From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: [PATCH v9 09/13] arm64: BTI: Reset BTYPE when skipping emulated instructions Date: Wed, 11 Mar 2020 19:26:04 +0000 Message-ID: <20200311192608.40095-10-broonie@kernel.org> References: <20200311192608.40095-1-broonie@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200311192608.40095-1-broonie@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Catalin Marinas , Will Deacon Cc: Alexander Viro , Paul Elliott , Peter Zijlstra , Yu-cheng Yu , Amit Kachhap , Vincenzo Frascino , Marc Zyngier , Eugene Syromiatnikov , Szabolcs Nagy , "H . J . Lu " , Andrew Jones , Kees Cook , Arnd Bergmann , Jann Horn , Richard Henderson , =?UTF-8?q?Kristina=20Mart=C5=A1enko?= , Thomas Gleixner , Florian Weimer , Sudakshina Das , linux-a List-Id: linux-arch.vger.kernel.org From: Dave Martin Since normal execution of any non-branch instruction resets the PSTATE BTYPE field to 0, so do the same thing when emulating a trapped instruction. Branches don't trap directly, so we should never need to assign a non-zero value to BTYPE here. Signed-off-by: Dave Martin Signed-off-by: Mark Brown --- arch/arm64/kernel/traps.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 3c07a7074145..52ed261e7739 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -335,6 +335,8 @@ void arm64_skip_faulting_instruction(struct pt_regs *regs, unsigned long size) if (compat_user_mode(regs)) advance_itstate(regs); + else + regs->pstate &= ~PSR_BTYPE_MASK; } static LIST_HEAD(undef_hook); -- 2.20.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from foss.arm.com ([217.140.110.172]:54374 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731317AbgCKTdT (ORCPT ); Wed, 11 Mar 2020 15:33:19 -0400 From: Mark Brown Subject: [PATCH v9 09/13] arm64: BTI: Reset BTYPE when skipping emulated instructions Date: Wed, 11 Mar 2020 19:26:04 +0000 Message-ID: <20200311192608.40095-10-broonie@kernel.org> In-Reply-To: <20200311192608.40095-1-broonie@kernel.org> References: <20200311192608.40095-1-broonie@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Catalin Marinas , Will Deacon Cc: Alexander Viro , Paul Elliott , Peter Zijlstra , Yu-cheng Yu , Amit Kachhap , Vincenzo Frascino , Marc Zyngier , Eugene Syromiatnikov , Szabolcs Nagy , "H . J . Lu " , Andrew Jones , Kees Cook , Arnd Bergmann , Jann Horn , Richard Henderson , =?UTF-8?q?Kristina=20Mart=C5=A1enko?= , Thomas Gleixner , Florian Weimer , Sudakshina Das , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org, Dave Martin , Mark Brown Message-ID: <20200311192604.kUIJOQ8VkZ3MFmRXzJExQxik2PU7RbXL7VOnVtuAjnM@z> From: Dave Martin Since normal execution of any non-branch instruction resets the PSTATE BTYPE field to 0, so do the same thing when emulating a trapped instruction. Branches don't trap directly, so we should never need to assign a non-zero value to BTYPE here. Signed-off-by: Dave Martin Signed-off-by: Mark Brown --- arch/arm64/kernel/traps.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 3c07a7074145..52ed261e7739 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -335,6 +335,8 @@ void arm64_skip_faulting_instruction(struct pt_regs *regs, unsigned long size) if (compat_user_mode(regs)) advance_itstate(regs); + else + regs->pstate &= ~PSR_BTYPE_MASK; } static LIST_HEAD(undef_hook); -- 2.20.1