Re: [PATCH] gdbstub: Permit reverse step/break to provide stop response

[Matheus Tavares Bernardino]

> Nicholas Piggin <npiggin@gmail.com> wrote:
>
> The final part of the reverse step and break handling is to bring
> the machine back to a debug stop state. gdb expects a response.
> 
> A gdb 'rsi' command hangs forever because the gdbstub filters out
> the response (also observable with reverse_debugging.py avocado
> tests).
> 
> Fix by setting allow_stop_reply for the gdb backward packets.

Ah, it's interesting that [1] doesn't include 'bc' and 'bs' in the list
of cmds that may respond with a stop-reply packet:

    "The 'C', 'c', 'S', 's', 'vCont', 'vAttach', 'vRun', 'vStopped', and
    '?' packets can receive any of the below as a reply."

But their definitions at [2] do say the following:

    'bc' (and 'bc')
    [...]
    Reply: See Stop Reply Packets, for the reply specifications.

So I guess the list from [1] is not exhaustive. Anyway, thanks for the
fix!

Acked-by: Matheus Tavares Bernardino <quic_mathbern@quicinc.com>

[1]: 
https://sourceware.org/gdb/onlinedocs/gdb/Stop-Reply-Packets.html#Stop-Reply-Packets
[2]: https://sourceware.org/gdb/onlinedocs/gdb/Packets.html#Packets