Re: [PATCH v4 06/11] s390/module: Use s390_kernel_write() for late relocations

Gerald Schaefer
2020-05-07T12:28:01Z

On Thu, 7 May 2020 12:00:13 +0200 (CEST)
Jiri Kosina <jikos@kernel.org> wrote:

> On Wed, 29 Apr 2020, Josh Poimboeuf wrote:
>
> > From: Peter Zijlstra <peterz@infradead.org>
> >
> > Because of late module patching, a livepatch module needs to be able to
> > apply some of its relocations well after it has been loaded. Instead of
> > playing games with module_{dis,en}able_ro(), use existing text poking
> > mechanisms to apply relocations after module loading.
> >
> > So far only x86, s390 and Power have HAVE_LIVEPATCH but only the first
> > two also have STRICT_MODULE_RWX.
> >
> > This will allow removal of the last module_disable_ro() usage in
> > livepatch. The ultimate goal is to completely disallow making
> > executable mappings writable.
> >
> > [ jpoimboe: Split up patches. Use mod state to determine whether
> > memcpy() can be used. Test and add fixes. ]
> >
> > Cc: linux-s390@vger.kernel.org
> > Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
> > Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
> > Cc: Christian Borntraeger <borntraeger@de.ibm.com>
> > Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
> > Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> > Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
> > Acked-by: Miroslav Benes <mbenes@suse.cz>
>
> Could we please get an Ack / Reviewed-by: for this patch from s390 folks?
>
> Thanks,
>

Looks pretty straightforward, and using s390_kernel_write() is OK, so

Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> # s390