From nobody Wed Apr 8 02:52:35 2026 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 772D3C32792 for ; Wed, 24 Aug 2022 03:51:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233882AbiHXDvN (ORCPT ); Tue, 23 Aug 2022 23:51:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60476 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234164AbiHXDvI (ORCPT ); Tue, 23 Aug 2022 23:51:08 -0400 Received: from mail-pj1-x102b.google.com (mail-pj1-x102b.google.com [IPv6:2607:f8b0:4864:20::102b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B05F41E3D0 for ; Tue, 23 Aug 2022 20:51:05 -0700 (PDT) Received: by mail-pj1-x102b.google.com with SMTP id t11-20020a17090a510b00b001fac77e9d1fso280634pjh.5 for ; Tue, 23 Aug 2022 20:51:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc; bh=hVbygpsX18bADu8621RDiTY25Ix7yxtXTuIImkqKqAc=; b=imJxJFMkD+pFI/m/eVMOuoWfkOen19J/ktKtwmDwT/PY6U1bYPSWCflbZVFU5jWkV2 pfQOzdoocVBRJb1gZMFSfQxlLoee6iCsXkcFja/ka+GlaPn29zI33jGlRMvu9YMTmDTP AAbB+NZhj1viQNfFLY56OwZGbE6QIPGg+J8QQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc; bh=hVbygpsX18bADu8621RDiTY25Ix7yxtXTuIImkqKqAc=; b=HMRn5WjA000fGOId86O8CtDBYqncqbANKUkhf4Nqitgw5NN0nil/JGXpBtkw10PGSJ YaOwoD962rxIleR/YM/H5d5ATjaTs5swhqVdYSGW2zjYjWhjmu7+XKNhCJZvXoBAaCOY L2xFVgFfNRH0MdwP+NeaQ4wMHVxGs8NFvdffPqSS2U4ZjunMrdumFZsYPlBP1Nl9HNKf nWpLk5l3EX2VZFXlLm+hUkGrsnpz0JU/JgKNdC0xCF03IsUmif4Ccs4CKnsA6VzaxiO0 1KQfBQPR1c75P+JTw/w0HiJTXoPJa94P+u1wGj1VoOUixNnj60xjE31XFgCv+ArbmQas Wj4g== X-Gm-Message-State: ACgBeo0e871EZVqt38FSnTXyCHj6mO2iFz812Dv2JRfTcGr0M8kOq+lR xsEScAa4sSsrxDAcj1YDYdRqNOHBV3jASQ== X-Google-Smtp-Source: AA6agR5+lKH6mqJCr0IR+RV7GQ3KgHD8KR0ilIw5+VWN6nDlIo/PEU275jXMmLB7C0ZQdPOcTB+70A== X-Received: by 2002:a17:90b:1d0b:b0:1f5:6554:d556 with SMTP id on11-20020a17090b1d0b00b001f56554d556mr6356470pjb.168.1661313065077; Tue, 23 Aug 2022 20:51:05 -0700 (PDT) Received: from tigerii.tok.corp.google.com ([2401:fa00:8f:203:969c:a365:dc63:66dc]) by smtp.gmail.com with ESMTPSA id nn18-20020a17090b38d200b001fa80cde150sm178343pjb.20.2022.08.23.20.51.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Aug 2022 20:51:04 -0700 (PDT) From: Sergey Senozhatsky To: Andrew Morton , Minchan Kim Cc: Nitin Gupta , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Sergey Senozhatsky Subject: [PATCH] block:zram: do not keep dangling zcomp pointer after zram reset Date: Wed, 24 Aug 2022 12:51:00 +0900 Message-Id: <20220824035100.971816-1-senozhatsky@chromium.org> X-Mailer: git-send-email 2.37.2.609.g9ff673ca1a-goog MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" We do all reset operations under write lock, so we don't need to save ->disksize and ->comp to stack variables. Another thing is that ->comp is freed during zram reset, but comp pointer is not NULL-ed, so zram keeps the freed pointer value. Signed-off-by: Sergey Senozhatsky --- drivers/block/zram/zram_drv.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 0c8c211f051f..4fc99c5667ef 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1721,9 +1721,6 @@ static int zram_rw_page(struct block_device *bdev, se= ctor_t sector, =20 static void zram_reset_device(struct zram *zram) { - struct zcomp *comp; - u64 disksize; - down_write(&zram->init_lock); =20 zram->limit_pages =3D 0; @@ -1733,17 +1730,15 @@ static void zram_reset_device(struct zram *zram) return; } =20 - comp =3D zram->comp; - disksize =3D zram->disksize; - zram->disksize =3D 0; - set_capacity_and_notify(zram->disk, 0); part_stat_set_all(zram->disk->part0, 0); =20 /* I/O operation under all of CPU are done so let's free */ - zram_meta_free(zram, disksize); + zram_meta_free(zram, zram->disksize); + zram->disksize =3D 0; memset(&zram->stats, 0, sizeof(zram->stats)); - zcomp_destroy(comp); + zcomp_destroy(zram->comp); + zram->comp =3D NULL; reset_bdev(zram); =20 up_write(&zram->init_lock); --=20 2.37.2.609.g9ff673ca1a-goog