sys_setfsgid [kernel/sys.c]
Sets the group ID that the Linux kernel uses to check for all accesses to the file system. Explicit calls to sys_setfsgid are usually only used by programs such as the Linux NFS server that need to change what group ID is used for file access without a corresponding change in the real and effective group IDs. A change in the normal user IDs for a program such as the NFS server is a security hole that can expose it to unwanted signals. Arguments
eax | 139
ebx | Group ID. Normally, the value of ebx will shadow the value of the effective group ID. In fact, whenever the effective group ID is changed, file system GID will also be changed to the new value of the effective group ID.
Return values This system call always returns previous group ID. Remarks sys_setfsgid will only succeed if the caller is the superuser or if ebx matches either the real group ID, effective group ID, saved set-group-ID, or the current value of file system GID. Compatibility n/a