From: Keir Fraser <keir.fraser@citrix.com>
Date: Wed, 2 Apr 2008 14:32:13 +0000 (+0100)
Subject: minios: Fix xfree() bug.
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=6e756bd86c4d0dd8ccc2c93b748ea35de121dea5;p=people%2Fliuw%2Flibxenctrl-split%2Fmini-os.git

minios: Fix xfree() bug.

It has to check first if the memory to free is so big as to be freed
directly by free_pages. mini-os domains crash without this patch if
vfb is misconfigured.

Signed-off-by: INAKOSHI Hiroya <inakoshi.hiroya@jp.fujitsu.com>
---

diff --git a/lib/xmalloc.c b/lib/xmalloc.c
index d4c3941..82d5cc6 100644
--- a/lib/xmalloc.c
+++ b/lib/xmalloc.c
@@ -208,6 +208,13 @@ void xfree(const void *p)
     pad = (struct xmalloc_pad *)p - 1;
     hdr = (struct xmalloc_hdr *)((char *)p - pad->hdr_size);
 
+    /* Big allocs free directly. */
+    if ( hdr->size >= PAGE_SIZE )
+    {
+        free_pages(hdr, get_order(hdr->size));
+        return;
+    }
+
     /* We know hdr will be on same page. */
     if(((long)p & PAGE_MASK) != ((long)hdr & PAGE_MASK))
     {
@@ -222,13 +229,6 @@ void xfree(const void *p)
         *(int*)0=0;
     }
 
-    /* Big allocs free directly. */
-    if ( hdr->size >= PAGE_SIZE )
-    {
-        free_pages(hdr, get_order(hdr->size));
-        return;
-    }
-
     /* Merge with other free block, or put in list. */
     /* spin_lock_irqsave(&freelist_lock, flags); */
     list_for_each_entry_safe( i, tmp, &freelist, freelist )