From patchwork Mon Mar 23 19:25:49 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: kyle mcmartin X-Patchwork-Id: 13814 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n2NJQFCJ028883 for ; Mon, 23 Mar 2009 19:26:15 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758501AbZCWT0P (ORCPT ); Mon, 23 Mar 2009 15:26:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758986AbZCWT0P (ORCPT ); Mon, 23 Mar 2009 15:26:15 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:56833 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758352AbZCWT0O (ORCPT ); Mon, 23 Mar 2009 15:26:14 -0400 Received: from kyle by bombadil.infradead.org with local (Exim 4.69 #1 (Red Hat Linux)) id 1LlpmP-0000B4-Fl; Mon, 23 Mar 2009 19:25:49 +0000 Date: Mon, 23 Mar 2009 15:25:49 -0400 From: Kyle McMartin To: torvalds@linux-foundation.org Cc: roland@redhat.com, aoliva@redhat.com, sam@ravnborg.org, linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org Subject: [PATCH] Build with -fno-dwarf2-cfi-asm Message-ID: <20090323192549.GA19208@bombadil.infradead.org> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org From: Kyle McMartin With a sufficiently new compiler and binutils, code which wasn't previously generating .eh_frame sections has begun to. Certain architectures (powerpc, in this case) may generate unexpected relocation formats in response to this, preventing modules from loading. While the new relocation types should probably be handled, revert to the previous behaviour with regards to generation of .eh_frame sections. (This was reported against Fedora, which appears to be the only distro doing any building against gcc-4.4 at present: RH bz#486545.) Signed-off-by: Kyle McMartin Cc: roland@redhat.com Cc: aoliva@redhat.com Cc: sam@ravnborg.org --- As near as I can tell, the only case previously was for the vdso images, which are explicitly built with -fasynchronous-unwind-tables, and annotated with cfi directives. Everyone else either unwinds their stack manually, or has a custom unwind format like parisc or ia64. Hopefully this is a somewhat better description than the last time. cheers, Kyle -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/Makefile b/Makefile index a2c2efe..057230a 100644 --- a/Makefile +++ b/Makefile @@ -569,6 +569,9 @@ KBUILD_CFLAGS += $(call cc-option,-Wno-pointer-sign,) # disable invalid "can't wrap" optimzations for signed / pointers KBUILD_CFLAGS += $(call cc-option,-fwrapv) +# revert to pre-gcc-4.4 behaviour of .eh_frame +KBUILD_CFLAGS += $(call cc-option,-fno-dwarf2-cfi-asm) + # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments # But warn user when we do so warn-assign = \