qemu-dma-null-pointer-check

xen虚拟机源代码安装包

Index: ioemu/hw/dma.c
===================================================================
--- ioemu.orig/hw/dma.c	2007-05-03 18:17:33.000000000 +0100
+++ ioemu/hw/dma.c	2007-05-03 20:59:42.000000000 +0100
@@ -340,6 +340,8 @@
 #endif
 
     r = dma_controllers[ncont].regs + ichan;
+    if (r->transfer_handler == NULL)
+	return;
     n = r->transfer_handler (r->opaque, ichan + (ncont << 2),
                              r->now[COUNT], (r->base[COUNT] + 1) << ncont);
     r->now[COUNT] = n;