.

     Prior to CLONE_PIDFD the cleanup target "bad_fork_free_pid" would
     also need to release said lock. That's not true anymore since
     CLONE_PIDFD so this is fixed here.

     Syzkaller has tested the patch and was not able to reproduce the
     issue"

* tag 'pidfd-fixes-v5.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/brauner/linux:
  fork: do not release lock that wasn't taken
  samples: add .gitignore for pidfd-metadata

Pull x86 platform driver updates from Andy Shevchenko:
 "Gathered pile of patches for Platform Drivers x86. No surprises and no
  merge conflicts. Business as usual.

  Summary:

   - New driver of power button for Basin Cove PMIC.

   - ASUS WMI driver has got a Fn lock mode switch support.

   - Resolve a never end story with non working Wi-Fi on newer Lenovo
     Ideapad computers. Now the black list is replaced with white list.

   - New facility to debug S0ix failures on Intel Atom platforms. The
     Intel PMC and accompanying drivers are cleaned up.

   - Mellanox got a new TmFifo driver. Besides tachometer sensor and
     watchdog are enabled on Mellanox platforms.

   - The information of embedded controller is now recognized on new
     Thinkpads. Bluetooth driver on Thinkpads is blacklisted for some
     models.

   - Touchscreen DMI driver extended to support 'jumper ezpad 6 pro b'
     and Myria MY8307 2-in-1.

   - Additionally few small fixes here and there for WMI and ACPI laptop
     drivers.

   - The following is an automated git shortlog grouped by driver:

   - alienware-wmi:
      - printing the wrong error code
      - fix kfree on potentially uninitialized pointer

   - asus-wmi:
      - Add fn-lock mode switch support

   - dell-laptop:
      - fix rfkill functionality

   - dell-rbtn:
      - Add missing #include

   - ideapad-laptop:
      - Remove no_hw_rfkill_list

   - intel_pmc_core:
      - Allow to dump debug registers on S0ix failure
      - Convert to a platform_driver
      - Mark local function static

   - intel_pmc_ipc:
      - Don't map non-used optional resources
      - Apply same width for offset definitions
      - Use BIT() macro
      - adding error handling

   - intel_punit_ipc:
      - Revert "Fix resource ioremap warning"

   - mlx-platform:
      - Add mlx-wdt platform driver activation
      - Add support for tachometer speed register
      - Add TmFifo driver for Mellanox BlueField Soc

   - sony-laptop:
      - Fix unintentional fall-through

   - thinkpad_acpi:
      - cleanup for Thinkpad ACPI led
      - Mark expected switch fall-throughs
      - fix spelling mistake "capabilites" -> "capabilities"
      - Read EC information on newer models
      - Disable Bluetooth for some machines

   - touchscreen_dmi:
      - Add info for 'jumper ezpad 6 pro b' touchscreen
      - Add info for Myria MY8307 2-in-1"

* tag 'platform-drivers-x86-v5.2-1' of git://git.infradead.org/linux-platform-drivers-x86: (26 commits)
  platform/x86: Add support for Basin Cove power button
  platform/x86: asus-wmi: Add fn-lock mode switch support
  platform/x86: ideapad-laptop: Remove no_hw_rfkill_list
  platform/x86: touchscreen_dmi: Add info for 'jumper ezpad 6 pro b' touchscreen
  platform/x86: thinkpad_acpi: cleanup for Thinkpad ACPI led
  platform/x86: thinkpad_acpi: Mark expected switch fall-throughs
  platform/x86: sony-laptop: Fix unintentional fall-through
  platform/x86: alienware-wmi: printing the wrong error code
  platform/x86: intel_pmc_core: Allow to dump debug registers on S0ix failure
  platform/x86: intel_pmc_core: Convert to a platform_driver
  platform/x86: mlx-platform: Add mlx-wdt platform driver activation
  platform/x86: mlx-platform: Add support for tachometer speed register
  platform/mellanox: Add TmFifo driver for Mellanox BlueField Soc
  platform/x86: thinkpad_acpi: fix spelling mistake "capabilites" -> "capabilities"
  platform/x86: intel_punit_ipc: Revert "Fix resource ioremap warning"
  platform/x86: intel_pmc_ipc: Don't map non-used optional resources
  platform/x86: intel_pmc_ipc: Apply same width for offset definitions
  platform/x86: intel_pmc_ipc: Use BIT() macro
  platform/x86: alienware-wmi: fix kfree on potentially uninitialized pointer
  platform/x86: dell-laptop: fix rfkill functionality
  ...

Pull fbdev updates from Bartlomiej Zolnierkiewicz:
 "Four small fixes for fb core, updates for udlfb, sm712fb, macfb and
  atafb drivers. Redundant code removals from amba-clcd and atmel_lcdfb
  drivers. Minor fixes/cleanups for other fb drivers

  Detailed summary:

   - fix regression in fbcon logo handling on 'quiet' boots (Andreas
     Schwab)

   - fix divide-by-zero error in fb_var_to_videomode() (Shile Zhang)

   - fix 'WARNING in __alloc_pages_nodemask' bug (Jiufei Xue)

   - list all PCI memory BARs as conflicting apertures (Gerd Hoffmann)

   - update udlfb driver: fix sleeping inside spinlock, add mutex around
     rendering calls and remove redundant code (Mikulas Patocka)

   - update sm712fb driver: fix SM720 support related issues (Yifeng Li)

   - update macfb driver: fix DAFB colour table pointer initialization
     and remove redundant code (Finn Thain)

   - update atafb driver: fix kexec support, use dev_*() calls instead
     of printk() and remove obsolete module support (Geert Uytterhoeven)

