From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753237AbeE3L2K (ORCPT ); Wed, 30 May 2018 07:28:10 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33275 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751651AbeE3LYB (ORCPT ); Wed, 30 May 2018 07:24:01 -0400 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, "Stefan Kristiansson" , "Jonas Bonn" , "Arnd Bergmann" , "Stafford Horne" , openrisc@lists.librecores.org, "Eric W. Biederman" Date: Wed, 30 May 2018 11:52:41 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 046/153] signal/openrisc: Fix do_unaligned_access to send the proper signal In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.102-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: "Eric W. Biederman" commit 500d58300571b6602341b041f97c082a461ef994 upstream. While reviewing the signal sending on openrisc the do_unaligned_access function stood out because it is obviously wrong. A comment about an si_code set above when actually si_code is never set. Leading to a random si_code being sent to userspace in the event of an unaligned access. Looking further SIGBUS BUS_ADRALN is the proper pair of signal and si_code to send for an unaligned access. That is what other architectures do and what is required by posix. Given that do_unaligned_access is broken in a way that no one can be relying on it on openrisc fix the code to just do the right thing. Fixes: 769a8a96229e ("OpenRISC: Traps") Cc: Jonas Bonn Cc: Stefan Kristiansson Cc: Stafford Horne Cc: Arnd Bergmann Cc: openrisc@lists.librecores.org Acked-by: Stafford Horne Signed-off-by: "Eric W. Biederman" Signed-off-by: Ben Hutchings --- arch/openrisc/kernel/traps.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) --- a/arch/openrisc/kernel/traps.c +++ b/arch/openrisc/kernel/traps.c @@ -313,12 +313,12 @@ asmlinkage void do_unaligned_access(stru siginfo_t info; if (user_mode(regs)) { - /* Send a SIGSEGV */ - info.si_signo = SIGSEGV; + /* Send a SIGBUS */ + info.si_signo = SIGBUS; info.si_errno = 0; - /* info.si_code has been set above */ - info.si_addr = (void *)address; - force_sig_info(SIGSEGV, &info, current); + info.si_code = BUS_ADRALN; + info.si_addr = (void __user *)address; + force_sig_info(SIGBUS, &info, current); } else { printk("KERNEL: Unaligned Access 0x%.8lx\n", address); show_registers(regs);