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

[Jiri Kosina]

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:
> 
> https://git.kernel.org/cgit/linux/kernel/git/luto/linux.git/commit/?h=stack&id=085eacfe0edfc18768e48340084415dba9a6bd21
> 
> 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
SUSE Labs