svn commit: r277862 - head/lib/libc/gen

[Jilles Tjoelker]

Author: jilles
Date: Wed Jan 28 22:42:56 2015
New Revision: 277862
URL: https://svnweb.freebsd.org/changeset/base/277862

Log:
  sem_post(): Fix and document semaphore value overflow error.
  
  The error code is per Austin Group issue #315.
  
  I provided different wording for the manual page change.
  
  Submitted by:	pluknet
  MFC after:	1 week

Modified:
  head/lib/libc/gen/sem_new.c
  head/lib/libc/gen/sem_post.3

Modified: head/lib/libc/gen/sem_new.c
==============================================================================
--- head/lib/libc/gen/sem_new.c	Wed Jan 28 22:32:03 2015	(r277861)
+++ head/lib/libc/gen/sem_new.c	Wed Jan 28 22:42:56 2015	(r277862)
@@ -439,8 +439,10 @@ _sem_post(sem_t *sem)
 
 	do {
 		count = sem->_kern._count;
-		if (USEM_COUNT(count) + 1 > SEM_VALUE_MAX)
-			return (EOVERFLOW);
+		if (USEM_COUNT(count) + 1 > SEM_VALUE_MAX) {
+			errno = EOVERFLOW;
+			return (-1);
+		}
 	} while (!atomic_cmpset_rel_int(&sem->_kern._count, count, count + 1));
 	if (count & USEM_HAS_WAITERS)
 		usem_wake(&sem->_kern);

Modified: head/lib/libc/gen/sem_post.3
==============================================================================
--- head/lib/libc/gen/sem_post.3	Wed Jan 28 22:32:03 2015	(r277861)
+++ head/lib/libc/gen/sem_post.3	Wed Jan 28 22:42:56 2015	(r277862)
@@ -27,7 +27,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd February 15, 2000
+.Dd January 28, 2015
 .Dt SEM_POST 3
 .Os
 .Sh NAME
@@ -65,6 +65,9 @@ The
 .Fa sem
 argument
 points to an invalid semaphore.
+.It Bq Er EOVERFLOW
+The semaphore value would exceed
+.Dv SEM_VALUE_MAX .
 .El
 .Sh SEE ALSO
 .Xr sem_getvalue 3 ,