From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965734AbeEYJzm (ORCPT ); Fri, 25 May 2018 05:55:42 -0400 Received: from foss.arm.com ([217.140.101.70]:57490 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965963AbeEYJuS (ORCPT ); Fri, 25 May 2018 05:50:18 -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 09/26] arm64: Use daifflag_restore after bp_hardening Date: Fri, 25 May 2018 10:49:15 +0100 Message-Id: <1527241772-48007-10-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 For EL0 entries requiring bp_hardening, daif status is kept at DAIF_PROCCTX_NOIRQ until after hardening has been done. Then interrupts are enabled through local_irq_enable(). Before using local_irq_* functions, daifflags should be properly restored to a state where IRQs are enabled. Enable IRQs by restoring DAIF_PROCCTX state after bp hardening. Signed-off-by: Julien Thierry Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: James Morse --- arch/arm64/mm/fault.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) Note: This doesn't introduce a real change in behaviour, but once PMR is used for interrupt masking, PSR.I bit needs to be cleared and local_irq_enable won't do that anymore. diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 4165485..7a18634 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include #include @@ -712,7 +713,7 @@ asmlinkage void __exception do_el0_ia_bp_hardening(unsigned long addr, if (addr > TASK_SIZE) arm64_apply_bp_hardening(); - local_irq_enable(); + local_daif_restore(DAIF_PROCCTX); do_mem_abort(addr, esr, regs); } @@ -726,7 +727,7 @@ asmlinkage void __exception do_sp_pc_abort(unsigned long addr, if (user_mode(regs)) { if (instruction_pointer(regs) > TASK_SIZE) arm64_apply_bp_hardening(); - local_irq_enable(); + local_daif_restore(DAIF_PROCCTX); } info.si_signo = SIGBUS; -- 1.9.1