From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D7089C433F5 for ; Mon, 20 Dec 2021 15:05:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238644AbhLTPFj (ORCPT ); Mon, 20 Dec 2021 10:05:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239251AbhLTPD7 (ORCPT ); Mon, 20 Dec 2021 10:03:59 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E0D39C08E84A; Mon, 20 Dec 2021 06:52:24 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 803DC611B9; Mon, 20 Dec 2021 14:52:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 687A0C36AE9; Mon, 20 Dec 2021 14:52:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1640011944; bh=tjf3jWyhXK0F3lgb0w/NbcxSgn/y/h2Bj74LPNc8MPg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NzJNsKVwd8DBLRl9UhtDMSQiMogtuTPdYQMRWxMHUpfozzsOnvTHDxphJwX3V0jS+ KgPVgLLsnXiwlGdSLurd7FZEONmt85tAs5LrH+jcLzD7KXZIESpnvfHnopfeEMqQmP uqlv0ia466MwJaSsQ74aSu7V1rZvBcK5wNPb93Ps= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mark Rutland , Sven Schnelle , Heiko Carstens Subject: [PATCH 5.15 024/177] s390/entry: fix duplicate tracking of irq nesting level Date: Mon, 20 Dec 2021 15:32:54 +0100 Message-Id: <20211220143040.896251354@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211220143040.058287525@linuxfoundation.org> References: <20211220143040.058287525@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sven Schnelle commit c9b12b59e2ea4c3c7cedec7efb071b649652f3a9 upstream. In the current code, when exiting from idle, rcu_irq_enter() is called twice during irq entry: irq_entry_enter()-> rcu_irq_enter() irq_enter() -> rcu_irq_enter() This may lead to wrong results from rcu_is_cpu_rrupt_from_idle() because of a wrong dynticks nmi nesting count. Fix this by only calling irq_enter_rcu(). Cc: # 5.12+ Reported-by: Mark Rutland Fixes: 56e62a737028 ("s390: convert to generic entry") Signed-off-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Greg Kroah-Hartman --- arch/s390/kernel/irq.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/arch/s390/kernel/irq.c +++ b/arch/s390/kernel/irq.c @@ -138,7 +138,7 @@ void noinstr do_io_irq(struct pt_regs *r struct pt_regs *old_regs = set_irq_regs(regs); int from_idle; - irq_enter(); + irq_enter_rcu(); if (user_mode(regs)) update_timer_sys(); @@ -155,7 +155,8 @@ void noinstr do_io_irq(struct pt_regs *r do_irq_async(regs, IO_INTERRUPT); } while (MACHINE_IS_LPAR && irq_pending(regs)); - irq_exit(); + irq_exit_rcu(); + set_irq_regs(old_regs); irqentry_exit(regs, state); @@ -169,7 +170,7 @@ void noinstr do_ext_irq(struct pt_regs * struct pt_regs *old_regs = set_irq_regs(regs); int from_idle; - irq_enter(); + irq_enter_rcu(); if (user_mode(regs)) update_timer_sys(); @@ -184,7 +185,7 @@ void noinstr do_ext_irq(struct pt_regs * do_irq_async(regs, EXT_INTERRUPT); - irq_exit(); + irq_exit_rcu(); set_irq_regs(old_regs); irqentry_exit(regs, state);