Messages in this thread | | | Date | Mon, 05 Oct 2009 17:36:02 -0700 | From | Jeremy Fitzhardinge <> | Subject | Re: [Xen-devel] Re: [PATCH] xen: Disable stack protector for irq helper |
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On 10/05/09 15:43, Bastian Blank wrote: > On Mon, Oct 05, 2009 at 10:21:01AM -0700, Jeremy Fitzhardinge wrote: > >>> Save all caller-saved registers on x86_32 for the paravirt callee saved >>> registers. >>> >> That looks better, but it is still overkill. We only need to save the >> set of registers the ABI requires the callee to preserve. What >> additional register(s) gets clobbered by stack-protector that need to be >> saved? >> > Well, exactly the two, ecx and edx. eax is still clobbered by the return > value. Anyway, it works in praxis.
I'm confused. It already saves ecx, so what else needs saving?
Besides, most of the code in that file isn't used unless you're using a very old version of Xen; it will generally prefer to use the ones in xen-asm_X.S.
I have the feeling we haven't really found the root cause of your problem yet.
Thanks, J
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