[PATCH v2 05/29] ARM: head-common.S: use PC-relative insn sequence for idmap creation
From: Nicolas Pitre <hidden>
Date: 2017-09-04 16:08:25
On Sun, 3 Sep 2017, Ard Biesheuvel wrote:
Replace the open coded PC relative offset calculations involving __turn_mmu_on and __turn_mmu_on_end with a pair of adr_l invocations. This ensures these quantities are invariant under runtime relocation. Cc: Russell King <linux@armlinux.org.uk> Signed-off-by: Ard Biesheuvel <redacted>
Acked-by: Nicolas Pitre <redacted>
quoted hunk ↗ jump to hunk
--- arch/arm/kernel/head.S | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-)diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 04286fd9e09c..0a98aec0e39d 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S@@ -227,11 +227,8 @@ __create_page_tables: * Create identity mapping to cater for __enable_mmu. * This identity mapping will be removed by paging_init(). */ - adr r0, __turn_mmu_on_loc - ldmia r0, {r3, r5, r6} - sub r0, r0, r3 @ virt->phys offset - add r5, r5, r0 @ phys __turn_mmu_on - add r6, r6, r0 @ phys __turn_mmu_on_end + adr_l r5, __turn_mmu_on @ _pa(__turn_mmu_on) + adr_l r6, __turn_mmu_on_end @ _pa(__turn_mmu_on_end) mov r5, r5, lsr #SECTION_SHIFT mov r6, r6, lsr #SECTION_SHIFT@@ -354,11 +351,6 @@ __create_page_tables: ret lr ENDPROC(__create_page_tables) .ltorg - .align -__turn_mmu_on_loc: - .long . - .long __turn_mmu_on - .long __turn_mmu_on_end #if defined(CONFIG_SMP) .text-- 2.11.0