[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: Linux 6.7-rc1+: WARNING at drivers/xen/evtchn.c:167 evtchn_interrupt
On Tue, Mar 12, 2024 at 02:10:02PM +0100, Juergen Gross wrote: > On 30.11.23 03:34, Marek Marczykowski-Górecki wrote: > > Hi, > > > > While testing 6.7-rc3 on Qubes OS I found several warning like in the > > subject in dom0 log. I see them when running 6.7-rc1 too. I'm not sure > > what exactly triggers the issue, but my guess would be unbinding an > > event channel from userspace (closing vchan connection). > > > > Specific message: > > > > [ 83.973377] ------------[ cut here ]------------ > > [ 83.975523] Interrupt for port 77, but apparently not enabled; per-user > > 00000000a0e9f1d1 > > Finally I think I have a fix (thanks to Demi for finding the problematic patch > through bisecting). > > Could you please try the attached patch? It is based on current upstream, but > I think it should apply to 6.7 or stable 6.6, too. > > > Juergen > From 9d673c37b2d0c9aa274c53f619c4e9e43a419f41 Mon Sep 17 00:00:00 2001 > From: Juergen Gross <jgross@xxxxxxxx> > To: linux-kernel@xxxxxxxxxxxxxxx > Cc: Juergen Gross <jgross@xxxxxxxx> > Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx> > Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx> > Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx > Date: Tue, 12 Mar 2024 13:52:24 +0100 > Subject: [PATCH] xen/evtchn: avoid WARN() when unbinding an event channel > > When unbinding a user event channel, the related handler might be > called a last time in case the kernel was built with > CONFIG_DEBUG_SHIRQ. This might cause a WARN() in the handler. > > Avoid that by adding an "unbinding" flag to struct user_event which > will short circuit the handler. > > Fixes: 9e90e58c11b7 ("xen: evtchn: Allow shared registration of IRQ handers") > Signed-off-by: Juergen Gross <jgross@xxxxxxxx> > --- > drivers/xen/evtchn.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c > index 59717628ca42..f6a2216c2c87 100644 > --- a/drivers/xen/evtchn.c > +++ b/drivers/xen/evtchn.c > @@ -85,6 +85,7 @@ struct user_evtchn { > struct per_user_data *user; > evtchn_port_t port; > bool enabled; > + bool unbinding; > }; > > static void evtchn_free_ring(evtchn_port_t *ring) > @@ -164,6 +165,10 @@ static irqreturn_t evtchn_interrupt(int irq, void *data) > struct per_user_data *u = evtchn->user; > unsigned int prod, cons; > > + /* Handler might be called when tearing down the IRQ. */ > + if (evtchn->unbinding) > + return IRQ_HANDLED; > + > WARN(!evtchn->enabled, > "Interrupt for port %u, but apparently not enabled; per-user %p\n", > evtchn->port, u); > @@ -421,6 +426,7 @@ static void evtchn_unbind_from_user(struct per_user_data > *u, > > BUG_ON(irq < 0); > > + evtchn->unbinding = true; > unbind_from_irqhandler(irq, evtchn); > > del_evtchn(u, evtchn); > -- > 2.35.3 That fixes the problem, thanks! Code looks good to me. Reported-by: Demi Marie Obenour <demi@xxxxxxxxxxxxxxxxxxxxxx> Tested-by: Demi Marie Obenour <demi@xxxxxxxxxxxxxxxxxxxxxx> -- Sincerely, Demi Marie Obenour (she/her/hers) Invisible Things Lab Attachment:
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