print syscall: add pid and tid

kernel-src/sys/syscalls/print.c

@@ -2,24 +2,40 @@
 #include <printf.h>
 #include <arch/e9.h>
 #include <mutex.h>
+#include <util.h>
+#include <arch/cpu.h>
 
 syscallret_t syscall_print(context_t *context, char *message) {
 	syscallret_t ret = {
-		.ret = 0,
-		.errno = 0
+		.ret = -1
 	};
 
-	static mutex_t mutex;
-	static bool initialized = false;
+	static MUTEX_DEFINE(mutex);
 
-	if (initialized == false) {
-		MUTEX_INIT(&mutex);
-		initialized = true;
-	}
+	size_t len;
+	ret.errno = usercopy_strlen(message, &len);
+	if (ret.errno)
+		return ret;
+
+	len = min(len, 1023);
+
+	char msg[1024];
+	ret.errno = usercopy_fromuser(msg, message, len);
+	if (ret.errno)
+		return ret;
+
+	msg[len] = '\0';
+
+	char prefix[100];
+	snprintf(prefix, 100, "pid %d tid %d: ", current_thread()->proc->pid, current_thread()->tid);
 
 	MUTEX_ACQUIRE(&mutex);
-	arch_e9_puts(message);
+	arch_e9_puts(prefix);
+	arch_e9_puts(msg);
 	arch_e9_putc('\n');
 	MUTEX_RELEASE(&mutex);
+
+	ret.errno = 0;
+	ret.ret = 0;
 	return ret;
 }