Re: [Xen-devel] [PATCH 06/10] tools/insn-fuzz: Correct hook prototypes, and assert() appropriate segments

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 27.03.17 at 11:56, <andrew.cooper3@xxxxxxxxxx> wrote:
> The correct prototypes for the hooks are to use enum x86_segment rather than
> unsigned int.  It is implementation specific as to whether this compiles.

I'm actually surprised this has worked so far. We should fix the test
harness in the same way.

> @@ -235,27 +246,37 @@ static int fuzz_rep_stos(
>      unsigned long *reps,
>      struct x86_emulate_ctxt *ctxt)
>  {
> +    /*
> +     * STOS itself may only have an %es segment, but the stos() hook is 
> reused
> +     * for CLZERO.
> +     */
> +    assert(is_x86_user_segment(seg));

Perhaps worth looking at ctxt->opcode?

>  static int fuzz_cmpxchg(
> -    unsigned int seg,
> +    enum x86_segment seg,
>      unsigned long offset,
>      void *old,
>      void *new,
>      unsigned int bytes,
>      struct x86_emulate_ctxt *ctxt)
>  {
> +    assert((unsigned int)seg < x86_seg_none);

I guess this could be slightly more strict, not allowing IDTR and TR.
Perhaps then also for the write handler.

Other than the above (which are only suggestions)
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>

Jan


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