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From: Thomas Gleixner <tglx@linutronix.de>
To: Alexandre Chartre <alexandre.chartre@oracle.com>,
	LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, Steven Rostedt <rostedt@goodmis.org>,
	Brian Gerst <brgerst@gmail.com>, Juergen Gross <jgross@suse.com>,
	Frederic Weisbecker <frederic@kernel.org>
Subject: Re: [patch part-II V2 11/13] x86/speculation/mds: Mark mds_user_clear_cpu_buffers() __always_inline
Date: Tue, 10 Mar 2020 17:38:01 +0100	[thread overview]
Message-ID: <87lfo85fo6.fsf@nanos.tec.linutronix.de> (raw)
In-Reply-To: <c9847c45-32b0-e5e6-1eb9-5f9e10814276@oracle.com>

Alexandre Chartre <alexandre.chartre@oracle.com> writes:
> On 3/8/20 11:24 PM, Thomas Gleixner wrote:
>> -static inline void mds_user_clear_cpu_buffers(void)
>> +static __always_inline void mds_user_clear_cpu_buffers(void)
>>   {
>>   	if (static_branch_likely(&mds_user_clear))
>>   		mds_clear_cpu_buffers();
>> 
>
> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
>
> I am just wondering if it would be worth defining a new function attribute to
> identify functions which shouldn't be trace/probe more clearly. For example:
>
> #define no_trace_and_probe __always_inline
>
> static no_trace_and_probe void mds_user_clear_cpu_buffers(void)
> {
>          ...
> }
>
> I am just concerned that overtime we might forgot that a function is defined
> __always_inline just because it shouldn't be traced/probed.

True, for exactly that reason we are reconsidering the whole annotation
business by putting stuff into a separate section so we get tools
support for finding things which escape. See the discussion at:

  https://lore.kernel.org/lkml/87mu8p797b.fsf@nanos.tec.linutronix.de/

Peter and I are working on this right now, so you might end up reviewing
this pile in different form yet another time :(

Thanks,

        tglx

  reply	other threads:[~2020-03-10 16:38 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-08 22:23 [patch part-II V2 00/13] x86/entry: Consolidation - Part II (syscalls) Thomas Gleixner
2020-03-08 22:24 ` [patch part-II V2 01/13] context_tracking: Ensure that the critical path cannot be instrumented Thomas Gleixner
2020-03-09 14:22   ` Frederic Weisbecker
2020-03-09 14:40     ` Thomas Gleixner
2020-03-10 10:12   ` Alexandre Chartre
2020-03-08 22:24 ` [patch part-II V2 02/13] x86/entry: Mark enter_from_user_mode() notrace and NOKPROBE Thomas Gleixner
2020-03-09 15:14   ` Frederic Weisbecker
2020-03-09 15:40     ` Thomas Gleixner
2020-03-11 22:21       ` Frederic Weisbecker
2020-03-10 10:15   ` Alexandre Chartre
2020-03-08 22:24 ` [patch part-II V2 03/13] x86/entry/32: Remove unused label restore_nocheck Thomas Gleixner
2020-03-10 10:16   ` Alexandre Chartre
2020-03-10 13:02   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-03-08 22:24 ` [patch part-II V2 04/13] x86/entry/64: Trace irqflags unconditionally as ON when returning to user space Thomas Gleixner
2020-03-10 10:25   ` Alexandre Chartre
2020-03-10 13:02   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-03-08 22:24 ` [patch part-II V2 05/13] x86/entry/common: Consolidate syscall entry code Thomas Gleixner
2020-03-08 22:24 ` [patch part-II V2 06/13] x86/entry/common: Mark syscall entry points notrace and NOKPROBE Thomas Gleixner
2020-03-13 15:12   ` Frederic Weisbecker
2020-03-08 22:24 ` [patch part-II V2 07/13] x86/entry: Move irq tracing on syscall entry to C-code Thomas Gleixner
2020-03-13 15:16   ` Frederic Weisbecker
2020-03-13 23:17     ` Thomas Gleixner
2020-03-08 22:24 ` [patch part-II V2 08/13] tracing: Provide lockdep less trace_hardirqs_on/off() variants Thomas Gleixner
2020-03-10 10:55   ` Alexandre Chartre
2020-03-10 11:08     ` Borislav Petkov
2020-03-10 11:21       ` Alexandre Chartre
2020-03-08 22:24 ` [patch part-II V2 09/13] x86/entry/common: Split hardirq tracing into lockdep and ftrace parts Thomas Gleixner
2020-03-10 11:20   ` Borislav Petkov
2020-03-10 13:40     ` Steven Rostedt
2020-03-10 13:28   ` Alexandre Chartre
2020-03-23  9:08   ` [x86/entry/common] bae397f6e7: WARNING:at_kernel/sched/cputime.c:#get_vtime_delta kernel test robot
2020-03-08 22:24 ` [patch part-II V2 10/13] x86/entry/common: Split prepare_exit_to_usermode() and syscall_return_slowpath() Thomas Gleixner
2020-03-10 13:37   ` Alexandre Chartre
2020-03-08 22:24 ` [patch part-II V2 11/13] x86/speculation/mds: Mark mds_user_clear_cpu_buffers() __always_inline Thomas Gleixner
2020-03-10 13:48   ` Alexandre Chartre
2020-03-10 16:38     ` Thomas Gleixner [this message]
2020-03-08 22:24 ` [patch part-II V2 12/13] x86/entry: Move irq flags tracing to prepare_exit_to_usermode() Thomas Gleixner
2020-03-10 14:03   ` Alexandre Chartre
2020-03-08 22:24 ` [patch part-II V2 13/13] x86/entry/common: Split irq tracing in prepare_exit_to_usermode() Thomas Gleixner
2020-03-10 14:09   ` Alexandre Chartre

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