On Tue, 2018-09-25 at 16:06 +0300, Jarkko Sakkinen wrote:
> Intel Software Guard eXtensions (SGX) is a set of CPU instructions that
> can be used by applications to set aside private regions of code and
> data. The code outside the enclave is disallowed to access the memory
> inside the enclave by the CPU access control.
>
> SGX driver provides a ioctl API for loading and initializing enclaves.
> Address range for enclaves is reserved with mmap() and they are
> destroyed with munmap(). Enclave construction, measurement and
> initialization is done with the provided the ioctl API.
...
> +/**
> + * sgx_ioc_enclave_init - handler for %SGX_IOC_ENCLAVE_INIT
> + *
> + * @filep: open file to /dev/sgx
> + * @cmd: the command value
> + * @arg: pointer to an &sgx_enclave_init instance
> + *
> + * Flushes the remaining enqueued EADD operations and performs EINIT. Does not
> + * allow the EINITTOKENKEY attribute for an enclave.
> + *
> + * Return:
> + * 0 on success,
> + * SGX error code on EINIT failure,
> + * -errno otherwise
> + */
> +static long sgx_ioc_enclave_init(struct file *filep, unsigned int cmd,
> + unsigned long arg)
> +{
> + struct sgx_enclave_init *initp = (struct sgx_enclave_init *)arg;
> + struct sgx_sigstruct *sigstruct;
> + struct sgx_einittoken *einittoken;
> + struct sgx_encl *encl;
> + struct page *initp_page;
> + int ret;
> +
> + initp_page = alloc_page(GFP_HIGHUSER);
> + if (!initp_page)
> + return -ENOMEM;
> +
> + sigstruct = kmap(initp_page);
> + einittoken = (struct sgx_einittoken *)
> + ((unsigned long)sigstruct + PAGE_SIZE / 2);
> + memset(einittoken, 0, sizeof(*einittoken));
> +
> + ret = copy_from_user(sigstruct, (void __user *)initp->sigstruct,
> + sizeof(*sigstruct));
> + if (ret)
> + goto out;
> + if (sigstruct->attributes & SGX_ATTR_EINITTOKENKEY) {
> + ret = EINVAL;
This should be "ret = -EINVAL".
> + goto out;
> + }
> +
> + ret = sgx_encl_get(initp->addr, &encl);
> + if (ret)
> + goto out;
> +
> + ret = sgx_encl_init(encl, sigstruct, einittoken);
> +
> + kref_put(&encl->refcount, sgx_encl_release);
> +
> +out:
> + kunmap(initp_page);
> + __free_page(initp_page);
> + return ret;
> +}
