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

[Ingo Molnar <mingo@elte.hu>]

* Mikael Pettersson <mikpe@it.uu.se> 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