Module Name: src
Committed By: jruoho
Date: Mon May 3 06:11:38 UTC 2010
Modified Files:
src/lib/libc/stdlib: alloca.3
Log Message:
Note the problems with SSP.
To generate a diff of this commit:
cvs rdiff -u -r1.12 -r1.13 src/lib/libc/stdlib/alloca.3
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/lib/libc/stdlib/alloca.3
diff -u src/lib/libc/stdlib/alloca.3:1.12 src/lib/libc/stdlib/alloca.3:1.13
--- src/lib/libc/stdlib/alloca.3:1.12 Thu Aug 7 16:43:37 2003
+++ src/lib/libc/stdlib/alloca.3 Mon May 3 06:11:38 2010
@@ -1,4 +1,4 @@
-.\" $NetBSD: alloca.3,v 1.12 2003/08/07 16:43:37 agc Exp $
+.\" $NetBSD: alloca.3,v 1.13 2010/05/03 06:11:38 jruoho Exp $
.\"
.\" Copyright (c) 1980, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
@@ -29,7 +29,7 @@
.\"
.\" from: @(#)alloca.3 8.1 (Berkeley) 6/4/93
.\"
-.Dd August 11, 2002
+.Dd May 3, 2010
.Dt ALLOCA 3
.Os
.Sh NAME
@@ -63,12 +63,15 @@
.Xr getpagesize 3 ,
.Xr malloc 3 ,
.Xr realloc 3
-.Sh BUGS
+.Sh CAVEATS
+Few limitations can be mentioned:
+.Bl -bullet
+.It
The
.Fn alloca
function
is machine dependent; its use is discouraged.
-.Pp
+.It
The
.Fn alloca
function is slightly unsafe because it cannot ensure that the pointer
@@ -80,6 +83,15 @@
Avoid
.Fn alloca
with large unbounded allocations.
+.It
+Since
+.Fn alloca
+modifies the stack at runtime,
+it causes problems to certain security features.
+See
+.Xr security 8
+for a discussion.
+.El
.\" .Sh HISTORY
.\" The
.\" .Fn alloca
