Initial changes for execve() support

tasks/libposix/execve.c

@@ -0,0 +1,66 @@
+/*
+ * l4/posix glue for execve()
+ *
+ * Copyright (C) 2007 Bahadir Balban
+ */
+#include <errno.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
+#include <sys/shm.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <l4lib/arch/syscalls.h>
+#include <l4lib/arch/syslib.h>
+#include <l4lib/ipcdefs.h>
+#include <l4lib/utcb.h>
+#include <fcntl.h>
+#include <l4/macros.h>
+#include INC_GLUE(memory.h)
+
+
+struct sys_execve_args {
+	char *path;
+	char **argv;
+	char **envp;
+};
+
+static inline int l4_execve(const char *pathname, char *const argv[], char *const envp[])
+{
+	int err = 0;
+
+	write_mr(L4SYS_ARG0, (unsigned long)pathname);
+	write_mr(L4SYS_ARG1, (unsigned long)argv);
+	write_mr(L4SYS_ARG2, (unsigned long)envp);
+
+
+	/* Call pager with open() request. Check ipc error. */
+	if ((err = l4_sendrecv(PAGER_TID, PAGER_TID, L4_IPC_TAG_EXECVE)) < 0) {
+		printf("%s: L4 IPC Error: %d.\n", __FUNCTION__, err);
+		return err;
+	}
+	/* Check if syscall itself was successful */
+	if ((err = l4_get_retval()) < 0) {
+		printf("%s: OPEN Error: %d.\n", __FUNCTION__, err);
+		return err;
+	}
+
+	return err;
+}
+
+int execve(const char *pathname, char *const argv[], char *const envp[])
+{
+	int ret;
+
+	ret = l4_execve(pathname, argv, envp);
+
+	/* If error, return positive error code */
+	if (ret < 0) {
+		errno = -ret;
+		return -1;
+	}
+	/* else return value */
+	return ret;
+
+}
+