svn commit: r365428 - head/sys/sys

[Brandon Bergren]

Author: bdragon
Date: Mon Sep  7 20:05:18 2020
New Revision: 365428
URL: https://svnweb.freebsd.org/changeset/base/365428

Log:
  Fix vdso compat32 timekeeping on !=x86.
  
  Since x86 is the only 32-bit arch that has a 32-bit time_t, adjust the
  private bintime32 struct in vdso to only use a 32 bit sec on amd64.
  
  This matches the existing behavior in the compat code.
  
  Noticed while implementing vdso timekeeping on powerpc.
  
  This should also theoretically fix vdso timekeeping for arm binaries on
  aarch64.
  
  See tools attached to https://reviews.freebsd.org/D26347 for testing.
  
  Reviewed by:	kib (in irc)
  Sponsored by:	Tag1 Consulting, Inc.

Modified:
  head/sys/sys/vdso.h

Modified: head/sys/sys/vdso.h
==============================================================================
--- head/sys/sys/vdso.h	Mon Sep  7 19:35:30 2020	(r365427)
+++ head/sys/sys/vdso.h	Mon Sep  7 20:05:18 2020	(r365428)
@@ -102,8 +102,16 @@ struct vdso_sv_tk *alloc_sv_tk(void);
 #define	VDSO_TH_NUM	4
 
 #ifdef COMPAT_FREEBSD32
+
+/*
+ * i386 is the only arch with a 32 bit time_t.
+ */
 struct bintime32 {
+#if defined(__amd64__)
 	uint32_t	sec;
+#else
+	uint64_t	sec;
+#endif
 	uint32_t	frac[2];
 };