Re: [PATCH V1] gdbstub: suspended state support

[Alex Bennée]

Steve Sistare <steven.sistare@oracle.com> writes:

> Modify the gdb server so a continue command appears to resume execution
> when in RUN_STATE_SUSPENDED.  Do not print the next gdb prompt, but do not
> actually resume instruction fetch.  While in this "fake" running mode, a
> ctrl-C returns the user to the gdb prompt.

What exactly is the purpose of this? To hide the details of the runstate
as controlled by the user? I wouldn't expect someone using gdb debugging
not to also have control of the HMP/QMP interface.

>
> Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
> ---
>  gdbstub.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/gdbstub.c b/gdbstub.c
> index f3a318c..2f0d9ff 100644
> --- a/gdbstub.c
> +++ b/gdbstub.c
> @@ -461,7 +461,9 @@ static inline void gdb_continue(void)
>  #else
>      if (!runstate_needs_reset()) {
>          trace_gdbstub_op_continue();
> -        vm_start();
> +        if (!runstate_check(RUN_STATE_SUSPENDED)) {
> +            vm_start();
> +        }
>      }
>  #endif
>  }
> @@ -490,7 +492,7 @@ static int gdb_continue_partial(char *newstates)
>      int flag = 0;
>  
>      if (!runstate_needs_reset()) {
> -        if (vm_prepare_start()) {
> +        if (!runstate_check(RUN_STATE_SUSPENDED) && vm_prepare_start()) {
>              return 0;
>          }
>  
> @@ -2835,6 +2837,9 @@ static void gdb_read_byte(uint8_t ch)
>          /* when the CPU is running, we cannot do anything except stop
>             it when receiving a char */
>          vm_stop(RUN_STATE_PAUSED);
> +    } else if (runstate_check(RUN_STATE_SUSPENDED) && ch == 3) {
> +        /* Received ctrl-c from gdb */
> +        gdb_vm_state_change(0, 0, RUN_STATE_PAUSED);
>      } else
>  #endif
>      {
> @@ -3282,6 +3287,8 @@ static void gdb_sigterm_handler(int signal)
>  {
>      if (runstate_is_running()) {
>          vm_stop(RUN_STATE_PAUSED);
> +    } else if (runstate_check(RUN_STATE_SUSPENDED)) {
> +        gdb_vm_state_change(0, 0, RUN_STATE_PAUSED);
>      }
>  }
>  #endif


-- 
Alex Bennée