Re: need for packed attribute

From: Russell King
Date: Fri Jan 06 2006 - 13:37:39 EST


On Fri, Jan 06, 2006 at 07:15:43PM +0100, Oliver Neukum wrote:
> Hi,
>
> is there any architecture for which packed is required in structures like this:
>
> /* All standard descriptors have these 2 fields at the beginning */
> struct usb_descriptor_header {
> __u8 bLength;
> __u8 bDescriptorType;
> };

sizeof(struct usb_descriptor_header) will be 4 on ARM. If this
concerns you, you need to pack the structure thusly:

struct usb_descriptor_header {
__u8 bLength;
__u8 bDescriptorType;
} __attribute__((packed));


--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/