From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932598AbdL1Rex (ORCPT ); Thu, 28 Dec 2017 12:34:53 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:60264 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932344AbdL1Reu (ORCPT ); Thu, 28 Dec 2017 12:34:50 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Leon Romanovsky" , "Doug Ledford" , "Christophe Jaillet" , "Majd Dibbiny" Date: Thu, 28 Dec 2017 17:05:44 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 052/204] IB/mlx5: Fix the size parameter to find_first_bit In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.52-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Christophe Jaillet commit fffd68734dc685e208e86d8c5f6522cd695a8d60 upstream. The 2nd parameter of 'find_first_bit' is the number of bits to search. In this case, we are passing 'sizeof(tmp)' which is likely to be 4 or 8 because 'tmp' is an 'unsigned long'. It is likely that the number of bits of 'tmp' was expected here. So use BITS_PER_LONG instead. It has been spotted by the following coccinelle script: @@ expression ret, x; @@ * ret = \(find_first_bit \| find_first_zero_bit\) (x, sizeof(...)); Signed-off-by: Christophe JAILLET Acked-by: Majd Dibbiny Acked-by: Leon Romanovsky Signed-off-by: Doug Ledford Signed-off-by: Ben Hutchings --- drivers/infiniband/hw/mlx5/mem.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/infiniband/hw/mlx5/mem.c +++ b/drivers/infiniband/hw/mlx5/mem.c @@ -58,7 +58,7 @@ void mlx5_ib_cont_pages(struct ib_umem * addr = addr >> PAGE_SHIFT; tmp = (unsigned long)addr; - m = find_first_bit(&tmp, sizeof(tmp)); + m = find_first_bit(&tmp, BITS_PER_LONG); skip = 1 << m; mask = skip - 1; i = 0; @@ -68,7 +68,7 @@ void mlx5_ib_cont_pages(struct ib_umem * for (k = 0; k < len; k++) { if (!(i & mask)) { tmp = (unsigned long)pfn; - m = min_t(unsigned long, m, find_first_bit(&tmp, sizeof(tmp))); + m = min_t(unsigned long, m, find_first_bit(&tmp, BITS_PER_LONG)); skip = 1 << m; mask = skip - 1; base = pfn; @@ -76,7 +76,7 @@ void mlx5_ib_cont_pages(struct ib_umem * } else { if (base + p != pfn) { tmp = (unsigned long)p; - m = find_first_bit(&tmp, sizeof(tmp)); + m = find_first_bit(&tmp, BITS_PER_LONG); skip = 1 << m; mask = skip - 1; base = pfn;