#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
#include "syscall.h"
int dup2(int old, int new)
{
- return __syscall_dup2(old, new);
+ int r;
+#ifdef SYS_dup2
+ while ((r=__syscall(SYS_dup2, old, new))==-EBUSY);
+#else
+ if (old==new) {
+ r = __syscall(SYS_fcntl, old, F_GETFD);
+ if (r >= 0) return old;
+ } else {
+ while ((r=__syscall(SYS_dup3, old, new, 0))==-EBUSY);
+ }
+#endif
+ return __syscall_ret(r);
}