Hardware watchpoints on GNU/Linux AArch64

[Florian Weimer]

* Andrew Pinski:

> On Mon, Jan 2, 2023 at 8:49 AM Florian Weimer via Gdb
> <gdb@sourceware.org> wrote:
>>
>> Running
>>
>> gdb-12.1-10.fc38.aarch64
>> kernel-6.2.0-0.rc1.20221230gitbff687b3dad6.15.fc38.aarch64
>>
>> I do not seem to be able to use hardware watchpoints.  GDB just logs
>> warnings:
>>
>> warning: Unable to determine the number of hardware watchpoints available.
>> warning: Unable to determine the number of hardware breakpoints available.
>
> This shows up when the ptrace either fails or ptrace returns an
> unknown value for AARCH64_DEBUG_ARCH value.
> In the boot log there should be a message saying how many HW
> breakpoint and watchpoints there are and what version of the debug
> arch is there.

I only see this in the kernel log:

hw-breakpoint: found 6 breakpoint and 4 watchpoint registers.

Nothing else in the vicinity.

Thanks,
Florian