From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A0D13C25B08 for ; Sat, 20 Aug 2022 16:53:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345843AbiHTQw6 (ORCPT ); Sat, 20 Aug 2022 12:52:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57936 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230179AbiHTQwz (ORCPT ); Sat, 20 Aug 2022 12:52:55 -0400 Received: from conuserg-11.nifty.com (conuserg-11.nifty.com [210.131.2.78]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB92A356E9; Sat, 20 Aug 2022 09:52:53 -0700 (PDT) Received: from localhost.localdomain (133-32-182-133.west.xps.vectant.ne.jp [133.32.182.133]) (authenticated) by conuserg-11.nifty.com with ESMTP id 27KGpWBs018639; Sun, 21 Aug 2022 01:51:33 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-11.nifty.com 27KGpWBs018639 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1661014293; bh=Ih0ALdpIOTPB/Sn1mTKqVFaEpGzX4IPJIL6cfPyzDKs=; h=From:To:Cc:Subject:Date:From; b=FVi2J+uumSNsnyLx9bZCiOYwoPHt/3iuaKCxmj+L45yQLp8Few4zQXDsMj8nbB+D8 OfxNWScobUfm6Bjk4hyYlUI+nLy/7vn4Ewxkc1rDB7WJoSJSZHduwmgSUZmKt2aNdp Z3rl9YdgbrKpJKPh6lENFt0S5u9GMu+SUA91vlck3West0dP7VmLXtGqH7DlwQwu9q o78aD71BhLu5BM674qeSYAbY4KolOrxj7d3ZpKCbqd6VIc+3ae4zxT4pdSbj0mXZO0 LJgahdxAb2Lu+X5/zrqEIoLfGuprgLmil3BCtHORam/upm97d9F+qCC3tWKc1iwPO4 vAYRT5uIZKiKg== X-Nifty-SrcIP: [133.32.182.133] From: Masahiro Yamada To: Michael Ellerman , Nicholas Piggin , Christophe Leroy , linuxppc-dev@lists.ozlabs.org Cc: linux-kbuild@vger.kernel.org, Masahiro Yamada , linux-kernel@vger.kernel.org Subject: [PATCH] powerpc: align syscall table for ppc32 Date: Sun, 21 Aug 2022 01:51:29 +0900 Message-Id: <20220820165129.1147589-1-masahiroy@kernel.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christophe Leroy reported that commit 7b4537199a4a ("kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS") broke mpc85xx_defconfig + CONFIG_RELOCATABLE=y. LD vmlinux SYSMAP System.map SORTTAB vmlinux CHKREL vmlinux WARNING: 451 bad relocations c0b312a9 R_PPC_UADDR32 .head.text-0x3ff9ed54 c0b312ad R_PPC_UADDR32 .head.text-0x3ffac224 c0b312b1 R_PPC_UADDR32 .head.text-0x3ffb09f4 c0b312b5 R_PPC_UADDR32 .head.text-0x3fe184dc c0b312b9 R_PPC_UADDR32 .head.text-0x3fe183a8 ... The compiler emits a bunch of R_PPC_UADDR32, which is not supported by arch/powerpc/kernel/reloc_32.S. The reason is there exists an unaligned symbol. $ powerpc-linux-gnu-nm -n vmlinux ... c0b31258 d spe_aligninfo c0b31298 d __func__.0 c0b312a9 D sys_call_table c0b319b8 d __func__.0 Commit 7b4537199a4a is not the root cause. Even before that, I can reproduce the same issue for mpc85xx_defconfig + CONFIG_RELOCATABLE=y + CONFIG_MODVERSIONS=n. It is just that nobody did not notice it because when CONFIG_MODVERSIONS is enabled, a __crc_* symbol inserted before sys_call_table was hiding the unalignment issue. I checked the commit history, but I could not understand commit 46b45b10f142 ("[POWERPC] Align the sys_call_table"). It said 'Our _GLOBAL macro does a ".align 2" so the alignment is fine for 32 bit'. I checked the _GLOBAL in include/asm-powerpc/ppc_asm.h at that time. _GLOBAL specifies ".align 2" for ppc64, but no .align for ppc32. Commit c857c43b34ec ("powerpc: Don't use a function descriptor for system call table") removed _GLOBAL from the syscall table. Anyway, adding alignment to the syscall table for ppc32 fixes the issue. I am not giving Fixes tag because I do not know since when it has been broken, but presumably it has been for a long while. Link: https://lore.kernel.org/lkml/38605f6a-a568-f884-f06f-ea4da5b214f0@csgroup.eu/ Reported-by: Christophe Leroy Signed-off-by: Masahiro Yamada --- arch/powerpc/kernel/systbl.S | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/kernel/systbl.S b/arch/powerpc/kernel/systbl.S index cb3358886203..6c1db3b6de2d 100644 --- a/arch/powerpc/kernel/systbl.S +++ b/arch/powerpc/kernel/systbl.S @@ -18,6 +18,7 @@ .p2align 3 #define __SYSCALL(nr, entry) .8byte entry #else + .p2align 2 #define __SYSCALL(nr, entry) .long entry #endif -- 2.34.