| Message ID | 20200303221423.21962-2-dongli.zhang@oracle.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | c5f13b8229ee4a3032080cab880cd2f40b3c213f |
| Headers | show |
| Series | [v3,1/2] xenbus: req->body should be updated before req->state | expand |
Hi, On 03/03/2020 22:14, Dongli Zhang wrote: > 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> Reviewed-by: Julien Grall <jgrall@amazon.com> Cheers, --- Julien Grall
On 3/3/20 5:14 PM, Dongli Zhang wrote: > 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> Applied to for-linus-5.6b. -boris
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); }
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> --- drivers/xen/xenbus/xenbus_comms.c | 2 ++ 1 file changed, 2 insertions(+)