Subject: [PATCH] system: vm: Use 2^32 - 1 as hash size.

From: Mathieu Othacehe <[email-masked]>
Date: Fri, 3 Nov 2017 13:49:04 +0100

* gnu/system/vm.scm (operating-system-uuid): Use 2^32 - 1 instead of
  2^32 as hash size.

On some 32 bit system (ARM for example), 2^32 exceeds hash max
size (ULONG_MAX = 2^32 - 1).
---
 gnu/system/vm.scm | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/gnu/system/vm.scm b/gnu/system/vm.scm
index 3127b30..4424608 100644
--- a/gnu/system/vm.scm
+++ b/gnu/system/vm.scm
@@ -372,13 +372,13 @@ TYPE (one of 'iso9660 or 'dce).  Return a UUID object."
       (bytevector->uuid
        (uint-list->bytevector
         (list (hash file-system-type
-                    (expt 2 32))
+                    (- (expt 2 32) 1))
               (hash (operating-system-host-name os)
-                    (expt 2 32))
+                    (- (expt 2 32) 1))
               (hash (operating-system-services os)
-                    (expt 2 32))
+                    (- (expt 2 32) 1))
               (hash (operating-system-file-systems os)
-                    (expt 2 32)))
+                    (- (expt 2 32) 1)))
         (endianness little)
         4)
        type)))
-- 
2.7.4