   - add support to mxsfb driver for skipping display initialization for
     flicker-free display takeover from bootloader (Melchior Franz)

   - remove Versatile and Nomadik board families support from amba-clcd
     driver as they are handled by DRM driver nowadays (Linus Walleij)

   - remove no longer needed AVR and platform_data support from
     atmel_lcdfb driver (Alexandre Belloni)

   - misc fixes (Colin Ian King, Julia Lawall, Gustavo A. R. Silva,
     Aditya Pakki, Kangjie Lu, YueHaibing)

   - misc cleanups (Enrico Weigelt, Kefeng Wang)"

* tag 'fbdev-v5.2' of git://github.com/bzolnier/linux: (38 commits)
  video: fbdev: Use dev_get_drvdata()
  fbcon: Don't reset logo_shown when logo is currently shown
  video: fbdev: atmel_lcdfb: remove set but not used variable 'pdata'
  video: fbdev: mxsfb: remove set but not used variable 'line_count'
  video: fbdev: pvr2fb: remove set but not used variable 'size'
  fbdev: fix WARNING in __alloc_pages_nodemask bug
  video: amba-clcd: Decomission Versatile and Nomadik
  fbdev: sm712fb: fix memory frequency by avoiding a switch/case fallthrough
  fbdev: fix divide error in fb_var_to_videomode
  fbdev: sm712fb: use 1024x768 by default on non-MIPS, fix garbled display
  fbdev: sm712fb: fix support for 1024x768-16 mode
  fbdev: sm712fb: fix crashes and garbled display during DPMS modesetting
  fbdev: sm712fb: fix crashes during framebuffer writes by correctly mapping VRAM
  fbdev: sm712fb: fix boot screen glitch when sm712fb replaces VGA
  fbdev: sm712fb: fix VRAM detection, don't set SR70/71/74/75
  fbdev: sm712fb: fix brightness control on reboot, don't set SR30
  fbdev: sm712fb: fix white screen of death on reboot, don't set CR3B-CR3F
  video: imsttfb: fix potential NULL pointer dereferences
  video: hgafb: fix potential NULL pointer dereference
  fbdev: list all pci memory bars as conflicting apertures
  ...

Merge tag 'pwm/for-5.2-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "Nothing out of the ordinary this cycle.

  The bulk of this is a collection of fixes for existing drivers and
  some cleanups. There's one new driver for i.MX SoCs and addition of
  support for some new variants to existing drivers"

* tag 'pwm/for-5.2-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
  pwm: meson: Add clock source configuration for Meson G12A
  dt-bindings: pwm: Update bindings for the Meson G12A Family
  pwm: samsung: Don't uses devm_*() functions in ->request()
  pwm: Clear chip_data in pwm_put()
  pwm: Add i.MX TPM PWM driver support
  dt-bindings: pwm: Add i.MX TPM PWM binding
  pwm: imx27: Use devm_platform_ioremap_resource() to simplify code
  pwm: meson: Use the spin-lock only to protect register modifications
  pwm: meson: Don't disable PWM when setting duty repeatedly
  pwm: meson: Consider 128 a valid pre-divider
  pwm: sysfs: fix typo "its" -> "it's"
  pwm: tiehrpwm: Enable compilation for ARCH_K3
  dt-bindings: pwm: tiehrpwm: Add TI AM654 SoC specific compatible
  pwm: tiehrpwm: Update shadow register for disabling PWMs
  pwm: img: Turn final 'else if' into 'else' in img_pwm_config
  pwm: Fix deadlock warning when removing PWM device

Pull mailbox updates from Jassi Brar:

 - New driver: Armada 37xx mailbox controller

 - Misc: Use devm_ api for imx and platform_get_irq for stm32

* tag 'mailbox-v5.2' of git://git.linaro.org/landing-teams/working/fujitsu/integration:
  mailbox: Add support for Armada 37xx rWTM mailbox
  dt-bindings: mailbox: Document armada-3700-rwtm-mailbox binding
  mailbox: stm32-ipcc: check invalid irq
  mailbox: imx: use devm_platform_ioremap_resource() to simplify code

The commit 3e5903eb ("vsprintf: Prevent crash when dereferencing
invalid pointers") broke boot on several architectures. The common
pattern is that probe_kernel_read() is not working during early
boot because userspace access framework is not ready.

It is a generic problem. We have to avoid any complex external
functions in vsprintf() code, especially in the common path.
They might break printk() easily and are hard to debug.

Replace probe_kernel_read() with some simple checks for obvious
problems.

Details:

1. Report on Power:

Kernel crashes very early during boot with with CONFIG_PPC_KUAP and
CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG

The problem is the combination of some new code called via printk(),
check_pointer() which calls probe_kernel_read(). That then calls
allow_user_access() (PPC_KUAP) and that uses mmu_has_feature() too early
(before we've patched features). With the JUMP_LABEL debug enabled that
causes us to call printk() & dump_stack() and we end up recursing and
overflowing the stack.

Because it happens so early you don't get any output, just an apparently
dead system.

