From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966023AbeEYJuW (ORCPT ); Fri, 25 May 2018 05:50:22 -0400 Received: from foss.arm.com ([217.140.101.70]:57502 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965485AbeEYJuU (ORCPT ); Fri, 25 May 2018 05:50:20 -0400 From: Julien Thierry To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, daniel.thompson@linaro.org, joel@joelfernandes.org, marc.zyngier@arm.com, mark.rutland@arm.com, christoffer.dall@arm.com, james.morse@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, Julien Thierry Subject: [PATCH v4 10/26] arm64: Delay daif masking for user return Date: Fri, 25 May 2018 10:49:16 +0100 Message-Id: <1527241772-48007-11-git-send-email-julien.thierry@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1527241772-48007-1-git-send-email-julien.thierry@arm.com> References: <1527241772-48007-1-git-send-email-julien.thierry@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Masking daif flags is done very early before returning to EL0. Only toggle the interrupt masking while in the vector entry and mask daif once in kernel_exit. Signed-off-by: Julien Thierry Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: James Morse --- arch/arm64/kernel/entry.S | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index ec2ee72..20252d5 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -240,9 +240,9 @@ alternative_else_nop_endif .endm .macro kernel_exit, el - .if \el != 0 disable_daif + .if \el != 0 /* Restore the task's original addr_limit. */ ldr x20, [sp, #S_ORIG_ADDR_LIMIT] str x20, [tsk, #TSK_TI_ADDR_LIMIT] @@ -872,7 +872,7 @@ ENDPROC(el0_error) * and this includes saving x0 back into the kernel stack. */ ret_fast_syscall: - disable_daif + disable_irq // disable interrupts str x0, [sp, #S_X0] // returned x0 ldr x1, [tsk, #TSK_TI_FLAGS] // re-check for syscall tracing and x2, x1, #_TIF_SYSCALL_WORK @@ -882,7 +882,7 @@ ret_fast_syscall: enable_step_tsk x1, x2 kernel_exit 0 ret_fast_syscall_trace: - enable_daif + enable_irq // enable interrupts b __sys_trace_return_skipped // we already saved x0 /* @@ -900,7 +900,7 @@ work_pending: * "slow" syscall return path. */ ret_to_user: - disable_daif + disable_irq // disable interrupts ldr x1, [tsk, #TSK_TI_FLAGS] and x2, x1, #_TIF_WORK_MASK cbnz x2, work_pending -- 1.9.1