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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 ED46BC282DD for ; Wed, 8 Jan 2020 19:47:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CB4E720720 for ; Wed, 8 Jan 2020 19:47:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728096AbgAHTro (ORCPT ); Wed, 8 Jan 2020 14:47:44 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:43796 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730471AbgAHTqE (ORCPT ); Wed, 8 Jan 2020 14:46:04 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1ipHHE-0006p6-3X; Wed, 08 Jan 2020 19:46:00 +0000 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1ipHHC-007do9-TE; Wed, 08 Jan 2020 19:45:58 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Mark Rutland" , "Will Deacon" , "Catalin Marinas" Date: Wed, 08 Jan 2020 19:43:44 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 46/63] arm64: debug: Don't propagate UNKNOWN FAR into si_code for debug signals In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.81-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Will Deacon commit b9a4b9d084d978f80eb9210727c81804588b42ff upstream. FAR_EL1 is UNKNOWN for all debug exceptions other than those caused by taking a hardware watchpoint. Unfortunately, if a debug handler returns a non-zero value, then we will propagate the UNKNOWN FAR value to userspace via the si_addr field of the SIGTRAP siginfo_t. Instead, let's set si_addr to take on the PC of the faulting instruction, which we have available in the current pt_regs. Reviewed-by: Mark Rutland Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Ben Hutchings --- arch/arm64/mm/fault.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -512,11 +512,12 @@ void __init hook_debug_fault_code(int nr debug_fault_info[nr].name = name; } -asmlinkage int __exception do_debug_exception(unsigned long addr, +asmlinkage int __exception do_debug_exception(unsigned long addr_if_watchpoint, unsigned int esr, struct pt_regs *regs) { const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr); + unsigned long pc = instruction_pointer(regs); struct siginfo info; int rv; @@ -527,16 +528,16 @@ asmlinkage int __exception do_debug_exce if (interrupts_enabled(regs)) trace_hardirqs_off(); - if (!inf->fn(addr, esr, regs)) { + if (!inf->fn(addr_if_watchpoint, esr, regs)) { rv = 1; } else { pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n", - inf->name, esr, addr); + inf->name, esr, pc); info.si_signo = inf->sig; info.si_errno = 0; info.si_code = inf->code; - info.si_addr = (void __user *)addr; + info.si_addr = (void __user *)pc; arm64_notify_die("", regs, &info, 0); rv = 0; }