From: Fredrik Markström <fredrik.markstrom@gmail.com>
Date: Fri, 16 May 2014 02:10:38 +0000 (+0800)
Subject: Fix: Align buffers from objstack_alloc on sizeof(void *)
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=cae67efbd9ddf2cee6bbefec076dc8933ababc43;p=deliverable%2Fbabeltrace.git

Fix: Align buffers from objstack_alloc on sizeof(void *)

The buffers from objstack_alloc will store pointers, so they must
be aligned on a pointer's size, or else it will cause issues on the
CPUs which do not support unaligned addresses access.

Signed-off-by: Fredrik Markstrom <fredrik.markstrom@gmail.com>
Signed-off-by: Roy Li <rongqing.li@windriver.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/formats/ctf/metadata/objstack.c b/formats/ctf/metadata/objstack.c
index 9e264a415..14d925215 100644
--- a/formats/ctf/metadata/objstack.c
+++ b/formats/ctf/metadata/objstack.c
@@ -27,6 +27,7 @@
 #include <stdlib.h>
 #include <babeltrace/list.h>
 #include <babeltrace/babeltrace-internal.h>
+#include <babeltrace/align.h>
 
 #define OBJSTACK_INIT_LEN		128
 #define OBJSTACK_POISON			0xcc
@@ -39,7 +40,7 @@ struct objstack_node {
 	struct bt_list_head node;
 	size_t len;
 	size_t used_len;
-	char data[];
+	char __attribute__ ((aligned (sizeof(void *)))) data[];
 };
 
 BT_HIDDEN
@@ -118,6 +119,8 @@ void *objstack_alloc(struct objstack *objstack, size_t len)
 	struct objstack_node *last_node;
 	void *p;
 
+	len = ALIGN(len, sizeof(void *));
+
 	/* Get last node */
 	last_node = bt_list_entry(objstack->head.prev,
 			struct objstack_node, node);