From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765972AbdEXI0i (ORCPT ); Wed, 24 May 2017 04:26:38 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:58040 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1765480AbdEXI00 (ORCPT ); Wed, 24 May 2017 04:26:26 -0400 Message-Id: <20170524081549.197070135@linutronix.de> User-Agent: quilt/0.63-1 Date: Wed, 24 May 2017 10:15:37 +0200 From: Thomas Gleixner To: LKML Cc: Peter Zijlstra , Ingo Molnar , Steven Rostedt , Sebastian Siewior , Paul McKenney , Catalin Marinas , Will Deacon , Mark Rutland , linux-arm-kernel@lists.infradead.org Subject: [patch V3 26/32] arm64: Prevent cpu hotplug rwsem recursion References: <20170524081511.203800767@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=arm64--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: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org --- arch/arm64/include/asm/insn.h | 1 - arch/arm64/kernel/insn.c | 5 +++-- 2 files changed, 3 insertions(+), 3 deletions(-) --- a/arch/arm64/include/asm/insn.h +++ b/arch/arm64/include/asm/insn.h @@ -433,7 +433,6 @@ u32 aarch64_set_branch_offset(u32 insn, bool aarch64_insn_hotpatch_safe(u32 old_insn, u32 new_insn); int aarch64_insn_patch_text_nosync(void *addr, u32 insn); -int aarch64_insn_patch_text_sync(void *addrs[], u32 insns[], int cnt); int aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt); s32 aarch64_insn_adrp_get_offset(u32 insn); --- a/arch/arm64/kernel/insn.c +++ b/arch/arm64/kernel/insn.c @@ -255,6 +255,7 @@ static int __kprobes aarch64_insn_patch_ return ret; } +static int __kprobes aarch64_insn_patch_text_sync(void *addrs[], u32 insns[], int cnt) { struct aarch64_insn_patch patch = { @@ -267,8 +268,8 @@ int __kprobes aarch64_insn_patch_text_sy if (cnt <= 0) return -EINVAL; - return stop_machine(aarch64_insn_patch_text_cb, &patch, - cpu_online_mask); + return stop_machine_cpuslocked(aarch64_insn_patch_text_cb, &patch, + cpu_online_mask); } int __kprobes aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt)