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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B423C433F5 for ; Tue, 16 Nov 2021 20:34:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B56461260 for ; Tue, 16 Nov 2021 20:34:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230356AbhKPUhD (ORCPT ); Tue, 16 Nov 2021 15:37:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:49768 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229649AbhKPUhC (ORCPT ); Tue, 16 Nov 2021 15:37:02 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7519461037; Tue, 16 Nov 2021 20:34:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1637094845; bh=l/dWLarqEiULV16loJz9pqYO1tl43IJkf7N+4+RSMzE=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=YLPy/WNNfSlbTj+TTVBESv/gmHmoJKN32uvTyYzN4V5tbpANersFwEMW/292UASzp wUqGPtBlKzik90k28oMg+JtiThX1F0EOxq0TZ/+mpAzpwW4ZQlUAR8n5e853LnSyu0 cbwwvrf2jmaG8mDO/hcBe+26HrVmTD5nLH686HpU5VXl4JTr/yneopjFqXCmI3WAH3 lFAn3RjCvqsm6QMbxA6CUTz7bhxBCI/tOPBSHmvANsEAd6vJDOmN4StThB64eqaEIK 7ccshRwY3i9dOdGuUGHspO5aB2mZ41xJ6K2bRpJOH4/bQL7hzNno89XvIWgrFy4TW8 vJC54KSjm1oTQ== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 428345C0433; Tue, 16 Nov 2021 12:34:05 -0800 (PST) Date: Tue, 16 Nov 2021 12:34:05 -0800 From: "Paul E. McKenney" To: Juri Lelli Cc: Jun Miao , urezki@gmail.com, elver@google.com, josh@joshtriplett.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, joel@joelfernandes.org, qiang.zhang1211@gmail.com, rcu@vger.kernel.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, jianwei.hu@windriver.com Subject: Re: [V2][PATCH] rcu: avoid alloc_pages() when recording stack Message-ID: <20211116203405.GU641268@paulmck-ThinkPad-P17-Gen-1> Reply-To: paulmck@kernel.org References: <1637018582-10788-1-git-send-email-jun.miao@intel.com> <20211116173959.osdzlvv7niyxthd6@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211116173959.osdzlvv7niyxthd6@localhost.localdomain> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 16, 2021 at 05:39:59PM +0000, Juri Lelli wrote: > Hi, > > On 16/11/21 07:23, Jun Miao wrote: > > The default kasan_record_aux_stack() calls stack_depot_save() with GFP_NOWAIT, > > which in turn can then call alloc_pages(GFP_NOWAIT, ...). In general, however, > > it is not even possible to use either GFP_ATOMIC nor GFP_NOWAIT in certain > > non-preemptive contexts/RT kernel including raw_spin_locks (see gfp.h and ab00db216c9c7). > > Fix it by instructing stackdepot to not expand stack storage via alloc_pages() > > in case it runs out by using kasan_record_aux_stack_noalloc(). > > > > Jianwei Hu reported: > > BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:969 > > in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 15319, name: python3 > > INFO: lockdep is turned off. > > irq event stamp: 0 > > hardirqs last enabled at (0): [<0000000000000000>] 0x0 > > hardirqs last disabled at (0): [] copy_process+0xaf3/0x2590 > > softirqs last enabled at (0): [] copy_process+0xaf3/0x2590 > > softirqs last disabled at (0): [<0000000000000000>] 0x0 > > CPU: 6 PID: 15319 Comm: python3 Tainted: G W O 5.15-rc7-preempt-rt #1 > > Hardware name: Supermicro SYS-E300-9A-8C/A2SDi-8C-HLN4F, BIOS 1.1b 12/17/2018 > > Call Trace: > > show_stack+0x52/0x58 > > dump_stack+0xa1/0xd6 > > ___might_sleep.cold+0x11c/0x12d > > rt_spin_lock+0x3f/0xc0 > > rmqueue+0x100/0x1460 > > rmqueue+0x100/0x1460 > > mark_usage+0x1a0/0x1a0 > > ftrace_graph_ret_addr+0x2a/0xb0 > > rmqueue_pcplist.constprop.0+0x6a0/0x6a0 > > __kasan_check_read+0x11/0x20 > > __zone_watermark_ok+0x114/0x270 > > get_page_from_freelist+0x148/0x630 > > is_module_text_address+0x32/0xa0 > > __alloc_pages_nodemask+0x2f6/0x790 > > __alloc_pages_slowpath.constprop.0+0x12d0/0x12d0 > > create_prof_cpu_mask+0x30/0x30 > > alloc_pages_current+0xb1/0x150 > > stack_depot_save+0x39f/0x490 > > kasan_save_stack+0x42/0x50 > > kasan_save_stack+0x23/0x50 > > kasan_record_aux_stack+0xa9/0xc0 > > __call_rcu+0xff/0x9c0 > > call_rcu+0xe/0x10 > > put_object+0x53/0x70 > > __delete_object+0x7b/0x90 > > kmemleak_free+0x46/0x70 > > slab_free_freelist_hook+0xb4/0x160 > > kfree+0xe5/0x420 > > kfree_const+0x17/0x30 > > kobject_cleanup+0xaa/0x230 > > kobject_put+0x76/0x90 > > netdev_queue_update_kobjects+0x17d/0x1f0 > > ... ... > > ksys_write+0xd9/0x180 > > __x64_sys_write+0x42/0x50 > > do_syscall_64+0x38/0x50 > > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > > Links: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/include/linux/kasan.h?id=7cb3007ce2da27ec02a1a3211941e7fe6875b642 > > Fixes: 84109ab58590 ("rcu: Record kvfree_call_rcu() call stack for KASAN") > > Fixes: 26e760c9a7c8 ("rcu: kasan: record and print call_rcu() call stack") > > Reported-by: Jianwei Hu > > Reviewed-by: Uladzislau Rezki (Sony) > > Signed-off-by: Jun Miao > > --- > > I gave this a quick try on RT. No splats. Nice! > > Tested-by: Juri Lelli Applied with Juri's Tested-by and Marco's Acked-by. Thank you all! Thanx, Paul