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 7CF9FC4321E for ; Thu, 1 Dec 2022 13:34:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231563AbiLANeR (ORCPT ); Thu, 1 Dec 2022 08:34:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46808 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231544AbiLANeJ (ORCPT ); Thu, 1 Dec 2022 08:34:09 -0500 Received: from elvis.franken.de (elvis.franken.de [193.175.24.41]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 901F5AC1B0; Thu, 1 Dec 2022 05:34:08 -0800 (PST) Received: from uucp (helo=alpha) by elvis.franken.de with local-bsmtp (Exim 3.36 #1) id 1p0jhW-000077-02; Thu, 01 Dec 2022 14:34:06 +0100 Received: by alpha.franken.de (Postfix, from userid 1000) id D4996C1FB9; Thu, 1 Dec 2022 14:33:44 +0100 (CET) Date: Thu, 1 Dec 2022 14:33:44 +0100 From: Thomas Bogendoerfer To: John Thomson Cc: Sergio Paracuellos , John Crispin , =?utf-8?B?QXLEsW7DpyDDnE5BTA==?= , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] mips: ralink: mt7621: do not use kzalloc too early Message-ID: <20221201133344.GC10560@alpha.franken.de> References: <20221114015658.2873120-1-git@johnthomson.fastmail.com.au> <20221114015658.2873120-4-git@johnthomson.fastmail.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221114015658.2873120-4-git@johnthomson.fastmail.com.au> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 14, 2022 at 11:56:58AM +1000, John Thomson wrote: > With CONFIG_SLUB=y, following commit 6edf2576a6cc ("mm/slub: enable > debugging memory wasting of kmalloc") mt7621 failed to boot very early, > without showing any console messages. > This exposed the pre-existing bug of mt7621.c using kzalloc before normal > memory management was available. > Prior to this slub change, there existed the unintended protection against > "kmem_cache *s" being NULL as slab_pre_alloc_hook() happened to > return NULL and bailed out of slab_alloc_node(). > This allowed mt7621 prom_soc_init to fail in the soc_dev_init kzalloc, > but continue booting without the SOC_BUS driver device registered. > > Console output from a DEBUG_ZBOOT vmlinuz kernel loading, > with mm/slub modified to warn on kmem_cache zero or null: > > zimage at: 80B842A0 810B4BC0 > Uncompressing Linux at load address 80001000 > Copy device tree to address 80B80EE0 > Now, booting the kernel... > > [ 0.000000] Linux version 6.1.0-rc3+ (john@john) > (mipsel-buildroot-linux-gnu-gcc.br_real (Buildroot > 2021.11-4428-g6b6741b) 12.2.0, GNU ld (GNU Binutils) 2.39) #73 SMP Wed > Nov 2 05:10:01 AEST 2022 > [ 0.000000] ------------[ cut here ]------------ > [ 0.000000] WARNING: CPU: 0 PID: 0 at mm/slub.c:3416 > kmem_cache_alloc+0x5a4/0x5e8 > [ 0.000000] Modules linked in: > [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.1.0-rc3+ #73 > [ 0.000000] Stack : 810fff78 80084d98 00000000 00000004 00000000 > 00000000 80889d04 80c90000 > [ 0.000000] 80920000 807bd328 8089d368 80923bd3 00000000 > 00000001 80889cb0 00000000 > [ 0.000000] 00000000 00000000 807bd328 8084bcb1 00000002 > 00000002 00000001 6d6f4320 > [ 0.000000] 00000000 80c97d3d 80c97d68 fffffffc 807bd328 > 00000000 00000000 00000000 > [ 0.000000] 00000000 a0000000 80910000 8110a0b4 00000000 > 00000020 80010000 80010000 > [ 0.000000] ... > [ 0.000000] Call Trace: > [ 0.000000] [<80008260>] show_stack+0x28/0xf0 > [ 0.000000] [<8070c958>] dump_stack_lvl+0x60/0x80 > [ 0.000000] [<8002e184>] __warn+0xc4/0xf8 > [ 0.000000] [<8002e210>] warn_slowpath_fmt+0x58/0xa4 > [ 0.000000] [<801c0fac>] kmem_cache_alloc+0x5a4/0x5e8 > [ 0.000000] [<8092856c>] prom_soc_init+0x1fc/0x2b4 > [ 0.000000] [<80928060>] prom_init+0x44/0xf0 > [ 0.000000] [<80929214>] setup_arch+0x4c/0x6a8 > [ 0.000000] [<809257e0>] start_kernel+0x88/0x7c0 > [ 0.000000] > [ 0.000000] ---[ end trace 0000000000000000 ]--- > [ 0.000000] SoC Type: MediaTek MT7621 ver:1 eco:3 > [ 0.000000] printk: bootconsole [early0] enabled > > Allowing soc_device_register to work exposed oops in the mt7621 phy pci, > and pci controller drivers from soc_device_match_attr, due to missing > sentinels in the quirks tables. These were fixed with: > commit 819b885cd886 ("phy: ralink: mt7621-pci: add sentinel to quirks > table") > not yet applied ("PCI: mt7621: add sentinel to quirks table") > > Link: https://lore.kernel.org/linux-mm/becf2ac3-2a90-4f3a-96d9-a70f67c66e4a@app.fastmail.com/ > Fixes: 71b9b5e0130d ("MIPS: ralink: mt7621: introduce 'soc_device' initialization") > Signed-off-by: John Thomson > --- > arch/mips/ralink/mt7621.c | 14 +++++++++----- > 1 file changed, 9 insertions(+), 5 deletions(-) applied to mips-next. Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]