From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757244AbbJ2Qaz (ORCPT ); Thu, 29 Oct 2015 12:30:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57726 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756132AbbJ2Qax (ORCPT ); Thu, 29 Oct 2015 12:30:53 -0400 From: Vitaly Kuznetsov To: Andrew Morton Cc: Rasmus Villemoes , Andy Shevchenko , Ulf Hansson , James Bottomley , Kees Cook , linux-kernel@vger.kernel.org Subject: [PATCH v3 0/4] lib/string_helpers: fix precision issues and introduce tests Date: Thu, 29 Oct 2015 17:30:46 +0100 Message-Id: <1446136250-11507-1-git-send-email-vkuznets@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linux always lies about your storage size when it has 4k sectors and its size is big enough. E.g. a device with 8192 4k sectors will be reported as "32.7 MB/32 MiB" while "33.5 MB/32 MiB" is expected. This series is supposed to fix the issue by fixing calculation precision in string_get_size() for all possible inputs. PATCH 1/4 is a preparatory change, PATCH 2/4 adds additional protection against blk_size=0 (nobody is supposed to call string_get_size() with with blk_size=0, but better safe than sorry), PATCH 3/4 re-factors string_get_size() fixing the issue, PATCH 4/4 introduces tests for string_get_size(). PATCH 4/4 was previously sent as part of "lib/string_helpers.c: fix infinite loop in string_get_size()" series but it is still not merged upstream. In this submission I improve it and add additional tests to it. Changes since v2: - Separate blk_size check from Patch 3/4 to new Patch 2/4 [Andy Shevchenko] - Slightly change the algorithm in Patch 3/4 [Rasmus Villemoes] Vitaly Kuznetsov (4): lib/string_helpers: change blk_size to u32 for string_get_size() interface lib/string_helpers.c: protect string_get_size() against blk_size=0 lib/string_helpers.c: don't lose precision in string_get_size() lib/test-string_helpers.c: add string_get_size() tests include/linux/string_helpers.h | 2 +- lib/string_helpers.c | 38 ++++++++++++++------------- lib/test-string_helpers.c | 58 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 79 insertions(+), 19 deletions(-) -- 2.4.3