lkml.org 
[lkml]   [2012]   [Sep]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: [PATCH 00/11] x86: Supervisor Mode Access Prevention
    "H. Peter Anvin" <hpa@linux.intel.com> writes:

    > On 09/21/2012 03:07 PM, Eric W. Biederman wrote:
    >>
    >> Have you tested kexec in this environment?
    >>
    >> This is the kind of cpu feature that when we enable it, frequently we
    >> have to do something on the kexec path.
    >>
    >> At a quick skim it looks like the kexec path is using kernel page table
    >> entries and clearing all bits from cr4 except X86_CR4_PAE so I don't
    >> actually expect this change will require anything on the kexec path.
    >>
    >
    > I have not, no, but as you quite correctly point out that shouldn't
    > affect things.
    >
    > We should also change the kernel to start clean with CR4 -- the purpose
    > of CR4 is to indicate which CPU features the OS is opting into.
    >
    > I think we do on x86-64 but not on x86-32 at the moment.
    >
    > This is an unrelated problem, though, and can be addressed later.

    Agreed. I just was just curious where things stood.

    Eric



    \
     
     \ /
      Last update: 2012-09-22 03:41    [W:3.959 / U:0.064 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site