Re: [PATCH v3 01/11] gdbstub: Support disablement in a multi-threaded process

[Richard Henderson <richard.henderson@linaro.org>]

On 2/16/24 03:05, Ilya Leoshkevich wrote:
> The upcoming follow-fork-mode child support will require disabling
> gdbstub in the parent process, which may have multiple threads (which
> are represented as CPUs).
> 
> Loop over all CPUs in order to remove breakpoints and disable
> single-step. Move the respective code into a separate function.
> 
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> ---
>   gdbstub/user.c | 19 +++++++++++++++----
>   1 file changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/gdbstub/user.c b/gdbstub/user.c
> index 14918d1a217..e17f7ece908 100644
> --- a/gdbstub/user.c
> +++ b/gdbstub/user.c
> @@ -356,16 +356,27 @@ int gdbserver_start(const char *port_or_path)
>       return -1;
>   }
>   
> +static void disable_gdbstub(void)
> +{
> +    CPUState *cpu;
> +
> +    close(gdbserver_user_state.fd);
> +    gdbserver_user_state.fd = -1;
> +    CPU_FOREACH(cpu) {
> +        cpu_breakpoint_remove_all(cpu, BP_GDB);
> +        /* no cpu_watchpoint_remove_all for user-mode */
> +        cpu_single_step(cpu, 0);
> +        tb_flush(cpu);

You only need to flush once.  The cpu argument is used to determine if we can perform the 
flush immediately or need to queue it.

Otherwise,
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~