Re: [PATCH 09/12] x86/process: Pin the target stack in get_wchan()

From: Tycho Andersen
Date: Mon Sep 26 2016 - 01:11:03 EST

On Fri, Sep 23, 2016 at 08:34:43PM +0200, Jann Horn wrote:
> On Fri, Sep 23, 2016 at 11:28:26AM -0700, Kees Cook wrote:
> > Does CRIU use this? I wouldn't expect so, since they're using ptrace,
> > IIUC, to freeze/restore.
> As far as I can tell:
> parse_pid_stat() parses them into a struct proc_pid_stat as "esp" and "eip",
> but those struct members are never used (like, probably, most other members
> of that struct).

Yes, that's my reading of it too.

> child_opened_proc.c just opens /proc/%d/stat and then closes it again
> immediately.

This is just a test for ordering of things that are restored, and it
could use any file in /proc, stat was just convenient.

> So in summary: I don't think so.

Yep, agreed.