Re: [Qemu-devel] [PATCH 3/3] target-i386:slightly refactor dr7 related function

["陳韋任 (Wei-Ren Chen)" <chenwj@iis.sinica.edu.tw>]

On Thu, Dec 06, 2012 at 05:27:44PM +0800, li guang wrote:
> 在 2012-12-06四的 09:23 +0000，Peter Maydell写道：
> > On 6 December 2012 09:16, li guang <lig.fnst@cn.fujitsu.com> wrote:
> > > 在 2012-12-06四的 08:54 +0000，Peter Maydell写道：
> > >> On 6 December 2012 03:03, liguang <lig.fnst@cn.fujitsu.com> wrote:
> > >> > Signed-off-by: liguang <lig.fnst@cn.fujitsu.com>
> > >> > --- a/target-i386/seg_helper.c
> > >> > +++ b/target-i386/seg_helper.c
> > >> > @@ -465,9 +465,9 @@ static void switch_tss(CPUX86State *env, int tss_selector,
> > >> >
> > >> >  #ifndef CONFIG_USER_ONLY
> > >> >      /* reset local breakpoints */
> > >> > -    if (env->dr[7] & 0x55) {
> > >> > -        for (i = 0; i < 4; i++) {
> > >> > -            if (hw_breakpoint_enabled(env->dr[7], i) == 0x1) {
> > >> > +    if (env->dr[7] & DR7_LOCAL_BP_MASK) {
> > >> > +        for (i = 0; i < DR7_MAX_BP; i++) {
> > >> > +            if (hw_breakpoint_enabled(env->dr[7], i)) {
> > >> >                  hw_breakpoint_remove(env, i);
> > >> >              }
> > >> >          }
> > >>
> > >> This is still wrong.
> > >
> > > do you mean the use of 'hw_breakpoint_enabled'? or others?
> > > maybe a mistake, I change it to 'hw_local_breakpoint_enabled'.
> > > if it is I'll re-send a corrected patch.
> > 
> > I mean that in the comments on the previous version of this
> > patchseet we explained that this check is specifically checking
> > for whether the breakpoint is enabled locally, and that your
> > change to just returning bool broke this. And in this version
> > of the patch there is still exactly the same problem.
> 
> why broke?
> this function just ask if breakpoint 'i' was enable,
> so we answer enabled or not? 2 simple cases, any problem?

  I don't read this patch from the starting. But Peter, do you mean
the return value matters here? I see the original version compares
the return value with 0x1, do you mean we *need* this comparsion here?

Regards,
chenwj

-- 
Wei-Ren Chen (陳韋任)
Computer Systems Lab, Institute of Information Science,
Academia Sinica, Taiwan (R.O.C.)
Tel:886-2-2788-3799 #1667
Homepage: http://people.cs.nctu.edu.tw/~chenwj