On Wed, Jun 19, 2019 at 03:21:43PM +0300, Jarkko Sakkinen wrote:
> With the file bound approach we can flush the work queue when the file
> is closed.
>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> ---
> arch/x86/kernel/cpu/sgx/driver/ioctl.c | 3 +--
> arch/x86/kernel/cpu/sgx/driver/main.c | 1 +
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/sgx/driver/ioctl.c b/arch/x86/kernel/cpu/sgx/driver/ioctl.c
> index d17c60dca114..f56d3c712dc4 100644
> --- a/arch/x86/kernel/cpu/sgx/driver/ioctl.c
> +++ b/arch/x86/kernel/cpu/sgx/driver/ioctl.c
> @@ -172,7 +172,7 @@ static void sgx_add_page_worker(struct work_struct *work)
>
> next:
> kfree(req);
> - } while (!kref_put(&encl->refcount, sgx_encl_release) && !is_empty);
> + } while (!is_empty);
> }
>
> static u32 sgx_calc_ssaframesize(u32 miscselect, u64 xfrm)
> @@ -520,7 +520,6 @@ static int __sgx_encl_add_page(struct sgx_encl *encl,
> req->encl_page = encl_page;
> req->mrmask = mrmask;
> empty = list_empty(&encl->add_page_reqs);
> - kref_get(&encl->refcount);
> list_add_tail(&req->list, &encl->add_page_reqs);
> if (empty)
> queue_work(sgx_encl_wq, &encl->work);
> diff --git a/arch/x86/kernel/cpu/sgx/driver/main.c b/arch/x86/kernel/cpu/sgx/driver/main.c
> index 0c831ee5e2de..9ea082372682 100644
> --- a/arch/x86/kernel/cpu/sgx/driver/main.c
> +++ b/arch/x86/kernel/cpu/sgx/driver/main.c
> @@ -47,6 +47,7 @@ static int sgx_release(struct inode *inode, struct file *file)
> {
> struct sgx_encl *encl = file->private_data;
>
> + flush_work(&encl->work);
We should set SGX_ENCL_DEAD before flush_work(). Other than that I can't
think of any issues with this approach. Though hopefully we can purge the
worker altogether and make it a moot point :-).
> kref_put(&encl->refcount, sgx_encl_release);
>
> return 0;
> --
> 2.20.1
>
