Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933570AbaJDAYx (ORCPT ); Fri, 3 Oct 2014 20:24:53 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:45328 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755223AbaJCVnF (ORCPT ); Fri, 3 Oct 2014 17:43:05 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Joachim Eastwood , Nathan Lynch , Russell King Subject: [PATCH 3.16 191/357] ARM: 8178/1: fix set_tls for !CONFIG_KUSER_HELPERS Date: Fri, 3 Oct 2014 14:29:37 -0700 Message-Id: <20141003212939.205669548@linuxfoundation.org> X-Mailer: git-send-email 2.1.2 In-Reply-To: <20141003212933.458851516@linuxfoundation.org> References: <20141003212933.458851516@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nathan Lynch commit 9cc6d9e5daaa147a9a3e31557efcb331989e77be upstream. Joachim Eastwood reports that commit fbfb872f5f41 "ARM: 8148/1: flush TLS and thumbee register state during exec" causes a boot-time crash on a Cortex-M4 nommu system: Freeing unused kernel memory: 68K (281e5000 - 281f6000) Unhandled exception: IPSR = 00000005 LR = fffffff1 CPU: 0 PID: 1 Comm: swapper Not tainted 3.17.0-rc6-00313-gd2205fa30aa7 #191 task: 29834000 ti: 29832000 task.ti: 29832000 PC is at flush_thread+0x2e/0x40 LR is at flush_thread+0x21/0x40 pc : [<2800954a>] lr : [<2800953d>] psr: 4100000b sp : 29833d60 ip : 00000000 fp : 00000001 r10: 00003cf8 r9 : 29b1f000 r8 : 00000000 r7 : 29b0bc00 r6 : 29834000 r5 : 29832000 r4 : 29832000 r3 : ffff0ff0 r2 : 29832000 r1 : 00000000 r0 : 282121f0 xPSR: 4100000b CPU: 0 PID: 1 Comm: swapper Not tainted 3.17.0-rc6-00313-gd2205fa30aa7 #191 [<2800afa5>] (unwind_backtrace) from [<2800a327>] (show_stack+0xb/0xc) [<2800a327>] (show_stack) from [<2800a963>] (__invalid_entry+0x4b/0x4c) The problem is that set_tls is attempting to clear the TLS location in the kernel-user helper page, which isn't set up on V7M. Fix this by guarding the write to the kuser helper page with a CONFIG_KUSER_HELPERS ifdef. Fixes: fbfb872f5f41 ARM: 8148/1: flush TLS and thumbee register state during exec Reported-by: Joachim Eastwood Tested-by: Joachim Eastwood Signed-off-by: Nathan Lynch Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman --- arch/arm/include/asm/tls.h | 2 ++ 1 file changed, 2 insertions(+) --- a/arch/arm/include/asm/tls.h +++ b/arch/arm/include/asm/tls.h @@ -81,6 +81,7 @@ static inline void set_tls(unsigned long asm("mcr p15, 0, %0, c13, c0, 3" : : "r" (val)); } else { +#ifdef CONFIG_KUSER_HELPERS /* * User space must never try to access this * directly. Expect your app to break @@ -89,6 +90,7 @@ static inline void set_tls(unsigned long * entry-armv.S for details) */ *((unsigned int *)0xffff0ff0) = val; +#endif } } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/