From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Levin, Alexander (Sasha Levin)" Subject: Re: [PATCH v2] net/core: Fix BUG to BUG_ON conditionals. Date: Mon, 9 Oct 2017 20:26:34 +0000 Message-ID: <20171009202633.ep5pbi2tlg7dqidz@sasha-lappy> References: <20171009153759.km3lqss7hb72wrze@debian> <20171009171540.lgmk2slq3bdrptxk@ast-mbp.dhcp.thefacebook.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Cc: Tim Hansen , "davem@davemloft.net" , "willemb@google.com" , "edumazet@google.com" , "soheil@google.com" , "pabeni@redhat.com" , "elena.reshetova@intel.com" , "tom@quantonium.net" , "Jason@zx2c4.com" , "fw@strlen.de" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" To: Alexei Starovoitov Return-path: In-Reply-To: <20171009171540.lgmk2slq3bdrptxk@ast-mbp.dhcp.thefacebook.com> Content-Language: en-US Content-ID: <27366CC39A0C184C85A9D6DCD45F6134@vzwcorp.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Mon, Oct 09, 2017 at 10:15:42AM -0700, Alexei Starovoitov wrote: >On Mon, Oct 09, 2017 at 11:37:59AM -0400, Tim Hansen wrote: >> Fix BUG() calls to use BUG_ON(conditional) macros. >> >> This was found using make coccicheck M=3Dnet/core on linux next >> tag next-2017092 >> >> Signed-off-by: Tim Hansen >> --- >> net/core/skbuff.c | 15 ++++++--------- >> 1 file changed, 6 insertions(+), 9 deletions(-) >> >> diff --git a/net/core/skbuff.c b/net/core/skbuff.c >> index d98c2e3ce2bf..34ce4c1a0f3c 100644 >> --- a/net/core/skbuff.c >> +++ b/net/core/skbuff.c >> @@ -1350,8 +1350,7 @@ struct sk_buff *skb_copy(const struct sk_buff *skb= , gfp_t gfp_mask) >> /* Set the tail pointer and length */ >> skb_put(n, skb->len); >> >> - if (skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len)) >> - BUG(); >> + BUG_ON(skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len)); > >I'm concerned with this change. >1. Calling non-trivial bit of code inside the macro is a poor coding style= (imo) >2. BUG_ON !=3D BUG. Some archs like mips and ppc have HAVE_ARCH_BUG_ON and= implementation >of BUG and BUG_ON look quite different. For these archs, wouldn't it then be more efficient to use BUG_ON rather th= an BUG()? --=20 Thanks, Sasha=