模块加载时出现unresolved symbol问题

restart

在redhat9.0，内核2.4.20下，用insmod加载模块出现unresolved symbol sys_call_table的错误，但在debian下，同样版本内核（编译时用的选现也差不多）没问题。
有谁知道怎么回事？
[code:1]
#include <linux/kernel.h>
#include <linux/module.h>
#include <sys/syscall.h>

#if CONFIG_MODVERSIONS==1
#define MODVERSIONS
#include <linux/modversions.h>
#endif

extern void *sys_call_table[];

/* Pointer to original chdir function, we must call this
   from our intercept function to allow for normal directory
   changes.  This will also be used to restore the syscall pointer
   when this module is unloaded. */
int (*old_sys_chdir)(const char *);

int (*sys_getuid)();

int sys_chdir_intercept(const char *path) {
  printk("%d %s\n", sys_getuid(), path);

  return old_sys_chdir(path);
}

int init_module() {
  // Outputted to your syslog
  printk("Module loaded..\n");

  old_sys_chdir = sys_call_table[__NR_chdir];
  sys_call_table[__NR_chdir] = sys_chdir_intercept;

  sys_getuid = sys_call_table[__NR_getuid];

  return 0;
}

void cleanup_module() {
  // Outputted to your syslog
  printk("Module unloaded..\n");

  sys_call_table[__NR_chdir] = old_sys_chdir;
}[/code:1]

restart

大哥们帮帮忙吧。。。

Dragonfly

if u use rh kernel like 2.4.20-8/9 it disable the system_call_table export. u need to reenable it or use a different kernel.