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on 2020/2/13 11:00, Jason Yan wrote:
Hi everyone, any comments or suggestions?

Thanks,
Jason

on 2020/2/6 10:58, Jason Yan wrote:
This is a try to implement KASLR for Freescale BookE64 which is based on
my earlier implementation for Freescale BookE32:
https://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=131718

The implementation for Freescale BookE64 is similar as BookE32. One
difference is that Freescale BookE64 set up a TLB mapping of 1G during
booting. Another difference is that ppc64 needs the kernel to be
64K-aligned. So we can randomize the kernel in this 1G mapping and make
it 64K-aligned. This can save some code to creat another TLB map at
early boot. The disadvantage is that we only have about 1G/64K = 16384
slots to put the kernel in.

     KERNELBASE

           64K                     |--> kernel <--|
            |                      |              |
         +--+--+--+    +--+--+--+--+--+--+--+--+--+    +--+--+
         |  |  |  |....|  |  |  |  |  |  |  |  |  |....|  |  |
         +--+--+--+    +--+--+--+--+--+--+--+--+--+    +--+--+
         |                         |                        1G
         |----->   offset    <-----|

                               kernstart_virt_addr

I'm not sure if the slot numbers is enough or the design has any
defects. If you have some better ideas, I would be happy to hear that.

Thank you all.

v2->v3:
   Fix build error when KASLR is disabled.
v1->v2:
   Add __kaslr_offset for the secondary cpu boot up.

Jason Yan (6):
   powerpc/fsl_booke/kaslr: refactor kaslr_legal_offset() and
     kaslr_early_init()
   powerpc/fsl_booke/64: introduce reloc_kernel_entry() helper
   powerpc/fsl_booke/64: implement KASLR for fsl_booke64
   powerpc/fsl_booke/64: do not clear the BSS for the second pass
   powerpc/fsl_booke/64: clear the original kernel if randomized
   powerpc/fsl_booke/kaslr: rename kaslr-booke32.rst to kaslr-booke.rst
     and add 64bit part

  .../{kaslr-booke32.rst => kaslr-booke.rst}    | 35 +++++++--
  arch/powerpc/Kconfig                          |  2 +-
  arch/powerpc/kernel/exceptions-64e.S          | 23 ++++++
  arch/powerpc/kernel/head_64.S                 | 14 ++++
  arch/powerpc/kernel/setup_64.c                |  4 +-
  arch/powerpc/mm/mmu_decl.h                    | 19 ++---
  arch/powerpc/mm/nohash/kaslr_booke.c          | 71 +++++++++++++------
  7 files changed, 132 insertions(+), 36 deletions(-)
  rename Documentation/powerpc/{kaslr-booke32.rst => kaslr-booke.rst} (59%)



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