gcc-8 reports

drivers/gpu/drm/nouveau/nvkm/engine/pm/base.c: In function 'nvkm_perfmon_mthd':
include/linux/string.h:265:9: error: '__builtin_strncpy' specified bound 64 equals destination size [-Werror=stringop-truncation]

We need one less byte or call strlcpy() to make it a
nul-terminated string.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

The kbuild test bot complained about a new coccinelle warning nearby,
which sparked a discussion about the assignment to 'memory' inside of
the conditional expression.  See Link below for the original post.

Fix the assignment to silence the coccinelle warning and also make the
code look a little nicer.

Link: https://lists.freedesktop.org/archives/nouveau/2017-November/029242.htmlSigned-off-by: Christoph Böhmwalder <christoph@boehmwalder.at>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Karol Herbst <kherbst@redhat.com>

Fixes failure to compile with recent envyas as a result of the 'movw'
alias being removed for v5.

A bit of history:

v3 only has a 16-bit sign-extended immediate mov op. In order to set
the high bits, there's a separate 'sethi' op. envyas validates that
the value passed to mov(imm) is between -0x8000 and 0x7fff. In order
to simplify macros that load both the low and high word, a 'movw'
alias was added which takes an unsigned 16-bit immediate. However the
actual hardware op still sign extends.

v5 has a full 32-bit immediate mov op. The v3 16-bit immediate mov op
is gone (loads 0 into the dst reg). However due to a bug in envyas,
the movw alias still existed, and selected the no-longer-present v3
16-bit immediate mov op. As a result usage of movw on v5 is the same
as mov with a 0x0 argument.

The proper fix throughout is to only ever use the 'movw' alias in
combination with 'sethi'. Anything else should get the sign-extended
validation to ensure that the intended value ends up in the
destination register.

Changes in fuc3 binaries is the result of a different encoding being
selected for a mov with an 8-bit value.

v2: added commit message written by Ilia, thanks for that!
v3: messed up rebasing, now it should apply
Signed-off-by: Karol Herbst <kherbst@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

In the past the ast driver relied upon the fbdev emulation helpers to
call ->load_lut at boot-up. But since

commit b8e2b019
Author: Peter Rosin <peda@axentia.se>
Date:   Tue Jul 4 12:36:57 2017 +0200

    drm/fb-helper: factor out pseudo-palette

that's cleaned up and drivers are expected to boot into a consistent
lut state. This patch fixes that.

Fixes: b8e2b019 ("drm/fb-helper: factor out pseudo-palette")
Cc: Peter Rosin <peda@axenita.se>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: <stable@vger.kernel.org> # v4.14+
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=198123
Cc: Bill Fraser <bill.fraser@gmail.com>
Reported-and-Tested-by: Bill Fraser <bill.fraser@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Merge tag 'drm-misc-next-fixes-2018-01-31' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

This contains a fix to restrict what lessee can do with masters and
another one when waiting for timeouts on reservation objects.

* tag 'drm-misc-next-fixes-2018-01-31' of git://anongit.freedesktop.org/drm/drm-misc:
  drm: Check for lessee in DROP_MASTER ioctl
  dma-buf: fix reservation_object_wait_timeout_rcu once more v2

Don't let a lessee control what the current DRM master is set to;
that's the job of the "real" master. Otherwise, the lessee would
disable all access to master operations for the owner and all lessees
under it.

This matches the same check made in the SET_MASTER ioctl.
Signed-off-by: Keith Packard <keithp@keithp.com>
Fixes: 2ed077e4 ("drm: Add drm_object lease infrastructure [v5]")
Cc: <stable@vger.kernel.org> # v4.15+
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180119015159.1606-1-keithp@keithp.com

Merge tag 'drm-misc-next-fixes-2018-01-18' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

Fixes for 4.16:

Fixes one Kconfig issue and a enable some panels to work properly.
There is also a fix of error code return in sun4i.

* tag 'drm-misc-next-fixes-2018-01-18' of git://anongit.freedesktop.org/drm/drm-misc:
  drm: Fix PANEL_ORIENTATION_QUIRKS breaking the Kconfig DRM menuconfig
  drm/panel: lvds: Handle the optional regulator case properly
  drm/sun4i: Fix error code in sun4i_tcon_bind()

 A few more fixes for 4.16, nothing major.

A few more fixes for 4.16.  This is on top of the pull request from
last week.  Most notable change here is a fix to the link order for
the now separate from amdgpu GPU scheduler to fix crashes when the
modules are build into the kernel rather than as modules.

