| dnl |
| dnl Useful macros for autoconf to check for ssp-patched gcc |
| dnl 1.0 - September 2003 - Tiago Sousa <mirage@kaotik.org> |
| dnl 1.1 - August 2006 - Ted Percival <ted@midg3t.net> |
| dnl * Stricter language checking (C or C++) |
| dnl * Adds GCC_STACK_PROTECT_LIB to add -lssp to LDFLAGS as necessary |
| dnl * Caches all results |
| dnl * Uses macros to ensure correct ouput in quiet/silent mode |
| dnl 1.2 - April 2007 - Ted Percival <ted@midg3t.net> |
| dnl * Added GCC_STACK_PROTECTOR macro for simpler (one-line) invocation |
| dnl * GCC_STACK_PROTECT_LIB now adds -lssp to LIBS rather than LDFLAGS |
| dnl |
| dnl About ssp: |
| dnl GCC extension for protecting applications from stack-smashing attacks |
| dnl http://www.research.ibm.com/trl/projects/security/ssp/ |
| dnl |
| dnl Usage: |
| dnl Most people will simply call GCC_STACK_PROTECTOR. |
| dnl If you only use one of C or C++, you can save time by only calling the |
| dnl macro appropriate for that language. In that case you should also call |
| dnl GCC_STACK_PROTECT_LIB first. |
| dnl |
| dnl GCC_STACK_PROTECTOR |
| dnl Tries to turn on stack protection for C and C++ by calling the following |
| dnl three macros with the right languages. |
| dnl |
| dnl GCC_STACK_PROTECT_CC |
| dnl checks -fstack-protector with the C compiler, if it exists then updates |
| dnl CFLAGS and defines ENABLE_SSP_CC |
| dnl |
| dnl GCC_STACK_PROTECT_CXX |
| dnl checks -fstack-protector with the C++ compiler, if it exists then updates |
| dnl CXXFLAGS and defines ENABLE_SSP_CXX |
| dnl |
| dnl GCC_STACK_PROTECT_LIB |
| dnl adds -lssp to LIBS if it is available |
| dnl ssp is usually provided as part of libc, but was previously a separate lib |
| dnl It does not hurt to add -lssp even if libc provides SSP - in that case |
| dnl libssp will simply be ignored. |
| dnl |
| |
| AC_DEFUN([GCC_STACK_PROTECT_LIB],[ |
| AC_CACHE_CHECK([whether libssp exists], ssp_cv_lib, |
| [ssp_old_libs="$LIBS" |
| LIBS="$LIBS -lssp" |
| AC_TRY_LINK(,, ssp_cv_lib=yes, ssp_cv_lib=no) |
| LIBS="$ssp_old_libs" |
| ]) |
| if test $ssp_cv_lib = yes; then |
| LIBS="$LIBS -lssp" |
| fi |
| ]) |
| |
| AC_DEFUN([GCC_STACK_PROTECT_CC],[ |
| AC_LANG_ASSERT(C) |
| if test "X$CC" != "X"; then |
| AC_CACHE_CHECK([whether ${CC} accepts -fstack-protector], |
| ssp_cv_cc, |
| [ssp_old_cflags="$CFLAGS" |
| CFLAGS="$CFLAGS -fstack-protector -Werror" |
| AC_TRY_COMPILE(,, ssp_cv_cc=yes, ssp_cv_cc=no) |
| CFLAGS="$ssp_old_cflags" |
| ]) |
| if test $ssp_cv_cc = yes; then |
| CFLAGS="$CFLAGS -fstack-protector" |
| AC_DEFINE([ENABLE_SSP_CC], 1, [Define if SSP C support is enabled.]) |
| fi |
| fi |
| ]) |
| |
| AC_DEFUN([GCC_STACK_PROTECT_CXX],[ |
| AC_LANG_ASSERT(C++) |
| if test "X$CXX" != "X"; then |
| AC_CACHE_CHECK([whether ${CXX} accepts -fstack-protector], |
| ssp_cv_cxx, |
| [ssp_old_cxxflags="$CXXFLAGS" |
| CXXFLAGS="$CXXFLAGS -fstack-protector -Werror" |
| AC_TRY_COMPILE(,, ssp_cv_cxx=yes, ssp_cv_cxx=no) |
| CXXFLAGS="$ssp_old_cxxflags" |
| ]) |
| if test $ssp_cv_cxx = yes; then |
| CXXFLAGS="$CXXFLAGS -fstack-protector" |
| AC_DEFINE([ENABLE_SSP_CXX], 1, [Define if SSP C++ support is enabled.]) |
| fi |
| fi |
| ]) |
| |
| AC_DEFUN([GCC_STACK_PROTECTOR],[ |
| GCC_STACK_PROTECT_LIB |
| |
| AC_LANG_PUSH([C]) |
| GCC_STACK_PROTECT_CC |
| AC_LANG_POP([C]) |
| |
| AC_LANG_PUSH([C++]) |
| GCC_STACK_PROTECT_CXX |
| AC_LANG_POP([C++]) |
| ]) |
| |
