tequilaOS/platform_bionic
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

FORTIFY_SOURCE: add snprintf, vsnprintf

Browse source 
Add _FORTIFY_SOURCE support for snprintf, vsnprintf

At this time, we opt out of these protections for clang, as clang
does not implement __builtin_va_arg_pack().

http://clang.llvm.org/docs/UsersManual.html#c_unimpl_gcc

Change-Id: I73ebe5ec8dad1dca8898a76d6afb693a25f75375
This commit is contained in:
Nick Kralevich 2012-06-11 15:50:57 -07:00
parent 85b06f9365
commit cffdf6693f
4 changed files with 149 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
libc/Android.mk
View file

@ -140,6 +140,8 @@ libc_common_src_files := \
stdio/vsscanf.c \
stdio/wbuf.c \
stdio/wsetup.c \
stdio/__snprintf_chk.c \
stdio/__vsnprintf_chk.c \
stdlib/_rand48.c \
stdlib/assert.c \
stdlib/atexit.c \

28
libc/include/stdio.h
View file

@ -458,4 +458,32 @@ int vfdprintf(int, const char*, __va_list);
__END_DECLS
#endif /* _GNU_SOURCE */
#if defined(__BIONIC_FORTIFY_INLINE)
__BIONIC_FORTIFY_INLINE
__attribute__((__format__ (printf, 3, 0)))
__attribute__((__nonnull__ (3)))
int vsnprintf(char *str, size_t size, const char *format, __va_list ap)
{
return __builtin___vsnprintf_chk(str, size, 0, __builtin_object_size(str, 0), format, ap);
}
# if !defined(__clang__)
/*
* Clang doesn't have support for __builtin_va_arg_pack()
* http://clang.llvm.org/docs/UsersManual.html#c_unimpl_gcc
*/
__BIONIC_FORTIFY_INLINE
__attribute__((__format__ (printf, 3, 4)))
__attribute__((__nonnull__ (3)))
int snprintf(char *str, size_t size, const char *format, ...)
{
return __builtin___snprintf_chk(str, size, 0, __builtin_object_size(str, 0), format, __builtin_va_arg_pack());
}
# endif /* !defined(__clang__) */
#endif /* defined(__BIONIC_FORTIFY_INLINE) */
#endif /* _STDIO_H_ */

59
libc/stdio/__snprintf_chk.c Normal file
View file

@ -0,0 +1,59 @@
/*
* Copyright (C) 2012 The Android Open Source 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:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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 COPYRIGHT HOLDERS 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
* COPYRIGHT OWNER 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 <stdio.h>
#include <stdarg.h>
/*
* Runtime implementation of __builtin____snprintf_chk.
*
* See
* http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html
* http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html
* for details.
*
* This snprintf check is called if _FORTIFY_SOURCE is defined and
* greater than 0.
*/
int __snprintf_chk(
char *dest,
size_t supplied_size,
int flags,
size_t dest_len_from_compiler,
const char *format, ...)
{
va_list va;
int retval;
va_start(va, format);
retval = __vsnprintf_chk(dest, supplied_size, flags,
dest_len_from_compiler, format, va);
va_end(va);
return retval;
}

60
libc/stdio/__vsnprintf_chk.c Normal file
View file

@ -0,0 +1,60 @@
/*
* Copyright (C) 2012 The Android Open Source 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:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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 COPYRIGHT HOLDERS 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
* COPYRIGHT OWNER 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 <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <private/logd.h>
/*
* Runtime implementation of __builtin____vsnprintf_chk.
*
* See
* http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html
* http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html
* for details.
*
* This vsnprintf check is called if _FORTIFY_SOURCE is defined and
* greater than 0.
*/
int __vsnprintf_chk(
char *dest,
size_t supplied_size,
int flags,
size_t dest_len_from_compiler,
const char *format,
va_list va)
{
if (supplied_size > dest_len_from_compiler) {
__libc_android_log_print(ANDROID_LOG_FATAL, "libc",
"*** vsnprintf buffer overflow detected ***\n");
abort();
}
return vsnprintf(dest, supplied_size, format, va);
}