The origin of the story is from here http://pythonsweetness.tumblr.com/post/169166980422/the-mysterious-case-of-the-linux-page-table
L. ------ "The antidote to apocalypticism is *apocalyptic civics*. Apocalyptic civics is the insistence that we cannot ignore the truth, nor should we panic about it. It is a shared consciousness that our institutions have failed and our ecosystem is collapsing, yet we are still here — and we are creative agents who can shape our destinies. Apocalyptic civics is the conviction that the only way out is through, and the only way through is together. " *Greg Bloom* @greggish https://twitter.com/greggish/status/873177525903609857 On 3 January 2018 at 19:46, John Hearns via Beowulf <beowulf@beowulf.org> wrote: > 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 >> > > > _______________________________________________ > 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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