From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S969251AbdEXI3A (ORCPT ); Wed, 24 May 2017 04:29:00 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:58101 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763122AbdEXI0g (ORCPT ); Wed, 24 May 2017 04:26:36 -0400 Message-Id: <20170524081549.354513406@linutronix.de> User-Agent: quilt/0.63-1 Date: Wed, 24 May 2017 10:15:39 +0200 From: Thomas Gleixner To: LKML Cc: Peter Zijlstra , Ingo Molnar , Steven Rostedt , Sebastian Siewior , Paul McKenney , Martin Schwidefsky , Heiko Carstens , linux-s390@vger.kernel.org Subject: [patch V3 28/32] s390: Prevent hotplug rwsem recursion References: <20170524081511.203800767@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=s390--Prevent-hotplug-rwsem-recursion.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The text patching functions which are invoked from jump_label and kprobes code are protected against cpu hotplug at the call sites. Use stop_machine_cpuslocked() to avoid recursion on the cpu hotplug rwsem. stop_machine_cpuslocked() contains a lockdep assertion to catch any unprotected callers. Signed-off-by: Thomas Gleixner Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: linux-s390@vger.kernel.org --- arch/s390/kernel/jump_label.c | 2 +- arch/s390/kernel/kprobes.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) --- a/arch/s390/kernel/jump_label.c +++ b/arch/s390/kernel/jump_label.c @@ -93,7 +93,7 @@ void arch_jump_label_transform(struct ju args.entry = entry; args.type = type; - stop_machine(__sm_arch_jump_label_transform, &args, NULL); + stop_machine_cpuslocked(__sm_arch_jump_label_transform, &args, NULL); } void arch_jump_label_transform_static(struct jump_entry *entry, --- a/arch/s390/kernel/kprobes.c +++ b/arch/s390/kernel/kprobes.c @@ -196,7 +196,7 @@ void arch_arm_kprobe(struct kprobe *p) { struct swap_insn_args args = {.p = p, .arm_kprobe = 1}; - stop_machine(swap_instruction, &args, NULL); + stop_machine_cpuslocked(swap_instruction, &args, NULL); } NOKPROBE_SYMBOL(arch_arm_kprobe); @@ -204,7 +204,7 @@ void arch_disarm_kprobe(struct kprobe *p { struct swap_insn_args args = {.p = p, .arm_kprobe = 0}; - stop_machine(swap_instruction, &args, NULL); + stop_machine_cpuslocked(swap_instruction, &args, NULL); } NOKPROBE_SYMBOL(arch_disarm_kprobe);