[PATCH] um: Add definition of __NR_close_range for older host OSs

__NR_close_range was introduced with
278a5fbaed89dacd04e9d052f4594ffd0e0585de ("open: add close_range()")
which is present in Linux >= 5.9. Older hosts running a kernel version
prior to that range currently fail to build due to that missing system
call number definition.

Fixes: f82a9e7b9fa9 ("um: fix execve stub execution on old host OSs")
Signed-off-by: Florian Fainelli <[email protected]>
---
 arch/um/include/shared/skas/stub-data.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/um/include/shared/skas/stub-data.h b/arch/um/include/shared/skas/stub-data.h
index 27db38e95df9..1230a325debc 100644
--- a/arch/um/include/shared/skas/stub-data.h
+++ b/arch/um/include/shared/skas/stub-data.h
@@ -9,11 +9,20 @@
 #define __STUB_DATA_H
 
 #include <linux/compiler_types.h>
+#include <asm/unistd.h>
 #include <as-layout.h>
 #include <sysdep/tls.h>
 #include <sysdep/stub-data.h>
 #include <mm_id.h>
 
+#ifndef __NR_close_range
+# if defined(__alpha__)
+#  define __NR_close_range 546
+# else
+#  define __NR_close_range 436
+# endif
+#endif
+
 #define FUTEX_IN_CHILD 0
 #define FUTEX_IN_KERN 1
 
-- 
2.34.1