[LAD] Realtime threads and security

[Paul Davis]

On Thu, Feb 17, 2011 at 3:40 PM, Olivier Guilyardi <list at samalyse.com> wrote:

> Or is there some other ways to achieve this? Some kernel patch maybe?

in earlier versions of 2.6, the kernel patch to allow SCHED_FIFO for
everyone was incredibly simple. i recall kjetil posting a couple of
lines, at most.

whether this a security risk depends on which other parts of the
kernel android uses. on regular linux, its no longer possible for any
process to steal all the CPU time. there are files in the /proc/sys
filesystem that control the amount available.

note that patching the kernel in this way means that any process by
any user can get SCHED_FIFO so its hardly clear that this is actually
any better than using rlimits from a security perspective.