Messages in this thread |  | | Date | Fri, 24 Nov 2017 14:04:45 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH 22/43] x86/mm/kaiser: Prepare assembly for entry/exit CR3 switching |
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On Fri, 24 Nov 2017, Peter Zijlstra wrote:
> On Fri, Nov 24, 2017 at 01:17:06PM +0100, Ingo Molnar wrote: > > > > * Peter Zijlstra <peterz@infradead.org> wrote: > > > > > On Fri, Nov 24, 2017 at 10:14:27AM +0100, Ingo Molnar wrote: > > > > @@ -1343,9 +1373,10 @@ ENTRY(error_entry) > > > > > > > > .Lerror_bad_iret: > > > > /* > > > > + * We came from an IRET to user mode, so we have user > > > > + * gsbase and CR3. Switch to kernel gsbase and CR3: > > > > */ > > > > + SWITCH_TO_KERNEL_CR3 scratch_reg=%rax > > > > SWAPGS > > > > > > > > /* > > > > > > The Changelog states SWAPGS must be done before, yet the code does > > > after. > > > > Yes, so this is the SWAPGS that is done before we go back to user-space. > > The comment there clearly states we have user gs and we need to switch > to kernel gs. The Changelog states we should switch gs before cr3. > > So either the comment or the code needs fixing.
The code :)
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