Re: [PATCH v2] cxl/trace: Properly initialize cxl_poison region name

[Steven Rostedt <rostedt@goodmis.org>]

On Thu, 14 Mar 2024 15:36:48 -0700
Alison Schofield <alison.schofield@intel.com> wrote:

> > diff --git a/include/trace/stages/stage5_get_offsets.h b/include/trace/stages/stage5_get_offsets.h
> > index e30a13be46ba..dfae18d8f4df 100644
> > --- a/include/trace/stages/stage5_get_offsets.h
> > +++ b/include/trace/stages/stage5_get_offsets.h
> > @@ -9,6 +9,13 @@
> >  #undef __entry
> >  #define __entry entry
> >    
> 
> +#ifndef STAGE5_H_INCLUDED
> +#define STAGE5_H_INCLUDED
> > +static inline const char *__string_src(const char *str)
> > +{
> > +	if (!str)
> > +		return "(null)";
> > +	return str;
> > +}  
> +#endif /* STAGE5_H_INCLUDED */
> 
> Happy to try it out...
> 
> Your diff, with the ifdef above, makes the compiler happy and it functions
> as wanted - no garbage in the fields.

Hmm, I guess the:

 strlen((src ? (const char *)(src) : NULL) ? (src ? (const char *) src : NULL)) ? "(null)")) + 1

was too complex for the compiler, where as:

 strlen(__string_str((str ? (const char *)(src) : NULL))) + 1

is not.

Perhaps I should add this change. I would still submit your change with the
"" as that needs to be backported, but this probably does not.

Thanks for testing it out.

-- Steve

> 
> > +
> >  /*
> >   * Fields should never declare an array: i.e. __field(int, arr[5])
> >   * If they do, it will cause issues in parsing and possibly corrupt the
> > @@ -47,7 +54,7 @@
> >  
> >  #undef __string
> >  #define __string(item, src) __dynamic_array(char, item,			\
> > -		    strlen((src) ? (const char *)(src) : "(null)") + 1)
> > +		    strlen(__string_src(src)) + 1)
> >  
> >  #undef __string_len
> >  #define __string_len(item, src, len) __dynamic_array(char, item, (len) + 1)