From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754193AbZHZWhq (ORCPT ); Wed, 26 Aug 2009 18:37:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754118AbZHZWhp (ORCPT ); Wed, 26 Aug 2009 18:37:45 -0400 Received: from host0.dyn.jankratochvil.net ([89.250.240.59]:36676 "EHLO host0.dyn.jankratochvil.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754078AbZHZWho (ORCPT ); Wed, 26 Aug 2009 18:37:44 -0400 X-Greylist: delayed 375 seconds by postgrey-1.27 at vger.kernel.org; Wed, 26 Aug 2009 18:37:43 EDT Date: Thu, 27 Aug 2009 00:31:26 +0200 From: Jan Kratochvil To: linux-kernel@vger.kernel.org Subject: [patch] Fix vdso32 relocation for paddr Message-ID: <20090826223126.GA20373@host0.dyn.jankratochvil.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, `readelf -Wl file-dumped-from-/proc/self/maps-[vdso]' for x86_64 process prints: Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align LOAD 0x000000 0xffffffffff700000 0xffffffffff700000 0x000890 0x000890 R E 0x1000 DYNAMIC 0x000410 0xffffffffff700410 0xffffffffff700410 0x0000f0 0x0000f0 R 0x8 NOTE 0x0002d0 0xffffffffff7002d0 0xffffffffff7002d0 0x00003c 0x00003c R 0x4 GNU_EH_FRAME 0x00030c 0xffffffffff70030c 0xffffffffff70030c 0x000034 0x000034 R 0x4 while such dump for i386 process prints: Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align LOAD 0x000000 0xffffe000 0x00000000 0x00434 0x00434 R E 0x1000 DYNAMIC 0x000350 0xffffe350 0x00000350 0x00078 0x00078 R 0x4 NOTE 0x0001c4 0xffffe1c4 0x000001c4 0x00060 0x00060 R 0x4 GNU_EH_FRAME 0x000224 0xffffe224 0x00000224 0x00024 0x00024 R 0x4 The mapped location can be arbirary (according to the rules of PIC - Position Independent Code) but currently the i386 vdso (vdso32) looks as an overlayed code as it has LMA != VMA (rule contained in GDB function section_is_overlay, as suggested by Daniel Jacobowitz). Fixed vdso32 prints: Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align LOAD 0x000000 0xffffe000 0xffffe000 0x00434 0x00434 R E 0x1000 DYNAMIC 0x000350 0xffffe350 0xffffe350 0x00078 0x00078 R 0x4 NOTE 0x0001c4 0xffffe1c4 0xffffe1c4 0x00060 0x00060 R 0x4 GNU_EH_FRAME 0x000224 0xffffe224 0xffffe224 0x00024 0x00024 R 0x4 It required now a workaround in GDB patch so at least to fix it in Linux kernel: http://sourceware.org/ml/gdb-patches/2009-08/msg00437.html Thanks, Jan Signed-off-by: Jan Kratochvil --- linux-2.6.30.x86_64/arch/x86/vdso/vdso32-setup.c-orig 2009-08-26 22:23:08.000000000 +0200 +++ linux-2.6.30.x86_64/arch/x86/vdso/vdso32-setup.c 2009-08-26 22:38:10.000000000 +0200 @@ -172,6 +172,7 @@ static __init void relocate_vdso(Elf32_E phdr = (void *)ehdr + ehdr->e_phoff; for (i = 0; i < ehdr->e_phnum; i++) { phdr[i].p_vaddr += VDSO_ADDR_ADJUST; + phdr[i].p_paddr += VDSO_ADDR_ADJUST; /* relocate dynamic stuff */ if (phdr[i].p_type == PT_DYNAMIC)