Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  dma-debug: Fix check_unmap null pointer dereference

1 files changed, 16 insertions, 12 deletions

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 65b0d99b6d0..58a9f9fc609 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -156,9 +156,13 @@ static bool driver_filter(struct device *dev)
                 return true;
 
         /* driver filter on and initialized */
-        if (current_driver && dev->driver == current_driver)
+        if (current_driver && dev && dev->driver == current_driver)
                 return true;
 
+        /* driver filter on, but we can't filter on a NULL device... */
+        if (!dev)
+                return false;
+
         if (current_driver || !current_driver_name[0])
                 return false;
 
@@ -183,17 +187,17 @@ static bool driver_filter(struct device *dev)
         return ret;
 }
 
-#define err_printk(dev, entry, format, arg...) do {             \
-                error_count += 1;                               \
-                if (driver_filter(dev) &&                       \
-                    (show_all_errors || show_num_errors > 0)) { \
-                        WARN(1, "%s %s: " format,               \
-                             dev_driver_string(dev),            \
-                             dev_name(dev) , ## arg);           \
-                        dump_entry_trace(entry);                \
-                }                                               \
-                if (!show_all_errors && show_num_errors > 0)    \
-                        show_num_errors -= 1;                   \
+#define err_printk(dev, entry, format, arg...) do {                     \
+                error_count += 1;                                       \
+                if (driver_filter(dev) &&                               \
+                    (show_all_errors || show_num_errors > 0)) {         \
+                        WARN(1, "%s %s: " format,                       \
+                             dev ? dev_driver_string(dev) : "NULL",     \
+                             dev ? dev_name(dev) : "NULL", ## arg);     \
+                        dump_entry_trace(entry);                        \
+                }                                                       \
+                if (!show_all_errors && show_num_errors > 0)            \
+                        show_num_errors -= 1;                           \
         } while (0);
 
 /*