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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: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Marc Zyngier 2022-07-04 17:55:43 +01:00
parent 978ceeb3e4
commit 5a420ed964
1 changed files with 6 additions and 24 deletions
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30
arch/arm64/kvm/sys_regs.c
View File

@ -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)