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 3F85FC4332F for ; Sat, 25 Sep 2021 05:17:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1DA1961151 for ; Sat, 25 Sep 2021 05:17:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343628AbhIYFSp (ORCPT ); Sat, 25 Sep 2021 01:18:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:50490 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230453AbhIYFSm (ORCPT ); Sat, 25 Sep 2021 01:18:42 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id EB6176127A; Sat, 25 Sep 2021 05:17:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1632547028; bh=dTWWEEku3Bu2EIy1EXAkhLeT4qw1irEelkTYP/6N8i8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uawpFkzY+arW26+J7Jtlm8z+jK4X7ZP8BRm7l8iOpBrvDceWt2q91g1LyisSX0mhF 5WVhZJwVYzbEPBegPG2WvWzdfT90scqgEOHhv3LVQda0FdrVJXkIJ0RJQZJbsIOQkK VrXdZC4vL9qpkP/hNS3uVioWg5N8LnkyQIt2kyzH+9KnWbxXmGZR/y0vwMSHJkio7w TIbpHPY4DsN1PuEL5mliPuMSL455rF4R1G4/DysZJ5v/Twzrib89WIclnGpFqDDVrE JuDoSp+PEOWkNRK+zVNAgWJ5tw/QgK4Df5cmpY3CErMQIpoSrCVKvW+roHqIg/yHqY KMXqA4+WHEPVQ== From: guoren@kernel.org To: guoren@kernel.org Cc: linux-kernel@vger.kernel.org, linux-csky@vger.kernel.org, Guo Ren , Al Viro , stable@vger.kernel.org Subject: [PATCH V2 2/2] csky: Fixup regs.sr broken in ptrace Date: Sat, 25 Sep 2021 13:16:47 +0800 Message-Id: <20210925051647.1162829-2-guoren@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210925051647.1162829-1-guoren@kernel.org> References: <20210925051647.1162829-1-guoren@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Guo Ren 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 --- arch/csky/kernel/ptrace.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/csky/kernel/ptrace.c b/arch/csky/kernel/ptrace.c index 0105ac81b432..1a5f54e0d272 100644 --- a/arch/csky/kernel/ptrace.c +++ b/arch/csky/kernel/ptrace.c @@ -99,7 +99,8 @@ static int gpr_set(struct task_struct *target, 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 -- 2.25.1