Hi All,
I tried to understand the code below but could not. Can any one please explain me.
Regards,
Mohan.
#include <linux/syscall.h>
#include <asm/unistd.h>
static void **sys_call_table;
//nearest exported symbol to syscalls in my kernel,
//i hope in others kernels too
//but in other form you can look at your kernel sources
extern void *system_utsname;
....
static int locate_sys_call_table(void) {
unsigned long *begin;
int i;
begin=(unsigned long *) &system_utsname;
for (i=0;i<1024;i++) {
if (*(begin+i)==(unsigned long) sys_socketcall) {
sys_call_table=(void *) (begin+i-__NR_socketcall);
//are you sure?
if (sys_call_table[__NR_exit]==(void *) sys_exit) {
printk("success: located sys_call_table: %X\n",(unsigned
int) sys_call_table);
return(1);
}
}
}
return(0);
}
int __init init_exportmodule (void)
{
if (!locate_sys_call_table()) {
// ... cry again and return error
}
//.....sys_call_table[] works now!!
//......do something like export symbol
//.... or intercept any syscall
}
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