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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DB85DC433EF for ; Tue, 9 Nov 2021 01:28:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C90CF610A8 for ; Tue, 9 Nov 2021 01:28:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243807AbhKIBbE (ORCPT ); Mon, 8 Nov 2021 20:31:04 -0500 Received: from mail.kernel.org ([198.145.29.99]:50114 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244217AbhKIBY7 (ORCPT ); Mon, 8 Nov 2021 20:24:59 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id B364661B3F; Tue, 9 Nov 2021 01:09:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1636420174; bh=/0LBGR/tDVCf/txDBVm2oikXt0vZaDQ4+mz7fcuQWJw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VaXquggLgZq1T2XU2GhLm5B9Ontc2ufgnBM7YCc+nU8xxSFv4P9YPADHZ5ZsdGXfj lpZe4RwBEEvKKH/Rh5gfOGeMonfuqD/sMXhmOmqbyDjOqkyEeex5EwmciNgcRgN7Mf FbfgIApQ+4qRXnuDskfSWoJmVIxNYf3z/fVs0DGidwrcaCK44BpBv3mnnJoKNsUzog xVW9i8Xo/qY5Ed+1a77UXslk7TDENlRCDov5/37CIjYYYORbM3KAgaeq9s9ZbZIvo/ wBDkcg7a8xAGmYkcY5kSPgTaNsDEzRiFl2H4FTkRzDyprVsfwDiRIhPjZ4UAXJ7PL0 MlUEzkxCpGHNQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Peter Zijlstra , Michael Wang , Sasha Levin , tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, adobriyan@gmail.com, luto@kernel.org Subject: [PATCH AUTOSEL 4.4 08/30] x86: Increase exception stack sizes Date: Mon, 8 Nov 2021 20:08:56 -0500 Message-Id: <20211109010918.1192063-8-sashal@kernel.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211109010918.1192063-1-sashal@kernel.org> References: <20211109010918.1192063-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Zijlstra [ Upstream commit 7fae4c24a2b84a66c7be399727aca11e7a888462 ] It turns out that a single page of stack is trivial to overflow with all the tracing gunk enabled. Raise the exception stacks to 2 pages, which is still half the interrupt stacks, which are at 4 pages. Reported-by: Michael Wang Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/YUIO9Ye98S5Eb68w@hirez.programming.kicks-ass.net Signed-off-by: Sasha Levin --- arch/x86/include/asm/page_64_types.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h index fb1251946b45e..67a140d77f336 100644 --- a/arch/x86/include/asm/page_64_types.h +++ b/arch/x86/include/asm/page_64_types.h @@ -15,7 +15,7 @@ #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER) #define CURRENT_MASK (~(THREAD_SIZE - 1)) -#define EXCEPTION_STACK_ORDER (0 + KASAN_STACK_ORDER) +#define EXCEPTION_STACK_ORDER (1 + KASAN_STACK_ORDER) #define EXCEPTION_STKSZ (PAGE_SIZE << EXCEPTION_STACK_ORDER) #define DEBUG_STACK_ORDER (EXCEPTION_STACK_ORDER + 1) -- 2.33.0