Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH 03/35] x86/entry/32: Load task stack from x86_tss.sp1 in SYSENTER handler | Date | Thu, 19 Apr 2018 09:01:12 +0000 |
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From: Andi Kleen > Sent: 19 April 2018 01:39 > > On Wed, Apr 18, 2018 at 05:02:02PM -0700, Linus Torvalds wrote: > > On Wed, Apr 18, 2018 at 4:26 PM, Andi Kleen <ak@linux.intel.com> wrote: > > > > > > Seems like a hack. Why can't that be stored in a per cpu variable? > > > > It *is* a percpu variable - the whole x86_tss structure is percpu. > > > > I guess it could be a different (separate) percpu variable, but might > > as well use the space we already have allocated. > > Would be better/cleaner to use a separate variable instead of reusing > x86 structures like this. Who knows what subtle side effects that > may have eventually. > > It will be also easier to understand in the code.
You could (probably) use an unnamed union in the x86_tss structure so that it is more obvious that the two variables share a location.
David
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