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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 6541DC433E6 for ; Tue, 22 Dec 2020 13:30:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36F7423105 for ; Tue, 22 Dec 2020 13:30:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727227AbgLVN3x (ORCPT ); Tue, 22 Dec 2020 08:29:53 -0500 Received: from pegase1.c-s.fr ([93.17.236.30]:13722 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726741AbgLVN3w (ORCPT ); Tue, 22 Dec 2020 08:29:52 -0500 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4D0cbz0RVXz9v15b; Tue, 22 Dec 2020 14:28:31 +0100 (CET) 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 gP_3aVByMkaD; Tue, 22 Dec 2020 14:28:30 +0100 (CET) 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 4D0cby6TzLz9v15V; Tue, 22 Dec 2020 14:28:30 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 3DE848B81B; Tue, 22 Dec 2020 14:28:32 +0100 (CET) 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 vhUoz-SbdbH4; Tue, 22 Dec 2020 14:28:32 +0100 (CET) Received: from po17688vm.idsi0.si.c-s.fr (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id E74EF8B812; Tue, 22 Dec 2020 14:28:31 +0100 (CET) Received: by po17688vm.idsi0.si.c-s.fr (Postfix, from userid 0) id C678066969; Tue, 22 Dec 2020 13:28:31 +0000 (UTC) Message-Id: <5ed8f2e128812ddd6c4f8747f86a3410a8873a61.1608641533.git.christophe.leroy@csgroup.eu> In-Reply-To: References: From: Christophe Leroy Subject: [PATCH v1 09/15] powerpc/32: Preserve cr1 in exception prolog stack check To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , npiggin@gmail.com Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Date: Tue, 22 Dec 2020 13:28:31 +0000 (UTC) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org THREAD_ALIGN_SHIFT = THREAD_SHIFT + 1 = PAGE_SHIFT + 1 Maximum PAGE_SHIFT is 18 for 256k pages so THREAD_ALIGN_SHIFT is 19 at the maximum. No need to clobber cr1, it can be preserved when moving r1 into CR when we check stack overflow. Signed-off-by: Christophe Leroy --- arch/powerpc/kernel/head_6xx_8xx.h | 2 +- arch/powerpc/kernel/head_book3s_32.S | 6 ------ 2 files changed, 1 insertion(+), 7 deletions(-) diff --git a/arch/powerpc/kernel/head_6xx_8xx.h b/arch/powerpc/kernel/head_6xx_8xx.h index 0e4ce6746443..b70d50efc961 100644 --- a/arch/powerpc/kernel/head_6xx_8xx.h +++ b/arch/powerpc/kernel/head_6xx_8xx.h @@ -47,7 +47,7 @@ lwz r1,TASK_STACK-THREAD(r1) addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE 1: - mtcrf 0x7f, r1 + mtcrf 0x3f, r1 bt 32 - THREAD_ALIGN_SHIFT, stack_overflow #else subi r11, r1, INT_FRAME_SIZE /* use r1 if kernel */ diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S index ccc691d67b0c..89f38e9ec7cc 100644 --- a/arch/powerpc/kernel/head_book3s_32.S +++ b/arch/powerpc/kernel/head_book3s_32.S @@ -276,12 +276,6 @@ MachineCheck: 7: EXCEPTION_PROLOG_2 addi r3,r1,STACK_FRAME_OVERHEAD #ifdef CONFIG_PPC_CHRP -#ifdef CONFIG_VMAP_STACK - mfspr r4, SPRN_SPRG_THREAD - tovirt(r4, r4) - lwz r4, RTAS_SP(r4) - cmpwi cr1, r4, 0 -#endif beq cr1, machine_check_tramp twi 31, 0, 0 #else -- 2.25.0