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 X-Spam-Level: X-Spam-Status: No, score=-17.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,HK_RANDOM_FROM, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 98C14C636C9 for ; Mon, 19 Jul 2021 03:25:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7919D60FD8 for ; Mon, 19 Jul 2021 03:25:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234388AbhGSD2e (ORCPT ); Sun, 18 Jul 2021 23:28:34 -0400 Received: from zg8tmty1ljiyny4xntqumjca.icoremail.net ([165.227.154.27]:49555 "HELO zg8tmty1ljiyny4xntqumjca.icoremail.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S234360AbhGSD2d (ORCPT ); Sun, 18 Jul 2021 23:28:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fudan.edu.cn; s=dkim; h=Received:From:To:Cc:Subject:Date: Message-Id; bh=Lcw52HFkeq79mvMCsUXc/S2q9uj7FXlOnZGYD5PeKys=; b=W QlLosoW25H2O8B0qQBk7NkSVUV40cyeeEgw8Fg2OFOfLFfJDJCyNy2AH65mSQpTb Nt6Mbuqm0zQ7+QpN2h9PYlkD3StJFeW1bD/NCvy5JcFsNEecmAw6Bdq7M0xAuLQV GL+w5bakBb46YZpG7oZLA/2vQx1UV3hEYwuka8ZPbc= Received: from localhost.localdomain (unknown [10.162.86.133]) by app1 (Coremail) with SMTP id XAUFCgDXt2iY8PRgLyaIAA--.722S3; Mon, 19 Jul 2021 11:25:12 +0800 (CST) From: Xiyu Yang To: Konrad Rzeszutek Wilk , =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= , Jens Axboe , xen-devel@lists.xenproject.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Cc: yuanxzhang@fudan.edu.cn, Xiyu Yang , Xin Tan Subject: [PATCH] xen-blkback: Convert from atomic_t to refcount_t on xen_blkif->refcnt Date: Mon, 19 Jul 2021 11:25:06 +0800 Message-Id: <1626665106-49298-1-git-send-email-xiyuyang19@fudan.edu.cn> X-Mailer: git-send-email 2.7.4 X-CM-TRANSID: XAUFCgDXt2iY8PRgLyaIAA--.722S3 X-Coremail-Antispam: 1UD129KBjvJXoW7Wry3tF17ZrWkWr4fGryfZwb_yoW8Zw4rpF s8Aa4xJFWUKF1xW3ZrAa1I9a43Ja98JFW5Way7C3s8Zr9xtwn2y3ZYkryagry8ZrZ3Jrn2 q3ZIgw18A3WxuF7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvS14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4U JVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gc CE3s1lnxkEFVAIw20F6cxK64vIFxWle2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xv F2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jrv_JF1lYx0Ex4A2jsIE14v26r1j6r 4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I 648v4I1lc2xSY4AK6svPMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI 8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AK xVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI 8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Gr0_Zr1lIxAIcVC2z280 aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43 ZEXa7VUbZmitUUUUU== X-CM-SenderInfo: irzsiiysuqikmy6i3vldqovvfxof0/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org refcount_t type and corresponding API can protect refcounters from accidental underflow and overflow and further use-after-free situations. Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan --- drivers/block/xen-blkback/common.h | 7 ++++--- drivers/block/xen-blkback/xenbus.c | 2 +- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h index bda5c815e441..d074cf41b4bc 100644 --- a/drivers/block/xen-blkback/common.h +++ b/drivers/block/xen-blkback/common.h @@ -27,6 +27,7 @@ #ifndef __XEN_BLKIF__BACKEND__COMMON_H__ #define __XEN_BLKIF__BACKEND__COMMON_H__ +#include #include #include #include @@ -306,7 +307,7 @@ struct xen_blkif { struct xen_vbd vbd; /* Back pointer to the backend_info. */ struct backend_info *be; - atomic_t refcnt; + refcount_t refcnt; /* for barrier (drain) requests */ struct completion drain_complete; atomic_t drain; @@ -359,10 +360,10 @@ struct pending_req { #define vbd_sz(_v) bdev_nr_sectors((_v)->bdev) -#define xen_blkif_get(_b) (atomic_inc(&(_b)->refcnt)) +#define xen_blkif_get(_b) (refcount_inc(&(_b)->refcnt)) #define xen_blkif_put(_b) \ do { \ - if (atomic_dec_and_test(&(_b)->refcnt)) \ + if (refcount_dec_and_test(&(_b)->refcnt)) \ schedule_work(&(_b)->free_work);\ } while (0) diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index 125b22205d38..b0bd5faa3865 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -168,7 +168,7 @@ static struct xen_blkif *xen_blkif_alloc(domid_t domid) return ERR_PTR(-ENOMEM); blkif->domid = domid; - atomic_set(&blkif->refcnt, 1); + refcount_set(&blkif->refcnt, 1); init_completion(&blkif->drain_complete); /* -- 2.7.4