d/freebsd-nq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

libc: Always use our own copy of sys_errlist and sys_nerr (.so only).

Browse Source 
This ensures strerror() and friends continue to work correctly even if a
(non-PIE) executable linked against an older libc imports sys_errlist (which
causes sys_errlist to refer to the executable's copy with a size fixed when
that executable was linked).

The executable's use of sys_errlist remains broken because it uses the
current value of sys_nerr and may access past the bounds of the array.

Different from the message "Using sys_errlist from executables is not
ABI-stable" on freebsd-arch, this change does not affect the static library.
There seems no reason to prevent overriding the error messages in the static
library.
This commit is contained in:
Jilles Tjoelker 2013-08-31 22:32:42 +00:00
parent e639f25706
commit e73151eb82
4 changed files with 56 additions and 4 deletions
lib/libc
gen
errlst.c
include
errlst.h
stdio
xprintf_errno.c
string
strerror.c

6
lib/libc/gen/errlst.c

@ -34,6 +34,7 @@ static char sccsid[] = "@(#)errlst.c 8.2 (Berkeley) 11/16/93";
__FBSDID("$FreeBSD$");
#include <stdio.h>
#include "errlst.h"
const char *const sys_errlist[] = {
"No error: 0", /* 0 - ENOERROR */
@ -156,3 +157,8 @@ const char *const sys_errlist[] = {
"Previous owner died", /* 96 - EOWNERDEAD */
};
const int sys_nerr = sizeof(sys_errlist) / sizeof(sys_errlist[0]);
#ifdef PIC
__strong_reference(sys_errlist, __hidden_sys_errlist);
__strong_reference(sys_nerr, __hidden_sys_nerr);
#endif

43
lib/libc/include/errlst.h Normal file

@ -0,0 +1,43 @@
/*-
* Copyright (c) 2013 Jilles Tjoelker
* 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.
*
* $FreeBSD$
*/
#ifndef __ERRLST_H__
#define __ERRLST_H__
#include <sys/cdefs.h>
#ifdef PIC
/* If the main executable imports these, do not use its copy from libc.so. */
extern const char *const __hidden_sys_errlist[] __hidden;
extern const int __hidden_sys_nerr __hidden;
#else
#define __hidden_sys_errlist sys_errlist
#define __hidden_sys_nerr sys_nerr
#endif
#endif /* __ERRLST_H__ */

3
lib/libc/stdio/xprintf_errno.c

@ -34,6 +34,7 @@
#include <vis.h>
#include <assert.h>
#include <sys/time.h>
#include "errlst.h"
#include "printf.h"
int
@ -54,7 +55,7 @@ __printf_render_errno(struct __printf_io *io, const struct printf_info *pi __unu
ret = 0;
error = *((const int *)arg[0]);
if (error >= 0 && error < sys_nerr) {
if (error >= 0 && error < __hidden_sys_nerr) {
p = strerror(error);
return (__printf_out(io, pi, p, strlen(p)));
}

8
lib/libc/string/strerror.c

@ -42,6 +42,8 @@ __FBSDID("$FreeBSD$");
#include <string.h>
#include <stdio.h>
#include "errlst.h"
#define UPREFIX "Unknown error"
/*
@ -87,7 +89,7 @@ strerror_r(int errnum, char *strerrbuf, size_t buflen)
catd = catopen("libc", NL_CAT_LOCALE);
#endif
if (errnum < 0 || errnum >= sys_nerr) {
if (errnum < 0 || errnum >= __hidden_sys_nerr) {
errstr(errnum,
#if defined(NLS)
catgets(catd, 1, 0xffff, UPREFIX),
@ -99,9 +101,9 @@ strerror_r(int errnum, char *strerrbuf, size_t buflen)
} else {
if (strlcpy(strerrbuf,
#if defined(NLS)
catgets(catd, 1, errnum, sys_errlist[errnum]),
catgets(catd, 1, errnum, __hidden_sys_errlist[errnum]),
#else
sys_errlist[errnum],
__hidden_sys_errlist[errnum],
#endif
buflen) >= buflen)
retval = ERANGE;