Re: [RFA/7.8] user breakpoint not inserted if software-single-step at same location

Joel Brobecker
2014-05-30T16:19:34Z

> I have a very simple idea, around "jump" + "always-inserted".
>
> E.g., with, where b+ indicates a user breakpoint:
>
> 00001 nop <- PC
> b+ 00002 nop
>
> - enable breakpoints always inserted mode
> - step to 00002
> - gdb removes the sss breakpoint.
> - due to always inserted mode, gdb does not remove b+, but
> due to the bug, it's actually no longer planted.
> - the b+ breakpoint should be reported to the user.
> - now do "jump $pc".
> - expected:
> The breakpoint should trigger immediately again.
> - what we get on sss targets:
> GDB loses control, and program runs to end.
>
> Ah, I just went ahead and tried that against my by sss-on-x86
> branch, and indeed it fails here, while it passes on
> pristine mainline / hardware stepping.

That is very clever! WDYT about pushing this new testcase now?

--
Joel