Kernel+Userland: Introduce a new way to reboot and poweroff the machine

This change removes the halt and reboot syscalls, and create a new
mechanism to change the power state of the machine.
Instead of how power state was changed until now, put a SysFS node as
writable only for the superuser, that with a defined value, can result
in either reboot or poweroff.
In the future, a power group can be assigned to this node (which will be
the GroupID responsible for power management).

This opens an opportunity to permit to shutdown/reboot without superuser
permissions, so in the future, a userspace daemon can take control of
this node to perform power management operations without superuser
permissions, if we enforce different UserID/GroupID on that node.

1 files changed, 0 insertions, 2 deletions

diff --git a/Userland/Libraries/LibC/unistd.h b/Userland/Libraries/LibC/unistd.h
index 2cdfb4df5c..d738aaa32d 100644
--- a/Userland/Libraries/LibC/unistd.h
+++ b/Userland/Libraries/LibC/unistd.h
@@ -108,8 +108,6 @@ int chown(const char* pathname, uid_t, gid_t);
 int fchown(int fd, uid_t, gid_t);
 int ftruncate(int fd, off_t length);
 int truncate(const char* path, off_t length);
-int halt();
-int reboot();
 int mount(int source_fd, const char* target, const char* fs_type, int flags);
 int umount(const char* mountpoint);
 int pledge(const char* promises, const char* execpromises);