Messages in this thread | | | From | Linus Torvalds <> | Date | Fri, 5 Jan 2018 19:09:01 -0800 | Subject | Re: [PATCH 06/18] x86, barrier: stop speculation for failed access_ok |
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On Fri, Jan 5, 2018 at 6:52 PM, Linus Torvalds <torvalds@linux-foundation.org> wrote: > > The fact is, we have to stop speculating when access_ok() does *not* > fail - because that's when we'll actually do the access. And it's that > access that needs to be non-speculative.
I also suspect we should probably do this entirely differently.
Maybe the whole lfence can be part of uaccess_begin() instead (ie currently 'stac()'). That would fit the existing structure better, I think. And it would avoid any confusion about the whole "when to stop speculation".
Linus
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