內容簡介

int lookup_dcookie(u64 cookie, char * buffer, size_t len);

描述

查詢的值cookie中的cookie是一個不透明的識別符號，唯一地標識一個特定的目錄項中指定的目錄項的完整路徑。給出的緩衝區填入目錄項的完整路徑。

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.

錯誤

標籤	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.

遵循於

lookup_dcookie() is Linux-specific.

可用性

Since Linux 2.5.43. The ENAMETOOLONG error return was added in 2.5.70.