From patchwork Wed May 6 15:21:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 1237014 Return-Path: Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7972DC28CBC for ; Wed, 6 May 2020 15:21:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5312F2080D for ; Wed, 6 May 2020 15:21:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="KwX6/DXe" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729393AbgEFPVn (ORCPT ); Wed, 6 May 2020 11:21:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728821AbgEFPVn (ORCPT ); Wed, 6 May 2020 11:21:43 -0400 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E492AC061A0F for ; Wed, 6 May 2020 08:21:42 -0700 (PDT) Received: by mail-pj1-x1044.google.com with SMTP id y6so1061254pjc.4 for ; Wed, 06 May 2020 08:21:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=0GrsnLomqX5Yv3Tom3gIH7C/pCQ9LgRpoJPzGqJICzI=; b=KwX6/DXeNIsWsWlTUx2Lg/+bGBqtRwjeQ/X4DL9YgbOhA9d/lBCEIBp3b/fQ0YELmd mpAXQ5mJx36IzvHTcFqzSez/beBvtlCZ/ax0p/OKpzb4sYSZw6NEdMJcdB1uR5fwMtGX rlKVbttCR4kfIy8VdJPR8LCi8kESkUr09VpFw= 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=0GrsnLomqX5Yv3Tom3gIH7C/pCQ9LgRpoJPzGqJICzI=; b=hj2yk4iSPqQJ6ddhR3+gtW1zHQXXgyANrKKyotJ1lB32wWA7qi3k5ItPreAlJePPHQ 6zlhR0f8vQ5hI9Sjo1bcnHIl4AabulkJj08vtTQGKli04QlHNQ96o9yNutzMW1leP3uP ZxKYPLYE1jyCSCcw+KkANCfF7lDpDVTzOKU1wu15l/yClfHTZ8HOZpDgHmlsnPn2zaeu H8pMpwn42j34gRicDbZpWi5p6R7aMCNY/TvZt+We4tSq6lVq23tC5OAR+Sdr9v7cX5dh vlsDzixIk1dxWW8SJZPiCgMcj83R788ux+tbwJJtGwYsPu4AgF7Ybke3dTevyukFrsz6 +qrQ== X-Gm-Message-State: AGi0PuZKwXasLQ2ejgfFCltzQOwSUvuXlz9r4gr8DBbCsZu+Ok7dxTT7 rLk+6IsHeUIaxBi6rErycdU0UzUNn8c= X-Google-Smtp-Source: APiQypL1hTpo9FfJpbePD6l9WWohDd139O1SoPM9Xu90TAINWMR+B4rfGx5aoPGQ2ExTdUcYl6HEIQ== X-Received: by 2002:a17:90a:1941:: with SMTP id 1mr9515679pjh.65.1588778502424; Wed, 06 May 2020 08:21:42 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id a22sm2085212pfg.169.2020.05.06.08.21.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 May 2020 08:21:41 -0700 (PDT) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , Anton Vorontsov , Colin Cross , Tony Luck , Luis Henriques Subject: [PATCH 01/10] pstore: Drop useless try_module_get() for backend Date: Wed, 6 May 2020 08:21:05 -0700 Message-Id: <20200506152114.50375-2-keescook@chromium.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200506152114.50375-1-keescook@chromium.org> References: <20200506152114.50375-1-keescook@chromium.org> MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There is no reason to be doing a module get/put in pstore_register(), since the module calling pstore_register() cannot be unloaded since it hasn't finished its initialization. Remove it so there is no confusion about how registration ordering works. Signed-off-by: Kees Cook --- fs/pstore/platform.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 408277ee3cdb..44f8b9742263 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -555,8 +555,6 @@ static int pstore_write_user_compat(struct pstore_record *record, */ int pstore_register(struct pstore_info *psi) { - struct module *owner = psi->owner; - if (backend && strcmp(backend, psi->name)) { pr_warn("ignoring unexpected backend '%s'\n", psi->name); return -EPERM; @@ -591,10 +589,6 @@ int pstore_register(struct pstore_info *psi) sema_init(&psinfo->buf_lock, 1); spin_unlock(&pstore_lock); - if (owner && !try_module_get(owner)) { - psinfo = NULL; - return -EINVAL; - } if (psi->flags & PSTORE_FLAGS_DMESG) allocate_buf_for_compression(); @@ -626,8 +620,6 @@ int pstore_register(struct pstore_info *psi) pr_info("Registered %s as persistent store backend\n", psi->name); - module_put(owner); - return 0; } EXPORT_SYMBOL_GPL(pstore_register);