[PATCH 06/19] KVM: arm64: Get rid of reg_from/to_user()
Marc Zyngier
maz at kernel.org
Wed Jul 6 09:42:51 PDT 2022
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.
Signed-off-by: Marc Zyngier <maz at kernel.org>
---
arch/arm64/kvm/sys_regs.c | 33 +++++++++------------------------
1 file changed, 9 insertions(+), 24 deletions(-)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 1ce439eed3d8..b66be9df7a02 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -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,
@@ -2661,21 +2659,7 @@ 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;
@@ -2684,23 +2668,24 @@ static int get_invariant_sys_reg(u64 id, void __user *uaddr)
if (!r)
return -ENOENT;
- return reg_to_user(uaddr, &r->val, id);
+ if (put_user(r->val, uaddr))
+ return -EFAULT;
+
+ return 0;
}
-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)
--
2.34.1
More information about the linux-arm-kernel
mailing list