From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752293AbbIOGnX (ORCPT ); Tue, 15 Sep 2015 02:43:23 -0400 Received: from mga11.intel.com ([192.55.52.93]:28746 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752255AbbIOGnS (ORCPT ); Tue, 15 Sep 2015 02:43:18 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,533,1437462000"; d="scan'208";a="805363203" Message-ID: <1442299382.8361.25.camel@linux.intel.com> Subject: Re: [PATCH v3 2/2] lib/test-string_helpers.c: add string_get_size() tests From: Andy Shevchenko To: Rasmus Villemoes , Vitaly Kuznetsov Cc: Andrew Morton , James Bottomley , linux-kernel@vger.kernel.org, "K. Y. Srinivasan" Date: Tue, 15 Sep 2015 09:43:02 +0300 In-Reply-To: <87y4g8wtjo.fsf@rasmusvillemoes.dk> References: <1442249150-31650-1-git-send-email-vkuznets@redhat.com> <1442249150-31650-3-git-send-email-vkuznets@redhat.com> <87y4g8wtjo.fsf@rasmusvillemoes.dk> Organization: Intel Finland Oy Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.16.3-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2015-09-15 at 00:00 +0200, Rasmus Villemoes wrote: > On Mon, Sep 14 2015, Vitaly Kuznetsov wrote: > Vitaly, thanks for the test cases. My comments below. > > +static __init void test_string_get_size_one(u64 size, u64 > > blk_size, > > + const enum > > string_size_units units, > > + const char > > *exp_result) > > +{ > > + char buf[256]; > > + > > + string_get_size(size, blk_size, units, buf, sizeof(buf)); > > + if (!strncmp(buf, exp_result, min(sizeof(buf), > > strlen(exp_result)))) > > + return; > > Nits: It probably makes sense to also test that string_get_size > '\0'-terminates the buffer, so I'd spell this > > if (!memcmp(buf, exp_result, min(sizeof(buf), > strlen(exp_result)+1))) > > With a generous stack buffer, that min() will always evaluate to the > strlen(exp_result)+1. On that note: Maybe 256 is a bit excessive. I > don't think this will run very deep in the kernel stack, but the code > might > get copy-pasted somewhere else. 16 should be plenty. Agree with Rasmus. And just to make a side note that useless use of min() since we have strnlen() :-) > > > + pr_warn("Test 'test_string_get_size_one' failed!\n"); > > + pr_warn("string_get_size(size = %llu, blk_size = %llu, > > units = %d\n", > > + size, blk_size, units); > > [There's probably no pretty way of getting from units to a text > representation, but it's slightly annoying to have to check the > source > for the enum definition to figure out what units=0 or units=1 means.] > > > + pr_warn("expected: %s, got %s\n", exp_result, buf); > > In case we failed to '\0'-terminate buf, we might want to print it > with > "%.*s", (int)sizeof(buf), buf. But maybe I'm just overly paranoid. I prefer to put '\0' at the position after we expected have an actual '\0'. In this case we always be NULL terminated. I did this for hexdump test cases. -- Andy Shevchenko Intel Finland Oy