From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755200AbaIOT11 (ORCPT ); Mon, 15 Sep 2014 15:27:27 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:54700 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755024AbaIOT1F (ORCPT ); Mon, 15 Sep 2014 15:27:05 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alex Smith , linux-mips@linux-mips.org, Ralf Baechle Subject: [PATCH 3.16 064/158] MIPS: ptrace: Avoid smp_processor_id() when retrieving FPU IR Date: Mon, 15 Sep 2014 12:25:03 -0700 Message-Id: <20140915192544.816172080@linuxfoundation.org> X-Mailer: git-send-email 2.1.0 In-Reply-To: <20140915192542.872134685@linuxfoundation.org> References: <20140915192542.872134685@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: Alex Smith commit 656ff9bef08c19a6471b49528dacb4cbbeb1e537 upstream. Whenever ptrace attempts to retrieve the FPU implementation register it accesses it through current_cpu_data, which calls smp_processor_id(). Since the code may execute with preemption enabled, this can trigger a warning. Fix this by using boot_cpu_data to get the IR instead. Signed-off-by: Alex Smith Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7449/ Signed-off-by: Ralf Baechle Signed-off-by: Greg Kroah-Hartman --- arch/mips/kernel/ptrace.c | 4 ++-- arch/mips/kernel/ptrace32.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -129,7 +129,7 @@ int ptrace_getfpregs(struct task_struct } __put_user(child->thread.fpu.fcr31, data + 64); - __put_user(current_cpu_data.fpu_id, data + 65); + __put_user(boot_cpu_data.fpu_id, data + 65); return 0; } @@ -611,7 +611,7 @@ long arch_ptrace(struct task_struct *chi break; case FPC_EIR: /* implementation / version register */ - tmp = current_cpu_data.fpu_id; + tmp = boot_cpu_data.fpu_id; break; case DSP_BASE ... DSP_BASE + 5: { dspreg_t *dregs; --- a/arch/mips/kernel/ptrace32.c +++ b/arch/mips/kernel/ptrace32.c @@ -129,7 +129,7 @@ long compat_arch_ptrace(struct task_stru break; case FPC_EIR: /* implementation / version register */ - tmp = current_cpu_data.fpu_id; + tmp = boot_cpu_data.fpu_id; break; case DSP_BASE ... DSP_BASE + 5: { dspreg_t *dregs;