This reverts commit 22083c02 which is
commit 4abb951b73ff0a8a979113ef185651aa3c8da19b upstream.

Jean writes:

	This commit was tagged with:

	    Link: https://bugzilla.kernel.org/show_bug.cgi?id=200011
	    Tested-by: Jean-Marc Lenoir
	    Cc: All applicable <stable@vger.kernel.org>

	making it sound like it was fixing an actual bug. This is not the case.
	The commit fixes a side issue discovered while investigating bug
	#200011. It does NOT fix bug #200011 itself (as explicitly reported by
	Jean-Marc at https://bugzilla.kernel.org/show_bug.cgi?id=200011#c65 ).

	It does however cause regressions, despite what the commit message says. See:

	https://bugzilla.kernel.org/show_bug.cgi?id=201721

	and I expect more similar regressions, as ACPI resource conflicts are
	very frequent.

	This commit was not stable material to start with. It is intrusive,
	presents a risk of side effects, and does not solve an actual bug that
	is bothering users.
Reported-by: NJean Delvare <jdelvare@suse.de>
Cc: Jean-Marc Lenoir <archlinux@jihemel.com>
Cc: Erik Schmauss <erik.schmauss@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit f9005571701920551bcf54a500973fb61f2e1eda upstream.

xen_create_contiguous_region has now only an implementation if
CONFIG_XEN_PV is defined. However, on ARM we never set CONFIG_XEN_PV but
we do have an implementation of xen_create_contiguous_region which is
required for swiotlb-xen to work correctly (although it just sets
*dma_handle).

[backport: remove change to xen_remap_pfn]

Cc: <stable@vger.kernel.org> # 4.12
Fixes: 16624390 ("xen: create xen_create/destroy_contiguous_region() stubs for PVHVM only builds")
Signed-off-by: NStefano Stabellini <stefanos@xilinx.com>
Reviewed-by: NJuergen Gross <jgross@suse.com>
CC: Jeff.Kubascik@dornerworks.com
CC: Jarvis.Roach@dornerworks.com
CC: Nathan.Studer@dornerworks.com
CC: vkuznets@redhat.com
CC: boris.ostrovsky@oracle.com
CC: jgross@suse.com
CC: julien.grall@arm.com
Signed-off-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 44a7276b30c3c15f2b7790a5729640597fb6a1df upstream.

In my haste to remove irq_port[] I accidentally changed the
way we deal with hpd pins that are shared by multiple encoders
(DP and HDMI for pre-DDI platforms). Previously we would only
handle such pins via ->hpd_pulse(), but now we queue up the
hotplug work for the HDMI encoder directly. Worse yet, we now
count each hpd twice and this increment the hpd storm count
twice as fast. This can lead to spurious storms being detected.

Go back to the old way of doing things, ie. delegate to
->hpd_pulse() for any pin which has an encoder with that hook
implemented. I don't really like the idea of adding irq_port[]
back so let's loop through the encoders first to check if we
have an encoder with ->hpd_pulse() for the pin, and then go
through all the pins and decided on the correct course of action
based on the earlier findings.

I have occasionally toyed with the idea of unifying the pre-DDI
HDMI and DP encoders into a single encoder as well. Besides the
hotplug processing it would have the other benefit of preventing
userspace from trying to enable both encoders at the same time.
That is simply illegal as they share the same clock/data pins.
We have some testcases that will attempt that and thus fail on
many older machines. But for now let's stick to fixing just the
hotplug code.

Cc: stable@vger.kernel.org # 4.19+
Cc: Lyude Paul <lyude@redhat.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Fixes: b6ca3eee ("drm/i915: Nuke dev_priv->irq_port[]")
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181108200424.28371-1-ville.syrjala@linux.intel.comReviewed-by: NLyude Paul <lyude@redhat.com>
(cherry picked from commit 5a3aeca97af1b6b3498d59a7fd4e8bb95814c108)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 541ff7e96c13cd5d67f6021d233f8e1c3df49278 upstream.

