Libc-763.11.tar.gz

[apple/libc.git] / stdlib / FreeBSD / alloca.3

diff --git a/stdlib/FreeBSD/alloca.3 b/stdlib/FreeBSD/alloca.3
index c5be9fff6614a32a49d33bce91f2c66d41dee269..9866edfb2f0f2290b9a33ed98ea46ea485566846 100644 (file)
--- a/stdlib/FreeBSD/alloca.3
+++ b/stdlib/FreeBSD/alloca.3
@@ -9,10 +9,6 @@
 .\" 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
-.\"    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.
@@ -30,9 +26,9 @@
 .\" SUCH DAMAGE.
 .\"
 .\"     @(#)alloca.3   8.1 (Berkeley) 6/4/93
-.\" $FreeBSD: src/lib/libc/stdlib/alloca.3,v 1.11 2003/06/28 22:12:30 ru Exp $
+.\" $FreeBSD: src/lib/libc/stdlib/alloca.3,v 1.13 2007/01/09 00:28:09 imp Exp $
 .\"
-.Dd June 4, 1993
+.Dd September 5, 2006
 .Dt ALLOCA 3
 .Os
 .Sh NAME
@@ -57,9 +53,6 @@ return.
 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 brk 2 ,
 .Xr calloc 3 ,
@@ -81,3 +74,15 @@ The
 function
 is machine and compiler dependent;
 its use is discouraged.
+.Pp
+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.