[RFC PATCH v4 09/12] LSM: x86/sgx: Introduce ->enclave_load() hook for Intel SGX

[Xing, Cedric]

> From: Christopherson, Sean J
> Sent: Wednesday, June 19, 2019 3:24 PM
> 
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 6a1f54ba6794..572ddfc53039 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -1832,11 +1832,18 @@ static inline void security_bpf_prog_free(struct bpf_prog_aux *aux)
>  #ifdef CONFIG_INTEL_SGX
>  #ifdef CONFIG_SECURITY
>  int security_enclave_map(unsigned long prot);
> +int security_enclave_load(struct vm_area_struct *vma, unsigned long prot,
> +			  bool measured);
>  #else
>  static inline int security_enclave_map(unsigned long prot)
>  {
>  	return 0;
>  }
> +static inline int security_enclave_load(struct vm_area_struct *vma,
> +					unsigned long prot, bool measured)
> +{
> +	return 0;
> +}
>  #endif /* CONFIG_SECURITY */
>  #endif /* CONFIG_INTEL_SGX */

Parameters to security_enclave_load() are specific on what's being loading only, but unspecific on which enclave to be loaded into. That kills the possibility of an LSM module making enclave dependent decisions.

Btw, if enclave (in the form of struct file) is also passed in as a parameter, it'd let LSM know that file is an enclave, hence would be able to make the same decision in security_mmap_file() as in security_enclave_map(). In other words, you wouldn't need security_enclave_map().