Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755306AbaKPJuu (ORCPT ); Sun, 16 Nov 2014 04:50:50 -0500 Received: from terminus.zytor.com ([198.137.202.10]:34392 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755153AbaKPJuq (ORCPT ); Sun, 16 Nov 2014 04:50:46 -0500 Date: Sun, 16 Nov 2014 01:49:59 -0800 From: tip-bot for Maxime COQUELIN Message-ID: Cc: paulmck@linux.vnet.ibm.com, hpa@zytor.com, linux-kernel@vger.kernel.org, eric.paire@st.com, peterz@infradead.org, torvalds@linux-foundation.org, mingo@kernel.org, linux@rasmusvillemoes.dk, tytso@mit.edu, jsrhbz@kanargh.force9.co.uk, maxime.coquelin@st.com, tglx@linutronix.de Reply-To: peterz@infradead.org, eric.paire@st.com, linux-kernel@vger.kernel.org, hpa@zytor.com, paulmck@linux.vnet.ibm.com, maxime.coquelin@st.com, tglx@linutronix.de, jsrhbz@kanargh.force9.co.uk, mingo@kernel.org, torvalds@linux-foundation.org, tytso@mit.edu, linux@rasmusvillemoes.dk In-Reply-To: <1415267659-10563-1-git-send-email-maxime.coquelin@st.com> References: <1415267659-10563-1-git-send-email-maxime.coquelin@st.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:core/urgent] bitops: Fix shift overflow in GENMASK macros Git-Commit-ID: 00b4d9a14125f1e51874def2b9de6092e007412d X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 00b4d9a14125f1e51874def2b9de6092e007412d Gitweb: http://git.kernel.org/tip/00b4d9a14125f1e51874def2b9de6092e007412d Author: Maxime COQUELIN AuthorDate: Thu, 6 Nov 2014 10:54:19 +0100 Committer: Ingo Molnar CommitDate: Sun, 16 Nov 2014 09:55:39 +0100 bitops: Fix shift overflow in GENMASK macros On some 32 bits architectures, including x86, GENMASK(31, 0) returns 0 instead of the expected ~0UL. This is the same on some 64 bits architectures with GENMASK_ULL(63, 0). This is due to an overflow in the shift operand, 1 << 32 for GENMASK, 1 << 64 for GENMASK_ULL. Reported-by: Eric Paire Suggested-by: Rasmus Villemoes Signed-off-by: Maxime Coquelin Signed-off-by: Peter Zijlstra (Intel) Cc: # v3.13+ Cc: linux@rasmusvillemoes.dk Cc: gong.chen@linux.intel.com Cc: John Sullivan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Theodore Ts'o Fixes: 10ef6b0dffe4 ("bitops: Introduce a more generic BITMASK macro") Link: http://lkml.kernel.org/r/1415267659-10563-1-git-send-email-maxime.coquelin@st.com Signed-off-by: Ingo Molnar --- include/linux/bitops.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/include/linux/bitops.h b/include/linux/bitops.h index be5fd38..5d858e0 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -18,8 +18,11 @@ * position @h. For example * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000. */ -#define GENMASK(h, l) (((U32_C(1) << ((h) - (l) + 1)) - 1) << (l)) -#define GENMASK_ULL(h, l) (((U64_C(1) << ((h) - (l) + 1)) - 1) << (l)) +#define GENMASK(h, l) \ + (((~0UL) << (l)) & (~0UL >> (BITS_PER_LONG - 1 - (h)))) + +#define GENMASK_ULL(h, l) \ + (((~0ULL) << (l)) & (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h)))) extern unsigned int __sw_hweight8(unsigned int w); extern unsigned int __sw_hweight16(unsigned int w); -- 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/