== Why does my backtrace contain a mixture of function call chains? == So your kernel oopsed and gave you a stack trace that mostly makes sense, but has a function or two on it that do not get called at all in this code path? This is a normal occurence in Linux. Unless `CONFIG_FRAME_POINTER` (or later, `CONFIG_UNWINDER_FRAME_POINTER` is enabled, the function `print_context_stack()` simply walks the whole stack and looks for any value that might be the address of a function in the kernel. It has no way of knowing whether that address is a stack frame return address from the current code path, a left-over return address from a previous code path or just a random value that was left on the stack. If you want to always get reliable stack traces when an oops happens, make sure you enable `CONFIG_FRAME_POINTER` or `CONFIG_UNWINDER_FRAME_POINTER`, as well as `CONFIG_STACKTRACE`, `CONFIG_UNWIND_INFO` and `CONFIG_STACK_UNWIND`. For x86_64, `CONFIG_UNWINDER_ORC` is also a reliable stack trace dumper. With these configuration options switched on, the kernel knows exactly which addresses are part of the current call chain, and which are not. == How do I manually get a stack trace? == You can manually try to create the stack trace from an oops message or from the stack dump of a task. See the [[http://kernelnewbies.org/ABI|ABI]] page for details on the stack convention for your architecture. ---- [[CategoryFAQ]]