From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@redhat.com>
Subject: Re: [PATCH 1/2] test: Add IDT framework
Date: Thu, 10 Jun 2010 12:49:16 +0300
Message-ID: <4C10B51C.9070502@redhat.com>
References: <1276140703-30046-1-git-send-email-sheng@linux.intel.com>
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Cc: Marcelo Tosatti <mtosatti@redhat.com>, kvm@vger.kernel.org
To: Sheng Yang <sheng@linux.intel.com>
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On 06/10/2010 06:31 AM, Sheng Yang wrote:
> +
> +#define EXCEPTION_REGION_BEGIN(r, lb) \
> +    asm volatile("pushq $"lb"\n\t" \
> +                 "mov $2, %0\n\t" \
> +                 : "=r"(r))
> +#define EXCEPTION_REGION_END(r, lb) \
> +    asm volatile("popq %%rdx\n\t" \
> +		 "mov $0, %0\n\t" \
> +                 lb":\n\t": \
> +                 "=r"(r) :: "%rdx")
>    

These mess up the stack, no?  So if any intervening code uses %rsp based 
addressing, it will get incorrect information.

I suggest using a special data section like the kernel.

Also, most tests that use asm don't need an exception region, but will 
want to trap an exception on a single address.  So need a macro designed 
to be placed in asm in front of the faulting instruction.


-- 
error compiling committee.c: too many arguments to function