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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DF125C54E8D for ; Mon, 11 May 2020 13:37:26 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9D1ED20736 for ; Mon, 11 May 2020 13:37:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9D1ED20736 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=csgroup.eu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 49LMS35xzJzDqVC for ; Mon, 11 May 2020 23:37:23 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=csgroup.eu (client-ip=93.17.236.30; helo=pegase1.c-s.fr; envelope-from=christophe.leroy@csgroup.eu; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=csgroup.eu Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) (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 49LJXZ5TkYzDqgN for ; Mon, 11 May 2020 21:26:06 +1000 (AEST) Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 49LJXN67bmz9ty3h; Mon, 11 May 2020 13:25:56 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id FMgpJPev0u1O; Mon, 11 May 2020 13:25:56 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 49LJXN5GRCz9ty3g; Mon, 11 May 2020 13:25:56 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 6CD078B7B1; Mon, 11 May 2020 13:26:03 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id 9u1V3hauYpeT; Mon, 11 May 2020 13:26:03 +0200 (CEST) Received: from pc16570vm.idsi0.si.c-s.fr (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 313398B7AD; Mon, 11 May 2020 13:26:03 +0200 (CEST) Received: by pc16570vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 155AE65A09; Mon, 11 May 2020 11:26:03 +0000 (UTC) Message-Id: <907ff427c28e765d031687ef4eaf5667d73ea622.1589196133.git.christophe.leroy@csgroup.eu> In-Reply-To: References: From: Christophe Leroy Subject: [PATCH v3 36/45] powerpc/mm: Don't be too strict with _etext alignment on PPC32 To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman Date: Mon, 11 May 2020 11:26:03 +0000 (UTC) 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: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Similar to PPC64, accept to map RO data as ROX as a trade off between between security and memory usage. Having RO data executable is not a high risk as RO data can't be modified to forge an exploit. Signed-off-by: Christophe Leroy --- arch/powerpc/Kconfig | 26 -------------------------- arch/powerpc/kernel/vmlinux.lds.S | 3 +-- 2 files changed, 1 insertion(+), 28 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index f552726c9de2..970a5802850f 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -777,32 +777,6 @@ config THREAD_SHIFT Used to define the stack size. The default is almost always what you want. Only change this if you know what you are doing. -config ETEXT_SHIFT_BOOL - bool "Set custom etext alignment" if STRICT_KERNEL_RWX && \ - (PPC_BOOK3S_32 || PPC_8xx) - depends on ADVANCED_OPTIONS - help - This option allows you to set the kernel end of text alignment. When - RAM is mapped by blocks, the alignment needs to fit the size and - number of possible blocks. The default should be OK for most configs. - - Say N here unless you know what you are doing. - -config ETEXT_SHIFT - int "_etext shift" if ETEXT_SHIFT_BOOL - range 17 28 if STRICT_KERNEL_RWX && PPC_BOOK3S_32 - range 19 23 if STRICT_KERNEL_RWX && PPC_8xx - default 17 if STRICT_KERNEL_RWX && PPC_BOOK3S_32 - default 19 if STRICT_KERNEL_RWX && PPC_8xx - default PPC_PAGE_SHIFT - help - On Book3S 32 (603+), IBATs are used to map kernel text. - Smaller is the alignment, greater is the number of necessary IBATs. - - On 8xx, large pages (512kb or 8M) are used to map kernel linear - memory. Aligning to 8M reduces TLB misses as only 8M pages are used - in that case. - config DATA_SHIFT_BOOL bool "Set custom data alignment" if STRICT_KERNEL_RWX && \ (PPC_BOOK3S_32 || PPC_8xx) diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S index 31a0f201fb6f..54f23205c2b9 100644 --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -15,7 +15,6 @@ #include #define STRICT_ALIGN_SIZE (1 << CONFIG_DATA_SHIFT) -#define ETEXT_ALIGN_SIZE (1 << CONFIG_ETEXT_SHIFT) ENTRY(_stext) @@ -116,7 +115,7 @@ SECTIONS } :text - . = ALIGN(ETEXT_ALIGN_SIZE); + . = ALIGN(PAGE_SIZE); _etext = .; PROVIDE32 (etext = .); -- 2.25.0