Turns out that if you trigger an HPD storm on a system that has an MST
topology connected to it, you'll end up causing the kernel to eventually
hit a NULL deref:

[  332.339041] BUG: unable to handle kernel NULL pointer dereference at 00000000000000ec
[  332.340906] PGD 0 P4D 0
[  332.342750] Oops: 0000 [#1] SMP PTI
[  332.344579] CPU: 2 PID: 25 Comm: kworker/2:0 Kdump: loaded Tainted: G           O      4.18.0-rc3short-hpd-storm+ #2
[  332.346453] Hardware name: LENOVO 20BWS1KY00/20BWS1KY00, BIOS JBET71WW (1.35 ) 09/14/2018
[  332.348361] Workqueue: events intel_hpd_irq_storm_reenable_work [i915]
[  332.350301] RIP: 0010:intel_hpd_irq_storm_reenable_work.cold.3+0x2f/0x86 [i915]
[  332.352213] Code: 00 00 ba e8 00 00 00 48 c7 c6 c0 aa 5f a0 48 c7 c7 d0 73 62 a0 4c 89 c1 4c 89 04 24 e8 7f f5 af e0 4c 8b 04 24 44 89 f8 29 e8 <41> 39 80 ec 00 00 00 0f 85 43 13 fc ff 41 0f b6 86 b8 04 00 00 41
[  332.354286] RSP: 0018:ffffc90000147e48 EFLAGS: 00010006
[  332.356344] RAX: 0000000000000005 RBX: ffff8802c226c9d4 RCX: 0000000000000006
[  332.358404] RDX: 0000000000000000 RSI: 0000000000000082 RDI: ffff88032dc95570
[  332.360466] RBP: 0000000000000005 R08: 0000000000000000 R09: ffff88031b3dc840
[  332.362528] R10: 0000000000000000 R11: 000000031a069602 R12: ffff8802c226ca20
[  332.364575] R13: ffff8802c2268000 R14: ffff880310661000 R15: 000000000000000a
[  332.366615] FS:  0000000000000000(0000) GS:ffff88032dc80000(0000) knlGS:0000000000000000
[  332.368658] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  332.370690] CR2: 00000000000000ec CR3: 000000000200a003 CR4: 00000000003606e0
[  332.372724] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  332.374773] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  332.376798] Call Trace:
[  332.378809]  process_one_work+0x1a1/0x350
[  332.380806]  worker_thread+0x30/0x380
[  332.382777]  ? wq_update_unbound_numa+0x10/0x10
[  332.384772]  kthread+0x112/0x130
[  332.386740]  ? kthread_create_worker_on_cpu+0x70/0x70
[  332.388706]  ret_from_fork+0x35/0x40
[  332.390651] Modules linked in: i915(O) vfat fat joydev btusb btrtl btbcm btintel bluetooth ecdh_generic iTCO_wdt wmi_bmof i2c_algo_bit drm_kms_helper intel_rapl syscopyarea sysfillrect x86_pkg_temp_thermal sysimgblt coretemp fb_sys_fops crc32_pclmul drm psmouse pcspkr mei_me mei i2c_i801 lpc_ich mfd_core i2c_core tpm_tis tpm_tis_core thinkpad_acpi wmi tpm rfkill video crc32c_intel serio_raw ehci_pci xhci_pci ehci_hcd xhci_hcd [last unloaded: i915]
[  332.394963] CR2: 00000000000000ec

This appears to be due to the fact that with an MST topology, not all
intel_connector structs will have ->encoder set. So, fix this by
skipping connectors without encoders in
intel_hpd_irq_storm_reenable_work().

For those wondering, this bug was found on accident while simulating HPD
storms using a Chamelium connected to a ThinkPad T450s (Broadwell).

Changes since v1:
- Check intel_connector->mst_port instead of intel_connector->encoder
Signed-off-by: NLyude Paul <lyude@redhat.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Cc: stable@vger.kernel.org
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181106213017.14563-3-lyude@redhat.com
(cherry picked from commit fee61deecb1d850bf34f682a6a452e5ee51b7572)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 7c4512300cfa5a4dcc8c1c52ae61e3fa4bd11a39 upstream.

This hasn't caused any issues yet that I'm aware of, but as Ville
Syrjälä pointed out - we need to make sure that
intel_connector->mst_port is set before initializing MST connectors,
since in theory we could potentially check intel_connector->mst_port in
i915_hpd_poll_init_work() after registering the connector but before
having written it's value.
Signed-off-by: NLyude Paul <lyude@redhat.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: stable@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20181106213017.14563-2-lyude@redhat.com
(cherry picked from commit 66a5ab1034be801630816d1fa6cfc30db1a2f0b0)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 0a823e8fd4fd67726697854578f3584ee3a49b1d upstream.

Ensure that the writes into the context image are completed prior to the
register mmio to trigger execution. Although previously we were assured
by the SDM that all writes are flushed before an uncached memory
transaction (our mmio write to submit the context to HW for execution),
we have empirical evidence to believe that this is not actually the
case.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108656
References: https://bugs.freedesktop.org/show_bug.cgi?id=108315
References: https://bugs.freedesktop.org/show_bug.cgi?id=106887Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Acked-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181108081740.25615-1-chris@chris-wilson.co.uk
Cc: stable@vger.kernel.org
(cherry picked from commit 987abd5c62f92ee4970b45aa077f47949974e615)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit fb5bbae9b1333d44023713946fdd28db0cd85751 upstream.

