From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bos-spam.mrv.com (mx5.mrv.com [140.179.254.12]) by ozlabs.org (Postfix) with ESMTP id 49841B7C0E for ; Wed, 30 Sep 2009 07:03:36 +1000 (EST) Date: Tue, 29 Sep 2009 14:03:31 -0700 From: Rex Feany To: Joakim Tjernlund Subject: Re: [PATCH] powerpc/8xx: fix regression introduced by cache coherency rewrite Message-ID: <20090929210331.GA25779@laura.chatsunix.int.mrv.com> References: <20090924233346.GA445@compile2.chatsunix.int.mrv.com> <1253836376.7103.469.camel@pasglop> <20090925013528.GA2584@compile2.chatsunix.int.mrv.com> <1253843480.7103.492.camel@pasglop> <20090929012106.GA22798@compile2.chatsunix.int.mrv.com> <1254208057.5771.7.camel@pasglop> <1254212198.5256.0.camel@pasglop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Cc: "linuxppc-dev@ozlabs.org" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Thus spake Joakim Tjernlund (joakim.tjernlund@transmode.se): > Benjamin Herrenschmidt wrote on 29/09/2009 10:16:38: > > > > > > > hmm, yes. You do get this and mysterious SEGV if you hit the but so does > > > other bugs too so this is probably due to missing invalidation. > > > > > > I suspect that something like below will fix the problem and > > > is the "correct" fix(untested, not even compiled): > > > > Ok but do we also still have to worry about the "unpopulated" TLB > > entries and invalidate them somehow when populating ? > > Since I am probably the only one that knows about DAR problem I figured > I should take a stab at it. This is not tested, but I hope Rex and the list > can do that. Once this works as it should, we can remove all special handling > for 8xx in copy_tofrom_user() and friends. > No sign-off yet, want some confirmation first. It doesn't make a difference. I applied it to the top of the tree, it got to userspace but it is stuck. Using break I am able to dump the registers, I'm not sure if this is useful. Oh, well, I finally got to a shell but it is unusably slow. Is there some test code that would be better to run? I tried looking through the mailing list archives but I couldn't find anything. thanks! /rex. SysRq : Show Regs NIP: c00588d0 LR: c000e3c4 CTR: 00001fde REGS: c3459d90 TRAP: 0501 Not tainted (2.6.32-rc2-00013-g2d222d9-dirty) MSR: 00009032 CR: 44008422 XER: 20006a02 TASK = c3438050[13] 'rc.sysinit' THREAD: c3458000 GPR00: c000e3c4 c3459e40 c3438050 c21a2a60 c345bdf4 0fd81032 00000000 3001e920 GPR08: 00000000 00000005 c21a2a60 c0210000 03438260 NIP [c00588d0] handle_mm_fault+0x10/0xacc LR [c000e3c4] do_page_fault+0x2f0/0x474 Call Trace: [c3459e40] [c0059328] handle_mm_fault+0xa68/0xacc (unreliable) [c3459e90] [c000e418] do_page_fault+0x344/0x474 [c3459f40] [c000d520] handle_page_fault+0xc/0x80 Instruction dump: 4bff15f1 39600000 80010014 7d635b78 7c0803a6 bbc10008 38210010 4e800020 7c0802a6 9421ffb0 3d60c021 be810020 <90010054> 38000000 90020000 396b4bec SysRq : Show Regs NIP: c000e0e0 LR: c000d520 CTR: 00001fde REGS: c21adde0 TRAP: 0501 Not tainted (2.6.32-rc2-00013-g2d222d9-dirty) MSR: 00009032 CR: 48008424 XER: 00006a02 TASK = c3438460[18] 'sh' THREAD: c21ac000 GPR00: c000d520 c21ade90 c3438460 c21adf50 0fd76cb8 c0000000 00000004 0fee8c44 GPR08: 00009f6c c000d788 00009032 c000d514 03438670 NIP [c000e0e0] do_page_fault+0xc/0x474 LR [c000d520] handle_page_fault+0xc/0x80 Call Trace: [c21ade90] [c000e418] do_page_fault+0x344/0x474 (unreliable) [c21adf40] [c000d520] handle_page_fault+0xc/0x80 Instruction dump: 3863f604 7fe4fb78 7fc5f378 4bffcd39 80010014 bbc10008 7c0803a6 38210010 4e800020 7c0802a6 9421ff50 bf010090 <900100b4> 7c7e1b78 800300a0 7c9d2378 SysRq : Show Regs NIP: c005930c LR: c000e3c4 CTR: 00001fde REGS: c21add90 TRAP: 0501 Not tainted (2.6.32-rc2-00013-g2d222d9-dirty) MSR: 00009032 CR: 24002422 XER: 00006a02 TASK = c3438460[18] 'sh' THREAD: c21ac000 GPR00: c0236000 c21ade40 c3438460 c21a2a60 c3444df4 c3456000 00000000 feff0000 GPR08: c21ac000 03456000 c0220000 00000001 03438670 NIP [c005930c] handle_mm_fault+0xa4c/0xacc LR [c000e3c4] do_page_fault+0x2f0/0x474 Call Trace: [c21ade40] [c0059328] handle_mm_fault+0xa68/0xacc (unreliable) [c21ade90] [c000e3c4] do_page_fault+0x2f0/0x474 [c21adf40] [c000d520] handle_page_fault+0xc/0x80 Instruction dump: 4802192d 48000094 2f9f0000 3ba00001 419e0088 7fe3fb78 4bff46a1 48000078 7fe3fb78 4bff4695 48000070 63390020 <633f0080> 7f45d378 7f63db78 7f04c378