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 55447284689; Wed, 28 Jan 2026 22:29:32 +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=1769639372; cv=none; b=srvNUv60M6nUe9lSb6MyKLqgavjDy+48VAbvhrpHI4Ej5cInlCbaQjBLQJyXtkZ/K57cMdXtrxRpWy9iguyRfajIwk1bVeHEekDZusQvUcbe8Tqj/0Dyan1yHpKUNtOKwPYodrU6On2iaVv+vWyt4jmlDOKyN8d9uDYr7KGM2qU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769639372; c=relaxed/simple; bh=a0Ddc1sM8tlaUXYOPYAnFNHQc1jvPGEdsW9X+42V578=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=EUAVWmgOBKM8sFxkPNYahzWSgutv0PZn/FFwRciPfNQGI4etKwtSMW+gphcQe3BA1o/c69TYQsF+IFLhdIHQuhUM+sA6zuAK1izmGfhN6GfbV7AQCts4n5Zzfi53s5PnAgXFwbbEekY+JDuwvs7IFotEDpQTwLjzJmoqSeDmW2M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SJyx5ETe; 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="SJyx5ETe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DE12CC4CEF1; Wed, 28 Jan 2026 22:29:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769639372; bh=a0Ddc1sM8tlaUXYOPYAnFNHQc1jvPGEdsW9X+42V578=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=SJyx5ETeeFXIxljN9Qea1B15cBU8SVVXXIgRbVrSN8RYjlmz3AsJtHksRpsq2/l/9 wXETTKIpwrHDCDTMLmcAHuNPj2ai/z0XUZFCurH8/aMUwhPj+jeK1nd/iteefYsNnP NKKxn3lw7S06muMLmmBnMTzWEI5We/FZXnhDKpz8D+UyQlWYinllyxSGH6wb1hTS0D S7LOiZL++0aRDRJ/4EXK4GXEfzHw5IfW2urOGVxWoI5kAOFcWWYh2XcKDyxcpGE39Z fZOyZwQlXEhalzhJA+5k+7dJZdk9WhK8Pl9ini9Vu3vahXYAvRK1jC0gsG/Qo1AF3N oUVSIpSiYDGHA== Date: Thu, 29 Jan 2026 07:29:28 +0900 From: Masami Hiramatsu (Google) To: Breno Leitao Cc: Oleg Nesterov , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , James Clark , Andrii Nakryiko , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, kernel-team@meta.com, stable@vger.kernel.org Subject: Re: [PATCH v2] uprobes: fix incorrect lockdep condition in filter_chain() Message-Id: <20260129072928.da41ab0a2e71da86dd4cd4b8@kernel.org> In-Reply-To: <20260128-uprobe_rcu-v2-1-994ea6d32730@debian.org> References: <20260128-uprobe_rcu-v2-1-994ea6d32730@debian.org> 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 Wed, 28 Jan 2026 10:16:11 -0800 Breno Leitao wrote: > The list_for_each_entry_rcu() in filter_chain() uses > rcu_read_lock_trace_held() as the lockdep condition, but the function > holds consumer_rwsem, not the RCU trace lock. > > This gives me the following output when running with some locking debug > option enabled: > > kernel/events/uprobes.c:1141 RCU-list traversed in non-reader section!! > filter_chain > register_for_each_vma > uprobe_unregister_nosync > __probe_event_disable > > Remove the incorrect lockdep condition since the rwsem provides > sufficient protection for the list traversal. > Looks good to me. Acked-by: Masami Hiramatsu (Google) Thanks, > Cc: stable@vger.kernel.org > Fixes: cc01bd044e6a ("uprobes: travers uprobe's consumer list locklessly under SRCU protection") > Acked-by: Oleg Nesterov > Acked-by: Andrii Nakryiko > Signed-off-by: Breno Leitao > --- > Changes in v2: > - updated the "fixes" tag (Oleg) > - Link to v1: https://patch.msgid.link/20260128-uprobe_rcu-v1-1-d41316763799@debian.org > --- > kernel/events/uprobes.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c > index d546d32390a81..726d13b375f3d 100644 > --- a/kernel/events/uprobes.c > +++ b/kernel/events/uprobes.c > @@ -1138,7 +1138,7 @@ static bool filter_chain(struct uprobe *uprobe, struct mm_struct *mm) > bool ret = false; > > down_read(&uprobe->consumer_rwsem); > - list_for_each_entry_rcu(uc, &uprobe->consumers, cons_node, rcu_read_lock_trace_held()) { > + list_for_each_entry(uc, &uprobe->consumers, cons_node) { > ret = consumer_filter(uc, mm); > if (ret) > break; > > --- > base-commit: 1f97d9dcf53649c41c33227b345a36902cbb08ad > change-id: 20260128-uprobe_rcu-e21867ab4c1b > > Best regards, > -- > Breno Leitao > -- Masami Hiramatsu (Google)