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Commit fcb2ac5b authored by Jiri Slaby's avatar Jiri Slaby Committed by Ingo Molnar
Browse files

x86_32: introduce restore_fpu_checking() 



Impact: cleanup, prepare FPU code unificaton

Like on x86_64, return an error from restore_fpu and kill the task
if it fails.

Also rename restore_fpu to restore_fpu_checking which allows ifdefs
to be removed in math_state_restore().

Signed-off-by: default avatarJiri Slaby <jirislaby@gmail.com>
LKML-Reference: <1239190320-23952-1-git-send-email-jirislaby@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 577c9c45

arch/x86/include/asm/i387.h

+4 −5
Original line number Diff line number Diff line
@@ -185,12 +185,10 @@ static inline void tolerant_fwait(void) 
	asm volatile("fnclex ; fwait");

}



static inline void restore_fpu(struct task_struct *tsk)

static inline int restore_fpu_checking(struct task_struct *tsk)

{

	if (task_thread_info(tsk)->status & TS_XSAVE) {

		xrstor_checking(&tsk->thread.xstate->xsave);

		return;

	}

	if (task_thread_info(tsk)->status & TS_XSAVE)

		return xrstor_checking(&tsk->thread.xstate->xsave);

	/*

	 * The "nop" is needed to make the instructions the same

	 * length.
@@ -200,6 +198,7 @@ static inline void restore_fpu(struct task_struct *tsk) 
		"fxrstor %1",

		X86_FEATURE_FXSR,

		"m" (tsk->thread.xstate->fxsave));

	return 0;

}



/* We need a safe address that is cheap to find and that is already

arch/x86/kernel/traps.c

+1 −4
Original line number Diff line number Diff line
@@ -839,9 +839,6 @@ asmlinkage void math_state_restore(void) 
	}



	clts();				/* Allow maths ops (or we recurse) */

#ifdef CONFIG_X86_32

	restore_fpu(tsk);

#else

	/*

	 * Paranoid restore. send a SIGSEGV if we fail to restore the state.

	 */
@@ -850,7 +847,7 @@ asmlinkage void math_state_restore(void) 
		force_sig(SIGSEGV, tsk);

		return;

	}

#endif



	thread->status |= TS_USEDFPU;	/* So we fnsave on switch_to() */

	tsk->fpu_counter++;

}