exception interception

exception interception

[X]

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Hello,

Could someone kindly point me to the code in Xen for handling the
exceptions intercepted from PV guest kernels?

Thanks.

===More detail===
I was looking at some futex code in a guest kernel. The kernel code below
must have caused an exception and thus trapped into Xen. But I have not
figured out where exactly Xen processes the intercepted exception.

from guest kernel's arch/x86/include/asm/futex.h, in function
futex_atomic_cmpxchg_inatomic
asm volatile("1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n"
     "2:\t.section .fixup, \"ax\"\n"
     "3:\tmov     %3, %0\n"
     "\tjmp     2b\n"
     "\t.previous\n"
     _ASM_EXTABLE(1b, 3b)
     : "+r" (ret), "=a" (oldval), "+m" (*uaddr)
     : "i" (-EFAULT), "r" (newval), "1" (oldval)
     : "memory"
);
==========

X

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Re: exception interception

[Tim Deegan]

At 15:45 -0500 on 12 Feb (1329061516), X wrote:
> Hello,
> 
> Could someone kindly point me to the code in Xen for handling the
> exceptions intercepted from PV guest kernels?

Have a look at xen/arch/x86/traps.c

Cheers,

Tim.