Commit 5a420ed9 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: arm64: Get rid of reg_from/to_user() 



These helpers are only used by the invariant stuff now, and while
they pretend to support non-64bit registers, this only serves as
a way to scare the casual reviewer...

Replace these helpers with our good friends get/put_user(), and
don't look back.

Reviewed-by: default avatarReiji Watanabe <reijiw@google.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent 978ceeb3

arch/arm64/kvm/sys_regs.c

+6 −24
Original line number Diff line number Diff line
@@ -44,8 +44,6 @@ 
 * 64bit interface.

 */



static int reg_from_user(u64 *val, const void __user *uaddr, u64 id);

static int reg_to_user(void __user *uaddr, const u64 *val, u64 id);

static u64 sys_reg_to_index(const struct sys_reg_desc *reg);



static bool read_from_write_only(struct kvm_vcpu *vcpu,
@@ -2657,21 +2655,7 @@ static struct sys_reg_desc invariant_sys_regs[] = { 
	{ SYS_DESC(SYS_CTR_EL0), NULL, get_ctr_el0 },

};



static int reg_from_user(u64 *val, const void __user *uaddr, u64 id)

{

	if (copy_from_user(val, uaddr, KVM_REG_SIZE(id)) != 0)

		return -EFAULT;

	return 0;

}



static int reg_to_user(void __user *uaddr, const u64 *val, u64 id)

{

	if (copy_to_user(uaddr, val, KVM_REG_SIZE(id)) != 0)

		return -EFAULT;

	return 0;

}



static int get_invariant_sys_reg(u64 id, void __user *uaddr)

static int get_invariant_sys_reg(u64 id, u64 __user *uaddr)

{

	const struct sys_reg_desc *r;
@@ -2680,23 +2664,21 @@ static int get_invariant_sys_reg(u64 id, void __user *uaddr) 
	if (!r)

		return -ENOENT;



	return reg_to_user(uaddr, &r->val, id);

	return put_user(r->val, uaddr);

}



static int set_invariant_sys_reg(u64 id, void __user *uaddr)

static int set_invariant_sys_reg(u64 id, u64 __user *uaddr)

{

	const struct sys_reg_desc *r;

	int err;

	u64 val = 0; /* Make sure high bits are 0 for 32-bit regs */

	u64 val;



	r = get_reg_by_id(id, invariant_sys_regs,

			  ARRAY_SIZE(invariant_sys_regs));

	if (!r)

		return -ENOENT;



	err = reg_from_user(&val, uaddr, id);

	if (err)

		return err;

	if (get_user(val, uaddr))

		return -EFAULT;



	/* This is what we mean by invariant: you can't change it. */

	if (r->val != val)