On Mon, Oct 28, 2019 at 11:03:12PM +0200, Jarkko Sakkinen wrote: > +/** > + * sgx_ioc_enclave_add_pages() - The handler for %SGX_IOC_ENCLAVE_ADD_PAGES > + * @encl: pointer to an enclave instance (via ioctl() file pointer) > + * @arg: a user pointer to a struct sgx_enclave_add_pages instance > + * > + * Add (EADD) one or more pages to an uninitialized enclave, and optionally > + * extend (EEXTEND) the measurement with the contents of the page. The range of > + * pages must be virtually contiguous. The SECINFO and measurement mask are > + * applied to all pages, i.e. pages with different properties must be added in > + * separate calls. > + * > + * A SECINFO for a TCS is required to always contain zero permissions because > + * CPU silently zeros them. Allowing anything else would cause a mismatch in > + * the measurement. > + * > + * mmap()'s protection bits are capped by the page permissions. For each page > + * address, the maximum protection bits are computed with the following > + * heuristics: > + * > + * 1. A regular page: PROT_R, PROT_W and PROT_X match the SECINFO permissions. > + * 2. A TCS page: PROT_R | PROT_W. > + * 3. No page: PROT_NONE. > + * > + * mmap() is not allowed to surpass the minimum of the maximum protection bits > + * within the given address range. > + * > + * As stated above, a non-existent page is interpreted as a page with no > + * permissions. In effect, this allows mmap() with PROT_NONE to be used to seek > + * an address range for the enclave that can be then populated into SECS. > + * > + * @arg->addr, @arg->src and @arg->length are adjusted to reflect the > + * remaining pages that need to be added to the enclave, e.g. userspace can > + * re-invoke SGX_IOC_ENCLAVE_ADD_PAGES using the same struct in response to an > + * ERESTARTSYS error. > + * > + * Return: > + * 0 on success, > + * -EINVAL if any input param or the SECINFO contains invalid data, > + * -EACCES if an executable source page is located in a noexec partition, > + * -ENOMEM if any memory allocation, including EPC, fails, > + * -ERESTARTSYS if a pending signal is recognized > + */ > +static long sgx_ioc_enclave_add_pages(struct sgx_encl *encl, void __user *arg) This should return the number of pages processed instead of zero on success. Kernel needs to be able to cap the amount it will process. /Jarkko
