http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28896
--- Comment #25 from Larry Baker <baker at usgs dot gov> 2012-09-10 21:52:34 UTC --- Created attachment 28167 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28167 Patches for Sourcery GCC-4.6-2011.09-23 for ColdFire uClinux These are the patches I am testing. They are for the Mentor Graphics Sourcery CodeBench Lite Edition C/C++ compilers for ColdFire uClinux. The generated code seems to be fine. Unfortunately, my test system is not. And, my assumption that __stack_start was a good choice for detecting stack overflow does not seem to be working out. For my test uClinux executable, stack-overflow.c: #include <stdio.h> void overflow( int i ) { /* Allocate automatic array j[256] so stack limit checking works. */ int j[256]; /* Stack limit checking tests only whether the stack is large enough for */ /* the initial stack allocation: saved registers and automatic variables. */ /* Stack limit checking does not test for stack overflow in the body of a */ /* function. That is what happens when j[] is not present. When j[] is */ /* too large, the program will abnormally terminate on its own (illegal */ /* instruction trap?). j[256] works. */ i++; printf( "i = %i\n", i ); overflow( i ); } int main() { overflow( 0 ); return 0; } the stack is allocated 4K (0x1000). When I hacked the .s file to print out the stack pointer and __stack start, it shows that there is more than 4K between the value in the stack pointer and __stack_start: %sp = 0x405f3ee4 __stack_start = 0x405f08b4 That is not what I was expecting. Here are the instructions for creating the patched GCC I am using: $ wget --no-check-certificate https://sourcery.mentor.com/GNUToolchain/package9493/public/m68k-uclinux/freescale-coldfire-2011.09-23-m68k-uclinux-i686-pc-linux-gnu.tar.bz2 $ tar -xjf freescale-coldfire-2011.09-23-m68k-uclinux-i686-pc-linux-gnu.tar.bz2 $ wget --no-check-certificate https://sourcery.mentor.com/GNUToolchain/package9493/public/m68k-uclinux/freescale-coldfire-2011.09-23-m68k-uclinux.src.tar.bz2 $ tar -xjf freescale-coldfire-2011.09-23-m68k-uclinux.src.tar.bz2 -O freescale-coldfire-2011.09-23-m68k-uclinux/gcc-2011.09-23.tar.bz2 | tar -xjf - $ cd gcc-4.6-2011.09 $ patch -b -p 1 <../gcc-4.6-2011.09-23.patch $ cd .. $ ( cd cross-gcc-4.6-2011.09 ; \ PATH=${PWD}/../freescale-coldfire-2011.09/bin:${PATH/.:/} \ CC_FOR_BUILD=gcc \ CC=gcc \ CXX=g++ \ AR=ar \ RANLIB=ranlib \ AS_FOR_TARGET=m68k-uclinux-as \ LD_FOR_TARGET=m68k-uclinux-ld \ AR_FOR_TARGET=m68k-uclinux-ar \ RANLIB_FOR_TARGET=m68k-uclinux-ranlib \ NM_FOR_TARGET=m68k-uclinux-nm \ OBJDUMP_FOR_TARGET=m68k-uclinux-objdump \ STRIP_FOR_TARGET=m68k-uclinux-strip \ ${PWD}/../gcc-4.6-2011.09/configure \ --disable-decimal-float \ --disable-fixed-point \ --disable-libffi \ --disable-libgomp \ --disable-libmudflap \ --disable-libquadmath \ --disable-libssp \ --disable-libstdcxx-pch \ --disable-nls \ --disable-shared \ --enable-languages=c,c++ \ --enable-lto \ --enable-poison-system-directories \ --enable-threads \ --prefix=${PWD}/../freescale-coldfire-2011.09 \ --program-prefix=m68k-uclinux- \ --target=m68k-uclinux \ --with-arch=cf \ --with-gnu-as \ --with-gnu-ld \ --with-build-time-tools=${PWD}/../freescale-coldfire-2011.09/m68k-uclinux/bin \ --with-host-libstdcxx='-static-libgcc -static-libstdc++ -lm' \ --with-sysroot=${PWD}/../freescale-coldfire-2011.09/m68k-uclinux/libc ) $ ( cd cross-gcc-4.6-2011.09 ; \ PATH=${PWD}/../freescale-coldfire-2011.09/bin:${PATH/.:/} \ make -j4 ) $ ( cd cross-gcc-4.6-2011.09 ; \ PATH=${PWD}/../freescale-coldfire-2011.09/bin:${PATH/.:/} \ make install ) $ toolchains/freescale-coldfire-2011.09-patched/bin/m68k-uclinux-gcc -mcpu=5208 -fomit-frame-pointer -fno-common -fno-builtin -fno-dwarf2-cfi-asm -msep-data -fstack-limit-symbol=__stack_start -o check-stack-overflow stack-overflow.c Larry Baker
