Re: [Qemu-devel] [PATCH] colo-compare: fix the dangerous assignment

[Mao Zhongyi]

On 11/16/2017 06:13 PM, Darren Kenny wrote:
> On Thu, Nov 16, 2017 at 10:28:32AM +0800, Mao Zhongyi wrote:
> > Cc: Peter Maydell <address@hidden>
> > Cc: Jason Wang <address@hidden>
> > Cc: Zhang Chen <address@hidden>
> > Cc: Li Zhijian <address@hidden>
> > Cc: Paolo Bonzini <address@hidden>
> > Fixes: 8ec14402029d783720f4312ed8a925548e1dad61
> > Reported-by: Peter Maydell <address@hidden>
> > Reported-by: Paolo Bonzini <address@hidden>
> > Signed-off-by: Mao Zhongyi <address@hidden>
>
> Code-wise, this looks like a valid fix to the existing code.
>
> Reviewed-by: Darren Kenny <address@hidden>

Hi, Darren

> But testing wise, have you confirmed that things are behaving as you
> expected with the previous patch, since previously when calling
> colo_compare_connection(), the value of conn would have always been
> its initialized value of NULL.

Well, in my test machine the code like *con = conn, but when I made
the patch on another machine I wrote the code con = &conn carelessly.

> Just want to be sure that fixing this doesn't end up breaking your
> expected behaviour given that all your testing before would have had
> a NULL value in conn.

Thanks for the kind reminder.

Thanks,
Mao

> Thanks,
>
> Darren.
>
> > ---
> > net/colo-compare.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/net/colo-compare.c b/net/colo-compare.c
> > index ccdcba2..1ce195f 100644
> > --- a/net/colo-compare.c
> > +++ b/net/colo-compare.c
> > @@ -179,7 +179,7 @@ static int packet_enqueue(CompareState *s, int mode, 
> > Connection **con)
> >                          "drop packet");
> >         }
> >     }
> > -    con = &conn;
> > +    *con = conn;
> >
> >     return 0;
> > }
> > --
> > 2.9.4