From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1758201AbcH3LaH (ORCPT <rfc822;w@1wt.eu>);
        Tue, 30 Aug 2016 07:30:07 -0400
Received: from mail-wm0-f67.google.com ([74.125.82.67]:36603 "EHLO
        mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1755452AbcH3LaG (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 30 Aug 2016 07:30:06 -0400
Date: Tue, 30 Aug 2016 13:30:00 +0200
From: Robert Richter <rric@kernel.org>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@kernel.org>,
        "H . Peter Anvin" <hpa@zytor.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org, Andy Lutomirski <luto@amacapital.net>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Steven Rostedt <rostedt@goodmis.org>, Brian Gerst <brgerst@gmail.com>,
        Kees Cook <keescook@chromium.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Byungchul Park <byungchul.park@lge.com>,
        Nilay Vaish <nilayvaish@gmail.com>,
        oprofile-list@lists.sourceforge.net
Subject: Re: [PATCH 2/6] oprofile/x86: add regs->ip to oprofile trace
Message-ID: <20160830113000.GO25086@rric.localdomain>
References: <cover.1472057064.git.jpoimboe@redhat.com>
 <6c745a83dbd69fc6857ef9b2f8be0f011d775936.1472057064.git.jpoimboe@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <6c745a83dbd69fc6857ef9b2f8be0f011d775936.1472057064.git.jpoimboe@redhat.com>
User-Agent: Mutt/1.5.23 (2014-03-12)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 24.08.16 11:50:15, Josh Poimboeuf wrote:
> dump_trace() doesn't add the interrupted instruction's address to the
> trace, so add it manually.  This makes the profile more useful, and also
> makes it more consistent with what perf profiling does.
> 
> Cc: Robert Richter <rric@kernel.org>
> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
> ---
>  arch/x86/oprofile/backtrace.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c
> index cb31a44..2ef6c8b 100644
> --- a/arch/x86/oprofile/backtrace.c
> +++ b/arch/x86/oprofile/backtrace.c
> @@ -114,9 +114,16 @@ x86_backtrace(struct pt_regs * const regs, unsigned int depth)
>  
>  	if (!user_mode(regs)) {
>  		unsigned long stack = kernel_stack_pointer(regs);
> -		if (depth)
> -			dump_trace(NULL, regs, (unsigned long *)stack, 0,
> -				   &backtrace_ops, &depth);
> +
> +		if (!depth)
> +			return;
> +
> +		oprofile_add_trace(regs->ip);
> +		if (!--depth)
> +			return;
> +
> +		dump_trace(NULL, regs, (unsigned long *)stack, 0,
> +			   &backtrace_ops, &depth);

Acked-by: Robert Richter <rric@kernel.org>

Adding oprofile-list in case someone has objections since this may
break userland tools.

Ingo, please apply the patch to tip once this series is ok to you.

Thanks,

-Robert

>  		return;
>  	}
>  
> -- 
> 2.7.4
>