* 'drm-next-4.16' of git://people.freedesktop.org/~agd5f/linux:
  drm: fix gpu scheduler link order
  drm/amd/display: Demote error print to debug print when ATOM impl missing
  drm/amdgpu: Avoid leaking PM domain on driver unbind (v2)
  drm/amd/amdgpu: Add Polaris version check
  drm/amdgpu: Reenable manual GPU reset from sysfs
  drm/amdgpu: disable MMHUB power gating on raven
  drm/ttm: Don't unreserve swapped BOs that were previously reserved
  drm/ttm: Don't add swapped BOs to swap-LRU list
  drm/amdgpu: only check for ECC on Vega10
  drm/amd/powerplay: Fix smu_table_entry.handle type
  drm/ttm: add VADDR_FLAG_UPDATED_COUNT to correctly update dma_page global count
  drm/radeon: fill in rb backend map on evergreen/ni.
  drm/amdgpu/gfx9: fix ngg enablement to clear gds reserved memory (v2)
  drm/ttm: only free pages rather than update global memory count together
  drm/amdgpu: fix CPU based VM updates
  drm/amdgpu: fix typo in amdgpu_vce_validate_bo
  drm/amdgpu: fix amdgpu_vm_pasid_fault_credit
  drm/ttm: check the return value of register_shrinker
  drm/radeon: fix sparse warning: Should it be static?

It should initialize before the drivers using it.
Signed-off-by: Christian König <christian.koenig@amd.com>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=104736Reviewed-by: Mike Lothian <mike@fireburn.co.uk>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

I assumed wrongfully that all relevant functions should be implemented.
Apparently this isn't the case. Demote the print to debug level for now.
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

We need to set shared_count even if we already have a fence to wait for.

v2: init i to -1 as well
Signed-off-by: Christian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org
Tested-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180122200003.6665-1-christian.koenig@amd.com

We only support vga_switcheroo and runtime pm on PX/HG systems
so forcing runpm to 1 doesn't do anything useful anyway.

Only call vga_switcheroo_init_domain_pm_ops() for PX/HG so
that the cleanup path is correct as well.  This mirrors what
radeon does as well.

v2: rework the patch originally sent by Lukas (Alex)
Acked-by: Lukas Wunner <lukas@wunner.de>
Reported-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de> (v1)
Cc: stable@vger.kernel.org

Add Polaris version check if firmware support UVD encode
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: James Zhu <James.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

Otherwise it keeps rejecting the reset.
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

MMHUB power gating still has issue, and doesn't work on raven at current. So
disable it for the moment.
Signed-off-by: Huang Rui <ray.huang@amd.com>
Acked-by: Hawking Zhang <Hawking.Zhang@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

If ttm_bo_swapout doesn't own the lock, don't release it. Someone
else probably depends on it still being locked.
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

A BO that's already swapped would be added back to the swap-LRU list
for example if its validation failed under high memory pressure. This
could later lead to swapping it out again and leaking previous swap
storage.

This commit adds a condition to prevent that from happening.

v2: Check page_flags instead of swap_storage
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

RV doesn't support it.
Reviewed-by: Junwei Zhang <Jerry.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

The handle describes kernel logical address, should be
unsigned long and not uint32_t.
Fixes KASAN error and GFP on driver unload.
Reviewed-by: Rex Zhu <Rex.Zhu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

add this for correctly updating global mem count in ttm_mem_zone.
before that when ttm_mem_global_alloc_page fails, we would update all
dma_page's global mem count in ttm_dma->pages_list. but actually here
we should not update for the last dma_page.

v2: only the update of last dma_page is not right
v3: use lower bits of dma_page vaddr
Signed-off-by: Roger He <Hongbo.He@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Merge tag 'drm-amdkfd-next-fixes-2018-01-15' of git://people.freedesktop.org/~gabbayo/linux into drm-next

- fix NULL pointer dereference
- fix compiler warning on large define values
- remove unnecessary call to execute_queues_cpsch

* tag 'drm-amdkfd-next-fixes-2018-01-15' of git://people.freedesktop.org/~gabbayo/linux:
  drm/amdkfd: Fix potential NULL pointer dereferences
  drm/amdkfd: add ull suffix to 64bit defines
  drm/amdkfd: don't always call execute_queues_cpsch()
  drm/amdkfd: Fix return value 0 when execute_queues_cpsch fails

Linux 4.15-rc8

Daniel requested this for so the intel CI won't fall over on drm-next
so often.

