From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932875AbcHBC2v (ORCPT ); Mon, 1 Aug 2016 22:28:51 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:62069 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932603AbcHBC2j (ORCPT ); Mon, 1 Aug 2016 22:28:39 -0400 Message-ID: <57A004C7.10307@huawei.com> Date: Tue, 2 Aug 2016 10:26:15 +0800 From: zhong jiang User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Andrew Morton CC: , Subject: Re: [PATCH] fs: fix a bug when new_insert_key is not initialization References: <1469850669-64815-1-git-send-email-zhongjiang@huawei.com> <20160801160510.4a48a02d68aa5d89a0435b52@linux-foundation.org> In-Reply-To: <20160801160510.4a48a02d68aa5d89a0435b52@linux-foundation.org> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.29.68] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A0B0201.57A004CE.0030,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: dbd336f18e933deb9fc0c22ca3523116 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2016/8/2 7:05, Andrew Morton wrote: > On Sat, 30 Jul 2016 11:51:09 +0800 zhongjiang wrote: > >> From: zhong jiang >> >> when compile the kenrel code, I happens to the following warn. >> fs/reiserfs/ibalance.c:1156:2: warning: ___new_insert_key___ may be used >> uninitialized in this function. >> memcpy(new_insert_key_addr, &new_insert_key, KEY_SIZE); >> >> The patch fix it by check the new_insert_ptr. if new_insert_ptr is not >> NULL, we ensure that new_insert_key is assigned. therefore, memcpy will >> saftly exec the operatetion. >> >> --- a/fs/reiserfs/ibalance.c >> +++ b/fs/reiserfs/ibalance.c >> @@ -1153,8 +1153,10 @@ int balance_internal(struct tree_balance *tb, >> insert_ptr); >> } >> >> - memcpy(new_insert_key_addr, &new_insert_key, KEY_SIZE); >> - insert_ptr[0] = new_insert_ptr; >> + if (new_insert_ptr) { >> + memcpy(new_insert_key_addr, &new_insert_key, KEY_SIZE); >> + insert_ptr[0] = new_insert_ptr; >> + } >> >> return order; > Jeff has aleady fixed this with an equivalent patch. It's in -mm at > present. > > From: Jeff Mahoney > Subject: reiserfs: fix "new_insert_key may be used uninitialized ..." > > new_insert_key only makes any sense when it's associated with a > new_insert_ptr, which is initialized to NULL and changed to a buffer_head > when we also initialize new_insert_key. We can key off of that to avoid > the uninitialized warning. > > Link: http://lkml.kernel.org/r/5eca5ffb-2155-8df2-b4a2-f162f105efed@suse.com > Signed-off-by: Jeff Mahoney > Cc: Arnd Bergmann > Cc: Jan Kara > Cc: Linus Torvalds > Signed-off-by: Andrew Morton > --- > > fs/reiserfs/ibalance.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff -puN fs/reiserfs/ibalance.c~reiserfs-fix-new_insert_key-may-be-used-uninitialized fs/reiserfs/ibalance.c > --- a/fs/reiserfs/ibalance.c~reiserfs-fix-new_insert_key-may-be-used-uninitialized > +++ a/fs/reiserfs/ibalance.c > @@ -1153,8 +1153,9 @@ int balance_internal(struct tree_balance > insert_ptr); > } > > - memcpy(new_insert_key_addr, &new_insert_key, KEY_SIZE); > insert_ptr[0] = new_insert_ptr; > + if (new_insert_ptr) > + memcpy(new_insert_key_addr, &new_insert_key, KEY_SIZE); > > return order; > } > _ > > > . > ok , I did not notice. thanks.