Date: Fri, 22 Jan 2010 17:38:38 -0800 (PST)
Message-Id: <20100122.173838.159363288.davem@davemloft.net>
To: heiko.carstens@de.ibm.com
Cc: rostedt@goodmis.org, vapier@gentoo.org, linux-kernel@vger.kernel.org,
       fweisbec@gmail.com, mingo@redhat.com, brueckner@linux.vnet.ibm.com,
       lethal@linux-sh.org
Subject: Re: [PATCH] ftrace: unify arch_syscall_addr() implementations
From: David Miller <davem@davemloft.net>
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From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Fri, 22 Jan 2010 17:37:00 +0100

> On Fri, Jan 22, 2010 at 09:36:17AM -0500, Steven Rostedt wrote:
>> I would not be too sure. s390 is very strange, and I would definitely
>> want to get an Ack from the arch maintainers first.
> 
> It's not a typo. The syscall table on s390 contains always 32 bit pointers
> since we know that the address of the function to be called is (way) below
> 4GB. So this saves us a few bytes.
> In addition this makes syscall patching done by some security modules a
> bit more difficult, since they would need to store a 64 bit pointer.
> That's because we make sure that module addresses are always above 4GB.

Sparc64 is the same way.
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