From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f198.google.com (mail-io0-f198.google.com [209.85.223.198]) by kanga.kvack.org (Postfix) with ESMTP id 49B376B4075 for ; Mon, 27 Aug 2018 08:28:48 -0400 (EDT) Received: by mail-io0-f198.google.com with SMTP id n17-v6so13827261ioa.5 for ; Mon, 27 Aug 2018 05:28:48 -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 v81-v6sor3130838itf.134.2018.08.27.05.28.46 for (Google Transport Security); Mon, 27 Aug 2018 05:28:46 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20180827103915.GC13848@rapoport-lnx> References: <20180827082101.5036-1-brgl@bgdev.pl> <20180827082101.5036-2-brgl@bgdev.pl> <20180827103915.GC13848@rapoport-lnx> From: Bartosz Golaszewski Date: Mon, 27 Aug 2018 14:28:45 +0200 Message-ID: Subject: Re: [PATCH 2/2] clk: pmc-atom: use devm_kstrdup_const() Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: Mike Rapoport 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 2018-08-27 12:39 GMT+02:00 Mike Rapoport : > On Mon, Aug 27, 2018 at 10:21:01AM +0200, Bartosz Golaszewski wrote: >> Use devm_kstrdup_const() in the pmc-atom driver. This mostly serves as >> an example of how to use this new routine to shrink driver code. >> >> While we're at it: replace a call to kcalloc() with devm_kcalloc(). >> >> Signed-off-by: Bartosz Golaszewski >> --- >> drivers/clk/x86/clk-pmc-atom.c | 19 ++++--------------- >> 1 file changed, 4 insertions(+), 15 deletions(-) >> >> diff --git a/drivers/clk/x86/clk-pmc-atom.c b/drivers/clk/x86/clk-pmc-atom.c >> index 08ef69945ffb..daa2192e6568 100644 >> --- a/drivers/clk/x86/clk-pmc-atom.c >> +++ b/drivers/clk/x86/clk-pmc-atom.c >> @@ -253,14 +253,6 @@ static void plt_clk_unregister_fixed_rate_loop(struct clk_plt_data *data, >> plt_clk_unregister_fixed_rate(data->parents[i]); >> } >> >> -static void plt_clk_free_parent_names_loop(const char **parent_names, >> - unsigned int i) >> -{ >> - while (i--) >> - kfree_const(parent_names[i]); >> - kfree(parent_names); >> -} >> - >> static void plt_clk_unregister_loop(struct clk_plt_data *data, >> unsigned int i) >> { >> @@ -286,8 +278,8 @@ static const char **plt_clk_register_parents(struct platform_device *pdev, >> if (!data->parents) >> return ERR_PTR(-ENOMEM); >> >> - parent_names = kcalloc(nparents, sizeof(*parent_names), >> - GFP_KERNEL); >> + parent_names = devm_kcalloc(&pdev->dev, nparents, >> + sizeof(*parent_names), GFP_KERNEL); >> if (!parent_names) >> return ERR_PTR(-ENOMEM); >> >> @@ -300,7 +292,8 @@ static const char **plt_clk_register_parents(struct platform_device *pdev, >> err = PTR_ERR(data->parents[i]); >> goto err_unreg; >> } >> - parent_names[i] = kstrdup_const(clks[i].name, GFP_KERNEL); >> + parent_names[i] = devm_kstrdup_const(&pdev->dev, >> + clks[i].name, GFP_KERNEL); >> } >> >> data->nparents = nparents; >> @@ -308,7 +301,6 @@ static const char **plt_clk_register_parents(struct platform_device *pdev, >> >> err_unreg: >> plt_clk_unregister_fixed_rate_loop(data, i); >> - plt_clk_free_parent_names_loop(parent_names, i); > > What happens if clks[i].name is not a part of RO data? The devm_kstrdup_const > will allocate memory and nothing will ever free it... > I'm looking at it and trying to see if I'm missing something, but AFAIK the whole concept of devm_* is to leave out the resource management part. devm_kstrdup_const() will internally call devm_kstrdup() for strings that are not in .rodata and once the device is detached, the string will be freed (or not if it's in .rodata). BR Bart > And, please don't drop kfree(parent_names) here. > >> return ERR_PTR(err); >> } >> >> @@ -351,15 +343,12 @@ static int plt_clk_probe(struct platform_device *pdev) >> goto err_unreg_clk_plt; >> } >> >> - plt_clk_free_parent_names_loop(parent_names, data->nparents); >> - >> platform_set_drvdata(pdev, data); >> return 0; >> >> err_unreg_clk_plt: >> plt_clk_unregister_loop(data, i); >> plt_clk_unregister_parents(data); >> - plt_clk_free_parent_names_loop(parent_names, data->nparents); > > Ditto. > >> return err; >> } >> >> -- >> 2.18.0 >> > > -- > Sincerely yours, > Mike. >