From patchwork Thu Jun 6 16:16:44 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: 165991 Delivered-To: patch@linaro.org Received: by 2002:a92:9e1a:0:0:0:0:0 with SMTP id q26csp8996709ili; Thu, 6 Jun 2019 09:17:15 -0700 (PDT) X-Google-Smtp-Source: APXvYqx2nyImq2UJiSVYqG5mpV1Ql4e0MExPE7VivsQEf2vWYPkd+Xbm8BXwaE5dgZWMXc5LGgvH X-Received: by 2002:a17:90a:b296:: with SMTP id c22mr717713pjr.28.1559837835273; Thu, 06 Jun 2019 09:17:15 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1559837835; cv=none; d=google.com; s=arc-20160816; b=cuowA8G1cCqQ6nAQS9rBbc/Ud3AseJXwhwb6mDb7sPMRVgrpRT/FgLshfuj//6gn5L rDb+tQKtc5powGvN5wC5UWdZwnb9DE59xwBve1uS0Ew4TVXIxGIrPR0yi1AcOnTEDvWJ SJWrRrNIf3lRWN3D774zGMYjXpvkY3Dj3cDHx90l6+ftEvqJMEaNWLlGZp8aPbIBEa3f 2bXlgVX9wiVzB45xWpUVxy90e557fBYU4DHxqJNs/4a7jxcKge1vAhNVbldKT9U+1fUM wULjZi2r0jhPRz2Kpdrw0nQ8PANBKfBp5q3sp4M9GRLMoNVHhfGqoidzlQ1+1mbTpFlI iCog== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from; bh=AofZw8eyFqh1fUA3njHauacrQ1/YnXNI+k45xQsHZrg=; b=PyfT9kYY49G0/nxz5lhA8I9nRjmJSgQ/AfxxPFZMbAB0EU296ubX/xtwOIQYgivXg9 6OyzWzduZnoWBzcx2ufFRa/RSxLfGCdBKONA3gl9eOuU5DeHofyQ/VZBDLiC+xAL6UBD n1MikuBxr8/DMUSv+oc3qi6dcfL2rtew7CmnmpH5G9mYUyU1k4KxBXVGnrwzz9TbWAgL jOaRWemwzJHBRUcXkvYe2dBgZF2q/jX0vdtpvFwC9sRgKmJ9fbhX3PM+d2oT0M4/4+ji udtCXM0nuSkEu7Mi4mHMMENzNUBt0QkyE+wIwuhCBKoxdFwHQ21rqrjkYSVx6/2bWLv5 DJQQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id x10si2382097pfj.93.2019.06.06.09.17.15; Thu, 06 Jun 2019 09:17:15 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729684AbfFFQRD (ORCPT + 30 others); Thu, 6 Jun 2019 12:17:03 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:49816 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729230AbfFFQRB (ORCPT ); Thu, 6 Jun 2019 12:17:01 -0400 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 120D515A2; Thu, 6 Jun 2019 09:17:01 -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 25B613F690; Thu, 6 Jun 2019 09:17:00 -0700 (PDT) From: Suzuki K Poulose To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, mathieu.poirier@linaro.org, Suzuki K Poulose Subject: [PATCH v4 1/4] coresight: tmc-etr: Do not call smp_processor_id() from preemptible Date: Thu, 6 Jun 2019 17:16:44 +0100 Message-Id: <1559837807-15447-2-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> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org During a perf session we try to allocate buffers on the "node" associated with the CPU the event is bound to. If it's 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 alloc_etr_buf.isra.6+0x80/0xa0 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 alloc_etr_buf.isra.6+0x80/0xa0 tmc_alloc_etr_buffer+0x12c/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: 855ab61c16bf70b646 ("coresight: tmc-etr: Refactor function tmc_etr_setup_perf_buf()") Cc: Mathieu Poirier Signed-off-by: Suzuki K Poulose --- drivers/hwtracing/coresight/coresight-tmc-etr.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) -- 2.7.4 diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index ce0114a..7c81f63 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1323,13 +1323,11 @@ static struct etr_perf_buffer * tmc_etr_setup_perf_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; struct etr_perf_buffer *etr_perf; - if (cpu == -1) - cpu = smp_processor_id(); - node = cpu_to_node(cpu); + node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu); etr_perf = kzalloc_node(sizeof(*etr_perf), GFP_KERNEL, node); if (!etr_perf)