debug: add notifier chain debugging, v2
- unbreak ia64 (and powerpc) where function pointers dont
point at code but at data (reported by Tony Luck)
[ mingo@elte.hu: various cleanups ]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/extable.c b/kernel/extable.c
index a26cb2e..adf0cc9 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -66,3 +66,19 @@
return 1;
return module_text_address(addr) != NULL;
}
+
+/*
+ * On some architectures (PPC64, IA64) function pointers
+ * are actually only tokens to some data that then holds the
+ * real function address. As a result, to find if a function
+ * pointer is part of the kernel text, we need to do some
+ * special dereferencing first.
+ */
+int func_ptr_is_kernel_text(void *ptr)
+{
+ unsigned long addr;
+ addr = (unsigned long) dereference_function_descriptor(ptr);
+ if (core_kernel_text(addr))
+ return 1;
+ return module_text_address(addr) != NULL;
+}