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&state=* 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. v4->v5: Fix "-Werror=maybe-uninitialized" compile error. Fix typo "similar as" -> "similar to". v3->v4: Do not define __kaslr_offset as a fixed symbol. Reference __run_at_load and __kaslr_offset by symbol instead of magic offsets. Use IS_ENABLED(CONFIG_PPC32) instead of #ifdef CONFIG_PPC32. Change kaslr-booke32 to kaslr-booke in index.rst Switch some instructions to 64-bit. 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 Documentation/powerpc/index.rst | 2 +- .../{kaslr-booke32.rst => kaslr-booke.rst} | 35 ++++++- arch/powerpc/Kconfig | 2 +- arch/powerpc/kernel/exceptions-64e.S | 23 +++++ arch/powerpc/kernel/head_64.S | 13 +++ arch/powerpc/kernel/setup_64.c | 3 + arch/powerpc/mm/mmu_decl.h | 23 +++-- arch/powerpc/mm/nohash/kaslr_booke.c | 91 +++++++++++++------ 8 files changed, 147 insertions(+), 45 deletions(-) rename Documentation/powerpc/{kaslr-booke32.rst => kaslr-booke.rst} (59%) -- 2.17.2
