Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423506AbbD2PAc (ORCPT ); Wed, 29 Apr 2015 11:00:32 -0400 Received: from sender1.zohomail.com ([74.201.84.155]:35687 "EHLO sender1.zohomail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1423246AbbD2PAY (ORCPT ); Wed, 29 Apr 2015 11:00:24 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=zapps768; d=zoho.com; h=date:from:to:cc:subject:message-id:references:mime-version:content-type:in-reply-to; b=hJAyAT8Wp+k2B3JdxWl33kPq5HLxI1DONCA8ivB+atF2Q9URL4uQsVM5c00vbUBhDLG5aeuY7uYY 9+zTGZBObhrvKHXpI3klxRqC1r3lmlp6uq48CZQloT1Pydw9dGdN Date: Wed, 29 Apr 2015 14:59:56 +0000 From: mancha security To: Pranith Kumar Cc: Daniel Borkmann , "H. Peter Anvin" , LKML , Ingo Molnar Subject: Re: [PATCH] compiler-intel: fix wrong compiler barrier() macro Message-ID: <20150429145956.GB12861@zoho.com> References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="TakKZr9L6Hm6aLOc" Content-Disposition: inline In-Reply-To: X-PGP-Key: http://hkps.pool.sks-keyservers.net/pks/lookup?op=vindex&search=0x25168eb24f0b22ac X-PGP-FP: 56B7 100E F4D5 811C 8FEF ADD1 2516 8EB2 4F0B 22AC X-Zoho-Virus-Status: 1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2343 Lines: 63 --TakKZr9L6Hm6aLOc Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Apr 29, 2015 at 10:51:40AM -0400, Pranith Kumar wrote: > Hi Daniel, >=20 > On Wed, Apr 29, 2015 at 10:42 AM, Daniel Borkmann = wrote: > > Cleanup commit 23ebdedc67e ("compiler-intel.h: Remove duplicate > > definition") removed the double definition of __memory_barrier() > > intrinsics. > > > > However, in doing so, it also removed the preceding #undef barrier, > > meaning, the actual barrier() macro from compiler-gcc.h with inline > > asm is still in place when __GNUC__ is provided. >=20 > When you use the Intel compilers, the barrier() definition will come > from compiler.h and not compiler-gcc.h. That is what the commit > message says in 73679e508201(your commit message has the wrong hash). > I don't understand what problem you are seeing with this, can you > please explain? >=20 > Thanks! Hi Pranith. The problem is that ICC defines __GNUC__ so barrier() gets defined in compiler-gcc.h. Your commit removed an #undef from compiler-intel.h so compiler.h will never define barrier to __memory_barrier(). --mancha --TakKZr9L6Hm6aLOc Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBCgAGBQJVQPHsAAoJEB4VYy8JqhaDVxwP+QEcclU9ZnNRDW3DK+3HnHG8 sP+nkS0QlVmCqi/U1d2gUK2/80dOFweDoUsQvOYzj655T5EysFlvCO9lH10voHHo EjiEaFPBVDFkRdxmeLn/cm2MVsY/g6Tstxykcdkdqg9Zn+OKLk4jnKj2a442dyvi uEPQuVG3QPiW5gr1MYXTqasIXOHr6QyPTCTzX7cMmM1oIjO8IDk3DUNP8gsXcqeQ yDpVSrNs0OZ6cRpLW62nbCePCY5nWzhxgWvsB0ZqsWT4szQvT+ndM2I+iwwU5MM1 d8KF6xfedLZGLy8z5FRgEuVdNO1vjxvZOoVRv+9Nl0bhi7nAbLR6bW1HMwoAxH25 mMKKsXeHFAyeiIDhZfVDKeppLgVkwf/HDfWP5ch+X/YXufK1f3ft6ouyG3w8nn2j Heuwm8bJ80flOrvPcH8MW3B+Q9el6OMsMd4XyshSJ7rth2Mo+eti9ca1WSBBtNC7 6gzfptjABgQ86uEHV0r7r9o/P9odhXNOCPUOTywbldAatyki/1W4VKQHAnT1mJQs xd4nJ16SKQ0L5qfnjWlOLs7bKcM/9c43LAD0nJZ5rSAdLl0CaO2V9/NpnvvH0g+t 6cVz3ahr9OSUtutoLx4ufyAR9pfuqKssPx0cp/eF4yL4Ja29WSLuMhv7B68M12Lb GJsJsKXROOvHXDTlejvQ =trwM -----END PGP SIGNATURE----- --TakKZr9L6Hm6aLOc-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/