io_napi_entry timeout value can be updated while accessed from the poll
functions.
Its concurrent accesses are wrapped with READ_ONCE()/WRITE_ONCE() macros
to avoid incorrect compiler optimizations.
Signed-off-by: Olivier Langlois <olivier@xxxxxxxxxxxxxx>
---
io_uring/napi.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/io_uring/napi.c b/io_uring/napi.c
index d0cf694d0172..dda2e083fb5d 100644
--- a/io_uring/napi.c
+++ b/io_uring/napi.c
@@ -60,7 +60,7 @@ void __io_napi_add(struct io_ring_ctx *ctx, struct socket *sock)
rcu_read_lock();
e = io_napi_hash_find(hash_list, napi_id);
if (e) {
- e->timeout = jiffies + NAPI_TIMEOUT;
+ WRITE_ONCE(e->timeout, jiffies + NAPI_TIMEOUT);
rcu_read_unlock();
return;
}
@@ -92,7 +92,7 @@ static void __io_napi_remove_stale(struct io_ring_ctx *ctx)
spin_lock(&ctx->napi_lock);
hash_for_each(ctx->napi_ht, i, e, node) {
- if (time_after(jiffies, e->timeout)) {
+ if (time_after(jiffies, READ_ONCE(e->timeout))) {
list_del(&e->list);
hash_del_rcu(&e->node);
kfree_rcu(e, rcu);
@@ -150,7 +150,7 @@ static bool __io_napi_do_busy_loop(struct io_ring_ctx *ctx,
napi_busy_loop_rcu(e->napi_id, loop_end, loop_end_arg,
ctx->napi_prefer_busy_poll, BUSY_POLL_BUDGET);
- if (time_after(jiffies, e->timeout))
+ if (time_after(jiffies, READ_ONCE(e->timeout)))
is_stale = true;
}
--
2.47.0
