Re: [PATCH v1 2/6] configure: gate our use of GDB to 8.3.1 or above

[Peter Maydell]

On Mon, 14 Dec 2020 at 17:08, Alex Bennée <alex.bennee@linaro.org> wrote:
>
>
> Peter Maydell <peter.maydell@linaro.org> writes:
>
> > On Mon, 14 Dec 2020 at 15:36, Alex Bennée <alex.bennee@linaro.org> wrote:
> >>
> >> Certain earlier versions of GDB have (possibly distro) derived issues
> >> when running against multiarch guests. Also given the problem of
> >> clashing ports it is preferable to use socket comms rather than TCP
> >> ports for testing.
> >
> > What's a "multiarch guest" ?
>
> I guess non-native guest would be another way of saying it. There is
> some hoop jumping to deal with the fact that some arches package up a
> fully featured multiarch aware gdb and some package up the multiarch one
> as a separate gdb-multiarch package.
>
> > Incidentally I think the problem I have been running into
> > with the Ubuntu gdb 8.1 is that it doesn't support registers
> > larger than 64 bytes, and if AArch64 QEMU is emulating SVE
> > then it tries to expose registers bigger than that to the
> > gdbstub.
>
> So this is a missing patch from Ubuntu's gdb?

No, upstream 8.1 doesn't handle this either and crashes too.
I'm a bit surprised we haven't had user complaints, since
gdb+QEMU would have previously worked and then started to
crash gdb when we put in the SVE registers.

> We could just peg the sha1 test to cortex-a57 - your are likely not
> getting the SVE tests running unless you have the compilers to build
> them (or using docker).

Yeah, forcing a non-SVE CPU should allow the test to work with this gdb.

thanks
-- PMM