The stack trace (which you don't see) is something like:

  ...
  dump_stack+0xdc
  probe_kernel_read+0x1a4
  check_pointer+0x58
  string+0x3c
  vsnprintf+0x1bc
  vscnprintf+0x20
  printk_safe_log_store+0x7c
  printk+0x40
  dump_stack_print_info+0xbc
  dump_stack+0x8
  probe_kernel_read+0x1a4
  probe_kernel_read+0x19c
  check_pointer+0x58
  string+0x3c
  vsnprintf+0x1bc
  vscnprintf+0x20
  vprintk_store+0x6c
  vprintk_emit+0xec
  vprintk_func+0xd4
  printk+0x40
  cpufeatures_process_feature+0xc8
  scan_cpufeatures_subnodes+0x380
  of_scan_flat_dt_subnodes+0xb4
  dt_cpu_ftrs_scan_callback+0x158
  of_scan_flat_dt+0xf0
  dt_cpu_ftrs_scan+0x3c
  early_init_devtree+0x360
  early_setup+0x9c

2. Report on s390:

vsnprintf invocations, are broken on s390. For example, the early boot
output now looks like this where the first (efault) should be
the linux_banner:

[    0.099985] (efault)
[    0.099985] setup: Linux is running as a z/VM guest operating system in 64-bit mode
[    0.100066] setup: The maximum memory size is 8192MB
[    0.100070] cma: Reserved 4 MiB at (efault)
[    0.100100] numa: NUMA mode: (efault)

The reason for this, is that the code assumes that
probe_kernel_address() works very early. This however is not true on
at least s390. Uaccess on KERNEL_DS works only after page tables have
been setup on s390, which happens with setup_arch()->paging_init().

Any probe_kernel_address() invocation before that will return -EFAULT.

Fixes: 3e5903eb ("vsprintf: Prevent crash when dereferencing invalid pointers")
Link: http://lkml.kernel.org/r/20190510084213.22149-1-pmladek@suse.com
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Russell Currey <ruscur@russell.cc>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Stephen Rothwell <sfr@ozlabs.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>

Pull powerpc updates from Michael Ellerman:
 "Slightly delayed due to the issue with printk() calling
  probe_kernel_read() interacting with our new user access prevention
  stuff, but all fixed now.

  The only out-of-area changes are the addition of a cpuhp_state, small
  additions to Documentation and MAINTAINERS updates.

  Highlights:

   - Support for Kernel Userspace Access/Execution Prevention (like
     SMAP/SMEP/PAN/PXN) on some 64-bit and 32-bit CPUs. This prevents
     the kernel from accidentally accessing userspace outside
     copy_to/from_user(), or ever executing userspace.

   - KASAN support on 32-bit.

   - Rework of where we map the kernel, vmalloc, etc. on 64-bit hash to
     use the same address ranges we use with the Radix MMU.

   - A rewrite into C of large parts of our idle handling code for
     64-bit Book3S (ie. power8 & power9).

   - A fast path entry for syscalls on 32-bit CPUs, for a 12-17% speedup
     in the null_syscall benchmark.

   - On 64-bit bare metal we have support for recovering from errors
     with the time base (our clocksource), however if that fails
     currently we hang in __delay() and never crash. We now have support
     for detecting that case and short circuiting __delay() so we at
     least panic() and reboot.

   - Add support for optionally enabling the DAWR on Power9, which had
     to be disabled by default due to a hardware erratum. This has the
     effect of enabling hardware breakpoints for GDB, the downside is a
     badly behaved program could crash the machine by pointing the DAWR
     at cache inhibited memory. This is opt-in obviously.

   - xmon, our crash handler, gets support for a read only mode where
     operations that could change memory or otherwise disturb the system
     are disabled.

  Plus many clean-ups, reworks and minor fixes etc.

  Thanks to: Christophe Leroy, Akshay Adiga, Alastair D'Silva, Alexey
  Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar,
  Anton Blanchard, Ben Hutchings, Bo YU, Breno Leitao, Cédric Le Goater,
  Christopher M. Riedl, Christoph Hellwig, Colin Ian King, David Gibson,
  Ganesh Goudar, Gautham R. Shenoy, George Spelvin, Greg Kroah-Hartman,
  Greg Kurz, Horia Geantă, Jagadeesh Pagadala, Joel Stanley, Joe
  Perches, Julia Lawall, Laurentiu Tudor, Laurent Vivier, Lukas Bulwahn,
  Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu Malaterre, Michael
  Neuling, Mukesh Ojha, Nathan Fontenot, Nathan Lynch, Nicholas Piggin,
  Nick Desaulniers, Oliver O'Halloran, Peng Hao, Qian Cai, Ravi
  Bangoria, Rick Lindsley, Russell Currey, Sachin Sant, Stewart Smith,
  Sukadev Bhattiprolu, Thomas Huth, Tobin C. Harding, Tyrel Datwyler,
  Valentin Schneider, Wei Yongjun, Wen Yang, YueHaibing"

* tag 'powerpc-5.2-1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (205 commits)
  powerpc/64s: Use early_mmu_has_feature() in set_kuap()
  powerpc/book3s/64: check for NULL pointer in pgd_alloc()
  powerpc/mm: Fix hugetlb page initialization
  ocxl: Fix return value check in afu_ioctl()
  powerpc/mm: fix section mismatch for setup_kup()
  powerpc/mm: fix redundant inclusion of pgtable-frag.o in Makefile
  powerpc/mm: Fix makefile for KASAN
  powerpc/kasan: add missing/lost Makefile
  selftests/powerpc: Add a signal fuzzer selftest
  powerpc/booke64: set RI in default MSR
  ocxl: Provide global MMIO accessors for external drivers
  ocxl: move event_fd handling to frontend
  ocxl: afu_irq only deals with IRQ IDs, not offsets
  ocxl: Allow external drivers to use OpenCAPI contexts
  ocxl: Create a clear delineation between ocxl backend & frontend
  ocxl: Don't pass pci_dev around
  ocxl: Split pci.c
  ocxl: Remove some unused exported symbols
  ocxl: Remove superfluous 'extern' from headers
  ocxl: read_pasid never returns an error, so make it void
  ...

