On 5/29/10, Bruce Dubbs <bruce.du...@gmail.com> wrote: > $ nm -a /mnt/lfs/tools/lib/libssp.so.0.0.0|grep stack > 0000000000001000 T __stack_chk_fail > 0000000000001040 t __stack_chk_fail_local > 0000000000201d60 B __stack_chk_guard >
nm -a /usr/lib/libssp.so.0.0.0 | grep stack shows similar output on backups with linux-2.6.18.8 similar as 2.6.33, e.g.,: 00000c10 T __stack_chk_fail 00000c50 t __stack_chk_fail_local 000025a8 B __stack_chk_guard http://cateee.net/lkddb/web-lkddb/CC_STACKPROTECTOR.html arch/x86/Kconfig The configuration item CONFIG_CC_STACKPROTECTOR: * prompt: Enable -fstack-protector buffer overflow detection (EXPERIMENTAL) * type: tristate * depends on: CONFIG_X86_64 && CONFIG_EXPERIMENTAL && CONFIG_BROKEN * defined in arch/x86/Kconfig * found in Linux Kernels: from 2.6.19 release still available on 2.6.34 release Help text This option turns on the -fstack-protector GCC feature. This feature puts, at the beginning of critical functions, a canary value on the stack just before the return address, and validates the value just before actually returning. Stack based buffer overflows (that need to overwrite this return address) now also overwrite the canary, which gets detected and the attack is then neutralized via a kernel panic. This feature requires gcc version 4.2 or above, or a distribution gcc with the feature backported. Older versions are automatically detected and for those versions, this configuration option is ignored. hrmm # CONFIG_CC_STACKPROTECTOR is not set is not seen in any /boot/config-x.y.z (kernel config) files I have saved until gcc became >= 4.2 "Older versions are automatically detected and for those versions, this configuration option is ignored." [ ... thinking ...] thus would not be a possible kernel config option. I guess this is something different from libssp Can you not go across the gcc 4.2 boundary to or from a 2.6.18 kernel? What if you built a Linux-2.6.22.5 kernel on the host and try that? -- http://linuxfromscratch.org/mailman/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/lfs/faq.html Unsubscribe: See the above information page
