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=-12.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 255E6C433DF for ; Thu, 16 Jul 2020 12:00:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EBD152076D for ; Thu, 16 Jul 2020 12:00:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594900852; bh=uIHeI2dm8rdCk7DKqpCQgSfBWLfxmE4uSZCDw/S6d0w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PLU9pyq88+Llr1u2BN+4ucgs9HWfbFHduhQ/fa5g+Xi8ObOj4J6EiFoTeB6vai+gA 7DoZtkqfKMtgPASizbaZnbOJNt30MAjW+mIzbaDrKlGytnfDL13562qeKlLnW+ZAW7 bQV+SlhQrxjkgiRlZbI6FzerKytZe1BnWL3GsqZo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728337AbgGPMAu (ORCPT ); Thu, 16 Jul 2020 08:00:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:33756 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726239AbgGPMAu (ORCPT ); Thu, 16 Jul 2020 08:00:50 -0400 Received: from localhost.localdomain (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A727420739; Thu, 16 Jul 2020 12:00:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594900849; bh=uIHeI2dm8rdCk7DKqpCQgSfBWLfxmE4uSZCDw/S6d0w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nCuNji9/aIGbX+LF+n3Qmr4xn8rCXK9vlKY3FTKleC1ksIXRuopyOCgr7pw98qXpJ hOxaf/g6+RDa3c4JKDwotVgIhPglXTbirYMAuNAczMeW5fE1OJKHs0dQHUi3kIXHFB FdYmSx4kGZqd78s8S2qRQ9VsfdPPl3RQMzdaf3oY= From: Will Deacon To: Qi Liu , john.garry@huawei.com, mark.rutland@arm.com, zhangshaokun@hisilicon.com Cc: catalin.marinas@arm.com, kernel-team@android.com, Will Deacon , wang.wanghaifeng@huawei.com, linux-kernel@vger.kernel.org, linuxarm@huawei.com, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] drivers/perf: Fix kernel panic when rmmod PMU modules during perf sampling Date: Thu, 16 Jul 2020 13:00:42 +0100 Message-Id: <159489574240.3940963.13068843481731049357.b4-ty@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <1594891165-8228-1-git-send-email-liuqi115@huawei.com> References: <1594891165-8228-1-git-send-email-liuqi115@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 16 Jul 2020 17:19:25 +0800, Qi Liu wrote: > When users try to remove PMU modules during perf sampling, kernel panic > will happen because the pmu->read() is a NULL pointer here. > > INFO on HiSilicon hip08 platform as follow: > pc : hisi_uncore_pmu_event_update+0x30/0xa4 [hisi_uncore_pmu] > lr : hisi_uncore_pmu_read+0x20/0x2c [hisi_uncore_pmu] > sp : ffff800010103e90 > x29: ffff800010103e90 x28: ffff0027db0c0e40 > x27: ffffa29a76f129d8 x26: ffffa29a77ceb000 > x25: ffffa29a773a5000 x24: ffffa29a77392000 > x23: ffffddffe5943f08 x22: ffff002784285960 > x21: ffff002784285800 x20: ffff0027d2e76c80 > x19: ffff0027842859e0 x18: ffff80003498bcc8 > x17: ffffa29a76afe910 x16: ffffa29a7583f530 > x15: 16151a1512061a1e x14: 0000000000000000 > x13: ffffa29a76f1e238 x12: 0000000000000001 > x11: 0000000000000400 x10: 00000000000009f0 > x9 : ffff8000107b3e70 x8 : ffff0027db0c1890 > x7 : ffffa29a773a7000 x6 : 00000007f5131013 > x5 : 00000007f5131013 x4 : 09f257d417c00000 > x3 : 00000002187bd7ce x2 : ffffa29a38f0f0d8 > x1 : ffffa29a38eae268 x0 : ffff0027d2e76c80 > Call trace: > hisi_uncore_pmu_event_update+0x30/0xa4 [hisi_uncore_pmu] > hisi_uncore_pmu_read+0x20/0x2c [hisi_uncore_pmu] > __perf_event_read+0x1a0/0x1f8 > flush_smp_call_function_queue+0xa0/0x160 > generic_smp_call_function_single_interrupt+0x18/0x20 > handle_IPI+0x31c/0x4dc > gic_handle_irq+0x2c8/0x310 > el1_irq+0xcc/0x180 > arch_cpu_idle+0x4c/0x20c > default_idle_call+0x20/0x30 > do_idle+0x1b4/0x270 > cpu_startup_entry+0x28/0x30 > secondary_start_kernel+0x1a4/0x1fc > > [...] Applied to arm64 (for-next/fixes), thanks! [1/1] drivers/perf: Fix kernel panic when rmmod PMU modules during perf sampling https://git.kernel.org/arm64/c/bdc5c744c7b6 Cheers, -- Will https://fixes.arm64.dev https://next.arm64.dev https://will.arm64.dev