在 2017/7/12 21:51, John Garry 写道: > On 10/07/2017 08:06, Yijing Wang wrote: >> >> static void sas_chain_event(int event, unsigned long *pending, >> @@ -592,9 +596,9 @@ int sas_discover_event(struct asd_sas_port *port, enum discover_event ev) >> { >> struct sas_discovery *disc; >> >> + disc = &port->disc; >> if (!port) >> return 0; >> - disc = &port->disc; >> >> BUG_ON(ev >= DISC_NUM_EVENTS); >> >> diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c >> index 570b2cb..9d26c28 1 > > I was just looking through the code and I noticed this, above. Is there a specific reason to move the NULL check, or was it modified accidentally? > > I mean, if port is NULL I don't think we would get as far as checking it as we would have already de-referenced it. Oh, sorry, it's a accidental change, good catch, thanks! > > > > . >