Re: bin/58678: ntpd crashes on sparc64

["Martin Husemann via gnats" <gnats-admin%NetBSD.org@localhost>]

The following reply was made to PR bin/58678; it has been noted by GNATS.

From: Martin Husemann <martin%duskware.de@localhost>
To: Christos Zoulas <christos%zoulas.com@localhost>
Cc: gnats-bugs%netbsd.org@localhost
Subject: Re: bin/58678: ntpd crashes on sparc64
Date: Thu, 19 Sep 2024 13:48:37 +0200

 The problem is (manual) over-optimization:
 
 (gdb) p sizeof(res_addr6)
 $1 = 32
 (gdb) p sizeof(res_addr4)
 $2 = 8
 (gdb) p sizeof(restrict_u)
 $3 = 64
 
 So shaving 24 bytes off for each IPv4-only use of restrict_u makes the
 following entries mis-aligned.
 
 An easy fix (suggested by mlelstv) is:
 
 #define V6_SIZEOF_RESTRICT_U sizeof(stuct restrict_u_tag)
 #define V4_SIZEOF_RESTRICT_U V6_SIZEOF_RESTRICT_U
 
 that is: always use the full allocation. This could be restricted to
 alignment-critical architectures. Plus the rearanging to avoid internal
 padding as I suggested before to save 4 bytes per struct on those
 architectures.
 
 Martin