Exercising the gpu reloc path strenuously revealed an issue where the
updated relocations (from MI_STORE_DWORD_IMM) were not being observed
upon execution. After some experiments with adding pipecontrols (a lot
of pipecontrols (32) as gen4/5 do not have a bit to wait on earlier pipe
controls or even the current on), it was discovered that we merely
needed to delay the EMIT_INVALIDATE by several flushes. It is important
to note that it is the EMIT_INVALIDATE as opposed to the EMIT_FLUSH that
needs the delay as opposed to what one might first expect -- that the
delay is required for the TLB invalidation to take effect (one presumes
to purge any CS buffers) as opposed to a delay after flushing to ensure
the writes have landed before triggering invalidation.

Testcase: igt/gem_tiled_fence_blits
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181105094305.5767-1-chris@chris-wilson.co.uk
(cherry picked from commit 55f99bf2a9c331838c981694bc872cd1ec4070b2)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 0014868b9c3c1dda1de6711cf58c3486fb422d07 upstream.

Since the flags are being used to operate on a u64 variable, they too
need to be marked as such so that the inverses are full width (and not
zero extended on 32b kernels and bdw+).
Reported-by: NSergii Romantsov <sergii.romantsov@globallogic.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
Reviewed-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181102161232.17742-2-chris@chris-wilson.co.uk
(cherry picked from commit 83b466b1dc5f0b4d33f0a901e8b00197a8f3582d)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 6a8915d0f8cf323e1beb792a33095cf652db4056 upstream.

We deinit the lpe audio device before we call
drm_atomic_helper_shutdown(), which means the platform device
may already be gone when it comes time to shut down the crtc.
As we don't know when the last reference to the platform
device gets dropped by the audio driver we can't assume that
the device and its data are still around when turning off the
crtc. Mark the platform device as gone as soon as we do the
audio deinit.

Cc: stable@vger.kernel.org
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181105194604.6994-1-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
(cherry picked from commit f45a7977d1140c11f334e01a9f77177ed68e3bfa)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 085603287452fc96376ed4888bf29f8c095d2b40 upstream.

Beware mixing unsigned long constants and 64b values, as on 32b the
constant will be zero extended and discard the high 32b when used as
a mask!
Reported-by: NSergii Romantsov <sergii.romantsov@globallogic.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108282Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181025091823.20571-2-chris@chris-wilson.co.uk
(cherry picked from commit 6fc4e48f9ed46e9adff236a0c350074aafa3b7fa)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit df5e31c204b34e8d9e5ec33f5b28e960c4f25e14 upstream.

We're no longer programming any watermarks when we're disabling
a pipe. That means ilk_wm_merge() & co. will keep considering
the any pipe that is getting disabled as still enabled. Thus we
either get no LP1+ watermakrs (ilk-ivb), or we get suboptimal
ones (hsw-bdw).

This seems to have been broken by commit b6b178a7 ("drm/i915:
Calculate ironlake intermediate watermarks correctly, v2."). Before
that we apparently had some difference between the intermediate
and optimal watermarks and so we would program the optiomal ones.
Now intermediate and optimal are identical for disabled pipes
and so we don't program either.

Fix this by programming the intermediate watermarks even for
disabled pipes. We were already doing that for skl+. We'll
leave out gmch platforms for now since those do the merging
in a different manner and should work as is. We'll want to
unify this eventually, but play it safe for now and just put
in a FIXME.

Cc: stable@vger.kernel.org
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Fixes: b6b178a7 ("drm/i915: Calculate ironlake intermediate watermarks correctly, v2.")
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181025130536.29024-1-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> #irc
(cherry picked from commit a748faea3bfd7fd1d1485bc1c426c7d460cc6503)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit f42f343887016330b321dd40eebc68c7292e4f1b upstream.

Let's not leak obj->framebuffer_references when we decide that
the framebuffer domensions are not suitable for NV12.

Cc: stable@vger.kernel.org
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Vidya Srinivas <vidya.srinivas@intel.com>
Fixes: e44134f2 ("drm/i915: Add NV12 support to intel_framebuffer_init")
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181029140031.11765-1-ville.syrjala@linux.intel.comReviewed-by: NMatt Roper <matthew.d.roper@intel.com>
(cherry picked from commit 3b90946fcb6f13b65888c380461793a9dea9d1f4)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c58281056a8b26d5d9dc15c19859a7880835ef44 upstream.

