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 #ifndef CONFIG_KALLSYMS_ALL
  26 #error "You need to set CONFIG_KALLSYMS_ALL=y"
  27 #endif
  28
  29 static struct syscall_metadata **__start_syscalls_metadata;
  30 static struct syscall_metadata **__stop_syscalls_metadata;
  31
  32 static __init
  33 struct syscall_metadata *find_syscall_meta(unsigned long syscall)
  34 {
  35         struct syscall_metadata **iter;
  36
  37         for (iter = __start_syscalls_metadata;
  38                         iter < __stop_syscalls_metadata; iter++) {
  39                 if ((*iter)->syscall_nr == syscall)
  40                         return (*iter);
  41         }
  42         return NULL;
  43 }
  44
  45 int init_module(void)
  46 {
  47         struct syscall_metadata *meta;
  48         int i;
  49
  50         __start_syscalls_metadata = (void *) kallsyms_lookup_name("__start_syscalls_metadata");
  51         __stop_syscalls_metadata = (void *) kallsyms_lookup_name("__stop_syscalls_metadata");
  52
  53         for (i = 0; i < NR_syscalls; i++) {
  54                 int j;
  55
  56                 meta = find_syscall_meta(i);
  57                 if (!meta)
  58                         continue;
  59                 printk("syscall %s nr %d nbargs %d ",
  60                         meta->name, meta->syscall_nr, meta->nb_args);
  61                 printk("types: (");
  62                 for (j = 0; j < meta->nb_args; j++) {
  63                         if (j > 0)
  64                                 printk(", ");
  65                         printk("%s", meta->types[j]);
  66                 }
  67                 printk(") ");
  68                 printk("args: (");
  69                 for (j = 0; j < meta->nb_args; j++) {
  70                         if (j > 0)
  71                                 printk(", ");
  72                         printk("%s", meta->args[j]);
  73                 }
  74                 printk(")\n");
  75         }
  76         printk("SUCCESS\n");
  77
  78         return -1;
  79 }
  80
  81 void cleanup_module(void)
  82 {
  83 }
  84
  85 MODULE_LICENSE("GPL");