[Qemu-devel] gdbstub broken in master

[Qemu-devel] gdbstub broken in master

[Max Filippov]

Hi Andreas,

commit c52a6b67c1d7c6fc9fb2e3ba988d7b978e1487d3
Author: Andreas Färber <afaerber@suse.de>
Date:   Fri May 17 17:49:10 2013 +0200

    gdbstub: Simplify find_cpu()

    Use qemu_get_cpu() and CPUState::env_ptr.

    Reviewed-by: Richard Henderson <rth@twiddle.net>
    Signed-off-by: Andreas Färber <afaerber@suse.de>

breaks single-stepping in gdb. This commit replaces

        if (cpu_index(cpu) == thread_id) {

with qemu_get_cpu(thread_id) call, which does the following:

        if (cpu->cpu_index == index) {

while cpu_index(cpu) used to return cpu->cpu_index + 1;

-- 
Thanks.
-- Max

Re: [Qemu-devel] gdbstub broken in master

[Andreas Färber]

Hi Max,

Am 09.07.2013 01:37, schrieb Max Filippov:
> commit c52a6b67c1d7c6fc9fb2e3ba988d7b978e1487d3
> Author: Andreas Färber <afaerber@suse.de>
> Date:   Fri May 17 17:49:10 2013 +0200
> 
>     gdbstub: Simplify find_cpu()
> 
>     Use qemu_get_cpu() and CPUState::env_ptr.
> 
>     Reviewed-by: Richard Henderson <rth@twiddle.net>
>     Signed-off-by: Andreas Färber <afaerber@suse.de>
> 
> breaks single-stepping in gdb. This commit replaces
> 
>         if (cpu_index(cpu) == thread_id) {
> 
> with qemu_get_cpu(thread_id) call, which does the following:
> 
>         if (cpu->cpu_index == index) {
> 
> while cpu_index(cpu) used to return cpu->cpu_index + 1;

Ouch! Thanks for catching this, not sure how I managed to mix them up.

I've reverted this on qom-cpu (rebasing the first_cpu/next_cpu patch)
and dropped a queued patch replacing two find_cpu()s with that
qemu_get_cpu().
https://github.com/afaerber/qemu-cpu/commits/qom-cpu

The qom-cpu-11 branch has been updated to convert c_cpu, g_cpu and
find_cpu() to CPUState all in one go rather than replacing and dropping
the latter and doing the two fields separately. Can you give it a test?

Regards,
Andreas

-- 
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GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

Re: [Qemu-devel] gdbstub broken in master

[Max Filippov]

On Wed, Jul 10, 2013 at 1:47 AM, Andreas Färber <afaerber@suse.de> wrote:
> Hi Max,
>
> Am 09.07.2013 01:37, schrieb Max Filippov:
>> commit c52a6b67c1d7c6fc9fb2e3ba988d7b978e1487d3
>> Author: Andreas Färber <afaerber@suse.de>
>> Date:   Fri May 17 17:49:10 2013 +0200
>>
>>     gdbstub: Simplify find_cpu()
>>
>>     Use qemu_get_cpu() and CPUState::env_ptr.
>>
>>     Reviewed-by: Richard Henderson <rth@twiddle.net>
>>     Signed-off-by: Andreas Färber <afaerber@suse.de>
>>
>> breaks single-stepping in gdb. This commit replaces
>>
>>         if (cpu_index(cpu) == thread_id) {
>>
>> with qemu_get_cpu(thread_id) call, which does the following:
>>
>>         if (cpu->cpu_index == index) {
>>
>> while cpu_index(cpu) used to return cpu->cpu_index + 1;
>
> Ouch! Thanks for catching this, not sure how I managed to mix them up.
>
> I've reverted this on qom-cpu (rebasing the first_cpu/next_cpu patch)
> and dropped a queued patch replacing two find_cpu()s with that
> qemu_get_cpu().
> https://github.com/afaerber/qemu-cpu/commits/qom-cpu
>
> The qom-cpu-11 branch has been updated to convert c_cpu, g_cpu and
> find_cpu() to CPUState all in one go rather than replacing and dropping
> the latter and doing the two fields separately. Can you give it a test?

Ran basic tests with qemu-system-xtensa, appears to work.

-- 
Thanks.
-- Max