From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout.efficios.com (smtpout.efficios.com [167.114.26.122]) (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 103631849; Fri, 4 Oct 2024 00:13:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=167.114.26.122 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728000792; cv=none; b=GxMI0Aif3ke4IGA7Oem3/+jlbDGN1UDwr6GV/wMKgcOZZmNvgjbtzuqcMHOGOlC49lV5eEHMpawUR57xs44eF3ixtg7nqTFKfc/9QPuDGxCs2KnEzr6NUGOPkNeTKNLhy8lk/WwYvucmEfKsLFnIBzQQVF69G5NNk3ggg+PxyOs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728000792; c=relaxed/simple; bh=Uf2DyIAPcgBpMm6RGTIKd696N0dyton8J3Ol+EHVsp4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=abgaQ3zPB/ALuRUGNzHu4q4N0elZABvyDuLJ0mDTGbmVsMSbsgc9PUdA+qWOe7gg0Wll/W5CM50qn/iy7EZUzoOeH/qqk1iHgCP22vy2f0XpGYVakr6VoNFjavAEhkhHP6jcveMbB5evQwOtsR0OOp7HuaFkp5eaQJAYWUzpNTc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com; spf=pass smtp.mailfrom=efficios.com; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b=J1A4bD9R; arc=none smtp.client-ip=167.114.26.122 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=efficios.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b="J1A4bD9R" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=efficios.com; s=smtpout1; t=1728000788; bh=Uf2DyIAPcgBpMm6RGTIKd696N0dyton8J3Ol+EHVsp4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=J1A4bD9RdfZCJjWdfHXeAs/sHyhCzm1THQfI5PbXzaWU5J+qwWVy2cP/j63UBgJ0S 4s8AiyZaFnmXN0a6XVfQg8gClp7xZDkGv1n8ZAP79o9T2ODHxEBcTi/Mk9NaKb+97D NWNAvl8PM5SStMkwBtEqpimu5oRjJsoE4vrO4mRWRrJPqxb0aH/XHyXSfhrK+4EvEl HdRVZdyeIrLrJzVTFeQgjYogvhKd4Jf+aCpcTzk5oWYKL6/11Wrg1i9yLe4ZbjMqyf JnSXT4nHLdzaeWyG8cZeSAaUqj6Pax6t/71UR9meBny54BVBoWiulwtK9ysTUw935K y6nO4IEAEbzXw== Received: from [192.168.18.201] (unknown [198.16.233.254]) by smtpout.efficios.com (Postfix) with ESMTPSA id 4XKTXN3vqDzBPL; Thu, 3 Oct 2024 20:13:08 -0400 (EDT) Message-ID: Date: Thu, 3 Oct 2024 20:11:06 -0400 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 6/8] tracing/ftrace: Add might_fault check to syscall probes To: Steven Rostedt Cc: Masami Hiramatsu , linux-kernel@vger.kernel.org, Peter Zijlstra , Alexei Starovoitov , Yonghong Song , "Paul E . McKenney" , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Namhyung Kim , Andrii Nakryiko , bpf@vger.kernel.org, Joel Fernandes , linux-trace-kernel@vger.kernel.org, Michael Jeanson References: <20241003151638.1608537-1-mathieu.desnoyers@efficios.com> <20241003151638.1608537-7-mathieu.desnoyers@efficios.com> <20241003183649.0290f0d1@gandalf.local.home> From: Mathieu Desnoyers Content-Language: en-US In-Reply-To: <20241003183649.0290f0d1@gandalf.local.home> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2024-10-04 00:36, Steven Rostedt wrote: > On Thu, 3 Oct 2024 11:16:36 -0400 > Mathieu Desnoyers wrote: > >> diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h >> index 0228d9ed94a3..e0d4850b0d77 100644 >> --- a/include/trace/trace_events.h >> +++ b/include/trace/trace_events.h >> @@ -446,6 +446,7 @@ __DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \ >> static notrace void \ >> trace_event_raw_event_##call(void *__data, proto) \ >> { \ >> + might_fault(); \ > > I don't think we want "might_fault()" here, as this is called for every > tracepoint that is created by the TRACE_EVENT() macro. That means, there's > going to be plenty of locations this gets called at that do not allow faults. Here is the full context where this line applies: #undef DECLARE_EVENT_SYSCALL_CLASS #define DECLARE_EVENT_SYSCALL_CLASS(call, proto, args, tstruct, assign, print) \ __DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \ PARAMS(assign), PARAMS(print)) \ static notrace void \ trace_event_raw_event_##call(void *__data, proto) \ { \ might_fault(); \ guard(preempt_notrace)(); \ do_trace_event_raw_event_##call(__data, args); \ } Not an issue, since it's only for syscall tracepoints. Thanks, Mathieu > > -- Steve > > >> guard(preempt_notrace)(); \ >> do_trace_event_raw_event_##call(__data, args); \ >> } -- Mathieu Desnoyers EfficiOS Inc. https://www.efficios.com