Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752180AbZGLWYW (ORCPT ); Sun, 12 Jul 2009 18:24:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751971AbZGLWYP (ORCPT ); Sun, 12 Jul 2009 18:24:15 -0400 Received: from BISCAYNE-ONE-STATION.MIT.EDU ([18.7.7.80]:47268 "EHLO biscayne-one-station.mit.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751676AbZGLWYO (ORCPT ); Sun, 12 Jul 2009 18:24:14 -0400 Date: Sun, 12 Jul 2009 18:23:33 -0400 (EDT) From: Tim Abbott X-X-Sender: tabbott@vinegar-pot.mit.edu To: Sam Ravnborg cc: linux-kernel@vger.kernel.org, Paul Mundt , David Howells , Anders Kaseorg Subject: [PATCH] Restructure BSS linker script macros. Message-ID: User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Spam-Flag: NO X-Spam-Score: 0.00 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3580 Lines: 107 The BSS section macros in vmlinux.lds.h currently place the .sbss input section outside the bounds of [__bss_start, __bss_end]. On all architectures except for microblaze that handle both .sbss and __bss_start/__bss_end, this is wrong: the .sbss input section is within the range [__bss_start, __bss_end]. Relatedly, the example code at the top of the file actually has __bss_start/__bss_end defined twice; I believe the right fix here is to define them in the BSS_SECTION macro but not in the BSS macro. Another problem with the current macros is that several architectures have an ALIGN(4) or some other small number just before __bss_stop in their linker scripts. The BSS_SECTION macro currently hardcodes this to 4; while it should really be an argument. It also ignores its sbss_align argument; fix that. mn10300 is the only user at present of any of the macros touched by this patch. It looks like mn10300 actually was incorrectly converted to use the new BSS() macro (the alignment of 4 prior to conversion was a __bss_stop alignment, but the argument to the BSS macro is a start alignment). So fix this as well. I'd like acks from Sam and David on this one. Also CCing Paul, since he has a patch from me which will need to be updated to use BSS_SECTION(0, PAGE_SIZE, 4) once this gets merged. Signed-off-by: Tim Abbott Cc: Sam Ravnborg Cc: Paul Mundt Cc: David Howells --- arch/mn10300/kernel/vmlinux.lds.S | 2 +- include/asm-generic/vmlinux.lds.h | 19 +++++++++---------- 2 files changed, 10 insertions(+), 11 deletions(-) diff --git a/arch/mn10300/kernel/vmlinux.lds.S b/arch/mn10300/kernel/vmlinux.lds.S index c96ba3d..f4aa079 100644 --- a/arch/mn10300/kernel/vmlinux.lds.S +++ b/arch/mn10300/kernel/vmlinux.lds.S @@ -107,7 +107,7 @@ SECTIONS __init_end = .; /* freed after init ends here */ - BSS(4) + BSS_SECTION(0, PAGE_SIZE, 4) _end = . ; diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index a553f10..6ad76bf 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -30,9 +30,7 @@ * EXCEPTION_TABLE(...) * NOTES * - * __bss_start = .; - * BSS_SECTION(0, 0) - * __bss_stop = .; + * BSS_SECTION(0, 0, 0) * _end = .; * * /DISCARD/ : { @@ -489,7 +487,8 @@ * bss (Block Started by Symbol) - uninitialized data * zeroed during startup */ -#define SBSS \ +#define SBSS(sbss_align) \ + . = ALIGN(sbss_align); \ .sbss : AT(ADDR(.sbss) - LOAD_OFFSET) { \ *(.sbss) \ *(.scommon) \ @@ -498,12 +497,10 @@ #define BSS(bss_align) \ . = ALIGN(bss_align); \ .bss : AT(ADDR(.bss) - LOAD_OFFSET) { \ - VMLINUX_SYMBOL(__bss_start) = .; \ *(.bss.page_aligned) \ *(.dynbss) \ *(.bss) \ *(COMMON) \ - VMLINUX_SYMBOL(__bss_stop) = .; \ } /* @@ -735,8 +732,10 @@ INIT_RAM_FS \ } -#define BSS_SECTION(sbss_align, bss_align) \ - SBSS \ +#define BSS_SECTION(sbss_align, bss_align, stop_align) \ + . = ALIGN(sbss_align); \ + VMLINUX_SYMBOL(__bss_start) = .; \ + SBSS(sbss_align) \ BSS(bss_align) \ - . = ALIGN(4); - + . = ALIGN(stop_align); \ + VMLINUX_SYMBOL(__bss_stop) = .; -- 1.6.3.3 -- 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/