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

[Jiri Kosina]

On Wed, 29 Apr 2020, Josh Poimboeuf wrote:

> From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> 
> 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@xxxxxxxxxxxxxxx
> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
> Cc: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx>
> Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> Suggested-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> Acked-by: Joe Lawrence <joe.lawrence@xxxxxxxxxx>
> Acked-by: Miroslav Benes <mbenes@xxxxxxx>

Could we please get an Ack / Reviewed-by: for this patch from s390 folks?

Thanks,

-- 
Jiri Kosina
SUSE Labs