On 07/20/2015 10:07 PM, josh@xxxxxxxxxxxxxxxx wrote: > On Mon, Jul 20, 2015 at 10:41:09AM -0700, Andy Lutomirski wrote: >> On Mon, Jul 20, 2015 at 8:32 AM, Florian Weimer <fweimer@xxxxxxxxxx> wrote: >>> On 07/20/2015 05:31 PM, Andy Lutomirski wrote: >>>> On Jul 20, 2015 1:35 AM, "Florian Weimer" <fweimer@xxxxxxxxxx> wrote: >>>>> >>>>> On 07/18/2015 01:33 AM, Andy Lutomirski wrote: >>>>> >>>>>> I think the API should be "set gsbase to x + y*(cpu number)". On >>>>>> x86_64, userspace just allocates a big swath of virtual space and >>>>>> populates it as needed. >>>>> >>>>> This will break WINE and similar applications which use %gs today. >>>> >>>> Presumably WINE could just opt not to use this facility, just like >>>> WINE will have to opt out of whatever the enterprise people who want >>>> WRGSBASE were thinking of doing with it. >>> >>> How is this possible if it's process-global attribute and glibc or some >>> library in the process starts using it? >>> >> >> glibc will have to expose a way to turn it off, I guess. (ELF flag?) > > Or a way to turn it on. How is this supposed to work? Who should turn it on? It totally breaks encapsulation. We don't need any additional problems like that. -- Florian Weimer / Red Hat Product Security -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
