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Date: Fri, 22 May 2015 23:18:57 +0200 (CEST)
From: Jiri Kosina <jkosina@suse.cz>
To: Josh Poimboeuf <jpoimboe@redhat.com>
cc: Borislav Petkov <bp@alien8.de>, Ingo Molnar <mingo@kernel.org>,
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        Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH v4 0/3] Compile-time stack frame pointer validation
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On Fri, 22 May 2015, Josh Poimboeuf wrote:

> Hm, alternatives do complicate things a bit.  It *is* a false positive,
> but not necessarily because its part of an alternative instruction
> block.
> 
> The above code would be patched into memmove(), which is a leaf function
> because it doesn't call any other functions.  Leaf functions don't need
> frame pointer logic, so we can ignore them.
> 
> If instead the above code were patched into a non-leaf function, we'd
> have to change it to restore the frame pointer before returning.

Is this really only a problem of alternatives? How about 
dynamically-enabled tracepoints?

-- 
Jiri Kosina
SUSE Labs