static void init_kprobe_prohibited_area(void)
{
static int once = 0;
if (once > 0)
return;
once = 1;
core_kernel_text_start = find_kernel_symbol("_stext");
core_kernel_text_end = find_kernel_symbol("_etext");
kprobes_text_start = find_kernel_symbol("__kprobes_text_start");
kprobes_text_end = find_kernel_symbol("__kprobes_text_end");
}
int cp_symbol_build_func(struct cp_ctype *type, const char *fname, int fn_size)
{
int i = 1, arg_nr, id;
int *argsym_id_arr;
csymbol nfcs;
csymbol_func *fcs;
if (cts.top == 0 || fn_size < 0 || !fname) {
cp_error("invalid function definition.\n");
}
argsym_id_arr = NULL;
memset(&nfcs, 0, sizeof(csymbol));
csym_type(&nfcs) = FFI_FUNC;
strncpy(csym_name(&nfcs), fname, fn_size);
fcs = csym_func(&nfcs);
fcs->has_var_arg = type->has_var_arg;
/* Type needed for handling variable args handle */
if (fcs->has_var_arg && !ctype_lookup_type("void *"))
cp_symbol_build_pointer(ctype_lookup_type("void"));
/* Fetch start address of function */
fcs->addr = (void *)find_kernel_symbol(csym_name(&nfcs));
if (!fcs->addr)
cp_error("wrong function address for %s\n", csym_name(&nfcs));
/* bottom of the stack is return type */
fcs->ret_id = ct_stack_ct(0)->ffi_cs_id;
/* the rest is argument type */
if (cts.top == 1) {
/* function takes no argument */
arg_nr = 0;
} else {
arg_nr = cts.top - 1;
argsym_id_arr = malloc(arg_nr * sizeof(int));
if (!argsym_id_arr)
cp_error("failed to allocate memory for function args.\n");
for (i = 0; i < arg_nr; i++) {
argsym_id_arr[i] = ct_stack_ct(i+1)->ffi_cs_id;
}
}
fcs->arg_nr = arg_nr;
fcs->arg_ids = argsym_id_arr;
id = cp_ctype_reg_csymbol(&nfcs);
/* clear stack since we have consumed all the ctypes */
ctype_stack_reset();
return id;
}