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 X-Spam-Level: X-Spam-Status: No, score=-14.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 714FCC2D0A3 for ; Mon, 26 Oct 2020 12:52:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3D39D20759 for ; Mon, 26 Oct 2020 12:52:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="IXmW3I6N"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="ETCvjm1e" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1775716AbgJZMwv (ORCPT ); Mon, 26 Oct 2020 08:52:51 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:39844 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1775668AbgJZMwj (ORCPT ); Mon, 26 Oct 2020 08:52:39 -0400 Date: Mon, 26 Oct 2020 12:52:37 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1603716758; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/xrKcqz2UIwg/Q8cfRTWfEHLz8qfVeEVrJfwrDBxk8E=; b=IXmW3I6N6Go0MBOF16Yy/M22Rs+s/GOe+y98ZTFmVWdKGPcwOgR6OX/hbhEGqRn/NIAMAJ i9EvCUUb2g+abMf51Ul1xXaMF4n6UMSs+7wB/SlHVva3uh52QqfD603IC73N+KcAW7jEoQ C7HjQOfZwAvpjhlSpcYHHAByxjNFiCdlEbc+/kP0rW95KYH7/KsDi7/ifw1ajZ45e9xXh3 CiIJxqxTyELe0r81T88T7+saJK6OUuQNufhYl/85idHgsu0BMRSbbXy2kO/pftBXWnz7b7 CfhyDHj0M3Azvrca0fkdronbyw3hsJP0vNTolQ/nVjMWBnwSeXud9BgdjKdu6g== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1603716758; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/xrKcqz2UIwg/Q8cfRTWfEHLz8qfVeEVrJfwrDBxk8E=; b=ETCvjm1eLcJQa16RhO1rlCLOB3YGujn/9nBVJeC3JSs8FMRsE5v78NIHxGdwS2lEOsaGCB ueYORWrpXE5E0wBg== From: "tip-bot2 for Gabriel Krisman Bertazi" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/cleanups] x86/compat: Simplify compat syscall userspace allocation Cc: Andy Lutomirski , Gabriel Krisman Bertazi , Thomas Gleixner , x86 , LKML In-Reply-To: <20201004032536.1229030-3-krisman@collabora.com> References: <20201004032536.1229030-3-krisman@collabora.com> MIME-Version: 1.0 Message-ID: <160371675721.397.3164323953920306327.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/cleanups branch of tip: Commit-ID: 214f0e804358cdd13b5cbe4445189f23e30618b4 Gitweb: https://git.kernel.org/tip/214f0e804358cdd13b5cbe4445189f23e30618b4 Author: Gabriel Krisman Bertazi AuthorDate: Sat, 03 Oct 2020 23:25:28 -04:00 Committer: Thomas Gleixner CommitterDate: Mon, 26 Oct 2020 13:46:46 +01:00 x86/compat: Simplify compat syscall userspace allocation When allocating user memory space for a compat system call, don't consider whether the originating code is IA32 or X32, just allocate from a safe region for both, beyond the redzone. This should be safe for IA32, and has the benefit of avoiding TIF_IA32, which is about to be removed. Suggested-by: Andy Lutomirski Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20201004032536.1229030-3-krisman@collabora.com --- arch/x86/include/asm/compat.h | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h index 0e327a0..f145e33 100644 --- a/arch/x86/include/asm/compat.h +++ b/arch/x86/include/asm/compat.h @@ -177,14 +177,13 @@ typedef struct user_regs_struct compat_elf_gregset_t; static inline void __user *arch_compat_alloc_user_space(long len) { - compat_uptr_t sp; - - if (test_thread_flag(TIF_IA32)) { - sp = task_pt_regs(current)->sp; - } else { - /* -128 for the x32 ABI redzone */ - sp = task_pt_regs(current)->sp - 128; - } + compat_uptr_t sp = task_pt_regs(current)->sp; + + /* + * -128 for the x32 ABI redzone. For IA32, it is not strictly + * necessary, but not harmful. + */ + sp -= 128; return (void __user *)round_down(sp - len, 16); }