x86: use alternative instructions for fnsave/fxsave too
This one ends up using an inline asm format that claims to read memory and then clobber it (rather than just write it directly), which made it easier to use the existing "alternative_input()" infrastructure support. Now the fxsave code matches the fxrstor.
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38afd6adf6
Коммит
2847e3478c
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@ -33,7 +33,7 @@ extern void init_fpu(struct task_struct *);
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"nop ; frstor %1", \
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"fxrstor %1", \
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X86_FEATURE_FXSR, \
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"m" ((tsk)->thread.i387.fsave))
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"m" ((tsk)->thread.i387.fxsave))
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extern void kernel_fpu_begin(void);
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#define kernel_fpu_end() do { stts(); preempt_enable(); } while(0)
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@ -43,13 +43,12 @@ extern void kernel_fpu_begin(void);
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*/
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static inline void __save_init_fpu( struct task_struct *tsk )
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{
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if ( cpu_has_fxsr ) {
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asm volatile( "fxsave %0 ; fnclex"
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: "=m" (tsk->thread.i387.fxsave) );
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} else {
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asm volatile( "fnsave %0 ; fwait"
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: "=m" (tsk->thread.i387.fsave) );
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}
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alternative_input(
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"fnsave %1 ; fwait ;" GENERIC_NOP2,
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"fxsave %1 ; fnclex",
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X86_FEATURE_FXSR,
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"m" (tsk->thread.i387.fxsave)
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:"memory");
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tsk->thread_info->status &= ~TS_USEDFPU;
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}
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