Kernel/LibC: Implement pthread_self

kernel/include/kernel/Process.h

@@ -184,6 +184,7 @@ namespace Kernel
 
 		BAN::ErrorOr<long> sys_pthread_create(const pthread_attr_t* __restrict attr, void (*entry)(void*), void* arg);
 		BAN::ErrorOr<long> sys_pthread_exit(void* value);
+		BAN::ErrorOr<long> sys_pthread_self();
 
 		BAN::ErrorOr<long> sys_tcgetpgrp(int fd);
 		BAN::ErrorOr<long> sys_tcsetpgrp(int fd, pid_t pgid);

kernel/kernel/Process.cpp

@@ -2121,6 +2121,11 @@ namespace Kernel
 		ASSERT_NOT_REACHED();
 	}
 
+	BAN::ErrorOr<long> Process::sys_pthread_self()
+	{
+		return Thread::current().tid();
+	}
+
 	BAN::ErrorOr<long> Process::sys_tcgetpgrp(int fd)
 	{
 		LockGuard _(m_process_lock);

userspace/libraries/LibC/include/sys/syscall.h

@@ -92,6 +92,7 @@ __BEGIN_DECLS
 	O(SYS_HARDLINKAT,		hardlinkat)		\
 	O(SYS_PTHREAD_CREATE,	pthread_create)	\
 	O(SYS_PTHREAD_EXIT,		pthread_exit)	\
+	O(SYS_PTHREAD_SELF,		pthread_self)	\
 
 enum Syscall
 {

userspace/libraries/LibC/pthread.cpp

@@ -47,3 +47,8 @@ void pthread_exit(void* value_ptr)
 	syscall(SYS_PTHREAD_EXIT, value_ptr);
 	ASSERT_NOT_REACHED();
 }
+
+pthread_t pthread_self(void)
+{
+	return syscall(SYS_PTHREAD_SELF);
+}