eglibc newer than 2.12.1 in natty results in alignment errors, SIGLILL and segfaults on tegra2 systems
doing an upgrade from a maverick to a natty rootfs on tegra2 hardware results in a mostly nonworking system, apps segfailt or die with SIGILL, dmesg is full of alignment error messages.
apparently tegra 2 processors have a bug in the register read path of bit 20 of the CP15 c13, 3 register (used for software thread local storage)
there is a tegra errata (657451) for kernel as well as for the android bionic lib that seems to work around the issue
in maverick libc did not have this issue, it only regressed in natty due to either a change in libc or in the toolchain.
pinning libc to 2.12.1 and doing a dist-upgrade makes everything work fine.