Merge: core: stable backport from upstream form 9.8 phase 2

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/7455

JIRA: https://issues.redhat.com/browse/RHEL-115645

A critical fix for core networking.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Approved-by: Florian Westphal <fwestpha@redhat.com>
Approved-by: Hangbin Liu <haliu@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: CKI GitLab Kmaint Pipeline Bot <26919896-cki-kmaint-pipeline-bot@users.noreply.gitlab.com>

Author: CKI KWF Bot

net/core/page_pool.c

@@ -145,9 +145,9 @@ u64 *page_pool_ethtool_stats_get(u64 *data, const void *stats)
 EXPORT_SYMBOL(page_pool_ethtool_stats_get);
 
 #else
-#define alloc_stat_inc(pool, __stat)
-#define recycle_stat_inc(pool, __stat)
-#define recycle_stat_add(pool, __stat, val)
+#define alloc_stat_inc(...)	do { } while (0)
+#define recycle_stat_inc(...)	do { } while (0)
+#define recycle_stat_add(...)	do { } while (0)
 #endif
 
 static bool page_pool_producer_lock(struct page_pool *pool)
@@ -679,19 +679,16 @@ void page_pool_return_page(struct page_pool *pool, struct page *page)
 
 static bool page_pool_recycle_in_ring(struct page_pool *pool, struct page *page)
 {
-	int ret;
-	/* BH protection not needed if current is softirq */
-	if (in_softirq())
-		ret = ptr_ring_produce(&pool->ring, page);
-	else
-		ret = ptr_ring_produce_bh(&pool->ring, page);
+	bool in_softirq, ret;
 
-	if (!ret) {
+	/* BH protection not needed if current is softirq */
+	in_softirq = page_pool_producer_lock(pool);
+	ret = !__ptr_ring_produce(&pool->ring, page);
+	if (ret)
 		recycle_stat_inc(pool, ring);
-		return true;
-	}
+	page_pool_producer_unlock(pool, in_softirq);
 
-	return false;
+	return ret;
 }
 
 /* Only allow direct recycling in special circumstances, into the
@@ -1023,10 +1020,14 @@ static void page_pool_scrub(struct page_pool *pool)
 
 static int page_pool_release(struct page_pool *pool)
 {
+	bool in_softirq;
 	int inflight;
 
 	page_pool_scrub(pool);
 	inflight = page_pool_inflight(pool, true);
+	/* Acquire producer lock to make sure producers have exited. */
+	in_softirq = page_pool_producer_lock(pool);
+	page_pool_producer_unlock(pool, in_softirq);
 	if (!inflight)
 		__page_pool_destroy(pool);