From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752148AbeA2X5l (ORCPT ); Mon, 29 Jan 2018 18:57:41 -0500 Received: from pandora.armlinux.org.uk ([78.32.30.218]:37318 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751853AbeA2X5Z (ORCPT ); Mon, 29 Jan 2018 18:57:25 -0500 Date: Mon, 29 Jan 2018 23:57:11 +0000 From: Russell King - ARM Linux To: Anders Roxell Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, arnd@arndb.de Subject: Re: [PATCH] arch/arm/Kconfig: enable ARM_MODULE_PLTS when LOCKDEP=y Message-ID: <20180129235710.GA9418@n2100.armlinux.org.uk> References: <20180129234900.11121-1-anders.roxell@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180129234900.11121-1-anders.roxell@linaro.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 30, 2018 at 12:49:00AM +0100, Anders Roxell wrote: > While testing multi_v7_defconfig with LOCKDEP enabled, the kernel > fails to load simple modules, as reported by kselftest: > > [ 34.107620] test_printf: section 4 reloc 2 sym 'memset': relocation > 28 out of range (0xbf046044 -> 0xc109f720) > selftests: printf.sh [FAIL] > > The problem that is seen when LOCKDEP is enabled without > ARM_MODULE_PLTS, is that LOCKDEP eats so much memory that the top of the > kernel gets out of reach from the bottom of the module area. This really doesn't follow IMHO - enabling various features can cause this, and we're not going to end up stuffing the Kconfig full of these select statements each time we find a combination of Kconfig symbols that cause it. lockdep isn't that special - I can (and do) build kernels with lockdep enabled, with modules, and I do not run into this problem. So it's not as simple as you make out in this commit description. It's likely that you have either a fairly full kernel configuration (it must be to place memset() more than 16MB) or you are not placing the kernel at 0xc0008000 due to memory reservations in the low memory. > Suggested-by: Arnd Bergmann I guess this was discussed privately with Arnd, since there's no record of the discussion on the lists - which is even more reason why the commit message needs to describe better why you need this change. > Signed-off-by: Anders Roxell > --- > arch/arm/Kconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index 51c8df561077..a339157497c6 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -20,6 +20,7 @@ config ARM > select ARCH_USE_BUILTIN_BSWAP > select ARCH_USE_CMPXCHG_LOCKREF > select ARCH_WANT_IPC_PARSE_VERSION > + select ARM_MODULE_PLTS if LOCKDEP > select BUILDTIME_EXTABLE_SORT if MMU > select CLONE_BACKWARDS > select CPU_PM if (SUSPEND || CPU_IDLE) > -- > 2.11.0 > -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up According to speedtest.net: 8.21Mbps down 510kbps up