Re: [PATCH v3] binfmt_elf: Dump smaller VMAs first in ELF cores

[Kees Cook <kees@kernel.org>]

On Sat, Aug 10, 2024 at 07:28:44AM -0500, Eric W. Biederman wrote:
> Brian Mak <makb@juniper.net> writes:
> 
> > Large cores may be truncated in some scenarios, such as with daemons
> > with stop timeouts that are not large enough or lack of disk space. This
> > impacts debuggability with large core dumps since critical information
> > necessary to form a usable backtrace, such as stacks and shared library
> > information, are omitted.
> >
> > We attempted to figure out which VMAs are needed to create a useful
> > backtrace, and it turned out to be a non-trivial problem. Instead, we
> > try simply sorting the VMAs by size, which has the intended effect.
> >
> > By sorting VMAs by dump size and dumping in that order, we have a
> > simple, yet effective heuristic.
> 
> To make finding the history easier I would include:
> v1: https://lkml.kernel.org/r/CB8195AE-518D-44C9-9841-B2694A5C4002@juniper.net
> v2: https://lkml.kernel.org/r/C21B229F-D1E6-4E44-B506-A5ED4019A9DE@juniper.net
> 
> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
> 
> As Kees has already picked this up this is quite possibly silly.
> But *shrug* that was when I was out.

I've updated the trailers. Thanks for the review!

-Kees

-- 
Kees Cook