Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 6 Jan 2003 13:42:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 6 Jan 2003 13:42:00 -0500 Received: from neon-gw-l3.transmeta.com ([63.209.4.196]:1296 "EHLO neon-gw.transmeta.com") by vger.kernel.org with ESMTP id ; Mon, 6 Jan 2003 13:41:59 -0500 Date: Mon, 6 Jan 2003 10:49:30 -0800 (PST) From: Linus Torvalds To: Luca Barbieri cc: Linux-Kernel ML Subject: Re: [PATCH] Set TIF_IRET in more places In-Reply-To: <20030106181737.GA6867@ldb> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1084 Lines: 27 On Mon, 6 Jan 2003, Luca Barbieri wrote: > > 1. vfork seems to not set any TIF_ flags so a ptracer setting regs > while a vforking task is stopped in ptrace_notify called from vfork > would result in clobbered %ecx and %edx. vfork and clone do not work at all with sysenter due to user stack issues. We should document that (it's already de-facto documented in glibc, but it should be explicitly documented somewhere). Btw, the vfork/clone problems aren't sysenter-specific per se: they are really a generic problem with any non-inlined system call mechanism. In particular, vfork() really cannot afford to have a stack frame. > 2. A ptracer could use %ecx or %edx to pass information to signal > handlers and this would not work with the current [rt_]sigsuspend. Yes. Although I don't see why it should matter, really. Linus - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/