Add mutex syscalls

kernel/proc/resource.c

@@ -43,11 +43,11 @@ void proc_cleanup_resources (struct proc* proc) {
 void proc_drop_resource (struct proc* proc, struct proc_resource* resource, bool lock) {
   spin_lock_ctx_t ctxrs;
 
-  DEBUG ("resource=%p created_by=%d vis=%d type=%d rid=%d refs=%d\n", resource,
-         resource->created_by_pid, resource->visibility, resource->type, resource->rid,
-         atomic_load (&resource->refs));
-
   if (atomic_fetch_sub (&resource->refs, 1) == 1) {
+    DEBUG ("resource=%p created_by=%d vis=%d type=%d rid=%d refs=%d\n", resource,
+           resource->created_by_pid, resource->visibility, resource->type, resource->rid,
+           atomic_load (&resource->refs));
+
     switch (resource->visibility) {
     case RV_PRIVATE: {
       if (lock)

kernel/syscall/syscall.c

@@ -177,12 +177,84 @@ DEFINE_SYSCALL (sys_clone) {
   return pid;
 }
 
-/* int proc_sched (void) */
+/* int sched (void) */
 DEFINE_SYSCALL (sys_sched) {
   proc_sched (regs);
   return ST_OK;
 }
 
+/* int create_mutex (int mutex_rid, int vis) */
+DEFINE_SYSCALL (sys_create_mutex) {
+  int mutex_rid = (int)a1;
+  int vis = (int)a2;
+
+  if (mutex_rid < 0)
+    return -ST_BAD_RESOURCE;
+
+  if (!(vis == RV_PUBLIC || vis == RV_PRIVATE))
+    return -ST_BAD_RESOURCE;
+
+  struct proc_resource* mutex_resource =
+      proc_create_resource (proc, mutex_rid, PR_MUTEX, vis, NULL);
+
+  if (mutex_resource == NULL)
+    return -ST_OOM_ERROR;
+
+  return mutex_resource->rid;
+}
+
+/* int unlink_mutex (int mutex_rid, int vis) */
+DEFINE_SYSCALL (sys_unlink_mutex) {
+  int mutex_rid = (int)a1;
+  int vis = (int)a2;
+
+  if (!(vis == RV_PUBLIC || vis == RV_PRIVATE))
+    return -ST_BAD_RESOURCE;
+
+  struct proc_resource* mutex_resource = proc_find_resource (proc, mutex_rid, vis);
+
+  if (mutex_resource == NULL)
+    return -ST_NOT_FOUND;
+
+  proc_drop_resource (proc, mutex_resource, true);
+
+  return ST_OK;
+}
+
+/* int lock_mutex (int mutex_rid, int vis) */
+DEFINE_SYSCALL (sys_lock_mutex) {
+  int mutex_rid = (int)a1;
+  int vis = (int)a2;
+
+  if (!(vis == RV_PUBLIC || vis == RV_PRIVATE))
+    return -ST_BAD_RESOURCE;
+
+  struct proc_resource* mutex_resource = proc_find_resource (proc, mutex_rid, vis);
+
+  if (mutex_resource == NULL)
+    return -ST_NOT_FOUND;
+
+  proc_mutex_lock (proc, &mutex_resource->u.mutex);
+
+  return ST_OK;
+}
+
+/* int unlock_mutex (int mutex_rid, int vis) */
+DEFINE_SYSCALL (sys_unlock_mutex) {
+  int mutex_rid = (int)a1;
+  int vis = (int)a2;
+
+  if (!(vis == RV_PUBLIC || vis == RV_PRIVATE))
+    return -ST_BAD_RESOURCE;
+
+  struct proc_resource* mutex_resource = proc_find_resource (proc, mutex_rid, vis);
+
+  if (mutex_resource == NULL)
+    return -ST_NOT_FOUND;
+
+  return proc_mutex_unlock (proc, &mutex_resource->u.mutex) ? ST_OK : -ST_PERMISSION_ERROR;
+}
+
 static syscall_handler_func_t handler_table[] = {
     [SYS_QUIT] = &sys_quit,
     [SYS_TEST] = &sys_test,
@@ -192,6 +264,10 @@ static syscall_handler_func_t handler_table[] = {
     [SYS_SCHED] = &sys_sched,
     [SYS_CREATE_MEM] = &sys_create_mem,
     [SYS_UNLINK_MEM] = &sys_unlink_mem,
+    [SYS_CREATE_MUTEX] = &sys_create_mutex,
+    [SYS_UNLINK_MUTEX] = &sys_unlink_mutex,
+    [SYS_LOCK_MUTEX] = &sys_lock_mutex,
+    [SYS_UNLOCK_MUTEX] = &sys_unlock_mutex,
 };
 
 syscall_handler_func_t syscall_find_handler (int syscall_num) {