lkml.org 
[lkml]   [2014]   [Nov]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2] Btrfs: qgroup: add BUILD_BUG to report pointer cast breakage
On Thu, Nov 13, 2014 at 12:54:39AM +0900, Daniel Dressler wrote:
> Our ulist data structure stores at max 64bit
> values. qgroup has used this structure to store
> pointers. In the future when we upgrade to 128bit
> this casting of pointers to uint64_t will break.

What are we going to upgrade to 128 bits?

> This patch adds a BUILD_BUG ensuring that this
> code will not be left untouched in the upgrade.
>
> It also marks this issue on the TODO list so it
> may be addressed before such an upgrade.
>
> + (BUILD_BUG_ON_ZERO(sizeof(uintptr_t) > sizeof(u64)) + \

So it's pointers, this is similar to the 32bit -> 64bit transition, a
change that will affect everything, one BUILD_BUG on does not make any
difference.


\
 
 \ /
  Last update: 2014-11-21 17:21    [W:0.031 / U:1.576 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site