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 29145380; Wed, 19 Mar 2025 00:06:53 +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=1742342814; cv=none; b=QITLMUaeOwbXMo+ZAiGPUYRYqwvhSHiNWIxrWR4nIZF5komoU2KHFl5kJIW4ybubcTzU7FLzJjEnyApord85qG8BxQRrJpDjmfDACg8gdejwG7MD1zp/1mdcHJ+aG7jgE7hhFm44BVn253SJUCYmnjvdzrLONfzEe3EHupgBvsE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742342814; c=relaxed/simple; bh=gcN/zzGvLZN1B7SFP4Y0Bx9RKBrFoJ68+g/rSpOfAqo=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=BCDQBkkysUG++mCWp55Y1RR0uE+fEXF8pFBXfvWXzDcyv0yneGsJt+3x6fVJyJ/s7oaCTBfEYN1cbIASCJmXfUUu8mqi4dRrbh5RO6szHDt+EqSFEth6REHFiEbV2XPOBwkj6movVUAwRY+XuebQM076B68r+PWFfsG/NsiW+0U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Rj6JlJvy; 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="Rj6JlJvy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 453EBC4CEE9; Wed, 19 Mar 2025 00:06:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742342813; bh=gcN/zzGvLZN1B7SFP4Y0Bx9RKBrFoJ68+g/rSpOfAqo=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Rj6JlJvyeptJ6QULtFZB+Y+rkaauesly+lIS6Y38HFU0tj0s7ylMfVPfcbk1XYKMl 3J7Uvk8Vy2PtnskV5nf19oo8Er3zUEJYEllMb69PTLt50eblA1HiE27/tBgX8ktuHs vg0mbTKajx1YitI8wWK6V8UMlk7R29RpqfI16bVqYB52K5osmu9sOc0ONHT96zVX3a mp9dZJJOOFqGntH4/NrwBHEOUiLGrI9FV8RGLLt0j9JSKsJNGUbEljB1BpPNZLAizq Lvi4/Fbtoed/Cn1KyTVlE+NmdUveEKx3B55psnQ5TcEAe0FR0J/OyUeRXK7JhW11qQ QMR8fxQhTe1tA== Date: Wed, 19 Mar 2025 09:06:50 +0900 From: Masami Hiramatsu (Google) To: Miaoqian Lin Cc: Steven Rostedt , Mathieu Desnoyers , Tom Zanussi , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: Re: [PATCH] tracing: Fix error handling in event_trigger_parse Message-Id: <20250319090650.fe63164eac3ac32bb559ffc8@kernel.org> In-Reply-To: <20250318112737.4174-1-linmq006@gmail.com> References: <20250318112737.4174-1-linmq006@gmail.com> 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 Tue, 18 Mar 2025 19:27:37 +0800 Miaoqian Lin wrote: > According to event_trigger_alloc() doc, event_trigger_free() should be > used to free an event_trigger_data object. This fixes a mismatch introduced > when kzalloc was replaced with event_trigger_alloc without updating > the corresponding deallocation calls. > Hmm, it seems more complicated problems are there. e.g. in `remove = true` case, since the trigger_data is not initialized (no event_trigger_init()), the `trigger_data->ref` is 0. Thus, ; static void event_trigger_free(struct event_trigger_data *data) { if (WARN_ON_ONCE(data->ref <= 0)) return; data->ref--; if (!data->ref) trigger_data_free(data); } this will never call `trigger_data_free(data)`. But latter part(after out_free) seems correct. Tom, could you check it? Thank you, > Fixes: e1f187d09e11 ("tracing: Have existing event_command.parse() implementations use helpers") > Signed-off-by: Miaoqian Lin > --- > kernel/trace/trace_events_trigger.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c > index d45448947094..8389314b8c2d 100644 > --- a/kernel/trace/trace_events_trigger.c > +++ b/kernel/trace/trace_events_trigger.c > @@ -995,7 +995,7 @@ event_trigger_parse(struct event_command *cmd_ops, > > if (remove) { > event_trigger_unregister(cmd_ops, file, glob+1, trigger_data); > - kfree(trigger_data); > + event_trigger_free(trigger_data); > ret = 0; > goto out; > } > @@ -1022,7 +1022,7 @@ event_trigger_parse(struct event_command *cmd_ops, > > out_free: > event_trigger_reset_filter(cmd_ops, trigger_data); > - kfree(trigger_data); > + event_trigger_free(trigger_data); > goto out; > } > > -- > 2.39.5 (Apple Git-154) > > -- Masami Hiramatsu (Google)