内容简介
int lookup_dcookie(u64 cookie, char * buffer, size_t len);
描述
查找的值cookie中的cookie是一个不透明的标识符，唯一地标识一个特定的目录项中指定的目录项的完整路径。给出的缓冲区填入目录项的完整路径。For lookup_dcookie() to return successfully, the kernel must still hold a cookie reference to the directory entry.
注意
lookup_dcookie() is a special-purpose system call, currently used only by the oprofile profiler. It relies on a kernel driver to register cookies for directory entries.The path returned may be suffixed by the string " (deleted)" if the directory entry has been removed.
返回值
On success, lookup_dcookie() returns the length of the path string copied into the buffer. On error, -1 is returned, and errno is set appropriately.错误
| 标签 | 描述 |
|---|---|
| EFAULT | The buffer was not valid. |
| EINVAL | The kernel has no registered cookie/directory entry mappings at the time of lookup, or the cookie does not refer to a valid directory entry. |
| ENAMETOOLONG | |
| The name could not fit in the buffer. | |
| ENOMEM | The kernel could not allocate memory for the temporary buffer holding the path. |
| EPERM | The process does not have the capability CAP_SYS_ADMINrequired to look up cookie values. |
| ERANGE | The buffer was not large enough to hold the path of the directory entry. |
遵循于
lookup_dcookie() is Linux-specific.可用性
Since Linux 2.5.43. The ENAMETOOLONG error return was added in 2.5.70.
