Commit adc997b3 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Borislav Petkov
Browse files

x86/fpu: Use copy_xstate_to_uabi_buf() in xfpregs_get() 



Use the new functionality of copy_xstate_to_uabi_buf() to retrieve the
FX state when XSAVE* is in use. This avoids overwriting the FPU state
buffer with fpstate_sanitize_xstate() which is error prone and duplicated
code.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210623121452.901736860@linutronix.de
parent eb6f5172

arch/x86/kernel/fpu/regset.c

+8 −3
Original line number Original line Diff line number Diff line
@@ -33,13 +33,18 @@ int xfpregs_get(struct task_struct *target, const struct user_regset *regset, 
{

{

	struct fpu *fpu = &target->thread.fpu;

	struct fpu *fpu = &target->thread.fpu;





	if (!boot_cpu_has(X86_FEATURE_FXSR))

	if (!cpu_feature_enabled(X86_FEATURE_FXSR))

		return -ENODEV;

		return -ENODEV;





	fpu__prepare_read(fpu);

	fpu__prepare_read(fpu);

	fpstate_sanitize_xstate(fpu);





	return membuf_write(&to, &fpu->state.fxsave, sizeof(struct fxregs_state));

	if (!use_xsave()) {

		return membuf_write(&to, &fpu->state.fxsave,

				    sizeof(fpu->state.fxsave));

	}



	copy_xstate_to_uabi_buf(to, &fpu->state.xsave, XSTATE_COPY_FX);

	return 0;

}

}





int xfpregs_set(struct task_struct *target, const struct user_regset *regset,

int xfpregs_set(struct task_struct *target, const struct user_regset *regset,