From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by oss.sgi.com id ; Mon, 8 Jan 2001 05:53:46 -0800 Received: from mx.mips.com ([206.31.31.226]:4296 "EHLO mx.mips.com") by oss.sgi.com with ESMTP id ; Mon, 8 Jan 2001 05:53:25 -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 FAA17844; Mon, 8 Jan 2001 05:52:49 -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 FAA23644; Mon, 8 Jan 2001 05:52:46 -0800 (PST) Received: from mips.com (copsun17 [192.168.205.27]) by copfs01.mips.com (8.9.1/8.9.0) with ESMTP id OAA23151; Mon, 8 Jan 2001 14:52:11 +0100 (MET) Message-ID: <3A59C60A.71FA35E0@mips.com> Date: Mon, 08 Jan 2001 14:52:10 +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: Michael Shmulevich CC: "linux-mips@oss.sgi.com" Subject: Re: User applications References: <3A598AFC.83204F56@mips.com> <3A59C0FB.62E52EF0@jungo.com> 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 Michael Shmulevich wrote: > Carsten Langgaard wrote: > > > I have a few questions about user applications. > > > > When a new user process is started will its user space be cleared by the > > kernel or is there a potential leak from an older user process ? > > Usually it is defied by the loader. If the data section contents is set to > LOAD, then the contents of the section will be loaded from disk (no leak), > if not -- whatever values left i nmemory will be there, or exactly, the > virtual page of some other proccess that was swapped out or ended. > > > What about the registers values, are they cleared for each new user > > application or will it simply contain the current value it got when the > > user application is started ? > > It depends on the context switch algorithm of the processor, I think. > > > How can you flush the data and instruction cashes from a user > > application ? > > > > As far as I understand, ASID must take care of it. It contains unique IDs > per process virtual space, so that even > though virtual addresses may be found in TLB, their ASID will be different, > causing TLB miss and probably page fault. > My problem is that I want to make self-modified code, so I need to flush both the instruction and data 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 > > Michael. -- _ _ ____ ___ 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