Re: [PATCH for-5.2 1/3] linux-user/sparc: Fix errors in target_ucontext structures

[Richard Henderson <richard.henderson@linaro.org>]

On 11/5/20 1:23 PM, Peter Maydell wrote:
> The various structs that make up the SPARC target_ucontext had some
> errors:
>  * target structures must not include fields which are host pointers,
>    which might be the wrong size.  These should be abi_ulong instead
>  * because we don't have the 'long double' part of the mcfpu_fregs
>    union in our version of the target_mc_fpu struct, we need to
>    manually force it to be 16-aligned
> 
> In particular, the lack of 16-alignment caused sparc64_get_context()
> and sparc64_set_context() to read and write all the registers at the
> wrong offset, which triggered a guest glibc stack check in
> siglongjmp:
>   *** longjmp causes uninitialized stack frame ***: terminated
> when trying to run bash.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

> +} __attribute__((aligned(16)));

Hmph, 96 uses of the attribute directly, 20 uses of QEMU_ALIGNED.  I suppose we
should just remove the wrapper...


r~