From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759797Ab3LBVWm (ORCPT ); Mon, 2 Dec 2013 16:22:42 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:38402 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752983Ab3LBTMl (ORCPT ); Mon, 2 Dec 2013 14:12:41 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Will Deacon , Catalin Marinas , Marc Zyngier , Russell King Subject: [PATCH 3.10 004/173] ARM: 7876/1: clear Thumb-2 IT state on exception handling Date: Mon, 2 Dec 2013 11:09:47 -0800 Message-Id: <20131202191143.466897498@linuxfoundation.org> X-Mailer: git-send-email 1.8.4.3.gca3854a In-Reply-To: <20131202191142.873808297@linuxfoundation.org> References: <20131202191142.873808297@linuxfoundation.org> User-Agent: quilt/0.60-8.1.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marc Zyngier commit e16b31bf47738f4498d7ce632e12d7d2a6a2492a upstream. The exception handling code fails to clear the IT state, potentially leading to incorrect execution of the fixup if the size of the IT block is more than one. Let fixup_exception do the IT sanitizing if a fixup has been found, and restore CPSR from the stack when returning from a data abort. Cc: Will Deacon Reviewed-by: Catalin Marinas Signed-off-by: Marc Zyngier Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman --- arch/arm/kernel/entry-armv.S | 1 + arch/arm/mm/extable.c | 7 ++++++- 2 files changed, 7 insertions(+), 1 deletion(-) --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -192,6 +192,7 @@ __dabt_svc: svc_entry mov r2, sp dabt_helper + THUMB( ldr r5, [sp, #S_PSR] ) @ potentially updated CPSR svc_exit r5 @ return from exception UNWIND(.fnend ) ENDPROC(__dabt_svc) --- a/arch/arm/mm/extable.c +++ b/arch/arm/mm/extable.c @@ -9,8 +9,13 @@ int fixup_exception(struct pt_regs *regs const struct exception_table_entry *fixup; fixup = search_exception_tables(instruction_pointer(regs)); - if (fixup) + if (fixup) { regs->ARM_pc = fixup->fixup; +#ifdef CONFIG_THUMB2_KERNEL + /* Clear the IT state to avoid nasty surprises in the fixup */ + regs->ARM_cpsr &= ~PSR_IT_MASK; +#endif + } return fixup != NULL; }