Avoid calling cgroup_threadgroup_change_end() without having called
cgroup_threadgroup_change_begin() first.

During process creation we need to check whether the cgroup we are in
allows us to fork. To perform this check the cgroup needs to guard itself
against threadgroup changes and takes a lock.
Prior to CLONE_PIDFD the cleanup target "bad_fork_free_pid" would also need
to call cgroup_threadgroup_change_end() because said lock had already been
taken.
However, this is not the case anymore with the addition of CLONE_PIDFD. We
are now allocating a pidfd before we check whether the cgroup we're in can
fork and thus prior to taking the lock. So when copy_process() fails at the
right step it would release a lock we haven't taken.
This bug is not even very subtle to be honest. It's just not very clear
from the naming of cgroup_threadgroup_change_{begin,end}() that a lock is
taken.

Here's the relevant splat:

entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7fec849
Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90
90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90
90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000ffed5a8c EFLAGS: 00000246 ORIG_RAX: 0000000000000078
RAX: ffffffffffffffda RBX: 0000000000003ffc RCX: 0000000000000000
RDX: 00000000200005c0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000012 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(depth <= 0)
WARNING: CPU: 1 PID: 7744 at kernel/locking/lockdep.c:4052 __lock_release
kernel/locking/lockdep.c:4052 [inline]
WARNING: CPU: 1 PID: 7744 at kernel/locking/lockdep.c:4052
lock_release+0x667/0xa00 kernel/locking/lockdep.c:4321
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 7744 Comm: syz-executor007 Not tainted 5.1.0+ #4
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x172/0x1f0 lib/dump_stack.c:113
  panic+0x2cb/0x65c kernel/panic.c:214
  __warn.cold+0x20/0x45 kernel/panic.c:566
  report_bug+0x263/0x2b0 lib/bug.c:186
  fixup_bug arch/x86/kernel/traps.c:179 [inline]
  fixup_bug arch/x86/kernel/traps.c:174 [inline]
  do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272
  do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291
  invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:972
RIP: 0010:__lock_release kernel/locking/lockdep.c:4052 [inline]
RIP: 0010:lock_release+0x667/0xa00 kernel/locking/lockdep.c:4321
Code: 0f 85 a0 03 00 00 8b 35 77 66 08 08 85 f6 75 23 48 c7 c6 a0 55 6b 87
48 c7 c7 40 25 6b 87 4c 89 85 70 ff ff ff e8 b7 a9 eb ff <0f> 0b 4c 8b 85
70 ff ff ff 4c 89 ea 4c 89 e6 4c 89 c7 e8 52 63 ff
RSP: 0018:ffff888094117b48 EFLAGS: 00010086
RAX: 0000000000000000 RBX: 1ffff11012822f6f RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815af236 RDI: ffffed1012822f5b
RBP: ffff888094117c00 R08: ffff888092bfc400 R09: fffffbfff113301d
R10: fffffbfff113301c R11: ffffffff889980e3 R12: ffffffff8a451df8
R13: ffffffff8142e71f R14: ffffffff8a44cc80 R15: ffff888094117bd8
  percpu_up_read.constprop.0+0xcb/0x110 include/linux/percpu-rwsem.h:92
  cgroup_threadgroup_change_end include/linux/cgroup-defs.h:712 [inline]
  copy_process.part.0+0x47ff/0x6710 kernel/fork.c:2222
  copy_process kernel/fork.c:1772 [inline]
  _do_fork+0x25d/0xfd0 kernel/fork.c:2338
  __do_compat_sys_x86_clone arch/x86/ia32/sys_ia32.c:240 [inline]
  __se_compat_sys_x86_clone arch/x86/ia32/sys_ia32.c:236 [inline]
  __ia32_compat_sys_x86_clone+0xbc/0x140 arch/x86/ia32/sys_ia32.c:236
  do_syscall_32_irqs_on arch/x86/entry/common.c:334 [inline]
  do_fast_syscall_32+0x281/0xd54 arch/x86/entry/common.c:405
  entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7fec849
Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90
90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90
90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000ffed5a8c EFLAGS: 00000246 ORIG_RAX: 0000000000000078
RAX: ffffffffffffffda RBX: 0000000000003ffc RCX: 0000000000000000
RDX: 00000000200005c0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000012 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..

Reported-and-tested-by: syzbot+3286e58549edc479faae@syzkaller.appspotmail.com
Fixes: b3e58382 ("clone: add CLONE_PIDFD")
Signed-off-by: Christian Brauner <christian@brauner.io>

Ignore the pidfd-metadata binary so it doesn't show up in unwanted
scenarios.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christian Brauner <christian@brauner.io>

Pull vfs mount fix from Al Viro:
 "Fix for umount -l/mount --move race caught by syzbot yesterday..."

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  do_move_mount(): fix an unsafe use of is_anon_ns()

Pull networking fixes from David Miller:
 "Several bug fixes, many are quick merge-window regression cures:

   - When NLM_F_EXCL is not set, allow same fib rule insertion. From
     Hangbin Liu.

   - Several cures in sja1105 DSA driver (while loop exit condition fix,
     return of negative u8, etc.) from Vladimir Oltean.

   - Handle tx/rx delays in realtek PHY driver properly, from Serge
     Semin.

   - Double free in cls_matchall, from Pieter Jansen van Vuuren.

   - Disable SIOCSHWTSTAMP in macvlan/vlan containers, from Hangbin Liu.

   - Endainness fixes in aqc111, from Oliver Neukum.

   - Handle errors in packet_init properly, from Haibing Yue.

