From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by oss.sgi.com id ; Mon, 8 Jan 2001 08:24:18 -0800 Received: from mx.mips.com ([206.31.31.226]:57545 "EHLO mx.mips.com") by oss.sgi.com with ESMTP id ; Mon, 8 Jan 2001 08:24:03 -0800 Received: from newman.mips.com (ns-dmz [206.31.31.225]) by mx.mips.com (8.9.3/8.9.0) with ESMTP id IAA18989; Mon, 8 Jan 2001 08:23:59 -0800 (PST) Received: from copfs01.mips.com (copfs01 [192.168.205.101]) by newman.mips.com (8.9.3/8.9.0) with ESMTP id IAA26782; Mon, 8 Jan 2001 08:23:56 -0800 (PST) Received: from mips.com (copsun17 [192.168.205.27]) by copfs01.mips.com (8.9.1/8.9.0) with ESMTP id RAA29505; Mon, 8 Jan 2001 17:23:21 +0100 (MET) Message-ID: <3A59E978.873182CB@mips.com> Date: Mon, 08 Jan 2001 17:23:20 +0100 From: Carsten Langgaard X-Mailer: Mozilla 4.75 [en] (X11; U; SunOS 5.7 sun4u) X-Accept-Language: en MIME-Version: 1.0 To: Ralf Baechle CC: "Maciej W. Rozycki" , "Kevin D. Kissell" , linux-mips@oss.sgi.com, Michael Shmulevich Subject: Re: User applications References: <00d801c0797d$5cc410c0$0deca8c0@Ulysses> <20010108140506.B886@bacchus.dhis.org> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mips@oss.sgi.com Precedence: bulk Return-Path: X-Orcpt: rfc822;linux-mips-outgoing Ralf Baechle wrote: > On Mon, Jan 08, 2001 at 04:07:31PM +0100, Maciej W. Rozycki wrote: > > > The only case caches need to be synchronized is modifying some code. The > > ptrace syscall does it automatically for text writes -- it's needed and > > used by gdb to set breakpoints, for example. For other code there is > > cacheflush() which allows you to flush a cache range relevant to a given > > virtual address (I see it's not implemented very well at the moment). > > > > Obviously, you don't want to allow unprivileged users to flush caches as > > a whole as it could lead to a DoS. > > You obviously want to allow partial cache flushes or trampolines don't work > and flushing the entire cache can be constructed from that. > What we need is a mechanism to partial invalidate the I-cache and a mechanism to write-back and/or invalidate the D-cache. /Carsten -- _ _ ____ ___ Carsten Langgaard Mailto:carstenl@mips.com |\ /|||___)(___ MIPS Denmark Direct: +45 4486 5527 | \/ ||| ____) Lautrupvang 4B Switch: +45 4486 5555 TECHNOLOGIES 2750 Ballerup Fax...: +45 4486 5556 Denmark http://www.mips.com