From: Shaohua Li <shli@kernel.org>
To: Ming Lei <tom.leiming@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>,
linux-next@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: linux-next: build warning after merge of the md tree
Date: Tue, 28 Mar 2017 08:49:14 -0700 [thread overview]
Message-ID: <20170328154914.tkowin5hm5biybd6@kernel.org> (raw)
In-Reply-To: <20170328081753.GA6743@ming.t460p>
On Tue, Mar 28, 2017 at 04:17:55PM +0800, Ming Lei wrote:
> Hi,
>
> On Tue, Mar 28, 2017 at 03:40:22PM +1100, Stephen Rothwell wrote:
> > Hi Shaohua,
> >
> > After merging the md tree, today's linux-next build (powerpc
> > pseries_le_defconfig) produced this warning:
> >
> > drivers/md/raid1.c: In function 'raid1d':
> > drivers/md/raid1.c:2172:9: warning: 'page_len$' may be used uninitialized in this function [-Wmaybe-uninitialized]
> > if (memcmp(page_address(ppages[j]),
> > ^
> > drivers/md/raid1.c:2160:7: note: 'page_len$' was declared here
> > int page_len[RESYNC_PAGES];
> > ^
> >
> > Introduced by commit
> >
> > 60928a91b0b3 ("md: raid1: use bio helper in process_checks()")
>
> It is a false positive, and looks we have to initialize it for killing
> the warning since I don't find a annotation for addressing uninitialized
> array.
>
> So how about the following patch?
thanks, added.
> ---
>
> From 73fd5ba571465d764fc0cf73fc4169d222dd676a Mon Sep 17 00:00:00 2001
> From: Ming Lei <tom.leiming@gmail.com>
> Date: Tue, 28 Mar 2017 16:09:13 +0800
> Subject: [PATCH] md: raid1: kill warning on powerpc_pseries
>
> This patch kills the warning reported on powerpc_pseries,
> and actually we don't need the initialization.
>
> After merging the md tree, today's linux-next build (powerpc
> pseries_le_defconfig) produced this warning:
>
> drivers/md/raid1.c: In function 'raid1d':
> drivers/md/raid1.c:2172:9: warning: 'page_len$' may be used uninitialized in this function [-Wmaybe-uninitialized]
> if (memcmp(page_address(ppages[j]),
> ^
> drivers/md/raid1.c:2160:7: note: 'page_len$' was declared here
> int page_len[RESYNC_PAGES];
> ^
>
> Signed-off-by: Ming Lei <tom.leiming@gmail.com>
> ---
> drivers/md/raid1.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
> index 3c13286190c1..7e6350334d8e 100644
> --- a/drivers/md/raid1.c
> +++ b/drivers/md/raid1.c
> @@ -2172,7 +2172,7 @@ static void process_checks(struct r1bio *r1_bio)
> struct page **ppages = get_resync_pages(pbio)->pages;
> struct page **spages = get_resync_pages(sbio)->pages;
> struct bio_vec *bi;
> - int page_len[RESYNC_PAGES];
> + int page_len[RESYNC_PAGES] = { 0 };
>
> if (sbio->bi_end_io != end_sync_read)
> continue;
> --
> 2.9.3
>
>
next prev parent reply other threads:[~2017-03-28 15:49 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-28 4:40 linux-next: build warning after merge of the md tree Stephen Rothwell
2017-03-28 8:17 ` Ming Lei
2017-03-28 15:49 ` Shaohua Li [this message]
2017-08-09 3:14 Stephen Rothwell
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