svn commit: r314446 - stable/10/contrib/tzcode/stdtime

Ed Maste emaste at FreeBSD.org
Wed Mar 1 01:44:41 UTC 2017


Author: emaste
Date: Wed Mar  1 01:44:40 2017
New Revision: 314446
URL: https://svnweb.freebsd.org/changeset/base/314446

Log:
  MFC r313774:    localtime: return NULL if time_t out of range of struct tm
  
  Previously we would truncate tm.tm_year for any time_t corresponding to
  a year that does not fit in int.  This issue was discovered because it
  caused the bash-static build to fail when linking with LLD.
  
  As reported by Rafael Espíndola:
  
      Configure has
  
      AC_FUNC_MKTIME
  
      which expands to a test of mktime that fails with the freebsd
      implementation. Given that, bash compiles a mktime.o file that
      defines just mktime and uses localtime. That goes in a .a file
      that is before libc.
  
      The freebsd libc defines mktime in localtime.o, which also defines
      localtime among other functions.
  
      When lld sees an undefined reference to mktime from libc, it uses
      the bash provided one and then tries to find a definition of
      localtime. It is found on libc's localtime.o, but now we have a
      duplicated error.
  
      The reason it works with bfd is that bash doesn't use mktime
      directly and the undefined reference from libc is resolved to the
      libc implementation. It would also fail to link if bash itself
      directly used mktime.
  
  The bash-static configure test verifies that, for many values of t, either
  localtime(t) returns NULL or mktime(localtime(t)) == t.  This test failed
  when localtime returned a truncated tm_year.
  
  This was fixed in tzcode in 2004 but has persisted in our tree since
  rS2708.
  
  Sponsored by:	The FreeBSD Foundation

Modified:
  stable/10/contrib/tzcode/stdtime/localtime.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/contrib/tzcode/stdtime/localtime.c
==============================================================================
--- stable/10/contrib/tzcode/stdtime/localtime.c	Wed Mar  1 01:19:41 2017	(r314445)
+++ stable/10/contrib/tzcode/stdtime/localtime.c	Wed Mar  1 01:44:40 2017	(r314446)
@@ -1460,14 +1460,13 @@ const time_t * const	timep;
 		}
 		_RWLOCK_RDLOCK(&lcl_rwlock);
 		tzset_basic(1);
-		localsub(timep, 0L, p_tm);
+		p_tm = localsub(timep, 0L, p_tm);
 		_RWLOCK_UNLOCK(&lcl_rwlock);
-		return(p_tm);
 	} else {
 		tzset_basic(0);
-		localsub(timep, 0L, &tm);
-		return(&tm);
+		p_tm = localsub(timep, 0L, &tm);
 	}
+	return(p_tm);
 }
 
 /*
@@ -1481,7 +1480,7 @@ struct tm *		tmp;
 {
 	_RWLOCK_RDLOCK(&lcl_rwlock);
 	tzset_basic(1);
-	localsub(timep, 0L, tmp);
+	tmp = localsub(timep, 0L, tmp);
 	_RWLOCK_UNLOCK(&lcl_rwlock);
 	return tmp;
 }


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