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 1F8BFC433EF for ; Mon, 13 Jun 2022 13:47:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379051AbiFMNq5 (ORCPT ); Mon, 13 Jun 2022 09:46:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40330 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379258AbiFMNn4 (ORCPT ); Mon, 13 Jun 2022 09:43:56 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B0D923EF28; Mon, 13 Jun 2022 04:31:54 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 0EC91B80EA7; Mon, 13 Jun 2022 11:31:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7AB3DC34114; Mon, 13 Jun 2022 11:31:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1655119911; bh=mnT08aQ9pGcT/TYriH3ev0VLk1IzDUDUxRReQgPBTWM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=let610Dsg6iWx6o2ssljQHcvx5e0VDj+pg7FljXX7ubjBFCtgswK2vm3ic8Re1K5t pk5Z5Dys8I6lZ6ScYrlf7msTKbGFo+h5k9eTXsiCgnCY+YJnExAOXG4zEbzslEhKEa siTM+2zzZHkQrSm2BnZ2GXzU8nWOt93Sbrd1qTo4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Erhard Furtner , Christophe Leroy , Michael Ellerman , Sasha Levin Subject: [PATCH 5.18 183/339] powerpc/kasan: Force thread size increase with KASAN Date: Mon, 13 Jun 2022 12:10:08 +0200 Message-Id: <20220613094932.228579127@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220613094926.497929857@linuxfoundation.org> References: <20220613094926.497929857@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Michael Ellerman [ Upstream commit 3e8635fb2e072672cbc650989ffedf8300ad67fb ] KASAN causes increased stack usage, which can lead to stack overflows. The logic in Kconfig to suggest a larger default doesn't work if a user has CONFIG_EXPERT enabled and has an existing .config with a smaller value. Follow the lead of x86 and arm64, and force the thread size to be increased when KASAN is enabled. That also has the effect of enlarging the stack for 64-bit KASAN builds, which is also desirable. Fixes: edbadaf06710 ("powerpc/kasan: Fix stack overflow by increasing THREAD_SHIFT") Reported-by: Erhard Furtner Reported-by: Christophe Leroy [mpe: Use MIN_THREAD_SHIFT as suggested by Christophe] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220601143114.133524-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin --- arch/powerpc/Kconfig | 1 - arch/powerpc/include/asm/thread_info.h | 10 ++++++++-- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 174edabb74fa..efb03d8d1f8b 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -771,7 +771,6 @@ config THREAD_SHIFT range 13 15 default "15" if PPC_256K_PAGES default "14" if PPC64 - default "14" if KASAN default "13" help Used to define the stack size. The default is almost always what you diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h index 125328d1b980..af58f1ed3952 100644 --- a/arch/powerpc/include/asm/thread_info.h +++ b/arch/powerpc/include/asm/thread_info.h @@ -14,10 +14,16 @@ #ifdef __KERNEL__ -#if defined(CONFIG_VMAP_STACK) && CONFIG_THREAD_SHIFT < PAGE_SHIFT +#ifdef CONFIG_KASAN +#define MIN_THREAD_SHIFT (CONFIG_THREAD_SHIFT + 1) +#else +#define MIN_THREAD_SHIFT CONFIG_THREAD_SHIFT +#endif + +#if defined(CONFIG_VMAP_STACK) && MIN_THREAD_SHIFT < PAGE_SHIFT #define THREAD_SHIFT PAGE_SHIFT #else -#define THREAD_SHIFT CONFIG_THREAD_SHIFT +#define THREAD_SHIFT MIN_THREAD_SHIFT #endif #define THREAD_SIZE (1 << THREAD_SHIFT) -- 2.35.1