On Mon, 8 Apr 2019, Andy Lutomirski wrote: > On Sun, Apr 7, 2019 at 11:46 PM Thomas Gleixner <t...@linutronix.de> wrote: > > > > On Sun, 7 Apr 2019, Andy Lutomirski wrote: > > > On Sun, Apr 7, 2019 at 3:44 PM Thomas Gleixner <t...@linutronix.de> wrote: > > > > Actually we have: save_stack_trace() > > > > > > > > > > Like I did here: > > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git/log/?h=WIP.x86/stackguards > > > > Kinda, but what that code wants is to skip any entry before 'caller'. So we > > either add something like save_stack_trace_from() which is trivial on x86 > > because unwind_start() already has an argument to hand in the start of > > stack or we filter out the entries up to 'caller' in that code. > > > > > Whoops! > > I could add a save_stack_trace_from() or I could add a "caller" > argument to struct stack_trace. Any preference as to which looks > better? The latter seems a little nicer to me.
The whole interface with struct stack_trace sucks. Why is skip and max entries in that struct and not an argument? I went through all the call sites and it just makes me shudder. That terminate trace with ULONG_MAX is another horrible hack which is then undone on several callsites again. Before we add more hacky stuff to it, lets cleanup that whole mess first. Thanks, tglx