[lttng-dev] [PATCH v2] Fix: Align buffers from objstack_alloc on sizeof(void *)

[rongqing.li at windriver.com]

From: Fredrik Markström <fredrik.markstrom at gmail.com>

The buffers from objstack_alloc will store the pointer, so it must
be aligned on pointer, or else it will cause issue on the cpu
which does not support unaligned addresses access

Signed-off-by: Fredrik Markstrom <fredrik.markstrom at gmail.com>
Signed-off-by: Roy Li <rongqing.li at windriver.com>
---
 formats/ctf/metadata/objstack.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/formats/ctf/metadata/objstack.c b/formats/ctf/metadata/objstack.c
index 9e264a4..0e7d04e 100644
--- a/formats/ctf/metadata/objstack.c
+++ b/formats/ctf/metadata/objstack.c
@@ -39,7 +39,7 @@ 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 +118,8 @@ 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);
-- 
1.7.10.4