lkml.org 
[lkml]   [2020]   [Jun]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: [PATCH v3 7/7] x86/boot: Check that there are no runtime relocations
    On Mon, Jun 29, 2020 at 09:20:31AM -0700, Kees Cook wrote:
    > On Mon, Jun 29, 2020 at 06:11:59PM +0200, Ard Biesheuvel wrote:
    > > On Mon, 29 Jun 2020 at 18:09, Kees Cook <keescook@chromium.org> wrote:
    > > >
    > > > Should these be marked (INFO) as well?
    > > >
    > >
    > > Given that sections marked as (INFO) will still be emitted into the
    > > ELF image, it does not really make a difference to do this for zero
    > > sized sections.
    >
    > Oh, I misunderstood -- I though they were _not_ emitted; I see now what
    > you said was not allocated. So, disk space used for the .got.plt case,
    > but not memory space used. Sorry for the confusion!
    >
    > -Kees
    >

    To confuse the issue a bit more, there are subtleties around "disk space
    used" :) The section will be present in the ELF format file, but at
    least on x86, that file is then converted into binary format via
    objcopy. At this point a non-allocated section at the end of the file
    will be stripped off. So on 32-bit x86, moving .got.plt to the end and
    marking it INFO will shave 16 bytes off the bzImage kernel.

    \
     
     \ /
      Last update: 2020-06-29 20:44    [W:4.058 / U:0.048 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site