On Tue, Oct 10, 2017 at 05:32:53PM +0300, Jarkko Sakkinen wrote:
> diff --git a/drivers/platform/x86/intel_sgx/sgx_encl.c b/drivers/platform/x86/intel_sgx/sgx_encl.c
> new file mode 100644
> index 000000000000..aa0deed08cee
> --- /dev/null
> +++ b/drivers/platform/x86/intel_sgx/sgx_encl.c
> @@ -0,0 +1,989 @@
>
> +/**
> + * sgx_encl_find - find an enclave
> + * @mm: mm struct of the current process
> + * @addr: address in the ELRANGE
> + * @created is the enclave already created?
> + * @vma: the resulting VMA
> + *
> + * Finds an enclave identified by the given address. Gives back the VMA, that is
> + * part of the enclave, located in that address.
> + *
> + * Return:
> + * 0 on success,
> + * -EINVAL if not found,
> + */
> +int sgx_encl_find(struct mm_struct *mm, unsigned long addr, bool created,
> + struct vm_area_struct **vma)
> +{
> + struct vm_area_struct *result;
> + struct sgx_encl *encl;
> +
> + result = find_vma(mm, addr);
> + if (!result || result->vm_ops != &sgx_vm_ops || addr < result->vm_start)
> + return -EINVAL;
> +
> + encl = result->vm_private_data;
> + if (created) {
> + if (!encl)
> + return -EINVAL;
> + } else {
> + if (encl)
> + return -EINVAL;
> + }
What about removing @created and returning -ENOENT (or -ENXIO?) if
result->vm_private_data is NULL? Removing @created will eliminate
any potential confusion for the common case of @created=true. For
@created=false, which should be limited to sgx_encl_create, I think
that explicitly checking for "ret != -ENOENT" is more intuitive
than checking whether or not sgx_encl_find succeeded, e.g. I knew
the intent of the check in sgx_encl_create ahead of time and I still
had to walk through sgx_encl_find to verify the behavior.
> +
> + *vma = result;
> + return 0;
> +}
> +
