Re: [Qemu-devel] [PATCH for-3.0 3/4] tests: only update last_byte when at the edge

[Juan Quintela]

Peter Xu <address@hidden> wrote:
> The only possible change of last_byte is when it reaches the edge.
> Setting it every time might let last_byte contain an invalid data when
> memory corruption is detected, then the check of the next byte will be
> incorrect.  For example, a single page corruption at address 0x14ad000
> will also lead to a "fake" corruption at 0x14ae000:
>
>   Memory content inconsistency at 14ad000 first_byte = 44 last_byte = 44 
> current = ef hit_edge = 0
>   Memory content inconsistency at 14ae000 first_byte = 44 last_byte = ef 
> current = 44 hit_edge = 0
>
> After the patch, it'll only report the corrputed page:
>
>   Memory content inconsistency at 14ad000 first_byte = 44 last_byte = 44 
> current = ef hit_edge = 0
>
> Signed-off-by: Peter Xu <address@hidden>

Reviewed-by: Juan Quintela <address@hidden>

Good catch.  I was having this problem in the past, but never
investigated the problem so far.