From: Ard Biesheuvel <ardb@kernel.org> mainline inclusion from mainline-5.11-rc1 commit 91580f0dbf24c6d616091526a900213bc7aa48fe category: feature issue: #I3ZXZF CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ------------------------------------------------- Replace the open coded PC relative offset calculations with adr_l and ldr_l invocations. This removes some open coded arithmetic involving virtual addresses, avoids literal pools on v7+, and slightly reduces the footprint of the code. Note that it also removes a stale comment about the contents of r6. Reviewed-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> (cherry picked from commit 91580f0dbf24c6d616091526a900213bc7aa48fe) Signed-off-by: Zhao Hongjiang <zhaohongjiang@huawei.com> Acked-by: Xie XiuQi <xiexiuqi@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> Signed-off-by: Yu Changchun <yuchangchun1@huawei.com> --- arch/arm/kernel/head.S | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-) diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 205881bb0919..fcd998ba9c9a 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -382,10 +382,8 @@ ENTRY(secondary_startup) /* * Use the page tables supplied from __cpu_up. */ - adr r4, __secondary_data - ldmia r4, {r5, r7, r12} @ address to jump to after - sub lr, r4, r5 @ mmu has been enabled - add r3, r7, lr + adr_l r3, secondary_data + mov_l r12, __secondary_switched ldrd r4, r5, [r3, #0] @ get secondary_data.pgdir ARM_BE8(eor r4, r4, r5) @ Swap r5 and r4 in BE: ARM_BE8(eor r5, r4, r5) @ it can be done in 3 steps @@ -400,22 +398,13 @@ ARM_BE8(eor r4, r4, r5) @ without using a temp reg. ENDPROC(secondary_startup) ENDPROC(secondary_startup_arm) - /* - * r6 = &secondary_data - */ ENTRY(__secondary_switched) - ldr sp, [r7, #12] @ get secondary_data.stack + ldr_l r7, secondary_data + 12 @ get secondary_data.stack + mov sp, r7 mov fp, #0 b secondary_start_kernel ENDPROC(__secondary_switched) - .align - - .type __secondary_data, %object -__secondary_data: - .long . - .long secondary_data - .long __secondary_switched #endif /* defined(CONFIG_SMP) */ -- 2.22.0