Re: [PATCH v1 1/1] Fix PR16193 - gdbserver aborts.

[Walfred Tedeschi <walfred.tedeschi@intel.com>]

Hello All,

For clarification the macro I386_XSTATE_SIZE(XCR0) was returning for any 
XCR0 the value 576.
However when reading the registers we used more than this buffer size 
(when on AVX case).
Interestingly this did not happened for MPX.

Patch bellow changes/fixes the I386_XSTATE_SIZE(XCR0). To fix acctually 
the problem we decided to improve
macro readability.

Regards,
-Fred



Am 11/25/2013 2:40 PM, schrieb Walfred Tedeschi:
> Macro returning the size of the xsave buffer got broken with the MPX
> patch.  Fix improves the macro to make it more readable.
>
> 2013-12-25  Walfred Tedeschi  <walfred.tedeschi@intel.com>
>
> 	* i386-xstate.h (I386_XSTATE_MPX): New Macro.
> 	(I386_XSTATE_MPX_MASK): Makes use of I386_XSTATE_MPX.
> 	(HAS_MPX): New macro.
> 	(HAS_AVX): New macro.
> 	(I386_XSTATE_SIZE): Refactored macro using HAS_MPX and
> 	HAS_AVX.
> ---
>   gdb/common/i386-xstate.h | 16 +++++++++-------
>   1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/gdb/common/i386-xstate.h b/gdb/common/i386-xstate.h
> index e76ecc1..f8b85e3 100644
> --- a/gdb/common/i386-xstate.h
> +++ b/gdb/common/i386-xstate.h
> @@ -26,14 +26,13 @@
>   #define I386_XSTATE_AVX		(1ULL << 2)
>   #define I386_XSTATE_BNDREGS	(1ULL << 3)
>   #define I386_XSTATE_BNDCFG	(1ULL << 4)
> +#define I386_XSTATE_MPX		(I386_XSTATE_BNDREGS | I386_XSTATE_BNDCFG)
>   
>   /* Supported mask and size of the extended state.  */
>   #define I386_XSTATE_X87_MASK	I386_XSTATE_X87
>   #define I386_XSTATE_SSE_MASK	(I386_XSTATE_X87 | I386_XSTATE_SSE)
>   #define I386_XSTATE_AVX_MASK	(I386_XSTATE_SSE_MASK | I386_XSTATE_AVX)
> -#define I386_XSTATE_MPX_MASK	(I386_XSTATE_AVX_MASK \
> -				 | I386_XSTATE_BNDREGS \
> -				 | I386_XSTATE_BNDCFG)
> +#define I386_XSTATE_MPX_MASK	(I386_XSTATE_AVX_MASK | I386_XSTATE_MPX)
>   
>   #define I386_XSTATE_ALL_MASK    I386_XSTATE_MPX_MASK
>   
> @@ -44,11 +43,14 @@
>   
>   #define I386_XSTATE_MAX_SIZE	1088
>   
> +/* In case one of the MPX XCR0 bits is set we consider we have MPX.  */
> +#define HAS_MPX(XCR0) (((XCR0) & I386_XSTATE_MPX) == I386_XSTATE_BNDREGS) \
> +        || (((XCR0) & I386_XSTATE_MPX) == I386_XSTATE_BNDCFG)
> +#define HAS_AVX(XCR0) ((XCR0) & I386_XSTATE_AVX) == I386_XSTATE_AVX
> +
>   /* Get I386 XSAVE extended state size.  */
>   #define I386_XSTATE_SIZE(XCR0) \
> -    (((XCR0) & I386_XSTATE_BNDCFG) != 0 ? I386_XSTATE_BNDCFG_SIZE \
> -       : (((XCR0) & I386_XSTATE_BNDREGS) != 0 ? I386_XSTATE_BNDCFG_SIZE \
> -       : (((XCR0) & I386_XSTATE_AVX_SIZE) != 0 ? I386_XSTATE_AVX_SIZE \
> -       : I386_XSTATE_SSE_SIZE)))
> +    (HAS_MPX (XCR0) ? I386_XSTATE_BNDCFG_SIZE : \
> +     (HAS_AVX (XCR0) ? I386_XSTATE_AVX_SIZE : I386_XSTATE_SSE_SIZE))
>   
>   #endif /* I386_XSTATE_H */

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