Re: x86/paravirt: Use a single ops structure
From: Marc Dionne
Date: Tue Oct 30 2018 - 09:33:56 EST
On Mon, Oct 29, 2018 at 11:25 AM Juergen Gross <jgross@xxxxxxxx> wrote:
> On 29/10/2018 13:58, Marc Dionne wrote:
> > On Tue, Oct 23, 2018 at 2:37 PM Linux Kernel Mailing List
> > <linux-kernel@xxxxxxxxxxxxxxx> wrote:
> >> Commit: 5c83511bdb9832c86be20fb86b783356e2f58062
> >> Parent: 27876f3882fdd4acb3d3614a0133ecdc777fc292
> >> Refname: refs/heads/master
> >> Web: https://git.kernel.org/torvalds/c/5c83511bdb9832c86be20fb86b783356e2f58062
> >> Author: Juergen Gross <jgross@xxxxxxxx>
> >> AuthorDate: Tue Aug 28 09:40:19 2018 +0200
> >> Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> >> CommitDate: Mon Sep 3 16:50:35 2018 +0200
> >> x86/paravirt: Use a single ops structure
> >> Instead of using six globally visible paravirt ops structures combine
> >> them in a single structure, keeping the original structures as
> >> sub-structures.
> >> This avoids the need to assemble struct paravirt_patch_template at
> >> runtime on the stack each time apply_paravirt() is being called (i.e.
> >> when loading a module).
> > The above commit replaces pv_lock_ops, which was EXPORT_SYMBOL, with
> > something that is part of pv_ops, which is EXPORT_SYMBOL_GPL. When
> > CONFIG_PARAVIRT_SPINLOCKS is set, this has the side effect of making
> > spin_lock() unusable by out of tree modules, which will likely be an
> > issue for many, if not most of them.
> Thanks for noticing!
> Sending a patch soon...
Thanks for the quick patch. Does this also need fixing for arm/arm64?
I can't easily verify but it seems like it would have the same issue.