Subject: [PATCH v2] arm: fix memset-related crashes caused by recent GCC (4.7.2) optimizations

From: [email-masked] (Alexander Holler)
Date: Sun, 10 Mar 2013 18:06:11 +0100

Am 07.03.2013 16:17, schrieb Russell King - ARM Linux:
> On Wed, Mar 06, 2013 at 08:15:17PM +0100, Dirk Behme wrote:
>> Am 11.02.2013 13:57, schrieb Ivan Djelic:
>>> Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on
>>> assumptions about the implementation of memset and similar functions.
>>> The current ARM optimized memset code does not return the value of
>>> its first argument, as is usually expected from standard implementations.

I've just tried this patch with kernel 4.8.2 on an armv5-system where I 
use gcc 4.7.2 since several months and where most parts of the system 
are compiled with gcc 4.7.2 too.

And I had at least one problem which manifested itself with

[  181.198559] pts1: unknown flag 212

while trying to establish a btle-connection.

So I assume either the patch is wrong, the patch isn't the whole story, 
an existing bug is now triggered, or ...

I don't know.

Regards,

Alexander