Re: [PATCH v6 7/7] mseal, system mappings: update mseal.rst

[Jeff Xu]

On Mon, Feb 24, 2025 at 12:26 PM Liam R. Howlett
<Liam.Howlett@xxxxxxxxxx> wrote:
>
> * jeffxu@xxxxxxxxxxxx <jeffxu@xxxxxxxxxxxx> [250224 12:45]:
> > From: Jeff Xu <jeffxu@xxxxxxxxxxxx>
> >
> > Update memory sealing documentation to include details about system
> > mappings.
> >
> > Signed-off-by: Jeff Xu <jeffxu@xxxxxxxxxxxx>
> > ---
> >  Documentation/userspace-api/mseal.rst | 7 +++++++
> >  1 file changed, 7 insertions(+)
> >
> > diff --git a/Documentation/userspace-api/mseal.rst b/Documentation/userspace-api/mseal.rst
> > index 41102f74c5e2..10147281bf2d 100644
> > --- a/Documentation/userspace-api/mseal.rst
> > +++ b/Documentation/userspace-api/mseal.rst
> > @@ -130,6 +130,13 @@ Use cases
> >
> >  - Chrome browser: protect some security sensitive data structures.
>
> Did you mean to drop this line?
>
Ah, thank you for catching that.

-Jeff


> >
> > +- System mappings:
> > +  If supported by an architecture (via CONFIG_ARCH_HAS_MSEAL_SYSTEM_MAPPINGS),
> > +  the CONFIG_MSEAL_SYSTEM_MAPPINGS seals system mappings, e.g. vdso, vvar,
> > +  uprobes, sigpage, vectors, etc. CHECKPOINT_RESTORE, UML, gVisor, rr are
> > +  known to relocate or unmap system mapping, therefore this config can't be
> > +  enabled universally.
> > +
> >  When not to use mseal
> >  =====================
> >  Applications can apply sealing to any virtual memory region from userspace,
> > --
> > 2.48.1.601.g30ceb7b040-goog
> >