AES-NI data corruption issues

From: Mathias Krause
Date: Wed Feb 15 2012 - 03:51:23 EST


Hi Linus,

in commit 5b1cbac3.. ("i387: make irq_fpu_usable() tests more robust")
you wrote on a side note:

So this explicitly verifies that we will not touch the TS_USEDFPU bit,
and adds a few related sanity-checks. Because it seems that somehow
AES-NI is corrupting user FP state. The cause is not clear, and this
patch doesn't fix it, but while debugging it I really wanted the code to
be more obviously correct and robust.

Can you please elaborate a little more on the AES-NI issues you're
seeing as I cannot find any information about them on
LKML/bugzilla/linux-crypto? Are they limited to the 3.3-rc kernels or
are they happening on released kernels as well? Are they happening on
32 bit, 64 bit or both?

I'm using aesni-intel.ko and fear my data may vanish, albeit I haven't
observed any data corruption so far.


Regards,
Mathias
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