From 51e74f538c2262723df1e47ae79b45f3ecbb2e9b Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Wed, 18 Apr 2007 20:39:57 +0000 Subject: Yes, I suck. This commit contains two totally unrelated changes and I really should commit them seperately, but I am ignoring my own rules, and do it in a single commit. I suck. I really do. I am sorry. Please don't try this at home. And please don't tell your children! * Show properly that avahi-autoipd is not built if libdaemon is missing (Closes #133) * Enable stack-smashing protection if available and wokring. Patch from tedp. (Closes #105) git-svn-id: file:///home/lennart/svn/public/avahi/trunk@1440 941a03a8-eaeb-0310-b9a0-b1bbd8fe43fe --- common/gcc_stack_protect.m4 | 42 ++++++++++++++++++++++++++++++++---------- 1 file changed, 32 insertions(+), 10 deletions(-) (limited to 'common') diff --git a/common/gcc_stack_protect.m4 b/common/gcc_stack_protect.m4 index 616101e..13c5e0a 100644 --- a/common/gcc_stack_protect.m4 +++ b/common/gcc_stack_protect.m4 @@ -6,19 +6,23 @@ 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 +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 Call GCC_STACK_PROTECT_LIB to determine if the library implementing SSP is -dnl available, then the appropriate C or C++ language's test. If you are using -dnl both C and C++ you will need to use AC_LANG_PUSH and AC_LANG_POP to ensure -dnl the right language is being used for each test. +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_PROTECT_LIB -dnl adds libssp to the LDFLAGS if it is available +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 @@ -28,16 +32,22 @@ 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_ldflags="$LDFLAGS" - LDFLAGS="$LDFLAGS -lssp" + [ssp_old_libs="$LIBS" + LIBS="$LIBS -lssp" AC_TRY_LINK(,, ssp_cv_lib=yes, ssp_cv_lib=no) - LDFLAGS="$ssp_old_ldflags" + LIBS="$ssp_old_libs" ]) if test $ssp_cv_lib = yes; then - LDFLAGS="$LDFLAGS -lssp" + LIBS="$LIBS -lssp" fi ]) @@ -75,3 +85,15 @@ AC_DEFUN([GCC_STACK_PROTECT_CXX],[ 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++]) +]) + -- cgit