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author | Jilles Tjoelker <jilles@FreeBSD.org> | 2013-08-31 22:32:42 +0000 |
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committer | Jilles Tjoelker <jilles@FreeBSD.org> | 2013-08-31 22:32:42 +0000 |
commit | e73151eb827122b6da662018d051ba8f58ef7e82 (patch) | |
tree | f73c21f9b8d1e27c2aa3ff9c34ace0b9a837e4e0 /lib/libc | |
parent | e639f2570602ce452ae8a30cd634dc6a23bff1f1 (diff) | |
download | src-e73151eb827122b6da662018d051ba8f58ef7e82.tar.gz src-e73151eb827122b6da662018d051ba8f58ef7e82.zip |
libc: Always use our own copy of sys_errlist and sys_nerr (.so only).
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.
Notes
Notes:
svn path=/head/; revision=255108
Diffstat (limited to 'lib/libc')
-rw-r--r-- | lib/libc/gen/errlst.c | 6 | ||||
-rw-r--r-- | lib/libc/include/errlst.h | 43 | ||||
-rw-r--r-- | lib/libc/stdio/xprintf_errno.c | 3 | ||||
-rw-r--r-- | lib/libc/string/strerror.c | 8 |
4 files changed, 56 insertions, 4 deletions
diff --git a/lib/libc/gen/errlst.c b/lib/libc/gen/errlst.c index 7b4fd62a71bb..f8fe9684a26a 100644 --- a/lib/libc/gen/errlst.c +++ b/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 diff --git a/lib/libc/include/errlst.h b/lib/libc/include/errlst.h new file mode 100644 index 000000000000..4e9e29fc3345 --- /dev/null +++ b/lib/libc/include/errlst.h @@ -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__ */ diff --git a/lib/libc/stdio/xprintf_errno.c b/lib/libc/stdio/xprintf_errno.c index 0c2be46a6d70..3c831d129388 100644 --- a/lib/libc/stdio/xprintf_errno.c +++ b/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))); } diff --git a/lib/libc/string/strerror.c b/lib/libc/string/strerror.c index e11b351d7feb..1d7a385bd9ea 100644 --- a/lib/libc/string/strerror.c +++ b/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; |