From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] nfp: bpf: improve handling for disabled BPF syscall Date: Mon, 26 Sep 2016 02:28:09 -0400 (EDT) Message-ID: <20160926.022809.551158468707292513.davem@davemloft.net> References: <20160923202443.4130858-1-arnd@arndb.de> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: jakub.kicinski@netronome.com, oss-drivers@netronome.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: arnd@arndb.de Return-path: In-Reply-To: <20160923202443.4130858-1-arnd@arndb.de> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Arnd Bergmann Date: Fri, 23 Sep 2016 22:23:59 +0200 > I stumbled over a new warning during randconfig testing, > with CONFIG_BPF_SYSCALL disabled: > > drivers/net/ethernet/netronome/nfp/nfp_net_offload.c: In function 'nfp_net_bpf_offload': > drivers/net/ethernet/netronome/nfp/nfp_net_offload.c:263:3: error: '*((void *)&res+4)' may be used uninitialized in this function [-Werror=maybe-uninitialized] > drivers/net/ethernet/netronome/nfp/nfp_net_offload.c:263:3: error: 'res.n_instr' may be used uninitialized in this function [-Werror=maybe-uninitialized] > > As far as I can tell, this is a false positive caused by the compiler > getting confused about a function that is partially inlined, but it's > easy to avoid while improving the code: > > The nfp_bpf_jit() stub helper for that configuration is unusual as it > is defined in a header file but not marked 'static inline'. By moving > the compile-time check into the caller using the IS_ENABLED() macro, > we can remove that stub and simplify the nfp_net_bpf_offload_prepare() > function enough to unconfuse the compiler. > > Fixes: 7533fdc0f77f ("nfp: bpf: add hardware bpf offload") > Signed-off-by: Arnd Bergmann Applied, thanks.