From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 29 Oct 2007 07:08:24 -0500 From: Josh Boyer To: benh@kernel.crashing.org Subject: Re: [PATCH/RFC] powerpc: Pass PID argument to _tlbie (WAS: Apparent kernel bug with GDB on ppc405) Message-ID: <20071029070824.72854629@weaponx.rchland.ibm.com> In-Reply-To: <1193470322.18243.63.camel@pasglop> References: <20071024194640.GB19691@waste.org> <1193363202.7018.36.camel@pasglop> <1193369005.7018.46.camel@pasglop> <20071026144134.GW19691@waste.org> <1193448653.18243.9.camel@pasglop> <1193470322.18243.63.camel@pasglop> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: linuxppc-dev list , linuxppc-embedded@ozlabs.org, Kumar Gala , Matt Mackall List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Sat, 27 Oct 2007 17:32:02 +1000 Benjamin Herrenschmidt wrote: > Allright, so Matt, let me know if that fixes your problem with gdb, and > I'll clean the patch up a bit and submit it. I want to double check if > something similar may be needed for freescale booke. > > Basically, the problem is that things like get_user_pages() can cause > COW operations which in turn call _tlbie() to be called for translations > that aren't in the current address space. > > The current 40x and 44x implementation of _tlbie doesn't handle that > properly as it only invalidates entries in the current PID. > > This is an attempt at fixing it. Untested, I just checked it builds for > arch/powerpc and arch/ppc. I also haven't looked whether the freescale > BookE _tlbie needs similar treatement (it will get passed the pid in r4 > with that patch, so if it needs to do something with it, it can). Kumar, > can you have a look ? This looks pretty good at first glance. I'll try to test it out today, but I'd still like to hear if it solves Matt's problem as I doubt I'll be able to duplicate it. josh