Since we use a 64b virtual GTT irrespective of the system, we want to
ensure that the GTT computations remains 64b even on 32b systems,
including treatment of huge virtual pages.

No code generation changes on 64b:
Reported-by: NSergii Romantsov <sergii.romantsov@globallogic.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108282Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181025091823.20571-1-chris@chris-wilson.co.uk
(cherry picked from commit 9125963a9494253fa5a29cc1b4169885d2be7042)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 6503493145cba4413ecd3d4d153faeef4a1e9b85 upstream.

HDMI 2.0 594Mhz modes were incorrectly selecting 25.200Mhz Automatic N value
mode instead of HDMI specification values.

V2: Fix 88.2 Hz N value

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NClint Taylor <clinton.a.taylor@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1540493521-1746-2-git-send-email-clinton.a.taylor@intel.com
(cherry picked from commit 5a400aa3c562c4a726b4da286e63c96db905ade1)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit e528c2affcf216b3d02b22004895cb678769629b upstream.

This patch fixes the macros used for defining the DFLEXDPMLE
register bit fields. This accounts for changes in the spec.

Fixes: a2bc69a1 ("drm/i915/icl: Add register definition for DFLEXDPMLE")
Cc: Animesh Manna <animesh.manna@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Jose Roberto de Souza <jose.souza@intel.com>
Cc: <stable@vger.kernel.org> # v4.19+
Signed-off-by: NManasi Navare <manasi.d.navare@intel.com>
Reviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181023191248.26418-1-manasi.d.navare@intel.com
(cherry picked from commit b4335ec0a3ee6229a570755f8fb95dc8a7c694f2)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit f9776280c29e77a18cbc7ebb6d48f7885e494990 upstream.

Commit '3cf71bc9904d ("drm/i915: Re-apply "Perform link quality check,
unconditionally during long pulse"")' applies a work around for sinks
that don't signal link loss. The work around does not need to have to be
that broad as the issue was seen with only one particular monitor; limit
this only for external displays as eDP features like PSR turn off the link
and the driver ends up retraining the link seeeing that link is not
synchronized.

Cc: Lyude Paul <lyude@redhat.com>
Cc: Jan-Marek Glogowski <glogow@fbihome.de>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
References: 3cf71bc9904d ("drm/i915: Re-apply "Perform link quality check, unconditionally during long pulse"")
Signed-off-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180927205735.16651-2-dhinakaran.pandiyan@intel.com
(cherry picked from commit f24f6eb95807bca0dbd8dc5b2f3a4099000f4472)
Fixes: 39933470 ("drm/i915: Re-apply "Perform link quality check, unconditionally during long pulse"")
Cc: stable@vger.kernel.org
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 49af5d95b9b3c21a84ad115a9db9acbc036d849a upstream.

Comment claims link needs to be retrained because the connected sink raised
a long pulse to indicate link loss. If the sink did so,
intel_dp_hotplug() would have handled link retraining. Looking at the
logs in Bugzilla referenced in commit '3cf71bc9904d ("drm/i915: Re-apply
Perform link quality check, unconditionally during long pulse"")', the
issue is that the sink does not trigger an interrupt. What we want is
->detect() from user space to check link status and retrain. Ville's
review for the original patch also indicates the same root cause. So,
rewrite the comment.

v2: Patch split and rewrote comment.

Cc: Lyude Paul <lyude@redhat.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Jan-Marek Glogowski <glogow@fbihome.de>
References: 3cf71bc9904d ("drm/i915: Re-apply "Perform link quality check, unconditionally during long pulse"")
Signed-off-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180927205735.16651-1-dhinakaran.pandiyan@intel.com
(cherry picked from commit 9ebd8202393dde9d3678c9ec162c1aa63ba17eac)
Fixes: 39933470 ("drm/i915: Re-apply "Perform link quality check, unconditionally during long pulse"")
Cc: stable@vger.kernel.org
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit ab0d6a141843e0b4b2709dfd37b53468b5452c3a upstream.

Handle integer overflow when computing the sub-page length for shmem
backed pread/pwrite.
Reported-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181012140228.29783-1-chris@chris-wilson.co.uk
(cherry picked from commit a5e856a5348f6cd50889d125c40bbeec7328e466)
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c02ba4ef16eefe663fdefcccaa57fad32d5481bf upstream.

Since we need to be able to allow DPMS on->off prop changes after an MST
port has disappeared from the system, we need to be able to make sure we
can compute a config for the resulting atomic commit. Currently this is
impossible when the port has disappeared, since the VCPI slot searching
we try to do in intel_dp_mst_compute_config() will fail with -EINVAL.

