From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Julien Grall <julien@xen.org>,
Juergen Gross <jgross@suse.com>,
Boris Ostrovsky <boris.ostrvsky@oracle.com>
Subject: [PATCH 4.4 3/4] xen/events: reset active flag for lateeoi events later
Date: Fri, 9 Jul 2021 15:18:15 +0200 [thread overview]
Message-ID: <20210709131535.098023418@linuxfoundation.org> (raw)
In-Reply-To: <20210709131529.395072769@linuxfoundation.org>
From: Juergen Gross <jgross@suse.com>
commit 3de218ff39b9e3f0d453fe3154f12a174de44b25 upstream.
In order to avoid a race condition for user events when changing
cpu affinity reset the active flag only when EOI-ing the event.
This is working fine as all user events are lateeoi events. Note that
lateeoi_ack_mask_dynirq() is not modified as there is no explicit call
to xen_irq_lateeoi() expected later.
Cc: stable@vger.kernel.org
Reported-by: Julien Grall <julien@xen.org>
Fixes: b6622798bc50b62 ("xen/events: avoid handling the same event on two cpus at the same time")
Tested-by: Julien Grall <julien@xen.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrvsky@oracle.com>
Link: https://lore.kernel.org/r/20210623130913.9405-1-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/xen/events/events_base.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -533,6 +533,9 @@ static void xen_irq_lateeoi_locked(struc
}
info->eoi_time = 0;
+
+ /* is_active hasn't been reset yet, do it now. */
+ smp_store_release(&info->is_active, 0);
do_unmask(info, EVT_MASK_REASON_EOI_PENDING);
}
@@ -1777,10 +1780,22 @@ static void lateeoi_ack_dynirq(struct ir
struct irq_info *info = info_for_irq(data->irq);
evtchn_port_t evtchn = info ? info->evtchn : 0;
- if (VALID_EVTCHN(evtchn)) {
- do_mask(info, EVT_MASK_REASON_EOI_PENDING);
- ack_dynirq(data);
- }
+ if (!VALID_EVTCHN(evtchn))
+ return;
+
+ do_mask(info, EVT_MASK_REASON_EOI_PENDING);
+
+ if (unlikely(irqd_is_setaffinity_pending(data)) &&
+ likely(!irqd_irq_disabled(data))) {
+ do_mask(info, EVT_MASK_REASON_TEMPORARY);
+
+ clear_evtchn(evtchn);
+
+ irq_move_masked_irq(data);
+
+ do_unmask(info, EVT_MASK_REASON_TEMPORARY);
+ } else
+ clear_evtchn(evtchn);
}
static void lateeoi_mask_ack_dynirq(struct irq_data *data)
next prev parent reply other threads:[~2021-07-09 13:18 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-09 13:18 [PATCH 4.4 0/4] 4.4.275-rc1 review Greg Kroah-Hartman
2021-07-09 13:18 ` [PATCH 4.4 1/4] scsi: sr: Return appropriate error code when disk is ejected Greg Kroah-Hartman
2021-07-09 13:18 ` [PATCH 4.4 2/4] drm/nouveau: fix dma_address check for CPU/GPU sync Greg Kroah-Hartman
2021-07-09 13:18 ` Greg Kroah-Hartman [this message]
2021-07-09 13:18 ` [PATCH 4.4 4/4] arm: kprobes: Allow to handle reentered kprobe on single-stepping Greg Kroah-Hartman
2021-07-09 14:57 ` [PATCH 4.4 0/4] 4.4.275-rc1 review Pavel Machek
2021-07-09 21:44 ` Shuah Khan
2021-07-10 19:50 ` Guenter Roeck
2021-07-11 2:39 ` Naresh Kamboju
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