On 24.09.21 10:58, Peng Fan wrote:
> Jan,
>
> With the commit, enter_hypervisor->entry will not work anymore, because it is 
> not
> executable now! Any suggestion?
>
> commit 8491502f787c4a902bd4f223b578ef47d3490264
> Author: Christoph Hellwig <[email protected]>
> Date:   Tue Sep 7 19:56:04 2021 -0700
>
>     mm: don't allow executable ioremap mappings
>
>     There is no need to execute from iomem (and most platforms it is
>     impossible anyway), so add the pgprot_nx() call similar to vmap.
>
>     Link: https://lkml.kernel.org/r/[email protected]
>     Signed-off-by: Christoph Hellwig <[email protected]>
>     Cc: Nicholas Piggin <[email protected]>
>     Cc: Peter Zijlstra <[email protected]>
>     Signed-off-by: Andrew Morton <[email protected]>
>     Signed-off-by: Linus Torvalds <[email protected]>
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index e44983fb2d156..3055f04b486bb 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -316,7 +316,7 @@ int ioremap_page_range(unsigned long addr, unsigned long 
> end,
>  {
>         int err;
>
> -       err = vmap_range_noflush(addr, end, phys_addr, prot,
> +       err = vmap_range_noflush(addr, end, phys_addr, pgprot_nx(prot),
>                                  ioremap_max_page_shift);
>         flush_cache_vmap(addr, end);
>         return err;
>
> Thanks,
> Peng
>

Two options come to my mind:

 - carry another revert in the Jailhouse kernel branch (we already have
   some there...)

 - explore using a different mapping mechanism or a different page
   source that permit executable mappings for the trampoline pages
   (those used before activating Jailhouse's own mappings)

The latter would only work for arm64 so far (JAILHOUSE_BORROW_ROOT_PT),
but other archs should be converted to that scheme eventually.

Jan

-- 
You received this message because you are subscribed to the Google Groups 
"Jailhouse" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To view this discussion on the web visit 
https://groups.google.com/d/msgid/jailhouse-dev/bb692a80-925b-ae39-1681-d98874810c5a%40web.de.

Reply via email to