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1742CC25B08 for ; Sat, 20 Aug 2022 16:53:12 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4M94SQ3FDLz3d9w for ; Sun, 21 Aug 2022 02:53:10 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=nifty.com header.i=@nifty.com header.a=rsa-sha256 header.s=dec2015msa header.b=FVi2J+uu; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=softfail (domain owner discourages use of this host) smtp.mailfrom=kernel.org (client-ip=210.131.2.78; helo=conuserg-11.nifty.com; envelope-from=masahiroy@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=nifty.com header.i=@nifty.com header.a=rsa-sha256 header.s=dec2015msa header.b=FVi2J+uu; dkim-atps=neutral Received: from conuserg-11.nifty.com (conuserg-11.nifty.com [210.131.2.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4M94Rf1H93z3br0 for ; Sun, 21 Aug 2022 02:52:29 +1000 (AEST) Received: from localhost.localdomain (133-32-182-133.west.xps.vectant.ne.jp [133.32.182.133]) (authenticated) by conuserg-11.nifty.com with ESMTP id 27KGpWBs018639; Sun, 21 Aug 2022 01:51:33 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-11.nifty.com 27KGpWBs018639 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1661014293; bh=Ih0ALdpIOTPB/Sn1mTKqVFaEpGzX4IPJIL6cfPyzDKs=; h=From:To:Cc:Subject:Date:From; b=FVi2J+uumSNsnyLx9bZCiOYwoPHt/3iuaKCxmj+L45yQLp8Few4zQXDsMj8nbB+D8 OfxNWScobUfm6Bjk4hyYlUI+nLy/7vn4Ewxkc1rDB7WJoSJSZHduwmgSUZmKt2aNdp Z3rl9YdgbrKpJKPh6lENFt0S5u9GMu+SUA91vlck3West0dP7VmLXtGqH7DlwQwu9q o78aD71BhLu5BM674qeSYAbY4KolOrxj7d3ZpKCbqd6VIc+3ae4zxT4pdSbj0mXZO0 LJgahdxAb2Lu+X5/zrqEIoLfGuprgLmil3BCtHORam/upm97d9F+qCC3tWKc1iwPO4 vAYRT5uIZKiKg== X-Nifty-SrcIP: [133.32.182.133] From: Masahiro Yamada To: Michael Ellerman , Nicholas Piggin , Christophe Leroy , linuxppc-dev@lists.ozlabs.org Subject: [PATCH] powerpc: align syscall table for ppc32 Date: Sun, 21 Aug 2022 01:51:29 +0900 Message-Id: <20220820165129.1147589-1-masahiroy@kernel.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Masahiro Yamada , linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Christophe Leroy reported that commit 7b4537199a4a ("kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS") broke mpc85xx_defconfig + CONFIG_RELOCATABLE=y. LD vmlinux SYSMAP System.map SORTTAB vmlinux CHKREL vmlinux WARNING: 451 bad relocations c0b312a9 R_PPC_UADDR32 .head.text-0x3ff9ed54 c0b312ad R_PPC_UADDR32 .head.text-0x3ffac224 c0b312b1 R_PPC_UADDR32 .head.text-0x3ffb09f4 c0b312b5 R_PPC_UADDR32 .head.text-0x3fe184dc c0b312b9 R_PPC_UADDR32 .head.text-0x3fe183a8 ... The compiler emits a bunch of R_PPC_UADDR32, which is not supported by arch/powerpc/kernel/reloc_32.S. The reason is there exists an unaligned symbol. $ powerpc-linux-gnu-nm -n vmlinux ... c0b31258 d spe_aligninfo c0b31298 d __func__.0 c0b312a9 D sys_call_table c0b319b8 d __func__.0 Commit 7b4537199a4a is not the root cause. Even before that, I can reproduce the same issue for mpc85xx_defconfig + CONFIG_RELOCATABLE=y + CONFIG_MODVERSIONS=n. It is just that nobody did not notice it because when CONFIG_MODVERSIONS is enabled, a __crc_* symbol inserted before sys_call_table was hiding the unalignment issue. I checked the commit history, but I could not understand commit 46b45b10f142 ("[POWERPC] Align the sys_call_table"). It said 'Our _GLOBAL macro does a ".align 2" so the alignment is fine for 32 bit'. I checked the _GLOBAL in include/asm-powerpc/ppc_asm.h at that time. _GLOBAL specifies ".align 2" for ppc64, but no .align for ppc32. Commit c857c43b34ec ("powerpc: Don't use a function descriptor for system call table") removed _GLOBAL from the syscall table. Anyway, adding alignment to the syscall table for ppc32 fixes the issue. I am not giving Fixes tag because I do not know since when it has been broken, but presumably it has been for a long while. Link: https://lore.kernel.org/lkml/38605f6a-a568-f884-f06f-ea4da5b214f0@csgroup.eu/ Reported-by: Christophe Leroy Signed-off-by: Masahiro Yamada --- arch/powerpc/kernel/systbl.S | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/kernel/systbl.S b/arch/powerpc/kernel/systbl.S index cb3358886203..6c1db3b6de2d 100644 --- a/arch/powerpc/kernel/systbl.S +++ b/arch/powerpc/kernel/systbl.S @@ -18,6 +18,7 @@ .p2align 3 #define __SYSCALL(nr, entry) .8byte entry #else + .p2align 2 #define __SYSCALL(nr, entry) .long entry #endif -- 2.34.1