lookup_dcookie()函數 Unix/Linux
內容簡介
int lookup_dcookie(u64 cookie, char * buffer, size_t len);
描述
查找的值cookie中的cookie是一個不透明的標識符，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
| 標簽 | 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. |
