From 62ebcda8a8dfa4aeaa3288020a082787910afebc Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 10 Dec 2020 20:26:04 +0100 Subject: xen/events: Reduce irq_info:: Spurious_cnt storage size To prepare for interrupt spreading reduce the storage size of irq_info::spurious_cnt to u8 so the required flag for the spreading logic will not increase the storage size. Protect the usage site against overruns. Signed-off-by: Thomas Gleixner Cc: Boris Ostrovsky Cc: Juergen Gross Cc: Stefano Stabellini Link: https://lore.kernel.org/r/20201210194045.360198201@linutronix.de --- drivers/xen/events/events_base.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'drivers/xen') diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 679b2cbd2de4..b352440963ee 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -95,7 +95,7 @@ struct irq_info { struct list_head list; struct list_head eoi_list; short refcnt; - short spurious_cnt; + u8 spurious_cnt; enum xen_irq_type type; /* type */ unsigned irq; evtchn_port_t evtchn; /* event channel */ @@ -528,8 +528,10 @@ static void xen_irq_lateeoi_locked(struct irq_info *info, bool spurious) return; if (spurious) { - if ((1 << info->spurious_cnt) < (HZ << 2)) - info->spurious_cnt++; + if ((1 << info->spurious_cnt) < (HZ << 2)) { + if (info->spurious_cnt != 0xFF) + info->spurious_cnt++; + } if (info->spurious_cnt > 1) { delay = 1 << (info->spurious_cnt - 2); if (delay > HZ) -- cgit v1.2.3