From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by oss.sgi.com id ; Mon, 8 Jan 2001 08:15:08 -0800 Received: from brutus.conectiva.com.br ([200.250.58.146]:30706 "EHLO dhcp046.distro.conectiva") by oss.sgi.com with ESMTP id ; Mon, 8 Jan 2001 08:14:57 -0800 Received: (ralf@lappi.waldorf-gmbh.de) by bacchus.dhis.org id ; Mon, 8 Jan 2001 14:05:06 -0200 Date: Mon, 8 Jan 2001 14:05:06 -0200 From: Ralf Baechle To: "Maciej W. Rozycki" Cc: "Kevin D. Kissell" , linux-mips@oss.sgi.com, Carsten Langgaard , Michael Shmulevich Subject: Re: User applications Message-ID: <20010108140506.B886@bacchus.dhis.org> References: <00d801c0797d$5cc410c0$0deca8c0@Ulysses> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from macro@ds2.pg.gda.pl on Mon, Jan 08, 2001 at 04:07:31PM +0100 X-Accept-Language: de,en,fr Sender: owner-linux-mips@oss.sgi.com Precedence: bulk Return-Path: X-Orcpt: rfc822;linux-mips-outgoing 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. Ralf