Since the only commits we want to allow on no-longer-present MST ports
are ones that shut off display hardware, we already know that no VCPI
allocations are needed. So, hardcode the VCPI slot count to 0 when
intel_dp_mst_compute_config() is called on an MST port that's gone.

Changes since V4:
- Don't use mst_port_gone at all, just check whether or not the drm
  connector is registered - Daniel Vetter
Signed-off-by: NLyude Paul <lyude@redhat.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20181008232437.5571-5-lyude@redhat.com
(cherry picked from commit f67207d78ceaf98b7531bc22df6f21328559c8d4)
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 80c188695a77eddaa6e8885510ff4ef59fd478c3 upstream.

Currently we set intel_connector->mst_port to NULL to signify that the
MST port has been removed from the system so that we can prevent further
action on the port such as connector probes, mode probing, etc.
However, we're going to need access to intel_connector->mst_port in
order to fixup ->best_encoder() so that it can always return the correct
encoder for an MST port to prevent legacy DPMS prop changes from
failing. This should be safe, so instead keep intel_connector->mst_port
always set and instead just check the status of
drm_connector->regustered to signify whether or not the connector has
disappeared from the system.

Changes since v2:
- Add a comment to mst_port_gone (Jani Nikula)
- Change mst_port_gone to a u8 instead of a bool, per the kernel bot.
  Apparently bool is discouraged in structs these days
Changes since v4:
- Don't use mst_port_gone at all! Just check if the connector is
  registered or not - Daniel Vetter
Signed-off-by: NLyude Paul <lyude@redhat.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20181008232437.5571-4-lyude@redhat.com
(cherry picked from commit 6ed5bb1fbad34382c8cfe9a9bf737e9a43053df5)
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 7cada4d0b7a0fb813dbc9777fec092e9ed0546e9 upstream.

Plane sanitation needs vblank interrupts (on account of CxSR disable).
So let's restore vblank interrupts earlier.

v2: Make it actually build
v3: Add comment to explain why we need this (Daniel)

Cc: stable@vger.kernel.org
Cc: Dennis <dennis.nezic@utoronto.ca>
Tested-by: NDennis <dennis.nezic@utoronto.ca>
Tested-by: NPeter Nowee <peter.nowee@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105637
Fixes: b1e01595 ("drm/i915: Redo plane sanitation during readout")
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20181003144951.4397-1-ville.syrjala@linux.intel.com
(cherry picked from commit 68bc30deac625b8be8d3950b30dc93d09a3645f5)
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 9b27390139dbe0dc10d1899545248862fe826b61 upstream.

When we decide that a plane is attached to the wrong pipe we try
to turn off said plane. However we are passing around the crtc we
think that the plane is supposed to be using rather than the crtc
it is currently using. That doesn't work all that well because
we may have to do vblank waits etc. and the other pipe might
not even be enabled here. So let's pass the plane's current crtc to
intel_plane_disable_noatomic() so that it can its job correctly.

To do that semi-cleanly we also have to change the plane readout
to record the plane's visibility into the bitmasks of the crtc
where the plane is currently enabled rather than to the crtc
we want to use for the plane.

One caveat here is that our active_planes bitmask will get confused
if both planes are enabled on the same pipe. Fortunately we can use
plane_mask to reconstruct active_planes sufficiently since
plane_mask still has the same meaning (is the plane visible?)
during readout. We also have to do the same during the initial
plane readout as the second plane could clear the active_planes
bit the first plane had already set.

v2: Rely on fixup_active_planes() to populate active_planes fully (Daniel)
    Add Daniel's proposed comment to better document why we do this
    Drop the redundant intel_set_plane_visible() call

Cc: stable@vger.kernel.org # fcba862e8428 drm/i915: Have plane->get_hw_state() return the current pipe
Cc: stable@vger.kernel.org
Cc: Dennis <dennis.nezic@utoronto.ca>
Cc: Daniel Vetter <daniel@ffwll.ch>
Tested-by: NDennis <dennis.nezic@utoronto.ca>
Tested-by: NPeter Nowee <peter.nowee@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105637
Fixes: b1e01595 ("drm/i915: Redo plane sanitation during readout")
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181003145017.4527-1-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
(cherry picked from commit 62358aa4ee86481ce044bef04859820e1bc7c1d9)
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 041444458835d7fb2c9f042598bfe16bf375b15d upstream.

