Re: [PATCH v2 01/11] arm64: debug: clean up single_step_handler logic

[Will Deacon <will@kernel.org>]

On Mon, May 12, 2025 at 06:43:16PM +0100, Ada Couprie Diaz wrote:
> Remove the unnecessary boolean which always checks if the handler was found
> and return early instead.
> 
> Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
> ---
>  arch/arm64/kernel/debug-monitors.c | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
> index 58f047de3e1c..676fa0231935 100644
> --- a/arch/arm64/kernel/debug-monitors.c
> +++ b/arch/arm64/kernel/debug-monitors.c
> @@ -241,8 +241,6 @@ static void send_user_sigtrap(int si_code)
>  static int single_step_handler(unsigned long unused, unsigned long esr,
>  			       struct pt_regs *regs)
>  {
> -	bool handler_found = false;
> -
>  	/*
>  	 * If we are stepping a pending breakpoint, call the hw_breakpoint
>  	 * handler first.
> @@ -250,10 +248,10 @@ static int single_step_handler(unsigned long unused, unsigned long esr,
>  	if (!reinstall_suspended_bps(regs))
>  		return 0;
>  
> -	if (!handler_found && call_step_hook(regs, esr) == DBG_HOOK_HANDLED)
> -		handler_found = true;
> +	if (call_step_hook(regs, esr) == DBG_HOOK_HANDLED)
> +		return 0;
>  
> -	if (!handler_found && user_mode(regs)) {
> +	if (user_mode(regs)) {
>  		send_user_sigtrap(TRAP_TRACE);
>  
>  		/*
> @@ -263,7 +261,7 @@ static int single_step_handler(unsigned long unused, unsigned long esr,
>  		 * to the active-not-pending state).
>  		 */
>  		user_rewind_single_step(current);
> -	} else if (!handler_found) {
> +	} else {

Crikey, this code is totally bizarre! Thanks for cleaning it up.

Will