Merge branch 'omap/multiplatform-fixes', tag 'v3.8-rc5' into next/multiplatform

[firefly-linux-kernel-4.4.55.git] / drivers / gpu / drm / i915 / i915_gem_execbuffer.c

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index d6a994a07393677fb5b4fd6edb868cf7bd460cbe..26d08bb5821894daad6cdd1fa79b58f86cf226e2 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -539,6 +539,8 @@ i915_gem_execbuffer_relocate_slow(struct drm_device *dev,
        total = 0;
        for (i = 0; i < count; i++) {
                struct drm_i915_gem_relocation_entry __user *user_relocs;
+               u64 invalid_offset = (u64)-1;
+               int j;
 
                user_relocs = (void __user *)(uintptr_t)exec[i].relocs_ptr;
 
@@ -549,6 +551,25 @@ i915_gem_execbuffer_relocate_slow(struct drm_device *dev,
                        goto err;
                }
 
+               /* As we do not update the known relocation offsets after
+                * relocating (due to the complexities in lock handling),
+                * we need to mark them as invalid now so that we force the
+                * relocation processing next time. Just in case the target
+                * object is evicted and then rebound into its old
+                * presumed_offset before the next execbuffer - if that
+                * happened we would make the mistake of assuming that the
+                * relocations were valid.
+                */
+               for (j = 0; j < exec[i].relocation_count; j++) {
+                       if (copy_to_user(&user_relocs[j].presumed_offset,
+                                        &invalid_offset,
+                                        sizeof(invalid_offset))) {
+                               ret = -EFAULT;
+                               mutex_lock(&dev->struct_mutex);
+                               goto err;
+                       }
+               }
+
                reloc_offset[i] = total;
                total += exec[i].relocation_count;
        }