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=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,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 41507CA9EAF for ; Thu, 24 Oct 2019 16:39:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 13A29205C9 for ; Thu, 24 Oct 2019 16:39:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="DQl9V900" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2503585AbfJXQiw (ORCPT ); Thu, 24 Oct 2019 12:38:52 -0400 Received: from mail-wm1-f65.google.com ([209.85.128.65]:38680 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2503545AbfJXQir (ORCPT ); Thu, 24 Oct 2019 12:38:47 -0400 Received: by mail-wm1-f65.google.com with SMTP id 3so3254029wmi.3 for ; Thu, 24 Oct 2019 09:38:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=+Uje5yZA2ldJsbsoiBPp+JyZjTmn5fr8PAwcjGY2GnI=; b=DQl9V900fqGUpTL6GCaKfkeZ3gpfIHFqAKSX3ufvAjrIcUCC99G8QrABRgrFAHr84f zXLGkBQbvxYo558DCuJqQRDDXaj2qphtEatUBS+Lk2L/kgUEZOlNLKkQr/2VGOUirh4E 6jKdZxmOXPYIkjq+XUBdV+4Kw/ot1PyjPtVGHPHjzWvr5e5pNz9JmDdPSIPFVB09IPWO J99BmaTltlCpMUovCATgjqDRfUheM9tsvnCGce4Ysz+isq5zOjxTekh7k4kElKxW1h0I wSMBV1bRCLq9eaApiDlolzZZeA1p6It53pyezLs2vAm0LSkxnBL7yVJGV/ov+1Xf6Njw Chtw== 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; bh=+Uje5yZA2ldJsbsoiBPp+JyZjTmn5fr8PAwcjGY2GnI=; b=gjkuulNg03UzZMx//iRvHYESdwVaMwsNbQZOPbY2gEnU0WbO8dsF4g8zxv68kCkTsk 8gSLOlpdXzRolJ0Ppt5YPyq4LTveev3IWBbQuwmmbIZmmf9XdB8BAkYWo1WZaqsVycn1 RZU9/vKUOVkNkjdhPcL9R2m4NTz3XJg7xQzC/zdNtgAOV2rHvSVMTaIgGKWNrZePtPYY LQ/hp055GVNLfM1XbkVpCeJWCR47RbA0F2sd4zcoaK4bCjPCYR5exIxpHJf6i5sSzJbJ II5pGn4xr4MkagZ3faum7aL+5CNwYmaIOcvrJBlbeQSZu6tdgUgxD+B0R7WtyCdeQkFu EeEg== X-Gm-Message-State: APjAAAXyJnJ7YNLBQ67SFlqydtQK3TeqKrFP6j3iqSyEhC96f60diIdb ufeD+u4XvL4l6IMLFZ3BiHTXUB3h8b8= X-Google-Smtp-Source: APXvYqxlMNsjCTwkEt0d7L6AsHU/jq7MCFgUCZONkNBta21bcHrPhdZtg5MDI/XxzWmIHo3m+xvqdw== X-Received: by 2002:a05:600c:143:: with SMTP id w3mr786098wmm.132.1571935124805; Thu, 24 Oct 2019 09:38:44 -0700 (PDT) Received: from localhost.localdomain ([95.149.164.99]) by smtp.gmail.com with ESMTPSA id 6sm3446175wmd.36.2019.10.24.09.38.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 24 Oct 2019 09:38:44 -0700 (PDT) From: Lee Jones To: daniel.thompson@linaro.org, arnd@arndb.de, broonie@kernel.org, linus.walleij@linaro.org Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, baohua@kernel.org, stephan@gerhold.net, Lee Jones Subject: [PATCH v3 08/10] mfd: mfd-core: Protect against NULL call-back function pointer Date: Thu, 24 Oct 2019 17:38:30 +0100 Message-Id: <20191024163832.31326-9-lee.jones@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191024163832.31326-1-lee.jones@linaro.org> References: <20191024163832.31326-1-lee.jones@linaro.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If a child device calls mfd_cell_{en,dis}able() without an appropriate call-back being set, we are likely to encounter a panic. Avoid this by adding suitable checking. Signed-off-by: Lee Jones Reviewed-by: Daniel Thompson --- drivers/mfd/mfd-core.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c index 8126665bb2d8..e38e411ca775 100644 --- a/drivers/mfd/mfd-core.c +++ b/drivers/mfd/mfd-core.c @@ -28,6 +28,11 @@ int mfd_cell_enable(struct platform_device *pdev) const struct mfd_cell *cell = mfd_get_cell(pdev); int err = 0; + if (!cell->enable) { + dev_dbg(&pdev->dev, "No .enable() call-back registered\n"); + return 0; + } + /* only call enable hook if the cell wasn't previously enabled */ if (atomic_inc_return(cell->usage_count) == 1) err = cell->enable(pdev); @@ -45,6 +50,11 @@ int mfd_cell_disable(struct platform_device *pdev) const struct mfd_cell *cell = mfd_get_cell(pdev); int err = 0; + if (!cell->disable) { + dev_dbg(&pdev->dev, "No .disable() call-back registered\n"); + return 0; + } + /* only disable if no other clients are using it */ if (atomic_dec_return(cell->usage_count) == 0) err = cell->disable(pdev); -- 2.17.1