xen/events: Cleanup find_virq() return codes

commit 08df2d7dd4ab2db8a172d824cda7872d5eca460a upstream.

rc is overwritten by the evtchn_status hypercall in each iteration, so
the return value will be whatever the last iteration is.  This could
incorrectly return success even if the event channel was not found.
Change to an explicit -ENOENT for an un-found virq and return 0 on a
successful match.

Fixes: 62cc5fc7b2e0 ("xen/pv-on-hvm kexec: rebind virqs to existing eventchannel ports")
Cc: stable@vger.kernel.org
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Message-ID: <20250828003604.8949-2-jason.andryuk@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 96b96516c9806c5bd1b7eb7b1290a38cd90c5492..c2e41d6cab9edb4fd2ce567d6f414f33251780d2 100644 (file)
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -1332,10 +1332,11 @@ static int find_virq(unsigned int virq, unsigned int cpu, evtchn_port_t *evtchn)
 {
        struct evtchn_status status;
        evtchn_port_t port;
-       int rc = -ENOENT;
 
        memset(&status, 0, sizeof(status));
        for (port = 0; port < xen_evtchn_max_channels(); port++) {
+               int rc;
+
                status.dom = DOMID_SELF;
                status.port = port;
                rc = HYPERVISOR_event_channel_op(EVTCHNOP_status, &status);
@@ -1345,10 +1346,10 @@ static int find_virq(unsigned int virq, unsigned int cpu, evtchn_port_t *evtchn)
                        continue;
                if (status.u.virq == virq && status.vcpu == xen_vcpu_nr(cpu)) {
                        *evtchn = port;
-                       break;
+                       return 0;
                }
        }
-       return rc;
+       return -ENOENT;
 }
 
 /**