Re: [PATCH 20/27] ptrace: arch_has_block_step

[David Wilder <dwilder@us.ibm.com>]

Roland McGrath wrote:
<snip>
> 
> +#ifndef arch_has_block_step
> +/**
> + * arch_has_block_step - does this CPU support user-mode block-step?
> + *
> + * If this is defined, then there must be a function declaration or inline
> + * for user_enable_block_step(), and arch_has_single_step() must be defined
> + * too.  arch_has_block_step() should evaluate to nonzero iff the machine
> + * supports step-until-branch for user mode.  It can be a constant or it
> + * can test a CPU feature bit.
> + */
> +#define arch_has_single_step()		(0)

should this be #define arch_has_block_step()		(0)

> +
> +/**
> + * user_enable_block_step - step until branch in user-mode task
> + * @task: either current or a task stopped in %TASK_TRACED
> + *
> + * This can only be called when arch_has_block_step() has returned nonzero,
> + * and will never be called when single-instruction stepping is being used.
> + * Set @task so that when it returns to user mode, it will trap after the
> + * next branch or trap taken.
> + */
> +static inline void user_enable_block_step(struct task_struct *task)
> +{
> +	BUG();			/* This can never be called.  */
> +}
> +#endif	/* arch_has_block_step */
> +
<snip>