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Diffstat (limited to 'src/unistd/dup2.c')
-rw-r--r--src/unistd/dup2.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/src/unistd/dup2.c b/src/unistd/dup2.c
index 87a0d445..8f43c6dd 100644
--- a/src/unistd/dup2.c
+++ b/src/unistd/dup2.c
@@ -1,10 +1,20 @@
#include <unistd.h>
#include <errno.h>
+#include <fcntl.h>
#include "syscall.h"
int dup2(int old, int 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);
}