[Buildroot] [PATCH 1/2] libaio: work-around for PowerPC issue

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Hello,

On Thu, 11 Aug 2016 00:00:52 +0200, Thomas Petazzoni wrote:
> Both the blktrace and gadgetfs-test packages were failing to build on
> PowerPC due to the mysterious:
> 
>   hidden symbol `_rest32gpr_30_x' in libgcc.a(e500crtresx32gpr.o) is referenced by DSO
> 
> Due to this error, we disabled blktrace on PowerPC in commit
> 0d8158fc619ce849b531d07b27da4ba9748d4ea4. However, gadgetfs-test
> continued to fail with the same error. As Romain Naour pointed out, the
> problem seems in fact to come from a common dependency of blktrace and
> gadgetfs-test: libaio. As Romain investigated, the problem started
> appearing after the last bump of libaio, from version 0.3.109 to
> 0.3.110.
> 
> A quick bisect through the libaio changes between 0.3.109 and 0.3.110
> has revealed that the problematic change is one in the libaio build
> system, which now obeys to the CFLAGS provided in the environment,
> rather than overriding them. So the CFLAGS provided by Buildroot cause
> this problem. It turns out that the problematic CFLAGS is -Os, which is
> indeed known to cause issues on PowerPC in some corner cases.
> 
> Even though it would probably be a better long-term solution to switch
> to -O2 by default, and mark -Os as not available on PowerPC, it is a too
> radical change so close to 2016.08. So we simply adjust the libaio
> package so that it uses -O2 instead of -Os.
> 
> Fixes:
> 
>   http://autobuild.buildroot.net/results/5e6cc4c432ce6c964ac285026978ad14d9eae97c/
> 
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> ---
>  package/libaio/libaio.mk | 14 +++++++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)

Both patches applied.

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com