Patch "drm/i915/ppgtt: Break loop in gen8_ppgtt_clear_range failure path" has been added to the 4.1-stable tree

Patch "drm/i915/ppgtt: Break loop in gen8_ppgtt_clear_range failure path" has been added to the 4.1-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    drm/i915/ppgtt: Break loop in gen8_ppgtt_clear_range failure path

to the 4.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-i915-ppgtt-break-loop-in-gen8_ppgtt_clear_range-failure-path.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 00245266b4be4fbe989ee073663f56716da6c1f3 Mon Sep 17 00:00:00 2001
From: Michel Thierry <michel.thierry@intel.com>
Date: Thu, 25 Jun 2015 12:59:38 +0100
Subject: drm/i915/ppgtt: Break loop in gen8_ppgtt_clear_range failure path

From: Michel Thierry <michel.thierry@intel.com>

commit 00245266b4be4fbe989ee073663f56716da6c1f3 upstream.

If for some reason [1], the page directory/table does not exist, clear_range
would end up in an infinite while loop.

Introduced by commit 06fda602dbca ("drm/i915: Create page table allocators").

[1] This is already being addressed in one of Mika's patches:
http://mid.gmane.org/1432314314-23530-17-git-send-email-mika.kuoppala@intel.com

Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reported-by: John Harrison <john.c.harrison@intel.com>
Signed-off-by: Michel Thierry <michel.thierry@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/i915/i915_gem_gtt.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -502,17 +502,17 @@ static void gen8_ppgtt_clear_range(struc
 		struct page *page_table;
 
 		if (WARN_ON(!ppgtt->pdp.page_directory[pdpe]))
-			continue;
+			break;
 
 		pd = ppgtt->pdp.page_directory[pdpe];
 
 		if (WARN_ON(!pd->page_table[pde]))
-			continue;
+			break;
 
 		pt = pd->page_table[pde];
 
 		if (WARN_ON(!pt->page))
-			continue;
+			break;
 
 		page_table = pt->page;
 


Patches currently in stable-queue which might be from michel.thierry@intel.com are

queue-4.1/drm-i915-ppgtt-break-loop-in-gen8_ppgtt_clear_range-failure-path.patch