syscalls: setpriority

kernel-src/sys/syscalls/setpriority.c

@@ -0,0 +1,29 @@
+#include <kernel/syscalls.h>
+#include <kernel/thread.h>
+#include <kernel/auth.h>
+#include <arch/cpu.h>
+
+syscallret_t syscall_setpriority(context_t *, int which, int who, int priority) {
+	syscallret_t ret = {
+		.ret = -1
+	};
+
+	if (which != 0) {
+		ret.errno = EINVAL;
+		return ret;
+	}
+
+	if (who) {
+		ret.errno = ESRCH;
+		return ret;
+	}
+
+	ret.errno = priority < current_thread()->proc->nice ? auth_process_check(&current_thread()->proc->cred, AUTH_ACTIONS_PROCESS_NICE, NULL) : 0;
+	if (ret.errno)
+		return ret;
+
+	current_thread()->proc->nice = max(min(priority, SCHED_NICE_MAX), SCHED_NICE_MIN);
+
+	ret.ret = 0;
+	return ret;
+}