   - Various W=1 warning fixes in kTLS, from Jakub Kicinski"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (34 commits)
  nfp: add missing kdoc
  net/tls: handle errors from padding_length()
  net/tls: remove set but not used variables
  docs/btf: fix the missing section marks
  nfp: bpf: fix static check error through tightening shift amount adjustment
  selftests: bpf: initialize bpf_object pointers where needed
  packet: Fix error path in packet_init
  net/tcp: use deferred jump label for TCP acked data hook
  net: aquantia: fix undefined devm_hwmon_device_register_with_info reference
  aqc111: fix double endianness swap on BE
  aqc111: fix writing to the phy on BE
  aqc111: fix endianness issue in aqc111_change_mtu
  vlan: disable SIOCSHWTSTAMP in container
  macvlan: disable SIOCSHWTSTAMP in container
  tipc: fix hanging clients using poll with EPOLLOUT flag
  tuntap: synchronize through tfiles array instead of tun->numqueues
  tuntap: fix dividing by zero in ebpf queue selection
  dwmac4_prog_mtl_tx_algorithms() missing write operation
  ptp_qoriq: fix NULL access if ptp dt node missing
  net/sched: avoid double free on matchall reoffload
  ...

Add missing kdoc for app member.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jakub Kicinski says:

====================
net/tls: fix W=1 build warnings

This small series cleans up two outstanding W=1 build
warnings in tls code.  Both are set but not used variables.
The first case looks fairly straightforward.  In the second
I think it's better to propagate the error code, even if
not doing some does not lead to a crash with current code.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

At the time padding_length() is called the record header
is still part of the message.  If malicious TLS 1.3 peer
sends an all-zero record padding_length() will stop at
the record header, and return full length of the data
including the tail_size.

Subsequent subtraction of prot->overhead_size from rxm->full_len
will cause rxm->full_len to turn negative.  skb accessors,
however, will always catch resulting out-of-bounds operation,
so in practice this fix comes down to returning the correct
error code.  It also fixes a set but not used warning.

This code was added by commit 130b392c ("net: tls: Add tls 1.3 support").

CC: Dave Watson <davejwatson@fb.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 4504ab0e ("net/tls: Inform user space about send buffer availability")
made us report write_space regardless whether partial record
push was successful or not.  Remove the now unused return value
to clean up the following W=1 warning:

net/tls/tls_device.c: In function ‘tls_device_write_space’:
net/tls/tls_device.c:546:6: warning: variable ‘rc’ set but not used [-Wunused-but-set-variable]
  int rc = 0;
      ^~

CC: Vakul Garg <vakul.garg@nxp.com>
CC: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Alexei Starovoitov says:

====================
pull-request: bpf 2019-05-09

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) three small fixes from Gary, Jiong and Lorenz.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The section titles of 3.4 and 3.5 are not marked correctly.
Signed-off-by: Gary Lin <glin@suse.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

NFP shift instruction has something special. If shift direction is left
then shift amount of 1 to 31 is specified as 32 minus the amount to shift.

But no need to do this for indirect shift which has shift amount be 0. Even
after we do this subtraction, shift amount 0 will be turned into 32 which
will eventually be encoded the same as 0 because only low 5 bits are
encoded, but shift amount be 32 will fail the FIELD_PREP check done later
on shift mask (0x1f), due to 32 is out of mask range. Such error has been
observed when compiling nfp/bpf/jit.c using gcc 8.3 + O3.

This issue has started when indirect shift support added after which the
incoming shift amount to __emit_shf could be 0, therefore it is at that
time shift amount adjustment inside __emit_shf should have been tightened.

Fixes: 991f5b36 ("nfp: bpf: support logic indirect shifts (BPF_[L|R]SH | BPF_X)")
Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Reported-by: Pablo Cascón <pablo.cascon@netronome.com
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

There are a few tests which call bpf_object__close on uninitialized
bpf_object*, which may segfault. Explicitly zero-initialise these pointers
to avoid this.
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Pull sparc updates from David Miller:
 "Here we go:

   - Fix various long standing issues in the sparc 32-bit IOMMU support
     code, from Christoph Hellwig.

   - Various other code cleanups and simplifications all over. From
     Gustavo A. R. Silva, Jagadeesh Pagadala, Masahiro Yamada, Mauro
     Carvalho Chehab, Mike Rapoport"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: simplify reduce_memory() function
  sparc: use struct_size() in kzalloc()
  docs: sparc: convert to ReST
  sparc/iommu: merge iommu_get_one and __sbus_iommu_map_page
  sparc/iommu: use __sbus_iommu_map_page to implement the map_sg path
  sparc/iommu: fix __sbus_iommu_map_page for highmem pages
  sparc/iommu: move per-page flushing into __sbus_iommu_map_page
  sparc/iommu: pass a physical address to iommu_get_one
  sparc/iommu: create a common helper for map_sg
  sparc/iommu: merge iommu_release_one and sbus_iommu_unmap_page
  sparc/iommu: use sbus_iommu_unmap_page in sbus_iommu_unmap_sg
  sparc/iommu: use !PageHighMem to check if a page has a kernel mapping
  sparc: vdso: add FORCE to the build rule of %.so
  arch:sparc:kernel/uprobes.c : Remove duplicate header

Pull clk framework updates from Stephen Boyd:
 "We have a couple new features and changes in the core clk framework
  this time around because we've finally gotten around to fixing some
  long standing issues. There's still work to do though, so this pull
  request is largely laying down the foundation for all the driver
  changes to come in the next merge window.

