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Miller" , Eric Dumazet Subject: [PATCH net] eventpoll: Annotate data-race of busy_poll_usecs Date: Tue, 6 Aug 2024 12:33:01 +0000 Message-Id: <20240806123301.167557-1-jdamato@fastly.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Martin Karsten A struct eventpoll's busy_poll_usecs field can be modified via a user ioctl at any time. All reads of this field should be annotated with READ_ONCE. Fixes: 85455c795c07 ("eventpoll: support busy poll per epoll instance") Cc: stable@vger.kernel.org Signed-off-by: Martin Karsten Reviewed-by: Joe Damato --- fs/eventpoll.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index f53ca4f7fced..6d0e2f547ae7 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -420,7 +420,7 @@ static bool busy_loop_ep_timeout(unsigned long start_ti= me, =20 static bool ep_busy_loop_on(struct eventpoll *ep) { - return !!ep->busy_poll_usecs || net_busy_loop_on(); + return !!READ_ONCE(ep->busy_poll_usecs) || net_busy_loop_on(); } =20 static bool ep_busy_loop_end(void *p, unsigned long start_time) --=20 2.25.1