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 <yaojun8558...@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
