drm/i915: Prevent module unload to avoid random memory corruption

[net-next-2.6.git] / drivers / gpu / drm / i915 / i915_dma.c

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index a7ec93e62f811800003dcc655a7580473d748d33..2dd2c93ebfa35dace7916b38c6df18c835161978 100644 (file)
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -620,8 +620,10 @@ static int i915_batchbuffer(struct drm_device *dev, void *data,
                ret = copy_from_user(cliprects, batch->cliprects,
                                     batch->num_cliprects *
                                     sizeof(struct drm_clip_rect));
-               if (ret != 0)
+               if (ret != 0) {
+                       ret = -EFAULT;
                        goto fail_free;
+               }
        }
 
        mutex_lock(&dev->struct_mutex);
@@ -662,8 +664,10 @@ static int i915_cmdbuffer(struct drm_device *dev, void *data,
                return -ENOMEM;
 
        ret = copy_from_user(batch_data, cmdbuf->buf, cmdbuf->sz);
-       if (ret != 0)
+       if (ret != 0) {
+               ret = -EFAULT;
                goto fail_batch_free;
+       }
 
        if (cmdbuf->num_cliprects) {
                cliprects = kcalloc(cmdbuf->num_cliprects,
@@ -676,8 +680,10 @@ static int i915_cmdbuffer(struct drm_device *dev, void *data,
                ret = copy_from_user(cliprects, cmdbuf->cliprects,
                                     cmdbuf->num_cliprects *
                                     sizeof(struct drm_clip_rect));
-               if (ret != 0)
+               if (ret != 0) {
+                       ret = -EFAULT;
                        goto fail_clip_free;
+               }
        }
 
        mutex_lock(&dev->struct_mutex);
@@ -885,7 +891,7 @@ intel_alloc_mchbar_resource(struct drm_device *dev)
        int reg = IS_I965G(dev) ? MCHBAR_I965 : MCHBAR_I915;
        u32 temp_lo, temp_hi = 0;
        u64 mchbar_addr;
-       int ret = 0;
+       int ret;
 
        if (IS_I965G(dev))
                pci_read_config_dword(dev_priv->bridge_dev, reg + 4, &temp_hi);
@@ -895,22 +901,23 @@ intel_alloc_mchbar_resource(struct drm_device *dev)
        /* If ACPI doesn't have it, assume we need to allocate it ourselves */
 #ifdef CONFIG_PNP
        if (mchbar_addr &&
-           pnp_range_reserved(mchbar_addr, mchbar_addr + MCHBAR_SIZE)) {
-               ret = 0;
-               goto out;
-       }
+           pnp_range_reserved(mchbar_addr, mchbar_addr + MCHBAR_SIZE))
+               return 0;
 #endif
 
        /* Get some space for it */
-       ret = pci_bus_alloc_resource(dev_priv->bridge_dev->bus, &dev_priv->mch_res,
+       dev_priv->mch_res.name = "i915 MCHBAR";
+       dev_priv->mch_res.flags = IORESOURCE_MEM;
+       ret = pci_bus_alloc_resource(dev_priv->bridge_dev->bus,
+                                    &dev_priv->mch_res,
                                     MCHBAR_SIZE, MCHBAR_SIZE,
                                     PCIBIOS_MIN_MEM,
-                                    0,   pcibios_align_resource,
+                                    0, pcibios_align_resource,
                                     dev_priv->bridge_dev);
        if (ret) {
                DRM_DEBUG_DRIVER("failed bus alloc: %d\n", ret);
                dev_priv->mch_res.start = 0;
-               goto out;
+               return ret;
        }
 
        if (IS_I965G(dev))
@@ -919,8 +926,7 @@ intel_alloc_mchbar_resource(struct drm_device *dev)
 
        pci_write_config_dword(dev_priv->bridge_dev, reg,
                               lower_32_bits(dev_priv->mch_res.start));
-out:
-       return ret;
+       return 0;
 }
 
 /* Setup MCHBAR if possible, return true if we should disable it again */
@@ -1781,9 +1787,9 @@ unsigned long i915_chipset_val(struct drm_i915_private *dev_priv)
                }
        }
 
-       div_u64(diff, diff1);
+       diff = div_u64(diff, diff1);
        ret = ((m * diff) + c);
-       div_u64(ret, 10);
+       ret = div_u64(ret, 10);
 
        dev_priv->last_count1 = total_count;
        dev_priv->last_time1 = now;
@@ -1852,7 +1858,7 @@ void i915_update_gfx_val(struct drm_i915_private *dev_priv)
 
        /* More magic constants... */
        diff = diff * 1181;
-       div_u64(diff, diffms * 10);
+       diff = div_u64(diff, diffms * 10);
        dev_priv->gfx_power = diff;
 }
 
@@ -2082,6 +2088,10 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
                goto free_priv;
        }
 
+       /* overlay on gen2 is broken and can't address above 1G */
+       if (IS_GEN2(dev))
+               dma_set_coherent_mask(&dev->pdev->dev, DMA_BIT_MASK(30));
+
        dev_priv->regs = ioremap(base, size);
        if (!dev_priv->regs) {
                DRM_ERROR("failed to map registers\n");
@@ -2221,6 +2231,9 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
        dev_priv->mchdev_lock = &mchdev_lock;
        spin_unlock(&mchdev_lock);
 
+       /* XXX Prevent module unload due to memory corruption bugs. */
+       __module_get(THIS_MODULE);
+
        return 0;
 
 out_workqueue_free: