Re: [PATCH v5 01/12] libtracefs: New APIs for dynamic events

[Steven Rostedt <rostedt@xxxxxxxxxxx>]

On Fri,  5 Nov 2021 14:16:13 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx> wrote:

> +static struct dyn_events_desc *get_devent_desc(enum tracefs_dynevent_type type)
> +{
> +
> +	static bool init;
> +
> +	if (type >= TRACEFS_DYNEVENT_MAX)

We can not rely on enums being signed or unsigned, so the above needs to be:

	if ((unsigned int)type >= TRACEFS_DYNEVENT_MAX)

> +		return NULL;


And we should also not undefined types (more than one type masked in), so
we really need an unsigned int:

	unsigned int t = type;

	if (t & (t - 1))
		return NULL;

	if (t >= TRACEFS_DYNEVENT_MAX)
		return NULL;

-- Steve


> +
> +	if (!init) {
> +		init_devent_desc();
> +		init = true;
> +	}
> +
> +	return &dynevents[ffs(type) - 1];
> +}