cuserid: support invocation with a null pointer argument

[musl] / src / unistd / fchown.c

diff --git a/src/unistd/fchown.c b/src/unistd/fchown.c
index e1c3198..737b367 100644 (file)
--- a/src/unistd/fchown.c
+++ b/src/unistd/fchown.c
@@ -1,15 +1,20 @@
 #include <unistd.h>
 #include <errno.h>
+#include <fcntl.h>
 #include "syscall.h"
 
-void __procfdname(char *, unsigned);
-
 int fchown(int fd, uid_t uid, gid_t gid)
 {
        int ret = __syscall(SYS_fchown, fd, uid, gid);
-       if (ret != -EBADF || fd < 0) return __syscall_ret(ret);
+       if (ret != -EBADF || __syscall(SYS_fcntl, fd, F_GETFD) < 0)
+               return __syscall_ret(ret);
 
        char buf[15+3*sizeof(int)];
        __procfdname(buf, fd);
+#ifdef SYS_chown
        return syscall(SYS_chown, buf, uid, gid);
+#else
+       return syscall(SYS_fchownat, AT_FDCWD, buf, uid, gid, 0);
+#endif
+
 }