blob: ecf2cf4ecfaaff1d5329dbfae8f127d136e4eb3a [file] [log] [blame]
From 25b6596ba04f28ae64df229eb294246695e73c2b Mon Sep 17 00:00:00 2001
From: Dongli Zhang <dongli.zhang@oracle.com>
Date: Tue, 3 Mar 2020 14:14:23 -0800
Subject: [PATCH] xenbus: req->err should be updated before req->state
commit 8130b9d5b5abf26f9927b487c15319a187775f34 upstream.
This patch adds the barrier to guarantee that req->err is always updated
before req->state.
Otherwise, read_reply() would not return ERR_PTR(req->err) but
req->body, when process_writes()->xb_write() is failed.
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Link: https://lore.kernel.org/r/20200303221423.21962-2-dongli.zhang@oracle.com
Reviewed-by: Julien Grall <jgrall@amazon.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/drivers/xen/xenbus/xenbus_comms.c b/drivers/xen/xenbus/xenbus_comms.c
index 852ed161fc2a..eb5151fc8efa 100644
--- a/drivers/xen/xenbus/xenbus_comms.c
+++ b/drivers/xen/xenbus/xenbus_comms.c
@@ -397,6 +397,8 @@ static int process_writes(void)
if (state.req->state == xb_req_state_aborted)
kfree(state.req);
else {
+ /* write err, then update state */
+ virt_wmb();
state.req->state = xb_req_state_got_reply;
wake_up(&state.req->wq);
}
--
2.7.4