user: implement mlibc as the libc, finally.

It's finally done..

Signed-off-by: kaguya <vpshinomiya@protonmail.com>

user/include/mlibc/options/linux/generic/sys-ptrace.cpp

@@ -0,0 +1,36 @@
+
+#include <sys/ptrace.h>
+#include <stdarg.h>
+#include <errno.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <mlibc/linux-sysdeps.hpp>
+
+long ptrace(int req, ...) {
+	va_list ap;
+
+	va_start(ap, req);
+	auto pid = va_arg(ap, pid_t);
+	auto addr = va_arg(ap, void *);
+	auto data = va_arg(ap, void *);
+	va_end(ap);
+
+	long ret;
+	if(req > 0 && req < 4) {
+		data = &ret;
+	}
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_ptrace, -1);
+	long out;
+	if(int e = mlibc::sys_ptrace(req, pid, addr, data, &out); e) {
+		errno = e;
+		return -1;
+	} else if(req > 0 && req < 4) {
+		errno = 0;
+		return ret;
+	}
+
+	return out;
+}
+