trunk/tests/markers/probe-string.c

   1 /* probe.c
   2  *
   3  * Loads a function at a marker call site.
   4  *
   5  * (C) Copyright 2006 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
   6  *
   7  * This file is released under the GPLv2.
   8  * See the file COPYING for more details.
   9  */
  10
  11 #include <linux/marker.h>
  12 #include <linux/module.h>
  13 #include <linux/kallsyms.h>
  14
  15
  16 int value;
  17 void *ptr;
  18
  19 /* function to install */
  20 void do_mark1(const char *format, ...)
  21 {
  22         unsigned int i = 0;
  23         va_list ap;
  24         int control = 0;
  25
  26         va_start(ap, format);
  27         while(1) {
  28                 if(control) {
  29                         switch(format[i]) {
  30                                 case '\0' :
  31                                         return;
  32                                 case 'd' :
  33                                         value = va_arg(ap, int);
  34                                 case 'p' :
  35                                         ptr = va_arg(ap, void*);
  36                         }
  37                         control = 0;
  38                 } else {
  39                         switch(format[i]) {
  40                                 case '%' :
  41                                         control = 1;
  42                                         break;
  43                                 case '\0' :
  44                                         return;
  45                                 default:
  46                                         control = 0;
  47                         }
  48                 }
  49                 i++;
  50         }
  51         va_end(ap);
  52 }
  53
  54 int init_module(void)
  55 {
  56         int result;
  57         result = marker_set_probe("subsys_mark1", NULL,
  58                         do_mark1);
  59         if(!result) goto end;
  60
  61         return 0;
  62
  63 end:
  64         marker_remove_probe(do_mark1);
  65         return -EPERM;
  66 }
  67
  68 void cleanup_module(void)
  69 {
  70         marker_remove_probe(do_mark1);
  71 }
  72
  73 MODULE_LICENSE("GPL");
  74 MODULE_AUTHOR("Mathieu Desnoyers");
  75 MODULE_DESCRIPTION("Probe");