From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx145.postini.com [74.125.245.145]) by kanga.kvack.org (Postfix) with SMTP id 3CC946B00E7 for ; Wed, 18 Apr 2012 02:16:59 -0400 (EDT) Received: from /spool/local by e28smtp07.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 18 Apr 2012 11:46:54 +0530 Received: from d28av04.in.ibm.com (d28av04.in.ibm.com [9.184.220.66]) by d28relay05.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q3I6Gpjm4448264 for ; Wed, 18 Apr 2012 11:46:51 +0530 Received: from d28av04.in.ibm.com (loopback [127.0.0.1]) by d28av04.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q3IBkZWD031763 for ; Wed, 18 Apr 2012 21:46:38 +1000 From: "Aneesh Kumar K.V" Subject: Re: [PATCH -V6 10/14] hugetlbfs: Add memcg control files for hugetlbfs In-Reply-To: <20120416161354.b967790c.akpm@linux-foundation.org> References: <1334573091-18602-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1334573091-18602-11-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20120416161354.b967790c.akpm@linux-foundation.org>User-Agent: Notmuch/0.11.1+346~g13d19c3 (http://notmuchmail.org) Emacs/23.3.1 (x86_64-pc-linux-gnu) Date: Wed, 18 Apr 2012 11:46:37 +0530 Message-ID: <87d375womy.fsf@skywalker.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, mgorman@suse.de, kamezawa.hiroyu@jp.fujitsu.com, dhillf@gmail.com, aarcange@redhat.com, mhocko@suse.cz, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Andrew Morton writes: > On Mon, 16 Apr 2012 16:14:47 +0530 > "Aneesh Kumar K.V" wrote: > >> +#ifdef CONFIG_MEM_RES_CTLR_HUGETLB >> +static char *mem_fmt(char *buf, unsigned long n) >> +{ >> + if (n >= (1UL << 30)) >> + sprintf(buf, "%luGB", n >> 30); >> + else if (n >= (1UL << 20)) >> + sprintf(buf, "%luMB", n >> 20); >> + else >> + sprintf(buf, "%luKB", n >> 10); >> + return buf; >> +} >> + >> +int __init mem_cgroup_hugetlb_file_init(int idx) >> +{ >> + char buf[32]; >> + struct cftype *cft; >> + struct hstate *h = &hstates[idx]; >> + >> + /* format the size */ >> + mem_fmt(buf, huge_page_size(h)); > > The sprintf() into a fixed-sized buffer is a bit ugly. I didn't check > it for possible overflows because 32 looks like "enough". Actually too > much. > > Oh well, it's hard to avoid. But using scnprintf() would prevent nasty > accidents. > diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 519d370..0ccf934 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5269,14 +5269,14 @@ static void mem_cgroup_destroy(struct cgroup *cont) } #ifdef CONFIG_MEM_RES_CTLR_HUGETLB -static char *mem_fmt(char *buf, unsigned long n) +static char *mem_fmt(char *buf, int size, unsigned long hsize) { - if (n >= (1UL << 30)) - sprintf(buf, "%luGB", n >> 30); - else if (n >= (1UL << 20)) - sprintf(buf, "%luMB", n >> 20); + if (hsize >= (1UL << 30)) + scnprintf(buf, size, "%luGB", hsize >> 30); + else if (hsize >= (1UL << 20)) + scnprintf(buf, size, "%luMB", hsize >> 20); else - sprintf(buf, "%luKB", n >> 10); + scnprintf(buf, size, "%luKB", hsize >> 10); return buf; } @@ -5287,7 +5287,7 @@ int __init mem_cgroup_hugetlb_file_init(int idx) struct hstate *h = &hstates[idx]; /* format the size */ - mem_fmt(buf, huge_page_size(h)); + mem_fmt(buf, 32, huge_page_size(h)); /* Add the limit file */ cft = &h->mem_cgroup_files[0]; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org