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

Jiri Kosina
2016-05-02T19:54:30Z

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