Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking

From: Jiri Kosina
Date: Mon May 02 2016 - 15:54:33 EST

On Mon, 2 May 2016, Andy Lutomirski wrote:

> FWIW, I just tried this:
> static bool is_entry_text(unsigned long addr)
> {
> return addr >= (unsigned long)__entry_text_start &&
> addr < (unsigned long)__entry_text_end;
> }
> it works. So the entry code is already annotated reasonably well :)
> I just hacked it up here:
> and it seems to work, at least for page faults. A better
> implementation would print out the entire contents of pt_regs so that
> people reading the stack trace will know the registers at the time of
> the exception, which might be helpful.

Sorry for being dense, but how do you distinguish here between a "real"
kernel entry, that pushes pt_regs, and any "non-entry" function call that
passes pt_regs around?

Jiri Kosina