[PATCH] FreeBSD-SA-06:14.fpu
Matthew Dillon
dillon at apollo.backplane.com
Sun May 21 16:51:55 PDT 2006
:>
:> By the way, following command could be used to check how kernel has
:> been compiled, regarding the CPU_FXSAVE_LEAK option:
:>
:> objdump -x /boot/kernel/kernel | grep fpu_clean_state
:
:The patch looks fine to me, but can it be CPU_FXSAVE_NOLEAK ?
:so only people know the problem will turn it on.
:
:David Xu
I don't think it really needs to be optioned. Since the FPU state
is demand-loaded from a trap/exception anyway, a huge amount of code
is run in the same path that fpu_clean_state is called from.
fpu_clean_state itself only eats a few nanoseconds (like maybe ~1/10
of the time that fninit takes).
-Matt
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