Re: [PATCH 07/18 v3] tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values

[Andrey Ryabinin <a.ryabinin@samsung.com>]

On 04/17/2015 04:51 PM, Steven Rostedt wrote:
> On Fri, 17 Apr 2015 09:29:02 -0400
> Steven Rostedt <rostedt@goodmis.org> wrote:
> 
>> On Fri, 17 Apr 2015 10:44:42 +0300
>> Andrey Ryabinin <a.ryabinin@samsung.com> wrote:
>>
>>  
>>> And kasan is not needed to debug this further.
>>> Just stick WARN_ON(ptr > call->print_fmt + strlen(call->print_fmt)) into the 'for' loop in update_event_printk().
>>
>> Thanks, although I think I found the bug with just inspection. I put in
>> WARN_ON(*ptr) at various locations to see if it triggers.
> 
> Yep, that's the issue.
> 
> Can you guys test this patch please:
> 

Tested-by: Andrey Ryabinin <a.ryabinin@samsung.com>

> -- Steve
> 
> diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
> index 39bcfc3f071d..97d454a4dbfb 100644
> --- a/kernel/trace/trace_events.c
> +++ b/kernel/trace/trace_events.c
> @@ -1753,6 +1753,8 @@ static void update_event_printk(struct ftrace_event_call *call,
>  				ptr++;
>  				/* Check for alpha chars like ULL */
>  			} while (isalnum(*ptr));
> +			if (!*ptr)
> +				break;
>  			/*
>  			 * A number must have some kind of delimiter after
>  			 * it, and we can ignore that too.
> @@ -1779,12 +1781,16 @@ static void update_event_printk(struct ftrace_event_call *call,
>  			do {
>  				ptr++;
>  			} while (isalnum(*ptr) || *ptr == '_');
> +			if (!*ptr)
> +				break;
>  			/*
>  			 * If what comes after this variable is a '.' or
>  			 * '->' then we can continue to ignore that string.
>  			 */
>  			if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
>  				ptr += *ptr == '.' ? 1 : 2;
> +				if (!*ptr)
> +					break;
>  				goto skip_more;
>  			}
>  			/*
>