staging: vchiq_debugfs: Fix NPD in vchiq_dump_state

The commit 42a2f66 ("staging: vc04_services: Move global g_state
to vchiq_state") falsely assumed that the debugfs entry vchiq/state
was created with vchiq_instance as data. This causes now a NULL
pointer derefence while trying to dump the vchiq state. So fix
this by passing vchiq_state as data, because this is the relevant
part here.

Fixes: 42a2f66 ("staging: vc04_services: Move global g_state to vchiq_state")
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Link: https://lore.kernel.org/r/20240524151542.19415-1-wahrenst@gmx.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c

@@ -1759,7 +1759,7 @@ static int vchiq_probe(struct platform_device *pdev)
 	if (err)
 		goto failed_platform_init;
 
-	vchiq_debugfs_init();
+	vchiq_debugfs_init(&mgmt->state);
 
 	dev_dbg(&pdev->dev, "arm: platform initialised - version %d (min %d)\n",
 		VCHIQ_VERSION, VCHIQ_VERSION_MIN);

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_debugfs.c

@@ -42,9 +42,9 @@ static int debugfs_trace_show(struct seq_file *f, void *offset)
 
 static int vchiq_dump_show(struct seq_file *f, void *offset)
 {
-	struct vchiq_instance *instance = f->private;
+	struct vchiq_state *state = f->private;
 
-	vchiq_dump_state(f, instance->state);
+	vchiq_dump_state(f, state);
 
 	return 0;
 }
@@ -121,12 +121,12 @@ void vchiq_debugfs_remove_instance(struct vchiq_instance *instance)
 	debugfs_remove_recursive(node->dentry);
 }
 
-void vchiq_debugfs_init(void)
+void vchiq_debugfs_init(struct vchiq_state *state)
 {
 	vchiq_dbg_dir = debugfs_create_dir("vchiq", NULL);
 	vchiq_dbg_clients = debugfs_create_dir("clients", vchiq_dbg_dir);
 
-	debugfs_create_file("state", S_IFREG | 0444, vchiq_dbg_dir, NULL,
+	debugfs_create_file("state", S_IFREG | 0444, vchiq_dbg_dir, state,
 			    &vchiq_dump_fops);
 }
 

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_debugfs.h

@@ -10,7 +10,7 @@ struct vchiq_debugfs_node {
 	struct dentry *dentry;
 };
 
-void vchiq_debugfs_init(void);
+void vchiq_debugfs_init(struct vchiq_state *state);
 
 void vchiq_debugfs_deinit(void);