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 66FE5C7112C for ; Sun, 14 Oct 2018 15:20:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 253D120876 for ; Sun, 14 Oct 2018 15:20:26 +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="hCQx1K5R" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 253D120876 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 S1726736AbeJNXBl (ORCPT ); Sun, 14 Oct 2018 19:01:41 -0400 Received: from mail-wr1-f66.google.com ([209.85.221.66]:41701 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726363AbeJNXBk (ORCPT ); Sun, 14 Oct 2018 19:01:40 -0400 Received: by mail-wr1-f66.google.com with SMTP id x12-v6so18355071wru.8 for ; Sun, 14 Oct 2018 08:20:23 -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 :mime-version:content-transfer-encoding; bh=YDVENKVWOJgFEZ88TbmXetJ81nbm7Zo0Uj8ZIHPmj3U=; b=hCQx1K5RLTa7EAW0on1YYORgSUVMkHCLGlFyEO9yXIDbNeluWAWErX1NN9aM+WCADE ipnztD1GhlXFpW73Z8f6FIShNh26fmtHIMxgn2XdwZnyYDEUfaPL5sDt4lqQdF/TW+GS cDT++0uO/XvqpWEgoCjij78sN6X/hFGT1pwkflsvUIqrTq5+cFfdLp4iO6IwJMEfX7aO NTd1EnfZ8/UDnNvTFIdPkyhhrgP7++bprVtKBZL8ZAsI4TKrmgn1KWec8WcEXBQf9h4c LXijOfG4zHFbj6HXUS+cyY8tyJrvm5wcK6TL4fpPhJ47WyFh3mGgBsXXrdZJETEA+LS5 HVrg== 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=YDVENKVWOJgFEZ88TbmXetJ81nbm7Zo0Uj8ZIHPmj3U=; b=kFbYYqlnwd0TfvBBMdWmyzpxcUyPiygLwT9Aswa1kV6+30vWpkCS+XaC/Ly7JY88te UITkedCEkogrOMQaHSjb/ZnyjRafCwP3SbDhF5HbsaQdOoqodw+b84npRPbHJy7ZK6zW PjP/QuqP3y08xIegueHHQk6XS2K4tYhXU1RNfEco6FDR14OTwJlLhrqXsOiws0mPrywJ ZIgINBKQxbGI7Sp1bXIZ9CmvkLzvIB97B6eTVb/JxHzetgPJmkOkUqMmqRR0D/ucMF2r ql5aVg3mUzspOAvWgAOUPrCml2ZWKc6Ao4H2cKoUYjYx2xFHyBDmVYImuY9yziokW2nf my4A== X-Gm-Message-State: ABuFfojXb4PyiYEzb5OIW7UY7wqR/R0Aj9N9KIup06SjsGk+7QXXiBY1 u+DSnUzLGUa7TsL+kPG38+IZOmduDjw= X-Google-Smtp-Source: ACcGV62vns+I4hTEGXDH2LiX3Emw3xTh9MKY2HkBXcya9KsWzSWGFVRDiKCT1chL0iDe2mZDvmKxKg== X-Received: by 2002:adf:9d26:: with SMTP id k38-v6mr12282396wre.18.1539530422790; Sun, 14 Oct 2018 08:20:22 -0700 (PDT) Received: from localhost.localdomain ([2a01:cb1d:af:5b00:6d6c:8493:1ab5:dad7]) by smtp.gmail.com with ESMTPSA id b139-v6sm14789830wmd.36.2018.10.14.08.20.21 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 14 Oct 2018 08:20:22 -0700 (PDT) From: Bartosz Golaszewski To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, Bartosz Golaszewski Subject: [RESEND PATCH v6 3/4] devres: provide devm_kstrdup_const() Date: Sun, 14 Oct 2018 17:20:09 +0200 Message-Id: <20181014152010.2021-4-brgl@bgdev.pl> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181014152010.2021-1-brgl@bgdev.pl> References: <20181014152010.2021-1-brgl@bgdev.pl> 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 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 Acked-by: Rasmus Villemoes Reviewed-by: Geert Uytterhoeven Reviewed-by: Andy Shevchenko --- 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); -- 2.19.1