Messages in this thread | | | Date | Mon, 25 Jun 2018 11:22:29 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v12 01/11] x86: text_poke() may access uninitialized struct pages |
| |
On Mon, Jun 25, 2018 at 11:18:02AM +0200, Thomas Gleixner wrote: > On Mon, 25 Jun 2018, Peter Zijlstra wrote: > > On Mon, Jun 25, 2018 at 10:39:24AM +0200, Thomas Gleixner wrote: > > > On Mon, 25 Jun 2018, Peter Zijlstra wrote: > > > > I'm not entirely sure this is right.. Because not only do we need the > > > > whole fixmap stuff working, we also need #DB and the IPI handlers set-up > > > > and working. > > > > > > IPI? That's early UP boot why would you need an IPI? > > > > Because the way this is called is from __jump_label_transform() -> > > text_poke_bp() -> text_poke() -> text_poke_early(). > > > > And if you look at text_poke_bp(), you'll note it relies on #DB and > > on_each_cpu() IPIs. > > on_each_cpu() resolves to a direct call on the current CPU and as there is > no other CPU it does not matter. #DB might be a different story, haven't > looked yet.
It _should_ all work.. but scary, who knows where this early stuff ends up being used.
| |