From patchwork Wed Mar 2 02:47:59 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "majun \(F\)" X-Patchwork-Id: 63364 Delivered-To: patch@linaro.org Received: by 10.112.199.169 with SMTP id jl9csp2157974lbc; Tue, 1 Mar 2016 18:50:22 -0800 (PST) X-Received: by 10.98.0.71 with SMTP id 68mr35188472pfa.156.1456887022635; Tue, 01 Mar 2016 18:50:22 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id zq10si54532602pab.11.2016.03.01.18.50.22; Tue, 01 Mar 2016 18:50:22 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755850AbcCBCuU (ORCPT + 30 others); Tue, 1 Mar 2016 21:50:20 -0500 Received: from szxga03-in.huawei.com ([119.145.14.66]:55586 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752260AbcCBCuS (ORCPT ); Tue, 1 Mar 2016 21:50:18 -0500 Received: from 172.24.1.51 (EHLO szxeml430-hub.china.huawei.com) ([172.24.1.51]) by szxrg03-dlp.huawei.com (MOS 4.4.3-GA FastPath queued) with ESMTP id BXA74206; Wed, 02 Mar 2016 10:48:11 +0800 (CST) Received: from localhost (10.177.235.245) by szxeml430-hub.china.huawei.com (10.82.67.185) with Microsoft SMTP Server id 14.3.235.1; Wed, 2 Mar 2016 10:48:03 +0800 From: MaJun To: , , , , , , , , , , Subject: [PATCH] Change the spin_lock/unlock_irq interface in proc_alloc_inum() function Date: Wed, 2 Mar 2016 10:47:59 +0800 Message-ID: <1456886879-28128-1-git-send-email-majun258@huawei.com> X-Mailer: git-send-email 1.9.5.msysgit.1 MIME-Version: 1.0 X-Originating-IP: [10.177.235.245] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A090201.56D65470.0072, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: e5455d5ecedcfff138d64c06edda8321 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ma Jun The spin_lock/unlock_irq interface is not safe when this function is called at some case which need irq disabled. For example: spin_lock_irqsave() | request_irq() --> proc_alloc_inum() | spin_unlock_irqrestore() Reported-by: Fan Jinke Signed-off-by: Ma Jun --- fs/proc/generic.c | 9 +++++---- 1 files changed, 5 insertions(+), 4 deletions(-) -- 1.7.1 diff --git a/fs/proc/generic.c b/fs/proc/generic.c index ff3ffc7..4fc1502 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -191,23 +191,24 @@ int proc_alloc_inum(unsigned int *inum) { unsigned int i; int error; + unsigned long flags; retry: if (!ida_pre_get(&proc_inum_ida, GFP_KERNEL)) return -ENOMEM; - spin_lock_irq(&proc_inum_lock); + spin_lock_irqsave(&proc_inum_lock, flags); error = ida_get_new(&proc_inum_ida, &i); - spin_unlock_irq(&proc_inum_lock); + spin_unlock_irqrestore(&proc_inum_lock, flags); if (error == -EAGAIN) goto retry; else if (error) return error; if (i > UINT_MAX - PROC_DYNAMIC_FIRST) { - spin_lock_irq(&proc_inum_lock); + spin_lock_irqsave(&proc_inum_lock, flags); ida_remove(&proc_inum_ida, i); - spin_unlock_irq(&proc_inum_lock); + spin_unlock_irqrestore(&proc_inum_lock, flags); return -ENOSPC; } *inum = PROC_DYNAMIC_FIRST + i;