Re: [PATCH] xen-fbfront: correct return value checks on xenbus_scanf()

quoted

quoted

On 07.07.16 at 11:42, [off-list ref] wrote:

On 07/07/16 09:48, Jan Beulich wrote:

quoted

Only a positive return value indicates success.

Hmm, I'm not convinced on this change (and the similar others as
well). From xenbus.h:

/* Single read and scanf: returns -errno or num scanned if > 0. */

There should be no case for xenbus_scanf() returning 0. And looking
into the functions proofs this is correct.

I don't think it is appropriate for callers to assume a currently
impossible return value indicates success.

Jan