Re: [PATCH v13 5/5] x86/sgx: Enable automatic SVN updates for SGX enclaves

[Huang, Kai]

> 
> Note: while in such cases the underlying crypto assets are regenrated, it
							     ^
							     regenerated


[...]

> +/* Mutex to ensure no concurrent EPC accesses during EUPDATESVN */
> +static DEFINE_MUTEX(sgx_svn_lock);
> +
>  int sgx_inc_usage_count(void)
>  {
> +	int ret;
> +
> +	guard(mutex)(&sgx_svn_lock);
> +
> +	if (sgx_usage_count++ == 0) {
> +		ret = sgx_update_svn();
> +		if (ret)
> +			sgx_usage_count--;
> +		return ret;
> +	}
> +

To me, I would prefer:

int sgx_inc_usage_count(void)
{
	guard(mutex)(&sgx_svn_lock);

	if (!sgx_usage_count) {
		int ret = sgx_update_svn();
		if (ret)
			return ret;
	}

	sgx_usage_count++;

	return 0;
}