instrumentation/syscalls/lttng-syscalls-extractor/lttng-syscalls-extractor.c

   1 /*
   2  * Copyright 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   3  * Copyright 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
   4  *
   5  * Dump syscall metadata to console.
   6  *
   7  * GPLv2 license.
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/kernel.h>
  12 #include <linux/types.h>
  13 #include <linux/list.h>
  14 #include <linux/err.h>
  15 #include <linux/slab.h>
  16 #include <linux/kallsyms.h>
  17 #include <linux/dcache.h>
  18 #include <linux/ftrace_event.h>
  19 #include <trace/syscall.h>
  20
  21 #ifndef CONFIG_FTRACE_SYSCALLS
  22 #error "You need to set CONFIG_FTRACE_SYSCALLS=y"
  23 #endif
  24
  25 static struct syscall_metadata **__start_syscalls_metadata;
  26 static struct syscall_metadata **__stop_syscalls_metadata;
  27
  28 static __init
  29 struct syscall_metadata *find_syscall_meta(unsigned long syscall)
  30 {
  31         struct syscall_metadata **iter;
  32
  33         for (iter = __start_syscalls_metadata;
  34                         iter < __stop_syscalls_metadata; iter++) {
  35                 if ((*iter)->syscall_nr == syscall)
  36                         return (*iter);
  37         }
  38         return NULL;
  39 }
  40
  41 int init_module(void)
  42 {
  43         struct syscall_metadata *meta;
  44         int i;
  45
  46         __start_syscalls_metadata = (void *) kallsyms_lookup_name("__start_syscalls_metadata");
  47         __stop_syscalls_metadata = (void *) kallsyms_lookup_name("__stop_syscalls_metadata");
  48
  49         for (i = 0; i < NR_syscalls; i++) {
  50                 int j;
  51
  52                 meta = find_syscall_meta(i);
  53                 if (!meta)
  54                         continue;
  55                 printk("syscall %s nr %d nbargs %d ",
  56                         meta->name, meta->syscall_nr, meta->nb_args);
  57                 printk("types: (");
  58                 for (j = 0; j < meta->nb_args; j++) {
  59                         if (j > 0)
  60                                 printk(", ");
  61                         printk("%s", meta->types[j]);
  62                 }
  63                 printk(") ");
  64                 printk("args: (");
  65                 for (j = 0; j < meta->nb_args; j++) {
  66                         if (j > 0)
  67                                 printk(", ");
  68                         printk("%s", meta->args[j]);
  69                 }
  70                 printk(")\n");
  71         }
  72         printk("SUCCESS\n");
  73
  74         return -1;
  75 }
  76
  77 void cleanup_module(void)
  78 {
  79 }
  80
  81 MODULE_LICENSE("GPL");