[Bug 108850] i915 "kernel NULL pointer dereference" in kernel-4.18.20

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=108850

Chris Wilson <chris at chris-wilson.co.uk> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--- Comment #6 from Chris Wilson <chris at chris-wilson.co.uk> ---
commit 5179749925933575a67f9d8f16d0cc204f98a29f (HEAD -> drm-intel-next-queued, 
drm-intel/for-linux-next, drm-intel/drm-intel-next-queued)
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Tue Dec 4 14:15:16 2018 +0000

    drm/i915: Allocate a common scratch page

    Currently we allocate a scratch page for each engine, but since we only
    ever write into it for post-sync operations, it is not exposed to
    userspace nor do we care for coherency. As we then do not care about its
    contents, we can use one page for all, reducing our allocations and
    avoid complications by not assuming per-engine isolation.

    For later use, it simplifies engine initialisation (by removing the
    allocation that required struct_mutex!) and means that we can always rely
    on there being a scratch page.

    v2: Check that we allocated a large enough scratch for I830 w/a

    Fixes: 06e562e7f515 ("drm/i915/ringbuffer: Delay after EMIT_INVALIDATE for
gen4/gen5") # v4.18.20
    Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108850
    Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
    Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
    Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
    Reviewed-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>
    Link:
https://patchwork.freedesktop.org/patch/msgid/20181204141522.13640-1-chris@chris-wilson.co.uk
    Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
    Cc: <stable at vger.kernel.org> # v4.18.20+

should apply to v4.18 (and be auto-backported) and prevent the NULL deref.

-- 
You are receiving this mail because:
You are on the CC list for the bug.
You are the assignee for the bug.
You are the QA Contact for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20181204/1127e4b6/attachment-0001.html>