x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted

The local "root" pointer is a temporary variable used during the device
search. Therefore, refcount related to the search iterators should be cleaned
up after the search is complete.

Use the __free() cleanup macro to ensure the refcount is decremented when the
temporary pointer goes out of scope.

Additionally, increment the refcount when caching a root pointer. This ensures
the in-use refcount is separate from the temporary search refcounting.

Finally, drop the redundant "root = NULL" before the second search loop. The
pci_get_class() iterator always decrements the refcount of its "from"
argument, so the first loop can only fall through with "root" already NULL.

Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")
Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com

1 files changed, 64 insertions, 0 deletions

diff --git a/net/sunrpc/xprtrdma/module.c b/net/sunrpc/xprtrdma/module.c
new file mode 100644
index 000000000..697f571d4
--- /dev/null
+++ b/net/sunrpc/xprtrdma/module.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * Copyright (c) 2015, 2017 Oracle.  All rights reserved.
+ */
+
+/* rpcrdma.ko module initialization
+ */
+
+#include <linux/types.h>
+#include <linux/compiler.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sunrpc/svc_rdma.h>
+#include <linux/sunrpc/rdma_rn.h>
+
+#include <asm/swab.h>
+
+#include "xprt_rdma.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/rpcrdma.h>
+
+MODULE_AUTHOR("Open Grid Computing and Network Appliance, Inc.");
+MODULE_DESCRIPTION("RPC/RDMA Transport");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("svcrdma");
+MODULE_ALIAS("xprtrdma");
+MODULE_ALIAS("rpcrdma6");
+
+static void __exit rpc_rdma_cleanup(void)
+{
+	xprt_rdma_cleanup();
+	svc_rdma_cleanup();
+	rpcrdma_ib_client_unregister();
+}
+
+static int __init rpc_rdma_init(void)
+{
+	int rc;
+
+	rc = rpcrdma_ib_client_register();
+	if (rc)
+		goto out_rc;
+
+	rc = svc_rdma_init();
+	if (rc)
+		goto out_ib_client;
+
+	rc = xprt_rdma_init();
+	if (rc)
+		goto out_svc_rdma;
+
+	return 0;
+
+out_svc_rdma:
+	svc_rdma_cleanup();
+out_ib_client:
+	rpcrdma_ib_client_unregister();
+out_rc:
+	return rc;
+}
+
+module_init(rpc_rdma_init);
+module_exit(rpc_rdma_cleanup);