RE: [PATCH v3 07/12] btrace, gdbserver: Add ptwrite to btrace_config_pt.

["Metzger, Markus T" <markus.t.metzger@intel.com>]

Hello Felix,

>> >@@ -7096,6 +7096,7 @@ linux_process_target::read_btrace_conf (const
>> >btrace_target_info *tinfo,
>> > 	case BTRACE_FORMAT_PT:
>> > 	  buffer_xml_printf (buffer, "<pt");
>> > 	  buffer_xml_printf (buffer, " size=\"0x%x\"", conf->pt.size);
>> >+	  buffer_xml_printf (buffer, " ptwrite=\"%d\"", conf->pt.ptwrite);
>>
>> Would we need to guard that with a check whether GDB supports this new
>> attribute?
>> Have you tried mixing an old GDB and a new gdbserver?
>
>I don't see how we could guard here.
>If I use master for GDB and master + ptwrite for gdbserver,
>recording and the history commands work without error message.
>That might just mean that there is no length check on GDB side.
>But that won't be added to old GDBs anyway.

I think the answer is that unknown attributes will get ignored so we should be fine.

Let's also check the other direction where GDB would be able to handle the new
ptwrite attribute but gdbserver doesn't provide it.

Regards,
Markus.

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