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 4B619C43387 for ; Wed, 19 Dec 2018 06:57:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1854E21841 for ; Wed, 19 Dec 2018 06:57:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728085AbeLSG5t (ORCPT ); Wed, 19 Dec 2018 01:57:49 -0500 Received: from pegase1.c-s.fr ([93.17.236.30]:44939 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726898AbeLSG5s (ORCPT ); Wed, 19 Dec 2018 01:57:48 -0500 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 43KQgr3jmdz9v0bM; Wed, 19 Dec 2018 07:57:44 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id yZAvX9HLZ8KX; Wed, 19 Dec 2018 07:57:44 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 43KQgr2y48z9v0bL; Wed, 19 Dec 2018 07:57:44 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 406BC8B85D; Wed, 19 Dec 2018 07:57:45 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id BkxrEO5HQSXt; Wed, 19 Dec 2018 07:57:45 +0100 (CET) Received: from PO15451 (po15451.idsi0.si.c-s.fr [172.25.231.2]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 0FAC78B754; Wed, 19 Dec 2018 07:57:45 +0100 (CET) Subject: Re: [PATCH v3] powerpc: implement CONFIG_DEBUG_VIRTUAL To: Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org References: <87y38nrkto.fsf@concordia.ellerman.id.au> <87a7l2s6p3.fsf@concordia.ellerman.id.au> From: Christophe Leroy Message-ID: Date: Wed, 19 Dec 2018 07:57:44 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.3.3 MIME-Version: 1.0 In-Reply-To: <87a7l2s6p3.fsf@concordia.ellerman.id.au> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 19/12/2018 à 01:26, Michael Ellerman a écrit : > 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. The hunk is obviously wrong for sure. Anyway there's a problem, most likely high_memory is not a valid virtual address, so without this hunk I get the following warning at every ioremap(): [ 0.000000] WARNING: CPU: 0 PID: 0 at ./arch/powerpc/include/asm/io.h:809 __ioremap_caller+0x9c/0x180 [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.20.0-rc6-s3k-dev-00677-g9c98dcab6203-dirty #615 [ 0.000000] NIP: c000fcd0 LR: c000fc64 CTR: 00000000 [ 0.000000] REGS: c073de50 TRAP: 0700 Not tainted (4.20.0-rc6-s3k-dev-00677-g9c98dcab6203-dirty) [ 0.000000] MSR: 00021032 CR: 28944422 XER: 0000f940 [ 0.000000] [ 0.000000] GPR00: c000fe04 c073df00 c06e1450 00000001 00004023 c073df38 c0018f50 00000001 [ 0.000000] GPR08: 00002000 08000000 00002000 00000000 88944224 00600000 00000000 07ff9580 [ 0.000000] GPR16: 00000000 07ffb94c 00000000 00000000 00000000 00000000 00000000 00000000 [ 0.000000] GPR24: 00000000 c0760000 0000019f ff000000 ff000000 c000fe04 00004000 c0018f50 [ 0.000000] NIP [c000fcd0] __ioremap_caller+0x9c/0x180 [ 0.000000] LR [c000fc64] __ioremap_caller+0x30/0x180 [ 0.000000] Call Trace: [ 0.000000] [c073df00] [c02fc23c] of_address_to_resource+0x114/0x154 (unreliable) [ 0.000000] [c073df30] [c000fe04] ioremap_wt+0x20/0x30 [ 0.000000] [c073df40] [c0018f50] mpc8xx_pic_init+0x70/0xf8 [ 0.000000] [c073df80] [c0655b84] mpc8xx_pics_init+0x10/0x6c [ 0.000000] [c073df90] [c0675080] cmpc885_pics_init+0x14/0x118 [ 0.000000] [c073dfa0] [c0652eb0] init_IRQ+0x24/0x38 [ 0.000000] [c073dfb0] [c0650b10] start_kernel+0x2a8/0x3d4 [ 0.000000] [c073dff0] [c0002258] start_here+0x44/0x98 [ 0.000000] Instruction dump: [ 0.000000] 419e00b8 7f83e378 480013fd 7c7d1b79 41820030 576304be 7c63ea14 80010034 [ 0.000000] bb410018 7c0803a6 38210030 4e800020 <0fe00000> 7f9c4840 409cffc4 480000a8 [ 0.000000] random: get_random_bytes called from print_oops_end_marker+0x60/0x84 with crng_init=0 [ 0.000000] ---[ end trace 25d7f28ce013ad37 ]--- I'll try and come with solution during the day. Christophe > > cheers >