On Mon, Oct 09, 2017 at 04:06:20PM -0700, Alexei Starovoitov wrote: >On Mon, Oct 09, 2017 at 08:26:34PM +0000, Levin, Alexander (Sasha Levin) wrote: >> 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=net/core on linux next >> >> tag next-2017092 >> >> >> >> Signed-off-by: Tim Hansen <devtimhan...@gmail.com> >> >> --- >> >> 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 != 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 >> than BUG()? > >why more efficient? any data to prove that?
Just guessing. Either way, is there a particular reason for not using BUG_ON() here besides that it's implementation is "quite different"? >I'm pointing that the change is not equivalent and >this code has been around forever (pre-git days), so I see >no reason to risk changing it. Do you know that BUG_ON() is broken on any archs? If not, "this code has been around forever" is really not an excuse to not touch code. If BUG_ON() behavior is broken somewhere, then it needs to get fixed. -- Thanks, Sasha
