From 10cbda97e73c7d537d7174eadb2d098484f8f1da Mon Sep 17 00:00:00 2001
From: Jens Axboe <jens.axboe@oracle.com>
Date: Fri, 27 Feb 2009 20:14:20 +0100
Subject: [PATCH] cciss: add BUILD_BUG_ON() for catching bad CommandList_struct
alignment
The hardware requires 64-bit alignment of commands, so add a build bug
check for that. The recent commit 8a3173de4ab4cdacc43675dc5c077f9a5bf17f5f
didn't change the size of the command, but other additions/changes may and
thus break badly at runtime.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---
drivers/block/cciss.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 4f9b6d792017..5d0e135824f9 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -3898,6 +3898,13 @@ static struct pci_driver cciss_pci_driver = {
*/
static int __init cciss_init(void)
{
+ /*
+ * The hardware requires that commands are aligned on a 64-bit
+ * boundary. Given that we use pci_alloc_consistent() to allocate an
+ * array of them, the size must be a multiple of 8 bytes.
+ */
+ BUILD_BUG_ON(sizeof(CommandList_struct) % 8);
+
printk(KERN_INFO DRIVER_NAME "\n");
/* Register for our PCI devices */
--
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