The unlazy_fpu() path calls in to save_fpu() if the task has
TIF_USEDFPU set. save_fpu() being the crap API that it is has the side
effect of clearing the flag itself, which presently doesn't happen
if we're using FPU emulation. Fix this up for now, pending an overhaul
in 2.6.26.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Presently with preempt enabled there's the possibility to be preempted
after the TIF_USEDFPU test and the register save, leading to bogus
state post-__switch_to(). Use an explicit preempt_disable()/enable()
pair around unlazy_fpu()/clear_fpu() to avoid this. Follows the x86
change.
Reported-by: Takuo Koguchi <takuo.koguchi.sw@hitachi.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
