Messages in this thread Patch in this message | | | From | Jun Yao <> | Subject | [PATCH v5 3/6] arm64/mm: Create the initial page table in the init_pg_dir. | Date | Mon, 17 Sep 2018 12:43:30 +0800 |
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Create the initial page table in the init_pg_dir. And update the init_mm.pgd to make sure that pgd_offset_k() works correctly. When the final page table is created, we redirect the init_mm.pgd to the swapper_pg_dir.
Signed-off-by: Jun Yao <yaojun8558363@gmail.com> --- arch/arm64/include/asm/pgtable.h | 2 ++ arch/arm64/kernel/asm-offsets.c | 1 + arch/arm64/kernel/head.S | 9 +++++++-- arch/arm64/mm/mmu.c | 1 + 4 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 2ab2031b778c..b11d6fc62a62 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -718,6 +718,8 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, } #endif +extern pgd_t init_pg_dir[PTRS_PER_PGD]; +extern pgd_t init_pg_end[]; extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; extern pgd_t swapper_pg_end[]; extern pgd_t idmap_pg_dir[PTRS_PER_PGD]; diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 323aeb5f2fe6..43f52cfdfad4 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -82,6 +82,7 @@ int main(void) DEFINE(S_FRAME_SIZE, sizeof(struct pt_regs)); BLANK(); DEFINE(MM_CONTEXT_ID, offsetof(struct mm_struct, context.id.counter)); + DEFINE(MM_PGD, offsetof(struct mm_struct, pgd)); BLANK(); DEFINE(VMA_VM_MM, offsetof(struct vm_area_struct, vm_mm)); DEFINE(VMA_VM_FLAGS, offsetof(struct vm_area_struct, vm_flags)); diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index de2aaea00bd2..cf8a58211b80 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -376,7 +376,7 @@ __create_page_tables: /* * Map the kernel image (starting with PHYS_OFFSET). */ - adrp x0, swapper_pg_dir + adrp x0, init_pg_dir mov_q x5, KIMAGE_VADDR + TEXT_OFFSET // compile time __va(_text) add x5, x5, x23 // add KASLR displacement mov x4, PTRS_PER_PGD @@ -439,6 +439,11 @@ __primary_switched: bl __pi_memset dsb ishst // Make zero page visible to PTW + // Update init_mm.pgd + adrp x0, init_pg_dir + adr_l x1, init_mm + str x0, [x1, #MM_PGD] + #ifdef CONFIG_KASAN bl kasan_early_init #endif @@ -833,7 +838,7 @@ __primary_switch: mrs x20, sctlr_el1 // preserve old SCTLR_EL1 value #endif - adrp x1, swapper_pg_dir + adrp x1, init_pg_dir bl __enable_mmu #ifdef CONFIG_RELOCATABLE bl __relocate_kernel diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 65f86271f02b..af80dca335ce 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -646,6 +646,7 @@ void __init paging_init(void) cpu_replace_ttbr1(__va(pgd_phys)); memcpy(swapper_pg_dir, pgdp, PGD_SIZE); cpu_replace_ttbr1(lm_alias(swapper_pg_dir)); + init_mm.pgd = swapper_pg_dir; pgd_clear_fixmap(); memblock_free(pgd_phys, PAGE_SIZE); -- 2.17.1
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