From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754581AbdL1R0k (ORCPT ); Thu, 28 Dec 2017 12:26:40 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:58874 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754422AbdL1ROF (ORCPT ); Thu, 28 Dec 2017 12:14:05 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Fengguang Wu" , "Borislav Petkov" , "Robert Richter" , x86@kernel.org, "Thomas Gleixner" Date: Thu, 28 Dec 2017 17:05:44 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 175/204] x86/oprofile/ppro: Do not use __this_cpu*() in preemptible context In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.52-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Borislav Petkov commit a743bbeef27b9176987ec0cb7f906ab0ab52d1da upstream. The warning below says it all: BUG: using __this_cpu_read() in preemptible [00000000] code: swapper/0/1 caller is __this_cpu_preempt_check CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.0-rc8 #4 Call Trace: dump_stack check_preemption_disabled ? do_early_param __this_cpu_preempt_check arch_perfmon_init op_nmi_init ? alloc_pci_root_info oprofile_arch_init oprofile_init do_one_initcall ... These accessors should not have been used in the first place: it is PPro so no mixed silicon revisions and thus it can simply use boot_cpu_data. Reported-by: Fengguang Wu Tested-by: Fengguang Wu Fix-creation-mandated-by: Linus Torvalds Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Cc: Robert Richter Cc: x86@kernel.org Signed-off-by: Ben Hutchings --- arch/x86/oprofile/op_model_ppro.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/x86/oprofile/op_model_ppro.c +++ b/arch/x86/oprofile/op_model_ppro.c @@ -212,8 +212,8 @@ static void arch_perfmon_setup_counters( eax.full = cpuid_eax(0xa); /* Workaround for BIOS bugs in 6/15. Taken from perfmon2 */ - if (eax.split.version_id == 0 && __this_cpu_read(cpu_info.x86) == 6 && - __this_cpu_read(cpu_info.x86_model) == 15) { + if (eax.split.version_id == 0 && boot_cpu_data.x86 == 6 && + boot_cpu_data.x86_model == 15) { eax.split.version_id = 2; eax.split.num_counters = 2; eax.split.bit_width = 40;