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回复 1# sky__sea
你不用这么麻烦,只要找到这个PID对应的task_struct ,用这个结构中的 fs中找到相对应的代码就可以了。
这里你可以参考 fs/dcache.c中的代码
- /*
- * NOTE! The user-level library version returns a
- * character pointer. The kernel system call just
- * returns the length of the buffer filled (which
- * includes the ending '\0' character), or a negative
- * error value. So libc would do something like
- *
- * char *getcwd(char * buf, size_t size)
- * {
- * int retval;
- *
- * retval = sys_getcwd(buf, size);
- * if (retval >= 0)
- * return buf;
- * errno = -retval;
- * return NULL;
- * }
- */
- SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size)
- {
- int error;
- struct path pwd, root;
- char *page = __getname();
- if (!page)
- return -ENOMEM;
- rcu_read_lock();
- get_fs_root_and_pwd_rcu(current->fs, &root, &pwd);
- error = -ENOENT;
- if (!d_unlinked(pwd.dentry)) {
- unsigned long len;
- char *cwd = page + PATH_MAX;
- int buflen = PATH_MAX;
- prepend(&cwd, &buflen, "\0", 1);
- error = prepend_path(&pwd, &root, &cwd, &buflen);
- rcu_read_unlock();
- if (error < 0)
- goto out;
- /* Unreachable from current root */
- if (error > 0) {
- error = prepend_unreachable(&cwd, &buflen);
- if (error)
- goto out;
- }
- error = -ERANGE;
- len = PATH_MAX + page - cwd;
- if (len <= size) {
- error = len;
- if (copy_to_user(buf, cwd, len))
- error = -EFAULT;
- }
- } else {
- rcu_read_unlock();
- }
- out:
- __putname(page);
- return error;
- }
复制代码 看到其中的current的指针,换成你所得到的task_struct的指针就可以了。
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