Re: [PATCH] ftrace: Add initialization check in trace_printk for *puts paths

["zhangwei(Jovi)" <jovi.zhangwei@huawei.com>]

On 2013/8/12 17:34, Jiri Olsa wrote:
> Adding initialization check in trace_printk for *puts
> paths, plus unifying the check for all related cases.
> 
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Frederic Weisbecker <fweisbec@gmail.com>
> Cc: Ingo Molnar <mingo@redhat.com>
> ---
Missed Signed-off-by tag?

>  kernel/trace/trace.c | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index 882ec1d..cb7cf96 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -126,6 +126,9 @@ static char *default_bootup_tracer;
>  
>  static bool allocate_snapshot;
>  
> +#define TRACE_PRINTK_DENIED \
> +	unlikely(tracing_selftest_running || tracing_disabled)
> +
>  static int __init set_cmdline_ftrace(char *str)
>  {
>  	strlcpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
> @@ -430,6 +433,9 @@ int __trace_puts(unsigned long ip, const char *str, int size)
>  	unsigned long irq_flags;
>  	int alloc;
>  
> +	if (TRACE_PRINTK_DENIED)
> +		return 0;
> +
>  	alloc = sizeof(*entry) + size + 2; /* possible \n added */
>  
>  	local_save_flags(irq_flags);
> @@ -470,6 +476,9 @@ int __trace_bputs(unsigned long ip, const char *str)
>  	unsigned long irq_flags;
>  	int size = sizeof(struct bputs_entry);
>  
> +	if (TRACE_PRINTK_DENIED)
> +		return 0;
> +
>  	local_save_flags(irq_flags);
>  	buffer = global_trace.trace_buffer.buffer;
>  	event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
> @@ -1757,7 +1766,7 @@ void trace_dump_stack(int skip)
>  {
>  	unsigned long flags;
>  
> -	if (tracing_disabled || tracing_selftest_running)
> +	if (TRACE_PRINTK_DENIED)
>  		return;
>  
>  	local_save_flags(flags);
> @@ -1976,7 +1985,7 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
>  	char *tbuffer;
>  	int len = 0, size, pc;
>  
> -	if (unlikely(tracing_selftest_running || tracing_disabled))
> +	if (TRACE_PRINTK_DENIED)
>  		return 0;
>  
>  	/* Don't pollute graph traces with trace_vprintk internals */
> @@ -2032,7 +2041,7 @@ __trace_array_vprintk(struct ring_buffer *buffer,
>  	unsigned long flags;
>  	char *tbuffer;
>  
> -	if (tracing_disabled || tracing_selftest_running)
> +	if (TRACE_PRINTK_DENIED)
>  		return 0;
>  
>  	/* Don't pollute graph traces with trace_vprintk internals */
>