From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03E85C38A2A for ; Fri, 8 May 2020 06:20:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D156B20870 for ; Fri, 8 May 2020 06:20:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588918812; bh=I3X2enS2OqLjtPhgnubWwOb3w5o44g1ByLACf1WhlIk=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=kiH2/VMSh6MY6jZdctUpNI1e+Ia4Cj15+tj370fHWmwRVeMJhTLZUBA9xLPO5AoP6 lRK3dLWUPjCVipqh6Kr+96VGurH63ze4mKMKgLft/3eqtHrqOOEK7AT6AhQYTwIHs+ va6cQn9l3lGwjAeo3mrQLDTLUVCyJhI2Cs0TRx08= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726817AbgEHGTu (ORCPT ); Fri, 8 May 2020 02:19:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:48956 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726009AbgEHGTu (ORCPT ); Fri, 8 May 2020 02:19:50 -0400 Received: from devnote2 (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 240ED20708; Fri, 8 May 2020 06:19:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588918789; bh=I3X2enS2OqLjtPhgnubWwOb3w5o44g1ByLACf1WhlIk=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=YsO4UX1c8zXM/aL4ShYW8RFh9OLHwnW3x5vIG+sRyAgFflcXgoUH9kMgEb2LONKNT Avr6AK+zZd6BCfYvV8FqDWKXUZLdJ9VsAQfOTaQYJBZt/QBOL8nztYq70Rhdb63PwZ SDHMHj0bDctVaeF7WH7g0Zx4BbL4amt7pg753Ujo= Date: Fri, 8 May 2020 15:19:42 +0900 From: Masami Hiramatsu To: Thomas Gleixner Cc: LKML , x86@kernel.org, "Paul E. McKenney" , Andy Lutomirski , Alexandre Chartre , Frederic Weisbecker , Paolo Bonzini , Sean Christopherson , Masami Hiramatsu , Petr Mladek , Steven Rostedt , Joel Fernandes , Boris Ostrovsky , Juergen Gross , Brian Gerst , Mathieu Desnoyers , Josh Poimboeuf , Will Deacon , "Peter Zijlstra (Intel)" Subject: Re: [patch V4 part 1 33/36] x86,tracing: Robustify ftrace_nmi_enter() Message-Id: <20200508151942.c6bfdb20ee94858c9d147f07@kernel.org> In-Reply-To: <20200505134101.340485295@linutronix.de> References: <20200505131602.633487962@linutronix.de> <20200505134101.340485295@linutronix.de> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 05 May 2020 15:16:35 +0200 Thomas Gleixner wrote: > From: Peter Zijlstra > > ftrace_nmi_enter() > trace_hwlat_callback() > trace_clock_local() > sched_clock() > paravirt_sched_clock() > native_sched_clock() > > All must not be traced or kprobed, it will be called from do_debug() > before the kprobe handler. > Looks good to me. Reviewed-by: Masami Hiramatsu Thank you, > Signed-off-by: Peter Zijlstra (Intel) > Signed-off-by: Thomas Gleixner > Acked-by: Steven Rostedt (VMware) > --- > arch/x86/include/asm/paravirt.h | 2 +- > arch/x86/kernel/tsc.c | 4 ++-- > include/linux/ftrace_irq.h | 4 ++-- > kernel/trace/trace_clock.c | 3 ++- > kernel/trace/trace_hwlat.c | 2 +- > 5 files changed, 8 insertions(+), 7 deletions(-) > > --- a/arch/x86/include/asm/paravirt.h > +++ b/arch/x86/include/asm/paravirt.h > @@ -17,7 +17,7 @@ > #include > #include > > -static inline unsigned long long paravirt_sched_clock(void) > +static __always_inline unsigned long long paravirt_sched_clock(void) > { > return PVOP_CALL0(unsigned long long, time.sched_clock); > } > --- a/arch/x86/kernel/tsc.c > +++ b/arch/x86/kernel/tsc.c > @@ -207,7 +207,7 @@ static void __init cyc2ns_init_secondary > /* > * Scheduler clock - returns current time in nanosec units. > */ > -u64 native_sched_clock(void) > +noinstr u64 native_sched_clock(void) > { > if (static_branch_likely(&__use_tsc)) { > u64 tsc_now = rdtsc(); > @@ -240,7 +240,7 @@ u64 native_sched_clock_from_tsc(u64 tsc) > /* We need to define a real function for sched_clock, to override the > weak default version */ > #ifdef CONFIG_PARAVIRT > -unsigned long long sched_clock(void) > +noinstr unsigned long long sched_clock(void) > { > return paravirt_sched_clock(); > } > --- a/include/linux/ftrace_irq.h > +++ b/include/linux/ftrace_irq.h > @@ -7,7 +7,7 @@ extern bool trace_hwlat_callback_enabled > extern void trace_hwlat_callback(bool enter); > #endif > > -static inline void ftrace_nmi_enter(void) > +static __always_inline void ftrace_nmi_enter(void) > { > #ifdef CONFIG_HWLAT_TRACER > if (trace_hwlat_callback_enabled) > @@ -15,7 +15,7 @@ static inline void ftrace_nmi_enter(void > #endif > } > > -static inline void ftrace_nmi_exit(void) > +static __always_inline void ftrace_nmi_exit(void) > { > #ifdef CONFIG_HWLAT_TRACER > if (trace_hwlat_callback_enabled) > --- a/kernel/trace/trace_clock.c > +++ b/kernel/trace/trace_clock.c > @@ -22,6 +22,7 @@ > #include > #include > #include > +#include > > /* > * trace_clock_local(): the simplest and least coherent tracing clock. > @@ -29,7 +30,7 @@ > * Useful for tracing that does not cross to other CPUs nor > * does it go through idle events. > */ > -u64 notrace trace_clock_local(void) > +u64 noinstr trace_clock_local(void) > { > u64 clock; > > --- a/kernel/trace/trace_hwlat.c > +++ b/kernel/trace/trace_hwlat.c > @@ -139,7 +139,7 @@ static void trace_hwlat_sample(struct hw > #define init_time(a, b) (a = b) > #define time_u64(a) a > > -void trace_hwlat_callback(bool enter) > +noinstr void trace_hwlat_callback(bool enter) > { > if (smp_processor_id() != nmi_cpu) > return; > -- Masami Hiramatsu