From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DDF11C43381 for ; Wed, 20 Feb 2019 08:37:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A5EF120685 for ; Wed, 20 Feb 2019 08:37:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="S/ELlh1G" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726210AbfBTIhN (ORCPT ); Wed, 20 Feb 2019 03:37:13 -0500 Received: from mail-lf1-f67.google.com ([209.85.167.67]:42806 "EHLO mail-lf1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725846AbfBTIhM (ORCPT ); Wed, 20 Feb 2019 03:37:12 -0500 Received: by mail-lf1-f67.google.com with SMTP id l10so16903736lfh.9 for ; Wed, 20 Feb 2019 00:37:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=kGc2Cd4sVzbxMZBKfCCn20jYLojVNMmuJ1uQuDd9OoY=; b=S/ELlh1GSFPyd7a01ReujYHYB4oUtNvQM0mjRFi9Fhn1yJOYorz4ubdoNxShRuzz0L siR0cTjoBvhn7SqR7m3q1T8zwR+VrOg+YKVqgkIj/RZZjRE0t93RYBSqlk/6JDHhl2lq SHVB3xQzXNv95hseKxtFWcqMOnv1Iq6oQ2ZNT1PHbeZkVSnaql9V/Vyrh0x9dsPfMixN bgixfG+bmLlfePSyWUWtN6lftgCkDVJRpka3I7AKliwWuCvxc83QQ2PbizTpBMnsWN85 ogoW0KLRTgLQR31KN7QBqoLO45mk265MQFFn3lnWULx4U44rF3pHbS5DPDJ188xfxgRT t+cA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=kGc2Cd4sVzbxMZBKfCCn20jYLojVNMmuJ1uQuDd9OoY=; b=cYH+HnF8OsEk2y0Zi8ij5T1KGRg+UPeKDWBQ4aX1eu5T84LKwfVIrpb5Xt9xqVy34W m9/aGW3cUBAQjbJwYghqgOTeSvGMrWk+DKpQRFU770duSvDx4vJcQKqjFv05uq41LV6p I2wLkfGTUqwYcoXIQBHt8gr5eK7rHyPddHOXGv+LmYtBczKgWSfKfR4dtoQw+bgJYzYo +qyLNE53mFNiu+AqGZQzJyjs2doc7YuywhMuV8PYqw8qmKVa6peubQnmbOB4EPBSNMDO G/bV+LauUkTVsPzbEZ+JJi/cyYDK4nQ2O79vep/XdKMjbcSLJ/dDaBcWidZG/t8y1AoI S6Kg== X-Gm-Message-State: AHQUAuanUkd+/5tARDnxHNZjgrBDSmrRNdgmeOnFZhWaEie4zjKI28kC 2HX4Y0ubI29LdOMCV1sEBLg= X-Google-Smtp-Source: AHgI3IZ5NOJaWVXJMgq+CIFGv6+YWf4lAVNtVCfEPA33BaiGZRHekC7nKU9Wl8EhjAE2erUzbgBIZA== X-Received: by 2002:ac2:4243:: with SMTP id m3mr19062128lfl.5.1550651830605; Wed, 20 Feb 2019 00:37:10 -0800 (PST) Received: from localhost ([188.162.52.148]) by smtp.gmail.com with ESMTPSA id q15sm1982118lje.89.2019.02.20.00.37.09 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 20 Feb 2019 00:37:09 -0800 (PST) From: Yury Norov X-Google-Original-From: Yury Norov To: Andrew Morton , Andy Shevchenko , Arnd Bergmann , Dmitry Torokhov , Kees Cook , Matthew Wilcox , Michael Ellerman , Rasmus Villemoes , Tetsuo Handa Cc: Yury Norov , linux-kernel@vger.kernel.org, Yury Norov Subject: [PATCH v2 0/5] lib: rework bitmap_parselist and tests Date: Wed, 20 Feb 2019 11:36:59 +0300 Message-Id: <20190220083705.14050-1-ynorov@marvell.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org bitmap_parselist has been evolved from a pretty simple idea for long and now lacks for refactoring. It is not structured, has nested loops and a set of opaque-named variables. All this leads to extremely hard understanding of the code. Once during the optimization of it I missed a scenario which leads to kernel hangup. Tetsuo Handa spotted this and found it simpler to rewrite the code instead fixing it. (Though, that attempt had some flaws.) https://lkml.org/lkml/2018/4/1/93 Things are more complicated than they may be because bitmap_parselist() is part of user interface, and its behavior should not change. In this patchset - __bitmap_parselist() is reworked (patches 2 and 3); - time measurement in test_bitmap_parselist switched to ktime_get (patch 4); - new tests introduced (patch 5), and - bitmap_parselist_user() testing enabled with the same testset as bitmap_parselist() (patch 6). Patch 1 is a fix and may be applied separately. V1: https://lkml.org/lkml/2018/12/23/50 v2: - use PTR_ERR() and ERR_PTR() where appropriate; - fix parser logic (last byte of string handling); - tests for bitmap_parselist_user() in patch 5. Yury Norov (4): bitmap_parselist: don't calculate length of the input string bitmap_parselist: move non-parser logic to helpers bitmap_parselist: rework input string parser lib/test_bitmap: switch test_bitmap_parselist to ktime_get() lib/test_bitmap: add testcases for bitmap_parselist lib/test_bitmap: add tests for bitmap_parselist_user lib/bitmap.c | 293 ++++++++++++++++++++++++++++++---------------- lib/test_bitmap.c | 67 +++++++++-- 2 files changed, 245 insertions(+), 115 deletions(-) -- 2.17.1