On Thu, Apr 18, 2019 at 10:41:47AM +0200, Thomas Gleixner wrote: > +typedef bool (*stack_trace_consume_fn)(void *cookie, unsigned long addr, > + bool reliable); > +void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, > + struct task_struct *task, struct pt_regs *regs); > +int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry, void *cookie, > + struct task_struct *task); This bugs me a little; ideally the _reliable() thing would not exists. Thomas said that the existing __save_stack_trace_reliable() is different enough for the unification to be non-trivial, but maybe Josh can help out? >From what I can see the biggest significant differences are: - it looks at the regs sets on the stack and for FP bails early - bails for khreads and idle (after it does all the hard work!?!) The first (FP checking for exceptions) should probably be reflected in consume_fn(.reliable) anyway -- although that would mean a lot of extra '?' entries where there are none today. And the second (KTHREAD/IDLE) is something that the generic code can easily do before calling into the arch unwinder. Hmm?
