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 88C6C36605D; Tue, 24 Feb 2026 08:33:27 +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=1771922007; cv=none; b=tQ9Khj+w0F2XMQD+t9Ro0hcyaWqQJWZb3hz7HcH8LGFrU2lgD/tHgj9qf/AsAD9nthNrQFsgSdmaqNEl73ml5uHSi68fuEZrPL6RvkVyKkt8tysujs7iybzruqVjKKSHJumDgo/uHRFMSEH5ETx/YnwLE7Sa1UrfXBBmhfU8vVw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771922007; c=relaxed/simple; bh=714/VEHB+aHM96UbWGHRo19d4d8Vpx5ZHuAp8X+3MzE=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=njYF171Ow+EsLJRVO2xTbBTu6XzIfi7cl8uMvkJQk9qJTZXxE8jnu6c2PV0WUfPO62wGGFj5siDyHVMvZgt76+twcN/Ilft8A0r4eYC0zlC3aoyeUVDrsNN0sV3MRODRmx/dyYgYkZzSoZ1lrDuEYiLOLHcgy/CpGh/9e3oqrYc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=sHgywnqN; 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="sHgywnqN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD22EC116D0; Tue, 24 Feb 2026 08:33:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771922007; bh=714/VEHB+aHM96UbWGHRo19d4d8Vpx5ZHuAp8X+3MzE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=sHgywnqNZG2y8hRdHK0WCgFIMxrcnO6tyOEL+V4AqmYkGm2OXK+eusrrXK6qNjFht 1GWRZpfVkCV4XpKO/jb2ToHam50hrP+5muZ6VxkoRA72Ue9MWHoVa0FavWPBDVOyvm CkLed9k9nCdID3Bf9Ww23Ptmn1Fzs7MPKPFZCrko6zJYvYYLsi4eQG6Z+FQYvgSD+p OSPCPsqUYHXWKXAToezW8tmqYkbjixa2KCti6MFh80OIuxK8ELZENNTjXUm95LGRhP oiNKOeurfbNPMii2kaNZ0HGRc9bYj8leEMrqF9UiRixFccm3ZA8UqcL2AnDbHbHxFc e9vr1Hp3Igk9g== Date: Tue, 24 Feb 2026 17:33:24 +0900 From: Masami Hiramatsu (Google) To: Cc: , , , , , , , Subject: Re: [PATCH 1/2] fgraph: fix thresh_return clear per-task notrace Message-Id: <20260224173324.3db58282e7afc817aaa13138@kernel.org> In-Reply-To: <20260221113007819YgrZsMGABff4Rc-O_fZxL@zte.com.cn> References: <202602211116123227p4Je6QELxr2byqvy9kTE@zte.com.cn> <20260221113007819YgrZsMGABff4Rc-O_fZxL@zte.com.cn> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-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 Sat, 21 Feb 2026 11:30:07 +0800 (CST) wrote: > From: Shengming Hu > > When tracing_thresh is enabled, function graph tracing uses > trace_graph_thresh_return() as the return handler. Unlike > trace_graph_return(), it did not clear the per-task > TRACE_GRAPH_NOTRACE flag set by the entry handler for > set_graph_notrace addresses. This could leave the task > permanently in "notrace" state and effectively disable > function graph tracing for that task. > > Mirror trace_graph_return()'s per-task notrace handling by > clearing TRACE_GRAPH_NOTRACE and returning early when set. > Good catch! Acked-by: Masami Hiramatsu (Google) Thanks! > Fixes: b84214890a9bc ("function_graph: Move graph notrace bit to > shadow stack global var") > Signed-off-by: Shengming Hu > --- > kernel/trace/trace_functions_graph.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c > index 1de6f1573..cbe43680c 100644 > --- a/kernel/trace/trace_functions_graph.c > +++ b/kernel/trace/trace_functions_graph.c > @@ -400,14 +400,15 @@ static void trace_graph_thresh_return(struct ftrace_graph_ret *trace, > struct fgraph_ops *gops, > struct ftrace_regs *fregs) > { > + unsigned long *task_var = fgraph_get_task_var(gops); > struct fgraph_times *ftimes; > struct trace_array *tr; > int size; > > ftrace_graph_addr_finish(gops, trace); > > - if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT)) { > - trace_recursion_clear(TRACE_GRAPH_NOTRACE_BIT); > + if (*task_var & TRACE_GRAPH_NOTRACE) { > + *task_var &= ~TRACE_GRAPH_NOTRACE; > return; > } > > -- > 2.25.1 -- Masami Hiramatsu (Google)