Add a new helper reloc_kernel_entry() to jump back to the start of the new kernel. After we put the new kernel in a randomized place we can use this new helper to enter the kernel and begin to relocate again.
Signed-off-by: Jason Yan <yanai...@huawei.com> Cc: Diana Craciun <diana.crac...@nxp.com> Cc: Michael Ellerman <m...@ellerman.id.au> Cc: Christophe Leroy <christophe.le...@c-s.fr> Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> Cc: Paul Mackerras <pau...@samba.org> Cc: Nicholas Piggin <npig...@gmail.com> Cc: Kees Cook <keesc...@chromium.org> Reviewed-by: Christophe Leroy <christophe.le...@c-s.fr> Reviewed-by: Diana Craciun <diana.crac...@nxp.com> Tested-by: Diana Craciun <diana.crac...@nxp.com> --- arch/powerpc/kernel/head_fsl_booke.S | 13 +++++++++++++ arch/powerpc/mm/mmu_decl.h | 1 + 2 files changed, 14 insertions(+) diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S index 8c1928176ffe..d9f599b01ff1 100644 --- a/arch/powerpc/kernel/head_fsl_booke.S +++ b/arch/powerpc/kernel/head_fsl_booke.S @@ -1149,6 +1149,19 @@ _GLOBAL(create_kaslr_tlb_entry) sync blr +/* + * Return to the start of the relocated kernel and run again + * r3 - virtual address of fdt + * r4 - entry of the kernel + */ +_GLOBAL(reloc_kernel_entry) + mfmsr r7 + rlwinm r7, r7, 0, ~(MSR_IS | MSR_DS) + + mtspr SPRN_SRR0,r4 + mtspr SPRN_SRR1,r7 + rfi + /* * Create a tlb entry with the same effective and physical address as * the tlb entry used by the current running code. But set the TS to 1. diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h index a492ece08f64..55e86a0bf562 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -143,6 +143,7 @@ extern void adjust_total_lowmem(void); extern int switch_to_as1(void); extern void restore_to_as0(int esel, int offset, void *dt_ptr, int bootcpu); void create_kaslr_tlb_entry(int entry, unsigned long virt, phys_addr_t phys); +void reloc_kernel_entry(void *fdt, int addr); #endif extern void loadcam_entry(unsigned int index); extern void loadcam_multi(int first_idx, int num, int tmp_idx); -- 2.17.2