From: Trond Myklebust trondmy@gmail.com
mainline inclusion from mainline-5.1-rc1 commit 1602a7b7d33741d0490682e620bb29e96ad684d7 category: bugfix bugzilla: 51818 CVE: NA
------------------------------------------------- Use READ_ONCE() to tell the compiler to not optimse away the read of xprt->xpt_flags in svc_xprt_release_slot().
Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: J. Bruce Fields bfields@redhat.com Signed-off-by: Zhang Changzhong zhangchangzhong@huawei.com Reviewed-by: Yue Haibing yuehaibing@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- net/sunrpc/svc_xprt.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index 0f89fc6c92e2f..0ab649e028617 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -373,9 +373,13 @@ static void svc_xprt_release_slot(struct svc_rqst *rqstp)
static bool svc_xprt_has_something_to_do(struct svc_xprt *xprt) { - if (xprt->xpt_flags & ((1<<XPT_CONN)|(1<<XPT_CLOSE))) + unsigned long xpt_flags; + + xpt_flags = READ_ONCE(xprt->xpt_flags); + + if (xpt_flags & (BIT(XPT_CONN) | BIT(XPT_CLOSE))) return true; - if (xprt->xpt_flags & ((1<<XPT_DATA)|(1<<XPT_DEFERRED))) { + if (xpt_flags & (BIT(XPT_DATA) | BIT(XPT_DEFERRED))) { if (xprt->xpt_ops->xpo_has_wspace(xprt) && svc_xprt_slots_in_range(xprt)) return true;