[RFC PATCH 8/9] LSM: x86/sgx: Introduce ->enclave_load() hook for Intel SGX

[Xing, Cedric]

> From: Christopherson, Sean J
> Sent: Friday, May 31, 2019 4:32 PM
> 
> diff --git a/include/linux/security.h b/include/linux/security.h index
> 659071c2e57c..2f7925eeef7e 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -392,6 +392,8 @@ void security_inode_invalidate_secctx(struct inode *inode);  int
> security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);  int
> security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen);  int
> security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen);
> +int security_enclave_load(struct vm_area_struct *vma, unsigned long prot,
> +			  unsigned long *allowed_prot);

Per my comments to the cover letter, security_enclave_load() should have a signature similar to the following:

int security_enclave_load(struct file *enclave_fd, unsigned long linear_address, unsigned long nr_pages, int prot, struct vm_area_struct *source_vma);

@enclave_fd identifies the enclave to which new pages are being added.
@linear_address/@nr_pages specifies the linear range of pages being added.
@prot specifies the initial protection of those newly added pages. It is taken from the vma covering the target range.
@source_vma covers the source pages in the case of EADD. An LSM is expected to make sure security_file_mprotect(source_vma, prot, prot) would succeed before checking anything else, unless @source_vma is NULL, indicating pages are being EAUG'ed. In all cases, LSM is expected to "remember" @prot for all those pages to be checked in future security_file_mprotect() invocations.

>  #else /* CONFIG_SECURITY */