From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3F41EC43387 for ; Wed, 19 Dec 2018 00:26:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 178D42184C for ; Wed, 19 Dec 2018 00:26:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727541AbeLSA0D (ORCPT ); Tue, 18 Dec 2018 19:26:03 -0500 Received: from ozlabs.org ([203.11.71.1]:55409 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726512AbeLSA0C (ORCPT ); Tue, 18 Dec 2018 19:26:02 -0500 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPSA id 43KFzr2MJkz9s3Z; Wed, 19 Dec 2018 11:26:00 +1100 (AEDT) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au From: Michael Ellerman To: Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH v3] powerpc: implement CONFIG_DEBUG_VIRTUAL In-Reply-To: <87y38nrkto.fsf@concordia.ellerman.id.au> References: <87y38nrkto.fsf@concordia.ellerman.id.au> Date: Wed, 19 Dec 2018 11:26:00 +1100 Message-ID: <87a7l2s6p3.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Michael Ellerman writes: > Christophe Leroy writes: > >> This patch implements CONFIG_DEBUG_VIRTUAL to warn about >> incorrect use of virt_to_phys() and page_to_phys() > > This commit is breaking my p5020ds booting a 32-bit kernel with: > > smp: Bringing up secondary CPUs ... > __ioremap(): phys addr 0x7fef5000 is RAM lr ioremap_coherent > Unable to handle kernel paging request for data at address 0x00000000 > Faulting instruction address: 0xc002e950 > Oops: Kernel access of bad area, sig: 11 [#1] > BE SMP NR_CPUS=24 CoreNet Generic > Modules linked in: > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.20.0-rc2-gcc-7.0.1-00138-g9a0380d299e9 #148 > NIP: c002e950 LR: c002eb20 CTR: 00000001 > REGS: e804bd20 TRAP: 0300 Not tainted (4.20.0-rc2-gcc-7.0.1-00138-g9a0380d299e9) > MSR: 00021002 CR: 28004222 XER: 00000000 > DEAR: 00000000 ESR: 00000000 > GPR00: c002eb20 e804bdd0 e8050000 00000000 00021002 00000000 00000050 00021002 > GPR08: 2d3f0000 00000001 00000000 00000004 24000842 00000000 c00026d0 00000000 > GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000001 > GPR24: 00029002 7fef5140 30000000 00000000 00000000 00000040 00000001 00000000 > NIP [c002e950] smp_85xx_kick_cpu+0x120/0x410 > LR [c002eb20] smp_85xx_kick_cpu+0x2f0/0x410 > Call Trace: > [e804bdd0] [c002eb20] smp_85xx_kick_cpu+0x2f0/0x410 (unreliable) > [e804be20] [c0012e38] __cpu_up+0xc8/0x230 > [e804be50] [c0040b34] bringup_cpu+0x34/0x110 > [e804be70] [c00418a8] cpu_up+0x128/0x250 > [e804beb0] [c0b84b14] smp_init+0xc4/0x10c > [e804bee0] [c0b75c1c] kernel_init_freeable+0xc8/0x250 > [e804bf20] [c00026e8] kernel_init+0x18/0x120 > [e804bf40] [c0011298] ret_from_kernel_thread+0x14/0x1c > Instruction dump: > 7fb3e850 57bdd1be 2e1d0000 41d20250 57bd3032 393dffc0 7e6a9b78 5529d1be > 39290001 7d2903a6 60000000 60000000 <7c0050ac> 394a0040 4200fff8 7c0004ac > ---[ end trace edcab2a1dfd5b38c ]--- > > > Which is obviously this hunk: > >> diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c >> index 4fc77a99c9bf..68d204a45cd0 100644 >> --- a/arch/powerpc/mm/pgtable_32.c >> +++ b/arch/powerpc/mm/pgtable_32.c >> @@ -143,7 +143,7 @@ __ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *call >> * Don't allow anybody to remap normal RAM that we're using. >> * mem_init() sets high_memory so only do the check after that. >> */ >> - if (slab_is_available() && (p < virt_to_phys(high_memory)) && >> + if (slab_is_available() && virt_addr_valid(p) && >> page_is_ram(__phys_to_pfn(p))) { >> printk("__ioremap(): phys addr 0x%llx is RAM lr %ps\n", >> (unsigned long long)p, __builtin_return_address(0)); > > > I'll try and come up with a fix tomorrow. Actually I think that change is just wrong. virt_addr_valid() takes a virtual address, but p is a physical address. So I'll drop this hunk for now, which makes the patch a no-op when DEBUG_VIRTUAL is n which is probably the way it should be. cheers