On Thu, Sep 01, 2022 at 10:35:07AM -0700, Suren Baghdasaryan wrote:
> Due to the possibility of do_swap_page dropping mmap_lock, abort fault
> handling under VMA lock and retry holding mmap_lock. This can be handled
> more gracefully in the future.
>
> Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
> ---
> mm/memory.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/mm/memory.c b/mm/memory.c
> index 9ac9944e8c62..29d2f49f922a 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -3738,6 +3738,11 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
> vm_fault_t ret = 0;
> void *shadow = NULL;
>
> + if (vmf->flags & FAULT_FLAG_VMA_LOCK) {
> + ret = VM_FAULT_RETRY;
> + goto out;
> + }
> +
May want to fail early similarly for handle_userfault() too for similar
reason. Thanks,
--
Peter Xu
