From patchwork Wed Apr 12 20:07:39 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 9678345 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id DBE5E601C3 for ; Wed, 12 Apr 2017 20:22:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D06E028562 for ; Wed, 12 Apr 2017 20:22:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C4CDC285D3; Wed, 12 Apr 2017 20:22:16 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7BE5E28562 for ; Wed, 12 Apr 2017 20:22:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755542AbdDLUUn (ORCPT ); Wed, 12 Apr 2017 16:20:43 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:35477 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755380AbdDLUUl (ORCPT ); Wed, 12 Apr 2017 16:20:41 -0400 Received: from localhost ([127.0.0.1] helo=[127.0.1.1]) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1cyOjU-0002kF-Nb; Wed, 12 Apr 2017 22:19:17 +0200 Message-Id: <20170412201043.231299672@linutronix.de> User-Agent: quilt/0.63-1 Date: Wed, 12 Apr 2017 22:07:39 +0200 From: Thomas Gleixner To: LKML Cc: Peter Zijlstra , Ingo Molnar , Sebastian Siewior , Benjamin Herrenschmidt , "David S. Miller" , Fenghua Yu , Herbert Xu , Lai Jiangshan , Len Brown , Michael Ellerman , "Rafael J. Wysocki" , Tejun Heo , Tony Luck , Viresh Kumar , linux-crypto@vger.kernel.org Subject: [patch 13/13] crypto: n2 - Replace racy task affinity logic References: <20170412200726.941336635@linutronix.de> MIME-Version: 1.0 Content-Disposition: inline; filename=crypto--n2---Use-work_on_cpu---instead-of-affinity-games.patch Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP spu_queue_register() needs to invoke setup functions on a particular CPU. This is achieved by temporarily setting the affinity of the calling user space thread to the requested CPU and reset it to the original affinity afterwards. That's racy vs. CPU hotplug and concurrent affinity settings for that thread resulting in code executing on the wrong CPU and overwriting the new affinity setting. Replace it by using work_on_cpu_safe() which guarantees to run the code on the requested CPU or to fail in case the CPU is offline. Signed-off-by: Thomas Gleixner Cc: Herbert Xu Cc: "David S. Miller" Cc: linux-crypto@vger.kernel.org Acked-by: Herbert Xu --- drivers/crypto/n2_core.c | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) --- a/drivers/crypto/n2_core.c +++ b/drivers/crypto/n2_core.c @@ -65,6 +65,11 @@ struct spu_queue { struct list_head list; }; +struct spu_qreg { + struct spu_queue *queue; + unsigned long type; +}; + static struct spu_queue **cpu_to_cwq; static struct spu_queue **cpu_to_mau; @@ -1631,31 +1636,27 @@ static void queue_cache_destroy(void) kmem_cache_destroy(queue_cache[HV_NCS_QTYPE_CWQ - 1]); } -static int spu_queue_register(struct spu_queue *p, unsigned long q_type) +static long spu_queue_register_workfn(void *arg) { - cpumask_var_t old_allowed; + struct spu_qreg *qr = arg; + struct spu_queue *p = qr->queue; + unsigned long q_type = qr->type; unsigned long hv_ret; - if (cpumask_empty(&p->sharing)) - return -EINVAL; - - if (!alloc_cpumask_var(&old_allowed, GFP_KERNEL)) - return -ENOMEM; - - cpumask_copy(old_allowed, ¤t->cpus_allowed); - - set_cpus_allowed_ptr(current, &p->sharing); - hv_ret = sun4v_ncs_qconf(q_type, __pa(p->q), CWQ_NUM_ENTRIES, &p->qhandle); if (!hv_ret) sun4v_ncs_sethead_marker(p->qhandle, 0); - set_cpus_allowed_ptr(current, old_allowed); + return hv_ret ? -EINVAL : 0; +} - free_cpumask_var(old_allowed); +static int spu_queue_register(struct spu_queue *p, unsigned long q_type) +{ + int cpu = cpumask_any_and(&p->sharing, cpu_online_mask); + struct spu_qreg qr = { .queue = p, .type = q_type }; - return (hv_ret ? -EINVAL : 0); + return work_on_cpu_safe(cpu, &qr); } static int spu_queue_setup(struct spu_queue *p)