1 files changed, 7 insertions, 2 deletions
diff --git a/devel/sysdefs-list b/devel/sysdefs-list
index 61532cf2..ba51de6c 100755
--- a/devel/sysdefs-list
+++ b/devel/sysdefs-list
@@ -2,8 +2,6 @@
  # License: AGPL-3.0+ <http://www.gnu.org/licenses/agpl-3.0.txt>
  # Dump system-specific constant numbers this is to maintain
  # PublicInbox::Syscall and any other system-specific pieces.
-# DO NOT USE syscall numbers for *BSDs, none of the current BSD kernels
-# we know about promise stable syscall numbers (unlike Linux).
  # However, sysconf(3) constants are stable ABI on all safe to dump.
  eval 'exec perl -S $0 ${1+"$@"}' # no shebang
          if 0; # running under some shell
@@ -179,5 +177,12 @@ int main(void)
                  PR_NUM(cmsg_type);
          STRUCT_END;
  
+        {
+                struct cmsghdr cmsg;
+                uintptr_t cmsg_data_off;
+                cmsg_data_off = (uintptr_t)CMSG_DATA(&cmsg) - (uintptr_t)&cmsg;
+                D(cmsg_data_off);
+        }
+
          return 0;
  }