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Re: [PATCH, i386]: Fix PR 41900, call *%esp shouldn't be generated beca

Subject: Re: [PATCH, i386]: Fix PR 41900, call *%esp shouldn't be generated because of CPU errata
From: Uros Bizjak
Date: Tue, 03 Nov 2009 19:47:07 +0100
On 11/03/2009 06:31 PM, Jakub Jelinek wrote:
No, this test failed due to missing "volatile" (fixed now). AFAICS, it
works OK on Fedora 11 and CentOS 5.3.

The extra volatile doesn't help at all, it still fails here (Fedora 11,
x86_64 kernel, SELinux enforcing).

Hm, indeed. Is there a solution by somehow enabling execution (like
trampolines)?
You can assemble with -Wa,--execstack or link with -Wl,-z,execstack.
But it helps only in some cases, some versions of the policy won't allow
unconfined processes to have exec stack, you'd need to chcon -t java_exec_t
or similar.  This is highly Linux specific though.

I think I'll just make the test compile-only and scan for call without *%esp argument, as you suggested in your previous mails.

Thanks,
Uros.


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