From patchwork Mon Dec 2 11:37:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Heyi Guo X-Patchwork-Id: 11269057 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 78AEC13B6 for ; Mon, 2 Dec 2019 11:38:34 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 565F9217D7 for ; Mon, 2 Dec 2019 11:38:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="YubRw0WQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 565F9217D7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=O0TUXA6ly9Zse+l8XFRvwwijRwJDdj7CBK1pROrZgzc=; b=YubRw0WQ11Wd03 KyNROkcjXG+63VlDLACf8vuYL51IeXntEi66EKTjFf2AeKcJ8ONtWeCLZxrED1Emw88KXBcRw+bP/ G+om45Uys0Lq+oAxNi94Zn1xorDnphCpPHk9Xos2ZiJgd7AE2LjL/xuMHg1QWVqx7caYvSpGe+DHr BnKfwcvLZ5kIjC5E+7bnKoLSaglA6uz/EA2KwT2v7ieUQFDqWE9j5bB2tvrbghKo9kfMDMW9YgJPJ hz0a/49YGpIzIY7XllKX9mPACC1+YLfgzyUg8sRXwwXjDO0WqhLM6jyLr24XDCAr92BC157Tz3snX gWVf6xhpsDnrE4Iq6lqw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ibk2A-0006ir-2T; Mon, 02 Dec 2019 11:38:30 +0000 Received: from szxga04-in.huawei.com ([45.249.212.190] helo=huawei.com) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1ibk27-0006hv-AR for linux-arm-kernel@lists.infradead.org; Mon, 02 Dec 2019 11:38:29 +0000 Received: from DGGEMS413-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id A52C3DFD4CBD2B31D9A7; Mon, 2 Dec 2019 19:38:13 +0800 (CST) Received: from linux-XCyijm.huawei.com (10.175.104.212) by DGGEMS413-HUB.china.huawei.com (10.3.19.213) with Microsoft SMTP Server id 14.3.439.0; Mon, 2 Dec 2019 19:38:06 +0800 From: Heyi Guo To: , Subject: [PATCH] arm64/kernel/entry: refine comment of stack overflow check Date: Mon, 2 Dec 2019 19:37:02 +0800 Message-ID: <20191202113702.34158-1-guoheyi@huawei.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 X-Originating-IP: [10.175.104.212] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191202_033827_539651_3421EE2B X-CRM114-Status: GOOD ( 10.01 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [45.249.212.190 listed in list.dnswl.org] -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -0.0 SPF_PASS SPF: sender matches SPF record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Heyi Guo , wanghaibin.wang@huawei.com, Will Deacon , Catalin Marinas Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Stack overflow checking can be done by testing sp & (1 << THREAD_SHIFT) only for the stacks are aligned to (2 << THREAD_SHIFT) with size of (1 << THREAD_SIZE), and this is the case when CONFIG_VMAP_STACK is set. Fix the code comment to avoid confusion. Signed-off-by: Heyi Guo Cc: Catalin Marinas Cc: Will Deacon Acked-by: Mark Rutland --- arch/arm64/kernel/entry.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index cf3bd2976e57..9e8ba507090f 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -76,7 +76,8 @@ alternative_else_nop_endif #ifdef CONFIG_VMAP_STACK /* * Test whether the SP has overflowed, without corrupting a GPR. - * Task and IRQ stacks are aligned to (1 << THREAD_SHIFT). + * Task and IRQ stacks are aligned to (2 << THREAD_SHIFT) with size of + * (1 << THREAD_SHIFT). */ add sp, sp, x0 // sp' = sp + x0 sub x0, sp, x0 // x0' = sp' - x0 = (sp + x0) - x0 = sp