drivers/gpu/drm/i915/i915_irq.c:i915_error_object_create(): use correct kmap-atomic slot

i915_error_object_create() is called from the timer interrupt and hence
can corrupt the KM_USER0 slot.  Use KM_IRQ0 instead.

Reported-by: Jaswinder Singh Rajput <jaswinderlinux@gmail.com>
Tested-by: Jaswinder Singh Rajput <jaswinderlinux@gmail.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 2b8b969d0c15..df6a9cd82c4d 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -456,11 +456,15 @@ i915_error_object_create(struct drm_device *dev,
 
         for (page = 0; page < page_count; page++) {
                 void *s, *d = kmalloc(PAGE_SIZE, GFP_ATOMIC);
+                unsigned long flags;
+
                 if (d == NULL)
                         goto unwind;
-                s = kmap_atomic(src_priv->pages[page], KM_USER0);
+                local_irq_save(flags);
+                s = kmap_atomic(src_priv->pages[page], KM_IRQ0);
                 memcpy(d, s, PAGE_SIZE);
-                kunmap_atomic(s, KM_USER0);
+                kunmap_atomic(s, KM_IRQ0);
+                local_irq_restore(flags);
                 dst->pages[page] = d;
         }
         dst->page_count = page_count;