Commit fdfd3c17 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Zheng Zengkai
Browse files

ARM: kernel: refer to swapper_pg_dir via its symbol 

maillist inclusion
commit fe64d7efe89877bc52454f9f2bc9ab0ce01ae8fc
category: feature
feature: ARM kaslr support
bugzilla: 47952
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git/commit/?h=arm-kaslr-latest&id=fe64d7efe89877bc52454f9f2bc9ab0ce01ae8fc



-------------------------------------------------

The location of swapper_pg_dir is relative to the kernel, not to
PAGE_OFFSET or PHYS_OFFSET. So define the symbol relative to the
start of the kernel image, and refer to it via its name.

Cc: Russell King <linux@armlinux.org.uk>
Acked-by: default avatarNicolas Pitre <nico@linaro.org>
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarCui GaoSheng <cuigaosheng1@huawei.com>
Reviewed-by: default avatarXiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 05bfa534

arch/arm/kernel/head.S

+4 −9
Original line number Diff line number Diff line
@@ -45,14 +45,6 @@ 
#define PMD_ORDER	2

#endif



	.globl	swapper_pg_dir

	.equ	swapper_pg_dir, KERNEL_RAM_VADDR - PG_DIR_SIZE



	.macro	pgtbl, rd, phys

	add	\rd, \phys, #TEXT_OFFSET

	sub	\rd, \rd, #PG_DIR_SIZE

	.endm



/*

 * Kernel startup entry point.

 * ---------------------------
@@ -74,6 +66,9 @@ 
	.arm



	__HEAD

	.globl	swapper_pg_dir

	.equ	swapper_pg_dir, . - PG_DIR_SIZE



ENTRY(stext)

 ARM_BE8(setend	be )			@ ensure we are in BE8 mode
@@ -169,7 +164,7 @@ ENDPROC(stext) 
 *  r4 = physical page table address

 */

__create_page_tables:

	pgtbl	r4, r8				@ page table address

	adr_l	r4, swapper_pg_dir		@ page table address



	/*

	 * Clear the swapper page table