Re: [Qemu-devel] latest qemu with gdb remote not working

[Paolo Bonzini <pbonzini@redhat.com>]

Il 03/06/2013 09:42, Peter Crosthwaite ha scritto:
> Hi Peter and Peter :)
> 
> On Sun, Jun 2, 2013 at 7:27 PM, Peter Maydell <peter.maydell@linaro.org> wrote:
>> On 2 June 2013 06:46, Peter Cheung <mcheung63@hotmail.com> wrote:
>>>     I just tried to compile the latest qemu on Fedora 18 64 bits,
>>> it is also fail. When i press "c" in gdb, the qemu won't start
>>> running.
>>
>> Good. This significantly increases the chances that somebody
>> will investigate.
> 
> I think I may have replicated as well. qemu-system-arm on Ubuntu 10.04 host.
> And it works again for me after a revert of:
> 
> commit 87f25c12bfeaaa0c41fb857713bbc7e8a9b757dc
> Author: Paolo Bonzini <pbonzini@redhat.com>
> Date:   Thu May 30 13:20:40 2013 +0200
> 
>     gdbstub: do not restart crashed guest
> 
>     If a guest has crashed with an internal error or similar, detaching
>     gdb (or any other debugger action) should not restart it.
> 
>     Cc: Jan Kiszka <jan.kiszka@siemens.com>
>     Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>     Reviewed-by: Laszlo Ersek <lersek@redhat.com>
>     Message-id: 1369912840-18577-1-git-send-email-pbonzini@redhat.com
>     Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

Oops, indeed you need to type cont in both gdb and the monitor after
this patch.  Funny I didn't notice; the fix should be to use
!runstate_needs_reset() instead of runstate_check(RUN_STATE_DEBUG).

But it is likely a different bug than the Mac OS X one.

Paolo

> Ill dig further before sending through minimal replication
> instructions (gotta run!)
> but Peter Cheung, can you please try your test case after reverting this commit,
> to see if its perhaps the same bug?
> 
> $ git revert 87f25c12bfeaaa0c41fb857713bbc7e8a9b757dc
> 
> Regards,
> Peter
> 
>>
>>> But one thing fedora is different than mac, when i connect gdb to qemu, it
>>> won't say "warning: Error 268435459 getting port names from mach_port_names"
>>
>> That looks like a Mac GDB specific issue.
>>
>>> In my mac, i use gcc from mac port, here is the version detail:
>>>
>>> /Users/peter>gcc -v
>>
>>> gcc version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.1.00)
>>
>> This is pretty ancient -- I'd suggest using clang to build
>> QEMU instead. (It probably won't fix your problem here, though.)
>>
>> What command line are you using to configure and build QEMU?
>>
>> thanks
>> -- PMM
>>