SYS_SETFSUID

SYS_SETFSUID is a system call in Linux and other Unix-like operating systems. It is used to set the file system user ID (FSUID) of the current process. The FSUID is a special user ID that is used to determine the permissions for accessing files and directories on the file system. This system call is typically used by privileged programs, such as system daemons or security modules, to switch the FSUID of a process to that of another user or group, in order to grant or restrict access to certain files or directories. The syntax of the SYS_SETFSUID system call is:

long sys_setfsuid(uid_t fsuid);

where fsuid is the new FSUID to be set for the current process