All Kconfig menu menu entries should have a depends on MENU_OPTION, the
menu stops after the first Kconfig entry without this depends on.

Since the PANEL_ORIENTATION_QUIRKS option is also used outside of DRM,
it deliberately does not have a depends on DRM, but this causes all
items after it to show as separate items rather then under the DRM
menuconfig.

This commit moves PANEL_ORIENTATION_QUIRKS to the end of the drm Kconfig
file, grouping it with DRM_LIB_RANDOM which also does not depend on DRM,
fixing the DRM menuconfig.

Fixes: 404d1a3e ("drm: Add panel orientation quirks, v6.")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180117081032.6411-1-hdegoede@redhat.com

This looks to have never gotten filled in, and it seems to
 trigger a bug in mesa.
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Reported-by: Roland Scheidegger <sroland@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

v2: fix register access
Signed-off-by: Junwei Zhang <Jerry.Zhang@amd.com>
Reviewed-by: Ken Wang <ken.wang@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

if ttm_get_pages or ttm_mem_global_alloc_page fail, should not update
global memory count.
Signed-off-by: Roger He <Hongbo.He@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Tested-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Acked-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

That got accidentially removed.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Otherwise buffer placement is very restrictive and might fail.

Fixes: "drm/amdgpu: fix VCE buffer placement restrictions v2"
Signed-off-by: Christian König <christian.koenig@amd.com>
Reported-by: Deng, Emily <Emily.Deng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

As soon as the lock is dropped the VM pointer can be invalid.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

This fixes the build warning:
"ignoring return value of 'register_shrinker', declared with
attribute warn_unused_result [-Wunused-result]"
Signed-off-by: Roger He <Hongbo.He@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Impact: make symbol static.

Fix this sparse warning:
  drivers/gpu/drm/radeon/radeon_dp_mst.c:332:38: warning: symbol 'mst_cbs' was not declared. Should it be static?
Signed-off-by: Dmitry Rozhkov <dmitry.rozhkov@linux.intel.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

The devm_regulator_get_optional function, unlike it was assumed in the
commit a1c55bcc ("drm/panel: lvds: Add support for the power-supply
property"), is actually returning an error pointer with -ENODEV instead of
NULL when there's no regulator to find.

Make sure we handle that case properly.
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Fixes: a1c55bcc ("drm/panel: lvds: Add support for the power-supply property")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180110155941.16109-1-maxime.ripard@free-electrons.com

We accidentally passed the wrong variable to PTR_ERR().

Fixes: a0c1214e ("drm/sun4i: Add LVDS support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180115081113.wlam5wkmdynisf4r@mwanda

Pull x86 fixlet from Thomas Gleixner.

Remove a warning about lack of compiler support for retpoline that most
people can't do anything about, so it just annoys them needlessly.

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/retpoline: Remove compile time warning

Pull powerpc fixes from Michael Ellerman:
 "One fix for an oops at boot if we take a hotplug interrupt before we
  are ready to handle it.

  The bulk is patches to implement mitigation for Meltdown, see the
  change logs for more details.

  Thanks to: Nicholas Piggin, Michael Neuling, Oliver O'Halloran, Jon
  Masters, Jose Ricardo Ziviani, David Gibson"

* tag 'powerpc-4.15-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/powernv: Check device-tree for RFI flush settings
  powerpc/pseries: Query hypervisor for RFI flush settings
  powerpc/64s: Support disabling RFI flush with no_rfi_flush and nopti
  powerpc/64s: Add support for RFI flush of L1-D cache
  powerpc/64s: Convert slb_miss_common to use RFI_TO_USER/KERNEL
  powerpc/64: Convert fast_exception_return to use RFI_TO_USER/KERNEL
  powerpc/64: Convert the syscall exit path to use RFI_TO_USER/KERNEL
  powerpc/64s: Simple RFI macro conversions
  powerpc/64: Add macros for annotating the destination of rfid/hrfid
  powerpc/pseries: Add H_GET_CPU_CHARACTERISTICS flags & wrapper
  powerpc/pseries: Make RAS IRQ explicitly dependent on DLPAR WQ

Remove the compile time warning when CONFIG_RETPOLINE=y and the compiler
does not have retpoline support. Linus rationale for this is:

  It's wrong because it will just make people turn off RETPOLINE, and the
  asm updates - and return stack clearing - that are independent of the
  compiler are likely the most important parts because they are likely the
  ones easiest to target.

