diff --git a/[refs] b/[refs]
index d2fb1263a9db..0dc1164bad43 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 3578baaed4613a9fc09bab9f79f6ce2ac682e8a3
+refs/heads/master: ff52c3b02b3f73178bfe0c219cd22abdcb0e46c3
diff --git a/trunk/arch/x86/include/asm/uaccess.h b/trunk/arch/x86/include/asm/uaccess.h
index d710a2555fd6..5ee26875baea 100644
--- a/trunk/arch/x86/include/asm/uaccess.h
+++ b/trunk/arch/x86/include/asm/uaccess.h
@@ -148,9 +148,16 @@ __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
  *
  * Returns zero on success, or -EFAULT on error.
  * On error, the variable @x is set to zero.
- *
+ */
+/*
  * Careful: we have to cast the result to the type of the pointer
  * for sign reasons.
+ *
+ * The use of %edx as the register specifier is a bit of a
+ * simplification, as gcc only cares about it as the starting point
+ * and not size: for a 64-bit value it will use %ecx:%edx on 32 bits
+ * (%ecx being the next register in gcc's x86 register sequence), and
+ * %rdx on 64 bits.
  */
 #define get_user(x, ptr)						\
 ({									\