This patch fixes the original commit c0cfb10d ("drm/i915/edp:
Do not do link training fallback or prune modes on EDP") that causes
a blank screen in case of certain eDP panels (Eg: seen on Dell XPS13 9350)
where first link training fails and a retraining is required by falling
back to lower link rate/lane count.
In case of some panels they advertise higher link rate/lane count
than whats required for supporting the panel's native mode.
But we always link train at highest link rate/lane count for eDP
and if that fails we can still fallback to lower link rate/lane count
as long as the fallback link BW still fits the native mode to avoid
pruning the panel's native mode yet retraining at fallback values
to recover from a blank screen.

v3:
* Add const for fixed_mode (Ville)
v2:
* Send uevent if link failure on eDP unconditionally

Fixes: c0cfb10d ("drm/i915/edp: Do not do link training fallback or prune modes on EDP")
Cc: Clinton Taylor <clinton.a.taylor@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: <stable@vger.kernel.org> # v4.17+
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107489
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105338Signed-off-by: NManasi Navare <manasi.d.navare@intel.com>
Tested-by: NAlexander Wilson <alexander.wilson@ncf.edu>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181009212804.702-1-manasi.d.navare@intel.com
(cherry picked from commit 1e712535c51ab025ebc776d4405683d81521996d)
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 0e8afefd5da4875ddea9aa4ad17a2540a2bf9736 upstream.

The Acer One 10 uses a clamshell design with a detachable keyboard.
As such in normal operating mode, with the keyboard attach the device
is in landscape mode (and the Acer logo at boot also shows in landscape
mode).

But the device uses a portrait screen rotated 90 degrees (sigh). This
commit adds a quirk for this device so that we shown the fbcon the
right way up and that we hint userspace to also show e.g. plymouth and
gdm the right way up.

Cc: stable@vger.kernel.org
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181012101610.29100-1-hdegoede@redhat.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 23d8003907d094f77cf959228e2248d6db819fa7 upstream.

Unfortunately drm_dp_get_mst_branch_device which is called from both
drm_dp_mst_handle_down_rep and drm_dp_mst_handle_up_rep seem to rely
on that mgr->mst_primary is not NULL, which seem to be wrong as it can be
cleared with simultaneous mode set, if probing fails or in other case.
mgr->lock mutex doesn't protect against that as it might just get
assigned to NULL right before, not simultaneously.

There are currently bugs 107738, 108616 bugs which crash in
drm_dp_get_mst_branch_device, caused by this issue.

v2: Refactored the code, as it was nicely noticed.
    Fixed Bugzilla bug numbers(second was 108616, but not 108816)
    and added links.

[changed title and added stable cc]
Signed-off-by: NLyude Paul <lyude@redhat.com>
Signed-off-by: NStanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Cc: stable@vger.kernel.org
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108616
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107738
Link: https://patchwork.freedesktop.org/patch/msgid/20181109090012.24438-1-stanislav.lisovskiy@intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 6fce3a406108ee6c8a61e2a33e52e9198a626ea0 upstream.

The GPU hardware fences and the job out-fences are on different timelines
so it's wrong to compare them. Fix this by only looking at the out-fence.

Cc: <stable@vger.kernel.org>
Fixes: 2c83a726 (drm/etnaviv: bring back progress check in job
                     timeout handler)
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 51ef434a15b450bfbef1e06cc87ee4e98a224486 upstream.

We observe black lines (underflow) on display when playing a
4K video with UVD. On Disabling Low memory P state this issue is
not seen.
Multiple runs of power measurement shows no imapct.
Signed-off-by: NAkshu Agrawal <akshu.agrawal@amd.com>
Signed-off-by: NSatyajit Sahu <satyajit.sahu@amd.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 7b0f61e91b6056c71649efa3204112a4b6cf5fc8 upstream.

As mentioned in the previous commit, we currently prevent new modesets
on recently-removed MST connectors by returning no encoder from our
->best_encoder() callback once the MST port has disappeared. This is
wrong however, because it prevents legacy modesetting users from being
able to disable CRTCs on MST connectors after the connector's respective
topology has disappeared.

So, fix this by instead by just always returning a valid encoder.

Changes since v2:
- Remove usage of atomic MST helper for now, since that got replaced
  with a much simpler solution
Signed-off-by: NLyude Paul <lyude@redhat.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NBen Skeggs <bskeggs@redhat.com>
Cc: stable@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20181008232437.5571-3-lyude@redhat.com
(cherry picked from commit e87b0bbc9f0380d403f8f2f6abba0d51c74d944f)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit dc854914999d5d52ac1b31740cb0ea8d89d0372e upstream.

Remember, ida IDs start at 0, not 1!
Signed-off-by: NLyude Paul <lyude@redhat.com>
Reviewed-by: NKarol Herbst <kherbst@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 582f58de36834096a91cc1de2540c2f7269f850d upstream.

