[lldb-dev] ASLR disabled by default - thoughts?

[Todd Fiala]

> Is ASLR per-launch / per-process on other platforms?

Linux allows you to set it per process, and based on previous comments,
MacOSX does as well (there's a posix_spawn flag for it on that platform).
 You can disable it on Linux at the kernel level, but that's not how we
want to use it in this scenario.

You don't have a way to disable it just for a process on Windows?

-Todd


On Fri, Aug 15, 2014 at 9:33 AM, Greg Clayton <gclayton at apple.com> wrote:

> Yes it should be disabled by default for all systems. It is this was on
> MacOSX by default. The linux plug-in will need to be fixed.
>
> > On Aug 14, 2014, at 9:41 AM, Todd Fiala <todd.fiala at gmail.com> wrote:
> >
> > [I'm not seeing this show up in the archives two hours after I posted it
> from my google account, so I'm sending it from my gmail account.  Pardon if
> this shows up again in the next 24 hours from my @google.com account...]
> >
> > ---------- Forwarded message ----------
> > From: Todd Fiala <tfiala at google.com>
> > Date: Thu, Aug 14, 2014 at 7:29 AM
> > Subject: ASLR disabled by default - thoughts?
> > To: "lldb-dev at cs.uiuc.edu" <lldb-dev at cs.uiuc.edu>
> >
> >
> > Hey all,
> >
> > Regarding this bug:
> > http://llvm.org/bugs/show_bug.cgi?id=20658
> >
> > We've been discussing the idea of having ASLR disabled by default when
> launching processes within lldb.  Currently it looks like the default
> behavior is to have it enabled, and require explicitly disabling to get
> that behavior for the process.
> >
> > It seems like it might make more sense to have it disabled by default -
> that way code references would likely be static across debugger runs, which
> seems to be more what we want when tracking down issues across code runs.
> >
> > Any thoughts on this?
> >
> > The counterargument I could make for changing it would be (aside from
> legacy compatibility issues perhaps on the MacOSX/iOS side) - taking the
> exe out of its native state on the OS.  If a bug is ASLR sensitive, the
> user might miss it.  And so behavior in the debugger could differ from the
> exe in its native state.  Not sure how relevant that is for the majority of
> usages, though.
> >
> > I'll be fixing the fact that Linux is ignoring this altogether.  But
> while I'm in there, I could flip the default if we wanted to do it.  If not
> globally, we'd probably pursue defaulting it on Linux (and Ed seems to like
> it for FreeBSD as well, so maybe for not Apple in that case?)
> > --
> > Todd Fiala |   Software Engineer |     tfiala at google.com |
> 650-943-3180
> > --
> > -Todd
> > _______________________________________________
> > lldb-dev mailing list
> > lldb-dev at cs.uiuc.edu
> > http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
>
> _______________________________________________
> lldb-dev mailing list
> lldb-dev at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
>



-- 
Todd Fiala | Software Engineer | tfiala at google.com | 650-943-3180
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/lldb-dev/attachments/20140815/15d8e54b/attachment.html>