Commit be31dfdf authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Borislav Petkov
Browse files

x86/fpu: Use fpstate::size 



Make use of fpstate::size in various places which require the buffer size
information for sanity checks or memcpy() sizing.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211013145322.973518954@linutronix.de
parent 248452ce

arch/x86/kernel/fpu/core.c

+6 −7
Original line number Diff line number Diff line
@@ -166,14 +166,13 @@ void fpu_swap_kvm_fpu(struct fpu *save, struct fpu *rstor, u64 restore_mask) 
	fpregs_lock();



	if (save) {

		if (test_thread_flag(TIF_NEED_FPU_LOAD)) {

			memcpy(&save->fpstate->regs,

			       &current->thread.fpu.fpstate->regs,

			       fpu_kernel_xstate_size);

		} else {

		struct fpstate *fpcur = current->thread.fpu.fpstate;



		if (test_thread_flag(TIF_NEED_FPU_LOAD))

			memcpy(&save->fpstate->regs, &fpcur->regs, fpcur->size);

		else

			save_fpregs_to_fpstate(save);

	}

	}



	if (rstor) {

		restore_mask &= xfeatures_mask_fpstate();
@@ -398,7 +397,7 @@ int fpu_clone(struct task_struct *dst) 
	fpregs_lock();

	if (test_thread_flag(TIF_NEED_FPU_LOAD)) {

		memcpy(&dst_fpu->fpstate->regs, &src_fpu->fpstate->regs,

		       fpu_kernel_xstate_size);

		       dst_fpu->fpstate->size);

	} else {

		save_fpregs_to_fpstate(dst_fpu);

	}

arch/x86/kernel/fpu/signal.c

+3 −4
Original line number Diff line number Diff line
@@ -313,15 +313,13 @@ static bool restore_fpregs_from_user(void __user *buf, u64 xrestore, 
static bool __fpu_restore_sig(void __user *buf, void __user *buf_fx,

			      bool ia32_fxstate)

{

	int state_size = fpu_kernel_xstate_size;

	struct task_struct *tsk = current;

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

	struct user_i387_ia32_struct env;

	bool success, fx_only = false;

	union fpregs_state *fpregs;

	unsigned int state_size;

	u64 user_xfeatures = 0;

	bool fx_only = false;

	bool success;





	if (use_xsave()) {

		struct _fpx_sw_bytes fx_sw_user;
@@ -334,6 +332,7 @@ static bool __fpu_restore_sig(void __user *buf, void __user *buf_fx, 
		user_xfeatures = fx_sw_user.xfeatures;

	} else {

		user_xfeatures = XFEATURE_MASK_FPSSE;

		state_size = fpu->fpstate->size;

	}



	if (likely(!ia32_fxstate)) {