Currently we return NOTIFY_DONE for any event which we don't think is
ours. However, many laptops will send more then just an ATIF event and
will also send an ACPI_VIDEO_NOTIFY_PROBE event as well. Since we don't
check for this, we return NOTIFY_DONE which causes a keypress for the
ACPI event to be propogated to userspace. This is the equivalent of
someone pressing the display key on a laptop every time there's a
hotplug event.

So, check for ACPI_VIDEO_NOTIFY_PROBE events and suppress keypresses
from them.
Signed-off-by: NLyude Paul <lyude@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit d9997b64c52b70bd98c48f443f068253621d1ffc upstream.

This caused a confusing error message, but there is functionally
no problem since the default method is DIRECT.
Reviewed-by: NMichel Dänzer <michel.daenzer@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 3df27645395e8f79c0dc20a15cf1da61f376000d upstream.

fix a typo in for loop: i->j
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NRex Zhu <Rex.Zhu@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 7f3ef5dedb146e3d5063b6845781ad1bb59b92b5 upstream.

Leaving the DRM driver enabled on reboot or kexec has the annoying
effect of leaving the display generating transactions whilst the
IOMMU has been shut down.

In turn, the IOMMU driver (which shares its interrupt line with
the VOP) starts warning either on shutdown or when entering the
secondary kernel in the kexec case (nothing is expected on that
front).

A cheap way of ensuring that things are nicely shut down is to
register a shutdown callback in the platform driver.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Tested-by: NVicente Bergas <vicencb@gmail.com>
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20180805124807.18169-1-marc.zyngier@arm.com
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 6f4d29df66acd49303a99025046b85cabe7aa17a upstream.

Without this change the following happens when using Python3 (3.6.6):

	$ echo "GPL-2.0" | python3 scripts/spdxcheck.py -
	FAIL: 'str' object has no attribute 'decode'
	Traceback (most recent call last):
	  File "scripts/spdxcheck.py", line 253, in <module>
	    parser.parse_lines(sys.stdin, args.maxlines, '-')
	  File "scripts/spdxcheck.py", line 171, in parse_lines
	    line = line.decode(locale.getpreferredencoding(False), errors='ignore')
	AttributeError: 'str' object has no attribute 'decode'

So as the line is already a string, there is no need to decode it and
the line can be dropped.

/usr/bin/python on Arch is Python 3.  So this would indeed be worth
going into 4.19.

Link: http://lkml.kernel.org/r/20181023070802.22558-1-u.kleine-koenig@pengutronix.deSigned-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Joe Perches <joe@perches.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a76cf1a474d7dbcd9336b5f5afb0162baa142cf0 upstream.

Spock reported that commit 172b06c3 ("mm: slowly shrink slabs with a
relatively small number of objects") leads to a regression on his setup:
periodically the majority of the pagecache is evicted without an obvious
reason, while before the change the amount of free memory was balancing
around the watermark.

The reason behind is that the mentioned above change created some
minimal background pressure on the inode cache.  The problem is that if
an inode is considered to be reclaimed, all belonging pagecache page are
stripped, no matter how many of them are there.  So, if a huge
multi-gigabyte file is cached in the memory, and the goal is to reclaim
only few slab objects (unused inodes), we still can eventually evict all
gigabytes of the pagecache at once.

The workload described by Spock has few large non-mapped files in the
pagecache, so it's especially noticeable.

To solve the problem let's postpone the reclaim of inodes, which have
more than 1 attached page.  Let's wait until the pagecache pages will be
evicted naturally by scanning the corresponding LRU lists, and only then
reclaim the inode structure.

Link: http://lkml.kernel.org/r/20181023164302.20436-1-guro@fb.comSigned-off-by: NRoman Gushchin <guro@fb.com>
Reported-by: NSpock <dairinin@gmail.com>
Tested-by: NSpock <dairinin@gmail.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: <stable@vger.kernel.org>	[4.19.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 72a58a63a164b4e9d2d914e65caeb551846883f1 upstream.

Commit:

  24d7c494 ("efi/arm-stub: Round up FDT allocation to mapping size")

increased the allocation size for the FDT image created by the stub to a
fixed value of 2 MB, to simplify the former code that made several
attempts with increasing values for the size. This is reasonable
given that the allocation is of type EFI_LOADER_DATA, which is released
to the kernel unless it is explicitly memblock_reserve()d by the early
boot code.

However, this allocation size leaked into the 'size' field of the FDT
header metadata, and so the entire allocation remains occupied by the
device tree binary, even if most of it is not used to store device tree
information.

