Le 30/07/2019 à 09:42, Jason Yan a écrit :
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 <yanaijie@xxxxxxxxxx>
Cc: Diana Craciun <diana.craciun@xxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
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 04d124fee17d..2083382dd662 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -1143,6 +1143,19 @@ _GLOBAL(create_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 a09f89d3aa0f..804da298beb3 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_tlb_entry(phys_addr_t phys, unsigned long virt, int entry);
+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);
