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 7DCBCC433EF for ; Mon, 18 Oct 2021 13:50:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6856160555 for ; Mon, 18 Oct 2021 13:50:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233998AbhJRNwQ (ORCPT ); Mon, 18 Oct 2021 09:52:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:47682 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233947AbhJRNuJ (ORCPT ); Mon, 18 Oct 2021 09:50:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A107D61875; Mon, 18 Oct 2021 13:37:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1634564267; bh=9jRwUoPbWPn0/D5vnNzpLm9PGuycKAtL5UHDwHXvofs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gqWHyaw2naz2zRIZZShwAsseSB7rlesVkeTIZL9nFJGWfbuMOZOESkoqDbD8+uYzv uRqNjszu7ECXEoI1gH5GYUwkjVhQJqfDesNipgxYuQ0rCxSLJCrDJZZNbU8rF3bqe9 hc86Ai2jJ2dsyh1IZ2cLpcLdsHCeZ768Uklm5K3s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Guo Ren , Al Viro Subject: [PATCH 5.14 024/151] csky: Fixup regs.sr broken in ptrace Date: Mon, 18 Oct 2021 15:23:23 +0200 Message-Id: <20211018132341.466668426@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211018132340.682786018@linuxfoundation.org> References: <20211018132340.682786018@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: linux-kernel@vger.kernel.org From: Guo Ren commit af89ebaa64de726ca0a39bbb0bf0c81a1f43ad50 upstream. gpr_get() return the entire pt_regs (include sr) to userspace, if we don't restore the C bit in gpr_set, it may break the ALU result in that context. So the C flag bit is part of gpr context, that's why riscv totally remove the C bit in the ISA. That makes sr reg clear from userspace to supervisor privilege. Signed-off-by: Guo Ren Cc: Al Viro Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- arch/csky/kernel/ptrace.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/csky/kernel/ptrace.c +++ b/arch/csky/kernel/ptrace.c @@ -99,7 +99,8 @@ static int gpr_set(struct task_struct *t if (ret) return ret; - regs.sr = task_pt_regs(target)->sr; + /* BIT(0) of regs.sr is Condition Code/Carry bit */ + regs.sr = (regs.sr & BIT(0)) | (task_pt_regs(target)->sr & ~BIT(0)); #ifdef CONFIG_CPU_HAS_HILO regs.dcsr = task_pt_regs(target)->dcsr; #endif