From fd896e38e5df2c5b68c78eee2fc425c4dcd3b4dd Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 17 Nov 2022 09:26:41 +0000 Subject: [PATCH] net: fix napi_disable() logic error Dan reported a new warning after my recent patch: New smatch warnings: net/core/dev.c:6409 napi_disable() error: uninitialized symbol 'new'. Indeed, we must first wait for STATE_SCHED and STATE_NPSVC to be cleared, to make sure @new variable has been initialized properly. Fixes: 4ffa1d1c6842 ("net: adopt try_cmpxchg() in napi_{enable|disable}()") Reported-by: kernel test robot Reported-by: Dan Carpenter Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/dev.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index d0fb4af9a126..7627c475d991 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6399,9 +6399,9 @@ void napi_disable(struct napi_struct *n) val = READ_ONCE(n->state); do { - if (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) { + while (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) { usleep_range(20, 200); - continue; + val = READ_ONCE(n->state); } new = val | NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC;