From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f200.google.com (mail-pf1-f200.google.com [209.85.210.200]) by kanga.kvack.org (Postfix) with ESMTP id C9C738E0001 for ; Thu, 20 Sep 2018 12:34:57 -0400 (EDT) Received: by mail-pf1-f200.google.com with SMTP id u13-v6so4940587pfm.8 for ; Thu, 20 Sep 2018 09:34:57 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id u10-v6sor5198655plu.19.2018.09.20.09.34.56 for (Google Transport Security); Thu, 20 Sep 2018 09:34:56 -0700 (PDT) Date: Thu, 20 Sep 2018 09:39:06 -0700 From: Bjorn Andersson Subject: Re: [PATCH v2 3/4] devres: provide devm_kstrdup_const() Message-ID: <20180920163905.GH1367@tuxbook-pro> References: <20180828093332.20674-1-brgl@bgdev.pl> <20180828093332.20674-4-brgl@bgdev.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180828093332.20674-4-brgl@bgdev.pl> Sender: owner-linux-mm@kvack.org List-ID: To: Bartosz Golaszewski Cc: Michael Turquette , Stephen Boyd , Greg Kroah-Hartman , "Rafael J . Wysocki" , Arend van Spriel , Ulf Hansson , Bjorn Helgaas , Vivek Gautam , Robin Murphy , Joe Perches , Heikki Krogerus , Andrew Morton , Mike Rapoport , Michal Hocko , Al Viro , Jonathan Corbet , Roman Gushchin , Huang Ying , Kees Cook , Arnd Bergmann , linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org On Tue 28 Aug 02:33 PDT 2018, Bartosz Golaszewski wrote: > 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. > > Also provide a corresponding version of devm_kfree(). > > Signed-off-by: Bartosz Golaszewski Reviewed-by: Bjorn Andersson Regards, Bjorn > --- > drivers/base/devres.c | 38 ++++++++++++++++++++++++++++++++++++++ > include/linux/device.h | 3 +++ > 2 files changed, 41 insertions(+) > > diff --git a/drivers/base/devres.c b/drivers/base/devres.c > index 438c91a43508..48185d57bc5b 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. > @@ -895,6 +919,20 @@ void devm_kfree(struct device *dev, const void *p) > } > EXPORT_SYMBOL_GPL(devm_kfree); > > +/** > + * devm_kfree_const - Resource managed conditional kfree > + * @dev: device this memory belongs to > + * @p: memory to free > + * > + * Function calls devm_kfree only if @p is not in .rodata section. > + */ > +void devm_kfree_const(struct device *dev, const void *p) > +{ > + if (!is_kernel_rodata((unsigned long)p)) > + devm_kfree(dev, p); > +} > +EXPORT_SYMBOL(devm_kfree_const); > + > /** > * devm_kmemdup - Resource-managed kmemdup > * @dev: Device this memory belongs to > diff --git a/include/linux/device.h b/include/linux/device.h > index 33f7cb271fbb..79ccc6eb0975 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -693,7 +693,10 @@ static inline void *devm_kcalloc(struct device *dev, > return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO); > } > extern void devm_kfree(struct device *dev, const void *p); > +extern void devm_kfree_const(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 >