| Date | Thu, 10 Dec 2020 20:26:04 +0100 | From | Thomas Gleixner <> | Subject | [patch 28/30] xen/events: Reduce irq_info::spurious_cnt storage size |
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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 <tglx@linutronix.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: xen-devel@lists.xenproject.org --- drivers/xen/events/events_base.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
--- 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(struc 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)
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