From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753243AbdL1KfA (ORCPT ); Thu, 28 Dec 2017 05:35:00 -0500 Received: from mail2-relais-roc.national.inria.fr ([192.134.164.83]:9521 "EHLO mail2-relais-roc.national.inria.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752726AbdL1Ke6 (ORCPT ); Thu, 28 Dec 2017 05:34:58 -0500 X-IronPort-AV: E=Sophos;i="5.45,470,1508796000"; d="scan'208";a="307058145" Date: Thu, 28 Dec 2017 11:34:56 +0100 (CET) From: Julia Lawall X-X-Sender: jll@hadrien To: Ingo Molnar cc: Andy Shevchenko , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Andi Kleen , linux-kernel@vger.kernel.org, Darren Hart , platform-driver-x86@vger.kernel.org, Bhumika Goyal , Julia Lawall Subject: Re: [PATCH v1] x86/platform/intel-mid: Revert "Make 'bt_sfi_data' const" In-Reply-To: <20171228102812.cm7yylrrq2omfw5y@gmail.com> Message-ID: References: <20171228100801.67744-1-andriy.shevchenko@linux.intel.com> <20171228102812.cm7yylrrq2omfw5y@gmail.com> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 28 Dec 2017, Ingo Molnar wrote: > > * Andy Shevchenko wrote: > > > The annoying static analyzer follow up patches make a pain rather then > > fixing issues. > > > > The one done by commit 276c87054751 > > > > ("x86/platform/intel-mid: Make 'bt_sfi_data' const") > > > > made an obvious regression [BugLink] since the struct bt_sfi_data used > > as a temporary container for important data that is used to fill > > 'parent' and 'name' fields in struct platform_device_info. > > > > That's why revert the commit which had been apparently done w/o reading > > the code. > > > > BugLink: https://github.com/andy-shev/linux/issues/20 > > Cc: Bhumika Goyal > > Cc: julia.lawall@lip6.fr > > Signed-off-by: Andy Shevchenko > > --- > > arch/x86/platform/intel-mid/device_libs/platform_bt.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/arch/x86/platform/intel-mid/device_libs/platform_bt.c b/arch/x86/platform/intel-mid/device_libs/platform_bt.c > > index dc036e511f48..5a0483e7bf66 100644 > > --- a/arch/x86/platform/intel-mid/device_libs/platform_bt.c > > +++ b/arch/x86/platform/intel-mid/device_libs/platform_bt.c > > @@ -60,7 +60,7 @@ static int __init tng_bt_sfi_setup(struct bt_sfi_data *ddata) > > return 0; > > } > > > > -static const struct bt_sfi_data tng_bt_sfi_data __initdata = { > > +static struct bt_sfi_data tng_bt_sfi_data __initdata = { > > .setup = tng_bt_sfi_setup, > > }; > > This is nasty, why didn't the compiler warn about this bug? > > Normally when using a const data structure for a non-const purpose. (Unless > there's a type cast which loses the type - one of the many reasons why type casts > should be avoided.) Indeed, because there is a cast: #define ICPU(model, ddata) \ { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (kernel_ulong_t)&ddata } static const struct x86_cpu_id bt_sfi_cpu_ids[] = { ICPU(INTEL_FAM6_ATOM_MERRIFIELD, tng_bt_sfi_data), {} }; julia