[PATCH 5.4 03/90] sunrpc: check that domain table is empty at module unload.

From: Greg Kroah-Hartman
Date: Mon Aug 03 2020 - 08:45:01 EST


[ Upstream commit f45db2b909c7e76f35850e78f017221f30282b8e ]

The domain table should be empty at module unload. If it isn't there is
a bug somewhere. So check and report.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=206651
Signed-off-by: NeilBrown <neilb@xxxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/sunrpc/sunrpc.h | 1 +
net/sunrpc/sunrpc_syms.c | 2 ++
net/sunrpc/svcauth.c | 27 +++++++++++++++++++++++++++
3 files changed, 30 insertions(+)

diff --git a/net/sunrpc/sunrpc.h b/net/sunrpc/sunrpc.h
index c9bacb3c930fa..82035fa65b8f9 100644
--- a/net/sunrpc/sunrpc.h
+++ b/net/sunrpc/sunrpc.h
@@ -56,4 +56,5 @@ int svc_send_common(struct socket *sock, struct xdr_buf *xdr,

int rpc_clients_notifier_register(void);
void rpc_clients_notifier_unregister(void);
+void auth_domain_cleanup(void);
#endif /* _NET_SUNRPC_SUNRPC_H */
diff --git a/net/sunrpc/sunrpc_syms.c b/net/sunrpc/sunrpc_syms.c
index f9edaa9174a43..236fadc4a4399 100644
--- a/net/sunrpc/sunrpc_syms.c
+++ b/net/sunrpc/sunrpc_syms.c
@@ -23,6 +23,7 @@
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <linux/sunrpc/xprtsock.h>

+#include "sunrpc.h"
#include "netns.h"

unsigned int sunrpc_net_id;
@@ -131,6 +132,7 @@ cleanup_sunrpc(void)
unregister_rpc_pipefs();
rpc_destroy_mempool();
unregister_pernet_subsys(&sunrpc_net_ops);
+ auth_domain_cleanup();
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
rpc_unregister_sysctl();
#endif
diff --git a/net/sunrpc/svcauth.c b/net/sunrpc/svcauth.c
index 550b214cb0015..998b196b61767 100644
--- a/net/sunrpc/svcauth.c
+++ b/net/sunrpc/svcauth.c
@@ -19,6 +19,10 @@
#include <linux/err.h>
#include <linux/hash.h>

+#include <trace/events/sunrpc.h>
+
+#include "sunrpc.h"
+
#define RPCDBG_FACILITY RPCDBG_AUTH


@@ -203,3 +207,26 @@ struct auth_domain *auth_domain_find(char *name)
return NULL;
}
EXPORT_SYMBOL_GPL(auth_domain_find);
+
+/**
+ * auth_domain_cleanup - check that the auth_domain table is empty
+ *
+ * On module unload the auth_domain_table must be empty. To make it
+ * easier to catch bugs which don't clean up domains properly, we
+ * warn if anything remains in the table at cleanup time.
+ *
+ * Note that we cannot proactively remove the domains at this stage.
+ * The ->release() function might be in a module that has already been
+ * unloaded.
+ */
+
+void auth_domain_cleanup(void)
+{
+ int h;
+ struct auth_domain *hp;
+
+ for (h = 0; h < DN_HASHMAX; h++)
+ hlist_for_each_entry(hp, &auth_domain_table[h], hash)
+ pr_warn("svc: domain %s still present at module unload.\n",
+ hp->name);
+}
--
2.25.1