[lkml]   [2009]   [May]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 2/2] perf_counter: optimize context switch between identical inherited contexts
Peter Zijlstra writes:

> Suppose someone writes a malicious proglet that inherits the counters,
> puts the child to sleep, does 2^32 mods on the counter set, and then
> wakes up the child.
> Would that merely corrupt the results, or make the kernel explode?

You'd have to do something like create some counters on yourself,
fork, do the 2^32 counter creations and deletions, then do another
fork. All that would happen is that some of the counters would count
on one of the child processes when they should be counting on the

But it would be easy and cheap to make the generation count be 64
bits, and then it won't overflow in my lifetime at least, and after
that I don't care. :) So I agree with Ingo that we should just do


 \ /
  Last update: 2009-05-22 11:59    [W:0.145 / U:4.160 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site