Messages in this thread | | | From | Andrew Lutomirski <> | Date | Fri, 14 Oct 2011 13:31:14 -0700 | Subject | Re: [RFC] fixing the UML failure root cause |
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On Fri, Oct 14, 2011 at 1:23 PM, richard -rw- weinberger <richard.weinberger@gmail.com> wrote: > On Fri, Oct 14, 2011 at 10:17 PM, Andrew Lutomirski <luto@mit.edu> wrote: >> On Fri, Oct 14, 2011 at 12:53 PM, richard -rw- weinberger >> <richard.weinberger@gmail.com> wrote: >>> On Tue, Oct 11, 2011 at 7:24 PM, Andrew Lutomirski <luto@mit.edu> wrote: >>>> What do you think of this approach? If it seems good, I'll finish the >>>> patch and submit it. >>>> >>>> With this patch applied, UML appears to work, but it fills the log with >>>> exploit attempt warnings. Any ideas on what to do about that? >>>> >>> >>> I can confirm that this patch works. >>> And I really like vsyscall=emulate because with that UML can trap vsyscalls. :-) >> >> Are you sure you don't mean vsyscall=native? I suspect that UML can't >> actually trap vsyscalls in emulate mode right now, although that ought >> to be fixable. >> > > Doesn't vsyscall_emu_64.S transform any vsyscall into a real syscall? > So UML can trap it.
Only if that code actually executes. In vsyscall=emulate mode, the page is not executable and a trap is taken instead. It's not entirely clear what the right thing to do is wrt ptrace users.
--Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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