On Mon, Aug 26, 2019 at 08:59:34AM +0300, Jarkko Sakkinen wrote: > On Mon, Aug 26, 2019 at 08:32:48AM +0300, Jarkko Sakkinen wrote: > > Refine the kdoc of sgx_ioc_enclave_add_page() with a proper description > > about the interaction with mmap(). Without documentation, it is > > impossible to review the code change. > > > > Cc: Serge Ayoun <serge.ayoun@xxxxxxxxx> > > Cc: Casey Schaufler <casey@xxxxxxxxxxxxxxxx> > > Cc: Sean Christoherson <sean.j.christopherson@xxxxxxxxx> > > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx> > > I squashed this. Further defined the documentation to also address TCS: /** * sgx_ioc_enclave_add_page() - The handler for %SGX_IOC_ENCLAVE_ADD_PAGE * @filep: open file to /dev/sgx * @arg: a user pointer to a struct sgx_enclave_add_page instance * * Add (EADD) a page to an uninitialized enclave, and optionally extend * (EEXTEND) the measurement with the contents of the page. 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. * * Return: * 0 on success, * -EINVAL if the SECINFO contains invalid data, * -EACCES if the source page is located in a noexec partition, * -ENOMEM if any memory allocation, including EPC, fails, * -errno otherwise */ Saw no point to cycle this here other than mention about the change. I'd say now it starts to be throughout enough. /Jarkko
