From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg Thelen Subject: Re: [PATCH] net/mlx4: suppress 'may be used uninitialized' warning Date: Tue, 18 Apr 2017 00:24:05 -0700 Message-ID: References: <20170418062135.76698-1-gthelen@google.com> <20170418070219.GA14088@mtr-leonro.local> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <20170418070219.GA14088@mtr-leonro.local> Sender: linux-kernel-owner@vger.kernel.org To: Leon Romanovsky Cc: Or Gerlitz , Jack Morgenstein , Matan Barak , Ido Shamay , Yishai Hadas , Amir Vadai , Roland Dreier , "David S. Miller" , netdev@vger.kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, Tariq Toukan List-Id: linux-rdma@vger.kernel.org Leon Romanovsky wrote: > [ Unknown signature status ] > On Mon, Apr 17, 2017 at 11:21:35PM -0700, Greg Thelen wrote: >> gcc 4.8.4 complains that mlx4_SW2HW_MPT_wrapper() uses an uninitialized >> 'mpt' variable: >> drivers/net/ethernet/mellanox/mlx4/resource_tracker.c: In function 'mlx4_SW2HW_MPT_wrapper': >> drivers/net/ethernet/mellanox/mlx4/resource_tracker.c:2802:12: warning: 'mpt' may be used uninitialized in this function [-Wmaybe-uninitialized] >> mpt->mtt = mtt; >> >> I think this warning is a false complaint. mpt is only used when >> mr_res_start_move_to() return zero, and in all such cases it initializes >> mpt. >> But apparently gcc cannot see that. >> >> Initialize mpt to avoid the warning. >> >> Signed-off-by: Greg Thelen >> --- > > It looks like other callers of mr_res_start_move_to() have the same > "uninitialized" variable. > > Thanks The above is the only mellanox warning I see. So gcc is able to better analyze the other callsites.