Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 17 Mar 2003 10:11:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 17 Mar 2003 10:11:25 -0500 Received: from d12lmsgate.de.ibm.com ([194.196.100.234]:35067 "EHLO d12lmsgate.de.ibm.com") by vger.kernel.org with ESMTP id ; Mon, 17 Mar 2003 10:11:24 -0500 From: "BOEBLINGEN LINUX390" Importance: Normal Sensitivity: Subject: Re: [s390x] Patch for execve with a mode switch To: Pete Zaitcev Cc: linux-kernel@vger.kernel.org, zaitcev@redhat.com X-Mailer: Lotus Notes Release 5.0.8 June 18, 2001 Message-ID: Date: Mon, 17 Mar 2003 16:20:37 +0100 X-MIMETrack: Serialize by Router on D12ML016/12/M/IBM(Release 5.0.9a |January 7, 2002) at 17/03/2003 16:21:59 MIME-Version: 1.0 Content-type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1311 Lines: 31 Hi Pete, > If I boot an s390x kernel over a 31 bit userland, /sbin/init segfaults > in the dynamic linker. This happens because mm->free_area_cache > is set with TASK_UNMAPPED_BASE macro, which needs the TIF_31BIT > set right. Setting TIF_31BIT in ELF_PLAT_INIT is way too late > for this. mm->free_area_cache can't cause any problems on s390x because it isn't used. The idea behind mm->free_area_cache is to speed up the search in get_unmapped_area/arch_get_unmapped_area. But s390x defines its own version of arch_get_unmapped_area in arch/s390x/kernel/sys_s390.c which doesn't start the search at mm->free_area_cache. > The patch below basically ports what sparc64 does to s390x, > according to the Andrew Morton's comment in fs/binfmt_elf.c. > To tell the truth, I actually use equivalent of this on 2.4, > but I think it's important to get stock 2.5 right. This patch is severly broken. It wouldn't even compile. To make sure I retested the kernel 2.5.64 with the patches I sent to this list and ipled a 31 bit userland successfully. blue skies, Martin. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/