From patchwork Thu Jun 6 16:16:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suzuki K Poulose X-Patchwork-Id: 10980019 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3823714C0 for ; Thu, 6 Jun 2019 16:17:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 27F9328A4C for ; Thu, 6 Jun 2019 16:17:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1C67328A63; Thu, 6 Jun 2019 16:17:18 +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=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id AEC2028A61 for ; Thu, 6 Jun 2019 16:17:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=jKSPyPOWS7UsTRWfbY8/5CAKBnPkXPK+VlJjO3zOUqM=; b=RNK2XxPRv52Sczx7g6bz6aCU6I Godk5ZJsuCWixrnsIfCXym4XI1Djx0CcaLGaf2sgC8+AfvwYMG+/IdBJ7rtjv4PNdMpwaPpwPlK6B 2cnR/DvnBQSPcyUh8IU4ZPVzFSv24puSJdksGEv1ayVu97yZiag3yParCZFhGUYuYsfynBLaU67Ew dtWv+hFAjpalxu4IBwySqc+E75vNcZhpKcJK0x3nlknXCx/FwrJ7QR2pEMSGGKcIa09yBU8IO3X52 aoVrhvZ1uvQSVALFcApjGp/p0+ok8d0WP4ZPKtWcaUwgiQAiNfscDBdBe2zckOfAcwCy5gYrJZwQU fZSRu+qg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hYv4h-0007aL-Es; Thu, 06 Jun 2019 16:17:11 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hYv4Y-0007Re-P9 for linux-arm-kernel@lists.infradead.org; Thu, 06 Jun 2019 16:17:04 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3AA6E15AB; Thu, 6 Jun 2019 09:17:02 -0700 (PDT) Received: from en101.cambridge.arm.com (en101.cambridge.arm.com [10.1.196.93]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 4E85B3F690; Thu, 6 Jun 2019 09:17:01 -0700 (PDT) From: Suzuki K Poulose To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v4 2/4] coresight: tmc-etr: alloc_perf_buf: Do not call smp_processor_id from preemptible Date: Thu, 6 Jun 2019 17:16:45 +0100 Message-Id: <1559837807-15447-3-git-send-email-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1559837807-15447-1-git-send-email-suzuki.poulose@arm.com> References: <1559837807-15447-1-git-send-email-suzuki.poulose@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190606_091702_817319_3D682A33 X-CRM114-Status: GOOD ( 13.88 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, mathieu.poirier@linaro.org, Suzuki K Poulose MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP During a perf session we try to allocate buffers on the "node" associated with the CPU the event is bound to. If it is not bound to a CPU, we use the current CPU node, using smp_processor_id(). However this is unsafe in a pre-emptible context and could generate the splats as below : BUG: using smp_processor_id() in preemptible [00000000] code: perf/1743 caller is tmc_alloc_etr_buffer+0x1bc/0x1f0 CPU: 1 PID: 1743 Comm: perf Not tainted 5.1.0-rc6-147786-g116841e #344 Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Feb 1 2019 Call trace: dump_backtrace+0x0/0x150 show_stack+0x14/0x20 dump_stack+0x9c/0xc4 debug_smp_processor_id+0x10c/0x110 tmc_alloc_etr_buffer+0x1bc/0x1f0 etm_setup_aux+0x1c4/0x230 rb_alloc_aux+0x1b8/0x2b8 perf_mmap+0x35c/0x478 mmap_region+0x34c/0x4f0 do_mmap+0x2d8/0x418 vm_mmap_pgoff+0xd0/0xf8 ksys_mmap_pgoff+0x88/0xf8 __arm64_sys_mmap+0x28/0x38 el0_svc_handler+0xd8/0x138 el0_svc+0x8/0xc Use NUMA_NO_NODE hint instead of using the current node for events not bound to CPUs. Fixes: 22f429f19c4135d51e9 ("coresight: etm-perf: Add support for ETR backend") Cc: Mathieu Poirier Signed-off-by: Suzuki K Poulose --- drivers/hwtracing/coresight/coresight-tmc-etr.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 7c81f63..5d2bf6d 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1184,14 +1184,11 @@ static struct etr_buf * alloc_etr_buf(struct tmc_drvdata *drvdata, struct perf_event *event, int nr_pages, void **pages, bool snapshot) { - int node, cpu = event->cpu; + int node; struct etr_buf *etr_buf; unsigned long size; - if (cpu == -1) - cpu = smp_processor_id(); - node = cpu_to_node(cpu); - + node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu); /* * Try to match the perf ring buffer size if it is larger * than the size requested via sysfs.