From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:50545 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161287AbcFCVjA (ORCPT ); Fri, 3 Jun 2016 17:39:00 -0400 From: Sasha Levin To: stable@vger.kernel.org, stable-commits@vger.kernel.org Cc: "Maciej W. Rozycki" , linux-mips@linux-mips.org, Ralf Baechle , Sasha Levin Subject: [added to the 4.1 stable tree] MIPS: ptrace: Fix FP context restoration FCSR regression Date: Fri, 3 Jun 2016 17:36:29 -0400 Message-Id: <1464989831-16666-94-git-send-email-sasha.levin@oracle.com> In-Reply-To: <1464989831-16666-1-git-send-email-sasha.levin@oracle.com> References: <1464989831-16666-1-git-send-email-sasha.levin@oracle.com> Sender: stable-owner@vger.kernel.org List-ID: From: "Maciej W. Rozycki" This patch has been added to the 4.1 stable tree. If you have any objections, please let us know. =============== [ Upstream commit 4249548454f7ba4581aeee26bd83f42b48a14d15 ] Fix a floating-point context restoration regression introduced with commit 9b26616c8d9d ("MIPS: Respect the ISA level in FCSR handling") that causes a Floating Point exception and consequently a kernel oops with hard float configurations when one or more FCSR Enable and their corresponding Cause bits are set both at a time via a ptrace(2) call. To do so reinstate Cause bit masking originally introduced with commit b1442d39fac2 ("MIPS: Prevent user from setting FCSR cause bits") to address this exact problem and then inadvertently removed from the PTRACE_SETFPREGS request with the commit referred above. Signed-off-by: Maciej W. Rozycki Cc: stable@vger.kernel.org # v4.0+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13238/ Signed-off-by: Ralf Baechle Signed-off-by: Sasha Levin --- arch/mips/kernel/ptrace.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c index e933a30..d56642a 100644 --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -175,6 +175,7 @@ int ptrace_setfpregs(struct task_struct *child, __u32 __user *data) } __get_user(value, data + 64); + value &= ~FPU_CSR_ALL_X; fcr31 = child->thread.fpu.fcr31; mask = boot_cpu_data.fpu_msk31; child->thread.fpu.fcr31 = (value & ~mask) | (fcr31 & mask); -- 2.5.0