Hi Reinette and Jarkko, > On Thu, Apr 21, 2022 at 08:29:31PM -0700, Reinette Chatre wrote: > > Hi Vijay and Mark, > > > > On 4/21/2022 4:46 PM, Dhanraj, Vijay wrote: > > > Hi All, > > > > > > I evaluated V4 patch changes with Gramine and ran into an issue when > trying to set EPC page permission to PROT_NONE. It looks like with V3 patch > series a change was introduced which requires kernel to have at least R > permission when calling RESTRICT IOCTL. This change was done under the > assumption that EPCM requires at least R permission for EMODPE/EACCEPT > to succeed. But when testing with V2 version, EACCEPT worked fine with > page permission set to PROT_NONE. > > > > > > Thanks to @Shanahan, Mark for confirming that EPCM does not need to > have R value to allow EACCEPT or EMODPE. Given this, can we please revert > this change? > > > > > > > Thank you very much for pointing this out. I can revert the change to > > what was done in V2 where the only check is to ensure that W requires R. > > This is a requirement of EMODPR. Could you please check if this > > snippet results in things working for you again? > > > > ---8<--- > > diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c > > b/arch/x86/kernel/cpu/sgx/ioctl.c index 83674d054c13..7c7c8a61196e > > 100644 > > --- a/arch/x86/kernel/cpu/sgx/ioctl.c > > +++ b/arch/x86/kernel/cpu/sgx/ioctl.c > > @@ -855,12 +855,8 @@ static long > sgx_ioc_enclave_restrict_permissions(struct sgx_encl *encl, > > if (params.permissions & ~SGX_SECINFO_PERMISSION_MASK) > > return -EINVAL; > > > > - /* > > - * Read access is required for the enclave to be able to use the page. > > - * SGX instructions like ENCLU[EMODPE] and ENCLU[EACCEPT] > require > > - * read access. > > - */ > > - if (!(params.permissions & SGX_SECINFO_R)) > > + if ((params.permissions & SGX_SECINFO_W) && > > + !(params.permissions & SGX_SECINFO_R)) > > return -EINVAL; > > > > if (params.result || params.count) > > Just adding that it's fine for me to revert this. Thanks, I verified your patch and now I am able to set EPCM page permission with PROT_NONE. I also verified the following SGX2 interfaces, SGX_IOC_ENCLAVE_MODIFY_TYPES SGX_IOC_ENCLAVE_REMOVE_PAGES SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS And also tested dynamically adding pages to enclave using #PF based approach and this works as expected. Please feel free to add my Tested-by for the below patches which test the above IOCTLs [PATCH V4 16/31] x86/sgx: Support adding of pages to an initialized enclave [PATCH V4 15/31] x86/sgx: Support restricting of enclave page permissions [PATCH V4 18/31] x86/sgx: Support modifying SGX page type [PATCH V4 19/31] x86/sgx: Support complete page removal > > BR, Jarkko
