Messages in this thread | | | Date | Fri, 02 Mar 2007 17:19:44 -0500 | From | Chuck Ebbert <> | Subject | Re: + fully-honor-vdso_enabled.patch added to -mm tree |
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John Reiser wrote: > The value of ->sysenter_return is interpreted in user space by the > sysexit instruction; nobody else cares what the value is. The kernel > is not required to provide a good value when vdso_enabled is zero, > because the kernel has not told the process that sysenter is valid > (by setting AT_SYSINFO.)
Doesn't matter because a malicious user can still execute sysenter. We do have to deal with that somehow, so we have to put something safe in there.
> Correct. Changing vdso_enabled from 0 to non-zero must be prepared > to lose this race if it is not prevented. Ordinarily it won't matter > because the administrator will perform such changes at a "quiet" time. >
We have to deal with all the possibilities here, too. - 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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