svn commit: r282314 - in head: include lib/libc/stdlib

[Sergey Kandaurov]

On 1 May 2015 at 21:32, Baptiste Daroussin <bapt at freebsd.org> wrote:
> Author: bapt
> Date: Fri May  1 18:32:16 2015
> New Revision: 282314
> URL: https://svnweb.freebsd.org/changeset/base/282314
>
> Log:
>   Import reallocarray(3) from OpenBSD
>
>   Add a manpage for it, assign the copyright to the OpenBSD project on it since it
>   is mostly copy/paste from OpenBSD manpage.
>   style(9) fixes
>[..]

> Added: head/lib/libc/stdlib/reallocarray.3
> ==============================================================================
> --- /dev/null   00:00:00 1970   (empty, because file is newly added)
> +++ head/lib/libc/stdlib/reallocarray.3 Fri May  1 18:32:16 2015        (r282314)
> @@ -0,0 +1,136 @@
> +.\" Copyright (c) 2015 OpenBSD
> +.\" All rights reserved.

This copyright notice looks suspicious.

> +.\"
> +.\" This code is derived from software contributed to Berkeley by
> +.\" the American National Standards Committee X3, on Information
> +.\" Processing Systems.
> +.\"
> +.\" Redistribution and use in source and binary forms, with or without
> +.\" modification, are permitted provided that the following conditions
> +.\" are met:
> +.\" 1. Redistributions of source code must retain the above copyright
> +.\"    notice, this list of conditions and the following disclaimer.
> +.\" 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.
> +.\"
> +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
> +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> +.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
> +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
> +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
> +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> +.\" SUCH DAMAGE.
> +.\"
> +.\" $FreeBSD$
> +.\"
> +.Dd May 1, 2015
> +.Dt REALLOCARRAY 3
> +.Os
> +.Sh NAME
> +.Nm reallocarray
> +.Nd memory reallocation function
> +.Sh LIBRARY
> +.Lb libc
> +.Sh SYNOPSIS
> +.In stdlib.h
> +.Ft void *
> +.Fn reallocarray "void *ptr" "size_t nmemb" "size_t size"
> +.Sh DESCRIPTION
> +The
> +.Fn reallocarray
> +except it operates on

This is not parseable.

> +.Fa nmemb
> +members of size
> +.Fa size
> +and checks for integer overflow in the calculation
> +.Fa nmemb
> +*
> +.Fa size .

> +.Sh RETURN VALUES
> +.Fn reallocarray
> +return a pointer to the allocated space; otherwise, a
> +.Dv NULL
> +pointer is returned and
> +.Va errno
> +is set to
> +.Er ENOMEM .
> +.Sh EXAMPLES
> +Consider
> +.Fn reallocarray
> +when there is multiplication in the
> +.Fa size
> +argument of
> +.Fn malloc
> +or
> +.Fn realloc .
> +For example, avoid this common idiom as it may lead to integer overflow:
> +.Bd -literal -offset indent
> +if ((p = malloc(num * size)) == NULL)
> +       err(1, "malloc");
> +.Ed
> +.Pp
> +A drop-in replacement is the
> +.Ox
> +extension
> +.Fn reallocarray :
> +.Bd -literal -offset indent
> +if ((p = reallocarray(NULL, num, size)) == NULL)
> +       err(1, "reallocarray");
> +.Ed
> +.Pp
> +When using
> +.Fn realloc ,
> +be careful to avoid the following idiom:
> +.Bd -literal -offset indent
> +size += 50;
> +if ((p = realloc(p, size)) == NULL)
> +       return (NULL);
> +.Ed
> +.Pp
> +Do not adjust the variable describing how much memory has been allocated
> +until the allocation has been successful.
> +This can cause aberrant program behavior if the incorrect size value is used.
> +In most cases, the above sample will also result in a leak of memory.
> +As stated earlier, a return value of
> +.Dv NULL
> +indicates that the old object still remains allocated.
> +Better code looks like this:
> +.Bd -literal -offset indent
> +newsize = size + 50;
> +if ((newp = realloc(p, newsize)) == NULL) {
> +       free(p);
> +       p = NULL;
> +       size = 0;
> +       return (NULL);
> +}
> +p = newp;
> +size = newsize;
> +.Ed
> +.Pp
> +As with
> +.Fn malloc ,
> +it is important to ensure the new size value will not overflow;
> +i.e. avoid allocations like the following:
> +.Bd -literal -offset indent
> +if ((newp = realloc(p, num * size)) == NULL) {
> +       ...
> +.Ed
> +.Pp
> +Instead, use
> +.Fn reallocarray :
> +.Bd -literal -offset indent
> +if ((newp = reallocarray(p, num, size)) == NULL) {
> +       ...
> +.Ed
> +.Sh SEE ALSO
> +.Xr realloc 3
> +.Sh HISTORY
> +The
> +.Fn reallocf
> +function first appeared in
> +.Ox 5.6 .

This looks unrelative and untrue.

-- 
wbr,
pluknet