  The first problem we're alleviating is how parents of clks are
  specified. With the new method, we should see lots of drivers migrate
  away from the current design of string comparisons on the entire clk
  tree to a more direct method where they can use clk_hw pointers or
  more localized names specified in DT or via clkdev. This should reduce
  our reliance on string comparisons for all the topology description
  logic that we've been using for years and hopefully speed some things
  up while avoiding problems we have with generating clk names.

  Beyond that we also got rid of the CLK_IS_BASIC flag because it wasn't
  really helping anyone and we introduced big-endian versions of the
  basic clk types so that we can get rid of clk_{readl,writel}(). Both
  of these are things that driver developers have tried to use over the
  years that I typically bat away during code reviews because they're
  not useful. It's great to see these two things go away so maintainers
  can save time not worrying about these things.

  On the driver side we got the usual collection of new SoC support and
  non-critical fixes and updates to existing code. The big topics that
  stand out are the new driver support for Mediatek MT8183 and MT8516
  SoCs, Amlogic Meson8b and G12a SoCs, and the SiFive FU540 SoC. The
  other patches in the driver pile are mostly fixes for things that are
  being used for the first time or additions for clks that couldn't be
  tested before because there wasn't a consumer driver that exercised
  them. Details are below and also in the sub-maintainer tags.

  Core:
   - Remove clk_readl() and introduce BE versions of basic clk types
   - Rewrite how clk parents can be specified to allow DT/clkdev lookups
   - Removal of the CLK_IS_BASIC clk flag
   - Framework documentation updates and fixes

  New Drivers:
   - Support for STM32F769
   - AT91 sam9x60 PMC support
   - SiFive FU540 PRCI and PLL support
   - Qualcomm QCS404 CDSP clk support
   - Qualcomm QCS404 Turing clk support
   - Mediatek MT8183 clock support
   - Mediatek MT8516 clock support
   - Milbeaut M10V clk controller support
   - Support for Cirrus Logic Lochnagar clks

  Updates:
   - Rework AT91 sckc DT bindings
   - Fix slow RC oscillator issue on sama5d3
   - Mark UFS clk as critical on Hi-Silicon hi3660 SoCs
   - Various static analysis fixes/finds and const markings
   - Video Engine (ECLK) support on Aspeed SoCs
   - Xilinx ZynqMP Versal platform support
   - Convert Xilinx ZynqMP driver to be struct oriented
   - Fixes for Rockchip rk3328 and rk3288 SoCs
   - Sub-type for Rockchip SoCs where mux and divider aren't a single register
   - Remove SNVS clock from i.MX7UPL clock driver and bindings
   - Improve i.MX5 clock driver for i.MX50 support
   - Addition of ADC clock definition for Exynos 5410 SoC (Odroid XU)
   - Export a new clock for the MBUS controller on the A13
   - Allwinner H6 fixes to support a finer clocking of the video and VPU engines
   - Add g12a support in the Amlogic axg audio clock controller
   - Add missing PCI USB clock on Rensas RZ/N1
   - Add Z2 (Cortex-A53) clocks on Rensas R-Car E3 and RZ/G2E
   - A new helper DIV64_U64_ROUND_CLOSEST() in <linux/math64.h>
   - VPU and Video Decoder clocks on Amlogic Meson8b
   - Finally remove the wrong ABP Meson8b clock id
   - Add Video Decoder, PCIe PLL, and CPU Clocks on Amlogic G12A
   - Re-expose SAR_ADC_SEL and CTS_OSCIN on Amlogic G12A AO clock controller
   - Un-expose some Amlogic AXG-Audio input clocks IDs"

* tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (172 commits)
  clk: Cache core in clk_fetch_parent_index() without names
  clk: imx: correct pfdv2 gate_bit/vld_bit operations
  clk: sifive: add a driver for the SiFive FU540 PRCI IP block
  clk: analogbits: add Wide-Range PLL library
  clk: imx: clk-pllv3: mark expected switch fall-throughs
  clk: imx8mq: Add dsi_ipg_div
  clk: imx: pllv4: add fractional-N pll support
  clk: sunxi-ng: Use the correct style for SPDX License Identifier
  clk: sprd: Use the correct style for SPDX License Identifier
  clk: renesas: Use the correct style for SPDX License Identifier
  clk: qcom: Use the correct style for SPDX License Identifier
  clk: davinci: Use the correct style for SPDX License Identifier
  clk: actions: Use the correct style for SPDX License Identifier
  clk: imx: keep uart clock on during system boot
  clk: imx: correct i.MX7D AV PLL num/denom offset
  dt-bindings: clk: add documentation for the SiFive PRCI driver
  clk: stm32mp1: Add ddrperfm clock
  clk: Remove CLK_IS_BASIC clk flag
  clock: milbeaut: Add Milbeaut M10V clock controller
  dt-bindings: clock: milbeaut: add Milbeaut clock description
  ...

Pull RTC updates from Alexandre Belloni:
 "A huge series from me this cycle. I went through many drivers to set
  the date and time range supported by the RTC which helps solving HW
  limitation when the time comes (as early as next year for some). This
  time, I focused on drivers using .set_mms and .set_mmss64, allowing me
  to remove those callbacks. About a third of the patches got reviews, I
  actually own the RTCs and I tested another third and the remaining one
  are unlikely to cause any issues.

  Other than that, a single new driver and the usual fixes here and there.

