Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752777AbaJPUjR (ORCPT ); Thu, 16 Oct 2014 16:39:17 -0400 Received: from mail-lb0-f173.google.com ([209.85.217.173]:37927 "EHLO mail-lb0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752641AbaJPUjP (ORCPT ); Thu, 16 Oct 2014 16:39:15 -0400 MIME-Version: 1.0 In-Reply-To: <20141016182543.GP17447@titan.lakedaemon.net> References: <1413483355-29650-1-git-send-email-rickard_strandqvist@spectrumdigital.se> <20141016182543.GP17447@titan.lakedaemon.net> From: Rickard Strandqvist Date: Thu, 16 Oct 2014 22:38:53 +0200 Message-ID: Subject: Re: [PATCH v4] char: hw_random: core.c: Changed from using strncat to strlcat To: Jason Cooper Cc: Matt Mackall , Herbert Xu , Torsten Duwe , "Theodore Ts'o" , Amit Shah , Stephen Boyd , Paul Gortmaker , Kees Cook , Dan Carpenter , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2014-10-16 20:25 GMT+02:00 Jason Cooper : > On Thu, Oct 16, 2014 at 08:15:55PM +0200, Rickard Strandqvist wrote: >> The buf is used to hold the list of hwrng devices registered. >> The old code ensures we don't walk off the end of buf as we >> fill it, but it's unnecessarily complicated and thus difficult >> to maintain. Simplify it by using strlcat. > >> We also ensure the string within buf is NULL terminated >> so the final strlen is ok. > > This text is no longer necessary. > >> >> Signed-off-by: Rickard Strandqvist > > Please add my: > > Reviewed-by: Jason Cooper > > to the next version of this patch. It makes the maintainers job a *lot* > easier not having to sift through old threads collecting up all the > tags. > > thx, > > Jason. > >> --- >> drivers/char/hw_random/core.c | 11 ++++------- >> 1 file changed, 4 insertions(+), 7 deletions(-) >> >> diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c >> index aa30a25..25599ea 100644 >> --- a/drivers/char/hw_random/core.c >> +++ b/drivers/char/hw_random/core.c >> @@ -281,7 +281,7 @@ static ssize_t hwrng_attr_available_show(struct device *dev, >> char *buf) >> { >> int err; >> - ssize_t ret = 0; >> + ssize_t ret; >> struct hwrng *rng; >> >> err = mutex_lock_interruptible(&rng_mutex); >> @@ -289,13 +289,10 @@ static ssize_t hwrng_attr_available_show(struct device *dev, >> return -ERESTARTSYS; >> buf[0] = '\0'; >> list_for_each_entry(rng, &rng_list, list) { >> - strncat(buf, rng->name, PAGE_SIZE - ret - 1); >> - ret += strlen(rng->name); >> - strncat(buf, " ", PAGE_SIZE - ret - 1); >> - ret++; >> + strlcat(buf, rng->name, PAGE_SIZE); >> + strlcat(buf, " ", PAGE_SIZE); >> } >> - strncat(buf, "\n", PAGE_SIZE - ret - 1); >> - ret++; >> + ret = strlcat(buf, "\n", PAGE_SIZE); >> mutex_unlock(&rng_mutex); >> >> return ret; >> -- >> 1.7.10.4 >> Hello again I was not sure how I would do with others Reviewed-by: But then I know it, did not seem obvious to do, because I actually change some code in between. And I also think about my change, which is actually wrong with using the return value from strlcat the same reason as I mentioned before, it can return strlen + 1 So sorry Joe, I do not think we even can do that :-( So back to my previous patch then, also I update the text again. Kind regards Rickard Strandqvist -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/