Rename symbols.h to vmalloc.h

[lttng-modules.git] / wrapper / vmalloc.h

diff --git a/wrapper/vmalloc.h b/wrapper/vmalloc.h
new file mode 100644 (file)
index 0000000..7d87855
--- /dev/null
+++ b/wrapper/vmalloc.h
@@ -0,0 +1,48 @@
+#ifndef _LTT_WRAPPER_VMALLOC_H
+#define _LTT_WRAPPER_VMALLOC_H
+
+/*
+ * Copyright (C) 2011 Mathieu Desnoyers (mathieu.desnoyers@efficios.com)
+ *
+ * wrapper around vmalloc_sync_all. Using KALLSYMS to get its address when
+ * available, else we need to have a kernel that exports this function to GPL
+ * modules.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#ifdef CONFIG_KALLSYMS
+
+#include <linux/kallsyms.h>
+
+static inline
+void wrapper_vmalloc_sync_all(void)
+{
+       void (*vmalloc_sync_all_sym)(void);
+
+       vmalloc_sync_all_sym = (void *) kallsyms_lookup_name("vmalloc_sync_all");
+       if (vmalloc_sync_all_sym) {
+               vmalloc_sync_all_sym();
+       } else {
+#ifdef CONFIG_X86
+               /*
+                * Only x86 needs vmalloc_sync_all to make sure LTTng does not
+                * trigger recursive page faults.
+                */
+               printk(KERN_WARNING "LTTng: vmalloc_sync_all symbol lookup failed.\n");
+               printk(KERN_WARNING "Page fault handler and NMI tracing might trigger faults.\n");
+#endif
+       }
+}
+#else
+
+#include <linux/vmalloc.h>
+
+static inline
+void wrapper_vmalloc_sync_all(void)
+{
+       return vmalloc_sync_all();
+}
+#endif
+
+#endif /* _LTT_WRAPPER_VMALLOC_H */