  Summary:

  Subsystem:

   - set_mmss and set_mmss64 rtc_ops removal

   - Fix timestamp value for RTC_TIMESTAMP_BEGIN_1900

   - Use SPDX identifier for the core

   - validate upper bound of tm->tm_year

  New driver:

   - Aspeed BMC SoC RTC

  Drivers:

   - abx80x: use rtc_add_group

   - ds3232: nvram support

   - pcf85063: add alarm, nvram, offset correction and microcrystal
     rv8263 support

   - x1205: add of_match_table

   - Use set_time instead of set_mms/set_mmss64 for: ab3100, coh901331,
     digicolor, ds1672, ds2404, ep93xx, imxdi, jz4740, lpc32xx, mc13xxx,
     mxc, pcap, stmp3xxx, test, wm831x, xgene.

   - Set RTC range for: ab3100, at91sam9, coh901331, da9063, digicolor,
     dm355evm, ds1672, ds2404, ep39xx, goldfish, imxdi, jz4740, lpc32xx,
     mc13xxx, mv, mxc, omap, pcap, pcf85063, pcf85363, ps3, sh,
     stmp3xxx, sun4v, tegra, wm831x, xgene.

   - Switch to rtc_time64_to_tm/rtc_tm_to_time64 for the driver that
     properly set the RTC range.

   - Use dev_get_drvdata instead of multiple indirections"

* tag 'rtc-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (177 commits)
  rtc: snvs: Use __maybe_unused instead of #if CONFIG_PM_SLEEP
  rtc: imxdi: remove unused variable
  rtc: drop set_mms and set_mmss64
  rtc: pcap: convert to SPDX identifier
  rtc: pcap: use .set_time
  rtc: pcap: switch to rtc_time64_to_tm/rtc_tm_to_time64
  rtc: pcap: set range
  rtc: digicolor: convert to SPDX identifier
  rtc: digicolor: use .set_time
  rtc: digicolor: set range
  rtc: digicolor: fix possible race condition
  rtc: jz4740: convert to SPDX identifier
  rtc: jz4740: rework invalid time detection
  rtc: jz4740: use dev_pm_set_wake_irq() to simplify code
  rtc: jz4740: use .set_time
  rtc: jz4740: remove useless check
  rtc: jz4740: switch to rtc_time64_to_tm/rtc_tm_to_time64
  rtc: jz4740: set range
  rtc: 88pm860x: prevent use-after-free on device remove
  rtc: Use dev_get_drvdata()
  ...

Pull i2c updates from Wolfram Sang:

 - API for late atomic transfers (e.g. to shut down via PMIC). We have a
   seperate callback now which is called under clearly defined
   conditions. In-kernel users are converted, too.

 - new driver for the AMD PCIe MP2 I2C controller

 - large refactoring for at91 and bcm-iproc (both gain slave support due
   to this)

 - and a good share of various driver improvements anf fixes

* 'i2c/for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (57 commits)
  dt-bindings: i2c: riic: document r7s9210 support
  i2c: imx-lpi2c: Use __maybe_unused instead of #if CONFIG_PM_SLEEP
  i2c-piix4: Add Hygon Dhyana SMBus support
  i2c: core: apply 'is_suspended' check for SMBus, too
  i2c: core: ratelimit 'transfer when suspended' errors
  i2c: iproc: Change driver to use 'BIT' macro
  i2c: riic: Add Runtime PM support
  i2c: mux: demux-pinctrl: use struct_size() in devm_kzalloc()
  i2c: mux: pca954x: allow management of device idle state via sysfs
  i2c: mux: pca9541: remove support for unused platform data
  i2c: mux: pca954x: remove support for unused platform data
  dt-bindings: i2c: i2c-mtk: add support for MT8516
  i2c: axxia: use auto cmd for last message
  i2c: gpio: flag atomic capability if possible
  i2c: algo: bit: add flag to whitelist atomic transfers
  i2c: stu300: use xfer_atomic callback to bail out early
  i2c: ocores: enable atomic xfers
  i2c: ocores: refactor setup for polling
  i2c: tegra-bpmp: convert to use new atomic callbacks
  i2c: omap: Add the master_xfer_atomic hook
  ...

Pull NFS client updates from Anna Schumaker:
 "Highlights include:

  Stable bugfixes:
   - Fall back to MDS if no deviceid is found rather than aborting   # v4.11+
   - NFS4: Fix v4.0 client state corruption when mount

  Features:
   - Much improved handling of soft mounts with NFS v4.0:
       - Reduce risk of false positive timeouts
       - Faster failover of reads and writes after a timeout
       - Added a "softerr" mount option to return ETIMEDOUT instead of
         EIO to the application after a timeout
   - Increase number of xprtrdma backchannel requests
   - Add additional xprtrdma tracepoints
   - Improved send completion batching for xprtrdma

  Other bugfixes and cleanups:
   - Return -EINVAL when NFS v4.2 is passed an invalid dedup mode
   - Reduce usage of GFP_ATOMIC pages in SUNRPC
   - Various minor NFS over RDMA cleanups and bugfixes
   - Use the correct container namespace for upcalls
   - Don't share superblocks between user namespaces
   - Various other container fixes
   - Make nfs_match_client() killable to prevent soft lockups
   - Don't mark all open state for recovery when handling recallable
     state revoked flag"

* tag 'nfs-for-5.2-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (69 commits)
  SUNRPC: Rebalance a kref in auth_gss.c
  NFS: Fix a double unlock from nfs_match,get_client
  nfs: pass the correct prototype to read_cache_page
  NFSv4: don't mark all open state for recovery when handling recallable state revoked flag
  SUNRPC: Fix an error code in gss_alloc_msg()
  SUNRPC: task should be exit if encode return EKEYEXPIRED more times
  NFS4: Fix v4.0 client state corruption when mount
  PNFS fallback to MDS if no deviceid found
  NFS: make nfs_match_client killable
  lockd: Store the lockd client credential in struct nlm_host
  NFS: When mounting, don't share filesystems between different user namespaces
  NFS: Convert NFSv2 to use the container user namespace
  NFSv4: Convert the NFS client idmapper to use the container user namespace
  NFS: Convert NFSv3 to use the container user namespace
  SUNRPC: Use namespace of listening daemon in the client AUTH_GSS upcall
  SUNRPC: Use the client user namespace when encoding creds
  NFS: Store the credential of the mount process in the nfs_server
  SUNRPC: Cache cred of process creating the rpc_client
  xprtrdma: Remove stale comment
  xprtrdma: Update comments that reference ib_drain_qp
  ...

