On Wed, Feb 14, 2018 at 11:48:38AM -0800, Kees Cook wrote: > On Wed, Feb 14, 2018 at 11:06 AM, Laura Abbott <labbott@xxxxxxxxxx> wrote: > > fixed. Modules yes are not fully protected. The conclusion from past > > experience has been that we cannot safely break down larger page sizes > > at runtime like x86 does. We could theoretically > > add support for fixing up the alias if PAGE_POISONING is enabled but > > I don't know who would actually use that in production. Performance > > is very poor at that point. > > XPFO forces 4K pages on the physmap[1] for similar reasons. I have no > doubt about performance changes, but I'd be curious to see real > numbers. Did anyone do benchmarks on just the huge/4K change? (Without > also the XPFO overhead?) > > If this, XPFO, and PAGE_POISONING all need it, I think we have to > start a closer investigation. :) I haven't but it shouldn't be too hard. What benchmarks are you thinking? Tycho -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
