On Wed, Nov 6, 2013 at 2:30 PM, Matt Sealey <n...@bakuhatsu.net> wrote: > On Tue, Nov 5, 2013 at 6:14 PM, Kees Cook <keesc...@chromium.org> wrote: >> >> Alternatively, CONFIG_SECCOMP_FILTER could depend on >> !CONFIG_OABI_COMPAT. That seems like the least work, given the desire >> to kill OABI in the real world. (Though I would note that at least >> Ubuntu's ARM kernels build with CONFIG_OABI_COMPAT; Chrome OS does >> not.) > > I think CONFIG_OABI_COMPAT probably leaked in from the original > configurations of the kernel taken from Debian. > > There were several big decisions they made (build for ARMv5 soft > float, then switch to ARMv7 softfp, then switch to ARMv7 hardfp, then > switch to using THUMB2 kernels) which would have just broken OABI > binaries at every step of the way since they had some subtle > implications in kernel configuration (note: Ubuntu have never, ever > enabled FPA emulation in the kernel, and all Debian's OABI userspace > is built for FPA, for example. A good chunk of the original Debian arm > port probably would just pitch a SIGILL if you ran it under an Ubuntu > kernel). > > I would ignore anyone who enables it in a distribution, since they > probably weren't intending to enable it in the first place, and never > noticed the.. what.. 3-4KiB it adds to the kernel? >
Forget the size -- it adds a fair amount of complexity and a D-cache miss on every syscall. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
