From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ard Biesheuvel Date: Mon, 14 Aug 2017 13:54:01 +0100 Message-Id: <20170814125411.22604-21-ard.biesheuvel@linaro.org> In-Reply-To: <20170814125411.22604-1-ard.biesheuvel@linaro.org> References: <20170814125411.22604-1-ard.biesheuvel@linaro.org> Subject: [kernel-hardening] [PATCH 20/30] ARM: kernel: use PC relative symbol references in suspend/resume code To: kernel-hardening@lists.openwall.com Cc: linux-arm-kernel@lists.infradead.org, Ard Biesheuvel , Arnd Bergmann , Nicolas Pitre , Russell King , Kees Cook , Thomas Garnier , Marc Zyngier , Mark Rutland , Tony Lindgren , Matt Fleming , Dave Martin List-ID: Replace some unnecessary absolute references with relative ones. Also, to prepare for runtime relocation, which occurs with the caches on, defer taking the absolute address of cpu_resume_after_mmu() until after the MMU is enabled. Cc: Russell King Signed-off-by: Ard Biesheuvel --- arch/arm/kernel/sleep.S | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S index 3026b119d3ff..9efd1c7d3552 100644 --- a/arch/arm/kernel/sleep.S +++ b/arch/arm/kernel/sleep.S @@ -60,18 +60,17 @@ ENTRY(__cpu_suspend) stmfd sp!, {r4 - r11, lr} #ifdef MULTI_CPU - ldr r10, =processor - ldr r4, [r10, #CPU_SLEEP_SIZE] @ size of CPU sleep state + ldr_l r4, processor + CPU_SLEEP_SIZE @ size of CPU sleep state #else - ldr r4, =cpu_suspend_size + adr_l r4, cpu_suspend_size #endif mov r5, sp @ current virtual SP add r4, r4, #12 @ Space for pgd, virt sp, phys resume fn sub sp, sp, r4 @ allocate CPU state on stack - ldr r3, =sleep_save_sp + adr_l r3, sleep_save_sp stmfd sp!, {r0, r1} @ save suspend func arg and pointer ldr r3, [r3, #SLEEP_SAVE_SP_VIRT] - ALT_SMP(ldr r0, =mpidr_hash) + ALT_SMP(adr_l r0, mpidr_hash) ALT_UP_B(1f) /* This ldmia relies on the memory layout of the mpidr_hash struct */ ldmia r0, {r1, r6-r8} @ r1 = mpidr mask (r6,r7,r8) = l[0,1,2] shifts @@ -100,13 +99,13 @@ ENDPROC(cpu_suspend_abort) .align 5 .pushsection .idmap.text,"ax" ENTRY(cpu_resume_mmu) - ldr r3, =cpu_resume_after_mmu instr_sync mcr p15, 0, r0, c1, c0, 0 @ turn on MMU, I-cache, etc mrc p15, 0, r0, c0, c0, 0 @ read id reg instr_sync mov r0, r0 mov r0, r0 + ldr r3, =cpu_resume_after_mmu ret r3 @ jump to virtual address ENDPROC(cpu_resume_mmu) .popsection -- 2.11.0