Re: [Qemu-devel] [PATCH] i386: fix breakpoints handling in icount mode

[Frederic Konrad <fred.konrad@greensocs.com>]

On 22/10/2014 13:38, Pavel Dovgalyuk wrote:

Hi Pavel,
> This patch fixes instructions counting when execution is stopped on
> breakpoint (e.g. set from gdb). Without a patch extra instruction is translated
> and icount is incremented by invalid value (which equals to number of
> executed instructions + 1).
>
> Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
> ---
>   target-i386/translate.c |    3 ++-
>   1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/target-i386/translate.c b/target-i386/translate.c
> index 1284173..193cf9f 100644
> --- a/target-i386/translate.c
> +++ b/target-i386/translate.c
> @@ -8000,7 +8000,7 @@ static inline void gen_intermediate_code_internal(X86CPU *cpu,
>                   if (bp->pc == pc_ptr &&
>                       !((bp->flags & BP_CPU) && (tb->flags & HF_RF_MASK))) {
>                       gen_debug(dc, pc_ptr - dc->cs_base);
> -                    break;
> +                    goto done_generating;
This makes sense to me.
But I don't see why you don't just "break" like the other instruction in 
this loop?

>                   }
>               }
>           }
> @@ -8049,6 +8049,7 @@ static inline void gen_intermediate_code_internal(X86CPU *cpu,
>               break;
>           }
>       }
> +done_generating:
>       if (tb->cflags & CF_LAST_IO)
>           gen_io_end();
Is there any reason why you don't jump over this two lines in case of a
breakpoint?

>       gen_tb_end(tb, num_insns);
>
>

I'll give it a try later and I'll let you know.

Thanks,
Fred