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=-9.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 099E6C4363D for ; Fri, 25 Sep 2020 06:59:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B785A2311B for ; Fri, 25 Sep 2020 06:59:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="bVzxSUdf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727226AbgIYG7Y (ORCPT ); Fri, 25 Sep 2020 02:59:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727068AbgIYG7Y (ORCPT ); Fri, 25 Sep 2020 02:59:24 -0400 Received: from mail-ot1-x343.google.com (mail-ot1-x343.google.com [IPv6:2607:f8b0:4864:20::343]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 18027C0613CE for ; Thu, 24 Sep 2020 23:59:24 -0700 (PDT) Received: by mail-ot1-x343.google.com with SMTP id o8so1378078otl.4 for ; Thu, 24 Sep 2020 23:59:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=weXxFykQEoWkylmqQdC8XlhgTA7e+X/thM7MZfJW0BM=; b=bVzxSUdfVsSTQj5XZhRUlNrTGy8YGrNZBvB16Sxshx2oDQEFa8awXbnngrK+bxnKEB iuAIjmZBuvblnJHRXomaNyo7IjAwkFVfWI5mscB25APwf+G6Tqt8rT6vA8LuUl0H6ld2 Nh8ZENsi0WyC/C9EzvGNLX2q6a/v3br96dVRe67sCqiqe8P8ZNeU35p8ScHqQtJ9FGP3 mUWa6OTN8Z7nmqYruTyCQWZ8e9Sz9wBrE8nGSXLxvyoRTj90Trk/wR171Tld34ELtpED OgmMEb3THRcNPrQ1q+txwnPRieOWpvKrJGThSqz27b4bKZnEtFhCDhzsXAKXiU53Dc28 Xs3A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=weXxFykQEoWkylmqQdC8XlhgTA7e+X/thM7MZfJW0BM=; b=U4ag4O1Srnd4LFyHGx/yTMGqrjhdJHMbh/gEKtWVkore5905bM5XnyZpqGN7me+LZ4 IlI9Zm0T5GAOXf8VydGycYcuirfl62J8hduLV2wfkDbiZWSgOb+54wnomKQh8o/Y+2Rs IzfT3eisehZRdBMwFNgirb/xWn/c2Sk7CEOBtI57G6kgPcBQNqoR3IzFrxFrvf1TleIV HVyWwv7GF/OpSiz6p0hx6RAuTyhRU3evcLPfwnkl8qim5hYYcTvdvAJtbRgBjzHccgOV ZEzEVKDcvKFmTEl2DPNRDaER+eQ42IDwPTcwYjZVJGphRvhFpzFgLpnjb8D/eO5oObFd TP6g== X-Gm-Message-State: AOAM532g0OX8KofOLjAKgIMchAVZHbV83JYkruv+R2SAoPr7uVSvpGlL 9AAZDWP395L/gWJYHd+4p4Ot8YyOyY2b2CDeDVqGJQ== X-Google-Smtp-Source: ABdhPJywJK/A0kYevthGXra2XnR6b9pNCW6AzR5QPq+K79s9oG2Ggprdhgi0kkhhx9i0sjvzEZVXUbfyIT5OisUO9CM= X-Received: by 2002:a9d:2666:: with SMTP id a93mr1943186otb.324.1601017163384; Thu, 24 Sep 2020 23:59:23 -0700 (PDT) MIME-Version: 1.0 References: <20200918174543.13108-1-r.czerwinski@pengutronix.de> In-Reply-To: <20200918174543.13108-1-r.czerwinski@pengutronix.de> From: Jens Wiklander Date: Fri, 25 Sep 2020 08:59:12 +0200 Message-ID: Subject: Re: [PATCH] tee: optee: replace might_sleep with cond_resched To: Rouven Czerwinski Cc: kernel@pengutronix.de, op-tee@lists.trustedfirmware.org, Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 18, 2020 at 7:45 PM Rouven Czerwinski wrote: > > On Kernels with CONFIG_PREEMPT_NONE might_sleep() is not enough to force > rescheduling, replace it with a resched check and cond_resched. Fixes > the following stall: > > [ 572.945146] rcu: INFO: rcu_sched self-detected stall on CPU > [ 572.949275] rcu: 0-....: (2099 ticks this GP) idle=572/1/0x40000002 softirq=7412/7412 fqs=974 > [ 572.957964] (t=2100 jiffies g=10393 q=21) > [ 572.962054] NMI backtrace for cpu 0 > [ 572.965540] CPU: 0 PID: 165 Comm: xtest Not tainted 5.8.7 #1 > [ 572.971188] Hardware name: STM32 (Device Tree Support) > [ 