Re: [PATCH v4 05/15] h8300: Process and signal

[Al Viro <viro@ZenIV.linux.org.uk>]

On Sat, Feb 21, 2015 at 04:53:49PM +0900, Yoshinori Sato wrote:

> +static inline void *
> +get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
> +{
> +	unsigned long usp;
> +
> +	/* Default to using normal stack.  */
> +	usp = rdusp();
> +
> +	/* This is the X/Open sanctioned signal stack switching.  */
> +	if (ka->sa.sa_flags & SA_ONSTACK) {
> +		if (!sas_ss_flags(usp))
> +			usp = current->sas_ss_sp + current->sas_ss_size;
> +	}

Use sigsp(), please.  Pass ksig to that sucker and it'll become
	return (void *)((sigsp(rdusp, ksig) - frame_size) & -8UL);

> +static void do_signal(struct pt_regs *regs)
> +	 * We want the common case to go fast, which
> +	 * is why we may in certain cases get here from
> +	 * kernel mode. Just return without doing anything
> +	 * if so.
> +	 */
> +	if ((regs->ccr & 0x10))
> +		return;

Can we get there in kernel mode, actually?