From patchwork Wed Aug 14 10:41:31 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 171264 Delivered-To: patch@linaro.org Received: by 2002:a92:d204:0:0:0:0:0 with SMTP id y4csp645793ily; Wed, 14 Aug 2019 03:42:08 -0700 (PDT) X-Google-Smtp-Source: APXvYqydPO/XEzUCy5J0sHupjdWy1IDINbWImJj5592j/mG3m196qfoA4lEhKAnLHpsQGsNaAAdp X-Received: by 2002:a17:90a:b016:: with SMTP id x22mr6750112pjq.116.1565779328848; Wed, 14 Aug 2019 03:42:08 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1565779328; cv=none; d=google.com; s=arc-20160816; b=saHEXILg5st+cvbPcNkuDaAGA6yt01iBvl21KtIeo8RDoR7WzBuDHfUM/IeB6/dyRh 41kOJbL16+8tkLe5rinsdPNnZQNzpebgTMDP4gS0ztO811kVDic5B7H1izl28dwz6FYC p3qjuA/gpGXHsIMJ/ch8AJKxizM+8En9o0bxDCf+aWaXKPRsc6e6mRSeiszBqks9cJlt loJ/0GDxRAYROv1T5QQPhkEuzlUcdy4DE4XIoBJmzIn3L6CNJ3hT7/X9lFkIvaQQ10Gj FMsVUqbthAqhS5FPLBCJ4+cnrq/R4kcE4e4hQwjFW2svTDAZeotATDQwWHmutm8QImb/ X4jQ== 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=WtptYsngeFBPUz6M4DkJn+HFZHVWXjAsFaA3NcOCgic=; b=h6s9nO739iJCT4ruFsM5WfCq8fN25ytN0OtoT/B7JyjdtKDU1oNVcUKxmiMI3HgTcQ YooWwGRDCehdP+W1/g4ADg7O5QLCGneOHIVCV2BoezSovkbSeCETu7xEUnhD/vKaOW5+ 8V9yqjRrNbP3Pmu8HLHn11+HMvy4hX/0avRXjVYt7JtAskk3/NpJE/XFpcKUSwiYWhQi 7w0cS0rKA1mJyC82e5sCV6lkyPzKXQlSeBQX1HisFzt0HgFeX8hTg0FOGhity38Nf7jn bYMky1H+ysX3ZEhMrHL2hXstYjPTfLf71EBkijtd0GGR2yGNZatF5dFfwDQrvIRp6Y2P AmLA== 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 z14si62165051plo.104.2019.08.14.03.42.08; Wed, 14 Aug 2019 03:42:08 -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 S1727662AbfHNKmH (ORCPT + 28 others); Wed, 14 Aug 2019 06:42:07 -0400 Received: from foss.arm.com ([217.140.110.172]:52030 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726821AbfHNKmB (ORCPT ); Wed, 14 Aug 2019 06:42:01 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4741815AD; Wed, 14 Aug 2019 03:42:01 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 6EE2A3F706; Wed, 14 Aug 2019 03:41:59 -0700 (PDT) From: Mark Rutland To: linux-kernel@vger.kernel.org Cc: ak@linux.intel.com, akpm@linux-foundation.org, bigeasy@linutronix.de, bp@suse.de, catalin.marinas@arm.com, davem@davemloft.net, hch@lst.de, kan.liang@intel.com, mark.rutland@arm.com, mingo@kernel.org, peterz@infradead.org, riel@surriel.com, will@kernel.org Subject: [PATCH 9/9] samples/kretprobe: correctly check for kthreads Date: Wed, 14 Aug 2019 11:41:31 +0100 Message-Id: <20190814104131.20190-10-mark.rutland@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190814104131.20190-1-mark.rutland@arm.com> References: <20190814104131.20190-1-mark.rutland@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In general, a non-NULL current->mm doesn't imply that current is a kthread, as kthreads can install an mm via use_mm(), and so it's preferable to use is_kthread() to determine whether a thread is a kthread. For consistency, let's use is_kthread() here. Signed-off-by: Mark Rutland Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Andrew Morton --- samples/kprobes/kretprobe_example.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.11.0 diff --git a/samples/kprobes/kretprobe_example.c b/samples/kprobes/kretprobe_example.c index 186315ca88b3..d6e0bf196f0e 100644 --- a/samples/kprobes/kretprobe_example.c +++ b/samples/kprobes/kretprobe_example.c @@ -41,7 +41,7 @@ static int entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs) { struct my_data *data; - if (!current->mm) + if (is_kthread(current)) return 1; /* Skip kernel threads */ data = (struct my_data *)ri->data;