lkml.org 
[lkml]   [2020]   [Feb]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v26 10/22] x86/sgx: Linux Enclave Driver
    On Thu, Feb 20, 2020 at 10:48:42AM -0800, Sean Christopherson wrote:
    > My biggest concern for allowing PROT_EXEC if RIE is that it would result
    > in #PF(SGX) (#GP on Skylake) due to an EPCM violation if the enclave
    > actually tried to execute from such a page. This isn't a problem for the
    > kernel as the fault will be reported cleanly through the vDSO (or get
    > delivered as a SIGSEGV if the enclave isn't entered through the vDSO), but
    > it's a bit weird for userspace as userspace will see the #PF(SGX) and
    > likely assume the EPC was lost, e.g. silently restart the enclave instead
    > of logging an error that the enclave is broken.

    I think right way to fix the current implementation is to -EACCES mmap()
    (and mprotect) when !!(current->personality & READ_IMPLIES_EXEC).

    This way supporting RIE can be reconsidered later on without any
    potential ABI bottlenecks.

    /Jarkko

    \
     
     \ /
      Last update: 2020-02-20 23:16    [W:2.712 / U:0.012 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site