From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by kanga.kvack.org (Postfix) with ESMTP id 1AC816B44B0 for ; Tue, 28 Aug 2018 02:33:06 -0400 (EDT) Received: by mail-ed1-f71.google.com with SMTP id c25-v6so356149edb.12 for ; Mon, 27 Aug 2018 23:33:06 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id b10-v6si584351edk.422.2018.08.27.23.33.04 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 27 Aug 2018 23:33:04 -0700 (PDT) Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w7S6SkkG067451 for ; Tue, 28 Aug 2018 02:33:03 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0a-001b2d01.pphosted.com with ESMTP id 2m513y081k-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 28 Aug 2018 02:33:03 -0400 Received: from localhost by e06smtp01.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 28 Aug 2018 07:33:00 +0100 Date: Tue, 28 Aug 2018 09:32:50 +0300 From: Mike Rapoport Subject: Re: [PATCH 1/2] devres: provide devm_kstrdup_const() References: <20180827082101.5036-1-brgl@bgdev.pl> <20180827103353.GB13848@rapoport-lnx> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Message-Id: <20180828063250.GB25317@rapoport-lnx> 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 , Michal Hocko , Al Viro , Jonathan Corbet , Roman Gushchin , Huang Ying , Kees Cook , Bjorn Andersson , linux-clk , Linux Kernel Mailing List , linux-mm@kvack.org On Mon, Aug 27, 2018 at 04:28:55PM +0200, Bartosz Golaszewski wrote: > 2018-08-27 12:33 GMT+02:00 Mike Rapoport : > > On Mon, Aug 27, 2018 at 10:21:00AM +0200, 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. Also provide a corresponding version of devm_kfree(). > >> > >> Signed-off-by: Bartosz Golaszewski > >> --- > >> include/linux/device.h | 2 ++ > >> mm/util.c | 35 +++++++++++++++++++++++++++++++++++ > >> 2 files changed, 37 insertions(+) > >> > >> diff --git a/include/linux/device.h b/include/linux/device.h > >> index 8f882549edee..f8f5982d26b2 100644 > >> --- a/include/linux/device.h > >> +++ b/include/linux/device.h > >> @@ -693,7 +693,9 @@ 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, void *p); > >> +extern void devm_kfree_const(struct device *dev, void *p); > >> extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc; > >> +extern 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); > >> > >> diff --git a/mm/util.c b/mm/util.c > >> index d2890a407332..6d1f41b5775e 100644 > >> --- a/mm/util.c > >> +++ b/mm/util.c [ ... ] > >> + * Strings allocated by devm_kstrdup_const will be automatically freed when > >> + * the associated device is detached. > >> + */ > >> +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); > >> + > > > > The devm_ variants seem to belong to drivers/base/devres.c rather than > > mm/util.c > > > > Not all devm_ variants live in drivers/base/devres.c, many subsystems > implement them locally. In this case we need to choose between > exporting is_kernel_rodata() and putting devm_kstrdup_const() in > mm/util.c. I chose the latter, since it's cleaner. I rather think that moving is_kernel_rodata() to include/asm-generic/sections.h and having devm_kstrdup_const() next to devm_kstrdup() would be cleaner. > Bart > -- Sincerely yours, Mike.