Re: [PATCH 1/3] x86, tracing: fix x86 exceptions trace header

[Steven Rostedt]

On Fri, 22 Jul 2016 11:03:11 -0700
Dave Hansen <dave@xxxxxxxx> wrote:

> From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> 
> The various tracing headers pass some variables into the tracing
> code itself to indicate things like the name of the tracing
> directory where the tracepoints should be located in debugfs.
> The general pattern is to #undef them before redefining them.
> 
> But, if all instances don't do this, and two different trace
> headers get included in the same file, you'll get macro
> redefinition compile errors.
> 
> Fix up the x86 exception tracing code to properly #undef one of
> its macros.
> 
> Note that this isn't a problem in practice until the next patch
> in this series is applied and adds a #include of the FPU
> tracing header.
> 
> Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> ---
> 
>  b/arch/x86/include/asm/trace/exceptions.h |    1 +
>  1 file changed, 1 insertion(+)
> 
> diff -puN arch/x86/include/asm/trace/exceptions.h~pkeys-899-fix-exceptions-trace-define arch/x86/include/asm/trace/exceptions.h
> --- a/arch/x86/include/asm/trace/exceptions.h~pkeys-899-fix-exceptions-trace-define	2016-07-22 10:52:32.543331471 -0700
> +++ b/arch/x86/include/asm/trace/exceptions.h	2016-07-22 10:52:32.546331607 -0700
> @@ -45,6 +45,7 @@ DEFINE_PAGE_FAULT_EVENT(page_fault_kerne
>  
>  #undef TRACE_INCLUDE_PATH
>  #define TRACE_INCLUDE_PATH .
> +#undef  TRACE_INCLUDE_FILE
>  #define TRACE_INCLUDE_FILE exceptions
>  #endif /*  _TRACE_PAGE_FAULT_H */
>  
> _

Acked-by: Steven Rostedt <rostedt@xxxxxxxxxxx>

I had to check, but my sample code in
samples/trace_events/trace-events-sample.h does indeed include the
#undef of TRACE_INCLUDE_FILE too.

-- Steve