Re: GDB 8.1 release -- 2018-01-08 update

Pedro Alves
2018-01-08T16:35:00Z

On 01/08/2018 09:54 AM, Maciej W. Rozycki wrote:
> Hi Joel,
>
>> * [Maciej] remote/22597
>> Empty `qsThreadInfo' reply handling regression causing inability to execute
>>
>> I'm trying to understand whether this is specific to mips or more
>> general. And whether this only affects GDB when debugging with older
>> stubs or whether it affects us more generally.
>>
>> Depending on the answer, the issue might not be so severe as
>> to hold the release.
>>
>> Maciej - can you tell where we are on this issue, and whether
>> you think it really is blocking for 8.1?
>
> GDB uses the special thread ID 0, standing for `any', which older
> `gdbserver' versions do not recognise. It does not verify beforehand
> whether `gdbserver' supports this request and does not handle an error
> reply gracefully. Consequently an error reply to a `Hg0' packet issued
> causes GDB to lose track of what is going on, making it impossible to
> continue with the debug session. This happens with all sessions in the
> initial connection handshake, making the combination of new GDB and old
> `gdbserver' unusable.

I'm looking at this. I can reproduce it on x86-64 using a gdbserver
from 2007 (git hash "f8b73d13b7ca^", the same revision Maciej's
gdbserver is built from). I confirm that 5cd63fda035d somehow
introduces the regression. No idea why yet.

So not specific to MIPS.

Thanks,
Pedro Alves