Commit 003e2e8b authored by Ingo Molnar's avatar Ingo Molnar
Browse files

x86/fpu: Standardize the parameter type of copy_kernel_to_fpregs() 



Bring the __copy_fpstate_to_fpregs() and copy_fpstate_to_fpregs() functions
in line with the parameter passing convention of other kernel-to-FPU-registers
copying functions: pass around an in-memory FPU register state pointer,
instead of struct fpu *.

NOTE: This patch also changes the assembly constraint of the FXSAVE-leak
      workaround from 'fpu->fpregs_active' to 'fpstate' - but that is fine,
      as we only need a valid memory address there for the FILDL instruction.

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 9ccc27a5

arch/x86/include/asm/fpu/internal.h

+8 −8
Original line number Diff line number Diff line
@@ -446,19 +446,19 @@ static inline int copy_fpregs_to_fpstate(struct fpu *fpu) 
	return 0;

}



static inline void __copy_kernel_to_fpregs(struct fpu *fpu)

static inline void __copy_kernel_to_fpregs(union fpregs_state *fpstate)

{

	if (use_xsave()) {

		copy_kernel_to_xregs(&fpu->state.xsave, -1);

		copy_kernel_to_xregs(&fpstate->xsave, -1);

	} else {

		if (use_fxsr())

			copy_kernel_to_fxregs(&fpu->state.fxsave);

			copy_kernel_to_fxregs(&fpstate->fxsave);

		else

			copy_kernel_to_fregs(&fpu->state.fsave);

			copy_kernel_to_fregs(&fpstate->fsave);

	}

}



static inline void copy_kernel_to_fpregs(struct fpu *fpu)

static inline void copy_kernel_to_fpregs(union fpregs_state *fpstate)

{

	/*

	 * AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception is
@@ -470,10 +470,10 @@ static inline void copy_kernel_to_fpregs(struct fpu *fpu) 
			"fnclex\n\t"

			"emms\n\t"

			"fildl %P[addr]"	/* set F?P to defined value */

			: : [addr] "m" (fpu->fpregs_active));

			: : [addr] "m" (fpstate));

	}



	__copy_kernel_to_fpregs(fpu);

	__copy_kernel_to_fpregs(fpstate);

}



extern int copy_fpstate_to_sigframe(void __user *buf, void __user *fp, int size);
@@ -642,7 +642,7 @@ switch_fpu_prepare(struct fpu *old_fpu, struct fpu *new_fpu, int cpu) 
static inline void switch_fpu_finish(struct fpu *new_fpu, fpu_switch_t fpu_switch)

{

	if (fpu_switch.preload)

		copy_kernel_to_fpregs(new_fpu);

		copy_kernel_to_fpregs(&new_fpu->state);

}



/*

arch/x86/kernel/fpu/core.c

+2 −2
Original line number Diff line number Diff line
@@ -127,7 +127,7 @@ void __kernel_fpu_end(void) 
	struct fpu *fpu = &current->thread.fpu;



	if (fpu->fpregs_active)

		copy_kernel_to_fpregs(fpu);

		copy_kernel_to_fpregs(&fpu->state);

	else

		__fpregs_deactivate_hw();
@@ -368,7 +368,7 @@ void fpu__restore(struct fpu *fpu) 
	/* Avoid __kernel_fpu_begin() right after fpregs_activate() */

	kernel_fpu_disable();

	fpregs_activate(fpu);

	copy_kernel_to_fpregs(fpu);

	copy_kernel_to_fpregs(&fpu->state);

	fpu->counter++;

	kernel_fpu_enable();

}

arch/x86/kvm/x86.c

+1 −1
Original line number Diff line number Diff line
@@ -7030,7 +7030,7 @@ void kvm_load_guest_fpu(struct kvm_vcpu *vcpu) 
	kvm_put_guest_xcr0(vcpu);

	vcpu->guest_fpu_loaded = 1;

	__kernel_fpu_begin();

	__copy_kernel_to_fpregs(&vcpu->arch.guest_fpu);

	__copy_kernel_to_fpregs(&vcpu->arch.guest_fpu.state);

	trace_kvm_fpu(1);

}

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