From: Jens Axboe Date: Fri, 27 Feb 2009 19:14:20 +0000 (+0100) Subject: cciss: add BUILD_BUG_ON() for catching bad CommandList_struct alignment X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=10cbda97e73c7d537d7174eadb2d098484f8f1da;p=linux-beck.git 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 --- 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 */