So call fdt_pack() to shrink the FDT data structure to its minimum size
after populating all the fields, so that the remaining memory is no
longer wasted.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: <stable@vger.kernel.org> # v4.12+
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Fixes: 24d7c494 ("efi/arm-stub: Round up FDT allocation to mapping size")
Link: http://lkml.kernel.org/r/20181114175544.12860-4-ard.biesheuvel@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 873d7bcfd066663e3e50113dc4a0de19289b6354 upstream.

Commit a2468cc9 ("swap: choose swap device according to numa node")
changed 'avail_lists' field of 'struct swap_info_struct' to an array.
In popular linux distros it increased size of swap_info_struct up to 40
Kbytes and now swap_info_struct allocation requires order-4 page.
Switch to kvzmalloc allows to avoid unexpected allocation failures.

Link: http://lkml.kernel.org/r/fc23172d-3c75-21e2-d551-8b1808cbe593@virtuozzo.com
Fixes: a2468cc9 ("swap: choose swap device according to numa node")
Signed-off-by: NVasily Averin <vvs@virtuozzo.com>
Acked-by: NAaron Lu <aaron.lu@intel.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 5e41540c8a0f0e98c337dda8b391e5dda0cde7cf upstream.

This bug has been experienced several times by the Oracle DB team.  The
BUG is in remove_inode_hugepages() as follows:

	/*
	 * If page is mapped, it was faulted in after being
	 * unmapped in caller.  Unmap (again) now after taking
	 * the fault mutex.  The mutex will prevent faults
	 * until we finish removing the page.
	 *
	 * This race can only happen in the hole punch case.
	 * Getting here in a truncate operation is a bug.
	 */
	if (unlikely(page_mapped(page))) {
		BUG_ON(truncate_op);

In this case, the elevated map count is not the result of a race.
Rather it was incorrectly incremented as the result of a bug in the huge
pmd sharing code.  Consider the following:

 - Process A maps a hugetlbfs file of sufficient size and alignment
   (PUD_SIZE) that a pmd page could be shared.

 - Process B maps the same hugetlbfs file with the same size and
   alignment such that a pmd page is shared.

 - Process B then calls mprotect() to change protections for the mapping
   with the shared pmd. As a result, the pmd is 'unshared'.

 - Process B then calls mprotect() again to chage protections for the
   mapping back to their original value. pmd remains unshared.

 - Process B then forks and process C is created. During the fork
   process, we do dup_mm -> dup_mmap -> copy_page_range to copy page
   tables. Copying page tables for hugetlb mappings is done in the
   routine copy_hugetlb_page_range.

In copy_hugetlb_page_range(), the destination pte is obtained by:

	dst_pte = huge_pte_alloc(dst, addr, sz);

If pmd sharing is possible, the returned pointer will be to a pte in an
existing page table.  In the situation above, process C could share with
either process A or process B.  Since process A is first in the list,
the returned pte is a pointer to a pte in process A's page table.

However, the check for pmd sharing in copy_hugetlb_page_range is:

	/* If the pagetables are shared don't copy or take references */
	if (dst_pte == src_pte)
		continue;

Since process C is sharing with process A instead of process B, the
above test fails.  The code in copy_hugetlb_page_range which follows
assumes dst_pte points to a huge_pte_none pte.  It copies the pte entry
from src_pte to dst_pte and increments this map count of the associated
page.  This is how we end up with an elevated map count.

To solve, check the dst_pte entry for huge_pte_none.  If !none, this
implies PMD sharing so do not copy.

Link: http://lkml.kernel.org/r/20181105212315.14125-1-mike.kravetz@oracle.com
Fixes: c5c99429 ("fix hugepages leak due to pagetable page sharing")
Signed-off-by: NMike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Prakash Sangappa <prakash.sangappa@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 1c23b4108d716cc848b38532063a8aca4f86add8 upstream.

gcc-8 complains about the prototype for this function:

  lib/ubsan.c:432:1: error: ignoring attribute 'noreturn' in declaration of a built-in function '__ubsan_handle_builtin_unreachable' because it conflicts with attribute 'const' [-Werror=attributes]

This is actually a GCC's bug. In GCC internals
__ubsan_handle_builtin_unreachable() declared with both 'noreturn' and
'const' attributes instead of only 'noreturn':

   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84210

Workaround this by removing the noreturn attribute.

[aryabinin: add information about GCC bug in changelog]
Link: http://lkml.kernel.org/r/20181107144516.4587-1-aryabinin@virtuozzo.comSigned-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: NOlof Johansson <olof@lixom.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>