svn commit: r213143 - user/weongyo/usb/sys/dev/usb

[Weongyo Jeong]

Author: weongyo
Date: Fri Sep 24 21:55:44 2010
New Revision: 213143
URL: http://svn.freebsd.org/changeset/base/213143

Log:
  Commits a experimental patch that I couldn't find cases when pc->buffer
  is NULL.  If this assertion is failed it means `struct usb_page_cache'
  is accessed after free or after encounting errors.

Modified:
  user/weongyo/usb/sys/dev/usb/usb_busdma.c

Modified: user/weongyo/usb/sys/dev/usb/usb_busdma.c
==============================================================================
--- user/weongyo/usb/sys/dev/usb/usb_busdma.c	Fri Sep 24 21:41:56 2010	(r213142)
+++ user/weongyo/usb/sys/dev/usb/usb_busdma.c	Fri Sep 24 21:55:44 2010	(r213143)
@@ -85,11 +85,8 @@ usbd_get_page(struct usb_page_cache *pc,
 
 #if USB_HAVE_BUSDMA
 	if (pc->page_start) {
-		/* Case 1 - something has been loaded into DMA */
-		if (pc->buffer) {
-			/* Case 1a - Kernel Virtual Address */
-			res->buffer = USB_ADD_BYTES(pc->buffer, offset);
-		}
+		USB_ASSERT(pc->buffer != NULL, ("pc->buffer is NULL"));
+		res->buffer = USB_ADD_BYTES(pc->buffer, offset);
 		offset += pc->page_offset_buf;
 		/* compute destination page */
 		page = pc->page_start;