On Tue, Sep 1, 2015 at 8:51 PM, Andy Lutomirski <l...@amacapital.net> wrote: > Hi all- > > Linux has a handful of weird features that are only supported for > backwards compatibility. The big one is the x86_64 vsyscall page, but > uselib probably belongs on the list, too, and we might end up with > more at some point. > > I'd like to add a way that new programs can turn these features off. > In particular, I want the vsyscall page to be completely gone from the > perspective of any new enough program. This is straightforward if we > add a system call to ask for the vsyscall page to be disabled, but I'm > wondering if we can come up with a non-syscall way to do it. > > I think that the ideal behavior would be that anything linked against > a sufficiently new libc would be detected, but I don't see a good way > to do that using existing toolchain features. > > Ideas? We could add a new phdr for this, but then we'd need to play > linker script games, and I'm not sure that could be done in a clean, > extensible way.
The vsyscall page is mapped in the fixmap region, which is shared between all processes. You can't turn it off for an individual process. -- Brian Gerst -- 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/
