proper error handling for fcntl F_GETOWN on modern kernels

[musl] / src / fcntl / fcntl.c

diff --git a/src/fcntl/fcntl.c b/src/fcntl/fcntl.c
index fa5ad32..fb7806a 100644 (file)
--- a/src/fcntl/fcntl.c
+++ b/src/fcntl/fcntl.c
@@ -1,6 +1,8 @@
+#define _GNU_SOURCE
 #include <fcntl.h>
 #include <unistd.h>
 #include <stdarg.h>
+#include <errno.h>
 #include "syscall.h"
 #include "libc.h"
 
@@ -13,6 +15,12 @@ int fcntl(int fd, int cmd, ...)
        va_end(ap);
        if (cmd == F_SETFL) arg |= O_LARGEFILE;
        if (cmd == F_SETLKW) return syscall_cp(SYS_fcntl, fd, cmd, arg);
-       if (cmd == F_GETOWN) return __syscall(SYS_fcntl, fd, cmd, arg);
+       if (cmd == F_GETOWN) {
+               struct f_owner_ex ex;
+               int ret = __syscall(SYS_fcntl, fd, F_GETOWN_EX, &ex);
+               if (ret == -EINVAL) return __syscall(SYS_fcntl, fd, cmd, arg);
+               if (ret) return __syscall_ret(ret);
+               return ex.type == F_OWNER_PGRP ? -ex.pid : ex.pid;
+       }
        return syscall(SYS_fcntl, fd, cmd, arg);
 }