The reduce_memory() function clampls the available memory to a limit
defined by the "mem=" command line parameter. It takes into account the
amount of already reserved memory and excludes it from the limit
calculations.

Rather than traverse memblocks and remove them by hand, use
memblock_reserved_size() to account the reserved memory and
memblock_enforce_memory_limit() to clamp the available memory.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

One of the more common cases of allocation size calculations is finding the
size of a structure that has a zero-sized array at the end, along with memory
for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can now
use the new struct_size() helper:

instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull cgroup updates from Tejun Heo:
 "This includes Roman's cgroup2 freezer implementation.

  It's a separate machanism from cgroup1 freezer. Instead of blocking
  user tasks in arbitrary uninterruptible sleeps, the new implementation
  extends jobctl stop - frozen tasks are trapped in jobctl stop until
  thawed and can be killed and ptraced. Lots of thanks to Oleg for
  sheperding the effort.

  Other than that, there are a few trivial changes"

* 'for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: never call do_group_exit() with task->frozen bit set
  kernel: cgroup: fix misuse of %x
  cgroup: get rid of cgroup_freezer_frozen_exit()
  cgroup: prevent spurious transition into non-frozen state
  cgroup: Remove unused cgrp variable
  cgroup: document cgroup v2 freezer interface
  cgroup: add tracing points for cgroup v2 freezer
  cgroup: make TRACE_CGROUP_PATH irq-safe
  kselftests: cgroup: add freezer controller self-tests
  kselftests: cgroup: don't fail on cg_kill_all() error in cg_destroy()
  cgroup: cgroup v2 freezer
  cgroup: protect cgroup->nr_(dying_)descendants by css_set_lock
  cgroup: implement __cgroup_task_count() helper
  cgroup: rename freezer.c into legacy_freezer.c
  cgroup: remove extra cgroup_migrate_finish() call

Pull workqueue updates from Tejun Heo:
 "Only three commits, of which two are trivial.

  The non-trivial chagne is Thomas's patch to switch workqueue from
  sched RCU to regular one. The use of sched RCU is mostly historic and
  doesn't really buy us anything noticeable"

* 'for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: Use normal rcu
  kernel/workqueue: Document wq_worker_last_func() argument
  kernel/workqueue: Use __printf markup to silence compiler in function 'alloc_workqueue'

kernel BUG at lib/list_debug.c:47!
invalid opcode: 0000 [#1
CPU: 0 PID: 12914 Comm: rmmod Tainted: G        W         5.1.0+ #47
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
RIP: 0010:__list_del_entry_valid+0x53/0x90
Code: 48 8b 32 48 39 fe 75 35 48 8b 50 08 48 39 f2 75 40 b8 01 00 00 00 5d c3 48
89 fe 48 89 c2 48 c7 c7 18 75 fe 82 e8 cb 34 78 ff <0f> 0b 48 89 fe 48 c7 c7 50 75 fe 82 e8 ba 34 78 ff 0f 0b 48 89 f2
RSP: 0018:ffffc90001c2fe40 EFLAGS: 00010286
RAX: 000000000000004e RBX: ffffffffa0184000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff888237a17788 RDI: 00000000ffffffff
RBP: ffffc90001c2fe40 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90001c2fe10 R11: 0000000000000000 R12: 0000000000000000
R13: ffffc90001c2fe50 R14: ffffffffa0184000 R15: 0000000000000000
FS:  00007f3d83634540(0000) GS:ffff888237a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555c350ea818 CR3: 0000000231677000 CR4: 00000000000006f0
Call Trace:
 unregister_pernet_operations+0x34/0x120
 unregister_pernet_subsys+0x1c/0x30
 packet_exit+0x1c/0x369 [af_packet
 __x64_sys_delete_module+0x156/0x260
 ? lockdep_hardirqs_on+0x133/0x1b0
 ? do_syscall_64+0x12/0x1f0
 do_syscall_64+0x6e/0x1f0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

When modprobe af_packet, register_pernet_subsys
fails and does a cleanup, ops->list is set to LIST_POISON1,
but the module init is considered to success, then while rmmod it,
BUG() is triggered in __list_del_entry_valid which is called from
unregister_pernet_subsys. This patch fix error handing path in
packet_init to avoid possilbe issue if some error occur.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull arch/csky perf update from Guo Ren:
 "Add support for perf unwind-libdw"

* tag 'csky-for-linus-5.2-perf-unwind-libdw' of git://github.com/c-sky/csky-linux:
  csky: Add support for perf unwind-libdw

Restore the kref_get that matches the gss_put_auth(gss_msg->auth)
done by gss_release_msg().

Fixes: ac83228a ("SUNRPC: Use namespace of listening daemon ...")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Now that nfs_match_client drops the nfs_client_lock, we should be
careful
to always return it in the same condition: locked.

Fixes: 950a578c ("NFS: make nfs_match_client killable")
Reported-by: syzbot+228a82b263b5da91883d@syzkaller.appspotmail.com
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>