[PATCH/RFC] Improve the "thread_step_needed" logic
Daniel Jacobowitz
dmj+@andrew.cmu.edu
Sat Jun 16 11:58:00 GMT 2001
On Fri, Jun 15, 2001 at 06:13:56PM -0700, Michael Snyder wrote:
> > <sigh>
> >
> > While you're fixing this, could you please address my issue from last
> > week with this code? Checking "step" at this point in resume() is not
> > correct, since it will have been cleared if SOFTWARE_SINGLE_STEP_P ().
> >
> > > --- 879,913 ----
> > > if (should_resume)
> > > {
> > > ptid_t resume_ptid;
> > > +
> > > + resume_ptid = RESUME_ALL; /* Default */
> > >
> > > ! if ((step || singlestep_breakpoints_inserted_p) &&
> > > ! !breakpoints_inserted && breakpoint_here_p (read_pc ()))
> >
> > > +
> > > + #ifdef CANNOT_STEP_BREAKPOINT
> > > + /* Most targets can step a breakpoint instruction, thus executing it
> > > + normally. But if this one cannot, just continue and we will hit
> > > + it anyway. */
> > > + if (step && breakpoints_inserted && breakpoint_here_p (read_pc ()))
> > > + step = 0;
> > > + #endif
> >
> > Specifically, those bits.
>
> Oh, sorry, I missed this part of your msg.
> Well, this isn't related to SOFTWARE_SINGLESTEP_P,
> it's a separate issue. But if you'll notice, I believe this is also
> handled correctly, because my "thread_step_needed" test includes
> (NOT breakpoints_inserted), while this CANNOT_STEP_BREAKPOINT clause
> will only be taken if breakpoints_inserted is true. So they are
> mutually exclusive, if you will. I tested this on Alpha Linux, which
> does NOT use software single step, but DOES use CANNOT_STEP_BREAKPOINT,
> and it works.
My apologies. I need to read closer before replying :)
I'm assuming that singlestep_breakpoints_inserted_p is zero normally
upon entering resume - that only makes sense. In that case, your
change preserves the exact behavior I was asking for. I'm going to run
it through the testsuite on MIPS/Linux, which I've finally gotten into
(almost) functional shape, and let you know if something breaks - I
expect that it will not break, though.
--
Daniel Jacobowitz Debian GNU/Linux Developer
Monta Vista Software Debian Security Team
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