  And it's annoying because most people won't be able to do anything about
  it. The number of people building their own compiler? Very small. So if
  their distro hasn't got a compiler yet (and pretty much nobody does), the
  warning is just annoying crap.

  It is already properly reported as part of the sysfs interface. The
  compile-time warning only encourages bad things.

Fixes: 76b04384 ("x86/retpoline: Add initial retpoline support")
Requested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: thomas.lendacky@amd.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Link: https://lkml.kernel.org/r/CA+55aFzWgquv4i6Mab6bASqYXg3ErV3XDFEYf=GEcCDQg5uAtw@mail.gmail.com

Pull NVMe fix from Jens Axboe:
 "Just a single fix for nvme over fabrics that should go into 4.15"

* 'for-linus' of git://git.kernel.dk/linux-block:
  nvme-fabrics: initialize default host->id in nvmf_host_default()

Pull x86 pti updates from Thomas Gleixner:
 "This contains:

   - a PTI bugfix to avoid setting reserved CR3 bits when PCID is
     disabled. This seems to cause issues on a virtual machine at least
     and is incorrect according to the AMD manual.

   - a PTI bugfix which disables the perf BTS facility if PTI is
     enabled. The BTS AUX buffer is not globally visible and causes the
     CPU to fault when the mapping disappears on switching CR3 to user
     space. A full fix which restores BTS on PTI is non trivial and will
     be worked on.

   - PTI bugfixes for EFI and trusted boot which make sure that the user
     space visible page table entries have the NX bit cleared

   - removal of dead code in the PTI pagetable setup functions

   - add PTI documentation

   - add a selftest for vsyscall to verify that the kernel actually
     implements what it advertises.

   - a sysfs interface to expose vulnerability and mitigation
     information so there is a coherent way for users to retrieve the
     status.

   - the initial spectre_v2 mitigations, aka retpoline:

      + The necessary ASM thunk and compiler support

      + The ASM variants of retpoline and the conversion of affected ASM
        code

      + Make LFENCE serializing on AMD so it can be used as speculation
        trap

      + The RSB fill after vmexit

   - initial objtool support for retpoline

  As I said in the status mail this is the most of the set of patches
  which should go into 4.15 except two straight forward patches still on
  hold:

   - the retpoline add on of LFENCE which waits for ACKs

   - the RSB fill after context switch

  Both should be ready to go early next week and with that we'll have
  covered the major holes of spectre_v2 and go back to normality"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (28 commits)
  x86,perf: Disable intel_bts when PTI
  security/Kconfig: Correct the Documentation reference for PTI
  x86/pti: Fix !PCID and sanitize defines
  selftests/x86: Add test_vsyscall
  x86/retpoline: Fill return stack buffer on vmexit
  x86/retpoline/irq32: Convert assembler indirect jumps
  x86/retpoline/checksum32: Convert assembler indirect jumps
  x86/retpoline/xen: Convert Xen hypercall indirect jumps
  x86/retpoline/hyperv: Convert assembler indirect jumps
  x86/retpoline/ftrace: Convert ftrace assembler indirect jumps
  x86/retpoline/entry: Convert entry assembler indirect jumps
  x86/retpoline/crypto: Convert crypto assembler indirect jumps
  x86/spectre: Add boot time option to select Spectre v2 mitigation
  x86/retpoline: Add initial retpoline support
  objtool: Allow alternatives to be ignored
  objtool: Detect jumps to retpoline thunks
  x86/pti: Make unpoison of pgd for trusted boot work for real
  x86/alternatives: Fix optimize_nops() checking
  sysfs/cpu: Fix typos in vulnerability documentation
  x86/cpu/AMD: Use LFENCE_RDTSC in preference to MFENCE_RDTSC
  ...

The intel_bts driver does not use the 'normal' BTS buffer which is exposed
through the cpu_entry_area but instead uses the memory allocated for the
perf AUX buffer.

This obviously comes apart when using PTI because then the kernel mapping;
which includes that AUX buffer memory; disappears. Fixing this requires to
expose a mapping which is visible in all context and that's not trivial.

As a quick fix disable this driver when PTI is enabled to prevent
malfunction.

Fixes: 385ce0ea ("x86/mm/pti: Add Kconfig")
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Reported-by: Robert Święcki <robert@swiecki.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: greg@kroah.com
Cc: hughd@google.com
Cc: luto@amacapital.net
Cc: Vince Weaver <vince@deater.net>
Cc: torvalds@linux-foundation.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180114102713.GB6166@worktop.programming.kicks-ass.net