Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759203AbXEMGzn (ORCPT ); Sun, 13 May 2007 02:55:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757258AbXEMGzh (ORCPT ); Sun, 13 May 2007 02:55:37 -0400 Received: from nz-out-0506.google.com ([64.233.162.226]:49680 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757239AbXEMGzg (ORCPT ); Sun, 13 May 2007 02:55:36 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=tcCS3gKn3jts4NaZjSll2RwgI4PqCBh5CJz10XXd/NY0Wt/yxnSlZAEV6CrAZUCoUSvURzTmK1RMTdWdQO3WRblimDdNfn8SM/JwvsKsP39kax7a4YFxF61oxEeeY0p3j9IicY8G0JHRekVvTxMmBstC/pwZuJEnMkCqiCr+awc= Message-ID: <86802c440705122355r5f811d5bg2006b0b22ca885e6@mail.gmail.com> Date: Sat, 12 May 2007 23:55:34 -0700 From: "Yinghai Lu" To: "Eric W. Biederman" Subject: Re: [PATCH]x86_64: build and use GDT on copied compressed kernel Cc: "Andi Kleen" , "Andrew Morton" , "Vivek Goyal" , "Linux Kernel Mailing List" In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <86802c440705122233y327756e7te534199f46b2059d@mail.gmail.com> <86802c440705122329y27c6ef92v8cff43d52b99ae69@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2382 Lines: 48 On 5/12/07, Eric W. Biederman wrote: > > For data segments we never use that GDT, it is only for the code > segment we use the GDT and that only to get us into 64bit mode. > after the patch linux:/home/yhlu/xx/xx/kernel/linux-2.6/arch/x86_64/boot/compressed # readelf -e vmlinux ... Section Headers: [Nr] Name Type Address Offset Size EntSize Flags Link Info Align [ 0] NULL 0000000000000000 00000000 0000000000000000 0000000000000000 0 0 0 [ 1] .text PROGBITS 0000000000000000 00100000 000000000032617c 0000000000000000 AX 0 0 16 [ 2] .rodata PROGBITS 0000000000326180 00426180 0000000000000400 0000000000000000 A 0 0 32 [ 3] .eh_frame PROGBITS 0000000000326580 00426580 0000000000000210 0000000000000000 A 0 0 8 [ 4] .data PROGBITS 0000000000326790 00426790 0000000000000008 0000000000000000 WA 0 0 8 [ 5] .bss NOBITS 00000000003267a0 00426798 000000000000b860 0000000000000000 WA 0 0 32 [ 6] .comment PROGBITS 0000000000000000 00426798 0000000000000035 0000000000000000 0 0 1 [ 7] .shstrtab STRTAB 0000000000000000 004267cd 0000000000000047 0000000000000000 0 0 1 [ 8] .symtab SYMTAB 0000000000000000 00426a98 00000000000007c8 0000000000000018 9 60 8 [ 9] .strtab STRTAB 0000000000000000 00427260 0000000000000350 0000000000000000 0 0 1 Key to Flags: W (write), A (alloc), X (execute), M (merge), S (strings) I (info), L (link order), G (group), x (unknown) O (extra OS processing required) o (OS specific), p (processor specific) after the patch, it seems .data section size still have 8 bytes. before that will 0x28. don't know what are the 8 bytes. YH - 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/