From: Kevin Wolf <kwolf@redhat.com>
Date: Wed, 10 Jun 2015 11:47:35 +0000 (+0200)
Subject: queue.h: Add QLIST_FIX_HEAD_PTR()
X-Git-Tag: v2.4.0-rc0~75^2~3
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ae81693004fd95f7013e42811944707a92948d9a;p=thirdparty%2Fqemu.git

queue.h: Add QLIST_FIX_HEAD_PTR()

If the head of a list has been moved to a different memory location, the
le_prev link in the first list entry has to be fixed up. Provide a macro
that implements this fixup.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---

diff --git a/include/qemu/queue.h b/include/qemu/queue.h
index f781aa20a83..a8d3cb8e630 100644
--- a/include/qemu/queue.h
+++ b/include/qemu/queue.h
@@ -117,6 +117,12 @@ struct {                                                                \
         }                                                               \
 } while (/*CONSTCOND*/0)
 
+#define QLIST_FIX_HEAD_PTR(head, field) do {                            \
+        if ((head)->lh_first != NULL) {                                 \
+            (head)->lh_first->field.le_prev = &(head)->lh_first;        \
+        }                                                               \
+} while (/*CONSTCOND*/0)
+
 #define QLIST_INSERT_AFTER(listelm, elm, field) do {                    \
         if (((elm)->field.le_next = (listelm)->field.le_next) != NULL)  \
                 (listelm)->field.le_next->field.le_prev =               \