编写一个新的系统调用 [英] Writing a new system call
问题描述
我一直在试图写在树莓的内核新的系统调用(称为sys_defclose),但在编译我得到这个错误:
弓/ ARM /核心/内置in.o:在功能`__sys_trace_return:
。:(文字+ 0xd50):未定义的参考`sys_defclose
我已经修改以下文件:
-include / Linux的/ syscalls.h:这里我把我的系统调用的原型
-arch / ARM /有/ ASM / unistd.h中:这里我把系统调用表的新原料:
的#define __NR_sys_defclose(__NR_SYSCALL_BASE + 380)
-arch / ARM /内核/ calls.S:这里我把:
CALL(sys_defclose)
-i把在arch / ARM /内核sys_defclose的来源,我有新行修改makefile文件在同一目录
OBJ-Y + = sys_defclose.o
内核版本为树莓派3.6。
有人可以解释我如何解决这个错误?
谢谢
这是我的系统调用执行
静态结构的task_struct * get_task_by_pid(将为pid_t PID)
{
返回pid_task(find_pid_ns(PID,task_active_pid_ns(电流)),PIDTYPE_PID);
}静态无效close_files(结构files_struct *文件)
{
INT I,J;
结构fdtable * FDT; J = 0; rcu_read_lock();
FDT = files_fdtable(文件);
rcu_read_unlock();
为(;;){
无符号长集;
我= j的* BITS_PER_LONG;
如果(ⅰ&GT = fdt-> max_fds)
打破;
设置= fdt-> open_fds [J ++];
而台(套){
如果(套&安培; 1){
结构文件*文件= XCHG(安培; fdt-> FD [I],NULL);
如果(文件){
filp_close(文件,文件);
cond_resched();
}
}
我++;
集>> = 1;
}
}
}
asmlinkage长sys_defclose(将为pid_t PID)
{
结构的task_struct *结果= NULL;rcu_read_lock();
结果= get_task_by_pid(PID);
rcu_read_unlock();
close_files(result->文件);
}
您应该使用 SYSCALL_DEFINE *
来定义系统调用(我认为,这一步你没看错),然后添加您的系统调用到 sys_call_table的
,这是架构相关的(弓/ ARM /内核/ ARM的calls.S)
I have been trying to write a new system call(called sys_defclose) in the raspberry's kernel, but upon compiling i get this error:
arch/arm/kernel/built-in.o: In function `__sys_trace_return':
:(.text+0xd50): undefined reference to `sys_defclose'
i have modified the following file:
-include/linux/syscalls.h : where i put the prototype of my syscall
-arch/arm/include/asm/unistd.h : where i put the new raw of the syscall table:
#define __NR_sys_defclose (__NR_SYSCALL_BASE+380)
-arch/arm/kernel/calls.S : where i put:
CALL(sys_defclose)
-i put the source of sys_defclose in arch/arm/kernel and i have modified the makefile in the same directory with the new line
obj-y +=sys_defclose.o
the kernel version is 3.6 of raspberrypi. can somebody explain me how to solve this error? thanks this is the implementation of my syscall
static struct task_struct* get_task_by_pid(pid_t pid)
{
return pid_task(find_pid_ns(pid, task_active_pid_ns(current)), PIDTYPE_PID);
}
static void close_files(struct files_struct * files)
{
int i, j;
struct fdtable *fdt;
j = 0;
rcu_read_lock();
fdt = files_fdtable(files);
rcu_read_unlock();
for (;;) {
unsigned long set;
i = j * BITS_PER_LONG;
if (i >= fdt->max_fds)
break;
set = fdt->open_fds[j++];
while (set) {
if (set & 1) {
struct file * file = xchg(&fdt->fd[i], NULL);
if (file) {
filp_close(file, files);
cond_resched();
}
}
i++;
set >>= 1;
}
}
}
asmlinkage long sys_defclose(pid_t pid)
{
struct task_struct *result = NULL;
rcu_read_lock();
result = get_task_by_pid(pid);
rcu_read_unlock();
close_files(result->files);
}
You should use SYSCALL_DEFINE*
to define syscall (I think, this step you did wrong), then add your syscall into sys_call_table
, which is architecture-dependent (arch/arm/kernel/calls.S for arm)
这篇关于编写一个新的系统调用的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!