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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75D93C38147 for ; Wed, 18 Jan 2023 17:17:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230518AbjARRRF (ORCPT ); Wed, 18 Jan 2023 12:17:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231175AbjARRQ4 (ORCPT ); Wed, 18 Jan 2023 12:16:56 -0500 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3B6324E529; Wed, 18 Jan 2023 09:16:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=UiaXdyQfqOt+6WwaLnuzqkN2uc7Go0jhzWYcMdFqIEU=; b=HqOF5yLycZqDpix07Wa88U3B5z PV+/OuawmGvHXon+V/NTHJO4/hAbMGN4g/ngBlG1PxYXFmW3biP2WJviIM5ke7Ipp6ssbdY7YRUki sTvKtZLK5hHgUk9IahRiPHErAzQhRSnAErMtzdP17+tHybH3AeIdYLBo/DcnAzBSO6pkkfID7e9Ke Is6/xXp8olzFV5cJU7Buzu91LCDft1CQx1FD6SXygcfJqiHQj05Ovli4iFSsDM3j1eqyFix6iFNhr SJt3QCrObUHCcDwUwwJmBO6hLfVVE9OVRCjEk2OlSCXHBb5OANTpBps1L8ypjUEVZZzbCbDnOV7T4 IW0JVL2Q==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1pIC2Y-0003H1-1h; Wed, 18 Jan 2023 17:15:59 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 22EE8300094; Wed, 18 Jan 2023 18:16:23 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id D7DC920B2B4E5; Wed, 18 Jan 2023 18:16:23 +0100 (CET) Date: Wed, 18 Jan 2023 18:16:23 +0100 From: Peter Zijlstra To: Gregory Price Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, krisman@collabora.com, tglx@linutronix.de, luto@kernel.org, oleg@redhat.com, ebiederm@xmission.com, akpm@linux-foundation.org, adobriyan@gmail.com, corbet@lwn.net, shuah@kernel.org, Gregory Price Subject: Re: [PATCH 1/3] ptrace,syscall_user_dispatch: Implement Syscall User Dispatch Suspension Message-ID: References: <20230109153348.5625-1-gregory.price@memverge.com> <20230109153348.5625-2-gregory.price@memverge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230109153348.5625-2-gregory.price@memverge.com> Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On Mon, Jan 09, 2023 at 10:33:46AM -0500, Gregory Price wrote: > @@ -36,6 +37,10 @@ bool syscall_user_dispatch(struct pt_regs *regs) > struct syscall_user_dispatch *sd = ¤t->syscall_dispatch; > char state; > > + if (IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) && > + unlikely(current->ptrace & PT_SUSPEND_SYSCALL_USER_DISPATCH)) > + return false; > + > if (likely(instruction_pointer(regs) - sd->offset < sd->len)) > return false; > So by making syscall_user_dispatch() return false, we'll make syscall_trace_enter() continue to handle things, and supposedly you want to land in ptrace_report_syscall_entry(), right? > diff --git a/kernel/ptrace.c b/kernel/ptrace.c > index 54482193e1ed..a6ad815bd4be 100644 > --- a/kernel/ptrace.c > +++ b/kernel/ptrace.c > @@ -370,6 +370,11 @@ static int check_ptrace_options(unsigned long data) > if (data & ~(unsigned long)PTRACE_O_MASK) > return -EINVAL; > > + if (unlikely(data & PTRACE_O_SUSPEND_SYSCALL_USER_DISPATCH)) { > + if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTART)) > + return -EINVAL; > + } Should setting this then not also depend on having SYSCALL_WORK_SYSCALL_TRACE set? Because without that, you get 'funny' things.