572.976354] [] (unwind_backtrace) from [] (show_stack+0x10/0x14) > [ 572.984080] [] (show_stack) from [] (dump_stack+0xc4/0xd8) > [ 572.991300] [] (dump_stack) from [] (nmi_cpu_backtrace+0x90/0xc4) > [ 572.999130] [] (nmi_cpu_backtrace) from [] (nmi_trigger_cpumask_backtrace+0xec/0x130) > [ 573.008706] [] (nmi_trigger_cpumask_backtrace) from [] (rcu_dump_cpu_stacks+0xe8/0x110) > [ 573.018453] [] (rcu_dump_cpu_stacks) from [] (rcu_sched_clock_irq+0x7fc/0xa88) > [ 573.027416] [] (rcu_sched_clock_irq) from [] (update_process_times+0x30/0x8c) > [ 573.036291] [] (update_process_times) from [] (tick_sched_timer+0x4c/0xa8) > [ 573.044905] [] (tick_sched_timer) from [] (__hrtimer_run_queues+0x174/0x358) > [ 573.053696] [] (__hrtimer_run_queues) from [] (hrtimer_interrupt+0x118/0x2bc) > [ 573.062573] [] (hrtimer_interrupt) from [] (arch_timer_handler_virt+0x28/0x30) > [ 573.071536] [] (arch_timer_handler_virt) from [] (handle_percpu_devid_irq+0x8c/0x240) > [ 573.081109] [] (handle_percpu_devid_irq) from [] (generic_handle_irq+0x34/0x44) > [ 573.090156] [] (generic_handle_irq) from [] (__handle_domain_irq+0x5c/0xb0) > [ 573.098857] [] (__handle_domain_irq) from [] (gic_handle_irq+0x4c/0x90) > [ 573.107209] [] (gic_handle_irq) from [] (__irq_svc+0x6c/0x90) > [ 573.114682] Exception stack(0xd90dfcf8 to 0xd90dfd40) > [ 573.119732] fce0: ffff0004 00000000 > [ 573.127917] fd00: 00000000 00000000 00000000 00000000 00000000 00000000 d93493cc ffff0000 > [ 573.136098] fd20: d2bc39c0 be926998 d90dfd58 d90dfd48 c09f3384 c01151f0 400d0013 ffffffff > [ 573.144281] [] (__irq_svc) from [] (__arm_smccc_smc+0x10/0x20) > [ 573.151854] [] (__arm_smccc_smc) from [] (optee_smccc_smc+0x3c/0x44) > [ 573.159948] [] (optee_smccc_smc) from [] (optee_do_call_with_arg+0xb8/0x154) > [ 573.168735] [] (optee_do_call_with_arg) from [] (optee_invoke_func+0x110/0x190) > [ 573.177786] [] (optee_invoke_func) from [] (tee_ioctl+0x10b8/0x11c0) > [ 573.185879] [] (tee_ioctl) from [] (ksys_ioctl+0xe0/0xa4c) > [ 573.193101] [] (ksys_ioctl) from [] (ret_fast_syscall+0x0/0x54) > [ 573.200750] Exception stack(0xd90dffa8 to 0xd90dfff0) > [ 573.205803] ffa0: be926bf4 be926a78 00000003 8010a403 be926908 004e3cf8 > [ 573.213987] ffc0: be926bf4 be926a78 00000000 00000036 be926908 be926918 be9269b0 bffdf0f8 > [ 573.222162] ffe0: b6d76fb0 be9268fc b6d66621 b6c7e0d8 > > seen on STM32 DK2. > > Signed-off-by: Rouven Czerwinski > --- > drivers/tee/optee/call.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/tee/optee/call.c b/drivers/tee/optee/call.c > index 20b6fd7383c5..83b73b1d52f0 100644 > --- a/drivers/tee/optee/call.c > +++ b/drivers/tee/optee/call.c > @@ -8,6 +8,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -148,7 +149,8 @@ u32 optee_do_call_with_arg(struct tee_context *ctx, phys_addr_t parg) > */ > optee_cq_wait_for_completion(&optee->call_queue, &w); > } else if (OPTEE_SMC_RETURN_IS_RPC(res.a0)) { > - might_sleep(); > + if(need_resched()) > + cond_resched(); This looks OK to me. But I'd prefer if someone else could confirm this too. Thanks, Jens > param.a0 = res.a0; > param.a1 = res.a1; > param.a2 = res.a2; > -- > 2.28.0 >