linux-kernel - Re: [PATCH 3/6] x86/dumpstack: make printk_stack

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Message-ID: <1472059718.3746.154.camel@perches.com>
Date:   Wed, 24 Aug 2016 10:28:38 -0700
From:   Joe Perches <joe@...ches.com>
To:     Josh Poimboeuf <jpoimboe@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...nel.org>,
        "H . Peter Anvin" <hpa@...or.com>
Cc:     x86@...nel.org, linux-kernel@...r.kernel.org,
        Andy Lutomirski <luto@...capital.net>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Steven Rostedt <rostedt@...dmis.org>,
        Brian Gerst <brgerst@...il.com>,
        Kees Cook <keescook@...omium.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Frederic Weisbecker <fweisbec@...il.com>,
        Byungchul Park <byungchul.park@....com>,
        Nilay Vaish <nilayvaish@...il.com>
Subject: Re: [PATCH 3/6] x86/dumpstack: make printk_stack_address() more
 generally useful

On Wed, 2016-08-24 at 11:50 -0500, Josh Poimboeuf wrote:
> Change printk_stack_address() to be useful when called by an unwinder
> outside the context of dump_trace().
> 
> Specifically:
> 
> - printk_stack_address()'s 'data' argument is always used as the log
>   level string.  Make that explicit.

If this is true, and I'm not sure it is as I believe
there are static strings emitted like EOE and IRQ,
shouldn't this bubble up through the calling tree?

> - Call touch_nmi_watchdog().
[]
> diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
[]
> @@ -26,10 +26,11 @@ int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
>  static int die_counter;
>  
>  static void printk_stack_address(unsigned long address, int reliable,
> -		void *data)
> +				 char *log_lvl)
>  {
> +	touch_nmi_watchdog();
>  	printk("%s [<%p>] %s%pB\n",
> -		(char *)data, (void *)address, reliable ? "" : "? ",
> +		log_lvl, (void *)address, reliable ? "" : "? ",
>  		(void *)address);
>  }
>  
> @@ -148,7 +149,6 @@ static int print_trace_stack(void *data, char *name)
>   */
>  static int print_trace_address(void *data, unsigned long addr, int reliable)
>  {
> -	touch_nmi_watchdog();
>  	printk_stack_address(addr, reliable, data);
>  	return 0;
>  }

like for data here?