From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id 1F3156B0031 for ; Mon, 24 Oct 2011 11:06:57 -0400 (EDT) Date: Mon, 24 Oct 2011 17:06:53 +0200 From: Michal Hocko Subject: Re: [PATCH] swapfile.c: Initialize a variable. Message-ID: <20111024150653.GA18948@tiehlicka.suse.cz> References: <1317876074-25417-1-git-send-email-corone.il.han@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1317876074-25417-1-git-send-email-corone.il.han@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Il Han Cc: linux-mm@kvack.org On Thu 06-10-11 13:41:14, Il Han wrote: > Initialize the variable to remove the following warning. > > mm/swapfile.c:2028: warning: 'span' may be used uninitialized in this function > > Initialize it. It looks that the warning is bogus because span is always initialized if nr_extents >=0. Check out setup_swap_map_and_extents and setup_swap_extents (for S_ISBLK it is trivial and for S_ISREG we are setting the value after we jump out of the loop and all error cases go either to out directly or through bad_bmap labels). It should be much better to use uninitialized_var instead if we just want to shut up compiler. > > Signed-off-by: Il Han > --- > mm/swapfile.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/mm/swapfile.c b/mm/swapfile.c > index 17bc224..d5ca685 100644 > --- a/mm/swapfile.c > +++ b/mm/swapfile.c > @@ -2016,7 +2016,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) > int error; > union swap_header *swap_header; > int nr_extents; > - sector_t span; > + sector_t span = 0; > unsigned long maxpages; > unsigned char *swap_map = NULL; > struct page *page = NULL; > -- > 1.7.4.1 > > -- > 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 -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- 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