implement as system call so the kernel can provide atomicity and assign the right numbers

1 files changed, 3 insertions, 16 deletions

diff --git a/src/unistd/dup2.c b/src/unistd/dup2.c
index 2755fbc7..ba709a3c 100644
--- a/src/unistd/dup2.c
+++ b/src/unistd/dup2.c
@@ -4,26 +4,13 @@
 #include "fcntl.h"
 #include "limits.h"
 #include "errno.h"
+#include "_syscall.h"
 
 int dup2(int fildes, int fildes2)
 {
-	if (fildes2 < 0 || fildes2 >= _POSIX_OPEN_MAX) {
-		errno = EBADF;
-		return -1;
-	}
-
-	if (fildes == fildes2) {
-		return fildes2;
-	}
-
-	if (fcntl(fildes, F_GETFD) == -1) {
-		errno = EBADF;
-		return -1;
-	}
-
-	close(fildes2);
-	return fcntl(fildes, F_DUPFD, fildes2);
+	SYSCALL(dup2, int, -1, fildes, fildes2, 0, 0, 0, 0);
 }
+
 /*
 POSIX(1)
 */