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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 A129CC433B4 for ; Mon, 10 May 2021 18:53:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 69D7661494 for ; Mon, 10 May 2021 18:53:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233149AbhEJSy4 (ORCPT ); Mon, 10 May 2021 14:54:56 -0400 Received: from terminus.zytor.com ([198.137.202.136]:37861 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232789AbhEJSyq (ORCPT ); Mon, 10 May 2021 14:54:46 -0400 Received: from tazenda.hos.anvin.org ([IPv6:2601:646:8602:8be0:7285:c2ff:fefb:fd4]) (authenticated bits=0) by mail.zytor.com (8.16.1/8.15.2) with ESMTPSA id 14AIrNli2459085 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Mon, 10 May 2021 11:53:33 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 14AIrNli2459085 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2021042801; t=1620672813; bh=JHPMbGMh79H+cjWsMsA8mi8L+qKBD13Dnd8qkFhJLEs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=orfPQg52ynpp6lA+HdEOWMgTL2lQkJdgEz6MT3x5zJoJjPJtPRzPSr4venJ9IFAuv 5KM+DSSWXtmqopsxBIeo8cFVPZn4RCS0c19Q6yXwebUBaa/2DIlZerazHIK0psKHKb GE68TArtjQEDH9vRCapm1QdUTXZi1ARZ3/ucE2GqOD5wW93rMJMWIgj9sTxIb9CbYZ n2yH14KoCC5zJ9TAxtSPPg2oGxcifC4+QCHd89SNCiHbLFrtQrvCAGUcF/iRRNWS0O hKRJmCXuFFoSExA9Tic6QCpvUGz7vjAG5t9xWoqdl50iNFdbYTalTLMH01QyI7oh/H 731/8EmOnBCNQ== From: "H. Peter Anvin" To: Ingo Molnar , Thomas Gleixner , Borislav Petkov , Andy Lutomirski Cc: "H. Peter Anvin" , Linux Kernel Mailing List Subject: [RFC v2 PATCH 6/7] x86/regs: syscall_get_nr() returns -1 for a non-system call Date: Mon, 10 May 2021 11:53:15 -0700 Message-Id: <20210510185316.3307264-7-hpa@zytor.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210510185316.3307264-1-hpa@zytor.com> References: <20210510185316.3307264-1-hpa@zytor.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org syscall_get_nr() is defined to return -1 for a non-system call or a ptrace/seccomp restart; not just any arbitrary number. See comment in for the official definition of this function. Signed-off-by: H. Peter Anvin --- arch/x86/kernel/ptrace.c | 2 +- arch/x86/kernel/signal.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 87a4143aa7d7..4c208ea3bd9f 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -911,7 +911,7 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 value) * syscall with TS_COMPAT still set. */ regs->orig_ax = value; - if (syscall_get_nr(child, regs) >= 0) + if (syscall_get_nr(child, regs) != -1) child->thread_info.status |= TS_I386_REGS_POKED; break; diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index a06cb107c0e8..e12779a2714d 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -713,7 +713,7 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs) save_v86_state((struct kernel_vm86_regs *) regs, VM86_SIGNAL); /* Are we from a system call? */ - if (syscall_get_nr(current, regs) >= 0) { + if (syscall_get_nr(current, regs) != -1) { /* If so, check system call restarting.. */ switch (syscall_get_error(current, regs)) { case -ERESTART_RESTARTBLOCK: @@ -793,7 +793,7 @@ void arch_do_signal_or_restart(struct pt_regs *regs, bool has_signal) } /* Did we come from a system call? */ - if (syscall_get_nr(current, regs) >= 0) { + if (syscall_get_nr(current, regs) != -1) { /* Restart the system call - no handlers present */ switch (syscall_get_error(current, regs)) { case -ERESTARTNOHAND: -- 2.31.1