From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oleg Nesterov Subject: Re: [PATCH v4 3/5] x86: Split syscall_trace_enter into two phases Date: Tue, 29 Jul 2014 21:25:55 +0200 Message-ID: <20140729192555.GB6308@redhat.com> References: <714cf438762d342673b3b131d5c90bc69ca921a9.1406604806.git.luto@amacapital.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <714cf438762d342673b3b131d5c90bc69ca921a9.1406604806.git.luto@amacapital.net> Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-subscribe: List-owner: List-post: List-archive: To: Andy Lutomirski Cc: linux-kernel@vger.kernel.org, Kees Cook , Will Drewry , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org, linux-arch@vger.kernel.org, linux-security-module@vger.kernel.org, Alexei Starovoitov , hpa@zytor.com, Frederic Weisbecker List-Id: linux-arch.vger.kernel.org On 07/28, Andy Lutomirski wrote: > > +long syscall_trace_enter_phase2(struct pt_regs *regs, u32 arch, > + unsigned long phase1_result) > +{ > + long ret = 0; > + u32 work = ACCESS_ONCE(current_thread_info()->flags) & > + _TIF_WORK_SYSCALL_ENTRY; > + > + BUG_ON(regs != task_pt_regs(current)); > > /* > * If we stepped into a sysenter/syscall insn, it trapped in > @@ -1463,17 +1569,20 @@ long syscall_trace_enter(struct pt_regs *regs) > * do_debug() and we need to set it again to restore the user > * state. If we entered on the slow path, TF was already set. > */ > - if (test_thread_flag(TIF_SINGLESTEP)) > + if (work & _TIF_SINGLESTEP) > regs->flags |= X86_EFLAGS_TF; This is minor, I won't argue, but this can be moved into phase1(), afaics. Oleg. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:58025 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751693AbaG2T2O (ORCPT ); Tue, 29 Jul 2014 15:28:14 -0400 Date: Tue, 29 Jul 2014 21:25:55 +0200 From: Oleg Nesterov Subject: Re: [PATCH v4 3/5] x86: Split syscall_trace_enter into two phases Message-ID: <20140729192555.GB6308@redhat.com> References: <714cf438762d342673b3b131d5c90bc69ca921a9.1406604806.git.luto@amacapital.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <714cf438762d342673b3b131d5c90bc69ca921a9.1406604806.git.luto@amacapital.net> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Andy Lutomirski Cc: linux-kernel@vger.kernel.org, Kees Cook , Will Drewry , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org, linux-arch@vger.kernel.org, linux-security-module@vger.kernel.org, Alexei Starovoitov , hpa@zytor.com, Frederic Weisbecker Message-ID: <20140729192555.eiVjt0vSjFEZ-iQAtjLSIutYGJ8gasTOpTjO4V_ioYY@z> On 07/28, Andy Lutomirski wrote: > > +long syscall_trace_enter_phase2(struct pt_regs *regs, u32 arch, > + unsigned long phase1_result) > +{ > + long ret = 0; > + u32 work = ACCESS_ONCE(current_thread_info()->flags) & > + _TIF_WORK_SYSCALL_ENTRY; > + > + BUG_ON(regs != task_pt_regs(current)); > > /* > * If we stepped into a sysenter/syscall insn, it trapped in > @@ -1463,17 +1569,20 @@ long syscall_trace_enter(struct pt_regs *regs) > * do_debug() and we need to set it again to restore the user > * state. If we entered on the slow path, TF was already set. > */ > - if (test_thread_flag(TIF_SINGLESTEP)) > + if (work & _TIF_SINGLESTEP) > regs->flags |= X86_EFLAGS_TF; This is minor, I won't argue, but this can be moved into phase1(), afaics. Oleg.