From: Ingo Molnar Date: Fri, 01 Jul 2016 10:13:30 +0000 Subject: Re: [patch] crypto: sha256-mb - cleanup a || vs | typo Message-Id: <20160701101329.GA3833@gmail.com> List-Id: References: <20160629144242.GE22818@mwanda> <8538242a-eab7-127e-e47e-26027fee4f6d@zytor.com> <1467319339.22178.256.camel@linux.intel.com> <20160701075559.GA11902@gmail.com> <20160701092806.GA13424@gondor.apana.org.au> In-Reply-To: <20160701092806.GA13424@gondor.apana.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: Herbert Xu Cc: Tim Chen , "H. Peter Anvin" , Dan Carpenter , "David S. Miller" , Thomas Gleixner , Ingo Molnar , x86@kernel.org, Megha Dey , "Wang, Rui Y" , Denys Vlasenko , Xiaodong Liu , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, Linus Torvalds , Andrew Morton , Peter Zijlstra * Herbert Xu wrote: > On Fri, Jul 01, 2016 at 09:55:59AM +0200, Ingo Molnar wrote: > > > > Plus: > >=20 > > > > > =A0 /* Compute how many bytes to copy from user buffer into > > > > > =A0 =A0* extra block > > > > > =A0 =A0*/ > >=20 > > please use the customary (multi-line) comment style: >=20 > This is the customary comment style of the networking stack and > the crypto API. So please don't change it. Guys, do you even read your own code?? That 'standard' is not being enforced consistently at all. Even in this ver= y=20 series there's an example of that weird comment not being followed: +++ b/arch/x86/crypto/sha1-mb/sha1_mb.c @@ -304,7 +304,7 @@ static struct sha1_hash_ctx *sha1_ctx_mgr_submit(struct= sha1_ctx_mgr *mgr, /* * Compute how many bytes to copy from user buffer into * extra block See how this comment block uses the standard coding style, while the next p= atch=20 has this weird coding style: - if ((ctx->partial_block_buffer_length) | (len < SHA256_BLOCK_SIZE))= { + if ((ctx->partial_block_buffer_length) || (len < SHA256_BLOCK_SIZE)= ) { /* Compute how many bytes to copy from user buffer into * extra block */ The networking code's "exceptionalism" regarding the standard comment style= is=20 super distracting and in this particular example it resulted in: - inconsistent comment styles next to each other, - the questionable '|' pattern hiding right next to: - pointless parantheses around the (ctx->partial_block_buffer_length), - which field name is also a misnomer. So anyone doing security review of that weird '|' pattern first has to figu= re out=20 whether the 4 ugly code patterns amount to a security problem or not... One thing that is more harmful that any of the coding styles: the inconsist= ent=20 coding style used by this code. Btw., as a historic reference, there is nothing sacred about the 'networkin= g=20 comments coding style': I was there (way too many years ago) when that comm= ent=20 style was introduced by Alan Cox's first TCP/IP code drop, and it was littl= e more=20 than just a random inconsistency that people are now treating as gospel... Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html