freebsd-nq/lib/libc/iconv/citrus_mmap.c
Jilles Tjoelker 571d9493ad libc/iconv: Fix race condition with setting FD_CLOEXEC.
A fork/exec could happen between open and fcntl, leaking a file descriptor.
Using O_CLOEXEC fixes this and as a side effect simplifies the code.

NetBSD already had this (I checked this after making the change myself).

Reviewed by:	gabor
2012-12-17 10:38:51 +00:00

94 lines
2.5 KiB
C

/* $FreeBSD$ */
/* $NetBSD: citrus_mmap.c,v 1.3 2005/01/19 00:52:37 mycroft Exp $ */
/*-
* Copyright (c)2003 Citrus Project,
* All rights reserved.
*
* 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 AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "citrus_namespace.h"
#include "citrus_region.h"
#include "citrus_mmap.h"
int
_citrus_map_file(struct _citrus_region * __restrict r,
const char * __restrict path)
{
struct stat st;
void *head;
int fd, ret;
ret = 0;
_region_init(r, NULL, 0);
if ((fd = open(path, O_RDONLY | O_CLOEXEC)) == -1)
return (errno);
if (fstat(fd, &st) == -1) {
ret = errno;
goto error;
}
if (!S_ISREG(st.st_mode)) {
ret = EOPNOTSUPP;
goto error;
}
head = mmap(NULL, (size_t)st.st_size, PROT_READ, MAP_FILE|MAP_PRIVATE,
fd, (off_t)0);
if (head == MAP_FAILED) {
ret = errno;
goto error;
}
_region_init(r, head, (size_t)st.st_size);
error:
(void)close(fd);
return (ret);
}
void
_citrus_unmap_file(struct _citrus_region *r)
{
if (_region_head(r) != NULL) {
(void)munmap(_region_head(r), _region_size(r));
_region_init(r, NULL, 0);
}
}