Re: [PATCH v34 12/24] x86/sgx: Add SGX_IOC_ENCLAVE_CREATE

[Sean Christopherson]

On Tue, Jul 07, 2020 at 06:01:52AM +0300, Jarkko Sakkinen wrote:
> +long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
> +{
> +	struct sgx_encl *encl = filep->private_data;
> +	int ret, encl_flags;
> +
> +	encl_flags = atomic_fetch_or(SGX_ENCL_IOCTL, &encl->flags);
> +	if (encl_flags & SGX_ENCL_IOCTL)
> +		return -EBUSY;

As called out in my belated feedback, SGX_ENCL_DEAD needs to be checked
here to prevent invoking ENCLS operations on a dead enclave.  If you're
splitting hairs, the check could technically be deferred until the next
patch, "Add SGX_IOC_ENCLAVE_ADD_PAGES", which is the first usage of
sgx_encl_destroy() from an ioctl(), but that seems a bit gratuitous.

> +
> +	switch (cmd) {
> +	case SGX_IOC_ENCLAVE_CREATE:
> +		ret = sgx_ioc_enclave_create(encl, (void __user *)arg);
> +		break;
> +	default:
> +		ret = -ENOIOCTLCMD;
> +		break;
> +	}
> +
> +	atomic_andnot(SGX_ENCL_IOCTL, &encl->flags);
> +	return ret;
> +}
> -- 
> 2.25.1
>