From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 615F01F667B; Thu, 24 Oct 2024 14:28:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729780087; cv=none; b=dks4q5MZccypZefRGcAlfFBAGtpYg6E+tl2h/vDWUoJ9GNnXKUwfUJ12VuMn/9fK8/8AZutFitd+GKWSLYg1XJ8UhVAOjYHQJaPnr80o2XAUqPrn7SExgymO4/5EZxAGuniXkJPxbkADS6vIrzWV4+5abKDZ1xPz0HYSl2NlA+Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729780087; c=relaxed/simple; bh=t476ydiJw4Yxe6GO8SwSasYToXGgWXap70lQnOiSPYY=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=G5phr8fXYOWOx5+9rjCs+4myJRdQhKOovicPQMqsRRR70xi+6WfhSldcY0alNmXYWTvx52qgTmmq7/G0Dq9sBoMFpIgI8UTJ1/NdPJY6+HVshbUJGCQGmfILMVWe0MbkgZAOHyth6+bTUHLW22cppAAL6zy8Fcm4E0nxqGL5j94= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rsrHhhpI; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="rsrHhhpI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB11DC4CECC; Thu, 24 Oct 2024 14:28:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729780086; bh=t476ydiJw4Yxe6GO8SwSasYToXGgWXap70lQnOiSPYY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=rsrHhhpIiPkkOjI/h2w0LELI2aDTqIDAsFWc1yNkMlU+q+qeajpojUmzuBNlgEe5x Lxl0bi5/roh0cVZgGBK7uzGMYWW8FBRORaN6qnuyd5QqStb82d8X07RKySPOksd6WO efzS+y4Q5rHaVXzLFLwFGKJCF7Lw1HVeVo2d40t4FSeADBPQNS3RmRZwWSFYlaLqGL HxxBuJpvTpVfenBHR7HTTtRcWTvw3wKnA/86auKyeLw0o0vMcAMGW/Rh02Ujz7u6UZ 0nBfzYTRcShZq9RxHsNte9+Nol2wKPUhbKgBtaDlPHOHVgEB/i3Iv4md0H3R0A9K1m s94pE0DN8XHoA== Date: Thu, 24 Oct 2024 23:28:02 +0900 From: Masami Hiramatsu (Google) To: Li Huafei Cc: , , , , , , Subject: Re: [PATCH v2] fgraph: Fix missing unlock in register_ftrace_graph() Message-Id: <20241024232802.57bb710cc1fee46608c4aed4@kernel.org> In-Reply-To: <20241024155917.1019580-1-lihuafei1@huawei.com> References: <20241024155917.1019580-1-lihuafei1@huawei.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 24 Oct 2024 23:59:17 +0800 Li Huafei wrote: > Use guard(mutex)() to acquire and automatically release ftrace_lock, > fixing the issue of not unlocking when calling cpuhp_setup_state() > fails. > > Fixes smatch warning: > > kernel/trace/fgraph.c:1317 register_ftrace_graph() warn: inconsistent returns '&ftrace_lock'. > Looks good to me. Acked-by: Masami Hiramatsu (Google) Thank you, > Fixes: 2c02f7375e65 ("fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks") > Reported-by: kernel test robot > Reported-by: Dan Carpenter > Closes: https://lore.kernel.org/r/202410220121.wxg0olfd-lkp@intel.com/ > Suggested-by: Steven Rostedt > Signed-off-by: Li Huafei > --- > Changes in v2: > - Use guard() to acquire and automatically release ftrace_lock. > --- > kernel/trace/fgraph.c | 10 +++------- > 1 file changed, 3 insertions(+), 7 deletions(-) > > diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c > index 41e7a15dcb50..cd1c2946018c 100644 > --- a/kernel/trace/fgraph.c > +++ b/kernel/trace/fgraph.c > @@ -1252,7 +1252,7 @@ int register_ftrace_graph(struct fgraph_ops *gops) > int ret = 0; > int i = -1; > > - mutex_lock(&ftrace_lock); > + guard(mutex)(&ftrace_lock); > > if (!fgraph_initialized) { > ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "fgraph_idle_init", > @@ -1273,10 +1273,8 @@ int register_ftrace_graph(struct fgraph_ops *gops) > } > > i = fgraph_lru_alloc_index(); > - if (i < 0 || WARN_ON_ONCE(fgraph_array[i] != &fgraph_stub)) { > - ret = -ENOSPC; > - goto out; > - } > + if (i < 0 || WARN_ON_ONCE(fgraph_array[i] != &fgraph_stub)) > + return -ENOSPC; > gops->idx = i; > > ftrace_graph_active++; > @@ -1313,8 +1311,6 @@ int register_ftrace_graph(struct fgraph_ops *gops) > gops->saved_func = NULL; > fgraph_lru_release_index(i); > } > -out: > - mutex_unlock(&ftrace_lock); > return ret; > } > > -- > 2.25.1 > > -- Masami Hiramatsu (Google)