We initialise the events_a and events_b variables with
tcp_splice_conn_epoll_events() function, then immediately copy the values
into ev_a.events and ev_b.events. We can't simply pass &ev_[ab].events to
tcp_splice_conn_epoll_events(), because struct epoll_event is packed,
leading to 'pointer may be unaligned' warnings if we attempt that.
We can, however, make tcp_splice_conn_epoll_events() take struct
epoll_event pointers rather than raw u32 pointers, avoiding the awkward
temporaries.
Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au>
---
tcp_splice.c | 24 +++++++++++-------------
1 file changed, 11 insertions(+), 13 deletions(-)
diff --git a/tcp_splice.c b/tcp_splice.c
index 439fc1d..3419207 100644
--- a/tcp_splice.c
+++ b/tcp_splice.c
@@ -95,25 +95,26 @@ static int tcp_sock_refill_ns(void *arg);
/**
* tcp_splice_conn_epoll_events() - epoll events masks for given state
* @events: Connection event flags
- * @a: Event mask for socket with accepted connection, set on return
- * @b: Event mask for connection target socket, set on return
+ * @a: Event for socket with accepted connection, set on return
+ * @b: Event for connection target socket, set on return
*/
static void tcp_splice_conn_epoll_events(uint16_t events,
- uint32_t *a, uint32_t *b)
+ struct epoll_event *a,
+ struct epoll_event *b)
{
- *a = *b = 0;
+ a->events = b->events = 0;
if (events & SPLICE_ESTABLISHED) {
if (!(events & B_FIN_SENT))
- *a = EPOLLIN | EPOLLRDHUP;
+ a->events = EPOLLIN | EPOLLRDHUP;
if (!(events & A_FIN_SENT))
- *b = EPOLLIN | EPOLLRDHUP;
+ b->events = EPOLLIN | EPOLLRDHUP;
} else if (events & SPLICE_CONNECT) {
- *b = EPOLLOUT;
+ b->events = EPOLLOUT;
}
- *a |= (events & A_OUT_WAIT) ? EPOLLOUT : 0;
- *b |= (events & B_OUT_WAIT) ? EPOLLOUT : 0;
+ a->events |= (events & A_OUT_WAIT) ? EPOLLOUT : 0;
+ a->events |= (events & B_OUT_WAIT) ? EPOLLOUT : 0;
}
/**
@@ -133,11 +134,8 @@ static int tcp_splice_epoll_ctl(const struct ctx *c,
.tcp.index = CONN_IDX(conn) };
struct epoll_event ev_a = { .data.u64 = ref_a.u64 };
struct epoll_event ev_b = { .data.u64 = ref_b.u64 };
- uint32_t events_a, events_b;
- tcp_splice_conn_epoll_events(conn->events, &events_a, &events_b);
- ev_a.events = events_a;
- ev_b.events = events_b;
+ tcp_splice_conn_epoll_events(conn->events, &ev_a, &ev_b);
if (epoll_ctl(c->epollfd, m, conn->a, &ev_a) ||
epoll_ctl(c->epollfd, m, conn->b, &ev_b)) {
--
2.41.0