MARKER mechanism, try 2

[Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>]

Hi Ingo,

I played a bit with my marker proof of concept, it now makes a lot more sense.
Here it is. Comments are welcome.

It supports 5 modes :

- marker becomes nothing
- marker calls printk
- marker calls a tracer
- marker puts a symbol (for kprobe)
- marker puts a symbol and 5 NOPS for a jump probe.


Mathieu

-----BEGIN-----


/* Macro example for instrumentation
 *
 * Version 0.0.2
 * 
 * Mathieu Desnoyers mathieu.desnoyers@polymtl.ca
 *
 * This is released under the GPL v2 (or better) license.
 */

#include <stdio.h>

/* This is an example of noop, get this from the current arch header */
#define GENERIC_NOP1    ".byte 0x90\n"


/* PUT THIS IN A INCLUDE/LINUX HEADER */

#define __stringify_1(x) #x //see include/linux/stringify.h
#define __stringify(x) __stringify_1(x)

#define KBUILD_BASENAME basename
#define KBUILD_MODNAME modulename

#define MARK_SYM(event)	\
  __asm__ ( "__mark_"__stringify(KBUILD_MODNAME)"_"__stringify(KBUILD_BASENAME)"_"#event":" )

/* With config menu mutual exclusion of choice */
#ifdef CONFIG_NOLOG
#define MARK(event, format, args...)
#endif

#ifdef CONFIG_PRINTLOG
#define MARK(event, format, args...) \
	printf(format, ##args);
#endif

#ifdef CONFIG_TRACELOG
#define MARK(event, format, args...) \
	trace_##event( args );
#endif

#ifdef CONFIG_KPROBELOG
#define MARK(event, format, args...) \
  { \
    MARK_SYM(event); \
  }
#endif

#ifdef CONFIG_JUMPPROBELOG
#define MARK(event, format, args...) \
  { \
    MARK_SYM(event); \
	  __asm__ ( GENERIC_NOP1 GENERIC_NOP1 GENERIC_NOP1 GENERIC_NOP1 GENERIC_NOP1 ); \
  }
#endif



/* PUT THIS IN A HEADER NEAR THE .C FILE */
#ifdef CONFIG_TRACELOG
static inline void trace_eventname(int a, char *b)
{
	/* log.... */
	printf("Tracing event : first arg %d, second arg %s", a, b);
}
#endif

/* PUT THIS IN THE .C FILE */

int main()
{
	int myint = 55;
	char * mystring = "blah";
	
	MARK(eventname, "%d %s", myint, mystring);
	
	printf("\n");

	return 0;
}





-----END-----



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