drm/i915: Limit number of capture objects

If we fail to allocate an array for a large number of user requested
capture objects, reduce the array size and try to grab at least some of
the objects!

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180911115810.8917-3-chris@chris-wilson.co.uk

1 files changed, 13 insertions, 7 deletions

diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 8c81cf3aa182..1175fec08fe1 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -1391,15 +1391,20 @@ static void request_record_user_bo(struct i915_request *request,
 {
         struct i915_capture_list *c;
         struct drm_i915_error_object **bo;
-        long count;
+        long count, max;
 
-        count = 0;
+        max = 0;
         for (c = request->capture_list; c; c = c->next)
-                count++;
+                max++;
+        if (!max)
+                return;
 
-        bo = NULL;
-        if (count)
-                bo = kcalloc(count, sizeof(*bo), GFP_ATOMIC);
+        bo = kmalloc_array(max, sizeof(*bo), GFP_ATOMIC);
+        if (!bo) {
+                /* If we can't capture everything, try to capture something. */
+                max = min_t(long, max, PAGE_SIZE / sizeof(*bo));
+                bo = kmalloc_array(max, sizeof(*bo), GFP_ATOMIC);
+        }
         if (!bo)
                 return;
 
@@ -1408,7 +1413,8 @@ static void request_record_user_bo(struct i915_request *request,
                 bo[count] = i915_error_object_create(request->i915, c->vma);
                 if (!bo[count])
                         break;
-                count++;
+                if (++count == max)
+                        break;
         }
 
         ee->user_bo = bo;