Re: [PATCH v3 19/20] gdbstub: Implement qGDBServerVersion packet

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 21/5/25 17:42, Alex Bennée wrote:
> From: Dominik 'Disconnect3d' Czarnota <dominik.b.czarnota@gmail.com>
> 
> This commit adds support for the `qGDBServerVersion` packet to the qemu
> gdbstub  which could be used by clients to detect the QEMU version
> (and, e.g., use a workaround for known bugs).
> 
> This packet is not documented/standarized by GDB but it was implemented
> by LLDB gdbstub [0] and is helpful for projects like Pwndbg [1].
> 
> This has been implemented by Patryk, who I included in Co-authored-by
> and who asked me to send the patch.
> 
> [0] https://lldb.llvm.org/resources/lldbgdbremote.html#qgdbserverversion
> [1] https://github.com/pwndbg/pwndbg/issues/2648
> 
> Co-authored-by: Patryk 'patryk4815' Sondej <patryk.sondej@gmail.com>
> Signed-off-by: Dominik 'Disconnect3d' Czarnota <dominik.b.czarnota@gmail.com>
> Message-Id: <20250403191340.53343-1-dominik.b.czarnota@gmail.com>
> [AJB: fix include, checkpatch linewrap]
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> ---
>   gdbstub/gdbstub.c | 17 +++++++++++++++++
>   1 file changed, 17 insertions(+)
> 
> diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
> index 6023c80d25..def0b7e877 100644
> --- a/gdbstub/gdbstub.c
> +++ b/gdbstub/gdbstub.c
> @@ -28,6 +28,7 @@
>   #include "qemu/cutils.h"
>   #include "qemu/module.h"
>   #include "qemu/error-report.h"
> +#include "qemu/target-info.h"
>   #include "trace.h"
>   #include "exec/gdbstub.h"
>   #include "gdbstub/commands.h"
> @@ -1597,6 +1598,18 @@ static void handle_query_threads(GArray *params, void *user_ctx)
>       gdbserver_state.query_cpu = gdb_next_attached_cpu(gdbserver_state.query_cpu);
>   }
>   
> +static void handle_query_gdb_server_version(GArray *params, void *user_ctx)
> +{
> +#if defined(CONFIG_USER_ONLY)
> +    g_string_printf(gdbserver_state.str_buf, "name:qemu-%s;version:%s;",
> +                    target_name(), QEMU_VERSION);
> +#else
> +    g_string_printf(gdbserver_state.str_buf, "name:qemu-system-%s;version:%s;",
> +                    target_name(), QEMU_VERSION);
> +#endif

g_string_printf() isn't really justified, we usually call
g_string_append().

> +    gdb_put_strbuf();
> +}