From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6BBA5C0044C for ; Wed, 31 Oct 2018 23:08:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 27AF020821 for ; Wed, 31 Oct 2018 23:08:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Dz26IKTn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 27AF020821 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730065AbeKAIIx (ORCPT ); Thu, 1 Nov 2018 04:08:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:58232 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730030AbeKAIIw (ORCPT ); Thu, 1 Nov 2018 04:08:52 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7AB0B2084A; Wed, 31 Oct 2018 23:08:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541027321; bh=x6HF4QIL5OlTuHXmztarRGF4czZrSYY4uhoUeERyU+Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Dz26IKTnKEg/pFuqSn2qmiCdEKg1O191U9Q1u7nkm/Q6V+EBioM/Lk0WHrdz5aAel Sz58vsUNN0+XlphDYYUEpvczdV6cwHsqNMQ879sPo6NqAhMRCaRdvLRGXmIpE1xm8T pr9UQSOPnrKAosZ9DNTu+YlyLoQHzbqWQCkD6BAo= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Will Deacon , Catalin Marinas , Sasha Levin Subject: [PATCH AUTOSEL 4.18 051/126] arm64: entry: Allow handling of undefined instructions from EL1 Date: Wed, 31 Oct 2018 19:06:39 -0400 Message-Id: <20181031230754.29029-51-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181031230754.29029-1-sashal@kernel.org> References: <20181031230754.29029-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Will Deacon [ Upstream commit 0bf0f444b2c49241b2b39aa3cf210d7c95ef6c34 ] Rather than panic() when taking an undefined instruction exception from EL1, allow a hook to be registered in case we want to emulate the instruction, like we will for the SSBS PSTATE manipulation instructions. Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin --- arch/arm64/kernel/entry.S | 2 +- arch/arm64/kernel/traps.c | 11 +++++++---- 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 28ad8799406f..b0db91eefbde 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -599,7 +599,7 @@ el1_undef: inherit_daif pstate=x23, tmp=x2 mov x0, sp bl do_undefinstr - ASM_BUG() + kernel_exit 1 el1_dbg: /* * Debug exception handling diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index d399d459397b..9fa3d69cceaa 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -310,10 +310,12 @@ static int call_undef_hook(struct pt_regs *regs) int (*fn)(struct pt_regs *regs, u32 instr) = NULL; void __user *pc = (void __user *)instruction_pointer(regs); - if (!user_mode(regs)) - return 1; - - if (compat_thumb_mode(regs)) { + if (!user_mode(regs)) { + __le32 instr_le; + if (probe_kernel_address((__force __le32 *)pc, instr_le)) + goto exit; + instr = le32_to_cpu(instr_le); + } else if (compat_thumb_mode(regs)) { /* 16-bit Thumb instruction */ __le16 instr_le; if (get_user(instr_le, (__le16 __user *)pc)) @@ -407,6 +409,7 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs) return; force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc); + BUG_ON(!user_mode(regs)); } void cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused) -- 2.17.1