Subject: RE: [PATCH v5 2/2] xen/x86: Livepatch: support patching CET-
enhanced functions
Hi Bjoern,
-Original Message-
From: Xen-devel On Behalf Of
Ross Lagerwall
Sent: 2022年3月10日 1:12
To: Bjoern Doebel ; xen-devel@lists.xenproject.org
Cc: Michael Kurth ; Martin Pohlack
; Roger Pau Monne
t;>> Sent: 2022年3月10日 1:12
>>> To: Bjoern Doebel ; xen-devel@lists.xenproject.org
>>> Cc: Michael Kurth ; Martin Pohlack
>>> ; Roger Pau Monne ;
>>> Andrew Cooper ; Konrad Rzeszutek Wilk
>>>
>>> Subject: Re: [PATCH v5 2/2] xen/x86: Livepatch
bel ; xen-devel@lists.xenproject.org
> > Cc: Michael Kurth ; Martin Pohlack
> > ; Roger Pau Monne ;
> > Andrew Cooper ; Konrad Rzeszutek Wilk
> >
> > Subject: Re: [PATCH v5 2/2] xen/x86: Livepatch: support patching CET-
> > enhanced functions
> >
> > >
nne ;
> Andrew Cooper ; Bjoern Doebel
> ; Konrad Rzeszutek Wilk ;
> Ross Lagerwall
> > Subject: [PATCH v5 2/2] xen/x86: Livepatch: support patching CET-
> enhanced functions
> >
> > Xen enabled CET for supporting architectures. The control flow aspect of
>
> From: Bjoern Doebel
> Sent: Wednesday, March 9, 2022 2:53 PM
> To: xen-devel@lists.xenproject.org
> Cc: Michael Kurth ; Martin Pohlack ;
> Roger Pau Monne ; Andrew Cooper
> ; Bjoern Doebel ; Konrad
> Rzeszutek Wilk ; Ross Lagerwall
>
> Subject: [PATCH v5 2/2]
On 09.03.2022 15:53, Bjoern Doebel wrote:
> Changes since r1:
> * use sizeof_field() to avoid unused variable warning
> * make metadata variable const in arch_livepatch_revert
> * rebase on top and make use of Andrew Cooper's was_endbr64() patch
> * use padding byte to store offset rather than
Xen enabled CET for supporting architectures. The control flow aspect of
CET expects functions that can be called indirectly (i.e., via function
pointers) to start with an ENDBR64 instruction. Otherwise a control flow
exception is raised.
This expectation breaks livepatching flows because we
