Thanks Chris. In the past there have been Intel CPU 'bugs' trumpeted, but generally these are fixed with a microcode update. This looks different, as it is a fundamental part of the chips architecture. However the Register article says: "It allows normal user programs – to discern to some extent the layout or contents of protected kernel memory areas"
I guess the phrase "to some extent" is the vital one here. Are there any security exploits which use this information? I guess it is inevitable that one will be engineered now that this is known about. The question I am really asking is should we worry about this for real world systems. And I guess tha answer is that if the kernel developers are worried enough then yes we should be too. Comments please. On 3 January 2018 at 06:56, Greg Lindahl <lind...@pbm.com> wrote: > On Wed, Jan 03, 2018 at 02:46:07PM +1100, Christopher Samuel wrote: > > > There appears to be no microcode fix possible and the kernel fix will > > incur a significant performance penalty, people are talking about in the > > range of 5%-30% depending on the generation of the CPU. :-( > > The performance hit (at least for the current patches) is related to > system calls, which HPC programs using networking gear like OmniPath > or Infiniband don't do much of. > > -- greg > > > _______________________________________________ > Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing > To change your subscription (digest mode or unsubscribe) visit > http://www.beowulf.org/mailman/listinfo/beowulf >
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