1 files changed, 21 insertions, 24 deletions
diff --git a/src/lib/libc/stdlib/alloca.3 b/src/lib/libc/stdlib/alloca.3
index dcb97ab11c..8cc5c42ff5 100644
--- a/src/lib/libc/stdlib/alloca.3
+++ b/src/lib/libc/stdlib/alloca.3
@@ -9,11 +9,7 @@
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
-.\" 3. All advertising materials mentioning features or use of this software
+.\" 3. Neither the name of the University nor the names of its contributors
-.\"    must display the following acknowledgement:
-.\"     This product includes software developed by the University of
-.\"     California, Berkeley and its contributors.
-.\" 4. Neither the name of the University nor the names of its contributors
 .\"    may be used to endorse or promote products derived from this software
 .\"    without specific prior written permission.
 .\"
@@ -29,12 +25,11 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"     from: @(#)alloca.3      5.1 (Berkeley) 5/2/91
+.\"     $OpenBSD: alloca.3,v 1.12 2012/04/12 15:46:57 deraadt Exp $
-.\"     $Id: alloca.3,v 1.1.1.1 1995/10/18 08:42:16 deraadt Exp $
 .\"
-.Dd May 2, 1991
+.Dd $Mdocdate: April 12 2012 $
 .Dt ALLOCA 3
-.Os BSD 4
+.Os
 .Sh NAME
 .Nm alloca
 .Nd memory allocator
@@ -45,35 +40,37 @@
 .Sh DESCRIPTION
 The
 .Fn alloca
-function
+function allocates
-allocates 
 .Fa size
 bytes of space in the stack frame of the caller.
-This temporary space is automatically freed on
+This temporary space is automatically freed on return.
-return.
 .Sh RETURN VALUES
 The
 .Fn alloca
 function returns a pointer to the beginning of the allocated space.
-If the allocation failed, a
-.Dv NULL
-pointer is returned.
 .Sh SEE ALSO
+.Xr pagesize 1 ,
 .Xr brk 2 ,
-.Xr pagesize 2
 .Xr calloc 3 ,
 .Xr malloc 3 ,
-.Xr realloc 3 ,
+.Xr realloc 3
-.Sh BUGS
-The
-.Fn alloca
-function
-is machine dependent; its use is discouraged.
 .\" .Sh HISTORY
 .\" The
 .\" .Fn alloca
 .\" function appeared in
 .\" .Bx ?? .
-.\" The function appeared in 32v, pwb and pwb.2 and in 3bsd 4bsd 
+.\" The function appeared in 32v, pwb and pwb.2 and in 3bsd 4bsd
 .\" The first man page (or link to a man page that I can find at the
 .\" moment is 4.3...
+.Sh BUGS
+The
+.Fn alloca
+function is slightly unsafe because it cannot ensure that the pointer
+returned points to a valid and usable block of memory.
+The allocation made may exceed the bounds of the stack, or even go
+further into other objects in memory, and
+.Fn alloca
+cannot determine such an error.
+Avoid
+.Fn alloca
+with large unbounded allocations.

diff --git a/src/lib/libc/stdlib/alloca.3 b/src/lib/libc/stdlib/alloca.3 index dcb97ab11c..8cc5c42ff5 100644 --- a/src/lib/libc/stdlib/alloca.3 +++ b/src/lib/libc/stdlib/alloca.3
@@ -9,11 +9,7 @@
9	.\" 2. Redistributions in binary form must reproduce the above copyright	9	.\" 2. Redistributions in binary form must reproduce the above copyright
10	.\" notice, this list of conditions and the following disclaimer in the	10	.\" notice, this list of conditions and the following disclaimer in the
11	.\" documentation and/or other materials provided with the distribution.	11	.\" documentation and/or other materials provided with the distribution.
12	.\" 3. All advertising materials mentioning features or use of this software	12	.\" 3. Neither the name of the University nor the names of its contributors
13	.\" must display the following acknowledgement:
14	.\" This product includes software developed by the University of
15	.\" California, Berkeley and its contributors.
16	.\" 4. Neither the name of the University nor the names of its contributors
17	.\" may be used to endorse or promote products derived from this software	13	.\" may be used to endorse or promote products derived from this software
18	.\" without specific prior written permission.	14	.\" without specific prior written permission.
19	.\"	15	.\"
@@ -29,12 +25,11 @@
29	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF	25	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30	.\" SUCH DAMAGE.	26	.\" SUCH DAMAGE.
31	.\"	27	.\"
32	.\" from: @(#)alloca.3 5.1 (Berkeley) 5/2/91	28	.\" $OpenBSD: alloca.3,v 1.12 2012/04/12 15:46:57 deraadt Exp $
33	.\" $Id: alloca.3,v 1.1.1.1 1995/10/18 08:42:16 deraadt Exp $
34	.\"	29	.\"
35	.Dd May 2, 1991	30	.Dd $Mdocdate: April 12 2012 $
36	.Dt ALLOCA 3	31	.Dt ALLOCA 3
37	.Os BSD 4	32	.Os
38	.Sh NAME	33	.Sh NAME
39	.Nm alloca	34	.Nm alloca
40	.Nd memory allocator	35	.Nd memory allocator
@@ -45,35 +40,37 @@
45	.Sh DESCRIPTION	40	.Sh DESCRIPTION
46	The	41	The
47	.Fn alloca	42	.Fn alloca
48	function	43	function allocates
49	allocates
50	.Fa size	44	.Fa size
51	bytes of space in the stack frame of the caller.	45	bytes of space in the stack frame of the caller.
52	This temporary space is automatically freed on	46	This temporary space is automatically freed on return.
53	return.
54	.Sh RETURN VALUES	47	.Sh RETURN VALUES
55	The	48	The
56	.Fn alloca	49	.Fn alloca
57	function returns a pointer to the beginning of the allocated space.	50	function returns a pointer to the beginning of the allocated space.
58	If the allocation failed, a
59	.Dv NULL
60	pointer is returned.
61	.Sh SEE ALSO	51	.Sh SEE ALSO
		52	.Xr pagesize 1 ,
62	.Xr brk 2 ,	53	.Xr brk 2 ,
63	.Xr pagesize 2
64	.Xr calloc 3 ,	54	.Xr calloc 3 ,
65	.Xr malloc 3 ,	55	.Xr malloc 3 ,
66	.Xr realloc 3 ,	56	.Xr realloc 3
67	.Sh BUGS
68	The
69	.Fn alloca
70	function
71	is machine dependent; its use is discouraged.
72	.\" .Sh HISTORY	57	.\" .Sh HISTORY
73	.\" The	58	.\" The
74	.\" .Fn alloca	59	.\" .Fn alloca
75	.\" function appeared in	60	.\" function appeared in
76	.\" .Bx ?? .	61	.\" .Bx ?? .
77	.\" The function appeared in 32v, pwb and pwb.2 and in 3bsd 4bsd	62	.\" The function appeared in 32v, pwb and pwb.2 and in 3bsd 4bsd
78	.\" The first man page (or link to a man page that I can find at the	63	.\" The first man page (or link to a man page that I can find at the
79	.\" moment is 4.3...	64	.\" moment is 4.3...
		65	.Sh BUGS
		66	The
		67	.Fn alloca
		68	function is slightly unsafe because it cannot ensure that the pointer
		69	returned points to a valid and usable block of memory.
		70	The allocation made may exceed the bounds of the stack, or even go
		71	further into other objects in memory, and
		72	.Fn alloca
		73	cannot determine such an error.
		74	Avoid
		75	.Fn alloca
		76	with large unbounded allocations.