Re: [PATCH v2 1/1] KVM: s390: fix race in gmap_make_secure

Heiko Carstens
2023-04-27T10:53:31Z

On Wed, Apr 26, 2023 at 03:48:34PM +0200, Claudio Imbrenda wrote:
> This patch fixes a potential race in gmap_make_secure and removes the
> last user of follow_page without FOLL_GET.
>
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
> Fixes: 214d9bbcd3a6 ("s390/mm: provide memory management functions for protected KVM guests")
> ---
> arch/s390/kernel/uv.c | 32 +++++++++++---------------------
> 1 file changed, 11 insertions(+), 21 deletions(-)

It would be helpful if this would be a bit more descriptive. "Fix
race" is not very helpful :)

What race does this fix?
When can this happen?
What are the consequences if the race window is being hit?