Re: [Qemu-devel] [PATCH]bug fix for softmmu slow_st unaligned access

[andrzej zaborowski]

Hi,

On 28/10/2007, TeLeMan <address@hidden> wrote:
> For example, the memory address 0x10008000 is on an unwritable page.When the
> instruction "add dword ptr [0x10007FFF],0x12345678" is executed,the OS will
> set 0x10008000 page be a writable page and re-execute this instruction. But
> softmmu has modifed the value of 0x10007FFF,so after re-executing this
> instruction, the final result is wrong(double-added on 0x10007FFF).
> Reversing the stored byte order can fix this bug.

I'm not sure I understand, but what happens if now the 10008000 page
is writable and 10007fff isn't, thus the OS needs to make it writable
and re-execute? I guess reversing the accesses order is not a
solution?

Regards,
Andrew