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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 27AF5C76186 for ; Wed, 17 Jul 2019 07:20:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 00E522077C for ; Wed, 17 Jul 2019 07:20:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725912AbfGQHUl (ORCPT ); Wed, 17 Jul 2019 03:20:41 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:42859 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725799AbfGQHUl (ORCPT ); Wed, 17 Jul 2019 03:20:41 -0400 Received: by mail-wr1-f65.google.com with SMTP id x1so8545165wrr.9 for ; Wed, 17 Jul 2019 00:20:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=q7vSPFdz5CEYOwSreUnRICAWUDFGoG4IPZiYDw1Erec=; b=NxqJmRvncLJhN9/4DzjkQYMeO8oslodV950rZpvT+1v/sdL9jFoteZWWagqR4Xxg4Q ZurFnXcmsac3F5Y2XePLQldjCXAWrg4bEgzLNOffwPp97KEd8cMdATM+wPWBNyMFqEJb N0vDZgRwRYox0f7XXtyo3D37rD57Ad9IvWeqbg3q7t1eijWaCM9olWsrZ4C6o71/n5j+ or7N1mY7ugMdFz1r1VGvBtQhQStB3bk/ZSyLveAfuCPSfOekwul41IR6wZ0V+AujUOTD BIUFZ8470QGp6Au9pCUgQgOVLkul7LEjiksCIl37kgkkt/f5YV4bXzn5/b6klQBN8kb+ 3Mbw== X-Gm-Message-State: APjAAAWah0/Uisri0fH4eTzJUYIckTfZGAMXo6CS8MBjS0R0XNjk1RhB BUvMVV3NROXQzhGsxpHjsNbdYw== X-Google-Smtp-Source: APXvYqxZ/oRc6LQuDTtdo3kTgTyUlud+FKAPr527BLTa+duWXgkOfSA/Eap/fmt1dPjCEDwWBe0OHA== X-Received: by 2002:a5d:680d:: with SMTP id w13mr41545907wru.141.1563348038987; Wed, 17 Jul 2019 00:20:38 -0700 (PDT) Received: from localhost.localdomain.com ([151.15.230.231]) by smtp.gmail.com with ESMTPSA id n12sm23490884wmc.24.2019.07.17.00.20.37 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 17 Jul 2019 00:20:38 -0700 (PDT) From: Juri Lelli To: rostedt@goodmis.org, tglx@linutronix.de, bigeasy@linutronix.de Cc: linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org, williams@redhat.com, Juri Lelli Subject: [PATCH] net/xfrm/xfrm_ipcomp: Use {get,put}_cpu_light Date: Wed, 17 Jul 2019 09:20:19 +0200 Message-Id: <20190717072019.13681-1-juri.lelli@redhat.com> X-Mailer: git-send-email 2.17.2 Sender: linux-rt-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org The following BUG has been reported while running ipsec tests. BUG: scheduling while atomic: irq/78-eno3-rx-/12023/0x00000002 Modules linked in: ipcomp xfrm_ipcomp ... Preemption disabled at: [] ipcomp_input+0xd0/0x9a0 [xfrm_ipcomp] CPU: 1 PID: 12023 Comm: irq/78-eno3-rx- Kdump: loaded Not tainted [...] #1 Hardware name: [...] Call Trace: dump_stack+0x5c/0x80 ? ipcomp_input+0xd0/0x9a0 [xfrm_ipcomp] __schedule_bug.cold.81+0x44/0x51 __schedule+0x5bf/0x6a0 schedule+0x39/0xd0 rt_spin_lock_slowlock_locked+0x10e/0x2b0 rt_spin_lock_slowlock+0x50/0x80 get_page_from_freelist+0x609/0x1560 ? zlib_updatewindow+0x5a/0xd0 __alloc_pages_nodemask+0xd9/0x280 ipcomp_input+0x299/0x9a0 [xfrm_ipcomp] xfrm_input+0x5e3/0x960 xfrm4_ipcomp_rcv+0x34/0x50 ip_local_deliver_finish+0x22d/0x250 ip_local_deliver+0x6d/0x110 ? ip_rcv_finish+0xac/0x480 ip_rcv+0x28e/0x3f9 ? packet_rcv+0x43/0x4c0 __netif_receive_skb_core+0xb7c/0xd10 ? inet_gro_receive+0x8e/0x2f0 netif_receive_skb_internal+0x4a/0x160 napi_gro_receive+0xee/0x110 tg3_rx+0x2a8/0x810 [tg3] tg3_poll_work+0x3b3/0x830 [tg3] tg3_poll_msix+0x3b/0x170 [tg3] net_rx_action+0x1ff/0x470 ? __switch_to_asm+0x41/0x70 do_current_softirqs+0x223/0x3e0 ? irq_thread_check_affinity+0x20/0x20 __local_bh_enable+0x51/0x60 irq_forced_thread_fn+0x5e/0x80 ? irq_finalize_oneshot.part.45+0xf0/0xf0 irq_thread+0x13d/0x1a0 ? wake_threads_waitq+0x30/0x30 kthread+0x112/0x130 ? kthread_create_worker_on_cpu+0x70/0x70 ret_from_fork+0x35/0x40 The problem resides in the fact that get_cpu() called from ipcomp_input() disables preemption, and that triggers the scheduling while atomic BUG further down the callpath chain of get_page_from_freelist(), i.e., ipcomp_input ipcomp_decompress <-- get_cpu() alloc_page(GFP_ATOMIC) alloc_pages(GFP_ATOMIC, 0) alloc_pages_current __alloc_pages_nodemask get_page_from_freelist (try_this_zone:) rmqueue rmqueue_pcplist __rmqueue_pcplist rmqueue_bulk <-- spin_lock(&zone->lock) - BUG Fix this by using {get,put}_cpu_light() in ipcomp_decompress(). Signed-off-by: Juri Lelli --- Hi, This has been found on a 4.19.x-rt kernel, but 5.x-rt(s) are affected as well. Best, Juri --- net/xfrm/xfrm_ipcomp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/xfrm/xfrm_ipcomp.c b/net/xfrm/xfrm_ipcomp.c index a00ec715aa46..39d9e663384f 100644 --- a/net/xfrm/xfrm_ipcomp.c +++ b/net/xfrm/xfrm_ipcomp.c @@ -45,7 +45,7 @@ static int ipcomp_decompress(struct xfrm_state *x, struct sk_buff *skb) const int plen = skb->len; int dlen = IPCOMP_SCRATCH_SIZE; const u8 *start = skb->data; - const int cpu = get_cpu(); + const int cpu = get_cpu_light(); u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu); struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu); int err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen); @@ -103,7 +103,7 @@ static int ipcomp_decompress(struct xfrm_state *x, struct sk_buff *skb) err = 0; out: - put_cpu(); + put_cpu_light(); return err; } -- 2.17.2