Re: [patch] add /proc/pid/stack to dump task's stack trace

From: Ingo Molnar
Date: Tue Nov 11 2008 - 09:20:03 EST



* Mikael Pettersson <mikpe@xxxxxxxx> wrote:

> Ingo Molnar writes:
> > > > # cat /proc/18579/stack
> > > > [<ffffffffffffffff>] 0xffffffffffffffff
> > >
> > > so this file provides view of _kernel_ stack only?
> > > shouldn't it be named kernel-stack then?
> >
> > it prints the kernel stack right now, but i'd not restrict it to
> > the kernel stack conceptually: i think we could eventually expand
> > it to print the user-space portion of the stack as well. (in the
> > case when user-space is built with frame pointers) We've got code
> > for that in the kernel already. It would be an easy one-stop-shop
> > for full-range.
>
> That would be quite fragile given the fact that user-space only has
> to follow standard ABIs at specific points like calls to standard
> library functions. In between, anything can, and does, happen.

it's not fragile to robustly walk the userspace stack. The result
might not always be meaningful of course.

Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/