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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2AB9FC3DA78 for ; Fri, 13 Jan 2023 19:54:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230321AbjAMTyQ (ORCPT ); Fri, 13 Jan 2023 14:54:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37658 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230150AbjAMTyP (ORCPT ); Fri, 13 Jan 2023 14:54:15 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF781869F1; Fri, 13 Jan 2023 11:54:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=2jFGVJyJ/iosZVuHIVC8047QtfgIKPOOdSnUPFqHVR4=; b=io34DlsqpWudAAwKTIGL2I9Mte qGFUz/cB1rR9ifWOxojzItN5ZnRD4ANxVfw2TlU1628oI/TT43CdD2ml09NNpbVK/dloopLqJmkYf dS9t/g1xGSpKg3U383Wop3rWMd+iQpEtRfXEWV+SkUM123Hl4kDhAsN+NU6SfBVC4M0TiKKVJk6gv t2s8KYOEV3ljETtuI1edG8vmUmkVtQJmegphfIEwMqEtNti63eaLf+HRIRSQ/mXaLzztvOU9ymoX9 WWwHzjPvYUGVS3dpPmrKH8RXUincsc5FXWdsc7zkEUzRCZCTQ9VT1KH7r1IZqqZyM9ML6nW/cMBPL xEPGhLKQ==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1pGQ84-006Oq6-BL; Fri, 13 Jan 2023 19:54:20 +0000 Date: Fri, 13 Jan 2023 19:54:20 +0000 From: Matthew Wilcox To: Mark Brown Cc: Naresh Kamboju , open list , Linux-Next Mailing List , lkft-triage@lists.linaro.org, regressions@lists.linux.dev, Kefeng Wang , Andrew Morton , Arnd Bergmann , Anders Roxell Subject: Re: next: BUG: kernel NULL pointer dereference, address: 0000000000000008 - RIP: 0010:do_wp_page Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-next@vger.kernel.org On Fri, Jan 13, 2023 at 07:43:58PM +0000, Mark Brown wrote: > On Fri, Jan 13, 2023 at 03:53:44PM +0000, Matthew Wilcox wrote: > > > Uh, are you compiling your kernels without debuginfo? The results > > from syzbot & 0day are much more useful: > > FWIW here's a decode from arm64 (the boards I sampled all looked very > similar): We've identified the bad commit now ... this thread is just about improving the process for next time ;-) > <1>Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 > <1>Mem abort info: > <1> ESR = 0x0000000096000005 > <1> EC = 0x25: DABT (current EL), IL = 32 bits > <1> SET = 0, FnV = 0 > <1> EA = 0, S1PTW = 0 > <1> FSC = 0x05: level 1 translation fault > <1>Data abort info: > <1> ISV = 0, ISS = 0x00000005 > <1> CM = 0, WnR = 0 > <1>user pgtable: 4k pages, 39-bit VAs, pgdp=00000000422b3000 > <1>[0000000000000008] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 > <0>Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP > <4>Modules linked in: > <4>CPU: 3 PID: 58 Comm: modprobe Not tainted 6.2.0-rc3-next-20230113 #2 > <4>Hardware name: Libre Computer Board ALL-H3-CC H5 (DT) > <4>pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > <4>pc : do_wp_page (include/linux/page-flags.h:251 mm/memory.c:3047 mm/memory.c:3425) > <4>lr : do_wp_page (mm/memory.c:3046 mm/memory.c:3425) > <4>sp : ffffffc00972bc50 > <4>x29: ffffffc00972bc50 x28: ffffff80022e8000 x27: ffffff8002f9c060 > <4>x26: 0000000000000002 x25: ffffff80022b4990 x24: 0000000000000000 > <4>x23: ffffff8002f9c000 x22: 0000000000000000 x21: 0000000000000000 > <4>x20: 0000000000000a55 x19: ffffffc00972bd38 x18: 0000000000000000 > <4>x17: 0000000000000000 x16: 0000000000000000 x15: ffffff80022bfa00 > <4>x14: ffffff8002f9c000 x13: ffffffc008b3bc88 x12: 0000007f9b02bfff > <4>x11: 0000007f9ad49fc0 x10: ffffff80022bfa0c x9 : ffffff80022bfa00 > <4>x8 : ffffff80022bfa50 x7 : ffffff8002f9c000 x6 : 0000000000000000 > <4>x5 : 0000000000041362 x4 : 0000007f9ad49000 x3 : ffffff80022b4990 > <4>x2 : 0000000000100073 x1 : ffffff80022e8000 x0 : 0000000000000a55 > <4>Call trace: > <4> do_wp_page (include/linux/page-flags.h:251 mm/memory.c:3047 mm/memory.c:3425) > <4> __handle_mm_fault (mm/memory.c:4937 mm/memory.c:5061) > <4> handle_mm_fault (mm/memory.c:5207) > <4> do_page_fault (arch/arm64/mm/fault.c:512 arch/arm64/mm/fault.c:612) > <4> do_mem_abort (arch/arm64/mm/fault.c:831) > <4> el0_da (arch/arm64/include/asm/daifflags.h:28 arch/arm64/kernel/entry-common.c:133 arch/arm64/kernel/entry-common.c:142 arch/arm64/kernel/entry-common.c:516) > <4> el0t_64_sync_handler (arch/arm64/kernel/entry-common.c:659) > <4> el0t_64_sync (arch/arm64/kernel/entry.S:584) > <0>Code: aa1503f8 b9402a60 aa1503f6 b90063e0 (f94006a0) > All code > ======== > 0: aa1503f8 .word 0xaa1503f8 > 4: b9402a60 .word 0xb9402a60 > 8: aa1503f6 .word 0xaa1503f6 > c: b90063e0 .word 0xb90063e0 > 10:* f94006a0 .word 0xf94006a0 <-- trapping instruction > > Code starting with the faulting instruction > =========================================== > 0: f94006a0 .word 0xf94006a0 > <4>---[ end trace 0000000000000000 ]--- > > The disassembly is disappointing, I didn't peer at why that is.