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=-8.8 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 991E4C43382 for ; Fri, 28 Sep 2018 07:14:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5DB6A216FA for ; Fri, 28 Sep 2018 07:14:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=bgdev-pl.20150623.gappssmtp.com header.i=@bgdev-pl.20150623.gappssmtp.com header.b="eNOYYAPc" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5DB6A216FA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bgdev.pl 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 S1729088AbeI1NhC (ORCPT ); Fri, 28 Sep 2018 09:37:02 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:33007 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728952AbeI1Ngs (ORCPT ); Fri, 28 Sep 2018 09:36:48 -0400 Received: by mail-wr1-f67.google.com with SMTP id f10-v6so5198742wrs.0 for ; Fri, 28 Sep 2018 00:14:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bgdev-pl.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=mmvmbHeAPjG3Oc6euefkkNxK3Agi59+XcsUdVG7wIPA=; b=eNOYYAPccrzvANhkDNw26kqlmpRFu+n4SIXSBXPdEeJbPLkdD7VzMA9zRldxYzsL0X +ti+rePqmDBxnAfx3IAbg30up/VijzIanyusNpSFh7BzEI/xqN/lGWHi510Yt6d/65j4 HBKs5DMfCXIIjXzlmaMfb0YJ4En7HMInTqUKk2U9cMk9uHK36WXNfHpGTiP56Jto/kYY I9VlHJmzjC6kT9DzkxFXYjkA8L7j46qsio4ZQZw4Eu46M97VTPAoqv5a2GXMd8Ymewvr LWMHPo+Ef7Q/atDKfBO9SwnhHLsbcgqcMmXYDgwEBTDM/dDyAKCoV2Llbs8XPpTcwhd/ 4K+A== 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=mmvmbHeAPjG3Oc6euefkkNxK3Agi59+XcsUdVG7wIPA=; b=X6GYI9ZKnS25XYlEWQA6+zxPu1UhuT/smhGLMrokxLc+hzRf8zT+bNNdu97LmP7NQS tKE0EYdzxrkRpORYCrY02pWO8cFWZLP7MfwTTjmctr1uq/YSnquN1C3aDcdqvnVM4QnI G6A24V3zT80UIj+RrzTVJmi4xCcH5YXHq5Ou9vYFM22H3RoiiG/E6n15Lzh0sYEUhJN7 AbQCwDUbk7pkV7k00iUwtfN35klOds4RykX7r6M1a/gzFT6LhF9c2r4lI4weZGN6tsLl rjYdiJpdEkk3hV3CM99YQ06HpYRHpx2fRNr4iGPG4hX6IxOqmX2h0hLWctEbEcoS9bR0 ltMQ== X-Gm-Message-State: ABuFfoiT/1rL4nG2DXnvPKBA/SDiAkQtxyr3+HTGMeWdqv7oJ6B/3N73 0N4xmttEQfA4BbjWxn5MXz0nyA== X-Google-Smtp-Source: ACcGV60diTTFYUDpbOd928mTZZjaS5tbfO/hDV+qcR0JJz+7sxMuxuKOO395Mt1wYQ+8c3XChxeJEQ== X-Received: by 2002:adf:bacf:: with SMTP id w15-v6mr11524709wrg.203.1538118866072; Fri, 28 Sep 2018 00:14:26 -0700 (PDT) Received: from brgl-bgdev.sitez.s.ibrowse.com (93-158-26-51.subs.ibrowse.com. [93.158.26.51]) by smtp.gmail.com with ESMTPSA id w3-v6sm2699580wru.93.2018.09.28.00.14.25 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 28 Sep 2018 00:14:25 -0700 (PDT) From: Bartosz Golaszewski To: Greg Kroah-Hartman , "Rafael J . Wysocki" , Jassi Brar , Thierry Reding , Jonathan Hunter , Arnd Bergmann , Andy Shevchenko , Geert Uytterhoeven , Rasmus Villemoes Cc: linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, Bartosz Golaszewski Subject: [PATCH v5 3/4] devres: provide devm_kstrdup_const() Date: Fri, 28 Sep 2018 09:14:13 +0200 Message-Id: <20180928071414.30703-4-brgl@bgdev.pl> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180928071414.30703-1-brgl@bgdev.pl> References: <20180928071414.30703-1-brgl@bgdev.pl> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Provide a resource managed version of kstrdup_const(). This variant internally calls devm_kstrdup() on pointers that are outside of .rodata section and returns the string as is otherwise. Make devm_kfree() check if the passed pointer doesn't point to .rodata and if so - don't actually destroy the resource. Signed-off-by: Bartosz Golaszewski Reviewed-by: Bjorn Andersson Acked-by: Mike Rapoport --- drivers/base/devres.c | 31 +++++++++++++++++++++++++++++++ include/linux/device.h | 2 ++ 2 files changed, 33 insertions(+) diff --git a/drivers/base/devres.c b/drivers/base/devres.c index 438c91a43508..00c70f0fcdcd 100644 --- a/drivers/base/devres.c +++ b/drivers/base/devres.c @@ -11,6 +11,8 @@ #include #include +#include + #include "base.h" struct devres_node { @@ -822,6 +824,28 @@ char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) } EXPORT_SYMBOL_GPL(devm_kstrdup); +/** + * devm_kstrdup_const - resource managed conditional string duplication + * @dev: device for which to duplicate the string + * @s: the string to duplicate + * @gfp: the GFP mask used in the kmalloc() call when allocating memory + * + * Strings allocated by devm_kstrdup_const will be automatically freed when + * the associated device is detached. + * + * RETURNS: + * Source string if it is in .rodata section otherwise it falls back to + * devm_kstrdup. + */ +const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp) +{ + if (is_kernel_rodata((unsigned long)s)) + return s; + + return devm_kstrdup(dev, s, gfp); +} +EXPORT_SYMBOL(devm_kstrdup_const); + /** * devm_kvasprintf - Allocate resource managed space and format a string * into that. @@ -889,6 +913,13 @@ void devm_kfree(struct device *dev, const void *p) { int rc; + /* + * Special case: pointer to a string in .rodata returned by + * devm_kstrdup_const(). + */ + if (unlikely(is_kernel_rodata((unsigned long)p))) + return; + rc = devres_destroy(dev, devm_kmalloc_release, devm_kmalloc_match, (void *)p); WARN_ON(rc); diff --git a/include/linux/device.h b/include/linux/device.h index 33f7cb271fbb..e626acb93ef5 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -694,6 +694,8 @@ static inline void *devm_kcalloc(struct device *dev, } extern void devm_kfree(struct device *dev, const void *p); extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc; +extern const char *devm_kstrdup_const(struct device *dev, + const char *s, gfp_t gfp); extern void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp); -- 2.18.0