On 12/12/2014 12:48 PM, Andy Lutomirski wrote: > On Fri, Dec 12, 2014 at 12:27 PM, Dave Hansen <d...@sr71.net> wrote: >> You want the same size structures with the same format for 32-bit and >> 64-bit modes? > > Yes. Especially because programs can switch between 32-bit and 64-bit > mode entirely in userspace. I don't know whether any do in practice, > but programs *can*.
So, you want a 2GB of the 32-bit address space dedicated to a bounds directory, and half of the space for the bounds tables to be simply zero-filled unused address bits? That seems, um, a bit unreasonable. > Or better yet: Intel could have skipped supporting it at all in 32-bit > mode. So, we should not have this security feature for 32-bit apps... because it costs us 50 lines of code in the kernel to support? Did you look at the diffstat? > Isn't mpx somewhat of an address space hog anyway? Yes, it will be troublesome for 32-bit apps that are already bumping up against the virtual address space size to support it. But, really, how many of those *are* there these days? -- 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/
