Re: aligned_{u64,be64,le64} defined in #ifdef __KERNEL__

Jan Engelhardt
2010-08-30T13:02:58Z

On Monday 2010-08-30 12:58, Andreas Gruenbacher wrote:
>
>> If we want a version of this type visible to userspace, it needs to,
>> for example, have double underscores prepended to the type name just
>> as we do for things like __u16 and __u32.
>
>How about something like this?

I like that approach:

>From 3bec018a4835d4fdbe35595366a51bd09e3cc1d0 Mon Sep 17 00:00:00 2001
>From: Andreas Gruenbacher <agruen@suse.de>
>Date: Mon, 30 Aug 2010 12:51:01 +0200
>Subject: [PATCH] Define __aligned_{u64,le64,be64} types with 8-byte alignment
>
>Convert the existing #defines into typedefs, prepend two underscores to
>avoid POSIX namespace pollution, and expose the types to user space.
>
>These types are useful for enforcing the same alignment on 32-bit and
>64-bit architectures. (Some 32-bit architectures only align 64-bit
>values on 4-byte boundaries by default.)
>
>(The aligned types are used by some netfilter user-space headers
>already.)
>
>Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
>---
> include/linux/if_ppp.h | 16 +++++++-------
> include/linux/netfilter/nfnetlink_log.h | 4 +-
> include/linux/netfilter/nfnetlink_queue.h | 4 +-
> include/linux/netfilter/xt_connbytes.h | 4 +-
> include/linux/netfilter/xt_quota.h | 2 +-
> include/linux/types.h | 10 ++++----
> include/scsi/scsi_tgt_if.h | 30 ++++++++++++++--------------
> include/xen/interface/hvm/hvm_op.h | 2 +-
> 8 files changed, 36 insertions(+), 36 deletions(-)
>
>diff --git a/include/linux/if_ppp.h b/include/linux/if_ppp.h
>index fcef103..c9ad383 100644
>--- a/include/linux/if_ppp.h
>+++ b/include/linux/if_ppp.h
>@@ -114,14 +114,14 @@ struct pppol2tp_ioc_stats {
> __u16 tunnel_id; /* redundant */
> __u16 session_id; /* if zero, get tunnel stats */
> __u32 using_ipsec:1; /* valid only for session_id == 0 */
>- aligned_u64 tx_packets;
>- aligned_u64 tx_bytes;
>- aligned_u64 tx_errors;
>- aligned_u64 rx_packets;
>- aligned_u64 rx_bytes;
>- aligned_u64 rx_seq_discards;
>- aligned_u64 rx_oos_packets;
>- aligned_u64 rx_errors;
>+ __aligned_u64 tx_packets;
>+ __aligned_u64 tx_bytes;
>+ __aligned_u64 tx_errors;
>+ __aligned_u64 rx_packets;
>+ __aligned_u64 rx_bytes;
>+ __aligned_u64 rx_seq_discards;
>+ __aligned_u64 rx_oos_packets;
>+ __aligned_u64 rx_errors;