From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:48459 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932761AbcIENzM (ORCPT ); Mon, 5 Sep 2016 09:55:12 -0400 Subject: Patch "arm64: kernel: Fix unmasked debug exceptions when restoring mdscr_el1" has been added to the 4.7-stable tree To: james.morse@arm.com, catalin.marinas@arm.com, gregkh@linuxfoundation.org, lorenzo.pieralisi@arm.com, will.deacon@arm.com Cc: , From: Date: Mon, 05 Sep 2016 15:55:05 +0200 Message-ID: <1473083705197153@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 arm64: kernel: Fix unmasked debug exceptions when restoring mdscr_el1 to the 4.7-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: arm64-kernel-fix-unmasked-debug-exceptions-when-restoring-mdscr_el1.patch and it can be found in the queue-4.7 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 744c6c37cc18705d19e179622f927f5b781fe9cc Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 26 Aug 2016 16:03:42 +0100 Subject: arm64: kernel: Fix unmasked debug exceptions when restoring mdscr_el1 From: James Morse commit 744c6c37cc18705d19e179622f927f5b781fe9cc upstream. Changes to make the resume from cpu_suspend() code behave more like secondary boot caused debug exceptions to be unmasked early by __cpu_setup(). We then go on to restore mdscr_el1 in cpu_do_resume(), potentially taking break or watch points based on uninitialised registers. Mask debug exceptions in cpu_do_resume(), which is specific to resume from cpu_suspend(). Debug exceptions will be restored to their original state by local_dbg_restore() in cpu_suspend(), which runs after hw_breakpoint_restore() has re-initialised the other registers. Reported-by: Lorenzo Pieralisi Fixes: cabe1c81ea5b ("arm64: Change cpu_resume() to enable mmu early then access sleep_sp by va") Signed-off-by: James Morse Acked-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman --- arch/arm64/mm/proc.S | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -100,7 +100,16 @@ ENTRY(cpu_do_resume) msr tcr_el1, x8 msr vbar_el1, x9 + + /* + * __cpu_setup() cleared MDSCR_EL1.MDE and friends, before unmasking + * debug exceptions. By restoring MDSCR_EL1 here, we may take a debug + * exception. Mask them until local_dbg_restore() in cpu_suspend() + * resets them. + */ + disable_dbg msr mdscr_el1, x10 + msr sctlr_el1, x12 /* * Restore oslsr_el1 by writing oslar_el1 Patches currently in stable-queue which might be from james.morse@arm.com are queue-4.7/arm64-kernel-fix-unmasked-debug-exceptions-when-restoring-mdscr_el1.patch