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From: Florian Weimer <fweimer@redhat.com>
To: Andrew Pinski <pinskia@gmail.com>
Cc: gdb@sourceware.org,  Dmitry Belyavskiy <dbelyavs@redhat.com>
Subject: Re: Hardware watchpoints on GNU/Linux AArch64
Date: Mon, 02 Jan 2023 18:59:19 +0100	[thread overview]
Message-ID: <87v8lolsw8.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <87zgb0ltlm.fsf@oldenburg.str.redhat.com> (Florian Weimer's message of "Mon, 02 Jan 2023 18:44:05 +0100")

* 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.

GDB on bare-metal (on a different machine, not the hypervisor) has
hardware watchpoint support, as expected.

Probably the next step is to figure out what software is running on the
hypervisor.

Thanks,
Florian


  reply	other threads:[~2023-01-02 17:59 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-02 16:48 Florian Weimer
2023-01-02 17:08 ` Andreas Schwab
2023-01-02 17:22   ` Florian Weimer
2023-01-02 17:28 ` Andrew Pinski
2023-01-02 17:39   ` Andrew Pinski
2023-01-02 18:10     ` Andrew Pinski
2023-01-02 17:44   ` Florian Weimer
2023-01-02 17:59     ` Florian Weimer [this message]
2023-01-05 14:17 ` Luis Machado

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