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

   1 /* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
   2  *
   3  * lttng-syscalls-extractor.c
   4  *
   5  * Dump syscall metadata to console.
   6  *
   7  * Copyright 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  * Copyright 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/kernel.h>
  13 #include <linux/types.h>
  14 #include <linux/list.h>
  15 #include <linux/err.h>
  16 #include <linux/slab.h>
  17 #include <linux/kallsyms.h>
  18 #include <linux/dcache.h>
  19 #include <linux/ftrace_event.h>
  20 #include <trace/syscall.h>
  21 #include <asm/syscall.h>
  22
  23 #ifndef CONFIG_FTRACE_SYSCALLS
  24 #error "You need to set CONFIG_FTRACE_SYSCALLS=y"
  25 #endif
  26
  27 #ifndef CONFIG_KALLSYMS_ALL
  28 #error "You need to set CONFIG_KALLSYMS_ALL=y"
  29 #endif
  30
  31 static struct syscall_metadata **__start_syscalls_metadata;
  32 static struct syscall_metadata **__stop_syscalls_metadata;
  33
  34 static __init
  35 struct syscall_metadata *find_syscall_meta(unsigned long syscall)
  36 {
  37         struct syscall_metadata **iter;
  38
  39         for (iter = __start_syscalls_metadata;
  40                         iter < __stop_syscalls_metadata; iter++) {
  41                 if ((*iter)->syscall_nr == syscall)
  42                         return (*iter);
  43         }
  44         return NULL;
  45 }
  46
  47 int init_module(void)
  48 {
  49         struct syscall_metadata *meta;
  50         int i;
  51
  52         __start_syscalls_metadata = (void *) kallsyms_lookup_name("__start_syscalls_metadata");
  53         __stop_syscalls_metadata = (void *) kallsyms_lookup_name("__stop_syscalls_metadata");
  54
  55         for (i = 0; i < NR_syscalls; i++) {
  56                 int j;
  57
  58                 meta = find_syscall_meta(i);
  59                 if (!meta)
  60                         continue;
  61                 printk("syscall %s nr %d nbargs %d ",
  62                         meta->name, meta->syscall_nr, meta->nb_args);
  63                 printk("types: (");
  64                 for (j = 0; j < meta->nb_args; j++) {
  65                         if (j > 0)
  66                                 printk(", ");
  67                         printk("%s", meta->types[j]);
  68                 }
  69                 printk(") ");
  70                 printk("args: (");
  71                 for (j = 0; j < meta->nb_args; j++) {
  72                         if (j > 0)
  73                                 printk(", ");
  74                         printk("%s", meta->args[j]);
  75                 }
  76                 printk(")\n");
  77         }
  78         printk("SUCCESS\n");
  79
  80         return -1;
  81 }
  82
  83 void cleanup_module(void)
  84 {
  85 }
  86
  87 MODULE_LICENSE("GPL");