On Mon, May 09, 2022 at 02:48:00PM -0700, Reinette Chatre wrote:
> Recent commit 08999b2489b4 ("x86/sgx: Free backing memory
> after faulting the enclave page") expanded __sgx_encl_eldu()
> to clear an enclave page's PCMD (Paging Crypto MetaData)
> from the PCMD page in the backing store after the enclave
> page is restored to the enclave.
>
> Since the PCMD page in the backing store is modified the page
> should be marked as dirty to ensure the modified data is retained.
>
> Fixes: 08999b2489b4 ("x86/sgx: Free backing memory after faulting the enclave page")
> Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
> ---
> Changes since RFC v1:
> - Do not set dirty bit on enclave page since it is not being
> written to and always will be discarded. (Dave)
>
> arch/x86/kernel/cpu/sgx/encl.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
> index 398695a20605..2521d64e8bcf 100644
> --- a/arch/x86/kernel/cpu/sgx/encl.c
> +++ b/arch/x86/kernel/cpu/sgx/encl.c
> @@ -83,6 +83,7 @@ static int __sgx_encl_eldu(struct sgx_encl_page *encl_page,
> ret = -EFAULT;
> }
>
> + set_page_dirty(b.pcmd);
> memset(pcmd_page + b.pcmd_offset, 0, sizeof(struct sgx_pcmd));
>
> /*
> --
> 2.25.1
>
LGTM.
Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
BR, Jarkko
