Subject: Re: [PATCH 6/15] hypervisor console driver for Celleb

From: [email-masked] (Linas Vepstas)
Date: Tue, 12 Dec 2006 13:41:07 -0600

On Tue, Dec 12, 2006 at 12:31:29PM +0900, Ishizaki Kou wrote:
> +
> +static int hvc_beat_get_chars(uint32_t vtermno, char *buf, int cnt)
> +{
> +	unsigned long kb[2];
> +	unsigned long got;
> +
> +	if (beat_get_term_char(vtermno, &got, &kb[0], &kb[1]) == 0) {
> +		memcpy(buf, kb, got);
> +		return got;

This seems to completely ignore "cnt". Thus, I presume that
beat_get_term_char might return more chars than there is room for in buf,
thus corrupting something, somewhere.

> +static int hvc_beat_put_chars(uint32_t vtermno, const char *buf, int cnt)
> +{
> +	unsigned long kb[2];
> +
> +	memcpy(kb, buf, sizeof(kb));
> +	beat_put_term_char(vtermno, cnt, kb[0], kb[1]);
> +	return cnt;
> +}

I can't imagine how this can possibly work. 
What if "cnt" is greater than 8?

--linas