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=-3.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 AAF12C46471 for ; Sun, 5 Aug 2018 20:08:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 62DF42156B for ; Sun, 5 Aug 2018 20:08:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="FB6FaXGf" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 62DF42156B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729325AbeHEWOV (ORCPT ); Sun, 5 Aug 2018 18:14:21 -0400 Received: from mail-pl0-f68.google.com ([209.85.160.68]:42322 "EHLO mail-pl0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729193AbeHEWOU (ORCPT ); Sun, 5 Aug 2018 18:14:20 -0400 Received: by mail-pl0-f68.google.com with SMTP id g6-v6so1154528plq.9 for ; Sun, 05 Aug 2018 13:08:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=wA/I74DwdG5/o2actje4g8J97nm7i9lFPMy6J5tsJ8E=; b=FB6FaXGfdbNqIsyQOsdJQ/WMvLJ8fOiRVXApOa+XuOLiE0vu/NMjx9UnKfobQYO+ip RxM3ih2Q3LzccoPJJBMfathTZUW+Z/plJEiZXm5GL6C50U/vcaIfCK32F/oS2rqBDlrl WNK796LLbYvAhns2qeWGauxXtOWUeMxqBe5YDr4h/FXFlDifukrZ3AT7TgmXbm5KHQfN N1M32+sn5wWVqsO165d9e2HPiDyW4P8cgVhYl0/yLWmU4+Ru70m9Mp9Rg5pUJkH61j/f RcdUvI99jVbPZV1pCws27eOsO6z+twUybj+fNAckjn9x3QdnRm6iM9cobXLpJcNzg3SR vLpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=wA/I74DwdG5/o2actje4g8J97nm7i9lFPMy6J5tsJ8E=; b=r3tSMzVSsXdbhKNKnHmsYkOdUhy/FcX5ywIlW+9Q+KCQn5mBfG9Hn2g3nEiJ+JNqze yi8lwBTaBxTGF/nx+jt6EWkR4GiZXapG3NuKElP1nZoIHodBXcUnuxv+cZjK0Bw2Xzwj sMFgSLJL+oqVJTQh4C2pjDXfKqXWW0XCLtWcI+YRmd2gCKw2u1vGRFxjNv1haU/Vp8lM NK7cS+d28caRxi20kLC3ol450b6RgXb27OeABXHW1LbGcQKbkEH2II2+G6/jEtgJgSFe jaXeS1PsKpd0gMkiBd8QC3XHWMr/iU/jrlqkK+uxEuPexygRdkvJc9lIao1N1mnd8cye Ju9A== X-Gm-Message-State: AOUpUlHtJIZjUjdIx/gdNsCa+P3FkM1YupuSb7Em6VxlgOooDkewUaf9 ppK/d4egfqdd/tvQFw1v9CQ= X-Google-Smtp-Source: AAOMgpdgTLF4/R7p8CLQ9ebChPLqLJcJKdxWI9S5py/lOPnY3WvO+wb3DEv1NcZ8FPconh2KBSQVVw== X-Received: by 2002:a17:902:8697:: with SMTP id g23-v6mr11440683plo.292.1533499715329; Sun, 05 Aug 2018 13:08:35 -0700 (PDT) Received: from toddpoynor2.mtv.corp.google.com ([2620:0:1000:3701:7d29:cd13:d903:7908]) by smtp.gmail.com with ESMTPSA id o72-v6sm15038227pfk.76.2018.08.05.13.08.34 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 05 Aug 2018 13:08:34 -0700 (PDT) From: Todd Poynor To: Rob Springer , John Joseph , Ben Chan , Greg Kroah-Hartman Cc: devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, Todd Poynor Subject: [PATCH 13/15] staging: gasket: core: protect against races during unregister Date: Sun, 5 Aug 2018 13:07:47 -0700 Message-Id: <20180805200749.116693-14-toddpoynor@gmail.com> X-Mailer: git-send-email 2.18.0.597.ga71716f1ad-goog In-Reply-To: <20180805200749.116693-1-toddpoynor@gmail.com> References: <20180805200749.116693-1-toddpoynor@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Todd Poynor Keep mutex held across the unregistration operation, until the driver_desc field of the global table is removed, to prevent a concurrent accessor from looking up the driver_desc while gasket_unregister_device() is in the processing of removing it. Reported-by: Guenter Roeck Signed-off-by: Todd Poynor --- drivers/staging/gasket/gasket_core.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/staging/gasket/gasket_core.c b/drivers/staging/gasket/gasket_core.c index ace92f107ed58..a6462b6d702f1 100644 --- a/drivers/staging/gasket/gasket_core.c +++ b/drivers/staging/gasket/gasket_core.c @@ -1765,9 +1765,9 @@ void gasket_unregister_device(const struct gasket_driver_desc *driver_desc) break; } } - mutex_unlock(&g_mutex); if (!internal_desc) { + mutex_unlock(&g_mutex); pr_err("request to unregister unknown desc: %s, %d:%d\n", driver_desc->name, driver_desc->major, driver_desc->minor); @@ -1780,7 +1780,6 @@ void gasket_unregister_device(const struct gasket_driver_desc *driver_desc) class_destroy(internal_desc->class); /* Finally, effectively "remove" the driver. */ - mutex_lock(&g_mutex); g_descs[desc_idx].driver_desc = NULL; mutex_unlock(&g_mutex); -- 2.18.0.597.ga71716f1ad-goog