From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:40236 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753187AbdA3NfN (ORCPT ); Mon, 30 Jan 2017 08:35:13 -0500 Subject: Patch "ARC: [arcompact] handle unaligned access delay slot corner case" has been added to the 4.4-stable tree To: vgupta@synopsys.com, gregkh@linuxfoundation.org Cc: , From: Date: Mon, 30 Jan 2017 14:33:03 +0100 Message-ID: <1485783183110112@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled ARC: [arcompact] handle unaligned access delay slot corner case to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arc-handle-unaligned-access-delay-slot-corner-case.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 9aed02feae57bf7a40cb04ea0e3017cb7a998db4 Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Fri, 27 Jan 2017 10:45:27 -0800 Subject: ARC: [arcompact] handle unaligned access delay slot corner case From: Vineet Gupta commit 9aed02feae57bf7a40cb04ea0e3017cb7a998db4 upstream. After emulating an unaligned access in delay slot of a branch, we pretend as the delay slot never happened - so return back to actual branch target (or next PC if branch was not taken). Curently we did this by handling STATUS32.DE, we also need to clear the BTA.T bit, which is disregarded when returning from original misaligned exception, but could cause weirdness if it took the interrupt return path (in case interrupt was acive too) One ARC700 customer ran into this when enabling unaligned access fixup for kernel mode accesses as well Signed-off-by: Vineet Gupta Signed-off-by: Greg Kroah-Hartman --- arch/arc/kernel/unaligned.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/arc/kernel/unaligned.c +++ b/arch/arc/kernel/unaligned.c @@ -241,8 +241,9 @@ int misaligned_fixup(unsigned long addre if (state.fault) goto fault; + /* clear any remanants of delay slot */ if (delay_mode(regs)) { - regs->ret = regs->bta; + regs->ret = regs->bta ~1U; regs->status32 &= ~STATUS_DE_MASK; } else { regs->ret += state.instr_len; Patches currently in stable-queue which might be from vgupta@synopsys.com are queue-4.4/arc-udelay-fix-inline-assembler-by-adding-lp_count-to-clobber-list.patch queue-4.4/arc-handle-unaligned-access-delay-slot-corner-case.patch