Module Name: src
Committed By: jdolecek
Date: Tue Aug 21 18:11:10 UTC 2018
Modified Files:
src/sys/arch/xen/xen: xbd_xenbus.c
Log Message:
avoid race condition between I/O submission in xbd_diskstart() and
interrupt handling in xbd_handler() - need to protect it with splbio()
fixes PR port-xen/53506 by Emmanuel Dreyfus, and likely also port-xen/53074
by Brad Spencer
To generate a diff of this commit:
cvs rdiff -u -r1.82 -r1.83 src/sys/arch/xen/xen/xbd_xenbus.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/xen/xen/xbd_xenbus.c
diff -u src/sys/arch/xen/xen/xbd_xenbus.c:1.82 src/sys/arch/xen/xen/xbd_xenbus.c:1.83
--- src/sys/arch/xen/xen/xbd_xenbus.c:1.82 Wed Aug 15 15:49:15 2018
+++ src/sys/arch/xen/xen/xbd_xenbus.c Tue Aug 21 18:11:10 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: xbd_xenbus.c,v 1.82 2018/08/15 15:49:15 jdolecek Exp $ */
+/* $NetBSD: xbd_xenbus.c,v 1.83 2018/08/21 18:11:10 jdolecek Exp $ */
/*
* Copyright (c) 2006 Manuel Bouyer.
@@ -50,7 +50,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xbd_xenbus.c,v 1.82 2018/08/15 15:49:15 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xbd_xenbus.c,v 1.83 2018/08/21 18:11:10 jdolecek Exp $");
#include "opt_xen.h"
@@ -932,6 +932,7 @@ xbd_diskstart(device_t self, struct buf
vaddr_t va;
int nsects, nbytes, seg;
int notify, error = 0;
+ int s;
DPRINTF(("xbd_diskstart(%p): b_bcount = %ld\n",
bp, (long)bp->b_bcount));
@@ -947,6 +948,8 @@ xbd_diskstart(device_t self, struct buf
goto err;
}
+ s = splbio(); /* XXX SMP */
+
if (__predict_false(
sc->sc_backend_status == BLKIF_STATE_SUSPENDED)) {
/* device is suspended, do not consume buffer */
@@ -1024,6 +1027,7 @@ out:
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&sc->sc_ring, notify);
if (notify)
hypervisor_notify_via_evtchn(sc->sc_evtchn);
+ splx(s); /* XXXSMP */
err:
return error;
}
