From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C6302224B1E; Mon, 15 Jun 2026 01:14:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781486051; cv=none; b=jsh+hV0U/+MLpokIqdB97rgsh9V6U2eDTH3KUIbKOw5SJ7mn9ZVwSmUwOKsN7yB/fLPVLDpbeJQPmWN+j0CZox4XGyy3e/K/9LDNA9kGW/pqV+j+JRfWwO1jsiS/zx08mdl4EbFv+SappA7apZ9cBquBa3OTFIWsCFjSGWqWK24= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781486051; c=relaxed/simple; bh=MzBTi/tHniuupSgZNNgJV6HTE/0IMN1vtSnLhJYNgEQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=qZuTwAni8XoMGsAlgvXqfdbUzS53E0Ifjjm/JxQii2MGHXo8juWlvMjV1Us3duGOKbUrX2//BRfW2YF2CxJgkS9tTmo9ymdO9L6iBFT8SySndma7qV0PZy2AIXZAaBkm0P+MVGMEQN/ZQV50F2LDy/4S4Fpl4+5GSVXVAzy9wZE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VkCalxZg; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VkCalxZg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4BE8B1F000E9; Mon, 15 Jun 2026 01:14:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781486050; bh=cTmALM5v9MF+mL5ZFkPM1vyGeEUBS3mg7wggTL6NLQI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=VkCalxZg924mIno0xwbs4wmNqDNn27in62cDl1aT6V2ygcz7v/nJTMWniFewu5Bsy vXC24zmWqYyUhkMEphDD1BI6yTviVXz5WDUfdJB00YHKkC4zrX5Jo53A+f9384NI9E 3iK4No99eY7VzukJ3cXN+RRVMZ65Z7UeWOc3ypPb4Cyr9u4MHbt4nkpTAZdgHSrrn0 Dv+PE4w19ve94ATrO4EozpLfauaPADGWrU0xxwvWo4t+HptpQi/dUZTYpxPQgn7vqB nLJjoVIODc4/tzxV7tEhFMEDxrTPLjvN+2zWa6VOPUzAOcCidRe7cYQpmuXPMorE92 GFGpXubcMx4VQ== From: "Masami Hiramatsu (Google)" To: Steven Rostedt , Mathieu Desnoyers Cc: Jonathan Corbet , Shuah Khan , Masami Hiramatsu , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH v4 1/7] tracing/events: Fix to check the simple_tsk_fn creation Date: Mon, 15 Jun 2026 10:14:06 +0900 Message-ID: <178148604609.185520.8155504015524406945.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <178148603548.185520.3389196102475741865.stgit@devnote2> References: <178148603548.185520.3389196102475741865.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit From: Masami Hiramatsu (Google) Sashiko pointed that this sample code does not correctly handle the failure of thread creation because kthread_run() can return -errno. Check the simple_tsk_fn is correctly initialized (created) or not. Link: https://sashiko.dev/#/patchset/178092865666.163648.10457567771536160909.stgit%40devnote2 Fixes: 9cfe06f8cd5c ("tracing/events: add trace-events-sample") Signed-off-by: Masami Hiramatsu (Google) --- Changes in v4: - Fix to remove decrementing counter in error path, since foo_bar_reg() always returns 0. - Add a newline to error message. Changes in v3: - Recover the usage counter. --- samples/trace_events/trace-events-sample.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/samples/trace_events/trace-events-sample.c b/samples/trace_events/trace-events-sample.c index ecc7db237f2e..0b7a6efdb247 100644 --- a/samples/trace_events/trace-events-sample.c +++ b/samples/trace_events/trace-events-sample.c @@ -107,6 +107,10 @@ int foo_bar_reg(void) * for consistency sake, we still take the thread_mutex. */ simple_tsk_fn = kthread_run(simple_thread_fn, NULL, "event-sample-fn"); + if (IS_ERR_OR_NULL(simple_tsk_fn)) { + pr_err("Failed to create simple_thread_fn\n"); + simple_tsk_fn = NULL; + } out: mutex_unlock(&thread_mutex); return 0;