Re: + futex-avoid-kernel-taint-caused-by-get_robust_list.patchadded to -mm tree

From: Richard Weinberger
Date: Fri Feb 15 2013 - 17:44:58 EST


Am Fri, 15 Feb 2013 14:26:52 -0800
schrieb akpm@xxxxxxxxxxxxxxxxxxxx:
> ------------------------------------------------------
> From: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
> Subject: futex: avoid kernel taint caused by get_robust_list
>
> Commit ec0c4274e33c0373e4 ("futex: Mark get_robust_list as
> deprecated") added these two WARN_ONCE calls.
>
> However, WARN_ONCE taints the kernel, and we shouldn't be allowing any
> user who wanders by to do this. For example, the system fuzzer
> "trinity" uses the tainted state as a metric for when to stop,
> assuming that it has caused significant wreckage (and indeed that
> tool is what actually led me to this change).
>
> The ability to deprecate this code has been called into question[1],
> but if that remains to be finalized, then making this change in the
> interim seems to make sense.

Do we really want to remove this system call in 2013?
Note, Documentation/feature-removal-schedule.txt is gone...

CRIU folks, I guess you still need the call?
Or have you found an alternative way to get the robost list?

As stated in [0], I'd simply revert commit ec0c4274 ("futex: Mark
get_robust_list as deprecated")

Thanks,
//richard

[0] http://permalink.gmane.org/gmane.linux.kernel.hardened.devel/506
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