系统调用函数“sys_getpid”在linux内核的什么位置？

Question

我正在内核中搜索“getpid”函数，但是我找不到实际的函数。

应该是这样的：

asmlinkage long sys_getpid(void)
{
return current-> tgetid;
}

我能找到的只是系统调用表，而不是这个系统调用的实际实现。

内核版本为：3.0.20

提前致谢。

Answer 1

实际定义在kernel/timer.c:

/**
 * sys_getpid - return the thread group id of the current process
 *
 * Note, despite the name, this returns the tgid not the pid.  The tgid and
 * the pid are identical unless CLONE_THREAD was specified on clone() in
 * which case the tgid is the same in all threads of the same group.
 *
 * This is SMP safe as current->tgid does not change.
 */
SYSCALL_DEFINE0(getpid)
{
    return task_tgid_vnr(current);
}

task_tgid_vnr 是include/linux/sched.h 中的静态内联。