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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 6C8AAC432C0 for ; Mon, 18 Nov 2019 11:17:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 439912071C for ; Mon, 18 Nov 2019 11:17:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ellerman.id.au header.i=@ellerman.id.au header.b="P9Zr8f/a" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726695AbfKRLRv (ORCPT ); Mon, 18 Nov 2019 06:17:51 -0500 Received: from ozlabs.org ([203.11.71.1]:58623 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726461AbfKRLRv (ORCPT ); Mon, 18 Nov 2019 06:17:51 -0500 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 47Gmdl70pTz9sPT; Mon, 18 Nov 2019 22:17:47 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ellerman.id.au; s=201909; t=1574075868; bh=tmFsG35fivh8ejaJ9XgtyHjYWy2bP+f58gTSBDMDha4=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=P9Zr8f/a4w0PzwG1oWqu08JCQY+iz+8l0rLmzbZtoHmq7ycuc176lzu3stnmUgSAk YRlqwPjyFpjtdqzvRaacmy/QSdCuR6IlJSlXjOZaxQ2qdX4GY6srNfzWJFU4HTQISA D4TwYFvUBh3Lk7d2tlbRriDjiUrN980RbI9nRz9B3+6J8OcWOJn3APJc/03UvHx0kV lotx5uRVLSe3kMtDsQKKWK/EMad1wvAOOHRo8wn89nR6JE0mJxN1qy5WRvVDs469Ka c6etghTsvYmSHvanhED1nBTxSrY+A4Nn8A2O6RT8C4C86qKgVO8gPqegBeZH0+TpVp CvmANc5dYW8og== From: Michael Ellerman To: Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH] powerpc/8xx: Fix permanently mapped IMMR region. In-Reply-To: References: Date: Mon, 18 Nov 2019 22:17:46 +1100 Message-ID: <87sgmlcu1x.fsf@mpe.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 Christophe Leroy writes: > When not using large TLBs, the IMMR region is still > mapped as a whole block in the FIXMAP area. > > Do not remove pages mapped in the FIXMAP region when > initialising paging. > > Properly report that the IMMR region is block-mapped even > when not using large TLBs. > > Signed-off-by: Christophe Leroy > --- > arch/powerpc/mm/mem.c | 8 -------- > arch/powerpc/mm/nohash/8xx.c | 13 +++++++------ > 2 files changed, 7 insertions(+), 14 deletions(-) This blows up pmac32_defconfig + qemu mac99 for me with: NET: Registered protocol family 1 RPC: Registered named UNIX socket transport module. RPC: Registered udp transport module. RPC: Registered tcp transport module. RPC: Registered tcp NFSv4.1 backchannel transport module. PCI: CLS 0 bytes, default 32 Trying to unpack rootfs image as initramfs... BUG: Unable to handle kernel data access on write at 0xfffdf000 Faulting instruction address: 0xc001eb4c Oops: Kernel access of bad area, sig: 11 [#1] BE PAGE_SIZE=4K MMU=Hash PowerMac Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 5.4.0-rc2-gcc49+ #50 NIP: c001eb4c LR: c0394214 CTR: 00000080 REGS: ef0b5a70 TRAP: 0300 Not tainted (5.4.0-rc2-gcc49+) MSR: 00009032 CR: 44088444 XER: 20000000 DAR: fffdf000 DSISR: 42000000 GPR00: 00000080 ef0b5b28 ef0b0000 fffdf000 ef2001e4 00000000 fffdeffc fffe0000 GPR08: ef2011e8 00000008 00000009 00000004 28088442 00000000 c0005734 00000000 GPR16: 00000000 00000000 00000000 00000000 c07f0000 c0735600 00000000 ef09f500 GPR24: fffdf000 00000000 00000000 00000000 fffdf000 ef0b5c38 00001000 00001000 NIP [c001eb4c] memcpy+0x88/0x10c LR [c0394214] iov_iter_copy_from_user_atomic+0x1fc/0x468 Call Trace: [ef0b5b28] [c0394060] iov_iter_copy_from_user_atomic+0x48/0x468 (unreliable) [ef0b5b68] [c0131438] generic_perform_write+0xfc/0x218 [ef0b5bb8] [c01360bc] __generic_file_write_iter+0x134/0x26c [ef0b5bf8] [c0136324] generic_file_write_iter+0x130/0x1d8 [ef0b5c28] [c01a1754] __vfs_write+0x170/0x220 [ef0b5ca8] [c01a34f0] vfs_write+0xcc/0x1e0 [ef0b5cd8] [c01a386c] ksys_write+0xd0/0x120 [ef0b5d08] [c08a03a4] xwrite+0x44/0xa4 [ef0b5d28] [c08a0b64] do_copy+0x94/0xdc [ef0b5d48] [c08a0044] write_buffer+0x40/0x68 [ef0b5d68] [c08a00cc] flush_buffer+0x60/0xe4 [ef0b5d98] [c08e87bc] __gunzip+0x2f0/0x3d0 [ef0b5dd8] [c08a0974] unpack_to_rootfs+0x1d8/0x334 [ef0b5e38] [c08a1238] populate_rootfs+0x80/0x168 [ef0b5e68] [c0005494] do_one_initcall+0x58/0x1f4 [ef0b5ed8] [c089e918] kernel_init_freeable+0x198/0x29c [ef0b5f18] [c000574c] kernel_init+0x18/0x110 [ef0b5f38] [c0016274] ret_from_kernel_thread+0x14/0x1c Instruction dump: 4200fff0 5400f0bf 7c0903a6 41820010 85240004 95260004 4200fff8 54a0d97f 54a506fe 39600004 7c0903a6 4182004c <7c0b37ec> 80e40004 81040008 8124000c ---[ end trace 52276ec2410ac084 ]--- cheers