diff options
| author | Juergen Gross <jgross@suse.com> | 2024-03-13 08:14:08 +0100 |
|---|---|---|
| committer | Juergen Gross <jgross@suse.com> | 2024-03-17 18:57:11 +0100 |
| commit | 51c23bd691c0f1fb95b29731c356c6fd69925d17 (patch) | |
| tree | 8303d3b567bd0d502a80ed8b1c72b1c91d584fee | |
| parent | x86/xen: attempt to inflate the memory balloon on PVH (diff) | |
| download | linux-51c23bd691c0f1fb95b29731c356c6fd69925d17.tar.xz linux-51c23bd691c0f1fb95b29731c356c6fd69925d17.zip | |
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")
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Tested-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Link: https://lore.kernel.org/r/20240313071409.25913-2-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
| -rw-r--r-- | drivers/xen/evtchn.c | 6 |
1 files changed, 6 insertions, 0 deletions
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); |